xref: /linux/net/core/dev.c (revision 56d8b784c56588cd40f98e4b1d4f6e29e3cb02b8)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      NET3    Protocol independent device support routines.
4  *
5  *	Derived from the non IP parts of dev.c 1.0.19
6  *              Authors:	Ross Biro
7  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
8  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
9  *
10  *	Additional Authors:
11  *		Florian la Roche <rzsfl@rz.uni-sb.de>
12  *		Alan Cox <gw4pts@gw4pts.ampr.org>
13  *		David Hinds <dahinds@users.sourceforge.net>
14  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
15  *		Adam Sulmicki <adam@cfar.umd.edu>
16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
17  *
18  *	Changes:
19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
20  *                                      to 2 if register_netdev gets called
21  *                                      before net_dev_init & also removed a
22  *                                      few lines of code in the process.
23  *		Alan Cox	:	device private ioctl copies fields back.
24  *		Alan Cox	:	Transmit queue code does relevant
25  *					stunts to keep the queue safe.
26  *		Alan Cox	:	Fixed double lock.
27  *		Alan Cox	:	Fixed promisc NULL pointer trap
28  *		????????	:	Support the full private ioctl range
29  *		Alan Cox	:	Moved ioctl permission check into
30  *					drivers
31  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
32  *		Alan Cox	:	100 backlog just doesn't cut it when
33  *					you start doing multicast video 8)
34  *		Alan Cox	:	Rewrote net_bh and list manager.
35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
36  *		Alan Cox	:	Took out transmit every packet pass
37  *					Saved a few bytes in the ioctl handler
38  *		Alan Cox	:	Network driver sets packet type before
39  *					calling netif_rx. Saves a function
40  *					call a packet.
41  *		Alan Cox	:	Hashed net_bh()
42  *		Richard Kooijman:	Timestamp fixes.
43  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
44  *		Alan Cox	:	Device lock protection.
45  *              Alan Cox        :       Fixed nasty side effect of device close
46  *					changes.
47  *		Rudi Cilibrasi	:	Pass the right thing to
48  *					set_mac_address()
49  *		Dave Miller	:	32bit quantity for the device lock to
50  *					make it work out on a Sparc.
51  *		Bjorn Ekwall	:	Added KERNELD hack.
52  *		Alan Cox	:	Cleaned up the backlog initialise.
53  *		Craig Metz	:	SIOCGIFCONF fix if space for under
54  *					1 device.
55  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
56  *					is no device open function.
57  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
58  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
59  *		Cyrus Durgin	:	Cleaned for KMOD
60  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
61  *					A network device unload needs to purge
62  *					the backlog queue.
63  *	Paul Rusty Russell	:	SIOCSIFNAME
64  *              Pekka Riikonen  :	Netdev boot-time settings code
65  *              Andrew Morton   :       Make unregister_netdevice wait
66  *                                      indefinitely on dev->refcnt
67  *              J Hadi Salim    :       - Backlog queue sampling
68  *				        - netif_rx() feedback
69  */
70 
71 #include <linux/uaccess.h>
72 #include <linux/bitmap.h>
73 #include <linux/capability.h>
74 #include <linux/cpu.h>
75 #include <linux/types.h>
76 #include <linux/kernel.h>
77 #include <linux/hash.h>
78 #include <linux/slab.h>
79 #include <linux/sched.h>
80 #include <linux/sched/isolation.h>
81 #include <linux/sched/mm.h>
82 #include <linux/smpboot.h>
83 #include <linux/mutex.h>
84 #include <linux/rwsem.h>
85 #include <linux/string.h>
86 #include <linux/mm.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/errno.h>
90 #include <linux/interrupt.h>
91 #include <linux/if_ether.h>
92 #include <linux/netdevice.h>
93 #include <linux/etherdevice.h>
94 #include <linux/ethtool.h>
95 #include <linux/skbuff.h>
96 #include <linux/kthread.h>
97 #include <linux/bpf.h>
98 #include <linux/bpf_trace.h>
99 #include <net/net_namespace.h>
100 #include <net/sock.h>
101 #include <net/busy_poll.h>
102 #include <linux/rtnetlink.h>
103 #include <linux/stat.h>
104 #include <net/dsa.h>
105 #include <net/dst.h>
106 #include <net/dst_metadata.h>
107 #include <net/gro.h>
108 #include <net/pkt_sched.h>
109 #include <net/pkt_cls.h>
110 #include <net/checksum.h>
111 #include <net/xfrm.h>
112 #include <net/tcx.h>
113 #include <linux/highmem.h>
114 #include <linux/init.h>
115 #include <linux/module.h>
116 #include <linux/netpoll.h>
117 #include <linux/rcupdate.h>
118 #include <linux/delay.h>
119 #include <net/iw_handler.h>
120 #include <asm/current.h>
121 #include <linux/audit.h>
122 #include <linux/dmaengine.h>
123 #include <linux/err.h>
124 #include <linux/ctype.h>
125 #include <linux/if_arp.h>
126 #include <linux/if_vlan.h>
127 #include <linux/ip.h>
128 #include <net/ip.h>
129 #include <net/mpls.h>
130 #include <linux/ipv6.h>
131 #include <linux/in.h>
132 #include <linux/jhash.h>
133 #include <linux/random.h>
134 #include <trace/events/napi.h>
135 #include <trace/events/net.h>
136 #include <trace/events/skb.h>
137 #include <trace/events/qdisc.h>
138 #include <trace/events/xdp.h>
139 #include <linux/inetdevice.h>
140 #include <linux/cpu_rmap.h>
141 #include <linux/static_key.h>
142 #include <linux/hashtable.h>
143 #include <linux/vmalloc.h>
144 #include <linux/if_macvlan.h>
145 #include <linux/errqueue.h>
146 #include <linux/hrtimer.h>
147 #include <linux/netfilter_netdev.h>
148 #include <linux/crash_dump.h>
149 #include <linux/sctp.h>
150 #include <net/udp_tunnel.h>
151 #include <linux/net_namespace.h>
152 #include <linux/indirect_call_wrapper.h>
153 #include <net/devlink.h>
154 #include <linux/pm_runtime.h>
155 #include <linux/prandom.h>
156 #include <linux/once_lite.h>
157 #include <net/netdev_rx_queue.h>
158 #include <net/page_pool/types.h>
159 #include <net/page_pool/helpers.h>
160 #include <net/rps.h>
161 
162 #include "dev.h"
163 #include "net-sysfs.h"
164 
165 static DEFINE_SPINLOCK(ptype_lock);
166 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
167 
168 static int netif_rx_internal(struct sk_buff *skb);
169 static int call_netdevice_notifiers_extack(unsigned long val,
170 					   struct net_device *dev,
171 					   struct netlink_ext_ack *extack);
172 
173 static DEFINE_MUTEX(ifalias_mutex);
174 
175 /* protects napi_hash addition/deletion and napi_gen_id */
176 static DEFINE_SPINLOCK(napi_hash_lock);
177 
178 static unsigned int napi_gen_id = NR_CPUS;
179 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
180 
181 static DECLARE_RWSEM(devnet_rename_sem);
182 
183 static inline void dev_base_seq_inc(struct net *net)
184 {
185 	unsigned int val = net->dev_base_seq + 1;
186 
187 	WRITE_ONCE(net->dev_base_seq, val ?: 1);
188 }
189 
190 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
191 {
192 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
193 
194 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
195 }
196 
197 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
198 {
199 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
200 }
201 
202 #ifndef CONFIG_PREEMPT_RT
203 
204 static DEFINE_STATIC_KEY_FALSE(use_backlog_threads_key);
205 
206 static int __init setup_backlog_napi_threads(char *arg)
207 {
208 	static_branch_enable(&use_backlog_threads_key);
209 	return 0;
210 }
211 early_param("thread_backlog_napi", setup_backlog_napi_threads);
212 
213 static bool use_backlog_threads(void)
214 {
215 	return static_branch_unlikely(&use_backlog_threads_key);
216 }
217 
218 #else
219 
220 static bool use_backlog_threads(void)
221 {
222 	return true;
223 }
224 
225 #endif
226 
227 static inline void backlog_lock_irq_save(struct softnet_data *sd,
228 					 unsigned long *flags)
229 {
230 	if (IS_ENABLED(CONFIG_RPS) || use_backlog_threads())
231 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
232 	else
233 		local_irq_save(*flags);
234 }
235 
236 static inline void backlog_lock_irq_disable(struct softnet_data *sd)
237 {
238 	if (IS_ENABLED(CONFIG_RPS) || use_backlog_threads())
239 		spin_lock_irq(&sd->input_pkt_queue.lock);
240 	else
241 		local_irq_disable();
242 }
243 
244 static inline void backlog_unlock_irq_restore(struct softnet_data *sd,
245 					      unsigned long *flags)
246 {
247 	if (IS_ENABLED(CONFIG_RPS) || use_backlog_threads())
248 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
249 	else
250 		local_irq_restore(*flags);
251 }
252 
253 static inline void backlog_unlock_irq_enable(struct softnet_data *sd)
254 {
255 	if (IS_ENABLED(CONFIG_RPS) || use_backlog_threads())
256 		spin_unlock_irq(&sd->input_pkt_queue.lock);
257 	else
258 		local_irq_enable();
259 }
260 
261 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
262 						       const char *name)
263 {
264 	struct netdev_name_node *name_node;
265 
266 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
267 	if (!name_node)
268 		return NULL;
269 	INIT_HLIST_NODE(&name_node->hlist);
270 	name_node->dev = dev;
271 	name_node->name = name;
272 	return name_node;
273 }
274 
275 static struct netdev_name_node *
276 netdev_name_node_head_alloc(struct net_device *dev)
277 {
278 	struct netdev_name_node *name_node;
279 
280 	name_node = netdev_name_node_alloc(dev, dev->name);
281 	if (!name_node)
282 		return NULL;
283 	INIT_LIST_HEAD(&name_node->list);
284 	return name_node;
285 }
286 
287 static void netdev_name_node_free(struct netdev_name_node *name_node)
288 {
289 	kfree(name_node);
290 }
291 
292 static void netdev_name_node_add(struct net *net,
293 				 struct netdev_name_node *name_node)
294 {
295 	hlist_add_head_rcu(&name_node->hlist,
296 			   dev_name_hash(net, name_node->name));
297 }
298 
299 static void netdev_name_node_del(struct netdev_name_node *name_node)
300 {
301 	hlist_del_rcu(&name_node->hlist);
302 }
303 
304 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
305 							const char *name)
306 {
307 	struct hlist_head *head = dev_name_hash(net, name);
308 	struct netdev_name_node *name_node;
309 
310 	hlist_for_each_entry(name_node, head, hlist)
311 		if (!strcmp(name_node->name, name))
312 			return name_node;
313 	return NULL;
314 }
315 
316 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
317 							    const char *name)
318 {
319 	struct hlist_head *head = dev_name_hash(net, name);
320 	struct netdev_name_node *name_node;
321 
322 	hlist_for_each_entry_rcu(name_node, head, hlist)
323 		if (!strcmp(name_node->name, name))
324 			return name_node;
325 	return NULL;
326 }
327 
328 bool netdev_name_in_use(struct net *net, const char *name)
329 {
330 	return netdev_name_node_lookup(net, name);
331 }
332 EXPORT_SYMBOL(netdev_name_in_use);
333 
334 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
335 {
336 	struct netdev_name_node *name_node;
337 	struct net *net = dev_net(dev);
338 
339 	name_node = netdev_name_node_lookup(net, name);
340 	if (name_node)
341 		return -EEXIST;
342 	name_node = netdev_name_node_alloc(dev, name);
343 	if (!name_node)
344 		return -ENOMEM;
345 	netdev_name_node_add(net, name_node);
346 	/* The node that holds dev->name acts as a head of per-device list. */
347 	list_add_tail_rcu(&name_node->list, &dev->name_node->list);
348 
349 	return 0;
350 }
351 
352 static void netdev_name_node_alt_free(struct rcu_head *head)
353 {
354 	struct netdev_name_node *name_node =
355 		container_of(head, struct netdev_name_node, rcu);
356 
357 	kfree(name_node->name);
358 	netdev_name_node_free(name_node);
359 }
360 
361 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
362 {
363 	netdev_name_node_del(name_node);
364 	list_del(&name_node->list);
365 	call_rcu(&name_node->rcu, netdev_name_node_alt_free);
366 }
367 
368 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
369 {
370 	struct netdev_name_node *name_node;
371 	struct net *net = dev_net(dev);
372 
373 	name_node = netdev_name_node_lookup(net, name);
374 	if (!name_node)
375 		return -ENOENT;
376 	/* lookup might have found our primary name or a name belonging
377 	 * to another device.
378 	 */
379 	if (name_node == dev->name_node || name_node->dev != dev)
380 		return -EINVAL;
381 
382 	__netdev_name_node_alt_destroy(name_node);
383 	return 0;
384 }
385 
386 static void netdev_name_node_alt_flush(struct net_device *dev)
387 {
388 	struct netdev_name_node *name_node, *tmp;
389 
390 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list) {
391 		list_del(&name_node->list);
392 		netdev_name_node_alt_free(&name_node->rcu);
393 	}
394 }
395 
396 /* Device list insertion */
397 static void list_netdevice(struct net_device *dev)
398 {
399 	struct netdev_name_node *name_node;
400 	struct net *net = dev_net(dev);
401 
402 	ASSERT_RTNL();
403 
404 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
405 	netdev_name_node_add(net, dev->name_node);
406 	hlist_add_head_rcu(&dev->index_hlist,
407 			   dev_index_hash(net, dev->ifindex));
408 
409 	netdev_for_each_altname(dev, name_node)
410 		netdev_name_node_add(net, name_node);
411 
412 	/* We reserved the ifindex, this can't fail */
413 	WARN_ON(xa_store(&net->dev_by_index, dev->ifindex, dev, GFP_KERNEL));
414 
415 	dev_base_seq_inc(net);
416 }
417 
418 /* Device list removal
419  * caller must respect a RCU grace period before freeing/reusing dev
420  */
421 static void unlist_netdevice(struct net_device *dev)
422 {
423 	struct netdev_name_node *name_node;
424 	struct net *net = dev_net(dev);
425 
426 	ASSERT_RTNL();
427 
428 	xa_erase(&net->dev_by_index, dev->ifindex);
429 
430 	netdev_for_each_altname(dev, name_node)
431 		netdev_name_node_del(name_node);
432 
433 	/* Unlink dev from the device chain */
434 	list_del_rcu(&dev->dev_list);
435 	netdev_name_node_del(dev->name_node);
436 	hlist_del_rcu(&dev->index_hlist);
437 
438 	dev_base_seq_inc(dev_net(dev));
439 }
440 
441 /*
442  *	Our notifier list
443  */
444 
445 static RAW_NOTIFIER_HEAD(netdev_chain);
446 
447 /*
448  *	Device drivers call our routines to queue packets here. We empty the
449  *	queue in the local softnet handler.
450  */
451 
452 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data) = {
453 	.process_queue_bh_lock = INIT_LOCAL_LOCK(process_queue_bh_lock),
454 };
455 EXPORT_PER_CPU_SYMBOL(softnet_data);
456 
457 /* Page_pool has a lockless array/stack to alloc/recycle pages.
458  * PP consumers must pay attention to run APIs in the appropriate context
459  * (e.g. NAPI context).
460  */
461 static DEFINE_PER_CPU(struct page_pool *, system_page_pool);
462 
463 #ifdef CONFIG_LOCKDEP
464 /*
465  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
466  * according to dev->type
467  */
468 static const unsigned short netdev_lock_type[] = {
469 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
470 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
471 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
472 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
473 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
474 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
475 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
476 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
477 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
478 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
479 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
480 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
481 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
482 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
483 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
484 
485 static const char *const netdev_lock_name[] = {
486 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
487 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
488 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
489 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
490 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
491 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
492 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
493 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
494 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
495 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
496 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
497 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
498 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
499 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
500 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
501 
502 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
503 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
504 
505 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
506 {
507 	int i;
508 
509 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
510 		if (netdev_lock_type[i] == dev_type)
511 			return i;
512 	/* the last key is used by default */
513 	return ARRAY_SIZE(netdev_lock_type) - 1;
514 }
515 
516 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
517 						 unsigned short dev_type)
518 {
519 	int i;
520 
521 	i = netdev_lock_pos(dev_type);
522 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
523 				   netdev_lock_name[i]);
524 }
525 
526 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
527 {
528 	int i;
529 
530 	i = netdev_lock_pos(dev->type);
531 	lockdep_set_class_and_name(&dev->addr_list_lock,
532 				   &netdev_addr_lock_key[i],
533 				   netdev_lock_name[i]);
534 }
535 #else
536 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
537 						 unsigned short dev_type)
538 {
539 }
540 
541 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
542 {
543 }
544 #endif
545 
546 /*******************************************************************************
547  *
548  *		Protocol management and registration routines
549  *
550  *******************************************************************************/
551 
552 
553 /*
554  *	Add a protocol ID to the list. Now that the input handler is
555  *	smarter we can dispense with all the messy stuff that used to be
556  *	here.
557  *
558  *	BEWARE!!! Protocol handlers, mangling input packets,
559  *	MUST BE last in hash buckets and checking protocol handlers
560  *	MUST start from promiscuous ptype_all chain in net_bh.
561  *	It is true now, do not change it.
562  *	Explanation follows: if protocol handler, mangling packet, will
563  *	be the first on list, it is not able to sense, that packet
564  *	is cloned and should be copied-on-write, so that it will
565  *	change it and subsequent readers will get broken packet.
566  *							--ANK (980803)
567  */
568 
569 static inline struct list_head *ptype_head(const struct packet_type *pt)
570 {
571 	if (pt->type == htons(ETH_P_ALL))
572 		return pt->dev ? &pt->dev->ptype_all : &net_hotdata.ptype_all;
573 	else
574 		return pt->dev ? &pt->dev->ptype_specific :
575 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
576 }
577 
578 /**
579  *	dev_add_pack - add packet handler
580  *	@pt: packet type declaration
581  *
582  *	Add a protocol handler to the networking stack. The passed &packet_type
583  *	is linked into kernel lists and may not be freed until it has been
584  *	removed from the kernel lists.
585  *
586  *	This call does not sleep therefore it can not
587  *	guarantee all CPU's that are in middle of receiving packets
588  *	will see the new packet type (until the next received packet).
589  */
590 
591 void dev_add_pack(struct packet_type *pt)
592 {
593 	struct list_head *head = ptype_head(pt);
594 
595 	spin_lock(&ptype_lock);
596 	list_add_rcu(&pt->list, head);
597 	spin_unlock(&ptype_lock);
598 }
599 EXPORT_SYMBOL(dev_add_pack);
600 
601 /**
602  *	__dev_remove_pack	 - remove packet handler
603  *	@pt: packet type declaration
604  *
605  *	Remove a protocol handler that was previously added to the kernel
606  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
607  *	from the kernel lists and can be freed or reused once this function
608  *	returns.
609  *
610  *      The packet type might still be in use by receivers
611  *	and must not be freed until after all the CPU's have gone
612  *	through a quiescent state.
613  */
614 void __dev_remove_pack(struct packet_type *pt)
615 {
616 	struct list_head *head = ptype_head(pt);
617 	struct packet_type *pt1;
618 
619 	spin_lock(&ptype_lock);
620 
621 	list_for_each_entry(pt1, head, list) {
622 		if (pt == pt1) {
623 			list_del_rcu(&pt->list);
624 			goto out;
625 		}
626 	}
627 
628 	pr_warn("dev_remove_pack: %p not found\n", pt);
629 out:
630 	spin_unlock(&ptype_lock);
631 }
632 EXPORT_SYMBOL(__dev_remove_pack);
633 
634 /**
635  *	dev_remove_pack	 - remove packet handler
636  *	@pt: packet type declaration
637  *
638  *	Remove a protocol handler that was previously added to the kernel
639  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
640  *	from the kernel lists and can be freed or reused once this function
641  *	returns.
642  *
643  *	This call sleeps to guarantee that no CPU is looking at the packet
644  *	type after return.
645  */
646 void dev_remove_pack(struct packet_type *pt)
647 {
648 	__dev_remove_pack(pt);
649 
650 	synchronize_net();
651 }
652 EXPORT_SYMBOL(dev_remove_pack);
653 
654 
655 /*******************************************************************************
656  *
657  *			    Device Interface Subroutines
658  *
659  *******************************************************************************/
660 
661 /**
662  *	dev_get_iflink	- get 'iflink' value of a interface
663  *	@dev: targeted interface
664  *
665  *	Indicates the ifindex the interface is linked to.
666  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
667  */
668 
669 int dev_get_iflink(const struct net_device *dev)
670 {
671 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
672 		return dev->netdev_ops->ndo_get_iflink(dev);
673 
674 	return READ_ONCE(dev->ifindex);
675 }
676 EXPORT_SYMBOL(dev_get_iflink);
677 
678 /**
679  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
680  *	@dev: targeted interface
681  *	@skb: The packet.
682  *
683  *	For better visibility of tunnel traffic OVS needs to retrieve
684  *	egress tunnel information for a packet. Following API allows
685  *	user to get this info.
686  */
687 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
688 {
689 	struct ip_tunnel_info *info;
690 
691 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
692 		return -EINVAL;
693 
694 	info = skb_tunnel_info_unclone(skb);
695 	if (!info)
696 		return -ENOMEM;
697 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
698 		return -EINVAL;
699 
700 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
701 }
702 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
703 
704 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
705 {
706 	int k = stack->num_paths++;
707 
708 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
709 		return NULL;
710 
711 	return &stack->path[k];
712 }
713 
714 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
715 			  struct net_device_path_stack *stack)
716 {
717 	const struct net_device *last_dev;
718 	struct net_device_path_ctx ctx = {
719 		.dev	= dev,
720 	};
721 	struct net_device_path *path;
722 	int ret = 0;
723 
724 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
725 	stack->num_paths = 0;
726 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
727 		last_dev = ctx.dev;
728 		path = dev_fwd_path(stack);
729 		if (!path)
730 			return -1;
731 
732 		memset(path, 0, sizeof(struct net_device_path));
733 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
734 		if (ret < 0)
735 			return -1;
736 
737 		if (WARN_ON_ONCE(last_dev == ctx.dev))
738 			return -1;
739 	}
740 
741 	if (!ctx.dev)
742 		return ret;
743 
744 	path = dev_fwd_path(stack);
745 	if (!path)
746 		return -1;
747 	path->type = DEV_PATH_ETHERNET;
748 	path->dev = ctx.dev;
749 
750 	return ret;
751 }
752 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
753 
754 /**
755  *	__dev_get_by_name	- find a device by its name
756  *	@net: the applicable net namespace
757  *	@name: name to find
758  *
759  *	Find an interface by name. Must be called under RTNL semaphore.
760  *	If the name is found a pointer to the device is returned.
761  *	If the name is not found then %NULL is returned. The
762  *	reference counters are not incremented so the caller must be
763  *	careful with locks.
764  */
765 
766 struct net_device *__dev_get_by_name(struct net *net, const char *name)
767 {
768 	struct netdev_name_node *node_name;
769 
770 	node_name = netdev_name_node_lookup(net, name);
771 	return node_name ? node_name->dev : NULL;
772 }
773 EXPORT_SYMBOL(__dev_get_by_name);
774 
775 /**
776  * dev_get_by_name_rcu	- find a device by its name
777  * @net: the applicable net namespace
778  * @name: name to find
779  *
780  * Find an interface by name.
781  * If the name is found a pointer to the device is returned.
782  * If the name is not found then %NULL is returned.
783  * The reference counters are not incremented so the caller must be
784  * careful with locks. The caller must hold RCU lock.
785  */
786 
787 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
788 {
789 	struct netdev_name_node *node_name;
790 
791 	node_name = netdev_name_node_lookup_rcu(net, name);
792 	return node_name ? node_name->dev : NULL;
793 }
794 EXPORT_SYMBOL(dev_get_by_name_rcu);
795 
796 /* Deprecated for new users, call netdev_get_by_name() instead */
797 struct net_device *dev_get_by_name(struct net *net, const char *name)
798 {
799 	struct net_device *dev;
800 
801 	rcu_read_lock();
802 	dev = dev_get_by_name_rcu(net, name);
803 	dev_hold(dev);
804 	rcu_read_unlock();
805 	return dev;
806 }
807 EXPORT_SYMBOL(dev_get_by_name);
808 
809 /**
810  *	netdev_get_by_name() - find a device by its name
811  *	@net: the applicable net namespace
812  *	@name: name to find
813  *	@tracker: tracking object for the acquired reference
814  *	@gfp: allocation flags for the tracker
815  *
816  *	Find an interface by name. This can be called from any
817  *	context and does its own locking. The returned handle has
818  *	the usage count incremented and the caller must use netdev_put() to
819  *	release it when it is no longer needed. %NULL is returned if no
820  *	matching device is found.
821  */
822 struct net_device *netdev_get_by_name(struct net *net, const char *name,
823 				      netdevice_tracker *tracker, gfp_t gfp)
824 {
825 	struct net_device *dev;
826 
827 	dev = dev_get_by_name(net, name);
828 	if (dev)
829 		netdev_tracker_alloc(dev, tracker, gfp);
830 	return dev;
831 }
832 EXPORT_SYMBOL(netdev_get_by_name);
833 
834 /**
835  *	__dev_get_by_index - find a device by its ifindex
836  *	@net: the applicable net namespace
837  *	@ifindex: index of device
838  *
839  *	Search for an interface by index. Returns %NULL if the device
840  *	is not found or a pointer to the device. The device has not
841  *	had its reference counter increased so the caller must be careful
842  *	about locking. The caller must hold the RTNL semaphore.
843  */
844 
845 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
846 {
847 	struct net_device *dev;
848 	struct hlist_head *head = dev_index_hash(net, ifindex);
849 
850 	hlist_for_each_entry(dev, head, index_hlist)
851 		if (dev->ifindex == ifindex)
852 			return dev;
853 
854 	return NULL;
855 }
856 EXPORT_SYMBOL(__dev_get_by_index);
857 
858 /**
859  *	dev_get_by_index_rcu - find a device by its ifindex
860  *	@net: the applicable net namespace
861  *	@ifindex: index of device
862  *
863  *	Search for an interface by index. Returns %NULL if the device
864  *	is not found or a pointer to the device. The device has not
865  *	had its reference counter increased so the caller must be careful
866  *	about locking. The caller must hold RCU lock.
867  */
868 
869 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
870 {
871 	struct net_device *dev;
872 	struct hlist_head *head = dev_index_hash(net, ifindex);
873 
874 	hlist_for_each_entry_rcu(dev, head, index_hlist)
875 		if (dev->ifindex == ifindex)
876 			return dev;
877 
878 	return NULL;
879 }
880 EXPORT_SYMBOL(dev_get_by_index_rcu);
881 
882 /* Deprecated for new users, call netdev_get_by_index() instead */
883 struct net_device *dev_get_by_index(struct net *net, int ifindex)
884 {
885 	struct net_device *dev;
886 
887 	rcu_read_lock();
888 	dev = dev_get_by_index_rcu(net, ifindex);
889 	dev_hold(dev);
890 	rcu_read_unlock();
891 	return dev;
892 }
893 EXPORT_SYMBOL(dev_get_by_index);
894 
895 /**
896  *	netdev_get_by_index() - find a device by its ifindex
897  *	@net: the applicable net namespace
898  *	@ifindex: index of device
899  *	@tracker: tracking object for the acquired reference
900  *	@gfp: allocation flags for the tracker
901  *
902  *	Search for an interface by index. Returns NULL if the device
903  *	is not found or a pointer to the device. The device returned has
904  *	had a reference added and the pointer is safe until the user calls
905  *	netdev_put() to indicate they have finished with it.
906  */
907 struct net_device *netdev_get_by_index(struct net *net, int ifindex,
908 				       netdevice_tracker *tracker, gfp_t gfp)
909 {
910 	struct net_device *dev;
911 
912 	dev = dev_get_by_index(net, ifindex);
913 	if (dev)
914 		netdev_tracker_alloc(dev, tracker, gfp);
915 	return dev;
916 }
917 EXPORT_SYMBOL(netdev_get_by_index);
918 
919 /**
920  *	dev_get_by_napi_id - find a device by napi_id
921  *	@napi_id: ID of the NAPI struct
922  *
923  *	Search for an interface by NAPI ID. Returns %NULL if the device
924  *	is not found or a pointer to the device. The device has not had
925  *	its reference counter increased so the caller must be careful
926  *	about locking. The caller must hold RCU lock.
927  */
928 
929 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
930 {
931 	struct napi_struct *napi;
932 
933 	WARN_ON_ONCE(!rcu_read_lock_held());
934 
935 	if (napi_id < MIN_NAPI_ID)
936 		return NULL;
937 
938 	napi = napi_by_id(napi_id);
939 
940 	return napi ? napi->dev : NULL;
941 }
942 EXPORT_SYMBOL(dev_get_by_napi_id);
943 
944 static DEFINE_SEQLOCK(netdev_rename_lock);
945 
946 void netdev_copy_name(struct net_device *dev, char *name)
947 {
948 	unsigned int seq;
949 
950 	do {
951 		seq = read_seqbegin(&netdev_rename_lock);
952 		strscpy(name, dev->name, IFNAMSIZ);
953 	} while (read_seqretry(&netdev_rename_lock, seq));
954 }
955 
956 /**
957  *	netdev_get_name - get a netdevice name, knowing its ifindex.
958  *	@net: network namespace
959  *	@name: a pointer to the buffer where the name will be stored.
960  *	@ifindex: the ifindex of the interface to get the name from.
961  */
962 int netdev_get_name(struct net *net, char *name, int ifindex)
963 {
964 	struct net_device *dev;
965 	int ret;
966 
967 	rcu_read_lock();
968 
969 	dev = dev_get_by_index_rcu(net, ifindex);
970 	if (!dev) {
971 		ret = -ENODEV;
972 		goto out;
973 	}
974 
975 	netdev_copy_name(dev, name);
976 
977 	ret = 0;
978 out:
979 	rcu_read_unlock();
980 	return ret;
981 }
982 
983 /**
984  *	dev_getbyhwaddr_rcu - find a device by its hardware address
985  *	@net: the applicable net namespace
986  *	@type: media type of device
987  *	@ha: hardware address
988  *
989  *	Search for an interface by MAC address. Returns NULL if the device
990  *	is not found or a pointer to the device.
991  *	The caller must hold RCU or RTNL.
992  *	The returned device has not had its ref count increased
993  *	and the caller must therefore be careful about locking
994  *
995  */
996 
997 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
998 				       const char *ha)
999 {
1000 	struct net_device *dev;
1001 
1002 	for_each_netdev_rcu(net, dev)
1003 		if (dev->type == type &&
1004 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
1005 			return dev;
1006 
1007 	return NULL;
1008 }
1009 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
1010 
1011 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
1012 {
1013 	struct net_device *dev, *ret = NULL;
1014 
1015 	rcu_read_lock();
1016 	for_each_netdev_rcu(net, dev)
1017 		if (dev->type == type) {
1018 			dev_hold(dev);
1019 			ret = dev;
1020 			break;
1021 		}
1022 	rcu_read_unlock();
1023 	return ret;
1024 }
1025 EXPORT_SYMBOL(dev_getfirstbyhwtype);
1026 
1027 /**
1028  *	__dev_get_by_flags - find any device with given flags
1029  *	@net: the applicable net namespace
1030  *	@if_flags: IFF_* values
1031  *	@mask: bitmask of bits in if_flags to check
1032  *
1033  *	Search for any interface with the given flags. Returns NULL if a device
1034  *	is not found or a pointer to the device. Must be called inside
1035  *	rtnl_lock(), and result refcount is unchanged.
1036  */
1037 
1038 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1039 				      unsigned short mask)
1040 {
1041 	struct net_device *dev, *ret;
1042 
1043 	ASSERT_RTNL();
1044 
1045 	ret = NULL;
1046 	for_each_netdev(net, dev) {
1047 		if (((dev->flags ^ if_flags) & mask) == 0) {
1048 			ret = dev;
1049 			break;
1050 		}
1051 	}
1052 	return ret;
1053 }
1054 EXPORT_SYMBOL(__dev_get_by_flags);
1055 
1056 /**
1057  *	dev_valid_name - check if name is okay for network device
1058  *	@name: name string
1059  *
1060  *	Network device names need to be valid file names to
1061  *	allow sysfs to work.  We also disallow any kind of
1062  *	whitespace.
1063  */
1064 bool dev_valid_name(const char *name)
1065 {
1066 	if (*name == '\0')
1067 		return false;
1068 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1069 		return false;
1070 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1071 		return false;
1072 
1073 	while (*name) {
1074 		if (*name == '/' || *name == ':' || isspace(*name))
1075 			return false;
1076 		name++;
1077 	}
1078 	return true;
1079 }
1080 EXPORT_SYMBOL(dev_valid_name);
1081 
1082 /**
1083  *	__dev_alloc_name - allocate a name for a device
1084  *	@net: network namespace to allocate the device name in
1085  *	@name: name format string
1086  *	@res: result name string
1087  *
1088  *	Passed a format string - eg "lt%d" it will try and find a suitable
1089  *	id. It scans list of devices to build up a free map, then chooses
1090  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1091  *	while allocating the name and adding the device in order to avoid
1092  *	duplicates.
1093  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1094  *	Returns the number of the unit assigned or a negative errno code.
1095  */
1096 
1097 static int __dev_alloc_name(struct net *net, const char *name, char *res)
1098 {
1099 	int i = 0;
1100 	const char *p;
1101 	const int max_netdevices = 8*PAGE_SIZE;
1102 	unsigned long *inuse;
1103 	struct net_device *d;
1104 	char buf[IFNAMSIZ];
1105 
1106 	/* Verify the string as this thing may have come from the user.
1107 	 * There must be one "%d" and no other "%" characters.
1108 	 */
1109 	p = strchr(name, '%');
1110 	if (!p || p[1] != 'd' || strchr(p + 2, '%'))
1111 		return -EINVAL;
1112 
1113 	/* Use one page as a bit array of possible slots */
1114 	inuse = bitmap_zalloc(max_netdevices, GFP_ATOMIC);
1115 	if (!inuse)
1116 		return -ENOMEM;
1117 
1118 	for_each_netdev(net, d) {
1119 		struct netdev_name_node *name_node;
1120 
1121 		netdev_for_each_altname(d, name_node) {
1122 			if (!sscanf(name_node->name, name, &i))
1123 				continue;
1124 			if (i < 0 || i >= max_netdevices)
1125 				continue;
1126 
1127 			/* avoid cases where sscanf is not exact inverse of printf */
1128 			snprintf(buf, IFNAMSIZ, name, i);
1129 			if (!strncmp(buf, name_node->name, IFNAMSIZ))
1130 				__set_bit(i, inuse);
1131 		}
1132 		if (!sscanf(d->name, name, &i))
1133 			continue;
1134 		if (i < 0 || i >= max_netdevices)
1135 			continue;
1136 
1137 		/* avoid cases where sscanf is not exact inverse of printf */
1138 		snprintf(buf, IFNAMSIZ, name, i);
1139 		if (!strncmp(buf, d->name, IFNAMSIZ))
1140 			__set_bit(i, inuse);
1141 	}
1142 
1143 	i = find_first_zero_bit(inuse, max_netdevices);
1144 	bitmap_free(inuse);
1145 	if (i == max_netdevices)
1146 		return -ENFILE;
1147 
1148 	/* 'res' and 'name' could overlap, use 'buf' as an intermediate buffer */
1149 	strscpy(buf, name, IFNAMSIZ);
1150 	snprintf(res, IFNAMSIZ, buf, i);
1151 	return i;
1152 }
1153 
1154 /* Returns negative errno or allocated unit id (see __dev_alloc_name()) */
1155 static int dev_prep_valid_name(struct net *net, struct net_device *dev,
1156 			       const char *want_name, char *out_name,
1157 			       int dup_errno)
1158 {
1159 	if (!dev_valid_name(want_name))
1160 		return -EINVAL;
1161 
1162 	if (strchr(want_name, '%'))
1163 		return __dev_alloc_name(net, want_name, out_name);
1164 
1165 	if (netdev_name_in_use(net, want_name))
1166 		return -dup_errno;
1167 	if (out_name != want_name)
1168 		strscpy(out_name, want_name, IFNAMSIZ);
1169 	return 0;
1170 }
1171 
1172 /**
1173  *	dev_alloc_name - allocate a name for a device
1174  *	@dev: device
1175  *	@name: name format string
1176  *
1177  *	Passed a format string - eg "lt%d" it will try and find a suitable
1178  *	id. It scans list of devices to build up a free map, then chooses
1179  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1180  *	while allocating the name and adding the device in order to avoid
1181  *	duplicates.
1182  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1183  *	Returns the number of the unit assigned or a negative errno code.
1184  */
1185 
1186 int dev_alloc_name(struct net_device *dev, const char *name)
1187 {
1188 	return dev_prep_valid_name(dev_net(dev), dev, name, dev->name, ENFILE);
1189 }
1190 EXPORT_SYMBOL(dev_alloc_name);
1191 
1192 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1193 			      const char *name)
1194 {
1195 	int ret;
1196 
1197 	ret = dev_prep_valid_name(net, dev, name, dev->name, EEXIST);
1198 	return ret < 0 ? ret : 0;
1199 }
1200 
1201 /**
1202  *	dev_change_name - change name of a device
1203  *	@dev: device
1204  *	@newname: name (or format string) must be at least IFNAMSIZ
1205  *
1206  *	Change name of a device, can pass format strings "eth%d".
1207  *	for wildcarding.
1208  */
1209 int dev_change_name(struct net_device *dev, const char *newname)
1210 {
1211 	unsigned char old_assign_type;
1212 	char oldname[IFNAMSIZ];
1213 	int err = 0;
1214 	int ret;
1215 	struct net *net;
1216 
1217 	ASSERT_RTNL();
1218 	BUG_ON(!dev_net(dev));
1219 
1220 	net = dev_net(dev);
1221 
1222 	down_write(&devnet_rename_sem);
1223 
1224 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1225 		up_write(&devnet_rename_sem);
1226 		return 0;
1227 	}
1228 
1229 	memcpy(oldname, dev->name, IFNAMSIZ);
1230 
1231 	write_seqlock_bh(&netdev_rename_lock);
1232 	err = dev_get_valid_name(net, dev, newname);
1233 	write_sequnlock_bh(&netdev_rename_lock);
1234 
1235 	if (err < 0) {
1236 		up_write(&devnet_rename_sem);
1237 		return err;
1238 	}
1239 
1240 	if (oldname[0] && !strchr(oldname, '%'))
1241 		netdev_info(dev, "renamed from %s%s\n", oldname,
1242 			    dev->flags & IFF_UP ? " (while UP)" : "");
1243 
1244 	old_assign_type = dev->name_assign_type;
1245 	WRITE_ONCE(dev->name_assign_type, NET_NAME_RENAMED);
1246 
1247 rollback:
1248 	ret = device_rename(&dev->dev, dev->name);
1249 	if (ret) {
1250 		memcpy(dev->name, oldname, IFNAMSIZ);
1251 		WRITE_ONCE(dev->name_assign_type, old_assign_type);
1252 		up_write(&devnet_rename_sem);
1253 		return ret;
1254 	}
1255 
1256 	up_write(&devnet_rename_sem);
1257 
1258 	netdev_adjacent_rename_links(dev, oldname);
1259 
1260 	netdev_name_node_del(dev->name_node);
1261 
1262 	synchronize_net();
1263 
1264 	netdev_name_node_add(net, dev->name_node);
1265 
1266 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1267 	ret = notifier_to_errno(ret);
1268 
1269 	if (ret) {
1270 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1271 		if (err >= 0) {
1272 			err = ret;
1273 			down_write(&devnet_rename_sem);
1274 			write_seqlock_bh(&netdev_rename_lock);
1275 			memcpy(dev->name, oldname, IFNAMSIZ);
1276 			write_sequnlock_bh(&netdev_rename_lock);
1277 			memcpy(oldname, newname, IFNAMSIZ);
1278 			WRITE_ONCE(dev->name_assign_type, old_assign_type);
1279 			old_assign_type = NET_NAME_RENAMED;
1280 			goto rollback;
1281 		} else {
1282 			netdev_err(dev, "name change rollback failed: %d\n",
1283 				   ret);
1284 		}
1285 	}
1286 
1287 	return err;
1288 }
1289 
1290 /**
1291  *	dev_set_alias - change ifalias of a device
1292  *	@dev: device
1293  *	@alias: name up to IFALIASZ
1294  *	@len: limit of bytes to copy from info
1295  *
1296  *	Set ifalias for a device,
1297  */
1298 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1299 {
1300 	struct dev_ifalias *new_alias = NULL;
1301 
1302 	if (len >= IFALIASZ)
1303 		return -EINVAL;
1304 
1305 	if (len) {
1306 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1307 		if (!new_alias)
1308 			return -ENOMEM;
1309 
1310 		memcpy(new_alias->ifalias, alias, len);
1311 		new_alias->ifalias[len] = 0;
1312 	}
1313 
1314 	mutex_lock(&ifalias_mutex);
1315 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1316 					mutex_is_locked(&ifalias_mutex));
1317 	mutex_unlock(&ifalias_mutex);
1318 
1319 	if (new_alias)
1320 		kfree_rcu(new_alias, rcuhead);
1321 
1322 	return len;
1323 }
1324 EXPORT_SYMBOL(dev_set_alias);
1325 
1326 /**
1327  *	dev_get_alias - get ifalias of a device
1328  *	@dev: device
1329  *	@name: buffer to store name of ifalias
1330  *	@len: size of buffer
1331  *
1332  *	get ifalias for a device.  Caller must make sure dev cannot go
1333  *	away,  e.g. rcu read lock or own a reference count to device.
1334  */
1335 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1336 {
1337 	const struct dev_ifalias *alias;
1338 	int ret = 0;
1339 
1340 	rcu_read_lock();
1341 	alias = rcu_dereference(dev->ifalias);
1342 	if (alias)
1343 		ret = snprintf(name, len, "%s", alias->ifalias);
1344 	rcu_read_unlock();
1345 
1346 	return ret;
1347 }
1348 
1349 /**
1350  *	netdev_features_change - device changes features
1351  *	@dev: device to cause notification
1352  *
1353  *	Called to indicate a device has changed features.
1354  */
1355 void netdev_features_change(struct net_device *dev)
1356 {
1357 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1358 }
1359 EXPORT_SYMBOL(netdev_features_change);
1360 
1361 /**
1362  *	netdev_state_change - device changes state
1363  *	@dev: device to cause notification
1364  *
1365  *	Called to indicate a device has changed state. This function calls
1366  *	the notifier chains for netdev_chain and sends a NEWLINK message
1367  *	to the routing socket.
1368  */
1369 void netdev_state_change(struct net_device *dev)
1370 {
1371 	if (dev->flags & IFF_UP) {
1372 		struct netdev_notifier_change_info change_info = {
1373 			.info.dev = dev,
1374 		};
1375 
1376 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1377 					      &change_info.info);
1378 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1379 	}
1380 }
1381 EXPORT_SYMBOL(netdev_state_change);
1382 
1383 /**
1384  * __netdev_notify_peers - notify network peers about existence of @dev,
1385  * to be called when rtnl lock is already held.
1386  * @dev: network device
1387  *
1388  * Generate traffic such that interested network peers are aware of
1389  * @dev, such as by generating a gratuitous ARP. This may be used when
1390  * a device wants to inform the rest of the network about some sort of
1391  * reconfiguration such as a failover event or virtual machine
1392  * migration.
1393  */
1394 void __netdev_notify_peers(struct net_device *dev)
1395 {
1396 	ASSERT_RTNL();
1397 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1398 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1399 }
1400 EXPORT_SYMBOL(__netdev_notify_peers);
1401 
1402 /**
1403  * netdev_notify_peers - notify network peers about existence of @dev
1404  * @dev: network device
1405  *
1406  * Generate traffic such that interested network peers are aware of
1407  * @dev, such as by generating a gratuitous ARP. This may be used when
1408  * a device wants to inform the rest of the network about some sort of
1409  * reconfiguration such as a failover event or virtual machine
1410  * migration.
1411  */
1412 void netdev_notify_peers(struct net_device *dev)
1413 {
1414 	rtnl_lock();
1415 	__netdev_notify_peers(dev);
1416 	rtnl_unlock();
1417 }
1418 EXPORT_SYMBOL(netdev_notify_peers);
1419 
1420 static int napi_threaded_poll(void *data);
1421 
1422 static int napi_kthread_create(struct napi_struct *n)
1423 {
1424 	int err = 0;
1425 
1426 	/* Create and wake up the kthread once to put it in
1427 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1428 	 * warning and work with loadavg.
1429 	 */
1430 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1431 				n->dev->name, n->napi_id);
1432 	if (IS_ERR(n->thread)) {
1433 		err = PTR_ERR(n->thread);
1434 		pr_err("kthread_run failed with err %d\n", err);
1435 		n->thread = NULL;
1436 	}
1437 
1438 	return err;
1439 }
1440 
1441 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1442 {
1443 	const struct net_device_ops *ops = dev->netdev_ops;
1444 	int ret;
1445 
1446 	ASSERT_RTNL();
1447 	dev_addr_check(dev);
1448 
1449 	if (!netif_device_present(dev)) {
1450 		/* may be detached because parent is runtime-suspended */
1451 		if (dev->dev.parent)
1452 			pm_runtime_resume(dev->dev.parent);
1453 		if (!netif_device_present(dev))
1454 			return -ENODEV;
1455 	}
1456 
1457 	/* Block netpoll from trying to do any rx path servicing.
1458 	 * If we don't do this there is a chance ndo_poll_controller
1459 	 * or ndo_poll may be running while we open the device
1460 	 */
1461 	netpoll_poll_disable(dev);
1462 
1463 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1464 	ret = notifier_to_errno(ret);
1465 	if (ret)
1466 		return ret;
1467 
1468 	set_bit(__LINK_STATE_START, &dev->state);
1469 
1470 	if (ops->ndo_validate_addr)
1471 		ret = ops->ndo_validate_addr(dev);
1472 
1473 	if (!ret && ops->ndo_open)
1474 		ret = ops->ndo_open(dev);
1475 
1476 	netpoll_poll_enable(dev);
1477 
1478 	if (ret)
1479 		clear_bit(__LINK_STATE_START, &dev->state);
1480 	else {
1481 		dev->flags |= IFF_UP;
1482 		dev_set_rx_mode(dev);
1483 		dev_activate(dev);
1484 		add_device_randomness(dev->dev_addr, dev->addr_len);
1485 	}
1486 
1487 	return ret;
1488 }
1489 
1490 /**
1491  *	dev_open	- prepare an interface for use.
1492  *	@dev: device to open
1493  *	@extack: netlink extended ack
1494  *
1495  *	Takes a device from down to up state. The device's private open
1496  *	function is invoked and then the multicast lists are loaded. Finally
1497  *	the device is moved into the up state and a %NETDEV_UP message is
1498  *	sent to the netdev notifier chain.
1499  *
1500  *	Calling this function on an active interface is a nop. On a failure
1501  *	a negative errno code is returned.
1502  */
1503 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1504 {
1505 	int ret;
1506 
1507 	if (dev->flags & IFF_UP)
1508 		return 0;
1509 
1510 	ret = __dev_open(dev, extack);
1511 	if (ret < 0)
1512 		return ret;
1513 
1514 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1515 	call_netdevice_notifiers(NETDEV_UP, dev);
1516 
1517 	return ret;
1518 }
1519 EXPORT_SYMBOL(dev_open);
1520 
1521 static void __dev_close_many(struct list_head *head)
1522 {
1523 	struct net_device *dev;
1524 
1525 	ASSERT_RTNL();
1526 	might_sleep();
1527 
1528 	list_for_each_entry(dev, head, close_list) {
1529 		/* Temporarily disable netpoll until the interface is down */
1530 		netpoll_poll_disable(dev);
1531 
1532 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1533 
1534 		clear_bit(__LINK_STATE_START, &dev->state);
1535 
1536 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1537 		 * can be even on different cpu. So just clear netif_running().
1538 		 *
1539 		 * dev->stop() will invoke napi_disable() on all of it's
1540 		 * napi_struct instances on this device.
1541 		 */
1542 		smp_mb__after_atomic(); /* Commit netif_running(). */
1543 	}
1544 
1545 	dev_deactivate_many(head);
1546 
1547 	list_for_each_entry(dev, head, close_list) {
1548 		const struct net_device_ops *ops = dev->netdev_ops;
1549 
1550 		/*
1551 		 *	Call the device specific close. This cannot fail.
1552 		 *	Only if device is UP
1553 		 *
1554 		 *	We allow it to be called even after a DETACH hot-plug
1555 		 *	event.
1556 		 */
1557 		if (ops->ndo_stop)
1558 			ops->ndo_stop(dev);
1559 
1560 		dev->flags &= ~IFF_UP;
1561 		netpoll_poll_enable(dev);
1562 	}
1563 }
1564 
1565 static void __dev_close(struct net_device *dev)
1566 {
1567 	LIST_HEAD(single);
1568 
1569 	list_add(&dev->close_list, &single);
1570 	__dev_close_many(&single);
1571 	list_del(&single);
1572 }
1573 
1574 void dev_close_many(struct list_head *head, bool unlink)
1575 {
1576 	struct net_device *dev, *tmp;
1577 
1578 	/* Remove the devices that don't need to be closed */
1579 	list_for_each_entry_safe(dev, tmp, head, close_list)
1580 		if (!(dev->flags & IFF_UP))
1581 			list_del_init(&dev->close_list);
1582 
1583 	__dev_close_many(head);
1584 
1585 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1586 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1587 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1588 		if (unlink)
1589 			list_del_init(&dev->close_list);
1590 	}
1591 }
1592 EXPORT_SYMBOL(dev_close_many);
1593 
1594 /**
1595  *	dev_close - shutdown an interface.
1596  *	@dev: device to shutdown
1597  *
1598  *	This function moves an active device into down state. A
1599  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1600  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1601  *	chain.
1602  */
1603 void dev_close(struct net_device *dev)
1604 {
1605 	if (dev->flags & IFF_UP) {
1606 		LIST_HEAD(single);
1607 
1608 		list_add(&dev->close_list, &single);
1609 		dev_close_many(&single, true);
1610 		list_del(&single);
1611 	}
1612 }
1613 EXPORT_SYMBOL(dev_close);
1614 
1615 
1616 /**
1617  *	dev_disable_lro - disable Large Receive Offload on a device
1618  *	@dev: device
1619  *
1620  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1621  *	called under RTNL.  This is needed if received packets may be
1622  *	forwarded to another interface.
1623  */
1624 void dev_disable_lro(struct net_device *dev)
1625 {
1626 	struct net_device *lower_dev;
1627 	struct list_head *iter;
1628 
1629 	dev->wanted_features &= ~NETIF_F_LRO;
1630 	netdev_update_features(dev);
1631 
1632 	if (unlikely(dev->features & NETIF_F_LRO))
1633 		netdev_WARN(dev, "failed to disable LRO!\n");
1634 
1635 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1636 		dev_disable_lro(lower_dev);
1637 }
1638 EXPORT_SYMBOL(dev_disable_lro);
1639 
1640 /**
1641  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1642  *	@dev: device
1643  *
1644  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1645  *	called under RTNL.  This is needed if Generic XDP is installed on
1646  *	the device.
1647  */
1648 static void dev_disable_gro_hw(struct net_device *dev)
1649 {
1650 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1651 	netdev_update_features(dev);
1652 
1653 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1654 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1655 }
1656 
1657 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1658 {
1659 #define N(val) 						\
1660 	case NETDEV_##val:				\
1661 		return "NETDEV_" __stringify(val);
1662 	switch (cmd) {
1663 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1664 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1665 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1666 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1667 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1668 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1669 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1670 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1671 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1672 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1673 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1674 	N(XDP_FEAT_CHANGE)
1675 	}
1676 #undef N
1677 	return "UNKNOWN_NETDEV_EVENT";
1678 }
1679 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1680 
1681 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1682 				   struct net_device *dev)
1683 {
1684 	struct netdev_notifier_info info = {
1685 		.dev = dev,
1686 	};
1687 
1688 	return nb->notifier_call(nb, val, &info);
1689 }
1690 
1691 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1692 					     struct net_device *dev)
1693 {
1694 	int err;
1695 
1696 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1697 	err = notifier_to_errno(err);
1698 	if (err)
1699 		return err;
1700 
1701 	if (!(dev->flags & IFF_UP))
1702 		return 0;
1703 
1704 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1705 	return 0;
1706 }
1707 
1708 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1709 						struct net_device *dev)
1710 {
1711 	if (dev->flags & IFF_UP) {
1712 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1713 					dev);
1714 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1715 	}
1716 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1717 }
1718 
1719 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1720 						 struct net *net)
1721 {
1722 	struct net_device *dev;
1723 	int err;
1724 
1725 	for_each_netdev(net, dev) {
1726 		err = call_netdevice_register_notifiers(nb, dev);
1727 		if (err)
1728 			goto rollback;
1729 	}
1730 	return 0;
1731 
1732 rollback:
1733 	for_each_netdev_continue_reverse(net, dev)
1734 		call_netdevice_unregister_notifiers(nb, dev);
1735 	return err;
1736 }
1737 
1738 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1739 						    struct net *net)
1740 {
1741 	struct net_device *dev;
1742 
1743 	for_each_netdev(net, dev)
1744 		call_netdevice_unregister_notifiers(nb, dev);
1745 }
1746 
1747 static int dev_boot_phase = 1;
1748 
1749 /**
1750  * register_netdevice_notifier - register a network notifier block
1751  * @nb: notifier
1752  *
1753  * Register a notifier to be called when network device events occur.
1754  * The notifier passed is linked into the kernel structures and must
1755  * not be reused until it has been unregistered. A negative errno code
1756  * is returned on a failure.
1757  *
1758  * When registered all registration and up events are replayed
1759  * to the new notifier to allow device to have a race free
1760  * view of the network device list.
1761  */
1762 
1763 int register_netdevice_notifier(struct notifier_block *nb)
1764 {
1765 	struct net *net;
1766 	int err;
1767 
1768 	/* Close race with setup_net() and cleanup_net() */
1769 	down_write(&pernet_ops_rwsem);
1770 	rtnl_lock();
1771 	err = raw_notifier_chain_register(&netdev_chain, nb);
1772 	if (err)
1773 		goto unlock;
1774 	if (dev_boot_phase)
1775 		goto unlock;
1776 	for_each_net(net) {
1777 		err = call_netdevice_register_net_notifiers(nb, net);
1778 		if (err)
1779 			goto rollback;
1780 	}
1781 
1782 unlock:
1783 	rtnl_unlock();
1784 	up_write(&pernet_ops_rwsem);
1785 	return err;
1786 
1787 rollback:
1788 	for_each_net_continue_reverse(net)
1789 		call_netdevice_unregister_net_notifiers(nb, net);
1790 
1791 	raw_notifier_chain_unregister(&netdev_chain, nb);
1792 	goto unlock;
1793 }
1794 EXPORT_SYMBOL(register_netdevice_notifier);
1795 
1796 /**
1797  * unregister_netdevice_notifier - unregister a network notifier block
1798  * @nb: notifier
1799  *
1800  * Unregister a notifier previously registered by
1801  * register_netdevice_notifier(). The notifier is unlinked into the
1802  * kernel structures and may then be reused. A negative errno code
1803  * is returned on a failure.
1804  *
1805  * After unregistering unregister and down device events are synthesized
1806  * for all devices on the device list to the removed notifier to remove
1807  * the need for special case cleanup code.
1808  */
1809 
1810 int unregister_netdevice_notifier(struct notifier_block *nb)
1811 {
1812 	struct net *net;
1813 	int err;
1814 
1815 	/* Close race with setup_net() and cleanup_net() */
1816 	down_write(&pernet_ops_rwsem);
1817 	rtnl_lock();
1818 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1819 	if (err)
1820 		goto unlock;
1821 
1822 	for_each_net(net)
1823 		call_netdevice_unregister_net_notifiers(nb, net);
1824 
1825 unlock:
1826 	rtnl_unlock();
1827 	up_write(&pernet_ops_rwsem);
1828 	return err;
1829 }
1830 EXPORT_SYMBOL(unregister_netdevice_notifier);
1831 
1832 static int __register_netdevice_notifier_net(struct net *net,
1833 					     struct notifier_block *nb,
1834 					     bool ignore_call_fail)
1835 {
1836 	int err;
1837 
1838 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1839 	if (err)
1840 		return err;
1841 	if (dev_boot_phase)
1842 		return 0;
1843 
1844 	err = call_netdevice_register_net_notifiers(nb, net);
1845 	if (err && !ignore_call_fail)
1846 		goto chain_unregister;
1847 
1848 	return 0;
1849 
1850 chain_unregister:
1851 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1852 	return err;
1853 }
1854 
1855 static int __unregister_netdevice_notifier_net(struct net *net,
1856 					       struct notifier_block *nb)
1857 {
1858 	int err;
1859 
1860 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1861 	if (err)
1862 		return err;
1863 
1864 	call_netdevice_unregister_net_notifiers(nb, net);
1865 	return 0;
1866 }
1867 
1868 /**
1869  * register_netdevice_notifier_net - register a per-netns network notifier block
1870  * @net: network namespace
1871  * @nb: notifier
1872  *
1873  * Register a notifier to be called when network device events occur.
1874  * The notifier passed is linked into the kernel structures and must
1875  * not be reused until it has been unregistered. A negative errno code
1876  * is returned on a failure.
1877  *
1878  * When registered all registration and up events are replayed
1879  * to the new notifier to allow device to have a race free
1880  * view of the network device list.
1881  */
1882 
1883 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1884 {
1885 	int err;
1886 
1887 	rtnl_lock();
1888 	err = __register_netdevice_notifier_net(net, nb, false);
1889 	rtnl_unlock();
1890 	return err;
1891 }
1892 EXPORT_SYMBOL(register_netdevice_notifier_net);
1893 
1894 /**
1895  * unregister_netdevice_notifier_net - unregister a per-netns
1896  *                                     network notifier block
1897  * @net: network namespace
1898  * @nb: notifier
1899  *
1900  * Unregister a notifier previously registered by
1901  * register_netdevice_notifier_net(). The notifier is unlinked from the
1902  * kernel structures and may then be reused. A negative errno code
1903  * is returned on a failure.
1904  *
1905  * After unregistering unregister and down device events are synthesized
1906  * for all devices on the device list to the removed notifier to remove
1907  * the need for special case cleanup code.
1908  */
1909 
1910 int unregister_netdevice_notifier_net(struct net *net,
1911 				      struct notifier_block *nb)
1912 {
1913 	int err;
1914 
1915 	rtnl_lock();
1916 	err = __unregister_netdevice_notifier_net(net, nb);
1917 	rtnl_unlock();
1918 	return err;
1919 }
1920 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1921 
1922 static void __move_netdevice_notifier_net(struct net *src_net,
1923 					  struct net *dst_net,
1924 					  struct notifier_block *nb)
1925 {
1926 	__unregister_netdevice_notifier_net(src_net, nb);
1927 	__register_netdevice_notifier_net(dst_net, nb, true);
1928 }
1929 
1930 int register_netdevice_notifier_dev_net(struct net_device *dev,
1931 					struct notifier_block *nb,
1932 					struct netdev_net_notifier *nn)
1933 {
1934 	int err;
1935 
1936 	rtnl_lock();
1937 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1938 	if (!err) {
1939 		nn->nb = nb;
1940 		list_add(&nn->list, &dev->net_notifier_list);
1941 	}
1942 	rtnl_unlock();
1943 	return err;
1944 }
1945 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1946 
1947 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1948 					  struct notifier_block *nb,
1949 					  struct netdev_net_notifier *nn)
1950 {
1951 	int err;
1952 
1953 	rtnl_lock();
1954 	list_del(&nn->list);
1955 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1956 	rtnl_unlock();
1957 	return err;
1958 }
1959 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1960 
1961 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1962 					     struct net *net)
1963 {
1964 	struct netdev_net_notifier *nn;
1965 
1966 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1967 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1968 }
1969 
1970 /**
1971  *	call_netdevice_notifiers_info - call all network notifier blocks
1972  *	@val: value passed unmodified to notifier function
1973  *	@info: notifier information data
1974  *
1975  *	Call all network notifier blocks.  Parameters and return value
1976  *	are as for raw_notifier_call_chain().
1977  */
1978 
1979 int call_netdevice_notifiers_info(unsigned long val,
1980 				  struct netdev_notifier_info *info)
1981 {
1982 	struct net *net = dev_net(info->dev);
1983 	int ret;
1984 
1985 	ASSERT_RTNL();
1986 
1987 	/* Run per-netns notifier block chain first, then run the global one.
1988 	 * Hopefully, one day, the global one is going to be removed after
1989 	 * all notifier block registrators get converted to be per-netns.
1990 	 */
1991 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1992 	if (ret & NOTIFY_STOP_MASK)
1993 		return ret;
1994 	return raw_notifier_call_chain(&netdev_chain, val, info);
1995 }
1996 
1997 /**
1998  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1999  *	                                       for and rollback on error
2000  *	@val_up: value passed unmodified to notifier function
2001  *	@val_down: value passed unmodified to the notifier function when
2002  *	           recovering from an error on @val_up
2003  *	@info: notifier information data
2004  *
2005  *	Call all per-netns network notifier blocks, but not notifier blocks on
2006  *	the global notifier chain. Parameters and return value are as for
2007  *	raw_notifier_call_chain_robust().
2008  */
2009 
2010 static int
2011 call_netdevice_notifiers_info_robust(unsigned long val_up,
2012 				     unsigned long val_down,
2013 				     struct netdev_notifier_info *info)
2014 {
2015 	struct net *net = dev_net(info->dev);
2016 
2017 	ASSERT_RTNL();
2018 
2019 	return raw_notifier_call_chain_robust(&net->netdev_chain,
2020 					      val_up, val_down, info);
2021 }
2022 
2023 static int call_netdevice_notifiers_extack(unsigned long val,
2024 					   struct net_device *dev,
2025 					   struct netlink_ext_ack *extack)
2026 {
2027 	struct netdev_notifier_info info = {
2028 		.dev = dev,
2029 		.extack = extack,
2030 	};
2031 
2032 	return call_netdevice_notifiers_info(val, &info);
2033 }
2034 
2035 /**
2036  *	call_netdevice_notifiers - call all network notifier blocks
2037  *      @val: value passed unmodified to notifier function
2038  *      @dev: net_device pointer passed unmodified to notifier function
2039  *
2040  *	Call all network notifier blocks.  Parameters and return value
2041  *	are as for raw_notifier_call_chain().
2042  */
2043 
2044 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
2045 {
2046 	return call_netdevice_notifiers_extack(val, dev, NULL);
2047 }
2048 EXPORT_SYMBOL(call_netdevice_notifiers);
2049 
2050 /**
2051  *	call_netdevice_notifiers_mtu - call all network notifier blocks
2052  *	@val: value passed unmodified to notifier function
2053  *	@dev: net_device pointer passed unmodified to notifier function
2054  *	@arg: additional u32 argument passed to the notifier function
2055  *
2056  *	Call all network notifier blocks.  Parameters and return value
2057  *	are as for raw_notifier_call_chain().
2058  */
2059 static int call_netdevice_notifiers_mtu(unsigned long val,
2060 					struct net_device *dev, u32 arg)
2061 {
2062 	struct netdev_notifier_info_ext info = {
2063 		.info.dev = dev,
2064 		.ext.mtu = arg,
2065 	};
2066 
2067 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2068 
2069 	return call_netdevice_notifiers_info(val, &info.info);
2070 }
2071 
2072 #ifdef CONFIG_NET_INGRESS
2073 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2074 
2075 void net_inc_ingress_queue(void)
2076 {
2077 	static_branch_inc(&ingress_needed_key);
2078 }
2079 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2080 
2081 void net_dec_ingress_queue(void)
2082 {
2083 	static_branch_dec(&ingress_needed_key);
2084 }
2085 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2086 #endif
2087 
2088 #ifdef CONFIG_NET_EGRESS
2089 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2090 
2091 void net_inc_egress_queue(void)
2092 {
2093 	static_branch_inc(&egress_needed_key);
2094 }
2095 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2096 
2097 void net_dec_egress_queue(void)
2098 {
2099 	static_branch_dec(&egress_needed_key);
2100 }
2101 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2102 #endif
2103 
2104 #ifdef CONFIG_NET_CLS_ACT
2105 DEFINE_STATIC_KEY_FALSE(tcf_bypass_check_needed_key);
2106 EXPORT_SYMBOL(tcf_bypass_check_needed_key);
2107 #endif
2108 
2109 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2110 EXPORT_SYMBOL(netstamp_needed_key);
2111 #ifdef CONFIG_JUMP_LABEL
2112 static atomic_t netstamp_needed_deferred;
2113 static atomic_t netstamp_wanted;
2114 static void netstamp_clear(struct work_struct *work)
2115 {
2116 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2117 	int wanted;
2118 
2119 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2120 	if (wanted > 0)
2121 		static_branch_enable(&netstamp_needed_key);
2122 	else
2123 		static_branch_disable(&netstamp_needed_key);
2124 }
2125 static DECLARE_WORK(netstamp_work, netstamp_clear);
2126 #endif
2127 
2128 void net_enable_timestamp(void)
2129 {
2130 #ifdef CONFIG_JUMP_LABEL
2131 	int wanted = atomic_read(&netstamp_wanted);
2132 
2133 	while (wanted > 0) {
2134 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2135 			return;
2136 	}
2137 	atomic_inc(&netstamp_needed_deferred);
2138 	schedule_work(&netstamp_work);
2139 #else
2140 	static_branch_inc(&netstamp_needed_key);
2141 #endif
2142 }
2143 EXPORT_SYMBOL(net_enable_timestamp);
2144 
2145 void net_disable_timestamp(void)
2146 {
2147 #ifdef CONFIG_JUMP_LABEL
2148 	int wanted = atomic_read(&netstamp_wanted);
2149 
2150 	while (wanted > 1) {
2151 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2152 			return;
2153 	}
2154 	atomic_dec(&netstamp_needed_deferred);
2155 	schedule_work(&netstamp_work);
2156 #else
2157 	static_branch_dec(&netstamp_needed_key);
2158 #endif
2159 }
2160 EXPORT_SYMBOL(net_disable_timestamp);
2161 
2162 static inline void net_timestamp_set(struct sk_buff *skb)
2163 {
2164 	skb->tstamp = 0;
2165 	skb->tstamp_type = SKB_CLOCK_REALTIME;
2166 	if (static_branch_unlikely(&netstamp_needed_key))
2167 		skb->tstamp = ktime_get_real();
2168 }
2169 
2170 #define net_timestamp_check(COND, SKB)				\
2171 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2172 		if ((COND) && !(SKB)->tstamp)			\
2173 			(SKB)->tstamp = ktime_get_real();	\
2174 	}							\
2175 
2176 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2177 {
2178 	return __is_skb_forwardable(dev, skb, true);
2179 }
2180 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2181 
2182 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2183 			      bool check_mtu)
2184 {
2185 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2186 
2187 	if (likely(!ret)) {
2188 		skb->protocol = eth_type_trans(skb, dev);
2189 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2190 	}
2191 
2192 	return ret;
2193 }
2194 
2195 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2196 {
2197 	return __dev_forward_skb2(dev, skb, true);
2198 }
2199 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2200 
2201 /**
2202  * dev_forward_skb - loopback an skb to another netif
2203  *
2204  * @dev: destination network device
2205  * @skb: buffer to forward
2206  *
2207  * return values:
2208  *	NET_RX_SUCCESS	(no congestion)
2209  *	NET_RX_DROP     (packet was dropped, but freed)
2210  *
2211  * dev_forward_skb can be used for injecting an skb from the
2212  * start_xmit function of one device into the receive queue
2213  * of another device.
2214  *
2215  * The receiving device may be in another namespace, so
2216  * we have to clear all information in the skb that could
2217  * impact namespace isolation.
2218  */
2219 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2220 {
2221 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2222 }
2223 EXPORT_SYMBOL_GPL(dev_forward_skb);
2224 
2225 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2226 {
2227 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2228 }
2229 
2230 static inline int deliver_skb(struct sk_buff *skb,
2231 			      struct packet_type *pt_prev,
2232 			      struct net_device *orig_dev)
2233 {
2234 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2235 		return -ENOMEM;
2236 	refcount_inc(&skb->users);
2237 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2238 }
2239 
2240 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2241 					  struct packet_type **pt,
2242 					  struct net_device *orig_dev,
2243 					  __be16 type,
2244 					  struct list_head *ptype_list)
2245 {
2246 	struct packet_type *ptype, *pt_prev = *pt;
2247 
2248 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2249 		if (ptype->type != type)
2250 			continue;
2251 		if (pt_prev)
2252 			deliver_skb(skb, pt_prev, orig_dev);
2253 		pt_prev = ptype;
2254 	}
2255 	*pt = pt_prev;
2256 }
2257 
2258 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2259 {
2260 	if (!ptype->af_packet_priv || !skb->sk)
2261 		return false;
2262 
2263 	if (ptype->id_match)
2264 		return ptype->id_match(ptype, skb->sk);
2265 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2266 		return true;
2267 
2268 	return false;
2269 }
2270 
2271 /**
2272  * dev_nit_active - return true if any network interface taps are in use
2273  *
2274  * @dev: network device to check for the presence of taps
2275  */
2276 bool dev_nit_active(struct net_device *dev)
2277 {
2278 	return !list_empty(&net_hotdata.ptype_all) ||
2279 	       !list_empty(&dev->ptype_all);
2280 }
2281 EXPORT_SYMBOL_GPL(dev_nit_active);
2282 
2283 /*
2284  *	Support routine. Sends outgoing frames to any network
2285  *	taps currently in use.
2286  */
2287 
2288 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2289 {
2290 	struct list_head *ptype_list = &net_hotdata.ptype_all;
2291 	struct packet_type *ptype, *pt_prev = NULL;
2292 	struct sk_buff *skb2 = NULL;
2293 
2294 	rcu_read_lock();
2295 again:
2296 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2297 		if (READ_ONCE(ptype->ignore_outgoing))
2298 			continue;
2299 
2300 		/* Never send packets back to the socket
2301 		 * they originated from - MvS (miquels@drinkel.ow.org)
2302 		 */
2303 		if (skb_loop_sk(ptype, skb))
2304 			continue;
2305 
2306 		if (pt_prev) {
2307 			deliver_skb(skb2, pt_prev, skb->dev);
2308 			pt_prev = ptype;
2309 			continue;
2310 		}
2311 
2312 		/* need to clone skb, done only once */
2313 		skb2 = skb_clone(skb, GFP_ATOMIC);
2314 		if (!skb2)
2315 			goto out_unlock;
2316 
2317 		net_timestamp_set(skb2);
2318 
2319 		/* skb->nh should be correctly
2320 		 * set by sender, so that the second statement is
2321 		 * just protection against buggy protocols.
2322 		 */
2323 		skb_reset_mac_header(skb2);
2324 
2325 		if (skb_network_header(skb2) < skb2->data ||
2326 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2327 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2328 					     ntohs(skb2->protocol),
2329 					     dev->name);
2330 			skb_reset_network_header(skb2);
2331 		}
2332 
2333 		skb2->transport_header = skb2->network_header;
2334 		skb2->pkt_type = PACKET_OUTGOING;
2335 		pt_prev = ptype;
2336 	}
2337 
2338 	if (ptype_list == &net_hotdata.ptype_all) {
2339 		ptype_list = &dev->ptype_all;
2340 		goto again;
2341 	}
2342 out_unlock:
2343 	if (pt_prev) {
2344 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2345 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2346 		else
2347 			kfree_skb(skb2);
2348 	}
2349 	rcu_read_unlock();
2350 }
2351 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2352 
2353 /**
2354  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2355  * @dev: Network device
2356  * @txq: number of queues available
2357  *
2358  * If real_num_tx_queues is changed the tc mappings may no longer be
2359  * valid. To resolve this verify the tc mapping remains valid and if
2360  * not NULL the mapping. With no priorities mapping to this
2361  * offset/count pair it will no longer be used. In the worst case TC0
2362  * is invalid nothing can be done so disable priority mappings. If is
2363  * expected that drivers will fix this mapping if they can before
2364  * calling netif_set_real_num_tx_queues.
2365  */
2366 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2367 {
2368 	int i;
2369 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2370 
2371 	/* If TC0 is invalidated disable TC mapping */
2372 	if (tc->offset + tc->count > txq) {
2373 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2374 		dev->num_tc = 0;
2375 		return;
2376 	}
2377 
2378 	/* Invalidated prio to tc mappings set to TC0 */
2379 	for (i = 1; i < TC_BITMASK + 1; i++) {
2380 		int q = netdev_get_prio_tc_map(dev, i);
2381 
2382 		tc = &dev->tc_to_txq[q];
2383 		if (tc->offset + tc->count > txq) {
2384 			netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2385 				    i, q);
2386 			netdev_set_prio_tc_map(dev, i, 0);
2387 		}
2388 	}
2389 }
2390 
2391 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2392 {
2393 	if (dev->num_tc) {
2394 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2395 		int i;
2396 
2397 		/* walk through the TCs and see if it falls into any of them */
2398 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2399 			if ((txq - tc->offset) < tc->count)
2400 				return i;
2401 		}
2402 
2403 		/* didn't find it, just return -1 to indicate no match */
2404 		return -1;
2405 	}
2406 
2407 	return 0;
2408 }
2409 EXPORT_SYMBOL(netdev_txq_to_tc);
2410 
2411 #ifdef CONFIG_XPS
2412 static struct static_key xps_needed __read_mostly;
2413 static struct static_key xps_rxqs_needed __read_mostly;
2414 static DEFINE_MUTEX(xps_map_mutex);
2415 #define xmap_dereference(P)		\
2416 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2417 
2418 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2419 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2420 {
2421 	struct xps_map *map = NULL;
2422 	int pos;
2423 
2424 	map = xmap_dereference(dev_maps->attr_map[tci]);
2425 	if (!map)
2426 		return false;
2427 
2428 	for (pos = map->len; pos--;) {
2429 		if (map->queues[pos] != index)
2430 			continue;
2431 
2432 		if (map->len > 1) {
2433 			map->queues[pos] = map->queues[--map->len];
2434 			break;
2435 		}
2436 
2437 		if (old_maps)
2438 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2439 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2440 		kfree_rcu(map, rcu);
2441 		return false;
2442 	}
2443 
2444 	return true;
2445 }
2446 
2447 static bool remove_xps_queue_cpu(struct net_device *dev,
2448 				 struct xps_dev_maps *dev_maps,
2449 				 int cpu, u16 offset, u16 count)
2450 {
2451 	int num_tc = dev_maps->num_tc;
2452 	bool active = false;
2453 	int tci;
2454 
2455 	for (tci = cpu * num_tc; num_tc--; tci++) {
2456 		int i, j;
2457 
2458 		for (i = count, j = offset; i--; j++) {
2459 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2460 				break;
2461 		}
2462 
2463 		active |= i < 0;
2464 	}
2465 
2466 	return active;
2467 }
2468 
2469 static void reset_xps_maps(struct net_device *dev,
2470 			   struct xps_dev_maps *dev_maps,
2471 			   enum xps_map_type type)
2472 {
2473 	static_key_slow_dec_cpuslocked(&xps_needed);
2474 	if (type == XPS_RXQS)
2475 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2476 
2477 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2478 
2479 	kfree_rcu(dev_maps, rcu);
2480 }
2481 
2482 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2483 			   u16 offset, u16 count)
2484 {
2485 	struct xps_dev_maps *dev_maps;
2486 	bool active = false;
2487 	int i, j;
2488 
2489 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2490 	if (!dev_maps)
2491 		return;
2492 
2493 	for (j = 0; j < dev_maps->nr_ids; j++)
2494 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2495 	if (!active)
2496 		reset_xps_maps(dev, dev_maps, type);
2497 
2498 	if (type == XPS_CPUS) {
2499 		for (i = offset + (count - 1); count--; i--)
2500 			netdev_queue_numa_node_write(
2501 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2502 	}
2503 }
2504 
2505 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2506 				   u16 count)
2507 {
2508 	if (!static_key_false(&xps_needed))
2509 		return;
2510 
2511 	cpus_read_lock();
2512 	mutex_lock(&xps_map_mutex);
2513 
2514 	if (static_key_false(&xps_rxqs_needed))
2515 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2516 
2517 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2518 
2519 	mutex_unlock(&xps_map_mutex);
2520 	cpus_read_unlock();
2521 }
2522 
2523 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2524 {
2525 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2526 }
2527 
2528 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2529 				      u16 index, bool is_rxqs_map)
2530 {
2531 	struct xps_map *new_map;
2532 	int alloc_len = XPS_MIN_MAP_ALLOC;
2533 	int i, pos;
2534 
2535 	for (pos = 0; map && pos < map->len; pos++) {
2536 		if (map->queues[pos] != index)
2537 			continue;
2538 		return map;
2539 	}
2540 
2541 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2542 	if (map) {
2543 		if (pos < map->alloc_len)
2544 			return map;
2545 
2546 		alloc_len = map->alloc_len * 2;
2547 	}
2548 
2549 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2550 	 *  map
2551 	 */
2552 	if (is_rxqs_map)
2553 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2554 	else
2555 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2556 				       cpu_to_node(attr_index));
2557 	if (!new_map)
2558 		return NULL;
2559 
2560 	for (i = 0; i < pos; i++)
2561 		new_map->queues[i] = map->queues[i];
2562 	new_map->alloc_len = alloc_len;
2563 	new_map->len = pos;
2564 
2565 	return new_map;
2566 }
2567 
2568 /* Copy xps maps at a given index */
2569 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2570 			      struct xps_dev_maps *new_dev_maps, int index,
2571 			      int tc, bool skip_tc)
2572 {
2573 	int i, tci = index * dev_maps->num_tc;
2574 	struct xps_map *map;
2575 
2576 	/* copy maps belonging to foreign traffic classes */
2577 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2578 		if (i == tc && skip_tc)
2579 			continue;
2580 
2581 		/* fill in the new device map from the old device map */
2582 		map = xmap_dereference(dev_maps->attr_map[tci]);
2583 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2584 	}
2585 }
2586 
2587 /* Must be called under cpus_read_lock */
2588 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2589 			  u16 index, enum xps_map_type type)
2590 {
2591 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2592 	const unsigned long *online_mask = NULL;
2593 	bool active = false, copy = false;
2594 	int i, j, tci, numa_node_id = -2;
2595 	int maps_sz, num_tc = 1, tc = 0;
2596 	struct xps_map *map, *new_map;
2597 	unsigned int nr_ids;
2598 
2599 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2600 
2601 	if (dev->num_tc) {
2602 		/* Do not allow XPS on subordinate device directly */
2603 		num_tc = dev->num_tc;
2604 		if (num_tc < 0)
2605 			return -EINVAL;
2606 
2607 		/* If queue belongs to subordinate dev use its map */
2608 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2609 
2610 		tc = netdev_txq_to_tc(dev, index);
2611 		if (tc < 0)
2612 			return -EINVAL;
2613 	}
2614 
2615 	mutex_lock(&xps_map_mutex);
2616 
2617 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2618 	if (type == XPS_RXQS) {
2619 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2620 		nr_ids = dev->num_rx_queues;
2621 	} else {
2622 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2623 		if (num_possible_cpus() > 1)
2624 			online_mask = cpumask_bits(cpu_online_mask);
2625 		nr_ids = nr_cpu_ids;
2626 	}
2627 
2628 	if (maps_sz < L1_CACHE_BYTES)
2629 		maps_sz = L1_CACHE_BYTES;
2630 
2631 	/* The old dev_maps could be larger or smaller than the one we're
2632 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2633 	 * between. We could try to be smart, but let's be safe instead and only
2634 	 * copy foreign traffic classes if the two map sizes match.
2635 	 */
2636 	if (dev_maps &&
2637 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2638 		copy = true;
2639 
2640 	/* allocate memory for queue storage */
2641 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2642 	     j < nr_ids;) {
2643 		if (!new_dev_maps) {
2644 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2645 			if (!new_dev_maps) {
2646 				mutex_unlock(&xps_map_mutex);
2647 				return -ENOMEM;
2648 			}
2649 
2650 			new_dev_maps->nr_ids = nr_ids;
2651 			new_dev_maps->num_tc = num_tc;
2652 		}
2653 
2654 		tci = j * num_tc + tc;
2655 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2656 
2657 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2658 		if (!map)
2659 			goto error;
2660 
2661 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2662 	}
2663 
2664 	if (!new_dev_maps)
2665 		goto out_no_new_maps;
2666 
2667 	if (!dev_maps) {
2668 		/* Increment static keys at most once per type */
2669 		static_key_slow_inc_cpuslocked(&xps_needed);
2670 		if (type == XPS_RXQS)
2671 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2672 	}
2673 
2674 	for (j = 0; j < nr_ids; j++) {
2675 		bool skip_tc = false;
2676 
2677 		tci = j * num_tc + tc;
2678 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2679 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2680 			/* add tx-queue to CPU/rx-queue maps */
2681 			int pos = 0;
2682 
2683 			skip_tc = true;
2684 
2685 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2686 			while ((pos < map->len) && (map->queues[pos] != index))
2687 				pos++;
2688 
2689 			if (pos == map->len)
2690 				map->queues[map->len++] = index;
2691 #ifdef CONFIG_NUMA
2692 			if (type == XPS_CPUS) {
2693 				if (numa_node_id == -2)
2694 					numa_node_id = cpu_to_node(j);
2695 				else if (numa_node_id != cpu_to_node(j))
2696 					numa_node_id = -1;
2697 			}
2698 #endif
2699 		}
2700 
2701 		if (copy)
2702 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2703 					  skip_tc);
2704 	}
2705 
2706 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2707 
2708 	/* Cleanup old maps */
2709 	if (!dev_maps)
2710 		goto out_no_old_maps;
2711 
2712 	for (j = 0; j < dev_maps->nr_ids; j++) {
2713 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2714 			map = xmap_dereference(dev_maps->attr_map[tci]);
2715 			if (!map)
2716 				continue;
2717 
2718 			if (copy) {
2719 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2720 				if (map == new_map)
2721 					continue;
2722 			}
2723 
2724 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2725 			kfree_rcu(map, rcu);
2726 		}
2727 	}
2728 
2729 	old_dev_maps = dev_maps;
2730 
2731 out_no_old_maps:
2732 	dev_maps = new_dev_maps;
2733 	active = true;
2734 
2735 out_no_new_maps:
2736 	if (type == XPS_CPUS)
2737 		/* update Tx queue numa node */
2738 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2739 					     (numa_node_id >= 0) ?
2740 					     numa_node_id : NUMA_NO_NODE);
2741 
2742 	if (!dev_maps)
2743 		goto out_no_maps;
2744 
2745 	/* removes tx-queue from unused CPUs/rx-queues */
2746 	for (j = 0; j < dev_maps->nr_ids; j++) {
2747 		tci = j * dev_maps->num_tc;
2748 
2749 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2750 			if (i == tc &&
2751 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2752 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2753 				continue;
2754 
2755 			active |= remove_xps_queue(dev_maps,
2756 						   copy ? old_dev_maps : NULL,
2757 						   tci, index);
2758 		}
2759 	}
2760 
2761 	if (old_dev_maps)
2762 		kfree_rcu(old_dev_maps, rcu);
2763 
2764 	/* free map if not active */
2765 	if (!active)
2766 		reset_xps_maps(dev, dev_maps, type);
2767 
2768 out_no_maps:
2769 	mutex_unlock(&xps_map_mutex);
2770 
2771 	return 0;
2772 error:
2773 	/* remove any maps that we added */
2774 	for (j = 0; j < nr_ids; j++) {
2775 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2776 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2777 			map = copy ?
2778 			      xmap_dereference(dev_maps->attr_map[tci]) :
2779 			      NULL;
2780 			if (new_map && new_map != map)
2781 				kfree(new_map);
2782 		}
2783 	}
2784 
2785 	mutex_unlock(&xps_map_mutex);
2786 
2787 	kfree(new_dev_maps);
2788 	return -ENOMEM;
2789 }
2790 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2791 
2792 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2793 			u16 index)
2794 {
2795 	int ret;
2796 
2797 	cpus_read_lock();
2798 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2799 	cpus_read_unlock();
2800 
2801 	return ret;
2802 }
2803 EXPORT_SYMBOL(netif_set_xps_queue);
2804 
2805 #endif
2806 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2807 {
2808 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2809 
2810 	/* Unbind any subordinate channels */
2811 	while (txq-- != &dev->_tx[0]) {
2812 		if (txq->sb_dev)
2813 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2814 	}
2815 }
2816 
2817 void netdev_reset_tc(struct net_device *dev)
2818 {
2819 #ifdef CONFIG_XPS
2820 	netif_reset_xps_queues_gt(dev, 0);
2821 #endif
2822 	netdev_unbind_all_sb_channels(dev);
2823 
2824 	/* Reset TC configuration of device */
2825 	dev->num_tc = 0;
2826 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2827 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2828 }
2829 EXPORT_SYMBOL(netdev_reset_tc);
2830 
2831 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2832 {
2833 	if (tc >= dev->num_tc)
2834 		return -EINVAL;
2835 
2836 #ifdef CONFIG_XPS
2837 	netif_reset_xps_queues(dev, offset, count);
2838 #endif
2839 	dev->tc_to_txq[tc].count = count;
2840 	dev->tc_to_txq[tc].offset = offset;
2841 	return 0;
2842 }
2843 EXPORT_SYMBOL(netdev_set_tc_queue);
2844 
2845 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2846 {
2847 	if (num_tc > TC_MAX_QUEUE)
2848 		return -EINVAL;
2849 
2850 #ifdef CONFIG_XPS
2851 	netif_reset_xps_queues_gt(dev, 0);
2852 #endif
2853 	netdev_unbind_all_sb_channels(dev);
2854 
2855 	dev->num_tc = num_tc;
2856 	return 0;
2857 }
2858 EXPORT_SYMBOL(netdev_set_num_tc);
2859 
2860 void netdev_unbind_sb_channel(struct net_device *dev,
2861 			      struct net_device *sb_dev)
2862 {
2863 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2864 
2865 #ifdef CONFIG_XPS
2866 	netif_reset_xps_queues_gt(sb_dev, 0);
2867 #endif
2868 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2869 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2870 
2871 	while (txq-- != &dev->_tx[0]) {
2872 		if (txq->sb_dev == sb_dev)
2873 			txq->sb_dev = NULL;
2874 	}
2875 }
2876 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2877 
2878 int netdev_bind_sb_channel_queue(struct net_device *dev,
2879 				 struct net_device *sb_dev,
2880 				 u8 tc, u16 count, u16 offset)
2881 {
2882 	/* Make certain the sb_dev and dev are already configured */
2883 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2884 		return -EINVAL;
2885 
2886 	/* We cannot hand out queues we don't have */
2887 	if ((offset + count) > dev->real_num_tx_queues)
2888 		return -EINVAL;
2889 
2890 	/* Record the mapping */
2891 	sb_dev->tc_to_txq[tc].count = count;
2892 	sb_dev->tc_to_txq[tc].offset = offset;
2893 
2894 	/* Provide a way for Tx queue to find the tc_to_txq map or
2895 	 * XPS map for itself.
2896 	 */
2897 	while (count--)
2898 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2899 
2900 	return 0;
2901 }
2902 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2903 
2904 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2905 {
2906 	/* Do not use a multiqueue device to represent a subordinate channel */
2907 	if (netif_is_multiqueue(dev))
2908 		return -ENODEV;
2909 
2910 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2911 	 * Channel 0 is meant to be "native" mode and used only to represent
2912 	 * the main root device. We allow writing 0 to reset the device back
2913 	 * to normal mode after being used as a subordinate channel.
2914 	 */
2915 	if (channel > S16_MAX)
2916 		return -EINVAL;
2917 
2918 	dev->num_tc = -channel;
2919 
2920 	return 0;
2921 }
2922 EXPORT_SYMBOL(netdev_set_sb_channel);
2923 
2924 /*
2925  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2926  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2927  */
2928 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2929 {
2930 	bool disabling;
2931 	int rc;
2932 
2933 	disabling = txq < dev->real_num_tx_queues;
2934 
2935 	if (txq < 1 || txq > dev->num_tx_queues)
2936 		return -EINVAL;
2937 
2938 	if (dev->reg_state == NETREG_REGISTERED ||
2939 	    dev->reg_state == NETREG_UNREGISTERING) {
2940 		ASSERT_RTNL();
2941 
2942 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2943 						  txq);
2944 		if (rc)
2945 			return rc;
2946 
2947 		if (dev->num_tc)
2948 			netif_setup_tc(dev, txq);
2949 
2950 		dev_qdisc_change_real_num_tx(dev, txq);
2951 
2952 		dev->real_num_tx_queues = txq;
2953 
2954 		if (disabling) {
2955 			synchronize_net();
2956 			qdisc_reset_all_tx_gt(dev, txq);
2957 #ifdef CONFIG_XPS
2958 			netif_reset_xps_queues_gt(dev, txq);
2959 #endif
2960 		}
2961 	} else {
2962 		dev->real_num_tx_queues = txq;
2963 	}
2964 
2965 	return 0;
2966 }
2967 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2968 
2969 #ifdef CONFIG_SYSFS
2970 /**
2971  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2972  *	@dev: Network device
2973  *	@rxq: Actual number of RX queues
2974  *
2975  *	This must be called either with the rtnl_lock held or before
2976  *	registration of the net device.  Returns 0 on success, or a
2977  *	negative error code.  If called before registration, it always
2978  *	succeeds.
2979  */
2980 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2981 {
2982 	int rc;
2983 
2984 	if (rxq < 1 || rxq > dev->num_rx_queues)
2985 		return -EINVAL;
2986 
2987 	if (dev->reg_state == NETREG_REGISTERED) {
2988 		ASSERT_RTNL();
2989 
2990 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2991 						  rxq);
2992 		if (rc)
2993 			return rc;
2994 	}
2995 
2996 	dev->real_num_rx_queues = rxq;
2997 	return 0;
2998 }
2999 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
3000 #endif
3001 
3002 /**
3003  *	netif_set_real_num_queues - set actual number of RX and TX queues used
3004  *	@dev: Network device
3005  *	@txq: Actual number of TX queues
3006  *	@rxq: Actual number of RX queues
3007  *
3008  *	Set the real number of both TX and RX queues.
3009  *	Does nothing if the number of queues is already correct.
3010  */
3011 int netif_set_real_num_queues(struct net_device *dev,
3012 			      unsigned int txq, unsigned int rxq)
3013 {
3014 	unsigned int old_rxq = dev->real_num_rx_queues;
3015 	int err;
3016 
3017 	if (txq < 1 || txq > dev->num_tx_queues ||
3018 	    rxq < 1 || rxq > dev->num_rx_queues)
3019 		return -EINVAL;
3020 
3021 	/* Start from increases, so the error path only does decreases -
3022 	 * decreases can't fail.
3023 	 */
3024 	if (rxq > dev->real_num_rx_queues) {
3025 		err = netif_set_real_num_rx_queues(dev, rxq);
3026 		if (err)
3027 			return err;
3028 	}
3029 	if (txq > dev->real_num_tx_queues) {
3030 		err = netif_set_real_num_tx_queues(dev, txq);
3031 		if (err)
3032 			goto undo_rx;
3033 	}
3034 	if (rxq < dev->real_num_rx_queues)
3035 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
3036 	if (txq < dev->real_num_tx_queues)
3037 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
3038 
3039 	return 0;
3040 undo_rx:
3041 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
3042 	return err;
3043 }
3044 EXPORT_SYMBOL(netif_set_real_num_queues);
3045 
3046 /**
3047  * netif_set_tso_max_size() - set the max size of TSO frames supported
3048  * @dev:	netdev to update
3049  * @size:	max skb->len of a TSO frame
3050  *
3051  * Set the limit on the size of TSO super-frames the device can handle.
3052  * Unless explicitly set the stack will assume the value of
3053  * %GSO_LEGACY_MAX_SIZE.
3054  */
3055 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3056 {
3057 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
3058 	if (size < READ_ONCE(dev->gso_max_size))
3059 		netif_set_gso_max_size(dev, size);
3060 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
3061 		netif_set_gso_ipv4_max_size(dev, size);
3062 }
3063 EXPORT_SYMBOL(netif_set_tso_max_size);
3064 
3065 /**
3066  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3067  * @dev:	netdev to update
3068  * @segs:	max number of TCP segments
3069  *
3070  * Set the limit on the number of TCP segments the device can generate from
3071  * a single TSO super-frame.
3072  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3073  */
3074 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3075 {
3076 	dev->tso_max_segs = segs;
3077 	if (segs < READ_ONCE(dev->gso_max_segs))
3078 		netif_set_gso_max_segs(dev, segs);
3079 }
3080 EXPORT_SYMBOL(netif_set_tso_max_segs);
3081 
3082 /**
3083  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3084  * @to:		netdev to update
3085  * @from:	netdev from which to copy the limits
3086  */
3087 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3088 {
3089 	netif_set_tso_max_size(to, from->tso_max_size);
3090 	netif_set_tso_max_segs(to, from->tso_max_segs);
3091 }
3092 EXPORT_SYMBOL(netif_inherit_tso_max);
3093 
3094 /**
3095  * netif_get_num_default_rss_queues - default number of RSS queues
3096  *
3097  * Default value is the number of physical cores if there are only 1 or 2, or
3098  * divided by 2 if there are more.
3099  */
3100 int netif_get_num_default_rss_queues(void)
3101 {
3102 	cpumask_var_t cpus;
3103 	int cpu, count = 0;
3104 
3105 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3106 		return 1;
3107 
3108 	cpumask_copy(cpus, cpu_online_mask);
3109 	for_each_cpu(cpu, cpus) {
3110 		++count;
3111 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3112 	}
3113 	free_cpumask_var(cpus);
3114 
3115 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3116 }
3117 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3118 
3119 static void __netif_reschedule(struct Qdisc *q)
3120 {
3121 	struct softnet_data *sd;
3122 	unsigned long flags;
3123 
3124 	local_irq_save(flags);
3125 	sd = this_cpu_ptr(&softnet_data);
3126 	q->next_sched = NULL;
3127 	*sd->output_queue_tailp = q;
3128 	sd->output_queue_tailp = &q->next_sched;
3129 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3130 	local_irq_restore(flags);
3131 }
3132 
3133 void __netif_schedule(struct Qdisc *q)
3134 {
3135 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3136 		__netif_reschedule(q);
3137 }
3138 EXPORT_SYMBOL(__netif_schedule);
3139 
3140 struct dev_kfree_skb_cb {
3141 	enum skb_drop_reason reason;
3142 };
3143 
3144 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3145 {
3146 	return (struct dev_kfree_skb_cb *)skb->cb;
3147 }
3148 
3149 void netif_schedule_queue(struct netdev_queue *txq)
3150 {
3151 	rcu_read_lock();
3152 	if (!netif_xmit_stopped(txq)) {
3153 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3154 
3155 		__netif_schedule(q);
3156 	}
3157 	rcu_read_unlock();
3158 }
3159 EXPORT_SYMBOL(netif_schedule_queue);
3160 
3161 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3162 {
3163 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3164 		struct Qdisc *q;
3165 
3166 		rcu_read_lock();
3167 		q = rcu_dereference(dev_queue->qdisc);
3168 		__netif_schedule(q);
3169 		rcu_read_unlock();
3170 	}
3171 }
3172 EXPORT_SYMBOL(netif_tx_wake_queue);
3173 
3174 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3175 {
3176 	unsigned long flags;
3177 
3178 	if (unlikely(!skb))
3179 		return;
3180 
3181 	if (likely(refcount_read(&skb->users) == 1)) {
3182 		smp_rmb();
3183 		refcount_set(&skb->users, 0);
3184 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3185 		return;
3186 	}
3187 	get_kfree_skb_cb(skb)->reason = reason;
3188 	local_irq_save(flags);
3189 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3190 	__this_cpu_write(softnet_data.completion_queue, skb);
3191 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3192 	local_irq_restore(flags);
3193 }
3194 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3195 
3196 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3197 {
3198 	if (in_hardirq() || irqs_disabled())
3199 		dev_kfree_skb_irq_reason(skb, reason);
3200 	else
3201 		kfree_skb_reason(skb, reason);
3202 }
3203 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3204 
3205 
3206 /**
3207  * netif_device_detach - mark device as removed
3208  * @dev: network device
3209  *
3210  * Mark device as removed from system and therefore no longer available.
3211  */
3212 void netif_device_detach(struct net_device *dev)
3213 {
3214 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3215 	    netif_running(dev)) {
3216 		netif_tx_stop_all_queues(dev);
3217 	}
3218 }
3219 EXPORT_SYMBOL(netif_device_detach);
3220 
3221 /**
3222  * netif_device_attach - mark device as attached
3223  * @dev: network device
3224  *
3225  * Mark device as attached from system and restart if needed.
3226  */
3227 void netif_device_attach(struct net_device *dev)
3228 {
3229 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3230 	    netif_running(dev)) {
3231 		netif_tx_wake_all_queues(dev);
3232 		__netdev_watchdog_up(dev);
3233 	}
3234 }
3235 EXPORT_SYMBOL(netif_device_attach);
3236 
3237 /*
3238  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3239  * to be used as a distribution range.
3240  */
3241 static u16 skb_tx_hash(const struct net_device *dev,
3242 		       const struct net_device *sb_dev,
3243 		       struct sk_buff *skb)
3244 {
3245 	u32 hash;
3246 	u16 qoffset = 0;
3247 	u16 qcount = dev->real_num_tx_queues;
3248 
3249 	if (dev->num_tc) {
3250 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3251 
3252 		qoffset = sb_dev->tc_to_txq[tc].offset;
3253 		qcount = sb_dev->tc_to_txq[tc].count;
3254 		if (unlikely(!qcount)) {
3255 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3256 					     sb_dev->name, qoffset, tc);
3257 			qoffset = 0;
3258 			qcount = dev->real_num_tx_queues;
3259 		}
3260 	}
3261 
3262 	if (skb_rx_queue_recorded(skb)) {
3263 		DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3264 		hash = skb_get_rx_queue(skb);
3265 		if (hash >= qoffset)
3266 			hash -= qoffset;
3267 		while (unlikely(hash >= qcount))
3268 			hash -= qcount;
3269 		return hash + qoffset;
3270 	}
3271 
3272 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3273 }
3274 
3275 void skb_warn_bad_offload(const struct sk_buff *skb)
3276 {
3277 	static const netdev_features_t null_features;
3278 	struct net_device *dev = skb->dev;
3279 	const char *name = "";
3280 
3281 	if (!net_ratelimit())
3282 		return;
3283 
3284 	if (dev) {
3285 		if (dev->dev.parent)
3286 			name = dev_driver_string(dev->dev.parent);
3287 		else
3288 			name = netdev_name(dev);
3289 	}
3290 	skb_dump(KERN_WARNING, skb, false);
3291 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3292 	     name, dev ? &dev->features : &null_features,
3293 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3294 }
3295 
3296 /*
3297  * Invalidate hardware checksum when packet is to be mangled, and
3298  * complete checksum manually on outgoing path.
3299  */
3300 int skb_checksum_help(struct sk_buff *skb)
3301 {
3302 	__wsum csum;
3303 	int ret = 0, offset;
3304 
3305 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3306 		goto out_set_summed;
3307 
3308 	if (unlikely(skb_is_gso(skb))) {
3309 		skb_warn_bad_offload(skb);
3310 		return -EINVAL;
3311 	}
3312 
3313 	/* Before computing a checksum, we should make sure no frag could
3314 	 * be modified by an external entity : checksum could be wrong.
3315 	 */
3316 	if (skb_has_shared_frag(skb)) {
3317 		ret = __skb_linearize(skb);
3318 		if (ret)
3319 			goto out;
3320 	}
3321 
3322 	offset = skb_checksum_start_offset(skb);
3323 	ret = -EINVAL;
3324 	if (unlikely(offset >= skb_headlen(skb))) {
3325 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3326 		WARN_ONCE(true, "offset (%d) >= skb_headlen() (%u)\n",
3327 			  offset, skb_headlen(skb));
3328 		goto out;
3329 	}
3330 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3331 
3332 	offset += skb->csum_offset;
3333 	if (unlikely(offset + sizeof(__sum16) > skb_headlen(skb))) {
3334 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3335 		WARN_ONCE(true, "offset+2 (%zu) > skb_headlen() (%u)\n",
3336 			  offset + sizeof(__sum16), skb_headlen(skb));
3337 		goto out;
3338 	}
3339 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3340 	if (ret)
3341 		goto out;
3342 
3343 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3344 out_set_summed:
3345 	skb->ip_summed = CHECKSUM_NONE;
3346 out:
3347 	return ret;
3348 }
3349 EXPORT_SYMBOL(skb_checksum_help);
3350 
3351 int skb_crc32c_csum_help(struct sk_buff *skb)
3352 {
3353 	__le32 crc32c_csum;
3354 	int ret = 0, offset, start;
3355 
3356 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3357 		goto out;
3358 
3359 	if (unlikely(skb_is_gso(skb)))
3360 		goto out;
3361 
3362 	/* Before computing a checksum, we should make sure no frag could
3363 	 * be modified by an external entity : checksum could be wrong.
3364 	 */
3365 	if (unlikely(skb_has_shared_frag(skb))) {
3366 		ret = __skb_linearize(skb);
3367 		if (ret)
3368 			goto out;
3369 	}
3370 	start = skb_checksum_start_offset(skb);
3371 	offset = start + offsetof(struct sctphdr, checksum);
3372 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3373 		ret = -EINVAL;
3374 		goto out;
3375 	}
3376 
3377 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3378 	if (ret)
3379 		goto out;
3380 
3381 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3382 						  skb->len - start, ~(__u32)0,
3383 						  crc32c_csum_stub));
3384 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3385 	skb_reset_csum_not_inet(skb);
3386 out:
3387 	return ret;
3388 }
3389 
3390 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3391 {
3392 	__be16 type = skb->protocol;
3393 
3394 	/* Tunnel gso handlers can set protocol to ethernet. */
3395 	if (type == htons(ETH_P_TEB)) {
3396 		struct ethhdr *eth;
3397 
3398 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3399 			return 0;
3400 
3401 		eth = (struct ethhdr *)skb->data;
3402 		type = eth->h_proto;
3403 	}
3404 
3405 	return vlan_get_protocol_and_depth(skb, type, depth);
3406 }
3407 
3408 
3409 /* Take action when hardware reception checksum errors are detected. */
3410 #ifdef CONFIG_BUG
3411 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3412 {
3413 	netdev_err(dev, "hw csum failure\n");
3414 	skb_dump(KERN_ERR, skb, true);
3415 	dump_stack();
3416 }
3417 
3418 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3419 {
3420 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3421 }
3422 EXPORT_SYMBOL(netdev_rx_csum_fault);
3423 #endif
3424 
3425 /* XXX: check that highmem exists at all on the given machine. */
3426 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3427 {
3428 #ifdef CONFIG_HIGHMEM
3429 	int i;
3430 
3431 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3432 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3433 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3434 
3435 			if (PageHighMem(skb_frag_page(frag)))
3436 				return 1;
3437 		}
3438 	}
3439 #endif
3440 	return 0;
3441 }
3442 
3443 /* If MPLS offload request, verify we are testing hardware MPLS features
3444  * instead of standard features for the netdev.
3445  */
3446 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3447 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3448 					   netdev_features_t features,
3449 					   __be16 type)
3450 {
3451 	if (eth_p_mpls(type))
3452 		features &= skb->dev->mpls_features;
3453 
3454 	return features;
3455 }
3456 #else
3457 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3458 					   netdev_features_t features,
3459 					   __be16 type)
3460 {
3461 	return features;
3462 }
3463 #endif
3464 
3465 static netdev_features_t harmonize_features(struct sk_buff *skb,
3466 	netdev_features_t features)
3467 {
3468 	__be16 type;
3469 
3470 	type = skb_network_protocol(skb, NULL);
3471 	features = net_mpls_features(skb, features, type);
3472 
3473 	if (skb->ip_summed != CHECKSUM_NONE &&
3474 	    !can_checksum_protocol(features, type)) {
3475 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3476 	}
3477 	if (illegal_highdma(skb->dev, skb))
3478 		features &= ~NETIF_F_SG;
3479 
3480 	return features;
3481 }
3482 
3483 netdev_features_t passthru_features_check(struct sk_buff *skb,
3484 					  struct net_device *dev,
3485 					  netdev_features_t features)
3486 {
3487 	return features;
3488 }
3489 EXPORT_SYMBOL(passthru_features_check);
3490 
3491 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3492 					     struct net_device *dev,
3493 					     netdev_features_t features)
3494 {
3495 	return vlan_features_check(skb, features);
3496 }
3497 
3498 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3499 					    struct net_device *dev,
3500 					    netdev_features_t features)
3501 {
3502 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3503 
3504 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3505 		return features & ~NETIF_F_GSO_MASK;
3506 
3507 	if (unlikely(skb->len >= READ_ONCE(dev->gso_max_size)))
3508 		return features & ~NETIF_F_GSO_MASK;
3509 
3510 	if (!skb_shinfo(skb)->gso_type) {
3511 		skb_warn_bad_offload(skb);
3512 		return features & ~NETIF_F_GSO_MASK;
3513 	}
3514 
3515 	/* Support for GSO partial features requires software
3516 	 * intervention before we can actually process the packets
3517 	 * so we need to strip support for any partial features now
3518 	 * and we can pull them back in after we have partially
3519 	 * segmented the frame.
3520 	 */
3521 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3522 		features &= ~dev->gso_partial_features;
3523 
3524 	/* Make sure to clear the IPv4 ID mangling feature if the
3525 	 * IPv4 header has the potential to be fragmented.
3526 	 */
3527 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3528 		struct iphdr *iph = skb->encapsulation ?
3529 				    inner_ip_hdr(skb) : ip_hdr(skb);
3530 
3531 		if (!(iph->frag_off & htons(IP_DF)))
3532 			features &= ~NETIF_F_TSO_MANGLEID;
3533 	}
3534 
3535 	return features;
3536 }
3537 
3538 netdev_features_t netif_skb_features(struct sk_buff *skb)
3539 {
3540 	struct net_device *dev = skb->dev;
3541 	netdev_features_t features = dev->features;
3542 
3543 	if (skb_is_gso(skb))
3544 		features = gso_features_check(skb, dev, features);
3545 
3546 	/* If encapsulation offload request, verify we are testing
3547 	 * hardware encapsulation features instead of standard
3548 	 * features for the netdev
3549 	 */
3550 	if (skb->encapsulation)
3551 		features &= dev->hw_enc_features;
3552 
3553 	if (skb_vlan_tagged(skb))
3554 		features = netdev_intersect_features(features,
3555 						     dev->vlan_features |
3556 						     NETIF_F_HW_VLAN_CTAG_TX |
3557 						     NETIF_F_HW_VLAN_STAG_TX);
3558 
3559 	if (dev->netdev_ops->ndo_features_check)
3560 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3561 								features);
3562 	else
3563 		features &= dflt_features_check(skb, dev, features);
3564 
3565 	return harmonize_features(skb, features);
3566 }
3567 EXPORT_SYMBOL(netif_skb_features);
3568 
3569 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3570 		    struct netdev_queue *txq, bool more)
3571 {
3572 	unsigned int len;
3573 	int rc;
3574 
3575 	if (dev_nit_active(dev))
3576 		dev_queue_xmit_nit(skb, dev);
3577 
3578 	len = skb->len;
3579 	trace_net_dev_start_xmit(skb, dev);
3580 	rc = netdev_start_xmit(skb, dev, txq, more);
3581 	trace_net_dev_xmit(skb, rc, dev, len);
3582 
3583 	return rc;
3584 }
3585 
3586 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3587 				    struct netdev_queue *txq, int *ret)
3588 {
3589 	struct sk_buff *skb = first;
3590 	int rc = NETDEV_TX_OK;
3591 
3592 	while (skb) {
3593 		struct sk_buff *next = skb->next;
3594 
3595 		skb_mark_not_on_list(skb);
3596 		rc = xmit_one(skb, dev, txq, next != NULL);
3597 		if (unlikely(!dev_xmit_complete(rc))) {
3598 			skb->next = next;
3599 			goto out;
3600 		}
3601 
3602 		skb = next;
3603 		if (netif_tx_queue_stopped(txq) && skb) {
3604 			rc = NETDEV_TX_BUSY;
3605 			break;
3606 		}
3607 	}
3608 
3609 out:
3610 	*ret = rc;
3611 	return skb;
3612 }
3613 
3614 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3615 					  netdev_features_t features)
3616 {
3617 	if (skb_vlan_tag_present(skb) &&
3618 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3619 		skb = __vlan_hwaccel_push_inside(skb);
3620 	return skb;
3621 }
3622 
3623 int skb_csum_hwoffload_help(struct sk_buff *skb,
3624 			    const netdev_features_t features)
3625 {
3626 	if (unlikely(skb_csum_is_sctp(skb)))
3627 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3628 			skb_crc32c_csum_help(skb);
3629 
3630 	if (features & NETIF_F_HW_CSUM)
3631 		return 0;
3632 
3633 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3634 		switch (skb->csum_offset) {
3635 		case offsetof(struct tcphdr, check):
3636 		case offsetof(struct udphdr, check):
3637 			return 0;
3638 		}
3639 	}
3640 
3641 	return skb_checksum_help(skb);
3642 }
3643 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3644 
3645 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3646 {
3647 	netdev_features_t features;
3648 
3649 	features = netif_skb_features(skb);
3650 	skb = validate_xmit_vlan(skb, features);
3651 	if (unlikely(!skb))
3652 		goto out_null;
3653 
3654 	skb = sk_validate_xmit_skb(skb, dev);
3655 	if (unlikely(!skb))
3656 		goto out_null;
3657 
3658 	if (netif_needs_gso(skb, features)) {
3659 		struct sk_buff *segs;
3660 
3661 		segs = skb_gso_segment(skb, features);
3662 		if (IS_ERR(segs)) {
3663 			goto out_kfree_skb;
3664 		} else if (segs) {
3665 			consume_skb(skb);
3666 			skb = segs;
3667 		}
3668 	} else {
3669 		if (skb_needs_linearize(skb, features) &&
3670 		    __skb_linearize(skb))
3671 			goto out_kfree_skb;
3672 
3673 		/* If packet is not checksummed and device does not
3674 		 * support checksumming for this protocol, complete
3675 		 * checksumming here.
3676 		 */
3677 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3678 			if (skb->encapsulation)
3679 				skb_set_inner_transport_header(skb,
3680 							       skb_checksum_start_offset(skb));
3681 			else
3682 				skb_set_transport_header(skb,
3683 							 skb_checksum_start_offset(skb));
3684 			if (skb_csum_hwoffload_help(skb, features))
3685 				goto out_kfree_skb;
3686 		}
3687 	}
3688 
3689 	skb = validate_xmit_xfrm(skb, features, again);
3690 
3691 	return skb;
3692 
3693 out_kfree_skb:
3694 	kfree_skb(skb);
3695 out_null:
3696 	dev_core_stats_tx_dropped_inc(dev);
3697 	return NULL;
3698 }
3699 
3700 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3701 {
3702 	struct sk_buff *next, *head = NULL, *tail;
3703 
3704 	for (; skb != NULL; skb = next) {
3705 		next = skb->next;
3706 		skb_mark_not_on_list(skb);
3707 
3708 		/* in case skb wont be segmented, point to itself */
3709 		skb->prev = skb;
3710 
3711 		skb = validate_xmit_skb(skb, dev, again);
3712 		if (!skb)
3713 			continue;
3714 
3715 		if (!head)
3716 			head = skb;
3717 		else
3718 			tail->next = skb;
3719 		/* If skb was segmented, skb->prev points to
3720 		 * the last segment. If not, it still contains skb.
3721 		 */
3722 		tail = skb->prev;
3723 	}
3724 	return head;
3725 }
3726 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3727 
3728 static void qdisc_pkt_len_init(struct sk_buff *skb)
3729 {
3730 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3731 
3732 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3733 
3734 	/* To get more precise estimation of bytes sent on wire,
3735 	 * we add to pkt_len the headers size of all segments
3736 	 */
3737 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3738 		u16 gso_segs = shinfo->gso_segs;
3739 		unsigned int hdr_len;
3740 
3741 		/* mac layer + network layer */
3742 		hdr_len = skb_transport_offset(skb);
3743 
3744 		/* + transport layer */
3745 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3746 			const struct tcphdr *th;
3747 			struct tcphdr _tcphdr;
3748 
3749 			th = skb_header_pointer(skb, hdr_len,
3750 						sizeof(_tcphdr), &_tcphdr);
3751 			if (likely(th))
3752 				hdr_len += __tcp_hdrlen(th);
3753 		} else {
3754 			struct udphdr _udphdr;
3755 
3756 			if (skb_header_pointer(skb, hdr_len,
3757 					       sizeof(_udphdr), &_udphdr))
3758 				hdr_len += sizeof(struct udphdr);
3759 		}
3760 
3761 		if (shinfo->gso_type & SKB_GSO_DODGY)
3762 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3763 						shinfo->gso_size);
3764 
3765 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3766 	}
3767 }
3768 
3769 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3770 			     struct sk_buff **to_free,
3771 			     struct netdev_queue *txq)
3772 {
3773 	int rc;
3774 
3775 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3776 	if (rc == NET_XMIT_SUCCESS)
3777 		trace_qdisc_enqueue(q, txq, skb);
3778 	return rc;
3779 }
3780 
3781 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3782 				 struct net_device *dev,
3783 				 struct netdev_queue *txq)
3784 {
3785 	spinlock_t *root_lock = qdisc_lock(q);
3786 	struct sk_buff *to_free = NULL;
3787 	bool contended;
3788 	int rc;
3789 
3790 	qdisc_calculate_pkt_len(skb, q);
3791 
3792 	tcf_set_drop_reason(skb, SKB_DROP_REASON_QDISC_DROP);
3793 
3794 	if (q->flags & TCQ_F_NOLOCK) {
3795 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3796 		    qdisc_run_begin(q)) {
3797 			/* Retest nolock_qdisc_is_empty() within the protection
3798 			 * of q->seqlock to protect from racing with requeuing.
3799 			 */
3800 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3801 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3802 				__qdisc_run(q);
3803 				qdisc_run_end(q);
3804 
3805 				goto no_lock_out;
3806 			}
3807 
3808 			qdisc_bstats_cpu_update(q, skb);
3809 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3810 			    !nolock_qdisc_is_empty(q))
3811 				__qdisc_run(q);
3812 
3813 			qdisc_run_end(q);
3814 			return NET_XMIT_SUCCESS;
3815 		}
3816 
3817 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3818 		qdisc_run(q);
3819 
3820 no_lock_out:
3821 		if (unlikely(to_free))
3822 			kfree_skb_list_reason(to_free,
3823 					      tcf_get_drop_reason(to_free));
3824 		return rc;
3825 	}
3826 
3827 	if (unlikely(READ_ONCE(q->owner) == smp_processor_id())) {
3828 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_RECLASSIFY_LOOP);
3829 		return NET_XMIT_DROP;
3830 	}
3831 	/*
3832 	 * Heuristic to force contended enqueues to serialize on a
3833 	 * separate lock before trying to get qdisc main lock.
3834 	 * This permits qdisc->running owner to get the lock more
3835 	 * often and dequeue packets faster.
3836 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3837 	 * and then other tasks will only enqueue packets. The packets will be
3838 	 * sent after the qdisc owner is scheduled again. To prevent this
3839 	 * scenario the task always serialize on the lock.
3840 	 */
3841 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3842 	if (unlikely(contended))
3843 		spin_lock(&q->busylock);
3844 
3845 	spin_lock(root_lock);
3846 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3847 		__qdisc_drop(skb, &to_free);
3848 		rc = NET_XMIT_DROP;
3849 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3850 		   qdisc_run_begin(q)) {
3851 		/*
3852 		 * This is a work-conserving queue; there are no old skbs
3853 		 * waiting to be sent out; and the qdisc is not running -
3854 		 * xmit the skb directly.
3855 		 */
3856 
3857 		qdisc_bstats_update(q, skb);
3858 
3859 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3860 			if (unlikely(contended)) {
3861 				spin_unlock(&q->busylock);
3862 				contended = false;
3863 			}
3864 			__qdisc_run(q);
3865 		}
3866 
3867 		qdisc_run_end(q);
3868 		rc = NET_XMIT_SUCCESS;
3869 	} else {
3870 		WRITE_ONCE(q->owner, smp_processor_id());
3871 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3872 		WRITE_ONCE(q->owner, -1);
3873 		if (qdisc_run_begin(q)) {
3874 			if (unlikely(contended)) {
3875 				spin_unlock(&q->busylock);
3876 				contended = false;
3877 			}
3878 			__qdisc_run(q);
3879 			qdisc_run_end(q);
3880 		}
3881 	}
3882 	spin_unlock(root_lock);
3883 	if (unlikely(to_free))
3884 		kfree_skb_list_reason(to_free,
3885 				      tcf_get_drop_reason(to_free));
3886 	if (unlikely(contended))
3887 		spin_unlock(&q->busylock);
3888 	return rc;
3889 }
3890 
3891 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3892 static void skb_update_prio(struct sk_buff *skb)
3893 {
3894 	const struct netprio_map *map;
3895 	const struct sock *sk;
3896 	unsigned int prioidx;
3897 
3898 	if (skb->priority)
3899 		return;
3900 	map = rcu_dereference_bh(skb->dev->priomap);
3901 	if (!map)
3902 		return;
3903 	sk = skb_to_full_sk(skb);
3904 	if (!sk)
3905 		return;
3906 
3907 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3908 
3909 	if (prioidx < map->priomap_len)
3910 		skb->priority = map->priomap[prioidx];
3911 }
3912 #else
3913 #define skb_update_prio(skb)
3914 #endif
3915 
3916 /**
3917  *	dev_loopback_xmit - loop back @skb
3918  *	@net: network namespace this loopback is happening in
3919  *	@sk:  sk needed to be a netfilter okfn
3920  *	@skb: buffer to transmit
3921  */
3922 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3923 {
3924 	skb_reset_mac_header(skb);
3925 	__skb_pull(skb, skb_network_offset(skb));
3926 	skb->pkt_type = PACKET_LOOPBACK;
3927 	if (skb->ip_summed == CHECKSUM_NONE)
3928 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3929 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3930 	skb_dst_force(skb);
3931 	netif_rx(skb);
3932 	return 0;
3933 }
3934 EXPORT_SYMBOL(dev_loopback_xmit);
3935 
3936 #ifdef CONFIG_NET_EGRESS
3937 static struct netdev_queue *
3938 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3939 {
3940 	int qm = skb_get_queue_mapping(skb);
3941 
3942 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3943 }
3944 
3945 #ifndef CONFIG_PREEMPT_RT
3946 static bool netdev_xmit_txqueue_skipped(void)
3947 {
3948 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3949 }
3950 
3951 void netdev_xmit_skip_txqueue(bool skip)
3952 {
3953 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3954 }
3955 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3956 
3957 #else
3958 static bool netdev_xmit_txqueue_skipped(void)
3959 {
3960 	return current->net_xmit.skip_txqueue;
3961 }
3962 
3963 void netdev_xmit_skip_txqueue(bool skip)
3964 {
3965 	current->net_xmit.skip_txqueue = skip;
3966 }
3967 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3968 #endif
3969 #endif /* CONFIG_NET_EGRESS */
3970 
3971 #ifdef CONFIG_NET_XGRESS
3972 static int tc_run(struct tcx_entry *entry, struct sk_buff *skb,
3973 		  enum skb_drop_reason *drop_reason)
3974 {
3975 	int ret = TC_ACT_UNSPEC;
3976 #ifdef CONFIG_NET_CLS_ACT
3977 	struct mini_Qdisc *miniq = rcu_dereference_bh(entry->miniq);
3978 	struct tcf_result res;
3979 
3980 	if (!miniq)
3981 		return ret;
3982 
3983 	if (static_branch_unlikely(&tcf_bypass_check_needed_key)) {
3984 		if (tcf_block_bypass_sw(miniq->block))
3985 			return ret;
3986 	}
3987 
3988 	tc_skb_cb(skb)->mru = 0;
3989 	tc_skb_cb(skb)->post_ct = false;
3990 	tcf_set_drop_reason(skb, *drop_reason);
3991 
3992 	mini_qdisc_bstats_cpu_update(miniq, skb);
3993 	ret = tcf_classify(skb, miniq->block, miniq->filter_list, &res, false);
3994 	/* Only tcf related quirks below. */
3995 	switch (ret) {
3996 	case TC_ACT_SHOT:
3997 		*drop_reason = tcf_get_drop_reason(skb);
3998 		mini_qdisc_qstats_cpu_drop(miniq);
3999 		break;
4000 	case TC_ACT_OK:
4001 	case TC_ACT_RECLASSIFY:
4002 		skb->tc_index = TC_H_MIN(res.classid);
4003 		break;
4004 	}
4005 #endif /* CONFIG_NET_CLS_ACT */
4006 	return ret;
4007 }
4008 
4009 static DEFINE_STATIC_KEY_FALSE(tcx_needed_key);
4010 
4011 void tcx_inc(void)
4012 {
4013 	static_branch_inc(&tcx_needed_key);
4014 }
4015 
4016 void tcx_dec(void)
4017 {
4018 	static_branch_dec(&tcx_needed_key);
4019 }
4020 
4021 static __always_inline enum tcx_action_base
4022 tcx_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb,
4023 	const bool needs_mac)
4024 {
4025 	const struct bpf_mprog_fp *fp;
4026 	const struct bpf_prog *prog;
4027 	int ret = TCX_NEXT;
4028 
4029 	if (needs_mac)
4030 		__skb_push(skb, skb->mac_len);
4031 	bpf_mprog_foreach_prog(entry, fp, prog) {
4032 		bpf_compute_data_pointers(skb);
4033 		ret = bpf_prog_run(prog, skb);
4034 		if (ret != TCX_NEXT)
4035 			break;
4036 	}
4037 	if (needs_mac)
4038 		__skb_pull(skb, skb->mac_len);
4039 	return tcx_action_code(skb, ret);
4040 }
4041 
4042 static __always_inline struct sk_buff *
4043 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4044 		   struct net_device *orig_dev, bool *another)
4045 {
4046 	struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
4047 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_INGRESS;
4048 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
4049 	int sch_ret;
4050 
4051 	if (!entry)
4052 		return skb;
4053 
4054 	bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
4055 	if (*pt_prev) {
4056 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
4057 		*pt_prev = NULL;
4058 	}
4059 
4060 	qdisc_skb_cb(skb)->pkt_len = skb->len;
4061 	tcx_set_ingress(skb, true);
4062 
4063 	if (static_branch_unlikely(&tcx_needed_key)) {
4064 		sch_ret = tcx_run(entry, skb, true);
4065 		if (sch_ret != TC_ACT_UNSPEC)
4066 			goto ingress_verdict;
4067 	}
4068 	sch_ret = tc_run(tcx_entry(entry), skb, &drop_reason);
4069 ingress_verdict:
4070 	switch (sch_ret) {
4071 	case TC_ACT_REDIRECT:
4072 		/* skb_mac_header check was done by BPF, so we can safely
4073 		 * push the L2 header back before redirecting to another
4074 		 * netdev.
4075 		 */
4076 		__skb_push(skb, skb->mac_len);
4077 		if (skb_do_redirect(skb) == -EAGAIN) {
4078 			__skb_pull(skb, skb->mac_len);
4079 			*another = true;
4080 			break;
4081 		}
4082 		*ret = NET_RX_SUCCESS;
4083 		bpf_net_ctx_clear(bpf_net_ctx);
4084 		return NULL;
4085 	case TC_ACT_SHOT:
4086 		kfree_skb_reason(skb, drop_reason);
4087 		*ret = NET_RX_DROP;
4088 		bpf_net_ctx_clear(bpf_net_ctx);
4089 		return NULL;
4090 	/* used by tc_run */
4091 	case TC_ACT_STOLEN:
4092 	case TC_ACT_QUEUED:
4093 	case TC_ACT_TRAP:
4094 		consume_skb(skb);
4095 		fallthrough;
4096 	case TC_ACT_CONSUMED:
4097 		*ret = NET_RX_SUCCESS;
4098 		bpf_net_ctx_clear(bpf_net_ctx);
4099 		return NULL;
4100 	}
4101 	bpf_net_ctx_clear(bpf_net_ctx);
4102 
4103 	return skb;
4104 }
4105 
4106 static __always_inline struct sk_buff *
4107 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4108 {
4109 	struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
4110 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_EGRESS;
4111 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
4112 	int sch_ret;
4113 
4114 	if (!entry)
4115 		return skb;
4116 
4117 	bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
4118 
4119 	/* qdisc_skb_cb(skb)->pkt_len & tcx_set_ingress() was
4120 	 * already set by the caller.
4121 	 */
4122 	if (static_branch_unlikely(&tcx_needed_key)) {
4123 		sch_ret = tcx_run(entry, skb, false);
4124 		if (sch_ret != TC_ACT_UNSPEC)
4125 			goto egress_verdict;
4126 	}
4127 	sch_ret = tc_run(tcx_entry(entry), skb, &drop_reason);
4128 egress_verdict:
4129 	switch (sch_ret) {
4130 	case TC_ACT_REDIRECT:
4131 		/* No need to push/pop skb's mac_header here on egress! */
4132 		skb_do_redirect(skb);
4133 		*ret = NET_XMIT_SUCCESS;
4134 		bpf_net_ctx_clear(bpf_net_ctx);
4135 		return NULL;
4136 	case TC_ACT_SHOT:
4137 		kfree_skb_reason(skb, drop_reason);
4138 		*ret = NET_XMIT_DROP;
4139 		bpf_net_ctx_clear(bpf_net_ctx);
4140 		return NULL;
4141 	/* used by tc_run */
4142 	case TC_ACT_STOLEN:
4143 	case TC_ACT_QUEUED:
4144 	case TC_ACT_TRAP:
4145 		consume_skb(skb);
4146 		fallthrough;
4147 	case TC_ACT_CONSUMED:
4148 		*ret = NET_XMIT_SUCCESS;
4149 		bpf_net_ctx_clear(bpf_net_ctx);
4150 		return NULL;
4151 	}
4152 	bpf_net_ctx_clear(bpf_net_ctx);
4153 
4154 	return skb;
4155 }
4156 #else
4157 static __always_inline struct sk_buff *
4158 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4159 		   struct net_device *orig_dev, bool *another)
4160 {
4161 	return skb;
4162 }
4163 
4164 static __always_inline struct sk_buff *
4165 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4166 {
4167 	return skb;
4168 }
4169 #endif /* CONFIG_NET_XGRESS */
4170 
4171 #ifdef CONFIG_XPS
4172 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4173 			       struct xps_dev_maps *dev_maps, unsigned int tci)
4174 {
4175 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
4176 	struct xps_map *map;
4177 	int queue_index = -1;
4178 
4179 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4180 		return queue_index;
4181 
4182 	tci *= dev_maps->num_tc;
4183 	tci += tc;
4184 
4185 	map = rcu_dereference(dev_maps->attr_map[tci]);
4186 	if (map) {
4187 		if (map->len == 1)
4188 			queue_index = map->queues[0];
4189 		else
4190 			queue_index = map->queues[reciprocal_scale(
4191 						skb_get_hash(skb), map->len)];
4192 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4193 			queue_index = -1;
4194 	}
4195 	return queue_index;
4196 }
4197 #endif
4198 
4199 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4200 			 struct sk_buff *skb)
4201 {
4202 #ifdef CONFIG_XPS
4203 	struct xps_dev_maps *dev_maps;
4204 	struct sock *sk = skb->sk;
4205 	int queue_index = -1;
4206 
4207 	if (!static_key_false(&xps_needed))
4208 		return -1;
4209 
4210 	rcu_read_lock();
4211 	if (!static_key_false(&xps_rxqs_needed))
4212 		goto get_cpus_map;
4213 
4214 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4215 	if (dev_maps) {
4216 		int tci = sk_rx_queue_get(sk);
4217 
4218 		if (tci >= 0)
4219 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4220 							  tci);
4221 	}
4222 
4223 get_cpus_map:
4224 	if (queue_index < 0) {
4225 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4226 		if (dev_maps) {
4227 			unsigned int tci = skb->sender_cpu - 1;
4228 
4229 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4230 							  tci);
4231 		}
4232 	}
4233 	rcu_read_unlock();
4234 
4235 	return queue_index;
4236 #else
4237 	return -1;
4238 #endif
4239 }
4240 
4241 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4242 		     struct net_device *sb_dev)
4243 {
4244 	return 0;
4245 }
4246 EXPORT_SYMBOL(dev_pick_tx_zero);
4247 
4248 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4249 		       struct net_device *sb_dev)
4250 {
4251 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4252 }
4253 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4254 
4255 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4256 		     struct net_device *sb_dev)
4257 {
4258 	struct sock *sk = skb->sk;
4259 	int queue_index = sk_tx_queue_get(sk);
4260 
4261 	sb_dev = sb_dev ? : dev;
4262 
4263 	if (queue_index < 0 || skb->ooo_okay ||
4264 	    queue_index >= dev->real_num_tx_queues) {
4265 		int new_index = get_xps_queue(dev, sb_dev, skb);
4266 
4267 		if (new_index < 0)
4268 			new_index = skb_tx_hash(dev, sb_dev, skb);
4269 
4270 		if (queue_index != new_index && sk &&
4271 		    sk_fullsock(sk) &&
4272 		    rcu_access_pointer(sk->sk_dst_cache))
4273 			sk_tx_queue_set(sk, new_index);
4274 
4275 		queue_index = new_index;
4276 	}
4277 
4278 	return queue_index;
4279 }
4280 EXPORT_SYMBOL(netdev_pick_tx);
4281 
4282 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4283 					 struct sk_buff *skb,
4284 					 struct net_device *sb_dev)
4285 {
4286 	int queue_index = 0;
4287 
4288 #ifdef CONFIG_XPS
4289 	u32 sender_cpu = skb->sender_cpu - 1;
4290 
4291 	if (sender_cpu >= (u32)NR_CPUS)
4292 		skb->sender_cpu = raw_smp_processor_id() + 1;
4293 #endif
4294 
4295 	if (dev->real_num_tx_queues != 1) {
4296 		const struct net_device_ops *ops = dev->netdev_ops;
4297 
4298 		if (ops->ndo_select_queue)
4299 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4300 		else
4301 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4302 
4303 		queue_index = netdev_cap_txqueue(dev, queue_index);
4304 	}
4305 
4306 	skb_set_queue_mapping(skb, queue_index);
4307 	return netdev_get_tx_queue(dev, queue_index);
4308 }
4309 
4310 /**
4311  * __dev_queue_xmit() - transmit a buffer
4312  * @skb:	buffer to transmit
4313  * @sb_dev:	suboordinate device used for L2 forwarding offload
4314  *
4315  * Queue a buffer for transmission to a network device. The caller must
4316  * have set the device and priority and built the buffer before calling
4317  * this function. The function can be called from an interrupt.
4318  *
4319  * When calling this method, interrupts MUST be enabled. This is because
4320  * the BH enable code must have IRQs enabled so that it will not deadlock.
4321  *
4322  * Regardless of the return value, the skb is consumed, so it is currently
4323  * difficult to retry a send to this method. (You can bump the ref count
4324  * before sending to hold a reference for retry if you are careful.)
4325  *
4326  * Return:
4327  * * 0				- buffer successfully transmitted
4328  * * positive qdisc return code	- NET_XMIT_DROP etc.
4329  * * negative errno		- other errors
4330  */
4331 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4332 {
4333 	struct net_device *dev = skb->dev;
4334 	struct netdev_queue *txq = NULL;
4335 	struct Qdisc *q;
4336 	int rc = -ENOMEM;
4337 	bool again = false;
4338 
4339 	skb_reset_mac_header(skb);
4340 	skb_assert_len(skb);
4341 
4342 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4343 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4344 
4345 	/* Disable soft irqs for various locks below. Also
4346 	 * stops preemption for RCU.
4347 	 */
4348 	rcu_read_lock_bh();
4349 
4350 	skb_update_prio(skb);
4351 
4352 	qdisc_pkt_len_init(skb);
4353 	tcx_set_ingress(skb, false);
4354 #ifdef CONFIG_NET_EGRESS
4355 	if (static_branch_unlikely(&egress_needed_key)) {
4356 		if (nf_hook_egress_active()) {
4357 			skb = nf_hook_egress(skb, &rc, dev);
4358 			if (!skb)
4359 				goto out;
4360 		}
4361 
4362 		netdev_xmit_skip_txqueue(false);
4363 
4364 		nf_skip_egress(skb, true);
4365 		skb = sch_handle_egress(skb, &rc, dev);
4366 		if (!skb)
4367 			goto out;
4368 		nf_skip_egress(skb, false);
4369 
4370 		if (netdev_xmit_txqueue_skipped())
4371 			txq = netdev_tx_queue_mapping(dev, skb);
4372 	}
4373 #endif
4374 	/* If device/qdisc don't need skb->dst, release it right now while
4375 	 * its hot in this cpu cache.
4376 	 */
4377 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4378 		skb_dst_drop(skb);
4379 	else
4380 		skb_dst_force(skb);
4381 
4382 	if (!txq)
4383 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4384 
4385 	q = rcu_dereference_bh(txq->qdisc);
4386 
4387 	trace_net_dev_queue(skb);
4388 	if (q->enqueue) {
4389 		rc = __dev_xmit_skb(skb, q, dev, txq);
4390 		goto out;
4391 	}
4392 
4393 	/* The device has no queue. Common case for software devices:
4394 	 * loopback, all the sorts of tunnels...
4395 
4396 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4397 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4398 	 * counters.)
4399 	 * However, it is possible, that they rely on protection
4400 	 * made by us here.
4401 
4402 	 * Check this and shot the lock. It is not prone from deadlocks.
4403 	 *Either shot noqueue qdisc, it is even simpler 8)
4404 	 */
4405 	if (dev->flags & IFF_UP) {
4406 		int cpu = smp_processor_id(); /* ok because BHs are off */
4407 
4408 		/* Other cpus might concurrently change txq->xmit_lock_owner
4409 		 * to -1 or to their cpu id, but not to our id.
4410 		 */
4411 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4412 			if (dev_xmit_recursion())
4413 				goto recursion_alert;
4414 
4415 			skb = validate_xmit_skb(skb, dev, &again);
4416 			if (!skb)
4417 				goto out;
4418 
4419 			HARD_TX_LOCK(dev, txq, cpu);
4420 
4421 			if (!netif_xmit_stopped(txq)) {
4422 				dev_xmit_recursion_inc();
4423 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4424 				dev_xmit_recursion_dec();
4425 				if (dev_xmit_complete(rc)) {
4426 					HARD_TX_UNLOCK(dev, txq);
4427 					goto out;
4428 				}
4429 			}
4430 			HARD_TX_UNLOCK(dev, txq);
4431 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4432 					     dev->name);
4433 		} else {
4434 			/* Recursion is detected! It is possible,
4435 			 * unfortunately
4436 			 */
4437 recursion_alert:
4438 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4439 					     dev->name);
4440 		}
4441 	}
4442 
4443 	rc = -ENETDOWN;
4444 	rcu_read_unlock_bh();
4445 
4446 	dev_core_stats_tx_dropped_inc(dev);
4447 	kfree_skb_list(skb);
4448 	return rc;
4449 out:
4450 	rcu_read_unlock_bh();
4451 	return rc;
4452 }
4453 EXPORT_SYMBOL(__dev_queue_xmit);
4454 
4455 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4456 {
4457 	struct net_device *dev = skb->dev;
4458 	struct sk_buff *orig_skb = skb;
4459 	struct netdev_queue *txq;
4460 	int ret = NETDEV_TX_BUSY;
4461 	bool again = false;
4462 
4463 	if (unlikely(!netif_running(dev) ||
4464 		     !netif_carrier_ok(dev)))
4465 		goto drop;
4466 
4467 	skb = validate_xmit_skb_list(skb, dev, &again);
4468 	if (skb != orig_skb)
4469 		goto drop;
4470 
4471 	skb_set_queue_mapping(skb, queue_id);
4472 	txq = skb_get_tx_queue(dev, skb);
4473 
4474 	local_bh_disable();
4475 
4476 	dev_xmit_recursion_inc();
4477 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4478 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4479 		ret = netdev_start_xmit(skb, dev, txq, false);
4480 	HARD_TX_UNLOCK(dev, txq);
4481 	dev_xmit_recursion_dec();
4482 
4483 	local_bh_enable();
4484 	return ret;
4485 drop:
4486 	dev_core_stats_tx_dropped_inc(dev);
4487 	kfree_skb_list(skb);
4488 	return NET_XMIT_DROP;
4489 }
4490 EXPORT_SYMBOL(__dev_direct_xmit);
4491 
4492 /*************************************************************************
4493  *			Receiver routines
4494  *************************************************************************/
4495 static DEFINE_PER_CPU(struct task_struct *, backlog_napi);
4496 
4497 int weight_p __read_mostly = 64;           /* old backlog weight */
4498 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4499 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4500 
4501 /* Called with irq disabled */
4502 static inline void ____napi_schedule(struct softnet_data *sd,
4503 				     struct napi_struct *napi)
4504 {
4505 	struct task_struct *thread;
4506 
4507 	lockdep_assert_irqs_disabled();
4508 
4509 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4510 		/* Paired with smp_mb__before_atomic() in
4511 		 * napi_enable()/dev_set_threaded().
4512 		 * Use READ_ONCE() to guarantee a complete
4513 		 * read on napi->thread. Only call
4514 		 * wake_up_process() when it's not NULL.
4515 		 */
4516 		thread = READ_ONCE(napi->thread);
4517 		if (thread) {
4518 			if (use_backlog_threads() && thread == raw_cpu_read(backlog_napi))
4519 				goto use_local_napi;
4520 
4521 			set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4522 			wake_up_process(thread);
4523 			return;
4524 		}
4525 	}
4526 
4527 use_local_napi:
4528 	list_add_tail(&napi->poll_list, &sd->poll_list);
4529 	WRITE_ONCE(napi->list_owner, smp_processor_id());
4530 	/* If not called from net_rx_action()
4531 	 * we have to raise NET_RX_SOFTIRQ.
4532 	 */
4533 	if (!sd->in_net_rx_action)
4534 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4535 }
4536 
4537 #ifdef CONFIG_RPS
4538 
4539 struct static_key_false rps_needed __read_mostly;
4540 EXPORT_SYMBOL(rps_needed);
4541 struct static_key_false rfs_needed __read_mostly;
4542 EXPORT_SYMBOL(rfs_needed);
4543 
4544 static struct rps_dev_flow *
4545 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4546 	    struct rps_dev_flow *rflow, u16 next_cpu)
4547 {
4548 	if (next_cpu < nr_cpu_ids) {
4549 		u32 head;
4550 #ifdef CONFIG_RFS_ACCEL
4551 		struct netdev_rx_queue *rxqueue;
4552 		struct rps_dev_flow_table *flow_table;
4553 		struct rps_dev_flow *old_rflow;
4554 		u16 rxq_index;
4555 		u32 flow_id;
4556 		int rc;
4557 
4558 		/* Should we steer this flow to a different hardware queue? */
4559 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4560 		    !(dev->features & NETIF_F_NTUPLE))
4561 			goto out;
4562 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4563 		if (rxq_index == skb_get_rx_queue(skb))
4564 			goto out;
4565 
4566 		rxqueue = dev->_rx + rxq_index;
4567 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4568 		if (!flow_table)
4569 			goto out;
4570 		flow_id = skb_get_hash(skb) & flow_table->mask;
4571 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4572 							rxq_index, flow_id);
4573 		if (rc < 0)
4574 			goto out;
4575 		old_rflow = rflow;
4576 		rflow = &flow_table->flows[flow_id];
4577 		WRITE_ONCE(rflow->filter, rc);
4578 		if (old_rflow->filter == rc)
4579 			WRITE_ONCE(old_rflow->filter, RPS_NO_FILTER);
4580 	out:
4581 #endif
4582 		head = READ_ONCE(per_cpu(softnet_data, next_cpu).input_queue_head);
4583 		rps_input_queue_tail_save(&rflow->last_qtail, head);
4584 	}
4585 
4586 	WRITE_ONCE(rflow->cpu, next_cpu);
4587 	return rflow;
4588 }
4589 
4590 /*
4591  * get_rps_cpu is called from netif_receive_skb and returns the target
4592  * CPU from the RPS map of the receiving queue for a given skb.
4593  * rcu_read_lock must be held on entry.
4594  */
4595 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4596 		       struct rps_dev_flow **rflowp)
4597 {
4598 	const struct rps_sock_flow_table *sock_flow_table;
4599 	struct netdev_rx_queue *rxqueue = dev->_rx;
4600 	struct rps_dev_flow_table *flow_table;
4601 	struct rps_map *map;
4602 	int cpu = -1;
4603 	u32 tcpu;
4604 	u32 hash;
4605 
4606 	if (skb_rx_queue_recorded(skb)) {
4607 		u16 index = skb_get_rx_queue(skb);
4608 
4609 		if (unlikely(index >= dev->real_num_rx_queues)) {
4610 			WARN_ONCE(dev->real_num_rx_queues > 1,
4611 				  "%s received packet on queue %u, but number "
4612 				  "of RX queues is %u\n",
4613 				  dev->name, index, dev->real_num_rx_queues);
4614 			goto done;
4615 		}
4616 		rxqueue += index;
4617 	}
4618 
4619 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4620 
4621 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4622 	map = rcu_dereference(rxqueue->rps_map);
4623 	if (!flow_table && !map)
4624 		goto done;
4625 
4626 	skb_reset_network_header(skb);
4627 	hash = skb_get_hash(skb);
4628 	if (!hash)
4629 		goto done;
4630 
4631 	sock_flow_table = rcu_dereference(net_hotdata.rps_sock_flow_table);
4632 	if (flow_table && sock_flow_table) {
4633 		struct rps_dev_flow *rflow;
4634 		u32 next_cpu;
4635 		u32 ident;
4636 
4637 		/* First check into global flow table if there is a match.
4638 		 * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
4639 		 */
4640 		ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
4641 		if ((ident ^ hash) & ~net_hotdata.rps_cpu_mask)
4642 			goto try_rps;
4643 
4644 		next_cpu = ident & net_hotdata.rps_cpu_mask;
4645 
4646 		/* OK, now we know there is a match,
4647 		 * we can look at the local (per receive queue) flow table
4648 		 */
4649 		rflow = &flow_table->flows[hash & flow_table->mask];
4650 		tcpu = rflow->cpu;
4651 
4652 		/*
4653 		 * If the desired CPU (where last recvmsg was done) is
4654 		 * different from current CPU (one in the rx-queue flow
4655 		 * table entry), switch if one of the following holds:
4656 		 *   - Current CPU is unset (>= nr_cpu_ids).
4657 		 *   - Current CPU is offline.
4658 		 *   - The current CPU's queue tail has advanced beyond the
4659 		 *     last packet that was enqueued using this table entry.
4660 		 *     This guarantees that all previous packets for the flow
4661 		 *     have been dequeued, thus preserving in order delivery.
4662 		 */
4663 		if (unlikely(tcpu != next_cpu) &&
4664 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4665 		     ((int)(READ_ONCE(per_cpu(softnet_data, tcpu).input_queue_head) -
4666 		      rflow->last_qtail)) >= 0)) {
4667 			tcpu = next_cpu;
4668 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4669 		}
4670 
4671 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4672 			*rflowp = rflow;
4673 			cpu = tcpu;
4674 			goto done;
4675 		}
4676 	}
4677 
4678 try_rps:
4679 
4680 	if (map) {
4681 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4682 		if (cpu_online(tcpu)) {
4683 			cpu = tcpu;
4684 			goto done;
4685 		}
4686 	}
4687 
4688 done:
4689 	return cpu;
4690 }
4691 
4692 #ifdef CONFIG_RFS_ACCEL
4693 
4694 /**
4695  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4696  * @dev: Device on which the filter was set
4697  * @rxq_index: RX queue index
4698  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4699  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4700  *
4701  * Drivers that implement ndo_rx_flow_steer() should periodically call
4702  * this function for each installed filter and remove the filters for
4703  * which it returns %true.
4704  */
4705 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4706 			 u32 flow_id, u16 filter_id)
4707 {
4708 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4709 	struct rps_dev_flow_table *flow_table;
4710 	struct rps_dev_flow *rflow;
4711 	bool expire = true;
4712 	unsigned int cpu;
4713 
4714 	rcu_read_lock();
4715 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4716 	if (flow_table && flow_id <= flow_table->mask) {
4717 		rflow = &flow_table->flows[flow_id];
4718 		cpu = READ_ONCE(rflow->cpu);
4719 		if (READ_ONCE(rflow->filter) == filter_id && cpu < nr_cpu_ids &&
4720 		    ((int)(READ_ONCE(per_cpu(softnet_data, cpu).input_queue_head) -
4721 			   READ_ONCE(rflow->last_qtail)) <
4722 		     (int)(10 * flow_table->mask)))
4723 			expire = false;
4724 	}
4725 	rcu_read_unlock();
4726 	return expire;
4727 }
4728 EXPORT_SYMBOL(rps_may_expire_flow);
4729 
4730 #endif /* CONFIG_RFS_ACCEL */
4731 
4732 /* Called from hardirq (IPI) context */
4733 static void rps_trigger_softirq(void *data)
4734 {
4735 	struct softnet_data *sd = data;
4736 
4737 	____napi_schedule(sd, &sd->backlog);
4738 	sd->received_rps++;
4739 }
4740 
4741 #endif /* CONFIG_RPS */
4742 
4743 /* Called from hardirq (IPI) context */
4744 static void trigger_rx_softirq(void *data)
4745 {
4746 	struct softnet_data *sd = data;
4747 
4748 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4749 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4750 }
4751 
4752 /*
4753  * After we queued a packet into sd->input_pkt_queue,
4754  * we need to make sure this queue is serviced soon.
4755  *
4756  * - If this is another cpu queue, link it to our rps_ipi_list,
4757  *   and make sure we will process rps_ipi_list from net_rx_action().
4758  *
4759  * - If this is our own queue, NAPI schedule our backlog.
4760  *   Note that this also raises NET_RX_SOFTIRQ.
4761  */
4762 static void napi_schedule_rps(struct softnet_data *sd)
4763 {
4764 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4765 
4766 #ifdef CONFIG_RPS
4767 	if (sd != mysd) {
4768 		if (use_backlog_threads()) {
4769 			__napi_schedule_irqoff(&sd->backlog);
4770 			return;
4771 		}
4772 
4773 		sd->rps_ipi_next = mysd->rps_ipi_list;
4774 		mysd->rps_ipi_list = sd;
4775 
4776 		/* If not called from net_rx_action() or napi_threaded_poll()
4777 		 * we have to raise NET_RX_SOFTIRQ.
4778 		 */
4779 		if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
4780 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4781 		return;
4782 	}
4783 #endif /* CONFIG_RPS */
4784 	__napi_schedule_irqoff(&mysd->backlog);
4785 }
4786 
4787 void kick_defer_list_purge(struct softnet_data *sd, unsigned int cpu)
4788 {
4789 	unsigned long flags;
4790 
4791 	if (use_backlog_threads()) {
4792 		backlog_lock_irq_save(sd, &flags);
4793 
4794 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4795 			__napi_schedule_irqoff(&sd->backlog);
4796 
4797 		backlog_unlock_irq_restore(sd, &flags);
4798 
4799 	} else if (!cmpxchg(&sd->defer_ipi_scheduled, 0, 1)) {
4800 		smp_call_function_single_async(cpu, &sd->defer_csd);
4801 	}
4802 }
4803 
4804 #ifdef CONFIG_NET_FLOW_LIMIT
4805 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4806 #endif
4807 
4808 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4809 {
4810 #ifdef CONFIG_NET_FLOW_LIMIT
4811 	struct sd_flow_limit *fl;
4812 	struct softnet_data *sd;
4813 	unsigned int old_flow, new_flow;
4814 
4815 	if (qlen < (READ_ONCE(net_hotdata.max_backlog) >> 1))
4816 		return false;
4817 
4818 	sd = this_cpu_ptr(&softnet_data);
4819 
4820 	rcu_read_lock();
4821 	fl = rcu_dereference(sd->flow_limit);
4822 	if (fl) {
4823 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4824 		old_flow = fl->history[fl->history_head];
4825 		fl->history[fl->history_head] = new_flow;
4826 
4827 		fl->history_head++;
4828 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4829 
4830 		if (likely(fl->buckets[old_flow]))
4831 			fl->buckets[old_flow]--;
4832 
4833 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4834 			fl->count++;
4835 			rcu_read_unlock();
4836 			return true;
4837 		}
4838 	}
4839 	rcu_read_unlock();
4840 #endif
4841 	return false;
4842 }
4843 
4844 /*
4845  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4846  * queue (may be a remote CPU queue).
4847  */
4848 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4849 			      unsigned int *qtail)
4850 {
4851 	enum skb_drop_reason reason;
4852 	struct softnet_data *sd;
4853 	unsigned long flags;
4854 	unsigned int qlen;
4855 	int max_backlog;
4856 	u32 tail;
4857 
4858 	reason = SKB_DROP_REASON_DEV_READY;
4859 	if (!netif_running(skb->dev))
4860 		goto bad_dev;
4861 
4862 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4863 	sd = &per_cpu(softnet_data, cpu);
4864 
4865 	qlen = skb_queue_len_lockless(&sd->input_pkt_queue);
4866 	max_backlog = READ_ONCE(net_hotdata.max_backlog);
4867 	if (unlikely(qlen > max_backlog))
4868 		goto cpu_backlog_drop;
4869 	backlog_lock_irq_save(sd, &flags);
4870 	qlen = skb_queue_len(&sd->input_pkt_queue);
4871 	if (qlen <= max_backlog && !skb_flow_limit(skb, qlen)) {
4872 		if (!qlen) {
4873 			/* Schedule NAPI for backlog device. We can use
4874 			 * non atomic operation as we own the queue lock.
4875 			 */
4876 			if (!__test_and_set_bit(NAPI_STATE_SCHED,
4877 						&sd->backlog.state))
4878 				napi_schedule_rps(sd);
4879 		}
4880 		__skb_queue_tail(&sd->input_pkt_queue, skb);
4881 		tail = rps_input_queue_tail_incr(sd);
4882 		backlog_unlock_irq_restore(sd, &flags);
4883 
4884 		/* save the tail outside of the critical section */
4885 		rps_input_queue_tail_save(qtail, tail);
4886 		return NET_RX_SUCCESS;
4887 	}
4888 
4889 	backlog_unlock_irq_restore(sd, &flags);
4890 
4891 cpu_backlog_drop:
4892 	atomic_inc(&sd->dropped);
4893 bad_dev:
4894 	dev_core_stats_rx_dropped_inc(skb->dev);
4895 	kfree_skb_reason(skb, reason);
4896 	return NET_RX_DROP;
4897 }
4898 
4899 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4900 {
4901 	struct net_device *dev = skb->dev;
4902 	struct netdev_rx_queue *rxqueue;
4903 
4904 	rxqueue = dev->_rx;
4905 
4906 	if (skb_rx_queue_recorded(skb)) {
4907 		u16 index = skb_get_rx_queue(skb);
4908 
4909 		if (unlikely(index >= dev->real_num_rx_queues)) {
4910 			WARN_ONCE(dev->real_num_rx_queues > 1,
4911 				  "%s received packet on queue %u, but number "
4912 				  "of RX queues is %u\n",
4913 				  dev->name, index, dev->real_num_rx_queues);
4914 
4915 			return rxqueue; /* Return first rxqueue */
4916 		}
4917 		rxqueue += index;
4918 	}
4919 	return rxqueue;
4920 }
4921 
4922 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4923 			     struct bpf_prog *xdp_prog)
4924 {
4925 	void *orig_data, *orig_data_end, *hard_start;
4926 	struct netdev_rx_queue *rxqueue;
4927 	bool orig_bcast, orig_host;
4928 	u32 mac_len, frame_sz;
4929 	__be16 orig_eth_type;
4930 	struct ethhdr *eth;
4931 	u32 metalen, act;
4932 	int off;
4933 
4934 	/* The XDP program wants to see the packet starting at the MAC
4935 	 * header.
4936 	 */
4937 	mac_len = skb->data - skb_mac_header(skb);
4938 	hard_start = skb->data - skb_headroom(skb);
4939 
4940 	/* SKB "head" area always have tailroom for skb_shared_info */
4941 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4942 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4943 
4944 	rxqueue = netif_get_rxqueue(skb);
4945 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4946 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4947 			 skb_headlen(skb) + mac_len, true);
4948 	if (skb_is_nonlinear(skb)) {
4949 		skb_shinfo(skb)->xdp_frags_size = skb->data_len;
4950 		xdp_buff_set_frags_flag(xdp);
4951 	} else {
4952 		xdp_buff_clear_frags_flag(xdp);
4953 	}
4954 
4955 	orig_data_end = xdp->data_end;
4956 	orig_data = xdp->data;
4957 	eth = (struct ethhdr *)xdp->data;
4958 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4959 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4960 	orig_eth_type = eth->h_proto;
4961 
4962 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4963 
4964 	/* check if bpf_xdp_adjust_head was used */
4965 	off = xdp->data - orig_data;
4966 	if (off) {
4967 		if (off > 0)
4968 			__skb_pull(skb, off);
4969 		else if (off < 0)
4970 			__skb_push(skb, -off);
4971 
4972 		skb->mac_header += off;
4973 		skb_reset_network_header(skb);
4974 	}
4975 
4976 	/* check if bpf_xdp_adjust_tail was used */
4977 	off = xdp->data_end - orig_data_end;
4978 	if (off != 0) {
4979 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4980 		skb->len += off; /* positive on grow, negative on shrink */
4981 	}
4982 
4983 	/* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
4984 	 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
4985 	 */
4986 	if (xdp_buff_has_frags(xdp))
4987 		skb->data_len = skb_shinfo(skb)->xdp_frags_size;
4988 	else
4989 		skb->data_len = 0;
4990 
4991 	/* check if XDP changed eth hdr such SKB needs update */
4992 	eth = (struct ethhdr *)xdp->data;
4993 	if ((orig_eth_type != eth->h_proto) ||
4994 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4995 						  skb->dev->dev_addr)) ||
4996 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4997 		__skb_push(skb, ETH_HLEN);
4998 		skb->pkt_type = PACKET_HOST;
4999 		skb->protocol = eth_type_trans(skb, skb->dev);
5000 	}
5001 
5002 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
5003 	 * before calling us again on redirect path. We do not call do_redirect
5004 	 * as we leave that up to the caller.
5005 	 *
5006 	 * Caller is responsible for managing lifetime of skb (i.e. calling
5007 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
5008 	 */
5009 	switch (act) {
5010 	case XDP_REDIRECT:
5011 	case XDP_TX:
5012 		__skb_push(skb, mac_len);
5013 		break;
5014 	case XDP_PASS:
5015 		metalen = xdp->data - xdp->data_meta;
5016 		if (metalen)
5017 			skb_metadata_set(skb, metalen);
5018 		break;
5019 	}
5020 
5021 	return act;
5022 }
5023 
5024 static int
5025 netif_skb_check_for_xdp(struct sk_buff **pskb, struct bpf_prog *prog)
5026 {
5027 	struct sk_buff *skb = *pskb;
5028 	int err, hroom, troom;
5029 
5030 	if (!skb_cow_data_for_xdp(this_cpu_read(system_page_pool), pskb, prog))
5031 		return 0;
5032 
5033 	/* In case we have to go down the path and also linearize,
5034 	 * then lets do the pskb_expand_head() work just once here.
5035 	 */
5036 	hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
5037 	troom = skb->tail + skb->data_len - skb->end;
5038 	err = pskb_expand_head(skb,
5039 			       hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
5040 			       troom > 0 ? troom + 128 : 0, GFP_ATOMIC);
5041 	if (err)
5042 		return err;
5043 
5044 	return skb_linearize(skb);
5045 }
5046 
5047 static u32 netif_receive_generic_xdp(struct sk_buff **pskb,
5048 				     struct xdp_buff *xdp,
5049 				     struct bpf_prog *xdp_prog)
5050 {
5051 	struct sk_buff *skb = *pskb;
5052 	u32 mac_len, act = XDP_DROP;
5053 
5054 	/* Reinjected packets coming from act_mirred or similar should
5055 	 * not get XDP generic processing.
5056 	 */
5057 	if (skb_is_redirected(skb))
5058 		return XDP_PASS;
5059 
5060 	/* XDP packets must have sufficient headroom of XDP_PACKET_HEADROOM
5061 	 * bytes. This is the guarantee that also native XDP provides,
5062 	 * thus we need to do it here as well.
5063 	 */
5064 	mac_len = skb->data - skb_mac_header(skb);
5065 	__skb_push(skb, mac_len);
5066 
5067 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
5068 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
5069 		if (netif_skb_check_for_xdp(pskb, xdp_prog))
5070 			goto do_drop;
5071 	}
5072 
5073 	__skb_pull(*pskb, mac_len);
5074 
5075 	act = bpf_prog_run_generic_xdp(*pskb, xdp, xdp_prog);
5076 	switch (act) {
5077 	case XDP_REDIRECT:
5078 	case XDP_TX:
5079 	case XDP_PASS:
5080 		break;
5081 	default:
5082 		bpf_warn_invalid_xdp_action((*pskb)->dev, xdp_prog, act);
5083 		fallthrough;
5084 	case XDP_ABORTED:
5085 		trace_xdp_exception((*pskb)->dev, xdp_prog, act);
5086 		fallthrough;
5087 	case XDP_DROP:
5088 	do_drop:
5089 		kfree_skb(*pskb);
5090 		break;
5091 	}
5092 
5093 	return act;
5094 }
5095 
5096 /* When doing generic XDP we have to bypass the qdisc layer and the
5097  * network taps in order to match in-driver-XDP behavior. This also means
5098  * that XDP packets are able to starve other packets going through a qdisc,
5099  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
5100  * queues, so they do not have this starvation issue.
5101  */
5102 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
5103 {
5104 	struct net_device *dev = skb->dev;
5105 	struct netdev_queue *txq;
5106 	bool free_skb = true;
5107 	int cpu, rc;
5108 
5109 	txq = netdev_core_pick_tx(dev, skb, NULL);
5110 	cpu = smp_processor_id();
5111 	HARD_TX_LOCK(dev, txq, cpu);
5112 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
5113 		rc = netdev_start_xmit(skb, dev, txq, 0);
5114 		if (dev_xmit_complete(rc))
5115 			free_skb = false;
5116 	}
5117 	HARD_TX_UNLOCK(dev, txq);
5118 	if (free_skb) {
5119 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
5120 		dev_core_stats_tx_dropped_inc(dev);
5121 		kfree_skb(skb);
5122 	}
5123 }
5124 
5125 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
5126 
5127 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb)
5128 {
5129 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
5130 
5131 	if (xdp_prog) {
5132 		struct xdp_buff xdp;
5133 		u32 act;
5134 		int err;
5135 
5136 		bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
5137 		act = netif_receive_generic_xdp(pskb, &xdp, xdp_prog);
5138 		if (act != XDP_PASS) {
5139 			switch (act) {
5140 			case XDP_REDIRECT:
5141 				err = xdp_do_generic_redirect((*pskb)->dev, *pskb,
5142 							      &xdp, xdp_prog);
5143 				if (err)
5144 					goto out_redir;
5145 				break;
5146 			case XDP_TX:
5147 				generic_xdp_tx(*pskb, xdp_prog);
5148 				break;
5149 			}
5150 			bpf_net_ctx_clear(bpf_net_ctx);
5151 			return XDP_DROP;
5152 		}
5153 		bpf_net_ctx_clear(bpf_net_ctx);
5154 	}
5155 	return XDP_PASS;
5156 out_redir:
5157 	bpf_net_ctx_clear(bpf_net_ctx);
5158 	kfree_skb_reason(*pskb, SKB_DROP_REASON_XDP);
5159 	return XDP_DROP;
5160 }
5161 EXPORT_SYMBOL_GPL(do_xdp_generic);
5162 
5163 static int netif_rx_internal(struct sk_buff *skb)
5164 {
5165 	int ret;
5166 
5167 	net_timestamp_check(READ_ONCE(net_hotdata.tstamp_prequeue), skb);
5168 
5169 	trace_netif_rx(skb);
5170 
5171 #ifdef CONFIG_RPS
5172 	if (static_branch_unlikely(&rps_needed)) {
5173 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5174 		int cpu;
5175 
5176 		rcu_read_lock();
5177 
5178 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
5179 		if (cpu < 0)
5180 			cpu = smp_processor_id();
5181 
5182 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5183 
5184 		rcu_read_unlock();
5185 	} else
5186 #endif
5187 	{
5188 		unsigned int qtail;
5189 
5190 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
5191 	}
5192 	return ret;
5193 }
5194 
5195 /**
5196  *	__netif_rx	-	Slightly optimized version of netif_rx
5197  *	@skb: buffer to post
5198  *
5199  *	This behaves as netif_rx except that it does not disable bottom halves.
5200  *	As a result this function may only be invoked from the interrupt context
5201  *	(either hard or soft interrupt).
5202  */
5203 int __netif_rx(struct sk_buff *skb)
5204 {
5205 	int ret;
5206 
5207 	lockdep_assert_once(hardirq_count() | softirq_count());
5208 
5209 	trace_netif_rx_entry(skb);
5210 	ret = netif_rx_internal(skb);
5211 	trace_netif_rx_exit(ret);
5212 	return ret;
5213 }
5214 EXPORT_SYMBOL(__netif_rx);
5215 
5216 /**
5217  *	netif_rx	-	post buffer to the network code
5218  *	@skb: buffer to post
5219  *
5220  *	This function receives a packet from a device driver and queues it for
5221  *	the upper (protocol) levels to process via the backlog NAPI device. It
5222  *	always succeeds. The buffer may be dropped during processing for
5223  *	congestion control or by the protocol layers.
5224  *	The network buffer is passed via the backlog NAPI device. Modern NIC
5225  *	driver should use NAPI and GRO.
5226  *	This function can used from interrupt and from process context. The
5227  *	caller from process context must not disable interrupts before invoking
5228  *	this function.
5229  *
5230  *	return values:
5231  *	NET_RX_SUCCESS	(no congestion)
5232  *	NET_RX_DROP     (packet was dropped)
5233  *
5234  */
5235 int netif_rx(struct sk_buff *skb)
5236 {
5237 	bool need_bh_off = !(hardirq_count() | softirq_count());
5238 	int ret;
5239 
5240 	if (need_bh_off)
5241 		local_bh_disable();
5242 	trace_netif_rx_entry(skb);
5243 	ret = netif_rx_internal(skb);
5244 	trace_netif_rx_exit(ret);
5245 	if (need_bh_off)
5246 		local_bh_enable();
5247 	return ret;
5248 }
5249 EXPORT_SYMBOL(netif_rx);
5250 
5251 static __latent_entropy void net_tx_action(struct softirq_action *h)
5252 {
5253 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5254 
5255 	if (sd->completion_queue) {
5256 		struct sk_buff *clist;
5257 
5258 		local_irq_disable();
5259 		clist = sd->completion_queue;
5260 		sd->completion_queue = NULL;
5261 		local_irq_enable();
5262 
5263 		while (clist) {
5264 			struct sk_buff *skb = clist;
5265 
5266 			clist = clist->next;
5267 
5268 			WARN_ON(refcount_read(&skb->users));
5269 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5270 				trace_consume_skb(skb, net_tx_action);
5271 			else
5272 				trace_kfree_skb(skb, net_tx_action,
5273 						get_kfree_skb_cb(skb)->reason, NULL);
5274 
5275 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5276 				__kfree_skb(skb);
5277 			else
5278 				__napi_kfree_skb(skb,
5279 						 get_kfree_skb_cb(skb)->reason);
5280 		}
5281 	}
5282 
5283 	if (sd->output_queue) {
5284 		struct Qdisc *head;
5285 
5286 		local_irq_disable();
5287 		head = sd->output_queue;
5288 		sd->output_queue = NULL;
5289 		sd->output_queue_tailp = &sd->output_queue;
5290 		local_irq_enable();
5291 
5292 		rcu_read_lock();
5293 
5294 		while (head) {
5295 			struct Qdisc *q = head;
5296 			spinlock_t *root_lock = NULL;
5297 
5298 			head = head->next_sched;
5299 
5300 			/* We need to make sure head->next_sched is read
5301 			 * before clearing __QDISC_STATE_SCHED
5302 			 */
5303 			smp_mb__before_atomic();
5304 
5305 			if (!(q->flags & TCQ_F_NOLOCK)) {
5306 				root_lock = qdisc_lock(q);
5307 				spin_lock(root_lock);
5308 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5309 						     &q->state))) {
5310 				/* There is a synchronize_net() between
5311 				 * STATE_DEACTIVATED flag being set and
5312 				 * qdisc_reset()/some_qdisc_is_busy() in
5313 				 * dev_deactivate(), so we can safely bail out
5314 				 * early here to avoid data race between
5315 				 * qdisc_deactivate() and some_qdisc_is_busy()
5316 				 * for lockless qdisc.
5317 				 */
5318 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5319 				continue;
5320 			}
5321 
5322 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5323 			qdisc_run(q);
5324 			if (root_lock)
5325 				spin_unlock(root_lock);
5326 		}
5327 
5328 		rcu_read_unlock();
5329 	}
5330 
5331 	xfrm_dev_backlog(sd);
5332 }
5333 
5334 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5335 /* This hook is defined here for ATM LANE */
5336 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5337 			     unsigned char *addr) __read_mostly;
5338 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5339 #endif
5340 
5341 /**
5342  *	netdev_is_rx_handler_busy - check if receive handler is registered
5343  *	@dev: device to check
5344  *
5345  *	Check if a receive handler is already registered for a given device.
5346  *	Return true if there one.
5347  *
5348  *	The caller must hold the rtnl_mutex.
5349  */
5350 bool netdev_is_rx_handler_busy(struct net_device *dev)
5351 {
5352 	ASSERT_RTNL();
5353 	return dev && rtnl_dereference(dev->rx_handler);
5354 }
5355 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5356 
5357 /**
5358  *	netdev_rx_handler_register - register receive handler
5359  *	@dev: device to register a handler for
5360  *	@rx_handler: receive handler to register
5361  *	@rx_handler_data: data pointer that is used by rx handler
5362  *
5363  *	Register a receive handler for a device. This handler will then be
5364  *	called from __netif_receive_skb. A negative errno code is returned
5365  *	on a failure.
5366  *
5367  *	The caller must hold the rtnl_mutex.
5368  *
5369  *	For a general description of rx_handler, see enum rx_handler_result.
5370  */
5371 int netdev_rx_handler_register(struct net_device *dev,
5372 			       rx_handler_func_t *rx_handler,
5373 			       void *rx_handler_data)
5374 {
5375 	if (netdev_is_rx_handler_busy(dev))
5376 		return -EBUSY;
5377 
5378 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5379 		return -EINVAL;
5380 
5381 	/* Note: rx_handler_data must be set before rx_handler */
5382 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5383 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5384 
5385 	return 0;
5386 }
5387 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5388 
5389 /**
5390  *	netdev_rx_handler_unregister - unregister receive handler
5391  *	@dev: device to unregister a handler from
5392  *
5393  *	Unregister a receive handler from a device.
5394  *
5395  *	The caller must hold the rtnl_mutex.
5396  */
5397 void netdev_rx_handler_unregister(struct net_device *dev)
5398 {
5399 
5400 	ASSERT_RTNL();
5401 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5402 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5403 	 * section has a guarantee to see a non NULL rx_handler_data
5404 	 * as well.
5405 	 */
5406 	synchronize_net();
5407 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5408 }
5409 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5410 
5411 /*
5412  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5413  * the special handling of PFMEMALLOC skbs.
5414  */
5415 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5416 {
5417 	switch (skb->protocol) {
5418 	case htons(ETH_P_ARP):
5419 	case htons(ETH_P_IP):
5420 	case htons(ETH_P_IPV6):
5421 	case htons(ETH_P_8021Q):
5422 	case htons(ETH_P_8021AD):
5423 		return true;
5424 	default:
5425 		return false;
5426 	}
5427 }
5428 
5429 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5430 			     int *ret, struct net_device *orig_dev)
5431 {
5432 	if (nf_hook_ingress_active(skb)) {
5433 		int ingress_retval;
5434 
5435 		if (*pt_prev) {
5436 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5437 			*pt_prev = NULL;
5438 		}
5439 
5440 		rcu_read_lock();
5441 		ingress_retval = nf_hook_ingress(skb);
5442 		rcu_read_unlock();
5443 		return ingress_retval;
5444 	}
5445 	return 0;
5446 }
5447 
5448 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5449 				    struct packet_type **ppt_prev)
5450 {
5451 	struct packet_type *ptype, *pt_prev;
5452 	rx_handler_func_t *rx_handler;
5453 	struct sk_buff *skb = *pskb;
5454 	struct net_device *orig_dev;
5455 	bool deliver_exact = false;
5456 	int ret = NET_RX_DROP;
5457 	__be16 type;
5458 
5459 	net_timestamp_check(!READ_ONCE(net_hotdata.tstamp_prequeue), skb);
5460 
5461 	trace_netif_receive_skb(skb);
5462 
5463 	orig_dev = skb->dev;
5464 
5465 	skb_reset_network_header(skb);
5466 	if (!skb_transport_header_was_set(skb))
5467 		skb_reset_transport_header(skb);
5468 	skb_reset_mac_len(skb);
5469 
5470 	pt_prev = NULL;
5471 
5472 another_round:
5473 	skb->skb_iif = skb->dev->ifindex;
5474 
5475 	__this_cpu_inc(softnet_data.processed);
5476 
5477 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5478 		int ret2;
5479 
5480 		migrate_disable();
5481 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog),
5482 				      &skb);
5483 		migrate_enable();
5484 
5485 		if (ret2 != XDP_PASS) {
5486 			ret = NET_RX_DROP;
5487 			goto out;
5488 		}
5489 	}
5490 
5491 	if (eth_type_vlan(skb->protocol)) {
5492 		skb = skb_vlan_untag(skb);
5493 		if (unlikely(!skb))
5494 			goto out;
5495 	}
5496 
5497 	if (skb_skip_tc_classify(skb))
5498 		goto skip_classify;
5499 
5500 	if (pfmemalloc)
5501 		goto skip_taps;
5502 
5503 	list_for_each_entry_rcu(ptype, &net_hotdata.ptype_all, list) {
5504 		if (pt_prev)
5505 			ret = deliver_skb(skb, pt_prev, orig_dev);
5506 		pt_prev = ptype;
5507 	}
5508 
5509 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5510 		if (pt_prev)
5511 			ret = deliver_skb(skb, pt_prev, orig_dev);
5512 		pt_prev = ptype;
5513 	}
5514 
5515 skip_taps:
5516 #ifdef CONFIG_NET_INGRESS
5517 	if (static_branch_unlikely(&ingress_needed_key)) {
5518 		bool another = false;
5519 
5520 		nf_skip_egress(skb, true);
5521 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5522 					 &another);
5523 		if (another)
5524 			goto another_round;
5525 		if (!skb)
5526 			goto out;
5527 
5528 		nf_skip_egress(skb, false);
5529 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5530 			goto out;
5531 	}
5532 #endif
5533 	skb_reset_redirect(skb);
5534 skip_classify:
5535 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5536 		goto drop;
5537 
5538 	if (skb_vlan_tag_present(skb)) {
5539 		if (pt_prev) {
5540 			ret = deliver_skb(skb, pt_prev, orig_dev);
5541 			pt_prev = NULL;
5542 		}
5543 		if (vlan_do_receive(&skb))
5544 			goto another_round;
5545 		else if (unlikely(!skb))
5546 			goto out;
5547 	}
5548 
5549 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5550 	if (rx_handler) {
5551 		if (pt_prev) {
5552 			ret = deliver_skb(skb, pt_prev, orig_dev);
5553 			pt_prev = NULL;
5554 		}
5555 		switch (rx_handler(&skb)) {
5556 		case RX_HANDLER_CONSUMED:
5557 			ret = NET_RX_SUCCESS;
5558 			goto out;
5559 		case RX_HANDLER_ANOTHER:
5560 			goto another_round;
5561 		case RX_HANDLER_EXACT:
5562 			deliver_exact = true;
5563 			break;
5564 		case RX_HANDLER_PASS:
5565 			break;
5566 		default:
5567 			BUG();
5568 		}
5569 	}
5570 
5571 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5572 check_vlan_id:
5573 		if (skb_vlan_tag_get_id(skb)) {
5574 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5575 			 * find vlan device.
5576 			 */
5577 			skb->pkt_type = PACKET_OTHERHOST;
5578 		} else if (eth_type_vlan(skb->protocol)) {
5579 			/* Outer header is 802.1P with vlan 0, inner header is
5580 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5581 			 * not find vlan dev for vlan id 0.
5582 			 */
5583 			__vlan_hwaccel_clear_tag(skb);
5584 			skb = skb_vlan_untag(skb);
5585 			if (unlikely(!skb))
5586 				goto out;
5587 			if (vlan_do_receive(&skb))
5588 				/* After stripping off 802.1P header with vlan 0
5589 				 * vlan dev is found for inner header.
5590 				 */
5591 				goto another_round;
5592 			else if (unlikely(!skb))
5593 				goto out;
5594 			else
5595 				/* We have stripped outer 802.1P vlan 0 header.
5596 				 * But could not find vlan dev.
5597 				 * check again for vlan id to set OTHERHOST.
5598 				 */
5599 				goto check_vlan_id;
5600 		}
5601 		/* Note: we might in the future use prio bits
5602 		 * and set skb->priority like in vlan_do_receive()
5603 		 * For the time being, just ignore Priority Code Point
5604 		 */
5605 		__vlan_hwaccel_clear_tag(skb);
5606 	}
5607 
5608 	type = skb->protocol;
5609 
5610 	/* deliver only exact match when indicated */
5611 	if (likely(!deliver_exact)) {
5612 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5613 				       &ptype_base[ntohs(type) &
5614 						   PTYPE_HASH_MASK]);
5615 	}
5616 
5617 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5618 			       &orig_dev->ptype_specific);
5619 
5620 	if (unlikely(skb->dev != orig_dev)) {
5621 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5622 				       &skb->dev->ptype_specific);
5623 	}
5624 
5625 	if (pt_prev) {
5626 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5627 			goto drop;
5628 		*ppt_prev = pt_prev;
5629 	} else {
5630 drop:
5631 		if (!deliver_exact)
5632 			dev_core_stats_rx_dropped_inc(skb->dev);
5633 		else
5634 			dev_core_stats_rx_nohandler_inc(skb->dev);
5635 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5636 		/* Jamal, now you will not able to escape explaining
5637 		 * me how you were going to use this. :-)
5638 		 */
5639 		ret = NET_RX_DROP;
5640 	}
5641 
5642 out:
5643 	/* The invariant here is that if *ppt_prev is not NULL
5644 	 * then skb should also be non-NULL.
5645 	 *
5646 	 * Apparently *ppt_prev assignment above holds this invariant due to
5647 	 * skb dereferencing near it.
5648 	 */
5649 	*pskb = skb;
5650 	return ret;
5651 }
5652 
5653 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5654 {
5655 	struct net_device *orig_dev = skb->dev;
5656 	struct packet_type *pt_prev = NULL;
5657 	int ret;
5658 
5659 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5660 	if (pt_prev)
5661 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5662 					 skb->dev, pt_prev, orig_dev);
5663 	return ret;
5664 }
5665 
5666 /**
5667  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5668  *	@skb: buffer to process
5669  *
5670  *	More direct receive version of netif_receive_skb().  It should
5671  *	only be used by callers that have a need to skip RPS and Generic XDP.
5672  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5673  *
5674  *	This function may only be called from softirq context and interrupts
5675  *	should be enabled.
5676  *
5677  *	Return values (usually ignored):
5678  *	NET_RX_SUCCESS: no congestion
5679  *	NET_RX_DROP: packet was dropped
5680  */
5681 int netif_receive_skb_core(struct sk_buff *skb)
5682 {
5683 	int ret;
5684 
5685 	rcu_read_lock();
5686 	ret = __netif_receive_skb_one_core(skb, false);
5687 	rcu_read_unlock();
5688 
5689 	return ret;
5690 }
5691 EXPORT_SYMBOL(netif_receive_skb_core);
5692 
5693 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5694 						  struct packet_type *pt_prev,
5695 						  struct net_device *orig_dev)
5696 {
5697 	struct sk_buff *skb, *next;
5698 
5699 	if (!pt_prev)
5700 		return;
5701 	if (list_empty(head))
5702 		return;
5703 	if (pt_prev->list_func != NULL)
5704 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5705 				   ip_list_rcv, head, pt_prev, orig_dev);
5706 	else
5707 		list_for_each_entry_safe(skb, next, head, list) {
5708 			skb_list_del_init(skb);
5709 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5710 		}
5711 }
5712 
5713 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5714 {
5715 	/* Fast-path assumptions:
5716 	 * - There is no RX handler.
5717 	 * - Only one packet_type matches.
5718 	 * If either of these fails, we will end up doing some per-packet
5719 	 * processing in-line, then handling the 'last ptype' for the whole
5720 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5721 	 * because the 'last ptype' must be constant across the sublist, and all
5722 	 * other ptypes are handled per-packet.
5723 	 */
5724 	/* Current (common) ptype of sublist */
5725 	struct packet_type *pt_curr = NULL;
5726 	/* Current (common) orig_dev of sublist */
5727 	struct net_device *od_curr = NULL;
5728 	struct list_head sublist;
5729 	struct sk_buff *skb, *next;
5730 
5731 	INIT_LIST_HEAD(&sublist);
5732 	list_for_each_entry_safe(skb, next, head, list) {
5733 		struct net_device *orig_dev = skb->dev;
5734 		struct packet_type *pt_prev = NULL;
5735 
5736 		skb_list_del_init(skb);
5737 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5738 		if (!pt_prev)
5739 			continue;
5740 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5741 			/* dispatch old sublist */
5742 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5743 			/* start new sublist */
5744 			INIT_LIST_HEAD(&sublist);
5745 			pt_curr = pt_prev;
5746 			od_curr = orig_dev;
5747 		}
5748 		list_add_tail(&skb->list, &sublist);
5749 	}
5750 
5751 	/* dispatch final sublist */
5752 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5753 }
5754 
5755 static int __netif_receive_skb(struct sk_buff *skb)
5756 {
5757 	int ret;
5758 
5759 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5760 		unsigned int noreclaim_flag;
5761 
5762 		/*
5763 		 * PFMEMALLOC skbs are special, they should
5764 		 * - be delivered to SOCK_MEMALLOC sockets only
5765 		 * - stay away from userspace
5766 		 * - have bounded memory usage
5767 		 *
5768 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5769 		 * context down to all allocation sites.
5770 		 */
5771 		noreclaim_flag = memalloc_noreclaim_save();
5772 		ret = __netif_receive_skb_one_core(skb, true);
5773 		memalloc_noreclaim_restore(noreclaim_flag);
5774 	} else
5775 		ret = __netif_receive_skb_one_core(skb, false);
5776 
5777 	return ret;
5778 }
5779 
5780 static void __netif_receive_skb_list(struct list_head *head)
5781 {
5782 	unsigned long noreclaim_flag = 0;
5783 	struct sk_buff *skb, *next;
5784 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5785 
5786 	list_for_each_entry_safe(skb, next, head, list) {
5787 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5788 			struct list_head sublist;
5789 
5790 			/* Handle the previous sublist */
5791 			list_cut_before(&sublist, head, &skb->list);
5792 			if (!list_empty(&sublist))
5793 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5794 			pfmemalloc = !pfmemalloc;
5795 			/* See comments in __netif_receive_skb */
5796 			if (pfmemalloc)
5797 				noreclaim_flag = memalloc_noreclaim_save();
5798 			else
5799 				memalloc_noreclaim_restore(noreclaim_flag);
5800 		}
5801 	}
5802 	/* Handle the remaining sublist */
5803 	if (!list_empty(head))
5804 		__netif_receive_skb_list_core(head, pfmemalloc);
5805 	/* Restore pflags */
5806 	if (pfmemalloc)
5807 		memalloc_noreclaim_restore(noreclaim_flag);
5808 }
5809 
5810 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5811 {
5812 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5813 	struct bpf_prog *new = xdp->prog;
5814 	int ret = 0;
5815 
5816 	switch (xdp->command) {
5817 	case XDP_SETUP_PROG:
5818 		rcu_assign_pointer(dev->xdp_prog, new);
5819 		if (old)
5820 			bpf_prog_put(old);
5821 
5822 		if (old && !new) {
5823 			static_branch_dec(&generic_xdp_needed_key);
5824 		} else if (new && !old) {
5825 			static_branch_inc(&generic_xdp_needed_key);
5826 			dev_disable_lro(dev);
5827 			dev_disable_gro_hw(dev);
5828 		}
5829 		break;
5830 
5831 	default:
5832 		ret = -EINVAL;
5833 		break;
5834 	}
5835 
5836 	return ret;
5837 }
5838 
5839 static int netif_receive_skb_internal(struct sk_buff *skb)
5840 {
5841 	int ret;
5842 
5843 	net_timestamp_check(READ_ONCE(net_hotdata.tstamp_prequeue), skb);
5844 
5845 	if (skb_defer_rx_timestamp(skb))
5846 		return NET_RX_SUCCESS;
5847 
5848 	rcu_read_lock();
5849 #ifdef CONFIG_RPS
5850 	if (static_branch_unlikely(&rps_needed)) {
5851 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5852 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5853 
5854 		if (cpu >= 0) {
5855 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5856 			rcu_read_unlock();
5857 			return ret;
5858 		}
5859 	}
5860 #endif
5861 	ret = __netif_receive_skb(skb);
5862 	rcu_read_unlock();
5863 	return ret;
5864 }
5865 
5866 void netif_receive_skb_list_internal(struct list_head *head)
5867 {
5868 	struct sk_buff *skb, *next;
5869 	struct list_head sublist;
5870 
5871 	INIT_LIST_HEAD(&sublist);
5872 	list_for_each_entry_safe(skb, next, head, list) {
5873 		net_timestamp_check(READ_ONCE(net_hotdata.tstamp_prequeue),
5874 				    skb);
5875 		skb_list_del_init(skb);
5876 		if (!skb_defer_rx_timestamp(skb))
5877 			list_add_tail(&skb->list, &sublist);
5878 	}
5879 	list_splice_init(&sublist, head);
5880 
5881 	rcu_read_lock();
5882 #ifdef CONFIG_RPS
5883 	if (static_branch_unlikely(&rps_needed)) {
5884 		list_for_each_entry_safe(skb, next, head, list) {
5885 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5886 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5887 
5888 			if (cpu >= 0) {
5889 				/* Will be handled, remove from list */
5890 				skb_list_del_init(skb);
5891 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5892 			}
5893 		}
5894 	}
5895 #endif
5896 	__netif_receive_skb_list(head);
5897 	rcu_read_unlock();
5898 }
5899 
5900 /**
5901  *	netif_receive_skb - process receive buffer from network
5902  *	@skb: buffer to process
5903  *
5904  *	netif_receive_skb() is the main receive data processing function.
5905  *	It always succeeds. The buffer may be dropped during processing
5906  *	for congestion control or by the protocol layers.
5907  *
5908  *	This function may only be called from softirq context and interrupts
5909  *	should be enabled.
5910  *
5911  *	Return values (usually ignored):
5912  *	NET_RX_SUCCESS: no congestion
5913  *	NET_RX_DROP: packet was dropped
5914  */
5915 int netif_receive_skb(struct sk_buff *skb)
5916 {
5917 	int ret;
5918 
5919 	trace_netif_receive_skb_entry(skb);
5920 
5921 	ret = netif_receive_skb_internal(skb);
5922 	trace_netif_receive_skb_exit(ret);
5923 
5924 	return ret;
5925 }
5926 EXPORT_SYMBOL(netif_receive_skb);
5927 
5928 /**
5929  *	netif_receive_skb_list - process many receive buffers from network
5930  *	@head: list of skbs to process.
5931  *
5932  *	Since return value of netif_receive_skb() is normally ignored, and
5933  *	wouldn't be meaningful for a list, this function returns void.
5934  *
5935  *	This function may only be called from softirq context and interrupts
5936  *	should be enabled.
5937  */
5938 void netif_receive_skb_list(struct list_head *head)
5939 {
5940 	struct sk_buff *skb;
5941 
5942 	if (list_empty(head))
5943 		return;
5944 	if (trace_netif_receive_skb_list_entry_enabled()) {
5945 		list_for_each_entry(skb, head, list)
5946 			trace_netif_receive_skb_list_entry(skb);
5947 	}
5948 	netif_receive_skb_list_internal(head);
5949 	trace_netif_receive_skb_list_exit(0);
5950 }
5951 EXPORT_SYMBOL(netif_receive_skb_list);
5952 
5953 static DEFINE_PER_CPU(struct work_struct, flush_works);
5954 
5955 /* Network device is going away, flush any packets still pending */
5956 static void flush_backlog(struct work_struct *work)
5957 {
5958 	struct sk_buff *skb, *tmp;
5959 	struct softnet_data *sd;
5960 
5961 	local_bh_disable();
5962 	sd = this_cpu_ptr(&softnet_data);
5963 
5964 	backlog_lock_irq_disable(sd);
5965 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5966 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5967 			__skb_unlink(skb, &sd->input_pkt_queue);
5968 			dev_kfree_skb_irq(skb);
5969 			rps_input_queue_head_incr(sd);
5970 		}
5971 	}
5972 	backlog_unlock_irq_enable(sd);
5973 
5974 	local_lock_nested_bh(&softnet_data.process_queue_bh_lock);
5975 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5976 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5977 			__skb_unlink(skb, &sd->process_queue);
5978 			kfree_skb(skb);
5979 			rps_input_queue_head_incr(sd);
5980 		}
5981 	}
5982 	local_unlock_nested_bh(&softnet_data.process_queue_bh_lock);
5983 	local_bh_enable();
5984 }
5985 
5986 static bool flush_required(int cpu)
5987 {
5988 #if IS_ENABLED(CONFIG_RPS)
5989 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5990 	bool do_flush;
5991 
5992 	backlog_lock_irq_disable(sd);
5993 
5994 	/* as insertion into process_queue happens with the rps lock held,
5995 	 * process_queue access may race only with dequeue
5996 	 */
5997 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5998 		   !skb_queue_empty_lockless(&sd->process_queue);
5999 	backlog_unlock_irq_enable(sd);
6000 
6001 	return do_flush;
6002 #endif
6003 	/* without RPS we can't safely check input_pkt_queue: during a
6004 	 * concurrent remote skb_queue_splice() we can detect as empty both
6005 	 * input_pkt_queue and process_queue even if the latter could end-up
6006 	 * containing a lot of packets.
6007 	 */
6008 	return true;
6009 }
6010 
6011 static void flush_all_backlogs(void)
6012 {
6013 	static cpumask_t flush_cpus;
6014 	unsigned int cpu;
6015 
6016 	/* since we are under rtnl lock protection we can use static data
6017 	 * for the cpumask and avoid allocating on stack the possibly
6018 	 * large mask
6019 	 */
6020 	ASSERT_RTNL();
6021 
6022 	cpus_read_lock();
6023 
6024 	cpumask_clear(&flush_cpus);
6025 	for_each_online_cpu(cpu) {
6026 		if (flush_required(cpu)) {
6027 			queue_work_on(cpu, system_highpri_wq,
6028 				      per_cpu_ptr(&flush_works, cpu));
6029 			cpumask_set_cpu(cpu, &flush_cpus);
6030 		}
6031 	}
6032 
6033 	/* we can have in flight packet[s] on the cpus we are not flushing,
6034 	 * synchronize_net() in unregister_netdevice_many() will take care of
6035 	 * them
6036 	 */
6037 	for_each_cpu(cpu, &flush_cpus)
6038 		flush_work(per_cpu_ptr(&flush_works, cpu));
6039 
6040 	cpus_read_unlock();
6041 }
6042 
6043 static void net_rps_send_ipi(struct softnet_data *remsd)
6044 {
6045 #ifdef CONFIG_RPS
6046 	while (remsd) {
6047 		struct softnet_data *next = remsd->rps_ipi_next;
6048 
6049 		if (cpu_online(remsd->cpu))
6050 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
6051 		remsd = next;
6052 	}
6053 #endif
6054 }
6055 
6056 /*
6057  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
6058  * Note: called with local irq disabled, but exits with local irq enabled.
6059  */
6060 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
6061 {
6062 #ifdef CONFIG_RPS
6063 	struct softnet_data *remsd = sd->rps_ipi_list;
6064 
6065 	if (!use_backlog_threads() && remsd) {
6066 		sd->rps_ipi_list = NULL;
6067 
6068 		local_irq_enable();
6069 
6070 		/* Send pending IPI's to kick RPS processing on remote cpus. */
6071 		net_rps_send_ipi(remsd);
6072 	} else
6073 #endif
6074 		local_irq_enable();
6075 }
6076 
6077 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
6078 {
6079 #ifdef CONFIG_RPS
6080 	return !use_backlog_threads() && sd->rps_ipi_list;
6081 #else
6082 	return false;
6083 #endif
6084 }
6085 
6086 static int process_backlog(struct napi_struct *napi, int quota)
6087 {
6088 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
6089 	bool again = true;
6090 	int work = 0;
6091 
6092 	/* Check if we have pending ipi, its better to send them now,
6093 	 * not waiting net_rx_action() end.
6094 	 */
6095 	if (sd_has_rps_ipi_waiting(sd)) {
6096 		local_irq_disable();
6097 		net_rps_action_and_irq_enable(sd);
6098 	}
6099 
6100 	napi->weight = READ_ONCE(net_hotdata.dev_rx_weight);
6101 	while (again) {
6102 		struct sk_buff *skb;
6103 
6104 		local_lock_nested_bh(&softnet_data.process_queue_bh_lock);
6105 		while ((skb = __skb_dequeue(&sd->process_queue))) {
6106 			local_unlock_nested_bh(&softnet_data.process_queue_bh_lock);
6107 			rcu_read_lock();
6108 			__netif_receive_skb(skb);
6109 			rcu_read_unlock();
6110 			if (++work >= quota) {
6111 				rps_input_queue_head_add(sd, work);
6112 				return work;
6113 			}
6114 
6115 			local_lock_nested_bh(&softnet_data.process_queue_bh_lock);
6116 		}
6117 		local_unlock_nested_bh(&softnet_data.process_queue_bh_lock);
6118 
6119 		backlog_lock_irq_disable(sd);
6120 		if (skb_queue_empty(&sd->input_pkt_queue)) {
6121 			/*
6122 			 * Inline a custom version of __napi_complete().
6123 			 * only current cpu owns and manipulates this napi,
6124 			 * and NAPI_STATE_SCHED is the only possible flag set
6125 			 * on backlog.
6126 			 * We can use a plain write instead of clear_bit(),
6127 			 * and we dont need an smp_mb() memory barrier.
6128 			 */
6129 			napi->state &= NAPIF_STATE_THREADED;
6130 			again = false;
6131 		} else {
6132 			local_lock_nested_bh(&softnet_data.process_queue_bh_lock);
6133 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
6134 						   &sd->process_queue);
6135 			local_unlock_nested_bh(&softnet_data.process_queue_bh_lock);
6136 		}
6137 		backlog_unlock_irq_enable(sd);
6138 	}
6139 
6140 	if (work)
6141 		rps_input_queue_head_add(sd, work);
6142 	return work;
6143 }
6144 
6145 /**
6146  * __napi_schedule - schedule for receive
6147  * @n: entry to schedule
6148  *
6149  * The entry's receive function will be scheduled to run.
6150  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
6151  */
6152 void __napi_schedule(struct napi_struct *n)
6153 {
6154 	unsigned long flags;
6155 
6156 	local_irq_save(flags);
6157 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
6158 	local_irq_restore(flags);
6159 }
6160 EXPORT_SYMBOL(__napi_schedule);
6161 
6162 /**
6163  *	napi_schedule_prep - check if napi can be scheduled
6164  *	@n: napi context
6165  *
6166  * Test if NAPI routine is already running, and if not mark
6167  * it as running.  This is used as a condition variable to
6168  * insure only one NAPI poll instance runs.  We also make
6169  * sure there is no pending NAPI disable.
6170  */
6171 bool napi_schedule_prep(struct napi_struct *n)
6172 {
6173 	unsigned long new, val = READ_ONCE(n->state);
6174 
6175 	do {
6176 		if (unlikely(val & NAPIF_STATE_DISABLE))
6177 			return false;
6178 		new = val | NAPIF_STATE_SCHED;
6179 
6180 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
6181 		 * This was suggested by Alexander Duyck, as compiler
6182 		 * emits better code than :
6183 		 * if (val & NAPIF_STATE_SCHED)
6184 		 *     new |= NAPIF_STATE_MISSED;
6185 		 */
6186 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6187 						   NAPIF_STATE_MISSED;
6188 	} while (!try_cmpxchg(&n->state, &val, new));
6189 
6190 	return !(val & NAPIF_STATE_SCHED);
6191 }
6192 EXPORT_SYMBOL(napi_schedule_prep);
6193 
6194 /**
6195  * __napi_schedule_irqoff - schedule for receive
6196  * @n: entry to schedule
6197  *
6198  * Variant of __napi_schedule() assuming hard irqs are masked.
6199  *
6200  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6201  * because the interrupt disabled assumption might not be true
6202  * due to force-threaded interrupts and spinlock substitution.
6203  */
6204 void __napi_schedule_irqoff(struct napi_struct *n)
6205 {
6206 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6207 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6208 	else
6209 		__napi_schedule(n);
6210 }
6211 EXPORT_SYMBOL(__napi_schedule_irqoff);
6212 
6213 bool napi_complete_done(struct napi_struct *n, int work_done)
6214 {
6215 	unsigned long flags, val, new, timeout = 0;
6216 	bool ret = true;
6217 
6218 	/*
6219 	 * 1) Don't let napi dequeue from the cpu poll list
6220 	 *    just in case its running on a different cpu.
6221 	 * 2) If we are busy polling, do nothing here, we have
6222 	 *    the guarantee we will be called later.
6223 	 */
6224 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6225 				 NAPIF_STATE_IN_BUSY_POLL)))
6226 		return false;
6227 
6228 	if (work_done) {
6229 		if (n->gro_bitmask)
6230 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6231 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6232 	}
6233 	if (n->defer_hard_irqs_count > 0) {
6234 		n->defer_hard_irqs_count--;
6235 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6236 		if (timeout)
6237 			ret = false;
6238 	}
6239 	if (n->gro_bitmask) {
6240 		/* When the NAPI instance uses a timeout and keeps postponing
6241 		 * it, we need to bound somehow the time packets are kept in
6242 		 * the GRO layer
6243 		 */
6244 		napi_gro_flush(n, !!timeout);
6245 	}
6246 
6247 	gro_normal_list(n);
6248 
6249 	if (unlikely(!list_empty(&n->poll_list))) {
6250 		/* If n->poll_list is not empty, we need to mask irqs */
6251 		local_irq_save(flags);
6252 		list_del_init(&n->poll_list);
6253 		local_irq_restore(flags);
6254 	}
6255 	WRITE_ONCE(n->list_owner, -1);
6256 
6257 	val = READ_ONCE(n->state);
6258 	do {
6259 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6260 
6261 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6262 			      NAPIF_STATE_SCHED_THREADED |
6263 			      NAPIF_STATE_PREFER_BUSY_POLL);
6264 
6265 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6266 		 * because we will call napi->poll() one more time.
6267 		 * This C code was suggested by Alexander Duyck to help gcc.
6268 		 */
6269 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6270 						    NAPIF_STATE_SCHED;
6271 	} while (!try_cmpxchg(&n->state, &val, new));
6272 
6273 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6274 		__napi_schedule(n);
6275 		return false;
6276 	}
6277 
6278 	if (timeout)
6279 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6280 			      HRTIMER_MODE_REL_PINNED);
6281 	return ret;
6282 }
6283 EXPORT_SYMBOL(napi_complete_done);
6284 
6285 /* must be called under rcu_read_lock(), as we dont take a reference */
6286 struct napi_struct *napi_by_id(unsigned int napi_id)
6287 {
6288 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6289 	struct napi_struct *napi;
6290 
6291 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6292 		if (napi->napi_id == napi_id)
6293 			return napi;
6294 
6295 	return NULL;
6296 }
6297 
6298 static void skb_defer_free_flush(struct softnet_data *sd)
6299 {
6300 	struct sk_buff *skb, *next;
6301 
6302 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6303 	if (!READ_ONCE(sd->defer_list))
6304 		return;
6305 
6306 	spin_lock(&sd->defer_lock);
6307 	skb = sd->defer_list;
6308 	sd->defer_list = NULL;
6309 	sd->defer_count = 0;
6310 	spin_unlock(&sd->defer_lock);
6311 
6312 	while (skb != NULL) {
6313 		next = skb->next;
6314 		napi_consume_skb(skb, 1);
6315 		skb = next;
6316 	}
6317 }
6318 
6319 #if defined(CONFIG_NET_RX_BUSY_POLL)
6320 
6321 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6322 {
6323 	if (!skip_schedule) {
6324 		gro_normal_list(napi);
6325 		__napi_schedule(napi);
6326 		return;
6327 	}
6328 
6329 	if (napi->gro_bitmask) {
6330 		/* flush too old packets
6331 		 * If HZ < 1000, flush all packets.
6332 		 */
6333 		napi_gro_flush(napi, HZ >= 1000);
6334 	}
6335 
6336 	gro_normal_list(napi);
6337 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6338 }
6339 
6340 enum {
6341 	NAPI_F_PREFER_BUSY_POLL	= 1,
6342 	NAPI_F_END_ON_RESCHED	= 2,
6343 };
6344 
6345 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
6346 			   unsigned flags, u16 budget)
6347 {
6348 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
6349 	bool skip_schedule = false;
6350 	unsigned long timeout;
6351 	int rc;
6352 
6353 	/* Busy polling means there is a high chance device driver hard irq
6354 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6355 	 * set in napi_schedule_prep().
6356 	 * Since we are about to call napi->poll() once more, we can safely
6357 	 * clear NAPI_STATE_MISSED.
6358 	 *
6359 	 * Note: x86 could use a single "lock and ..." instruction
6360 	 * to perform these two clear_bit()
6361 	 */
6362 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6363 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6364 
6365 	local_bh_disable();
6366 	bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
6367 
6368 	if (flags & NAPI_F_PREFER_BUSY_POLL) {
6369 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6370 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6371 		if (napi->defer_hard_irqs_count && timeout) {
6372 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6373 			skip_schedule = true;
6374 		}
6375 	}
6376 
6377 	/* All we really want here is to re-enable device interrupts.
6378 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6379 	 */
6380 	rc = napi->poll(napi, budget);
6381 	/* We can't gro_normal_list() here, because napi->poll() might have
6382 	 * rearmed the napi (napi_complete_done()) in which case it could
6383 	 * already be running on another CPU.
6384 	 */
6385 	trace_napi_poll(napi, rc, budget);
6386 	netpoll_poll_unlock(have_poll_lock);
6387 	if (rc == budget)
6388 		__busy_poll_stop(napi, skip_schedule);
6389 	bpf_net_ctx_clear(bpf_net_ctx);
6390 	local_bh_enable();
6391 }
6392 
6393 static void __napi_busy_loop(unsigned int napi_id,
6394 		      bool (*loop_end)(void *, unsigned long),
6395 		      void *loop_end_arg, unsigned flags, u16 budget)
6396 {
6397 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6398 	int (*napi_poll)(struct napi_struct *napi, int budget);
6399 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
6400 	void *have_poll_lock = NULL;
6401 	struct napi_struct *napi;
6402 
6403 	WARN_ON_ONCE(!rcu_read_lock_held());
6404 
6405 restart:
6406 	napi_poll = NULL;
6407 
6408 	napi = napi_by_id(napi_id);
6409 	if (!napi)
6410 		return;
6411 
6412 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6413 		preempt_disable();
6414 	for (;;) {
6415 		int work = 0;
6416 
6417 		local_bh_disable();
6418 		bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
6419 		if (!napi_poll) {
6420 			unsigned long val = READ_ONCE(napi->state);
6421 
6422 			/* If multiple threads are competing for this napi,
6423 			 * we avoid dirtying napi->state as much as we can.
6424 			 */
6425 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6426 				   NAPIF_STATE_IN_BUSY_POLL)) {
6427 				if (flags & NAPI_F_PREFER_BUSY_POLL)
6428 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6429 				goto count;
6430 			}
6431 			if (cmpxchg(&napi->state, val,
6432 				    val | NAPIF_STATE_IN_BUSY_POLL |
6433 					  NAPIF_STATE_SCHED) != val) {
6434 				if (flags & NAPI_F_PREFER_BUSY_POLL)
6435 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6436 				goto count;
6437 			}
6438 			have_poll_lock = netpoll_poll_lock(napi);
6439 			napi_poll = napi->poll;
6440 		}
6441 		work = napi_poll(napi, budget);
6442 		trace_napi_poll(napi, work, budget);
6443 		gro_normal_list(napi);
6444 count:
6445 		if (work > 0)
6446 			__NET_ADD_STATS(dev_net(napi->dev),
6447 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6448 		skb_defer_free_flush(this_cpu_ptr(&softnet_data));
6449 		bpf_net_ctx_clear(bpf_net_ctx);
6450 		local_bh_enable();
6451 
6452 		if (!loop_end || loop_end(loop_end_arg, start_time))
6453 			break;
6454 
6455 		if (unlikely(need_resched())) {
6456 			if (flags & NAPI_F_END_ON_RESCHED)
6457 				break;
6458 			if (napi_poll)
6459 				busy_poll_stop(napi, have_poll_lock, flags, budget);
6460 			if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6461 				preempt_enable();
6462 			rcu_read_unlock();
6463 			cond_resched();
6464 			rcu_read_lock();
6465 			if (loop_end(loop_end_arg, start_time))
6466 				return;
6467 			goto restart;
6468 		}
6469 		cpu_relax();
6470 	}
6471 	if (napi_poll)
6472 		busy_poll_stop(napi, have_poll_lock, flags, budget);
6473 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6474 		preempt_enable();
6475 }
6476 
6477 void napi_busy_loop_rcu(unsigned int napi_id,
6478 			bool (*loop_end)(void *, unsigned long),
6479 			void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6480 {
6481 	unsigned flags = NAPI_F_END_ON_RESCHED;
6482 
6483 	if (prefer_busy_poll)
6484 		flags |= NAPI_F_PREFER_BUSY_POLL;
6485 
6486 	__napi_busy_loop(napi_id, loop_end, loop_end_arg, flags, budget);
6487 }
6488 
6489 void napi_busy_loop(unsigned int napi_id,
6490 		    bool (*loop_end)(void *, unsigned long),
6491 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6492 {
6493 	unsigned flags = prefer_busy_poll ? NAPI_F_PREFER_BUSY_POLL : 0;
6494 
6495 	rcu_read_lock();
6496 	__napi_busy_loop(napi_id, loop_end, loop_end_arg, flags, budget);
6497 	rcu_read_unlock();
6498 }
6499 EXPORT_SYMBOL(napi_busy_loop);
6500 
6501 #endif /* CONFIG_NET_RX_BUSY_POLL */
6502 
6503 static void napi_hash_add(struct napi_struct *napi)
6504 {
6505 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6506 		return;
6507 
6508 	spin_lock(&napi_hash_lock);
6509 
6510 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6511 	do {
6512 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6513 			napi_gen_id = MIN_NAPI_ID;
6514 	} while (napi_by_id(napi_gen_id));
6515 	napi->napi_id = napi_gen_id;
6516 
6517 	hlist_add_head_rcu(&napi->napi_hash_node,
6518 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6519 
6520 	spin_unlock(&napi_hash_lock);
6521 }
6522 
6523 /* Warning : caller is responsible to make sure rcu grace period
6524  * is respected before freeing memory containing @napi
6525  */
6526 static void napi_hash_del(struct napi_struct *napi)
6527 {
6528 	spin_lock(&napi_hash_lock);
6529 
6530 	hlist_del_init_rcu(&napi->napi_hash_node);
6531 
6532 	spin_unlock(&napi_hash_lock);
6533 }
6534 
6535 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6536 {
6537 	struct napi_struct *napi;
6538 
6539 	napi = container_of(timer, struct napi_struct, timer);
6540 
6541 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6542 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6543 	 */
6544 	if (!napi_disable_pending(napi) &&
6545 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6546 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6547 		__napi_schedule_irqoff(napi);
6548 	}
6549 
6550 	return HRTIMER_NORESTART;
6551 }
6552 
6553 static void init_gro_hash(struct napi_struct *napi)
6554 {
6555 	int i;
6556 
6557 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6558 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6559 		napi->gro_hash[i].count = 0;
6560 	}
6561 	napi->gro_bitmask = 0;
6562 }
6563 
6564 int dev_set_threaded(struct net_device *dev, bool threaded)
6565 {
6566 	struct napi_struct *napi;
6567 	int err = 0;
6568 
6569 	if (dev->threaded == threaded)
6570 		return 0;
6571 
6572 	if (threaded) {
6573 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6574 			if (!napi->thread) {
6575 				err = napi_kthread_create(napi);
6576 				if (err) {
6577 					threaded = false;
6578 					break;
6579 				}
6580 			}
6581 		}
6582 	}
6583 
6584 	WRITE_ONCE(dev->threaded, threaded);
6585 
6586 	/* Make sure kthread is created before THREADED bit
6587 	 * is set.
6588 	 */
6589 	smp_mb__before_atomic();
6590 
6591 	/* Setting/unsetting threaded mode on a napi might not immediately
6592 	 * take effect, if the current napi instance is actively being
6593 	 * polled. In this case, the switch between threaded mode and
6594 	 * softirq mode will happen in the next round of napi_schedule().
6595 	 * This should not cause hiccups/stalls to the live traffic.
6596 	 */
6597 	list_for_each_entry(napi, &dev->napi_list, dev_list)
6598 		assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
6599 
6600 	return err;
6601 }
6602 EXPORT_SYMBOL(dev_set_threaded);
6603 
6604 /**
6605  * netif_queue_set_napi - Associate queue with the napi
6606  * @dev: device to which NAPI and queue belong
6607  * @queue_index: Index of queue
6608  * @type: queue type as RX or TX
6609  * @napi: NAPI context, pass NULL to clear previously set NAPI
6610  *
6611  * Set queue with its corresponding napi context. This should be done after
6612  * registering the NAPI handler for the queue-vector and the queues have been
6613  * mapped to the corresponding interrupt vector.
6614  */
6615 void netif_queue_set_napi(struct net_device *dev, unsigned int queue_index,
6616 			  enum netdev_queue_type type, struct napi_struct *napi)
6617 {
6618 	struct netdev_rx_queue *rxq;
6619 	struct netdev_queue *txq;
6620 
6621 	if (WARN_ON_ONCE(napi && !napi->dev))
6622 		return;
6623 	if (dev->reg_state >= NETREG_REGISTERED)
6624 		ASSERT_RTNL();
6625 
6626 	switch (type) {
6627 	case NETDEV_QUEUE_TYPE_RX:
6628 		rxq = __netif_get_rx_queue(dev, queue_index);
6629 		rxq->napi = napi;
6630 		return;
6631 	case NETDEV_QUEUE_TYPE_TX:
6632 		txq = netdev_get_tx_queue(dev, queue_index);
6633 		txq->napi = napi;
6634 		return;
6635 	default:
6636 		return;
6637 	}
6638 }
6639 EXPORT_SYMBOL(netif_queue_set_napi);
6640 
6641 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6642 			   int (*poll)(struct napi_struct *, int), int weight)
6643 {
6644 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6645 		return;
6646 
6647 	INIT_LIST_HEAD(&napi->poll_list);
6648 	INIT_HLIST_NODE(&napi->napi_hash_node);
6649 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6650 	napi->timer.function = napi_watchdog;
6651 	init_gro_hash(napi);
6652 	napi->skb = NULL;
6653 	INIT_LIST_HEAD(&napi->rx_list);
6654 	napi->rx_count = 0;
6655 	napi->poll = poll;
6656 	if (weight > NAPI_POLL_WEIGHT)
6657 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6658 				weight);
6659 	napi->weight = weight;
6660 	napi->dev = dev;
6661 #ifdef CONFIG_NETPOLL
6662 	napi->poll_owner = -1;
6663 #endif
6664 	napi->list_owner = -1;
6665 	set_bit(NAPI_STATE_SCHED, &napi->state);
6666 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6667 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6668 	napi_hash_add(napi);
6669 	napi_get_frags_check(napi);
6670 	/* Create kthread for this napi if dev->threaded is set.
6671 	 * Clear dev->threaded if kthread creation failed so that
6672 	 * threaded mode will not be enabled in napi_enable().
6673 	 */
6674 	if (dev->threaded && napi_kthread_create(napi))
6675 		dev->threaded = false;
6676 	netif_napi_set_irq(napi, -1);
6677 }
6678 EXPORT_SYMBOL(netif_napi_add_weight);
6679 
6680 void napi_disable(struct napi_struct *n)
6681 {
6682 	unsigned long val, new;
6683 
6684 	might_sleep();
6685 	set_bit(NAPI_STATE_DISABLE, &n->state);
6686 
6687 	val = READ_ONCE(n->state);
6688 	do {
6689 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6690 			usleep_range(20, 200);
6691 			val = READ_ONCE(n->state);
6692 		}
6693 
6694 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6695 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6696 	} while (!try_cmpxchg(&n->state, &val, new));
6697 
6698 	hrtimer_cancel(&n->timer);
6699 
6700 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6701 }
6702 EXPORT_SYMBOL(napi_disable);
6703 
6704 /**
6705  *	napi_enable - enable NAPI scheduling
6706  *	@n: NAPI context
6707  *
6708  * Resume NAPI from being scheduled on this context.
6709  * Must be paired with napi_disable.
6710  */
6711 void napi_enable(struct napi_struct *n)
6712 {
6713 	unsigned long new, val = READ_ONCE(n->state);
6714 
6715 	do {
6716 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6717 
6718 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6719 		if (n->dev->threaded && n->thread)
6720 			new |= NAPIF_STATE_THREADED;
6721 	} while (!try_cmpxchg(&n->state, &val, new));
6722 }
6723 EXPORT_SYMBOL(napi_enable);
6724 
6725 static void flush_gro_hash(struct napi_struct *napi)
6726 {
6727 	int i;
6728 
6729 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6730 		struct sk_buff *skb, *n;
6731 
6732 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6733 			kfree_skb(skb);
6734 		napi->gro_hash[i].count = 0;
6735 	}
6736 }
6737 
6738 /* Must be called in process context */
6739 void __netif_napi_del(struct napi_struct *napi)
6740 {
6741 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6742 		return;
6743 
6744 	napi_hash_del(napi);
6745 	list_del_rcu(&napi->dev_list);
6746 	napi_free_frags(napi);
6747 
6748 	flush_gro_hash(napi);
6749 	napi->gro_bitmask = 0;
6750 
6751 	if (napi->thread) {
6752 		kthread_stop(napi->thread);
6753 		napi->thread = NULL;
6754 	}
6755 }
6756 EXPORT_SYMBOL(__netif_napi_del);
6757 
6758 static int __napi_poll(struct napi_struct *n, bool *repoll)
6759 {
6760 	int work, weight;
6761 
6762 	weight = n->weight;
6763 
6764 	/* This NAPI_STATE_SCHED test is for avoiding a race
6765 	 * with netpoll's poll_napi().  Only the entity which
6766 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6767 	 * actually make the ->poll() call.  Therefore we avoid
6768 	 * accidentally calling ->poll() when NAPI is not scheduled.
6769 	 */
6770 	work = 0;
6771 	if (napi_is_scheduled(n)) {
6772 		work = n->poll(n, weight);
6773 		trace_napi_poll(n, work, weight);
6774 
6775 		xdp_do_check_flushed(n);
6776 	}
6777 
6778 	if (unlikely(work > weight))
6779 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6780 				n->poll, work, weight);
6781 
6782 	if (likely(work < weight))
6783 		return work;
6784 
6785 	/* Drivers must not modify the NAPI state if they
6786 	 * consume the entire weight.  In such cases this code
6787 	 * still "owns" the NAPI instance and therefore can
6788 	 * move the instance around on the list at-will.
6789 	 */
6790 	if (unlikely(napi_disable_pending(n))) {
6791 		napi_complete(n);
6792 		return work;
6793 	}
6794 
6795 	/* The NAPI context has more processing work, but busy-polling
6796 	 * is preferred. Exit early.
6797 	 */
6798 	if (napi_prefer_busy_poll(n)) {
6799 		if (napi_complete_done(n, work)) {
6800 			/* If timeout is not set, we need to make sure
6801 			 * that the NAPI is re-scheduled.
6802 			 */
6803 			napi_schedule(n);
6804 		}
6805 		return work;
6806 	}
6807 
6808 	if (n->gro_bitmask) {
6809 		/* flush too old packets
6810 		 * If HZ < 1000, flush all packets.
6811 		 */
6812 		napi_gro_flush(n, HZ >= 1000);
6813 	}
6814 
6815 	gro_normal_list(n);
6816 
6817 	/* Some drivers may have called napi_schedule
6818 	 * prior to exhausting their budget.
6819 	 */
6820 	if (unlikely(!list_empty(&n->poll_list))) {
6821 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6822 			     n->dev ? n->dev->name : "backlog");
6823 		return work;
6824 	}
6825 
6826 	*repoll = true;
6827 
6828 	return work;
6829 }
6830 
6831 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6832 {
6833 	bool do_repoll = false;
6834 	void *have;
6835 	int work;
6836 
6837 	list_del_init(&n->poll_list);
6838 
6839 	have = netpoll_poll_lock(n);
6840 
6841 	work = __napi_poll(n, &do_repoll);
6842 
6843 	if (do_repoll)
6844 		list_add_tail(&n->poll_list, repoll);
6845 
6846 	netpoll_poll_unlock(have);
6847 
6848 	return work;
6849 }
6850 
6851 static int napi_thread_wait(struct napi_struct *napi)
6852 {
6853 	set_current_state(TASK_INTERRUPTIBLE);
6854 
6855 	while (!kthread_should_stop()) {
6856 		/* Testing SCHED_THREADED bit here to make sure the current
6857 		 * kthread owns this napi and could poll on this napi.
6858 		 * Testing SCHED bit is not enough because SCHED bit might be
6859 		 * set by some other busy poll thread or by napi_disable().
6860 		 */
6861 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state)) {
6862 			WARN_ON(!list_empty(&napi->poll_list));
6863 			__set_current_state(TASK_RUNNING);
6864 			return 0;
6865 		}
6866 
6867 		schedule();
6868 		set_current_state(TASK_INTERRUPTIBLE);
6869 	}
6870 	__set_current_state(TASK_RUNNING);
6871 
6872 	return -1;
6873 }
6874 
6875 static void napi_threaded_poll_loop(struct napi_struct *napi)
6876 {
6877 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
6878 	struct softnet_data *sd;
6879 	unsigned long last_qs = jiffies;
6880 
6881 	for (;;) {
6882 		bool repoll = false;
6883 		void *have;
6884 
6885 		local_bh_disable();
6886 		bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
6887 
6888 		sd = this_cpu_ptr(&softnet_data);
6889 		sd->in_napi_threaded_poll = true;
6890 
6891 		have = netpoll_poll_lock(napi);
6892 		__napi_poll(napi, &repoll);
6893 		netpoll_poll_unlock(have);
6894 
6895 		sd->in_napi_threaded_poll = false;
6896 		barrier();
6897 
6898 		if (sd_has_rps_ipi_waiting(sd)) {
6899 			local_irq_disable();
6900 			net_rps_action_and_irq_enable(sd);
6901 		}
6902 		skb_defer_free_flush(sd);
6903 		bpf_net_ctx_clear(bpf_net_ctx);
6904 		local_bh_enable();
6905 
6906 		if (!repoll)
6907 			break;
6908 
6909 		rcu_softirq_qs_periodic(last_qs);
6910 		cond_resched();
6911 	}
6912 }
6913 
6914 static int napi_threaded_poll(void *data)
6915 {
6916 	struct napi_struct *napi = data;
6917 
6918 	while (!napi_thread_wait(napi))
6919 		napi_threaded_poll_loop(napi);
6920 
6921 	return 0;
6922 }
6923 
6924 static __latent_entropy void net_rx_action(struct softirq_action *h)
6925 {
6926 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6927 	unsigned long time_limit = jiffies +
6928 		usecs_to_jiffies(READ_ONCE(net_hotdata.netdev_budget_usecs));
6929 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
6930 	int budget = READ_ONCE(net_hotdata.netdev_budget);
6931 	LIST_HEAD(list);
6932 	LIST_HEAD(repoll);
6933 
6934 	bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
6935 start:
6936 	sd->in_net_rx_action = true;
6937 	local_irq_disable();
6938 	list_splice_init(&sd->poll_list, &list);
6939 	local_irq_enable();
6940 
6941 	for (;;) {
6942 		struct napi_struct *n;
6943 
6944 		skb_defer_free_flush(sd);
6945 
6946 		if (list_empty(&list)) {
6947 			if (list_empty(&repoll)) {
6948 				sd->in_net_rx_action = false;
6949 				barrier();
6950 				/* We need to check if ____napi_schedule()
6951 				 * had refilled poll_list while
6952 				 * sd->in_net_rx_action was true.
6953 				 */
6954 				if (!list_empty(&sd->poll_list))
6955 					goto start;
6956 				if (!sd_has_rps_ipi_waiting(sd))
6957 					goto end;
6958 			}
6959 			break;
6960 		}
6961 
6962 		n = list_first_entry(&list, struct napi_struct, poll_list);
6963 		budget -= napi_poll(n, &repoll);
6964 
6965 		/* If softirq window is exhausted then punt.
6966 		 * Allow this to run for 2 jiffies since which will allow
6967 		 * an average latency of 1.5/HZ.
6968 		 */
6969 		if (unlikely(budget <= 0 ||
6970 			     time_after_eq(jiffies, time_limit))) {
6971 			sd->time_squeeze++;
6972 			break;
6973 		}
6974 	}
6975 
6976 	local_irq_disable();
6977 
6978 	list_splice_tail_init(&sd->poll_list, &list);
6979 	list_splice_tail(&repoll, &list);
6980 	list_splice(&list, &sd->poll_list);
6981 	if (!list_empty(&sd->poll_list))
6982 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6983 	else
6984 		sd->in_net_rx_action = false;
6985 
6986 	net_rps_action_and_irq_enable(sd);
6987 end:
6988 	bpf_net_ctx_clear(bpf_net_ctx);
6989 }
6990 
6991 struct netdev_adjacent {
6992 	struct net_device *dev;
6993 	netdevice_tracker dev_tracker;
6994 
6995 	/* upper master flag, there can only be one master device per list */
6996 	bool master;
6997 
6998 	/* lookup ignore flag */
6999 	bool ignore;
7000 
7001 	/* counter for the number of times this device was added to us */
7002 	u16 ref_nr;
7003 
7004 	/* private field for the users */
7005 	void *private;
7006 
7007 	struct list_head list;
7008 	struct rcu_head rcu;
7009 };
7010 
7011 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
7012 						 struct list_head *adj_list)
7013 {
7014 	struct netdev_adjacent *adj;
7015 
7016 	list_for_each_entry(adj, adj_list, list) {
7017 		if (adj->dev == adj_dev)
7018 			return adj;
7019 	}
7020 	return NULL;
7021 }
7022 
7023 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
7024 				    struct netdev_nested_priv *priv)
7025 {
7026 	struct net_device *dev = (struct net_device *)priv->data;
7027 
7028 	return upper_dev == dev;
7029 }
7030 
7031 /**
7032  * netdev_has_upper_dev - Check if device is linked to an upper device
7033  * @dev: device
7034  * @upper_dev: upper device to check
7035  *
7036  * Find out if a device is linked to specified upper device and return true
7037  * in case it is. Note that this checks only immediate upper device,
7038  * not through a complete stack of devices. The caller must hold the RTNL lock.
7039  */
7040 bool netdev_has_upper_dev(struct net_device *dev,
7041 			  struct net_device *upper_dev)
7042 {
7043 	struct netdev_nested_priv priv = {
7044 		.data = (void *)upper_dev,
7045 	};
7046 
7047 	ASSERT_RTNL();
7048 
7049 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
7050 					     &priv);
7051 }
7052 EXPORT_SYMBOL(netdev_has_upper_dev);
7053 
7054 /**
7055  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
7056  * @dev: device
7057  * @upper_dev: upper device to check
7058  *
7059  * Find out if a device is linked to specified upper device and return true
7060  * in case it is. Note that this checks the entire upper device chain.
7061  * The caller must hold rcu lock.
7062  */
7063 
7064 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
7065 				  struct net_device *upper_dev)
7066 {
7067 	struct netdev_nested_priv priv = {
7068 		.data = (void *)upper_dev,
7069 	};
7070 
7071 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
7072 					       &priv);
7073 }
7074 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
7075 
7076 /**
7077  * netdev_has_any_upper_dev - Check if device is linked to some device
7078  * @dev: device
7079  *
7080  * Find out if a device is linked to an upper device and return true in case
7081  * it is. The caller must hold the RTNL lock.
7082  */
7083 bool netdev_has_any_upper_dev(struct net_device *dev)
7084 {
7085 	ASSERT_RTNL();
7086 
7087 	return !list_empty(&dev->adj_list.upper);
7088 }
7089 EXPORT_SYMBOL(netdev_has_any_upper_dev);
7090 
7091 /**
7092  * netdev_master_upper_dev_get - Get master upper device
7093  * @dev: device
7094  *
7095  * Find a master upper device and return pointer to it or NULL in case
7096  * it's not there. The caller must hold the RTNL lock.
7097  */
7098 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
7099 {
7100 	struct netdev_adjacent *upper;
7101 
7102 	ASSERT_RTNL();
7103 
7104 	if (list_empty(&dev->adj_list.upper))
7105 		return NULL;
7106 
7107 	upper = list_first_entry(&dev->adj_list.upper,
7108 				 struct netdev_adjacent, list);
7109 	if (likely(upper->master))
7110 		return upper->dev;
7111 	return NULL;
7112 }
7113 EXPORT_SYMBOL(netdev_master_upper_dev_get);
7114 
7115 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
7116 {
7117 	struct netdev_adjacent *upper;
7118 
7119 	ASSERT_RTNL();
7120 
7121 	if (list_empty(&dev->adj_list.upper))
7122 		return NULL;
7123 
7124 	upper = list_first_entry(&dev->adj_list.upper,
7125 				 struct netdev_adjacent, list);
7126 	if (likely(upper->master) && !upper->ignore)
7127 		return upper->dev;
7128 	return NULL;
7129 }
7130 
7131 /**
7132  * netdev_has_any_lower_dev - Check if device is linked to some device
7133  * @dev: device
7134  *
7135  * Find out if a device is linked to a lower device and return true in case
7136  * it is. The caller must hold the RTNL lock.
7137  */
7138 static bool netdev_has_any_lower_dev(struct net_device *dev)
7139 {
7140 	ASSERT_RTNL();
7141 
7142 	return !list_empty(&dev->adj_list.lower);
7143 }
7144 
7145 void *netdev_adjacent_get_private(struct list_head *adj_list)
7146 {
7147 	struct netdev_adjacent *adj;
7148 
7149 	adj = list_entry(adj_list, struct netdev_adjacent, list);
7150 
7151 	return adj->private;
7152 }
7153 EXPORT_SYMBOL(netdev_adjacent_get_private);
7154 
7155 /**
7156  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
7157  * @dev: device
7158  * @iter: list_head ** of the current position
7159  *
7160  * Gets the next device from the dev's upper list, starting from iter
7161  * position. The caller must hold RCU read lock.
7162  */
7163 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
7164 						 struct list_head **iter)
7165 {
7166 	struct netdev_adjacent *upper;
7167 
7168 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
7169 
7170 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7171 
7172 	if (&upper->list == &dev->adj_list.upper)
7173 		return NULL;
7174 
7175 	*iter = &upper->list;
7176 
7177 	return upper->dev;
7178 }
7179 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
7180 
7181 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
7182 						  struct list_head **iter,
7183 						  bool *ignore)
7184 {
7185 	struct netdev_adjacent *upper;
7186 
7187 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
7188 
7189 	if (&upper->list == &dev->adj_list.upper)
7190 		return NULL;
7191 
7192 	*iter = &upper->list;
7193 	*ignore = upper->ignore;
7194 
7195 	return upper->dev;
7196 }
7197 
7198 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
7199 						    struct list_head **iter)
7200 {
7201 	struct netdev_adjacent *upper;
7202 
7203 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
7204 
7205 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7206 
7207 	if (&upper->list == &dev->adj_list.upper)
7208 		return NULL;
7209 
7210 	*iter = &upper->list;
7211 
7212 	return upper->dev;
7213 }
7214 
7215 static int __netdev_walk_all_upper_dev(struct net_device *dev,
7216 				       int (*fn)(struct net_device *dev,
7217 					 struct netdev_nested_priv *priv),
7218 				       struct netdev_nested_priv *priv)
7219 {
7220 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7221 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7222 	int ret, cur = 0;
7223 	bool ignore;
7224 
7225 	now = dev;
7226 	iter = &dev->adj_list.upper;
7227 
7228 	while (1) {
7229 		if (now != dev) {
7230 			ret = fn(now, priv);
7231 			if (ret)
7232 				return ret;
7233 		}
7234 
7235 		next = NULL;
7236 		while (1) {
7237 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
7238 			if (!udev)
7239 				break;
7240 			if (ignore)
7241 				continue;
7242 
7243 			next = udev;
7244 			niter = &udev->adj_list.upper;
7245 			dev_stack[cur] = now;
7246 			iter_stack[cur++] = iter;
7247 			break;
7248 		}
7249 
7250 		if (!next) {
7251 			if (!cur)
7252 				return 0;
7253 			next = dev_stack[--cur];
7254 			niter = iter_stack[cur];
7255 		}
7256 
7257 		now = next;
7258 		iter = niter;
7259 	}
7260 
7261 	return 0;
7262 }
7263 
7264 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
7265 				  int (*fn)(struct net_device *dev,
7266 					    struct netdev_nested_priv *priv),
7267 				  struct netdev_nested_priv *priv)
7268 {
7269 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7270 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7271 	int ret, cur = 0;
7272 
7273 	now = dev;
7274 	iter = &dev->adj_list.upper;
7275 
7276 	while (1) {
7277 		if (now != dev) {
7278 			ret = fn(now, priv);
7279 			if (ret)
7280 				return ret;
7281 		}
7282 
7283 		next = NULL;
7284 		while (1) {
7285 			udev = netdev_next_upper_dev_rcu(now, &iter);
7286 			if (!udev)
7287 				break;
7288 
7289 			next = udev;
7290 			niter = &udev->adj_list.upper;
7291 			dev_stack[cur] = now;
7292 			iter_stack[cur++] = iter;
7293 			break;
7294 		}
7295 
7296 		if (!next) {
7297 			if (!cur)
7298 				return 0;
7299 			next = dev_stack[--cur];
7300 			niter = iter_stack[cur];
7301 		}
7302 
7303 		now = next;
7304 		iter = niter;
7305 	}
7306 
7307 	return 0;
7308 }
7309 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7310 
7311 static bool __netdev_has_upper_dev(struct net_device *dev,
7312 				   struct net_device *upper_dev)
7313 {
7314 	struct netdev_nested_priv priv = {
7315 		.flags = 0,
7316 		.data = (void *)upper_dev,
7317 	};
7318 
7319 	ASSERT_RTNL();
7320 
7321 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7322 					   &priv);
7323 }
7324 
7325 /**
7326  * netdev_lower_get_next_private - Get the next ->private from the
7327  *				   lower neighbour list
7328  * @dev: device
7329  * @iter: list_head ** of the current position
7330  *
7331  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7332  * list, starting from iter position. The caller must hold either hold the
7333  * RTNL lock or its own locking that guarantees that the neighbour lower
7334  * list will remain unchanged.
7335  */
7336 void *netdev_lower_get_next_private(struct net_device *dev,
7337 				    struct list_head **iter)
7338 {
7339 	struct netdev_adjacent *lower;
7340 
7341 	lower = list_entry(*iter, struct netdev_adjacent, list);
7342 
7343 	if (&lower->list == &dev->adj_list.lower)
7344 		return NULL;
7345 
7346 	*iter = lower->list.next;
7347 
7348 	return lower->private;
7349 }
7350 EXPORT_SYMBOL(netdev_lower_get_next_private);
7351 
7352 /**
7353  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7354  *				       lower neighbour list, RCU
7355  *				       variant
7356  * @dev: device
7357  * @iter: list_head ** of the current position
7358  *
7359  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7360  * list, starting from iter position. The caller must hold RCU read lock.
7361  */
7362 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7363 					struct list_head **iter)
7364 {
7365 	struct netdev_adjacent *lower;
7366 
7367 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7368 
7369 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7370 
7371 	if (&lower->list == &dev->adj_list.lower)
7372 		return NULL;
7373 
7374 	*iter = &lower->list;
7375 
7376 	return lower->private;
7377 }
7378 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7379 
7380 /**
7381  * netdev_lower_get_next - Get the next device from the lower neighbour
7382  *                         list
7383  * @dev: device
7384  * @iter: list_head ** of the current position
7385  *
7386  * Gets the next netdev_adjacent from the dev's lower neighbour
7387  * list, starting from iter position. The caller must hold RTNL lock or
7388  * its own locking that guarantees that the neighbour lower
7389  * list will remain unchanged.
7390  */
7391 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7392 {
7393 	struct netdev_adjacent *lower;
7394 
7395 	lower = list_entry(*iter, struct netdev_adjacent, list);
7396 
7397 	if (&lower->list == &dev->adj_list.lower)
7398 		return NULL;
7399 
7400 	*iter = lower->list.next;
7401 
7402 	return lower->dev;
7403 }
7404 EXPORT_SYMBOL(netdev_lower_get_next);
7405 
7406 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7407 						struct list_head **iter)
7408 {
7409 	struct netdev_adjacent *lower;
7410 
7411 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7412 
7413 	if (&lower->list == &dev->adj_list.lower)
7414 		return NULL;
7415 
7416 	*iter = &lower->list;
7417 
7418 	return lower->dev;
7419 }
7420 
7421 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7422 						  struct list_head **iter,
7423 						  bool *ignore)
7424 {
7425 	struct netdev_adjacent *lower;
7426 
7427 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7428 
7429 	if (&lower->list == &dev->adj_list.lower)
7430 		return NULL;
7431 
7432 	*iter = &lower->list;
7433 	*ignore = lower->ignore;
7434 
7435 	return lower->dev;
7436 }
7437 
7438 int netdev_walk_all_lower_dev(struct net_device *dev,
7439 			      int (*fn)(struct net_device *dev,
7440 					struct netdev_nested_priv *priv),
7441 			      struct netdev_nested_priv *priv)
7442 {
7443 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7444 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7445 	int ret, cur = 0;
7446 
7447 	now = dev;
7448 	iter = &dev->adj_list.lower;
7449 
7450 	while (1) {
7451 		if (now != dev) {
7452 			ret = fn(now, priv);
7453 			if (ret)
7454 				return ret;
7455 		}
7456 
7457 		next = NULL;
7458 		while (1) {
7459 			ldev = netdev_next_lower_dev(now, &iter);
7460 			if (!ldev)
7461 				break;
7462 
7463 			next = ldev;
7464 			niter = &ldev->adj_list.lower;
7465 			dev_stack[cur] = now;
7466 			iter_stack[cur++] = iter;
7467 			break;
7468 		}
7469 
7470 		if (!next) {
7471 			if (!cur)
7472 				return 0;
7473 			next = dev_stack[--cur];
7474 			niter = iter_stack[cur];
7475 		}
7476 
7477 		now = next;
7478 		iter = niter;
7479 	}
7480 
7481 	return 0;
7482 }
7483 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7484 
7485 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7486 				       int (*fn)(struct net_device *dev,
7487 					 struct netdev_nested_priv *priv),
7488 				       struct netdev_nested_priv *priv)
7489 {
7490 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7491 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7492 	int ret, cur = 0;
7493 	bool ignore;
7494 
7495 	now = dev;
7496 	iter = &dev->adj_list.lower;
7497 
7498 	while (1) {
7499 		if (now != dev) {
7500 			ret = fn(now, priv);
7501 			if (ret)
7502 				return ret;
7503 		}
7504 
7505 		next = NULL;
7506 		while (1) {
7507 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7508 			if (!ldev)
7509 				break;
7510 			if (ignore)
7511 				continue;
7512 
7513 			next = ldev;
7514 			niter = &ldev->adj_list.lower;
7515 			dev_stack[cur] = now;
7516 			iter_stack[cur++] = iter;
7517 			break;
7518 		}
7519 
7520 		if (!next) {
7521 			if (!cur)
7522 				return 0;
7523 			next = dev_stack[--cur];
7524 			niter = iter_stack[cur];
7525 		}
7526 
7527 		now = next;
7528 		iter = niter;
7529 	}
7530 
7531 	return 0;
7532 }
7533 
7534 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7535 					     struct list_head **iter)
7536 {
7537 	struct netdev_adjacent *lower;
7538 
7539 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7540 	if (&lower->list == &dev->adj_list.lower)
7541 		return NULL;
7542 
7543 	*iter = &lower->list;
7544 
7545 	return lower->dev;
7546 }
7547 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7548 
7549 static u8 __netdev_upper_depth(struct net_device *dev)
7550 {
7551 	struct net_device *udev;
7552 	struct list_head *iter;
7553 	u8 max_depth = 0;
7554 	bool ignore;
7555 
7556 	for (iter = &dev->adj_list.upper,
7557 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7558 	     udev;
7559 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7560 		if (ignore)
7561 			continue;
7562 		if (max_depth < udev->upper_level)
7563 			max_depth = udev->upper_level;
7564 	}
7565 
7566 	return max_depth;
7567 }
7568 
7569 static u8 __netdev_lower_depth(struct net_device *dev)
7570 {
7571 	struct net_device *ldev;
7572 	struct list_head *iter;
7573 	u8 max_depth = 0;
7574 	bool ignore;
7575 
7576 	for (iter = &dev->adj_list.lower,
7577 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7578 	     ldev;
7579 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7580 		if (ignore)
7581 			continue;
7582 		if (max_depth < ldev->lower_level)
7583 			max_depth = ldev->lower_level;
7584 	}
7585 
7586 	return max_depth;
7587 }
7588 
7589 static int __netdev_update_upper_level(struct net_device *dev,
7590 				       struct netdev_nested_priv *__unused)
7591 {
7592 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7593 	return 0;
7594 }
7595 
7596 #ifdef CONFIG_LOCKDEP
7597 static LIST_HEAD(net_unlink_list);
7598 
7599 static void net_unlink_todo(struct net_device *dev)
7600 {
7601 	if (list_empty(&dev->unlink_list))
7602 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7603 }
7604 #endif
7605 
7606 static int __netdev_update_lower_level(struct net_device *dev,
7607 				       struct netdev_nested_priv *priv)
7608 {
7609 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7610 
7611 #ifdef CONFIG_LOCKDEP
7612 	if (!priv)
7613 		return 0;
7614 
7615 	if (priv->flags & NESTED_SYNC_IMM)
7616 		dev->nested_level = dev->lower_level - 1;
7617 	if (priv->flags & NESTED_SYNC_TODO)
7618 		net_unlink_todo(dev);
7619 #endif
7620 	return 0;
7621 }
7622 
7623 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7624 				  int (*fn)(struct net_device *dev,
7625 					    struct netdev_nested_priv *priv),
7626 				  struct netdev_nested_priv *priv)
7627 {
7628 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7629 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7630 	int ret, cur = 0;
7631 
7632 	now = dev;
7633 	iter = &dev->adj_list.lower;
7634 
7635 	while (1) {
7636 		if (now != dev) {
7637 			ret = fn(now, priv);
7638 			if (ret)
7639 				return ret;
7640 		}
7641 
7642 		next = NULL;
7643 		while (1) {
7644 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7645 			if (!ldev)
7646 				break;
7647 
7648 			next = ldev;
7649 			niter = &ldev->adj_list.lower;
7650 			dev_stack[cur] = now;
7651 			iter_stack[cur++] = iter;
7652 			break;
7653 		}
7654 
7655 		if (!next) {
7656 			if (!cur)
7657 				return 0;
7658 			next = dev_stack[--cur];
7659 			niter = iter_stack[cur];
7660 		}
7661 
7662 		now = next;
7663 		iter = niter;
7664 	}
7665 
7666 	return 0;
7667 }
7668 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7669 
7670 /**
7671  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7672  *				       lower neighbour list, RCU
7673  *				       variant
7674  * @dev: device
7675  *
7676  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7677  * list. The caller must hold RCU read lock.
7678  */
7679 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7680 {
7681 	struct netdev_adjacent *lower;
7682 
7683 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7684 			struct netdev_adjacent, list);
7685 	if (lower)
7686 		return lower->private;
7687 	return NULL;
7688 }
7689 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7690 
7691 /**
7692  * netdev_master_upper_dev_get_rcu - Get master upper device
7693  * @dev: device
7694  *
7695  * Find a master upper device and return pointer to it or NULL in case
7696  * it's not there. The caller must hold the RCU read lock.
7697  */
7698 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7699 {
7700 	struct netdev_adjacent *upper;
7701 
7702 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7703 				       struct netdev_adjacent, list);
7704 	if (upper && likely(upper->master))
7705 		return upper->dev;
7706 	return NULL;
7707 }
7708 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7709 
7710 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7711 			      struct net_device *adj_dev,
7712 			      struct list_head *dev_list)
7713 {
7714 	char linkname[IFNAMSIZ+7];
7715 
7716 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7717 		"upper_%s" : "lower_%s", adj_dev->name);
7718 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7719 				 linkname);
7720 }
7721 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7722 			       char *name,
7723 			       struct list_head *dev_list)
7724 {
7725 	char linkname[IFNAMSIZ+7];
7726 
7727 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7728 		"upper_%s" : "lower_%s", name);
7729 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7730 }
7731 
7732 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7733 						 struct net_device *adj_dev,
7734 						 struct list_head *dev_list)
7735 {
7736 	return (dev_list == &dev->adj_list.upper ||
7737 		dev_list == &dev->adj_list.lower) &&
7738 		net_eq(dev_net(dev), dev_net(adj_dev));
7739 }
7740 
7741 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7742 					struct net_device *adj_dev,
7743 					struct list_head *dev_list,
7744 					void *private, bool master)
7745 {
7746 	struct netdev_adjacent *adj;
7747 	int ret;
7748 
7749 	adj = __netdev_find_adj(adj_dev, dev_list);
7750 
7751 	if (adj) {
7752 		adj->ref_nr += 1;
7753 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7754 			 dev->name, adj_dev->name, adj->ref_nr);
7755 
7756 		return 0;
7757 	}
7758 
7759 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7760 	if (!adj)
7761 		return -ENOMEM;
7762 
7763 	adj->dev = adj_dev;
7764 	adj->master = master;
7765 	adj->ref_nr = 1;
7766 	adj->private = private;
7767 	adj->ignore = false;
7768 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7769 
7770 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7771 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7772 
7773 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7774 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7775 		if (ret)
7776 			goto free_adj;
7777 	}
7778 
7779 	/* Ensure that master link is always the first item in list. */
7780 	if (master) {
7781 		ret = sysfs_create_link(&(dev->dev.kobj),
7782 					&(adj_dev->dev.kobj), "master");
7783 		if (ret)
7784 			goto remove_symlinks;
7785 
7786 		list_add_rcu(&adj->list, dev_list);
7787 	} else {
7788 		list_add_tail_rcu(&adj->list, dev_list);
7789 	}
7790 
7791 	return 0;
7792 
7793 remove_symlinks:
7794 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7795 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7796 free_adj:
7797 	netdev_put(adj_dev, &adj->dev_tracker);
7798 	kfree(adj);
7799 
7800 	return ret;
7801 }
7802 
7803 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7804 					 struct net_device *adj_dev,
7805 					 u16 ref_nr,
7806 					 struct list_head *dev_list)
7807 {
7808 	struct netdev_adjacent *adj;
7809 
7810 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7811 		 dev->name, adj_dev->name, ref_nr);
7812 
7813 	adj = __netdev_find_adj(adj_dev, dev_list);
7814 
7815 	if (!adj) {
7816 		pr_err("Adjacency does not exist for device %s from %s\n",
7817 		       dev->name, adj_dev->name);
7818 		WARN_ON(1);
7819 		return;
7820 	}
7821 
7822 	if (adj->ref_nr > ref_nr) {
7823 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7824 			 dev->name, adj_dev->name, ref_nr,
7825 			 adj->ref_nr - ref_nr);
7826 		adj->ref_nr -= ref_nr;
7827 		return;
7828 	}
7829 
7830 	if (adj->master)
7831 		sysfs_remove_link(&(dev->dev.kobj), "master");
7832 
7833 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7834 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7835 
7836 	list_del_rcu(&adj->list);
7837 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7838 		 adj_dev->name, dev->name, adj_dev->name);
7839 	netdev_put(adj_dev, &adj->dev_tracker);
7840 	kfree_rcu(adj, rcu);
7841 }
7842 
7843 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7844 					    struct net_device *upper_dev,
7845 					    struct list_head *up_list,
7846 					    struct list_head *down_list,
7847 					    void *private, bool master)
7848 {
7849 	int ret;
7850 
7851 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7852 					   private, master);
7853 	if (ret)
7854 		return ret;
7855 
7856 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7857 					   private, false);
7858 	if (ret) {
7859 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7860 		return ret;
7861 	}
7862 
7863 	return 0;
7864 }
7865 
7866 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7867 					       struct net_device *upper_dev,
7868 					       u16 ref_nr,
7869 					       struct list_head *up_list,
7870 					       struct list_head *down_list)
7871 {
7872 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7873 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7874 }
7875 
7876 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7877 						struct net_device *upper_dev,
7878 						void *private, bool master)
7879 {
7880 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7881 						&dev->adj_list.upper,
7882 						&upper_dev->adj_list.lower,
7883 						private, master);
7884 }
7885 
7886 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7887 						   struct net_device *upper_dev)
7888 {
7889 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7890 					   &dev->adj_list.upper,
7891 					   &upper_dev->adj_list.lower);
7892 }
7893 
7894 static int __netdev_upper_dev_link(struct net_device *dev,
7895 				   struct net_device *upper_dev, bool master,
7896 				   void *upper_priv, void *upper_info,
7897 				   struct netdev_nested_priv *priv,
7898 				   struct netlink_ext_ack *extack)
7899 {
7900 	struct netdev_notifier_changeupper_info changeupper_info = {
7901 		.info = {
7902 			.dev = dev,
7903 			.extack = extack,
7904 		},
7905 		.upper_dev = upper_dev,
7906 		.master = master,
7907 		.linking = true,
7908 		.upper_info = upper_info,
7909 	};
7910 	struct net_device *master_dev;
7911 	int ret = 0;
7912 
7913 	ASSERT_RTNL();
7914 
7915 	if (dev == upper_dev)
7916 		return -EBUSY;
7917 
7918 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7919 	if (__netdev_has_upper_dev(upper_dev, dev))
7920 		return -EBUSY;
7921 
7922 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7923 		return -EMLINK;
7924 
7925 	if (!master) {
7926 		if (__netdev_has_upper_dev(dev, upper_dev))
7927 			return -EEXIST;
7928 	} else {
7929 		master_dev = __netdev_master_upper_dev_get(dev);
7930 		if (master_dev)
7931 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7932 	}
7933 
7934 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7935 					    &changeupper_info.info);
7936 	ret = notifier_to_errno(ret);
7937 	if (ret)
7938 		return ret;
7939 
7940 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7941 						   master);
7942 	if (ret)
7943 		return ret;
7944 
7945 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7946 					    &changeupper_info.info);
7947 	ret = notifier_to_errno(ret);
7948 	if (ret)
7949 		goto rollback;
7950 
7951 	__netdev_update_upper_level(dev, NULL);
7952 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7953 
7954 	__netdev_update_lower_level(upper_dev, priv);
7955 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7956 				    priv);
7957 
7958 	return 0;
7959 
7960 rollback:
7961 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7962 
7963 	return ret;
7964 }
7965 
7966 /**
7967  * netdev_upper_dev_link - Add a link to the upper device
7968  * @dev: device
7969  * @upper_dev: new upper device
7970  * @extack: netlink extended ack
7971  *
7972  * Adds a link to device which is upper to this one. The caller must hold
7973  * the RTNL lock. On a failure a negative errno code is returned.
7974  * On success the reference counts are adjusted and the function
7975  * returns zero.
7976  */
7977 int netdev_upper_dev_link(struct net_device *dev,
7978 			  struct net_device *upper_dev,
7979 			  struct netlink_ext_ack *extack)
7980 {
7981 	struct netdev_nested_priv priv = {
7982 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7983 		.data = NULL,
7984 	};
7985 
7986 	return __netdev_upper_dev_link(dev, upper_dev, false,
7987 				       NULL, NULL, &priv, extack);
7988 }
7989 EXPORT_SYMBOL(netdev_upper_dev_link);
7990 
7991 /**
7992  * netdev_master_upper_dev_link - Add a master link to the upper device
7993  * @dev: device
7994  * @upper_dev: new upper device
7995  * @upper_priv: upper device private
7996  * @upper_info: upper info to be passed down via notifier
7997  * @extack: netlink extended ack
7998  *
7999  * Adds a link to device which is upper to this one. In this case, only
8000  * one master upper device can be linked, although other non-master devices
8001  * might be linked as well. The caller must hold the RTNL lock.
8002  * On a failure a negative errno code is returned. On success the reference
8003  * counts are adjusted and the function returns zero.
8004  */
8005 int netdev_master_upper_dev_link(struct net_device *dev,
8006 				 struct net_device *upper_dev,
8007 				 void *upper_priv, void *upper_info,
8008 				 struct netlink_ext_ack *extack)
8009 {
8010 	struct netdev_nested_priv priv = {
8011 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
8012 		.data = NULL,
8013 	};
8014 
8015 	return __netdev_upper_dev_link(dev, upper_dev, true,
8016 				       upper_priv, upper_info, &priv, extack);
8017 }
8018 EXPORT_SYMBOL(netdev_master_upper_dev_link);
8019 
8020 static void __netdev_upper_dev_unlink(struct net_device *dev,
8021 				      struct net_device *upper_dev,
8022 				      struct netdev_nested_priv *priv)
8023 {
8024 	struct netdev_notifier_changeupper_info changeupper_info = {
8025 		.info = {
8026 			.dev = dev,
8027 		},
8028 		.upper_dev = upper_dev,
8029 		.linking = false,
8030 	};
8031 
8032 	ASSERT_RTNL();
8033 
8034 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
8035 
8036 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
8037 				      &changeupper_info.info);
8038 
8039 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
8040 
8041 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
8042 				      &changeupper_info.info);
8043 
8044 	__netdev_update_upper_level(dev, NULL);
8045 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
8046 
8047 	__netdev_update_lower_level(upper_dev, priv);
8048 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
8049 				    priv);
8050 }
8051 
8052 /**
8053  * netdev_upper_dev_unlink - Removes a link to upper device
8054  * @dev: device
8055  * @upper_dev: new upper device
8056  *
8057  * Removes a link to device which is upper to this one. The caller must hold
8058  * the RTNL lock.
8059  */
8060 void netdev_upper_dev_unlink(struct net_device *dev,
8061 			     struct net_device *upper_dev)
8062 {
8063 	struct netdev_nested_priv priv = {
8064 		.flags = NESTED_SYNC_TODO,
8065 		.data = NULL,
8066 	};
8067 
8068 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
8069 }
8070 EXPORT_SYMBOL(netdev_upper_dev_unlink);
8071 
8072 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
8073 				      struct net_device *lower_dev,
8074 				      bool val)
8075 {
8076 	struct netdev_adjacent *adj;
8077 
8078 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
8079 	if (adj)
8080 		adj->ignore = val;
8081 
8082 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
8083 	if (adj)
8084 		adj->ignore = val;
8085 }
8086 
8087 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
8088 					struct net_device *lower_dev)
8089 {
8090 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
8091 }
8092 
8093 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
8094 				       struct net_device *lower_dev)
8095 {
8096 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
8097 }
8098 
8099 int netdev_adjacent_change_prepare(struct net_device *old_dev,
8100 				   struct net_device *new_dev,
8101 				   struct net_device *dev,
8102 				   struct netlink_ext_ack *extack)
8103 {
8104 	struct netdev_nested_priv priv = {
8105 		.flags = 0,
8106 		.data = NULL,
8107 	};
8108 	int err;
8109 
8110 	if (!new_dev)
8111 		return 0;
8112 
8113 	if (old_dev && new_dev != old_dev)
8114 		netdev_adjacent_dev_disable(dev, old_dev);
8115 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
8116 				      extack);
8117 	if (err) {
8118 		if (old_dev && new_dev != old_dev)
8119 			netdev_adjacent_dev_enable(dev, old_dev);
8120 		return err;
8121 	}
8122 
8123 	return 0;
8124 }
8125 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
8126 
8127 void netdev_adjacent_change_commit(struct net_device *old_dev,
8128 				   struct net_device *new_dev,
8129 				   struct net_device *dev)
8130 {
8131 	struct netdev_nested_priv priv = {
8132 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
8133 		.data = NULL,
8134 	};
8135 
8136 	if (!new_dev || !old_dev)
8137 		return;
8138 
8139 	if (new_dev == old_dev)
8140 		return;
8141 
8142 	netdev_adjacent_dev_enable(dev, old_dev);
8143 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
8144 }
8145 EXPORT_SYMBOL(netdev_adjacent_change_commit);
8146 
8147 void netdev_adjacent_change_abort(struct net_device *old_dev,
8148 				  struct net_device *new_dev,
8149 				  struct net_device *dev)
8150 {
8151 	struct netdev_nested_priv priv = {
8152 		.flags = 0,
8153 		.data = NULL,
8154 	};
8155 
8156 	if (!new_dev)
8157 		return;
8158 
8159 	if (old_dev && new_dev != old_dev)
8160 		netdev_adjacent_dev_enable(dev, old_dev);
8161 
8162 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
8163 }
8164 EXPORT_SYMBOL(netdev_adjacent_change_abort);
8165 
8166 /**
8167  * netdev_bonding_info_change - Dispatch event about slave change
8168  * @dev: device
8169  * @bonding_info: info to dispatch
8170  *
8171  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
8172  * The caller must hold the RTNL lock.
8173  */
8174 void netdev_bonding_info_change(struct net_device *dev,
8175 				struct netdev_bonding_info *bonding_info)
8176 {
8177 	struct netdev_notifier_bonding_info info = {
8178 		.info.dev = dev,
8179 	};
8180 
8181 	memcpy(&info.bonding_info, bonding_info,
8182 	       sizeof(struct netdev_bonding_info));
8183 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
8184 				      &info.info);
8185 }
8186 EXPORT_SYMBOL(netdev_bonding_info_change);
8187 
8188 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
8189 					   struct netlink_ext_ack *extack)
8190 {
8191 	struct netdev_notifier_offload_xstats_info info = {
8192 		.info.dev = dev,
8193 		.info.extack = extack,
8194 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
8195 	};
8196 	int err;
8197 	int rc;
8198 
8199 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
8200 					 GFP_KERNEL);
8201 	if (!dev->offload_xstats_l3)
8202 		return -ENOMEM;
8203 
8204 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
8205 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
8206 						  &info.info);
8207 	err = notifier_to_errno(rc);
8208 	if (err)
8209 		goto free_stats;
8210 
8211 	return 0;
8212 
8213 free_stats:
8214 	kfree(dev->offload_xstats_l3);
8215 	dev->offload_xstats_l3 = NULL;
8216 	return err;
8217 }
8218 
8219 int netdev_offload_xstats_enable(struct net_device *dev,
8220 				 enum netdev_offload_xstats_type type,
8221 				 struct netlink_ext_ack *extack)
8222 {
8223 	ASSERT_RTNL();
8224 
8225 	if (netdev_offload_xstats_enabled(dev, type))
8226 		return -EALREADY;
8227 
8228 	switch (type) {
8229 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8230 		return netdev_offload_xstats_enable_l3(dev, extack);
8231 	}
8232 
8233 	WARN_ON(1);
8234 	return -EINVAL;
8235 }
8236 EXPORT_SYMBOL(netdev_offload_xstats_enable);
8237 
8238 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
8239 {
8240 	struct netdev_notifier_offload_xstats_info info = {
8241 		.info.dev = dev,
8242 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
8243 	};
8244 
8245 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
8246 				      &info.info);
8247 	kfree(dev->offload_xstats_l3);
8248 	dev->offload_xstats_l3 = NULL;
8249 }
8250 
8251 int netdev_offload_xstats_disable(struct net_device *dev,
8252 				  enum netdev_offload_xstats_type type)
8253 {
8254 	ASSERT_RTNL();
8255 
8256 	if (!netdev_offload_xstats_enabled(dev, type))
8257 		return -EALREADY;
8258 
8259 	switch (type) {
8260 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8261 		netdev_offload_xstats_disable_l3(dev);
8262 		return 0;
8263 	}
8264 
8265 	WARN_ON(1);
8266 	return -EINVAL;
8267 }
8268 EXPORT_SYMBOL(netdev_offload_xstats_disable);
8269 
8270 static void netdev_offload_xstats_disable_all(struct net_device *dev)
8271 {
8272 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
8273 }
8274 
8275 static struct rtnl_hw_stats64 *
8276 netdev_offload_xstats_get_ptr(const struct net_device *dev,
8277 			      enum netdev_offload_xstats_type type)
8278 {
8279 	switch (type) {
8280 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8281 		return dev->offload_xstats_l3;
8282 	}
8283 
8284 	WARN_ON(1);
8285 	return NULL;
8286 }
8287 
8288 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8289 				   enum netdev_offload_xstats_type type)
8290 {
8291 	ASSERT_RTNL();
8292 
8293 	return netdev_offload_xstats_get_ptr(dev, type);
8294 }
8295 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8296 
8297 struct netdev_notifier_offload_xstats_ru {
8298 	bool used;
8299 };
8300 
8301 struct netdev_notifier_offload_xstats_rd {
8302 	struct rtnl_hw_stats64 stats;
8303 	bool used;
8304 };
8305 
8306 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8307 				  const struct rtnl_hw_stats64 *src)
8308 {
8309 	dest->rx_packets	  += src->rx_packets;
8310 	dest->tx_packets	  += src->tx_packets;
8311 	dest->rx_bytes		  += src->rx_bytes;
8312 	dest->tx_bytes		  += src->tx_bytes;
8313 	dest->rx_errors		  += src->rx_errors;
8314 	dest->tx_errors		  += src->tx_errors;
8315 	dest->rx_dropped	  += src->rx_dropped;
8316 	dest->tx_dropped	  += src->tx_dropped;
8317 	dest->multicast		  += src->multicast;
8318 }
8319 
8320 static int netdev_offload_xstats_get_used(struct net_device *dev,
8321 					  enum netdev_offload_xstats_type type,
8322 					  bool *p_used,
8323 					  struct netlink_ext_ack *extack)
8324 {
8325 	struct netdev_notifier_offload_xstats_ru report_used = {};
8326 	struct netdev_notifier_offload_xstats_info info = {
8327 		.info.dev = dev,
8328 		.info.extack = extack,
8329 		.type = type,
8330 		.report_used = &report_used,
8331 	};
8332 	int rc;
8333 
8334 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8335 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8336 					   &info.info);
8337 	*p_used = report_used.used;
8338 	return notifier_to_errno(rc);
8339 }
8340 
8341 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8342 					   enum netdev_offload_xstats_type type,
8343 					   struct rtnl_hw_stats64 *p_stats,
8344 					   bool *p_used,
8345 					   struct netlink_ext_ack *extack)
8346 {
8347 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8348 	struct netdev_notifier_offload_xstats_info info = {
8349 		.info.dev = dev,
8350 		.info.extack = extack,
8351 		.type = type,
8352 		.report_delta = &report_delta,
8353 	};
8354 	struct rtnl_hw_stats64 *stats;
8355 	int rc;
8356 
8357 	stats = netdev_offload_xstats_get_ptr(dev, type);
8358 	if (WARN_ON(!stats))
8359 		return -EINVAL;
8360 
8361 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8362 					   &info.info);
8363 
8364 	/* Cache whatever we got, even if there was an error, otherwise the
8365 	 * successful stats retrievals would get lost.
8366 	 */
8367 	netdev_hw_stats64_add(stats, &report_delta.stats);
8368 
8369 	if (p_stats)
8370 		*p_stats = *stats;
8371 	*p_used = report_delta.used;
8372 
8373 	return notifier_to_errno(rc);
8374 }
8375 
8376 int netdev_offload_xstats_get(struct net_device *dev,
8377 			      enum netdev_offload_xstats_type type,
8378 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8379 			      struct netlink_ext_ack *extack)
8380 {
8381 	ASSERT_RTNL();
8382 
8383 	if (p_stats)
8384 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8385 						       p_used, extack);
8386 	else
8387 		return netdev_offload_xstats_get_used(dev, type, p_used,
8388 						      extack);
8389 }
8390 EXPORT_SYMBOL(netdev_offload_xstats_get);
8391 
8392 void
8393 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8394 				   const struct rtnl_hw_stats64 *stats)
8395 {
8396 	report_delta->used = true;
8397 	netdev_hw_stats64_add(&report_delta->stats, stats);
8398 }
8399 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8400 
8401 void
8402 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8403 {
8404 	report_used->used = true;
8405 }
8406 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8407 
8408 void netdev_offload_xstats_push_delta(struct net_device *dev,
8409 				      enum netdev_offload_xstats_type type,
8410 				      const struct rtnl_hw_stats64 *p_stats)
8411 {
8412 	struct rtnl_hw_stats64 *stats;
8413 
8414 	ASSERT_RTNL();
8415 
8416 	stats = netdev_offload_xstats_get_ptr(dev, type);
8417 	if (WARN_ON(!stats))
8418 		return;
8419 
8420 	netdev_hw_stats64_add(stats, p_stats);
8421 }
8422 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8423 
8424 /**
8425  * netdev_get_xmit_slave - Get the xmit slave of master device
8426  * @dev: device
8427  * @skb: The packet
8428  * @all_slaves: assume all the slaves are active
8429  *
8430  * The reference counters are not incremented so the caller must be
8431  * careful with locks. The caller must hold RCU lock.
8432  * %NULL is returned if no slave is found.
8433  */
8434 
8435 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8436 					 struct sk_buff *skb,
8437 					 bool all_slaves)
8438 {
8439 	const struct net_device_ops *ops = dev->netdev_ops;
8440 
8441 	if (!ops->ndo_get_xmit_slave)
8442 		return NULL;
8443 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8444 }
8445 EXPORT_SYMBOL(netdev_get_xmit_slave);
8446 
8447 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8448 						  struct sock *sk)
8449 {
8450 	const struct net_device_ops *ops = dev->netdev_ops;
8451 
8452 	if (!ops->ndo_sk_get_lower_dev)
8453 		return NULL;
8454 	return ops->ndo_sk_get_lower_dev(dev, sk);
8455 }
8456 
8457 /**
8458  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8459  * @dev: device
8460  * @sk: the socket
8461  *
8462  * %NULL is returned if no lower device is found.
8463  */
8464 
8465 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8466 					    struct sock *sk)
8467 {
8468 	struct net_device *lower;
8469 
8470 	lower = netdev_sk_get_lower_dev(dev, sk);
8471 	while (lower) {
8472 		dev = lower;
8473 		lower = netdev_sk_get_lower_dev(dev, sk);
8474 	}
8475 
8476 	return dev;
8477 }
8478 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8479 
8480 static void netdev_adjacent_add_links(struct net_device *dev)
8481 {
8482 	struct netdev_adjacent *iter;
8483 
8484 	struct net *net = dev_net(dev);
8485 
8486 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8487 		if (!net_eq(net, dev_net(iter->dev)))
8488 			continue;
8489 		netdev_adjacent_sysfs_add(iter->dev, dev,
8490 					  &iter->dev->adj_list.lower);
8491 		netdev_adjacent_sysfs_add(dev, iter->dev,
8492 					  &dev->adj_list.upper);
8493 	}
8494 
8495 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8496 		if (!net_eq(net, dev_net(iter->dev)))
8497 			continue;
8498 		netdev_adjacent_sysfs_add(iter->dev, dev,
8499 					  &iter->dev->adj_list.upper);
8500 		netdev_adjacent_sysfs_add(dev, iter->dev,
8501 					  &dev->adj_list.lower);
8502 	}
8503 }
8504 
8505 static void netdev_adjacent_del_links(struct net_device *dev)
8506 {
8507 	struct netdev_adjacent *iter;
8508 
8509 	struct net *net = dev_net(dev);
8510 
8511 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8512 		if (!net_eq(net, dev_net(iter->dev)))
8513 			continue;
8514 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8515 					  &iter->dev->adj_list.lower);
8516 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8517 					  &dev->adj_list.upper);
8518 	}
8519 
8520 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8521 		if (!net_eq(net, dev_net(iter->dev)))
8522 			continue;
8523 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8524 					  &iter->dev->adj_list.upper);
8525 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8526 					  &dev->adj_list.lower);
8527 	}
8528 }
8529 
8530 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8531 {
8532 	struct netdev_adjacent *iter;
8533 
8534 	struct net *net = dev_net(dev);
8535 
8536 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8537 		if (!net_eq(net, dev_net(iter->dev)))
8538 			continue;
8539 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8540 					  &iter->dev->adj_list.lower);
8541 		netdev_adjacent_sysfs_add(iter->dev, dev,
8542 					  &iter->dev->adj_list.lower);
8543 	}
8544 
8545 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8546 		if (!net_eq(net, dev_net(iter->dev)))
8547 			continue;
8548 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8549 					  &iter->dev->adj_list.upper);
8550 		netdev_adjacent_sysfs_add(iter->dev, dev,
8551 					  &iter->dev->adj_list.upper);
8552 	}
8553 }
8554 
8555 void *netdev_lower_dev_get_private(struct net_device *dev,
8556 				   struct net_device *lower_dev)
8557 {
8558 	struct netdev_adjacent *lower;
8559 
8560 	if (!lower_dev)
8561 		return NULL;
8562 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8563 	if (!lower)
8564 		return NULL;
8565 
8566 	return lower->private;
8567 }
8568 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8569 
8570 
8571 /**
8572  * netdev_lower_state_changed - Dispatch event about lower device state change
8573  * @lower_dev: device
8574  * @lower_state_info: state to dispatch
8575  *
8576  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8577  * The caller must hold the RTNL lock.
8578  */
8579 void netdev_lower_state_changed(struct net_device *lower_dev,
8580 				void *lower_state_info)
8581 {
8582 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8583 		.info.dev = lower_dev,
8584 	};
8585 
8586 	ASSERT_RTNL();
8587 	changelowerstate_info.lower_state_info = lower_state_info;
8588 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8589 				      &changelowerstate_info.info);
8590 }
8591 EXPORT_SYMBOL(netdev_lower_state_changed);
8592 
8593 static void dev_change_rx_flags(struct net_device *dev, int flags)
8594 {
8595 	const struct net_device_ops *ops = dev->netdev_ops;
8596 
8597 	if (ops->ndo_change_rx_flags)
8598 		ops->ndo_change_rx_flags(dev, flags);
8599 }
8600 
8601 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8602 {
8603 	unsigned int old_flags = dev->flags;
8604 	unsigned int promiscuity, flags;
8605 	kuid_t uid;
8606 	kgid_t gid;
8607 
8608 	ASSERT_RTNL();
8609 
8610 	promiscuity = dev->promiscuity + inc;
8611 	if (promiscuity == 0) {
8612 		/*
8613 		 * Avoid overflow.
8614 		 * If inc causes overflow, untouch promisc and return error.
8615 		 */
8616 		if (unlikely(inc > 0)) {
8617 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8618 			return -EOVERFLOW;
8619 		}
8620 		flags = old_flags & ~IFF_PROMISC;
8621 	} else {
8622 		flags = old_flags | IFF_PROMISC;
8623 	}
8624 	WRITE_ONCE(dev->promiscuity, promiscuity);
8625 	if (flags != old_flags) {
8626 		WRITE_ONCE(dev->flags, flags);
8627 		netdev_info(dev, "%s promiscuous mode\n",
8628 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8629 		if (audit_enabled) {
8630 			current_uid_gid(&uid, &gid);
8631 			audit_log(audit_context(), GFP_ATOMIC,
8632 				  AUDIT_ANOM_PROMISCUOUS,
8633 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8634 				  dev->name, (dev->flags & IFF_PROMISC),
8635 				  (old_flags & IFF_PROMISC),
8636 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8637 				  from_kuid(&init_user_ns, uid),
8638 				  from_kgid(&init_user_ns, gid),
8639 				  audit_get_sessionid(current));
8640 		}
8641 
8642 		dev_change_rx_flags(dev, IFF_PROMISC);
8643 	}
8644 	if (notify)
8645 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8646 	return 0;
8647 }
8648 
8649 /**
8650  *	dev_set_promiscuity	- update promiscuity count on a device
8651  *	@dev: device
8652  *	@inc: modifier
8653  *
8654  *	Add or remove promiscuity from a device. While the count in the device
8655  *	remains above zero the interface remains promiscuous. Once it hits zero
8656  *	the device reverts back to normal filtering operation. A negative inc
8657  *	value is used to drop promiscuity on the device.
8658  *	Return 0 if successful or a negative errno code on error.
8659  */
8660 int dev_set_promiscuity(struct net_device *dev, int inc)
8661 {
8662 	unsigned int old_flags = dev->flags;
8663 	int err;
8664 
8665 	err = __dev_set_promiscuity(dev, inc, true);
8666 	if (err < 0)
8667 		return err;
8668 	if (dev->flags != old_flags)
8669 		dev_set_rx_mode(dev);
8670 	return err;
8671 }
8672 EXPORT_SYMBOL(dev_set_promiscuity);
8673 
8674 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8675 {
8676 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8677 	unsigned int allmulti, flags;
8678 
8679 	ASSERT_RTNL();
8680 
8681 	allmulti = dev->allmulti + inc;
8682 	if (allmulti == 0) {
8683 		/*
8684 		 * Avoid overflow.
8685 		 * If inc causes overflow, untouch allmulti and return error.
8686 		 */
8687 		if (unlikely(inc > 0)) {
8688 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8689 			return -EOVERFLOW;
8690 		}
8691 		flags = old_flags & ~IFF_ALLMULTI;
8692 	} else {
8693 		flags = old_flags | IFF_ALLMULTI;
8694 	}
8695 	WRITE_ONCE(dev->allmulti, allmulti);
8696 	if (flags != old_flags) {
8697 		WRITE_ONCE(dev->flags, flags);
8698 		netdev_info(dev, "%s allmulticast mode\n",
8699 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8700 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8701 		dev_set_rx_mode(dev);
8702 		if (notify)
8703 			__dev_notify_flags(dev, old_flags,
8704 					   dev->gflags ^ old_gflags, 0, NULL);
8705 	}
8706 	return 0;
8707 }
8708 
8709 /**
8710  *	dev_set_allmulti	- update allmulti count on a device
8711  *	@dev: device
8712  *	@inc: modifier
8713  *
8714  *	Add or remove reception of all multicast frames to a device. While the
8715  *	count in the device remains above zero the interface remains listening
8716  *	to all interfaces. Once it hits zero the device reverts back to normal
8717  *	filtering operation. A negative @inc value is used to drop the counter
8718  *	when releasing a resource needing all multicasts.
8719  *	Return 0 if successful or a negative errno code on error.
8720  */
8721 
8722 int dev_set_allmulti(struct net_device *dev, int inc)
8723 {
8724 	return __dev_set_allmulti(dev, inc, true);
8725 }
8726 EXPORT_SYMBOL(dev_set_allmulti);
8727 
8728 /*
8729  *	Upload unicast and multicast address lists to device and
8730  *	configure RX filtering. When the device doesn't support unicast
8731  *	filtering it is put in promiscuous mode while unicast addresses
8732  *	are present.
8733  */
8734 void __dev_set_rx_mode(struct net_device *dev)
8735 {
8736 	const struct net_device_ops *ops = dev->netdev_ops;
8737 
8738 	/* dev_open will call this function so the list will stay sane. */
8739 	if (!(dev->flags&IFF_UP))
8740 		return;
8741 
8742 	if (!netif_device_present(dev))
8743 		return;
8744 
8745 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8746 		/* Unicast addresses changes may only happen under the rtnl,
8747 		 * therefore calling __dev_set_promiscuity here is safe.
8748 		 */
8749 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8750 			__dev_set_promiscuity(dev, 1, false);
8751 			dev->uc_promisc = true;
8752 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8753 			__dev_set_promiscuity(dev, -1, false);
8754 			dev->uc_promisc = false;
8755 		}
8756 	}
8757 
8758 	if (ops->ndo_set_rx_mode)
8759 		ops->ndo_set_rx_mode(dev);
8760 }
8761 
8762 void dev_set_rx_mode(struct net_device *dev)
8763 {
8764 	netif_addr_lock_bh(dev);
8765 	__dev_set_rx_mode(dev);
8766 	netif_addr_unlock_bh(dev);
8767 }
8768 
8769 /**
8770  *	dev_get_flags - get flags reported to userspace
8771  *	@dev: device
8772  *
8773  *	Get the combination of flag bits exported through APIs to userspace.
8774  */
8775 unsigned int dev_get_flags(const struct net_device *dev)
8776 {
8777 	unsigned int flags;
8778 
8779 	flags = (READ_ONCE(dev->flags) & ~(IFF_PROMISC |
8780 				IFF_ALLMULTI |
8781 				IFF_RUNNING |
8782 				IFF_LOWER_UP |
8783 				IFF_DORMANT)) |
8784 		(READ_ONCE(dev->gflags) & (IFF_PROMISC |
8785 				IFF_ALLMULTI));
8786 
8787 	if (netif_running(dev)) {
8788 		if (netif_oper_up(dev))
8789 			flags |= IFF_RUNNING;
8790 		if (netif_carrier_ok(dev))
8791 			flags |= IFF_LOWER_UP;
8792 		if (netif_dormant(dev))
8793 			flags |= IFF_DORMANT;
8794 	}
8795 
8796 	return flags;
8797 }
8798 EXPORT_SYMBOL(dev_get_flags);
8799 
8800 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8801 		       struct netlink_ext_ack *extack)
8802 {
8803 	unsigned int old_flags = dev->flags;
8804 	int ret;
8805 
8806 	ASSERT_RTNL();
8807 
8808 	/*
8809 	 *	Set the flags on our device.
8810 	 */
8811 
8812 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8813 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8814 			       IFF_AUTOMEDIA)) |
8815 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8816 				    IFF_ALLMULTI));
8817 
8818 	/*
8819 	 *	Load in the correct multicast list now the flags have changed.
8820 	 */
8821 
8822 	if ((old_flags ^ flags) & IFF_MULTICAST)
8823 		dev_change_rx_flags(dev, IFF_MULTICAST);
8824 
8825 	dev_set_rx_mode(dev);
8826 
8827 	/*
8828 	 *	Have we downed the interface. We handle IFF_UP ourselves
8829 	 *	according to user attempts to set it, rather than blindly
8830 	 *	setting it.
8831 	 */
8832 
8833 	ret = 0;
8834 	if ((old_flags ^ flags) & IFF_UP) {
8835 		if (old_flags & IFF_UP)
8836 			__dev_close(dev);
8837 		else
8838 			ret = __dev_open(dev, extack);
8839 	}
8840 
8841 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8842 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8843 		unsigned int old_flags = dev->flags;
8844 
8845 		dev->gflags ^= IFF_PROMISC;
8846 
8847 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8848 			if (dev->flags != old_flags)
8849 				dev_set_rx_mode(dev);
8850 	}
8851 
8852 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8853 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8854 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8855 	 */
8856 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8857 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8858 
8859 		dev->gflags ^= IFF_ALLMULTI;
8860 		__dev_set_allmulti(dev, inc, false);
8861 	}
8862 
8863 	return ret;
8864 }
8865 
8866 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8867 			unsigned int gchanges, u32 portid,
8868 			const struct nlmsghdr *nlh)
8869 {
8870 	unsigned int changes = dev->flags ^ old_flags;
8871 
8872 	if (gchanges)
8873 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8874 
8875 	if (changes & IFF_UP) {
8876 		if (dev->flags & IFF_UP)
8877 			call_netdevice_notifiers(NETDEV_UP, dev);
8878 		else
8879 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8880 	}
8881 
8882 	if (dev->flags & IFF_UP &&
8883 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8884 		struct netdev_notifier_change_info change_info = {
8885 			.info = {
8886 				.dev = dev,
8887 			},
8888 			.flags_changed = changes,
8889 		};
8890 
8891 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8892 	}
8893 }
8894 
8895 /**
8896  *	dev_change_flags - change device settings
8897  *	@dev: device
8898  *	@flags: device state flags
8899  *	@extack: netlink extended ack
8900  *
8901  *	Change settings on device based state flags. The flags are
8902  *	in the userspace exported format.
8903  */
8904 int dev_change_flags(struct net_device *dev, unsigned int flags,
8905 		     struct netlink_ext_ack *extack)
8906 {
8907 	int ret;
8908 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8909 
8910 	ret = __dev_change_flags(dev, flags, extack);
8911 	if (ret < 0)
8912 		return ret;
8913 
8914 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8915 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8916 	return ret;
8917 }
8918 EXPORT_SYMBOL(dev_change_flags);
8919 
8920 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8921 {
8922 	const struct net_device_ops *ops = dev->netdev_ops;
8923 
8924 	if (ops->ndo_change_mtu)
8925 		return ops->ndo_change_mtu(dev, new_mtu);
8926 
8927 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8928 	WRITE_ONCE(dev->mtu, new_mtu);
8929 	return 0;
8930 }
8931 EXPORT_SYMBOL(__dev_set_mtu);
8932 
8933 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8934 		     struct netlink_ext_ack *extack)
8935 {
8936 	/* MTU must be positive, and in range */
8937 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8938 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8939 		return -EINVAL;
8940 	}
8941 
8942 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8943 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8944 		return -EINVAL;
8945 	}
8946 	return 0;
8947 }
8948 
8949 /**
8950  *	dev_set_mtu_ext - Change maximum transfer unit
8951  *	@dev: device
8952  *	@new_mtu: new transfer unit
8953  *	@extack: netlink extended ack
8954  *
8955  *	Change the maximum transfer size of the network device.
8956  */
8957 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8958 		    struct netlink_ext_ack *extack)
8959 {
8960 	int err, orig_mtu;
8961 
8962 	if (new_mtu == dev->mtu)
8963 		return 0;
8964 
8965 	err = dev_validate_mtu(dev, new_mtu, extack);
8966 	if (err)
8967 		return err;
8968 
8969 	if (!netif_device_present(dev))
8970 		return -ENODEV;
8971 
8972 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8973 	err = notifier_to_errno(err);
8974 	if (err)
8975 		return err;
8976 
8977 	orig_mtu = dev->mtu;
8978 	err = __dev_set_mtu(dev, new_mtu);
8979 
8980 	if (!err) {
8981 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8982 						   orig_mtu);
8983 		err = notifier_to_errno(err);
8984 		if (err) {
8985 			/* setting mtu back and notifying everyone again,
8986 			 * so that they have a chance to revert changes.
8987 			 */
8988 			__dev_set_mtu(dev, orig_mtu);
8989 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8990 						     new_mtu);
8991 		}
8992 	}
8993 	return err;
8994 }
8995 
8996 int dev_set_mtu(struct net_device *dev, int new_mtu)
8997 {
8998 	struct netlink_ext_ack extack;
8999 	int err;
9000 
9001 	memset(&extack, 0, sizeof(extack));
9002 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
9003 	if (err && extack._msg)
9004 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
9005 	return err;
9006 }
9007 EXPORT_SYMBOL(dev_set_mtu);
9008 
9009 /**
9010  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
9011  *	@dev: device
9012  *	@new_len: new tx queue length
9013  */
9014 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
9015 {
9016 	unsigned int orig_len = dev->tx_queue_len;
9017 	int res;
9018 
9019 	if (new_len != (unsigned int)new_len)
9020 		return -ERANGE;
9021 
9022 	if (new_len != orig_len) {
9023 		WRITE_ONCE(dev->tx_queue_len, new_len);
9024 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
9025 		res = notifier_to_errno(res);
9026 		if (res)
9027 			goto err_rollback;
9028 		res = dev_qdisc_change_tx_queue_len(dev);
9029 		if (res)
9030 			goto err_rollback;
9031 	}
9032 
9033 	return 0;
9034 
9035 err_rollback:
9036 	netdev_err(dev, "refused to change device tx_queue_len\n");
9037 	WRITE_ONCE(dev->tx_queue_len, orig_len);
9038 	return res;
9039 }
9040 
9041 /**
9042  *	dev_set_group - Change group this device belongs to
9043  *	@dev: device
9044  *	@new_group: group this device should belong to
9045  */
9046 void dev_set_group(struct net_device *dev, int new_group)
9047 {
9048 	dev->group = new_group;
9049 }
9050 
9051 /**
9052  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
9053  *	@dev: device
9054  *	@addr: new address
9055  *	@extack: netlink extended ack
9056  */
9057 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
9058 			      struct netlink_ext_ack *extack)
9059 {
9060 	struct netdev_notifier_pre_changeaddr_info info = {
9061 		.info.dev = dev,
9062 		.info.extack = extack,
9063 		.dev_addr = addr,
9064 	};
9065 	int rc;
9066 
9067 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
9068 	return notifier_to_errno(rc);
9069 }
9070 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
9071 
9072 /**
9073  *	dev_set_mac_address - Change Media Access Control Address
9074  *	@dev: device
9075  *	@sa: new address
9076  *	@extack: netlink extended ack
9077  *
9078  *	Change the hardware (MAC) address of the device
9079  */
9080 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
9081 			struct netlink_ext_ack *extack)
9082 {
9083 	const struct net_device_ops *ops = dev->netdev_ops;
9084 	int err;
9085 
9086 	if (!ops->ndo_set_mac_address)
9087 		return -EOPNOTSUPP;
9088 	if (sa->sa_family != dev->type)
9089 		return -EINVAL;
9090 	if (!netif_device_present(dev))
9091 		return -ENODEV;
9092 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
9093 	if (err)
9094 		return err;
9095 	if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
9096 		err = ops->ndo_set_mac_address(dev, sa);
9097 		if (err)
9098 			return err;
9099 	}
9100 	dev->addr_assign_type = NET_ADDR_SET;
9101 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
9102 	add_device_randomness(dev->dev_addr, dev->addr_len);
9103 	return 0;
9104 }
9105 EXPORT_SYMBOL(dev_set_mac_address);
9106 
9107 DECLARE_RWSEM(dev_addr_sem);
9108 
9109 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
9110 			     struct netlink_ext_ack *extack)
9111 {
9112 	int ret;
9113 
9114 	down_write(&dev_addr_sem);
9115 	ret = dev_set_mac_address(dev, sa, extack);
9116 	up_write(&dev_addr_sem);
9117 	return ret;
9118 }
9119 EXPORT_SYMBOL(dev_set_mac_address_user);
9120 
9121 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
9122 {
9123 	size_t size = sizeof(sa->sa_data_min);
9124 	struct net_device *dev;
9125 	int ret = 0;
9126 
9127 	down_read(&dev_addr_sem);
9128 	rcu_read_lock();
9129 
9130 	dev = dev_get_by_name_rcu(net, dev_name);
9131 	if (!dev) {
9132 		ret = -ENODEV;
9133 		goto unlock;
9134 	}
9135 	if (!dev->addr_len)
9136 		memset(sa->sa_data, 0, size);
9137 	else
9138 		memcpy(sa->sa_data, dev->dev_addr,
9139 		       min_t(size_t, size, dev->addr_len));
9140 	sa->sa_family = dev->type;
9141 
9142 unlock:
9143 	rcu_read_unlock();
9144 	up_read(&dev_addr_sem);
9145 	return ret;
9146 }
9147 EXPORT_SYMBOL(dev_get_mac_address);
9148 
9149 /**
9150  *	dev_change_carrier - Change device carrier
9151  *	@dev: device
9152  *	@new_carrier: new value
9153  *
9154  *	Change device carrier
9155  */
9156 int dev_change_carrier(struct net_device *dev, bool new_carrier)
9157 {
9158 	const struct net_device_ops *ops = dev->netdev_ops;
9159 
9160 	if (!ops->ndo_change_carrier)
9161 		return -EOPNOTSUPP;
9162 	if (!netif_device_present(dev))
9163 		return -ENODEV;
9164 	return ops->ndo_change_carrier(dev, new_carrier);
9165 }
9166 
9167 /**
9168  *	dev_get_phys_port_id - Get device physical port ID
9169  *	@dev: device
9170  *	@ppid: port ID
9171  *
9172  *	Get device physical port ID
9173  */
9174 int dev_get_phys_port_id(struct net_device *dev,
9175 			 struct netdev_phys_item_id *ppid)
9176 {
9177 	const struct net_device_ops *ops = dev->netdev_ops;
9178 
9179 	if (!ops->ndo_get_phys_port_id)
9180 		return -EOPNOTSUPP;
9181 	return ops->ndo_get_phys_port_id(dev, ppid);
9182 }
9183 
9184 /**
9185  *	dev_get_phys_port_name - Get device physical port name
9186  *	@dev: device
9187  *	@name: port name
9188  *	@len: limit of bytes to copy to name
9189  *
9190  *	Get device physical port name
9191  */
9192 int dev_get_phys_port_name(struct net_device *dev,
9193 			   char *name, size_t len)
9194 {
9195 	const struct net_device_ops *ops = dev->netdev_ops;
9196 	int err;
9197 
9198 	if (ops->ndo_get_phys_port_name) {
9199 		err = ops->ndo_get_phys_port_name(dev, name, len);
9200 		if (err != -EOPNOTSUPP)
9201 			return err;
9202 	}
9203 	return devlink_compat_phys_port_name_get(dev, name, len);
9204 }
9205 
9206 /**
9207  *	dev_get_port_parent_id - Get the device's port parent identifier
9208  *	@dev: network device
9209  *	@ppid: pointer to a storage for the port's parent identifier
9210  *	@recurse: allow/disallow recursion to lower devices
9211  *
9212  *	Get the devices's port parent identifier
9213  */
9214 int dev_get_port_parent_id(struct net_device *dev,
9215 			   struct netdev_phys_item_id *ppid,
9216 			   bool recurse)
9217 {
9218 	const struct net_device_ops *ops = dev->netdev_ops;
9219 	struct netdev_phys_item_id first = { };
9220 	struct net_device *lower_dev;
9221 	struct list_head *iter;
9222 	int err;
9223 
9224 	if (ops->ndo_get_port_parent_id) {
9225 		err = ops->ndo_get_port_parent_id(dev, ppid);
9226 		if (err != -EOPNOTSUPP)
9227 			return err;
9228 	}
9229 
9230 	err = devlink_compat_switch_id_get(dev, ppid);
9231 	if (!recurse || err != -EOPNOTSUPP)
9232 		return err;
9233 
9234 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
9235 		err = dev_get_port_parent_id(lower_dev, ppid, true);
9236 		if (err)
9237 			break;
9238 		if (!first.id_len)
9239 			first = *ppid;
9240 		else if (memcmp(&first, ppid, sizeof(*ppid)))
9241 			return -EOPNOTSUPP;
9242 	}
9243 
9244 	return err;
9245 }
9246 EXPORT_SYMBOL(dev_get_port_parent_id);
9247 
9248 /**
9249  *	netdev_port_same_parent_id - Indicate if two network devices have
9250  *	the same port parent identifier
9251  *	@a: first network device
9252  *	@b: second network device
9253  */
9254 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
9255 {
9256 	struct netdev_phys_item_id a_id = { };
9257 	struct netdev_phys_item_id b_id = { };
9258 
9259 	if (dev_get_port_parent_id(a, &a_id, true) ||
9260 	    dev_get_port_parent_id(b, &b_id, true))
9261 		return false;
9262 
9263 	return netdev_phys_item_id_same(&a_id, &b_id);
9264 }
9265 EXPORT_SYMBOL(netdev_port_same_parent_id);
9266 
9267 /**
9268  *	dev_change_proto_down - set carrier according to proto_down.
9269  *
9270  *	@dev: device
9271  *	@proto_down: new value
9272  */
9273 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9274 {
9275 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
9276 		return -EOPNOTSUPP;
9277 	if (!netif_device_present(dev))
9278 		return -ENODEV;
9279 	if (proto_down)
9280 		netif_carrier_off(dev);
9281 	else
9282 		netif_carrier_on(dev);
9283 	WRITE_ONCE(dev->proto_down, proto_down);
9284 	return 0;
9285 }
9286 
9287 /**
9288  *	dev_change_proto_down_reason - proto down reason
9289  *
9290  *	@dev: device
9291  *	@mask: proto down mask
9292  *	@value: proto down value
9293  */
9294 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9295 				  u32 value)
9296 {
9297 	u32 proto_down_reason;
9298 	int b;
9299 
9300 	if (!mask) {
9301 		proto_down_reason = value;
9302 	} else {
9303 		proto_down_reason = dev->proto_down_reason;
9304 		for_each_set_bit(b, &mask, 32) {
9305 			if (value & (1 << b))
9306 				proto_down_reason |= BIT(b);
9307 			else
9308 				proto_down_reason &= ~BIT(b);
9309 		}
9310 	}
9311 	WRITE_ONCE(dev->proto_down_reason, proto_down_reason);
9312 }
9313 
9314 struct bpf_xdp_link {
9315 	struct bpf_link link;
9316 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9317 	int flags;
9318 };
9319 
9320 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9321 {
9322 	if (flags & XDP_FLAGS_HW_MODE)
9323 		return XDP_MODE_HW;
9324 	if (flags & XDP_FLAGS_DRV_MODE)
9325 		return XDP_MODE_DRV;
9326 	if (flags & XDP_FLAGS_SKB_MODE)
9327 		return XDP_MODE_SKB;
9328 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9329 }
9330 
9331 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9332 {
9333 	switch (mode) {
9334 	case XDP_MODE_SKB:
9335 		return generic_xdp_install;
9336 	case XDP_MODE_DRV:
9337 	case XDP_MODE_HW:
9338 		return dev->netdev_ops->ndo_bpf;
9339 	default:
9340 		return NULL;
9341 	}
9342 }
9343 
9344 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9345 					 enum bpf_xdp_mode mode)
9346 {
9347 	return dev->xdp_state[mode].link;
9348 }
9349 
9350 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9351 				     enum bpf_xdp_mode mode)
9352 {
9353 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9354 
9355 	if (link)
9356 		return link->link.prog;
9357 	return dev->xdp_state[mode].prog;
9358 }
9359 
9360 u8 dev_xdp_prog_count(struct net_device *dev)
9361 {
9362 	u8 count = 0;
9363 	int i;
9364 
9365 	for (i = 0; i < __MAX_XDP_MODE; i++)
9366 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9367 			count++;
9368 	return count;
9369 }
9370 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9371 
9372 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9373 {
9374 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9375 
9376 	return prog ? prog->aux->id : 0;
9377 }
9378 
9379 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9380 			     struct bpf_xdp_link *link)
9381 {
9382 	dev->xdp_state[mode].link = link;
9383 	dev->xdp_state[mode].prog = NULL;
9384 }
9385 
9386 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9387 			     struct bpf_prog *prog)
9388 {
9389 	dev->xdp_state[mode].link = NULL;
9390 	dev->xdp_state[mode].prog = prog;
9391 }
9392 
9393 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9394 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9395 			   u32 flags, struct bpf_prog *prog)
9396 {
9397 	struct netdev_bpf xdp;
9398 	int err;
9399 
9400 	memset(&xdp, 0, sizeof(xdp));
9401 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9402 	xdp.extack = extack;
9403 	xdp.flags = flags;
9404 	xdp.prog = prog;
9405 
9406 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9407 	 * "moved" into driver), so they don't increment it on their own, but
9408 	 * they do decrement refcnt when program is detached or replaced.
9409 	 * Given net_device also owns link/prog, we need to bump refcnt here
9410 	 * to prevent drivers from underflowing it.
9411 	 */
9412 	if (prog)
9413 		bpf_prog_inc(prog);
9414 	err = bpf_op(dev, &xdp);
9415 	if (err) {
9416 		if (prog)
9417 			bpf_prog_put(prog);
9418 		return err;
9419 	}
9420 
9421 	if (mode != XDP_MODE_HW)
9422 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9423 
9424 	return 0;
9425 }
9426 
9427 static void dev_xdp_uninstall(struct net_device *dev)
9428 {
9429 	struct bpf_xdp_link *link;
9430 	struct bpf_prog *prog;
9431 	enum bpf_xdp_mode mode;
9432 	bpf_op_t bpf_op;
9433 
9434 	ASSERT_RTNL();
9435 
9436 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9437 		prog = dev_xdp_prog(dev, mode);
9438 		if (!prog)
9439 			continue;
9440 
9441 		bpf_op = dev_xdp_bpf_op(dev, mode);
9442 		if (!bpf_op)
9443 			continue;
9444 
9445 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9446 
9447 		/* auto-detach link from net device */
9448 		link = dev_xdp_link(dev, mode);
9449 		if (link)
9450 			link->dev = NULL;
9451 		else
9452 			bpf_prog_put(prog);
9453 
9454 		dev_xdp_set_link(dev, mode, NULL);
9455 	}
9456 }
9457 
9458 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9459 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9460 			  struct bpf_prog *old_prog, u32 flags)
9461 {
9462 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9463 	struct bpf_prog *cur_prog;
9464 	struct net_device *upper;
9465 	struct list_head *iter;
9466 	enum bpf_xdp_mode mode;
9467 	bpf_op_t bpf_op;
9468 	int err;
9469 
9470 	ASSERT_RTNL();
9471 
9472 	/* either link or prog attachment, never both */
9473 	if (link && (new_prog || old_prog))
9474 		return -EINVAL;
9475 	/* link supports only XDP mode flags */
9476 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9477 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9478 		return -EINVAL;
9479 	}
9480 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9481 	if (num_modes > 1) {
9482 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9483 		return -EINVAL;
9484 	}
9485 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9486 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9487 		NL_SET_ERR_MSG(extack,
9488 			       "More than one program loaded, unset mode is ambiguous");
9489 		return -EINVAL;
9490 	}
9491 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9492 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9493 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9494 		return -EINVAL;
9495 	}
9496 
9497 	mode = dev_xdp_mode(dev, flags);
9498 	/* can't replace attached link */
9499 	if (dev_xdp_link(dev, mode)) {
9500 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9501 		return -EBUSY;
9502 	}
9503 
9504 	/* don't allow if an upper device already has a program */
9505 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9506 		if (dev_xdp_prog_count(upper) > 0) {
9507 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9508 			return -EEXIST;
9509 		}
9510 	}
9511 
9512 	cur_prog = dev_xdp_prog(dev, mode);
9513 	/* can't replace attached prog with link */
9514 	if (link && cur_prog) {
9515 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9516 		return -EBUSY;
9517 	}
9518 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9519 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9520 		return -EEXIST;
9521 	}
9522 
9523 	/* put effective new program into new_prog */
9524 	if (link)
9525 		new_prog = link->link.prog;
9526 
9527 	if (new_prog) {
9528 		bool offload = mode == XDP_MODE_HW;
9529 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9530 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9531 
9532 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9533 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9534 			return -EBUSY;
9535 		}
9536 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9537 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9538 			return -EEXIST;
9539 		}
9540 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9541 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9542 			return -EINVAL;
9543 		}
9544 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9545 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9546 			return -EINVAL;
9547 		}
9548 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9549 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9550 			return -EINVAL;
9551 		}
9552 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9553 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9554 			return -EINVAL;
9555 		}
9556 	}
9557 
9558 	/* don't call drivers if the effective program didn't change */
9559 	if (new_prog != cur_prog) {
9560 		bpf_op = dev_xdp_bpf_op(dev, mode);
9561 		if (!bpf_op) {
9562 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9563 			return -EOPNOTSUPP;
9564 		}
9565 
9566 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9567 		if (err)
9568 			return err;
9569 	}
9570 
9571 	if (link)
9572 		dev_xdp_set_link(dev, mode, link);
9573 	else
9574 		dev_xdp_set_prog(dev, mode, new_prog);
9575 	if (cur_prog)
9576 		bpf_prog_put(cur_prog);
9577 
9578 	return 0;
9579 }
9580 
9581 static int dev_xdp_attach_link(struct net_device *dev,
9582 			       struct netlink_ext_ack *extack,
9583 			       struct bpf_xdp_link *link)
9584 {
9585 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9586 }
9587 
9588 static int dev_xdp_detach_link(struct net_device *dev,
9589 			       struct netlink_ext_ack *extack,
9590 			       struct bpf_xdp_link *link)
9591 {
9592 	enum bpf_xdp_mode mode;
9593 	bpf_op_t bpf_op;
9594 
9595 	ASSERT_RTNL();
9596 
9597 	mode = dev_xdp_mode(dev, link->flags);
9598 	if (dev_xdp_link(dev, mode) != link)
9599 		return -EINVAL;
9600 
9601 	bpf_op = dev_xdp_bpf_op(dev, mode);
9602 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9603 	dev_xdp_set_link(dev, mode, NULL);
9604 	return 0;
9605 }
9606 
9607 static void bpf_xdp_link_release(struct bpf_link *link)
9608 {
9609 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9610 
9611 	rtnl_lock();
9612 
9613 	/* if racing with net_device's tear down, xdp_link->dev might be
9614 	 * already NULL, in which case link was already auto-detached
9615 	 */
9616 	if (xdp_link->dev) {
9617 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9618 		xdp_link->dev = NULL;
9619 	}
9620 
9621 	rtnl_unlock();
9622 }
9623 
9624 static int bpf_xdp_link_detach(struct bpf_link *link)
9625 {
9626 	bpf_xdp_link_release(link);
9627 	return 0;
9628 }
9629 
9630 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9631 {
9632 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9633 
9634 	kfree(xdp_link);
9635 }
9636 
9637 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9638 				     struct seq_file *seq)
9639 {
9640 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9641 	u32 ifindex = 0;
9642 
9643 	rtnl_lock();
9644 	if (xdp_link->dev)
9645 		ifindex = xdp_link->dev->ifindex;
9646 	rtnl_unlock();
9647 
9648 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9649 }
9650 
9651 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9652 				       struct bpf_link_info *info)
9653 {
9654 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9655 	u32 ifindex = 0;
9656 
9657 	rtnl_lock();
9658 	if (xdp_link->dev)
9659 		ifindex = xdp_link->dev->ifindex;
9660 	rtnl_unlock();
9661 
9662 	info->xdp.ifindex = ifindex;
9663 	return 0;
9664 }
9665 
9666 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9667 			       struct bpf_prog *old_prog)
9668 {
9669 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9670 	enum bpf_xdp_mode mode;
9671 	bpf_op_t bpf_op;
9672 	int err = 0;
9673 
9674 	rtnl_lock();
9675 
9676 	/* link might have been auto-released already, so fail */
9677 	if (!xdp_link->dev) {
9678 		err = -ENOLINK;
9679 		goto out_unlock;
9680 	}
9681 
9682 	if (old_prog && link->prog != old_prog) {
9683 		err = -EPERM;
9684 		goto out_unlock;
9685 	}
9686 	old_prog = link->prog;
9687 	if (old_prog->type != new_prog->type ||
9688 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9689 		err = -EINVAL;
9690 		goto out_unlock;
9691 	}
9692 
9693 	if (old_prog == new_prog) {
9694 		/* no-op, don't disturb drivers */
9695 		bpf_prog_put(new_prog);
9696 		goto out_unlock;
9697 	}
9698 
9699 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9700 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9701 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9702 			      xdp_link->flags, new_prog);
9703 	if (err)
9704 		goto out_unlock;
9705 
9706 	old_prog = xchg(&link->prog, new_prog);
9707 	bpf_prog_put(old_prog);
9708 
9709 out_unlock:
9710 	rtnl_unlock();
9711 	return err;
9712 }
9713 
9714 static const struct bpf_link_ops bpf_xdp_link_lops = {
9715 	.release = bpf_xdp_link_release,
9716 	.dealloc = bpf_xdp_link_dealloc,
9717 	.detach = bpf_xdp_link_detach,
9718 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9719 	.fill_link_info = bpf_xdp_link_fill_link_info,
9720 	.update_prog = bpf_xdp_link_update,
9721 };
9722 
9723 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9724 {
9725 	struct net *net = current->nsproxy->net_ns;
9726 	struct bpf_link_primer link_primer;
9727 	struct netlink_ext_ack extack = {};
9728 	struct bpf_xdp_link *link;
9729 	struct net_device *dev;
9730 	int err, fd;
9731 
9732 	rtnl_lock();
9733 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9734 	if (!dev) {
9735 		rtnl_unlock();
9736 		return -EINVAL;
9737 	}
9738 
9739 	link = kzalloc(sizeof(*link), GFP_USER);
9740 	if (!link) {
9741 		err = -ENOMEM;
9742 		goto unlock;
9743 	}
9744 
9745 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9746 	link->dev = dev;
9747 	link->flags = attr->link_create.flags;
9748 
9749 	err = bpf_link_prime(&link->link, &link_primer);
9750 	if (err) {
9751 		kfree(link);
9752 		goto unlock;
9753 	}
9754 
9755 	err = dev_xdp_attach_link(dev, &extack, link);
9756 	rtnl_unlock();
9757 
9758 	if (err) {
9759 		link->dev = NULL;
9760 		bpf_link_cleanup(&link_primer);
9761 		trace_bpf_xdp_link_attach_failed(extack._msg);
9762 		goto out_put_dev;
9763 	}
9764 
9765 	fd = bpf_link_settle(&link_primer);
9766 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9767 	dev_put(dev);
9768 	return fd;
9769 
9770 unlock:
9771 	rtnl_unlock();
9772 
9773 out_put_dev:
9774 	dev_put(dev);
9775 	return err;
9776 }
9777 
9778 /**
9779  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9780  *	@dev: device
9781  *	@extack: netlink extended ack
9782  *	@fd: new program fd or negative value to clear
9783  *	@expected_fd: old program fd that userspace expects to replace or clear
9784  *	@flags: xdp-related flags
9785  *
9786  *	Set or clear a bpf program for a device
9787  */
9788 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9789 		      int fd, int expected_fd, u32 flags)
9790 {
9791 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9792 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9793 	int err;
9794 
9795 	ASSERT_RTNL();
9796 
9797 	if (fd >= 0) {
9798 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9799 						 mode != XDP_MODE_SKB);
9800 		if (IS_ERR(new_prog))
9801 			return PTR_ERR(new_prog);
9802 	}
9803 
9804 	if (expected_fd >= 0) {
9805 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9806 						 mode != XDP_MODE_SKB);
9807 		if (IS_ERR(old_prog)) {
9808 			err = PTR_ERR(old_prog);
9809 			old_prog = NULL;
9810 			goto err_out;
9811 		}
9812 	}
9813 
9814 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9815 
9816 err_out:
9817 	if (err && new_prog)
9818 		bpf_prog_put(new_prog);
9819 	if (old_prog)
9820 		bpf_prog_put(old_prog);
9821 	return err;
9822 }
9823 
9824 /**
9825  * dev_index_reserve() - allocate an ifindex in a namespace
9826  * @net: the applicable net namespace
9827  * @ifindex: requested ifindex, pass %0 to get one allocated
9828  *
9829  * Allocate a ifindex for a new device. Caller must either use the ifindex
9830  * to store the device (via list_netdevice()) or call dev_index_release()
9831  * to give the index up.
9832  *
9833  * Return: a suitable unique value for a new device interface number or -errno.
9834  */
9835 static int dev_index_reserve(struct net *net, u32 ifindex)
9836 {
9837 	int err;
9838 
9839 	if (ifindex > INT_MAX) {
9840 		DEBUG_NET_WARN_ON_ONCE(1);
9841 		return -EINVAL;
9842 	}
9843 
9844 	if (!ifindex)
9845 		err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
9846 				      xa_limit_31b, &net->ifindex, GFP_KERNEL);
9847 	else
9848 		err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
9849 	if (err < 0)
9850 		return err;
9851 
9852 	return ifindex;
9853 }
9854 
9855 static void dev_index_release(struct net *net, int ifindex)
9856 {
9857 	/* Expect only unused indexes, unlist_netdevice() removes the used */
9858 	WARN_ON(xa_erase(&net->dev_by_index, ifindex));
9859 }
9860 
9861 /* Delayed registration/unregisteration */
9862 LIST_HEAD(net_todo_list);
9863 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9864 atomic_t dev_unreg_count = ATOMIC_INIT(0);
9865 
9866 static void net_set_todo(struct net_device *dev)
9867 {
9868 	list_add_tail(&dev->todo_list, &net_todo_list);
9869 }
9870 
9871 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9872 	struct net_device *upper, netdev_features_t features)
9873 {
9874 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9875 	netdev_features_t feature;
9876 	int feature_bit;
9877 
9878 	for_each_netdev_feature(upper_disables, feature_bit) {
9879 		feature = __NETIF_F_BIT(feature_bit);
9880 		if (!(upper->wanted_features & feature)
9881 		    && (features & feature)) {
9882 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9883 				   &feature, upper->name);
9884 			features &= ~feature;
9885 		}
9886 	}
9887 
9888 	return features;
9889 }
9890 
9891 static void netdev_sync_lower_features(struct net_device *upper,
9892 	struct net_device *lower, netdev_features_t features)
9893 {
9894 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9895 	netdev_features_t feature;
9896 	int feature_bit;
9897 
9898 	for_each_netdev_feature(upper_disables, feature_bit) {
9899 		feature = __NETIF_F_BIT(feature_bit);
9900 		if (!(features & feature) && (lower->features & feature)) {
9901 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9902 				   &feature, lower->name);
9903 			lower->wanted_features &= ~feature;
9904 			__netdev_update_features(lower);
9905 
9906 			if (unlikely(lower->features & feature))
9907 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9908 					    &feature, lower->name);
9909 			else
9910 				netdev_features_change(lower);
9911 		}
9912 	}
9913 }
9914 
9915 static bool netdev_has_ip_or_hw_csum(netdev_features_t features)
9916 {
9917 	netdev_features_t ip_csum_mask = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
9918 	bool ip_csum = (features & ip_csum_mask) == ip_csum_mask;
9919 	bool hw_csum = features & NETIF_F_HW_CSUM;
9920 
9921 	return ip_csum || hw_csum;
9922 }
9923 
9924 static netdev_features_t netdev_fix_features(struct net_device *dev,
9925 	netdev_features_t features)
9926 {
9927 	/* Fix illegal checksum combinations */
9928 	if ((features & NETIF_F_HW_CSUM) &&
9929 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9930 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9931 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9932 	}
9933 
9934 	/* TSO requires that SG is present as well. */
9935 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9936 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9937 		features &= ~NETIF_F_ALL_TSO;
9938 	}
9939 
9940 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9941 					!(features & NETIF_F_IP_CSUM)) {
9942 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9943 		features &= ~NETIF_F_TSO;
9944 		features &= ~NETIF_F_TSO_ECN;
9945 	}
9946 
9947 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9948 					 !(features & NETIF_F_IPV6_CSUM)) {
9949 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9950 		features &= ~NETIF_F_TSO6;
9951 	}
9952 
9953 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9954 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9955 		features &= ~NETIF_F_TSO_MANGLEID;
9956 
9957 	/* TSO ECN requires that TSO is present as well. */
9958 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9959 		features &= ~NETIF_F_TSO_ECN;
9960 
9961 	/* Software GSO depends on SG. */
9962 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9963 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9964 		features &= ~NETIF_F_GSO;
9965 	}
9966 
9967 	/* GSO partial features require GSO partial be set */
9968 	if ((features & dev->gso_partial_features) &&
9969 	    !(features & NETIF_F_GSO_PARTIAL)) {
9970 		netdev_dbg(dev,
9971 			   "Dropping partially supported GSO features since no GSO partial.\n");
9972 		features &= ~dev->gso_partial_features;
9973 	}
9974 
9975 	if (!(features & NETIF_F_RXCSUM)) {
9976 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9977 		 * successfully merged by hardware must also have the
9978 		 * checksum verified by hardware.  If the user does not
9979 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9980 		 */
9981 		if (features & NETIF_F_GRO_HW) {
9982 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9983 			features &= ~NETIF_F_GRO_HW;
9984 		}
9985 	}
9986 
9987 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9988 	if (features & NETIF_F_RXFCS) {
9989 		if (features & NETIF_F_LRO) {
9990 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9991 			features &= ~NETIF_F_LRO;
9992 		}
9993 
9994 		if (features & NETIF_F_GRO_HW) {
9995 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9996 			features &= ~NETIF_F_GRO_HW;
9997 		}
9998 	}
9999 
10000 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
10001 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
10002 		features &= ~NETIF_F_LRO;
10003 	}
10004 
10005 	if ((features & NETIF_F_HW_TLS_TX) && !netdev_has_ip_or_hw_csum(features)) {
10006 		netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
10007 		features &= ~NETIF_F_HW_TLS_TX;
10008 	}
10009 
10010 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
10011 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
10012 		features &= ~NETIF_F_HW_TLS_RX;
10013 	}
10014 
10015 	if ((features & NETIF_F_GSO_UDP_L4) && !netdev_has_ip_or_hw_csum(features)) {
10016 		netdev_dbg(dev, "Dropping USO feature since no CSUM feature.\n");
10017 		features &= ~NETIF_F_GSO_UDP_L4;
10018 	}
10019 
10020 	return features;
10021 }
10022 
10023 int __netdev_update_features(struct net_device *dev)
10024 {
10025 	struct net_device *upper, *lower;
10026 	netdev_features_t features;
10027 	struct list_head *iter;
10028 	int err = -1;
10029 
10030 	ASSERT_RTNL();
10031 
10032 	features = netdev_get_wanted_features(dev);
10033 
10034 	if (dev->netdev_ops->ndo_fix_features)
10035 		features = dev->netdev_ops->ndo_fix_features(dev, features);
10036 
10037 	/* driver might be less strict about feature dependencies */
10038 	features = netdev_fix_features(dev, features);
10039 
10040 	/* some features can't be enabled if they're off on an upper device */
10041 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
10042 		features = netdev_sync_upper_features(dev, upper, features);
10043 
10044 	if (dev->features == features)
10045 		goto sync_lower;
10046 
10047 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
10048 		&dev->features, &features);
10049 
10050 	if (dev->netdev_ops->ndo_set_features)
10051 		err = dev->netdev_ops->ndo_set_features(dev, features);
10052 	else
10053 		err = 0;
10054 
10055 	if (unlikely(err < 0)) {
10056 		netdev_err(dev,
10057 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
10058 			err, &features, &dev->features);
10059 		/* return non-0 since some features might have changed and
10060 		 * it's better to fire a spurious notification than miss it
10061 		 */
10062 		return -1;
10063 	}
10064 
10065 sync_lower:
10066 	/* some features must be disabled on lower devices when disabled
10067 	 * on an upper device (think: bonding master or bridge)
10068 	 */
10069 	netdev_for_each_lower_dev(dev, lower, iter)
10070 		netdev_sync_lower_features(dev, lower, features);
10071 
10072 	if (!err) {
10073 		netdev_features_t diff = features ^ dev->features;
10074 
10075 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
10076 			/* udp_tunnel_{get,drop}_rx_info both need
10077 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
10078 			 * device, or they won't do anything.
10079 			 * Thus we need to update dev->features
10080 			 * *before* calling udp_tunnel_get_rx_info,
10081 			 * but *after* calling udp_tunnel_drop_rx_info.
10082 			 */
10083 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
10084 				dev->features = features;
10085 				udp_tunnel_get_rx_info(dev);
10086 			} else {
10087 				udp_tunnel_drop_rx_info(dev);
10088 			}
10089 		}
10090 
10091 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
10092 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
10093 				dev->features = features;
10094 				err |= vlan_get_rx_ctag_filter_info(dev);
10095 			} else {
10096 				vlan_drop_rx_ctag_filter_info(dev);
10097 			}
10098 		}
10099 
10100 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
10101 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
10102 				dev->features = features;
10103 				err |= vlan_get_rx_stag_filter_info(dev);
10104 			} else {
10105 				vlan_drop_rx_stag_filter_info(dev);
10106 			}
10107 		}
10108 
10109 		dev->features = features;
10110 	}
10111 
10112 	return err < 0 ? 0 : 1;
10113 }
10114 
10115 /**
10116  *	netdev_update_features - recalculate device features
10117  *	@dev: the device to check
10118  *
10119  *	Recalculate dev->features set and send notifications if it
10120  *	has changed. Should be called after driver or hardware dependent
10121  *	conditions might have changed that influence the features.
10122  */
10123 void netdev_update_features(struct net_device *dev)
10124 {
10125 	if (__netdev_update_features(dev))
10126 		netdev_features_change(dev);
10127 }
10128 EXPORT_SYMBOL(netdev_update_features);
10129 
10130 /**
10131  *	netdev_change_features - recalculate device features
10132  *	@dev: the device to check
10133  *
10134  *	Recalculate dev->features set and send notifications even
10135  *	if they have not changed. Should be called instead of
10136  *	netdev_update_features() if also dev->vlan_features might
10137  *	have changed to allow the changes to be propagated to stacked
10138  *	VLAN devices.
10139  */
10140 void netdev_change_features(struct net_device *dev)
10141 {
10142 	__netdev_update_features(dev);
10143 	netdev_features_change(dev);
10144 }
10145 EXPORT_SYMBOL(netdev_change_features);
10146 
10147 /**
10148  *	netif_stacked_transfer_operstate -	transfer operstate
10149  *	@rootdev: the root or lower level device to transfer state from
10150  *	@dev: the device to transfer operstate to
10151  *
10152  *	Transfer operational state from root to device. This is normally
10153  *	called when a stacking relationship exists between the root
10154  *	device and the device(a leaf device).
10155  */
10156 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
10157 					struct net_device *dev)
10158 {
10159 	if (rootdev->operstate == IF_OPER_DORMANT)
10160 		netif_dormant_on(dev);
10161 	else
10162 		netif_dormant_off(dev);
10163 
10164 	if (rootdev->operstate == IF_OPER_TESTING)
10165 		netif_testing_on(dev);
10166 	else
10167 		netif_testing_off(dev);
10168 
10169 	if (netif_carrier_ok(rootdev))
10170 		netif_carrier_on(dev);
10171 	else
10172 		netif_carrier_off(dev);
10173 }
10174 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
10175 
10176 static int netif_alloc_rx_queues(struct net_device *dev)
10177 {
10178 	unsigned int i, count = dev->num_rx_queues;
10179 	struct netdev_rx_queue *rx;
10180 	size_t sz = count * sizeof(*rx);
10181 	int err = 0;
10182 
10183 	BUG_ON(count < 1);
10184 
10185 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10186 	if (!rx)
10187 		return -ENOMEM;
10188 
10189 	dev->_rx = rx;
10190 
10191 	for (i = 0; i < count; i++) {
10192 		rx[i].dev = dev;
10193 
10194 		/* XDP RX-queue setup */
10195 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
10196 		if (err < 0)
10197 			goto err_rxq_info;
10198 	}
10199 	return 0;
10200 
10201 err_rxq_info:
10202 	/* Rollback successful reg's and free other resources */
10203 	while (i--)
10204 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
10205 	kvfree(dev->_rx);
10206 	dev->_rx = NULL;
10207 	return err;
10208 }
10209 
10210 static void netif_free_rx_queues(struct net_device *dev)
10211 {
10212 	unsigned int i, count = dev->num_rx_queues;
10213 
10214 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
10215 	if (!dev->_rx)
10216 		return;
10217 
10218 	for (i = 0; i < count; i++)
10219 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
10220 
10221 	kvfree(dev->_rx);
10222 }
10223 
10224 static void netdev_init_one_queue(struct net_device *dev,
10225 				  struct netdev_queue *queue, void *_unused)
10226 {
10227 	/* Initialize queue lock */
10228 	spin_lock_init(&queue->_xmit_lock);
10229 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
10230 	queue->xmit_lock_owner = -1;
10231 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
10232 	queue->dev = dev;
10233 #ifdef CONFIG_BQL
10234 	dql_init(&queue->dql, HZ);
10235 #endif
10236 }
10237 
10238 static void netif_free_tx_queues(struct net_device *dev)
10239 {
10240 	kvfree(dev->_tx);
10241 }
10242 
10243 static int netif_alloc_netdev_queues(struct net_device *dev)
10244 {
10245 	unsigned int count = dev->num_tx_queues;
10246 	struct netdev_queue *tx;
10247 	size_t sz = count * sizeof(*tx);
10248 
10249 	if (count < 1 || count > 0xffff)
10250 		return -EINVAL;
10251 
10252 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10253 	if (!tx)
10254 		return -ENOMEM;
10255 
10256 	dev->_tx = tx;
10257 
10258 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
10259 	spin_lock_init(&dev->tx_global_lock);
10260 
10261 	return 0;
10262 }
10263 
10264 void netif_tx_stop_all_queues(struct net_device *dev)
10265 {
10266 	unsigned int i;
10267 
10268 	for (i = 0; i < dev->num_tx_queues; i++) {
10269 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
10270 
10271 		netif_tx_stop_queue(txq);
10272 	}
10273 }
10274 EXPORT_SYMBOL(netif_tx_stop_all_queues);
10275 
10276 static int netdev_do_alloc_pcpu_stats(struct net_device *dev)
10277 {
10278 	void __percpu *v;
10279 
10280 	/* Drivers implementing ndo_get_peer_dev must support tstat
10281 	 * accounting, so that skb_do_redirect() can bump the dev's
10282 	 * RX stats upon network namespace switch.
10283 	 */
10284 	if (dev->netdev_ops->ndo_get_peer_dev &&
10285 	    dev->pcpu_stat_type != NETDEV_PCPU_STAT_TSTATS)
10286 		return -EOPNOTSUPP;
10287 
10288 	switch (dev->pcpu_stat_type) {
10289 	case NETDEV_PCPU_STAT_NONE:
10290 		return 0;
10291 	case NETDEV_PCPU_STAT_LSTATS:
10292 		v = dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
10293 		break;
10294 	case NETDEV_PCPU_STAT_TSTATS:
10295 		v = dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
10296 		break;
10297 	case NETDEV_PCPU_STAT_DSTATS:
10298 		v = dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
10299 		break;
10300 	default:
10301 		return -EINVAL;
10302 	}
10303 
10304 	return v ? 0 : -ENOMEM;
10305 }
10306 
10307 static void netdev_do_free_pcpu_stats(struct net_device *dev)
10308 {
10309 	switch (dev->pcpu_stat_type) {
10310 	case NETDEV_PCPU_STAT_NONE:
10311 		return;
10312 	case NETDEV_PCPU_STAT_LSTATS:
10313 		free_percpu(dev->lstats);
10314 		break;
10315 	case NETDEV_PCPU_STAT_TSTATS:
10316 		free_percpu(dev->tstats);
10317 		break;
10318 	case NETDEV_PCPU_STAT_DSTATS:
10319 		free_percpu(dev->dstats);
10320 		break;
10321 	}
10322 }
10323 
10324 /**
10325  * register_netdevice() - register a network device
10326  * @dev: device to register
10327  *
10328  * Take a prepared network device structure and make it externally accessible.
10329  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
10330  * Callers must hold the rtnl lock - you may want register_netdev()
10331  * instead of this.
10332  */
10333 int register_netdevice(struct net_device *dev)
10334 {
10335 	int ret;
10336 	struct net *net = dev_net(dev);
10337 
10338 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
10339 		     NETDEV_FEATURE_COUNT);
10340 	BUG_ON(dev_boot_phase);
10341 	ASSERT_RTNL();
10342 
10343 	might_sleep();
10344 
10345 	/* When net_device's are persistent, this will be fatal. */
10346 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
10347 	BUG_ON(!net);
10348 
10349 	ret = ethtool_check_ops(dev->ethtool_ops);
10350 	if (ret)
10351 		return ret;
10352 
10353 	/* rss ctx ID 0 is reserved for the default context, start from 1 */
10354 	xa_init_flags(&dev->ethtool->rss_ctx, XA_FLAGS_ALLOC1);
10355 	mutex_init(&dev->ethtool->rss_lock);
10356 
10357 	spin_lock_init(&dev->addr_list_lock);
10358 	netdev_set_addr_lockdep_class(dev);
10359 
10360 	ret = dev_get_valid_name(net, dev, dev->name);
10361 	if (ret < 0)
10362 		goto out;
10363 
10364 	ret = -ENOMEM;
10365 	dev->name_node = netdev_name_node_head_alloc(dev);
10366 	if (!dev->name_node)
10367 		goto out;
10368 
10369 	/* Init, if this function is available */
10370 	if (dev->netdev_ops->ndo_init) {
10371 		ret = dev->netdev_ops->ndo_init(dev);
10372 		if (ret) {
10373 			if (ret > 0)
10374 				ret = -EIO;
10375 			goto err_free_name;
10376 		}
10377 	}
10378 
10379 	if (((dev->hw_features | dev->features) &
10380 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10381 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10382 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10383 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10384 		ret = -EINVAL;
10385 		goto err_uninit;
10386 	}
10387 
10388 	ret = netdev_do_alloc_pcpu_stats(dev);
10389 	if (ret)
10390 		goto err_uninit;
10391 
10392 	ret = dev_index_reserve(net, dev->ifindex);
10393 	if (ret < 0)
10394 		goto err_free_pcpu;
10395 	dev->ifindex = ret;
10396 
10397 	/* Transfer changeable features to wanted_features and enable
10398 	 * software offloads (GSO and GRO).
10399 	 */
10400 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10401 	dev->features |= NETIF_F_SOFT_FEATURES;
10402 
10403 	if (dev->udp_tunnel_nic_info) {
10404 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10405 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10406 	}
10407 
10408 	dev->wanted_features = dev->features & dev->hw_features;
10409 
10410 	if (!(dev->flags & IFF_LOOPBACK))
10411 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10412 
10413 	/* If IPv4 TCP segmentation offload is supported we should also
10414 	 * allow the device to enable segmenting the frame with the option
10415 	 * of ignoring a static IP ID value.  This doesn't enable the
10416 	 * feature itself but allows the user to enable it later.
10417 	 */
10418 	if (dev->hw_features & NETIF_F_TSO)
10419 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10420 	if (dev->vlan_features & NETIF_F_TSO)
10421 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10422 	if (dev->mpls_features & NETIF_F_TSO)
10423 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10424 	if (dev->hw_enc_features & NETIF_F_TSO)
10425 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10426 
10427 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10428 	 */
10429 	dev->vlan_features |= NETIF_F_HIGHDMA;
10430 
10431 	/* Make NETIF_F_SG inheritable to tunnel devices.
10432 	 */
10433 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10434 
10435 	/* Make NETIF_F_SG inheritable to MPLS.
10436 	 */
10437 	dev->mpls_features |= NETIF_F_SG;
10438 
10439 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10440 	ret = notifier_to_errno(ret);
10441 	if (ret)
10442 		goto err_ifindex_release;
10443 
10444 	ret = netdev_register_kobject(dev);
10445 
10446 	WRITE_ONCE(dev->reg_state, ret ? NETREG_UNREGISTERED : NETREG_REGISTERED);
10447 
10448 	if (ret)
10449 		goto err_uninit_notify;
10450 
10451 	__netdev_update_features(dev);
10452 
10453 	/*
10454 	 *	Default initial state at registry is that the
10455 	 *	device is present.
10456 	 */
10457 
10458 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10459 
10460 	linkwatch_init_dev(dev);
10461 
10462 	dev_init_scheduler(dev);
10463 
10464 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10465 	list_netdevice(dev);
10466 
10467 	add_device_randomness(dev->dev_addr, dev->addr_len);
10468 
10469 	/* If the device has permanent device address, driver should
10470 	 * set dev_addr and also addr_assign_type should be set to
10471 	 * NET_ADDR_PERM (default value).
10472 	 */
10473 	if (dev->addr_assign_type == NET_ADDR_PERM)
10474 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10475 
10476 	/* Notify protocols, that a new device appeared. */
10477 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10478 	ret = notifier_to_errno(ret);
10479 	if (ret) {
10480 		/* Expect explicit free_netdev() on failure */
10481 		dev->needs_free_netdev = false;
10482 		unregister_netdevice_queue(dev, NULL);
10483 		goto out;
10484 	}
10485 	/*
10486 	 *	Prevent userspace races by waiting until the network
10487 	 *	device is fully setup before sending notifications.
10488 	 */
10489 	if (!dev->rtnl_link_ops ||
10490 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10491 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10492 
10493 out:
10494 	return ret;
10495 
10496 err_uninit_notify:
10497 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10498 err_ifindex_release:
10499 	dev_index_release(net, dev->ifindex);
10500 err_free_pcpu:
10501 	netdev_do_free_pcpu_stats(dev);
10502 err_uninit:
10503 	if (dev->netdev_ops->ndo_uninit)
10504 		dev->netdev_ops->ndo_uninit(dev);
10505 	if (dev->priv_destructor)
10506 		dev->priv_destructor(dev);
10507 err_free_name:
10508 	netdev_name_node_free(dev->name_node);
10509 	goto out;
10510 }
10511 EXPORT_SYMBOL(register_netdevice);
10512 
10513 /* Initialize the core of a dummy net device.
10514  * This is useful if you are calling this function after alloc_netdev(),
10515  * since it does not memset the net_device fields.
10516  */
10517 static void init_dummy_netdev_core(struct net_device *dev)
10518 {
10519 	/* make sure we BUG if trying to hit standard
10520 	 * register/unregister code path
10521 	 */
10522 	dev->reg_state = NETREG_DUMMY;
10523 
10524 	/* NAPI wants this */
10525 	INIT_LIST_HEAD(&dev->napi_list);
10526 
10527 	/* a dummy interface is started by default */
10528 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10529 	set_bit(__LINK_STATE_START, &dev->state);
10530 
10531 	/* napi_busy_loop stats accounting wants this */
10532 	dev_net_set(dev, &init_net);
10533 
10534 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10535 	 * because users of this 'device' dont need to change
10536 	 * its refcount.
10537 	 */
10538 }
10539 
10540 /**
10541  *	init_dummy_netdev	- init a dummy network device for NAPI
10542  *	@dev: device to init
10543  *
10544  *	This takes a network device structure and initializes the minimum
10545  *	amount of fields so it can be used to schedule NAPI polls without
10546  *	registering a full blown interface. This is to be used by drivers
10547  *	that need to tie several hardware interfaces to a single NAPI
10548  *	poll scheduler due to HW limitations.
10549  */
10550 void init_dummy_netdev(struct net_device *dev)
10551 {
10552 	/* Clear everything. Note we don't initialize spinlocks
10553 	 * as they aren't supposed to be taken by any of the
10554 	 * NAPI code and this dummy netdev is supposed to be
10555 	 * only ever used for NAPI polls
10556 	 */
10557 	memset(dev, 0, sizeof(struct net_device));
10558 	init_dummy_netdev_core(dev);
10559 }
10560 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10561 
10562 /**
10563  *	register_netdev	- register a network device
10564  *	@dev: device to register
10565  *
10566  *	Take a completed network device structure and add it to the kernel
10567  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10568  *	chain. 0 is returned on success. A negative errno code is returned
10569  *	on a failure to set up the device, or if the name is a duplicate.
10570  *
10571  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10572  *	and expands the device name if you passed a format string to
10573  *	alloc_netdev.
10574  */
10575 int register_netdev(struct net_device *dev)
10576 {
10577 	int err;
10578 
10579 	if (rtnl_lock_killable())
10580 		return -EINTR;
10581 	err = register_netdevice(dev);
10582 	rtnl_unlock();
10583 	return err;
10584 }
10585 EXPORT_SYMBOL(register_netdev);
10586 
10587 int netdev_refcnt_read(const struct net_device *dev)
10588 {
10589 #ifdef CONFIG_PCPU_DEV_REFCNT
10590 	int i, refcnt = 0;
10591 
10592 	for_each_possible_cpu(i)
10593 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10594 	return refcnt;
10595 #else
10596 	return refcount_read(&dev->dev_refcnt);
10597 #endif
10598 }
10599 EXPORT_SYMBOL(netdev_refcnt_read);
10600 
10601 int netdev_unregister_timeout_secs __read_mostly = 10;
10602 
10603 #define WAIT_REFS_MIN_MSECS 1
10604 #define WAIT_REFS_MAX_MSECS 250
10605 /**
10606  * netdev_wait_allrefs_any - wait until all references are gone.
10607  * @list: list of net_devices to wait on
10608  *
10609  * This is called when unregistering network devices.
10610  *
10611  * Any protocol or device that holds a reference should register
10612  * for netdevice notification, and cleanup and put back the
10613  * reference if they receive an UNREGISTER event.
10614  * We can get stuck here if buggy protocols don't correctly
10615  * call dev_put.
10616  */
10617 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10618 {
10619 	unsigned long rebroadcast_time, warning_time;
10620 	struct net_device *dev;
10621 	int wait = 0;
10622 
10623 	rebroadcast_time = warning_time = jiffies;
10624 
10625 	list_for_each_entry(dev, list, todo_list)
10626 		if (netdev_refcnt_read(dev) == 1)
10627 			return dev;
10628 
10629 	while (true) {
10630 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10631 			rtnl_lock();
10632 
10633 			/* Rebroadcast unregister notification */
10634 			list_for_each_entry(dev, list, todo_list)
10635 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10636 
10637 			__rtnl_unlock();
10638 			rcu_barrier();
10639 			rtnl_lock();
10640 
10641 			list_for_each_entry(dev, list, todo_list)
10642 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10643 					     &dev->state)) {
10644 					/* We must not have linkwatch events
10645 					 * pending on unregister. If this
10646 					 * happens, we simply run the queue
10647 					 * unscheduled, resulting in a noop
10648 					 * for this device.
10649 					 */
10650 					linkwatch_run_queue();
10651 					break;
10652 				}
10653 
10654 			__rtnl_unlock();
10655 
10656 			rebroadcast_time = jiffies;
10657 		}
10658 
10659 		rcu_barrier();
10660 
10661 		if (!wait) {
10662 			wait = WAIT_REFS_MIN_MSECS;
10663 		} else {
10664 			msleep(wait);
10665 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10666 		}
10667 
10668 		list_for_each_entry(dev, list, todo_list)
10669 			if (netdev_refcnt_read(dev) == 1)
10670 				return dev;
10671 
10672 		if (time_after(jiffies, warning_time +
10673 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10674 			list_for_each_entry(dev, list, todo_list) {
10675 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10676 					 dev->name, netdev_refcnt_read(dev));
10677 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10678 			}
10679 
10680 			warning_time = jiffies;
10681 		}
10682 	}
10683 }
10684 
10685 /* The sequence is:
10686  *
10687  *	rtnl_lock();
10688  *	...
10689  *	register_netdevice(x1);
10690  *	register_netdevice(x2);
10691  *	...
10692  *	unregister_netdevice(y1);
10693  *	unregister_netdevice(y2);
10694  *      ...
10695  *	rtnl_unlock();
10696  *	free_netdev(y1);
10697  *	free_netdev(y2);
10698  *
10699  * We are invoked by rtnl_unlock().
10700  * This allows us to deal with problems:
10701  * 1) We can delete sysfs objects which invoke hotplug
10702  *    without deadlocking with linkwatch via keventd.
10703  * 2) Since we run with the RTNL semaphore not held, we can sleep
10704  *    safely in order to wait for the netdev refcnt to drop to zero.
10705  *
10706  * We must not return until all unregister events added during
10707  * the interval the lock was held have been completed.
10708  */
10709 void netdev_run_todo(void)
10710 {
10711 	struct net_device *dev, *tmp;
10712 	struct list_head list;
10713 	int cnt;
10714 #ifdef CONFIG_LOCKDEP
10715 	struct list_head unlink_list;
10716 
10717 	list_replace_init(&net_unlink_list, &unlink_list);
10718 
10719 	while (!list_empty(&unlink_list)) {
10720 		struct net_device *dev = list_first_entry(&unlink_list,
10721 							  struct net_device,
10722 							  unlink_list);
10723 		list_del_init(&dev->unlink_list);
10724 		dev->nested_level = dev->lower_level - 1;
10725 	}
10726 #endif
10727 
10728 	/* Snapshot list, allow later requests */
10729 	list_replace_init(&net_todo_list, &list);
10730 
10731 	__rtnl_unlock();
10732 
10733 	/* Wait for rcu callbacks to finish before next phase */
10734 	if (!list_empty(&list))
10735 		rcu_barrier();
10736 
10737 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10738 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10739 			netdev_WARN(dev, "run_todo but not unregistering\n");
10740 			list_del(&dev->todo_list);
10741 			continue;
10742 		}
10743 
10744 		WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERED);
10745 		linkwatch_sync_dev(dev);
10746 	}
10747 
10748 	cnt = 0;
10749 	while (!list_empty(&list)) {
10750 		dev = netdev_wait_allrefs_any(&list);
10751 		list_del(&dev->todo_list);
10752 
10753 		/* paranoia */
10754 		BUG_ON(netdev_refcnt_read(dev) != 1);
10755 		BUG_ON(!list_empty(&dev->ptype_all));
10756 		BUG_ON(!list_empty(&dev->ptype_specific));
10757 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10758 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10759 
10760 		netdev_do_free_pcpu_stats(dev);
10761 		if (dev->priv_destructor)
10762 			dev->priv_destructor(dev);
10763 		if (dev->needs_free_netdev)
10764 			free_netdev(dev);
10765 
10766 		cnt++;
10767 
10768 		/* Free network device */
10769 		kobject_put(&dev->dev.kobj);
10770 	}
10771 	if (cnt && atomic_sub_and_test(cnt, &dev_unreg_count))
10772 		wake_up(&netdev_unregistering_wq);
10773 }
10774 
10775 /* Collate per-cpu network dstats statistics
10776  *
10777  * Read per-cpu network statistics from dev->dstats and populate the related
10778  * fields in @s.
10779  */
10780 static void dev_fetch_dstats(struct rtnl_link_stats64 *s,
10781 			     const struct pcpu_dstats __percpu *dstats)
10782 {
10783 	int cpu;
10784 
10785 	for_each_possible_cpu(cpu) {
10786 		u64 rx_packets, rx_bytes, rx_drops;
10787 		u64 tx_packets, tx_bytes, tx_drops;
10788 		const struct pcpu_dstats *stats;
10789 		unsigned int start;
10790 
10791 		stats = per_cpu_ptr(dstats, cpu);
10792 		do {
10793 			start = u64_stats_fetch_begin(&stats->syncp);
10794 			rx_packets = u64_stats_read(&stats->rx_packets);
10795 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10796 			rx_drops   = u64_stats_read(&stats->rx_drops);
10797 			tx_packets = u64_stats_read(&stats->tx_packets);
10798 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10799 			tx_drops   = u64_stats_read(&stats->tx_drops);
10800 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10801 
10802 		s->rx_packets += rx_packets;
10803 		s->rx_bytes   += rx_bytes;
10804 		s->rx_dropped += rx_drops;
10805 		s->tx_packets += tx_packets;
10806 		s->tx_bytes   += tx_bytes;
10807 		s->tx_dropped += tx_drops;
10808 	}
10809 }
10810 
10811 /* ndo_get_stats64 implementation for dtstats-based accounting.
10812  *
10813  * Populate @s from dev->stats and dev->dstats. This is used internally by the
10814  * core for NETDEV_PCPU_STAT_DSTAT-type stats collection.
10815  */
10816 static void dev_get_dstats64(const struct net_device *dev,
10817 			     struct rtnl_link_stats64 *s)
10818 {
10819 	netdev_stats_to_stats64(s, &dev->stats);
10820 	dev_fetch_dstats(s, dev->dstats);
10821 }
10822 
10823 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10824  * all the same fields in the same order as net_device_stats, with only
10825  * the type differing, but rtnl_link_stats64 may have additional fields
10826  * at the end for newer counters.
10827  */
10828 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10829 			     const struct net_device_stats *netdev_stats)
10830 {
10831 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10832 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10833 	u64 *dst = (u64 *)stats64;
10834 
10835 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10836 	for (i = 0; i < n; i++)
10837 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10838 	/* zero out counters that only exist in rtnl_link_stats64 */
10839 	memset((char *)stats64 + n * sizeof(u64), 0,
10840 	       sizeof(*stats64) - n * sizeof(u64));
10841 }
10842 EXPORT_SYMBOL(netdev_stats_to_stats64);
10843 
10844 static __cold struct net_device_core_stats __percpu *netdev_core_stats_alloc(
10845 		struct net_device *dev)
10846 {
10847 	struct net_device_core_stats __percpu *p;
10848 
10849 	p = alloc_percpu_gfp(struct net_device_core_stats,
10850 			     GFP_ATOMIC | __GFP_NOWARN);
10851 
10852 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10853 		free_percpu(p);
10854 
10855 	/* This READ_ONCE() pairs with the cmpxchg() above */
10856 	return READ_ONCE(dev->core_stats);
10857 }
10858 
10859 noinline void netdev_core_stats_inc(struct net_device *dev, u32 offset)
10860 {
10861 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10862 	struct net_device_core_stats __percpu *p = READ_ONCE(dev->core_stats);
10863 	unsigned long __percpu *field;
10864 
10865 	if (unlikely(!p)) {
10866 		p = netdev_core_stats_alloc(dev);
10867 		if (!p)
10868 			return;
10869 	}
10870 
10871 	field = (__force unsigned long __percpu *)((__force void *)p + offset);
10872 	this_cpu_inc(*field);
10873 }
10874 EXPORT_SYMBOL_GPL(netdev_core_stats_inc);
10875 
10876 /**
10877  *	dev_get_stats	- get network device statistics
10878  *	@dev: device to get statistics from
10879  *	@storage: place to store stats
10880  *
10881  *	Get network statistics from device. Return @storage.
10882  *	The device driver may provide its own method by setting
10883  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10884  *	otherwise the internal statistics structure is used.
10885  */
10886 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10887 					struct rtnl_link_stats64 *storage)
10888 {
10889 	const struct net_device_ops *ops = dev->netdev_ops;
10890 	const struct net_device_core_stats __percpu *p;
10891 
10892 	if (ops->ndo_get_stats64) {
10893 		memset(storage, 0, sizeof(*storage));
10894 		ops->ndo_get_stats64(dev, storage);
10895 	} else if (ops->ndo_get_stats) {
10896 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10897 	} else if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_TSTATS) {
10898 		dev_get_tstats64(dev, storage);
10899 	} else if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_DSTATS) {
10900 		dev_get_dstats64(dev, storage);
10901 	} else {
10902 		netdev_stats_to_stats64(storage, &dev->stats);
10903 	}
10904 
10905 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10906 	p = READ_ONCE(dev->core_stats);
10907 	if (p) {
10908 		const struct net_device_core_stats *core_stats;
10909 		int i;
10910 
10911 		for_each_possible_cpu(i) {
10912 			core_stats = per_cpu_ptr(p, i);
10913 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10914 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10915 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10916 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10917 		}
10918 	}
10919 	return storage;
10920 }
10921 EXPORT_SYMBOL(dev_get_stats);
10922 
10923 /**
10924  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10925  *	@s: place to store stats
10926  *	@netstats: per-cpu network stats to read from
10927  *
10928  *	Read per-cpu network statistics and populate the related fields in @s.
10929  */
10930 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10931 			   const struct pcpu_sw_netstats __percpu *netstats)
10932 {
10933 	int cpu;
10934 
10935 	for_each_possible_cpu(cpu) {
10936 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10937 		const struct pcpu_sw_netstats *stats;
10938 		unsigned int start;
10939 
10940 		stats = per_cpu_ptr(netstats, cpu);
10941 		do {
10942 			start = u64_stats_fetch_begin(&stats->syncp);
10943 			rx_packets = u64_stats_read(&stats->rx_packets);
10944 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10945 			tx_packets = u64_stats_read(&stats->tx_packets);
10946 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10947 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10948 
10949 		s->rx_packets += rx_packets;
10950 		s->rx_bytes   += rx_bytes;
10951 		s->tx_packets += tx_packets;
10952 		s->tx_bytes   += tx_bytes;
10953 	}
10954 }
10955 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10956 
10957 /**
10958  *	dev_get_tstats64 - ndo_get_stats64 implementation
10959  *	@dev: device to get statistics from
10960  *	@s: place to store stats
10961  *
10962  *	Populate @s from dev->stats and dev->tstats. Can be used as
10963  *	ndo_get_stats64() callback.
10964  */
10965 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10966 {
10967 	netdev_stats_to_stats64(s, &dev->stats);
10968 	dev_fetch_sw_netstats(s, dev->tstats);
10969 }
10970 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10971 
10972 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10973 {
10974 	struct netdev_queue *queue = dev_ingress_queue(dev);
10975 
10976 #ifdef CONFIG_NET_CLS_ACT
10977 	if (queue)
10978 		return queue;
10979 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10980 	if (!queue)
10981 		return NULL;
10982 	netdev_init_one_queue(dev, queue, NULL);
10983 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10984 	RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
10985 	rcu_assign_pointer(dev->ingress_queue, queue);
10986 #endif
10987 	return queue;
10988 }
10989 
10990 static const struct ethtool_ops default_ethtool_ops;
10991 
10992 void netdev_set_default_ethtool_ops(struct net_device *dev,
10993 				    const struct ethtool_ops *ops)
10994 {
10995 	if (dev->ethtool_ops == &default_ethtool_ops)
10996 		dev->ethtool_ops = ops;
10997 }
10998 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10999 
11000 /**
11001  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
11002  * @dev: netdev to enable the IRQ coalescing on
11003  *
11004  * Sets a conservative default for SW IRQ coalescing. Users can use
11005  * sysfs attributes to override the default values.
11006  */
11007 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
11008 {
11009 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
11010 
11011 	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
11012 		dev->gro_flush_timeout = 20000;
11013 		dev->napi_defer_hard_irqs = 1;
11014 	}
11015 }
11016 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
11017 
11018 /**
11019  * alloc_netdev_mqs - allocate network device
11020  * @sizeof_priv: size of private data to allocate space for
11021  * @name: device name format string
11022  * @name_assign_type: origin of device name
11023  * @setup: callback to initialize device
11024  * @txqs: the number of TX subqueues to allocate
11025  * @rxqs: the number of RX subqueues to allocate
11026  *
11027  * Allocates a struct net_device with private data area for driver use
11028  * and performs basic initialization.  Also allocates subqueue structs
11029  * for each queue on the device.
11030  */
11031 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
11032 		unsigned char name_assign_type,
11033 		void (*setup)(struct net_device *),
11034 		unsigned int txqs, unsigned int rxqs)
11035 {
11036 	struct net_device *dev;
11037 
11038 	BUG_ON(strlen(name) >= sizeof(dev->name));
11039 
11040 	if (txqs < 1) {
11041 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
11042 		return NULL;
11043 	}
11044 
11045 	if (rxqs < 1) {
11046 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
11047 		return NULL;
11048 	}
11049 
11050 	dev = kvzalloc(struct_size(dev, priv, sizeof_priv),
11051 		       GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
11052 	if (!dev)
11053 		return NULL;
11054 
11055 	dev->priv_len = sizeof_priv;
11056 
11057 	ref_tracker_dir_init(&dev->refcnt_tracker, 128, name);
11058 #ifdef CONFIG_PCPU_DEV_REFCNT
11059 	dev->pcpu_refcnt = alloc_percpu(int);
11060 	if (!dev->pcpu_refcnt)
11061 		goto free_dev;
11062 	__dev_hold(dev);
11063 #else
11064 	refcount_set(&dev->dev_refcnt, 1);
11065 #endif
11066 
11067 	if (dev_addr_init(dev))
11068 		goto free_pcpu;
11069 
11070 	dev_mc_init(dev);
11071 	dev_uc_init(dev);
11072 
11073 	dev_net_set(dev, &init_net);
11074 
11075 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
11076 	dev->xdp_zc_max_segs = 1;
11077 	dev->gso_max_segs = GSO_MAX_SEGS;
11078 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
11079 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
11080 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
11081 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
11082 	dev->tso_max_segs = TSO_MAX_SEGS;
11083 	dev->upper_level = 1;
11084 	dev->lower_level = 1;
11085 #ifdef CONFIG_LOCKDEP
11086 	dev->nested_level = 0;
11087 	INIT_LIST_HEAD(&dev->unlink_list);
11088 #endif
11089 
11090 	INIT_LIST_HEAD(&dev->napi_list);
11091 	INIT_LIST_HEAD(&dev->unreg_list);
11092 	INIT_LIST_HEAD(&dev->close_list);
11093 	INIT_LIST_HEAD(&dev->link_watch_list);
11094 	INIT_LIST_HEAD(&dev->adj_list.upper);
11095 	INIT_LIST_HEAD(&dev->adj_list.lower);
11096 	INIT_LIST_HEAD(&dev->ptype_all);
11097 	INIT_LIST_HEAD(&dev->ptype_specific);
11098 	INIT_LIST_HEAD(&dev->net_notifier_list);
11099 #ifdef CONFIG_NET_SCHED
11100 	hash_init(dev->qdisc_hash);
11101 #endif
11102 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
11103 	setup(dev);
11104 
11105 	if (!dev->tx_queue_len) {
11106 		dev->priv_flags |= IFF_NO_QUEUE;
11107 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
11108 	}
11109 
11110 	dev->num_tx_queues = txqs;
11111 	dev->real_num_tx_queues = txqs;
11112 	if (netif_alloc_netdev_queues(dev))
11113 		goto free_all;
11114 
11115 	dev->num_rx_queues = rxqs;
11116 	dev->real_num_rx_queues = rxqs;
11117 	if (netif_alloc_rx_queues(dev))
11118 		goto free_all;
11119 	dev->ethtool = kzalloc(sizeof(*dev->ethtool), GFP_KERNEL_ACCOUNT);
11120 	if (!dev->ethtool)
11121 		goto free_all;
11122 
11123 	strcpy(dev->name, name);
11124 	dev->name_assign_type = name_assign_type;
11125 	dev->group = INIT_NETDEV_GROUP;
11126 	if (!dev->ethtool_ops)
11127 		dev->ethtool_ops = &default_ethtool_ops;
11128 
11129 	nf_hook_netdev_init(dev);
11130 
11131 	return dev;
11132 
11133 free_all:
11134 	free_netdev(dev);
11135 	return NULL;
11136 
11137 free_pcpu:
11138 #ifdef CONFIG_PCPU_DEV_REFCNT
11139 	free_percpu(dev->pcpu_refcnt);
11140 free_dev:
11141 #endif
11142 	kvfree(dev);
11143 	return NULL;
11144 }
11145 EXPORT_SYMBOL(alloc_netdev_mqs);
11146 
11147 /**
11148  * free_netdev - free network device
11149  * @dev: device
11150  *
11151  * This function does the last stage of destroying an allocated device
11152  * interface. The reference to the device object is released. If this
11153  * is the last reference then it will be freed.Must be called in process
11154  * context.
11155  */
11156 void free_netdev(struct net_device *dev)
11157 {
11158 	struct napi_struct *p, *n;
11159 
11160 	might_sleep();
11161 
11162 	/* When called immediately after register_netdevice() failed the unwind
11163 	 * handling may still be dismantling the device. Handle that case by
11164 	 * deferring the free.
11165 	 */
11166 	if (dev->reg_state == NETREG_UNREGISTERING) {
11167 		ASSERT_RTNL();
11168 		dev->needs_free_netdev = true;
11169 		return;
11170 	}
11171 
11172 	kfree(dev->ethtool);
11173 	netif_free_tx_queues(dev);
11174 	netif_free_rx_queues(dev);
11175 
11176 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
11177 
11178 	/* Flush device addresses */
11179 	dev_addr_flush(dev);
11180 
11181 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
11182 		netif_napi_del(p);
11183 
11184 	ref_tracker_dir_exit(&dev->refcnt_tracker);
11185 #ifdef CONFIG_PCPU_DEV_REFCNT
11186 	free_percpu(dev->pcpu_refcnt);
11187 	dev->pcpu_refcnt = NULL;
11188 #endif
11189 	free_percpu(dev->core_stats);
11190 	dev->core_stats = NULL;
11191 	free_percpu(dev->xdp_bulkq);
11192 	dev->xdp_bulkq = NULL;
11193 
11194 	/*  Compatibility with error handling in drivers */
11195 	if (dev->reg_state == NETREG_UNINITIALIZED ||
11196 	    dev->reg_state == NETREG_DUMMY) {
11197 		kvfree(dev);
11198 		return;
11199 	}
11200 
11201 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
11202 	WRITE_ONCE(dev->reg_state, NETREG_RELEASED);
11203 
11204 	/* will free via device release */
11205 	put_device(&dev->dev);
11206 }
11207 EXPORT_SYMBOL(free_netdev);
11208 
11209 /**
11210  * alloc_netdev_dummy - Allocate and initialize a dummy net device.
11211  * @sizeof_priv: size of private data to allocate space for
11212  *
11213  * Return: the allocated net_device on success, NULL otherwise
11214  */
11215 struct net_device *alloc_netdev_dummy(int sizeof_priv)
11216 {
11217 	return alloc_netdev(sizeof_priv, "dummy#", NET_NAME_UNKNOWN,
11218 			    init_dummy_netdev_core);
11219 }
11220 EXPORT_SYMBOL_GPL(alloc_netdev_dummy);
11221 
11222 /**
11223  *	synchronize_net -  Synchronize with packet receive processing
11224  *
11225  *	Wait for packets currently being received to be done.
11226  *	Does not block later packets from starting.
11227  */
11228 void synchronize_net(void)
11229 {
11230 	might_sleep();
11231 	if (rtnl_is_locked())
11232 		synchronize_rcu_expedited();
11233 	else
11234 		synchronize_rcu();
11235 }
11236 EXPORT_SYMBOL(synchronize_net);
11237 
11238 static void netdev_rss_contexts_free(struct net_device *dev)
11239 {
11240 	struct ethtool_rxfh_context *ctx;
11241 	unsigned long context;
11242 
11243 	mutex_lock(&dev->ethtool->rss_lock);
11244 	xa_for_each(&dev->ethtool->rss_ctx, context, ctx) {
11245 		struct ethtool_rxfh_param rxfh;
11246 
11247 		rxfh.indir = ethtool_rxfh_context_indir(ctx);
11248 		rxfh.key = ethtool_rxfh_context_key(ctx);
11249 		rxfh.hfunc = ctx->hfunc;
11250 		rxfh.input_xfrm = ctx->input_xfrm;
11251 		rxfh.rss_context = context;
11252 		rxfh.rss_delete = true;
11253 
11254 		xa_erase(&dev->ethtool->rss_ctx, context);
11255 		if (dev->ethtool_ops->create_rxfh_context)
11256 			dev->ethtool_ops->remove_rxfh_context(dev, ctx,
11257 							      context, NULL);
11258 		else
11259 			dev->ethtool_ops->set_rxfh(dev, &rxfh, NULL);
11260 		kfree(ctx);
11261 	}
11262 	xa_destroy(&dev->ethtool->rss_ctx);
11263 	mutex_unlock(&dev->ethtool->rss_lock);
11264 }
11265 
11266 /**
11267  *	unregister_netdevice_queue - remove device from the kernel
11268  *	@dev: device
11269  *	@head: list
11270  *
11271  *	This function shuts down a device interface and removes it
11272  *	from the kernel tables.
11273  *	If head not NULL, device is queued to be unregistered later.
11274  *
11275  *	Callers must hold the rtnl semaphore.  You may want
11276  *	unregister_netdev() instead of this.
11277  */
11278 
11279 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
11280 {
11281 	ASSERT_RTNL();
11282 
11283 	if (head) {
11284 		list_move_tail(&dev->unreg_list, head);
11285 	} else {
11286 		LIST_HEAD(single);
11287 
11288 		list_add(&dev->unreg_list, &single);
11289 		unregister_netdevice_many(&single);
11290 	}
11291 }
11292 EXPORT_SYMBOL(unregister_netdevice_queue);
11293 
11294 void unregister_netdevice_many_notify(struct list_head *head,
11295 				      u32 portid, const struct nlmsghdr *nlh)
11296 {
11297 	struct net_device *dev, *tmp;
11298 	LIST_HEAD(close_head);
11299 	int cnt = 0;
11300 
11301 	BUG_ON(dev_boot_phase);
11302 	ASSERT_RTNL();
11303 
11304 	if (list_empty(head))
11305 		return;
11306 
11307 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
11308 		/* Some devices call without registering
11309 		 * for initialization unwind. Remove those
11310 		 * devices and proceed with the remaining.
11311 		 */
11312 		if (dev->reg_state == NETREG_UNINITIALIZED) {
11313 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
11314 				 dev->name, dev);
11315 
11316 			WARN_ON(1);
11317 			list_del(&dev->unreg_list);
11318 			continue;
11319 		}
11320 		dev->dismantle = true;
11321 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
11322 	}
11323 
11324 	/* If device is running, close it first. */
11325 	list_for_each_entry(dev, head, unreg_list)
11326 		list_add_tail(&dev->close_list, &close_head);
11327 	dev_close_many(&close_head, true);
11328 
11329 	list_for_each_entry(dev, head, unreg_list) {
11330 		/* And unlink it from device chain. */
11331 		unlist_netdevice(dev);
11332 		WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERING);
11333 	}
11334 	flush_all_backlogs();
11335 
11336 	synchronize_net();
11337 
11338 	list_for_each_entry(dev, head, unreg_list) {
11339 		struct sk_buff *skb = NULL;
11340 
11341 		/* Shutdown queueing discipline. */
11342 		dev_shutdown(dev);
11343 		dev_tcx_uninstall(dev);
11344 		dev_xdp_uninstall(dev);
11345 		bpf_dev_bound_netdev_unregister(dev);
11346 
11347 		netdev_offload_xstats_disable_all(dev);
11348 
11349 		/* Notify protocols, that we are about to destroy
11350 		 * this device. They should clean all the things.
11351 		 */
11352 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11353 
11354 		if (!dev->rtnl_link_ops ||
11355 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
11356 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
11357 						     GFP_KERNEL, NULL, 0,
11358 						     portid, nlh);
11359 
11360 		/*
11361 		 *	Flush the unicast and multicast chains
11362 		 */
11363 		dev_uc_flush(dev);
11364 		dev_mc_flush(dev);
11365 
11366 		netdev_name_node_alt_flush(dev);
11367 		netdev_name_node_free(dev->name_node);
11368 
11369 		netdev_rss_contexts_free(dev);
11370 
11371 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
11372 
11373 		if (dev->netdev_ops->ndo_uninit)
11374 			dev->netdev_ops->ndo_uninit(dev);
11375 
11376 		mutex_destroy(&dev->ethtool->rss_lock);
11377 
11378 		if (skb)
11379 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
11380 
11381 		/* Notifier chain MUST detach us all upper devices. */
11382 		WARN_ON(netdev_has_any_upper_dev(dev));
11383 		WARN_ON(netdev_has_any_lower_dev(dev));
11384 
11385 		/* Remove entries from kobject tree */
11386 		netdev_unregister_kobject(dev);
11387 #ifdef CONFIG_XPS
11388 		/* Remove XPS queueing entries */
11389 		netif_reset_xps_queues_gt(dev, 0);
11390 #endif
11391 	}
11392 
11393 	synchronize_net();
11394 
11395 	list_for_each_entry(dev, head, unreg_list) {
11396 		netdev_put(dev, &dev->dev_registered_tracker);
11397 		net_set_todo(dev);
11398 		cnt++;
11399 	}
11400 	atomic_add(cnt, &dev_unreg_count);
11401 
11402 	list_del(head);
11403 }
11404 
11405 /**
11406  *	unregister_netdevice_many - unregister many devices
11407  *	@head: list of devices
11408  *
11409  *  Note: As most callers use a stack allocated list_head,
11410  *  we force a list_del() to make sure stack wont be corrupted later.
11411  */
11412 void unregister_netdevice_many(struct list_head *head)
11413 {
11414 	unregister_netdevice_many_notify(head, 0, NULL);
11415 }
11416 EXPORT_SYMBOL(unregister_netdevice_many);
11417 
11418 /**
11419  *	unregister_netdev - remove device from the kernel
11420  *	@dev: device
11421  *
11422  *	This function shuts down a device interface and removes it
11423  *	from the kernel tables.
11424  *
11425  *	This is just a wrapper for unregister_netdevice that takes
11426  *	the rtnl semaphore.  In general you want to use this and not
11427  *	unregister_netdevice.
11428  */
11429 void unregister_netdev(struct net_device *dev)
11430 {
11431 	rtnl_lock();
11432 	unregister_netdevice(dev);
11433 	rtnl_unlock();
11434 }
11435 EXPORT_SYMBOL(unregister_netdev);
11436 
11437 /**
11438  *	__dev_change_net_namespace - move device to different nethost namespace
11439  *	@dev: device
11440  *	@net: network namespace
11441  *	@pat: If not NULL name pattern to try if the current device name
11442  *	      is already taken in the destination network namespace.
11443  *	@new_ifindex: If not zero, specifies device index in the target
11444  *	              namespace.
11445  *
11446  *	This function shuts down a device interface and moves it
11447  *	to a new network namespace. On success 0 is returned, on
11448  *	a failure a netagive errno code is returned.
11449  *
11450  *	Callers must hold the rtnl semaphore.
11451  */
11452 
11453 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
11454 			       const char *pat, int new_ifindex)
11455 {
11456 	struct netdev_name_node *name_node;
11457 	struct net *net_old = dev_net(dev);
11458 	char new_name[IFNAMSIZ] = {};
11459 	int err, new_nsid;
11460 
11461 	ASSERT_RTNL();
11462 
11463 	/* Don't allow namespace local devices to be moved. */
11464 	err = -EINVAL;
11465 	if (dev->features & NETIF_F_NETNS_LOCAL)
11466 		goto out;
11467 
11468 	/* Ensure the device has been registrered */
11469 	if (dev->reg_state != NETREG_REGISTERED)
11470 		goto out;
11471 
11472 	/* Get out if there is nothing todo */
11473 	err = 0;
11474 	if (net_eq(net_old, net))
11475 		goto out;
11476 
11477 	/* Pick the destination device name, and ensure
11478 	 * we can use it in the destination network namespace.
11479 	 */
11480 	err = -EEXIST;
11481 	if (netdev_name_in_use(net, dev->name)) {
11482 		/* We get here if we can't use the current device name */
11483 		if (!pat)
11484 			goto out;
11485 		err = dev_prep_valid_name(net, dev, pat, new_name, EEXIST);
11486 		if (err < 0)
11487 			goto out;
11488 	}
11489 	/* Check that none of the altnames conflicts. */
11490 	err = -EEXIST;
11491 	netdev_for_each_altname(dev, name_node)
11492 		if (netdev_name_in_use(net, name_node->name))
11493 			goto out;
11494 
11495 	/* Check that new_ifindex isn't used yet. */
11496 	if (new_ifindex) {
11497 		err = dev_index_reserve(net, new_ifindex);
11498 		if (err < 0)
11499 			goto out;
11500 	} else {
11501 		/* If there is an ifindex conflict assign a new one */
11502 		err = dev_index_reserve(net, dev->ifindex);
11503 		if (err == -EBUSY)
11504 			err = dev_index_reserve(net, 0);
11505 		if (err < 0)
11506 			goto out;
11507 		new_ifindex = err;
11508 	}
11509 
11510 	/*
11511 	 * And now a mini version of register_netdevice unregister_netdevice.
11512 	 */
11513 
11514 	/* If device is running close it first. */
11515 	dev_close(dev);
11516 
11517 	/* And unlink it from device chain */
11518 	unlist_netdevice(dev);
11519 
11520 	synchronize_net();
11521 
11522 	/* Shutdown queueing discipline. */
11523 	dev_shutdown(dev);
11524 
11525 	/* Notify protocols, that we are about to destroy
11526 	 * this device. They should clean all the things.
11527 	 *
11528 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11529 	 * This is wanted because this way 8021q and macvlan know
11530 	 * the device is just moving and can keep their slaves up.
11531 	 */
11532 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11533 	rcu_barrier();
11534 
11535 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11536 
11537 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11538 			    new_ifindex);
11539 
11540 	/*
11541 	 *	Flush the unicast and multicast chains
11542 	 */
11543 	dev_uc_flush(dev);
11544 	dev_mc_flush(dev);
11545 
11546 	/* Send a netdev-removed uevent to the old namespace */
11547 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11548 	netdev_adjacent_del_links(dev);
11549 
11550 	/* Move per-net netdevice notifiers that are following the netdevice */
11551 	move_netdevice_notifiers_dev_net(dev, net);
11552 
11553 	/* Actually switch the network namespace */
11554 	dev_net_set(dev, net);
11555 	dev->ifindex = new_ifindex;
11556 
11557 	if (new_name[0]) {
11558 		/* Rename the netdev to prepared name */
11559 		write_seqlock_bh(&netdev_rename_lock);
11560 		strscpy(dev->name, new_name, IFNAMSIZ);
11561 		write_sequnlock_bh(&netdev_rename_lock);
11562 	}
11563 
11564 	/* Fixup kobjects */
11565 	dev_set_uevent_suppress(&dev->dev, 1);
11566 	err = device_rename(&dev->dev, dev->name);
11567 	dev_set_uevent_suppress(&dev->dev, 0);
11568 	WARN_ON(err);
11569 
11570 	/* Send a netdev-add uevent to the new namespace */
11571 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11572 	netdev_adjacent_add_links(dev);
11573 
11574 	/* Adapt owner in case owning user namespace of target network
11575 	 * namespace is different from the original one.
11576 	 */
11577 	err = netdev_change_owner(dev, net_old, net);
11578 	WARN_ON(err);
11579 
11580 	/* Add the device back in the hashes */
11581 	list_netdevice(dev);
11582 
11583 	/* Notify protocols, that a new device appeared. */
11584 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11585 
11586 	/*
11587 	 *	Prevent userspace races by waiting until the network
11588 	 *	device is fully setup before sending notifications.
11589 	 */
11590 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11591 
11592 	synchronize_net();
11593 	err = 0;
11594 out:
11595 	return err;
11596 }
11597 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11598 
11599 static int dev_cpu_dead(unsigned int oldcpu)
11600 {
11601 	struct sk_buff **list_skb;
11602 	struct sk_buff *skb;
11603 	unsigned int cpu;
11604 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11605 
11606 	local_irq_disable();
11607 	cpu = smp_processor_id();
11608 	sd = &per_cpu(softnet_data, cpu);
11609 	oldsd = &per_cpu(softnet_data, oldcpu);
11610 
11611 	/* Find end of our completion_queue. */
11612 	list_skb = &sd->completion_queue;
11613 	while (*list_skb)
11614 		list_skb = &(*list_skb)->next;
11615 	/* Append completion queue from offline CPU. */
11616 	*list_skb = oldsd->completion_queue;
11617 	oldsd->completion_queue = NULL;
11618 
11619 	/* Append output queue from offline CPU. */
11620 	if (oldsd->output_queue) {
11621 		*sd->output_queue_tailp = oldsd->output_queue;
11622 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11623 		oldsd->output_queue = NULL;
11624 		oldsd->output_queue_tailp = &oldsd->output_queue;
11625 	}
11626 	/* Append NAPI poll list from offline CPU, with one exception :
11627 	 * process_backlog() must be called by cpu owning percpu backlog.
11628 	 * We properly handle process_queue & input_pkt_queue later.
11629 	 */
11630 	while (!list_empty(&oldsd->poll_list)) {
11631 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11632 							    struct napi_struct,
11633 							    poll_list);
11634 
11635 		list_del_init(&napi->poll_list);
11636 		if (napi->poll == process_backlog)
11637 			napi->state &= NAPIF_STATE_THREADED;
11638 		else
11639 			____napi_schedule(sd, napi);
11640 	}
11641 
11642 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11643 	local_irq_enable();
11644 
11645 	if (!use_backlog_threads()) {
11646 #ifdef CONFIG_RPS
11647 		remsd = oldsd->rps_ipi_list;
11648 		oldsd->rps_ipi_list = NULL;
11649 #endif
11650 		/* send out pending IPI's on offline CPU */
11651 		net_rps_send_ipi(remsd);
11652 	}
11653 
11654 	/* Process offline CPU's input_pkt_queue */
11655 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11656 		netif_rx(skb);
11657 		rps_input_queue_head_incr(oldsd);
11658 	}
11659 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11660 		netif_rx(skb);
11661 		rps_input_queue_head_incr(oldsd);
11662 	}
11663 
11664 	return 0;
11665 }
11666 
11667 /**
11668  *	netdev_increment_features - increment feature set by one
11669  *	@all: current feature set
11670  *	@one: new feature set
11671  *	@mask: mask feature set
11672  *
11673  *	Computes a new feature set after adding a device with feature set
11674  *	@one to the master device with current feature set @all.  Will not
11675  *	enable anything that is off in @mask. Returns the new feature set.
11676  */
11677 netdev_features_t netdev_increment_features(netdev_features_t all,
11678 	netdev_features_t one, netdev_features_t mask)
11679 {
11680 	if (mask & NETIF_F_HW_CSUM)
11681 		mask |= NETIF_F_CSUM_MASK;
11682 	mask |= NETIF_F_VLAN_CHALLENGED;
11683 
11684 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11685 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11686 
11687 	/* If one device supports hw checksumming, set for all. */
11688 	if (all & NETIF_F_HW_CSUM)
11689 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11690 
11691 	return all;
11692 }
11693 EXPORT_SYMBOL(netdev_increment_features);
11694 
11695 static struct hlist_head * __net_init netdev_create_hash(void)
11696 {
11697 	int i;
11698 	struct hlist_head *hash;
11699 
11700 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11701 	if (hash != NULL)
11702 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11703 			INIT_HLIST_HEAD(&hash[i]);
11704 
11705 	return hash;
11706 }
11707 
11708 /* Initialize per network namespace state */
11709 static int __net_init netdev_init(struct net *net)
11710 {
11711 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11712 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11713 
11714 	INIT_LIST_HEAD(&net->dev_base_head);
11715 
11716 	net->dev_name_head = netdev_create_hash();
11717 	if (net->dev_name_head == NULL)
11718 		goto err_name;
11719 
11720 	net->dev_index_head = netdev_create_hash();
11721 	if (net->dev_index_head == NULL)
11722 		goto err_idx;
11723 
11724 	xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1);
11725 
11726 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11727 
11728 	return 0;
11729 
11730 err_idx:
11731 	kfree(net->dev_name_head);
11732 err_name:
11733 	return -ENOMEM;
11734 }
11735 
11736 /**
11737  *	netdev_drivername - network driver for the device
11738  *	@dev: network device
11739  *
11740  *	Determine network driver for device.
11741  */
11742 const char *netdev_drivername(const struct net_device *dev)
11743 {
11744 	const struct device_driver *driver;
11745 	const struct device *parent;
11746 	const char *empty = "";
11747 
11748 	parent = dev->dev.parent;
11749 	if (!parent)
11750 		return empty;
11751 
11752 	driver = parent->driver;
11753 	if (driver && driver->name)
11754 		return driver->name;
11755 	return empty;
11756 }
11757 
11758 static void __netdev_printk(const char *level, const struct net_device *dev,
11759 			    struct va_format *vaf)
11760 {
11761 	if (dev && dev->dev.parent) {
11762 		dev_printk_emit(level[1] - '0',
11763 				dev->dev.parent,
11764 				"%s %s %s%s: %pV",
11765 				dev_driver_string(dev->dev.parent),
11766 				dev_name(dev->dev.parent),
11767 				netdev_name(dev), netdev_reg_state(dev),
11768 				vaf);
11769 	} else if (dev) {
11770 		printk("%s%s%s: %pV",
11771 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11772 	} else {
11773 		printk("%s(NULL net_device): %pV", level, vaf);
11774 	}
11775 }
11776 
11777 void netdev_printk(const char *level, const struct net_device *dev,
11778 		   const char *format, ...)
11779 {
11780 	struct va_format vaf;
11781 	va_list args;
11782 
11783 	va_start(args, format);
11784 
11785 	vaf.fmt = format;
11786 	vaf.va = &args;
11787 
11788 	__netdev_printk(level, dev, &vaf);
11789 
11790 	va_end(args);
11791 }
11792 EXPORT_SYMBOL(netdev_printk);
11793 
11794 #define define_netdev_printk_level(func, level)			\
11795 void func(const struct net_device *dev, const char *fmt, ...)	\
11796 {								\
11797 	struct va_format vaf;					\
11798 	va_list args;						\
11799 								\
11800 	va_start(args, fmt);					\
11801 								\
11802 	vaf.fmt = fmt;						\
11803 	vaf.va = &args;						\
11804 								\
11805 	__netdev_printk(level, dev, &vaf);			\
11806 								\
11807 	va_end(args);						\
11808 }								\
11809 EXPORT_SYMBOL(func);
11810 
11811 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11812 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11813 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11814 define_netdev_printk_level(netdev_err, KERN_ERR);
11815 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11816 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11817 define_netdev_printk_level(netdev_info, KERN_INFO);
11818 
11819 static void __net_exit netdev_exit(struct net *net)
11820 {
11821 	kfree(net->dev_name_head);
11822 	kfree(net->dev_index_head);
11823 	xa_destroy(&net->dev_by_index);
11824 	if (net != &init_net)
11825 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11826 }
11827 
11828 static struct pernet_operations __net_initdata netdev_net_ops = {
11829 	.init = netdev_init,
11830 	.exit = netdev_exit,
11831 };
11832 
11833 static void __net_exit default_device_exit_net(struct net *net)
11834 {
11835 	struct netdev_name_node *name_node, *tmp;
11836 	struct net_device *dev, *aux;
11837 	/*
11838 	 * Push all migratable network devices back to the
11839 	 * initial network namespace
11840 	 */
11841 	ASSERT_RTNL();
11842 	for_each_netdev_safe(net, dev, aux) {
11843 		int err;
11844 		char fb_name[IFNAMSIZ];
11845 
11846 		/* Ignore unmoveable devices (i.e. loopback) */
11847 		if (dev->features & NETIF_F_NETNS_LOCAL)
11848 			continue;
11849 
11850 		/* Leave virtual devices for the generic cleanup */
11851 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11852 			continue;
11853 
11854 		/* Push remaining network devices to init_net */
11855 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11856 		if (netdev_name_in_use(&init_net, fb_name))
11857 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11858 
11859 		netdev_for_each_altname_safe(dev, name_node, tmp)
11860 			if (netdev_name_in_use(&init_net, name_node->name))
11861 				__netdev_name_node_alt_destroy(name_node);
11862 
11863 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11864 		if (err) {
11865 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11866 				 __func__, dev->name, err);
11867 			BUG();
11868 		}
11869 	}
11870 }
11871 
11872 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11873 {
11874 	/* At exit all network devices most be removed from a network
11875 	 * namespace.  Do this in the reverse order of registration.
11876 	 * Do this across as many network namespaces as possible to
11877 	 * improve batching efficiency.
11878 	 */
11879 	struct net_device *dev;
11880 	struct net *net;
11881 	LIST_HEAD(dev_kill_list);
11882 
11883 	rtnl_lock();
11884 	list_for_each_entry(net, net_list, exit_list) {
11885 		default_device_exit_net(net);
11886 		cond_resched();
11887 	}
11888 
11889 	list_for_each_entry(net, net_list, exit_list) {
11890 		for_each_netdev_reverse(net, dev) {
11891 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11892 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11893 			else
11894 				unregister_netdevice_queue(dev, &dev_kill_list);
11895 		}
11896 	}
11897 	unregister_netdevice_many(&dev_kill_list);
11898 	rtnl_unlock();
11899 }
11900 
11901 static struct pernet_operations __net_initdata default_device_ops = {
11902 	.exit_batch = default_device_exit_batch,
11903 };
11904 
11905 static void __init net_dev_struct_check(void)
11906 {
11907 	/* TX read-mostly hotpath */
11908 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, priv_flags);
11909 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, netdev_ops);
11910 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, header_ops);
11911 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, _tx);
11912 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, real_num_tx_queues);
11913 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, gso_max_size);
11914 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, gso_ipv4_max_size);
11915 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, gso_max_segs);
11916 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, gso_partial_features);
11917 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, num_tc);
11918 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, mtu);
11919 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, needed_headroom);
11920 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, tc_to_txq);
11921 #ifdef CONFIG_XPS
11922 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, xps_maps);
11923 #endif
11924 #ifdef CONFIG_NETFILTER_EGRESS
11925 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, nf_hooks_egress);
11926 #endif
11927 #ifdef CONFIG_NET_XGRESS
11928 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, tcx_egress);
11929 #endif
11930 	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_tx, 160);
11931 
11932 	/* TXRX read-mostly hotpath */
11933 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, lstats);
11934 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, state);
11935 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, flags);
11936 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, hard_header_len);
11937 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, features);
11938 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, ip6_ptr);
11939 	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 46);
11940 
11941 	/* RX read-mostly hotpath */
11942 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ptype_specific);
11943 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ifindex);
11944 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, real_num_rx_queues);
11945 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, _rx);
11946 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_flush_timeout);
11947 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, napi_defer_hard_irqs);
11948 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_max_size);
11949 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_ipv4_max_size);
11950 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, rx_handler);
11951 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, rx_handler_data);
11952 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, nd_net);
11953 #ifdef CONFIG_NETPOLL
11954 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, npinfo);
11955 #endif
11956 #ifdef CONFIG_NET_XGRESS
11957 	CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, tcx_ingress);
11958 #endif
11959 	CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_rx, 104);
11960 }
11961 
11962 /*
11963  *	Initialize the DEV module. At boot time this walks the device list and
11964  *	unhooks any devices that fail to initialise (normally hardware not
11965  *	present) and leaves us with a valid list of present and active devices.
11966  *
11967  */
11968 
11969 /* We allocate 256 pages for each CPU if PAGE_SHIFT is 12 */
11970 #define SYSTEM_PERCPU_PAGE_POOL_SIZE	((1 << 20) / PAGE_SIZE)
11971 
11972 static int net_page_pool_create(int cpuid)
11973 {
11974 #if IS_ENABLED(CONFIG_PAGE_POOL)
11975 	struct page_pool_params page_pool_params = {
11976 		.pool_size = SYSTEM_PERCPU_PAGE_POOL_SIZE,
11977 		.flags = PP_FLAG_SYSTEM_POOL,
11978 		.nid = cpu_to_mem(cpuid),
11979 	};
11980 	struct page_pool *pp_ptr;
11981 
11982 	pp_ptr = page_pool_create_percpu(&page_pool_params, cpuid);
11983 	if (IS_ERR(pp_ptr))
11984 		return -ENOMEM;
11985 
11986 	per_cpu(system_page_pool, cpuid) = pp_ptr;
11987 #endif
11988 	return 0;
11989 }
11990 
11991 static int backlog_napi_should_run(unsigned int cpu)
11992 {
11993 	struct softnet_data *sd = per_cpu_ptr(&softnet_data, cpu);
11994 	struct napi_struct *napi = &sd->backlog;
11995 
11996 	return test_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
11997 }
11998 
11999 static void run_backlog_napi(unsigned int cpu)
12000 {
12001 	struct softnet_data *sd = per_cpu_ptr(&softnet_data, cpu);
12002 
12003 	napi_threaded_poll_loop(&sd->backlog);
12004 }
12005 
12006 static void backlog_napi_setup(unsigned int cpu)
12007 {
12008 	struct softnet_data *sd = per_cpu_ptr(&softnet_data, cpu);
12009 	struct napi_struct *napi = &sd->backlog;
12010 
12011 	napi->thread = this_cpu_read(backlog_napi);
12012 	set_bit(NAPI_STATE_THREADED, &napi->state);
12013 }
12014 
12015 static struct smp_hotplug_thread backlog_threads = {
12016 	.store			= &backlog_napi,
12017 	.thread_should_run	= backlog_napi_should_run,
12018 	.thread_fn		= run_backlog_napi,
12019 	.thread_comm		= "backlog_napi/%u",
12020 	.setup			= backlog_napi_setup,
12021 };
12022 
12023 /*
12024  *       This is called single threaded during boot, so no need
12025  *       to take the rtnl semaphore.
12026  */
12027 static int __init net_dev_init(void)
12028 {
12029 	int i, rc = -ENOMEM;
12030 
12031 	BUG_ON(!dev_boot_phase);
12032 
12033 	net_dev_struct_check();
12034 
12035 	if (dev_proc_init())
12036 		goto out;
12037 
12038 	if (netdev_kobject_init())
12039 		goto out;
12040 
12041 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
12042 		INIT_LIST_HEAD(&ptype_base[i]);
12043 
12044 	if (register_pernet_subsys(&netdev_net_ops))
12045 		goto out;
12046 
12047 	/*
12048 	 *	Initialise the packet receive queues.
12049 	 */
12050 
12051 	for_each_possible_cpu(i) {
12052 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
12053 		struct softnet_data *sd = &per_cpu(softnet_data, i);
12054 
12055 		INIT_WORK(flush, flush_backlog);
12056 
12057 		skb_queue_head_init(&sd->input_pkt_queue);
12058 		skb_queue_head_init(&sd->process_queue);
12059 #ifdef CONFIG_XFRM_OFFLOAD
12060 		skb_queue_head_init(&sd->xfrm_backlog);
12061 #endif
12062 		INIT_LIST_HEAD(&sd->poll_list);
12063 		sd->output_queue_tailp = &sd->output_queue;
12064 #ifdef CONFIG_RPS
12065 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
12066 		sd->cpu = i;
12067 #endif
12068 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
12069 		spin_lock_init(&sd->defer_lock);
12070 
12071 		init_gro_hash(&sd->backlog);
12072 		sd->backlog.poll = process_backlog;
12073 		sd->backlog.weight = weight_p;
12074 		INIT_LIST_HEAD(&sd->backlog.poll_list);
12075 
12076 		if (net_page_pool_create(i))
12077 			goto out;
12078 	}
12079 	if (use_backlog_threads())
12080 		smpboot_register_percpu_thread(&backlog_threads);
12081 
12082 	dev_boot_phase = 0;
12083 
12084 	/* The loopback device is special if any other network devices
12085 	 * is present in a network namespace the loopback device must
12086 	 * be present. Since we now dynamically allocate and free the
12087 	 * loopback device ensure this invariant is maintained by
12088 	 * keeping the loopback device as the first device on the
12089 	 * list of network devices.  Ensuring the loopback devices
12090 	 * is the first device that appears and the last network device
12091 	 * that disappears.
12092 	 */
12093 	if (register_pernet_device(&loopback_net_ops))
12094 		goto out;
12095 
12096 	if (register_pernet_device(&default_device_ops))
12097 		goto out;
12098 
12099 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
12100 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
12101 
12102 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
12103 				       NULL, dev_cpu_dead);
12104 	WARN_ON(rc < 0);
12105 	rc = 0;
12106 
12107 	/* avoid static key IPIs to isolated CPUs */
12108 	if (housekeeping_enabled(HK_TYPE_MISC))
12109 		net_enable_timestamp();
12110 out:
12111 	if (rc < 0) {
12112 		for_each_possible_cpu(i) {
12113 			struct page_pool *pp_ptr;
12114 
12115 			pp_ptr = per_cpu(system_page_pool, i);
12116 			if (!pp_ptr)
12117 				continue;
12118 
12119 			page_pool_destroy(pp_ptr);
12120 			per_cpu(system_page_pool, i) = NULL;
12121 		}
12122 	}
12123 
12124 	return rc;
12125 }
12126 
12127 subsys_initcall(net_dev_init);
12128