xref: /linux/net/core/dev.c (revision e3234e547a4db0572e271e490d044bdb4cb7233b)
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/mm.h>
81 #include <linux/mutex.h>
82 #include <linux/rwsem.h>
83 #include <linux/string.h>
84 #include <linux/mm.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/errno.h>
88 #include <linux/interrupt.h>
89 #include <linux/if_ether.h>
90 #include <linux/netdevice.h>
91 #include <linux/etherdevice.h>
92 #include <linux/ethtool.h>
93 #include <linux/skbuff.h>
94 #include <linux/kthread.h>
95 #include <linux/bpf.h>
96 #include <linux/bpf_trace.h>
97 #include <net/net_namespace.h>
98 #include <net/sock.h>
99 #include <net/busy_poll.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/stat.h>
102 #include <net/dsa.h>
103 #include <net/dst.h>
104 #include <net/dst_metadata.h>
105 #include <net/gro.h>
106 #include <net/pkt_sched.h>
107 #include <net/pkt_cls.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <net/tcx.h>
111 #include <linux/highmem.h>
112 #include <linux/init.h>
113 #include <linux/module.h>
114 #include <linux/netpoll.h>
115 #include <linux/rcupdate.h>
116 #include <linux/delay.h>
117 #include <net/iw_handler.h>
118 #include <asm/current.h>
119 #include <linux/audit.h>
120 #include <linux/dmaengine.h>
121 #include <linux/err.h>
122 #include <linux/ctype.h>
123 #include <linux/if_arp.h>
124 #include <linux/if_vlan.h>
125 #include <linux/ip.h>
126 #include <net/ip.h>
127 #include <net/mpls.h>
128 #include <linux/ipv6.h>
129 #include <linux/in.h>
130 #include <linux/jhash.h>
131 #include <linux/random.h>
132 #include <trace/events/napi.h>
133 #include <trace/events/net.h>
134 #include <trace/events/skb.h>
135 #include <trace/events/qdisc.h>
136 #include <trace/events/xdp.h>
137 #include <linux/inetdevice.h>
138 #include <linux/cpu_rmap.h>
139 #include <linux/static_key.h>
140 #include <linux/hashtable.h>
141 #include <linux/vmalloc.h>
142 #include <linux/if_macvlan.h>
143 #include <linux/errqueue.h>
144 #include <linux/hrtimer.h>
145 #include <linux/netfilter_netdev.h>
146 #include <linux/crash_dump.h>
147 #include <linux/sctp.h>
148 #include <net/udp_tunnel.h>
149 #include <linux/net_namespace.h>
150 #include <linux/indirect_call_wrapper.h>
151 #include <net/devlink.h>
152 #include <linux/pm_runtime.h>
153 #include <linux/prandom.h>
154 #include <linux/once_lite.h>
155 #include <net/netdev_rx_queue.h>
156 
157 #include "dev.h"
158 #include "net-sysfs.h"
159 
160 static DEFINE_SPINLOCK(ptype_lock);
161 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
162 struct list_head ptype_all __read_mostly;	/* Taps */
163 
164 static int netif_rx_internal(struct sk_buff *skb);
165 static int call_netdevice_notifiers_extack(unsigned long val,
166 					   struct net_device *dev,
167 					   struct netlink_ext_ack *extack);
168 static struct napi_struct *napi_by_id(unsigned int napi_id);
169 
170 /*
171  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
172  * semaphore.
173  *
174  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
175  *
176  * Writers must hold the rtnl semaphore while they loop through the
177  * dev_base_head list, and hold dev_base_lock for writing when they do the
178  * actual updates.  This allows pure readers to access the list even
179  * while a writer is preparing to update it.
180  *
181  * To put it another way, dev_base_lock is held for writing only to
182  * protect against pure readers; the rtnl semaphore provides the
183  * protection against other writers.
184  *
185  * See, for example usages, register_netdevice() and
186  * unregister_netdevice(), which must be called with the rtnl
187  * semaphore held.
188  */
189 DEFINE_RWLOCK(dev_base_lock);
190 EXPORT_SYMBOL(dev_base_lock);
191 
192 static DEFINE_MUTEX(ifalias_mutex);
193 
194 /* protects napi_hash addition/deletion and napi_gen_id */
195 static DEFINE_SPINLOCK(napi_hash_lock);
196 
197 static unsigned int napi_gen_id = NR_CPUS;
198 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
199 
200 static DECLARE_RWSEM(devnet_rename_sem);
201 
202 static inline void dev_base_seq_inc(struct net *net)
203 {
204 	while (++net->dev_base_seq == 0)
205 		;
206 }
207 
208 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
209 {
210 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
211 
212 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
213 }
214 
215 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
216 {
217 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
218 }
219 
220 static inline void rps_lock_irqsave(struct softnet_data *sd,
221 				    unsigned long *flags)
222 {
223 	if (IS_ENABLED(CONFIG_RPS))
224 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
225 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
226 		local_irq_save(*flags);
227 }
228 
229 static inline void rps_lock_irq_disable(struct softnet_data *sd)
230 {
231 	if (IS_ENABLED(CONFIG_RPS))
232 		spin_lock_irq(&sd->input_pkt_queue.lock);
233 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
234 		local_irq_disable();
235 }
236 
237 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
238 					  unsigned long *flags)
239 {
240 	if (IS_ENABLED(CONFIG_RPS))
241 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
242 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
243 		local_irq_restore(*flags);
244 }
245 
246 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
247 {
248 	if (IS_ENABLED(CONFIG_RPS))
249 		spin_unlock_irq(&sd->input_pkt_queue.lock);
250 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
251 		local_irq_enable();
252 }
253 
254 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
255 						       const char *name)
256 {
257 	struct netdev_name_node *name_node;
258 
259 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
260 	if (!name_node)
261 		return NULL;
262 	INIT_HLIST_NODE(&name_node->hlist);
263 	name_node->dev = dev;
264 	name_node->name = name;
265 	return name_node;
266 }
267 
268 static struct netdev_name_node *
269 netdev_name_node_head_alloc(struct net_device *dev)
270 {
271 	struct netdev_name_node *name_node;
272 
273 	name_node = netdev_name_node_alloc(dev, dev->name);
274 	if (!name_node)
275 		return NULL;
276 	INIT_LIST_HEAD(&name_node->list);
277 	return name_node;
278 }
279 
280 static void netdev_name_node_free(struct netdev_name_node *name_node)
281 {
282 	kfree(name_node);
283 }
284 
285 static void netdev_name_node_add(struct net *net,
286 				 struct netdev_name_node *name_node)
287 {
288 	hlist_add_head_rcu(&name_node->hlist,
289 			   dev_name_hash(net, name_node->name));
290 }
291 
292 static void netdev_name_node_del(struct netdev_name_node *name_node)
293 {
294 	hlist_del_rcu(&name_node->hlist);
295 }
296 
297 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
298 							const char *name)
299 {
300 	struct hlist_head *head = dev_name_hash(net, name);
301 	struct netdev_name_node *name_node;
302 
303 	hlist_for_each_entry(name_node, head, hlist)
304 		if (!strcmp(name_node->name, name))
305 			return name_node;
306 	return NULL;
307 }
308 
309 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
310 							    const char *name)
311 {
312 	struct hlist_head *head = dev_name_hash(net, name);
313 	struct netdev_name_node *name_node;
314 
315 	hlist_for_each_entry_rcu(name_node, head, hlist)
316 		if (!strcmp(name_node->name, name))
317 			return name_node;
318 	return NULL;
319 }
320 
321 bool netdev_name_in_use(struct net *net, const char *name)
322 {
323 	return netdev_name_node_lookup(net, name);
324 }
325 EXPORT_SYMBOL(netdev_name_in_use);
326 
327 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
328 {
329 	struct netdev_name_node *name_node;
330 	struct net *net = dev_net(dev);
331 
332 	name_node = netdev_name_node_lookup(net, name);
333 	if (name_node)
334 		return -EEXIST;
335 	name_node = netdev_name_node_alloc(dev, name);
336 	if (!name_node)
337 		return -ENOMEM;
338 	netdev_name_node_add(net, name_node);
339 	/* The node that holds dev->name acts as a head of per-device list. */
340 	list_add_tail(&name_node->list, &dev->name_node->list);
341 
342 	return 0;
343 }
344 
345 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
346 {
347 	list_del(&name_node->list);
348 	kfree(name_node->name);
349 	netdev_name_node_free(name_node);
350 }
351 
352 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
353 {
354 	struct netdev_name_node *name_node;
355 	struct net *net = dev_net(dev);
356 
357 	name_node = netdev_name_node_lookup(net, name);
358 	if (!name_node)
359 		return -ENOENT;
360 	/* lookup might have found our primary name or a name belonging
361 	 * to another device.
362 	 */
363 	if (name_node == dev->name_node || name_node->dev != dev)
364 		return -EINVAL;
365 
366 	netdev_name_node_del(name_node);
367 	synchronize_rcu();
368 	__netdev_name_node_alt_destroy(name_node);
369 
370 	return 0;
371 }
372 
373 static void netdev_name_node_alt_flush(struct net_device *dev)
374 {
375 	struct netdev_name_node *name_node, *tmp;
376 
377 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
378 		__netdev_name_node_alt_destroy(name_node);
379 }
380 
381 /* Device list insertion */
382 static void list_netdevice(struct net_device *dev)
383 {
384 	struct netdev_name_node *name_node;
385 	struct net *net = dev_net(dev);
386 
387 	ASSERT_RTNL();
388 
389 	write_lock(&dev_base_lock);
390 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
391 	netdev_name_node_add(net, dev->name_node);
392 	hlist_add_head_rcu(&dev->index_hlist,
393 			   dev_index_hash(net, dev->ifindex));
394 	write_unlock(&dev_base_lock);
395 
396 	netdev_for_each_altname(dev, name_node)
397 		netdev_name_node_add(net, name_node);
398 
399 	/* We reserved the ifindex, this can't fail */
400 	WARN_ON(xa_store(&net->dev_by_index, dev->ifindex, dev, GFP_KERNEL));
401 
402 	dev_base_seq_inc(net);
403 }
404 
405 /* Device list removal
406  * caller must respect a RCU grace period before freeing/reusing dev
407  */
408 static void unlist_netdevice(struct net_device *dev, bool lock)
409 {
410 	struct netdev_name_node *name_node;
411 	struct net *net = dev_net(dev);
412 
413 	ASSERT_RTNL();
414 
415 	xa_erase(&net->dev_by_index, dev->ifindex);
416 
417 	netdev_for_each_altname(dev, name_node)
418 		netdev_name_node_del(name_node);
419 
420 	/* Unlink dev from the device chain */
421 	if (lock)
422 		write_lock(&dev_base_lock);
423 	list_del_rcu(&dev->dev_list);
424 	netdev_name_node_del(dev->name_node);
425 	hlist_del_rcu(&dev->index_hlist);
426 	if (lock)
427 		write_unlock(&dev_base_lock);
428 
429 	dev_base_seq_inc(dev_net(dev));
430 }
431 
432 /*
433  *	Our notifier list
434  */
435 
436 static RAW_NOTIFIER_HEAD(netdev_chain);
437 
438 /*
439  *	Device drivers call our routines to queue packets here. We empty the
440  *	queue in the local softnet handler.
441  */
442 
443 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
444 EXPORT_PER_CPU_SYMBOL(softnet_data);
445 
446 #ifdef CONFIG_LOCKDEP
447 /*
448  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
449  * according to dev->type
450  */
451 static const unsigned short netdev_lock_type[] = {
452 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
453 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
454 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
455 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
456 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
457 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
458 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
459 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
460 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
461 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
462 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
463 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
464 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
465 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
466 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
467 
468 static const char *const netdev_lock_name[] = {
469 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
470 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
471 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
472 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
473 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
474 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
475 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
476 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
477 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
478 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
479 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
480 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
481 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
482 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
483 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
484 
485 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
486 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
487 
488 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
489 {
490 	int i;
491 
492 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
493 		if (netdev_lock_type[i] == dev_type)
494 			return i;
495 	/* the last key is used by default */
496 	return ARRAY_SIZE(netdev_lock_type) - 1;
497 }
498 
499 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
500 						 unsigned short dev_type)
501 {
502 	int i;
503 
504 	i = netdev_lock_pos(dev_type);
505 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
506 				   netdev_lock_name[i]);
507 }
508 
509 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
510 {
511 	int i;
512 
513 	i = netdev_lock_pos(dev->type);
514 	lockdep_set_class_and_name(&dev->addr_list_lock,
515 				   &netdev_addr_lock_key[i],
516 				   netdev_lock_name[i]);
517 }
518 #else
519 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
520 						 unsigned short dev_type)
521 {
522 }
523 
524 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
525 {
526 }
527 #endif
528 
529 /*******************************************************************************
530  *
531  *		Protocol management and registration routines
532  *
533  *******************************************************************************/
534 
535 
536 /*
537  *	Add a protocol ID to the list. Now that the input handler is
538  *	smarter we can dispense with all the messy stuff that used to be
539  *	here.
540  *
541  *	BEWARE!!! Protocol handlers, mangling input packets,
542  *	MUST BE last in hash buckets and checking protocol handlers
543  *	MUST start from promiscuous ptype_all chain in net_bh.
544  *	It is true now, do not change it.
545  *	Explanation follows: if protocol handler, mangling packet, will
546  *	be the first on list, it is not able to sense, that packet
547  *	is cloned and should be copied-on-write, so that it will
548  *	change it and subsequent readers will get broken packet.
549  *							--ANK (980803)
550  */
551 
552 static inline struct list_head *ptype_head(const struct packet_type *pt)
553 {
554 	if (pt->type == htons(ETH_P_ALL))
555 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
556 	else
557 		return pt->dev ? &pt->dev->ptype_specific :
558 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
559 }
560 
561 /**
562  *	dev_add_pack - add packet handler
563  *	@pt: packet type declaration
564  *
565  *	Add a protocol handler to the networking stack. The passed &packet_type
566  *	is linked into kernel lists and may not be freed until it has been
567  *	removed from the kernel lists.
568  *
569  *	This call does not sleep therefore it can not
570  *	guarantee all CPU's that are in middle of receiving packets
571  *	will see the new packet type (until the next received packet).
572  */
573 
574 void dev_add_pack(struct packet_type *pt)
575 {
576 	struct list_head *head = ptype_head(pt);
577 
578 	spin_lock(&ptype_lock);
579 	list_add_rcu(&pt->list, head);
580 	spin_unlock(&ptype_lock);
581 }
582 EXPORT_SYMBOL(dev_add_pack);
583 
584 /**
585  *	__dev_remove_pack	 - remove packet handler
586  *	@pt: packet type declaration
587  *
588  *	Remove a protocol handler that was previously added to the kernel
589  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
590  *	from the kernel lists and can be freed or reused once this function
591  *	returns.
592  *
593  *      The packet type might still be in use by receivers
594  *	and must not be freed until after all the CPU's have gone
595  *	through a quiescent state.
596  */
597 void __dev_remove_pack(struct packet_type *pt)
598 {
599 	struct list_head *head = ptype_head(pt);
600 	struct packet_type *pt1;
601 
602 	spin_lock(&ptype_lock);
603 
604 	list_for_each_entry(pt1, head, list) {
605 		if (pt == pt1) {
606 			list_del_rcu(&pt->list);
607 			goto out;
608 		}
609 	}
610 
611 	pr_warn("dev_remove_pack: %p not found\n", pt);
612 out:
613 	spin_unlock(&ptype_lock);
614 }
615 EXPORT_SYMBOL(__dev_remove_pack);
616 
617 /**
618  *	dev_remove_pack	 - remove packet handler
619  *	@pt: packet type declaration
620  *
621  *	Remove a protocol handler that was previously added to the kernel
622  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
623  *	from the kernel lists and can be freed or reused once this function
624  *	returns.
625  *
626  *	This call sleeps to guarantee that no CPU is looking at the packet
627  *	type after return.
628  */
629 void dev_remove_pack(struct packet_type *pt)
630 {
631 	__dev_remove_pack(pt);
632 
633 	synchronize_net();
634 }
635 EXPORT_SYMBOL(dev_remove_pack);
636 
637 
638 /*******************************************************************************
639  *
640  *			    Device Interface Subroutines
641  *
642  *******************************************************************************/
643 
644 /**
645  *	dev_get_iflink	- get 'iflink' value of a interface
646  *	@dev: targeted interface
647  *
648  *	Indicates the ifindex the interface is linked to.
649  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
650  */
651 
652 int dev_get_iflink(const struct net_device *dev)
653 {
654 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
655 		return dev->netdev_ops->ndo_get_iflink(dev);
656 
657 	return dev->ifindex;
658 }
659 EXPORT_SYMBOL(dev_get_iflink);
660 
661 /**
662  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
663  *	@dev: targeted interface
664  *	@skb: The packet.
665  *
666  *	For better visibility of tunnel traffic OVS needs to retrieve
667  *	egress tunnel information for a packet. Following API allows
668  *	user to get this info.
669  */
670 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
671 {
672 	struct ip_tunnel_info *info;
673 
674 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
675 		return -EINVAL;
676 
677 	info = skb_tunnel_info_unclone(skb);
678 	if (!info)
679 		return -ENOMEM;
680 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
681 		return -EINVAL;
682 
683 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
684 }
685 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
686 
687 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
688 {
689 	int k = stack->num_paths++;
690 
691 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
692 		return NULL;
693 
694 	return &stack->path[k];
695 }
696 
697 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
698 			  struct net_device_path_stack *stack)
699 {
700 	const struct net_device *last_dev;
701 	struct net_device_path_ctx ctx = {
702 		.dev	= dev,
703 	};
704 	struct net_device_path *path;
705 	int ret = 0;
706 
707 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
708 	stack->num_paths = 0;
709 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
710 		last_dev = ctx.dev;
711 		path = dev_fwd_path(stack);
712 		if (!path)
713 			return -1;
714 
715 		memset(path, 0, sizeof(struct net_device_path));
716 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
717 		if (ret < 0)
718 			return -1;
719 
720 		if (WARN_ON_ONCE(last_dev == ctx.dev))
721 			return -1;
722 	}
723 
724 	if (!ctx.dev)
725 		return ret;
726 
727 	path = dev_fwd_path(stack);
728 	if (!path)
729 		return -1;
730 	path->type = DEV_PATH_ETHERNET;
731 	path->dev = ctx.dev;
732 
733 	return ret;
734 }
735 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
736 
737 /**
738  *	__dev_get_by_name	- find a device by its name
739  *	@net: the applicable net namespace
740  *	@name: name to find
741  *
742  *	Find an interface by name. Must be called under RTNL semaphore
743  *	or @dev_base_lock. If the name is found a pointer to the device
744  *	is returned. If the name is not found then %NULL is returned. The
745  *	reference counters are not incremented so the caller must be
746  *	careful with locks.
747  */
748 
749 struct net_device *__dev_get_by_name(struct net *net, const char *name)
750 {
751 	struct netdev_name_node *node_name;
752 
753 	node_name = netdev_name_node_lookup(net, name);
754 	return node_name ? node_name->dev : NULL;
755 }
756 EXPORT_SYMBOL(__dev_get_by_name);
757 
758 /**
759  * dev_get_by_name_rcu	- find a device by its name
760  * @net: the applicable net namespace
761  * @name: name to find
762  *
763  * Find an interface by name.
764  * If the name is found a pointer to the device is returned.
765  * If the name is not found then %NULL is returned.
766  * The reference counters are not incremented so the caller must be
767  * careful with locks. The caller must hold RCU lock.
768  */
769 
770 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
771 {
772 	struct netdev_name_node *node_name;
773 
774 	node_name = netdev_name_node_lookup_rcu(net, name);
775 	return node_name ? node_name->dev : NULL;
776 }
777 EXPORT_SYMBOL(dev_get_by_name_rcu);
778 
779 /* Deprecated for new users, call netdev_get_by_name() instead */
780 struct net_device *dev_get_by_name(struct net *net, const char *name)
781 {
782 	struct net_device *dev;
783 
784 	rcu_read_lock();
785 	dev = dev_get_by_name_rcu(net, name);
786 	dev_hold(dev);
787 	rcu_read_unlock();
788 	return dev;
789 }
790 EXPORT_SYMBOL(dev_get_by_name);
791 
792 /**
793  *	netdev_get_by_name() - find a device by its name
794  *	@net: the applicable net namespace
795  *	@name: name to find
796  *	@tracker: tracking object for the acquired reference
797  *	@gfp: allocation flags for the tracker
798  *
799  *	Find an interface by name. This can be called from any
800  *	context and does its own locking. The returned handle has
801  *	the usage count incremented and the caller must use netdev_put() to
802  *	release it when it is no longer needed. %NULL is returned if no
803  *	matching device is found.
804  */
805 struct net_device *netdev_get_by_name(struct net *net, const char *name,
806 				      netdevice_tracker *tracker, gfp_t gfp)
807 {
808 	struct net_device *dev;
809 
810 	dev = dev_get_by_name(net, name);
811 	if (dev)
812 		netdev_tracker_alloc(dev, tracker, gfp);
813 	return dev;
814 }
815 EXPORT_SYMBOL(netdev_get_by_name);
816 
817 /**
818  *	__dev_get_by_index - find a device by its ifindex
819  *	@net: the applicable net namespace
820  *	@ifindex: index of device
821  *
822  *	Search for an interface by index. Returns %NULL if the device
823  *	is not found or a pointer to the device. The device has not
824  *	had its reference counter increased so the caller must be careful
825  *	about locking. The caller must hold either the RTNL semaphore
826  *	or @dev_base_lock.
827  */
828 
829 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
830 {
831 	struct net_device *dev;
832 	struct hlist_head *head = dev_index_hash(net, ifindex);
833 
834 	hlist_for_each_entry(dev, head, index_hlist)
835 		if (dev->ifindex == ifindex)
836 			return dev;
837 
838 	return NULL;
839 }
840 EXPORT_SYMBOL(__dev_get_by_index);
841 
842 /**
843  *	dev_get_by_index_rcu - find a device by its ifindex
844  *	@net: the applicable net namespace
845  *	@ifindex: index of device
846  *
847  *	Search for an interface by index. Returns %NULL if the device
848  *	is not found or a pointer to the device. The device has not
849  *	had its reference counter increased so the caller must be careful
850  *	about locking. The caller must hold RCU lock.
851  */
852 
853 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
854 {
855 	struct net_device *dev;
856 	struct hlist_head *head = dev_index_hash(net, ifindex);
857 
858 	hlist_for_each_entry_rcu(dev, head, index_hlist)
859 		if (dev->ifindex == ifindex)
860 			return dev;
861 
862 	return NULL;
863 }
864 EXPORT_SYMBOL(dev_get_by_index_rcu);
865 
866 /* Deprecated for new users, call netdev_get_by_index() instead */
867 struct net_device *dev_get_by_index(struct net *net, int ifindex)
868 {
869 	struct net_device *dev;
870 
871 	rcu_read_lock();
872 	dev = dev_get_by_index_rcu(net, ifindex);
873 	dev_hold(dev);
874 	rcu_read_unlock();
875 	return dev;
876 }
877 EXPORT_SYMBOL(dev_get_by_index);
878 
879 /**
880  *	netdev_get_by_index() - find a device by its ifindex
881  *	@net: the applicable net namespace
882  *	@ifindex: index of device
883  *	@tracker: tracking object for the acquired reference
884  *	@gfp: allocation flags for the tracker
885  *
886  *	Search for an interface by index. Returns NULL if the device
887  *	is not found or a pointer to the device. The device returned has
888  *	had a reference added and the pointer is safe until the user calls
889  *	netdev_put() to indicate they have finished with it.
890  */
891 struct net_device *netdev_get_by_index(struct net *net, int ifindex,
892 				       netdevice_tracker *tracker, gfp_t gfp)
893 {
894 	struct net_device *dev;
895 
896 	dev = dev_get_by_index(net, ifindex);
897 	if (dev)
898 		netdev_tracker_alloc(dev, tracker, gfp);
899 	return dev;
900 }
901 EXPORT_SYMBOL(netdev_get_by_index);
902 
903 /**
904  *	dev_get_by_napi_id - find a device by napi_id
905  *	@napi_id: ID of the NAPI struct
906  *
907  *	Search for an interface by NAPI ID. Returns %NULL if the device
908  *	is not found or a pointer to the device. The device has not had
909  *	its reference counter increased so the caller must be careful
910  *	about locking. The caller must hold RCU lock.
911  */
912 
913 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
914 {
915 	struct napi_struct *napi;
916 
917 	WARN_ON_ONCE(!rcu_read_lock_held());
918 
919 	if (napi_id < MIN_NAPI_ID)
920 		return NULL;
921 
922 	napi = napi_by_id(napi_id);
923 
924 	return napi ? napi->dev : NULL;
925 }
926 EXPORT_SYMBOL(dev_get_by_napi_id);
927 
928 /**
929  *	netdev_get_name - get a netdevice name, knowing its ifindex.
930  *	@net: network namespace
931  *	@name: a pointer to the buffer where the name will be stored.
932  *	@ifindex: the ifindex of the interface to get the name from.
933  */
934 int netdev_get_name(struct net *net, char *name, int ifindex)
935 {
936 	struct net_device *dev;
937 	int ret;
938 
939 	down_read(&devnet_rename_sem);
940 	rcu_read_lock();
941 
942 	dev = dev_get_by_index_rcu(net, ifindex);
943 	if (!dev) {
944 		ret = -ENODEV;
945 		goto out;
946 	}
947 
948 	strcpy(name, dev->name);
949 
950 	ret = 0;
951 out:
952 	rcu_read_unlock();
953 	up_read(&devnet_rename_sem);
954 	return ret;
955 }
956 
957 /**
958  *	dev_getbyhwaddr_rcu - find a device by its hardware address
959  *	@net: the applicable net namespace
960  *	@type: media type of device
961  *	@ha: hardware address
962  *
963  *	Search for an interface by MAC address. Returns NULL if the device
964  *	is not found or a pointer to the device.
965  *	The caller must hold RCU or RTNL.
966  *	The returned device has not had its ref count increased
967  *	and the caller must therefore be careful about locking
968  *
969  */
970 
971 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
972 				       const char *ha)
973 {
974 	struct net_device *dev;
975 
976 	for_each_netdev_rcu(net, dev)
977 		if (dev->type == type &&
978 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
979 			return dev;
980 
981 	return NULL;
982 }
983 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
984 
985 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
986 {
987 	struct net_device *dev, *ret = NULL;
988 
989 	rcu_read_lock();
990 	for_each_netdev_rcu(net, dev)
991 		if (dev->type == type) {
992 			dev_hold(dev);
993 			ret = dev;
994 			break;
995 		}
996 	rcu_read_unlock();
997 	return ret;
998 }
999 EXPORT_SYMBOL(dev_getfirstbyhwtype);
1000 
1001 /**
1002  *	__dev_get_by_flags - find any device with given flags
1003  *	@net: the applicable net namespace
1004  *	@if_flags: IFF_* values
1005  *	@mask: bitmask of bits in if_flags to check
1006  *
1007  *	Search for any interface with the given flags. Returns NULL if a device
1008  *	is not found or a pointer to the device. Must be called inside
1009  *	rtnl_lock(), and result refcount is unchanged.
1010  */
1011 
1012 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1013 				      unsigned short mask)
1014 {
1015 	struct net_device *dev, *ret;
1016 
1017 	ASSERT_RTNL();
1018 
1019 	ret = NULL;
1020 	for_each_netdev(net, dev) {
1021 		if (((dev->flags ^ if_flags) & mask) == 0) {
1022 			ret = dev;
1023 			break;
1024 		}
1025 	}
1026 	return ret;
1027 }
1028 EXPORT_SYMBOL(__dev_get_by_flags);
1029 
1030 /**
1031  *	dev_valid_name - check if name is okay for network device
1032  *	@name: name string
1033  *
1034  *	Network device names need to be valid file names to
1035  *	allow sysfs to work.  We also disallow any kind of
1036  *	whitespace.
1037  */
1038 bool dev_valid_name(const char *name)
1039 {
1040 	if (*name == '\0')
1041 		return false;
1042 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1043 		return false;
1044 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1045 		return false;
1046 
1047 	while (*name) {
1048 		if (*name == '/' || *name == ':' || isspace(*name))
1049 			return false;
1050 		name++;
1051 	}
1052 	return true;
1053 }
1054 EXPORT_SYMBOL(dev_valid_name);
1055 
1056 /**
1057  *	__dev_alloc_name - allocate a name for a device
1058  *	@net: network namespace to allocate the device name in
1059  *	@name: name format string
1060  *	@res: result name string
1061  *
1062  *	Passed a format string - eg "lt%d" it will try and find a suitable
1063  *	id. It scans list of devices to build up a free map, then chooses
1064  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1065  *	while allocating the name and adding the device in order to avoid
1066  *	duplicates.
1067  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1068  *	Returns the number of the unit assigned or a negative errno code.
1069  */
1070 
1071 static int __dev_alloc_name(struct net *net, const char *name, char *res)
1072 {
1073 	int i = 0;
1074 	const char *p;
1075 	const int max_netdevices = 8*PAGE_SIZE;
1076 	unsigned long *inuse;
1077 	struct net_device *d;
1078 	char buf[IFNAMSIZ];
1079 
1080 	/* Verify the string as this thing may have come from the user.
1081 	 * There must be one "%d" and no other "%" characters.
1082 	 */
1083 	p = strchr(name, '%');
1084 	if (!p || p[1] != 'd' || strchr(p + 2, '%'))
1085 		return -EINVAL;
1086 
1087 	/* Use one page as a bit array of possible slots */
1088 	inuse = bitmap_zalloc(max_netdevices, GFP_ATOMIC);
1089 	if (!inuse)
1090 		return -ENOMEM;
1091 
1092 	for_each_netdev(net, d) {
1093 		struct netdev_name_node *name_node;
1094 
1095 		netdev_for_each_altname(d, name_node) {
1096 			if (!sscanf(name_node->name, name, &i))
1097 				continue;
1098 			if (i < 0 || i >= max_netdevices)
1099 				continue;
1100 
1101 			/* avoid cases where sscanf is not exact inverse of printf */
1102 			snprintf(buf, IFNAMSIZ, name, i);
1103 			if (!strncmp(buf, name_node->name, IFNAMSIZ))
1104 				__set_bit(i, inuse);
1105 		}
1106 		if (!sscanf(d->name, name, &i))
1107 			continue;
1108 		if (i < 0 || i >= max_netdevices)
1109 			continue;
1110 
1111 		/* avoid cases where sscanf is not exact inverse of printf */
1112 		snprintf(buf, IFNAMSIZ, name, i);
1113 		if (!strncmp(buf, d->name, IFNAMSIZ))
1114 			__set_bit(i, inuse);
1115 	}
1116 
1117 	i = find_first_zero_bit(inuse, max_netdevices);
1118 	bitmap_free(inuse);
1119 	if (i == max_netdevices)
1120 		return -ENFILE;
1121 
1122 	/* 'res' and 'name' could overlap, use 'buf' as an intermediate buffer */
1123 	strscpy(buf, name, IFNAMSIZ);
1124 	snprintf(res, IFNAMSIZ, buf, i);
1125 	return i;
1126 }
1127 
1128 /* Returns negative errno or allocated unit id (see __dev_alloc_name()) */
1129 static int dev_prep_valid_name(struct net *net, struct net_device *dev,
1130 			       const char *want_name, char *out_name,
1131 			       int dup_errno)
1132 {
1133 	if (!dev_valid_name(want_name))
1134 		return -EINVAL;
1135 
1136 	if (strchr(want_name, '%'))
1137 		return __dev_alloc_name(net, want_name, out_name);
1138 
1139 	if (netdev_name_in_use(net, want_name))
1140 		return -dup_errno;
1141 	if (out_name != want_name)
1142 		strscpy(out_name, want_name, IFNAMSIZ);
1143 	return 0;
1144 }
1145 
1146 /**
1147  *	dev_alloc_name - allocate a name for a device
1148  *	@dev: device
1149  *	@name: name format string
1150  *
1151  *	Passed a format string - eg "lt%d" it will try and find a suitable
1152  *	id. It scans list of devices to build up a free map, then chooses
1153  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1154  *	while allocating the name and adding the device in order to avoid
1155  *	duplicates.
1156  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1157  *	Returns the number of the unit assigned or a negative errno code.
1158  */
1159 
1160 int dev_alloc_name(struct net_device *dev, const char *name)
1161 {
1162 	return dev_prep_valid_name(dev_net(dev), dev, name, dev->name, ENFILE);
1163 }
1164 EXPORT_SYMBOL(dev_alloc_name);
1165 
1166 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1167 			      const char *name)
1168 {
1169 	int ret;
1170 
1171 	ret = dev_prep_valid_name(net, dev, name, dev->name, EEXIST);
1172 	return ret < 0 ? ret : 0;
1173 }
1174 
1175 /**
1176  *	dev_change_name - change name of a device
1177  *	@dev: device
1178  *	@newname: name (or format string) must be at least IFNAMSIZ
1179  *
1180  *	Change name of a device, can pass format strings "eth%d".
1181  *	for wildcarding.
1182  */
1183 int dev_change_name(struct net_device *dev, const char *newname)
1184 {
1185 	unsigned char old_assign_type;
1186 	char oldname[IFNAMSIZ];
1187 	int err = 0;
1188 	int ret;
1189 	struct net *net;
1190 
1191 	ASSERT_RTNL();
1192 	BUG_ON(!dev_net(dev));
1193 
1194 	net = dev_net(dev);
1195 
1196 	down_write(&devnet_rename_sem);
1197 
1198 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1199 		up_write(&devnet_rename_sem);
1200 		return 0;
1201 	}
1202 
1203 	memcpy(oldname, dev->name, IFNAMSIZ);
1204 
1205 	err = dev_get_valid_name(net, dev, newname);
1206 	if (err < 0) {
1207 		up_write(&devnet_rename_sem);
1208 		return err;
1209 	}
1210 
1211 	if (oldname[0] && !strchr(oldname, '%'))
1212 		netdev_info(dev, "renamed from %s%s\n", oldname,
1213 			    dev->flags & IFF_UP ? " (while UP)" : "");
1214 
1215 	old_assign_type = dev->name_assign_type;
1216 	dev->name_assign_type = NET_NAME_RENAMED;
1217 
1218 rollback:
1219 	ret = device_rename(&dev->dev, dev->name);
1220 	if (ret) {
1221 		memcpy(dev->name, oldname, IFNAMSIZ);
1222 		dev->name_assign_type = old_assign_type;
1223 		up_write(&devnet_rename_sem);
1224 		return ret;
1225 	}
1226 
1227 	up_write(&devnet_rename_sem);
1228 
1229 	netdev_adjacent_rename_links(dev, oldname);
1230 
1231 	write_lock(&dev_base_lock);
1232 	netdev_name_node_del(dev->name_node);
1233 	write_unlock(&dev_base_lock);
1234 
1235 	synchronize_rcu();
1236 
1237 	write_lock(&dev_base_lock);
1238 	netdev_name_node_add(net, dev->name_node);
1239 	write_unlock(&dev_base_lock);
1240 
1241 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1242 	ret = notifier_to_errno(ret);
1243 
1244 	if (ret) {
1245 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1246 		if (err >= 0) {
1247 			err = ret;
1248 			down_write(&devnet_rename_sem);
1249 			memcpy(dev->name, oldname, IFNAMSIZ);
1250 			memcpy(oldname, newname, IFNAMSIZ);
1251 			dev->name_assign_type = old_assign_type;
1252 			old_assign_type = NET_NAME_RENAMED;
1253 			goto rollback;
1254 		} else {
1255 			netdev_err(dev, "name change rollback failed: %d\n",
1256 				   ret);
1257 		}
1258 	}
1259 
1260 	return err;
1261 }
1262 
1263 /**
1264  *	dev_set_alias - change ifalias of a device
1265  *	@dev: device
1266  *	@alias: name up to IFALIASZ
1267  *	@len: limit of bytes to copy from info
1268  *
1269  *	Set ifalias for a device,
1270  */
1271 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1272 {
1273 	struct dev_ifalias *new_alias = NULL;
1274 
1275 	if (len >= IFALIASZ)
1276 		return -EINVAL;
1277 
1278 	if (len) {
1279 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1280 		if (!new_alias)
1281 			return -ENOMEM;
1282 
1283 		memcpy(new_alias->ifalias, alias, len);
1284 		new_alias->ifalias[len] = 0;
1285 	}
1286 
1287 	mutex_lock(&ifalias_mutex);
1288 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1289 					mutex_is_locked(&ifalias_mutex));
1290 	mutex_unlock(&ifalias_mutex);
1291 
1292 	if (new_alias)
1293 		kfree_rcu(new_alias, rcuhead);
1294 
1295 	return len;
1296 }
1297 EXPORT_SYMBOL(dev_set_alias);
1298 
1299 /**
1300  *	dev_get_alias - get ifalias of a device
1301  *	@dev: device
1302  *	@name: buffer to store name of ifalias
1303  *	@len: size of buffer
1304  *
1305  *	get ifalias for a device.  Caller must make sure dev cannot go
1306  *	away,  e.g. rcu read lock or own a reference count to device.
1307  */
1308 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1309 {
1310 	const struct dev_ifalias *alias;
1311 	int ret = 0;
1312 
1313 	rcu_read_lock();
1314 	alias = rcu_dereference(dev->ifalias);
1315 	if (alias)
1316 		ret = snprintf(name, len, "%s", alias->ifalias);
1317 	rcu_read_unlock();
1318 
1319 	return ret;
1320 }
1321 
1322 /**
1323  *	netdev_features_change - device changes features
1324  *	@dev: device to cause notification
1325  *
1326  *	Called to indicate a device has changed features.
1327  */
1328 void netdev_features_change(struct net_device *dev)
1329 {
1330 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1331 }
1332 EXPORT_SYMBOL(netdev_features_change);
1333 
1334 /**
1335  *	netdev_state_change - device changes state
1336  *	@dev: device to cause notification
1337  *
1338  *	Called to indicate a device has changed state. This function calls
1339  *	the notifier chains for netdev_chain and sends a NEWLINK message
1340  *	to the routing socket.
1341  */
1342 void netdev_state_change(struct net_device *dev)
1343 {
1344 	if (dev->flags & IFF_UP) {
1345 		struct netdev_notifier_change_info change_info = {
1346 			.info.dev = dev,
1347 		};
1348 
1349 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1350 					      &change_info.info);
1351 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1352 	}
1353 }
1354 EXPORT_SYMBOL(netdev_state_change);
1355 
1356 /**
1357  * __netdev_notify_peers - notify network peers about existence of @dev,
1358  * to be called when rtnl lock is already held.
1359  * @dev: network device
1360  *
1361  * Generate traffic such that interested network peers are aware of
1362  * @dev, such as by generating a gratuitous ARP. This may be used when
1363  * a device wants to inform the rest of the network about some sort of
1364  * reconfiguration such as a failover event or virtual machine
1365  * migration.
1366  */
1367 void __netdev_notify_peers(struct net_device *dev)
1368 {
1369 	ASSERT_RTNL();
1370 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1371 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1372 }
1373 EXPORT_SYMBOL(__netdev_notify_peers);
1374 
1375 /**
1376  * netdev_notify_peers - notify network peers about existence of @dev
1377  * @dev: network device
1378  *
1379  * Generate traffic such that interested network peers are aware of
1380  * @dev, such as by generating a gratuitous ARP. This may be used when
1381  * a device wants to inform the rest of the network about some sort of
1382  * reconfiguration such as a failover event or virtual machine
1383  * migration.
1384  */
1385 void netdev_notify_peers(struct net_device *dev)
1386 {
1387 	rtnl_lock();
1388 	__netdev_notify_peers(dev);
1389 	rtnl_unlock();
1390 }
1391 EXPORT_SYMBOL(netdev_notify_peers);
1392 
1393 static int napi_threaded_poll(void *data);
1394 
1395 static int napi_kthread_create(struct napi_struct *n)
1396 {
1397 	int err = 0;
1398 
1399 	/* Create and wake up the kthread once to put it in
1400 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1401 	 * warning and work with loadavg.
1402 	 */
1403 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1404 				n->dev->name, n->napi_id);
1405 	if (IS_ERR(n->thread)) {
1406 		err = PTR_ERR(n->thread);
1407 		pr_err("kthread_run failed with err %d\n", err);
1408 		n->thread = NULL;
1409 	}
1410 
1411 	return err;
1412 }
1413 
1414 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1415 {
1416 	const struct net_device_ops *ops = dev->netdev_ops;
1417 	int ret;
1418 
1419 	ASSERT_RTNL();
1420 	dev_addr_check(dev);
1421 
1422 	if (!netif_device_present(dev)) {
1423 		/* may be detached because parent is runtime-suspended */
1424 		if (dev->dev.parent)
1425 			pm_runtime_resume(dev->dev.parent);
1426 		if (!netif_device_present(dev))
1427 			return -ENODEV;
1428 	}
1429 
1430 	/* Block netpoll from trying to do any rx path servicing.
1431 	 * If we don't do this there is a chance ndo_poll_controller
1432 	 * or ndo_poll may be running while we open the device
1433 	 */
1434 	netpoll_poll_disable(dev);
1435 
1436 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1437 	ret = notifier_to_errno(ret);
1438 	if (ret)
1439 		return ret;
1440 
1441 	set_bit(__LINK_STATE_START, &dev->state);
1442 
1443 	if (ops->ndo_validate_addr)
1444 		ret = ops->ndo_validate_addr(dev);
1445 
1446 	if (!ret && ops->ndo_open)
1447 		ret = ops->ndo_open(dev);
1448 
1449 	netpoll_poll_enable(dev);
1450 
1451 	if (ret)
1452 		clear_bit(__LINK_STATE_START, &dev->state);
1453 	else {
1454 		dev->flags |= IFF_UP;
1455 		dev_set_rx_mode(dev);
1456 		dev_activate(dev);
1457 		add_device_randomness(dev->dev_addr, dev->addr_len);
1458 	}
1459 
1460 	return ret;
1461 }
1462 
1463 /**
1464  *	dev_open	- prepare an interface for use.
1465  *	@dev: device to open
1466  *	@extack: netlink extended ack
1467  *
1468  *	Takes a device from down to up state. The device's private open
1469  *	function is invoked and then the multicast lists are loaded. Finally
1470  *	the device is moved into the up state and a %NETDEV_UP message is
1471  *	sent to the netdev notifier chain.
1472  *
1473  *	Calling this function on an active interface is a nop. On a failure
1474  *	a negative errno code is returned.
1475  */
1476 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1477 {
1478 	int ret;
1479 
1480 	if (dev->flags & IFF_UP)
1481 		return 0;
1482 
1483 	ret = __dev_open(dev, extack);
1484 	if (ret < 0)
1485 		return ret;
1486 
1487 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1488 	call_netdevice_notifiers(NETDEV_UP, dev);
1489 
1490 	return ret;
1491 }
1492 EXPORT_SYMBOL(dev_open);
1493 
1494 static void __dev_close_many(struct list_head *head)
1495 {
1496 	struct net_device *dev;
1497 
1498 	ASSERT_RTNL();
1499 	might_sleep();
1500 
1501 	list_for_each_entry(dev, head, close_list) {
1502 		/* Temporarily disable netpoll until the interface is down */
1503 		netpoll_poll_disable(dev);
1504 
1505 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1506 
1507 		clear_bit(__LINK_STATE_START, &dev->state);
1508 
1509 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1510 		 * can be even on different cpu. So just clear netif_running().
1511 		 *
1512 		 * dev->stop() will invoke napi_disable() on all of it's
1513 		 * napi_struct instances on this device.
1514 		 */
1515 		smp_mb__after_atomic(); /* Commit netif_running(). */
1516 	}
1517 
1518 	dev_deactivate_many(head);
1519 
1520 	list_for_each_entry(dev, head, close_list) {
1521 		const struct net_device_ops *ops = dev->netdev_ops;
1522 
1523 		/*
1524 		 *	Call the device specific close. This cannot fail.
1525 		 *	Only if device is UP
1526 		 *
1527 		 *	We allow it to be called even after a DETACH hot-plug
1528 		 *	event.
1529 		 */
1530 		if (ops->ndo_stop)
1531 			ops->ndo_stop(dev);
1532 
1533 		dev->flags &= ~IFF_UP;
1534 		netpoll_poll_enable(dev);
1535 	}
1536 }
1537 
1538 static void __dev_close(struct net_device *dev)
1539 {
1540 	LIST_HEAD(single);
1541 
1542 	list_add(&dev->close_list, &single);
1543 	__dev_close_many(&single);
1544 	list_del(&single);
1545 }
1546 
1547 void dev_close_many(struct list_head *head, bool unlink)
1548 {
1549 	struct net_device *dev, *tmp;
1550 
1551 	/* Remove the devices that don't need to be closed */
1552 	list_for_each_entry_safe(dev, tmp, head, close_list)
1553 		if (!(dev->flags & IFF_UP))
1554 			list_del_init(&dev->close_list);
1555 
1556 	__dev_close_many(head);
1557 
1558 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1559 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1560 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1561 		if (unlink)
1562 			list_del_init(&dev->close_list);
1563 	}
1564 }
1565 EXPORT_SYMBOL(dev_close_many);
1566 
1567 /**
1568  *	dev_close - shutdown an interface.
1569  *	@dev: device to shutdown
1570  *
1571  *	This function moves an active device into down state. A
1572  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1573  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1574  *	chain.
1575  */
1576 void dev_close(struct net_device *dev)
1577 {
1578 	if (dev->flags & IFF_UP) {
1579 		LIST_HEAD(single);
1580 
1581 		list_add(&dev->close_list, &single);
1582 		dev_close_many(&single, true);
1583 		list_del(&single);
1584 	}
1585 }
1586 EXPORT_SYMBOL(dev_close);
1587 
1588 
1589 /**
1590  *	dev_disable_lro - disable Large Receive Offload on a device
1591  *	@dev: device
1592  *
1593  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1594  *	called under RTNL.  This is needed if received packets may be
1595  *	forwarded to another interface.
1596  */
1597 void dev_disable_lro(struct net_device *dev)
1598 {
1599 	struct net_device *lower_dev;
1600 	struct list_head *iter;
1601 
1602 	dev->wanted_features &= ~NETIF_F_LRO;
1603 	netdev_update_features(dev);
1604 
1605 	if (unlikely(dev->features & NETIF_F_LRO))
1606 		netdev_WARN(dev, "failed to disable LRO!\n");
1607 
1608 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1609 		dev_disable_lro(lower_dev);
1610 }
1611 EXPORT_SYMBOL(dev_disable_lro);
1612 
1613 /**
1614  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1615  *	@dev: device
1616  *
1617  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1618  *	called under RTNL.  This is needed if Generic XDP is installed on
1619  *	the device.
1620  */
1621 static void dev_disable_gro_hw(struct net_device *dev)
1622 {
1623 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1624 	netdev_update_features(dev);
1625 
1626 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1627 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1628 }
1629 
1630 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1631 {
1632 #define N(val) 						\
1633 	case NETDEV_##val:				\
1634 		return "NETDEV_" __stringify(val);
1635 	switch (cmd) {
1636 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1637 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1638 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1639 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1640 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1641 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1642 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1643 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1644 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1645 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1646 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1647 	N(XDP_FEAT_CHANGE)
1648 	}
1649 #undef N
1650 	return "UNKNOWN_NETDEV_EVENT";
1651 }
1652 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1653 
1654 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1655 				   struct net_device *dev)
1656 {
1657 	struct netdev_notifier_info info = {
1658 		.dev = dev,
1659 	};
1660 
1661 	return nb->notifier_call(nb, val, &info);
1662 }
1663 
1664 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1665 					     struct net_device *dev)
1666 {
1667 	int err;
1668 
1669 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1670 	err = notifier_to_errno(err);
1671 	if (err)
1672 		return err;
1673 
1674 	if (!(dev->flags & IFF_UP))
1675 		return 0;
1676 
1677 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1678 	return 0;
1679 }
1680 
1681 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1682 						struct net_device *dev)
1683 {
1684 	if (dev->flags & IFF_UP) {
1685 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1686 					dev);
1687 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1688 	}
1689 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1690 }
1691 
1692 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1693 						 struct net *net)
1694 {
1695 	struct net_device *dev;
1696 	int err;
1697 
1698 	for_each_netdev(net, dev) {
1699 		err = call_netdevice_register_notifiers(nb, dev);
1700 		if (err)
1701 			goto rollback;
1702 	}
1703 	return 0;
1704 
1705 rollback:
1706 	for_each_netdev_continue_reverse(net, dev)
1707 		call_netdevice_unregister_notifiers(nb, dev);
1708 	return err;
1709 }
1710 
1711 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1712 						    struct net *net)
1713 {
1714 	struct net_device *dev;
1715 
1716 	for_each_netdev(net, dev)
1717 		call_netdevice_unregister_notifiers(nb, dev);
1718 }
1719 
1720 static int dev_boot_phase = 1;
1721 
1722 /**
1723  * register_netdevice_notifier - register a network notifier block
1724  * @nb: notifier
1725  *
1726  * Register a notifier to be called when network device events occur.
1727  * The notifier passed is linked into the kernel structures and must
1728  * not be reused until it has been unregistered. A negative errno code
1729  * is returned on a failure.
1730  *
1731  * When registered all registration and up events are replayed
1732  * to the new notifier to allow device to have a race free
1733  * view of the network device list.
1734  */
1735 
1736 int register_netdevice_notifier(struct notifier_block *nb)
1737 {
1738 	struct net *net;
1739 	int err;
1740 
1741 	/* Close race with setup_net() and cleanup_net() */
1742 	down_write(&pernet_ops_rwsem);
1743 	rtnl_lock();
1744 	err = raw_notifier_chain_register(&netdev_chain, nb);
1745 	if (err)
1746 		goto unlock;
1747 	if (dev_boot_phase)
1748 		goto unlock;
1749 	for_each_net(net) {
1750 		err = call_netdevice_register_net_notifiers(nb, net);
1751 		if (err)
1752 			goto rollback;
1753 	}
1754 
1755 unlock:
1756 	rtnl_unlock();
1757 	up_write(&pernet_ops_rwsem);
1758 	return err;
1759 
1760 rollback:
1761 	for_each_net_continue_reverse(net)
1762 		call_netdevice_unregister_net_notifiers(nb, net);
1763 
1764 	raw_notifier_chain_unregister(&netdev_chain, nb);
1765 	goto unlock;
1766 }
1767 EXPORT_SYMBOL(register_netdevice_notifier);
1768 
1769 /**
1770  * unregister_netdevice_notifier - unregister a network notifier block
1771  * @nb: notifier
1772  *
1773  * Unregister a notifier previously registered by
1774  * register_netdevice_notifier(). The notifier is unlinked into the
1775  * kernel structures and may then be reused. A negative errno code
1776  * is returned on a failure.
1777  *
1778  * After unregistering unregister and down device events are synthesized
1779  * for all devices on the device list to the removed notifier to remove
1780  * the need for special case cleanup code.
1781  */
1782 
1783 int unregister_netdevice_notifier(struct notifier_block *nb)
1784 {
1785 	struct net *net;
1786 	int err;
1787 
1788 	/* Close race with setup_net() and cleanup_net() */
1789 	down_write(&pernet_ops_rwsem);
1790 	rtnl_lock();
1791 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1792 	if (err)
1793 		goto unlock;
1794 
1795 	for_each_net(net)
1796 		call_netdevice_unregister_net_notifiers(nb, net);
1797 
1798 unlock:
1799 	rtnl_unlock();
1800 	up_write(&pernet_ops_rwsem);
1801 	return err;
1802 }
1803 EXPORT_SYMBOL(unregister_netdevice_notifier);
1804 
1805 static int __register_netdevice_notifier_net(struct net *net,
1806 					     struct notifier_block *nb,
1807 					     bool ignore_call_fail)
1808 {
1809 	int err;
1810 
1811 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1812 	if (err)
1813 		return err;
1814 	if (dev_boot_phase)
1815 		return 0;
1816 
1817 	err = call_netdevice_register_net_notifiers(nb, net);
1818 	if (err && !ignore_call_fail)
1819 		goto chain_unregister;
1820 
1821 	return 0;
1822 
1823 chain_unregister:
1824 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1825 	return err;
1826 }
1827 
1828 static int __unregister_netdevice_notifier_net(struct net *net,
1829 					       struct notifier_block *nb)
1830 {
1831 	int err;
1832 
1833 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1834 	if (err)
1835 		return err;
1836 
1837 	call_netdevice_unregister_net_notifiers(nb, net);
1838 	return 0;
1839 }
1840 
1841 /**
1842  * register_netdevice_notifier_net - register a per-netns network notifier block
1843  * @net: network namespace
1844  * @nb: notifier
1845  *
1846  * Register a notifier to be called when network device events occur.
1847  * The notifier passed is linked into the kernel structures and must
1848  * not be reused until it has been unregistered. A negative errno code
1849  * is returned on a failure.
1850  *
1851  * When registered all registration and up events are replayed
1852  * to the new notifier to allow device to have a race free
1853  * view of the network device list.
1854  */
1855 
1856 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1857 {
1858 	int err;
1859 
1860 	rtnl_lock();
1861 	err = __register_netdevice_notifier_net(net, nb, false);
1862 	rtnl_unlock();
1863 	return err;
1864 }
1865 EXPORT_SYMBOL(register_netdevice_notifier_net);
1866 
1867 /**
1868  * unregister_netdevice_notifier_net - unregister a per-netns
1869  *                                     network notifier block
1870  * @net: network namespace
1871  * @nb: notifier
1872  *
1873  * Unregister a notifier previously registered by
1874  * register_netdevice_notifier_net(). The notifier is unlinked from the
1875  * kernel structures and may then be reused. A negative errno code
1876  * is returned on a failure.
1877  *
1878  * After unregistering unregister and down device events are synthesized
1879  * for all devices on the device list to the removed notifier to remove
1880  * the need for special case cleanup code.
1881  */
1882 
1883 int unregister_netdevice_notifier_net(struct net *net,
1884 				      struct notifier_block *nb)
1885 {
1886 	int err;
1887 
1888 	rtnl_lock();
1889 	err = __unregister_netdevice_notifier_net(net, nb);
1890 	rtnl_unlock();
1891 	return err;
1892 }
1893 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1894 
1895 static void __move_netdevice_notifier_net(struct net *src_net,
1896 					  struct net *dst_net,
1897 					  struct notifier_block *nb)
1898 {
1899 	__unregister_netdevice_notifier_net(src_net, nb);
1900 	__register_netdevice_notifier_net(dst_net, nb, true);
1901 }
1902 
1903 int register_netdevice_notifier_dev_net(struct net_device *dev,
1904 					struct notifier_block *nb,
1905 					struct netdev_net_notifier *nn)
1906 {
1907 	int err;
1908 
1909 	rtnl_lock();
1910 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1911 	if (!err) {
1912 		nn->nb = nb;
1913 		list_add(&nn->list, &dev->net_notifier_list);
1914 	}
1915 	rtnl_unlock();
1916 	return err;
1917 }
1918 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1919 
1920 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1921 					  struct notifier_block *nb,
1922 					  struct netdev_net_notifier *nn)
1923 {
1924 	int err;
1925 
1926 	rtnl_lock();
1927 	list_del(&nn->list);
1928 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1929 	rtnl_unlock();
1930 	return err;
1931 }
1932 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1933 
1934 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1935 					     struct net *net)
1936 {
1937 	struct netdev_net_notifier *nn;
1938 
1939 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1940 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1941 }
1942 
1943 /**
1944  *	call_netdevice_notifiers_info - call all network notifier blocks
1945  *	@val: value passed unmodified to notifier function
1946  *	@info: notifier information data
1947  *
1948  *	Call all network notifier blocks.  Parameters and return value
1949  *	are as for raw_notifier_call_chain().
1950  */
1951 
1952 int call_netdevice_notifiers_info(unsigned long val,
1953 				  struct netdev_notifier_info *info)
1954 {
1955 	struct net *net = dev_net(info->dev);
1956 	int ret;
1957 
1958 	ASSERT_RTNL();
1959 
1960 	/* Run per-netns notifier block chain first, then run the global one.
1961 	 * Hopefully, one day, the global one is going to be removed after
1962 	 * all notifier block registrators get converted to be per-netns.
1963 	 */
1964 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1965 	if (ret & NOTIFY_STOP_MASK)
1966 		return ret;
1967 	return raw_notifier_call_chain(&netdev_chain, val, info);
1968 }
1969 
1970 /**
1971  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1972  *	                                       for and rollback on error
1973  *	@val_up: value passed unmodified to notifier function
1974  *	@val_down: value passed unmodified to the notifier function when
1975  *	           recovering from an error on @val_up
1976  *	@info: notifier information data
1977  *
1978  *	Call all per-netns network notifier blocks, but not notifier blocks on
1979  *	the global notifier chain. Parameters and return value are as for
1980  *	raw_notifier_call_chain_robust().
1981  */
1982 
1983 static int
1984 call_netdevice_notifiers_info_robust(unsigned long val_up,
1985 				     unsigned long val_down,
1986 				     struct netdev_notifier_info *info)
1987 {
1988 	struct net *net = dev_net(info->dev);
1989 
1990 	ASSERT_RTNL();
1991 
1992 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1993 					      val_up, val_down, info);
1994 }
1995 
1996 static int call_netdevice_notifiers_extack(unsigned long val,
1997 					   struct net_device *dev,
1998 					   struct netlink_ext_ack *extack)
1999 {
2000 	struct netdev_notifier_info info = {
2001 		.dev = dev,
2002 		.extack = extack,
2003 	};
2004 
2005 	return call_netdevice_notifiers_info(val, &info);
2006 }
2007 
2008 /**
2009  *	call_netdevice_notifiers - call all network notifier blocks
2010  *      @val: value passed unmodified to notifier function
2011  *      @dev: net_device pointer passed unmodified to notifier function
2012  *
2013  *	Call all network notifier blocks.  Parameters and return value
2014  *	are as for raw_notifier_call_chain().
2015  */
2016 
2017 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
2018 {
2019 	return call_netdevice_notifiers_extack(val, dev, NULL);
2020 }
2021 EXPORT_SYMBOL(call_netdevice_notifiers);
2022 
2023 /**
2024  *	call_netdevice_notifiers_mtu - call all network notifier blocks
2025  *	@val: value passed unmodified to notifier function
2026  *	@dev: net_device pointer passed unmodified to notifier function
2027  *	@arg: additional u32 argument passed to the notifier function
2028  *
2029  *	Call all network notifier blocks.  Parameters and return value
2030  *	are as for raw_notifier_call_chain().
2031  */
2032 static int call_netdevice_notifiers_mtu(unsigned long val,
2033 					struct net_device *dev, u32 arg)
2034 {
2035 	struct netdev_notifier_info_ext info = {
2036 		.info.dev = dev,
2037 		.ext.mtu = arg,
2038 	};
2039 
2040 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2041 
2042 	return call_netdevice_notifiers_info(val, &info.info);
2043 }
2044 
2045 #ifdef CONFIG_NET_INGRESS
2046 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2047 
2048 void net_inc_ingress_queue(void)
2049 {
2050 	static_branch_inc(&ingress_needed_key);
2051 }
2052 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2053 
2054 void net_dec_ingress_queue(void)
2055 {
2056 	static_branch_dec(&ingress_needed_key);
2057 }
2058 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2059 #endif
2060 
2061 #ifdef CONFIG_NET_EGRESS
2062 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2063 
2064 void net_inc_egress_queue(void)
2065 {
2066 	static_branch_inc(&egress_needed_key);
2067 }
2068 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2069 
2070 void net_dec_egress_queue(void)
2071 {
2072 	static_branch_dec(&egress_needed_key);
2073 }
2074 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2075 #endif
2076 
2077 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2078 EXPORT_SYMBOL(netstamp_needed_key);
2079 #ifdef CONFIG_JUMP_LABEL
2080 static atomic_t netstamp_needed_deferred;
2081 static atomic_t netstamp_wanted;
2082 static void netstamp_clear(struct work_struct *work)
2083 {
2084 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2085 	int wanted;
2086 
2087 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2088 	if (wanted > 0)
2089 		static_branch_enable(&netstamp_needed_key);
2090 	else
2091 		static_branch_disable(&netstamp_needed_key);
2092 }
2093 static DECLARE_WORK(netstamp_work, netstamp_clear);
2094 #endif
2095 
2096 void net_enable_timestamp(void)
2097 {
2098 #ifdef CONFIG_JUMP_LABEL
2099 	int wanted = atomic_read(&netstamp_wanted);
2100 
2101 	while (wanted > 0) {
2102 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2103 			return;
2104 	}
2105 	atomic_inc(&netstamp_needed_deferred);
2106 	schedule_work(&netstamp_work);
2107 #else
2108 	static_branch_inc(&netstamp_needed_key);
2109 #endif
2110 }
2111 EXPORT_SYMBOL(net_enable_timestamp);
2112 
2113 void net_disable_timestamp(void)
2114 {
2115 #ifdef CONFIG_JUMP_LABEL
2116 	int wanted = atomic_read(&netstamp_wanted);
2117 
2118 	while (wanted > 1) {
2119 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2120 			return;
2121 	}
2122 	atomic_dec(&netstamp_needed_deferred);
2123 	schedule_work(&netstamp_work);
2124 #else
2125 	static_branch_dec(&netstamp_needed_key);
2126 #endif
2127 }
2128 EXPORT_SYMBOL(net_disable_timestamp);
2129 
2130 static inline void net_timestamp_set(struct sk_buff *skb)
2131 {
2132 	skb->tstamp = 0;
2133 	skb->mono_delivery_time = 0;
2134 	if (static_branch_unlikely(&netstamp_needed_key))
2135 		skb->tstamp = ktime_get_real();
2136 }
2137 
2138 #define net_timestamp_check(COND, SKB)				\
2139 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2140 		if ((COND) && !(SKB)->tstamp)			\
2141 			(SKB)->tstamp = ktime_get_real();	\
2142 	}							\
2143 
2144 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2145 {
2146 	return __is_skb_forwardable(dev, skb, true);
2147 }
2148 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2149 
2150 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2151 			      bool check_mtu)
2152 {
2153 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2154 
2155 	if (likely(!ret)) {
2156 		skb->protocol = eth_type_trans(skb, dev);
2157 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2158 	}
2159 
2160 	return ret;
2161 }
2162 
2163 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2164 {
2165 	return __dev_forward_skb2(dev, skb, true);
2166 }
2167 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2168 
2169 /**
2170  * dev_forward_skb - loopback an skb to another netif
2171  *
2172  * @dev: destination network device
2173  * @skb: buffer to forward
2174  *
2175  * return values:
2176  *	NET_RX_SUCCESS	(no congestion)
2177  *	NET_RX_DROP     (packet was dropped, but freed)
2178  *
2179  * dev_forward_skb can be used for injecting an skb from the
2180  * start_xmit function of one device into the receive queue
2181  * of another device.
2182  *
2183  * The receiving device may be in another namespace, so
2184  * we have to clear all information in the skb that could
2185  * impact namespace isolation.
2186  */
2187 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2188 {
2189 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2190 }
2191 EXPORT_SYMBOL_GPL(dev_forward_skb);
2192 
2193 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2194 {
2195 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2196 }
2197 
2198 static inline int deliver_skb(struct sk_buff *skb,
2199 			      struct packet_type *pt_prev,
2200 			      struct net_device *orig_dev)
2201 {
2202 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2203 		return -ENOMEM;
2204 	refcount_inc(&skb->users);
2205 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2206 }
2207 
2208 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2209 					  struct packet_type **pt,
2210 					  struct net_device *orig_dev,
2211 					  __be16 type,
2212 					  struct list_head *ptype_list)
2213 {
2214 	struct packet_type *ptype, *pt_prev = *pt;
2215 
2216 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2217 		if (ptype->type != type)
2218 			continue;
2219 		if (pt_prev)
2220 			deliver_skb(skb, pt_prev, orig_dev);
2221 		pt_prev = ptype;
2222 	}
2223 	*pt = pt_prev;
2224 }
2225 
2226 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2227 {
2228 	if (!ptype->af_packet_priv || !skb->sk)
2229 		return false;
2230 
2231 	if (ptype->id_match)
2232 		return ptype->id_match(ptype, skb->sk);
2233 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2234 		return true;
2235 
2236 	return false;
2237 }
2238 
2239 /**
2240  * dev_nit_active - return true if any network interface taps are in use
2241  *
2242  * @dev: network device to check for the presence of taps
2243  */
2244 bool dev_nit_active(struct net_device *dev)
2245 {
2246 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2247 }
2248 EXPORT_SYMBOL_GPL(dev_nit_active);
2249 
2250 /*
2251  *	Support routine. Sends outgoing frames to any network
2252  *	taps currently in use.
2253  */
2254 
2255 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2256 {
2257 	struct packet_type *ptype;
2258 	struct sk_buff *skb2 = NULL;
2259 	struct packet_type *pt_prev = NULL;
2260 	struct list_head *ptype_list = &ptype_all;
2261 
2262 	rcu_read_lock();
2263 again:
2264 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2265 		if (ptype->ignore_outgoing)
2266 			continue;
2267 
2268 		/* Never send packets back to the socket
2269 		 * they originated from - MvS (miquels@drinkel.ow.org)
2270 		 */
2271 		if (skb_loop_sk(ptype, skb))
2272 			continue;
2273 
2274 		if (pt_prev) {
2275 			deliver_skb(skb2, pt_prev, skb->dev);
2276 			pt_prev = ptype;
2277 			continue;
2278 		}
2279 
2280 		/* need to clone skb, done only once */
2281 		skb2 = skb_clone(skb, GFP_ATOMIC);
2282 		if (!skb2)
2283 			goto out_unlock;
2284 
2285 		net_timestamp_set(skb2);
2286 
2287 		/* skb->nh should be correctly
2288 		 * set by sender, so that the second statement is
2289 		 * just protection against buggy protocols.
2290 		 */
2291 		skb_reset_mac_header(skb2);
2292 
2293 		if (skb_network_header(skb2) < skb2->data ||
2294 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2295 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2296 					     ntohs(skb2->protocol),
2297 					     dev->name);
2298 			skb_reset_network_header(skb2);
2299 		}
2300 
2301 		skb2->transport_header = skb2->network_header;
2302 		skb2->pkt_type = PACKET_OUTGOING;
2303 		pt_prev = ptype;
2304 	}
2305 
2306 	if (ptype_list == &ptype_all) {
2307 		ptype_list = &dev->ptype_all;
2308 		goto again;
2309 	}
2310 out_unlock:
2311 	if (pt_prev) {
2312 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2313 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2314 		else
2315 			kfree_skb(skb2);
2316 	}
2317 	rcu_read_unlock();
2318 }
2319 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2320 
2321 /**
2322  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2323  * @dev: Network device
2324  * @txq: number of queues available
2325  *
2326  * If real_num_tx_queues is changed the tc mappings may no longer be
2327  * valid. To resolve this verify the tc mapping remains valid and if
2328  * not NULL the mapping. With no priorities mapping to this
2329  * offset/count pair it will no longer be used. In the worst case TC0
2330  * is invalid nothing can be done so disable priority mappings. If is
2331  * expected that drivers will fix this mapping if they can before
2332  * calling netif_set_real_num_tx_queues.
2333  */
2334 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2335 {
2336 	int i;
2337 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2338 
2339 	/* If TC0 is invalidated disable TC mapping */
2340 	if (tc->offset + tc->count > txq) {
2341 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2342 		dev->num_tc = 0;
2343 		return;
2344 	}
2345 
2346 	/* Invalidated prio to tc mappings set to TC0 */
2347 	for (i = 1; i < TC_BITMASK + 1; i++) {
2348 		int q = netdev_get_prio_tc_map(dev, i);
2349 
2350 		tc = &dev->tc_to_txq[q];
2351 		if (tc->offset + tc->count > txq) {
2352 			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",
2353 				    i, q);
2354 			netdev_set_prio_tc_map(dev, i, 0);
2355 		}
2356 	}
2357 }
2358 
2359 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2360 {
2361 	if (dev->num_tc) {
2362 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2363 		int i;
2364 
2365 		/* walk through the TCs and see if it falls into any of them */
2366 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2367 			if ((txq - tc->offset) < tc->count)
2368 				return i;
2369 		}
2370 
2371 		/* didn't find it, just return -1 to indicate no match */
2372 		return -1;
2373 	}
2374 
2375 	return 0;
2376 }
2377 EXPORT_SYMBOL(netdev_txq_to_tc);
2378 
2379 #ifdef CONFIG_XPS
2380 static struct static_key xps_needed __read_mostly;
2381 static struct static_key xps_rxqs_needed __read_mostly;
2382 static DEFINE_MUTEX(xps_map_mutex);
2383 #define xmap_dereference(P)		\
2384 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2385 
2386 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2387 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2388 {
2389 	struct xps_map *map = NULL;
2390 	int pos;
2391 
2392 	map = xmap_dereference(dev_maps->attr_map[tci]);
2393 	if (!map)
2394 		return false;
2395 
2396 	for (pos = map->len; pos--;) {
2397 		if (map->queues[pos] != index)
2398 			continue;
2399 
2400 		if (map->len > 1) {
2401 			map->queues[pos] = map->queues[--map->len];
2402 			break;
2403 		}
2404 
2405 		if (old_maps)
2406 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2407 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2408 		kfree_rcu(map, rcu);
2409 		return false;
2410 	}
2411 
2412 	return true;
2413 }
2414 
2415 static bool remove_xps_queue_cpu(struct net_device *dev,
2416 				 struct xps_dev_maps *dev_maps,
2417 				 int cpu, u16 offset, u16 count)
2418 {
2419 	int num_tc = dev_maps->num_tc;
2420 	bool active = false;
2421 	int tci;
2422 
2423 	for (tci = cpu * num_tc; num_tc--; tci++) {
2424 		int i, j;
2425 
2426 		for (i = count, j = offset; i--; j++) {
2427 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2428 				break;
2429 		}
2430 
2431 		active |= i < 0;
2432 	}
2433 
2434 	return active;
2435 }
2436 
2437 static void reset_xps_maps(struct net_device *dev,
2438 			   struct xps_dev_maps *dev_maps,
2439 			   enum xps_map_type type)
2440 {
2441 	static_key_slow_dec_cpuslocked(&xps_needed);
2442 	if (type == XPS_RXQS)
2443 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2444 
2445 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2446 
2447 	kfree_rcu(dev_maps, rcu);
2448 }
2449 
2450 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2451 			   u16 offset, u16 count)
2452 {
2453 	struct xps_dev_maps *dev_maps;
2454 	bool active = false;
2455 	int i, j;
2456 
2457 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2458 	if (!dev_maps)
2459 		return;
2460 
2461 	for (j = 0; j < dev_maps->nr_ids; j++)
2462 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2463 	if (!active)
2464 		reset_xps_maps(dev, dev_maps, type);
2465 
2466 	if (type == XPS_CPUS) {
2467 		for (i = offset + (count - 1); count--; i--)
2468 			netdev_queue_numa_node_write(
2469 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2470 	}
2471 }
2472 
2473 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2474 				   u16 count)
2475 {
2476 	if (!static_key_false(&xps_needed))
2477 		return;
2478 
2479 	cpus_read_lock();
2480 	mutex_lock(&xps_map_mutex);
2481 
2482 	if (static_key_false(&xps_rxqs_needed))
2483 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2484 
2485 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2486 
2487 	mutex_unlock(&xps_map_mutex);
2488 	cpus_read_unlock();
2489 }
2490 
2491 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2492 {
2493 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2494 }
2495 
2496 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2497 				      u16 index, bool is_rxqs_map)
2498 {
2499 	struct xps_map *new_map;
2500 	int alloc_len = XPS_MIN_MAP_ALLOC;
2501 	int i, pos;
2502 
2503 	for (pos = 0; map && pos < map->len; pos++) {
2504 		if (map->queues[pos] != index)
2505 			continue;
2506 		return map;
2507 	}
2508 
2509 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2510 	if (map) {
2511 		if (pos < map->alloc_len)
2512 			return map;
2513 
2514 		alloc_len = map->alloc_len * 2;
2515 	}
2516 
2517 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2518 	 *  map
2519 	 */
2520 	if (is_rxqs_map)
2521 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2522 	else
2523 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2524 				       cpu_to_node(attr_index));
2525 	if (!new_map)
2526 		return NULL;
2527 
2528 	for (i = 0; i < pos; i++)
2529 		new_map->queues[i] = map->queues[i];
2530 	new_map->alloc_len = alloc_len;
2531 	new_map->len = pos;
2532 
2533 	return new_map;
2534 }
2535 
2536 /* Copy xps maps at a given index */
2537 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2538 			      struct xps_dev_maps *new_dev_maps, int index,
2539 			      int tc, bool skip_tc)
2540 {
2541 	int i, tci = index * dev_maps->num_tc;
2542 	struct xps_map *map;
2543 
2544 	/* copy maps belonging to foreign traffic classes */
2545 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2546 		if (i == tc && skip_tc)
2547 			continue;
2548 
2549 		/* fill in the new device map from the old device map */
2550 		map = xmap_dereference(dev_maps->attr_map[tci]);
2551 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2552 	}
2553 }
2554 
2555 /* Must be called under cpus_read_lock */
2556 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2557 			  u16 index, enum xps_map_type type)
2558 {
2559 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2560 	const unsigned long *online_mask = NULL;
2561 	bool active = false, copy = false;
2562 	int i, j, tci, numa_node_id = -2;
2563 	int maps_sz, num_tc = 1, tc = 0;
2564 	struct xps_map *map, *new_map;
2565 	unsigned int nr_ids;
2566 
2567 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2568 
2569 	if (dev->num_tc) {
2570 		/* Do not allow XPS on subordinate device directly */
2571 		num_tc = dev->num_tc;
2572 		if (num_tc < 0)
2573 			return -EINVAL;
2574 
2575 		/* If queue belongs to subordinate dev use its map */
2576 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2577 
2578 		tc = netdev_txq_to_tc(dev, index);
2579 		if (tc < 0)
2580 			return -EINVAL;
2581 	}
2582 
2583 	mutex_lock(&xps_map_mutex);
2584 
2585 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2586 	if (type == XPS_RXQS) {
2587 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2588 		nr_ids = dev->num_rx_queues;
2589 	} else {
2590 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2591 		if (num_possible_cpus() > 1)
2592 			online_mask = cpumask_bits(cpu_online_mask);
2593 		nr_ids = nr_cpu_ids;
2594 	}
2595 
2596 	if (maps_sz < L1_CACHE_BYTES)
2597 		maps_sz = L1_CACHE_BYTES;
2598 
2599 	/* The old dev_maps could be larger or smaller than the one we're
2600 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2601 	 * between. We could try to be smart, but let's be safe instead and only
2602 	 * copy foreign traffic classes if the two map sizes match.
2603 	 */
2604 	if (dev_maps &&
2605 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2606 		copy = true;
2607 
2608 	/* allocate memory for queue storage */
2609 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2610 	     j < nr_ids;) {
2611 		if (!new_dev_maps) {
2612 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2613 			if (!new_dev_maps) {
2614 				mutex_unlock(&xps_map_mutex);
2615 				return -ENOMEM;
2616 			}
2617 
2618 			new_dev_maps->nr_ids = nr_ids;
2619 			new_dev_maps->num_tc = num_tc;
2620 		}
2621 
2622 		tci = j * num_tc + tc;
2623 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2624 
2625 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2626 		if (!map)
2627 			goto error;
2628 
2629 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2630 	}
2631 
2632 	if (!new_dev_maps)
2633 		goto out_no_new_maps;
2634 
2635 	if (!dev_maps) {
2636 		/* Increment static keys at most once per type */
2637 		static_key_slow_inc_cpuslocked(&xps_needed);
2638 		if (type == XPS_RXQS)
2639 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2640 	}
2641 
2642 	for (j = 0; j < nr_ids; j++) {
2643 		bool skip_tc = false;
2644 
2645 		tci = j * num_tc + tc;
2646 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2647 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2648 			/* add tx-queue to CPU/rx-queue maps */
2649 			int pos = 0;
2650 
2651 			skip_tc = true;
2652 
2653 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2654 			while ((pos < map->len) && (map->queues[pos] != index))
2655 				pos++;
2656 
2657 			if (pos == map->len)
2658 				map->queues[map->len++] = index;
2659 #ifdef CONFIG_NUMA
2660 			if (type == XPS_CPUS) {
2661 				if (numa_node_id == -2)
2662 					numa_node_id = cpu_to_node(j);
2663 				else if (numa_node_id != cpu_to_node(j))
2664 					numa_node_id = -1;
2665 			}
2666 #endif
2667 		}
2668 
2669 		if (copy)
2670 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2671 					  skip_tc);
2672 	}
2673 
2674 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2675 
2676 	/* Cleanup old maps */
2677 	if (!dev_maps)
2678 		goto out_no_old_maps;
2679 
2680 	for (j = 0; j < dev_maps->nr_ids; j++) {
2681 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2682 			map = xmap_dereference(dev_maps->attr_map[tci]);
2683 			if (!map)
2684 				continue;
2685 
2686 			if (copy) {
2687 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2688 				if (map == new_map)
2689 					continue;
2690 			}
2691 
2692 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2693 			kfree_rcu(map, rcu);
2694 		}
2695 	}
2696 
2697 	old_dev_maps = dev_maps;
2698 
2699 out_no_old_maps:
2700 	dev_maps = new_dev_maps;
2701 	active = true;
2702 
2703 out_no_new_maps:
2704 	if (type == XPS_CPUS)
2705 		/* update Tx queue numa node */
2706 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2707 					     (numa_node_id >= 0) ?
2708 					     numa_node_id : NUMA_NO_NODE);
2709 
2710 	if (!dev_maps)
2711 		goto out_no_maps;
2712 
2713 	/* removes tx-queue from unused CPUs/rx-queues */
2714 	for (j = 0; j < dev_maps->nr_ids; j++) {
2715 		tci = j * dev_maps->num_tc;
2716 
2717 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2718 			if (i == tc &&
2719 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2720 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2721 				continue;
2722 
2723 			active |= remove_xps_queue(dev_maps,
2724 						   copy ? old_dev_maps : NULL,
2725 						   tci, index);
2726 		}
2727 	}
2728 
2729 	if (old_dev_maps)
2730 		kfree_rcu(old_dev_maps, rcu);
2731 
2732 	/* free map if not active */
2733 	if (!active)
2734 		reset_xps_maps(dev, dev_maps, type);
2735 
2736 out_no_maps:
2737 	mutex_unlock(&xps_map_mutex);
2738 
2739 	return 0;
2740 error:
2741 	/* remove any maps that we added */
2742 	for (j = 0; j < nr_ids; j++) {
2743 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2744 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2745 			map = copy ?
2746 			      xmap_dereference(dev_maps->attr_map[tci]) :
2747 			      NULL;
2748 			if (new_map && new_map != map)
2749 				kfree(new_map);
2750 		}
2751 	}
2752 
2753 	mutex_unlock(&xps_map_mutex);
2754 
2755 	kfree(new_dev_maps);
2756 	return -ENOMEM;
2757 }
2758 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2759 
2760 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2761 			u16 index)
2762 {
2763 	int ret;
2764 
2765 	cpus_read_lock();
2766 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2767 	cpus_read_unlock();
2768 
2769 	return ret;
2770 }
2771 EXPORT_SYMBOL(netif_set_xps_queue);
2772 
2773 #endif
2774 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2775 {
2776 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2777 
2778 	/* Unbind any subordinate channels */
2779 	while (txq-- != &dev->_tx[0]) {
2780 		if (txq->sb_dev)
2781 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2782 	}
2783 }
2784 
2785 void netdev_reset_tc(struct net_device *dev)
2786 {
2787 #ifdef CONFIG_XPS
2788 	netif_reset_xps_queues_gt(dev, 0);
2789 #endif
2790 	netdev_unbind_all_sb_channels(dev);
2791 
2792 	/* Reset TC configuration of device */
2793 	dev->num_tc = 0;
2794 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2795 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2796 }
2797 EXPORT_SYMBOL(netdev_reset_tc);
2798 
2799 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2800 {
2801 	if (tc >= dev->num_tc)
2802 		return -EINVAL;
2803 
2804 #ifdef CONFIG_XPS
2805 	netif_reset_xps_queues(dev, offset, count);
2806 #endif
2807 	dev->tc_to_txq[tc].count = count;
2808 	dev->tc_to_txq[tc].offset = offset;
2809 	return 0;
2810 }
2811 EXPORT_SYMBOL(netdev_set_tc_queue);
2812 
2813 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2814 {
2815 	if (num_tc > TC_MAX_QUEUE)
2816 		return -EINVAL;
2817 
2818 #ifdef CONFIG_XPS
2819 	netif_reset_xps_queues_gt(dev, 0);
2820 #endif
2821 	netdev_unbind_all_sb_channels(dev);
2822 
2823 	dev->num_tc = num_tc;
2824 	return 0;
2825 }
2826 EXPORT_SYMBOL(netdev_set_num_tc);
2827 
2828 void netdev_unbind_sb_channel(struct net_device *dev,
2829 			      struct net_device *sb_dev)
2830 {
2831 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2832 
2833 #ifdef CONFIG_XPS
2834 	netif_reset_xps_queues_gt(sb_dev, 0);
2835 #endif
2836 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2837 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2838 
2839 	while (txq-- != &dev->_tx[0]) {
2840 		if (txq->sb_dev == sb_dev)
2841 			txq->sb_dev = NULL;
2842 	}
2843 }
2844 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2845 
2846 int netdev_bind_sb_channel_queue(struct net_device *dev,
2847 				 struct net_device *sb_dev,
2848 				 u8 tc, u16 count, u16 offset)
2849 {
2850 	/* Make certain the sb_dev and dev are already configured */
2851 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2852 		return -EINVAL;
2853 
2854 	/* We cannot hand out queues we don't have */
2855 	if ((offset + count) > dev->real_num_tx_queues)
2856 		return -EINVAL;
2857 
2858 	/* Record the mapping */
2859 	sb_dev->tc_to_txq[tc].count = count;
2860 	sb_dev->tc_to_txq[tc].offset = offset;
2861 
2862 	/* Provide a way for Tx queue to find the tc_to_txq map or
2863 	 * XPS map for itself.
2864 	 */
2865 	while (count--)
2866 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2867 
2868 	return 0;
2869 }
2870 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2871 
2872 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2873 {
2874 	/* Do not use a multiqueue device to represent a subordinate channel */
2875 	if (netif_is_multiqueue(dev))
2876 		return -ENODEV;
2877 
2878 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2879 	 * Channel 0 is meant to be "native" mode and used only to represent
2880 	 * the main root device. We allow writing 0 to reset the device back
2881 	 * to normal mode after being used as a subordinate channel.
2882 	 */
2883 	if (channel > S16_MAX)
2884 		return -EINVAL;
2885 
2886 	dev->num_tc = -channel;
2887 
2888 	return 0;
2889 }
2890 EXPORT_SYMBOL(netdev_set_sb_channel);
2891 
2892 /*
2893  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2894  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2895  */
2896 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2897 {
2898 	bool disabling;
2899 	int rc;
2900 
2901 	disabling = txq < dev->real_num_tx_queues;
2902 
2903 	if (txq < 1 || txq > dev->num_tx_queues)
2904 		return -EINVAL;
2905 
2906 	if (dev->reg_state == NETREG_REGISTERED ||
2907 	    dev->reg_state == NETREG_UNREGISTERING) {
2908 		ASSERT_RTNL();
2909 
2910 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2911 						  txq);
2912 		if (rc)
2913 			return rc;
2914 
2915 		if (dev->num_tc)
2916 			netif_setup_tc(dev, txq);
2917 
2918 		dev_qdisc_change_real_num_tx(dev, txq);
2919 
2920 		dev->real_num_tx_queues = txq;
2921 
2922 		if (disabling) {
2923 			synchronize_net();
2924 			qdisc_reset_all_tx_gt(dev, txq);
2925 #ifdef CONFIG_XPS
2926 			netif_reset_xps_queues_gt(dev, txq);
2927 #endif
2928 		}
2929 	} else {
2930 		dev->real_num_tx_queues = txq;
2931 	}
2932 
2933 	return 0;
2934 }
2935 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2936 
2937 #ifdef CONFIG_SYSFS
2938 /**
2939  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2940  *	@dev: Network device
2941  *	@rxq: Actual number of RX queues
2942  *
2943  *	This must be called either with the rtnl_lock held or before
2944  *	registration of the net device.  Returns 0 on success, or a
2945  *	negative error code.  If called before registration, it always
2946  *	succeeds.
2947  */
2948 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2949 {
2950 	int rc;
2951 
2952 	if (rxq < 1 || rxq > dev->num_rx_queues)
2953 		return -EINVAL;
2954 
2955 	if (dev->reg_state == NETREG_REGISTERED) {
2956 		ASSERT_RTNL();
2957 
2958 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2959 						  rxq);
2960 		if (rc)
2961 			return rc;
2962 	}
2963 
2964 	dev->real_num_rx_queues = rxq;
2965 	return 0;
2966 }
2967 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2968 #endif
2969 
2970 /**
2971  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2972  *	@dev: Network device
2973  *	@txq: Actual number of TX queues
2974  *	@rxq: Actual number of RX queues
2975  *
2976  *	Set the real number of both TX and RX queues.
2977  *	Does nothing if the number of queues is already correct.
2978  */
2979 int netif_set_real_num_queues(struct net_device *dev,
2980 			      unsigned int txq, unsigned int rxq)
2981 {
2982 	unsigned int old_rxq = dev->real_num_rx_queues;
2983 	int err;
2984 
2985 	if (txq < 1 || txq > dev->num_tx_queues ||
2986 	    rxq < 1 || rxq > dev->num_rx_queues)
2987 		return -EINVAL;
2988 
2989 	/* Start from increases, so the error path only does decreases -
2990 	 * decreases can't fail.
2991 	 */
2992 	if (rxq > dev->real_num_rx_queues) {
2993 		err = netif_set_real_num_rx_queues(dev, rxq);
2994 		if (err)
2995 			return err;
2996 	}
2997 	if (txq > dev->real_num_tx_queues) {
2998 		err = netif_set_real_num_tx_queues(dev, txq);
2999 		if (err)
3000 			goto undo_rx;
3001 	}
3002 	if (rxq < dev->real_num_rx_queues)
3003 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
3004 	if (txq < dev->real_num_tx_queues)
3005 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
3006 
3007 	return 0;
3008 undo_rx:
3009 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
3010 	return err;
3011 }
3012 EXPORT_SYMBOL(netif_set_real_num_queues);
3013 
3014 /**
3015  * netif_set_tso_max_size() - set the max size of TSO frames supported
3016  * @dev:	netdev to update
3017  * @size:	max skb->len of a TSO frame
3018  *
3019  * Set the limit on the size of TSO super-frames the device can handle.
3020  * Unless explicitly set the stack will assume the value of
3021  * %GSO_LEGACY_MAX_SIZE.
3022  */
3023 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3024 {
3025 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
3026 	if (size < READ_ONCE(dev->gso_max_size))
3027 		netif_set_gso_max_size(dev, size);
3028 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
3029 		netif_set_gso_ipv4_max_size(dev, size);
3030 }
3031 EXPORT_SYMBOL(netif_set_tso_max_size);
3032 
3033 /**
3034  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3035  * @dev:	netdev to update
3036  * @segs:	max number of TCP segments
3037  *
3038  * Set the limit on the number of TCP segments the device can generate from
3039  * a single TSO super-frame.
3040  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3041  */
3042 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3043 {
3044 	dev->tso_max_segs = segs;
3045 	if (segs < READ_ONCE(dev->gso_max_segs))
3046 		netif_set_gso_max_segs(dev, segs);
3047 }
3048 EXPORT_SYMBOL(netif_set_tso_max_segs);
3049 
3050 /**
3051  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3052  * @to:		netdev to update
3053  * @from:	netdev from which to copy the limits
3054  */
3055 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3056 {
3057 	netif_set_tso_max_size(to, from->tso_max_size);
3058 	netif_set_tso_max_segs(to, from->tso_max_segs);
3059 }
3060 EXPORT_SYMBOL(netif_inherit_tso_max);
3061 
3062 /**
3063  * netif_get_num_default_rss_queues - default number of RSS queues
3064  *
3065  * Default value is the number of physical cores if there are only 1 or 2, or
3066  * divided by 2 if there are more.
3067  */
3068 int netif_get_num_default_rss_queues(void)
3069 {
3070 	cpumask_var_t cpus;
3071 	int cpu, count = 0;
3072 
3073 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3074 		return 1;
3075 
3076 	cpumask_copy(cpus, cpu_online_mask);
3077 	for_each_cpu(cpu, cpus) {
3078 		++count;
3079 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3080 	}
3081 	free_cpumask_var(cpus);
3082 
3083 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3084 }
3085 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3086 
3087 static void __netif_reschedule(struct Qdisc *q)
3088 {
3089 	struct softnet_data *sd;
3090 	unsigned long flags;
3091 
3092 	local_irq_save(flags);
3093 	sd = this_cpu_ptr(&softnet_data);
3094 	q->next_sched = NULL;
3095 	*sd->output_queue_tailp = q;
3096 	sd->output_queue_tailp = &q->next_sched;
3097 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3098 	local_irq_restore(flags);
3099 }
3100 
3101 void __netif_schedule(struct Qdisc *q)
3102 {
3103 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3104 		__netif_reschedule(q);
3105 }
3106 EXPORT_SYMBOL(__netif_schedule);
3107 
3108 struct dev_kfree_skb_cb {
3109 	enum skb_drop_reason reason;
3110 };
3111 
3112 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3113 {
3114 	return (struct dev_kfree_skb_cb *)skb->cb;
3115 }
3116 
3117 void netif_schedule_queue(struct netdev_queue *txq)
3118 {
3119 	rcu_read_lock();
3120 	if (!netif_xmit_stopped(txq)) {
3121 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3122 
3123 		__netif_schedule(q);
3124 	}
3125 	rcu_read_unlock();
3126 }
3127 EXPORT_SYMBOL(netif_schedule_queue);
3128 
3129 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3130 {
3131 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3132 		struct Qdisc *q;
3133 
3134 		rcu_read_lock();
3135 		q = rcu_dereference(dev_queue->qdisc);
3136 		__netif_schedule(q);
3137 		rcu_read_unlock();
3138 	}
3139 }
3140 EXPORT_SYMBOL(netif_tx_wake_queue);
3141 
3142 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3143 {
3144 	unsigned long flags;
3145 
3146 	if (unlikely(!skb))
3147 		return;
3148 
3149 	if (likely(refcount_read(&skb->users) == 1)) {
3150 		smp_rmb();
3151 		refcount_set(&skb->users, 0);
3152 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3153 		return;
3154 	}
3155 	get_kfree_skb_cb(skb)->reason = reason;
3156 	local_irq_save(flags);
3157 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3158 	__this_cpu_write(softnet_data.completion_queue, skb);
3159 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3160 	local_irq_restore(flags);
3161 }
3162 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3163 
3164 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3165 {
3166 	if (in_hardirq() || irqs_disabled())
3167 		dev_kfree_skb_irq_reason(skb, reason);
3168 	else
3169 		kfree_skb_reason(skb, reason);
3170 }
3171 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3172 
3173 
3174 /**
3175  * netif_device_detach - mark device as removed
3176  * @dev: network device
3177  *
3178  * Mark device as removed from system and therefore no longer available.
3179  */
3180 void netif_device_detach(struct net_device *dev)
3181 {
3182 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3183 	    netif_running(dev)) {
3184 		netif_tx_stop_all_queues(dev);
3185 	}
3186 }
3187 EXPORT_SYMBOL(netif_device_detach);
3188 
3189 /**
3190  * netif_device_attach - mark device as attached
3191  * @dev: network device
3192  *
3193  * Mark device as attached from system and restart if needed.
3194  */
3195 void netif_device_attach(struct net_device *dev)
3196 {
3197 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3198 	    netif_running(dev)) {
3199 		netif_tx_wake_all_queues(dev);
3200 		__netdev_watchdog_up(dev);
3201 	}
3202 }
3203 EXPORT_SYMBOL(netif_device_attach);
3204 
3205 /*
3206  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3207  * to be used as a distribution range.
3208  */
3209 static u16 skb_tx_hash(const struct net_device *dev,
3210 		       const struct net_device *sb_dev,
3211 		       struct sk_buff *skb)
3212 {
3213 	u32 hash;
3214 	u16 qoffset = 0;
3215 	u16 qcount = dev->real_num_tx_queues;
3216 
3217 	if (dev->num_tc) {
3218 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3219 
3220 		qoffset = sb_dev->tc_to_txq[tc].offset;
3221 		qcount = sb_dev->tc_to_txq[tc].count;
3222 		if (unlikely(!qcount)) {
3223 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3224 					     sb_dev->name, qoffset, tc);
3225 			qoffset = 0;
3226 			qcount = dev->real_num_tx_queues;
3227 		}
3228 	}
3229 
3230 	if (skb_rx_queue_recorded(skb)) {
3231 		DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3232 		hash = skb_get_rx_queue(skb);
3233 		if (hash >= qoffset)
3234 			hash -= qoffset;
3235 		while (unlikely(hash >= qcount))
3236 			hash -= qcount;
3237 		return hash + qoffset;
3238 	}
3239 
3240 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3241 }
3242 
3243 void skb_warn_bad_offload(const struct sk_buff *skb)
3244 {
3245 	static const netdev_features_t null_features;
3246 	struct net_device *dev = skb->dev;
3247 	const char *name = "";
3248 
3249 	if (!net_ratelimit())
3250 		return;
3251 
3252 	if (dev) {
3253 		if (dev->dev.parent)
3254 			name = dev_driver_string(dev->dev.parent);
3255 		else
3256 			name = netdev_name(dev);
3257 	}
3258 	skb_dump(KERN_WARNING, skb, false);
3259 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3260 	     name, dev ? &dev->features : &null_features,
3261 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3262 }
3263 
3264 /*
3265  * Invalidate hardware checksum when packet is to be mangled, and
3266  * complete checksum manually on outgoing path.
3267  */
3268 int skb_checksum_help(struct sk_buff *skb)
3269 {
3270 	__wsum csum;
3271 	int ret = 0, offset;
3272 
3273 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3274 		goto out_set_summed;
3275 
3276 	if (unlikely(skb_is_gso(skb))) {
3277 		skb_warn_bad_offload(skb);
3278 		return -EINVAL;
3279 	}
3280 
3281 	/* Before computing a checksum, we should make sure no frag could
3282 	 * be modified by an external entity : checksum could be wrong.
3283 	 */
3284 	if (skb_has_shared_frag(skb)) {
3285 		ret = __skb_linearize(skb);
3286 		if (ret)
3287 			goto out;
3288 	}
3289 
3290 	offset = skb_checksum_start_offset(skb);
3291 	ret = -EINVAL;
3292 	if (unlikely(offset >= skb_headlen(skb))) {
3293 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3294 		WARN_ONCE(true, "offset (%d) >= skb_headlen() (%u)\n",
3295 			  offset, skb_headlen(skb));
3296 		goto out;
3297 	}
3298 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3299 
3300 	offset += skb->csum_offset;
3301 	if (unlikely(offset + sizeof(__sum16) > skb_headlen(skb))) {
3302 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3303 		WARN_ONCE(true, "offset+2 (%zu) > skb_headlen() (%u)\n",
3304 			  offset + sizeof(__sum16), skb_headlen(skb));
3305 		goto out;
3306 	}
3307 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3308 	if (ret)
3309 		goto out;
3310 
3311 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3312 out_set_summed:
3313 	skb->ip_summed = CHECKSUM_NONE;
3314 out:
3315 	return ret;
3316 }
3317 EXPORT_SYMBOL(skb_checksum_help);
3318 
3319 int skb_crc32c_csum_help(struct sk_buff *skb)
3320 {
3321 	__le32 crc32c_csum;
3322 	int ret = 0, offset, start;
3323 
3324 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3325 		goto out;
3326 
3327 	if (unlikely(skb_is_gso(skb)))
3328 		goto out;
3329 
3330 	/* Before computing a checksum, we should make sure no frag could
3331 	 * be modified by an external entity : checksum could be wrong.
3332 	 */
3333 	if (unlikely(skb_has_shared_frag(skb))) {
3334 		ret = __skb_linearize(skb);
3335 		if (ret)
3336 			goto out;
3337 	}
3338 	start = skb_checksum_start_offset(skb);
3339 	offset = start + offsetof(struct sctphdr, checksum);
3340 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3341 		ret = -EINVAL;
3342 		goto out;
3343 	}
3344 
3345 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3346 	if (ret)
3347 		goto out;
3348 
3349 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3350 						  skb->len - start, ~(__u32)0,
3351 						  crc32c_csum_stub));
3352 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3353 	skb_reset_csum_not_inet(skb);
3354 out:
3355 	return ret;
3356 }
3357 
3358 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3359 {
3360 	__be16 type = skb->protocol;
3361 
3362 	/* Tunnel gso handlers can set protocol to ethernet. */
3363 	if (type == htons(ETH_P_TEB)) {
3364 		struct ethhdr *eth;
3365 
3366 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3367 			return 0;
3368 
3369 		eth = (struct ethhdr *)skb->data;
3370 		type = eth->h_proto;
3371 	}
3372 
3373 	return vlan_get_protocol_and_depth(skb, type, depth);
3374 }
3375 
3376 
3377 /* Take action when hardware reception checksum errors are detected. */
3378 #ifdef CONFIG_BUG
3379 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3380 {
3381 	netdev_err(dev, "hw csum failure\n");
3382 	skb_dump(KERN_ERR, skb, true);
3383 	dump_stack();
3384 }
3385 
3386 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3387 {
3388 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3389 }
3390 EXPORT_SYMBOL(netdev_rx_csum_fault);
3391 #endif
3392 
3393 /* XXX: check that highmem exists at all on the given machine. */
3394 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3395 {
3396 #ifdef CONFIG_HIGHMEM
3397 	int i;
3398 
3399 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3400 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3401 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3402 
3403 			if (PageHighMem(skb_frag_page(frag)))
3404 				return 1;
3405 		}
3406 	}
3407 #endif
3408 	return 0;
3409 }
3410 
3411 /* If MPLS offload request, verify we are testing hardware MPLS features
3412  * instead of standard features for the netdev.
3413  */
3414 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3415 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3416 					   netdev_features_t features,
3417 					   __be16 type)
3418 {
3419 	if (eth_p_mpls(type))
3420 		features &= skb->dev->mpls_features;
3421 
3422 	return features;
3423 }
3424 #else
3425 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3426 					   netdev_features_t features,
3427 					   __be16 type)
3428 {
3429 	return features;
3430 }
3431 #endif
3432 
3433 static netdev_features_t harmonize_features(struct sk_buff *skb,
3434 	netdev_features_t features)
3435 {
3436 	__be16 type;
3437 
3438 	type = skb_network_protocol(skb, NULL);
3439 	features = net_mpls_features(skb, features, type);
3440 
3441 	if (skb->ip_summed != CHECKSUM_NONE &&
3442 	    !can_checksum_protocol(features, type)) {
3443 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3444 	}
3445 	if (illegal_highdma(skb->dev, skb))
3446 		features &= ~NETIF_F_SG;
3447 
3448 	return features;
3449 }
3450 
3451 netdev_features_t passthru_features_check(struct sk_buff *skb,
3452 					  struct net_device *dev,
3453 					  netdev_features_t features)
3454 {
3455 	return features;
3456 }
3457 EXPORT_SYMBOL(passthru_features_check);
3458 
3459 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3460 					     struct net_device *dev,
3461 					     netdev_features_t features)
3462 {
3463 	return vlan_features_check(skb, features);
3464 }
3465 
3466 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3467 					    struct net_device *dev,
3468 					    netdev_features_t features)
3469 {
3470 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3471 
3472 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3473 		return features & ~NETIF_F_GSO_MASK;
3474 
3475 	if (!skb_shinfo(skb)->gso_type) {
3476 		skb_warn_bad_offload(skb);
3477 		return features & ~NETIF_F_GSO_MASK;
3478 	}
3479 
3480 	/* Support for GSO partial features requires software
3481 	 * intervention before we can actually process the packets
3482 	 * so we need to strip support for any partial features now
3483 	 * and we can pull them back in after we have partially
3484 	 * segmented the frame.
3485 	 */
3486 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3487 		features &= ~dev->gso_partial_features;
3488 
3489 	/* Make sure to clear the IPv4 ID mangling feature if the
3490 	 * IPv4 header has the potential to be fragmented.
3491 	 */
3492 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3493 		struct iphdr *iph = skb->encapsulation ?
3494 				    inner_ip_hdr(skb) : ip_hdr(skb);
3495 
3496 		if (!(iph->frag_off & htons(IP_DF)))
3497 			features &= ~NETIF_F_TSO_MANGLEID;
3498 	}
3499 
3500 	return features;
3501 }
3502 
3503 netdev_features_t netif_skb_features(struct sk_buff *skb)
3504 {
3505 	struct net_device *dev = skb->dev;
3506 	netdev_features_t features = dev->features;
3507 
3508 	if (skb_is_gso(skb))
3509 		features = gso_features_check(skb, dev, features);
3510 
3511 	/* If encapsulation offload request, verify we are testing
3512 	 * hardware encapsulation features instead of standard
3513 	 * features for the netdev
3514 	 */
3515 	if (skb->encapsulation)
3516 		features &= dev->hw_enc_features;
3517 
3518 	if (skb_vlan_tagged(skb))
3519 		features = netdev_intersect_features(features,
3520 						     dev->vlan_features |
3521 						     NETIF_F_HW_VLAN_CTAG_TX |
3522 						     NETIF_F_HW_VLAN_STAG_TX);
3523 
3524 	if (dev->netdev_ops->ndo_features_check)
3525 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3526 								features);
3527 	else
3528 		features &= dflt_features_check(skb, dev, features);
3529 
3530 	return harmonize_features(skb, features);
3531 }
3532 EXPORT_SYMBOL(netif_skb_features);
3533 
3534 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3535 		    struct netdev_queue *txq, bool more)
3536 {
3537 	unsigned int len;
3538 	int rc;
3539 
3540 	if (dev_nit_active(dev))
3541 		dev_queue_xmit_nit(skb, dev);
3542 
3543 	len = skb->len;
3544 	trace_net_dev_start_xmit(skb, dev);
3545 	rc = netdev_start_xmit(skb, dev, txq, more);
3546 	trace_net_dev_xmit(skb, rc, dev, len);
3547 
3548 	return rc;
3549 }
3550 
3551 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3552 				    struct netdev_queue *txq, int *ret)
3553 {
3554 	struct sk_buff *skb = first;
3555 	int rc = NETDEV_TX_OK;
3556 
3557 	while (skb) {
3558 		struct sk_buff *next = skb->next;
3559 
3560 		skb_mark_not_on_list(skb);
3561 		rc = xmit_one(skb, dev, txq, next != NULL);
3562 		if (unlikely(!dev_xmit_complete(rc))) {
3563 			skb->next = next;
3564 			goto out;
3565 		}
3566 
3567 		skb = next;
3568 		if (netif_tx_queue_stopped(txq) && skb) {
3569 			rc = NETDEV_TX_BUSY;
3570 			break;
3571 		}
3572 	}
3573 
3574 out:
3575 	*ret = rc;
3576 	return skb;
3577 }
3578 
3579 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3580 					  netdev_features_t features)
3581 {
3582 	if (skb_vlan_tag_present(skb) &&
3583 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3584 		skb = __vlan_hwaccel_push_inside(skb);
3585 	return skb;
3586 }
3587 
3588 int skb_csum_hwoffload_help(struct sk_buff *skb,
3589 			    const netdev_features_t features)
3590 {
3591 	if (unlikely(skb_csum_is_sctp(skb)))
3592 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3593 			skb_crc32c_csum_help(skb);
3594 
3595 	if (features & NETIF_F_HW_CSUM)
3596 		return 0;
3597 
3598 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3599 		switch (skb->csum_offset) {
3600 		case offsetof(struct tcphdr, check):
3601 		case offsetof(struct udphdr, check):
3602 			return 0;
3603 		}
3604 	}
3605 
3606 	return skb_checksum_help(skb);
3607 }
3608 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3609 
3610 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3611 {
3612 	netdev_features_t features;
3613 
3614 	features = netif_skb_features(skb);
3615 	skb = validate_xmit_vlan(skb, features);
3616 	if (unlikely(!skb))
3617 		goto out_null;
3618 
3619 	skb = sk_validate_xmit_skb(skb, dev);
3620 	if (unlikely(!skb))
3621 		goto out_null;
3622 
3623 	if (netif_needs_gso(skb, features)) {
3624 		struct sk_buff *segs;
3625 
3626 		segs = skb_gso_segment(skb, features);
3627 		if (IS_ERR(segs)) {
3628 			goto out_kfree_skb;
3629 		} else if (segs) {
3630 			consume_skb(skb);
3631 			skb = segs;
3632 		}
3633 	} else {
3634 		if (skb_needs_linearize(skb, features) &&
3635 		    __skb_linearize(skb))
3636 			goto out_kfree_skb;
3637 
3638 		/* If packet is not checksummed and device does not
3639 		 * support checksumming for this protocol, complete
3640 		 * checksumming here.
3641 		 */
3642 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3643 			if (skb->encapsulation)
3644 				skb_set_inner_transport_header(skb,
3645 							       skb_checksum_start_offset(skb));
3646 			else
3647 				skb_set_transport_header(skb,
3648 							 skb_checksum_start_offset(skb));
3649 			if (skb_csum_hwoffload_help(skb, features))
3650 				goto out_kfree_skb;
3651 		}
3652 	}
3653 
3654 	skb = validate_xmit_xfrm(skb, features, again);
3655 
3656 	return skb;
3657 
3658 out_kfree_skb:
3659 	kfree_skb(skb);
3660 out_null:
3661 	dev_core_stats_tx_dropped_inc(dev);
3662 	return NULL;
3663 }
3664 
3665 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3666 {
3667 	struct sk_buff *next, *head = NULL, *tail;
3668 
3669 	for (; skb != NULL; skb = next) {
3670 		next = skb->next;
3671 		skb_mark_not_on_list(skb);
3672 
3673 		/* in case skb wont be segmented, point to itself */
3674 		skb->prev = skb;
3675 
3676 		skb = validate_xmit_skb(skb, dev, again);
3677 		if (!skb)
3678 			continue;
3679 
3680 		if (!head)
3681 			head = skb;
3682 		else
3683 			tail->next = skb;
3684 		/* If skb was segmented, skb->prev points to
3685 		 * the last segment. If not, it still contains skb.
3686 		 */
3687 		tail = skb->prev;
3688 	}
3689 	return head;
3690 }
3691 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3692 
3693 static void qdisc_pkt_len_init(struct sk_buff *skb)
3694 {
3695 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3696 
3697 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3698 
3699 	/* To get more precise estimation of bytes sent on wire,
3700 	 * we add to pkt_len the headers size of all segments
3701 	 */
3702 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3703 		u16 gso_segs = shinfo->gso_segs;
3704 		unsigned int hdr_len;
3705 
3706 		/* mac layer + network layer */
3707 		hdr_len = skb_transport_offset(skb);
3708 
3709 		/* + transport layer */
3710 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3711 			const struct tcphdr *th;
3712 			struct tcphdr _tcphdr;
3713 
3714 			th = skb_header_pointer(skb, hdr_len,
3715 						sizeof(_tcphdr), &_tcphdr);
3716 			if (likely(th))
3717 				hdr_len += __tcp_hdrlen(th);
3718 		} else {
3719 			struct udphdr _udphdr;
3720 
3721 			if (skb_header_pointer(skb, hdr_len,
3722 					       sizeof(_udphdr), &_udphdr))
3723 				hdr_len += sizeof(struct udphdr);
3724 		}
3725 
3726 		if (shinfo->gso_type & SKB_GSO_DODGY)
3727 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3728 						shinfo->gso_size);
3729 
3730 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3731 	}
3732 }
3733 
3734 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3735 			     struct sk_buff **to_free,
3736 			     struct netdev_queue *txq)
3737 {
3738 	int rc;
3739 
3740 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3741 	if (rc == NET_XMIT_SUCCESS)
3742 		trace_qdisc_enqueue(q, txq, skb);
3743 	return rc;
3744 }
3745 
3746 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3747 				 struct net_device *dev,
3748 				 struct netdev_queue *txq)
3749 {
3750 	spinlock_t *root_lock = qdisc_lock(q);
3751 	struct sk_buff *to_free = NULL;
3752 	bool contended;
3753 	int rc;
3754 
3755 	qdisc_calculate_pkt_len(skb, q);
3756 
3757 	if (q->flags & TCQ_F_NOLOCK) {
3758 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3759 		    qdisc_run_begin(q)) {
3760 			/* Retest nolock_qdisc_is_empty() within the protection
3761 			 * of q->seqlock to protect from racing with requeuing.
3762 			 */
3763 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3764 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3765 				__qdisc_run(q);
3766 				qdisc_run_end(q);
3767 
3768 				goto no_lock_out;
3769 			}
3770 
3771 			qdisc_bstats_cpu_update(q, skb);
3772 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3773 			    !nolock_qdisc_is_empty(q))
3774 				__qdisc_run(q);
3775 
3776 			qdisc_run_end(q);
3777 			return NET_XMIT_SUCCESS;
3778 		}
3779 
3780 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3781 		qdisc_run(q);
3782 
3783 no_lock_out:
3784 		if (unlikely(to_free))
3785 			kfree_skb_list_reason(to_free,
3786 					      SKB_DROP_REASON_QDISC_DROP);
3787 		return rc;
3788 	}
3789 
3790 	/*
3791 	 * Heuristic to force contended enqueues to serialize on a
3792 	 * separate lock before trying to get qdisc main lock.
3793 	 * This permits qdisc->running owner to get the lock more
3794 	 * often and dequeue packets faster.
3795 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3796 	 * and then other tasks will only enqueue packets. The packets will be
3797 	 * sent after the qdisc owner is scheduled again. To prevent this
3798 	 * scenario the task always serialize on the lock.
3799 	 */
3800 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3801 	if (unlikely(contended))
3802 		spin_lock(&q->busylock);
3803 
3804 	spin_lock(root_lock);
3805 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3806 		__qdisc_drop(skb, &to_free);
3807 		rc = NET_XMIT_DROP;
3808 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3809 		   qdisc_run_begin(q)) {
3810 		/*
3811 		 * This is a work-conserving queue; there are no old skbs
3812 		 * waiting to be sent out; and the qdisc is not running -
3813 		 * xmit the skb directly.
3814 		 */
3815 
3816 		qdisc_bstats_update(q, skb);
3817 
3818 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3819 			if (unlikely(contended)) {
3820 				spin_unlock(&q->busylock);
3821 				contended = false;
3822 			}
3823 			__qdisc_run(q);
3824 		}
3825 
3826 		qdisc_run_end(q);
3827 		rc = NET_XMIT_SUCCESS;
3828 	} else {
3829 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3830 		if (qdisc_run_begin(q)) {
3831 			if (unlikely(contended)) {
3832 				spin_unlock(&q->busylock);
3833 				contended = false;
3834 			}
3835 			__qdisc_run(q);
3836 			qdisc_run_end(q);
3837 		}
3838 	}
3839 	spin_unlock(root_lock);
3840 	if (unlikely(to_free))
3841 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3842 	if (unlikely(contended))
3843 		spin_unlock(&q->busylock);
3844 	return rc;
3845 }
3846 
3847 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3848 static void skb_update_prio(struct sk_buff *skb)
3849 {
3850 	const struct netprio_map *map;
3851 	const struct sock *sk;
3852 	unsigned int prioidx;
3853 
3854 	if (skb->priority)
3855 		return;
3856 	map = rcu_dereference_bh(skb->dev->priomap);
3857 	if (!map)
3858 		return;
3859 	sk = skb_to_full_sk(skb);
3860 	if (!sk)
3861 		return;
3862 
3863 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3864 
3865 	if (prioidx < map->priomap_len)
3866 		skb->priority = map->priomap[prioidx];
3867 }
3868 #else
3869 #define skb_update_prio(skb)
3870 #endif
3871 
3872 /**
3873  *	dev_loopback_xmit - loop back @skb
3874  *	@net: network namespace this loopback is happening in
3875  *	@sk:  sk needed to be a netfilter okfn
3876  *	@skb: buffer to transmit
3877  */
3878 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3879 {
3880 	skb_reset_mac_header(skb);
3881 	__skb_pull(skb, skb_network_offset(skb));
3882 	skb->pkt_type = PACKET_LOOPBACK;
3883 	if (skb->ip_summed == CHECKSUM_NONE)
3884 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3885 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3886 	skb_dst_force(skb);
3887 	netif_rx(skb);
3888 	return 0;
3889 }
3890 EXPORT_SYMBOL(dev_loopback_xmit);
3891 
3892 #ifdef CONFIG_NET_EGRESS
3893 static struct netdev_queue *
3894 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3895 {
3896 	int qm = skb_get_queue_mapping(skb);
3897 
3898 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3899 }
3900 
3901 static bool netdev_xmit_txqueue_skipped(void)
3902 {
3903 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3904 }
3905 
3906 void netdev_xmit_skip_txqueue(bool skip)
3907 {
3908 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3909 }
3910 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3911 #endif /* CONFIG_NET_EGRESS */
3912 
3913 #ifdef CONFIG_NET_XGRESS
3914 static int tc_run(struct tcx_entry *entry, struct sk_buff *skb,
3915 		  enum skb_drop_reason *drop_reason)
3916 {
3917 	int ret = TC_ACT_UNSPEC;
3918 #ifdef CONFIG_NET_CLS_ACT
3919 	struct mini_Qdisc *miniq = rcu_dereference_bh(entry->miniq);
3920 	struct tcf_result res;
3921 
3922 	if (!miniq)
3923 		return ret;
3924 
3925 	tc_skb_cb(skb)->mru = 0;
3926 	tc_skb_cb(skb)->post_ct = false;
3927 	res.drop_reason = *drop_reason;
3928 
3929 	mini_qdisc_bstats_cpu_update(miniq, skb);
3930 	ret = tcf_classify(skb, miniq->block, miniq->filter_list, &res, false);
3931 	/* Only tcf related quirks below. */
3932 	switch (ret) {
3933 	case TC_ACT_SHOT:
3934 		*drop_reason = res.drop_reason;
3935 		mini_qdisc_qstats_cpu_drop(miniq);
3936 		break;
3937 	case TC_ACT_OK:
3938 	case TC_ACT_RECLASSIFY:
3939 		skb->tc_index = TC_H_MIN(res.classid);
3940 		break;
3941 	}
3942 #endif /* CONFIG_NET_CLS_ACT */
3943 	return ret;
3944 }
3945 
3946 static DEFINE_STATIC_KEY_FALSE(tcx_needed_key);
3947 
3948 void tcx_inc(void)
3949 {
3950 	static_branch_inc(&tcx_needed_key);
3951 }
3952 
3953 void tcx_dec(void)
3954 {
3955 	static_branch_dec(&tcx_needed_key);
3956 }
3957 
3958 static __always_inline enum tcx_action_base
3959 tcx_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb,
3960 	const bool needs_mac)
3961 {
3962 	const struct bpf_mprog_fp *fp;
3963 	const struct bpf_prog *prog;
3964 	int ret = TCX_NEXT;
3965 
3966 	if (needs_mac)
3967 		__skb_push(skb, skb->mac_len);
3968 	bpf_mprog_foreach_prog(entry, fp, prog) {
3969 		bpf_compute_data_pointers(skb);
3970 		ret = bpf_prog_run(prog, skb);
3971 		if (ret != TCX_NEXT)
3972 			break;
3973 	}
3974 	if (needs_mac)
3975 		__skb_pull(skb, skb->mac_len);
3976 	return tcx_action_code(skb, ret);
3977 }
3978 
3979 static __always_inline struct sk_buff *
3980 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
3981 		   struct net_device *orig_dev, bool *another)
3982 {
3983 	struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
3984 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_INGRESS;
3985 	int sch_ret;
3986 
3987 	if (!entry)
3988 		return skb;
3989 	if (*pt_prev) {
3990 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
3991 		*pt_prev = NULL;
3992 	}
3993 
3994 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3995 	tcx_set_ingress(skb, true);
3996 
3997 	if (static_branch_unlikely(&tcx_needed_key)) {
3998 		sch_ret = tcx_run(entry, skb, true);
3999 		if (sch_ret != TC_ACT_UNSPEC)
4000 			goto ingress_verdict;
4001 	}
4002 	sch_ret = tc_run(tcx_entry(entry), skb, &drop_reason);
4003 ingress_verdict:
4004 	switch (sch_ret) {
4005 	case TC_ACT_REDIRECT:
4006 		/* skb_mac_header check was done by BPF, so we can safely
4007 		 * push the L2 header back before redirecting to another
4008 		 * netdev.
4009 		 */
4010 		__skb_push(skb, skb->mac_len);
4011 		if (skb_do_redirect(skb) == -EAGAIN) {
4012 			__skb_pull(skb, skb->mac_len);
4013 			*another = true;
4014 			break;
4015 		}
4016 		*ret = NET_RX_SUCCESS;
4017 		return NULL;
4018 	case TC_ACT_SHOT:
4019 		kfree_skb_reason(skb, drop_reason);
4020 		*ret = NET_RX_DROP;
4021 		return NULL;
4022 	/* used by tc_run */
4023 	case TC_ACT_STOLEN:
4024 	case TC_ACT_QUEUED:
4025 	case TC_ACT_TRAP:
4026 		consume_skb(skb);
4027 		fallthrough;
4028 	case TC_ACT_CONSUMED:
4029 		*ret = NET_RX_SUCCESS;
4030 		return NULL;
4031 	}
4032 
4033 	return skb;
4034 }
4035 
4036 static __always_inline struct sk_buff *
4037 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4038 {
4039 	struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
4040 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_EGRESS;
4041 	int sch_ret;
4042 
4043 	if (!entry)
4044 		return skb;
4045 
4046 	/* qdisc_skb_cb(skb)->pkt_len & tcx_set_ingress() was
4047 	 * already set by the caller.
4048 	 */
4049 	if (static_branch_unlikely(&tcx_needed_key)) {
4050 		sch_ret = tcx_run(entry, skb, false);
4051 		if (sch_ret != TC_ACT_UNSPEC)
4052 			goto egress_verdict;
4053 	}
4054 	sch_ret = tc_run(tcx_entry(entry), skb, &drop_reason);
4055 egress_verdict:
4056 	switch (sch_ret) {
4057 	case TC_ACT_REDIRECT:
4058 		/* No need to push/pop skb's mac_header here on egress! */
4059 		skb_do_redirect(skb);
4060 		*ret = NET_XMIT_SUCCESS;
4061 		return NULL;
4062 	case TC_ACT_SHOT:
4063 		kfree_skb_reason(skb, drop_reason);
4064 		*ret = NET_XMIT_DROP;
4065 		return NULL;
4066 	/* used by tc_run */
4067 	case TC_ACT_STOLEN:
4068 	case TC_ACT_QUEUED:
4069 	case TC_ACT_TRAP:
4070 		consume_skb(skb);
4071 		fallthrough;
4072 	case TC_ACT_CONSUMED:
4073 		*ret = NET_XMIT_SUCCESS;
4074 		return NULL;
4075 	}
4076 
4077 	return skb;
4078 }
4079 #else
4080 static __always_inline struct sk_buff *
4081 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4082 		   struct net_device *orig_dev, bool *another)
4083 {
4084 	return skb;
4085 }
4086 
4087 static __always_inline struct sk_buff *
4088 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4089 {
4090 	return skb;
4091 }
4092 #endif /* CONFIG_NET_XGRESS */
4093 
4094 #ifdef CONFIG_XPS
4095 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4096 			       struct xps_dev_maps *dev_maps, unsigned int tci)
4097 {
4098 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
4099 	struct xps_map *map;
4100 	int queue_index = -1;
4101 
4102 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4103 		return queue_index;
4104 
4105 	tci *= dev_maps->num_tc;
4106 	tci += tc;
4107 
4108 	map = rcu_dereference(dev_maps->attr_map[tci]);
4109 	if (map) {
4110 		if (map->len == 1)
4111 			queue_index = map->queues[0];
4112 		else
4113 			queue_index = map->queues[reciprocal_scale(
4114 						skb_get_hash(skb), map->len)];
4115 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4116 			queue_index = -1;
4117 	}
4118 	return queue_index;
4119 }
4120 #endif
4121 
4122 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4123 			 struct sk_buff *skb)
4124 {
4125 #ifdef CONFIG_XPS
4126 	struct xps_dev_maps *dev_maps;
4127 	struct sock *sk = skb->sk;
4128 	int queue_index = -1;
4129 
4130 	if (!static_key_false(&xps_needed))
4131 		return -1;
4132 
4133 	rcu_read_lock();
4134 	if (!static_key_false(&xps_rxqs_needed))
4135 		goto get_cpus_map;
4136 
4137 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4138 	if (dev_maps) {
4139 		int tci = sk_rx_queue_get(sk);
4140 
4141 		if (tci >= 0)
4142 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4143 							  tci);
4144 	}
4145 
4146 get_cpus_map:
4147 	if (queue_index < 0) {
4148 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4149 		if (dev_maps) {
4150 			unsigned int tci = skb->sender_cpu - 1;
4151 
4152 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4153 							  tci);
4154 		}
4155 	}
4156 	rcu_read_unlock();
4157 
4158 	return queue_index;
4159 #else
4160 	return -1;
4161 #endif
4162 }
4163 
4164 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4165 		     struct net_device *sb_dev)
4166 {
4167 	return 0;
4168 }
4169 EXPORT_SYMBOL(dev_pick_tx_zero);
4170 
4171 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4172 		       struct net_device *sb_dev)
4173 {
4174 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4175 }
4176 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4177 
4178 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4179 		     struct net_device *sb_dev)
4180 {
4181 	struct sock *sk = skb->sk;
4182 	int queue_index = sk_tx_queue_get(sk);
4183 
4184 	sb_dev = sb_dev ? : dev;
4185 
4186 	if (queue_index < 0 || skb->ooo_okay ||
4187 	    queue_index >= dev->real_num_tx_queues) {
4188 		int new_index = get_xps_queue(dev, sb_dev, skb);
4189 
4190 		if (new_index < 0)
4191 			new_index = skb_tx_hash(dev, sb_dev, skb);
4192 
4193 		if (queue_index != new_index && sk &&
4194 		    sk_fullsock(sk) &&
4195 		    rcu_access_pointer(sk->sk_dst_cache))
4196 			sk_tx_queue_set(sk, new_index);
4197 
4198 		queue_index = new_index;
4199 	}
4200 
4201 	return queue_index;
4202 }
4203 EXPORT_SYMBOL(netdev_pick_tx);
4204 
4205 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4206 					 struct sk_buff *skb,
4207 					 struct net_device *sb_dev)
4208 {
4209 	int queue_index = 0;
4210 
4211 #ifdef CONFIG_XPS
4212 	u32 sender_cpu = skb->sender_cpu - 1;
4213 
4214 	if (sender_cpu >= (u32)NR_CPUS)
4215 		skb->sender_cpu = raw_smp_processor_id() + 1;
4216 #endif
4217 
4218 	if (dev->real_num_tx_queues != 1) {
4219 		const struct net_device_ops *ops = dev->netdev_ops;
4220 
4221 		if (ops->ndo_select_queue)
4222 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4223 		else
4224 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4225 
4226 		queue_index = netdev_cap_txqueue(dev, queue_index);
4227 	}
4228 
4229 	skb_set_queue_mapping(skb, queue_index);
4230 	return netdev_get_tx_queue(dev, queue_index);
4231 }
4232 
4233 /**
4234  * __dev_queue_xmit() - transmit a buffer
4235  * @skb:	buffer to transmit
4236  * @sb_dev:	suboordinate device used for L2 forwarding offload
4237  *
4238  * Queue a buffer for transmission to a network device. The caller must
4239  * have set the device and priority and built the buffer before calling
4240  * this function. The function can be called from an interrupt.
4241  *
4242  * When calling this method, interrupts MUST be enabled. This is because
4243  * the BH enable code must have IRQs enabled so that it will not deadlock.
4244  *
4245  * Regardless of the return value, the skb is consumed, so it is currently
4246  * difficult to retry a send to this method. (You can bump the ref count
4247  * before sending to hold a reference for retry if you are careful.)
4248  *
4249  * Return:
4250  * * 0				- buffer successfully transmitted
4251  * * positive qdisc return code	- NET_XMIT_DROP etc.
4252  * * negative errno		- other errors
4253  */
4254 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4255 {
4256 	struct net_device *dev = skb->dev;
4257 	struct netdev_queue *txq = NULL;
4258 	struct Qdisc *q;
4259 	int rc = -ENOMEM;
4260 	bool again = false;
4261 
4262 	skb_reset_mac_header(skb);
4263 	skb_assert_len(skb);
4264 
4265 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4266 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4267 
4268 	/* Disable soft irqs for various locks below. Also
4269 	 * stops preemption for RCU.
4270 	 */
4271 	rcu_read_lock_bh();
4272 
4273 	skb_update_prio(skb);
4274 
4275 	qdisc_pkt_len_init(skb);
4276 	tcx_set_ingress(skb, false);
4277 #ifdef CONFIG_NET_EGRESS
4278 	if (static_branch_unlikely(&egress_needed_key)) {
4279 		if (nf_hook_egress_active()) {
4280 			skb = nf_hook_egress(skb, &rc, dev);
4281 			if (!skb)
4282 				goto out;
4283 		}
4284 
4285 		netdev_xmit_skip_txqueue(false);
4286 
4287 		nf_skip_egress(skb, true);
4288 		skb = sch_handle_egress(skb, &rc, dev);
4289 		if (!skb)
4290 			goto out;
4291 		nf_skip_egress(skb, false);
4292 
4293 		if (netdev_xmit_txqueue_skipped())
4294 			txq = netdev_tx_queue_mapping(dev, skb);
4295 	}
4296 #endif
4297 	/* If device/qdisc don't need skb->dst, release it right now while
4298 	 * its hot in this cpu cache.
4299 	 */
4300 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4301 		skb_dst_drop(skb);
4302 	else
4303 		skb_dst_force(skb);
4304 
4305 	if (!txq)
4306 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4307 
4308 	q = rcu_dereference_bh(txq->qdisc);
4309 
4310 	trace_net_dev_queue(skb);
4311 	if (q->enqueue) {
4312 		rc = __dev_xmit_skb(skb, q, dev, txq);
4313 		goto out;
4314 	}
4315 
4316 	/* The device has no queue. Common case for software devices:
4317 	 * loopback, all the sorts of tunnels...
4318 
4319 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4320 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4321 	 * counters.)
4322 	 * However, it is possible, that they rely on protection
4323 	 * made by us here.
4324 
4325 	 * Check this and shot the lock. It is not prone from deadlocks.
4326 	 *Either shot noqueue qdisc, it is even simpler 8)
4327 	 */
4328 	if (dev->flags & IFF_UP) {
4329 		int cpu = smp_processor_id(); /* ok because BHs are off */
4330 
4331 		/* Other cpus might concurrently change txq->xmit_lock_owner
4332 		 * to -1 or to their cpu id, but not to our id.
4333 		 */
4334 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4335 			if (dev_xmit_recursion())
4336 				goto recursion_alert;
4337 
4338 			skb = validate_xmit_skb(skb, dev, &again);
4339 			if (!skb)
4340 				goto out;
4341 
4342 			HARD_TX_LOCK(dev, txq, cpu);
4343 
4344 			if (!netif_xmit_stopped(txq)) {
4345 				dev_xmit_recursion_inc();
4346 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4347 				dev_xmit_recursion_dec();
4348 				if (dev_xmit_complete(rc)) {
4349 					HARD_TX_UNLOCK(dev, txq);
4350 					goto out;
4351 				}
4352 			}
4353 			HARD_TX_UNLOCK(dev, txq);
4354 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4355 					     dev->name);
4356 		} else {
4357 			/* Recursion is detected! It is possible,
4358 			 * unfortunately
4359 			 */
4360 recursion_alert:
4361 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4362 					     dev->name);
4363 		}
4364 	}
4365 
4366 	rc = -ENETDOWN;
4367 	rcu_read_unlock_bh();
4368 
4369 	dev_core_stats_tx_dropped_inc(dev);
4370 	kfree_skb_list(skb);
4371 	return rc;
4372 out:
4373 	rcu_read_unlock_bh();
4374 	return rc;
4375 }
4376 EXPORT_SYMBOL(__dev_queue_xmit);
4377 
4378 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4379 {
4380 	struct net_device *dev = skb->dev;
4381 	struct sk_buff *orig_skb = skb;
4382 	struct netdev_queue *txq;
4383 	int ret = NETDEV_TX_BUSY;
4384 	bool again = false;
4385 
4386 	if (unlikely(!netif_running(dev) ||
4387 		     !netif_carrier_ok(dev)))
4388 		goto drop;
4389 
4390 	skb = validate_xmit_skb_list(skb, dev, &again);
4391 	if (skb != orig_skb)
4392 		goto drop;
4393 
4394 	skb_set_queue_mapping(skb, queue_id);
4395 	txq = skb_get_tx_queue(dev, skb);
4396 
4397 	local_bh_disable();
4398 
4399 	dev_xmit_recursion_inc();
4400 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4401 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4402 		ret = netdev_start_xmit(skb, dev, txq, false);
4403 	HARD_TX_UNLOCK(dev, txq);
4404 	dev_xmit_recursion_dec();
4405 
4406 	local_bh_enable();
4407 	return ret;
4408 drop:
4409 	dev_core_stats_tx_dropped_inc(dev);
4410 	kfree_skb_list(skb);
4411 	return NET_XMIT_DROP;
4412 }
4413 EXPORT_SYMBOL(__dev_direct_xmit);
4414 
4415 /*************************************************************************
4416  *			Receiver routines
4417  *************************************************************************/
4418 
4419 int netdev_max_backlog __read_mostly = 1000;
4420 EXPORT_SYMBOL(netdev_max_backlog);
4421 
4422 int netdev_tstamp_prequeue __read_mostly = 1;
4423 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4424 int netdev_budget __read_mostly = 300;
4425 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4426 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4427 int weight_p __read_mostly = 64;           /* old backlog weight */
4428 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4429 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4430 int dev_rx_weight __read_mostly = 64;
4431 int dev_tx_weight __read_mostly = 64;
4432 
4433 /* Called with irq disabled */
4434 static inline void ____napi_schedule(struct softnet_data *sd,
4435 				     struct napi_struct *napi)
4436 {
4437 	struct task_struct *thread;
4438 
4439 	lockdep_assert_irqs_disabled();
4440 
4441 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4442 		/* Paired with smp_mb__before_atomic() in
4443 		 * napi_enable()/dev_set_threaded().
4444 		 * Use READ_ONCE() to guarantee a complete
4445 		 * read on napi->thread. Only call
4446 		 * wake_up_process() when it's not NULL.
4447 		 */
4448 		thread = READ_ONCE(napi->thread);
4449 		if (thread) {
4450 			/* Avoid doing set_bit() if the thread is in
4451 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4452 			 * makes sure to proceed with napi polling
4453 			 * if the thread is explicitly woken from here.
4454 			 */
4455 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4456 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4457 			wake_up_process(thread);
4458 			return;
4459 		}
4460 	}
4461 
4462 	list_add_tail(&napi->poll_list, &sd->poll_list);
4463 	WRITE_ONCE(napi->list_owner, smp_processor_id());
4464 	/* If not called from net_rx_action()
4465 	 * we have to raise NET_RX_SOFTIRQ.
4466 	 */
4467 	if (!sd->in_net_rx_action)
4468 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4469 }
4470 
4471 #ifdef CONFIG_RPS
4472 
4473 /* One global table that all flow-based protocols share. */
4474 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4475 EXPORT_SYMBOL(rps_sock_flow_table);
4476 u32 rps_cpu_mask __read_mostly;
4477 EXPORT_SYMBOL(rps_cpu_mask);
4478 
4479 struct static_key_false rps_needed __read_mostly;
4480 EXPORT_SYMBOL(rps_needed);
4481 struct static_key_false rfs_needed __read_mostly;
4482 EXPORT_SYMBOL(rfs_needed);
4483 
4484 static struct rps_dev_flow *
4485 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4486 	    struct rps_dev_flow *rflow, u16 next_cpu)
4487 {
4488 	if (next_cpu < nr_cpu_ids) {
4489 #ifdef CONFIG_RFS_ACCEL
4490 		struct netdev_rx_queue *rxqueue;
4491 		struct rps_dev_flow_table *flow_table;
4492 		struct rps_dev_flow *old_rflow;
4493 		u32 flow_id;
4494 		u16 rxq_index;
4495 		int rc;
4496 
4497 		/* Should we steer this flow to a different hardware queue? */
4498 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4499 		    !(dev->features & NETIF_F_NTUPLE))
4500 			goto out;
4501 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4502 		if (rxq_index == skb_get_rx_queue(skb))
4503 			goto out;
4504 
4505 		rxqueue = dev->_rx + rxq_index;
4506 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4507 		if (!flow_table)
4508 			goto out;
4509 		flow_id = skb_get_hash(skb) & flow_table->mask;
4510 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4511 							rxq_index, flow_id);
4512 		if (rc < 0)
4513 			goto out;
4514 		old_rflow = rflow;
4515 		rflow = &flow_table->flows[flow_id];
4516 		rflow->filter = rc;
4517 		if (old_rflow->filter == rflow->filter)
4518 			old_rflow->filter = RPS_NO_FILTER;
4519 	out:
4520 #endif
4521 		rflow->last_qtail =
4522 			per_cpu(softnet_data, next_cpu).input_queue_head;
4523 	}
4524 
4525 	rflow->cpu = next_cpu;
4526 	return rflow;
4527 }
4528 
4529 /*
4530  * get_rps_cpu is called from netif_receive_skb and returns the target
4531  * CPU from the RPS map of the receiving queue for a given skb.
4532  * rcu_read_lock must be held on entry.
4533  */
4534 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4535 		       struct rps_dev_flow **rflowp)
4536 {
4537 	const struct rps_sock_flow_table *sock_flow_table;
4538 	struct netdev_rx_queue *rxqueue = dev->_rx;
4539 	struct rps_dev_flow_table *flow_table;
4540 	struct rps_map *map;
4541 	int cpu = -1;
4542 	u32 tcpu;
4543 	u32 hash;
4544 
4545 	if (skb_rx_queue_recorded(skb)) {
4546 		u16 index = skb_get_rx_queue(skb);
4547 
4548 		if (unlikely(index >= dev->real_num_rx_queues)) {
4549 			WARN_ONCE(dev->real_num_rx_queues > 1,
4550 				  "%s received packet on queue %u, but number "
4551 				  "of RX queues is %u\n",
4552 				  dev->name, index, dev->real_num_rx_queues);
4553 			goto done;
4554 		}
4555 		rxqueue += index;
4556 	}
4557 
4558 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4559 
4560 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4561 	map = rcu_dereference(rxqueue->rps_map);
4562 	if (!flow_table && !map)
4563 		goto done;
4564 
4565 	skb_reset_network_header(skb);
4566 	hash = skb_get_hash(skb);
4567 	if (!hash)
4568 		goto done;
4569 
4570 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4571 	if (flow_table && sock_flow_table) {
4572 		struct rps_dev_flow *rflow;
4573 		u32 next_cpu;
4574 		u32 ident;
4575 
4576 		/* First check into global flow table if there is a match.
4577 		 * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
4578 		 */
4579 		ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
4580 		if ((ident ^ hash) & ~rps_cpu_mask)
4581 			goto try_rps;
4582 
4583 		next_cpu = ident & rps_cpu_mask;
4584 
4585 		/* OK, now we know there is a match,
4586 		 * we can look at the local (per receive queue) flow table
4587 		 */
4588 		rflow = &flow_table->flows[hash & flow_table->mask];
4589 		tcpu = rflow->cpu;
4590 
4591 		/*
4592 		 * If the desired CPU (where last recvmsg was done) is
4593 		 * different from current CPU (one in the rx-queue flow
4594 		 * table entry), switch if one of the following holds:
4595 		 *   - Current CPU is unset (>= nr_cpu_ids).
4596 		 *   - Current CPU is offline.
4597 		 *   - The current CPU's queue tail has advanced beyond the
4598 		 *     last packet that was enqueued using this table entry.
4599 		 *     This guarantees that all previous packets for the flow
4600 		 *     have been dequeued, thus preserving in order delivery.
4601 		 */
4602 		if (unlikely(tcpu != next_cpu) &&
4603 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4604 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4605 		      rflow->last_qtail)) >= 0)) {
4606 			tcpu = next_cpu;
4607 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4608 		}
4609 
4610 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4611 			*rflowp = rflow;
4612 			cpu = tcpu;
4613 			goto done;
4614 		}
4615 	}
4616 
4617 try_rps:
4618 
4619 	if (map) {
4620 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4621 		if (cpu_online(tcpu)) {
4622 			cpu = tcpu;
4623 			goto done;
4624 		}
4625 	}
4626 
4627 done:
4628 	return cpu;
4629 }
4630 
4631 #ifdef CONFIG_RFS_ACCEL
4632 
4633 /**
4634  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4635  * @dev: Device on which the filter was set
4636  * @rxq_index: RX queue index
4637  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4638  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4639  *
4640  * Drivers that implement ndo_rx_flow_steer() should periodically call
4641  * this function for each installed filter and remove the filters for
4642  * which it returns %true.
4643  */
4644 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4645 			 u32 flow_id, u16 filter_id)
4646 {
4647 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4648 	struct rps_dev_flow_table *flow_table;
4649 	struct rps_dev_flow *rflow;
4650 	bool expire = true;
4651 	unsigned int cpu;
4652 
4653 	rcu_read_lock();
4654 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4655 	if (flow_table && flow_id <= flow_table->mask) {
4656 		rflow = &flow_table->flows[flow_id];
4657 		cpu = READ_ONCE(rflow->cpu);
4658 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4659 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4660 			   rflow->last_qtail) <
4661 		     (int)(10 * flow_table->mask)))
4662 			expire = false;
4663 	}
4664 	rcu_read_unlock();
4665 	return expire;
4666 }
4667 EXPORT_SYMBOL(rps_may_expire_flow);
4668 
4669 #endif /* CONFIG_RFS_ACCEL */
4670 
4671 /* Called from hardirq (IPI) context */
4672 static void rps_trigger_softirq(void *data)
4673 {
4674 	struct softnet_data *sd = data;
4675 
4676 	____napi_schedule(sd, &sd->backlog);
4677 	sd->received_rps++;
4678 }
4679 
4680 #endif /* CONFIG_RPS */
4681 
4682 /* Called from hardirq (IPI) context */
4683 static void trigger_rx_softirq(void *data)
4684 {
4685 	struct softnet_data *sd = data;
4686 
4687 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4688 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4689 }
4690 
4691 /*
4692  * After we queued a packet into sd->input_pkt_queue,
4693  * we need to make sure this queue is serviced soon.
4694  *
4695  * - If this is another cpu queue, link it to our rps_ipi_list,
4696  *   and make sure we will process rps_ipi_list from net_rx_action().
4697  *
4698  * - If this is our own queue, NAPI schedule our backlog.
4699  *   Note that this also raises NET_RX_SOFTIRQ.
4700  */
4701 static void napi_schedule_rps(struct softnet_data *sd)
4702 {
4703 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4704 
4705 #ifdef CONFIG_RPS
4706 	if (sd != mysd) {
4707 		sd->rps_ipi_next = mysd->rps_ipi_list;
4708 		mysd->rps_ipi_list = sd;
4709 
4710 		/* If not called from net_rx_action() or napi_threaded_poll()
4711 		 * we have to raise NET_RX_SOFTIRQ.
4712 		 */
4713 		if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
4714 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4715 		return;
4716 	}
4717 #endif /* CONFIG_RPS */
4718 	__napi_schedule_irqoff(&mysd->backlog);
4719 }
4720 
4721 #ifdef CONFIG_NET_FLOW_LIMIT
4722 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4723 #endif
4724 
4725 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4726 {
4727 #ifdef CONFIG_NET_FLOW_LIMIT
4728 	struct sd_flow_limit *fl;
4729 	struct softnet_data *sd;
4730 	unsigned int old_flow, new_flow;
4731 
4732 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4733 		return false;
4734 
4735 	sd = this_cpu_ptr(&softnet_data);
4736 
4737 	rcu_read_lock();
4738 	fl = rcu_dereference(sd->flow_limit);
4739 	if (fl) {
4740 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4741 		old_flow = fl->history[fl->history_head];
4742 		fl->history[fl->history_head] = new_flow;
4743 
4744 		fl->history_head++;
4745 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4746 
4747 		if (likely(fl->buckets[old_flow]))
4748 			fl->buckets[old_flow]--;
4749 
4750 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4751 			fl->count++;
4752 			rcu_read_unlock();
4753 			return true;
4754 		}
4755 	}
4756 	rcu_read_unlock();
4757 #endif
4758 	return false;
4759 }
4760 
4761 /*
4762  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4763  * queue (may be a remote CPU queue).
4764  */
4765 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4766 			      unsigned int *qtail)
4767 {
4768 	enum skb_drop_reason reason;
4769 	struct softnet_data *sd;
4770 	unsigned long flags;
4771 	unsigned int qlen;
4772 
4773 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4774 	sd = &per_cpu(softnet_data, cpu);
4775 
4776 	rps_lock_irqsave(sd, &flags);
4777 	if (!netif_running(skb->dev))
4778 		goto drop;
4779 	qlen = skb_queue_len(&sd->input_pkt_queue);
4780 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4781 		if (qlen) {
4782 enqueue:
4783 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4784 			input_queue_tail_incr_save(sd, qtail);
4785 			rps_unlock_irq_restore(sd, &flags);
4786 			return NET_RX_SUCCESS;
4787 		}
4788 
4789 		/* Schedule NAPI for backlog device
4790 		 * We can use non atomic operation since we own the queue lock
4791 		 */
4792 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4793 			napi_schedule_rps(sd);
4794 		goto enqueue;
4795 	}
4796 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4797 
4798 drop:
4799 	sd->dropped++;
4800 	rps_unlock_irq_restore(sd, &flags);
4801 
4802 	dev_core_stats_rx_dropped_inc(skb->dev);
4803 	kfree_skb_reason(skb, reason);
4804 	return NET_RX_DROP;
4805 }
4806 
4807 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4808 {
4809 	struct net_device *dev = skb->dev;
4810 	struct netdev_rx_queue *rxqueue;
4811 
4812 	rxqueue = dev->_rx;
4813 
4814 	if (skb_rx_queue_recorded(skb)) {
4815 		u16 index = skb_get_rx_queue(skb);
4816 
4817 		if (unlikely(index >= dev->real_num_rx_queues)) {
4818 			WARN_ONCE(dev->real_num_rx_queues > 1,
4819 				  "%s received packet on queue %u, but number "
4820 				  "of RX queues is %u\n",
4821 				  dev->name, index, dev->real_num_rx_queues);
4822 
4823 			return rxqueue; /* Return first rxqueue */
4824 		}
4825 		rxqueue += index;
4826 	}
4827 	return rxqueue;
4828 }
4829 
4830 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4831 			     struct bpf_prog *xdp_prog)
4832 {
4833 	void *orig_data, *orig_data_end, *hard_start;
4834 	struct netdev_rx_queue *rxqueue;
4835 	bool orig_bcast, orig_host;
4836 	u32 mac_len, frame_sz;
4837 	__be16 orig_eth_type;
4838 	struct ethhdr *eth;
4839 	u32 metalen, act;
4840 	int off;
4841 
4842 	/* The XDP program wants to see the packet starting at the MAC
4843 	 * header.
4844 	 */
4845 	mac_len = skb->data - skb_mac_header(skb);
4846 	hard_start = skb->data - skb_headroom(skb);
4847 
4848 	/* SKB "head" area always have tailroom for skb_shared_info */
4849 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4850 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4851 
4852 	rxqueue = netif_get_rxqueue(skb);
4853 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4854 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4855 			 skb_headlen(skb) + mac_len, true);
4856 
4857 	orig_data_end = xdp->data_end;
4858 	orig_data = xdp->data;
4859 	eth = (struct ethhdr *)xdp->data;
4860 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4861 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4862 	orig_eth_type = eth->h_proto;
4863 
4864 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4865 
4866 	/* check if bpf_xdp_adjust_head was used */
4867 	off = xdp->data - orig_data;
4868 	if (off) {
4869 		if (off > 0)
4870 			__skb_pull(skb, off);
4871 		else if (off < 0)
4872 			__skb_push(skb, -off);
4873 
4874 		skb->mac_header += off;
4875 		skb_reset_network_header(skb);
4876 	}
4877 
4878 	/* check if bpf_xdp_adjust_tail was used */
4879 	off = xdp->data_end - orig_data_end;
4880 	if (off != 0) {
4881 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4882 		skb->len += off; /* positive on grow, negative on shrink */
4883 	}
4884 
4885 	/* check if XDP changed eth hdr such SKB needs update */
4886 	eth = (struct ethhdr *)xdp->data;
4887 	if ((orig_eth_type != eth->h_proto) ||
4888 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4889 						  skb->dev->dev_addr)) ||
4890 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4891 		__skb_push(skb, ETH_HLEN);
4892 		skb->pkt_type = PACKET_HOST;
4893 		skb->protocol = eth_type_trans(skb, skb->dev);
4894 	}
4895 
4896 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4897 	 * before calling us again on redirect path. We do not call do_redirect
4898 	 * as we leave that up to the caller.
4899 	 *
4900 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4901 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4902 	 */
4903 	switch (act) {
4904 	case XDP_REDIRECT:
4905 	case XDP_TX:
4906 		__skb_push(skb, mac_len);
4907 		break;
4908 	case XDP_PASS:
4909 		metalen = xdp->data - xdp->data_meta;
4910 		if (metalen)
4911 			skb_metadata_set(skb, metalen);
4912 		break;
4913 	}
4914 
4915 	return act;
4916 }
4917 
4918 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4919 				     struct xdp_buff *xdp,
4920 				     struct bpf_prog *xdp_prog)
4921 {
4922 	u32 act = XDP_DROP;
4923 
4924 	/* Reinjected packets coming from act_mirred or similar should
4925 	 * not get XDP generic processing.
4926 	 */
4927 	if (skb_is_redirected(skb))
4928 		return XDP_PASS;
4929 
4930 	/* XDP packets must be linear and must have sufficient headroom
4931 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4932 	 * native XDP provides, thus we need to do it here as well.
4933 	 */
4934 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4935 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4936 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4937 		int troom = skb->tail + skb->data_len - skb->end;
4938 
4939 		/* In case we have to go down the path and also linearize,
4940 		 * then lets do the pskb_expand_head() work just once here.
4941 		 */
4942 		if (pskb_expand_head(skb,
4943 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4944 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4945 			goto do_drop;
4946 		if (skb_linearize(skb))
4947 			goto do_drop;
4948 	}
4949 
4950 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4951 	switch (act) {
4952 	case XDP_REDIRECT:
4953 	case XDP_TX:
4954 	case XDP_PASS:
4955 		break;
4956 	default:
4957 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4958 		fallthrough;
4959 	case XDP_ABORTED:
4960 		trace_xdp_exception(skb->dev, xdp_prog, act);
4961 		fallthrough;
4962 	case XDP_DROP:
4963 	do_drop:
4964 		kfree_skb(skb);
4965 		break;
4966 	}
4967 
4968 	return act;
4969 }
4970 
4971 /* When doing generic XDP we have to bypass the qdisc layer and the
4972  * network taps in order to match in-driver-XDP behavior. This also means
4973  * that XDP packets are able to starve other packets going through a qdisc,
4974  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4975  * queues, so they do not have this starvation issue.
4976  */
4977 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4978 {
4979 	struct net_device *dev = skb->dev;
4980 	struct netdev_queue *txq;
4981 	bool free_skb = true;
4982 	int cpu, rc;
4983 
4984 	txq = netdev_core_pick_tx(dev, skb, NULL);
4985 	cpu = smp_processor_id();
4986 	HARD_TX_LOCK(dev, txq, cpu);
4987 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4988 		rc = netdev_start_xmit(skb, dev, txq, 0);
4989 		if (dev_xmit_complete(rc))
4990 			free_skb = false;
4991 	}
4992 	HARD_TX_UNLOCK(dev, txq);
4993 	if (free_skb) {
4994 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4995 		dev_core_stats_tx_dropped_inc(dev);
4996 		kfree_skb(skb);
4997 	}
4998 }
4999 
5000 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
5001 
5002 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
5003 {
5004 	if (xdp_prog) {
5005 		struct xdp_buff xdp;
5006 		u32 act;
5007 		int err;
5008 
5009 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
5010 		if (act != XDP_PASS) {
5011 			switch (act) {
5012 			case XDP_REDIRECT:
5013 				err = xdp_do_generic_redirect(skb->dev, skb,
5014 							      &xdp, xdp_prog);
5015 				if (err)
5016 					goto out_redir;
5017 				break;
5018 			case XDP_TX:
5019 				generic_xdp_tx(skb, xdp_prog);
5020 				break;
5021 			}
5022 			return XDP_DROP;
5023 		}
5024 	}
5025 	return XDP_PASS;
5026 out_redir:
5027 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
5028 	return XDP_DROP;
5029 }
5030 EXPORT_SYMBOL_GPL(do_xdp_generic);
5031 
5032 static int netif_rx_internal(struct sk_buff *skb)
5033 {
5034 	int ret;
5035 
5036 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5037 
5038 	trace_netif_rx(skb);
5039 
5040 #ifdef CONFIG_RPS
5041 	if (static_branch_unlikely(&rps_needed)) {
5042 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5043 		int cpu;
5044 
5045 		rcu_read_lock();
5046 
5047 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
5048 		if (cpu < 0)
5049 			cpu = smp_processor_id();
5050 
5051 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5052 
5053 		rcu_read_unlock();
5054 	} else
5055 #endif
5056 	{
5057 		unsigned int qtail;
5058 
5059 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
5060 	}
5061 	return ret;
5062 }
5063 
5064 /**
5065  *	__netif_rx	-	Slightly optimized version of netif_rx
5066  *	@skb: buffer to post
5067  *
5068  *	This behaves as netif_rx except that it does not disable bottom halves.
5069  *	As a result this function may only be invoked from the interrupt context
5070  *	(either hard or soft interrupt).
5071  */
5072 int __netif_rx(struct sk_buff *skb)
5073 {
5074 	int ret;
5075 
5076 	lockdep_assert_once(hardirq_count() | softirq_count());
5077 
5078 	trace_netif_rx_entry(skb);
5079 	ret = netif_rx_internal(skb);
5080 	trace_netif_rx_exit(ret);
5081 	return ret;
5082 }
5083 EXPORT_SYMBOL(__netif_rx);
5084 
5085 /**
5086  *	netif_rx	-	post buffer to the network code
5087  *	@skb: buffer to post
5088  *
5089  *	This function receives a packet from a device driver and queues it for
5090  *	the upper (protocol) levels to process via the backlog NAPI device. It
5091  *	always succeeds. The buffer may be dropped during processing for
5092  *	congestion control or by the protocol layers.
5093  *	The network buffer is passed via the backlog NAPI device. Modern NIC
5094  *	driver should use NAPI and GRO.
5095  *	This function can used from interrupt and from process context. The
5096  *	caller from process context must not disable interrupts before invoking
5097  *	this function.
5098  *
5099  *	return values:
5100  *	NET_RX_SUCCESS	(no congestion)
5101  *	NET_RX_DROP     (packet was dropped)
5102  *
5103  */
5104 int netif_rx(struct sk_buff *skb)
5105 {
5106 	bool need_bh_off = !(hardirq_count() | softirq_count());
5107 	int ret;
5108 
5109 	if (need_bh_off)
5110 		local_bh_disable();
5111 	trace_netif_rx_entry(skb);
5112 	ret = netif_rx_internal(skb);
5113 	trace_netif_rx_exit(ret);
5114 	if (need_bh_off)
5115 		local_bh_enable();
5116 	return ret;
5117 }
5118 EXPORT_SYMBOL(netif_rx);
5119 
5120 static __latent_entropy void net_tx_action(struct softirq_action *h)
5121 {
5122 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5123 
5124 	if (sd->completion_queue) {
5125 		struct sk_buff *clist;
5126 
5127 		local_irq_disable();
5128 		clist = sd->completion_queue;
5129 		sd->completion_queue = NULL;
5130 		local_irq_enable();
5131 
5132 		while (clist) {
5133 			struct sk_buff *skb = clist;
5134 
5135 			clist = clist->next;
5136 
5137 			WARN_ON(refcount_read(&skb->users));
5138 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5139 				trace_consume_skb(skb, net_tx_action);
5140 			else
5141 				trace_kfree_skb(skb, net_tx_action,
5142 						get_kfree_skb_cb(skb)->reason);
5143 
5144 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5145 				__kfree_skb(skb);
5146 			else
5147 				__napi_kfree_skb(skb,
5148 						 get_kfree_skb_cb(skb)->reason);
5149 		}
5150 	}
5151 
5152 	if (sd->output_queue) {
5153 		struct Qdisc *head;
5154 
5155 		local_irq_disable();
5156 		head = sd->output_queue;
5157 		sd->output_queue = NULL;
5158 		sd->output_queue_tailp = &sd->output_queue;
5159 		local_irq_enable();
5160 
5161 		rcu_read_lock();
5162 
5163 		while (head) {
5164 			struct Qdisc *q = head;
5165 			spinlock_t *root_lock = NULL;
5166 
5167 			head = head->next_sched;
5168 
5169 			/* We need to make sure head->next_sched is read
5170 			 * before clearing __QDISC_STATE_SCHED
5171 			 */
5172 			smp_mb__before_atomic();
5173 
5174 			if (!(q->flags & TCQ_F_NOLOCK)) {
5175 				root_lock = qdisc_lock(q);
5176 				spin_lock(root_lock);
5177 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5178 						     &q->state))) {
5179 				/* There is a synchronize_net() between
5180 				 * STATE_DEACTIVATED flag being set and
5181 				 * qdisc_reset()/some_qdisc_is_busy() in
5182 				 * dev_deactivate(), so we can safely bail out
5183 				 * early here to avoid data race between
5184 				 * qdisc_deactivate() and some_qdisc_is_busy()
5185 				 * for lockless qdisc.
5186 				 */
5187 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5188 				continue;
5189 			}
5190 
5191 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5192 			qdisc_run(q);
5193 			if (root_lock)
5194 				spin_unlock(root_lock);
5195 		}
5196 
5197 		rcu_read_unlock();
5198 	}
5199 
5200 	xfrm_dev_backlog(sd);
5201 }
5202 
5203 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5204 /* This hook is defined here for ATM LANE */
5205 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5206 			     unsigned char *addr) __read_mostly;
5207 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5208 #endif
5209 
5210 /**
5211  *	netdev_is_rx_handler_busy - check if receive handler is registered
5212  *	@dev: device to check
5213  *
5214  *	Check if a receive handler is already registered for a given device.
5215  *	Return true if there one.
5216  *
5217  *	The caller must hold the rtnl_mutex.
5218  */
5219 bool netdev_is_rx_handler_busy(struct net_device *dev)
5220 {
5221 	ASSERT_RTNL();
5222 	return dev && rtnl_dereference(dev->rx_handler);
5223 }
5224 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5225 
5226 /**
5227  *	netdev_rx_handler_register - register receive handler
5228  *	@dev: device to register a handler for
5229  *	@rx_handler: receive handler to register
5230  *	@rx_handler_data: data pointer that is used by rx handler
5231  *
5232  *	Register a receive handler for a device. This handler will then be
5233  *	called from __netif_receive_skb. A negative errno code is returned
5234  *	on a failure.
5235  *
5236  *	The caller must hold the rtnl_mutex.
5237  *
5238  *	For a general description of rx_handler, see enum rx_handler_result.
5239  */
5240 int netdev_rx_handler_register(struct net_device *dev,
5241 			       rx_handler_func_t *rx_handler,
5242 			       void *rx_handler_data)
5243 {
5244 	if (netdev_is_rx_handler_busy(dev))
5245 		return -EBUSY;
5246 
5247 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5248 		return -EINVAL;
5249 
5250 	/* Note: rx_handler_data must be set before rx_handler */
5251 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5252 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5253 
5254 	return 0;
5255 }
5256 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5257 
5258 /**
5259  *	netdev_rx_handler_unregister - unregister receive handler
5260  *	@dev: device to unregister a handler from
5261  *
5262  *	Unregister a receive handler from a device.
5263  *
5264  *	The caller must hold the rtnl_mutex.
5265  */
5266 void netdev_rx_handler_unregister(struct net_device *dev)
5267 {
5268 
5269 	ASSERT_RTNL();
5270 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5271 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5272 	 * section has a guarantee to see a non NULL rx_handler_data
5273 	 * as well.
5274 	 */
5275 	synchronize_net();
5276 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5277 }
5278 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5279 
5280 /*
5281  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5282  * the special handling of PFMEMALLOC skbs.
5283  */
5284 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5285 {
5286 	switch (skb->protocol) {
5287 	case htons(ETH_P_ARP):
5288 	case htons(ETH_P_IP):
5289 	case htons(ETH_P_IPV6):
5290 	case htons(ETH_P_8021Q):
5291 	case htons(ETH_P_8021AD):
5292 		return true;
5293 	default:
5294 		return false;
5295 	}
5296 }
5297 
5298 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5299 			     int *ret, struct net_device *orig_dev)
5300 {
5301 	if (nf_hook_ingress_active(skb)) {
5302 		int ingress_retval;
5303 
5304 		if (*pt_prev) {
5305 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5306 			*pt_prev = NULL;
5307 		}
5308 
5309 		rcu_read_lock();
5310 		ingress_retval = nf_hook_ingress(skb);
5311 		rcu_read_unlock();
5312 		return ingress_retval;
5313 	}
5314 	return 0;
5315 }
5316 
5317 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5318 				    struct packet_type **ppt_prev)
5319 {
5320 	struct packet_type *ptype, *pt_prev;
5321 	rx_handler_func_t *rx_handler;
5322 	struct sk_buff *skb = *pskb;
5323 	struct net_device *orig_dev;
5324 	bool deliver_exact = false;
5325 	int ret = NET_RX_DROP;
5326 	__be16 type;
5327 
5328 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5329 
5330 	trace_netif_receive_skb(skb);
5331 
5332 	orig_dev = skb->dev;
5333 
5334 	skb_reset_network_header(skb);
5335 	if (!skb_transport_header_was_set(skb))
5336 		skb_reset_transport_header(skb);
5337 	skb_reset_mac_len(skb);
5338 
5339 	pt_prev = NULL;
5340 
5341 another_round:
5342 	skb->skb_iif = skb->dev->ifindex;
5343 
5344 	__this_cpu_inc(softnet_data.processed);
5345 
5346 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5347 		int ret2;
5348 
5349 		migrate_disable();
5350 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5351 		migrate_enable();
5352 
5353 		if (ret2 != XDP_PASS) {
5354 			ret = NET_RX_DROP;
5355 			goto out;
5356 		}
5357 	}
5358 
5359 	if (eth_type_vlan(skb->protocol)) {
5360 		skb = skb_vlan_untag(skb);
5361 		if (unlikely(!skb))
5362 			goto out;
5363 	}
5364 
5365 	if (skb_skip_tc_classify(skb))
5366 		goto skip_classify;
5367 
5368 	if (pfmemalloc)
5369 		goto skip_taps;
5370 
5371 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5372 		if (pt_prev)
5373 			ret = deliver_skb(skb, pt_prev, orig_dev);
5374 		pt_prev = ptype;
5375 	}
5376 
5377 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5378 		if (pt_prev)
5379 			ret = deliver_skb(skb, pt_prev, orig_dev);
5380 		pt_prev = ptype;
5381 	}
5382 
5383 skip_taps:
5384 #ifdef CONFIG_NET_INGRESS
5385 	if (static_branch_unlikely(&ingress_needed_key)) {
5386 		bool another = false;
5387 
5388 		nf_skip_egress(skb, true);
5389 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5390 					 &another);
5391 		if (another)
5392 			goto another_round;
5393 		if (!skb)
5394 			goto out;
5395 
5396 		nf_skip_egress(skb, false);
5397 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5398 			goto out;
5399 	}
5400 #endif
5401 	skb_reset_redirect(skb);
5402 skip_classify:
5403 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5404 		goto drop;
5405 
5406 	if (skb_vlan_tag_present(skb)) {
5407 		if (pt_prev) {
5408 			ret = deliver_skb(skb, pt_prev, orig_dev);
5409 			pt_prev = NULL;
5410 		}
5411 		if (vlan_do_receive(&skb))
5412 			goto another_round;
5413 		else if (unlikely(!skb))
5414 			goto out;
5415 	}
5416 
5417 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5418 	if (rx_handler) {
5419 		if (pt_prev) {
5420 			ret = deliver_skb(skb, pt_prev, orig_dev);
5421 			pt_prev = NULL;
5422 		}
5423 		switch (rx_handler(&skb)) {
5424 		case RX_HANDLER_CONSUMED:
5425 			ret = NET_RX_SUCCESS;
5426 			goto out;
5427 		case RX_HANDLER_ANOTHER:
5428 			goto another_round;
5429 		case RX_HANDLER_EXACT:
5430 			deliver_exact = true;
5431 			break;
5432 		case RX_HANDLER_PASS:
5433 			break;
5434 		default:
5435 			BUG();
5436 		}
5437 	}
5438 
5439 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5440 check_vlan_id:
5441 		if (skb_vlan_tag_get_id(skb)) {
5442 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5443 			 * find vlan device.
5444 			 */
5445 			skb->pkt_type = PACKET_OTHERHOST;
5446 		} else if (eth_type_vlan(skb->protocol)) {
5447 			/* Outer header is 802.1P with vlan 0, inner header is
5448 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5449 			 * not find vlan dev for vlan id 0.
5450 			 */
5451 			__vlan_hwaccel_clear_tag(skb);
5452 			skb = skb_vlan_untag(skb);
5453 			if (unlikely(!skb))
5454 				goto out;
5455 			if (vlan_do_receive(&skb))
5456 				/* After stripping off 802.1P header with vlan 0
5457 				 * vlan dev is found for inner header.
5458 				 */
5459 				goto another_round;
5460 			else if (unlikely(!skb))
5461 				goto out;
5462 			else
5463 				/* We have stripped outer 802.1P vlan 0 header.
5464 				 * But could not find vlan dev.
5465 				 * check again for vlan id to set OTHERHOST.
5466 				 */
5467 				goto check_vlan_id;
5468 		}
5469 		/* Note: we might in the future use prio bits
5470 		 * and set skb->priority like in vlan_do_receive()
5471 		 * For the time being, just ignore Priority Code Point
5472 		 */
5473 		__vlan_hwaccel_clear_tag(skb);
5474 	}
5475 
5476 	type = skb->protocol;
5477 
5478 	/* deliver only exact match when indicated */
5479 	if (likely(!deliver_exact)) {
5480 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5481 				       &ptype_base[ntohs(type) &
5482 						   PTYPE_HASH_MASK]);
5483 	}
5484 
5485 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5486 			       &orig_dev->ptype_specific);
5487 
5488 	if (unlikely(skb->dev != orig_dev)) {
5489 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5490 				       &skb->dev->ptype_specific);
5491 	}
5492 
5493 	if (pt_prev) {
5494 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5495 			goto drop;
5496 		*ppt_prev = pt_prev;
5497 	} else {
5498 drop:
5499 		if (!deliver_exact)
5500 			dev_core_stats_rx_dropped_inc(skb->dev);
5501 		else
5502 			dev_core_stats_rx_nohandler_inc(skb->dev);
5503 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5504 		/* Jamal, now you will not able to escape explaining
5505 		 * me how you were going to use this. :-)
5506 		 */
5507 		ret = NET_RX_DROP;
5508 	}
5509 
5510 out:
5511 	/* The invariant here is that if *ppt_prev is not NULL
5512 	 * then skb should also be non-NULL.
5513 	 *
5514 	 * Apparently *ppt_prev assignment above holds this invariant due to
5515 	 * skb dereferencing near it.
5516 	 */
5517 	*pskb = skb;
5518 	return ret;
5519 }
5520 
5521 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5522 {
5523 	struct net_device *orig_dev = skb->dev;
5524 	struct packet_type *pt_prev = NULL;
5525 	int ret;
5526 
5527 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5528 	if (pt_prev)
5529 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5530 					 skb->dev, pt_prev, orig_dev);
5531 	return ret;
5532 }
5533 
5534 /**
5535  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5536  *	@skb: buffer to process
5537  *
5538  *	More direct receive version of netif_receive_skb().  It should
5539  *	only be used by callers that have a need to skip RPS and Generic XDP.
5540  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5541  *
5542  *	This function may only be called from softirq context and interrupts
5543  *	should be enabled.
5544  *
5545  *	Return values (usually ignored):
5546  *	NET_RX_SUCCESS: no congestion
5547  *	NET_RX_DROP: packet was dropped
5548  */
5549 int netif_receive_skb_core(struct sk_buff *skb)
5550 {
5551 	int ret;
5552 
5553 	rcu_read_lock();
5554 	ret = __netif_receive_skb_one_core(skb, false);
5555 	rcu_read_unlock();
5556 
5557 	return ret;
5558 }
5559 EXPORT_SYMBOL(netif_receive_skb_core);
5560 
5561 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5562 						  struct packet_type *pt_prev,
5563 						  struct net_device *orig_dev)
5564 {
5565 	struct sk_buff *skb, *next;
5566 
5567 	if (!pt_prev)
5568 		return;
5569 	if (list_empty(head))
5570 		return;
5571 	if (pt_prev->list_func != NULL)
5572 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5573 				   ip_list_rcv, head, pt_prev, orig_dev);
5574 	else
5575 		list_for_each_entry_safe(skb, next, head, list) {
5576 			skb_list_del_init(skb);
5577 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5578 		}
5579 }
5580 
5581 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5582 {
5583 	/* Fast-path assumptions:
5584 	 * - There is no RX handler.
5585 	 * - Only one packet_type matches.
5586 	 * If either of these fails, we will end up doing some per-packet
5587 	 * processing in-line, then handling the 'last ptype' for the whole
5588 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5589 	 * because the 'last ptype' must be constant across the sublist, and all
5590 	 * other ptypes are handled per-packet.
5591 	 */
5592 	/* Current (common) ptype of sublist */
5593 	struct packet_type *pt_curr = NULL;
5594 	/* Current (common) orig_dev of sublist */
5595 	struct net_device *od_curr = NULL;
5596 	struct list_head sublist;
5597 	struct sk_buff *skb, *next;
5598 
5599 	INIT_LIST_HEAD(&sublist);
5600 	list_for_each_entry_safe(skb, next, head, list) {
5601 		struct net_device *orig_dev = skb->dev;
5602 		struct packet_type *pt_prev = NULL;
5603 
5604 		skb_list_del_init(skb);
5605 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5606 		if (!pt_prev)
5607 			continue;
5608 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5609 			/* dispatch old sublist */
5610 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5611 			/* start new sublist */
5612 			INIT_LIST_HEAD(&sublist);
5613 			pt_curr = pt_prev;
5614 			od_curr = orig_dev;
5615 		}
5616 		list_add_tail(&skb->list, &sublist);
5617 	}
5618 
5619 	/* dispatch final sublist */
5620 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5621 }
5622 
5623 static int __netif_receive_skb(struct sk_buff *skb)
5624 {
5625 	int ret;
5626 
5627 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5628 		unsigned int noreclaim_flag;
5629 
5630 		/*
5631 		 * PFMEMALLOC skbs are special, they should
5632 		 * - be delivered to SOCK_MEMALLOC sockets only
5633 		 * - stay away from userspace
5634 		 * - have bounded memory usage
5635 		 *
5636 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5637 		 * context down to all allocation sites.
5638 		 */
5639 		noreclaim_flag = memalloc_noreclaim_save();
5640 		ret = __netif_receive_skb_one_core(skb, true);
5641 		memalloc_noreclaim_restore(noreclaim_flag);
5642 	} else
5643 		ret = __netif_receive_skb_one_core(skb, false);
5644 
5645 	return ret;
5646 }
5647 
5648 static void __netif_receive_skb_list(struct list_head *head)
5649 {
5650 	unsigned long noreclaim_flag = 0;
5651 	struct sk_buff *skb, *next;
5652 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5653 
5654 	list_for_each_entry_safe(skb, next, head, list) {
5655 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5656 			struct list_head sublist;
5657 
5658 			/* Handle the previous sublist */
5659 			list_cut_before(&sublist, head, &skb->list);
5660 			if (!list_empty(&sublist))
5661 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5662 			pfmemalloc = !pfmemalloc;
5663 			/* See comments in __netif_receive_skb */
5664 			if (pfmemalloc)
5665 				noreclaim_flag = memalloc_noreclaim_save();
5666 			else
5667 				memalloc_noreclaim_restore(noreclaim_flag);
5668 		}
5669 	}
5670 	/* Handle the remaining sublist */
5671 	if (!list_empty(head))
5672 		__netif_receive_skb_list_core(head, pfmemalloc);
5673 	/* Restore pflags */
5674 	if (pfmemalloc)
5675 		memalloc_noreclaim_restore(noreclaim_flag);
5676 }
5677 
5678 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5679 {
5680 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5681 	struct bpf_prog *new = xdp->prog;
5682 	int ret = 0;
5683 
5684 	switch (xdp->command) {
5685 	case XDP_SETUP_PROG:
5686 		rcu_assign_pointer(dev->xdp_prog, new);
5687 		if (old)
5688 			bpf_prog_put(old);
5689 
5690 		if (old && !new) {
5691 			static_branch_dec(&generic_xdp_needed_key);
5692 		} else if (new && !old) {
5693 			static_branch_inc(&generic_xdp_needed_key);
5694 			dev_disable_lro(dev);
5695 			dev_disable_gro_hw(dev);
5696 		}
5697 		break;
5698 
5699 	default:
5700 		ret = -EINVAL;
5701 		break;
5702 	}
5703 
5704 	return ret;
5705 }
5706 
5707 static int netif_receive_skb_internal(struct sk_buff *skb)
5708 {
5709 	int ret;
5710 
5711 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5712 
5713 	if (skb_defer_rx_timestamp(skb))
5714 		return NET_RX_SUCCESS;
5715 
5716 	rcu_read_lock();
5717 #ifdef CONFIG_RPS
5718 	if (static_branch_unlikely(&rps_needed)) {
5719 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5720 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5721 
5722 		if (cpu >= 0) {
5723 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5724 			rcu_read_unlock();
5725 			return ret;
5726 		}
5727 	}
5728 #endif
5729 	ret = __netif_receive_skb(skb);
5730 	rcu_read_unlock();
5731 	return ret;
5732 }
5733 
5734 void netif_receive_skb_list_internal(struct list_head *head)
5735 {
5736 	struct sk_buff *skb, *next;
5737 	struct list_head sublist;
5738 
5739 	INIT_LIST_HEAD(&sublist);
5740 	list_for_each_entry_safe(skb, next, head, list) {
5741 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5742 		skb_list_del_init(skb);
5743 		if (!skb_defer_rx_timestamp(skb))
5744 			list_add_tail(&skb->list, &sublist);
5745 	}
5746 	list_splice_init(&sublist, head);
5747 
5748 	rcu_read_lock();
5749 #ifdef CONFIG_RPS
5750 	if (static_branch_unlikely(&rps_needed)) {
5751 		list_for_each_entry_safe(skb, next, head, list) {
5752 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5753 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5754 
5755 			if (cpu >= 0) {
5756 				/* Will be handled, remove from list */
5757 				skb_list_del_init(skb);
5758 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5759 			}
5760 		}
5761 	}
5762 #endif
5763 	__netif_receive_skb_list(head);
5764 	rcu_read_unlock();
5765 }
5766 
5767 /**
5768  *	netif_receive_skb - process receive buffer from network
5769  *	@skb: buffer to process
5770  *
5771  *	netif_receive_skb() is the main receive data processing function.
5772  *	It always succeeds. The buffer may be dropped during processing
5773  *	for congestion control or by the protocol layers.
5774  *
5775  *	This function may only be called from softirq context and interrupts
5776  *	should be enabled.
5777  *
5778  *	Return values (usually ignored):
5779  *	NET_RX_SUCCESS: no congestion
5780  *	NET_RX_DROP: packet was dropped
5781  */
5782 int netif_receive_skb(struct sk_buff *skb)
5783 {
5784 	int ret;
5785 
5786 	trace_netif_receive_skb_entry(skb);
5787 
5788 	ret = netif_receive_skb_internal(skb);
5789 	trace_netif_receive_skb_exit(ret);
5790 
5791 	return ret;
5792 }
5793 EXPORT_SYMBOL(netif_receive_skb);
5794 
5795 /**
5796  *	netif_receive_skb_list - process many receive buffers from network
5797  *	@head: list of skbs to process.
5798  *
5799  *	Since return value of netif_receive_skb() is normally ignored, and
5800  *	wouldn't be meaningful for a list, this function returns void.
5801  *
5802  *	This function may only be called from softirq context and interrupts
5803  *	should be enabled.
5804  */
5805 void netif_receive_skb_list(struct list_head *head)
5806 {
5807 	struct sk_buff *skb;
5808 
5809 	if (list_empty(head))
5810 		return;
5811 	if (trace_netif_receive_skb_list_entry_enabled()) {
5812 		list_for_each_entry(skb, head, list)
5813 			trace_netif_receive_skb_list_entry(skb);
5814 	}
5815 	netif_receive_skb_list_internal(head);
5816 	trace_netif_receive_skb_list_exit(0);
5817 }
5818 EXPORT_SYMBOL(netif_receive_skb_list);
5819 
5820 static DEFINE_PER_CPU(struct work_struct, flush_works);
5821 
5822 /* Network device is going away, flush any packets still pending */
5823 static void flush_backlog(struct work_struct *work)
5824 {
5825 	struct sk_buff *skb, *tmp;
5826 	struct softnet_data *sd;
5827 
5828 	local_bh_disable();
5829 	sd = this_cpu_ptr(&softnet_data);
5830 
5831 	rps_lock_irq_disable(sd);
5832 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5833 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5834 			__skb_unlink(skb, &sd->input_pkt_queue);
5835 			dev_kfree_skb_irq(skb);
5836 			input_queue_head_incr(sd);
5837 		}
5838 	}
5839 	rps_unlock_irq_enable(sd);
5840 
5841 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5842 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5843 			__skb_unlink(skb, &sd->process_queue);
5844 			kfree_skb(skb);
5845 			input_queue_head_incr(sd);
5846 		}
5847 	}
5848 	local_bh_enable();
5849 }
5850 
5851 static bool flush_required(int cpu)
5852 {
5853 #if IS_ENABLED(CONFIG_RPS)
5854 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5855 	bool do_flush;
5856 
5857 	rps_lock_irq_disable(sd);
5858 
5859 	/* as insertion into process_queue happens with the rps lock held,
5860 	 * process_queue access may race only with dequeue
5861 	 */
5862 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5863 		   !skb_queue_empty_lockless(&sd->process_queue);
5864 	rps_unlock_irq_enable(sd);
5865 
5866 	return do_flush;
5867 #endif
5868 	/* without RPS we can't safely check input_pkt_queue: during a
5869 	 * concurrent remote skb_queue_splice() we can detect as empty both
5870 	 * input_pkt_queue and process_queue even if the latter could end-up
5871 	 * containing a lot of packets.
5872 	 */
5873 	return true;
5874 }
5875 
5876 static void flush_all_backlogs(void)
5877 {
5878 	static cpumask_t flush_cpus;
5879 	unsigned int cpu;
5880 
5881 	/* since we are under rtnl lock protection we can use static data
5882 	 * for the cpumask and avoid allocating on stack the possibly
5883 	 * large mask
5884 	 */
5885 	ASSERT_RTNL();
5886 
5887 	cpus_read_lock();
5888 
5889 	cpumask_clear(&flush_cpus);
5890 	for_each_online_cpu(cpu) {
5891 		if (flush_required(cpu)) {
5892 			queue_work_on(cpu, system_highpri_wq,
5893 				      per_cpu_ptr(&flush_works, cpu));
5894 			cpumask_set_cpu(cpu, &flush_cpus);
5895 		}
5896 	}
5897 
5898 	/* we can have in flight packet[s] on the cpus we are not flushing,
5899 	 * synchronize_net() in unregister_netdevice_many() will take care of
5900 	 * them
5901 	 */
5902 	for_each_cpu(cpu, &flush_cpus)
5903 		flush_work(per_cpu_ptr(&flush_works, cpu));
5904 
5905 	cpus_read_unlock();
5906 }
5907 
5908 static void net_rps_send_ipi(struct softnet_data *remsd)
5909 {
5910 #ifdef CONFIG_RPS
5911 	while (remsd) {
5912 		struct softnet_data *next = remsd->rps_ipi_next;
5913 
5914 		if (cpu_online(remsd->cpu))
5915 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5916 		remsd = next;
5917 	}
5918 #endif
5919 }
5920 
5921 /*
5922  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5923  * Note: called with local irq disabled, but exits with local irq enabled.
5924  */
5925 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5926 {
5927 #ifdef CONFIG_RPS
5928 	struct softnet_data *remsd = sd->rps_ipi_list;
5929 
5930 	if (remsd) {
5931 		sd->rps_ipi_list = NULL;
5932 
5933 		local_irq_enable();
5934 
5935 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5936 		net_rps_send_ipi(remsd);
5937 	} else
5938 #endif
5939 		local_irq_enable();
5940 }
5941 
5942 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5943 {
5944 #ifdef CONFIG_RPS
5945 	return sd->rps_ipi_list != NULL;
5946 #else
5947 	return false;
5948 #endif
5949 }
5950 
5951 static int process_backlog(struct napi_struct *napi, int quota)
5952 {
5953 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5954 	bool again = true;
5955 	int work = 0;
5956 
5957 	/* Check if we have pending ipi, its better to send them now,
5958 	 * not waiting net_rx_action() end.
5959 	 */
5960 	if (sd_has_rps_ipi_waiting(sd)) {
5961 		local_irq_disable();
5962 		net_rps_action_and_irq_enable(sd);
5963 	}
5964 
5965 	napi->weight = READ_ONCE(dev_rx_weight);
5966 	while (again) {
5967 		struct sk_buff *skb;
5968 
5969 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5970 			rcu_read_lock();
5971 			__netif_receive_skb(skb);
5972 			rcu_read_unlock();
5973 			input_queue_head_incr(sd);
5974 			if (++work >= quota)
5975 				return work;
5976 
5977 		}
5978 
5979 		rps_lock_irq_disable(sd);
5980 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5981 			/*
5982 			 * Inline a custom version of __napi_complete().
5983 			 * only current cpu owns and manipulates this napi,
5984 			 * and NAPI_STATE_SCHED is the only possible flag set
5985 			 * on backlog.
5986 			 * We can use a plain write instead of clear_bit(),
5987 			 * and we dont need an smp_mb() memory barrier.
5988 			 */
5989 			napi->state = 0;
5990 			again = false;
5991 		} else {
5992 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5993 						   &sd->process_queue);
5994 		}
5995 		rps_unlock_irq_enable(sd);
5996 	}
5997 
5998 	return work;
5999 }
6000 
6001 /**
6002  * __napi_schedule - schedule for receive
6003  * @n: entry to schedule
6004  *
6005  * The entry's receive function will be scheduled to run.
6006  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
6007  */
6008 void __napi_schedule(struct napi_struct *n)
6009 {
6010 	unsigned long flags;
6011 
6012 	local_irq_save(flags);
6013 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
6014 	local_irq_restore(flags);
6015 }
6016 EXPORT_SYMBOL(__napi_schedule);
6017 
6018 /**
6019  *	napi_schedule_prep - check if napi can be scheduled
6020  *	@n: napi context
6021  *
6022  * Test if NAPI routine is already running, and if not mark
6023  * it as running.  This is used as a condition variable to
6024  * insure only one NAPI poll instance runs.  We also make
6025  * sure there is no pending NAPI disable.
6026  */
6027 bool napi_schedule_prep(struct napi_struct *n)
6028 {
6029 	unsigned long new, val = READ_ONCE(n->state);
6030 
6031 	do {
6032 		if (unlikely(val & NAPIF_STATE_DISABLE))
6033 			return false;
6034 		new = val | NAPIF_STATE_SCHED;
6035 
6036 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
6037 		 * This was suggested by Alexander Duyck, as compiler
6038 		 * emits better code than :
6039 		 * if (val & NAPIF_STATE_SCHED)
6040 		 *     new |= NAPIF_STATE_MISSED;
6041 		 */
6042 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6043 						   NAPIF_STATE_MISSED;
6044 	} while (!try_cmpxchg(&n->state, &val, new));
6045 
6046 	return !(val & NAPIF_STATE_SCHED);
6047 }
6048 EXPORT_SYMBOL(napi_schedule_prep);
6049 
6050 /**
6051  * __napi_schedule_irqoff - schedule for receive
6052  * @n: entry to schedule
6053  *
6054  * Variant of __napi_schedule() assuming hard irqs are masked.
6055  *
6056  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6057  * because the interrupt disabled assumption might not be true
6058  * due to force-threaded interrupts and spinlock substitution.
6059  */
6060 void __napi_schedule_irqoff(struct napi_struct *n)
6061 {
6062 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6063 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6064 	else
6065 		__napi_schedule(n);
6066 }
6067 EXPORT_SYMBOL(__napi_schedule_irqoff);
6068 
6069 bool napi_complete_done(struct napi_struct *n, int work_done)
6070 {
6071 	unsigned long flags, val, new, timeout = 0;
6072 	bool ret = true;
6073 
6074 	/*
6075 	 * 1) Don't let napi dequeue from the cpu poll list
6076 	 *    just in case its running on a different cpu.
6077 	 * 2) If we are busy polling, do nothing here, we have
6078 	 *    the guarantee we will be called later.
6079 	 */
6080 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6081 				 NAPIF_STATE_IN_BUSY_POLL)))
6082 		return false;
6083 
6084 	if (work_done) {
6085 		if (n->gro_bitmask)
6086 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6087 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6088 	}
6089 	if (n->defer_hard_irqs_count > 0) {
6090 		n->defer_hard_irqs_count--;
6091 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6092 		if (timeout)
6093 			ret = false;
6094 	}
6095 	if (n->gro_bitmask) {
6096 		/* When the NAPI instance uses a timeout and keeps postponing
6097 		 * it, we need to bound somehow the time packets are kept in
6098 		 * the GRO layer
6099 		 */
6100 		napi_gro_flush(n, !!timeout);
6101 	}
6102 
6103 	gro_normal_list(n);
6104 
6105 	if (unlikely(!list_empty(&n->poll_list))) {
6106 		/* If n->poll_list is not empty, we need to mask irqs */
6107 		local_irq_save(flags);
6108 		list_del_init(&n->poll_list);
6109 		local_irq_restore(flags);
6110 	}
6111 	WRITE_ONCE(n->list_owner, -1);
6112 
6113 	val = READ_ONCE(n->state);
6114 	do {
6115 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6116 
6117 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6118 			      NAPIF_STATE_SCHED_THREADED |
6119 			      NAPIF_STATE_PREFER_BUSY_POLL);
6120 
6121 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6122 		 * because we will call napi->poll() one more time.
6123 		 * This C code was suggested by Alexander Duyck to help gcc.
6124 		 */
6125 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6126 						    NAPIF_STATE_SCHED;
6127 	} while (!try_cmpxchg(&n->state, &val, new));
6128 
6129 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6130 		__napi_schedule(n);
6131 		return false;
6132 	}
6133 
6134 	if (timeout)
6135 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6136 			      HRTIMER_MODE_REL_PINNED);
6137 	return ret;
6138 }
6139 EXPORT_SYMBOL(napi_complete_done);
6140 
6141 /* must be called under rcu_read_lock(), as we dont take a reference */
6142 static struct napi_struct *napi_by_id(unsigned int napi_id)
6143 {
6144 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6145 	struct napi_struct *napi;
6146 
6147 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6148 		if (napi->napi_id == napi_id)
6149 			return napi;
6150 
6151 	return NULL;
6152 }
6153 
6154 #if defined(CONFIG_NET_RX_BUSY_POLL)
6155 
6156 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6157 {
6158 	if (!skip_schedule) {
6159 		gro_normal_list(napi);
6160 		__napi_schedule(napi);
6161 		return;
6162 	}
6163 
6164 	if (napi->gro_bitmask) {
6165 		/* flush too old packets
6166 		 * If HZ < 1000, flush all packets.
6167 		 */
6168 		napi_gro_flush(napi, HZ >= 1000);
6169 	}
6170 
6171 	gro_normal_list(napi);
6172 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6173 }
6174 
6175 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6176 			   u16 budget)
6177 {
6178 	bool skip_schedule = false;
6179 	unsigned long timeout;
6180 	int rc;
6181 
6182 	/* Busy polling means there is a high chance device driver hard irq
6183 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6184 	 * set in napi_schedule_prep().
6185 	 * Since we are about to call napi->poll() once more, we can safely
6186 	 * clear NAPI_STATE_MISSED.
6187 	 *
6188 	 * Note: x86 could use a single "lock and ..." instruction
6189 	 * to perform these two clear_bit()
6190 	 */
6191 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6192 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6193 
6194 	local_bh_disable();
6195 
6196 	if (prefer_busy_poll) {
6197 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6198 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6199 		if (napi->defer_hard_irqs_count && timeout) {
6200 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6201 			skip_schedule = true;
6202 		}
6203 	}
6204 
6205 	/* All we really want here is to re-enable device interrupts.
6206 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6207 	 */
6208 	rc = napi->poll(napi, budget);
6209 	/* We can't gro_normal_list() here, because napi->poll() might have
6210 	 * rearmed the napi (napi_complete_done()) in which case it could
6211 	 * already be running on another CPU.
6212 	 */
6213 	trace_napi_poll(napi, rc, budget);
6214 	netpoll_poll_unlock(have_poll_lock);
6215 	if (rc == budget)
6216 		__busy_poll_stop(napi, skip_schedule);
6217 	local_bh_enable();
6218 }
6219 
6220 void napi_busy_loop(unsigned int napi_id,
6221 		    bool (*loop_end)(void *, unsigned long),
6222 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6223 {
6224 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6225 	int (*napi_poll)(struct napi_struct *napi, int budget);
6226 	void *have_poll_lock = NULL;
6227 	struct napi_struct *napi;
6228 
6229 restart:
6230 	napi_poll = NULL;
6231 
6232 	rcu_read_lock();
6233 
6234 	napi = napi_by_id(napi_id);
6235 	if (!napi)
6236 		goto out;
6237 
6238 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6239 		preempt_disable();
6240 	for (;;) {
6241 		int work = 0;
6242 
6243 		local_bh_disable();
6244 		if (!napi_poll) {
6245 			unsigned long val = READ_ONCE(napi->state);
6246 
6247 			/* If multiple threads are competing for this napi,
6248 			 * we avoid dirtying napi->state as much as we can.
6249 			 */
6250 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6251 				   NAPIF_STATE_IN_BUSY_POLL)) {
6252 				if (prefer_busy_poll)
6253 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6254 				goto count;
6255 			}
6256 			if (cmpxchg(&napi->state, val,
6257 				    val | NAPIF_STATE_IN_BUSY_POLL |
6258 					  NAPIF_STATE_SCHED) != val) {
6259 				if (prefer_busy_poll)
6260 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6261 				goto count;
6262 			}
6263 			have_poll_lock = netpoll_poll_lock(napi);
6264 			napi_poll = napi->poll;
6265 		}
6266 		work = napi_poll(napi, budget);
6267 		trace_napi_poll(napi, work, budget);
6268 		gro_normal_list(napi);
6269 count:
6270 		if (work > 0)
6271 			__NET_ADD_STATS(dev_net(napi->dev),
6272 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6273 		local_bh_enable();
6274 
6275 		if (!loop_end || loop_end(loop_end_arg, start_time))
6276 			break;
6277 
6278 		if (unlikely(need_resched())) {
6279 			if (napi_poll)
6280 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6281 			if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6282 				preempt_enable();
6283 			rcu_read_unlock();
6284 			cond_resched();
6285 			if (loop_end(loop_end_arg, start_time))
6286 				return;
6287 			goto restart;
6288 		}
6289 		cpu_relax();
6290 	}
6291 	if (napi_poll)
6292 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6293 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6294 		preempt_enable();
6295 out:
6296 	rcu_read_unlock();
6297 }
6298 EXPORT_SYMBOL(napi_busy_loop);
6299 
6300 #endif /* CONFIG_NET_RX_BUSY_POLL */
6301 
6302 static void napi_hash_add(struct napi_struct *napi)
6303 {
6304 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6305 		return;
6306 
6307 	spin_lock(&napi_hash_lock);
6308 
6309 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6310 	do {
6311 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6312 			napi_gen_id = MIN_NAPI_ID;
6313 	} while (napi_by_id(napi_gen_id));
6314 	napi->napi_id = napi_gen_id;
6315 
6316 	hlist_add_head_rcu(&napi->napi_hash_node,
6317 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6318 
6319 	spin_unlock(&napi_hash_lock);
6320 }
6321 
6322 /* Warning : caller is responsible to make sure rcu grace period
6323  * is respected before freeing memory containing @napi
6324  */
6325 static void napi_hash_del(struct napi_struct *napi)
6326 {
6327 	spin_lock(&napi_hash_lock);
6328 
6329 	hlist_del_init_rcu(&napi->napi_hash_node);
6330 
6331 	spin_unlock(&napi_hash_lock);
6332 }
6333 
6334 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6335 {
6336 	struct napi_struct *napi;
6337 
6338 	napi = container_of(timer, struct napi_struct, timer);
6339 
6340 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6341 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6342 	 */
6343 	if (!napi_disable_pending(napi) &&
6344 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6345 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6346 		__napi_schedule_irqoff(napi);
6347 	}
6348 
6349 	return HRTIMER_NORESTART;
6350 }
6351 
6352 static void init_gro_hash(struct napi_struct *napi)
6353 {
6354 	int i;
6355 
6356 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6357 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6358 		napi->gro_hash[i].count = 0;
6359 	}
6360 	napi->gro_bitmask = 0;
6361 }
6362 
6363 int dev_set_threaded(struct net_device *dev, bool threaded)
6364 {
6365 	struct napi_struct *napi;
6366 	int err = 0;
6367 
6368 	if (dev->threaded == threaded)
6369 		return 0;
6370 
6371 	if (threaded) {
6372 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6373 			if (!napi->thread) {
6374 				err = napi_kthread_create(napi);
6375 				if (err) {
6376 					threaded = false;
6377 					break;
6378 				}
6379 			}
6380 		}
6381 	}
6382 
6383 	dev->threaded = threaded;
6384 
6385 	/* Make sure kthread is created before THREADED bit
6386 	 * is set.
6387 	 */
6388 	smp_mb__before_atomic();
6389 
6390 	/* Setting/unsetting threaded mode on a napi might not immediately
6391 	 * take effect, if the current napi instance is actively being
6392 	 * polled. In this case, the switch between threaded mode and
6393 	 * softirq mode will happen in the next round of napi_schedule().
6394 	 * This should not cause hiccups/stalls to the live traffic.
6395 	 */
6396 	list_for_each_entry(napi, &dev->napi_list, dev_list)
6397 		assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
6398 
6399 	return err;
6400 }
6401 EXPORT_SYMBOL(dev_set_threaded);
6402 
6403 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6404 			   int (*poll)(struct napi_struct *, int), int weight)
6405 {
6406 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6407 		return;
6408 
6409 	INIT_LIST_HEAD(&napi->poll_list);
6410 	INIT_HLIST_NODE(&napi->napi_hash_node);
6411 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6412 	napi->timer.function = napi_watchdog;
6413 	init_gro_hash(napi);
6414 	napi->skb = NULL;
6415 	INIT_LIST_HEAD(&napi->rx_list);
6416 	napi->rx_count = 0;
6417 	napi->poll = poll;
6418 	if (weight > NAPI_POLL_WEIGHT)
6419 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6420 				weight);
6421 	napi->weight = weight;
6422 	napi->dev = dev;
6423 #ifdef CONFIG_NETPOLL
6424 	napi->poll_owner = -1;
6425 #endif
6426 	napi->list_owner = -1;
6427 	set_bit(NAPI_STATE_SCHED, &napi->state);
6428 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6429 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6430 	napi_hash_add(napi);
6431 	napi_get_frags_check(napi);
6432 	/* Create kthread for this napi if dev->threaded is set.
6433 	 * Clear dev->threaded if kthread creation failed so that
6434 	 * threaded mode will not be enabled in napi_enable().
6435 	 */
6436 	if (dev->threaded && napi_kthread_create(napi))
6437 		dev->threaded = 0;
6438 }
6439 EXPORT_SYMBOL(netif_napi_add_weight);
6440 
6441 void napi_disable(struct napi_struct *n)
6442 {
6443 	unsigned long val, new;
6444 
6445 	might_sleep();
6446 	set_bit(NAPI_STATE_DISABLE, &n->state);
6447 
6448 	val = READ_ONCE(n->state);
6449 	do {
6450 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6451 			usleep_range(20, 200);
6452 			val = READ_ONCE(n->state);
6453 		}
6454 
6455 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6456 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6457 	} while (!try_cmpxchg(&n->state, &val, new));
6458 
6459 	hrtimer_cancel(&n->timer);
6460 
6461 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6462 }
6463 EXPORT_SYMBOL(napi_disable);
6464 
6465 /**
6466  *	napi_enable - enable NAPI scheduling
6467  *	@n: NAPI context
6468  *
6469  * Resume NAPI from being scheduled on this context.
6470  * Must be paired with napi_disable.
6471  */
6472 void napi_enable(struct napi_struct *n)
6473 {
6474 	unsigned long new, val = READ_ONCE(n->state);
6475 
6476 	do {
6477 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6478 
6479 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6480 		if (n->dev->threaded && n->thread)
6481 			new |= NAPIF_STATE_THREADED;
6482 	} while (!try_cmpxchg(&n->state, &val, new));
6483 }
6484 EXPORT_SYMBOL(napi_enable);
6485 
6486 static void flush_gro_hash(struct napi_struct *napi)
6487 {
6488 	int i;
6489 
6490 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6491 		struct sk_buff *skb, *n;
6492 
6493 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6494 			kfree_skb(skb);
6495 		napi->gro_hash[i].count = 0;
6496 	}
6497 }
6498 
6499 /* Must be called in process context */
6500 void __netif_napi_del(struct napi_struct *napi)
6501 {
6502 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6503 		return;
6504 
6505 	napi_hash_del(napi);
6506 	list_del_rcu(&napi->dev_list);
6507 	napi_free_frags(napi);
6508 
6509 	flush_gro_hash(napi);
6510 	napi->gro_bitmask = 0;
6511 
6512 	if (napi->thread) {
6513 		kthread_stop(napi->thread);
6514 		napi->thread = NULL;
6515 	}
6516 }
6517 EXPORT_SYMBOL(__netif_napi_del);
6518 
6519 static int __napi_poll(struct napi_struct *n, bool *repoll)
6520 {
6521 	int work, weight;
6522 
6523 	weight = n->weight;
6524 
6525 	/* This NAPI_STATE_SCHED test is for avoiding a race
6526 	 * with netpoll's poll_napi().  Only the entity which
6527 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6528 	 * actually make the ->poll() call.  Therefore we avoid
6529 	 * accidentally calling ->poll() when NAPI is not scheduled.
6530 	 */
6531 	work = 0;
6532 	if (napi_is_scheduled(n)) {
6533 		work = n->poll(n, weight);
6534 		trace_napi_poll(n, work, weight);
6535 
6536 		xdp_do_check_flushed(n);
6537 	}
6538 
6539 	if (unlikely(work > weight))
6540 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6541 				n->poll, work, weight);
6542 
6543 	if (likely(work < weight))
6544 		return work;
6545 
6546 	/* Drivers must not modify the NAPI state if they
6547 	 * consume the entire weight.  In such cases this code
6548 	 * still "owns" the NAPI instance and therefore can
6549 	 * move the instance around on the list at-will.
6550 	 */
6551 	if (unlikely(napi_disable_pending(n))) {
6552 		napi_complete(n);
6553 		return work;
6554 	}
6555 
6556 	/* The NAPI context has more processing work, but busy-polling
6557 	 * is preferred. Exit early.
6558 	 */
6559 	if (napi_prefer_busy_poll(n)) {
6560 		if (napi_complete_done(n, work)) {
6561 			/* If timeout is not set, we need to make sure
6562 			 * that the NAPI is re-scheduled.
6563 			 */
6564 			napi_schedule(n);
6565 		}
6566 		return work;
6567 	}
6568 
6569 	if (n->gro_bitmask) {
6570 		/* flush too old packets
6571 		 * If HZ < 1000, flush all packets.
6572 		 */
6573 		napi_gro_flush(n, HZ >= 1000);
6574 	}
6575 
6576 	gro_normal_list(n);
6577 
6578 	/* Some drivers may have called napi_schedule
6579 	 * prior to exhausting their budget.
6580 	 */
6581 	if (unlikely(!list_empty(&n->poll_list))) {
6582 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6583 			     n->dev ? n->dev->name : "backlog");
6584 		return work;
6585 	}
6586 
6587 	*repoll = true;
6588 
6589 	return work;
6590 }
6591 
6592 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6593 {
6594 	bool do_repoll = false;
6595 	void *have;
6596 	int work;
6597 
6598 	list_del_init(&n->poll_list);
6599 
6600 	have = netpoll_poll_lock(n);
6601 
6602 	work = __napi_poll(n, &do_repoll);
6603 
6604 	if (do_repoll)
6605 		list_add_tail(&n->poll_list, repoll);
6606 
6607 	netpoll_poll_unlock(have);
6608 
6609 	return work;
6610 }
6611 
6612 static int napi_thread_wait(struct napi_struct *napi)
6613 {
6614 	bool woken = false;
6615 
6616 	set_current_state(TASK_INTERRUPTIBLE);
6617 
6618 	while (!kthread_should_stop()) {
6619 		/* Testing SCHED_THREADED bit here to make sure the current
6620 		 * kthread owns this napi and could poll on this napi.
6621 		 * Testing SCHED bit is not enough because SCHED bit might be
6622 		 * set by some other busy poll thread or by napi_disable().
6623 		 */
6624 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6625 			WARN_ON(!list_empty(&napi->poll_list));
6626 			__set_current_state(TASK_RUNNING);
6627 			return 0;
6628 		}
6629 
6630 		schedule();
6631 		/* woken being true indicates this thread owns this napi. */
6632 		woken = true;
6633 		set_current_state(TASK_INTERRUPTIBLE);
6634 	}
6635 	__set_current_state(TASK_RUNNING);
6636 
6637 	return -1;
6638 }
6639 
6640 static void skb_defer_free_flush(struct softnet_data *sd)
6641 {
6642 	struct sk_buff *skb, *next;
6643 
6644 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6645 	if (!READ_ONCE(sd->defer_list))
6646 		return;
6647 
6648 	spin_lock(&sd->defer_lock);
6649 	skb = sd->defer_list;
6650 	sd->defer_list = NULL;
6651 	sd->defer_count = 0;
6652 	spin_unlock(&sd->defer_lock);
6653 
6654 	while (skb != NULL) {
6655 		next = skb->next;
6656 		napi_consume_skb(skb, 1);
6657 		skb = next;
6658 	}
6659 }
6660 
6661 static int napi_threaded_poll(void *data)
6662 {
6663 	struct napi_struct *napi = data;
6664 	struct softnet_data *sd;
6665 	void *have;
6666 
6667 	while (!napi_thread_wait(napi)) {
6668 		for (;;) {
6669 			bool repoll = false;
6670 
6671 			local_bh_disable();
6672 			sd = this_cpu_ptr(&softnet_data);
6673 			sd->in_napi_threaded_poll = true;
6674 
6675 			have = netpoll_poll_lock(napi);
6676 			__napi_poll(napi, &repoll);
6677 			netpoll_poll_unlock(have);
6678 
6679 			sd->in_napi_threaded_poll = false;
6680 			barrier();
6681 
6682 			if (sd_has_rps_ipi_waiting(sd)) {
6683 				local_irq_disable();
6684 				net_rps_action_and_irq_enable(sd);
6685 			}
6686 			skb_defer_free_flush(sd);
6687 			local_bh_enable();
6688 
6689 			if (!repoll)
6690 				break;
6691 
6692 			cond_resched();
6693 		}
6694 	}
6695 	return 0;
6696 }
6697 
6698 static __latent_entropy void net_rx_action(struct softirq_action *h)
6699 {
6700 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6701 	unsigned long time_limit = jiffies +
6702 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6703 	int budget = READ_ONCE(netdev_budget);
6704 	LIST_HEAD(list);
6705 	LIST_HEAD(repoll);
6706 
6707 start:
6708 	sd->in_net_rx_action = true;
6709 	local_irq_disable();
6710 	list_splice_init(&sd->poll_list, &list);
6711 	local_irq_enable();
6712 
6713 	for (;;) {
6714 		struct napi_struct *n;
6715 
6716 		skb_defer_free_flush(sd);
6717 
6718 		if (list_empty(&list)) {
6719 			if (list_empty(&repoll)) {
6720 				sd->in_net_rx_action = false;
6721 				barrier();
6722 				/* We need to check if ____napi_schedule()
6723 				 * had refilled poll_list while
6724 				 * sd->in_net_rx_action was true.
6725 				 */
6726 				if (!list_empty(&sd->poll_list))
6727 					goto start;
6728 				if (!sd_has_rps_ipi_waiting(sd))
6729 					goto end;
6730 			}
6731 			break;
6732 		}
6733 
6734 		n = list_first_entry(&list, struct napi_struct, poll_list);
6735 		budget -= napi_poll(n, &repoll);
6736 
6737 		/* If softirq window is exhausted then punt.
6738 		 * Allow this to run for 2 jiffies since which will allow
6739 		 * an average latency of 1.5/HZ.
6740 		 */
6741 		if (unlikely(budget <= 0 ||
6742 			     time_after_eq(jiffies, time_limit))) {
6743 			sd->time_squeeze++;
6744 			break;
6745 		}
6746 	}
6747 
6748 	local_irq_disable();
6749 
6750 	list_splice_tail_init(&sd->poll_list, &list);
6751 	list_splice_tail(&repoll, &list);
6752 	list_splice(&list, &sd->poll_list);
6753 	if (!list_empty(&sd->poll_list))
6754 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6755 	else
6756 		sd->in_net_rx_action = false;
6757 
6758 	net_rps_action_and_irq_enable(sd);
6759 end:;
6760 }
6761 
6762 struct netdev_adjacent {
6763 	struct net_device *dev;
6764 	netdevice_tracker dev_tracker;
6765 
6766 	/* upper master flag, there can only be one master device per list */
6767 	bool master;
6768 
6769 	/* lookup ignore flag */
6770 	bool ignore;
6771 
6772 	/* counter for the number of times this device was added to us */
6773 	u16 ref_nr;
6774 
6775 	/* private field for the users */
6776 	void *private;
6777 
6778 	struct list_head list;
6779 	struct rcu_head rcu;
6780 };
6781 
6782 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6783 						 struct list_head *adj_list)
6784 {
6785 	struct netdev_adjacent *adj;
6786 
6787 	list_for_each_entry(adj, adj_list, list) {
6788 		if (adj->dev == adj_dev)
6789 			return adj;
6790 	}
6791 	return NULL;
6792 }
6793 
6794 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6795 				    struct netdev_nested_priv *priv)
6796 {
6797 	struct net_device *dev = (struct net_device *)priv->data;
6798 
6799 	return upper_dev == dev;
6800 }
6801 
6802 /**
6803  * netdev_has_upper_dev - Check if device is linked to an upper device
6804  * @dev: device
6805  * @upper_dev: upper device to check
6806  *
6807  * Find out if a device is linked to specified upper device and return true
6808  * in case it is. Note that this checks only immediate upper device,
6809  * not through a complete stack of devices. The caller must hold the RTNL lock.
6810  */
6811 bool netdev_has_upper_dev(struct net_device *dev,
6812 			  struct net_device *upper_dev)
6813 {
6814 	struct netdev_nested_priv priv = {
6815 		.data = (void *)upper_dev,
6816 	};
6817 
6818 	ASSERT_RTNL();
6819 
6820 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6821 					     &priv);
6822 }
6823 EXPORT_SYMBOL(netdev_has_upper_dev);
6824 
6825 /**
6826  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6827  * @dev: device
6828  * @upper_dev: upper device to check
6829  *
6830  * Find out if a device is linked to specified upper device and return true
6831  * in case it is. Note that this checks the entire upper device chain.
6832  * The caller must hold rcu lock.
6833  */
6834 
6835 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6836 				  struct net_device *upper_dev)
6837 {
6838 	struct netdev_nested_priv priv = {
6839 		.data = (void *)upper_dev,
6840 	};
6841 
6842 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6843 					       &priv);
6844 }
6845 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6846 
6847 /**
6848  * netdev_has_any_upper_dev - Check if device is linked to some device
6849  * @dev: device
6850  *
6851  * Find out if a device is linked to an upper device and return true in case
6852  * it is. The caller must hold the RTNL lock.
6853  */
6854 bool netdev_has_any_upper_dev(struct net_device *dev)
6855 {
6856 	ASSERT_RTNL();
6857 
6858 	return !list_empty(&dev->adj_list.upper);
6859 }
6860 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6861 
6862 /**
6863  * netdev_master_upper_dev_get - Get master upper device
6864  * @dev: device
6865  *
6866  * Find a master upper device and return pointer to it or NULL in case
6867  * it's not there. The caller must hold the RTNL lock.
6868  */
6869 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6870 {
6871 	struct netdev_adjacent *upper;
6872 
6873 	ASSERT_RTNL();
6874 
6875 	if (list_empty(&dev->adj_list.upper))
6876 		return NULL;
6877 
6878 	upper = list_first_entry(&dev->adj_list.upper,
6879 				 struct netdev_adjacent, list);
6880 	if (likely(upper->master))
6881 		return upper->dev;
6882 	return NULL;
6883 }
6884 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6885 
6886 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6887 {
6888 	struct netdev_adjacent *upper;
6889 
6890 	ASSERT_RTNL();
6891 
6892 	if (list_empty(&dev->adj_list.upper))
6893 		return NULL;
6894 
6895 	upper = list_first_entry(&dev->adj_list.upper,
6896 				 struct netdev_adjacent, list);
6897 	if (likely(upper->master) && !upper->ignore)
6898 		return upper->dev;
6899 	return NULL;
6900 }
6901 
6902 /**
6903  * netdev_has_any_lower_dev - Check if device is linked to some device
6904  * @dev: device
6905  *
6906  * Find out if a device is linked to a lower device and return true in case
6907  * it is. The caller must hold the RTNL lock.
6908  */
6909 static bool netdev_has_any_lower_dev(struct net_device *dev)
6910 {
6911 	ASSERT_RTNL();
6912 
6913 	return !list_empty(&dev->adj_list.lower);
6914 }
6915 
6916 void *netdev_adjacent_get_private(struct list_head *adj_list)
6917 {
6918 	struct netdev_adjacent *adj;
6919 
6920 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6921 
6922 	return adj->private;
6923 }
6924 EXPORT_SYMBOL(netdev_adjacent_get_private);
6925 
6926 /**
6927  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6928  * @dev: device
6929  * @iter: list_head ** of the current position
6930  *
6931  * Gets the next device from the dev's upper list, starting from iter
6932  * position. The caller must hold RCU read lock.
6933  */
6934 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6935 						 struct list_head **iter)
6936 {
6937 	struct netdev_adjacent *upper;
6938 
6939 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6940 
6941 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6942 
6943 	if (&upper->list == &dev->adj_list.upper)
6944 		return NULL;
6945 
6946 	*iter = &upper->list;
6947 
6948 	return upper->dev;
6949 }
6950 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6951 
6952 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6953 						  struct list_head **iter,
6954 						  bool *ignore)
6955 {
6956 	struct netdev_adjacent *upper;
6957 
6958 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6959 
6960 	if (&upper->list == &dev->adj_list.upper)
6961 		return NULL;
6962 
6963 	*iter = &upper->list;
6964 	*ignore = upper->ignore;
6965 
6966 	return upper->dev;
6967 }
6968 
6969 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6970 						    struct list_head **iter)
6971 {
6972 	struct netdev_adjacent *upper;
6973 
6974 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6975 
6976 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6977 
6978 	if (&upper->list == &dev->adj_list.upper)
6979 		return NULL;
6980 
6981 	*iter = &upper->list;
6982 
6983 	return upper->dev;
6984 }
6985 
6986 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6987 				       int (*fn)(struct net_device *dev,
6988 					 struct netdev_nested_priv *priv),
6989 				       struct netdev_nested_priv *priv)
6990 {
6991 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6992 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6993 	int ret, cur = 0;
6994 	bool ignore;
6995 
6996 	now = dev;
6997 	iter = &dev->adj_list.upper;
6998 
6999 	while (1) {
7000 		if (now != dev) {
7001 			ret = fn(now, priv);
7002 			if (ret)
7003 				return ret;
7004 		}
7005 
7006 		next = NULL;
7007 		while (1) {
7008 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
7009 			if (!udev)
7010 				break;
7011 			if (ignore)
7012 				continue;
7013 
7014 			next = udev;
7015 			niter = &udev->adj_list.upper;
7016 			dev_stack[cur] = now;
7017 			iter_stack[cur++] = iter;
7018 			break;
7019 		}
7020 
7021 		if (!next) {
7022 			if (!cur)
7023 				return 0;
7024 			next = dev_stack[--cur];
7025 			niter = iter_stack[cur];
7026 		}
7027 
7028 		now = next;
7029 		iter = niter;
7030 	}
7031 
7032 	return 0;
7033 }
7034 
7035 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
7036 				  int (*fn)(struct net_device *dev,
7037 					    struct netdev_nested_priv *priv),
7038 				  struct netdev_nested_priv *priv)
7039 {
7040 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7041 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7042 	int ret, cur = 0;
7043 
7044 	now = dev;
7045 	iter = &dev->adj_list.upper;
7046 
7047 	while (1) {
7048 		if (now != dev) {
7049 			ret = fn(now, priv);
7050 			if (ret)
7051 				return ret;
7052 		}
7053 
7054 		next = NULL;
7055 		while (1) {
7056 			udev = netdev_next_upper_dev_rcu(now, &iter);
7057 			if (!udev)
7058 				break;
7059 
7060 			next = udev;
7061 			niter = &udev->adj_list.upper;
7062 			dev_stack[cur] = now;
7063 			iter_stack[cur++] = iter;
7064 			break;
7065 		}
7066 
7067 		if (!next) {
7068 			if (!cur)
7069 				return 0;
7070 			next = dev_stack[--cur];
7071 			niter = iter_stack[cur];
7072 		}
7073 
7074 		now = next;
7075 		iter = niter;
7076 	}
7077 
7078 	return 0;
7079 }
7080 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7081 
7082 static bool __netdev_has_upper_dev(struct net_device *dev,
7083 				   struct net_device *upper_dev)
7084 {
7085 	struct netdev_nested_priv priv = {
7086 		.flags = 0,
7087 		.data = (void *)upper_dev,
7088 	};
7089 
7090 	ASSERT_RTNL();
7091 
7092 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7093 					   &priv);
7094 }
7095 
7096 /**
7097  * netdev_lower_get_next_private - Get the next ->private from the
7098  *				   lower neighbour list
7099  * @dev: device
7100  * @iter: list_head ** of the current position
7101  *
7102  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7103  * list, starting from iter position. The caller must hold either hold the
7104  * RTNL lock or its own locking that guarantees that the neighbour lower
7105  * list will remain unchanged.
7106  */
7107 void *netdev_lower_get_next_private(struct net_device *dev,
7108 				    struct list_head **iter)
7109 {
7110 	struct netdev_adjacent *lower;
7111 
7112 	lower = list_entry(*iter, struct netdev_adjacent, list);
7113 
7114 	if (&lower->list == &dev->adj_list.lower)
7115 		return NULL;
7116 
7117 	*iter = lower->list.next;
7118 
7119 	return lower->private;
7120 }
7121 EXPORT_SYMBOL(netdev_lower_get_next_private);
7122 
7123 /**
7124  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7125  *				       lower neighbour list, RCU
7126  *				       variant
7127  * @dev: device
7128  * @iter: list_head ** of the current position
7129  *
7130  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7131  * list, starting from iter position. The caller must hold RCU read lock.
7132  */
7133 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7134 					struct list_head **iter)
7135 {
7136 	struct netdev_adjacent *lower;
7137 
7138 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7139 
7140 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7141 
7142 	if (&lower->list == &dev->adj_list.lower)
7143 		return NULL;
7144 
7145 	*iter = &lower->list;
7146 
7147 	return lower->private;
7148 }
7149 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7150 
7151 /**
7152  * netdev_lower_get_next - Get the next device from the lower neighbour
7153  *                         list
7154  * @dev: device
7155  * @iter: list_head ** of the current position
7156  *
7157  * Gets the next netdev_adjacent from the dev's lower neighbour
7158  * list, starting from iter position. The caller must hold RTNL lock or
7159  * its own locking that guarantees that the neighbour lower
7160  * list will remain unchanged.
7161  */
7162 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7163 {
7164 	struct netdev_adjacent *lower;
7165 
7166 	lower = list_entry(*iter, struct netdev_adjacent, list);
7167 
7168 	if (&lower->list == &dev->adj_list.lower)
7169 		return NULL;
7170 
7171 	*iter = lower->list.next;
7172 
7173 	return lower->dev;
7174 }
7175 EXPORT_SYMBOL(netdev_lower_get_next);
7176 
7177 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7178 						struct list_head **iter)
7179 {
7180 	struct netdev_adjacent *lower;
7181 
7182 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7183 
7184 	if (&lower->list == &dev->adj_list.lower)
7185 		return NULL;
7186 
7187 	*iter = &lower->list;
7188 
7189 	return lower->dev;
7190 }
7191 
7192 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7193 						  struct list_head **iter,
7194 						  bool *ignore)
7195 {
7196 	struct netdev_adjacent *lower;
7197 
7198 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7199 
7200 	if (&lower->list == &dev->adj_list.lower)
7201 		return NULL;
7202 
7203 	*iter = &lower->list;
7204 	*ignore = lower->ignore;
7205 
7206 	return lower->dev;
7207 }
7208 
7209 int netdev_walk_all_lower_dev(struct net_device *dev,
7210 			      int (*fn)(struct net_device *dev,
7211 					struct netdev_nested_priv *priv),
7212 			      struct netdev_nested_priv *priv)
7213 {
7214 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7215 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7216 	int ret, cur = 0;
7217 
7218 	now = dev;
7219 	iter = &dev->adj_list.lower;
7220 
7221 	while (1) {
7222 		if (now != dev) {
7223 			ret = fn(now, priv);
7224 			if (ret)
7225 				return ret;
7226 		}
7227 
7228 		next = NULL;
7229 		while (1) {
7230 			ldev = netdev_next_lower_dev(now, &iter);
7231 			if (!ldev)
7232 				break;
7233 
7234 			next = ldev;
7235 			niter = &ldev->adj_list.lower;
7236 			dev_stack[cur] = now;
7237 			iter_stack[cur++] = iter;
7238 			break;
7239 		}
7240 
7241 		if (!next) {
7242 			if (!cur)
7243 				return 0;
7244 			next = dev_stack[--cur];
7245 			niter = iter_stack[cur];
7246 		}
7247 
7248 		now = next;
7249 		iter = niter;
7250 	}
7251 
7252 	return 0;
7253 }
7254 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7255 
7256 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7257 				       int (*fn)(struct net_device *dev,
7258 					 struct netdev_nested_priv *priv),
7259 				       struct netdev_nested_priv *priv)
7260 {
7261 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7262 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7263 	int ret, cur = 0;
7264 	bool ignore;
7265 
7266 	now = dev;
7267 	iter = &dev->adj_list.lower;
7268 
7269 	while (1) {
7270 		if (now != dev) {
7271 			ret = fn(now, priv);
7272 			if (ret)
7273 				return ret;
7274 		}
7275 
7276 		next = NULL;
7277 		while (1) {
7278 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7279 			if (!ldev)
7280 				break;
7281 			if (ignore)
7282 				continue;
7283 
7284 			next = ldev;
7285 			niter = &ldev->adj_list.lower;
7286 			dev_stack[cur] = now;
7287 			iter_stack[cur++] = iter;
7288 			break;
7289 		}
7290 
7291 		if (!next) {
7292 			if (!cur)
7293 				return 0;
7294 			next = dev_stack[--cur];
7295 			niter = iter_stack[cur];
7296 		}
7297 
7298 		now = next;
7299 		iter = niter;
7300 	}
7301 
7302 	return 0;
7303 }
7304 
7305 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7306 					     struct list_head **iter)
7307 {
7308 	struct netdev_adjacent *lower;
7309 
7310 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7311 	if (&lower->list == &dev->adj_list.lower)
7312 		return NULL;
7313 
7314 	*iter = &lower->list;
7315 
7316 	return lower->dev;
7317 }
7318 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7319 
7320 static u8 __netdev_upper_depth(struct net_device *dev)
7321 {
7322 	struct net_device *udev;
7323 	struct list_head *iter;
7324 	u8 max_depth = 0;
7325 	bool ignore;
7326 
7327 	for (iter = &dev->adj_list.upper,
7328 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7329 	     udev;
7330 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7331 		if (ignore)
7332 			continue;
7333 		if (max_depth < udev->upper_level)
7334 			max_depth = udev->upper_level;
7335 	}
7336 
7337 	return max_depth;
7338 }
7339 
7340 static u8 __netdev_lower_depth(struct net_device *dev)
7341 {
7342 	struct net_device *ldev;
7343 	struct list_head *iter;
7344 	u8 max_depth = 0;
7345 	bool ignore;
7346 
7347 	for (iter = &dev->adj_list.lower,
7348 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7349 	     ldev;
7350 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7351 		if (ignore)
7352 			continue;
7353 		if (max_depth < ldev->lower_level)
7354 			max_depth = ldev->lower_level;
7355 	}
7356 
7357 	return max_depth;
7358 }
7359 
7360 static int __netdev_update_upper_level(struct net_device *dev,
7361 				       struct netdev_nested_priv *__unused)
7362 {
7363 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7364 	return 0;
7365 }
7366 
7367 #ifdef CONFIG_LOCKDEP
7368 static LIST_HEAD(net_unlink_list);
7369 
7370 static void net_unlink_todo(struct net_device *dev)
7371 {
7372 	if (list_empty(&dev->unlink_list))
7373 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7374 }
7375 #endif
7376 
7377 static int __netdev_update_lower_level(struct net_device *dev,
7378 				       struct netdev_nested_priv *priv)
7379 {
7380 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7381 
7382 #ifdef CONFIG_LOCKDEP
7383 	if (!priv)
7384 		return 0;
7385 
7386 	if (priv->flags & NESTED_SYNC_IMM)
7387 		dev->nested_level = dev->lower_level - 1;
7388 	if (priv->flags & NESTED_SYNC_TODO)
7389 		net_unlink_todo(dev);
7390 #endif
7391 	return 0;
7392 }
7393 
7394 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7395 				  int (*fn)(struct net_device *dev,
7396 					    struct netdev_nested_priv *priv),
7397 				  struct netdev_nested_priv *priv)
7398 {
7399 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7400 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7401 	int ret, cur = 0;
7402 
7403 	now = dev;
7404 	iter = &dev->adj_list.lower;
7405 
7406 	while (1) {
7407 		if (now != dev) {
7408 			ret = fn(now, priv);
7409 			if (ret)
7410 				return ret;
7411 		}
7412 
7413 		next = NULL;
7414 		while (1) {
7415 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7416 			if (!ldev)
7417 				break;
7418 
7419 			next = ldev;
7420 			niter = &ldev->adj_list.lower;
7421 			dev_stack[cur] = now;
7422 			iter_stack[cur++] = iter;
7423 			break;
7424 		}
7425 
7426 		if (!next) {
7427 			if (!cur)
7428 				return 0;
7429 			next = dev_stack[--cur];
7430 			niter = iter_stack[cur];
7431 		}
7432 
7433 		now = next;
7434 		iter = niter;
7435 	}
7436 
7437 	return 0;
7438 }
7439 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7440 
7441 /**
7442  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7443  *				       lower neighbour list, RCU
7444  *				       variant
7445  * @dev: device
7446  *
7447  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7448  * list. The caller must hold RCU read lock.
7449  */
7450 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7451 {
7452 	struct netdev_adjacent *lower;
7453 
7454 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7455 			struct netdev_adjacent, list);
7456 	if (lower)
7457 		return lower->private;
7458 	return NULL;
7459 }
7460 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7461 
7462 /**
7463  * netdev_master_upper_dev_get_rcu - Get master upper device
7464  * @dev: device
7465  *
7466  * Find a master upper device and return pointer to it or NULL in case
7467  * it's not there. The caller must hold the RCU read lock.
7468  */
7469 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7470 {
7471 	struct netdev_adjacent *upper;
7472 
7473 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7474 				       struct netdev_adjacent, list);
7475 	if (upper && likely(upper->master))
7476 		return upper->dev;
7477 	return NULL;
7478 }
7479 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7480 
7481 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7482 			      struct net_device *adj_dev,
7483 			      struct list_head *dev_list)
7484 {
7485 	char linkname[IFNAMSIZ+7];
7486 
7487 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7488 		"upper_%s" : "lower_%s", adj_dev->name);
7489 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7490 				 linkname);
7491 }
7492 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7493 			       char *name,
7494 			       struct list_head *dev_list)
7495 {
7496 	char linkname[IFNAMSIZ+7];
7497 
7498 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7499 		"upper_%s" : "lower_%s", name);
7500 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7501 }
7502 
7503 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7504 						 struct net_device *adj_dev,
7505 						 struct list_head *dev_list)
7506 {
7507 	return (dev_list == &dev->adj_list.upper ||
7508 		dev_list == &dev->adj_list.lower) &&
7509 		net_eq(dev_net(dev), dev_net(adj_dev));
7510 }
7511 
7512 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7513 					struct net_device *adj_dev,
7514 					struct list_head *dev_list,
7515 					void *private, bool master)
7516 {
7517 	struct netdev_adjacent *adj;
7518 	int ret;
7519 
7520 	adj = __netdev_find_adj(adj_dev, dev_list);
7521 
7522 	if (adj) {
7523 		adj->ref_nr += 1;
7524 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7525 			 dev->name, adj_dev->name, adj->ref_nr);
7526 
7527 		return 0;
7528 	}
7529 
7530 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7531 	if (!adj)
7532 		return -ENOMEM;
7533 
7534 	adj->dev = adj_dev;
7535 	adj->master = master;
7536 	adj->ref_nr = 1;
7537 	adj->private = private;
7538 	adj->ignore = false;
7539 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7540 
7541 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7542 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7543 
7544 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7545 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7546 		if (ret)
7547 			goto free_adj;
7548 	}
7549 
7550 	/* Ensure that master link is always the first item in list. */
7551 	if (master) {
7552 		ret = sysfs_create_link(&(dev->dev.kobj),
7553 					&(adj_dev->dev.kobj), "master");
7554 		if (ret)
7555 			goto remove_symlinks;
7556 
7557 		list_add_rcu(&adj->list, dev_list);
7558 	} else {
7559 		list_add_tail_rcu(&adj->list, dev_list);
7560 	}
7561 
7562 	return 0;
7563 
7564 remove_symlinks:
7565 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7566 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7567 free_adj:
7568 	netdev_put(adj_dev, &adj->dev_tracker);
7569 	kfree(adj);
7570 
7571 	return ret;
7572 }
7573 
7574 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7575 					 struct net_device *adj_dev,
7576 					 u16 ref_nr,
7577 					 struct list_head *dev_list)
7578 {
7579 	struct netdev_adjacent *adj;
7580 
7581 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7582 		 dev->name, adj_dev->name, ref_nr);
7583 
7584 	adj = __netdev_find_adj(adj_dev, dev_list);
7585 
7586 	if (!adj) {
7587 		pr_err("Adjacency does not exist for device %s from %s\n",
7588 		       dev->name, adj_dev->name);
7589 		WARN_ON(1);
7590 		return;
7591 	}
7592 
7593 	if (adj->ref_nr > ref_nr) {
7594 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7595 			 dev->name, adj_dev->name, ref_nr,
7596 			 adj->ref_nr - ref_nr);
7597 		adj->ref_nr -= ref_nr;
7598 		return;
7599 	}
7600 
7601 	if (adj->master)
7602 		sysfs_remove_link(&(dev->dev.kobj), "master");
7603 
7604 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7605 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7606 
7607 	list_del_rcu(&adj->list);
7608 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7609 		 adj_dev->name, dev->name, adj_dev->name);
7610 	netdev_put(adj_dev, &adj->dev_tracker);
7611 	kfree_rcu(adj, rcu);
7612 }
7613 
7614 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7615 					    struct net_device *upper_dev,
7616 					    struct list_head *up_list,
7617 					    struct list_head *down_list,
7618 					    void *private, bool master)
7619 {
7620 	int ret;
7621 
7622 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7623 					   private, master);
7624 	if (ret)
7625 		return ret;
7626 
7627 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7628 					   private, false);
7629 	if (ret) {
7630 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7631 		return ret;
7632 	}
7633 
7634 	return 0;
7635 }
7636 
7637 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7638 					       struct net_device *upper_dev,
7639 					       u16 ref_nr,
7640 					       struct list_head *up_list,
7641 					       struct list_head *down_list)
7642 {
7643 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7644 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7645 }
7646 
7647 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7648 						struct net_device *upper_dev,
7649 						void *private, bool master)
7650 {
7651 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7652 						&dev->adj_list.upper,
7653 						&upper_dev->adj_list.lower,
7654 						private, master);
7655 }
7656 
7657 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7658 						   struct net_device *upper_dev)
7659 {
7660 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7661 					   &dev->adj_list.upper,
7662 					   &upper_dev->adj_list.lower);
7663 }
7664 
7665 static int __netdev_upper_dev_link(struct net_device *dev,
7666 				   struct net_device *upper_dev, bool master,
7667 				   void *upper_priv, void *upper_info,
7668 				   struct netdev_nested_priv *priv,
7669 				   struct netlink_ext_ack *extack)
7670 {
7671 	struct netdev_notifier_changeupper_info changeupper_info = {
7672 		.info = {
7673 			.dev = dev,
7674 			.extack = extack,
7675 		},
7676 		.upper_dev = upper_dev,
7677 		.master = master,
7678 		.linking = true,
7679 		.upper_info = upper_info,
7680 	};
7681 	struct net_device *master_dev;
7682 	int ret = 0;
7683 
7684 	ASSERT_RTNL();
7685 
7686 	if (dev == upper_dev)
7687 		return -EBUSY;
7688 
7689 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7690 	if (__netdev_has_upper_dev(upper_dev, dev))
7691 		return -EBUSY;
7692 
7693 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7694 		return -EMLINK;
7695 
7696 	if (!master) {
7697 		if (__netdev_has_upper_dev(dev, upper_dev))
7698 			return -EEXIST;
7699 	} else {
7700 		master_dev = __netdev_master_upper_dev_get(dev);
7701 		if (master_dev)
7702 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7703 	}
7704 
7705 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7706 					    &changeupper_info.info);
7707 	ret = notifier_to_errno(ret);
7708 	if (ret)
7709 		return ret;
7710 
7711 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7712 						   master);
7713 	if (ret)
7714 		return ret;
7715 
7716 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7717 					    &changeupper_info.info);
7718 	ret = notifier_to_errno(ret);
7719 	if (ret)
7720 		goto rollback;
7721 
7722 	__netdev_update_upper_level(dev, NULL);
7723 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7724 
7725 	__netdev_update_lower_level(upper_dev, priv);
7726 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7727 				    priv);
7728 
7729 	return 0;
7730 
7731 rollback:
7732 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7733 
7734 	return ret;
7735 }
7736 
7737 /**
7738  * netdev_upper_dev_link - Add a link to the upper device
7739  * @dev: device
7740  * @upper_dev: new upper device
7741  * @extack: netlink extended ack
7742  *
7743  * Adds a link to device which is upper to this one. The caller must hold
7744  * the RTNL lock. On a failure a negative errno code is returned.
7745  * On success the reference counts are adjusted and the function
7746  * returns zero.
7747  */
7748 int netdev_upper_dev_link(struct net_device *dev,
7749 			  struct net_device *upper_dev,
7750 			  struct netlink_ext_ack *extack)
7751 {
7752 	struct netdev_nested_priv priv = {
7753 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7754 		.data = NULL,
7755 	};
7756 
7757 	return __netdev_upper_dev_link(dev, upper_dev, false,
7758 				       NULL, NULL, &priv, extack);
7759 }
7760 EXPORT_SYMBOL(netdev_upper_dev_link);
7761 
7762 /**
7763  * netdev_master_upper_dev_link - Add a master link to the upper device
7764  * @dev: device
7765  * @upper_dev: new upper device
7766  * @upper_priv: upper device private
7767  * @upper_info: upper info to be passed down via notifier
7768  * @extack: netlink extended ack
7769  *
7770  * Adds a link to device which is upper to this one. In this case, only
7771  * one master upper device can be linked, although other non-master devices
7772  * might be linked as well. The caller must hold the RTNL lock.
7773  * On a failure a negative errno code is returned. On success the reference
7774  * counts are adjusted and the function returns zero.
7775  */
7776 int netdev_master_upper_dev_link(struct net_device *dev,
7777 				 struct net_device *upper_dev,
7778 				 void *upper_priv, void *upper_info,
7779 				 struct netlink_ext_ack *extack)
7780 {
7781 	struct netdev_nested_priv priv = {
7782 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7783 		.data = NULL,
7784 	};
7785 
7786 	return __netdev_upper_dev_link(dev, upper_dev, true,
7787 				       upper_priv, upper_info, &priv, extack);
7788 }
7789 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7790 
7791 static void __netdev_upper_dev_unlink(struct net_device *dev,
7792 				      struct net_device *upper_dev,
7793 				      struct netdev_nested_priv *priv)
7794 {
7795 	struct netdev_notifier_changeupper_info changeupper_info = {
7796 		.info = {
7797 			.dev = dev,
7798 		},
7799 		.upper_dev = upper_dev,
7800 		.linking = false,
7801 	};
7802 
7803 	ASSERT_RTNL();
7804 
7805 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7806 
7807 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7808 				      &changeupper_info.info);
7809 
7810 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7811 
7812 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7813 				      &changeupper_info.info);
7814 
7815 	__netdev_update_upper_level(dev, NULL);
7816 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7817 
7818 	__netdev_update_lower_level(upper_dev, priv);
7819 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7820 				    priv);
7821 }
7822 
7823 /**
7824  * netdev_upper_dev_unlink - Removes a link to upper device
7825  * @dev: device
7826  * @upper_dev: new upper device
7827  *
7828  * Removes a link to device which is upper to this one. The caller must hold
7829  * the RTNL lock.
7830  */
7831 void netdev_upper_dev_unlink(struct net_device *dev,
7832 			     struct net_device *upper_dev)
7833 {
7834 	struct netdev_nested_priv priv = {
7835 		.flags = NESTED_SYNC_TODO,
7836 		.data = NULL,
7837 	};
7838 
7839 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7840 }
7841 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7842 
7843 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7844 				      struct net_device *lower_dev,
7845 				      bool val)
7846 {
7847 	struct netdev_adjacent *adj;
7848 
7849 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7850 	if (adj)
7851 		adj->ignore = val;
7852 
7853 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7854 	if (adj)
7855 		adj->ignore = val;
7856 }
7857 
7858 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7859 					struct net_device *lower_dev)
7860 {
7861 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7862 }
7863 
7864 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7865 				       struct net_device *lower_dev)
7866 {
7867 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7868 }
7869 
7870 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7871 				   struct net_device *new_dev,
7872 				   struct net_device *dev,
7873 				   struct netlink_ext_ack *extack)
7874 {
7875 	struct netdev_nested_priv priv = {
7876 		.flags = 0,
7877 		.data = NULL,
7878 	};
7879 	int err;
7880 
7881 	if (!new_dev)
7882 		return 0;
7883 
7884 	if (old_dev && new_dev != old_dev)
7885 		netdev_adjacent_dev_disable(dev, old_dev);
7886 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7887 				      extack);
7888 	if (err) {
7889 		if (old_dev && new_dev != old_dev)
7890 			netdev_adjacent_dev_enable(dev, old_dev);
7891 		return err;
7892 	}
7893 
7894 	return 0;
7895 }
7896 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7897 
7898 void netdev_adjacent_change_commit(struct net_device *old_dev,
7899 				   struct net_device *new_dev,
7900 				   struct net_device *dev)
7901 {
7902 	struct netdev_nested_priv priv = {
7903 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7904 		.data = NULL,
7905 	};
7906 
7907 	if (!new_dev || !old_dev)
7908 		return;
7909 
7910 	if (new_dev == old_dev)
7911 		return;
7912 
7913 	netdev_adjacent_dev_enable(dev, old_dev);
7914 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7915 }
7916 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7917 
7918 void netdev_adjacent_change_abort(struct net_device *old_dev,
7919 				  struct net_device *new_dev,
7920 				  struct net_device *dev)
7921 {
7922 	struct netdev_nested_priv priv = {
7923 		.flags = 0,
7924 		.data = NULL,
7925 	};
7926 
7927 	if (!new_dev)
7928 		return;
7929 
7930 	if (old_dev && new_dev != old_dev)
7931 		netdev_adjacent_dev_enable(dev, old_dev);
7932 
7933 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7934 }
7935 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7936 
7937 /**
7938  * netdev_bonding_info_change - Dispatch event about slave change
7939  * @dev: device
7940  * @bonding_info: info to dispatch
7941  *
7942  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7943  * The caller must hold the RTNL lock.
7944  */
7945 void netdev_bonding_info_change(struct net_device *dev,
7946 				struct netdev_bonding_info *bonding_info)
7947 {
7948 	struct netdev_notifier_bonding_info info = {
7949 		.info.dev = dev,
7950 	};
7951 
7952 	memcpy(&info.bonding_info, bonding_info,
7953 	       sizeof(struct netdev_bonding_info));
7954 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7955 				      &info.info);
7956 }
7957 EXPORT_SYMBOL(netdev_bonding_info_change);
7958 
7959 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7960 					   struct netlink_ext_ack *extack)
7961 {
7962 	struct netdev_notifier_offload_xstats_info info = {
7963 		.info.dev = dev,
7964 		.info.extack = extack,
7965 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7966 	};
7967 	int err;
7968 	int rc;
7969 
7970 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7971 					 GFP_KERNEL);
7972 	if (!dev->offload_xstats_l3)
7973 		return -ENOMEM;
7974 
7975 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7976 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7977 						  &info.info);
7978 	err = notifier_to_errno(rc);
7979 	if (err)
7980 		goto free_stats;
7981 
7982 	return 0;
7983 
7984 free_stats:
7985 	kfree(dev->offload_xstats_l3);
7986 	dev->offload_xstats_l3 = NULL;
7987 	return err;
7988 }
7989 
7990 int netdev_offload_xstats_enable(struct net_device *dev,
7991 				 enum netdev_offload_xstats_type type,
7992 				 struct netlink_ext_ack *extack)
7993 {
7994 	ASSERT_RTNL();
7995 
7996 	if (netdev_offload_xstats_enabled(dev, type))
7997 		return -EALREADY;
7998 
7999 	switch (type) {
8000 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8001 		return netdev_offload_xstats_enable_l3(dev, extack);
8002 	}
8003 
8004 	WARN_ON(1);
8005 	return -EINVAL;
8006 }
8007 EXPORT_SYMBOL(netdev_offload_xstats_enable);
8008 
8009 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
8010 {
8011 	struct netdev_notifier_offload_xstats_info info = {
8012 		.info.dev = dev,
8013 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
8014 	};
8015 
8016 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
8017 				      &info.info);
8018 	kfree(dev->offload_xstats_l3);
8019 	dev->offload_xstats_l3 = NULL;
8020 }
8021 
8022 int netdev_offload_xstats_disable(struct net_device *dev,
8023 				  enum netdev_offload_xstats_type type)
8024 {
8025 	ASSERT_RTNL();
8026 
8027 	if (!netdev_offload_xstats_enabled(dev, type))
8028 		return -EALREADY;
8029 
8030 	switch (type) {
8031 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8032 		netdev_offload_xstats_disable_l3(dev);
8033 		return 0;
8034 	}
8035 
8036 	WARN_ON(1);
8037 	return -EINVAL;
8038 }
8039 EXPORT_SYMBOL(netdev_offload_xstats_disable);
8040 
8041 static void netdev_offload_xstats_disable_all(struct net_device *dev)
8042 {
8043 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
8044 }
8045 
8046 static struct rtnl_hw_stats64 *
8047 netdev_offload_xstats_get_ptr(const struct net_device *dev,
8048 			      enum netdev_offload_xstats_type type)
8049 {
8050 	switch (type) {
8051 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8052 		return dev->offload_xstats_l3;
8053 	}
8054 
8055 	WARN_ON(1);
8056 	return NULL;
8057 }
8058 
8059 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8060 				   enum netdev_offload_xstats_type type)
8061 {
8062 	ASSERT_RTNL();
8063 
8064 	return netdev_offload_xstats_get_ptr(dev, type);
8065 }
8066 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8067 
8068 struct netdev_notifier_offload_xstats_ru {
8069 	bool used;
8070 };
8071 
8072 struct netdev_notifier_offload_xstats_rd {
8073 	struct rtnl_hw_stats64 stats;
8074 	bool used;
8075 };
8076 
8077 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8078 				  const struct rtnl_hw_stats64 *src)
8079 {
8080 	dest->rx_packets	  += src->rx_packets;
8081 	dest->tx_packets	  += src->tx_packets;
8082 	dest->rx_bytes		  += src->rx_bytes;
8083 	dest->tx_bytes		  += src->tx_bytes;
8084 	dest->rx_errors		  += src->rx_errors;
8085 	dest->tx_errors		  += src->tx_errors;
8086 	dest->rx_dropped	  += src->rx_dropped;
8087 	dest->tx_dropped	  += src->tx_dropped;
8088 	dest->multicast		  += src->multicast;
8089 }
8090 
8091 static int netdev_offload_xstats_get_used(struct net_device *dev,
8092 					  enum netdev_offload_xstats_type type,
8093 					  bool *p_used,
8094 					  struct netlink_ext_ack *extack)
8095 {
8096 	struct netdev_notifier_offload_xstats_ru report_used = {};
8097 	struct netdev_notifier_offload_xstats_info info = {
8098 		.info.dev = dev,
8099 		.info.extack = extack,
8100 		.type = type,
8101 		.report_used = &report_used,
8102 	};
8103 	int rc;
8104 
8105 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8106 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8107 					   &info.info);
8108 	*p_used = report_used.used;
8109 	return notifier_to_errno(rc);
8110 }
8111 
8112 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8113 					   enum netdev_offload_xstats_type type,
8114 					   struct rtnl_hw_stats64 *p_stats,
8115 					   bool *p_used,
8116 					   struct netlink_ext_ack *extack)
8117 {
8118 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8119 	struct netdev_notifier_offload_xstats_info info = {
8120 		.info.dev = dev,
8121 		.info.extack = extack,
8122 		.type = type,
8123 		.report_delta = &report_delta,
8124 	};
8125 	struct rtnl_hw_stats64 *stats;
8126 	int rc;
8127 
8128 	stats = netdev_offload_xstats_get_ptr(dev, type);
8129 	if (WARN_ON(!stats))
8130 		return -EINVAL;
8131 
8132 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8133 					   &info.info);
8134 
8135 	/* Cache whatever we got, even if there was an error, otherwise the
8136 	 * successful stats retrievals would get lost.
8137 	 */
8138 	netdev_hw_stats64_add(stats, &report_delta.stats);
8139 
8140 	if (p_stats)
8141 		*p_stats = *stats;
8142 	*p_used = report_delta.used;
8143 
8144 	return notifier_to_errno(rc);
8145 }
8146 
8147 int netdev_offload_xstats_get(struct net_device *dev,
8148 			      enum netdev_offload_xstats_type type,
8149 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8150 			      struct netlink_ext_ack *extack)
8151 {
8152 	ASSERT_RTNL();
8153 
8154 	if (p_stats)
8155 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8156 						       p_used, extack);
8157 	else
8158 		return netdev_offload_xstats_get_used(dev, type, p_used,
8159 						      extack);
8160 }
8161 EXPORT_SYMBOL(netdev_offload_xstats_get);
8162 
8163 void
8164 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8165 				   const struct rtnl_hw_stats64 *stats)
8166 {
8167 	report_delta->used = true;
8168 	netdev_hw_stats64_add(&report_delta->stats, stats);
8169 }
8170 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8171 
8172 void
8173 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8174 {
8175 	report_used->used = true;
8176 }
8177 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8178 
8179 void netdev_offload_xstats_push_delta(struct net_device *dev,
8180 				      enum netdev_offload_xstats_type type,
8181 				      const struct rtnl_hw_stats64 *p_stats)
8182 {
8183 	struct rtnl_hw_stats64 *stats;
8184 
8185 	ASSERT_RTNL();
8186 
8187 	stats = netdev_offload_xstats_get_ptr(dev, type);
8188 	if (WARN_ON(!stats))
8189 		return;
8190 
8191 	netdev_hw_stats64_add(stats, p_stats);
8192 }
8193 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8194 
8195 /**
8196  * netdev_get_xmit_slave - Get the xmit slave of master device
8197  * @dev: device
8198  * @skb: The packet
8199  * @all_slaves: assume all the slaves are active
8200  *
8201  * The reference counters are not incremented so the caller must be
8202  * careful with locks. The caller must hold RCU lock.
8203  * %NULL is returned if no slave is found.
8204  */
8205 
8206 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8207 					 struct sk_buff *skb,
8208 					 bool all_slaves)
8209 {
8210 	const struct net_device_ops *ops = dev->netdev_ops;
8211 
8212 	if (!ops->ndo_get_xmit_slave)
8213 		return NULL;
8214 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8215 }
8216 EXPORT_SYMBOL(netdev_get_xmit_slave);
8217 
8218 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8219 						  struct sock *sk)
8220 {
8221 	const struct net_device_ops *ops = dev->netdev_ops;
8222 
8223 	if (!ops->ndo_sk_get_lower_dev)
8224 		return NULL;
8225 	return ops->ndo_sk_get_lower_dev(dev, sk);
8226 }
8227 
8228 /**
8229  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8230  * @dev: device
8231  * @sk: the socket
8232  *
8233  * %NULL is returned if no lower device is found.
8234  */
8235 
8236 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8237 					    struct sock *sk)
8238 {
8239 	struct net_device *lower;
8240 
8241 	lower = netdev_sk_get_lower_dev(dev, sk);
8242 	while (lower) {
8243 		dev = lower;
8244 		lower = netdev_sk_get_lower_dev(dev, sk);
8245 	}
8246 
8247 	return dev;
8248 }
8249 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8250 
8251 static void netdev_adjacent_add_links(struct net_device *dev)
8252 {
8253 	struct netdev_adjacent *iter;
8254 
8255 	struct net *net = dev_net(dev);
8256 
8257 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8258 		if (!net_eq(net, dev_net(iter->dev)))
8259 			continue;
8260 		netdev_adjacent_sysfs_add(iter->dev, dev,
8261 					  &iter->dev->adj_list.lower);
8262 		netdev_adjacent_sysfs_add(dev, iter->dev,
8263 					  &dev->adj_list.upper);
8264 	}
8265 
8266 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8267 		if (!net_eq(net, dev_net(iter->dev)))
8268 			continue;
8269 		netdev_adjacent_sysfs_add(iter->dev, dev,
8270 					  &iter->dev->adj_list.upper);
8271 		netdev_adjacent_sysfs_add(dev, iter->dev,
8272 					  &dev->adj_list.lower);
8273 	}
8274 }
8275 
8276 static void netdev_adjacent_del_links(struct net_device *dev)
8277 {
8278 	struct netdev_adjacent *iter;
8279 
8280 	struct net *net = dev_net(dev);
8281 
8282 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8283 		if (!net_eq(net, dev_net(iter->dev)))
8284 			continue;
8285 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8286 					  &iter->dev->adj_list.lower);
8287 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8288 					  &dev->adj_list.upper);
8289 	}
8290 
8291 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8292 		if (!net_eq(net, dev_net(iter->dev)))
8293 			continue;
8294 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8295 					  &iter->dev->adj_list.upper);
8296 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8297 					  &dev->adj_list.lower);
8298 	}
8299 }
8300 
8301 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8302 {
8303 	struct netdev_adjacent *iter;
8304 
8305 	struct net *net = dev_net(dev);
8306 
8307 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8308 		if (!net_eq(net, dev_net(iter->dev)))
8309 			continue;
8310 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8311 					  &iter->dev->adj_list.lower);
8312 		netdev_adjacent_sysfs_add(iter->dev, dev,
8313 					  &iter->dev->adj_list.lower);
8314 	}
8315 
8316 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8317 		if (!net_eq(net, dev_net(iter->dev)))
8318 			continue;
8319 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8320 					  &iter->dev->adj_list.upper);
8321 		netdev_adjacent_sysfs_add(iter->dev, dev,
8322 					  &iter->dev->adj_list.upper);
8323 	}
8324 }
8325 
8326 void *netdev_lower_dev_get_private(struct net_device *dev,
8327 				   struct net_device *lower_dev)
8328 {
8329 	struct netdev_adjacent *lower;
8330 
8331 	if (!lower_dev)
8332 		return NULL;
8333 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8334 	if (!lower)
8335 		return NULL;
8336 
8337 	return lower->private;
8338 }
8339 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8340 
8341 
8342 /**
8343  * netdev_lower_state_changed - Dispatch event about lower device state change
8344  * @lower_dev: device
8345  * @lower_state_info: state to dispatch
8346  *
8347  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8348  * The caller must hold the RTNL lock.
8349  */
8350 void netdev_lower_state_changed(struct net_device *lower_dev,
8351 				void *lower_state_info)
8352 {
8353 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8354 		.info.dev = lower_dev,
8355 	};
8356 
8357 	ASSERT_RTNL();
8358 	changelowerstate_info.lower_state_info = lower_state_info;
8359 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8360 				      &changelowerstate_info.info);
8361 }
8362 EXPORT_SYMBOL(netdev_lower_state_changed);
8363 
8364 static void dev_change_rx_flags(struct net_device *dev, int flags)
8365 {
8366 	const struct net_device_ops *ops = dev->netdev_ops;
8367 
8368 	if (ops->ndo_change_rx_flags)
8369 		ops->ndo_change_rx_flags(dev, flags);
8370 }
8371 
8372 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8373 {
8374 	unsigned int old_flags = dev->flags;
8375 	kuid_t uid;
8376 	kgid_t gid;
8377 
8378 	ASSERT_RTNL();
8379 
8380 	dev->flags |= IFF_PROMISC;
8381 	dev->promiscuity += inc;
8382 	if (dev->promiscuity == 0) {
8383 		/*
8384 		 * Avoid overflow.
8385 		 * If inc causes overflow, untouch promisc and return error.
8386 		 */
8387 		if (inc < 0)
8388 			dev->flags &= ~IFF_PROMISC;
8389 		else {
8390 			dev->promiscuity -= inc;
8391 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8392 			return -EOVERFLOW;
8393 		}
8394 	}
8395 	if (dev->flags != old_flags) {
8396 		netdev_info(dev, "%s promiscuous mode\n",
8397 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8398 		if (audit_enabled) {
8399 			current_uid_gid(&uid, &gid);
8400 			audit_log(audit_context(), GFP_ATOMIC,
8401 				  AUDIT_ANOM_PROMISCUOUS,
8402 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8403 				  dev->name, (dev->flags & IFF_PROMISC),
8404 				  (old_flags & IFF_PROMISC),
8405 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8406 				  from_kuid(&init_user_ns, uid),
8407 				  from_kgid(&init_user_ns, gid),
8408 				  audit_get_sessionid(current));
8409 		}
8410 
8411 		dev_change_rx_flags(dev, IFF_PROMISC);
8412 	}
8413 	if (notify)
8414 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8415 	return 0;
8416 }
8417 
8418 /**
8419  *	dev_set_promiscuity	- update promiscuity count on a device
8420  *	@dev: device
8421  *	@inc: modifier
8422  *
8423  *	Add or remove promiscuity from a device. While the count in the device
8424  *	remains above zero the interface remains promiscuous. Once it hits zero
8425  *	the device reverts back to normal filtering operation. A negative inc
8426  *	value is used to drop promiscuity on the device.
8427  *	Return 0 if successful or a negative errno code on error.
8428  */
8429 int dev_set_promiscuity(struct net_device *dev, int inc)
8430 {
8431 	unsigned int old_flags = dev->flags;
8432 	int err;
8433 
8434 	err = __dev_set_promiscuity(dev, inc, true);
8435 	if (err < 0)
8436 		return err;
8437 	if (dev->flags != old_flags)
8438 		dev_set_rx_mode(dev);
8439 	return err;
8440 }
8441 EXPORT_SYMBOL(dev_set_promiscuity);
8442 
8443 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8444 {
8445 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8446 
8447 	ASSERT_RTNL();
8448 
8449 	dev->flags |= IFF_ALLMULTI;
8450 	dev->allmulti += inc;
8451 	if (dev->allmulti == 0) {
8452 		/*
8453 		 * Avoid overflow.
8454 		 * If inc causes overflow, untouch allmulti and return error.
8455 		 */
8456 		if (inc < 0)
8457 			dev->flags &= ~IFF_ALLMULTI;
8458 		else {
8459 			dev->allmulti -= inc;
8460 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8461 			return -EOVERFLOW;
8462 		}
8463 	}
8464 	if (dev->flags ^ old_flags) {
8465 		netdev_info(dev, "%s allmulticast mode\n",
8466 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8467 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8468 		dev_set_rx_mode(dev);
8469 		if (notify)
8470 			__dev_notify_flags(dev, old_flags,
8471 					   dev->gflags ^ old_gflags, 0, NULL);
8472 	}
8473 	return 0;
8474 }
8475 
8476 /**
8477  *	dev_set_allmulti	- update allmulti count on a device
8478  *	@dev: device
8479  *	@inc: modifier
8480  *
8481  *	Add or remove reception of all multicast frames to a device. While the
8482  *	count in the device remains above zero the interface remains listening
8483  *	to all interfaces. Once it hits zero the device reverts back to normal
8484  *	filtering operation. A negative @inc value is used to drop the counter
8485  *	when releasing a resource needing all multicasts.
8486  *	Return 0 if successful or a negative errno code on error.
8487  */
8488 
8489 int dev_set_allmulti(struct net_device *dev, int inc)
8490 {
8491 	return __dev_set_allmulti(dev, inc, true);
8492 }
8493 EXPORT_SYMBOL(dev_set_allmulti);
8494 
8495 /*
8496  *	Upload unicast and multicast address lists to device and
8497  *	configure RX filtering. When the device doesn't support unicast
8498  *	filtering it is put in promiscuous mode while unicast addresses
8499  *	are present.
8500  */
8501 void __dev_set_rx_mode(struct net_device *dev)
8502 {
8503 	const struct net_device_ops *ops = dev->netdev_ops;
8504 
8505 	/* dev_open will call this function so the list will stay sane. */
8506 	if (!(dev->flags&IFF_UP))
8507 		return;
8508 
8509 	if (!netif_device_present(dev))
8510 		return;
8511 
8512 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8513 		/* Unicast addresses changes may only happen under the rtnl,
8514 		 * therefore calling __dev_set_promiscuity here is safe.
8515 		 */
8516 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8517 			__dev_set_promiscuity(dev, 1, false);
8518 			dev->uc_promisc = true;
8519 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8520 			__dev_set_promiscuity(dev, -1, false);
8521 			dev->uc_promisc = false;
8522 		}
8523 	}
8524 
8525 	if (ops->ndo_set_rx_mode)
8526 		ops->ndo_set_rx_mode(dev);
8527 }
8528 
8529 void dev_set_rx_mode(struct net_device *dev)
8530 {
8531 	netif_addr_lock_bh(dev);
8532 	__dev_set_rx_mode(dev);
8533 	netif_addr_unlock_bh(dev);
8534 }
8535 
8536 /**
8537  *	dev_get_flags - get flags reported to userspace
8538  *	@dev: device
8539  *
8540  *	Get the combination of flag bits exported through APIs to userspace.
8541  */
8542 unsigned int dev_get_flags(const struct net_device *dev)
8543 {
8544 	unsigned int flags;
8545 
8546 	flags = (dev->flags & ~(IFF_PROMISC |
8547 				IFF_ALLMULTI |
8548 				IFF_RUNNING |
8549 				IFF_LOWER_UP |
8550 				IFF_DORMANT)) |
8551 		(dev->gflags & (IFF_PROMISC |
8552 				IFF_ALLMULTI));
8553 
8554 	if (netif_running(dev)) {
8555 		if (netif_oper_up(dev))
8556 			flags |= IFF_RUNNING;
8557 		if (netif_carrier_ok(dev))
8558 			flags |= IFF_LOWER_UP;
8559 		if (netif_dormant(dev))
8560 			flags |= IFF_DORMANT;
8561 	}
8562 
8563 	return flags;
8564 }
8565 EXPORT_SYMBOL(dev_get_flags);
8566 
8567 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8568 		       struct netlink_ext_ack *extack)
8569 {
8570 	unsigned int old_flags = dev->flags;
8571 	int ret;
8572 
8573 	ASSERT_RTNL();
8574 
8575 	/*
8576 	 *	Set the flags on our device.
8577 	 */
8578 
8579 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8580 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8581 			       IFF_AUTOMEDIA)) |
8582 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8583 				    IFF_ALLMULTI));
8584 
8585 	/*
8586 	 *	Load in the correct multicast list now the flags have changed.
8587 	 */
8588 
8589 	if ((old_flags ^ flags) & IFF_MULTICAST)
8590 		dev_change_rx_flags(dev, IFF_MULTICAST);
8591 
8592 	dev_set_rx_mode(dev);
8593 
8594 	/*
8595 	 *	Have we downed the interface. We handle IFF_UP ourselves
8596 	 *	according to user attempts to set it, rather than blindly
8597 	 *	setting it.
8598 	 */
8599 
8600 	ret = 0;
8601 	if ((old_flags ^ flags) & IFF_UP) {
8602 		if (old_flags & IFF_UP)
8603 			__dev_close(dev);
8604 		else
8605 			ret = __dev_open(dev, extack);
8606 	}
8607 
8608 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8609 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8610 		unsigned int old_flags = dev->flags;
8611 
8612 		dev->gflags ^= IFF_PROMISC;
8613 
8614 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8615 			if (dev->flags != old_flags)
8616 				dev_set_rx_mode(dev);
8617 	}
8618 
8619 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8620 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8621 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8622 	 */
8623 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8624 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8625 
8626 		dev->gflags ^= IFF_ALLMULTI;
8627 		__dev_set_allmulti(dev, inc, false);
8628 	}
8629 
8630 	return ret;
8631 }
8632 
8633 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8634 			unsigned int gchanges, u32 portid,
8635 			const struct nlmsghdr *nlh)
8636 {
8637 	unsigned int changes = dev->flags ^ old_flags;
8638 
8639 	if (gchanges)
8640 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8641 
8642 	if (changes & IFF_UP) {
8643 		if (dev->flags & IFF_UP)
8644 			call_netdevice_notifiers(NETDEV_UP, dev);
8645 		else
8646 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8647 	}
8648 
8649 	if (dev->flags & IFF_UP &&
8650 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8651 		struct netdev_notifier_change_info change_info = {
8652 			.info = {
8653 				.dev = dev,
8654 			},
8655 			.flags_changed = changes,
8656 		};
8657 
8658 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8659 	}
8660 }
8661 
8662 /**
8663  *	dev_change_flags - change device settings
8664  *	@dev: device
8665  *	@flags: device state flags
8666  *	@extack: netlink extended ack
8667  *
8668  *	Change settings on device based state flags. The flags are
8669  *	in the userspace exported format.
8670  */
8671 int dev_change_flags(struct net_device *dev, unsigned int flags,
8672 		     struct netlink_ext_ack *extack)
8673 {
8674 	int ret;
8675 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8676 
8677 	ret = __dev_change_flags(dev, flags, extack);
8678 	if (ret < 0)
8679 		return ret;
8680 
8681 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8682 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8683 	return ret;
8684 }
8685 EXPORT_SYMBOL(dev_change_flags);
8686 
8687 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8688 {
8689 	const struct net_device_ops *ops = dev->netdev_ops;
8690 
8691 	if (ops->ndo_change_mtu)
8692 		return ops->ndo_change_mtu(dev, new_mtu);
8693 
8694 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8695 	WRITE_ONCE(dev->mtu, new_mtu);
8696 	return 0;
8697 }
8698 EXPORT_SYMBOL(__dev_set_mtu);
8699 
8700 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8701 		     struct netlink_ext_ack *extack)
8702 {
8703 	/* MTU must be positive, and in range */
8704 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8705 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8706 		return -EINVAL;
8707 	}
8708 
8709 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8710 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8711 		return -EINVAL;
8712 	}
8713 	return 0;
8714 }
8715 
8716 /**
8717  *	dev_set_mtu_ext - Change maximum transfer unit
8718  *	@dev: device
8719  *	@new_mtu: new transfer unit
8720  *	@extack: netlink extended ack
8721  *
8722  *	Change the maximum transfer size of the network device.
8723  */
8724 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8725 		    struct netlink_ext_ack *extack)
8726 {
8727 	int err, orig_mtu;
8728 
8729 	if (new_mtu == dev->mtu)
8730 		return 0;
8731 
8732 	err = dev_validate_mtu(dev, new_mtu, extack);
8733 	if (err)
8734 		return err;
8735 
8736 	if (!netif_device_present(dev))
8737 		return -ENODEV;
8738 
8739 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8740 	err = notifier_to_errno(err);
8741 	if (err)
8742 		return err;
8743 
8744 	orig_mtu = dev->mtu;
8745 	err = __dev_set_mtu(dev, new_mtu);
8746 
8747 	if (!err) {
8748 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8749 						   orig_mtu);
8750 		err = notifier_to_errno(err);
8751 		if (err) {
8752 			/* setting mtu back and notifying everyone again,
8753 			 * so that they have a chance to revert changes.
8754 			 */
8755 			__dev_set_mtu(dev, orig_mtu);
8756 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8757 						     new_mtu);
8758 		}
8759 	}
8760 	return err;
8761 }
8762 
8763 int dev_set_mtu(struct net_device *dev, int new_mtu)
8764 {
8765 	struct netlink_ext_ack extack;
8766 	int err;
8767 
8768 	memset(&extack, 0, sizeof(extack));
8769 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8770 	if (err && extack._msg)
8771 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8772 	return err;
8773 }
8774 EXPORT_SYMBOL(dev_set_mtu);
8775 
8776 /**
8777  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8778  *	@dev: device
8779  *	@new_len: new tx queue length
8780  */
8781 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8782 {
8783 	unsigned int orig_len = dev->tx_queue_len;
8784 	int res;
8785 
8786 	if (new_len != (unsigned int)new_len)
8787 		return -ERANGE;
8788 
8789 	if (new_len != orig_len) {
8790 		dev->tx_queue_len = new_len;
8791 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8792 		res = notifier_to_errno(res);
8793 		if (res)
8794 			goto err_rollback;
8795 		res = dev_qdisc_change_tx_queue_len(dev);
8796 		if (res)
8797 			goto err_rollback;
8798 	}
8799 
8800 	return 0;
8801 
8802 err_rollback:
8803 	netdev_err(dev, "refused to change device tx_queue_len\n");
8804 	dev->tx_queue_len = orig_len;
8805 	return res;
8806 }
8807 
8808 /**
8809  *	dev_set_group - Change group this device belongs to
8810  *	@dev: device
8811  *	@new_group: group this device should belong to
8812  */
8813 void dev_set_group(struct net_device *dev, int new_group)
8814 {
8815 	dev->group = new_group;
8816 }
8817 
8818 /**
8819  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8820  *	@dev: device
8821  *	@addr: new address
8822  *	@extack: netlink extended ack
8823  */
8824 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8825 			      struct netlink_ext_ack *extack)
8826 {
8827 	struct netdev_notifier_pre_changeaddr_info info = {
8828 		.info.dev = dev,
8829 		.info.extack = extack,
8830 		.dev_addr = addr,
8831 	};
8832 	int rc;
8833 
8834 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8835 	return notifier_to_errno(rc);
8836 }
8837 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8838 
8839 /**
8840  *	dev_set_mac_address - Change Media Access Control Address
8841  *	@dev: device
8842  *	@sa: new address
8843  *	@extack: netlink extended ack
8844  *
8845  *	Change the hardware (MAC) address of the device
8846  */
8847 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8848 			struct netlink_ext_ack *extack)
8849 {
8850 	const struct net_device_ops *ops = dev->netdev_ops;
8851 	int err;
8852 
8853 	if (!ops->ndo_set_mac_address)
8854 		return -EOPNOTSUPP;
8855 	if (sa->sa_family != dev->type)
8856 		return -EINVAL;
8857 	if (!netif_device_present(dev))
8858 		return -ENODEV;
8859 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8860 	if (err)
8861 		return err;
8862 	if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
8863 		err = ops->ndo_set_mac_address(dev, sa);
8864 		if (err)
8865 			return err;
8866 	}
8867 	dev->addr_assign_type = NET_ADDR_SET;
8868 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8869 	add_device_randomness(dev->dev_addr, dev->addr_len);
8870 	return 0;
8871 }
8872 EXPORT_SYMBOL(dev_set_mac_address);
8873 
8874 static DECLARE_RWSEM(dev_addr_sem);
8875 
8876 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8877 			     struct netlink_ext_ack *extack)
8878 {
8879 	int ret;
8880 
8881 	down_write(&dev_addr_sem);
8882 	ret = dev_set_mac_address(dev, sa, extack);
8883 	up_write(&dev_addr_sem);
8884 	return ret;
8885 }
8886 EXPORT_SYMBOL(dev_set_mac_address_user);
8887 
8888 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8889 {
8890 	size_t size = sizeof(sa->sa_data_min);
8891 	struct net_device *dev;
8892 	int ret = 0;
8893 
8894 	down_read(&dev_addr_sem);
8895 	rcu_read_lock();
8896 
8897 	dev = dev_get_by_name_rcu(net, dev_name);
8898 	if (!dev) {
8899 		ret = -ENODEV;
8900 		goto unlock;
8901 	}
8902 	if (!dev->addr_len)
8903 		memset(sa->sa_data, 0, size);
8904 	else
8905 		memcpy(sa->sa_data, dev->dev_addr,
8906 		       min_t(size_t, size, dev->addr_len));
8907 	sa->sa_family = dev->type;
8908 
8909 unlock:
8910 	rcu_read_unlock();
8911 	up_read(&dev_addr_sem);
8912 	return ret;
8913 }
8914 EXPORT_SYMBOL(dev_get_mac_address);
8915 
8916 /**
8917  *	dev_change_carrier - Change device carrier
8918  *	@dev: device
8919  *	@new_carrier: new value
8920  *
8921  *	Change device carrier
8922  */
8923 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8924 {
8925 	const struct net_device_ops *ops = dev->netdev_ops;
8926 
8927 	if (!ops->ndo_change_carrier)
8928 		return -EOPNOTSUPP;
8929 	if (!netif_device_present(dev))
8930 		return -ENODEV;
8931 	return ops->ndo_change_carrier(dev, new_carrier);
8932 }
8933 
8934 /**
8935  *	dev_get_phys_port_id - Get device physical port ID
8936  *	@dev: device
8937  *	@ppid: port ID
8938  *
8939  *	Get device physical port ID
8940  */
8941 int dev_get_phys_port_id(struct net_device *dev,
8942 			 struct netdev_phys_item_id *ppid)
8943 {
8944 	const struct net_device_ops *ops = dev->netdev_ops;
8945 
8946 	if (!ops->ndo_get_phys_port_id)
8947 		return -EOPNOTSUPP;
8948 	return ops->ndo_get_phys_port_id(dev, ppid);
8949 }
8950 
8951 /**
8952  *	dev_get_phys_port_name - Get device physical port name
8953  *	@dev: device
8954  *	@name: port name
8955  *	@len: limit of bytes to copy to name
8956  *
8957  *	Get device physical port name
8958  */
8959 int dev_get_phys_port_name(struct net_device *dev,
8960 			   char *name, size_t len)
8961 {
8962 	const struct net_device_ops *ops = dev->netdev_ops;
8963 	int err;
8964 
8965 	if (ops->ndo_get_phys_port_name) {
8966 		err = ops->ndo_get_phys_port_name(dev, name, len);
8967 		if (err != -EOPNOTSUPP)
8968 			return err;
8969 	}
8970 	return devlink_compat_phys_port_name_get(dev, name, len);
8971 }
8972 
8973 /**
8974  *	dev_get_port_parent_id - Get the device's port parent identifier
8975  *	@dev: network device
8976  *	@ppid: pointer to a storage for the port's parent identifier
8977  *	@recurse: allow/disallow recursion to lower devices
8978  *
8979  *	Get the devices's port parent identifier
8980  */
8981 int dev_get_port_parent_id(struct net_device *dev,
8982 			   struct netdev_phys_item_id *ppid,
8983 			   bool recurse)
8984 {
8985 	const struct net_device_ops *ops = dev->netdev_ops;
8986 	struct netdev_phys_item_id first = { };
8987 	struct net_device *lower_dev;
8988 	struct list_head *iter;
8989 	int err;
8990 
8991 	if (ops->ndo_get_port_parent_id) {
8992 		err = ops->ndo_get_port_parent_id(dev, ppid);
8993 		if (err != -EOPNOTSUPP)
8994 			return err;
8995 	}
8996 
8997 	err = devlink_compat_switch_id_get(dev, ppid);
8998 	if (!recurse || err != -EOPNOTSUPP)
8999 		return err;
9000 
9001 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
9002 		err = dev_get_port_parent_id(lower_dev, ppid, true);
9003 		if (err)
9004 			break;
9005 		if (!first.id_len)
9006 			first = *ppid;
9007 		else if (memcmp(&first, ppid, sizeof(*ppid)))
9008 			return -EOPNOTSUPP;
9009 	}
9010 
9011 	return err;
9012 }
9013 EXPORT_SYMBOL(dev_get_port_parent_id);
9014 
9015 /**
9016  *	netdev_port_same_parent_id - Indicate if two network devices have
9017  *	the same port parent identifier
9018  *	@a: first network device
9019  *	@b: second network device
9020  */
9021 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
9022 {
9023 	struct netdev_phys_item_id a_id = { };
9024 	struct netdev_phys_item_id b_id = { };
9025 
9026 	if (dev_get_port_parent_id(a, &a_id, true) ||
9027 	    dev_get_port_parent_id(b, &b_id, true))
9028 		return false;
9029 
9030 	return netdev_phys_item_id_same(&a_id, &b_id);
9031 }
9032 EXPORT_SYMBOL(netdev_port_same_parent_id);
9033 
9034 static void netdev_dpll_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
9035 {
9036 #if IS_ENABLED(CONFIG_DPLL)
9037 	rtnl_lock();
9038 	dev->dpll_pin = dpll_pin;
9039 	rtnl_unlock();
9040 #endif
9041 }
9042 
9043 void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
9044 {
9045 	WARN_ON(!dpll_pin);
9046 	netdev_dpll_pin_assign(dev, dpll_pin);
9047 }
9048 EXPORT_SYMBOL(netdev_dpll_pin_set);
9049 
9050 void netdev_dpll_pin_clear(struct net_device *dev)
9051 {
9052 	netdev_dpll_pin_assign(dev, NULL);
9053 }
9054 EXPORT_SYMBOL(netdev_dpll_pin_clear);
9055 
9056 /**
9057  *	dev_change_proto_down - set carrier according to proto_down.
9058  *
9059  *	@dev: device
9060  *	@proto_down: new value
9061  */
9062 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9063 {
9064 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
9065 		return -EOPNOTSUPP;
9066 	if (!netif_device_present(dev))
9067 		return -ENODEV;
9068 	if (proto_down)
9069 		netif_carrier_off(dev);
9070 	else
9071 		netif_carrier_on(dev);
9072 	dev->proto_down = proto_down;
9073 	return 0;
9074 }
9075 
9076 /**
9077  *	dev_change_proto_down_reason - proto down reason
9078  *
9079  *	@dev: device
9080  *	@mask: proto down mask
9081  *	@value: proto down value
9082  */
9083 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9084 				  u32 value)
9085 {
9086 	int b;
9087 
9088 	if (!mask) {
9089 		dev->proto_down_reason = value;
9090 	} else {
9091 		for_each_set_bit(b, &mask, 32) {
9092 			if (value & (1 << b))
9093 				dev->proto_down_reason |= BIT(b);
9094 			else
9095 				dev->proto_down_reason &= ~BIT(b);
9096 		}
9097 	}
9098 }
9099 
9100 struct bpf_xdp_link {
9101 	struct bpf_link link;
9102 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9103 	int flags;
9104 };
9105 
9106 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9107 {
9108 	if (flags & XDP_FLAGS_HW_MODE)
9109 		return XDP_MODE_HW;
9110 	if (flags & XDP_FLAGS_DRV_MODE)
9111 		return XDP_MODE_DRV;
9112 	if (flags & XDP_FLAGS_SKB_MODE)
9113 		return XDP_MODE_SKB;
9114 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9115 }
9116 
9117 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9118 {
9119 	switch (mode) {
9120 	case XDP_MODE_SKB:
9121 		return generic_xdp_install;
9122 	case XDP_MODE_DRV:
9123 	case XDP_MODE_HW:
9124 		return dev->netdev_ops->ndo_bpf;
9125 	default:
9126 		return NULL;
9127 	}
9128 }
9129 
9130 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9131 					 enum bpf_xdp_mode mode)
9132 {
9133 	return dev->xdp_state[mode].link;
9134 }
9135 
9136 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9137 				     enum bpf_xdp_mode mode)
9138 {
9139 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9140 
9141 	if (link)
9142 		return link->link.prog;
9143 	return dev->xdp_state[mode].prog;
9144 }
9145 
9146 u8 dev_xdp_prog_count(struct net_device *dev)
9147 {
9148 	u8 count = 0;
9149 	int i;
9150 
9151 	for (i = 0; i < __MAX_XDP_MODE; i++)
9152 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9153 			count++;
9154 	return count;
9155 }
9156 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9157 
9158 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9159 {
9160 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9161 
9162 	return prog ? prog->aux->id : 0;
9163 }
9164 
9165 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9166 			     struct bpf_xdp_link *link)
9167 {
9168 	dev->xdp_state[mode].link = link;
9169 	dev->xdp_state[mode].prog = NULL;
9170 }
9171 
9172 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9173 			     struct bpf_prog *prog)
9174 {
9175 	dev->xdp_state[mode].link = NULL;
9176 	dev->xdp_state[mode].prog = prog;
9177 }
9178 
9179 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9180 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9181 			   u32 flags, struct bpf_prog *prog)
9182 {
9183 	struct netdev_bpf xdp;
9184 	int err;
9185 
9186 	memset(&xdp, 0, sizeof(xdp));
9187 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9188 	xdp.extack = extack;
9189 	xdp.flags = flags;
9190 	xdp.prog = prog;
9191 
9192 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9193 	 * "moved" into driver), so they don't increment it on their own, but
9194 	 * they do decrement refcnt when program is detached or replaced.
9195 	 * Given net_device also owns link/prog, we need to bump refcnt here
9196 	 * to prevent drivers from underflowing it.
9197 	 */
9198 	if (prog)
9199 		bpf_prog_inc(prog);
9200 	err = bpf_op(dev, &xdp);
9201 	if (err) {
9202 		if (prog)
9203 			bpf_prog_put(prog);
9204 		return err;
9205 	}
9206 
9207 	if (mode != XDP_MODE_HW)
9208 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9209 
9210 	return 0;
9211 }
9212 
9213 static void dev_xdp_uninstall(struct net_device *dev)
9214 {
9215 	struct bpf_xdp_link *link;
9216 	struct bpf_prog *prog;
9217 	enum bpf_xdp_mode mode;
9218 	bpf_op_t bpf_op;
9219 
9220 	ASSERT_RTNL();
9221 
9222 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9223 		prog = dev_xdp_prog(dev, mode);
9224 		if (!prog)
9225 			continue;
9226 
9227 		bpf_op = dev_xdp_bpf_op(dev, mode);
9228 		if (!bpf_op)
9229 			continue;
9230 
9231 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9232 
9233 		/* auto-detach link from net device */
9234 		link = dev_xdp_link(dev, mode);
9235 		if (link)
9236 			link->dev = NULL;
9237 		else
9238 			bpf_prog_put(prog);
9239 
9240 		dev_xdp_set_link(dev, mode, NULL);
9241 	}
9242 }
9243 
9244 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9245 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9246 			  struct bpf_prog *old_prog, u32 flags)
9247 {
9248 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9249 	struct bpf_prog *cur_prog;
9250 	struct net_device *upper;
9251 	struct list_head *iter;
9252 	enum bpf_xdp_mode mode;
9253 	bpf_op_t bpf_op;
9254 	int err;
9255 
9256 	ASSERT_RTNL();
9257 
9258 	/* either link or prog attachment, never both */
9259 	if (link && (new_prog || old_prog))
9260 		return -EINVAL;
9261 	/* link supports only XDP mode flags */
9262 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9263 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9264 		return -EINVAL;
9265 	}
9266 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9267 	if (num_modes > 1) {
9268 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9269 		return -EINVAL;
9270 	}
9271 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9272 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9273 		NL_SET_ERR_MSG(extack,
9274 			       "More than one program loaded, unset mode is ambiguous");
9275 		return -EINVAL;
9276 	}
9277 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9278 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9279 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9280 		return -EINVAL;
9281 	}
9282 
9283 	mode = dev_xdp_mode(dev, flags);
9284 	/* can't replace attached link */
9285 	if (dev_xdp_link(dev, mode)) {
9286 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9287 		return -EBUSY;
9288 	}
9289 
9290 	/* don't allow if an upper device already has a program */
9291 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9292 		if (dev_xdp_prog_count(upper) > 0) {
9293 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9294 			return -EEXIST;
9295 		}
9296 	}
9297 
9298 	cur_prog = dev_xdp_prog(dev, mode);
9299 	/* can't replace attached prog with link */
9300 	if (link && cur_prog) {
9301 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9302 		return -EBUSY;
9303 	}
9304 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9305 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9306 		return -EEXIST;
9307 	}
9308 
9309 	/* put effective new program into new_prog */
9310 	if (link)
9311 		new_prog = link->link.prog;
9312 
9313 	if (new_prog) {
9314 		bool offload = mode == XDP_MODE_HW;
9315 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9316 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9317 
9318 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9319 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9320 			return -EBUSY;
9321 		}
9322 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9323 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9324 			return -EEXIST;
9325 		}
9326 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9327 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9328 			return -EINVAL;
9329 		}
9330 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9331 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9332 			return -EINVAL;
9333 		}
9334 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9335 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9336 			return -EINVAL;
9337 		}
9338 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9339 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9340 			return -EINVAL;
9341 		}
9342 	}
9343 
9344 	/* don't call drivers if the effective program didn't change */
9345 	if (new_prog != cur_prog) {
9346 		bpf_op = dev_xdp_bpf_op(dev, mode);
9347 		if (!bpf_op) {
9348 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9349 			return -EOPNOTSUPP;
9350 		}
9351 
9352 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9353 		if (err)
9354 			return err;
9355 	}
9356 
9357 	if (link)
9358 		dev_xdp_set_link(dev, mode, link);
9359 	else
9360 		dev_xdp_set_prog(dev, mode, new_prog);
9361 	if (cur_prog)
9362 		bpf_prog_put(cur_prog);
9363 
9364 	return 0;
9365 }
9366 
9367 static int dev_xdp_attach_link(struct net_device *dev,
9368 			       struct netlink_ext_ack *extack,
9369 			       struct bpf_xdp_link *link)
9370 {
9371 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9372 }
9373 
9374 static int dev_xdp_detach_link(struct net_device *dev,
9375 			       struct netlink_ext_ack *extack,
9376 			       struct bpf_xdp_link *link)
9377 {
9378 	enum bpf_xdp_mode mode;
9379 	bpf_op_t bpf_op;
9380 
9381 	ASSERT_RTNL();
9382 
9383 	mode = dev_xdp_mode(dev, link->flags);
9384 	if (dev_xdp_link(dev, mode) != link)
9385 		return -EINVAL;
9386 
9387 	bpf_op = dev_xdp_bpf_op(dev, mode);
9388 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9389 	dev_xdp_set_link(dev, mode, NULL);
9390 	return 0;
9391 }
9392 
9393 static void bpf_xdp_link_release(struct bpf_link *link)
9394 {
9395 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9396 
9397 	rtnl_lock();
9398 
9399 	/* if racing with net_device's tear down, xdp_link->dev might be
9400 	 * already NULL, in which case link was already auto-detached
9401 	 */
9402 	if (xdp_link->dev) {
9403 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9404 		xdp_link->dev = NULL;
9405 	}
9406 
9407 	rtnl_unlock();
9408 }
9409 
9410 static int bpf_xdp_link_detach(struct bpf_link *link)
9411 {
9412 	bpf_xdp_link_release(link);
9413 	return 0;
9414 }
9415 
9416 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9417 {
9418 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9419 
9420 	kfree(xdp_link);
9421 }
9422 
9423 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9424 				     struct seq_file *seq)
9425 {
9426 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9427 	u32 ifindex = 0;
9428 
9429 	rtnl_lock();
9430 	if (xdp_link->dev)
9431 		ifindex = xdp_link->dev->ifindex;
9432 	rtnl_unlock();
9433 
9434 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9435 }
9436 
9437 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9438 				       struct bpf_link_info *info)
9439 {
9440 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9441 	u32 ifindex = 0;
9442 
9443 	rtnl_lock();
9444 	if (xdp_link->dev)
9445 		ifindex = xdp_link->dev->ifindex;
9446 	rtnl_unlock();
9447 
9448 	info->xdp.ifindex = ifindex;
9449 	return 0;
9450 }
9451 
9452 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9453 			       struct bpf_prog *old_prog)
9454 {
9455 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9456 	enum bpf_xdp_mode mode;
9457 	bpf_op_t bpf_op;
9458 	int err = 0;
9459 
9460 	rtnl_lock();
9461 
9462 	/* link might have been auto-released already, so fail */
9463 	if (!xdp_link->dev) {
9464 		err = -ENOLINK;
9465 		goto out_unlock;
9466 	}
9467 
9468 	if (old_prog && link->prog != old_prog) {
9469 		err = -EPERM;
9470 		goto out_unlock;
9471 	}
9472 	old_prog = link->prog;
9473 	if (old_prog->type != new_prog->type ||
9474 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9475 		err = -EINVAL;
9476 		goto out_unlock;
9477 	}
9478 
9479 	if (old_prog == new_prog) {
9480 		/* no-op, don't disturb drivers */
9481 		bpf_prog_put(new_prog);
9482 		goto out_unlock;
9483 	}
9484 
9485 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9486 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9487 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9488 			      xdp_link->flags, new_prog);
9489 	if (err)
9490 		goto out_unlock;
9491 
9492 	old_prog = xchg(&link->prog, new_prog);
9493 	bpf_prog_put(old_prog);
9494 
9495 out_unlock:
9496 	rtnl_unlock();
9497 	return err;
9498 }
9499 
9500 static const struct bpf_link_ops bpf_xdp_link_lops = {
9501 	.release = bpf_xdp_link_release,
9502 	.dealloc = bpf_xdp_link_dealloc,
9503 	.detach = bpf_xdp_link_detach,
9504 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9505 	.fill_link_info = bpf_xdp_link_fill_link_info,
9506 	.update_prog = bpf_xdp_link_update,
9507 };
9508 
9509 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9510 {
9511 	struct net *net = current->nsproxy->net_ns;
9512 	struct bpf_link_primer link_primer;
9513 	struct netlink_ext_ack extack = {};
9514 	struct bpf_xdp_link *link;
9515 	struct net_device *dev;
9516 	int err, fd;
9517 
9518 	rtnl_lock();
9519 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9520 	if (!dev) {
9521 		rtnl_unlock();
9522 		return -EINVAL;
9523 	}
9524 
9525 	link = kzalloc(sizeof(*link), GFP_USER);
9526 	if (!link) {
9527 		err = -ENOMEM;
9528 		goto unlock;
9529 	}
9530 
9531 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9532 	link->dev = dev;
9533 	link->flags = attr->link_create.flags;
9534 
9535 	err = bpf_link_prime(&link->link, &link_primer);
9536 	if (err) {
9537 		kfree(link);
9538 		goto unlock;
9539 	}
9540 
9541 	err = dev_xdp_attach_link(dev, &extack, link);
9542 	rtnl_unlock();
9543 
9544 	if (err) {
9545 		link->dev = NULL;
9546 		bpf_link_cleanup(&link_primer);
9547 		trace_bpf_xdp_link_attach_failed(extack._msg);
9548 		goto out_put_dev;
9549 	}
9550 
9551 	fd = bpf_link_settle(&link_primer);
9552 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9553 	dev_put(dev);
9554 	return fd;
9555 
9556 unlock:
9557 	rtnl_unlock();
9558 
9559 out_put_dev:
9560 	dev_put(dev);
9561 	return err;
9562 }
9563 
9564 /**
9565  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9566  *	@dev: device
9567  *	@extack: netlink extended ack
9568  *	@fd: new program fd or negative value to clear
9569  *	@expected_fd: old program fd that userspace expects to replace or clear
9570  *	@flags: xdp-related flags
9571  *
9572  *	Set or clear a bpf program for a device
9573  */
9574 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9575 		      int fd, int expected_fd, u32 flags)
9576 {
9577 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9578 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9579 	int err;
9580 
9581 	ASSERT_RTNL();
9582 
9583 	if (fd >= 0) {
9584 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9585 						 mode != XDP_MODE_SKB);
9586 		if (IS_ERR(new_prog))
9587 			return PTR_ERR(new_prog);
9588 	}
9589 
9590 	if (expected_fd >= 0) {
9591 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9592 						 mode != XDP_MODE_SKB);
9593 		if (IS_ERR(old_prog)) {
9594 			err = PTR_ERR(old_prog);
9595 			old_prog = NULL;
9596 			goto err_out;
9597 		}
9598 	}
9599 
9600 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9601 
9602 err_out:
9603 	if (err && new_prog)
9604 		bpf_prog_put(new_prog);
9605 	if (old_prog)
9606 		bpf_prog_put(old_prog);
9607 	return err;
9608 }
9609 
9610 /**
9611  * dev_index_reserve() - allocate an ifindex in a namespace
9612  * @net: the applicable net namespace
9613  * @ifindex: requested ifindex, pass %0 to get one allocated
9614  *
9615  * Allocate a ifindex for a new device. Caller must either use the ifindex
9616  * to store the device (via list_netdevice()) or call dev_index_release()
9617  * to give the index up.
9618  *
9619  * Return: a suitable unique value for a new device interface number or -errno.
9620  */
9621 static int dev_index_reserve(struct net *net, u32 ifindex)
9622 {
9623 	int err;
9624 
9625 	if (ifindex > INT_MAX) {
9626 		DEBUG_NET_WARN_ON_ONCE(1);
9627 		return -EINVAL;
9628 	}
9629 
9630 	if (!ifindex)
9631 		err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
9632 				      xa_limit_31b, &net->ifindex, GFP_KERNEL);
9633 	else
9634 		err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
9635 	if (err < 0)
9636 		return err;
9637 
9638 	return ifindex;
9639 }
9640 
9641 static void dev_index_release(struct net *net, int ifindex)
9642 {
9643 	/* Expect only unused indexes, unlist_netdevice() removes the used */
9644 	WARN_ON(xa_erase(&net->dev_by_index, ifindex));
9645 }
9646 
9647 /* Delayed registration/unregisteration */
9648 LIST_HEAD(net_todo_list);
9649 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9650 
9651 static void net_set_todo(struct net_device *dev)
9652 {
9653 	list_add_tail(&dev->todo_list, &net_todo_list);
9654 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9655 }
9656 
9657 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9658 	struct net_device *upper, netdev_features_t features)
9659 {
9660 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9661 	netdev_features_t feature;
9662 	int feature_bit;
9663 
9664 	for_each_netdev_feature(upper_disables, feature_bit) {
9665 		feature = __NETIF_F_BIT(feature_bit);
9666 		if (!(upper->wanted_features & feature)
9667 		    && (features & feature)) {
9668 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9669 				   &feature, upper->name);
9670 			features &= ~feature;
9671 		}
9672 	}
9673 
9674 	return features;
9675 }
9676 
9677 static void netdev_sync_lower_features(struct net_device *upper,
9678 	struct net_device *lower, netdev_features_t features)
9679 {
9680 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9681 	netdev_features_t feature;
9682 	int feature_bit;
9683 
9684 	for_each_netdev_feature(upper_disables, feature_bit) {
9685 		feature = __NETIF_F_BIT(feature_bit);
9686 		if (!(features & feature) && (lower->features & feature)) {
9687 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9688 				   &feature, lower->name);
9689 			lower->wanted_features &= ~feature;
9690 			__netdev_update_features(lower);
9691 
9692 			if (unlikely(lower->features & feature))
9693 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9694 					    &feature, lower->name);
9695 			else
9696 				netdev_features_change(lower);
9697 		}
9698 	}
9699 }
9700 
9701 static netdev_features_t netdev_fix_features(struct net_device *dev,
9702 	netdev_features_t features)
9703 {
9704 	/* Fix illegal checksum combinations */
9705 	if ((features & NETIF_F_HW_CSUM) &&
9706 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9707 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9708 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9709 	}
9710 
9711 	/* TSO requires that SG is present as well. */
9712 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9713 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9714 		features &= ~NETIF_F_ALL_TSO;
9715 	}
9716 
9717 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9718 					!(features & NETIF_F_IP_CSUM)) {
9719 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9720 		features &= ~NETIF_F_TSO;
9721 		features &= ~NETIF_F_TSO_ECN;
9722 	}
9723 
9724 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9725 					 !(features & NETIF_F_IPV6_CSUM)) {
9726 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9727 		features &= ~NETIF_F_TSO6;
9728 	}
9729 
9730 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9731 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9732 		features &= ~NETIF_F_TSO_MANGLEID;
9733 
9734 	/* TSO ECN requires that TSO is present as well. */
9735 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9736 		features &= ~NETIF_F_TSO_ECN;
9737 
9738 	/* Software GSO depends on SG. */
9739 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9740 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9741 		features &= ~NETIF_F_GSO;
9742 	}
9743 
9744 	/* GSO partial features require GSO partial be set */
9745 	if ((features & dev->gso_partial_features) &&
9746 	    !(features & NETIF_F_GSO_PARTIAL)) {
9747 		netdev_dbg(dev,
9748 			   "Dropping partially supported GSO features since no GSO partial.\n");
9749 		features &= ~dev->gso_partial_features;
9750 	}
9751 
9752 	if (!(features & NETIF_F_RXCSUM)) {
9753 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9754 		 * successfully merged by hardware must also have the
9755 		 * checksum verified by hardware.  If the user does not
9756 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9757 		 */
9758 		if (features & NETIF_F_GRO_HW) {
9759 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9760 			features &= ~NETIF_F_GRO_HW;
9761 		}
9762 	}
9763 
9764 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9765 	if (features & NETIF_F_RXFCS) {
9766 		if (features & NETIF_F_LRO) {
9767 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9768 			features &= ~NETIF_F_LRO;
9769 		}
9770 
9771 		if (features & NETIF_F_GRO_HW) {
9772 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9773 			features &= ~NETIF_F_GRO_HW;
9774 		}
9775 	}
9776 
9777 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9778 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9779 		features &= ~NETIF_F_LRO;
9780 	}
9781 
9782 	if (features & NETIF_F_HW_TLS_TX) {
9783 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9784 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9785 		bool hw_csum = features & NETIF_F_HW_CSUM;
9786 
9787 		if (!ip_csum && !hw_csum) {
9788 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9789 			features &= ~NETIF_F_HW_TLS_TX;
9790 		}
9791 	}
9792 
9793 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9794 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9795 		features &= ~NETIF_F_HW_TLS_RX;
9796 	}
9797 
9798 	return features;
9799 }
9800 
9801 int __netdev_update_features(struct net_device *dev)
9802 {
9803 	struct net_device *upper, *lower;
9804 	netdev_features_t features;
9805 	struct list_head *iter;
9806 	int err = -1;
9807 
9808 	ASSERT_RTNL();
9809 
9810 	features = netdev_get_wanted_features(dev);
9811 
9812 	if (dev->netdev_ops->ndo_fix_features)
9813 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9814 
9815 	/* driver might be less strict about feature dependencies */
9816 	features = netdev_fix_features(dev, features);
9817 
9818 	/* some features can't be enabled if they're off on an upper device */
9819 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9820 		features = netdev_sync_upper_features(dev, upper, features);
9821 
9822 	if (dev->features == features)
9823 		goto sync_lower;
9824 
9825 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9826 		&dev->features, &features);
9827 
9828 	if (dev->netdev_ops->ndo_set_features)
9829 		err = dev->netdev_ops->ndo_set_features(dev, features);
9830 	else
9831 		err = 0;
9832 
9833 	if (unlikely(err < 0)) {
9834 		netdev_err(dev,
9835 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9836 			err, &features, &dev->features);
9837 		/* return non-0 since some features might have changed and
9838 		 * it's better to fire a spurious notification than miss it
9839 		 */
9840 		return -1;
9841 	}
9842 
9843 sync_lower:
9844 	/* some features must be disabled on lower devices when disabled
9845 	 * on an upper device (think: bonding master or bridge)
9846 	 */
9847 	netdev_for_each_lower_dev(dev, lower, iter)
9848 		netdev_sync_lower_features(dev, lower, features);
9849 
9850 	if (!err) {
9851 		netdev_features_t diff = features ^ dev->features;
9852 
9853 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9854 			/* udp_tunnel_{get,drop}_rx_info both need
9855 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9856 			 * device, or they won't do anything.
9857 			 * Thus we need to update dev->features
9858 			 * *before* calling udp_tunnel_get_rx_info,
9859 			 * but *after* calling udp_tunnel_drop_rx_info.
9860 			 */
9861 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9862 				dev->features = features;
9863 				udp_tunnel_get_rx_info(dev);
9864 			} else {
9865 				udp_tunnel_drop_rx_info(dev);
9866 			}
9867 		}
9868 
9869 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9870 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9871 				dev->features = features;
9872 				err |= vlan_get_rx_ctag_filter_info(dev);
9873 			} else {
9874 				vlan_drop_rx_ctag_filter_info(dev);
9875 			}
9876 		}
9877 
9878 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9879 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9880 				dev->features = features;
9881 				err |= vlan_get_rx_stag_filter_info(dev);
9882 			} else {
9883 				vlan_drop_rx_stag_filter_info(dev);
9884 			}
9885 		}
9886 
9887 		dev->features = features;
9888 	}
9889 
9890 	return err < 0 ? 0 : 1;
9891 }
9892 
9893 /**
9894  *	netdev_update_features - recalculate device features
9895  *	@dev: the device to check
9896  *
9897  *	Recalculate dev->features set and send notifications if it
9898  *	has changed. Should be called after driver or hardware dependent
9899  *	conditions might have changed that influence the features.
9900  */
9901 void netdev_update_features(struct net_device *dev)
9902 {
9903 	if (__netdev_update_features(dev))
9904 		netdev_features_change(dev);
9905 }
9906 EXPORT_SYMBOL(netdev_update_features);
9907 
9908 /**
9909  *	netdev_change_features - recalculate device features
9910  *	@dev: the device to check
9911  *
9912  *	Recalculate dev->features set and send notifications even
9913  *	if they have not changed. Should be called instead of
9914  *	netdev_update_features() if also dev->vlan_features might
9915  *	have changed to allow the changes to be propagated to stacked
9916  *	VLAN devices.
9917  */
9918 void netdev_change_features(struct net_device *dev)
9919 {
9920 	__netdev_update_features(dev);
9921 	netdev_features_change(dev);
9922 }
9923 EXPORT_SYMBOL(netdev_change_features);
9924 
9925 /**
9926  *	netif_stacked_transfer_operstate -	transfer operstate
9927  *	@rootdev: the root or lower level device to transfer state from
9928  *	@dev: the device to transfer operstate to
9929  *
9930  *	Transfer operational state from root to device. This is normally
9931  *	called when a stacking relationship exists between the root
9932  *	device and the device(a leaf device).
9933  */
9934 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9935 					struct net_device *dev)
9936 {
9937 	if (rootdev->operstate == IF_OPER_DORMANT)
9938 		netif_dormant_on(dev);
9939 	else
9940 		netif_dormant_off(dev);
9941 
9942 	if (rootdev->operstate == IF_OPER_TESTING)
9943 		netif_testing_on(dev);
9944 	else
9945 		netif_testing_off(dev);
9946 
9947 	if (netif_carrier_ok(rootdev))
9948 		netif_carrier_on(dev);
9949 	else
9950 		netif_carrier_off(dev);
9951 }
9952 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9953 
9954 static int netif_alloc_rx_queues(struct net_device *dev)
9955 {
9956 	unsigned int i, count = dev->num_rx_queues;
9957 	struct netdev_rx_queue *rx;
9958 	size_t sz = count * sizeof(*rx);
9959 	int err = 0;
9960 
9961 	BUG_ON(count < 1);
9962 
9963 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9964 	if (!rx)
9965 		return -ENOMEM;
9966 
9967 	dev->_rx = rx;
9968 
9969 	for (i = 0; i < count; i++) {
9970 		rx[i].dev = dev;
9971 
9972 		/* XDP RX-queue setup */
9973 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9974 		if (err < 0)
9975 			goto err_rxq_info;
9976 	}
9977 	return 0;
9978 
9979 err_rxq_info:
9980 	/* Rollback successful reg's and free other resources */
9981 	while (i--)
9982 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9983 	kvfree(dev->_rx);
9984 	dev->_rx = NULL;
9985 	return err;
9986 }
9987 
9988 static void netif_free_rx_queues(struct net_device *dev)
9989 {
9990 	unsigned int i, count = dev->num_rx_queues;
9991 
9992 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9993 	if (!dev->_rx)
9994 		return;
9995 
9996 	for (i = 0; i < count; i++)
9997 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9998 
9999 	kvfree(dev->_rx);
10000 }
10001 
10002 static void netdev_init_one_queue(struct net_device *dev,
10003 				  struct netdev_queue *queue, void *_unused)
10004 {
10005 	/* Initialize queue lock */
10006 	spin_lock_init(&queue->_xmit_lock);
10007 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
10008 	queue->xmit_lock_owner = -1;
10009 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
10010 	queue->dev = dev;
10011 #ifdef CONFIG_BQL
10012 	dql_init(&queue->dql, HZ);
10013 #endif
10014 }
10015 
10016 static void netif_free_tx_queues(struct net_device *dev)
10017 {
10018 	kvfree(dev->_tx);
10019 }
10020 
10021 static int netif_alloc_netdev_queues(struct net_device *dev)
10022 {
10023 	unsigned int count = dev->num_tx_queues;
10024 	struct netdev_queue *tx;
10025 	size_t sz = count * sizeof(*tx);
10026 
10027 	if (count < 1 || count > 0xffff)
10028 		return -EINVAL;
10029 
10030 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10031 	if (!tx)
10032 		return -ENOMEM;
10033 
10034 	dev->_tx = tx;
10035 
10036 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
10037 	spin_lock_init(&dev->tx_global_lock);
10038 
10039 	return 0;
10040 }
10041 
10042 void netif_tx_stop_all_queues(struct net_device *dev)
10043 {
10044 	unsigned int i;
10045 
10046 	for (i = 0; i < dev->num_tx_queues; i++) {
10047 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
10048 
10049 		netif_tx_stop_queue(txq);
10050 	}
10051 }
10052 EXPORT_SYMBOL(netif_tx_stop_all_queues);
10053 
10054 /**
10055  * register_netdevice() - register a network device
10056  * @dev: device to register
10057  *
10058  * Take a prepared network device structure and make it externally accessible.
10059  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
10060  * Callers must hold the rtnl lock - you may want register_netdev()
10061  * instead of this.
10062  */
10063 int register_netdevice(struct net_device *dev)
10064 {
10065 	int ret;
10066 	struct net *net = dev_net(dev);
10067 
10068 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
10069 		     NETDEV_FEATURE_COUNT);
10070 	BUG_ON(dev_boot_phase);
10071 	ASSERT_RTNL();
10072 
10073 	might_sleep();
10074 
10075 	/* When net_device's are persistent, this will be fatal. */
10076 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
10077 	BUG_ON(!net);
10078 
10079 	ret = ethtool_check_ops(dev->ethtool_ops);
10080 	if (ret)
10081 		return ret;
10082 
10083 	spin_lock_init(&dev->addr_list_lock);
10084 	netdev_set_addr_lockdep_class(dev);
10085 
10086 	ret = dev_get_valid_name(net, dev, dev->name);
10087 	if (ret < 0)
10088 		goto out;
10089 
10090 	ret = -ENOMEM;
10091 	dev->name_node = netdev_name_node_head_alloc(dev);
10092 	if (!dev->name_node)
10093 		goto out;
10094 
10095 	/* Init, if this function is available */
10096 	if (dev->netdev_ops->ndo_init) {
10097 		ret = dev->netdev_ops->ndo_init(dev);
10098 		if (ret) {
10099 			if (ret > 0)
10100 				ret = -EIO;
10101 			goto err_free_name;
10102 		}
10103 	}
10104 
10105 	if (((dev->hw_features | dev->features) &
10106 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10107 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10108 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10109 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10110 		ret = -EINVAL;
10111 		goto err_uninit;
10112 	}
10113 
10114 	ret = dev_index_reserve(net, dev->ifindex);
10115 	if (ret < 0)
10116 		goto err_uninit;
10117 	dev->ifindex = ret;
10118 
10119 	/* Transfer changeable features to wanted_features and enable
10120 	 * software offloads (GSO and GRO).
10121 	 */
10122 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10123 	dev->features |= NETIF_F_SOFT_FEATURES;
10124 
10125 	if (dev->udp_tunnel_nic_info) {
10126 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10127 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10128 	}
10129 
10130 	dev->wanted_features = dev->features & dev->hw_features;
10131 
10132 	if (!(dev->flags & IFF_LOOPBACK))
10133 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10134 
10135 	/* If IPv4 TCP segmentation offload is supported we should also
10136 	 * allow the device to enable segmenting the frame with the option
10137 	 * of ignoring a static IP ID value.  This doesn't enable the
10138 	 * feature itself but allows the user to enable it later.
10139 	 */
10140 	if (dev->hw_features & NETIF_F_TSO)
10141 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10142 	if (dev->vlan_features & NETIF_F_TSO)
10143 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10144 	if (dev->mpls_features & NETIF_F_TSO)
10145 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10146 	if (dev->hw_enc_features & NETIF_F_TSO)
10147 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10148 
10149 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10150 	 */
10151 	dev->vlan_features |= NETIF_F_HIGHDMA;
10152 
10153 	/* Make NETIF_F_SG inheritable to tunnel devices.
10154 	 */
10155 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10156 
10157 	/* Make NETIF_F_SG inheritable to MPLS.
10158 	 */
10159 	dev->mpls_features |= NETIF_F_SG;
10160 
10161 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10162 	ret = notifier_to_errno(ret);
10163 	if (ret)
10164 		goto err_ifindex_release;
10165 
10166 	ret = netdev_register_kobject(dev);
10167 	write_lock(&dev_base_lock);
10168 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10169 	write_unlock(&dev_base_lock);
10170 	if (ret)
10171 		goto err_uninit_notify;
10172 
10173 	__netdev_update_features(dev);
10174 
10175 	/*
10176 	 *	Default initial state at registry is that the
10177 	 *	device is present.
10178 	 */
10179 
10180 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10181 
10182 	linkwatch_init_dev(dev);
10183 
10184 	dev_init_scheduler(dev);
10185 
10186 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10187 	list_netdevice(dev);
10188 
10189 	add_device_randomness(dev->dev_addr, dev->addr_len);
10190 
10191 	/* If the device has permanent device address, driver should
10192 	 * set dev_addr and also addr_assign_type should be set to
10193 	 * NET_ADDR_PERM (default value).
10194 	 */
10195 	if (dev->addr_assign_type == NET_ADDR_PERM)
10196 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10197 
10198 	/* Notify protocols, that a new device appeared. */
10199 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10200 	ret = notifier_to_errno(ret);
10201 	if (ret) {
10202 		/* Expect explicit free_netdev() on failure */
10203 		dev->needs_free_netdev = false;
10204 		unregister_netdevice_queue(dev, NULL);
10205 		goto out;
10206 	}
10207 	/*
10208 	 *	Prevent userspace races by waiting until the network
10209 	 *	device is fully setup before sending notifications.
10210 	 */
10211 	if (!dev->rtnl_link_ops ||
10212 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10213 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10214 
10215 out:
10216 	return ret;
10217 
10218 err_uninit_notify:
10219 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10220 err_ifindex_release:
10221 	dev_index_release(net, dev->ifindex);
10222 err_uninit:
10223 	if (dev->netdev_ops->ndo_uninit)
10224 		dev->netdev_ops->ndo_uninit(dev);
10225 	if (dev->priv_destructor)
10226 		dev->priv_destructor(dev);
10227 err_free_name:
10228 	netdev_name_node_free(dev->name_node);
10229 	goto out;
10230 }
10231 EXPORT_SYMBOL(register_netdevice);
10232 
10233 /**
10234  *	init_dummy_netdev	- init a dummy network device for NAPI
10235  *	@dev: device to init
10236  *
10237  *	This takes a network device structure and initialize the minimum
10238  *	amount of fields so it can be used to schedule NAPI polls without
10239  *	registering a full blown interface. This is to be used by drivers
10240  *	that need to tie several hardware interfaces to a single NAPI
10241  *	poll scheduler due to HW limitations.
10242  */
10243 int init_dummy_netdev(struct net_device *dev)
10244 {
10245 	/* Clear everything. Note we don't initialize spinlocks
10246 	 * are they aren't supposed to be taken by any of the
10247 	 * NAPI code and this dummy netdev is supposed to be
10248 	 * only ever used for NAPI polls
10249 	 */
10250 	memset(dev, 0, sizeof(struct net_device));
10251 
10252 	/* make sure we BUG if trying to hit standard
10253 	 * register/unregister code path
10254 	 */
10255 	dev->reg_state = NETREG_DUMMY;
10256 
10257 	/* NAPI wants this */
10258 	INIT_LIST_HEAD(&dev->napi_list);
10259 
10260 	/* a dummy interface is started by default */
10261 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10262 	set_bit(__LINK_STATE_START, &dev->state);
10263 
10264 	/* napi_busy_loop stats accounting wants this */
10265 	dev_net_set(dev, &init_net);
10266 
10267 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10268 	 * because users of this 'device' dont need to change
10269 	 * its refcount.
10270 	 */
10271 
10272 	return 0;
10273 }
10274 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10275 
10276 
10277 /**
10278  *	register_netdev	- register a network device
10279  *	@dev: device to register
10280  *
10281  *	Take a completed network device structure and add it to the kernel
10282  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10283  *	chain. 0 is returned on success. A negative errno code is returned
10284  *	on a failure to set up the device, or if the name is a duplicate.
10285  *
10286  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10287  *	and expands the device name if you passed a format string to
10288  *	alloc_netdev.
10289  */
10290 int register_netdev(struct net_device *dev)
10291 {
10292 	int err;
10293 
10294 	if (rtnl_lock_killable())
10295 		return -EINTR;
10296 	err = register_netdevice(dev);
10297 	rtnl_unlock();
10298 	return err;
10299 }
10300 EXPORT_SYMBOL(register_netdev);
10301 
10302 int netdev_refcnt_read(const struct net_device *dev)
10303 {
10304 #ifdef CONFIG_PCPU_DEV_REFCNT
10305 	int i, refcnt = 0;
10306 
10307 	for_each_possible_cpu(i)
10308 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10309 	return refcnt;
10310 #else
10311 	return refcount_read(&dev->dev_refcnt);
10312 #endif
10313 }
10314 EXPORT_SYMBOL(netdev_refcnt_read);
10315 
10316 int netdev_unregister_timeout_secs __read_mostly = 10;
10317 
10318 #define WAIT_REFS_MIN_MSECS 1
10319 #define WAIT_REFS_MAX_MSECS 250
10320 /**
10321  * netdev_wait_allrefs_any - wait until all references are gone.
10322  * @list: list of net_devices to wait on
10323  *
10324  * This is called when unregistering network devices.
10325  *
10326  * Any protocol or device that holds a reference should register
10327  * for netdevice notification, and cleanup and put back the
10328  * reference if they receive an UNREGISTER event.
10329  * We can get stuck here if buggy protocols don't correctly
10330  * call dev_put.
10331  */
10332 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10333 {
10334 	unsigned long rebroadcast_time, warning_time;
10335 	struct net_device *dev;
10336 	int wait = 0;
10337 
10338 	rebroadcast_time = warning_time = jiffies;
10339 
10340 	list_for_each_entry(dev, list, todo_list)
10341 		if (netdev_refcnt_read(dev) == 1)
10342 			return dev;
10343 
10344 	while (true) {
10345 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10346 			rtnl_lock();
10347 
10348 			/* Rebroadcast unregister notification */
10349 			list_for_each_entry(dev, list, todo_list)
10350 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10351 
10352 			__rtnl_unlock();
10353 			rcu_barrier();
10354 			rtnl_lock();
10355 
10356 			list_for_each_entry(dev, list, todo_list)
10357 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10358 					     &dev->state)) {
10359 					/* We must not have linkwatch events
10360 					 * pending on unregister. If this
10361 					 * happens, we simply run the queue
10362 					 * unscheduled, resulting in a noop
10363 					 * for this device.
10364 					 */
10365 					linkwatch_run_queue();
10366 					break;
10367 				}
10368 
10369 			__rtnl_unlock();
10370 
10371 			rebroadcast_time = jiffies;
10372 		}
10373 
10374 		if (!wait) {
10375 			rcu_barrier();
10376 			wait = WAIT_REFS_MIN_MSECS;
10377 		} else {
10378 			msleep(wait);
10379 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10380 		}
10381 
10382 		list_for_each_entry(dev, list, todo_list)
10383 			if (netdev_refcnt_read(dev) == 1)
10384 				return dev;
10385 
10386 		if (time_after(jiffies, warning_time +
10387 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10388 			list_for_each_entry(dev, list, todo_list) {
10389 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10390 					 dev->name, netdev_refcnt_read(dev));
10391 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10392 			}
10393 
10394 			warning_time = jiffies;
10395 		}
10396 	}
10397 }
10398 
10399 /* The sequence is:
10400  *
10401  *	rtnl_lock();
10402  *	...
10403  *	register_netdevice(x1);
10404  *	register_netdevice(x2);
10405  *	...
10406  *	unregister_netdevice(y1);
10407  *	unregister_netdevice(y2);
10408  *      ...
10409  *	rtnl_unlock();
10410  *	free_netdev(y1);
10411  *	free_netdev(y2);
10412  *
10413  * We are invoked by rtnl_unlock().
10414  * This allows us to deal with problems:
10415  * 1) We can delete sysfs objects which invoke hotplug
10416  *    without deadlocking with linkwatch via keventd.
10417  * 2) Since we run with the RTNL semaphore not held, we can sleep
10418  *    safely in order to wait for the netdev refcnt to drop to zero.
10419  *
10420  * We must not return until all unregister events added during
10421  * the interval the lock was held have been completed.
10422  */
10423 void netdev_run_todo(void)
10424 {
10425 	struct net_device *dev, *tmp;
10426 	struct list_head list;
10427 #ifdef CONFIG_LOCKDEP
10428 	struct list_head unlink_list;
10429 
10430 	list_replace_init(&net_unlink_list, &unlink_list);
10431 
10432 	while (!list_empty(&unlink_list)) {
10433 		struct net_device *dev = list_first_entry(&unlink_list,
10434 							  struct net_device,
10435 							  unlink_list);
10436 		list_del_init(&dev->unlink_list);
10437 		dev->nested_level = dev->lower_level - 1;
10438 	}
10439 #endif
10440 
10441 	/* Snapshot list, allow later requests */
10442 	list_replace_init(&net_todo_list, &list);
10443 
10444 	__rtnl_unlock();
10445 
10446 	/* Wait for rcu callbacks to finish before next phase */
10447 	if (!list_empty(&list))
10448 		rcu_barrier();
10449 
10450 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10451 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10452 			netdev_WARN(dev, "run_todo but not unregistering\n");
10453 			list_del(&dev->todo_list);
10454 			continue;
10455 		}
10456 
10457 		write_lock(&dev_base_lock);
10458 		dev->reg_state = NETREG_UNREGISTERED;
10459 		write_unlock(&dev_base_lock);
10460 		linkwatch_forget_dev(dev);
10461 	}
10462 
10463 	while (!list_empty(&list)) {
10464 		dev = netdev_wait_allrefs_any(&list);
10465 		list_del(&dev->todo_list);
10466 
10467 		/* paranoia */
10468 		BUG_ON(netdev_refcnt_read(dev) != 1);
10469 		BUG_ON(!list_empty(&dev->ptype_all));
10470 		BUG_ON(!list_empty(&dev->ptype_specific));
10471 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10472 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10473 
10474 		if (dev->priv_destructor)
10475 			dev->priv_destructor(dev);
10476 		if (dev->needs_free_netdev)
10477 			free_netdev(dev);
10478 
10479 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10480 			wake_up(&netdev_unregistering_wq);
10481 
10482 		/* Free network device */
10483 		kobject_put(&dev->dev.kobj);
10484 	}
10485 }
10486 
10487 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10488  * all the same fields in the same order as net_device_stats, with only
10489  * the type differing, but rtnl_link_stats64 may have additional fields
10490  * at the end for newer counters.
10491  */
10492 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10493 			     const struct net_device_stats *netdev_stats)
10494 {
10495 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10496 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10497 	u64 *dst = (u64 *)stats64;
10498 
10499 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10500 	for (i = 0; i < n; i++)
10501 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10502 	/* zero out counters that only exist in rtnl_link_stats64 */
10503 	memset((char *)stats64 + n * sizeof(u64), 0,
10504 	       sizeof(*stats64) - n * sizeof(u64));
10505 }
10506 EXPORT_SYMBOL(netdev_stats_to_stats64);
10507 
10508 static __cold struct net_device_core_stats __percpu *netdev_core_stats_alloc(
10509 		struct net_device *dev)
10510 {
10511 	struct net_device_core_stats __percpu *p;
10512 
10513 	p = alloc_percpu_gfp(struct net_device_core_stats,
10514 			     GFP_ATOMIC | __GFP_NOWARN);
10515 
10516 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10517 		free_percpu(p);
10518 
10519 	/* This READ_ONCE() pairs with the cmpxchg() above */
10520 	return READ_ONCE(dev->core_stats);
10521 }
10522 
10523 noinline void netdev_core_stats_inc(struct net_device *dev, u32 offset)
10524 {
10525 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10526 	struct net_device_core_stats __percpu *p = READ_ONCE(dev->core_stats);
10527 	unsigned long __percpu *field;
10528 
10529 	if (unlikely(!p)) {
10530 		p = netdev_core_stats_alloc(dev);
10531 		if (!p)
10532 			return;
10533 	}
10534 
10535 	field = (__force unsigned long __percpu *)((__force void *)p + offset);
10536 	this_cpu_inc(*field);
10537 }
10538 EXPORT_SYMBOL_GPL(netdev_core_stats_inc);
10539 
10540 /**
10541  *	dev_get_stats	- get network device statistics
10542  *	@dev: device to get statistics from
10543  *	@storage: place to store stats
10544  *
10545  *	Get network statistics from device. Return @storage.
10546  *	The device driver may provide its own method by setting
10547  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10548  *	otherwise the internal statistics structure is used.
10549  */
10550 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10551 					struct rtnl_link_stats64 *storage)
10552 {
10553 	const struct net_device_ops *ops = dev->netdev_ops;
10554 	const struct net_device_core_stats __percpu *p;
10555 
10556 	if (ops->ndo_get_stats64) {
10557 		memset(storage, 0, sizeof(*storage));
10558 		ops->ndo_get_stats64(dev, storage);
10559 	} else if (ops->ndo_get_stats) {
10560 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10561 	} else {
10562 		netdev_stats_to_stats64(storage, &dev->stats);
10563 	}
10564 
10565 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10566 	p = READ_ONCE(dev->core_stats);
10567 	if (p) {
10568 		const struct net_device_core_stats *core_stats;
10569 		int i;
10570 
10571 		for_each_possible_cpu(i) {
10572 			core_stats = per_cpu_ptr(p, i);
10573 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10574 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10575 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10576 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10577 		}
10578 	}
10579 	return storage;
10580 }
10581 EXPORT_SYMBOL(dev_get_stats);
10582 
10583 /**
10584  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10585  *	@s: place to store stats
10586  *	@netstats: per-cpu network stats to read from
10587  *
10588  *	Read per-cpu network statistics and populate the related fields in @s.
10589  */
10590 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10591 			   const struct pcpu_sw_netstats __percpu *netstats)
10592 {
10593 	int cpu;
10594 
10595 	for_each_possible_cpu(cpu) {
10596 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10597 		const struct pcpu_sw_netstats *stats;
10598 		unsigned int start;
10599 
10600 		stats = per_cpu_ptr(netstats, cpu);
10601 		do {
10602 			start = u64_stats_fetch_begin(&stats->syncp);
10603 			rx_packets = u64_stats_read(&stats->rx_packets);
10604 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10605 			tx_packets = u64_stats_read(&stats->tx_packets);
10606 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10607 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10608 
10609 		s->rx_packets += rx_packets;
10610 		s->rx_bytes   += rx_bytes;
10611 		s->tx_packets += tx_packets;
10612 		s->tx_bytes   += tx_bytes;
10613 	}
10614 }
10615 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10616 
10617 /**
10618  *	dev_get_tstats64 - ndo_get_stats64 implementation
10619  *	@dev: device to get statistics from
10620  *	@s: place to store stats
10621  *
10622  *	Populate @s from dev->stats and dev->tstats. Can be used as
10623  *	ndo_get_stats64() callback.
10624  */
10625 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10626 {
10627 	netdev_stats_to_stats64(s, &dev->stats);
10628 	dev_fetch_sw_netstats(s, dev->tstats);
10629 }
10630 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10631 
10632 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10633 {
10634 	struct netdev_queue *queue = dev_ingress_queue(dev);
10635 
10636 #ifdef CONFIG_NET_CLS_ACT
10637 	if (queue)
10638 		return queue;
10639 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10640 	if (!queue)
10641 		return NULL;
10642 	netdev_init_one_queue(dev, queue, NULL);
10643 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10644 	RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
10645 	rcu_assign_pointer(dev->ingress_queue, queue);
10646 #endif
10647 	return queue;
10648 }
10649 
10650 static const struct ethtool_ops default_ethtool_ops;
10651 
10652 void netdev_set_default_ethtool_ops(struct net_device *dev,
10653 				    const struct ethtool_ops *ops)
10654 {
10655 	if (dev->ethtool_ops == &default_ethtool_ops)
10656 		dev->ethtool_ops = ops;
10657 }
10658 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10659 
10660 /**
10661  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10662  * @dev: netdev to enable the IRQ coalescing on
10663  *
10664  * Sets a conservative default for SW IRQ coalescing. Users can use
10665  * sysfs attributes to override the default values.
10666  */
10667 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10668 {
10669 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10670 
10671 	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
10672 		dev->gro_flush_timeout = 20000;
10673 		dev->napi_defer_hard_irqs = 1;
10674 	}
10675 }
10676 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10677 
10678 void netdev_freemem(struct net_device *dev)
10679 {
10680 	char *addr = (char *)dev - dev->padded;
10681 
10682 	kvfree(addr);
10683 }
10684 
10685 /**
10686  * alloc_netdev_mqs - allocate network device
10687  * @sizeof_priv: size of private data to allocate space for
10688  * @name: device name format string
10689  * @name_assign_type: origin of device name
10690  * @setup: callback to initialize device
10691  * @txqs: the number of TX subqueues to allocate
10692  * @rxqs: the number of RX subqueues to allocate
10693  *
10694  * Allocates a struct net_device with private data area for driver use
10695  * and performs basic initialization.  Also allocates subqueue structs
10696  * for each queue on the device.
10697  */
10698 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10699 		unsigned char name_assign_type,
10700 		void (*setup)(struct net_device *),
10701 		unsigned int txqs, unsigned int rxqs)
10702 {
10703 	struct net_device *dev;
10704 	unsigned int alloc_size;
10705 	struct net_device *p;
10706 
10707 	BUG_ON(strlen(name) >= sizeof(dev->name));
10708 
10709 	if (txqs < 1) {
10710 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10711 		return NULL;
10712 	}
10713 
10714 	if (rxqs < 1) {
10715 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10716 		return NULL;
10717 	}
10718 
10719 	alloc_size = sizeof(struct net_device);
10720 	if (sizeof_priv) {
10721 		/* ensure 32-byte alignment of private area */
10722 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10723 		alloc_size += sizeof_priv;
10724 	}
10725 	/* ensure 32-byte alignment of whole construct */
10726 	alloc_size += NETDEV_ALIGN - 1;
10727 
10728 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10729 	if (!p)
10730 		return NULL;
10731 
10732 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10733 	dev->padded = (char *)dev - (char *)p;
10734 
10735 	ref_tracker_dir_init(&dev->refcnt_tracker, 128, name);
10736 #ifdef CONFIG_PCPU_DEV_REFCNT
10737 	dev->pcpu_refcnt = alloc_percpu(int);
10738 	if (!dev->pcpu_refcnt)
10739 		goto free_dev;
10740 	__dev_hold(dev);
10741 #else
10742 	refcount_set(&dev->dev_refcnt, 1);
10743 #endif
10744 
10745 	if (dev_addr_init(dev))
10746 		goto free_pcpu;
10747 
10748 	dev_mc_init(dev);
10749 	dev_uc_init(dev);
10750 
10751 	dev_net_set(dev, &init_net);
10752 
10753 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10754 	dev->xdp_zc_max_segs = 1;
10755 	dev->gso_max_segs = GSO_MAX_SEGS;
10756 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10757 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10758 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10759 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10760 	dev->tso_max_segs = TSO_MAX_SEGS;
10761 	dev->upper_level = 1;
10762 	dev->lower_level = 1;
10763 #ifdef CONFIG_LOCKDEP
10764 	dev->nested_level = 0;
10765 	INIT_LIST_HEAD(&dev->unlink_list);
10766 #endif
10767 
10768 	INIT_LIST_HEAD(&dev->napi_list);
10769 	INIT_LIST_HEAD(&dev->unreg_list);
10770 	INIT_LIST_HEAD(&dev->close_list);
10771 	INIT_LIST_HEAD(&dev->link_watch_list);
10772 	INIT_LIST_HEAD(&dev->adj_list.upper);
10773 	INIT_LIST_HEAD(&dev->adj_list.lower);
10774 	INIT_LIST_HEAD(&dev->ptype_all);
10775 	INIT_LIST_HEAD(&dev->ptype_specific);
10776 	INIT_LIST_HEAD(&dev->net_notifier_list);
10777 #ifdef CONFIG_NET_SCHED
10778 	hash_init(dev->qdisc_hash);
10779 #endif
10780 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10781 	setup(dev);
10782 
10783 	if (!dev->tx_queue_len) {
10784 		dev->priv_flags |= IFF_NO_QUEUE;
10785 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10786 	}
10787 
10788 	dev->num_tx_queues = txqs;
10789 	dev->real_num_tx_queues = txqs;
10790 	if (netif_alloc_netdev_queues(dev))
10791 		goto free_all;
10792 
10793 	dev->num_rx_queues = rxqs;
10794 	dev->real_num_rx_queues = rxqs;
10795 	if (netif_alloc_rx_queues(dev))
10796 		goto free_all;
10797 
10798 	strcpy(dev->name, name);
10799 	dev->name_assign_type = name_assign_type;
10800 	dev->group = INIT_NETDEV_GROUP;
10801 	if (!dev->ethtool_ops)
10802 		dev->ethtool_ops = &default_ethtool_ops;
10803 
10804 	nf_hook_netdev_init(dev);
10805 
10806 	return dev;
10807 
10808 free_all:
10809 	free_netdev(dev);
10810 	return NULL;
10811 
10812 free_pcpu:
10813 #ifdef CONFIG_PCPU_DEV_REFCNT
10814 	free_percpu(dev->pcpu_refcnt);
10815 free_dev:
10816 #endif
10817 	netdev_freemem(dev);
10818 	return NULL;
10819 }
10820 EXPORT_SYMBOL(alloc_netdev_mqs);
10821 
10822 /**
10823  * free_netdev - free network device
10824  * @dev: device
10825  *
10826  * This function does the last stage of destroying an allocated device
10827  * interface. The reference to the device object is released. If this
10828  * is the last reference then it will be freed.Must be called in process
10829  * context.
10830  */
10831 void free_netdev(struct net_device *dev)
10832 {
10833 	struct napi_struct *p, *n;
10834 
10835 	might_sleep();
10836 
10837 	/* When called immediately after register_netdevice() failed the unwind
10838 	 * handling may still be dismantling the device. Handle that case by
10839 	 * deferring the free.
10840 	 */
10841 	if (dev->reg_state == NETREG_UNREGISTERING) {
10842 		ASSERT_RTNL();
10843 		dev->needs_free_netdev = true;
10844 		return;
10845 	}
10846 
10847 	netif_free_tx_queues(dev);
10848 	netif_free_rx_queues(dev);
10849 
10850 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10851 
10852 	/* Flush device addresses */
10853 	dev_addr_flush(dev);
10854 
10855 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10856 		netif_napi_del(p);
10857 
10858 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10859 #ifdef CONFIG_PCPU_DEV_REFCNT
10860 	free_percpu(dev->pcpu_refcnt);
10861 	dev->pcpu_refcnt = NULL;
10862 #endif
10863 	free_percpu(dev->core_stats);
10864 	dev->core_stats = NULL;
10865 	free_percpu(dev->xdp_bulkq);
10866 	dev->xdp_bulkq = NULL;
10867 
10868 	/*  Compatibility with error handling in drivers */
10869 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10870 		netdev_freemem(dev);
10871 		return;
10872 	}
10873 
10874 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10875 	dev->reg_state = NETREG_RELEASED;
10876 
10877 	/* will free via device release */
10878 	put_device(&dev->dev);
10879 }
10880 EXPORT_SYMBOL(free_netdev);
10881 
10882 /**
10883  *	synchronize_net -  Synchronize with packet receive processing
10884  *
10885  *	Wait for packets currently being received to be done.
10886  *	Does not block later packets from starting.
10887  */
10888 void synchronize_net(void)
10889 {
10890 	might_sleep();
10891 	if (rtnl_is_locked())
10892 		synchronize_rcu_expedited();
10893 	else
10894 		synchronize_rcu();
10895 }
10896 EXPORT_SYMBOL(synchronize_net);
10897 
10898 /**
10899  *	unregister_netdevice_queue - remove device from the kernel
10900  *	@dev: device
10901  *	@head: list
10902  *
10903  *	This function shuts down a device interface and removes it
10904  *	from the kernel tables.
10905  *	If head not NULL, device is queued to be unregistered later.
10906  *
10907  *	Callers must hold the rtnl semaphore.  You may want
10908  *	unregister_netdev() instead of this.
10909  */
10910 
10911 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10912 {
10913 	ASSERT_RTNL();
10914 
10915 	if (head) {
10916 		list_move_tail(&dev->unreg_list, head);
10917 	} else {
10918 		LIST_HEAD(single);
10919 
10920 		list_add(&dev->unreg_list, &single);
10921 		unregister_netdevice_many(&single);
10922 	}
10923 }
10924 EXPORT_SYMBOL(unregister_netdevice_queue);
10925 
10926 void unregister_netdevice_many_notify(struct list_head *head,
10927 				      u32 portid, const struct nlmsghdr *nlh)
10928 {
10929 	struct net_device *dev, *tmp;
10930 	LIST_HEAD(close_head);
10931 
10932 	BUG_ON(dev_boot_phase);
10933 	ASSERT_RTNL();
10934 
10935 	if (list_empty(head))
10936 		return;
10937 
10938 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10939 		/* Some devices call without registering
10940 		 * for initialization unwind. Remove those
10941 		 * devices and proceed with the remaining.
10942 		 */
10943 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10944 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10945 				 dev->name, dev);
10946 
10947 			WARN_ON(1);
10948 			list_del(&dev->unreg_list);
10949 			continue;
10950 		}
10951 		dev->dismantle = true;
10952 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10953 	}
10954 
10955 	/* If device is running, close it first. */
10956 	list_for_each_entry(dev, head, unreg_list)
10957 		list_add_tail(&dev->close_list, &close_head);
10958 	dev_close_many(&close_head, true);
10959 
10960 	list_for_each_entry(dev, head, unreg_list) {
10961 		/* And unlink it from device chain. */
10962 		write_lock(&dev_base_lock);
10963 		unlist_netdevice(dev, false);
10964 		dev->reg_state = NETREG_UNREGISTERING;
10965 		write_unlock(&dev_base_lock);
10966 	}
10967 	flush_all_backlogs();
10968 
10969 	synchronize_net();
10970 
10971 	list_for_each_entry(dev, head, unreg_list) {
10972 		struct sk_buff *skb = NULL;
10973 
10974 		/* Shutdown queueing discipline. */
10975 		dev_shutdown(dev);
10976 		dev_tcx_uninstall(dev);
10977 		dev_xdp_uninstall(dev);
10978 		bpf_dev_bound_netdev_unregister(dev);
10979 
10980 		netdev_offload_xstats_disable_all(dev);
10981 
10982 		/* Notify protocols, that we are about to destroy
10983 		 * this device. They should clean all the things.
10984 		 */
10985 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10986 
10987 		if (!dev->rtnl_link_ops ||
10988 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10989 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10990 						     GFP_KERNEL, NULL, 0,
10991 						     portid, nlh);
10992 
10993 		/*
10994 		 *	Flush the unicast and multicast chains
10995 		 */
10996 		dev_uc_flush(dev);
10997 		dev_mc_flush(dev);
10998 
10999 		netdev_name_node_alt_flush(dev);
11000 		netdev_name_node_free(dev->name_node);
11001 
11002 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
11003 
11004 		if (dev->netdev_ops->ndo_uninit)
11005 			dev->netdev_ops->ndo_uninit(dev);
11006 
11007 		if (skb)
11008 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
11009 
11010 		/* Notifier chain MUST detach us all upper devices. */
11011 		WARN_ON(netdev_has_any_upper_dev(dev));
11012 		WARN_ON(netdev_has_any_lower_dev(dev));
11013 
11014 		/* Remove entries from kobject tree */
11015 		netdev_unregister_kobject(dev);
11016 #ifdef CONFIG_XPS
11017 		/* Remove XPS queueing entries */
11018 		netif_reset_xps_queues_gt(dev, 0);
11019 #endif
11020 	}
11021 
11022 	synchronize_net();
11023 
11024 	list_for_each_entry(dev, head, unreg_list) {
11025 		netdev_put(dev, &dev->dev_registered_tracker);
11026 		net_set_todo(dev);
11027 	}
11028 
11029 	list_del(head);
11030 }
11031 
11032 /**
11033  *	unregister_netdevice_many - unregister many devices
11034  *	@head: list of devices
11035  *
11036  *  Note: As most callers use a stack allocated list_head,
11037  *  we force a list_del() to make sure stack wont be corrupted later.
11038  */
11039 void unregister_netdevice_many(struct list_head *head)
11040 {
11041 	unregister_netdevice_many_notify(head, 0, NULL);
11042 }
11043 EXPORT_SYMBOL(unregister_netdevice_many);
11044 
11045 /**
11046  *	unregister_netdev - remove device from the kernel
11047  *	@dev: device
11048  *
11049  *	This function shuts down a device interface and removes it
11050  *	from the kernel tables.
11051  *
11052  *	This is just a wrapper for unregister_netdevice that takes
11053  *	the rtnl semaphore.  In general you want to use this and not
11054  *	unregister_netdevice.
11055  */
11056 void unregister_netdev(struct net_device *dev)
11057 {
11058 	rtnl_lock();
11059 	unregister_netdevice(dev);
11060 	rtnl_unlock();
11061 }
11062 EXPORT_SYMBOL(unregister_netdev);
11063 
11064 /**
11065  *	__dev_change_net_namespace - move device to different nethost namespace
11066  *	@dev: device
11067  *	@net: network namespace
11068  *	@pat: If not NULL name pattern to try if the current device name
11069  *	      is already taken in the destination network namespace.
11070  *	@new_ifindex: If not zero, specifies device index in the target
11071  *	              namespace.
11072  *
11073  *	This function shuts down a device interface and moves it
11074  *	to a new network namespace. On success 0 is returned, on
11075  *	a failure a netagive errno code is returned.
11076  *
11077  *	Callers must hold the rtnl semaphore.
11078  */
11079 
11080 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
11081 			       const char *pat, int new_ifindex)
11082 {
11083 	struct netdev_name_node *name_node;
11084 	struct net *net_old = dev_net(dev);
11085 	char new_name[IFNAMSIZ] = {};
11086 	int err, new_nsid;
11087 
11088 	ASSERT_RTNL();
11089 
11090 	/* Don't allow namespace local devices to be moved. */
11091 	err = -EINVAL;
11092 	if (dev->features & NETIF_F_NETNS_LOCAL)
11093 		goto out;
11094 
11095 	/* Ensure the device has been registrered */
11096 	if (dev->reg_state != NETREG_REGISTERED)
11097 		goto out;
11098 
11099 	/* Get out if there is nothing todo */
11100 	err = 0;
11101 	if (net_eq(net_old, net))
11102 		goto out;
11103 
11104 	/* Pick the destination device name, and ensure
11105 	 * we can use it in the destination network namespace.
11106 	 */
11107 	err = -EEXIST;
11108 	if (netdev_name_in_use(net, dev->name)) {
11109 		/* We get here if we can't use the current device name */
11110 		if (!pat)
11111 			goto out;
11112 		err = dev_prep_valid_name(net, dev, pat, new_name, EEXIST);
11113 		if (err < 0)
11114 			goto out;
11115 	}
11116 	/* Check that none of the altnames conflicts. */
11117 	err = -EEXIST;
11118 	netdev_for_each_altname(dev, name_node)
11119 		if (netdev_name_in_use(net, name_node->name))
11120 			goto out;
11121 
11122 	/* Check that new_ifindex isn't used yet. */
11123 	if (new_ifindex) {
11124 		err = dev_index_reserve(net, new_ifindex);
11125 		if (err < 0)
11126 			goto out;
11127 	} else {
11128 		/* If there is an ifindex conflict assign a new one */
11129 		err = dev_index_reserve(net, dev->ifindex);
11130 		if (err == -EBUSY)
11131 			err = dev_index_reserve(net, 0);
11132 		if (err < 0)
11133 			goto out;
11134 		new_ifindex = err;
11135 	}
11136 
11137 	/*
11138 	 * And now a mini version of register_netdevice unregister_netdevice.
11139 	 */
11140 
11141 	/* If device is running close it first. */
11142 	dev_close(dev);
11143 
11144 	/* And unlink it from device chain */
11145 	unlist_netdevice(dev, true);
11146 
11147 	synchronize_net();
11148 
11149 	/* Shutdown queueing discipline. */
11150 	dev_shutdown(dev);
11151 
11152 	/* Notify protocols, that we are about to destroy
11153 	 * this device. They should clean all the things.
11154 	 *
11155 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11156 	 * This is wanted because this way 8021q and macvlan know
11157 	 * the device is just moving and can keep their slaves up.
11158 	 */
11159 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11160 	rcu_barrier();
11161 
11162 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11163 
11164 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11165 			    new_ifindex);
11166 
11167 	/*
11168 	 *	Flush the unicast and multicast chains
11169 	 */
11170 	dev_uc_flush(dev);
11171 	dev_mc_flush(dev);
11172 
11173 	/* Send a netdev-removed uevent to the old namespace */
11174 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11175 	netdev_adjacent_del_links(dev);
11176 
11177 	/* Move per-net netdevice notifiers that are following the netdevice */
11178 	move_netdevice_notifiers_dev_net(dev, net);
11179 
11180 	/* Actually switch the network namespace */
11181 	dev_net_set(dev, net);
11182 	dev->ifindex = new_ifindex;
11183 
11184 	/* Send a netdev-add uevent to the new namespace */
11185 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11186 	netdev_adjacent_add_links(dev);
11187 
11188 	if (new_name[0]) /* Rename the netdev to prepared name */
11189 		strscpy(dev->name, new_name, IFNAMSIZ);
11190 
11191 	/* Fixup kobjects */
11192 	err = device_rename(&dev->dev, dev->name);
11193 	WARN_ON(err);
11194 
11195 	/* Adapt owner in case owning user namespace of target network
11196 	 * namespace is different from the original one.
11197 	 */
11198 	err = netdev_change_owner(dev, net_old, net);
11199 	WARN_ON(err);
11200 
11201 	/* Add the device back in the hashes */
11202 	list_netdevice(dev);
11203 
11204 	/* Notify protocols, that a new device appeared. */
11205 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11206 
11207 	/*
11208 	 *	Prevent userspace races by waiting until the network
11209 	 *	device is fully setup before sending notifications.
11210 	 */
11211 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11212 
11213 	synchronize_net();
11214 	err = 0;
11215 out:
11216 	return err;
11217 }
11218 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11219 
11220 static int dev_cpu_dead(unsigned int oldcpu)
11221 {
11222 	struct sk_buff **list_skb;
11223 	struct sk_buff *skb;
11224 	unsigned int cpu;
11225 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11226 
11227 	local_irq_disable();
11228 	cpu = smp_processor_id();
11229 	sd = &per_cpu(softnet_data, cpu);
11230 	oldsd = &per_cpu(softnet_data, oldcpu);
11231 
11232 	/* Find end of our completion_queue. */
11233 	list_skb = &sd->completion_queue;
11234 	while (*list_skb)
11235 		list_skb = &(*list_skb)->next;
11236 	/* Append completion queue from offline CPU. */
11237 	*list_skb = oldsd->completion_queue;
11238 	oldsd->completion_queue = NULL;
11239 
11240 	/* Append output queue from offline CPU. */
11241 	if (oldsd->output_queue) {
11242 		*sd->output_queue_tailp = oldsd->output_queue;
11243 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11244 		oldsd->output_queue = NULL;
11245 		oldsd->output_queue_tailp = &oldsd->output_queue;
11246 	}
11247 	/* Append NAPI poll list from offline CPU, with one exception :
11248 	 * process_backlog() must be called by cpu owning percpu backlog.
11249 	 * We properly handle process_queue & input_pkt_queue later.
11250 	 */
11251 	while (!list_empty(&oldsd->poll_list)) {
11252 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11253 							    struct napi_struct,
11254 							    poll_list);
11255 
11256 		list_del_init(&napi->poll_list);
11257 		if (napi->poll == process_backlog)
11258 			napi->state = 0;
11259 		else
11260 			____napi_schedule(sd, napi);
11261 	}
11262 
11263 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11264 	local_irq_enable();
11265 
11266 #ifdef CONFIG_RPS
11267 	remsd = oldsd->rps_ipi_list;
11268 	oldsd->rps_ipi_list = NULL;
11269 #endif
11270 	/* send out pending IPI's on offline CPU */
11271 	net_rps_send_ipi(remsd);
11272 
11273 	/* Process offline CPU's input_pkt_queue */
11274 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11275 		netif_rx(skb);
11276 		input_queue_head_incr(oldsd);
11277 	}
11278 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11279 		netif_rx(skb);
11280 		input_queue_head_incr(oldsd);
11281 	}
11282 
11283 	return 0;
11284 }
11285 
11286 /**
11287  *	netdev_increment_features - increment feature set by one
11288  *	@all: current feature set
11289  *	@one: new feature set
11290  *	@mask: mask feature set
11291  *
11292  *	Computes a new feature set after adding a device with feature set
11293  *	@one to the master device with current feature set @all.  Will not
11294  *	enable anything that is off in @mask. Returns the new feature set.
11295  */
11296 netdev_features_t netdev_increment_features(netdev_features_t all,
11297 	netdev_features_t one, netdev_features_t mask)
11298 {
11299 	if (mask & NETIF_F_HW_CSUM)
11300 		mask |= NETIF_F_CSUM_MASK;
11301 	mask |= NETIF_F_VLAN_CHALLENGED;
11302 
11303 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11304 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11305 
11306 	/* If one device supports hw checksumming, set for all. */
11307 	if (all & NETIF_F_HW_CSUM)
11308 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11309 
11310 	return all;
11311 }
11312 EXPORT_SYMBOL(netdev_increment_features);
11313 
11314 static struct hlist_head * __net_init netdev_create_hash(void)
11315 {
11316 	int i;
11317 	struct hlist_head *hash;
11318 
11319 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11320 	if (hash != NULL)
11321 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11322 			INIT_HLIST_HEAD(&hash[i]);
11323 
11324 	return hash;
11325 }
11326 
11327 /* Initialize per network namespace state */
11328 static int __net_init netdev_init(struct net *net)
11329 {
11330 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11331 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11332 
11333 	INIT_LIST_HEAD(&net->dev_base_head);
11334 
11335 	net->dev_name_head = netdev_create_hash();
11336 	if (net->dev_name_head == NULL)
11337 		goto err_name;
11338 
11339 	net->dev_index_head = netdev_create_hash();
11340 	if (net->dev_index_head == NULL)
11341 		goto err_idx;
11342 
11343 	xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1);
11344 
11345 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11346 
11347 	return 0;
11348 
11349 err_idx:
11350 	kfree(net->dev_name_head);
11351 err_name:
11352 	return -ENOMEM;
11353 }
11354 
11355 /**
11356  *	netdev_drivername - network driver for the device
11357  *	@dev: network device
11358  *
11359  *	Determine network driver for device.
11360  */
11361 const char *netdev_drivername(const struct net_device *dev)
11362 {
11363 	const struct device_driver *driver;
11364 	const struct device *parent;
11365 	const char *empty = "";
11366 
11367 	parent = dev->dev.parent;
11368 	if (!parent)
11369 		return empty;
11370 
11371 	driver = parent->driver;
11372 	if (driver && driver->name)
11373 		return driver->name;
11374 	return empty;
11375 }
11376 
11377 static void __netdev_printk(const char *level, const struct net_device *dev,
11378 			    struct va_format *vaf)
11379 {
11380 	if (dev && dev->dev.parent) {
11381 		dev_printk_emit(level[1] - '0',
11382 				dev->dev.parent,
11383 				"%s %s %s%s: %pV",
11384 				dev_driver_string(dev->dev.parent),
11385 				dev_name(dev->dev.parent),
11386 				netdev_name(dev), netdev_reg_state(dev),
11387 				vaf);
11388 	} else if (dev) {
11389 		printk("%s%s%s: %pV",
11390 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11391 	} else {
11392 		printk("%s(NULL net_device): %pV", level, vaf);
11393 	}
11394 }
11395 
11396 void netdev_printk(const char *level, const struct net_device *dev,
11397 		   const char *format, ...)
11398 {
11399 	struct va_format vaf;
11400 	va_list args;
11401 
11402 	va_start(args, format);
11403 
11404 	vaf.fmt = format;
11405 	vaf.va = &args;
11406 
11407 	__netdev_printk(level, dev, &vaf);
11408 
11409 	va_end(args);
11410 }
11411 EXPORT_SYMBOL(netdev_printk);
11412 
11413 #define define_netdev_printk_level(func, level)			\
11414 void func(const struct net_device *dev, const char *fmt, ...)	\
11415 {								\
11416 	struct va_format vaf;					\
11417 	va_list args;						\
11418 								\
11419 	va_start(args, fmt);					\
11420 								\
11421 	vaf.fmt = fmt;						\
11422 	vaf.va = &args;						\
11423 								\
11424 	__netdev_printk(level, dev, &vaf);			\
11425 								\
11426 	va_end(args);						\
11427 }								\
11428 EXPORT_SYMBOL(func);
11429 
11430 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11431 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11432 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11433 define_netdev_printk_level(netdev_err, KERN_ERR);
11434 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11435 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11436 define_netdev_printk_level(netdev_info, KERN_INFO);
11437 
11438 static void __net_exit netdev_exit(struct net *net)
11439 {
11440 	kfree(net->dev_name_head);
11441 	kfree(net->dev_index_head);
11442 	xa_destroy(&net->dev_by_index);
11443 	if (net != &init_net)
11444 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11445 }
11446 
11447 static struct pernet_operations __net_initdata netdev_net_ops = {
11448 	.init = netdev_init,
11449 	.exit = netdev_exit,
11450 };
11451 
11452 static void __net_exit default_device_exit_net(struct net *net)
11453 {
11454 	struct net_device *dev, *aux;
11455 	/*
11456 	 * Push all migratable network devices back to the
11457 	 * initial network namespace
11458 	 */
11459 	ASSERT_RTNL();
11460 	for_each_netdev_safe(net, dev, aux) {
11461 		int err;
11462 		char fb_name[IFNAMSIZ];
11463 
11464 		/* Ignore unmoveable devices (i.e. loopback) */
11465 		if (dev->features & NETIF_F_NETNS_LOCAL)
11466 			continue;
11467 
11468 		/* Leave virtual devices for the generic cleanup */
11469 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11470 			continue;
11471 
11472 		/* Push remaining network devices to init_net */
11473 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11474 		if (netdev_name_in_use(&init_net, fb_name))
11475 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11476 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11477 		if (err) {
11478 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11479 				 __func__, dev->name, err);
11480 			BUG();
11481 		}
11482 	}
11483 }
11484 
11485 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11486 {
11487 	/* At exit all network devices most be removed from a network
11488 	 * namespace.  Do this in the reverse order of registration.
11489 	 * Do this across as many network namespaces as possible to
11490 	 * improve batching efficiency.
11491 	 */
11492 	struct net_device *dev;
11493 	struct net *net;
11494 	LIST_HEAD(dev_kill_list);
11495 
11496 	rtnl_lock();
11497 	list_for_each_entry(net, net_list, exit_list) {
11498 		default_device_exit_net(net);
11499 		cond_resched();
11500 	}
11501 
11502 	list_for_each_entry(net, net_list, exit_list) {
11503 		for_each_netdev_reverse(net, dev) {
11504 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11505 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11506 			else
11507 				unregister_netdevice_queue(dev, &dev_kill_list);
11508 		}
11509 	}
11510 	unregister_netdevice_many(&dev_kill_list);
11511 	rtnl_unlock();
11512 }
11513 
11514 static struct pernet_operations __net_initdata default_device_ops = {
11515 	.exit_batch = default_device_exit_batch,
11516 };
11517 
11518 /*
11519  *	Initialize the DEV module. At boot time this walks the device list and
11520  *	unhooks any devices that fail to initialise (normally hardware not
11521  *	present) and leaves us with a valid list of present and active devices.
11522  *
11523  */
11524 
11525 /*
11526  *       This is called single threaded during boot, so no need
11527  *       to take the rtnl semaphore.
11528  */
11529 static int __init net_dev_init(void)
11530 {
11531 	int i, rc = -ENOMEM;
11532 
11533 	BUG_ON(!dev_boot_phase);
11534 
11535 	if (dev_proc_init())
11536 		goto out;
11537 
11538 	if (netdev_kobject_init())
11539 		goto out;
11540 
11541 	INIT_LIST_HEAD(&ptype_all);
11542 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11543 		INIT_LIST_HEAD(&ptype_base[i]);
11544 
11545 	if (register_pernet_subsys(&netdev_net_ops))
11546 		goto out;
11547 
11548 	/*
11549 	 *	Initialise the packet receive queues.
11550 	 */
11551 
11552 	for_each_possible_cpu(i) {
11553 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11554 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11555 
11556 		INIT_WORK(flush, flush_backlog);
11557 
11558 		skb_queue_head_init(&sd->input_pkt_queue);
11559 		skb_queue_head_init(&sd->process_queue);
11560 #ifdef CONFIG_XFRM_OFFLOAD
11561 		skb_queue_head_init(&sd->xfrm_backlog);
11562 #endif
11563 		INIT_LIST_HEAD(&sd->poll_list);
11564 		sd->output_queue_tailp = &sd->output_queue;
11565 #ifdef CONFIG_RPS
11566 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11567 		sd->cpu = i;
11568 #endif
11569 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11570 		spin_lock_init(&sd->defer_lock);
11571 
11572 		init_gro_hash(&sd->backlog);
11573 		sd->backlog.poll = process_backlog;
11574 		sd->backlog.weight = weight_p;
11575 	}
11576 
11577 	dev_boot_phase = 0;
11578 
11579 	/* The loopback device is special if any other network devices
11580 	 * is present in a network namespace the loopback device must
11581 	 * be present. Since we now dynamically allocate and free the
11582 	 * loopback device ensure this invariant is maintained by
11583 	 * keeping the loopback device as the first device on the
11584 	 * list of network devices.  Ensuring the loopback devices
11585 	 * is the first device that appears and the last network device
11586 	 * that disappears.
11587 	 */
11588 	if (register_pernet_device(&loopback_net_ops))
11589 		goto out;
11590 
11591 	if (register_pernet_device(&default_device_ops))
11592 		goto out;
11593 
11594 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11595 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11596 
11597 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11598 				       NULL, dev_cpu_dead);
11599 	WARN_ON(rc < 0);
11600 	rc = 0;
11601 out:
11602 	return rc;
11603 }
11604 
11605 subsys_initcall(net_dev_init);
11606