xref: /linux/net/core/dev.c (revision fbf46565c67c626849c7ce2a326972d3008d2a91)
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/bitops.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 <linux/highmem.h>
111 #include <linux/init.h>
112 #include <linux/module.h>
113 #include <linux/netpoll.h>
114 #include <linux/rcupdate.h>
115 #include <linux/delay.h>
116 #include <net/iw_handler.h>
117 #include <asm/current.h>
118 #include <linux/audit.h>
119 #include <linux/dmaengine.h>
120 #include <linux/err.h>
121 #include <linux/ctype.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_vlan.h>
124 #include <linux/ip.h>
125 #include <net/ip.h>
126 #include <net/mpls.h>
127 #include <linux/ipv6.h>
128 #include <linux/in.h>
129 #include <linux/jhash.h>
130 #include <linux/random.h>
131 #include <trace/events/napi.h>
132 #include <trace/events/net.h>
133 #include <trace/events/skb.h>
134 #include <trace/events/qdisc.h>
135 #include <linux/inetdevice.h>
136 #include <linux/cpu_rmap.h>
137 #include <linux/static_key.h>
138 #include <linux/hashtable.h>
139 #include <linux/vmalloc.h>
140 #include <linux/if_macvlan.h>
141 #include <linux/errqueue.h>
142 #include <linux/hrtimer.h>
143 #include <linux/netfilter_netdev.h>
144 #include <linux/crash_dump.h>
145 #include <linux/sctp.h>
146 #include <net/udp_tunnel.h>
147 #include <linux/net_namespace.h>
148 #include <linux/indirect_call_wrapper.h>
149 #include <net/devlink.h>
150 #include <linux/pm_runtime.h>
151 #include <linux/prandom.h>
152 #include <linux/once_lite.h>
153 
154 #include "dev.h"
155 #include "net-sysfs.h"
156 
157 
158 static DEFINE_SPINLOCK(ptype_lock);
159 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
160 struct list_head ptype_all __read_mostly;	/* Taps */
161 
162 static int netif_rx_internal(struct sk_buff *skb);
163 static int call_netdevice_notifiers_info(unsigned long val,
164 					 struct netdev_notifier_info *info);
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 	netdev_name_node_del(name_node);
349 	kfree(name_node->name);
350 	netdev_name_node_free(name_node);
351 }
352 
353 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
354 {
355 	struct netdev_name_node *name_node;
356 	struct net *net = dev_net(dev);
357 
358 	name_node = netdev_name_node_lookup(net, name);
359 	if (!name_node)
360 		return -ENOENT;
361 	/* lookup might have found our primary name or a name belonging
362 	 * to another device.
363 	 */
364 	if (name_node == dev->name_node || name_node->dev != dev)
365 		return -EINVAL;
366 
367 	__netdev_name_node_alt_destroy(name_node);
368 
369 	return 0;
370 }
371 
372 static void netdev_name_node_alt_flush(struct net_device *dev)
373 {
374 	struct netdev_name_node *name_node, *tmp;
375 
376 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
377 		__netdev_name_node_alt_destroy(name_node);
378 }
379 
380 /* Device list insertion */
381 static void list_netdevice(struct net_device *dev)
382 {
383 	struct net *net = dev_net(dev);
384 
385 	ASSERT_RTNL();
386 
387 	write_lock(&dev_base_lock);
388 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
389 	netdev_name_node_add(net, dev->name_node);
390 	hlist_add_head_rcu(&dev->index_hlist,
391 			   dev_index_hash(net, dev->ifindex));
392 	write_unlock(&dev_base_lock);
393 
394 	dev_base_seq_inc(net);
395 }
396 
397 /* Device list removal
398  * caller must respect a RCU grace period before freeing/reusing dev
399  */
400 static void unlist_netdevice(struct net_device *dev, bool lock)
401 {
402 	ASSERT_RTNL();
403 
404 	/* Unlink dev from the device chain */
405 	if (lock)
406 		write_lock(&dev_base_lock);
407 	list_del_rcu(&dev->dev_list);
408 	netdev_name_node_del(dev->name_node);
409 	hlist_del_rcu(&dev->index_hlist);
410 	if (lock)
411 		write_unlock(&dev_base_lock);
412 
413 	dev_base_seq_inc(dev_net(dev));
414 }
415 
416 /*
417  *	Our notifier list
418  */
419 
420 static RAW_NOTIFIER_HEAD(netdev_chain);
421 
422 /*
423  *	Device drivers call our routines to queue packets here. We empty the
424  *	queue in the local softnet handler.
425  */
426 
427 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
428 EXPORT_PER_CPU_SYMBOL(softnet_data);
429 
430 #ifdef CONFIG_LOCKDEP
431 /*
432  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
433  * according to dev->type
434  */
435 static const unsigned short netdev_lock_type[] = {
436 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
437 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
438 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
439 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
440 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
441 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
442 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
443 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
444 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
445 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
446 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
447 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
448 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
449 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
450 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
451 
452 static const char *const netdev_lock_name[] = {
453 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
454 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
455 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
456 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
457 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
458 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
459 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
460 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
461 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
462 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
463 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
464 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
465 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
466 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
467 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
468 
469 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
470 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
471 
472 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
473 {
474 	int i;
475 
476 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
477 		if (netdev_lock_type[i] == dev_type)
478 			return i;
479 	/* the last key is used by default */
480 	return ARRAY_SIZE(netdev_lock_type) - 1;
481 }
482 
483 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
484 						 unsigned short dev_type)
485 {
486 	int i;
487 
488 	i = netdev_lock_pos(dev_type);
489 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
490 				   netdev_lock_name[i]);
491 }
492 
493 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
494 {
495 	int i;
496 
497 	i = netdev_lock_pos(dev->type);
498 	lockdep_set_class_and_name(&dev->addr_list_lock,
499 				   &netdev_addr_lock_key[i],
500 				   netdev_lock_name[i]);
501 }
502 #else
503 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
504 						 unsigned short dev_type)
505 {
506 }
507 
508 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
509 {
510 }
511 #endif
512 
513 /*******************************************************************************
514  *
515  *		Protocol management and registration routines
516  *
517  *******************************************************************************/
518 
519 
520 /*
521  *	Add a protocol ID to the list. Now that the input handler is
522  *	smarter we can dispense with all the messy stuff that used to be
523  *	here.
524  *
525  *	BEWARE!!! Protocol handlers, mangling input packets,
526  *	MUST BE last in hash buckets and checking protocol handlers
527  *	MUST start from promiscuous ptype_all chain in net_bh.
528  *	It is true now, do not change it.
529  *	Explanation follows: if protocol handler, mangling packet, will
530  *	be the first on list, it is not able to sense, that packet
531  *	is cloned and should be copied-on-write, so that it will
532  *	change it and subsequent readers will get broken packet.
533  *							--ANK (980803)
534  */
535 
536 static inline struct list_head *ptype_head(const struct packet_type *pt)
537 {
538 	if (pt->type == htons(ETH_P_ALL))
539 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
540 	else
541 		return pt->dev ? &pt->dev->ptype_specific :
542 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
543 }
544 
545 /**
546  *	dev_add_pack - add packet handler
547  *	@pt: packet type declaration
548  *
549  *	Add a protocol handler to the networking stack. The passed &packet_type
550  *	is linked into kernel lists and may not be freed until it has been
551  *	removed from the kernel lists.
552  *
553  *	This call does not sleep therefore it can not
554  *	guarantee all CPU's that are in middle of receiving packets
555  *	will see the new packet type (until the next received packet).
556  */
557 
558 void dev_add_pack(struct packet_type *pt)
559 {
560 	struct list_head *head = ptype_head(pt);
561 
562 	spin_lock(&ptype_lock);
563 	list_add_rcu(&pt->list, head);
564 	spin_unlock(&ptype_lock);
565 }
566 EXPORT_SYMBOL(dev_add_pack);
567 
568 /**
569  *	__dev_remove_pack	 - remove packet handler
570  *	@pt: packet type declaration
571  *
572  *	Remove a protocol handler that was previously added to the kernel
573  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
574  *	from the kernel lists and can be freed or reused once this function
575  *	returns.
576  *
577  *      The packet type might still be in use by receivers
578  *	and must not be freed until after all the CPU's have gone
579  *	through a quiescent state.
580  */
581 void __dev_remove_pack(struct packet_type *pt)
582 {
583 	struct list_head *head = ptype_head(pt);
584 	struct packet_type *pt1;
585 
586 	spin_lock(&ptype_lock);
587 
588 	list_for_each_entry(pt1, head, list) {
589 		if (pt == pt1) {
590 			list_del_rcu(&pt->list);
591 			goto out;
592 		}
593 	}
594 
595 	pr_warn("dev_remove_pack: %p not found\n", pt);
596 out:
597 	spin_unlock(&ptype_lock);
598 }
599 EXPORT_SYMBOL(__dev_remove_pack);
600 
601 /**
602  *	dev_remove_pack	 - remove packet handler
603  *	@pt: packet type declaration
604  *
605  *	Remove a protocol handler that was previously added to the kernel
606  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
607  *	from the kernel lists and can be freed or reused once this function
608  *	returns.
609  *
610  *	This call sleeps to guarantee that no CPU is looking at the packet
611  *	type after return.
612  */
613 void dev_remove_pack(struct packet_type *pt)
614 {
615 	__dev_remove_pack(pt);
616 
617 	synchronize_net();
618 }
619 EXPORT_SYMBOL(dev_remove_pack);
620 
621 
622 /*******************************************************************************
623  *
624  *			    Device Interface Subroutines
625  *
626  *******************************************************************************/
627 
628 /**
629  *	dev_get_iflink	- get 'iflink' value of a interface
630  *	@dev: targeted interface
631  *
632  *	Indicates the ifindex the interface is linked to.
633  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
634  */
635 
636 int dev_get_iflink(const struct net_device *dev)
637 {
638 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
639 		return dev->netdev_ops->ndo_get_iflink(dev);
640 
641 	return dev->ifindex;
642 }
643 EXPORT_SYMBOL(dev_get_iflink);
644 
645 /**
646  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
647  *	@dev: targeted interface
648  *	@skb: The packet.
649  *
650  *	For better visibility of tunnel traffic OVS needs to retrieve
651  *	egress tunnel information for a packet. Following API allows
652  *	user to get this info.
653  */
654 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
655 {
656 	struct ip_tunnel_info *info;
657 
658 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
659 		return -EINVAL;
660 
661 	info = skb_tunnel_info_unclone(skb);
662 	if (!info)
663 		return -ENOMEM;
664 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
665 		return -EINVAL;
666 
667 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
668 }
669 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
670 
671 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
672 {
673 	int k = stack->num_paths++;
674 
675 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
676 		return NULL;
677 
678 	return &stack->path[k];
679 }
680 
681 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
682 			  struct net_device_path_stack *stack)
683 {
684 	const struct net_device *last_dev;
685 	struct net_device_path_ctx ctx = {
686 		.dev	= dev,
687 	};
688 	struct net_device_path *path;
689 	int ret = 0;
690 
691 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
692 	stack->num_paths = 0;
693 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
694 		last_dev = ctx.dev;
695 		path = dev_fwd_path(stack);
696 		if (!path)
697 			return -1;
698 
699 		memset(path, 0, sizeof(struct net_device_path));
700 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
701 		if (ret < 0)
702 			return -1;
703 
704 		if (WARN_ON_ONCE(last_dev == ctx.dev))
705 			return -1;
706 	}
707 
708 	if (!ctx.dev)
709 		return ret;
710 
711 	path = dev_fwd_path(stack);
712 	if (!path)
713 		return -1;
714 	path->type = DEV_PATH_ETHERNET;
715 	path->dev = ctx.dev;
716 
717 	return ret;
718 }
719 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
720 
721 /**
722  *	__dev_get_by_name	- find a device by its name
723  *	@net: the applicable net namespace
724  *	@name: name to find
725  *
726  *	Find an interface by name. Must be called under RTNL semaphore
727  *	or @dev_base_lock. If the name is found a pointer to the device
728  *	is returned. If the name is not found then %NULL is returned. The
729  *	reference counters are not incremented so the caller must be
730  *	careful with locks.
731  */
732 
733 struct net_device *__dev_get_by_name(struct net *net, const char *name)
734 {
735 	struct netdev_name_node *node_name;
736 
737 	node_name = netdev_name_node_lookup(net, name);
738 	return node_name ? node_name->dev : NULL;
739 }
740 EXPORT_SYMBOL(__dev_get_by_name);
741 
742 /**
743  * dev_get_by_name_rcu	- find a device by its name
744  * @net: the applicable net namespace
745  * @name: name to find
746  *
747  * Find an interface by name.
748  * If the name is found a pointer to the device is returned.
749  * If the name is not found then %NULL is returned.
750  * The reference counters are not incremented so the caller must be
751  * careful with locks. The caller must hold RCU lock.
752  */
753 
754 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
755 {
756 	struct netdev_name_node *node_name;
757 
758 	node_name = netdev_name_node_lookup_rcu(net, name);
759 	return node_name ? node_name->dev : NULL;
760 }
761 EXPORT_SYMBOL(dev_get_by_name_rcu);
762 
763 /**
764  *	dev_get_by_name		- find a device by its name
765  *	@net: the applicable net namespace
766  *	@name: name to find
767  *
768  *	Find an interface by name. This can be called from any
769  *	context and does its own locking. The returned handle has
770  *	the usage count incremented and the caller must use dev_put() to
771  *	release it when it is no longer needed. %NULL is returned if no
772  *	matching device is found.
773  */
774 
775 struct net_device *dev_get_by_name(struct net *net, const char *name)
776 {
777 	struct net_device *dev;
778 
779 	rcu_read_lock();
780 	dev = dev_get_by_name_rcu(net, name);
781 	dev_hold(dev);
782 	rcu_read_unlock();
783 	return dev;
784 }
785 EXPORT_SYMBOL(dev_get_by_name);
786 
787 /**
788  *	__dev_get_by_index - find a device by its ifindex
789  *	@net: the applicable net namespace
790  *	@ifindex: index of device
791  *
792  *	Search for an interface by index. Returns %NULL if the device
793  *	is not found or a pointer to the device. The device has not
794  *	had its reference counter increased so the caller must be careful
795  *	about locking. The caller must hold either the RTNL semaphore
796  *	or @dev_base_lock.
797  */
798 
799 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
800 {
801 	struct net_device *dev;
802 	struct hlist_head *head = dev_index_hash(net, ifindex);
803 
804 	hlist_for_each_entry(dev, head, index_hlist)
805 		if (dev->ifindex == ifindex)
806 			return dev;
807 
808 	return NULL;
809 }
810 EXPORT_SYMBOL(__dev_get_by_index);
811 
812 /**
813  *	dev_get_by_index_rcu - find a device by its ifindex
814  *	@net: the applicable net namespace
815  *	@ifindex: index of device
816  *
817  *	Search for an interface by index. Returns %NULL if the device
818  *	is not found or a pointer to the device. The device has not
819  *	had its reference counter increased so the caller must be careful
820  *	about locking. The caller must hold RCU lock.
821  */
822 
823 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
824 {
825 	struct net_device *dev;
826 	struct hlist_head *head = dev_index_hash(net, ifindex);
827 
828 	hlist_for_each_entry_rcu(dev, head, index_hlist)
829 		if (dev->ifindex == ifindex)
830 			return dev;
831 
832 	return NULL;
833 }
834 EXPORT_SYMBOL(dev_get_by_index_rcu);
835 
836 
837 /**
838  *	dev_get_by_index - find a device by its ifindex
839  *	@net: the applicable net namespace
840  *	@ifindex: index of device
841  *
842  *	Search for an interface by index. Returns NULL if the device
843  *	is not found or a pointer to the device. The device returned has
844  *	had a reference added and the pointer is safe until the user calls
845  *	dev_put to indicate they have finished with it.
846  */
847 
848 struct net_device *dev_get_by_index(struct net *net, int ifindex)
849 {
850 	struct net_device *dev;
851 
852 	rcu_read_lock();
853 	dev = dev_get_by_index_rcu(net, ifindex);
854 	dev_hold(dev);
855 	rcu_read_unlock();
856 	return dev;
857 }
858 EXPORT_SYMBOL(dev_get_by_index);
859 
860 /**
861  *	dev_get_by_napi_id - find a device by napi_id
862  *	@napi_id: ID of the NAPI struct
863  *
864  *	Search for an interface by NAPI ID. Returns %NULL if the device
865  *	is not found or a pointer to the device. The device has not had
866  *	its reference counter increased so the caller must be careful
867  *	about locking. The caller must hold RCU lock.
868  */
869 
870 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
871 {
872 	struct napi_struct *napi;
873 
874 	WARN_ON_ONCE(!rcu_read_lock_held());
875 
876 	if (napi_id < MIN_NAPI_ID)
877 		return NULL;
878 
879 	napi = napi_by_id(napi_id);
880 
881 	return napi ? napi->dev : NULL;
882 }
883 EXPORT_SYMBOL(dev_get_by_napi_id);
884 
885 /**
886  *	netdev_get_name - get a netdevice name, knowing its ifindex.
887  *	@net: network namespace
888  *	@name: a pointer to the buffer where the name will be stored.
889  *	@ifindex: the ifindex of the interface to get the name from.
890  */
891 int netdev_get_name(struct net *net, char *name, int ifindex)
892 {
893 	struct net_device *dev;
894 	int ret;
895 
896 	down_read(&devnet_rename_sem);
897 	rcu_read_lock();
898 
899 	dev = dev_get_by_index_rcu(net, ifindex);
900 	if (!dev) {
901 		ret = -ENODEV;
902 		goto out;
903 	}
904 
905 	strcpy(name, dev->name);
906 
907 	ret = 0;
908 out:
909 	rcu_read_unlock();
910 	up_read(&devnet_rename_sem);
911 	return ret;
912 }
913 
914 /**
915  *	dev_getbyhwaddr_rcu - find a device by its hardware address
916  *	@net: the applicable net namespace
917  *	@type: media type of device
918  *	@ha: hardware address
919  *
920  *	Search for an interface by MAC address. Returns NULL if the device
921  *	is not found or a pointer to the device.
922  *	The caller must hold RCU or RTNL.
923  *	The returned device has not had its ref count increased
924  *	and the caller must therefore be careful about locking
925  *
926  */
927 
928 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
929 				       const char *ha)
930 {
931 	struct net_device *dev;
932 
933 	for_each_netdev_rcu(net, dev)
934 		if (dev->type == type &&
935 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
936 			return dev;
937 
938 	return NULL;
939 }
940 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
941 
942 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
943 {
944 	struct net_device *dev, *ret = NULL;
945 
946 	rcu_read_lock();
947 	for_each_netdev_rcu(net, dev)
948 		if (dev->type == type) {
949 			dev_hold(dev);
950 			ret = dev;
951 			break;
952 		}
953 	rcu_read_unlock();
954 	return ret;
955 }
956 EXPORT_SYMBOL(dev_getfirstbyhwtype);
957 
958 /**
959  *	__dev_get_by_flags - find any device with given flags
960  *	@net: the applicable net namespace
961  *	@if_flags: IFF_* values
962  *	@mask: bitmask of bits in if_flags to check
963  *
964  *	Search for any interface with the given flags. Returns NULL if a device
965  *	is not found or a pointer to the device. Must be called inside
966  *	rtnl_lock(), and result refcount is unchanged.
967  */
968 
969 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
970 				      unsigned short mask)
971 {
972 	struct net_device *dev, *ret;
973 
974 	ASSERT_RTNL();
975 
976 	ret = NULL;
977 	for_each_netdev(net, dev) {
978 		if (((dev->flags ^ if_flags) & mask) == 0) {
979 			ret = dev;
980 			break;
981 		}
982 	}
983 	return ret;
984 }
985 EXPORT_SYMBOL(__dev_get_by_flags);
986 
987 /**
988  *	dev_valid_name - check if name is okay for network device
989  *	@name: name string
990  *
991  *	Network device names need to be valid file names to
992  *	allow sysfs to work.  We also disallow any kind of
993  *	whitespace.
994  */
995 bool dev_valid_name(const char *name)
996 {
997 	if (*name == '\0')
998 		return false;
999 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1000 		return false;
1001 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1002 		return false;
1003 
1004 	while (*name) {
1005 		if (*name == '/' || *name == ':' || isspace(*name))
1006 			return false;
1007 		name++;
1008 	}
1009 	return true;
1010 }
1011 EXPORT_SYMBOL(dev_valid_name);
1012 
1013 /**
1014  *	__dev_alloc_name - allocate a name for a device
1015  *	@net: network namespace to allocate the device name in
1016  *	@name: name format string
1017  *	@buf:  scratch buffer and result name string
1018  *
1019  *	Passed a format string - eg "lt%d" it will try and find a suitable
1020  *	id. It scans list of devices to build up a free map, then chooses
1021  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1022  *	while allocating the name and adding the device in order to avoid
1023  *	duplicates.
1024  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1025  *	Returns the number of the unit assigned or a negative errno code.
1026  */
1027 
1028 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1029 {
1030 	int i = 0;
1031 	const char *p;
1032 	const int max_netdevices = 8*PAGE_SIZE;
1033 	unsigned long *inuse;
1034 	struct net_device *d;
1035 
1036 	if (!dev_valid_name(name))
1037 		return -EINVAL;
1038 
1039 	p = strchr(name, '%');
1040 	if (p) {
1041 		/*
1042 		 * Verify the string as this thing may have come from
1043 		 * the user.  There must be either one "%d" and no other "%"
1044 		 * characters.
1045 		 */
1046 		if (p[1] != 'd' || strchr(p + 2, '%'))
1047 			return -EINVAL;
1048 
1049 		/* Use one page as a bit array of possible slots */
1050 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1051 		if (!inuse)
1052 			return -ENOMEM;
1053 
1054 		for_each_netdev(net, d) {
1055 			struct netdev_name_node *name_node;
1056 			list_for_each_entry(name_node, &d->name_node->list, list) {
1057 				if (!sscanf(name_node->name, name, &i))
1058 					continue;
1059 				if (i < 0 || i >= max_netdevices)
1060 					continue;
1061 
1062 				/*  avoid cases where sscanf is not exact inverse of printf */
1063 				snprintf(buf, IFNAMSIZ, name, i);
1064 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1065 					__set_bit(i, inuse);
1066 			}
1067 			if (!sscanf(d->name, name, &i))
1068 				continue;
1069 			if (i < 0 || i >= max_netdevices)
1070 				continue;
1071 
1072 			/*  avoid cases where sscanf is not exact inverse of printf */
1073 			snprintf(buf, IFNAMSIZ, name, i);
1074 			if (!strncmp(buf, d->name, IFNAMSIZ))
1075 				__set_bit(i, inuse);
1076 		}
1077 
1078 		i = find_first_zero_bit(inuse, max_netdevices);
1079 		free_page((unsigned long) inuse);
1080 	}
1081 
1082 	snprintf(buf, IFNAMSIZ, name, i);
1083 	if (!netdev_name_in_use(net, buf))
1084 		return i;
1085 
1086 	/* It is possible to run out of possible slots
1087 	 * when the name is long and there isn't enough space left
1088 	 * for the digits, or if all bits are used.
1089 	 */
1090 	return -ENFILE;
1091 }
1092 
1093 static int dev_alloc_name_ns(struct net *net,
1094 			     struct net_device *dev,
1095 			     const char *name)
1096 {
1097 	char buf[IFNAMSIZ];
1098 	int ret;
1099 
1100 	BUG_ON(!net);
1101 	ret = __dev_alloc_name(net, name, buf);
1102 	if (ret >= 0)
1103 		strscpy(dev->name, buf, IFNAMSIZ);
1104 	return ret;
1105 }
1106 
1107 /**
1108  *	dev_alloc_name - allocate a name for a device
1109  *	@dev: device
1110  *	@name: name format string
1111  *
1112  *	Passed a format string - eg "lt%d" it will try and find a suitable
1113  *	id. It scans list of devices to build up a free map, then chooses
1114  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1115  *	while allocating the name and adding the device in order to avoid
1116  *	duplicates.
1117  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1118  *	Returns the number of the unit assigned or a negative errno code.
1119  */
1120 
1121 int dev_alloc_name(struct net_device *dev, const char *name)
1122 {
1123 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1124 }
1125 EXPORT_SYMBOL(dev_alloc_name);
1126 
1127 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1128 			      const char *name)
1129 {
1130 	BUG_ON(!net);
1131 
1132 	if (!dev_valid_name(name))
1133 		return -EINVAL;
1134 
1135 	if (strchr(name, '%'))
1136 		return dev_alloc_name_ns(net, dev, name);
1137 	else if (netdev_name_in_use(net, name))
1138 		return -EEXIST;
1139 	else if (dev->name != name)
1140 		strscpy(dev->name, name, IFNAMSIZ);
1141 
1142 	return 0;
1143 }
1144 
1145 /**
1146  *	dev_change_name - change name of a device
1147  *	@dev: device
1148  *	@newname: name (or format string) must be at least IFNAMSIZ
1149  *
1150  *	Change name of a device, can pass format strings "eth%d".
1151  *	for wildcarding.
1152  */
1153 int dev_change_name(struct net_device *dev, const char *newname)
1154 {
1155 	unsigned char old_assign_type;
1156 	char oldname[IFNAMSIZ];
1157 	int err = 0;
1158 	int ret;
1159 	struct net *net;
1160 
1161 	ASSERT_RTNL();
1162 	BUG_ON(!dev_net(dev));
1163 
1164 	net = dev_net(dev);
1165 
1166 	down_write(&devnet_rename_sem);
1167 
1168 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1169 		up_write(&devnet_rename_sem);
1170 		return 0;
1171 	}
1172 
1173 	memcpy(oldname, dev->name, IFNAMSIZ);
1174 
1175 	err = dev_get_valid_name(net, dev, newname);
1176 	if (err < 0) {
1177 		up_write(&devnet_rename_sem);
1178 		return err;
1179 	}
1180 
1181 	if (oldname[0] && !strchr(oldname, '%'))
1182 		netdev_info(dev, "renamed from %s%s\n", oldname,
1183 			    dev->flags & IFF_UP ? " (while UP)" : "");
1184 
1185 	old_assign_type = dev->name_assign_type;
1186 	dev->name_assign_type = NET_NAME_RENAMED;
1187 
1188 rollback:
1189 	ret = device_rename(&dev->dev, dev->name);
1190 	if (ret) {
1191 		memcpy(dev->name, oldname, IFNAMSIZ);
1192 		dev->name_assign_type = old_assign_type;
1193 		up_write(&devnet_rename_sem);
1194 		return ret;
1195 	}
1196 
1197 	up_write(&devnet_rename_sem);
1198 
1199 	netdev_adjacent_rename_links(dev, oldname);
1200 
1201 	write_lock(&dev_base_lock);
1202 	netdev_name_node_del(dev->name_node);
1203 	write_unlock(&dev_base_lock);
1204 
1205 	synchronize_rcu();
1206 
1207 	write_lock(&dev_base_lock);
1208 	netdev_name_node_add(net, dev->name_node);
1209 	write_unlock(&dev_base_lock);
1210 
1211 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1212 	ret = notifier_to_errno(ret);
1213 
1214 	if (ret) {
1215 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1216 		if (err >= 0) {
1217 			err = ret;
1218 			down_write(&devnet_rename_sem);
1219 			memcpy(dev->name, oldname, IFNAMSIZ);
1220 			memcpy(oldname, newname, IFNAMSIZ);
1221 			dev->name_assign_type = old_assign_type;
1222 			old_assign_type = NET_NAME_RENAMED;
1223 			goto rollback;
1224 		} else {
1225 			netdev_err(dev, "name change rollback failed: %d\n",
1226 				   ret);
1227 		}
1228 	}
1229 
1230 	return err;
1231 }
1232 
1233 /**
1234  *	dev_set_alias - change ifalias of a device
1235  *	@dev: device
1236  *	@alias: name up to IFALIASZ
1237  *	@len: limit of bytes to copy from info
1238  *
1239  *	Set ifalias for a device,
1240  */
1241 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1242 {
1243 	struct dev_ifalias *new_alias = NULL;
1244 
1245 	if (len >= IFALIASZ)
1246 		return -EINVAL;
1247 
1248 	if (len) {
1249 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1250 		if (!new_alias)
1251 			return -ENOMEM;
1252 
1253 		memcpy(new_alias->ifalias, alias, len);
1254 		new_alias->ifalias[len] = 0;
1255 	}
1256 
1257 	mutex_lock(&ifalias_mutex);
1258 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1259 					mutex_is_locked(&ifalias_mutex));
1260 	mutex_unlock(&ifalias_mutex);
1261 
1262 	if (new_alias)
1263 		kfree_rcu(new_alias, rcuhead);
1264 
1265 	return len;
1266 }
1267 EXPORT_SYMBOL(dev_set_alias);
1268 
1269 /**
1270  *	dev_get_alias - get ifalias of a device
1271  *	@dev: device
1272  *	@name: buffer to store name of ifalias
1273  *	@len: size of buffer
1274  *
1275  *	get ifalias for a device.  Caller must make sure dev cannot go
1276  *	away,  e.g. rcu read lock or own a reference count to device.
1277  */
1278 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1279 {
1280 	const struct dev_ifalias *alias;
1281 	int ret = 0;
1282 
1283 	rcu_read_lock();
1284 	alias = rcu_dereference(dev->ifalias);
1285 	if (alias)
1286 		ret = snprintf(name, len, "%s", alias->ifalias);
1287 	rcu_read_unlock();
1288 
1289 	return ret;
1290 }
1291 
1292 /**
1293  *	netdev_features_change - device changes features
1294  *	@dev: device to cause notification
1295  *
1296  *	Called to indicate a device has changed features.
1297  */
1298 void netdev_features_change(struct net_device *dev)
1299 {
1300 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1301 }
1302 EXPORT_SYMBOL(netdev_features_change);
1303 
1304 /**
1305  *	netdev_state_change - device changes state
1306  *	@dev: device to cause notification
1307  *
1308  *	Called to indicate a device has changed state. This function calls
1309  *	the notifier chains for netdev_chain and sends a NEWLINK message
1310  *	to the routing socket.
1311  */
1312 void netdev_state_change(struct net_device *dev)
1313 {
1314 	if (dev->flags & IFF_UP) {
1315 		struct netdev_notifier_change_info change_info = {
1316 			.info.dev = dev,
1317 		};
1318 
1319 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1320 					      &change_info.info);
1321 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1322 	}
1323 }
1324 EXPORT_SYMBOL(netdev_state_change);
1325 
1326 /**
1327  * __netdev_notify_peers - notify network peers about existence of @dev,
1328  * to be called when rtnl lock is already held.
1329  * @dev: network device
1330  *
1331  * Generate traffic such that interested network peers are aware of
1332  * @dev, such as by generating a gratuitous ARP. This may be used when
1333  * a device wants to inform the rest of the network about some sort of
1334  * reconfiguration such as a failover event or virtual machine
1335  * migration.
1336  */
1337 void __netdev_notify_peers(struct net_device *dev)
1338 {
1339 	ASSERT_RTNL();
1340 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1341 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1342 }
1343 EXPORT_SYMBOL(__netdev_notify_peers);
1344 
1345 /**
1346  * netdev_notify_peers - notify network peers about existence of @dev
1347  * @dev: network device
1348  *
1349  * Generate traffic such that interested network peers are aware of
1350  * @dev, such as by generating a gratuitous ARP. This may be used when
1351  * a device wants to inform the rest of the network about some sort of
1352  * reconfiguration such as a failover event or virtual machine
1353  * migration.
1354  */
1355 void netdev_notify_peers(struct net_device *dev)
1356 {
1357 	rtnl_lock();
1358 	__netdev_notify_peers(dev);
1359 	rtnl_unlock();
1360 }
1361 EXPORT_SYMBOL(netdev_notify_peers);
1362 
1363 static int napi_threaded_poll(void *data);
1364 
1365 static int napi_kthread_create(struct napi_struct *n)
1366 {
1367 	int err = 0;
1368 
1369 	/* Create and wake up the kthread once to put it in
1370 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1371 	 * warning and work with loadavg.
1372 	 */
1373 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1374 				n->dev->name, n->napi_id);
1375 	if (IS_ERR(n->thread)) {
1376 		err = PTR_ERR(n->thread);
1377 		pr_err("kthread_run failed with err %d\n", err);
1378 		n->thread = NULL;
1379 	}
1380 
1381 	return err;
1382 }
1383 
1384 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1385 {
1386 	const struct net_device_ops *ops = dev->netdev_ops;
1387 	int ret;
1388 
1389 	ASSERT_RTNL();
1390 	dev_addr_check(dev);
1391 
1392 	if (!netif_device_present(dev)) {
1393 		/* may be detached because parent is runtime-suspended */
1394 		if (dev->dev.parent)
1395 			pm_runtime_resume(dev->dev.parent);
1396 		if (!netif_device_present(dev))
1397 			return -ENODEV;
1398 	}
1399 
1400 	/* Block netpoll from trying to do any rx path servicing.
1401 	 * If we don't do this there is a chance ndo_poll_controller
1402 	 * or ndo_poll may be running while we open the device
1403 	 */
1404 	netpoll_poll_disable(dev);
1405 
1406 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1407 	ret = notifier_to_errno(ret);
1408 	if (ret)
1409 		return ret;
1410 
1411 	set_bit(__LINK_STATE_START, &dev->state);
1412 
1413 	if (ops->ndo_validate_addr)
1414 		ret = ops->ndo_validate_addr(dev);
1415 
1416 	if (!ret && ops->ndo_open)
1417 		ret = ops->ndo_open(dev);
1418 
1419 	netpoll_poll_enable(dev);
1420 
1421 	if (ret)
1422 		clear_bit(__LINK_STATE_START, &dev->state);
1423 	else {
1424 		dev->flags |= IFF_UP;
1425 		dev_set_rx_mode(dev);
1426 		dev_activate(dev);
1427 		add_device_randomness(dev->dev_addr, dev->addr_len);
1428 	}
1429 
1430 	return ret;
1431 }
1432 
1433 /**
1434  *	dev_open	- prepare an interface for use.
1435  *	@dev: device to open
1436  *	@extack: netlink extended ack
1437  *
1438  *	Takes a device from down to up state. The device's private open
1439  *	function is invoked and then the multicast lists are loaded. Finally
1440  *	the device is moved into the up state and a %NETDEV_UP message is
1441  *	sent to the netdev notifier chain.
1442  *
1443  *	Calling this function on an active interface is a nop. On a failure
1444  *	a negative errno code is returned.
1445  */
1446 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1447 {
1448 	int ret;
1449 
1450 	if (dev->flags & IFF_UP)
1451 		return 0;
1452 
1453 	ret = __dev_open(dev, extack);
1454 	if (ret < 0)
1455 		return ret;
1456 
1457 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1458 	call_netdevice_notifiers(NETDEV_UP, dev);
1459 
1460 	return ret;
1461 }
1462 EXPORT_SYMBOL(dev_open);
1463 
1464 static void __dev_close_many(struct list_head *head)
1465 {
1466 	struct net_device *dev;
1467 
1468 	ASSERT_RTNL();
1469 	might_sleep();
1470 
1471 	list_for_each_entry(dev, head, close_list) {
1472 		/* Temporarily disable netpoll until the interface is down */
1473 		netpoll_poll_disable(dev);
1474 
1475 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1476 
1477 		clear_bit(__LINK_STATE_START, &dev->state);
1478 
1479 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1480 		 * can be even on different cpu. So just clear netif_running().
1481 		 *
1482 		 * dev->stop() will invoke napi_disable() on all of it's
1483 		 * napi_struct instances on this device.
1484 		 */
1485 		smp_mb__after_atomic(); /* Commit netif_running(). */
1486 	}
1487 
1488 	dev_deactivate_many(head);
1489 
1490 	list_for_each_entry(dev, head, close_list) {
1491 		const struct net_device_ops *ops = dev->netdev_ops;
1492 
1493 		/*
1494 		 *	Call the device specific close. This cannot fail.
1495 		 *	Only if device is UP
1496 		 *
1497 		 *	We allow it to be called even after a DETACH hot-plug
1498 		 *	event.
1499 		 */
1500 		if (ops->ndo_stop)
1501 			ops->ndo_stop(dev);
1502 
1503 		dev->flags &= ~IFF_UP;
1504 		netpoll_poll_enable(dev);
1505 	}
1506 }
1507 
1508 static void __dev_close(struct net_device *dev)
1509 {
1510 	LIST_HEAD(single);
1511 
1512 	list_add(&dev->close_list, &single);
1513 	__dev_close_many(&single);
1514 	list_del(&single);
1515 }
1516 
1517 void dev_close_many(struct list_head *head, bool unlink)
1518 {
1519 	struct net_device *dev, *tmp;
1520 
1521 	/* Remove the devices that don't need to be closed */
1522 	list_for_each_entry_safe(dev, tmp, head, close_list)
1523 		if (!(dev->flags & IFF_UP))
1524 			list_del_init(&dev->close_list);
1525 
1526 	__dev_close_many(head);
1527 
1528 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1529 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1530 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1531 		if (unlink)
1532 			list_del_init(&dev->close_list);
1533 	}
1534 }
1535 EXPORT_SYMBOL(dev_close_many);
1536 
1537 /**
1538  *	dev_close - shutdown an interface.
1539  *	@dev: device to shutdown
1540  *
1541  *	This function moves an active device into down state. A
1542  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1543  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1544  *	chain.
1545  */
1546 void dev_close(struct net_device *dev)
1547 {
1548 	if (dev->flags & IFF_UP) {
1549 		LIST_HEAD(single);
1550 
1551 		list_add(&dev->close_list, &single);
1552 		dev_close_many(&single, true);
1553 		list_del(&single);
1554 	}
1555 }
1556 EXPORT_SYMBOL(dev_close);
1557 
1558 
1559 /**
1560  *	dev_disable_lro - disable Large Receive Offload on a device
1561  *	@dev: device
1562  *
1563  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1564  *	called under RTNL.  This is needed if received packets may be
1565  *	forwarded to another interface.
1566  */
1567 void dev_disable_lro(struct net_device *dev)
1568 {
1569 	struct net_device *lower_dev;
1570 	struct list_head *iter;
1571 
1572 	dev->wanted_features &= ~NETIF_F_LRO;
1573 	netdev_update_features(dev);
1574 
1575 	if (unlikely(dev->features & NETIF_F_LRO))
1576 		netdev_WARN(dev, "failed to disable LRO!\n");
1577 
1578 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1579 		dev_disable_lro(lower_dev);
1580 }
1581 EXPORT_SYMBOL(dev_disable_lro);
1582 
1583 /**
1584  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1585  *	@dev: device
1586  *
1587  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1588  *	called under RTNL.  This is needed if Generic XDP is installed on
1589  *	the device.
1590  */
1591 static void dev_disable_gro_hw(struct net_device *dev)
1592 {
1593 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1594 	netdev_update_features(dev);
1595 
1596 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1597 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1598 }
1599 
1600 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1601 {
1602 #define N(val) 						\
1603 	case NETDEV_##val:				\
1604 		return "NETDEV_" __stringify(val);
1605 	switch (cmd) {
1606 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1607 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1608 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1609 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1610 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1611 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1612 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1613 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1614 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1615 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1616 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1617 	}
1618 #undef N
1619 	return "UNKNOWN_NETDEV_EVENT";
1620 }
1621 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1622 
1623 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1624 				   struct net_device *dev)
1625 {
1626 	struct netdev_notifier_info info = {
1627 		.dev = dev,
1628 	};
1629 
1630 	return nb->notifier_call(nb, val, &info);
1631 }
1632 
1633 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1634 					     struct net_device *dev)
1635 {
1636 	int err;
1637 
1638 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1639 	err = notifier_to_errno(err);
1640 	if (err)
1641 		return err;
1642 
1643 	if (!(dev->flags & IFF_UP))
1644 		return 0;
1645 
1646 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1647 	return 0;
1648 }
1649 
1650 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1651 						struct net_device *dev)
1652 {
1653 	if (dev->flags & IFF_UP) {
1654 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1655 					dev);
1656 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1657 	}
1658 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1659 }
1660 
1661 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1662 						 struct net *net)
1663 {
1664 	struct net_device *dev;
1665 	int err;
1666 
1667 	for_each_netdev(net, dev) {
1668 		err = call_netdevice_register_notifiers(nb, dev);
1669 		if (err)
1670 			goto rollback;
1671 	}
1672 	return 0;
1673 
1674 rollback:
1675 	for_each_netdev_continue_reverse(net, dev)
1676 		call_netdevice_unregister_notifiers(nb, dev);
1677 	return err;
1678 }
1679 
1680 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1681 						    struct net *net)
1682 {
1683 	struct net_device *dev;
1684 
1685 	for_each_netdev(net, dev)
1686 		call_netdevice_unregister_notifiers(nb, dev);
1687 }
1688 
1689 static int dev_boot_phase = 1;
1690 
1691 /**
1692  * register_netdevice_notifier - register a network notifier block
1693  * @nb: notifier
1694  *
1695  * Register a notifier to be called when network device events occur.
1696  * The notifier passed is linked into the kernel structures and must
1697  * not be reused until it has been unregistered. A negative errno code
1698  * is returned on a failure.
1699  *
1700  * When registered all registration and up events are replayed
1701  * to the new notifier to allow device to have a race free
1702  * view of the network device list.
1703  */
1704 
1705 int register_netdevice_notifier(struct notifier_block *nb)
1706 {
1707 	struct net *net;
1708 	int err;
1709 
1710 	/* Close race with setup_net() and cleanup_net() */
1711 	down_write(&pernet_ops_rwsem);
1712 	rtnl_lock();
1713 	err = raw_notifier_chain_register(&netdev_chain, nb);
1714 	if (err)
1715 		goto unlock;
1716 	if (dev_boot_phase)
1717 		goto unlock;
1718 	for_each_net(net) {
1719 		err = call_netdevice_register_net_notifiers(nb, net);
1720 		if (err)
1721 			goto rollback;
1722 	}
1723 
1724 unlock:
1725 	rtnl_unlock();
1726 	up_write(&pernet_ops_rwsem);
1727 	return err;
1728 
1729 rollback:
1730 	for_each_net_continue_reverse(net)
1731 		call_netdevice_unregister_net_notifiers(nb, net);
1732 
1733 	raw_notifier_chain_unregister(&netdev_chain, nb);
1734 	goto unlock;
1735 }
1736 EXPORT_SYMBOL(register_netdevice_notifier);
1737 
1738 /**
1739  * unregister_netdevice_notifier - unregister a network notifier block
1740  * @nb: notifier
1741  *
1742  * Unregister a notifier previously registered by
1743  * register_netdevice_notifier(). The notifier is unlinked into the
1744  * kernel structures and may then be reused. A negative errno code
1745  * is returned on a failure.
1746  *
1747  * After unregistering unregister and down device events are synthesized
1748  * for all devices on the device list to the removed notifier to remove
1749  * the need for special case cleanup code.
1750  */
1751 
1752 int unregister_netdevice_notifier(struct notifier_block *nb)
1753 {
1754 	struct net *net;
1755 	int err;
1756 
1757 	/* Close race with setup_net() and cleanup_net() */
1758 	down_write(&pernet_ops_rwsem);
1759 	rtnl_lock();
1760 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1761 	if (err)
1762 		goto unlock;
1763 
1764 	for_each_net(net)
1765 		call_netdevice_unregister_net_notifiers(nb, net);
1766 
1767 unlock:
1768 	rtnl_unlock();
1769 	up_write(&pernet_ops_rwsem);
1770 	return err;
1771 }
1772 EXPORT_SYMBOL(unregister_netdevice_notifier);
1773 
1774 static int __register_netdevice_notifier_net(struct net *net,
1775 					     struct notifier_block *nb,
1776 					     bool ignore_call_fail)
1777 {
1778 	int err;
1779 
1780 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1781 	if (err)
1782 		return err;
1783 	if (dev_boot_phase)
1784 		return 0;
1785 
1786 	err = call_netdevice_register_net_notifiers(nb, net);
1787 	if (err && !ignore_call_fail)
1788 		goto chain_unregister;
1789 
1790 	return 0;
1791 
1792 chain_unregister:
1793 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1794 	return err;
1795 }
1796 
1797 static int __unregister_netdevice_notifier_net(struct net *net,
1798 					       struct notifier_block *nb)
1799 {
1800 	int err;
1801 
1802 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1803 	if (err)
1804 		return err;
1805 
1806 	call_netdevice_unregister_net_notifiers(nb, net);
1807 	return 0;
1808 }
1809 
1810 /**
1811  * register_netdevice_notifier_net - register a per-netns network notifier block
1812  * @net: network namespace
1813  * @nb: notifier
1814  *
1815  * Register a notifier to be called when network device events occur.
1816  * The notifier passed is linked into the kernel structures and must
1817  * not be reused until it has been unregistered. A negative errno code
1818  * is returned on a failure.
1819  *
1820  * When registered all registration and up events are replayed
1821  * to the new notifier to allow device to have a race free
1822  * view of the network device list.
1823  */
1824 
1825 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1826 {
1827 	int err;
1828 
1829 	rtnl_lock();
1830 	err = __register_netdevice_notifier_net(net, nb, false);
1831 	rtnl_unlock();
1832 	return err;
1833 }
1834 EXPORT_SYMBOL(register_netdevice_notifier_net);
1835 
1836 /**
1837  * unregister_netdevice_notifier_net - unregister a per-netns
1838  *                                     network notifier block
1839  * @net: network namespace
1840  * @nb: notifier
1841  *
1842  * Unregister a notifier previously registered by
1843  * register_netdevice_notifier(). The notifier is unlinked into the
1844  * kernel structures and may then be reused. A negative errno code
1845  * is returned on a failure.
1846  *
1847  * After unregistering unregister and down device events are synthesized
1848  * for all devices on the device list to the removed notifier to remove
1849  * the need for special case cleanup code.
1850  */
1851 
1852 int unregister_netdevice_notifier_net(struct net *net,
1853 				      struct notifier_block *nb)
1854 {
1855 	int err;
1856 
1857 	rtnl_lock();
1858 	err = __unregister_netdevice_notifier_net(net, nb);
1859 	rtnl_unlock();
1860 	return err;
1861 }
1862 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1863 
1864 static void __move_netdevice_notifier_net(struct net *src_net,
1865 					  struct net *dst_net,
1866 					  struct notifier_block *nb)
1867 {
1868 	__unregister_netdevice_notifier_net(src_net, nb);
1869 	__register_netdevice_notifier_net(dst_net, nb, true);
1870 }
1871 
1872 void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
1873 				 struct notifier_block *nb)
1874 {
1875 	rtnl_lock();
1876 	__move_netdevice_notifier_net(src_net, dst_net, nb);
1877 	rtnl_unlock();
1878 }
1879 
1880 int register_netdevice_notifier_dev_net(struct net_device *dev,
1881 					struct notifier_block *nb,
1882 					struct netdev_net_notifier *nn)
1883 {
1884 	int err;
1885 
1886 	rtnl_lock();
1887 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1888 	if (!err) {
1889 		nn->nb = nb;
1890 		list_add(&nn->list, &dev->net_notifier_list);
1891 	}
1892 	rtnl_unlock();
1893 	return err;
1894 }
1895 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1896 
1897 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1898 					  struct notifier_block *nb,
1899 					  struct netdev_net_notifier *nn)
1900 {
1901 	int err;
1902 
1903 	rtnl_lock();
1904 	list_del(&nn->list);
1905 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1906 	rtnl_unlock();
1907 	return err;
1908 }
1909 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1910 
1911 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1912 					     struct net *net)
1913 {
1914 	struct netdev_net_notifier *nn;
1915 
1916 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1917 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1918 }
1919 
1920 /**
1921  *	call_netdevice_notifiers_info - call all network notifier blocks
1922  *	@val: value passed unmodified to notifier function
1923  *	@info: notifier information data
1924  *
1925  *	Call all network notifier blocks.  Parameters and return value
1926  *	are as for raw_notifier_call_chain().
1927  */
1928 
1929 static int call_netdevice_notifiers_info(unsigned long val,
1930 					 struct netdev_notifier_info *info)
1931 {
1932 	struct net *net = dev_net(info->dev);
1933 	int ret;
1934 
1935 	ASSERT_RTNL();
1936 
1937 	/* Run per-netns notifier block chain first, then run the global one.
1938 	 * Hopefully, one day, the global one is going to be removed after
1939 	 * all notifier block registrators get converted to be per-netns.
1940 	 */
1941 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1942 	if (ret & NOTIFY_STOP_MASK)
1943 		return ret;
1944 	return raw_notifier_call_chain(&netdev_chain, val, info);
1945 }
1946 
1947 /**
1948  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1949  *	                                       for and rollback on error
1950  *	@val_up: value passed unmodified to notifier function
1951  *	@val_down: value passed unmodified to the notifier function when
1952  *	           recovering from an error on @val_up
1953  *	@info: notifier information data
1954  *
1955  *	Call all per-netns network notifier blocks, but not notifier blocks on
1956  *	the global notifier chain. Parameters and return value are as for
1957  *	raw_notifier_call_chain_robust().
1958  */
1959 
1960 static int
1961 call_netdevice_notifiers_info_robust(unsigned long val_up,
1962 				     unsigned long val_down,
1963 				     struct netdev_notifier_info *info)
1964 {
1965 	struct net *net = dev_net(info->dev);
1966 
1967 	ASSERT_RTNL();
1968 
1969 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1970 					      val_up, val_down, info);
1971 }
1972 
1973 static int call_netdevice_notifiers_extack(unsigned long val,
1974 					   struct net_device *dev,
1975 					   struct netlink_ext_ack *extack)
1976 {
1977 	struct netdev_notifier_info info = {
1978 		.dev = dev,
1979 		.extack = extack,
1980 	};
1981 
1982 	return call_netdevice_notifiers_info(val, &info);
1983 }
1984 
1985 /**
1986  *	call_netdevice_notifiers - call all network notifier blocks
1987  *      @val: value passed unmodified to notifier function
1988  *      @dev: net_device pointer passed unmodified to notifier function
1989  *
1990  *	Call all network notifier blocks.  Parameters and return value
1991  *	are as for raw_notifier_call_chain().
1992  */
1993 
1994 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1995 {
1996 	return call_netdevice_notifiers_extack(val, dev, NULL);
1997 }
1998 EXPORT_SYMBOL(call_netdevice_notifiers);
1999 
2000 /**
2001  *	call_netdevice_notifiers_mtu - call all network notifier blocks
2002  *	@val: value passed unmodified to notifier function
2003  *	@dev: net_device pointer passed unmodified to notifier function
2004  *	@arg: additional u32 argument passed to the notifier function
2005  *
2006  *	Call all network notifier blocks.  Parameters and return value
2007  *	are as for raw_notifier_call_chain().
2008  */
2009 static int call_netdevice_notifiers_mtu(unsigned long val,
2010 					struct net_device *dev, u32 arg)
2011 {
2012 	struct netdev_notifier_info_ext info = {
2013 		.info.dev = dev,
2014 		.ext.mtu = arg,
2015 	};
2016 
2017 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2018 
2019 	return call_netdevice_notifiers_info(val, &info.info);
2020 }
2021 
2022 #ifdef CONFIG_NET_INGRESS
2023 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2024 
2025 void net_inc_ingress_queue(void)
2026 {
2027 	static_branch_inc(&ingress_needed_key);
2028 }
2029 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2030 
2031 void net_dec_ingress_queue(void)
2032 {
2033 	static_branch_dec(&ingress_needed_key);
2034 }
2035 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2036 #endif
2037 
2038 #ifdef CONFIG_NET_EGRESS
2039 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2040 
2041 void net_inc_egress_queue(void)
2042 {
2043 	static_branch_inc(&egress_needed_key);
2044 }
2045 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2046 
2047 void net_dec_egress_queue(void)
2048 {
2049 	static_branch_dec(&egress_needed_key);
2050 }
2051 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2052 #endif
2053 
2054 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2055 EXPORT_SYMBOL(netstamp_needed_key);
2056 #ifdef CONFIG_JUMP_LABEL
2057 static atomic_t netstamp_needed_deferred;
2058 static atomic_t netstamp_wanted;
2059 static void netstamp_clear(struct work_struct *work)
2060 {
2061 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2062 	int wanted;
2063 
2064 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2065 	if (wanted > 0)
2066 		static_branch_enable(&netstamp_needed_key);
2067 	else
2068 		static_branch_disable(&netstamp_needed_key);
2069 }
2070 static DECLARE_WORK(netstamp_work, netstamp_clear);
2071 #endif
2072 
2073 void net_enable_timestamp(void)
2074 {
2075 #ifdef CONFIG_JUMP_LABEL
2076 	int wanted = atomic_read(&netstamp_wanted);
2077 
2078 	while (wanted > 0) {
2079 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2080 			return;
2081 	}
2082 	atomic_inc(&netstamp_needed_deferred);
2083 	schedule_work(&netstamp_work);
2084 #else
2085 	static_branch_inc(&netstamp_needed_key);
2086 #endif
2087 }
2088 EXPORT_SYMBOL(net_enable_timestamp);
2089 
2090 void net_disable_timestamp(void)
2091 {
2092 #ifdef CONFIG_JUMP_LABEL
2093 	int wanted = atomic_read(&netstamp_wanted);
2094 
2095 	while (wanted > 1) {
2096 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2097 			return;
2098 	}
2099 	atomic_dec(&netstamp_needed_deferred);
2100 	schedule_work(&netstamp_work);
2101 #else
2102 	static_branch_dec(&netstamp_needed_key);
2103 #endif
2104 }
2105 EXPORT_SYMBOL(net_disable_timestamp);
2106 
2107 static inline void net_timestamp_set(struct sk_buff *skb)
2108 {
2109 	skb->tstamp = 0;
2110 	skb->mono_delivery_time = 0;
2111 	if (static_branch_unlikely(&netstamp_needed_key))
2112 		skb->tstamp = ktime_get_real();
2113 }
2114 
2115 #define net_timestamp_check(COND, SKB)				\
2116 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2117 		if ((COND) && !(SKB)->tstamp)			\
2118 			(SKB)->tstamp = ktime_get_real();	\
2119 	}							\
2120 
2121 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2122 {
2123 	return __is_skb_forwardable(dev, skb, true);
2124 }
2125 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2126 
2127 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2128 			      bool check_mtu)
2129 {
2130 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2131 
2132 	if (likely(!ret)) {
2133 		skb->protocol = eth_type_trans(skb, dev);
2134 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2135 	}
2136 
2137 	return ret;
2138 }
2139 
2140 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2141 {
2142 	return __dev_forward_skb2(dev, skb, true);
2143 }
2144 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2145 
2146 /**
2147  * dev_forward_skb - loopback an skb to another netif
2148  *
2149  * @dev: destination network device
2150  * @skb: buffer to forward
2151  *
2152  * return values:
2153  *	NET_RX_SUCCESS	(no congestion)
2154  *	NET_RX_DROP     (packet was dropped, but freed)
2155  *
2156  * dev_forward_skb can be used for injecting an skb from the
2157  * start_xmit function of one device into the receive queue
2158  * of another device.
2159  *
2160  * The receiving device may be in another namespace, so
2161  * we have to clear all information in the skb that could
2162  * impact namespace isolation.
2163  */
2164 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2165 {
2166 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2167 }
2168 EXPORT_SYMBOL_GPL(dev_forward_skb);
2169 
2170 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2171 {
2172 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2173 }
2174 
2175 static inline int deliver_skb(struct sk_buff *skb,
2176 			      struct packet_type *pt_prev,
2177 			      struct net_device *orig_dev)
2178 {
2179 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2180 		return -ENOMEM;
2181 	refcount_inc(&skb->users);
2182 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2183 }
2184 
2185 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2186 					  struct packet_type **pt,
2187 					  struct net_device *orig_dev,
2188 					  __be16 type,
2189 					  struct list_head *ptype_list)
2190 {
2191 	struct packet_type *ptype, *pt_prev = *pt;
2192 
2193 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2194 		if (ptype->type != type)
2195 			continue;
2196 		if (pt_prev)
2197 			deliver_skb(skb, pt_prev, orig_dev);
2198 		pt_prev = ptype;
2199 	}
2200 	*pt = pt_prev;
2201 }
2202 
2203 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2204 {
2205 	if (!ptype->af_packet_priv || !skb->sk)
2206 		return false;
2207 
2208 	if (ptype->id_match)
2209 		return ptype->id_match(ptype, skb->sk);
2210 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2211 		return true;
2212 
2213 	return false;
2214 }
2215 
2216 /**
2217  * dev_nit_active - return true if any network interface taps are in use
2218  *
2219  * @dev: network device to check for the presence of taps
2220  */
2221 bool dev_nit_active(struct net_device *dev)
2222 {
2223 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2224 }
2225 EXPORT_SYMBOL_GPL(dev_nit_active);
2226 
2227 /*
2228  *	Support routine. Sends outgoing frames to any network
2229  *	taps currently in use.
2230  */
2231 
2232 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2233 {
2234 	struct packet_type *ptype;
2235 	struct sk_buff *skb2 = NULL;
2236 	struct packet_type *pt_prev = NULL;
2237 	struct list_head *ptype_list = &ptype_all;
2238 
2239 	rcu_read_lock();
2240 again:
2241 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2242 		if (ptype->ignore_outgoing)
2243 			continue;
2244 
2245 		/* Never send packets back to the socket
2246 		 * they originated from - MvS (miquels@drinkel.ow.org)
2247 		 */
2248 		if (skb_loop_sk(ptype, skb))
2249 			continue;
2250 
2251 		if (pt_prev) {
2252 			deliver_skb(skb2, pt_prev, skb->dev);
2253 			pt_prev = ptype;
2254 			continue;
2255 		}
2256 
2257 		/* need to clone skb, done only once */
2258 		skb2 = skb_clone(skb, GFP_ATOMIC);
2259 		if (!skb2)
2260 			goto out_unlock;
2261 
2262 		net_timestamp_set(skb2);
2263 
2264 		/* skb->nh should be correctly
2265 		 * set by sender, so that the second statement is
2266 		 * just protection against buggy protocols.
2267 		 */
2268 		skb_reset_mac_header(skb2);
2269 
2270 		if (skb_network_header(skb2) < skb2->data ||
2271 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2272 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2273 					     ntohs(skb2->protocol),
2274 					     dev->name);
2275 			skb_reset_network_header(skb2);
2276 		}
2277 
2278 		skb2->transport_header = skb2->network_header;
2279 		skb2->pkt_type = PACKET_OUTGOING;
2280 		pt_prev = ptype;
2281 	}
2282 
2283 	if (ptype_list == &ptype_all) {
2284 		ptype_list = &dev->ptype_all;
2285 		goto again;
2286 	}
2287 out_unlock:
2288 	if (pt_prev) {
2289 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2290 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2291 		else
2292 			kfree_skb(skb2);
2293 	}
2294 	rcu_read_unlock();
2295 }
2296 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2297 
2298 /**
2299  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2300  * @dev: Network device
2301  * @txq: number of queues available
2302  *
2303  * If real_num_tx_queues is changed the tc mappings may no longer be
2304  * valid. To resolve this verify the tc mapping remains valid and if
2305  * not NULL the mapping. With no priorities mapping to this
2306  * offset/count pair it will no longer be used. In the worst case TC0
2307  * is invalid nothing can be done so disable priority mappings. If is
2308  * expected that drivers will fix this mapping if they can before
2309  * calling netif_set_real_num_tx_queues.
2310  */
2311 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2312 {
2313 	int i;
2314 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2315 
2316 	/* If TC0 is invalidated disable TC mapping */
2317 	if (tc->offset + tc->count > txq) {
2318 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2319 		dev->num_tc = 0;
2320 		return;
2321 	}
2322 
2323 	/* Invalidated prio to tc mappings set to TC0 */
2324 	for (i = 1; i < TC_BITMASK + 1; i++) {
2325 		int q = netdev_get_prio_tc_map(dev, i);
2326 
2327 		tc = &dev->tc_to_txq[q];
2328 		if (tc->offset + tc->count > txq) {
2329 			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",
2330 				    i, q);
2331 			netdev_set_prio_tc_map(dev, i, 0);
2332 		}
2333 	}
2334 }
2335 
2336 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2337 {
2338 	if (dev->num_tc) {
2339 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2340 		int i;
2341 
2342 		/* walk through the TCs and see if it falls into any of them */
2343 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2344 			if ((txq - tc->offset) < tc->count)
2345 				return i;
2346 		}
2347 
2348 		/* didn't find it, just return -1 to indicate no match */
2349 		return -1;
2350 	}
2351 
2352 	return 0;
2353 }
2354 EXPORT_SYMBOL(netdev_txq_to_tc);
2355 
2356 #ifdef CONFIG_XPS
2357 static struct static_key xps_needed __read_mostly;
2358 static struct static_key xps_rxqs_needed __read_mostly;
2359 static DEFINE_MUTEX(xps_map_mutex);
2360 #define xmap_dereference(P)		\
2361 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2362 
2363 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2364 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2365 {
2366 	struct xps_map *map = NULL;
2367 	int pos;
2368 
2369 	if (dev_maps)
2370 		map = xmap_dereference(dev_maps->attr_map[tci]);
2371 	if (!map)
2372 		return false;
2373 
2374 	for (pos = map->len; pos--;) {
2375 		if (map->queues[pos] != index)
2376 			continue;
2377 
2378 		if (map->len > 1) {
2379 			map->queues[pos] = map->queues[--map->len];
2380 			break;
2381 		}
2382 
2383 		if (old_maps)
2384 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2385 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2386 		kfree_rcu(map, rcu);
2387 		return false;
2388 	}
2389 
2390 	return true;
2391 }
2392 
2393 static bool remove_xps_queue_cpu(struct net_device *dev,
2394 				 struct xps_dev_maps *dev_maps,
2395 				 int cpu, u16 offset, u16 count)
2396 {
2397 	int num_tc = dev_maps->num_tc;
2398 	bool active = false;
2399 	int tci;
2400 
2401 	for (tci = cpu * num_tc; num_tc--; tci++) {
2402 		int i, j;
2403 
2404 		for (i = count, j = offset; i--; j++) {
2405 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2406 				break;
2407 		}
2408 
2409 		active |= i < 0;
2410 	}
2411 
2412 	return active;
2413 }
2414 
2415 static void reset_xps_maps(struct net_device *dev,
2416 			   struct xps_dev_maps *dev_maps,
2417 			   enum xps_map_type type)
2418 {
2419 	static_key_slow_dec_cpuslocked(&xps_needed);
2420 	if (type == XPS_RXQS)
2421 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2422 
2423 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2424 
2425 	kfree_rcu(dev_maps, rcu);
2426 }
2427 
2428 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2429 			   u16 offset, u16 count)
2430 {
2431 	struct xps_dev_maps *dev_maps;
2432 	bool active = false;
2433 	int i, j;
2434 
2435 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2436 	if (!dev_maps)
2437 		return;
2438 
2439 	for (j = 0; j < dev_maps->nr_ids; j++)
2440 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2441 	if (!active)
2442 		reset_xps_maps(dev, dev_maps, type);
2443 
2444 	if (type == XPS_CPUS) {
2445 		for (i = offset + (count - 1); count--; i--)
2446 			netdev_queue_numa_node_write(
2447 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2448 	}
2449 }
2450 
2451 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2452 				   u16 count)
2453 {
2454 	if (!static_key_false(&xps_needed))
2455 		return;
2456 
2457 	cpus_read_lock();
2458 	mutex_lock(&xps_map_mutex);
2459 
2460 	if (static_key_false(&xps_rxqs_needed))
2461 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2462 
2463 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2464 
2465 	mutex_unlock(&xps_map_mutex);
2466 	cpus_read_unlock();
2467 }
2468 
2469 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2470 {
2471 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2472 }
2473 
2474 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2475 				      u16 index, bool is_rxqs_map)
2476 {
2477 	struct xps_map *new_map;
2478 	int alloc_len = XPS_MIN_MAP_ALLOC;
2479 	int i, pos;
2480 
2481 	for (pos = 0; map && pos < map->len; pos++) {
2482 		if (map->queues[pos] != index)
2483 			continue;
2484 		return map;
2485 	}
2486 
2487 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2488 	if (map) {
2489 		if (pos < map->alloc_len)
2490 			return map;
2491 
2492 		alloc_len = map->alloc_len * 2;
2493 	}
2494 
2495 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2496 	 *  map
2497 	 */
2498 	if (is_rxqs_map)
2499 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2500 	else
2501 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2502 				       cpu_to_node(attr_index));
2503 	if (!new_map)
2504 		return NULL;
2505 
2506 	for (i = 0; i < pos; i++)
2507 		new_map->queues[i] = map->queues[i];
2508 	new_map->alloc_len = alloc_len;
2509 	new_map->len = pos;
2510 
2511 	return new_map;
2512 }
2513 
2514 /* Copy xps maps at a given index */
2515 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2516 			      struct xps_dev_maps *new_dev_maps, int index,
2517 			      int tc, bool skip_tc)
2518 {
2519 	int i, tci = index * dev_maps->num_tc;
2520 	struct xps_map *map;
2521 
2522 	/* copy maps belonging to foreign traffic classes */
2523 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2524 		if (i == tc && skip_tc)
2525 			continue;
2526 
2527 		/* fill in the new device map from the old device map */
2528 		map = xmap_dereference(dev_maps->attr_map[tci]);
2529 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2530 	}
2531 }
2532 
2533 /* Must be called under cpus_read_lock */
2534 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2535 			  u16 index, enum xps_map_type type)
2536 {
2537 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2538 	const unsigned long *online_mask = NULL;
2539 	bool active = false, copy = false;
2540 	int i, j, tci, numa_node_id = -2;
2541 	int maps_sz, num_tc = 1, tc = 0;
2542 	struct xps_map *map, *new_map;
2543 	unsigned int nr_ids;
2544 
2545 	if (dev->num_tc) {
2546 		/* Do not allow XPS on subordinate device directly */
2547 		num_tc = dev->num_tc;
2548 		if (num_tc < 0)
2549 			return -EINVAL;
2550 
2551 		/* If queue belongs to subordinate dev use its map */
2552 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2553 
2554 		tc = netdev_txq_to_tc(dev, index);
2555 		if (tc < 0)
2556 			return -EINVAL;
2557 	}
2558 
2559 	mutex_lock(&xps_map_mutex);
2560 
2561 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2562 	if (type == XPS_RXQS) {
2563 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2564 		nr_ids = dev->num_rx_queues;
2565 	} else {
2566 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2567 		if (num_possible_cpus() > 1)
2568 			online_mask = cpumask_bits(cpu_online_mask);
2569 		nr_ids = nr_cpu_ids;
2570 	}
2571 
2572 	if (maps_sz < L1_CACHE_BYTES)
2573 		maps_sz = L1_CACHE_BYTES;
2574 
2575 	/* The old dev_maps could be larger or smaller than the one we're
2576 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2577 	 * between. We could try to be smart, but let's be safe instead and only
2578 	 * copy foreign traffic classes if the two map sizes match.
2579 	 */
2580 	if (dev_maps &&
2581 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2582 		copy = true;
2583 
2584 	/* allocate memory for queue storage */
2585 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2586 	     j < nr_ids;) {
2587 		if (!new_dev_maps) {
2588 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2589 			if (!new_dev_maps) {
2590 				mutex_unlock(&xps_map_mutex);
2591 				return -ENOMEM;
2592 			}
2593 
2594 			new_dev_maps->nr_ids = nr_ids;
2595 			new_dev_maps->num_tc = num_tc;
2596 		}
2597 
2598 		tci = j * num_tc + tc;
2599 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2600 
2601 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2602 		if (!map)
2603 			goto error;
2604 
2605 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2606 	}
2607 
2608 	if (!new_dev_maps)
2609 		goto out_no_new_maps;
2610 
2611 	if (!dev_maps) {
2612 		/* Increment static keys at most once per type */
2613 		static_key_slow_inc_cpuslocked(&xps_needed);
2614 		if (type == XPS_RXQS)
2615 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2616 	}
2617 
2618 	for (j = 0; j < nr_ids; j++) {
2619 		bool skip_tc = false;
2620 
2621 		tci = j * num_tc + tc;
2622 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2623 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2624 			/* add tx-queue to CPU/rx-queue maps */
2625 			int pos = 0;
2626 
2627 			skip_tc = true;
2628 
2629 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2630 			while ((pos < map->len) && (map->queues[pos] != index))
2631 				pos++;
2632 
2633 			if (pos == map->len)
2634 				map->queues[map->len++] = index;
2635 #ifdef CONFIG_NUMA
2636 			if (type == XPS_CPUS) {
2637 				if (numa_node_id == -2)
2638 					numa_node_id = cpu_to_node(j);
2639 				else if (numa_node_id != cpu_to_node(j))
2640 					numa_node_id = -1;
2641 			}
2642 #endif
2643 		}
2644 
2645 		if (copy)
2646 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2647 					  skip_tc);
2648 	}
2649 
2650 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2651 
2652 	/* Cleanup old maps */
2653 	if (!dev_maps)
2654 		goto out_no_old_maps;
2655 
2656 	for (j = 0; j < dev_maps->nr_ids; j++) {
2657 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2658 			map = xmap_dereference(dev_maps->attr_map[tci]);
2659 			if (!map)
2660 				continue;
2661 
2662 			if (copy) {
2663 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2664 				if (map == new_map)
2665 					continue;
2666 			}
2667 
2668 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2669 			kfree_rcu(map, rcu);
2670 		}
2671 	}
2672 
2673 	old_dev_maps = dev_maps;
2674 
2675 out_no_old_maps:
2676 	dev_maps = new_dev_maps;
2677 	active = true;
2678 
2679 out_no_new_maps:
2680 	if (type == XPS_CPUS)
2681 		/* update Tx queue numa node */
2682 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2683 					     (numa_node_id >= 0) ?
2684 					     numa_node_id : NUMA_NO_NODE);
2685 
2686 	if (!dev_maps)
2687 		goto out_no_maps;
2688 
2689 	/* removes tx-queue from unused CPUs/rx-queues */
2690 	for (j = 0; j < dev_maps->nr_ids; j++) {
2691 		tci = j * dev_maps->num_tc;
2692 
2693 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2694 			if (i == tc &&
2695 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2696 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2697 				continue;
2698 
2699 			active |= remove_xps_queue(dev_maps,
2700 						   copy ? old_dev_maps : NULL,
2701 						   tci, index);
2702 		}
2703 	}
2704 
2705 	if (old_dev_maps)
2706 		kfree_rcu(old_dev_maps, rcu);
2707 
2708 	/* free map if not active */
2709 	if (!active)
2710 		reset_xps_maps(dev, dev_maps, type);
2711 
2712 out_no_maps:
2713 	mutex_unlock(&xps_map_mutex);
2714 
2715 	return 0;
2716 error:
2717 	/* remove any maps that we added */
2718 	for (j = 0; j < nr_ids; j++) {
2719 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2720 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2721 			map = copy ?
2722 			      xmap_dereference(dev_maps->attr_map[tci]) :
2723 			      NULL;
2724 			if (new_map && new_map != map)
2725 				kfree(new_map);
2726 		}
2727 	}
2728 
2729 	mutex_unlock(&xps_map_mutex);
2730 
2731 	kfree(new_dev_maps);
2732 	return -ENOMEM;
2733 }
2734 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2735 
2736 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2737 			u16 index)
2738 {
2739 	int ret;
2740 
2741 	cpus_read_lock();
2742 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2743 	cpus_read_unlock();
2744 
2745 	return ret;
2746 }
2747 EXPORT_SYMBOL(netif_set_xps_queue);
2748 
2749 #endif
2750 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2751 {
2752 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2753 
2754 	/* Unbind any subordinate channels */
2755 	while (txq-- != &dev->_tx[0]) {
2756 		if (txq->sb_dev)
2757 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2758 	}
2759 }
2760 
2761 void netdev_reset_tc(struct net_device *dev)
2762 {
2763 #ifdef CONFIG_XPS
2764 	netif_reset_xps_queues_gt(dev, 0);
2765 #endif
2766 	netdev_unbind_all_sb_channels(dev);
2767 
2768 	/* Reset TC configuration of device */
2769 	dev->num_tc = 0;
2770 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2771 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2772 }
2773 EXPORT_SYMBOL(netdev_reset_tc);
2774 
2775 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2776 {
2777 	if (tc >= dev->num_tc)
2778 		return -EINVAL;
2779 
2780 #ifdef CONFIG_XPS
2781 	netif_reset_xps_queues(dev, offset, count);
2782 #endif
2783 	dev->tc_to_txq[tc].count = count;
2784 	dev->tc_to_txq[tc].offset = offset;
2785 	return 0;
2786 }
2787 EXPORT_SYMBOL(netdev_set_tc_queue);
2788 
2789 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2790 {
2791 	if (num_tc > TC_MAX_QUEUE)
2792 		return -EINVAL;
2793 
2794 #ifdef CONFIG_XPS
2795 	netif_reset_xps_queues_gt(dev, 0);
2796 #endif
2797 	netdev_unbind_all_sb_channels(dev);
2798 
2799 	dev->num_tc = num_tc;
2800 	return 0;
2801 }
2802 EXPORT_SYMBOL(netdev_set_num_tc);
2803 
2804 void netdev_unbind_sb_channel(struct net_device *dev,
2805 			      struct net_device *sb_dev)
2806 {
2807 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2808 
2809 #ifdef CONFIG_XPS
2810 	netif_reset_xps_queues_gt(sb_dev, 0);
2811 #endif
2812 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2813 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2814 
2815 	while (txq-- != &dev->_tx[0]) {
2816 		if (txq->sb_dev == sb_dev)
2817 			txq->sb_dev = NULL;
2818 	}
2819 }
2820 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2821 
2822 int netdev_bind_sb_channel_queue(struct net_device *dev,
2823 				 struct net_device *sb_dev,
2824 				 u8 tc, u16 count, u16 offset)
2825 {
2826 	/* Make certain the sb_dev and dev are already configured */
2827 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2828 		return -EINVAL;
2829 
2830 	/* We cannot hand out queues we don't have */
2831 	if ((offset + count) > dev->real_num_tx_queues)
2832 		return -EINVAL;
2833 
2834 	/* Record the mapping */
2835 	sb_dev->tc_to_txq[tc].count = count;
2836 	sb_dev->tc_to_txq[tc].offset = offset;
2837 
2838 	/* Provide a way for Tx queue to find the tc_to_txq map or
2839 	 * XPS map for itself.
2840 	 */
2841 	while (count--)
2842 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2843 
2844 	return 0;
2845 }
2846 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2847 
2848 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2849 {
2850 	/* Do not use a multiqueue device to represent a subordinate channel */
2851 	if (netif_is_multiqueue(dev))
2852 		return -ENODEV;
2853 
2854 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2855 	 * Channel 0 is meant to be "native" mode and used only to represent
2856 	 * the main root device. We allow writing 0 to reset the device back
2857 	 * to normal mode after being used as a subordinate channel.
2858 	 */
2859 	if (channel > S16_MAX)
2860 		return -EINVAL;
2861 
2862 	dev->num_tc = -channel;
2863 
2864 	return 0;
2865 }
2866 EXPORT_SYMBOL(netdev_set_sb_channel);
2867 
2868 /*
2869  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2870  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2871  */
2872 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2873 {
2874 	bool disabling;
2875 	int rc;
2876 
2877 	disabling = txq < dev->real_num_tx_queues;
2878 
2879 	if (txq < 1 || txq > dev->num_tx_queues)
2880 		return -EINVAL;
2881 
2882 	if (dev->reg_state == NETREG_REGISTERED ||
2883 	    dev->reg_state == NETREG_UNREGISTERING) {
2884 		ASSERT_RTNL();
2885 
2886 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2887 						  txq);
2888 		if (rc)
2889 			return rc;
2890 
2891 		if (dev->num_tc)
2892 			netif_setup_tc(dev, txq);
2893 
2894 		dev_qdisc_change_real_num_tx(dev, txq);
2895 
2896 		dev->real_num_tx_queues = txq;
2897 
2898 		if (disabling) {
2899 			synchronize_net();
2900 			qdisc_reset_all_tx_gt(dev, txq);
2901 #ifdef CONFIG_XPS
2902 			netif_reset_xps_queues_gt(dev, txq);
2903 #endif
2904 		}
2905 	} else {
2906 		dev->real_num_tx_queues = txq;
2907 	}
2908 
2909 	return 0;
2910 }
2911 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2912 
2913 #ifdef CONFIG_SYSFS
2914 /**
2915  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2916  *	@dev: Network device
2917  *	@rxq: Actual number of RX queues
2918  *
2919  *	This must be called either with the rtnl_lock held or before
2920  *	registration of the net device.  Returns 0 on success, or a
2921  *	negative error code.  If called before registration, it always
2922  *	succeeds.
2923  */
2924 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2925 {
2926 	int rc;
2927 
2928 	if (rxq < 1 || rxq > dev->num_rx_queues)
2929 		return -EINVAL;
2930 
2931 	if (dev->reg_state == NETREG_REGISTERED) {
2932 		ASSERT_RTNL();
2933 
2934 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2935 						  rxq);
2936 		if (rc)
2937 			return rc;
2938 	}
2939 
2940 	dev->real_num_rx_queues = rxq;
2941 	return 0;
2942 }
2943 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2944 #endif
2945 
2946 /**
2947  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2948  *	@dev: Network device
2949  *	@txq: Actual number of TX queues
2950  *	@rxq: Actual number of RX queues
2951  *
2952  *	Set the real number of both TX and RX queues.
2953  *	Does nothing if the number of queues is already correct.
2954  */
2955 int netif_set_real_num_queues(struct net_device *dev,
2956 			      unsigned int txq, unsigned int rxq)
2957 {
2958 	unsigned int old_rxq = dev->real_num_rx_queues;
2959 	int err;
2960 
2961 	if (txq < 1 || txq > dev->num_tx_queues ||
2962 	    rxq < 1 || rxq > dev->num_rx_queues)
2963 		return -EINVAL;
2964 
2965 	/* Start from increases, so the error path only does decreases -
2966 	 * decreases can't fail.
2967 	 */
2968 	if (rxq > dev->real_num_rx_queues) {
2969 		err = netif_set_real_num_rx_queues(dev, rxq);
2970 		if (err)
2971 			return err;
2972 	}
2973 	if (txq > dev->real_num_tx_queues) {
2974 		err = netif_set_real_num_tx_queues(dev, txq);
2975 		if (err)
2976 			goto undo_rx;
2977 	}
2978 	if (rxq < dev->real_num_rx_queues)
2979 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2980 	if (txq < dev->real_num_tx_queues)
2981 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2982 
2983 	return 0;
2984 undo_rx:
2985 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2986 	return err;
2987 }
2988 EXPORT_SYMBOL(netif_set_real_num_queues);
2989 
2990 /**
2991  * netif_set_tso_max_size() - set the max size of TSO frames supported
2992  * @dev:	netdev to update
2993  * @size:	max skb->len of a TSO frame
2994  *
2995  * Set the limit on the size of TSO super-frames the device can handle.
2996  * Unless explicitly set the stack will assume the value of
2997  * %GSO_LEGACY_MAX_SIZE.
2998  */
2999 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3000 {
3001 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
3002 	if (size < READ_ONCE(dev->gso_max_size))
3003 		netif_set_gso_max_size(dev, size);
3004 }
3005 EXPORT_SYMBOL(netif_set_tso_max_size);
3006 
3007 /**
3008  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3009  * @dev:	netdev to update
3010  * @segs:	max number of TCP segments
3011  *
3012  * Set the limit on the number of TCP segments the device can generate from
3013  * a single TSO super-frame.
3014  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3015  */
3016 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3017 {
3018 	dev->tso_max_segs = segs;
3019 	if (segs < READ_ONCE(dev->gso_max_segs))
3020 		netif_set_gso_max_segs(dev, segs);
3021 }
3022 EXPORT_SYMBOL(netif_set_tso_max_segs);
3023 
3024 /**
3025  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3026  * @to:		netdev to update
3027  * @from:	netdev from which to copy the limits
3028  */
3029 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3030 {
3031 	netif_set_tso_max_size(to, from->tso_max_size);
3032 	netif_set_tso_max_segs(to, from->tso_max_segs);
3033 }
3034 EXPORT_SYMBOL(netif_inherit_tso_max);
3035 
3036 /**
3037  * netif_get_num_default_rss_queues - default number of RSS queues
3038  *
3039  * Default value is the number of physical cores if there are only 1 or 2, or
3040  * divided by 2 if there are more.
3041  */
3042 int netif_get_num_default_rss_queues(void)
3043 {
3044 	cpumask_var_t cpus;
3045 	int cpu, count = 0;
3046 
3047 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3048 		return 1;
3049 
3050 	cpumask_copy(cpus, cpu_online_mask);
3051 	for_each_cpu(cpu, cpus) {
3052 		++count;
3053 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3054 	}
3055 	free_cpumask_var(cpus);
3056 
3057 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3058 }
3059 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3060 
3061 static void __netif_reschedule(struct Qdisc *q)
3062 {
3063 	struct softnet_data *sd;
3064 	unsigned long flags;
3065 
3066 	local_irq_save(flags);
3067 	sd = this_cpu_ptr(&softnet_data);
3068 	q->next_sched = NULL;
3069 	*sd->output_queue_tailp = q;
3070 	sd->output_queue_tailp = &q->next_sched;
3071 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3072 	local_irq_restore(flags);
3073 }
3074 
3075 void __netif_schedule(struct Qdisc *q)
3076 {
3077 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3078 		__netif_reschedule(q);
3079 }
3080 EXPORT_SYMBOL(__netif_schedule);
3081 
3082 struct dev_kfree_skb_cb {
3083 	enum skb_free_reason reason;
3084 };
3085 
3086 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3087 {
3088 	return (struct dev_kfree_skb_cb *)skb->cb;
3089 }
3090 
3091 void netif_schedule_queue(struct netdev_queue *txq)
3092 {
3093 	rcu_read_lock();
3094 	if (!netif_xmit_stopped(txq)) {
3095 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3096 
3097 		__netif_schedule(q);
3098 	}
3099 	rcu_read_unlock();
3100 }
3101 EXPORT_SYMBOL(netif_schedule_queue);
3102 
3103 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3104 {
3105 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3106 		struct Qdisc *q;
3107 
3108 		rcu_read_lock();
3109 		q = rcu_dereference(dev_queue->qdisc);
3110 		__netif_schedule(q);
3111 		rcu_read_unlock();
3112 	}
3113 }
3114 EXPORT_SYMBOL(netif_tx_wake_queue);
3115 
3116 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
3117 {
3118 	unsigned long flags;
3119 
3120 	if (unlikely(!skb))
3121 		return;
3122 
3123 	if (likely(refcount_read(&skb->users) == 1)) {
3124 		smp_rmb();
3125 		refcount_set(&skb->users, 0);
3126 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3127 		return;
3128 	}
3129 	get_kfree_skb_cb(skb)->reason = reason;
3130 	local_irq_save(flags);
3131 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3132 	__this_cpu_write(softnet_data.completion_queue, skb);
3133 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3134 	local_irq_restore(flags);
3135 }
3136 EXPORT_SYMBOL(__dev_kfree_skb_irq);
3137 
3138 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
3139 {
3140 	if (in_hardirq() || irqs_disabled())
3141 		__dev_kfree_skb_irq(skb, reason);
3142 	else
3143 		dev_kfree_skb(skb);
3144 }
3145 EXPORT_SYMBOL(__dev_kfree_skb_any);
3146 
3147 
3148 /**
3149  * netif_device_detach - mark device as removed
3150  * @dev: network device
3151  *
3152  * Mark device as removed from system and therefore no longer available.
3153  */
3154 void netif_device_detach(struct net_device *dev)
3155 {
3156 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3157 	    netif_running(dev)) {
3158 		netif_tx_stop_all_queues(dev);
3159 	}
3160 }
3161 EXPORT_SYMBOL(netif_device_detach);
3162 
3163 /**
3164  * netif_device_attach - mark device as attached
3165  * @dev: network device
3166  *
3167  * Mark device as attached from system and restart if needed.
3168  */
3169 void netif_device_attach(struct net_device *dev)
3170 {
3171 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3172 	    netif_running(dev)) {
3173 		netif_tx_wake_all_queues(dev);
3174 		__netdev_watchdog_up(dev);
3175 	}
3176 }
3177 EXPORT_SYMBOL(netif_device_attach);
3178 
3179 /*
3180  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3181  * to be used as a distribution range.
3182  */
3183 static u16 skb_tx_hash(const struct net_device *dev,
3184 		       const struct net_device *sb_dev,
3185 		       struct sk_buff *skb)
3186 {
3187 	u32 hash;
3188 	u16 qoffset = 0;
3189 	u16 qcount = dev->real_num_tx_queues;
3190 
3191 	if (dev->num_tc) {
3192 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3193 
3194 		qoffset = sb_dev->tc_to_txq[tc].offset;
3195 		qcount = sb_dev->tc_to_txq[tc].count;
3196 		if (unlikely(!qcount)) {
3197 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3198 					     sb_dev->name, qoffset, tc);
3199 			qoffset = 0;
3200 			qcount = dev->real_num_tx_queues;
3201 		}
3202 	}
3203 
3204 	if (skb_rx_queue_recorded(skb)) {
3205 		hash = skb_get_rx_queue(skb);
3206 		if (hash >= qoffset)
3207 			hash -= qoffset;
3208 		while (unlikely(hash >= qcount))
3209 			hash -= qcount;
3210 		return hash + qoffset;
3211 	}
3212 
3213 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3214 }
3215 
3216 static void skb_warn_bad_offload(const struct sk_buff *skb)
3217 {
3218 	static const netdev_features_t null_features;
3219 	struct net_device *dev = skb->dev;
3220 	const char *name = "";
3221 
3222 	if (!net_ratelimit())
3223 		return;
3224 
3225 	if (dev) {
3226 		if (dev->dev.parent)
3227 			name = dev_driver_string(dev->dev.parent);
3228 		else
3229 			name = netdev_name(dev);
3230 	}
3231 	skb_dump(KERN_WARNING, skb, false);
3232 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3233 	     name, dev ? &dev->features : &null_features,
3234 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3235 }
3236 
3237 /*
3238  * Invalidate hardware checksum when packet is to be mangled, and
3239  * complete checksum manually on outgoing path.
3240  */
3241 int skb_checksum_help(struct sk_buff *skb)
3242 {
3243 	__wsum csum;
3244 	int ret = 0, offset;
3245 
3246 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3247 		goto out_set_summed;
3248 
3249 	if (unlikely(skb_is_gso(skb))) {
3250 		skb_warn_bad_offload(skb);
3251 		return -EINVAL;
3252 	}
3253 
3254 	/* Before computing a checksum, we should make sure no frag could
3255 	 * be modified by an external entity : checksum could be wrong.
3256 	 */
3257 	if (skb_has_shared_frag(skb)) {
3258 		ret = __skb_linearize(skb);
3259 		if (ret)
3260 			goto out;
3261 	}
3262 
3263 	offset = skb_checksum_start_offset(skb);
3264 	ret = -EINVAL;
3265 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3266 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3267 		goto out;
3268 	}
3269 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3270 
3271 	offset += skb->csum_offset;
3272 	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3273 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3274 		goto out;
3275 	}
3276 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3277 	if (ret)
3278 		goto out;
3279 
3280 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3281 out_set_summed:
3282 	skb->ip_summed = CHECKSUM_NONE;
3283 out:
3284 	return ret;
3285 }
3286 EXPORT_SYMBOL(skb_checksum_help);
3287 
3288 int skb_crc32c_csum_help(struct sk_buff *skb)
3289 {
3290 	__le32 crc32c_csum;
3291 	int ret = 0, offset, start;
3292 
3293 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3294 		goto out;
3295 
3296 	if (unlikely(skb_is_gso(skb)))
3297 		goto out;
3298 
3299 	/* Before computing a checksum, we should make sure no frag could
3300 	 * be modified by an external entity : checksum could be wrong.
3301 	 */
3302 	if (unlikely(skb_has_shared_frag(skb))) {
3303 		ret = __skb_linearize(skb);
3304 		if (ret)
3305 			goto out;
3306 	}
3307 	start = skb_checksum_start_offset(skb);
3308 	offset = start + offsetof(struct sctphdr, checksum);
3309 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3310 		ret = -EINVAL;
3311 		goto out;
3312 	}
3313 
3314 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3315 	if (ret)
3316 		goto out;
3317 
3318 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3319 						  skb->len - start, ~(__u32)0,
3320 						  crc32c_csum_stub));
3321 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3322 	skb->ip_summed = CHECKSUM_NONE;
3323 	skb->csum_not_inet = 0;
3324 out:
3325 	return ret;
3326 }
3327 
3328 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3329 {
3330 	__be16 type = skb->protocol;
3331 
3332 	/* Tunnel gso handlers can set protocol to ethernet. */
3333 	if (type == htons(ETH_P_TEB)) {
3334 		struct ethhdr *eth;
3335 
3336 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3337 			return 0;
3338 
3339 		eth = (struct ethhdr *)skb->data;
3340 		type = eth->h_proto;
3341 	}
3342 
3343 	return __vlan_get_protocol(skb, type, depth);
3344 }
3345 
3346 /* openvswitch calls this on rx path, so we need a different check.
3347  */
3348 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3349 {
3350 	if (tx_path)
3351 		return skb->ip_summed != CHECKSUM_PARTIAL &&
3352 		       skb->ip_summed != CHECKSUM_UNNECESSARY;
3353 
3354 	return skb->ip_summed == CHECKSUM_NONE;
3355 }
3356 
3357 /**
3358  *	__skb_gso_segment - Perform segmentation on skb.
3359  *	@skb: buffer to segment
3360  *	@features: features for the output path (see dev->features)
3361  *	@tx_path: whether it is called in TX path
3362  *
3363  *	This function segments the given skb and returns a list of segments.
3364  *
3365  *	It may return NULL if the skb requires no segmentation.  This is
3366  *	only possible when GSO is used for verifying header integrity.
3367  *
3368  *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3369  */
3370 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3371 				  netdev_features_t features, bool tx_path)
3372 {
3373 	struct sk_buff *segs;
3374 
3375 	if (unlikely(skb_needs_check(skb, tx_path))) {
3376 		int err;
3377 
3378 		/* We're going to init ->check field in TCP or UDP header */
3379 		err = skb_cow_head(skb, 0);
3380 		if (err < 0)
3381 			return ERR_PTR(err);
3382 	}
3383 
3384 	/* Only report GSO partial support if it will enable us to
3385 	 * support segmentation on this frame without needing additional
3386 	 * work.
3387 	 */
3388 	if (features & NETIF_F_GSO_PARTIAL) {
3389 		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3390 		struct net_device *dev = skb->dev;
3391 
3392 		partial_features |= dev->features & dev->gso_partial_features;
3393 		if (!skb_gso_ok(skb, features | partial_features))
3394 			features &= ~NETIF_F_GSO_PARTIAL;
3395 	}
3396 
3397 	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3398 		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3399 
3400 	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3401 	SKB_GSO_CB(skb)->encap_level = 0;
3402 
3403 	skb_reset_mac_header(skb);
3404 	skb_reset_mac_len(skb);
3405 
3406 	segs = skb_mac_gso_segment(skb, features);
3407 
3408 	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3409 		skb_warn_bad_offload(skb);
3410 
3411 	return segs;
3412 }
3413 EXPORT_SYMBOL(__skb_gso_segment);
3414 
3415 /* Take action when hardware reception checksum errors are detected. */
3416 #ifdef CONFIG_BUG
3417 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3418 {
3419 	netdev_err(dev, "hw csum failure\n");
3420 	skb_dump(KERN_ERR, skb, true);
3421 	dump_stack();
3422 }
3423 
3424 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3425 {
3426 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3427 }
3428 EXPORT_SYMBOL(netdev_rx_csum_fault);
3429 #endif
3430 
3431 /* XXX: check that highmem exists at all on the given machine. */
3432 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3433 {
3434 #ifdef CONFIG_HIGHMEM
3435 	int i;
3436 
3437 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3438 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3439 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3440 
3441 			if (PageHighMem(skb_frag_page(frag)))
3442 				return 1;
3443 		}
3444 	}
3445 #endif
3446 	return 0;
3447 }
3448 
3449 /* If MPLS offload request, verify we are testing hardware MPLS features
3450  * instead of standard features for the netdev.
3451  */
3452 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3453 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3454 					   netdev_features_t features,
3455 					   __be16 type)
3456 {
3457 	if (eth_p_mpls(type))
3458 		features &= skb->dev->mpls_features;
3459 
3460 	return features;
3461 }
3462 #else
3463 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3464 					   netdev_features_t features,
3465 					   __be16 type)
3466 {
3467 	return features;
3468 }
3469 #endif
3470 
3471 static netdev_features_t harmonize_features(struct sk_buff *skb,
3472 	netdev_features_t features)
3473 {
3474 	__be16 type;
3475 
3476 	type = skb_network_protocol(skb, NULL);
3477 	features = net_mpls_features(skb, features, type);
3478 
3479 	if (skb->ip_summed != CHECKSUM_NONE &&
3480 	    !can_checksum_protocol(features, type)) {
3481 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3482 	}
3483 	if (illegal_highdma(skb->dev, skb))
3484 		features &= ~NETIF_F_SG;
3485 
3486 	return features;
3487 }
3488 
3489 netdev_features_t passthru_features_check(struct sk_buff *skb,
3490 					  struct net_device *dev,
3491 					  netdev_features_t features)
3492 {
3493 	return features;
3494 }
3495 EXPORT_SYMBOL(passthru_features_check);
3496 
3497 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3498 					     struct net_device *dev,
3499 					     netdev_features_t features)
3500 {
3501 	return vlan_features_check(skb, features);
3502 }
3503 
3504 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3505 					    struct net_device *dev,
3506 					    netdev_features_t features)
3507 {
3508 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3509 
3510 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3511 		return features & ~NETIF_F_GSO_MASK;
3512 
3513 	if (!skb_shinfo(skb)->gso_type) {
3514 		skb_warn_bad_offload(skb);
3515 		return features & ~NETIF_F_GSO_MASK;
3516 	}
3517 
3518 	/* Support for GSO partial features requires software
3519 	 * intervention before we can actually process the packets
3520 	 * so we need to strip support for any partial features now
3521 	 * and we can pull them back in after we have partially
3522 	 * segmented the frame.
3523 	 */
3524 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3525 		features &= ~dev->gso_partial_features;
3526 
3527 	/* Make sure to clear the IPv4 ID mangling feature if the
3528 	 * IPv4 header has the potential to be fragmented.
3529 	 */
3530 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3531 		struct iphdr *iph = skb->encapsulation ?
3532 				    inner_ip_hdr(skb) : ip_hdr(skb);
3533 
3534 		if (!(iph->frag_off & htons(IP_DF)))
3535 			features &= ~NETIF_F_TSO_MANGLEID;
3536 	}
3537 
3538 	return features;
3539 }
3540 
3541 netdev_features_t netif_skb_features(struct sk_buff *skb)
3542 {
3543 	struct net_device *dev = skb->dev;
3544 	netdev_features_t features = dev->features;
3545 
3546 	if (skb_is_gso(skb))
3547 		features = gso_features_check(skb, dev, features);
3548 
3549 	/* If encapsulation offload request, verify we are testing
3550 	 * hardware encapsulation features instead of standard
3551 	 * features for the netdev
3552 	 */
3553 	if (skb->encapsulation)
3554 		features &= dev->hw_enc_features;
3555 
3556 	if (skb_vlan_tagged(skb))
3557 		features = netdev_intersect_features(features,
3558 						     dev->vlan_features |
3559 						     NETIF_F_HW_VLAN_CTAG_TX |
3560 						     NETIF_F_HW_VLAN_STAG_TX);
3561 
3562 	if (dev->netdev_ops->ndo_features_check)
3563 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3564 								features);
3565 	else
3566 		features &= dflt_features_check(skb, dev, features);
3567 
3568 	return harmonize_features(skb, features);
3569 }
3570 EXPORT_SYMBOL(netif_skb_features);
3571 
3572 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3573 		    struct netdev_queue *txq, bool more)
3574 {
3575 	unsigned int len;
3576 	int rc;
3577 
3578 	if (dev_nit_active(dev))
3579 		dev_queue_xmit_nit(skb, dev);
3580 
3581 	len = skb->len;
3582 	trace_net_dev_start_xmit(skb, dev);
3583 	rc = netdev_start_xmit(skb, dev, txq, more);
3584 	trace_net_dev_xmit(skb, rc, dev, len);
3585 
3586 	return rc;
3587 }
3588 
3589 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3590 				    struct netdev_queue *txq, int *ret)
3591 {
3592 	struct sk_buff *skb = first;
3593 	int rc = NETDEV_TX_OK;
3594 
3595 	while (skb) {
3596 		struct sk_buff *next = skb->next;
3597 
3598 		skb_mark_not_on_list(skb);
3599 		rc = xmit_one(skb, dev, txq, next != NULL);
3600 		if (unlikely(!dev_xmit_complete(rc))) {
3601 			skb->next = next;
3602 			goto out;
3603 		}
3604 
3605 		skb = next;
3606 		if (netif_tx_queue_stopped(txq) && skb) {
3607 			rc = NETDEV_TX_BUSY;
3608 			break;
3609 		}
3610 	}
3611 
3612 out:
3613 	*ret = rc;
3614 	return skb;
3615 }
3616 
3617 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3618 					  netdev_features_t features)
3619 {
3620 	if (skb_vlan_tag_present(skb) &&
3621 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3622 		skb = __vlan_hwaccel_push_inside(skb);
3623 	return skb;
3624 }
3625 
3626 int skb_csum_hwoffload_help(struct sk_buff *skb,
3627 			    const netdev_features_t features)
3628 {
3629 	if (unlikely(skb_csum_is_sctp(skb)))
3630 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3631 			skb_crc32c_csum_help(skb);
3632 
3633 	if (features & NETIF_F_HW_CSUM)
3634 		return 0;
3635 
3636 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3637 		switch (skb->csum_offset) {
3638 		case offsetof(struct tcphdr, check):
3639 		case offsetof(struct udphdr, check):
3640 			return 0;
3641 		}
3642 	}
3643 
3644 	return skb_checksum_help(skb);
3645 }
3646 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3647 
3648 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3649 {
3650 	netdev_features_t features;
3651 
3652 	features = netif_skb_features(skb);
3653 	skb = validate_xmit_vlan(skb, features);
3654 	if (unlikely(!skb))
3655 		goto out_null;
3656 
3657 	skb = sk_validate_xmit_skb(skb, dev);
3658 	if (unlikely(!skb))
3659 		goto out_null;
3660 
3661 	if (netif_needs_gso(skb, features)) {
3662 		struct sk_buff *segs;
3663 
3664 		segs = skb_gso_segment(skb, features);
3665 		if (IS_ERR(segs)) {
3666 			goto out_kfree_skb;
3667 		} else if (segs) {
3668 			consume_skb(skb);
3669 			skb = segs;
3670 		}
3671 	} else {
3672 		if (skb_needs_linearize(skb, features) &&
3673 		    __skb_linearize(skb))
3674 			goto out_kfree_skb;
3675 
3676 		/* If packet is not checksummed and device does not
3677 		 * support checksumming for this protocol, complete
3678 		 * checksumming here.
3679 		 */
3680 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3681 			if (skb->encapsulation)
3682 				skb_set_inner_transport_header(skb,
3683 							       skb_checksum_start_offset(skb));
3684 			else
3685 				skb_set_transport_header(skb,
3686 							 skb_checksum_start_offset(skb));
3687 			if (skb_csum_hwoffload_help(skb, features))
3688 				goto out_kfree_skb;
3689 		}
3690 	}
3691 
3692 	skb = validate_xmit_xfrm(skb, features, again);
3693 
3694 	return skb;
3695 
3696 out_kfree_skb:
3697 	kfree_skb(skb);
3698 out_null:
3699 	dev_core_stats_tx_dropped_inc(dev);
3700 	return NULL;
3701 }
3702 
3703 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3704 {
3705 	struct sk_buff *next, *head = NULL, *tail;
3706 
3707 	for (; skb != NULL; skb = next) {
3708 		next = skb->next;
3709 		skb_mark_not_on_list(skb);
3710 
3711 		/* in case skb wont be segmented, point to itself */
3712 		skb->prev = skb;
3713 
3714 		skb = validate_xmit_skb(skb, dev, again);
3715 		if (!skb)
3716 			continue;
3717 
3718 		if (!head)
3719 			head = skb;
3720 		else
3721 			tail->next = skb;
3722 		/* If skb was segmented, skb->prev points to
3723 		 * the last segment. If not, it still contains skb.
3724 		 */
3725 		tail = skb->prev;
3726 	}
3727 	return head;
3728 }
3729 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3730 
3731 static void qdisc_pkt_len_init(struct sk_buff *skb)
3732 {
3733 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3734 
3735 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3736 
3737 	/* To get more precise estimation of bytes sent on wire,
3738 	 * we add to pkt_len the headers size of all segments
3739 	 */
3740 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3741 		unsigned int hdr_len;
3742 		u16 gso_segs = shinfo->gso_segs;
3743 
3744 		/* mac layer + network layer */
3745 		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3746 
3747 		/* + transport layer */
3748 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3749 			const struct tcphdr *th;
3750 			struct tcphdr _tcphdr;
3751 
3752 			th = skb_header_pointer(skb, skb_transport_offset(skb),
3753 						sizeof(_tcphdr), &_tcphdr);
3754 			if (likely(th))
3755 				hdr_len += __tcp_hdrlen(th);
3756 		} else {
3757 			struct udphdr _udphdr;
3758 
3759 			if (skb_header_pointer(skb, skb_transport_offset(skb),
3760 					       sizeof(_udphdr), &_udphdr))
3761 				hdr_len += sizeof(struct udphdr);
3762 		}
3763 
3764 		if (shinfo->gso_type & SKB_GSO_DODGY)
3765 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3766 						shinfo->gso_size);
3767 
3768 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3769 	}
3770 }
3771 
3772 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3773 			     struct sk_buff **to_free,
3774 			     struct netdev_queue *txq)
3775 {
3776 	int rc;
3777 
3778 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3779 	if (rc == NET_XMIT_SUCCESS)
3780 		trace_qdisc_enqueue(q, txq, skb);
3781 	return rc;
3782 }
3783 
3784 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3785 				 struct net_device *dev,
3786 				 struct netdev_queue *txq)
3787 {
3788 	spinlock_t *root_lock = qdisc_lock(q);
3789 	struct sk_buff *to_free = NULL;
3790 	bool contended;
3791 	int rc;
3792 
3793 	qdisc_calculate_pkt_len(skb, q);
3794 
3795 	if (q->flags & TCQ_F_NOLOCK) {
3796 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3797 		    qdisc_run_begin(q)) {
3798 			/* Retest nolock_qdisc_is_empty() within the protection
3799 			 * of q->seqlock to protect from racing with requeuing.
3800 			 */
3801 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3802 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3803 				__qdisc_run(q);
3804 				qdisc_run_end(q);
3805 
3806 				goto no_lock_out;
3807 			}
3808 
3809 			qdisc_bstats_cpu_update(q, skb);
3810 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3811 			    !nolock_qdisc_is_empty(q))
3812 				__qdisc_run(q);
3813 
3814 			qdisc_run_end(q);
3815 			return NET_XMIT_SUCCESS;
3816 		}
3817 
3818 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3819 		qdisc_run(q);
3820 
3821 no_lock_out:
3822 		if (unlikely(to_free))
3823 			kfree_skb_list_reason(to_free,
3824 					      SKB_DROP_REASON_QDISC_DROP);
3825 		return rc;
3826 	}
3827 
3828 	/*
3829 	 * Heuristic to force contended enqueues to serialize on a
3830 	 * separate lock before trying to get qdisc main lock.
3831 	 * This permits qdisc->running owner to get the lock more
3832 	 * often and dequeue packets faster.
3833 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3834 	 * and then other tasks will only enqueue packets. The packets will be
3835 	 * sent after the qdisc owner is scheduled again. To prevent this
3836 	 * scenario the task always serialize on the lock.
3837 	 */
3838 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3839 	if (unlikely(contended))
3840 		spin_lock(&q->busylock);
3841 
3842 	spin_lock(root_lock);
3843 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3844 		__qdisc_drop(skb, &to_free);
3845 		rc = NET_XMIT_DROP;
3846 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3847 		   qdisc_run_begin(q)) {
3848 		/*
3849 		 * This is a work-conserving queue; there are no old skbs
3850 		 * waiting to be sent out; and the qdisc is not running -
3851 		 * xmit the skb directly.
3852 		 */
3853 
3854 		qdisc_bstats_update(q, skb);
3855 
3856 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3857 			if (unlikely(contended)) {
3858 				spin_unlock(&q->busylock);
3859 				contended = false;
3860 			}
3861 			__qdisc_run(q);
3862 		}
3863 
3864 		qdisc_run_end(q);
3865 		rc = NET_XMIT_SUCCESS;
3866 	} else {
3867 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3868 		if (qdisc_run_begin(q)) {
3869 			if (unlikely(contended)) {
3870 				spin_unlock(&q->busylock);
3871 				contended = false;
3872 			}
3873 			__qdisc_run(q);
3874 			qdisc_run_end(q);
3875 		}
3876 	}
3877 	spin_unlock(root_lock);
3878 	if (unlikely(to_free))
3879 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3880 	if (unlikely(contended))
3881 		spin_unlock(&q->busylock);
3882 	return rc;
3883 }
3884 
3885 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3886 static void skb_update_prio(struct sk_buff *skb)
3887 {
3888 	const struct netprio_map *map;
3889 	const struct sock *sk;
3890 	unsigned int prioidx;
3891 
3892 	if (skb->priority)
3893 		return;
3894 	map = rcu_dereference_bh(skb->dev->priomap);
3895 	if (!map)
3896 		return;
3897 	sk = skb_to_full_sk(skb);
3898 	if (!sk)
3899 		return;
3900 
3901 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3902 
3903 	if (prioidx < map->priomap_len)
3904 		skb->priority = map->priomap[prioidx];
3905 }
3906 #else
3907 #define skb_update_prio(skb)
3908 #endif
3909 
3910 /**
3911  *	dev_loopback_xmit - loop back @skb
3912  *	@net: network namespace this loopback is happening in
3913  *	@sk:  sk needed to be a netfilter okfn
3914  *	@skb: buffer to transmit
3915  */
3916 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3917 {
3918 	skb_reset_mac_header(skb);
3919 	__skb_pull(skb, skb_network_offset(skb));
3920 	skb->pkt_type = PACKET_LOOPBACK;
3921 	if (skb->ip_summed == CHECKSUM_NONE)
3922 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3923 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3924 	skb_dst_force(skb);
3925 	netif_rx(skb);
3926 	return 0;
3927 }
3928 EXPORT_SYMBOL(dev_loopback_xmit);
3929 
3930 #ifdef CONFIG_NET_EGRESS
3931 static struct sk_buff *
3932 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3933 {
3934 #ifdef CONFIG_NET_CLS_ACT
3935 	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3936 	struct tcf_result cl_res;
3937 
3938 	if (!miniq)
3939 		return skb;
3940 
3941 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3942 	tc_skb_cb(skb)->mru = 0;
3943 	tc_skb_cb(skb)->post_ct = false;
3944 	mini_qdisc_bstats_cpu_update(miniq, skb);
3945 
3946 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3947 	case TC_ACT_OK:
3948 	case TC_ACT_RECLASSIFY:
3949 		skb->tc_index = TC_H_MIN(cl_res.classid);
3950 		break;
3951 	case TC_ACT_SHOT:
3952 		mini_qdisc_qstats_cpu_drop(miniq);
3953 		*ret = NET_XMIT_DROP;
3954 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3955 		return NULL;
3956 	case TC_ACT_STOLEN:
3957 	case TC_ACT_QUEUED:
3958 	case TC_ACT_TRAP:
3959 		*ret = NET_XMIT_SUCCESS;
3960 		consume_skb(skb);
3961 		return NULL;
3962 	case TC_ACT_REDIRECT:
3963 		/* No need to push/pop skb's mac_header here on egress! */
3964 		skb_do_redirect(skb);
3965 		*ret = NET_XMIT_SUCCESS;
3966 		return NULL;
3967 	default:
3968 		break;
3969 	}
3970 #endif /* CONFIG_NET_CLS_ACT */
3971 
3972 	return skb;
3973 }
3974 
3975 static struct netdev_queue *
3976 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3977 {
3978 	int qm = skb_get_queue_mapping(skb);
3979 
3980 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3981 }
3982 
3983 static bool netdev_xmit_txqueue_skipped(void)
3984 {
3985 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3986 }
3987 
3988 void netdev_xmit_skip_txqueue(bool skip)
3989 {
3990 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3991 }
3992 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3993 #endif /* CONFIG_NET_EGRESS */
3994 
3995 #ifdef CONFIG_XPS
3996 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3997 			       struct xps_dev_maps *dev_maps, unsigned int tci)
3998 {
3999 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
4000 	struct xps_map *map;
4001 	int queue_index = -1;
4002 
4003 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4004 		return queue_index;
4005 
4006 	tci *= dev_maps->num_tc;
4007 	tci += tc;
4008 
4009 	map = rcu_dereference(dev_maps->attr_map[tci]);
4010 	if (map) {
4011 		if (map->len == 1)
4012 			queue_index = map->queues[0];
4013 		else
4014 			queue_index = map->queues[reciprocal_scale(
4015 						skb_get_hash(skb), map->len)];
4016 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4017 			queue_index = -1;
4018 	}
4019 	return queue_index;
4020 }
4021 #endif
4022 
4023 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4024 			 struct sk_buff *skb)
4025 {
4026 #ifdef CONFIG_XPS
4027 	struct xps_dev_maps *dev_maps;
4028 	struct sock *sk = skb->sk;
4029 	int queue_index = -1;
4030 
4031 	if (!static_key_false(&xps_needed))
4032 		return -1;
4033 
4034 	rcu_read_lock();
4035 	if (!static_key_false(&xps_rxqs_needed))
4036 		goto get_cpus_map;
4037 
4038 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4039 	if (dev_maps) {
4040 		int tci = sk_rx_queue_get(sk);
4041 
4042 		if (tci >= 0)
4043 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4044 							  tci);
4045 	}
4046 
4047 get_cpus_map:
4048 	if (queue_index < 0) {
4049 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4050 		if (dev_maps) {
4051 			unsigned int tci = skb->sender_cpu - 1;
4052 
4053 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4054 							  tci);
4055 		}
4056 	}
4057 	rcu_read_unlock();
4058 
4059 	return queue_index;
4060 #else
4061 	return -1;
4062 #endif
4063 }
4064 
4065 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4066 		     struct net_device *sb_dev)
4067 {
4068 	return 0;
4069 }
4070 EXPORT_SYMBOL(dev_pick_tx_zero);
4071 
4072 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4073 		       struct net_device *sb_dev)
4074 {
4075 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4076 }
4077 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4078 
4079 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4080 		     struct net_device *sb_dev)
4081 {
4082 	struct sock *sk = skb->sk;
4083 	int queue_index = sk_tx_queue_get(sk);
4084 
4085 	sb_dev = sb_dev ? : dev;
4086 
4087 	if (queue_index < 0 || skb->ooo_okay ||
4088 	    queue_index >= dev->real_num_tx_queues) {
4089 		int new_index = get_xps_queue(dev, sb_dev, skb);
4090 
4091 		if (new_index < 0)
4092 			new_index = skb_tx_hash(dev, sb_dev, skb);
4093 
4094 		if (queue_index != new_index && sk &&
4095 		    sk_fullsock(sk) &&
4096 		    rcu_access_pointer(sk->sk_dst_cache))
4097 			sk_tx_queue_set(sk, new_index);
4098 
4099 		queue_index = new_index;
4100 	}
4101 
4102 	return queue_index;
4103 }
4104 EXPORT_SYMBOL(netdev_pick_tx);
4105 
4106 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4107 					 struct sk_buff *skb,
4108 					 struct net_device *sb_dev)
4109 {
4110 	int queue_index = 0;
4111 
4112 #ifdef CONFIG_XPS
4113 	u32 sender_cpu = skb->sender_cpu - 1;
4114 
4115 	if (sender_cpu >= (u32)NR_CPUS)
4116 		skb->sender_cpu = raw_smp_processor_id() + 1;
4117 #endif
4118 
4119 	if (dev->real_num_tx_queues != 1) {
4120 		const struct net_device_ops *ops = dev->netdev_ops;
4121 
4122 		if (ops->ndo_select_queue)
4123 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4124 		else
4125 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4126 
4127 		queue_index = netdev_cap_txqueue(dev, queue_index);
4128 	}
4129 
4130 	skb_set_queue_mapping(skb, queue_index);
4131 	return netdev_get_tx_queue(dev, queue_index);
4132 }
4133 
4134 /**
4135  * __dev_queue_xmit() - transmit a buffer
4136  * @skb:	buffer to transmit
4137  * @sb_dev:	suboordinate device used for L2 forwarding offload
4138  *
4139  * Queue a buffer for transmission to a network device. The caller must
4140  * have set the device and priority and built the buffer before calling
4141  * this function. The function can be called from an interrupt.
4142  *
4143  * When calling this method, interrupts MUST be enabled. This is because
4144  * the BH enable code must have IRQs enabled so that it will not deadlock.
4145  *
4146  * Regardless of the return value, the skb is consumed, so it is currently
4147  * difficult to retry a send to this method. (You can bump the ref count
4148  * before sending to hold a reference for retry if you are careful.)
4149  *
4150  * Return:
4151  * * 0				- buffer successfully transmitted
4152  * * positive qdisc return code	- NET_XMIT_DROP etc.
4153  * * negative errno		- other errors
4154  */
4155 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4156 {
4157 	struct net_device *dev = skb->dev;
4158 	struct netdev_queue *txq = NULL;
4159 	struct Qdisc *q;
4160 	int rc = -ENOMEM;
4161 	bool again = false;
4162 
4163 	skb_reset_mac_header(skb);
4164 	skb_assert_len(skb);
4165 
4166 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4167 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4168 
4169 	/* Disable soft irqs for various locks below. Also
4170 	 * stops preemption for RCU.
4171 	 */
4172 	rcu_read_lock_bh();
4173 
4174 	skb_update_prio(skb);
4175 
4176 	qdisc_pkt_len_init(skb);
4177 #ifdef CONFIG_NET_CLS_ACT
4178 	skb->tc_at_ingress = 0;
4179 #endif
4180 #ifdef CONFIG_NET_EGRESS
4181 	if (static_branch_unlikely(&egress_needed_key)) {
4182 		if (nf_hook_egress_active()) {
4183 			skb = nf_hook_egress(skb, &rc, dev);
4184 			if (!skb)
4185 				goto out;
4186 		}
4187 
4188 		netdev_xmit_skip_txqueue(false);
4189 
4190 		nf_skip_egress(skb, true);
4191 		skb = sch_handle_egress(skb, &rc, dev);
4192 		if (!skb)
4193 			goto out;
4194 		nf_skip_egress(skb, false);
4195 
4196 		if (netdev_xmit_txqueue_skipped())
4197 			txq = netdev_tx_queue_mapping(dev, skb);
4198 	}
4199 #endif
4200 	/* If device/qdisc don't need skb->dst, release it right now while
4201 	 * its hot in this cpu cache.
4202 	 */
4203 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4204 		skb_dst_drop(skb);
4205 	else
4206 		skb_dst_force(skb);
4207 
4208 	if (!txq)
4209 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4210 
4211 	q = rcu_dereference_bh(txq->qdisc);
4212 
4213 	trace_net_dev_queue(skb);
4214 	if (q->enqueue) {
4215 		rc = __dev_xmit_skb(skb, q, dev, txq);
4216 		goto out;
4217 	}
4218 
4219 	/* The device has no queue. Common case for software devices:
4220 	 * loopback, all the sorts of tunnels...
4221 
4222 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4223 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4224 	 * counters.)
4225 	 * However, it is possible, that they rely on protection
4226 	 * made by us here.
4227 
4228 	 * Check this and shot the lock. It is not prone from deadlocks.
4229 	 *Either shot noqueue qdisc, it is even simpler 8)
4230 	 */
4231 	if (dev->flags & IFF_UP) {
4232 		int cpu = smp_processor_id(); /* ok because BHs are off */
4233 
4234 		/* Other cpus might concurrently change txq->xmit_lock_owner
4235 		 * to -1 or to their cpu id, but not to our id.
4236 		 */
4237 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4238 			if (dev_xmit_recursion())
4239 				goto recursion_alert;
4240 
4241 			skb = validate_xmit_skb(skb, dev, &again);
4242 			if (!skb)
4243 				goto out;
4244 
4245 			HARD_TX_LOCK(dev, txq, cpu);
4246 
4247 			if (!netif_xmit_stopped(txq)) {
4248 				dev_xmit_recursion_inc();
4249 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4250 				dev_xmit_recursion_dec();
4251 				if (dev_xmit_complete(rc)) {
4252 					HARD_TX_UNLOCK(dev, txq);
4253 					goto out;
4254 				}
4255 			}
4256 			HARD_TX_UNLOCK(dev, txq);
4257 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4258 					     dev->name);
4259 		} else {
4260 			/* Recursion is detected! It is possible,
4261 			 * unfortunately
4262 			 */
4263 recursion_alert:
4264 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4265 					     dev->name);
4266 		}
4267 	}
4268 
4269 	rc = -ENETDOWN;
4270 	rcu_read_unlock_bh();
4271 
4272 	dev_core_stats_tx_dropped_inc(dev);
4273 	kfree_skb_list(skb);
4274 	return rc;
4275 out:
4276 	rcu_read_unlock_bh();
4277 	return rc;
4278 }
4279 EXPORT_SYMBOL(__dev_queue_xmit);
4280 
4281 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4282 {
4283 	struct net_device *dev = skb->dev;
4284 	struct sk_buff *orig_skb = skb;
4285 	struct netdev_queue *txq;
4286 	int ret = NETDEV_TX_BUSY;
4287 	bool again = false;
4288 
4289 	if (unlikely(!netif_running(dev) ||
4290 		     !netif_carrier_ok(dev)))
4291 		goto drop;
4292 
4293 	skb = validate_xmit_skb_list(skb, dev, &again);
4294 	if (skb != orig_skb)
4295 		goto drop;
4296 
4297 	skb_set_queue_mapping(skb, queue_id);
4298 	txq = skb_get_tx_queue(dev, skb);
4299 
4300 	local_bh_disable();
4301 
4302 	dev_xmit_recursion_inc();
4303 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4304 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4305 		ret = netdev_start_xmit(skb, dev, txq, false);
4306 	HARD_TX_UNLOCK(dev, txq);
4307 	dev_xmit_recursion_dec();
4308 
4309 	local_bh_enable();
4310 	return ret;
4311 drop:
4312 	dev_core_stats_tx_dropped_inc(dev);
4313 	kfree_skb_list(skb);
4314 	return NET_XMIT_DROP;
4315 }
4316 EXPORT_SYMBOL(__dev_direct_xmit);
4317 
4318 /*************************************************************************
4319  *			Receiver routines
4320  *************************************************************************/
4321 
4322 int netdev_max_backlog __read_mostly = 1000;
4323 EXPORT_SYMBOL(netdev_max_backlog);
4324 
4325 int netdev_tstamp_prequeue __read_mostly = 1;
4326 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4327 int netdev_budget __read_mostly = 300;
4328 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4329 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4330 int weight_p __read_mostly = 64;           /* old backlog weight */
4331 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4332 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4333 int dev_rx_weight __read_mostly = 64;
4334 int dev_tx_weight __read_mostly = 64;
4335 
4336 /* Called with irq disabled */
4337 static inline void ____napi_schedule(struct softnet_data *sd,
4338 				     struct napi_struct *napi)
4339 {
4340 	struct task_struct *thread;
4341 
4342 	lockdep_assert_irqs_disabled();
4343 
4344 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4345 		/* Paired with smp_mb__before_atomic() in
4346 		 * napi_enable()/dev_set_threaded().
4347 		 * Use READ_ONCE() to guarantee a complete
4348 		 * read on napi->thread. Only call
4349 		 * wake_up_process() when it's not NULL.
4350 		 */
4351 		thread = READ_ONCE(napi->thread);
4352 		if (thread) {
4353 			/* Avoid doing set_bit() if the thread is in
4354 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4355 			 * makes sure to proceed with napi polling
4356 			 * if the thread is explicitly woken from here.
4357 			 */
4358 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4359 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4360 			wake_up_process(thread);
4361 			return;
4362 		}
4363 	}
4364 
4365 	list_add_tail(&napi->poll_list, &sd->poll_list);
4366 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4367 }
4368 
4369 #ifdef CONFIG_RPS
4370 
4371 /* One global table that all flow-based protocols share. */
4372 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4373 EXPORT_SYMBOL(rps_sock_flow_table);
4374 u32 rps_cpu_mask __read_mostly;
4375 EXPORT_SYMBOL(rps_cpu_mask);
4376 
4377 struct static_key_false rps_needed __read_mostly;
4378 EXPORT_SYMBOL(rps_needed);
4379 struct static_key_false rfs_needed __read_mostly;
4380 EXPORT_SYMBOL(rfs_needed);
4381 
4382 static struct rps_dev_flow *
4383 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4384 	    struct rps_dev_flow *rflow, u16 next_cpu)
4385 {
4386 	if (next_cpu < nr_cpu_ids) {
4387 #ifdef CONFIG_RFS_ACCEL
4388 		struct netdev_rx_queue *rxqueue;
4389 		struct rps_dev_flow_table *flow_table;
4390 		struct rps_dev_flow *old_rflow;
4391 		u32 flow_id;
4392 		u16 rxq_index;
4393 		int rc;
4394 
4395 		/* Should we steer this flow to a different hardware queue? */
4396 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4397 		    !(dev->features & NETIF_F_NTUPLE))
4398 			goto out;
4399 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4400 		if (rxq_index == skb_get_rx_queue(skb))
4401 			goto out;
4402 
4403 		rxqueue = dev->_rx + rxq_index;
4404 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4405 		if (!flow_table)
4406 			goto out;
4407 		flow_id = skb_get_hash(skb) & flow_table->mask;
4408 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4409 							rxq_index, flow_id);
4410 		if (rc < 0)
4411 			goto out;
4412 		old_rflow = rflow;
4413 		rflow = &flow_table->flows[flow_id];
4414 		rflow->filter = rc;
4415 		if (old_rflow->filter == rflow->filter)
4416 			old_rflow->filter = RPS_NO_FILTER;
4417 	out:
4418 #endif
4419 		rflow->last_qtail =
4420 			per_cpu(softnet_data, next_cpu).input_queue_head;
4421 	}
4422 
4423 	rflow->cpu = next_cpu;
4424 	return rflow;
4425 }
4426 
4427 /*
4428  * get_rps_cpu is called from netif_receive_skb and returns the target
4429  * CPU from the RPS map of the receiving queue for a given skb.
4430  * rcu_read_lock must be held on entry.
4431  */
4432 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4433 		       struct rps_dev_flow **rflowp)
4434 {
4435 	const struct rps_sock_flow_table *sock_flow_table;
4436 	struct netdev_rx_queue *rxqueue = dev->_rx;
4437 	struct rps_dev_flow_table *flow_table;
4438 	struct rps_map *map;
4439 	int cpu = -1;
4440 	u32 tcpu;
4441 	u32 hash;
4442 
4443 	if (skb_rx_queue_recorded(skb)) {
4444 		u16 index = skb_get_rx_queue(skb);
4445 
4446 		if (unlikely(index >= dev->real_num_rx_queues)) {
4447 			WARN_ONCE(dev->real_num_rx_queues > 1,
4448 				  "%s received packet on queue %u, but number "
4449 				  "of RX queues is %u\n",
4450 				  dev->name, index, dev->real_num_rx_queues);
4451 			goto done;
4452 		}
4453 		rxqueue += index;
4454 	}
4455 
4456 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4457 
4458 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4459 	map = rcu_dereference(rxqueue->rps_map);
4460 	if (!flow_table && !map)
4461 		goto done;
4462 
4463 	skb_reset_network_header(skb);
4464 	hash = skb_get_hash(skb);
4465 	if (!hash)
4466 		goto done;
4467 
4468 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4469 	if (flow_table && sock_flow_table) {
4470 		struct rps_dev_flow *rflow;
4471 		u32 next_cpu;
4472 		u32 ident;
4473 
4474 		/* First check into global flow table if there is a match */
4475 		ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4476 		if ((ident ^ hash) & ~rps_cpu_mask)
4477 			goto try_rps;
4478 
4479 		next_cpu = ident & rps_cpu_mask;
4480 
4481 		/* OK, now we know there is a match,
4482 		 * we can look at the local (per receive queue) flow table
4483 		 */
4484 		rflow = &flow_table->flows[hash & flow_table->mask];
4485 		tcpu = rflow->cpu;
4486 
4487 		/*
4488 		 * If the desired CPU (where last recvmsg was done) is
4489 		 * different from current CPU (one in the rx-queue flow
4490 		 * table entry), switch if one of the following holds:
4491 		 *   - Current CPU is unset (>= nr_cpu_ids).
4492 		 *   - Current CPU is offline.
4493 		 *   - The current CPU's queue tail has advanced beyond the
4494 		 *     last packet that was enqueued using this table entry.
4495 		 *     This guarantees that all previous packets for the flow
4496 		 *     have been dequeued, thus preserving in order delivery.
4497 		 */
4498 		if (unlikely(tcpu != next_cpu) &&
4499 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4500 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4501 		      rflow->last_qtail)) >= 0)) {
4502 			tcpu = next_cpu;
4503 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4504 		}
4505 
4506 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4507 			*rflowp = rflow;
4508 			cpu = tcpu;
4509 			goto done;
4510 		}
4511 	}
4512 
4513 try_rps:
4514 
4515 	if (map) {
4516 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4517 		if (cpu_online(tcpu)) {
4518 			cpu = tcpu;
4519 			goto done;
4520 		}
4521 	}
4522 
4523 done:
4524 	return cpu;
4525 }
4526 
4527 #ifdef CONFIG_RFS_ACCEL
4528 
4529 /**
4530  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4531  * @dev: Device on which the filter was set
4532  * @rxq_index: RX queue index
4533  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4534  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4535  *
4536  * Drivers that implement ndo_rx_flow_steer() should periodically call
4537  * this function for each installed filter and remove the filters for
4538  * which it returns %true.
4539  */
4540 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4541 			 u32 flow_id, u16 filter_id)
4542 {
4543 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4544 	struct rps_dev_flow_table *flow_table;
4545 	struct rps_dev_flow *rflow;
4546 	bool expire = true;
4547 	unsigned int cpu;
4548 
4549 	rcu_read_lock();
4550 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4551 	if (flow_table && flow_id <= flow_table->mask) {
4552 		rflow = &flow_table->flows[flow_id];
4553 		cpu = READ_ONCE(rflow->cpu);
4554 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4555 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4556 			   rflow->last_qtail) <
4557 		     (int)(10 * flow_table->mask)))
4558 			expire = false;
4559 	}
4560 	rcu_read_unlock();
4561 	return expire;
4562 }
4563 EXPORT_SYMBOL(rps_may_expire_flow);
4564 
4565 #endif /* CONFIG_RFS_ACCEL */
4566 
4567 /* Called from hardirq (IPI) context */
4568 static void rps_trigger_softirq(void *data)
4569 {
4570 	struct softnet_data *sd = data;
4571 
4572 	____napi_schedule(sd, &sd->backlog);
4573 	sd->received_rps++;
4574 }
4575 
4576 #endif /* CONFIG_RPS */
4577 
4578 /* Called from hardirq (IPI) context */
4579 static void trigger_rx_softirq(void *data)
4580 {
4581 	struct softnet_data *sd = data;
4582 
4583 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4584 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4585 }
4586 
4587 /*
4588  * Check if this softnet_data structure is another cpu one
4589  * If yes, queue it to our IPI list and return 1
4590  * If no, return 0
4591  */
4592 static int napi_schedule_rps(struct softnet_data *sd)
4593 {
4594 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4595 
4596 #ifdef CONFIG_RPS
4597 	if (sd != mysd) {
4598 		sd->rps_ipi_next = mysd->rps_ipi_list;
4599 		mysd->rps_ipi_list = sd;
4600 
4601 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4602 		return 1;
4603 	}
4604 #endif /* CONFIG_RPS */
4605 	__napi_schedule_irqoff(&mysd->backlog);
4606 	return 0;
4607 }
4608 
4609 #ifdef CONFIG_NET_FLOW_LIMIT
4610 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4611 #endif
4612 
4613 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4614 {
4615 #ifdef CONFIG_NET_FLOW_LIMIT
4616 	struct sd_flow_limit *fl;
4617 	struct softnet_data *sd;
4618 	unsigned int old_flow, new_flow;
4619 
4620 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4621 		return false;
4622 
4623 	sd = this_cpu_ptr(&softnet_data);
4624 
4625 	rcu_read_lock();
4626 	fl = rcu_dereference(sd->flow_limit);
4627 	if (fl) {
4628 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4629 		old_flow = fl->history[fl->history_head];
4630 		fl->history[fl->history_head] = new_flow;
4631 
4632 		fl->history_head++;
4633 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4634 
4635 		if (likely(fl->buckets[old_flow]))
4636 			fl->buckets[old_flow]--;
4637 
4638 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4639 			fl->count++;
4640 			rcu_read_unlock();
4641 			return true;
4642 		}
4643 	}
4644 	rcu_read_unlock();
4645 #endif
4646 	return false;
4647 }
4648 
4649 /*
4650  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4651  * queue (may be a remote CPU queue).
4652  */
4653 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4654 			      unsigned int *qtail)
4655 {
4656 	enum skb_drop_reason reason;
4657 	struct softnet_data *sd;
4658 	unsigned long flags;
4659 	unsigned int qlen;
4660 
4661 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4662 	sd = &per_cpu(softnet_data, cpu);
4663 
4664 	rps_lock_irqsave(sd, &flags);
4665 	if (!netif_running(skb->dev))
4666 		goto drop;
4667 	qlen = skb_queue_len(&sd->input_pkt_queue);
4668 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4669 		if (qlen) {
4670 enqueue:
4671 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4672 			input_queue_tail_incr_save(sd, qtail);
4673 			rps_unlock_irq_restore(sd, &flags);
4674 			return NET_RX_SUCCESS;
4675 		}
4676 
4677 		/* Schedule NAPI for backlog device
4678 		 * We can use non atomic operation since we own the queue lock
4679 		 */
4680 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4681 			napi_schedule_rps(sd);
4682 		goto enqueue;
4683 	}
4684 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4685 
4686 drop:
4687 	sd->dropped++;
4688 	rps_unlock_irq_restore(sd, &flags);
4689 
4690 	dev_core_stats_rx_dropped_inc(skb->dev);
4691 	kfree_skb_reason(skb, reason);
4692 	return NET_RX_DROP;
4693 }
4694 
4695 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4696 {
4697 	struct net_device *dev = skb->dev;
4698 	struct netdev_rx_queue *rxqueue;
4699 
4700 	rxqueue = dev->_rx;
4701 
4702 	if (skb_rx_queue_recorded(skb)) {
4703 		u16 index = skb_get_rx_queue(skb);
4704 
4705 		if (unlikely(index >= dev->real_num_rx_queues)) {
4706 			WARN_ONCE(dev->real_num_rx_queues > 1,
4707 				  "%s received packet on queue %u, but number "
4708 				  "of RX queues is %u\n",
4709 				  dev->name, index, dev->real_num_rx_queues);
4710 
4711 			return rxqueue; /* Return first rxqueue */
4712 		}
4713 		rxqueue += index;
4714 	}
4715 	return rxqueue;
4716 }
4717 
4718 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4719 			     struct bpf_prog *xdp_prog)
4720 {
4721 	void *orig_data, *orig_data_end, *hard_start;
4722 	struct netdev_rx_queue *rxqueue;
4723 	bool orig_bcast, orig_host;
4724 	u32 mac_len, frame_sz;
4725 	__be16 orig_eth_type;
4726 	struct ethhdr *eth;
4727 	u32 metalen, act;
4728 	int off;
4729 
4730 	/* The XDP program wants to see the packet starting at the MAC
4731 	 * header.
4732 	 */
4733 	mac_len = skb->data - skb_mac_header(skb);
4734 	hard_start = skb->data - skb_headroom(skb);
4735 
4736 	/* SKB "head" area always have tailroom for skb_shared_info */
4737 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4738 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4739 
4740 	rxqueue = netif_get_rxqueue(skb);
4741 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4742 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4743 			 skb_headlen(skb) + mac_len, true);
4744 
4745 	orig_data_end = xdp->data_end;
4746 	orig_data = xdp->data;
4747 	eth = (struct ethhdr *)xdp->data;
4748 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4749 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4750 	orig_eth_type = eth->h_proto;
4751 
4752 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4753 
4754 	/* check if bpf_xdp_adjust_head was used */
4755 	off = xdp->data - orig_data;
4756 	if (off) {
4757 		if (off > 0)
4758 			__skb_pull(skb, off);
4759 		else if (off < 0)
4760 			__skb_push(skb, -off);
4761 
4762 		skb->mac_header += off;
4763 		skb_reset_network_header(skb);
4764 	}
4765 
4766 	/* check if bpf_xdp_adjust_tail was used */
4767 	off = xdp->data_end - orig_data_end;
4768 	if (off != 0) {
4769 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4770 		skb->len += off; /* positive on grow, negative on shrink */
4771 	}
4772 
4773 	/* check if XDP changed eth hdr such SKB needs update */
4774 	eth = (struct ethhdr *)xdp->data;
4775 	if ((orig_eth_type != eth->h_proto) ||
4776 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4777 						  skb->dev->dev_addr)) ||
4778 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4779 		__skb_push(skb, ETH_HLEN);
4780 		skb->pkt_type = PACKET_HOST;
4781 		skb->protocol = eth_type_trans(skb, skb->dev);
4782 	}
4783 
4784 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4785 	 * before calling us again on redirect path. We do not call do_redirect
4786 	 * as we leave that up to the caller.
4787 	 *
4788 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4789 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4790 	 */
4791 	switch (act) {
4792 	case XDP_REDIRECT:
4793 	case XDP_TX:
4794 		__skb_push(skb, mac_len);
4795 		break;
4796 	case XDP_PASS:
4797 		metalen = xdp->data - xdp->data_meta;
4798 		if (metalen)
4799 			skb_metadata_set(skb, metalen);
4800 		break;
4801 	}
4802 
4803 	return act;
4804 }
4805 
4806 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4807 				     struct xdp_buff *xdp,
4808 				     struct bpf_prog *xdp_prog)
4809 {
4810 	u32 act = XDP_DROP;
4811 
4812 	/* Reinjected packets coming from act_mirred or similar should
4813 	 * not get XDP generic processing.
4814 	 */
4815 	if (skb_is_redirected(skb))
4816 		return XDP_PASS;
4817 
4818 	/* XDP packets must be linear and must have sufficient headroom
4819 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4820 	 * native XDP provides, thus we need to do it here as well.
4821 	 */
4822 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4823 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4824 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4825 		int troom = skb->tail + skb->data_len - skb->end;
4826 
4827 		/* In case we have to go down the path and also linearize,
4828 		 * then lets do the pskb_expand_head() work just once here.
4829 		 */
4830 		if (pskb_expand_head(skb,
4831 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4832 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4833 			goto do_drop;
4834 		if (skb_linearize(skb))
4835 			goto do_drop;
4836 	}
4837 
4838 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4839 	switch (act) {
4840 	case XDP_REDIRECT:
4841 	case XDP_TX:
4842 	case XDP_PASS:
4843 		break;
4844 	default:
4845 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4846 		fallthrough;
4847 	case XDP_ABORTED:
4848 		trace_xdp_exception(skb->dev, xdp_prog, act);
4849 		fallthrough;
4850 	case XDP_DROP:
4851 	do_drop:
4852 		kfree_skb(skb);
4853 		break;
4854 	}
4855 
4856 	return act;
4857 }
4858 
4859 /* When doing generic XDP we have to bypass the qdisc layer and the
4860  * network taps in order to match in-driver-XDP behavior. This also means
4861  * that XDP packets are able to starve other packets going through a qdisc,
4862  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4863  * queues, so they do not have this starvation issue.
4864  */
4865 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4866 {
4867 	struct net_device *dev = skb->dev;
4868 	struct netdev_queue *txq;
4869 	bool free_skb = true;
4870 	int cpu, rc;
4871 
4872 	txq = netdev_core_pick_tx(dev, skb, NULL);
4873 	cpu = smp_processor_id();
4874 	HARD_TX_LOCK(dev, txq, cpu);
4875 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4876 		rc = netdev_start_xmit(skb, dev, txq, 0);
4877 		if (dev_xmit_complete(rc))
4878 			free_skb = false;
4879 	}
4880 	HARD_TX_UNLOCK(dev, txq);
4881 	if (free_skb) {
4882 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4883 		dev_core_stats_tx_dropped_inc(dev);
4884 		kfree_skb(skb);
4885 	}
4886 }
4887 
4888 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4889 
4890 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4891 {
4892 	if (xdp_prog) {
4893 		struct xdp_buff xdp;
4894 		u32 act;
4895 		int err;
4896 
4897 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4898 		if (act != XDP_PASS) {
4899 			switch (act) {
4900 			case XDP_REDIRECT:
4901 				err = xdp_do_generic_redirect(skb->dev, skb,
4902 							      &xdp, xdp_prog);
4903 				if (err)
4904 					goto out_redir;
4905 				break;
4906 			case XDP_TX:
4907 				generic_xdp_tx(skb, xdp_prog);
4908 				break;
4909 			}
4910 			return XDP_DROP;
4911 		}
4912 	}
4913 	return XDP_PASS;
4914 out_redir:
4915 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4916 	return XDP_DROP;
4917 }
4918 EXPORT_SYMBOL_GPL(do_xdp_generic);
4919 
4920 static int netif_rx_internal(struct sk_buff *skb)
4921 {
4922 	int ret;
4923 
4924 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
4925 
4926 	trace_netif_rx(skb);
4927 
4928 #ifdef CONFIG_RPS
4929 	if (static_branch_unlikely(&rps_needed)) {
4930 		struct rps_dev_flow voidflow, *rflow = &voidflow;
4931 		int cpu;
4932 
4933 		rcu_read_lock();
4934 
4935 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
4936 		if (cpu < 0)
4937 			cpu = smp_processor_id();
4938 
4939 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4940 
4941 		rcu_read_unlock();
4942 	} else
4943 #endif
4944 	{
4945 		unsigned int qtail;
4946 
4947 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4948 	}
4949 	return ret;
4950 }
4951 
4952 /**
4953  *	__netif_rx	-	Slightly optimized version of netif_rx
4954  *	@skb: buffer to post
4955  *
4956  *	This behaves as netif_rx except that it does not disable bottom halves.
4957  *	As a result this function may only be invoked from the interrupt context
4958  *	(either hard or soft interrupt).
4959  */
4960 int __netif_rx(struct sk_buff *skb)
4961 {
4962 	int ret;
4963 
4964 	lockdep_assert_once(hardirq_count() | softirq_count());
4965 
4966 	trace_netif_rx_entry(skb);
4967 	ret = netif_rx_internal(skb);
4968 	trace_netif_rx_exit(ret);
4969 	return ret;
4970 }
4971 EXPORT_SYMBOL(__netif_rx);
4972 
4973 /**
4974  *	netif_rx	-	post buffer to the network code
4975  *	@skb: buffer to post
4976  *
4977  *	This function receives a packet from a device driver and queues it for
4978  *	the upper (protocol) levels to process via the backlog NAPI device. It
4979  *	always succeeds. The buffer may be dropped during processing for
4980  *	congestion control or by the protocol layers.
4981  *	The network buffer is passed via the backlog NAPI device. Modern NIC
4982  *	driver should use NAPI and GRO.
4983  *	This function can used from interrupt and from process context. The
4984  *	caller from process context must not disable interrupts before invoking
4985  *	this function.
4986  *
4987  *	return values:
4988  *	NET_RX_SUCCESS	(no congestion)
4989  *	NET_RX_DROP     (packet was dropped)
4990  *
4991  */
4992 int netif_rx(struct sk_buff *skb)
4993 {
4994 	bool need_bh_off = !(hardirq_count() | softirq_count());
4995 	int ret;
4996 
4997 	if (need_bh_off)
4998 		local_bh_disable();
4999 	trace_netif_rx_entry(skb);
5000 	ret = netif_rx_internal(skb);
5001 	trace_netif_rx_exit(ret);
5002 	if (need_bh_off)
5003 		local_bh_enable();
5004 	return ret;
5005 }
5006 EXPORT_SYMBOL(netif_rx);
5007 
5008 static __latent_entropy void net_tx_action(struct softirq_action *h)
5009 {
5010 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5011 
5012 	if (sd->completion_queue) {
5013 		struct sk_buff *clist;
5014 
5015 		local_irq_disable();
5016 		clist = sd->completion_queue;
5017 		sd->completion_queue = NULL;
5018 		local_irq_enable();
5019 
5020 		while (clist) {
5021 			struct sk_buff *skb = clist;
5022 
5023 			clist = clist->next;
5024 
5025 			WARN_ON(refcount_read(&skb->users));
5026 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
5027 				trace_consume_skb(skb);
5028 			else
5029 				trace_kfree_skb(skb, net_tx_action,
5030 						SKB_DROP_REASON_NOT_SPECIFIED);
5031 
5032 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5033 				__kfree_skb(skb);
5034 			else
5035 				__kfree_skb_defer(skb);
5036 		}
5037 	}
5038 
5039 	if (sd->output_queue) {
5040 		struct Qdisc *head;
5041 
5042 		local_irq_disable();
5043 		head = sd->output_queue;
5044 		sd->output_queue = NULL;
5045 		sd->output_queue_tailp = &sd->output_queue;
5046 		local_irq_enable();
5047 
5048 		rcu_read_lock();
5049 
5050 		while (head) {
5051 			struct Qdisc *q = head;
5052 			spinlock_t *root_lock = NULL;
5053 
5054 			head = head->next_sched;
5055 
5056 			/* We need to make sure head->next_sched is read
5057 			 * before clearing __QDISC_STATE_SCHED
5058 			 */
5059 			smp_mb__before_atomic();
5060 
5061 			if (!(q->flags & TCQ_F_NOLOCK)) {
5062 				root_lock = qdisc_lock(q);
5063 				spin_lock(root_lock);
5064 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5065 						     &q->state))) {
5066 				/* There is a synchronize_net() between
5067 				 * STATE_DEACTIVATED flag being set and
5068 				 * qdisc_reset()/some_qdisc_is_busy() in
5069 				 * dev_deactivate(), so we can safely bail out
5070 				 * early here to avoid data race between
5071 				 * qdisc_deactivate() and some_qdisc_is_busy()
5072 				 * for lockless qdisc.
5073 				 */
5074 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5075 				continue;
5076 			}
5077 
5078 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5079 			qdisc_run(q);
5080 			if (root_lock)
5081 				spin_unlock(root_lock);
5082 		}
5083 
5084 		rcu_read_unlock();
5085 	}
5086 
5087 	xfrm_dev_backlog(sd);
5088 }
5089 
5090 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5091 /* This hook is defined here for ATM LANE */
5092 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5093 			     unsigned char *addr) __read_mostly;
5094 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5095 #endif
5096 
5097 static inline struct sk_buff *
5098 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5099 		   struct net_device *orig_dev, bool *another)
5100 {
5101 #ifdef CONFIG_NET_CLS_ACT
5102 	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5103 	struct tcf_result cl_res;
5104 
5105 	/* If there's at least one ingress present somewhere (so
5106 	 * we get here via enabled static key), remaining devices
5107 	 * that are not configured with an ingress qdisc will bail
5108 	 * out here.
5109 	 */
5110 	if (!miniq)
5111 		return skb;
5112 
5113 	if (*pt_prev) {
5114 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
5115 		*pt_prev = NULL;
5116 	}
5117 
5118 	qdisc_skb_cb(skb)->pkt_len = skb->len;
5119 	tc_skb_cb(skb)->mru = 0;
5120 	tc_skb_cb(skb)->post_ct = false;
5121 	skb->tc_at_ingress = 1;
5122 	mini_qdisc_bstats_cpu_update(miniq, skb);
5123 
5124 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5125 	case TC_ACT_OK:
5126 	case TC_ACT_RECLASSIFY:
5127 		skb->tc_index = TC_H_MIN(cl_res.classid);
5128 		break;
5129 	case TC_ACT_SHOT:
5130 		mini_qdisc_qstats_cpu_drop(miniq);
5131 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5132 		*ret = NET_RX_DROP;
5133 		return NULL;
5134 	case TC_ACT_STOLEN:
5135 	case TC_ACT_QUEUED:
5136 	case TC_ACT_TRAP:
5137 		consume_skb(skb);
5138 		*ret = NET_RX_SUCCESS;
5139 		return NULL;
5140 	case TC_ACT_REDIRECT:
5141 		/* skb_mac_header check was done by cls/act_bpf, so
5142 		 * we can safely push the L2 header back before
5143 		 * redirecting to another netdev
5144 		 */
5145 		__skb_push(skb, skb->mac_len);
5146 		if (skb_do_redirect(skb) == -EAGAIN) {
5147 			__skb_pull(skb, skb->mac_len);
5148 			*another = true;
5149 			break;
5150 		}
5151 		*ret = NET_RX_SUCCESS;
5152 		return NULL;
5153 	case TC_ACT_CONSUMED:
5154 		*ret = NET_RX_SUCCESS;
5155 		return NULL;
5156 	default:
5157 		break;
5158 	}
5159 #endif /* CONFIG_NET_CLS_ACT */
5160 	return skb;
5161 }
5162 
5163 /**
5164  *	netdev_is_rx_handler_busy - check if receive handler is registered
5165  *	@dev: device to check
5166  *
5167  *	Check if a receive handler is already registered for a given device.
5168  *	Return true if there one.
5169  *
5170  *	The caller must hold the rtnl_mutex.
5171  */
5172 bool netdev_is_rx_handler_busy(struct net_device *dev)
5173 {
5174 	ASSERT_RTNL();
5175 	return dev && rtnl_dereference(dev->rx_handler);
5176 }
5177 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5178 
5179 /**
5180  *	netdev_rx_handler_register - register receive handler
5181  *	@dev: device to register a handler for
5182  *	@rx_handler: receive handler to register
5183  *	@rx_handler_data: data pointer that is used by rx handler
5184  *
5185  *	Register a receive handler for a device. This handler will then be
5186  *	called from __netif_receive_skb. A negative errno code is returned
5187  *	on a failure.
5188  *
5189  *	The caller must hold the rtnl_mutex.
5190  *
5191  *	For a general description of rx_handler, see enum rx_handler_result.
5192  */
5193 int netdev_rx_handler_register(struct net_device *dev,
5194 			       rx_handler_func_t *rx_handler,
5195 			       void *rx_handler_data)
5196 {
5197 	if (netdev_is_rx_handler_busy(dev))
5198 		return -EBUSY;
5199 
5200 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5201 		return -EINVAL;
5202 
5203 	/* Note: rx_handler_data must be set before rx_handler */
5204 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5205 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5206 
5207 	return 0;
5208 }
5209 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5210 
5211 /**
5212  *	netdev_rx_handler_unregister - unregister receive handler
5213  *	@dev: device to unregister a handler from
5214  *
5215  *	Unregister a receive handler from a device.
5216  *
5217  *	The caller must hold the rtnl_mutex.
5218  */
5219 void netdev_rx_handler_unregister(struct net_device *dev)
5220 {
5221 
5222 	ASSERT_RTNL();
5223 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5224 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5225 	 * section has a guarantee to see a non NULL rx_handler_data
5226 	 * as well.
5227 	 */
5228 	synchronize_net();
5229 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5230 }
5231 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5232 
5233 /*
5234  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5235  * the special handling of PFMEMALLOC skbs.
5236  */
5237 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5238 {
5239 	switch (skb->protocol) {
5240 	case htons(ETH_P_ARP):
5241 	case htons(ETH_P_IP):
5242 	case htons(ETH_P_IPV6):
5243 	case htons(ETH_P_8021Q):
5244 	case htons(ETH_P_8021AD):
5245 		return true;
5246 	default:
5247 		return false;
5248 	}
5249 }
5250 
5251 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5252 			     int *ret, struct net_device *orig_dev)
5253 {
5254 	if (nf_hook_ingress_active(skb)) {
5255 		int ingress_retval;
5256 
5257 		if (*pt_prev) {
5258 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5259 			*pt_prev = NULL;
5260 		}
5261 
5262 		rcu_read_lock();
5263 		ingress_retval = nf_hook_ingress(skb);
5264 		rcu_read_unlock();
5265 		return ingress_retval;
5266 	}
5267 	return 0;
5268 }
5269 
5270 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5271 				    struct packet_type **ppt_prev)
5272 {
5273 	struct packet_type *ptype, *pt_prev;
5274 	rx_handler_func_t *rx_handler;
5275 	struct sk_buff *skb = *pskb;
5276 	struct net_device *orig_dev;
5277 	bool deliver_exact = false;
5278 	int ret = NET_RX_DROP;
5279 	__be16 type;
5280 
5281 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5282 
5283 	trace_netif_receive_skb(skb);
5284 
5285 	orig_dev = skb->dev;
5286 
5287 	skb_reset_network_header(skb);
5288 	if (!skb_transport_header_was_set(skb))
5289 		skb_reset_transport_header(skb);
5290 	skb_reset_mac_len(skb);
5291 
5292 	pt_prev = NULL;
5293 
5294 another_round:
5295 	skb->skb_iif = skb->dev->ifindex;
5296 
5297 	__this_cpu_inc(softnet_data.processed);
5298 
5299 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5300 		int ret2;
5301 
5302 		migrate_disable();
5303 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5304 		migrate_enable();
5305 
5306 		if (ret2 != XDP_PASS) {
5307 			ret = NET_RX_DROP;
5308 			goto out;
5309 		}
5310 	}
5311 
5312 	if (eth_type_vlan(skb->protocol)) {
5313 		skb = skb_vlan_untag(skb);
5314 		if (unlikely(!skb))
5315 			goto out;
5316 	}
5317 
5318 	if (skb_skip_tc_classify(skb))
5319 		goto skip_classify;
5320 
5321 	if (pfmemalloc)
5322 		goto skip_taps;
5323 
5324 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5325 		if (pt_prev)
5326 			ret = deliver_skb(skb, pt_prev, orig_dev);
5327 		pt_prev = ptype;
5328 	}
5329 
5330 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5331 		if (pt_prev)
5332 			ret = deliver_skb(skb, pt_prev, orig_dev);
5333 		pt_prev = ptype;
5334 	}
5335 
5336 skip_taps:
5337 #ifdef CONFIG_NET_INGRESS
5338 	if (static_branch_unlikely(&ingress_needed_key)) {
5339 		bool another = false;
5340 
5341 		nf_skip_egress(skb, true);
5342 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5343 					 &another);
5344 		if (another)
5345 			goto another_round;
5346 		if (!skb)
5347 			goto out;
5348 
5349 		nf_skip_egress(skb, false);
5350 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5351 			goto out;
5352 	}
5353 #endif
5354 	skb_reset_redirect(skb);
5355 skip_classify:
5356 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5357 		goto drop;
5358 
5359 	if (skb_vlan_tag_present(skb)) {
5360 		if (pt_prev) {
5361 			ret = deliver_skb(skb, pt_prev, orig_dev);
5362 			pt_prev = NULL;
5363 		}
5364 		if (vlan_do_receive(&skb))
5365 			goto another_round;
5366 		else if (unlikely(!skb))
5367 			goto out;
5368 	}
5369 
5370 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5371 	if (rx_handler) {
5372 		if (pt_prev) {
5373 			ret = deliver_skb(skb, pt_prev, orig_dev);
5374 			pt_prev = NULL;
5375 		}
5376 		switch (rx_handler(&skb)) {
5377 		case RX_HANDLER_CONSUMED:
5378 			ret = NET_RX_SUCCESS;
5379 			goto out;
5380 		case RX_HANDLER_ANOTHER:
5381 			goto another_round;
5382 		case RX_HANDLER_EXACT:
5383 			deliver_exact = true;
5384 			break;
5385 		case RX_HANDLER_PASS:
5386 			break;
5387 		default:
5388 			BUG();
5389 		}
5390 	}
5391 
5392 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5393 check_vlan_id:
5394 		if (skb_vlan_tag_get_id(skb)) {
5395 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5396 			 * find vlan device.
5397 			 */
5398 			skb->pkt_type = PACKET_OTHERHOST;
5399 		} else if (eth_type_vlan(skb->protocol)) {
5400 			/* Outer header is 802.1P with vlan 0, inner header is
5401 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5402 			 * not find vlan dev for vlan id 0.
5403 			 */
5404 			__vlan_hwaccel_clear_tag(skb);
5405 			skb = skb_vlan_untag(skb);
5406 			if (unlikely(!skb))
5407 				goto out;
5408 			if (vlan_do_receive(&skb))
5409 				/* After stripping off 802.1P header with vlan 0
5410 				 * vlan dev is found for inner header.
5411 				 */
5412 				goto another_round;
5413 			else if (unlikely(!skb))
5414 				goto out;
5415 			else
5416 				/* We have stripped outer 802.1P vlan 0 header.
5417 				 * But could not find vlan dev.
5418 				 * check again for vlan id to set OTHERHOST.
5419 				 */
5420 				goto check_vlan_id;
5421 		}
5422 		/* Note: we might in the future use prio bits
5423 		 * and set skb->priority like in vlan_do_receive()
5424 		 * For the time being, just ignore Priority Code Point
5425 		 */
5426 		__vlan_hwaccel_clear_tag(skb);
5427 	}
5428 
5429 	type = skb->protocol;
5430 
5431 	/* deliver only exact match when indicated */
5432 	if (likely(!deliver_exact)) {
5433 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5434 				       &ptype_base[ntohs(type) &
5435 						   PTYPE_HASH_MASK]);
5436 	}
5437 
5438 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5439 			       &orig_dev->ptype_specific);
5440 
5441 	if (unlikely(skb->dev != orig_dev)) {
5442 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5443 				       &skb->dev->ptype_specific);
5444 	}
5445 
5446 	if (pt_prev) {
5447 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5448 			goto drop;
5449 		*ppt_prev = pt_prev;
5450 	} else {
5451 drop:
5452 		if (!deliver_exact)
5453 			dev_core_stats_rx_dropped_inc(skb->dev);
5454 		else
5455 			dev_core_stats_rx_nohandler_inc(skb->dev);
5456 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5457 		/* Jamal, now you will not able to escape explaining
5458 		 * me how you were going to use this. :-)
5459 		 */
5460 		ret = NET_RX_DROP;
5461 	}
5462 
5463 out:
5464 	/* The invariant here is that if *ppt_prev is not NULL
5465 	 * then skb should also be non-NULL.
5466 	 *
5467 	 * Apparently *ppt_prev assignment above holds this invariant due to
5468 	 * skb dereferencing near it.
5469 	 */
5470 	*pskb = skb;
5471 	return ret;
5472 }
5473 
5474 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5475 {
5476 	struct net_device *orig_dev = skb->dev;
5477 	struct packet_type *pt_prev = NULL;
5478 	int ret;
5479 
5480 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5481 	if (pt_prev)
5482 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5483 					 skb->dev, pt_prev, orig_dev);
5484 	return ret;
5485 }
5486 
5487 /**
5488  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5489  *	@skb: buffer to process
5490  *
5491  *	More direct receive version of netif_receive_skb().  It should
5492  *	only be used by callers that have a need to skip RPS and Generic XDP.
5493  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5494  *
5495  *	This function may only be called from softirq context and interrupts
5496  *	should be enabled.
5497  *
5498  *	Return values (usually ignored):
5499  *	NET_RX_SUCCESS: no congestion
5500  *	NET_RX_DROP: packet was dropped
5501  */
5502 int netif_receive_skb_core(struct sk_buff *skb)
5503 {
5504 	int ret;
5505 
5506 	rcu_read_lock();
5507 	ret = __netif_receive_skb_one_core(skb, false);
5508 	rcu_read_unlock();
5509 
5510 	return ret;
5511 }
5512 EXPORT_SYMBOL(netif_receive_skb_core);
5513 
5514 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5515 						  struct packet_type *pt_prev,
5516 						  struct net_device *orig_dev)
5517 {
5518 	struct sk_buff *skb, *next;
5519 
5520 	if (!pt_prev)
5521 		return;
5522 	if (list_empty(head))
5523 		return;
5524 	if (pt_prev->list_func != NULL)
5525 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5526 				   ip_list_rcv, head, pt_prev, orig_dev);
5527 	else
5528 		list_for_each_entry_safe(skb, next, head, list) {
5529 			skb_list_del_init(skb);
5530 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5531 		}
5532 }
5533 
5534 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5535 {
5536 	/* Fast-path assumptions:
5537 	 * - There is no RX handler.
5538 	 * - Only one packet_type matches.
5539 	 * If either of these fails, we will end up doing some per-packet
5540 	 * processing in-line, then handling the 'last ptype' for the whole
5541 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5542 	 * because the 'last ptype' must be constant across the sublist, and all
5543 	 * other ptypes are handled per-packet.
5544 	 */
5545 	/* Current (common) ptype of sublist */
5546 	struct packet_type *pt_curr = NULL;
5547 	/* Current (common) orig_dev of sublist */
5548 	struct net_device *od_curr = NULL;
5549 	struct list_head sublist;
5550 	struct sk_buff *skb, *next;
5551 
5552 	INIT_LIST_HEAD(&sublist);
5553 	list_for_each_entry_safe(skb, next, head, list) {
5554 		struct net_device *orig_dev = skb->dev;
5555 		struct packet_type *pt_prev = NULL;
5556 
5557 		skb_list_del_init(skb);
5558 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5559 		if (!pt_prev)
5560 			continue;
5561 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5562 			/* dispatch old sublist */
5563 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5564 			/* start new sublist */
5565 			INIT_LIST_HEAD(&sublist);
5566 			pt_curr = pt_prev;
5567 			od_curr = orig_dev;
5568 		}
5569 		list_add_tail(&skb->list, &sublist);
5570 	}
5571 
5572 	/* dispatch final sublist */
5573 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5574 }
5575 
5576 static int __netif_receive_skb(struct sk_buff *skb)
5577 {
5578 	int ret;
5579 
5580 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5581 		unsigned int noreclaim_flag;
5582 
5583 		/*
5584 		 * PFMEMALLOC skbs are special, they should
5585 		 * - be delivered to SOCK_MEMALLOC sockets only
5586 		 * - stay away from userspace
5587 		 * - have bounded memory usage
5588 		 *
5589 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5590 		 * context down to all allocation sites.
5591 		 */
5592 		noreclaim_flag = memalloc_noreclaim_save();
5593 		ret = __netif_receive_skb_one_core(skb, true);
5594 		memalloc_noreclaim_restore(noreclaim_flag);
5595 	} else
5596 		ret = __netif_receive_skb_one_core(skb, false);
5597 
5598 	return ret;
5599 }
5600 
5601 static void __netif_receive_skb_list(struct list_head *head)
5602 {
5603 	unsigned long noreclaim_flag = 0;
5604 	struct sk_buff *skb, *next;
5605 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5606 
5607 	list_for_each_entry_safe(skb, next, head, list) {
5608 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5609 			struct list_head sublist;
5610 
5611 			/* Handle the previous sublist */
5612 			list_cut_before(&sublist, head, &skb->list);
5613 			if (!list_empty(&sublist))
5614 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5615 			pfmemalloc = !pfmemalloc;
5616 			/* See comments in __netif_receive_skb */
5617 			if (pfmemalloc)
5618 				noreclaim_flag = memalloc_noreclaim_save();
5619 			else
5620 				memalloc_noreclaim_restore(noreclaim_flag);
5621 		}
5622 	}
5623 	/* Handle the remaining sublist */
5624 	if (!list_empty(head))
5625 		__netif_receive_skb_list_core(head, pfmemalloc);
5626 	/* Restore pflags */
5627 	if (pfmemalloc)
5628 		memalloc_noreclaim_restore(noreclaim_flag);
5629 }
5630 
5631 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5632 {
5633 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5634 	struct bpf_prog *new = xdp->prog;
5635 	int ret = 0;
5636 
5637 	switch (xdp->command) {
5638 	case XDP_SETUP_PROG:
5639 		rcu_assign_pointer(dev->xdp_prog, new);
5640 		if (old)
5641 			bpf_prog_put(old);
5642 
5643 		if (old && !new) {
5644 			static_branch_dec(&generic_xdp_needed_key);
5645 		} else if (new && !old) {
5646 			static_branch_inc(&generic_xdp_needed_key);
5647 			dev_disable_lro(dev);
5648 			dev_disable_gro_hw(dev);
5649 		}
5650 		break;
5651 
5652 	default:
5653 		ret = -EINVAL;
5654 		break;
5655 	}
5656 
5657 	return ret;
5658 }
5659 
5660 static int netif_receive_skb_internal(struct sk_buff *skb)
5661 {
5662 	int ret;
5663 
5664 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5665 
5666 	if (skb_defer_rx_timestamp(skb))
5667 		return NET_RX_SUCCESS;
5668 
5669 	rcu_read_lock();
5670 #ifdef CONFIG_RPS
5671 	if (static_branch_unlikely(&rps_needed)) {
5672 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5673 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5674 
5675 		if (cpu >= 0) {
5676 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5677 			rcu_read_unlock();
5678 			return ret;
5679 		}
5680 	}
5681 #endif
5682 	ret = __netif_receive_skb(skb);
5683 	rcu_read_unlock();
5684 	return ret;
5685 }
5686 
5687 void netif_receive_skb_list_internal(struct list_head *head)
5688 {
5689 	struct sk_buff *skb, *next;
5690 	struct list_head sublist;
5691 
5692 	INIT_LIST_HEAD(&sublist);
5693 	list_for_each_entry_safe(skb, next, head, list) {
5694 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5695 		skb_list_del_init(skb);
5696 		if (!skb_defer_rx_timestamp(skb))
5697 			list_add_tail(&skb->list, &sublist);
5698 	}
5699 	list_splice_init(&sublist, head);
5700 
5701 	rcu_read_lock();
5702 #ifdef CONFIG_RPS
5703 	if (static_branch_unlikely(&rps_needed)) {
5704 		list_for_each_entry_safe(skb, next, head, list) {
5705 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5706 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5707 
5708 			if (cpu >= 0) {
5709 				/* Will be handled, remove from list */
5710 				skb_list_del_init(skb);
5711 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5712 			}
5713 		}
5714 	}
5715 #endif
5716 	__netif_receive_skb_list(head);
5717 	rcu_read_unlock();
5718 }
5719 
5720 /**
5721  *	netif_receive_skb - process receive buffer from network
5722  *	@skb: buffer to process
5723  *
5724  *	netif_receive_skb() is the main receive data processing function.
5725  *	It always succeeds. The buffer may be dropped during processing
5726  *	for congestion control or by the protocol layers.
5727  *
5728  *	This function may only be called from softirq context and interrupts
5729  *	should be enabled.
5730  *
5731  *	Return values (usually ignored):
5732  *	NET_RX_SUCCESS: no congestion
5733  *	NET_RX_DROP: packet was dropped
5734  */
5735 int netif_receive_skb(struct sk_buff *skb)
5736 {
5737 	int ret;
5738 
5739 	trace_netif_receive_skb_entry(skb);
5740 
5741 	ret = netif_receive_skb_internal(skb);
5742 	trace_netif_receive_skb_exit(ret);
5743 
5744 	return ret;
5745 }
5746 EXPORT_SYMBOL(netif_receive_skb);
5747 
5748 /**
5749  *	netif_receive_skb_list - process many receive buffers from network
5750  *	@head: list of skbs to process.
5751  *
5752  *	Since return value of netif_receive_skb() is normally ignored, and
5753  *	wouldn't be meaningful for a list, this function returns void.
5754  *
5755  *	This function may only be called from softirq context and interrupts
5756  *	should be enabled.
5757  */
5758 void netif_receive_skb_list(struct list_head *head)
5759 {
5760 	struct sk_buff *skb;
5761 
5762 	if (list_empty(head))
5763 		return;
5764 	if (trace_netif_receive_skb_list_entry_enabled()) {
5765 		list_for_each_entry(skb, head, list)
5766 			trace_netif_receive_skb_list_entry(skb);
5767 	}
5768 	netif_receive_skb_list_internal(head);
5769 	trace_netif_receive_skb_list_exit(0);
5770 }
5771 EXPORT_SYMBOL(netif_receive_skb_list);
5772 
5773 static DEFINE_PER_CPU(struct work_struct, flush_works);
5774 
5775 /* Network device is going away, flush any packets still pending */
5776 static void flush_backlog(struct work_struct *work)
5777 {
5778 	struct sk_buff *skb, *tmp;
5779 	struct softnet_data *sd;
5780 
5781 	local_bh_disable();
5782 	sd = this_cpu_ptr(&softnet_data);
5783 
5784 	rps_lock_irq_disable(sd);
5785 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5786 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5787 			__skb_unlink(skb, &sd->input_pkt_queue);
5788 			dev_kfree_skb_irq(skb);
5789 			input_queue_head_incr(sd);
5790 		}
5791 	}
5792 	rps_unlock_irq_enable(sd);
5793 
5794 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5795 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5796 			__skb_unlink(skb, &sd->process_queue);
5797 			kfree_skb(skb);
5798 			input_queue_head_incr(sd);
5799 		}
5800 	}
5801 	local_bh_enable();
5802 }
5803 
5804 static bool flush_required(int cpu)
5805 {
5806 #if IS_ENABLED(CONFIG_RPS)
5807 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5808 	bool do_flush;
5809 
5810 	rps_lock_irq_disable(sd);
5811 
5812 	/* as insertion into process_queue happens with the rps lock held,
5813 	 * process_queue access may race only with dequeue
5814 	 */
5815 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5816 		   !skb_queue_empty_lockless(&sd->process_queue);
5817 	rps_unlock_irq_enable(sd);
5818 
5819 	return do_flush;
5820 #endif
5821 	/* without RPS we can't safely check input_pkt_queue: during a
5822 	 * concurrent remote skb_queue_splice() we can detect as empty both
5823 	 * input_pkt_queue and process_queue even if the latter could end-up
5824 	 * containing a lot of packets.
5825 	 */
5826 	return true;
5827 }
5828 
5829 static void flush_all_backlogs(void)
5830 {
5831 	static cpumask_t flush_cpus;
5832 	unsigned int cpu;
5833 
5834 	/* since we are under rtnl lock protection we can use static data
5835 	 * for the cpumask and avoid allocating on stack the possibly
5836 	 * large mask
5837 	 */
5838 	ASSERT_RTNL();
5839 
5840 	cpus_read_lock();
5841 
5842 	cpumask_clear(&flush_cpus);
5843 	for_each_online_cpu(cpu) {
5844 		if (flush_required(cpu)) {
5845 			queue_work_on(cpu, system_highpri_wq,
5846 				      per_cpu_ptr(&flush_works, cpu));
5847 			cpumask_set_cpu(cpu, &flush_cpus);
5848 		}
5849 	}
5850 
5851 	/* we can have in flight packet[s] on the cpus we are not flushing,
5852 	 * synchronize_net() in unregister_netdevice_many() will take care of
5853 	 * them
5854 	 */
5855 	for_each_cpu(cpu, &flush_cpus)
5856 		flush_work(per_cpu_ptr(&flush_works, cpu));
5857 
5858 	cpus_read_unlock();
5859 }
5860 
5861 static void net_rps_send_ipi(struct softnet_data *remsd)
5862 {
5863 #ifdef CONFIG_RPS
5864 	while (remsd) {
5865 		struct softnet_data *next = remsd->rps_ipi_next;
5866 
5867 		if (cpu_online(remsd->cpu))
5868 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5869 		remsd = next;
5870 	}
5871 #endif
5872 }
5873 
5874 /*
5875  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5876  * Note: called with local irq disabled, but exits with local irq enabled.
5877  */
5878 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5879 {
5880 #ifdef CONFIG_RPS
5881 	struct softnet_data *remsd = sd->rps_ipi_list;
5882 
5883 	if (remsd) {
5884 		sd->rps_ipi_list = NULL;
5885 
5886 		local_irq_enable();
5887 
5888 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5889 		net_rps_send_ipi(remsd);
5890 	} else
5891 #endif
5892 		local_irq_enable();
5893 }
5894 
5895 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5896 {
5897 #ifdef CONFIG_RPS
5898 	return sd->rps_ipi_list != NULL;
5899 #else
5900 	return false;
5901 #endif
5902 }
5903 
5904 static int process_backlog(struct napi_struct *napi, int quota)
5905 {
5906 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5907 	bool again = true;
5908 	int work = 0;
5909 
5910 	/* Check if we have pending ipi, its better to send them now,
5911 	 * not waiting net_rx_action() end.
5912 	 */
5913 	if (sd_has_rps_ipi_waiting(sd)) {
5914 		local_irq_disable();
5915 		net_rps_action_and_irq_enable(sd);
5916 	}
5917 
5918 	napi->weight = READ_ONCE(dev_rx_weight);
5919 	while (again) {
5920 		struct sk_buff *skb;
5921 
5922 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5923 			rcu_read_lock();
5924 			__netif_receive_skb(skb);
5925 			rcu_read_unlock();
5926 			input_queue_head_incr(sd);
5927 			if (++work >= quota)
5928 				return work;
5929 
5930 		}
5931 
5932 		rps_lock_irq_disable(sd);
5933 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5934 			/*
5935 			 * Inline a custom version of __napi_complete().
5936 			 * only current cpu owns and manipulates this napi,
5937 			 * and NAPI_STATE_SCHED is the only possible flag set
5938 			 * on backlog.
5939 			 * We can use a plain write instead of clear_bit(),
5940 			 * and we dont need an smp_mb() memory barrier.
5941 			 */
5942 			napi->state = 0;
5943 			again = false;
5944 		} else {
5945 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5946 						   &sd->process_queue);
5947 		}
5948 		rps_unlock_irq_enable(sd);
5949 	}
5950 
5951 	return work;
5952 }
5953 
5954 /**
5955  * __napi_schedule - schedule for receive
5956  * @n: entry to schedule
5957  *
5958  * The entry's receive function will be scheduled to run.
5959  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5960  */
5961 void __napi_schedule(struct napi_struct *n)
5962 {
5963 	unsigned long flags;
5964 
5965 	local_irq_save(flags);
5966 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
5967 	local_irq_restore(flags);
5968 }
5969 EXPORT_SYMBOL(__napi_schedule);
5970 
5971 /**
5972  *	napi_schedule_prep - check if napi can be scheduled
5973  *	@n: napi context
5974  *
5975  * Test if NAPI routine is already running, and if not mark
5976  * it as running.  This is used as a condition variable to
5977  * insure only one NAPI poll instance runs.  We also make
5978  * sure there is no pending NAPI disable.
5979  */
5980 bool napi_schedule_prep(struct napi_struct *n)
5981 {
5982 	unsigned long new, val = READ_ONCE(n->state);
5983 
5984 	do {
5985 		if (unlikely(val & NAPIF_STATE_DISABLE))
5986 			return false;
5987 		new = val | NAPIF_STATE_SCHED;
5988 
5989 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
5990 		 * This was suggested by Alexander Duyck, as compiler
5991 		 * emits better code than :
5992 		 * if (val & NAPIF_STATE_SCHED)
5993 		 *     new |= NAPIF_STATE_MISSED;
5994 		 */
5995 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
5996 						   NAPIF_STATE_MISSED;
5997 	} while (!try_cmpxchg(&n->state, &val, new));
5998 
5999 	return !(val & NAPIF_STATE_SCHED);
6000 }
6001 EXPORT_SYMBOL(napi_schedule_prep);
6002 
6003 /**
6004  * __napi_schedule_irqoff - schedule for receive
6005  * @n: entry to schedule
6006  *
6007  * Variant of __napi_schedule() assuming hard irqs are masked.
6008  *
6009  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6010  * because the interrupt disabled assumption might not be true
6011  * due to force-threaded interrupts and spinlock substitution.
6012  */
6013 void __napi_schedule_irqoff(struct napi_struct *n)
6014 {
6015 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6016 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6017 	else
6018 		__napi_schedule(n);
6019 }
6020 EXPORT_SYMBOL(__napi_schedule_irqoff);
6021 
6022 bool napi_complete_done(struct napi_struct *n, int work_done)
6023 {
6024 	unsigned long flags, val, new, timeout = 0;
6025 	bool ret = true;
6026 
6027 	/*
6028 	 * 1) Don't let napi dequeue from the cpu poll list
6029 	 *    just in case its running on a different cpu.
6030 	 * 2) If we are busy polling, do nothing here, we have
6031 	 *    the guarantee we will be called later.
6032 	 */
6033 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6034 				 NAPIF_STATE_IN_BUSY_POLL)))
6035 		return false;
6036 
6037 	if (work_done) {
6038 		if (n->gro_bitmask)
6039 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6040 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6041 	}
6042 	if (n->defer_hard_irqs_count > 0) {
6043 		n->defer_hard_irqs_count--;
6044 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6045 		if (timeout)
6046 			ret = false;
6047 	}
6048 	if (n->gro_bitmask) {
6049 		/* When the NAPI instance uses a timeout and keeps postponing
6050 		 * it, we need to bound somehow the time packets are kept in
6051 		 * the GRO layer
6052 		 */
6053 		napi_gro_flush(n, !!timeout);
6054 	}
6055 
6056 	gro_normal_list(n);
6057 
6058 	if (unlikely(!list_empty(&n->poll_list))) {
6059 		/* If n->poll_list is not empty, we need to mask irqs */
6060 		local_irq_save(flags);
6061 		list_del_init(&n->poll_list);
6062 		local_irq_restore(flags);
6063 	}
6064 
6065 	val = READ_ONCE(n->state);
6066 	do {
6067 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6068 
6069 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6070 			      NAPIF_STATE_SCHED_THREADED |
6071 			      NAPIF_STATE_PREFER_BUSY_POLL);
6072 
6073 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6074 		 * because we will call napi->poll() one more time.
6075 		 * This C code was suggested by Alexander Duyck to help gcc.
6076 		 */
6077 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6078 						    NAPIF_STATE_SCHED;
6079 	} while (!try_cmpxchg(&n->state, &val, new));
6080 
6081 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6082 		__napi_schedule(n);
6083 		return false;
6084 	}
6085 
6086 	if (timeout)
6087 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6088 			      HRTIMER_MODE_REL_PINNED);
6089 	return ret;
6090 }
6091 EXPORT_SYMBOL(napi_complete_done);
6092 
6093 /* must be called under rcu_read_lock(), as we dont take a reference */
6094 static struct napi_struct *napi_by_id(unsigned int napi_id)
6095 {
6096 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6097 	struct napi_struct *napi;
6098 
6099 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6100 		if (napi->napi_id == napi_id)
6101 			return napi;
6102 
6103 	return NULL;
6104 }
6105 
6106 #if defined(CONFIG_NET_RX_BUSY_POLL)
6107 
6108 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6109 {
6110 	if (!skip_schedule) {
6111 		gro_normal_list(napi);
6112 		__napi_schedule(napi);
6113 		return;
6114 	}
6115 
6116 	if (napi->gro_bitmask) {
6117 		/* flush too old packets
6118 		 * If HZ < 1000, flush all packets.
6119 		 */
6120 		napi_gro_flush(napi, HZ >= 1000);
6121 	}
6122 
6123 	gro_normal_list(napi);
6124 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6125 }
6126 
6127 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6128 			   u16 budget)
6129 {
6130 	bool skip_schedule = false;
6131 	unsigned long timeout;
6132 	int rc;
6133 
6134 	/* Busy polling means there is a high chance device driver hard irq
6135 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6136 	 * set in napi_schedule_prep().
6137 	 * Since we are about to call napi->poll() once more, we can safely
6138 	 * clear NAPI_STATE_MISSED.
6139 	 *
6140 	 * Note: x86 could use a single "lock and ..." instruction
6141 	 * to perform these two clear_bit()
6142 	 */
6143 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6144 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6145 
6146 	local_bh_disable();
6147 
6148 	if (prefer_busy_poll) {
6149 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6150 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6151 		if (napi->defer_hard_irqs_count && timeout) {
6152 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6153 			skip_schedule = true;
6154 		}
6155 	}
6156 
6157 	/* All we really want here is to re-enable device interrupts.
6158 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6159 	 */
6160 	rc = napi->poll(napi, budget);
6161 	/* We can't gro_normal_list() here, because napi->poll() might have
6162 	 * rearmed the napi (napi_complete_done()) in which case it could
6163 	 * already be running on another CPU.
6164 	 */
6165 	trace_napi_poll(napi, rc, budget);
6166 	netpoll_poll_unlock(have_poll_lock);
6167 	if (rc == budget)
6168 		__busy_poll_stop(napi, skip_schedule);
6169 	local_bh_enable();
6170 }
6171 
6172 void napi_busy_loop(unsigned int napi_id,
6173 		    bool (*loop_end)(void *, unsigned long),
6174 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6175 {
6176 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6177 	int (*napi_poll)(struct napi_struct *napi, int budget);
6178 	void *have_poll_lock = NULL;
6179 	struct napi_struct *napi;
6180 
6181 restart:
6182 	napi_poll = NULL;
6183 
6184 	rcu_read_lock();
6185 
6186 	napi = napi_by_id(napi_id);
6187 	if (!napi)
6188 		goto out;
6189 
6190 	preempt_disable();
6191 	for (;;) {
6192 		int work = 0;
6193 
6194 		local_bh_disable();
6195 		if (!napi_poll) {
6196 			unsigned long val = READ_ONCE(napi->state);
6197 
6198 			/* If multiple threads are competing for this napi,
6199 			 * we avoid dirtying napi->state as much as we can.
6200 			 */
6201 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6202 				   NAPIF_STATE_IN_BUSY_POLL)) {
6203 				if (prefer_busy_poll)
6204 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6205 				goto count;
6206 			}
6207 			if (cmpxchg(&napi->state, val,
6208 				    val | NAPIF_STATE_IN_BUSY_POLL |
6209 					  NAPIF_STATE_SCHED) != val) {
6210 				if (prefer_busy_poll)
6211 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6212 				goto count;
6213 			}
6214 			have_poll_lock = netpoll_poll_lock(napi);
6215 			napi_poll = napi->poll;
6216 		}
6217 		work = napi_poll(napi, budget);
6218 		trace_napi_poll(napi, work, budget);
6219 		gro_normal_list(napi);
6220 count:
6221 		if (work > 0)
6222 			__NET_ADD_STATS(dev_net(napi->dev),
6223 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6224 		local_bh_enable();
6225 
6226 		if (!loop_end || loop_end(loop_end_arg, start_time))
6227 			break;
6228 
6229 		if (unlikely(need_resched())) {
6230 			if (napi_poll)
6231 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6232 			preempt_enable();
6233 			rcu_read_unlock();
6234 			cond_resched();
6235 			if (loop_end(loop_end_arg, start_time))
6236 				return;
6237 			goto restart;
6238 		}
6239 		cpu_relax();
6240 	}
6241 	if (napi_poll)
6242 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6243 	preempt_enable();
6244 out:
6245 	rcu_read_unlock();
6246 }
6247 EXPORT_SYMBOL(napi_busy_loop);
6248 
6249 #endif /* CONFIG_NET_RX_BUSY_POLL */
6250 
6251 static void napi_hash_add(struct napi_struct *napi)
6252 {
6253 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6254 		return;
6255 
6256 	spin_lock(&napi_hash_lock);
6257 
6258 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6259 	do {
6260 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6261 			napi_gen_id = MIN_NAPI_ID;
6262 	} while (napi_by_id(napi_gen_id));
6263 	napi->napi_id = napi_gen_id;
6264 
6265 	hlist_add_head_rcu(&napi->napi_hash_node,
6266 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6267 
6268 	spin_unlock(&napi_hash_lock);
6269 }
6270 
6271 /* Warning : caller is responsible to make sure rcu grace period
6272  * is respected before freeing memory containing @napi
6273  */
6274 static void napi_hash_del(struct napi_struct *napi)
6275 {
6276 	spin_lock(&napi_hash_lock);
6277 
6278 	hlist_del_init_rcu(&napi->napi_hash_node);
6279 
6280 	spin_unlock(&napi_hash_lock);
6281 }
6282 
6283 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6284 {
6285 	struct napi_struct *napi;
6286 
6287 	napi = container_of(timer, struct napi_struct, timer);
6288 
6289 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6290 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6291 	 */
6292 	if (!napi_disable_pending(napi) &&
6293 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6294 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6295 		__napi_schedule_irqoff(napi);
6296 	}
6297 
6298 	return HRTIMER_NORESTART;
6299 }
6300 
6301 static void init_gro_hash(struct napi_struct *napi)
6302 {
6303 	int i;
6304 
6305 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6306 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6307 		napi->gro_hash[i].count = 0;
6308 	}
6309 	napi->gro_bitmask = 0;
6310 }
6311 
6312 int dev_set_threaded(struct net_device *dev, bool threaded)
6313 {
6314 	struct napi_struct *napi;
6315 	int err = 0;
6316 
6317 	if (dev->threaded == threaded)
6318 		return 0;
6319 
6320 	if (threaded) {
6321 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6322 			if (!napi->thread) {
6323 				err = napi_kthread_create(napi);
6324 				if (err) {
6325 					threaded = false;
6326 					break;
6327 				}
6328 			}
6329 		}
6330 	}
6331 
6332 	dev->threaded = threaded;
6333 
6334 	/* Make sure kthread is created before THREADED bit
6335 	 * is set.
6336 	 */
6337 	smp_mb__before_atomic();
6338 
6339 	/* Setting/unsetting threaded mode on a napi might not immediately
6340 	 * take effect, if the current napi instance is actively being
6341 	 * polled. In this case, the switch between threaded mode and
6342 	 * softirq mode will happen in the next round of napi_schedule().
6343 	 * This should not cause hiccups/stalls to the live traffic.
6344 	 */
6345 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
6346 		if (threaded)
6347 			set_bit(NAPI_STATE_THREADED, &napi->state);
6348 		else
6349 			clear_bit(NAPI_STATE_THREADED, &napi->state);
6350 	}
6351 
6352 	return err;
6353 }
6354 EXPORT_SYMBOL(dev_set_threaded);
6355 
6356 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6357 			   int (*poll)(struct napi_struct *, int), int weight)
6358 {
6359 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6360 		return;
6361 
6362 	INIT_LIST_HEAD(&napi->poll_list);
6363 	INIT_HLIST_NODE(&napi->napi_hash_node);
6364 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6365 	napi->timer.function = napi_watchdog;
6366 	init_gro_hash(napi);
6367 	napi->skb = NULL;
6368 	INIT_LIST_HEAD(&napi->rx_list);
6369 	napi->rx_count = 0;
6370 	napi->poll = poll;
6371 	if (weight > NAPI_POLL_WEIGHT)
6372 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6373 				weight);
6374 	napi->weight = weight;
6375 	napi->dev = dev;
6376 #ifdef CONFIG_NETPOLL
6377 	napi->poll_owner = -1;
6378 #endif
6379 	set_bit(NAPI_STATE_SCHED, &napi->state);
6380 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6381 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6382 	napi_hash_add(napi);
6383 	napi_get_frags_check(napi);
6384 	/* Create kthread for this napi if dev->threaded is set.
6385 	 * Clear dev->threaded if kthread creation failed so that
6386 	 * threaded mode will not be enabled in napi_enable().
6387 	 */
6388 	if (dev->threaded && napi_kthread_create(napi))
6389 		dev->threaded = 0;
6390 }
6391 EXPORT_SYMBOL(netif_napi_add_weight);
6392 
6393 void napi_disable(struct napi_struct *n)
6394 {
6395 	unsigned long val, new;
6396 
6397 	might_sleep();
6398 	set_bit(NAPI_STATE_DISABLE, &n->state);
6399 
6400 	val = READ_ONCE(n->state);
6401 	do {
6402 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6403 			usleep_range(20, 200);
6404 			val = READ_ONCE(n->state);
6405 		}
6406 
6407 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6408 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6409 	} while (!try_cmpxchg(&n->state, &val, new));
6410 
6411 	hrtimer_cancel(&n->timer);
6412 
6413 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6414 }
6415 EXPORT_SYMBOL(napi_disable);
6416 
6417 /**
6418  *	napi_enable - enable NAPI scheduling
6419  *	@n: NAPI context
6420  *
6421  * Resume NAPI from being scheduled on this context.
6422  * Must be paired with napi_disable.
6423  */
6424 void napi_enable(struct napi_struct *n)
6425 {
6426 	unsigned long new, val = READ_ONCE(n->state);
6427 
6428 	do {
6429 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6430 
6431 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6432 		if (n->dev->threaded && n->thread)
6433 			new |= NAPIF_STATE_THREADED;
6434 	} while (!try_cmpxchg(&n->state, &val, new));
6435 }
6436 EXPORT_SYMBOL(napi_enable);
6437 
6438 static void flush_gro_hash(struct napi_struct *napi)
6439 {
6440 	int i;
6441 
6442 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6443 		struct sk_buff *skb, *n;
6444 
6445 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6446 			kfree_skb(skb);
6447 		napi->gro_hash[i].count = 0;
6448 	}
6449 }
6450 
6451 /* Must be called in process context */
6452 void __netif_napi_del(struct napi_struct *napi)
6453 {
6454 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6455 		return;
6456 
6457 	napi_hash_del(napi);
6458 	list_del_rcu(&napi->dev_list);
6459 	napi_free_frags(napi);
6460 
6461 	flush_gro_hash(napi);
6462 	napi->gro_bitmask = 0;
6463 
6464 	if (napi->thread) {
6465 		kthread_stop(napi->thread);
6466 		napi->thread = NULL;
6467 	}
6468 }
6469 EXPORT_SYMBOL(__netif_napi_del);
6470 
6471 static int __napi_poll(struct napi_struct *n, bool *repoll)
6472 {
6473 	int work, weight;
6474 
6475 	weight = n->weight;
6476 
6477 	/* This NAPI_STATE_SCHED test is for avoiding a race
6478 	 * with netpoll's poll_napi().  Only the entity which
6479 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6480 	 * actually make the ->poll() call.  Therefore we avoid
6481 	 * accidentally calling ->poll() when NAPI is not scheduled.
6482 	 */
6483 	work = 0;
6484 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6485 		work = n->poll(n, weight);
6486 		trace_napi_poll(n, work, weight);
6487 	}
6488 
6489 	if (unlikely(work > weight))
6490 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6491 				n->poll, work, weight);
6492 
6493 	if (likely(work < weight))
6494 		return work;
6495 
6496 	/* Drivers must not modify the NAPI state if they
6497 	 * consume the entire weight.  In such cases this code
6498 	 * still "owns" the NAPI instance and therefore can
6499 	 * move the instance around on the list at-will.
6500 	 */
6501 	if (unlikely(napi_disable_pending(n))) {
6502 		napi_complete(n);
6503 		return work;
6504 	}
6505 
6506 	/* The NAPI context has more processing work, but busy-polling
6507 	 * is preferred. Exit early.
6508 	 */
6509 	if (napi_prefer_busy_poll(n)) {
6510 		if (napi_complete_done(n, work)) {
6511 			/* If timeout is not set, we need to make sure
6512 			 * that the NAPI is re-scheduled.
6513 			 */
6514 			napi_schedule(n);
6515 		}
6516 		return work;
6517 	}
6518 
6519 	if (n->gro_bitmask) {
6520 		/* flush too old packets
6521 		 * If HZ < 1000, flush all packets.
6522 		 */
6523 		napi_gro_flush(n, HZ >= 1000);
6524 	}
6525 
6526 	gro_normal_list(n);
6527 
6528 	/* Some drivers may have called napi_schedule
6529 	 * prior to exhausting their budget.
6530 	 */
6531 	if (unlikely(!list_empty(&n->poll_list))) {
6532 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6533 			     n->dev ? n->dev->name : "backlog");
6534 		return work;
6535 	}
6536 
6537 	*repoll = true;
6538 
6539 	return work;
6540 }
6541 
6542 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6543 {
6544 	bool do_repoll = false;
6545 	void *have;
6546 	int work;
6547 
6548 	list_del_init(&n->poll_list);
6549 
6550 	have = netpoll_poll_lock(n);
6551 
6552 	work = __napi_poll(n, &do_repoll);
6553 
6554 	if (do_repoll)
6555 		list_add_tail(&n->poll_list, repoll);
6556 
6557 	netpoll_poll_unlock(have);
6558 
6559 	return work;
6560 }
6561 
6562 static int napi_thread_wait(struct napi_struct *napi)
6563 {
6564 	bool woken = false;
6565 
6566 	set_current_state(TASK_INTERRUPTIBLE);
6567 
6568 	while (!kthread_should_stop()) {
6569 		/* Testing SCHED_THREADED bit here to make sure the current
6570 		 * kthread owns this napi and could poll on this napi.
6571 		 * Testing SCHED bit is not enough because SCHED bit might be
6572 		 * set by some other busy poll thread or by napi_disable().
6573 		 */
6574 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6575 			WARN_ON(!list_empty(&napi->poll_list));
6576 			__set_current_state(TASK_RUNNING);
6577 			return 0;
6578 		}
6579 
6580 		schedule();
6581 		/* woken being true indicates this thread owns this napi. */
6582 		woken = true;
6583 		set_current_state(TASK_INTERRUPTIBLE);
6584 	}
6585 	__set_current_state(TASK_RUNNING);
6586 
6587 	return -1;
6588 }
6589 
6590 static int napi_threaded_poll(void *data)
6591 {
6592 	struct napi_struct *napi = data;
6593 	void *have;
6594 
6595 	while (!napi_thread_wait(napi)) {
6596 		for (;;) {
6597 			bool repoll = false;
6598 
6599 			local_bh_disable();
6600 
6601 			have = netpoll_poll_lock(napi);
6602 			__napi_poll(napi, &repoll);
6603 			netpoll_poll_unlock(have);
6604 
6605 			local_bh_enable();
6606 
6607 			if (!repoll)
6608 				break;
6609 
6610 			cond_resched();
6611 		}
6612 	}
6613 	return 0;
6614 }
6615 
6616 static void skb_defer_free_flush(struct softnet_data *sd)
6617 {
6618 	struct sk_buff *skb, *next;
6619 	unsigned long flags;
6620 
6621 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6622 	if (!READ_ONCE(sd->defer_list))
6623 		return;
6624 
6625 	spin_lock_irqsave(&sd->defer_lock, flags);
6626 	skb = sd->defer_list;
6627 	sd->defer_list = NULL;
6628 	sd->defer_count = 0;
6629 	spin_unlock_irqrestore(&sd->defer_lock, flags);
6630 
6631 	while (skb != NULL) {
6632 		next = skb->next;
6633 		napi_consume_skb(skb, 1);
6634 		skb = next;
6635 	}
6636 }
6637 
6638 static __latent_entropy void net_rx_action(struct softirq_action *h)
6639 {
6640 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6641 	unsigned long time_limit = jiffies +
6642 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6643 	int budget = READ_ONCE(netdev_budget);
6644 	LIST_HEAD(list);
6645 	LIST_HEAD(repoll);
6646 
6647 	local_irq_disable();
6648 	list_splice_init(&sd->poll_list, &list);
6649 	local_irq_enable();
6650 
6651 	for (;;) {
6652 		struct napi_struct *n;
6653 
6654 		skb_defer_free_flush(sd);
6655 
6656 		if (list_empty(&list)) {
6657 			if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
6658 				goto end;
6659 			break;
6660 		}
6661 
6662 		n = list_first_entry(&list, struct napi_struct, poll_list);
6663 		budget -= napi_poll(n, &repoll);
6664 
6665 		/* If softirq window is exhausted then punt.
6666 		 * Allow this to run for 2 jiffies since which will allow
6667 		 * an average latency of 1.5/HZ.
6668 		 */
6669 		if (unlikely(budget <= 0 ||
6670 			     time_after_eq(jiffies, time_limit))) {
6671 			sd->time_squeeze++;
6672 			break;
6673 		}
6674 	}
6675 
6676 	local_irq_disable();
6677 
6678 	list_splice_tail_init(&sd->poll_list, &list);
6679 	list_splice_tail(&repoll, &list);
6680 	list_splice(&list, &sd->poll_list);
6681 	if (!list_empty(&sd->poll_list))
6682 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6683 
6684 	net_rps_action_and_irq_enable(sd);
6685 end:;
6686 }
6687 
6688 struct netdev_adjacent {
6689 	struct net_device *dev;
6690 	netdevice_tracker dev_tracker;
6691 
6692 	/* upper master flag, there can only be one master device per list */
6693 	bool master;
6694 
6695 	/* lookup ignore flag */
6696 	bool ignore;
6697 
6698 	/* counter for the number of times this device was added to us */
6699 	u16 ref_nr;
6700 
6701 	/* private field for the users */
6702 	void *private;
6703 
6704 	struct list_head list;
6705 	struct rcu_head rcu;
6706 };
6707 
6708 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6709 						 struct list_head *adj_list)
6710 {
6711 	struct netdev_adjacent *adj;
6712 
6713 	list_for_each_entry(adj, adj_list, list) {
6714 		if (adj->dev == adj_dev)
6715 			return adj;
6716 	}
6717 	return NULL;
6718 }
6719 
6720 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6721 				    struct netdev_nested_priv *priv)
6722 {
6723 	struct net_device *dev = (struct net_device *)priv->data;
6724 
6725 	return upper_dev == dev;
6726 }
6727 
6728 /**
6729  * netdev_has_upper_dev - Check if device is linked to an upper device
6730  * @dev: device
6731  * @upper_dev: upper device to check
6732  *
6733  * Find out if a device is linked to specified upper device and return true
6734  * in case it is. Note that this checks only immediate upper device,
6735  * not through a complete stack of devices. The caller must hold the RTNL lock.
6736  */
6737 bool netdev_has_upper_dev(struct net_device *dev,
6738 			  struct net_device *upper_dev)
6739 {
6740 	struct netdev_nested_priv priv = {
6741 		.data = (void *)upper_dev,
6742 	};
6743 
6744 	ASSERT_RTNL();
6745 
6746 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6747 					     &priv);
6748 }
6749 EXPORT_SYMBOL(netdev_has_upper_dev);
6750 
6751 /**
6752  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6753  * @dev: device
6754  * @upper_dev: upper device to check
6755  *
6756  * Find out if a device is linked to specified upper device and return true
6757  * in case it is. Note that this checks the entire upper device chain.
6758  * The caller must hold rcu lock.
6759  */
6760 
6761 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6762 				  struct net_device *upper_dev)
6763 {
6764 	struct netdev_nested_priv priv = {
6765 		.data = (void *)upper_dev,
6766 	};
6767 
6768 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6769 					       &priv);
6770 }
6771 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6772 
6773 /**
6774  * netdev_has_any_upper_dev - Check if device is linked to some device
6775  * @dev: device
6776  *
6777  * Find out if a device is linked to an upper device and return true in case
6778  * it is. The caller must hold the RTNL lock.
6779  */
6780 bool netdev_has_any_upper_dev(struct net_device *dev)
6781 {
6782 	ASSERT_RTNL();
6783 
6784 	return !list_empty(&dev->adj_list.upper);
6785 }
6786 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6787 
6788 /**
6789  * netdev_master_upper_dev_get - Get master upper device
6790  * @dev: device
6791  *
6792  * Find a master upper device and return pointer to it or NULL in case
6793  * it's not there. The caller must hold the RTNL lock.
6794  */
6795 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6796 {
6797 	struct netdev_adjacent *upper;
6798 
6799 	ASSERT_RTNL();
6800 
6801 	if (list_empty(&dev->adj_list.upper))
6802 		return NULL;
6803 
6804 	upper = list_first_entry(&dev->adj_list.upper,
6805 				 struct netdev_adjacent, list);
6806 	if (likely(upper->master))
6807 		return upper->dev;
6808 	return NULL;
6809 }
6810 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6811 
6812 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6813 {
6814 	struct netdev_adjacent *upper;
6815 
6816 	ASSERT_RTNL();
6817 
6818 	if (list_empty(&dev->adj_list.upper))
6819 		return NULL;
6820 
6821 	upper = list_first_entry(&dev->adj_list.upper,
6822 				 struct netdev_adjacent, list);
6823 	if (likely(upper->master) && !upper->ignore)
6824 		return upper->dev;
6825 	return NULL;
6826 }
6827 
6828 /**
6829  * netdev_has_any_lower_dev - Check if device is linked to some device
6830  * @dev: device
6831  *
6832  * Find out if a device is linked to a lower device and return true in case
6833  * it is. The caller must hold the RTNL lock.
6834  */
6835 static bool netdev_has_any_lower_dev(struct net_device *dev)
6836 {
6837 	ASSERT_RTNL();
6838 
6839 	return !list_empty(&dev->adj_list.lower);
6840 }
6841 
6842 void *netdev_adjacent_get_private(struct list_head *adj_list)
6843 {
6844 	struct netdev_adjacent *adj;
6845 
6846 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6847 
6848 	return adj->private;
6849 }
6850 EXPORT_SYMBOL(netdev_adjacent_get_private);
6851 
6852 /**
6853  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6854  * @dev: device
6855  * @iter: list_head ** of the current position
6856  *
6857  * Gets the next device from the dev's upper list, starting from iter
6858  * position. The caller must hold RCU read lock.
6859  */
6860 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6861 						 struct list_head **iter)
6862 {
6863 	struct netdev_adjacent *upper;
6864 
6865 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6866 
6867 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6868 
6869 	if (&upper->list == &dev->adj_list.upper)
6870 		return NULL;
6871 
6872 	*iter = &upper->list;
6873 
6874 	return upper->dev;
6875 }
6876 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6877 
6878 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6879 						  struct list_head **iter,
6880 						  bool *ignore)
6881 {
6882 	struct netdev_adjacent *upper;
6883 
6884 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6885 
6886 	if (&upper->list == &dev->adj_list.upper)
6887 		return NULL;
6888 
6889 	*iter = &upper->list;
6890 	*ignore = upper->ignore;
6891 
6892 	return upper->dev;
6893 }
6894 
6895 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6896 						    struct list_head **iter)
6897 {
6898 	struct netdev_adjacent *upper;
6899 
6900 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6901 
6902 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6903 
6904 	if (&upper->list == &dev->adj_list.upper)
6905 		return NULL;
6906 
6907 	*iter = &upper->list;
6908 
6909 	return upper->dev;
6910 }
6911 
6912 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6913 				       int (*fn)(struct net_device *dev,
6914 					 struct netdev_nested_priv *priv),
6915 				       struct netdev_nested_priv *priv)
6916 {
6917 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6918 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6919 	int ret, cur = 0;
6920 	bool ignore;
6921 
6922 	now = dev;
6923 	iter = &dev->adj_list.upper;
6924 
6925 	while (1) {
6926 		if (now != dev) {
6927 			ret = fn(now, priv);
6928 			if (ret)
6929 				return ret;
6930 		}
6931 
6932 		next = NULL;
6933 		while (1) {
6934 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
6935 			if (!udev)
6936 				break;
6937 			if (ignore)
6938 				continue;
6939 
6940 			next = udev;
6941 			niter = &udev->adj_list.upper;
6942 			dev_stack[cur] = now;
6943 			iter_stack[cur++] = iter;
6944 			break;
6945 		}
6946 
6947 		if (!next) {
6948 			if (!cur)
6949 				return 0;
6950 			next = dev_stack[--cur];
6951 			niter = iter_stack[cur];
6952 		}
6953 
6954 		now = next;
6955 		iter = niter;
6956 	}
6957 
6958 	return 0;
6959 }
6960 
6961 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6962 				  int (*fn)(struct net_device *dev,
6963 					    struct netdev_nested_priv *priv),
6964 				  struct netdev_nested_priv *priv)
6965 {
6966 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6967 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6968 	int ret, cur = 0;
6969 
6970 	now = dev;
6971 	iter = &dev->adj_list.upper;
6972 
6973 	while (1) {
6974 		if (now != dev) {
6975 			ret = fn(now, priv);
6976 			if (ret)
6977 				return ret;
6978 		}
6979 
6980 		next = NULL;
6981 		while (1) {
6982 			udev = netdev_next_upper_dev_rcu(now, &iter);
6983 			if (!udev)
6984 				break;
6985 
6986 			next = udev;
6987 			niter = &udev->adj_list.upper;
6988 			dev_stack[cur] = now;
6989 			iter_stack[cur++] = iter;
6990 			break;
6991 		}
6992 
6993 		if (!next) {
6994 			if (!cur)
6995 				return 0;
6996 			next = dev_stack[--cur];
6997 			niter = iter_stack[cur];
6998 		}
6999 
7000 		now = next;
7001 		iter = niter;
7002 	}
7003 
7004 	return 0;
7005 }
7006 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7007 
7008 static bool __netdev_has_upper_dev(struct net_device *dev,
7009 				   struct net_device *upper_dev)
7010 {
7011 	struct netdev_nested_priv priv = {
7012 		.flags = 0,
7013 		.data = (void *)upper_dev,
7014 	};
7015 
7016 	ASSERT_RTNL();
7017 
7018 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7019 					   &priv);
7020 }
7021 
7022 /**
7023  * netdev_lower_get_next_private - Get the next ->private from the
7024  *				   lower neighbour list
7025  * @dev: device
7026  * @iter: list_head ** of the current position
7027  *
7028  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7029  * list, starting from iter position. The caller must hold either hold the
7030  * RTNL lock or its own locking that guarantees that the neighbour lower
7031  * list will remain unchanged.
7032  */
7033 void *netdev_lower_get_next_private(struct net_device *dev,
7034 				    struct list_head **iter)
7035 {
7036 	struct netdev_adjacent *lower;
7037 
7038 	lower = list_entry(*iter, struct netdev_adjacent, list);
7039 
7040 	if (&lower->list == &dev->adj_list.lower)
7041 		return NULL;
7042 
7043 	*iter = lower->list.next;
7044 
7045 	return lower->private;
7046 }
7047 EXPORT_SYMBOL(netdev_lower_get_next_private);
7048 
7049 /**
7050  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7051  *				       lower neighbour list, RCU
7052  *				       variant
7053  * @dev: device
7054  * @iter: list_head ** of the current position
7055  *
7056  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7057  * list, starting from iter position. The caller must hold RCU read lock.
7058  */
7059 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7060 					struct list_head **iter)
7061 {
7062 	struct netdev_adjacent *lower;
7063 
7064 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7065 
7066 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7067 
7068 	if (&lower->list == &dev->adj_list.lower)
7069 		return NULL;
7070 
7071 	*iter = &lower->list;
7072 
7073 	return lower->private;
7074 }
7075 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7076 
7077 /**
7078  * netdev_lower_get_next - Get the next device from the lower neighbour
7079  *                         list
7080  * @dev: device
7081  * @iter: list_head ** of the current position
7082  *
7083  * Gets the next netdev_adjacent from the dev's lower neighbour
7084  * list, starting from iter position. The caller must hold RTNL lock or
7085  * its own locking that guarantees that the neighbour lower
7086  * list will remain unchanged.
7087  */
7088 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7089 {
7090 	struct netdev_adjacent *lower;
7091 
7092 	lower = list_entry(*iter, struct netdev_adjacent, list);
7093 
7094 	if (&lower->list == &dev->adj_list.lower)
7095 		return NULL;
7096 
7097 	*iter = lower->list.next;
7098 
7099 	return lower->dev;
7100 }
7101 EXPORT_SYMBOL(netdev_lower_get_next);
7102 
7103 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7104 						struct list_head **iter)
7105 {
7106 	struct netdev_adjacent *lower;
7107 
7108 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7109 
7110 	if (&lower->list == &dev->adj_list.lower)
7111 		return NULL;
7112 
7113 	*iter = &lower->list;
7114 
7115 	return lower->dev;
7116 }
7117 
7118 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7119 						  struct list_head **iter,
7120 						  bool *ignore)
7121 {
7122 	struct netdev_adjacent *lower;
7123 
7124 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7125 
7126 	if (&lower->list == &dev->adj_list.lower)
7127 		return NULL;
7128 
7129 	*iter = &lower->list;
7130 	*ignore = lower->ignore;
7131 
7132 	return lower->dev;
7133 }
7134 
7135 int netdev_walk_all_lower_dev(struct net_device *dev,
7136 			      int (*fn)(struct net_device *dev,
7137 					struct netdev_nested_priv *priv),
7138 			      struct netdev_nested_priv *priv)
7139 {
7140 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7141 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7142 	int ret, cur = 0;
7143 
7144 	now = dev;
7145 	iter = &dev->adj_list.lower;
7146 
7147 	while (1) {
7148 		if (now != dev) {
7149 			ret = fn(now, priv);
7150 			if (ret)
7151 				return ret;
7152 		}
7153 
7154 		next = NULL;
7155 		while (1) {
7156 			ldev = netdev_next_lower_dev(now, &iter);
7157 			if (!ldev)
7158 				break;
7159 
7160 			next = ldev;
7161 			niter = &ldev->adj_list.lower;
7162 			dev_stack[cur] = now;
7163 			iter_stack[cur++] = iter;
7164 			break;
7165 		}
7166 
7167 		if (!next) {
7168 			if (!cur)
7169 				return 0;
7170 			next = dev_stack[--cur];
7171 			niter = iter_stack[cur];
7172 		}
7173 
7174 		now = next;
7175 		iter = niter;
7176 	}
7177 
7178 	return 0;
7179 }
7180 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7181 
7182 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7183 				       int (*fn)(struct net_device *dev,
7184 					 struct netdev_nested_priv *priv),
7185 				       struct netdev_nested_priv *priv)
7186 {
7187 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7188 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7189 	int ret, cur = 0;
7190 	bool ignore;
7191 
7192 	now = dev;
7193 	iter = &dev->adj_list.lower;
7194 
7195 	while (1) {
7196 		if (now != dev) {
7197 			ret = fn(now, priv);
7198 			if (ret)
7199 				return ret;
7200 		}
7201 
7202 		next = NULL;
7203 		while (1) {
7204 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7205 			if (!ldev)
7206 				break;
7207 			if (ignore)
7208 				continue;
7209 
7210 			next = ldev;
7211 			niter = &ldev->adj_list.lower;
7212 			dev_stack[cur] = now;
7213 			iter_stack[cur++] = iter;
7214 			break;
7215 		}
7216 
7217 		if (!next) {
7218 			if (!cur)
7219 				return 0;
7220 			next = dev_stack[--cur];
7221 			niter = iter_stack[cur];
7222 		}
7223 
7224 		now = next;
7225 		iter = niter;
7226 	}
7227 
7228 	return 0;
7229 }
7230 
7231 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7232 					     struct list_head **iter)
7233 {
7234 	struct netdev_adjacent *lower;
7235 
7236 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7237 	if (&lower->list == &dev->adj_list.lower)
7238 		return NULL;
7239 
7240 	*iter = &lower->list;
7241 
7242 	return lower->dev;
7243 }
7244 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7245 
7246 static u8 __netdev_upper_depth(struct net_device *dev)
7247 {
7248 	struct net_device *udev;
7249 	struct list_head *iter;
7250 	u8 max_depth = 0;
7251 	bool ignore;
7252 
7253 	for (iter = &dev->adj_list.upper,
7254 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7255 	     udev;
7256 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7257 		if (ignore)
7258 			continue;
7259 		if (max_depth < udev->upper_level)
7260 			max_depth = udev->upper_level;
7261 	}
7262 
7263 	return max_depth;
7264 }
7265 
7266 static u8 __netdev_lower_depth(struct net_device *dev)
7267 {
7268 	struct net_device *ldev;
7269 	struct list_head *iter;
7270 	u8 max_depth = 0;
7271 	bool ignore;
7272 
7273 	for (iter = &dev->adj_list.lower,
7274 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7275 	     ldev;
7276 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7277 		if (ignore)
7278 			continue;
7279 		if (max_depth < ldev->lower_level)
7280 			max_depth = ldev->lower_level;
7281 	}
7282 
7283 	return max_depth;
7284 }
7285 
7286 static int __netdev_update_upper_level(struct net_device *dev,
7287 				       struct netdev_nested_priv *__unused)
7288 {
7289 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7290 	return 0;
7291 }
7292 
7293 #ifdef CONFIG_LOCKDEP
7294 static LIST_HEAD(net_unlink_list);
7295 
7296 static void net_unlink_todo(struct net_device *dev)
7297 {
7298 	if (list_empty(&dev->unlink_list))
7299 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7300 }
7301 #endif
7302 
7303 static int __netdev_update_lower_level(struct net_device *dev,
7304 				       struct netdev_nested_priv *priv)
7305 {
7306 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7307 
7308 #ifdef CONFIG_LOCKDEP
7309 	if (!priv)
7310 		return 0;
7311 
7312 	if (priv->flags & NESTED_SYNC_IMM)
7313 		dev->nested_level = dev->lower_level - 1;
7314 	if (priv->flags & NESTED_SYNC_TODO)
7315 		net_unlink_todo(dev);
7316 #endif
7317 	return 0;
7318 }
7319 
7320 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7321 				  int (*fn)(struct net_device *dev,
7322 					    struct netdev_nested_priv *priv),
7323 				  struct netdev_nested_priv *priv)
7324 {
7325 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7326 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7327 	int ret, cur = 0;
7328 
7329 	now = dev;
7330 	iter = &dev->adj_list.lower;
7331 
7332 	while (1) {
7333 		if (now != dev) {
7334 			ret = fn(now, priv);
7335 			if (ret)
7336 				return ret;
7337 		}
7338 
7339 		next = NULL;
7340 		while (1) {
7341 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7342 			if (!ldev)
7343 				break;
7344 
7345 			next = ldev;
7346 			niter = &ldev->adj_list.lower;
7347 			dev_stack[cur] = now;
7348 			iter_stack[cur++] = iter;
7349 			break;
7350 		}
7351 
7352 		if (!next) {
7353 			if (!cur)
7354 				return 0;
7355 			next = dev_stack[--cur];
7356 			niter = iter_stack[cur];
7357 		}
7358 
7359 		now = next;
7360 		iter = niter;
7361 	}
7362 
7363 	return 0;
7364 }
7365 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7366 
7367 /**
7368  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7369  *				       lower neighbour list, RCU
7370  *				       variant
7371  * @dev: device
7372  *
7373  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7374  * list. The caller must hold RCU read lock.
7375  */
7376 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7377 {
7378 	struct netdev_adjacent *lower;
7379 
7380 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7381 			struct netdev_adjacent, list);
7382 	if (lower)
7383 		return lower->private;
7384 	return NULL;
7385 }
7386 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7387 
7388 /**
7389  * netdev_master_upper_dev_get_rcu - Get master upper device
7390  * @dev: device
7391  *
7392  * Find a master upper device and return pointer to it or NULL in case
7393  * it's not there. The caller must hold the RCU read lock.
7394  */
7395 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7396 {
7397 	struct netdev_adjacent *upper;
7398 
7399 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7400 				       struct netdev_adjacent, list);
7401 	if (upper && likely(upper->master))
7402 		return upper->dev;
7403 	return NULL;
7404 }
7405 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7406 
7407 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7408 			      struct net_device *adj_dev,
7409 			      struct list_head *dev_list)
7410 {
7411 	char linkname[IFNAMSIZ+7];
7412 
7413 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7414 		"upper_%s" : "lower_%s", adj_dev->name);
7415 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7416 				 linkname);
7417 }
7418 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7419 			       char *name,
7420 			       struct list_head *dev_list)
7421 {
7422 	char linkname[IFNAMSIZ+7];
7423 
7424 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7425 		"upper_%s" : "lower_%s", name);
7426 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7427 }
7428 
7429 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7430 						 struct net_device *adj_dev,
7431 						 struct list_head *dev_list)
7432 {
7433 	return (dev_list == &dev->adj_list.upper ||
7434 		dev_list == &dev->adj_list.lower) &&
7435 		net_eq(dev_net(dev), dev_net(adj_dev));
7436 }
7437 
7438 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7439 					struct net_device *adj_dev,
7440 					struct list_head *dev_list,
7441 					void *private, bool master)
7442 {
7443 	struct netdev_adjacent *adj;
7444 	int ret;
7445 
7446 	adj = __netdev_find_adj(adj_dev, dev_list);
7447 
7448 	if (adj) {
7449 		adj->ref_nr += 1;
7450 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7451 			 dev->name, adj_dev->name, adj->ref_nr);
7452 
7453 		return 0;
7454 	}
7455 
7456 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7457 	if (!adj)
7458 		return -ENOMEM;
7459 
7460 	adj->dev = adj_dev;
7461 	adj->master = master;
7462 	adj->ref_nr = 1;
7463 	adj->private = private;
7464 	adj->ignore = false;
7465 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7466 
7467 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7468 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7469 
7470 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7471 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7472 		if (ret)
7473 			goto free_adj;
7474 	}
7475 
7476 	/* Ensure that master link is always the first item in list. */
7477 	if (master) {
7478 		ret = sysfs_create_link(&(dev->dev.kobj),
7479 					&(adj_dev->dev.kobj), "master");
7480 		if (ret)
7481 			goto remove_symlinks;
7482 
7483 		list_add_rcu(&adj->list, dev_list);
7484 	} else {
7485 		list_add_tail_rcu(&adj->list, dev_list);
7486 	}
7487 
7488 	return 0;
7489 
7490 remove_symlinks:
7491 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7492 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7493 free_adj:
7494 	netdev_put(adj_dev, &adj->dev_tracker);
7495 	kfree(adj);
7496 
7497 	return ret;
7498 }
7499 
7500 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7501 					 struct net_device *adj_dev,
7502 					 u16 ref_nr,
7503 					 struct list_head *dev_list)
7504 {
7505 	struct netdev_adjacent *adj;
7506 
7507 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7508 		 dev->name, adj_dev->name, ref_nr);
7509 
7510 	adj = __netdev_find_adj(adj_dev, dev_list);
7511 
7512 	if (!adj) {
7513 		pr_err("Adjacency does not exist for device %s from %s\n",
7514 		       dev->name, adj_dev->name);
7515 		WARN_ON(1);
7516 		return;
7517 	}
7518 
7519 	if (adj->ref_nr > ref_nr) {
7520 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7521 			 dev->name, adj_dev->name, ref_nr,
7522 			 adj->ref_nr - ref_nr);
7523 		adj->ref_nr -= ref_nr;
7524 		return;
7525 	}
7526 
7527 	if (adj->master)
7528 		sysfs_remove_link(&(dev->dev.kobj), "master");
7529 
7530 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7531 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7532 
7533 	list_del_rcu(&adj->list);
7534 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7535 		 adj_dev->name, dev->name, adj_dev->name);
7536 	netdev_put(adj_dev, &adj->dev_tracker);
7537 	kfree_rcu(adj, rcu);
7538 }
7539 
7540 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7541 					    struct net_device *upper_dev,
7542 					    struct list_head *up_list,
7543 					    struct list_head *down_list,
7544 					    void *private, bool master)
7545 {
7546 	int ret;
7547 
7548 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7549 					   private, master);
7550 	if (ret)
7551 		return ret;
7552 
7553 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7554 					   private, false);
7555 	if (ret) {
7556 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7557 		return ret;
7558 	}
7559 
7560 	return 0;
7561 }
7562 
7563 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7564 					       struct net_device *upper_dev,
7565 					       u16 ref_nr,
7566 					       struct list_head *up_list,
7567 					       struct list_head *down_list)
7568 {
7569 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7570 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7571 }
7572 
7573 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7574 						struct net_device *upper_dev,
7575 						void *private, bool master)
7576 {
7577 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7578 						&dev->adj_list.upper,
7579 						&upper_dev->adj_list.lower,
7580 						private, master);
7581 }
7582 
7583 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7584 						   struct net_device *upper_dev)
7585 {
7586 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7587 					   &dev->adj_list.upper,
7588 					   &upper_dev->adj_list.lower);
7589 }
7590 
7591 static int __netdev_upper_dev_link(struct net_device *dev,
7592 				   struct net_device *upper_dev, bool master,
7593 				   void *upper_priv, void *upper_info,
7594 				   struct netdev_nested_priv *priv,
7595 				   struct netlink_ext_ack *extack)
7596 {
7597 	struct netdev_notifier_changeupper_info changeupper_info = {
7598 		.info = {
7599 			.dev = dev,
7600 			.extack = extack,
7601 		},
7602 		.upper_dev = upper_dev,
7603 		.master = master,
7604 		.linking = true,
7605 		.upper_info = upper_info,
7606 	};
7607 	struct net_device *master_dev;
7608 	int ret = 0;
7609 
7610 	ASSERT_RTNL();
7611 
7612 	if (dev == upper_dev)
7613 		return -EBUSY;
7614 
7615 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7616 	if (__netdev_has_upper_dev(upper_dev, dev))
7617 		return -EBUSY;
7618 
7619 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7620 		return -EMLINK;
7621 
7622 	if (!master) {
7623 		if (__netdev_has_upper_dev(dev, upper_dev))
7624 			return -EEXIST;
7625 	} else {
7626 		master_dev = __netdev_master_upper_dev_get(dev);
7627 		if (master_dev)
7628 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7629 	}
7630 
7631 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7632 					    &changeupper_info.info);
7633 	ret = notifier_to_errno(ret);
7634 	if (ret)
7635 		return ret;
7636 
7637 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7638 						   master);
7639 	if (ret)
7640 		return ret;
7641 
7642 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7643 					    &changeupper_info.info);
7644 	ret = notifier_to_errno(ret);
7645 	if (ret)
7646 		goto rollback;
7647 
7648 	__netdev_update_upper_level(dev, NULL);
7649 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7650 
7651 	__netdev_update_lower_level(upper_dev, priv);
7652 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7653 				    priv);
7654 
7655 	return 0;
7656 
7657 rollback:
7658 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7659 
7660 	return ret;
7661 }
7662 
7663 /**
7664  * netdev_upper_dev_link - Add a link to the upper device
7665  * @dev: device
7666  * @upper_dev: new upper device
7667  * @extack: netlink extended ack
7668  *
7669  * Adds a link to device which is upper to this one. The caller must hold
7670  * the RTNL lock. On a failure a negative errno code is returned.
7671  * On success the reference counts are adjusted and the function
7672  * returns zero.
7673  */
7674 int netdev_upper_dev_link(struct net_device *dev,
7675 			  struct net_device *upper_dev,
7676 			  struct netlink_ext_ack *extack)
7677 {
7678 	struct netdev_nested_priv priv = {
7679 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7680 		.data = NULL,
7681 	};
7682 
7683 	return __netdev_upper_dev_link(dev, upper_dev, false,
7684 				       NULL, NULL, &priv, extack);
7685 }
7686 EXPORT_SYMBOL(netdev_upper_dev_link);
7687 
7688 /**
7689  * netdev_master_upper_dev_link - Add a master link to the upper device
7690  * @dev: device
7691  * @upper_dev: new upper device
7692  * @upper_priv: upper device private
7693  * @upper_info: upper info to be passed down via notifier
7694  * @extack: netlink extended ack
7695  *
7696  * Adds a link to device which is upper to this one. In this case, only
7697  * one master upper device can be linked, although other non-master devices
7698  * might be linked as well. The caller must hold the RTNL lock.
7699  * On a failure a negative errno code is returned. On success the reference
7700  * counts are adjusted and the function returns zero.
7701  */
7702 int netdev_master_upper_dev_link(struct net_device *dev,
7703 				 struct net_device *upper_dev,
7704 				 void *upper_priv, void *upper_info,
7705 				 struct netlink_ext_ack *extack)
7706 {
7707 	struct netdev_nested_priv priv = {
7708 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7709 		.data = NULL,
7710 	};
7711 
7712 	return __netdev_upper_dev_link(dev, upper_dev, true,
7713 				       upper_priv, upper_info, &priv, extack);
7714 }
7715 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7716 
7717 static void __netdev_upper_dev_unlink(struct net_device *dev,
7718 				      struct net_device *upper_dev,
7719 				      struct netdev_nested_priv *priv)
7720 {
7721 	struct netdev_notifier_changeupper_info changeupper_info = {
7722 		.info = {
7723 			.dev = dev,
7724 		},
7725 		.upper_dev = upper_dev,
7726 		.linking = false,
7727 	};
7728 
7729 	ASSERT_RTNL();
7730 
7731 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7732 
7733 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7734 				      &changeupper_info.info);
7735 
7736 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7737 
7738 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7739 				      &changeupper_info.info);
7740 
7741 	__netdev_update_upper_level(dev, NULL);
7742 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7743 
7744 	__netdev_update_lower_level(upper_dev, priv);
7745 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7746 				    priv);
7747 }
7748 
7749 /**
7750  * netdev_upper_dev_unlink - Removes a link to upper device
7751  * @dev: device
7752  * @upper_dev: new upper device
7753  *
7754  * Removes a link to device which is upper to this one. The caller must hold
7755  * the RTNL lock.
7756  */
7757 void netdev_upper_dev_unlink(struct net_device *dev,
7758 			     struct net_device *upper_dev)
7759 {
7760 	struct netdev_nested_priv priv = {
7761 		.flags = NESTED_SYNC_TODO,
7762 		.data = NULL,
7763 	};
7764 
7765 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7766 }
7767 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7768 
7769 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7770 				      struct net_device *lower_dev,
7771 				      bool val)
7772 {
7773 	struct netdev_adjacent *adj;
7774 
7775 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7776 	if (adj)
7777 		adj->ignore = val;
7778 
7779 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7780 	if (adj)
7781 		adj->ignore = val;
7782 }
7783 
7784 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7785 					struct net_device *lower_dev)
7786 {
7787 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7788 }
7789 
7790 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7791 				       struct net_device *lower_dev)
7792 {
7793 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7794 }
7795 
7796 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7797 				   struct net_device *new_dev,
7798 				   struct net_device *dev,
7799 				   struct netlink_ext_ack *extack)
7800 {
7801 	struct netdev_nested_priv priv = {
7802 		.flags = 0,
7803 		.data = NULL,
7804 	};
7805 	int err;
7806 
7807 	if (!new_dev)
7808 		return 0;
7809 
7810 	if (old_dev && new_dev != old_dev)
7811 		netdev_adjacent_dev_disable(dev, old_dev);
7812 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7813 				      extack);
7814 	if (err) {
7815 		if (old_dev && new_dev != old_dev)
7816 			netdev_adjacent_dev_enable(dev, old_dev);
7817 		return err;
7818 	}
7819 
7820 	return 0;
7821 }
7822 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7823 
7824 void netdev_adjacent_change_commit(struct net_device *old_dev,
7825 				   struct net_device *new_dev,
7826 				   struct net_device *dev)
7827 {
7828 	struct netdev_nested_priv priv = {
7829 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7830 		.data = NULL,
7831 	};
7832 
7833 	if (!new_dev || !old_dev)
7834 		return;
7835 
7836 	if (new_dev == old_dev)
7837 		return;
7838 
7839 	netdev_adjacent_dev_enable(dev, old_dev);
7840 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7841 }
7842 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7843 
7844 void netdev_adjacent_change_abort(struct net_device *old_dev,
7845 				  struct net_device *new_dev,
7846 				  struct net_device *dev)
7847 {
7848 	struct netdev_nested_priv priv = {
7849 		.flags = 0,
7850 		.data = NULL,
7851 	};
7852 
7853 	if (!new_dev)
7854 		return;
7855 
7856 	if (old_dev && new_dev != old_dev)
7857 		netdev_adjacent_dev_enable(dev, old_dev);
7858 
7859 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7860 }
7861 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7862 
7863 /**
7864  * netdev_bonding_info_change - Dispatch event about slave change
7865  * @dev: device
7866  * @bonding_info: info to dispatch
7867  *
7868  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7869  * The caller must hold the RTNL lock.
7870  */
7871 void netdev_bonding_info_change(struct net_device *dev,
7872 				struct netdev_bonding_info *bonding_info)
7873 {
7874 	struct netdev_notifier_bonding_info info = {
7875 		.info.dev = dev,
7876 	};
7877 
7878 	memcpy(&info.bonding_info, bonding_info,
7879 	       sizeof(struct netdev_bonding_info));
7880 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7881 				      &info.info);
7882 }
7883 EXPORT_SYMBOL(netdev_bonding_info_change);
7884 
7885 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7886 					   struct netlink_ext_ack *extack)
7887 {
7888 	struct netdev_notifier_offload_xstats_info info = {
7889 		.info.dev = dev,
7890 		.info.extack = extack,
7891 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7892 	};
7893 	int err;
7894 	int rc;
7895 
7896 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7897 					 GFP_KERNEL);
7898 	if (!dev->offload_xstats_l3)
7899 		return -ENOMEM;
7900 
7901 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7902 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7903 						  &info.info);
7904 	err = notifier_to_errno(rc);
7905 	if (err)
7906 		goto free_stats;
7907 
7908 	return 0;
7909 
7910 free_stats:
7911 	kfree(dev->offload_xstats_l3);
7912 	dev->offload_xstats_l3 = NULL;
7913 	return err;
7914 }
7915 
7916 int netdev_offload_xstats_enable(struct net_device *dev,
7917 				 enum netdev_offload_xstats_type type,
7918 				 struct netlink_ext_ack *extack)
7919 {
7920 	ASSERT_RTNL();
7921 
7922 	if (netdev_offload_xstats_enabled(dev, type))
7923 		return -EALREADY;
7924 
7925 	switch (type) {
7926 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7927 		return netdev_offload_xstats_enable_l3(dev, extack);
7928 	}
7929 
7930 	WARN_ON(1);
7931 	return -EINVAL;
7932 }
7933 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7934 
7935 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7936 {
7937 	struct netdev_notifier_offload_xstats_info info = {
7938 		.info.dev = dev,
7939 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7940 	};
7941 
7942 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7943 				      &info.info);
7944 	kfree(dev->offload_xstats_l3);
7945 	dev->offload_xstats_l3 = NULL;
7946 }
7947 
7948 int netdev_offload_xstats_disable(struct net_device *dev,
7949 				  enum netdev_offload_xstats_type type)
7950 {
7951 	ASSERT_RTNL();
7952 
7953 	if (!netdev_offload_xstats_enabled(dev, type))
7954 		return -EALREADY;
7955 
7956 	switch (type) {
7957 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7958 		netdev_offload_xstats_disable_l3(dev);
7959 		return 0;
7960 	}
7961 
7962 	WARN_ON(1);
7963 	return -EINVAL;
7964 }
7965 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7966 
7967 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7968 {
7969 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7970 }
7971 
7972 static struct rtnl_hw_stats64 *
7973 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7974 			      enum netdev_offload_xstats_type type)
7975 {
7976 	switch (type) {
7977 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7978 		return dev->offload_xstats_l3;
7979 	}
7980 
7981 	WARN_ON(1);
7982 	return NULL;
7983 }
7984 
7985 bool netdev_offload_xstats_enabled(const struct net_device *dev,
7986 				   enum netdev_offload_xstats_type type)
7987 {
7988 	ASSERT_RTNL();
7989 
7990 	return netdev_offload_xstats_get_ptr(dev, type);
7991 }
7992 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
7993 
7994 struct netdev_notifier_offload_xstats_ru {
7995 	bool used;
7996 };
7997 
7998 struct netdev_notifier_offload_xstats_rd {
7999 	struct rtnl_hw_stats64 stats;
8000 	bool used;
8001 };
8002 
8003 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8004 				  const struct rtnl_hw_stats64 *src)
8005 {
8006 	dest->rx_packets	  += src->rx_packets;
8007 	dest->tx_packets	  += src->tx_packets;
8008 	dest->rx_bytes		  += src->rx_bytes;
8009 	dest->tx_bytes		  += src->tx_bytes;
8010 	dest->rx_errors		  += src->rx_errors;
8011 	dest->tx_errors		  += src->tx_errors;
8012 	dest->rx_dropped	  += src->rx_dropped;
8013 	dest->tx_dropped	  += src->tx_dropped;
8014 	dest->multicast		  += src->multicast;
8015 }
8016 
8017 static int netdev_offload_xstats_get_used(struct net_device *dev,
8018 					  enum netdev_offload_xstats_type type,
8019 					  bool *p_used,
8020 					  struct netlink_ext_ack *extack)
8021 {
8022 	struct netdev_notifier_offload_xstats_ru report_used = {};
8023 	struct netdev_notifier_offload_xstats_info info = {
8024 		.info.dev = dev,
8025 		.info.extack = extack,
8026 		.type = type,
8027 		.report_used = &report_used,
8028 	};
8029 	int rc;
8030 
8031 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8032 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8033 					   &info.info);
8034 	*p_used = report_used.used;
8035 	return notifier_to_errno(rc);
8036 }
8037 
8038 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8039 					   enum netdev_offload_xstats_type type,
8040 					   struct rtnl_hw_stats64 *p_stats,
8041 					   bool *p_used,
8042 					   struct netlink_ext_ack *extack)
8043 {
8044 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8045 	struct netdev_notifier_offload_xstats_info info = {
8046 		.info.dev = dev,
8047 		.info.extack = extack,
8048 		.type = type,
8049 		.report_delta = &report_delta,
8050 	};
8051 	struct rtnl_hw_stats64 *stats;
8052 	int rc;
8053 
8054 	stats = netdev_offload_xstats_get_ptr(dev, type);
8055 	if (WARN_ON(!stats))
8056 		return -EINVAL;
8057 
8058 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8059 					   &info.info);
8060 
8061 	/* Cache whatever we got, even if there was an error, otherwise the
8062 	 * successful stats retrievals would get lost.
8063 	 */
8064 	netdev_hw_stats64_add(stats, &report_delta.stats);
8065 
8066 	if (p_stats)
8067 		*p_stats = *stats;
8068 	*p_used = report_delta.used;
8069 
8070 	return notifier_to_errno(rc);
8071 }
8072 
8073 int netdev_offload_xstats_get(struct net_device *dev,
8074 			      enum netdev_offload_xstats_type type,
8075 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8076 			      struct netlink_ext_ack *extack)
8077 {
8078 	ASSERT_RTNL();
8079 
8080 	if (p_stats)
8081 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8082 						       p_used, extack);
8083 	else
8084 		return netdev_offload_xstats_get_used(dev, type, p_used,
8085 						      extack);
8086 }
8087 EXPORT_SYMBOL(netdev_offload_xstats_get);
8088 
8089 void
8090 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8091 				   const struct rtnl_hw_stats64 *stats)
8092 {
8093 	report_delta->used = true;
8094 	netdev_hw_stats64_add(&report_delta->stats, stats);
8095 }
8096 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8097 
8098 void
8099 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8100 {
8101 	report_used->used = true;
8102 }
8103 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8104 
8105 void netdev_offload_xstats_push_delta(struct net_device *dev,
8106 				      enum netdev_offload_xstats_type type,
8107 				      const struct rtnl_hw_stats64 *p_stats)
8108 {
8109 	struct rtnl_hw_stats64 *stats;
8110 
8111 	ASSERT_RTNL();
8112 
8113 	stats = netdev_offload_xstats_get_ptr(dev, type);
8114 	if (WARN_ON(!stats))
8115 		return;
8116 
8117 	netdev_hw_stats64_add(stats, p_stats);
8118 }
8119 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8120 
8121 /**
8122  * netdev_get_xmit_slave - Get the xmit slave of master device
8123  * @dev: device
8124  * @skb: The packet
8125  * @all_slaves: assume all the slaves are active
8126  *
8127  * The reference counters are not incremented so the caller must be
8128  * careful with locks. The caller must hold RCU lock.
8129  * %NULL is returned if no slave is found.
8130  */
8131 
8132 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8133 					 struct sk_buff *skb,
8134 					 bool all_slaves)
8135 {
8136 	const struct net_device_ops *ops = dev->netdev_ops;
8137 
8138 	if (!ops->ndo_get_xmit_slave)
8139 		return NULL;
8140 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8141 }
8142 EXPORT_SYMBOL(netdev_get_xmit_slave);
8143 
8144 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8145 						  struct sock *sk)
8146 {
8147 	const struct net_device_ops *ops = dev->netdev_ops;
8148 
8149 	if (!ops->ndo_sk_get_lower_dev)
8150 		return NULL;
8151 	return ops->ndo_sk_get_lower_dev(dev, sk);
8152 }
8153 
8154 /**
8155  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8156  * @dev: device
8157  * @sk: the socket
8158  *
8159  * %NULL is returned if no lower device is found.
8160  */
8161 
8162 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8163 					    struct sock *sk)
8164 {
8165 	struct net_device *lower;
8166 
8167 	lower = netdev_sk_get_lower_dev(dev, sk);
8168 	while (lower) {
8169 		dev = lower;
8170 		lower = netdev_sk_get_lower_dev(dev, sk);
8171 	}
8172 
8173 	return dev;
8174 }
8175 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8176 
8177 static void netdev_adjacent_add_links(struct net_device *dev)
8178 {
8179 	struct netdev_adjacent *iter;
8180 
8181 	struct net *net = dev_net(dev);
8182 
8183 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8184 		if (!net_eq(net, dev_net(iter->dev)))
8185 			continue;
8186 		netdev_adjacent_sysfs_add(iter->dev, dev,
8187 					  &iter->dev->adj_list.lower);
8188 		netdev_adjacent_sysfs_add(dev, iter->dev,
8189 					  &dev->adj_list.upper);
8190 	}
8191 
8192 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8193 		if (!net_eq(net, dev_net(iter->dev)))
8194 			continue;
8195 		netdev_adjacent_sysfs_add(iter->dev, dev,
8196 					  &iter->dev->adj_list.upper);
8197 		netdev_adjacent_sysfs_add(dev, iter->dev,
8198 					  &dev->adj_list.lower);
8199 	}
8200 }
8201 
8202 static void netdev_adjacent_del_links(struct net_device *dev)
8203 {
8204 	struct netdev_adjacent *iter;
8205 
8206 	struct net *net = dev_net(dev);
8207 
8208 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8209 		if (!net_eq(net, dev_net(iter->dev)))
8210 			continue;
8211 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8212 					  &iter->dev->adj_list.lower);
8213 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8214 					  &dev->adj_list.upper);
8215 	}
8216 
8217 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8218 		if (!net_eq(net, dev_net(iter->dev)))
8219 			continue;
8220 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8221 					  &iter->dev->adj_list.upper);
8222 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8223 					  &dev->adj_list.lower);
8224 	}
8225 }
8226 
8227 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8228 {
8229 	struct netdev_adjacent *iter;
8230 
8231 	struct net *net = dev_net(dev);
8232 
8233 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8234 		if (!net_eq(net, dev_net(iter->dev)))
8235 			continue;
8236 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8237 					  &iter->dev->adj_list.lower);
8238 		netdev_adjacent_sysfs_add(iter->dev, dev,
8239 					  &iter->dev->adj_list.lower);
8240 	}
8241 
8242 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8243 		if (!net_eq(net, dev_net(iter->dev)))
8244 			continue;
8245 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8246 					  &iter->dev->adj_list.upper);
8247 		netdev_adjacent_sysfs_add(iter->dev, dev,
8248 					  &iter->dev->adj_list.upper);
8249 	}
8250 }
8251 
8252 void *netdev_lower_dev_get_private(struct net_device *dev,
8253 				   struct net_device *lower_dev)
8254 {
8255 	struct netdev_adjacent *lower;
8256 
8257 	if (!lower_dev)
8258 		return NULL;
8259 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8260 	if (!lower)
8261 		return NULL;
8262 
8263 	return lower->private;
8264 }
8265 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8266 
8267 
8268 /**
8269  * netdev_lower_state_changed - Dispatch event about lower device state change
8270  * @lower_dev: device
8271  * @lower_state_info: state to dispatch
8272  *
8273  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8274  * The caller must hold the RTNL lock.
8275  */
8276 void netdev_lower_state_changed(struct net_device *lower_dev,
8277 				void *lower_state_info)
8278 {
8279 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8280 		.info.dev = lower_dev,
8281 	};
8282 
8283 	ASSERT_RTNL();
8284 	changelowerstate_info.lower_state_info = lower_state_info;
8285 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8286 				      &changelowerstate_info.info);
8287 }
8288 EXPORT_SYMBOL(netdev_lower_state_changed);
8289 
8290 static void dev_change_rx_flags(struct net_device *dev, int flags)
8291 {
8292 	const struct net_device_ops *ops = dev->netdev_ops;
8293 
8294 	if (ops->ndo_change_rx_flags)
8295 		ops->ndo_change_rx_flags(dev, flags);
8296 }
8297 
8298 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8299 {
8300 	unsigned int old_flags = dev->flags;
8301 	kuid_t uid;
8302 	kgid_t gid;
8303 
8304 	ASSERT_RTNL();
8305 
8306 	dev->flags |= IFF_PROMISC;
8307 	dev->promiscuity += inc;
8308 	if (dev->promiscuity == 0) {
8309 		/*
8310 		 * Avoid overflow.
8311 		 * If inc causes overflow, untouch promisc and return error.
8312 		 */
8313 		if (inc < 0)
8314 			dev->flags &= ~IFF_PROMISC;
8315 		else {
8316 			dev->promiscuity -= inc;
8317 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8318 			return -EOVERFLOW;
8319 		}
8320 	}
8321 	if (dev->flags != old_flags) {
8322 		pr_info("device %s %s promiscuous mode\n",
8323 			dev->name,
8324 			dev->flags & IFF_PROMISC ? "entered" : "left");
8325 		if (audit_enabled) {
8326 			current_uid_gid(&uid, &gid);
8327 			audit_log(audit_context(), GFP_ATOMIC,
8328 				  AUDIT_ANOM_PROMISCUOUS,
8329 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8330 				  dev->name, (dev->flags & IFF_PROMISC),
8331 				  (old_flags & IFF_PROMISC),
8332 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8333 				  from_kuid(&init_user_ns, uid),
8334 				  from_kgid(&init_user_ns, gid),
8335 				  audit_get_sessionid(current));
8336 		}
8337 
8338 		dev_change_rx_flags(dev, IFF_PROMISC);
8339 	}
8340 	if (notify)
8341 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8342 	return 0;
8343 }
8344 
8345 /**
8346  *	dev_set_promiscuity	- update promiscuity count on a device
8347  *	@dev: device
8348  *	@inc: modifier
8349  *
8350  *	Add or remove promiscuity from a device. While the count in the device
8351  *	remains above zero the interface remains promiscuous. Once it hits zero
8352  *	the device reverts back to normal filtering operation. A negative inc
8353  *	value is used to drop promiscuity on the device.
8354  *	Return 0 if successful or a negative errno code on error.
8355  */
8356 int dev_set_promiscuity(struct net_device *dev, int inc)
8357 {
8358 	unsigned int old_flags = dev->flags;
8359 	int err;
8360 
8361 	err = __dev_set_promiscuity(dev, inc, true);
8362 	if (err < 0)
8363 		return err;
8364 	if (dev->flags != old_flags)
8365 		dev_set_rx_mode(dev);
8366 	return err;
8367 }
8368 EXPORT_SYMBOL(dev_set_promiscuity);
8369 
8370 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8371 {
8372 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8373 
8374 	ASSERT_RTNL();
8375 
8376 	dev->flags |= IFF_ALLMULTI;
8377 	dev->allmulti += inc;
8378 	if (dev->allmulti == 0) {
8379 		/*
8380 		 * Avoid overflow.
8381 		 * If inc causes overflow, untouch allmulti and return error.
8382 		 */
8383 		if (inc < 0)
8384 			dev->flags &= ~IFF_ALLMULTI;
8385 		else {
8386 			dev->allmulti -= inc;
8387 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8388 			return -EOVERFLOW;
8389 		}
8390 	}
8391 	if (dev->flags ^ old_flags) {
8392 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8393 		dev_set_rx_mode(dev);
8394 		if (notify)
8395 			__dev_notify_flags(dev, old_flags,
8396 					   dev->gflags ^ old_gflags, 0, NULL);
8397 	}
8398 	return 0;
8399 }
8400 
8401 /**
8402  *	dev_set_allmulti	- update allmulti count on a device
8403  *	@dev: device
8404  *	@inc: modifier
8405  *
8406  *	Add or remove reception of all multicast frames to a device. While the
8407  *	count in the device remains above zero the interface remains listening
8408  *	to all interfaces. Once it hits zero the device reverts back to normal
8409  *	filtering operation. A negative @inc value is used to drop the counter
8410  *	when releasing a resource needing all multicasts.
8411  *	Return 0 if successful or a negative errno code on error.
8412  */
8413 
8414 int dev_set_allmulti(struct net_device *dev, int inc)
8415 {
8416 	return __dev_set_allmulti(dev, inc, true);
8417 }
8418 EXPORT_SYMBOL(dev_set_allmulti);
8419 
8420 /*
8421  *	Upload unicast and multicast address lists to device and
8422  *	configure RX filtering. When the device doesn't support unicast
8423  *	filtering it is put in promiscuous mode while unicast addresses
8424  *	are present.
8425  */
8426 void __dev_set_rx_mode(struct net_device *dev)
8427 {
8428 	const struct net_device_ops *ops = dev->netdev_ops;
8429 
8430 	/* dev_open will call this function so the list will stay sane. */
8431 	if (!(dev->flags&IFF_UP))
8432 		return;
8433 
8434 	if (!netif_device_present(dev))
8435 		return;
8436 
8437 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8438 		/* Unicast addresses changes may only happen under the rtnl,
8439 		 * therefore calling __dev_set_promiscuity here is safe.
8440 		 */
8441 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8442 			__dev_set_promiscuity(dev, 1, false);
8443 			dev->uc_promisc = true;
8444 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8445 			__dev_set_promiscuity(dev, -1, false);
8446 			dev->uc_promisc = false;
8447 		}
8448 	}
8449 
8450 	if (ops->ndo_set_rx_mode)
8451 		ops->ndo_set_rx_mode(dev);
8452 }
8453 
8454 void dev_set_rx_mode(struct net_device *dev)
8455 {
8456 	netif_addr_lock_bh(dev);
8457 	__dev_set_rx_mode(dev);
8458 	netif_addr_unlock_bh(dev);
8459 }
8460 
8461 /**
8462  *	dev_get_flags - get flags reported to userspace
8463  *	@dev: device
8464  *
8465  *	Get the combination of flag bits exported through APIs to userspace.
8466  */
8467 unsigned int dev_get_flags(const struct net_device *dev)
8468 {
8469 	unsigned int flags;
8470 
8471 	flags = (dev->flags & ~(IFF_PROMISC |
8472 				IFF_ALLMULTI |
8473 				IFF_RUNNING |
8474 				IFF_LOWER_UP |
8475 				IFF_DORMANT)) |
8476 		(dev->gflags & (IFF_PROMISC |
8477 				IFF_ALLMULTI));
8478 
8479 	if (netif_running(dev)) {
8480 		if (netif_oper_up(dev))
8481 			flags |= IFF_RUNNING;
8482 		if (netif_carrier_ok(dev))
8483 			flags |= IFF_LOWER_UP;
8484 		if (netif_dormant(dev))
8485 			flags |= IFF_DORMANT;
8486 	}
8487 
8488 	return flags;
8489 }
8490 EXPORT_SYMBOL(dev_get_flags);
8491 
8492 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8493 		       struct netlink_ext_ack *extack)
8494 {
8495 	unsigned int old_flags = dev->flags;
8496 	int ret;
8497 
8498 	ASSERT_RTNL();
8499 
8500 	/*
8501 	 *	Set the flags on our device.
8502 	 */
8503 
8504 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8505 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8506 			       IFF_AUTOMEDIA)) |
8507 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8508 				    IFF_ALLMULTI));
8509 
8510 	/*
8511 	 *	Load in the correct multicast list now the flags have changed.
8512 	 */
8513 
8514 	if ((old_flags ^ flags) & IFF_MULTICAST)
8515 		dev_change_rx_flags(dev, IFF_MULTICAST);
8516 
8517 	dev_set_rx_mode(dev);
8518 
8519 	/*
8520 	 *	Have we downed the interface. We handle IFF_UP ourselves
8521 	 *	according to user attempts to set it, rather than blindly
8522 	 *	setting it.
8523 	 */
8524 
8525 	ret = 0;
8526 	if ((old_flags ^ flags) & IFF_UP) {
8527 		if (old_flags & IFF_UP)
8528 			__dev_close(dev);
8529 		else
8530 			ret = __dev_open(dev, extack);
8531 	}
8532 
8533 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8534 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8535 		unsigned int old_flags = dev->flags;
8536 
8537 		dev->gflags ^= IFF_PROMISC;
8538 
8539 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8540 			if (dev->flags != old_flags)
8541 				dev_set_rx_mode(dev);
8542 	}
8543 
8544 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8545 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8546 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8547 	 */
8548 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8549 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8550 
8551 		dev->gflags ^= IFF_ALLMULTI;
8552 		__dev_set_allmulti(dev, inc, false);
8553 	}
8554 
8555 	return ret;
8556 }
8557 
8558 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8559 			unsigned int gchanges, u32 portid,
8560 			const struct nlmsghdr *nlh)
8561 {
8562 	unsigned int changes = dev->flags ^ old_flags;
8563 
8564 	if (gchanges)
8565 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8566 
8567 	if (changes & IFF_UP) {
8568 		if (dev->flags & IFF_UP)
8569 			call_netdevice_notifiers(NETDEV_UP, dev);
8570 		else
8571 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8572 	}
8573 
8574 	if (dev->flags & IFF_UP &&
8575 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8576 		struct netdev_notifier_change_info change_info = {
8577 			.info = {
8578 				.dev = dev,
8579 			},
8580 			.flags_changed = changes,
8581 		};
8582 
8583 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8584 	}
8585 }
8586 
8587 /**
8588  *	dev_change_flags - change device settings
8589  *	@dev: device
8590  *	@flags: device state flags
8591  *	@extack: netlink extended ack
8592  *
8593  *	Change settings on device based state flags. The flags are
8594  *	in the userspace exported format.
8595  */
8596 int dev_change_flags(struct net_device *dev, unsigned int flags,
8597 		     struct netlink_ext_ack *extack)
8598 {
8599 	int ret;
8600 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8601 
8602 	ret = __dev_change_flags(dev, flags, extack);
8603 	if (ret < 0)
8604 		return ret;
8605 
8606 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8607 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8608 	return ret;
8609 }
8610 EXPORT_SYMBOL(dev_change_flags);
8611 
8612 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8613 {
8614 	const struct net_device_ops *ops = dev->netdev_ops;
8615 
8616 	if (ops->ndo_change_mtu)
8617 		return ops->ndo_change_mtu(dev, new_mtu);
8618 
8619 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8620 	WRITE_ONCE(dev->mtu, new_mtu);
8621 	return 0;
8622 }
8623 EXPORT_SYMBOL(__dev_set_mtu);
8624 
8625 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8626 		     struct netlink_ext_ack *extack)
8627 {
8628 	/* MTU must be positive, and in range */
8629 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8630 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8631 		return -EINVAL;
8632 	}
8633 
8634 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8635 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8636 		return -EINVAL;
8637 	}
8638 	return 0;
8639 }
8640 
8641 /**
8642  *	dev_set_mtu_ext - Change maximum transfer unit
8643  *	@dev: device
8644  *	@new_mtu: new transfer unit
8645  *	@extack: netlink extended ack
8646  *
8647  *	Change the maximum transfer size of the network device.
8648  */
8649 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8650 		    struct netlink_ext_ack *extack)
8651 {
8652 	int err, orig_mtu;
8653 
8654 	if (new_mtu == dev->mtu)
8655 		return 0;
8656 
8657 	err = dev_validate_mtu(dev, new_mtu, extack);
8658 	if (err)
8659 		return err;
8660 
8661 	if (!netif_device_present(dev))
8662 		return -ENODEV;
8663 
8664 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8665 	err = notifier_to_errno(err);
8666 	if (err)
8667 		return err;
8668 
8669 	orig_mtu = dev->mtu;
8670 	err = __dev_set_mtu(dev, new_mtu);
8671 
8672 	if (!err) {
8673 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8674 						   orig_mtu);
8675 		err = notifier_to_errno(err);
8676 		if (err) {
8677 			/* setting mtu back and notifying everyone again,
8678 			 * so that they have a chance to revert changes.
8679 			 */
8680 			__dev_set_mtu(dev, orig_mtu);
8681 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8682 						     new_mtu);
8683 		}
8684 	}
8685 	return err;
8686 }
8687 
8688 int dev_set_mtu(struct net_device *dev, int new_mtu)
8689 {
8690 	struct netlink_ext_ack extack;
8691 	int err;
8692 
8693 	memset(&extack, 0, sizeof(extack));
8694 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8695 	if (err && extack._msg)
8696 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8697 	return err;
8698 }
8699 EXPORT_SYMBOL(dev_set_mtu);
8700 
8701 /**
8702  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8703  *	@dev: device
8704  *	@new_len: new tx queue length
8705  */
8706 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8707 {
8708 	unsigned int orig_len = dev->tx_queue_len;
8709 	int res;
8710 
8711 	if (new_len != (unsigned int)new_len)
8712 		return -ERANGE;
8713 
8714 	if (new_len != orig_len) {
8715 		dev->tx_queue_len = new_len;
8716 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8717 		res = notifier_to_errno(res);
8718 		if (res)
8719 			goto err_rollback;
8720 		res = dev_qdisc_change_tx_queue_len(dev);
8721 		if (res)
8722 			goto err_rollback;
8723 	}
8724 
8725 	return 0;
8726 
8727 err_rollback:
8728 	netdev_err(dev, "refused to change device tx_queue_len\n");
8729 	dev->tx_queue_len = orig_len;
8730 	return res;
8731 }
8732 
8733 /**
8734  *	dev_set_group - Change group this device belongs to
8735  *	@dev: device
8736  *	@new_group: group this device should belong to
8737  */
8738 void dev_set_group(struct net_device *dev, int new_group)
8739 {
8740 	dev->group = new_group;
8741 }
8742 
8743 /**
8744  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8745  *	@dev: device
8746  *	@addr: new address
8747  *	@extack: netlink extended ack
8748  */
8749 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8750 			      struct netlink_ext_ack *extack)
8751 {
8752 	struct netdev_notifier_pre_changeaddr_info info = {
8753 		.info.dev = dev,
8754 		.info.extack = extack,
8755 		.dev_addr = addr,
8756 	};
8757 	int rc;
8758 
8759 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8760 	return notifier_to_errno(rc);
8761 }
8762 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8763 
8764 /**
8765  *	dev_set_mac_address - Change Media Access Control Address
8766  *	@dev: device
8767  *	@sa: new address
8768  *	@extack: netlink extended ack
8769  *
8770  *	Change the hardware (MAC) address of the device
8771  */
8772 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8773 			struct netlink_ext_ack *extack)
8774 {
8775 	const struct net_device_ops *ops = dev->netdev_ops;
8776 	int err;
8777 
8778 	if (!ops->ndo_set_mac_address)
8779 		return -EOPNOTSUPP;
8780 	if (sa->sa_family != dev->type)
8781 		return -EINVAL;
8782 	if (!netif_device_present(dev))
8783 		return -ENODEV;
8784 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8785 	if (err)
8786 		return err;
8787 	err = ops->ndo_set_mac_address(dev, sa);
8788 	if (err)
8789 		return err;
8790 	dev->addr_assign_type = NET_ADDR_SET;
8791 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8792 	add_device_randomness(dev->dev_addr, dev->addr_len);
8793 	return 0;
8794 }
8795 EXPORT_SYMBOL(dev_set_mac_address);
8796 
8797 static DECLARE_RWSEM(dev_addr_sem);
8798 
8799 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8800 			     struct netlink_ext_ack *extack)
8801 {
8802 	int ret;
8803 
8804 	down_write(&dev_addr_sem);
8805 	ret = dev_set_mac_address(dev, sa, extack);
8806 	up_write(&dev_addr_sem);
8807 	return ret;
8808 }
8809 EXPORT_SYMBOL(dev_set_mac_address_user);
8810 
8811 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8812 {
8813 	size_t size = sizeof(sa->sa_data_min);
8814 	struct net_device *dev;
8815 	int ret = 0;
8816 
8817 	down_read(&dev_addr_sem);
8818 	rcu_read_lock();
8819 
8820 	dev = dev_get_by_name_rcu(net, dev_name);
8821 	if (!dev) {
8822 		ret = -ENODEV;
8823 		goto unlock;
8824 	}
8825 	if (!dev->addr_len)
8826 		memset(sa->sa_data, 0, size);
8827 	else
8828 		memcpy(sa->sa_data, dev->dev_addr,
8829 		       min_t(size_t, size, dev->addr_len));
8830 	sa->sa_family = dev->type;
8831 
8832 unlock:
8833 	rcu_read_unlock();
8834 	up_read(&dev_addr_sem);
8835 	return ret;
8836 }
8837 EXPORT_SYMBOL(dev_get_mac_address);
8838 
8839 /**
8840  *	dev_change_carrier - Change device carrier
8841  *	@dev: device
8842  *	@new_carrier: new value
8843  *
8844  *	Change device carrier
8845  */
8846 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8847 {
8848 	const struct net_device_ops *ops = dev->netdev_ops;
8849 
8850 	if (!ops->ndo_change_carrier)
8851 		return -EOPNOTSUPP;
8852 	if (!netif_device_present(dev))
8853 		return -ENODEV;
8854 	return ops->ndo_change_carrier(dev, new_carrier);
8855 }
8856 
8857 /**
8858  *	dev_get_phys_port_id - Get device physical port ID
8859  *	@dev: device
8860  *	@ppid: port ID
8861  *
8862  *	Get device physical port ID
8863  */
8864 int dev_get_phys_port_id(struct net_device *dev,
8865 			 struct netdev_phys_item_id *ppid)
8866 {
8867 	const struct net_device_ops *ops = dev->netdev_ops;
8868 
8869 	if (!ops->ndo_get_phys_port_id)
8870 		return -EOPNOTSUPP;
8871 	return ops->ndo_get_phys_port_id(dev, ppid);
8872 }
8873 
8874 /**
8875  *	dev_get_phys_port_name - Get device physical port name
8876  *	@dev: device
8877  *	@name: port name
8878  *	@len: limit of bytes to copy to name
8879  *
8880  *	Get device physical port name
8881  */
8882 int dev_get_phys_port_name(struct net_device *dev,
8883 			   char *name, size_t len)
8884 {
8885 	const struct net_device_ops *ops = dev->netdev_ops;
8886 	int err;
8887 
8888 	if (ops->ndo_get_phys_port_name) {
8889 		err = ops->ndo_get_phys_port_name(dev, name, len);
8890 		if (err != -EOPNOTSUPP)
8891 			return err;
8892 	}
8893 	return devlink_compat_phys_port_name_get(dev, name, len);
8894 }
8895 
8896 /**
8897  *	dev_get_port_parent_id - Get the device's port parent identifier
8898  *	@dev: network device
8899  *	@ppid: pointer to a storage for the port's parent identifier
8900  *	@recurse: allow/disallow recursion to lower devices
8901  *
8902  *	Get the devices's port parent identifier
8903  */
8904 int dev_get_port_parent_id(struct net_device *dev,
8905 			   struct netdev_phys_item_id *ppid,
8906 			   bool recurse)
8907 {
8908 	const struct net_device_ops *ops = dev->netdev_ops;
8909 	struct netdev_phys_item_id first = { };
8910 	struct net_device *lower_dev;
8911 	struct list_head *iter;
8912 	int err;
8913 
8914 	if (ops->ndo_get_port_parent_id) {
8915 		err = ops->ndo_get_port_parent_id(dev, ppid);
8916 		if (err != -EOPNOTSUPP)
8917 			return err;
8918 	}
8919 
8920 	err = devlink_compat_switch_id_get(dev, ppid);
8921 	if (!recurse || err != -EOPNOTSUPP)
8922 		return err;
8923 
8924 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
8925 		err = dev_get_port_parent_id(lower_dev, ppid, true);
8926 		if (err)
8927 			break;
8928 		if (!first.id_len)
8929 			first = *ppid;
8930 		else if (memcmp(&first, ppid, sizeof(*ppid)))
8931 			return -EOPNOTSUPP;
8932 	}
8933 
8934 	return err;
8935 }
8936 EXPORT_SYMBOL(dev_get_port_parent_id);
8937 
8938 /**
8939  *	netdev_port_same_parent_id - Indicate if two network devices have
8940  *	the same port parent identifier
8941  *	@a: first network device
8942  *	@b: second network device
8943  */
8944 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8945 {
8946 	struct netdev_phys_item_id a_id = { };
8947 	struct netdev_phys_item_id b_id = { };
8948 
8949 	if (dev_get_port_parent_id(a, &a_id, true) ||
8950 	    dev_get_port_parent_id(b, &b_id, true))
8951 		return false;
8952 
8953 	return netdev_phys_item_id_same(&a_id, &b_id);
8954 }
8955 EXPORT_SYMBOL(netdev_port_same_parent_id);
8956 
8957 /**
8958  *	dev_change_proto_down - set carrier according to proto_down.
8959  *
8960  *	@dev: device
8961  *	@proto_down: new value
8962  */
8963 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8964 {
8965 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8966 		return -EOPNOTSUPP;
8967 	if (!netif_device_present(dev))
8968 		return -ENODEV;
8969 	if (proto_down)
8970 		netif_carrier_off(dev);
8971 	else
8972 		netif_carrier_on(dev);
8973 	dev->proto_down = proto_down;
8974 	return 0;
8975 }
8976 
8977 /**
8978  *	dev_change_proto_down_reason - proto down reason
8979  *
8980  *	@dev: device
8981  *	@mask: proto down mask
8982  *	@value: proto down value
8983  */
8984 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
8985 				  u32 value)
8986 {
8987 	int b;
8988 
8989 	if (!mask) {
8990 		dev->proto_down_reason = value;
8991 	} else {
8992 		for_each_set_bit(b, &mask, 32) {
8993 			if (value & (1 << b))
8994 				dev->proto_down_reason |= BIT(b);
8995 			else
8996 				dev->proto_down_reason &= ~BIT(b);
8997 		}
8998 	}
8999 }
9000 
9001 struct bpf_xdp_link {
9002 	struct bpf_link link;
9003 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9004 	int flags;
9005 };
9006 
9007 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9008 {
9009 	if (flags & XDP_FLAGS_HW_MODE)
9010 		return XDP_MODE_HW;
9011 	if (flags & XDP_FLAGS_DRV_MODE)
9012 		return XDP_MODE_DRV;
9013 	if (flags & XDP_FLAGS_SKB_MODE)
9014 		return XDP_MODE_SKB;
9015 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9016 }
9017 
9018 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9019 {
9020 	switch (mode) {
9021 	case XDP_MODE_SKB:
9022 		return generic_xdp_install;
9023 	case XDP_MODE_DRV:
9024 	case XDP_MODE_HW:
9025 		return dev->netdev_ops->ndo_bpf;
9026 	default:
9027 		return NULL;
9028 	}
9029 }
9030 
9031 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9032 					 enum bpf_xdp_mode mode)
9033 {
9034 	return dev->xdp_state[mode].link;
9035 }
9036 
9037 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9038 				     enum bpf_xdp_mode mode)
9039 {
9040 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9041 
9042 	if (link)
9043 		return link->link.prog;
9044 	return dev->xdp_state[mode].prog;
9045 }
9046 
9047 u8 dev_xdp_prog_count(struct net_device *dev)
9048 {
9049 	u8 count = 0;
9050 	int i;
9051 
9052 	for (i = 0; i < __MAX_XDP_MODE; i++)
9053 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9054 			count++;
9055 	return count;
9056 }
9057 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9058 
9059 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9060 {
9061 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9062 
9063 	return prog ? prog->aux->id : 0;
9064 }
9065 
9066 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9067 			     struct bpf_xdp_link *link)
9068 {
9069 	dev->xdp_state[mode].link = link;
9070 	dev->xdp_state[mode].prog = NULL;
9071 }
9072 
9073 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9074 			     struct bpf_prog *prog)
9075 {
9076 	dev->xdp_state[mode].link = NULL;
9077 	dev->xdp_state[mode].prog = prog;
9078 }
9079 
9080 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9081 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9082 			   u32 flags, struct bpf_prog *prog)
9083 {
9084 	struct netdev_bpf xdp;
9085 	int err;
9086 
9087 	memset(&xdp, 0, sizeof(xdp));
9088 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9089 	xdp.extack = extack;
9090 	xdp.flags = flags;
9091 	xdp.prog = prog;
9092 
9093 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9094 	 * "moved" into driver), so they don't increment it on their own, but
9095 	 * they do decrement refcnt when program is detached or replaced.
9096 	 * Given net_device also owns link/prog, we need to bump refcnt here
9097 	 * to prevent drivers from underflowing it.
9098 	 */
9099 	if (prog)
9100 		bpf_prog_inc(prog);
9101 	err = bpf_op(dev, &xdp);
9102 	if (err) {
9103 		if (prog)
9104 			bpf_prog_put(prog);
9105 		return err;
9106 	}
9107 
9108 	if (mode != XDP_MODE_HW)
9109 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9110 
9111 	return 0;
9112 }
9113 
9114 static void dev_xdp_uninstall(struct net_device *dev)
9115 {
9116 	struct bpf_xdp_link *link;
9117 	struct bpf_prog *prog;
9118 	enum bpf_xdp_mode mode;
9119 	bpf_op_t bpf_op;
9120 
9121 	ASSERT_RTNL();
9122 
9123 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9124 		prog = dev_xdp_prog(dev, mode);
9125 		if (!prog)
9126 			continue;
9127 
9128 		bpf_op = dev_xdp_bpf_op(dev, mode);
9129 		if (!bpf_op)
9130 			continue;
9131 
9132 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9133 
9134 		/* auto-detach link from net device */
9135 		link = dev_xdp_link(dev, mode);
9136 		if (link)
9137 			link->dev = NULL;
9138 		else
9139 			bpf_prog_put(prog);
9140 
9141 		dev_xdp_set_link(dev, mode, NULL);
9142 	}
9143 }
9144 
9145 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9146 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9147 			  struct bpf_prog *old_prog, u32 flags)
9148 {
9149 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9150 	struct bpf_prog *cur_prog;
9151 	struct net_device *upper;
9152 	struct list_head *iter;
9153 	enum bpf_xdp_mode mode;
9154 	bpf_op_t bpf_op;
9155 	int err;
9156 
9157 	ASSERT_RTNL();
9158 
9159 	/* either link or prog attachment, never both */
9160 	if (link && (new_prog || old_prog))
9161 		return -EINVAL;
9162 	/* link supports only XDP mode flags */
9163 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9164 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9165 		return -EINVAL;
9166 	}
9167 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9168 	if (num_modes > 1) {
9169 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9170 		return -EINVAL;
9171 	}
9172 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9173 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9174 		NL_SET_ERR_MSG(extack,
9175 			       "More than one program loaded, unset mode is ambiguous");
9176 		return -EINVAL;
9177 	}
9178 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9179 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9180 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9181 		return -EINVAL;
9182 	}
9183 
9184 	mode = dev_xdp_mode(dev, flags);
9185 	/* can't replace attached link */
9186 	if (dev_xdp_link(dev, mode)) {
9187 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9188 		return -EBUSY;
9189 	}
9190 
9191 	/* don't allow if an upper device already has a program */
9192 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9193 		if (dev_xdp_prog_count(upper) > 0) {
9194 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9195 			return -EEXIST;
9196 		}
9197 	}
9198 
9199 	cur_prog = dev_xdp_prog(dev, mode);
9200 	/* can't replace attached prog with link */
9201 	if (link && cur_prog) {
9202 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9203 		return -EBUSY;
9204 	}
9205 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9206 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9207 		return -EEXIST;
9208 	}
9209 
9210 	/* put effective new program into new_prog */
9211 	if (link)
9212 		new_prog = link->link.prog;
9213 
9214 	if (new_prog) {
9215 		bool offload = mode == XDP_MODE_HW;
9216 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9217 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9218 
9219 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9220 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9221 			return -EBUSY;
9222 		}
9223 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9224 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9225 			return -EEXIST;
9226 		}
9227 		if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
9228 			NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
9229 			return -EINVAL;
9230 		}
9231 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9232 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9233 			return -EINVAL;
9234 		}
9235 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9236 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9237 			return -EINVAL;
9238 		}
9239 	}
9240 
9241 	/* don't call drivers if the effective program didn't change */
9242 	if (new_prog != cur_prog) {
9243 		bpf_op = dev_xdp_bpf_op(dev, mode);
9244 		if (!bpf_op) {
9245 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9246 			return -EOPNOTSUPP;
9247 		}
9248 
9249 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9250 		if (err)
9251 			return err;
9252 	}
9253 
9254 	if (link)
9255 		dev_xdp_set_link(dev, mode, link);
9256 	else
9257 		dev_xdp_set_prog(dev, mode, new_prog);
9258 	if (cur_prog)
9259 		bpf_prog_put(cur_prog);
9260 
9261 	return 0;
9262 }
9263 
9264 static int dev_xdp_attach_link(struct net_device *dev,
9265 			       struct netlink_ext_ack *extack,
9266 			       struct bpf_xdp_link *link)
9267 {
9268 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9269 }
9270 
9271 static int dev_xdp_detach_link(struct net_device *dev,
9272 			       struct netlink_ext_ack *extack,
9273 			       struct bpf_xdp_link *link)
9274 {
9275 	enum bpf_xdp_mode mode;
9276 	bpf_op_t bpf_op;
9277 
9278 	ASSERT_RTNL();
9279 
9280 	mode = dev_xdp_mode(dev, link->flags);
9281 	if (dev_xdp_link(dev, mode) != link)
9282 		return -EINVAL;
9283 
9284 	bpf_op = dev_xdp_bpf_op(dev, mode);
9285 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9286 	dev_xdp_set_link(dev, mode, NULL);
9287 	return 0;
9288 }
9289 
9290 static void bpf_xdp_link_release(struct bpf_link *link)
9291 {
9292 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9293 
9294 	rtnl_lock();
9295 
9296 	/* if racing with net_device's tear down, xdp_link->dev might be
9297 	 * already NULL, in which case link was already auto-detached
9298 	 */
9299 	if (xdp_link->dev) {
9300 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9301 		xdp_link->dev = NULL;
9302 	}
9303 
9304 	rtnl_unlock();
9305 }
9306 
9307 static int bpf_xdp_link_detach(struct bpf_link *link)
9308 {
9309 	bpf_xdp_link_release(link);
9310 	return 0;
9311 }
9312 
9313 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9314 {
9315 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9316 
9317 	kfree(xdp_link);
9318 }
9319 
9320 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9321 				     struct seq_file *seq)
9322 {
9323 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9324 	u32 ifindex = 0;
9325 
9326 	rtnl_lock();
9327 	if (xdp_link->dev)
9328 		ifindex = xdp_link->dev->ifindex;
9329 	rtnl_unlock();
9330 
9331 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9332 }
9333 
9334 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9335 				       struct bpf_link_info *info)
9336 {
9337 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9338 	u32 ifindex = 0;
9339 
9340 	rtnl_lock();
9341 	if (xdp_link->dev)
9342 		ifindex = xdp_link->dev->ifindex;
9343 	rtnl_unlock();
9344 
9345 	info->xdp.ifindex = ifindex;
9346 	return 0;
9347 }
9348 
9349 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9350 			       struct bpf_prog *old_prog)
9351 {
9352 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9353 	enum bpf_xdp_mode mode;
9354 	bpf_op_t bpf_op;
9355 	int err = 0;
9356 
9357 	rtnl_lock();
9358 
9359 	/* link might have been auto-released already, so fail */
9360 	if (!xdp_link->dev) {
9361 		err = -ENOLINK;
9362 		goto out_unlock;
9363 	}
9364 
9365 	if (old_prog && link->prog != old_prog) {
9366 		err = -EPERM;
9367 		goto out_unlock;
9368 	}
9369 	old_prog = link->prog;
9370 	if (old_prog->type != new_prog->type ||
9371 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9372 		err = -EINVAL;
9373 		goto out_unlock;
9374 	}
9375 
9376 	if (old_prog == new_prog) {
9377 		/* no-op, don't disturb drivers */
9378 		bpf_prog_put(new_prog);
9379 		goto out_unlock;
9380 	}
9381 
9382 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9383 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9384 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9385 			      xdp_link->flags, new_prog);
9386 	if (err)
9387 		goto out_unlock;
9388 
9389 	old_prog = xchg(&link->prog, new_prog);
9390 	bpf_prog_put(old_prog);
9391 
9392 out_unlock:
9393 	rtnl_unlock();
9394 	return err;
9395 }
9396 
9397 static const struct bpf_link_ops bpf_xdp_link_lops = {
9398 	.release = bpf_xdp_link_release,
9399 	.dealloc = bpf_xdp_link_dealloc,
9400 	.detach = bpf_xdp_link_detach,
9401 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9402 	.fill_link_info = bpf_xdp_link_fill_link_info,
9403 	.update_prog = bpf_xdp_link_update,
9404 };
9405 
9406 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9407 {
9408 	struct net *net = current->nsproxy->net_ns;
9409 	struct bpf_link_primer link_primer;
9410 	struct bpf_xdp_link *link;
9411 	struct net_device *dev;
9412 	int err, fd;
9413 
9414 	rtnl_lock();
9415 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9416 	if (!dev) {
9417 		rtnl_unlock();
9418 		return -EINVAL;
9419 	}
9420 
9421 	link = kzalloc(sizeof(*link), GFP_USER);
9422 	if (!link) {
9423 		err = -ENOMEM;
9424 		goto unlock;
9425 	}
9426 
9427 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9428 	link->dev = dev;
9429 	link->flags = attr->link_create.flags;
9430 
9431 	err = bpf_link_prime(&link->link, &link_primer);
9432 	if (err) {
9433 		kfree(link);
9434 		goto unlock;
9435 	}
9436 
9437 	err = dev_xdp_attach_link(dev, NULL, link);
9438 	rtnl_unlock();
9439 
9440 	if (err) {
9441 		link->dev = NULL;
9442 		bpf_link_cleanup(&link_primer);
9443 		goto out_put_dev;
9444 	}
9445 
9446 	fd = bpf_link_settle(&link_primer);
9447 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9448 	dev_put(dev);
9449 	return fd;
9450 
9451 unlock:
9452 	rtnl_unlock();
9453 
9454 out_put_dev:
9455 	dev_put(dev);
9456 	return err;
9457 }
9458 
9459 /**
9460  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9461  *	@dev: device
9462  *	@extack: netlink extended ack
9463  *	@fd: new program fd or negative value to clear
9464  *	@expected_fd: old program fd that userspace expects to replace or clear
9465  *	@flags: xdp-related flags
9466  *
9467  *	Set or clear a bpf program for a device
9468  */
9469 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9470 		      int fd, int expected_fd, u32 flags)
9471 {
9472 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9473 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9474 	int err;
9475 
9476 	ASSERT_RTNL();
9477 
9478 	if (fd >= 0) {
9479 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9480 						 mode != XDP_MODE_SKB);
9481 		if (IS_ERR(new_prog))
9482 			return PTR_ERR(new_prog);
9483 	}
9484 
9485 	if (expected_fd >= 0) {
9486 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9487 						 mode != XDP_MODE_SKB);
9488 		if (IS_ERR(old_prog)) {
9489 			err = PTR_ERR(old_prog);
9490 			old_prog = NULL;
9491 			goto err_out;
9492 		}
9493 	}
9494 
9495 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9496 
9497 err_out:
9498 	if (err && new_prog)
9499 		bpf_prog_put(new_prog);
9500 	if (old_prog)
9501 		bpf_prog_put(old_prog);
9502 	return err;
9503 }
9504 
9505 /**
9506  *	dev_new_index	-	allocate an ifindex
9507  *	@net: the applicable net namespace
9508  *
9509  *	Returns a suitable unique value for a new device interface
9510  *	number.  The caller must hold the rtnl semaphore or the
9511  *	dev_base_lock to be sure it remains unique.
9512  */
9513 static int dev_new_index(struct net *net)
9514 {
9515 	int ifindex = net->ifindex;
9516 
9517 	for (;;) {
9518 		if (++ifindex <= 0)
9519 			ifindex = 1;
9520 		if (!__dev_get_by_index(net, ifindex))
9521 			return net->ifindex = ifindex;
9522 	}
9523 }
9524 
9525 /* Delayed registration/unregisteration */
9526 LIST_HEAD(net_todo_list);
9527 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9528 
9529 static void net_set_todo(struct net_device *dev)
9530 {
9531 	list_add_tail(&dev->todo_list, &net_todo_list);
9532 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9533 }
9534 
9535 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9536 	struct net_device *upper, netdev_features_t features)
9537 {
9538 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9539 	netdev_features_t feature;
9540 	int feature_bit;
9541 
9542 	for_each_netdev_feature(upper_disables, feature_bit) {
9543 		feature = __NETIF_F_BIT(feature_bit);
9544 		if (!(upper->wanted_features & feature)
9545 		    && (features & feature)) {
9546 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9547 				   &feature, upper->name);
9548 			features &= ~feature;
9549 		}
9550 	}
9551 
9552 	return features;
9553 }
9554 
9555 static void netdev_sync_lower_features(struct net_device *upper,
9556 	struct net_device *lower, netdev_features_t features)
9557 {
9558 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9559 	netdev_features_t feature;
9560 	int feature_bit;
9561 
9562 	for_each_netdev_feature(upper_disables, feature_bit) {
9563 		feature = __NETIF_F_BIT(feature_bit);
9564 		if (!(features & feature) && (lower->features & feature)) {
9565 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9566 				   &feature, lower->name);
9567 			lower->wanted_features &= ~feature;
9568 			__netdev_update_features(lower);
9569 
9570 			if (unlikely(lower->features & feature))
9571 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9572 					    &feature, lower->name);
9573 			else
9574 				netdev_features_change(lower);
9575 		}
9576 	}
9577 }
9578 
9579 static netdev_features_t netdev_fix_features(struct net_device *dev,
9580 	netdev_features_t features)
9581 {
9582 	/* Fix illegal checksum combinations */
9583 	if ((features & NETIF_F_HW_CSUM) &&
9584 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9585 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9586 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9587 	}
9588 
9589 	/* TSO requires that SG is present as well. */
9590 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9591 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9592 		features &= ~NETIF_F_ALL_TSO;
9593 	}
9594 
9595 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9596 					!(features & NETIF_F_IP_CSUM)) {
9597 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9598 		features &= ~NETIF_F_TSO;
9599 		features &= ~NETIF_F_TSO_ECN;
9600 	}
9601 
9602 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9603 					 !(features & NETIF_F_IPV6_CSUM)) {
9604 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9605 		features &= ~NETIF_F_TSO6;
9606 	}
9607 
9608 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9609 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9610 		features &= ~NETIF_F_TSO_MANGLEID;
9611 
9612 	/* TSO ECN requires that TSO is present as well. */
9613 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9614 		features &= ~NETIF_F_TSO_ECN;
9615 
9616 	/* Software GSO depends on SG. */
9617 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9618 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9619 		features &= ~NETIF_F_GSO;
9620 	}
9621 
9622 	/* GSO partial features require GSO partial be set */
9623 	if ((features & dev->gso_partial_features) &&
9624 	    !(features & NETIF_F_GSO_PARTIAL)) {
9625 		netdev_dbg(dev,
9626 			   "Dropping partially supported GSO features since no GSO partial.\n");
9627 		features &= ~dev->gso_partial_features;
9628 	}
9629 
9630 	if (!(features & NETIF_F_RXCSUM)) {
9631 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9632 		 * successfully merged by hardware must also have the
9633 		 * checksum verified by hardware.  If the user does not
9634 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9635 		 */
9636 		if (features & NETIF_F_GRO_HW) {
9637 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9638 			features &= ~NETIF_F_GRO_HW;
9639 		}
9640 	}
9641 
9642 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9643 	if (features & NETIF_F_RXFCS) {
9644 		if (features & NETIF_F_LRO) {
9645 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9646 			features &= ~NETIF_F_LRO;
9647 		}
9648 
9649 		if (features & NETIF_F_GRO_HW) {
9650 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9651 			features &= ~NETIF_F_GRO_HW;
9652 		}
9653 	}
9654 
9655 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9656 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9657 		features &= ~NETIF_F_LRO;
9658 	}
9659 
9660 	if (features & NETIF_F_HW_TLS_TX) {
9661 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9662 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9663 		bool hw_csum = features & NETIF_F_HW_CSUM;
9664 
9665 		if (!ip_csum && !hw_csum) {
9666 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9667 			features &= ~NETIF_F_HW_TLS_TX;
9668 		}
9669 	}
9670 
9671 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9672 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9673 		features &= ~NETIF_F_HW_TLS_RX;
9674 	}
9675 
9676 	return features;
9677 }
9678 
9679 int __netdev_update_features(struct net_device *dev)
9680 {
9681 	struct net_device *upper, *lower;
9682 	netdev_features_t features;
9683 	struct list_head *iter;
9684 	int err = -1;
9685 
9686 	ASSERT_RTNL();
9687 
9688 	features = netdev_get_wanted_features(dev);
9689 
9690 	if (dev->netdev_ops->ndo_fix_features)
9691 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9692 
9693 	/* driver might be less strict about feature dependencies */
9694 	features = netdev_fix_features(dev, features);
9695 
9696 	/* some features can't be enabled if they're off on an upper device */
9697 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9698 		features = netdev_sync_upper_features(dev, upper, features);
9699 
9700 	if (dev->features == features)
9701 		goto sync_lower;
9702 
9703 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9704 		&dev->features, &features);
9705 
9706 	if (dev->netdev_ops->ndo_set_features)
9707 		err = dev->netdev_ops->ndo_set_features(dev, features);
9708 	else
9709 		err = 0;
9710 
9711 	if (unlikely(err < 0)) {
9712 		netdev_err(dev,
9713 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9714 			err, &features, &dev->features);
9715 		/* return non-0 since some features might have changed and
9716 		 * it's better to fire a spurious notification than miss it
9717 		 */
9718 		return -1;
9719 	}
9720 
9721 sync_lower:
9722 	/* some features must be disabled on lower devices when disabled
9723 	 * on an upper device (think: bonding master or bridge)
9724 	 */
9725 	netdev_for_each_lower_dev(dev, lower, iter)
9726 		netdev_sync_lower_features(dev, lower, features);
9727 
9728 	if (!err) {
9729 		netdev_features_t diff = features ^ dev->features;
9730 
9731 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9732 			/* udp_tunnel_{get,drop}_rx_info both need
9733 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9734 			 * device, or they won't do anything.
9735 			 * Thus we need to update dev->features
9736 			 * *before* calling udp_tunnel_get_rx_info,
9737 			 * but *after* calling udp_tunnel_drop_rx_info.
9738 			 */
9739 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9740 				dev->features = features;
9741 				udp_tunnel_get_rx_info(dev);
9742 			} else {
9743 				udp_tunnel_drop_rx_info(dev);
9744 			}
9745 		}
9746 
9747 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9748 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9749 				dev->features = features;
9750 				err |= vlan_get_rx_ctag_filter_info(dev);
9751 			} else {
9752 				vlan_drop_rx_ctag_filter_info(dev);
9753 			}
9754 		}
9755 
9756 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9757 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9758 				dev->features = features;
9759 				err |= vlan_get_rx_stag_filter_info(dev);
9760 			} else {
9761 				vlan_drop_rx_stag_filter_info(dev);
9762 			}
9763 		}
9764 
9765 		dev->features = features;
9766 	}
9767 
9768 	return err < 0 ? 0 : 1;
9769 }
9770 
9771 /**
9772  *	netdev_update_features - recalculate device features
9773  *	@dev: the device to check
9774  *
9775  *	Recalculate dev->features set and send notifications if it
9776  *	has changed. Should be called after driver or hardware dependent
9777  *	conditions might have changed that influence the features.
9778  */
9779 void netdev_update_features(struct net_device *dev)
9780 {
9781 	if (__netdev_update_features(dev))
9782 		netdev_features_change(dev);
9783 }
9784 EXPORT_SYMBOL(netdev_update_features);
9785 
9786 /**
9787  *	netdev_change_features - recalculate device features
9788  *	@dev: the device to check
9789  *
9790  *	Recalculate dev->features set and send notifications even
9791  *	if they have not changed. Should be called instead of
9792  *	netdev_update_features() if also dev->vlan_features might
9793  *	have changed to allow the changes to be propagated to stacked
9794  *	VLAN devices.
9795  */
9796 void netdev_change_features(struct net_device *dev)
9797 {
9798 	__netdev_update_features(dev);
9799 	netdev_features_change(dev);
9800 }
9801 EXPORT_SYMBOL(netdev_change_features);
9802 
9803 /**
9804  *	netif_stacked_transfer_operstate -	transfer operstate
9805  *	@rootdev: the root or lower level device to transfer state from
9806  *	@dev: the device to transfer operstate to
9807  *
9808  *	Transfer operational state from root to device. This is normally
9809  *	called when a stacking relationship exists between the root
9810  *	device and the device(a leaf device).
9811  */
9812 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9813 					struct net_device *dev)
9814 {
9815 	if (rootdev->operstate == IF_OPER_DORMANT)
9816 		netif_dormant_on(dev);
9817 	else
9818 		netif_dormant_off(dev);
9819 
9820 	if (rootdev->operstate == IF_OPER_TESTING)
9821 		netif_testing_on(dev);
9822 	else
9823 		netif_testing_off(dev);
9824 
9825 	if (netif_carrier_ok(rootdev))
9826 		netif_carrier_on(dev);
9827 	else
9828 		netif_carrier_off(dev);
9829 }
9830 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9831 
9832 static int netif_alloc_rx_queues(struct net_device *dev)
9833 {
9834 	unsigned int i, count = dev->num_rx_queues;
9835 	struct netdev_rx_queue *rx;
9836 	size_t sz = count * sizeof(*rx);
9837 	int err = 0;
9838 
9839 	BUG_ON(count < 1);
9840 
9841 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9842 	if (!rx)
9843 		return -ENOMEM;
9844 
9845 	dev->_rx = rx;
9846 
9847 	for (i = 0; i < count; i++) {
9848 		rx[i].dev = dev;
9849 
9850 		/* XDP RX-queue setup */
9851 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9852 		if (err < 0)
9853 			goto err_rxq_info;
9854 	}
9855 	return 0;
9856 
9857 err_rxq_info:
9858 	/* Rollback successful reg's and free other resources */
9859 	while (i--)
9860 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9861 	kvfree(dev->_rx);
9862 	dev->_rx = NULL;
9863 	return err;
9864 }
9865 
9866 static void netif_free_rx_queues(struct net_device *dev)
9867 {
9868 	unsigned int i, count = dev->num_rx_queues;
9869 
9870 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9871 	if (!dev->_rx)
9872 		return;
9873 
9874 	for (i = 0; i < count; i++)
9875 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9876 
9877 	kvfree(dev->_rx);
9878 }
9879 
9880 static void netdev_init_one_queue(struct net_device *dev,
9881 				  struct netdev_queue *queue, void *_unused)
9882 {
9883 	/* Initialize queue lock */
9884 	spin_lock_init(&queue->_xmit_lock);
9885 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9886 	queue->xmit_lock_owner = -1;
9887 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9888 	queue->dev = dev;
9889 #ifdef CONFIG_BQL
9890 	dql_init(&queue->dql, HZ);
9891 #endif
9892 }
9893 
9894 static void netif_free_tx_queues(struct net_device *dev)
9895 {
9896 	kvfree(dev->_tx);
9897 }
9898 
9899 static int netif_alloc_netdev_queues(struct net_device *dev)
9900 {
9901 	unsigned int count = dev->num_tx_queues;
9902 	struct netdev_queue *tx;
9903 	size_t sz = count * sizeof(*tx);
9904 
9905 	if (count < 1 || count > 0xffff)
9906 		return -EINVAL;
9907 
9908 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9909 	if (!tx)
9910 		return -ENOMEM;
9911 
9912 	dev->_tx = tx;
9913 
9914 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9915 	spin_lock_init(&dev->tx_global_lock);
9916 
9917 	return 0;
9918 }
9919 
9920 void netif_tx_stop_all_queues(struct net_device *dev)
9921 {
9922 	unsigned int i;
9923 
9924 	for (i = 0; i < dev->num_tx_queues; i++) {
9925 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9926 
9927 		netif_tx_stop_queue(txq);
9928 	}
9929 }
9930 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9931 
9932 /**
9933  * register_netdevice() - register a network device
9934  * @dev: device to register
9935  *
9936  * Take a prepared network device structure and make it externally accessible.
9937  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9938  * Callers must hold the rtnl lock - you may want register_netdev()
9939  * instead of this.
9940  */
9941 int register_netdevice(struct net_device *dev)
9942 {
9943 	int ret;
9944 	struct net *net = dev_net(dev);
9945 
9946 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9947 		     NETDEV_FEATURE_COUNT);
9948 	BUG_ON(dev_boot_phase);
9949 	ASSERT_RTNL();
9950 
9951 	might_sleep();
9952 
9953 	/* When net_device's are persistent, this will be fatal. */
9954 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9955 	BUG_ON(!net);
9956 
9957 	ret = ethtool_check_ops(dev->ethtool_ops);
9958 	if (ret)
9959 		return ret;
9960 
9961 	spin_lock_init(&dev->addr_list_lock);
9962 	netdev_set_addr_lockdep_class(dev);
9963 
9964 	ret = dev_get_valid_name(net, dev, dev->name);
9965 	if (ret < 0)
9966 		goto out;
9967 
9968 	ret = -ENOMEM;
9969 	dev->name_node = netdev_name_node_head_alloc(dev);
9970 	if (!dev->name_node)
9971 		goto out;
9972 
9973 	/* Init, if this function is available */
9974 	if (dev->netdev_ops->ndo_init) {
9975 		ret = dev->netdev_ops->ndo_init(dev);
9976 		if (ret) {
9977 			if (ret > 0)
9978 				ret = -EIO;
9979 			goto err_free_name;
9980 		}
9981 	}
9982 
9983 	if (((dev->hw_features | dev->features) &
9984 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
9985 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
9986 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
9987 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
9988 		ret = -EINVAL;
9989 		goto err_uninit;
9990 	}
9991 
9992 	ret = -EBUSY;
9993 	if (!dev->ifindex)
9994 		dev->ifindex = dev_new_index(net);
9995 	else if (__dev_get_by_index(net, dev->ifindex))
9996 		goto err_uninit;
9997 
9998 	/* Transfer changeable features to wanted_features and enable
9999 	 * software offloads (GSO and GRO).
10000 	 */
10001 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10002 	dev->features |= NETIF_F_SOFT_FEATURES;
10003 
10004 	if (dev->udp_tunnel_nic_info) {
10005 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10006 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10007 	}
10008 
10009 	dev->wanted_features = dev->features & dev->hw_features;
10010 
10011 	if (!(dev->flags & IFF_LOOPBACK))
10012 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10013 
10014 	/* If IPv4 TCP segmentation offload is supported we should also
10015 	 * allow the device to enable segmenting the frame with the option
10016 	 * of ignoring a static IP ID value.  This doesn't enable the
10017 	 * feature itself but allows the user to enable it later.
10018 	 */
10019 	if (dev->hw_features & NETIF_F_TSO)
10020 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10021 	if (dev->vlan_features & NETIF_F_TSO)
10022 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10023 	if (dev->mpls_features & NETIF_F_TSO)
10024 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10025 	if (dev->hw_enc_features & NETIF_F_TSO)
10026 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10027 
10028 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10029 	 */
10030 	dev->vlan_features |= NETIF_F_HIGHDMA;
10031 
10032 	/* Make NETIF_F_SG inheritable to tunnel devices.
10033 	 */
10034 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10035 
10036 	/* Make NETIF_F_SG inheritable to MPLS.
10037 	 */
10038 	dev->mpls_features |= NETIF_F_SG;
10039 
10040 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10041 	ret = notifier_to_errno(ret);
10042 	if (ret)
10043 		goto err_uninit;
10044 
10045 	ret = netdev_register_kobject(dev);
10046 	write_lock(&dev_base_lock);
10047 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10048 	write_unlock(&dev_base_lock);
10049 	if (ret)
10050 		goto err_uninit_notify;
10051 
10052 	__netdev_update_features(dev);
10053 
10054 	/*
10055 	 *	Default initial state at registry is that the
10056 	 *	device is present.
10057 	 */
10058 
10059 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10060 
10061 	linkwatch_init_dev(dev);
10062 
10063 	dev_init_scheduler(dev);
10064 
10065 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10066 	list_netdevice(dev);
10067 
10068 	add_device_randomness(dev->dev_addr, dev->addr_len);
10069 
10070 	/* If the device has permanent device address, driver should
10071 	 * set dev_addr and also addr_assign_type should be set to
10072 	 * NET_ADDR_PERM (default value).
10073 	 */
10074 	if (dev->addr_assign_type == NET_ADDR_PERM)
10075 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10076 
10077 	/* Notify protocols, that a new device appeared. */
10078 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10079 	ret = notifier_to_errno(ret);
10080 	if (ret) {
10081 		/* Expect explicit free_netdev() on failure */
10082 		dev->needs_free_netdev = false;
10083 		unregister_netdevice_queue(dev, NULL);
10084 		goto out;
10085 	}
10086 	/*
10087 	 *	Prevent userspace races by waiting until the network
10088 	 *	device is fully setup before sending notifications.
10089 	 */
10090 	if (!dev->rtnl_link_ops ||
10091 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10092 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10093 
10094 out:
10095 	return ret;
10096 
10097 err_uninit_notify:
10098 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10099 err_uninit:
10100 	if (dev->netdev_ops->ndo_uninit)
10101 		dev->netdev_ops->ndo_uninit(dev);
10102 	if (dev->priv_destructor)
10103 		dev->priv_destructor(dev);
10104 err_free_name:
10105 	netdev_name_node_free(dev->name_node);
10106 	goto out;
10107 }
10108 EXPORT_SYMBOL(register_netdevice);
10109 
10110 /**
10111  *	init_dummy_netdev	- init a dummy network device for NAPI
10112  *	@dev: device to init
10113  *
10114  *	This takes a network device structure and initialize the minimum
10115  *	amount of fields so it can be used to schedule NAPI polls without
10116  *	registering a full blown interface. This is to be used by drivers
10117  *	that need to tie several hardware interfaces to a single NAPI
10118  *	poll scheduler due to HW limitations.
10119  */
10120 int init_dummy_netdev(struct net_device *dev)
10121 {
10122 	/* Clear everything. Note we don't initialize spinlocks
10123 	 * are they aren't supposed to be taken by any of the
10124 	 * NAPI code and this dummy netdev is supposed to be
10125 	 * only ever used for NAPI polls
10126 	 */
10127 	memset(dev, 0, sizeof(struct net_device));
10128 
10129 	/* make sure we BUG if trying to hit standard
10130 	 * register/unregister code path
10131 	 */
10132 	dev->reg_state = NETREG_DUMMY;
10133 
10134 	/* NAPI wants this */
10135 	INIT_LIST_HEAD(&dev->napi_list);
10136 
10137 	/* a dummy interface is started by default */
10138 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10139 	set_bit(__LINK_STATE_START, &dev->state);
10140 
10141 	/* napi_busy_loop stats accounting wants this */
10142 	dev_net_set(dev, &init_net);
10143 
10144 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10145 	 * because users of this 'device' dont need to change
10146 	 * its refcount.
10147 	 */
10148 
10149 	return 0;
10150 }
10151 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10152 
10153 
10154 /**
10155  *	register_netdev	- register a network device
10156  *	@dev: device to register
10157  *
10158  *	Take a completed network device structure and add it to the kernel
10159  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10160  *	chain. 0 is returned on success. A negative errno code is returned
10161  *	on a failure to set up the device, or if the name is a duplicate.
10162  *
10163  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10164  *	and expands the device name if you passed a format string to
10165  *	alloc_netdev.
10166  */
10167 int register_netdev(struct net_device *dev)
10168 {
10169 	int err;
10170 
10171 	if (rtnl_lock_killable())
10172 		return -EINTR;
10173 	err = register_netdevice(dev);
10174 	rtnl_unlock();
10175 	return err;
10176 }
10177 EXPORT_SYMBOL(register_netdev);
10178 
10179 int netdev_refcnt_read(const struct net_device *dev)
10180 {
10181 #ifdef CONFIG_PCPU_DEV_REFCNT
10182 	int i, refcnt = 0;
10183 
10184 	for_each_possible_cpu(i)
10185 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10186 	return refcnt;
10187 #else
10188 	return refcount_read(&dev->dev_refcnt);
10189 #endif
10190 }
10191 EXPORT_SYMBOL(netdev_refcnt_read);
10192 
10193 int netdev_unregister_timeout_secs __read_mostly = 10;
10194 
10195 #define WAIT_REFS_MIN_MSECS 1
10196 #define WAIT_REFS_MAX_MSECS 250
10197 /**
10198  * netdev_wait_allrefs_any - wait until all references are gone.
10199  * @list: list of net_devices to wait on
10200  *
10201  * This is called when unregistering network devices.
10202  *
10203  * Any protocol or device that holds a reference should register
10204  * for netdevice notification, and cleanup and put back the
10205  * reference if they receive an UNREGISTER event.
10206  * We can get stuck here if buggy protocols don't correctly
10207  * call dev_put.
10208  */
10209 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10210 {
10211 	unsigned long rebroadcast_time, warning_time;
10212 	struct net_device *dev;
10213 	int wait = 0;
10214 
10215 	rebroadcast_time = warning_time = jiffies;
10216 
10217 	list_for_each_entry(dev, list, todo_list)
10218 		if (netdev_refcnt_read(dev) == 1)
10219 			return dev;
10220 
10221 	while (true) {
10222 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10223 			rtnl_lock();
10224 
10225 			/* Rebroadcast unregister notification */
10226 			list_for_each_entry(dev, list, todo_list)
10227 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10228 
10229 			__rtnl_unlock();
10230 			rcu_barrier();
10231 			rtnl_lock();
10232 
10233 			list_for_each_entry(dev, list, todo_list)
10234 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10235 					     &dev->state)) {
10236 					/* We must not have linkwatch events
10237 					 * pending on unregister. If this
10238 					 * happens, we simply run the queue
10239 					 * unscheduled, resulting in a noop
10240 					 * for this device.
10241 					 */
10242 					linkwatch_run_queue();
10243 					break;
10244 				}
10245 
10246 			__rtnl_unlock();
10247 
10248 			rebroadcast_time = jiffies;
10249 		}
10250 
10251 		if (!wait) {
10252 			rcu_barrier();
10253 			wait = WAIT_REFS_MIN_MSECS;
10254 		} else {
10255 			msleep(wait);
10256 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10257 		}
10258 
10259 		list_for_each_entry(dev, list, todo_list)
10260 			if (netdev_refcnt_read(dev) == 1)
10261 				return dev;
10262 
10263 		if (time_after(jiffies, warning_time +
10264 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10265 			list_for_each_entry(dev, list, todo_list) {
10266 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10267 					 dev->name, netdev_refcnt_read(dev));
10268 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10269 			}
10270 
10271 			warning_time = jiffies;
10272 		}
10273 	}
10274 }
10275 
10276 /* The sequence is:
10277  *
10278  *	rtnl_lock();
10279  *	...
10280  *	register_netdevice(x1);
10281  *	register_netdevice(x2);
10282  *	...
10283  *	unregister_netdevice(y1);
10284  *	unregister_netdevice(y2);
10285  *      ...
10286  *	rtnl_unlock();
10287  *	free_netdev(y1);
10288  *	free_netdev(y2);
10289  *
10290  * We are invoked by rtnl_unlock().
10291  * This allows us to deal with problems:
10292  * 1) We can delete sysfs objects which invoke hotplug
10293  *    without deadlocking with linkwatch via keventd.
10294  * 2) Since we run with the RTNL semaphore not held, we can sleep
10295  *    safely in order to wait for the netdev refcnt to drop to zero.
10296  *
10297  * We must not return until all unregister events added during
10298  * the interval the lock was held have been completed.
10299  */
10300 void netdev_run_todo(void)
10301 {
10302 	struct net_device *dev, *tmp;
10303 	struct list_head list;
10304 #ifdef CONFIG_LOCKDEP
10305 	struct list_head unlink_list;
10306 
10307 	list_replace_init(&net_unlink_list, &unlink_list);
10308 
10309 	while (!list_empty(&unlink_list)) {
10310 		struct net_device *dev = list_first_entry(&unlink_list,
10311 							  struct net_device,
10312 							  unlink_list);
10313 		list_del_init(&dev->unlink_list);
10314 		dev->nested_level = dev->lower_level - 1;
10315 	}
10316 #endif
10317 
10318 	/* Snapshot list, allow later requests */
10319 	list_replace_init(&net_todo_list, &list);
10320 
10321 	__rtnl_unlock();
10322 
10323 	/* Wait for rcu callbacks to finish before next phase */
10324 	if (!list_empty(&list))
10325 		rcu_barrier();
10326 
10327 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10328 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10329 			netdev_WARN(dev, "run_todo but not unregistering\n");
10330 			list_del(&dev->todo_list);
10331 			continue;
10332 		}
10333 
10334 		write_lock(&dev_base_lock);
10335 		dev->reg_state = NETREG_UNREGISTERED;
10336 		write_unlock(&dev_base_lock);
10337 		linkwatch_forget_dev(dev);
10338 	}
10339 
10340 	while (!list_empty(&list)) {
10341 		dev = netdev_wait_allrefs_any(&list);
10342 		list_del(&dev->todo_list);
10343 
10344 		/* paranoia */
10345 		BUG_ON(netdev_refcnt_read(dev) != 1);
10346 		BUG_ON(!list_empty(&dev->ptype_all));
10347 		BUG_ON(!list_empty(&dev->ptype_specific));
10348 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10349 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10350 
10351 		if (dev->priv_destructor)
10352 			dev->priv_destructor(dev);
10353 		if (dev->needs_free_netdev)
10354 			free_netdev(dev);
10355 
10356 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10357 			wake_up(&netdev_unregistering_wq);
10358 
10359 		/* Free network device */
10360 		kobject_put(&dev->dev.kobj);
10361 	}
10362 }
10363 
10364 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10365  * all the same fields in the same order as net_device_stats, with only
10366  * the type differing, but rtnl_link_stats64 may have additional fields
10367  * at the end for newer counters.
10368  */
10369 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10370 			     const struct net_device_stats *netdev_stats)
10371 {
10372 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10373 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10374 	u64 *dst = (u64 *)stats64;
10375 
10376 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10377 	for (i = 0; i < n; i++)
10378 		dst[i] = atomic_long_read(&src[i]);
10379 	/* zero out counters that only exist in rtnl_link_stats64 */
10380 	memset((char *)stats64 + n * sizeof(u64), 0,
10381 	       sizeof(*stats64) - n * sizeof(u64));
10382 }
10383 EXPORT_SYMBOL(netdev_stats_to_stats64);
10384 
10385 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10386 {
10387 	struct net_device_core_stats __percpu *p;
10388 
10389 	p = alloc_percpu_gfp(struct net_device_core_stats,
10390 			     GFP_ATOMIC | __GFP_NOWARN);
10391 
10392 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10393 		free_percpu(p);
10394 
10395 	/* This READ_ONCE() pairs with the cmpxchg() above */
10396 	return READ_ONCE(dev->core_stats);
10397 }
10398 EXPORT_SYMBOL(netdev_core_stats_alloc);
10399 
10400 /**
10401  *	dev_get_stats	- get network device statistics
10402  *	@dev: device to get statistics from
10403  *	@storage: place to store stats
10404  *
10405  *	Get network statistics from device. Return @storage.
10406  *	The device driver may provide its own method by setting
10407  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10408  *	otherwise the internal statistics structure is used.
10409  */
10410 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10411 					struct rtnl_link_stats64 *storage)
10412 {
10413 	const struct net_device_ops *ops = dev->netdev_ops;
10414 	const struct net_device_core_stats __percpu *p;
10415 
10416 	if (ops->ndo_get_stats64) {
10417 		memset(storage, 0, sizeof(*storage));
10418 		ops->ndo_get_stats64(dev, storage);
10419 	} else if (ops->ndo_get_stats) {
10420 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10421 	} else {
10422 		netdev_stats_to_stats64(storage, &dev->stats);
10423 	}
10424 
10425 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10426 	p = READ_ONCE(dev->core_stats);
10427 	if (p) {
10428 		const struct net_device_core_stats *core_stats;
10429 		int i;
10430 
10431 		for_each_possible_cpu(i) {
10432 			core_stats = per_cpu_ptr(p, i);
10433 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10434 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10435 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10436 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10437 		}
10438 	}
10439 	return storage;
10440 }
10441 EXPORT_SYMBOL(dev_get_stats);
10442 
10443 /**
10444  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10445  *	@s: place to store stats
10446  *	@netstats: per-cpu network stats to read from
10447  *
10448  *	Read per-cpu network statistics and populate the related fields in @s.
10449  */
10450 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10451 			   const struct pcpu_sw_netstats __percpu *netstats)
10452 {
10453 	int cpu;
10454 
10455 	for_each_possible_cpu(cpu) {
10456 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10457 		const struct pcpu_sw_netstats *stats;
10458 		unsigned int start;
10459 
10460 		stats = per_cpu_ptr(netstats, cpu);
10461 		do {
10462 			start = u64_stats_fetch_begin(&stats->syncp);
10463 			rx_packets = u64_stats_read(&stats->rx_packets);
10464 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10465 			tx_packets = u64_stats_read(&stats->tx_packets);
10466 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10467 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10468 
10469 		s->rx_packets += rx_packets;
10470 		s->rx_bytes   += rx_bytes;
10471 		s->tx_packets += tx_packets;
10472 		s->tx_bytes   += tx_bytes;
10473 	}
10474 }
10475 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10476 
10477 /**
10478  *	dev_get_tstats64 - ndo_get_stats64 implementation
10479  *	@dev: device to get statistics from
10480  *	@s: place to store stats
10481  *
10482  *	Populate @s from dev->stats and dev->tstats. Can be used as
10483  *	ndo_get_stats64() callback.
10484  */
10485 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10486 {
10487 	netdev_stats_to_stats64(s, &dev->stats);
10488 	dev_fetch_sw_netstats(s, dev->tstats);
10489 }
10490 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10491 
10492 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10493 {
10494 	struct netdev_queue *queue = dev_ingress_queue(dev);
10495 
10496 #ifdef CONFIG_NET_CLS_ACT
10497 	if (queue)
10498 		return queue;
10499 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10500 	if (!queue)
10501 		return NULL;
10502 	netdev_init_one_queue(dev, queue, NULL);
10503 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10504 	queue->qdisc_sleeping = &noop_qdisc;
10505 	rcu_assign_pointer(dev->ingress_queue, queue);
10506 #endif
10507 	return queue;
10508 }
10509 
10510 static const struct ethtool_ops default_ethtool_ops;
10511 
10512 void netdev_set_default_ethtool_ops(struct net_device *dev,
10513 				    const struct ethtool_ops *ops)
10514 {
10515 	if (dev->ethtool_ops == &default_ethtool_ops)
10516 		dev->ethtool_ops = ops;
10517 }
10518 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10519 
10520 /**
10521  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10522  * @dev: netdev to enable the IRQ coalescing on
10523  *
10524  * Sets a conservative default for SW IRQ coalescing. Users can use
10525  * sysfs attributes to override the default values.
10526  */
10527 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10528 {
10529 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10530 
10531 	dev->gro_flush_timeout = 20000;
10532 	dev->napi_defer_hard_irqs = 1;
10533 }
10534 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10535 
10536 void netdev_freemem(struct net_device *dev)
10537 {
10538 	char *addr = (char *)dev - dev->padded;
10539 
10540 	kvfree(addr);
10541 }
10542 
10543 /**
10544  * alloc_netdev_mqs - allocate network device
10545  * @sizeof_priv: size of private data to allocate space for
10546  * @name: device name format string
10547  * @name_assign_type: origin of device name
10548  * @setup: callback to initialize device
10549  * @txqs: the number of TX subqueues to allocate
10550  * @rxqs: the number of RX subqueues to allocate
10551  *
10552  * Allocates a struct net_device with private data area for driver use
10553  * and performs basic initialization.  Also allocates subqueue structs
10554  * for each queue on the device.
10555  */
10556 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10557 		unsigned char name_assign_type,
10558 		void (*setup)(struct net_device *),
10559 		unsigned int txqs, unsigned int rxqs)
10560 {
10561 	struct net_device *dev;
10562 	unsigned int alloc_size;
10563 	struct net_device *p;
10564 
10565 	BUG_ON(strlen(name) >= sizeof(dev->name));
10566 
10567 	if (txqs < 1) {
10568 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10569 		return NULL;
10570 	}
10571 
10572 	if (rxqs < 1) {
10573 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10574 		return NULL;
10575 	}
10576 
10577 	alloc_size = sizeof(struct net_device);
10578 	if (sizeof_priv) {
10579 		/* ensure 32-byte alignment of private area */
10580 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10581 		alloc_size += sizeof_priv;
10582 	}
10583 	/* ensure 32-byte alignment of whole construct */
10584 	alloc_size += NETDEV_ALIGN - 1;
10585 
10586 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10587 	if (!p)
10588 		return NULL;
10589 
10590 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10591 	dev->padded = (char *)dev - (char *)p;
10592 
10593 	ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10594 #ifdef CONFIG_PCPU_DEV_REFCNT
10595 	dev->pcpu_refcnt = alloc_percpu(int);
10596 	if (!dev->pcpu_refcnt)
10597 		goto free_dev;
10598 	__dev_hold(dev);
10599 #else
10600 	refcount_set(&dev->dev_refcnt, 1);
10601 #endif
10602 
10603 	if (dev_addr_init(dev))
10604 		goto free_pcpu;
10605 
10606 	dev_mc_init(dev);
10607 	dev_uc_init(dev);
10608 
10609 	dev_net_set(dev, &init_net);
10610 
10611 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10612 	dev->gso_max_segs = GSO_MAX_SEGS;
10613 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10614 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10615 	dev->tso_max_segs = TSO_MAX_SEGS;
10616 	dev->upper_level = 1;
10617 	dev->lower_level = 1;
10618 #ifdef CONFIG_LOCKDEP
10619 	dev->nested_level = 0;
10620 	INIT_LIST_HEAD(&dev->unlink_list);
10621 #endif
10622 
10623 	INIT_LIST_HEAD(&dev->napi_list);
10624 	INIT_LIST_HEAD(&dev->unreg_list);
10625 	INIT_LIST_HEAD(&dev->close_list);
10626 	INIT_LIST_HEAD(&dev->link_watch_list);
10627 	INIT_LIST_HEAD(&dev->adj_list.upper);
10628 	INIT_LIST_HEAD(&dev->adj_list.lower);
10629 	INIT_LIST_HEAD(&dev->ptype_all);
10630 	INIT_LIST_HEAD(&dev->ptype_specific);
10631 	INIT_LIST_HEAD(&dev->net_notifier_list);
10632 #ifdef CONFIG_NET_SCHED
10633 	hash_init(dev->qdisc_hash);
10634 #endif
10635 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10636 	setup(dev);
10637 
10638 	if (!dev->tx_queue_len) {
10639 		dev->priv_flags |= IFF_NO_QUEUE;
10640 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10641 	}
10642 
10643 	dev->num_tx_queues = txqs;
10644 	dev->real_num_tx_queues = txqs;
10645 	if (netif_alloc_netdev_queues(dev))
10646 		goto free_all;
10647 
10648 	dev->num_rx_queues = rxqs;
10649 	dev->real_num_rx_queues = rxqs;
10650 	if (netif_alloc_rx_queues(dev))
10651 		goto free_all;
10652 
10653 	strcpy(dev->name, name);
10654 	dev->name_assign_type = name_assign_type;
10655 	dev->group = INIT_NETDEV_GROUP;
10656 	if (!dev->ethtool_ops)
10657 		dev->ethtool_ops = &default_ethtool_ops;
10658 
10659 	nf_hook_netdev_init(dev);
10660 
10661 	return dev;
10662 
10663 free_all:
10664 	free_netdev(dev);
10665 	return NULL;
10666 
10667 free_pcpu:
10668 #ifdef CONFIG_PCPU_DEV_REFCNT
10669 	free_percpu(dev->pcpu_refcnt);
10670 free_dev:
10671 #endif
10672 	netdev_freemem(dev);
10673 	return NULL;
10674 }
10675 EXPORT_SYMBOL(alloc_netdev_mqs);
10676 
10677 /**
10678  * free_netdev - free network device
10679  * @dev: device
10680  *
10681  * This function does the last stage of destroying an allocated device
10682  * interface. The reference to the device object is released. If this
10683  * is the last reference then it will be freed.Must be called in process
10684  * context.
10685  */
10686 void free_netdev(struct net_device *dev)
10687 {
10688 	struct napi_struct *p, *n;
10689 
10690 	might_sleep();
10691 
10692 	/* When called immediately after register_netdevice() failed the unwind
10693 	 * handling may still be dismantling the device. Handle that case by
10694 	 * deferring the free.
10695 	 */
10696 	if (dev->reg_state == NETREG_UNREGISTERING) {
10697 		ASSERT_RTNL();
10698 		dev->needs_free_netdev = true;
10699 		return;
10700 	}
10701 
10702 	netif_free_tx_queues(dev);
10703 	netif_free_rx_queues(dev);
10704 
10705 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10706 
10707 	/* Flush device addresses */
10708 	dev_addr_flush(dev);
10709 
10710 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10711 		netif_napi_del(p);
10712 
10713 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10714 #ifdef CONFIG_PCPU_DEV_REFCNT
10715 	free_percpu(dev->pcpu_refcnt);
10716 	dev->pcpu_refcnt = NULL;
10717 #endif
10718 	free_percpu(dev->core_stats);
10719 	dev->core_stats = NULL;
10720 	free_percpu(dev->xdp_bulkq);
10721 	dev->xdp_bulkq = NULL;
10722 
10723 	/*  Compatibility with error handling in drivers */
10724 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10725 		netdev_freemem(dev);
10726 		return;
10727 	}
10728 
10729 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10730 	dev->reg_state = NETREG_RELEASED;
10731 
10732 	/* will free via device release */
10733 	put_device(&dev->dev);
10734 }
10735 EXPORT_SYMBOL(free_netdev);
10736 
10737 /**
10738  *	synchronize_net -  Synchronize with packet receive processing
10739  *
10740  *	Wait for packets currently being received to be done.
10741  *	Does not block later packets from starting.
10742  */
10743 void synchronize_net(void)
10744 {
10745 	might_sleep();
10746 	if (rtnl_is_locked())
10747 		synchronize_rcu_expedited();
10748 	else
10749 		synchronize_rcu();
10750 }
10751 EXPORT_SYMBOL(synchronize_net);
10752 
10753 /**
10754  *	unregister_netdevice_queue - remove device from the kernel
10755  *	@dev: device
10756  *	@head: list
10757  *
10758  *	This function shuts down a device interface and removes it
10759  *	from the kernel tables.
10760  *	If head not NULL, device is queued to be unregistered later.
10761  *
10762  *	Callers must hold the rtnl semaphore.  You may want
10763  *	unregister_netdev() instead of this.
10764  */
10765 
10766 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10767 {
10768 	ASSERT_RTNL();
10769 
10770 	if (head) {
10771 		list_move_tail(&dev->unreg_list, head);
10772 	} else {
10773 		LIST_HEAD(single);
10774 
10775 		list_add(&dev->unreg_list, &single);
10776 		unregister_netdevice_many(&single);
10777 	}
10778 }
10779 EXPORT_SYMBOL(unregister_netdevice_queue);
10780 
10781 void unregister_netdevice_many_notify(struct list_head *head,
10782 				      u32 portid, const struct nlmsghdr *nlh)
10783 {
10784 	struct net_device *dev, *tmp;
10785 	LIST_HEAD(close_head);
10786 
10787 	BUG_ON(dev_boot_phase);
10788 	ASSERT_RTNL();
10789 
10790 	if (list_empty(head))
10791 		return;
10792 
10793 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10794 		/* Some devices call without registering
10795 		 * for initialization unwind. Remove those
10796 		 * devices and proceed with the remaining.
10797 		 */
10798 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10799 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10800 				 dev->name, dev);
10801 
10802 			WARN_ON(1);
10803 			list_del(&dev->unreg_list);
10804 			continue;
10805 		}
10806 		dev->dismantle = true;
10807 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10808 	}
10809 
10810 	/* If device is running, close it first. */
10811 	list_for_each_entry(dev, head, unreg_list)
10812 		list_add_tail(&dev->close_list, &close_head);
10813 	dev_close_many(&close_head, true);
10814 
10815 	list_for_each_entry(dev, head, unreg_list) {
10816 		/* And unlink it from device chain. */
10817 		write_lock(&dev_base_lock);
10818 		unlist_netdevice(dev, false);
10819 		dev->reg_state = NETREG_UNREGISTERING;
10820 		write_unlock(&dev_base_lock);
10821 	}
10822 	flush_all_backlogs();
10823 
10824 	synchronize_net();
10825 
10826 	list_for_each_entry(dev, head, unreg_list) {
10827 		struct sk_buff *skb = NULL;
10828 
10829 		/* Shutdown queueing discipline. */
10830 		dev_shutdown(dev);
10831 
10832 		dev_xdp_uninstall(dev);
10833 
10834 		netdev_offload_xstats_disable_all(dev);
10835 
10836 		/* Notify protocols, that we are about to destroy
10837 		 * this device. They should clean all the things.
10838 		 */
10839 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10840 
10841 		if (!dev->rtnl_link_ops ||
10842 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10843 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10844 						     GFP_KERNEL, NULL, 0,
10845 						     portid, nlmsg_seq(nlh));
10846 
10847 		/*
10848 		 *	Flush the unicast and multicast chains
10849 		 */
10850 		dev_uc_flush(dev);
10851 		dev_mc_flush(dev);
10852 
10853 		netdev_name_node_alt_flush(dev);
10854 		netdev_name_node_free(dev->name_node);
10855 
10856 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10857 
10858 		if (dev->netdev_ops->ndo_uninit)
10859 			dev->netdev_ops->ndo_uninit(dev);
10860 
10861 		if (skb)
10862 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
10863 
10864 		/* Notifier chain MUST detach us all upper devices. */
10865 		WARN_ON(netdev_has_any_upper_dev(dev));
10866 		WARN_ON(netdev_has_any_lower_dev(dev));
10867 
10868 		/* Remove entries from kobject tree */
10869 		netdev_unregister_kobject(dev);
10870 #ifdef CONFIG_XPS
10871 		/* Remove XPS queueing entries */
10872 		netif_reset_xps_queues_gt(dev, 0);
10873 #endif
10874 	}
10875 
10876 	synchronize_net();
10877 
10878 	list_for_each_entry(dev, head, unreg_list) {
10879 		netdev_put(dev, &dev->dev_registered_tracker);
10880 		net_set_todo(dev);
10881 	}
10882 
10883 	list_del(head);
10884 }
10885 
10886 /**
10887  *	unregister_netdevice_many - unregister many devices
10888  *	@head: list of devices
10889  *
10890  *  Note: As most callers use a stack allocated list_head,
10891  *  we force a list_del() to make sure stack wont be corrupted later.
10892  */
10893 void unregister_netdevice_many(struct list_head *head)
10894 {
10895 	unregister_netdevice_many_notify(head, 0, NULL);
10896 }
10897 EXPORT_SYMBOL(unregister_netdevice_many);
10898 
10899 /**
10900  *	unregister_netdev - remove device from the kernel
10901  *	@dev: device
10902  *
10903  *	This function shuts down a device interface and removes it
10904  *	from the kernel tables.
10905  *
10906  *	This is just a wrapper for unregister_netdevice that takes
10907  *	the rtnl semaphore.  In general you want to use this and not
10908  *	unregister_netdevice.
10909  */
10910 void unregister_netdev(struct net_device *dev)
10911 {
10912 	rtnl_lock();
10913 	unregister_netdevice(dev);
10914 	rtnl_unlock();
10915 }
10916 EXPORT_SYMBOL(unregister_netdev);
10917 
10918 /**
10919  *	__dev_change_net_namespace - move device to different nethost namespace
10920  *	@dev: device
10921  *	@net: network namespace
10922  *	@pat: If not NULL name pattern to try if the current device name
10923  *	      is already taken in the destination network namespace.
10924  *	@new_ifindex: If not zero, specifies device index in the target
10925  *	              namespace.
10926  *
10927  *	This function shuts down a device interface and moves it
10928  *	to a new network namespace. On success 0 is returned, on
10929  *	a failure a netagive errno code is returned.
10930  *
10931  *	Callers must hold the rtnl semaphore.
10932  */
10933 
10934 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10935 			       const char *pat, int new_ifindex)
10936 {
10937 	struct net *net_old = dev_net(dev);
10938 	int err, new_nsid;
10939 
10940 	ASSERT_RTNL();
10941 
10942 	/* Don't allow namespace local devices to be moved. */
10943 	err = -EINVAL;
10944 	if (dev->features & NETIF_F_NETNS_LOCAL)
10945 		goto out;
10946 
10947 	/* Ensure the device has been registrered */
10948 	if (dev->reg_state != NETREG_REGISTERED)
10949 		goto out;
10950 
10951 	/* Get out if there is nothing todo */
10952 	err = 0;
10953 	if (net_eq(net_old, net))
10954 		goto out;
10955 
10956 	/* Pick the destination device name, and ensure
10957 	 * we can use it in the destination network namespace.
10958 	 */
10959 	err = -EEXIST;
10960 	if (netdev_name_in_use(net, dev->name)) {
10961 		/* We get here if we can't use the current device name */
10962 		if (!pat)
10963 			goto out;
10964 		err = dev_get_valid_name(net, dev, pat);
10965 		if (err < 0)
10966 			goto out;
10967 	}
10968 
10969 	/* Check that new_ifindex isn't used yet. */
10970 	err = -EBUSY;
10971 	if (new_ifindex && __dev_get_by_index(net, new_ifindex))
10972 		goto out;
10973 
10974 	/*
10975 	 * And now a mini version of register_netdevice unregister_netdevice.
10976 	 */
10977 
10978 	/* If device is running close it first. */
10979 	dev_close(dev);
10980 
10981 	/* And unlink it from device chain */
10982 	unlist_netdevice(dev, true);
10983 
10984 	synchronize_net();
10985 
10986 	/* Shutdown queueing discipline. */
10987 	dev_shutdown(dev);
10988 
10989 	/* Notify protocols, that we are about to destroy
10990 	 * this device. They should clean all the things.
10991 	 *
10992 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
10993 	 * This is wanted because this way 8021q and macvlan know
10994 	 * the device is just moving and can keep their slaves up.
10995 	 */
10996 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10997 	rcu_barrier();
10998 
10999 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11000 	/* If there is an ifindex conflict assign a new one */
11001 	if (!new_ifindex) {
11002 		if (__dev_get_by_index(net, dev->ifindex))
11003 			new_ifindex = dev_new_index(net);
11004 		else
11005 			new_ifindex = dev->ifindex;
11006 	}
11007 
11008 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11009 			    new_ifindex);
11010 
11011 	/*
11012 	 *	Flush the unicast and multicast chains
11013 	 */
11014 	dev_uc_flush(dev);
11015 	dev_mc_flush(dev);
11016 
11017 	/* Send a netdev-removed uevent to the old namespace */
11018 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11019 	netdev_adjacent_del_links(dev);
11020 
11021 	/* Move per-net netdevice notifiers that are following the netdevice */
11022 	move_netdevice_notifiers_dev_net(dev, net);
11023 
11024 	/* Actually switch the network namespace */
11025 	dev_net_set(dev, net);
11026 	dev->ifindex = new_ifindex;
11027 
11028 	/* Send a netdev-add uevent to the new namespace */
11029 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11030 	netdev_adjacent_add_links(dev);
11031 
11032 	/* Fixup kobjects */
11033 	err = device_rename(&dev->dev, dev->name);
11034 	WARN_ON(err);
11035 
11036 	/* Adapt owner in case owning user namespace of target network
11037 	 * namespace is different from the original one.
11038 	 */
11039 	err = netdev_change_owner(dev, net_old, net);
11040 	WARN_ON(err);
11041 
11042 	/* Add the device back in the hashes */
11043 	list_netdevice(dev);
11044 
11045 	/* Notify protocols, that a new device appeared. */
11046 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11047 
11048 	/*
11049 	 *	Prevent userspace races by waiting until the network
11050 	 *	device is fully setup before sending notifications.
11051 	 */
11052 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11053 
11054 	synchronize_net();
11055 	err = 0;
11056 out:
11057 	return err;
11058 }
11059 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11060 
11061 static int dev_cpu_dead(unsigned int oldcpu)
11062 {
11063 	struct sk_buff **list_skb;
11064 	struct sk_buff *skb;
11065 	unsigned int cpu;
11066 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11067 
11068 	local_irq_disable();
11069 	cpu = smp_processor_id();
11070 	sd = &per_cpu(softnet_data, cpu);
11071 	oldsd = &per_cpu(softnet_data, oldcpu);
11072 
11073 	/* Find end of our completion_queue. */
11074 	list_skb = &sd->completion_queue;
11075 	while (*list_skb)
11076 		list_skb = &(*list_skb)->next;
11077 	/* Append completion queue from offline CPU. */
11078 	*list_skb = oldsd->completion_queue;
11079 	oldsd->completion_queue = NULL;
11080 
11081 	/* Append output queue from offline CPU. */
11082 	if (oldsd->output_queue) {
11083 		*sd->output_queue_tailp = oldsd->output_queue;
11084 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11085 		oldsd->output_queue = NULL;
11086 		oldsd->output_queue_tailp = &oldsd->output_queue;
11087 	}
11088 	/* Append NAPI poll list from offline CPU, with one exception :
11089 	 * process_backlog() must be called by cpu owning percpu backlog.
11090 	 * We properly handle process_queue & input_pkt_queue later.
11091 	 */
11092 	while (!list_empty(&oldsd->poll_list)) {
11093 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11094 							    struct napi_struct,
11095 							    poll_list);
11096 
11097 		list_del_init(&napi->poll_list);
11098 		if (napi->poll == process_backlog)
11099 			napi->state = 0;
11100 		else
11101 			____napi_schedule(sd, napi);
11102 	}
11103 
11104 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11105 	local_irq_enable();
11106 
11107 #ifdef CONFIG_RPS
11108 	remsd = oldsd->rps_ipi_list;
11109 	oldsd->rps_ipi_list = NULL;
11110 #endif
11111 	/* send out pending IPI's on offline CPU */
11112 	net_rps_send_ipi(remsd);
11113 
11114 	/* Process offline CPU's input_pkt_queue */
11115 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11116 		netif_rx(skb);
11117 		input_queue_head_incr(oldsd);
11118 	}
11119 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11120 		netif_rx(skb);
11121 		input_queue_head_incr(oldsd);
11122 	}
11123 
11124 	return 0;
11125 }
11126 
11127 /**
11128  *	netdev_increment_features - increment feature set by one
11129  *	@all: current feature set
11130  *	@one: new feature set
11131  *	@mask: mask feature set
11132  *
11133  *	Computes a new feature set after adding a device with feature set
11134  *	@one to the master device with current feature set @all.  Will not
11135  *	enable anything that is off in @mask. Returns the new feature set.
11136  */
11137 netdev_features_t netdev_increment_features(netdev_features_t all,
11138 	netdev_features_t one, netdev_features_t mask)
11139 {
11140 	if (mask & NETIF_F_HW_CSUM)
11141 		mask |= NETIF_F_CSUM_MASK;
11142 	mask |= NETIF_F_VLAN_CHALLENGED;
11143 
11144 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11145 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11146 
11147 	/* If one device supports hw checksumming, set for all. */
11148 	if (all & NETIF_F_HW_CSUM)
11149 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11150 
11151 	return all;
11152 }
11153 EXPORT_SYMBOL(netdev_increment_features);
11154 
11155 static struct hlist_head * __net_init netdev_create_hash(void)
11156 {
11157 	int i;
11158 	struct hlist_head *hash;
11159 
11160 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11161 	if (hash != NULL)
11162 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11163 			INIT_HLIST_HEAD(&hash[i]);
11164 
11165 	return hash;
11166 }
11167 
11168 /* Initialize per network namespace state */
11169 static int __net_init netdev_init(struct net *net)
11170 {
11171 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11172 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11173 
11174 	INIT_LIST_HEAD(&net->dev_base_head);
11175 
11176 	net->dev_name_head = netdev_create_hash();
11177 	if (net->dev_name_head == NULL)
11178 		goto err_name;
11179 
11180 	net->dev_index_head = netdev_create_hash();
11181 	if (net->dev_index_head == NULL)
11182 		goto err_idx;
11183 
11184 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11185 
11186 	return 0;
11187 
11188 err_idx:
11189 	kfree(net->dev_name_head);
11190 err_name:
11191 	return -ENOMEM;
11192 }
11193 
11194 /**
11195  *	netdev_drivername - network driver for the device
11196  *	@dev: network device
11197  *
11198  *	Determine network driver for device.
11199  */
11200 const char *netdev_drivername(const struct net_device *dev)
11201 {
11202 	const struct device_driver *driver;
11203 	const struct device *parent;
11204 	const char *empty = "";
11205 
11206 	parent = dev->dev.parent;
11207 	if (!parent)
11208 		return empty;
11209 
11210 	driver = parent->driver;
11211 	if (driver && driver->name)
11212 		return driver->name;
11213 	return empty;
11214 }
11215 
11216 static void __netdev_printk(const char *level, const struct net_device *dev,
11217 			    struct va_format *vaf)
11218 {
11219 	if (dev && dev->dev.parent) {
11220 		dev_printk_emit(level[1] - '0',
11221 				dev->dev.parent,
11222 				"%s %s %s%s: %pV",
11223 				dev_driver_string(dev->dev.parent),
11224 				dev_name(dev->dev.parent),
11225 				netdev_name(dev), netdev_reg_state(dev),
11226 				vaf);
11227 	} else if (dev) {
11228 		printk("%s%s%s: %pV",
11229 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11230 	} else {
11231 		printk("%s(NULL net_device): %pV", level, vaf);
11232 	}
11233 }
11234 
11235 void netdev_printk(const char *level, const struct net_device *dev,
11236 		   const char *format, ...)
11237 {
11238 	struct va_format vaf;
11239 	va_list args;
11240 
11241 	va_start(args, format);
11242 
11243 	vaf.fmt = format;
11244 	vaf.va = &args;
11245 
11246 	__netdev_printk(level, dev, &vaf);
11247 
11248 	va_end(args);
11249 }
11250 EXPORT_SYMBOL(netdev_printk);
11251 
11252 #define define_netdev_printk_level(func, level)			\
11253 void func(const struct net_device *dev, const char *fmt, ...)	\
11254 {								\
11255 	struct va_format vaf;					\
11256 	va_list args;						\
11257 								\
11258 	va_start(args, fmt);					\
11259 								\
11260 	vaf.fmt = fmt;						\
11261 	vaf.va = &args;						\
11262 								\
11263 	__netdev_printk(level, dev, &vaf);			\
11264 								\
11265 	va_end(args);						\
11266 }								\
11267 EXPORT_SYMBOL(func);
11268 
11269 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11270 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11271 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11272 define_netdev_printk_level(netdev_err, KERN_ERR);
11273 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11274 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11275 define_netdev_printk_level(netdev_info, KERN_INFO);
11276 
11277 static void __net_exit netdev_exit(struct net *net)
11278 {
11279 	kfree(net->dev_name_head);
11280 	kfree(net->dev_index_head);
11281 	if (net != &init_net)
11282 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11283 }
11284 
11285 static struct pernet_operations __net_initdata netdev_net_ops = {
11286 	.init = netdev_init,
11287 	.exit = netdev_exit,
11288 };
11289 
11290 static void __net_exit default_device_exit_net(struct net *net)
11291 {
11292 	struct net_device *dev, *aux;
11293 	/*
11294 	 * Push all migratable network devices back to the
11295 	 * initial network namespace
11296 	 */
11297 	ASSERT_RTNL();
11298 	for_each_netdev_safe(net, dev, aux) {
11299 		int err;
11300 		char fb_name[IFNAMSIZ];
11301 
11302 		/* Ignore unmoveable devices (i.e. loopback) */
11303 		if (dev->features & NETIF_F_NETNS_LOCAL)
11304 			continue;
11305 
11306 		/* Leave virtual devices for the generic cleanup */
11307 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11308 			continue;
11309 
11310 		/* Push remaining network devices to init_net */
11311 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11312 		if (netdev_name_in_use(&init_net, fb_name))
11313 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11314 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11315 		if (err) {
11316 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11317 				 __func__, dev->name, err);
11318 			BUG();
11319 		}
11320 	}
11321 }
11322 
11323 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11324 {
11325 	/* At exit all network devices most be removed from a network
11326 	 * namespace.  Do this in the reverse order of registration.
11327 	 * Do this across as many network namespaces as possible to
11328 	 * improve batching efficiency.
11329 	 */
11330 	struct net_device *dev;
11331 	struct net *net;
11332 	LIST_HEAD(dev_kill_list);
11333 
11334 	rtnl_lock();
11335 	list_for_each_entry(net, net_list, exit_list) {
11336 		default_device_exit_net(net);
11337 		cond_resched();
11338 	}
11339 
11340 	list_for_each_entry(net, net_list, exit_list) {
11341 		for_each_netdev_reverse(net, dev) {
11342 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11343 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11344 			else
11345 				unregister_netdevice_queue(dev, &dev_kill_list);
11346 		}
11347 	}
11348 	unregister_netdevice_many(&dev_kill_list);
11349 	rtnl_unlock();
11350 }
11351 
11352 static struct pernet_operations __net_initdata default_device_ops = {
11353 	.exit_batch = default_device_exit_batch,
11354 };
11355 
11356 /*
11357  *	Initialize the DEV module. At boot time this walks the device list and
11358  *	unhooks any devices that fail to initialise (normally hardware not
11359  *	present) and leaves us with a valid list of present and active devices.
11360  *
11361  */
11362 
11363 /*
11364  *       This is called single threaded during boot, so no need
11365  *       to take the rtnl semaphore.
11366  */
11367 static int __init net_dev_init(void)
11368 {
11369 	int i, rc = -ENOMEM;
11370 
11371 	BUG_ON(!dev_boot_phase);
11372 
11373 	if (dev_proc_init())
11374 		goto out;
11375 
11376 	if (netdev_kobject_init())
11377 		goto out;
11378 
11379 	INIT_LIST_HEAD(&ptype_all);
11380 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11381 		INIT_LIST_HEAD(&ptype_base[i]);
11382 
11383 	if (register_pernet_subsys(&netdev_net_ops))
11384 		goto out;
11385 
11386 	/*
11387 	 *	Initialise the packet receive queues.
11388 	 */
11389 
11390 	for_each_possible_cpu(i) {
11391 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11392 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11393 
11394 		INIT_WORK(flush, flush_backlog);
11395 
11396 		skb_queue_head_init(&sd->input_pkt_queue);
11397 		skb_queue_head_init(&sd->process_queue);
11398 #ifdef CONFIG_XFRM_OFFLOAD
11399 		skb_queue_head_init(&sd->xfrm_backlog);
11400 #endif
11401 		INIT_LIST_HEAD(&sd->poll_list);
11402 		sd->output_queue_tailp = &sd->output_queue;
11403 #ifdef CONFIG_RPS
11404 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11405 		sd->cpu = i;
11406 #endif
11407 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11408 		spin_lock_init(&sd->defer_lock);
11409 
11410 		init_gro_hash(&sd->backlog);
11411 		sd->backlog.poll = process_backlog;
11412 		sd->backlog.weight = weight_p;
11413 	}
11414 
11415 	dev_boot_phase = 0;
11416 
11417 	/* The loopback device is special if any other network devices
11418 	 * is present in a network namespace the loopback device must
11419 	 * be present. Since we now dynamically allocate and free the
11420 	 * loopback device ensure this invariant is maintained by
11421 	 * keeping the loopback device as the first device on the
11422 	 * list of network devices.  Ensuring the loopback devices
11423 	 * is the first device that appears and the last network device
11424 	 * that disappears.
11425 	 */
11426 	if (register_pernet_device(&loopback_net_ops))
11427 		goto out;
11428 
11429 	if (register_pernet_device(&default_device_ops))
11430 		goto out;
11431 
11432 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11433 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11434 
11435 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11436 				       NULL, dev_cpu_dead);
11437 	WARN_ON(rc < 0);
11438 	rc = 0;
11439 out:
11440 	return rc;
11441 }
11442 
11443 subsys_initcall(net_dev_init);
11444