xref: /linux/net/core/dev.c (revision 15f93f46f31232da863316769182c699e364c45f)
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_extack(unsigned long val,
164 					   struct net_device *dev,
165 					   struct netlink_ext_ack *extack);
166 static struct napi_struct *napi_by_id(unsigned int napi_id);
167 
168 /*
169  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
170  * semaphore.
171  *
172  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
173  *
174  * Writers must hold the rtnl semaphore while they loop through the
175  * dev_base_head list, and hold dev_base_lock for writing when they do the
176  * actual updates.  This allows pure readers to access the list even
177  * while a writer is preparing to update it.
178  *
179  * To put it another way, dev_base_lock is held for writing only to
180  * protect against pure readers; the rtnl semaphore provides the
181  * protection against other writers.
182  *
183  * See, for example usages, register_netdevice() and
184  * unregister_netdevice(), which must be called with the rtnl
185  * semaphore held.
186  */
187 DEFINE_RWLOCK(dev_base_lock);
188 EXPORT_SYMBOL(dev_base_lock);
189 
190 static DEFINE_MUTEX(ifalias_mutex);
191 
192 /* protects napi_hash addition/deletion and napi_gen_id */
193 static DEFINE_SPINLOCK(napi_hash_lock);
194 
195 static unsigned int napi_gen_id = NR_CPUS;
196 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
197 
198 static DECLARE_RWSEM(devnet_rename_sem);
199 
200 static inline void dev_base_seq_inc(struct net *net)
201 {
202 	while (++net->dev_base_seq == 0)
203 		;
204 }
205 
206 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
207 {
208 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
209 
210 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
211 }
212 
213 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
214 {
215 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
216 }
217 
218 static inline void rps_lock_irqsave(struct softnet_data *sd,
219 				    unsigned long *flags)
220 {
221 	if (IS_ENABLED(CONFIG_RPS))
222 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
223 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
224 		local_irq_save(*flags);
225 }
226 
227 static inline void rps_lock_irq_disable(struct softnet_data *sd)
228 {
229 	if (IS_ENABLED(CONFIG_RPS))
230 		spin_lock_irq(&sd->input_pkt_queue.lock);
231 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
232 		local_irq_disable();
233 }
234 
235 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
236 					  unsigned long *flags)
237 {
238 	if (IS_ENABLED(CONFIG_RPS))
239 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
240 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
241 		local_irq_restore(*flags);
242 }
243 
244 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
245 {
246 	if (IS_ENABLED(CONFIG_RPS))
247 		spin_unlock_irq(&sd->input_pkt_queue.lock);
248 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
249 		local_irq_enable();
250 }
251 
252 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
253 						       const char *name)
254 {
255 	struct netdev_name_node *name_node;
256 
257 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
258 	if (!name_node)
259 		return NULL;
260 	INIT_HLIST_NODE(&name_node->hlist);
261 	name_node->dev = dev;
262 	name_node->name = name;
263 	return name_node;
264 }
265 
266 static struct netdev_name_node *
267 netdev_name_node_head_alloc(struct net_device *dev)
268 {
269 	struct netdev_name_node *name_node;
270 
271 	name_node = netdev_name_node_alloc(dev, dev->name);
272 	if (!name_node)
273 		return NULL;
274 	INIT_LIST_HEAD(&name_node->list);
275 	return name_node;
276 }
277 
278 static void netdev_name_node_free(struct netdev_name_node *name_node)
279 {
280 	kfree(name_node);
281 }
282 
283 static void netdev_name_node_add(struct net *net,
284 				 struct netdev_name_node *name_node)
285 {
286 	hlist_add_head_rcu(&name_node->hlist,
287 			   dev_name_hash(net, name_node->name));
288 }
289 
290 static void netdev_name_node_del(struct netdev_name_node *name_node)
291 {
292 	hlist_del_rcu(&name_node->hlist);
293 }
294 
295 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
296 							const char *name)
297 {
298 	struct hlist_head *head = dev_name_hash(net, name);
299 	struct netdev_name_node *name_node;
300 
301 	hlist_for_each_entry(name_node, head, hlist)
302 		if (!strcmp(name_node->name, name))
303 			return name_node;
304 	return NULL;
305 }
306 
307 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
308 							    const char *name)
309 {
310 	struct hlist_head *head = dev_name_hash(net, name);
311 	struct netdev_name_node *name_node;
312 
313 	hlist_for_each_entry_rcu(name_node, head, hlist)
314 		if (!strcmp(name_node->name, name))
315 			return name_node;
316 	return NULL;
317 }
318 
319 bool netdev_name_in_use(struct net *net, const char *name)
320 {
321 	return netdev_name_node_lookup(net, name);
322 }
323 EXPORT_SYMBOL(netdev_name_in_use);
324 
325 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
326 {
327 	struct netdev_name_node *name_node;
328 	struct net *net = dev_net(dev);
329 
330 	name_node = netdev_name_node_lookup(net, name);
331 	if (name_node)
332 		return -EEXIST;
333 	name_node = netdev_name_node_alloc(dev, name);
334 	if (!name_node)
335 		return -ENOMEM;
336 	netdev_name_node_add(net, name_node);
337 	/* The node that holds dev->name acts as a head of per-device list. */
338 	list_add_tail(&name_node->list, &dev->name_node->list);
339 
340 	return 0;
341 }
342 
343 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
344 {
345 	list_del(&name_node->list);
346 	netdev_name_node_del(name_node);
347 	kfree(name_node->name);
348 	netdev_name_node_free(name_node);
349 }
350 
351 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
352 {
353 	struct netdev_name_node *name_node;
354 	struct net *net = dev_net(dev);
355 
356 	name_node = netdev_name_node_lookup(net, name);
357 	if (!name_node)
358 		return -ENOENT;
359 	/* lookup might have found our primary name or a name belonging
360 	 * to another device.
361 	 */
362 	if (name_node == dev->name_node || name_node->dev != dev)
363 		return -EINVAL;
364 
365 	__netdev_name_node_alt_destroy(name_node);
366 
367 	return 0;
368 }
369 
370 static void netdev_name_node_alt_flush(struct net_device *dev)
371 {
372 	struct netdev_name_node *name_node, *tmp;
373 
374 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
375 		__netdev_name_node_alt_destroy(name_node);
376 }
377 
378 /* Device list insertion */
379 static void list_netdevice(struct net_device *dev)
380 {
381 	struct net *net = dev_net(dev);
382 
383 	ASSERT_RTNL();
384 
385 	write_lock(&dev_base_lock);
386 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
387 	netdev_name_node_add(net, dev->name_node);
388 	hlist_add_head_rcu(&dev->index_hlist,
389 			   dev_index_hash(net, dev->ifindex));
390 	write_unlock(&dev_base_lock);
391 
392 	dev_base_seq_inc(net);
393 }
394 
395 /* Device list removal
396  * caller must respect a RCU grace period before freeing/reusing dev
397  */
398 static void unlist_netdevice(struct net_device *dev, bool lock)
399 {
400 	ASSERT_RTNL();
401 
402 	/* Unlink dev from the device chain */
403 	if (lock)
404 		write_lock(&dev_base_lock);
405 	list_del_rcu(&dev->dev_list);
406 	netdev_name_node_del(dev->name_node);
407 	hlist_del_rcu(&dev->index_hlist);
408 	if (lock)
409 		write_unlock(&dev_base_lock);
410 
411 	dev_base_seq_inc(dev_net(dev));
412 }
413 
414 /*
415  *	Our notifier list
416  */
417 
418 static RAW_NOTIFIER_HEAD(netdev_chain);
419 
420 /*
421  *	Device drivers call our routines to queue packets here. We empty the
422  *	queue in the local softnet handler.
423  */
424 
425 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
426 EXPORT_PER_CPU_SYMBOL(softnet_data);
427 
428 #ifdef CONFIG_LOCKDEP
429 /*
430  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
431  * according to dev->type
432  */
433 static const unsigned short netdev_lock_type[] = {
434 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
435 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
436 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
437 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
438 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
439 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
440 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
441 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
442 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
443 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
444 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
445 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
446 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
447 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
448 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
449 
450 static const char *const netdev_lock_name[] = {
451 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
452 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
453 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
454 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
455 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
456 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
457 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
458 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
459 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
460 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
461 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
462 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
463 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
464 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
465 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
466 
467 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
468 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
469 
470 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
471 {
472 	int i;
473 
474 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
475 		if (netdev_lock_type[i] == dev_type)
476 			return i;
477 	/* the last key is used by default */
478 	return ARRAY_SIZE(netdev_lock_type) - 1;
479 }
480 
481 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
482 						 unsigned short dev_type)
483 {
484 	int i;
485 
486 	i = netdev_lock_pos(dev_type);
487 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
488 				   netdev_lock_name[i]);
489 }
490 
491 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
492 {
493 	int i;
494 
495 	i = netdev_lock_pos(dev->type);
496 	lockdep_set_class_and_name(&dev->addr_list_lock,
497 				   &netdev_addr_lock_key[i],
498 				   netdev_lock_name[i]);
499 }
500 #else
501 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
502 						 unsigned short dev_type)
503 {
504 }
505 
506 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
507 {
508 }
509 #endif
510 
511 /*******************************************************************************
512  *
513  *		Protocol management and registration routines
514  *
515  *******************************************************************************/
516 
517 
518 /*
519  *	Add a protocol ID to the list. Now that the input handler is
520  *	smarter we can dispense with all the messy stuff that used to be
521  *	here.
522  *
523  *	BEWARE!!! Protocol handlers, mangling input packets,
524  *	MUST BE last in hash buckets and checking protocol handlers
525  *	MUST start from promiscuous ptype_all chain in net_bh.
526  *	It is true now, do not change it.
527  *	Explanation follows: if protocol handler, mangling packet, will
528  *	be the first on list, it is not able to sense, that packet
529  *	is cloned and should be copied-on-write, so that it will
530  *	change it and subsequent readers will get broken packet.
531  *							--ANK (980803)
532  */
533 
534 static inline struct list_head *ptype_head(const struct packet_type *pt)
535 {
536 	if (pt->type == htons(ETH_P_ALL))
537 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
538 	else
539 		return pt->dev ? &pt->dev->ptype_specific :
540 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
541 }
542 
543 /**
544  *	dev_add_pack - add packet handler
545  *	@pt: packet type declaration
546  *
547  *	Add a protocol handler to the networking stack. The passed &packet_type
548  *	is linked into kernel lists and may not be freed until it has been
549  *	removed from the kernel lists.
550  *
551  *	This call does not sleep therefore it can not
552  *	guarantee all CPU's that are in middle of receiving packets
553  *	will see the new packet type (until the next received packet).
554  */
555 
556 void dev_add_pack(struct packet_type *pt)
557 {
558 	struct list_head *head = ptype_head(pt);
559 
560 	spin_lock(&ptype_lock);
561 	list_add_rcu(&pt->list, head);
562 	spin_unlock(&ptype_lock);
563 }
564 EXPORT_SYMBOL(dev_add_pack);
565 
566 /**
567  *	__dev_remove_pack	 - remove packet handler
568  *	@pt: packet type declaration
569  *
570  *	Remove a protocol handler that was previously added to the kernel
571  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
572  *	from the kernel lists and can be freed or reused once this function
573  *	returns.
574  *
575  *      The packet type might still be in use by receivers
576  *	and must not be freed until after all the CPU's have gone
577  *	through a quiescent state.
578  */
579 void __dev_remove_pack(struct packet_type *pt)
580 {
581 	struct list_head *head = ptype_head(pt);
582 	struct packet_type *pt1;
583 
584 	spin_lock(&ptype_lock);
585 
586 	list_for_each_entry(pt1, head, list) {
587 		if (pt == pt1) {
588 			list_del_rcu(&pt->list);
589 			goto out;
590 		}
591 	}
592 
593 	pr_warn("dev_remove_pack: %p not found\n", pt);
594 out:
595 	spin_unlock(&ptype_lock);
596 }
597 EXPORT_SYMBOL(__dev_remove_pack);
598 
599 /**
600  *	dev_remove_pack	 - remove packet handler
601  *	@pt: packet type declaration
602  *
603  *	Remove a protocol handler that was previously added to the kernel
604  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
605  *	from the kernel lists and can be freed or reused once this function
606  *	returns.
607  *
608  *	This call sleeps to guarantee that no CPU is looking at the packet
609  *	type after return.
610  */
611 void dev_remove_pack(struct packet_type *pt)
612 {
613 	__dev_remove_pack(pt);
614 
615 	synchronize_net();
616 }
617 EXPORT_SYMBOL(dev_remove_pack);
618 
619 
620 /*******************************************************************************
621  *
622  *			    Device Interface Subroutines
623  *
624  *******************************************************************************/
625 
626 /**
627  *	dev_get_iflink	- get 'iflink' value of a interface
628  *	@dev: targeted interface
629  *
630  *	Indicates the ifindex the interface is linked to.
631  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
632  */
633 
634 int dev_get_iflink(const struct net_device *dev)
635 {
636 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
637 		return dev->netdev_ops->ndo_get_iflink(dev);
638 
639 	return dev->ifindex;
640 }
641 EXPORT_SYMBOL(dev_get_iflink);
642 
643 /**
644  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
645  *	@dev: targeted interface
646  *	@skb: The packet.
647  *
648  *	For better visibility of tunnel traffic OVS needs to retrieve
649  *	egress tunnel information for a packet. Following API allows
650  *	user to get this info.
651  */
652 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
653 {
654 	struct ip_tunnel_info *info;
655 
656 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
657 		return -EINVAL;
658 
659 	info = skb_tunnel_info_unclone(skb);
660 	if (!info)
661 		return -ENOMEM;
662 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
663 		return -EINVAL;
664 
665 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
666 }
667 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
668 
669 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
670 {
671 	int k = stack->num_paths++;
672 
673 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
674 		return NULL;
675 
676 	return &stack->path[k];
677 }
678 
679 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
680 			  struct net_device_path_stack *stack)
681 {
682 	const struct net_device *last_dev;
683 	struct net_device_path_ctx ctx = {
684 		.dev	= dev,
685 	};
686 	struct net_device_path *path;
687 	int ret = 0;
688 
689 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
690 	stack->num_paths = 0;
691 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
692 		last_dev = ctx.dev;
693 		path = dev_fwd_path(stack);
694 		if (!path)
695 			return -1;
696 
697 		memset(path, 0, sizeof(struct net_device_path));
698 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
699 		if (ret < 0)
700 			return -1;
701 
702 		if (WARN_ON_ONCE(last_dev == ctx.dev))
703 			return -1;
704 	}
705 
706 	if (!ctx.dev)
707 		return ret;
708 
709 	path = dev_fwd_path(stack);
710 	if (!path)
711 		return -1;
712 	path->type = DEV_PATH_ETHERNET;
713 	path->dev = ctx.dev;
714 
715 	return ret;
716 }
717 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
718 
719 /**
720  *	__dev_get_by_name	- find a device by its name
721  *	@net: the applicable net namespace
722  *	@name: name to find
723  *
724  *	Find an interface by name. Must be called under RTNL semaphore
725  *	or @dev_base_lock. If the name is found a pointer to the device
726  *	is returned. If the name is not found then %NULL is returned. The
727  *	reference counters are not incremented so the caller must be
728  *	careful with locks.
729  */
730 
731 struct net_device *__dev_get_by_name(struct net *net, const char *name)
732 {
733 	struct netdev_name_node *node_name;
734 
735 	node_name = netdev_name_node_lookup(net, name);
736 	return node_name ? node_name->dev : NULL;
737 }
738 EXPORT_SYMBOL(__dev_get_by_name);
739 
740 /**
741  * dev_get_by_name_rcu	- find a device by its name
742  * @net: the applicable net namespace
743  * @name: name to find
744  *
745  * Find an interface by name.
746  * If the name is found a pointer to the device is returned.
747  * If the name is not found then %NULL is returned.
748  * The reference counters are not incremented so the caller must be
749  * careful with locks. The caller must hold RCU lock.
750  */
751 
752 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
753 {
754 	struct netdev_name_node *node_name;
755 
756 	node_name = netdev_name_node_lookup_rcu(net, name);
757 	return node_name ? node_name->dev : NULL;
758 }
759 EXPORT_SYMBOL(dev_get_by_name_rcu);
760 
761 /**
762  *	dev_get_by_name		- find a device by its name
763  *	@net: the applicable net namespace
764  *	@name: name to find
765  *
766  *	Find an interface by name. This can be called from any
767  *	context and does its own locking. The returned handle has
768  *	the usage count incremented and the caller must use dev_put() to
769  *	release it when it is no longer needed. %NULL is returned if no
770  *	matching device is found.
771  */
772 
773 struct net_device *dev_get_by_name(struct net *net, const char *name)
774 {
775 	struct net_device *dev;
776 
777 	rcu_read_lock();
778 	dev = dev_get_by_name_rcu(net, name);
779 	dev_hold(dev);
780 	rcu_read_unlock();
781 	return dev;
782 }
783 EXPORT_SYMBOL(dev_get_by_name);
784 
785 /**
786  *	__dev_get_by_index - find a device by its ifindex
787  *	@net: the applicable net namespace
788  *	@ifindex: index of device
789  *
790  *	Search for an interface by index. Returns %NULL if the device
791  *	is not found or a pointer to the device. The device has not
792  *	had its reference counter increased so the caller must be careful
793  *	about locking. The caller must hold either the RTNL semaphore
794  *	or @dev_base_lock.
795  */
796 
797 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
798 {
799 	struct net_device *dev;
800 	struct hlist_head *head = dev_index_hash(net, ifindex);
801 
802 	hlist_for_each_entry(dev, head, index_hlist)
803 		if (dev->ifindex == ifindex)
804 			return dev;
805 
806 	return NULL;
807 }
808 EXPORT_SYMBOL(__dev_get_by_index);
809 
810 /**
811  *	dev_get_by_index_rcu - find a device by its ifindex
812  *	@net: the applicable net namespace
813  *	@ifindex: index of device
814  *
815  *	Search for an interface by index. Returns %NULL if the device
816  *	is not found or a pointer to the device. The device has not
817  *	had its reference counter increased so the caller must be careful
818  *	about locking. The caller must hold RCU lock.
819  */
820 
821 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
822 {
823 	struct net_device *dev;
824 	struct hlist_head *head = dev_index_hash(net, ifindex);
825 
826 	hlist_for_each_entry_rcu(dev, head, index_hlist)
827 		if (dev->ifindex == ifindex)
828 			return dev;
829 
830 	return NULL;
831 }
832 EXPORT_SYMBOL(dev_get_by_index_rcu);
833 
834 
835 /**
836  *	dev_get_by_index - find a device by its ifindex
837  *	@net: the applicable net namespace
838  *	@ifindex: index of device
839  *
840  *	Search for an interface by index. Returns NULL if the device
841  *	is not found or a pointer to the device. The device returned has
842  *	had a reference added and the pointer is safe until the user calls
843  *	dev_put to indicate they have finished with it.
844  */
845 
846 struct net_device *dev_get_by_index(struct net *net, int ifindex)
847 {
848 	struct net_device *dev;
849 
850 	rcu_read_lock();
851 	dev = dev_get_by_index_rcu(net, ifindex);
852 	dev_hold(dev);
853 	rcu_read_unlock();
854 	return dev;
855 }
856 EXPORT_SYMBOL(dev_get_by_index);
857 
858 /**
859  *	dev_get_by_napi_id - find a device by napi_id
860  *	@napi_id: ID of the NAPI struct
861  *
862  *	Search for an interface by NAPI ID. Returns %NULL if the device
863  *	is not found or a pointer to the device. The device has not had
864  *	its reference counter increased so the caller must be careful
865  *	about locking. The caller must hold RCU lock.
866  */
867 
868 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
869 {
870 	struct napi_struct *napi;
871 
872 	WARN_ON_ONCE(!rcu_read_lock_held());
873 
874 	if (napi_id < MIN_NAPI_ID)
875 		return NULL;
876 
877 	napi = napi_by_id(napi_id);
878 
879 	return napi ? napi->dev : NULL;
880 }
881 EXPORT_SYMBOL(dev_get_by_napi_id);
882 
883 /**
884  *	netdev_get_name - get a netdevice name, knowing its ifindex.
885  *	@net: network namespace
886  *	@name: a pointer to the buffer where the name will be stored.
887  *	@ifindex: the ifindex of the interface to get the name from.
888  */
889 int netdev_get_name(struct net *net, char *name, int ifindex)
890 {
891 	struct net_device *dev;
892 	int ret;
893 
894 	down_read(&devnet_rename_sem);
895 	rcu_read_lock();
896 
897 	dev = dev_get_by_index_rcu(net, ifindex);
898 	if (!dev) {
899 		ret = -ENODEV;
900 		goto out;
901 	}
902 
903 	strcpy(name, dev->name);
904 
905 	ret = 0;
906 out:
907 	rcu_read_unlock();
908 	up_read(&devnet_rename_sem);
909 	return ret;
910 }
911 
912 /**
913  *	dev_getbyhwaddr_rcu - find a device by its hardware address
914  *	@net: the applicable net namespace
915  *	@type: media type of device
916  *	@ha: hardware address
917  *
918  *	Search for an interface by MAC address. Returns NULL if the device
919  *	is not found or a pointer to the device.
920  *	The caller must hold RCU or RTNL.
921  *	The returned device has not had its ref count increased
922  *	and the caller must therefore be careful about locking
923  *
924  */
925 
926 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
927 				       const char *ha)
928 {
929 	struct net_device *dev;
930 
931 	for_each_netdev_rcu(net, dev)
932 		if (dev->type == type &&
933 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
934 			return dev;
935 
936 	return NULL;
937 }
938 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
939 
940 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
941 {
942 	struct net_device *dev, *ret = NULL;
943 
944 	rcu_read_lock();
945 	for_each_netdev_rcu(net, dev)
946 		if (dev->type == type) {
947 			dev_hold(dev);
948 			ret = dev;
949 			break;
950 		}
951 	rcu_read_unlock();
952 	return ret;
953 }
954 EXPORT_SYMBOL(dev_getfirstbyhwtype);
955 
956 /**
957  *	__dev_get_by_flags - find any device with given flags
958  *	@net: the applicable net namespace
959  *	@if_flags: IFF_* values
960  *	@mask: bitmask of bits in if_flags to check
961  *
962  *	Search for any interface with the given flags. Returns NULL if a device
963  *	is not found or a pointer to the device. Must be called inside
964  *	rtnl_lock(), and result refcount is unchanged.
965  */
966 
967 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
968 				      unsigned short mask)
969 {
970 	struct net_device *dev, *ret;
971 
972 	ASSERT_RTNL();
973 
974 	ret = NULL;
975 	for_each_netdev(net, dev) {
976 		if (((dev->flags ^ if_flags) & mask) == 0) {
977 			ret = dev;
978 			break;
979 		}
980 	}
981 	return ret;
982 }
983 EXPORT_SYMBOL(__dev_get_by_flags);
984 
985 /**
986  *	dev_valid_name - check if name is okay for network device
987  *	@name: name string
988  *
989  *	Network device names need to be valid file names to
990  *	allow sysfs to work.  We also disallow any kind of
991  *	whitespace.
992  */
993 bool dev_valid_name(const char *name)
994 {
995 	if (*name == '\0')
996 		return false;
997 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
998 		return false;
999 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1000 		return false;
1001 
1002 	while (*name) {
1003 		if (*name == '/' || *name == ':' || isspace(*name))
1004 			return false;
1005 		name++;
1006 	}
1007 	return true;
1008 }
1009 EXPORT_SYMBOL(dev_valid_name);
1010 
1011 /**
1012  *	__dev_alloc_name - allocate a name for a device
1013  *	@net: network namespace to allocate the device name in
1014  *	@name: name format string
1015  *	@buf:  scratch buffer and result name string
1016  *
1017  *	Passed a format string - eg "lt%d" it will try and find a suitable
1018  *	id. It scans list of devices to build up a free map, then chooses
1019  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1020  *	while allocating the name and adding the device in order to avoid
1021  *	duplicates.
1022  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1023  *	Returns the number of the unit assigned or a negative errno code.
1024  */
1025 
1026 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1027 {
1028 	int i = 0;
1029 	const char *p;
1030 	const int max_netdevices = 8*PAGE_SIZE;
1031 	unsigned long *inuse;
1032 	struct net_device *d;
1033 
1034 	if (!dev_valid_name(name))
1035 		return -EINVAL;
1036 
1037 	p = strchr(name, '%');
1038 	if (p) {
1039 		/*
1040 		 * Verify the string as this thing may have come from
1041 		 * the user.  There must be either one "%d" and no other "%"
1042 		 * characters.
1043 		 */
1044 		if (p[1] != 'd' || strchr(p + 2, '%'))
1045 			return -EINVAL;
1046 
1047 		/* Use one page as a bit array of possible slots */
1048 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1049 		if (!inuse)
1050 			return -ENOMEM;
1051 
1052 		for_each_netdev(net, d) {
1053 			struct netdev_name_node *name_node;
1054 			list_for_each_entry(name_node, &d->name_node->list, list) {
1055 				if (!sscanf(name_node->name, name, &i))
1056 					continue;
1057 				if (i < 0 || i >= max_netdevices)
1058 					continue;
1059 
1060 				/*  avoid cases where sscanf is not exact inverse of printf */
1061 				snprintf(buf, IFNAMSIZ, name, i);
1062 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1063 					__set_bit(i, inuse);
1064 			}
1065 			if (!sscanf(d->name, name, &i))
1066 				continue;
1067 			if (i < 0 || i >= max_netdevices)
1068 				continue;
1069 
1070 			/*  avoid cases where sscanf is not exact inverse of printf */
1071 			snprintf(buf, IFNAMSIZ, name, i);
1072 			if (!strncmp(buf, d->name, IFNAMSIZ))
1073 				__set_bit(i, inuse);
1074 		}
1075 
1076 		i = find_first_zero_bit(inuse, max_netdevices);
1077 		free_page((unsigned long) inuse);
1078 	}
1079 
1080 	snprintf(buf, IFNAMSIZ, name, i);
1081 	if (!netdev_name_in_use(net, buf))
1082 		return i;
1083 
1084 	/* It is possible to run out of possible slots
1085 	 * when the name is long and there isn't enough space left
1086 	 * for the digits, or if all bits are used.
1087 	 */
1088 	return -ENFILE;
1089 }
1090 
1091 static int dev_alloc_name_ns(struct net *net,
1092 			     struct net_device *dev,
1093 			     const char *name)
1094 {
1095 	char buf[IFNAMSIZ];
1096 	int ret;
1097 
1098 	BUG_ON(!net);
1099 	ret = __dev_alloc_name(net, name, buf);
1100 	if (ret >= 0)
1101 		strscpy(dev->name, buf, IFNAMSIZ);
1102 	return ret;
1103 }
1104 
1105 /**
1106  *	dev_alloc_name - allocate a name for a device
1107  *	@dev: device
1108  *	@name: name format string
1109  *
1110  *	Passed a format string - eg "lt%d" it will try and find a suitable
1111  *	id. It scans list of devices to build up a free map, then chooses
1112  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1113  *	while allocating the name and adding the device in order to avoid
1114  *	duplicates.
1115  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1116  *	Returns the number of the unit assigned or a negative errno code.
1117  */
1118 
1119 int dev_alloc_name(struct net_device *dev, const char *name)
1120 {
1121 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1122 }
1123 EXPORT_SYMBOL(dev_alloc_name);
1124 
1125 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1126 			      const char *name)
1127 {
1128 	BUG_ON(!net);
1129 
1130 	if (!dev_valid_name(name))
1131 		return -EINVAL;
1132 
1133 	if (strchr(name, '%'))
1134 		return dev_alloc_name_ns(net, dev, name);
1135 	else if (netdev_name_in_use(net, name))
1136 		return -EEXIST;
1137 	else if (dev->name != name)
1138 		strscpy(dev->name, name, IFNAMSIZ);
1139 
1140 	return 0;
1141 }
1142 
1143 /**
1144  *	dev_change_name - change name of a device
1145  *	@dev: device
1146  *	@newname: name (or format string) must be at least IFNAMSIZ
1147  *
1148  *	Change name of a device, can pass format strings "eth%d".
1149  *	for wildcarding.
1150  */
1151 int dev_change_name(struct net_device *dev, const char *newname)
1152 {
1153 	unsigned char old_assign_type;
1154 	char oldname[IFNAMSIZ];
1155 	int err = 0;
1156 	int ret;
1157 	struct net *net;
1158 
1159 	ASSERT_RTNL();
1160 	BUG_ON(!dev_net(dev));
1161 
1162 	net = dev_net(dev);
1163 
1164 	down_write(&devnet_rename_sem);
1165 
1166 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1167 		up_write(&devnet_rename_sem);
1168 		return 0;
1169 	}
1170 
1171 	memcpy(oldname, dev->name, IFNAMSIZ);
1172 
1173 	err = dev_get_valid_name(net, dev, newname);
1174 	if (err < 0) {
1175 		up_write(&devnet_rename_sem);
1176 		return err;
1177 	}
1178 
1179 	if (oldname[0] && !strchr(oldname, '%'))
1180 		netdev_info(dev, "renamed from %s%s\n", oldname,
1181 			    dev->flags & IFF_UP ? " (while UP)" : "");
1182 
1183 	old_assign_type = dev->name_assign_type;
1184 	dev->name_assign_type = NET_NAME_RENAMED;
1185 
1186 rollback:
1187 	ret = device_rename(&dev->dev, dev->name);
1188 	if (ret) {
1189 		memcpy(dev->name, oldname, IFNAMSIZ);
1190 		dev->name_assign_type = old_assign_type;
1191 		up_write(&devnet_rename_sem);
1192 		return ret;
1193 	}
1194 
1195 	up_write(&devnet_rename_sem);
1196 
1197 	netdev_adjacent_rename_links(dev, oldname);
1198 
1199 	write_lock(&dev_base_lock);
1200 	netdev_name_node_del(dev->name_node);
1201 	write_unlock(&dev_base_lock);
1202 
1203 	synchronize_rcu();
1204 
1205 	write_lock(&dev_base_lock);
1206 	netdev_name_node_add(net, dev->name_node);
1207 	write_unlock(&dev_base_lock);
1208 
1209 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1210 	ret = notifier_to_errno(ret);
1211 
1212 	if (ret) {
1213 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1214 		if (err >= 0) {
1215 			err = ret;
1216 			down_write(&devnet_rename_sem);
1217 			memcpy(dev->name, oldname, IFNAMSIZ);
1218 			memcpy(oldname, newname, IFNAMSIZ);
1219 			dev->name_assign_type = old_assign_type;
1220 			old_assign_type = NET_NAME_RENAMED;
1221 			goto rollback;
1222 		} else {
1223 			netdev_err(dev, "name change rollback failed: %d\n",
1224 				   ret);
1225 		}
1226 	}
1227 
1228 	return err;
1229 }
1230 
1231 /**
1232  *	dev_set_alias - change ifalias of a device
1233  *	@dev: device
1234  *	@alias: name up to IFALIASZ
1235  *	@len: limit of bytes to copy from info
1236  *
1237  *	Set ifalias for a device,
1238  */
1239 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1240 {
1241 	struct dev_ifalias *new_alias = NULL;
1242 
1243 	if (len >= IFALIASZ)
1244 		return -EINVAL;
1245 
1246 	if (len) {
1247 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1248 		if (!new_alias)
1249 			return -ENOMEM;
1250 
1251 		memcpy(new_alias->ifalias, alias, len);
1252 		new_alias->ifalias[len] = 0;
1253 	}
1254 
1255 	mutex_lock(&ifalias_mutex);
1256 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1257 					mutex_is_locked(&ifalias_mutex));
1258 	mutex_unlock(&ifalias_mutex);
1259 
1260 	if (new_alias)
1261 		kfree_rcu(new_alias, rcuhead);
1262 
1263 	return len;
1264 }
1265 EXPORT_SYMBOL(dev_set_alias);
1266 
1267 /**
1268  *	dev_get_alias - get ifalias of a device
1269  *	@dev: device
1270  *	@name: buffer to store name of ifalias
1271  *	@len: size of buffer
1272  *
1273  *	get ifalias for a device.  Caller must make sure dev cannot go
1274  *	away,  e.g. rcu read lock or own a reference count to device.
1275  */
1276 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1277 {
1278 	const struct dev_ifalias *alias;
1279 	int ret = 0;
1280 
1281 	rcu_read_lock();
1282 	alias = rcu_dereference(dev->ifalias);
1283 	if (alias)
1284 		ret = snprintf(name, len, "%s", alias->ifalias);
1285 	rcu_read_unlock();
1286 
1287 	return ret;
1288 }
1289 
1290 /**
1291  *	netdev_features_change - device changes features
1292  *	@dev: device to cause notification
1293  *
1294  *	Called to indicate a device has changed features.
1295  */
1296 void netdev_features_change(struct net_device *dev)
1297 {
1298 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1299 }
1300 EXPORT_SYMBOL(netdev_features_change);
1301 
1302 /**
1303  *	netdev_state_change - device changes state
1304  *	@dev: device to cause notification
1305  *
1306  *	Called to indicate a device has changed state. This function calls
1307  *	the notifier chains for netdev_chain and sends a NEWLINK message
1308  *	to the routing socket.
1309  */
1310 void netdev_state_change(struct net_device *dev)
1311 {
1312 	if (dev->flags & IFF_UP) {
1313 		struct netdev_notifier_change_info change_info = {
1314 			.info.dev = dev,
1315 		};
1316 
1317 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1318 					      &change_info.info);
1319 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1320 	}
1321 }
1322 EXPORT_SYMBOL(netdev_state_change);
1323 
1324 /**
1325  * __netdev_notify_peers - notify network peers about existence of @dev,
1326  * to be called when rtnl lock is already held.
1327  * @dev: network device
1328  *
1329  * Generate traffic such that interested network peers are aware of
1330  * @dev, such as by generating a gratuitous ARP. This may be used when
1331  * a device wants to inform the rest of the network about some sort of
1332  * reconfiguration such as a failover event or virtual machine
1333  * migration.
1334  */
1335 void __netdev_notify_peers(struct net_device *dev)
1336 {
1337 	ASSERT_RTNL();
1338 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1339 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1340 }
1341 EXPORT_SYMBOL(__netdev_notify_peers);
1342 
1343 /**
1344  * netdev_notify_peers - notify network peers about existence of @dev
1345  * @dev: network device
1346  *
1347  * Generate traffic such that interested network peers are aware of
1348  * @dev, such as by generating a gratuitous ARP. This may be used when
1349  * a device wants to inform the rest of the network about some sort of
1350  * reconfiguration such as a failover event or virtual machine
1351  * migration.
1352  */
1353 void netdev_notify_peers(struct net_device *dev)
1354 {
1355 	rtnl_lock();
1356 	__netdev_notify_peers(dev);
1357 	rtnl_unlock();
1358 }
1359 EXPORT_SYMBOL(netdev_notify_peers);
1360 
1361 static int napi_threaded_poll(void *data);
1362 
1363 static int napi_kthread_create(struct napi_struct *n)
1364 {
1365 	int err = 0;
1366 
1367 	/* Create and wake up the kthread once to put it in
1368 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1369 	 * warning and work with loadavg.
1370 	 */
1371 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1372 				n->dev->name, n->napi_id);
1373 	if (IS_ERR(n->thread)) {
1374 		err = PTR_ERR(n->thread);
1375 		pr_err("kthread_run failed with err %d\n", err);
1376 		n->thread = NULL;
1377 	}
1378 
1379 	return err;
1380 }
1381 
1382 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1383 {
1384 	const struct net_device_ops *ops = dev->netdev_ops;
1385 	int ret;
1386 
1387 	ASSERT_RTNL();
1388 	dev_addr_check(dev);
1389 
1390 	if (!netif_device_present(dev)) {
1391 		/* may be detached because parent is runtime-suspended */
1392 		if (dev->dev.parent)
1393 			pm_runtime_resume(dev->dev.parent);
1394 		if (!netif_device_present(dev))
1395 			return -ENODEV;
1396 	}
1397 
1398 	/* Block netpoll from trying to do any rx path servicing.
1399 	 * If we don't do this there is a chance ndo_poll_controller
1400 	 * or ndo_poll may be running while we open the device
1401 	 */
1402 	netpoll_poll_disable(dev);
1403 
1404 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1405 	ret = notifier_to_errno(ret);
1406 	if (ret)
1407 		return ret;
1408 
1409 	set_bit(__LINK_STATE_START, &dev->state);
1410 
1411 	if (ops->ndo_validate_addr)
1412 		ret = ops->ndo_validate_addr(dev);
1413 
1414 	if (!ret && ops->ndo_open)
1415 		ret = ops->ndo_open(dev);
1416 
1417 	netpoll_poll_enable(dev);
1418 
1419 	if (ret)
1420 		clear_bit(__LINK_STATE_START, &dev->state);
1421 	else {
1422 		dev->flags |= IFF_UP;
1423 		dev_set_rx_mode(dev);
1424 		dev_activate(dev);
1425 		add_device_randomness(dev->dev_addr, dev->addr_len);
1426 	}
1427 
1428 	return ret;
1429 }
1430 
1431 /**
1432  *	dev_open	- prepare an interface for use.
1433  *	@dev: device to open
1434  *	@extack: netlink extended ack
1435  *
1436  *	Takes a device from down to up state. The device's private open
1437  *	function is invoked and then the multicast lists are loaded. Finally
1438  *	the device is moved into the up state and a %NETDEV_UP message is
1439  *	sent to the netdev notifier chain.
1440  *
1441  *	Calling this function on an active interface is a nop. On a failure
1442  *	a negative errno code is returned.
1443  */
1444 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1445 {
1446 	int ret;
1447 
1448 	if (dev->flags & IFF_UP)
1449 		return 0;
1450 
1451 	ret = __dev_open(dev, extack);
1452 	if (ret < 0)
1453 		return ret;
1454 
1455 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1456 	call_netdevice_notifiers(NETDEV_UP, dev);
1457 
1458 	return ret;
1459 }
1460 EXPORT_SYMBOL(dev_open);
1461 
1462 static void __dev_close_many(struct list_head *head)
1463 {
1464 	struct net_device *dev;
1465 
1466 	ASSERT_RTNL();
1467 	might_sleep();
1468 
1469 	list_for_each_entry(dev, head, close_list) {
1470 		/* Temporarily disable netpoll until the interface is down */
1471 		netpoll_poll_disable(dev);
1472 
1473 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1474 
1475 		clear_bit(__LINK_STATE_START, &dev->state);
1476 
1477 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1478 		 * can be even on different cpu. So just clear netif_running().
1479 		 *
1480 		 * dev->stop() will invoke napi_disable() on all of it's
1481 		 * napi_struct instances on this device.
1482 		 */
1483 		smp_mb__after_atomic(); /* Commit netif_running(). */
1484 	}
1485 
1486 	dev_deactivate_many(head);
1487 
1488 	list_for_each_entry(dev, head, close_list) {
1489 		const struct net_device_ops *ops = dev->netdev_ops;
1490 
1491 		/*
1492 		 *	Call the device specific close. This cannot fail.
1493 		 *	Only if device is UP
1494 		 *
1495 		 *	We allow it to be called even after a DETACH hot-plug
1496 		 *	event.
1497 		 */
1498 		if (ops->ndo_stop)
1499 			ops->ndo_stop(dev);
1500 
1501 		dev->flags &= ~IFF_UP;
1502 		netpoll_poll_enable(dev);
1503 	}
1504 }
1505 
1506 static void __dev_close(struct net_device *dev)
1507 {
1508 	LIST_HEAD(single);
1509 
1510 	list_add(&dev->close_list, &single);
1511 	__dev_close_many(&single);
1512 	list_del(&single);
1513 }
1514 
1515 void dev_close_many(struct list_head *head, bool unlink)
1516 {
1517 	struct net_device *dev, *tmp;
1518 
1519 	/* Remove the devices that don't need to be closed */
1520 	list_for_each_entry_safe(dev, tmp, head, close_list)
1521 		if (!(dev->flags & IFF_UP))
1522 			list_del_init(&dev->close_list);
1523 
1524 	__dev_close_many(head);
1525 
1526 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1527 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1528 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1529 		if (unlink)
1530 			list_del_init(&dev->close_list);
1531 	}
1532 }
1533 EXPORT_SYMBOL(dev_close_many);
1534 
1535 /**
1536  *	dev_close - shutdown an interface.
1537  *	@dev: device to shutdown
1538  *
1539  *	This function moves an active device into down state. A
1540  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1541  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1542  *	chain.
1543  */
1544 void dev_close(struct net_device *dev)
1545 {
1546 	if (dev->flags & IFF_UP) {
1547 		LIST_HEAD(single);
1548 
1549 		list_add(&dev->close_list, &single);
1550 		dev_close_many(&single, true);
1551 		list_del(&single);
1552 	}
1553 }
1554 EXPORT_SYMBOL(dev_close);
1555 
1556 
1557 /**
1558  *	dev_disable_lro - disable Large Receive Offload on a device
1559  *	@dev: device
1560  *
1561  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1562  *	called under RTNL.  This is needed if received packets may be
1563  *	forwarded to another interface.
1564  */
1565 void dev_disable_lro(struct net_device *dev)
1566 {
1567 	struct net_device *lower_dev;
1568 	struct list_head *iter;
1569 
1570 	dev->wanted_features &= ~NETIF_F_LRO;
1571 	netdev_update_features(dev);
1572 
1573 	if (unlikely(dev->features & NETIF_F_LRO))
1574 		netdev_WARN(dev, "failed to disable LRO!\n");
1575 
1576 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1577 		dev_disable_lro(lower_dev);
1578 }
1579 EXPORT_SYMBOL(dev_disable_lro);
1580 
1581 /**
1582  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1583  *	@dev: device
1584  *
1585  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1586  *	called under RTNL.  This is needed if Generic XDP is installed on
1587  *	the device.
1588  */
1589 static void dev_disable_gro_hw(struct net_device *dev)
1590 {
1591 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1592 	netdev_update_features(dev);
1593 
1594 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1595 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1596 }
1597 
1598 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1599 {
1600 #define N(val) 						\
1601 	case NETDEV_##val:				\
1602 		return "NETDEV_" __stringify(val);
1603 	switch (cmd) {
1604 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1605 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1606 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1607 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1608 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1609 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1610 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1611 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1612 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1613 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1614 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1615 	N(XDP_FEAT_CHANGE)
1616 	}
1617 #undef N
1618 	return "UNKNOWN_NETDEV_EVENT";
1619 }
1620 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1621 
1622 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1623 				   struct net_device *dev)
1624 {
1625 	struct netdev_notifier_info info = {
1626 		.dev = dev,
1627 	};
1628 
1629 	return nb->notifier_call(nb, val, &info);
1630 }
1631 
1632 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1633 					     struct net_device *dev)
1634 {
1635 	int err;
1636 
1637 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1638 	err = notifier_to_errno(err);
1639 	if (err)
1640 		return err;
1641 
1642 	if (!(dev->flags & IFF_UP))
1643 		return 0;
1644 
1645 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1646 	return 0;
1647 }
1648 
1649 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1650 						struct net_device *dev)
1651 {
1652 	if (dev->flags & IFF_UP) {
1653 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1654 					dev);
1655 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1656 	}
1657 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1658 }
1659 
1660 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1661 						 struct net *net)
1662 {
1663 	struct net_device *dev;
1664 	int err;
1665 
1666 	for_each_netdev(net, dev) {
1667 		err = call_netdevice_register_notifiers(nb, dev);
1668 		if (err)
1669 			goto rollback;
1670 	}
1671 	return 0;
1672 
1673 rollback:
1674 	for_each_netdev_continue_reverse(net, dev)
1675 		call_netdevice_unregister_notifiers(nb, dev);
1676 	return err;
1677 }
1678 
1679 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1680 						    struct net *net)
1681 {
1682 	struct net_device *dev;
1683 
1684 	for_each_netdev(net, dev)
1685 		call_netdevice_unregister_notifiers(nb, dev);
1686 }
1687 
1688 static int dev_boot_phase = 1;
1689 
1690 /**
1691  * register_netdevice_notifier - register a network notifier block
1692  * @nb: notifier
1693  *
1694  * Register a notifier to be called when network device events occur.
1695  * The notifier passed is linked into the kernel structures and must
1696  * not be reused until it has been unregistered. A negative errno code
1697  * is returned on a failure.
1698  *
1699  * When registered all registration and up events are replayed
1700  * to the new notifier to allow device to have a race free
1701  * view of the network device list.
1702  */
1703 
1704 int register_netdevice_notifier(struct notifier_block *nb)
1705 {
1706 	struct net *net;
1707 	int err;
1708 
1709 	/* Close race with setup_net() and cleanup_net() */
1710 	down_write(&pernet_ops_rwsem);
1711 	rtnl_lock();
1712 	err = raw_notifier_chain_register(&netdev_chain, nb);
1713 	if (err)
1714 		goto unlock;
1715 	if (dev_boot_phase)
1716 		goto unlock;
1717 	for_each_net(net) {
1718 		err = call_netdevice_register_net_notifiers(nb, net);
1719 		if (err)
1720 			goto rollback;
1721 	}
1722 
1723 unlock:
1724 	rtnl_unlock();
1725 	up_write(&pernet_ops_rwsem);
1726 	return err;
1727 
1728 rollback:
1729 	for_each_net_continue_reverse(net)
1730 		call_netdevice_unregister_net_notifiers(nb, net);
1731 
1732 	raw_notifier_chain_unregister(&netdev_chain, nb);
1733 	goto unlock;
1734 }
1735 EXPORT_SYMBOL(register_netdevice_notifier);
1736 
1737 /**
1738  * unregister_netdevice_notifier - unregister a network notifier block
1739  * @nb: notifier
1740  *
1741  * Unregister a notifier previously registered by
1742  * register_netdevice_notifier(). The notifier is unlinked into the
1743  * kernel structures and may then be reused. A negative errno code
1744  * is returned on a failure.
1745  *
1746  * After unregistering unregister and down device events are synthesized
1747  * for all devices on the device list to the removed notifier to remove
1748  * the need for special case cleanup code.
1749  */
1750 
1751 int unregister_netdevice_notifier(struct notifier_block *nb)
1752 {
1753 	struct net *net;
1754 	int err;
1755 
1756 	/* Close race with setup_net() and cleanup_net() */
1757 	down_write(&pernet_ops_rwsem);
1758 	rtnl_lock();
1759 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1760 	if (err)
1761 		goto unlock;
1762 
1763 	for_each_net(net)
1764 		call_netdevice_unregister_net_notifiers(nb, net);
1765 
1766 unlock:
1767 	rtnl_unlock();
1768 	up_write(&pernet_ops_rwsem);
1769 	return err;
1770 }
1771 EXPORT_SYMBOL(unregister_netdevice_notifier);
1772 
1773 static int __register_netdevice_notifier_net(struct net *net,
1774 					     struct notifier_block *nb,
1775 					     bool ignore_call_fail)
1776 {
1777 	int err;
1778 
1779 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1780 	if (err)
1781 		return err;
1782 	if (dev_boot_phase)
1783 		return 0;
1784 
1785 	err = call_netdevice_register_net_notifiers(nb, net);
1786 	if (err && !ignore_call_fail)
1787 		goto chain_unregister;
1788 
1789 	return 0;
1790 
1791 chain_unregister:
1792 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1793 	return err;
1794 }
1795 
1796 static int __unregister_netdevice_notifier_net(struct net *net,
1797 					       struct notifier_block *nb)
1798 {
1799 	int err;
1800 
1801 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1802 	if (err)
1803 		return err;
1804 
1805 	call_netdevice_unregister_net_notifiers(nb, net);
1806 	return 0;
1807 }
1808 
1809 /**
1810  * register_netdevice_notifier_net - register a per-netns network notifier block
1811  * @net: network namespace
1812  * @nb: notifier
1813  *
1814  * Register a notifier to be called when network device events occur.
1815  * The notifier passed is linked into the kernel structures and must
1816  * not be reused until it has been unregistered. A negative errno code
1817  * is returned on a failure.
1818  *
1819  * When registered all registration and up events are replayed
1820  * to the new notifier to allow device to have a race free
1821  * view of the network device list.
1822  */
1823 
1824 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1825 {
1826 	int err;
1827 
1828 	rtnl_lock();
1829 	err = __register_netdevice_notifier_net(net, nb, false);
1830 	rtnl_unlock();
1831 	return err;
1832 }
1833 EXPORT_SYMBOL(register_netdevice_notifier_net);
1834 
1835 /**
1836  * unregister_netdevice_notifier_net - unregister a per-netns
1837  *                                     network notifier block
1838  * @net: network namespace
1839  * @nb: notifier
1840  *
1841  * Unregister a notifier previously registered by
1842  * register_netdevice_notifier_net(). The notifier is unlinked from the
1843  * kernel structures and may then be reused. A negative errno code
1844  * is returned on a failure.
1845  *
1846  * After unregistering unregister and down device events are synthesized
1847  * for all devices on the device list to the removed notifier to remove
1848  * the need for special case cleanup code.
1849  */
1850 
1851 int unregister_netdevice_notifier_net(struct net *net,
1852 				      struct notifier_block *nb)
1853 {
1854 	int err;
1855 
1856 	rtnl_lock();
1857 	err = __unregister_netdevice_notifier_net(net, nb);
1858 	rtnl_unlock();
1859 	return err;
1860 }
1861 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1862 
1863 static void __move_netdevice_notifier_net(struct net *src_net,
1864 					  struct net *dst_net,
1865 					  struct notifier_block *nb)
1866 {
1867 	__unregister_netdevice_notifier_net(src_net, nb);
1868 	__register_netdevice_notifier_net(dst_net, nb, true);
1869 }
1870 
1871 int register_netdevice_notifier_dev_net(struct net_device *dev,
1872 					struct notifier_block *nb,
1873 					struct netdev_net_notifier *nn)
1874 {
1875 	int err;
1876 
1877 	rtnl_lock();
1878 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1879 	if (!err) {
1880 		nn->nb = nb;
1881 		list_add(&nn->list, &dev->net_notifier_list);
1882 	}
1883 	rtnl_unlock();
1884 	return err;
1885 }
1886 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1887 
1888 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1889 					  struct notifier_block *nb,
1890 					  struct netdev_net_notifier *nn)
1891 {
1892 	int err;
1893 
1894 	rtnl_lock();
1895 	list_del(&nn->list);
1896 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1897 	rtnl_unlock();
1898 	return err;
1899 }
1900 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1901 
1902 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1903 					     struct net *net)
1904 {
1905 	struct netdev_net_notifier *nn;
1906 
1907 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1908 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1909 }
1910 
1911 /**
1912  *	call_netdevice_notifiers_info - call all network notifier blocks
1913  *	@val: value passed unmodified to notifier function
1914  *	@info: notifier information data
1915  *
1916  *	Call all network notifier blocks.  Parameters and return value
1917  *	are as for raw_notifier_call_chain().
1918  */
1919 
1920 int call_netdevice_notifiers_info(unsigned long val,
1921 				  struct netdev_notifier_info *info)
1922 {
1923 	struct net *net = dev_net(info->dev);
1924 	int ret;
1925 
1926 	ASSERT_RTNL();
1927 
1928 	/* Run per-netns notifier block chain first, then run the global one.
1929 	 * Hopefully, one day, the global one is going to be removed after
1930 	 * all notifier block registrators get converted to be per-netns.
1931 	 */
1932 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1933 	if (ret & NOTIFY_STOP_MASK)
1934 		return ret;
1935 	return raw_notifier_call_chain(&netdev_chain, val, info);
1936 }
1937 
1938 /**
1939  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1940  *	                                       for and rollback on error
1941  *	@val_up: value passed unmodified to notifier function
1942  *	@val_down: value passed unmodified to the notifier function when
1943  *	           recovering from an error on @val_up
1944  *	@info: notifier information data
1945  *
1946  *	Call all per-netns network notifier blocks, but not notifier blocks on
1947  *	the global notifier chain. Parameters and return value are as for
1948  *	raw_notifier_call_chain_robust().
1949  */
1950 
1951 static int
1952 call_netdevice_notifiers_info_robust(unsigned long val_up,
1953 				     unsigned long val_down,
1954 				     struct netdev_notifier_info *info)
1955 {
1956 	struct net *net = dev_net(info->dev);
1957 
1958 	ASSERT_RTNL();
1959 
1960 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1961 					      val_up, val_down, info);
1962 }
1963 
1964 static int call_netdevice_notifiers_extack(unsigned long val,
1965 					   struct net_device *dev,
1966 					   struct netlink_ext_ack *extack)
1967 {
1968 	struct netdev_notifier_info info = {
1969 		.dev = dev,
1970 		.extack = extack,
1971 	};
1972 
1973 	return call_netdevice_notifiers_info(val, &info);
1974 }
1975 
1976 /**
1977  *	call_netdevice_notifiers - call all network notifier blocks
1978  *      @val: value passed unmodified to notifier function
1979  *      @dev: net_device pointer passed unmodified to notifier function
1980  *
1981  *	Call all network notifier blocks.  Parameters and return value
1982  *	are as for raw_notifier_call_chain().
1983  */
1984 
1985 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1986 {
1987 	return call_netdevice_notifiers_extack(val, dev, NULL);
1988 }
1989 EXPORT_SYMBOL(call_netdevice_notifiers);
1990 
1991 /**
1992  *	call_netdevice_notifiers_mtu - call all network notifier blocks
1993  *	@val: value passed unmodified to notifier function
1994  *	@dev: net_device pointer passed unmodified to notifier function
1995  *	@arg: additional u32 argument passed to the notifier function
1996  *
1997  *	Call all network notifier blocks.  Parameters and return value
1998  *	are as for raw_notifier_call_chain().
1999  */
2000 static int call_netdevice_notifiers_mtu(unsigned long val,
2001 					struct net_device *dev, u32 arg)
2002 {
2003 	struct netdev_notifier_info_ext info = {
2004 		.info.dev = dev,
2005 		.ext.mtu = arg,
2006 	};
2007 
2008 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2009 
2010 	return call_netdevice_notifiers_info(val, &info.info);
2011 }
2012 
2013 #ifdef CONFIG_NET_INGRESS
2014 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2015 
2016 void net_inc_ingress_queue(void)
2017 {
2018 	static_branch_inc(&ingress_needed_key);
2019 }
2020 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2021 
2022 void net_dec_ingress_queue(void)
2023 {
2024 	static_branch_dec(&ingress_needed_key);
2025 }
2026 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2027 #endif
2028 
2029 #ifdef CONFIG_NET_EGRESS
2030 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2031 
2032 void net_inc_egress_queue(void)
2033 {
2034 	static_branch_inc(&egress_needed_key);
2035 }
2036 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2037 
2038 void net_dec_egress_queue(void)
2039 {
2040 	static_branch_dec(&egress_needed_key);
2041 }
2042 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2043 #endif
2044 
2045 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2046 EXPORT_SYMBOL(netstamp_needed_key);
2047 #ifdef CONFIG_JUMP_LABEL
2048 static atomic_t netstamp_needed_deferred;
2049 static atomic_t netstamp_wanted;
2050 static void netstamp_clear(struct work_struct *work)
2051 {
2052 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2053 	int wanted;
2054 
2055 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2056 	if (wanted > 0)
2057 		static_branch_enable(&netstamp_needed_key);
2058 	else
2059 		static_branch_disable(&netstamp_needed_key);
2060 }
2061 static DECLARE_WORK(netstamp_work, netstamp_clear);
2062 #endif
2063 
2064 void net_enable_timestamp(void)
2065 {
2066 #ifdef CONFIG_JUMP_LABEL
2067 	int wanted = atomic_read(&netstamp_wanted);
2068 
2069 	while (wanted > 0) {
2070 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2071 			return;
2072 	}
2073 	atomic_inc(&netstamp_needed_deferred);
2074 	schedule_work(&netstamp_work);
2075 #else
2076 	static_branch_inc(&netstamp_needed_key);
2077 #endif
2078 }
2079 EXPORT_SYMBOL(net_enable_timestamp);
2080 
2081 void net_disable_timestamp(void)
2082 {
2083 #ifdef CONFIG_JUMP_LABEL
2084 	int wanted = atomic_read(&netstamp_wanted);
2085 
2086 	while (wanted > 1) {
2087 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2088 			return;
2089 	}
2090 	atomic_dec(&netstamp_needed_deferred);
2091 	schedule_work(&netstamp_work);
2092 #else
2093 	static_branch_dec(&netstamp_needed_key);
2094 #endif
2095 }
2096 EXPORT_SYMBOL(net_disable_timestamp);
2097 
2098 static inline void net_timestamp_set(struct sk_buff *skb)
2099 {
2100 	skb->tstamp = 0;
2101 	skb->mono_delivery_time = 0;
2102 	if (static_branch_unlikely(&netstamp_needed_key))
2103 		skb->tstamp = ktime_get_real();
2104 }
2105 
2106 #define net_timestamp_check(COND, SKB)				\
2107 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2108 		if ((COND) && !(SKB)->tstamp)			\
2109 			(SKB)->tstamp = ktime_get_real();	\
2110 	}							\
2111 
2112 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2113 {
2114 	return __is_skb_forwardable(dev, skb, true);
2115 }
2116 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2117 
2118 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2119 			      bool check_mtu)
2120 {
2121 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2122 
2123 	if (likely(!ret)) {
2124 		skb->protocol = eth_type_trans(skb, dev);
2125 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2126 	}
2127 
2128 	return ret;
2129 }
2130 
2131 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2132 {
2133 	return __dev_forward_skb2(dev, skb, true);
2134 }
2135 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2136 
2137 /**
2138  * dev_forward_skb - loopback an skb to another netif
2139  *
2140  * @dev: destination network device
2141  * @skb: buffer to forward
2142  *
2143  * return values:
2144  *	NET_RX_SUCCESS	(no congestion)
2145  *	NET_RX_DROP     (packet was dropped, but freed)
2146  *
2147  * dev_forward_skb can be used for injecting an skb from the
2148  * start_xmit function of one device into the receive queue
2149  * of another device.
2150  *
2151  * The receiving device may be in another namespace, so
2152  * we have to clear all information in the skb that could
2153  * impact namespace isolation.
2154  */
2155 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2156 {
2157 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2158 }
2159 EXPORT_SYMBOL_GPL(dev_forward_skb);
2160 
2161 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2162 {
2163 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2164 }
2165 
2166 static inline int deliver_skb(struct sk_buff *skb,
2167 			      struct packet_type *pt_prev,
2168 			      struct net_device *orig_dev)
2169 {
2170 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2171 		return -ENOMEM;
2172 	refcount_inc(&skb->users);
2173 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2174 }
2175 
2176 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2177 					  struct packet_type **pt,
2178 					  struct net_device *orig_dev,
2179 					  __be16 type,
2180 					  struct list_head *ptype_list)
2181 {
2182 	struct packet_type *ptype, *pt_prev = *pt;
2183 
2184 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2185 		if (ptype->type != type)
2186 			continue;
2187 		if (pt_prev)
2188 			deliver_skb(skb, pt_prev, orig_dev);
2189 		pt_prev = ptype;
2190 	}
2191 	*pt = pt_prev;
2192 }
2193 
2194 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2195 {
2196 	if (!ptype->af_packet_priv || !skb->sk)
2197 		return false;
2198 
2199 	if (ptype->id_match)
2200 		return ptype->id_match(ptype, skb->sk);
2201 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2202 		return true;
2203 
2204 	return false;
2205 }
2206 
2207 /**
2208  * dev_nit_active - return true if any network interface taps are in use
2209  *
2210  * @dev: network device to check for the presence of taps
2211  */
2212 bool dev_nit_active(struct net_device *dev)
2213 {
2214 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2215 }
2216 EXPORT_SYMBOL_GPL(dev_nit_active);
2217 
2218 /*
2219  *	Support routine. Sends outgoing frames to any network
2220  *	taps currently in use.
2221  */
2222 
2223 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2224 {
2225 	struct packet_type *ptype;
2226 	struct sk_buff *skb2 = NULL;
2227 	struct packet_type *pt_prev = NULL;
2228 	struct list_head *ptype_list = &ptype_all;
2229 
2230 	rcu_read_lock();
2231 again:
2232 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2233 		if (ptype->ignore_outgoing)
2234 			continue;
2235 
2236 		/* Never send packets back to the socket
2237 		 * they originated from - MvS (miquels@drinkel.ow.org)
2238 		 */
2239 		if (skb_loop_sk(ptype, skb))
2240 			continue;
2241 
2242 		if (pt_prev) {
2243 			deliver_skb(skb2, pt_prev, skb->dev);
2244 			pt_prev = ptype;
2245 			continue;
2246 		}
2247 
2248 		/* need to clone skb, done only once */
2249 		skb2 = skb_clone(skb, GFP_ATOMIC);
2250 		if (!skb2)
2251 			goto out_unlock;
2252 
2253 		net_timestamp_set(skb2);
2254 
2255 		/* skb->nh should be correctly
2256 		 * set by sender, so that the second statement is
2257 		 * just protection against buggy protocols.
2258 		 */
2259 		skb_reset_mac_header(skb2);
2260 
2261 		if (skb_network_header(skb2) < skb2->data ||
2262 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2263 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2264 					     ntohs(skb2->protocol),
2265 					     dev->name);
2266 			skb_reset_network_header(skb2);
2267 		}
2268 
2269 		skb2->transport_header = skb2->network_header;
2270 		skb2->pkt_type = PACKET_OUTGOING;
2271 		pt_prev = ptype;
2272 	}
2273 
2274 	if (ptype_list == &ptype_all) {
2275 		ptype_list = &dev->ptype_all;
2276 		goto again;
2277 	}
2278 out_unlock:
2279 	if (pt_prev) {
2280 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2281 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2282 		else
2283 			kfree_skb(skb2);
2284 	}
2285 	rcu_read_unlock();
2286 }
2287 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2288 
2289 /**
2290  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2291  * @dev: Network device
2292  * @txq: number of queues available
2293  *
2294  * If real_num_tx_queues is changed the tc mappings may no longer be
2295  * valid. To resolve this verify the tc mapping remains valid and if
2296  * not NULL the mapping. With no priorities mapping to this
2297  * offset/count pair it will no longer be used. In the worst case TC0
2298  * is invalid nothing can be done so disable priority mappings. If is
2299  * expected that drivers will fix this mapping if they can before
2300  * calling netif_set_real_num_tx_queues.
2301  */
2302 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2303 {
2304 	int i;
2305 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2306 
2307 	/* If TC0 is invalidated disable TC mapping */
2308 	if (tc->offset + tc->count > txq) {
2309 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2310 		dev->num_tc = 0;
2311 		return;
2312 	}
2313 
2314 	/* Invalidated prio to tc mappings set to TC0 */
2315 	for (i = 1; i < TC_BITMASK + 1; i++) {
2316 		int q = netdev_get_prio_tc_map(dev, i);
2317 
2318 		tc = &dev->tc_to_txq[q];
2319 		if (tc->offset + tc->count > txq) {
2320 			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",
2321 				    i, q);
2322 			netdev_set_prio_tc_map(dev, i, 0);
2323 		}
2324 	}
2325 }
2326 
2327 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2328 {
2329 	if (dev->num_tc) {
2330 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2331 		int i;
2332 
2333 		/* walk through the TCs and see if it falls into any of them */
2334 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2335 			if ((txq - tc->offset) < tc->count)
2336 				return i;
2337 		}
2338 
2339 		/* didn't find it, just return -1 to indicate no match */
2340 		return -1;
2341 	}
2342 
2343 	return 0;
2344 }
2345 EXPORT_SYMBOL(netdev_txq_to_tc);
2346 
2347 #ifdef CONFIG_XPS
2348 static struct static_key xps_needed __read_mostly;
2349 static struct static_key xps_rxqs_needed __read_mostly;
2350 static DEFINE_MUTEX(xps_map_mutex);
2351 #define xmap_dereference(P)		\
2352 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2353 
2354 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2355 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2356 {
2357 	struct xps_map *map = NULL;
2358 	int pos;
2359 
2360 	if (dev_maps)
2361 		map = xmap_dereference(dev_maps->attr_map[tci]);
2362 	if (!map)
2363 		return false;
2364 
2365 	for (pos = map->len; pos--;) {
2366 		if (map->queues[pos] != index)
2367 			continue;
2368 
2369 		if (map->len > 1) {
2370 			map->queues[pos] = map->queues[--map->len];
2371 			break;
2372 		}
2373 
2374 		if (old_maps)
2375 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2376 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2377 		kfree_rcu(map, rcu);
2378 		return false;
2379 	}
2380 
2381 	return true;
2382 }
2383 
2384 static bool remove_xps_queue_cpu(struct net_device *dev,
2385 				 struct xps_dev_maps *dev_maps,
2386 				 int cpu, u16 offset, u16 count)
2387 {
2388 	int num_tc = dev_maps->num_tc;
2389 	bool active = false;
2390 	int tci;
2391 
2392 	for (tci = cpu * num_tc; num_tc--; tci++) {
2393 		int i, j;
2394 
2395 		for (i = count, j = offset; i--; j++) {
2396 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2397 				break;
2398 		}
2399 
2400 		active |= i < 0;
2401 	}
2402 
2403 	return active;
2404 }
2405 
2406 static void reset_xps_maps(struct net_device *dev,
2407 			   struct xps_dev_maps *dev_maps,
2408 			   enum xps_map_type type)
2409 {
2410 	static_key_slow_dec_cpuslocked(&xps_needed);
2411 	if (type == XPS_RXQS)
2412 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2413 
2414 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2415 
2416 	kfree_rcu(dev_maps, rcu);
2417 }
2418 
2419 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2420 			   u16 offset, u16 count)
2421 {
2422 	struct xps_dev_maps *dev_maps;
2423 	bool active = false;
2424 	int i, j;
2425 
2426 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2427 	if (!dev_maps)
2428 		return;
2429 
2430 	for (j = 0; j < dev_maps->nr_ids; j++)
2431 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2432 	if (!active)
2433 		reset_xps_maps(dev, dev_maps, type);
2434 
2435 	if (type == XPS_CPUS) {
2436 		for (i = offset + (count - 1); count--; i--)
2437 			netdev_queue_numa_node_write(
2438 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2439 	}
2440 }
2441 
2442 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2443 				   u16 count)
2444 {
2445 	if (!static_key_false(&xps_needed))
2446 		return;
2447 
2448 	cpus_read_lock();
2449 	mutex_lock(&xps_map_mutex);
2450 
2451 	if (static_key_false(&xps_rxqs_needed))
2452 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2453 
2454 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2455 
2456 	mutex_unlock(&xps_map_mutex);
2457 	cpus_read_unlock();
2458 }
2459 
2460 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2461 {
2462 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2463 }
2464 
2465 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2466 				      u16 index, bool is_rxqs_map)
2467 {
2468 	struct xps_map *new_map;
2469 	int alloc_len = XPS_MIN_MAP_ALLOC;
2470 	int i, pos;
2471 
2472 	for (pos = 0; map && pos < map->len; pos++) {
2473 		if (map->queues[pos] != index)
2474 			continue;
2475 		return map;
2476 	}
2477 
2478 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2479 	if (map) {
2480 		if (pos < map->alloc_len)
2481 			return map;
2482 
2483 		alloc_len = map->alloc_len * 2;
2484 	}
2485 
2486 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2487 	 *  map
2488 	 */
2489 	if (is_rxqs_map)
2490 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2491 	else
2492 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2493 				       cpu_to_node(attr_index));
2494 	if (!new_map)
2495 		return NULL;
2496 
2497 	for (i = 0; i < pos; i++)
2498 		new_map->queues[i] = map->queues[i];
2499 	new_map->alloc_len = alloc_len;
2500 	new_map->len = pos;
2501 
2502 	return new_map;
2503 }
2504 
2505 /* Copy xps maps at a given index */
2506 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2507 			      struct xps_dev_maps *new_dev_maps, int index,
2508 			      int tc, bool skip_tc)
2509 {
2510 	int i, tci = index * dev_maps->num_tc;
2511 	struct xps_map *map;
2512 
2513 	/* copy maps belonging to foreign traffic classes */
2514 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2515 		if (i == tc && skip_tc)
2516 			continue;
2517 
2518 		/* fill in the new device map from the old device map */
2519 		map = xmap_dereference(dev_maps->attr_map[tci]);
2520 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2521 	}
2522 }
2523 
2524 /* Must be called under cpus_read_lock */
2525 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2526 			  u16 index, enum xps_map_type type)
2527 {
2528 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2529 	const unsigned long *online_mask = NULL;
2530 	bool active = false, copy = false;
2531 	int i, j, tci, numa_node_id = -2;
2532 	int maps_sz, num_tc = 1, tc = 0;
2533 	struct xps_map *map, *new_map;
2534 	unsigned int nr_ids;
2535 
2536 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2537 
2538 	if (dev->num_tc) {
2539 		/* Do not allow XPS on subordinate device directly */
2540 		num_tc = dev->num_tc;
2541 		if (num_tc < 0)
2542 			return -EINVAL;
2543 
2544 		/* If queue belongs to subordinate dev use its map */
2545 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2546 
2547 		tc = netdev_txq_to_tc(dev, index);
2548 		if (tc < 0)
2549 			return -EINVAL;
2550 	}
2551 
2552 	mutex_lock(&xps_map_mutex);
2553 
2554 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2555 	if (type == XPS_RXQS) {
2556 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2557 		nr_ids = dev->num_rx_queues;
2558 	} else {
2559 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2560 		if (num_possible_cpus() > 1)
2561 			online_mask = cpumask_bits(cpu_online_mask);
2562 		nr_ids = nr_cpu_ids;
2563 	}
2564 
2565 	if (maps_sz < L1_CACHE_BYTES)
2566 		maps_sz = L1_CACHE_BYTES;
2567 
2568 	/* The old dev_maps could be larger or smaller than the one we're
2569 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2570 	 * between. We could try to be smart, but let's be safe instead and only
2571 	 * copy foreign traffic classes if the two map sizes match.
2572 	 */
2573 	if (dev_maps &&
2574 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2575 		copy = true;
2576 
2577 	/* allocate memory for queue storage */
2578 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2579 	     j < nr_ids;) {
2580 		if (!new_dev_maps) {
2581 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2582 			if (!new_dev_maps) {
2583 				mutex_unlock(&xps_map_mutex);
2584 				return -ENOMEM;
2585 			}
2586 
2587 			new_dev_maps->nr_ids = nr_ids;
2588 			new_dev_maps->num_tc = num_tc;
2589 		}
2590 
2591 		tci = j * num_tc + tc;
2592 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2593 
2594 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2595 		if (!map)
2596 			goto error;
2597 
2598 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2599 	}
2600 
2601 	if (!new_dev_maps)
2602 		goto out_no_new_maps;
2603 
2604 	if (!dev_maps) {
2605 		/* Increment static keys at most once per type */
2606 		static_key_slow_inc_cpuslocked(&xps_needed);
2607 		if (type == XPS_RXQS)
2608 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2609 	}
2610 
2611 	for (j = 0; j < nr_ids; j++) {
2612 		bool skip_tc = false;
2613 
2614 		tci = j * num_tc + tc;
2615 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2616 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2617 			/* add tx-queue to CPU/rx-queue maps */
2618 			int pos = 0;
2619 
2620 			skip_tc = true;
2621 
2622 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2623 			while ((pos < map->len) && (map->queues[pos] != index))
2624 				pos++;
2625 
2626 			if (pos == map->len)
2627 				map->queues[map->len++] = index;
2628 #ifdef CONFIG_NUMA
2629 			if (type == XPS_CPUS) {
2630 				if (numa_node_id == -2)
2631 					numa_node_id = cpu_to_node(j);
2632 				else if (numa_node_id != cpu_to_node(j))
2633 					numa_node_id = -1;
2634 			}
2635 #endif
2636 		}
2637 
2638 		if (copy)
2639 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2640 					  skip_tc);
2641 	}
2642 
2643 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2644 
2645 	/* Cleanup old maps */
2646 	if (!dev_maps)
2647 		goto out_no_old_maps;
2648 
2649 	for (j = 0; j < dev_maps->nr_ids; j++) {
2650 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2651 			map = xmap_dereference(dev_maps->attr_map[tci]);
2652 			if (!map)
2653 				continue;
2654 
2655 			if (copy) {
2656 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2657 				if (map == new_map)
2658 					continue;
2659 			}
2660 
2661 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2662 			kfree_rcu(map, rcu);
2663 		}
2664 	}
2665 
2666 	old_dev_maps = dev_maps;
2667 
2668 out_no_old_maps:
2669 	dev_maps = new_dev_maps;
2670 	active = true;
2671 
2672 out_no_new_maps:
2673 	if (type == XPS_CPUS)
2674 		/* update Tx queue numa node */
2675 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2676 					     (numa_node_id >= 0) ?
2677 					     numa_node_id : NUMA_NO_NODE);
2678 
2679 	if (!dev_maps)
2680 		goto out_no_maps;
2681 
2682 	/* removes tx-queue from unused CPUs/rx-queues */
2683 	for (j = 0; j < dev_maps->nr_ids; j++) {
2684 		tci = j * dev_maps->num_tc;
2685 
2686 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2687 			if (i == tc &&
2688 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2689 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2690 				continue;
2691 
2692 			active |= remove_xps_queue(dev_maps,
2693 						   copy ? old_dev_maps : NULL,
2694 						   tci, index);
2695 		}
2696 	}
2697 
2698 	if (old_dev_maps)
2699 		kfree_rcu(old_dev_maps, rcu);
2700 
2701 	/* free map if not active */
2702 	if (!active)
2703 		reset_xps_maps(dev, dev_maps, type);
2704 
2705 out_no_maps:
2706 	mutex_unlock(&xps_map_mutex);
2707 
2708 	return 0;
2709 error:
2710 	/* remove any maps that we added */
2711 	for (j = 0; j < nr_ids; j++) {
2712 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2713 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2714 			map = copy ?
2715 			      xmap_dereference(dev_maps->attr_map[tci]) :
2716 			      NULL;
2717 			if (new_map && new_map != map)
2718 				kfree(new_map);
2719 		}
2720 	}
2721 
2722 	mutex_unlock(&xps_map_mutex);
2723 
2724 	kfree(new_dev_maps);
2725 	return -ENOMEM;
2726 }
2727 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2728 
2729 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2730 			u16 index)
2731 {
2732 	int ret;
2733 
2734 	cpus_read_lock();
2735 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2736 	cpus_read_unlock();
2737 
2738 	return ret;
2739 }
2740 EXPORT_SYMBOL(netif_set_xps_queue);
2741 
2742 #endif
2743 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2744 {
2745 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2746 
2747 	/* Unbind any subordinate channels */
2748 	while (txq-- != &dev->_tx[0]) {
2749 		if (txq->sb_dev)
2750 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2751 	}
2752 }
2753 
2754 void netdev_reset_tc(struct net_device *dev)
2755 {
2756 #ifdef CONFIG_XPS
2757 	netif_reset_xps_queues_gt(dev, 0);
2758 #endif
2759 	netdev_unbind_all_sb_channels(dev);
2760 
2761 	/* Reset TC configuration of device */
2762 	dev->num_tc = 0;
2763 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2764 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2765 }
2766 EXPORT_SYMBOL(netdev_reset_tc);
2767 
2768 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2769 {
2770 	if (tc >= dev->num_tc)
2771 		return -EINVAL;
2772 
2773 #ifdef CONFIG_XPS
2774 	netif_reset_xps_queues(dev, offset, count);
2775 #endif
2776 	dev->tc_to_txq[tc].count = count;
2777 	dev->tc_to_txq[tc].offset = offset;
2778 	return 0;
2779 }
2780 EXPORT_SYMBOL(netdev_set_tc_queue);
2781 
2782 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2783 {
2784 	if (num_tc > TC_MAX_QUEUE)
2785 		return -EINVAL;
2786 
2787 #ifdef CONFIG_XPS
2788 	netif_reset_xps_queues_gt(dev, 0);
2789 #endif
2790 	netdev_unbind_all_sb_channels(dev);
2791 
2792 	dev->num_tc = num_tc;
2793 	return 0;
2794 }
2795 EXPORT_SYMBOL(netdev_set_num_tc);
2796 
2797 void netdev_unbind_sb_channel(struct net_device *dev,
2798 			      struct net_device *sb_dev)
2799 {
2800 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2801 
2802 #ifdef CONFIG_XPS
2803 	netif_reset_xps_queues_gt(sb_dev, 0);
2804 #endif
2805 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2806 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2807 
2808 	while (txq-- != &dev->_tx[0]) {
2809 		if (txq->sb_dev == sb_dev)
2810 			txq->sb_dev = NULL;
2811 	}
2812 }
2813 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2814 
2815 int netdev_bind_sb_channel_queue(struct net_device *dev,
2816 				 struct net_device *sb_dev,
2817 				 u8 tc, u16 count, u16 offset)
2818 {
2819 	/* Make certain the sb_dev and dev are already configured */
2820 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2821 		return -EINVAL;
2822 
2823 	/* We cannot hand out queues we don't have */
2824 	if ((offset + count) > dev->real_num_tx_queues)
2825 		return -EINVAL;
2826 
2827 	/* Record the mapping */
2828 	sb_dev->tc_to_txq[tc].count = count;
2829 	sb_dev->tc_to_txq[tc].offset = offset;
2830 
2831 	/* Provide a way for Tx queue to find the tc_to_txq map or
2832 	 * XPS map for itself.
2833 	 */
2834 	while (count--)
2835 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2836 
2837 	return 0;
2838 }
2839 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2840 
2841 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2842 {
2843 	/* Do not use a multiqueue device to represent a subordinate channel */
2844 	if (netif_is_multiqueue(dev))
2845 		return -ENODEV;
2846 
2847 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2848 	 * Channel 0 is meant to be "native" mode and used only to represent
2849 	 * the main root device. We allow writing 0 to reset the device back
2850 	 * to normal mode after being used as a subordinate channel.
2851 	 */
2852 	if (channel > S16_MAX)
2853 		return -EINVAL;
2854 
2855 	dev->num_tc = -channel;
2856 
2857 	return 0;
2858 }
2859 EXPORT_SYMBOL(netdev_set_sb_channel);
2860 
2861 /*
2862  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2863  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2864  */
2865 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2866 {
2867 	bool disabling;
2868 	int rc;
2869 
2870 	disabling = txq < dev->real_num_tx_queues;
2871 
2872 	if (txq < 1 || txq > dev->num_tx_queues)
2873 		return -EINVAL;
2874 
2875 	if (dev->reg_state == NETREG_REGISTERED ||
2876 	    dev->reg_state == NETREG_UNREGISTERING) {
2877 		ASSERT_RTNL();
2878 
2879 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2880 						  txq);
2881 		if (rc)
2882 			return rc;
2883 
2884 		if (dev->num_tc)
2885 			netif_setup_tc(dev, txq);
2886 
2887 		dev_qdisc_change_real_num_tx(dev, txq);
2888 
2889 		dev->real_num_tx_queues = txq;
2890 
2891 		if (disabling) {
2892 			synchronize_net();
2893 			qdisc_reset_all_tx_gt(dev, txq);
2894 #ifdef CONFIG_XPS
2895 			netif_reset_xps_queues_gt(dev, txq);
2896 #endif
2897 		}
2898 	} else {
2899 		dev->real_num_tx_queues = txq;
2900 	}
2901 
2902 	return 0;
2903 }
2904 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2905 
2906 #ifdef CONFIG_SYSFS
2907 /**
2908  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2909  *	@dev: Network device
2910  *	@rxq: Actual number of RX queues
2911  *
2912  *	This must be called either with the rtnl_lock held or before
2913  *	registration of the net device.  Returns 0 on success, or a
2914  *	negative error code.  If called before registration, it always
2915  *	succeeds.
2916  */
2917 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2918 {
2919 	int rc;
2920 
2921 	if (rxq < 1 || rxq > dev->num_rx_queues)
2922 		return -EINVAL;
2923 
2924 	if (dev->reg_state == NETREG_REGISTERED) {
2925 		ASSERT_RTNL();
2926 
2927 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2928 						  rxq);
2929 		if (rc)
2930 			return rc;
2931 	}
2932 
2933 	dev->real_num_rx_queues = rxq;
2934 	return 0;
2935 }
2936 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2937 #endif
2938 
2939 /**
2940  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2941  *	@dev: Network device
2942  *	@txq: Actual number of TX queues
2943  *	@rxq: Actual number of RX queues
2944  *
2945  *	Set the real number of both TX and RX queues.
2946  *	Does nothing if the number of queues is already correct.
2947  */
2948 int netif_set_real_num_queues(struct net_device *dev,
2949 			      unsigned int txq, unsigned int rxq)
2950 {
2951 	unsigned int old_rxq = dev->real_num_rx_queues;
2952 	int err;
2953 
2954 	if (txq < 1 || txq > dev->num_tx_queues ||
2955 	    rxq < 1 || rxq > dev->num_rx_queues)
2956 		return -EINVAL;
2957 
2958 	/* Start from increases, so the error path only does decreases -
2959 	 * decreases can't fail.
2960 	 */
2961 	if (rxq > dev->real_num_rx_queues) {
2962 		err = netif_set_real_num_rx_queues(dev, rxq);
2963 		if (err)
2964 			return err;
2965 	}
2966 	if (txq > dev->real_num_tx_queues) {
2967 		err = netif_set_real_num_tx_queues(dev, txq);
2968 		if (err)
2969 			goto undo_rx;
2970 	}
2971 	if (rxq < dev->real_num_rx_queues)
2972 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2973 	if (txq < dev->real_num_tx_queues)
2974 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2975 
2976 	return 0;
2977 undo_rx:
2978 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2979 	return err;
2980 }
2981 EXPORT_SYMBOL(netif_set_real_num_queues);
2982 
2983 /**
2984  * netif_set_tso_max_size() - set the max size of TSO frames supported
2985  * @dev:	netdev to update
2986  * @size:	max skb->len of a TSO frame
2987  *
2988  * Set the limit on the size of TSO super-frames the device can handle.
2989  * Unless explicitly set the stack will assume the value of
2990  * %GSO_LEGACY_MAX_SIZE.
2991  */
2992 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
2993 {
2994 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
2995 	if (size < READ_ONCE(dev->gso_max_size))
2996 		netif_set_gso_max_size(dev, size);
2997 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
2998 		netif_set_gso_ipv4_max_size(dev, size);
2999 }
3000 EXPORT_SYMBOL(netif_set_tso_max_size);
3001 
3002 /**
3003  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3004  * @dev:	netdev to update
3005  * @segs:	max number of TCP segments
3006  *
3007  * Set the limit on the number of TCP segments the device can generate from
3008  * a single TSO super-frame.
3009  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3010  */
3011 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3012 {
3013 	dev->tso_max_segs = segs;
3014 	if (segs < READ_ONCE(dev->gso_max_segs))
3015 		netif_set_gso_max_segs(dev, segs);
3016 }
3017 EXPORT_SYMBOL(netif_set_tso_max_segs);
3018 
3019 /**
3020  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3021  * @to:		netdev to update
3022  * @from:	netdev from which to copy the limits
3023  */
3024 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3025 {
3026 	netif_set_tso_max_size(to, from->tso_max_size);
3027 	netif_set_tso_max_segs(to, from->tso_max_segs);
3028 }
3029 EXPORT_SYMBOL(netif_inherit_tso_max);
3030 
3031 /**
3032  * netif_get_num_default_rss_queues - default number of RSS queues
3033  *
3034  * Default value is the number of physical cores if there are only 1 or 2, or
3035  * divided by 2 if there are more.
3036  */
3037 int netif_get_num_default_rss_queues(void)
3038 {
3039 	cpumask_var_t cpus;
3040 	int cpu, count = 0;
3041 
3042 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3043 		return 1;
3044 
3045 	cpumask_copy(cpus, cpu_online_mask);
3046 	for_each_cpu(cpu, cpus) {
3047 		++count;
3048 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3049 	}
3050 	free_cpumask_var(cpus);
3051 
3052 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3053 }
3054 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3055 
3056 static void __netif_reschedule(struct Qdisc *q)
3057 {
3058 	struct softnet_data *sd;
3059 	unsigned long flags;
3060 
3061 	local_irq_save(flags);
3062 	sd = this_cpu_ptr(&softnet_data);
3063 	q->next_sched = NULL;
3064 	*sd->output_queue_tailp = q;
3065 	sd->output_queue_tailp = &q->next_sched;
3066 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3067 	local_irq_restore(flags);
3068 }
3069 
3070 void __netif_schedule(struct Qdisc *q)
3071 {
3072 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3073 		__netif_reschedule(q);
3074 }
3075 EXPORT_SYMBOL(__netif_schedule);
3076 
3077 struct dev_kfree_skb_cb {
3078 	enum skb_drop_reason reason;
3079 };
3080 
3081 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3082 {
3083 	return (struct dev_kfree_skb_cb *)skb->cb;
3084 }
3085 
3086 void netif_schedule_queue(struct netdev_queue *txq)
3087 {
3088 	rcu_read_lock();
3089 	if (!netif_xmit_stopped(txq)) {
3090 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3091 
3092 		__netif_schedule(q);
3093 	}
3094 	rcu_read_unlock();
3095 }
3096 EXPORT_SYMBOL(netif_schedule_queue);
3097 
3098 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3099 {
3100 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3101 		struct Qdisc *q;
3102 
3103 		rcu_read_lock();
3104 		q = rcu_dereference(dev_queue->qdisc);
3105 		__netif_schedule(q);
3106 		rcu_read_unlock();
3107 	}
3108 }
3109 EXPORT_SYMBOL(netif_tx_wake_queue);
3110 
3111 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3112 {
3113 	unsigned long flags;
3114 
3115 	if (unlikely(!skb))
3116 		return;
3117 
3118 	if (likely(refcount_read(&skb->users) == 1)) {
3119 		smp_rmb();
3120 		refcount_set(&skb->users, 0);
3121 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3122 		return;
3123 	}
3124 	get_kfree_skb_cb(skb)->reason = reason;
3125 	local_irq_save(flags);
3126 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3127 	__this_cpu_write(softnet_data.completion_queue, skb);
3128 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3129 	local_irq_restore(flags);
3130 }
3131 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3132 
3133 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3134 {
3135 	if (in_hardirq() || irqs_disabled())
3136 		dev_kfree_skb_irq_reason(skb, reason);
3137 	else
3138 		kfree_skb_reason(skb, reason);
3139 }
3140 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3141 
3142 
3143 /**
3144  * netif_device_detach - mark device as removed
3145  * @dev: network device
3146  *
3147  * Mark device as removed from system and therefore no longer available.
3148  */
3149 void netif_device_detach(struct net_device *dev)
3150 {
3151 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3152 	    netif_running(dev)) {
3153 		netif_tx_stop_all_queues(dev);
3154 	}
3155 }
3156 EXPORT_SYMBOL(netif_device_detach);
3157 
3158 /**
3159  * netif_device_attach - mark device as attached
3160  * @dev: network device
3161  *
3162  * Mark device as attached from system and restart if needed.
3163  */
3164 void netif_device_attach(struct net_device *dev)
3165 {
3166 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3167 	    netif_running(dev)) {
3168 		netif_tx_wake_all_queues(dev);
3169 		__netdev_watchdog_up(dev);
3170 	}
3171 }
3172 EXPORT_SYMBOL(netif_device_attach);
3173 
3174 /*
3175  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3176  * to be used as a distribution range.
3177  */
3178 static u16 skb_tx_hash(const struct net_device *dev,
3179 		       const struct net_device *sb_dev,
3180 		       struct sk_buff *skb)
3181 {
3182 	u32 hash;
3183 	u16 qoffset = 0;
3184 	u16 qcount = dev->real_num_tx_queues;
3185 
3186 	if (dev->num_tc) {
3187 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3188 
3189 		qoffset = sb_dev->tc_to_txq[tc].offset;
3190 		qcount = sb_dev->tc_to_txq[tc].count;
3191 		if (unlikely(!qcount)) {
3192 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3193 					     sb_dev->name, qoffset, tc);
3194 			qoffset = 0;
3195 			qcount = dev->real_num_tx_queues;
3196 		}
3197 	}
3198 
3199 	if (skb_rx_queue_recorded(skb)) {
3200 		DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3201 		hash = skb_get_rx_queue(skb);
3202 		if (hash >= qoffset)
3203 			hash -= qoffset;
3204 		while (unlikely(hash >= qcount))
3205 			hash -= qcount;
3206 		return hash + qoffset;
3207 	}
3208 
3209 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3210 }
3211 
3212 static void skb_warn_bad_offload(const struct sk_buff *skb)
3213 {
3214 	static const netdev_features_t null_features;
3215 	struct net_device *dev = skb->dev;
3216 	const char *name = "";
3217 
3218 	if (!net_ratelimit())
3219 		return;
3220 
3221 	if (dev) {
3222 		if (dev->dev.parent)
3223 			name = dev_driver_string(dev->dev.parent);
3224 		else
3225 			name = netdev_name(dev);
3226 	}
3227 	skb_dump(KERN_WARNING, skb, false);
3228 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3229 	     name, dev ? &dev->features : &null_features,
3230 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3231 }
3232 
3233 /*
3234  * Invalidate hardware checksum when packet is to be mangled, and
3235  * complete checksum manually on outgoing path.
3236  */
3237 int skb_checksum_help(struct sk_buff *skb)
3238 {
3239 	__wsum csum;
3240 	int ret = 0, offset;
3241 
3242 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3243 		goto out_set_summed;
3244 
3245 	if (unlikely(skb_is_gso(skb))) {
3246 		skb_warn_bad_offload(skb);
3247 		return -EINVAL;
3248 	}
3249 
3250 	/* Before computing a checksum, we should make sure no frag could
3251 	 * be modified by an external entity : checksum could be wrong.
3252 	 */
3253 	if (skb_has_shared_frag(skb)) {
3254 		ret = __skb_linearize(skb);
3255 		if (ret)
3256 			goto out;
3257 	}
3258 
3259 	offset = skb_checksum_start_offset(skb);
3260 	ret = -EINVAL;
3261 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3262 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3263 		goto out;
3264 	}
3265 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3266 
3267 	offset += skb->csum_offset;
3268 	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3269 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3270 		goto out;
3271 	}
3272 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3273 	if (ret)
3274 		goto out;
3275 
3276 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3277 out_set_summed:
3278 	skb->ip_summed = CHECKSUM_NONE;
3279 out:
3280 	return ret;
3281 }
3282 EXPORT_SYMBOL(skb_checksum_help);
3283 
3284 int skb_crc32c_csum_help(struct sk_buff *skb)
3285 {
3286 	__le32 crc32c_csum;
3287 	int ret = 0, offset, start;
3288 
3289 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3290 		goto out;
3291 
3292 	if (unlikely(skb_is_gso(skb)))
3293 		goto out;
3294 
3295 	/* Before computing a checksum, we should make sure no frag could
3296 	 * be modified by an external entity : checksum could be wrong.
3297 	 */
3298 	if (unlikely(skb_has_shared_frag(skb))) {
3299 		ret = __skb_linearize(skb);
3300 		if (ret)
3301 			goto out;
3302 	}
3303 	start = skb_checksum_start_offset(skb);
3304 	offset = start + offsetof(struct sctphdr, checksum);
3305 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3306 		ret = -EINVAL;
3307 		goto out;
3308 	}
3309 
3310 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3311 	if (ret)
3312 		goto out;
3313 
3314 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3315 						  skb->len - start, ~(__u32)0,
3316 						  crc32c_csum_stub));
3317 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3318 	skb->ip_summed = CHECKSUM_NONE;
3319 	skb->csum_not_inet = 0;
3320 out:
3321 	return ret;
3322 }
3323 
3324 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3325 {
3326 	__be16 type = skb->protocol;
3327 
3328 	/* Tunnel gso handlers can set protocol to ethernet. */
3329 	if (type == htons(ETH_P_TEB)) {
3330 		struct ethhdr *eth;
3331 
3332 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3333 			return 0;
3334 
3335 		eth = (struct ethhdr *)skb->data;
3336 		type = eth->h_proto;
3337 	}
3338 
3339 	return __vlan_get_protocol(skb, type, depth);
3340 }
3341 
3342 /* openvswitch calls this on rx path, so we need a different check.
3343  */
3344 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3345 {
3346 	if (tx_path)
3347 		return skb->ip_summed != CHECKSUM_PARTIAL &&
3348 		       skb->ip_summed != CHECKSUM_UNNECESSARY;
3349 
3350 	return skb->ip_summed == CHECKSUM_NONE;
3351 }
3352 
3353 /**
3354  *	__skb_gso_segment - Perform segmentation on skb.
3355  *	@skb: buffer to segment
3356  *	@features: features for the output path (see dev->features)
3357  *	@tx_path: whether it is called in TX path
3358  *
3359  *	This function segments the given skb and returns a list of segments.
3360  *
3361  *	It may return NULL if the skb requires no segmentation.  This is
3362  *	only possible when GSO is used for verifying header integrity.
3363  *
3364  *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3365  */
3366 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3367 				  netdev_features_t features, bool tx_path)
3368 {
3369 	struct sk_buff *segs;
3370 
3371 	if (unlikely(skb_needs_check(skb, tx_path))) {
3372 		int err;
3373 
3374 		/* We're going to init ->check field in TCP or UDP header */
3375 		err = skb_cow_head(skb, 0);
3376 		if (err < 0)
3377 			return ERR_PTR(err);
3378 	}
3379 
3380 	/* Only report GSO partial support if it will enable us to
3381 	 * support segmentation on this frame without needing additional
3382 	 * work.
3383 	 */
3384 	if (features & NETIF_F_GSO_PARTIAL) {
3385 		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3386 		struct net_device *dev = skb->dev;
3387 
3388 		partial_features |= dev->features & dev->gso_partial_features;
3389 		if (!skb_gso_ok(skb, features | partial_features))
3390 			features &= ~NETIF_F_GSO_PARTIAL;
3391 	}
3392 
3393 	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3394 		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3395 
3396 	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3397 	SKB_GSO_CB(skb)->encap_level = 0;
3398 
3399 	skb_reset_mac_header(skb);
3400 	skb_reset_mac_len(skb);
3401 
3402 	segs = skb_mac_gso_segment(skb, features);
3403 
3404 	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3405 		skb_warn_bad_offload(skb);
3406 
3407 	return segs;
3408 }
3409 EXPORT_SYMBOL(__skb_gso_segment);
3410 
3411 /* Take action when hardware reception checksum errors are detected. */
3412 #ifdef CONFIG_BUG
3413 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3414 {
3415 	netdev_err(dev, "hw csum failure\n");
3416 	skb_dump(KERN_ERR, skb, true);
3417 	dump_stack();
3418 }
3419 
3420 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3421 {
3422 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3423 }
3424 EXPORT_SYMBOL(netdev_rx_csum_fault);
3425 #endif
3426 
3427 /* XXX: check that highmem exists at all on the given machine. */
3428 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3429 {
3430 #ifdef CONFIG_HIGHMEM
3431 	int i;
3432 
3433 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3434 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3435 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3436 
3437 			if (PageHighMem(skb_frag_page(frag)))
3438 				return 1;
3439 		}
3440 	}
3441 #endif
3442 	return 0;
3443 }
3444 
3445 /* If MPLS offload request, verify we are testing hardware MPLS features
3446  * instead of standard features for the netdev.
3447  */
3448 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3449 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3450 					   netdev_features_t features,
3451 					   __be16 type)
3452 {
3453 	if (eth_p_mpls(type))
3454 		features &= skb->dev->mpls_features;
3455 
3456 	return features;
3457 }
3458 #else
3459 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3460 					   netdev_features_t features,
3461 					   __be16 type)
3462 {
3463 	return features;
3464 }
3465 #endif
3466 
3467 static netdev_features_t harmonize_features(struct sk_buff *skb,
3468 	netdev_features_t features)
3469 {
3470 	__be16 type;
3471 
3472 	type = skb_network_protocol(skb, NULL);
3473 	features = net_mpls_features(skb, features, type);
3474 
3475 	if (skb->ip_summed != CHECKSUM_NONE &&
3476 	    !can_checksum_protocol(features, type)) {
3477 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3478 	}
3479 	if (illegal_highdma(skb->dev, skb))
3480 		features &= ~NETIF_F_SG;
3481 
3482 	return features;
3483 }
3484 
3485 netdev_features_t passthru_features_check(struct sk_buff *skb,
3486 					  struct net_device *dev,
3487 					  netdev_features_t features)
3488 {
3489 	return features;
3490 }
3491 EXPORT_SYMBOL(passthru_features_check);
3492 
3493 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3494 					     struct net_device *dev,
3495 					     netdev_features_t features)
3496 {
3497 	return vlan_features_check(skb, features);
3498 }
3499 
3500 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3501 					    struct net_device *dev,
3502 					    netdev_features_t features)
3503 {
3504 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3505 
3506 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3507 		return features & ~NETIF_F_GSO_MASK;
3508 
3509 	if (!skb_shinfo(skb)->gso_type) {
3510 		skb_warn_bad_offload(skb);
3511 		return features & ~NETIF_F_GSO_MASK;
3512 	}
3513 
3514 	/* Support for GSO partial features requires software
3515 	 * intervention before we can actually process the packets
3516 	 * so we need to strip support for any partial features now
3517 	 * and we can pull them back in after we have partially
3518 	 * segmented the frame.
3519 	 */
3520 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3521 		features &= ~dev->gso_partial_features;
3522 
3523 	/* Make sure to clear the IPv4 ID mangling feature if the
3524 	 * IPv4 header has the potential to be fragmented.
3525 	 */
3526 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3527 		struct iphdr *iph = skb->encapsulation ?
3528 				    inner_ip_hdr(skb) : ip_hdr(skb);
3529 
3530 		if (!(iph->frag_off & htons(IP_DF)))
3531 			features &= ~NETIF_F_TSO_MANGLEID;
3532 	}
3533 
3534 	return features;
3535 }
3536 
3537 netdev_features_t netif_skb_features(struct sk_buff *skb)
3538 {
3539 	struct net_device *dev = skb->dev;
3540 	netdev_features_t features = dev->features;
3541 
3542 	if (skb_is_gso(skb))
3543 		features = gso_features_check(skb, dev, features);
3544 
3545 	/* If encapsulation offload request, verify we are testing
3546 	 * hardware encapsulation features instead of standard
3547 	 * features for the netdev
3548 	 */
3549 	if (skb->encapsulation)
3550 		features &= dev->hw_enc_features;
3551 
3552 	if (skb_vlan_tagged(skb))
3553 		features = netdev_intersect_features(features,
3554 						     dev->vlan_features |
3555 						     NETIF_F_HW_VLAN_CTAG_TX |
3556 						     NETIF_F_HW_VLAN_STAG_TX);
3557 
3558 	if (dev->netdev_ops->ndo_features_check)
3559 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3560 								features);
3561 	else
3562 		features &= dflt_features_check(skb, dev, features);
3563 
3564 	return harmonize_features(skb, features);
3565 }
3566 EXPORT_SYMBOL(netif_skb_features);
3567 
3568 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3569 		    struct netdev_queue *txq, bool more)
3570 {
3571 	unsigned int len;
3572 	int rc;
3573 
3574 	if (dev_nit_active(dev))
3575 		dev_queue_xmit_nit(skb, dev);
3576 
3577 	len = skb->len;
3578 	trace_net_dev_start_xmit(skb, dev);
3579 	rc = netdev_start_xmit(skb, dev, txq, more);
3580 	trace_net_dev_xmit(skb, rc, dev, len);
3581 
3582 	return rc;
3583 }
3584 
3585 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3586 				    struct netdev_queue *txq, int *ret)
3587 {
3588 	struct sk_buff *skb = first;
3589 	int rc = NETDEV_TX_OK;
3590 
3591 	while (skb) {
3592 		struct sk_buff *next = skb->next;
3593 
3594 		skb_mark_not_on_list(skb);
3595 		rc = xmit_one(skb, dev, txq, next != NULL);
3596 		if (unlikely(!dev_xmit_complete(rc))) {
3597 			skb->next = next;
3598 			goto out;
3599 		}
3600 
3601 		skb = next;
3602 		if (netif_tx_queue_stopped(txq) && skb) {
3603 			rc = NETDEV_TX_BUSY;
3604 			break;
3605 		}
3606 	}
3607 
3608 out:
3609 	*ret = rc;
3610 	return skb;
3611 }
3612 
3613 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3614 					  netdev_features_t features)
3615 {
3616 	if (skb_vlan_tag_present(skb) &&
3617 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3618 		skb = __vlan_hwaccel_push_inside(skb);
3619 	return skb;
3620 }
3621 
3622 int skb_csum_hwoffload_help(struct sk_buff *skb,
3623 			    const netdev_features_t features)
3624 {
3625 	if (unlikely(skb_csum_is_sctp(skb)))
3626 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3627 			skb_crc32c_csum_help(skb);
3628 
3629 	if (features & NETIF_F_HW_CSUM)
3630 		return 0;
3631 
3632 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3633 		switch (skb->csum_offset) {
3634 		case offsetof(struct tcphdr, check):
3635 		case offsetof(struct udphdr, check):
3636 			return 0;
3637 		}
3638 	}
3639 
3640 	return skb_checksum_help(skb);
3641 }
3642 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3643 
3644 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3645 {
3646 	netdev_features_t features;
3647 
3648 	features = netif_skb_features(skb);
3649 	skb = validate_xmit_vlan(skb, features);
3650 	if (unlikely(!skb))
3651 		goto out_null;
3652 
3653 	skb = sk_validate_xmit_skb(skb, dev);
3654 	if (unlikely(!skb))
3655 		goto out_null;
3656 
3657 	if (netif_needs_gso(skb, features)) {
3658 		struct sk_buff *segs;
3659 
3660 		segs = skb_gso_segment(skb, features);
3661 		if (IS_ERR(segs)) {
3662 			goto out_kfree_skb;
3663 		} else if (segs) {
3664 			consume_skb(skb);
3665 			skb = segs;
3666 		}
3667 	} else {
3668 		if (skb_needs_linearize(skb, features) &&
3669 		    __skb_linearize(skb))
3670 			goto out_kfree_skb;
3671 
3672 		/* If packet is not checksummed and device does not
3673 		 * support checksumming for this protocol, complete
3674 		 * checksumming here.
3675 		 */
3676 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3677 			if (skb->encapsulation)
3678 				skb_set_inner_transport_header(skb,
3679 							       skb_checksum_start_offset(skb));
3680 			else
3681 				skb_set_transport_header(skb,
3682 							 skb_checksum_start_offset(skb));
3683 			if (skb_csum_hwoffload_help(skb, features))
3684 				goto out_kfree_skb;
3685 		}
3686 	}
3687 
3688 	skb = validate_xmit_xfrm(skb, features, again);
3689 
3690 	return skb;
3691 
3692 out_kfree_skb:
3693 	kfree_skb(skb);
3694 out_null:
3695 	dev_core_stats_tx_dropped_inc(dev);
3696 	return NULL;
3697 }
3698 
3699 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3700 {
3701 	struct sk_buff *next, *head = NULL, *tail;
3702 
3703 	for (; skb != NULL; skb = next) {
3704 		next = skb->next;
3705 		skb_mark_not_on_list(skb);
3706 
3707 		/* in case skb wont be segmented, point to itself */
3708 		skb->prev = skb;
3709 
3710 		skb = validate_xmit_skb(skb, dev, again);
3711 		if (!skb)
3712 			continue;
3713 
3714 		if (!head)
3715 			head = skb;
3716 		else
3717 			tail->next = skb;
3718 		/* If skb was segmented, skb->prev points to
3719 		 * the last segment. If not, it still contains skb.
3720 		 */
3721 		tail = skb->prev;
3722 	}
3723 	return head;
3724 }
3725 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3726 
3727 static void qdisc_pkt_len_init(struct sk_buff *skb)
3728 {
3729 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3730 
3731 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3732 
3733 	/* To get more precise estimation of bytes sent on wire,
3734 	 * we add to pkt_len the headers size of all segments
3735 	 */
3736 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3737 		u16 gso_segs = shinfo->gso_segs;
3738 		unsigned int hdr_len;
3739 
3740 		/* mac layer + network layer */
3741 		hdr_len = skb_transport_offset(skb);
3742 
3743 		/* + transport layer */
3744 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3745 			const struct tcphdr *th;
3746 			struct tcphdr _tcphdr;
3747 
3748 			th = skb_header_pointer(skb, hdr_len,
3749 						sizeof(_tcphdr), &_tcphdr);
3750 			if (likely(th))
3751 				hdr_len += __tcp_hdrlen(th);
3752 		} else {
3753 			struct udphdr _udphdr;
3754 
3755 			if (skb_header_pointer(skb, hdr_len,
3756 					       sizeof(_udphdr), &_udphdr))
3757 				hdr_len += sizeof(struct udphdr);
3758 		}
3759 
3760 		if (shinfo->gso_type & SKB_GSO_DODGY)
3761 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3762 						shinfo->gso_size);
3763 
3764 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3765 	}
3766 }
3767 
3768 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3769 			     struct sk_buff **to_free,
3770 			     struct netdev_queue *txq)
3771 {
3772 	int rc;
3773 
3774 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3775 	if (rc == NET_XMIT_SUCCESS)
3776 		trace_qdisc_enqueue(q, txq, skb);
3777 	return rc;
3778 }
3779 
3780 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3781 				 struct net_device *dev,
3782 				 struct netdev_queue *txq)
3783 {
3784 	spinlock_t *root_lock = qdisc_lock(q);
3785 	struct sk_buff *to_free = NULL;
3786 	bool contended;
3787 	int rc;
3788 
3789 	qdisc_calculate_pkt_len(skb, q);
3790 
3791 	if (q->flags & TCQ_F_NOLOCK) {
3792 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3793 		    qdisc_run_begin(q)) {
3794 			/* Retest nolock_qdisc_is_empty() within the protection
3795 			 * of q->seqlock to protect from racing with requeuing.
3796 			 */
3797 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3798 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3799 				__qdisc_run(q);
3800 				qdisc_run_end(q);
3801 
3802 				goto no_lock_out;
3803 			}
3804 
3805 			qdisc_bstats_cpu_update(q, skb);
3806 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3807 			    !nolock_qdisc_is_empty(q))
3808 				__qdisc_run(q);
3809 
3810 			qdisc_run_end(q);
3811 			return NET_XMIT_SUCCESS;
3812 		}
3813 
3814 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3815 		qdisc_run(q);
3816 
3817 no_lock_out:
3818 		if (unlikely(to_free))
3819 			kfree_skb_list_reason(to_free,
3820 					      SKB_DROP_REASON_QDISC_DROP);
3821 		return rc;
3822 	}
3823 
3824 	/*
3825 	 * Heuristic to force contended enqueues to serialize on a
3826 	 * separate lock before trying to get qdisc main lock.
3827 	 * This permits qdisc->running owner to get the lock more
3828 	 * often and dequeue packets faster.
3829 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3830 	 * and then other tasks will only enqueue packets. The packets will be
3831 	 * sent after the qdisc owner is scheduled again. To prevent this
3832 	 * scenario the task always serialize on the lock.
3833 	 */
3834 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3835 	if (unlikely(contended))
3836 		spin_lock(&q->busylock);
3837 
3838 	spin_lock(root_lock);
3839 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3840 		__qdisc_drop(skb, &to_free);
3841 		rc = NET_XMIT_DROP;
3842 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3843 		   qdisc_run_begin(q)) {
3844 		/*
3845 		 * This is a work-conserving queue; there are no old skbs
3846 		 * waiting to be sent out; and the qdisc is not running -
3847 		 * xmit the skb directly.
3848 		 */
3849 
3850 		qdisc_bstats_update(q, skb);
3851 
3852 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3853 			if (unlikely(contended)) {
3854 				spin_unlock(&q->busylock);
3855 				contended = false;
3856 			}
3857 			__qdisc_run(q);
3858 		}
3859 
3860 		qdisc_run_end(q);
3861 		rc = NET_XMIT_SUCCESS;
3862 	} else {
3863 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3864 		if (qdisc_run_begin(q)) {
3865 			if (unlikely(contended)) {
3866 				spin_unlock(&q->busylock);
3867 				contended = false;
3868 			}
3869 			__qdisc_run(q);
3870 			qdisc_run_end(q);
3871 		}
3872 	}
3873 	spin_unlock(root_lock);
3874 	if (unlikely(to_free))
3875 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3876 	if (unlikely(contended))
3877 		spin_unlock(&q->busylock);
3878 	return rc;
3879 }
3880 
3881 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3882 static void skb_update_prio(struct sk_buff *skb)
3883 {
3884 	const struct netprio_map *map;
3885 	const struct sock *sk;
3886 	unsigned int prioidx;
3887 
3888 	if (skb->priority)
3889 		return;
3890 	map = rcu_dereference_bh(skb->dev->priomap);
3891 	if (!map)
3892 		return;
3893 	sk = skb_to_full_sk(skb);
3894 	if (!sk)
3895 		return;
3896 
3897 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3898 
3899 	if (prioidx < map->priomap_len)
3900 		skb->priority = map->priomap[prioidx];
3901 }
3902 #else
3903 #define skb_update_prio(skb)
3904 #endif
3905 
3906 /**
3907  *	dev_loopback_xmit - loop back @skb
3908  *	@net: network namespace this loopback is happening in
3909  *	@sk:  sk needed to be a netfilter okfn
3910  *	@skb: buffer to transmit
3911  */
3912 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3913 {
3914 	skb_reset_mac_header(skb);
3915 	__skb_pull(skb, skb_network_offset(skb));
3916 	skb->pkt_type = PACKET_LOOPBACK;
3917 	if (skb->ip_summed == CHECKSUM_NONE)
3918 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3919 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3920 	skb_dst_force(skb);
3921 	netif_rx(skb);
3922 	return 0;
3923 }
3924 EXPORT_SYMBOL(dev_loopback_xmit);
3925 
3926 #ifdef CONFIG_NET_EGRESS
3927 static struct sk_buff *
3928 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3929 {
3930 #ifdef CONFIG_NET_CLS_ACT
3931 	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3932 	struct tcf_result cl_res;
3933 
3934 	if (!miniq)
3935 		return skb;
3936 
3937 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3938 	tc_skb_cb(skb)->mru = 0;
3939 	tc_skb_cb(skb)->post_ct = false;
3940 	mini_qdisc_bstats_cpu_update(miniq, skb);
3941 
3942 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3943 	case TC_ACT_OK:
3944 	case TC_ACT_RECLASSIFY:
3945 		skb->tc_index = TC_H_MIN(cl_res.classid);
3946 		break;
3947 	case TC_ACT_SHOT:
3948 		mini_qdisc_qstats_cpu_drop(miniq);
3949 		*ret = NET_XMIT_DROP;
3950 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3951 		return NULL;
3952 	case TC_ACT_STOLEN:
3953 	case TC_ACT_QUEUED:
3954 	case TC_ACT_TRAP:
3955 		*ret = NET_XMIT_SUCCESS;
3956 		consume_skb(skb);
3957 		return NULL;
3958 	case TC_ACT_REDIRECT:
3959 		/* No need to push/pop skb's mac_header here on egress! */
3960 		skb_do_redirect(skb);
3961 		*ret = NET_XMIT_SUCCESS;
3962 		return NULL;
3963 	default:
3964 		break;
3965 	}
3966 #endif /* CONFIG_NET_CLS_ACT */
3967 
3968 	return skb;
3969 }
3970 
3971 static struct netdev_queue *
3972 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3973 {
3974 	int qm = skb_get_queue_mapping(skb);
3975 
3976 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3977 }
3978 
3979 static bool netdev_xmit_txqueue_skipped(void)
3980 {
3981 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3982 }
3983 
3984 void netdev_xmit_skip_txqueue(bool skip)
3985 {
3986 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3987 }
3988 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3989 #endif /* CONFIG_NET_EGRESS */
3990 
3991 #ifdef CONFIG_XPS
3992 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3993 			       struct xps_dev_maps *dev_maps, unsigned int tci)
3994 {
3995 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
3996 	struct xps_map *map;
3997 	int queue_index = -1;
3998 
3999 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4000 		return queue_index;
4001 
4002 	tci *= dev_maps->num_tc;
4003 	tci += tc;
4004 
4005 	map = rcu_dereference(dev_maps->attr_map[tci]);
4006 	if (map) {
4007 		if (map->len == 1)
4008 			queue_index = map->queues[0];
4009 		else
4010 			queue_index = map->queues[reciprocal_scale(
4011 						skb_get_hash(skb), map->len)];
4012 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4013 			queue_index = -1;
4014 	}
4015 	return queue_index;
4016 }
4017 #endif
4018 
4019 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4020 			 struct sk_buff *skb)
4021 {
4022 #ifdef CONFIG_XPS
4023 	struct xps_dev_maps *dev_maps;
4024 	struct sock *sk = skb->sk;
4025 	int queue_index = -1;
4026 
4027 	if (!static_key_false(&xps_needed))
4028 		return -1;
4029 
4030 	rcu_read_lock();
4031 	if (!static_key_false(&xps_rxqs_needed))
4032 		goto get_cpus_map;
4033 
4034 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4035 	if (dev_maps) {
4036 		int tci = sk_rx_queue_get(sk);
4037 
4038 		if (tci >= 0)
4039 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4040 							  tci);
4041 	}
4042 
4043 get_cpus_map:
4044 	if (queue_index < 0) {
4045 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4046 		if (dev_maps) {
4047 			unsigned int tci = skb->sender_cpu - 1;
4048 
4049 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4050 							  tci);
4051 		}
4052 	}
4053 	rcu_read_unlock();
4054 
4055 	return queue_index;
4056 #else
4057 	return -1;
4058 #endif
4059 }
4060 
4061 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4062 		     struct net_device *sb_dev)
4063 {
4064 	return 0;
4065 }
4066 EXPORT_SYMBOL(dev_pick_tx_zero);
4067 
4068 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4069 		       struct net_device *sb_dev)
4070 {
4071 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4072 }
4073 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4074 
4075 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4076 		     struct net_device *sb_dev)
4077 {
4078 	struct sock *sk = skb->sk;
4079 	int queue_index = sk_tx_queue_get(sk);
4080 
4081 	sb_dev = sb_dev ? : dev;
4082 
4083 	if (queue_index < 0 || skb->ooo_okay ||
4084 	    queue_index >= dev->real_num_tx_queues) {
4085 		int new_index = get_xps_queue(dev, sb_dev, skb);
4086 
4087 		if (new_index < 0)
4088 			new_index = skb_tx_hash(dev, sb_dev, skb);
4089 
4090 		if (queue_index != new_index && sk &&
4091 		    sk_fullsock(sk) &&
4092 		    rcu_access_pointer(sk->sk_dst_cache))
4093 			sk_tx_queue_set(sk, new_index);
4094 
4095 		queue_index = new_index;
4096 	}
4097 
4098 	return queue_index;
4099 }
4100 EXPORT_SYMBOL(netdev_pick_tx);
4101 
4102 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4103 					 struct sk_buff *skb,
4104 					 struct net_device *sb_dev)
4105 {
4106 	int queue_index = 0;
4107 
4108 #ifdef CONFIG_XPS
4109 	u32 sender_cpu = skb->sender_cpu - 1;
4110 
4111 	if (sender_cpu >= (u32)NR_CPUS)
4112 		skb->sender_cpu = raw_smp_processor_id() + 1;
4113 #endif
4114 
4115 	if (dev->real_num_tx_queues != 1) {
4116 		const struct net_device_ops *ops = dev->netdev_ops;
4117 
4118 		if (ops->ndo_select_queue)
4119 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4120 		else
4121 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4122 
4123 		queue_index = netdev_cap_txqueue(dev, queue_index);
4124 	}
4125 
4126 	skb_set_queue_mapping(skb, queue_index);
4127 	return netdev_get_tx_queue(dev, queue_index);
4128 }
4129 
4130 /**
4131  * __dev_queue_xmit() - transmit a buffer
4132  * @skb:	buffer to transmit
4133  * @sb_dev:	suboordinate device used for L2 forwarding offload
4134  *
4135  * Queue a buffer for transmission to a network device. The caller must
4136  * have set the device and priority and built the buffer before calling
4137  * this function. The function can be called from an interrupt.
4138  *
4139  * When calling this method, interrupts MUST be enabled. This is because
4140  * the BH enable code must have IRQs enabled so that it will not deadlock.
4141  *
4142  * Regardless of the return value, the skb is consumed, so it is currently
4143  * difficult to retry a send to this method. (You can bump the ref count
4144  * before sending to hold a reference for retry if you are careful.)
4145  *
4146  * Return:
4147  * * 0				- buffer successfully transmitted
4148  * * positive qdisc return code	- NET_XMIT_DROP etc.
4149  * * negative errno		- other errors
4150  */
4151 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4152 {
4153 	struct net_device *dev = skb->dev;
4154 	struct netdev_queue *txq = NULL;
4155 	struct Qdisc *q;
4156 	int rc = -ENOMEM;
4157 	bool again = false;
4158 
4159 	skb_reset_mac_header(skb);
4160 	skb_assert_len(skb);
4161 
4162 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4163 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4164 
4165 	/* Disable soft irqs for various locks below. Also
4166 	 * stops preemption for RCU.
4167 	 */
4168 	rcu_read_lock_bh();
4169 
4170 	skb_update_prio(skb);
4171 
4172 	qdisc_pkt_len_init(skb);
4173 #ifdef CONFIG_NET_CLS_ACT
4174 	skb->tc_at_ingress = 0;
4175 #endif
4176 #ifdef CONFIG_NET_EGRESS
4177 	if (static_branch_unlikely(&egress_needed_key)) {
4178 		if (nf_hook_egress_active()) {
4179 			skb = nf_hook_egress(skb, &rc, dev);
4180 			if (!skb)
4181 				goto out;
4182 		}
4183 
4184 		netdev_xmit_skip_txqueue(false);
4185 
4186 		nf_skip_egress(skb, true);
4187 		skb = sch_handle_egress(skb, &rc, dev);
4188 		if (!skb)
4189 			goto out;
4190 		nf_skip_egress(skb, false);
4191 
4192 		if (netdev_xmit_txqueue_skipped())
4193 			txq = netdev_tx_queue_mapping(dev, skb);
4194 	}
4195 #endif
4196 	/* If device/qdisc don't need skb->dst, release it right now while
4197 	 * its hot in this cpu cache.
4198 	 */
4199 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4200 		skb_dst_drop(skb);
4201 	else
4202 		skb_dst_force(skb);
4203 
4204 	if (!txq)
4205 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4206 
4207 	q = rcu_dereference_bh(txq->qdisc);
4208 
4209 	trace_net_dev_queue(skb);
4210 	if (q->enqueue) {
4211 		rc = __dev_xmit_skb(skb, q, dev, txq);
4212 		goto out;
4213 	}
4214 
4215 	/* The device has no queue. Common case for software devices:
4216 	 * loopback, all the sorts of tunnels...
4217 
4218 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4219 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4220 	 * counters.)
4221 	 * However, it is possible, that they rely on protection
4222 	 * made by us here.
4223 
4224 	 * Check this and shot the lock. It is not prone from deadlocks.
4225 	 *Either shot noqueue qdisc, it is even simpler 8)
4226 	 */
4227 	if (dev->flags & IFF_UP) {
4228 		int cpu = smp_processor_id(); /* ok because BHs are off */
4229 
4230 		/* Other cpus might concurrently change txq->xmit_lock_owner
4231 		 * to -1 or to their cpu id, but not to our id.
4232 		 */
4233 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4234 			if (dev_xmit_recursion())
4235 				goto recursion_alert;
4236 
4237 			skb = validate_xmit_skb(skb, dev, &again);
4238 			if (!skb)
4239 				goto out;
4240 
4241 			HARD_TX_LOCK(dev, txq, cpu);
4242 
4243 			if (!netif_xmit_stopped(txq)) {
4244 				dev_xmit_recursion_inc();
4245 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4246 				dev_xmit_recursion_dec();
4247 				if (dev_xmit_complete(rc)) {
4248 					HARD_TX_UNLOCK(dev, txq);
4249 					goto out;
4250 				}
4251 			}
4252 			HARD_TX_UNLOCK(dev, txq);
4253 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4254 					     dev->name);
4255 		} else {
4256 			/* Recursion is detected! It is possible,
4257 			 * unfortunately
4258 			 */
4259 recursion_alert:
4260 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4261 					     dev->name);
4262 		}
4263 	}
4264 
4265 	rc = -ENETDOWN;
4266 	rcu_read_unlock_bh();
4267 
4268 	dev_core_stats_tx_dropped_inc(dev);
4269 	kfree_skb_list(skb);
4270 	return rc;
4271 out:
4272 	rcu_read_unlock_bh();
4273 	return rc;
4274 }
4275 EXPORT_SYMBOL(__dev_queue_xmit);
4276 
4277 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4278 {
4279 	struct net_device *dev = skb->dev;
4280 	struct sk_buff *orig_skb = skb;
4281 	struct netdev_queue *txq;
4282 	int ret = NETDEV_TX_BUSY;
4283 	bool again = false;
4284 
4285 	if (unlikely(!netif_running(dev) ||
4286 		     !netif_carrier_ok(dev)))
4287 		goto drop;
4288 
4289 	skb = validate_xmit_skb_list(skb, dev, &again);
4290 	if (skb != orig_skb)
4291 		goto drop;
4292 
4293 	skb_set_queue_mapping(skb, queue_id);
4294 	txq = skb_get_tx_queue(dev, skb);
4295 
4296 	local_bh_disable();
4297 
4298 	dev_xmit_recursion_inc();
4299 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4300 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4301 		ret = netdev_start_xmit(skb, dev, txq, false);
4302 	HARD_TX_UNLOCK(dev, txq);
4303 	dev_xmit_recursion_dec();
4304 
4305 	local_bh_enable();
4306 	return ret;
4307 drop:
4308 	dev_core_stats_tx_dropped_inc(dev);
4309 	kfree_skb_list(skb);
4310 	return NET_XMIT_DROP;
4311 }
4312 EXPORT_SYMBOL(__dev_direct_xmit);
4313 
4314 /*************************************************************************
4315  *			Receiver routines
4316  *************************************************************************/
4317 
4318 int netdev_max_backlog __read_mostly = 1000;
4319 EXPORT_SYMBOL(netdev_max_backlog);
4320 
4321 int netdev_tstamp_prequeue __read_mostly = 1;
4322 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4323 int netdev_budget __read_mostly = 300;
4324 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4325 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4326 int weight_p __read_mostly = 64;           /* old backlog weight */
4327 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4328 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4329 int dev_rx_weight __read_mostly = 64;
4330 int dev_tx_weight __read_mostly = 64;
4331 
4332 /* Called with irq disabled */
4333 static inline void ____napi_schedule(struct softnet_data *sd,
4334 				     struct napi_struct *napi)
4335 {
4336 	struct task_struct *thread;
4337 
4338 	lockdep_assert_irqs_disabled();
4339 
4340 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4341 		/* Paired with smp_mb__before_atomic() in
4342 		 * napi_enable()/dev_set_threaded().
4343 		 * Use READ_ONCE() to guarantee a complete
4344 		 * read on napi->thread. Only call
4345 		 * wake_up_process() when it's not NULL.
4346 		 */
4347 		thread = READ_ONCE(napi->thread);
4348 		if (thread) {
4349 			/* Avoid doing set_bit() if the thread is in
4350 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4351 			 * makes sure to proceed with napi polling
4352 			 * if the thread is explicitly woken from here.
4353 			 */
4354 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4355 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4356 			wake_up_process(thread);
4357 			return;
4358 		}
4359 	}
4360 
4361 	list_add_tail(&napi->poll_list, &sd->poll_list);
4362 	WRITE_ONCE(napi->list_owner, smp_processor_id());
4363 	/* If not called from net_rx_action()
4364 	 * we have to raise NET_RX_SOFTIRQ.
4365 	 */
4366 	if (!sd->in_net_rx_action)
4367 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4368 }
4369 
4370 #ifdef CONFIG_RPS
4371 
4372 /* One global table that all flow-based protocols share. */
4373 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4374 EXPORT_SYMBOL(rps_sock_flow_table);
4375 u32 rps_cpu_mask __read_mostly;
4376 EXPORT_SYMBOL(rps_cpu_mask);
4377 
4378 struct static_key_false rps_needed __read_mostly;
4379 EXPORT_SYMBOL(rps_needed);
4380 struct static_key_false rfs_needed __read_mostly;
4381 EXPORT_SYMBOL(rfs_needed);
4382 
4383 static struct rps_dev_flow *
4384 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4385 	    struct rps_dev_flow *rflow, u16 next_cpu)
4386 {
4387 	if (next_cpu < nr_cpu_ids) {
4388 #ifdef CONFIG_RFS_ACCEL
4389 		struct netdev_rx_queue *rxqueue;
4390 		struct rps_dev_flow_table *flow_table;
4391 		struct rps_dev_flow *old_rflow;
4392 		u32 flow_id;
4393 		u16 rxq_index;
4394 		int rc;
4395 
4396 		/* Should we steer this flow to a different hardware queue? */
4397 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4398 		    !(dev->features & NETIF_F_NTUPLE))
4399 			goto out;
4400 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4401 		if (rxq_index == skb_get_rx_queue(skb))
4402 			goto out;
4403 
4404 		rxqueue = dev->_rx + rxq_index;
4405 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4406 		if (!flow_table)
4407 			goto out;
4408 		flow_id = skb_get_hash(skb) & flow_table->mask;
4409 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4410 							rxq_index, flow_id);
4411 		if (rc < 0)
4412 			goto out;
4413 		old_rflow = rflow;
4414 		rflow = &flow_table->flows[flow_id];
4415 		rflow->filter = rc;
4416 		if (old_rflow->filter == rflow->filter)
4417 			old_rflow->filter = RPS_NO_FILTER;
4418 	out:
4419 #endif
4420 		rflow->last_qtail =
4421 			per_cpu(softnet_data, next_cpu).input_queue_head;
4422 	}
4423 
4424 	rflow->cpu = next_cpu;
4425 	return rflow;
4426 }
4427 
4428 /*
4429  * get_rps_cpu is called from netif_receive_skb and returns the target
4430  * CPU from the RPS map of the receiving queue for a given skb.
4431  * rcu_read_lock must be held on entry.
4432  */
4433 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4434 		       struct rps_dev_flow **rflowp)
4435 {
4436 	const struct rps_sock_flow_table *sock_flow_table;
4437 	struct netdev_rx_queue *rxqueue = dev->_rx;
4438 	struct rps_dev_flow_table *flow_table;
4439 	struct rps_map *map;
4440 	int cpu = -1;
4441 	u32 tcpu;
4442 	u32 hash;
4443 
4444 	if (skb_rx_queue_recorded(skb)) {
4445 		u16 index = skb_get_rx_queue(skb);
4446 
4447 		if (unlikely(index >= dev->real_num_rx_queues)) {
4448 			WARN_ONCE(dev->real_num_rx_queues > 1,
4449 				  "%s received packet on queue %u, but number "
4450 				  "of RX queues is %u\n",
4451 				  dev->name, index, dev->real_num_rx_queues);
4452 			goto done;
4453 		}
4454 		rxqueue += index;
4455 	}
4456 
4457 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4458 
4459 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4460 	map = rcu_dereference(rxqueue->rps_map);
4461 	if (!flow_table && !map)
4462 		goto done;
4463 
4464 	skb_reset_network_header(skb);
4465 	hash = skb_get_hash(skb);
4466 	if (!hash)
4467 		goto done;
4468 
4469 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4470 	if (flow_table && sock_flow_table) {
4471 		struct rps_dev_flow *rflow;
4472 		u32 next_cpu;
4473 		u32 ident;
4474 
4475 		/* First check into global flow table if there is a match */
4476 		ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4477 		if ((ident ^ hash) & ~rps_cpu_mask)
4478 			goto try_rps;
4479 
4480 		next_cpu = ident & rps_cpu_mask;
4481 
4482 		/* OK, now we know there is a match,
4483 		 * we can look at the local (per receive queue) flow table
4484 		 */
4485 		rflow = &flow_table->flows[hash & flow_table->mask];
4486 		tcpu = rflow->cpu;
4487 
4488 		/*
4489 		 * If the desired CPU (where last recvmsg was done) is
4490 		 * different from current CPU (one in the rx-queue flow
4491 		 * table entry), switch if one of the following holds:
4492 		 *   - Current CPU is unset (>= nr_cpu_ids).
4493 		 *   - Current CPU is offline.
4494 		 *   - The current CPU's queue tail has advanced beyond the
4495 		 *     last packet that was enqueued using this table entry.
4496 		 *     This guarantees that all previous packets for the flow
4497 		 *     have been dequeued, thus preserving in order delivery.
4498 		 */
4499 		if (unlikely(tcpu != next_cpu) &&
4500 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4501 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4502 		      rflow->last_qtail)) >= 0)) {
4503 			tcpu = next_cpu;
4504 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4505 		}
4506 
4507 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4508 			*rflowp = rflow;
4509 			cpu = tcpu;
4510 			goto done;
4511 		}
4512 	}
4513 
4514 try_rps:
4515 
4516 	if (map) {
4517 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4518 		if (cpu_online(tcpu)) {
4519 			cpu = tcpu;
4520 			goto done;
4521 		}
4522 	}
4523 
4524 done:
4525 	return cpu;
4526 }
4527 
4528 #ifdef CONFIG_RFS_ACCEL
4529 
4530 /**
4531  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4532  * @dev: Device on which the filter was set
4533  * @rxq_index: RX queue index
4534  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4535  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4536  *
4537  * Drivers that implement ndo_rx_flow_steer() should periodically call
4538  * this function for each installed filter and remove the filters for
4539  * which it returns %true.
4540  */
4541 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4542 			 u32 flow_id, u16 filter_id)
4543 {
4544 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4545 	struct rps_dev_flow_table *flow_table;
4546 	struct rps_dev_flow *rflow;
4547 	bool expire = true;
4548 	unsigned int cpu;
4549 
4550 	rcu_read_lock();
4551 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4552 	if (flow_table && flow_id <= flow_table->mask) {
4553 		rflow = &flow_table->flows[flow_id];
4554 		cpu = READ_ONCE(rflow->cpu);
4555 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4556 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4557 			   rflow->last_qtail) <
4558 		     (int)(10 * flow_table->mask)))
4559 			expire = false;
4560 	}
4561 	rcu_read_unlock();
4562 	return expire;
4563 }
4564 EXPORT_SYMBOL(rps_may_expire_flow);
4565 
4566 #endif /* CONFIG_RFS_ACCEL */
4567 
4568 /* Called from hardirq (IPI) context */
4569 static void rps_trigger_softirq(void *data)
4570 {
4571 	struct softnet_data *sd = data;
4572 
4573 	____napi_schedule(sd, &sd->backlog);
4574 	sd->received_rps++;
4575 }
4576 
4577 #endif /* CONFIG_RPS */
4578 
4579 /* Called from hardirq (IPI) context */
4580 static void trigger_rx_softirq(void *data)
4581 {
4582 	struct softnet_data *sd = data;
4583 
4584 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4585 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4586 }
4587 
4588 /*
4589  * After we queued a packet into sd->input_pkt_queue,
4590  * we need to make sure this queue is serviced soon.
4591  *
4592  * - If this is another cpu queue, link it to our rps_ipi_list,
4593  *   and make sure we will process rps_ipi_list from net_rx_action().
4594  *
4595  * - If this is our own queue, NAPI schedule our backlog.
4596  *   Note that this also raises NET_RX_SOFTIRQ.
4597  */
4598 static void napi_schedule_rps(struct softnet_data *sd)
4599 {
4600 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4601 
4602 #ifdef CONFIG_RPS
4603 	if (sd != mysd) {
4604 		sd->rps_ipi_next = mysd->rps_ipi_list;
4605 		mysd->rps_ipi_list = sd;
4606 
4607 		/* If not called from net_rx_action()
4608 		 * we have to raise NET_RX_SOFTIRQ.
4609 		 */
4610 		if (!mysd->in_net_rx_action)
4611 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4612 		return;
4613 	}
4614 #endif /* CONFIG_RPS */
4615 	__napi_schedule_irqoff(&mysd->backlog);
4616 }
4617 
4618 #ifdef CONFIG_NET_FLOW_LIMIT
4619 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4620 #endif
4621 
4622 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4623 {
4624 #ifdef CONFIG_NET_FLOW_LIMIT
4625 	struct sd_flow_limit *fl;
4626 	struct softnet_data *sd;
4627 	unsigned int old_flow, new_flow;
4628 
4629 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4630 		return false;
4631 
4632 	sd = this_cpu_ptr(&softnet_data);
4633 
4634 	rcu_read_lock();
4635 	fl = rcu_dereference(sd->flow_limit);
4636 	if (fl) {
4637 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4638 		old_flow = fl->history[fl->history_head];
4639 		fl->history[fl->history_head] = new_flow;
4640 
4641 		fl->history_head++;
4642 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4643 
4644 		if (likely(fl->buckets[old_flow]))
4645 			fl->buckets[old_flow]--;
4646 
4647 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4648 			fl->count++;
4649 			rcu_read_unlock();
4650 			return true;
4651 		}
4652 	}
4653 	rcu_read_unlock();
4654 #endif
4655 	return false;
4656 }
4657 
4658 /*
4659  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4660  * queue (may be a remote CPU queue).
4661  */
4662 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4663 			      unsigned int *qtail)
4664 {
4665 	enum skb_drop_reason reason;
4666 	struct softnet_data *sd;
4667 	unsigned long flags;
4668 	unsigned int qlen;
4669 
4670 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4671 	sd = &per_cpu(softnet_data, cpu);
4672 
4673 	rps_lock_irqsave(sd, &flags);
4674 	if (!netif_running(skb->dev))
4675 		goto drop;
4676 	qlen = skb_queue_len(&sd->input_pkt_queue);
4677 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4678 		if (qlen) {
4679 enqueue:
4680 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4681 			input_queue_tail_incr_save(sd, qtail);
4682 			rps_unlock_irq_restore(sd, &flags);
4683 			return NET_RX_SUCCESS;
4684 		}
4685 
4686 		/* Schedule NAPI for backlog device
4687 		 * We can use non atomic operation since we own the queue lock
4688 		 */
4689 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4690 			napi_schedule_rps(sd);
4691 		goto enqueue;
4692 	}
4693 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4694 
4695 drop:
4696 	sd->dropped++;
4697 	rps_unlock_irq_restore(sd, &flags);
4698 
4699 	dev_core_stats_rx_dropped_inc(skb->dev);
4700 	kfree_skb_reason(skb, reason);
4701 	return NET_RX_DROP;
4702 }
4703 
4704 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4705 {
4706 	struct net_device *dev = skb->dev;
4707 	struct netdev_rx_queue *rxqueue;
4708 
4709 	rxqueue = dev->_rx;
4710 
4711 	if (skb_rx_queue_recorded(skb)) {
4712 		u16 index = skb_get_rx_queue(skb);
4713 
4714 		if (unlikely(index >= dev->real_num_rx_queues)) {
4715 			WARN_ONCE(dev->real_num_rx_queues > 1,
4716 				  "%s received packet on queue %u, but number "
4717 				  "of RX queues is %u\n",
4718 				  dev->name, index, dev->real_num_rx_queues);
4719 
4720 			return rxqueue; /* Return first rxqueue */
4721 		}
4722 		rxqueue += index;
4723 	}
4724 	return rxqueue;
4725 }
4726 
4727 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4728 			     struct bpf_prog *xdp_prog)
4729 {
4730 	void *orig_data, *orig_data_end, *hard_start;
4731 	struct netdev_rx_queue *rxqueue;
4732 	bool orig_bcast, orig_host;
4733 	u32 mac_len, frame_sz;
4734 	__be16 orig_eth_type;
4735 	struct ethhdr *eth;
4736 	u32 metalen, act;
4737 	int off;
4738 
4739 	/* The XDP program wants to see the packet starting at the MAC
4740 	 * header.
4741 	 */
4742 	mac_len = skb->data - skb_mac_header(skb);
4743 	hard_start = skb->data - skb_headroom(skb);
4744 
4745 	/* SKB "head" area always have tailroom for skb_shared_info */
4746 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4747 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4748 
4749 	rxqueue = netif_get_rxqueue(skb);
4750 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4751 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4752 			 skb_headlen(skb) + mac_len, true);
4753 
4754 	orig_data_end = xdp->data_end;
4755 	orig_data = xdp->data;
4756 	eth = (struct ethhdr *)xdp->data;
4757 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4758 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4759 	orig_eth_type = eth->h_proto;
4760 
4761 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4762 
4763 	/* check if bpf_xdp_adjust_head was used */
4764 	off = xdp->data - orig_data;
4765 	if (off) {
4766 		if (off > 0)
4767 			__skb_pull(skb, off);
4768 		else if (off < 0)
4769 			__skb_push(skb, -off);
4770 
4771 		skb->mac_header += off;
4772 		skb_reset_network_header(skb);
4773 	}
4774 
4775 	/* check if bpf_xdp_adjust_tail was used */
4776 	off = xdp->data_end - orig_data_end;
4777 	if (off != 0) {
4778 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4779 		skb->len += off; /* positive on grow, negative on shrink */
4780 	}
4781 
4782 	/* check if XDP changed eth hdr such SKB needs update */
4783 	eth = (struct ethhdr *)xdp->data;
4784 	if ((orig_eth_type != eth->h_proto) ||
4785 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4786 						  skb->dev->dev_addr)) ||
4787 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4788 		__skb_push(skb, ETH_HLEN);
4789 		skb->pkt_type = PACKET_HOST;
4790 		skb->protocol = eth_type_trans(skb, skb->dev);
4791 	}
4792 
4793 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4794 	 * before calling us again on redirect path. We do not call do_redirect
4795 	 * as we leave that up to the caller.
4796 	 *
4797 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4798 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4799 	 */
4800 	switch (act) {
4801 	case XDP_REDIRECT:
4802 	case XDP_TX:
4803 		__skb_push(skb, mac_len);
4804 		break;
4805 	case XDP_PASS:
4806 		metalen = xdp->data - xdp->data_meta;
4807 		if (metalen)
4808 			skb_metadata_set(skb, metalen);
4809 		break;
4810 	}
4811 
4812 	return act;
4813 }
4814 
4815 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4816 				     struct xdp_buff *xdp,
4817 				     struct bpf_prog *xdp_prog)
4818 {
4819 	u32 act = XDP_DROP;
4820 
4821 	/* Reinjected packets coming from act_mirred or similar should
4822 	 * not get XDP generic processing.
4823 	 */
4824 	if (skb_is_redirected(skb))
4825 		return XDP_PASS;
4826 
4827 	/* XDP packets must be linear and must have sufficient headroom
4828 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4829 	 * native XDP provides, thus we need to do it here as well.
4830 	 */
4831 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4832 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4833 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4834 		int troom = skb->tail + skb->data_len - skb->end;
4835 
4836 		/* In case we have to go down the path and also linearize,
4837 		 * then lets do the pskb_expand_head() work just once here.
4838 		 */
4839 		if (pskb_expand_head(skb,
4840 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4841 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4842 			goto do_drop;
4843 		if (skb_linearize(skb))
4844 			goto do_drop;
4845 	}
4846 
4847 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4848 	switch (act) {
4849 	case XDP_REDIRECT:
4850 	case XDP_TX:
4851 	case XDP_PASS:
4852 		break;
4853 	default:
4854 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4855 		fallthrough;
4856 	case XDP_ABORTED:
4857 		trace_xdp_exception(skb->dev, xdp_prog, act);
4858 		fallthrough;
4859 	case XDP_DROP:
4860 	do_drop:
4861 		kfree_skb(skb);
4862 		break;
4863 	}
4864 
4865 	return act;
4866 }
4867 
4868 /* When doing generic XDP we have to bypass the qdisc layer and the
4869  * network taps in order to match in-driver-XDP behavior. This also means
4870  * that XDP packets are able to starve other packets going through a qdisc,
4871  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4872  * queues, so they do not have this starvation issue.
4873  */
4874 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4875 {
4876 	struct net_device *dev = skb->dev;
4877 	struct netdev_queue *txq;
4878 	bool free_skb = true;
4879 	int cpu, rc;
4880 
4881 	txq = netdev_core_pick_tx(dev, skb, NULL);
4882 	cpu = smp_processor_id();
4883 	HARD_TX_LOCK(dev, txq, cpu);
4884 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4885 		rc = netdev_start_xmit(skb, dev, txq, 0);
4886 		if (dev_xmit_complete(rc))
4887 			free_skb = false;
4888 	}
4889 	HARD_TX_UNLOCK(dev, txq);
4890 	if (free_skb) {
4891 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4892 		dev_core_stats_tx_dropped_inc(dev);
4893 		kfree_skb(skb);
4894 	}
4895 }
4896 
4897 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4898 
4899 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4900 {
4901 	if (xdp_prog) {
4902 		struct xdp_buff xdp;
4903 		u32 act;
4904 		int err;
4905 
4906 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4907 		if (act != XDP_PASS) {
4908 			switch (act) {
4909 			case XDP_REDIRECT:
4910 				err = xdp_do_generic_redirect(skb->dev, skb,
4911 							      &xdp, xdp_prog);
4912 				if (err)
4913 					goto out_redir;
4914 				break;
4915 			case XDP_TX:
4916 				generic_xdp_tx(skb, xdp_prog);
4917 				break;
4918 			}
4919 			return XDP_DROP;
4920 		}
4921 	}
4922 	return XDP_PASS;
4923 out_redir:
4924 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4925 	return XDP_DROP;
4926 }
4927 EXPORT_SYMBOL_GPL(do_xdp_generic);
4928 
4929 static int netif_rx_internal(struct sk_buff *skb)
4930 {
4931 	int ret;
4932 
4933 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
4934 
4935 	trace_netif_rx(skb);
4936 
4937 #ifdef CONFIG_RPS
4938 	if (static_branch_unlikely(&rps_needed)) {
4939 		struct rps_dev_flow voidflow, *rflow = &voidflow;
4940 		int cpu;
4941 
4942 		rcu_read_lock();
4943 
4944 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
4945 		if (cpu < 0)
4946 			cpu = smp_processor_id();
4947 
4948 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4949 
4950 		rcu_read_unlock();
4951 	} else
4952 #endif
4953 	{
4954 		unsigned int qtail;
4955 
4956 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4957 	}
4958 	return ret;
4959 }
4960 
4961 /**
4962  *	__netif_rx	-	Slightly optimized version of netif_rx
4963  *	@skb: buffer to post
4964  *
4965  *	This behaves as netif_rx except that it does not disable bottom halves.
4966  *	As a result this function may only be invoked from the interrupt context
4967  *	(either hard or soft interrupt).
4968  */
4969 int __netif_rx(struct sk_buff *skb)
4970 {
4971 	int ret;
4972 
4973 	lockdep_assert_once(hardirq_count() | softirq_count());
4974 
4975 	trace_netif_rx_entry(skb);
4976 	ret = netif_rx_internal(skb);
4977 	trace_netif_rx_exit(ret);
4978 	return ret;
4979 }
4980 EXPORT_SYMBOL(__netif_rx);
4981 
4982 /**
4983  *	netif_rx	-	post buffer to the network code
4984  *	@skb: buffer to post
4985  *
4986  *	This function receives a packet from a device driver and queues it for
4987  *	the upper (protocol) levels to process via the backlog NAPI device. It
4988  *	always succeeds. The buffer may be dropped during processing for
4989  *	congestion control or by the protocol layers.
4990  *	The network buffer is passed via the backlog NAPI device. Modern NIC
4991  *	driver should use NAPI and GRO.
4992  *	This function can used from interrupt and from process context. The
4993  *	caller from process context must not disable interrupts before invoking
4994  *	this function.
4995  *
4996  *	return values:
4997  *	NET_RX_SUCCESS	(no congestion)
4998  *	NET_RX_DROP     (packet was dropped)
4999  *
5000  */
5001 int netif_rx(struct sk_buff *skb)
5002 {
5003 	bool need_bh_off = !(hardirq_count() | softirq_count());
5004 	int ret;
5005 
5006 	if (need_bh_off)
5007 		local_bh_disable();
5008 	trace_netif_rx_entry(skb);
5009 	ret = netif_rx_internal(skb);
5010 	trace_netif_rx_exit(ret);
5011 	if (need_bh_off)
5012 		local_bh_enable();
5013 	return ret;
5014 }
5015 EXPORT_SYMBOL(netif_rx);
5016 
5017 static __latent_entropy void net_tx_action(struct softirq_action *h)
5018 {
5019 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5020 
5021 	if (sd->completion_queue) {
5022 		struct sk_buff *clist;
5023 
5024 		local_irq_disable();
5025 		clist = sd->completion_queue;
5026 		sd->completion_queue = NULL;
5027 		local_irq_enable();
5028 
5029 		while (clist) {
5030 			struct sk_buff *skb = clist;
5031 
5032 			clist = clist->next;
5033 
5034 			WARN_ON(refcount_read(&skb->users));
5035 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5036 				trace_consume_skb(skb, net_tx_action);
5037 			else
5038 				trace_kfree_skb(skb, net_tx_action,
5039 						get_kfree_skb_cb(skb)->reason);
5040 
5041 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5042 				__kfree_skb(skb);
5043 			else
5044 				__kfree_skb_defer(skb);
5045 		}
5046 	}
5047 
5048 	if (sd->output_queue) {
5049 		struct Qdisc *head;
5050 
5051 		local_irq_disable();
5052 		head = sd->output_queue;
5053 		sd->output_queue = NULL;
5054 		sd->output_queue_tailp = &sd->output_queue;
5055 		local_irq_enable();
5056 
5057 		rcu_read_lock();
5058 
5059 		while (head) {
5060 			struct Qdisc *q = head;
5061 			spinlock_t *root_lock = NULL;
5062 
5063 			head = head->next_sched;
5064 
5065 			/* We need to make sure head->next_sched is read
5066 			 * before clearing __QDISC_STATE_SCHED
5067 			 */
5068 			smp_mb__before_atomic();
5069 
5070 			if (!(q->flags & TCQ_F_NOLOCK)) {
5071 				root_lock = qdisc_lock(q);
5072 				spin_lock(root_lock);
5073 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5074 						     &q->state))) {
5075 				/* There is a synchronize_net() between
5076 				 * STATE_DEACTIVATED flag being set and
5077 				 * qdisc_reset()/some_qdisc_is_busy() in
5078 				 * dev_deactivate(), so we can safely bail out
5079 				 * early here to avoid data race between
5080 				 * qdisc_deactivate() and some_qdisc_is_busy()
5081 				 * for lockless qdisc.
5082 				 */
5083 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5084 				continue;
5085 			}
5086 
5087 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5088 			qdisc_run(q);
5089 			if (root_lock)
5090 				spin_unlock(root_lock);
5091 		}
5092 
5093 		rcu_read_unlock();
5094 	}
5095 
5096 	xfrm_dev_backlog(sd);
5097 }
5098 
5099 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5100 /* This hook is defined here for ATM LANE */
5101 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5102 			     unsigned char *addr) __read_mostly;
5103 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5104 #endif
5105 
5106 static inline struct sk_buff *
5107 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5108 		   struct net_device *orig_dev, bool *another)
5109 {
5110 #ifdef CONFIG_NET_CLS_ACT
5111 	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5112 	struct tcf_result cl_res;
5113 
5114 	/* If there's at least one ingress present somewhere (so
5115 	 * we get here via enabled static key), remaining devices
5116 	 * that are not configured with an ingress qdisc will bail
5117 	 * out here.
5118 	 */
5119 	if (!miniq)
5120 		return skb;
5121 
5122 	if (*pt_prev) {
5123 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
5124 		*pt_prev = NULL;
5125 	}
5126 
5127 	qdisc_skb_cb(skb)->pkt_len = skb->len;
5128 	tc_skb_cb(skb)->mru = 0;
5129 	tc_skb_cb(skb)->post_ct = false;
5130 	skb->tc_at_ingress = 1;
5131 	mini_qdisc_bstats_cpu_update(miniq, skb);
5132 
5133 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5134 	case TC_ACT_OK:
5135 	case TC_ACT_RECLASSIFY:
5136 		skb->tc_index = TC_H_MIN(cl_res.classid);
5137 		break;
5138 	case TC_ACT_SHOT:
5139 		mini_qdisc_qstats_cpu_drop(miniq);
5140 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5141 		*ret = NET_RX_DROP;
5142 		return NULL;
5143 	case TC_ACT_STOLEN:
5144 	case TC_ACT_QUEUED:
5145 	case TC_ACT_TRAP:
5146 		consume_skb(skb);
5147 		*ret = NET_RX_SUCCESS;
5148 		return NULL;
5149 	case TC_ACT_REDIRECT:
5150 		/* skb_mac_header check was done by cls/act_bpf, so
5151 		 * we can safely push the L2 header back before
5152 		 * redirecting to another netdev
5153 		 */
5154 		__skb_push(skb, skb->mac_len);
5155 		if (skb_do_redirect(skb) == -EAGAIN) {
5156 			__skb_pull(skb, skb->mac_len);
5157 			*another = true;
5158 			break;
5159 		}
5160 		*ret = NET_RX_SUCCESS;
5161 		return NULL;
5162 	case TC_ACT_CONSUMED:
5163 		*ret = NET_RX_SUCCESS;
5164 		return NULL;
5165 	default:
5166 		break;
5167 	}
5168 #endif /* CONFIG_NET_CLS_ACT */
5169 	return skb;
5170 }
5171 
5172 /**
5173  *	netdev_is_rx_handler_busy - check if receive handler is registered
5174  *	@dev: device to check
5175  *
5176  *	Check if a receive handler is already registered for a given device.
5177  *	Return true if there one.
5178  *
5179  *	The caller must hold the rtnl_mutex.
5180  */
5181 bool netdev_is_rx_handler_busy(struct net_device *dev)
5182 {
5183 	ASSERT_RTNL();
5184 	return dev && rtnl_dereference(dev->rx_handler);
5185 }
5186 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5187 
5188 /**
5189  *	netdev_rx_handler_register - register receive handler
5190  *	@dev: device to register a handler for
5191  *	@rx_handler: receive handler to register
5192  *	@rx_handler_data: data pointer that is used by rx handler
5193  *
5194  *	Register a receive handler for a device. This handler will then be
5195  *	called from __netif_receive_skb. A negative errno code is returned
5196  *	on a failure.
5197  *
5198  *	The caller must hold the rtnl_mutex.
5199  *
5200  *	For a general description of rx_handler, see enum rx_handler_result.
5201  */
5202 int netdev_rx_handler_register(struct net_device *dev,
5203 			       rx_handler_func_t *rx_handler,
5204 			       void *rx_handler_data)
5205 {
5206 	if (netdev_is_rx_handler_busy(dev))
5207 		return -EBUSY;
5208 
5209 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5210 		return -EINVAL;
5211 
5212 	/* Note: rx_handler_data must be set before rx_handler */
5213 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5214 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5215 
5216 	return 0;
5217 }
5218 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5219 
5220 /**
5221  *	netdev_rx_handler_unregister - unregister receive handler
5222  *	@dev: device to unregister a handler from
5223  *
5224  *	Unregister a receive handler from a device.
5225  *
5226  *	The caller must hold the rtnl_mutex.
5227  */
5228 void netdev_rx_handler_unregister(struct net_device *dev)
5229 {
5230 
5231 	ASSERT_RTNL();
5232 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5233 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5234 	 * section has a guarantee to see a non NULL rx_handler_data
5235 	 * as well.
5236 	 */
5237 	synchronize_net();
5238 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5239 }
5240 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5241 
5242 /*
5243  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5244  * the special handling of PFMEMALLOC skbs.
5245  */
5246 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5247 {
5248 	switch (skb->protocol) {
5249 	case htons(ETH_P_ARP):
5250 	case htons(ETH_P_IP):
5251 	case htons(ETH_P_IPV6):
5252 	case htons(ETH_P_8021Q):
5253 	case htons(ETH_P_8021AD):
5254 		return true;
5255 	default:
5256 		return false;
5257 	}
5258 }
5259 
5260 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5261 			     int *ret, struct net_device *orig_dev)
5262 {
5263 	if (nf_hook_ingress_active(skb)) {
5264 		int ingress_retval;
5265 
5266 		if (*pt_prev) {
5267 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5268 			*pt_prev = NULL;
5269 		}
5270 
5271 		rcu_read_lock();
5272 		ingress_retval = nf_hook_ingress(skb);
5273 		rcu_read_unlock();
5274 		return ingress_retval;
5275 	}
5276 	return 0;
5277 }
5278 
5279 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5280 				    struct packet_type **ppt_prev)
5281 {
5282 	struct packet_type *ptype, *pt_prev;
5283 	rx_handler_func_t *rx_handler;
5284 	struct sk_buff *skb = *pskb;
5285 	struct net_device *orig_dev;
5286 	bool deliver_exact = false;
5287 	int ret = NET_RX_DROP;
5288 	__be16 type;
5289 
5290 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5291 
5292 	trace_netif_receive_skb(skb);
5293 
5294 	orig_dev = skb->dev;
5295 
5296 	skb_reset_network_header(skb);
5297 	if (!skb_transport_header_was_set(skb))
5298 		skb_reset_transport_header(skb);
5299 	skb_reset_mac_len(skb);
5300 
5301 	pt_prev = NULL;
5302 
5303 another_round:
5304 	skb->skb_iif = skb->dev->ifindex;
5305 
5306 	__this_cpu_inc(softnet_data.processed);
5307 
5308 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5309 		int ret2;
5310 
5311 		migrate_disable();
5312 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5313 		migrate_enable();
5314 
5315 		if (ret2 != XDP_PASS) {
5316 			ret = NET_RX_DROP;
5317 			goto out;
5318 		}
5319 	}
5320 
5321 	if (eth_type_vlan(skb->protocol)) {
5322 		skb = skb_vlan_untag(skb);
5323 		if (unlikely(!skb))
5324 			goto out;
5325 	}
5326 
5327 	if (skb_skip_tc_classify(skb))
5328 		goto skip_classify;
5329 
5330 	if (pfmemalloc)
5331 		goto skip_taps;
5332 
5333 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5334 		if (pt_prev)
5335 			ret = deliver_skb(skb, pt_prev, orig_dev);
5336 		pt_prev = ptype;
5337 	}
5338 
5339 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5340 		if (pt_prev)
5341 			ret = deliver_skb(skb, pt_prev, orig_dev);
5342 		pt_prev = ptype;
5343 	}
5344 
5345 skip_taps:
5346 #ifdef CONFIG_NET_INGRESS
5347 	if (static_branch_unlikely(&ingress_needed_key)) {
5348 		bool another = false;
5349 
5350 		nf_skip_egress(skb, true);
5351 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5352 					 &another);
5353 		if (another)
5354 			goto another_round;
5355 		if (!skb)
5356 			goto out;
5357 
5358 		nf_skip_egress(skb, false);
5359 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5360 			goto out;
5361 	}
5362 #endif
5363 	skb_reset_redirect(skb);
5364 skip_classify:
5365 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5366 		goto drop;
5367 
5368 	if (skb_vlan_tag_present(skb)) {
5369 		if (pt_prev) {
5370 			ret = deliver_skb(skb, pt_prev, orig_dev);
5371 			pt_prev = NULL;
5372 		}
5373 		if (vlan_do_receive(&skb))
5374 			goto another_round;
5375 		else if (unlikely(!skb))
5376 			goto out;
5377 	}
5378 
5379 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5380 	if (rx_handler) {
5381 		if (pt_prev) {
5382 			ret = deliver_skb(skb, pt_prev, orig_dev);
5383 			pt_prev = NULL;
5384 		}
5385 		switch (rx_handler(&skb)) {
5386 		case RX_HANDLER_CONSUMED:
5387 			ret = NET_RX_SUCCESS;
5388 			goto out;
5389 		case RX_HANDLER_ANOTHER:
5390 			goto another_round;
5391 		case RX_HANDLER_EXACT:
5392 			deliver_exact = true;
5393 			break;
5394 		case RX_HANDLER_PASS:
5395 			break;
5396 		default:
5397 			BUG();
5398 		}
5399 	}
5400 
5401 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5402 check_vlan_id:
5403 		if (skb_vlan_tag_get_id(skb)) {
5404 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5405 			 * find vlan device.
5406 			 */
5407 			skb->pkt_type = PACKET_OTHERHOST;
5408 		} else if (eth_type_vlan(skb->protocol)) {
5409 			/* Outer header is 802.1P with vlan 0, inner header is
5410 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5411 			 * not find vlan dev for vlan id 0.
5412 			 */
5413 			__vlan_hwaccel_clear_tag(skb);
5414 			skb = skb_vlan_untag(skb);
5415 			if (unlikely(!skb))
5416 				goto out;
5417 			if (vlan_do_receive(&skb))
5418 				/* After stripping off 802.1P header with vlan 0
5419 				 * vlan dev is found for inner header.
5420 				 */
5421 				goto another_round;
5422 			else if (unlikely(!skb))
5423 				goto out;
5424 			else
5425 				/* We have stripped outer 802.1P vlan 0 header.
5426 				 * But could not find vlan dev.
5427 				 * check again for vlan id to set OTHERHOST.
5428 				 */
5429 				goto check_vlan_id;
5430 		}
5431 		/* Note: we might in the future use prio bits
5432 		 * and set skb->priority like in vlan_do_receive()
5433 		 * For the time being, just ignore Priority Code Point
5434 		 */
5435 		__vlan_hwaccel_clear_tag(skb);
5436 	}
5437 
5438 	type = skb->protocol;
5439 
5440 	/* deliver only exact match when indicated */
5441 	if (likely(!deliver_exact)) {
5442 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5443 				       &ptype_base[ntohs(type) &
5444 						   PTYPE_HASH_MASK]);
5445 	}
5446 
5447 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5448 			       &orig_dev->ptype_specific);
5449 
5450 	if (unlikely(skb->dev != orig_dev)) {
5451 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5452 				       &skb->dev->ptype_specific);
5453 	}
5454 
5455 	if (pt_prev) {
5456 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5457 			goto drop;
5458 		*ppt_prev = pt_prev;
5459 	} else {
5460 drop:
5461 		if (!deliver_exact)
5462 			dev_core_stats_rx_dropped_inc(skb->dev);
5463 		else
5464 			dev_core_stats_rx_nohandler_inc(skb->dev);
5465 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5466 		/* Jamal, now you will not able to escape explaining
5467 		 * me how you were going to use this. :-)
5468 		 */
5469 		ret = NET_RX_DROP;
5470 	}
5471 
5472 out:
5473 	/* The invariant here is that if *ppt_prev is not NULL
5474 	 * then skb should also be non-NULL.
5475 	 *
5476 	 * Apparently *ppt_prev assignment above holds this invariant due to
5477 	 * skb dereferencing near it.
5478 	 */
5479 	*pskb = skb;
5480 	return ret;
5481 }
5482 
5483 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5484 {
5485 	struct net_device *orig_dev = skb->dev;
5486 	struct packet_type *pt_prev = NULL;
5487 	int ret;
5488 
5489 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5490 	if (pt_prev)
5491 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5492 					 skb->dev, pt_prev, orig_dev);
5493 	return ret;
5494 }
5495 
5496 /**
5497  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5498  *	@skb: buffer to process
5499  *
5500  *	More direct receive version of netif_receive_skb().  It should
5501  *	only be used by callers that have a need to skip RPS and Generic XDP.
5502  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5503  *
5504  *	This function may only be called from softirq context and interrupts
5505  *	should be enabled.
5506  *
5507  *	Return values (usually ignored):
5508  *	NET_RX_SUCCESS: no congestion
5509  *	NET_RX_DROP: packet was dropped
5510  */
5511 int netif_receive_skb_core(struct sk_buff *skb)
5512 {
5513 	int ret;
5514 
5515 	rcu_read_lock();
5516 	ret = __netif_receive_skb_one_core(skb, false);
5517 	rcu_read_unlock();
5518 
5519 	return ret;
5520 }
5521 EXPORT_SYMBOL(netif_receive_skb_core);
5522 
5523 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5524 						  struct packet_type *pt_prev,
5525 						  struct net_device *orig_dev)
5526 {
5527 	struct sk_buff *skb, *next;
5528 
5529 	if (!pt_prev)
5530 		return;
5531 	if (list_empty(head))
5532 		return;
5533 	if (pt_prev->list_func != NULL)
5534 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5535 				   ip_list_rcv, head, pt_prev, orig_dev);
5536 	else
5537 		list_for_each_entry_safe(skb, next, head, list) {
5538 			skb_list_del_init(skb);
5539 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5540 		}
5541 }
5542 
5543 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5544 {
5545 	/* Fast-path assumptions:
5546 	 * - There is no RX handler.
5547 	 * - Only one packet_type matches.
5548 	 * If either of these fails, we will end up doing some per-packet
5549 	 * processing in-line, then handling the 'last ptype' for the whole
5550 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5551 	 * because the 'last ptype' must be constant across the sublist, and all
5552 	 * other ptypes are handled per-packet.
5553 	 */
5554 	/* Current (common) ptype of sublist */
5555 	struct packet_type *pt_curr = NULL;
5556 	/* Current (common) orig_dev of sublist */
5557 	struct net_device *od_curr = NULL;
5558 	struct list_head sublist;
5559 	struct sk_buff *skb, *next;
5560 
5561 	INIT_LIST_HEAD(&sublist);
5562 	list_for_each_entry_safe(skb, next, head, list) {
5563 		struct net_device *orig_dev = skb->dev;
5564 		struct packet_type *pt_prev = NULL;
5565 
5566 		skb_list_del_init(skb);
5567 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5568 		if (!pt_prev)
5569 			continue;
5570 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5571 			/* dispatch old sublist */
5572 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5573 			/* start new sublist */
5574 			INIT_LIST_HEAD(&sublist);
5575 			pt_curr = pt_prev;
5576 			od_curr = orig_dev;
5577 		}
5578 		list_add_tail(&skb->list, &sublist);
5579 	}
5580 
5581 	/* dispatch final sublist */
5582 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5583 }
5584 
5585 static int __netif_receive_skb(struct sk_buff *skb)
5586 {
5587 	int ret;
5588 
5589 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5590 		unsigned int noreclaim_flag;
5591 
5592 		/*
5593 		 * PFMEMALLOC skbs are special, they should
5594 		 * - be delivered to SOCK_MEMALLOC sockets only
5595 		 * - stay away from userspace
5596 		 * - have bounded memory usage
5597 		 *
5598 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5599 		 * context down to all allocation sites.
5600 		 */
5601 		noreclaim_flag = memalloc_noreclaim_save();
5602 		ret = __netif_receive_skb_one_core(skb, true);
5603 		memalloc_noreclaim_restore(noreclaim_flag);
5604 	} else
5605 		ret = __netif_receive_skb_one_core(skb, false);
5606 
5607 	return ret;
5608 }
5609 
5610 static void __netif_receive_skb_list(struct list_head *head)
5611 {
5612 	unsigned long noreclaim_flag = 0;
5613 	struct sk_buff *skb, *next;
5614 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5615 
5616 	list_for_each_entry_safe(skb, next, head, list) {
5617 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5618 			struct list_head sublist;
5619 
5620 			/* Handle the previous sublist */
5621 			list_cut_before(&sublist, head, &skb->list);
5622 			if (!list_empty(&sublist))
5623 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5624 			pfmemalloc = !pfmemalloc;
5625 			/* See comments in __netif_receive_skb */
5626 			if (pfmemalloc)
5627 				noreclaim_flag = memalloc_noreclaim_save();
5628 			else
5629 				memalloc_noreclaim_restore(noreclaim_flag);
5630 		}
5631 	}
5632 	/* Handle the remaining sublist */
5633 	if (!list_empty(head))
5634 		__netif_receive_skb_list_core(head, pfmemalloc);
5635 	/* Restore pflags */
5636 	if (pfmemalloc)
5637 		memalloc_noreclaim_restore(noreclaim_flag);
5638 }
5639 
5640 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5641 {
5642 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5643 	struct bpf_prog *new = xdp->prog;
5644 	int ret = 0;
5645 
5646 	switch (xdp->command) {
5647 	case XDP_SETUP_PROG:
5648 		rcu_assign_pointer(dev->xdp_prog, new);
5649 		if (old)
5650 			bpf_prog_put(old);
5651 
5652 		if (old && !new) {
5653 			static_branch_dec(&generic_xdp_needed_key);
5654 		} else if (new && !old) {
5655 			static_branch_inc(&generic_xdp_needed_key);
5656 			dev_disable_lro(dev);
5657 			dev_disable_gro_hw(dev);
5658 		}
5659 		break;
5660 
5661 	default:
5662 		ret = -EINVAL;
5663 		break;
5664 	}
5665 
5666 	return ret;
5667 }
5668 
5669 static int netif_receive_skb_internal(struct sk_buff *skb)
5670 {
5671 	int ret;
5672 
5673 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5674 
5675 	if (skb_defer_rx_timestamp(skb))
5676 		return NET_RX_SUCCESS;
5677 
5678 	rcu_read_lock();
5679 #ifdef CONFIG_RPS
5680 	if (static_branch_unlikely(&rps_needed)) {
5681 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5682 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5683 
5684 		if (cpu >= 0) {
5685 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5686 			rcu_read_unlock();
5687 			return ret;
5688 		}
5689 	}
5690 #endif
5691 	ret = __netif_receive_skb(skb);
5692 	rcu_read_unlock();
5693 	return ret;
5694 }
5695 
5696 void netif_receive_skb_list_internal(struct list_head *head)
5697 {
5698 	struct sk_buff *skb, *next;
5699 	struct list_head sublist;
5700 
5701 	INIT_LIST_HEAD(&sublist);
5702 	list_for_each_entry_safe(skb, next, head, list) {
5703 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5704 		skb_list_del_init(skb);
5705 		if (!skb_defer_rx_timestamp(skb))
5706 			list_add_tail(&skb->list, &sublist);
5707 	}
5708 	list_splice_init(&sublist, head);
5709 
5710 	rcu_read_lock();
5711 #ifdef CONFIG_RPS
5712 	if (static_branch_unlikely(&rps_needed)) {
5713 		list_for_each_entry_safe(skb, next, head, list) {
5714 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5715 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5716 
5717 			if (cpu >= 0) {
5718 				/* Will be handled, remove from list */
5719 				skb_list_del_init(skb);
5720 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5721 			}
5722 		}
5723 	}
5724 #endif
5725 	__netif_receive_skb_list(head);
5726 	rcu_read_unlock();
5727 }
5728 
5729 /**
5730  *	netif_receive_skb - process receive buffer from network
5731  *	@skb: buffer to process
5732  *
5733  *	netif_receive_skb() is the main receive data processing function.
5734  *	It always succeeds. The buffer may be dropped during processing
5735  *	for congestion control or by the protocol layers.
5736  *
5737  *	This function may only be called from softirq context and interrupts
5738  *	should be enabled.
5739  *
5740  *	Return values (usually ignored):
5741  *	NET_RX_SUCCESS: no congestion
5742  *	NET_RX_DROP: packet was dropped
5743  */
5744 int netif_receive_skb(struct sk_buff *skb)
5745 {
5746 	int ret;
5747 
5748 	trace_netif_receive_skb_entry(skb);
5749 
5750 	ret = netif_receive_skb_internal(skb);
5751 	trace_netif_receive_skb_exit(ret);
5752 
5753 	return ret;
5754 }
5755 EXPORT_SYMBOL(netif_receive_skb);
5756 
5757 /**
5758  *	netif_receive_skb_list - process many receive buffers from network
5759  *	@head: list of skbs to process.
5760  *
5761  *	Since return value of netif_receive_skb() is normally ignored, and
5762  *	wouldn't be meaningful for a list, this function returns void.
5763  *
5764  *	This function may only be called from softirq context and interrupts
5765  *	should be enabled.
5766  */
5767 void netif_receive_skb_list(struct list_head *head)
5768 {
5769 	struct sk_buff *skb;
5770 
5771 	if (list_empty(head))
5772 		return;
5773 	if (trace_netif_receive_skb_list_entry_enabled()) {
5774 		list_for_each_entry(skb, head, list)
5775 			trace_netif_receive_skb_list_entry(skb);
5776 	}
5777 	netif_receive_skb_list_internal(head);
5778 	trace_netif_receive_skb_list_exit(0);
5779 }
5780 EXPORT_SYMBOL(netif_receive_skb_list);
5781 
5782 static DEFINE_PER_CPU(struct work_struct, flush_works);
5783 
5784 /* Network device is going away, flush any packets still pending */
5785 static void flush_backlog(struct work_struct *work)
5786 {
5787 	struct sk_buff *skb, *tmp;
5788 	struct softnet_data *sd;
5789 
5790 	local_bh_disable();
5791 	sd = this_cpu_ptr(&softnet_data);
5792 
5793 	rps_lock_irq_disable(sd);
5794 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5795 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5796 			__skb_unlink(skb, &sd->input_pkt_queue);
5797 			dev_kfree_skb_irq(skb);
5798 			input_queue_head_incr(sd);
5799 		}
5800 	}
5801 	rps_unlock_irq_enable(sd);
5802 
5803 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5804 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5805 			__skb_unlink(skb, &sd->process_queue);
5806 			kfree_skb(skb);
5807 			input_queue_head_incr(sd);
5808 		}
5809 	}
5810 	local_bh_enable();
5811 }
5812 
5813 static bool flush_required(int cpu)
5814 {
5815 #if IS_ENABLED(CONFIG_RPS)
5816 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5817 	bool do_flush;
5818 
5819 	rps_lock_irq_disable(sd);
5820 
5821 	/* as insertion into process_queue happens with the rps lock held,
5822 	 * process_queue access may race only with dequeue
5823 	 */
5824 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5825 		   !skb_queue_empty_lockless(&sd->process_queue);
5826 	rps_unlock_irq_enable(sd);
5827 
5828 	return do_flush;
5829 #endif
5830 	/* without RPS we can't safely check input_pkt_queue: during a
5831 	 * concurrent remote skb_queue_splice() we can detect as empty both
5832 	 * input_pkt_queue and process_queue even if the latter could end-up
5833 	 * containing a lot of packets.
5834 	 */
5835 	return true;
5836 }
5837 
5838 static void flush_all_backlogs(void)
5839 {
5840 	static cpumask_t flush_cpus;
5841 	unsigned int cpu;
5842 
5843 	/* since we are under rtnl lock protection we can use static data
5844 	 * for the cpumask and avoid allocating on stack the possibly
5845 	 * large mask
5846 	 */
5847 	ASSERT_RTNL();
5848 
5849 	cpus_read_lock();
5850 
5851 	cpumask_clear(&flush_cpus);
5852 	for_each_online_cpu(cpu) {
5853 		if (flush_required(cpu)) {
5854 			queue_work_on(cpu, system_highpri_wq,
5855 				      per_cpu_ptr(&flush_works, cpu));
5856 			cpumask_set_cpu(cpu, &flush_cpus);
5857 		}
5858 	}
5859 
5860 	/* we can have in flight packet[s] on the cpus we are not flushing,
5861 	 * synchronize_net() in unregister_netdevice_many() will take care of
5862 	 * them
5863 	 */
5864 	for_each_cpu(cpu, &flush_cpus)
5865 		flush_work(per_cpu_ptr(&flush_works, cpu));
5866 
5867 	cpus_read_unlock();
5868 }
5869 
5870 static void net_rps_send_ipi(struct softnet_data *remsd)
5871 {
5872 #ifdef CONFIG_RPS
5873 	while (remsd) {
5874 		struct softnet_data *next = remsd->rps_ipi_next;
5875 
5876 		if (cpu_online(remsd->cpu))
5877 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5878 		remsd = next;
5879 	}
5880 #endif
5881 }
5882 
5883 /*
5884  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5885  * Note: called with local irq disabled, but exits with local irq enabled.
5886  */
5887 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5888 {
5889 #ifdef CONFIG_RPS
5890 	struct softnet_data *remsd = sd->rps_ipi_list;
5891 
5892 	if (remsd) {
5893 		sd->rps_ipi_list = NULL;
5894 
5895 		local_irq_enable();
5896 
5897 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5898 		net_rps_send_ipi(remsd);
5899 	} else
5900 #endif
5901 		local_irq_enable();
5902 }
5903 
5904 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5905 {
5906 #ifdef CONFIG_RPS
5907 	return sd->rps_ipi_list != NULL;
5908 #else
5909 	return false;
5910 #endif
5911 }
5912 
5913 static int process_backlog(struct napi_struct *napi, int quota)
5914 {
5915 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5916 	bool again = true;
5917 	int work = 0;
5918 
5919 	/* Check if we have pending ipi, its better to send them now,
5920 	 * not waiting net_rx_action() end.
5921 	 */
5922 	if (sd_has_rps_ipi_waiting(sd)) {
5923 		local_irq_disable();
5924 		net_rps_action_and_irq_enable(sd);
5925 	}
5926 
5927 	napi->weight = READ_ONCE(dev_rx_weight);
5928 	while (again) {
5929 		struct sk_buff *skb;
5930 
5931 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5932 			rcu_read_lock();
5933 			__netif_receive_skb(skb);
5934 			rcu_read_unlock();
5935 			input_queue_head_incr(sd);
5936 			if (++work >= quota)
5937 				return work;
5938 
5939 		}
5940 
5941 		rps_lock_irq_disable(sd);
5942 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5943 			/*
5944 			 * Inline a custom version of __napi_complete().
5945 			 * only current cpu owns and manipulates this napi,
5946 			 * and NAPI_STATE_SCHED is the only possible flag set
5947 			 * on backlog.
5948 			 * We can use a plain write instead of clear_bit(),
5949 			 * and we dont need an smp_mb() memory barrier.
5950 			 */
5951 			napi->state = 0;
5952 			again = false;
5953 		} else {
5954 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5955 						   &sd->process_queue);
5956 		}
5957 		rps_unlock_irq_enable(sd);
5958 	}
5959 
5960 	return work;
5961 }
5962 
5963 /**
5964  * __napi_schedule - schedule for receive
5965  * @n: entry to schedule
5966  *
5967  * The entry's receive function will be scheduled to run.
5968  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5969  */
5970 void __napi_schedule(struct napi_struct *n)
5971 {
5972 	unsigned long flags;
5973 
5974 	local_irq_save(flags);
5975 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
5976 	local_irq_restore(flags);
5977 }
5978 EXPORT_SYMBOL(__napi_schedule);
5979 
5980 /**
5981  *	napi_schedule_prep - check if napi can be scheduled
5982  *	@n: napi context
5983  *
5984  * Test if NAPI routine is already running, and if not mark
5985  * it as running.  This is used as a condition variable to
5986  * insure only one NAPI poll instance runs.  We also make
5987  * sure there is no pending NAPI disable.
5988  */
5989 bool napi_schedule_prep(struct napi_struct *n)
5990 {
5991 	unsigned long new, val = READ_ONCE(n->state);
5992 
5993 	do {
5994 		if (unlikely(val & NAPIF_STATE_DISABLE))
5995 			return false;
5996 		new = val | NAPIF_STATE_SCHED;
5997 
5998 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
5999 		 * This was suggested by Alexander Duyck, as compiler
6000 		 * emits better code than :
6001 		 * if (val & NAPIF_STATE_SCHED)
6002 		 *     new |= NAPIF_STATE_MISSED;
6003 		 */
6004 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6005 						   NAPIF_STATE_MISSED;
6006 	} while (!try_cmpxchg(&n->state, &val, new));
6007 
6008 	return !(val & NAPIF_STATE_SCHED);
6009 }
6010 EXPORT_SYMBOL(napi_schedule_prep);
6011 
6012 /**
6013  * __napi_schedule_irqoff - schedule for receive
6014  * @n: entry to schedule
6015  *
6016  * Variant of __napi_schedule() assuming hard irqs are masked.
6017  *
6018  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6019  * because the interrupt disabled assumption might not be true
6020  * due to force-threaded interrupts and spinlock substitution.
6021  */
6022 void __napi_schedule_irqoff(struct napi_struct *n)
6023 {
6024 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6025 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6026 	else
6027 		__napi_schedule(n);
6028 }
6029 EXPORT_SYMBOL(__napi_schedule_irqoff);
6030 
6031 bool napi_complete_done(struct napi_struct *n, int work_done)
6032 {
6033 	unsigned long flags, val, new, timeout = 0;
6034 	bool ret = true;
6035 
6036 	/*
6037 	 * 1) Don't let napi dequeue from the cpu poll list
6038 	 *    just in case its running on a different cpu.
6039 	 * 2) If we are busy polling, do nothing here, we have
6040 	 *    the guarantee we will be called later.
6041 	 */
6042 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6043 				 NAPIF_STATE_IN_BUSY_POLL)))
6044 		return false;
6045 
6046 	if (work_done) {
6047 		if (n->gro_bitmask)
6048 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6049 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6050 	}
6051 	if (n->defer_hard_irqs_count > 0) {
6052 		n->defer_hard_irqs_count--;
6053 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6054 		if (timeout)
6055 			ret = false;
6056 	}
6057 	if (n->gro_bitmask) {
6058 		/* When the NAPI instance uses a timeout and keeps postponing
6059 		 * it, we need to bound somehow the time packets are kept in
6060 		 * the GRO layer
6061 		 */
6062 		napi_gro_flush(n, !!timeout);
6063 	}
6064 
6065 	gro_normal_list(n);
6066 
6067 	if (unlikely(!list_empty(&n->poll_list))) {
6068 		/* If n->poll_list is not empty, we need to mask irqs */
6069 		local_irq_save(flags);
6070 		list_del_init(&n->poll_list);
6071 		local_irq_restore(flags);
6072 	}
6073 	WRITE_ONCE(n->list_owner, -1);
6074 
6075 	val = READ_ONCE(n->state);
6076 	do {
6077 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6078 
6079 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6080 			      NAPIF_STATE_SCHED_THREADED |
6081 			      NAPIF_STATE_PREFER_BUSY_POLL);
6082 
6083 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6084 		 * because we will call napi->poll() one more time.
6085 		 * This C code was suggested by Alexander Duyck to help gcc.
6086 		 */
6087 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6088 						    NAPIF_STATE_SCHED;
6089 	} while (!try_cmpxchg(&n->state, &val, new));
6090 
6091 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6092 		__napi_schedule(n);
6093 		return false;
6094 	}
6095 
6096 	if (timeout)
6097 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6098 			      HRTIMER_MODE_REL_PINNED);
6099 	return ret;
6100 }
6101 EXPORT_SYMBOL(napi_complete_done);
6102 
6103 /* must be called under rcu_read_lock(), as we dont take a reference */
6104 static struct napi_struct *napi_by_id(unsigned int napi_id)
6105 {
6106 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6107 	struct napi_struct *napi;
6108 
6109 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6110 		if (napi->napi_id == napi_id)
6111 			return napi;
6112 
6113 	return NULL;
6114 }
6115 
6116 #if defined(CONFIG_NET_RX_BUSY_POLL)
6117 
6118 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6119 {
6120 	if (!skip_schedule) {
6121 		gro_normal_list(napi);
6122 		__napi_schedule(napi);
6123 		return;
6124 	}
6125 
6126 	if (napi->gro_bitmask) {
6127 		/* flush too old packets
6128 		 * If HZ < 1000, flush all packets.
6129 		 */
6130 		napi_gro_flush(napi, HZ >= 1000);
6131 	}
6132 
6133 	gro_normal_list(napi);
6134 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6135 }
6136 
6137 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6138 			   u16 budget)
6139 {
6140 	bool skip_schedule = false;
6141 	unsigned long timeout;
6142 	int rc;
6143 
6144 	/* Busy polling means there is a high chance device driver hard irq
6145 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6146 	 * set in napi_schedule_prep().
6147 	 * Since we are about to call napi->poll() once more, we can safely
6148 	 * clear NAPI_STATE_MISSED.
6149 	 *
6150 	 * Note: x86 could use a single "lock and ..." instruction
6151 	 * to perform these two clear_bit()
6152 	 */
6153 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6154 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6155 
6156 	local_bh_disable();
6157 
6158 	if (prefer_busy_poll) {
6159 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6160 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6161 		if (napi->defer_hard_irqs_count && timeout) {
6162 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6163 			skip_schedule = true;
6164 		}
6165 	}
6166 
6167 	/* All we really want here is to re-enable device interrupts.
6168 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6169 	 */
6170 	rc = napi->poll(napi, budget);
6171 	/* We can't gro_normal_list() here, because napi->poll() might have
6172 	 * rearmed the napi (napi_complete_done()) in which case it could
6173 	 * already be running on another CPU.
6174 	 */
6175 	trace_napi_poll(napi, rc, budget);
6176 	netpoll_poll_unlock(have_poll_lock);
6177 	if (rc == budget)
6178 		__busy_poll_stop(napi, skip_schedule);
6179 	local_bh_enable();
6180 }
6181 
6182 void napi_busy_loop(unsigned int napi_id,
6183 		    bool (*loop_end)(void *, unsigned long),
6184 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6185 {
6186 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6187 	int (*napi_poll)(struct napi_struct *napi, int budget);
6188 	void *have_poll_lock = NULL;
6189 	struct napi_struct *napi;
6190 
6191 restart:
6192 	napi_poll = NULL;
6193 
6194 	rcu_read_lock();
6195 
6196 	napi = napi_by_id(napi_id);
6197 	if (!napi)
6198 		goto out;
6199 
6200 	preempt_disable();
6201 	for (;;) {
6202 		int work = 0;
6203 
6204 		local_bh_disable();
6205 		if (!napi_poll) {
6206 			unsigned long val = READ_ONCE(napi->state);
6207 
6208 			/* If multiple threads are competing for this napi,
6209 			 * we avoid dirtying napi->state as much as we can.
6210 			 */
6211 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6212 				   NAPIF_STATE_IN_BUSY_POLL)) {
6213 				if (prefer_busy_poll)
6214 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6215 				goto count;
6216 			}
6217 			if (cmpxchg(&napi->state, val,
6218 				    val | NAPIF_STATE_IN_BUSY_POLL |
6219 					  NAPIF_STATE_SCHED) != val) {
6220 				if (prefer_busy_poll)
6221 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6222 				goto count;
6223 			}
6224 			have_poll_lock = netpoll_poll_lock(napi);
6225 			napi_poll = napi->poll;
6226 		}
6227 		work = napi_poll(napi, budget);
6228 		trace_napi_poll(napi, work, budget);
6229 		gro_normal_list(napi);
6230 count:
6231 		if (work > 0)
6232 			__NET_ADD_STATS(dev_net(napi->dev),
6233 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6234 		local_bh_enable();
6235 
6236 		if (!loop_end || loop_end(loop_end_arg, start_time))
6237 			break;
6238 
6239 		if (unlikely(need_resched())) {
6240 			if (napi_poll)
6241 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6242 			preempt_enable();
6243 			rcu_read_unlock();
6244 			cond_resched();
6245 			if (loop_end(loop_end_arg, start_time))
6246 				return;
6247 			goto restart;
6248 		}
6249 		cpu_relax();
6250 	}
6251 	if (napi_poll)
6252 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6253 	preempt_enable();
6254 out:
6255 	rcu_read_unlock();
6256 }
6257 EXPORT_SYMBOL(napi_busy_loop);
6258 
6259 #endif /* CONFIG_NET_RX_BUSY_POLL */
6260 
6261 static void napi_hash_add(struct napi_struct *napi)
6262 {
6263 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6264 		return;
6265 
6266 	spin_lock(&napi_hash_lock);
6267 
6268 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6269 	do {
6270 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6271 			napi_gen_id = MIN_NAPI_ID;
6272 	} while (napi_by_id(napi_gen_id));
6273 	napi->napi_id = napi_gen_id;
6274 
6275 	hlist_add_head_rcu(&napi->napi_hash_node,
6276 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6277 
6278 	spin_unlock(&napi_hash_lock);
6279 }
6280 
6281 /* Warning : caller is responsible to make sure rcu grace period
6282  * is respected before freeing memory containing @napi
6283  */
6284 static void napi_hash_del(struct napi_struct *napi)
6285 {
6286 	spin_lock(&napi_hash_lock);
6287 
6288 	hlist_del_init_rcu(&napi->napi_hash_node);
6289 
6290 	spin_unlock(&napi_hash_lock);
6291 }
6292 
6293 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6294 {
6295 	struct napi_struct *napi;
6296 
6297 	napi = container_of(timer, struct napi_struct, timer);
6298 
6299 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6300 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6301 	 */
6302 	if (!napi_disable_pending(napi) &&
6303 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6304 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6305 		__napi_schedule_irqoff(napi);
6306 	}
6307 
6308 	return HRTIMER_NORESTART;
6309 }
6310 
6311 static void init_gro_hash(struct napi_struct *napi)
6312 {
6313 	int i;
6314 
6315 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6316 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6317 		napi->gro_hash[i].count = 0;
6318 	}
6319 	napi->gro_bitmask = 0;
6320 }
6321 
6322 int dev_set_threaded(struct net_device *dev, bool threaded)
6323 {
6324 	struct napi_struct *napi;
6325 	int err = 0;
6326 
6327 	if (dev->threaded == threaded)
6328 		return 0;
6329 
6330 	if (threaded) {
6331 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6332 			if (!napi->thread) {
6333 				err = napi_kthread_create(napi);
6334 				if (err) {
6335 					threaded = false;
6336 					break;
6337 				}
6338 			}
6339 		}
6340 	}
6341 
6342 	dev->threaded = threaded;
6343 
6344 	/* Make sure kthread is created before THREADED bit
6345 	 * is set.
6346 	 */
6347 	smp_mb__before_atomic();
6348 
6349 	/* Setting/unsetting threaded mode on a napi might not immediately
6350 	 * take effect, if the current napi instance is actively being
6351 	 * polled. In this case, the switch between threaded mode and
6352 	 * softirq mode will happen in the next round of napi_schedule().
6353 	 * This should not cause hiccups/stalls to the live traffic.
6354 	 */
6355 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
6356 		if (threaded)
6357 			set_bit(NAPI_STATE_THREADED, &napi->state);
6358 		else
6359 			clear_bit(NAPI_STATE_THREADED, &napi->state);
6360 	}
6361 
6362 	return err;
6363 }
6364 EXPORT_SYMBOL(dev_set_threaded);
6365 
6366 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6367 			   int (*poll)(struct napi_struct *, int), int weight)
6368 {
6369 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6370 		return;
6371 
6372 	INIT_LIST_HEAD(&napi->poll_list);
6373 	INIT_HLIST_NODE(&napi->napi_hash_node);
6374 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6375 	napi->timer.function = napi_watchdog;
6376 	init_gro_hash(napi);
6377 	napi->skb = NULL;
6378 	INIT_LIST_HEAD(&napi->rx_list);
6379 	napi->rx_count = 0;
6380 	napi->poll = poll;
6381 	if (weight > NAPI_POLL_WEIGHT)
6382 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6383 				weight);
6384 	napi->weight = weight;
6385 	napi->dev = dev;
6386 #ifdef CONFIG_NETPOLL
6387 	napi->poll_owner = -1;
6388 #endif
6389 	napi->list_owner = -1;
6390 	set_bit(NAPI_STATE_SCHED, &napi->state);
6391 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6392 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6393 	napi_hash_add(napi);
6394 	napi_get_frags_check(napi);
6395 	/* Create kthread for this napi if dev->threaded is set.
6396 	 * Clear dev->threaded if kthread creation failed so that
6397 	 * threaded mode will not be enabled in napi_enable().
6398 	 */
6399 	if (dev->threaded && napi_kthread_create(napi))
6400 		dev->threaded = 0;
6401 }
6402 EXPORT_SYMBOL(netif_napi_add_weight);
6403 
6404 void napi_disable(struct napi_struct *n)
6405 {
6406 	unsigned long val, new;
6407 
6408 	might_sleep();
6409 	set_bit(NAPI_STATE_DISABLE, &n->state);
6410 
6411 	val = READ_ONCE(n->state);
6412 	do {
6413 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6414 			usleep_range(20, 200);
6415 			val = READ_ONCE(n->state);
6416 		}
6417 
6418 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6419 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6420 	} while (!try_cmpxchg(&n->state, &val, new));
6421 
6422 	hrtimer_cancel(&n->timer);
6423 
6424 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6425 }
6426 EXPORT_SYMBOL(napi_disable);
6427 
6428 /**
6429  *	napi_enable - enable NAPI scheduling
6430  *	@n: NAPI context
6431  *
6432  * Resume NAPI from being scheduled on this context.
6433  * Must be paired with napi_disable.
6434  */
6435 void napi_enable(struct napi_struct *n)
6436 {
6437 	unsigned long new, val = READ_ONCE(n->state);
6438 
6439 	do {
6440 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6441 
6442 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6443 		if (n->dev->threaded && n->thread)
6444 			new |= NAPIF_STATE_THREADED;
6445 	} while (!try_cmpxchg(&n->state, &val, new));
6446 }
6447 EXPORT_SYMBOL(napi_enable);
6448 
6449 static void flush_gro_hash(struct napi_struct *napi)
6450 {
6451 	int i;
6452 
6453 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6454 		struct sk_buff *skb, *n;
6455 
6456 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6457 			kfree_skb(skb);
6458 		napi->gro_hash[i].count = 0;
6459 	}
6460 }
6461 
6462 /* Must be called in process context */
6463 void __netif_napi_del(struct napi_struct *napi)
6464 {
6465 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6466 		return;
6467 
6468 	napi_hash_del(napi);
6469 	list_del_rcu(&napi->dev_list);
6470 	napi_free_frags(napi);
6471 
6472 	flush_gro_hash(napi);
6473 	napi->gro_bitmask = 0;
6474 
6475 	if (napi->thread) {
6476 		kthread_stop(napi->thread);
6477 		napi->thread = NULL;
6478 	}
6479 }
6480 EXPORT_SYMBOL(__netif_napi_del);
6481 
6482 static int __napi_poll(struct napi_struct *n, bool *repoll)
6483 {
6484 	int work, weight;
6485 
6486 	weight = n->weight;
6487 
6488 	/* This NAPI_STATE_SCHED test is for avoiding a race
6489 	 * with netpoll's poll_napi().  Only the entity which
6490 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6491 	 * actually make the ->poll() call.  Therefore we avoid
6492 	 * accidentally calling ->poll() when NAPI is not scheduled.
6493 	 */
6494 	work = 0;
6495 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6496 		work = n->poll(n, weight);
6497 		trace_napi_poll(n, work, weight);
6498 	}
6499 
6500 	if (unlikely(work > weight))
6501 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6502 				n->poll, work, weight);
6503 
6504 	if (likely(work < weight))
6505 		return work;
6506 
6507 	/* Drivers must not modify the NAPI state if they
6508 	 * consume the entire weight.  In such cases this code
6509 	 * still "owns" the NAPI instance and therefore can
6510 	 * move the instance around on the list at-will.
6511 	 */
6512 	if (unlikely(napi_disable_pending(n))) {
6513 		napi_complete(n);
6514 		return work;
6515 	}
6516 
6517 	/* The NAPI context has more processing work, but busy-polling
6518 	 * is preferred. Exit early.
6519 	 */
6520 	if (napi_prefer_busy_poll(n)) {
6521 		if (napi_complete_done(n, work)) {
6522 			/* If timeout is not set, we need to make sure
6523 			 * that the NAPI is re-scheduled.
6524 			 */
6525 			napi_schedule(n);
6526 		}
6527 		return work;
6528 	}
6529 
6530 	if (n->gro_bitmask) {
6531 		/* flush too old packets
6532 		 * If HZ < 1000, flush all packets.
6533 		 */
6534 		napi_gro_flush(n, HZ >= 1000);
6535 	}
6536 
6537 	gro_normal_list(n);
6538 
6539 	/* Some drivers may have called napi_schedule
6540 	 * prior to exhausting their budget.
6541 	 */
6542 	if (unlikely(!list_empty(&n->poll_list))) {
6543 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6544 			     n->dev ? n->dev->name : "backlog");
6545 		return work;
6546 	}
6547 
6548 	*repoll = true;
6549 
6550 	return work;
6551 }
6552 
6553 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6554 {
6555 	bool do_repoll = false;
6556 	void *have;
6557 	int work;
6558 
6559 	list_del_init(&n->poll_list);
6560 
6561 	have = netpoll_poll_lock(n);
6562 
6563 	work = __napi_poll(n, &do_repoll);
6564 
6565 	if (do_repoll)
6566 		list_add_tail(&n->poll_list, repoll);
6567 
6568 	netpoll_poll_unlock(have);
6569 
6570 	return work;
6571 }
6572 
6573 static int napi_thread_wait(struct napi_struct *napi)
6574 {
6575 	bool woken = false;
6576 
6577 	set_current_state(TASK_INTERRUPTIBLE);
6578 
6579 	while (!kthread_should_stop()) {
6580 		/* Testing SCHED_THREADED bit here to make sure the current
6581 		 * kthread owns this napi and could poll on this napi.
6582 		 * Testing SCHED bit is not enough because SCHED bit might be
6583 		 * set by some other busy poll thread or by napi_disable().
6584 		 */
6585 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6586 			WARN_ON(!list_empty(&napi->poll_list));
6587 			__set_current_state(TASK_RUNNING);
6588 			return 0;
6589 		}
6590 
6591 		schedule();
6592 		/* woken being true indicates this thread owns this napi. */
6593 		woken = true;
6594 		set_current_state(TASK_INTERRUPTIBLE);
6595 	}
6596 	__set_current_state(TASK_RUNNING);
6597 
6598 	return -1;
6599 }
6600 
6601 static int napi_threaded_poll(void *data)
6602 {
6603 	struct napi_struct *napi = data;
6604 	void *have;
6605 
6606 	while (!napi_thread_wait(napi)) {
6607 		for (;;) {
6608 			bool repoll = false;
6609 
6610 			local_bh_disable();
6611 
6612 			have = netpoll_poll_lock(napi);
6613 			__napi_poll(napi, &repoll);
6614 			netpoll_poll_unlock(have);
6615 
6616 			local_bh_enable();
6617 
6618 			if (!repoll)
6619 				break;
6620 
6621 			cond_resched();
6622 		}
6623 	}
6624 	return 0;
6625 }
6626 
6627 static void skb_defer_free_flush(struct softnet_data *sd)
6628 {
6629 	struct sk_buff *skb, *next;
6630 
6631 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6632 	if (!READ_ONCE(sd->defer_list))
6633 		return;
6634 
6635 	spin_lock_irq(&sd->defer_lock);
6636 	skb = sd->defer_list;
6637 	sd->defer_list = NULL;
6638 	sd->defer_count = 0;
6639 	spin_unlock_irq(&sd->defer_lock);
6640 
6641 	while (skb != NULL) {
6642 		next = skb->next;
6643 		napi_consume_skb(skb, 1);
6644 		skb = next;
6645 	}
6646 }
6647 
6648 static __latent_entropy void net_rx_action(struct softirq_action *h)
6649 {
6650 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6651 	unsigned long time_limit = jiffies +
6652 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6653 	int budget = READ_ONCE(netdev_budget);
6654 	LIST_HEAD(list);
6655 	LIST_HEAD(repoll);
6656 
6657 start:
6658 	sd->in_net_rx_action = true;
6659 	local_irq_disable();
6660 	list_splice_init(&sd->poll_list, &list);
6661 	local_irq_enable();
6662 
6663 	for (;;) {
6664 		struct napi_struct *n;
6665 
6666 		skb_defer_free_flush(sd);
6667 
6668 		if (list_empty(&list)) {
6669 			if (list_empty(&repoll)) {
6670 				sd->in_net_rx_action = false;
6671 				barrier();
6672 				/* We need to check if ____napi_schedule()
6673 				 * had refilled poll_list while
6674 				 * sd->in_net_rx_action was true.
6675 				 */
6676 				if (!list_empty(&sd->poll_list))
6677 					goto start;
6678 				if (!sd_has_rps_ipi_waiting(sd))
6679 					goto end;
6680 			}
6681 			break;
6682 		}
6683 
6684 		n = list_first_entry(&list, struct napi_struct, poll_list);
6685 		budget -= napi_poll(n, &repoll);
6686 
6687 		/* If softirq window is exhausted then punt.
6688 		 * Allow this to run for 2 jiffies since which will allow
6689 		 * an average latency of 1.5/HZ.
6690 		 */
6691 		if (unlikely(budget <= 0 ||
6692 			     time_after_eq(jiffies, time_limit))) {
6693 			sd->time_squeeze++;
6694 			break;
6695 		}
6696 	}
6697 
6698 	local_irq_disable();
6699 
6700 	list_splice_tail_init(&sd->poll_list, &list);
6701 	list_splice_tail(&repoll, &list);
6702 	list_splice(&list, &sd->poll_list);
6703 	if (!list_empty(&sd->poll_list))
6704 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6705 	else
6706 		sd->in_net_rx_action = false;
6707 
6708 	net_rps_action_and_irq_enable(sd);
6709 end:;
6710 }
6711 
6712 struct netdev_adjacent {
6713 	struct net_device *dev;
6714 	netdevice_tracker dev_tracker;
6715 
6716 	/* upper master flag, there can only be one master device per list */
6717 	bool master;
6718 
6719 	/* lookup ignore flag */
6720 	bool ignore;
6721 
6722 	/* counter for the number of times this device was added to us */
6723 	u16 ref_nr;
6724 
6725 	/* private field for the users */
6726 	void *private;
6727 
6728 	struct list_head list;
6729 	struct rcu_head rcu;
6730 };
6731 
6732 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6733 						 struct list_head *adj_list)
6734 {
6735 	struct netdev_adjacent *adj;
6736 
6737 	list_for_each_entry(adj, adj_list, list) {
6738 		if (adj->dev == adj_dev)
6739 			return adj;
6740 	}
6741 	return NULL;
6742 }
6743 
6744 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6745 				    struct netdev_nested_priv *priv)
6746 {
6747 	struct net_device *dev = (struct net_device *)priv->data;
6748 
6749 	return upper_dev == dev;
6750 }
6751 
6752 /**
6753  * netdev_has_upper_dev - Check if device is linked to an upper device
6754  * @dev: device
6755  * @upper_dev: upper device to check
6756  *
6757  * Find out if a device is linked to specified upper device and return true
6758  * in case it is. Note that this checks only immediate upper device,
6759  * not through a complete stack of devices. The caller must hold the RTNL lock.
6760  */
6761 bool netdev_has_upper_dev(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 	ASSERT_RTNL();
6769 
6770 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6771 					     &priv);
6772 }
6773 EXPORT_SYMBOL(netdev_has_upper_dev);
6774 
6775 /**
6776  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6777  * @dev: device
6778  * @upper_dev: upper device to check
6779  *
6780  * Find out if a device is linked to specified upper device and return true
6781  * in case it is. Note that this checks the entire upper device chain.
6782  * The caller must hold rcu lock.
6783  */
6784 
6785 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6786 				  struct net_device *upper_dev)
6787 {
6788 	struct netdev_nested_priv priv = {
6789 		.data = (void *)upper_dev,
6790 	};
6791 
6792 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6793 					       &priv);
6794 }
6795 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6796 
6797 /**
6798  * netdev_has_any_upper_dev - Check if device is linked to some device
6799  * @dev: device
6800  *
6801  * Find out if a device is linked to an upper device and return true in case
6802  * it is. The caller must hold the RTNL lock.
6803  */
6804 bool netdev_has_any_upper_dev(struct net_device *dev)
6805 {
6806 	ASSERT_RTNL();
6807 
6808 	return !list_empty(&dev->adj_list.upper);
6809 }
6810 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6811 
6812 /**
6813  * netdev_master_upper_dev_get - Get master upper device
6814  * @dev: device
6815  *
6816  * Find a master upper device and return pointer to it or NULL in case
6817  * it's not there. The caller must hold the RTNL lock.
6818  */
6819 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6820 {
6821 	struct netdev_adjacent *upper;
6822 
6823 	ASSERT_RTNL();
6824 
6825 	if (list_empty(&dev->adj_list.upper))
6826 		return NULL;
6827 
6828 	upper = list_first_entry(&dev->adj_list.upper,
6829 				 struct netdev_adjacent, list);
6830 	if (likely(upper->master))
6831 		return upper->dev;
6832 	return NULL;
6833 }
6834 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6835 
6836 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6837 {
6838 	struct netdev_adjacent *upper;
6839 
6840 	ASSERT_RTNL();
6841 
6842 	if (list_empty(&dev->adj_list.upper))
6843 		return NULL;
6844 
6845 	upper = list_first_entry(&dev->adj_list.upper,
6846 				 struct netdev_adjacent, list);
6847 	if (likely(upper->master) && !upper->ignore)
6848 		return upper->dev;
6849 	return NULL;
6850 }
6851 
6852 /**
6853  * netdev_has_any_lower_dev - Check if device is linked to some device
6854  * @dev: device
6855  *
6856  * Find out if a device is linked to a lower device and return true in case
6857  * it is. The caller must hold the RTNL lock.
6858  */
6859 static bool netdev_has_any_lower_dev(struct net_device *dev)
6860 {
6861 	ASSERT_RTNL();
6862 
6863 	return !list_empty(&dev->adj_list.lower);
6864 }
6865 
6866 void *netdev_adjacent_get_private(struct list_head *adj_list)
6867 {
6868 	struct netdev_adjacent *adj;
6869 
6870 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6871 
6872 	return adj->private;
6873 }
6874 EXPORT_SYMBOL(netdev_adjacent_get_private);
6875 
6876 /**
6877  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6878  * @dev: device
6879  * @iter: list_head ** of the current position
6880  *
6881  * Gets the next device from the dev's upper list, starting from iter
6882  * position. The caller must hold RCU read lock.
6883  */
6884 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6885 						 struct list_head **iter)
6886 {
6887 	struct netdev_adjacent *upper;
6888 
6889 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6890 
6891 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6892 
6893 	if (&upper->list == &dev->adj_list.upper)
6894 		return NULL;
6895 
6896 	*iter = &upper->list;
6897 
6898 	return upper->dev;
6899 }
6900 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6901 
6902 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6903 						  struct list_head **iter,
6904 						  bool *ignore)
6905 {
6906 	struct netdev_adjacent *upper;
6907 
6908 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6909 
6910 	if (&upper->list == &dev->adj_list.upper)
6911 		return NULL;
6912 
6913 	*iter = &upper->list;
6914 	*ignore = upper->ignore;
6915 
6916 	return upper->dev;
6917 }
6918 
6919 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6920 						    struct list_head **iter)
6921 {
6922 	struct netdev_adjacent *upper;
6923 
6924 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6925 
6926 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6927 
6928 	if (&upper->list == &dev->adj_list.upper)
6929 		return NULL;
6930 
6931 	*iter = &upper->list;
6932 
6933 	return upper->dev;
6934 }
6935 
6936 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6937 				       int (*fn)(struct net_device *dev,
6938 					 struct netdev_nested_priv *priv),
6939 				       struct netdev_nested_priv *priv)
6940 {
6941 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6942 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6943 	int ret, cur = 0;
6944 	bool ignore;
6945 
6946 	now = dev;
6947 	iter = &dev->adj_list.upper;
6948 
6949 	while (1) {
6950 		if (now != dev) {
6951 			ret = fn(now, priv);
6952 			if (ret)
6953 				return ret;
6954 		}
6955 
6956 		next = NULL;
6957 		while (1) {
6958 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
6959 			if (!udev)
6960 				break;
6961 			if (ignore)
6962 				continue;
6963 
6964 			next = udev;
6965 			niter = &udev->adj_list.upper;
6966 			dev_stack[cur] = now;
6967 			iter_stack[cur++] = iter;
6968 			break;
6969 		}
6970 
6971 		if (!next) {
6972 			if (!cur)
6973 				return 0;
6974 			next = dev_stack[--cur];
6975 			niter = iter_stack[cur];
6976 		}
6977 
6978 		now = next;
6979 		iter = niter;
6980 	}
6981 
6982 	return 0;
6983 }
6984 
6985 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6986 				  int (*fn)(struct net_device *dev,
6987 					    struct netdev_nested_priv *priv),
6988 				  struct netdev_nested_priv *priv)
6989 {
6990 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6991 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6992 	int ret, cur = 0;
6993 
6994 	now = dev;
6995 	iter = &dev->adj_list.upper;
6996 
6997 	while (1) {
6998 		if (now != dev) {
6999 			ret = fn(now, priv);
7000 			if (ret)
7001 				return ret;
7002 		}
7003 
7004 		next = NULL;
7005 		while (1) {
7006 			udev = netdev_next_upper_dev_rcu(now, &iter);
7007 			if (!udev)
7008 				break;
7009 
7010 			next = udev;
7011 			niter = &udev->adj_list.upper;
7012 			dev_stack[cur] = now;
7013 			iter_stack[cur++] = iter;
7014 			break;
7015 		}
7016 
7017 		if (!next) {
7018 			if (!cur)
7019 				return 0;
7020 			next = dev_stack[--cur];
7021 			niter = iter_stack[cur];
7022 		}
7023 
7024 		now = next;
7025 		iter = niter;
7026 	}
7027 
7028 	return 0;
7029 }
7030 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7031 
7032 static bool __netdev_has_upper_dev(struct net_device *dev,
7033 				   struct net_device *upper_dev)
7034 {
7035 	struct netdev_nested_priv priv = {
7036 		.flags = 0,
7037 		.data = (void *)upper_dev,
7038 	};
7039 
7040 	ASSERT_RTNL();
7041 
7042 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7043 					   &priv);
7044 }
7045 
7046 /**
7047  * netdev_lower_get_next_private - Get the next ->private from the
7048  *				   lower neighbour list
7049  * @dev: device
7050  * @iter: list_head ** of the current position
7051  *
7052  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7053  * list, starting from iter position. The caller must hold either hold the
7054  * RTNL lock or its own locking that guarantees that the neighbour lower
7055  * list will remain unchanged.
7056  */
7057 void *netdev_lower_get_next_private(struct net_device *dev,
7058 				    struct list_head **iter)
7059 {
7060 	struct netdev_adjacent *lower;
7061 
7062 	lower = list_entry(*iter, struct netdev_adjacent, list);
7063 
7064 	if (&lower->list == &dev->adj_list.lower)
7065 		return NULL;
7066 
7067 	*iter = lower->list.next;
7068 
7069 	return lower->private;
7070 }
7071 EXPORT_SYMBOL(netdev_lower_get_next_private);
7072 
7073 /**
7074  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7075  *				       lower neighbour list, RCU
7076  *				       variant
7077  * @dev: device
7078  * @iter: list_head ** of the current position
7079  *
7080  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7081  * list, starting from iter position. The caller must hold RCU read lock.
7082  */
7083 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7084 					struct list_head **iter)
7085 {
7086 	struct netdev_adjacent *lower;
7087 
7088 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7089 
7090 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7091 
7092 	if (&lower->list == &dev->adj_list.lower)
7093 		return NULL;
7094 
7095 	*iter = &lower->list;
7096 
7097 	return lower->private;
7098 }
7099 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7100 
7101 /**
7102  * netdev_lower_get_next - Get the next device from the lower neighbour
7103  *                         list
7104  * @dev: device
7105  * @iter: list_head ** of the current position
7106  *
7107  * Gets the next netdev_adjacent from the dev's lower neighbour
7108  * list, starting from iter position. The caller must hold RTNL lock or
7109  * its own locking that guarantees that the neighbour lower
7110  * list will remain unchanged.
7111  */
7112 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7113 {
7114 	struct netdev_adjacent *lower;
7115 
7116 	lower = list_entry(*iter, struct netdev_adjacent, list);
7117 
7118 	if (&lower->list == &dev->adj_list.lower)
7119 		return NULL;
7120 
7121 	*iter = lower->list.next;
7122 
7123 	return lower->dev;
7124 }
7125 EXPORT_SYMBOL(netdev_lower_get_next);
7126 
7127 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7128 						struct list_head **iter)
7129 {
7130 	struct netdev_adjacent *lower;
7131 
7132 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7133 
7134 	if (&lower->list == &dev->adj_list.lower)
7135 		return NULL;
7136 
7137 	*iter = &lower->list;
7138 
7139 	return lower->dev;
7140 }
7141 
7142 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7143 						  struct list_head **iter,
7144 						  bool *ignore)
7145 {
7146 	struct netdev_adjacent *lower;
7147 
7148 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7149 
7150 	if (&lower->list == &dev->adj_list.lower)
7151 		return NULL;
7152 
7153 	*iter = &lower->list;
7154 	*ignore = lower->ignore;
7155 
7156 	return lower->dev;
7157 }
7158 
7159 int netdev_walk_all_lower_dev(struct net_device *dev,
7160 			      int (*fn)(struct net_device *dev,
7161 					struct netdev_nested_priv *priv),
7162 			      struct netdev_nested_priv *priv)
7163 {
7164 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7165 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7166 	int ret, cur = 0;
7167 
7168 	now = dev;
7169 	iter = &dev->adj_list.lower;
7170 
7171 	while (1) {
7172 		if (now != dev) {
7173 			ret = fn(now, priv);
7174 			if (ret)
7175 				return ret;
7176 		}
7177 
7178 		next = NULL;
7179 		while (1) {
7180 			ldev = netdev_next_lower_dev(now, &iter);
7181 			if (!ldev)
7182 				break;
7183 
7184 			next = ldev;
7185 			niter = &ldev->adj_list.lower;
7186 			dev_stack[cur] = now;
7187 			iter_stack[cur++] = iter;
7188 			break;
7189 		}
7190 
7191 		if (!next) {
7192 			if (!cur)
7193 				return 0;
7194 			next = dev_stack[--cur];
7195 			niter = iter_stack[cur];
7196 		}
7197 
7198 		now = next;
7199 		iter = niter;
7200 	}
7201 
7202 	return 0;
7203 }
7204 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7205 
7206 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7207 				       int (*fn)(struct net_device *dev,
7208 					 struct netdev_nested_priv *priv),
7209 				       struct netdev_nested_priv *priv)
7210 {
7211 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7212 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7213 	int ret, cur = 0;
7214 	bool ignore;
7215 
7216 	now = dev;
7217 	iter = &dev->adj_list.lower;
7218 
7219 	while (1) {
7220 		if (now != dev) {
7221 			ret = fn(now, priv);
7222 			if (ret)
7223 				return ret;
7224 		}
7225 
7226 		next = NULL;
7227 		while (1) {
7228 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7229 			if (!ldev)
7230 				break;
7231 			if (ignore)
7232 				continue;
7233 
7234 			next = ldev;
7235 			niter = &ldev->adj_list.lower;
7236 			dev_stack[cur] = now;
7237 			iter_stack[cur++] = iter;
7238 			break;
7239 		}
7240 
7241 		if (!next) {
7242 			if (!cur)
7243 				return 0;
7244 			next = dev_stack[--cur];
7245 			niter = iter_stack[cur];
7246 		}
7247 
7248 		now = next;
7249 		iter = niter;
7250 	}
7251 
7252 	return 0;
7253 }
7254 
7255 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7256 					     struct list_head **iter)
7257 {
7258 	struct netdev_adjacent *lower;
7259 
7260 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7261 	if (&lower->list == &dev->adj_list.lower)
7262 		return NULL;
7263 
7264 	*iter = &lower->list;
7265 
7266 	return lower->dev;
7267 }
7268 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7269 
7270 static u8 __netdev_upper_depth(struct net_device *dev)
7271 {
7272 	struct net_device *udev;
7273 	struct list_head *iter;
7274 	u8 max_depth = 0;
7275 	bool ignore;
7276 
7277 	for (iter = &dev->adj_list.upper,
7278 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7279 	     udev;
7280 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7281 		if (ignore)
7282 			continue;
7283 		if (max_depth < udev->upper_level)
7284 			max_depth = udev->upper_level;
7285 	}
7286 
7287 	return max_depth;
7288 }
7289 
7290 static u8 __netdev_lower_depth(struct net_device *dev)
7291 {
7292 	struct net_device *ldev;
7293 	struct list_head *iter;
7294 	u8 max_depth = 0;
7295 	bool ignore;
7296 
7297 	for (iter = &dev->adj_list.lower,
7298 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7299 	     ldev;
7300 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7301 		if (ignore)
7302 			continue;
7303 		if (max_depth < ldev->lower_level)
7304 			max_depth = ldev->lower_level;
7305 	}
7306 
7307 	return max_depth;
7308 }
7309 
7310 static int __netdev_update_upper_level(struct net_device *dev,
7311 				       struct netdev_nested_priv *__unused)
7312 {
7313 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7314 	return 0;
7315 }
7316 
7317 #ifdef CONFIG_LOCKDEP
7318 static LIST_HEAD(net_unlink_list);
7319 
7320 static void net_unlink_todo(struct net_device *dev)
7321 {
7322 	if (list_empty(&dev->unlink_list))
7323 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7324 }
7325 #endif
7326 
7327 static int __netdev_update_lower_level(struct net_device *dev,
7328 				       struct netdev_nested_priv *priv)
7329 {
7330 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7331 
7332 #ifdef CONFIG_LOCKDEP
7333 	if (!priv)
7334 		return 0;
7335 
7336 	if (priv->flags & NESTED_SYNC_IMM)
7337 		dev->nested_level = dev->lower_level - 1;
7338 	if (priv->flags & NESTED_SYNC_TODO)
7339 		net_unlink_todo(dev);
7340 #endif
7341 	return 0;
7342 }
7343 
7344 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7345 				  int (*fn)(struct net_device *dev,
7346 					    struct netdev_nested_priv *priv),
7347 				  struct netdev_nested_priv *priv)
7348 {
7349 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7350 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7351 	int ret, cur = 0;
7352 
7353 	now = dev;
7354 	iter = &dev->adj_list.lower;
7355 
7356 	while (1) {
7357 		if (now != dev) {
7358 			ret = fn(now, priv);
7359 			if (ret)
7360 				return ret;
7361 		}
7362 
7363 		next = NULL;
7364 		while (1) {
7365 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7366 			if (!ldev)
7367 				break;
7368 
7369 			next = ldev;
7370 			niter = &ldev->adj_list.lower;
7371 			dev_stack[cur] = now;
7372 			iter_stack[cur++] = iter;
7373 			break;
7374 		}
7375 
7376 		if (!next) {
7377 			if (!cur)
7378 				return 0;
7379 			next = dev_stack[--cur];
7380 			niter = iter_stack[cur];
7381 		}
7382 
7383 		now = next;
7384 		iter = niter;
7385 	}
7386 
7387 	return 0;
7388 }
7389 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7390 
7391 /**
7392  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7393  *				       lower neighbour list, RCU
7394  *				       variant
7395  * @dev: device
7396  *
7397  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7398  * list. The caller must hold RCU read lock.
7399  */
7400 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7401 {
7402 	struct netdev_adjacent *lower;
7403 
7404 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7405 			struct netdev_adjacent, list);
7406 	if (lower)
7407 		return lower->private;
7408 	return NULL;
7409 }
7410 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7411 
7412 /**
7413  * netdev_master_upper_dev_get_rcu - Get master upper device
7414  * @dev: device
7415  *
7416  * Find a master upper device and return pointer to it or NULL in case
7417  * it's not there. The caller must hold the RCU read lock.
7418  */
7419 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7420 {
7421 	struct netdev_adjacent *upper;
7422 
7423 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7424 				       struct netdev_adjacent, list);
7425 	if (upper && likely(upper->master))
7426 		return upper->dev;
7427 	return NULL;
7428 }
7429 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7430 
7431 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7432 			      struct net_device *adj_dev,
7433 			      struct list_head *dev_list)
7434 {
7435 	char linkname[IFNAMSIZ+7];
7436 
7437 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7438 		"upper_%s" : "lower_%s", adj_dev->name);
7439 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7440 				 linkname);
7441 }
7442 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7443 			       char *name,
7444 			       struct list_head *dev_list)
7445 {
7446 	char linkname[IFNAMSIZ+7];
7447 
7448 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7449 		"upper_%s" : "lower_%s", name);
7450 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7451 }
7452 
7453 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7454 						 struct net_device *adj_dev,
7455 						 struct list_head *dev_list)
7456 {
7457 	return (dev_list == &dev->adj_list.upper ||
7458 		dev_list == &dev->adj_list.lower) &&
7459 		net_eq(dev_net(dev), dev_net(adj_dev));
7460 }
7461 
7462 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7463 					struct net_device *adj_dev,
7464 					struct list_head *dev_list,
7465 					void *private, bool master)
7466 {
7467 	struct netdev_adjacent *adj;
7468 	int ret;
7469 
7470 	adj = __netdev_find_adj(adj_dev, dev_list);
7471 
7472 	if (adj) {
7473 		adj->ref_nr += 1;
7474 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7475 			 dev->name, adj_dev->name, adj->ref_nr);
7476 
7477 		return 0;
7478 	}
7479 
7480 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7481 	if (!adj)
7482 		return -ENOMEM;
7483 
7484 	adj->dev = adj_dev;
7485 	adj->master = master;
7486 	adj->ref_nr = 1;
7487 	adj->private = private;
7488 	adj->ignore = false;
7489 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7490 
7491 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7492 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7493 
7494 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7495 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7496 		if (ret)
7497 			goto free_adj;
7498 	}
7499 
7500 	/* Ensure that master link is always the first item in list. */
7501 	if (master) {
7502 		ret = sysfs_create_link(&(dev->dev.kobj),
7503 					&(adj_dev->dev.kobj), "master");
7504 		if (ret)
7505 			goto remove_symlinks;
7506 
7507 		list_add_rcu(&adj->list, dev_list);
7508 	} else {
7509 		list_add_tail_rcu(&adj->list, dev_list);
7510 	}
7511 
7512 	return 0;
7513 
7514 remove_symlinks:
7515 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7516 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7517 free_adj:
7518 	netdev_put(adj_dev, &adj->dev_tracker);
7519 	kfree(adj);
7520 
7521 	return ret;
7522 }
7523 
7524 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7525 					 struct net_device *adj_dev,
7526 					 u16 ref_nr,
7527 					 struct list_head *dev_list)
7528 {
7529 	struct netdev_adjacent *adj;
7530 
7531 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7532 		 dev->name, adj_dev->name, ref_nr);
7533 
7534 	adj = __netdev_find_adj(adj_dev, dev_list);
7535 
7536 	if (!adj) {
7537 		pr_err("Adjacency does not exist for device %s from %s\n",
7538 		       dev->name, adj_dev->name);
7539 		WARN_ON(1);
7540 		return;
7541 	}
7542 
7543 	if (adj->ref_nr > ref_nr) {
7544 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7545 			 dev->name, adj_dev->name, ref_nr,
7546 			 adj->ref_nr - ref_nr);
7547 		adj->ref_nr -= ref_nr;
7548 		return;
7549 	}
7550 
7551 	if (adj->master)
7552 		sysfs_remove_link(&(dev->dev.kobj), "master");
7553 
7554 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7555 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7556 
7557 	list_del_rcu(&adj->list);
7558 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7559 		 adj_dev->name, dev->name, adj_dev->name);
7560 	netdev_put(adj_dev, &adj->dev_tracker);
7561 	kfree_rcu(adj, rcu);
7562 }
7563 
7564 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7565 					    struct net_device *upper_dev,
7566 					    struct list_head *up_list,
7567 					    struct list_head *down_list,
7568 					    void *private, bool master)
7569 {
7570 	int ret;
7571 
7572 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7573 					   private, master);
7574 	if (ret)
7575 		return ret;
7576 
7577 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7578 					   private, false);
7579 	if (ret) {
7580 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7581 		return ret;
7582 	}
7583 
7584 	return 0;
7585 }
7586 
7587 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7588 					       struct net_device *upper_dev,
7589 					       u16 ref_nr,
7590 					       struct list_head *up_list,
7591 					       struct list_head *down_list)
7592 {
7593 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7594 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7595 }
7596 
7597 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7598 						struct net_device *upper_dev,
7599 						void *private, bool master)
7600 {
7601 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7602 						&dev->adj_list.upper,
7603 						&upper_dev->adj_list.lower,
7604 						private, master);
7605 }
7606 
7607 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7608 						   struct net_device *upper_dev)
7609 {
7610 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7611 					   &dev->adj_list.upper,
7612 					   &upper_dev->adj_list.lower);
7613 }
7614 
7615 static int __netdev_upper_dev_link(struct net_device *dev,
7616 				   struct net_device *upper_dev, bool master,
7617 				   void *upper_priv, void *upper_info,
7618 				   struct netdev_nested_priv *priv,
7619 				   struct netlink_ext_ack *extack)
7620 {
7621 	struct netdev_notifier_changeupper_info changeupper_info = {
7622 		.info = {
7623 			.dev = dev,
7624 			.extack = extack,
7625 		},
7626 		.upper_dev = upper_dev,
7627 		.master = master,
7628 		.linking = true,
7629 		.upper_info = upper_info,
7630 	};
7631 	struct net_device *master_dev;
7632 	int ret = 0;
7633 
7634 	ASSERT_RTNL();
7635 
7636 	if (dev == upper_dev)
7637 		return -EBUSY;
7638 
7639 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7640 	if (__netdev_has_upper_dev(upper_dev, dev))
7641 		return -EBUSY;
7642 
7643 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7644 		return -EMLINK;
7645 
7646 	if (!master) {
7647 		if (__netdev_has_upper_dev(dev, upper_dev))
7648 			return -EEXIST;
7649 	} else {
7650 		master_dev = __netdev_master_upper_dev_get(dev);
7651 		if (master_dev)
7652 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7653 	}
7654 
7655 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7656 					    &changeupper_info.info);
7657 	ret = notifier_to_errno(ret);
7658 	if (ret)
7659 		return ret;
7660 
7661 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7662 						   master);
7663 	if (ret)
7664 		return ret;
7665 
7666 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7667 					    &changeupper_info.info);
7668 	ret = notifier_to_errno(ret);
7669 	if (ret)
7670 		goto rollback;
7671 
7672 	__netdev_update_upper_level(dev, NULL);
7673 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7674 
7675 	__netdev_update_lower_level(upper_dev, priv);
7676 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7677 				    priv);
7678 
7679 	return 0;
7680 
7681 rollback:
7682 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7683 
7684 	return ret;
7685 }
7686 
7687 /**
7688  * netdev_upper_dev_link - Add a link to the upper device
7689  * @dev: device
7690  * @upper_dev: new upper device
7691  * @extack: netlink extended ack
7692  *
7693  * Adds a link to device which is upper to this one. The caller must hold
7694  * the RTNL lock. On a failure a negative errno code is returned.
7695  * On success the reference counts are adjusted and the function
7696  * returns zero.
7697  */
7698 int netdev_upper_dev_link(struct net_device *dev,
7699 			  struct net_device *upper_dev,
7700 			  struct netlink_ext_ack *extack)
7701 {
7702 	struct netdev_nested_priv priv = {
7703 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7704 		.data = NULL,
7705 	};
7706 
7707 	return __netdev_upper_dev_link(dev, upper_dev, false,
7708 				       NULL, NULL, &priv, extack);
7709 }
7710 EXPORT_SYMBOL(netdev_upper_dev_link);
7711 
7712 /**
7713  * netdev_master_upper_dev_link - Add a master link to the upper device
7714  * @dev: device
7715  * @upper_dev: new upper device
7716  * @upper_priv: upper device private
7717  * @upper_info: upper info to be passed down via notifier
7718  * @extack: netlink extended ack
7719  *
7720  * Adds a link to device which is upper to this one. In this case, only
7721  * one master upper device can be linked, although other non-master devices
7722  * might be linked as well. The caller must hold the RTNL lock.
7723  * On a failure a negative errno code is returned. On success the reference
7724  * counts are adjusted and the function returns zero.
7725  */
7726 int netdev_master_upper_dev_link(struct net_device *dev,
7727 				 struct net_device *upper_dev,
7728 				 void *upper_priv, void *upper_info,
7729 				 struct netlink_ext_ack *extack)
7730 {
7731 	struct netdev_nested_priv priv = {
7732 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7733 		.data = NULL,
7734 	};
7735 
7736 	return __netdev_upper_dev_link(dev, upper_dev, true,
7737 				       upper_priv, upper_info, &priv, extack);
7738 }
7739 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7740 
7741 static void __netdev_upper_dev_unlink(struct net_device *dev,
7742 				      struct net_device *upper_dev,
7743 				      struct netdev_nested_priv *priv)
7744 {
7745 	struct netdev_notifier_changeupper_info changeupper_info = {
7746 		.info = {
7747 			.dev = dev,
7748 		},
7749 		.upper_dev = upper_dev,
7750 		.linking = false,
7751 	};
7752 
7753 	ASSERT_RTNL();
7754 
7755 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7756 
7757 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7758 				      &changeupper_info.info);
7759 
7760 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7761 
7762 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7763 				      &changeupper_info.info);
7764 
7765 	__netdev_update_upper_level(dev, NULL);
7766 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7767 
7768 	__netdev_update_lower_level(upper_dev, priv);
7769 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7770 				    priv);
7771 }
7772 
7773 /**
7774  * netdev_upper_dev_unlink - Removes a link to upper device
7775  * @dev: device
7776  * @upper_dev: new upper device
7777  *
7778  * Removes a link to device which is upper to this one. The caller must hold
7779  * the RTNL lock.
7780  */
7781 void netdev_upper_dev_unlink(struct net_device *dev,
7782 			     struct net_device *upper_dev)
7783 {
7784 	struct netdev_nested_priv priv = {
7785 		.flags = NESTED_SYNC_TODO,
7786 		.data = NULL,
7787 	};
7788 
7789 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7790 }
7791 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7792 
7793 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7794 				      struct net_device *lower_dev,
7795 				      bool val)
7796 {
7797 	struct netdev_adjacent *adj;
7798 
7799 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7800 	if (adj)
7801 		adj->ignore = val;
7802 
7803 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7804 	if (adj)
7805 		adj->ignore = val;
7806 }
7807 
7808 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7809 					struct net_device *lower_dev)
7810 {
7811 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7812 }
7813 
7814 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7815 				       struct net_device *lower_dev)
7816 {
7817 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7818 }
7819 
7820 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7821 				   struct net_device *new_dev,
7822 				   struct net_device *dev,
7823 				   struct netlink_ext_ack *extack)
7824 {
7825 	struct netdev_nested_priv priv = {
7826 		.flags = 0,
7827 		.data = NULL,
7828 	};
7829 	int err;
7830 
7831 	if (!new_dev)
7832 		return 0;
7833 
7834 	if (old_dev && new_dev != old_dev)
7835 		netdev_adjacent_dev_disable(dev, old_dev);
7836 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7837 				      extack);
7838 	if (err) {
7839 		if (old_dev && new_dev != old_dev)
7840 			netdev_adjacent_dev_enable(dev, old_dev);
7841 		return err;
7842 	}
7843 
7844 	return 0;
7845 }
7846 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7847 
7848 void netdev_adjacent_change_commit(struct net_device *old_dev,
7849 				   struct net_device *new_dev,
7850 				   struct net_device *dev)
7851 {
7852 	struct netdev_nested_priv priv = {
7853 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7854 		.data = NULL,
7855 	};
7856 
7857 	if (!new_dev || !old_dev)
7858 		return;
7859 
7860 	if (new_dev == old_dev)
7861 		return;
7862 
7863 	netdev_adjacent_dev_enable(dev, old_dev);
7864 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7865 }
7866 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7867 
7868 void netdev_adjacent_change_abort(struct net_device *old_dev,
7869 				  struct net_device *new_dev,
7870 				  struct net_device *dev)
7871 {
7872 	struct netdev_nested_priv priv = {
7873 		.flags = 0,
7874 		.data = NULL,
7875 	};
7876 
7877 	if (!new_dev)
7878 		return;
7879 
7880 	if (old_dev && new_dev != old_dev)
7881 		netdev_adjacent_dev_enable(dev, old_dev);
7882 
7883 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7884 }
7885 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7886 
7887 /**
7888  * netdev_bonding_info_change - Dispatch event about slave change
7889  * @dev: device
7890  * @bonding_info: info to dispatch
7891  *
7892  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7893  * The caller must hold the RTNL lock.
7894  */
7895 void netdev_bonding_info_change(struct net_device *dev,
7896 				struct netdev_bonding_info *bonding_info)
7897 {
7898 	struct netdev_notifier_bonding_info info = {
7899 		.info.dev = dev,
7900 	};
7901 
7902 	memcpy(&info.bonding_info, bonding_info,
7903 	       sizeof(struct netdev_bonding_info));
7904 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7905 				      &info.info);
7906 }
7907 EXPORT_SYMBOL(netdev_bonding_info_change);
7908 
7909 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7910 					   struct netlink_ext_ack *extack)
7911 {
7912 	struct netdev_notifier_offload_xstats_info info = {
7913 		.info.dev = dev,
7914 		.info.extack = extack,
7915 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7916 	};
7917 	int err;
7918 	int rc;
7919 
7920 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7921 					 GFP_KERNEL);
7922 	if (!dev->offload_xstats_l3)
7923 		return -ENOMEM;
7924 
7925 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7926 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7927 						  &info.info);
7928 	err = notifier_to_errno(rc);
7929 	if (err)
7930 		goto free_stats;
7931 
7932 	return 0;
7933 
7934 free_stats:
7935 	kfree(dev->offload_xstats_l3);
7936 	dev->offload_xstats_l3 = NULL;
7937 	return err;
7938 }
7939 
7940 int netdev_offload_xstats_enable(struct net_device *dev,
7941 				 enum netdev_offload_xstats_type type,
7942 				 struct netlink_ext_ack *extack)
7943 {
7944 	ASSERT_RTNL();
7945 
7946 	if (netdev_offload_xstats_enabled(dev, type))
7947 		return -EALREADY;
7948 
7949 	switch (type) {
7950 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7951 		return netdev_offload_xstats_enable_l3(dev, extack);
7952 	}
7953 
7954 	WARN_ON(1);
7955 	return -EINVAL;
7956 }
7957 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7958 
7959 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7960 {
7961 	struct netdev_notifier_offload_xstats_info info = {
7962 		.info.dev = dev,
7963 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7964 	};
7965 
7966 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7967 				      &info.info);
7968 	kfree(dev->offload_xstats_l3);
7969 	dev->offload_xstats_l3 = NULL;
7970 }
7971 
7972 int netdev_offload_xstats_disable(struct net_device *dev,
7973 				  enum netdev_offload_xstats_type type)
7974 {
7975 	ASSERT_RTNL();
7976 
7977 	if (!netdev_offload_xstats_enabled(dev, type))
7978 		return -EALREADY;
7979 
7980 	switch (type) {
7981 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7982 		netdev_offload_xstats_disable_l3(dev);
7983 		return 0;
7984 	}
7985 
7986 	WARN_ON(1);
7987 	return -EINVAL;
7988 }
7989 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7990 
7991 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7992 {
7993 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7994 }
7995 
7996 static struct rtnl_hw_stats64 *
7997 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7998 			      enum netdev_offload_xstats_type type)
7999 {
8000 	switch (type) {
8001 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8002 		return dev->offload_xstats_l3;
8003 	}
8004 
8005 	WARN_ON(1);
8006 	return NULL;
8007 }
8008 
8009 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8010 				   enum netdev_offload_xstats_type type)
8011 {
8012 	ASSERT_RTNL();
8013 
8014 	return netdev_offload_xstats_get_ptr(dev, type);
8015 }
8016 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8017 
8018 struct netdev_notifier_offload_xstats_ru {
8019 	bool used;
8020 };
8021 
8022 struct netdev_notifier_offload_xstats_rd {
8023 	struct rtnl_hw_stats64 stats;
8024 	bool used;
8025 };
8026 
8027 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8028 				  const struct rtnl_hw_stats64 *src)
8029 {
8030 	dest->rx_packets	  += src->rx_packets;
8031 	dest->tx_packets	  += src->tx_packets;
8032 	dest->rx_bytes		  += src->rx_bytes;
8033 	dest->tx_bytes		  += src->tx_bytes;
8034 	dest->rx_errors		  += src->rx_errors;
8035 	dest->tx_errors		  += src->tx_errors;
8036 	dest->rx_dropped	  += src->rx_dropped;
8037 	dest->tx_dropped	  += src->tx_dropped;
8038 	dest->multicast		  += src->multicast;
8039 }
8040 
8041 static int netdev_offload_xstats_get_used(struct net_device *dev,
8042 					  enum netdev_offload_xstats_type type,
8043 					  bool *p_used,
8044 					  struct netlink_ext_ack *extack)
8045 {
8046 	struct netdev_notifier_offload_xstats_ru report_used = {};
8047 	struct netdev_notifier_offload_xstats_info info = {
8048 		.info.dev = dev,
8049 		.info.extack = extack,
8050 		.type = type,
8051 		.report_used = &report_used,
8052 	};
8053 	int rc;
8054 
8055 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8056 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8057 					   &info.info);
8058 	*p_used = report_used.used;
8059 	return notifier_to_errno(rc);
8060 }
8061 
8062 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8063 					   enum netdev_offload_xstats_type type,
8064 					   struct rtnl_hw_stats64 *p_stats,
8065 					   bool *p_used,
8066 					   struct netlink_ext_ack *extack)
8067 {
8068 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8069 	struct netdev_notifier_offload_xstats_info info = {
8070 		.info.dev = dev,
8071 		.info.extack = extack,
8072 		.type = type,
8073 		.report_delta = &report_delta,
8074 	};
8075 	struct rtnl_hw_stats64 *stats;
8076 	int rc;
8077 
8078 	stats = netdev_offload_xstats_get_ptr(dev, type);
8079 	if (WARN_ON(!stats))
8080 		return -EINVAL;
8081 
8082 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8083 					   &info.info);
8084 
8085 	/* Cache whatever we got, even if there was an error, otherwise the
8086 	 * successful stats retrievals would get lost.
8087 	 */
8088 	netdev_hw_stats64_add(stats, &report_delta.stats);
8089 
8090 	if (p_stats)
8091 		*p_stats = *stats;
8092 	*p_used = report_delta.used;
8093 
8094 	return notifier_to_errno(rc);
8095 }
8096 
8097 int netdev_offload_xstats_get(struct net_device *dev,
8098 			      enum netdev_offload_xstats_type type,
8099 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8100 			      struct netlink_ext_ack *extack)
8101 {
8102 	ASSERT_RTNL();
8103 
8104 	if (p_stats)
8105 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8106 						       p_used, extack);
8107 	else
8108 		return netdev_offload_xstats_get_used(dev, type, p_used,
8109 						      extack);
8110 }
8111 EXPORT_SYMBOL(netdev_offload_xstats_get);
8112 
8113 void
8114 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8115 				   const struct rtnl_hw_stats64 *stats)
8116 {
8117 	report_delta->used = true;
8118 	netdev_hw_stats64_add(&report_delta->stats, stats);
8119 }
8120 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8121 
8122 void
8123 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8124 {
8125 	report_used->used = true;
8126 }
8127 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8128 
8129 void netdev_offload_xstats_push_delta(struct net_device *dev,
8130 				      enum netdev_offload_xstats_type type,
8131 				      const struct rtnl_hw_stats64 *p_stats)
8132 {
8133 	struct rtnl_hw_stats64 *stats;
8134 
8135 	ASSERT_RTNL();
8136 
8137 	stats = netdev_offload_xstats_get_ptr(dev, type);
8138 	if (WARN_ON(!stats))
8139 		return;
8140 
8141 	netdev_hw_stats64_add(stats, p_stats);
8142 }
8143 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8144 
8145 /**
8146  * netdev_get_xmit_slave - Get the xmit slave of master device
8147  * @dev: device
8148  * @skb: The packet
8149  * @all_slaves: assume all the slaves are active
8150  *
8151  * The reference counters are not incremented so the caller must be
8152  * careful with locks. The caller must hold RCU lock.
8153  * %NULL is returned if no slave is found.
8154  */
8155 
8156 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8157 					 struct sk_buff *skb,
8158 					 bool all_slaves)
8159 {
8160 	const struct net_device_ops *ops = dev->netdev_ops;
8161 
8162 	if (!ops->ndo_get_xmit_slave)
8163 		return NULL;
8164 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8165 }
8166 EXPORT_SYMBOL(netdev_get_xmit_slave);
8167 
8168 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8169 						  struct sock *sk)
8170 {
8171 	const struct net_device_ops *ops = dev->netdev_ops;
8172 
8173 	if (!ops->ndo_sk_get_lower_dev)
8174 		return NULL;
8175 	return ops->ndo_sk_get_lower_dev(dev, sk);
8176 }
8177 
8178 /**
8179  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8180  * @dev: device
8181  * @sk: the socket
8182  *
8183  * %NULL is returned if no lower device is found.
8184  */
8185 
8186 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8187 					    struct sock *sk)
8188 {
8189 	struct net_device *lower;
8190 
8191 	lower = netdev_sk_get_lower_dev(dev, sk);
8192 	while (lower) {
8193 		dev = lower;
8194 		lower = netdev_sk_get_lower_dev(dev, sk);
8195 	}
8196 
8197 	return dev;
8198 }
8199 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8200 
8201 static void netdev_adjacent_add_links(struct net_device *dev)
8202 {
8203 	struct netdev_adjacent *iter;
8204 
8205 	struct net *net = dev_net(dev);
8206 
8207 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8208 		if (!net_eq(net, dev_net(iter->dev)))
8209 			continue;
8210 		netdev_adjacent_sysfs_add(iter->dev, dev,
8211 					  &iter->dev->adj_list.lower);
8212 		netdev_adjacent_sysfs_add(dev, iter->dev,
8213 					  &dev->adj_list.upper);
8214 	}
8215 
8216 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8217 		if (!net_eq(net, dev_net(iter->dev)))
8218 			continue;
8219 		netdev_adjacent_sysfs_add(iter->dev, dev,
8220 					  &iter->dev->adj_list.upper);
8221 		netdev_adjacent_sysfs_add(dev, iter->dev,
8222 					  &dev->adj_list.lower);
8223 	}
8224 }
8225 
8226 static void netdev_adjacent_del_links(struct net_device *dev)
8227 {
8228 	struct netdev_adjacent *iter;
8229 
8230 	struct net *net = dev_net(dev);
8231 
8232 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8233 		if (!net_eq(net, dev_net(iter->dev)))
8234 			continue;
8235 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8236 					  &iter->dev->adj_list.lower);
8237 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8238 					  &dev->adj_list.upper);
8239 	}
8240 
8241 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8242 		if (!net_eq(net, dev_net(iter->dev)))
8243 			continue;
8244 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8245 					  &iter->dev->adj_list.upper);
8246 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8247 					  &dev->adj_list.lower);
8248 	}
8249 }
8250 
8251 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8252 {
8253 	struct netdev_adjacent *iter;
8254 
8255 	struct net *net = dev_net(dev);
8256 
8257 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8258 		if (!net_eq(net, dev_net(iter->dev)))
8259 			continue;
8260 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8261 					  &iter->dev->adj_list.lower);
8262 		netdev_adjacent_sysfs_add(iter->dev, dev,
8263 					  &iter->dev->adj_list.lower);
8264 	}
8265 
8266 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8267 		if (!net_eq(net, dev_net(iter->dev)))
8268 			continue;
8269 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8270 					  &iter->dev->adj_list.upper);
8271 		netdev_adjacent_sysfs_add(iter->dev, dev,
8272 					  &iter->dev->adj_list.upper);
8273 	}
8274 }
8275 
8276 void *netdev_lower_dev_get_private(struct net_device *dev,
8277 				   struct net_device *lower_dev)
8278 {
8279 	struct netdev_adjacent *lower;
8280 
8281 	if (!lower_dev)
8282 		return NULL;
8283 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8284 	if (!lower)
8285 		return NULL;
8286 
8287 	return lower->private;
8288 }
8289 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8290 
8291 
8292 /**
8293  * netdev_lower_state_changed - Dispatch event about lower device state change
8294  * @lower_dev: device
8295  * @lower_state_info: state to dispatch
8296  *
8297  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8298  * The caller must hold the RTNL lock.
8299  */
8300 void netdev_lower_state_changed(struct net_device *lower_dev,
8301 				void *lower_state_info)
8302 {
8303 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8304 		.info.dev = lower_dev,
8305 	};
8306 
8307 	ASSERT_RTNL();
8308 	changelowerstate_info.lower_state_info = lower_state_info;
8309 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8310 				      &changelowerstate_info.info);
8311 }
8312 EXPORT_SYMBOL(netdev_lower_state_changed);
8313 
8314 static void dev_change_rx_flags(struct net_device *dev, int flags)
8315 {
8316 	const struct net_device_ops *ops = dev->netdev_ops;
8317 
8318 	if (ops->ndo_change_rx_flags)
8319 		ops->ndo_change_rx_flags(dev, flags);
8320 }
8321 
8322 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8323 {
8324 	unsigned int old_flags = dev->flags;
8325 	kuid_t uid;
8326 	kgid_t gid;
8327 
8328 	ASSERT_RTNL();
8329 
8330 	dev->flags |= IFF_PROMISC;
8331 	dev->promiscuity += inc;
8332 	if (dev->promiscuity == 0) {
8333 		/*
8334 		 * Avoid overflow.
8335 		 * If inc causes overflow, untouch promisc and return error.
8336 		 */
8337 		if (inc < 0)
8338 			dev->flags &= ~IFF_PROMISC;
8339 		else {
8340 			dev->promiscuity -= inc;
8341 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8342 			return -EOVERFLOW;
8343 		}
8344 	}
8345 	if (dev->flags != old_flags) {
8346 		netdev_info(dev, "%s promiscuous mode\n",
8347 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8348 		if (audit_enabled) {
8349 			current_uid_gid(&uid, &gid);
8350 			audit_log(audit_context(), GFP_ATOMIC,
8351 				  AUDIT_ANOM_PROMISCUOUS,
8352 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8353 				  dev->name, (dev->flags & IFF_PROMISC),
8354 				  (old_flags & IFF_PROMISC),
8355 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8356 				  from_kuid(&init_user_ns, uid),
8357 				  from_kgid(&init_user_ns, gid),
8358 				  audit_get_sessionid(current));
8359 		}
8360 
8361 		dev_change_rx_flags(dev, IFF_PROMISC);
8362 	}
8363 	if (notify)
8364 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8365 	return 0;
8366 }
8367 
8368 /**
8369  *	dev_set_promiscuity	- update promiscuity count on a device
8370  *	@dev: device
8371  *	@inc: modifier
8372  *
8373  *	Add or remove promiscuity from a device. While the count in the device
8374  *	remains above zero the interface remains promiscuous. Once it hits zero
8375  *	the device reverts back to normal filtering operation. A negative inc
8376  *	value is used to drop promiscuity on the device.
8377  *	Return 0 if successful or a negative errno code on error.
8378  */
8379 int dev_set_promiscuity(struct net_device *dev, int inc)
8380 {
8381 	unsigned int old_flags = dev->flags;
8382 	int err;
8383 
8384 	err = __dev_set_promiscuity(dev, inc, true);
8385 	if (err < 0)
8386 		return err;
8387 	if (dev->flags != old_flags)
8388 		dev_set_rx_mode(dev);
8389 	return err;
8390 }
8391 EXPORT_SYMBOL(dev_set_promiscuity);
8392 
8393 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8394 {
8395 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8396 
8397 	ASSERT_RTNL();
8398 
8399 	dev->flags |= IFF_ALLMULTI;
8400 	dev->allmulti += inc;
8401 	if (dev->allmulti == 0) {
8402 		/*
8403 		 * Avoid overflow.
8404 		 * If inc causes overflow, untouch allmulti and return error.
8405 		 */
8406 		if (inc < 0)
8407 			dev->flags &= ~IFF_ALLMULTI;
8408 		else {
8409 			dev->allmulti -= inc;
8410 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8411 			return -EOVERFLOW;
8412 		}
8413 	}
8414 	if (dev->flags ^ old_flags) {
8415 		netdev_info(dev, "%s allmulticast mode\n",
8416 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8417 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8418 		dev_set_rx_mode(dev);
8419 		if (notify)
8420 			__dev_notify_flags(dev, old_flags,
8421 					   dev->gflags ^ old_gflags, 0, NULL);
8422 	}
8423 	return 0;
8424 }
8425 
8426 /**
8427  *	dev_set_allmulti	- update allmulti count on a device
8428  *	@dev: device
8429  *	@inc: modifier
8430  *
8431  *	Add or remove reception of all multicast frames to a device. While the
8432  *	count in the device remains above zero the interface remains listening
8433  *	to all interfaces. Once it hits zero the device reverts back to normal
8434  *	filtering operation. A negative @inc value is used to drop the counter
8435  *	when releasing a resource needing all multicasts.
8436  *	Return 0 if successful or a negative errno code on error.
8437  */
8438 
8439 int dev_set_allmulti(struct net_device *dev, int inc)
8440 {
8441 	return __dev_set_allmulti(dev, inc, true);
8442 }
8443 EXPORT_SYMBOL(dev_set_allmulti);
8444 
8445 /*
8446  *	Upload unicast and multicast address lists to device and
8447  *	configure RX filtering. When the device doesn't support unicast
8448  *	filtering it is put in promiscuous mode while unicast addresses
8449  *	are present.
8450  */
8451 void __dev_set_rx_mode(struct net_device *dev)
8452 {
8453 	const struct net_device_ops *ops = dev->netdev_ops;
8454 
8455 	/* dev_open will call this function so the list will stay sane. */
8456 	if (!(dev->flags&IFF_UP))
8457 		return;
8458 
8459 	if (!netif_device_present(dev))
8460 		return;
8461 
8462 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8463 		/* Unicast addresses changes may only happen under the rtnl,
8464 		 * therefore calling __dev_set_promiscuity here is safe.
8465 		 */
8466 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8467 			__dev_set_promiscuity(dev, 1, false);
8468 			dev->uc_promisc = true;
8469 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8470 			__dev_set_promiscuity(dev, -1, false);
8471 			dev->uc_promisc = false;
8472 		}
8473 	}
8474 
8475 	if (ops->ndo_set_rx_mode)
8476 		ops->ndo_set_rx_mode(dev);
8477 }
8478 
8479 void dev_set_rx_mode(struct net_device *dev)
8480 {
8481 	netif_addr_lock_bh(dev);
8482 	__dev_set_rx_mode(dev);
8483 	netif_addr_unlock_bh(dev);
8484 }
8485 
8486 /**
8487  *	dev_get_flags - get flags reported to userspace
8488  *	@dev: device
8489  *
8490  *	Get the combination of flag bits exported through APIs to userspace.
8491  */
8492 unsigned int dev_get_flags(const struct net_device *dev)
8493 {
8494 	unsigned int flags;
8495 
8496 	flags = (dev->flags & ~(IFF_PROMISC |
8497 				IFF_ALLMULTI |
8498 				IFF_RUNNING |
8499 				IFF_LOWER_UP |
8500 				IFF_DORMANT)) |
8501 		(dev->gflags & (IFF_PROMISC |
8502 				IFF_ALLMULTI));
8503 
8504 	if (netif_running(dev)) {
8505 		if (netif_oper_up(dev))
8506 			flags |= IFF_RUNNING;
8507 		if (netif_carrier_ok(dev))
8508 			flags |= IFF_LOWER_UP;
8509 		if (netif_dormant(dev))
8510 			flags |= IFF_DORMANT;
8511 	}
8512 
8513 	return flags;
8514 }
8515 EXPORT_SYMBOL(dev_get_flags);
8516 
8517 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8518 		       struct netlink_ext_ack *extack)
8519 {
8520 	unsigned int old_flags = dev->flags;
8521 	int ret;
8522 
8523 	ASSERT_RTNL();
8524 
8525 	/*
8526 	 *	Set the flags on our device.
8527 	 */
8528 
8529 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8530 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8531 			       IFF_AUTOMEDIA)) |
8532 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8533 				    IFF_ALLMULTI));
8534 
8535 	/*
8536 	 *	Load in the correct multicast list now the flags have changed.
8537 	 */
8538 
8539 	if ((old_flags ^ flags) & IFF_MULTICAST)
8540 		dev_change_rx_flags(dev, IFF_MULTICAST);
8541 
8542 	dev_set_rx_mode(dev);
8543 
8544 	/*
8545 	 *	Have we downed the interface. We handle IFF_UP ourselves
8546 	 *	according to user attempts to set it, rather than blindly
8547 	 *	setting it.
8548 	 */
8549 
8550 	ret = 0;
8551 	if ((old_flags ^ flags) & IFF_UP) {
8552 		if (old_flags & IFF_UP)
8553 			__dev_close(dev);
8554 		else
8555 			ret = __dev_open(dev, extack);
8556 	}
8557 
8558 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8559 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8560 		unsigned int old_flags = dev->flags;
8561 
8562 		dev->gflags ^= IFF_PROMISC;
8563 
8564 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8565 			if (dev->flags != old_flags)
8566 				dev_set_rx_mode(dev);
8567 	}
8568 
8569 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8570 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8571 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8572 	 */
8573 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8574 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8575 
8576 		dev->gflags ^= IFF_ALLMULTI;
8577 		__dev_set_allmulti(dev, inc, false);
8578 	}
8579 
8580 	return ret;
8581 }
8582 
8583 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8584 			unsigned int gchanges, u32 portid,
8585 			const struct nlmsghdr *nlh)
8586 {
8587 	unsigned int changes = dev->flags ^ old_flags;
8588 
8589 	if (gchanges)
8590 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8591 
8592 	if (changes & IFF_UP) {
8593 		if (dev->flags & IFF_UP)
8594 			call_netdevice_notifiers(NETDEV_UP, dev);
8595 		else
8596 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8597 	}
8598 
8599 	if (dev->flags & IFF_UP &&
8600 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8601 		struct netdev_notifier_change_info change_info = {
8602 			.info = {
8603 				.dev = dev,
8604 			},
8605 			.flags_changed = changes,
8606 		};
8607 
8608 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8609 	}
8610 }
8611 
8612 /**
8613  *	dev_change_flags - change device settings
8614  *	@dev: device
8615  *	@flags: device state flags
8616  *	@extack: netlink extended ack
8617  *
8618  *	Change settings on device based state flags. The flags are
8619  *	in the userspace exported format.
8620  */
8621 int dev_change_flags(struct net_device *dev, unsigned int flags,
8622 		     struct netlink_ext_ack *extack)
8623 {
8624 	int ret;
8625 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8626 
8627 	ret = __dev_change_flags(dev, flags, extack);
8628 	if (ret < 0)
8629 		return ret;
8630 
8631 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8632 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8633 	return ret;
8634 }
8635 EXPORT_SYMBOL(dev_change_flags);
8636 
8637 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8638 {
8639 	const struct net_device_ops *ops = dev->netdev_ops;
8640 
8641 	if (ops->ndo_change_mtu)
8642 		return ops->ndo_change_mtu(dev, new_mtu);
8643 
8644 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8645 	WRITE_ONCE(dev->mtu, new_mtu);
8646 	return 0;
8647 }
8648 EXPORT_SYMBOL(__dev_set_mtu);
8649 
8650 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8651 		     struct netlink_ext_ack *extack)
8652 {
8653 	/* MTU must be positive, and in range */
8654 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8655 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8656 		return -EINVAL;
8657 	}
8658 
8659 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8660 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8661 		return -EINVAL;
8662 	}
8663 	return 0;
8664 }
8665 
8666 /**
8667  *	dev_set_mtu_ext - Change maximum transfer unit
8668  *	@dev: device
8669  *	@new_mtu: new transfer unit
8670  *	@extack: netlink extended ack
8671  *
8672  *	Change the maximum transfer size of the network device.
8673  */
8674 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8675 		    struct netlink_ext_ack *extack)
8676 {
8677 	int err, orig_mtu;
8678 
8679 	if (new_mtu == dev->mtu)
8680 		return 0;
8681 
8682 	err = dev_validate_mtu(dev, new_mtu, extack);
8683 	if (err)
8684 		return err;
8685 
8686 	if (!netif_device_present(dev))
8687 		return -ENODEV;
8688 
8689 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8690 	err = notifier_to_errno(err);
8691 	if (err)
8692 		return err;
8693 
8694 	orig_mtu = dev->mtu;
8695 	err = __dev_set_mtu(dev, new_mtu);
8696 
8697 	if (!err) {
8698 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8699 						   orig_mtu);
8700 		err = notifier_to_errno(err);
8701 		if (err) {
8702 			/* setting mtu back and notifying everyone again,
8703 			 * so that they have a chance to revert changes.
8704 			 */
8705 			__dev_set_mtu(dev, orig_mtu);
8706 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8707 						     new_mtu);
8708 		}
8709 	}
8710 	return err;
8711 }
8712 
8713 int dev_set_mtu(struct net_device *dev, int new_mtu)
8714 {
8715 	struct netlink_ext_ack extack;
8716 	int err;
8717 
8718 	memset(&extack, 0, sizeof(extack));
8719 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8720 	if (err && extack._msg)
8721 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8722 	return err;
8723 }
8724 EXPORT_SYMBOL(dev_set_mtu);
8725 
8726 /**
8727  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8728  *	@dev: device
8729  *	@new_len: new tx queue length
8730  */
8731 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8732 {
8733 	unsigned int orig_len = dev->tx_queue_len;
8734 	int res;
8735 
8736 	if (new_len != (unsigned int)new_len)
8737 		return -ERANGE;
8738 
8739 	if (new_len != orig_len) {
8740 		dev->tx_queue_len = new_len;
8741 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8742 		res = notifier_to_errno(res);
8743 		if (res)
8744 			goto err_rollback;
8745 		res = dev_qdisc_change_tx_queue_len(dev);
8746 		if (res)
8747 			goto err_rollback;
8748 	}
8749 
8750 	return 0;
8751 
8752 err_rollback:
8753 	netdev_err(dev, "refused to change device tx_queue_len\n");
8754 	dev->tx_queue_len = orig_len;
8755 	return res;
8756 }
8757 
8758 /**
8759  *	dev_set_group - Change group this device belongs to
8760  *	@dev: device
8761  *	@new_group: group this device should belong to
8762  */
8763 void dev_set_group(struct net_device *dev, int new_group)
8764 {
8765 	dev->group = new_group;
8766 }
8767 
8768 /**
8769  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8770  *	@dev: device
8771  *	@addr: new address
8772  *	@extack: netlink extended ack
8773  */
8774 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8775 			      struct netlink_ext_ack *extack)
8776 {
8777 	struct netdev_notifier_pre_changeaddr_info info = {
8778 		.info.dev = dev,
8779 		.info.extack = extack,
8780 		.dev_addr = addr,
8781 	};
8782 	int rc;
8783 
8784 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8785 	return notifier_to_errno(rc);
8786 }
8787 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8788 
8789 /**
8790  *	dev_set_mac_address - Change Media Access Control Address
8791  *	@dev: device
8792  *	@sa: new address
8793  *	@extack: netlink extended ack
8794  *
8795  *	Change the hardware (MAC) address of the device
8796  */
8797 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8798 			struct netlink_ext_ack *extack)
8799 {
8800 	const struct net_device_ops *ops = dev->netdev_ops;
8801 	int err;
8802 
8803 	if (!ops->ndo_set_mac_address)
8804 		return -EOPNOTSUPP;
8805 	if (sa->sa_family != dev->type)
8806 		return -EINVAL;
8807 	if (!netif_device_present(dev))
8808 		return -ENODEV;
8809 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8810 	if (err)
8811 		return err;
8812 	err = ops->ndo_set_mac_address(dev, sa);
8813 	if (err)
8814 		return err;
8815 	dev->addr_assign_type = NET_ADDR_SET;
8816 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8817 	add_device_randomness(dev->dev_addr, dev->addr_len);
8818 	return 0;
8819 }
8820 EXPORT_SYMBOL(dev_set_mac_address);
8821 
8822 static DECLARE_RWSEM(dev_addr_sem);
8823 
8824 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8825 			     struct netlink_ext_ack *extack)
8826 {
8827 	int ret;
8828 
8829 	down_write(&dev_addr_sem);
8830 	ret = dev_set_mac_address(dev, sa, extack);
8831 	up_write(&dev_addr_sem);
8832 	return ret;
8833 }
8834 EXPORT_SYMBOL(dev_set_mac_address_user);
8835 
8836 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8837 {
8838 	size_t size = sizeof(sa->sa_data_min);
8839 	struct net_device *dev;
8840 	int ret = 0;
8841 
8842 	down_read(&dev_addr_sem);
8843 	rcu_read_lock();
8844 
8845 	dev = dev_get_by_name_rcu(net, dev_name);
8846 	if (!dev) {
8847 		ret = -ENODEV;
8848 		goto unlock;
8849 	}
8850 	if (!dev->addr_len)
8851 		memset(sa->sa_data, 0, size);
8852 	else
8853 		memcpy(sa->sa_data, dev->dev_addr,
8854 		       min_t(size_t, size, dev->addr_len));
8855 	sa->sa_family = dev->type;
8856 
8857 unlock:
8858 	rcu_read_unlock();
8859 	up_read(&dev_addr_sem);
8860 	return ret;
8861 }
8862 EXPORT_SYMBOL(dev_get_mac_address);
8863 
8864 /**
8865  *	dev_change_carrier - Change device carrier
8866  *	@dev: device
8867  *	@new_carrier: new value
8868  *
8869  *	Change device carrier
8870  */
8871 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8872 {
8873 	const struct net_device_ops *ops = dev->netdev_ops;
8874 
8875 	if (!ops->ndo_change_carrier)
8876 		return -EOPNOTSUPP;
8877 	if (!netif_device_present(dev))
8878 		return -ENODEV;
8879 	return ops->ndo_change_carrier(dev, new_carrier);
8880 }
8881 
8882 /**
8883  *	dev_get_phys_port_id - Get device physical port ID
8884  *	@dev: device
8885  *	@ppid: port ID
8886  *
8887  *	Get device physical port ID
8888  */
8889 int dev_get_phys_port_id(struct net_device *dev,
8890 			 struct netdev_phys_item_id *ppid)
8891 {
8892 	const struct net_device_ops *ops = dev->netdev_ops;
8893 
8894 	if (!ops->ndo_get_phys_port_id)
8895 		return -EOPNOTSUPP;
8896 	return ops->ndo_get_phys_port_id(dev, ppid);
8897 }
8898 
8899 /**
8900  *	dev_get_phys_port_name - Get device physical port name
8901  *	@dev: device
8902  *	@name: port name
8903  *	@len: limit of bytes to copy to name
8904  *
8905  *	Get device physical port name
8906  */
8907 int dev_get_phys_port_name(struct net_device *dev,
8908 			   char *name, size_t len)
8909 {
8910 	const struct net_device_ops *ops = dev->netdev_ops;
8911 	int err;
8912 
8913 	if (ops->ndo_get_phys_port_name) {
8914 		err = ops->ndo_get_phys_port_name(dev, name, len);
8915 		if (err != -EOPNOTSUPP)
8916 			return err;
8917 	}
8918 	return devlink_compat_phys_port_name_get(dev, name, len);
8919 }
8920 
8921 /**
8922  *	dev_get_port_parent_id - Get the device's port parent identifier
8923  *	@dev: network device
8924  *	@ppid: pointer to a storage for the port's parent identifier
8925  *	@recurse: allow/disallow recursion to lower devices
8926  *
8927  *	Get the devices's port parent identifier
8928  */
8929 int dev_get_port_parent_id(struct net_device *dev,
8930 			   struct netdev_phys_item_id *ppid,
8931 			   bool recurse)
8932 {
8933 	const struct net_device_ops *ops = dev->netdev_ops;
8934 	struct netdev_phys_item_id first = { };
8935 	struct net_device *lower_dev;
8936 	struct list_head *iter;
8937 	int err;
8938 
8939 	if (ops->ndo_get_port_parent_id) {
8940 		err = ops->ndo_get_port_parent_id(dev, ppid);
8941 		if (err != -EOPNOTSUPP)
8942 			return err;
8943 	}
8944 
8945 	err = devlink_compat_switch_id_get(dev, ppid);
8946 	if (!recurse || err != -EOPNOTSUPP)
8947 		return err;
8948 
8949 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
8950 		err = dev_get_port_parent_id(lower_dev, ppid, true);
8951 		if (err)
8952 			break;
8953 		if (!first.id_len)
8954 			first = *ppid;
8955 		else if (memcmp(&first, ppid, sizeof(*ppid)))
8956 			return -EOPNOTSUPP;
8957 	}
8958 
8959 	return err;
8960 }
8961 EXPORT_SYMBOL(dev_get_port_parent_id);
8962 
8963 /**
8964  *	netdev_port_same_parent_id - Indicate if two network devices have
8965  *	the same port parent identifier
8966  *	@a: first network device
8967  *	@b: second network device
8968  */
8969 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8970 {
8971 	struct netdev_phys_item_id a_id = { };
8972 	struct netdev_phys_item_id b_id = { };
8973 
8974 	if (dev_get_port_parent_id(a, &a_id, true) ||
8975 	    dev_get_port_parent_id(b, &b_id, true))
8976 		return false;
8977 
8978 	return netdev_phys_item_id_same(&a_id, &b_id);
8979 }
8980 EXPORT_SYMBOL(netdev_port_same_parent_id);
8981 
8982 /**
8983  *	dev_change_proto_down - set carrier according to proto_down.
8984  *
8985  *	@dev: device
8986  *	@proto_down: new value
8987  */
8988 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8989 {
8990 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8991 		return -EOPNOTSUPP;
8992 	if (!netif_device_present(dev))
8993 		return -ENODEV;
8994 	if (proto_down)
8995 		netif_carrier_off(dev);
8996 	else
8997 		netif_carrier_on(dev);
8998 	dev->proto_down = proto_down;
8999 	return 0;
9000 }
9001 
9002 /**
9003  *	dev_change_proto_down_reason - proto down reason
9004  *
9005  *	@dev: device
9006  *	@mask: proto down mask
9007  *	@value: proto down value
9008  */
9009 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9010 				  u32 value)
9011 {
9012 	int b;
9013 
9014 	if (!mask) {
9015 		dev->proto_down_reason = value;
9016 	} else {
9017 		for_each_set_bit(b, &mask, 32) {
9018 			if (value & (1 << b))
9019 				dev->proto_down_reason |= BIT(b);
9020 			else
9021 				dev->proto_down_reason &= ~BIT(b);
9022 		}
9023 	}
9024 }
9025 
9026 struct bpf_xdp_link {
9027 	struct bpf_link link;
9028 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9029 	int flags;
9030 };
9031 
9032 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9033 {
9034 	if (flags & XDP_FLAGS_HW_MODE)
9035 		return XDP_MODE_HW;
9036 	if (flags & XDP_FLAGS_DRV_MODE)
9037 		return XDP_MODE_DRV;
9038 	if (flags & XDP_FLAGS_SKB_MODE)
9039 		return XDP_MODE_SKB;
9040 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9041 }
9042 
9043 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9044 {
9045 	switch (mode) {
9046 	case XDP_MODE_SKB:
9047 		return generic_xdp_install;
9048 	case XDP_MODE_DRV:
9049 	case XDP_MODE_HW:
9050 		return dev->netdev_ops->ndo_bpf;
9051 	default:
9052 		return NULL;
9053 	}
9054 }
9055 
9056 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9057 					 enum bpf_xdp_mode mode)
9058 {
9059 	return dev->xdp_state[mode].link;
9060 }
9061 
9062 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9063 				     enum bpf_xdp_mode mode)
9064 {
9065 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9066 
9067 	if (link)
9068 		return link->link.prog;
9069 	return dev->xdp_state[mode].prog;
9070 }
9071 
9072 u8 dev_xdp_prog_count(struct net_device *dev)
9073 {
9074 	u8 count = 0;
9075 	int i;
9076 
9077 	for (i = 0; i < __MAX_XDP_MODE; i++)
9078 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9079 			count++;
9080 	return count;
9081 }
9082 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9083 
9084 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9085 {
9086 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9087 
9088 	return prog ? prog->aux->id : 0;
9089 }
9090 
9091 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9092 			     struct bpf_xdp_link *link)
9093 {
9094 	dev->xdp_state[mode].link = link;
9095 	dev->xdp_state[mode].prog = NULL;
9096 }
9097 
9098 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9099 			     struct bpf_prog *prog)
9100 {
9101 	dev->xdp_state[mode].link = NULL;
9102 	dev->xdp_state[mode].prog = prog;
9103 }
9104 
9105 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9106 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9107 			   u32 flags, struct bpf_prog *prog)
9108 {
9109 	struct netdev_bpf xdp;
9110 	int err;
9111 
9112 	memset(&xdp, 0, sizeof(xdp));
9113 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9114 	xdp.extack = extack;
9115 	xdp.flags = flags;
9116 	xdp.prog = prog;
9117 
9118 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9119 	 * "moved" into driver), so they don't increment it on their own, but
9120 	 * they do decrement refcnt when program is detached or replaced.
9121 	 * Given net_device also owns link/prog, we need to bump refcnt here
9122 	 * to prevent drivers from underflowing it.
9123 	 */
9124 	if (prog)
9125 		bpf_prog_inc(prog);
9126 	err = bpf_op(dev, &xdp);
9127 	if (err) {
9128 		if (prog)
9129 			bpf_prog_put(prog);
9130 		return err;
9131 	}
9132 
9133 	if (mode != XDP_MODE_HW)
9134 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9135 
9136 	return 0;
9137 }
9138 
9139 static void dev_xdp_uninstall(struct net_device *dev)
9140 {
9141 	struct bpf_xdp_link *link;
9142 	struct bpf_prog *prog;
9143 	enum bpf_xdp_mode mode;
9144 	bpf_op_t bpf_op;
9145 
9146 	ASSERT_RTNL();
9147 
9148 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9149 		prog = dev_xdp_prog(dev, mode);
9150 		if (!prog)
9151 			continue;
9152 
9153 		bpf_op = dev_xdp_bpf_op(dev, mode);
9154 		if (!bpf_op)
9155 			continue;
9156 
9157 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9158 
9159 		/* auto-detach link from net device */
9160 		link = dev_xdp_link(dev, mode);
9161 		if (link)
9162 			link->dev = NULL;
9163 		else
9164 			bpf_prog_put(prog);
9165 
9166 		dev_xdp_set_link(dev, mode, NULL);
9167 	}
9168 }
9169 
9170 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9171 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9172 			  struct bpf_prog *old_prog, u32 flags)
9173 {
9174 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9175 	struct bpf_prog *cur_prog;
9176 	struct net_device *upper;
9177 	struct list_head *iter;
9178 	enum bpf_xdp_mode mode;
9179 	bpf_op_t bpf_op;
9180 	int err;
9181 
9182 	ASSERT_RTNL();
9183 
9184 	/* either link or prog attachment, never both */
9185 	if (link && (new_prog || old_prog))
9186 		return -EINVAL;
9187 	/* link supports only XDP mode flags */
9188 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9189 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9190 		return -EINVAL;
9191 	}
9192 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9193 	if (num_modes > 1) {
9194 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9195 		return -EINVAL;
9196 	}
9197 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9198 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9199 		NL_SET_ERR_MSG(extack,
9200 			       "More than one program loaded, unset mode is ambiguous");
9201 		return -EINVAL;
9202 	}
9203 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9204 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9205 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9206 		return -EINVAL;
9207 	}
9208 
9209 	mode = dev_xdp_mode(dev, flags);
9210 	/* can't replace attached link */
9211 	if (dev_xdp_link(dev, mode)) {
9212 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9213 		return -EBUSY;
9214 	}
9215 
9216 	/* don't allow if an upper device already has a program */
9217 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9218 		if (dev_xdp_prog_count(upper) > 0) {
9219 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9220 			return -EEXIST;
9221 		}
9222 	}
9223 
9224 	cur_prog = dev_xdp_prog(dev, mode);
9225 	/* can't replace attached prog with link */
9226 	if (link && cur_prog) {
9227 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9228 		return -EBUSY;
9229 	}
9230 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9231 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9232 		return -EEXIST;
9233 	}
9234 
9235 	/* put effective new program into new_prog */
9236 	if (link)
9237 		new_prog = link->link.prog;
9238 
9239 	if (new_prog) {
9240 		bool offload = mode == XDP_MODE_HW;
9241 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9242 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9243 
9244 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9245 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9246 			return -EBUSY;
9247 		}
9248 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9249 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9250 			return -EEXIST;
9251 		}
9252 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9253 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9254 			return -EINVAL;
9255 		}
9256 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9257 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9258 			return -EINVAL;
9259 		}
9260 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9261 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9262 			return -EINVAL;
9263 		}
9264 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9265 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9266 			return -EINVAL;
9267 		}
9268 	}
9269 
9270 	/* don't call drivers if the effective program didn't change */
9271 	if (new_prog != cur_prog) {
9272 		bpf_op = dev_xdp_bpf_op(dev, mode);
9273 		if (!bpf_op) {
9274 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9275 			return -EOPNOTSUPP;
9276 		}
9277 
9278 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9279 		if (err)
9280 			return err;
9281 	}
9282 
9283 	if (link)
9284 		dev_xdp_set_link(dev, mode, link);
9285 	else
9286 		dev_xdp_set_prog(dev, mode, new_prog);
9287 	if (cur_prog)
9288 		bpf_prog_put(cur_prog);
9289 
9290 	return 0;
9291 }
9292 
9293 static int dev_xdp_attach_link(struct net_device *dev,
9294 			       struct netlink_ext_ack *extack,
9295 			       struct bpf_xdp_link *link)
9296 {
9297 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9298 }
9299 
9300 static int dev_xdp_detach_link(struct net_device *dev,
9301 			       struct netlink_ext_ack *extack,
9302 			       struct bpf_xdp_link *link)
9303 {
9304 	enum bpf_xdp_mode mode;
9305 	bpf_op_t bpf_op;
9306 
9307 	ASSERT_RTNL();
9308 
9309 	mode = dev_xdp_mode(dev, link->flags);
9310 	if (dev_xdp_link(dev, mode) != link)
9311 		return -EINVAL;
9312 
9313 	bpf_op = dev_xdp_bpf_op(dev, mode);
9314 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9315 	dev_xdp_set_link(dev, mode, NULL);
9316 	return 0;
9317 }
9318 
9319 static void bpf_xdp_link_release(struct bpf_link *link)
9320 {
9321 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9322 
9323 	rtnl_lock();
9324 
9325 	/* if racing with net_device's tear down, xdp_link->dev might be
9326 	 * already NULL, in which case link was already auto-detached
9327 	 */
9328 	if (xdp_link->dev) {
9329 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9330 		xdp_link->dev = NULL;
9331 	}
9332 
9333 	rtnl_unlock();
9334 }
9335 
9336 static int bpf_xdp_link_detach(struct bpf_link *link)
9337 {
9338 	bpf_xdp_link_release(link);
9339 	return 0;
9340 }
9341 
9342 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9343 {
9344 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9345 
9346 	kfree(xdp_link);
9347 }
9348 
9349 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9350 				     struct seq_file *seq)
9351 {
9352 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9353 	u32 ifindex = 0;
9354 
9355 	rtnl_lock();
9356 	if (xdp_link->dev)
9357 		ifindex = xdp_link->dev->ifindex;
9358 	rtnl_unlock();
9359 
9360 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9361 }
9362 
9363 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9364 				       struct bpf_link_info *info)
9365 {
9366 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9367 	u32 ifindex = 0;
9368 
9369 	rtnl_lock();
9370 	if (xdp_link->dev)
9371 		ifindex = xdp_link->dev->ifindex;
9372 	rtnl_unlock();
9373 
9374 	info->xdp.ifindex = ifindex;
9375 	return 0;
9376 }
9377 
9378 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9379 			       struct bpf_prog *old_prog)
9380 {
9381 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9382 	enum bpf_xdp_mode mode;
9383 	bpf_op_t bpf_op;
9384 	int err = 0;
9385 
9386 	rtnl_lock();
9387 
9388 	/* link might have been auto-released already, so fail */
9389 	if (!xdp_link->dev) {
9390 		err = -ENOLINK;
9391 		goto out_unlock;
9392 	}
9393 
9394 	if (old_prog && link->prog != old_prog) {
9395 		err = -EPERM;
9396 		goto out_unlock;
9397 	}
9398 	old_prog = link->prog;
9399 	if (old_prog->type != new_prog->type ||
9400 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9401 		err = -EINVAL;
9402 		goto out_unlock;
9403 	}
9404 
9405 	if (old_prog == new_prog) {
9406 		/* no-op, don't disturb drivers */
9407 		bpf_prog_put(new_prog);
9408 		goto out_unlock;
9409 	}
9410 
9411 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9412 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9413 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9414 			      xdp_link->flags, new_prog);
9415 	if (err)
9416 		goto out_unlock;
9417 
9418 	old_prog = xchg(&link->prog, new_prog);
9419 	bpf_prog_put(old_prog);
9420 
9421 out_unlock:
9422 	rtnl_unlock();
9423 	return err;
9424 }
9425 
9426 static const struct bpf_link_ops bpf_xdp_link_lops = {
9427 	.release = bpf_xdp_link_release,
9428 	.dealloc = bpf_xdp_link_dealloc,
9429 	.detach = bpf_xdp_link_detach,
9430 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9431 	.fill_link_info = bpf_xdp_link_fill_link_info,
9432 	.update_prog = bpf_xdp_link_update,
9433 };
9434 
9435 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9436 {
9437 	struct net *net = current->nsproxy->net_ns;
9438 	struct bpf_link_primer link_primer;
9439 	struct bpf_xdp_link *link;
9440 	struct net_device *dev;
9441 	int err, fd;
9442 
9443 	rtnl_lock();
9444 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9445 	if (!dev) {
9446 		rtnl_unlock();
9447 		return -EINVAL;
9448 	}
9449 
9450 	link = kzalloc(sizeof(*link), GFP_USER);
9451 	if (!link) {
9452 		err = -ENOMEM;
9453 		goto unlock;
9454 	}
9455 
9456 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9457 	link->dev = dev;
9458 	link->flags = attr->link_create.flags;
9459 
9460 	err = bpf_link_prime(&link->link, &link_primer);
9461 	if (err) {
9462 		kfree(link);
9463 		goto unlock;
9464 	}
9465 
9466 	err = dev_xdp_attach_link(dev, NULL, link);
9467 	rtnl_unlock();
9468 
9469 	if (err) {
9470 		link->dev = NULL;
9471 		bpf_link_cleanup(&link_primer);
9472 		goto out_put_dev;
9473 	}
9474 
9475 	fd = bpf_link_settle(&link_primer);
9476 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9477 	dev_put(dev);
9478 	return fd;
9479 
9480 unlock:
9481 	rtnl_unlock();
9482 
9483 out_put_dev:
9484 	dev_put(dev);
9485 	return err;
9486 }
9487 
9488 /**
9489  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9490  *	@dev: device
9491  *	@extack: netlink extended ack
9492  *	@fd: new program fd or negative value to clear
9493  *	@expected_fd: old program fd that userspace expects to replace or clear
9494  *	@flags: xdp-related flags
9495  *
9496  *	Set or clear a bpf program for a device
9497  */
9498 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9499 		      int fd, int expected_fd, u32 flags)
9500 {
9501 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9502 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9503 	int err;
9504 
9505 	ASSERT_RTNL();
9506 
9507 	if (fd >= 0) {
9508 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9509 						 mode != XDP_MODE_SKB);
9510 		if (IS_ERR(new_prog))
9511 			return PTR_ERR(new_prog);
9512 	}
9513 
9514 	if (expected_fd >= 0) {
9515 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9516 						 mode != XDP_MODE_SKB);
9517 		if (IS_ERR(old_prog)) {
9518 			err = PTR_ERR(old_prog);
9519 			old_prog = NULL;
9520 			goto err_out;
9521 		}
9522 	}
9523 
9524 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9525 
9526 err_out:
9527 	if (err && new_prog)
9528 		bpf_prog_put(new_prog);
9529 	if (old_prog)
9530 		bpf_prog_put(old_prog);
9531 	return err;
9532 }
9533 
9534 /**
9535  *	dev_new_index	-	allocate an ifindex
9536  *	@net: the applicable net namespace
9537  *
9538  *	Returns a suitable unique value for a new device interface
9539  *	number.  The caller must hold the rtnl semaphore or the
9540  *	dev_base_lock to be sure it remains unique.
9541  */
9542 static int dev_new_index(struct net *net)
9543 {
9544 	int ifindex = net->ifindex;
9545 
9546 	for (;;) {
9547 		if (++ifindex <= 0)
9548 			ifindex = 1;
9549 		if (!__dev_get_by_index(net, ifindex))
9550 			return net->ifindex = ifindex;
9551 	}
9552 }
9553 
9554 /* Delayed registration/unregisteration */
9555 LIST_HEAD(net_todo_list);
9556 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9557 
9558 static void net_set_todo(struct net_device *dev)
9559 {
9560 	list_add_tail(&dev->todo_list, &net_todo_list);
9561 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9562 }
9563 
9564 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9565 	struct net_device *upper, netdev_features_t features)
9566 {
9567 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9568 	netdev_features_t feature;
9569 	int feature_bit;
9570 
9571 	for_each_netdev_feature(upper_disables, feature_bit) {
9572 		feature = __NETIF_F_BIT(feature_bit);
9573 		if (!(upper->wanted_features & feature)
9574 		    && (features & feature)) {
9575 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9576 				   &feature, upper->name);
9577 			features &= ~feature;
9578 		}
9579 	}
9580 
9581 	return features;
9582 }
9583 
9584 static void netdev_sync_lower_features(struct net_device *upper,
9585 	struct net_device *lower, netdev_features_t features)
9586 {
9587 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9588 	netdev_features_t feature;
9589 	int feature_bit;
9590 
9591 	for_each_netdev_feature(upper_disables, feature_bit) {
9592 		feature = __NETIF_F_BIT(feature_bit);
9593 		if (!(features & feature) && (lower->features & feature)) {
9594 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9595 				   &feature, lower->name);
9596 			lower->wanted_features &= ~feature;
9597 			__netdev_update_features(lower);
9598 
9599 			if (unlikely(lower->features & feature))
9600 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9601 					    &feature, lower->name);
9602 			else
9603 				netdev_features_change(lower);
9604 		}
9605 	}
9606 }
9607 
9608 static netdev_features_t netdev_fix_features(struct net_device *dev,
9609 	netdev_features_t features)
9610 {
9611 	/* Fix illegal checksum combinations */
9612 	if ((features & NETIF_F_HW_CSUM) &&
9613 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9614 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9615 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9616 	}
9617 
9618 	/* TSO requires that SG is present as well. */
9619 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9620 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9621 		features &= ~NETIF_F_ALL_TSO;
9622 	}
9623 
9624 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9625 					!(features & NETIF_F_IP_CSUM)) {
9626 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9627 		features &= ~NETIF_F_TSO;
9628 		features &= ~NETIF_F_TSO_ECN;
9629 	}
9630 
9631 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9632 					 !(features & NETIF_F_IPV6_CSUM)) {
9633 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9634 		features &= ~NETIF_F_TSO6;
9635 	}
9636 
9637 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9638 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9639 		features &= ~NETIF_F_TSO_MANGLEID;
9640 
9641 	/* TSO ECN requires that TSO is present as well. */
9642 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9643 		features &= ~NETIF_F_TSO_ECN;
9644 
9645 	/* Software GSO depends on SG. */
9646 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9647 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9648 		features &= ~NETIF_F_GSO;
9649 	}
9650 
9651 	/* GSO partial features require GSO partial be set */
9652 	if ((features & dev->gso_partial_features) &&
9653 	    !(features & NETIF_F_GSO_PARTIAL)) {
9654 		netdev_dbg(dev,
9655 			   "Dropping partially supported GSO features since no GSO partial.\n");
9656 		features &= ~dev->gso_partial_features;
9657 	}
9658 
9659 	if (!(features & NETIF_F_RXCSUM)) {
9660 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9661 		 * successfully merged by hardware must also have the
9662 		 * checksum verified by hardware.  If the user does not
9663 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9664 		 */
9665 		if (features & NETIF_F_GRO_HW) {
9666 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9667 			features &= ~NETIF_F_GRO_HW;
9668 		}
9669 	}
9670 
9671 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9672 	if (features & NETIF_F_RXFCS) {
9673 		if (features & NETIF_F_LRO) {
9674 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9675 			features &= ~NETIF_F_LRO;
9676 		}
9677 
9678 		if (features & NETIF_F_GRO_HW) {
9679 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9680 			features &= ~NETIF_F_GRO_HW;
9681 		}
9682 	}
9683 
9684 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9685 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9686 		features &= ~NETIF_F_LRO;
9687 	}
9688 
9689 	if (features & NETIF_F_HW_TLS_TX) {
9690 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9691 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9692 		bool hw_csum = features & NETIF_F_HW_CSUM;
9693 
9694 		if (!ip_csum && !hw_csum) {
9695 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9696 			features &= ~NETIF_F_HW_TLS_TX;
9697 		}
9698 	}
9699 
9700 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9701 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9702 		features &= ~NETIF_F_HW_TLS_RX;
9703 	}
9704 
9705 	return features;
9706 }
9707 
9708 int __netdev_update_features(struct net_device *dev)
9709 {
9710 	struct net_device *upper, *lower;
9711 	netdev_features_t features;
9712 	struct list_head *iter;
9713 	int err = -1;
9714 
9715 	ASSERT_RTNL();
9716 
9717 	features = netdev_get_wanted_features(dev);
9718 
9719 	if (dev->netdev_ops->ndo_fix_features)
9720 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9721 
9722 	/* driver might be less strict about feature dependencies */
9723 	features = netdev_fix_features(dev, features);
9724 
9725 	/* some features can't be enabled if they're off on an upper device */
9726 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9727 		features = netdev_sync_upper_features(dev, upper, features);
9728 
9729 	if (dev->features == features)
9730 		goto sync_lower;
9731 
9732 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9733 		&dev->features, &features);
9734 
9735 	if (dev->netdev_ops->ndo_set_features)
9736 		err = dev->netdev_ops->ndo_set_features(dev, features);
9737 	else
9738 		err = 0;
9739 
9740 	if (unlikely(err < 0)) {
9741 		netdev_err(dev,
9742 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9743 			err, &features, &dev->features);
9744 		/* return non-0 since some features might have changed and
9745 		 * it's better to fire a spurious notification than miss it
9746 		 */
9747 		return -1;
9748 	}
9749 
9750 sync_lower:
9751 	/* some features must be disabled on lower devices when disabled
9752 	 * on an upper device (think: bonding master or bridge)
9753 	 */
9754 	netdev_for_each_lower_dev(dev, lower, iter)
9755 		netdev_sync_lower_features(dev, lower, features);
9756 
9757 	if (!err) {
9758 		netdev_features_t diff = features ^ dev->features;
9759 
9760 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9761 			/* udp_tunnel_{get,drop}_rx_info both need
9762 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9763 			 * device, or they won't do anything.
9764 			 * Thus we need to update dev->features
9765 			 * *before* calling udp_tunnel_get_rx_info,
9766 			 * but *after* calling udp_tunnel_drop_rx_info.
9767 			 */
9768 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9769 				dev->features = features;
9770 				udp_tunnel_get_rx_info(dev);
9771 			} else {
9772 				udp_tunnel_drop_rx_info(dev);
9773 			}
9774 		}
9775 
9776 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9777 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9778 				dev->features = features;
9779 				err |= vlan_get_rx_ctag_filter_info(dev);
9780 			} else {
9781 				vlan_drop_rx_ctag_filter_info(dev);
9782 			}
9783 		}
9784 
9785 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9786 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9787 				dev->features = features;
9788 				err |= vlan_get_rx_stag_filter_info(dev);
9789 			} else {
9790 				vlan_drop_rx_stag_filter_info(dev);
9791 			}
9792 		}
9793 
9794 		dev->features = features;
9795 	}
9796 
9797 	return err < 0 ? 0 : 1;
9798 }
9799 
9800 /**
9801  *	netdev_update_features - recalculate device features
9802  *	@dev: the device to check
9803  *
9804  *	Recalculate dev->features set and send notifications if it
9805  *	has changed. Should be called after driver or hardware dependent
9806  *	conditions might have changed that influence the features.
9807  */
9808 void netdev_update_features(struct net_device *dev)
9809 {
9810 	if (__netdev_update_features(dev))
9811 		netdev_features_change(dev);
9812 }
9813 EXPORT_SYMBOL(netdev_update_features);
9814 
9815 /**
9816  *	netdev_change_features - recalculate device features
9817  *	@dev: the device to check
9818  *
9819  *	Recalculate dev->features set and send notifications even
9820  *	if they have not changed. Should be called instead of
9821  *	netdev_update_features() if also dev->vlan_features might
9822  *	have changed to allow the changes to be propagated to stacked
9823  *	VLAN devices.
9824  */
9825 void netdev_change_features(struct net_device *dev)
9826 {
9827 	__netdev_update_features(dev);
9828 	netdev_features_change(dev);
9829 }
9830 EXPORT_SYMBOL(netdev_change_features);
9831 
9832 /**
9833  *	netif_stacked_transfer_operstate -	transfer operstate
9834  *	@rootdev: the root or lower level device to transfer state from
9835  *	@dev: the device to transfer operstate to
9836  *
9837  *	Transfer operational state from root to device. This is normally
9838  *	called when a stacking relationship exists between the root
9839  *	device and the device(a leaf device).
9840  */
9841 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9842 					struct net_device *dev)
9843 {
9844 	if (rootdev->operstate == IF_OPER_DORMANT)
9845 		netif_dormant_on(dev);
9846 	else
9847 		netif_dormant_off(dev);
9848 
9849 	if (rootdev->operstate == IF_OPER_TESTING)
9850 		netif_testing_on(dev);
9851 	else
9852 		netif_testing_off(dev);
9853 
9854 	if (netif_carrier_ok(rootdev))
9855 		netif_carrier_on(dev);
9856 	else
9857 		netif_carrier_off(dev);
9858 }
9859 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9860 
9861 static int netif_alloc_rx_queues(struct net_device *dev)
9862 {
9863 	unsigned int i, count = dev->num_rx_queues;
9864 	struct netdev_rx_queue *rx;
9865 	size_t sz = count * sizeof(*rx);
9866 	int err = 0;
9867 
9868 	BUG_ON(count < 1);
9869 
9870 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9871 	if (!rx)
9872 		return -ENOMEM;
9873 
9874 	dev->_rx = rx;
9875 
9876 	for (i = 0; i < count; i++) {
9877 		rx[i].dev = dev;
9878 
9879 		/* XDP RX-queue setup */
9880 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9881 		if (err < 0)
9882 			goto err_rxq_info;
9883 	}
9884 	return 0;
9885 
9886 err_rxq_info:
9887 	/* Rollback successful reg's and free other resources */
9888 	while (i--)
9889 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9890 	kvfree(dev->_rx);
9891 	dev->_rx = NULL;
9892 	return err;
9893 }
9894 
9895 static void netif_free_rx_queues(struct net_device *dev)
9896 {
9897 	unsigned int i, count = dev->num_rx_queues;
9898 
9899 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9900 	if (!dev->_rx)
9901 		return;
9902 
9903 	for (i = 0; i < count; i++)
9904 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9905 
9906 	kvfree(dev->_rx);
9907 }
9908 
9909 static void netdev_init_one_queue(struct net_device *dev,
9910 				  struct netdev_queue *queue, void *_unused)
9911 {
9912 	/* Initialize queue lock */
9913 	spin_lock_init(&queue->_xmit_lock);
9914 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9915 	queue->xmit_lock_owner = -1;
9916 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9917 	queue->dev = dev;
9918 #ifdef CONFIG_BQL
9919 	dql_init(&queue->dql, HZ);
9920 #endif
9921 }
9922 
9923 static void netif_free_tx_queues(struct net_device *dev)
9924 {
9925 	kvfree(dev->_tx);
9926 }
9927 
9928 static int netif_alloc_netdev_queues(struct net_device *dev)
9929 {
9930 	unsigned int count = dev->num_tx_queues;
9931 	struct netdev_queue *tx;
9932 	size_t sz = count * sizeof(*tx);
9933 
9934 	if (count < 1 || count > 0xffff)
9935 		return -EINVAL;
9936 
9937 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9938 	if (!tx)
9939 		return -ENOMEM;
9940 
9941 	dev->_tx = tx;
9942 
9943 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9944 	spin_lock_init(&dev->tx_global_lock);
9945 
9946 	return 0;
9947 }
9948 
9949 void netif_tx_stop_all_queues(struct net_device *dev)
9950 {
9951 	unsigned int i;
9952 
9953 	for (i = 0; i < dev->num_tx_queues; i++) {
9954 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9955 
9956 		netif_tx_stop_queue(txq);
9957 	}
9958 }
9959 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9960 
9961 /**
9962  * register_netdevice() - register a network device
9963  * @dev: device to register
9964  *
9965  * Take a prepared network device structure and make it externally accessible.
9966  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9967  * Callers must hold the rtnl lock - you may want register_netdev()
9968  * instead of this.
9969  */
9970 int register_netdevice(struct net_device *dev)
9971 {
9972 	int ret;
9973 	struct net *net = dev_net(dev);
9974 
9975 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9976 		     NETDEV_FEATURE_COUNT);
9977 	BUG_ON(dev_boot_phase);
9978 	ASSERT_RTNL();
9979 
9980 	might_sleep();
9981 
9982 	/* When net_device's are persistent, this will be fatal. */
9983 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9984 	BUG_ON(!net);
9985 
9986 	ret = ethtool_check_ops(dev->ethtool_ops);
9987 	if (ret)
9988 		return ret;
9989 
9990 	spin_lock_init(&dev->addr_list_lock);
9991 	netdev_set_addr_lockdep_class(dev);
9992 
9993 	ret = dev_get_valid_name(net, dev, dev->name);
9994 	if (ret < 0)
9995 		goto out;
9996 
9997 	ret = -ENOMEM;
9998 	dev->name_node = netdev_name_node_head_alloc(dev);
9999 	if (!dev->name_node)
10000 		goto out;
10001 
10002 	/* Init, if this function is available */
10003 	if (dev->netdev_ops->ndo_init) {
10004 		ret = dev->netdev_ops->ndo_init(dev);
10005 		if (ret) {
10006 			if (ret > 0)
10007 				ret = -EIO;
10008 			goto err_free_name;
10009 		}
10010 	}
10011 
10012 	if (((dev->hw_features | dev->features) &
10013 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10014 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10015 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10016 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10017 		ret = -EINVAL;
10018 		goto err_uninit;
10019 	}
10020 
10021 	ret = -EBUSY;
10022 	if (!dev->ifindex)
10023 		dev->ifindex = dev_new_index(net);
10024 	else if (__dev_get_by_index(net, dev->ifindex))
10025 		goto err_uninit;
10026 
10027 	/* Transfer changeable features to wanted_features and enable
10028 	 * software offloads (GSO and GRO).
10029 	 */
10030 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10031 	dev->features |= NETIF_F_SOFT_FEATURES;
10032 
10033 	if (dev->udp_tunnel_nic_info) {
10034 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10035 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10036 	}
10037 
10038 	dev->wanted_features = dev->features & dev->hw_features;
10039 
10040 	if (!(dev->flags & IFF_LOOPBACK))
10041 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10042 
10043 	/* If IPv4 TCP segmentation offload is supported we should also
10044 	 * allow the device to enable segmenting the frame with the option
10045 	 * of ignoring a static IP ID value.  This doesn't enable the
10046 	 * feature itself but allows the user to enable it later.
10047 	 */
10048 	if (dev->hw_features & NETIF_F_TSO)
10049 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10050 	if (dev->vlan_features & NETIF_F_TSO)
10051 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10052 	if (dev->mpls_features & NETIF_F_TSO)
10053 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10054 	if (dev->hw_enc_features & NETIF_F_TSO)
10055 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10056 
10057 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10058 	 */
10059 	dev->vlan_features |= NETIF_F_HIGHDMA;
10060 
10061 	/* Make NETIF_F_SG inheritable to tunnel devices.
10062 	 */
10063 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10064 
10065 	/* Make NETIF_F_SG inheritable to MPLS.
10066 	 */
10067 	dev->mpls_features |= NETIF_F_SG;
10068 
10069 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10070 	ret = notifier_to_errno(ret);
10071 	if (ret)
10072 		goto err_uninit;
10073 
10074 	ret = netdev_register_kobject(dev);
10075 	write_lock(&dev_base_lock);
10076 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10077 	write_unlock(&dev_base_lock);
10078 	if (ret)
10079 		goto err_uninit_notify;
10080 
10081 	__netdev_update_features(dev);
10082 
10083 	/*
10084 	 *	Default initial state at registry is that the
10085 	 *	device is present.
10086 	 */
10087 
10088 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10089 
10090 	linkwatch_init_dev(dev);
10091 
10092 	dev_init_scheduler(dev);
10093 
10094 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10095 	list_netdevice(dev);
10096 
10097 	add_device_randomness(dev->dev_addr, dev->addr_len);
10098 
10099 	/* If the device has permanent device address, driver should
10100 	 * set dev_addr and also addr_assign_type should be set to
10101 	 * NET_ADDR_PERM (default value).
10102 	 */
10103 	if (dev->addr_assign_type == NET_ADDR_PERM)
10104 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10105 
10106 	/* Notify protocols, that a new device appeared. */
10107 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10108 	ret = notifier_to_errno(ret);
10109 	if (ret) {
10110 		/* Expect explicit free_netdev() on failure */
10111 		dev->needs_free_netdev = false;
10112 		unregister_netdevice_queue(dev, NULL);
10113 		goto out;
10114 	}
10115 	/*
10116 	 *	Prevent userspace races by waiting until the network
10117 	 *	device is fully setup before sending notifications.
10118 	 */
10119 	if (!dev->rtnl_link_ops ||
10120 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10121 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10122 
10123 out:
10124 	return ret;
10125 
10126 err_uninit_notify:
10127 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10128 err_uninit:
10129 	if (dev->netdev_ops->ndo_uninit)
10130 		dev->netdev_ops->ndo_uninit(dev);
10131 	if (dev->priv_destructor)
10132 		dev->priv_destructor(dev);
10133 err_free_name:
10134 	netdev_name_node_free(dev->name_node);
10135 	goto out;
10136 }
10137 EXPORT_SYMBOL(register_netdevice);
10138 
10139 /**
10140  *	init_dummy_netdev	- init a dummy network device for NAPI
10141  *	@dev: device to init
10142  *
10143  *	This takes a network device structure and initialize the minimum
10144  *	amount of fields so it can be used to schedule NAPI polls without
10145  *	registering a full blown interface. This is to be used by drivers
10146  *	that need to tie several hardware interfaces to a single NAPI
10147  *	poll scheduler due to HW limitations.
10148  */
10149 int init_dummy_netdev(struct net_device *dev)
10150 {
10151 	/* Clear everything. Note we don't initialize spinlocks
10152 	 * are they aren't supposed to be taken by any of the
10153 	 * NAPI code and this dummy netdev is supposed to be
10154 	 * only ever used for NAPI polls
10155 	 */
10156 	memset(dev, 0, sizeof(struct net_device));
10157 
10158 	/* make sure we BUG if trying to hit standard
10159 	 * register/unregister code path
10160 	 */
10161 	dev->reg_state = NETREG_DUMMY;
10162 
10163 	/* NAPI wants this */
10164 	INIT_LIST_HEAD(&dev->napi_list);
10165 
10166 	/* a dummy interface is started by default */
10167 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10168 	set_bit(__LINK_STATE_START, &dev->state);
10169 
10170 	/* napi_busy_loop stats accounting wants this */
10171 	dev_net_set(dev, &init_net);
10172 
10173 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10174 	 * because users of this 'device' dont need to change
10175 	 * its refcount.
10176 	 */
10177 
10178 	return 0;
10179 }
10180 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10181 
10182 
10183 /**
10184  *	register_netdev	- register a network device
10185  *	@dev: device to register
10186  *
10187  *	Take a completed network device structure and add it to the kernel
10188  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10189  *	chain. 0 is returned on success. A negative errno code is returned
10190  *	on a failure to set up the device, or if the name is a duplicate.
10191  *
10192  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10193  *	and expands the device name if you passed a format string to
10194  *	alloc_netdev.
10195  */
10196 int register_netdev(struct net_device *dev)
10197 {
10198 	int err;
10199 
10200 	if (rtnl_lock_killable())
10201 		return -EINTR;
10202 	err = register_netdevice(dev);
10203 	rtnl_unlock();
10204 	return err;
10205 }
10206 EXPORT_SYMBOL(register_netdev);
10207 
10208 int netdev_refcnt_read(const struct net_device *dev)
10209 {
10210 #ifdef CONFIG_PCPU_DEV_REFCNT
10211 	int i, refcnt = 0;
10212 
10213 	for_each_possible_cpu(i)
10214 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10215 	return refcnt;
10216 #else
10217 	return refcount_read(&dev->dev_refcnt);
10218 #endif
10219 }
10220 EXPORT_SYMBOL(netdev_refcnt_read);
10221 
10222 int netdev_unregister_timeout_secs __read_mostly = 10;
10223 
10224 #define WAIT_REFS_MIN_MSECS 1
10225 #define WAIT_REFS_MAX_MSECS 250
10226 /**
10227  * netdev_wait_allrefs_any - wait until all references are gone.
10228  * @list: list of net_devices to wait on
10229  *
10230  * This is called when unregistering network devices.
10231  *
10232  * Any protocol or device that holds a reference should register
10233  * for netdevice notification, and cleanup and put back the
10234  * reference if they receive an UNREGISTER event.
10235  * We can get stuck here if buggy protocols don't correctly
10236  * call dev_put.
10237  */
10238 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10239 {
10240 	unsigned long rebroadcast_time, warning_time;
10241 	struct net_device *dev;
10242 	int wait = 0;
10243 
10244 	rebroadcast_time = warning_time = jiffies;
10245 
10246 	list_for_each_entry(dev, list, todo_list)
10247 		if (netdev_refcnt_read(dev) == 1)
10248 			return dev;
10249 
10250 	while (true) {
10251 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10252 			rtnl_lock();
10253 
10254 			/* Rebroadcast unregister notification */
10255 			list_for_each_entry(dev, list, todo_list)
10256 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10257 
10258 			__rtnl_unlock();
10259 			rcu_barrier();
10260 			rtnl_lock();
10261 
10262 			list_for_each_entry(dev, list, todo_list)
10263 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10264 					     &dev->state)) {
10265 					/* We must not have linkwatch events
10266 					 * pending on unregister. If this
10267 					 * happens, we simply run the queue
10268 					 * unscheduled, resulting in a noop
10269 					 * for this device.
10270 					 */
10271 					linkwatch_run_queue();
10272 					break;
10273 				}
10274 
10275 			__rtnl_unlock();
10276 
10277 			rebroadcast_time = jiffies;
10278 		}
10279 
10280 		if (!wait) {
10281 			rcu_barrier();
10282 			wait = WAIT_REFS_MIN_MSECS;
10283 		} else {
10284 			msleep(wait);
10285 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10286 		}
10287 
10288 		list_for_each_entry(dev, list, todo_list)
10289 			if (netdev_refcnt_read(dev) == 1)
10290 				return dev;
10291 
10292 		if (time_after(jiffies, warning_time +
10293 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10294 			list_for_each_entry(dev, list, todo_list) {
10295 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10296 					 dev->name, netdev_refcnt_read(dev));
10297 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10298 			}
10299 
10300 			warning_time = jiffies;
10301 		}
10302 	}
10303 }
10304 
10305 /* The sequence is:
10306  *
10307  *	rtnl_lock();
10308  *	...
10309  *	register_netdevice(x1);
10310  *	register_netdevice(x2);
10311  *	...
10312  *	unregister_netdevice(y1);
10313  *	unregister_netdevice(y2);
10314  *      ...
10315  *	rtnl_unlock();
10316  *	free_netdev(y1);
10317  *	free_netdev(y2);
10318  *
10319  * We are invoked by rtnl_unlock().
10320  * This allows us to deal with problems:
10321  * 1) We can delete sysfs objects which invoke hotplug
10322  *    without deadlocking with linkwatch via keventd.
10323  * 2) Since we run with the RTNL semaphore not held, we can sleep
10324  *    safely in order to wait for the netdev refcnt to drop to zero.
10325  *
10326  * We must not return until all unregister events added during
10327  * the interval the lock was held have been completed.
10328  */
10329 void netdev_run_todo(void)
10330 {
10331 	struct net_device *dev, *tmp;
10332 	struct list_head list;
10333 #ifdef CONFIG_LOCKDEP
10334 	struct list_head unlink_list;
10335 
10336 	list_replace_init(&net_unlink_list, &unlink_list);
10337 
10338 	while (!list_empty(&unlink_list)) {
10339 		struct net_device *dev = list_first_entry(&unlink_list,
10340 							  struct net_device,
10341 							  unlink_list);
10342 		list_del_init(&dev->unlink_list);
10343 		dev->nested_level = dev->lower_level - 1;
10344 	}
10345 #endif
10346 
10347 	/* Snapshot list, allow later requests */
10348 	list_replace_init(&net_todo_list, &list);
10349 
10350 	__rtnl_unlock();
10351 
10352 	/* Wait for rcu callbacks to finish before next phase */
10353 	if (!list_empty(&list))
10354 		rcu_barrier();
10355 
10356 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10357 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10358 			netdev_WARN(dev, "run_todo but not unregistering\n");
10359 			list_del(&dev->todo_list);
10360 			continue;
10361 		}
10362 
10363 		write_lock(&dev_base_lock);
10364 		dev->reg_state = NETREG_UNREGISTERED;
10365 		write_unlock(&dev_base_lock);
10366 		linkwatch_forget_dev(dev);
10367 	}
10368 
10369 	while (!list_empty(&list)) {
10370 		dev = netdev_wait_allrefs_any(&list);
10371 		list_del(&dev->todo_list);
10372 
10373 		/* paranoia */
10374 		BUG_ON(netdev_refcnt_read(dev) != 1);
10375 		BUG_ON(!list_empty(&dev->ptype_all));
10376 		BUG_ON(!list_empty(&dev->ptype_specific));
10377 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10378 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10379 
10380 		if (dev->priv_destructor)
10381 			dev->priv_destructor(dev);
10382 		if (dev->needs_free_netdev)
10383 			free_netdev(dev);
10384 
10385 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10386 			wake_up(&netdev_unregistering_wq);
10387 
10388 		/* Free network device */
10389 		kobject_put(&dev->dev.kobj);
10390 	}
10391 }
10392 
10393 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10394  * all the same fields in the same order as net_device_stats, with only
10395  * the type differing, but rtnl_link_stats64 may have additional fields
10396  * at the end for newer counters.
10397  */
10398 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10399 			     const struct net_device_stats *netdev_stats)
10400 {
10401 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10402 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10403 	u64 *dst = (u64 *)stats64;
10404 
10405 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10406 	for (i = 0; i < n; i++)
10407 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10408 	/* zero out counters that only exist in rtnl_link_stats64 */
10409 	memset((char *)stats64 + n * sizeof(u64), 0,
10410 	       sizeof(*stats64) - n * sizeof(u64));
10411 }
10412 EXPORT_SYMBOL(netdev_stats_to_stats64);
10413 
10414 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10415 {
10416 	struct net_device_core_stats __percpu *p;
10417 
10418 	p = alloc_percpu_gfp(struct net_device_core_stats,
10419 			     GFP_ATOMIC | __GFP_NOWARN);
10420 
10421 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10422 		free_percpu(p);
10423 
10424 	/* This READ_ONCE() pairs with the cmpxchg() above */
10425 	return READ_ONCE(dev->core_stats);
10426 }
10427 EXPORT_SYMBOL(netdev_core_stats_alloc);
10428 
10429 /**
10430  *	dev_get_stats	- get network device statistics
10431  *	@dev: device to get statistics from
10432  *	@storage: place to store stats
10433  *
10434  *	Get network statistics from device. Return @storage.
10435  *	The device driver may provide its own method by setting
10436  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10437  *	otherwise the internal statistics structure is used.
10438  */
10439 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10440 					struct rtnl_link_stats64 *storage)
10441 {
10442 	const struct net_device_ops *ops = dev->netdev_ops;
10443 	const struct net_device_core_stats __percpu *p;
10444 
10445 	if (ops->ndo_get_stats64) {
10446 		memset(storage, 0, sizeof(*storage));
10447 		ops->ndo_get_stats64(dev, storage);
10448 	} else if (ops->ndo_get_stats) {
10449 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10450 	} else {
10451 		netdev_stats_to_stats64(storage, &dev->stats);
10452 	}
10453 
10454 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10455 	p = READ_ONCE(dev->core_stats);
10456 	if (p) {
10457 		const struct net_device_core_stats *core_stats;
10458 		int i;
10459 
10460 		for_each_possible_cpu(i) {
10461 			core_stats = per_cpu_ptr(p, i);
10462 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10463 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10464 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10465 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10466 		}
10467 	}
10468 	return storage;
10469 }
10470 EXPORT_SYMBOL(dev_get_stats);
10471 
10472 /**
10473  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10474  *	@s: place to store stats
10475  *	@netstats: per-cpu network stats to read from
10476  *
10477  *	Read per-cpu network statistics and populate the related fields in @s.
10478  */
10479 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10480 			   const struct pcpu_sw_netstats __percpu *netstats)
10481 {
10482 	int cpu;
10483 
10484 	for_each_possible_cpu(cpu) {
10485 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10486 		const struct pcpu_sw_netstats *stats;
10487 		unsigned int start;
10488 
10489 		stats = per_cpu_ptr(netstats, cpu);
10490 		do {
10491 			start = u64_stats_fetch_begin(&stats->syncp);
10492 			rx_packets = u64_stats_read(&stats->rx_packets);
10493 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10494 			tx_packets = u64_stats_read(&stats->tx_packets);
10495 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10496 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10497 
10498 		s->rx_packets += rx_packets;
10499 		s->rx_bytes   += rx_bytes;
10500 		s->tx_packets += tx_packets;
10501 		s->tx_bytes   += tx_bytes;
10502 	}
10503 }
10504 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10505 
10506 /**
10507  *	dev_get_tstats64 - ndo_get_stats64 implementation
10508  *	@dev: device to get statistics from
10509  *	@s: place to store stats
10510  *
10511  *	Populate @s from dev->stats and dev->tstats. Can be used as
10512  *	ndo_get_stats64() callback.
10513  */
10514 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10515 {
10516 	netdev_stats_to_stats64(s, &dev->stats);
10517 	dev_fetch_sw_netstats(s, dev->tstats);
10518 }
10519 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10520 
10521 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10522 {
10523 	struct netdev_queue *queue = dev_ingress_queue(dev);
10524 
10525 #ifdef CONFIG_NET_CLS_ACT
10526 	if (queue)
10527 		return queue;
10528 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10529 	if (!queue)
10530 		return NULL;
10531 	netdev_init_one_queue(dev, queue, NULL);
10532 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10533 	queue->qdisc_sleeping = &noop_qdisc;
10534 	rcu_assign_pointer(dev->ingress_queue, queue);
10535 #endif
10536 	return queue;
10537 }
10538 
10539 static const struct ethtool_ops default_ethtool_ops;
10540 
10541 void netdev_set_default_ethtool_ops(struct net_device *dev,
10542 				    const struct ethtool_ops *ops)
10543 {
10544 	if (dev->ethtool_ops == &default_ethtool_ops)
10545 		dev->ethtool_ops = ops;
10546 }
10547 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10548 
10549 /**
10550  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10551  * @dev: netdev to enable the IRQ coalescing on
10552  *
10553  * Sets a conservative default for SW IRQ coalescing. Users can use
10554  * sysfs attributes to override the default values.
10555  */
10556 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10557 {
10558 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10559 
10560 	dev->gro_flush_timeout = 20000;
10561 	dev->napi_defer_hard_irqs = 1;
10562 }
10563 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10564 
10565 void netdev_freemem(struct net_device *dev)
10566 {
10567 	char *addr = (char *)dev - dev->padded;
10568 
10569 	kvfree(addr);
10570 }
10571 
10572 /**
10573  * alloc_netdev_mqs - allocate network device
10574  * @sizeof_priv: size of private data to allocate space for
10575  * @name: device name format string
10576  * @name_assign_type: origin of device name
10577  * @setup: callback to initialize device
10578  * @txqs: the number of TX subqueues to allocate
10579  * @rxqs: the number of RX subqueues to allocate
10580  *
10581  * Allocates a struct net_device with private data area for driver use
10582  * and performs basic initialization.  Also allocates subqueue structs
10583  * for each queue on the device.
10584  */
10585 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10586 		unsigned char name_assign_type,
10587 		void (*setup)(struct net_device *),
10588 		unsigned int txqs, unsigned int rxqs)
10589 {
10590 	struct net_device *dev;
10591 	unsigned int alloc_size;
10592 	struct net_device *p;
10593 
10594 	BUG_ON(strlen(name) >= sizeof(dev->name));
10595 
10596 	if (txqs < 1) {
10597 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10598 		return NULL;
10599 	}
10600 
10601 	if (rxqs < 1) {
10602 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10603 		return NULL;
10604 	}
10605 
10606 	alloc_size = sizeof(struct net_device);
10607 	if (sizeof_priv) {
10608 		/* ensure 32-byte alignment of private area */
10609 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10610 		alloc_size += sizeof_priv;
10611 	}
10612 	/* ensure 32-byte alignment of whole construct */
10613 	alloc_size += NETDEV_ALIGN - 1;
10614 
10615 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10616 	if (!p)
10617 		return NULL;
10618 
10619 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10620 	dev->padded = (char *)dev - (char *)p;
10621 
10622 	ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10623 #ifdef CONFIG_PCPU_DEV_REFCNT
10624 	dev->pcpu_refcnt = alloc_percpu(int);
10625 	if (!dev->pcpu_refcnt)
10626 		goto free_dev;
10627 	__dev_hold(dev);
10628 #else
10629 	refcount_set(&dev->dev_refcnt, 1);
10630 #endif
10631 
10632 	if (dev_addr_init(dev))
10633 		goto free_pcpu;
10634 
10635 	dev_mc_init(dev);
10636 	dev_uc_init(dev);
10637 
10638 	dev_net_set(dev, &init_net);
10639 
10640 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10641 	dev->gso_max_segs = GSO_MAX_SEGS;
10642 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10643 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10644 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10645 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10646 	dev->tso_max_segs = TSO_MAX_SEGS;
10647 	dev->upper_level = 1;
10648 	dev->lower_level = 1;
10649 #ifdef CONFIG_LOCKDEP
10650 	dev->nested_level = 0;
10651 	INIT_LIST_HEAD(&dev->unlink_list);
10652 #endif
10653 
10654 	INIT_LIST_HEAD(&dev->napi_list);
10655 	INIT_LIST_HEAD(&dev->unreg_list);
10656 	INIT_LIST_HEAD(&dev->close_list);
10657 	INIT_LIST_HEAD(&dev->link_watch_list);
10658 	INIT_LIST_HEAD(&dev->adj_list.upper);
10659 	INIT_LIST_HEAD(&dev->adj_list.lower);
10660 	INIT_LIST_HEAD(&dev->ptype_all);
10661 	INIT_LIST_HEAD(&dev->ptype_specific);
10662 	INIT_LIST_HEAD(&dev->net_notifier_list);
10663 #ifdef CONFIG_NET_SCHED
10664 	hash_init(dev->qdisc_hash);
10665 #endif
10666 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10667 	setup(dev);
10668 
10669 	if (!dev->tx_queue_len) {
10670 		dev->priv_flags |= IFF_NO_QUEUE;
10671 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10672 	}
10673 
10674 	dev->num_tx_queues = txqs;
10675 	dev->real_num_tx_queues = txqs;
10676 	if (netif_alloc_netdev_queues(dev))
10677 		goto free_all;
10678 
10679 	dev->num_rx_queues = rxqs;
10680 	dev->real_num_rx_queues = rxqs;
10681 	if (netif_alloc_rx_queues(dev))
10682 		goto free_all;
10683 
10684 	strcpy(dev->name, name);
10685 	dev->name_assign_type = name_assign_type;
10686 	dev->group = INIT_NETDEV_GROUP;
10687 	if (!dev->ethtool_ops)
10688 		dev->ethtool_ops = &default_ethtool_ops;
10689 
10690 	nf_hook_netdev_init(dev);
10691 
10692 	return dev;
10693 
10694 free_all:
10695 	free_netdev(dev);
10696 	return NULL;
10697 
10698 free_pcpu:
10699 #ifdef CONFIG_PCPU_DEV_REFCNT
10700 	free_percpu(dev->pcpu_refcnt);
10701 free_dev:
10702 #endif
10703 	netdev_freemem(dev);
10704 	return NULL;
10705 }
10706 EXPORT_SYMBOL(alloc_netdev_mqs);
10707 
10708 /**
10709  * free_netdev - free network device
10710  * @dev: device
10711  *
10712  * This function does the last stage of destroying an allocated device
10713  * interface. The reference to the device object is released. If this
10714  * is the last reference then it will be freed.Must be called in process
10715  * context.
10716  */
10717 void free_netdev(struct net_device *dev)
10718 {
10719 	struct napi_struct *p, *n;
10720 
10721 	might_sleep();
10722 
10723 	/* When called immediately after register_netdevice() failed the unwind
10724 	 * handling may still be dismantling the device. Handle that case by
10725 	 * deferring the free.
10726 	 */
10727 	if (dev->reg_state == NETREG_UNREGISTERING) {
10728 		ASSERT_RTNL();
10729 		dev->needs_free_netdev = true;
10730 		return;
10731 	}
10732 
10733 	netif_free_tx_queues(dev);
10734 	netif_free_rx_queues(dev);
10735 
10736 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10737 
10738 	/* Flush device addresses */
10739 	dev_addr_flush(dev);
10740 
10741 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10742 		netif_napi_del(p);
10743 
10744 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10745 #ifdef CONFIG_PCPU_DEV_REFCNT
10746 	free_percpu(dev->pcpu_refcnt);
10747 	dev->pcpu_refcnt = NULL;
10748 #endif
10749 	free_percpu(dev->core_stats);
10750 	dev->core_stats = NULL;
10751 	free_percpu(dev->xdp_bulkq);
10752 	dev->xdp_bulkq = NULL;
10753 
10754 	/*  Compatibility with error handling in drivers */
10755 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10756 		netdev_freemem(dev);
10757 		return;
10758 	}
10759 
10760 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10761 	dev->reg_state = NETREG_RELEASED;
10762 
10763 	/* will free via device release */
10764 	put_device(&dev->dev);
10765 }
10766 EXPORT_SYMBOL(free_netdev);
10767 
10768 /**
10769  *	synchronize_net -  Synchronize with packet receive processing
10770  *
10771  *	Wait for packets currently being received to be done.
10772  *	Does not block later packets from starting.
10773  */
10774 void synchronize_net(void)
10775 {
10776 	might_sleep();
10777 	if (rtnl_is_locked())
10778 		synchronize_rcu_expedited();
10779 	else
10780 		synchronize_rcu();
10781 }
10782 EXPORT_SYMBOL(synchronize_net);
10783 
10784 /**
10785  *	unregister_netdevice_queue - remove device from the kernel
10786  *	@dev: device
10787  *	@head: list
10788  *
10789  *	This function shuts down a device interface and removes it
10790  *	from the kernel tables.
10791  *	If head not NULL, device is queued to be unregistered later.
10792  *
10793  *	Callers must hold the rtnl semaphore.  You may want
10794  *	unregister_netdev() instead of this.
10795  */
10796 
10797 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10798 {
10799 	ASSERT_RTNL();
10800 
10801 	if (head) {
10802 		list_move_tail(&dev->unreg_list, head);
10803 	} else {
10804 		LIST_HEAD(single);
10805 
10806 		list_add(&dev->unreg_list, &single);
10807 		unregister_netdevice_many(&single);
10808 	}
10809 }
10810 EXPORT_SYMBOL(unregister_netdevice_queue);
10811 
10812 void unregister_netdevice_many_notify(struct list_head *head,
10813 				      u32 portid, const struct nlmsghdr *nlh)
10814 {
10815 	struct net_device *dev, *tmp;
10816 	LIST_HEAD(close_head);
10817 
10818 	BUG_ON(dev_boot_phase);
10819 	ASSERT_RTNL();
10820 
10821 	if (list_empty(head))
10822 		return;
10823 
10824 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10825 		/* Some devices call without registering
10826 		 * for initialization unwind. Remove those
10827 		 * devices and proceed with the remaining.
10828 		 */
10829 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10830 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10831 				 dev->name, dev);
10832 
10833 			WARN_ON(1);
10834 			list_del(&dev->unreg_list);
10835 			continue;
10836 		}
10837 		dev->dismantle = true;
10838 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10839 	}
10840 
10841 	/* If device is running, close it first. */
10842 	list_for_each_entry(dev, head, unreg_list)
10843 		list_add_tail(&dev->close_list, &close_head);
10844 	dev_close_many(&close_head, true);
10845 
10846 	list_for_each_entry(dev, head, unreg_list) {
10847 		/* And unlink it from device chain. */
10848 		write_lock(&dev_base_lock);
10849 		unlist_netdevice(dev, false);
10850 		dev->reg_state = NETREG_UNREGISTERING;
10851 		write_unlock(&dev_base_lock);
10852 	}
10853 	flush_all_backlogs();
10854 
10855 	synchronize_net();
10856 
10857 	list_for_each_entry(dev, head, unreg_list) {
10858 		struct sk_buff *skb = NULL;
10859 
10860 		/* Shutdown queueing discipline. */
10861 		dev_shutdown(dev);
10862 
10863 		dev_xdp_uninstall(dev);
10864 		bpf_dev_bound_netdev_unregister(dev);
10865 
10866 		netdev_offload_xstats_disable_all(dev);
10867 
10868 		/* Notify protocols, that we are about to destroy
10869 		 * this device. They should clean all the things.
10870 		 */
10871 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10872 
10873 		if (!dev->rtnl_link_ops ||
10874 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10875 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10876 						     GFP_KERNEL, NULL, 0,
10877 						     portid, nlh);
10878 
10879 		/*
10880 		 *	Flush the unicast and multicast chains
10881 		 */
10882 		dev_uc_flush(dev);
10883 		dev_mc_flush(dev);
10884 
10885 		netdev_name_node_alt_flush(dev);
10886 		netdev_name_node_free(dev->name_node);
10887 
10888 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10889 
10890 		if (dev->netdev_ops->ndo_uninit)
10891 			dev->netdev_ops->ndo_uninit(dev);
10892 
10893 		if (skb)
10894 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
10895 
10896 		/* Notifier chain MUST detach us all upper devices. */
10897 		WARN_ON(netdev_has_any_upper_dev(dev));
10898 		WARN_ON(netdev_has_any_lower_dev(dev));
10899 
10900 		/* Remove entries from kobject tree */
10901 		netdev_unregister_kobject(dev);
10902 #ifdef CONFIG_XPS
10903 		/* Remove XPS queueing entries */
10904 		netif_reset_xps_queues_gt(dev, 0);
10905 #endif
10906 	}
10907 
10908 	synchronize_net();
10909 
10910 	list_for_each_entry(dev, head, unreg_list) {
10911 		netdev_put(dev, &dev->dev_registered_tracker);
10912 		net_set_todo(dev);
10913 	}
10914 
10915 	list_del(head);
10916 }
10917 
10918 /**
10919  *	unregister_netdevice_many - unregister many devices
10920  *	@head: list of devices
10921  *
10922  *  Note: As most callers use a stack allocated list_head,
10923  *  we force a list_del() to make sure stack wont be corrupted later.
10924  */
10925 void unregister_netdevice_many(struct list_head *head)
10926 {
10927 	unregister_netdevice_many_notify(head, 0, NULL);
10928 }
10929 EXPORT_SYMBOL(unregister_netdevice_many);
10930 
10931 /**
10932  *	unregister_netdev - remove device from the kernel
10933  *	@dev: device
10934  *
10935  *	This function shuts down a device interface and removes it
10936  *	from the kernel tables.
10937  *
10938  *	This is just a wrapper for unregister_netdevice that takes
10939  *	the rtnl semaphore.  In general you want to use this and not
10940  *	unregister_netdevice.
10941  */
10942 void unregister_netdev(struct net_device *dev)
10943 {
10944 	rtnl_lock();
10945 	unregister_netdevice(dev);
10946 	rtnl_unlock();
10947 }
10948 EXPORT_SYMBOL(unregister_netdev);
10949 
10950 /**
10951  *	__dev_change_net_namespace - move device to different nethost namespace
10952  *	@dev: device
10953  *	@net: network namespace
10954  *	@pat: If not NULL name pattern to try if the current device name
10955  *	      is already taken in the destination network namespace.
10956  *	@new_ifindex: If not zero, specifies device index in the target
10957  *	              namespace.
10958  *
10959  *	This function shuts down a device interface and moves it
10960  *	to a new network namespace. On success 0 is returned, on
10961  *	a failure a netagive errno code is returned.
10962  *
10963  *	Callers must hold the rtnl semaphore.
10964  */
10965 
10966 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10967 			       const char *pat, int new_ifindex)
10968 {
10969 	struct net *net_old = dev_net(dev);
10970 	int err, new_nsid;
10971 
10972 	ASSERT_RTNL();
10973 
10974 	/* Don't allow namespace local devices to be moved. */
10975 	err = -EINVAL;
10976 	if (dev->features & NETIF_F_NETNS_LOCAL)
10977 		goto out;
10978 
10979 	/* Ensure the device has been registrered */
10980 	if (dev->reg_state != NETREG_REGISTERED)
10981 		goto out;
10982 
10983 	/* Get out if there is nothing todo */
10984 	err = 0;
10985 	if (net_eq(net_old, net))
10986 		goto out;
10987 
10988 	/* Pick the destination device name, and ensure
10989 	 * we can use it in the destination network namespace.
10990 	 */
10991 	err = -EEXIST;
10992 	if (netdev_name_in_use(net, dev->name)) {
10993 		/* We get here if we can't use the current device name */
10994 		if (!pat)
10995 			goto out;
10996 		err = dev_get_valid_name(net, dev, pat);
10997 		if (err < 0)
10998 			goto out;
10999 	}
11000 
11001 	/* Check that new_ifindex isn't used yet. */
11002 	err = -EBUSY;
11003 	if (new_ifindex && __dev_get_by_index(net, new_ifindex))
11004 		goto out;
11005 
11006 	/*
11007 	 * And now a mini version of register_netdevice unregister_netdevice.
11008 	 */
11009 
11010 	/* If device is running close it first. */
11011 	dev_close(dev);
11012 
11013 	/* And unlink it from device chain */
11014 	unlist_netdevice(dev, true);
11015 
11016 	synchronize_net();
11017 
11018 	/* Shutdown queueing discipline. */
11019 	dev_shutdown(dev);
11020 
11021 	/* Notify protocols, that we are about to destroy
11022 	 * this device. They should clean all the things.
11023 	 *
11024 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11025 	 * This is wanted because this way 8021q and macvlan know
11026 	 * the device is just moving and can keep their slaves up.
11027 	 */
11028 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11029 	rcu_barrier();
11030 
11031 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11032 	/* If there is an ifindex conflict assign a new one */
11033 	if (!new_ifindex) {
11034 		if (__dev_get_by_index(net, dev->ifindex))
11035 			new_ifindex = dev_new_index(net);
11036 		else
11037 			new_ifindex = dev->ifindex;
11038 	}
11039 
11040 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11041 			    new_ifindex);
11042 
11043 	/*
11044 	 *	Flush the unicast and multicast chains
11045 	 */
11046 	dev_uc_flush(dev);
11047 	dev_mc_flush(dev);
11048 
11049 	/* Send a netdev-removed uevent to the old namespace */
11050 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11051 	netdev_adjacent_del_links(dev);
11052 
11053 	/* Move per-net netdevice notifiers that are following the netdevice */
11054 	move_netdevice_notifiers_dev_net(dev, net);
11055 
11056 	/* Actually switch the network namespace */
11057 	dev_net_set(dev, net);
11058 	dev->ifindex = new_ifindex;
11059 
11060 	/* Send a netdev-add uevent to the new namespace */
11061 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11062 	netdev_adjacent_add_links(dev);
11063 
11064 	/* Fixup kobjects */
11065 	err = device_rename(&dev->dev, dev->name);
11066 	WARN_ON(err);
11067 
11068 	/* Adapt owner in case owning user namespace of target network
11069 	 * namespace is different from the original one.
11070 	 */
11071 	err = netdev_change_owner(dev, net_old, net);
11072 	WARN_ON(err);
11073 
11074 	/* Add the device back in the hashes */
11075 	list_netdevice(dev);
11076 
11077 	/* Notify protocols, that a new device appeared. */
11078 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11079 
11080 	/*
11081 	 *	Prevent userspace races by waiting until the network
11082 	 *	device is fully setup before sending notifications.
11083 	 */
11084 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11085 
11086 	synchronize_net();
11087 	err = 0;
11088 out:
11089 	return err;
11090 }
11091 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11092 
11093 static int dev_cpu_dead(unsigned int oldcpu)
11094 {
11095 	struct sk_buff **list_skb;
11096 	struct sk_buff *skb;
11097 	unsigned int cpu;
11098 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11099 
11100 	local_irq_disable();
11101 	cpu = smp_processor_id();
11102 	sd = &per_cpu(softnet_data, cpu);
11103 	oldsd = &per_cpu(softnet_data, oldcpu);
11104 
11105 	/* Find end of our completion_queue. */
11106 	list_skb = &sd->completion_queue;
11107 	while (*list_skb)
11108 		list_skb = &(*list_skb)->next;
11109 	/* Append completion queue from offline CPU. */
11110 	*list_skb = oldsd->completion_queue;
11111 	oldsd->completion_queue = NULL;
11112 
11113 	/* Append output queue from offline CPU. */
11114 	if (oldsd->output_queue) {
11115 		*sd->output_queue_tailp = oldsd->output_queue;
11116 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11117 		oldsd->output_queue = NULL;
11118 		oldsd->output_queue_tailp = &oldsd->output_queue;
11119 	}
11120 	/* Append NAPI poll list from offline CPU, with one exception :
11121 	 * process_backlog() must be called by cpu owning percpu backlog.
11122 	 * We properly handle process_queue & input_pkt_queue later.
11123 	 */
11124 	while (!list_empty(&oldsd->poll_list)) {
11125 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11126 							    struct napi_struct,
11127 							    poll_list);
11128 
11129 		list_del_init(&napi->poll_list);
11130 		if (napi->poll == process_backlog)
11131 			napi->state = 0;
11132 		else
11133 			____napi_schedule(sd, napi);
11134 	}
11135 
11136 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11137 	local_irq_enable();
11138 
11139 #ifdef CONFIG_RPS
11140 	remsd = oldsd->rps_ipi_list;
11141 	oldsd->rps_ipi_list = NULL;
11142 #endif
11143 	/* send out pending IPI's on offline CPU */
11144 	net_rps_send_ipi(remsd);
11145 
11146 	/* Process offline CPU's input_pkt_queue */
11147 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11148 		netif_rx(skb);
11149 		input_queue_head_incr(oldsd);
11150 	}
11151 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11152 		netif_rx(skb);
11153 		input_queue_head_incr(oldsd);
11154 	}
11155 
11156 	return 0;
11157 }
11158 
11159 /**
11160  *	netdev_increment_features - increment feature set by one
11161  *	@all: current feature set
11162  *	@one: new feature set
11163  *	@mask: mask feature set
11164  *
11165  *	Computes a new feature set after adding a device with feature set
11166  *	@one to the master device with current feature set @all.  Will not
11167  *	enable anything that is off in @mask. Returns the new feature set.
11168  */
11169 netdev_features_t netdev_increment_features(netdev_features_t all,
11170 	netdev_features_t one, netdev_features_t mask)
11171 {
11172 	if (mask & NETIF_F_HW_CSUM)
11173 		mask |= NETIF_F_CSUM_MASK;
11174 	mask |= NETIF_F_VLAN_CHALLENGED;
11175 
11176 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11177 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11178 
11179 	/* If one device supports hw checksumming, set for all. */
11180 	if (all & NETIF_F_HW_CSUM)
11181 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11182 
11183 	return all;
11184 }
11185 EXPORT_SYMBOL(netdev_increment_features);
11186 
11187 static struct hlist_head * __net_init netdev_create_hash(void)
11188 {
11189 	int i;
11190 	struct hlist_head *hash;
11191 
11192 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11193 	if (hash != NULL)
11194 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11195 			INIT_HLIST_HEAD(&hash[i]);
11196 
11197 	return hash;
11198 }
11199 
11200 /* Initialize per network namespace state */
11201 static int __net_init netdev_init(struct net *net)
11202 {
11203 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11204 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11205 
11206 	INIT_LIST_HEAD(&net->dev_base_head);
11207 
11208 	net->dev_name_head = netdev_create_hash();
11209 	if (net->dev_name_head == NULL)
11210 		goto err_name;
11211 
11212 	net->dev_index_head = netdev_create_hash();
11213 	if (net->dev_index_head == NULL)
11214 		goto err_idx;
11215 
11216 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11217 
11218 	return 0;
11219 
11220 err_idx:
11221 	kfree(net->dev_name_head);
11222 err_name:
11223 	return -ENOMEM;
11224 }
11225 
11226 /**
11227  *	netdev_drivername - network driver for the device
11228  *	@dev: network device
11229  *
11230  *	Determine network driver for device.
11231  */
11232 const char *netdev_drivername(const struct net_device *dev)
11233 {
11234 	const struct device_driver *driver;
11235 	const struct device *parent;
11236 	const char *empty = "";
11237 
11238 	parent = dev->dev.parent;
11239 	if (!parent)
11240 		return empty;
11241 
11242 	driver = parent->driver;
11243 	if (driver && driver->name)
11244 		return driver->name;
11245 	return empty;
11246 }
11247 
11248 static void __netdev_printk(const char *level, const struct net_device *dev,
11249 			    struct va_format *vaf)
11250 {
11251 	if (dev && dev->dev.parent) {
11252 		dev_printk_emit(level[1] - '0',
11253 				dev->dev.parent,
11254 				"%s %s %s%s: %pV",
11255 				dev_driver_string(dev->dev.parent),
11256 				dev_name(dev->dev.parent),
11257 				netdev_name(dev), netdev_reg_state(dev),
11258 				vaf);
11259 	} else if (dev) {
11260 		printk("%s%s%s: %pV",
11261 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11262 	} else {
11263 		printk("%s(NULL net_device): %pV", level, vaf);
11264 	}
11265 }
11266 
11267 void netdev_printk(const char *level, const struct net_device *dev,
11268 		   const char *format, ...)
11269 {
11270 	struct va_format vaf;
11271 	va_list args;
11272 
11273 	va_start(args, format);
11274 
11275 	vaf.fmt = format;
11276 	vaf.va = &args;
11277 
11278 	__netdev_printk(level, dev, &vaf);
11279 
11280 	va_end(args);
11281 }
11282 EXPORT_SYMBOL(netdev_printk);
11283 
11284 #define define_netdev_printk_level(func, level)			\
11285 void func(const struct net_device *dev, const char *fmt, ...)	\
11286 {								\
11287 	struct va_format vaf;					\
11288 	va_list args;						\
11289 								\
11290 	va_start(args, fmt);					\
11291 								\
11292 	vaf.fmt = fmt;						\
11293 	vaf.va = &args;						\
11294 								\
11295 	__netdev_printk(level, dev, &vaf);			\
11296 								\
11297 	va_end(args);						\
11298 }								\
11299 EXPORT_SYMBOL(func);
11300 
11301 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11302 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11303 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11304 define_netdev_printk_level(netdev_err, KERN_ERR);
11305 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11306 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11307 define_netdev_printk_level(netdev_info, KERN_INFO);
11308 
11309 static void __net_exit netdev_exit(struct net *net)
11310 {
11311 	kfree(net->dev_name_head);
11312 	kfree(net->dev_index_head);
11313 	if (net != &init_net)
11314 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11315 }
11316 
11317 static struct pernet_operations __net_initdata netdev_net_ops = {
11318 	.init = netdev_init,
11319 	.exit = netdev_exit,
11320 };
11321 
11322 static void __net_exit default_device_exit_net(struct net *net)
11323 {
11324 	struct net_device *dev, *aux;
11325 	/*
11326 	 * Push all migratable network devices back to the
11327 	 * initial network namespace
11328 	 */
11329 	ASSERT_RTNL();
11330 	for_each_netdev_safe(net, dev, aux) {
11331 		int err;
11332 		char fb_name[IFNAMSIZ];
11333 
11334 		/* Ignore unmoveable devices (i.e. loopback) */
11335 		if (dev->features & NETIF_F_NETNS_LOCAL)
11336 			continue;
11337 
11338 		/* Leave virtual devices for the generic cleanup */
11339 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11340 			continue;
11341 
11342 		/* Push remaining network devices to init_net */
11343 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11344 		if (netdev_name_in_use(&init_net, fb_name))
11345 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11346 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11347 		if (err) {
11348 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11349 				 __func__, dev->name, err);
11350 			BUG();
11351 		}
11352 	}
11353 }
11354 
11355 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11356 {
11357 	/* At exit all network devices most be removed from a network
11358 	 * namespace.  Do this in the reverse order of registration.
11359 	 * Do this across as many network namespaces as possible to
11360 	 * improve batching efficiency.
11361 	 */
11362 	struct net_device *dev;
11363 	struct net *net;
11364 	LIST_HEAD(dev_kill_list);
11365 
11366 	rtnl_lock();
11367 	list_for_each_entry(net, net_list, exit_list) {
11368 		default_device_exit_net(net);
11369 		cond_resched();
11370 	}
11371 
11372 	list_for_each_entry(net, net_list, exit_list) {
11373 		for_each_netdev_reverse(net, dev) {
11374 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11375 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11376 			else
11377 				unregister_netdevice_queue(dev, &dev_kill_list);
11378 		}
11379 	}
11380 	unregister_netdevice_many(&dev_kill_list);
11381 	rtnl_unlock();
11382 }
11383 
11384 static struct pernet_operations __net_initdata default_device_ops = {
11385 	.exit_batch = default_device_exit_batch,
11386 };
11387 
11388 /*
11389  *	Initialize the DEV module. At boot time this walks the device list and
11390  *	unhooks any devices that fail to initialise (normally hardware not
11391  *	present) and leaves us with a valid list of present and active devices.
11392  *
11393  */
11394 
11395 /*
11396  *       This is called single threaded during boot, so no need
11397  *       to take the rtnl semaphore.
11398  */
11399 static int __init net_dev_init(void)
11400 {
11401 	int i, rc = -ENOMEM;
11402 
11403 	BUG_ON(!dev_boot_phase);
11404 
11405 	if (dev_proc_init())
11406 		goto out;
11407 
11408 	if (netdev_kobject_init())
11409 		goto out;
11410 
11411 	INIT_LIST_HEAD(&ptype_all);
11412 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11413 		INIT_LIST_HEAD(&ptype_base[i]);
11414 
11415 	if (register_pernet_subsys(&netdev_net_ops))
11416 		goto out;
11417 
11418 	/*
11419 	 *	Initialise the packet receive queues.
11420 	 */
11421 
11422 	for_each_possible_cpu(i) {
11423 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11424 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11425 
11426 		INIT_WORK(flush, flush_backlog);
11427 
11428 		skb_queue_head_init(&sd->input_pkt_queue);
11429 		skb_queue_head_init(&sd->process_queue);
11430 #ifdef CONFIG_XFRM_OFFLOAD
11431 		skb_queue_head_init(&sd->xfrm_backlog);
11432 #endif
11433 		INIT_LIST_HEAD(&sd->poll_list);
11434 		sd->output_queue_tailp = &sd->output_queue;
11435 #ifdef CONFIG_RPS
11436 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11437 		sd->cpu = i;
11438 #endif
11439 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11440 		spin_lock_init(&sd->defer_lock);
11441 
11442 		init_gro_hash(&sd->backlog);
11443 		sd->backlog.poll = process_backlog;
11444 		sd->backlog.weight = weight_p;
11445 	}
11446 
11447 	dev_boot_phase = 0;
11448 
11449 	/* The loopback device is special if any other network devices
11450 	 * is present in a network namespace the loopback device must
11451 	 * be present. Since we now dynamically allocate and free the
11452 	 * loopback device ensure this invariant is maintained by
11453 	 * keeping the loopback device as the first device on the
11454 	 * list of network devices.  Ensuring the loopback devices
11455 	 * is the first device that appears and the last network device
11456 	 * that disappears.
11457 	 */
11458 	if (register_pernet_device(&loopback_net_ops))
11459 		goto out;
11460 
11461 	if (register_pernet_device(&default_device_ops))
11462 		goto out;
11463 
11464 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11465 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11466 
11467 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11468 				       NULL, dev_cpu_dead);
11469 	WARN_ON(rc < 0);
11470 	rc = 0;
11471 out:
11472 	return rc;
11473 }
11474 
11475 subsys_initcall(net_dev_init);
11476