xref: /linux-6.15/net/core/dev_addr_lists.c (revision 93f14468)
1 /*
2  * net/core/dev_addr_lists.c - Functions for handling net device lists
3  * Copyright (c) 2010 Jiri Pirko <[email protected]>
4  *
5  * This file contains functions for working with unicast, multicast and device
6  * addresses lists.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #include <linux/netdevice.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/export.h>
17 #include <linux/list.h>
18 
19 /*
20  * General list handling functions
21  */
22 
23 static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
24 			       const unsigned char *addr, int addr_len,
25 			       unsigned char addr_type, bool global,
26 			       bool sync)
27 {
28 	struct netdev_hw_addr *ha;
29 	int alloc_size;
30 
31 	alloc_size = sizeof(*ha);
32 	if (alloc_size < L1_CACHE_BYTES)
33 		alloc_size = L1_CACHE_BYTES;
34 	ha = kmalloc(alloc_size, GFP_ATOMIC);
35 	if (!ha)
36 		return -ENOMEM;
37 	memcpy(ha->addr, addr, addr_len);
38 	ha->type = addr_type;
39 	ha->refcount = 1;
40 	ha->global_use = global;
41 	ha->synced = sync;
42 	list_add_tail_rcu(&ha->list, &list->list);
43 	list->count++;
44 
45 	return 0;
46 }
47 
48 static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
49 			    const unsigned char *addr, int addr_len,
50 			    unsigned char addr_type, bool global, bool sync)
51 {
52 	struct netdev_hw_addr *ha;
53 
54 	if (addr_len > MAX_ADDR_LEN)
55 		return -EINVAL;
56 
57 	list_for_each_entry(ha, &list->list, list) {
58 		if (!memcmp(ha->addr, addr, addr_len) &&
59 		    ha->type == addr_type) {
60 			if (global) {
61 				/* check if addr is already used as global */
62 				if (ha->global_use)
63 					return 0;
64 				else
65 					ha->global_use = true;
66 			}
67 			if (sync) {
68 				if (ha->synced)
69 					return 0;
70 				else
71 					ha->synced = true;
72 			}
73 			ha->refcount++;
74 			return 0;
75 		}
76 	}
77 
78 	return __hw_addr_create_ex(list, addr, addr_len, addr_type, global,
79 				   sync);
80 }
81 
82 static int __hw_addr_add(struct netdev_hw_addr_list *list,
83 			 const unsigned char *addr, int addr_len,
84 			 unsigned char addr_type)
85 {
86 	return __hw_addr_add_ex(list, addr, addr_len, addr_type, false, false);
87 }
88 
89 static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
90 			       struct netdev_hw_addr *ha, bool global,
91 			       bool sync)
92 {
93 	if (global && !ha->global_use)
94 		return -ENOENT;
95 
96 	if (sync && !ha->synced)
97 		return -ENOENT;
98 
99 	if (global)
100 		ha->global_use = false;
101 
102 	if (sync)
103 		ha->synced = false;
104 
105 	if (--ha->refcount)
106 		return 0;
107 	list_del_rcu(&ha->list);
108 	kfree_rcu(ha, rcu_head);
109 	list->count--;
110 	return 0;
111 }
112 
113 static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
114 			    const unsigned char *addr, int addr_len,
115 			    unsigned char addr_type, bool global, bool sync)
116 {
117 	struct netdev_hw_addr *ha;
118 
119 	list_for_each_entry(ha, &list->list, list) {
120 		if (!memcmp(ha->addr, addr, addr_len) &&
121 		    (ha->type == addr_type || !addr_type))
122 			return __hw_addr_del_entry(list, ha, global, sync);
123 	}
124 	return -ENOENT;
125 }
126 
127 static int __hw_addr_del(struct netdev_hw_addr_list *list,
128 			 const unsigned char *addr, int addr_len,
129 			 unsigned char addr_type)
130 {
131 	return __hw_addr_del_ex(list, addr, addr_len, addr_type, false, false);
132 }
133 
134 static int __hw_addr_sync_one(struct netdev_hw_addr_list *to_list,
135 			       struct netdev_hw_addr *ha,
136 			       int addr_len)
137 {
138 	int err;
139 
140 	err = __hw_addr_add_ex(to_list, ha->addr, addr_len, ha->type,
141 			       false, true);
142 	if (err)
143 		return err;
144 	ha->sync_cnt++;
145 	ha->refcount++;
146 
147 	return 0;
148 }
149 
150 static void __hw_addr_unsync_one(struct netdev_hw_addr_list *to_list,
151 				 struct netdev_hw_addr_list *from_list,
152 				 struct netdev_hw_addr *ha,
153 				 int addr_len)
154 {
155 	int err;
156 
157 	err = __hw_addr_del_ex(to_list, ha->addr, addr_len, ha->type,
158 			       false, true);
159 	if (err)
160 		return;
161 	ha->sync_cnt--;
162 	__hw_addr_del_entry(from_list, ha, false, true);
163 }
164 
165 static int __hw_addr_sync_multiple(struct netdev_hw_addr_list *to_list,
166 				   struct netdev_hw_addr_list *from_list,
167 				   int addr_len)
168 {
169 	int err = 0;
170 	struct netdev_hw_addr *ha, *tmp;
171 
172 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
173 		if (ha->sync_cnt == ha->refcount) {
174 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
175 		} else {
176 			err = __hw_addr_sync_one(to_list, ha, addr_len);
177 			if (err)
178 				break;
179 		}
180 	}
181 	return err;
182 }
183 
184 int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
185 			   struct netdev_hw_addr_list *from_list,
186 			   int addr_len, unsigned char addr_type)
187 {
188 	int err;
189 	struct netdev_hw_addr *ha, *ha2;
190 	unsigned char type;
191 
192 	list_for_each_entry(ha, &from_list->list, list) {
193 		type = addr_type ? addr_type : ha->type;
194 		err = __hw_addr_add(to_list, ha->addr, addr_len, type);
195 		if (err)
196 			goto unroll;
197 	}
198 	return 0;
199 
200 unroll:
201 	list_for_each_entry(ha2, &from_list->list, list) {
202 		if (ha2 == ha)
203 			break;
204 		type = addr_type ? addr_type : ha2->type;
205 		__hw_addr_del(to_list, ha2->addr, addr_len, type);
206 	}
207 	return err;
208 }
209 EXPORT_SYMBOL(__hw_addr_add_multiple);
210 
211 void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
212 			    struct netdev_hw_addr_list *from_list,
213 			    int addr_len, unsigned char addr_type)
214 {
215 	struct netdev_hw_addr *ha;
216 	unsigned char type;
217 
218 	list_for_each_entry(ha, &from_list->list, list) {
219 		type = addr_type ? addr_type : ha->type;
220 		__hw_addr_del(to_list, ha->addr, addr_len, type);
221 	}
222 }
223 EXPORT_SYMBOL(__hw_addr_del_multiple);
224 
225 /* This function only works where there is a strict 1-1 relationship
226  * between source and destionation of they synch. If you ever need to
227  * sync addresses to more then 1 destination, you need to use
228  * __hw_addr_sync_multiple().
229  */
230 int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
231 		   struct netdev_hw_addr_list *from_list,
232 		   int addr_len)
233 {
234 	int err = 0;
235 	struct netdev_hw_addr *ha, *tmp;
236 
237 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
238 		if (!ha->sync_cnt) {
239 			err = __hw_addr_sync_one(to_list, ha, addr_len);
240 			if (err)
241 				break;
242 		} else if (ha->refcount == 1)
243 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
244 	}
245 	return err;
246 }
247 EXPORT_SYMBOL(__hw_addr_sync);
248 
249 void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
250 		      struct netdev_hw_addr_list *from_list,
251 		      int addr_len)
252 {
253 	struct netdev_hw_addr *ha, *tmp;
254 
255 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
256 		if (ha->sync_cnt)
257 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
258 	}
259 }
260 EXPORT_SYMBOL(__hw_addr_unsync);
261 
262 void __hw_addr_flush(struct netdev_hw_addr_list *list)
263 {
264 	struct netdev_hw_addr *ha, *tmp;
265 
266 	list_for_each_entry_safe(ha, tmp, &list->list, list) {
267 		list_del_rcu(&ha->list);
268 		kfree_rcu(ha, rcu_head);
269 	}
270 	list->count = 0;
271 }
272 EXPORT_SYMBOL(__hw_addr_flush);
273 
274 void __hw_addr_init(struct netdev_hw_addr_list *list)
275 {
276 	INIT_LIST_HEAD(&list->list);
277 	list->count = 0;
278 }
279 EXPORT_SYMBOL(__hw_addr_init);
280 
281 /*
282  * Device addresses handling functions
283  */
284 
285 /**
286  *	dev_addr_flush - Flush device address list
287  *	@dev: device
288  *
289  *	Flush device address list and reset ->dev_addr.
290  *
291  *	The caller must hold the rtnl_mutex.
292  */
293 void dev_addr_flush(struct net_device *dev)
294 {
295 	/* rtnl_mutex must be held here */
296 
297 	__hw_addr_flush(&dev->dev_addrs);
298 	dev->dev_addr = NULL;
299 }
300 EXPORT_SYMBOL(dev_addr_flush);
301 
302 /**
303  *	dev_addr_init - Init device address list
304  *	@dev: device
305  *
306  *	Init device address list and create the first element,
307  *	used by ->dev_addr.
308  *
309  *	The caller must hold the rtnl_mutex.
310  */
311 int dev_addr_init(struct net_device *dev)
312 {
313 	unsigned char addr[MAX_ADDR_LEN];
314 	struct netdev_hw_addr *ha;
315 	int err;
316 
317 	/* rtnl_mutex must be held here */
318 
319 	__hw_addr_init(&dev->dev_addrs);
320 	memset(addr, 0, sizeof(addr));
321 	err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
322 			    NETDEV_HW_ADDR_T_LAN);
323 	if (!err) {
324 		/*
325 		 * Get the first (previously created) address from the list
326 		 * and set dev_addr pointer to this location.
327 		 */
328 		ha = list_first_entry(&dev->dev_addrs.list,
329 				      struct netdev_hw_addr, list);
330 		dev->dev_addr = ha->addr;
331 	}
332 	return err;
333 }
334 EXPORT_SYMBOL(dev_addr_init);
335 
336 /**
337  *	dev_addr_add - Add a device address
338  *	@dev: device
339  *	@addr: address to add
340  *	@addr_type: address type
341  *
342  *	Add a device address to the device or increase the reference count if
343  *	it already exists.
344  *
345  *	The caller must hold the rtnl_mutex.
346  */
347 int dev_addr_add(struct net_device *dev, const unsigned char *addr,
348 		 unsigned char addr_type)
349 {
350 	int err;
351 
352 	ASSERT_RTNL();
353 
354 	err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
355 	if (!err)
356 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
357 	return err;
358 }
359 EXPORT_SYMBOL(dev_addr_add);
360 
361 /**
362  *	dev_addr_del - Release a device address.
363  *	@dev: device
364  *	@addr: address to delete
365  *	@addr_type: address type
366  *
367  *	Release reference to a device address and remove it from the device
368  *	if the reference count drops to zero.
369  *
370  *	The caller must hold the rtnl_mutex.
371  */
372 int dev_addr_del(struct net_device *dev, const unsigned char *addr,
373 		 unsigned char addr_type)
374 {
375 	int err;
376 	struct netdev_hw_addr *ha;
377 
378 	ASSERT_RTNL();
379 
380 	/*
381 	 * We can not remove the first address from the list because
382 	 * dev->dev_addr points to that.
383 	 */
384 	ha = list_first_entry(&dev->dev_addrs.list,
385 			      struct netdev_hw_addr, list);
386 	if (!memcmp(ha->addr, addr, dev->addr_len) &&
387 	    ha->type == addr_type && ha->refcount == 1)
388 		return -ENOENT;
389 
390 	err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
391 			    addr_type);
392 	if (!err)
393 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
394 	return err;
395 }
396 EXPORT_SYMBOL(dev_addr_del);
397 
398 /**
399  *	dev_addr_add_multiple - Add device addresses from another device
400  *	@to_dev: device to which addresses will be added
401  *	@from_dev: device from which addresses will be added
402  *	@addr_type: address type - 0 means type will be used from from_dev
403  *
404  *	Add device addresses of the one device to another.
405  **
406  *	The caller must hold the rtnl_mutex.
407  */
408 int dev_addr_add_multiple(struct net_device *to_dev,
409 			  struct net_device *from_dev,
410 			  unsigned char addr_type)
411 {
412 	int err;
413 
414 	ASSERT_RTNL();
415 
416 	if (from_dev->addr_len != to_dev->addr_len)
417 		return -EINVAL;
418 	err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
419 				     to_dev->addr_len, addr_type);
420 	if (!err)
421 		call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
422 	return err;
423 }
424 EXPORT_SYMBOL(dev_addr_add_multiple);
425 
426 /**
427  *	dev_addr_del_multiple - Delete device addresses by another device
428  *	@to_dev: device where the addresses will be deleted
429  *	@from_dev: device supplying the addresses to be deleted
430  *	@addr_type: address type - 0 means type will be used from from_dev
431  *
432  *	Deletes addresses in to device by the list of addresses in from device.
433  *
434  *	The caller must hold the rtnl_mutex.
435  */
436 int dev_addr_del_multiple(struct net_device *to_dev,
437 			  struct net_device *from_dev,
438 			  unsigned char addr_type)
439 {
440 	ASSERT_RTNL();
441 
442 	if (from_dev->addr_len != to_dev->addr_len)
443 		return -EINVAL;
444 	__hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
445 			       to_dev->addr_len, addr_type);
446 	call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
447 	return 0;
448 }
449 EXPORT_SYMBOL(dev_addr_del_multiple);
450 
451 /*
452  * Unicast list handling functions
453  */
454 
455 /**
456  *	dev_uc_add_excl - Add a global secondary unicast address
457  *	@dev: device
458  *	@addr: address to add
459  */
460 int dev_uc_add_excl(struct net_device *dev, const unsigned char *addr)
461 {
462 	struct netdev_hw_addr *ha;
463 	int err;
464 
465 	netif_addr_lock_bh(dev);
466 	list_for_each_entry(ha, &dev->uc.list, list) {
467 		if (!memcmp(ha->addr, addr, dev->addr_len) &&
468 		    ha->type == NETDEV_HW_ADDR_T_UNICAST) {
469 			err = -EEXIST;
470 			goto out;
471 		}
472 	}
473 	err = __hw_addr_create_ex(&dev->uc, addr, dev->addr_len,
474 				  NETDEV_HW_ADDR_T_UNICAST, true, false);
475 	if (!err)
476 		__dev_set_rx_mode(dev);
477 out:
478 	netif_addr_unlock_bh(dev);
479 	return err;
480 }
481 EXPORT_SYMBOL(dev_uc_add_excl);
482 
483 /**
484  *	dev_uc_add - Add a secondary unicast address
485  *	@dev: device
486  *	@addr: address to add
487  *
488  *	Add a secondary unicast address to the device or increase
489  *	the reference count if it already exists.
490  */
491 int dev_uc_add(struct net_device *dev, const unsigned char *addr)
492 {
493 	int err;
494 
495 	netif_addr_lock_bh(dev);
496 	err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
497 			    NETDEV_HW_ADDR_T_UNICAST);
498 	if (!err)
499 		__dev_set_rx_mode(dev);
500 	netif_addr_unlock_bh(dev);
501 	return err;
502 }
503 EXPORT_SYMBOL(dev_uc_add);
504 
505 /**
506  *	dev_uc_del - Release secondary unicast address.
507  *	@dev: device
508  *	@addr: address to delete
509  *
510  *	Release reference to a secondary unicast address and remove it
511  *	from the device if the reference count drops to zero.
512  */
513 int dev_uc_del(struct net_device *dev, const unsigned char *addr)
514 {
515 	int err;
516 
517 	netif_addr_lock_bh(dev);
518 	err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
519 			    NETDEV_HW_ADDR_T_UNICAST);
520 	if (!err)
521 		__dev_set_rx_mode(dev);
522 	netif_addr_unlock_bh(dev);
523 	return err;
524 }
525 EXPORT_SYMBOL(dev_uc_del);
526 
527 /**
528  *	dev_uc_sync - Synchronize device's unicast list to another device
529  *	@to: destination device
530  *	@from: source device
531  *
532  *	Add newly added addresses to the destination device and release
533  *	addresses that have no users left. The source device must be
534  *	locked by netif_addr_lock_bh.
535  *
536  *	This function is intended to be called from the dev->set_rx_mode
537  *	function of layered software devices.  This function assumes that
538  *	addresses will only ever be synced to the @to devices and no other.
539  */
540 int dev_uc_sync(struct net_device *to, struct net_device *from)
541 {
542 	int err = 0;
543 
544 	if (to->addr_len != from->addr_len)
545 		return -EINVAL;
546 
547 	netif_addr_lock_nested(to);
548 	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
549 	if (!err)
550 		__dev_set_rx_mode(to);
551 	netif_addr_unlock(to);
552 	return err;
553 }
554 EXPORT_SYMBOL(dev_uc_sync);
555 
556 /**
557  *	dev_uc_sync_multiple - Synchronize device's unicast list to another
558  *	device, but allow for multiple calls to sync to multiple devices.
559  *	@to: destination device
560  *	@from: source device
561  *
562  *	Add newly added addresses to the destination device and release
563  *	addresses that have been deleted from the source. The source device
564  *	must be locked by netif_addr_lock_bh.
565  *
566  *	This function is intended to be called from the dev->set_rx_mode
567  *	function of layered software devices.  It allows for a single source
568  *	device to be synced to multiple destination devices.
569  */
570 int dev_uc_sync_multiple(struct net_device *to, struct net_device *from)
571 {
572 	int err = 0;
573 
574 	if (to->addr_len != from->addr_len)
575 		return -EINVAL;
576 
577 	netif_addr_lock_nested(to);
578 	err = __hw_addr_sync_multiple(&to->uc, &from->uc, to->addr_len);
579 	if (!err)
580 		__dev_set_rx_mode(to);
581 	netif_addr_unlock(to);
582 	return err;
583 }
584 EXPORT_SYMBOL(dev_uc_sync_multiple);
585 
586 /**
587  *	dev_uc_unsync - Remove synchronized addresses from the destination device
588  *	@to: destination device
589  *	@from: source device
590  *
591  *	Remove all addresses that were added to the destination device by
592  *	dev_uc_sync(). This function is intended to be called from the
593  *	dev->stop function of layered software devices.
594  */
595 void dev_uc_unsync(struct net_device *to, struct net_device *from)
596 {
597 	if (to->addr_len != from->addr_len)
598 		return;
599 
600 	netif_addr_lock_bh(from);
601 	netif_addr_lock_nested(to);
602 	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
603 	__dev_set_rx_mode(to);
604 	netif_addr_unlock(to);
605 	netif_addr_unlock_bh(from);
606 }
607 EXPORT_SYMBOL(dev_uc_unsync);
608 
609 /**
610  *	dev_uc_flush - Flush unicast addresses
611  *	@dev: device
612  *
613  *	Flush unicast addresses.
614  */
615 void dev_uc_flush(struct net_device *dev)
616 {
617 	netif_addr_lock_bh(dev);
618 	__hw_addr_flush(&dev->uc);
619 	netif_addr_unlock_bh(dev);
620 }
621 EXPORT_SYMBOL(dev_uc_flush);
622 
623 /**
624  *	dev_uc_flush - Init unicast address list
625  *	@dev: device
626  *
627  *	Init unicast address list.
628  */
629 void dev_uc_init(struct net_device *dev)
630 {
631 	__hw_addr_init(&dev->uc);
632 }
633 EXPORT_SYMBOL(dev_uc_init);
634 
635 /*
636  * Multicast list handling functions
637  */
638 
639 /**
640  *	dev_mc_add_excl - Add a global secondary multicast address
641  *	@dev: device
642  *	@addr: address to add
643  */
644 int dev_mc_add_excl(struct net_device *dev, const unsigned char *addr)
645 {
646 	struct netdev_hw_addr *ha;
647 	int err;
648 
649 	netif_addr_lock_bh(dev);
650 	list_for_each_entry(ha, &dev->mc.list, list) {
651 		if (!memcmp(ha->addr, addr, dev->addr_len) &&
652 		    ha->type == NETDEV_HW_ADDR_T_MULTICAST) {
653 			err = -EEXIST;
654 			goto out;
655 		}
656 	}
657 	err = __hw_addr_create_ex(&dev->mc, addr, dev->addr_len,
658 				  NETDEV_HW_ADDR_T_MULTICAST, true, false);
659 	if (!err)
660 		__dev_set_rx_mode(dev);
661 out:
662 	netif_addr_unlock_bh(dev);
663 	return err;
664 }
665 EXPORT_SYMBOL(dev_mc_add_excl);
666 
667 static int __dev_mc_add(struct net_device *dev, const unsigned char *addr,
668 			bool global)
669 {
670 	int err;
671 
672 	netif_addr_lock_bh(dev);
673 	err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
674 			       NETDEV_HW_ADDR_T_MULTICAST, global, false);
675 	if (!err)
676 		__dev_set_rx_mode(dev);
677 	netif_addr_unlock_bh(dev);
678 	return err;
679 }
680 /**
681  *	dev_mc_add - Add a multicast address
682  *	@dev: device
683  *	@addr: address to add
684  *
685  *	Add a multicast address to the device or increase
686  *	the reference count if it already exists.
687  */
688 int dev_mc_add(struct net_device *dev, const unsigned char *addr)
689 {
690 	return __dev_mc_add(dev, addr, false);
691 }
692 EXPORT_SYMBOL(dev_mc_add);
693 
694 /**
695  *	dev_mc_add_global - Add a global multicast address
696  *	@dev: device
697  *	@addr: address to add
698  *
699  *	Add a global multicast address to the device.
700  */
701 int dev_mc_add_global(struct net_device *dev, const unsigned char *addr)
702 {
703 	return __dev_mc_add(dev, addr, true);
704 }
705 EXPORT_SYMBOL(dev_mc_add_global);
706 
707 static int __dev_mc_del(struct net_device *dev, const unsigned char *addr,
708 			bool global)
709 {
710 	int err;
711 
712 	netif_addr_lock_bh(dev);
713 	err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
714 			       NETDEV_HW_ADDR_T_MULTICAST, global, false);
715 	if (!err)
716 		__dev_set_rx_mode(dev);
717 	netif_addr_unlock_bh(dev);
718 	return err;
719 }
720 
721 /**
722  *	dev_mc_del - Delete a multicast address.
723  *	@dev: device
724  *	@addr: address to delete
725  *
726  *	Release reference to a multicast address and remove it
727  *	from the device if the reference count drops to zero.
728  */
729 int dev_mc_del(struct net_device *dev, const unsigned char *addr)
730 {
731 	return __dev_mc_del(dev, addr, false);
732 }
733 EXPORT_SYMBOL(dev_mc_del);
734 
735 /**
736  *	dev_mc_del_global - Delete a global multicast address.
737  *	@dev: device
738  *	@addr: address to delete
739  *
740  *	Release reference to a multicast address and remove it
741  *	from the device if the reference count drops to zero.
742  */
743 int dev_mc_del_global(struct net_device *dev, const unsigned char *addr)
744 {
745 	return __dev_mc_del(dev, addr, true);
746 }
747 EXPORT_SYMBOL(dev_mc_del_global);
748 
749 /**
750  *	dev_mc_sync - Synchronize device's unicast list to another device
751  *	@to: destination device
752  *	@from: source device
753  *
754  *	Add newly added addresses to the destination device and release
755  *	addresses that have no users left. The source device must be
756  *	locked by netif_addr_lock_bh.
757  *
758  *	This function is intended to be called from the ndo_set_rx_mode
759  *	function of layered software devices.
760  */
761 int dev_mc_sync(struct net_device *to, struct net_device *from)
762 {
763 	int err = 0;
764 
765 	if (to->addr_len != from->addr_len)
766 		return -EINVAL;
767 
768 	netif_addr_lock_nested(to);
769 	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
770 	if (!err)
771 		__dev_set_rx_mode(to);
772 	netif_addr_unlock(to);
773 	return err;
774 }
775 EXPORT_SYMBOL(dev_mc_sync);
776 
777 /**
778  *	dev_mc_sync_multiple - Synchronize device's unicast list to another
779  *	device, but allow for multiple calls to sync to multiple devices.
780  *	@to: destination device
781  *	@from: source device
782  *
783  *	Add newly added addresses to the destination device and release
784  *	addresses that have no users left. The source device must be
785  *	locked by netif_addr_lock_bh.
786  *
787  *	This function is intended to be called from the ndo_set_rx_mode
788  *	function of layered software devices.  It allows for a single
789  *	source device to be synced to multiple destination devices.
790  */
791 int dev_mc_sync_multiple(struct net_device *to, struct net_device *from)
792 {
793 	int err = 0;
794 
795 	if (to->addr_len != from->addr_len)
796 		return -EINVAL;
797 
798 	netif_addr_lock_nested(to);
799 	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
800 	if (!err)
801 		__dev_set_rx_mode(to);
802 	netif_addr_unlock(to);
803 	return err;
804 }
805 EXPORT_SYMBOL(dev_mc_sync_multiple);
806 
807 /**
808  *	dev_mc_unsync - Remove synchronized addresses from the destination device
809  *	@to: destination device
810  *	@from: source device
811  *
812  *	Remove all addresses that were added to the destination device by
813  *	dev_mc_sync(). This function is intended to be called from the
814  *	dev->stop function of layered software devices.
815  */
816 void dev_mc_unsync(struct net_device *to, struct net_device *from)
817 {
818 	if (to->addr_len != from->addr_len)
819 		return;
820 
821 	netif_addr_lock_bh(from);
822 	netif_addr_lock_nested(to);
823 	__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
824 	__dev_set_rx_mode(to);
825 	netif_addr_unlock(to);
826 	netif_addr_unlock_bh(from);
827 }
828 EXPORT_SYMBOL(dev_mc_unsync);
829 
830 /**
831  *	dev_mc_flush - Flush multicast addresses
832  *	@dev: device
833  *
834  *	Flush multicast addresses.
835  */
836 void dev_mc_flush(struct net_device *dev)
837 {
838 	netif_addr_lock_bh(dev);
839 	__hw_addr_flush(&dev->mc);
840 	netif_addr_unlock_bh(dev);
841 }
842 EXPORT_SYMBOL(dev_mc_flush);
843 
844 /**
845  *	dev_mc_flush - Init multicast address list
846  *	@dev: device
847  *
848  *	Init multicast address list.
849  */
850 void dev_mc_init(struct net_device *dev)
851 {
852 	__hw_addr_init(&dev->mc);
853 }
854 EXPORT_SYMBOL(dev_mc_init);
855