xref: /openbmc/linux/net/core/dev_addr_lists.c (revision c4ee0af3)
1 /*
2  * net/core/dev_addr_lists.c - Functions for handling net device lists
3  * Copyright (c) 2010 Jiri Pirko <jpirko@redhat.com>
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 	ha->sync_cnt = 0;
43 	list_add_tail_rcu(&ha->list, &list->list);
44 	list->count++;
45 
46 	return 0;
47 }
48 
49 static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
50 			    const unsigned char *addr, int addr_len,
51 			    unsigned char addr_type, bool global, bool sync)
52 {
53 	struct netdev_hw_addr *ha;
54 
55 	if (addr_len > MAX_ADDR_LEN)
56 		return -EINVAL;
57 
58 	list_for_each_entry(ha, &list->list, list) {
59 		if (!memcmp(ha->addr, addr, addr_len) &&
60 		    ha->type == addr_type) {
61 			if (global) {
62 				/* check if addr is already used as global */
63 				if (ha->global_use)
64 					return 0;
65 				else
66 					ha->global_use = true;
67 			}
68 			if (sync) {
69 				if (ha->synced)
70 					return -EEXIST;
71 				else
72 					ha->synced = true;
73 			}
74 			ha->refcount++;
75 			return 0;
76 		}
77 	}
78 
79 	return __hw_addr_create_ex(list, addr, addr_len, addr_type, global,
80 				   sync);
81 }
82 
83 static int __hw_addr_add(struct netdev_hw_addr_list *list,
84 			 const unsigned char *addr, int addr_len,
85 			 unsigned char addr_type)
86 {
87 	return __hw_addr_add_ex(list, addr, addr_len, addr_type, false, false);
88 }
89 
90 static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
91 			       struct netdev_hw_addr *ha, bool global,
92 			       bool sync)
93 {
94 	if (global && !ha->global_use)
95 		return -ENOENT;
96 
97 	if (sync && !ha->synced)
98 		return -ENOENT;
99 
100 	if (global)
101 		ha->global_use = false;
102 
103 	if (sync)
104 		ha->synced = false;
105 
106 	if (--ha->refcount)
107 		return 0;
108 	list_del_rcu(&ha->list);
109 	kfree_rcu(ha, rcu_head);
110 	list->count--;
111 	return 0;
112 }
113 
114 static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
115 			    const unsigned char *addr, int addr_len,
116 			    unsigned char addr_type, bool global, bool sync)
117 {
118 	struct netdev_hw_addr *ha;
119 
120 	list_for_each_entry(ha, &list->list, list) {
121 		if (!memcmp(ha->addr, addr, addr_len) &&
122 		    (ha->type == addr_type || !addr_type))
123 			return __hw_addr_del_entry(list, ha, global, sync);
124 	}
125 	return -ENOENT;
126 }
127 
128 static int __hw_addr_del(struct netdev_hw_addr_list *list,
129 			 const unsigned char *addr, int addr_len,
130 			 unsigned char addr_type)
131 {
132 	return __hw_addr_del_ex(list, addr, addr_len, addr_type, false, false);
133 }
134 
135 static int __hw_addr_sync_one(struct netdev_hw_addr_list *to_list,
136 			       struct netdev_hw_addr *ha,
137 			       int addr_len)
138 {
139 	int err;
140 
141 	err = __hw_addr_add_ex(to_list, ha->addr, addr_len, ha->type,
142 			       false, true);
143 	if (err && err != -EEXIST)
144 		return err;
145 
146 	if (!err) {
147 		ha->sync_cnt++;
148 		ha->refcount++;
149 	}
150 
151 	return 0;
152 }
153 
154 static void __hw_addr_unsync_one(struct netdev_hw_addr_list *to_list,
155 				 struct netdev_hw_addr_list *from_list,
156 				 struct netdev_hw_addr *ha,
157 				 int addr_len)
158 {
159 	int err;
160 
161 	err = __hw_addr_del_ex(to_list, ha->addr, addr_len, ha->type,
162 			       false, true);
163 	if (err)
164 		return;
165 	ha->sync_cnt--;
166 	/* address on from list is not marked synced */
167 	__hw_addr_del_entry(from_list, ha, false, false);
168 }
169 
170 static int __hw_addr_sync_multiple(struct netdev_hw_addr_list *to_list,
171 				   struct netdev_hw_addr_list *from_list,
172 				   int addr_len)
173 {
174 	int err = 0;
175 	struct netdev_hw_addr *ha, *tmp;
176 
177 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
178 		if (ha->sync_cnt == ha->refcount) {
179 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
180 		} else {
181 			err = __hw_addr_sync_one(to_list, ha, addr_len);
182 			if (err)
183 				break;
184 		}
185 	}
186 	return err;
187 }
188 
189 int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
190 			   struct netdev_hw_addr_list *from_list,
191 			   int addr_len, unsigned char addr_type)
192 {
193 	int err;
194 	struct netdev_hw_addr *ha, *ha2;
195 	unsigned char type;
196 
197 	list_for_each_entry(ha, &from_list->list, list) {
198 		type = addr_type ? addr_type : ha->type;
199 		err = __hw_addr_add(to_list, ha->addr, addr_len, type);
200 		if (err)
201 			goto unroll;
202 	}
203 	return 0;
204 
205 unroll:
206 	list_for_each_entry(ha2, &from_list->list, list) {
207 		if (ha2 == ha)
208 			break;
209 		type = addr_type ? addr_type : ha2->type;
210 		__hw_addr_del(to_list, ha2->addr, addr_len, type);
211 	}
212 	return err;
213 }
214 EXPORT_SYMBOL(__hw_addr_add_multiple);
215 
216 void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
217 			    struct netdev_hw_addr_list *from_list,
218 			    int addr_len, unsigned char addr_type)
219 {
220 	struct netdev_hw_addr *ha;
221 	unsigned char type;
222 
223 	list_for_each_entry(ha, &from_list->list, list) {
224 		type = addr_type ? addr_type : ha->type;
225 		__hw_addr_del(to_list, ha->addr, addr_len, type);
226 	}
227 }
228 EXPORT_SYMBOL(__hw_addr_del_multiple);
229 
230 /* This function only works where there is a strict 1-1 relationship
231  * between source and destionation of they synch. If you ever need to
232  * sync addresses to more then 1 destination, you need to use
233  * __hw_addr_sync_multiple().
234  */
235 int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
236 		   struct netdev_hw_addr_list *from_list,
237 		   int addr_len)
238 {
239 	int err = 0;
240 	struct netdev_hw_addr *ha, *tmp;
241 
242 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
243 		if (!ha->sync_cnt) {
244 			err = __hw_addr_sync_one(to_list, ha, addr_len);
245 			if (err)
246 				break;
247 		} else if (ha->refcount == 1)
248 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
249 	}
250 	return err;
251 }
252 EXPORT_SYMBOL(__hw_addr_sync);
253 
254 void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
255 		      struct netdev_hw_addr_list *from_list,
256 		      int addr_len)
257 {
258 	struct netdev_hw_addr *ha, *tmp;
259 
260 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
261 		if (ha->sync_cnt)
262 			__hw_addr_unsync_one(to_list, from_list, ha, addr_len);
263 	}
264 }
265 EXPORT_SYMBOL(__hw_addr_unsync);
266 
267 void __hw_addr_flush(struct netdev_hw_addr_list *list)
268 {
269 	struct netdev_hw_addr *ha, *tmp;
270 
271 	list_for_each_entry_safe(ha, tmp, &list->list, list) {
272 		list_del_rcu(&ha->list);
273 		kfree_rcu(ha, rcu_head);
274 	}
275 	list->count = 0;
276 }
277 EXPORT_SYMBOL(__hw_addr_flush);
278 
279 void __hw_addr_init(struct netdev_hw_addr_list *list)
280 {
281 	INIT_LIST_HEAD(&list->list);
282 	list->count = 0;
283 }
284 EXPORT_SYMBOL(__hw_addr_init);
285 
286 /*
287  * Device addresses handling functions
288  */
289 
290 /**
291  *	dev_addr_flush - Flush device address list
292  *	@dev: device
293  *
294  *	Flush device address list and reset ->dev_addr.
295  *
296  *	The caller must hold the rtnl_mutex.
297  */
298 void dev_addr_flush(struct net_device *dev)
299 {
300 	/* rtnl_mutex must be held here */
301 
302 	__hw_addr_flush(&dev->dev_addrs);
303 	dev->dev_addr = NULL;
304 }
305 EXPORT_SYMBOL(dev_addr_flush);
306 
307 /**
308  *	dev_addr_init - Init device address list
309  *	@dev: device
310  *
311  *	Init device address list and create the first element,
312  *	used by ->dev_addr.
313  *
314  *	The caller must hold the rtnl_mutex.
315  */
316 int dev_addr_init(struct net_device *dev)
317 {
318 	unsigned char addr[MAX_ADDR_LEN];
319 	struct netdev_hw_addr *ha;
320 	int err;
321 
322 	/* rtnl_mutex must be held here */
323 
324 	__hw_addr_init(&dev->dev_addrs);
325 	memset(addr, 0, sizeof(addr));
326 	err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
327 			    NETDEV_HW_ADDR_T_LAN);
328 	if (!err) {
329 		/*
330 		 * Get the first (previously created) address from the list
331 		 * and set dev_addr pointer to this location.
332 		 */
333 		ha = list_first_entry(&dev->dev_addrs.list,
334 				      struct netdev_hw_addr, list);
335 		dev->dev_addr = ha->addr;
336 	}
337 	return err;
338 }
339 EXPORT_SYMBOL(dev_addr_init);
340 
341 /**
342  *	dev_addr_add - Add a device address
343  *	@dev: device
344  *	@addr: address to add
345  *	@addr_type: address type
346  *
347  *	Add a device address to the device or increase the reference count if
348  *	it already exists.
349  *
350  *	The caller must hold the rtnl_mutex.
351  */
352 int dev_addr_add(struct net_device *dev, const unsigned char *addr,
353 		 unsigned char addr_type)
354 {
355 	int err;
356 
357 	ASSERT_RTNL();
358 
359 	err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
360 	if (!err)
361 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
362 	return err;
363 }
364 EXPORT_SYMBOL(dev_addr_add);
365 
366 /**
367  *	dev_addr_del - Release a device address.
368  *	@dev: device
369  *	@addr: address to delete
370  *	@addr_type: address type
371  *
372  *	Release reference to a device address and remove it from the device
373  *	if the reference count drops to zero.
374  *
375  *	The caller must hold the rtnl_mutex.
376  */
377 int dev_addr_del(struct net_device *dev, const unsigned char *addr,
378 		 unsigned char addr_type)
379 {
380 	int err;
381 	struct netdev_hw_addr *ha;
382 
383 	ASSERT_RTNL();
384 
385 	/*
386 	 * We can not remove the first address from the list because
387 	 * dev->dev_addr points to that.
388 	 */
389 	ha = list_first_entry(&dev->dev_addrs.list,
390 			      struct netdev_hw_addr, list);
391 	if (!memcmp(ha->addr, addr, dev->addr_len) &&
392 	    ha->type == addr_type && ha->refcount == 1)
393 		return -ENOENT;
394 
395 	err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
396 			    addr_type);
397 	if (!err)
398 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
399 	return err;
400 }
401 EXPORT_SYMBOL(dev_addr_del);
402 
403 /**
404  *	dev_addr_add_multiple - Add device addresses from another device
405  *	@to_dev: device to which addresses will be added
406  *	@from_dev: device from which addresses will be added
407  *	@addr_type: address type - 0 means type will be used from from_dev
408  *
409  *	Add device addresses of the one device to another.
410  **
411  *	The caller must hold the rtnl_mutex.
412  */
413 int dev_addr_add_multiple(struct net_device *to_dev,
414 			  struct net_device *from_dev,
415 			  unsigned char addr_type)
416 {
417 	int err;
418 
419 	ASSERT_RTNL();
420 
421 	if (from_dev->addr_len != to_dev->addr_len)
422 		return -EINVAL;
423 	err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
424 				     to_dev->addr_len, addr_type);
425 	if (!err)
426 		call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
427 	return err;
428 }
429 EXPORT_SYMBOL(dev_addr_add_multiple);
430 
431 /**
432  *	dev_addr_del_multiple - Delete device addresses by another device
433  *	@to_dev: device where the addresses will be deleted
434  *	@from_dev: device supplying the addresses to be deleted
435  *	@addr_type: address type - 0 means type will be used from from_dev
436  *
437  *	Deletes addresses in to device by the list of addresses in from device.
438  *
439  *	The caller must hold the rtnl_mutex.
440  */
441 int dev_addr_del_multiple(struct net_device *to_dev,
442 			  struct net_device *from_dev,
443 			  unsigned char addr_type)
444 {
445 	ASSERT_RTNL();
446 
447 	if (from_dev->addr_len != to_dev->addr_len)
448 		return -EINVAL;
449 	__hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
450 			       to_dev->addr_len, addr_type);
451 	call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
452 	return 0;
453 }
454 EXPORT_SYMBOL(dev_addr_del_multiple);
455 
456 /*
457  * Unicast list handling functions
458  */
459 
460 /**
461  *	dev_uc_add_excl - Add a global secondary unicast address
462  *	@dev: device
463  *	@addr: address to add
464  */
465 int dev_uc_add_excl(struct net_device *dev, const unsigned char *addr)
466 {
467 	struct netdev_hw_addr *ha;
468 	int err;
469 
470 	netif_addr_lock_bh(dev);
471 	list_for_each_entry(ha, &dev->uc.list, list) {
472 		if (!memcmp(ha->addr, addr, dev->addr_len) &&
473 		    ha->type == NETDEV_HW_ADDR_T_UNICAST) {
474 			err = -EEXIST;
475 			goto out;
476 		}
477 	}
478 	err = __hw_addr_create_ex(&dev->uc, addr, dev->addr_len,
479 				  NETDEV_HW_ADDR_T_UNICAST, true, false);
480 	if (!err)
481 		__dev_set_rx_mode(dev);
482 out:
483 	netif_addr_unlock_bh(dev);
484 	return err;
485 }
486 EXPORT_SYMBOL(dev_uc_add_excl);
487 
488 /**
489  *	dev_uc_add - Add a secondary unicast address
490  *	@dev: device
491  *	@addr: address to add
492  *
493  *	Add a secondary unicast address to the device or increase
494  *	the reference count if it already exists.
495  */
496 int dev_uc_add(struct net_device *dev, const unsigned char *addr)
497 {
498 	int err;
499 
500 	netif_addr_lock_bh(dev);
501 	err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
502 			    NETDEV_HW_ADDR_T_UNICAST);
503 	if (!err)
504 		__dev_set_rx_mode(dev);
505 	netif_addr_unlock_bh(dev);
506 	return err;
507 }
508 EXPORT_SYMBOL(dev_uc_add);
509 
510 /**
511  *	dev_uc_del - Release secondary unicast address.
512  *	@dev: device
513  *	@addr: address to delete
514  *
515  *	Release reference to a secondary unicast address and remove it
516  *	from the device if the reference count drops to zero.
517  */
518 int dev_uc_del(struct net_device *dev, const unsigned char *addr)
519 {
520 	int err;
521 
522 	netif_addr_lock_bh(dev);
523 	err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
524 			    NETDEV_HW_ADDR_T_UNICAST);
525 	if (!err)
526 		__dev_set_rx_mode(dev);
527 	netif_addr_unlock_bh(dev);
528 	return err;
529 }
530 EXPORT_SYMBOL(dev_uc_del);
531 
532 /**
533  *	dev_uc_sync - Synchronize device's unicast list to another device
534  *	@to: destination device
535  *	@from: source device
536  *
537  *	Add newly added addresses to the destination device and release
538  *	addresses that have no users left. The source device must be
539  *	locked by netif_addr_lock_bh.
540  *
541  *	This function is intended to be called from the dev->set_rx_mode
542  *	function of layered software devices.  This function assumes that
543  *	addresses will only ever be synced to the @to devices and no other.
544  */
545 int dev_uc_sync(struct net_device *to, struct net_device *from)
546 {
547 	int err = 0;
548 
549 	if (to->addr_len != from->addr_len)
550 		return -EINVAL;
551 
552 	netif_addr_lock_nested(to);
553 	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
554 	if (!err)
555 		__dev_set_rx_mode(to);
556 	netif_addr_unlock(to);
557 	return err;
558 }
559 EXPORT_SYMBOL(dev_uc_sync);
560 
561 /**
562  *	dev_uc_sync_multiple - Synchronize device's unicast list to another
563  *	device, but allow for multiple calls to sync to multiple devices.
564  *	@to: destination device
565  *	@from: source device
566  *
567  *	Add newly added addresses to the destination device and release
568  *	addresses that have been deleted from the source. The source device
569  *	must be locked by netif_addr_lock_bh.
570  *
571  *	This function is intended to be called from the dev->set_rx_mode
572  *	function of layered software devices.  It allows for a single source
573  *	device to be synced to multiple destination devices.
574  */
575 int dev_uc_sync_multiple(struct net_device *to, struct net_device *from)
576 {
577 	int err = 0;
578 
579 	if (to->addr_len != from->addr_len)
580 		return -EINVAL;
581 
582 	netif_addr_lock_nested(to);
583 	err = __hw_addr_sync_multiple(&to->uc, &from->uc, to->addr_len);
584 	if (!err)
585 		__dev_set_rx_mode(to);
586 	netif_addr_unlock(to);
587 	return err;
588 }
589 EXPORT_SYMBOL(dev_uc_sync_multiple);
590 
591 /**
592  *	dev_uc_unsync - Remove synchronized addresses from the destination device
593  *	@to: destination device
594  *	@from: source device
595  *
596  *	Remove all addresses that were added to the destination device by
597  *	dev_uc_sync(). This function is intended to be called from the
598  *	dev->stop function of layered software devices.
599  */
600 void dev_uc_unsync(struct net_device *to, struct net_device *from)
601 {
602 	if (to->addr_len != from->addr_len)
603 		return;
604 
605 	netif_addr_lock_bh(from);
606 	netif_addr_lock_nested(to);
607 	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
608 	__dev_set_rx_mode(to);
609 	netif_addr_unlock(to);
610 	netif_addr_unlock_bh(from);
611 }
612 EXPORT_SYMBOL(dev_uc_unsync);
613 
614 /**
615  *	dev_uc_flush - Flush unicast addresses
616  *	@dev: device
617  *
618  *	Flush unicast addresses.
619  */
620 void dev_uc_flush(struct net_device *dev)
621 {
622 	netif_addr_lock_bh(dev);
623 	__hw_addr_flush(&dev->uc);
624 	netif_addr_unlock_bh(dev);
625 }
626 EXPORT_SYMBOL(dev_uc_flush);
627 
628 /**
629  *	dev_uc_flush - Init unicast address list
630  *	@dev: device
631  *
632  *	Init unicast address list.
633  */
634 void dev_uc_init(struct net_device *dev)
635 {
636 	__hw_addr_init(&dev->uc);
637 }
638 EXPORT_SYMBOL(dev_uc_init);
639 
640 /*
641  * Multicast list handling functions
642  */
643 
644 /**
645  *	dev_mc_add_excl - Add a global secondary multicast address
646  *	@dev: device
647  *	@addr: address to add
648  */
649 int dev_mc_add_excl(struct net_device *dev, const unsigned char *addr)
650 {
651 	struct netdev_hw_addr *ha;
652 	int err;
653 
654 	netif_addr_lock_bh(dev);
655 	list_for_each_entry(ha, &dev->mc.list, list) {
656 		if (!memcmp(ha->addr, addr, dev->addr_len) &&
657 		    ha->type == NETDEV_HW_ADDR_T_MULTICAST) {
658 			err = -EEXIST;
659 			goto out;
660 		}
661 	}
662 	err = __hw_addr_create_ex(&dev->mc, addr, dev->addr_len,
663 				  NETDEV_HW_ADDR_T_MULTICAST, true, false);
664 	if (!err)
665 		__dev_set_rx_mode(dev);
666 out:
667 	netif_addr_unlock_bh(dev);
668 	return err;
669 }
670 EXPORT_SYMBOL(dev_mc_add_excl);
671 
672 static int __dev_mc_add(struct net_device *dev, const unsigned char *addr,
673 			bool global)
674 {
675 	int err;
676 
677 	netif_addr_lock_bh(dev);
678 	err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
679 			       NETDEV_HW_ADDR_T_MULTICAST, global, false);
680 	if (!err)
681 		__dev_set_rx_mode(dev);
682 	netif_addr_unlock_bh(dev);
683 	return err;
684 }
685 /**
686  *	dev_mc_add - Add a multicast address
687  *	@dev: device
688  *	@addr: address to add
689  *
690  *	Add a multicast address to the device or increase
691  *	the reference count if it already exists.
692  */
693 int dev_mc_add(struct net_device *dev, const unsigned char *addr)
694 {
695 	return __dev_mc_add(dev, addr, false);
696 }
697 EXPORT_SYMBOL(dev_mc_add);
698 
699 /**
700  *	dev_mc_add_global - Add a global multicast address
701  *	@dev: device
702  *	@addr: address to add
703  *
704  *	Add a global multicast address to the device.
705  */
706 int dev_mc_add_global(struct net_device *dev, const unsigned char *addr)
707 {
708 	return __dev_mc_add(dev, addr, true);
709 }
710 EXPORT_SYMBOL(dev_mc_add_global);
711 
712 static int __dev_mc_del(struct net_device *dev, const unsigned char *addr,
713 			bool global)
714 {
715 	int err;
716 
717 	netif_addr_lock_bh(dev);
718 	err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
719 			       NETDEV_HW_ADDR_T_MULTICAST, global, false);
720 	if (!err)
721 		__dev_set_rx_mode(dev);
722 	netif_addr_unlock_bh(dev);
723 	return err;
724 }
725 
726 /**
727  *	dev_mc_del - Delete a multicast address.
728  *	@dev: device
729  *	@addr: address to delete
730  *
731  *	Release reference to a multicast address and remove it
732  *	from the device if the reference count drops to zero.
733  */
734 int dev_mc_del(struct net_device *dev, const unsigned char *addr)
735 {
736 	return __dev_mc_del(dev, addr, false);
737 }
738 EXPORT_SYMBOL(dev_mc_del);
739 
740 /**
741  *	dev_mc_del_global - Delete a global multicast address.
742  *	@dev: device
743  *	@addr: address to delete
744  *
745  *	Release reference to a multicast address and remove it
746  *	from the device if the reference count drops to zero.
747  */
748 int dev_mc_del_global(struct net_device *dev, const unsigned char *addr)
749 {
750 	return __dev_mc_del(dev, addr, true);
751 }
752 EXPORT_SYMBOL(dev_mc_del_global);
753 
754 /**
755  *	dev_mc_sync - Synchronize device's multicast list to another device
756  *	@to: destination device
757  *	@from: source device
758  *
759  *	Add newly added addresses to the destination device and release
760  *	addresses that have no users left. The source device must be
761  *	locked by netif_addr_lock_bh.
762  *
763  *	This function is intended to be called from the ndo_set_rx_mode
764  *	function of layered software devices.
765  */
766 int dev_mc_sync(struct net_device *to, struct net_device *from)
767 {
768 	int err = 0;
769 
770 	if (to->addr_len != from->addr_len)
771 		return -EINVAL;
772 
773 	netif_addr_lock_nested(to);
774 	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
775 	if (!err)
776 		__dev_set_rx_mode(to);
777 	netif_addr_unlock(to);
778 	return err;
779 }
780 EXPORT_SYMBOL(dev_mc_sync);
781 
782 /**
783  *	dev_mc_sync_multiple - Synchronize device's multicast list to another
784  *	device, but allow for multiple calls to sync to multiple devices.
785  *	@to: destination device
786  *	@from: source device
787  *
788  *	Add newly added addresses to the destination device and release
789  *	addresses that have no users left. The source device must be
790  *	locked by netif_addr_lock_bh.
791  *
792  *	This function is intended to be called from the ndo_set_rx_mode
793  *	function of layered software devices.  It allows for a single
794  *	source device to be synced to multiple destination devices.
795  */
796 int dev_mc_sync_multiple(struct net_device *to, struct net_device *from)
797 {
798 	int err = 0;
799 
800 	if (to->addr_len != from->addr_len)
801 		return -EINVAL;
802 
803 	netif_addr_lock_nested(to);
804 	err = __hw_addr_sync_multiple(&to->mc, &from->mc, to->addr_len);
805 	if (!err)
806 		__dev_set_rx_mode(to);
807 	netif_addr_unlock(to);
808 	return err;
809 }
810 EXPORT_SYMBOL(dev_mc_sync_multiple);
811 
812 /**
813  *	dev_mc_unsync - Remove synchronized addresses from the destination device
814  *	@to: destination device
815  *	@from: source device
816  *
817  *	Remove all addresses that were added to the destination device by
818  *	dev_mc_sync(). This function is intended to be called from the
819  *	dev->stop function of layered software devices.
820  */
821 void dev_mc_unsync(struct net_device *to, struct net_device *from)
822 {
823 	if (to->addr_len != from->addr_len)
824 		return;
825 
826 	netif_addr_lock_bh(from);
827 	netif_addr_lock_nested(to);
828 	__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
829 	__dev_set_rx_mode(to);
830 	netif_addr_unlock(to);
831 	netif_addr_unlock_bh(from);
832 }
833 EXPORT_SYMBOL(dev_mc_unsync);
834 
835 /**
836  *	dev_mc_flush - Flush multicast addresses
837  *	@dev: device
838  *
839  *	Flush multicast addresses.
840  */
841 void dev_mc_flush(struct net_device *dev)
842 {
843 	netif_addr_lock_bh(dev);
844 	__hw_addr_flush(&dev->mc);
845 	netif_addr_unlock_bh(dev);
846 }
847 EXPORT_SYMBOL(dev_mc_flush);
848 
849 /**
850  *	dev_mc_flush - Init multicast address list
851  *	@dev: device
852  *
853  *	Init multicast address list.
854  */
855 void dev_mc_init(struct net_device *dev)
856 {
857 	__hw_addr_init(&dev->mc);
858 }
859 EXPORT_SYMBOL(dev_mc_init);
860