xref: /linux/net/batman-adv/multicast.c (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
3  *
4  * Linus Lüssing
5  */
6 
7 #include "multicast.h"
8 #include "main.h"
9 
10 #include <linux/atomic.h>
11 #include <linux/bitops.h>
12 #include <linux/bug.h>
13 #include <linux/byteorder/generic.h>
14 #include <linux/container_of.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/etherdevice.h>
18 #include <linux/gfp.h>
19 #include <linux/icmpv6.h>
20 #include <linux/if_bridge.h>
21 #include <linux/if_ether.h>
22 #include <linux/igmp.h>
23 #include <linux/in.h>
24 #include <linux/in6.h>
25 #include <linux/inetdevice.h>
26 #include <linux/ip.h>
27 #include <linux/ipv6.h>
28 #include <linux/jiffies.h>
29 #include <linux/list.h>
30 #include <linux/lockdep.h>
31 #include <linux/netdevice.h>
32 #include <linux/netlink.h>
33 #include <linux/printk.h>
34 #include <linux/rculist.h>
35 #include <linux/rcupdate.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/spinlock.h>
39 #include <linux/sprintf.h>
40 #include <linux/stddef.h>
41 #include <linux/string.h>
42 #include <linux/types.h>
43 #include <linux/workqueue.h>
44 #include <net/addrconf.h>
45 #include <net/genetlink.h>
46 #include <net/if_inet6.h>
47 #include <net/ip.h>
48 #include <net/ipv6.h>
49 #include <net/netlink.h>
50 #include <uapi/linux/batadv_packet.h>
51 #include <uapi/linux/batman_adv.h>
52 
53 #include "bridge_loop_avoidance.h"
54 #include "hard-interface.h"
55 #include "hash.h"
56 #include "log.h"
57 #include "netlink.h"
58 #include "send.h"
59 #include "translation-table.h"
60 #include "tvlv.h"
61 
62 static void batadv_mcast_mla_update(struct work_struct *work);
63 
64 /**
65  * batadv_mcast_start_timer() - schedule the multicast periodic worker
66  * @bat_priv: the bat priv with all the soft interface information
67  */
68 static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
69 {
70 	queue_delayed_work(batadv_event_workqueue, &bat_priv->mcast.work,
71 			   msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
72 }
73 
74 /**
75  * batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists
76  * @soft_iface: netdev struct of the mesh interface
77  *
78  * If the given soft interface has a bridge on top then the refcount
79  * of the according net device is increased.
80  *
81  * Return: NULL if no such bridge exists. Otherwise the net device of the
82  * bridge.
83  */
84 static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
85 {
86 	struct net_device *upper = soft_iface;
87 
88 	rcu_read_lock();
89 	do {
90 		upper = netdev_master_upper_dev_get_rcu(upper);
91 	} while (upper && !netif_is_bridge_master(upper));
92 
93 	dev_hold(upper);
94 	rcu_read_unlock();
95 
96 	return upper;
97 }
98 
99 /**
100  * batadv_mcast_mla_rtr_flags_softif_get_ipv4() - get mcast router flags from
101  *  node for IPv4
102  * @dev: the interface to check
103  *
104  * Checks the presence of an IPv4 multicast router on this node.
105  *
106  * Caller needs to hold rcu read lock.
107  *
108  * Return: BATADV_NO_FLAGS if present, BATADV_MCAST_WANT_NO_RTR4 otherwise.
109  */
110 static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv4(struct net_device *dev)
111 {
112 	struct in_device *in_dev = __in_dev_get_rcu(dev);
113 
114 	if (in_dev && IN_DEV_MFORWARD(in_dev))
115 		return BATADV_NO_FLAGS;
116 	else
117 		return BATADV_MCAST_WANT_NO_RTR4;
118 }
119 
120 /**
121  * batadv_mcast_mla_rtr_flags_softif_get_ipv6() - get mcast router flags from
122  *  node for IPv6
123  * @dev: the interface to check
124  *
125  * Checks the presence of an IPv6 multicast router on this node.
126  *
127  * Caller needs to hold rcu read lock.
128  *
129  * Return: BATADV_NO_FLAGS if present, BATADV_MCAST_WANT_NO_RTR6 otherwise.
130  */
131 #if IS_ENABLED(CONFIG_IPV6_MROUTE)
132 static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev)
133 {
134 	struct inet6_dev *in6_dev = __in6_dev_get(dev);
135 
136 	if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding))
137 		return BATADV_NO_FLAGS;
138 	else
139 		return BATADV_MCAST_WANT_NO_RTR6;
140 }
141 #else
142 static inline u8
143 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev)
144 {
145 	return BATADV_MCAST_WANT_NO_RTR6;
146 }
147 #endif
148 
149 /**
150  * batadv_mcast_mla_rtr_flags_softif_get() - get mcast router flags from node
151  * @bat_priv: the bat priv with all the soft interface information
152  * @bridge: bridge interface on top of the soft_iface if present,
153  *  otherwise pass NULL
154  *
155  * Checks the presence of IPv4 and IPv6 multicast routers on this
156  * node.
157  *
158  * Return:
159  *	BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
160  *	BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
161  *	BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
162  *	The former two OR'd: no multicast router is present
163  */
164 static u8 batadv_mcast_mla_rtr_flags_softif_get(struct batadv_priv *bat_priv,
165 						struct net_device *bridge)
166 {
167 	struct net_device *dev = bridge ? bridge : bat_priv->soft_iface;
168 	u8 flags = BATADV_NO_FLAGS;
169 
170 	rcu_read_lock();
171 
172 	flags |= batadv_mcast_mla_rtr_flags_softif_get_ipv4(dev);
173 	flags |= batadv_mcast_mla_rtr_flags_softif_get_ipv6(dev);
174 
175 	rcu_read_unlock();
176 
177 	return flags;
178 }
179 
180 /**
181  * batadv_mcast_mla_rtr_flags_bridge_get() - get mcast router flags from bridge
182  * @bat_priv: the bat priv with all the soft interface information
183  * @bridge: bridge interface on top of the soft_iface if present,
184  *  otherwise pass NULL
185  *
186  * Checks the presence of IPv4 and IPv6 multicast routers behind a bridge.
187  *
188  * Return:
189  *	BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
190  *	BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
191  *	BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
192  *	The former two OR'd: no multicast router is present
193  */
194 static u8 batadv_mcast_mla_rtr_flags_bridge_get(struct batadv_priv *bat_priv,
195 						struct net_device *bridge)
196 {
197 	struct net_device *dev = bat_priv->soft_iface;
198 	u8 flags = BATADV_NO_FLAGS;
199 
200 	if (!bridge)
201 		return BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6;
202 
203 	if (!br_multicast_has_router_adjacent(dev, ETH_P_IP))
204 		flags |= BATADV_MCAST_WANT_NO_RTR4;
205 	if (!br_multicast_has_router_adjacent(dev, ETH_P_IPV6))
206 		flags |= BATADV_MCAST_WANT_NO_RTR6;
207 
208 	return flags;
209 }
210 
211 /**
212  * batadv_mcast_mla_rtr_flags_get() - get multicast router flags
213  * @bat_priv: the bat priv with all the soft interface information
214  * @bridge: bridge interface on top of the soft_iface if present,
215  *  otherwise pass NULL
216  *
217  * Checks the presence of IPv4 and IPv6 multicast routers on this
218  * node or behind its bridge.
219  *
220  * Return:
221  *	BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
222  *	BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
223  *	BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
224  *	The former two OR'd: no multicast router is present
225  */
226 static u8 batadv_mcast_mla_rtr_flags_get(struct batadv_priv *bat_priv,
227 					 struct net_device *bridge)
228 {
229 	u8 flags = BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6;
230 
231 	flags &= batadv_mcast_mla_rtr_flags_softif_get(bat_priv, bridge);
232 	flags &= batadv_mcast_mla_rtr_flags_bridge_get(bat_priv, bridge);
233 
234 	return flags;
235 }
236 
237 /**
238  * batadv_mcast_mla_forw_flags_get() - get multicast forwarding flags
239  * @bat_priv: the bat priv with all the soft interface information
240  *
241  * Checks if all active hard interfaces have an MTU larger or equal to 1280
242  * bytes (IPv6 minimum MTU).
243  *
244  * Return: BATADV_MCAST_HAVE_MC_PTYPE_CAPA if yes, BATADV_NO_FLAGS otherwise.
245  */
246 static u8 batadv_mcast_mla_forw_flags_get(struct batadv_priv *bat_priv)
247 {
248 	const struct batadv_hard_iface *hard_iface;
249 
250 	rcu_read_lock();
251 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
252 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
253 			continue;
254 
255 		if (hard_iface->soft_iface != bat_priv->soft_iface)
256 			continue;
257 
258 		if (hard_iface->net_dev->mtu < IPV6_MIN_MTU) {
259 			rcu_read_unlock();
260 			return BATADV_NO_FLAGS;
261 		}
262 	}
263 	rcu_read_unlock();
264 
265 	return BATADV_MCAST_HAVE_MC_PTYPE_CAPA;
266 }
267 
268 /**
269  * batadv_mcast_mla_flags_get() - get the new multicast flags
270  * @bat_priv: the bat priv with all the soft interface information
271  *
272  * Return: A set of flags for the current/next TVLV, querier and
273  * bridge state.
274  */
275 static struct batadv_mcast_mla_flags
276 batadv_mcast_mla_flags_get(struct batadv_priv *bat_priv)
277 {
278 	struct net_device *dev = bat_priv->soft_iface;
279 	struct batadv_mcast_querier_state *qr4, *qr6;
280 	struct batadv_mcast_mla_flags mla_flags;
281 	struct net_device *bridge;
282 
283 	bridge = batadv_mcast_get_bridge(dev);
284 
285 	memset(&mla_flags, 0, sizeof(mla_flags));
286 	mla_flags.enabled = 1;
287 	mla_flags.tvlv_flags |= batadv_mcast_mla_rtr_flags_get(bat_priv,
288 							       bridge);
289 	mla_flags.tvlv_flags |= batadv_mcast_mla_forw_flags_get(bat_priv);
290 
291 	if (!bridge)
292 		return mla_flags;
293 
294 	dev_put(bridge);
295 
296 	mla_flags.bridged = 1;
297 	qr4 = &mla_flags.querier_ipv4;
298 	qr6 = &mla_flags.querier_ipv6;
299 
300 	if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))
301 		pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");
302 
303 	qr4->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);
304 	qr4->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);
305 
306 	qr6->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);
307 	qr6->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);
308 
309 	mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;
310 
311 	/* 1) If no querier exists at all, then multicast listeners on
312 	 *    our local TT clients behind the bridge will keep silent.
313 	 * 2) If the selected querier is on one of our local TT clients,
314 	 *    behind the bridge, then this querier might shadow multicast
315 	 *    listeners on our local TT clients, behind this bridge.
316 	 *
317 	 * In both cases, we will signalize other batman nodes that
318 	 * we need all multicast traffic of the according protocol.
319 	 */
320 	if (!qr4->exists || qr4->shadowing) {
321 		mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV4;
322 		mla_flags.tvlv_flags &= ~BATADV_MCAST_WANT_NO_RTR4;
323 	}
324 
325 	if (!qr6->exists || qr6->shadowing) {
326 		mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV6;
327 		mla_flags.tvlv_flags &= ~BATADV_MCAST_WANT_NO_RTR6;
328 	}
329 
330 	return mla_flags;
331 }
332 
333 /**
334  * batadv_mcast_mla_is_duplicate() - check whether an address is in a list
335  * @mcast_addr: the multicast address to check
336  * @mcast_list: the list with multicast addresses to search in
337  *
338  * Return: true if the given address is already in the given list.
339  * Otherwise returns false.
340  */
341 static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,
342 					  struct hlist_head *mcast_list)
343 {
344 	struct batadv_hw_addr *mcast_entry;
345 
346 	hlist_for_each_entry(mcast_entry, mcast_list, list)
347 		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))
348 			return true;
349 
350 	return false;
351 }
352 
353 /**
354  * batadv_mcast_mla_softif_get_ipv4() - get softif IPv4 multicast listeners
355  * @dev: the device to collect multicast addresses from
356  * @mcast_list: a list to put found addresses into
357  * @flags: flags indicating the new multicast state
358  *
359  * Collects multicast addresses of IPv4 multicast listeners residing
360  * on this kernel on the given soft interface, dev, in
361  * the given mcast_list. In general, multicast listeners provided by
362  * your multicast receiving applications run directly on this node.
363  *
364  * Return: -ENOMEM on memory allocation error or the number of
365  * items added to the mcast_list otherwise.
366  */
367 static int
368 batadv_mcast_mla_softif_get_ipv4(struct net_device *dev,
369 				 struct hlist_head *mcast_list,
370 				 struct batadv_mcast_mla_flags *flags)
371 {
372 	struct batadv_hw_addr *new;
373 	struct in_device *in_dev;
374 	u8 mcast_addr[ETH_ALEN];
375 	struct ip_mc_list *pmc;
376 	int ret = 0;
377 
378 	if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4)
379 		return 0;
380 
381 	rcu_read_lock();
382 
383 	in_dev = __in_dev_get_rcu(dev);
384 	if (!in_dev) {
385 		rcu_read_unlock();
386 		return 0;
387 	}
388 
389 	for (pmc = rcu_dereference(in_dev->mc_list); pmc;
390 	     pmc = rcu_dereference(pmc->next_rcu)) {
391 		if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
392 		    ipv4_is_local_multicast(pmc->multiaddr))
393 			continue;
394 
395 		if (!(flags->tvlv_flags & BATADV_MCAST_WANT_NO_RTR4) &&
396 		    !ipv4_is_local_multicast(pmc->multiaddr))
397 			continue;
398 
399 		ip_eth_mc_map(pmc->multiaddr, mcast_addr);
400 
401 		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
402 			continue;
403 
404 		new = kmalloc(sizeof(*new), GFP_ATOMIC);
405 		if (!new) {
406 			ret = -ENOMEM;
407 			break;
408 		}
409 
410 		ether_addr_copy(new->addr, mcast_addr);
411 		hlist_add_head(&new->list, mcast_list);
412 		ret++;
413 	}
414 	rcu_read_unlock();
415 
416 	return ret;
417 }
418 
419 /**
420  * batadv_mcast_mla_softif_get_ipv6() - get softif IPv6 multicast listeners
421  * @dev: the device to collect multicast addresses from
422  * @mcast_list: a list to put found addresses into
423  * @flags: flags indicating the new multicast state
424  *
425  * Collects multicast addresses of IPv6 multicast listeners residing
426  * on this kernel on the given soft interface, dev, in
427  * the given mcast_list. In general, multicast listeners provided by
428  * your multicast receiving applications run directly on this node.
429  *
430  * Return: -ENOMEM on memory allocation error or the number of
431  * items added to the mcast_list otherwise.
432  */
433 #if IS_ENABLED(CONFIG_IPV6)
434 static int
435 batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,
436 				 struct hlist_head *mcast_list,
437 				 struct batadv_mcast_mla_flags *flags)
438 {
439 	struct batadv_hw_addr *new;
440 	struct inet6_dev *in6_dev;
441 	u8 mcast_addr[ETH_ALEN];
442 	struct ifmcaddr6 *pmc6;
443 	int ret = 0;
444 
445 	if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6)
446 		return 0;
447 
448 	rcu_read_lock();
449 
450 	in6_dev = __in6_dev_get(dev);
451 	if (!in6_dev) {
452 		rcu_read_unlock();
453 		return 0;
454 	}
455 
456 	for (pmc6 = rcu_dereference(in6_dev->mc_list);
457 	     pmc6;
458 	     pmc6 = rcu_dereference(pmc6->next)) {
459 		if (IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) <
460 		    IPV6_ADDR_SCOPE_LINKLOCAL)
461 			continue;
462 
463 		if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
464 		    ipv6_addr_is_ll_all_nodes(&pmc6->mca_addr))
465 			continue;
466 
467 		if (!(flags->tvlv_flags & BATADV_MCAST_WANT_NO_RTR6) &&
468 		    IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) >
469 		    IPV6_ADDR_SCOPE_LINKLOCAL)
470 			continue;
471 
472 		ipv6_eth_mc_map(&pmc6->mca_addr, mcast_addr);
473 
474 		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
475 			continue;
476 
477 		new = kmalloc(sizeof(*new), GFP_ATOMIC);
478 		if (!new) {
479 			ret = -ENOMEM;
480 			break;
481 		}
482 
483 		ether_addr_copy(new->addr, mcast_addr);
484 		hlist_add_head(&new->list, mcast_list);
485 		ret++;
486 	}
487 	rcu_read_unlock();
488 
489 	return ret;
490 }
491 #else
492 static inline int
493 batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,
494 				 struct hlist_head *mcast_list,
495 				 struct batadv_mcast_mla_flags *flags)
496 {
497 	return 0;
498 }
499 #endif
500 
501 /**
502  * batadv_mcast_mla_softif_get() - get softif multicast listeners
503  * @dev: the device to collect multicast addresses from
504  * @mcast_list: a list to put found addresses into
505  * @flags: flags indicating the new multicast state
506  *
507  * Collects multicast addresses of multicast listeners residing
508  * on this kernel on the given soft interface, dev, in
509  * the given mcast_list. In general, multicast listeners provided by
510  * your multicast receiving applications run directly on this node.
511  *
512  * If there is a bridge interface on top of dev, collect from that one
513  * instead. Just like with IP addresses and routes, multicast listeners
514  * will(/should) register to the bridge interface instead of an
515  * enslaved bat0.
516  *
517  * Return: -ENOMEM on memory allocation error or the number of
518  * items added to the mcast_list otherwise.
519  */
520 static int
521 batadv_mcast_mla_softif_get(struct net_device *dev,
522 			    struct hlist_head *mcast_list,
523 			    struct batadv_mcast_mla_flags *flags)
524 {
525 	struct net_device *bridge = batadv_mcast_get_bridge(dev);
526 	int ret4, ret6 = 0;
527 
528 	if (bridge)
529 		dev = bridge;
530 
531 	ret4 = batadv_mcast_mla_softif_get_ipv4(dev, mcast_list, flags);
532 	if (ret4 < 0)
533 		goto out;
534 
535 	ret6 = batadv_mcast_mla_softif_get_ipv6(dev, mcast_list, flags);
536 	if (ret6 < 0) {
537 		ret4 = 0;
538 		goto out;
539 	}
540 
541 out:
542 	dev_put(bridge);
543 
544 	return ret4 + ret6;
545 }
546 
547 /**
548  * batadv_mcast_mla_br_addr_cpy() - copy a bridge multicast address
549  * @dst: destination to write to - a multicast MAC address
550  * @src: source to read from - a multicast IP address
551  *
552  * Converts a given multicast IPv4/IPv6 address from a bridge
553  * to its matching multicast MAC address and copies it into the given
554  * destination buffer.
555  *
556  * Caller needs to make sure the destination buffer can hold
557  * at least ETH_ALEN bytes.
558  */
559 static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
560 {
561 	if (src->proto == htons(ETH_P_IP))
562 		ip_eth_mc_map(src->dst.ip4, dst);
563 #if IS_ENABLED(CONFIG_IPV6)
564 	else if (src->proto == htons(ETH_P_IPV6))
565 		ipv6_eth_mc_map(&src->dst.ip6, dst);
566 #endif
567 	else
568 		eth_zero_addr(dst);
569 }
570 
571 /**
572  * batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners
573  * @dev: a bridge slave whose bridge to collect multicast addresses from
574  * @mcast_list: a list to put found addresses into
575  * @flags: flags indicating the new multicast state
576  *
577  * Collects multicast addresses of multicast listeners residing
578  * on foreign, non-mesh devices which we gave access to our mesh via
579  * a bridge on top of the given soft interface, dev, in the given
580  * mcast_list.
581  *
582  * Return: -ENOMEM on memory allocation error or the number of
583  * items added to the mcast_list otherwise.
584  */
585 static int batadv_mcast_mla_bridge_get(struct net_device *dev,
586 				       struct hlist_head *mcast_list,
587 				       struct batadv_mcast_mla_flags *flags)
588 {
589 	struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
590 	struct br_ip_list *br_ip_entry, *tmp;
591 	u8 tvlv_flags = flags->tvlv_flags;
592 	struct batadv_hw_addr *new;
593 	u8 mcast_addr[ETH_ALEN];
594 	int ret;
595 
596 	/* we don't need to detect these devices/listeners, the IGMP/MLD
597 	 * snooping code of the Linux bridge already does that for us
598 	 */
599 	ret = br_multicast_list_adjacent(dev, &bridge_mcast_list);
600 	if (ret < 0)
601 		goto out;
602 
603 	list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) {
604 		if (br_ip_entry->addr.proto == htons(ETH_P_IP)) {
605 			if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4)
606 				continue;
607 
608 			if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
609 			    ipv4_is_local_multicast(br_ip_entry->addr.dst.ip4))
610 				continue;
611 
612 			if (!(tvlv_flags & BATADV_MCAST_WANT_NO_RTR4) &&
613 			    !ipv4_is_local_multicast(br_ip_entry->addr.dst.ip4))
614 				continue;
615 		}
616 
617 #if IS_ENABLED(CONFIG_IPV6)
618 		if (br_ip_entry->addr.proto == htons(ETH_P_IPV6)) {
619 			if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6)
620 				continue;
621 
622 			if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
623 			    ipv6_addr_is_ll_all_nodes(&br_ip_entry->addr.dst.ip6))
624 				continue;
625 
626 			if (!(tvlv_flags & BATADV_MCAST_WANT_NO_RTR6) &&
627 			    IPV6_ADDR_MC_SCOPE(&br_ip_entry->addr.dst.ip6) >
628 			    IPV6_ADDR_SCOPE_LINKLOCAL)
629 				continue;
630 		}
631 #endif
632 
633 		batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr);
634 		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
635 			continue;
636 
637 		new = kmalloc(sizeof(*new), GFP_ATOMIC);
638 		if (!new) {
639 			ret = -ENOMEM;
640 			break;
641 		}
642 
643 		ether_addr_copy(new->addr, mcast_addr);
644 		hlist_add_head(&new->list, mcast_list);
645 	}
646 
647 out:
648 	list_for_each_entry_safe(br_ip_entry, tmp, &bridge_mcast_list, list) {
649 		list_del(&br_ip_entry->list);
650 		kfree(br_ip_entry);
651 	}
652 
653 	return ret;
654 }
655 
656 /**
657  * batadv_mcast_mla_list_free() - free a list of multicast addresses
658  * @mcast_list: the list to free
659  *
660  * Removes and frees all items in the given mcast_list.
661  */
662 static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)
663 {
664 	struct batadv_hw_addr *mcast_entry;
665 	struct hlist_node *tmp;
666 
667 	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
668 		hlist_del(&mcast_entry->list);
669 		kfree(mcast_entry);
670 	}
671 }
672 
673 /**
674  * batadv_mcast_mla_tt_retract() - clean up multicast listener announcements
675  * @bat_priv: the bat priv with all the soft interface information
676  * @mcast_list: a list of addresses which should _not_ be removed
677  *
678  * Retracts the announcement of any multicast listener from the
679  * translation table except the ones listed in the given mcast_list.
680  *
681  * If mcast_list is NULL then all are retracted.
682  */
683 static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
684 					struct hlist_head *mcast_list)
685 {
686 	struct batadv_hw_addr *mcast_entry;
687 	struct hlist_node *tmp;
688 
689 	hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
690 				  list) {
691 		if (mcast_list &&
692 		    batadv_mcast_mla_is_duplicate(mcast_entry->addr,
693 						  mcast_list))
694 			continue;
695 
696 		batadv_tt_local_remove(bat_priv, mcast_entry->addr,
697 				       BATADV_NO_FLAGS,
698 				       "mcast TT outdated", false);
699 
700 		hlist_del(&mcast_entry->list);
701 		kfree(mcast_entry);
702 	}
703 }
704 
705 /**
706  * batadv_mcast_mla_tt_add() - add multicast listener announcements
707  * @bat_priv: the bat priv with all the soft interface information
708  * @mcast_list: a list of addresses which are going to get added
709  *
710  * Adds multicast listener announcements from the given mcast_list to the
711  * translation table if they have not been added yet.
712  */
713 static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
714 				    struct hlist_head *mcast_list)
715 {
716 	struct batadv_hw_addr *mcast_entry;
717 	struct hlist_node *tmp;
718 
719 	if (!mcast_list)
720 		return;
721 
722 	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
723 		if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,
724 						  &bat_priv->mcast.mla_list))
725 			continue;
726 
727 		if (!batadv_tt_local_add(bat_priv->soft_iface,
728 					 mcast_entry->addr, BATADV_NO_FLAGS,
729 					 BATADV_NULL_IFINDEX, BATADV_NO_MARK))
730 			continue;
731 
732 		hlist_del(&mcast_entry->list);
733 		hlist_add_head(&mcast_entry->list, &bat_priv->mcast.mla_list);
734 	}
735 }
736 
737 /**
738  * batadv_mcast_querier_log() - debug output regarding the querier status on
739  *  link
740  * @bat_priv: the bat priv with all the soft interface information
741  * @str_proto: a string for the querier protocol (e.g. "IGMP" or "MLD")
742  * @old_state: the previous querier state on our link
743  * @new_state: the new querier state on our link
744  *
745  * Outputs debug messages to the logging facility with log level 'mcast'
746  * regarding changes to the querier status on the link which are relevant
747  * to our multicast optimizations.
748  *
749  * Usually this is about whether a querier appeared or vanished in
750  * our mesh or whether the querier is in the suboptimal position of being
751  * behind our local bridge segment: Snooping switches will directly
752  * forward listener reports to the querier, therefore batman-adv and
753  * the bridge will potentially not see these listeners - the querier is
754  * potentially shadowing listeners from us then.
755  *
756  * This is only interesting for nodes with a bridge on top of their
757  * soft interface.
758  */
759 static void
760 batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto,
761 			 struct batadv_mcast_querier_state *old_state,
762 			 struct batadv_mcast_querier_state *new_state)
763 {
764 	if (!old_state->exists && new_state->exists)
765 		batadv_info(bat_priv->soft_iface, "%s Querier appeared\n",
766 			    str_proto);
767 	else if (old_state->exists && !new_state->exists)
768 		batadv_info(bat_priv->soft_iface,
769 			    "%s Querier disappeared - multicast optimizations disabled\n",
770 			    str_proto);
771 	else if (!bat_priv->mcast.mla_flags.bridged && !new_state->exists)
772 		batadv_info(bat_priv->soft_iface,
773 			    "No %s Querier present - multicast optimizations disabled\n",
774 			    str_proto);
775 
776 	if (new_state->exists) {
777 		if ((!old_state->shadowing && new_state->shadowing) ||
778 		    (!old_state->exists && new_state->shadowing))
779 			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
780 				   "%s Querier is behind our bridged segment: Might shadow listeners\n",
781 				   str_proto);
782 		else if (old_state->shadowing && !new_state->shadowing)
783 			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
784 				   "%s Querier is not behind our bridged segment\n",
785 				   str_proto);
786 	}
787 }
788 
789 /**
790  * batadv_mcast_bridge_log() - debug output for topology changes in bridged
791  *  setups
792  * @bat_priv: the bat priv with all the soft interface information
793  * @new_flags: flags indicating the new multicast state
794  *
795  * If no bridges are ever used on this node, then this function does nothing.
796  *
797  * Otherwise this function outputs debug information to the 'mcast' log level
798  * which might be relevant to our multicast optimizations.
799  *
800  * More precisely, it outputs information when a bridge interface is added or
801  * removed from a soft interface. And when a bridge is present, it further
802  * outputs information about the querier state which is relevant for the
803  * multicast flags this node is going to set.
804  */
805 static void
806 batadv_mcast_bridge_log(struct batadv_priv *bat_priv,
807 			struct batadv_mcast_mla_flags *new_flags)
808 {
809 	struct batadv_mcast_mla_flags *old_flags = &bat_priv->mcast.mla_flags;
810 
811 	if (!old_flags->bridged && new_flags->bridged)
812 		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
813 			   "Bridge added: Setting Unsnoopables(U)-flag\n");
814 	else if (old_flags->bridged && !new_flags->bridged)
815 		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
816 			   "Bridge removed: Unsetting Unsnoopables(U)-flag\n");
817 
818 	if (new_flags->bridged) {
819 		batadv_mcast_querier_log(bat_priv, "IGMP",
820 					 &old_flags->querier_ipv4,
821 					 &new_flags->querier_ipv4);
822 		batadv_mcast_querier_log(bat_priv, "MLD",
823 					 &old_flags->querier_ipv6,
824 					 &new_flags->querier_ipv6);
825 	}
826 }
827 
828 /**
829  * batadv_mcast_flags_log() - output debug information about mcast flag changes
830  * @bat_priv: the bat priv with all the soft interface information
831  * @flags: TVLV flags indicating the new multicast state
832  *
833  * Whenever the multicast TVLV flags this node announces change, this function
834  * should be used to notify userspace about the change.
835  */
836 static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)
837 {
838 	bool old_enabled = bat_priv->mcast.mla_flags.enabled;
839 	u8 old_flags = bat_priv->mcast.mla_flags.tvlv_flags;
840 	char str_old_flags[] = "[.... . .]";
841 
842 	sprintf(str_old_flags, "[%c%c%c%s%s%c]",
843 		(old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
844 		(old_flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
845 		(old_flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.',
846 		!(old_flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",
847 		!(old_flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ",
848 		!(old_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) ? 'P' : '.');
849 
850 	batadv_dbg(BATADV_DBG_MCAST, bat_priv,
851 		   "Changing multicast flags from '%s' to '[%c%c%c%s%s%c]'\n",
852 		   old_enabled ? str_old_flags : "<undefined>",
853 		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
854 		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
855 		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.',
856 		   !(flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",
857 		   !(flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ",
858 		   !(flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) ? 'P' : '.');
859 }
860 
861 /**
862  * batadv_mcast_mla_flags_update() - update multicast flags
863  * @bat_priv: the bat priv with all the soft interface information
864  * @flags: flags indicating the new multicast state
865  *
866  * Updates the own multicast tvlv with our current multicast related settings,
867  * capabilities and inabilities.
868  */
869 static void
870 batadv_mcast_mla_flags_update(struct batadv_priv *bat_priv,
871 			      struct batadv_mcast_mla_flags *flags)
872 {
873 	struct batadv_tvlv_mcast_data mcast_data;
874 
875 	if (!memcmp(flags, &bat_priv->mcast.mla_flags, sizeof(*flags)))
876 		return;
877 
878 	batadv_mcast_bridge_log(bat_priv, flags);
879 	batadv_mcast_flags_log(bat_priv, flags->tvlv_flags);
880 
881 	mcast_data.flags = flags->tvlv_flags;
882 	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
883 
884 	batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,
885 				       &mcast_data, sizeof(mcast_data));
886 
887 	bat_priv->mcast.mla_flags = *flags;
888 }
889 
890 /**
891  * __batadv_mcast_mla_update() - update the own MLAs
892  * @bat_priv: the bat priv with all the soft interface information
893  *
894  * Updates the own multicast listener announcements in the translation
895  * table as well as the own, announced multicast tvlv container.
896  *
897  * Note that non-conflicting reads and writes to bat_priv->mcast.mla_list
898  * in batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add() are
899  * ensured by the non-parallel execution of the worker this function
900  * belongs to.
901  */
902 static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv)
903 {
904 	struct net_device *soft_iface = bat_priv->soft_iface;
905 	struct hlist_head mcast_list = HLIST_HEAD_INIT;
906 	struct batadv_mcast_mla_flags flags;
907 	int ret;
908 
909 	flags = batadv_mcast_mla_flags_get(bat_priv);
910 
911 	ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list, &flags);
912 	if (ret < 0)
913 		goto out;
914 
915 	ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list, &flags);
916 	if (ret < 0)
917 		goto out;
918 
919 	spin_lock(&bat_priv->mcast.mla_lock);
920 	batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);
921 	batadv_mcast_mla_tt_add(bat_priv, &mcast_list);
922 	batadv_mcast_mla_flags_update(bat_priv, &flags);
923 	spin_unlock(&bat_priv->mcast.mla_lock);
924 
925 out:
926 	batadv_mcast_mla_list_free(&mcast_list);
927 }
928 
929 /**
930  * batadv_mcast_mla_update() - update the own MLAs
931  * @work: kernel work struct
932  *
933  * Updates the own multicast listener announcements in the translation
934  * table as well as the own, announced multicast tvlv container.
935  *
936  * In the end, reschedules the work timer.
937  */
938 static void batadv_mcast_mla_update(struct work_struct *work)
939 {
940 	struct delayed_work *delayed_work;
941 	struct batadv_priv_mcast *priv_mcast;
942 	struct batadv_priv *bat_priv;
943 
944 	delayed_work = to_delayed_work(work);
945 	priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);
946 	bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);
947 
948 	__batadv_mcast_mla_update(bat_priv);
949 	batadv_mcast_start_timer(bat_priv);
950 }
951 
952 /**
953  * batadv_mcast_is_report_ipv4() - check for IGMP reports
954  * @skb: the ethernet frame destined for the mesh
955  *
956  * This call might reallocate skb data.
957  *
958  * Checks whether the given frame is a valid IGMP report.
959  *
960  * Return: If so then true, otherwise false.
961  */
962 static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
963 {
964 	if (ip_mc_check_igmp(skb) < 0)
965 		return false;
966 
967 	switch (igmp_hdr(skb)->type) {
968 	case IGMP_HOST_MEMBERSHIP_REPORT:
969 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
970 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
971 		return true;
972 	}
973 
974 	return false;
975 }
976 
977 /**
978  * batadv_mcast_forw_mode_check_ipv4() - check for optimized forwarding
979  *  potential
980  * @bat_priv: the bat priv with all the soft interface information
981  * @skb: the IPv4 packet to check
982  * @is_unsnoopable: stores whether the destination is snoopable
983  * @is_routable: stores whether the destination is routable
984  *
985  * Checks whether the given IPv4 packet has the potential to be forwarded with a
986  * mode more optimal than classic flooding.
987  *
988  * Return: If so then 0. Otherwise -EINVAL or -ENOMEM in case of memory
989  * allocation failure.
990  */
991 static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
992 					     struct sk_buff *skb,
993 					     bool *is_unsnoopable,
994 					     int *is_routable)
995 {
996 	struct iphdr *iphdr;
997 
998 	/* We might fail due to out-of-memory -> drop it */
999 	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*iphdr)))
1000 		return -ENOMEM;
1001 
1002 	if (batadv_mcast_is_report_ipv4(skb))
1003 		return -EINVAL;
1004 
1005 	iphdr = ip_hdr(skb);
1006 
1007 	/* link-local multicast listeners behind a bridge are
1008 	 * not snoopable (see RFC4541, section 2.1.2.2)
1009 	 */
1010 	if (ipv4_is_local_multicast(iphdr->daddr))
1011 		*is_unsnoopable = true;
1012 	else
1013 		*is_routable = ETH_P_IP;
1014 
1015 	return 0;
1016 }
1017 
1018 /**
1019  * batadv_mcast_is_report_ipv6() - check for MLD reports
1020  * @skb: the ethernet frame destined for the mesh
1021  *
1022  * This call might reallocate skb data.
1023  *
1024  * Checks whether the given frame is a valid MLD report.
1025  *
1026  * Return: If so then true, otherwise false.
1027  */
1028 static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb)
1029 {
1030 	if (ipv6_mc_check_mld(skb) < 0)
1031 		return false;
1032 
1033 	switch (icmp6_hdr(skb)->icmp6_type) {
1034 	case ICMPV6_MGM_REPORT:
1035 	case ICMPV6_MLD2_REPORT:
1036 		return true;
1037 	}
1038 
1039 	return false;
1040 }
1041 
1042 /**
1043  * batadv_mcast_forw_mode_check_ipv6() - check for optimized forwarding
1044  *  potential
1045  * @bat_priv: the bat priv with all the soft interface information
1046  * @skb: the IPv6 packet to check
1047  * @is_unsnoopable: stores whether the destination is snoopable
1048  * @is_routable: stores whether the destination is routable
1049  *
1050  * Checks whether the given IPv6 packet has the potential to be forwarded with a
1051  * mode more optimal than classic flooding.
1052  *
1053  * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
1054  */
1055 static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
1056 					     struct sk_buff *skb,
1057 					     bool *is_unsnoopable,
1058 					     int *is_routable)
1059 {
1060 	struct ipv6hdr *ip6hdr;
1061 
1062 	/* We might fail due to out-of-memory -> drop it */
1063 	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr)))
1064 		return -ENOMEM;
1065 
1066 	if (batadv_mcast_is_report_ipv6(skb))
1067 		return -EINVAL;
1068 
1069 	ip6hdr = ipv6_hdr(skb);
1070 
1071 	if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) < IPV6_ADDR_SCOPE_LINKLOCAL)
1072 		return -EINVAL;
1073 
1074 	/* link-local-all-nodes multicast listeners behind a bridge are
1075 	 * not snoopable (see RFC4541, section 3, paragraph 3)
1076 	 */
1077 	if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr))
1078 		*is_unsnoopable = true;
1079 	else if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) > IPV6_ADDR_SCOPE_LINKLOCAL)
1080 		*is_routable = ETH_P_IPV6;
1081 
1082 	return 0;
1083 }
1084 
1085 /**
1086  * batadv_mcast_forw_mode_check() - check for optimized forwarding potential
1087  * @bat_priv: the bat priv with all the soft interface information
1088  * @skb: the multicast frame to check
1089  * @is_unsnoopable: stores whether the destination is snoopable
1090  * @is_routable: stores whether the destination is routable
1091  *
1092  * Checks whether the given multicast ethernet frame has the potential to be
1093  * forwarded with a mode more optimal than classic flooding.
1094  *
1095  * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
1096  */
1097 static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
1098 					struct sk_buff *skb,
1099 					bool *is_unsnoopable,
1100 					int *is_routable)
1101 {
1102 	struct ethhdr *ethhdr = eth_hdr(skb);
1103 
1104 	if (!atomic_read(&bat_priv->multicast_mode))
1105 		return -EINVAL;
1106 
1107 	switch (ntohs(ethhdr->h_proto)) {
1108 	case ETH_P_IP:
1109 		return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb,
1110 							 is_unsnoopable,
1111 							 is_routable);
1112 	case ETH_P_IPV6:
1113 		if (!IS_ENABLED(CONFIG_IPV6))
1114 			return -EINVAL;
1115 
1116 		return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb,
1117 							 is_unsnoopable,
1118 							 is_routable);
1119 	default:
1120 		return -EINVAL;
1121 	}
1122 }
1123 
1124 /**
1125  * batadv_mcast_forw_want_all_ip_count() - count nodes with unspecific mcast
1126  *  interest
1127  * @bat_priv: the bat priv with all the soft interface information
1128  * @ethhdr: ethernet header of a packet
1129  *
1130  * Return: the number of nodes which want all IPv4 multicast traffic if the
1131  * given ethhdr is from an IPv4 packet or the number of nodes which want all
1132  * IPv6 traffic if it matches an IPv6 packet.
1133  */
1134 static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv,
1135 					       struct ethhdr *ethhdr)
1136 {
1137 	switch (ntohs(ethhdr->h_proto)) {
1138 	case ETH_P_IP:
1139 		return atomic_read(&bat_priv->mcast.num_want_all_ipv4);
1140 	case ETH_P_IPV6:
1141 		return atomic_read(&bat_priv->mcast.num_want_all_ipv6);
1142 	default:
1143 		/* we shouldn't be here... */
1144 		return 0;
1145 	}
1146 }
1147 
1148 /**
1149  * batadv_mcast_forw_rtr_count() - count nodes with a multicast router
1150  * @bat_priv: the bat priv with all the soft interface information
1151  * @protocol: the ethernet protocol type to count multicast routers for
1152  *
1153  * Return: the number of nodes which want all routable IPv4 multicast traffic
1154  * if the protocol is ETH_P_IP or the number of nodes which want all routable
1155  * IPv6 traffic if the protocol is ETH_P_IPV6. Otherwise returns 0.
1156  */
1157 
1158 static int batadv_mcast_forw_rtr_count(struct batadv_priv *bat_priv,
1159 				       int protocol)
1160 {
1161 	switch (protocol) {
1162 	case ETH_P_IP:
1163 		return atomic_read(&bat_priv->mcast.num_want_all_rtr4);
1164 	case ETH_P_IPV6:
1165 		return atomic_read(&bat_priv->mcast.num_want_all_rtr6);
1166 	default:
1167 		return 0;
1168 	}
1169 }
1170 
1171 /**
1172  * batadv_mcast_forw_mode_by_count() - get forwarding mode by count
1173  * @bat_priv: the bat priv with all the soft interface information
1174  * @skb: the multicast packet to check
1175  * @vid: the vlan identifier
1176  * @is_routable: stores whether the destination is routable
1177  * @count: the number of originators the multicast packet need to be sent to
1178  *
1179  * For a multicast packet with multiple destination originators, checks which
1180  * mode to use. For BATADV_FORW_MCAST it also encapsulates the packet with a
1181  * complete batman-adv multicast header.
1182  *
1183  * Return:
1184  *	BATADV_FORW_MCAST: If all nodes have multicast packet routing
1185  *	capabilities and an MTU >= 1280 on all hard interfaces (including us)
1186  *	and the encapsulated multicast packet with all destination addresses
1187  *	would still fit into an 1280 bytes batman-adv multicast packet
1188  *	(excluding the outer ethernet frame) and we could successfully push
1189  *	the full batman-adv multicast packet header.
1190  *	BATADV_FORW_UCASTS: If the packet cannot be sent in a batman-adv
1191  *	multicast packet and the amount of batman-adv unicast packets needed
1192  *	is smaller or equal to the configured multicast fanout.
1193  *	BATADV_FORW_BCAST: Otherwise.
1194  */
1195 static enum batadv_forw_mode
1196 batadv_mcast_forw_mode_by_count(struct batadv_priv *bat_priv,
1197 				struct sk_buff *skb, unsigned short vid,
1198 				int is_routable, int count)
1199 {
1200 	unsigned int mcast_hdrlen = batadv_mcast_forw_packet_hdrlen(count);
1201 	u8 own_tvlv_flags = bat_priv->mcast.mla_flags.tvlv_flags;
1202 
1203 	if (!atomic_read(&bat_priv->mcast.num_no_mc_ptype_capa) &&
1204 	    own_tvlv_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
1205 	    skb->len + mcast_hdrlen <= IPV6_MIN_MTU &&
1206 	    batadv_mcast_forw_push(bat_priv, skb, vid, is_routable, count))
1207 		return BATADV_FORW_MCAST;
1208 
1209 	if (count <= atomic_read(&bat_priv->multicast_fanout))
1210 		return BATADV_FORW_UCASTS;
1211 
1212 	return BATADV_FORW_BCAST;
1213 }
1214 
1215 /**
1216  * batadv_mcast_forw_mode() - check on how to forward a multicast packet
1217  * @bat_priv: the bat priv with all the soft interface information
1218  * @skb: the multicast packet to check
1219  * @vid: the vlan identifier
1220  * @is_routable: stores whether the destination is routable
1221  *
1222  * Return: The forwarding mode as enum batadv_forw_mode.
1223  */
1224 enum batadv_forw_mode
1225 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
1226 		       unsigned short vid, int *is_routable)
1227 {
1228 	int ret, tt_count, ip_count, unsnoop_count, total_count;
1229 	bool is_unsnoopable = false;
1230 	struct ethhdr *ethhdr;
1231 	int rtr_count = 0;
1232 
1233 	ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable,
1234 					   is_routable);
1235 	if (ret == -ENOMEM)
1236 		return BATADV_FORW_NONE;
1237 	else if (ret < 0)
1238 		return BATADV_FORW_BCAST;
1239 
1240 	ethhdr = eth_hdr(skb);
1241 
1242 	tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest,
1243 					       BATADV_NO_FLAGS);
1244 	ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr);
1245 	unsnoop_count = !is_unsnoopable ? 0 :
1246 			atomic_read(&bat_priv->mcast.num_want_all_unsnoopables);
1247 	rtr_count = batadv_mcast_forw_rtr_count(bat_priv, *is_routable);
1248 
1249 	total_count = tt_count + ip_count + unsnoop_count + rtr_count;
1250 
1251 	if (!total_count)
1252 		return BATADV_FORW_NONE;
1253 	else if (unsnoop_count)
1254 		return BATADV_FORW_BCAST;
1255 
1256 	return batadv_mcast_forw_mode_by_count(bat_priv, skb, vid, *is_routable,
1257 					       total_count);
1258 }
1259 
1260 /**
1261  * batadv_mcast_forw_send_orig() - send a multicast packet to an originator
1262  * @bat_priv: the bat priv with all the soft interface information
1263  * @skb: the multicast packet to send
1264  * @vid: the vlan identifier
1265  * @orig_node: the originator to send the packet to
1266  *
1267  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
1268  */
1269 static int batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
1270 				       struct sk_buff *skb,
1271 				       unsigned short vid,
1272 				       struct batadv_orig_node *orig_node)
1273 {
1274 	/* Avoid sending multicast-in-unicast packets to other BLA
1275 	 * gateways - they already got the frame from the LAN side
1276 	 * we share with them.
1277 	 * TODO: Refactor to take BLA into account earlier, to avoid
1278 	 * reducing the mcast_fanout count.
1279 	 */
1280 	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid)) {
1281 		dev_kfree_skb(skb);
1282 		return NET_XMIT_SUCCESS;
1283 	}
1284 
1285 	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
1286 				       orig_node, vid);
1287 }
1288 
1289 /**
1290  * batadv_mcast_forw_tt() - forwards a packet to multicast listeners
1291  * @bat_priv: the bat priv with all the soft interface information
1292  * @skb: the multicast packet to transmit
1293  * @vid: the vlan identifier
1294  *
1295  * Sends copies of a frame with multicast destination to any multicast
1296  * listener registered in the translation table. A transmission is performed
1297  * via a batman-adv unicast packet for each such destination node.
1298  *
1299  * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
1300  * otherwise.
1301  */
1302 static int
1303 batadv_mcast_forw_tt(struct batadv_priv *bat_priv, struct sk_buff *skb,
1304 		     unsigned short vid)
1305 {
1306 	int ret = NET_XMIT_SUCCESS;
1307 	struct sk_buff *newskb;
1308 
1309 	struct batadv_tt_orig_list_entry *orig_entry;
1310 
1311 	struct batadv_tt_global_entry *tt_global;
1312 	const u8 *addr = eth_hdr(skb)->h_dest;
1313 
1314 	tt_global = batadv_tt_global_hash_find(bat_priv, addr, vid);
1315 	if (!tt_global)
1316 		goto out;
1317 
1318 	rcu_read_lock();
1319 	hlist_for_each_entry_rcu(orig_entry, &tt_global->orig_list, list) {
1320 		newskb = skb_copy(skb, GFP_ATOMIC);
1321 		if (!newskb) {
1322 			ret = NET_XMIT_DROP;
1323 			break;
1324 		}
1325 
1326 		batadv_mcast_forw_send_orig(bat_priv, newskb, vid,
1327 					    orig_entry->orig_node);
1328 	}
1329 	rcu_read_unlock();
1330 
1331 	batadv_tt_global_entry_put(tt_global);
1332 
1333 out:
1334 	return ret;
1335 }
1336 
1337 /**
1338  * batadv_mcast_forw_want_all_ipv4() - forward to nodes with want-all-ipv4
1339  * @bat_priv: the bat priv with all the soft interface information
1340  * @skb: the multicast packet to transmit
1341  * @vid: the vlan identifier
1342  *
1343  * Sends copies of a frame with multicast destination to any node with a
1344  * BATADV_MCAST_WANT_ALL_IPV4 flag set. A transmission is performed via a
1345  * batman-adv unicast packet for each such destination node.
1346  *
1347  * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
1348  * otherwise.
1349  */
1350 static int
1351 batadv_mcast_forw_want_all_ipv4(struct batadv_priv *bat_priv,
1352 				struct sk_buff *skb, unsigned short vid)
1353 {
1354 	struct batadv_orig_node *orig_node;
1355 	int ret = NET_XMIT_SUCCESS;
1356 	struct sk_buff *newskb;
1357 
1358 	rcu_read_lock();
1359 	hlist_for_each_entry_rcu(orig_node,
1360 				 &bat_priv->mcast.want_all_ipv4_list,
1361 				 mcast_want_all_ipv4_node) {
1362 		newskb = skb_copy(skb, GFP_ATOMIC);
1363 		if (!newskb) {
1364 			ret = NET_XMIT_DROP;
1365 			break;
1366 		}
1367 
1368 		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
1369 	}
1370 	rcu_read_unlock();
1371 	return ret;
1372 }
1373 
1374 /**
1375  * batadv_mcast_forw_want_all_ipv6() - forward to nodes with want-all-ipv6
1376  * @bat_priv: the bat priv with all the soft interface information
1377  * @skb: The multicast packet to transmit
1378  * @vid: the vlan identifier
1379  *
1380  * Sends copies of a frame with multicast destination to any node with a
1381  * BATADV_MCAST_WANT_ALL_IPV6 flag set. A transmission is performed via a
1382  * batman-adv unicast packet for each such destination node.
1383  *
1384  * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
1385  * otherwise.
1386  */
1387 static int
1388 batadv_mcast_forw_want_all_ipv6(struct batadv_priv *bat_priv,
1389 				struct sk_buff *skb, unsigned short vid)
1390 {
1391 	struct batadv_orig_node *orig_node;
1392 	int ret = NET_XMIT_SUCCESS;
1393 	struct sk_buff *newskb;
1394 
1395 	rcu_read_lock();
1396 	hlist_for_each_entry_rcu(orig_node,
1397 				 &bat_priv->mcast.want_all_ipv6_list,
1398 				 mcast_want_all_ipv6_node) {
1399 		newskb = skb_copy(skb, GFP_ATOMIC);
1400 		if (!newskb) {
1401 			ret = NET_XMIT_DROP;
1402 			break;
1403 		}
1404 
1405 		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
1406 	}
1407 	rcu_read_unlock();
1408 	return ret;
1409 }
1410 
1411 /**
1412  * batadv_mcast_forw_want_all() - forward packet to nodes in a want-all list
1413  * @bat_priv: the bat priv with all the soft interface information
1414  * @skb: the multicast packet to transmit
1415  * @vid: the vlan identifier
1416  *
1417  * Sends copies of a frame with multicast destination to any node with a
1418  * BATADV_MCAST_WANT_ALL_IPV4 or BATADV_MCAST_WANT_ALL_IPV6 flag set. A
1419  * transmission is performed via a batman-adv unicast packet for each such
1420  * destination node.
1421  *
1422  * Return: NET_XMIT_DROP on memory allocation failure or if the protocol family
1423  * is neither IPv4 nor IPv6. NET_XMIT_SUCCESS otherwise.
1424  */
1425 static int
1426 batadv_mcast_forw_want_all(struct batadv_priv *bat_priv,
1427 			   struct sk_buff *skb, unsigned short vid)
1428 {
1429 	switch (ntohs(eth_hdr(skb)->h_proto)) {
1430 	case ETH_P_IP:
1431 		return batadv_mcast_forw_want_all_ipv4(bat_priv, skb, vid);
1432 	case ETH_P_IPV6:
1433 		return batadv_mcast_forw_want_all_ipv6(bat_priv, skb, vid);
1434 	default:
1435 		/* we shouldn't be here... */
1436 		return NET_XMIT_DROP;
1437 	}
1438 }
1439 
1440 /**
1441  * batadv_mcast_forw_want_all_rtr4() - forward to nodes with want-all-rtr4
1442  * @bat_priv: the bat priv with all the soft interface information
1443  * @skb: the multicast packet to transmit
1444  * @vid: the vlan identifier
1445  *
1446  * Sends copies of a frame with multicast destination to any node with a
1447  * BATADV_MCAST_WANT_NO_RTR4 flag unset. A transmission is performed via a
1448  * batman-adv unicast packet for each such destination node.
1449  *
1450  * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
1451  * otherwise.
1452  */
1453 static int
1454 batadv_mcast_forw_want_all_rtr4(struct batadv_priv *bat_priv,
1455 				struct sk_buff *skb, unsigned short vid)
1456 {
1457 	struct batadv_orig_node *orig_node;
1458 	int ret = NET_XMIT_SUCCESS;
1459 	struct sk_buff *newskb;
1460 
1461 	rcu_read_lock();
1462 	hlist_for_each_entry_rcu(orig_node,
1463 				 &bat_priv->mcast.want_all_rtr4_list,
1464 				 mcast_want_all_rtr4_node) {
1465 		newskb = skb_copy(skb, GFP_ATOMIC);
1466 		if (!newskb) {
1467 			ret = NET_XMIT_DROP;
1468 			break;
1469 		}
1470 
1471 		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
1472 	}
1473 	rcu_read_unlock();
1474 	return ret;
1475 }
1476 
1477 /**
1478  * batadv_mcast_forw_want_all_rtr6() - forward to nodes with want-all-rtr6
1479  * @bat_priv: the bat priv with all the soft interface information
1480  * @skb: The multicast packet to transmit
1481  * @vid: the vlan identifier
1482  *
1483  * Sends copies of a frame with multicast destination to any node with a
1484  * BATADV_MCAST_WANT_NO_RTR6 flag unset. A transmission is performed via a
1485  * batman-adv unicast packet for each such destination node.
1486  *
1487  * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
1488  * otherwise.
1489  */
1490 static int
1491 batadv_mcast_forw_want_all_rtr6(struct batadv_priv *bat_priv,
1492 				struct sk_buff *skb, unsigned short vid)
1493 {
1494 	struct batadv_orig_node *orig_node;
1495 	int ret = NET_XMIT_SUCCESS;
1496 	struct sk_buff *newskb;
1497 
1498 	rcu_read_lock();
1499 	hlist_for_each_entry_rcu(orig_node,
1500 				 &bat_priv->mcast.want_all_rtr6_list,
1501 				 mcast_want_all_rtr6_node) {
1502 		newskb = skb_copy(skb, GFP_ATOMIC);
1503 		if (!newskb) {
1504 			ret = NET_XMIT_DROP;
1505 			break;
1506 		}
1507 
1508 		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
1509 	}
1510 	rcu_read_unlock();
1511 	return ret;
1512 }
1513 
1514 /**
1515  * batadv_mcast_forw_want_rtr() - forward packet to nodes in a want-all-rtr list
1516  * @bat_priv: the bat priv with all the soft interface information
1517  * @skb: the multicast packet to transmit
1518  * @vid: the vlan identifier
1519  *
1520  * Sends copies of a frame with multicast destination to any node with a
1521  * BATADV_MCAST_WANT_NO_RTR4 or BATADV_MCAST_WANT_NO_RTR6 flag unset. A
1522  * transmission is performed via a batman-adv unicast packet for each such
1523  * destination node.
1524  *
1525  * Return: NET_XMIT_DROP on memory allocation failure or if the protocol family
1526  * is neither IPv4 nor IPv6. NET_XMIT_SUCCESS otherwise.
1527  */
1528 static int
1529 batadv_mcast_forw_want_rtr(struct batadv_priv *bat_priv,
1530 			   struct sk_buff *skb, unsigned short vid)
1531 {
1532 	switch (ntohs(eth_hdr(skb)->h_proto)) {
1533 	case ETH_P_IP:
1534 		return batadv_mcast_forw_want_all_rtr4(bat_priv, skb, vid);
1535 	case ETH_P_IPV6:
1536 		return batadv_mcast_forw_want_all_rtr6(bat_priv, skb, vid);
1537 	default:
1538 		/* we shouldn't be here... */
1539 		return NET_XMIT_DROP;
1540 	}
1541 }
1542 
1543 /**
1544  * batadv_mcast_forw_send() - send packet to any detected multicast recipient
1545  * @bat_priv: the bat priv with all the soft interface information
1546  * @skb: the multicast packet to transmit
1547  * @vid: the vlan identifier
1548  * @is_routable: stores whether the destination is routable
1549  *
1550  * Sends copies of a frame with multicast destination to any node that signaled
1551  * interest in it, that is either via the translation table or the according
1552  * want-all flags. A transmission is performed via a batman-adv unicast packet
1553  * for each such destination node.
1554  *
1555  * The given skb is consumed/freed.
1556  *
1557  * Return: NET_XMIT_DROP on memory allocation failure or if the protocol family
1558  * is neither IPv4 nor IPv6. NET_XMIT_SUCCESS otherwise.
1559  */
1560 int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
1561 			   unsigned short vid, int is_routable)
1562 {
1563 	int ret;
1564 
1565 	ret = batadv_mcast_forw_tt(bat_priv, skb, vid);
1566 	if (ret != NET_XMIT_SUCCESS) {
1567 		kfree_skb(skb);
1568 		return ret;
1569 	}
1570 
1571 	ret = batadv_mcast_forw_want_all(bat_priv, skb, vid);
1572 	if (ret != NET_XMIT_SUCCESS) {
1573 		kfree_skb(skb);
1574 		return ret;
1575 	}
1576 
1577 	if (!is_routable)
1578 		goto skip_mc_router;
1579 
1580 	ret = batadv_mcast_forw_want_rtr(bat_priv, skb, vid);
1581 	if (ret != NET_XMIT_SUCCESS) {
1582 		kfree_skb(skb);
1583 		return ret;
1584 	}
1585 
1586 skip_mc_router:
1587 	consume_skb(skb);
1588 	return ret;
1589 }
1590 
1591 /**
1592  * batadv_mcast_want_unsnoop_update() - update unsnoop counter and list
1593  * @bat_priv: the bat priv with all the soft interface information
1594  * @orig: the orig_node which multicast state might have changed of
1595  * @mcast_flags: flags indicating the new multicast state
1596  *
1597  * If the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag of this originator,
1598  * orig, has toggled then this method updates the counter and the list
1599  * accordingly.
1600  *
1601  * Caller needs to hold orig->mcast_handler_lock.
1602  */
1603 static void batadv_mcast_want_unsnoop_update(struct batadv_priv *bat_priv,
1604 					     struct batadv_orig_node *orig,
1605 					     u8 mcast_flags)
1606 {
1607 	struct hlist_node *node = &orig->mcast_want_all_unsnoopables_node;
1608 	struct hlist_head *head = &bat_priv->mcast.want_all_unsnoopables_list;
1609 
1610 	lockdep_assert_held(&orig->mcast_handler_lock);
1611 
1612 	/* switched from flag unset to set */
1613 	if (mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
1614 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)) {
1615 		atomic_inc(&bat_priv->mcast.num_want_all_unsnoopables);
1616 
1617 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1618 		/* flag checks above + mcast_handler_lock prevents this */
1619 		WARN_ON(!hlist_unhashed(node));
1620 
1621 		hlist_add_head_rcu(node, head);
1622 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1623 	/* switched from flag set to unset */
1624 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) &&
1625 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) {
1626 		atomic_dec(&bat_priv->mcast.num_want_all_unsnoopables);
1627 
1628 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1629 		/* flag checks above + mcast_handler_lock prevents this */
1630 		WARN_ON(hlist_unhashed(node));
1631 
1632 		hlist_del_init_rcu(node);
1633 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1634 	}
1635 }
1636 
1637 /**
1638  * batadv_mcast_want_ipv4_update() - update want-all-ipv4 counter and list
1639  * @bat_priv: the bat priv with all the soft interface information
1640  * @orig: the orig_node which multicast state might have changed of
1641  * @mcast_flags: flags indicating the new multicast state
1642  *
1643  * If the BATADV_MCAST_WANT_ALL_IPV4 flag of this originator, orig, has
1644  * toggled then this method updates the counter and the list accordingly.
1645  *
1646  * Caller needs to hold orig->mcast_handler_lock.
1647  */
1648 static void batadv_mcast_want_ipv4_update(struct batadv_priv *bat_priv,
1649 					  struct batadv_orig_node *orig,
1650 					  u8 mcast_flags)
1651 {
1652 	struct hlist_node *node = &orig->mcast_want_all_ipv4_node;
1653 	struct hlist_head *head = &bat_priv->mcast.want_all_ipv4_list;
1654 
1655 	lockdep_assert_held(&orig->mcast_handler_lock);
1656 
1657 	/* switched from flag unset to set */
1658 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4 &&
1659 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)) {
1660 		atomic_inc(&bat_priv->mcast.num_want_all_ipv4);
1661 
1662 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1663 		/* flag checks above + mcast_handler_lock prevents this */
1664 		WARN_ON(!hlist_unhashed(node));
1665 
1666 		hlist_add_head_rcu(node, head);
1667 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1668 	/* switched from flag set to unset */
1669 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) &&
1670 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) {
1671 		atomic_dec(&bat_priv->mcast.num_want_all_ipv4);
1672 
1673 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1674 		/* flag checks above + mcast_handler_lock prevents this */
1675 		WARN_ON(hlist_unhashed(node));
1676 
1677 		hlist_del_init_rcu(node);
1678 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1679 	}
1680 }
1681 
1682 /**
1683  * batadv_mcast_want_ipv6_update() - update want-all-ipv6 counter and list
1684  * @bat_priv: the bat priv with all the soft interface information
1685  * @orig: the orig_node which multicast state might have changed of
1686  * @mcast_flags: flags indicating the new multicast state
1687  *
1688  * If the BATADV_MCAST_WANT_ALL_IPV6 flag of this originator, orig, has
1689  * toggled then this method updates the counter and the list accordingly.
1690  *
1691  * Caller needs to hold orig->mcast_handler_lock.
1692  */
1693 static void batadv_mcast_want_ipv6_update(struct batadv_priv *bat_priv,
1694 					  struct batadv_orig_node *orig,
1695 					  u8 mcast_flags)
1696 {
1697 	struct hlist_node *node = &orig->mcast_want_all_ipv6_node;
1698 	struct hlist_head *head = &bat_priv->mcast.want_all_ipv6_list;
1699 
1700 	lockdep_assert_held(&orig->mcast_handler_lock);
1701 
1702 	/* switched from flag unset to set */
1703 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6 &&
1704 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)) {
1705 		atomic_inc(&bat_priv->mcast.num_want_all_ipv6);
1706 
1707 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1708 		/* flag checks above + mcast_handler_lock prevents this */
1709 		WARN_ON(!hlist_unhashed(node));
1710 
1711 		hlist_add_head_rcu(node, head);
1712 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1713 	/* switched from flag set to unset */
1714 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) &&
1715 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) {
1716 		atomic_dec(&bat_priv->mcast.num_want_all_ipv6);
1717 
1718 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1719 		/* flag checks above + mcast_handler_lock prevents this */
1720 		WARN_ON(hlist_unhashed(node));
1721 
1722 		hlist_del_init_rcu(node);
1723 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1724 	}
1725 }
1726 
1727 /**
1728  * batadv_mcast_want_rtr4_update() - update want-all-rtr4 counter and list
1729  * @bat_priv: the bat priv with all the soft interface information
1730  * @orig: the orig_node which multicast state might have changed of
1731  * @mcast_flags: flags indicating the new multicast state
1732  *
1733  * If the BATADV_MCAST_WANT_NO_RTR4 flag of this originator, orig, has
1734  * toggled then this method updates the counter and the list accordingly.
1735  *
1736  * Caller needs to hold orig->mcast_handler_lock.
1737  */
1738 static void batadv_mcast_want_rtr4_update(struct batadv_priv *bat_priv,
1739 					  struct batadv_orig_node *orig,
1740 					  u8 mcast_flags)
1741 {
1742 	struct hlist_node *node = &orig->mcast_want_all_rtr4_node;
1743 	struct hlist_head *head = &bat_priv->mcast.want_all_rtr4_list;
1744 
1745 	lockdep_assert_held(&orig->mcast_handler_lock);
1746 
1747 	/* switched from flag set to unset */
1748 	if (!(mcast_flags & BATADV_MCAST_WANT_NO_RTR4) &&
1749 	    orig->mcast_flags & BATADV_MCAST_WANT_NO_RTR4) {
1750 		atomic_inc(&bat_priv->mcast.num_want_all_rtr4);
1751 
1752 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1753 		/* flag checks above + mcast_handler_lock prevents this */
1754 		WARN_ON(!hlist_unhashed(node));
1755 
1756 		hlist_add_head_rcu(node, head);
1757 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1758 	/* switched from flag unset to set */
1759 	} else if (mcast_flags & BATADV_MCAST_WANT_NO_RTR4 &&
1760 		   !(orig->mcast_flags & BATADV_MCAST_WANT_NO_RTR4)) {
1761 		atomic_dec(&bat_priv->mcast.num_want_all_rtr4);
1762 
1763 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1764 		/* flag checks above + mcast_handler_lock prevents this */
1765 		WARN_ON(hlist_unhashed(node));
1766 
1767 		hlist_del_init_rcu(node);
1768 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1769 	}
1770 }
1771 
1772 /**
1773  * batadv_mcast_want_rtr6_update() - update want-all-rtr6 counter and list
1774  * @bat_priv: the bat priv with all the soft interface information
1775  * @orig: the orig_node which multicast state might have changed of
1776  * @mcast_flags: flags indicating the new multicast state
1777  *
1778  * If the BATADV_MCAST_WANT_NO_RTR6 flag of this originator, orig, has
1779  * toggled then this method updates the counter and the list accordingly.
1780  *
1781  * Caller needs to hold orig->mcast_handler_lock.
1782  */
1783 static void batadv_mcast_want_rtr6_update(struct batadv_priv *bat_priv,
1784 					  struct batadv_orig_node *orig,
1785 					  u8 mcast_flags)
1786 {
1787 	struct hlist_node *node = &orig->mcast_want_all_rtr6_node;
1788 	struct hlist_head *head = &bat_priv->mcast.want_all_rtr6_list;
1789 
1790 	lockdep_assert_held(&orig->mcast_handler_lock);
1791 
1792 	/* switched from flag set to unset */
1793 	if (!(mcast_flags & BATADV_MCAST_WANT_NO_RTR6) &&
1794 	    orig->mcast_flags & BATADV_MCAST_WANT_NO_RTR6) {
1795 		atomic_inc(&bat_priv->mcast.num_want_all_rtr6);
1796 
1797 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1798 		/* flag checks above + mcast_handler_lock prevents this */
1799 		WARN_ON(!hlist_unhashed(node));
1800 
1801 		hlist_add_head_rcu(node, head);
1802 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1803 	/* switched from flag unset to set */
1804 	} else if (mcast_flags & BATADV_MCAST_WANT_NO_RTR6 &&
1805 		   !(orig->mcast_flags & BATADV_MCAST_WANT_NO_RTR6)) {
1806 		atomic_dec(&bat_priv->mcast.num_want_all_rtr6);
1807 
1808 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1809 		/* flag checks above + mcast_handler_lock prevents this */
1810 		WARN_ON(hlist_unhashed(node));
1811 
1812 		hlist_del_init_rcu(node);
1813 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1814 	}
1815 }
1816 
1817 /**
1818  * batadv_mcast_have_mc_ptype_update() - update multicast packet type counter
1819  * @bat_priv: the bat priv with all the soft interface information
1820  * @orig: the orig_node which multicast state might have changed of
1821  * @mcast_flags: flags indicating the new multicast state
1822  *
1823  * If the BATADV_MCAST_HAVE_MC_PTYPE_CAPA flag of this originator, orig, has
1824  * toggled then this method updates the counter accordingly.
1825  */
1826 static void batadv_mcast_have_mc_ptype_update(struct batadv_priv *bat_priv,
1827 					      struct batadv_orig_node *orig,
1828 					      u8 mcast_flags)
1829 {
1830 	lockdep_assert_held(&orig->mcast_handler_lock);
1831 
1832 	/* switched from flag set to unset */
1833 	if (!(mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) &&
1834 	    orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA)
1835 		atomic_inc(&bat_priv->mcast.num_no_mc_ptype_capa);
1836 	/* switched from flag unset to set */
1837 	else if (mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
1838 		 !(orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA))
1839 		atomic_dec(&bat_priv->mcast.num_no_mc_ptype_capa);
1840 }
1841 
1842 /**
1843  * batadv_mcast_tvlv_flags_get() - get multicast flags from an OGM TVLV
1844  * @enabled: whether the originator has multicast TVLV support enabled
1845  * @tvlv_value: tvlv buffer containing the multicast flags
1846  * @tvlv_value_len: tvlv buffer length
1847  *
1848  * Return: multicast flags for the given tvlv buffer
1849  */
1850 static u8
1851 batadv_mcast_tvlv_flags_get(bool enabled, void *tvlv_value, u16 tvlv_value_len)
1852 {
1853 	u8 mcast_flags = BATADV_NO_FLAGS;
1854 
1855 	if (enabled && tvlv_value && tvlv_value_len >= sizeof(mcast_flags))
1856 		mcast_flags = *(u8 *)tvlv_value;
1857 
1858 	if (!enabled) {
1859 		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV4;
1860 		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV6;
1861 	}
1862 
1863 	/* remove redundant flags to avoid sending duplicate packets later */
1864 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)
1865 		mcast_flags |= BATADV_MCAST_WANT_NO_RTR4;
1866 
1867 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)
1868 		mcast_flags |= BATADV_MCAST_WANT_NO_RTR6;
1869 
1870 	return mcast_flags;
1871 }
1872 
1873 /**
1874  * batadv_mcast_tvlv_ogm_handler() - process incoming multicast tvlv container
1875  * @bat_priv: the bat priv with all the soft interface information
1876  * @orig: the orig_node of the ogm
1877  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
1878  * @tvlv_value: tvlv buffer containing the multicast data
1879  * @tvlv_value_len: tvlv buffer length
1880  */
1881 static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv,
1882 					  struct batadv_orig_node *orig,
1883 					  u8 flags,
1884 					  void *tvlv_value,
1885 					  u16 tvlv_value_len)
1886 {
1887 	bool orig_mcast_enabled = !(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
1888 	u8 mcast_flags;
1889 
1890 	mcast_flags = batadv_mcast_tvlv_flags_get(orig_mcast_enabled,
1891 						  tvlv_value, tvlv_value_len);
1892 
1893 	spin_lock_bh(&orig->mcast_handler_lock);
1894 
1895 	if (orig_mcast_enabled &&
1896 	    !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
1897 		set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
1898 	} else if (!orig_mcast_enabled &&
1899 		   test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
1900 		clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
1901 	}
1902 
1903 	set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized);
1904 
1905 	batadv_mcast_want_unsnoop_update(bat_priv, orig, mcast_flags);
1906 	batadv_mcast_want_ipv4_update(bat_priv, orig, mcast_flags);
1907 	batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
1908 	batadv_mcast_want_rtr4_update(bat_priv, orig, mcast_flags);
1909 	batadv_mcast_want_rtr6_update(bat_priv, orig, mcast_flags);
1910 	batadv_mcast_have_mc_ptype_update(bat_priv, orig, mcast_flags);
1911 
1912 	orig->mcast_flags = mcast_flags;
1913 	spin_unlock_bh(&orig->mcast_handler_lock);
1914 }
1915 
1916 /**
1917  * batadv_mcast_init() - initialize the multicast optimizations structures
1918  * @bat_priv: the bat priv with all the soft interface information
1919  */
1920 void batadv_mcast_init(struct batadv_priv *bat_priv)
1921 {
1922 	batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler,
1923 				     NULL, NULL, BATADV_TVLV_MCAST, 2,
1924 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
1925 	batadv_tvlv_handler_register(bat_priv, NULL, NULL,
1926 				     batadv_mcast_forw_tracker_tvlv_handler,
1927 				     BATADV_TVLV_MCAST_TRACKER, 1,
1928 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
1929 
1930 	INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update);
1931 	batadv_mcast_start_timer(bat_priv);
1932 }
1933 
1934 /**
1935  * batadv_mcast_mesh_info_put() - put multicast info into a netlink message
1936  * @msg: buffer for the message
1937  * @bat_priv: the bat priv with all the soft interface information
1938  *
1939  * Return: 0 or error code.
1940  */
1941 int batadv_mcast_mesh_info_put(struct sk_buff *msg,
1942 			       struct batadv_priv *bat_priv)
1943 {
1944 	u32 flags = bat_priv->mcast.mla_flags.tvlv_flags;
1945 	u32 flags_priv = BATADV_NO_FLAGS;
1946 
1947 	if (bat_priv->mcast.mla_flags.bridged) {
1948 		flags_priv |= BATADV_MCAST_FLAGS_BRIDGED;
1949 
1950 		if (bat_priv->mcast.mla_flags.querier_ipv4.exists)
1951 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_EXISTS;
1952 		if (bat_priv->mcast.mla_flags.querier_ipv6.exists)
1953 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_EXISTS;
1954 		if (bat_priv->mcast.mla_flags.querier_ipv4.shadowing)
1955 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_SHADOWING;
1956 		if (bat_priv->mcast.mla_flags.querier_ipv6.shadowing)
1957 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING;
1958 	}
1959 
1960 	if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS, flags) ||
1961 	    nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS_PRIV, flags_priv))
1962 		return -EMSGSIZE;
1963 
1964 	return 0;
1965 }
1966 
1967 /**
1968  * batadv_mcast_flags_dump_entry() - dump one entry of the multicast flags table
1969  *  to a netlink socket
1970  * @msg: buffer for the message
1971  * @portid: netlink port
1972  * @cb: Control block containing additional options
1973  * @orig_node: originator to dump the multicast flags of
1974  *
1975  * Return: 0 or error code.
1976  */
1977 static int
1978 batadv_mcast_flags_dump_entry(struct sk_buff *msg, u32 portid,
1979 			      struct netlink_callback *cb,
1980 			      struct batadv_orig_node *orig_node)
1981 {
1982 	void *hdr;
1983 
1984 	hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
1985 			  &batadv_netlink_family, NLM_F_MULTI,
1986 			  BATADV_CMD_GET_MCAST_FLAGS);
1987 	if (!hdr)
1988 		return -ENOBUFS;
1989 
1990 	genl_dump_check_consistent(cb, hdr);
1991 
1992 	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
1993 		    orig_node->orig)) {
1994 		genlmsg_cancel(msg, hdr);
1995 		return -EMSGSIZE;
1996 	}
1997 
1998 	if (test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
1999 		     &orig_node->capabilities)) {
2000 		if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS,
2001 				orig_node->mcast_flags)) {
2002 			genlmsg_cancel(msg, hdr);
2003 			return -EMSGSIZE;
2004 		}
2005 	}
2006 
2007 	genlmsg_end(msg, hdr);
2008 	return 0;
2009 }
2010 
2011 /**
2012  * batadv_mcast_flags_dump_bucket() - dump one bucket of the multicast flags
2013  *  table to a netlink socket
2014  * @msg: buffer for the message
2015  * @portid: netlink port
2016  * @cb: Control block containing additional options
2017  * @hash: hash to dump
2018  * @bucket: bucket index to dump
2019  * @idx_skip: How many entries to skip
2020  *
2021  * Return: 0 or error code.
2022  */
2023 static int
2024 batadv_mcast_flags_dump_bucket(struct sk_buff *msg, u32 portid,
2025 			       struct netlink_callback *cb,
2026 			       struct batadv_hashtable *hash,
2027 			       unsigned int bucket, long *idx_skip)
2028 {
2029 	struct batadv_orig_node *orig_node;
2030 	long idx = 0;
2031 
2032 	spin_lock_bh(&hash->list_locks[bucket]);
2033 	cb->seq = atomic_read(&hash->generation) << 1 | 1;
2034 
2035 	hlist_for_each_entry(orig_node, &hash->table[bucket], hash_entry) {
2036 		if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
2037 			      &orig_node->capa_initialized))
2038 			continue;
2039 
2040 		if (idx < *idx_skip)
2041 			goto skip;
2042 
2043 		if (batadv_mcast_flags_dump_entry(msg, portid, cb, orig_node)) {
2044 			spin_unlock_bh(&hash->list_locks[bucket]);
2045 			*idx_skip = idx;
2046 
2047 			return -EMSGSIZE;
2048 		}
2049 
2050 skip:
2051 		idx++;
2052 	}
2053 	spin_unlock_bh(&hash->list_locks[bucket]);
2054 
2055 	return 0;
2056 }
2057 
2058 /**
2059  * __batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
2060  * @msg: buffer for the message
2061  * @portid: netlink port
2062  * @cb: Control block containing additional options
2063  * @bat_priv: the bat priv with all the soft interface information
2064  * @bucket: current bucket to dump
2065  * @idx: index in current bucket to the next entry to dump
2066  *
2067  * Return: 0 or error code.
2068  */
2069 static int
2070 __batadv_mcast_flags_dump(struct sk_buff *msg, u32 portid,
2071 			  struct netlink_callback *cb,
2072 			  struct batadv_priv *bat_priv, long *bucket, long *idx)
2073 {
2074 	struct batadv_hashtable *hash = bat_priv->orig_hash;
2075 	long bucket_tmp = *bucket;
2076 	long idx_tmp = *idx;
2077 
2078 	while (bucket_tmp < hash->size) {
2079 		if (batadv_mcast_flags_dump_bucket(msg, portid, cb, hash,
2080 						   bucket_tmp, &idx_tmp))
2081 			break;
2082 
2083 		bucket_tmp++;
2084 		idx_tmp = 0;
2085 	}
2086 
2087 	*bucket = bucket_tmp;
2088 	*idx = idx_tmp;
2089 
2090 	return msg->len;
2091 }
2092 
2093 /**
2094  * batadv_mcast_netlink_get_primary() - get primary interface from netlink
2095  *  callback
2096  * @cb: netlink callback structure
2097  * @primary_if: the primary interface pointer to return the result in
2098  *
2099  * Return: 0 or error code.
2100  */
2101 static int
2102 batadv_mcast_netlink_get_primary(struct netlink_callback *cb,
2103 				 struct batadv_hard_iface **primary_if)
2104 {
2105 	struct batadv_hard_iface *hard_iface = NULL;
2106 	struct net_device *soft_iface;
2107 	struct batadv_priv *bat_priv;
2108 	int ret = 0;
2109 
2110 	soft_iface = batadv_netlink_get_softif(cb);
2111 	if (IS_ERR(soft_iface))
2112 		return PTR_ERR(soft_iface);
2113 
2114 	bat_priv = netdev_priv(soft_iface);
2115 
2116 	hard_iface = batadv_primary_if_get_selected(bat_priv);
2117 	if (!hard_iface || hard_iface->if_status != BATADV_IF_ACTIVE) {
2118 		ret = -ENOENT;
2119 		goto out;
2120 	}
2121 
2122 out:
2123 	dev_put(soft_iface);
2124 
2125 	if (!ret && primary_if)
2126 		*primary_if = hard_iface;
2127 	else
2128 		batadv_hardif_put(hard_iface);
2129 
2130 	return ret;
2131 }
2132 
2133 /**
2134  * batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
2135  * @msg: buffer for the message
2136  * @cb: callback structure containing arguments
2137  *
2138  * Return: message length.
2139  */
2140 int batadv_mcast_flags_dump(struct sk_buff *msg, struct netlink_callback *cb)
2141 {
2142 	struct batadv_hard_iface *primary_if = NULL;
2143 	int portid = NETLINK_CB(cb->skb).portid;
2144 	struct batadv_priv *bat_priv;
2145 	long *bucket = &cb->args[0];
2146 	long *idx = &cb->args[1];
2147 	int ret;
2148 
2149 	ret = batadv_mcast_netlink_get_primary(cb, &primary_if);
2150 	if (ret)
2151 		return ret;
2152 
2153 	bat_priv = netdev_priv(primary_if->soft_iface);
2154 	ret = __batadv_mcast_flags_dump(msg, portid, cb, bat_priv, bucket, idx);
2155 
2156 	batadv_hardif_put(primary_if);
2157 	return ret;
2158 }
2159 
2160 /**
2161  * batadv_mcast_free() - free the multicast optimizations structures
2162  * @bat_priv: the bat priv with all the soft interface information
2163  */
2164 void batadv_mcast_free(struct batadv_priv *bat_priv)
2165 {
2166 	cancel_delayed_work_sync(&bat_priv->mcast.work);
2167 
2168 	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
2169 	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST_TRACKER, 1);
2170 	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
2171 
2172 	/* safely calling outside of worker, as worker was canceled above */
2173 	batadv_mcast_mla_tt_retract(bat_priv, NULL);
2174 }
2175 
2176 /**
2177  * batadv_mcast_purge_orig() - reset originator global mcast state modifications
2178  * @orig: the originator which is going to get purged
2179  */
2180 void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
2181 {
2182 	struct batadv_priv *bat_priv = orig->bat_priv;
2183 
2184 	spin_lock_bh(&orig->mcast_handler_lock);
2185 
2186 	batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
2187 	batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS);
2188 	batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS);
2189 	batadv_mcast_want_rtr4_update(bat_priv, orig,
2190 				      BATADV_MCAST_WANT_NO_RTR4);
2191 	batadv_mcast_want_rtr6_update(bat_priv, orig,
2192 				      BATADV_MCAST_WANT_NO_RTR6);
2193 	batadv_mcast_have_mc_ptype_update(bat_priv, orig,
2194 					  BATADV_MCAST_HAVE_MC_PTYPE_CAPA);
2195 
2196 	spin_unlock_bh(&orig->mcast_handler_lock);
2197 }
2198