xref: /openbmc/linux/net/batman-adv/multicast.c (revision b9b77222)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2014-2018  B.A.T.M.A.N. contributors:
3  *
4  * Linus Lüssing
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "multicast.h"
20 #include "main.h"
21 
22 #include <linux/atomic.h>
23 #include <linux/bitops.h>
24 #include <linux/bug.h>
25 #include <linux/byteorder/generic.h>
26 #include <linux/errno.h>
27 #include <linux/etherdevice.h>
28 #include <linux/gfp.h>
29 #include <linux/icmpv6.h>
30 #include <linux/if_bridge.h>
31 #include <linux/if_ether.h>
32 #include <linux/igmp.h>
33 #include <linux/in.h>
34 #include <linux/in6.h>
35 #include <linux/ip.h>
36 #include <linux/ipv6.h>
37 #include <linux/jiffies.h>
38 #include <linux/kernel.h>
39 #include <linux/kref.h>
40 #include <linux/list.h>
41 #include <linux/lockdep.h>
42 #include <linux/netdevice.h>
43 #include <linux/netlink.h>
44 #include <linux/printk.h>
45 #include <linux/rculist.h>
46 #include <linux/rcupdate.h>
47 #include <linux/seq_file.h>
48 #include <linux/skbuff.h>
49 #include <linux/slab.h>
50 #include <linux/spinlock.h>
51 #include <linux/stddef.h>
52 #include <linux/string.h>
53 #include <linux/types.h>
54 #include <linux/workqueue.h>
55 #include <net/addrconf.h>
56 #include <net/genetlink.h>
57 #include <net/if_inet6.h>
58 #include <net/ip.h>
59 #include <net/ipv6.h>
60 #include <net/netlink.h>
61 #include <net/sock.h>
62 #include <uapi/linux/batadv_packet.h>
63 #include <uapi/linux/batman_adv.h>
64 
65 #include "hard-interface.h"
66 #include "hash.h"
67 #include "log.h"
68 #include "netlink.h"
69 #include "soft-interface.h"
70 #include "translation-table.h"
71 #include "tvlv.h"
72 
73 static void batadv_mcast_mla_update(struct work_struct *work);
74 
75 /**
76  * batadv_mcast_start_timer() - schedule the multicast periodic worker
77  * @bat_priv: the bat priv with all the soft interface information
78  */
79 static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
80 {
81 	queue_delayed_work(batadv_event_workqueue, &bat_priv->mcast.work,
82 			   msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
83 }
84 
85 /**
86  * batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists
87  * @soft_iface: netdev struct of the mesh interface
88  *
89  * If the given soft interface has a bridge on top then the refcount
90  * of the according net device is increased.
91  *
92  * Return: NULL if no such bridge exists. Otherwise the net device of the
93  * bridge.
94  */
95 static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
96 {
97 	struct net_device *upper = soft_iface;
98 
99 	rcu_read_lock();
100 	do {
101 		upper = netdev_master_upper_dev_get_rcu(upper);
102 	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));
103 
104 	if (upper)
105 		dev_hold(upper);
106 	rcu_read_unlock();
107 
108 	return upper;
109 }
110 
111 /**
112  * batadv_mcast_addr_is_ipv4() - check if multicast MAC is IPv4
113  * @addr: the MAC address to check
114  *
115  * Return: True, if MAC address is one reserved for IPv4 multicast, false
116  * otherwise.
117  */
118 static bool batadv_mcast_addr_is_ipv4(const u8 *addr)
119 {
120 	static const u8 prefix[] = {0x01, 0x00, 0x5E};
121 
122 	return memcmp(prefix, addr, sizeof(prefix)) == 0;
123 }
124 
125 /**
126  * batadv_mcast_addr_is_ipv6() - check if multicast MAC is IPv6
127  * @addr: the MAC address to check
128  *
129  * Return: True, if MAC address is one reserved for IPv6 multicast, false
130  * otherwise.
131  */
132 static bool batadv_mcast_addr_is_ipv6(const u8 *addr)
133 {
134 	static const u8 prefix[] = {0x33, 0x33};
135 
136 	return memcmp(prefix, addr, sizeof(prefix)) == 0;
137 }
138 
139 /**
140  * batadv_mcast_mla_softif_get() - get softif multicast listeners
141  * @bat_priv: the bat priv with all the soft interface information
142  * @dev: the device to collect multicast addresses from
143  * @mcast_list: a list to put found addresses into
144  *
145  * Collects multicast addresses of multicast listeners residing
146  * on this kernel on the given soft interface, dev, in
147  * the given mcast_list. In general, multicast listeners provided by
148  * your multicast receiving applications run directly on this node.
149  *
150  * If there is a bridge interface on top of dev, collects from that one
151  * instead. Just like with IP addresses and routes, multicast listeners
152  * will(/should) register to the bridge interface instead of an
153  * enslaved bat0.
154  *
155  * Return: -ENOMEM on memory allocation error or the number of
156  * items added to the mcast_list otherwise.
157  */
158 static int batadv_mcast_mla_softif_get(struct batadv_priv *bat_priv,
159 				       struct net_device *dev,
160 				       struct hlist_head *mcast_list)
161 {
162 	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
163 	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
164 	struct net_device *bridge = batadv_mcast_get_bridge(dev);
165 	struct netdev_hw_addr *mc_list_entry;
166 	struct batadv_hw_addr *new;
167 	int ret = 0;
168 
169 	netif_addr_lock_bh(bridge ? bridge : dev);
170 	netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) {
171 		if (all_ipv4 && batadv_mcast_addr_is_ipv4(mc_list_entry->addr))
172 			continue;
173 
174 		if (all_ipv6 && batadv_mcast_addr_is_ipv6(mc_list_entry->addr))
175 			continue;
176 
177 		new = kmalloc(sizeof(*new), GFP_ATOMIC);
178 		if (!new) {
179 			ret = -ENOMEM;
180 			break;
181 		}
182 
183 		ether_addr_copy(new->addr, mc_list_entry->addr);
184 		hlist_add_head(&new->list, mcast_list);
185 		ret++;
186 	}
187 	netif_addr_unlock_bh(bridge ? bridge : dev);
188 
189 	if (bridge)
190 		dev_put(bridge);
191 
192 	return ret;
193 }
194 
195 /**
196  * batadv_mcast_mla_is_duplicate() - check whether an address is in a list
197  * @mcast_addr: the multicast address to check
198  * @mcast_list: the list with multicast addresses to search in
199  *
200  * Return: true if the given address is already in the given list.
201  * Otherwise returns false.
202  */
203 static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,
204 					  struct hlist_head *mcast_list)
205 {
206 	struct batadv_hw_addr *mcast_entry;
207 
208 	hlist_for_each_entry(mcast_entry, mcast_list, list)
209 		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))
210 			return true;
211 
212 	return false;
213 }
214 
215 /**
216  * batadv_mcast_mla_br_addr_cpy() - copy a bridge multicast address
217  * @dst: destination to write to - a multicast MAC address
218  * @src: source to read from - a multicast IP address
219  *
220  * Converts a given multicast IPv4/IPv6 address from a bridge
221  * to its matching multicast MAC address and copies it into the given
222  * destination buffer.
223  *
224  * Caller needs to make sure the destination buffer can hold
225  * at least ETH_ALEN bytes.
226  */
227 static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
228 {
229 	if (src->proto == htons(ETH_P_IP))
230 		ip_eth_mc_map(src->u.ip4, dst);
231 #if IS_ENABLED(CONFIG_IPV6)
232 	else if (src->proto == htons(ETH_P_IPV6))
233 		ipv6_eth_mc_map(&src->u.ip6, dst);
234 #endif
235 	else
236 		eth_zero_addr(dst);
237 }
238 
239 /**
240  * batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners
241  * @bat_priv: the bat priv with all the soft interface information
242  * @dev: a bridge slave whose bridge to collect multicast addresses from
243  * @mcast_list: a list to put found addresses into
244  *
245  * Collects multicast addresses of multicast listeners residing
246  * on foreign, non-mesh devices which we gave access to our mesh via
247  * a bridge on top of the given soft interface, dev, in the given
248  * mcast_list.
249  *
250  * Return: -ENOMEM on memory allocation error or the number of
251  * items added to the mcast_list otherwise.
252  */
253 static int batadv_mcast_mla_bridge_get(struct batadv_priv *bat_priv,
254 				       struct net_device *dev,
255 				       struct hlist_head *mcast_list)
256 {
257 	struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
258 	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
259 	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
260 	struct br_ip_list *br_ip_entry, *tmp;
261 	struct batadv_hw_addr *new;
262 	u8 mcast_addr[ETH_ALEN];
263 	int ret;
264 
265 	/* we don't need to detect these devices/listeners, the IGMP/MLD
266 	 * snooping code of the Linux bridge already does that for us
267 	 */
268 	ret = br_multicast_list_adjacent(dev, &bridge_mcast_list);
269 	if (ret < 0)
270 		goto out;
271 
272 	list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) {
273 		if (all_ipv4 && br_ip_entry->addr.proto == htons(ETH_P_IP))
274 			continue;
275 
276 		if (all_ipv6 && br_ip_entry->addr.proto == htons(ETH_P_IPV6))
277 			continue;
278 
279 		batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr);
280 		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
281 			continue;
282 
283 		new = kmalloc(sizeof(*new), GFP_ATOMIC);
284 		if (!new) {
285 			ret = -ENOMEM;
286 			break;
287 		}
288 
289 		ether_addr_copy(new->addr, mcast_addr);
290 		hlist_add_head(&new->list, mcast_list);
291 	}
292 
293 out:
294 	list_for_each_entry_safe(br_ip_entry, tmp, &bridge_mcast_list, list) {
295 		list_del(&br_ip_entry->list);
296 		kfree(br_ip_entry);
297 	}
298 
299 	return ret;
300 }
301 
302 /**
303  * batadv_mcast_mla_list_free() - free a list of multicast addresses
304  * @mcast_list: the list to free
305  *
306  * Removes and frees all items in the given mcast_list.
307  */
308 static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)
309 {
310 	struct batadv_hw_addr *mcast_entry;
311 	struct hlist_node *tmp;
312 
313 	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
314 		hlist_del(&mcast_entry->list);
315 		kfree(mcast_entry);
316 	}
317 }
318 
319 /**
320  * batadv_mcast_mla_tt_retract() - clean up multicast listener announcements
321  * @bat_priv: the bat priv with all the soft interface information
322  * @mcast_list: a list of addresses which should _not_ be removed
323  *
324  * Retracts the announcement of any multicast listener from the
325  * translation table except the ones listed in the given mcast_list.
326  *
327  * If mcast_list is NULL then all are retracted.
328  *
329  * Do not call outside of the mcast worker! (or cancel mcast worker first)
330  */
331 static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
332 					struct hlist_head *mcast_list)
333 {
334 	struct batadv_hw_addr *mcast_entry;
335 	struct hlist_node *tmp;
336 
337 	WARN_ON(delayed_work_pending(&bat_priv->mcast.work));
338 
339 	hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
340 				  list) {
341 		if (mcast_list &&
342 		    batadv_mcast_mla_is_duplicate(mcast_entry->addr,
343 						  mcast_list))
344 			continue;
345 
346 		batadv_tt_local_remove(bat_priv, mcast_entry->addr,
347 				       BATADV_NO_FLAGS,
348 				       "mcast TT outdated", false);
349 
350 		hlist_del(&mcast_entry->list);
351 		kfree(mcast_entry);
352 	}
353 }
354 
355 /**
356  * batadv_mcast_mla_tt_add() - add multicast listener announcements
357  * @bat_priv: the bat priv with all the soft interface information
358  * @mcast_list: a list of addresses which are going to get added
359  *
360  * Adds multicast listener announcements from the given mcast_list to the
361  * translation table if they have not been added yet.
362  *
363  * Do not call outside of the mcast worker! (or cancel mcast worker first)
364  */
365 static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
366 				    struct hlist_head *mcast_list)
367 {
368 	struct batadv_hw_addr *mcast_entry;
369 	struct hlist_node *tmp;
370 
371 	WARN_ON(delayed_work_pending(&bat_priv->mcast.work));
372 
373 	if (!mcast_list)
374 		return;
375 
376 	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
377 		if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,
378 						  &bat_priv->mcast.mla_list))
379 			continue;
380 
381 		if (!batadv_tt_local_add(bat_priv->soft_iface,
382 					 mcast_entry->addr, BATADV_NO_FLAGS,
383 					 BATADV_NULL_IFINDEX, BATADV_NO_MARK))
384 			continue;
385 
386 		hlist_del(&mcast_entry->list);
387 		hlist_add_head(&mcast_entry->list, &bat_priv->mcast.mla_list);
388 	}
389 }
390 
391 /**
392  * batadv_mcast_has_bridge() - check whether the soft-iface is bridged
393  * @bat_priv: the bat priv with all the soft interface information
394  *
395  * Checks whether there is a bridge on top of our soft interface.
396  *
397  * Return: true if there is a bridge, false otherwise.
398  */
399 static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)
400 {
401 	struct net_device *upper = bat_priv->soft_iface;
402 
403 	rcu_read_lock();
404 	do {
405 		upper = netdev_master_upper_dev_get_rcu(upper);
406 	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));
407 	rcu_read_unlock();
408 
409 	return upper;
410 }
411 
412 /**
413  * batadv_mcast_querier_log() - debug output regarding the querier status on
414  *  link
415  * @bat_priv: the bat priv with all the soft interface information
416  * @str_proto: a string for the querier protocol (e.g. "IGMP" or "MLD")
417  * @old_state: the previous querier state on our link
418  * @new_state: the new querier state on our link
419  *
420  * Outputs debug messages to the logging facility with log level 'mcast'
421  * regarding changes to the querier status on the link which are relevant
422  * to our multicast optimizations.
423  *
424  * Usually this is about whether a querier appeared or vanished in
425  * our mesh or whether the querier is in the suboptimal position of being
426  * behind our local bridge segment: Snooping switches will directly
427  * forward listener reports to the querier, therefore batman-adv and
428  * the bridge will potentially not see these listeners - the querier is
429  * potentially shadowing listeners from us then.
430  *
431  * This is only interesting for nodes with a bridge on top of their
432  * soft interface.
433  */
434 static void
435 batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto,
436 			 struct batadv_mcast_querier_state *old_state,
437 			 struct batadv_mcast_querier_state *new_state)
438 {
439 	if (!old_state->exists && new_state->exists)
440 		batadv_info(bat_priv->soft_iface, "%s Querier appeared\n",
441 			    str_proto);
442 	else if (old_state->exists && !new_state->exists)
443 		batadv_info(bat_priv->soft_iface,
444 			    "%s Querier disappeared - multicast optimizations disabled\n",
445 			    str_proto);
446 	else if (!bat_priv->mcast.bridged && !new_state->exists)
447 		batadv_info(bat_priv->soft_iface,
448 			    "No %s Querier present - multicast optimizations disabled\n",
449 			    str_proto);
450 
451 	if (new_state->exists) {
452 		if ((!old_state->shadowing && new_state->shadowing) ||
453 		    (!old_state->exists && new_state->shadowing))
454 			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
455 				   "%s Querier is behind our bridged segment: Might shadow listeners\n",
456 				   str_proto);
457 		else if (old_state->shadowing && !new_state->shadowing)
458 			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
459 				   "%s Querier is not behind our bridged segment\n",
460 				   str_proto);
461 	}
462 }
463 
464 /**
465  * batadv_mcast_bridge_log() - debug output for topology changes in bridged
466  *  setups
467  * @bat_priv: the bat priv with all the soft interface information
468  * @bridged: a flag about whether the soft interface is currently bridged or not
469  * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier
470  * @querier_ipv6: (maybe) new status of a potential, selected MLD querier
471  *
472  * If no bridges are ever used on this node, then this function does nothing.
473  *
474  * Otherwise this function outputs debug information to the 'mcast' log level
475  * which might be relevant to our multicast optimizations.
476  *
477  * More precisely, it outputs information when a bridge interface is added or
478  * removed from a soft interface. And when a bridge is present, it further
479  * outputs information about the querier state which is relevant for the
480  * multicast flags this node is going to set.
481  */
482 static void
483 batadv_mcast_bridge_log(struct batadv_priv *bat_priv, bool bridged,
484 			struct batadv_mcast_querier_state *querier_ipv4,
485 			struct batadv_mcast_querier_state *querier_ipv6)
486 {
487 	if (!bat_priv->mcast.bridged && bridged)
488 		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
489 			   "Bridge added: Setting Unsnoopables(U)-flag\n");
490 	else if (bat_priv->mcast.bridged && !bridged)
491 		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
492 			   "Bridge removed: Unsetting Unsnoopables(U)-flag\n");
493 
494 	if (bridged) {
495 		batadv_mcast_querier_log(bat_priv, "IGMP",
496 					 &bat_priv->mcast.querier_ipv4,
497 					 querier_ipv4);
498 		batadv_mcast_querier_log(bat_priv, "MLD",
499 					 &bat_priv->mcast.querier_ipv6,
500 					 querier_ipv6);
501 	}
502 }
503 
504 /**
505  * batadv_mcast_flags_logs() - output debug information about mcast flag changes
506  * @bat_priv: the bat priv with all the soft interface information
507  * @flags: flags indicating the new multicast state
508  *
509  * Whenever the multicast flags this nodes announces changes (@mcast_flags vs.
510  * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level.
511  */
512 static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)
513 {
514 	u8 old_flags = bat_priv->mcast.flags;
515 	char str_old_flags[] = "[...]";
516 
517 	sprintf(str_old_flags, "[%c%c%c]",
518 		(old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
519 		(old_flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
520 		(old_flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
521 
522 	batadv_dbg(BATADV_DBG_MCAST, bat_priv,
523 		   "Changing multicast flags from '%s' to '[%c%c%c]'\n",
524 		   bat_priv->mcast.enabled ? str_old_flags : "<undefined>",
525 		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
526 		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
527 		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
528 }
529 
530 /**
531  * batadv_mcast_mla_tvlv_update() - update multicast tvlv
532  * @bat_priv: the bat priv with all the soft interface information
533  *
534  * Updates the own multicast tvlv with our current multicast related settings,
535  * capabilities and inabilities.
536  *
537  * Return: false if we want all IPv4 && IPv6 multicast traffic and true
538  * otherwise.
539  */
540 static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
541 {
542 	struct batadv_tvlv_mcast_data mcast_data;
543 	struct batadv_mcast_querier_state querier4 = {false, false};
544 	struct batadv_mcast_querier_state querier6 = {false, false};
545 	struct net_device *dev = bat_priv->soft_iface;
546 	bool bridged;
547 
548 	mcast_data.flags = BATADV_NO_FLAGS;
549 	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
550 
551 	bridged = batadv_mcast_has_bridge(bat_priv);
552 	if (!bridged)
553 		goto update;
554 
555 	if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))
556 		pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");
557 
558 	querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);
559 	querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);
560 
561 	querier6.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);
562 	querier6.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);
563 
564 	mcast_data.flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;
565 
566 	/* 1) If no querier exists at all, then multicast listeners on
567 	 *    our local TT clients behind the bridge will keep silent.
568 	 * 2) If the selected querier is on one of our local TT clients,
569 	 *    behind the bridge, then this querier might shadow multicast
570 	 *    listeners on our local TT clients, behind this bridge.
571 	 *
572 	 * In both cases, we will signalize other batman nodes that
573 	 * we need all multicast traffic of the according protocol.
574 	 */
575 	if (!querier4.exists || querier4.shadowing)
576 		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4;
577 
578 	if (!querier6.exists || querier6.shadowing)
579 		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6;
580 
581 update:
582 	batadv_mcast_bridge_log(bat_priv, bridged, &querier4, &querier6);
583 
584 	bat_priv->mcast.querier_ipv4.exists = querier4.exists;
585 	bat_priv->mcast.querier_ipv4.shadowing = querier4.shadowing;
586 
587 	bat_priv->mcast.querier_ipv6.exists = querier6.exists;
588 	bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing;
589 
590 	bat_priv->mcast.bridged = bridged;
591 
592 	if (!bat_priv->mcast.enabled ||
593 	    mcast_data.flags != bat_priv->mcast.flags) {
594 		batadv_mcast_flags_log(bat_priv, mcast_data.flags);
595 		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,
596 					       &mcast_data, sizeof(mcast_data));
597 		bat_priv->mcast.flags = mcast_data.flags;
598 		bat_priv->mcast.enabled = true;
599 	}
600 
601 	return !(mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV4 &&
602 		 mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV6);
603 }
604 
605 /**
606  * __batadv_mcast_mla_update() - update the own MLAs
607  * @bat_priv: the bat priv with all the soft interface information
608  *
609  * Updates the own multicast listener announcements in the translation
610  * table as well as the own, announced multicast tvlv container.
611  *
612  * Note that non-conflicting reads and writes to bat_priv->mcast.mla_list
613  * in batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add() are
614  * ensured by the non-parallel execution of the worker this function
615  * belongs to.
616  */
617 static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv)
618 {
619 	struct net_device *soft_iface = bat_priv->soft_iface;
620 	struct hlist_head mcast_list = HLIST_HEAD_INIT;
621 	int ret;
622 
623 	if (!batadv_mcast_mla_tvlv_update(bat_priv))
624 		goto update;
625 
626 	ret = batadv_mcast_mla_softif_get(bat_priv, soft_iface, &mcast_list);
627 	if (ret < 0)
628 		goto out;
629 
630 	ret = batadv_mcast_mla_bridge_get(bat_priv, soft_iface, &mcast_list);
631 	if (ret < 0)
632 		goto out;
633 
634 update:
635 	batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);
636 	batadv_mcast_mla_tt_add(bat_priv, &mcast_list);
637 
638 out:
639 	batadv_mcast_mla_list_free(&mcast_list);
640 }
641 
642 /**
643  * batadv_mcast_mla_update() - update the own MLAs
644  * @work: kernel work struct
645  *
646  * Updates the own multicast listener announcements in the translation
647  * table as well as the own, announced multicast tvlv container.
648  *
649  * In the end, reschedules the work timer.
650  */
651 static void batadv_mcast_mla_update(struct work_struct *work)
652 {
653 	struct delayed_work *delayed_work;
654 	struct batadv_priv_mcast *priv_mcast;
655 	struct batadv_priv *bat_priv;
656 
657 	delayed_work = to_delayed_work(work);
658 	priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);
659 	bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);
660 
661 	__batadv_mcast_mla_update(bat_priv);
662 	batadv_mcast_start_timer(bat_priv);
663 }
664 
665 /**
666  * batadv_mcast_is_report_ipv4() - check for IGMP reports
667  * @skb: the ethernet frame destined for the mesh
668  *
669  * This call might reallocate skb data.
670  *
671  * Checks whether the given frame is a valid IGMP report.
672  *
673  * Return: If so then true, otherwise false.
674  */
675 static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
676 {
677 	if (ip_mc_check_igmp(skb, NULL) < 0)
678 		return false;
679 
680 	switch (igmp_hdr(skb)->type) {
681 	case IGMP_HOST_MEMBERSHIP_REPORT:
682 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
683 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
684 		return true;
685 	}
686 
687 	return false;
688 }
689 
690 /**
691  * batadv_mcast_forw_mode_check_ipv4() - check for optimized forwarding
692  *  potential
693  * @bat_priv: the bat priv with all the soft interface information
694  * @skb: the IPv4 packet to check
695  * @is_unsnoopable: stores whether the destination is snoopable
696  *
697  * Checks whether the given IPv4 packet has the potential to be forwarded with a
698  * mode more optimal than classic flooding.
699  *
700  * Return: If so then 0. Otherwise -EINVAL or -ENOMEM in case of memory
701  * allocation failure.
702  */
703 static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
704 					     struct sk_buff *skb,
705 					     bool *is_unsnoopable)
706 {
707 	struct iphdr *iphdr;
708 
709 	/* We might fail due to out-of-memory -> drop it */
710 	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*iphdr)))
711 		return -ENOMEM;
712 
713 	if (batadv_mcast_is_report_ipv4(skb))
714 		return -EINVAL;
715 
716 	iphdr = ip_hdr(skb);
717 
718 	/* TODO: Implement Multicast Router Discovery (RFC4286),
719 	 * then allow scope > link local, too
720 	 */
721 	if (!ipv4_is_local_multicast(iphdr->daddr))
722 		return -EINVAL;
723 
724 	/* link-local multicast listeners behind a bridge are
725 	 * not snoopable (see RFC4541, section 2.1.2.2)
726 	 */
727 	*is_unsnoopable = true;
728 
729 	return 0;
730 }
731 
732 /**
733  * batadv_mcast_is_report_ipv6() - check for MLD reports
734  * @skb: the ethernet frame destined for the mesh
735  *
736  * This call might reallocate skb data.
737  *
738  * Checks whether the given frame is a valid MLD report.
739  *
740  * Return: If so then true, otherwise false.
741  */
742 static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb)
743 {
744 	if (ipv6_mc_check_mld(skb, NULL) < 0)
745 		return false;
746 
747 	switch (icmp6_hdr(skb)->icmp6_type) {
748 	case ICMPV6_MGM_REPORT:
749 	case ICMPV6_MLD2_REPORT:
750 		return true;
751 	}
752 
753 	return false;
754 }
755 
756 /**
757  * batadv_mcast_forw_mode_check_ipv6() - check for optimized forwarding
758  *  potential
759  * @bat_priv: the bat priv with all the soft interface information
760  * @skb: the IPv6 packet to check
761  * @is_unsnoopable: stores whether the destination is snoopable
762  *
763  * Checks whether the given IPv6 packet has the potential to be forwarded with a
764  * mode more optimal than classic flooding.
765  *
766  * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
767  */
768 static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
769 					     struct sk_buff *skb,
770 					     bool *is_unsnoopable)
771 {
772 	struct ipv6hdr *ip6hdr;
773 
774 	/* We might fail due to out-of-memory -> drop it */
775 	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr)))
776 		return -ENOMEM;
777 
778 	if (batadv_mcast_is_report_ipv6(skb))
779 		return -EINVAL;
780 
781 	ip6hdr = ipv6_hdr(skb);
782 
783 	/* TODO: Implement Multicast Router Discovery (RFC4286),
784 	 * then allow scope > link local, too
785 	 */
786 	if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL)
787 		return -EINVAL;
788 
789 	/* link-local-all-nodes multicast listeners behind a bridge are
790 	 * not snoopable (see RFC4541, section 3, paragraph 3)
791 	 */
792 	if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr))
793 		*is_unsnoopable = true;
794 
795 	return 0;
796 }
797 
798 /**
799  * batadv_mcast_forw_mode_check() - check for optimized forwarding potential
800  * @bat_priv: the bat priv with all the soft interface information
801  * @skb: the multicast frame to check
802  * @is_unsnoopable: stores whether the destination is snoopable
803  *
804  * Checks whether the given multicast ethernet frame has the potential to be
805  * forwarded with a mode more optimal than classic flooding.
806  *
807  * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
808  */
809 static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
810 					struct sk_buff *skb,
811 					bool *is_unsnoopable)
812 {
813 	struct ethhdr *ethhdr = eth_hdr(skb);
814 
815 	if (!atomic_read(&bat_priv->multicast_mode))
816 		return -EINVAL;
817 
818 	switch (ntohs(ethhdr->h_proto)) {
819 	case ETH_P_IP:
820 		return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb,
821 							 is_unsnoopable);
822 	case ETH_P_IPV6:
823 		if (!IS_ENABLED(CONFIG_IPV6))
824 			return -EINVAL;
825 
826 		return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb,
827 							 is_unsnoopable);
828 	default:
829 		return -EINVAL;
830 	}
831 }
832 
833 /**
834  * batadv_mcast_forw_want_all_ip_count() - count nodes with unspecific mcast
835  *  interest
836  * @bat_priv: the bat priv with all the soft interface information
837  * @ethhdr: ethernet header of a packet
838  *
839  * Return: the number of nodes which want all IPv4 multicast traffic if the
840  * given ethhdr is from an IPv4 packet or the number of nodes which want all
841  * IPv6 traffic if it matches an IPv6 packet.
842  */
843 static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv,
844 					       struct ethhdr *ethhdr)
845 {
846 	switch (ntohs(ethhdr->h_proto)) {
847 	case ETH_P_IP:
848 		return atomic_read(&bat_priv->mcast.num_want_all_ipv4);
849 	case ETH_P_IPV6:
850 		return atomic_read(&bat_priv->mcast.num_want_all_ipv6);
851 	default:
852 		/* we shouldn't be here... */
853 		return 0;
854 	}
855 }
856 
857 /**
858  * batadv_mcast_forw_tt_node_get() - get a multicast tt node
859  * @bat_priv: the bat priv with all the soft interface information
860  * @ethhdr: the ether header containing the multicast destination
861  *
862  * Return: an orig_node matching the multicast address provided by ethhdr
863  * via a translation table lookup. This increases the returned nodes refcount.
864  */
865 static struct batadv_orig_node *
866 batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv,
867 			      struct ethhdr *ethhdr)
868 {
869 	return batadv_transtable_search(bat_priv, NULL, ethhdr->h_dest,
870 					BATADV_NO_FLAGS);
871 }
872 
873 /**
874  * batadv_mcast_forw_ipv4_node_get() - get a node with an ipv4 flag
875  * @bat_priv: the bat priv with all the soft interface information
876  *
877  * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 flag set and
878  * increases its refcount.
879  */
880 static struct batadv_orig_node *
881 batadv_mcast_forw_ipv4_node_get(struct batadv_priv *bat_priv)
882 {
883 	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
884 
885 	rcu_read_lock();
886 	hlist_for_each_entry_rcu(tmp_orig_node,
887 				 &bat_priv->mcast.want_all_ipv4_list,
888 				 mcast_want_all_ipv4_node) {
889 		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
890 			continue;
891 
892 		orig_node = tmp_orig_node;
893 		break;
894 	}
895 	rcu_read_unlock();
896 
897 	return orig_node;
898 }
899 
900 /**
901  * batadv_mcast_forw_ipv6_node_get() - get a node with an ipv6 flag
902  * @bat_priv: the bat priv with all the soft interface information
903  *
904  * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV6 flag set
905  * and increases its refcount.
906  */
907 static struct batadv_orig_node *
908 batadv_mcast_forw_ipv6_node_get(struct batadv_priv *bat_priv)
909 {
910 	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
911 
912 	rcu_read_lock();
913 	hlist_for_each_entry_rcu(tmp_orig_node,
914 				 &bat_priv->mcast.want_all_ipv6_list,
915 				 mcast_want_all_ipv6_node) {
916 		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
917 			continue;
918 
919 		orig_node = tmp_orig_node;
920 		break;
921 	}
922 	rcu_read_unlock();
923 
924 	return orig_node;
925 }
926 
927 /**
928  * batadv_mcast_forw_ip_node_get() - get a node with an ipv4/ipv6 flag
929  * @bat_priv: the bat priv with all the soft interface information
930  * @ethhdr: an ethernet header to determine the protocol family from
931  *
932  * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 or
933  * BATADV_MCAST_WANT_ALL_IPV6 flag, depending on the provided ethhdr, set and
934  * increases its refcount.
935  */
936 static struct batadv_orig_node *
937 batadv_mcast_forw_ip_node_get(struct batadv_priv *bat_priv,
938 			      struct ethhdr *ethhdr)
939 {
940 	switch (ntohs(ethhdr->h_proto)) {
941 	case ETH_P_IP:
942 		return batadv_mcast_forw_ipv4_node_get(bat_priv);
943 	case ETH_P_IPV6:
944 		return batadv_mcast_forw_ipv6_node_get(bat_priv);
945 	default:
946 		/* we shouldn't be here... */
947 		return NULL;
948 	}
949 }
950 
951 /**
952  * batadv_mcast_forw_unsnoop_node_get() - get a node with an unsnoopable flag
953  * @bat_priv: the bat priv with all the soft interface information
954  *
955  * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag
956  * set and increases its refcount.
957  */
958 static struct batadv_orig_node *
959 batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv)
960 {
961 	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
962 
963 	rcu_read_lock();
964 	hlist_for_each_entry_rcu(tmp_orig_node,
965 				 &bat_priv->mcast.want_all_unsnoopables_list,
966 				 mcast_want_all_unsnoopables_node) {
967 		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
968 			continue;
969 
970 		orig_node = tmp_orig_node;
971 		break;
972 	}
973 	rcu_read_unlock();
974 
975 	return orig_node;
976 }
977 
978 /**
979  * batadv_mcast_forw_mode() - check on how to forward a multicast packet
980  * @bat_priv: the bat priv with all the soft interface information
981  * @skb: The multicast packet to check
982  * @orig: an originator to be set to forward the skb to
983  *
984  * Return: the forwarding mode as enum batadv_forw_mode and in case of
985  * BATADV_FORW_SINGLE set the orig to the single originator the skb
986  * should be forwarded to.
987  */
988 enum batadv_forw_mode
989 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
990 		       struct batadv_orig_node **orig)
991 {
992 	int ret, tt_count, ip_count, unsnoop_count, total_count;
993 	bool is_unsnoopable = false;
994 	struct ethhdr *ethhdr;
995 
996 	ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable);
997 	if (ret == -ENOMEM)
998 		return BATADV_FORW_NONE;
999 	else if (ret < 0)
1000 		return BATADV_FORW_ALL;
1001 
1002 	ethhdr = eth_hdr(skb);
1003 
1004 	tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest,
1005 					       BATADV_NO_FLAGS);
1006 	ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr);
1007 	unsnoop_count = !is_unsnoopable ? 0 :
1008 			atomic_read(&bat_priv->mcast.num_want_all_unsnoopables);
1009 
1010 	total_count = tt_count + ip_count + unsnoop_count;
1011 
1012 	switch (total_count) {
1013 	case 1:
1014 		if (tt_count)
1015 			*orig = batadv_mcast_forw_tt_node_get(bat_priv, ethhdr);
1016 		else if (ip_count)
1017 			*orig = batadv_mcast_forw_ip_node_get(bat_priv, ethhdr);
1018 		else if (unsnoop_count)
1019 			*orig = batadv_mcast_forw_unsnoop_node_get(bat_priv);
1020 
1021 		if (*orig)
1022 			return BATADV_FORW_SINGLE;
1023 
1024 		/* fall through */
1025 	case 0:
1026 		return BATADV_FORW_NONE;
1027 	default:
1028 		return BATADV_FORW_ALL;
1029 	}
1030 }
1031 
1032 /**
1033  * batadv_mcast_want_unsnoop_update() - update unsnoop counter and list
1034  * @bat_priv: the bat priv with all the soft interface information
1035  * @orig: the orig_node which multicast state might have changed of
1036  * @mcast_flags: flags indicating the new multicast state
1037  *
1038  * If the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag of this originator,
1039  * orig, has toggled then this method updates counter and list accordingly.
1040  *
1041  * Caller needs to hold orig->mcast_handler_lock.
1042  */
1043 static void batadv_mcast_want_unsnoop_update(struct batadv_priv *bat_priv,
1044 					     struct batadv_orig_node *orig,
1045 					     u8 mcast_flags)
1046 {
1047 	struct hlist_node *node = &orig->mcast_want_all_unsnoopables_node;
1048 	struct hlist_head *head = &bat_priv->mcast.want_all_unsnoopables_list;
1049 
1050 	lockdep_assert_held(&orig->mcast_handler_lock);
1051 
1052 	/* switched from flag unset to set */
1053 	if (mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
1054 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)) {
1055 		atomic_inc(&bat_priv->mcast.num_want_all_unsnoopables);
1056 
1057 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1058 		/* flag checks above + mcast_handler_lock prevents this */
1059 		WARN_ON(!hlist_unhashed(node));
1060 
1061 		hlist_add_head_rcu(node, head);
1062 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1063 	/* switched from flag set to unset */
1064 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) &&
1065 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) {
1066 		atomic_dec(&bat_priv->mcast.num_want_all_unsnoopables);
1067 
1068 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1069 		/* flag checks above + mcast_handler_lock prevents this */
1070 		WARN_ON(hlist_unhashed(node));
1071 
1072 		hlist_del_init_rcu(node);
1073 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1074 	}
1075 }
1076 
1077 /**
1078  * batadv_mcast_want_ipv4_update() - update want-all-ipv4 counter and list
1079  * @bat_priv: the bat priv with all the soft interface information
1080  * @orig: the orig_node which multicast state might have changed of
1081  * @mcast_flags: flags indicating the new multicast state
1082  *
1083  * If the BATADV_MCAST_WANT_ALL_IPV4 flag of this originator, orig, has
1084  * toggled then this method updates counter and list accordingly.
1085  *
1086  * Caller needs to hold orig->mcast_handler_lock.
1087  */
1088 static void batadv_mcast_want_ipv4_update(struct batadv_priv *bat_priv,
1089 					  struct batadv_orig_node *orig,
1090 					  u8 mcast_flags)
1091 {
1092 	struct hlist_node *node = &orig->mcast_want_all_ipv4_node;
1093 	struct hlist_head *head = &bat_priv->mcast.want_all_ipv4_list;
1094 
1095 	lockdep_assert_held(&orig->mcast_handler_lock);
1096 
1097 	/* switched from flag unset to set */
1098 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4 &&
1099 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)) {
1100 		atomic_inc(&bat_priv->mcast.num_want_all_ipv4);
1101 
1102 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1103 		/* flag checks above + mcast_handler_lock prevents this */
1104 		WARN_ON(!hlist_unhashed(node));
1105 
1106 		hlist_add_head_rcu(node, head);
1107 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1108 	/* switched from flag set to unset */
1109 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) &&
1110 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) {
1111 		atomic_dec(&bat_priv->mcast.num_want_all_ipv4);
1112 
1113 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1114 		/* flag checks above + mcast_handler_lock prevents this */
1115 		WARN_ON(hlist_unhashed(node));
1116 
1117 		hlist_del_init_rcu(node);
1118 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1119 	}
1120 }
1121 
1122 /**
1123  * batadv_mcast_want_ipv6_update() - update want-all-ipv6 counter and list
1124  * @bat_priv: the bat priv with all the soft interface information
1125  * @orig: the orig_node which multicast state might have changed of
1126  * @mcast_flags: flags indicating the new multicast state
1127  *
1128  * If the BATADV_MCAST_WANT_ALL_IPV6 flag of this originator, orig, has
1129  * toggled then this method updates counter and list accordingly.
1130  *
1131  * Caller needs to hold orig->mcast_handler_lock.
1132  */
1133 static void batadv_mcast_want_ipv6_update(struct batadv_priv *bat_priv,
1134 					  struct batadv_orig_node *orig,
1135 					  u8 mcast_flags)
1136 {
1137 	struct hlist_node *node = &orig->mcast_want_all_ipv6_node;
1138 	struct hlist_head *head = &bat_priv->mcast.want_all_ipv6_list;
1139 
1140 	lockdep_assert_held(&orig->mcast_handler_lock);
1141 
1142 	/* switched from flag unset to set */
1143 	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6 &&
1144 	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)) {
1145 		atomic_inc(&bat_priv->mcast.num_want_all_ipv6);
1146 
1147 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1148 		/* flag checks above + mcast_handler_lock prevents this */
1149 		WARN_ON(!hlist_unhashed(node));
1150 
1151 		hlist_add_head_rcu(node, head);
1152 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1153 	/* switched from flag set to unset */
1154 	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) &&
1155 		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) {
1156 		atomic_dec(&bat_priv->mcast.num_want_all_ipv6);
1157 
1158 		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
1159 		/* flag checks above + mcast_handler_lock prevents this */
1160 		WARN_ON(hlist_unhashed(node));
1161 
1162 		hlist_del_init_rcu(node);
1163 		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
1164 	}
1165 }
1166 
1167 /**
1168  * batadv_mcast_tvlv_ogm_handler() - process incoming multicast tvlv container
1169  * @bat_priv: the bat priv with all the soft interface information
1170  * @orig: the orig_node of the ogm
1171  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
1172  * @tvlv_value: tvlv buffer containing the multicast data
1173  * @tvlv_value_len: tvlv buffer length
1174  */
1175 static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv,
1176 					  struct batadv_orig_node *orig,
1177 					  u8 flags,
1178 					  void *tvlv_value,
1179 					  u16 tvlv_value_len)
1180 {
1181 	bool orig_mcast_enabled = !(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
1182 	u8 mcast_flags = BATADV_NO_FLAGS;
1183 
1184 	if (orig_mcast_enabled && tvlv_value &&
1185 	    tvlv_value_len >= sizeof(mcast_flags))
1186 		mcast_flags = *(u8 *)tvlv_value;
1187 
1188 	if (!orig_mcast_enabled) {
1189 		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV4;
1190 		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV6;
1191 	}
1192 
1193 	spin_lock_bh(&orig->mcast_handler_lock);
1194 
1195 	if (orig_mcast_enabled &&
1196 	    !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
1197 		set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
1198 	} else if (!orig_mcast_enabled &&
1199 		   test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
1200 		clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
1201 	}
1202 
1203 	set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized);
1204 
1205 	batadv_mcast_want_unsnoop_update(bat_priv, orig, mcast_flags);
1206 	batadv_mcast_want_ipv4_update(bat_priv, orig, mcast_flags);
1207 	batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
1208 
1209 	orig->mcast_flags = mcast_flags;
1210 	spin_unlock_bh(&orig->mcast_handler_lock);
1211 }
1212 
1213 /**
1214  * batadv_mcast_init() - initialize the multicast optimizations structures
1215  * @bat_priv: the bat priv with all the soft interface information
1216  */
1217 void batadv_mcast_init(struct batadv_priv *bat_priv)
1218 {
1219 	batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler,
1220 				     NULL, BATADV_TVLV_MCAST, 2,
1221 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
1222 
1223 	INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update);
1224 	batadv_mcast_start_timer(bat_priv);
1225 }
1226 
1227 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
1228 /**
1229  * batadv_mcast_flags_print_header() - print own mcast flags to debugfs table
1230  * @bat_priv: the bat priv with all the soft interface information
1231  * @seq: debugfs table seq_file struct
1232  *
1233  * Prints our own multicast flags including a more specific reason why
1234  * they are set, that is prints the bridge and querier state too, to
1235  * the debugfs table specified via @seq.
1236  */
1237 static void batadv_mcast_flags_print_header(struct batadv_priv *bat_priv,
1238 					    struct seq_file *seq)
1239 {
1240 	u8 flags = bat_priv->mcast.flags;
1241 	char querier4, querier6, shadowing4, shadowing6;
1242 	bool bridged = bat_priv->mcast.bridged;
1243 
1244 	if (bridged) {
1245 		querier4 = bat_priv->mcast.querier_ipv4.exists ? '.' : '4';
1246 		querier6 = bat_priv->mcast.querier_ipv6.exists ? '.' : '6';
1247 		shadowing4 = bat_priv->mcast.querier_ipv4.shadowing ? '4' : '.';
1248 		shadowing6 = bat_priv->mcast.querier_ipv6.shadowing ? '6' : '.';
1249 	} else {
1250 		querier4 = '?';
1251 		querier6 = '?';
1252 		shadowing4 = '?';
1253 		shadowing6 = '?';
1254 	}
1255 
1256 	seq_printf(seq, "Multicast flags (own flags: [%c%c%c])\n",
1257 		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
1258 		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
1259 		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
1260 	seq_printf(seq, "* Bridged [U]\t\t\t\t%c\n", bridged ? 'U' : '.');
1261 	seq_printf(seq, "* No IGMP/MLD Querier [4/6]:\t\t%c/%c\n",
1262 		   querier4, querier6);
1263 	seq_printf(seq, "* Shadowing IGMP/MLD Querier [4/6]:\t%c/%c\n",
1264 		   shadowing4, shadowing6);
1265 	seq_puts(seq, "-------------------------------------------\n");
1266 	seq_printf(seq, "       %-10s %s\n", "Originator", "Flags");
1267 }
1268 
1269 /**
1270  * batadv_mcast_flags_seq_print_text() - print the mcast flags of other nodes
1271  * @seq: seq file to print on
1272  * @offset: not used
1273  *
1274  * This prints a table of (primary) originators and their according
1275  * multicast flags, including (in the header) our own.
1276  *
1277  * Return: always 0
1278  */
1279 int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset)
1280 {
1281 	struct net_device *net_dev = (struct net_device *)seq->private;
1282 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
1283 	struct batadv_hard_iface *primary_if;
1284 	struct batadv_hashtable *hash = bat_priv->orig_hash;
1285 	struct batadv_orig_node *orig_node;
1286 	struct hlist_head *head;
1287 	u8 flags;
1288 	u32 i;
1289 
1290 	primary_if = batadv_seq_print_text_primary_if_get(seq);
1291 	if (!primary_if)
1292 		return 0;
1293 
1294 	batadv_mcast_flags_print_header(bat_priv, seq);
1295 
1296 	for (i = 0; i < hash->size; i++) {
1297 		head = &hash->table[i];
1298 
1299 		rcu_read_lock();
1300 		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1301 			if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
1302 				      &orig_node->capa_initialized))
1303 				continue;
1304 
1305 			if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
1306 				      &orig_node->capabilities)) {
1307 				seq_printf(seq, "%pM -\n", orig_node->orig);
1308 				continue;
1309 			}
1310 
1311 			flags = orig_node->mcast_flags;
1312 
1313 			seq_printf(seq, "%pM [%c%c%c]\n", orig_node->orig,
1314 				   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)
1315 				   ? 'U' : '.',
1316 				   (flags & BATADV_MCAST_WANT_ALL_IPV4)
1317 				   ? '4' : '.',
1318 				   (flags & BATADV_MCAST_WANT_ALL_IPV6)
1319 				   ? '6' : '.');
1320 		}
1321 		rcu_read_unlock();
1322 	}
1323 
1324 	batadv_hardif_put(primary_if);
1325 
1326 	return 0;
1327 }
1328 #endif
1329 
1330 /**
1331  * batadv_mcast_mesh_info_put() - put multicast info into a netlink message
1332  * @msg: buffer for the message
1333  * @bat_priv: the bat priv with all the soft interface information
1334  *
1335  * Return: 0 or error code.
1336  */
1337 int batadv_mcast_mesh_info_put(struct sk_buff *msg,
1338 			       struct batadv_priv *bat_priv)
1339 {
1340 	u32 flags = bat_priv->mcast.flags;
1341 	u32 flags_priv = BATADV_NO_FLAGS;
1342 
1343 	if (bat_priv->mcast.bridged) {
1344 		flags_priv |= BATADV_MCAST_FLAGS_BRIDGED;
1345 
1346 		if (bat_priv->mcast.querier_ipv4.exists)
1347 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_EXISTS;
1348 		if (bat_priv->mcast.querier_ipv6.exists)
1349 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_EXISTS;
1350 		if (bat_priv->mcast.querier_ipv4.shadowing)
1351 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_SHADOWING;
1352 		if (bat_priv->mcast.querier_ipv6.shadowing)
1353 			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING;
1354 	}
1355 
1356 	if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS, flags) ||
1357 	    nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS_PRIV, flags_priv))
1358 		return -EMSGSIZE;
1359 
1360 	return 0;
1361 }
1362 
1363 /**
1364  * batadv_mcast_flags_dump_entry() - dump one entry of the multicast flags table
1365  *  to a netlink socket
1366  * @msg: buffer for the message
1367  * @portid: netlink port
1368  * @seq: Sequence number of netlink message
1369  * @orig_node: originator to dump the multicast flags of
1370  *
1371  * Return: 0 or error code.
1372  */
1373 static int
1374 batadv_mcast_flags_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
1375 			      struct batadv_orig_node *orig_node)
1376 {
1377 	void *hdr;
1378 
1379 	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
1380 			  NLM_F_MULTI, BATADV_CMD_GET_MCAST_FLAGS);
1381 	if (!hdr)
1382 		return -ENOBUFS;
1383 
1384 	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
1385 		    orig_node->orig)) {
1386 		genlmsg_cancel(msg, hdr);
1387 		return -EMSGSIZE;
1388 	}
1389 
1390 	if (test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
1391 		     &orig_node->capabilities)) {
1392 		if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS,
1393 				orig_node->mcast_flags)) {
1394 			genlmsg_cancel(msg, hdr);
1395 			return -EMSGSIZE;
1396 		}
1397 	}
1398 
1399 	genlmsg_end(msg, hdr);
1400 	return 0;
1401 }
1402 
1403 /**
1404  * batadv_mcast_flags_dump_bucket() - dump one bucket of the multicast flags
1405  *  table to a netlink socket
1406  * @msg: buffer for the message
1407  * @portid: netlink port
1408  * @seq: Sequence number of netlink message
1409  * @head: bucket to dump
1410  * @idx_skip: How many entries to skip
1411  *
1412  * Return: 0 or error code.
1413  */
1414 static int
1415 batadv_mcast_flags_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
1416 			       struct hlist_head *head, long *idx_skip)
1417 {
1418 	struct batadv_orig_node *orig_node;
1419 	long idx = 0;
1420 
1421 	rcu_read_lock();
1422 	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1423 		if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
1424 			      &orig_node->capa_initialized))
1425 			continue;
1426 
1427 		if (idx < *idx_skip)
1428 			goto skip;
1429 
1430 		if (batadv_mcast_flags_dump_entry(msg, portid, seq,
1431 						  orig_node)) {
1432 			rcu_read_unlock();
1433 			*idx_skip = idx;
1434 
1435 			return -EMSGSIZE;
1436 		}
1437 
1438 skip:
1439 		idx++;
1440 	}
1441 	rcu_read_unlock();
1442 
1443 	return 0;
1444 }
1445 
1446 /**
1447  * __batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
1448  * @msg: buffer for the message
1449  * @portid: netlink port
1450  * @seq: Sequence number of netlink message
1451  * @bat_priv: the bat priv with all the soft interface information
1452  * @bucket: current bucket to dump
1453  * @idx: index in current bucket to the next entry to dump
1454  *
1455  * Return: 0 or error code.
1456  */
1457 static int
1458 __batadv_mcast_flags_dump(struct sk_buff *msg, u32 portid, u32 seq,
1459 			  struct batadv_priv *bat_priv, long *bucket, long *idx)
1460 {
1461 	struct batadv_hashtable *hash = bat_priv->orig_hash;
1462 	long bucket_tmp = *bucket;
1463 	struct hlist_head *head;
1464 	long idx_tmp = *idx;
1465 
1466 	while (bucket_tmp < hash->size) {
1467 		head = &hash->table[bucket_tmp];
1468 
1469 		if (batadv_mcast_flags_dump_bucket(msg, portid, seq, head,
1470 						   &idx_tmp))
1471 			break;
1472 
1473 		bucket_tmp++;
1474 		idx_tmp = 0;
1475 	}
1476 
1477 	*bucket = bucket_tmp;
1478 	*idx = idx_tmp;
1479 
1480 	return msg->len;
1481 }
1482 
1483 /**
1484  * batadv_mcast_netlink_get_primary() - get primary interface from netlink
1485  *  callback
1486  * @cb: netlink callback structure
1487  * @primary_if: the primary interface pointer to return the result in
1488  *
1489  * Return: 0 or error code.
1490  */
1491 static int
1492 batadv_mcast_netlink_get_primary(struct netlink_callback *cb,
1493 				 struct batadv_hard_iface **primary_if)
1494 {
1495 	struct batadv_hard_iface *hard_iface = NULL;
1496 	struct net *net = sock_net(cb->skb->sk);
1497 	struct net_device *soft_iface;
1498 	struct batadv_priv *bat_priv;
1499 	int ifindex;
1500 	int ret = 0;
1501 
1502 	ifindex = batadv_netlink_get_ifindex(cb->nlh, BATADV_ATTR_MESH_IFINDEX);
1503 	if (!ifindex)
1504 		return -EINVAL;
1505 
1506 	soft_iface = dev_get_by_index(net, ifindex);
1507 	if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
1508 		ret = -ENODEV;
1509 		goto out;
1510 	}
1511 
1512 	bat_priv = netdev_priv(soft_iface);
1513 
1514 	hard_iface = batadv_primary_if_get_selected(bat_priv);
1515 	if (!hard_iface || hard_iface->if_status != BATADV_IF_ACTIVE) {
1516 		ret = -ENOENT;
1517 		goto out;
1518 	}
1519 
1520 out:
1521 	if (soft_iface)
1522 		dev_put(soft_iface);
1523 
1524 	if (!ret && primary_if)
1525 		*primary_if = hard_iface;
1526 	else if (hard_iface)
1527 		batadv_hardif_put(hard_iface);
1528 
1529 	return ret;
1530 }
1531 
1532 /**
1533  * batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
1534  * @msg: buffer for the message
1535  * @cb: callback structure containing arguments
1536  *
1537  * Return: message length.
1538  */
1539 int batadv_mcast_flags_dump(struct sk_buff *msg, struct netlink_callback *cb)
1540 {
1541 	struct batadv_hard_iface *primary_if = NULL;
1542 	int portid = NETLINK_CB(cb->skb).portid;
1543 	struct batadv_priv *bat_priv;
1544 	long *bucket = &cb->args[0];
1545 	long *idx = &cb->args[1];
1546 	int ret;
1547 
1548 	ret = batadv_mcast_netlink_get_primary(cb, &primary_if);
1549 	if (ret)
1550 		return ret;
1551 
1552 	bat_priv = netdev_priv(primary_if->soft_iface);
1553 	ret = __batadv_mcast_flags_dump(msg, portid, cb->nlh->nlmsg_seq,
1554 					bat_priv, bucket, idx);
1555 
1556 	batadv_hardif_put(primary_if);
1557 	return ret;
1558 }
1559 
1560 /**
1561  * batadv_mcast_free() - free the multicast optimizations structures
1562  * @bat_priv: the bat priv with all the soft interface information
1563  */
1564 void batadv_mcast_free(struct batadv_priv *bat_priv)
1565 {
1566 	cancel_delayed_work_sync(&bat_priv->mcast.work);
1567 
1568 	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
1569 	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
1570 
1571 	/* safely calling outside of worker, as worker was canceled above */
1572 	batadv_mcast_mla_tt_retract(bat_priv, NULL);
1573 }
1574 
1575 /**
1576  * batadv_mcast_purge_orig() - reset originator global mcast state modifications
1577  * @orig: the originator which is going to get purged
1578  */
1579 void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
1580 {
1581 	struct batadv_priv *bat_priv = orig->bat_priv;
1582 
1583 	spin_lock_bh(&orig->mcast_handler_lock);
1584 
1585 	batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
1586 	batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS);
1587 	batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS);
1588 
1589 	spin_unlock_bh(&orig->mcast_handler_lock);
1590 }
1591