xref: /linux/net/batman-adv/main.c (revision 66182ca873a4e87b3496eca79d57f86b76d7f52d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner, Simon Wunderlich
5  */
6 
7 #include "main.h"
8 
9 #include <linux/array_size.h>
10 #include <linux/atomic.h>
11 #include <linux/build_bug.h>
12 #include <linux/byteorder/generic.h>
13 #include <linux/container_of.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/gfp.h>
17 #include <linux/if_ether.h>
18 #include <linux/if_vlan.h>
19 #include <linux/init.h>
20 #include <linux/ip.h>
21 #include <linux/ipv6.h>
22 #include <linux/kobject.h>
23 #include <linux/kref.h>
24 #include <linux/list.h>
25 #include <linux/minmax.h>
26 #include <linux/module.h>
27 #include <linux/netdevice.h>
28 #include <linux/printk.h>
29 #include <linux/rcupdate.h>
30 #include <linux/skbuff.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/sprintf.h>
34 #include <linux/stddef.h>
35 #include <linux/string.h>
36 #include <linux/workqueue.h>
37 #include <net/dsfield.h>
38 #include <net/genetlink.h>
39 #include <net/rtnetlink.h>
40 #include <uapi/linux/batadv_packet.h>
41 #include <uapi/linux/batman_adv.h>
42 
43 #include "bat_algo.h"
44 #include "bat_iv_ogm.h"
45 #include "bat_v.h"
46 #include "bridge_loop_avoidance.h"
47 #include "distributed-arp-table.h"
48 #include "gateway_client.h"
49 #include "gateway_common.h"
50 #include "hard-interface.h"
51 #include "log.h"
52 #include "mesh-interface.h"
53 #include "multicast.h"
54 #include "netlink.h"
55 #include "originator.h"
56 #include "routing.h"
57 #include "send.h"
58 #include "tp_meter.h"
59 #include "translation-table.h"
60 
61 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
62  * list traversals just rcu-locked
63  */
64 struct list_head batadv_hardif_list;
65 unsigned int batadv_hardif_generation;
66 static int (*batadv_rx_handler[256])(struct sk_buff *skb,
67 				     struct batadv_hard_iface *recv_if);
68 
69 struct workqueue_struct *batadv_event_workqueue;
70 
71 static void batadv_recv_handler_init(void);
72 
73 #define BATADV_UEV_TYPE_VAR	"BATTYPE="
74 #define BATADV_UEV_ACTION_VAR	"BATACTION="
75 #define BATADV_UEV_DATA_VAR	"BATDATA="
76 
77 static char *batadv_uev_action_str[] = {
78 	"add",
79 	"del",
80 	"change",
81 	"loopdetect",
82 };
83 
84 static char *batadv_uev_type_str[] = {
85 	"gw",
86 	"bla",
87 };
88 
batadv_init(void)89 static int __init batadv_init(void)
90 {
91 	int ret;
92 
93 	ret = batadv_tt_cache_init();
94 	if (ret < 0)
95 		return ret;
96 
97 	INIT_LIST_HEAD(&batadv_hardif_list);
98 	batadv_algo_init();
99 
100 	batadv_recv_handler_init();
101 
102 	batadv_v_init();
103 	batadv_iv_init();
104 	batadv_tp_meter_init();
105 
106 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
107 	if (!batadv_event_workqueue)
108 		goto err_create_wq;
109 
110 	register_netdevice_notifier(&batadv_hard_if_notifier);
111 	rtnl_link_register(&batadv_link_ops);
112 	batadv_netlink_register();
113 
114 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
115 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
116 
117 	return 0;
118 
119 err_create_wq:
120 	batadv_tt_cache_destroy();
121 
122 	return -ENOMEM;
123 }
124 
batadv_exit(void)125 static void __exit batadv_exit(void)
126 {
127 	batadv_netlink_unregister();
128 	rtnl_link_unregister(&batadv_link_ops);
129 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
130 
131 	destroy_workqueue(batadv_event_workqueue);
132 	batadv_event_workqueue = NULL;
133 
134 	rcu_barrier();
135 
136 	batadv_tt_cache_destroy();
137 }
138 
139 /**
140  * batadv_mesh_init() - Initialize mesh interface
141  * @mesh_iface: netdev struct of the mesh interface
142  *
143  * Return: 0 on success or negative error number in case of failure
144  */
batadv_mesh_init(struct net_device * mesh_iface)145 int batadv_mesh_init(struct net_device *mesh_iface)
146 {
147 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
148 	int ret;
149 
150 	spin_lock_init(&bat_priv->forw_bat_list_lock);
151 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
152 	spin_lock_init(&bat_priv->tt.changes_list_lock);
153 	spin_lock_init(&bat_priv->tt.req_list_lock);
154 	spin_lock_init(&bat_priv->tt.roam_list_lock);
155 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
156 	spin_lock_init(&bat_priv->tt.commit_lock);
157 	spin_lock_init(&bat_priv->gw.list_lock);
158 #ifdef CONFIG_BATMAN_ADV_MCAST
159 	spin_lock_init(&bat_priv->mcast.mla_lock);
160 	spin_lock_init(&bat_priv->mcast.want_lists_lock);
161 #endif
162 	spin_lock_init(&bat_priv->tvlv.container_list_lock);
163 	spin_lock_init(&bat_priv->tvlv.handler_list_lock);
164 	spin_lock_init(&bat_priv->meshif_vlan_list_lock);
165 	spin_lock_init(&bat_priv->tp_list_lock);
166 
167 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
168 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
169 	INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
170 #ifdef CONFIG_BATMAN_ADV_MCAST
171 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
172 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
173 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
174 #endif
175 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
176 	INIT_HLIST_HEAD(&bat_priv->tt.req_list);
177 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
178 #ifdef CONFIG_BATMAN_ADV_MCAST
179 	INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
180 #endif
181 	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
182 	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
183 	INIT_HLIST_HEAD(&bat_priv->meshif_vlan_list);
184 	INIT_HLIST_HEAD(&bat_priv->tp_list);
185 
186 	bat_priv->gw.generation = 0;
187 
188 	ret = batadv_originator_init(bat_priv);
189 	if (ret < 0) {
190 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
191 		goto err_orig;
192 	}
193 
194 	ret = batadv_tt_init(bat_priv);
195 	if (ret < 0) {
196 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
197 		goto err_tt;
198 	}
199 
200 	ret = batadv_v_mesh_init(bat_priv);
201 	if (ret < 0) {
202 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
203 		goto err_v;
204 	}
205 
206 	ret = batadv_bla_init(bat_priv);
207 	if (ret < 0) {
208 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
209 		goto err_bla;
210 	}
211 
212 	ret = batadv_dat_init(bat_priv);
213 	if (ret < 0) {
214 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
215 		goto err_dat;
216 	}
217 
218 	batadv_gw_init(bat_priv);
219 	batadv_mcast_init(bat_priv);
220 
221 	atomic_set(&bat_priv->gw.reselect, 0);
222 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
223 
224 	return 0;
225 
226 err_dat:
227 	batadv_bla_free(bat_priv);
228 err_bla:
229 	batadv_v_mesh_free(bat_priv);
230 err_v:
231 	batadv_tt_free(bat_priv);
232 err_tt:
233 	batadv_originator_free(bat_priv);
234 err_orig:
235 	batadv_purge_outstanding_packets(bat_priv, NULL);
236 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
237 
238 	return ret;
239 }
240 
241 /**
242  * batadv_mesh_free() - Deinitialize mesh interface
243  * @mesh_iface: netdev struct of the mesh interface
244  */
batadv_mesh_free(struct net_device * mesh_iface)245 void batadv_mesh_free(struct net_device *mesh_iface)
246 {
247 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
248 
249 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
250 
251 	batadv_purge_outstanding_packets(bat_priv, NULL);
252 	batadv_tp_stop_all(bat_priv);
253 
254 	batadv_gw_node_free(bat_priv);
255 
256 	batadv_v_mesh_free(bat_priv);
257 	batadv_dat_free(bat_priv);
258 	batadv_bla_free(bat_priv);
259 
260 	batadv_mcast_free(bat_priv);
261 
262 	/* Free the TT and the originator tables only after having terminated
263 	 * all the other depending components which may use these structures for
264 	 * their purposes.
265 	 */
266 	batadv_tt_free(bat_priv);
267 
268 	/* Since the originator table clean up routine is accessing the TT
269 	 * tables as well, it has to be invoked after the TT tables have been
270 	 * freed and marked as empty. This ensures that no cleanup RCU callbacks
271 	 * accessing the TT data are scheduled for later execution.
272 	 */
273 	batadv_originator_free(bat_priv);
274 
275 	batadv_gw_free(bat_priv);
276 
277 	free_percpu(bat_priv->bat_counters);
278 	bat_priv->bat_counters = NULL;
279 
280 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
281 }
282 
283 /**
284  * batadv_is_my_mac() - check if the given mac address belongs to any of the
285  *  real interfaces in the current mesh
286  * @bat_priv: the bat priv with all the mesh interface information
287  * @addr: the address to check
288  *
289  * Return: 'true' if the mac address was found, false otherwise.
290  */
batadv_is_my_mac(struct batadv_priv * bat_priv,const u8 * addr)291 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
292 {
293 	const struct batadv_hard_iface *hard_iface;
294 	struct list_head *iter;
295 	bool is_my_mac = false;
296 
297 	rcu_read_lock();
298 	netdev_for_each_lower_private_rcu(bat_priv->mesh_iface, hard_iface, iter) {
299 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
300 			continue;
301 
302 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
303 			is_my_mac = true;
304 			break;
305 		}
306 	}
307 	rcu_read_unlock();
308 	return is_my_mac;
309 }
310 
311 /**
312  * batadv_max_header_len() - calculate maximum encapsulation overhead for a
313  *  payload packet
314  *
315  * Return: the maximum encapsulation overhead in bytes.
316  */
batadv_max_header_len(void)317 int batadv_max_header_len(void)
318 {
319 	int header_len = 0;
320 
321 	header_len = max_t(int, header_len,
322 			   sizeof(struct batadv_unicast_packet));
323 	header_len = max_t(int, header_len,
324 			   sizeof(struct batadv_unicast_4addr_packet));
325 	header_len = max_t(int, header_len,
326 			   sizeof(struct batadv_bcast_packet));
327 
328 	return header_len + ETH_HLEN;
329 }
330 
331 /**
332  * batadv_skb_set_priority() - sets skb priority according to packet content
333  * @skb: the packet to be sent
334  * @offset: offset to the packet content
335  *
336  * This function sets a value between 256 and 263 (802.1d priority), which
337  * can be interpreted by the cfg80211 or other drivers.
338  */
batadv_skb_set_priority(struct sk_buff * skb,int offset)339 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
340 {
341 	struct iphdr ip_hdr_tmp, *ip_hdr;
342 	struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
343 	struct ethhdr ethhdr_tmp, *ethhdr;
344 	struct vlan_ethhdr *vhdr, vhdr_tmp;
345 	u32 prio;
346 
347 	/* already set, do nothing */
348 	if (skb->priority >= 256 && skb->priority <= 263)
349 		return;
350 
351 	ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
352 	if (!ethhdr)
353 		return;
354 
355 	switch (ethhdr->h_proto) {
356 	case htons(ETH_P_8021Q):
357 		vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
358 					  sizeof(*vhdr), &vhdr_tmp);
359 		if (!vhdr)
360 			return;
361 		prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
362 		prio = prio >> VLAN_PRIO_SHIFT;
363 		break;
364 	case htons(ETH_P_IP):
365 		ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
366 					    sizeof(*ip_hdr), &ip_hdr_tmp);
367 		if (!ip_hdr)
368 			return;
369 		prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
370 		break;
371 	case htons(ETH_P_IPV6):
372 		ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
373 					     sizeof(*ip6_hdr), &ip6_hdr_tmp);
374 		if (!ip6_hdr)
375 			return;
376 		prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
377 		break;
378 	default:
379 		return;
380 	}
381 
382 	skb->priority = prio + 256;
383 }
384 
batadv_recv_unhandled_packet(struct sk_buff * skb,struct batadv_hard_iface * recv_if)385 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
386 					struct batadv_hard_iface *recv_if)
387 {
388 	kfree_skb(skb);
389 
390 	return NET_RX_DROP;
391 }
392 
393 /* incoming packets with the batman ethertype received on any active hard
394  * interface
395  */
396 
397 /**
398  * batadv_batman_skb_recv() - Handle incoming message from an hard interface
399  * @skb: the received packet
400  * @dev: the net device that the packet was received on
401  * @ptype: packet type of incoming packet (ETH_P_BATMAN)
402  * @orig_dev: the original receive net device (e.g. bonded device)
403  *
404  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
405  */
batadv_batman_skb_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * ptype,struct net_device * orig_dev)406 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
407 			   struct packet_type *ptype,
408 			   struct net_device *orig_dev)
409 {
410 	struct batadv_priv *bat_priv;
411 	struct batadv_ogm_packet *batadv_ogm_packet;
412 	struct batadv_hard_iface *hard_iface;
413 	u8 idx;
414 
415 	hard_iface = container_of(ptype, struct batadv_hard_iface,
416 				  batman_adv_ptype);
417 
418 	/* Prevent processing a packet received on an interface which is getting
419 	 * shut down otherwise the packet may trigger de-reference errors
420 	 * further down in the receive path.
421 	 */
422 	if (!kref_get_unless_zero(&hard_iface->refcount))
423 		goto err_out;
424 
425 	skb = skb_share_check(skb, GFP_ATOMIC);
426 
427 	/* skb was released by skb_share_check() */
428 	if (!skb)
429 		goto err_put;
430 
431 	/* packet should hold at least type and version */
432 	if (unlikely(!pskb_may_pull(skb, 2)))
433 		goto err_free;
434 
435 	/* expect a valid ethernet header here. */
436 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
437 		goto err_free;
438 
439 	if (!hard_iface->mesh_iface)
440 		goto err_free;
441 
442 	bat_priv = netdev_priv(hard_iface->mesh_iface);
443 
444 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
445 		goto err_free;
446 
447 	/* discard frames on not active interfaces */
448 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
449 		goto err_free;
450 
451 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
452 
453 	if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
454 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
455 			   "Drop packet: incompatible batman version (%i)\n",
456 			   batadv_ogm_packet->version);
457 		goto err_free;
458 	}
459 
460 	/* reset control block to avoid left overs from previous users */
461 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
462 
463 	idx = batadv_ogm_packet->packet_type;
464 	(*batadv_rx_handler[idx])(skb, hard_iface);
465 
466 	batadv_hardif_put(hard_iface);
467 
468 	/* return NET_RX_SUCCESS in any case as we
469 	 * most probably dropped the packet for
470 	 * routing-logical reasons.
471 	 */
472 	return NET_RX_SUCCESS;
473 
474 err_free:
475 	kfree_skb(skb);
476 err_put:
477 	batadv_hardif_put(hard_iface);
478 err_out:
479 	return NET_RX_DROP;
480 }
481 
batadv_recv_handler_init(void)482 static void batadv_recv_handler_init(void)
483 {
484 	int i;
485 
486 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
487 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
488 
489 	for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
490 		batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
491 
492 	/* compile time checks for sizes */
493 	BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
494 	BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
495 	BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
496 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
497 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
498 	BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
499 	BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
500 	BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
501 	BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
502 	BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
503 	BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
504 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
505 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
506 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
507 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
508 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
509 
510 	i = sizeof_field(struct sk_buff, cb);
511 	BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
512 
513 	/* broadcast packet */
514 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
515 	/* multicast packet */
516 	batadv_rx_handler[BATADV_MCAST] = batadv_recv_mcast_packet;
517 
518 	/* unicast packets ... */
519 	/* unicast with 4 addresses packet */
520 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
521 	/* unicast packet */
522 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
523 	/* unicast tvlv packet */
524 	batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
525 	/* batman icmp packet */
526 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
527 	/* Fragmented packets */
528 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
529 }
530 
531 /**
532  * batadv_recv_handler_register() - Register handler for batman-adv packet type
533  * @packet_type: batadv_packettype which should be handled
534  * @recv_handler: receive handler for the packet type
535  *
536  * Return: 0 on success or negative error number in case of failure
537  */
538 int
batadv_recv_handler_register(u8 packet_type,int (* recv_handler)(struct sk_buff *,struct batadv_hard_iface *))539 batadv_recv_handler_register(u8 packet_type,
540 			     int (*recv_handler)(struct sk_buff *,
541 						 struct batadv_hard_iface *))
542 {
543 	int (*curr)(struct sk_buff *skb,
544 		    struct batadv_hard_iface *recv_if);
545 	curr = batadv_rx_handler[packet_type];
546 
547 	if (curr != batadv_recv_unhandled_packet &&
548 	    curr != batadv_recv_unhandled_unicast_packet)
549 		return -EBUSY;
550 
551 	batadv_rx_handler[packet_type] = recv_handler;
552 	return 0;
553 }
554 
555 /**
556  * batadv_recv_handler_unregister() - Unregister handler for packet type
557  * @packet_type: batadv_packettype which should no longer be handled
558  */
batadv_recv_handler_unregister(u8 packet_type)559 void batadv_recv_handler_unregister(u8 packet_type)
560 {
561 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
562 }
563 
564 /**
565  * batadv_get_vid() - extract the VLAN identifier from skb if any
566  * @skb: the buffer containing the packet
567  * @header_len: length of the batman header preceding the ethernet header
568  *
569  * Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
570  * skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
571  */
batadv_get_vid(struct sk_buff * skb,size_t header_len)572 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
573 {
574 	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
575 	struct vlan_ethhdr *vhdr;
576 	unsigned short vid;
577 
578 	if (ethhdr->h_proto != htons(ETH_P_8021Q))
579 		return BATADV_NO_FLAGS;
580 
581 	if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
582 		return BATADV_NO_FLAGS;
583 
584 	vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
585 	vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
586 
587 	/* VID 0 is only used to indicate "priority tag" frames which only
588 	 * contain priority information and no VID.
589 	 */
590 	if (vid == 0)
591 		return BATADV_NO_FLAGS;
592 
593 	vid |= BATADV_VLAN_HAS_TAG;
594 
595 	return vid;
596 }
597 
598 /**
599  * batadv_vlan_ap_isola_get() - return AP isolation status for the given vlan
600  * @bat_priv: the bat priv with all the mesh interface information
601  * @vid: the VLAN identifier for which the AP isolation attributed as to be
602  *  looked up
603  *
604  * Return: true if AP isolation is on for the VLAN identified by vid, false
605  * otherwise
606  */
batadv_vlan_ap_isola_get(struct batadv_priv * bat_priv,unsigned short vid)607 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
608 {
609 	bool ap_isolation_enabled = false;
610 	struct batadv_meshif_vlan *vlan;
611 
612 	/* if the AP isolation is requested on a VLAN, then check for its
613 	 * setting in the proper VLAN private data structure
614 	 */
615 	vlan = batadv_meshif_vlan_get(bat_priv, vid);
616 	if (vlan) {
617 		ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
618 		batadv_meshif_vlan_put(vlan);
619 	}
620 
621 	return ap_isolation_enabled;
622 }
623 
624 /**
625  * batadv_throw_uevent() - Send an uevent with batman-adv specific env data
626  * @bat_priv: the bat priv with all the mesh interface information
627  * @type: subsystem type of event. Stored in uevent's BATTYPE
628  * @action: action type of event. Stored in uevent's BATACTION
629  * @data: string with additional information to the event (ignored for
630  *  BATADV_UEV_DEL). Stored in uevent's BATDATA
631  *
632  * Return: 0 on success or negative error number in case of failure
633  */
batadv_throw_uevent(struct batadv_priv * bat_priv,enum batadv_uev_type type,enum batadv_uev_action action,const char * data)634 int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
635 			enum batadv_uev_action action, const char *data)
636 {
637 	int ret = -ENOMEM;
638 	struct kobject *bat_kobj;
639 	char *uevent_env[4] = { NULL, NULL, NULL, NULL };
640 
641 	bat_kobj = &bat_priv->mesh_iface->dev.kobj;
642 
643 	uevent_env[0] = kasprintf(GFP_ATOMIC,
644 				  "%s%s", BATADV_UEV_TYPE_VAR,
645 				  batadv_uev_type_str[type]);
646 	if (!uevent_env[0])
647 		goto report_error;
648 
649 	uevent_env[1] = kasprintf(GFP_ATOMIC,
650 				  "%s%s", BATADV_UEV_ACTION_VAR,
651 				  batadv_uev_action_str[action]);
652 	if (!uevent_env[1])
653 		goto free_first_env;
654 
655 	/* If the event is DEL, ignore the data field */
656 	if (action != BATADV_UEV_DEL) {
657 		uevent_env[2] = kasprintf(GFP_ATOMIC,
658 					  "%s%s", BATADV_UEV_DATA_VAR, data);
659 		if (!uevent_env[2])
660 			goto free_second_env;
661 	}
662 
663 	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
664 	kfree(uevent_env[2]);
665 free_second_env:
666 	kfree(uevent_env[1]);
667 free_first_env:
668 	kfree(uevent_env[0]);
669 
670 	if (ret)
671 report_error:
672 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
673 			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
674 			   batadv_uev_type_str[type],
675 			   batadv_uev_action_str[action],
676 			   (action == BATADV_UEV_DEL ? "NULL" : data), ret);
677 	return ret;
678 }
679 
680 module_init(batadv_init);
681 module_exit(batadv_exit);
682 
683 MODULE_LICENSE("GPL");
684 
685 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
686 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
687 MODULE_VERSION(BATADV_SOURCE_VERSION);
688 MODULE_ALIAS_RTNL_LINK("batadv");
689 MODULE_ALIAS_GENL_FAMILY(BATADV_NL_NAME);
690