xref: /openbmc/linux/net/batman-adv/main.c (revision 9a29f5fc)
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/atomic.h>
10 #include <linux/build_bug.h>
11 #include <linux/byteorder/generic.h>
12 #include <linux/container_of.h>
13 #include <linux/crc32c.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/genetlink.h>
17 #include <linux/gfp.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_vlan.h>
20 #include <linux/init.h>
21 #include <linux/ip.h>
22 #include <linux/ipv6.h>
23 #include <linux/kernel.h>
24 #include <linux/kobject.h>
25 #include <linux/kref.h>
26 #include <linux/list.h>
27 #include <linux/minmax.h>
28 #include <linux/module.h>
29 #include <linux/netdevice.h>
30 #include <linux/printk.h>
31 #include <linux/rculist.h>
32 #include <linux/rcupdate.h>
33 #include <linux/skbuff.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.h>
36 #include <linux/stddef.h>
37 #include <linux/string.h>
38 #include <linux/workqueue.h>
39 #include <net/dsfield.h>
40 #include <net/rtnetlink.h>
41 #include <uapi/linux/batadv_packet.h>
42 #include <uapi/linux/batman_adv.h>
43 
44 #include "bat_algo.h"
45 #include "bat_iv_ogm.h"
46 #include "bat_v.h"
47 #include "bridge_loop_avoidance.h"
48 #include "distributed-arp-table.h"
49 #include "gateway_client.h"
50 #include "gateway_common.h"
51 #include "hard-interface.h"
52 #include "log.h"
53 #include "multicast.h"
54 #include "netlink.h"
55 #include "network-coding.h"
56 #include "originator.h"
57 #include "routing.h"
58 #include "send.h"
59 #include "soft-interface.h"
60 #include "tp_meter.h"
61 #include "translation-table.h"
62 
63 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
64  * list traversals just rcu-locked
65  */
66 struct list_head batadv_hardif_list;
67 unsigned int batadv_hardif_generation;
68 static int (*batadv_rx_handler[256])(struct sk_buff *skb,
69 				     struct batadv_hard_iface *recv_if);
70 
71 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
72 
73 struct workqueue_struct *batadv_event_workqueue;
74 
75 static void batadv_recv_handler_init(void);
76 
77 #define BATADV_UEV_TYPE_VAR	"BATTYPE="
78 #define BATADV_UEV_ACTION_VAR	"BATACTION="
79 #define BATADV_UEV_DATA_VAR	"BATDATA="
80 
81 static char *batadv_uev_action_str[] = {
82 	"add",
83 	"del",
84 	"change",
85 	"loopdetect",
86 };
87 
88 static char *batadv_uev_type_str[] = {
89 	"gw",
90 	"bla",
91 };
92 
93 static int __init batadv_init(void)
94 {
95 	int ret;
96 
97 	ret = batadv_tt_cache_init();
98 	if (ret < 0)
99 		return ret;
100 
101 	INIT_LIST_HEAD(&batadv_hardif_list);
102 	batadv_algo_init();
103 
104 	batadv_recv_handler_init();
105 
106 	batadv_v_init();
107 	batadv_iv_init();
108 	batadv_nc_init();
109 	batadv_tp_meter_init();
110 
111 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
112 	if (!batadv_event_workqueue)
113 		goto err_create_wq;
114 
115 	register_netdevice_notifier(&batadv_hard_if_notifier);
116 	rtnl_link_register(&batadv_link_ops);
117 	batadv_netlink_register();
118 
119 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
120 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
121 
122 	return 0;
123 
124 err_create_wq:
125 	batadv_tt_cache_destroy();
126 
127 	return -ENOMEM;
128 }
129 
130 static void __exit batadv_exit(void)
131 {
132 	batadv_netlink_unregister();
133 	rtnl_link_unregister(&batadv_link_ops);
134 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
135 
136 	destroy_workqueue(batadv_event_workqueue);
137 	batadv_event_workqueue = NULL;
138 
139 	rcu_barrier();
140 
141 	batadv_tt_cache_destroy();
142 }
143 
144 /**
145  * batadv_mesh_init() - Initialize soft interface
146  * @soft_iface: netdev struct of the soft interface
147  *
148  * Return: 0 on success or negative error number in case of failure
149  */
150 int batadv_mesh_init(struct net_device *soft_iface)
151 {
152 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
153 	int ret;
154 
155 	spin_lock_init(&bat_priv->forw_bat_list_lock);
156 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
157 	spin_lock_init(&bat_priv->tt.changes_list_lock);
158 	spin_lock_init(&bat_priv->tt.req_list_lock);
159 	spin_lock_init(&bat_priv->tt.roam_list_lock);
160 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
161 	spin_lock_init(&bat_priv->tt.commit_lock);
162 	spin_lock_init(&bat_priv->gw.list_lock);
163 #ifdef CONFIG_BATMAN_ADV_MCAST
164 	spin_lock_init(&bat_priv->mcast.mla_lock);
165 	spin_lock_init(&bat_priv->mcast.want_lists_lock);
166 #endif
167 	spin_lock_init(&bat_priv->tvlv.container_list_lock);
168 	spin_lock_init(&bat_priv->tvlv.handler_list_lock);
169 	spin_lock_init(&bat_priv->softif_vlan_list_lock);
170 	spin_lock_init(&bat_priv->tp_list_lock);
171 
172 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
173 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
174 	INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
175 #ifdef CONFIG_BATMAN_ADV_MCAST
176 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
177 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
178 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
179 #endif
180 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
181 	INIT_HLIST_HEAD(&bat_priv->tt.req_list);
182 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
183 #ifdef CONFIG_BATMAN_ADV_MCAST
184 	INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
185 #endif
186 	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
187 	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
188 	INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
189 	INIT_HLIST_HEAD(&bat_priv->tp_list);
190 
191 	bat_priv->gw.generation = 0;
192 
193 	ret = batadv_originator_init(bat_priv);
194 	if (ret < 0) {
195 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
196 		goto err_orig;
197 	}
198 
199 	ret = batadv_tt_init(bat_priv);
200 	if (ret < 0) {
201 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
202 		goto err_tt;
203 	}
204 
205 	ret = batadv_v_mesh_init(bat_priv);
206 	if (ret < 0) {
207 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
208 		goto err_v;
209 	}
210 
211 	ret = batadv_bla_init(bat_priv);
212 	if (ret < 0) {
213 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
214 		goto err_bla;
215 	}
216 
217 	ret = batadv_dat_init(bat_priv);
218 	if (ret < 0) {
219 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
220 		goto err_dat;
221 	}
222 
223 	ret = batadv_nc_mesh_init(bat_priv);
224 	if (ret < 0) {
225 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
226 		goto err_nc;
227 	}
228 
229 	batadv_gw_init(bat_priv);
230 	batadv_mcast_init(bat_priv);
231 
232 	atomic_set(&bat_priv->gw.reselect, 0);
233 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
234 
235 	return 0;
236 
237 err_nc:
238 	batadv_dat_free(bat_priv);
239 err_dat:
240 	batadv_bla_free(bat_priv);
241 err_bla:
242 	batadv_v_mesh_free(bat_priv);
243 err_v:
244 	batadv_tt_free(bat_priv);
245 err_tt:
246 	batadv_originator_free(bat_priv);
247 err_orig:
248 	batadv_purge_outstanding_packets(bat_priv, NULL);
249 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
250 
251 	return ret;
252 }
253 
254 /**
255  * batadv_mesh_free() - Deinitialize soft interface
256  * @soft_iface: netdev struct of the soft interface
257  */
258 void batadv_mesh_free(struct net_device *soft_iface)
259 {
260 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
261 
262 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
263 
264 	batadv_purge_outstanding_packets(bat_priv, NULL);
265 
266 	batadv_gw_node_free(bat_priv);
267 
268 	batadv_v_mesh_free(bat_priv);
269 	batadv_nc_mesh_free(bat_priv);
270 	batadv_dat_free(bat_priv);
271 	batadv_bla_free(bat_priv);
272 
273 	batadv_mcast_free(bat_priv);
274 
275 	/* Free the TT and the originator tables only after having terminated
276 	 * all the other depending components which may use these structures for
277 	 * their purposes.
278 	 */
279 	batadv_tt_free(bat_priv);
280 
281 	/* Since the originator table clean up routine is accessing the TT
282 	 * tables as well, it has to be invoked after the TT tables have been
283 	 * freed and marked as empty. This ensures that no cleanup RCU callbacks
284 	 * accessing the TT data are scheduled for later execution.
285 	 */
286 	batadv_originator_free(bat_priv);
287 
288 	batadv_gw_free(bat_priv);
289 
290 	free_percpu(bat_priv->bat_counters);
291 	bat_priv->bat_counters = NULL;
292 
293 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
294 }
295 
296 /**
297  * batadv_is_my_mac() - check if the given mac address belongs to any of the
298  *  real interfaces in the current mesh
299  * @bat_priv: the bat priv with all the soft interface information
300  * @addr: the address to check
301  *
302  * Return: 'true' if the mac address was found, false otherwise.
303  */
304 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
305 {
306 	const struct batadv_hard_iface *hard_iface;
307 	bool is_my_mac = false;
308 
309 	rcu_read_lock();
310 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
311 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
312 			continue;
313 
314 		if (hard_iface->soft_iface != bat_priv->soft_iface)
315 			continue;
316 
317 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
318 			is_my_mac = true;
319 			break;
320 		}
321 	}
322 	rcu_read_unlock();
323 	return is_my_mac;
324 }
325 
326 /**
327  * batadv_max_header_len() - calculate maximum encapsulation overhead for a
328  *  payload packet
329  *
330  * Return: the maximum encapsulation overhead in bytes.
331  */
332 int batadv_max_header_len(void)
333 {
334 	int header_len = 0;
335 
336 	header_len = max_t(int, header_len,
337 			   sizeof(struct batadv_unicast_packet));
338 	header_len = max_t(int, header_len,
339 			   sizeof(struct batadv_unicast_4addr_packet));
340 	header_len = max_t(int, header_len,
341 			   sizeof(struct batadv_bcast_packet));
342 
343 #ifdef CONFIG_BATMAN_ADV_NC
344 	header_len = max_t(int, header_len,
345 			   sizeof(struct batadv_coded_packet));
346 #endif
347 
348 	return header_len + ETH_HLEN;
349 }
350 
351 /**
352  * batadv_skb_set_priority() - sets skb priority according to packet content
353  * @skb: the packet to be sent
354  * @offset: offset to the packet content
355  *
356  * This function sets a value between 256 and 263 (802.1d priority), which
357  * can be interpreted by the cfg80211 or other drivers.
358  */
359 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
360 {
361 	struct iphdr ip_hdr_tmp, *ip_hdr;
362 	struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
363 	struct ethhdr ethhdr_tmp, *ethhdr;
364 	struct vlan_ethhdr *vhdr, vhdr_tmp;
365 	u32 prio;
366 
367 	/* already set, do nothing */
368 	if (skb->priority >= 256 && skb->priority <= 263)
369 		return;
370 
371 	ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
372 	if (!ethhdr)
373 		return;
374 
375 	switch (ethhdr->h_proto) {
376 	case htons(ETH_P_8021Q):
377 		vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
378 					  sizeof(*vhdr), &vhdr_tmp);
379 		if (!vhdr)
380 			return;
381 		prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
382 		prio = prio >> VLAN_PRIO_SHIFT;
383 		break;
384 	case htons(ETH_P_IP):
385 		ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
386 					    sizeof(*ip_hdr), &ip_hdr_tmp);
387 		if (!ip_hdr)
388 			return;
389 		prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
390 		break;
391 	case htons(ETH_P_IPV6):
392 		ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
393 					     sizeof(*ip6_hdr), &ip6_hdr_tmp);
394 		if (!ip6_hdr)
395 			return;
396 		prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
397 		break;
398 	default:
399 		return;
400 	}
401 
402 	skb->priority = prio + 256;
403 }
404 
405 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
406 					struct batadv_hard_iface *recv_if)
407 {
408 	kfree_skb(skb);
409 
410 	return NET_RX_DROP;
411 }
412 
413 /* incoming packets with the batman ethertype received on any active hard
414  * interface
415  */
416 
417 /**
418  * batadv_batman_skb_recv() - Handle incoming message from an hard interface
419  * @skb: the received packet
420  * @dev: the net device that the packet was received on
421  * @ptype: packet type of incoming packet (ETH_P_BATMAN)
422  * @orig_dev: the original receive net device (e.g. bonded device)
423  *
424  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
425  */
426 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
427 			   struct packet_type *ptype,
428 			   struct net_device *orig_dev)
429 {
430 	struct batadv_priv *bat_priv;
431 	struct batadv_ogm_packet *batadv_ogm_packet;
432 	struct batadv_hard_iface *hard_iface;
433 	u8 idx;
434 
435 	hard_iface = container_of(ptype, struct batadv_hard_iface,
436 				  batman_adv_ptype);
437 
438 	/* Prevent processing a packet received on an interface which is getting
439 	 * shut down otherwise the packet may trigger de-reference errors
440 	 * further down in the receive path.
441 	 */
442 	if (!kref_get_unless_zero(&hard_iface->refcount))
443 		goto err_out;
444 
445 	skb = skb_share_check(skb, GFP_ATOMIC);
446 
447 	/* skb was released by skb_share_check() */
448 	if (!skb)
449 		goto err_put;
450 
451 	/* packet should hold at least type and version */
452 	if (unlikely(!pskb_may_pull(skb, 2)))
453 		goto err_free;
454 
455 	/* expect a valid ethernet header here. */
456 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
457 		goto err_free;
458 
459 	if (!hard_iface->soft_iface)
460 		goto err_free;
461 
462 	bat_priv = netdev_priv(hard_iface->soft_iface);
463 
464 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
465 		goto err_free;
466 
467 	/* discard frames on not active interfaces */
468 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
469 		goto err_free;
470 
471 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
472 
473 	if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
474 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
475 			   "Drop packet: incompatible batman version (%i)\n",
476 			   batadv_ogm_packet->version);
477 		goto err_free;
478 	}
479 
480 	/* reset control block to avoid left overs from previous users */
481 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
482 
483 	idx = batadv_ogm_packet->packet_type;
484 	(*batadv_rx_handler[idx])(skb, hard_iface);
485 
486 	batadv_hardif_put(hard_iface);
487 
488 	/* return NET_RX_SUCCESS in any case as we
489 	 * most probably dropped the packet for
490 	 * routing-logical reasons.
491 	 */
492 	return NET_RX_SUCCESS;
493 
494 err_free:
495 	kfree_skb(skb);
496 err_put:
497 	batadv_hardif_put(hard_iface);
498 err_out:
499 	return NET_RX_DROP;
500 }
501 
502 static void batadv_recv_handler_init(void)
503 {
504 	int i;
505 
506 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
507 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
508 
509 	for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
510 		batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
511 
512 	/* compile time checks for sizes */
513 	BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
514 	BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
515 	BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
516 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
517 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
518 	BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
519 	BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
520 	BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
521 	BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
522 	BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
523 	BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
524 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
525 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
526 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
527 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
528 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
529 
530 	i = sizeof_field(struct sk_buff, cb);
531 	BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
532 
533 	/* broadcast packet */
534 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
535 
536 	/* unicast packets ... */
537 	/* unicast with 4 addresses packet */
538 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
539 	/* unicast packet */
540 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
541 	/* unicast tvlv packet */
542 	batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
543 	/* batman icmp packet */
544 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
545 	/* Fragmented packets */
546 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
547 }
548 
549 /**
550  * batadv_recv_handler_register() - Register handler for batman-adv packet type
551  * @packet_type: batadv_packettype which should be handled
552  * @recv_handler: receive handler for the packet type
553  *
554  * Return: 0 on success or negative error number in case of failure
555  */
556 int
557 batadv_recv_handler_register(u8 packet_type,
558 			     int (*recv_handler)(struct sk_buff *,
559 						 struct batadv_hard_iface *))
560 {
561 	int (*curr)(struct sk_buff *skb,
562 		    struct batadv_hard_iface *recv_if);
563 	curr = batadv_rx_handler[packet_type];
564 
565 	if (curr != batadv_recv_unhandled_packet &&
566 	    curr != batadv_recv_unhandled_unicast_packet)
567 		return -EBUSY;
568 
569 	batadv_rx_handler[packet_type] = recv_handler;
570 	return 0;
571 }
572 
573 /**
574  * batadv_recv_handler_unregister() - Unregister handler for packet type
575  * @packet_type: batadv_packettype which should no longer be handled
576  */
577 void batadv_recv_handler_unregister(u8 packet_type)
578 {
579 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
580 }
581 
582 /**
583  * batadv_skb_crc32() - calculate CRC32 of the whole packet and skip bytes in
584  *  the header
585  * @skb: skb pointing to fragmented socket buffers
586  * @payload_ptr: Pointer to position inside the head buffer of the skb
587  *  marking the start of the data to be CRC'ed
588  *
589  * payload_ptr must always point to an address in the skb head buffer and not to
590  * a fragment.
591  *
592  * Return: big endian crc32c of the checksummed data
593  */
594 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
595 {
596 	u32 crc = 0;
597 	unsigned int from;
598 	unsigned int to = skb->len;
599 	struct skb_seq_state st;
600 	const u8 *data;
601 	unsigned int len;
602 	unsigned int consumed = 0;
603 
604 	from = (unsigned int)(payload_ptr - skb->data);
605 
606 	skb_prepare_seq_read(skb, from, to, &st);
607 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
608 		crc = crc32c(crc, data, len);
609 		consumed += len;
610 	}
611 
612 	return htonl(crc);
613 }
614 
615 /**
616  * batadv_get_vid() - extract the VLAN identifier from skb if any
617  * @skb: the buffer containing the packet
618  * @header_len: length of the batman header preceding the ethernet header
619  *
620  * Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
621  * skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
622  */
623 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
624 {
625 	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
626 	struct vlan_ethhdr *vhdr;
627 	unsigned short vid;
628 
629 	if (ethhdr->h_proto != htons(ETH_P_8021Q))
630 		return BATADV_NO_FLAGS;
631 
632 	if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
633 		return BATADV_NO_FLAGS;
634 
635 	vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
636 	vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
637 	vid |= BATADV_VLAN_HAS_TAG;
638 
639 	return vid;
640 }
641 
642 /**
643  * batadv_vlan_ap_isola_get() - return AP isolation status for the given vlan
644  * @bat_priv: the bat priv with all the soft interface information
645  * @vid: the VLAN identifier for which the AP isolation attributed as to be
646  *  looked up
647  *
648  * Return: true if AP isolation is on for the VLAN identified by vid, false
649  * otherwise
650  */
651 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
652 {
653 	bool ap_isolation_enabled = false;
654 	struct batadv_softif_vlan *vlan;
655 
656 	/* if the AP isolation is requested on a VLAN, then check for its
657 	 * setting in the proper VLAN private data structure
658 	 */
659 	vlan = batadv_softif_vlan_get(bat_priv, vid);
660 	if (vlan) {
661 		ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
662 		batadv_softif_vlan_put(vlan);
663 	}
664 
665 	return ap_isolation_enabled;
666 }
667 
668 /**
669  * batadv_throw_uevent() - Send an uevent with batman-adv specific env data
670  * @bat_priv: the bat priv with all the soft interface information
671  * @type: subsystem type of event. Stored in uevent's BATTYPE
672  * @action: action type of event. Stored in uevent's BATACTION
673  * @data: string with additional information to the event (ignored for
674  *  BATADV_UEV_DEL). Stored in uevent's BATDATA
675  *
676  * Return: 0 on success or negative error number in case of failure
677  */
678 int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
679 			enum batadv_uev_action action, const char *data)
680 {
681 	int ret = -ENOMEM;
682 	struct kobject *bat_kobj;
683 	char *uevent_env[4] = { NULL, NULL, NULL, NULL };
684 
685 	bat_kobj = &bat_priv->soft_iface->dev.kobj;
686 
687 	uevent_env[0] = kasprintf(GFP_ATOMIC,
688 				  "%s%s", BATADV_UEV_TYPE_VAR,
689 				  batadv_uev_type_str[type]);
690 	if (!uevent_env[0])
691 		goto out;
692 
693 	uevent_env[1] = kasprintf(GFP_ATOMIC,
694 				  "%s%s", BATADV_UEV_ACTION_VAR,
695 				  batadv_uev_action_str[action]);
696 	if (!uevent_env[1])
697 		goto out;
698 
699 	/* If the event is DEL, ignore the data field */
700 	if (action != BATADV_UEV_DEL) {
701 		uevent_env[2] = kasprintf(GFP_ATOMIC,
702 					  "%s%s", BATADV_UEV_DATA_VAR, data);
703 		if (!uevent_env[2])
704 			goto out;
705 	}
706 
707 	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
708 out:
709 	kfree(uevent_env[0]);
710 	kfree(uevent_env[1]);
711 	kfree(uevent_env[2]);
712 
713 	if (ret)
714 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
715 			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
716 			   batadv_uev_type_str[type],
717 			   batadv_uev_action_str[action],
718 			   (action == BATADV_UEV_DEL ? "NULL" : data), ret);
719 	return ret;
720 }
721 
722 module_init(batadv_init);
723 module_exit(batadv_exit);
724 
725 MODULE_LICENSE("GPL");
726 
727 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
728 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
729 MODULE_VERSION(BATADV_SOURCE_VERSION);
730 MODULE_ALIAS_RTNL_LINK("batadv");
731 MODULE_ALIAS_GENL_FAMILY(BATADV_NL_NAME);
732