xref: /linux/net/batman-adv/main.c (revision 621cde16e49b3ecf7d59a8106a20aaebfb4a59a9)
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/crc32c.h>
15 #include <linux/device.h>
16 #include <linux/errno.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/kobject.h>
24 #include <linux/kref.h>
25 #include <linux/list.h>
26 #include <linux/minmax.h>
27 #include <linux/module.h>
28 #include <linux/netdevice.h>
29 #include <linux/printk.h>
30 #include <linux/rculist.h>
31 #include <linux/rcupdate.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/sprintf.h>
36 #include <linux/stddef.h>
37 #include <linux/string.h>
38 #include <linux/workqueue.h>
39 #include <net/dsfield.h>
40 #include <net/genetlink.h>
41 #include <net/rtnetlink.h>
42 #include <uapi/linux/batadv_packet.h>
43 #include <uapi/linux/batman_adv.h>
44 
45 #include "bat_algo.h"
46 #include "bat_iv_ogm.h"
47 #include "bat_v.h"
48 #include "bridge_loop_avoidance.h"
49 #include "distributed-arp-table.h"
50 #include "gateway_client.h"
51 #include "gateway_common.h"
52 #include "hard-interface.h"
53 #include "log.h"
54 #include "multicast.h"
55 #include "netlink.h"
56 #include "network-coding.h"
57 #include "originator.h"
58 #include "routing.h"
59 #include "send.h"
60 #include "soft-interface.h"
61 #include "tp_meter.h"
62 #include "translation-table.h"
63 
64 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
65  * list traversals just rcu-locked
66  */
67 struct list_head batadv_hardif_list;
68 unsigned int batadv_hardif_generation;
69 static int (*batadv_rx_handler[256])(struct sk_buff *skb,
70 				     struct batadv_hard_iface *recv_if);
71 
72 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
73 
74 struct workqueue_struct *batadv_event_workqueue;
75 
76 static void batadv_recv_handler_init(void);
77 
78 #define BATADV_UEV_TYPE_VAR	"BATTYPE="
79 #define BATADV_UEV_ACTION_VAR	"BATACTION="
80 #define BATADV_UEV_DATA_VAR	"BATDATA="
81 
82 static char *batadv_uev_action_str[] = {
83 	"add",
84 	"del",
85 	"change",
86 	"loopdetect",
87 };
88 
89 static char *batadv_uev_type_str[] = {
90 	"gw",
91 	"bla",
92 };
93 
batadv_init(void)94 static int __init batadv_init(void)
95 {
96 	int ret;
97 
98 	ret = batadv_tt_cache_init();
99 	if (ret < 0)
100 		return ret;
101 
102 	INIT_LIST_HEAD(&batadv_hardif_list);
103 	batadv_algo_init();
104 
105 	batadv_recv_handler_init();
106 
107 	batadv_v_init();
108 	batadv_iv_init();
109 	batadv_nc_init();
110 	batadv_tp_meter_init();
111 
112 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
113 	if (!batadv_event_workqueue)
114 		goto err_create_wq;
115 
116 	register_netdevice_notifier(&batadv_hard_if_notifier);
117 	rtnl_link_register(&batadv_link_ops);
118 	batadv_netlink_register();
119 
120 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
121 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
122 
123 	return 0;
124 
125 err_create_wq:
126 	batadv_tt_cache_destroy();
127 
128 	return -ENOMEM;
129 }
130 
batadv_exit(void)131 static void __exit batadv_exit(void)
132 {
133 	batadv_netlink_unregister();
134 	rtnl_link_unregister(&batadv_link_ops);
135 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
136 
137 	destroy_workqueue(batadv_event_workqueue);
138 	batadv_event_workqueue = NULL;
139 
140 	rcu_barrier();
141 
142 	batadv_tt_cache_destroy();
143 }
144 
145 /**
146  * batadv_mesh_init() - Initialize soft interface
147  * @soft_iface: netdev struct of the soft interface
148  *
149  * Return: 0 on success or negative error number in case of failure
150  */
batadv_mesh_init(struct net_device * soft_iface)151 int batadv_mesh_init(struct net_device *soft_iface)
152 {
153 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
154 	int ret;
155 
156 	spin_lock_init(&bat_priv->forw_bat_list_lock);
157 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
158 	spin_lock_init(&bat_priv->tt.changes_list_lock);
159 	spin_lock_init(&bat_priv->tt.req_list_lock);
160 	spin_lock_init(&bat_priv->tt.roam_list_lock);
161 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
162 	spin_lock_init(&bat_priv->tt.commit_lock);
163 	spin_lock_init(&bat_priv->gw.list_lock);
164 #ifdef CONFIG_BATMAN_ADV_MCAST
165 	spin_lock_init(&bat_priv->mcast.mla_lock);
166 	spin_lock_init(&bat_priv->mcast.want_lists_lock);
167 #endif
168 	spin_lock_init(&bat_priv->tvlv.container_list_lock);
169 	spin_lock_init(&bat_priv->tvlv.handler_list_lock);
170 	spin_lock_init(&bat_priv->softif_vlan_list_lock);
171 	spin_lock_init(&bat_priv->tp_list_lock);
172 
173 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
174 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
175 	INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
176 #ifdef CONFIG_BATMAN_ADV_MCAST
177 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
178 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
179 	INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
180 #endif
181 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
182 	INIT_HLIST_HEAD(&bat_priv->tt.req_list);
183 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
184 #ifdef CONFIG_BATMAN_ADV_MCAST
185 	INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
186 #endif
187 	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
188 	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
189 	INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
190 	INIT_HLIST_HEAD(&bat_priv->tp_list);
191 
192 	bat_priv->gw.generation = 0;
193 
194 	ret = batadv_originator_init(bat_priv);
195 	if (ret < 0) {
196 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
197 		goto err_orig;
198 	}
199 
200 	ret = batadv_tt_init(bat_priv);
201 	if (ret < 0) {
202 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
203 		goto err_tt;
204 	}
205 
206 	ret = batadv_v_mesh_init(bat_priv);
207 	if (ret < 0) {
208 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
209 		goto err_v;
210 	}
211 
212 	ret = batadv_bla_init(bat_priv);
213 	if (ret < 0) {
214 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
215 		goto err_bla;
216 	}
217 
218 	ret = batadv_dat_init(bat_priv);
219 	if (ret < 0) {
220 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
221 		goto err_dat;
222 	}
223 
224 	ret = batadv_nc_mesh_init(bat_priv);
225 	if (ret < 0) {
226 		atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
227 		goto err_nc;
228 	}
229 
230 	batadv_gw_init(bat_priv);
231 	batadv_mcast_init(bat_priv);
232 
233 	atomic_set(&bat_priv->gw.reselect, 0);
234 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
235 
236 	return 0;
237 
238 err_nc:
239 	batadv_dat_free(bat_priv);
240 err_dat:
241 	batadv_bla_free(bat_priv);
242 err_bla:
243 	batadv_v_mesh_free(bat_priv);
244 err_v:
245 	batadv_tt_free(bat_priv);
246 err_tt:
247 	batadv_originator_free(bat_priv);
248 err_orig:
249 	batadv_purge_outstanding_packets(bat_priv, NULL);
250 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
251 
252 	return ret;
253 }
254 
255 /**
256  * batadv_mesh_free() - Deinitialize soft interface
257  * @soft_iface: netdev struct of the soft interface
258  */
batadv_mesh_free(struct net_device * soft_iface)259 void batadv_mesh_free(struct net_device *soft_iface)
260 {
261 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
262 
263 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
264 
265 	batadv_purge_outstanding_packets(bat_priv, NULL);
266 
267 	batadv_gw_node_free(bat_priv);
268 
269 	batadv_v_mesh_free(bat_priv);
270 	batadv_nc_mesh_free(bat_priv);
271 	batadv_dat_free(bat_priv);
272 	batadv_bla_free(bat_priv);
273 
274 	batadv_mcast_free(bat_priv);
275 
276 	/* Free the TT and the originator tables only after having terminated
277 	 * all the other depending components which may use these structures for
278 	 * their purposes.
279 	 */
280 	batadv_tt_free(bat_priv);
281 
282 	/* Since the originator table clean up routine is accessing the TT
283 	 * tables as well, it has to be invoked after the TT tables have been
284 	 * freed and marked as empty. This ensures that no cleanup RCU callbacks
285 	 * accessing the TT data are scheduled for later execution.
286 	 */
287 	batadv_originator_free(bat_priv);
288 
289 	batadv_gw_free(bat_priv);
290 
291 	free_percpu(bat_priv->bat_counters);
292 	bat_priv->bat_counters = NULL;
293 
294 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
295 }
296 
297 /**
298  * batadv_is_my_mac() - check if the given mac address belongs to any of the
299  *  real interfaces in the current mesh
300  * @bat_priv: the bat priv with all the soft interface information
301  * @addr: the address to check
302  *
303  * Return: 'true' if the mac address was found, false otherwise.
304  */
batadv_is_my_mac(struct batadv_priv * bat_priv,const u8 * addr)305 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
306 {
307 	const struct batadv_hard_iface *hard_iface;
308 	bool is_my_mac = false;
309 
310 	rcu_read_lock();
311 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
312 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
313 			continue;
314 
315 		if (hard_iface->soft_iface != bat_priv->soft_iface)
316 			continue;
317 
318 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
319 			is_my_mac = true;
320 			break;
321 		}
322 	}
323 	rcu_read_unlock();
324 	return is_my_mac;
325 }
326 
327 /**
328  * batadv_max_header_len() - calculate maximum encapsulation overhead for a
329  *  payload packet
330  *
331  * Return: the maximum encapsulation overhead in bytes.
332  */
batadv_max_header_len(void)333 int batadv_max_header_len(void)
334 {
335 	int header_len = 0;
336 
337 	header_len = max_t(int, header_len,
338 			   sizeof(struct batadv_unicast_packet));
339 	header_len = max_t(int, header_len,
340 			   sizeof(struct batadv_unicast_4addr_packet));
341 	header_len = max_t(int, header_len,
342 			   sizeof(struct batadv_bcast_packet));
343 
344 #ifdef CONFIG_BATMAN_ADV_NC
345 	header_len = max_t(int, header_len,
346 			   sizeof(struct batadv_coded_packet));
347 #endif
348 
349 	return header_len + ETH_HLEN;
350 }
351 
352 /**
353  * batadv_skb_set_priority() - sets skb priority according to packet content
354  * @skb: the packet to be sent
355  * @offset: offset to the packet content
356  *
357  * This function sets a value between 256 and 263 (802.1d priority), which
358  * can be interpreted by the cfg80211 or other drivers.
359  */
batadv_skb_set_priority(struct sk_buff * skb,int offset)360 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
361 {
362 	struct iphdr ip_hdr_tmp, *ip_hdr;
363 	struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
364 	struct ethhdr ethhdr_tmp, *ethhdr;
365 	struct vlan_ethhdr *vhdr, vhdr_tmp;
366 	u32 prio;
367 
368 	/* already set, do nothing */
369 	if (skb->priority >= 256 && skb->priority <= 263)
370 		return;
371 
372 	ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
373 	if (!ethhdr)
374 		return;
375 
376 	switch (ethhdr->h_proto) {
377 	case htons(ETH_P_8021Q):
378 		vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
379 					  sizeof(*vhdr), &vhdr_tmp);
380 		if (!vhdr)
381 			return;
382 		prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
383 		prio = prio >> VLAN_PRIO_SHIFT;
384 		break;
385 	case htons(ETH_P_IP):
386 		ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
387 					    sizeof(*ip_hdr), &ip_hdr_tmp);
388 		if (!ip_hdr)
389 			return;
390 		prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
391 		break;
392 	case htons(ETH_P_IPV6):
393 		ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
394 					     sizeof(*ip6_hdr), &ip6_hdr_tmp);
395 		if (!ip6_hdr)
396 			return;
397 		prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
398 		break;
399 	default:
400 		return;
401 	}
402 
403 	skb->priority = prio + 256;
404 }
405 
batadv_recv_unhandled_packet(struct sk_buff * skb,struct batadv_hard_iface * recv_if)406 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
407 					struct batadv_hard_iface *recv_if)
408 {
409 	kfree_skb(skb);
410 
411 	return NET_RX_DROP;
412 }
413 
414 /* incoming packets with the batman ethertype received on any active hard
415  * interface
416  */
417 
418 /**
419  * batadv_batman_skb_recv() - Handle incoming message from an hard interface
420  * @skb: the received packet
421  * @dev: the net device that the packet was received on
422  * @ptype: packet type of incoming packet (ETH_P_BATMAN)
423  * @orig_dev: the original receive net device (e.g. bonded device)
424  *
425  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
426  */
batadv_batman_skb_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * ptype,struct net_device * orig_dev)427 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
428 			   struct packet_type *ptype,
429 			   struct net_device *orig_dev)
430 {
431 	struct batadv_priv *bat_priv;
432 	struct batadv_ogm_packet *batadv_ogm_packet;
433 	struct batadv_hard_iface *hard_iface;
434 	u8 idx;
435 
436 	hard_iface = container_of(ptype, struct batadv_hard_iface,
437 				  batman_adv_ptype);
438 
439 	/* Prevent processing a packet received on an interface which is getting
440 	 * shut down otherwise the packet may trigger de-reference errors
441 	 * further down in the receive path.
442 	 */
443 	if (!kref_get_unless_zero(&hard_iface->refcount))
444 		goto err_out;
445 
446 	skb = skb_share_check(skb, GFP_ATOMIC);
447 
448 	/* skb was released by skb_share_check() */
449 	if (!skb)
450 		goto err_put;
451 
452 	/* packet should hold at least type and version */
453 	if (unlikely(!pskb_may_pull(skb, 2)))
454 		goto err_free;
455 
456 	/* expect a valid ethernet header here. */
457 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
458 		goto err_free;
459 
460 	if (!hard_iface->soft_iface)
461 		goto err_free;
462 
463 	bat_priv = netdev_priv(hard_iface->soft_iface);
464 
465 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
466 		goto err_free;
467 
468 	/* discard frames on not active interfaces */
469 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
470 		goto err_free;
471 
472 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
473 
474 	if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
475 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
476 			   "Drop packet: incompatible batman version (%i)\n",
477 			   batadv_ogm_packet->version);
478 		goto err_free;
479 	}
480 
481 	/* reset control block to avoid left overs from previous users */
482 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
483 
484 	idx = batadv_ogm_packet->packet_type;
485 	(*batadv_rx_handler[idx])(skb, hard_iface);
486 
487 	batadv_hardif_put(hard_iface);
488 
489 	/* return NET_RX_SUCCESS in any case as we
490 	 * most probably dropped the packet for
491 	 * routing-logical reasons.
492 	 */
493 	return NET_RX_SUCCESS;
494 
495 err_free:
496 	kfree_skb(skb);
497 err_put:
498 	batadv_hardif_put(hard_iface);
499 err_out:
500 	return NET_RX_DROP;
501 }
502 
batadv_recv_handler_init(void)503 static void batadv_recv_handler_init(void)
504 {
505 	int i;
506 
507 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
508 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
509 
510 	for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
511 		batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
512 
513 	/* compile time checks for sizes */
514 	BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
515 	BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
516 	BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
517 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
518 	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
519 	BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
520 	BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
521 	BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
522 	BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
523 	BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
524 	BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
525 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
526 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
527 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
528 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
529 	BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
530 
531 	i = sizeof_field(struct sk_buff, cb);
532 	BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
533 
534 	/* broadcast packet */
535 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
536 	/* multicast packet */
537 	batadv_rx_handler[BATADV_MCAST] = batadv_recv_mcast_packet;
538 
539 	/* unicast packets ... */
540 	/* unicast with 4 addresses packet */
541 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
542 	/* unicast packet */
543 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
544 	/* unicast tvlv packet */
545 	batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
546 	/* batman icmp packet */
547 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
548 	/* Fragmented packets */
549 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
550 }
551 
552 /**
553  * batadv_recv_handler_register() - Register handler for batman-adv packet type
554  * @packet_type: batadv_packettype which should be handled
555  * @recv_handler: receive handler for the packet type
556  *
557  * Return: 0 on success or negative error number in case of failure
558  */
559 int
batadv_recv_handler_register(u8 packet_type,int (* recv_handler)(struct sk_buff *,struct batadv_hard_iface *))560 batadv_recv_handler_register(u8 packet_type,
561 			     int (*recv_handler)(struct sk_buff *,
562 						 struct batadv_hard_iface *))
563 {
564 	int (*curr)(struct sk_buff *skb,
565 		    struct batadv_hard_iface *recv_if);
566 	curr = batadv_rx_handler[packet_type];
567 
568 	if (curr != batadv_recv_unhandled_packet &&
569 	    curr != batadv_recv_unhandled_unicast_packet)
570 		return -EBUSY;
571 
572 	batadv_rx_handler[packet_type] = recv_handler;
573 	return 0;
574 }
575 
576 /**
577  * batadv_recv_handler_unregister() - Unregister handler for packet type
578  * @packet_type: batadv_packettype which should no longer be handled
579  */
batadv_recv_handler_unregister(u8 packet_type)580 void batadv_recv_handler_unregister(u8 packet_type)
581 {
582 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
583 }
584 
585 /**
586  * batadv_skb_crc32() - calculate CRC32 of the whole packet and skip bytes in
587  *  the header
588  * @skb: skb pointing to fragmented socket buffers
589  * @payload_ptr: Pointer to position inside the head buffer of the skb
590  *  marking the start of the data to be CRC'ed
591  *
592  * payload_ptr must always point to an address in the skb head buffer and not to
593  * a fragment.
594  *
595  * Return: big endian crc32c of the checksummed data
596  */
batadv_skb_crc32(struct sk_buff * skb,u8 * payload_ptr)597 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
598 {
599 	u32 crc = 0;
600 	unsigned int from;
601 	unsigned int to = skb->len;
602 	struct skb_seq_state st;
603 	const u8 *data;
604 	unsigned int len;
605 	unsigned int consumed = 0;
606 
607 	from = (unsigned int)(payload_ptr - skb->data);
608 
609 	skb_prepare_seq_read(skb, from, to, &st);
610 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
611 		crc = crc32c(crc, data, len);
612 		consumed += len;
613 	}
614 
615 	return htonl(crc);
616 }
617 
618 /**
619  * batadv_get_vid() - extract the VLAN identifier from skb if any
620  * @skb: the buffer containing the packet
621  * @header_len: length of the batman header preceding the ethernet header
622  *
623  * Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
624  * skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
625  */
batadv_get_vid(struct sk_buff * skb,size_t header_len)626 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
627 {
628 	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
629 	struct vlan_ethhdr *vhdr;
630 	unsigned short vid;
631 
632 	if (ethhdr->h_proto != htons(ETH_P_8021Q))
633 		return BATADV_NO_FLAGS;
634 
635 	if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
636 		return BATADV_NO_FLAGS;
637 
638 	vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
639 	vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
640 	vid |= BATADV_VLAN_HAS_TAG;
641 
642 	return vid;
643 }
644 
645 /**
646  * batadv_vlan_ap_isola_get() - return AP isolation status for the given vlan
647  * @bat_priv: the bat priv with all the soft interface information
648  * @vid: the VLAN identifier for which the AP isolation attributed as to be
649  *  looked up
650  *
651  * Return: true if AP isolation is on for the VLAN identified by vid, false
652  * otherwise
653  */
batadv_vlan_ap_isola_get(struct batadv_priv * bat_priv,unsigned short vid)654 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
655 {
656 	bool ap_isolation_enabled = false;
657 	struct batadv_softif_vlan *vlan;
658 
659 	/* if the AP isolation is requested on a VLAN, then check for its
660 	 * setting in the proper VLAN private data structure
661 	 */
662 	vlan = batadv_softif_vlan_get(bat_priv, vid);
663 	if (vlan) {
664 		ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
665 		batadv_softif_vlan_put(vlan);
666 	}
667 
668 	return ap_isolation_enabled;
669 }
670 
671 /**
672  * batadv_throw_uevent() - Send an uevent with batman-adv specific env data
673  * @bat_priv: the bat priv with all the soft interface information
674  * @type: subsystem type of event. Stored in uevent's BATTYPE
675  * @action: action type of event. Stored in uevent's BATACTION
676  * @data: string with additional information to the event (ignored for
677  *  BATADV_UEV_DEL). Stored in uevent's BATDATA
678  *
679  * Return: 0 on success or negative error number in case of failure
680  */
batadv_throw_uevent(struct batadv_priv * bat_priv,enum batadv_uev_type type,enum batadv_uev_action action,const char * data)681 int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
682 			enum batadv_uev_action action, const char *data)
683 {
684 	int ret = -ENOMEM;
685 	struct kobject *bat_kobj;
686 	char *uevent_env[4] = { NULL, NULL, NULL, NULL };
687 
688 	bat_kobj = &bat_priv->soft_iface->dev.kobj;
689 
690 	uevent_env[0] = kasprintf(GFP_ATOMIC,
691 				  "%s%s", BATADV_UEV_TYPE_VAR,
692 				  batadv_uev_type_str[type]);
693 	if (!uevent_env[0])
694 		goto report_error;
695 
696 	uevent_env[1] = kasprintf(GFP_ATOMIC,
697 				  "%s%s", BATADV_UEV_ACTION_VAR,
698 				  batadv_uev_action_str[action]);
699 	if (!uevent_env[1])
700 		goto free_first_env;
701 
702 	/* If the event is DEL, ignore the data field */
703 	if (action != BATADV_UEV_DEL) {
704 		uevent_env[2] = kasprintf(GFP_ATOMIC,
705 					  "%s%s", BATADV_UEV_DATA_VAR, data);
706 		if (!uevent_env[2])
707 			goto free_second_env;
708 	}
709 
710 	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
711 	kfree(uevent_env[2]);
712 free_second_env:
713 	kfree(uevent_env[1]);
714 free_first_env:
715 	kfree(uevent_env[0]);
716 
717 	if (ret)
718 report_error:
719 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
720 			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
721 			   batadv_uev_type_str[type],
722 			   batadv_uev_action_str[action],
723 			   (action == BATADV_UEV_DEL ? "NULL" : data), ret);
724 	return ret;
725 }
726 
727 module_init(batadv_init);
728 module_exit(batadv_exit);
729 
730 MODULE_LICENSE("GPL");
731 
732 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
733 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
734 MODULE_VERSION(BATADV_SOURCE_VERSION);
735 MODULE_ALIAS_RTNL_LINK("batadv");
736 MODULE_ALIAS_GENL_FAMILY(BATADV_NL_NAME);
737