1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2020 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/crc32c.h>
13 #include <linux/device.h>
14 #include <linux/errno.h>
15 #include <linux/genetlink.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/kernel.h>
23 #include <linux/kobject.h>
24 #include <linux/kref.h>
25 #include <linux/list.h>
26 #include <linux/module.h>
27 #include <linux/netdevice.h>
28 #include <linux/printk.h>
29 #include <linux/rculist.h>
30 #include <linux/rcupdate.h>
31 #include <linux/seq_file.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/stddef.h>
36 #include <linux/string.h>
37 #include <linux/workqueue.h>
38 #include <net/dsfield.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 "debugfs.h"
48 #include "distributed-arp-table.h"
49 #include "gateway_client.h"
50 #include "gateway_common.h"
51 #include "hard-interface.h"
52 #include "icmp_socket.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 batadv_socket_init();
117 batadv_debugfs_init();
118
119 register_netdevice_notifier(&batadv_hard_if_notifier);
120 rtnl_link_register(&batadv_link_ops);
121 batadv_netlink_register();
122
123 pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
124 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
125
126 return 0;
127
128 err_create_wq:
129 batadv_tt_cache_destroy();
130
131 return -ENOMEM;
132 }
133
batadv_exit(void)134 static void __exit batadv_exit(void)
135 {
136 batadv_debugfs_destroy();
137 batadv_netlink_unregister();
138 rtnl_link_unregister(&batadv_link_ops);
139 unregister_netdevice_notifier(&batadv_hard_if_notifier);
140
141 flush_workqueue(batadv_event_workqueue);
142 destroy_workqueue(batadv_event_workqueue);
143 batadv_event_workqueue = NULL;
144
145 rcu_barrier();
146
147 batadv_tt_cache_destroy();
148 }
149
150 /**
151 * batadv_mesh_init() - Initialize soft interface
152 * @soft_iface: netdev struct of the soft interface
153 *
154 * Return: 0 on success or negative error number in case of failure
155 */
batadv_mesh_init(struct net_device * soft_iface)156 int batadv_mesh_init(struct net_device *soft_iface)
157 {
158 struct batadv_priv *bat_priv = netdev_priv(soft_iface);
159 int ret;
160
161 spin_lock_init(&bat_priv->forw_bat_list_lock);
162 spin_lock_init(&bat_priv->forw_bcast_list_lock);
163 spin_lock_init(&bat_priv->tt.changes_list_lock);
164 spin_lock_init(&bat_priv->tt.req_list_lock);
165 spin_lock_init(&bat_priv->tt.roam_list_lock);
166 spin_lock_init(&bat_priv->tt.last_changeset_lock);
167 spin_lock_init(&bat_priv->tt.commit_lock);
168 spin_lock_init(&bat_priv->gw.list_lock);
169 #ifdef CONFIG_BATMAN_ADV_MCAST
170 spin_lock_init(&bat_priv->mcast.mla_lock);
171 spin_lock_init(&bat_priv->mcast.want_lists_lock);
172 #endif
173 spin_lock_init(&bat_priv->tvlv.container_list_lock);
174 spin_lock_init(&bat_priv->tvlv.handler_list_lock);
175 spin_lock_init(&bat_priv->softif_vlan_list_lock);
176 spin_lock_init(&bat_priv->tp_list_lock);
177
178 INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
179 INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
180 INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
181 #ifdef CONFIG_BATMAN_ADV_MCAST
182 INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
183 INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
184 INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
185 #endif
186 INIT_LIST_HEAD(&bat_priv->tt.changes_list);
187 INIT_HLIST_HEAD(&bat_priv->tt.req_list);
188 INIT_LIST_HEAD(&bat_priv->tt.roam_list);
189 #ifdef CONFIG_BATMAN_ADV_MCAST
190 INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
191 #endif
192 INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
193 INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
194 INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
195 INIT_HLIST_HEAD(&bat_priv->tp_list);
196
197 bat_priv->gw.generation = 0;
198
199 ret = batadv_originator_init(bat_priv);
200 if (ret < 0) {
201 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
202 goto err_orig;
203 }
204
205 ret = batadv_tt_init(bat_priv);
206 if (ret < 0) {
207 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
208 goto err_tt;
209 }
210
211 ret = batadv_v_mesh_init(bat_priv);
212 if (ret < 0) {
213 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
214 goto err_v;
215 }
216
217 ret = batadv_bla_init(bat_priv);
218 if (ret < 0) {
219 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
220 goto err_bla;
221 }
222
223 ret = batadv_dat_init(bat_priv);
224 if (ret < 0) {
225 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
226 goto err_dat;
227 }
228
229 ret = batadv_nc_mesh_init(bat_priv);
230 if (ret < 0) {
231 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
232 goto err_nc;
233 }
234
235 batadv_gw_init(bat_priv);
236 batadv_mcast_init(bat_priv);
237
238 atomic_set(&bat_priv->gw.reselect, 0);
239 atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
240
241 return 0;
242
243 err_nc:
244 batadv_dat_free(bat_priv);
245 err_dat:
246 batadv_bla_free(bat_priv);
247 err_bla:
248 batadv_v_mesh_free(bat_priv);
249 err_v:
250 batadv_tt_free(bat_priv);
251 err_tt:
252 batadv_originator_free(bat_priv);
253 err_orig:
254 batadv_purge_outstanding_packets(bat_priv, NULL);
255 atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
256
257 return ret;
258 }
259
260 /**
261 * batadv_mesh_free() - Deinitialize soft interface
262 * @soft_iface: netdev struct of the soft interface
263 */
batadv_mesh_free(struct net_device * soft_iface)264 void batadv_mesh_free(struct net_device *soft_iface)
265 {
266 struct batadv_priv *bat_priv = netdev_priv(soft_iface);
267
268 atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
269
270 batadv_purge_outstanding_packets(bat_priv, NULL);
271
272 batadv_gw_node_free(bat_priv);
273
274 batadv_v_mesh_free(bat_priv);
275 batadv_nc_mesh_free(bat_priv);
276 batadv_dat_free(bat_priv);
277 batadv_bla_free(bat_priv);
278
279 batadv_mcast_free(bat_priv);
280
281 /* Free the TT and the originator tables only after having terminated
282 * all the other depending components which may use these structures for
283 * their purposes.
284 */
285 batadv_tt_free(bat_priv);
286
287 /* Since the originator table clean up routine is accessing the TT
288 * tables as well, it has to be invoked after the TT tables have been
289 * freed and marked as empty. This ensures that no cleanup RCU callbacks
290 * accessing the TT data are scheduled for later execution.
291 */
292 batadv_originator_free(bat_priv);
293
294 batadv_gw_free(bat_priv);
295
296 free_percpu(bat_priv->bat_counters);
297 bat_priv->bat_counters = NULL;
298
299 atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
300 }
301
302 /**
303 * batadv_is_my_mac() - check if the given mac address belongs to any of the
304 * real interfaces in the current mesh
305 * @bat_priv: the bat priv with all the soft interface information
306 * @addr: the address to check
307 *
308 * Return: 'true' if the mac address was found, false otherwise.
309 */
batadv_is_my_mac(struct batadv_priv * bat_priv,const u8 * addr)310 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
311 {
312 const struct batadv_hard_iface *hard_iface;
313 bool is_my_mac = false;
314
315 rcu_read_lock();
316 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
317 if (hard_iface->if_status != BATADV_IF_ACTIVE)
318 continue;
319
320 if (hard_iface->soft_iface != bat_priv->soft_iface)
321 continue;
322
323 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
324 is_my_mac = true;
325 break;
326 }
327 }
328 rcu_read_unlock();
329 return is_my_mac;
330 }
331
332 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
333 /**
334 * batadv_seq_print_text_primary_if_get() - called from debugfs table printing
335 * function that requires the primary interface
336 * @seq: debugfs table seq_file struct
337 *
338 * Return: primary interface if found or NULL otherwise.
339 */
340 struct batadv_hard_iface *
batadv_seq_print_text_primary_if_get(struct seq_file * seq)341 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
342 {
343 struct net_device *net_dev = (struct net_device *)seq->private;
344 struct batadv_priv *bat_priv = netdev_priv(net_dev);
345 struct batadv_hard_iface *primary_if;
346
347 primary_if = batadv_primary_if_get_selected(bat_priv);
348
349 if (!primary_if) {
350 seq_printf(seq,
351 "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
352 net_dev->name);
353 goto out;
354 }
355
356 if (primary_if->if_status == BATADV_IF_ACTIVE)
357 goto out;
358
359 seq_printf(seq,
360 "BATMAN mesh %s disabled - primary interface not active\n",
361 net_dev->name);
362 batadv_hardif_put(primary_if);
363 primary_if = NULL;
364
365 out:
366 return primary_if;
367 }
368 #endif
369
370 /**
371 * batadv_max_header_len() - calculate maximum encapsulation overhead for a
372 * payload packet
373 *
374 * Return: the maximum encapsulation overhead in bytes.
375 */
batadv_max_header_len(void)376 int batadv_max_header_len(void)
377 {
378 int header_len = 0;
379
380 header_len = max_t(int, header_len,
381 sizeof(struct batadv_unicast_packet));
382 header_len = max_t(int, header_len,
383 sizeof(struct batadv_unicast_4addr_packet));
384 header_len = max_t(int, header_len,
385 sizeof(struct batadv_bcast_packet));
386
387 #ifdef CONFIG_BATMAN_ADV_NC
388 header_len = max_t(int, header_len,
389 sizeof(struct batadv_coded_packet));
390 #endif
391
392 return header_len + ETH_HLEN;
393 }
394
395 /**
396 * batadv_skb_set_priority() - sets skb priority according to packet content
397 * @skb: the packet to be sent
398 * @offset: offset to the packet content
399 *
400 * This function sets a value between 256 and 263 (802.1d priority), which
401 * can be interpreted by the cfg80211 or other drivers.
402 */
batadv_skb_set_priority(struct sk_buff * skb,int offset)403 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
404 {
405 struct iphdr ip_hdr_tmp, *ip_hdr;
406 struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
407 struct ethhdr ethhdr_tmp, *ethhdr;
408 struct vlan_ethhdr *vhdr, vhdr_tmp;
409 u32 prio;
410
411 /* already set, do nothing */
412 if (skb->priority >= 256 && skb->priority <= 263)
413 return;
414
415 ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), ðhdr_tmp);
416 if (!ethhdr)
417 return;
418
419 switch (ethhdr->h_proto) {
420 case htons(ETH_P_8021Q):
421 vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
422 sizeof(*vhdr), &vhdr_tmp);
423 if (!vhdr)
424 return;
425 prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
426 prio = prio >> VLAN_PRIO_SHIFT;
427 break;
428 case htons(ETH_P_IP):
429 ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
430 sizeof(*ip_hdr), &ip_hdr_tmp);
431 if (!ip_hdr)
432 return;
433 prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
434 break;
435 case htons(ETH_P_IPV6):
436 ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
437 sizeof(*ip6_hdr), &ip6_hdr_tmp);
438 if (!ip6_hdr)
439 return;
440 prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
441 break;
442 default:
443 return;
444 }
445
446 skb->priority = prio + 256;
447 }
448
batadv_recv_unhandled_packet(struct sk_buff * skb,struct batadv_hard_iface * recv_if)449 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
450 struct batadv_hard_iface *recv_if)
451 {
452 kfree_skb(skb);
453
454 return NET_RX_DROP;
455 }
456
457 /* incoming packets with the batman ethertype received on any active hard
458 * interface
459 */
460
461 /**
462 * batadv_batman_skb_recv() - Handle incoming message from an hard interface
463 * @skb: the received packet
464 * @dev: the net device that the packet was received on
465 * @ptype: packet type of incoming packet (ETH_P_BATMAN)
466 * @orig_dev: the original receive net device (e.g. bonded device)
467 *
468 * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
469 */
batadv_batman_skb_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * ptype,struct net_device * orig_dev)470 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
471 struct packet_type *ptype,
472 struct net_device *orig_dev)
473 {
474 struct batadv_priv *bat_priv;
475 struct batadv_ogm_packet *batadv_ogm_packet;
476 struct batadv_hard_iface *hard_iface;
477 u8 idx;
478
479 hard_iface = container_of(ptype, struct batadv_hard_iface,
480 batman_adv_ptype);
481
482 /* Prevent processing a packet received on an interface which is getting
483 * shut down otherwise the packet may trigger de-reference errors
484 * further down in the receive path.
485 */
486 if (!kref_get_unless_zero(&hard_iface->refcount))
487 goto err_out;
488
489 skb = skb_share_check(skb, GFP_ATOMIC);
490
491 /* skb was released by skb_share_check() */
492 if (!skb)
493 goto err_put;
494
495 /* packet should hold at least type and version */
496 if (unlikely(!pskb_may_pull(skb, 2)))
497 goto err_free;
498
499 /* expect a valid ethernet header here. */
500 if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
501 goto err_free;
502
503 if (!hard_iface->soft_iface)
504 goto err_free;
505
506 bat_priv = netdev_priv(hard_iface->soft_iface);
507
508 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
509 goto err_free;
510
511 /* discard frames on not active interfaces */
512 if (hard_iface->if_status != BATADV_IF_ACTIVE)
513 goto err_free;
514
515 batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
516
517 if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
518 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
519 "Drop packet: incompatible batman version (%i)\n",
520 batadv_ogm_packet->version);
521 goto err_free;
522 }
523
524 /* reset control block to avoid left overs from previous users */
525 memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
526
527 idx = batadv_ogm_packet->packet_type;
528 (*batadv_rx_handler[idx])(skb, hard_iface);
529
530 batadv_hardif_put(hard_iface);
531
532 /* return NET_RX_SUCCESS in any case as we
533 * most probably dropped the packet for
534 * routing-logical reasons.
535 */
536 return NET_RX_SUCCESS;
537
538 err_free:
539 kfree_skb(skb);
540 err_put:
541 batadv_hardif_put(hard_iface);
542 err_out:
543 return NET_RX_DROP;
544 }
545
batadv_recv_handler_init(void)546 static void batadv_recv_handler_init(void)
547 {
548 int i;
549
550 for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
551 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
552
553 for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
554 batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
555
556 /* compile time checks for sizes */
557 BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
558 BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
559 BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
560 BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
561 BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
562 BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
563 BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
564 BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
565 BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
566 BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
567 BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
568 BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
569 BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
570 BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
571 BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
572 BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
573
574 i = sizeof_field(struct sk_buff, cb);
575 BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
576
577 /* broadcast packet */
578 batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
579
580 /* unicast packets ... */
581 /* unicast with 4 addresses packet */
582 batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
583 /* unicast packet */
584 batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
585 /* unicast tvlv packet */
586 batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
587 /* batman icmp packet */
588 batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
589 /* Fragmented packets */
590 batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
591 }
592
593 /**
594 * batadv_recv_handler_register() - Register handler for batman-adv packet type
595 * @packet_type: batadv_packettype which should be handled
596 * @recv_handler: receive handler for the packet type
597 *
598 * Return: 0 on success or negative error number in case of failure
599 */
600 int
batadv_recv_handler_register(u8 packet_type,int (* recv_handler)(struct sk_buff *,struct batadv_hard_iface *))601 batadv_recv_handler_register(u8 packet_type,
602 int (*recv_handler)(struct sk_buff *,
603 struct batadv_hard_iface *))
604 {
605 int (*curr)(struct sk_buff *skb,
606 struct batadv_hard_iface *recv_if);
607 curr = batadv_rx_handler[packet_type];
608
609 if (curr != batadv_recv_unhandled_packet &&
610 curr != batadv_recv_unhandled_unicast_packet)
611 return -EBUSY;
612
613 batadv_rx_handler[packet_type] = recv_handler;
614 return 0;
615 }
616
617 /**
618 * batadv_recv_handler_unregister() - Unregister handler for packet type
619 * @packet_type: batadv_packettype which should no longer be handled
620 */
batadv_recv_handler_unregister(u8 packet_type)621 void batadv_recv_handler_unregister(u8 packet_type)
622 {
623 batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
624 }
625
626 /**
627 * batadv_skb_crc32() - calculate CRC32 of the whole packet and skip bytes in
628 * the header
629 * @skb: skb pointing to fragmented socket buffers
630 * @payload_ptr: Pointer to position inside the head buffer of the skb
631 * marking the start of the data to be CRC'ed
632 *
633 * payload_ptr must always point to an address in the skb head buffer and not to
634 * a fragment.
635 *
636 * Return: big endian crc32c of the checksummed data
637 */
batadv_skb_crc32(struct sk_buff * skb,u8 * payload_ptr)638 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
639 {
640 u32 crc = 0;
641 unsigned int from;
642 unsigned int to = skb->len;
643 struct skb_seq_state st;
644 const u8 *data;
645 unsigned int len;
646 unsigned int consumed = 0;
647
648 from = (unsigned int)(payload_ptr - skb->data);
649
650 skb_prepare_seq_read(skb, from, to, &st);
651 while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
652 crc = crc32c(crc, data, len);
653 consumed += len;
654 }
655
656 return htonl(crc);
657 }
658
659 /**
660 * batadv_get_vid() - extract the VLAN identifier from skb if any
661 * @skb: the buffer containing the packet
662 * @header_len: length of the batman header preceding the ethernet header
663 *
664 * Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
665 * skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
666 */
batadv_get_vid(struct sk_buff * skb,size_t header_len)667 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
668 {
669 struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
670 struct vlan_ethhdr *vhdr;
671 unsigned short vid;
672
673 if (ethhdr->h_proto != htons(ETH_P_8021Q))
674 return BATADV_NO_FLAGS;
675
676 if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
677 return BATADV_NO_FLAGS;
678
679 vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
680 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
681 vid |= BATADV_VLAN_HAS_TAG;
682
683 return vid;
684 }
685
686 /**
687 * batadv_vlan_ap_isola_get() - return AP isolation status for the given vlan
688 * @bat_priv: the bat priv with all the soft interface information
689 * @vid: the VLAN identifier for which the AP isolation attributed as to be
690 * looked up
691 *
692 * Return: true if AP isolation is on for the VLAN identified by vid, false
693 * otherwise
694 */
batadv_vlan_ap_isola_get(struct batadv_priv * bat_priv,unsigned short vid)695 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
696 {
697 bool ap_isolation_enabled = false;
698 struct batadv_softif_vlan *vlan;
699
700 /* if the AP isolation is requested on a VLAN, then check for its
701 * setting in the proper VLAN private data structure
702 */
703 vlan = batadv_softif_vlan_get(bat_priv, vid);
704 if (vlan) {
705 ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
706 batadv_softif_vlan_put(vlan);
707 }
708
709 return ap_isolation_enabled;
710 }
711
712 /**
713 * batadv_throw_uevent() - Send an uevent with batman-adv specific env data
714 * @bat_priv: the bat priv with all the soft interface information
715 * @type: subsystem type of event. Stored in uevent's BATTYPE
716 * @action: action type of event. Stored in uevent's BATACTION
717 * @data: string with additional information to the event (ignored for
718 * BATADV_UEV_DEL). Stored in uevent's BATDATA
719 *
720 * Return: 0 on success or negative error number in case of failure
721 */
batadv_throw_uevent(struct batadv_priv * bat_priv,enum batadv_uev_type type,enum batadv_uev_action action,const char * data)722 int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
723 enum batadv_uev_action action, const char *data)
724 {
725 int ret = -ENOMEM;
726 struct kobject *bat_kobj;
727 char *uevent_env[4] = { NULL, NULL, NULL, NULL };
728
729 bat_kobj = &bat_priv->soft_iface->dev.kobj;
730
731 uevent_env[0] = kasprintf(GFP_ATOMIC,
732 "%s%s", BATADV_UEV_TYPE_VAR,
733 batadv_uev_type_str[type]);
734 if (!uevent_env[0])
735 goto out;
736
737 uevent_env[1] = kasprintf(GFP_ATOMIC,
738 "%s%s", BATADV_UEV_ACTION_VAR,
739 batadv_uev_action_str[action]);
740 if (!uevent_env[1])
741 goto out;
742
743 /* If the event is DEL, ignore the data field */
744 if (action != BATADV_UEV_DEL) {
745 uevent_env[2] = kasprintf(GFP_ATOMIC,
746 "%s%s", BATADV_UEV_DATA_VAR, data);
747 if (!uevent_env[2])
748 goto out;
749 }
750
751 ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
752 out:
753 kfree(uevent_env[0]);
754 kfree(uevent_env[1]);
755 kfree(uevent_env[2]);
756
757 if (ret)
758 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
759 "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
760 batadv_uev_type_str[type],
761 batadv_uev_action_str[action],
762 (action == BATADV_UEV_DEL ? "NULL" : data), ret);
763 return ret;
764 }
765
766 module_init(batadv_init);
767 module_exit(batadv_exit);
768
769 MODULE_LICENSE("GPL");
770
771 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
772 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
773 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
774 MODULE_VERSION(BATADV_SOURCE_VERSION);
775 MODULE_ALIAS_RTNL_LINK("batadv");
776 MODULE_ALIAS_GENL_FAMILY(BATADV_NL_NAME);
777