~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/batman-adv/routing.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
  2  *
  3  * Marek Lindner, Simon Wunderlich
  4  *
  5  * This program is free software; you can redistribute it and/or
  6  * modify it under the terms of version 2 of the GNU General Public
  7  * License as published by the Free Software Foundation.
  8  *
  9  * This program is distributed in the hope that it will be useful, but
 10  * WITHOUT ANY WARRANTY; without even the implied warranty of
 11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 12  * General Public License for more details.
 13  *
 14  * You should have received a copy of the GNU General Public License
 15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
 16  */
 17 
 18 #include "routing.h"
 19 #include "main.h"
 20 
 21 #include <linux/atomic.h>
 22 #include <linux/byteorder/generic.h>
 23 #include <linux/compiler.h>
 24 #include <linux/errno.h>
 25 #include <linux/etherdevice.h>
 26 #include <linux/if_ether.h>
 27 #include <linux/jiffies.h>
 28 #include <linux/kref.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/spinlock.h>
 35 #include <linux/stddef.h>
 36 
 37 #include "bitarray.h"
 38 #include "bridge_loop_avoidance.h"
 39 #include "distributed-arp-table.h"
 40 #include "fragmentation.h"
 41 #include "hard-interface.h"
 42 #include "icmp_socket.h"
 43 #include "log.h"
 44 #include "network-coding.h"
 45 #include "originator.h"
 46 #include "packet.h"
 47 #include "send.h"
 48 #include "soft-interface.h"
 49 #include "tp_meter.h"
 50 #include "translation-table.h"
 51 #include "tvlv.h"
 52 
 53 static int batadv_route_unicast_packet(struct sk_buff *skb,
 54                                        struct batadv_hard_iface *recv_if);
 55 
 56 /**
 57  * _batadv_update_route - set the router for this originator
 58  * @bat_priv: the bat priv with all the soft interface information
 59  * @orig_node: orig node which is to be configured
 60  * @recv_if: the receive interface for which this route is set
 61  * @neigh_node: neighbor which should be the next router
 62  *
 63  * This function does not perform any error checks
 64  */
 65 static void _batadv_update_route(struct batadv_priv *bat_priv,
 66                                  struct batadv_orig_node *orig_node,
 67                                  struct batadv_hard_iface *recv_if,
 68                                  struct batadv_neigh_node *neigh_node)
 69 {
 70         struct batadv_orig_ifinfo *orig_ifinfo;
 71         struct batadv_neigh_node *curr_router;
 72 
 73         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
 74         if (!orig_ifinfo)
 75                 return;
 76 
 77         spin_lock_bh(&orig_node->neigh_list_lock);
 78         /* curr_router used earlier may not be the current orig_ifinfo->router
 79          * anymore because it was dereferenced outside of the neigh_list_lock
 80          * protected region. After the new best neighbor has replace the current
 81          * best neighbor the reference counter needs to decrease. Consequently,
 82          * the code needs to ensure the curr_router variable contains a pointer
 83          * to the replaced best neighbor.
 84          */
 85         curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
 86 
 87         /* increase refcount of new best neighbor */
 88         if (neigh_node)
 89                 kref_get(&neigh_node->refcount);
 90 
 91         rcu_assign_pointer(orig_ifinfo->router, neigh_node);
 92         spin_unlock_bh(&orig_node->neigh_list_lock);
 93         batadv_orig_ifinfo_put(orig_ifinfo);
 94 
 95         /* route deleted */
 96         if (curr_router && !neigh_node) {
 97                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
 98                            "Deleting route towards: %pM\n", orig_node->orig);
 99                 batadv_tt_global_del_orig(bat_priv, orig_node, -1,
100                                           "Deleted route towards originator");
101 
102         /* route added */
103         } else if (!curr_router && neigh_node) {
104                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
105                            "Adding route towards: %pM (via %pM)\n",
106                            orig_node->orig, neigh_node->addr);
107         /* route changed */
108         } else if (neigh_node && curr_router) {
109                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
110                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
111                            orig_node->orig, neigh_node->addr,
112                            curr_router->addr);
113         }
114 
115         /* decrease refcount of previous best neighbor */
116         if (curr_router)
117                 batadv_neigh_node_put(curr_router);
118 }
119 
120 /**
121  * batadv_update_route - set the router for this originator
122  * @bat_priv: the bat priv with all the soft interface information
123  * @orig_node: orig node which is to be configured
124  * @recv_if: the receive interface for which this route is set
125  * @neigh_node: neighbor which should be the next router
126  */
127 void batadv_update_route(struct batadv_priv *bat_priv,
128                          struct batadv_orig_node *orig_node,
129                          struct batadv_hard_iface *recv_if,
130                          struct batadv_neigh_node *neigh_node)
131 {
132         struct batadv_neigh_node *router = NULL;
133 
134         if (!orig_node)
135                 goto out;
136 
137         router = batadv_orig_router_get(orig_node, recv_if);
138 
139         if (router != neigh_node)
140                 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
141 
142 out:
143         if (router)
144                 batadv_neigh_node_put(router);
145 }
146 
147 /**
148  * batadv_window_protected - checks whether the host restarted and is in the
149  *  protection time.
150  * @bat_priv: the bat priv with all the soft interface information
151  * @seq_num_diff: difference between the current/received sequence number and
152  *  the last sequence number
153  * @seq_old_max_diff: maximum age of sequence number not considered as restart
154  * @last_reset: jiffies timestamp of the last reset, will be updated when reset
155  *  is detected
156  * @protection_started: is set to true if the protection window was started,
157  *   doesn't change otherwise.
158  *
159  * Return:
160  *  false if the packet is to be accepted.
161  *  true if the packet is to be ignored.
162  */
163 bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
164                              s32 seq_old_max_diff, unsigned long *last_reset,
165                              bool *protection_started)
166 {
167         if (seq_num_diff <= -seq_old_max_diff ||
168             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
169                 if (!batadv_has_timed_out(*last_reset,
170                                           BATADV_RESET_PROTECTION_MS))
171                         return true;
172 
173                 *last_reset = jiffies;
174                 if (protection_started)
175                         *protection_started = true;
176                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
177                            "old packet received, start protection\n");
178         }
179 
180         return false;
181 }
182 
183 bool batadv_check_management_packet(struct sk_buff *skb,
184                                     struct batadv_hard_iface *hard_iface,
185                                     int header_len)
186 {
187         struct ethhdr *ethhdr;
188 
189         /* drop packet if it has not necessary minimum size */
190         if (unlikely(!pskb_may_pull(skb, header_len)))
191                 return false;
192 
193         ethhdr = eth_hdr(skb);
194 
195         /* packet with broadcast indication but unicast recipient */
196         if (!is_broadcast_ether_addr(ethhdr->h_dest))
197                 return false;
198 
199         /* packet with invalid sender address */
200         if (!is_valid_ether_addr(ethhdr->h_source))
201                 return false;
202 
203         /* create a copy of the skb, if needed, to modify it. */
204         if (skb_cow(skb, 0) < 0)
205                 return false;
206 
207         /* keep skb linear */
208         if (skb_linearize(skb) < 0)
209                 return false;
210 
211         return true;
212 }
213 
214 /**
215  * batadv_recv_my_icmp_packet - receive an icmp packet locally
216  * @bat_priv: the bat priv with all the soft interface information
217  * @skb: icmp packet to process
218  *
219  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
220  * otherwise.
221  */
222 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
223                                       struct sk_buff *skb)
224 {
225         struct batadv_hard_iface *primary_if = NULL;
226         struct batadv_orig_node *orig_node = NULL;
227         struct batadv_icmp_header *icmph;
228         int res, ret = NET_RX_DROP;
229 
230         icmph = (struct batadv_icmp_header *)skb->data;
231 
232         switch (icmph->msg_type) {
233         case BATADV_ECHO_REPLY:
234         case BATADV_DESTINATION_UNREACHABLE:
235         case BATADV_TTL_EXCEEDED:
236                 /* receive the packet */
237                 if (skb_linearize(skb) < 0)
238                         break;
239 
240                 batadv_socket_receive_packet(icmph, skb->len);
241                 break;
242         case BATADV_ECHO_REQUEST:
243                 /* answer echo request (ping) */
244                 primary_if = batadv_primary_if_get_selected(bat_priv);
245                 if (!primary_if)
246                         goto out;
247 
248                 /* get routing information */
249                 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig);
250                 if (!orig_node)
251                         goto out;
252 
253                 /* create a copy of the skb, if needed, to modify it. */
254                 if (skb_cow(skb, ETH_HLEN) < 0)
255                         goto out;
256 
257                 icmph = (struct batadv_icmp_header *)skb->data;
258 
259                 ether_addr_copy(icmph->dst, icmph->orig);
260                 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
261                 icmph->msg_type = BATADV_ECHO_REPLY;
262                 icmph->ttl = BATADV_TTL;
263 
264                 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
265                 if (res == NET_XMIT_SUCCESS)
266                         ret = NET_RX_SUCCESS;
267 
268                 /* skb was consumed */
269                 skb = NULL;
270                 break;
271         case BATADV_TP:
272                 if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet)))
273                         goto out;
274 
275                 batadv_tp_meter_recv(bat_priv, skb);
276                 ret = NET_RX_SUCCESS;
277                 /* skb was consumed */
278                 skb = NULL;
279                 goto out;
280         default:
281                 /* drop unknown type */
282                 goto out;
283         }
284 out:
285         if (primary_if)
286                 batadv_hardif_put(primary_if);
287         if (orig_node)
288                 batadv_orig_node_put(orig_node);
289 
290         kfree_skb(skb);
291 
292         return ret;
293 }
294 
295 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
296                                          struct sk_buff *skb)
297 {
298         struct batadv_hard_iface *primary_if = NULL;
299         struct batadv_orig_node *orig_node = NULL;
300         struct batadv_icmp_packet *icmp_packet;
301         int res, ret = NET_RX_DROP;
302 
303         icmp_packet = (struct batadv_icmp_packet *)skb->data;
304 
305         /* send TTL exceeded if packet is an echo request (traceroute) */
306         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
307                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
308                          icmp_packet->orig, icmp_packet->dst);
309                 goto out;
310         }
311 
312         primary_if = batadv_primary_if_get_selected(bat_priv);
313         if (!primary_if)
314                 goto out;
315 
316         /* get routing information */
317         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
318         if (!orig_node)
319                 goto out;
320 
321         /* create a copy of the skb, if needed, to modify it. */
322         if (skb_cow(skb, ETH_HLEN) < 0)
323                 goto out;
324 
325         icmp_packet = (struct batadv_icmp_packet *)skb->data;
326 
327         ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
328         ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
329         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
330         icmp_packet->ttl = BATADV_TTL;
331 
332         res = batadv_send_skb_to_orig(skb, orig_node, NULL);
333         if (res == NET_RX_SUCCESS)
334                 ret = NET_XMIT_SUCCESS;
335 
336         /* skb was consumed */
337         skb = NULL;
338 
339 out:
340         if (primary_if)
341                 batadv_hardif_put(primary_if);
342         if (orig_node)
343                 batadv_orig_node_put(orig_node);
344 
345         kfree_skb(skb);
346 
347         return ret;
348 }
349 
350 int batadv_recv_icmp_packet(struct sk_buff *skb,
351                             struct batadv_hard_iface *recv_if)
352 {
353         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
354         struct batadv_icmp_header *icmph;
355         struct batadv_icmp_packet_rr *icmp_packet_rr;
356         struct ethhdr *ethhdr;
357         struct batadv_orig_node *orig_node = NULL;
358         int hdr_size = sizeof(struct batadv_icmp_header);
359         int res, ret = NET_RX_DROP;
360 
361         /* drop packet if it has not necessary minimum size */
362         if (unlikely(!pskb_may_pull(skb, hdr_size)))
363                 goto free_skb;
364 
365         ethhdr = eth_hdr(skb);
366 
367         /* packet with unicast indication but non-unicast recipient */
368         if (!is_valid_ether_addr(ethhdr->h_dest))
369                 goto free_skb;
370 
371         /* packet with broadcast/multicast sender address */
372         if (is_multicast_ether_addr(ethhdr->h_source))
373                 goto free_skb;
374 
375         /* not for me */
376         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
377                 goto free_skb;
378 
379         icmph = (struct batadv_icmp_header *)skb->data;
380 
381         /* add record route information if not full */
382         if ((icmph->msg_type == BATADV_ECHO_REPLY ||
383              icmph->msg_type == BATADV_ECHO_REQUEST) &&
384             skb->len >= sizeof(struct batadv_icmp_packet_rr)) {
385                 if (skb_linearize(skb) < 0)
386                         goto free_skb;
387 
388                 /* create a copy of the skb, if needed, to modify it. */
389                 if (skb_cow(skb, ETH_HLEN) < 0)
390                         goto free_skb;
391 
392                 ethhdr = eth_hdr(skb);
393                 icmph = (struct batadv_icmp_header *)skb->data;
394                 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
395                 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
396                         goto free_skb;
397 
398                 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
399                                 ethhdr->h_dest);
400                 icmp_packet_rr->rr_cur++;
401         }
402 
403         /* packet for me */
404         if (batadv_is_my_mac(bat_priv, icmph->dst))
405                 return batadv_recv_my_icmp_packet(bat_priv, skb);
406 
407         /* TTL exceeded */
408         if (icmph->ttl < 2)
409                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
410 
411         /* get routing information */
412         orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
413         if (!orig_node)
414                 goto free_skb;
415 
416         /* create a copy of the skb, if needed, to modify it. */
417         if (skb_cow(skb, ETH_HLEN) < 0)
418                 goto put_orig_node;
419 
420         icmph = (struct batadv_icmp_header *)skb->data;
421 
422         /* decrement ttl */
423         icmph->ttl--;
424 
425         /* route it */
426         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
427         if (res == NET_XMIT_SUCCESS)
428                 ret = NET_RX_SUCCESS;
429 
430         /* skb was consumed */
431         skb = NULL;
432 
433 put_orig_node:
434         if (orig_node)
435                 batadv_orig_node_put(orig_node);
436 free_skb:
437         kfree_skb(skb);
438 
439         return ret;
440 }
441 
442 /**
443  * batadv_check_unicast_packet - Check for malformed unicast packets
444  * @bat_priv: the bat priv with all the soft interface information
445  * @skb: packet to check
446  * @hdr_size: size of header to pull
447  *
448  * Check for short header and bad addresses in given packet.
449  *
450  * Return: negative value when check fails and 0 otherwise. The negative value
451  * depends on the reason: -ENODATA for bad header, -EBADR for broadcast
452  * destination or source, and -EREMOTE for non-local (other host) destination.
453  */
454 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
455                                        struct sk_buff *skb, int hdr_size)
456 {
457         struct ethhdr *ethhdr;
458 
459         /* drop packet if it has not necessary minimum size */
460         if (unlikely(!pskb_may_pull(skb, hdr_size)))
461                 return -ENODATA;
462 
463         ethhdr = eth_hdr(skb);
464 
465         /* packet with unicast indication but non-unicast recipient */
466         if (!is_valid_ether_addr(ethhdr->h_dest))
467                 return -EBADR;
468 
469         /* packet with broadcast/multicast sender address */
470         if (is_multicast_ether_addr(ethhdr->h_source))
471                 return -EBADR;
472 
473         /* not for me */
474         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
475                 return -EREMOTE;
476 
477         return 0;
478 }
479 
480 /**
481  * batadv_last_bonding_get - Get last_bonding_candidate of orig_node
482  * @orig_node: originator node whose last bonding candidate should be retrieved
483  *
484  * Return: last bonding candidate of router or NULL if not found
485  *
486  * The object is returned with refcounter increased by 1.
487  */
488 static struct batadv_orig_ifinfo *
489 batadv_last_bonding_get(struct batadv_orig_node *orig_node)
490 {
491         struct batadv_orig_ifinfo *last_bonding_candidate;
492 
493         spin_lock_bh(&orig_node->neigh_list_lock);
494         last_bonding_candidate = orig_node->last_bonding_candidate;
495 
496         if (last_bonding_candidate)
497                 kref_get(&last_bonding_candidate->refcount);
498         spin_unlock_bh(&orig_node->neigh_list_lock);
499 
500         return last_bonding_candidate;
501 }
502 
503 /**
504  * batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
505  * @orig_node: originator node whose bonding candidates should be replaced
506  * @new_candidate: new bonding candidate or NULL
507  */
508 static void
509 batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
510                             struct batadv_orig_ifinfo *new_candidate)
511 {
512         struct batadv_orig_ifinfo *old_candidate;
513 
514         spin_lock_bh(&orig_node->neigh_list_lock);
515         old_candidate = orig_node->last_bonding_candidate;
516 
517         if (new_candidate)
518                 kref_get(&new_candidate->refcount);
519         orig_node->last_bonding_candidate = new_candidate;
520         spin_unlock_bh(&orig_node->neigh_list_lock);
521 
522         if (old_candidate)
523                 batadv_orig_ifinfo_put(old_candidate);
524 }
525 
526 /**
527  * batadv_find_router - find a suitable router for this originator
528  * @bat_priv: the bat priv with all the soft interface information
529  * @orig_node: the destination node
530  * @recv_if: pointer to interface this packet was received on
531  *
532  * Return: the router which should be used for this orig_node on
533  * this interface, or NULL if not available.
534  */
535 struct batadv_neigh_node *
536 batadv_find_router(struct batadv_priv *bat_priv,
537                    struct batadv_orig_node *orig_node,
538                    struct batadv_hard_iface *recv_if)
539 {
540         struct batadv_algo_ops *bao = bat_priv->algo_ops;
541         struct batadv_neigh_node *first_candidate_router = NULL;
542         struct batadv_neigh_node *next_candidate_router = NULL;
543         struct batadv_neigh_node *router, *cand_router = NULL;
544         struct batadv_neigh_node *last_cand_router = NULL;
545         struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
546         struct batadv_orig_ifinfo *next_candidate = NULL;
547         struct batadv_orig_ifinfo *last_candidate;
548         bool last_candidate_found = false;
549 
550         if (!orig_node)
551                 return NULL;
552 
553         router = batadv_orig_router_get(orig_node, recv_if);
554 
555         if (!router)
556                 return router;
557 
558         /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
559          * and if activated.
560          */
561         if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding)))
562                 return router;
563 
564         /* bonding: loop through the list of possible routers found
565          * for the various outgoing interfaces and find a candidate after
566          * the last chosen bonding candidate (next_candidate). If no such
567          * router is found, use the first candidate found (the previously
568          * chosen bonding candidate might have been the last one in the list).
569          * If this can't be found either, return the previously chosen
570          * router - obviously there are no other candidates.
571          */
572         rcu_read_lock();
573         last_candidate = batadv_last_bonding_get(orig_node);
574         if (last_candidate)
575                 last_cand_router = rcu_dereference(last_candidate->router);
576 
577         hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
578                 /* acquire some structures and references ... */
579                 if (!kref_get_unless_zero(&cand->refcount))
580                         continue;
581 
582                 cand_router = rcu_dereference(cand->router);
583                 if (!cand_router)
584                         goto next;
585 
586                 if (!kref_get_unless_zero(&cand_router->refcount)) {
587                         cand_router = NULL;
588                         goto next;
589                 }
590 
591                 /* alternative candidate should be good enough to be
592                  * considered
593                  */
594                 if (!bao->neigh.is_similar_or_better(cand_router,
595                                                      cand->if_outgoing, router,
596                                                      recv_if))
597                         goto next;
598 
599                 /* don't use the same router twice */
600                 if (last_cand_router == cand_router)
601                         goto next;
602 
603                 /* mark the first possible candidate */
604                 if (!first_candidate) {
605                         kref_get(&cand_router->refcount);
606                         kref_get(&cand->refcount);
607                         first_candidate = cand;
608                         first_candidate_router = cand_router;
609                 }
610 
611                 /* check if the loop has already passed the previously selected
612                  * candidate ... this function should select the next candidate
613                  * AFTER the previously used bonding candidate.
614                  */
615                 if (!last_candidate || last_candidate_found) {
616                         next_candidate = cand;
617                         next_candidate_router = cand_router;
618                         break;
619                 }
620 
621                 if (last_candidate == cand)
622                         last_candidate_found = true;
623 next:
624                 /* free references */
625                 if (cand_router) {
626                         batadv_neigh_node_put(cand_router);
627                         cand_router = NULL;
628                 }
629                 batadv_orig_ifinfo_put(cand);
630         }
631         rcu_read_unlock();
632 
633         /* After finding candidates, handle the three cases:
634          * 1) there is a next candidate, use that
635          * 2) there is no next candidate, use the first of the list
636          * 3) there is no candidate at all, return the default router
637          */
638         if (next_candidate) {
639                 batadv_neigh_node_put(router);
640 
641                 kref_get(&next_candidate_router->refcount);
642                 router = next_candidate_router;
643                 batadv_last_bonding_replace(orig_node, next_candidate);
644         } else if (first_candidate) {
645                 batadv_neigh_node_put(router);
646 
647                 kref_get(&first_candidate_router->refcount);
648                 router = first_candidate_router;
649                 batadv_last_bonding_replace(orig_node, first_candidate);
650         } else {
651                 batadv_last_bonding_replace(orig_node, NULL);
652         }
653 
654         /* cleanup of candidates */
655         if (first_candidate) {
656                 batadv_neigh_node_put(first_candidate_router);
657                 batadv_orig_ifinfo_put(first_candidate);
658         }
659 
660         if (next_candidate) {
661                 batadv_neigh_node_put(next_candidate_router);
662                 batadv_orig_ifinfo_put(next_candidate);
663         }
664 
665         if (last_candidate)
666                 batadv_orig_ifinfo_put(last_candidate);
667 
668         return router;
669 }
670 
671 static int batadv_route_unicast_packet(struct sk_buff *skb,
672                                        struct batadv_hard_iface *recv_if)
673 {
674         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
675         struct batadv_orig_node *orig_node = NULL;
676         struct batadv_unicast_packet *unicast_packet;
677         struct ethhdr *ethhdr = eth_hdr(skb);
678         int res, hdr_len, ret = NET_RX_DROP;
679         unsigned int len;
680 
681         unicast_packet = (struct batadv_unicast_packet *)skb->data;
682 
683         /* TTL exceeded */
684         if (unicast_packet->ttl < 2) {
685                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
686                          ethhdr->h_source, unicast_packet->dest);
687                 goto free_skb;
688         }
689 
690         /* get routing information */
691         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
692 
693         if (!orig_node)
694                 goto free_skb;
695 
696         /* create a copy of the skb, if needed, to modify it. */
697         if (skb_cow(skb, ETH_HLEN) < 0)
698                 goto put_orig_node;
699 
700         /* decrement ttl */
701         unicast_packet = (struct batadv_unicast_packet *)skb->data;
702         unicast_packet->ttl--;
703 
704         switch (unicast_packet->packet_type) {
705         case BATADV_UNICAST_4ADDR:
706                 hdr_len = sizeof(struct batadv_unicast_4addr_packet);
707                 break;
708         case BATADV_UNICAST:
709                 hdr_len = sizeof(struct batadv_unicast_packet);
710                 break;
711         default:
712                 /* other packet types not supported - yet */
713                 hdr_len = -1;
714                 break;
715         }
716 
717         if (hdr_len > 0)
718                 batadv_skb_set_priority(skb, hdr_len);
719 
720         len = skb->len;
721         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
722 
723         /* translate transmit result into receive result */
724         if (res == NET_XMIT_SUCCESS) {
725                 ret = NET_RX_SUCCESS;
726                 /* skb was transmitted and consumed */
727                 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
728                 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
729                                    len + ETH_HLEN);
730         }
731 
732         /* skb was consumed */
733         skb = NULL;
734 
735 put_orig_node:
736         batadv_orig_node_put(orig_node);
737 free_skb:
738         kfree_skb(skb);
739 
740         return ret;
741 }
742 
743 /**
744  * batadv_reroute_unicast_packet - update the unicast header for re-routing
745  * @bat_priv: the bat priv with all the soft interface information
746  * @unicast_packet: the unicast header to be updated
747  * @dst_addr: the payload destination
748  * @vid: VLAN identifier
749  *
750  * Search the translation table for dst_addr and update the unicast header with
751  * the new corresponding information (originator address where the destination
752  * client currently is and its known TTVN)
753  *
754  * Return: true if the packet header has been updated, false otherwise
755  */
756 static bool
757 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
758                               struct batadv_unicast_packet *unicast_packet,
759                               u8 *dst_addr, unsigned short vid)
760 {
761         struct batadv_orig_node *orig_node = NULL;
762         struct batadv_hard_iface *primary_if = NULL;
763         bool ret = false;
764         u8 *orig_addr, orig_ttvn;
765 
766         if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
767                 primary_if = batadv_primary_if_get_selected(bat_priv);
768                 if (!primary_if)
769                         goto out;
770                 orig_addr = primary_if->net_dev->dev_addr;
771                 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
772         } else {
773                 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
774                                                      vid);
775                 if (!orig_node)
776                         goto out;
777 
778                 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
779                         goto out;
780 
781                 orig_addr = orig_node->orig;
782                 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
783         }
784 
785         /* update the packet header */
786         ether_addr_copy(unicast_packet->dest, orig_addr);
787         unicast_packet->ttvn = orig_ttvn;
788 
789         ret = true;
790 out:
791         if (primary_if)
792                 batadv_hardif_put(primary_if);
793         if (orig_node)
794                 batadv_orig_node_put(orig_node);
795 
796         return ret;
797 }
798 
799 static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
800                                       struct sk_buff *skb, int hdr_len)
801 {
802         struct batadv_unicast_packet *unicast_packet;
803         struct batadv_hard_iface *primary_if;
804         struct batadv_orig_node *orig_node;
805         u8 curr_ttvn, old_ttvn;
806         struct ethhdr *ethhdr;
807         unsigned short vid;
808         int is_old_ttvn;
809 
810         /* check if there is enough data before accessing it */
811         if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
812                 return false;
813 
814         /* create a copy of the skb (in case of for re-routing) to modify it. */
815         if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
816                 return false;
817 
818         unicast_packet = (struct batadv_unicast_packet *)skb->data;
819         vid = batadv_get_vid(skb, hdr_len);
820         ethhdr = (struct ethhdr *)(skb->data + hdr_len);
821 
822         /* check if the destination client was served by this node and it is now
823          * roaming. In this case, it means that the node has got a ROAM_ADV
824          * message and that it knows the new destination in the mesh to re-route
825          * the packet to
826          */
827         if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
828                 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
829                                                   ethhdr->h_dest, vid))
830                         batadv_dbg_ratelimited(BATADV_DBG_TT,
831                                                bat_priv,
832                                                "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
833                                                unicast_packet->dest,
834                                                ethhdr->h_dest);
835                 /* at this point the mesh destination should have been
836                  * substituted with the originator address found in the global
837                  * table. If not, let the packet go untouched anyway because
838                  * there is nothing the node can do
839                  */
840                 return true;
841         }
842 
843         /* retrieve the TTVN known by this node for the packet destination. This
844          * value is used later to check if the node which sent (or re-routed
845          * last time) the packet had an updated information or not
846          */
847         curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
848         if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
849                 orig_node = batadv_orig_hash_find(bat_priv,
850                                                   unicast_packet->dest);
851                 /* if it is not possible to find the orig_node representing the
852                  * destination, the packet can immediately be dropped as it will
853                  * not be possible to deliver it
854                  */
855                 if (!orig_node)
856                         return false;
857 
858                 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
859                 batadv_orig_node_put(orig_node);
860         }
861 
862         /* check if the TTVN contained in the packet is fresher than what the
863          * node knows
864          */
865         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
866         if (!is_old_ttvn)
867                 return true;
868 
869         old_ttvn = unicast_packet->ttvn;
870         /* the packet was forged based on outdated network information. Its
871          * destination can possibly be updated and forwarded towards the new
872          * target host
873          */
874         if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
875                                           ethhdr->h_dest, vid)) {
876                 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
877                                        "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
878                                        unicast_packet->dest, ethhdr->h_dest,
879                                        old_ttvn, curr_ttvn);
880                 return true;
881         }
882 
883         /* the packet has not been re-routed: either the destination is
884          * currently served by this node or there is no destination at all and
885          * it is possible to drop the packet
886          */
887         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
888                 return false;
889 
890         /* update the header in order to let the packet be delivered to this
891          * node's soft interface
892          */
893         primary_if = batadv_primary_if_get_selected(bat_priv);
894         if (!primary_if)
895                 return false;
896 
897         ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
898 
899         batadv_hardif_put(primary_if);
900 
901         unicast_packet->ttvn = curr_ttvn;
902 
903         return true;
904 }
905 
906 /**
907  * batadv_recv_unhandled_unicast_packet - receive and process packets which
908  *      are in the unicast number space but not yet known to the implementation
909  * @skb: unicast tvlv packet to process
910  * @recv_if: pointer to interface this packet was received on
911  *
912  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
913  * otherwise.
914  */
915 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
916                                          struct batadv_hard_iface *recv_if)
917 {
918         struct batadv_unicast_packet *unicast_packet;
919         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
920         int check, hdr_size = sizeof(*unicast_packet);
921 
922         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
923         if (check < 0)
924                 goto free_skb;
925 
926         /* we don't know about this type, drop it. */
927         unicast_packet = (struct batadv_unicast_packet *)skb->data;
928         if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
929                 goto free_skb;
930 
931         return batadv_route_unicast_packet(skb, recv_if);
932 
933 free_skb:
934         kfree_skb(skb);
935         return NET_RX_DROP;
936 }
937 
938 int batadv_recv_unicast_packet(struct sk_buff *skb,
939                                struct batadv_hard_iface *recv_if)
940 {
941         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
942         struct batadv_unicast_packet *unicast_packet;
943         struct batadv_unicast_4addr_packet *unicast_4addr_packet;
944         u8 *orig_addr, *orig_addr_gw;
945         struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL;
946         int check, hdr_size = sizeof(*unicast_packet);
947         enum batadv_subtype subtype;
948         struct ethhdr *ethhdr;
949         int ret = NET_RX_DROP;
950         bool is4addr, is_gw;
951 
952         unicast_packet = (struct batadv_unicast_packet *)skb->data;
953         unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
954         ethhdr = eth_hdr(skb);
955 
956         is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
957         /* the caller function should have already pulled 2 bytes */
958         if (is4addr)
959                 hdr_size = sizeof(*unicast_4addr_packet);
960 
961         /* function returns -EREMOTE for promiscuous packets */
962         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
963 
964         /* Even though the packet is not for us, we might save it to use for
965          * decoding a later received coded packet
966          */
967         if (check == -EREMOTE)
968                 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
969 
970         if (check < 0)
971                 goto free_skb;
972         if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
973                 goto free_skb;
974 
975         /* packet for me */
976         if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
977                 /* If this is a unicast packet from another backgone gw,
978                  * drop it.
979                  */
980                 orig_addr_gw = ethhdr->h_source;
981                 orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw);
982                 if (orig_node_gw) {
983                         is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw,
984                                                           hdr_size);
985                         batadv_orig_node_put(orig_node_gw);
986                         if (is_gw) {
987                                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
988                                            "%s(): Dropped unicast pkt received from another backbone gw %pM.\n",
989                                            __func__, orig_addr_gw);
990                                 goto free_skb;
991                         }
992                 }
993 
994                 if (is4addr) {
995                         subtype = unicast_4addr_packet->subtype;
996                         batadv_dat_inc_counter(bat_priv, subtype);
997 
998                         /* Only payload data should be considered for speedy
999                          * join. For example, DAT also uses unicast 4addr
1000                          * types, but those packets should not be considered
1001                          * for speedy join, since the clients do not actually
1002                          * reside at the sending originator.
1003                          */
1004                         if (subtype == BATADV_P_DATA) {
1005                                 orig_addr = unicast_4addr_packet->src;
1006                                 orig_node = batadv_orig_hash_find(bat_priv,
1007                                                                   orig_addr);
1008                         }
1009                 }
1010 
1011                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
1012                                                           hdr_size))
1013                         goto rx_success;
1014                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
1015                                                         hdr_size))
1016                         goto rx_success;
1017 
1018                 batadv_interface_rx(recv_if->soft_iface, skb, hdr_size,
1019                                     orig_node);
1020 
1021 rx_success:
1022                 if (orig_node)
1023                         batadv_orig_node_put(orig_node);
1024 
1025                 return NET_RX_SUCCESS;
1026         }
1027 
1028         ret = batadv_route_unicast_packet(skb, recv_if);
1029         /* skb was consumed */
1030         skb = NULL;
1031 
1032 free_skb:
1033         kfree_skb(skb);
1034 
1035         return ret;
1036 }
1037 
1038 /**
1039  * batadv_recv_unicast_tvlv - receive and process unicast tvlv packets
1040  * @skb: unicast tvlv packet to process
1041  * @recv_if: pointer to interface this packet was received on
1042  *
1043  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1044  * otherwise.
1045  */
1046 int batadv_recv_unicast_tvlv(struct sk_buff *skb,
1047                              struct batadv_hard_iface *recv_if)
1048 {
1049         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1050         struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
1051         unsigned char *tvlv_buff;
1052         u16 tvlv_buff_len;
1053         int hdr_size = sizeof(*unicast_tvlv_packet);
1054         int ret = NET_RX_DROP;
1055 
1056         if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
1057                 goto free_skb;
1058 
1059         /* the header is likely to be modified while forwarding */
1060         if (skb_cow(skb, hdr_size) < 0)
1061                 goto free_skb;
1062 
1063         /* packet needs to be linearized to access the tvlv content */
1064         if (skb_linearize(skb) < 0)
1065                 goto free_skb;
1066 
1067         unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
1068 
1069         tvlv_buff = (unsigned char *)(skb->data + hdr_size);
1070         tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
1071 
1072         if (tvlv_buff_len > skb->len - hdr_size)
1073                 goto free_skb;
1074 
1075         ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
1076                                              unicast_tvlv_packet->src,
1077                                              unicast_tvlv_packet->dst,
1078                                              tvlv_buff, tvlv_buff_len);
1079 
1080         if (ret != NET_RX_SUCCESS) {
1081                 ret = batadv_route_unicast_packet(skb, recv_if);
1082                 /* skb was consumed */
1083                 skb = NULL;
1084         }
1085 
1086 free_skb:
1087         kfree_skb(skb);
1088 
1089         return ret;
1090 }
1091 
1092 /**
1093  * batadv_recv_frag_packet - process received fragment
1094  * @skb: the received fragment
1095  * @recv_if: interface that the skb is received on
1096  *
1097  * This function does one of the three following things: 1) Forward fragment, if
1098  * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till
1099  * lack further fragments; 3) Merge fragments, if we have all needed parts.
1100  *
1101  * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
1102  */
1103 int batadv_recv_frag_packet(struct sk_buff *skb,
1104                             struct batadv_hard_iface *recv_if)
1105 {
1106         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1107         struct batadv_orig_node *orig_node_src = NULL;
1108         struct batadv_frag_packet *frag_packet;
1109         int ret = NET_RX_DROP;
1110 
1111         if (batadv_check_unicast_packet(bat_priv, skb,
1112                                         sizeof(*frag_packet)) < 0)
1113                 goto free_skb;
1114 
1115         frag_packet = (struct batadv_frag_packet *)skb->data;
1116         orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
1117         if (!orig_node_src)
1118                 goto free_skb;
1119 
1120         skb->priority = frag_packet->priority + 256;
1121 
1122         /* Route the fragment if it is not for us and too big to be merged. */
1123         if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
1124             batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
1125                 /* skb was consumed */
1126                 skb = NULL;
1127                 ret = NET_RX_SUCCESS;
1128                 goto put_orig_node;
1129         }
1130 
1131         batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
1132         batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
1133 
1134         /* Add fragment to buffer and merge if possible. */
1135         if (!batadv_frag_skb_buffer(&skb, orig_node_src))
1136                 goto put_orig_node;
1137 
1138         /* Deliver merged packet to the appropriate handler, if it was
1139          * merged
1140          */
1141         if (skb) {
1142                 batadv_batman_skb_recv(skb, recv_if->net_dev,
1143                                        &recv_if->batman_adv_ptype, NULL);
1144                 /* skb was consumed */
1145                 skb = NULL;
1146         }
1147 
1148         ret = NET_RX_SUCCESS;
1149 
1150 put_orig_node:
1151         batadv_orig_node_put(orig_node_src);
1152 free_skb:
1153         kfree_skb(skb);
1154 
1155         return ret;
1156 }
1157 
1158 int batadv_recv_bcast_packet(struct sk_buff *skb,
1159                              struct batadv_hard_iface *recv_if)
1160 {
1161         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1162         struct batadv_orig_node *orig_node = NULL;
1163         struct batadv_bcast_packet *bcast_packet;
1164         struct ethhdr *ethhdr;
1165         int hdr_size = sizeof(*bcast_packet);
1166         int ret = NET_RX_DROP;
1167         s32 seq_diff;
1168         u32 seqno;
1169 
1170         /* drop packet if it has not necessary minimum size */
1171         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1172                 goto free_skb;
1173 
1174         ethhdr = eth_hdr(skb);
1175 
1176         /* packet with broadcast indication but unicast recipient */
1177         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1178                 goto free_skb;
1179 
1180         /* packet with broadcast/multicast sender address */
1181         if (is_multicast_ether_addr(ethhdr->h_source))
1182                 goto free_skb;
1183 
1184         /* ignore broadcasts sent by myself */
1185         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1186                 goto free_skb;
1187 
1188         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1189 
1190         /* ignore broadcasts originated by myself */
1191         if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
1192                 goto free_skb;
1193 
1194         if (bcast_packet->ttl < 2)
1195                 goto free_skb;
1196 
1197         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1198 
1199         if (!orig_node)
1200                 goto free_skb;
1201 
1202         spin_lock_bh(&orig_node->bcast_seqno_lock);
1203 
1204         seqno = ntohl(bcast_packet->seqno);
1205         /* check whether the packet is a duplicate */
1206         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1207                             seqno))
1208                 goto spin_unlock;
1209 
1210         seq_diff = seqno - orig_node->last_bcast_seqno;
1211 
1212         /* check whether the packet is old and the host just restarted. */
1213         if (batadv_window_protected(bat_priv, seq_diff,
1214                                     BATADV_BCAST_MAX_AGE,
1215                                     &orig_node->bcast_seqno_reset, NULL))
1216                 goto spin_unlock;
1217 
1218         /* mark broadcast in flood history, update window position
1219          * if required.
1220          */
1221         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1222                 orig_node->last_bcast_seqno = seqno;
1223 
1224         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1225 
1226         /* check whether this has been sent by another originator before */
1227         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1228                 goto free_skb;
1229 
1230         batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
1231 
1232         /* rebroadcast packet */
1233         batadv_add_bcast_packet_to_list(bat_priv, skb, 1, false);
1234 
1235         /* don't hand the broadcast up if it is from an originator
1236          * from the same backbone.
1237          */
1238         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1239                 goto free_skb;
1240 
1241         if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1242                 goto rx_success;
1243         if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1244                 goto rx_success;
1245 
1246         /* broadcast for me */
1247         batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node);
1248 
1249 rx_success:
1250         ret = NET_RX_SUCCESS;
1251         goto out;
1252 
1253 spin_unlock:
1254         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1255 free_skb:
1256         kfree_skb(skb);
1257 out:
1258         if (orig_node)
1259                 batadv_orig_node_put(orig_node);
1260         return ret;
1261 }
1262 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp