net/batman-adv/routing.c

   1 /* Copyright (C) 2007-2016  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 "network-coding.h"
  44 #include "originator.h"
  45 #include "packet.h"
  46 #include "send.h"
  47 #include "soft-interface.h"
  48 #include "translation-table.h"
  49
  50 static int batadv_route_unicast_packet(struct sk_buff *skb,
  51                                        struct batadv_hard_iface *recv_if);
  52
  53 /**
  54  * _batadv_update_route - set the router for this originator
  55  * @bat_priv: the bat priv with all the soft interface information
  56  * @orig_node: orig node which is to be configured
  57  * @recv_if: the receive interface for which this route is set
  58  * @neigh_node: neighbor which should be the next router
  59  *
  60  * This function does not perform any error checks
  61  */
  62 static void _batadv_update_route(struct batadv_priv *bat_priv,
  63                                  struct batadv_orig_node *orig_node,
  64                                  struct batadv_hard_iface *recv_if,
  65                                  struct batadv_neigh_node *neigh_node)
  66 {
  67         struct batadv_orig_ifinfo *orig_ifinfo;
  68         struct batadv_neigh_node *curr_router;
  69
  70         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
  71         if (!orig_ifinfo)
  72                 return;
  73
  74         rcu_read_lock();
  75         curr_router = rcu_dereference(orig_ifinfo->router);
  76         if (curr_router && !atomic_inc_not_zero(&curr_router->refcount))
  77                 curr_router = NULL;
  78         rcu_read_unlock();
  79
  80         /* route deleted */
  81         if ((curr_router) && (!neigh_node)) {
  82                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  83                            "Deleting route towards: %pM\n", orig_node->orig);
  84                 batadv_tt_global_del_orig(bat_priv, orig_node, -1,
  85                                           "Deleted route towards originator");
  86
  87         /* route added */
  88         } else if ((!curr_router) && (neigh_node)) {
  89                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  90                            "Adding route towards: %pM (via %pM)\n",
  91                            orig_node->orig, neigh_node->addr);
  92         /* route changed */
  93         } else if (neigh_node && curr_router) {
  94                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  95                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
  96                            orig_node->orig, neigh_node->addr,
  97                            curr_router->addr);
  98         }
  99
 100         if (curr_router)
 101                 batadv_neigh_node_free_ref(curr_router);
 102
 103         /* increase refcount of new best neighbor */
 104         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
 105                 neigh_node = NULL;
 106
 107         spin_lock_bh(&orig_node->neigh_list_lock);
 108         rcu_assign_pointer(orig_ifinfo->router, neigh_node);
 109         spin_unlock_bh(&orig_node->neigh_list_lock);
 110         batadv_orig_ifinfo_free_ref(orig_ifinfo);
 111
 112         /* decrease refcount of previous best neighbor */
 113         if (curr_router)
 114                 batadv_neigh_node_free_ref(curr_router);
 115 }
 116
 117 /**
 118  * batadv_update_route - set the router for this originator
 119  * @bat_priv: the bat priv with all the soft interface information
 120  * @orig_node: orig node which is to be configured
 121  * @recv_if: the receive interface for which this route is set
 122  * @neigh_node: neighbor which should be the next router
 123  */
 124 void batadv_update_route(struct batadv_priv *bat_priv,
 125                          struct batadv_orig_node *orig_node,
 126                          struct batadv_hard_iface *recv_if,
 127                          struct batadv_neigh_node *neigh_node)
 128 {
 129         struct batadv_neigh_node *router = NULL;
 130
 131         if (!orig_node)
 132                 goto out;
 133
 134         router = batadv_orig_router_get(orig_node, recv_if);
 135
 136         if (router != neigh_node)
 137                 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
 138
 139 out:
 140         if (router)
 141                 batadv_neigh_node_free_ref(router);
 142 }
 143
 144 /**
 145  * batadv_window_protected - checks whether the host restarted and is in the
 146  *  protection time.
 147  * @bat_priv: the bat priv with all the soft interface information
 148  * @seq_num_diff: difference between the current/received sequence number and
 149  *  the last sequence number
 150  * @seq_old_max_diff: maximum age of sequence number not considered as restart
 151  * @last_reset: jiffies timestamp of the last reset, will be updated when reset
 152  *  is detected
 153  * @protection_started: is set to true if the protection window was started,
 154  *   doesn't change otherwise.
 155  *
 156  * Return:
 157  *  0 if the packet is to be accepted.
 158  *  1 if the packet is to be ignored.
 159  */
 160 int batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
 161                             s32 seq_old_max_diff, unsigned long *last_reset,
 162                             bool *protection_started)
 163 {
 164         if (seq_num_diff <= -seq_old_max_diff ||
 165             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 166                 if (!batadv_has_timed_out(*last_reset,
 167                                           BATADV_RESET_PROTECTION_MS))
 168                         return 1;
 169
 170                 *last_reset = jiffies;
 171                 if (protection_started)
 172                         *protection_started = true;
 173                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 174                            "old packet received, start protection\n");
 175         }
 176
 177         return 0;
 178 }
 179
 180 bool batadv_check_management_packet(struct sk_buff *skb,
 181                                     struct batadv_hard_iface *hard_iface,
 182                                     int header_len)
 183 {
 184         struct ethhdr *ethhdr;
 185
 186         /* drop packet if it has not necessary minimum size */
 187         if (unlikely(!pskb_may_pull(skb, header_len)))
 188                 return false;
 189
 190         ethhdr = eth_hdr(skb);
 191
 192         /* packet with broadcast indication but unicast recipient */
 193         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 194                 return false;
 195
 196         /* packet with broadcast sender address */
 197         if (is_broadcast_ether_addr(ethhdr->h_source))
 198                 return false;
 199
 200         /* create a copy of the skb, if needed, to modify it. */
 201         if (skb_cow(skb, 0) < 0)
 202                 return false;
 203
 204         /* keep skb linear */
 205         if (skb_linearize(skb) < 0)
 206                 return false;
 207
 208         return true;
 209 }
 210
 211 /**
 212  * batadv_recv_my_icmp_packet - receive an icmp packet locally
 213  * @bat_priv: the bat priv with all the soft interface information
 214  * @skb: icmp packet to process
 215  *
 216  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 217  * otherwise.
 218  */
 219 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 220                                       struct sk_buff *skb)
 221 {
 222         struct batadv_hard_iface *primary_if = NULL;
 223         struct batadv_orig_node *orig_node = NULL;
 224         struct batadv_icmp_header *icmph;
 225         int res, ret = NET_RX_DROP;
 226
 227         icmph = (struct batadv_icmp_header *)skb->data;
 228
 229         switch (icmph->msg_type) {
 230         case BATADV_ECHO_REPLY:
 231         case BATADV_DESTINATION_UNREACHABLE:
 232         case BATADV_TTL_EXCEEDED:
 233                 /* receive the packet */
 234                 if (skb_linearize(skb) < 0)
 235                         break;
 236
 237                 batadv_socket_receive_packet(icmph, skb->len);
 238                 break;
 239         case BATADV_ECHO_REQUEST:
 240                 /* answer echo request (ping) */
 241                 primary_if = batadv_primary_if_get_selected(bat_priv);
 242                 if (!primary_if)
 243                         goto out;
 244
 245                 /* get routing information */
 246                 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig);
 247                 if (!orig_node)
 248                         goto out;
 249
 250                 /* create a copy of the skb, if needed, to modify it. */
 251                 if (skb_cow(skb, ETH_HLEN) < 0)
 252                         goto out;
 253
 254                 icmph = (struct batadv_icmp_header *)skb->data;
 255
 256                 ether_addr_copy(icmph->dst, icmph->orig);
 257                 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
 258                 icmph->msg_type = BATADV_ECHO_REPLY;
 259                 icmph->ttl = BATADV_TTL;
 260
 261                 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 262                 if (res != NET_XMIT_DROP)
 263                         ret = NET_RX_SUCCESS;
 264
 265                 break;
 266         default:
 267                 /* drop unknown type */
 268                 goto out;
 269         }
 270 out:
 271         if (primary_if)
 272                 batadv_hardif_free_ref(primary_if);
 273         if (orig_node)
 274                 batadv_orig_node_free_ref(orig_node);
 275         return ret;
 276 }
 277
 278 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 279                                          struct sk_buff *skb)
 280 {
 281         struct batadv_hard_iface *primary_if = NULL;
 282         struct batadv_orig_node *orig_node = NULL;
 283         struct batadv_icmp_packet *icmp_packet;
 284         int ret = NET_RX_DROP;
 285
 286         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 287
 288         /* send TTL exceeded if packet is an echo request (traceroute) */
 289         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 290                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 291                          icmp_packet->orig, icmp_packet->dst);
 292                 goto out;
 293         }
 294
 295         primary_if = batadv_primary_if_get_selected(bat_priv);
 296         if (!primary_if)
 297                 goto out;
 298
 299         /* get routing information */
 300         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 301         if (!orig_node)
 302                 goto out;
 303
 304         /* create a copy of the skb, if needed, to modify it. */
 305         if (skb_cow(skb, ETH_HLEN) < 0)
 306                 goto out;
 307
 308         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 309
 310         ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
 311         ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
 312         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 313         icmp_packet->ttl = BATADV_TTL;
 314
 315         if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 316                 ret = NET_RX_SUCCESS;
 317
 318 out:
 319         if (primary_if)
 320                 batadv_hardif_free_ref(primary_if);
 321         if (orig_node)
 322                 batadv_orig_node_free_ref(orig_node);
 323         return ret;
 324 }
 325
 326 int batadv_recv_icmp_packet(struct sk_buff *skb,
 327                             struct batadv_hard_iface *recv_if)
 328 {
 329         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 330         struct batadv_icmp_header *icmph;
 331         struct batadv_icmp_packet_rr *icmp_packet_rr;
 332         struct ethhdr *ethhdr;
 333         struct batadv_orig_node *orig_node = NULL;
 334         int hdr_size = sizeof(struct batadv_icmp_header);
 335         int ret = NET_RX_DROP;
 336
 337         /* drop packet if it has not necessary minimum size */
 338         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 339                 goto out;
 340
 341         ethhdr = eth_hdr(skb);
 342
 343         /* packet with unicast indication but broadcast recipient */
 344         if (is_broadcast_ether_addr(ethhdr->h_dest))
 345                 goto out;
 346
 347         /* packet with broadcast sender address */
 348         if (is_broadcast_ether_addr(ethhdr->h_source))
 349                 goto out;
 350
 351         /* not for me */
 352         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 353                 goto out;
 354
 355         icmph = (struct batadv_icmp_header *)skb->data;
 356
 357         /* add record route information if not full */
 358         if ((icmph->msg_type == BATADV_ECHO_REPLY ||
 359              icmph->msg_type == BATADV_ECHO_REQUEST) &&
 360             (skb->len >= sizeof(struct batadv_icmp_packet_rr))) {
 361                 if (skb_linearize(skb) < 0)
 362                         goto out;
 363
 364                 /* create a copy of the skb, if needed, to modify it. */
 365                 if (skb_cow(skb, ETH_HLEN) < 0)
 366                         goto out;
 367
 368                 icmph = (struct batadv_icmp_header *)skb->data;
 369                 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
 370                 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
 371                         goto out;
 372
 373                 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
 374                                 ethhdr->h_dest);
 375                 icmp_packet_rr->rr_cur++;
 376         }
 377
 378         /* packet for me */
 379         if (batadv_is_my_mac(bat_priv, icmph->dst))
 380                 return batadv_recv_my_icmp_packet(bat_priv, skb);
 381
 382         /* TTL exceeded */
 383         if (icmph->ttl < 2)
 384                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 385
 386         /* get routing information */
 387         orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
 388         if (!orig_node)
 389                 goto out;
 390
 391         /* create a copy of the skb, if needed, to modify it. */
 392         if (skb_cow(skb, ETH_HLEN) < 0)
 393                 goto out;
 394
 395         icmph = (struct batadv_icmp_header *)skb->data;
 396
 397         /* decrement ttl */
 398         icmph->ttl--;
 399
 400         /* route it */
 401         if (batadv_send_skb_to_orig(skb, orig_node, recv_if) != NET_XMIT_DROP)
 402                 ret = NET_RX_SUCCESS;
 403
 404 out:
 405         if (orig_node)
 406                 batadv_orig_node_free_ref(orig_node);
 407         return ret;
 408 }
 409
 410 /**
 411  * batadv_check_unicast_packet - Check for malformed unicast packets
 412  * @bat_priv: the bat priv with all the soft interface information
 413  * @skb: packet to check
 414  * @hdr_size: size of header to pull
 415  *
 416  * Check for short header and bad addresses in given packet.
 417  *
 418  * Return: negative value when check fails and 0 otherwise. The negative value
 419  * depends on the reason: -ENODATA for bad header, -EBADR for broadcast
 420  * destination or source, and -EREMOTE for non-local (other host) destination.
 421  */
 422 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 423                                        struct sk_buff *skb, int hdr_size)
 424 {
 425         struct ethhdr *ethhdr;
 426
 427         /* drop packet if it has not necessary minimum size */
 428         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 429                 return -ENODATA;
 430
 431         ethhdr = eth_hdr(skb);
 432
 433         /* packet with unicast indication but broadcast recipient */
 434         if (is_broadcast_ether_addr(ethhdr->h_dest))
 435                 return -EBADR;
 436
 437         /* packet with broadcast sender address */
 438         if (is_broadcast_ether_addr(ethhdr->h_source))
 439                 return -EBADR;
 440
 441         /* not for me */
 442         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 443                 return -EREMOTE;
 444
 445         return 0;
 446 }
 447
 448 /**
 449  * batadv_find_router - find a suitable router for this originator
 450  * @bat_priv: the bat priv with all the soft interface information
 451  * @orig_node: the destination node
 452  * @recv_if: pointer to interface this packet was received on
 453  *
 454  * Return: the router which should be used for this orig_node on
 455  * this interface, or NULL if not available.
 456  */
 457 struct batadv_neigh_node *
 458 batadv_find_router(struct batadv_priv *bat_priv,
 459                    struct batadv_orig_node *orig_node,
 460                    struct batadv_hard_iface *recv_if)
 461 {
 462         struct batadv_algo_ops *bao = bat_priv->bat_algo_ops;
 463         struct batadv_neigh_node *first_candidate_router = NULL;
 464         struct batadv_neigh_node *next_candidate_router = NULL;
 465         struct batadv_neigh_node *router, *cand_router = NULL;
 466         struct batadv_neigh_node *last_cand_router = NULL;
 467         struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
 468         struct batadv_orig_ifinfo *next_candidate = NULL;
 469         struct batadv_orig_ifinfo *last_candidate;
 470         bool last_candidate_found = false;
 471
 472         if (!orig_node)
 473                 return NULL;
 474
 475         router = batadv_orig_router_get(orig_node, recv_if);
 476
 477         if (!router)
 478                 return router;
 479
 480         /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
 481          * and if activated.
 482          */
 483         if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding)))
 484                 return router;
 485
 486         /* bonding: loop through the list of possible routers found
 487          * for the various outgoing interfaces and find a candidate after
 488          * the last chosen bonding candidate (next_candidate). If no such
 489          * router is found, use the first candidate found (the previously
 490          * chosen bonding candidate might have been the last one in the list).
 491          * If this can't be found either, return the previously chosen
 492          * router - obviously there are no other candidates.
 493          */
 494         rcu_read_lock();
 495         last_candidate = orig_node->last_bonding_candidate;
 496         if (last_candidate)
 497                 last_cand_router = rcu_dereference(last_candidate->router);
 498
 499         hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
 500                 /* acquire some structures and references ... */
 501                 if (!kref_get_unless_zero(&cand->refcount))
 502                         continue;
 503
 504                 cand_router = rcu_dereference(cand->router);
 505                 if (!cand_router)
 506                         goto next;
 507
 508                 if (!atomic_inc_not_zero(&cand_router->refcount)) {
 509                         cand_router = NULL;
 510                         goto next;
 511                 }
 512
 513                 /* alternative candidate should be good enough to be
 514                  * considered
 515                  */
 516                 if (!bao->bat_neigh_is_similar_or_better(cand_router,
 517                                                          cand->if_outgoing,
 518                                                          router, recv_if))
 519                         goto next;
 520
 521                 /* don't use the same router twice */
 522                 if (last_cand_router == cand_router)
 523                         goto next;
 524
 525                 /* mark the first possible candidate */
 526                 if (!first_candidate) {
 527                         atomic_inc(&cand_router->refcount);
 528                         kref_get(&cand->refcount);
 529                         first_candidate = cand;
 530                         first_candidate_router = cand_router;
 531                 }
 532
 533                 /* check if the loop has already passed the previously selected
 534                  * candidate ... this function should select the next candidate
 535                  * AFTER the previously used bonding candidate.
 536                  */
 537                 if (!last_candidate || last_candidate_found) {
 538                         next_candidate = cand;
 539                         next_candidate_router = cand_router;
 540                         break;
 541                 }
 542
 543                 if (last_candidate == cand)
 544                         last_candidate_found = true;
 545 next:
 546                 /* free references */
 547                 if (cand_router) {
 548                         batadv_neigh_node_free_ref(cand_router);
 549                         cand_router = NULL;
 550                 }
 551                 batadv_orig_ifinfo_free_ref(cand);
 552         }
 553         rcu_read_unlock();
 554
 555         /* last_bonding_candidate is reset below, remove the old reference. */
 556         if (orig_node->last_bonding_candidate)
 557                 batadv_orig_ifinfo_free_ref(orig_node->last_bonding_candidate);
 558
 559         /* After finding candidates, handle the three cases:
 560          * 1) there is a next candidate, use that
 561          * 2) there is no next candidate, use the first of the list
 562          * 3) there is no candidate at all, return the default router
 563          */
 564         if (next_candidate) {
 565                 batadv_neigh_node_free_ref(router);
 566
 567                 /* remove references to first candidate, we don't need it. */
 568                 if (first_candidate) {
 569                         batadv_neigh_node_free_ref(first_candidate_router);
 570                         batadv_orig_ifinfo_free_ref(first_candidate);
 571                 }
 572                 router = next_candidate_router;
 573                 orig_node->last_bonding_candidate = next_candidate;
 574         } else if (first_candidate) {
 575                 batadv_neigh_node_free_ref(router);
 576
 577                 /* refcounting has already been done in the loop above. */
 578                 router = first_candidate_router;
 579                 orig_node->last_bonding_candidate = first_candidate;
 580         } else {
 581                 orig_node->last_bonding_candidate = NULL;
 582         }
 583
 584         return router;
 585 }
 586
 587 static int batadv_route_unicast_packet(struct sk_buff *skb,
 588                                        struct batadv_hard_iface *recv_if)
 589 {
 590         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 591         struct batadv_orig_node *orig_node = NULL;
 592         struct batadv_unicast_packet *unicast_packet;
 593         struct ethhdr *ethhdr = eth_hdr(skb);
 594         int res, hdr_len, ret = NET_RX_DROP;
 595
 596         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 597
 598         /* TTL exceeded */
 599         if (unicast_packet->ttl < 2) {
 600                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 601                          ethhdr->h_source, unicast_packet->dest);
 602                 goto out;
 603         }
 604
 605         /* get routing information */
 606         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 607
 608         if (!orig_node)
 609                 goto out;
 610
 611         /* create a copy of the skb, if needed, to modify it. */
 612         if (skb_cow(skb, ETH_HLEN) < 0)
 613                 goto out;
 614
 615         /* decrement ttl */
 616         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 617         unicast_packet->ttl--;
 618
 619         switch (unicast_packet->packet_type) {
 620         case BATADV_UNICAST_4ADDR:
 621                 hdr_len = sizeof(struct batadv_unicast_4addr_packet);
 622                 break;
 623         case BATADV_UNICAST:
 624                 hdr_len = sizeof(struct batadv_unicast_packet);
 625                 break;
 626         default:
 627                 /* other packet types not supported - yet */
 628                 hdr_len = -1;
 629                 break;
 630         }
 631
 632         if (hdr_len > 0)
 633                 batadv_skb_set_priority(skb, hdr_len);
 634
 635         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 636
 637         /* translate transmit result into receive result */
 638         if (res == NET_XMIT_SUCCESS) {
 639                 /* skb was transmitted and consumed */
 640                 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 641                 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 642                                    skb->len + ETH_HLEN);
 643
 644                 ret = NET_RX_SUCCESS;
 645         } else if (res == NET_XMIT_POLICED) {
 646                 /* skb was buffered and consumed */
 647                 ret = NET_RX_SUCCESS;
 648         }
 649
 650 out:
 651         if (orig_node)
 652                 batadv_orig_node_free_ref(orig_node);
 653         return ret;
 654 }
 655
 656 /**
 657  * batadv_reroute_unicast_packet - update the unicast header for re-routing
 658  * @bat_priv: the bat priv with all the soft interface information
 659  * @unicast_packet: the unicast header to be updated
 660  * @dst_addr: the payload destination
 661  * @vid: VLAN identifier
 662  *
 663  * Search the translation table for dst_addr and update the unicast header with
 664  * the new corresponding information (originator address where the destination
 665  * client currently is and its known TTVN)
 666  *
 667  * Return: true if the packet header has been updated, false otherwise
 668  */
 669 static bool
 670 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
 671                               struct batadv_unicast_packet *unicast_packet,
 672                               u8 *dst_addr, unsigned short vid)
 673 {
 674         struct batadv_orig_node *orig_node = NULL;
 675         struct batadv_hard_iface *primary_if = NULL;
 676         bool ret = false;
 677         u8 *orig_addr, orig_ttvn;
 678
 679         if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
 680                 primary_if = batadv_primary_if_get_selected(bat_priv);
 681                 if (!primary_if)
 682                         goto out;
 683                 orig_addr = primary_if->net_dev->dev_addr;
 684                 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 685         } else {
 686                 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
 687                                                      vid);
 688                 if (!orig_node)
 689                         goto out;
 690
 691                 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
 692                         goto out;
 693
 694                 orig_addr = orig_node->orig;
 695                 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 696         }
 697
 698         /* update the packet header */
 699         ether_addr_copy(unicast_packet->dest, orig_addr);
 700         unicast_packet->ttvn = orig_ttvn;
 701
 702         ret = true;
 703 out:
 704         if (primary_if)
 705                 batadv_hardif_free_ref(primary_if);
 706         if (orig_node)
 707                 batadv_orig_node_free_ref(orig_node);
 708
 709         return ret;
 710 }
 711
 712 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 713                                      struct sk_buff *skb, int hdr_len) {
 714         struct batadv_unicast_packet *unicast_packet;
 715         struct batadv_hard_iface *primary_if;
 716         struct batadv_orig_node *orig_node;
 717         u8 curr_ttvn, old_ttvn;
 718         struct ethhdr *ethhdr;
 719         unsigned short vid;
 720         int is_old_ttvn;
 721
 722         /* check if there is enough data before accessing it */
 723         if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
 724                 return 0;
 725
 726         /* create a copy of the skb (in case of for re-routing) to modify it. */
 727         if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
 728                 return 0;
 729
 730         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 731         vid = batadv_get_vid(skb, hdr_len);
 732         ethhdr = (struct ethhdr *)(skb->data + hdr_len);
 733
 734         /* check if the destination client was served by this node and it is now
 735          * roaming. In this case, it means that the node has got a ROAM_ADV
 736          * message and that it knows the new destination in the mesh to re-route
 737          * the packet to
 738          */
 739         if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
 740                 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
 741                                                   ethhdr->h_dest, vid))
 742                         batadv_dbg_ratelimited(BATADV_DBG_TT,
 743                                                bat_priv,
 744                                                "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
 745                                                unicast_packet->dest,
 746                                                ethhdr->h_dest);
 747                 /* at this point the mesh destination should have been
 748                  * substituted with the originator address found in the global
 749                  * table. If not, let the packet go untouched anyway because
 750                  * there is nothing the node can do
 751                  */
 752                 return 1;
 753         }
 754
 755         /* retrieve the TTVN known by this node for the packet destination. This
 756          * value is used later to check if the node which sent (or re-routed
 757          * last time) the packet had an updated information or not
 758          */
 759         curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 760         if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 761                 orig_node = batadv_orig_hash_find(bat_priv,
 762                                                   unicast_packet->dest);
 763                 /* if it is not possible to find the orig_node representing the
 764                  * destination, the packet can immediately be dropped as it will
 765                  * not be possible to deliver it
 766                  */
 767                 if (!orig_node)
 768                         return 0;
 769
 770                 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 771                 batadv_orig_node_free_ref(orig_node);
 772         }
 773
 774         /* check if the TTVN contained in the packet is fresher than what the
 775          * node knows
 776          */
 777         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 778         if (!is_old_ttvn)
 779                 return 1;
 780
 781         old_ttvn = unicast_packet->ttvn;
 782         /* the packet was forged based on outdated network information. Its
 783          * destination can possibly be updated and forwarded towards the new
 784          * target host
 785          */
 786         if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
 787                                           ethhdr->h_dest, vid)) {
 788                 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
 789                                        "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
 790                                        unicast_packet->dest, ethhdr->h_dest,
 791                                        old_ttvn, curr_ttvn);
 792                 return 1;
 793         }
 794
 795         /* the packet has not been re-routed: either the destination is
 796          * currently served by this node or there is no destination at all and
 797          * it is possible to drop the packet
 798          */
 799         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
 800                 return 0;
 801
 802         /* update the header in order to let the packet be delivered to this
 803          * node's soft interface
 804          */
 805         primary_if = batadv_primary_if_get_selected(bat_priv);
 806         if (!primary_if)
 807                 return 0;
 808
 809         ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
 810
 811         batadv_hardif_free_ref(primary_if);
 812
 813         unicast_packet->ttvn = curr_ttvn;
 814
 815         return 1;
 816 }
 817
 818 /**
 819  * batadv_recv_unhandled_unicast_packet - receive and process packets which
 820  *      are in the unicast number space but not yet known to the implementation
 821  * @skb: unicast tvlv packet to process
 822  * @recv_if: pointer to interface this packet was received on
 823  *
 824  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 825  * otherwise.
 826  */
 827 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
 828                                          struct batadv_hard_iface *recv_if)
 829 {
 830         struct batadv_unicast_packet *unicast_packet;
 831         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 832         int check, hdr_size = sizeof(*unicast_packet);
 833
 834         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 835         if (check < 0)
 836                 return NET_RX_DROP;
 837
 838         /* we don't know about this type, drop it. */
 839         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 840         if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
 841                 return NET_RX_DROP;
 842
 843         return batadv_route_unicast_packet(skb, recv_if);
 844 }
 845
 846 int batadv_recv_unicast_packet(struct sk_buff *skb,
 847                                struct batadv_hard_iface *recv_if)
 848 {
 849         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 850         struct batadv_unicast_packet *unicast_packet;
 851         struct batadv_unicast_4addr_packet *unicast_4addr_packet;
 852         u8 *orig_addr;
 853         struct batadv_orig_node *orig_node = NULL;
 854         int check, hdr_size = sizeof(*unicast_packet);
 855         enum batadv_subtype subtype;
 856         bool is4addr;
 857
 858         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 859         unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 860
 861         is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
 862         /* the caller function should have already pulled 2 bytes */
 863         if (is4addr)
 864                 hdr_size = sizeof(*unicast_4addr_packet);
 865
 866         /* function returns -EREMOTE for promiscuous packets */
 867         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 868
 869         /* Even though the packet is not for us, we might save it to use for
 870          * decoding a later received coded packet
 871          */
 872         if (check == -EREMOTE)
 873                 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
 874
 875         if (check < 0)
 876                 return NET_RX_DROP;
 877         if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
 878                 return NET_RX_DROP;
 879
 880         /* packet for me */
 881         if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 882                 if (is4addr) {
 883                         subtype = unicast_4addr_packet->subtype;
 884                         batadv_dat_inc_counter(bat_priv, subtype);
 885
 886                         /* Only payload data should be considered for speedy
 887                          * join. For example, DAT also uses unicast 4addr
 888                          * types, but those packets should not be considered
 889                          * for speedy join, since the clients do not actually
 890                          * reside at the sending originator.
 891                          */
 892                         if (subtype == BATADV_P_DATA) {
 893                                 orig_addr = unicast_4addr_packet->src;
 894                                 orig_node = batadv_orig_hash_find(bat_priv,
 895                                                                   orig_addr);
 896                         }
 897                 }
 898
 899                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
 900                                                           hdr_size))
 901                         goto rx_success;
 902                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
 903                                                         hdr_size))
 904                         goto rx_success;
 905
 906                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
 907                                     orig_node);
 908
 909 rx_success:
 910                 if (orig_node)
 911                         batadv_orig_node_free_ref(orig_node);
 912
 913                 return NET_RX_SUCCESS;
 914         }
 915
 916         return batadv_route_unicast_packet(skb, recv_if);
 917 }
 918
 919 /**
 920  * batadv_recv_unicast_tvlv - receive and process unicast tvlv packets
 921  * @skb: unicast tvlv packet to process
 922  * @recv_if: pointer to interface this packet was received on
 923  *
 924  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 925  * otherwise.
 926  */
 927 int batadv_recv_unicast_tvlv(struct sk_buff *skb,
 928                              struct batadv_hard_iface *recv_if)
 929 {
 930         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 931         struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
 932         unsigned char *tvlv_buff;
 933         u16 tvlv_buff_len;
 934         int hdr_size = sizeof(*unicast_tvlv_packet);
 935         int ret = NET_RX_DROP;
 936
 937         if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
 938                 return NET_RX_DROP;
 939
 940         /* the header is likely to be modified while forwarding */
 941         if (skb_cow(skb, hdr_size) < 0)
 942                 return NET_RX_DROP;
 943
 944         /* packet needs to be linearized to access the tvlv content */
 945         if (skb_linearize(skb) < 0)
 946                 return NET_RX_DROP;
 947
 948         unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
 949
 950         tvlv_buff = (unsigned char *)(skb->data + hdr_size);
 951         tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
 952
 953         if (tvlv_buff_len > skb->len - hdr_size)
 954                 return NET_RX_DROP;
 955
 956         ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
 957                                              unicast_tvlv_packet->src,
 958                                              unicast_tvlv_packet->dst,
 959                                              tvlv_buff, tvlv_buff_len);
 960
 961         if (ret != NET_RX_SUCCESS)
 962                 ret = batadv_route_unicast_packet(skb, recv_if);
 963         else
 964                 consume_skb(skb);
 965
 966         return ret;
 967 }
 968
 969 /**
 970  * batadv_recv_frag_packet - process received fragment
 971  * @skb: the received fragment
 972  * @recv_if: interface that the skb is received on
 973  *
 974  * This function does one of the three following things: 1) Forward fragment, if
 975  * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till
 976  * lack further fragments; 3) Merge fragments, if we have all needed parts.
 977  *
 978  * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
 979  */
 980 int batadv_recv_frag_packet(struct sk_buff *skb,
 981                             struct batadv_hard_iface *recv_if)
 982 {
 983         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 984         struct batadv_orig_node *orig_node_src = NULL;
 985         struct batadv_frag_packet *frag_packet;
 986         int ret = NET_RX_DROP;
 987
 988         if (batadv_check_unicast_packet(bat_priv, skb,
 989                                         sizeof(*frag_packet)) < 0)
 990                 goto out;
 991
 992         frag_packet = (struct batadv_frag_packet *)skb->data;
 993         orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
 994         if (!orig_node_src)
 995                 goto out;
 996
 997         /* Route the fragment if it is not for us and too big to be merged. */
 998         if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
 999             batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
1000                 ret = NET_RX_SUCCESS;
1001                 goto out;
1002         }
1003
1004         batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
1005         batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
1006
1007         /* Add fragment to buffer and merge if possible. */
1008         if (!batadv_frag_skb_buffer(&skb, orig_node_src))
1009                 goto out;
1010
1011         /* Deliver merged packet to the appropriate handler, if it was
1012          * merged
1013          */
1014         if (skb)
1015                 batadv_batman_skb_recv(skb, recv_if->net_dev,
1016                                        &recv_if->batman_adv_ptype, NULL);
1017
1018         ret = NET_RX_SUCCESS;
1019
1020 out:
1021         if (orig_node_src)
1022                 batadv_orig_node_free_ref(orig_node_src);
1023
1024         return ret;
1025 }
1026
1027 int batadv_recv_bcast_packet(struct sk_buff *skb,
1028                              struct batadv_hard_iface *recv_if)
1029 {
1030         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1031         struct batadv_orig_node *orig_node = NULL;
1032         struct batadv_bcast_packet *bcast_packet;
1033         struct ethhdr *ethhdr;
1034         int hdr_size = sizeof(*bcast_packet);
1035         int ret = NET_RX_DROP;
1036         s32 seq_diff;
1037         u32 seqno;
1038
1039         /* drop packet if it has not necessary minimum size */
1040         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1041                 goto out;
1042
1043         ethhdr = eth_hdr(skb);
1044
1045         /* packet with broadcast indication but unicast recipient */
1046         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1047                 goto out;
1048
1049         /* packet with broadcast sender address */
1050         if (is_broadcast_ether_addr(ethhdr->h_source))
1051                 goto out;
1052
1053         /* ignore broadcasts sent by myself */
1054         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1055                 goto out;
1056
1057         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1058
1059         /* ignore broadcasts originated by myself */
1060         if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
1061                 goto out;
1062
1063         if (bcast_packet->ttl < 2)
1064                 goto out;
1065
1066         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1067
1068         if (!orig_node)
1069                 goto out;
1070
1071         spin_lock_bh(&orig_node->bcast_seqno_lock);
1072
1073         seqno = ntohl(bcast_packet->seqno);
1074         /* check whether the packet is a duplicate */
1075         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1076                             seqno))
1077                 goto spin_unlock;
1078
1079         seq_diff = seqno - orig_node->last_bcast_seqno;
1080
1081         /* check whether the packet is old and the host just restarted. */
1082         if (batadv_window_protected(bat_priv, seq_diff,
1083                                     BATADV_BCAST_MAX_AGE,
1084                                     &orig_node->bcast_seqno_reset, NULL))
1085                 goto spin_unlock;
1086
1087         /* mark broadcast in flood history, update window position
1088          * if required.
1089          */
1090         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1091                 orig_node->last_bcast_seqno = seqno;
1092
1093         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1094
1095         /* check whether this has been sent by another originator before */
1096         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1097                 goto out;
1098
1099         batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
1100
1101         /* rebroadcast packet */
1102         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1103
1104         /* don't hand the broadcast up if it is from an originator
1105          * from the same backbone.
1106          */
1107         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1108                 goto out;
1109
1110         if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1111                 goto rx_success;
1112         if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1113                 goto rx_success;
1114
1115         /* broadcast for me */
1116         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
1117                             orig_node);
1118
1119 rx_success:
1120         ret = NET_RX_SUCCESS;
1121         goto out;
1122
1123 spin_unlock:
1124         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1125 out:
1126         if (orig_node)
1127                 batadv_orig_node_free_ref(orig_node);
1128         return ret;
1129 }