1 /* Copyright (C) 2007-2013 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, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 17 * 02110-1301, USA 18 */ 19 20 #include "main.h" 21 #include "routing.h" 22 #include "send.h" 23 #include "soft-interface.h" 24 #include "hard-interface.h" 25 #include "icmp_socket.h" 26 #include "translation-table.h" 27 #include "originator.h" 28 #include "vis.h" 29 #include "unicast.h" 30 #include "bridge_loop_avoidance.h" 31 #include "distributed-arp-table.h" 32 #include "network-coding.h" 33 34 static int batadv_route_unicast_packet(struct sk_buff *skb, 35 struct batadv_hard_iface *recv_if); 36 37 static void _batadv_update_route(struct batadv_priv *bat_priv, 38 struct batadv_orig_node *orig_node, 39 struct batadv_neigh_node *neigh_node) 40 { 41 struct batadv_neigh_node *curr_router; 42 43 curr_router = batadv_orig_node_get_router(orig_node); 44 45 /* route deleted */ 46 if ((curr_router) && (!neigh_node)) { 47 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 48 "Deleting route towards: %pM\n", orig_node->orig); 49 batadv_tt_global_del_orig(bat_priv, orig_node, 50 "Deleted route towards originator"); 51 52 /* route added */ 53 } else if ((!curr_router) && (neigh_node)) { 54 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 55 "Adding route towards: %pM (via %pM)\n", 56 orig_node->orig, neigh_node->addr); 57 /* route changed */ 58 } else if (neigh_node && curr_router) { 59 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 60 "Changing route towards: %pM (now via %pM - was via %pM)\n", 61 orig_node->orig, neigh_node->addr, 62 curr_router->addr); 63 } 64 65 if (curr_router) 66 batadv_neigh_node_free_ref(curr_router); 67 68 /* increase refcount of new best neighbor */ 69 if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount)) 70 neigh_node = NULL; 71 72 spin_lock_bh(&orig_node->neigh_list_lock); 73 rcu_assign_pointer(orig_node->router, neigh_node); 74 spin_unlock_bh(&orig_node->neigh_list_lock); 75 76 /* decrease refcount of previous best neighbor */ 77 if (curr_router) 78 batadv_neigh_node_free_ref(curr_router); 79 } 80 81 void batadv_update_route(struct batadv_priv *bat_priv, 82 struct batadv_orig_node *orig_node, 83 struct batadv_neigh_node *neigh_node) 84 { 85 struct batadv_neigh_node *router = NULL; 86 87 if (!orig_node) 88 goto out; 89 90 router = batadv_orig_node_get_router(orig_node); 91 92 if (router != neigh_node) 93 _batadv_update_route(bat_priv, orig_node, neigh_node); 94 95 out: 96 if (router) 97 batadv_neigh_node_free_ref(router); 98 } 99 100 /* caller must hold the neigh_list_lock */ 101 void batadv_bonding_candidate_del(struct batadv_orig_node *orig_node, 102 struct batadv_neigh_node *neigh_node) 103 { 104 /* this neighbor is not part of our candidate list */ 105 if (list_empty(&neigh_node->bonding_list)) 106 goto out; 107 108 list_del_rcu(&neigh_node->bonding_list); 109 INIT_LIST_HEAD(&neigh_node->bonding_list); 110 batadv_neigh_node_free_ref(neigh_node); 111 atomic_dec(&orig_node->bond_candidates); 112 113 out: 114 return; 115 } 116 117 void batadv_bonding_candidate_add(struct batadv_orig_node *orig_node, 118 struct batadv_neigh_node *neigh_node) 119 { 120 struct batadv_neigh_node *tmp_neigh_node, *router = NULL; 121 uint8_t interference_candidate = 0; 122 123 spin_lock_bh(&orig_node->neigh_list_lock); 124 125 /* only consider if it has the same primary address ... */ 126 if (!batadv_compare_eth(orig_node->orig, 127 neigh_node->orig_node->primary_addr)) 128 goto candidate_del; 129 130 router = batadv_orig_node_get_router(orig_node); 131 if (!router) 132 goto candidate_del; 133 134 /* ... and is good enough to be considered */ 135 if (neigh_node->tq_avg < router->tq_avg - BATADV_BONDING_TQ_THRESHOLD) 136 goto candidate_del; 137 138 /* check if we have another candidate with the same mac address or 139 * interface. If we do, we won't select this candidate because of 140 * possible interference. 141 */ 142 hlist_for_each_entry_rcu(tmp_neigh_node, 143 &orig_node->neigh_list, list) { 144 if (tmp_neigh_node == neigh_node) 145 continue; 146 147 /* we only care if the other candidate is even 148 * considered as candidate. 149 */ 150 if (list_empty(&tmp_neigh_node->bonding_list)) 151 continue; 152 153 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) || 154 (batadv_compare_eth(neigh_node->addr, 155 tmp_neigh_node->addr))) { 156 interference_candidate = 1; 157 break; 158 } 159 } 160 161 /* don't care further if it is an interference candidate */ 162 if (interference_candidate) 163 goto candidate_del; 164 165 /* this neighbor already is part of our candidate list */ 166 if (!list_empty(&neigh_node->bonding_list)) 167 goto out; 168 169 if (!atomic_inc_not_zero(&neigh_node->refcount)) 170 goto out; 171 172 list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list); 173 atomic_inc(&orig_node->bond_candidates); 174 goto out; 175 176 candidate_del: 177 batadv_bonding_candidate_del(orig_node, neigh_node); 178 179 out: 180 spin_unlock_bh(&orig_node->neigh_list_lock); 181 182 if (router) 183 batadv_neigh_node_free_ref(router); 184 } 185 186 /* copy primary address for bonding */ 187 void 188 batadv_bonding_save_primary(const struct batadv_orig_node *orig_node, 189 struct batadv_orig_node *orig_neigh_node, 190 const struct batadv_ogm_packet *batman_ogm_packet) 191 { 192 if (!(batman_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP)) 193 return; 194 195 memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN); 196 } 197 198 /* checks whether the host restarted and is in the protection time. 199 * returns: 200 * 0 if the packet is to be accepted 201 * 1 if the packet is to be ignored. 202 */ 203 int batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff, 204 unsigned long *last_reset) 205 { 206 if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE || 207 seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) { 208 if (!batadv_has_timed_out(*last_reset, 209 BATADV_RESET_PROTECTION_MS)) 210 return 1; 211 212 *last_reset = jiffies; 213 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 214 "old packet received, start protection\n"); 215 } 216 217 return 0; 218 } 219 220 bool batadv_check_management_packet(struct sk_buff *skb, 221 struct batadv_hard_iface *hard_iface, 222 int header_len) 223 { 224 struct ethhdr *ethhdr; 225 226 /* drop packet if it has not necessary minimum size */ 227 if (unlikely(!pskb_may_pull(skb, header_len))) 228 return false; 229 230 ethhdr = eth_hdr(skb); 231 232 /* packet with broadcast indication but unicast recipient */ 233 if (!is_broadcast_ether_addr(ethhdr->h_dest)) 234 return false; 235 236 /* packet with broadcast sender address */ 237 if (is_broadcast_ether_addr(ethhdr->h_source)) 238 return false; 239 240 /* create a copy of the skb, if needed, to modify it. */ 241 if (skb_cow(skb, 0) < 0) 242 return false; 243 244 /* keep skb linear */ 245 if (skb_linearize(skb) < 0) 246 return false; 247 248 return true; 249 } 250 251 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, 252 struct sk_buff *skb, size_t icmp_len) 253 { 254 struct batadv_hard_iface *primary_if = NULL; 255 struct batadv_orig_node *orig_node = NULL; 256 struct batadv_icmp_packet_rr *icmp_packet; 257 int ret = NET_RX_DROP; 258 259 icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; 260 261 /* add data to device queue */ 262 if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { 263 batadv_socket_receive_packet(icmp_packet, icmp_len); 264 goto out; 265 } 266 267 primary_if = batadv_primary_if_get_selected(bat_priv); 268 if (!primary_if) 269 goto out; 270 271 /* answer echo request (ping) */ 272 /* get routing information */ 273 orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); 274 if (!orig_node) 275 goto out; 276 277 /* create a copy of the skb, if needed, to modify it. */ 278 if (skb_cow(skb, ETH_HLEN) < 0) 279 goto out; 280 281 icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; 282 283 memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); 284 memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN); 285 icmp_packet->msg_type = BATADV_ECHO_REPLY; 286 icmp_packet->header.ttl = BATADV_TTL; 287 288 if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP) 289 ret = NET_RX_SUCCESS; 290 291 out: 292 if (primary_if) 293 batadv_hardif_free_ref(primary_if); 294 if (orig_node) 295 batadv_orig_node_free_ref(orig_node); 296 return ret; 297 } 298 299 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, 300 struct sk_buff *skb) 301 { 302 struct batadv_hard_iface *primary_if = NULL; 303 struct batadv_orig_node *orig_node = NULL; 304 struct batadv_icmp_packet *icmp_packet; 305 int ret = NET_RX_DROP; 306 307 icmp_packet = (struct batadv_icmp_packet *)skb->data; 308 309 /* send TTL exceeded if packet is an echo request (traceroute) */ 310 if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { 311 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n", 312 icmp_packet->orig, icmp_packet->dst); 313 goto out; 314 } 315 316 primary_if = batadv_primary_if_get_selected(bat_priv); 317 if (!primary_if) 318 goto out; 319 320 /* get routing information */ 321 orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); 322 if (!orig_node) 323 goto out; 324 325 /* create a copy of the skb, if needed, to modify it. */ 326 if (skb_cow(skb, ETH_HLEN) < 0) 327 goto out; 328 329 icmp_packet = (struct batadv_icmp_packet *)skb->data; 330 331 memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); 332 memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN); 333 icmp_packet->msg_type = BATADV_TTL_EXCEEDED; 334 icmp_packet->header.ttl = BATADV_TTL; 335 336 if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP) 337 ret = NET_RX_SUCCESS; 338 339 out: 340 if (primary_if) 341 batadv_hardif_free_ref(primary_if); 342 if (orig_node) 343 batadv_orig_node_free_ref(orig_node); 344 return ret; 345 } 346 347 348 int batadv_recv_icmp_packet(struct sk_buff *skb, 349 struct batadv_hard_iface *recv_if) 350 { 351 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 352 struct batadv_icmp_packet_rr *icmp_packet; 353 struct ethhdr *ethhdr; 354 struct batadv_orig_node *orig_node = NULL; 355 int hdr_size = sizeof(struct batadv_icmp_packet); 356 int ret = NET_RX_DROP; 357 358 /* we truncate all incoming icmp packets if they don't match our size */ 359 if (skb->len >= sizeof(struct batadv_icmp_packet_rr)) 360 hdr_size = sizeof(struct batadv_icmp_packet_rr); 361 362 /* drop packet if it has not necessary minimum size */ 363 if (unlikely(!pskb_may_pull(skb, hdr_size))) 364 goto out; 365 366 ethhdr = eth_hdr(skb); 367 368 /* packet with unicast indication but broadcast recipient */ 369 if (is_broadcast_ether_addr(ethhdr->h_dest)) 370 goto out; 371 372 /* packet with broadcast sender address */ 373 if (is_broadcast_ether_addr(ethhdr->h_source)) 374 goto out; 375 376 /* not for me */ 377 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) 378 goto out; 379 380 icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; 381 382 /* add record route information if not full */ 383 if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) && 384 (icmp_packet->rr_cur < BATADV_RR_LEN)) { 385 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]), 386 ethhdr->h_dest, ETH_ALEN); 387 icmp_packet->rr_cur++; 388 } 389 390 /* packet for me */ 391 if (batadv_is_my_mac(bat_priv, icmp_packet->dst)) 392 return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size); 393 394 /* TTL exceeded */ 395 if (icmp_packet->header.ttl < 2) 396 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb); 397 398 /* get routing information */ 399 orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst); 400 if (!orig_node) 401 goto out; 402 403 /* create a copy of the skb, if needed, to modify it. */ 404 if (skb_cow(skb, ETH_HLEN) < 0) 405 goto out; 406 407 icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; 408 409 /* decrement ttl */ 410 icmp_packet->header.ttl--; 411 412 /* route it */ 413 if (batadv_send_skb_to_orig(skb, orig_node, recv_if) != NET_XMIT_DROP) 414 ret = NET_RX_SUCCESS; 415 416 out: 417 if (orig_node) 418 batadv_orig_node_free_ref(orig_node); 419 return ret; 420 } 421 422 /* In the bonding case, send the packets in a round 423 * robin fashion over the remaining interfaces. 424 * 425 * This method rotates the bonding list and increases the 426 * returned router's refcount. 427 */ 428 static struct batadv_neigh_node * 429 batadv_find_bond_router(struct batadv_orig_node *primary_orig, 430 const struct batadv_hard_iface *recv_if) 431 { 432 struct batadv_neigh_node *tmp_neigh_node; 433 struct batadv_neigh_node *router = NULL, *first_candidate = NULL; 434 435 rcu_read_lock(); 436 list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list, 437 bonding_list) { 438 if (!first_candidate) 439 first_candidate = tmp_neigh_node; 440 441 /* recv_if == NULL on the first node. */ 442 if (tmp_neigh_node->if_incoming == recv_if) 443 continue; 444 445 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) 446 continue; 447 448 router = tmp_neigh_node; 449 break; 450 } 451 452 /* use the first candidate if nothing was found. */ 453 if (!router && first_candidate && 454 atomic_inc_not_zero(&first_candidate->refcount)) 455 router = first_candidate; 456 457 if (!router) 458 goto out; 459 460 /* selected should point to the next element 461 * after the current router 462 */ 463 spin_lock_bh(&primary_orig->neigh_list_lock); 464 /* this is a list_move(), which unfortunately 465 * does not exist as rcu version 466 */ 467 list_del_rcu(&primary_orig->bond_list); 468 list_add_rcu(&primary_orig->bond_list, 469 &router->bonding_list); 470 spin_unlock_bh(&primary_orig->neigh_list_lock); 471 472 out: 473 rcu_read_unlock(); 474 return router; 475 } 476 477 /* Interface Alternating: Use the best of the 478 * remaining candidates which are not using 479 * this interface. 480 * 481 * Increases the returned router's refcount 482 */ 483 static struct batadv_neigh_node * 484 batadv_find_ifalter_router(struct batadv_orig_node *primary_orig, 485 const struct batadv_hard_iface *recv_if) 486 { 487 struct batadv_neigh_node *tmp_neigh_node; 488 struct batadv_neigh_node *router = NULL, *first_candidate = NULL; 489 490 rcu_read_lock(); 491 list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list, 492 bonding_list) { 493 if (!first_candidate) 494 first_candidate = tmp_neigh_node; 495 496 /* recv_if == NULL on the first node. */ 497 if (tmp_neigh_node->if_incoming == recv_if) 498 continue; 499 500 if (router && tmp_neigh_node->tq_avg <= router->tq_avg) 501 continue; 502 503 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) 504 continue; 505 506 /* decrement refcount of previously selected router */ 507 if (router) 508 batadv_neigh_node_free_ref(router); 509 510 /* we found a better router (or at least one valid router) */ 511 router = tmp_neigh_node; 512 } 513 514 /* use the first candidate if nothing was found. */ 515 if (!router && first_candidate && 516 atomic_inc_not_zero(&first_candidate->refcount)) 517 router = first_candidate; 518 519 rcu_read_unlock(); 520 return router; 521 } 522 523 /** 524 * batadv_check_unicast_packet - Check for malformed unicast packets 525 * @bat_priv: the bat priv with all the soft interface information 526 * @skb: packet to check 527 * @hdr_size: size of header to pull 528 * 529 * Check for short header and bad addresses in given packet. Returns negative 530 * value when check fails and 0 otherwise. The negative value depends on the 531 * reason: -ENODATA for bad header, -EBADR for broadcast destination or source, 532 * and -EREMOTE for non-local (other host) destination. 533 */ 534 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv, 535 struct sk_buff *skb, int hdr_size) 536 { 537 struct ethhdr *ethhdr; 538 539 /* drop packet if it has not necessary minimum size */ 540 if (unlikely(!pskb_may_pull(skb, hdr_size))) 541 return -ENODATA; 542 543 ethhdr = eth_hdr(skb); 544 545 /* packet with unicast indication but broadcast recipient */ 546 if (is_broadcast_ether_addr(ethhdr->h_dest)) 547 return -EBADR; 548 549 /* packet with broadcast sender address */ 550 if (is_broadcast_ether_addr(ethhdr->h_source)) 551 return -EBADR; 552 553 /* not for me */ 554 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) 555 return -EREMOTE; 556 557 return 0; 558 } 559 560 int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if) 561 { 562 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 563 struct batadv_tt_query_packet *tt_query; 564 uint16_t tt_size; 565 int hdr_size = sizeof(*tt_query); 566 char tt_flag; 567 size_t packet_size; 568 569 if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) 570 return NET_RX_DROP; 571 572 /* I could need to modify it */ 573 if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0) 574 goto out; 575 576 tt_query = (struct batadv_tt_query_packet *)skb->data; 577 578 switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) { 579 case BATADV_TT_REQUEST: 580 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX); 581 582 /* If we cannot provide an answer the tt_request is 583 * forwarded 584 */ 585 if (!batadv_send_tt_response(bat_priv, tt_query)) { 586 if (tt_query->flags & BATADV_TT_FULL_TABLE) 587 tt_flag = 'F'; 588 else 589 tt_flag = '.'; 590 591 batadv_dbg(BATADV_DBG_TT, bat_priv, 592 "Routing TT_REQUEST to %pM [%c]\n", 593 tt_query->dst, 594 tt_flag); 595 return batadv_route_unicast_packet(skb, recv_if); 596 } 597 break; 598 case BATADV_TT_RESPONSE: 599 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX); 600 601 if (batadv_is_my_mac(bat_priv, tt_query->dst)) { 602 /* packet needs to be linearized to access the TT 603 * changes 604 */ 605 if (skb_linearize(skb) < 0) 606 goto out; 607 /* skb_linearize() possibly changed skb->data */ 608 tt_query = (struct batadv_tt_query_packet *)skb->data; 609 610 tt_size = batadv_tt_len(ntohs(tt_query->tt_data)); 611 612 /* Ensure we have all the claimed data */ 613 packet_size = sizeof(struct batadv_tt_query_packet); 614 packet_size += tt_size; 615 if (unlikely(skb_headlen(skb) < packet_size)) 616 goto out; 617 618 batadv_handle_tt_response(bat_priv, tt_query); 619 } else { 620 if (tt_query->flags & BATADV_TT_FULL_TABLE) 621 tt_flag = 'F'; 622 else 623 tt_flag = '.'; 624 batadv_dbg(BATADV_DBG_TT, bat_priv, 625 "Routing TT_RESPONSE to %pM [%c]\n", 626 tt_query->dst, 627 tt_flag); 628 return batadv_route_unicast_packet(skb, recv_if); 629 } 630 break; 631 } 632 633 out: 634 /* returning NET_RX_DROP will make the caller function kfree the skb */ 635 return NET_RX_DROP; 636 } 637 638 int batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if) 639 { 640 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 641 struct batadv_roam_adv_packet *roam_adv_packet; 642 struct batadv_orig_node *orig_node; 643 644 if (batadv_check_unicast_packet(bat_priv, skb, 645 sizeof(*roam_adv_packet)) < 0) 646 goto out; 647 648 batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX); 649 650 roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data; 651 652 if (!batadv_is_my_mac(bat_priv, roam_adv_packet->dst)) 653 return batadv_route_unicast_packet(skb, recv_if); 654 655 /* check if it is a backbone gateway. we don't accept 656 * roaming advertisement from it, as it has the same 657 * entries as we have. 658 */ 659 if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src)) 660 goto out; 661 662 orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src); 663 if (!orig_node) 664 goto out; 665 666 batadv_dbg(BATADV_DBG_TT, bat_priv, 667 "Received ROAMING_ADV from %pM (client %pM)\n", 668 roam_adv_packet->src, roam_adv_packet->client); 669 670 batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client, 671 BATADV_TT_CLIENT_ROAM, 672 atomic_read(&orig_node->last_ttvn) + 1); 673 674 batadv_orig_node_free_ref(orig_node); 675 out: 676 /* returning NET_RX_DROP will make the caller function kfree the skb */ 677 return NET_RX_DROP; 678 } 679 680 /* find a suitable router for this originator, and use 681 * bonding if possible. increases the found neighbors 682 * refcount. 683 */ 684 struct batadv_neigh_node * 685 batadv_find_router(struct batadv_priv *bat_priv, 686 struct batadv_orig_node *orig_node, 687 const struct batadv_hard_iface *recv_if) 688 { 689 struct batadv_orig_node *primary_orig_node; 690 struct batadv_orig_node *router_orig; 691 struct batadv_neigh_node *router; 692 static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0}; 693 int bonding_enabled; 694 uint8_t *primary_addr; 695 696 if (!orig_node) 697 return NULL; 698 699 router = batadv_orig_node_get_router(orig_node); 700 if (!router) 701 goto err; 702 703 /* without bonding, the first node should 704 * always choose the default router. 705 */ 706 bonding_enabled = atomic_read(&bat_priv->bonding); 707 708 rcu_read_lock(); 709 /* select default router to output */ 710 router_orig = router->orig_node; 711 if (!router_orig) 712 goto err_unlock; 713 714 if ((!recv_if) && (!bonding_enabled)) 715 goto return_router; 716 717 primary_addr = router_orig->primary_addr; 718 719 /* if we have something in the primary_addr, we can search 720 * for a potential bonding candidate. 721 */ 722 if (batadv_compare_eth(primary_addr, zero_mac)) 723 goto return_router; 724 725 /* find the orig_node which has the primary interface. might 726 * even be the same as our router_orig in many cases 727 */ 728 if (batadv_compare_eth(primary_addr, router_orig->orig)) { 729 primary_orig_node = router_orig; 730 } else { 731 primary_orig_node = batadv_orig_hash_find(bat_priv, 732 primary_addr); 733 if (!primary_orig_node) 734 goto return_router; 735 736 batadv_orig_node_free_ref(primary_orig_node); 737 } 738 739 /* with less than 2 candidates, we can't do any 740 * bonding and prefer the original router. 741 */ 742 if (atomic_read(&primary_orig_node->bond_candidates) < 2) 743 goto return_router; 744 745 /* all nodes between should choose a candidate which 746 * is is not on the interface where the packet came 747 * in. 748 */ 749 batadv_neigh_node_free_ref(router); 750 751 if (bonding_enabled) 752 router = batadv_find_bond_router(primary_orig_node, recv_if); 753 else 754 router = batadv_find_ifalter_router(primary_orig_node, recv_if); 755 756 return_router: 757 if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE) 758 goto err_unlock; 759 760 rcu_read_unlock(); 761 return router; 762 err_unlock: 763 rcu_read_unlock(); 764 err: 765 if (router) 766 batadv_neigh_node_free_ref(router); 767 return NULL; 768 } 769 770 static int batadv_route_unicast_packet(struct sk_buff *skb, 771 struct batadv_hard_iface *recv_if) 772 { 773 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 774 struct batadv_orig_node *orig_node = NULL; 775 struct batadv_neigh_node *neigh_node = NULL; 776 struct batadv_unicast_packet *unicast_packet; 777 struct ethhdr *ethhdr = eth_hdr(skb); 778 int res, ret = NET_RX_DROP; 779 struct sk_buff *new_skb; 780 781 unicast_packet = (struct batadv_unicast_packet *)skb->data; 782 783 /* TTL exceeded */ 784 if (unicast_packet->header.ttl < 2) { 785 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", 786 ethhdr->h_source, unicast_packet->dest); 787 goto out; 788 } 789 790 /* get routing information */ 791 orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); 792 793 if (!orig_node) 794 goto out; 795 796 /* find_router() increases neigh_nodes refcount if found. */ 797 neigh_node = batadv_find_router(bat_priv, orig_node, recv_if); 798 799 if (!neigh_node) 800 goto out; 801 802 /* create a copy of the skb, if needed, to modify it. */ 803 if (skb_cow(skb, ETH_HLEN) < 0) 804 goto out; 805 806 unicast_packet = (struct batadv_unicast_packet *)skb->data; 807 808 if (unicast_packet->header.packet_type == BATADV_UNICAST && 809 atomic_read(&bat_priv->fragmentation) && 810 skb->len > neigh_node->if_incoming->net_dev->mtu) { 811 ret = batadv_frag_send_skb(skb, bat_priv, 812 neigh_node->if_incoming, 813 neigh_node->addr); 814 goto out; 815 } 816 817 if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG && 818 batadv_frag_can_reassemble(skb, 819 neigh_node->if_incoming->net_dev->mtu)) { 820 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb); 821 822 if (ret == NET_RX_DROP) 823 goto out; 824 825 /* packet was buffered for late merge */ 826 if (!new_skb) { 827 ret = NET_RX_SUCCESS; 828 goto out; 829 } 830 831 skb = new_skb; 832 unicast_packet = (struct batadv_unicast_packet *)skb->data; 833 } 834 835 /* decrement ttl */ 836 unicast_packet->header.ttl--; 837 838 res = batadv_send_skb_to_orig(skb, orig_node, recv_if); 839 840 /* translate transmit result into receive result */ 841 if (res == NET_XMIT_SUCCESS) { 842 /* skb was transmitted and consumed */ 843 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); 844 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, 845 skb->len + ETH_HLEN); 846 847 ret = NET_RX_SUCCESS; 848 } else if (res == NET_XMIT_POLICED) { 849 /* skb was buffered and consumed */ 850 ret = NET_RX_SUCCESS; 851 } 852 853 out: 854 if (neigh_node) 855 batadv_neigh_node_free_ref(neigh_node); 856 if (orig_node) 857 batadv_orig_node_free_ref(orig_node); 858 return ret; 859 } 860 861 /** 862 * batadv_reroute_unicast_packet - update the unicast header for re-routing 863 * @bat_priv: the bat priv with all the soft interface information 864 * @unicast_packet: the unicast header to be updated 865 * @dst_addr: the payload destination 866 * 867 * Search the translation table for dst_addr and update the unicast header with 868 * the new corresponding information (originator address where the destination 869 * client currently is and its known TTVN) 870 * 871 * Returns true if the packet header has been updated, false otherwise 872 */ 873 static bool 874 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, 875 struct batadv_unicast_packet *unicast_packet, 876 uint8_t *dst_addr) 877 { 878 struct batadv_orig_node *orig_node = NULL; 879 struct batadv_hard_iface *primary_if = NULL; 880 bool ret = false; 881 uint8_t *orig_addr, orig_ttvn; 882 883 if (batadv_is_my_client(bat_priv, dst_addr)) { 884 primary_if = batadv_primary_if_get_selected(bat_priv); 885 if (!primary_if) 886 goto out; 887 orig_addr = primary_if->net_dev->dev_addr; 888 orig_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn); 889 } else { 890 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr); 891 if (!orig_node) 892 goto out; 893 894 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest)) 895 goto out; 896 897 orig_addr = orig_node->orig; 898 orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); 899 } 900 901 /* update the packet header */ 902 memcpy(unicast_packet->dest, orig_addr, ETH_ALEN); 903 unicast_packet->ttvn = orig_ttvn; 904 905 ret = true; 906 out: 907 if (primary_if) 908 batadv_hardif_free_ref(primary_if); 909 if (orig_node) 910 batadv_orig_node_free_ref(orig_node); 911 912 return ret; 913 } 914 915 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, 916 struct sk_buff *skb, int hdr_len) { 917 uint8_t curr_ttvn, old_ttvn; 918 struct batadv_orig_node *orig_node; 919 struct ethhdr *ethhdr; 920 struct batadv_hard_iface *primary_if; 921 struct batadv_unicast_packet *unicast_packet; 922 int is_old_ttvn; 923 924 /* check if there is enough data before accessing it */ 925 if (pskb_may_pull(skb, hdr_len + ETH_HLEN) < 0) 926 return 0; 927 928 /* create a copy of the skb (in case of for re-routing) to modify it. */ 929 if (skb_cow(skb, sizeof(*unicast_packet)) < 0) 930 return 0; 931 932 unicast_packet = (struct batadv_unicast_packet *)skb->data; 933 ethhdr = (struct ethhdr *)(skb->data + hdr_len); 934 935 /* check if the destination client was served by this node and it is now 936 * roaming. In this case, it means that the node has got a ROAM_ADV 937 * message and that it knows the new destination in the mesh to re-route 938 * the packet to 939 */ 940 if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest)) { 941 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, 942 ethhdr->h_dest)) 943 net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, 944 bat_priv, 945 "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n", 946 unicast_packet->dest, 947 ethhdr->h_dest); 948 /* at this point the mesh destination should have been 949 * substituted with the originator address found in the global 950 * table. If not, let the packet go untouched anyway because 951 * there is nothing the node can do 952 */ 953 return 1; 954 } 955 956 /* retrieve the TTVN known by this node for the packet destination. This 957 * value is used later to check if the node which sent (or re-routed 958 * last time) the packet had an updated information or not 959 */ 960 curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn); 961 if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) { 962 orig_node = batadv_orig_hash_find(bat_priv, 963 unicast_packet->dest); 964 /* if it is not possible to find the orig_node representing the 965 * destination, the packet can immediately be dropped as it will 966 * not be possible to deliver it 967 */ 968 if (!orig_node) 969 return 0; 970 971 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); 972 batadv_orig_node_free_ref(orig_node); 973 } 974 975 /* check if the TTVN contained in the packet is fresher than what the 976 * node knows 977 */ 978 is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); 979 if (!is_old_ttvn) 980 return 1; 981 982 old_ttvn = unicast_packet->ttvn; 983 /* the packet was forged based on outdated network information. Its 984 * destination can possibly be updated and forwarded towards the new 985 * target host 986 */ 987 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, 988 ethhdr->h_dest)) { 989 net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv, 990 "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", 991 unicast_packet->dest, ethhdr->h_dest, 992 old_ttvn, curr_ttvn); 993 return 1; 994 } 995 996 /* the packet has not been re-routed: either the destination is 997 * currently served by this node or there is no destination at all and 998 * it is possible to drop the packet 999 */ 1000 if (!batadv_is_my_client(bat_priv, ethhdr->h_dest)) 1001 return 0; 1002 1003 /* update the header in order to let the packet be delivered to this 1004 * node's soft interface 1005 */ 1006 primary_if = batadv_primary_if_get_selected(bat_priv); 1007 if (!primary_if) 1008 return 0; 1009 1010 memcpy(unicast_packet->dest, primary_if->net_dev->dev_addr, ETH_ALEN); 1011 1012 batadv_hardif_free_ref(primary_if); 1013 1014 unicast_packet->ttvn = curr_ttvn; 1015 1016 return 1; 1017 } 1018 1019 int batadv_recv_unicast_packet(struct sk_buff *skb, 1020 struct batadv_hard_iface *recv_if) 1021 { 1022 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 1023 struct batadv_unicast_packet *unicast_packet; 1024 struct batadv_unicast_4addr_packet *unicast_4addr_packet; 1025 uint8_t *orig_addr; 1026 struct batadv_orig_node *orig_node = NULL; 1027 int check, hdr_size = sizeof(*unicast_packet); 1028 bool is4addr; 1029 1030 unicast_packet = (struct batadv_unicast_packet *)skb->data; 1031 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; 1032 1033 is4addr = unicast_packet->header.packet_type == BATADV_UNICAST_4ADDR; 1034 /* the caller function should have already pulled 2 bytes */ 1035 if (is4addr) 1036 hdr_size = sizeof(*unicast_4addr_packet); 1037 1038 /* function returns -EREMOTE for promiscuous packets */ 1039 check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); 1040 1041 /* Even though the packet is not for us, we might save it to use for 1042 * decoding a later received coded packet 1043 */ 1044 if (check == -EREMOTE) 1045 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb); 1046 1047 if (check < 0) 1048 return NET_RX_DROP; 1049 if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) 1050 return NET_RX_DROP; 1051 1052 /* packet for me */ 1053 if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { 1054 if (is4addr) { 1055 batadv_dat_inc_counter(bat_priv, 1056 unicast_4addr_packet->subtype); 1057 orig_addr = unicast_4addr_packet->src; 1058 orig_node = batadv_orig_hash_find(bat_priv, orig_addr); 1059 } 1060 1061 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, 1062 hdr_size)) 1063 goto rx_success; 1064 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, 1065 hdr_size)) 1066 goto rx_success; 1067 1068 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, 1069 orig_node); 1070 1071 rx_success: 1072 if (orig_node) 1073 batadv_orig_node_free_ref(orig_node); 1074 1075 return NET_RX_SUCCESS; 1076 } 1077 1078 return batadv_route_unicast_packet(skb, recv_if); 1079 } 1080 1081 int batadv_recv_ucast_frag_packet(struct sk_buff *skb, 1082 struct batadv_hard_iface *recv_if) 1083 { 1084 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 1085 struct batadv_unicast_frag_packet *unicast_packet; 1086 int hdr_size = sizeof(*unicast_packet); 1087 struct sk_buff *new_skb = NULL; 1088 int ret; 1089 1090 if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) 1091 return NET_RX_DROP; 1092 1093 if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) 1094 return NET_RX_DROP; 1095 1096 unicast_packet = (struct batadv_unicast_frag_packet *)skb->data; 1097 1098 /* packet for me */ 1099 if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { 1100 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb); 1101 1102 if (ret == NET_RX_DROP) 1103 return NET_RX_DROP; 1104 1105 /* packet was buffered for late merge */ 1106 if (!new_skb) 1107 return NET_RX_SUCCESS; 1108 1109 if (batadv_dat_snoop_incoming_arp_request(bat_priv, new_skb, 1110 hdr_size)) 1111 goto rx_success; 1112 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, new_skb, 1113 hdr_size)) 1114 goto rx_success; 1115 1116 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if, 1117 sizeof(struct batadv_unicast_packet), NULL); 1118 1119 rx_success: 1120 return NET_RX_SUCCESS; 1121 } 1122 1123 return batadv_route_unicast_packet(skb, recv_if); 1124 } 1125 1126 1127 int batadv_recv_bcast_packet(struct sk_buff *skb, 1128 struct batadv_hard_iface *recv_if) 1129 { 1130 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 1131 struct batadv_orig_node *orig_node = NULL; 1132 struct batadv_bcast_packet *bcast_packet; 1133 struct ethhdr *ethhdr; 1134 int hdr_size = sizeof(*bcast_packet); 1135 int ret = NET_RX_DROP; 1136 int32_t seq_diff; 1137 1138 /* drop packet if it has not necessary minimum size */ 1139 if (unlikely(!pskb_may_pull(skb, hdr_size))) 1140 goto out; 1141 1142 ethhdr = eth_hdr(skb); 1143 1144 /* packet with broadcast indication but unicast recipient */ 1145 if (!is_broadcast_ether_addr(ethhdr->h_dest)) 1146 goto out; 1147 1148 /* packet with broadcast sender address */ 1149 if (is_broadcast_ether_addr(ethhdr->h_source)) 1150 goto out; 1151 1152 /* ignore broadcasts sent by myself */ 1153 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 1154 goto out; 1155 1156 bcast_packet = (struct batadv_bcast_packet *)skb->data; 1157 1158 /* ignore broadcasts originated by myself */ 1159 if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) 1160 goto out; 1161 1162 if (bcast_packet->header.ttl < 2) 1163 goto out; 1164 1165 orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig); 1166 1167 if (!orig_node) 1168 goto out; 1169 1170 spin_lock_bh(&orig_node->bcast_seqno_lock); 1171 1172 /* check whether the packet is a duplicate */ 1173 if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno, 1174 ntohl(bcast_packet->seqno))) 1175 goto spin_unlock; 1176 1177 seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno; 1178 1179 /* check whether the packet is old and the host just restarted. */ 1180 if (batadv_window_protected(bat_priv, seq_diff, 1181 &orig_node->bcast_seqno_reset)) 1182 goto spin_unlock; 1183 1184 /* mark broadcast in flood history, update window position 1185 * if required. 1186 */ 1187 if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1)) 1188 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno); 1189 1190 spin_unlock_bh(&orig_node->bcast_seqno_lock); 1191 1192 /* check whether this has been sent by another originator before */ 1193 if (batadv_bla_check_bcast_duplist(bat_priv, skb)) 1194 goto out; 1195 1196 /* rebroadcast packet */ 1197 batadv_add_bcast_packet_to_list(bat_priv, skb, 1); 1198 1199 /* don't hand the broadcast up if it is from an originator 1200 * from the same backbone. 1201 */ 1202 if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) 1203 goto out; 1204 1205 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) 1206 goto rx_success; 1207 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) 1208 goto rx_success; 1209 1210 /* broadcast for me */ 1211 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, 1212 orig_node); 1213 1214 rx_success: 1215 ret = NET_RX_SUCCESS; 1216 goto out; 1217 1218 spin_unlock: 1219 spin_unlock_bh(&orig_node->bcast_seqno_lock); 1220 out: 1221 if (orig_node) 1222 batadv_orig_node_free_ref(orig_node); 1223 return ret; 1224 } 1225 1226 int batadv_recv_vis_packet(struct sk_buff *skb, 1227 struct batadv_hard_iface *recv_if) 1228 { 1229 struct batadv_vis_packet *vis_packet; 1230 struct ethhdr *ethhdr; 1231 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 1232 int hdr_size = sizeof(*vis_packet); 1233 1234 /* keep skb linear */ 1235 if (skb_linearize(skb) < 0) 1236 return NET_RX_DROP; 1237 1238 if (unlikely(!pskb_may_pull(skb, hdr_size))) 1239 return NET_RX_DROP; 1240 1241 vis_packet = (struct batadv_vis_packet *)skb->data; 1242 ethhdr = eth_hdr(skb); 1243 1244 /* not for me */ 1245 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) 1246 return NET_RX_DROP; 1247 1248 /* ignore own packets */ 1249 if (batadv_is_my_mac(bat_priv, vis_packet->vis_orig)) 1250 return NET_RX_DROP; 1251 1252 if (batadv_is_my_mac(bat_priv, vis_packet->sender_orig)) 1253 return NET_RX_DROP; 1254 1255 switch (vis_packet->vis_type) { 1256 case BATADV_VIS_TYPE_SERVER_SYNC: 1257 batadv_receive_server_sync_packet(bat_priv, vis_packet, 1258 skb_headlen(skb)); 1259 break; 1260 1261 case BATADV_VIS_TYPE_CLIENT_UPDATE: 1262 batadv_receive_client_update_packet(bat_priv, vis_packet, 1263 skb_headlen(skb)); 1264 break; 1265 1266 default: /* ignore unknown packet */ 1267 break; 1268 } 1269 1270 /* We take a copy of the data in the packet, so we should 1271 * always free the skbuf. 1272 */ 1273 return NET_RX_DROP; 1274 } 1275