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