1 /* Copyright (C) 2009-2012 B.A.T.M.A.N. contributors: 2 * 3 * Marek Lindner 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 "sysfs.h" 22 #include "gateway_client.h" 23 #include "gateway_common.h" 24 #include "hard-interface.h" 25 #include "originator.h" 26 #include "translation-table.h" 27 #include "routing.h" 28 #include <linux/ip.h> 29 #include <linux/ipv6.h> 30 #include <linux/udp.h> 31 #include <linux/if_vlan.h> 32 33 /* This is the offset of the options field in a dhcp packet starting at 34 * the beginning of the dhcp header 35 */ 36 #define BATADV_DHCP_OPTIONS_OFFSET 240 37 #define BATADV_DHCP_REQUEST 3 38 39 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) 40 { 41 if (atomic_dec_and_test(&gw_node->refcount)) 42 kfree_rcu(gw_node, rcu); 43 } 44 45 static struct batadv_gw_node * 46 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv) 47 { 48 struct batadv_gw_node *gw_node; 49 50 rcu_read_lock(); 51 gw_node = rcu_dereference(bat_priv->curr_gw); 52 if (!gw_node) 53 goto out; 54 55 if (!atomic_inc_not_zero(&gw_node->refcount)) 56 gw_node = NULL; 57 58 out: 59 rcu_read_unlock(); 60 return gw_node; 61 } 62 63 struct batadv_orig_node * 64 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv) 65 { 66 struct batadv_gw_node *gw_node; 67 struct batadv_orig_node *orig_node = NULL; 68 69 gw_node = batadv_gw_get_selected_gw_node(bat_priv); 70 if (!gw_node) 71 goto out; 72 73 rcu_read_lock(); 74 orig_node = gw_node->orig_node; 75 if (!orig_node) 76 goto unlock; 77 78 if (!atomic_inc_not_zero(&orig_node->refcount)) 79 orig_node = NULL; 80 81 unlock: 82 rcu_read_unlock(); 83 out: 84 if (gw_node) 85 batadv_gw_node_free_ref(gw_node); 86 return orig_node; 87 } 88 89 static void batadv_gw_select(struct batadv_priv *bat_priv, 90 struct batadv_gw_node *new_gw_node) 91 { 92 struct batadv_gw_node *curr_gw_node; 93 94 spin_lock_bh(&bat_priv->gw_list_lock); 95 96 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount)) 97 new_gw_node = NULL; 98 99 curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1); 100 rcu_assign_pointer(bat_priv->curr_gw, new_gw_node); 101 102 if (curr_gw_node) 103 batadv_gw_node_free_ref(curr_gw_node); 104 105 spin_unlock_bh(&bat_priv->gw_list_lock); 106 } 107 108 void batadv_gw_deselect(struct batadv_priv *bat_priv) 109 { 110 atomic_set(&bat_priv->gw_reselect, 1); 111 } 112 113 static struct batadv_gw_node * 114 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv) 115 { 116 struct batadv_neigh_node *router; 117 struct hlist_node *node; 118 struct batadv_gw_node *gw_node, *curr_gw = NULL; 119 uint32_t max_gw_factor = 0, tmp_gw_factor = 0; 120 uint8_t max_tq = 0; 121 int down, up; 122 struct batadv_orig_node *orig_node; 123 124 rcu_read_lock(); 125 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { 126 if (gw_node->deleted) 127 continue; 128 129 orig_node = gw_node->orig_node; 130 router = batadv_orig_node_get_router(orig_node); 131 if (!router) 132 continue; 133 134 if (!atomic_inc_not_zero(&gw_node->refcount)) 135 goto next; 136 137 switch (atomic_read(&bat_priv->gw_sel_class)) { 138 case 1: /* fast connection */ 139 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags, 140 &down, &up); 141 142 tmp_gw_factor = (router->tq_avg * router->tq_avg * 143 down * 100 * 100) / 144 (BATADV_TQ_LOCAL_WINDOW_SIZE * 145 BATADV_TQ_LOCAL_WINDOW_SIZE * 64); 146 147 if ((tmp_gw_factor > max_gw_factor) || 148 ((tmp_gw_factor == max_gw_factor) && 149 (router->tq_avg > max_tq))) { 150 if (curr_gw) 151 batadv_gw_node_free_ref(curr_gw); 152 curr_gw = gw_node; 153 atomic_inc(&curr_gw->refcount); 154 } 155 break; 156 157 default: /* 2: stable connection (use best statistic) 158 * 3: fast-switch (use best statistic but change as 159 * soon as a better gateway appears) 160 * XX: late-switch (use best statistic but change as 161 * soon as a better gateway appears which has 162 * $routing_class more tq points) 163 */ 164 if (router->tq_avg > max_tq) { 165 if (curr_gw) 166 batadv_gw_node_free_ref(curr_gw); 167 curr_gw = gw_node; 168 atomic_inc(&curr_gw->refcount); 169 } 170 break; 171 } 172 173 if (router->tq_avg > max_tq) 174 max_tq = router->tq_avg; 175 176 if (tmp_gw_factor > max_gw_factor) 177 max_gw_factor = tmp_gw_factor; 178 179 batadv_gw_node_free_ref(gw_node); 180 181 next: 182 batadv_neigh_node_free_ref(router); 183 } 184 rcu_read_unlock(); 185 186 return curr_gw; 187 } 188 189 void batadv_gw_election(struct batadv_priv *bat_priv) 190 { 191 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL; 192 struct batadv_neigh_node *router = NULL; 193 char gw_addr[18] = { '\0' }; 194 195 /* The batman daemon checks here if we already passed a full originator 196 * cycle in order to make sure we don't choose the first gateway we 197 * hear about. This check is based on the daemon's uptime which we 198 * don't have. 199 */ 200 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT) 201 goto out; 202 203 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 204 205 if (!batadv_atomic_dec_not_zero(&bat_priv->gw_reselect) && curr_gw) 206 goto out; 207 208 next_gw = batadv_gw_get_best_gw_node(bat_priv); 209 210 if (curr_gw == next_gw) 211 goto out; 212 213 if (next_gw) { 214 sprintf(gw_addr, "%pM", next_gw->orig_node->orig); 215 216 router = batadv_orig_node_get_router(next_gw->orig_node); 217 if (!router) { 218 batadv_gw_deselect(bat_priv); 219 goto out; 220 } 221 } 222 223 if ((curr_gw) && (!next_gw)) { 224 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 225 "Removing selected gateway - no gateway in range\n"); 226 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, 227 NULL); 228 } else if ((!curr_gw) && (next_gw)) { 229 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 230 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n", 231 next_gw->orig_node->orig, 232 next_gw->orig_node->gw_flags, router->tq_avg); 233 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD, 234 gw_addr); 235 } else { 236 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 237 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n", 238 next_gw->orig_node->orig, 239 next_gw->orig_node->gw_flags, router->tq_avg); 240 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE, 241 gw_addr); 242 } 243 244 batadv_gw_select(bat_priv, next_gw); 245 246 out: 247 if (curr_gw) 248 batadv_gw_node_free_ref(curr_gw); 249 if (next_gw) 250 batadv_gw_node_free_ref(next_gw); 251 if (router) 252 batadv_neigh_node_free_ref(router); 253 } 254 255 void batadv_gw_check_election(struct batadv_priv *bat_priv, 256 struct batadv_orig_node *orig_node) 257 { 258 struct batadv_orig_node *curr_gw_orig; 259 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL; 260 uint8_t gw_tq_avg, orig_tq_avg; 261 262 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv); 263 if (!curr_gw_orig) 264 goto deselect; 265 266 router_gw = batadv_orig_node_get_router(curr_gw_orig); 267 if (!router_gw) 268 goto deselect; 269 270 /* this node already is the gateway */ 271 if (curr_gw_orig == orig_node) 272 goto out; 273 274 router_orig = batadv_orig_node_get_router(orig_node); 275 if (!router_orig) 276 goto out; 277 278 gw_tq_avg = router_gw->tq_avg; 279 orig_tq_avg = router_orig->tq_avg; 280 281 /* the TQ value has to be better */ 282 if (orig_tq_avg < gw_tq_avg) 283 goto out; 284 285 /* if the routing class is greater than 3 the value tells us how much 286 * greater the TQ value of the new gateway must be 287 */ 288 if ((atomic_read(&bat_priv->gw_sel_class) > 3) && 289 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class))) 290 goto out; 291 292 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 293 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n", 294 gw_tq_avg, orig_tq_avg); 295 296 deselect: 297 batadv_gw_deselect(bat_priv); 298 out: 299 if (curr_gw_orig) 300 batadv_orig_node_free_ref(curr_gw_orig); 301 if (router_gw) 302 batadv_neigh_node_free_ref(router_gw); 303 if (router_orig) 304 batadv_neigh_node_free_ref(router_orig); 305 306 return; 307 } 308 309 static void batadv_gw_node_add(struct batadv_priv *bat_priv, 310 struct batadv_orig_node *orig_node, 311 uint8_t new_gwflags) 312 { 313 struct batadv_gw_node *gw_node; 314 int down, up; 315 316 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC); 317 if (!gw_node) 318 return; 319 320 INIT_HLIST_NODE(&gw_node->list); 321 gw_node->orig_node = orig_node; 322 atomic_set(&gw_node->refcount, 1); 323 324 spin_lock_bh(&bat_priv->gw_list_lock); 325 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list); 326 spin_unlock_bh(&bat_priv->gw_list_lock); 327 328 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up); 329 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 330 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n", 331 orig_node->orig, new_gwflags, 332 (down > 2048 ? down / 1024 : down), 333 (down > 2048 ? "MBit" : "KBit"), 334 (up > 2048 ? up / 1024 : up), 335 (up > 2048 ? "MBit" : "KBit")); 336 } 337 338 void batadv_gw_node_update(struct batadv_priv *bat_priv, 339 struct batadv_orig_node *orig_node, 340 uint8_t new_gwflags) 341 { 342 struct hlist_node *node; 343 struct batadv_gw_node *gw_node, *curr_gw; 344 345 /* Note: We don't need a NULL check here, since curr_gw never gets 346 * dereferenced. If curr_gw is NULL we also should not exit as we may 347 * have this gateway in our list (duplication check!) even though we 348 * have no currently selected gateway. 349 */ 350 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 351 352 rcu_read_lock(); 353 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { 354 if (gw_node->orig_node != orig_node) 355 continue; 356 357 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 358 "Gateway class of originator %pM changed from %i to %i\n", 359 orig_node->orig, gw_node->orig_node->gw_flags, 360 new_gwflags); 361 362 gw_node->deleted = 0; 363 364 if (new_gwflags == BATADV_NO_FLAGS) { 365 gw_node->deleted = jiffies; 366 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 367 "Gateway %pM removed from gateway list\n", 368 orig_node->orig); 369 370 if (gw_node == curr_gw) 371 goto deselect; 372 } 373 374 goto unlock; 375 } 376 377 if (new_gwflags == BATADV_NO_FLAGS) 378 goto unlock; 379 380 batadv_gw_node_add(bat_priv, orig_node, new_gwflags); 381 goto unlock; 382 383 deselect: 384 batadv_gw_deselect(bat_priv); 385 unlock: 386 rcu_read_unlock(); 387 388 if (curr_gw) 389 batadv_gw_node_free_ref(curr_gw); 390 } 391 392 void batadv_gw_node_delete(struct batadv_priv *bat_priv, 393 struct batadv_orig_node *orig_node) 394 { 395 batadv_gw_node_update(bat_priv, orig_node, 0); 396 } 397 398 void batadv_gw_node_purge(struct batadv_priv *bat_priv) 399 { 400 struct batadv_gw_node *gw_node, *curr_gw; 401 struct hlist_node *node, *node_tmp; 402 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT); 403 int do_deselect = 0; 404 405 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 406 407 spin_lock_bh(&bat_priv->gw_list_lock); 408 409 hlist_for_each_entry_safe(gw_node, node, node_tmp, 410 &bat_priv->gw_list, list) { 411 if (((!gw_node->deleted) || 412 (time_before(jiffies, gw_node->deleted + timeout))) && 413 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE) 414 continue; 415 416 if (curr_gw == gw_node) 417 do_deselect = 1; 418 419 hlist_del_rcu(&gw_node->list); 420 batadv_gw_node_free_ref(gw_node); 421 } 422 423 spin_unlock_bh(&bat_priv->gw_list_lock); 424 425 /* gw_deselect() needs to acquire the gw_list_lock */ 426 if (do_deselect) 427 batadv_gw_deselect(bat_priv); 428 429 if (curr_gw) 430 batadv_gw_node_free_ref(curr_gw); 431 } 432 433 /* fails if orig_node has no router */ 434 static int batadv_write_buffer_text(struct batadv_priv *bat_priv, 435 struct seq_file *seq, 436 const struct batadv_gw_node *gw_node) 437 { 438 struct batadv_gw_node *curr_gw; 439 struct batadv_neigh_node *router; 440 int down, up, ret = -1; 441 442 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up); 443 444 router = batadv_orig_node_get_router(gw_node->orig_node); 445 if (!router) 446 goto out; 447 448 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 449 450 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n", 451 (curr_gw == gw_node ? "=>" : " "), 452 gw_node->orig_node->orig, 453 router->tq_avg, router->addr, 454 router->if_incoming->net_dev->name, 455 gw_node->orig_node->gw_flags, 456 (down > 2048 ? down / 1024 : down), 457 (down > 2048 ? "MBit" : "KBit"), 458 (up > 2048 ? up / 1024 : up), 459 (up > 2048 ? "MBit" : "KBit")); 460 461 batadv_neigh_node_free_ref(router); 462 if (curr_gw) 463 batadv_gw_node_free_ref(curr_gw); 464 out: 465 return ret; 466 } 467 468 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset) 469 { 470 struct net_device *net_dev = (struct net_device *)seq->private; 471 struct batadv_priv *bat_priv = netdev_priv(net_dev); 472 struct batadv_hard_iface *primary_if; 473 struct batadv_gw_node *gw_node; 474 struct hlist_node *node; 475 int gw_count = 0, ret = 0; 476 477 primary_if = batadv_primary_if_get_selected(bat_priv); 478 if (!primary_if) { 479 ret = seq_printf(seq, 480 "BATMAN mesh %s disabled - please specify interfaces to enable it\n", 481 net_dev->name); 482 goto out; 483 } 484 485 if (primary_if->if_status != BATADV_IF_ACTIVE) { 486 ret = seq_printf(seq, 487 "BATMAN mesh %s disabled - primary interface not active\n", 488 net_dev->name); 489 goto out; 490 } 491 492 seq_printf(seq, 493 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n", 494 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF", 495 BATADV_SOURCE_VERSION, primary_if->net_dev->name, 496 primary_if->net_dev->dev_addr, net_dev->name); 497 498 rcu_read_lock(); 499 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { 500 if (gw_node->deleted) 501 continue; 502 503 /* fails if orig_node has no router */ 504 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0) 505 continue; 506 507 gw_count++; 508 } 509 rcu_read_unlock(); 510 511 if (gw_count == 0) 512 seq_printf(seq, "No gateways in range ...\n"); 513 514 out: 515 if (primary_if) 516 batadv_hardif_free_ref(primary_if); 517 return ret; 518 } 519 520 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len) 521 { 522 int ret = false; 523 unsigned char *p; 524 int pkt_len; 525 526 if (skb_linearize(skb) < 0) 527 goto out; 528 529 pkt_len = skb_headlen(skb); 530 531 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1) 532 goto out; 533 534 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET; 535 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1; 536 537 /* Access the dhcp option lists. Each entry is made up by: 538 * - octet 1: option type 539 * - octet 2: option data len (only if type != 255 and 0) 540 * - octet 3: option data 541 */ 542 while (*p != 255 && !ret) { 543 /* p now points to the first octet: option type */ 544 if (*p == 53) { 545 /* type 53 is the message type option. 546 * Jump the len octet and go to the data octet 547 */ 548 if (pkt_len < 2) 549 goto out; 550 p += 2; 551 552 /* check if the message type is what we need */ 553 if (*p == BATADV_DHCP_REQUEST) 554 ret = true; 555 break; 556 } else if (*p == 0) { 557 /* option type 0 (padding), just go forward */ 558 if (pkt_len < 1) 559 goto out; 560 pkt_len--; 561 p++; 562 } else { 563 /* This is any other option. So we get the length... */ 564 if (pkt_len < 1) 565 goto out; 566 pkt_len--; 567 p++; 568 569 /* ...and then we jump over the data */ 570 if (pkt_len < 1 + (*p)) 571 goto out; 572 pkt_len -= 1 + (*p); 573 p += 1 + (*p); 574 } 575 } 576 out: 577 return ret; 578 } 579 580 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) 581 { 582 struct ethhdr *ethhdr; 583 struct iphdr *iphdr; 584 struct ipv6hdr *ipv6hdr; 585 struct udphdr *udphdr; 586 587 /* check for ethernet header */ 588 if (!pskb_may_pull(skb, *header_len + ETH_HLEN)) 589 return false; 590 ethhdr = (struct ethhdr *)skb->data; 591 *header_len += ETH_HLEN; 592 593 /* check for initial vlan header */ 594 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { 595 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN)) 596 return false; 597 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN); 598 *header_len += VLAN_HLEN; 599 } 600 601 /* check for ip header */ 602 switch (ntohs(ethhdr->h_proto)) { 603 case ETH_P_IP: 604 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr))) 605 return false; 606 iphdr = (struct iphdr *)(skb->data + *header_len); 607 *header_len += iphdr->ihl * 4; 608 609 /* check for udp header */ 610 if (iphdr->protocol != IPPROTO_UDP) 611 return false; 612 613 break; 614 case ETH_P_IPV6: 615 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr))) 616 return false; 617 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len); 618 *header_len += sizeof(*ipv6hdr); 619 620 /* check for udp header */ 621 if (ipv6hdr->nexthdr != IPPROTO_UDP) 622 return false; 623 624 break; 625 default: 626 return false; 627 } 628 629 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr))) 630 return false; 631 udphdr = (struct udphdr *)(skb->data + *header_len); 632 *header_len += sizeof(*udphdr); 633 634 /* check for bootp port */ 635 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) && 636 (ntohs(udphdr->dest) != 67)) 637 return false; 638 639 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) && 640 (ntohs(udphdr->dest) != 547)) 641 return false; 642 643 return true; 644 } 645 646 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, 647 struct sk_buff *skb, struct ethhdr *ethhdr) 648 { 649 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL; 650 struct batadv_orig_node *orig_dst_node = NULL; 651 struct batadv_gw_node *curr_gw = NULL; 652 bool ret, out_of_range = false; 653 unsigned int header_len = 0; 654 uint8_t curr_tq_avg; 655 656 ret = batadv_gw_is_dhcp_target(skb, &header_len); 657 if (!ret) 658 goto out; 659 660 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source, 661 ethhdr->h_dest); 662 if (!orig_dst_node) 663 goto out; 664 665 if (!orig_dst_node->gw_flags) 666 goto out; 667 668 ret = batadv_is_type_dhcprequest(skb, header_len); 669 if (!ret) 670 goto out; 671 672 switch (atomic_read(&bat_priv->gw_mode)) { 673 case BATADV_GW_MODE_SERVER: 674 /* If we are a GW then we are our best GW. We can artificially 675 * set the tq towards ourself as the maximum value 676 */ 677 curr_tq_avg = BATADV_TQ_MAX_VALUE; 678 break; 679 case BATADV_GW_MODE_CLIENT: 680 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 681 if (!curr_gw) 682 goto out; 683 684 /* packet is going to our gateway */ 685 if (curr_gw->orig_node == orig_dst_node) 686 goto out; 687 688 /* If the dhcp packet has been sent to a different gw, 689 * we have to evaluate whether the old gw is still 690 * reliable enough 691 */ 692 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node, 693 NULL); 694 if (!neigh_curr) 695 goto out; 696 697 curr_tq_avg = neigh_curr->tq_avg; 698 break; 699 case BATADV_GW_MODE_OFF: 700 default: 701 goto out; 702 } 703 704 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL); 705 if (!neigh_old) 706 goto out; 707 708 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD) 709 out_of_range = true; 710 711 out: 712 if (orig_dst_node) 713 batadv_orig_node_free_ref(orig_dst_node); 714 if (curr_gw) 715 batadv_gw_node_free_ref(curr_gw); 716 if (neigh_old) 717 batadv_neigh_node_free_ref(neigh_old); 718 if (neigh_curr) 719 batadv_neigh_node_free_ref(neigh_curr); 720 return out_of_range; 721 } 722