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->gw.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->gw.curr_gw, 1); 100 rcu_assign_pointer(bat_priv->gw.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 uint32_t gw_divisor; 121 uint8_t max_tq = 0; 122 int down, up; 123 uint8_t tq_avg; 124 struct batadv_orig_node *orig_node; 125 126 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE; 127 gw_divisor *= 64; 128 129 rcu_read_lock(); 130 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) { 131 if (gw_node->deleted) 132 continue; 133 134 orig_node = gw_node->orig_node; 135 router = batadv_orig_node_get_router(orig_node); 136 if (!router) 137 continue; 138 139 if (!atomic_inc_not_zero(&gw_node->refcount)) 140 goto next; 141 142 tq_avg = router->tq_avg; 143 144 switch (atomic_read(&bat_priv->gw_sel_class)) { 145 case 1: /* fast connection */ 146 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags, 147 &down, &up); 148 149 tmp_gw_factor = tq_avg * tq_avg * down * 100 * 100; 150 tmp_gw_factor /= gw_divisor; 151 152 if ((tmp_gw_factor > max_gw_factor) || 153 ((tmp_gw_factor == max_gw_factor) && 154 (tq_avg > max_tq))) { 155 if (curr_gw) 156 batadv_gw_node_free_ref(curr_gw); 157 curr_gw = gw_node; 158 atomic_inc(&curr_gw->refcount); 159 } 160 break; 161 162 default: /* 2: stable connection (use best statistic) 163 * 3: fast-switch (use best statistic but change as 164 * soon as a better gateway appears) 165 * XX: late-switch (use best statistic but change as 166 * soon as a better gateway appears which has 167 * $routing_class more tq points) 168 */ 169 if (tq_avg > max_tq) { 170 if (curr_gw) 171 batadv_gw_node_free_ref(curr_gw); 172 curr_gw = gw_node; 173 atomic_inc(&curr_gw->refcount); 174 } 175 break; 176 } 177 178 if (tq_avg > max_tq) 179 max_tq = tq_avg; 180 181 if (tmp_gw_factor > max_gw_factor) 182 max_gw_factor = tmp_gw_factor; 183 184 batadv_gw_node_free_ref(gw_node); 185 186 next: 187 batadv_neigh_node_free_ref(router); 188 } 189 rcu_read_unlock(); 190 191 return curr_gw; 192 } 193 194 void batadv_gw_election(struct batadv_priv *bat_priv) 195 { 196 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL; 197 struct batadv_neigh_node *router = NULL; 198 char gw_addr[18] = { '\0' }; 199 200 /* The batman daemon checks here if we already passed a full originator 201 * cycle in order to make sure we don't choose the first gateway we 202 * hear about. This check is based on the daemon's uptime which we 203 * don't have. 204 */ 205 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT) 206 goto out; 207 208 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 209 210 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw) 211 goto out; 212 213 next_gw = batadv_gw_get_best_gw_node(bat_priv); 214 215 if (curr_gw == next_gw) 216 goto out; 217 218 if (next_gw) { 219 sprintf(gw_addr, "%pM", next_gw->orig_node->orig); 220 221 router = batadv_orig_node_get_router(next_gw->orig_node); 222 if (!router) { 223 batadv_gw_deselect(bat_priv); 224 goto out; 225 } 226 } 227 228 if ((curr_gw) && (!next_gw)) { 229 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 230 "Removing selected gateway - no gateway in range\n"); 231 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, 232 NULL); 233 } else if ((!curr_gw) && (next_gw)) { 234 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 235 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n", 236 next_gw->orig_node->orig, 237 next_gw->orig_node->gw_flags, router->tq_avg); 238 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD, 239 gw_addr); 240 } else { 241 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 242 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n", 243 next_gw->orig_node->orig, 244 next_gw->orig_node->gw_flags, router->tq_avg); 245 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE, 246 gw_addr); 247 } 248 249 batadv_gw_select(bat_priv, next_gw); 250 251 out: 252 if (curr_gw) 253 batadv_gw_node_free_ref(curr_gw); 254 if (next_gw) 255 batadv_gw_node_free_ref(next_gw); 256 if (router) 257 batadv_neigh_node_free_ref(router); 258 } 259 260 void batadv_gw_check_election(struct batadv_priv *bat_priv, 261 struct batadv_orig_node *orig_node) 262 { 263 struct batadv_orig_node *curr_gw_orig; 264 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL; 265 uint8_t gw_tq_avg, orig_tq_avg; 266 267 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv); 268 if (!curr_gw_orig) 269 goto deselect; 270 271 router_gw = batadv_orig_node_get_router(curr_gw_orig); 272 if (!router_gw) 273 goto deselect; 274 275 /* this node already is the gateway */ 276 if (curr_gw_orig == orig_node) 277 goto out; 278 279 router_orig = batadv_orig_node_get_router(orig_node); 280 if (!router_orig) 281 goto out; 282 283 gw_tq_avg = router_gw->tq_avg; 284 orig_tq_avg = router_orig->tq_avg; 285 286 /* the TQ value has to be better */ 287 if (orig_tq_avg < gw_tq_avg) 288 goto out; 289 290 /* if the routing class is greater than 3 the value tells us how much 291 * greater the TQ value of the new gateway must be 292 */ 293 if ((atomic_read(&bat_priv->gw_sel_class) > 3) && 294 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class))) 295 goto out; 296 297 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 298 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n", 299 gw_tq_avg, orig_tq_avg); 300 301 deselect: 302 batadv_gw_deselect(bat_priv); 303 out: 304 if (curr_gw_orig) 305 batadv_orig_node_free_ref(curr_gw_orig); 306 if (router_gw) 307 batadv_neigh_node_free_ref(router_gw); 308 if (router_orig) 309 batadv_neigh_node_free_ref(router_orig); 310 311 return; 312 } 313 314 static void batadv_gw_node_add(struct batadv_priv *bat_priv, 315 struct batadv_orig_node *orig_node, 316 uint8_t new_gwflags) 317 { 318 struct batadv_gw_node *gw_node; 319 int down, up; 320 321 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC); 322 if (!gw_node) 323 return; 324 325 INIT_HLIST_NODE(&gw_node->list); 326 gw_node->orig_node = orig_node; 327 atomic_set(&gw_node->refcount, 1); 328 329 spin_lock_bh(&bat_priv->gw.list_lock); 330 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list); 331 spin_unlock_bh(&bat_priv->gw.list_lock); 332 333 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up); 334 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 335 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n", 336 orig_node->orig, new_gwflags, 337 (down > 2048 ? down / 1024 : down), 338 (down > 2048 ? "MBit" : "KBit"), 339 (up > 2048 ? up / 1024 : up), 340 (up > 2048 ? "MBit" : "KBit")); 341 } 342 343 void batadv_gw_node_update(struct batadv_priv *bat_priv, 344 struct batadv_orig_node *orig_node, 345 uint8_t new_gwflags) 346 { 347 struct hlist_node *node; 348 struct batadv_gw_node *gw_node, *curr_gw; 349 350 /* Note: We don't need a NULL check here, since curr_gw never gets 351 * dereferenced. If curr_gw is NULL we also should not exit as we may 352 * have this gateway in our list (duplication check!) even though we 353 * have no currently selected gateway. 354 */ 355 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 356 357 rcu_read_lock(); 358 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) { 359 if (gw_node->orig_node != orig_node) 360 continue; 361 362 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 363 "Gateway class of originator %pM changed from %i to %i\n", 364 orig_node->orig, gw_node->orig_node->gw_flags, 365 new_gwflags); 366 367 gw_node->deleted = 0; 368 369 if (new_gwflags == BATADV_NO_FLAGS) { 370 gw_node->deleted = jiffies; 371 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 372 "Gateway %pM removed from gateway list\n", 373 orig_node->orig); 374 375 if (gw_node == curr_gw) 376 goto deselect; 377 } 378 379 goto unlock; 380 } 381 382 if (new_gwflags == BATADV_NO_FLAGS) 383 goto unlock; 384 385 batadv_gw_node_add(bat_priv, orig_node, new_gwflags); 386 goto unlock; 387 388 deselect: 389 batadv_gw_deselect(bat_priv); 390 unlock: 391 rcu_read_unlock(); 392 393 if (curr_gw) 394 batadv_gw_node_free_ref(curr_gw); 395 } 396 397 void batadv_gw_node_delete(struct batadv_priv *bat_priv, 398 struct batadv_orig_node *orig_node) 399 { 400 batadv_gw_node_update(bat_priv, orig_node, 0); 401 } 402 403 void batadv_gw_node_purge(struct batadv_priv *bat_priv) 404 { 405 struct batadv_gw_node *gw_node, *curr_gw; 406 struct hlist_node *node, *node_tmp; 407 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT); 408 int do_deselect = 0; 409 410 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 411 412 spin_lock_bh(&bat_priv->gw.list_lock); 413 414 hlist_for_each_entry_safe(gw_node, node, node_tmp, 415 &bat_priv->gw.list, list) { 416 if (((!gw_node->deleted) || 417 (time_before(jiffies, gw_node->deleted + timeout))) && 418 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE) 419 continue; 420 421 if (curr_gw == gw_node) 422 do_deselect = 1; 423 424 hlist_del_rcu(&gw_node->list); 425 batadv_gw_node_free_ref(gw_node); 426 } 427 428 spin_unlock_bh(&bat_priv->gw.list_lock); 429 430 /* gw_deselect() needs to acquire the gw_list_lock */ 431 if (do_deselect) 432 batadv_gw_deselect(bat_priv); 433 434 if (curr_gw) 435 batadv_gw_node_free_ref(curr_gw); 436 } 437 438 /* fails if orig_node has no router */ 439 static int batadv_write_buffer_text(struct batadv_priv *bat_priv, 440 struct seq_file *seq, 441 const struct batadv_gw_node *gw_node) 442 { 443 struct batadv_gw_node *curr_gw; 444 struct batadv_neigh_node *router; 445 int down, up, ret = -1; 446 447 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up); 448 449 router = batadv_orig_node_get_router(gw_node->orig_node); 450 if (!router) 451 goto out; 452 453 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 454 455 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n", 456 (curr_gw == gw_node ? "=>" : " "), 457 gw_node->orig_node->orig, 458 router->tq_avg, router->addr, 459 router->if_incoming->net_dev->name, 460 gw_node->orig_node->gw_flags, 461 (down > 2048 ? down / 1024 : down), 462 (down > 2048 ? "MBit" : "KBit"), 463 (up > 2048 ? up / 1024 : up), 464 (up > 2048 ? "MBit" : "KBit")); 465 466 batadv_neigh_node_free_ref(router); 467 if (curr_gw) 468 batadv_gw_node_free_ref(curr_gw); 469 out: 470 return ret; 471 } 472 473 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset) 474 { 475 struct net_device *net_dev = (struct net_device *)seq->private; 476 struct batadv_priv *bat_priv = netdev_priv(net_dev); 477 struct batadv_hard_iface *primary_if; 478 struct batadv_gw_node *gw_node; 479 struct hlist_node *node; 480 int gw_count = 0, ret = 0; 481 482 primary_if = batadv_primary_if_get_selected(bat_priv); 483 if (!primary_if) { 484 ret = seq_printf(seq, 485 "BATMAN mesh %s disabled - please specify interfaces to enable it\n", 486 net_dev->name); 487 goto out; 488 } 489 490 if (primary_if->if_status != BATADV_IF_ACTIVE) { 491 ret = seq_printf(seq, 492 "BATMAN mesh %s disabled - primary interface not active\n", 493 net_dev->name); 494 goto out; 495 } 496 497 seq_printf(seq, 498 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n", 499 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF", 500 BATADV_SOURCE_VERSION, primary_if->net_dev->name, 501 primary_if->net_dev->dev_addr, net_dev->name); 502 503 rcu_read_lock(); 504 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) { 505 if (gw_node->deleted) 506 continue; 507 508 /* fails if orig_node has no router */ 509 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0) 510 continue; 511 512 gw_count++; 513 } 514 rcu_read_unlock(); 515 516 if (gw_count == 0) 517 seq_printf(seq, "No gateways in range ...\n"); 518 519 out: 520 if (primary_if) 521 batadv_hardif_free_ref(primary_if); 522 return ret; 523 } 524 525 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len) 526 { 527 int ret = false; 528 unsigned char *p; 529 int pkt_len; 530 531 if (skb_linearize(skb) < 0) 532 goto out; 533 534 pkt_len = skb_headlen(skb); 535 536 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1) 537 goto out; 538 539 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET; 540 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1; 541 542 /* Access the dhcp option lists. Each entry is made up by: 543 * - octet 1: option type 544 * - octet 2: option data len (only if type != 255 and 0) 545 * - octet 3: option data 546 */ 547 while (*p != 255 && !ret) { 548 /* p now points to the first octet: option type */ 549 if (*p == 53) { 550 /* type 53 is the message type option. 551 * Jump the len octet and go to the data octet 552 */ 553 if (pkt_len < 2) 554 goto out; 555 p += 2; 556 557 /* check if the message type is what we need */ 558 if (*p == BATADV_DHCP_REQUEST) 559 ret = true; 560 break; 561 } else if (*p == 0) { 562 /* option type 0 (padding), just go forward */ 563 if (pkt_len < 1) 564 goto out; 565 pkt_len--; 566 p++; 567 } else { 568 /* This is any other option. So we get the length... */ 569 if (pkt_len < 1) 570 goto out; 571 pkt_len--; 572 p++; 573 574 /* ...and then we jump over the data */ 575 if (pkt_len < 1 + (*p)) 576 goto out; 577 pkt_len -= 1 + (*p); 578 p += 1 + (*p); 579 } 580 } 581 out: 582 return ret; 583 } 584 585 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) 586 { 587 struct ethhdr *ethhdr; 588 struct iphdr *iphdr; 589 struct ipv6hdr *ipv6hdr; 590 struct udphdr *udphdr; 591 592 /* check for ethernet header */ 593 if (!pskb_may_pull(skb, *header_len + ETH_HLEN)) 594 return false; 595 ethhdr = (struct ethhdr *)skb->data; 596 *header_len += ETH_HLEN; 597 598 /* check for initial vlan header */ 599 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { 600 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN)) 601 return false; 602 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN); 603 *header_len += VLAN_HLEN; 604 } 605 606 /* check for ip header */ 607 switch (ntohs(ethhdr->h_proto)) { 608 case ETH_P_IP: 609 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr))) 610 return false; 611 iphdr = (struct iphdr *)(skb->data + *header_len); 612 *header_len += iphdr->ihl * 4; 613 614 /* check for udp header */ 615 if (iphdr->protocol != IPPROTO_UDP) 616 return false; 617 618 break; 619 case ETH_P_IPV6: 620 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr))) 621 return false; 622 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len); 623 *header_len += sizeof(*ipv6hdr); 624 625 /* check for udp header */ 626 if (ipv6hdr->nexthdr != IPPROTO_UDP) 627 return false; 628 629 break; 630 default: 631 return false; 632 } 633 634 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr))) 635 return false; 636 udphdr = (struct udphdr *)(skb->data + *header_len); 637 *header_len += sizeof(*udphdr); 638 639 /* check for bootp port */ 640 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) && 641 (ntohs(udphdr->dest) != 67)) 642 return false; 643 644 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) && 645 (ntohs(udphdr->dest) != 547)) 646 return false; 647 648 return true; 649 } 650 651 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, 652 struct sk_buff *skb, struct ethhdr *ethhdr) 653 { 654 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL; 655 struct batadv_orig_node *orig_dst_node = NULL; 656 struct batadv_gw_node *curr_gw = NULL; 657 bool ret, out_of_range = false; 658 unsigned int header_len = 0; 659 uint8_t curr_tq_avg; 660 661 ret = batadv_gw_is_dhcp_target(skb, &header_len); 662 if (!ret) 663 goto out; 664 665 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source, 666 ethhdr->h_dest); 667 if (!orig_dst_node) 668 goto out; 669 670 if (!orig_dst_node->gw_flags) 671 goto out; 672 673 ret = batadv_is_type_dhcprequest(skb, header_len); 674 if (!ret) 675 goto out; 676 677 switch (atomic_read(&bat_priv->gw_mode)) { 678 case BATADV_GW_MODE_SERVER: 679 /* If we are a GW then we are our best GW. We can artificially 680 * set the tq towards ourself as the maximum value 681 */ 682 curr_tq_avg = BATADV_TQ_MAX_VALUE; 683 break; 684 case BATADV_GW_MODE_CLIENT: 685 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 686 if (!curr_gw) 687 goto out; 688 689 /* packet is going to our gateway */ 690 if (curr_gw->orig_node == orig_dst_node) 691 goto out; 692 693 /* If the dhcp packet has been sent to a different gw, 694 * we have to evaluate whether the old gw is still 695 * reliable enough 696 */ 697 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node, 698 NULL); 699 if (!neigh_curr) 700 goto out; 701 702 curr_tq_avg = neigh_curr->tq_avg; 703 break; 704 case BATADV_GW_MODE_OFF: 705 default: 706 goto out; 707 } 708 709 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL); 710 if (!neigh_old) 711 goto out; 712 713 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD) 714 out_of_range = true; 715 716 out: 717 if (orig_dst_node) 718 batadv_orig_node_free_ref(orig_dst_node); 719 if (curr_gw) 720 batadv_gw_node_free_ref(curr_gw); 721 if (neigh_old) 722 batadv_neigh_node_free_ref(neigh_old); 723 if (neigh_curr) 724 batadv_neigh_node_free_ref(neigh_curr); 725 return out_of_range; 726 } 727