1 /* Copyright (C) 2013-2016 B.A.T.M.A.N. contributors: 2 * 3 * Antonio Quartulli 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 "bat_v_ogm.h" 19 #include "main.h" 20 21 #include <linux/atomic.h> 22 #include <linux/byteorder/generic.h> 23 #include <linux/errno.h> 24 #include <linux/etherdevice.h> 25 #include <linux/fs.h> 26 #include <linux/if_ether.h> 27 #include <linux/jiffies.h> 28 #include <linux/kernel.h> 29 #include <linux/list.h> 30 #include <linux/netdevice.h> 31 #include <linux/random.h> 32 #include <linux/rculist.h> 33 #include <linux/rcupdate.h> 34 #include <linux/skbuff.h> 35 #include <linux/slab.h> 36 #include <linux/stddef.h> 37 #include <linux/string.h> 38 #include <linux/types.h> 39 #include <linux/workqueue.h> 40 41 #include "hard-interface.h" 42 #include "hash.h" 43 #include "originator.h" 44 #include "packet.h" 45 #include "routing.h" 46 #include "send.h" 47 #include "translation-table.h" 48 49 /** 50 * batadv_v_ogm_orig_get - retrieve and possibly create an originator node 51 * @bat_priv: the bat priv with all the soft interface information 52 * @addr: the address of the originator 53 * 54 * Return: the orig_node corresponding to the specified address. If such object 55 * does not exist it is allocated here. In case of allocation failure returns 56 * NULL. 57 */ 58 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, 59 const u8 *addr) 60 { 61 struct batadv_orig_node *orig_node; 62 int hash_added; 63 64 orig_node = batadv_orig_hash_find(bat_priv, addr); 65 if (orig_node) 66 return orig_node; 67 68 orig_node = batadv_orig_node_new(bat_priv, addr); 69 if (!orig_node) 70 return NULL; 71 72 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, 73 batadv_choose_orig, orig_node, 74 &orig_node->hash_entry); 75 if (hash_added != 0) { 76 /* orig_node->refcounter is initialised to 2 by 77 * batadv_orig_node_new() 78 */ 79 batadv_orig_node_put(orig_node); 80 batadv_orig_node_put(orig_node); 81 orig_node = NULL; 82 } 83 84 return orig_node; 85 } 86 87 /** 88 * batadv_v_ogm_start_timer - restart the OGM sending timer 89 * @bat_priv: the bat priv with all the soft interface information 90 */ 91 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) 92 { 93 unsigned long msecs; 94 /* this function may be invoked in different contexts (ogm rescheduling 95 * or hard_iface activation), but the work timer should not be reset 96 */ 97 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq)) 98 return; 99 100 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; 101 msecs += prandom_u32() % (2 * BATADV_JITTER); 102 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, 103 msecs_to_jiffies(msecs)); 104 } 105 106 /** 107 * batadv_v_ogm_send_to_if - send a batman ogm using a given interface 108 * @skb: the OGM to send 109 * @hard_iface: the interface to use to send the OGM 110 */ 111 static void batadv_v_ogm_send_to_if(struct sk_buff *skb, 112 struct batadv_hard_iface *hard_iface) 113 { 114 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 115 116 if (hard_iface->if_status != BATADV_IF_ACTIVE) 117 return; 118 119 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX); 120 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES, 121 skb->len + ETH_HLEN); 122 123 batadv_send_broadcast_skb(skb, hard_iface); 124 } 125 126 /** 127 * batadv_v_ogm_send - periodic worker broadcasting the own OGM 128 * @work: work queue item 129 */ 130 static void batadv_v_ogm_send(struct work_struct *work) 131 { 132 struct batadv_hard_iface *hard_iface; 133 struct batadv_priv_bat_v *bat_v; 134 struct batadv_priv *bat_priv; 135 struct batadv_ogm2_packet *ogm_packet; 136 struct sk_buff *skb, *skb_tmp; 137 unsigned char *ogm_buff, *pkt_buff; 138 int ogm_buff_len; 139 u16 tvlv_len = 0; 140 141 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work); 142 bat_priv = container_of(bat_v, struct batadv_priv, bat_v); 143 144 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) 145 goto out; 146 147 ogm_buff = bat_priv->bat_v.ogm_buff; 148 ogm_buff_len = bat_priv->bat_v.ogm_buff_len; 149 /* tt changes have to be committed before the tvlv data is 150 * appended as it may alter the tt tvlv container 151 */ 152 batadv_tt_local_commit_changes(bat_priv); 153 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, 154 &ogm_buff_len, 155 BATADV_OGM2_HLEN); 156 157 bat_priv->bat_v.ogm_buff = ogm_buff; 158 bat_priv->bat_v.ogm_buff_len = ogm_buff_len; 159 160 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); 161 if (!skb) 162 goto reschedule; 163 164 skb_reserve(skb, ETH_HLEN); 165 pkt_buff = skb_put(skb, ogm_buff_len); 166 memcpy(pkt_buff, ogm_buff, ogm_buff_len); 167 168 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 169 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); 170 atomic_inc(&bat_priv->bat_v.ogm_seqno); 171 ogm_packet->tvlv_len = htons(tvlv_len); 172 173 /* broadcast on every interface */ 174 rcu_read_lock(); 175 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 176 if (hard_iface->soft_iface != bat_priv->soft_iface) 177 continue; 178 179 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 180 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n", 181 ogm_packet->orig, ntohl(ogm_packet->seqno), 182 ntohl(ogm_packet->throughput), ogm_packet->ttl, 183 hard_iface->net_dev->name, 184 hard_iface->net_dev->dev_addr); 185 186 /* this skb gets consumed by batadv_v_ogm_send_to_if() */ 187 skb_tmp = skb_clone(skb, GFP_ATOMIC); 188 if (!skb_tmp) 189 break; 190 191 batadv_v_ogm_send_to_if(skb_tmp, hard_iface); 192 } 193 rcu_read_unlock(); 194 195 consume_skb(skb); 196 197 reschedule: 198 batadv_v_ogm_start_timer(bat_priv); 199 out: 200 return; 201 } 202 203 /** 204 * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V 205 * @hard_iface: the interface to prepare 206 * 207 * Takes care of scheduling own OGM sending routine for this interface. 208 * 209 * Return: 0 on success or a negative error code otherwise 210 */ 211 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface) 212 { 213 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 214 215 batadv_v_ogm_start_timer(bat_priv); 216 217 return 0; 218 } 219 220 /** 221 * batadv_v_ogm_primary_iface_set - set a new primary interface 222 * @primary_iface: the new primary interface 223 */ 224 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) 225 { 226 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface); 227 struct batadv_ogm2_packet *ogm_packet; 228 229 if (!bat_priv->bat_v.ogm_buff) 230 return; 231 232 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff; 233 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr); 234 } 235 236 /** 237 * batadv_v_ogm_orig_update - update the originator status based on the received 238 * OGM 239 * @bat_priv: the bat priv with all the soft interface information 240 * @orig_node: the originator to update 241 * @neigh_node: the neighbour the OGM has been received from (to update) 242 * @ogm2: the received OGM 243 * @if_outgoing: the interface where this OGM is going to be forwarded through 244 */ 245 static void 246 batadv_v_ogm_orig_update(struct batadv_priv *bat_priv, 247 struct batadv_orig_node *orig_node, 248 struct batadv_neigh_node *neigh_node, 249 const struct batadv_ogm2_packet *ogm2, 250 struct batadv_hard_iface *if_outgoing) 251 { 252 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; 253 struct batadv_neigh_node *router = NULL; 254 s32 neigh_seq_diff; 255 u32 neigh_last_seqno; 256 u32 router_last_seqno; 257 u32 router_throughput, neigh_throughput; 258 259 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 260 "Searching and updating originator entry of received packet\n"); 261 262 /* if this neighbor already is our next hop there is nothing 263 * to change 264 */ 265 router = batadv_orig_router_get(orig_node, if_outgoing); 266 if (router == neigh_node) 267 goto out; 268 269 /* don't consider neighbours with worse throughput. 270 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than 271 * the last received seqno from our best next hop. 272 */ 273 if (router) { 274 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); 275 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 276 277 /* if these are not allocated, something is wrong. */ 278 if (!router_ifinfo || !neigh_ifinfo) 279 goto out; 280 281 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; 282 router_last_seqno = router_ifinfo->bat_v.last_seqno; 283 neigh_seq_diff = neigh_last_seqno - router_last_seqno; 284 router_throughput = router_ifinfo->bat_v.throughput; 285 neigh_throughput = neigh_ifinfo->bat_v.throughput; 286 287 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) && 288 (router_throughput >= neigh_throughput)) 289 goto out; 290 } 291 292 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); 293 294 out: 295 if (router_ifinfo) 296 batadv_neigh_ifinfo_put(router_ifinfo); 297 if (neigh_ifinfo) 298 batadv_neigh_ifinfo_put(neigh_ifinfo); 299 if (router) 300 batadv_neigh_node_put(router); 301 } 302 303 /** 304 * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded 305 * with B.A.T.M.A.N. V OGMs 306 * @bat_priv: the bat priv with all the soft interface information 307 * @if_incoming: the interface where the OGM has been received 308 * @if_outgoing: the interface where the OGM has to be forwarded to 309 * @throughput: the current throughput 310 * 311 * Apply a penalty on the current throughput metric value based on the 312 * characteristic of the interface where the OGM has been received. The return 313 * value is computed as follows: 314 * - throughput * 50% if the incoming and outgoing interface are the 315 * same WiFi interface and the throughput is above 316 * 1MBit/s 317 * - throughput if the outgoing interface is the default 318 * interface (i.e. this OGM is processed for the 319 * internal table and not forwarded) 320 * - throughput * hop penalty otherwise 321 * 322 * Return: the penalised throughput metric. 323 */ 324 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, 325 struct batadv_hard_iface *if_incoming, 326 struct batadv_hard_iface *if_outgoing, 327 u32 throughput) 328 { 329 int hop_penalty = atomic_read(&bat_priv->hop_penalty); 330 int hop_penalty_max = BATADV_TQ_MAX_VALUE; 331 332 /* Don't apply hop penalty in default originator table. */ 333 if (if_outgoing == BATADV_IF_DEFAULT) 334 return throughput; 335 336 /* Forwarding on the same WiFi interface cuts the throughput in half 337 * due to the store & forward characteristics of WIFI. 338 * Very low throughput values are the exception. 339 */ 340 if ((throughput > 10) && 341 (if_incoming == if_outgoing) && 342 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX)) 343 return throughput / 2; 344 345 /* hop penalty of 255 equals 100% */ 346 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; 347 } 348 349 /** 350 * batadv_v_ogm_forward - forward an OGM to the given outgoing interface 351 * @bat_priv: the bat priv with all the soft interface information 352 * @ogm_received: previously received OGM to be forwarded 353 * @throughput: throughput to announce, may vary per outgoing interface 354 * @if_incoming: the interface on which this OGM was received on 355 * @if_outgoing: the interface to which the OGM has to be forwarded to 356 * 357 * Forward an OGM to an interface after having altered the throughput metric and 358 * the TTL value contained in it. The original OGM isn't modified. 359 */ 360 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, 361 const struct batadv_ogm2_packet *ogm_received, 362 u32 throughput, 363 struct batadv_hard_iface *if_incoming, 364 struct batadv_hard_iface *if_outgoing) 365 { 366 struct batadv_ogm2_packet *ogm_forward; 367 unsigned char *skb_buff; 368 struct sk_buff *skb; 369 size_t packet_len; 370 u16 tvlv_len; 371 372 if (ogm_received->ttl <= 1) { 373 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); 374 return; 375 } 376 377 tvlv_len = ntohs(ogm_received->tvlv_len); 378 379 packet_len = BATADV_OGM2_HLEN + tvlv_len; 380 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, 381 ETH_HLEN + packet_len); 382 if (!skb) 383 return; 384 385 skb_reserve(skb, ETH_HLEN); 386 skb_buff = skb_put(skb, packet_len); 387 memcpy(skb_buff, ogm_received, packet_len); 388 389 /* apply forward penalty */ 390 ogm_forward = (struct batadv_ogm2_packet *)skb_buff; 391 ogm_forward->throughput = htonl(throughput); 392 ogm_forward->ttl--; 393 394 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 395 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", 396 if_outgoing->net_dev->name, throughput, ogm_forward->ttl, 397 if_incoming->net_dev->name); 398 399 batadv_v_ogm_send_to_if(skb, if_outgoing); 400 } 401 402 /** 403 * batadv_v_ogm_metric_update - update route metric based on OGM 404 * @bat_priv: the bat priv with all the soft interface information 405 * @ogm2: OGM2 structure 406 * @orig_node: Originator structure for which the OGM has been received 407 * @neigh_node: the neigh_node through with the OGM has been received 408 * @if_incoming: the interface where this packet was received 409 * @if_outgoing: the interface for which the packet should be considered 410 * 411 * Return: 412 * 1 if the OGM is new, 413 * 0 if it is not new but valid, 414 * <0 on error (e.g. old OGM) 415 */ 416 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, 417 const struct batadv_ogm2_packet *ogm2, 418 struct batadv_orig_node *orig_node, 419 struct batadv_neigh_node *neigh_node, 420 struct batadv_hard_iface *if_incoming, 421 struct batadv_hard_iface *if_outgoing) 422 { 423 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 424 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 425 bool protection_started = false; 426 int ret = -EINVAL; 427 u32 path_throughput; 428 s32 seq_diff; 429 430 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 431 if (!orig_ifinfo) 432 goto out; 433 434 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; 435 436 if (!hlist_empty(&orig_node->neigh_list) && 437 batadv_window_protected(bat_priv, seq_diff, 438 BATADV_OGM_MAX_AGE, 439 &orig_ifinfo->batman_seqno_reset, 440 &protection_started)) { 441 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 442 "Drop packet: packet within window protection time from %pM\n", 443 ogm2->orig); 444 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 445 "Last reset: %ld, %ld\n", 446 orig_ifinfo->batman_seqno_reset, jiffies); 447 goto out; 448 } 449 450 /* drop packets with old seqnos, however accept the first packet after 451 * a host has been rebooted. 452 */ 453 if ((seq_diff < 0) && !protection_started) 454 goto out; 455 456 neigh_node->last_seen = jiffies; 457 458 orig_node->last_seen = jiffies; 459 460 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); 461 orig_ifinfo->last_ttl = ogm2->ttl; 462 463 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); 464 if (!neigh_ifinfo) 465 goto out; 466 467 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, 468 if_outgoing, 469 ntohl(ogm2->throughput)); 470 neigh_ifinfo->bat_v.throughput = path_throughput; 471 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); 472 neigh_ifinfo->last_ttl = ogm2->ttl; 473 474 if (seq_diff > 0 || protection_started) 475 ret = 1; 476 else 477 ret = 0; 478 out: 479 if (orig_ifinfo) 480 batadv_orig_ifinfo_put(orig_ifinfo); 481 if (neigh_ifinfo) 482 batadv_neigh_ifinfo_put(neigh_ifinfo); 483 484 return ret; 485 } 486 487 /** 488 * batadv_v_ogm_route_update - update routes based on OGM 489 * @bat_priv: the bat priv with all the soft interface information 490 * @ethhdr: the Ethernet header of the OGM2 491 * @ogm2: OGM2 structure 492 * @orig_node: Originator structure for which the OGM has been received 493 * @neigh_node: the neigh_node through with the OGM has been received 494 * @if_incoming: the interface where this packet was received 495 * @if_outgoing: the interface for which the packet should be considered 496 */ 497 static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv, 498 const struct ethhdr *ethhdr, 499 const struct batadv_ogm2_packet *ogm2, 500 struct batadv_orig_node *orig_node, 501 struct batadv_neigh_node *neigh_node, 502 struct batadv_hard_iface *if_incoming, 503 struct batadv_hard_iface *if_outgoing) 504 { 505 struct batadv_neigh_node *router = NULL; 506 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 507 struct batadv_orig_node *orig_neigh_node = NULL; 508 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 509 struct batadv_neigh_node *orig_neigh_router = NULL; 510 511 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 512 if (!neigh_ifinfo) 513 goto out; 514 515 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); 516 if (!orig_neigh_node) 517 goto out; 518 519 orig_neigh_router = batadv_orig_router_get(orig_neigh_node, 520 if_outgoing); 521 522 /* drop packet if sender is not a direct neighbor and if we 523 * don't route towards it 524 */ 525 router = batadv_orig_router_get(orig_node, if_outgoing); 526 if (router && router->orig_node != orig_node && !orig_neigh_router) { 527 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 528 "Drop packet: OGM via unknown neighbor!\n"); 529 goto out; 530 } 531 532 if (router) 533 batadv_neigh_node_put(router); 534 535 /* Update routes, and check if the OGM is from the best next hop */ 536 batadv_v_ogm_orig_update(bat_priv, orig_node, neigh_node, ogm2, 537 if_outgoing); 538 539 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 540 if (!orig_ifinfo) 541 goto out; 542 543 /* don't forward the same seqno twice on one interface */ 544 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm2->seqno)) 545 goto out; 546 547 /* acquire possibly updated router */ 548 router = batadv_orig_router_get(orig_node, if_outgoing); 549 550 /* strict rule: forward packets coming from the best next hop only */ 551 if (neigh_node != router) 552 goto out; 553 554 /* only forward for specific interface, not for the default one. */ 555 if (if_outgoing != BATADV_IF_DEFAULT) { 556 orig_ifinfo->last_seqno_forwarded = ntohl(ogm2->seqno); 557 batadv_v_ogm_forward(bat_priv, ogm2, 558 neigh_ifinfo->bat_v.throughput, 559 if_incoming, if_outgoing); 560 } 561 562 out: 563 if (orig_ifinfo) 564 batadv_orig_ifinfo_put(orig_ifinfo); 565 if (router) 566 batadv_neigh_node_put(router); 567 if (orig_neigh_router) 568 batadv_neigh_node_put(orig_neigh_router); 569 if (orig_neigh_node) 570 batadv_orig_node_put(orig_neigh_node); 571 if (neigh_ifinfo) 572 batadv_neigh_ifinfo_put(neigh_ifinfo); 573 } 574 575 /** 576 * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if 577 * @bat_priv: the bat priv with all the soft interface information 578 * @ethhdr: the Ethernet header of the OGM2 579 * @ogm2: OGM2 structure 580 * @orig_node: Originator structure for which the OGM has been received 581 * @neigh_node: the neigh_node through with the OGM has been received 582 * @if_incoming: the interface where this packet was received 583 * @if_outgoing: the interface for which the packet should be considered 584 */ 585 static void 586 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, 587 const struct ethhdr *ethhdr, 588 const struct batadv_ogm2_packet *ogm2, 589 struct batadv_orig_node *orig_node, 590 struct batadv_neigh_node *neigh_node, 591 struct batadv_hard_iface *if_incoming, 592 struct batadv_hard_iface *if_outgoing) 593 { 594 int seqno_age; 595 596 /* first, update the metric with according sanity checks */ 597 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, 598 neigh_node, if_incoming, 599 if_outgoing); 600 601 /* outdated sequence numbers are to be discarded */ 602 if (seqno_age < 0) 603 return; 604 605 /* only unknown & newer OGMs contain TVLVs we are interested in */ 606 if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT)) 607 batadv_tvlv_containers_process(bat_priv, true, orig_node, 608 NULL, NULL, 609 (unsigned char *)(ogm2 + 1), 610 ntohs(ogm2->tvlv_len)); 611 612 /* if the metric update went through, update routes if needed */ 613 batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, 614 neigh_node, if_incoming, if_outgoing); 615 } 616 617 /** 618 * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated 619 * @buff_pos: current position in the skb 620 * @packet_len: total length of the skb 621 * @tvlv_len: tvlv length of the previously considered OGM 622 * 623 * Return: true if there is enough space for another OGM, false otherwise. 624 */ 625 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, 626 __be16 tvlv_len) 627 { 628 int next_buff_pos = 0; 629 630 next_buff_pos += buff_pos + BATADV_OGM2_HLEN; 631 next_buff_pos += ntohs(tvlv_len); 632 633 return (next_buff_pos <= packet_len) && 634 (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); 635 } 636 637 /** 638 * batadv_v_ogm_process - process an incoming batman v OGM 639 * @skb: the skb containing the OGM 640 * @ogm_offset: offset to the OGM which should be processed (for aggregates) 641 * @if_incoming: the interface where this packet was receved 642 */ 643 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, 644 struct batadv_hard_iface *if_incoming) 645 { 646 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 647 struct ethhdr *ethhdr; 648 struct batadv_orig_node *orig_node = NULL; 649 struct batadv_hardif_neigh_node *hardif_neigh = NULL; 650 struct batadv_neigh_node *neigh_node = NULL; 651 struct batadv_hard_iface *hard_iface; 652 struct batadv_ogm2_packet *ogm_packet; 653 u32 ogm_throughput, link_throughput, path_throughput; 654 655 ethhdr = eth_hdr(skb); 656 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset); 657 658 ogm_throughput = ntohl(ogm_packet->throughput); 659 660 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 661 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n", 662 ethhdr->h_source, if_incoming->net_dev->name, 663 if_incoming->net_dev->dev_addr, ogm_packet->orig, 664 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, 665 ogm_packet->version, ntohs(ogm_packet->tvlv_len)); 666 667 /* If the troughput metric is 0, immediately drop the packet. No need to 668 * create orig_node / neigh_node for an unusable route. 669 */ 670 if (ogm_throughput == 0) { 671 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 672 "Drop packet: originator packet with troughput metric of 0\n"); 673 return; 674 } 675 676 /* require ELP packets be to received from this neighbor first */ 677 hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source); 678 if (!hardif_neigh) { 679 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 680 "Drop packet: OGM via unknown neighbor!\n"); 681 goto out; 682 } 683 684 orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig); 685 if (!orig_node) 686 return; 687 688 neigh_node = batadv_neigh_node_new(orig_node, if_incoming, 689 ethhdr->h_source); 690 if (!neigh_node) 691 goto out; 692 693 /* Update the received throughput metric to match the link 694 * characteristic: 695 * - If this OGM traveled one hop so far (emitted by single hop 696 * neighbor) the path throughput metric equals the link throughput. 697 * - For OGMs traversing more than hop the path throughput metric is 698 * the smaller of the path throughput and the link throughput. 699 */ 700 link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput); 701 path_throughput = min_t(u32, link_throughput, ogm_throughput); 702 ogm_packet->throughput = htonl(path_throughput); 703 704 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node, 705 neigh_node, if_incoming, 706 BATADV_IF_DEFAULT); 707 708 rcu_read_lock(); 709 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 710 if (hard_iface->if_status != BATADV_IF_ACTIVE) 711 continue; 712 713 if (hard_iface->soft_iface != bat_priv->soft_iface) 714 continue; 715 716 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, 717 orig_node, neigh_node, 718 if_incoming, hard_iface); 719 } 720 rcu_read_unlock(); 721 out: 722 if (orig_node) 723 batadv_orig_node_put(orig_node); 724 if (neigh_node) 725 batadv_neigh_node_put(neigh_node); 726 if (hardif_neigh) 727 batadv_hardif_neigh_put(hardif_neigh); 728 } 729 730 /** 731 * batadv_v_ogm_packet_recv - OGM2 receiving handler 732 * @skb: the received OGM 733 * @if_incoming: the interface where this OGM has been received 734 * 735 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP 736 * (without freeing the skb) on failure 737 */ 738 int batadv_v_ogm_packet_recv(struct sk_buff *skb, 739 struct batadv_hard_iface *if_incoming) 740 { 741 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 742 struct batadv_ogm2_packet *ogm_packet; 743 struct ethhdr *ethhdr = eth_hdr(skb); 744 int ogm_offset; 745 u8 *packet_pos; 746 int ret = NET_RX_DROP; 747 748 /* did we receive a OGM2 packet on an interface that does not have 749 * B.A.T.M.A.N. V enabled ? 750 */ 751 if (strcmp(bat_priv->bat_algo_ops->name, "BATMAN_V") != 0) 752 return NET_RX_DROP; 753 754 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) 755 return NET_RX_DROP; 756 757 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 758 return NET_RX_DROP; 759 760 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 761 762 if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) 763 return NET_RX_DROP; 764 765 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); 766 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, 767 skb->len + ETH_HLEN); 768 769 ogm_offset = 0; 770 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 771 772 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), 773 ogm_packet->tvlv_len)) { 774 batadv_v_ogm_process(skb, ogm_offset, if_incoming); 775 776 ogm_offset += BATADV_OGM2_HLEN; 777 ogm_offset += ntohs(ogm_packet->tvlv_len); 778 779 packet_pos = skb->data + ogm_offset; 780 ogm_packet = (struct batadv_ogm2_packet *)packet_pos; 781 } 782 783 ret = NET_RX_SUCCESS; 784 consume_skb(skb); 785 786 return ret; 787 } 788 789 /** 790 * batadv_v_ogm_init - initialise the OGM2 engine 791 * @bat_priv: the bat priv with all the soft interface information 792 * 793 * Return: 0 on success or a negative error code in case of failure 794 */ 795 int batadv_v_ogm_init(struct batadv_priv *bat_priv) 796 { 797 struct batadv_ogm2_packet *ogm_packet; 798 unsigned char *ogm_buff; 799 u32 random_seqno; 800 801 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN; 802 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC); 803 if (!ogm_buff) 804 return -ENOMEM; 805 806 bat_priv->bat_v.ogm_buff = ogm_buff; 807 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff; 808 ogm_packet->packet_type = BATADV_OGM2; 809 ogm_packet->version = BATADV_COMPAT_VERSION; 810 ogm_packet->ttl = BATADV_TTL; 811 ogm_packet->flags = BATADV_NO_FLAGS; 812 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE); 813 814 /* randomize initial seqno to avoid collision */ 815 get_random_bytes(&random_seqno, sizeof(random_seqno)); 816 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno); 817 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send); 818 819 return 0; 820 } 821 822 /** 823 * batadv_v_ogm_free - free OGM private resources 824 * @bat_priv: the bat priv with all the soft interface information 825 */ 826 void batadv_v_ogm_free(struct batadv_priv *bat_priv) 827 { 828 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq); 829 830 kfree(bat_priv->bat_v.ogm_buff); 831 bat_priv->bat_v.ogm_buff = NULL; 832 bat_priv->bat_v.ogm_buff_len = 0; 833 } 834