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/kref.h> 30 #include <linux/list.h> 31 #include <linux/netdevice.h> 32 #include <linux/random.h> 33 #include <linux/rculist.h> 34 #include <linux/rcupdate.h> 35 #include <linux/skbuff.h> 36 #include <linux/slab.h> 37 #include <linux/stddef.h> 38 #include <linux/string.h> 39 #include <linux/types.h> 40 #include <linux/workqueue.h> 41 42 #include "bat_algo.h" 43 #include "hard-interface.h" 44 #include "hash.h" 45 #include "log.h" 46 #include "originator.h" 47 #include "packet.h" 48 #include "routing.h" 49 #include "send.h" 50 #include "translation-table.h" 51 #include "tvlv.h" 52 53 /** 54 * batadv_v_ogm_orig_get - retrieve and possibly create an originator node 55 * @bat_priv: the bat priv with all the soft interface information 56 * @addr: the address of the originator 57 * 58 * Return: the orig_node corresponding to the specified address. If such object 59 * does not exist it is allocated here. In case of allocation failure returns 60 * NULL. 61 */ 62 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, 63 const u8 *addr) 64 { 65 struct batadv_orig_node *orig_node; 66 int hash_added; 67 68 orig_node = batadv_orig_hash_find(bat_priv, addr); 69 if (orig_node) 70 return orig_node; 71 72 orig_node = batadv_orig_node_new(bat_priv, addr); 73 if (!orig_node) 74 return NULL; 75 76 kref_get(&orig_node->refcount); 77 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, 78 batadv_choose_orig, orig_node, 79 &orig_node->hash_entry); 80 if (hash_added != 0) { 81 /* remove refcnt for newly created orig_node and hash entry */ 82 batadv_orig_node_put(orig_node); 83 batadv_orig_node_put(orig_node); 84 orig_node = NULL; 85 } 86 87 return orig_node; 88 } 89 90 /** 91 * batadv_v_ogm_start_timer - restart the OGM sending timer 92 * @bat_priv: the bat priv with all the soft interface information 93 */ 94 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) 95 { 96 unsigned long msecs; 97 /* this function may be invoked in different contexts (ogm rescheduling 98 * or hard_iface activation), but the work timer should not be reset 99 */ 100 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq)) 101 return; 102 103 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; 104 msecs += prandom_u32() % (2 * BATADV_JITTER); 105 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, 106 msecs_to_jiffies(msecs)); 107 } 108 109 /** 110 * batadv_v_ogm_send_to_if - send a batman ogm using a given interface 111 * @skb: the OGM to send 112 * @hard_iface: the interface to use to send the OGM 113 */ 114 static void batadv_v_ogm_send_to_if(struct sk_buff *skb, 115 struct batadv_hard_iface *hard_iface) 116 { 117 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 118 119 if (hard_iface->if_status != BATADV_IF_ACTIVE) 120 return; 121 122 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX); 123 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES, 124 skb->len + ETH_HLEN); 125 126 batadv_send_broadcast_skb(skb, hard_iface); 127 } 128 129 /** 130 * batadv_v_ogm_send - periodic worker broadcasting the own OGM 131 * @work: work queue item 132 */ 133 static void batadv_v_ogm_send(struct work_struct *work) 134 { 135 struct batadv_hard_iface *hard_iface; 136 struct batadv_priv_bat_v *bat_v; 137 struct batadv_priv *bat_priv; 138 struct batadv_ogm2_packet *ogm_packet; 139 struct sk_buff *skb, *skb_tmp; 140 unsigned char *ogm_buff, *pkt_buff; 141 int ogm_buff_len; 142 u16 tvlv_len = 0; 143 144 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work); 145 bat_priv = container_of(bat_v, struct batadv_priv, bat_v); 146 147 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) 148 goto out; 149 150 ogm_buff = bat_priv->bat_v.ogm_buff; 151 ogm_buff_len = bat_priv->bat_v.ogm_buff_len; 152 /* tt changes have to be committed before the tvlv data is 153 * appended as it may alter the tt tvlv container 154 */ 155 batadv_tt_local_commit_changes(bat_priv); 156 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, 157 &ogm_buff_len, 158 BATADV_OGM2_HLEN); 159 160 bat_priv->bat_v.ogm_buff = ogm_buff; 161 bat_priv->bat_v.ogm_buff_len = ogm_buff_len; 162 163 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); 164 if (!skb) 165 goto reschedule; 166 167 skb_reserve(skb, ETH_HLEN); 168 pkt_buff = skb_put(skb, ogm_buff_len); 169 memcpy(pkt_buff, ogm_buff, ogm_buff_len); 170 171 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 172 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); 173 atomic_inc(&bat_priv->bat_v.ogm_seqno); 174 ogm_packet->tvlv_len = htons(tvlv_len); 175 176 /* broadcast on every interface */ 177 rcu_read_lock(); 178 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 179 if (hard_iface->soft_iface != bat_priv->soft_iface) 180 continue; 181 182 if (!kref_get_unless_zero(&hard_iface->refcount)) 183 continue; 184 185 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 186 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n", 187 ogm_packet->orig, ntohl(ogm_packet->seqno), 188 ntohl(ogm_packet->throughput), ogm_packet->ttl, 189 hard_iface->net_dev->name, 190 hard_iface->net_dev->dev_addr); 191 192 /* this skb gets consumed by batadv_v_ogm_send_to_if() */ 193 skb_tmp = skb_clone(skb, GFP_ATOMIC); 194 if (!skb_tmp) { 195 batadv_hardif_put(hard_iface); 196 break; 197 } 198 199 batadv_v_ogm_send_to_if(skb_tmp, hard_iface); 200 batadv_hardif_put(hard_iface); 201 } 202 rcu_read_unlock(); 203 204 consume_skb(skb); 205 206 reschedule: 207 batadv_v_ogm_start_timer(bat_priv); 208 out: 209 return; 210 } 211 212 /** 213 * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V 214 * @hard_iface: the interface to prepare 215 * 216 * Takes care of scheduling own OGM sending routine for this interface. 217 * 218 * Return: 0 on success or a negative error code otherwise 219 */ 220 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface) 221 { 222 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 223 224 batadv_v_ogm_start_timer(bat_priv); 225 226 return 0; 227 } 228 229 /** 230 * batadv_v_ogm_primary_iface_set - set a new primary interface 231 * @primary_iface: the new primary interface 232 */ 233 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) 234 { 235 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface); 236 struct batadv_ogm2_packet *ogm_packet; 237 238 if (!bat_priv->bat_v.ogm_buff) 239 return; 240 241 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff; 242 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr); 243 } 244 245 /** 246 * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded 247 * with B.A.T.M.A.N. V OGMs 248 * @bat_priv: the bat priv with all the soft interface information 249 * @if_incoming: the interface where the OGM has been received 250 * @if_outgoing: the interface where the OGM has to be forwarded to 251 * @throughput: the current throughput 252 * 253 * Apply a penalty on the current throughput metric value based on the 254 * characteristic of the interface where the OGM has been received. The return 255 * value is computed as follows: 256 * - throughput * 50% if the incoming and outgoing interface are the 257 * same WiFi interface and the throughput is above 258 * 1MBit/s 259 * - throughput if the outgoing interface is the default 260 * interface (i.e. this OGM is processed for the 261 * internal table and not forwarded) 262 * - throughput * hop penalty otherwise 263 * 264 * Return: the penalised throughput metric. 265 */ 266 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, 267 struct batadv_hard_iface *if_incoming, 268 struct batadv_hard_iface *if_outgoing, 269 u32 throughput) 270 { 271 int hop_penalty = atomic_read(&bat_priv->hop_penalty); 272 int hop_penalty_max = BATADV_TQ_MAX_VALUE; 273 274 /* Don't apply hop penalty in default originator table. */ 275 if (if_outgoing == BATADV_IF_DEFAULT) 276 return throughput; 277 278 /* Forwarding on the same WiFi interface cuts the throughput in half 279 * due to the store & forward characteristics of WIFI. 280 * Very low throughput values are the exception. 281 */ 282 if ((throughput > 10) && 283 (if_incoming == if_outgoing) && 284 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX)) 285 return throughput / 2; 286 287 /* hop penalty of 255 equals 100% */ 288 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; 289 } 290 291 /** 292 * batadv_v_ogm_forward - check conditions and forward an OGM to the given 293 * outgoing interface 294 * @bat_priv: the bat priv with all the soft interface information 295 * @ogm_received: previously received OGM to be forwarded 296 * @orig_node: the originator which has been updated 297 * @neigh_node: the neigh_node through with the OGM has been received 298 * @if_incoming: the interface on which this OGM was received on 299 * @if_outgoing: the interface to which the OGM has to be forwarded to 300 * 301 * Forward an OGM to an interface after having altered the throughput metric and 302 * the TTL value contained in it. The original OGM isn't modified. 303 */ 304 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, 305 const struct batadv_ogm2_packet *ogm_received, 306 struct batadv_orig_node *orig_node, 307 struct batadv_neigh_node *neigh_node, 308 struct batadv_hard_iface *if_incoming, 309 struct batadv_hard_iface *if_outgoing) 310 { 311 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 312 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 313 struct batadv_neigh_node *router = NULL; 314 struct batadv_ogm2_packet *ogm_forward; 315 unsigned char *skb_buff; 316 struct sk_buff *skb; 317 size_t packet_len; 318 u16 tvlv_len; 319 320 /* only forward for specific interfaces, not for the default one. */ 321 if (if_outgoing == BATADV_IF_DEFAULT) 322 goto out; 323 324 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 325 if (!orig_ifinfo) 326 goto out; 327 328 /* acquire possibly updated router */ 329 router = batadv_orig_router_get(orig_node, if_outgoing); 330 331 /* strict rule: forward packets coming from the best next hop only */ 332 if (neigh_node != router) 333 goto out; 334 335 /* don't forward the same seqno twice on one interface */ 336 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno)) 337 goto out; 338 339 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno); 340 341 if (ogm_received->ttl <= 1) { 342 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); 343 goto out; 344 } 345 346 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 347 if (!neigh_ifinfo) 348 goto out; 349 350 tvlv_len = ntohs(ogm_received->tvlv_len); 351 352 packet_len = BATADV_OGM2_HLEN + tvlv_len; 353 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, 354 ETH_HLEN + packet_len); 355 if (!skb) 356 goto out; 357 358 skb_reserve(skb, ETH_HLEN); 359 skb_buff = skb_put(skb, packet_len); 360 memcpy(skb_buff, ogm_received, packet_len); 361 362 /* apply forward penalty */ 363 ogm_forward = (struct batadv_ogm2_packet *)skb_buff; 364 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput); 365 ogm_forward->ttl--; 366 367 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 368 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", 369 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), 370 ogm_forward->ttl, if_incoming->net_dev->name); 371 372 batadv_v_ogm_send_to_if(skb, if_outgoing); 373 374 out: 375 if (orig_ifinfo) 376 batadv_orig_ifinfo_put(orig_ifinfo); 377 if (router) 378 batadv_neigh_node_put(router); 379 if (neigh_ifinfo) 380 batadv_neigh_ifinfo_put(neigh_ifinfo); 381 } 382 383 /** 384 * batadv_v_ogm_metric_update - update route metric based on OGM 385 * @bat_priv: the bat priv with all the soft interface information 386 * @ogm2: OGM2 structure 387 * @orig_node: Originator structure for which the OGM has been received 388 * @neigh_node: the neigh_node through with the OGM has been received 389 * @if_incoming: the interface where this packet was received 390 * @if_outgoing: the interface for which the packet should be considered 391 * 392 * Return: 393 * 1 if the OGM is new, 394 * 0 if it is not new but valid, 395 * <0 on error (e.g. old OGM) 396 */ 397 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, 398 const struct batadv_ogm2_packet *ogm2, 399 struct batadv_orig_node *orig_node, 400 struct batadv_neigh_node *neigh_node, 401 struct batadv_hard_iface *if_incoming, 402 struct batadv_hard_iface *if_outgoing) 403 { 404 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 405 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 406 bool protection_started = false; 407 int ret = -EINVAL; 408 u32 path_throughput; 409 s32 seq_diff; 410 411 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 412 if (!orig_ifinfo) 413 goto out; 414 415 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; 416 417 if (!hlist_empty(&orig_node->neigh_list) && 418 batadv_window_protected(bat_priv, seq_diff, 419 BATADV_OGM_MAX_AGE, 420 &orig_ifinfo->batman_seqno_reset, 421 &protection_started)) { 422 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 423 "Drop packet: packet within window protection time from %pM\n", 424 ogm2->orig); 425 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 426 "Last reset: %ld, %ld\n", 427 orig_ifinfo->batman_seqno_reset, jiffies); 428 goto out; 429 } 430 431 /* drop packets with old seqnos, however accept the first packet after 432 * a host has been rebooted. 433 */ 434 if ((seq_diff < 0) && !protection_started) 435 goto out; 436 437 neigh_node->last_seen = jiffies; 438 439 orig_node->last_seen = jiffies; 440 441 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); 442 orig_ifinfo->last_ttl = ogm2->ttl; 443 444 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); 445 if (!neigh_ifinfo) 446 goto out; 447 448 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, 449 if_outgoing, 450 ntohl(ogm2->throughput)); 451 neigh_ifinfo->bat_v.throughput = path_throughput; 452 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); 453 neigh_ifinfo->last_ttl = ogm2->ttl; 454 455 if (seq_diff > 0 || protection_started) 456 ret = 1; 457 else 458 ret = 0; 459 out: 460 if (orig_ifinfo) 461 batadv_orig_ifinfo_put(orig_ifinfo); 462 if (neigh_ifinfo) 463 batadv_neigh_ifinfo_put(neigh_ifinfo); 464 465 return ret; 466 } 467 468 /** 469 * batadv_v_ogm_route_update - update routes based on OGM 470 * @bat_priv: the bat priv with all the soft interface information 471 * @ethhdr: the Ethernet header of the OGM2 472 * @ogm2: OGM2 structure 473 * @orig_node: Originator structure for which the OGM has been received 474 * @neigh_node: the neigh_node through with the OGM has been received 475 * @if_incoming: the interface where this packet was received 476 * @if_outgoing: the interface for which the packet should be considered 477 * 478 * Return: true if the packet should be forwarded, false otherwise 479 */ 480 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv, 481 const struct ethhdr *ethhdr, 482 const struct batadv_ogm2_packet *ogm2, 483 struct batadv_orig_node *orig_node, 484 struct batadv_neigh_node *neigh_node, 485 struct batadv_hard_iface *if_incoming, 486 struct batadv_hard_iface *if_outgoing) 487 { 488 struct batadv_neigh_node *router = NULL; 489 struct batadv_orig_node *orig_neigh_node = NULL; 490 struct batadv_neigh_node *orig_neigh_router = NULL; 491 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; 492 u32 router_throughput, neigh_throughput; 493 u32 router_last_seqno; 494 u32 neigh_last_seqno; 495 s32 neigh_seq_diff; 496 bool forward = false; 497 498 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); 499 if (!orig_neigh_node) 500 goto out; 501 502 orig_neigh_router = batadv_orig_router_get(orig_neigh_node, 503 if_outgoing); 504 505 /* drop packet if sender is not a direct neighbor and if we 506 * don't route towards it 507 */ 508 router = batadv_orig_router_get(orig_node, if_outgoing); 509 if (router && router->orig_node != orig_node && !orig_neigh_router) { 510 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 511 "Drop packet: OGM via unknown neighbor!\n"); 512 goto out; 513 } 514 515 /* Mark the OGM to be considered for forwarding, and update routes 516 * if needed. 517 */ 518 forward = true; 519 520 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 521 "Searching and updating originator entry of received packet\n"); 522 523 /* if this neighbor already is our next hop there is nothing 524 * to change 525 */ 526 if (router == neigh_node) 527 goto out; 528 529 /* don't consider neighbours with worse throughput. 530 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than 531 * the last received seqno from our best next hop. 532 */ 533 if (router) { 534 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); 535 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 536 537 /* if these are not allocated, something is wrong. */ 538 if (!router_ifinfo || !neigh_ifinfo) 539 goto out; 540 541 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; 542 router_last_seqno = router_ifinfo->bat_v.last_seqno; 543 neigh_seq_diff = neigh_last_seqno - router_last_seqno; 544 router_throughput = router_ifinfo->bat_v.throughput; 545 neigh_throughput = neigh_ifinfo->bat_v.throughput; 546 547 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) && 548 (router_throughput >= neigh_throughput)) 549 goto out; 550 } 551 552 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); 553 out: 554 if (router) 555 batadv_neigh_node_put(router); 556 if (orig_neigh_router) 557 batadv_neigh_node_put(orig_neigh_router); 558 if (orig_neigh_node) 559 batadv_orig_node_put(orig_neigh_node); 560 if (router_ifinfo) 561 batadv_neigh_ifinfo_put(router_ifinfo); 562 if (neigh_ifinfo) 563 batadv_neigh_ifinfo_put(neigh_ifinfo); 564 565 return forward; 566 } 567 568 /** 569 * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if 570 * @bat_priv: the bat priv with all the soft interface information 571 * @ethhdr: the Ethernet header of the OGM2 572 * @ogm2: OGM2 structure 573 * @orig_node: Originator structure for which the OGM has been received 574 * @neigh_node: the neigh_node through with the OGM has been received 575 * @if_incoming: the interface where this packet was received 576 * @if_outgoing: the interface for which the packet should be considered 577 */ 578 static void 579 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, 580 const struct ethhdr *ethhdr, 581 const struct batadv_ogm2_packet *ogm2, 582 struct batadv_orig_node *orig_node, 583 struct batadv_neigh_node *neigh_node, 584 struct batadv_hard_iface *if_incoming, 585 struct batadv_hard_iface *if_outgoing) 586 { 587 int seqno_age; 588 bool forward; 589 590 /* first, update the metric with according sanity checks */ 591 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, 592 neigh_node, if_incoming, 593 if_outgoing); 594 595 /* outdated sequence numbers are to be discarded */ 596 if (seqno_age < 0) 597 return; 598 599 /* only unknown & newer OGMs contain TVLVs we are interested in */ 600 if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT)) 601 batadv_tvlv_containers_process(bat_priv, true, orig_node, 602 NULL, NULL, 603 (unsigned char *)(ogm2 + 1), 604 ntohs(ogm2->tvlv_len)); 605 606 /* if the metric update went through, update routes if needed */ 607 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, 608 neigh_node, if_incoming, 609 if_outgoing); 610 611 /* if the routes have been processed correctly, check and forward */ 612 if (forward) 613 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node, 614 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_get_or_create(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 if (!kref_get_unless_zero(&hard_iface->refcount)) 717 continue; 718 719 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, 720 orig_node, neigh_node, 721 if_incoming, hard_iface); 722 723 batadv_hardif_put(hard_iface); 724 } 725 rcu_read_unlock(); 726 out: 727 if (orig_node) 728 batadv_orig_node_put(orig_node); 729 if (neigh_node) 730 batadv_neigh_node_put(neigh_node); 731 if (hardif_neigh) 732 batadv_hardif_neigh_put(hardif_neigh); 733 } 734 735 /** 736 * batadv_v_ogm_packet_recv - OGM2 receiving handler 737 * @skb: the received OGM 738 * @if_incoming: the interface where this OGM has been received 739 * 740 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP 741 * (without freeing the skb) on failure 742 */ 743 int batadv_v_ogm_packet_recv(struct sk_buff *skb, 744 struct batadv_hard_iface *if_incoming) 745 { 746 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 747 struct batadv_ogm2_packet *ogm_packet; 748 struct ethhdr *ethhdr = eth_hdr(skb); 749 int ogm_offset; 750 u8 *packet_pos; 751 int ret = NET_RX_DROP; 752 753 /* did we receive a OGM2 packet on an interface that does not have 754 * B.A.T.M.A.N. V enabled ? 755 */ 756 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) 757 return NET_RX_DROP; 758 759 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) 760 return NET_RX_DROP; 761 762 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 763 return NET_RX_DROP; 764 765 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 766 767 if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) 768 return NET_RX_DROP; 769 770 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); 771 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, 772 skb->len + ETH_HLEN); 773 774 ogm_offset = 0; 775 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 776 777 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), 778 ogm_packet->tvlv_len)) { 779 batadv_v_ogm_process(skb, ogm_offset, if_incoming); 780 781 ogm_offset += BATADV_OGM2_HLEN; 782 ogm_offset += ntohs(ogm_packet->tvlv_len); 783 784 packet_pos = skb->data + ogm_offset; 785 ogm_packet = (struct batadv_ogm2_packet *)packet_pos; 786 } 787 788 ret = NET_RX_SUCCESS; 789 consume_skb(skb); 790 791 return ret; 792 } 793 794 /** 795 * batadv_v_ogm_init - initialise the OGM2 engine 796 * @bat_priv: the bat priv with all the soft interface information 797 * 798 * Return: 0 on success or a negative error code in case of failure 799 */ 800 int batadv_v_ogm_init(struct batadv_priv *bat_priv) 801 { 802 struct batadv_ogm2_packet *ogm_packet; 803 unsigned char *ogm_buff; 804 u32 random_seqno; 805 806 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN; 807 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC); 808 if (!ogm_buff) 809 return -ENOMEM; 810 811 bat_priv->bat_v.ogm_buff = ogm_buff; 812 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff; 813 ogm_packet->packet_type = BATADV_OGM2; 814 ogm_packet->version = BATADV_COMPAT_VERSION; 815 ogm_packet->ttl = BATADV_TTL; 816 ogm_packet->flags = BATADV_NO_FLAGS; 817 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE); 818 819 /* randomize initial seqno to avoid collision */ 820 get_random_bytes(&random_seqno, sizeof(random_seqno)); 821 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno); 822 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send); 823 824 return 0; 825 } 826 827 /** 828 * batadv_v_ogm_free - free OGM private resources 829 * @bat_priv: the bat priv with all the soft interface information 830 */ 831 void batadv_v_ogm_free(struct batadv_priv *bat_priv) 832 { 833 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq); 834 835 kfree(bat_priv->bat_v.ogm_buff); 836 bat_priv->bat_v.ogm_buff = NULL; 837 bat_priv->bat_v.ogm_buff_len = 0; 838 } 839