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 "hard-interface.h" 43 #include "hash.h" 44 #include "originator.h" 45 #include "packet.h" 46 #include "routing.h" 47 #include "send.h" 48 #include "translation-table.h" 49 50 /** 51 * batadv_v_ogm_orig_get - retrieve and possibly create an originator node 52 * @bat_priv: the bat priv with all the soft interface information 53 * @addr: the address of the originator 54 * 55 * Return: the orig_node corresponding to the specified address. If such object 56 * does not exist it is allocated here. In case of allocation failure returns 57 * NULL. 58 */ 59 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, 60 const u8 *addr) 61 { 62 struct batadv_orig_node *orig_node; 63 int hash_added; 64 65 orig_node = batadv_orig_hash_find(bat_priv, addr); 66 if (orig_node) 67 return orig_node; 68 69 orig_node = batadv_orig_node_new(bat_priv, addr); 70 if (!orig_node) 71 return NULL; 72 73 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, 74 batadv_choose_orig, orig_node, 75 &orig_node->hash_entry); 76 if (hash_added != 0) { 77 /* orig_node->refcounter is initialised to 2 by 78 * batadv_orig_node_new() 79 */ 80 batadv_orig_node_put(orig_node); 81 batadv_orig_node_put(orig_node); 82 orig_node = NULL; 83 } 84 85 return orig_node; 86 } 87 88 /** 89 * batadv_v_ogm_start_timer - restart the OGM sending timer 90 * @bat_priv: the bat priv with all the soft interface information 91 */ 92 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) 93 { 94 unsigned long msecs; 95 /* this function may be invoked in different contexts (ogm rescheduling 96 * or hard_iface activation), but the work timer should not be reset 97 */ 98 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq)) 99 return; 100 101 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; 102 msecs += prandom_u32() % (2 * BATADV_JITTER); 103 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, 104 msecs_to_jiffies(msecs)); 105 } 106 107 /** 108 * batadv_v_ogm_send_to_if - send a batman ogm using a given interface 109 * @skb: the OGM to send 110 * @hard_iface: the interface to use to send the OGM 111 */ 112 static void batadv_v_ogm_send_to_if(struct sk_buff *skb, 113 struct batadv_hard_iface *hard_iface) 114 { 115 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 116 117 if (hard_iface->if_status != BATADV_IF_ACTIVE) 118 return; 119 120 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX); 121 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES, 122 skb->len + ETH_HLEN); 123 124 batadv_send_broadcast_skb(skb, hard_iface); 125 } 126 127 /** 128 * batadv_v_ogm_send - periodic worker broadcasting the own OGM 129 * @work: work queue item 130 */ 131 static void batadv_v_ogm_send(struct work_struct *work) 132 { 133 struct batadv_hard_iface *hard_iface; 134 struct batadv_priv_bat_v *bat_v; 135 struct batadv_priv *bat_priv; 136 struct batadv_ogm2_packet *ogm_packet; 137 struct sk_buff *skb, *skb_tmp; 138 unsigned char *ogm_buff, *pkt_buff; 139 int ogm_buff_len; 140 u16 tvlv_len = 0; 141 142 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work); 143 bat_priv = container_of(bat_v, struct batadv_priv, bat_v); 144 145 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) 146 goto out; 147 148 ogm_buff = bat_priv->bat_v.ogm_buff; 149 ogm_buff_len = bat_priv->bat_v.ogm_buff_len; 150 /* tt changes have to be committed before the tvlv data is 151 * appended as it may alter the tt tvlv container 152 */ 153 batadv_tt_local_commit_changes(bat_priv); 154 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, 155 &ogm_buff_len, 156 BATADV_OGM2_HLEN); 157 158 bat_priv->bat_v.ogm_buff = ogm_buff; 159 bat_priv->bat_v.ogm_buff_len = ogm_buff_len; 160 161 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); 162 if (!skb) 163 goto reschedule; 164 165 skb_reserve(skb, ETH_HLEN); 166 pkt_buff = skb_put(skb, ogm_buff_len); 167 memcpy(pkt_buff, ogm_buff, ogm_buff_len); 168 169 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 170 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); 171 atomic_inc(&bat_priv->bat_v.ogm_seqno); 172 ogm_packet->tvlv_len = htons(tvlv_len); 173 174 /* broadcast on every interface */ 175 rcu_read_lock(); 176 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 177 if (hard_iface->soft_iface != bat_priv->soft_iface) 178 continue; 179 180 if (!kref_get_unless_zero(&hard_iface->refcount)) 181 continue; 182 183 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 184 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n", 185 ogm_packet->orig, ntohl(ogm_packet->seqno), 186 ntohl(ogm_packet->throughput), ogm_packet->ttl, 187 hard_iface->net_dev->name, 188 hard_iface->net_dev->dev_addr); 189 190 /* this skb gets consumed by batadv_v_ogm_send_to_if() */ 191 skb_tmp = skb_clone(skb, GFP_ATOMIC); 192 if (!skb_tmp) { 193 batadv_hardif_put(hard_iface); 194 break; 195 } 196 197 batadv_v_ogm_send_to_if(skb_tmp, hard_iface); 198 batadv_hardif_put(hard_iface); 199 } 200 rcu_read_unlock(); 201 202 consume_skb(skb); 203 204 reschedule: 205 batadv_v_ogm_start_timer(bat_priv); 206 out: 207 return; 208 } 209 210 /** 211 * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V 212 * @hard_iface: the interface to prepare 213 * 214 * Takes care of scheduling own OGM sending routine for this interface. 215 * 216 * Return: 0 on success or a negative error code otherwise 217 */ 218 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface) 219 { 220 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 221 222 batadv_v_ogm_start_timer(bat_priv); 223 224 return 0; 225 } 226 227 /** 228 * batadv_v_ogm_primary_iface_set - set a new primary interface 229 * @primary_iface: the new primary interface 230 */ 231 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) 232 { 233 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface); 234 struct batadv_ogm2_packet *ogm_packet; 235 236 if (!bat_priv->bat_v.ogm_buff) 237 return; 238 239 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff; 240 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr); 241 } 242 243 /** 244 * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded 245 * with B.A.T.M.A.N. V OGMs 246 * @bat_priv: the bat priv with all the soft interface information 247 * @if_incoming: the interface where the OGM has been received 248 * @if_outgoing: the interface where the OGM has to be forwarded to 249 * @throughput: the current throughput 250 * 251 * Apply a penalty on the current throughput metric value based on the 252 * characteristic of the interface where the OGM has been received. The return 253 * value is computed as follows: 254 * - throughput * 50% if the incoming and outgoing interface are the 255 * same WiFi interface and the throughput is above 256 * 1MBit/s 257 * - throughput if the outgoing interface is the default 258 * interface (i.e. this OGM is processed for the 259 * internal table and not forwarded) 260 * - throughput * hop penalty otherwise 261 * 262 * Return: the penalised throughput metric. 263 */ 264 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, 265 struct batadv_hard_iface *if_incoming, 266 struct batadv_hard_iface *if_outgoing, 267 u32 throughput) 268 { 269 int hop_penalty = atomic_read(&bat_priv->hop_penalty); 270 int hop_penalty_max = BATADV_TQ_MAX_VALUE; 271 272 /* Don't apply hop penalty in default originator table. */ 273 if (if_outgoing == BATADV_IF_DEFAULT) 274 return throughput; 275 276 /* Forwarding on the same WiFi interface cuts the throughput in half 277 * due to the store & forward characteristics of WIFI. 278 * Very low throughput values are the exception. 279 */ 280 if ((throughput > 10) && 281 (if_incoming == if_outgoing) && 282 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX)) 283 return throughput / 2; 284 285 /* hop penalty of 255 equals 100% */ 286 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; 287 } 288 289 /** 290 * batadv_v_ogm_forward - check conditions and forward an OGM to the given 291 * outgoing interface 292 * @bat_priv: the bat priv with all the soft interface information 293 * @ogm_received: previously received OGM to be forwarded 294 * @orig_node: the originator which has been updated 295 * @neigh_node: the neigh_node through with the OGM has been received 296 * @if_incoming: the interface on which this OGM was received on 297 * @if_outgoing: the interface to which the OGM has to be forwarded to 298 * 299 * Forward an OGM to an interface after having altered the throughput metric and 300 * the TTL value contained in it. The original OGM isn't modified. 301 */ 302 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, 303 const struct batadv_ogm2_packet *ogm_received, 304 struct batadv_orig_node *orig_node, 305 struct batadv_neigh_node *neigh_node, 306 struct batadv_hard_iface *if_incoming, 307 struct batadv_hard_iface *if_outgoing) 308 { 309 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 310 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 311 struct batadv_neigh_node *router = NULL; 312 struct batadv_ogm2_packet *ogm_forward; 313 unsigned char *skb_buff; 314 struct sk_buff *skb; 315 size_t packet_len; 316 u16 tvlv_len; 317 318 /* only forward for specific interfaces, not for the default one. */ 319 if (if_outgoing == BATADV_IF_DEFAULT) 320 goto out; 321 322 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 323 if (!orig_ifinfo) 324 goto out; 325 326 /* acquire possibly updated router */ 327 router = batadv_orig_router_get(orig_node, if_outgoing); 328 329 /* strict rule: forward packets coming from the best next hop only */ 330 if (neigh_node != router) 331 goto out; 332 333 /* don't forward the same seqno twice on one interface */ 334 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno)) 335 goto out; 336 337 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno); 338 339 if (ogm_received->ttl <= 1) { 340 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); 341 goto out; 342 } 343 344 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 345 if (!neigh_ifinfo) 346 goto out; 347 348 tvlv_len = ntohs(ogm_received->tvlv_len); 349 350 packet_len = BATADV_OGM2_HLEN + tvlv_len; 351 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, 352 ETH_HLEN + packet_len); 353 if (!skb) 354 goto out; 355 356 skb_reserve(skb, ETH_HLEN); 357 skb_buff = skb_put(skb, packet_len); 358 memcpy(skb_buff, ogm_received, packet_len); 359 360 /* apply forward penalty */ 361 ogm_forward = (struct batadv_ogm2_packet *)skb_buff; 362 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput); 363 ogm_forward->ttl--; 364 365 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 366 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", 367 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), 368 ogm_forward->ttl, if_incoming->net_dev->name); 369 370 batadv_v_ogm_send_to_if(skb, if_outgoing); 371 372 out: 373 if (orig_ifinfo) 374 batadv_orig_ifinfo_put(orig_ifinfo); 375 if (router) 376 batadv_neigh_node_put(router); 377 if (neigh_ifinfo) 378 batadv_neigh_ifinfo_put(neigh_ifinfo); 379 } 380 381 /** 382 * batadv_v_ogm_metric_update - update route metric based on OGM 383 * @bat_priv: the bat priv with all the soft interface information 384 * @ogm2: OGM2 structure 385 * @orig_node: Originator structure for which the OGM has been received 386 * @neigh_node: the neigh_node through with the OGM has been received 387 * @if_incoming: the interface where this packet was received 388 * @if_outgoing: the interface for which the packet should be considered 389 * 390 * Return: 391 * 1 if the OGM is new, 392 * 0 if it is not new but valid, 393 * <0 on error (e.g. old OGM) 394 */ 395 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, 396 const struct batadv_ogm2_packet *ogm2, 397 struct batadv_orig_node *orig_node, 398 struct batadv_neigh_node *neigh_node, 399 struct batadv_hard_iface *if_incoming, 400 struct batadv_hard_iface *if_outgoing) 401 { 402 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 403 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 404 bool protection_started = false; 405 int ret = -EINVAL; 406 u32 path_throughput; 407 s32 seq_diff; 408 409 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 410 if (!orig_ifinfo) 411 goto out; 412 413 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; 414 415 if (!hlist_empty(&orig_node->neigh_list) && 416 batadv_window_protected(bat_priv, seq_diff, 417 BATADV_OGM_MAX_AGE, 418 &orig_ifinfo->batman_seqno_reset, 419 &protection_started)) { 420 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 421 "Drop packet: packet within window protection time from %pM\n", 422 ogm2->orig); 423 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 424 "Last reset: %ld, %ld\n", 425 orig_ifinfo->batman_seqno_reset, jiffies); 426 goto out; 427 } 428 429 /* drop packets with old seqnos, however accept the first packet after 430 * a host has been rebooted. 431 */ 432 if ((seq_diff < 0) && !protection_started) 433 goto out; 434 435 neigh_node->last_seen = jiffies; 436 437 orig_node->last_seen = jiffies; 438 439 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); 440 orig_ifinfo->last_ttl = ogm2->ttl; 441 442 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); 443 if (!neigh_ifinfo) 444 goto out; 445 446 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, 447 if_outgoing, 448 ntohl(ogm2->throughput)); 449 neigh_ifinfo->bat_v.throughput = path_throughput; 450 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); 451 neigh_ifinfo->last_ttl = ogm2->ttl; 452 453 if (seq_diff > 0 || protection_started) 454 ret = 1; 455 else 456 ret = 0; 457 out: 458 if (orig_ifinfo) 459 batadv_orig_ifinfo_put(orig_ifinfo); 460 if (neigh_ifinfo) 461 batadv_neigh_ifinfo_put(neigh_ifinfo); 462 463 return ret; 464 } 465 466 /** 467 * batadv_v_ogm_route_update - update routes based on OGM 468 * @bat_priv: the bat priv with all the soft interface information 469 * @ethhdr: the Ethernet header of the OGM2 470 * @ogm2: OGM2 structure 471 * @orig_node: Originator structure for which the OGM has been received 472 * @neigh_node: the neigh_node through with the OGM has been received 473 * @if_incoming: the interface where this packet was received 474 * @if_outgoing: the interface for which the packet should be considered 475 * 476 * Return: true if the packet should be forwarded, false otherwise 477 */ 478 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv, 479 const struct ethhdr *ethhdr, 480 const struct batadv_ogm2_packet *ogm2, 481 struct batadv_orig_node *orig_node, 482 struct batadv_neigh_node *neigh_node, 483 struct batadv_hard_iface *if_incoming, 484 struct batadv_hard_iface *if_outgoing) 485 { 486 struct batadv_neigh_node *router = NULL; 487 struct batadv_orig_node *orig_neigh_node = NULL; 488 struct batadv_neigh_node *orig_neigh_router = NULL; 489 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; 490 u32 router_throughput, neigh_throughput; 491 u32 router_last_seqno; 492 u32 neigh_last_seqno; 493 s32 neigh_seq_diff; 494 bool forward = false; 495 496 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); 497 if (!orig_neigh_node) 498 goto out; 499 500 orig_neigh_router = batadv_orig_router_get(orig_neigh_node, 501 if_outgoing); 502 503 /* drop packet if sender is not a direct neighbor and if we 504 * don't route towards it 505 */ 506 router = batadv_orig_router_get(orig_node, if_outgoing); 507 if (router && router->orig_node != orig_node && !orig_neigh_router) { 508 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 509 "Drop packet: OGM via unknown neighbor!\n"); 510 goto out; 511 } 512 513 /* Mark the OGM to be considered for forwarding, and update routes 514 * if needed. 515 */ 516 forward = true; 517 518 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 519 "Searching and updating originator entry of received packet\n"); 520 521 /* if this neighbor already is our next hop there is nothing 522 * to change 523 */ 524 if (router == neigh_node) 525 goto out; 526 527 /* don't consider neighbours with worse throughput. 528 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than 529 * the last received seqno from our best next hop. 530 */ 531 if (router) { 532 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); 533 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 534 535 /* if these are not allocated, something is wrong. */ 536 if (!router_ifinfo || !neigh_ifinfo) 537 goto out; 538 539 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; 540 router_last_seqno = router_ifinfo->bat_v.last_seqno; 541 neigh_seq_diff = neigh_last_seqno - router_last_seqno; 542 router_throughput = router_ifinfo->bat_v.throughput; 543 neigh_throughput = neigh_ifinfo->bat_v.throughput; 544 545 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) && 546 (router_throughput >= neigh_throughput)) 547 goto out; 548 } 549 550 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); 551 out: 552 if (router) 553 batadv_neigh_node_put(router); 554 if (orig_neigh_router) 555 batadv_neigh_node_put(orig_neigh_router); 556 if (orig_neigh_node) 557 batadv_orig_node_put(orig_neigh_node); 558 if (router_ifinfo) 559 batadv_neigh_ifinfo_put(router_ifinfo); 560 if (neigh_ifinfo) 561 batadv_neigh_ifinfo_put(neigh_ifinfo); 562 563 return forward; 564 } 565 566 /** 567 * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if 568 * @bat_priv: the bat priv with all the soft interface information 569 * @ethhdr: the Ethernet header of the OGM2 570 * @ogm2: OGM2 structure 571 * @orig_node: Originator structure for which the OGM has been received 572 * @neigh_node: the neigh_node through with the OGM has been received 573 * @if_incoming: the interface where this packet was received 574 * @if_outgoing: the interface for which the packet should be considered 575 */ 576 static void 577 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, 578 const struct ethhdr *ethhdr, 579 const struct batadv_ogm2_packet *ogm2, 580 struct batadv_orig_node *orig_node, 581 struct batadv_neigh_node *neigh_node, 582 struct batadv_hard_iface *if_incoming, 583 struct batadv_hard_iface *if_outgoing) 584 { 585 int seqno_age; 586 bool forward; 587 588 /* first, update the metric with according sanity checks */ 589 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, 590 neigh_node, if_incoming, 591 if_outgoing); 592 593 /* outdated sequence numbers are to be discarded */ 594 if (seqno_age < 0) 595 return; 596 597 /* only unknown & newer OGMs contain TVLVs we are interested in */ 598 if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT)) 599 batadv_tvlv_containers_process(bat_priv, true, orig_node, 600 NULL, NULL, 601 (unsigned char *)(ogm2 + 1), 602 ntohs(ogm2->tvlv_len)); 603 604 /* if the metric update went through, update routes if needed */ 605 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, 606 neigh_node, if_incoming, 607 if_outgoing); 608 609 /* if the routes have been processed correctly, check and forward */ 610 if (forward) 611 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node, 612 if_incoming, if_outgoing); 613 } 614 615 /** 616 * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated 617 * @buff_pos: current position in the skb 618 * @packet_len: total length of the skb 619 * @tvlv_len: tvlv length of the previously considered OGM 620 * 621 * Return: true if there is enough space for another OGM, false otherwise. 622 */ 623 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, 624 __be16 tvlv_len) 625 { 626 int next_buff_pos = 0; 627 628 next_buff_pos += buff_pos + BATADV_OGM2_HLEN; 629 next_buff_pos += ntohs(tvlv_len); 630 631 return (next_buff_pos <= packet_len) && 632 (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); 633 } 634 635 /** 636 * batadv_v_ogm_process - process an incoming batman v OGM 637 * @skb: the skb containing the OGM 638 * @ogm_offset: offset to the OGM which should be processed (for aggregates) 639 * @if_incoming: the interface where this packet was receved 640 */ 641 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, 642 struct batadv_hard_iface *if_incoming) 643 { 644 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 645 struct ethhdr *ethhdr; 646 struct batadv_orig_node *orig_node = NULL; 647 struct batadv_hardif_neigh_node *hardif_neigh = NULL; 648 struct batadv_neigh_node *neigh_node = NULL; 649 struct batadv_hard_iface *hard_iface; 650 struct batadv_ogm2_packet *ogm_packet; 651 u32 ogm_throughput, link_throughput, path_throughput; 652 653 ethhdr = eth_hdr(skb); 654 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset); 655 656 ogm_throughput = ntohl(ogm_packet->throughput); 657 658 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 659 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n", 660 ethhdr->h_source, if_incoming->net_dev->name, 661 if_incoming->net_dev->dev_addr, ogm_packet->orig, 662 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, 663 ogm_packet->version, ntohs(ogm_packet->tvlv_len)); 664 665 /* If the troughput metric is 0, immediately drop the packet. No need to 666 * create orig_node / neigh_node for an unusable route. 667 */ 668 if (ogm_throughput == 0) { 669 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 670 "Drop packet: originator packet with troughput metric of 0\n"); 671 return; 672 } 673 674 /* require ELP packets be to received from this neighbor first */ 675 hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source); 676 if (!hardif_neigh) { 677 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 678 "Drop packet: OGM via unknown neighbor!\n"); 679 goto out; 680 } 681 682 orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig); 683 if (!orig_node) 684 return; 685 686 neigh_node = batadv_neigh_node_new(orig_node, if_incoming, 687 ethhdr->h_source); 688 if (!neigh_node) 689 goto out; 690 691 /* Update the received throughput metric to match the link 692 * characteristic: 693 * - If this OGM traveled one hop so far (emitted by single hop 694 * neighbor) the path throughput metric equals the link throughput. 695 * - For OGMs traversing more than hop the path throughput metric is 696 * the smaller of the path throughput and the link throughput. 697 */ 698 link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput); 699 path_throughput = min_t(u32, link_throughput, ogm_throughput); 700 ogm_packet->throughput = htonl(path_throughput); 701 702 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node, 703 neigh_node, if_incoming, 704 BATADV_IF_DEFAULT); 705 706 rcu_read_lock(); 707 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 708 if (hard_iface->if_status != BATADV_IF_ACTIVE) 709 continue; 710 711 if (hard_iface->soft_iface != bat_priv->soft_iface) 712 continue; 713 714 if (!kref_get_unless_zero(&hard_iface->refcount)) 715 continue; 716 717 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, 718 orig_node, neigh_node, 719 if_incoming, hard_iface); 720 721 batadv_hardif_put(hard_iface); 722 } 723 rcu_read_unlock(); 724 out: 725 if (orig_node) 726 batadv_orig_node_put(orig_node); 727 if (neigh_node) 728 batadv_neigh_node_put(neigh_node); 729 if (hardif_neigh) 730 batadv_hardif_neigh_put(hardif_neigh); 731 } 732 733 /** 734 * batadv_v_ogm_packet_recv - OGM2 receiving handler 735 * @skb: the received OGM 736 * @if_incoming: the interface where this OGM has been received 737 * 738 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP 739 * (without freeing the skb) on failure 740 */ 741 int batadv_v_ogm_packet_recv(struct sk_buff *skb, 742 struct batadv_hard_iface *if_incoming) 743 { 744 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 745 struct batadv_ogm2_packet *ogm_packet; 746 struct ethhdr *ethhdr = eth_hdr(skb); 747 int ogm_offset; 748 u8 *packet_pos; 749 int ret = NET_RX_DROP; 750 751 /* did we receive a OGM2 packet on an interface that does not have 752 * B.A.T.M.A.N. V enabled ? 753 */ 754 if (strcmp(bat_priv->bat_algo_ops->name, "BATMAN_V") != 0) 755 return NET_RX_DROP; 756 757 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) 758 return NET_RX_DROP; 759 760 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 761 return NET_RX_DROP; 762 763 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 764 765 if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) 766 return NET_RX_DROP; 767 768 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); 769 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, 770 skb->len + ETH_HLEN); 771 772 ogm_offset = 0; 773 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 774 775 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), 776 ogm_packet->tvlv_len)) { 777 batadv_v_ogm_process(skb, ogm_offset, if_incoming); 778 779 ogm_offset += BATADV_OGM2_HLEN; 780 ogm_offset += ntohs(ogm_packet->tvlv_len); 781 782 packet_pos = skb->data + ogm_offset; 783 ogm_packet = (struct batadv_ogm2_packet *)packet_pos; 784 } 785 786 ret = NET_RX_SUCCESS; 787 consume_skb(skb); 788 789 return ret; 790 } 791 792 /** 793 * batadv_v_ogm_init - initialise the OGM2 engine 794 * @bat_priv: the bat priv with all the soft interface information 795 * 796 * Return: 0 on success or a negative error code in case of failure 797 */ 798 int batadv_v_ogm_init(struct batadv_priv *bat_priv) 799 { 800 struct batadv_ogm2_packet *ogm_packet; 801 unsigned char *ogm_buff; 802 u32 random_seqno; 803 804 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN; 805 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC); 806 if (!ogm_buff) 807 return -ENOMEM; 808 809 bat_priv->bat_v.ogm_buff = ogm_buff; 810 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff; 811 ogm_packet->packet_type = BATADV_OGM2; 812 ogm_packet->version = BATADV_COMPAT_VERSION; 813 ogm_packet->ttl = BATADV_TTL; 814 ogm_packet->flags = BATADV_NO_FLAGS; 815 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE); 816 817 /* randomize initial seqno to avoid collision */ 818 get_random_bytes(&random_seqno, sizeof(random_seqno)); 819 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno); 820 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send); 821 822 return 0; 823 } 824 825 /** 826 * batadv_v_ogm_free - free OGM private resources 827 * @bat_priv: the bat priv with all the soft interface information 828 */ 829 void batadv_v_ogm_free(struct batadv_priv *bat_priv) 830 { 831 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq); 832 833 kfree(bat_priv->bat_v.ogm_buff); 834 bat_priv->bat_v.ogm_buff = NULL; 835 bat_priv->bat_v.ogm_buff_len = 0; 836 } 837