1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (C) B.A.T.M.A.N. contributors: 3 * 4 * Antonio Quartulli 5 */ 6 7#include "bat_v_ogm.h" 8#include "main.h" 9 10#include <linux/atomic.h> 11#include <linux/byteorder/generic.h> 12#include <linux/container_of.h> 13#include <linux/errno.h> 14#include <linux/etherdevice.h> 15#include <linux/gfp.h> 16#include <linux/if_ether.h> 17#include <linux/jiffies.h> 18#include <linux/kref.h> 19#include <linux/list.h> 20#include <linux/lockdep.h> 21#include <linux/minmax.h> 22#include <linux/mutex.h> 23#include <linux/netdevice.h> 24#include <linux/random.h> 25#include <linux/rculist.h> 26#include <linux/rcupdate.h> 27#include <linux/skbuff.h> 28#include <linux/slab.h> 29#include <linux/spinlock.h> 30#include <linux/stddef.h> 31#include <linux/string.h> 32#include <linux/types.h> 33#include <linux/workqueue.h> 34#include <uapi/linux/batadv_packet.h> 35 36#include "bat_algo.h" 37#include "hard-interface.h" 38#include "hash.h" 39#include "log.h" 40#include "originator.h" 41#include "routing.h" 42#include "send.h" 43#include "translation-table.h" 44#include "tvlv.h" 45 46/** 47 * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node 48 * @bat_priv: the bat priv with all the soft interface information 49 * @addr: the address of the originator 50 * 51 * Return: the orig_node corresponding to the specified address. If such an 52 * object does not exist, it is allocated here. In case of allocation failure 53 * returns NULL. 54 */ 55struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, 56 const u8 *addr) 57{ 58 struct batadv_orig_node *orig_node; 59 int hash_added; 60 61 orig_node = batadv_orig_hash_find(bat_priv, addr); 62 if (orig_node) 63 return orig_node; 64 65 orig_node = batadv_orig_node_new(bat_priv, addr); 66 if (!orig_node) 67 return NULL; 68 69 kref_get(&orig_node->refcount); 70 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, 71 batadv_choose_orig, orig_node, 72 &orig_node->hash_entry); 73 if (hash_added != 0) { 74 /* remove refcnt for newly created orig_node and hash entry */ 75 batadv_orig_node_put(orig_node); 76 batadv_orig_node_put(orig_node); 77 orig_node = NULL; 78 } 79 80 return orig_node; 81} 82 83/** 84 * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer 85 * @hard_iface: the interface to use to send the OGM 86 */ 87static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface) 88{ 89 unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000; 90 91 /* msecs * [0.9, 1.1] */ 92 msecs += get_random_u32_below(msecs / 5) - (msecs / 10); 93 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq, 94 msecs_to_jiffies(msecs / 1000)); 95} 96 97/** 98 * batadv_v_ogm_start_timer() - restart the OGM sending timer 99 * @bat_priv: the bat priv with all the soft interface information 100 */ 101static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) 102{ 103 unsigned long msecs; 104 /* this function may be invoked in different contexts (ogm rescheduling 105 * or hard_iface activation), but the work timer should not be reset 106 */ 107 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq)) 108 return; 109 110 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; 111 msecs += get_random_u32_below(2 * BATADV_JITTER); 112 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, 113 msecs_to_jiffies(msecs)); 114} 115 116/** 117 * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface 118 * @skb: the OGM to send 119 * @hard_iface: the interface to use to send the OGM 120 */ 121static void batadv_v_ogm_send_to_if(struct sk_buff *skb, 122 struct batadv_hard_iface *hard_iface) 123{ 124 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 125 126 if (hard_iface->if_status != BATADV_IF_ACTIVE) { 127 kfree_skb(skb); 128 return; 129 } 130 131 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX); 132 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES, 133 skb->len + ETH_HLEN); 134 135 batadv_send_broadcast_skb(skb, hard_iface); 136} 137 138/** 139 * batadv_v_ogm_len() - OGMv2 packet length 140 * @skb: the OGM to check 141 * 142 * Return: Length of the given OGMv2 packet, including tvlv length, excluding 143 * ethernet header length. 144 */ 145static unsigned int batadv_v_ogm_len(struct sk_buff *skb) 146{ 147 struct batadv_ogm2_packet *ogm_packet; 148 149 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 150 return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len); 151} 152 153/** 154 * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue 155 * @skb: the OGM to check 156 * @hard_iface: the interface to use to send the OGM 157 * 158 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. 159 * 160 * Return: True, if the given OGMv2 packet still fits, false otherwise. 161 */ 162static bool batadv_v_ogm_queue_left(struct sk_buff *skb, 163 struct batadv_hard_iface *hard_iface) 164{ 165 unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu, 166 BATADV_MAX_AGGREGATION_BYTES); 167 unsigned int ogm_len = batadv_v_ogm_len(skb); 168 169 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); 170 171 return hard_iface->bat_v.aggr_len + ogm_len <= max; 172} 173 174/** 175 * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue 176 * @hard_iface: the interface holding the aggregation queue 177 * 178 * Empties the OGMv2 aggregation queue and frees all the skbs it contains. 179 * 180 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. 181 */ 182static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) 183{ 184 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); 185 186 __skb_queue_purge(&hard_iface->bat_v.aggr_list); 187 hard_iface->bat_v.aggr_len = 0; 188} 189 190/** 191 * batadv_v_ogm_aggr_send() - flush & send aggregation queue 192 * @hard_iface: the interface with the aggregation queue to flush 193 * 194 * Aggregates all OGMv2 packets currently in the aggregation queue into a 195 * single OGMv2 packet and transmits this aggregate. 196 * 197 * The aggregation queue is empty after this call. 198 * 199 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. 200 */ 201static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) 202{ 203 unsigned int aggr_len = hard_iface->bat_v.aggr_len; 204 struct sk_buff *skb_aggr; 205 unsigned int ogm_len; 206 struct sk_buff *skb; 207 208 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); 209 210 if (!aggr_len) 211 return; 212 213 skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN); 214 if (!skb_aggr) { 215 batadv_v_ogm_aggr_list_free(hard_iface); 216 return; 217 } 218 219 skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN); 220 skb_reset_network_header(skb_aggr); 221 222 while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) { 223 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb); 224 225 ogm_len = batadv_v_ogm_len(skb); 226 skb_put_data(skb_aggr, skb->data, ogm_len); 227 228 consume_skb(skb); 229 } 230 231 batadv_v_ogm_send_to_if(skb_aggr, hard_iface); 232} 233 234/** 235 * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface 236 * @skb: the OGM to queue 237 * @hard_iface: the interface to queue the OGM on 238 */ 239static void batadv_v_ogm_queue_on_if(struct sk_buff *skb, 240 struct batadv_hard_iface *hard_iface) 241{ 242 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 243 244 if (!atomic_read(&bat_priv->aggregated_ogms)) { 245 batadv_v_ogm_send_to_if(skb, hard_iface); 246 return; 247 } 248 249 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); 250 if (!batadv_v_ogm_queue_left(skb, hard_iface)) 251 batadv_v_ogm_aggr_send(hard_iface); 252 253 hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); 254 __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); 255 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); 256} 257 258/** 259 * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM 260 * @bat_priv: the bat priv with all the soft interface information 261 */ 262static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv) 263{ 264 struct batadv_hard_iface *hard_iface; 265 struct batadv_ogm2_packet *ogm_packet; 266 struct sk_buff *skb, *skb_tmp; 267 unsigned char *ogm_buff; 268 int ogm_buff_len; 269 u16 tvlv_len = 0; 270 int ret; 271 272 lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex); 273 274 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) 275 goto out; 276 277 ogm_buff = bat_priv->bat_v.ogm_buff; 278 ogm_buff_len = bat_priv->bat_v.ogm_buff_len; 279 /* tt changes have to be committed before the tvlv data is 280 * appended as it may alter the tt tvlv container 281 */ 282 batadv_tt_local_commit_changes(bat_priv); 283 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, 284 &ogm_buff_len, 285 BATADV_OGM2_HLEN); 286 287 bat_priv->bat_v.ogm_buff = ogm_buff; 288 bat_priv->bat_v.ogm_buff_len = ogm_buff_len; 289 290 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); 291 if (!skb) 292 goto reschedule; 293 294 skb_reserve(skb, ETH_HLEN); 295 skb_put_data(skb, ogm_buff, ogm_buff_len); 296 297 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 298 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); 299 atomic_inc(&bat_priv->bat_v.ogm_seqno); 300 ogm_packet->tvlv_len = htons(tvlv_len); 301 302 /* broadcast on every interface */ 303 rcu_read_lock(); 304 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 305 if (hard_iface->soft_iface != bat_priv->soft_iface) 306 continue; 307 308 if (!kref_get_unless_zero(&hard_iface->refcount)) 309 continue; 310 311 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL); 312 if (ret) { 313 char *type; 314 315 switch (ret) { 316 case BATADV_HARDIF_BCAST_NORECIPIENT: 317 type = "no neighbor"; 318 break; 319 case BATADV_HARDIF_BCAST_DUPFWD: 320 type = "single neighbor is source"; 321 break; 322 case BATADV_HARDIF_BCAST_DUPORIG: 323 type = "single neighbor is originator"; 324 break; 325 default: 326 type = "unknown"; 327 } 328 329 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n", 330 hard_iface->net_dev->name, type); 331 332 batadv_hardif_put(hard_iface); 333 continue; 334 } 335 336 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 337 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n", 338 ogm_packet->orig, ntohl(ogm_packet->seqno), 339 ntohl(ogm_packet->throughput), ogm_packet->ttl, 340 hard_iface->net_dev->name, 341 hard_iface->net_dev->dev_addr); 342 343 /* this skb gets consumed by batadv_v_ogm_send_to_if() */ 344 skb_tmp = skb_clone(skb, GFP_ATOMIC); 345 if (!skb_tmp) { 346 batadv_hardif_put(hard_iface); 347 break; 348 } 349 350 batadv_v_ogm_queue_on_if(skb_tmp, hard_iface); 351 batadv_hardif_put(hard_iface); 352 } 353 rcu_read_unlock(); 354 355 consume_skb(skb); 356 357reschedule: 358 batadv_v_ogm_start_timer(bat_priv); 359out: 360 return; 361} 362 363/** 364 * batadv_v_ogm_send() - periodic worker broadcasting the own OGM 365 * @work: work queue item 366 */ 367static void batadv_v_ogm_send(struct work_struct *work) 368{ 369 struct batadv_priv_bat_v *bat_v; 370 struct batadv_priv *bat_priv; 371 372 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work); 373 bat_priv = container_of(bat_v, struct batadv_priv, bat_v); 374 375 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); 376 batadv_v_ogm_send_softif(bat_priv); 377 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); 378} 379 380/** 381 * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface 382 * @work: work queue item 383 * 384 * Emits aggregated OGM messages in regular intervals. 385 */ 386void batadv_v_ogm_aggr_work(struct work_struct *work) 387{ 388 struct batadv_hard_iface_bat_v *batv; 389 struct batadv_hard_iface *hard_iface; 390 391 batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work); 392 hard_iface = container_of(batv, struct batadv_hard_iface, bat_v); 393 394 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); 395 batadv_v_ogm_aggr_send(hard_iface); 396 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); 397 398 batadv_v_ogm_start_queue_timer(hard_iface); 399} 400 401/** 402 * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V 403 * @hard_iface: the interface to prepare 404 * 405 * Takes care of scheduling its own OGM sending routine for this interface. 406 * 407 * Return: 0 on success or a negative error code otherwise 408 */ 409int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface) 410{ 411 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 412 413 batadv_v_ogm_start_queue_timer(hard_iface); 414 batadv_v_ogm_start_timer(bat_priv); 415 416 return 0; 417} 418 419/** 420 * batadv_v_ogm_iface_disable() - release OGM interface private resources 421 * @hard_iface: interface for which the resources have to be released 422 */ 423void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface) 424{ 425 cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq); 426 427 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); 428 batadv_v_ogm_aggr_list_free(hard_iface); 429 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); 430} 431 432/** 433 * batadv_v_ogm_primary_iface_set() - set a new primary interface 434 * @primary_iface: the new primary interface 435 */ 436void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) 437{ 438 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface); 439 struct batadv_ogm2_packet *ogm_packet; 440 441 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); 442 if (!bat_priv->bat_v.ogm_buff) 443 goto unlock; 444 445 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff; 446 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr); 447 448unlock: 449 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); 450} 451 452/** 453 * batadv_v_forward_penalty() - apply a penalty to the throughput metric 454 * forwarded with B.A.T.M.A.N. V OGMs 455 * @bat_priv: the bat priv with all the soft interface information 456 * @if_incoming: the interface where the OGM has been received 457 * @if_outgoing: the interface where the OGM has to be forwarded to 458 * @throughput: the current throughput 459 * 460 * Apply a penalty on the current throughput metric value based on the 461 * characteristic of the interface where the OGM has been received. 462 * 463 * Initially the per hardif hop penalty is applied to the throughput. After 464 * that the return value is then computed as follows: 465 * - throughput * 50% if the incoming and outgoing interface are the 466 * same WiFi interface and the throughput is above 467 * 1MBit/s 468 * - throughput if the outgoing interface is the default 469 * interface (i.e. this OGM is processed for the 470 * internal table and not forwarded) 471 * - throughput * node hop penalty otherwise 472 * 473 * Return: the penalised throughput metric. 474 */ 475static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, 476 struct batadv_hard_iface *if_incoming, 477 struct batadv_hard_iface *if_outgoing, 478 u32 throughput) 479{ 480 int if_hop_penalty = atomic_read(&if_incoming->hop_penalty); 481 int hop_penalty = atomic_read(&bat_priv->hop_penalty); 482 int hop_penalty_max = BATADV_TQ_MAX_VALUE; 483 484 /* Apply per hardif hop penalty */ 485 throughput = throughput * (hop_penalty_max - if_hop_penalty) / 486 hop_penalty_max; 487 488 /* Don't apply hop penalty in default originator table. */ 489 if (if_outgoing == BATADV_IF_DEFAULT) 490 return throughput; 491 492 /* Forwarding on the same WiFi interface cuts the throughput in half 493 * due to the store & forward characteristics of WIFI. 494 * Very low throughput values are the exception. 495 */ 496 if (throughput > 10 && 497 if_incoming == if_outgoing && 498 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX)) 499 return throughput / 2; 500 501 /* hop penalty of 255 equals 100% */ 502 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; 503} 504 505/** 506 * batadv_v_ogm_forward() - check conditions and forward an OGM to the given 507 * outgoing interface 508 * @bat_priv: the bat priv with all the soft interface information 509 * @ogm_received: previously received OGM to be forwarded 510 * @orig_node: the originator which has been updated 511 * @neigh_node: the neigh_node through with the OGM has been received 512 * @if_incoming: the interface on which this OGM was received on 513 * @if_outgoing: the interface to which the OGM has to be forwarded to 514 * 515 * Forward an OGM to an interface after having altered the throughput metric and 516 * the TTL value contained in it. The original OGM isn't modified. 517 */ 518static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, 519 const struct batadv_ogm2_packet *ogm_received, 520 struct batadv_orig_node *orig_node, 521 struct batadv_neigh_node *neigh_node, 522 struct batadv_hard_iface *if_incoming, 523 struct batadv_hard_iface *if_outgoing) 524{ 525 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 526 struct batadv_orig_ifinfo *orig_ifinfo = NULL; 527 struct batadv_neigh_node *router = NULL; 528 struct batadv_ogm2_packet *ogm_forward; 529 unsigned char *skb_buff; 530 struct sk_buff *skb; 531 size_t packet_len; 532 u16 tvlv_len; 533 534 /* only forward for specific interfaces, not for the default one. */ 535 if (if_outgoing == BATADV_IF_DEFAULT) 536 goto out; 537 538 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 539 if (!orig_ifinfo) 540 goto out; 541 542 /* acquire possibly updated router */ 543 router = batadv_orig_router_get(orig_node, if_outgoing); 544 545 /* strict rule: forward packets coming from the best next hop only */ 546 if (neigh_node != router) 547 goto out; 548 549 /* don't forward the same seqno twice on one interface */ 550 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno)) 551 goto out; 552 553 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno); 554 555 if (ogm_received->ttl <= 1) { 556 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); 557 goto out; 558 } 559 560 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 561 if (!neigh_ifinfo) 562 goto out; 563 564 tvlv_len = ntohs(ogm_received->tvlv_len); 565 566 packet_len = BATADV_OGM2_HLEN + tvlv_len; 567 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, 568 ETH_HLEN + packet_len); 569 if (!skb) 570 goto out; 571 572 skb_reserve(skb, ETH_HLEN); 573 skb_buff = skb_put_data(skb, ogm_received, packet_len); 574 575 /* apply forward penalty */ 576 ogm_forward = (struct batadv_ogm2_packet *)skb_buff; 577 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput); 578 ogm_forward->ttl--; 579 580 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 581 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", 582 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), 583 ogm_forward->ttl, if_incoming->net_dev->name); 584 585 batadv_v_ogm_queue_on_if(skb, if_outgoing); 586 587out: 588 batadv_orig_ifinfo_put(orig_ifinfo); 589 batadv_neigh_node_put(router); 590 batadv_neigh_ifinfo_put(neigh_ifinfo); 591} 592 593/** 594 * batadv_v_ogm_metric_update() - update route metric based on OGM 595 * @bat_priv: the bat priv with all the soft interface information 596 * @ogm2: OGM2 structure 597 * @orig_node: Originator structure for which the OGM has been received 598 * @neigh_node: the neigh_node through with the OGM has been received 599 * @if_incoming: the interface where this packet was received 600 * @if_outgoing: the interface for which the packet should be considered 601 * 602 * Return: 603 * 1 if the OGM is new, 604 * 0 if it is not new but valid, 605 * <0 on error (e.g. old OGM) 606 */ 607static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, 608 const struct batadv_ogm2_packet *ogm2, 609 struct batadv_orig_node *orig_node, 610 struct batadv_neigh_node *neigh_node, 611 struct batadv_hard_iface *if_incoming, 612 struct batadv_hard_iface *if_outgoing) 613{ 614 struct batadv_orig_ifinfo *orig_ifinfo; 615 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; 616 bool protection_started = false; 617 int ret = -EINVAL; 618 u32 path_throughput; 619 s32 seq_diff; 620 621 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); 622 if (!orig_ifinfo) 623 goto out; 624 625 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; 626 627 if (!hlist_empty(&orig_node->neigh_list) && 628 batadv_window_protected(bat_priv, seq_diff, 629 BATADV_OGM_MAX_AGE, 630 &orig_ifinfo->batman_seqno_reset, 631 &protection_started)) { 632 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 633 "Drop packet: packet within window protection time from %pM\n", 634 ogm2->orig); 635 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 636 "Last reset: %ld, %ld\n", 637 orig_ifinfo->batman_seqno_reset, jiffies); 638 goto out; 639 } 640 641 /* drop packets with old seqnos, however accept the first packet after 642 * a host has been rebooted. 643 */ 644 if (seq_diff < 0 && !protection_started) 645 goto out; 646 647 neigh_node->last_seen = jiffies; 648 649 orig_node->last_seen = jiffies; 650 651 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); 652 orig_ifinfo->last_ttl = ogm2->ttl; 653 654 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); 655 if (!neigh_ifinfo) 656 goto out; 657 658 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, 659 if_outgoing, 660 ntohl(ogm2->throughput)); 661 neigh_ifinfo->bat_v.throughput = path_throughput; 662 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); 663 neigh_ifinfo->last_ttl = ogm2->ttl; 664 665 if (seq_diff > 0 || protection_started) 666 ret = 1; 667 else 668 ret = 0; 669out: 670 batadv_orig_ifinfo_put(orig_ifinfo); 671 batadv_neigh_ifinfo_put(neigh_ifinfo); 672 673 return ret; 674} 675 676/** 677 * batadv_v_ogm_route_update() - update routes based on OGM 678 * @bat_priv: the bat priv with all the soft interface information 679 * @ethhdr: the Ethernet header of the OGM2 680 * @ogm2: OGM2 structure 681 * @orig_node: Originator structure for which the OGM has been received 682 * @neigh_node: the neigh_node through with the OGM has been received 683 * @if_incoming: the interface where this packet was received 684 * @if_outgoing: the interface for which the packet should be considered 685 * 686 * Return: true if the packet should be forwarded, false otherwise 687 */ 688static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv, 689 const struct ethhdr *ethhdr, 690 const struct batadv_ogm2_packet *ogm2, 691 struct batadv_orig_node *orig_node, 692 struct batadv_neigh_node *neigh_node, 693 struct batadv_hard_iface *if_incoming, 694 struct batadv_hard_iface *if_outgoing) 695{ 696 struct batadv_neigh_node *router = NULL; 697 struct batadv_orig_node *orig_neigh_node; 698 struct batadv_neigh_node *orig_neigh_router = NULL; 699 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; 700 u32 router_throughput, neigh_throughput; 701 u32 router_last_seqno; 702 u32 neigh_last_seqno; 703 s32 neigh_seq_diff; 704 bool forward = false; 705 706 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); 707 if (!orig_neigh_node) 708 goto out; 709 710 orig_neigh_router = batadv_orig_router_get(orig_neigh_node, 711 if_outgoing); 712 713 /* drop packet if sender is not a direct neighbor and if we 714 * don't route towards it 715 */ 716 router = batadv_orig_router_get(orig_node, if_outgoing); 717 if (router && router->orig_node != orig_node && !orig_neigh_router) { 718 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 719 "Drop packet: OGM via unknown neighbor!\n"); 720 goto out; 721 } 722 723 /* Mark the OGM to be considered for forwarding, and update routes 724 * if needed. 725 */ 726 forward = true; 727 728 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 729 "Searching and updating originator entry of received packet\n"); 730 731 /* if this neighbor already is our next hop there is nothing 732 * to change 733 */ 734 if (router == neigh_node) 735 goto out; 736 737 /* don't consider neighbours with worse throughput. 738 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than 739 * the last received seqno from our best next hop. 740 */ 741 if (router) { 742 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); 743 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); 744 745 /* if these are not allocated, something is wrong. */ 746 if (!router_ifinfo || !neigh_ifinfo) 747 goto out; 748 749 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; 750 router_last_seqno = router_ifinfo->bat_v.last_seqno; 751 neigh_seq_diff = neigh_last_seqno - router_last_seqno; 752 router_throughput = router_ifinfo->bat_v.throughput; 753 neigh_throughput = neigh_ifinfo->bat_v.throughput; 754 755 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF && 756 router_throughput >= neigh_throughput) 757 goto out; 758 } 759 760 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); 761out: 762 batadv_neigh_node_put(router); 763 batadv_neigh_node_put(orig_neigh_router); 764 batadv_orig_node_put(orig_neigh_node); 765 batadv_neigh_ifinfo_put(router_ifinfo); 766 batadv_neigh_ifinfo_put(neigh_ifinfo); 767 768 return forward; 769} 770 771/** 772 * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if 773 * @bat_priv: the bat priv with all the soft interface information 774 * @ethhdr: the Ethernet header of the OGM2 775 * @ogm2: OGM2 structure 776 * @orig_node: Originator structure for which the OGM has been received 777 * @neigh_node: the neigh_node through with the OGM has been received 778 * @if_incoming: the interface where this packet was received 779 * @if_outgoing: the interface for which the packet should be considered 780 */ 781static void 782batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, 783 const struct ethhdr *ethhdr, 784 const struct batadv_ogm2_packet *ogm2, 785 struct batadv_orig_node *orig_node, 786 struct batadv_neigh_node *neigh_node, 787 struct batadv_hard_iface *if_incoming, 788 struct batadv_hard_iface *if_outgoing) 789{ 790 int seqno_age; 791 bool forward; 792 793 /* first, update the metric with according sanity checks */ 794 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, 795 neigh_node, if_incoming, 796 if_outgoing); 797 798 /* outdated sequence numbers are to be discarded */ 799 if (seqno_age < 0) 800 return; 801 802 /* only unknown & newer OGMs contain TVLVs we are interested in */ 803 if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT) 804 batadv_tvlv_containers_process(bat_priv, BATADV_OGM2, orig_node, 805 NULL, 806 (unsigned char *)(ogm2 + 1), 807 ntohs(ogm2->tvlv_len)); 808 809 /* if the metric update went through, update routes if needed */ 810 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, 811 neigh_node, if_incoming, 812 if_outgoing); 813 814 /* if the routes have been processed correctly, check and forward */ 815 if (forward) 816 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node, 817 if_incoming, if_outgoing); 818} 819 820/** 821 * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated 822 * @buff_pos: current position in the skb 823 * @packet_len: total length of the skb 824 * @ogm2_packet: potential OGM2 in buffer 825 * 826 * Return: true if there is enough space for another OGM, false otherwise. 827 */ 828static bool 829batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, 830 const struct batadv_ogm2_packet *ogm2_packet) 831{ 832 int next_buff_pos = 0; 833 834 /* check if there is enough space for the header */ 835 next_buff_pos += buff_pos + sizeof(*ogm2_packet); 836 if (next_buff_pos > packet_len) 837 return false; 838 839 /* check if there is enough space for the optional TVLV */ 840 next_buff_pos += ntohs(ogm2_packet->tvlv_len); 841 842 return (next_buff_pos <= packet_len) && 843 (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); 844} 845 846/** 847 * batadv_v_ogm_process() - process an incoming batman v OGM 848 * @skb: the skb containing the OGM 849 * @ogm_offset: offset to the OGM which should be processed (for aggregates) 850 * @if_incoming: the interface where this packet was received 851 */ 852static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, 853 struct batadv_hard_iface *if_incoming) 854{ 855 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 856 struct ethhdr *ethhdr; 857 struct batadv_orig_node *orig_node = NULL; 858 struct batadv_hardif_neigh_node *hardif_neigh = NULL; 859 struct batadv_neigh_node *neigh_node = NULL; 860 struct batadv_hard_iface *hard_iface; 861 struct batadv_ogm2_packet *ogm_packet; 862 u32 ogm_throughput, link_throughput, path_throughput; 863 int ret; 864 865 ethhdr = eth_hdr(skb); 866 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset); 867 868 ogm_throughput = ntohl(ogm_packet->throughput); 869 870 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 871 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n", 872 ethhdr->h_source, if_incoming->net_dev->name, 873 if_incoming->net_dev->dev_addr, ogm_packet->orig, 874 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, 875 ogm_packet->version, ntohs(ogm_packet->tvlv_len)); 876 877 if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) { 878 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 879 "Drop packet: originator packet from ourself\n"); 880 return; 881 } 882 883 /* If the throughput metric is 0, immediately drop the packet. No need 884 * to create orig_node / neigh_node for an unusable route. 885 */ 886 if (ogm_throughput == 0) { 887 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 888 "Drop packet: originator packet with throughput metric of 0\n"); 889 return; 890 } 891 892 /* require ELP packets be to received from this neighbor first */ 893 hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source); 894 if (!hardif_neigh) { 895 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 896 "Drop packet: OGM via unknown neighbor!\n"); 897 goto out; 898 } 899 900 orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig); 901 if (!orig_node) 902 goto out; 903 904 neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming, 905 ethhdr->h_source); 906 if (!neigh_node) 907 goto out; 908 909 /* Update the received throughput metric to match the link 910 * characteristic: 911 * - If this OGM traveled one hop so far (emitted by single hop 912 * neighbor) the path throughput metric equals the link throughput. 913 * - For OGMs traversing more than hop the path throughput metric is 914 * the smaller of the path throughput and the link throughput. 915 */ 916 link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput); 917 path_throughput = min_t(u32, link_throughput, ogm_throughput); 918 ogm_packet->throughput = htonl(path_throughput); 919 920 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node, 921 neigh_node, if_incoming, 922 BATADV_IF_DEFAULT); 923 924 rcu_read_lock(); 925 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 926 if (hard_iface->if_status != BATADV_IF_ACTIVE) 927 continue; 928 929 if (hard_iface->soft_iface != bat_priv->soft_iface) 930 continue; 931 932 if (!kref_get_unless_zero(&hard_iface->refcount)) 933 continue; 934 935 ret = batadv_hardif_no_broadcast(hard_iface, 936 ogm_packet->orig, 937 hardif_neigh->orig); 938 939 if (ret) { 940 char *type; 941 942 switch (ret) { 943 case BATADV_HARDIF_BCAST_NORECIPIENT: 944 type = "no neighbor"; 945 break; 946 case BATADV_HARDIF_BCAST_DUPFWD: 947 type = "single neighbor is source"; 948 break; 949 case BATADV_HARDIF_BCAST_DUPORIG: 950 type = "single neighbor is originator"; 951 break; 952 default: 953 type = "unknown"; 954 } 955 956 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n", 957 ogm_packet->orig, hard_iface->net_dev->name, 958 type); 959 960 batadv_hardif_put(hard_iface); 961 continue; 962 } 963 964 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, 965 orig_node, neigh_node, 966 if_incoming, hard_iface); 967 968 batadv_hardif_put(hard_iface); 969 } 970 rcu_read_unlock(); 971out: 972 batadv_orig_node_put(orig_node); 973 batadv_neigh_node_put(neigh_node); 974 batadv_hardif_neigh_put(hardif_neigh); 975} 976 977/** 978 * batadv_v_ogm_packet_recv() - OGM2 receiving handler 979 * @skb: the received OGM 980 * @if_incoming: the interface where this OGM has been received 981 * 982 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP 983 * (without freeing the skb) on failure 984 */ 985int batadv_v_ogm_packet_recv(struct sk_buff *skb, 986 struct batadv_hard_iface *if_incoming) 987{ 988 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 989 struct batadv_ogm2_packet *ogm_packet; 990 struct ethhdr *ethhdr; 991 int ogm_offset; 992 u8 *packet_pos; 993 int ret = NET_RX_DROP; 994 995 /* did we receive a OGM2 packet on an interface that does not have 996 * B.A.T.M.A.N. V enabled ? 997 */ 998 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) 999 goto free_skb; 1000 1001 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) 1002 goto free_skb; 1003 1004 ethhdr = eth_hdr(skb); 1005 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 1006 goto free_skb; 1007 1008 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); 1009 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, 1010 skb->len + ETH_HLEN); 1011 1012 ogm_offset = 0; 1013 ogm_packet = (struct batadv_ogm2_packet *)skb->data; 1014 1015 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), 1016 ogm_packet)) { 1017 batadv_v_ogm_process(skb, ogm_offset, if_incoming); 1018 1019 ogm_offset += BATADV_OGM2_HLEN; 1020 ogm_offset += ntohs(ogm_packet->tvlv_len); 1021 1022 packet_pos = skb->data + ogm_offset; 1023 ogm_packet = (struct batadv_ogm2_packet *)packet_pos; 1024 } 1025 1026 ret = NET_RX_SUCCESS; 1027 1028free_skb: 1029 if (ret == NET_RX_SUCCESS) 1030 consume_skb(skb); 1031 else 1032 kfree_skb(skb); 1033 1034 return ret; 1035} 1036 1037/** 1038 * batadv_v_ogm_init() - initialise the OGM2 engine 1039 * @bat_priv: the bat priv with all the soft interface information 1040 * 1041 * Return: 0 on success or a negative error code in case of failure 1042 */ 1043int batadv_v_ogm_init(struct batadv_priv *bat_priv) 1044{ 1045 struct batadv_ogm2_packet *ogm_packet; 1046 unsigned char *ogm_buff; 1047 u32 random_seqno; 1048 1049 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN; 1050 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC); 1051 if (!ogm_buff) 1052 return -ENOMEM; 1053 1054 bat_priv->bat_v.ogm_buff = ogm_buff; 1055 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff; 1056 ogm_packet->packet_type = BATADV_OGM2; 1057 ogm_packet->version = BATADV_COMPAT_VERSION; 1058 ogm_packet->ttl = BATADV_TTL; 1059 ogm_packet->flags = BATADV_NO_FLAGS; 1060 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE); 1061 1062 /* randomize initial seqno to avoid collision */ 1063 get_random_bytes(&random_seqno, sizeof(random_seqno)); 1064 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno); 1065 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send); 1066 1067 mutex_init(&bat_priv->bat_v.ogm_buff_mutex); 1068 1069 return 0; 1070} 1071 1072/** 1073 * batadv_v_ogm_free() - free OGM private resources 1074 * @bat_priv: the bat priv with all the soft interface information 1075 */ 1076void batadv_v_ogm_free(struct batadv_priv *bat_priv) 1077{ 1078 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq); 1079 1080 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); 1081 1082 kfree(bat_priv->bat_v.ogm_buff); 1083 bat_priv->bat_v.ogm_buff = NULL; 1084 bat_priv->bat_v.ogm_buff_len = 0; 1085 1086 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); 1087} 1088