1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (C) B.A.T.M.A.N. contributors: 3 * 4 * Linus L��ssing, Marek Lindner 5 */ 6 7#include "bat_v_elp.h" 8#include "main.h" 9 10#include <linux/atomic.h> 11#include <linux/bitops.h> 12#include <linux/byteorder/generic.h> 13#include <linux/container_of.h> 14#include <linux/errno.h> 15#include <linux/etherdevice.h> 16#include <linux/ethtool.h> 17#include <linux/gfp.h> 18#include <linux/if_ether.h> 19#include <linux/jiffies.h> 20#include <linux/kref.h> 21#include <linux/minmax.h> 22#include <linux/netdevice.h> 23#include <linux/nl80211.h> 24#include <linux/random.h> 25#include <linux/rculist.h> 26#include <linux/rcupdate.h> 27#include <linux/rtnetlink.h> 28#include <linux/skbuff.h> 29#include <linux/stddef.h> 30#include <linux/string.h> 31#include <linux/types.h> 32#include <linux/workqueue.h> 33#include <net/cfg80211.h> 34#include <uapi/linux/batadv_packet.h> 35 36#include "bat_algo.h" 37#include "bat_v_ogm.h" 38#include "hard-interface.h" 39#include "log.h" 40#include "originator.h" 41#include "routing.h" 42#include "send.h" 43 44/** 45 * batadv_v_elp_start_timer() - restart timer for ELP periodic work 46 * @hard_iface: the interface for which the timer has to be reset 47 */ 48static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface) 49{ 50 unsigned int msecs; 51 52 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER; 53 msecs += get_random_u32_below(2 * BATADV_JITTER); 54 55 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq, 56 msecs_to_jiffies(msecs)); 57} 58 59/** 60 * batadv_v_elp_get_throughput() - get the throughput towards a neighbour 61 * @neigh: the neighbour for which the throughput has to be obtained 62 * 63 * Return: The throughput towards the given neighbour in multiples of 100kpbs 64 * (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc). 65 */ 66static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) 67{ 68 struct batadv_hard_iface *hard_iface = neigh->if_incoming; 69 struct ethtool_link_ksettings link_settings; 70 struct net_device *real_netdev; 71 struct station_info sinfo; 72 u32 throughput; 73 int ret; 74 75 /* if the user specified a customised value for this interface, then 76 * return it directly 77 */ 78 throughput = atomic_read(&hard_iface->bat_v.throughput_override); 79 if (throughput != 0) 80 return throughput; 81 82 /* if this is a wireless device, then ask its throughput through 83 * cfg80211 API 84 */ 85 if (batadv_is_wifi_hardif(hard_iface)) { 86 if (!batadv_is_cfg80211_hardif(hard_iface)) 87 /* unsupported WiFi driver version */ 88 goto default_throughput; 89 90 real_netdev = batadv_get_real_netdev(hard_iface->net_dev); 91 if (!real_netdev) 92 goto default_throughput; 93 94 ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo); 95 96 if (!ret) { 97 /* free the TID stats immediately */ 98 cfg80211_sinfo_release_content(&sinfo); 99 } 100 101 dev_put(real_netdev); 102 if (ret == -ENOENT) { 103 /* Node is not associated anymore! It would be 104 * possible to delete this neighbor. For now set 105 * the throughput metric to 0. 106 */ 107 return 0; 108 } 109 if (ret) 110 goto default_throughput; 111 112 if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)) 113 return sinfo.expected_throughput / 100; 114 115 /* try to estimate the expected throughput based on reported tx 116 * rates 117 */ 118 if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)) 119 return cfg80211_calculate_bitrate(&sinfo.txrate) / 3; 120 121 goto default_throughput; 122 } 123 124 /* if not a wifi interface, check if this device provides data via 125 * ethtool (e.g. an Ethernet adapter) 126 */ 127 rtnl_lock(); 128 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings); 129 rtnl_unlock(); 130 if (ret == 0) { 131 /* link characteristics might change over time */ 132 if (link_settings.base.duplex == DUPLEX_FULL) 133 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX; 134 else 135 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX; 136 137 throughput = link_settings.base.speed; 138 if (throughput && throughput != SPEED_UNKNOWN) 139 return throughput * 10; 140 } 141 142default_throughput: 143 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) { 144 batadv_info(hard_iface->soft_iface, 145 "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n", 146 hard_iface->net_dev->name, 147 BATADV_THROUGHPUT_DEFAULT_VALUE / 10, 148 BATADV_THROUGHPUT_DEFAULT_VALUE % 10); 149 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT; 150 } 151 152 /* if none of the above cases apply, return the base_throughput */ 153 return BATADV_THROUGHPUT_DEFAULT_VALUE; 154} 155 156/** 157 * batadv_v_elp_throughput_metric_update() - worker updating the throughput 158 * metric of a single hop neighbour 159 * @work: the work queue item 160 */ 161void batadv_v_elp_throughput_metric_update(struct work_struct *work) 162{ 163 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v; 164 struct batadv_hardif_neigh_node *neigh; 165 166 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v, 167 metric_work); 168 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node, 169 bat_v); 170 171 ewma_throughput_add(&neigh->bat_v.throughput, 172 batadv_v_elp_get_throughput(neigh)); 173 174 /* decrement refcounter to balance increment performed before scheduling 175 * this task 176 */ 177 batadv_hardif_neigh_put(neigh); 178} 179 180/** 181 * batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour 182 * @neigh: the neighbour to probe 183 * 184 * Sends a predefined number of unicast wifi packets to a given neighbour in 185 * order to trigger the throughput estimation on this link by the RC algorithm. 186 * Packets are sent only if there is not enough payload unicast traffic towards 187 * this neighbour.. 188 * 189 * Return: True on success and false in case of error during skb preparation. 190 */ 191static bool 192batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh) 193{ 194 struct batadv_hard_iface *hard_iface = neigh->if_incoming; 195 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 196 unsigned long last_tx_diff; 197 struct sk_buff *skb; 198 int probe_len, i; 199 int elp_skb_len; 200 201 /* this probing routine is for Wifi neighbours only */ 202 if (!batadv_is_wifi_hardif(hard_iface)) 203 return true; 204 205 /* probe the neighbor only if no unicast packets have been sent 206 * to it in the last 100 milliseconds: this is the rate control 207 * algorithm sampling interval (minstrel). In this way, if not 208 * enough traffic has been sent to the neighbor, batman-adv can 209 * generate 2 probe packets and push the RC algorithm to perform 210 * the sampling 211 */ 212 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx); 213 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF) 214 return true; 215 216 probe_len = max_t(int, sizeof(struct batadv_elp_packet), 217 BATADV_ELP_MIN_PROBE_SIZE); 218 219 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) { 220 elp_skb_len = hard_iface->bat_v.elp_skb->len; 221 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0, 222 probe_len - elp_skb_len, 223 GFP_ATOMIC); 224 if (!skb) 225 return false; 226 227 /* Tell the skb to get as big as the allocated space (we want 228 * the packet to be exactly of that size to make the link 229 * throughput estimation effective. 230 */ 231 skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len); 232 233 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 234 "Sending unicast (probe) ELP packet on interface %s to %pM\n", 235 hard_iface->net_dev->name, neigh->addr); 236 237 batadv_send_skb_packet(skb, hard_iface, neigh->addr); 238 } 239 240 return true; 241} 242 243/** 244 * batadv_v_elp_periodic_work() - ELP periodic task per interface 245 * @work: work queue item 246 * 247 * Emits broadcast ELP messages in regular intervals. 248 */ 249static void batadv_v_elp_periodic_work(struct work_struct *work) 250{ 251 struct batadv_hardif_neigh_node *hardif_neigh; 252 struct batadv_hard_iface *hard_iface; 253 struct batadv_hard_iface_bat_v *bat_v; 254 struct batadv_elp_packet *elp_packet; 255 struct batadv_priv *bat_priv; 256 struct sk_buff *skb; 257 u32 elp_interval; 258 bool ret; 259 260 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work); 261 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v); 262 bat_priv = netdev_priv(hard_iface->soft_iface); 263 264 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) 265 goto out; 266 267 /* we are in the process of shutting this interface down */ 268 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE || 269 hard_iface->if_status == BATADV_IF_TO_BE_REMOVED) 270 goto out; 271 272 /* the interface was enabled but may not be ready yet */ 273 if (hard_iface->if_status != BATADV_IF_ACTIVE) 274 goto restart_timer; 275 276 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC); 277 if (!skb) 278 goto restart_timer; 279 280 elp_packet = (struct batadv_elp_packet *)skb->data; 281 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno)); 282 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval); 283 elp_packet->elp_interval = htonl(elp_interval); 284 285 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 286 "Sending broadcast ELP packet on interface %s, seqno %u\n", 287 hard_iface->net_dev->name, 288 atomic_read(&hard_iface->bat_v.elp_seqno)); 289 290 batadv_send_broadcast_skb(skb, hard_iface); 291 292 atomic_inc(&hard_iface->bat_v.elp_seqno); 293 294 /* The throughput metric is updated on each sent packet. This way, if a 295 * node is dead and no longer sends packets, batman-adv is still able to 296 * react timely to its death. 297 * 298 * The throughput metric is updated by following these steps: 299 * 1) if the hard_iface is wifi => send a number of unicast ELPs for 300 * probing/sampling to each neighbor 301 * 2) update the throughput metric value of each neighbor (note that the 302 * value retrieved in this step might be 100ms old because the 303 * probing packets at point 1) could still be in the HW queue) 304 */ 305 rcu_read_lock(); 306 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) { 307 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh)) 308 /* if something goes wrong while probing, better to stop 309 * sending packets immediately and reschedule the task 310 */ 311 break; 312 313 if (!kref_get_unless_zero(&hardif_neigh->refcount)) 314 continue; 315 316 /* Reading the estimated throughput from cfg80211 is a task that 317 * may sleep and that is not allowed in an rcu protected 318 * context. Therefore schedule a task for that. 319 */ 320 ret = queue_work(batadv_event_workqueue, 321 &hardif_neigh->bat_v.metric_work); 322 323 if (!ret) 324 batadv_hardif_neigh_put(hardif_neigh); 325 } 326 rcu_read_unlock(); 327 328restart_timer: 329 batadv_v_elp_start_timer(hard_iface); 330out: 331 return; 332} 333 334/** 335 * batadv_v_elp_iface_enable() - setup the ELP interface private resources 336 * @hard_iface: interface for which the data has to be prepared 337 * 338 * Return: 0 on success or a -ENOMEM in case of failure. 339 */ 340int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) 341{ 342 static const size_t tvlv_padding = sizeof(__be32); 343 struct batadv_elp_packet *elp_packet; 344 unsigned char *elp_buff; 345 u32 random_seqno; 346 size_t size; 347 int res = -ENOMEM; 348 349 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding; 350 hard_iface->bat_v.elp_skb = dev_alloc_skb(size); 351 if (!hard_iface->bat_v.elp_skb) 352 goto out; 353 354 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN); 355 elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, 356 BATADV_ELP_HLEN + tvlv_padding); 357 elp_packet = (struct batadv_elp_packet *)elp_buff; 358 359 elp_packet->packet_type = BATADV_ELP; 360 elp_packet->version = BATADV_COMPAT_VERSION; 361 362 /* randomize initial seqno to avoid collision */ 363 get_random_bytes(&random_seqno, sizeof(random_seqno)); 364 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno); 365 366 /* assume full-duplex by default */ 367 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX; 368 369 /* warn the user (again) if there is no throughput data is available */ 370 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT; 371 372 if (batadv_is_wifi_hardif(hard_iface)) 373 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX; 374 375 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq, 376 batadv_v_elp_periodic_work); 377 batadv_v_elp_start_timer(hard_iface); 378 res = 0; 379 380out: 381 return res; 382} 383 384/** 385 * batadv_v_elp_iface_disable() - release ELP interface private resources 386 * @hard_iface: interface for which the resources have to be released 387 */ 388void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface) 389{ 390 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq); 391 392 dev_kfree_skb(hard_iface->bat_v.elp_skb); 393 hard_iface->bat_v.elp_skb = NULL; 394} 395 396/** 397 * batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given 398 * hard-interface 399 * @primary_iface: the new primary interface 400 * @hard_iface: interface holding the to-be-updated buffer 401 */ 402void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface, 403 struct batadv_hard_iface *hard_iface) 404{ 405 struct batadv_elp_packet *elp_packet; 406 struct sk_buff *skb; 407 408 if (!hard_iface->bat_v.elp_skb) 409 return; 410 411 skb = hard_iface->bat_v.elp_skb; 412 elp_packet = (struct batadv_elp_packet *)skb->data; 413 ether_addr_copy(elp_packet->orig, 414 primary_iface->net_dev->dev_addr); 415} 416 417/** 418 * batadv_v_elp_primary_iface_set() - change internal data to reflect the new 419 * primary interface 420 * @primary_iface: the new primary interface 421 */ 422void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface) 423{ 424 struct batadv_hard_iface *hard_iface; 425 426 /* update orig field of every elp iface belonging to this mesh */ 427 rcu_read_lock(); 428 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 429 if (primary_iface->soft_iface != hard_iface->soft_iface) 430 continue; 431 432 batadv_v_elp_iface_activate(primary_iface, hard_iface); 433 } 434 rcu_read_unlock(); 435} 436 437/** 438 * batadv_v_elp_neigh_update() - update an ELP neighbour node 439 * @bat_priv: the bat priv with all the soft interface information 440 * @neigh_addr: the neighbour interface address 441 * @if_incoming: the interface the packet was received through 442 * @elp_packet: the received ELP packet 443 * 444 * Updates the ELP neighbour node state with the data received within the new 445 * ELP packet. 446 */ 447static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv, 448 u8 *neigh_addr, 449 struct batadv_hard_iface *if_incoming, 450 struct batadv_elp_packet *elp_packet) 451 452{ 453 struct batadv_neigh_node *neigh; 454 struct batadv_orig_node *orig_neigh; 455 struct batadv_hardif_neigh_node *hardif_neigh; 456 s32 seqno_diff; 457 s32 elp_latest_seqno; 458 459 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig); 460 if (!orig_neigh) 461 return; 462 463 neigh = batadv_neigh_node_get_or_create(orig_neigh, 464 if_incoming, neigh_addr); 465 if (!neigh) 466 goto orig_free; 467 468 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr); 469 if (!hardif_neigh) 470 goto neigh_free; 471 472 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno; 473 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno; 474 475 /* known or older sequence numbers are ignored. However always adopt 476 * if the router seems to have been restarted. 477 */ 478 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE) 479 goto hardif_free; 480 481 neigh->last_seen = jiffies; 482 hardif_neigh->last_seen = jiffies; 483 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno); 484 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval); 485 486hardif_free: 487 batadv_hardif_neigh_put(hardif_neigh); 488neigh_free: 489 batadv_neigh_node_put(neigh); 490orig_free: 491 batadv_orig_node_put(orig_neigh); 492} 493 494/** 495 * batadv_v_elp_packet_recv() - main ELP packet handler 496 * @skb: the received packet 497 * @if_incoming: the interface this packet was received through 498 * 499 * Return: NET_RX_SUCCESS and consumes the skb if the packet was properly 500 * processed or NET_RX_DROP in case of failure. 501 */ 502int batadv_v_elp_packet_recv(struct sk_buff *skb, 503 struct batadv_hard_iface *if_incoming) 504{ 505 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); 506 struct batadv_elp_packet *elp_packet; 507 struct batadv_hard_iface *primary_if; 508 struct ethhdr *ethhdr; 509 bool res; 510 int ret = NET_RX_DROP; 511 512 res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); 513 if (!res) 514 goto free_skb; 515 516 ethhdr = eth_hdr(skb); 517 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 518 goto free_skb; 519 520 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface 521 * that does not have B.A.T.M.A.N. V ELP enabled ? 522 */ 523 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) 524 goto free_skb; 525 526 elp_packet = (struct batadv_elp_packet *)skb->data; 527 528 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 529 "Received ELP packet from %pM seqno %u ORIG: %pM\n", 530 ethhdr->h_source, ntohl(elp_packet->seqno), 531 elp_packet->orig); 532 533 primary_if = batadv_primary_if_get_selected(bat_priv); 534 if (!primary_if) 535 goto free_skb; 536 537 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming, 538 elp_packet); 539 540 ret = NET_RX_SUCCESS; 541 batadv_hardif_put(primary_if); 542 543free_skb: 544 if (ret == NET_RX_SUCCESS) 545 consume_skb(skb); 546 else 547 kfree_skb(skb); 548 549 return ret; 550} 551