| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* Copyright (C) B.A.T.M.A.N. contributors: |
| 3 | * |
| 4 | * Marek Lindner, Simon Wunderlich |
| 5 | */ |
| 6 | |
| 7 | #include "routing.h" |
| 8 | #include "main.h" |
| 9 | |
| 10 | #include <linux/atomic.h> |
| 11 | #include <linux/byteorder/generic.h> |
| 12 | #include <linux/compiler.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/etherdevice.h> |
| 15 | #include <linux/if_ether.h> |
| 16 | #include <linux/jiffies.h> |
| 17 | #include <linux/kref.h> |
| 18 | #include <linux/netdevice.h> |
| 19 | #include <linux/printk.h> |
| 20 | #include <linux/rculist.h> |
| 21 | #include <linux/rcupdate.h> |
| 22 | #include <linux/skbuff.h> |
| 23 | #include <linux/spinlock.h> |
| 24 | #include <linux/stddef.h> |
| 25 | #include <uapi/linux/batadv_packet.h> |
| 26 | |
| 27 | #include "bitarray.h" |
| 28 | #include "bridge_loop_avoidance.h" |
| 29 | #include "distributed-arp-table.h" |
| 30 | #include "fragmentation.h" |
| 31 | #include "hard-interface.h" |
| 32 | #include "log.h" |
| 33 | #include "network-coding.h" |
| 34 | #include "originator.h" |
| 35 | #include "send.h" |
| 36 | #include "soft-interface.h" |
| 37 | #include "tp_meter.h" |
| 38 | #include "translation-table.h" |
| 39 | #include "tvlv.h" |
| 40 | |
| 41 | static int batadv_route_unicast_packet(struct sk_buff *skb, |
| 42 | struct batadv_hard_iface *recv_if); |
| 43 | |
| 44 | /** |
| 45 | * _batadv_update_route() - set the router for this originator |
| 46 | * @bat_priv: the bat priv with all the soft interface information |
| 47 | * @orig_node: orig node which is to be configured |
| 48 | * @recv_if: the receive interface for which this route is set |
| 49 | * @neigh_node: neighbor which should be the next router |
| 50 | * |
| 51 | * This function does not perform any error checks |
| 52 | */ |
| 53 | static void _batadv_update_route(struct batadv_priv *bat_priv, |
| 54 | struct batadv_orig_node *orig_node, |
| 55 | struct batadv_hard_iface *recv_if, |
| 56 | struct batadv_neigh_node *neigh_node) |
| 57 | { |
| 58 | struct batadv_orig_ifinfo *orig_ifinfo; |
| 59 | struct batadv_neigh_node *curr_router; |
| 60 | |
| 61 | orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if); |
| 62 | if (!orig_ifinfo) |
| 63 | return; |
| 64 | |
| 65 | spin_lock_bh(&orig_node->neigh_list_lock); |
| 66 | /* curr_router used earlier may not be the current orig_ifinfo->router |
| 67 | * anymore because it was dereferenced outside of the neigh_list_lock |
| 68 | * protected region. After the new best neighbor has replace the current |
| 69 | * best neighbor the reference counter needs to decrease. Consequently, |
| 70 | * the code needs to ensure the curr_router variable contains a pointer |
| 71 | * to the replaced best neighbor. |
| 72 | */ |
| 73 | |
| 74 | /* increase refcount of new best neighbor */ |
| 75 | if (neigh_node) |
| 76 | kref_get(&neigh_node->refcount); |
| 77 | |
| 78 | curr_router = rcu_replace_pointer(orig_ifinfo->router, neigh_node, |
| 79 | true); |
| 80 | spin_unlock_bh(&orig_node->neigh_list_lock); |
| 81 | batadv_orig_ifinfo_put(orig_ifinfo); |
| 82 | |
| 83 | /* route deleted */ |
| 84 | if (curr_router && !neigh_node) { |
| 85 | batadv_dbg(BATADV_DBG_ROUTES, bat_priv, |
| 86 | "Deleting route towards: %pM\n", orig_node->orig); |
| 87 | batadv_tt_global_del_orig(bat_priv, orig_node, -1, |
| 88 | "Deleted route towards originator"); |
| 89 | |
| 90 | /* route added */ |
| 91 | } else if (!curr_router && neigh_node) { |
| 92 | batadv_dbg(BATADV_DBG_ROUTES, bat_priv, |
| 93 | "Adding route towards: %pM (via %pM)\n", |
| 94 | orig_node->orig, neigh_node->addr); |
| 95 | /* route changed */ |
| 96 | } else if (neigh_node && curr_router) { |
| 97 | batadv_dbg(BATADV_DBG_ROUTES, bat_priv, |
| 98 | "Changing route towards: %pM (now via %pM - was via %pM)\n", |
| 99 | orig_node->orig, neigh_node->addr, |
| 100 | curr_router->addr); |
| 101 | } |
| 102 | |
| 103 | /* decrease refcount of previous best neighbor */ |
| 104 | batadv_neigh_node_put(curr_router); |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * batadv_update_route() - set the router for this originator |
| 109 | * @bat_priv: the bat priv with all the soft interface information |
| 110 | * @orig_node: orig node which is to be configured |
| 111 | * @recv_if: the receive interface for which this route is set |
| 112 | * @neigh_node: neighbor which should be the next router |
| 113 | */ |
| 114 | void batadv_update_route(struct batadv_priv *bat_priv, |
| 115 | struct batadv_orig_node *orig_node, |
| 116 | struct batadv_hard_iface *recv_if, |
| 117 | struct batadv_neigh_node *neigh_node) |
| 118 | { |
| 119 | struct batadv_neigh_node *router = NULL; |
| 120 | |
| 121 | if (!orig_node) |
| 122 | goto out; |
| 123 | |
| 124 | router = batadv_orig_router_get(orig_node, recv_if); |
| 125 | |
| 126 | if (router != neigh_node) |
| 127 | _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node); |
| 128 | |
| 129 | out: |
| 130 | batadv_neigh_node_put(router); |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * batadv_window_protected() - checks whether the host restarted and is in the |
| 135 | * protection time. |
| 136 | * @bat_priv: the bat priv with all the soft interface information |
| 137 | * @seq_num_diff: difference between the current/received sequence number and |
| 138 | * the last sequence number |
| 139 | * @seq_old_max_diff: maximum age of sequence number not considered as restart |
| 140 | * @last_reset: jiffies timestamp of the last reset, will be updated when reset |
| 141 | * is detected |
| 142 | * @protection_started: is set to true if the protection window was started, |
| 143 | * doesn't change otherwise. |
| 144 | * |
| 145 | * Return: |
| 146 | * false if the packet is to be accepted. |
| 147 | * true if the packet is to be ignored. |
| 148 | */ |
| 149 | bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff, |
| 150 | s32 seq_old_max_diff, unsigned long *last_reset, |
| 151 | bool *protection_started) |
| 152 | { |
| 153 | if (seq_num_diff <= -seq_old_max_diff || |
| 154 | seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) { |
| 155 | if (!batadv_has_timed_out(*last_reset, |
| 156 | BATADV_RESET_PROTECTION_MS)) |
| 157 | return true; |
| 158 | |
| 159 | *last_reset = jiffies; |
| 160 | if (protection_started) |
| 161 | *protection_started = true; |
| 162 | batadv_dbg(BATADV_DBG_BATMAN, bat_priv, |
| 163 | "old packet received, start protection\n"); |
| 164 | } |
| 165 | |
| 166 | return false; |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * batadv_check_management_packet() - Check preconditions for management packets |
| 171 | * @skb: incoming packet buffer |
| 172 | * @hard_iface: incoming hard interface |
| 173 | * @header_len: minimal header length of packet type |
| 174 | * |
| 175 | * Return: true when management preconditions are met, false otherwise |
| 176 | */ |
| 177 | bool batadv_check_management_packet(struct sk_buff *skb, |
| 178 | struct batadv_hard_iface *hard_iface, |
| 179 | int header_len) |
| 180 | { |
| 181 | struct ethhdr *ethhdr; |
| 182 | |
| 183 | /* drop packet if it has not necessary minimum size */ |
| 184 | if (unlikely(!pskb_may_pull(skb, header_len))) |
| 185 | return false; |
| 186 | |
| 187 | ethhdr = eth_hdr(skb); |
| 188 | |
| 189 | /* packet with broadcast indication but unicast recipient */ |
| 190 | if (!is_broadcast_ether_addr(ethhdr->h_dest)) |
| 191 | return false; |
| 192 | |
| 193 | /* packet with invalid sender address */ |
| 194 | if (!is_valid_ether_addr(ethhdr->h_source)) |
| 195 | return false; |
| 196 | |
| 197 | /* create a copy of the skb, if needed, to modify it. */ |
| 198 | if (skb_cow(skb, 0) < 0) |
| 199 | return false; |
| 200 | |
| 201 | /* keep skb linear */ |
| 202 | if (skb_linearize(skb) < 0) |
| 203 | return false; |
| 204 | |
| 205 | return true; |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * batadv_recv_my_icmp_packet() - receive an icmp packet locally |
| 210 | * @bat_priv: the bat priv with all the soft interface information |
| 211 | * @skb: icmp packet to process |
| 212 | * |
| 213 | * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP |
| 214 | * otherwise. |
| 215 | */ |
| 216 | static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, |
| 217 | struct sk_buff *skb) |
| 218 | { |
| 219 | struct batadv_hard_iface *primary_if = NULL; |
| 220 | struct batadv_orig_node *orig_node = NULL; |
| 221 | struct batadv_icmp_header *icmph; |
| 222 | int res, ret = NET_RX_DROP; |
| 223 | |
| 224 | icmph = (struct batadv_icmp_header *)skb->data; |
| 225 | |
| 226 | switch (icmph->msg_type) { |
| 227 | case BATADV_ECHO_REQUEST: |
| 228 | /* answer echo request (ping) */ |
| 229 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| 230 | if (!primary_if) |
| 231 | goto out; |
| 232 | |
| 233 | /* get routing information */ |
| 234 | orig_node = batadv_orig_hash_find(bat_priv, icmph->orig); |
| 235 | if (!orig_node) |
| 236 | goto out; |
| 237 | |
| 238 | /* create a copy of the skb, if needed, to modify it. */ |
| 239 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 240 | goto out; |
| 241 | |
| 242 | icmph = (struct batadv_icmp_header *)skb->data; |
| 243 | |
| 244 | ether_addr_copy(icmph->dst, icmph->orig); |
| 245 | ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr); |
| 246 | icmph->msg_type = BATADV_ECHO_REPLY; |
| 247 | icmph->ttl = BATADV_TTL; |
| 248 | |
| 249 | res = batadv_send_skb_to_orig(skb, orig_node, NULL); |
| 250 | if (res == NET_XMIT_SUCCESS) |
| 251 | ret = NET_RX_SUCCESS; |
| 252 | |
| 253 | /* skb was consumed */ |
| 254 | skb = NULL; |
| 255 | break; |
| 256 | case BATADV_TP: |
| 257 | if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet))) |
| 258 | goto out; |
| 259 | |
| 260 | batadv_tp_meter_recv(bat_priv, skb); |
| 261 | ret = NET_RX_SUCCESS; |
| 262 | /* skb was consumed */ |
| 263 | skb = NULL; |
| 264 | goto out; |
| 265 | default: |
| 266 | /* drop unknown type */ |
| 267 | goto out; |
| 268 | } |
| 269 | out: |
| 270 | batadv_hardif_put(primary_if); |
| 271 | batadv_orig_node_put(orig_node); |
| 272 | |
| 273 | kfree_skb(skb); |
| 274 | |
| 275 | return ret; |
| 276 | } |
| 277 | |
| 278 | static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, |
| 279 | struct sk_buff *skb) |
| 280 | { |
| 281 | struct batadv_hard_iface *primary_if = NULL; |
| 282 | struct batadv_orig_node *orig_node = NULL; |
| 283 | struct batadv_icmp_packet *icmp_packet; |
| 284 | int res, ret = NET_RX_DROP; |
| 285 | |
| 286 | icmp_packet = (struct batadv_icmp_packet *)skb->data; |
| 287 | |
| 288 | /* send TTL exceeded if packet is an echo request (traceroute) */ |
| 289 | if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { |
| 290 | pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n", |
| 291 | icmp_packet->orig, icmp_packet->dst); |
| 292 | goto out; |
| 293 | } |
| 294 | |
| 295 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| 296 | if (!primary_if) |
| 297 | goto out; |
| 298 | |
| 299 | /* get routing information */ |
| 300 | orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); |
| 301 | if (!orig_node) |
| 302 | goto out; |
| 303 | |
| 304 | /* create a copy of the skb, if needed, to modify it. */ |
| 305 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 306 | goto out; |
| 307 | |
| 308 | icmp_packet = (struct batadv_icmp_packet *)skb->data; |
| 309 | |
| 310 | ether_addr_copy(icmp_packet->dst, icmp_packet->orig); |
| 311 | ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr); |
| 312 | icmp_packet->msg_type = BATADV_TTL_EXCEEDED; |
| 313 | icmp_packet->ttl = BATADV_TTL; |
| 314 | |
| 315 | res = batadv_send_skb_to_orig(skb, orig_node, NULL); |
| 316 | if (res == NET_RX_SUCCESS) |
| 317 | ret = NET_XMIT_SUCCESS; |
| 318 | |
| 319 | /* skb was consumed */ |
| 320 | skb = NULL; |
| 321 | |
| 322 | out: |
| 323 | batadv_hardif_put(primary_if); |
| 324 | batadv_orig_node_put(orig_node); |
| 325 | |
| 326 | kfree_skb(skb); |
| 327 | |
| 328 | return ret; |
| 329 | } |
| 330 | |
| 331 | /** |
| 332 | * batadv_recv_icmp_packet() - Process incoming icmp packet |
| 333 | * @skb: incoming packet buffer |
| 334 | * @recv_if: incoming hard interface |
| 335 | * |
| 336 | * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure |
| 337 | */ |
| 338 | int batadv_recv_icmp_packet(struct sk_buff *skb, |
| 339 | struct batadv_hard_iface *recv_if) |
| 340 | { |
| 341 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 342 | struct batadv_icmp_header *icmph; |
| 343 | struct batadv_icmp_packet_rr *icmp_packet_rr; |
| 344 | struct ethhdr *ethhdr; |
| 345 | struct batadv_orig_node *orig_node = NULL; |
| 346 | int hdr_size = sizeof(struct batadv_icmp_header); |
| 347 | int res, ret = NET_RX_DROP; |
| 348 | |
| 349 | /* drop packet if it has not necessary minimum size */ |
| 350 | if (unlikely(!pskb_may_pull(skb, hdr_size))) |
| 351 | goto free_skb; |
| 352 | |
| 353 | ethhdr = eth_hdr(skb); |
| 354 | |
| 355 | /* packet with unicast indication but non-unicast recipient */ |
| 356 | if (!is_valid_ether_addr(ethhdr->h_dest)) |
| 357 | goto free_skb; |
| 358 | |
| 359 | /* packet with broadcast/multicast sender address */ |
| 360 | if (is_multicast_ether_addr(ethhdr->h_source)) |
| 361 | goto free_skb; |
| 362 | |
| 363 | /* not for me */ |
| 364 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
| 365 | goto free_skb; |
| 366 | |
| 367 | icmph = (struct batadv_icmp_header *)skb->data; |
| 368 | |
| 369 | /* add record route information if not full */ |
| 370 | if ((icmph->msg_type == BATADV_ECHO_REPLY || |
| 371 | icmph->msg_type == BATADV_ECHO_REQUEST) && |
| 372 | skb->len >= sizeof(struct batadv_icmp_packet_rr)) { |
| 373 | if (skb_linearize(skb) < 0) |
| 374 | goto free_skb; |
| 375 | |
| 376 | /* create a copy of the skb, if needed, to modify it. */ |
| 377 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 378 | goto free_skb; |
| 379 | |
| 380 | ethhdr = eth_hdr(skb); |
| 381 | icmph = (struct batadv_icmp_header *)skb->data; |
| 382 | icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph; |
| 383 | if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN) |
| 384 | goto free_skb; |
| 385 | |
| 386 | ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur], |
| 387 | ethhdr->h_dest); |
| 388 | icmp_packet_rr->rr_cur++; |
| 389 | } |
| 390 | |
| 391 | /* packet for me */ |
| 392 | if (batadv_is_my_mac(bat_priv, icmph->dst)) |
| 393 | return batadv_recv_my_icmp_packet(bat_priv, skb); |
| 394 | |
| 395 | /* TTL exceeded */ |
| 396 | if (icmph->ttl < 2) |
| 397 | return batadv_recv_icmp_ttl_exceeded(bat_priv, skb); |
| 398 | |
| 399 | /* get routing information */ |
| 400 | orig_node = batadv_orig_hash_find(bat_priv, icmph->dst); |
| 401 | if (!orig_node) |
| 402 | goto free_skb; |
| 403 | |
| 404 | /* create a copy of the skb, if needed, to modify it. */ |
| 405 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 406 | goto put_orig_node; |
| 407 | |
| 408 | icmph = (struct batadv_icmp_header *)skb->data; |
| 409 | |
| 410 | /* decrement ttl */ |
| 411 | icmph->ttl--; |
| 412 | |
| 413 | /* route it */ |
| 414 | res = batadv_send_skb_to_orig(skb, orig_node, recv_if); |
| 415 | if (res == NET_XMIT_SUCCESS) |
| 416 | ret = NET_RX_SUCCESS; |
| 417 | |
| 418 | /* skb was consumed */ |
| 419 | skb = NULL; |
| 420 | |
| 421 | put_orig_node: |
| 422 | batadv_orig_node_put(orig_node); |
| 423 | free_skb: |
| 424 | kfree_skb(skb); |
| 425 | |
| 426 | return ret; |
| 427 | } |
| 428 | |
| 429 | /** |
| 430 | * batadv_check_unicast_packet() - Check for malformed unicast packets |
| 431 | * @bat_priv: the bat priv with all the soft interface information |
| 432 | * @skb: packet to check |
| 433 | * @hdr_size: size of header to pull |
| 434 | * |
| 435 | * Checks for short header and bad addresses in the given packet. |
| 436 | * |
| 437 | * Return: negative value when check fails and 0 otherwise. The negative value |
| 438 | * depends on the reason: -ENODATA for bad header, -EBADR for broadcast |
| 439 | * destination or source, and -EREMOTE for non-local (other host) destination. |
| 440 | */ |
| 441 | static int batadv_check_unicast_packet(struct batadv_priv *bat_priv, |
| 442 | struct sk_buff *skb, int hdr_size) |
| 443 | { |
| 444 | struct ethhdr *ethhdr; |
| 445 | |
| 446 | /* drop packet if it has not necessary minimum size */ |
| 447 | if (unlikely(!pskb_may_pull(skb, hdr_size))) |
| 448 | return -ENODATA; |
| 449 | |
| 450 | ethhdr = eth_hdr(skb); |
| 451 | |
| 452 | /* packet with unicast indication but non-unicast recipient */ |
| 453 | if (!is_valid_ether_addr(ethhdr->h_dest)) |
| 454 | return -EBADR; |
| 455 | |
| 456 | /* packet with broadcast/multicast sender address */ |
| 457 | if (is_multicast_ether_addr(ethhdr->h_source)) |
| 458 | return -EBADR; |
| 459 | |
| 460 | /* not for me */ |
| 461 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
| 462 | return -EREMOTE; |
| 463 | |
| 464 | return 0; |
| 465 | } |
| 466 | |
| 467 | /** |
| 468 | * batadv_last_bonding_get() - Get last_bonding_candidate of orig_node |
| 469 | * @orig_node: originator node whose last bonding candidate should be retrieved |
| 470 | * |
| 471 | * Return: last bonding candidate of router or NULL if not found |
| 472 | * |
| 473 | * The object is returned with refcounter increased by 1. |
| 474 | */ |
| 475 | static struct batadv_orig_ifinfo * |
| 476 | batadv_last_bonding_get(struct batadv_orig_node *orig_node) |
| 477 | { |
| 478 | struct batadv_orig_ifinfo *last_bonding_candidate; |
| 479 | |
| 480 | spin_lock_bh(&orig_node->neigh_list_lock); |
| 481 | last_bonding_candidate = orig_node->last_bonding_candidate; |
| 482 | |
| 483 | if (last_bonding_candidate) |
| 484 | kref_get(&last_bonding_candidate->refcount); |
| 485 | spin_unlock_bh(&orig_node->neigh_list_lock); |
| 486 | |
| 487 | return last_bonding_candidate; |
| 488 | } |
| 489 | |
| 490 | /** |
| 491 | * batadv_last_bonding_replace() - Replace last_bonding_candidate of orig_node |
| 492 | * @orig_node: originator node whose bonding candidates should be replaced |
| 493 | * @new_candidate: new bonding candidate or NULL |
| 494 | */ |
| 495 | static void |
| 496 | batadv_last_bonding_replace(struct batadv_orig_node *orig_node, |
| 497 | struct batadv_orig_ifinfo *new_candidate) |
| 498 | { |
| 499 | struct batadv_orig_ifinfo *old_candidate; |
| 500 | |
| 501 | spin_lock_bh(&orig_node->neigh_list_lock); |
| 502 | old_candidate = orig_node->last_bonding_candidate; |
| 503 | |
| 504 | if (new_candidate) |
| 505 | kref_get(&new_candidate->refcount); |
| 506 | orig_node->last_bonding_candidate = new_candidate; |
| 507 | spin_unlock_bh(&orig_node->neigh_list_lock); |
| 508 | |
| 509 | batadv_orig_ifinfo_put(old_candidate); |
| 510 | } |
| 511 | |
| 512 | /** |
| 513 | * batadv_find_router() - find a suitable router for this originator |
| 514 | * @bat_priv: the bat priv with all the soft interface information |
| 515 | * @orig_node: the destination node |
| 516 | * @recv_if: pointer to interface this packet was received on |
| 517 | * |
| 518 | * Return: the router which should be used for this orig_node on |
| 519 | * this interface, or NULL if not available. |
| 520 | */ |
| 521 | struct batadv_neigh_node * |
| 522 | batadv_find_router(struct batadv_priv *bat_priv, |
| 523 | struct batadv_orig_node *orig_node, |
| 524 | struct batadv_hard_iface *recv_if) |
| 525 | { |
| 526 | struct batadv_algo_ops *bao = bat_priv->algo_ops; |
| 527 | struct batadv_neigh_node *first_candidate_router = NULL; |
| 528 | struct batadv_neigh_node *next_candidate_router = NULL; |
| 529 | struct batadv_neigh_node *router, *cand_router = NULL; |
| 530 | struct batadv_neigh_node *last_cand_router = NULL; |
| 531 | struct batadv_orig_ifinfo *cand, *first_candidate = NULL; |
| 532 | struct batadv_orig_ifinfo *next_candidate = NULL; |
| 533 | struct batadv_orig_ifinfo *last_candidate; |
| 534 | bool last_candidate_found = false; |
| 535 | |
| 536 | if (!orig_node) |
| 537 | return NULL; |
| 538 | |
| 539 | router = batadv_orig_router_get(orig_node, recv_if); |
| 540 | |
| 541 | if (!router) |
| 542 | return router; |
| 543 | |
| 544 | /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop) |
| 545 | * and if activated. |
| 546 | */ |
| 547 | if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding))) |
| 548 | return router; |
| 549 | |
| 550 | /* bonding: loop through the list of possible routers found |
| 551 | * for the various outgoing interfaces and find a candidate after |
| 552 | * the last chosen bonding candidate (next_candidate). If no such |
| 553 | * router is found, use the first candidate found (the previously |
| 554 | * chosen bonding candidate might have been the last one in the list). |
| 555 | * If this can't be found either, return the previously chosen |
| 556 | * router - obviously there are no other candidates. |
| 557 | */ |
| 558 | rcu_read_lock(); |
| 559 | last_candidate = batadv_last_bonding_get(orig_node); |
| 560 | if (last_candidate) |
| 561 | last_cand_router = rcu_dereference(last_candidate->router); |
| 562 | |
| 563 | hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) { |
| 564 | /* acquire some structures and references ... */ |
| 565 | if (!kref_get_unless_zero(&cand->refcount)) |
| 566 | continue; |
| 567 | |
| 568 | cand_router = rcu_dereference(cand->router); |
| 569 | if (!cand_router) |
| 570 | goto next; |
| 571 | |
| 572 | if (!kref_get_unless_zero(&cand_router->refcount)) { |
| 573 | cand_router = NULL; |
| 574 | goto next; |
| 575 | } |
| 576 | |
| 577 | /* alternative candidate should be good enough to be |
| 578 | * considered |
| 579 | */ |
| 580 | if (!bao->neigh.is_similar_or_better(cand_router, |
| 581 | cand->if_outgoing, router, |
| 582 | recv_if)) |
| 583 | goto next; |
| 584 | |
| 585 | /* don't use the same router twice */ |
| 586 | if (last_cand_router == cand_router) |
| 587 | goto next; |
| 588 | |
| 589 | /* mark the first possible candidate */ |
| 590 | if (!first_candidate) { |
| 591 | kref_get(&cand_router->refcount); |
| 592 | kref_get(&cand->refcount); |
| 593 | first_candidate = cand; |
| 594 | first_candidate_router = cand_router; |
| 595 | } |
| 596 | |
| 597 | /* check if the loop has already passed the previously selected |
| 598 | * candidate ... this function should select the next candidate |
| 599 | * AFTER the previously used bonding candidate. |
| 600 | */ |
| 601 | if (!last_candidate || last_candidate_found) { |
| 602 | next_candidate = cand; |
| 603 | next_candidate_router = cand_router; |
| 604 | break; |
| 605 | } |
| 606 | |
| 607 | if (last_candidate == cand) |
| 608 | last_candidate_found = true; |
| 609 | next: |
| 610 | /* free references */ |
| 611 | if (cand_router) { |
| 612 | batadv_neigh_node_put(cand_router); |
| 613 | cand_router = NULL; |
| 614 | } |
| 615 | batadv_orig_ifinfo_put(cand); |
| 616 | } |
| 617 | rcu_read_unlock(); |
| 618 | |
| 619 | /* After finding candidates, handle the three cases: |
| 620 | * 1) there is a next candidate, use that |
| 621 | * 2) there is no next candidate, use the first of the list |
| 622 | * 3) there is no candidate at all, return the default router |
| 623 | */ |
| 624 | if (next_candidate) { |
| 625 | batadv_neigh_node_put(router); |
| 626 | |
| 627 | kref_get(&next_candidate_router->refcount); |
| 628 | router = next_candidate_router; |
| 629 | batadv_last_bonding_replace(orig_node, next_candidate); |
| 630 | } else if (first_candidate) { |
| 631 | batadv_neigh_node_put(router); |
| 632 | |
| 633 | kref_get(&first_candidate_router->refcount); |
| 634 | router = first_candidate_router; |
| 635 | batadv_last_bonding_replace(orig_node, first_candidate); |
| 636 | } else { |
| 637 | batadv_last_bonding_replace(orig_node, NULL); |
| 638 | } |
| 639 | |
| 640 | /* cleanup of candidates */ |
| 641 | if (first_candidate) { |
| 642 | batadv_neigh_node_put(first_candidate_router); |
| 643 | batadv_orig_ifinfo_put(first_candidate); |
| 644 | } |
| 645 | |
| 646 | if (next_candidate) { |
| 647 | batadv_neigh_node_put(next_candidate_router); |
| 648 | batadv_orig_ifinfo_put(next_candidate); |
| 649 | } |
| 650 | |
| 651 | batadv_orig_ifinfo_put(last_candidate); |
| 652 | |
| 653 | return router; |
| 654 | } |
| 655 | |
| 656 | static int batadv_route_unicast_packet(struct sk_buff *skb, |
| 657 | struct batadv_hard_iface *recv_if) |
| 658 | { |
| 659 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 660 | struct batadv_orig_node *orig_node = NULL; |
| 661 | struct batadv_unicast_packet *unicast_packet; |
| 662 | struct ethhdr *ethhdr = eth_hdr(skb); |
| 663 | int res, hdr_len, ret = NET_RX_DROP; |
| 664 | unsigned int len; |
| 665 | |
| 666 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 667 | |
| 668 | /* TTL exceeded */ |
| 669 | if (unicast_packet->ttl < 2) { |
| 670 | pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", |
| 671 | ethhdr->h_source, unicast_packet->dest); |
| 672 | goto free_skb; |
| 673 | } |
| 674 | |
| 675 | /* get routing information */ |
| 676 | orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); |
| 677 | |
| 678 | if (!orig_node) |
| 679 | goto free_skb; |
| 680 | |
| 681 | /* create a copy of the skb, if needed, to modify it. */ |
| 682 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 683 | goto put_orig_node; |
| 684 | |
| 685 | /* decrement ttl */ |
| 686 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 687 | unicast_packet->ttl--; |
| 688 | |
| 689 | switch (unicast_packet->packet_type) { |
| 690 | case BATADV_UNICAST_4ADDR: |
| 691 | hdr_len = sizeof(struct batadv_unicast_4addr_packet); |
| 692 | break; |
| 693 | case BATADV_UNICAST: |
| 694 | hdr_len = sizeof(struct batadv_unicast_packet); |
| 695 | break; |
| 696 | default: |
| 697 | /* other packet types not supported - yet */ |
| 698 | hdr_len = -1; |
| 699 | break; |
| 700 | } |
| 701 | |
| 702 | if (hdr_len > 0) |
| 703 | batadv_skb_set_priority(skb, hdr_len); |
| 704 | |
| 705 | len = skb->len; |
| 706 | res = batadv_send_skb_to_orig(skb, orig_node, recv_if); |
| 707 | |
| 708 | /* translate transmit result into receive result */ |
| 709 | if (res == NET_XMIT_SUCCESS) { |
| 710 | ret = NET_RX_SUCCESS; |
| 711 | /* skb was transmitted and consumed */ |
| 712 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); |
| 713 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, |
| 714 | len + ETH_HLEN); |
| 715 | } |
| 716 | |
| 717 | /* skb was consumed */ |
| 718 | skb = NULL; |
| 719 | |
| 720 | put_orig_node: |
| 721 | batadv_orig_node_put(orig_node); |
| 722 | free_skb: |
| 723 | kfree_skb(skb); |
| 724 | |
| 725 | return ret; |
| 726 | } |
| 727 | |
| 728 | /** |
| 729 | * batadv_reroute_unicast_packet() - update the unicast header for re-routing |
| 730 | * @bat_priv: the bat priv with all the soft interface information |
| 731 | * @skb: unicast packet to process |
| 732 | * @unicast_packet: the unicast header to be updated |
| 733 | * @dst_addr: the payload destination |
| 734 | * @vid: VLAN identifier |
| 735 | * |
| 736 | * Search the translation table for dst_addr and update the unicast header with |
| 737 | * the new corresponding information (originator address where the destination |
| 738 | * client currently is and its known TTVN) |
| 739 | * |
| 740 | * Return: true if the packet header has been updated, false otherwise |
| 741 | */ |
| 742 | static bool |
| 743 | batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
| 744 | struct batadv_unicast_packet *unicast_packet, |
| 745 | u8 *dst_addr, unsigned short vid) |
| 746 | { |
| 747 | struct batadv_orig_node *orig_node = NULL; |
| 748 | struct batadv_hard_iface *primary_if = NULL; |
| 749 | bool ret = false; |
| 750 | const u8 *orig_addr; |
| 751 | u8 orig_ttvn; |
| 752 | |
| 753 | if (batadv_is_my_client(bat_priv, dst_addr, vid)) { |
| 754 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| 755 | if (!primary_if) |
| 756 | goto out; |
| 757 | orig_addr = primary_if->net_dev->dev_addr; |
| 758 | orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn); |
| 759 | } else { |
| 760 | orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr, |
| 761 | vid); |
| 762 | if (!orig_node) |
| 763 | goto out; |
| 764 | |
| 765 | if (batadv_compare_eth(orig_node->orig, unicast_packet->dest)) |
| 766 | goto out; |
| 767 | |
| 768 | orig_addr = orig_node->orig; |
| 769 | orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn); |
| 770 | } |
| 771 | |
| 772 | /* update the packet header */ |
| 773 | skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); |
| 774 | ether_addr_copy(unicast_packet->dest, orig_addr); |
| 775 | unicast_packet->ttvn = orig_ttvn; |
| 776 | skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); |
| 777 | |
| 778 | ret = true; |
| 779 | out: |
| 780 | batadv_hardif_put(primary_if); |
| 781 | batadv_orig_node_put(orig_node); |
| 782 | |
| 783 | return ret; |
| 784 | } |
| 785 | |
| 786 | static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, |
| 787 | struct sk_buff *skb, int hdr_len) |
| 788 | { |
| 789 | struct batadv_unicast_packet *unicast_packet; |
| 790 | struct batadv_hard_iface *primary_if; |
| 791 | struct batadv_orig_node *orig_node; |
| 792 | u8 curr_ttvn, old_ttvn; |
| 793 | struct ethhdr *ethhdr; |
| 794 | unsigned short vid; |
| 795 | int is_old_ttvn; |
| 796 | |
| 797 | /* check if there is enough data before accessing it */ |
| 798 | if (!pskb_may_pull(skb, hdr_len + ETH_HLEN)) |
| 799 | return false; |
| 800 | |
| 801 | /* create a copy of the skb (in case of for re-routing) to modify it. */ |
| 802 | if (skb_cow(skb, sizeof(*unicast_packet)) < 0) |
| 803 | return false; |
| 804 | |
| 805 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 806 | vid = batadv_get_vid(skb, hdr_len); |
| 807 | ethhdr = (struct ethhdr *)(skb->data + hdr_len); |
| 808 | |
| 809 | /* do not reroute multicast frames in a unicast header */ |
| 810 | if (is_multicast_ether_addr(ethhdr->h_dest)) |
| 811 | return true; |
| 812 | |
| 813 | /* check if the destination client was served by this node and it is now |
| 814 | * roaming. In this case, it means that the node has got a ROAM_ADV |
| 815 | * message and that it knows the new destination in the mesh to re-route |
| 816 | * the packet to |
| 817 | */ |
| 818 | if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) { |
| 819 | if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, |
| 820 | ethhdr->h_dest, vid)) |
| 821 | batadv_dbg_ratelimited(BATADV_DBG_TT, |
| 822 | bat_priv, |
| 823 | "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n", |
| 824 | unicast_packet->dest, |
| 825 | ethhdr->h_dest); |
| 826 | /* at this point the mesh destination should have been |
| 827 | * substituted with the originator address found in the global |
| 828 | * table. If not, let the packet go untouched anyway because |
| 829 | * there is nothing the node can do |
| 830 | */ |
| 831 | return true; |
| 832 | } |
| 833 | |
| 834 | /* retrieve the TTVN known by this node for the packet destination. This |
| 835 | * value is used later to check if the node which sent (or re-routed |
| 836 | * last time) the packet had an updated information or not |
| 837 | */ |
| 838 | curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn); |
| 839 | if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) { |
| 840 | orig_node = batadv_orig_hash_find(bat_priv, |
| 841 | unicast_packet->dest); |
| 842 | /* if it is not possible to find the orig_node representing the |
| 843 | * destination, the packet can immediately be dropped as it will |
| 844 | * not be possible to deliver it |
| 845 | */ |
| 846 | if (!orig_node) |
| 847 | return false; |
| 848 | |
| 849 | curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn); |
| 850 | batadv_orig_node_put(orig_node); |
| 851 | } |
| 852 | |
| 853 | /* check if the TTVN contained in the packet is fresher than what the |
| 854 | * node knows |
| 855 | */ |
| 856 | is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); |
| 857 | if (!is_old_ttvn) |
| 858 | return true; |
| 859 | |
| 860 | old_ttvn = unicast_packet->ttvn; |
| 861 | /* the packet was forged based on outdated network information. Its |
| 862 | * destination can possibly be updated and forwarded towards the new |
| 863 | * target host |
| 864 | */ |
| 865 | if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, |
| 866 | ethhdr->h_dest, vid)) { |
| 867 | batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, |
| 868 | "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", |
| 869 | unicast_packet->dest, ethhdr->h_dest, |
| 870 | old_ttvn, curr_ttvn); |
| 871 | return true; |
| 872 | } |
| 873 | |
| 874 | /* the packet has not been re-routed: either the destination is |
| 875 | * currently served by this node or there is no destination at all and |
| 876 | * it is possible to drop the packet |
| 877 | */ |
| 878 | if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid)) |
| 879 | return false; |
| 880 | |
| 881 | /* update the header in order to let the packet be delivered to this |
| 882 | * node's soft interface |
| 883 | */ |
| 884 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| 885 | if (!primary_if) |
| 886 | return false; |
| 887 | |
| 888 | /* update the packet header */ |
| 889 | skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); |
| 890 | ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr); |
| 891 | unicast_packet->ttvn = curr_ttvn; |
| 892 | skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); |
| 893 | |
| 894 | batadv_hardif_put(primary_if); |
| 895 | |
| 896 | return true; |
| 897 | } |
| 898 | |
| 899 | /** |
| 900 | * batadv_recv_unhandled_unicast_packet() - receive and process packets which |
| 901 | * are in the unicast number space but not yet known to the implementation |
| 902 | * @skb: unicast tvlv packet to process |
| 903 | * @recv_if: pointer to interface this packet was received on |
| 904 | * |
| 905 | * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP |
| 906 | * otherwise. |
| 907 | */ |
| 908 | int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb, |
| 909 | struct batadv_hard_iface *recv_if) |
| 910 | { |
| 911 | struct batadv_unicast_packet *unicast_packet; |
| 912 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 913 | int check, hdr_size = sizeof(*unicast_packet); |
| 914 | |
| 915 | check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); |
| 916 | if (check < 0) |
| 917 | goto free_skb; |
| 918 | |
| 919 | /* we don't know about this type, drop it. */ |
| 920 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 921 | if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) |
| 922 | goto free_skb; |
| 923 | |
| 924 | return batadv_route_unicast_packet(skb, recv_if); |
| 925 | |
| 926 | free_skb: |
| 927 | kfree_skb(skb); |
| 928 | return NET_RX_DROP; |
| 929 | } |
| 930 | |
| 931 | /** |
| 932 | * batadv_recv_unicast_packet() - Process incoming unicast packet |
| 933 | * @skb: incoming packet buffer |
| 934 | * @recv_if: incoming hard interface |
| 935 | * |
| 936 | * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure |
| 937 | */ |
| 938 | int batadv_recv_unicast_packet(struct sk_buff *skb, |
| 939 | struct batadv_hard_iface *recv_if) |
| 940 | { |
| 941 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 942 | struct batadv_unicast_packet *unicast_packet; |
| 943 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; |
| 944 | u8 *orig_addr, *orig_addr_gw; |
| 945 | struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL; |
| 946 | int check, hdr_size = sizeof(*unicast_packet); |
| 947 | enum batadv_subtype subtype; |
| 948 | int ret = NET_RX_DROP; |
| 949 | bool is4addr, is_gw; |
| 950 | |
| 951 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 952 | is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; |
| 953 | /* the caller function should have already pulled 2 bytes */ |
| 954 | if (is4addr) |
| 955 | hdr_size = sizeof(*unicast_4addr_packet); |
| 956 | |
| 957 | /* function returns -EREMOTE for promiscuous packets */ |
| 958 | check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); |
| 959 | |
| 960 | /* Even though the packet is not for us, we might save it to use for |
| 961 | * decoding a later received coded packet |
| 962 | */ |
| 963 | if (check == -EREMOTE) |
| 964 | batadv_nc_skb_store_sniffed_unicast(bat_priv, skb); |
| 965 | |
| 966 | if (check < 0) |
| 967 | goto free_skb; |
| 968 | if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) |
| 969 | goto free_skb; |
| 970 | |
| 971 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| 972 | |
| 973 | /* packet for me */ |
| 974 | if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { |
| 975 | /* If this is a unicast packet from another backgone gw, |
| 976 | * drop it. |
| 977 | */ |
| 978 | orig_addr_gw = eth_hdr(skb)->h_source; |
| 979 | orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw); |
| 980 | if (orig_node_gw) { |
| 981 | is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw, |
| 982 | hdr_size); |
| 983 | batadv_orig_node_put(orig_node_gw); |
| 984 | if (is_gw) { |
| 985 | batadv_dbg(BATADV_DBG_BLA, bat_priv, |
| 986 | "%s(): Dropped unicast pkt received from another backbone gw %pM.\n", |
| 987 | __func__, orig_addr_gw); |
| 988 | goto free_skb; |
| 989 | } |
| 990 | } |
| 991 | |
| 992 | if (is4addr) { |
| 993 | unicast_4addr_packet = |
| 994 | (struct batadv_unicast_4addr_packet *)skb->data; |
| 995 | subtype = unicast_4addr_packet->subtype; |
| 996 | batadv_dat_inc_counter(bat_priv, subtype); |
| 997 | |
| 998 | /* Only payload data should be considered for speedy |
| 999 | * join. For example, DAT also uses unicast 4addr |
| 1000 | * types, but those packets should not be considered |
| 1001 | * for speedy join, since the clients do not actually |
| 1002 | * reside at the sending originator. |
| 1003 | */ |
| 1004 | if (subtype == BATADV_P_DATA) { |
| 1005 | orig_addr = unicast_4addr_packet->src; |
| 1006 | orig_node = batadv_orig_hash_find(bat_priv, |
| 1007 | orig_addr); |
| 1008 | } |
| 1009 | } |
| 1010 | |
| 1011 | if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, |
| 1012 | hdr_size)) |
| 1013 | goto rx_success; |
| 1014 | if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, |
| 1015 | hdr_size)) |
| 1016 | goto rx_success; |
| 1017 | |
| 1018 | batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); |
| 1019 | |
| 1020 | batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, |
| 1021 | orig_node); |
| 1022 | |
| 1023 | rx_success: |
| 1024 | batadv_orig_node_put(orig_node); |
| 1025 | |
| 1026 | return NET_RX_SUCCESS; |
| 1027 | } |
| 1028 | |
| 1029 | ret = batadv_route_unicast_packet(skb, recv_if); |
| 1030 | /* skb was consumed */ |
| 1031 | skb = NULL; |
| 1032 | |
| 1033 | free_skb: |
| 1034 | kfree_skb(skb); |
| 1035 | |
| 1036 | return ret; |
| 1037 | } |
| 1038 | |
| 1039 | /** |
| 1040 | * batadv_recv_unicast_tvlv() - receive and process unicast tvlv packets |
| 1041 | * @skb: unicast tvlv packet to process |
| 1042 | * @recv_if: pointer to interface this packet was received on |
| 1043 | * |
| 1044 | * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP |
| 1045 | * otherwise. |
| 1046 | */ |
| 1047 | int batadv_recv_unicast_tvlv(struct sk_buff *skb, |
| 1048 | struct batadv_hard_iface *recv_if) |
| 1049 | { |
| 1050 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 1051 | struct batadv_unicast_tvlv_packet *unicast_tvlv_packet; |
| 1052 | unsigned char *tvlv_buff; |
| 1053 | u16 tvlv_buff_len; |
| 1054 | int hdr_size = sizeof(*unicast_tvlv_packet); |
| 1055 | int ret = NET_RX_DROP; |
| 1056 | |
| 1057 | if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) |
| 1058 | goto free_skb; |
| 1059 | |
| 1060 | /* the header is likely to be modified while forwarding */ |
| 1061 | if (skb_cow(skb, hdr_size) < 0) |
| 1062 | goto free_skb; |
| 1063 | |
| 1064 | /* packet needs to be linearized to access the tvlv content */ |
| 1065 | if (skb_linearize(skb) < 0) |
| 1066 | goto free_skb; |
| 1067 | |
| 1068 | unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data; |
| 1069 | |
| 1070 | tvlv_buff = (unsigned char *)(skb->data + hdr_size); |
| 1071 | tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len); |
| 1072 | |
| 1073 | if (tvlv_buff_len > skb->len - hdr_size) |
| 1074 | goto free_skb; |
| 1075 | |
| 1076 | ret = batadv_tvlv_containers_process(bat_priv, BATADV_UNICAST_TVLV, |
| 1077 | NULL, skb, tvlv_buff, |
| 1078 | tvlv_buff_len); |
| 1079 | |
| 1080 | if (ret != NET_RX_SUCCESS) { |
| 1081 | ret = batadv_route_unicast_packet(skb, recv_if); |
| 1082 | /* skb was consumed */ |
| 1083 | skb = NULL; |
| 1084 | } |
| 1085 | |
| 1086 | free_skb: |
| 1087 | kfree_skb(skb); |
| 1088 | |
| 1089 | return ret; |
| 1090 | } |
| 1091 | |
| 1092 | /** |
| 1093 | * batadv_recv_frag_packet() - process received fragment |
| 1094 | * @skb: the received fragment |
| 1095 | * @recv_if: interface that the skb is received on |
| 1096 | * |
| 1097 | * This function does one of the three following things: 1) Forward fragment, if |
| 1098 | * the assembled packet will exceed our MTU; 2) Buffer fragment, if we still |
| 1099 | * lack further fragments; 3) Merge fragments, if we have all needed parts. |
| 1100 | * |
| 1101 | * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise. |
| 1102 | */ |
| 1103 | int batadv_recv_frag_packet(struct sk_buff *skb, |
| 1104 | struct batadv_hard_iface *recv_if) |
| 1105 | { |
| 1106 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 1107 | struct batadv_orig_node *orig_node_src = NULL; |
| 1108 | struct batadv_frag_packet *frag_packet; |
| 1109 | int ret = NET_RX_DROP; |
| 1110 | |
| 1111 | if (batadv_check_unicast_packet(bat_priv, skb, |
| 1112 | sizeof(*frag_packet)) < 0) |
| 1113 | goto free_skb; |
| 1114 | |
| 1115 | frag_packet = (struct batadv_frag_packet *)skb->data; |
| 1116 | orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig); |
| 1117 | if (!orig_node_src) |
| 1118 | goto free_skb; |
| 1119 | |
| 1120 | skb->priority = frag_packet->priority + 256; |
| 1121 | |
| 1122 | /* Route the fragment if it is not for us and too big to be merged. */ |
| 1123 | if (!batadv_is_my_mac(bat_priv, frag_packet->dest) && |
| 1124 | batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) { |
| 1125 | /* skb was consumed */ |
| 1126 | skb = NULL; |
| 1127 | ret = NET_RX_SUCCESS; |
| 1128 | goto put_orig_node; |
| 1129 | } |
| 1130 | |
| 1131 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX); |
| 1132 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len); |
| 1133 | |
| 1134 | /* Add fragment to buffer and merge if possible. */ |
| 1135 | if (!batadv_frag_skb_buffer(&skb, orig_node_src)) |
| 1136 | goto put_orig_node; |
| 1137 | |
| 1138 | /* Deliver merged packet to the appropriate handler, if it was |
| 1139 | * merged |
| 1140 | */ |
| 1141 | if (skb) { |
| 1142 | batadv_batman_skb_recv(skb, recv_if->net_dev, |
| 1143 | &recv_if->batman_adv_ptype, NULL); |
| 1144 | /* skb was consumed */ |
| 1145 | skb = NULL; |
| 1146 | } |
| 1147 | |
| 1148 | ret = NET_RX_SUCCESS; |
| 1149 | |
| 1150 | put_orig_node: |
| 1151 | batadv_orig_node_put(orig_node_src); |
| 1152 | free_skb: |
| 1153 | kfree_skb(skb); |
| 1154 | |
| 1155 | return ret; |
| 1156 | } |
| 1157 | |
| 1158 | /** |
| 1159 | * batadv_recv_bcast_packet() - Process incoming broadcast packet |
| 1160 | * @skb: incoming packet buffer |
| 1161 | * @recv_if: incoming hard interface |
| 1162 | * |
| 1163 | * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure |
| 1164 | */ |
| 1165 | int batadv_recv_bcast_packet(struct sk_buff *skb, |
| 1166 | struct batadv_hard_iface *recv_if) |
| 1167 | { |
| 1168 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 1169 | struct batadv_orig_node *orig_node = NULL; |
| 1170 | struct batadv_bcast_packet *bcast_packet; |
| 1171 | struct ethhdr *ethhdr; |
| 1172 | int hdr_size = sizeof(*bcast_packet); |
| 1173 | s32 seq_diff; |
| 1174 | u32 seqno; |
| 1175 | int ret; |
| 1176 | |
| 1177 | /* drop packet if it has not necessary minimum size */ |
| 1178 | if (unlikely(!pskb_may_pull(skb, hdr_size))) |
| 1179 | goto free_skb; |
| 1180 | |
| 1181 | ethhdr = eth_hdr(skb); |
| 1182 | |
| 1183 | /* packet with broadcast indication but unicast recipient */ |
| 1184 | if (!is_broadcast_ether_addr(ethhdr->h_dest)) |
| 1185 | goto free_skb; |
| 1186 | |
| 1187 | /* packet with broadcast/multicast sender address */ |
| 1188 | if (is_multicast_ether_addr(ethhdr->h_source)) |
| 1189 | goto free_skb; |
| 1190 | |
| 1191 | /* ignore broadcasts sent by myself */ |
| 1192 | if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) |
| 1193 | goto free_skb; |
| 1194 | |
| 1195 | bcast_packet = (struct batadv_bcast_packet *)skb->data; |
| 1196 | |
| 1197 | /* ignore broadcasts originated by myself */ |
| 1198 | if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) |
| 1199 | goto free_skb; |
| 1200 | |
| 1201 | if (bcast_packet->ttl-- < 2) |
| 1202 | goto free_skb; |
| 1203 | |
| 1204 | orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig); |
| 1205 | |
| 1206 | if (!orig_node) |
| 1207 | goto free_skb; |
| 1208 | |
| 1209 | spin_lock_bh(&orig_node->bcast_seqno_lock); |
| 1210 | |
| 1211 | seqno = ntohl(bcast_packet->seqno); |
| 1212 | /* check whether the packet is a duplicate */ |
| 1213 | if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno, |
| 1214 | seqno)) |
| 1215 | goto spin_unlock; |
| 1216 | |
| 1217 | seq_diff = seqno - orig_node->last_bcast_seqno; |
| 1218 | |
| 1219 | /* check whether the packet is old and the host just restarted. */ |
| 1220 | if (batadv_window_protected(bat_priv, seq_diff, |
| 1221 | BATADV_BCAST_MAX_AGE, |
| 1222 | &orig_node->bcast_seqno_reset, NULL)) |
| 1223 | goto spin_unlock; |
| 1224 | |
| 1225 | /* mark broadcast in flood history, update window position |
| 1226 | * if required. |
| 1227 | */ |
| 1228 | if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1)) |
| 1229 | orig_node->last_bcast_seqno = seqno; |
| 1230 | |
| 1231 | spin_unlock_bh(&orig_node->bcast_seqno_lock); |
| 1232 | |
| 1233 | /* check whether this has been sent by another originator before */ |
| 1234 | if (batadv_bla_check_bcast_duplist(bat_priv, skb)) |
| 1235 | goto free_skb; |
| 1236 | |
| 1237 | batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet)); |
| 1238 | |
| 1239 | /* rebroadcast packet */ |
| 1240 | ret = batadv_forw_bcast_packet(bat_priv, skb, 0, false); |
| 1241 | if (ret == NETDEV_TX_BUSY) |
| 1242 | goto free_skb; |
| 1243 | |
| 1244 | /* don't hand the broadcast up if it is from an originator |
| 1245 | * from the same backbone. |
| 1246 | */ |
| 1247 | if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) |
| 1248 | goto free_skb; |
| 1249 | |
| 1250 | if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) |
| 1251 | goto rx_success; |
| 1252 | if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) |
| 1253 | goto rx_success; |
| 1254 | |
| 1255 | batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); |
| 1256 | |
| 1257 | /* broadcast for me */ |
| 1258 | batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node); |
| 1259 | |
| 1260 | rx_success: |
| 1261 | ret = NET_RX_SUCCESS; |
| 1262 | goto out; |
| 1263 | |
| 1264 | spin_unlock: |
| 1265 | spin_unlock_bh(&orig_node->bcast_seqno_lock); |
| 1266 | free_skb: |
| 1267 | kfree_skb(skb); |
| 1268 | ret = NET_RX_DROP; |
| 1269 | out: |
| 1270 | batadv_orig_node_put(orig_node); |
| 1271 | return ret; |
| 1272 | } |
| 1273 | |
| 1274 | #ifdef CONFIG_BATMAN_ADV_MCAST |
| 1275 | /** |
| 1276 | * batadv_recv_mcast_packet() - process received batman-adv multicast packet |
| 1277 | * @skb: the received batman-adv multicast packet |
| 1278 | * @recv_if: interface that the skb is received on |
| 1279 | * |
| 1280 | * Parses the given, received batman-adv multicast packet. Depending on the |
| 1281 | * contents of its TVLV forwards it and/or decapsulates it to hand it to the |
| 1282 | * soft interface. |
| 1283 | * |
| 1284 | * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise. |
| 1285 | */ |
| 1286 | int batadv_recv_mcast_packet(struct sk_buff *skb, |
| 1287 | struct batadv_hard_iface *recv_if) |
| 1288 | { |
| 1289 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
| 1290 | struct batadv_mcast_packet *mcast_packet; |
| 1291 | int hdr_size = sizeof(*mcast_packet); |
| 1292 | unsigned char *tvlv_buff; |
| 1293 | int ret = NET_RX_DROP; |
| 1294 | u16 tvlv_buff_len; |
| 1295 | |
| 1296 | if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) |
| 1297 | goto free_skb; |
| 1298 | |
| 1299 | /* create a copy of the skb, if needed, to modify it. */ |
| 1300 | if (skb_cow(skb, ETH_HLEN) < 0) |
| 1301 | goto free_skb; |
| 1302 | |
| 1303 | /* packet needs to be linearized to access the tvlv content */ |
| 1304 | if (skb_linearize(skb) < 0) |
| 1305 | goto free_skb; |
| 1306 | |
| 1307 | mcast_packet = (struct batadv_mcast_packet *)skb->data; |
| 1308 | if (mcast_packet->ttl-- < 2) |
| 1309 | goto free_skb; |
| 1310 | |
| 1311 | tvlv_buff = (unsigned char *)(skb->data + hdr_size); |
| 1312 | tvlv_buff_len = ntohs(mcast_packet->tvlv_len); |
| 1313 | |
| 1314 | if (tvlv_buff_len > skb->len - hdr_size) |
| 1315 | goto free_skb; |
| 1316 | |
| 1317 | ret = batadv_tvlv_containers_process(bat_priv, BATADV_MCAST, NULL, skb, |
| 1318 | tvlv_buff, tvlv_buff_len); |
| 1319 | if (ret >= 0) { |
| 1320 | batadv_inc_counter(bat_priv, BATADV_CNT_MCAST_RX); |
| 1321 | batadv_add_counter(bat_priv, BATADV_CNT_MCAST_RX_BYTES, |
| 1322 | skb->len + ETH_HLEN); |
| 1323 | } |
| 1324 | |
| 1325 | hdr_size += tvlv_buff_len; |
| 1326 | |
| 1327 | if (ret == NET_RX_SUCCESS && (skb->len - hdr_size >= ETH_HLEN)) { |
| 1328 | batadv_inc_counter(bat_priv, BATADV_CNT_MCAST_RX_LOCAL); |
| 1329 | batadv_add_counter(bat_priv, BATADV_CNT_MCAST_RX_LOCAL_BYTES, |
| 1330 | skb->len - hdr_size); |
| 1331 | |
| 1332 | batadv_interface_rx(bat_priv->soft_iface, skb, hdr_size, NULL); |
| 1333 | /* skb was consumed */ |
| 1334 | skb = NULL; |
| 1335 | } |
| 1336 | |
| 1337 | free_skb: |
| 1338 | kfree_skb(skb); |
| 1339 | |
| 1340 | return ret; |
| 1341 | } |
| 1342 | #endif /* CONFIG_BATMAN_ADV_MCAST */ |