1 /* 2 * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors: 3 * 4 * Marek Lindner, Simon Wunderlich 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of version 2 of the GNU General Public 8 * License as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 * 02110-1301, USA 19 * 20 */ 21 22 #include "main.h" 23 #include "hard-interface.h" 24 #include "soft-interface.h" 25 #include "send.h" 26 #include "translation-table.h" 27 #include "routing.h" 28 #include "bat_sysfs.h" 29 #include "originator.h" 30 #include "hash.h" 31 32 #include <linux/if_arp.h> 33 34 35 static int batman_skb_recv(struct sk_buff *skb, 36 struct net_device *dev, 37 struct packet_type *ptype, 38 struct net_device *orig_dev); 39 40 void hardif_free_rcu(struct rcu_head *rcu) 41 { 42 struct hard_iface *hard_iface; 43 44 hard_iface = container_of(rcu, struct hard_iface, rcu); 45 dev_put(hard_iface->net_dev); 46 kfree(hard_iface); 47 } 48 49 struct hard_iface *hardif_get_by_netdev(const struct net_device *net_dev) 50 { 51 struct hard_iface *hard_iface; 52 53 rcu_read_lock(); 54 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 55 if (hard_iface->net_dev == net_dev && 56 atomic_inc_not_zero(&hard_iface->refcount)) 57 goto out; 58 } 59 60 hard_iface = NULL; 61 62 out: 63 rcu_read_unlock(); 64 return hard_iface; 65 } 66 67 static int is_valid_iface(const struct net_device *net_dev) 68 { 69 if (net_dev->flags & IFF_LOOPBACK) 70 return 0; 71 72 if (net_dev->type != ARPHRD_ETHER) 73 return 0; 74 75 if (net_dev->addr_len != ETH_ALEN) 76 return 0; 77 78 /* no batman over batman */ 79 if (softif_is_valid(net_dev)) 80 return 0; 81 82 /* Device is being bridged */ 83 /* if (net_dev->priv_flags & IFF_BRIDGE_PORT) 84 return 0; */ 85 86 return 1; 87 } 88 89 static struct hard_iface *hardif_get_active(const struct net_device *soft_iface) 90 { 91 struct hard_iface *hard_iface; 92 93 rcu_read_lock(); 94 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 95 if (hard_iface->soft_iface != soft_iface) 96 continue; 97 98 if (hard_iface->if_status == IF_ACTIVE && 99 atomic_inc_not_zero(&hard_iface->refcount)) 100 goto out; 101 } 102 103 hard_iface = NULL; 104 105 out: 106 rcu_read_unlock(); 107 return hard_iface; 108 } 109 110 static void primary_if_update_addr(struct bat_priv *bat_priv) 111 { 112 struct vis_packet *vis_packet; 113 struct hard_iface *primary_if; 114 115 primary_if = primary_if_get_selected(bat_priv); 116 if (!primary_if) 117 goto out; 118 119 vis_packet = (struct vis_packet *) 120 bat_priv->my_vis_info->skb_packet->data; 121 memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN); 122 memcpy(vis_packet->sender_orig, 123 primary_if->net_dev->dev_addr, ETH_ALEN); 124 125 out: 126 if (primary_if) 127 hardif_free_ref(primary_if); 128 } 129 130 static void primary_if_select(struct bat_priv *bat_priv, 131 struct hard_iface *new_hard_iface) 132 { 133 struct hard_iface *curr_hard_iface; 134 struct batman_packet *batman_packet; 135 136 ASSERT_RTNL(); 137 138 if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount)) 139 new_hard_iface = NULL; 140 141 curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1); 142 rcu_assign_pointer(bat_priv->primary_if, new_hard_iface); 143 144 if (curr_hard_iface) 145 hardif_free_ref(curr_hard_iface); 146 147 if (!new_hard_iface) 148 return; 149 150 batman_packet = (struct batman_packet *)(new_hard_iface->packet_buff); 151 batman_packet->flags = PRIMARIES_FIRST_HOP; 152 batman_packet->ttl = TTL; 153 154 primary_if_update_addr(bat_priv); 155 } 156 157 static bool hardif_is_iface_up(const struct hard_iface *hard_iface) 158 { 159 if (hard_iface->net_dev->flags & IFF_UP) 160 return true; 161 162 return false; 163 } 164 165 static void update_mac_addresses(struct hard_iface *hard_iface) 166 { 167 memcpy(((struct batman_packet *)(hard_iface->packet_buff))->orig, 168 hard_iface->net_dev->dev_addr, ETH_ALEN); 169 memcpy(((struct batman_packet *)(hard_iface->packet_buff))->prev_sender, 170 hard_iface->net_dev->dev_addr, ETH_ALEN); 171 } 172 173 static void check_known_mac_addr(const struct net_device *net_dev) 174 { 175 const struct hard_iface *hard_iface; 176 177 rcu_read_lock(); 178 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 179 if ((hard_iface->if_status != IF_ACTIVE) && 180 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 181 continue; 182 183 if (hard_iface->net_dev == net_dev) 184 continue; 185 186 if (!compare_eth(hard_iface->net_dev->dev_addr, 187 net_dev->dev_addr)) 188 continue; 189 190 pr_warning("The newly added mac address (%pM) already exists " 191 "on: %s\n", net_dev->dev_addr, 192 hard_iface->net_dev->name); 193 pr_warning("It is strongly recommended to keep mac addresses " 194 "unique to avoid problems!\n"); 195 } 196 rcu_read_unlock(); 197 } 198 199 int hardif_min_mtu(struct net_device *soft_iface) 200 { 201 const struct bat_priv *bat_priv = netdev_priv(soft_iface); 202 const struct hard_iface *hard_iface; 203 /* allow big frames if all devices are capable to do so 204 * (have MTU > 1500 + BAT_HEADER_LEN) */ 205 int min_mtu = ETH_DATA_LEN; 206 207 if (atomic_read(&bat_priv->fragmentation)) 208 goto out; 209 210 rcu_read_lock(); 211 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 212 if ((hard_iface->if_status != IF_ACTIVE) && 213 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 214 continue; 215 216 if (hard_iface->soft_iface != soft_iface) 217 continue; 218 219 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN, 220 min_mtu); 221 } 222 rcu_read_unlock(); 223 out: 224 return min_mtu; 225 } 226 227 /* adjusts the MTU if a new interface with a smaller MTU appeared. */ 228 void update_min_mtu(struct net_device *soft_iface) 229 { 230 int min_mtu; 231 232 min_mtu = hardif_min_mtu(soft_iface); 233 if (soft_iface->mtu != min_mtu) 234 soft_iface->mtu = min_mtu; 235 } 236 237 static void hardif_activate_interface(struct hard_iface *hard_iface) 238 { 239 struct bat_priv *bat_priv; 240 struct hard_iface *primary_if = NULL; 241 242 if (hard_iface->if_status != IF_INACTIVE) 243 goto out; 244 245 bat_priv = netdev_priv(hard_iface->soft_iface); 246 247 update_mac_addresses(hard_iface); 248 hard_iface->if_status = IF_TO_BE_ACTIVATED; 249 250 /** 251 * the first active interface becomes our primary interface or 252 * the next active interface after the old primay interface was removed 253 */ 254 primary_if = primary_if_get_selected(bat_priv); 255 if (!primary_if) 256 primary_if_select(bat_priv, hard_iface); 257 258 bat_info(hard_iface->soft_iface, "Interface activated: %s\n", 259 hard_iface->net_dev->name); 260 261 update_min_mtu(hard_iface->soft_iface); 262 263 out: 264 if (primary_if) 265 hardif_free_ref(primary_if); 266 } 267 268 static void hardif_deactivate_interface(struct hard_iface *hard_iface) 269 { 270 if ((hard_iface->if_status != IF_ACTIVE) && 271 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 272 return; 273 274 hard_iface->if_status = IF_INACTIVE; 275 276 bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n", 277 hard_iface->net_dev->name); 278 279 update_min_mtu(hard_iface->soft_iface); 280 } 281 282 int hardif_enable_interface(struct hard_iface *hard_iface, 283 const char *iface_name) 284 { 285 struct bat_priv *bat_priv; 286 struct batman_packet *batman_packet; 287 struct net_device *soft_iface; 288 int ret; 289 290 if (hard_iface->if_status != IF_NOT_IN_USE) 291 goto out; 292 293 if (!atomic_inc_not_zero(&hard_iface->refcount)) 294 goto out; 295 296 soft_iface = dev_get_by_name(&init_net, iface_name); 297 298 if (!soft_iface) { 299 soft_iface = softif_create(iface_name); 300 301 if (!soft_iface) { 302 ret = -ENOMEM; 303 goto err; 304 } 305 306 /* dev_get_by_name() increases the reference counter for us */ 307 dev_hold(soft_iface); 308 } 309 310 if (!softif_is_valid(soft_iface)) { 311 pr_err("Can't create batman mesh interface %s: " 312 "already exists as regular interface\n", 313 soft_iface->name); 314 dev_put(soft_iface); 315 ret = -EINVAL; 316 goto err; 317 } 318 319 hard_iface->soft_iface = soft_iface; 320 bat_priv = netdev_priv(hard_iface->soft_iface); 321 hard_iface->packet_len = BAT_PACKET_LEN; 322 hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC); 323 324 if (!hard_iface->packet_buff) { 325 bat_err(hard_iface->soft_iface, "Can't add interface packet " 326 "(%s): out of memory\n", hard_iface->net_dev->name); 327 ret = -ENOMEM; 328 goto err; 329 } 330 331 batman_packet = (struct batman_packet *)(hard_iface->packet_buff); 332 batman_packet->packet_type = BAT_PACKET; 333 batman_packet->version = COMPAT_VERSION; 334 batman_packet->flags = NO_FLAGS; 335 batman_packet->ttl = 2; 336 batman_packet->tq = TQ_MAX_VALUE; 337 batman_packet->tt_num_changes = 0; 338 batman_packet->ttvn = 0; 339 340 hard_iface->if_num = bat_priv->num_ifaces; 341 bat_priv->num_ifaces++; 342 hard_iface->if_status = IF_INACTIVE; 343 orig_hash_add_if(hard_iface, bat_priv->num_ifaces); 344 345 hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN); 346 hard_iface->batman_adv_ptype.func = batman_skb_recv; 347 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev; 348 dev_add_pack(&hard_iface->batman_adv_ptype); 349 350 atomic_set(&hard_iface->seqno, 1); 351 atomic_set(&hard_iface->frag_seqno, 1); 352 bat_info(hard_iface->soft_iface, "Adding interface: %s\n", 353 hard_iface->net_dev->name); 354 355 if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu < 356 ETH_DATA_LEN + BAT_HEADER_LEN) 357 bat_info(hard_iface->soft_iface, 358 "The MTU of interface %s is too small (%i) to handle " 359 "the transport of batman-adv packets. Packets going " 360 "over this interface will be fragmented on layer2 " 361 "which could impact the performance. Setting the MTU " 362 "to %zi would solve the problem.\n", 363 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 364 ETH_DATA_LEN + BAT_HEADER_LEN); 365 366 if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu < 367 ETH_DATA_LEN + BAT_HEADER_LEN) 368 bat_info(hard_iface->soft_iface, 369 "The MTU of interface %s is too small (%i) to handle " 370 "the transport of batman-adv packets. If you experience" 371 " problems getting traffic through try increasing the " 372 "MTU to %zi.\n", 373 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 374 ETH_DATA_LEN + BAT_HEADER_LEN); 375 376 if (hardif_is_iface_up(hard_iface)) 377 hardif_activate_interface(hard_iface); 378 else 379 bat_err(hard_iface->soft_iface, "Not using interface %s " 380 "(retrying later): interface not active\n", 381 hard_iface->net_dev->name); 382 383 /* begin scheduling originator messages on that interface */ 384 schedule_own_packet(hard_iface); 385 386 out: 387 return 0; 388 389 err: 390 hardif_free_ref(hard_iface); 391 return ret; 392 } 393 394 void hardif_disable_interface(struct hard_iface *hard_iface) 395 { 396 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 397 struct hard_iface *primary_if = NULL; 398 399 if (hard_iface->if_status == IF_ACTIVE) 400 hardif_deactivate_interface(hard_iface); 401 402 if (hard_iface->if_status != IF_INACTIVE) 403 goto out; 404 405 bat_info(hard_iface->soft_iface, "Removing interface: %s\n", 406 hard_iface->net_dev->name); 407 dev_remove_pack(&hard_iface->batman_adv_ptype); 408 409 bat_priv->num_ifaces--; 410 orig_hash_del_if(hard_iface, bat_priv->num_ifaces); 411 412 primary_if = primary_if_get_selected(bat_priv); 413 if (hard_iface == primary_if) { 414 struct hard_iface *new_if; 415 416 new_if = hardif_get_active(hard_iface->soft_iface); 417 primary_if_select(bat_priv, new_if); 418 419 if (new_if) 420 hardif_free_ref(new_if); 421 } 422 423 kfree(hard_iface->packet_buff); 424 hard_iface->packet_buff = NULL; 425 hard_iface->if_status = IF_NOT_IN_USE; 426 427 /* delete all references to this hard_iface */ 428 purge_orig_ref(bat_priv); 429 purge_outstanding_packets(bat_priv, hard_iface); 430 dev_put(hard_iface->soft_iface); 431 432 /* nobody uses this interface anymore */ 433 if (!bat_priv->num_ifaces) 434 softif_destroy(hard_iface->soft_iface); 435 436 hard_iface->soft_iface = NULL; 437 hardif_free_ref(hard_iface); 438 439 out: 440 if (primary_if) 441 hardif_free_ref(primary_if); 442 } 443 444 static struct hard_iface *hardif_add_interface(struct net_device *net_dev) 445 { 446 struct hard_iface *hard_iface; 447 int ret; 448 449 ASSERT_RTNL(); 450 451 ret = is_valid_iface(net_dev); 452 if (ret != 1) 453 goto out; 454 455 dev_hold(net_dev); 456 457 hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC); 458 if (!hard_iface) { 459 pr_err("Can't add interface (%s): out of memory\n", 460 net_dev->name); 461 goto release_dev; 462 } 463 464 ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev); 465 if (ret) 466 goto free_if; 467 468 hard_iface->if_num = -1; 469 hard_iface->net_dev = net_dev; 470 hard_iface->soft_iface = NULL; 471 hard_iface->if_status = IF_NOT_IN_USE; 472 INIT_LIST_HEAD(&hard_iface->list); 473 /* extra reference for return */ 474 atomic_set(&hard_iface->refcount, 2); 475 476 check_known_mac_addr(hard_iface->net_dev); 477 list_add_tail_rcu(&hard_iface->list, &hardif_list); 478 479 return hard_iface; 480 481 free_if: 482 kfree(hard_iface); 483 release_dev: 484 dev_put(net_dev); 485 out: 486 return NULL; 487 } 488 489 static void hardif_remove_interface(struct hard_iface *hard_iface) 490 { 491 ASSERT_RTNL(); 492 493 /* first deactivate interface */ 494 if (hard_iface->if_status != IF_NOT_IN_USE) 495 hardif_disable_interface(hard_iface); 496 497 if (hard_iface->if_status != IF_NOT_IN_USE) 498 return; 499 500 hard_iface->if_status = IF_TO_BE_REMOVED; 501 sysfs_del_hardif(&hard_iface->hardif_obj); 502 hardif_free_ref(hard_iface); 503 } 504 505 void hardif_remove_interfaces(void) 506 { 507 struct hard_iface *hard_iface, *hard_iface_tmp; 508 509 rtnl_lock(); 510 list_for_each_entry_safe(hard_iface, hard_iface_tmp, 511 &hardif_list, list) { 512 list_del_rcu(&hard_iface->list); 513 hardif_remove_interface(hard_iface); 514 } 515 rtnl_unlock(); 516 } 517 518 static int hard_if_event(struct notifier_block *this, 519 unsigned long event, void *ptr) 520 { 521 struct net_device *net_dev = ptr; 522 struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev); 523 struct hard_iface *primary_if = NULL; 524 struct bat_priv *bat_priv; 525 526 if (!hard_iface && event == NETDEV_REGISTER) 527 hard_iface = hardif_add_interface(net_dev); 528 529 if (!hard_iface) 530 goto out; 531 532 switch (event) { 533 case NETDEV_UP: 534 hardif_activate_interface(hard_iface); 535 break; 536 case NETDEV_GOING_DOWN: 537 case NETDEV_DOWN: 538 hardif_deactivate_interface(hard_iface); 539 break; 540 case NETDEV_UNREGISTER: 541 list_del_rcu(&hard_iface->list); 542 543 hardif_remove_interface(hard_iface); 544 break; 545 case NETDEV_CHANGEMTU: 546 if (hard_iface->soft_iface) 547 update_min_mtu(hard_iface->soft_iface); 548 break; 549 case NETDEV_CHANGEADDR: 550 if (hard_iface->if_status == IF_NOT_IN_USE) 551 goto hardif_put; 552 553 check_known_mac_addr(hard_iface->net_dev); 554 update_mac_addresses(hard_iface); 555 556 bat_priv = netdev_priv(hard_iface->soft_iface); 557 primary_if = primary_if_get_selected(bat_priv); 558 if (!primary_if) 559 goto hardif_put; 560 561 if (hard_iface == primary_if) 562 primary_if_update_addr(bat_priv); 563 break; 564 default: 565 break; 566 } 567 568 hardif_put: 569 hardif_free_ref(hard_iface); 570 out: 571 if (primary_if) 572 hardif_free_ref(primary_if); 573 return NOTIFY_DONE; 574 } 575 576 /* receive a packet with the batman ethertype coming on a hard 577 * interface */ 578 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, 579 struct packet_type *ptype, 580 struct net_device *orig_dev) 581 { 582 struct bat_priv *bat_priv; 583 struct batman_packet *batman_packet; 584 struct hard_iface *hard_iface; 585 int ret; 586 587 hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype); 588 skb = skb_share_check(skb, GFP_ATOMIC); 589 590 /* skb was released by skb_share_check() */ 591 if (!skb) 592 goto err_out; 593 594 /* packet should hold at least type and version */ 595 if (unlikely(!pskb_may_pull(skb, 2))) 596 goto err_free; 597 598 /* expect a valid ethernet header here. */ 599 if (unlikely(skb->mac_len != sizeof(struct ethhdr) 600 || !skb_mac_header(skb))) 601 goto err_free; 602 603 if (!hard_iface->soft_iface) 604 goto err_free; 605 606 bat_priv = netdev_priv(hard_iface->soft_iface); 607 608 if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE) 609 goto err_free; 610 611 /* discard frames on not active interfaces */ 612 if (hard_iface->if_status != IF_ACTIVE) 613 goto err_free; 614 615 batman_packet = (struct batman_packet *)skb->data; 616 617 if (batman_packet->version != COMPAT_VERSION) { 618 bat_dbg(DBG_BATMAN, bat_priv, 619 "Drop packet: incompatible batman version (%i)\n", 620 batman_packet->version); 621 goto err_free; 622 } 623 624 /* all receive handlers return whether they received or reused 625 * the supplied skb. if not, we have to free the skb. */ 626 627 switch (batman_packet->packet_type) { 628 /* batman originator packet */ 629 case BAT_PACKET: 630 ret = recv_bat_packet(skb, hard_iface); 631 break; 632 633 /* batman icmp packet */ 634 case BAT_ICMP: 635 ret = recv_icmp_packet(skb, hard_iface); 636 break; 637 638 /* unicast packet */ 639 case BAT_UNICAST: 640 ret = recv_unicast_packet(skb, hard_iface); 641 break; 642 643 /* fragmented unicast packet */ 644 case BAT_UNICAST_FRAG: 645 ret = recv_ucast_frag_packet(skb, hard_iface); 646 break; 647 648 /* broadcast packet */ 649 case BAT_BCAST: 650 ret = recv_bcast_packet(skb, hard_iface); 651 break; 652 653 /* vis packet */ 654 case BAT_VIS: 655 ret = recv_vis_packet(skb, hard_iface); 656 break; 657 /* Translation table query (request or response) */ 658 case BAT_TT_QUERY: 659 ret = recv_tt_query(skb, hard_iface); 660 break; 661 /* Roaming advertisement */ 662 case BAT_ROAM_ADV: 663 ret = recv_roam_adv(skb, hard_iface); 664 break; 665 default: 666 ret = NET_RX_DROP; 667 } 668 669 if (ret == NET_RX_DROP) 670 kfree_skb(skb); 671 672 /* return NET_RX_SUCCESS in any case as we 673 * most probably dropped the packet for 674 * routing-logical reasons. */ 675 676 return NET_RX_SUCCESS; 677 678 err_free: 679 kfree_skb(skb); 680 err_out: 681 return NET_RX_DROP; 682 } 683 684 struct notifier_block hard_if_notifier = { 685 .notifier_call = hard_if_event, 686 }; 687