net/batman-adv/main.c

   1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include <linux/crc32c.h>
  21 #include <linux/highmem.h>
  22 #include <linux/if_vlan.h>
  23 #include <net/ip.h>
  24 #include <net/ipv6.h>
  25 #include <net/dsfield.h>
  26 #include "main.h"
  27 #include "sysfs.h"
  28 #include "debugfs.h"
  29 #include "routing.h"
  30 #include "send.h"
  31 #include "originator.h"
  32 #include "soft-interface.h"
  33 #include "icmp_socket.h"
  34 #include "translation-table.h"
  35 #include "hard-interface.h"
  36 #include "gateway_client.h"
  37 #include "bridge_loop_avoidance.h"
  38 #include "distributed-arp-table.h"
  39 #include "vis.h"
  40 #include "hash.h"
  41 #include "bat_algo.h"
  42 #include "network-coding.h"
  43
  44
  45 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  46  * list traversals just rcu-locked
  47  */
  48 struct list_head batadv_hardif_list;
  49 static int (*batadv_rx_handler[256])(struct sk_buff *,
  50                                      struct batadv_hard_iface *);
  51 char batadv_routing_algo[20] = "BATMAN_IV";
  52 static struct hlist_head batadv_algo_list;
  53
  54 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  55
  56 struct workqueue_struct *batadv_event_workqueue;
  57
  58 static void batadv_recv_handler_init(void);
  59
  60 static int __init batadv_init(void)
  61 {
  62         INIT_LIST_HEAD(&batadv_hardif_list);
  63         INIT_HLIST_HEAD(&batadv_algo_list);
  64
  65         batadv_recv_handler_init();
  66
  67         batadv_iv_init();
  68         batadv_nc_init();
  69
  70         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  71
  72         if (!batadv_event_workqueue)
  73                 return -ENOMEM;
  74
  75         batadv_socket_init();
  76         batadv_debugfs_init();
  77
  78         register_netdevice_notifier(&batadv_hard_if_notifier);
  79         rtnl_link_register(&batadv_link_ops);
  80
  81         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  82                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  83
  84         return 0;
  85 }
  86
  87 static void __exit batadv_exit(void)
  88 {
  89         batadv_debugfs_destroy();
  90         rtnl_link_unregister(&batadv_link_ops);
  91         unregister_netdevice_notifier(&batadv_hard_if_notifier);
  92         batadv_hardif_remove_interfaces();
  93
  94         flush_workqueue(batadv_event_workqueue);
  95         destroy_workqueue(batadv_event_workqueue);
  96         batadv_event_workqueue = NULL;
  97
  98         rcu_barrier();
  99 }
 100
 101 int batadv_mesh_init(struct net_device *soft_iface)
 102 {
 103         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 104         int ret;
 105
 106         spin_lock_init(&bat_priv->forw_bat_list_lock);
 107         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 108         spin_lock_init(&bat_priv->tt.changes_list_lock);
 109         spin_lock_init(&bat_priv->tt.req_list_lock);
 110         spin_lock_init(&bat_priv->tt.roam_list_lock);
 111         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 112         spin_lock_init(&bat_priv->gw.list_lock);
 113         spin_lock_init(&bat_priv->vis.hash_lock);
 114         spin_lock_init(&bat_priv->vis.list_lock);
 115
 116         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 117         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 118         INIT_HLIST_HEAD(&bat_priv->gw.list);
 119         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 120         INIT_LIST_HEAD(&bat_priv->tt.req_list);
 121         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 122
 123         ret = batadv_originator_init(bat_priv);
 124         if (ret < 0)
 125                 goto err;
 126
 127         ret = batadv_tt_init(bat_priv);
 128         if (ret < 0)
 129                 goto err;
 130
 131         batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 132                             BATADV_NULL_IFINDEX);
 133
 134         ret = batadv_vis_init(bat_priv);
 135         if (ret < 0)
 136                 goto err;
 137
 138         ret = batadv_bla_init(bat_priv);
 139         if (ret < 0)
 140                 goto err;
 141
 142         ret = batadv_dat_init(bat_priv);
 143         if (ret < 0)
 144                 goto err;
 145
 146         ret = batadv_nc_mesh_init(bat_priv);
 147         if (ret < 0)
 148                 goto err;
 149
 150         atomic_set(&bat_priv->gw.reselect, 0);
 151         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 152
 153         return 0;
 154
 155 err:
 156         batadv_mesh_free(soft_iface);
 157         return ret;
 158 }
 159
 160 void batadv_mesh_free(struct net_device *soft_iface)
 161 {
 162         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 163
 164         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 165
 166         batadv_purge_outstanding_packets(bat_priv, NULL);
 167
 168         batadv_vis_quit(bat_priv);
 169
 170         batadv_gw_node_purge(bat_priv);
 171         batadv_nc_mesh_free(bat_priv);
 172         batadv_dat_free(bat_priv);
 173         batadv_bla_free(bat_priv);
 174
 175         /* Free the TT and the originator tables only after having terminated
 176          * all the other depending components which may use these structures for
 177          * their purposes.
 178          */
 179         batadv_tt_free(bat_priv);
 180
 181         /* Since the originator table clean up routine is accessing the TT
 182          * tables as well, it has to be invoked after the TT tables have been
 183          * freed and marked as empty. This ensures that no cleanup RCU callbacks
 184          * accessing the TT data are scheduled for later execution.
 185          */
 186         batadv_originator_free(bat_priv);
 187
 188         free_percpu(bat_priv->bat_counters);
 189         bat_priv->bat_counters = NULL;
 190
 191         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 192 }
 193
 194 /**
 195  * batadv_is_my_mac - check if the given mac address belongs to any of the real
 196  * interfaces in the current mesh
 197  * @bat_priv: the bat priv with all the soft interface information
 198  * @addr: the address to check
 199  */
 200 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
 201 {
 202         const struct batadv_hard_iface *hard_iface;
 203
 204         rcu_read_lock();
 205         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 206                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 207                         continue;
 208
 209                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 210                         continue;
 211
 212                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 213                         rcu_read_unlock();
 214                         return 1;
 215                 }
 216         }
 217         rcu_read_unlock();
 218         return 0;
 219 }
 220
 221 /**
 222  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 223  *  function that requires the primary interface
 224  * @seq: debugfs table seq_file struct
 225  *
 226  * Returns primary interface if found or NULL otherwise.
 227  */
 228 struct batadv_hard_iface *
 229 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 230 {
 231         struct net_device *net_dev = (struct net_device *)seq->private;
 232         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 233         struct batadv_hard_iface *primary_if;
 234
 235         primary_if = batadv_primary_if_get_selected(bat_priv);
 236
 237         if (!primary_if) {
 238                 seq_printf(seq,
 239                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 240                            net_dev->name);
 241                 goto out;
 242         }
 243
 244         if (primary_if->if_status == BATADV_IF_ACTIVE)
 245                 goto out;
 246
 247         seq_printf(seq,
 248                    "BATMAN mesh %s disabled - primary interface not active\n",
 249                    net_dev->name);
 250         batadv_hardif_free_ref(primary_if);
 251         primary_if = NULL;
 252
 253 out:
 254         return primary_if;
 255 }
 256
 257 /**
 258  * batadv_skb_set_priority - sets skb priority according to packet content
 259  * @skb: the packet to be sent
 260  * @offset: offset to the packet content
 261  *
 262  * This function sets a value between 256 and 263 (802.1d priority), which
 263  * can be interpreted by the cfg80211 or other drivers.
 264  */
 265 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
 266 {
 267         struct iphdr ip_hdr_tmp, *ip_hdr;
 268         struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
 269         struct ethhdr ethhdr_tmp, *ethhdr;
 270         struct vlan_ethhdr *vhdr, vhdr_tmp;
 271         u32 prio;
 272
 273         /* already set, do nothing */
 274         if (skb->priority >= 256 && skb->priority <= 263)
 275                 return;
 276
 277         ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
 278         if (!ethhdr)
 279                 return;
 280
 281         switch (ethhdr->h_proto) {
 282         case htons(ETH_P_8021Q):
 283                 vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
 284                                           sizeof(*vhdr), &vhdr_tmp);
 285                 if (!vhdr)
 286                         return;
 287                 prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
 288                 prio = prio >> VLAN_PRIO_SHIFT;
 289                 break;
 290         case htons(ETH_P_IP):
 291                 ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
 292                                             sizeof(*ip_hdr), &ip_hdr_tmp);
 293                 if (!ip_hdr)
 294                         return;
 295                 prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
 296                 break;
 297         case htons(ETH_P_IPV6):
 298                 ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
 299                                              sizeof(*ip6_hdr), &ip6_hdr_tmp);
 300                 if (!ip6_hdr)
 301                         return;
 302                 prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
 303                 break;
 304         default:
 305                 return;
 306         }
 307
 308         skb->priority = prio + 256;
 309 }
 310
 311 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 312                                         struct batadv_hard_iface *recv_if)
 313 {
 314         return NET_RX_DROP;
 315 }
 316
 317 /* incoming packets with the batman ethertype received on any active hard
 318  * interface
 319  */
 320 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 321                            struct packet_type *ptype,
 322                            struct net_device *orig_dev)
 323 {
 324         struct batadv_priv *bat_priv;
 325         struct batadv_ogm_packet *batadv_ogm_packet;
 326         struct batadv_hard_iface *hard_iface;
 327         uint8_t idx;
 328         int ret;
 329
 330         hard_iface = container_of(ptype, struct batadv_hard_iface,
 331                                   batman_adv_ptype);
 332         skb = skb_share_check(skb, GFP_ATOMIC);
 333
 334         /* skb was released by skb_share_check() */
 335         if (!skb)
 336                 goto err_out;
 337
 338         /* packet should hold at least type and version */
 339         if (unlikely(!pskb_may_pull(skb, 2)))
 340                 goto err_free;
 341
 342         /* expect a valid ethernet header here. */
 343         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 344                 goto err_free;
 345
 346         if (!hard_iface->soft_iface)
 347                 goto err_free;
 348
 349         bat_priv = netdev_priv(hard_iface->soft_iface);
 350
 351         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 352                 goto err_free;
 353
 354         /* discard frames on not active interfaces */
 355         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 356                 goto err_free;
 357
 358         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 359
 360         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 361                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 362                            "Drop packet: incompatible batman version (%i)\n",
 363                            batadv_ogm_packet->header.version);
 364                 goto err_free;
 365         }
 366
 367         /* all receive handlers return whether they received or reused
 368          * the supplied skb. if not, we have to free the skb.
 369          */
 370         idx = batadv_ogm_packet->header.packet_type;
 371         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 372
 373         if (ret == NET_RX_DROP)
 374                 kfree_skb(skb);
 375
 376         /* return NET_RX_SUCCESS in any case as we
 377          * most probably dropped the packet for
 378          * routing-logical reasons.
 379          */
 380         return NET_RX_SUCCESS;
 381
 382 err_free:
 383         kfree_skb(skb);
 384 err_out:
 385         return NET_RX_DROP;
 386 }
 387
 388 static void batadv_recv_handler_init(void)
 389 {
 390         int i;
 391
 392         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 393                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 394
 395         /* batman icmp packet */
 396         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 397         /* unicast with 4 addresses packet */
 398         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 399         /* unicast packet */
 400         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 401         /* fragmented unicast packet */
 402         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 403         /* broadcast packet */
 404         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 405         /* vis packet */
 406         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 407         /* Translation table query (request or response) */
 408         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 409         /* Roaming advertisement */
 410         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 411 }
 412
 413 int
 414 batadv_recv_handler_register(uint8_t packet_type,
 415                              int (*recv_handler)(struct sk_buff *,
 416                                                  struct batadv_hard_iface *))
 417 {
 418         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 419                 return -EBUSY;
 420
 421         batadv_rx_handler[packet_type] = recv_handler;
 422         return 0;
 423 }
 424
 425 void batadv_recv_handler_unregister(uint8_t packet_type)
 426 {
 427         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 428 }
 429
 430 static struct batadv_algo_ops *batadv_algo_get(char *name)
 431 {
 432         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 433
 434         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 435                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 436                         continue;
 437
 438                 bat_algo_ops = bat_algo_ops_tmp;
 439                 break;
 440         }
 441
 442         return bat_algo_ops;
 443 }
 444
 445 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 446 {
 447         struct batadv_algo_ops *bat_algo_ops_tmp;
 448         int ret;
 449
 450         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 451         if (bat_algo_ops_tmp) {
 452                 pr_info("Trying to register already registered routing algorithm: %s\n",
 453                         bat_algo_ops->name);
 454                 ret = -EEXIST;
 455                 goto out;
 456         }
 457
 458         /* all algorithms must implement all ops (for now) */
 459         if (!bat_algo_ops->bat_iface_enable ||
 460             !bat_algo_ops->bat_iface_disable ||
 461             !bat_algo_ops->bat_iface_update_mac ||
 462             !bat_algo_ops->bat_primary_iface_set ||
 463             !bat_algo_ops->bat_ogm_schedule ||
 464             !bat_algo_ops->bat_ogm_emit) {
 465                 pr_info("Routing algo '%s' does not implement required ops\n",
 466                         bat_algo_ops->name);
 467                 ret = -EINVAL;
 468                 goto out;
 469         }
 470
 471         INIT_HLIST_NODE(&bat_algo_ops->list);
 472         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 473         ret = 0;
 474
 475 out:
 476         return ret;
 477 }
 478
 479 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 480 {
 481         struct batadv_algo_ops *bat_algo_ops;
 482         int ret = -EINVAL;
 483
 484         bat_algo_ops = batadv_algo_get(name);
 485         if (!bat_algo_ops)
 486                 goto out;
 487
 488         bat_priv->bat_algo_ops = bat_algo_ops;
 489         ret = 0;
 490
 491 out:
 492         return ret;
 493 }
 494
 495 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 496 {
 497         struct batadv_algo_ops *bat_algo_ops;
 498
 499         seq_puts(seq, "Available routing algorithms:\n");
 500
 501         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 502                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 503         }
 504
 505         return 0;
 506 }
 507
 508 /**
 509  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 510  *  the header
 511  * @skb: skb pointing to fragmented socket buffers
 512  * @payload_ptr: Pointer to position inside the head buffer of the skb
 513  *  marking the start of the data to be CRC'ed
 514  *
 515  * payload_ptr must always point to an address in the skb head buffer and not to
 516  * a fragment.
 517  */
 518 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 519 {
 520         u32 crc = 0;
 521         unsigned int from;
 522         unsigned int to = skb->len;
 523         struct skb_seq_state st;
 524         const u8 *data;
 525         unsigned int len;
 526         unsigned int consumed = 0;
 527
 528         from = (unsigned int)(payload_ptr - skb->data);
 529
 530         skb_prepare_seq_read(skb, from, to, &st);
 531         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 532                 crc = crc32c(crc, data, len);
 533                 consumed += len;
 534         }
 535
 536         return htonl(crc);
 537 }
 538
 539 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 540 {
 541         struct batadv_algo_ops *bat_algo_ops;
 542         char *algo_name = (char *)val;
 543         size_t name_len = strlen(algo_name);
 544
 545         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 546                 algo_name[name_len - 1] = '\0';
 547
 548         bat_algo_ops = batadv_algo_get(algo_name);
 549         if (!bat_algo_ops) {
 550                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 551                 return -EINVAL;
 552         }
 553
 554         return param_set_copystring(algo_name, kp);
 555 }
 556
 557 static const struct kernel_param_ops batadv_param_ops_ra = {
 558         .set = batadv_param_set_ra,
 559         .get = param_get_string,
 560 };
 561
 562 static struct kparam_string batadv_param_string_ra = {
 563         .maxlen = sizeof(batadv_routing_algo),
 564         .string = batadv_routing_algo,
 565 };
 566
 567 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 568                 0644);
 569 module_init(batadv_init);
 570 module_exit(batadv_exit);
 571
 572 MODULE_LICENSE("GPL");
 573
 574 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 575 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 576 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 577 MODULE_VERSION(BATADV_SOURCE_VERSION);