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