net/batman-adv/vis.c

   1 /* Copyright (C) 2008-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * 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 "main.h"
  21 #include "send.h"
  22 #include "translation-table.h"
  23 #include "vis.h"
  24 #include "soft-interface.h"
  25 #include "hard-interface.h"
  26 #include "hash.h"
  27 #include "originator.h"
  28
  29 #define BATADV_MAX_VIS_PACKET_SIZE 1000
  30
  31 /* hash class keys */
  32 static struct lock_class_key batadv_vis_hash_lock_class_key;
  33
  34 /* free the info */
  35 static void batadv_free_info(struct kref *ref)
  36 {
  37         struct batadv_vis_info *info;
  38         struct batadv_priv *bat_priv;
  39         struct batadv_vis_recvlist_node *entry, *tmp;
  40
  41         info = container_of(ref, struct batadv_vis_info, refcount);
  42         bat_priv = info->bat_priv;
  43
  44         list_del_init(&info->send_list);
  45         spin_lock_bh(&bat_priv->vis.list_lock);
  46         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  47                 list_del(&entry->list);
  48                 kfree(entry);
  49         }
  50
  51         spin_unlock_bh(&bat_priv->vis.list_lock);
  52         kfree_skb(info->skb_packet);
  53         kfree(info);
  54 }
  55
  56 /* Compare two vis packets, used by the hashing algorithm */
  57 static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
  58 {
  59         const struct batadv_vis_info *d1, *d2;
  60         const struct batadv_vis_packet *p1, *p2;
  61
  62         d1 = container_of(node, struct batadv_vis_info, hash_entry);
  63         d2 = data2;
  64         p1 = (struct batadv_vis_packet *)d1->skb_packet->data;
  65         p2 = (struct batadv_vis_packet *)d2->skb_packet->data;
  66         return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
  67 }
  68
  69 /* hash function to choose an entry in a hash table of given size
  70  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  71  */
  72 static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
  73 {
  74         const struct batadv_vis_info *vis_info = data;
  75         const struct batadv_vis_packet *packet;
  76         const unsigned char *key;
  77         uint32_t hash = 0;
  78         size_t i;
  79
  80         packet = (struct batadv_vis_packet *)vis_info->skb_packet->data;
  81         key = packet->vis_orig;
  82         for (i = 0; i < ETH_ALEN; i++) {
  83                 hash += key[i];
  84                 hash += (hash << 10);
  85                 hash ^= (hash >> 6);
  86         }
  87
  88         hash += (hash << 3);
  89         hash ^= (hash >> 11);
  90         hash += (hash << 15);
  91
  92         return hash % size;
  93 }
  94
  95 static struct batadv_vis_info *
  96 batadv_vis_hash_find(struct batadv_priv *bat_priv, const void *data)
  97 {
  98         struct batadv_hashtable *hash = bat_priv->vis.hash;
  99         struct hlist_head *head;
 100         struct hlist_node *node;
 101         struct batadv_vis_info *vis_info, *vis_info_tmp = NULL;
 102         uint32_t index;
 103
 104         if (!hash)
 105                 return NULL;
 106
 107         index = batadv_vis_info_choose(data, hash->size);
 108         head = &hash->table[index];
 109
 110         rcu_read_lock();
 111         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 112                 if (!batadv_vis_info_cmp(node, data))
 113                         continue;
 114
 115                 vis_info_tmp = vis_info;
 116                 break;
 117         }
 118         rcu_read_unlock();
 119
 120         return vis_info_tmp;
 121 }
 122
 123 /* insert interface to the list of interfaces of one originator, if it
 124  * does not already exist in the list
 125  */
 126 static void batadv_vis_data_insert_interface(const uint8_t *interface,
 127                                              struct hlist_head *if_list,
 128                                              bool primary)
 129 {
 130         struct batadv_vis_if_list_entry *entry;
 131         struct hlist_node *pos;
 132
 133         hlist_for_each_entry(entry, pos, if_list, list) {
 134                 if (batadv_compare_eth(entry->addr, interface))
 135                         return;
 136         }
 137
 138         /* it's a new address, add it to the list */
 139         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 140         if (!entry)
 141                 return;
 142         memcpy(entry->addr, interface, ETH_ALEN);
 143         entry->primary = primary;
 144         hlist_add_head(&entry->list, if_list);
 145 }
 146
 147 static void batadv_vis_data_read_prim_sec(struct seq_file *seq,
 148                                           const struct hlist_head *if_list)
 149 {
 150         struct batadv_vis_if_list_entry *entry;
 151         struct hlist_node *pos;
 152
 153         hlist_for_each_entry(entry, pos, if_list, list) {
 154                 if (entry->primary)
 155                         seq_printf(seq, "PRIMARY, ");
 156                 else
 157                         seq_printf(seq,  "SEC %pM, ", entry->addr);
 158         }
 159 }
 160
 161 /* read an entry  */
 162 static ssize_t
 163 batadv_vis_data_read_entry(struct seq_file *seq,
 164                            const struct batadv_vis_info_entry *entry,
 165                            const uint8_t *src, bool primary)
 166 {
 167         if (primary && entry->quality == 0)
 168                 return seq_printf(seq, "TT %pM, ", entry->dest);
 169         else if (batadv_compare_eth(entry->src, src))
 170                 return seq_printf(seq, "TQ %pM %d, ", entry->dest,
 171                                   entry->quality);
 172
 173         return 0;
 174 }
 175
 176 static void
 177 batadv_vis_data_insert_interfaces(struct hlist_head *list,
 178                                   struct batadv_vis_packet *packet,
 179                                   struct batadv_vis_info_entry *entries)
 180 {
 181         int i;
 182
 183         for (i = 0; i < packet->entries; i++) {
 184                 if (entries[i].quality == 0)
 185                         continue;
 186
 187                 if (batadv_compare_eth(entries[i].src, packet->vis_orig))
 188                         continue;
 189
 190                 batadv_vis_data_insert_interface(entries[i].src, list, false);
 191         }
 192 }
 193
 194 static void batadv_vis_data_read_entries(struct seq_file *seq,
 195                                          struct hlist_head *list,
 196                                          struct batadv_vis_packet *packet,
 197                                          struct batadv_vis_info_entry *entries)
 198 {
 199         int i;
 200         struct batadv_vis_if_list_entry *entry;
 201         struct hlist_node *pos;
 202
 203         hlist_for_each_entry(entry, pos, list, list) {
 204                 seq_printf(seq, "%pM,", entry->addr);
 205
 206                 for (i = 0; i < packet->entries; i++)
 207                         batadv_vis_data_read_entry(seq, &entries[i],
 208                                                    entry->addr, entry->primary);
 209
 210                 /* add primary/secondary records */
 211                 if (batadv_compare_eth(entry->addr, packet->vis_orig))
 212                         batadv_vis_data_read_prim_sec(seq, list);
 213
 214                 seq_printf(seq, "\n");
 215         }
 216 }
 217
 218 static void batadv_vis_seq_print_text_bucket(struct seq_file *seq,
 219                                              const struct hlist_head *head)
 220 {
 221         struct hlist_node *node;
 222         struct batadv_vis_info *info;
 223         struct batadv_vis_packet *packet;
 224         uint8_t *entries_pos;
 225         struct batadv_vis_info_entry *entries;
 226         struct batadv_vis_if_list_entry *entry;
 227         struct hlist_node *pos, *n;
 228
 229         HLIST_HEAD(vis_if_list);
 230
 231         hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 232                 packet = (struct batadv_vis_packet *)info->skb_packet->data;
 233                 entries_pos = (uint8_t *)packet + sizeof(*packet);
 234                 entries = (struct batadv_vis_info_entry *)entries_pos;
 235
 236                 batadv_vis_data_insert_interface(packet->vis_orig, &vis_if_list,
 237                                                  true);
 238                 batadv_vis_data_insert_interfaces(&vis_if_list, packet,
 239                                                   entries);
 240                 batadv_vis_data_read_entries(seq, &vis_if_list, packet,
 241                                              entries);
 242
 243                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 244                         hlist_del(&entry->list);
 245                         kfree(entry);
 246                 }
 247         }
 248 }
 249
 250 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 251 {
 252         struct batadv_hard_iface *primary_if;
 253         struct hlist_head *head;
 254         struct net_device *net_dev = (struct net_device *)seq->private;
 255         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 256         struct batadv_hashtable *hash = bat_priv->vis.hash;
 257         uint32_t i;
 258         int ret = 0;
 259         int vis_server = atomic_read(&bat_priv->vis_mode);
 260
 261         primary_if = batadv_primary_if_get_selected(bat_priv);
 262         if (!primary_if)
 263                 goto out;
 264
 265         if (vis_server == BATADV_VIS_TYPE_CLIENT_UPDATE)
 266                 goto out;
 267
 268         spin_lock_bh(&bat_priv->vis.hash_lock);
 269         for (i = 0; i < hash->size; i++) {
 270                 head = &hash->table[i];
 271                 batadv_vis_seq_print_text_bucket(seq, head);
 272         }
 273         spin_unlock_bh(&bat_priv->vis.hash_lock);
 274
 275 out:
 276         if (primary_if)
 277                 batadv_hardif_free_ref(primary_if);
 278         return ret;
 279 }
 280
 281 /* add the info packet to the send list, if it was not
 282  * already linked in.
 283  */
 284 static void batadv_send_list_add(struct batadv_priv *bat_priv,
 285                                  struct batadv_vis_info *info)
 286 {
 287         if (list_empty(&info->send_list)) {
 288                 kref_get(&info->refcount);
 289                 list_add_tail(&info->send_list, &bat_priv->vis.send_list);
 290         }
 291 }
 292
 293 /* delete the info packet from the send list, if it was
 294  * linked in.
 295  */
 296 static void batadv_send_list_del(struct batadv_vis_info *info)
 297 {
 298         if (!list_empty(&info->send_list)) {
 299                 list_del_init(&info->send_list);
 300                 kref_put(&info->refcount, batadv_free_info);
 301         }
 302 }
 303
 304 /* tries to add one entry to the receive list. */
 305 static void batadv_recv_list_add(struct batadv_priv *bat_priv,
 306                                  struct list_head *recv_list, const char *mac)
 307 {
 308         struct batadv_vis_recvlist_node *entry;
 309
 310         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 311         if (!entry)
 312                 return;
 313
 314         memcpy(entry->mac, mac, ETH_ALEN);
 315         spin_lock_bh(&bat_priv->vis.list_lock);
 316         list_add_tail(&entry->list, recv_list);
 317         spin_unlock_bh(&bat_priv->vis.list_lock);
 318 }
 319
 320 /* returns 1 if this mac is in the recv_list */
 321 static int batadv_recv_list_is_in(struct batadv_priv *bat_priv,
 322                                   const struct list_head *recv_list,
 323                                   const char *mac)
 324 {
 325         const struct batadv_vis_recvlist_node *entry;
 326
 327         spin_lock_bh(&bat_priv->vis.list_lock);
 328         list_for_each_entry(entry, recv_list, list) {
 329                 if (batadv_compare_eth(entry->mac, mac)) {
 330                         spin_unlock_bh(&bat_priv->vis.list_lock);
 331                         return 1;
 332                 }
 333         }
 334         spin_unlock_bh(&bat_priv->vis.list_lock);
 335         return 0;
 336 }
 337
 338 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 339  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 340  * is newer than old entries in the hash.
 341  */
 342 static struct batadv_vis_info *
 343 batadv_add_packet(struct batadv_priv *bat_priv,
 344                   struct batadv_vis_packet *vis_packet, int vis_info_len,
 345                   int *is_new, int make_broadcast)
 346 {
 347         struct batadv_vis_info *info, *old_info;
 348         struct batadv_vis_packet *search_packet, *old_packet;
 349         struct batadv_vis_info search_elem;
 350         struct batadv_vis_packet *packet;
 351         struct sk_buff *tmp_skb;
 352         int hash_added;
 353         size_t len;
 354         size_t max_entries;
 355
 356         *is_new = 0;
 357         /* sanity check */
 358         if (!bat_priv->vis.hash)
 359                 return NULL;
 360
 361         /* see if the packet is already in vis_hash */
 362         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 363         if (!search_elem.skb_packet)
 364                 return NULL;
 365         len = sizeof(*search_packet);
 366         tmp_skb = search_elem.skb_packet;
 367         search_packet = (struct batadv_vis_packet *)skb_put(tmp_skb, len);
 368
 369         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 370         old_info = batadv_vis_hash_find(bat_priv, &search_elem);
 371         kfree_skb(search_elem.skb_packet);
 372
 373         if (old_info) {
 374                 tmp_skb = old_info->skb_packet;
 375                 old_packet = (struct batadv_vis_packet *)tmp_skb->data;
 376                 if (!batadv_seq_after(ntohl(vis_packet->seqno),
 377                                       ntohl(old_packet->seqno))) {
 378                         if (old_packet->seqno == vis_packet->seqno) {
 379                                 batadv_recv_list_add(bat_priv,
 380                                                      &old_info->recv_list,
 381                                                      vis_packet->sender_orig);
 382                                 return old_info;
 383                         } else {
 384                                 /* newer packet is already in hash. */
 385                                 return NULL;
 386                         }
 387                 }
 388                 /* remove old entry */
 389                 batadv_hash_remove(bat_priv->vis.hash, batadv_vis_info_cmp,
 390                                    batadv_vis_info_choose, old_info);
 391                 batadv_send_list_del(old_info);
 392                 kref_put(&old_info->refcount, batadv_free_info);
 393         }
 394
 395         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 396         if (!info)
 397                 return NULL;
 398
 399         len = sizeof(*packet) + vis_info_len;
 400         info->skb_packet = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 401         if (!info->skb_packet) {
 402                 kfree(info);
 403                 return NULL;
 404         }
 405         skb_reserve(info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 406         packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
 407
 408         kref_init(&info->refcount);
 409         INIT_LIST_HEAD(&info->send_list);
 410         INIT_LIST_HEAD(&info->recv_list);
 411         info->first_seen = jiffies;
 412         info->bat_priv = bat_priv;
 413         memcpy(packet, vis_packet, len);
 414
 415         /* initialize and add new packet. */
 416         *is_new = 1;
 417
 418         /* Make it a broadcast packet, if required */
 419         if (make_broadcast)
 420                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 421
 422         /* repair if entries is longer than packet. */
 423         max_entries = vis_info_len / sizeof(struct batadv_vis_info_entry);
 424         if (packet->entries > max_entries)
 425                 packet->entries = max_entries;
 426
 427         batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 428
 429         /* try to add it */
 430         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 431                                      batadv_vis_info_choose, info,
 432                                      &info->hash_entry);
 433         if (hash_added != 0) {
 434                 /* did not work (for some reason) */
 435                 kref_put(&info->refcount, batadv_free_info);
 436                 info = NULL;
 437         }
 438
 439         return info;
 440 }
 441
 442 /* handle the server sync packet, forward if needed. */
 443 void batadv_receive_server_sync_packet(struct batadv_priv *bat_priv,
 444                                        struct batadv_vis_packet *vis_packet,
 445                                        int vis_info_len)
 446 {
 447         struct batadv_vis_info *info;
 448         int is_new, make_broadcast;
 449         int vis_server = atomic_read(&bat_priv->vis_mode);
 450
 451         make_broadcast = (vis_server == BATADV_VIS_TYPE_SERVER_SYNC);
 452
 453         spin_lock_bh(&bat_priv->vis.hash_lock);
 454         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 455                                  &is_new, make_broadcast);
 456         if (!info)
 457                 goto end;
 458
 459         /* only if we are server ourselves and packet is newer than the one in
 460          * hash.
 461          */
 462         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC && is_new)
 463                 batadv_send_list_add(bat_priv, info);
 464 end:
 465         spin_unlock_bh(&bat_priv->vis.hash_lock);
 466 }
 467
 468 /* handle an incoming client update packet and schedule forward if needed. */
 469 void batadv_receive_client_update_packet(struct batadv_priv *bat_priv,
 470                                          struct batadv_vis_packet *vis_packet,
 471                                          int vis_info_len)
 472 {
 473         struct batadv_vis_info *info;
 474         struct batadv_vis_packet *packet;
 475         int is_new;
 476         int vis_server = atomic_read(&bat_priv->vis_mode);
 477         int are_target = 0;
 478
 479         /* clients shall not broadcast. */
 480         if (is_broadcast_ether_addr(vis_packet->target_orig))
 481                 return;
 482
 483         /* Are we the target for this VIS packet? */
 484         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC   &&
 485             batadv_is_my_mac(vis_packet->target_orig))
 486                 are_target = 1;
 487
 488         spin_lock_bh(&bat_priv->vis.hash_lock);
 489         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 490                                  &is_new, are_target);
 491
 492         if (!info)
 493                 goto end;
 494         /* note that outdated packets will be dropped at this point. */
 495
 496         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 497
 498         /* send only if we're the target server or ... */
 499         if (are_target && is_new) {
 500                 packet->vis_type = BATADV_VIS_TYPE_SERVER_SYNC; /* upgrade! */
 501                 batadv_send_list_add(bat_priv, info);
 502
 503                 /* ... we're not the recipient (and thus need to forward). */
 504         } else if (!batadv_is_my_mac(packet->target_orig)) {
 505                 batadv_send_list_add(bat_priv, info);
 506         }
 507
 508 end:
 509         spin_unlock_bh(&bat_priv->vis.hash_lock);
 510 }
 511
 512 /* Walk the originators and find the VIS server with the best tq. Set the packet
 513  * address to its address and return the best_tq.
 514  *
 515  * Must be called with the originator hash locked
 516  */
 517 static int batadv_find_best_vis_server(struct batadv_priv *bat_priv,
 518                                        struct batadv_vis_info *info)
 519 {
 520         struct batadv_hashtable *hash = bat_priv->orig_hash;
 521         struct batadv_neigh_node *router;
 522         struct hlist_node *node;
 523         struct hlist_head *head;
 524         struct batadv_orig_node *orig_node;
 525         struct batadv_vis_packet *packet;
 526         int best_tq = -1;
 527         uint32_t i;
 528
 529         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 530
 531         for (i = 0; i < hash->size; i++) {
 532                 head = &hash->table[i];
 533
 534                 rcu_read_lock();
 535                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 536                         router = batadv_orig_node_get_router(orig_node);
 537                         if (!router)
 538                                 continue;
 539
 540                         if ((orig_node->flags & BATADV_VIS_SERVER) &&
 541                             (router->tq_avg > best_tq)) {
 542                                 best_tq = router->tq_avg;
 543                                 memcpy(packet->target_orig, orig_node->orig,
 544                                        ETH_ALEN);
 545                         }
 546                         batadv_neigh_node_free_ref(router);
 547                 }
 548                 rcu_read_unlock();
 549         }
 550
 551         return best_tq;
 552 }
 553
 554 /* Return true if the vis packet is full. */
 555 static bool batadv_vis_packet_full(const struct batadv_vis_info *info)
 556 {
 557         const struct batadv_vis_packet *packet;
 558         size_t num;
 559
 560         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 561         num = BATADV_MAX_VIS_PACKET_SIZE / sizeof(struct batadv_vis_info_entry);
 562
 563         if (num < packet->entries + 1)
 564                 return true;
 565         return false;
 566 }
 567
 568 /* generates a packet of own vis data,
 569  * returns 0 on success, -1 if no packet could be generated
 570  */
 571 static int batadv_generate_vis_packet(struct batadv_priv *bat_priv)
 572 {
 573         struct batadv_hashtable *hash = bat_priv->orig_hash;
 574         struct hlist_node *node;
 575         struct hlist_head *head;
 576         struct batadv_orig_node *orig_node;
 577         struct batadv_neigh_node *router;
 578         struct batadv_vis_info *info = bat_priv->vis.my_info;
 579         struct batadv_vis_packet *packet;
 580         struct batadv_vis_info_entry *entry;
 581         struct batadv_tt_common_entry *tt_common_entry;
 582         uint8_t *packet_pos;
 583         int best_tq = -1;
 584         uint32_t i;
 585
 586         info->first_seen = jiffies;
 587         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 588         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 589
 590         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 591         packet->header.ttl = BATADV_TTL;
 592         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 593         packet->entries = 0;
 594         packet->reserved = 0;
 595         skb_trim(info->skb_packet, sizeof(*packet));
 596
 597         if (packet->vis_type == BATADV_VIS_TYPE_CLIENT_UPDATE) {
 598                 best_tq = batadv_find_best_vis_server(bat_priv, info);
 599
 600                 if (best_tq < 0)
 601                         return best_tq;
 602         }
 603
 604         for (i = 0; i < hash->size; i++) {
 605                 head = &hash->table[i];
 606
 607                 rcu_read_lock();
 608                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 609                         router = batadv_orig_node_get_router(orig_node);
 610                         if (!router)
 611                                 continue;
 612
 613                         if (!batadv_compare_eth(router->addr, orig_node->orig))
 614                                 goto next;
 615
 616                         if (router->if_incoming->if_status != BATADV_IF_ACTIVE)
 617                                 goto next;
 618
 619                         if (router->tq_avg < 1)
 620                                 goto next;
 621
 622                         /* fill one entry into buffer. */
 623                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 624                         entry = (struct batadv_vis_info_entry *)packet_pos;
 625                         memcpy(entry->src,
 626                                router->if_incoming->net_dev->dev_addr,
 627                                ETH_ALEN);
 628                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 629                         entry->quality = router->tq_avg;
 630                         packet->entries++;
 631
 632 next:
 633                         batadv_neigh_node_free_ref(router);
 634
 635                         if (batadv_vis_packet_full(info))
 636                                 goto unlock;
 637                 }
 638                 rcu_read_unlock();
 639         }
 640
 641         hash = bat_priv->tt.local_hash;
 642
 643         for (i = 0; i < hash->size; i++) {
 644                 head = &hash->table[i];
 645
 646                 rcu_read_lock();
 647                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 648                                          hash_entry) {
 649                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 650                         entry = (struct batadv_vis_info_entry *)packet_pos;
 651                         memset(entry->src, 0, ETH_ALEN);
 652                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 653                         entry->quality = 0; /* 0 means TT */
 654                         packet->entries++;
 655
 656                         if (batadv_vis_packet_full(info))
 657                                 goto unlock;
 658                 }
 659                 rcu_read_unlock();
 660         }
 661
 662         return 0;
 663
 664 unlock:
 665         rcu_read_unlock();
 666         return 0;
 667 }
 668
 669 /* free old vis packets. Must be called with this vis_hash_lock
 670  * held
 671  */
 672 static void batadv_purge_vis_packets(struct batadv_priv *bat_priv)
 673 {
 674         uint32_t i;
 675         struct batadv_hashtable *hash = bat_priv->vis.hash;
 676         struct hlist_node *node, *node_tmp;
 677         struct hlist_head *head;
 678         struct batadv_vis_info *info;
 679
 680         for (i = 0; i < hash->size; i++) {
 681                 head = &hash->table[i];
 682
 683                 hlist_for_each_entry_safe(info, node, node_tmp,
 684                                           head, hash_entry) {
 685                         /* never purge own data. */
 686                         if (info == bat_priv->vis.my_info)
 687                                 continue;
 688
 689                         if (batadv_has_timed_out(info->first_seen,
 690                                                  BATADV_VIS_TIMEOUT)) {
 691                                 hlist_del(node);
 692                                 batadv_send_list_del(info);
 693                                 kref_put(&info->refcount, batadv_free_info);
 694                         }
 695                 }
 696         }
 697 }
 698
 699 static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
 700                                         struct batadv_vis_info *info)
 701 {
 702         struct batadv_hashtable *hash = bat_priv->orig_hash;
 703         struct hlist_node *node;
 704         struct hlist_head *head;
 705         struct batadv_orig_node *orig_node;
 706         struct batadv_vis_packet *packet;
 707         struct sk_buff *skb;
 708         uint32_t i;
 709
 710
 711         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 712
 713         /* send to all routers in range. */
 714         for (i = 0; i < hash->size; i++) {
 715                 head = &hash->table[i];
 716
 717                 rcu_read_lock();
 718                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 719                         /* if it's a vis server and reachable, send it. */
 720                         if (!(orig_node->flags & BATADV_VIS_SERVER))
 721                                 continue;
 722
 723                         /* don't send it if we already received the packet from
 724                          * this node.
 725                          */
 726                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
 727                                                    orig_node->orig))
 728                                 continue;
 729
 730                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 731                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 732                         if (!skb)
 733                                 continue;
 734
 735                         if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
 736                                 kfree_skb(skb);
 737                 }
 738                 rcu_read_unlock();
 739         }
 740 }
 741
 742 static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
 743                                       struct batadv_vis_info *info)
 744 {
 745         struct batadv_orig_node *orig_node;
 746         struct sk_buff *skb;
 747         struct batadv_vis_packet *packet;
 748
 749         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 750
 751         orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
 752         if (!orig_node)
 753                 goto out;
 754
 755         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 756         if (!skb)
 757                 goto out;
 758
 759         if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
 760                 kfree_skb(skb);
 761
 762 out:
 763         if (orig_node)
 764                 batadv_orig_node_free_ref(orig_node);
 765 }
 766
 767 /* only send one vis packet. called from batadv_send_vis_packets() */
 768 static void batadv_send_vis_packet(struct batadv_priv *bat_priv,
 769                                    struct batadv_vis_info *info)
 770 {
 771         struct batadv_hard_iface *primary_if;
 772         struct batadv_vis_packet *packet;
 773
 774         primary_if = batadv_primary_if_get_selected(bat_priv);
 775         if (!primary_if)
 776                 goto out;
 777
 778         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 779         if (packet->header.ttl < 2) {
 780                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 781                 goto out;
 782         }
 783
 784         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 785         packet->header.ttl--;
 786
 787         if (is_broadcast_ether_addr(packet->target_orig))
 788                 batadv_broadcast_vis_packet(bat_priv, info);
 789         else
 790                 batadv_unicast_vis_packet(bat_priv, info);
 791         packet->header.ttl++; /* restore TTL */
 792
 793 out:
 794         if (primary_if)
 795                 batadv_hardif_free_ref(primary_if);
 796 }
 797
 798 /* called from timer; send (and maybe generate) vis packet. */
 799 static void batadv_send_vis_packets(struct work_struct *work)
 800 {
 801         struct delayed_work *delayed_work;
 802         struct batadv_priv *bat_priv;
 803         struct batadv_priv_vis *priv_vis;
 804         struct batadv_vis_info *info;
 805
 806         delayed_work = container_of(work, struct delayed_work, work);
 807         priv_vis = container_of(delayed_work, struct batadv_priv_vis, work);
 808         bat_priv = container_of(priv_vis, struct batadv_priv, vis);
 809         spin_lock_bh(&bat_priv->vis.hash_lock);
 810         batadv_purge_vis_packets(bat_priv);
 811
 812         if (batadv_generate_vis_packet(bat_priv) == 0) {
 813                 /* schedule if generation was successful */
 814                 batadv_send_list_add(bat_priv, bat_priv->vis.my_info);
 815         }
 816
 817         while (!list_empty(&bat_priv->vis.send_list)) {
 818                 info = list_first_entry(&bat_priv->vis.send_list,
 819                                         typeof(*info), send_list);
 820
 821                 kref_get(&info->refcount);
 822                 spin_unlock_bh(&bat_priv->vis.hash_lock);
 823
 824                 batadv_send_vis_packet(bat_priv, info);
 825
 826                 spin_lock_bh(&bat_priv->vis.hash_lock);
 827                 batadv_send_list_del(info);
 828                 kref_put(&info->refcount, batadv_free_info);
 829         }
 830         spin_unlock_bh(&bat_priv->vis.hash_lock);
 831
 832         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
 833                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 834 }
 835
 836 /* init the vis server. this may only be called when if_list is already
 837  * initialized (e.g. bat0 is initialized, interfaces have been added)
 838  */
 839 int batadv_vis_init(struct batadv_priv *bat_priv)
 840 {
 841         struct batadv_vis_packet *packet;
 842         int hash_added;
 843         unsigned int len;
 844         unsigned long first_seen;
 845         struct sk_buff *tmp_skb;
 846
 847         if (bat_priv->vis.hash)
 848                 return 0;
 849
 850         spin_lock_bh(&bat_priv->vis.hash_lock);
 851
 852         bat_priv->vis.hash = batadv_hash_new(256);
 853         if (!bat_priv->vis.hash) {
 854                 pr_err("Can't initialize vis_hash\n");
 855                 goto err;
 856         }
 857
 858         batadv_hash_set_lock_class(bat_priv->vis.hash,
 859                                    &batadv_vis_hash_lock_class_key);
 860
 861         bat_priv->vis.my_info = kmalloc(BATADV_MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 862         if (!bat_priv->vis.my_info)
 863                 goto err;
 864
 865         len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE;
 866         len += ETH_HLEN + NET_IP_ALIGN;
 867         bat_priv->vis.my_info->skb_packet = dev_alloc_skb(len);
 868         if (!bat_priv->vis.my_info->skb_packet)
 869                 goto free_info;
 870
 871         skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 872         tmp_skb = bat_priv->vis.my_info->skb_packet;
 873         packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));
 874
 875         /* prefill the vis info */
 876         first_seen = jiffies - msecs_to_jiffies(BATADV_VIS_INTERVAL);
 877         bat_priv->vis.my_info->first_seen = first_seen;
 878         INIT_LIST_HEAD(&bat_priv->vis.my_info->recv_list);
 879         INIT_LIST_HEAD(&bat_priv->vis.my_info->send_list);
 880         kref_init(&bat_priv->vis.my_info->refcount);
 881         bat_priv->vis.my_info->bat_priv = bat_priv;
 882         packet->header.version = BATADV_COMPAT_VERSION;
 883         packet->header.packet_type = BATADV_VIS;
 884         packet->header.ttl = BATADV_TTL;
 885         packet->seqno = 0;
 886         packet->reserved = 0;
 887         packet->entries = 0;
 888
 889         INIT_LIST_HEAD(&bat_priv->vis.send_list);
 890
 891         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 892                                      batadv_vis_info_choose,
 893                                      bat_priv->vis.my_info,
 894                                      &bat_priv->vis.my_info->hash_entry);
 895         if (hash_added != 0) {
 896                 pr_err("Can't add own vis packet into hash\n");
 897                 /* not in hash, need to remove it manually. */
 898                 kref_put(&bat_priv->vis.my_info->refcount, batadv_free_info);
 899                 goto err;
 900         }
 901
 902         spin_unlock_bh(&bat_priv->vis.hash_lock);
 903
 904         INIT_DELAYED_WORK(&bat_priv->vis.work, batadv_send_vis_packets);
 905         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
 906                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 907
 908         return 0;
 909
 910 free_info:
 911         kfree(bat_priv->vis.my_info);
 912         bat_priv->vis.my_info = NULL;
 913 err:
 914         spin_unlock_bh(&bat_priv->vis.hash_lock);
 915         batadv_vis_quit(bat_priv);
 916         return -ENOMEM;
 917 }
 918
 919 /* Decrease the reference count on a hash item info */
 920 static void batadv_free_info_ref(struct hlist_node *node, void *arg)
 921 {
 922         struct batadv_vis_info *info;
 923
 924         info = container_of(node, struct batadv_vis_info, hash_entry);
 925         batadv_send_list_del(info);
 926         kref_put(&info->refcount, batadv_free_info);
 927 }
 928
 929 /* shutdown vis-server */
 930 void batadv_vis_quit(struct batadv_priv *bat_priv)
 931 {
 932         if (!bat_priv->vis.hash)
 933                 return;
 934
 935         cancel_delayed_work_sync(&bat_priv->vis.work);
 936
 937         spin_lock_bh(&bat_priv->vis.hash_lock);
 938         /* properly remove, kill timers ... */
 939         batadv_hash_delete(bat_priv->vis.hash, batadv_free_info_ref, NULL);
 940         bat_priv->vis.hash = NULL;
 941         bat_priv->vis.my_info = NULL;
 942         spin_unlock_bh(&bat_priv->vis.hash_lock);
 943 }