net/batman-adv/vis.c

   1 /* Copyright (C) 2008-2012 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 static void batadv_start_vis_timer(struct batadv_priv *bat_priv);
  32
  33 /* free the info */
  34 static void batadv_free_info(struct kref *ref)
  35 {
  36         struct batadv_vis_info *info;
  37         struct batadv_priv *bat_priv;
  38         struct batadv_recvlist_node *entry, *tmp;
  39
  40         info = container_of(ref, struct batadv_vis_info, refcount);
  41         bat_priv = info->bat_priv;
  42
  43         list_del_init(&info->send_list);
  44         spin_lock_bh(&bat_priv->vis.list_lock);
  45         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  46                 list_del(&entry->list);
  47                 kfree(entry);
  48         }
  49
  50         spin_unlock_bh(&bat_priv->vis.list_lock);
  51         kfree_skb(info->skb_packet);
  52         kfree(info);
  53 }
  54
  55 /* Compare two vis packets, used by the hashing algorithm */
  56 static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
  57 {
  58         const struct batadv_vis_info *d1, *d2;
  59         const struct batadv_vis_packet *p1, *p2;
  60
  61         d1 = container_of(node, struct batadv_vis_info, hash_entry);
  62         d2 = data2;
  63         p1 = (struct batadv_vis_packet *)d1->skb_packet->data;
  64         p2 = (struct batadv_vis_packet *)d2->skb_packet->data;
  65         return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
  66 }
  67
  68 /* hash function to choose an entry in a hash table of given size
  69  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  70  */
  71 static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
  72 {
  73         const struct batadv_vis_info *vis_info = data;
  74         const struct batadv_vis_packet *packet;
  75         const unsigned char *key;
  76         uint32_t hash = 0;
  77         size_t i;
  78
  79         packet = (struct batadv_vis_packet *)vis_info->skb_packet->data;
  80         key = packet->vis_orig;
  81         for (i = 0; i < ETH_ALEN; i++) {
  82                 hash += key[i];
  83                 hash += (hash << 10);
  84                 hash ^= (hash >> 6);
  85         }
  86
  87         hash += (hash << 3);
  88         hash ^= (hash >> 11);
  89         hash += (hash << 15);
  90
  91         return hash % size;
  92 }
  93
  94 static struct batadv_vis_info *
  95 batadv_vis_hash_find(struct batadv_priv *bat_priv, const void *data)
  96 {
  97         struct batadv_hashtable *hash = bat_priv->vis.hash;
  98         struct hlist_head *head;
  99         struct hlist_node *node;
 100         struct batadv_vis_info *vis_info, *vis_info_tmp = NULL;
 101         uint32_t index;
 102
 103         if (!hash)
 104                 return NULL;
 105
 106         index = batadv_vis_info_choose(data, hash->size);
 107         head = &hash->table[index];
 108
 109         rcu_read_lock();
 110         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 111                 if (!batadv_vis_info_cmp(node, data))
 112                         continue;
 113
 114                 vis_info_tmp = vis_info;
 115                 break;
 116         }
 117         rcu_read_unlock();
 118
 119         return vis_info_tmp;
 120 }
 121
 122 /* insert interface to the list of interfaces of one originator, if it
 123  * does not already exist in the list
 124  */
 125 static void batadv_vis_data_insert_interface(const uint8_t *interface,
 126                                              struct hlist_head *if_list,
 127                                              bool primary)
 128 {
 129         struct batadv_if_list_entry *entry;
 130         struct hlist_node *pos;
 131
 132         hlist_for_each_entry(entry, pos, if_list, list) {
 133                 if (batadv_compare_eth(entry->addr, interface))
 134                         return;
 135         }
 136
 137         /* it's a new address, add it to the list */
 138         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 139         if (!entry)
 140                 return;
 141         memcpy(entry->addr, interface, ETH_ALEN);
 142         entry->primary = primary;
 143         hlist_add_head(&entry->list, if_list);
 144 }
 145
 146 static void batadv_vis_data_read_prim_sec(struct seq_file *seq,
 147                                           const struct hlist_head *if_list)
 148 {
 149         struct batadv_if_list_entry *entry;
 150         struct hlist_node *pos;
 151
 152         hlist_for_each_entry(entry, pos, if_list, list) {
 153                 if (entry->primary)
 154                         seq_printf(seq, "PRIMARY, ");
 155                 else
 156                         seq_printf(seq,  "SEC %pM, ", entry->addr);
 157         }
 158 }
 159
 160 /* read an entry  */
 161 static ssize_t
 162 batadv_vis_data_read_entry(struct seq_file *seq,
 163                            const struct batadv_vis_info_entry *entry,
 164                            const uint8_t *src, bool primary)
 165 {
 166         if (primary && entry->quality == 0)
 167                 return seq_printf(seq, "TT %pM, ", entry->dest);
 168         else if (batadv_compare_eth(entry->src, src))
 169                 return seq_printf(seq, "TQ %pM %d, ", entry->dest,
 170                                   entry->quality);
 171
 172         return 0;
 173 }
 174
 175 static void
 176 batadv_vis_data_insert_interfaces(struct hlist_head *list,
 177                                   struct batadv_vis_packet *packet,
 178                                   struct batadv_vis_info_entry *entries)
 179 {
 180         int i;
 181
 182         for (i = 0; i < packet->entries; i++) {
 183                 if (entries[i].quality == 0)
 184                         continue;
 185
 186                 if (batadv_compare_eth(entries[i].src, packet->vis_orig))
 187                         continue;
 188
 189                 batadv_vis_data_insert_interface(entries[i].src, list, false);
 190         }
 191 }
 192
 193 static void batadv_vis_data_read_entries(struct seq_file *seq,
 194                                          struct hlist_head *list,
 195                                          struct batadv_vis_packet *packet,
 196                                          struct batadv_vis_info_entry *entries)
 197 {
 198         int i;
 199         struct batadv_if_list_entry *entry;
 200         struct hlist_node *pos;
 201
 202         hlist_for_each_entry(entry, pos, list, list) {
 203                 seq_printf(seq, "%pM,", entry->addr);
 204
 205                 for (i = 0; i < packet->entries; i++)
 206                         batadv_vis_data_read_entry(seq, &entries[i],
 207                                                    entry->addr, entry->primary);
 208
 209                 /* add primary/secondary records */
 210                 if (batadv_compare_eth(entry->addr, packet->vis_orig))
 211                         batadv_vis_data_read_prim_sec(seq, list);
 212
 213                 seq_printf(seq, "\n");
 214         }
 215 }
 216
 217 static void batadv_vis_seq_print_text_bucket(struct seq_file *seq,
 218                                              const struct hlist_head *head)
 219 {
 220         struct hlist_node *node;
 221         struct batadv_vis_info *info;
 222         struct batadv_vis_packet *packet;
 223         uint8_t *entries_pos;
 224         struct batadv_vis_info_entry *entries;
 225         struct batadv_if_list_entry *entry;
 226         struct hlist_node *pos, *n;
 227
 228         HLIST_HEAD(vis_if_list);
 229
 230         hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 231                 packet = (struct batadv_vis_packet *)info->skb_packet->data;
 232                 entries_pos = (uint8_t *)packet + sizeof(*packet);
 233                 entries = (struct batadv_vis_info_entry *)entries_pos;
 234
 235                 batadv_vis_data_insert_interface(packet->vis_orig, &vis_if_list,
 236                                                  true);
 237                 batadv_vis_data_insert_interfaces(&vis_if_list, packet,
 238                                                   entries);
 239                 batadv_vis_data_read_entries(seq, &vis_if_list, packet,
 240                                              entries);
 241
 242                 hlist_for_each_entry_safe(entry, pos, n, &vis_if_list, list) {
 243                         hlist_del(&entry->list);
 244                         kfree(entry);
 245                 }
 246         }
 247 }
 248
 249 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 250 {
 251         struct batadv_hard_iface *primary_if;
 252         struct hlist_head *head;
 253         struct net_device *net_dev = (struct net_device *)seq->private;
 254         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 255         struct batadv_hashtable *hash = bat_priv->vis.hash;
 256         uint32_t i;
 257         int ret = 0;
 258         int vis_server = atomic_read(&bat_priv->vis_mode);
 259
 260         primary_if = batadv_primary_if_get_selected(bat_priv);
 261         if (!primary_if)
 262                 goto out;
 263
 264         if (vis_server == BATADV_VIS_TYPE_CLIENT_UPDATE)
 265                 goto out;
 266
 267         spin_lock_bh(&bat_priv->vis.hash_lock);
 268         for (i = 0; i < hash->size; i++) {
 269                 head = &hash->table[i];
 270                 batadv_vis_seq_print_text_bucket(seq, head);
 271         }
 272         spin_unlock_bh(&bat_priv->vis.hash_lock);
 273
 274 out:
 275         if (primary_if)
 276                 batadv_hardif_free_ref(primary_if);
 277         return ret;
 278 }
 279
 280 /* add the info packet to the send list, if it was not
 281  * already linked in.
 282  */
 283 static void batadv_send_list_add(struct batadv_priv *bat_priv,
 284                                  struct batadv_vis_info *info)
 285 {
 286         if (list_empty(&info->send_list)) {
 287                 kref_get(&info->refcount);
 288                 list_add_tail(&info->send_list, &bat_priv->vis.send_list);
 289         }
 290 }
 291
 292 /* delete the info packet from the send list, if it was
 293  * linked in.
 294  */
 295 static void batadv_send_list_del(struct batadv_vis_info *info)
 296 {
 297         if (!list_empty(&info->send_list)) {
 298                 list_del_init(&info->send_list);
 299                 kref_put(&info->refcount, batadv_free_info);
 300         }
 301 }
 302
 303 /* tries to add one entry to the receive list. */
 304 static void batadv_recv_list_add(struct batadv_priv *bat_priv,
 305                                  struct list_head *recv_list, const char *mac)
 306 {
 307         struct batadv_recvlist_node *entry;
 308
 309         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 310         if (!entry)
 311                 return;
 312
 313         memcpy(entry->mac, mac, ETH_ALEN);
 314         spin_lock_bh(&bat_priv->vis.list_lock);
 315         list_add_tail(&entry->list, recv_list);
 316         spin_unlock_bh(&bat_priv->vis.list_lock);
 317 }
 318
 319 /* returns 1 if this mac is in the recv_list */
 320 static int batadv_recv_list_is_in(struct batadv_priv *bat_priv,
 321                                   const struct list_head *recv_list,
 322                                   const char *mac)
 323 {
 324         const struct batadv_recvlist_node *entry;
 325
 326         spin_lock_bh(&bat_priv->vis.list_lock);
 327         list_for_each_entry(entry, recv_list, list) {
 328                 if (batadv_compare_eth(entry->mac, mac)) {
 329                         spin_unlock_bh(&bat_priv->vis.list_lock);
 330                         return 1;
 331                 }
 332         }
 333         spin_unlock_bh(&bat_priv->vis.list_lock);
 334         return 0;
 335 }
 336
 337 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 338  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 339  * is newer than old entries in the hash.
 340  */
 341 static struct batadv_vis_info *
 342 batadv_add_packet(struct batadv_priv *bat_priv,
 343                   struct batadv_vis_packet *vis_packet, int vis_info_len,
 344                   int *is_new, int make_broadcast)
 345 {
 346         struct batadv_vis_info *info, *old_info;
 347         struct batadv_vis_packet *search_packet, *old_packet;
 348         struct batadv_vis_info search_elem;
 349         struct batadv_vis_packet *packet;
 350         struct sk_buff *tmp_skb;
 351         int hash_added;
 352         size_t len;
 353         size_t max_entries;
 354
 355         *is_new = 0;
 356         /* sanity check */
 357         if (!bat_priv->vis.hash)
 358                 return NULL;
 359
 360         /* see if the packet is already in vis_hash */
 361         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 362         if (!search_elem.skb_packet)
 363                 return NULL;
 364         len = sizeof(*search_packet);
 365         tmp_skb = search_elem.skb_packet;
 366         search_packet = (struct batadv_vis_packet *)skb_put(tmp_skb, len);
 367
 368         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 369         old_info = batadv_vis_hash_find(bat_priv, &search_elem);
 370         kfree_skb(search_elem.skb_packet);
 371
 372         if (old_info) {
 373                 tmp_skb = old_info->skb_packet;
 374                 old_packet = (struct batadv_vis_packet *)tmp_skb->data;
 375                 if (!batadv_seq_after(ntohl(vis_packet->seqno),
 376                                       ntohl(old_packet->seqno))) {
 377                         if (old_packet->seqno == vis_packet->seqno) {
 378                                 batadv_recv_list_add(bat_priv,
 379                                                      &old_info->recv_list,
 380                                                      vis_packet->sender_orig);
 381                                 return old_info;
 382                         } else {
 383                                 /* newer packet is already in hash. */
 384                                 return NULL;
 385                         }
 386                 }
 387                 /* remove old entry */
 388                 batadv_hash_remove(bat_priv->vis.hash, batadv_vis_info_cmp,
 389                                    batadv_vis_info_choose, old_info);
 390                 batadv_send_list_del(old_info);
 391                 kref_put(&old_info->refcount, batadv_free_info);
 392         }
 393
 394         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 395         if (!info)
 396                 return NULL;
 397
 398         len = sizeof(*packet) + vis_info_len;
 399         info->skb_packet = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 400         if (!info->skb_packet) {
 401                 kfree(info);
 402                 return NULL;
 403         }
 404         skb_reserve(info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 405         packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
 406
 407         kref_init(&info->refcount);
 408         INIT_LIST_HEAD(&info->send_list);
 409         INIT_LIST_HEAD(&info->recv_list);
 410         info->first_seen = jiffies;
 411         info->bat_priv = bat_priv;
 412         memcpy(packet, vis_packet, len);
 413
 414         /* initialize and add new packet. */
 415         *is_new = 1;
 416
 417         /* Make it a broadcast packet, if required */
 418         if (make_broadcast)
 419                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 420
 421         /* repair if entries is longer than packet. */
 422         max_entries = vis_info_len / sizeof(struct batadv_vis_info_entry);
 423         if (packet->entries > max_entries)
 424                 packet->entries = max_entries;
 425
 426         batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 427
 428         /* try to add it */
 429         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 430                                      batadv_vis_info_choose, info,
 431                                      &info->hash_entry);
 432         if (hash_added != 0) {
 433                 /* did not work (for some reason) */
 434                 kref_put(&info->refcount, batadv_free_info);
 435                 info = NULL;
 436         }
 437
 438         return info;
 439 }
 440
 441 /* handle the server sync packet, forward if needed. */
 442 void batadv_receive_server_sync_packet(struct batadv_priv *bat_priv,
 443                                        struct batadv_vis_packet *vis_packet,
 444                                        int vis_info_len)
 445 {
 446         struct batadv_vis_info *info;
 447         int is_new, make_broadcast;
 448         int vis_server = atomic_read(&bat_priv->vis_mode);
 449
 450         make_broadcast = (vis_server == BATADV_VIS_TYPE_SERVER_SYNC);
 451
 452         spin_lock_bh(&bat_priv->vis.hash_lock);
 453         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 454                                  &is_new, make_broadcast);
 455         if (!info)
 456                 goto end;
 457
 458         /* only if we are server ourselves and packet is newer than the one in
 459          * hash.
 460          */
 461         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC && is_new)
 462                 batadv_send_list_add(bat_priv, info);
 463 end:
 464         spin_unlock_bh(&bat_priv->vis.hash_lock);
 465 }
 466
 467 /* handle an incoming client update packet and schedule forward if needed. */
 468 void batadv_receive_client_update_packet(struct batadv_priv *bat_priv,
 469                                          struct batadv_vis_packet *vis_packet,
 470                                          int vis_info_len)
 471 {
 472         struct batadv_vis_info *info;
 473         struct batadv_vis_packet *packet;
 474         int is_new;
 475         int vis_server = atomic_read(&bat_priv->vis_mode);
 476         int are_target = 0;
 477
 478         /* clients shall not broadcast. */
 479         if (is_broadcast_ether_addr(vis_packet->target_orig))
 480                 return;
 481
 482         /* Are we the target for this VIS packet? */
 483         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC   &&
 484             batadv_is_my_mac(vis_packet->target_orig))
 485                 are_target = 1;
 486
 487         spin_lock_bh(&bat_priv->vis.hash_lock);
 488         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 489                                  &is_new, are_target);
 490
 491         if (!info)
 492                 goto end;
 493         /* note that outdated packets will be dropped at this point. */
 494
 495         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 496
 497         /* send only if we're the target server or ... */
 498         if (are_target && is_new) {
 499                 packet->vis_type = BATADV_VIS_TYPE_SERVER_SYNC; /* upgrade! */
 500                 batadv_send_list_add(bat_priv, info);
 501
 502                 /* ... we're not the recipient (and thus need to forward). */
 503         } else if (!batadv_is_my_mac(packet->target_orig)) {
 504                 batadv_send_list_add(bat_priv, info);
 505         }
 506
 507 end:
 508         spin_unlock_bh(&bat_priv->vis.hash_lock);
 509 }
 510
 511 /* Walk the originators and find the VIS server with the best tq. Set the packet
 512  * address to its address and return the best_tq.
 513  *
 514  * Must be called with the originator hash locked
 515  */
 516 static int batadv_find_best_vis_server(struct batadv_priv *bat_priv,
 517                                        struct batadv_vis_info *info)
 518 {
 519         struct batadv_hashtable *hash = bat_priv->orig_hash;
 520         struct batadv_neigh_node *router;
 521         struct hlist_node *node;
 522         struct hlist_head *head;
 523         struct batadv_orig_node *orig_node;
 524         struct batadv_vis_packet *packet;
 525         int best_tq = -1;
 526         uint32_t i;
 527
 528         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 529
 530         for (i = 0; i < hash->size; i++) {
 531                 head = &hash->table[i];
 532
 533                 rcu_read_lock();
 534                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 535                         router = batadv_orig_node_get_router(orig_node);
 536                         if (!router)
 537                                 continue;
 538
 539                         if ((orig_node->flags & BATADV_VIS_SERVER) &&
 540                             (router->tq_avg > best_tq)) {
 541                                 best_tq = router->tq_avg;
 542                                 memcpy(packet->target_orig, orig_node->orig,
 543                                        ETH_ALEN);
 544                         }
 545                         batadv_neigh_node_free_ref(router);
 546                 }
 547                 rcu_read_unlock();
 548         }
 549
 550         return best_tq;
 551 }
 552
 553 /* Return true if the vis packet is full. */
 554 static bool batadv_vis_packet_full(const struct batadv_vis_info *info)
 555 {
 556         const struct batadv_vis_packet *packet;
 557         size_t num;
 558
 559         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 560         num = BATADV_MAX_VIS_PACKET_SIZE / sizeof(struct batadv_vis_info_entry);
 561
 562         if (num < packet->entries + 1)
 563                 return true;
 564         return false;
 565 }
 566
 567 /* generates a packet of own vis data,
 568  * returns 0 on success, -1 if no packet could be generated
 569  */
 570 static int batadv_generate_vis_packet(struct batadv_priv *bat_priv)
 571 {
 572         struct batadv_hashtable *hash = bat_priv->orig_hash;
 573         struct hlist_node *node;
 574         struct hlist_head *head;
 575         struct batadv_orig_node *orig_node;
 576         struct batadv_neigh_node *router;
 577         struct batadv_vis_info *info = bat_priv->vis.my_info;
 578         struct batadv_vis_packet *packet;
 579         struct batadv_vis_info_entry *entry;
 580         struct batadv_tt_common_entry *tt_common_entry;
 581         uint8_t *packet_pos;
 582         int best_tq = -1;
 583         uint32_t i;
 584
 585         info->first_seen = jiffies;
 586         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 587         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 588
 589         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 590         packet->header.ttl = BATADV_TTL;
 591         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 592         packet->entries = 0;
 593         packet->reserved = 0;
 594         skb_trim(info->skb_packet, sizeof(*packet));
 595
 596         if (packet->vis_type == BATADV_VIS_TYPE_CLIENT_UPDATE) {
 597                 best_tq = batadv_find_best_vis_server(bat_priv, info);
 598
 599                 if (best_tq < 0)
 600                         return best_tq;
 601         }
 602
 603         for (i = 0; i < hash->size; i++) {
 604                 head = &hash->table[i];
 605
 606                 rcu_read_lock();
 607                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 608                         router = batadv_orig_node_get_router(orig_node);
 609                         if (!router)
 610                                 continue;
 611
 612                         if (!batadv_compare_eth(router->addr, orig_node->orig))
 613                                 goto next;
 614
 615                         if (router->if_incoming->if_status != BATADV_IF_ACTIVE)
 616                                 goto next;
 617
 618                         if (router->tq_avg < 1)
 619                                 goto next;
 620
 621                         /* fill one entry into buffer. */
 622                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 623                         entry = (struct batadv_vis_info_entry *)packet_pos;
 624                         memcpy(entry->src,
 625                                router->if_incoming->net_dev->dev_addr,
 626                                ETH_ALEN);
 627                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 628                         entry->quality = router->tq_avg;
 629                         packet->entries++;
 630
 631 next:
 632                         batadv_neigh_node_free_ref(router);
 633
 634                         if (batadv_vis_packet_full(info))
 635                                 goto unlock;
 636                 }
 637                 rcu_read_unlock();
 638         }
 639
 640         hash = bat_priv->tt.local_hash;
 641
 642         for (i = 0; i < hash->size; i++) {
 643                 head = &hash->table[i];
 644
 645                 rcu_read_lock();
 646                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 647                                          hash_entry) {
 648                         packet_pos = skb_put(info->skb_packet, sizeof(*entry));
 649                         entry = (struct batadv_vis_info_entry *)packet_pos;
 650                         memset(entry->src, 0, ETH_ALEN);
 651                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 652                         entry->quality = 0; /* 0 means TT */
 653                         packet->entries++;
 654
 655                         if (batadv_vis_packet_full(info))
 656                                 goto unlock;
 657                 }
 658                 rcu_read_unlock();
 659         }
 660
 661         return 0;
 662
 663 unlock:
 664         rcu_read_unlock();
 665         return 0;
 666 }
 667
 668 /* free old vis packets. Must be called with this vis_hash_lock
 669  * held
 670  */
 671 static void batadv_purge_vis_packets(struct batadv_priv *bat_priv)
 672 {
 673         uint32_t i;
 674         struct batadv_hashtable *hash = bat_priv->vis.hash;
 675         struct hlist_node *node, *node_tmp;
 676         struct hlist_head *head;
 677         struct batadv_vis_info *info;
 678
 679         for (i = 0; i < hash->size; i++) {
 680                 head = &hash->table[i];
 681
 682                 hlist_for_each_entry_safe(info, node, node_tmp,
 683                                           head, hash_entry) {
 684                         /* never purge own data. */
 685                         if (info == bat_priv->vis.my_info)
 686                                 continue;
 687
 688                         if (batadv_has_timed_out(info->first_seen,
 689                                                  BATADV_VIS_TIMEOUT)) {
 690                                 hlist_del(node);
 691                                 batadv_send_list_del(info);
 692                                 kref_put(&info->refcount, batadv_free_info);
 693                         }
 694                 }
 695         }
 696 }
 697
 698 static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
 699                                         struct batadv_vis_info *info)
 700 {
 701         struct batadv_hashtable *hash = bat_priv->orig_hash;
 702         struct hlist_node *node;
 703         struct hlist_head *head;
 704         struct batadv_orig_node *orig_node;
 705         struct batadv_vis_packet *packet;
 706         struct sk_buff *skb;
 707         uint32_t i;
 708
 709
 710         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 711
 712         /* send to all routers in range. */
 713         for (i = 0; i < hash->size; i++) {
 714                 head = &hash->table[i];
 715
 716                 rcu_read_lock();
 717                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 718                         /* if it's a vis server and reachable, send it. */
 719                         if (!(orig_node->flags & BATADV_VIS_SERVER))
 720                                 continue;
 721
 722                         /* don't send it if we already received the packet from
 723                          * this node.
 724                          */
 725                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
 726                                                    orig_node->orig))
 727                                 continue;
 728
 729                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 730                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 731                         if (!skb)
 732                                 continue;
 733
 734                         if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
 735                                 kfree_skb(skb);
 736                 }
 737                 rcu_read_unlock();
 738         }
 739 }
 740
 741 static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
 742                                       struct batadv_vis_info *info)
 743 {
 744         struct batadv_orig_node *orig_node;
 745         struct sk_buff *skb;
 746         struct batadv_vis_packet *packet;
 747
 748         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 749
 750         orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
 751         if (!orig_node)
 752                 goto out;
 753
 754         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 755         if (!skb)
 756                 goto out;
 757
 758         if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
 759                 kfree_skb(skb);
 760
 761 out:
 762         if (orig_node)
 763                 batadv_orig_node_free_ref(orig_node);
 764 }
 765
 766 /* only send one vis packet. called from batadv_send_vis_packets() */
 767 static void batadv_send_vis_packet(struct batadv_priv *bat_priv,
 768                                    struct batadv_vis_info *info)
 769 {
 770         struct batadv_hard_iface *primary_if;
 771         struct batadv_vis_packet *packet;
 772
 773         primary_if = batadv_primary_if_get_selected(bat_priv);
 774         if (!primary_if)
 775                 goto out;
 776
 777         packet = (struct batadv_vis_packet *)info->skb_packet->data;
 778         if (packet->header.ttl < 2) {
 779                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 780                 goto out;
 781         }
 782
 783         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 784         packet->header.ttl--;
 785
 786         if (is_broadcast_ether_addr(packet->target_orig))
 787                 batadv_broadcast_vis_packet(bat_priv, info);
 788         else
 789                 batadv_unicast_vis_packet(bat_priv, info);
 790         packet->header.ttl++; /* restore TTL */
 791
 792 out:
 793         if (primary_if)
 794                 batadv_hardif_free_ref(primary_if);
 795 }
 796
 797 /* called from timer; send (and maybe generate) vis packet. */
 798 static void batadv_send_vis_packets(struct work_struct *work)
 799 {
 800         struct delayed_work *delayed_work;
 801         struct batadv_priv *bat_priv;
 802         struct batadv_priv_vis *priv_vis;
 803         struct batadv_vis_info *info;
 804
 805         delayed_work = container_of(work, struct delayed_work, work);
 806         priv_vis = container_of(delayed_work, struct batadv_priv_vis, work);
 807         bat_priv = container_of(priv_vis, struct batadv_priv, vis);
 808         spin_lock_bh(&bat_priv->vis.hash_lock);
 809         batadv_purge_vis_packets(bat_priv);
 810
 811         if (batadv_generate_vis_packet(bat_priv) == 0) {
 812                 /* schedule if generation was successful */
 813                 batadv_send_list_add(bat_priv, bat_priv->vis.my_info);
 814         }
 815
 816         while (!list_empty(&bat_priv->vis.send_list)) {
 817                 info = list_first_entry(&bat_priv->vis.send_list,
 818                                         typeof(*info), send_list);
 819
 820                 kref_get(&info->refcount);
 821                 spin_unlock_bh(&bat_priv->vis.hash_lock);
 822
 823                 batadv_send_vis_packet(bat_priv, info);
 824
 825                 spin_lock_bh(&bat_priv->vis.hash_lock);
 826                 batadv_send_list_del(info);
 827                 kref_put(&info->refcount, batadv_free_info);
 828         }
 829         spin_unlock_bh(&bat_priv->vis.hash_lock);
 830         batadv_start_vis_timer(bat_priv);
 831 }
 832
 833 /* init the vis server. this may only be called when if_list is already
 834  * initialized (e.g. bat0 is initialized, interfaces have been added)
 835  */
 836 int batadv_vis_init(struct batadv_priv *bat_priv)
 837 {
 838         struct batadv_vis_packet *packet;
 839         int hash_added;
 840         unsigned int len;
 841         unsigned long first_seen;
 842         struct sk_buff *tmp_skb;
 843
 844         if (bat_priv->vis.hash)
 845                 return 0;
 846
 847         spin_lock_bh(&bat_priv->vis.hash_lock);
 848
 849         bat_priv->vis.hash = batadv_hash_new(256);
 850         if (!bat_priv->vis.hash) {
 851                 pr_err("Can't initialize vis_hash\n");
 852                 goto err;
 853         }
 854
 855         bat_priv->vis.my_info = kmalloc(BATADV_MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 856         if (!bat_priv->vis.my_info)
 857                 goto err;
 858
 859         len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE;
 860         len += ETH_HLEN + NET_IP_ALIGN;
 861         bat_priv->vis.my_info->skb_packet = dev_alloc_skb(len);
 862         if (!bat_priv->vis.my_info->skb_packet)
 863                 goto free_info;
 864
 865         skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 866         tmp_skb = bat_priv->vis.my_info->skb_packet;
 867         packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));
 868
 869         /* prefill the vis info */
 870         first_seen = jiffies - msecs_to_jiffies(BATADV_VIS_INTERVAL);
 871         bat_priv->vis.my_info->first_seen = first_seen;
 872         INIT_LIST_HEAD(&bat_priv->vis.my_info->recv_list);
 873         INIT_LIST_HEAD(&bat_priv->vis.my_info->send_list);
 874         kref_init(&bat_priv->vis.my_info->refcount);
 875         bat_priv->vis.my_info->bat_priv = bat_priv;
 876         packet->header.version = BATADV_COMPAT_VERSION;
 877         packet->header.packet_type = BATADV_VIS;
 878         packet->header.ttl = BATADV_TTL;
 879         packet->seqno = 0;
 880         packet->reserved = 0;
 881         packet->entries = 0;
 882
 883         INIT_LIST_HEAD(&bat_priv->vis.send_list);
 884
 885         hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
 886                                      batadv_vis_info_choose,
 887                                      bat_priv->vis.my_info,
 888                                      &bat_priv->vis.my_info->hash_entry);
 889         if (hash_added != 0) {
 890                 pr_err("Can't add own vis packet into hash\n");
 891                 /* not in hash, need to remove it manually. */
 892                 kref_put(&bat_priv->vis.my_info->refcount, batadv_free_info);
 893                 goto err;
 894         }
 895
 896         spin_unlock_bh(&bat_priv->vis.hash_lock);
 897         batadv_start_vis_timer(bat_priv);
 898         return 0;
 899
 900 free_info:
 901         kfree(bat_priv->vis.my_info);
 902         bat_priv->vis.my_info = NULL;
 903 err:
 904         spin_unlock_bh(&bat_priv->vis.hash_lock);
 905         batadv_vis_quit(bat_priv);
 906         return -ENOMEM;
 907 }
 908
 909 /* Decrease the reference count on a hash item info */
 910 static void batadv_free_info_ref(struct hlist_node *node, void *arg)
 911 {
 912         struct batadv_vis_info *info;
 913
 914         info = container_of(node, struct batadv_vis_info, hash_entry);
 915         batadv_send_list_del(info);
 916         kref_put(&info->refcount, batadv_free_info);
 917 }
 918
 919 /* shutdown vis-server */
 920 void batadv_vis_quit(struct batadv_priv *bat_priv)
 921 {
 922         if (!bat_priv->vis.hash)
 923                 return;
 924
 925         cancel_delayed_work_sync(&bat_priv->vis.work);
 926
 927         spin_lock_bh(&bat_priv->vis.hash_lock);
 928         /* properly remove, kill timers ... */
 929         batadv_hash_delete(bat_priv->vis.hash, batadv_free_info_ref, NULL);
 930         bat_priv->vis.hash = NULL;
 931         bat_priv->vis.my_info = NULL;
 932         spin_unlock_bh(&bat_priv->vis.hash_lock);
 933 }
 934
 935 /* schedule packets for (re)transmission */
 936 static void batadv_start_vis_timer(struct batadv_priv *bat_priv)
 937 {
 938         INIT_DELAYED_WORK(&bat_priv->vis.work, batadv_send_vis_packets);
 939         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
 940                            msecs_to_jiffies(BATADV_VIS_INTERVAL));
 941 }