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 MAX_VIS_PACKET_SIZE 1000
  30
  31 static void start_vis_timer(struct bat_priv *bat_priv);
  32
  33 /* free the info */
  34 static void free_info(struct kref *ref)
  35 {
  36         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  37         struct bat_priv *bat_priv = info->bat_priv;
  38         struct recvlist_node *entry, *tmp;
  39
  40         list_del_init(&info->send_list);
  41         spin_lock_bh(&bat_priv->vis_list_lock);
  42         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  43                 list_del(&entry->list);
  44                 kfree(entry);
  45         }
  46
  47         spin_unlock_bh(&bat_priv->vis_list_lock);
  48         kfree_skb(info->skb_packet);
  49         kfree(info);
  50 }
  51
  52 /* Compare two vis packets, used by the hashing algorithm */
  53 static int vis_info_cmp(const struct hlist_node *node, const void *data2)
  54 {
  55         const struct vis_info *d1, *d2;
  56         const struct vis_packet *p1, *p2;
  57
  58         d1 = container_of(node, struct vis_info, hash_entry);
  59         d2 = data2;
  60         p1 = (struct vis_packet *)d1->skb_packet->data;
  61         p2 = (struct vis_packet *)d2->skb_packet->data;
  62         return compare_eth(p1->vis_orig, p2->vis_orig);
  63 }
  64
  65 /* hash function to choose an entry in a hash table of given size
  66  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  67  */
  68 static uint32_t vis_info_choose(const void *data, uint32_t size)
  69 {
  70         const struct vis_info *vis_info = data;
  71         const struct vis_packet *packet;
  72         const unsigned char *key;
  73         uint32_t hash = 0;
  74         size_t i;
  75
  76         packet = (struct vis_packet *)vis_info->skb_packet->data;
  77         key = packet->vis_orig;
  78         for (i = 0; i < ETH_ALEN; i++) {
  79                 hash += key[i];
  80                 hash += (hash << 10);
  81                 hash ^= (hash >> 6);
  82         }
  83
  84         hash += (hash << 3);
  85         hash ^= (hash >> 11);
  86         hash += (hash << 15);
  87
  88         return hash % size;
  89 }
  90
  91 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
  92                                       const void *data)
  93 {
  94         struct hashtable_t *hash = bat_priv->vis_hash;
  95         struct hlist_head *head;
  96         struct hlist_node *node;
  97         struct vis_info *vis_info, *vis_info_tmp = NULL;
  98         uint32_t index;
  99
 100         if (!hash)
 101                 return NULL;
 102
 103         index = vis_info_choose(data, hash->size);
 104         head = &hash->table[index];
 105
 106         rcu_read_lock();
 107         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 108                 if (!vis_info_cmp(node, data))
 109                         continue;
 110
 111                 vis_info_tmp = vis_info;
 112                 break;
 113         }
 114         rcu_read_unlock();
 115
 116         return vis_info_tmp;
 117 }
 118
 119 /* insert interface to the list of interfaces of one originator, if it
 120  * does not already exist in the list
 121  */
 122 static void vis_data_insert_interface(const uint8_t *interface,
 123                                       struct hlist_head *if_list,
 124                                       bool primary)
 125 {
 126         struct if_list_entry *entry;
 127         struct hlist_node *pos;
 128
 129         hlist_for_each_entry(entry, pos, if_list, list) {
 130                 if (compare_eth(entry->addr, interface))
 131                         return;
 132         }
 133
 134         /* it's a new address, add it to the list */
 135         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 136         if (!entry)
 137                 return;
 138         memcpy(entry->addr, interface, ETH_ALEN);
 139         entry->primary = primary;
 140         hlist_add_head(&entry->list, if_list);
 141 }
 142
 143 static ssize_t vis_data_read_prim_sec(char *buff,
 144                                       const struct hlist_head *if_list)
 145 {
 146         struct if_list_entry *entry;
 147         struct hlist_node *pos;
 148         size_t len = 0;
 149
 150         hlist_for_each_entry(entry, pos, if_list, list) {
 151                 if (entry->primary)
 152                         len += sprintf(buff + len, "PRIMARY, ");
 153                 else
 154                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 155         }
 156
 157         return len;
 158 }
 159
 160 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 161 {
 162         struct if_list_entry *entry;
 163         struct hlist_node *pos;
 164         size_t count = 0;
 165
 166         hlist_for_each_entry(entry, pos, if_list, list) {
 167                 if (entry->primary)
 168                         count += 9;
 169                 else
 170                         count += 23;
 171         }
 172
 173         return count;
 174 }
 175
 176 /* read an entry  */
 177 static ssize_t vis_data_read_entry(char *buff,
 178                                    const struct vis_info_entry *entry,
 179                                    const uint8_t *src, bool primary)
 180 {
 181         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 182         if (primary && entry->quality == 0)
 183                 return sprintf(buff, "TT %pM, ", entry->dest);
 184         else if (compare_eth(entry->src, src))
 185                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 186                                entry->quality);
 187
 188         return 0;
 189 }
 190
 191 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 192 {
 193         struct hard_iface *primary_if;
 194         struct hlist_node *node;
 195         struct hlist_head *head;
 196         struct vis_info *info;
 197         struct vis_packet *packet;
 198         struct vis_info_entry *entries;
 199         struct net_device *net_dev = (struct net_device *)seq->private;
 200         struct bat_priv *bat_priv = netdev_priv(net_dev);
 201         struct hashtable_t *hash = bat_priv->vis_hash;
 202         HLIST_HEAD(vis_if_list);
 203         struct if_list_entry *entry;
 204         struct hlist_node *pos, *n;
 205         uint32_t i;
 206         int j, ret = 0;
 207         int vis_server = atomic_read(&bat_priv->vis_mode);
 208         size_t buff_pos, buf_size;
 209         char *buff;
 210
 211         primary_if = batadv_primary_if_get_selected(bat_priv);
 212         if (!primary_if)
 213                 goto out;
 214
 215         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 216                 goto out;
 217
 218         buf_size = 1;
 219         /* Estimate length */
 220         spin_lock_bh(&bat_priv->vis_hash_lock);
 221         for (i = 0; i < hash->size; i++) {
 222                 head = &hash->table[i];
 223
 224                 rcu_read_lock();
 225                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 226                         packet = (struct vis_packet *)info->skb_packet->data;
 227                         entries = (struct vis_info_entry *)
 228                                 ((char *)packet + sizeof(*packet));
 229
 230                         vis_data_insert_interface(packet->vis_orig,
 231                                                   &vis_if_list, true);
 232
 233                         for (j = 0; j < packet->entries; j++) {
 234                                 if (entries[j].quality == 0)
 235                                         continue;
 236                                 if (compare_eth(entries[j].src,
 237                                                 packet->vis_orig))
 238                                         continue;
 239                                 vis_data_insert_interface(entries[j].src,
 240                                                           &vis_if_list,
 241                                                           false);
 242                         }
 243
 244                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 245                                 buf_size += 18 + 26 * packet->entries;
 246
 247                                 /* add primary/secondary records */
 248                                 if (compare_eth(entry->addr, packet->vis_orig))
 249                                         buf_size +=
 250                                           vis_data_count_prim_sec(&vis_if_list);
 251
 252                                 buf_size += 1;
 253                         }
 254
 255                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 256                                                   list) {
 257                                 hlist_del(&entry->list);
 258                                 kfree(entry);
 259                         }
 260                 }
 261                 rcu_read_unlock();
 262         }
 263
 264         buff = kmalloc(buf_size, GFP_ATOMIC);
 265         if (!buff) {
 266                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 267                 ret = -ENOMEM;
 268                 goto out;
 269         }
 270         buff[0] = '\0';
 271         buff_pos = 0;
 272
 273         for (i = 0; i < hash->size; i++) {
 274                 head = &hash->table[i];
 275
 276                 rcu_read_lock();
 277                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 278                         packet = (struct vis_packet *)info->skb_packet->data;
 279                         entries = (struct vis_info_entry *)
 280                                 ((char *)packet + sizeof(*packet));
 281
 282                         vis_data_insert_interface(packet->vis_orig,
 283                                                   &vis_if_list, true);
 284
 285                         for (j = 0; j < packet->entries; j++) {
 286                                 if (entries[j].quality == 0)
 287                                         continue;
 288                                 if (compare_eth(entries[j].src,
 289                                                 packet->vis_orig))
 290                                         continue;
 291                                 vis_data_insert_interface(entries[j].src,
 292                                                           &vis_if_list,
 293                                                           false);
 294                         }
 295
 296                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 297                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 298                                                 entry->addr);
 299
 300                                 for (j = 0; j < packet->entries; j++)
 301                                         buff_pos += vis_data_read_entry(
 302                                                         buff + buff_pos,
 303                                                         &entries[j],
 304                                                         entry->addr,
 305                                                         entry->primary);
 306
 307                                 /* add primary/secondary records */
 308                                 if (compare_eth(entry->addr, packet->vis_orig))
 309                                         buff_pos +=
 310                                          vis_data_read_prim_sec(buff + buff_pos,
 311                                                                 &vis_if_list);
 312
 313                                 buff_pos += sprintf(buff + buff_pos, "\n");
 314                         }
 315
 316                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 317                                                   list) {
 318                                 hlist_del(&entry->list);
 319                                 kfree(entry);
 320                         }
 321                 }
 322                 rcu_read_unlock();
 323         }
 324
 325         spin_unlock_bh(&bat_priv->vis_hash_lock);
 326
 327         seq_printf(seq, "%s", buff);
 328         kfree(buff);
 329
 330 out:
 331         if (primary_if)
 332                 batadv_hardif_free_ref(primary_if);
 333         return ret;
 334 }
 335
 336 /* add the info packet to the send list, if it was not
 337  * already linked in.
 338  */
 339 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 340 {
 341         if (list_empty(&info->send_list)) {
 342                 kref_get(&info->refcount);
 343                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 344         }
 345 }
 346
 347 /* delete the info packet from the send list, if it was
 348  * linked in.
 349  */
 350 static void send_list_del(struct vis_info *info)
 351 {
 352         if (!list_empty(&info->send_list)) {
 353                 list_del_init(&info->send_list);
 354                 kref_put(&info->refcount, free_info);
 355         }
 356 }
 357
 358 /* tries to add one entry to the receive list. */
 359 static void recv_list_add(struct bat_priv *bat_priv,
 360                           struct list_head *recv_list, const char *mac)
 361 {
 362         struct recvlist_node *entry;
 363
 364         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 365         if (!entry)
 366                 return;
 367
 368         memcpy(entry->mac, mac, ETH_ALEN);
 369         spin_lock_bh(&bat_priv->vis_list_lock);
 370         list_add_tail(&entry->list, recv_list);
 371         spin_unlock_bh(&bat_priv->vis_list_lock);
 372 }
 373
 374 /* returns 1 if this mac is in the recv_list */
 375 static int recv_list_is_in(struct bat_priv *bat_priv,
 376                            const struct list_head *recv_list, const char *mac)
 377 {
 378         const struct recvlist_node *entry;
 379
 380         spin_lock_bh(&bat_priv->vis_list_lock);
 381         list_for_each_entry(entry, recv_list, list) {
 382                 if (compare_eth(entry->mac, mac)) {
 383                         spin_unlock_bh(&bat_priv->vis_list_lock);
 384                         return 1;
 385                 }
 386         }
 387         spin_unlock_bh(&bat_priv->vis_list_lock);
 388         return 0;
 389 }
 390
 391 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 392  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 393  * is newer than old entries in the hash.
 394  */
 395 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 396                                    struct vis_packet *vis_packet,
 397                                    int vis_info_len, int *is_new,
 398                                    int make_broadcast)
 399 {
 400         struct vis_info *info, *old_info;
 401         struct vis_packet *search_packet, *old_packet;
 402         struct vis_info search_elem;
 403         struct vis_packet *packet;
 404         int hash_added;
 405
 406         *is_new = 0;
 407         /* sanity check */
 408         if (!bat_priv->vis_hash)
 409                 return NULL;
 410
 411         /* see if the packet is already in vis_hash */
 412         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 413         if (!search_elem.skb_packet)
 414                 return NULL;
 415         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 416                                                      sizeof(*search_packet));
 417
 418         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 419         old_info = vis_hash_find(bat_priv, &search_elem);
 420         kfree_skb(search_elem.skb_packet);
 421
 422         if (old_info) {
 423                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 424                 if (!seq_after(ntohl(vis_packet->seqno),
 425                                ntohl(old_packet->seqno))) {
 426                         if (old_packet->seqno == vis_packet->seqno) {
 427                                 recv_list_add(bat_priv, &old_info->recv_list,
 428                                               vis_packet->sender_orig);
 429                                 return old_info;
 430                         } else {
 431                                 /* newer packet is already in hash. */
 432                                 return NULL;
 433                         }
 434                 }
 435                 /* remove old entry */
 436                 batadv_hash_remove(bat_priv->vis_hash, vis_info_cmp,
 437                                    vis_info_choose, old_info);
 438                 send_list_del(old_info);
 439                 kref_put(&old_info->refcount, free_info);
 440         }
 441
 442         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 443         if (!info)
 444                 return NULL;
 445
 446         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 447                                          ETH_HLEN);
 448         if (!info->skb_packet) {
 449                 kfree(info);
 450                 return NULL;
 451         }
 452         skb_reserve(info->skb_packet, ETH_HLEN);
 453         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 454                                               + vis_info_len);
 455
 456         kref_init(&info->refcount);
 457         INIT_LIST_HEAD(&info->send_list);
 458         INIT_LIST_HEAD(&info->recv_list);
 459         info->first_seen = jiffies;
 460         info->bat_priv = bat_priv;
 461         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 462
 463         /* initialize and add new packet. */
 464         *is_new = 1;
 465
 466         /* Make it a broadcast packet, if required */
 467         if (make_broadcast)
 468                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 469
 470         /* repair if entries is longer than packet. */
 471         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 472                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 473
 474         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 475
 476         /* try to add it */
 477         hash_added = batadv_hash_add(bat_priv->vis_hash, vis_info_cmp,
 478                                      vis_info_choose, info, &info->hash_entry);
 479         if (hash_added != 0) {
 480                 /* did not work (for some reason) */
 481                 kref_put(&info->refcount, free_info);
 482                 info = NULL;
 483         }
 484
 485         return info;
 486 }
 487
 488 /* handle the server sync packet, forward if needed. */
 489 void batadv_receive_server_sync_packet(struct bat_priv *bat_priv,
 490                                        struct vis_packet *vis_packet,
 491                                        int vis_info_len)
 492 {
 493         struct vis_info *info;
 494         int is_new, make_broadcast;
 495         int vis_server = atomic_read(&bat_priv->vis_mode);
 496
 497         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 498
 499         spin_lock_bh(&bat_priv->vis_hash_lock);
 500         info = add_packet(bat_priv, vis_packet, vis_info_len,
 501                           &is_new, make_broadcast);
 502         if (!info)
 503                 goto end;
 504
 505         /* only if we are server ourselves and packet is newer than the one in
 506          * hash.
 507          */
 508         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 509                 send_list_add(bat_priv, info);
 510 end:
 511         spin_unlock_bh(&bat_priv->vis_hash_lock);
 512 }
 513
 514 /* handle an incoming client update packet and schedule forward if needed. */
 515 void batadv_receive_client_update_packet(struct bat_priv *bat_priv,
 516                                          struct vis_packet *vis_packet,
 517                                          int vis_info_len)
 518 {
 519         struct vis_info *info;
 520         struct vis_packet *packet;
 521         int is_new;
 522         int vis_server = atomic_read(&bat_priv->vis_mode);
 523         int are_target = 0;
 524
 525         /* clients shall not broadcast. */
 526         if (is_broadcast_ether_addr(vis_packet->target_orig))
 527                 return;
 528
 529         /* Are we the target for this VIS packet? */
 530         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 531             batadv_is_my_mac(vis_packet->target_orig))
 532                 are_target = 1;
 533
 534         spin_lock_bh(&bat_priv->vis_hash_lock);
 535         info = add_packet(bat_priv, vis_packet, vis_info_len,
 536                           &is_new, are_target);
 537
 538         if (!info)
 539                 goto end;
 540         /* note that outdated packets will be dropped at this point. */
 541
 542         packet = (struct vis_packet *)info->skb_packet->data;
 543
 544         /* send only if we're the target server or ... */
 545         if (are_target && is_new) {
 546                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 547                 send_list_add(bat_priv, info);
 548
 549                 /* ... we're not the recipient (and thus need to forward). */
 550         } else if (!batadv_is_my_mac(packet->target_orig)) {
 551                 send_list_add(bat_priv, info);
 552         }
 553
 554 end:
 555         spin_unlock_bh(&bat_priv->vis_hash_lock);
 556 }
 557
 558 /* Walk the originators and find the VIS server with the best tq. Set the packet
 559  * address to its address and return the best_tq.
 560  *
 561  * Must be called with the originator hash locked
 562  */
 563 static int find_best_vis_server(struct bat_priv *bat_priv,
 564                                 struct vis_info *info)
 565 {
 566         struct hashtable_t *hash = bat_priv->orig_hash;
 567         struct neigh_node *router;
 568         struct hlist_node *node;
 569         struct hlist_head *head;
 570         struct orig_node *orig_node;
 571         struct vis_packet *packet;
 572         int best_tq = -1;
 573         uint32_t i;
 574
 575         packet = (struct vis_packet *)info->skb_packet->data;
 576
 577         for (i = 0; i < hash->size; i++) {
 578                 head = &hash->table[i];
 579
 580                 rcu_read_lock();
 581                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 582                         router = batadv_orig_node_get_router(orig_node);
 583                         if (!router)
 584                                 continue;
 585
 586                         if ((orig_node->flags & VIS_SERVER) &&
 587                             (router->tq_avg > best_tq)) {
 588                                 best_tq = router->tq_avg;
 589                                 memcpy(packet->target_orig, orig_node->orig,
 590                                        ETH_ALEN);
 591                         }
 592                         batadv_neigh_node_free_ref(router);
 593                 }
 594                 rcu_read_unlock();
 595         }
 596
 597         return best_tq;
 598 }
 599
 600 /* Return true if the vis packet is full. */
 601 static bool vis_packet_full(const struct vis_info *info)
 602 {
 603         const struct vis_packet *packet;
 604         packet = (struct vis_packet *)info->skb_packet->data;
 605
 606         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 607                 < packet->entries + 1)
 608                 return true;
 609         return false;
 610 }
 611
 612 /* generates a packet of own vis data,
 613  * returns 0 on success, -1 if no packet could be generated
 614  */
 615 static int generate_vis_packet(struct bat_priv *bat_priv)
 616 {
 617         struct hashtable_t *hash = bat_priv->orig_hash;
 618         struct hlist_node *node;
 619         struct hlist_head *head;
 620         struct orig_node *orig_node;
 621         struct neigh_node *router;
 622         struct vis_info *info = bat_priv->my_vis_info;
 623         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 624         struct vis_info_entry *entry;
 625         struct tt_common_entry *tt_common_entry;
 626         int best_tq = -1;
 627         uint32_t i;
 628
 629         info->first_seen = jiffies;
 630         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 631
 632         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 633         packet->header.ttl = TTL;
 634         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 635         packet->entries = 0;
 636         skb_trim(info->skb_packet, sizeof(*packet));
 637
 638         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 639                 best_tq = find_best_vis_server(bat_priv, info);
 640
 641                 if (best_tq < 0)
 642                         return best_tq;
 643         }
 644
 645         for (i = 0; i < hash->size; i++) {
 646                 head = &hash->table[i];
 647
 648                 rcu_read_lock();
 649                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 650                         router = batadv_orig_node_get_router(orig_node);
 651                         if (!router)
 652                                 continue;
 653
 654                         if (!compare_eth(router->addr, orig_node->orig))
 655                                 goto next;
 656
 657                         if (router->if_incoming->if_status != IF_ACTIVE)
 658                                 goto next;
 659
 660                         if (router->tq_avg < 1)
 661                                 goto next;
 662
 663                         /* fill one entry into buffer. */
 664                         entry = (struct vis_info_entry *)
 665                                       skb_put(info->skb_packet, sizeof(*entry));
 666                         memcpy(entry->src,
 667                                router->if_incoming->net_dev->dev_addr,
 668                                ETH_ALEN);
 669                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 670                         entry->quality = router->tq_avg;
 671                         packet->entries++;
 672
 673 next:
 674                         batadv_neigh_node_free_ref(router);
 675
 676                         if (vis_packet_full(info))
 677                                 goto unlock;
 678                 }
 679                 rcu_read_unlock();
 680         }
 681
 682         hash = bat_priv->tt_local_hash;
 683
 684         for (i = 0; i < hash->size; i++) {
 685                 head = &hash->table[i];
 686
 687                 rcu_read_lock();
 688                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 689                                          hash_entry) {
 690                         entry = (struct vis_info_entry *)
 691                                         skb_put(info->skb_packet,
 692                                                 sizeof(*entry));
 693                         memset(entry->src, 0, ETH_ALEN);
 694                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 695                         entry->quality = 0; /* 0 means TT */
 696                         packet->entries++;
 697
 698                         if (vis_packet_full(info))
 699                                 goto unlock;
 700                 }
 701                 rcu_read_unlock();
 702         }
 703
 704         return 0;
 705
 706 unlock:
 707         rcu_read_unlock();
 708         return 0;
 709 }
 710
 711 /* free old vis packets. Must be called with this vis_hash_lock
 712  * held
 713  */
 714 static void purge_vis_packets(struct bat_priv *bat_priv)
 715 {
 716         uint32_t i;
 717         struct hashtable_t *hash = bat_priv->vis_hash;
 718         struct hlist_node *node, *node_tmp;
 719         struct hlist_head *head;
 720         struct vis_info *info;
 721
 722         for (i = 0; i < hash->size; i++) {
 723                 head = &hash->table[i];
 724
 725                 hlist_for_each_entry_safe(info, node, node_tmp,
 726                                           head, hash_entry) {
 727                         /* never purge own data. */
 728                         if (info == bat_priv->my_vis_info)
 729                                 continue;
 730
 731                         if (has_timed_out(info->first_seen, VIS_TIMEOUT)) {
 732                                 hlist_del(node);
 733                                 send_list_del(info);
 734                                 kref_put(&info->refcount, free_info);
 735                         }
 736                 }
 737         }
 738 }
 739
 740 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 741                                  struct vis_info *info)
 742 {
 743         struct neigh_node *router;
 744         struct hashtable_t *hash = bat_priv->orig_hash;
 745         struct hlist_node *node;
 746         struct hlist_head *head;
 747         struct orig_node *orig_node;
 748         struct vis_packet *packet;
 749         struct sk_buff *skb;
 750         struct hard_iface *hard_iface;
 751         uint8_t dstaddr[ETH_ALEN];
 752         uint32_t i;
 753
 754
 755         packet = (struct vis_packet *)info->skb_packet->data;
 756
 757         /* send to all routers in range. */
 758         for (i = 0; i < hash->size; i++) {
 759                 head = &hash->table[i];
 760
 761                 rcu_read_lock();
 762                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 763                         /* if it's a vis server and reachable, send it. */
 764                         if (!(orig_node->flags & VIS_SERVER))
 765                                 continue;
 766
 767                         router = batadv_orig_node_get_router(orig_node);
 768                         if (!router)
 769                                 continue;
 770
 771                         /* don't send it if we already received the packet from
 772                          * this node.
 773                          */
 774                         if (recv_list_is_in(bat_priv, &info->recv_list,
 775                                             orig_node->orig)) {
 776                                 batadv_neigh_node_free_ref(router);
 777                                 continue;
 778                         }
 779
 780                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 781                         hard_iface = router->if_incoming;
 782                         memcpy(dstaddr, router->addr, ETH_ALEN);
 783
 784                         batadv_neigh_node_free_ref(router);
 785
 786                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 787                         if (skb)
 788                                 batadv_send_skb_packet(skb, hard_iface,
 789                                                        dstaddr);
 790
 791                 }
 792                 rcu_read_unlock();
 793         }
 794 }
 795
 796 static void unicast_vis_packet(struct bat_priv *bat_priv,
 797                                struct vis_info *info)
 798 {
 799         struct orig_node *orig_node;
 800         struct neigh_node *router = NULL;
 801         struct sk_buff *skb;
 802         struct vis_packet *packet;
 803
 804         packet = (struct vis_packet *)info->skb_packet->data;
 805
 806         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 807         if (!orig_node)
 808                 goto out;
 809
 810         router = batadv_orig_node_get_router(orig_node);
 811         if (!router)
 812                 goto out;
 813
 814         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 815         if (skb)
 816                 batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 817
 818 out:
 819         if (router)
 820                 batadv_neigh_node_free_ref(router);
 821         if (orig_node)
 822                 batadv_orig_node_free_ref(orig_node);
 823 }
 824
 825 /* only send one vis packet. called from send_vis_packets() */
 826 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 827 {
 828         struct hard_iface *primary_if;
 829         struct vis_packet *packet;
 830
 831         primary_if = batadv_primary_if_get_selected(bat_priv);
 832         if (!primary_if)
 833                 goto out;
 834
 835         packet = (struct vis_packet *)info->skb_packet->data;
 836         if (packet->header.ttl < 2) {
 837                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 838                 goto out;
 839         }
 840
 841         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 842         packet->header.ttl--;
 843
 844         if (is_broadcast_ether_addr(packet->target_orig))
 845                 broadcast_vis_packet(bat_priv, info);
 846         else
 847                 unicast_vis_packet(bat_priv, info);
 848         packet->header.ttl++; /* restore TTL */
 849
 850 out:
 851         if (primary_if)
 852                 batadv_hardif_free_ref(primary_if);
 853 }
 854
 855 /* called from timer; send (and maybe generate) vis packet. */
 856 static void send_vis_packets(struct work_struct *work)
 857 {
 858         struct delayed_work *delayed_work =
 859                 container_of(work, struct delayed_work, work);
 860         struct bat_priv *bat_priv =
 861                 container_of(delayed_work, struct bat_priv, vis_work);
 862         struct vis_info *info;
 863
 864         spin_lock_bh(&bat_priv->vis_hash_lock);
 865         purge_vis_packets(bat_priv);
 866
 867         if (generate_vis_packet(bat_priv) == 0) {
 868                 /* schedule if generation was successful */
 869                 send_list_add(bat_priv, bat_priv->my_vis_info);
 870         }
 871
 872         while (!list_empty(&bat_priv->vis_send_list)) {
 873                 info = list_first_entry(&bat_priv->vis_send_list,
 874                                         typeof(*info), send_list);
 875
 876                 kref_get(&info->refcount);
 877                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 878
 879                 send_vis_packet(bat_priv, info);
 880
 881                 spin_lock_bh(&bat_priv->vis_hash_lock);
 882                 send_list_del(info);
 883                 kref_put(&info->refcount, free_info);
 884         }
 885         spin_unlock_bh(&bat_priv->vis_hash_lock);
 886         start_vis_timer(bat_priv);
 887 }
 888
 889 /* init the vis server. this may only be called when if_list is already
 890  * initialized (e.g. bat0 is initialized, interfaces have been added)
 891  */
 892 int batadv_vis_init(struct bat_priv *bat_priv)
 893 {
 894         struct vis_packet *packet;
 895         int hash_added;
 896
 897         if (bat_priv->vis_hash)
 898                 return 0;
 899
 900         spin_lock_bh(&bat_priv->vis_hash_lock);
 901
 902         bat_priv->vis_hash = batadv_hash_new(256);
 903         if (!bat_priv->vis_hash) {
 904                 pr_err("Can't initialize vis_hash\n");
 905                 goto err;
 906         }
 907
 908         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 909         if (!bat_priv->my_vis_info)
 910                 goto err;
 911
 912         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 913                                                           MAX_VIS_PACKET_SIZE +
 914                                                           ETH_HLEN);
 915         if (!bat_priv->my_vis_info->skb_packet)
 916                 goto free_info;
 917
 918         skb_reserve(bat_priv->my_vis_info->skb_packet, ETH_HLEN);
 919         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 920                                               sizeof(*packet));
 921
 922         /* prefill the vis info */
 923         bat_priv->my_vis_info->first_seen = jiffies -
 924                                                 msecs_to_jiffies(VIS_INTERVAL);
 925         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 926         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 927         kref_init(&bat_priv->my_vis_info->refcount);
 928         bat_priv->my_vis_info->bat_priv = bat_priv;
 929         packet->header.version = COMPAT_VERSION;
 930         packet->header.packet_type = BAT_VIS;
 931         packet->header.ttl = TTL;
 932         packet->seqno = 0;
 933         packet->entries = 0;
 934
 935         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 936
 937         hash_added = batadv_hash_add(bat_priv->vis_hash, vis_info_cmp,
 938                                      vis_info_choose, bat_priv->my_vis_info,
 939                                      &bat_priv->my_vis_info->hash_entry);
 940         if (hash_added != 0) {
 941                 pr_err("Can't add own vis packet into hash\n");
 942                 /* not in hash, need to remove it manually. */
 943                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 944                 goto err;
 945         }
 946
 947         spin_unlock_bh(&bat_priv->vis_hash_lock);
 948         start_vis_timer(bat_priv);
 949         return 0;
 950
 951 free_info:
 952         kfree(bat_priv->my_vis_info);
 953         bat_priv->my_vis_info = NULL;
 954 err:
 955         spin_unlock_bh(&bat_priv->vis_hash_lock);
 956         batadv_vis_quit(bat_priv);
 957         return -ENOMEM;
 958 }
 959
 960 /* Decrease the reference count on a hash item info */
 961 static void free_info_ref(struct hlist_node *node, void *arg)
 962 {
 963         struct vis_info *info;
 964
 965         info = container_of(node, struct vis_info, hash_entry);
 966         send_list_del(info);
 967         kref_put(&info->refcount, free_info);
 968 }
 969
 970 /* shutdown vis-server */
 971 void batadv_vis_quit(struct bat_priv *bat_priv)
 972 {
 973         if (!bat_priv->vis_hash)
 974                 return;
 975
 976         cancel_delayed_work_sync(&bat_priv->vis_work);
 977
 978         spin_lock_bh(&bat_priv->vis_hash_lock);
 979         /* properly remove, kill timers ... */
 980         batadv_hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 981         bat_priv->vis_hash = NULL;
 982         bat_priv->my_vis_info = NULL;
 983         spin_unlock_bh(&bat_priv->vis_hash_lock);
 984 }
 985
 986 /* schedule packets for (re)transmission */
 987 static void start_vis_timer(struct bat_priv *bat_priv)
 988 {
 989         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 990         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis_work,
 991                            msecs_to_jiffies(VIS_INTERVAL));
 992 }