net/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2012 B.A.T.M.A.N. contributors:
   3  *
   4  * Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "translation-table.h"
  25 #include "vis.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "hash.h"
  29 #include "originator.h"
  30
  31 #define MAX_VIS_PACKET_SIZE 1000
  32
  33 static void start_vis_timer(struct bat_priv *bat_priv);
  34
  35 /* free the info */
  36 static void free_info(struct kref *ref)
  37 {
  38         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  39         struct bat_priv *bat_priv = info->bat_priv;
  40         struct recvlist_node *entry, *tmp;
  41
  42         list_del_init(&info->send_list);
  43         spin_lock_bh(&bat_priv->vis_list_lock);
  44         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  45                 list_del(&entry->list);
  46                 kfree(entry);
  47         }
  48
  49         spin_unlock_bh(&bat_priv->vis_list_lock);
  50         kfree_skb(info->skb_packet);
  51         kfree(info);
  52 }
  53
  54 /* Compare two vis packets, used by the hashing algorithm */
  55 static int vis_info_cmp(const struct hlist_node *node, const void *data2)
  56 {
  57         const struct vis_info *d1, *d2;
  58         const struct vis_packet *p1, *p2;
  59
  60         d1 = container_of(node, struct vis_info, hash_entry);
  61         d2 = data2;
  62         p1 = (struct vis_packet *)d1->skb_packet->data;
  63         p2 = (struct vis_packet *)d2->skb_packet->data;
  64         return compare_eth(p1->vis_orig, p2->vis_orig);
  65 }
  66
  67 /* hash function to choose an entry in a hash table of given size */
  68 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  69 static uint32_t vis_info_choose(const void *data, uint32_t size)
  70 {
  71         const struct vis_info *vis_info = data;
  72         const struct vis_packet *packet;
  73         const unsigned char *key;
  74         uint32_t hash = 0;
  75         size_t i;
  76
  77         packet = (struct vis_packet *)vis_info->skb_packet->data;
  78         key = packet->vis_orig;
  79         for (i = 0; i < ETH_ALEN; i++) {
  80                 hash += key[i];
  81                 hash += (hash << 10);
  82                 hash ^= (hash >> 6);
  83         }
  84
  85         hash += (hash << 3);
  86         hash ^= (hash >> 11);
  87         hash += (hash << 15);
  88
  89         return hash % size;
  90 }
  91
  92 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
  93                                       const void *data)
  94 {
  95         struct hashtable_t *hash = bat_priv->vis_hash;
  96         struct hlist_head *head;
  97         struct hlist_node *node;
  98         struct vis_info *vis_info, *vis_info_tmp = NULL;
  99         uint32_t index;
 100
 101         if (!hash)
 102                 return NULL;
 103
 104         index = vis_info_choose(data, hash->size);
 105         head = &hash->table[index];
 106
 107         rcu_read_lock();
 108         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 109                 if (!vis_info_cmp(node, data))
 110                         continue;
 111
 112                 vis_info_tmp = vis_info;
 113                 break;
 114         }
 115         rcu_read_unlock();
 116
 117         return vis_info_tmp;
 118 }
 119
 120 /* insert interface to the list of interfaces of one originator, if it
 121  * does not already exist in the list */
 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 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 = 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                 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 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 339 {
 340         if (list_empty(&info->send_list)) {
 341                 kref_get(&info->refcount);
 342                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 343         }
 344 }
 345
 346 /* delete the info packet from the send list, if it was
 347  * linked in. */
 348 static void send_list_del(struct vis_info *info)
 349 {
 350         if (!list_empty(&info->send_list)) {
 351                 list_del_init(&info->send_list);
 352                 kref_put(&info->refcount, free_info);
 353         }
 354 }
 355
 356 /* tries to add one entry to the receive list. */
 357 static void recv_list_add(struct bat_priv *bat_priv,
 358                           struct list_head *recv_list, const char *mac)
 359 {
 360         struct recvlist_node *entry;
 361
 362         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 363         if (!entry)
 364                 return;
 365
 366         memcpy(entry->mac, mac, ETH_ALEN);
 367         spin_lock_bh(&bat_priv->vis_list_lock);
 368         list_add_tail(&entry->list, recv_list);
 369         spin_unlock_bh(&bat_priv->vis_list_lock);
 370 }
 371
 372 /* returns 1 if this mac is in the recv_list */
 373 static int recv_list_is_in(struct bat_priv *bat_priv,
 374                            const struct list_head *recv_list, const char *mac)
 375 {
 376         const struct recvlist_node *entry;
 377
 378         spin_lock_bh(&bat_priv->vis_list_lock);
 379         list_for_each_entry(entry, recv_list, list) {
 380                 if (compare_eth(entry->mac, mac)) {
 381                         spin_unlock_bh(&bat_priv->vis_list_lock);
 382                         return 1;
 383                 }
 384         }
 385         spin_unlock_bh(&bat_priv->vis_list_lock);
 386         return 0;
 387 }
 388
 389 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 390  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 391  * is newer than old entries in the hash. */
 392 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 393                                    struct vis_packet *vis_packet,
 394                                    int vis_info_len, int *is_new,
 395                                    int make_broadcast)
 396 {
 397         struct vis_info *info, *old_info;
 398         struct vis_packet *search_packet, *old_packet;
 399         struct vis_info search_elem;
 400         struct vis_packet *packet;
 401         int hash_added;
 402
 403         *is_new = 0;
 404         /* sanity check */
 405         if (!bat_priv->vis_hash)
 406                 return NULL;
 407
 408         /* see if the packet is already in vis_hash */
 409         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 410         if (!search_elem.skb_packet)
 411                 return NULL;
 412         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 413                                                      sizeof(*search_packet));
 414
 415         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 416         old_info = vis_hash_find(bat_priv, &search_elem);
 417         kfree_skb(search_elem.skb_packet);
 418
 419         if (old_info) {
 420                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 421                 if (!seq_after(ntohl(vis_packet->seqno),
 422                                ntohl(old_packet->seqno))) {
 423                         if (old_packet->seqno == vis_packet->seqno) {
 424                                 recv_list_add(bat_priv, &old_info->recv_list,
 425                                               vis_packet->sender_orig);
 426                                 return old_info;
 427                         } else {
 428                                 /* newer packet is already in hash. */
 429                                 return NULL;
 430                         }
 431                 }
 432                 /* remove old entry */
 433                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 434                             old_info);
 435                 send_list_del(old_info);
 436                 kref_put(&old_info->refcount, free_info);
 437         }
 438
 439         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 440         if (!info)
 441                 return NULL;
 442
 443         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 444                                          ETH_HLEN);
 445         if (!info->skb_packet) {
 446                 kfree(info);
 447                 return NULL;
 448         }
 449         skb_reserve(info->skb_packet, ETH_HLEN);
 450         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 451                                               + vis_info_len);
 452
 453         kref_init(&info->refcount);
 454         INIT_LIST_HEAD(&info->send_list);
 455         INIT_LIST_HEAD(&info->recv_list);
 456         info->first_seen = jiffies;
 457         info->bat_priv = bat_priv;
 458         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 459
 460         /* initialize and add new packet. */
 461         *is_new = 1;
 462
 463         /* Make it a broadcast packet, if required */
 464         if (make_broadcast)
 465                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 466
 467         /* repair if entries is longer than packet. */
 468         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 469                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 470
 471         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 472
 473         /* try to add it */
 474         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 475                               info, &info->hash_entry);
 476         if (hash_added != 0) {
 477                 /* did not work (for some reason) */
 478                 kref_put(&info->refcount, free_info);
 479                 info = NULL;
 480         }
 481
 482         return info;
 483 }
 484
 485 /* handle the server sync packet, forward if needed. */
 486 void receive_server_sync_packet(struct bat_priv *bat_priv,
 487                                 struct vis_packet *vis_packet,
 488                                 int vis_info_len)
 489 {
 490         struct vis_info *info;
 491         int is_new, make_broadcast;
 492         int vis_server = atomic_read(&bat_priv->vis_mode);
 493
 494         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 495
 496         spin_lock_bh(&bat_priv->vis_hash_lock);
 497         info = add_packet(bat_priv, vis_packet, vis_info_len,
 498                           &is_new, make_broadcast);
 499         if (!info)
 500                 goto end;
 501
 502         /* only if we are server ourselves and packet is newer than the one in
 503          * hash.*/
 504         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 505                 send_list_add(bat_priv, info);
 506 end:
 507         spin_unlock_bh(&bat_priv->vis_hash_lock);
 508 }
 509
 510 /* handle an incoming client update packet and schedule forward if needed. */
 511 void receive_client_update_packet(struct bat_priv *bat_priv,
 512                                   struct vis_packet *vis_packet,
 513                                   int vis_info_len)
 514 {
 515         struct vis_info *info;
 516         struct vis_packet *packet;
 517         int is_new;
 518         int vis_server = atomic_read(&bat_priv->vis_mode);
 519         int are_target = 0;
 520
 521         /* clients shall not broadcast. */
 522         if (is_broadcast_ether_addr(vis_packet->target_orig))
 523                 return;
 524
 525         /* Are we the target for this VIS packet? */
 526         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 527             is_my_mac(vis_packet->target_orig))
 528                 are_target = 1;
 529
 530         spin_lock_bh(&bat_priv->vis_hash_lock);
 531         info = add_packet(bat_priv, vis_packet, vis_info_len,
 532                           &is_new, are_target);
 533
 534         if (!info)
 535                 goto end;
 536         /* note that outdated packets will be dropped at this point. */
 537
 538         packet = (struct vis_packet *)info->skb_packet->data;
 539
 540         /* send only if we're the target server or ... */
 541         if (are_target && is_new) {
 542                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 543                 send_list_add(bat_priv, info);
 544
 545                 /* ... we're not the recipient (and thus need to forward). */
 546         } else if (!is_my_mac(packet->target_orig)) {
 547                 send_list_add(bat_priv, info);
 548         }
 549
 550 end:
 551         spin_unlock_bh(&bat_priv->vis_hash_lock);
 552 }
 553
 554 /* Walk the originators and find the VIS server with the best tq. Set the packet
 555  * address to its address and return the best_tq.
 556  *
 557  * Must be called with the originator hash locked */
 558 static int find_best_vis_server(struct bat_priv *bat_priv,
 559                                 struct vis_info *info)
 560 {
 561         struct hashtable_t *hash = bat_priv->orig_hash;
 562         struct neigh_node *router;
 563         struct hlist_node *node;
 564         struct hlist_head *head;
 565         struct orig_node *orig_node;
 566         struct vis_packet *packet;
 567         int best_tq = -1;
 568         uint32_t i;
 569
 570         packet = (struct vis_packet *)info->skb_packet->data;
 571
 572         for (i = 0; i < hash->size; i++) {
 573                 head = &hash->table[i];
 574
 575                 rcu_read_lock();
 576                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 577                         router = orig_node_get_router(orig_node);
 578                         if (!router)
 579                                 continue;
 580
 581                         if ((orig_node->flags & VIS_SERVER) &&
 582                             (router->tq_avg > best_tq)) {
 583                                 best_tq = router->tq_avg;
 584                                 memcpy(packet->target_orig, orig_node->orig,
 585                                        ETH_ALEN);
 586                         }
 587                         neigh_node_free_ref(router);
 588                 }
 589                 rcu_read_unlock();
 590         }
 591
 592         return best_tq;
 593 }
 594
 595 /* Return true if the vis packet is full. */
 596 static bool vis_packet_full(const struct vis_info *info)
 597 {
 598         const struct vis_packet *packet;
 599         packet = (struct vis_packet *)info->skb_packet->data;
 600
 601         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 602                 < packet->entries + 1)
 603                 return true;
 604         return false;
 605 }
 606
 607 /* generates a packet of own vis data,
 608  * returns 0 on success, -1 if no packet could be generated */
 609 static int generate_vis_packet(struct bat_priv *bat_priv)
 610 {
 611         struct hashtable_t *hash = bat_priv->orig_hash;
 612         struct hlist_node *node;
 613         struct hlist_head *head;
 614         struct orig_node *orig_node;
 615         struct neigh_node *router;
 616         struct vis_info *info = bat_priv->my_vis_info;
 617         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 618         struct vis_info_entry *entry;
 619         struct tt_common_entry *tt_common_entry;
 620         int best_tq = -1;
 621         uint32_t i;
 622
 623         info->first_seen = jiffies;
 624         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 625
 626         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 627         packet->header.ttl = TTL;
 628         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 629         packet->entries = 0;
 630         skb_trim(info->skb_packet, sizeof(*packet));
 631
 632         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 633                 best_tq = find_best_vis_server(bat_priv, info);
 634
 635                 if (best_tq < 0)
 636                         return best_tq;
 637         }
 638
 639         for (i = 0; i < hash->size; i++) {
 640                 head = &hash->table[i];
 641
 642                 rcu_read_lock();
 643                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 644                         router = orig_node_get_router(orig_node);
 645                         if (!router)
 646                                 continue;
 647
 648                         if (!compare_eth(router->addr, orig_node->orig))
 649                                 goto next;
 650
 651                         if (router->if_incoming->if_status != IF_ACTIVE)
 652                                 goto next;
 653
 654                         if (router->tq_avg < 1)
 655                                 goto next;
 656
 657                         /* fill one entry into buffer. */
 658                         entry = (struct vis_info_entry *)
 659                                       skb_put(info->skb_packet, sizeof(*entry));
 660                         memcpy(entry->src,
 661                                router->if_incoming->net_dev->dev_addr,
 662                                ETH_ALEN);
 663                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 664                         entry->quality = router->tq_avg;
 665                         packet->entries++;
 666
 667 next:
 668                         neigh_node_free_ref(router);
 669
 670                         if (vis_packet_full(info))
 671                                 goto unlock;
 672                 }
 673                 rcu_read_unlock();
 674         }
 675
 676         hash = bat_priv->tt_local_hash;
 677
 678         for (i = 0; i < hash->size; i++) {
 679                 head = &hash->table[i];
 680
 681                 rcu_read_lock();
 682                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 683                                          hash_entry) {
 684                         entry = (struct vis_info_entry *)
 685                                         skb_put(info->skb_packet,
 686                                                 sizeof(*entry));
 687                         memset(entry->src, 0, ETH_ALEN);
 688                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 689                         entry->quality = 0; /* 0 means TT */
 690                         packet->entries++;
 691
 692                         if (vis_packet_full(info))
 693                                 goto unlock;
 694                 }
 695                 rcu_read_unlock();
 696         }
 697
 698         return 0;
 699
 700 unlock:
 701         rcu_read_unlock();
 702         return 0;
 703 }
 704
 705 /* free old vis packets. Must be called with this vis_hash_lock
 706  * held */
 707 static void purge_vis_packets(struct bat_priv *bat_priv)
 708 {
 709         uint32_t i;
 710         struct hashtable_t *hash = bat_priv->vis_hash;
 711         struct hlist_node *node, *node_tmp;
 712         struct hlist_head *head;
 713         struct vis_info *info;
 714
 715         for (i = 0; i < hash->size; i++) {
 716                 head = &hash->table[i];
 717
 718                 hlist_for_each_entry_safe(info, node, node_tmp,
 719                                           head, hash_entry) {
 720                         /* never purge own data. */
 721                         if (info == bat_priv->my_vis_info)
 722                                 continue;
 723
 724                         if (has_timed_out(info->first_seen, VIS_TIMEOUT)) {
 725                                 hlist_del(node);
 726                                 send_list_del(info);
 727                                 kref_put(&info->refcount, free_info);
 728                         }
 729                 }
 730         }
 731 }
 732
 733 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 734                                  struct vis_info *info)
 735 {
 736         struct neigh_node *router;
 737         struct hashtable_t *hash = bat_priv->orig_hash;
 738         struct hlist_node *node;
 739         struct hlist_head *head;
 740         struct orig_node *orig_node;
 741         struct vis_packet *packet;
 742         struct sk_buff *skb;
 743         struct hard_iface *hard_iface;
 744         uint8_t dstaddr[ETH_ALEN];
 745         uint32_t i;
 746
 747
 748         packet = (struct vis_packet *)info->skb_packet->data;
 749
 750         /* send to all routers in range. */
 751         for (i = 0; i < hash->size; i++) {
 752                 head = &hash->table[i];
 753
 754                 rcu_read_lock();
 755                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 756                         /* if it's a vis server and reachable, send it. */
 757                         if (!(orig_node->flags & VIS_SERVER))
 758                                 continue;
 759
 760                         router = orig_node_get_router(orig_node);
 761                         if (!router)
 762                                 continue;
 763
 764                         /* don't send it if we already received the packet from
 765                          * this node. */
 766                         if (recv_list_is_in(bat_priv, &info->recv_list,
 767                                             orig_node->orig)) {
 768                                 neigh_node_free_ref(router);
 769                                 continue;
 770                         }
 771
 772                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 773                         hard_iface = router->if_incoming;
 774                         memcpy(dstaddr, router->addr, ETH_ALEN);
 775
 776                         neigh_node_free_ref(router);
 777
 778                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 779                         if (skb)
 780                                 send_skb_packet(skb, hard_iface, dstaddr);
 781
 782                 }
 783                 rcu_read_unlock();
 784         }
 785 }
 786
 787 static void unicast_vis_packet(struct bat_priv *bat_priv,
 788                                struct vis_info *info)
 789 {
 790         struct orig_node *orig_node;
 791         struct neigh_node *router = NULL;
 792         struct sk_buff *skb;
 793         struct vis_packet *packet;
 794
 795         packet = (struct vis_packet *)info->skb_packet->data;
 796
 797         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 798         if (!orig_node)
 799                 goto out;
 800
 801         router = orig_node_get_router(orig_node);
 802         if (!router)
 803                 goto out;
 804
 805         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 806         if (skb)
 807                 send_skb_packet(skb, router->if_incoming, router->addr);
 808
 809 out:
 810         if (router)
 811                 neigh_node_free_ref(router);
 812         if (orig_node)
 813                 orig_node_free_ref(orig_node);
 814 }
 815
 816 /* only send one vis packet. called from send_vis_packets() */
 817 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 818 {
 819         struct hard_iface *primary_if;
 820         struct vis_packet *packet;
 821
 822         primary_if = primary_if_get_selected(bat_priv);
 823         if (!primary_if)
 824                 goto out;
 825
 826         packet = (struct vis_packet *)info->skb_packet->data;
 827         if (packet->header.ttl < 2) {
 828                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 829                 goto out;
 830         }
 831
 832         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 833         packet->header.ttl--;
 834
 835         if (is_broadcast_ether_addr(packet->target_orig))
 836                 broadcast_vis_packet(bat_priv, info);
 837         else
 838                 unicast_vis_packet(bat_priv, info);
 839         packet->header.ttl++; /* restore TTL */
 840
 841 out:
 842         if (primary_if)
 843                 hardif_free_ref(primary_if);
 844 }
 845
 846 /* called from timer; send (and maybe generate) vis packet. */
 847 static void send_vis_packets(struct work_struct *work)
 848 {
 849         struct delayed_work *delayed_work =
 850                 container_of(work, struct delayed_work, work);
 851         struct bat_priv *bat_priv =
 852                 container_of(delayed_work, struct bat_priv, vis_work);
 853         struct vis_info *info;
 854
 855         spin_lock_bh(&bat_priv->vis_hash_lock);
 856         purge_vis_packets(bat_priv);
 857
 858         if (generate_vis_packet(bat_priv) == 0) {
 859                 /* schedule if generation was successful */
 860                 send_list_add(bat_priv, bat_priv->my_vis_info);
 861         }
 862
 863         while (!list_empty(&bat_priv->vis_send_list)) {
 864                 info = list_first_entry(&bat_priv->vis_send_list,
 865                                         typeof(*info), send_list);
 866
 867                 kref_get(&info->refcount);
 868                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 869
 870                 send_vis_packet(bat_priv, info);
 871
 872                 spin_lock_bh(&bat_priv->vis_hash_lock);
 873                 send_list_del(info);
 874                 kref_put(&info->refcount, free_info);
 875         }
 876         spin_unlock_bh(&bat_priv->vis_hash_lock);
 877         start_vis_timer(bat_priv);
 878 }
 879
 880 /* init the vis server. this may only be called when if_list is already
 881  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 882 int vis_init(struct bat_priv *bat_priv)
 883 {
 884         struct vis_packet *packet;
 885         int hash_added;
 886
 887         if (bat_priv->vis_hash)
 888                 return 0;
 889
 890         spin_lock_bh(&bat_priv->vis_hash_lock);
 891
 892         bat_priv->vis_hash = batadv_hash_new(256);
 893         if (!bat_priv->vis_hash) {
 894                 pr_err("Can't initialize vis_hash\n");
 895                 goto err;
 896         }
 897
 898         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 899         if (!bat_priv->my_vis_info)
 900                 goto err;
 901
 902         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 903                                                           MAX_VIS_PACKET_SIZE +
 904                                                           ETH_HLEN);
 905         if (!bat_priv->my_vis_info->skb_packet)
 906                 goto free_info;
 907
 908         skb_reserve(bat_priv->my_vis_info->skb_packet, ETH_HLEN);
 909         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 910                                               sizeof(*packet));
 911
 912         /* prefill the vis info */
 913         bat_priv->my_vis_info->first_seen = jiffies -
 914                                                 msecs_to_jiffies(VIS_INTERVAL);
 915         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 916         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 917         kref_init(&bat_priv->my_vis_info->refcount);
 918         bat_priv->my_vis_info->bat_priv = bat_priv;
 919         packet->header.version = COMPAT_VERSION;
 920         packet->header.packet_type = BAT_VIS;
 921         packet->header.ttl = TTL;
 922         packet->seqno = 0;
 923         packet->entries = 0;
 924
 925         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 926
 927         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 928                               bat_priv->my_vis_info,
 929                               &bat_priv->my_vis_info->hash_entry);
 930         if (hash_added != 0) {
 931                 pr_err("Can't add own vis packet into hash\n");
 932                 /* not in hash, need to remove it manually. */
 933                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 934                 goto err;
 935         }
 936
 937         spin_unlock_bh(&bat_priv->vis_hash_lock);
 938         start_vis_timer(bat_priv);
 939         return 0;
 940
 941 free_info:
 942         kfree(bat_priv->my_vis_info);
 943         bat_priv->my_vis_info = NULL;
 944 err:
 945         spin_unlock_bh(&bat_priv->vis_hash_lock);
 946         vis_quit(bat_priv);
 947         return -ENOMEM;
 948 }
 949
 950 /* Decrease the reference count on a hash item info */
 951 static void free_info_ref(struct hlist_node *node, void *arg)
 952 {
 953         struct vis_info *info;
 954
 955         info = container_of(node, struct vis_info, hash_entry);
 956         send_list_del(info);
 957         kref_put(&info->refcount, free_info);
 958 }
 959
 960 /* shutdown vis-server */
 961 void vis_quit(struct bat_priv *bat_priv)
 962 {
 963         if (!bat_priv->vis_hash)
 964                 return;
 965
 966         cancel_delayed_work_sync(&bat_priv->vis_work);
 967
 968         spin_lock_bh(&bat_priv->vis_hash_lock);
 969         /* properly remove, kill timers ... */
 970         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 971         bat_priv->vis_hash = NULL;
 972         bat_priv->my_vis_info = NULL;
 973         spin_unlock_bh(&bat_priv->vis_hash_lock);
 974 }
 975
 976 /* schedule packets for (re)transmission */
 977 static void start_vis_timer(struct bat_priv *bat_priv)
 978 {
 979         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 980         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 981                            msecs_to_jiffies(VIS_INTERVAL));
 982 }