net/batman-adv/vis.c

   1 /*
   2  * Copyright (C) 2008-2011 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         int compare;
 211
 212         primary_if = primary_if_get_selected(bat_priv);
 213         if (!primary_if)
 214                 goto out;
 215
 216         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 217                 goto out;
 218
 219         buf_size = 1;
 220         /* Estimate length */
 221         spin_lock_bh(&bat_priv->vis_hash_lock);
 222         for (i = 0; i < hash->size; i++) {
 223                 head = &hash->table[i];
 224
 225                 rcu_read_lock();
 226                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 227                         packet = (struct vis_packet *)info->skb_packet->data;
 228                         entries = (struct vis_info_entry *)
 229                                 ((char *)packet + sizeof(*packet));
 230
 231                         for (j = 0; j < packet->entries; j++) {
 232                                 if (entries[j].quality == 0)
 233                                         continue;
 234                                 compare =
 235                                  compare_eth(entries[j].src, packet->vis_orig);
 236                                 vis_data_insert_interface(entries[j].src,
 237                                                           &vis_if_list,
 238                                                           compare);
 239                         }
 240
 241                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 242                                 buf_size += 18 + 26 * packet->entries;
 243
 244                                 /* add primary/secondary records */
 245                                 if (compare_eth(entry->addr, packet->vis_orig))
 246                                         buf_size +=
 247                                           vis_data_count_prim_sec(&vis_if_list);
 248
 249                                 buf_size += 1;
 250                         }
 251
 252                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 253                                                   list) {
 254                                 hlist_del(&entry->list);
 255                                 kfree(entry);
 256                         }
 257                 }
 258                 rcu_read_unlock();
 259         }
 260
 261         buff = kmalloc(buf_size, GFP_ATOMIC);
 262         if (!buff) {
 263                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 264                 ret = -ENOMEM;
 265                 goto out;
 266         }
 267         buff[0] = '\0';
 268         buff_pos = 0;
 269
 270         for (i = 0; i < hash->size; i++) {
 271                 head = &hash->table[i];
 272
 273                 rcu_read_lock();
 274                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 275                         packet = (struct vis_packet *)info->skb_packet->data;
 276                         entries = (struct vis_info_entry *)
 277                                 ((char *)packet + sizeof(*packet));
 278
 279                         for (j = 0; j < packet->entries; j++) {
 280                                 if (entries[j].quality == 0)
 281                                         continue;
 282                                 compare =
 283                                  compare_eth(entries[j].src, packet->vis_orig);
 284                                 vis_data_insert_interface(entries[j].src,
 285                                                           &vis_if_list,
 286                                                           compare);
 287                         }
 288
 289                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 290                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 291                                                 entry->addr);
 292
 293                                 for (j = 0; j < packet->entries; j++)
 294                                         buff_pos += vis_data_read_entry(
 295                                                         buff + buff_pos,
 296                                                         &entries[j],
 297                                                         entry->addr,
 298                                                         entry->primary);
 299
 300                                 /* add primary/secondary records */
 301                                 if (compare_eth(entry->addr, packet->vis_orig))
 302                                         buff_pos +=
 303                                          vis_data_read_prim_sec(buff + buff_pos,
 304                                                                 &vis_if_list);
 305
 306                                 buff_pos += sprintf(buff + buff_pos, "\n");
 307                         }
 308
 309                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 310                                                   list) {
 311                                 hlist_del(&entry->list);
 312                                 kfree(entry);
 313                         }
 314                 }
 315                 rcu_read_unlock();
 316         }
 317
 318         spin_unlock_bh(&bat_priv->vis_hash_lock);
 319
 320         seq_printf(seq, "%s", buff);
 321         kfree(buff);
 322
 323 out:
 324         if (primary_if)
 325                 hardif_free_ref(primary_if);
 326         return ret;
 327 }
 328
 329 /* add the info packet to the send list, if it was not
 330  * already linked in. */
 331 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 332 {
 333         if (list_empty(&info->send_list)) {
 334                 kref_get(&info->refcount);
 335                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 336         }
 337 }
 338
 339 /* delete the info packet from the send list, if it was
 340  * linked in. */
 341 static void send_list_del(struct vis_info *info)
 342 {
 343         if (!list_empty(&info->send_list)) {
 344                 list_del_init(&info->send_list);
 345                 kref_put(&info->refcount, free_info);
 346         }
 347 }
 348
 349 /* tries to add one entry to the receive list. */
 350 static void recv_list_add(struct bat_priv *bat_priv,
 351                           struct list_head *recv_list, const char *mac)
 352 {
 353         struct recvlist_node *entry;
 354
 355         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 356         if (!entry)
 357                 return;
 358
 359         memcpy(entry->mac, mac, ETH_ALEN);
 360         spin_lock_bh(&bat_priv->vis_list_lock);
 361         list_add_tail(&entry->list, recv_list);
 362         spin_unlock_bh(&bat_priv->vis_list_lock);
 363 }
 364
 365 /* returns 1 if this mac is in the recv_list */
 366 static int recv_list_is_in(struct bat_priv *bat_priv,
 367                            const struct list_head *recv_list, const char *mac)
 368 {
 369         const struct recvlist_node *entry;
 370
 371         spin_lock_bh(&bat_priv->vis_list_lock);
 372         list_for_each_entry(entry, recv_list, list) {
 373                 if (compare_eth(entry->mac, mac)) {
 374                         spin_unlock_bh(&bat_priv->vis_list_lock);
 375                         return 1;
 376                 }
 377         }
 378         spin_unlock_bh(&bat_priv->vis_list_lock);
 379         return 0;
 380 }
 381
 382 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 383  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 384  * is newer than old entries in the hash. */
 385 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 386                                    struct vis_packet *vis_packet,
 387                                    int vis_info_len, int *is_new,
 388                                    int make_broadcast)
 389 {
 390         struct vis_info *info, *old_info;
 391         struct vis_packet *search_packet, *old_packet;
 392         struct vis_info search_elem;
 393         struct vis_packet *packet;
 394         int hash_added;
 395
 396         *is_new = 0;
 397         /* sanity check */
 398         if (!bat_priv->vis_hash)
 399                 return NULL;
 400
 401         /* see if the packet is already in vis_hash */
 402         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 403         if (!search_elem.skb_packet)
 404                 return NULL;
 405         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 406                                                      sizeof(*search_packet));
 407
 408         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 409         old_info = vis_hash_find(bat_priv, &search_elem);
 410         kfree_skb(search_elem.skb_packet);
 411
 412         if (old_info) {
 413                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 414                 if (!seq_after(ntohl(vis_packet->seqno),
 415                                ntohl(old_packet->seqno))) {
 416                         if (old_packet->seqno == vis_packet->seqno) {
 417                                 recv_list_add(bat_priv, &old_info->recv_list,
 418                                               vis_packet->sender_orig);
 419                                 return old_info;
 420                         } else {
 421                                 /* newer packet is already in hash. */
 422                                 return NULL;
 423                         }
 424                 }
 425                 /* remove old entry */
 426                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 427                             old_info);
 428                 send_list_del(old_info);
 429                 kref_put(&old_info->refcount, free_info);
 430         }
 431
 432         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 433         if (!info)
 434                 return NULL;
 435
 436         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 437                                          sizeof(struct ethhdr));
 438         if (!info->skb_packet) {
 439                 kfree(info);
 440                 return NULL;
 441         }
 442         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 443         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 444                                               + vis_info_len);
 445
 446         kref_init(&info->refcount);
 447         INIT_LIST_HEAD(&info->send_list);
 448         INIT_LIST_HEAD(&info->recv_list);
 449         info->first_seen = jiffies;
 450         info->bat_priv = bat_priv;
 451         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 452
 453         /* initialize and add new packet. */
 454         *is_new = 1;
 455
 456         /* Make it a broadcast packet, if required */
 457         if (make_broadcast)
 458                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 459
 460         /* repair if entries is longer than packet. */
 461         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 462                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 463
 464         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 465
 466         /* try to add it */
 467         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 468                               info, &info->hash_entry);
 469         if (hash_added != 0) {
 470                 /* did not work (for some reason) */
 471                 kref_put(&info->refcount, free_info);
 472                 info = NULL;
 473         }
 474
 475         return info;
 476 }
 477
 478 /* handle the server sync packet, forward if needed. */
 479 void receive_server_sync_packet(struct bat_priv *bat_priv,
 480                                 struct vis_packet *vis_packet,
 481                                 int vis_info_len)
 482 {
 483         struct vis_info *info;
 484         int is_new, make_broadcast;
 485         int vis_server = atomic_read(&bat_priv->vis_mode);
 486
 487         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 488
 489         spin_lock_bh(&bat_priv->vis_hash_lock);
 490         info = add_packet(bat_priv, vis_packet, vis_info_len,
 491                           &is_new, make_broadcast);
 492         if (!info)
 493                 goto end;
 494
 495         /* only if we are server ourselves and packet is newer than the one in
 496          * hash.*/
 497         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 498                 send_list_add(bat_priv, info);
 499 end:
 500         spin_unlock_bh(&bat_priv->vis_hash_lock);
 501 }
 502
 503 /* handle an incoming client update packet and schedule forward if needed. */
 504 void receive_client_update_packet(struct bat_priv *bat_priv,
 505                                   struct vis_packet *vis_packet,
 506                                   int vis_info_len)
 507 {
 508         struct vis_info *info;
 509         struct vis_packet *packet;
 510         int is_new;
 511         int vis_server = atomic_read(&bat_priv->vis_mode);
 512         int are_target = 0;
 513
 514         /* clients shall not broadcast. */
 515         if (is_broadcast_ether_addr(vis_packet->target_orig))
 516                 return;
 517
 518         /* Are we the target for this VIS packet? */
 519         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 520             is_my_mac(vis_packet->target_orig))
 521                 are_target = 1;
 522
 523         spin_lock_bh(&bat_priv->vis_hash_lock);
 524         info = add_packet(bat_priv, vis_packet, vis_info_len,
 525                           &is_new, are_target);
 526
 527         if (!info)
 528                 goto end;
 529         /* note that outdated packets will be dropped at this point. */
 530
 531         packet = (struct vis_packet *)info->skb_packet->data;
 532
 533         /* send only if we're the target server or ... */
 534         if (are_target && is_new) {
 535                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 536                 send_list_add(bat_priv, info);
 537
 538                 /* ... we're not the recipient (and thus need to forward). */
 539         } else if (!is_my_mac(packet->target_orig)) {
 540                 send_list_add(bat_priv, info);
 541         }
 542
 543 end:
 544         spin_unlock_bh(&bat_priv->vis_hash_lock);
 545 }
 546
 547 /* Walk the originators and find the VIS server with the best tq. Set the packet
 548  * address to its address and return the best_tq.
 549  *
 550  * Must be called with the originator hash locked */
 551 static int find_best_vis_server(struct bat_priv *bat_priv,
 552                                 struct vis_info *info)
 553 {
 554         struct hashtable_t *hash = bat_priv->orig_hash;
 555         struct neigh_node *router;
 556         struct hlist_node *node;
 557         struct hlist_head *head;
 558         struct orig_node *orig_node;
 559         struct vis_packet *packet;
 560         int best_tq = -1;
 561         uint32_t i;
 562
 563         packet = (struct vis_packet *)info->skb_packet->data;
 564
 565         for (i = 0; i < hash->size; i++) {
 566                 head = &hash->table[i];
 567
 568                 rcu_read_lock();
 569                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 570                         router = orig_node_get_router(orig_node);
 571                         if (!router)
 572                                 continue;
 573
 574                         if ((orig_node->flags & VIS_SERVER) &&
 575                             (router->tq_avg > best_tq)) {
 576                                 best_tq = router->tq_avg;
 577                                 memcpy(packet->target_orig, orig_node->orig,
 578                                        ETH_ALEN);
 579                         }
 580                         neigh_node_free_ref(router);
 581                 }
 582                 rcu_read_unlock();
 583         }
 584
 585         return best_tq;
 586 }
 587
 588 /* Return true if the vis packet is full. */
 589 static bool vis_packet_full(const struct vis_info *info)
 590 {
 591         const struct vis_packet *packet;
 592         packet = (struct vis_packet *)info->skb_packet->data;
 593
 594         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 595                 < packet->entries + 1)
 596                 return true;
 597         return false;
 598 }
 599
 600 /* generates a packet of own vis data,
 601  * returns 0 on success, -1 if no packet could be generated */
 602 static int generate_vis_packet(struct bat_priv *bat_priv)
 603 {
 604         struct hashtable_t *hash = bat_priv->orig_hash;
 605         struct hlist_node *node;
 606         struct hlist_head *head;
 607         struct orig_node *orig_node;
 608         struct neigh_node *router;
 609         struct vis_info *info = bat_priv->my_vis_info;
 610         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 611         struct vis_info_entry *entry;
 612         struct tt_common_entry *tt_common_entry;
 613         int best_tq = -1;
 614         uint32_t i;
 615
 616         info->first_seen = jiffies;
 617         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 618
 619         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 620         packet->ttl = TTL;
 621         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 622         packet->entries = 0;
 623         skb_trim(info->skb_packet, sizeof(*packet));
 624
 625         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 626                 best_tq = find_best_vis_server(bat_priv, info);
 627
 628                 if (best_tq < 0)
 629                         return -1;
 630         }
 631
 632         for (i = 0; i < hash->size; i++) {
 633                 head = &hash->table[i];
 634
 635                 rcu_read_lock();
 636                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 637                         router = orig_node_get_router(orig_node);
 638                         if (!router)
 639                                 continue;
 640
 641                         if (!compare_eth(router->addr, orig_node->orig))
 642                                 goto next;
 643
 644                         if (router->if_incoming->if_status != IF_ACTIVE)
 645                                 goto next;
 646
 647                         if (router->tq_avg < 1)
 648                                 goto next;
 649
 650                         /* fill one entry into buffer. */
 651                         entry = (struct vis_info_entry *)
 652                                       skb_put(info->skb_packet, sizeof(*entry));
 653                         memcpy(entry->src,
 654                                router->if_incoming->net_dev->dev_addr,
 655                                ETH_ALEN);
 656                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 657                         entry->quality = router->tq_avg;
 658                         packet->entries++;
 659
 660 next:
 661                         neigh_node_free_ref(router);
 662
 663                         if (vis_packet_full(info))
 664                                 goto unlock;
 665                 }
 666                 rcu_read_unlock();
 667         }
 668
 669         hash = bat_priv->tt_local_hash;
 670
 671         for (i = 0; i < hash->size; i++) {
 672                 head = &hash->table[i];
 673
 674                 rcu_read_lock();
 675                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 676                                          hash_entry) {
 677                         entry = (struct vis_info_entry *)
 678                                         skb_put(info->skb_packet,
 679                                                 sizeof(*entry));
 680                         memset(entry->src, 0, ETH_ALEN);
 681                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 682                         entry->quality = 0; /* 0 means TT */
 683                         packet->entries++;
 684
 685                         if (vis_packet_full(info))
 686                                 goto unlock;
 687                 }
 688                 rcu_read_unlock();
 689         }
 690
 691         return 0;
 692
 693 unlock:
 694         rcu_read_unlock();
 695         return 0;
 696 }
 697
 698 /* free old vis packets. Must be called with this vis_hash_lock
 699  * held */
 700 static void purge_vis_packets(struct bat_priv *bat_priv)
 701 {
 702         uint32_t i;
 703         struct hashtable_t *hash = bat_priv->vis_hash;
 704         struct hlist_node *node, *node_tmp;
 705         struct hlist_head *head;
 706         struct vis_info *info;
 707
 708         for (i = 0; i < hash->size; i++) {
 709                 head = &hash->table[i];
 710
 711                 hlist_for_each_entry_safe(info, node, node_tmp,
 712                                           head, hash_entry) {
 713                         /* never purge own data. */
 714                         if (info == bat_priv->my_vis_info)
 715                                 continue;
 716
 717                         if (time_after(jiffies,
 718                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 719                                 hlist_del(node);
 720                                 send_list_del(info);
 721                                 kref_put(&info->refcount, free_info);
 722                         }
 723                 }
 724         }
 725 }
 726
 727 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 728                                  struct vis_info *info)
 729 {
 730         struct neigh_node *router;
 731         struct hashtable_t *hash = bat_priv->orig_hash;
 732         struct hlist_node *node;
 733         struct hlist_head *head;
 734         struct orig_node *orig_node;
 735         struct vis_packet *packet;
 736         struct sk_buff *skb;
 737         struct hard_iface *hard_iface;
 738         uint8_t dstaddr[ETH_ALEN];
 739         uint32_t i;
 740
 741
 742         packet = (struct vis_packet *)info->skb_packet->data;
 743
 744         /* send to all routers in range. */
 745         for (i = 0; i < hash->size; i++) {
 746                 head = &hash->table[i];
 747
 748                 rcu_read_lock();
 749                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 750                         /* if it's a vis server and reachable, send it. */
 751                         if (!(orig_node->flags & VIS_SERVER))
 752                                 continue;
 753
 754                         router = orig_node_get_router(orig_node);
 755                         if (!router)
 756                                 continue;
 757
 758                         /* don't send it if we already received the packet from
 759                          * this node. */
 760                         if (recv_list_is_in(bat_priv, &info->recv_list,
 761                                             orig_node->orig)) {
 762                                 neigh_node_free_ref(router);
 763                                 continue;
 764                         }
 765
 766                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 767                         hard_iface = router->if_incoming;
 768                         memcpy(dstaddr, router->addr, ETH_ALEN);
 769
 770                         neigh_node_free_ref(router);
 771
 772                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 773                         if (skb)
 774                                 send_skb_packet(skb, hard_iface, dstaddr);
 775
 776                 }
 777                 rcu_read_unlock();
 778         }
 779 }
 780
 781 static void unicast_vis_packet(struct bat_priv *bat_priv,
 782                                struct vis_info *info)
 783 {
 784         struct orig_node *orig_node;
 785         struct neigh_node *router = NULL;
 786         struct sk_buff *skb;
 787         struct vis_packet *packet;
 788
 789         packet = (struct vis_packet *)info->skb_packet->data;
 790
 791         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 792         if (!orig_node)
 793                 goto out;
 794
 795         router = orig_node_get_router(orig_node);
 796         if (!router)
 797                 goto out;
 798
 799         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 800         if (skb)
 801                 send_skb_packet(skb, router->if_incoming, router->addr);
 802
 803 out:
 804         if (router)
 805                 neigh_node_free_ref(router);
 806         if (orig_node)
 807                 orig_node_free_ref(orig_node);
 808 }
 809
 810 /* only send one vis packet. called from send_vis_packets() */
 811 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 812 {
 813         struct hard_iface *primary_if;
 814         struct vis_packet *packet;
 815
 816         primary_if = primary_if_get_selected(bat_priv);
 817         if (!primary_if)
 818                 goto out;
 819
 820         packet = (struct vis_packet *)info->skb_packet->data;
 821         if (packet->ttl < 2) {
 822                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 823                 goto out;
 824         }
 825
 826         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 827         packet->ttl--;
 828
 829         if (is_broadcast_ether_addr(packet->target_orig))
 830                 broadcast_vis_packet(bat_priv, info);
 831         else
 832                 unicast_vis_packet(bat_priv, info);
 833         packet->ttl++; /* restore TTL */
 834
 835 out:
 836         if (primary_if)
 837                 hardif_free_ref(primary_if);
 838 }
 839
 840 /* called from timer; send (and maybe generate) vis packet. */
 841 static void send_vis_packets(struct work_struct *work)
 842 {
 843         struct delayed_work *delayed_work =
 844                 container_of(work, struct delayed_work, work);
 845         struct bat_priv *bat_priv =
 846                 container_of(delayed_work, struct bat_priv, vis_work);
 847         struct vis_info *info;
 848
 849         spin_lock_bh(&bat_priv->vis_hash_lock);
 850         purge_vis_packets(bat_priv);
 851
 852         if (generate_vis_packet(bat_priv) == 0) {
 853                 /* schedule if generation was successful */
 854                 send_list_add(bat_priv, bat_priv->my_vis_info);
 855         }
 856
 857         while (!list_empty(&bat_priv->vis_send_list)) {
 858                 info = list_first_entry(&bat_priv->vis_send_list,
 859                                         typeof(*info), send_list);
 860
 861                 kref_get(&info->refcount);
 862                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 863
 864                 send_vis_packet(bat_priv, info);
 865
 866                 spin_lock_bh(&bat_priv->vis_hash_lock);
 867                 send_list_del(info);
 868                 kref_put(&info->refcount, free_info);
 869         }
 870         spin_unlock_bh(&bat_priv->vis_hash_lock);
 871         start_vis_timer(bat_priv);
 872 }
 873
 874 /* init the vis server. this may only be called when if_list is already
 875  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 876 int vis_init(struct bat_priv *bat_priv)
 877 {
 878         struct vis_packet *packet;
 879         int hash_added;
 880
 881         if (bat_priv->vis_hash)
 882                 return 1;
 883
 884         spin_lock_bh(&bat_priv->vis_hash_lock);
 885
 886         bat_priv->vis_hash = hash_new(256);
 887         if (!bat_priv->vis_hash) {
 888                 pr_err("Can't initialize vis_hash\n");
 889                 goto err;
 890         }
 891
 892         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 893         if (!bat_priv->my_vis_info)
 894                 goto err;
 895
 896         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 897                                                           MAX_VIS_PACKET_SIZE +
 898                                                          sizeof(struct ethhdr));
 899         if (!bat_priv->my_vis_info->skb_packet)
 900                 goto free_info;
 901
 902         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 903         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 904                                               sizeof(*packet));
 905
 906         /* prefill the vis info */
 907         bat_priv->my_vis_info->first_seen = jiffies -
 908                                                 msecs_to_jiffies(VIS_INTERVAL);
 909         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 910         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 911         kref_init(&bat_priv->my_vis_info->refcount);
 912         bat_priv->my_vis_info->bat_priv = bat_priv;
 913         packet->version = COMPAT_VERSION;
 914         packet->packet_type = BAT_VIS;
 915         packet->ttl = TTL;
 916         packet->seqno = 0;
 917         packet->entries = 0;
 918
 919         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 920
 921         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 922                               bat_priv->my_vis_info,
 923                               &bat_priv->my_vis_info->hash_entry);
 924         if (hash_added != 0) {
 925                 pr_err("Can't add own vis packet into hash\n");
 926                 /* not in hash, need to remove it manually. */
 927                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 928                 goto err;
 929         }
 930
 931         spin_unlock_bh(&bat_priv->vis_hash_lock);
 932         start_vis_timer(bat_priv);
 933         return 1;
 934
 935 free_info:
 936         kfree(bat_priv->my_vis_info);
 937         bat_priv->my_vis_info = NULL;
 938 err:
 939         spin_unlock_bh(&bat_priv->vis_hash_lock);
 940         vis_quit(bat_priv);
 941         return 0;
 942 }
 943
 944 /* Decrease the reference count on a hash item info */
 945 static void free_info_ref(struct hlist_node *node, void *arg)
 946 {
 947         struct vis_info *info;
 948
 949         info = container_of(node, struct vis_info, hash_entry);
 950         send_list_del(info);
 951         kref_put(&info->refcount, free_info);
 952 }
 953
 954 /* shutdown vis-server */
 955 void vis_quit(struct bat_priv *bat_priv)
 956 {
 957         if (!bat_priv->vis_hash)
 958                 return;
 959
 960         cancel_delayed_work_sync(&bat_priv->vis_work);
 961
 962         spin_lock_bh(&bat_priv->vis_hash_lock);
 963         /* properly remove, kill timers ... */
 964         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 965         bat_priv->vis_hash = NULL;
 966         bat_priv->my_vis_info = NULL;
 967         spin_unlock_bh(&bat_priv->vis_hash_lock);
 968 }
 969
 970 /* schedule packets for (re)transmission */
 971 static void start_vis_timer(struct bat_priv *bat_priv)
 972 {
 973         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 974         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 975                            msecs_to_jiffies(VIS_INTERVAL));
 976 }