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 /* Returns the smallest signed integer in two's complement with the sizeof x */
  34 #define smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))
  35
  36 /* Checks if a sequence number x is a predecessor/successor of y.
  37  * they handle overflows/underflows and can correctly check for a
  38  * predecessor/successor unless the variable sequence number has grown by
  39  * more then 2**(bitwidth(x)-1)-1.
  40  * This means that for a uint8_t with the maximum value 255, it would think:
  41  *  - when adding nothing - it is neither a predecessor nor a successor
  42  *  - before adding more than 127 to the starting value - it is a predecessor,
  43  *  - when adding 128 - it is neither a predecessor nor a successor,
  44  *  - after adding more than 127 to the starting value - it is a successor */
  45 #define seq_before(x, y) ({typeof(x) _dummy = (x - y); \
  46                         _dummy > smallest_signed_int(_dummy); })
  47 #define seq_after(x, y) seq_before(y, x)
  48
  49 static void start_vis_timer(struct bat_priv *bat_priv);
  50
  51 /* free the info */
  52 static void free_info(struct kref *ref)
  53 {
  54         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  55         struct bat_priv *bat_priv = info->bat_priv;
  56         struct recvlist_node *entry, *tmp;
  57
  58         list_del_init(&info->send_list);
  59         spin_lock_bh(&bat_priv->vis_list_lock);
  60         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  61                 list_del(&entry->list);
  62                 kfree(entry);
  63         }
  64
  65         spin_unlock_bh(&bat_priv->vis_list_lock);
  66         kfree_skb(info->skb_packet);
  67         kfree(info);
  68 }
  69
  70 /* Compare two vis packets, used by the hashing algorithm */
  71 static int vis_info_cmp(const struct hlist_node *node, const void *data2)
  72 {
  73         const struct vis_info *d1, *d2;
  74         const struct vis_packet *p1, *p2;
  75
  76         d1 = container_of(node, struct vis_info, hash_entry);
  77         d2 = data2;
  78         p1 = (struct vis_packet *)d1->skb_packet->data;
  79         p2 = (struct vis_packet *)d2->skb_packet->data;
  80         return compare_eth(p1->vis_orig, p2->vis_orig);
  81 }
  82
  83 /* hash function to choose an entry in a hash table of given size */
  84 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  85 static int vis_info_choose(const void *data, int size)
  86 {
  87         const struct vis_info *vis_info = data;
  88         const struct vis_packet *packet;
  89         const unsigned char *key;
  90         uint32_t hash = 0;
  91         size_t i;
  92
  93         packet = (struct vis_packet *)vis_info->skb_packet->data;
  94         key = packet->vis_orig;
  95         for (i = 0; i < ETH_ALEN; i++) {
  96                 hash += key[i];
  97                 hash += (hash << 10);
  98                 hash ^= (hash >> 6);
  99         }
 100
 101         hash += (hash << 3);
 102         hash ^= (hash >> 11);
 103         hash += (hash << 15);
 104
 105         return hash % size;
 106 }
 107
 108 static struct vis_info *vis_hash_find(struct bat_priv *bat_priv,
 109                                       const void *data)
 110 {
 111         struct hashtable_t *hash = bat_priv->vis_hash;
 112         struct hlist_head *head;
 113         struct hlist_node *node;
 114         struct vis_info *vis_info, *vis_info_tmp = NULL;
 115         int index;
 116
 117         if (!hash)
 118                 return NULL;
 119
 120         index = vis_info_choose(data, hash->size);
 121         head = &hash->table[index];
 122
 123         rcu_read_lock();
 124         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 125                 if (!vis_info_cmp(node, data))
 126                         continue;
 127
 128                 vis_info_tmp = vis_info;
 129                 break;
 130         }
 131         rcu_read_unlock();
 132
 133         return vis_info_tmp;
 134 }
 135
 136 /* insert interface to the list of interfaces of one originator, if it
 137  * does not already exist in the list */
 138 static void vis_data_insert_interface(const uint8_t *interface,
 139                                       struct hlist_head *if_list,
 140                                       bool primary)
 141 {
 142         struct if_list_entry *entry;
 143         struct hlist_node *pos;
 144
 145         hlist_for_each_entry(entry, pos, if_list, list) {
 146                 if (compare_eth(entry->addr, interface))
 147                         return;
 148         }
 149
 150         /* its a new address, add it to the list */
 151         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 152         if (!entry)
 153                 return;
 154         memcpy(entry->addr, interface, ETH_ALEN);
 155         entry->primary = primary;
 156         hlist_add_head(&entry->list, if_list);
 157 }
 158
 159 static ssize_t vis_data_read_prim_sec(char *buff,
 160                                       const struct hlist_head *if_list)
 161 {
 162         struct if_list_entry *entry;
 163         struct hlist_node *pos;
 164         size_t len = 0;
 165
 166         hlist_for_each_entry(entry, pos, if_list, list) {
 167                 if (entry->primary)
 168                         len += sprintf(buff + len, "PRIMARY, ");
 169                 else
 170                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 171         }
 172
 173         return len;
 174 }
 175
 176 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 177 {
 178         struct if_list_entry *entry;
 179         struct hlist_node *pos;
 180         size_t count = 0;
 181
 182         hlist_for_each_entry(entry, pos, if_list, list) {
 183                 if (entry->primary)
 184                         count += 9;
 185                 else
 186                         count += 23;
 187         }
 188
 189         return count;
 190 }
 191
 192 /* read an entry  */
 193 static ssize_t vis_data_read_entry(char *buff,
 194                                    const struct vis_info_entry *entry,
 195                                    const uint8_t *src, bool primary)
 196 {
 197         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 198         if (primary && entry->quality == 0)
 199                 return sprintf(buff, "TT %pM, ", entry->dest);
 200         else if (compare_eth(entry->src, src))
 201                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 202                                entry->quality);
 203
 204         return 0;
 205 }
 206
 207 int vis_seq_print_text(struct seq_file *seq, void *offset)
 208 {
 209         struct hard_iface *primary_if;
 210         struct hlist_node *node;
 211         struct hlist_head *head;
 212         struct vis_info *info;
 213         struct vis_packet *packet;
 214         struct vis_info_entry *entries;
 215         struct net_device *net_dev = (struct net_device *)seq->private;
 216         struct bat_priv *bat_priv = netdev_priv(net_dev);
 217         struct hashtable_t *hash = bat_priv->vis_hash;
 218         HLIST_HEAD(vis_if_list);
 219         struct if_list_entry *entry;
 220         struct hlist_node *pos, *n;
 221         int i, j, ret = 0;
 222         int vis_server = atomic_read(&bat_priv->vis_mode);
 223         size_t buff_pos, buf_size;
 224         char *buff;
 225         int compare;
 226
 227         primary_if = primary_if_get_selected(bat_priv);
 228         if (!primary_if)
 229                 goto out;
 230
 231         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 232                 goto out;
 233
 234         buf_size = 1;
 235         /* Estimate length */
 236         spin_lock_bh(&bat_priv->vis_hash_lock);
 237         for (i = 0; i < hash->size; i++) {
 238                 head = &hash->table[i];
 239
 240                 rcu_read_lock();
 241                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 242                         packet = (struct vis_packet *)info->skb_packet->data;
 243                         entries = (struct vis_info_entry *)
 244                                 ((char *)packet + sizeof(*packet));
 245
 246                         for (j = 0; j < packet->entries; j++) {
 247                                 if (entries[j].quality == 0)
 248                                         continue;
 249                                 compare =
 250                                  compare_eth(entries[j].src, packet->vis_orig);
 251                                 vis_data_insert_interface(entries[j].src,
 252                                                           &vis_if_list,
 253                                                           compare);
 254                         }
 255
 256                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 257                                 buf_size += 18 + 26 * packet->entries;
 258
 259                                 /* add primary/secondary records */
 260                                 if (compare_eth(entry->addr, packet->vis_orig))
 261                                         buf_size +=
 262                                           vis_data_count_prim_sec(&vis_if_list);
 263
 264                                 buf_size += 1;
 265                         }
 266
 267                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 268                                                   list) {
 269                                 hlist_del(&entry->list);
 270                                 kfree(entry);
 271                         }
 272                 }
 273                 rcu_read_unlock();
 274         }
 275
 276         buff = kmalloc(buf_size, GFP_ATOMIC);
 277         if (!buff) {
 278                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 279                 ret = -ENOMEM;
 280                 goto out;
 281         }
 282         buff[0] = '\0';
 283         buff_pos = 0;
 284
 285         for (i = 0; i < hash->size; i++) {
 286                 head = &hash->table[i];
 287
 288                 rcu_read_lock();
 289                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 290                         packet = (struct vis_packet *)info->skb_packet->data;
 291                         entries = (struct vis_info_entry *)
 292                                 ((char *)packet + sizeof(*packet));
 293
 294                         for (j = 0; j < packet->entries; j++) {
 295                                 if (entries[j].quality == 0)
 296                                         continue;
 297                                 compare =
 298                                  compare_eth(entries[j].src, packet->vis_orig);
 299                                 vis_data_insert_interface(entries[j].src,
 300                                                           &vis_if_list,
 301                                                           compare);
 302                         }
 303
 304                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 305                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 306                                                 entry->addr);
 307
 308                                 for (j = 0; j < packet->entries; j++)
 309                                         buff_pos += vis_data_read_entry(
 310                                                         buff + buff_pos,
 311                                                         &entries[j],
 312                                                         entry->addr,
 313                                                         entry->primary);
 314
 315                                 /* add primary/secondary records */
 316                                 if (compare_eth(entry->addr, packet->vis_orig))
 317                                         buff_pos +=
 318                                          vis_data_read_prim_sec(buff + buff_pos,
 319                                                                 &vis_if_list);
 320
 321                                 buff_pos += sprintf(buff + buff_pos, "\n");
 322                         }
 323
 324                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 325                                                   list) {
 326                                 hlist_del(&entry->list);
 327                                 kfree(entry);
 328                         }
 329                 }
 330                 rcu_read_unlock();
 331         }
 332
 333         spin_unlock_bh(&bat_priv->vis_hash_lock);
 334
 335         seq_printf(seq, "%s", buff);
 336         kfree(buff);
 337
 338 out:
 339         if (primary_if)
 340                 hardif_free_ref(primary_if);
 341         return ret;
 342 }
 343
 344 /* add the info packet to the send list, if it was not
 345  * already linked in. */
 346 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 347 {
 348         if (list_empty(&info->send_list)) {
 349                 kref_get(&info->refcount);
 350                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 351         }
 352 }
 353
 354 /* delete the info packet from the send list, if it was
 355  * linked in. */
 356 static void send_list_del(struct vis_info *info)
 357 {
 358         if (!list_empty(&info->send_list)) {
 359                 list_del_init(&info->send_list);
 360                 kref_put(&info->refcount, free_info);
 361         }
 362 }
 363
 364 /* tries to add one entry to the receive list. */
 365 static void recv_list_add(struct bat_priv *bat_priv,
 366                           struct list_head *recv_list, const char *mac)
 367 {
 368         struct recvlist_node *entry;
 369
 370         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 371         if (!entry)
 372                 return;
 373
 374         memcpy(entry->mac, mac, ETH_ALEN);
 375         spin_lock_bh(&bat_priv->vis_list_lock);
 376         list_add_tail(&entry->list, recv_list);
 377         spin_unlock_bh(&bat_priv->vis_list_lock);
 378 }
 379
 380 /* returns 1 if this mac is in the recv_list */
 381 static int recv_list_is_in(struct bat_priv *bat_priv,
 382                            const struct list_head *recv_list, const char *mac)
 383 {
 384         const struct recvlist_node *entry;
 385
 386         spin_lock_bh(&bat_priv->vis_list_lock);
 387         list_for_each_entry(entry, recv_list, list) {
 388                 if (compare_eth(entry->mac, mac)) {
 389                         spin_unlock_bh(&bat_priv->vis_list_lock);
 390                         return 1;
 391                 }
 392         }
 393         spin_unlock_bh(&bat_priv->vis_list_lock);
 394         return 0;
 395 }
 396
 397 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 398  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 399  * is newer than old entries in the hash. */
 400 static struct vis_info *add_packet(struct bat_priv *bat_priv,
 401                                    struct vis_packet *vis_packet,
 402                                    int vis_info_len, int *is_new,
 403                                    int make_broadcast)
 404 {
 405         struct vis_info *info, *old_info;
 406         struct vis_packet *search_packet, *old_packet;
 407         struct vis_info search_elem;
 408         struct vis_packet *packet;
 409         int hash_added;
 410
 411         *is_new = 0;
 412         /* sanity check */
 413         if (!bat_priv->vis_hash)
 414                 return NULL;
 415
 416         /* see if the packet is already in vis_hash */
 417         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 418         if (!search_elem.skb_packet)
 419                 return NULL;
 420         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 421                                                      sizeof(*search_packet));
 422
 423         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 424         old_info = vis_hash_find(bat_priv, &search_elem);
 425         kfree_skb(search_elem.skb_packet);
 426
 427         if (old_info) {
 428                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 429                 if (!seq_after(ntohl(vis_packet->seqno),
 430                                ntohl(old_packet->seqno))) {
 431                         if (old_packet->seqno == vis_packet->seqno) {
 432                                 recv_list_add(bat_priv, &old_info->recv_list,
 433                                               vis_packet->sender_orig);
 434                                 return old_info;
 435                         } else {
 436                                 /* newer packet is already in hash. */
 437                                 return NULL;
 438                         }
 439                 }
 440                 /* remove old entry */
 441                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 442                             old_info);
 443                 send_list_del(old_info);
 444                 kref_put(&old_info->refcount, free_info);
 445         }
 446
 447         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 448         if (!info)
 449                 return NULL;
 450
 451         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 452                                          sizeof(struct ethhdr));
 453         if (!info->skb_packet) {
 454                 kfree(info);
 455                 return NULL;
 456         }
 457         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 458         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 459                                               + vis_info_len);
 460
 461         kref_init(&info->refcount);
 462         INIT_LIST_HEAD(&info->send_list);
 463         INIT_LIST_HEAD(&info->recv_list);
 464         info->first_seen = jiffies;
 465         info->bat_priv = bat_priv;
 466         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 467
 468         /* initialize and add new packet. */
 469         *is_new = 1;
 470
 471         /* Make it a broadcast packet, if required */
 472         if (make_broadcast)
 473                 memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 474
 475         /* repair if entries is longer than packet. */
 476         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 477                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 478
 479         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 480
 481         /* try to add it */
 482         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 483                               info, &info->hash_entry);
 484         if (hash_added < 0) {
 485                 /* did not work (for some reason) */
 486                 kref_put(&info->refcount, free_info);
 487                 info = NULL;
 488         }
 489
 490         return info;
 491 }
 492
 493 /* handle the server sync packet, forward if needed. */
 494 void receive_server_sync_packet(struct bat_priv *bat_priv,
 495                                 struct vis_packet *vis_packet,
 496                                 int vis_info_len)
 497 {
 498         struct vis_info *info;
 499         int is_new, make_broadcast;
 500         int vis_server = atomic_read(&bat_priv->vis_mode);
 501
 502         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 503
 504         spin_lock_bh(&bat_priv->vis_hash_lock);
 505         info = add_packet(bat_priv, vis_packet, vis_info_len,
 506                           &is_new, make_broadcast);
 507         if (!info)
 508                 goto end;
 509
 510         /* only if we are server ourselves and packet is newer than the one in
 511          * hash.*/
 512         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 513                 send_list_add(bat_priv, info);
 514 end:
 515         spin_unlock_bh(&bat_priv->vis_hash_lock);
 516 }
 517
 518 /* handle an incoming client update packet and schedule forward if needed. */
 519 void receive_client_update_packet(struct bat_priv *bat_priv,
 520                                   struct vis_packet *vis_packet,
 521                                   int vis_info_len)
 522 {
 523         struct vis_info *info;
 524         struct vis_packet *packet;
 525         int is_new;
 526         int vis_server = atomic_read(&bat_priv->vis_mode);
 527         int are_target = 0;
 528
 529         /* clients shall not broadcast. */
 530         if (is_broadcast_ether_addr(vis_packet->target_orig))
 531                 return;
 532
 533         /* Are we the target for this VIS packet? */
 534         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 535             is_my_mac(vis_packet->target_orig))
 536                 are_target = 1;
 537
 538         spin_lock_bh(&bat_priv->vis_hash_lock);
 539         info = add_packet(bat_priv, vis_packet, vis_info_len,
 540                           &is_new, are_target);
 541
 542         if (!info)
 543                 goto end;
 544         /* note that outdated packets will be dropped at this point. */
 545
 546         packet = (struct vis_packet *)info->skb_packet->data;
 547
 548         /* send only if we're the target server or ... */
 549         if (are_target && is_new) {
 550                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 551                 send_list_add(bat_priv, info);
 552
 553                 /* ... we're not the recipient (and thus need to forward). */
 554         } else if (!is_my_mac(packet->target_orig)) {
 555                 send_list_add(bat_priv, info);
 556         }
 557
 558 end:
 559         spin_unlock_bh(&bat_priv->vis_hash_lock);
 560 }
 561
 562 /* Walk the originators and find the VIS server with the best tq. Set the packet
 563  * address to its address and return the best_tq.
 564  *
 565  * Must be called with the originator hash locked */
 566 static int find_best_vis_server(struct bat_priv *bat_priv,
 567                                 struct vis_info *info)
 568 {
 569         struct hashtable_t *hash = bat_priv->orig_hash;
 570         struct neigh_node *router;
 571         struct hlist_node *node;
 572         struct hlist_head *head;
 573         struct orig_node *orig_node;
 574         struct vis_packet *packet;
 575         int best_tq = -1, i;
 576
 577         packet = (struct vis_packet *)info->skb_packet->data;
 578
 579         for (i = 0; i < hash->size; i++) {
 580                 head = &hash->table[i];
 581
 582                 rcu_read_lock();
 583                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 584                         router = orig_node_get_router(orig_node);
 585                         if (!router)
 586                                 continue;
 587
 588                         if ((orig_node->flags & VIS_SERVER) &&
 589                             (router->tq_avg > best_tq)) {
 590                                 best_tq = router->tq_avg;
 591                                 memcpy(packet->target_orig, orig_node->orig,
 592                                        ETH_ALEN);
 593                         }
 594                         neigh_node_free_ref(router);
 595                 }
 596                 rcu_read_unlock();
 597         }
 598
 599         return best_tq;
 600 }
 601
 602 /* Return true if the vis packet is full. */
 603 static bool vis_packet_full(const struct vis_info *info)
 604 {
 605         const struct vis_packet *packet;
 606         packet = (struct vis_packet *)info->skb_packet->data;
 607
 608         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 609                 < packet->entries + 1)
 610                 return true;
 611         return false;
 612 }
 613
 614 /* generates a packet of own vis data,
 615  * returns 0 on success, -1 if no packet could be generated */
 616 static int generate_vis_packet(struct bat_priv *bat_priv)
 617 {
 618         struct hashtable_t *hash = bat_priv->orig_hash;
 619         struct hlist_node *node;
 620         struct hlist_head *head;
 621         struct orig_node *orig_node;
 622         struct neigh_node *router;
 623         struct vis_info *info = bat_priv->my_vis_info;
 624         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 625         struct vis_info_entry *entry;
 626         struct tt_local_entry *tt_local_entry;
 627         int best_tq = -1, i;
 628
 629         info->first_seen = jiffies;
 630         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 631
 632         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 633         packet->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 -1;
 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 = 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                         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         spin_lock_bh(&bat_priv->tt_lhash_lock);
 685         for (i = 0; i < hash->size; i++) {
 686                 head = &hash->table[i];
 687
 688                 hlist_for_each_entry(tt_local_entry, node, head, hash_entry) {
 689                         entry = (struct vis_info_entry *)
 690                                         skb_put(info->skb_packet,
 691                                                 sizeof(*entry));
 692                         memset(entry->src, 0, ETH_ALEN);
 693                         memcpy(entry->dest, tt_local_entry->addr, ETH_ALEN);
 694                         entry->quality = 0; /* 0 means TT */
 695                         packet->entries++;
 696
 697                         if (vis_packet_full(info)) {
 698                                 spin_unlock_bh(&bat_priv->tt_lhash_lock);
 699                                 return 0;
 700                         }
 701                 }
 702         }
 703
 704         spin_unlock_bh(&bat_priv->tt_lhash_lock);
 705         return 0;
 706
 707 unlock:
 708         rcu_read_unlock();
 709         return 0;
 710 }
 711
 712 /* free old vis packets. Must be called with this vis_hash_lock
 713  * held */
 714 static void purge_vis_packets(struct bat_priv *bat_priv)
 715 {
 716         int 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 (time_after(jiffies,
 732                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 733                                 hlist_del(node);
 734                                 send_list_del(info);
 735                                 kref_put(&info->refcount, free_info);
 736                         }
 737                 }
 738         }
 739 }
 740
 741 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 742                                  struct vis_info *info)
 743 {
 744         struct neigh_node *router;
 745         struct hashtable_t *hash = bat_priv->orig_hash;
 746         struct hlist_node *node;
 747         struct hlist_head *head;
 748         struct orig_node *orig_node;
 749         struct vis_packet *packet;
 750         struct sk_buff *skb;
 751         struct hard_iface *hard_iface;
 752         uint8_t dstaddr[ETH_ALEN];
 753         int i;
 754
 755
 756         packet = (struct vis_packet *)info->skb_packet->data;
 757
 758         /* send to all routers in range. */
 759         for (i = 0; i < hash->size; i++) {
 760                 head = &hash->table[i];
 761
 762                 rcu_read_lock();
 763                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 764                         /* if it's a vis server and reachable, send it. */
 765                         if (!(orig_node->flags & VIS_SERVER))
 766                                 continue;
 767
 768                         router = orig_node_get_router(orig_node);
 769                         if (!router)
 770                                 continue;
 771
 772                         /* don't send it if we already received the packet from
 773                          * this node. */
 774                         if (recv_list_is_in(bat_priv, &info->recv_list,
 775                                             orig_node->orig)) {
 776                                 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                         neigh_node_free_ref(router);
 785
 786                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 787                         if (skb)
 788                                 send_skb_packet(skb, hard_iface, dstaddr);
 789
 790                 }
 791                 rcu_read_unlock();
 792         }
 793 }
 794
 795 static void unicast_vis_packet(struct bat_priv *bat_priv,
 796                                struct vis_info *info)
 797 {
 798         struct orig_node *orig_node;
 799         struct neigh_node *router = NULL;
 800         struct sk_buff *skb;
 801         struct vis_packet *packet;
 802
 803         packet = (struct vis_packet *)info->skb_packet->data;
 804
 805         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 806         if (!orig_node)
 807                 goto out;
 808
 809         router = orig_node_get_router(orig_node);
 810         if (!router)
 811                 goto out;
 812
 813         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 814         if (skb)
 815                 send_skb_packet(skb, router->if_incoming, router->addr);
 816
 817 out:
 818         if (router)
 819                 neigh_node_free_ref(router);
 820         if (orig_node)
 821                 orig_node_free_ref(orig_node);
 822 }
 823
 824 /* only send one vis packet. called from send_vis_packets() */
 825 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 826 {
 827         struct hard_iface *primary_if;
 828         struct vis_packet *packet;
 829
 830         primary_if = primary_if_get_selected(bat_priv);
 831         if (!primary_if)
 832                 goto out;
 833
 834         packet = (struct vis_packet *)info->skb_packet->data;
 835         if (packet->ttl < 2) {
 836                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 837                 goto out;
 838         }
 839
 840         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 841         packet->ttl--;
 842
 843         if (is_broadcast_ether_addr(packet->target_orig))
 844                 broadcast_vis_packet(bat_priv, info);
 845         else
 846                 unicast_vis_packet(bat_priv, info);
 847         packet->ttl++; /* restore TTL */
 848
 849 out:
 850         if (primary_if)
 851                 hardif_free_ref(primary_if);
 852 }
 853
 854 /* called from timer; send (and maybe generate) vis packet. */
 855 static void send_vis_packets(struct work_struct *work)
 856 {
 857         struct delayed_work *delayed_work =
 858                 container_of(work, struct delayed_work, work);
 859         struct bat_priv *bat_priv =
 860                 container_of(delayed_work, struct bat_priv, vis_work);
 861         struct vis_info *info;
 862
 863         spin_lock_bh(&bat_priv->vis_hash_lock);
 864         purge_vis_packets(bat_priv);
 865
 866         if (generate_vis_packet(bat_priv) == 0) {
 867                 /* schedule if generation was successful */
 868                 send_list_add(bat_priv, bat_priv->my_vis_info);
 869         }
 870
 871         while (!list_empty(&bat_priv->vis_send_list)) {
 872                 info = list_first_entry(&bat_priv->vis_send_list,
 873                                         typeof(*info), send_list);
 874
 875                 kref_get(&info->refcount);
 876                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 877
 878                 send_vis_packet(bat_priv, info);
 879
 880                 spin_lock_bh(&bat_priv->vis_hash_lock);
 881                 send_list_del(info);
 882                 kref_put(&info->refcount, free_info);
 883         }
 884         spin_unlock_bh(&bat_priv->vis_hash_lock);
 885         start_vis_timer(bat_priv);
 886 }
 887
 888 /* init the vis server. this may only be called when if_list is already
 889  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 890 int vis_init(struct bat_priv *bat_priv)
 891 {
 892         struct vis_packet *packet;
 893         int hash_added;
 894
 895         if (bat_priv->vis_hash)
 896                 return 1;
 897
 898         spin_lock_bh(&bat_priv->vis_hash_lock);
 899
 900         bat_priv->vis_hash = hash_new(256);
 901         if (!bat_priv->vis_hash) {
 902                 pr_err("Can't initialize vis_hash\n");
 903                 goto err;
 904         }
 905
 906         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 907         if (!bat_priv->my_vis_info) {
 908                 pr_err("Can't initialize vis packet\n");
 909                 goto err;
 910         }
 911
 912         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 913                                                           MAX_VIS_PACKET_SIZE +
 914                                                          sizeof(struct ethhdr));
 915         if (!bat_priv->my_vis_info->skb_packet)
 916                 goto free_info;
 917
 918         skb_reserve(bat_priv->my_vis_info->skb_packet, sizeof(struct ethhdr));
 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->version = COMPAT_VERSION;
 930         packet->packet_type = BAT_VIS;
 931         packet->ttl = TTL;
 932         packet->seqno = 0;
 933         packet->entries = 0;
 934
 935         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 936
 937         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 938                               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 1;
 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         vis_quit(bat_priv);
 957         return 0;
 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 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         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(bat_event_workqueue, &bat_priv->vis_work,
 991                            msecs_to_jiffies(VIS_INTERVAL));
 992 }