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