net/batman-adv/vis.c

   1 /* Copyright (C) 2008-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "send.h"
  22 #include "translation-table.h"
  23 #include "vis.h"
  24 #include "soft-interface.h"
  25 #include "hard-interface.h"
  26 #include "hash.h"
  27 #include "originator.h"
  28
  29 #define MAX_VIS_PACKET_SIZE 1000
  30
  31 static void batadv_start_vis_timer(struct bat_priv *bat_priv);
  32
  33 /* free the info */
  34 static void batadv_free_info(struct kref *ref)
  35 {
  36         struct vis_info *info = container_of(ref, struct vis_info, refcount);
  37         struct bat_priv *bat_priv = info->bat_priv;
  38         struct recvlist_node *entry, *tmp;
  39
  40         list_del_init(&info->send_list);
  41         spin_lock_bh(&bat_priv->vis_list_lock);
  42         list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
  43                 list_del(&entry->list);
  44                 kfree(entry);
  45         }
  46
  47         spin_unlock_bh(&bat_priv->vis_list_lock);
  48         kfree_skb(info->skb_packet);
  49         kfree(info);
  50 }
  51
  52 /* Compare two vis packets, used by the hashing algorithm */
  53 static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
  54 {
  55         const struct vis_info *d1, *d2;
  56         const struct vis_packet *p1, *p2;
  57
  58         d1 = container_of(node, struct vis_info, hash_entry);
  59         d2 = data2;
  60         p1 = (struct vis_packet *)d1->skb_packet->data;
  61         p2 = (struct vis_packet *)d2->skb_packet->data;
  62         return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
  63 }
  64
  65 /* hash function to choose an entry in a hash table of given size
  66  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  67  */
  68 static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
  69 {
  70         const struct vis_info *vis_info = data;
  71         const struct vis_packet *packet;
  72         const unsigned char *key;
  73         uint32_t hash = 0;
  74         size_t i;
  75
  76         packet = (struct vis_packet *)vis_info->skb_packet->data;
  77         key = packet->vis_orig;
  78         for (i = 0; i < ETH_ALEN; i++) {
  79                 hash += key[i];
  80                 hash += (hash << 10);
  81                 hash ^= (hash >> 6);
  82         }
  83
  84         hash += (hash << 3);
  85         hash ^= (hash >> 11);
  86         hash += (hash << 15);
  87
  88         return hash % size;
  89 }
  90
  91 static struct vis_info *batadv_vis_hash_find(struct bat_priv *bat_priv,
  92                                              const void *data)
  93 {
  94         struct hashtable_t *hash = bat_priv->vis_hash;
  95         struct hlist_head *head;
  96         struct hlist_node *node;
  97         struct vis_info *vis_info, *vis_info_tmp = NULL;
  98         uint32_t index;
  99
 100         if (!hash)
 101                 return NULL;
 102
 103         index = batadv_vis_info_choose(data, hash->size);
 104         head = &hash->table[index];
 105
 106         rcu_read_lock();
 107         hlist_for_each_entry_rcu(vis_info, node, head, hash_entry) {
 108                 if (!batadv_vis_info_cmp(node, data))
 109                         continue;
 110
 111                 vis_info_tmp = vis_info;
 112                 break;
 113         }
 114         rcu_read_unlock();
 115
 116         return vis_info_tmp;
 117 }
 118
 119 /* insert interface to the list of interfaces of one originator, if it
 120  * does not already exist in the list
 121  */
 122 static void batadv_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 (batadv_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 batadv_vis_prim_sec(char *buff, const struct hlist_head *if_list)
 144 {
 145         struct if_list_entry *entry;
 146         struct hlist_node *pos;
 147         size_t len = 0;
 148
 149         hlist_for_each_entry(entry, pos, if_list, list) {
 150                 if (entry->primary)
 151                         len += sprintf(buff + len, "PRIMARY, ");
 152                 else
 153                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 154         }
 155
 156         return len;
 157 }
 158
 159 static size_t batadv_vis_cnt_prim_sec(struct hlist_head *if_list)
 160 {
 161         struct if_list_entry *entry;
 162         struct hlist_node *pos;
 163         size_t count = 0;
 164
 165         hlist_for_each_entry(entry, pos, if_list, list) {
 166                 if (entry->primary)
 167                         count += 9;
 168                 else
 169                         count += 23;
 170         }
 171
 172         return count;
 173 }
 174
 175 /* read an entry  */
 176 static ssize_t batadv_vis_data_read_entry(char *buff,
 177                                           const struct vis_info_entry *entry,
 178                                           const uint8_t *src, bool primary)
 179 {
 180         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 181         if (primary && entry->quality == 0)
 182                 return sprintf(buff, "TT %pM, ", entry->dest);
 183         else if (batadv_compare_eth(entry->src, src))
 184                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 185                                entry->quality);
 186
 187         return 0;
 188 }
 189
 190 int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
 191 {
 192         struct hard_iface *primary_if;
 193         struct hlist_node *node;
 194         struct hlist_head *head;
 195         struct vis_info *info;
 196         struct vis_packet *packet;
 197         struct vis_info_entry *entries;
 198         struct net_device *net_dev = (struct net_device *)seq->private;
 199         struct bat_priv *bat_priv = netdev_priv(net_dev);
 200         struct hashtable_t *hash = bat_priv->vis_hash;
 201         HLIST_HEAD(vis_if_list);
 202         struct if_list_entry *entry;
 203         struct hlist_node *pos, *n;
 204         uint32_t i;
 205         int j, ret = 0;
 206         int vis_server = atomic_read(&bat_priv->vis_mode);
 207         size_t buff_pos, buf_size;
 208         char *buff;
 209
 210         primary_if = batadv_primary_if_get_selected(bat_priv);
 211         if (!primary_if)
 212                 goto out;
 213
 214         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 215                 goto out;
 216
 217         buf_size = 1;
 218         /* Estimate length */
 219         spin_lock_bh(&bat_priv->vis_hash_lock);
 220         for (i = 0; i < hash->size; i++) {
 221                 head = &hash->table[i];
 222
 223                 rcu_read_lock();
 224                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 225                         packet = (struct vis_packet *)info->skb_packet->data;
 226                         entries = (struct vis_info_entry *)
 227                                 ((char *)packet + sizeof(*packet));
 228
 229                         batadv_vis_data_insert_interface(packet->vis_orig,
 230                                                          &vis_if_list, true);
 231
 232                         for (j = 0; j < packet->entries; j++) {
 233                                 if (entries[j].quality == 0)
 234                                         continue;
 235                                 if (batadv_compare_eth(entries[j].src,
 236                                                        packet->vis_orig))
 237                                         continue;
 238                                 batadv_vis_data_insert_interface(entries[j].src,
 239                                                                  &vis_if_list,
 240                                                                  false);
 241                         }
 242
 243                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 244                                 buf_size += 18 + 26 * packet->entries;
 245
 246                                 /* add primary/secondary records */
 247                                 if (batadv_compare_eth(entry->addr,
 248                                                        packet->vis_orig))
 249                                         buf_size +=
 250                                           batadv_vis_cnt_prim_sec(&vis_if_list);
 251
 252                                 buf_size += 1;
 253                         }
 254
 255                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 256                                                   list) {
 257                                 hlist_del(&entry->list);
 258                                 kfree(entry);
 259                         }
 260                 }
 261                 rcu_read_unlock();
 262         }
 263
 264         buff = kmalloc(buf_size, GFP_ATOMIC);
 265         if (!buff) {
 266                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 267                 ret = -ENOMEM;
 268                 goto out;
 269         }
 270         buff[0] = '\0';
 271         buff_pos = 0;
 272
 273         for (i = 0; i < hash->size; i++) {
 274                 head = &hash->table[i];
 275
 276                 rcu_read_lock();
 277                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 278                         packet = (struct vis_packet *)info->skb_packet->data;
 279                         entries = (struct vis_info_entry *)
 280                                 ((char *)packet + sizeof(*packet));
 281
 282                         batadv_vis_data_insert_interface(packet->vis_orig,
 283                                                          &vis_if_list, true);
 284
 285                         for (j = 0; j < packet->entries; j++) {
 286                                 if (entries[j].quality == 0)
 287                                         continue;
 288                                 if (batadv_compare_eth(entries[j].src,
 289                                                        packet->vis_orig))
 290                                         continue;
 291                                 batadv_vis_data_insert_interface(entries[j].src,
 292                                                                  &vis_if_list,
 293                                                                  false);
 294                         }
 295
 296                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 297                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 298                                                 entry->addr);
 299
 300                                 for (j = 0; j < packet->entries; j++)
 301                                         buff_pos += batadv_vis_data_read_entry(
 302                                                         buff + buff_pos,
 303                                                         &entries[j],
 304                                                         entry->addr,
 305                                                         entry->primary);
 306
 307                                 /* add primary/secondary records */
 308                                 if (batadv_compare_eth(entry->addr,
 309                                                        packet->vis_orig))
 310                                         buff_pos +=
 311                                          batadv_vis_prim_sec(buff + buff_pos,
 312                                                              &vis_if_list);
 313
 314                                 buff_pos += sprintf(buff + buff_pos, "\n");
 315                         }
 316
 317                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 318                                                   list) {
 319                                 hlist_del(&entry->list);
 320                                 kfree(entry);
 321                         }
 322                 }
 323                 rcu_read_unlock();
 324         }
 325
 326         spin_unlock_bh(&bat_priv->vis_hash_lock);
 327
 328         seq_printf(seq, "%s", buff);
 329         kfree(buff);
 330
 331 out:
 332         if (primary_if)
 333                 batadv_hardif_free_ref(primary_if);
 334         return ret;
 335 }
 336
 337 /* add the info packet to the send list, if it was not
 338  * already linked in.
 339  */
 340 static void batadv_send_list_add(struct bat_priv *bat_priv,
 341                                  struct vis_info *info)
 342 {
 343         if (list_empty(&info->send_list)) {
 344                 kref_get(&info->refcount);
 345                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 346         }
 347 }
 348
 349 /* delete the info packet from the send list, if it was
 350  * linked in.
 351  */
 352 static void batadv_send_list_del(struct vis_info *info)
 353 {
 354         if (!list_empty(&info->send_list)) {
 355                 list_del_init(&info->send_list);
 356                 kref_put(&info->refcount, batadv_free_info);
 357         }
 358 }
 359
 360 /* tries to add one entry to the receive list. */
 361 static void batadv_recv_list_add(struct bat_priv *bat_priv,
 362                                  struct list_head *recv_list, const char *mac)
 363 {
 364         struct recvlist_node *entry;
 365
 366         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 367         if (!entry)
 368                 return;
 369
 370         memcpy(entry->mac, mac, ETH_ALEN);
 371         spin_lock_bh(&bat_priv->vis_list_lock);
 372         list_add_tail(&entry->list, recv_list);
 373         spin_unlock_bh(&bat_priv->vis_list_lock);
 374 }
 375
 376 /* returns 1 if this mac is in the recv_list */
 377 static int batadv_recv_list_is_in(struct bat_priv *bat_priv,
 378                                   const struct list_head *recv_list,
 379                                   const char *mac)
 380 {
 381         const struct recvlist_node *entry;
 382
 383         spin_lock_bh(&bat_priv->vis_list_lock);
 384         list_for_each_entry(entry, recv_list, list) {
 385                 if (batadv_compare_eth(entry->mac, mac)) {
 386                         spin_unlock_bh(&bat_priv->vis_list_lock);
 387                         return 1;
 388                 }
 389         }
 390         spin_unlock_bh(&bat_priv->vis_list_lock);
 391         return 0;
 392 }
 393
 394 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 395  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 396  * is newer than old entries in the hash.
 397  */
 398 static struct vis_info *batadv_add_packet(struct bat_priv *bat_priv,
 399                                           struct vis_packet *vis_packet,
 400                                           int vis_info_len, int *is_new,
 401                                           int make_broadcast)
 402 {
 403         struct vis_info *info, *old_info;
 404         struct vis_packet *search_packet, *old_packet;
 405         struct vis_info search_elem;
 406         struct vis_packet *packet;
 407         int hash_added;
 408
 409         *is_new = 0;
 410         /* sanity check */
 411         if (!bat_priv->vis_hash)
 412                 return NULL;
 413
 414         /* see if the packet is already in vis_hash */
 415         search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
 416         if (!search_elem.skb_packet)
 417                 return NULL;
 418         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 419                                                      sizeof(*search_packet));
 420
 421         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 422         old_info = batadv_vis_hash_find(bat_priv, &search_elem);
 423         kfree_skb(search_elem.skb_packet);
 424
 425         if (old_info) {
 426                 old_packet = (struct vis_packet *)old_info->skb_packet->data;
 427                 if (!batadv_seq_after(ntohl(vis_packet->seqno),
 428                                       ntohl(old_packet->seqno))) {
 429                         if (old_packet->seqno == vis_packet->seqno) {
 430                                 batadv_recv_list_add(bat_priv,
 431                                                      &old_info->recv_list,
 432                                                      vis_packet->sender_orig);
 433                                 return old_info;
 434                         } else {
 435                                 /* newer packet is already in hash. */
 436                                 return NULL;
 437                         }
 438                 }
 439                 /* remove old entry */
 440                 batadv_hash_remove(bat_priv->vis_hash, batadv_vis_info_cmp,
 441                                    batadv_vis_info_choose, old_info);
 442                 batadv_send_list_del(old_info);
 443                 kref_put(&old_info->refcount, batadv_free_info);
 444         }
 445
 446         info = kmalloc(sizeof(*info), GFP_ATOMIC);
 447         if (!info)
 448                 return NULL;
 449
 450         info->skb_packet = dev_alloc_skb(sizeof(*packet) + vis_info_len +
 451                                          ETH_HLEN);
 452         if (!info->skb_packet) {
 453                 kfree(info);
 454                 return NULL;
 455         }
 456         skb_reserve(info->skb_packet, ETH_HLEN);
 457         packet = (struct vis_packet *)skb_put(info->skb_packet, sizeof(*packet)
 458                                               + vis_info_len);
 459
 460         kref_init(&info->refcount);
 461         INIT_LIST_HEAD(&info->send_list);
 462         INIT_LIST_HEAD(&info->recv_list);
 463         info->first_seen = jiffies;
 464         info->bat_priv = bat_priv;
 465         memcpy(packet, vis_packet, sizeof(*packet) + vis_info_len);
 466
 467         /* initialize and add new packet. */
 468         *is_new = 1;
 469
 470         /* Make it a broadcast packet, if required */
 471         if (make_broadcast)
 472                 memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 473
 474         /* repair if entries is longer than packet. */
 475         if (packet->entries * sizeof(struct vis_info_entry) > vis_info_len)
 476                 packet->entries = vis_info_len / sizeof(struct vis_info_entry);
 477
 478         batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 479
 480         /* try to add it */
 481         hash_added = batadv_hash_add(bat_priv->vis_hash, batadv_vis_info_cmp,
 482                                      batadv_vis_info_choose, info,
 483                                      &info->hash_entry);
 484         if (hash_added != 0) {
 485                 /* did not work (for some reason) */
 486                 kref_put(&info->refcount, batadv_free_info);
 487                 info = NULL;
 488         }
 489
 490         return info;
 491 }
 492
 493 /* handle the server sync packet, forward if needed. */
 494 void batadv_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 = batadv_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          */
 513         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 514                 batadv_send_list_add(bat_priv, info);
 515 end:
 516         spin_unlock_bh(&bat_priv->vis_hash_lock);
 517 }
 518
 519 /* handle an incoming client update packet and schedule forward if needed. */
 520 void batadv_receive_client_update_packet(struct bat_priv *bat_priv,
 521                                          struct vis_packet *vis_packet,
 522                                          int vis_info_len)
 523 {
 524         struct vis_info *info;
 525         struct vis_packet *packet;
 526         int is_new;
 527         int vis_server = atomic_read(&bat_priv->vis_mode);
 528         int are_target = 0;
 529
 530         /* clients shall not broadcast. */
 531         if (is_broadcast_ether_addr(vis_packet->target_orig))
 532                 return;
 533
 534         /* Are we the target for this VIS packet? */
 535         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 536             batadv_is_my_mac(vis_packet->target_orig))
 537                 are_target = 1;
 538
 539         spin_lock_bh(&bat_priv->vis_hash_lock);
 540         info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
 541                                  &is_new, are_target);
 542
 543         if (!info)
 544                 goto end;
 545         /* note that outdated packets will be dropped at this point. */
 546
 547         packet = (struct vis_packet *)info->skb_packet->data;
 548
 549         /* send only if we're the target server or ... */
 550         if (are_target && is_new) {
 551                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 552                 batadv_send_list_add(bat_priv, info);
 553
 554                 /* ... we're not the recipient (and thus need to forward). */
 555         } else if (!batadv_is_my_mac(packet->target_orig)) {
 556                 batadv_send_list_add(bat_priv, info);
 557         }
 558
 559 end:
 560         spin_unlock_bh(&bat_priv->vis_hash_lock);
 561 }
 562
 563 /* Walk the originators and find the VIS server with the best tq. Set the packet
 564  * address to its address and return the best_tq.
 565  *
 566  * Must be called with the originator hash locked
 567  */
 568 static int batadv_find_best_vis_server(struct bat_priv *bat_priv,
 569                                        struct vis_info *info)
 570 {
 571         struct hashtable_t *hash = bat_priv->orig_hash;
 572         struct neigh_node *router;
 573         struct hlist_node *node;
 574         struct hlist_head *head;
 575         struct orig_node *orig_node;
 576         struct vis_packet *packet;
 577         int best_tq = -1;
 578         uint32_t i;
 579
 580         packet = (struct vis_packet *)info->skb_packet->data;
 581
 582         for (i = 0; i < hash->size; i++) {
 583                 head = &hash->table[i];
 584
 585                 rcu_read_lock();
 586                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 587                         router = batadv_orig_node_get_router(orig_node);
 588                         if (!router)
 589                                 continue;
 590
 591                         if ((orig_node->flags & VIS_SERVER) &&
 592                             (router->tq_avg > best_tq)) {
 593                                 best_tq = router->tq_avg;
 594                                 memcpy(packet->target_orig, orig_node->orig,
 595                                        ETH_ALEN);
 596                         }
 597                         batadv_neigh_node_free_ref(router);
 598                 }
 599                 rcu_read_unlock();
 600         }
 601
 602         return best_tq;
 603 }
 604
 605 /* Return true if the vis packet is full. */
 606 static bool batadv_vis_packet_full(const struct vis_info *info)
 607 {
 608         const struct vis_packet *packet;
 609         packet = (struct vis_packet *)info->skb_packet->data;
 610
 611         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 612                 < packet->entries + 1)
 613                 return true;
 614         return false;
 615 }
 616
 617 /* generates a packet of own vis data,
 618  * returns 0 on success, -1 if no packet could be generated
 619  */
 620 static int batadv_generate_vis_packet(struct bat_priv *bat_priv)
 621 {
 622         struct hashtable_t *hash = bat_priv->orig_hash;
 623         struct hlist_node *node;
 624         struct hlist_head *head;
 625         struct orig_node *orig_node;
 626         struct neigh_node *router;
 627         struct vis_info *info = bat_priv->my_vis_info;
 628         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 629         struct vis_info_entry *entry;
 630         struct tt_common_entry *tt_common_entry;
 631         int best_tq = -1;
 632         uint32_t i;
 633
 634         info->first_seen = jiffies;
 635         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 636
 637         memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
 638         packet->header.ttl = TTL;
 639         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 640         packet->entries = 0;
 641         skb_trim(info->skb_packet, sizeof(*packet));
 642
 643         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 644                 best_tq = batadv_find_best_vis_server(bat_priv, info);
 645
 646                 if (best_tq < 0)
 647                         return best_tq;
 648         }
 649
 650         for (i = 0; i < hash->size; i++) {
 651                 head = &hash->table[i];
 652
 653                 rcu_read_lock();
 654                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 655                         router = batadv_orig_node_get_router(orig_node);
 656                         if (!router)
 657                                 continue;
 658
 659                         if (!batadv_compare_eth(router->addr, orig_node->orig))
 660                                 goto next;
 661
 662                         if (router->if_incoming->if_status != IF_ACTIVE)
 663                                 goto next;
 664
 665                         if (router->tq_avg < 1)
 666                                 goto next;
 667
 668                         /* fill one entry into buffer. */
 669                         entry = (struct vis_info_entry *)
 670                                       skb_put(info->skb_packet, sizeof(*entry));
 671                         memcpy(entry->src,
 672                                router->if_incoming->net_dev->dev_addr,
 673                                ETH_ALEN);
 674                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 675                         entry->quality = router->tq_avg;
 676                         packet->entries++;
 677
 678 next:
 679                         batadv_neigh_node_free_ref(router);
 680
 681                         if (batadv_vis_packet_full(info))
 682                                 goto unlock;
 683                 }
 684                 rcu_read_unlock();
 685         }
 686
 687         hash = bat_priv->tt_local_hash;
 688
 689         for (i = 0; i < hash->size; i++) {
 690                 head = &hash->table[i];
 691
 692                 rcu_read_lock();
 693                 hlist_for_each_entry_rcu(tt_common_entry, node, head,
 694                                          hash_entry) {
 695                         entry = (struct vis_info_entry *)
 696                                         skb_put(info->skb_packet,
 697                                                 sizeof(*entry));
 698                         memset(entry->src, 0, ETH_ALEN);
 699                         memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
 700                         entry->quality = 0; /* 0 means TT */
 701                         packet->entries++;
 702
 703                         if (batadv_vis_packet_full(info))
 704                                 goto unlock;
 705                 }
 706                 rcu_read_unlock();
 707         }
 708
 709         return 0;
 710
 711 unlock:
 712         rcu_read_unlock();
 713         return 0;
 714 }
 715
 716 /* free old vis packets. Must be called with this vis_hash_lock
 717  * held
 718  */
 719 static void batadv_purge_vis_packets(struct bat_priv *bat_priv)
 720 {
 721         uint32_t i;
 722         struct hashtable_t *hash = bat_priv->vis_hash;
 723         struct hlist_node *node, *node_tmp;
 724         struct hlist_head *head;
 725         struct vis_info *info;
 726
 727         for (i = 0; i < hash->size; i++) {
 728                 head = &hash->table[i];
 729
 730                 hlist_for_each_entry_safe(info, node, node_tmp,
 731                                           head, hash_entry) {
 732                         /* never purge own data. */
 733                         if (info == bat_priv->my_vis_info)
 734                                 continue;
 735
 736                         if (batadv_has_timed_out(info->first_seen,
 737                                                  VIS_TIMEOUT)) {
 738                                 hlist_del(node);
 739                                 batadv_send_list_del(info);
 740                                 kref_put(&info->refcount, batadv_free_info);
 741                         }
 742                 }
 743         }
 744 }
 745
 746 static void batadv_broadcast_vis_packet(struct bat_priv *bat_priv,
 747                                         struct vis_info *info)
 748 {
 749         struct neigh_node *router;
 750         struct hashtable_t *hash = bat_priv->orig_hash;
 751         struct hlist_node *node;
 752         struct hlist_head *head;
 753         struct orig_node *orig_node;
 754         struct vis_packet *packet;
 755         struct sk_buff *skb;
 756         struct hard_iface *hard_iface;
 757         uint8_t dstaddr[ETH_ALEN];
 758         uint32_t i;
 759
 760
 761         packet = (struct vis_packet *)info->skb_packet->data;
 762
 763         /* send to all routers in range. */
 764         for (i = 0; i < hash->size; i++) {
 765                 head = &hash->table[i];
 766
 767                 rcu_read_lock();
 768                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 769                         /* if it's a vis server and reachable, send it. */
 770                         if (!(orig_node->flags & VIS_SERVER))
 771                                 continue;
 772
 773                         router = batadv_orig_node_get_router(orig_node);
 774                         if (!router)
 775                                 continue;
 776
 777                         /* don't send it if we already received the packet from
 778                          * this node.
 779                          */
 780                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
 781                                                    orig_node->orig)) {
 782                                 batadv_neigh_node_free_ref(router);
 783                                 continue;
 784                         }
 785
 786                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 787                         hard_iface = router->if_incoming;
 788                         memcpy(dstaddr, router->addr, ETH_ALEN);
 789
 790                         batadv_neigh_node_free_ref(router);
 791
 792                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 793                         if (skb)
 794                                 batadv_send_skb_packet(skb, hard_iface,
 795                                                        dstaddr);
 796
 797                 }
 798                 rcu_read_unlock();
 799         }
 800 }
 801
 802 static void batadv_unicast_vis_packet(struct bat_priv *bat_priv,
 803                                       struct vis_info *info)
 804 {
 805         struct orig_node *orig_node;
 806         struct neigh_node *router = NULL;
 807         struct sk_buff *skb;
 808         struct vis_packet *packet;
 809
 810         packet = (struct vis_packet *)info->skb_packet->data;
 811
 812         orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
 813         if (!orig_node)
 814                 goto out;
 815
 816         router = batadv_orig_node_get_router(orig_node);
 817         if (!router)
 818                 goto out;
 819
 820         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 821         if (skb)
 822                 batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 823
 824 out:
 825         if (router)
 826                 batadv_neigh_node_free_ref(router);
 827         if (orig_node)
 828                 batadv_orig_node_free_ref(orig_node);
 829 }
 830
 831 /* only send one vis packet. called from batadv_send_vis_packets() */
 832 static void batadv_send_vis_packet(struct bat_priv *bat_priv,
 833                                    struct vis_info *info)
 834 {
 835         struct hard_iface *primary_if;
 836         struct vis_packet *packet;
 837
 838         primary_if = batadv_primary_if_get_selected(bat_priv);
 839         if (!primary_if)
 840                 goto out;
 841
 842         packet = (struct vis_packet *)info->skb_packet->data;
 843         if (packet->header.ttl < 2) {
 844                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 845                 goto out;
 846         }
 847
 848         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 849         packet->header.ttl--;
 850
 851         if (is_broadcast_ether_addr(packet->target_orig))
 852                 batadv_broadcast_vis_packet(bat_priv, info);
 853         else
 854                 batadv_unicast_vis_packet(bat_priv, info);
 855         packet->header.ttl++; /* restore TTL */
 856
 857 out:
 858         if (primary_if)
 859                 batadv_hardif_free_ref(primary_if);
 860 }
 861
 862 /* called from timer; send (and maybe generate) vis packet. */
 863 static void batadv_send_vis_packets(struct work_struct *work)
 864 {
 865         struct delayed_work *delayed_work =
 866                 container_of(work, struct delayed_work, work);
 867         struct bat_priv *bat_priv =
 868                 container_of(delayed_work, struct bat_priv, vis_work);
 869         struct vis_info *info;
 870
 871         spin_lock_bh(&bat_priv->vis_hash_lock);
 872         batadv_purge_vis_packets(bat_priv);
 873
 874         if (batadv_generate_vis_packet(bat_priv) == 0) {
 875                 /* schedule if generation was successful */
 876                 batadv_send_list_add(bat_priv, bat_priv->my_vis_info);
 877         }
 878
 879         while (!list_empty(&bat_priv->vis_send_list)) {
 880                 info = list_first_entry(&bat_priv->vis_send_list,
 881                                         typeof(*info), send_list);
 882
 883                 kref_get(&info->refcount);
 884                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 885
 886                 batadv_send_vis_packet(bat_priv, info);
 887
 888                 spin_lock_bh(&bat_priv->vis_hash_lock);
 889                 batadv_send_list_del(info);
 890                 kref_put(&info->refcount, batadv_free_info);
 891         }
 892         spin_unlock_bh(&bat_priv->vis_hash_lock);
 893         batadv_start_vis_timer(bat_priv);
 894 }
 895
 896 /* init the vis server. this may only be called when if_list is already
 897  * initialized (e.g. bat0 is initialized, interfaces have been added)
 898  */
 899 int batadv_vis_init(struct bat_priv *bat_priv)
 900 {
 901         struct vis_packet *packet;
 902         int hash_added;
 903
 904         if (bat_priv->vis_hash)
 905                 return 0;
 906
 907         spin_lock_bh(&bat_priv->vis_hash_lock);
 908
 909         bat_priv->vis_hash = batadv_hash_new(256);
 910         if (!bat_priv->vis_hash) {
 911                 pr_err("Can't initialize vis_hash\n");
 912                 goto err;
 913         }
 914
 915         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 916         if (!bat_priv->my_vis_info)
 917                 goto err;
 918
 919         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(sizeof(*packet) +
 920                                                           MAX_VIS_PACKET_SIZE +
 921                                                           ETH_HLEN);
 922         if (!bat_priv->my_vis_info->skb_packet)
 923                 goto free_info;
 924
 925         skb_reserve(bat_priv->my_vis_info->skb_packet, ETH_HLEN);
 926         packet = (struct vis_packet *)skb_put(bat_priv->my_vis_info->skb_packet,
 927                                               sizeof(*packet));
 928
 929         /* prefill the vis info */
 930         bat_priv->my_vis_info->first_seen = jiffies -
 931                                                 msecs_to_jiffies(VIS_INTERVAL);
 932         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 933         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 934         kref_init(&bat_priv->my_vis_info->refcount);
 935         bat_priv->my_vis_info->bat_priv = bat_priv;
 936         packet->header.version = COMPAT_VERSION;
 937         packet->header.packet_type = BAT_VIS;
 938         packet->header.ttl = TTL;
 939         packet->seqno = 0;
 940         packet->entries = 0;
 941
 942         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 943
 944         hash_added = batadv_hash_add(bat_priv->vis_hash, batadv_vis_info_cmp,
 945                                      batadv_vis_info_choose,
 946                                      bat_priv->my_vis_info,
 947                                      &bat_priv->my_vis_info->hash_entry);
 948         if (hash_added != 0) {
 949                 pr_err("Can't add own vis packet into hash\n");
 950                 /* not in hash, need to remove it manually. */
 951                 kref_put(&bat_priv->my_vis_info->refcount, batadv_free_info);
 952                 goto err;
 953         }
 954
 955         spin_unlock_bh(&bat_priv->vis_hash_lock);
 956         batadv_start_vis_timer(bat_priv);
 957         return 0;
 958
 959 free_info:
 960         kfree(bat_priv->my_vis_info);
 961         bat_priv->my_vis_info = NULL;
 962 err:
 963         spin_unlock_bh(&bat_priv->vis_hash_lock);
 964         batadv_vis_quit(bat_priv);
 965         return -ENOMEM;
 966 }
 967
 968 /* Decrease the reference count on a hash item info */
 969 static void batadv_free_info_ref(struct hlist_node *node, void *arg)
 970 {
 971         struct vis_info *info;
 972
 973         info = container_of(node, struct vis_info, hash_entry);
 974         batadv_send_list_del(info);
 975         kref_put(&info->refcount, batadv_free_info);
 976 }
 977
 978 /* shutdown vis-server */
 979 void batadv_vis_quit(struct bat_priv *bat_priv)
 980 {
 981         if (!bat_priv->vis_hash)
 982                 return;
 983
 984         cancel_delayed_work_sync(&bat_priv->vis_work);
 985
 986         spin_lock_bh(&bat_priv->vis_hash_lock);
 987         /* properly remove, kill timers ... */
 988         batadv_hash_delete(bat_priv->vis_hash, batadv_free_info_ref, NULL);
 989         bat_priv->vis_hash = NULL;
 990         bat_priv->my_vis_info = NULL;
 991         spin_unlock_bh(&bat_priv->vis_hash_lock);
 992 }
 993
 994 /* schedule packets for (re)transmission */
 995 static void batadv_start_vis_timer(struct bat_priv *bat_priv)
 996 {
 997         INIT_DELAYED_WORK(&bat_priv->vis_work, batadv_send_vis_packets);
 998         queue_delayed_work(batadv_event_workqueue, &bat_priv->vis_work,
 999                            msecs_to_jiffies(VIS_INTERVAL));
1000 }