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(struct hlist_node *node, void *data2)
  72 {
  73         struct vis_info *d1, *d2;
  74         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(void *data, int size)
  86 {
  87         struct vis_info *vis_info = data;
  88         struct vis_packet *packet;
  89         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                                       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, (void *)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, struct hlist_head *if_list)
 160 {
 161         struct if_list_entry *entry;
 162         struct hlist_node *pos;
 163         size_t len = 0;
 164
 165         hlist_for_each_entry(entry, pos, if_list, list) {
 166                 if (entry->primary)
 167                         len += sprintf(buff + len, "PRIMARY, ");
 168                 else
 169                         len += sprintf(buff + len,  "SEC %pM, ", entry->addr);
 170         }
 171
 172         return len;
 173 }
 174
 175 static size_t vis_data_count_prim_sec(struct hlist_head *if_list)
 176 {
 177         struct if_list_entry *entry;
 178         struct hlist_node *pos;
 179         size_t count = 0;
 180
 181         hlist_for_each_entry(entry, pos, if_list, list) {
 182                 if (entry->primary)
 183                         count += 9;
 184                 else
 185                         count += 23;
 186         }
 187
 188         return count;
 189 }
 190
 191 /* read an entry  */
 192 static ssize_t vis_data_read_entry(char *buff, struct vis_info_entry *entry,
 193                                    uint8_t *src, bool primary)
 194 {
 195         /* maximal length: max(4+17+2, 3+17+1+3+2) == 26 */
 196         if (primary && entry->quality == 0)
 197                 return sprintf(buff, "TT %pM, ", entry->dest);
 198         else if (compare_eth(entry->src, src))
 199                 return sprintf(buff, "TQ %pM %d, ", entry->dest,
 200                                entry->quality);
 201
 202         return 0;
 203 }
 204
 205 int vis_seq_print_text(struct seq_file *seq, void *offset)
 206 {
 207         struct hard_iface *primary_if;
 208         struct hlist_node *node;
 209         struct hlist_head *head;
 210         struct vis_info *info;
 211         struct vis_packet *packet;
 212         struct vis_info_entry *entries;
 213         struct net_device *net_dev = (struct net_device *)seq->private;
 214         struct bat_priv *bat_priv = netdev_priv(net_dev);
 215         struct hashtable_t *hash = bat_priv->vis_hash;
 216         HLIST_HEAD(vis_if_list);
 217         struct if_list_entry *entry;
 218         struct hlist_node *pos, *n;
 219         int i, j, ret = 0;
 220         int vis_server = atomic_read(&bat_priv->vis_mode);
 221         size_t buff_pos, buf_size;
 222         char *buff;
 223         int compare;
 224
 225         primary_if = primary_if_get_selected(bat_priv);
 226         if (!primary_if)
 227                 goto out;
 228
 229         if (vis_server == VIS_TYPE_CLIENT_UPDATE)
 230                 goto out;
 231
 232         buf_size = 1;
 233         /* Estimate length */
 234         spin_lock_bh(&bat_priv->vis_hash_lock);
 235         for (i = 0; i < hash->size; i++) {
 236                 head = &hash->table[i];
 237
 238                 rcu_read_lock();
 239                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 240                         packet = (struct vis_packet *)info->skb_packet->data;
 241                         entries = (struct vis_info_entry *)
 242                                 ((char *)packet + sizeof(struct vis_packet));
 243
 244                         for (j = 0; j < packet->entries; j++) {
 245                                 if (entries[j].quality == 0)
 246                                         continue;
 247                                 compare =
 248                                  compare_eth(entries[j].src, packet->vis_orig);
 249                                 vis_data_insert_interface(entries[j].src,
 250                                                           &vis_if_list,
 251                                                           compare);
 252                         }
 253
 254                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 255                                 buf_size += 18 + 26 * packet->entries;
 256
 257                                 /* add primary/secondary records */
 258                                 if (compare_eth(entry->addr, packet->vis_orig))
 259                                         buf_size +=
 260                                           vis_data_count_prim_sec(&vis_if_list);
 261
 262                                 buf_size += 1;
 263                         }
 264
 265                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 266                                                   list) {
 267                                 hlist_del(&entry->list);
 268                                 kfree(entry);
 269                         }
 270                 }
 271                 rcu_read_unlock();
 272         }
 273
 274         buff = kmalloc(buf_size, GFP_ATOMIC);
 275         if (!buff) {
 276                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 277                 ret = -ENOMEM;
 278                 goto out;
 279         }
 280         buff[0] = '\0';
 281         buff_pos = 0;
 282
 283         for (i = 0; i < hash->size; i++) {
 284                 head = &hash->table[i];
 285
 286                 rcu_read_lock();
 287                 hlist_for_each_entry_rcu(info, node, head, hash_entry) {
 288                         packet = (struct vis_packet *)info->skb_packet->data;
 289                         entries = (struct vis_info_entry *)
 290                                 ((char *)packet + sizeof(struct vis_packet));
 291
 292                         for (j = 0; j < packet->entries; j++) {
 293                                 if (entries[j].quality == 0)
 294                                         continue;
 295                                 compare =
 296                                  compare_eth(entries[j].src, packet->vis_orig);
 297                                 vis_data_insert_interface(entries[j].src,
 298                                                           &vis_if_list,
 299                                                           compare);
 300                         }
 301
 302                         hlist_for_each_entry(entry, pos, &vis_if_list, list) {
 303                                 buff_pos += sprintf(buff + buff_pos, "%pM,",
 304                                                 entry->addr);
 305
 306                                 for (j = 0; j < packet->entries; j++)
 307                                         buff_pos += vis_data_read_entry(
 308                                                         buff + buff_pos,
 309                                                         &entries[j],
 310                                                         entry->addr,
 311                                                         entry->primary);
 312
 313                                 /* add primary/secondary records */
 314                                 if (compare_eth(entry->addr, packet->vis_orig))
 315                                         buff_pos +=
 316                                          vis_data_read_prim_sec(buff + buff_pos,
 317                                                                 &vis_if_list);
 318
 319                                 buff_pos += sprintf(buff + buff_pos, "\n");
 320                         }
 321
 322                         hlist_for_each_entry_safe(entry, pos, n, &vis_if_list,
 323                                                   list) {
 324                                 hlist_del(&entry->list);
 325                                 kfree(entry);
 326                         }
 327                 }
 328                 rcu_read_unlock();
 329         }
 330
 331         spin_unlock_bh(&bat_priv->vis_hash_lock);
 332
 333         seq_printf(seq, "%s", buff);
 334         kfree(buff);
 335
 336 out:
 337         if (primary_if)
 338                 hardif_free_ref(primary_if);
 339         return ret;
 340 }
 341
 342 /* add the info packet to the send list, if it was not
 343  * already linked in. */
 344 static void send_list_add(struct bat_priv *bat_priv, struct vis_info *info)
 345 {
 346         if (list_empty(&info->send_list)) {
 347                 kref_get(&info->refcount);
 348                 list_add_tail(&info->send_list, &bat_priv->vis_send_list);
 349         }
 350 }
 351
 352 /* delete the info packet from the send list, if it was
 353  * linked in. */
 354 static void send_list_del(struct vis_info *info)
 355 {
 356         if (!list_empty(&info->send_list)) {
 357                 list_del_init(&info->send_list);
 358                 kref_put(&info->refcount, free_info);
 359         }
 360 }
 361
 362 /* tries to add one entry to the receive list. */
 363 static void recv_list_add(struct bat_priv *bat_priv,
 364                           struct list_head *recv_list, char *mac)
 365 {
 366         struct recvlist_node *entry;
 367
 368         entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC);
 369         if (!entry)
 370                 return;
 371
 372         memcpy(entry->mac, mac, ETH_ALEN);
 373         spin_lock_bh(&bat_priv->vis_list_lock);
 374         list_add_tail(&entry->list, recv_list);
 375         spin_unlock_bh(&bat_priv->vis_list_lock);
 376 }
 377
 378 /* returns 1 if this mac is in the recv_list */
 379 static int recv_list_is_in(struct bat_priv *bat_priv,
 380                            struct list_head *recv_list, char *mac)
 381 {
 382         struct recvlist_node *entry;
 383
 384         spin_lock_bh(&bat_priv->vis_list_lock);
 385         list_for_each_entry(entry, recv_list, list) {
 386                 if (compare_eth(entry->mac, mac)) {
 387                         spin_unlock_bh(&bat_priv->vis_list_lock);
 388                         return 1;
 389                 }
 390         }
 391         spin_unlock_bh(&bat_priv->vis_list_lock);
 392         return 0;
 393 }
 394
 395 /* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old,
 396  * broken.. ).  vis hash must be locked outside.  is_new is set when the packet
 397  * is newer than old entries in the hash. */
 398 static struct vis_info *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(struct vis_packet));
 416         if (!search_elem.skb_packet)
 417                 return NULL;
 418         search_packet = (struct vis_packet *)skb_put(search_elem.skb_packet,
 419                                                      sizeof(struct vis_packet));
 420
 421         memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
 422         old_info = 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 (!seq_after(ntohl(vis_packet->seqno),
 428                                ntohl(old_packet->seqno))) {
 429                         if (old_packet->seqno == vis_packet->seqno) {
 430                                 recv_list_add(bat_priv, &old_info->recv_list,
 431                                               vis_packet->sender_orig);
 432                                 return old_info;
 433                         } else {
 434                                 /* newer packet is already in hash. */
 435                                 return NULL;
 436                         }
 437                 }
 438                 /* remove old entry */
 439                 hash_remove(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 440                             old_info);
 441                 send_list_del(old_info);
 442                 kref_put(&old_info->refcount, free_info);
 443         }
 444
 445         info = kmalloc(sizeof(struct vis_info), GFP_ATOMIC);
 446         if (!info)
 447                 return NULL;
 448
 449         info->skb_packet = dev_alloc_skb(sizeof(struct vis_packet) +
 450                                          vis_info_len + sizeof(struct ethhdr));
 451         if (!info->skb_packet) {
 452                 kfree(info);
 453                 return NULL;
 454         }
 455         skb_reserve(info->skb_packet, sizeof(struct ethhdr));
 456         packet = (struct vis_packet *)skb_put(info->skb_packet,
 457                                               sizeof(struct vis_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(struct vis_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, 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         recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
 479
 480         /* try to add it */
 481         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 482                               info, &info->hash_entry);
 483         if (hash_added < 0) {
 484                 /* did not work (for some reason) */
 485                 kref_put(&info->refcount, free_info);
 486                 info = NULL;
 487         }
 488
 489         return info;
 490 }
 491
 492 /* handle the server sync packet, forward if needed. */
 493 void receive_server_sync_packet(struct bat_priv *bat_priv,
 494                                 struct vis_packet *vis_packet,
 495                                 int vis_info_len)
 496 {
 497         struct vis_info *info;
 498         int is_new, make_broadcast;
 499         int vis_server = atomic_read(&bat_priv->vis_mode);
 500
 501         make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC);
 502
 503         spin_lock_bh(&bat_priv->vis_hash_lock);
 504         info = add_packet(bat_priv, vis_packet, vis_info_len,
 505                           &is_new, make_broadcast);
 506         if (!info)
 507                 goto end;
 508
 509         /* only if we are server ourselves and packet is newer than the one in
 510          * hash.*/
 511         if (vis_server == VIS_TYPE_SERVER_SYNC && is_new)
 512                 send_list_add(bat_priv, info);
 513 end:
 514         spin_unlock_bh(&bat_priv->vis_hash_lock);
 515 }
 516
 517 /* handle an incoming client update packet and schedule forward if needed. */
 518 void receive_client_update_packet(struct bat_priv *bat_priv,
 519                                   struct vis_packet *vis_packet,
 520                                   int vis_info_len)
 521 {
 522         struct vis_info *info;
 523         struct vis_packet *packet;
 524         int is_new;
 525         int vis_server = atomic_read(&bat_priv->vis_mode);
 526         int are_target = 0;
 527
 528         /* clients shall not broadcast. */
 529         if (is_broadcast_ether_addr(vis_packet->target_orig))
 530                 return;
 531
 532         /* Are we the target for this VIS packet? */
 533         if (vis_server == VIS_TYPE_SERVER_SYNC  &&
 534             is_my_mac(vis_packet->target_orig))
 535                 are_target = 1;
 536
 537         spin_lock_bh(&bat_priv->vis_hash_lock);
 538         info = add_packet(bat_priv, vis_packet, vis_info_len,
 539                           &is_new, are_target);
 540
 541         if (!info)
 542                 goto end;
 543         /* note that outdated packets will be dropped at this point. */
 544
 545         packet = (struct vis_packet *)info->skb_packet->data;
 546
 547         /* send only if we're the target server or ... */
 548         if (are_target && is_new) {
 549                 packet->vis_type = VIS_TYPE_SERVER_SYNC;        /* upgrade! */
 550                 send_list_add(bat_priv, info);
 551
 552                 /* ... we're not the recipient (and thus need to forward). */
 553         } else if (!is_my_mac(packet->target_orig)) {
 554                 send_list_add(bat_priv, info);
 555         }
 556
 557 end:
 558         spin_unlock_bh(&bat_priv->vis_hash_lock);
 559 }
 560
 561 /* Walk the originators and find the VIS server with the best tq. Set the packet
 562  * address to its address and return the best_tq.
 563  *
 564  * Must be called with the originator hash locked */
 565 static int find_best_vis_server(struct bat_priv *bat_priv,
 566                                 struct vis_info *info)
 567 {
 568         struct hashtable_t *hash = bat_priv->orig_hash;
 569         struct neigh_node *router;
 570         struct hlist_node *node;
 571         struct hlist_head *head;
 572         struct orig_node *orig_node;
 573         struct vis_packet *packet;
 574         int best_tq = -1, i;
 575
 576         packet = (struct vis_packet *)info->skb_packet->data;
 577
 578         for (i = 0; i < hash->size; i++) {
 579                 head = &hash->table[i];
 580
 581                 rcu_read_lock();
 582                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 583                         router = orig_node_get_router(orig_node);
 584                         if (!router)
 585                                 continue;
 586
 587                         if ((orig_node->flags & VIS_SERVER) &&
 588                             (router->tq_avg > best_tq)) {
 589                                 best_tq = router->tq_avg;
 590                                 memcpy(packet->target_orig, orig_node->orig,
 591                                        ETH_ALEN);
 592                         }
 593                         neigh_node_free_ref(router);
 594                 }
 595                 rcu_read_unlock();
 596         }
 597
 598         return best_tq;
 599 }
 600
 601 /* Return true if the vis packet is full. */
 602 static bool vis_packet_full(struct vis_info *info)
 603 {
 604         struct vis_packet *packet;
 605         packet = (struct vis_packet *)info->skb_packet->data;
 606
 607         if (MAX_VIS_PACKET_SIZE / sizeof(struct vis_info_entry)
 608                 < packet->entries + 1)
 609                 return true;
 610         return false;
 611 }
 612
 613 /* generates a packet of own vis data,
 614  * returns 0 on success, -1 if no packet could be generated */
 615 static int generate_vis_packet(struct bat_priv *bat_priv)
 616 {
 617         struct hashtable_t *hash = bat_priv->orig_hash;
 618         struct hlist_node *node;
 619         struct hlist_head *head;
 620         struct orig_node *orig_node;
 621         struct neigh_node *router;
 622         struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
 623         struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
 624         struct vis_info_entry *entry;
 625         struct tt_local_entry *tt_local_entry;
 626         int best_tq = -1, i;
 627
 628         info->first_seen = jiffies;
 629         packet->vis_type = atomic_read(&bat_priv->vis_mode);
 630
 631         memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
 632         packet->ttl = TTL;
 633         packet->seqno = htonl(ntohl(packet->seqno) + 1);
 634         packet->entries = 0;
 635         skb_trim(info->skb_packet, sizeof(struct vis_packet));
 636
 637         if (packet->vis_type == VIS_TYPE_CLIENT_UPDATE) {
 638                 best_tq = find_best_vis_server(bat_priv, info);
 639
 640                 if (best_tq < 0)
 641                         return -1;
 642         }
 643
 644         for (i = 0; i < hash->size; i++) {
 645                 head = &hash->table[i];
 646
 647                 rcu_read_lock();
 648                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 649                         router = orig_node_get_router(orig_node);
 650                         if (!router)
 651                                 continue;
 652
 653                         if (!compare_eth(router->addr, orig_node->orig))
 654                                 goto next;
 655
 656                         if (router->if_incoming->if_status != IF_ACTIVE)
 657                                 goto next;
 658
 659                         if (router->tq_avg < 1)
 660                                 goto next;
 661
 662                         /* fill one entry into buffer. */
 663                         entry = (struct vis_info_entry *)
 664                                       skb_put(info->skb_packet, sizeof(*entry));
 665                         memcpy(entry->src,
 666                                router->if_incoming->net_dev->dev_addr,
 667                                ETH_ALEN);
 668                         memcpy(entry->dest, orig_node->orig, ETH_ALEN);
 669                         entry->quality = router->tq_avg;
 670                         packet->entries++;
 671
 672 next:
 673                         neigh_node_free_ref(router);
 674
 675                         if (vis_packet_full(info))
 676                                 goto unlock;
 677                 }
 678                 rcu_read_unlock();
 679         }
 680
 681         hash = bat_priv->tt_local_hash;
 682
 683         spin_lock_bh(&bat_priv->tt_lhash_lock);
 684         for (i = 0; i < hash->size; i++) {
 685                 head = &hash->table[i];
 686
 687                 hlist_for_each_entry(tt_local_entry, node, head, hash_entry) {
 688                         entry = (struct vis_info_entry *)
 689                                         skb_put(info->skb_packet,
 690                                                 sizeof(*entry));
 691                         memset(entry->src, 0, ETH_ALEN);
 692                         memcpy(entry->dest, tt_local_entry->addr, ETH_ALEN);
 693                         entry->quality = 0; /* 0 means TT */
 694                         packet->entries++;
 695
 696                         if (vis_packet_full(info)) {
 697                                 spin_unlock_bh(&bat_priv->tt_lhash_lock);
 698                                 return 0;
 699                         }
 700                 }
 701         }
 702
 703         spin_unlock_bh(&bat_priv->tt_lhash_lock);
 704         return 0;
 705
 706 unlock:
 707         rcu_read_unlock();
 708         return 0;
 709 }
 710
 711 /* free old vis packets. Must be called with this vis_hash_lock
 712  * held */
 713 static void purge_vis_packets(struct bat_priv *bat_priv)
 714 {
 715         int i;
 716         struct hashtable_t *hash = bat_priv->vis_hash;
 717         struct hlist_node *node, *node_tmp;
 718         struct hlist_head *head;
 719         struct vis_info *info;
 720
 721         for (i = 0; i < hash->size; i++) {
 722                 head = &hash->table[i];
 723
 724                 hlist_for_each_entry_safe(info, node, node_tmp,
 725                                           head, hash_entry) {
 726                         /* never purge own data. */
 727                         if (info == bat_priv->my_vis_info)
 728                                 continue;
 729
 730                         if (time_after(jiffies,
 731                                        info->first_seen + VIS_TIMEOUT * HZ)) {
 732                                 hlist_del(node);
 733                                 send_list_del(info);
 734                                 kref_put(&info->refcount, free_info);
 735                         }
 736                 }
 737         }
 738 }
 739
 740 static void broadcast_vis_packet(struct bat_priv *bat_priv,
 741                                  struct vis_info *info)
 742 {
 743         struct neigh_node *router;
 744         struct hashtable_t *hash = bat_priv->orig_hash;
 745         struct hlist_node *node;
 746         struct hlist_head *head;
 747         struct orig_node *orig_node;
 748         struct vis_packet *packet;
 749         struct sk_buff *skb;
 750         struct hard_iface *hard_iface;
 751         uint8_t dstaddr[ETH_ALEN];
 752         int i;
 753
 754
 755         packet = (struct vis_packet *)info->skb_packet->data;
 756
 757         /* send to all routers in range. */
 758         for (i = 0; i < hash->size; i++) {
 759                 head = &hash->table[i];
 760
 761                 rcu_read_lock();
 762                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 763                         /* if it's a vis server and reachable, send it. */
 764                         if (!(orig_node->flags & VIS_SERVER))
 765                                 continue;
 766
 767                         router = orig_node_get_router(orig_node);
 768                         if (!router)
 769                                 continue;
 770
 771                         /* don't send it if we already received the packet from
 772                          * this node. */
 773                         if (recv_list_is_in(bat_priv, &info->recv_list,
 774                                             orig_node->orig)) {
 775                                 neigh_node_free_ref(router);
 776                                 continue;
 777                         }
 778
 779                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
 780                         hard_iface = router->if_incoming;
 781                         memcpy(dstaddr, router->addr, ETH_ALEN);
 782
 783                         neigh_node_free_ref(router);
 784
 785                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 786                         if (skb)
 787                                 send_skb_packet(skb, hard_iface, dstaddr);
 788
 789                 }
 790                 rcu_read_unlock();
 791         }
 792 }
 793
 794 static void unicast_vis_packet(struct bat_priv *bat_priv,
 795                                struct vis_info *info)
 796 {
 797         struct orig_node *orig_node;
 798         struct neigh_node *router = NULL;
 799         struct sk_buff *skb;
 800         struct vis_packet *packet;
 801
 802         packet = (struct vis_packet *)info->skb_packet->data;
 803
 804         orig_node = orig_hash_find(bat_priv, packet->target_orig);
 805         if (!orig_node)
 806                 goto out;
 807
 808         router = orig_node_get_router(orig_node);
 809         if (!router)
 810                 goto out;
 811
 812         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
 813         if (skb)
 814                 send_skb_packet(skb, router->if_incoming, router->addr);
 815
 816 out:
 817         if (router)
 818                 neigh_node_free_ref(router);
 819         if (orig_node)
 820                 orig_node_free_ref(orig_node);
 821 }
 822
 823 /* only send one vis packet. called from send_vis_packets() */
 824 static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 825 {
 826         struct hard_iface *primary_if;
 827         struct vis_packet *packet;
 828
 829         primary_if = primary_if_get_selected(bat_priv);
 830         if (!primary_if)
 831                 goto out;
 832
 833         packet = (struct vis_packet *)info->skb_packet->data;
 834         if (packet->ttl < 2) {
 835                 pr_debug("Error - can't send vis packet: ttl exceeded\n");
 836                 goto out;
 837         }
 838
 839         memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 840         packet->ttl--;
 841
 842         if (is_broadcast_ether_addr(packet->target_orig))
 843                 broadcast_vis_packet(bat_priv, info);
 844         else
 845                 unicast_vis_packet(bat_priv, info);
 846         packet->ttl++; /* restore TTL */
 847
 848 out:
 849         if (primary_if)
 850                 hardif_free_ref(primary_if);
 851 }
 852
 853 /* called from timer; send (and maybe generate) vis packet. */
 854 static void send_vis_packets(struct work_struct *work)
 855 {
 856         struct delayed_work *delayed_work =
 857                 container_of(work, struct delayed_work, work);
 858         struct bat_priv *bat_priv =
 859                 container_of(delayed_work, struct bat_priv, vis_work);
 860         struct vis_info *info;
 861
 862         spin_lock_bh(&bat_priv->vis_hash_lock);
 863         purge_vis_packets(bat_priv);
 864
 865         if (generate_vis_packet(bat_priv) == 0) {
 866                 /* schedule if generation was successful */
 867                 send_list_add(bat_priv, bat_priv->my_vis_info);
 868         }
 869
 870         while (!list_empty(&bat_priv->vis_send_list)) {
 871                 info = list_first_entry(&bat_priv->vis_send_list,
 872                                         typeof(*info), send_list);
 873
 874                 kref_get(&info->refcount);
 875                 spin_unlock_bh(&bat_priv->vis_hash_lock);
 876
 877                 send_vis_packet(bat_priv, info);
 878
 879                 spin_lock_bh(&bat_priv->vis_hash_lock);
 880                 send_list_del(info);
 881                 kref_put(&info->refcount, free_info);
 882         }
 883         spin_unlock_bh(&bat_priv->vis_hash_lock);
 884         start_vis_timer(bat_priv);
 885 }
 886
 887 /* init the vis server. this may only be called when if_list is already
 888  * initialized (e.g. bat0 is initialized, interfaces have been added) */
 889 int vis_init(struct bat_priv *bat_priv)
 890 {
 891         struct vis_packet *packet;
 892         int hash_added;
 893
 894         if (bat_priv->vis_hash)
 895                 return 1;
 896
 897         spin_lock_bh(&bat_priv->vis_hash_lock);
 898
 899         bat_priv->vis_hash = hash_new(256);
 900         if (!bat_priv->vis_hash) {
 901                 pr_err("Can't initialize vis_hash\n");
 902                 goto err;
 903         }
 904
 905         bat_priv->my_vis_info = kmalloc(MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
 906         if (!bat_priv->my_vis_info) {
 907                 pr_err("Can't initialize vis packet\n");
 908                 goto err;
 909         }
 910
 911         bat_priv->my_vis_info->skb_packet = dev_alloc_skb(
 912                                                 sizeof(struct vis_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(
 920                                         bat_priv->my_vis_info->skb_packet,
 921                                         sizeof(struct vis_packet));
 922
 923         /* prefill the vis info */
 924         bat_priv->my_vis_info->first_seen = jiffies -
 925                                                 msecs_to_jiffies(VIS_INTERVAL);
 926         INIT_LIST_HEAD(&bat_priv->my_vis_info->recv_list);
 927         INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 928         kref_init(&bat_priv->my_vis_info->refcount);
 929         bat_priv->my_vis_info->bat_priv = bat_priv;
 930         packet->version = COMPAT_VERSION;
 931         packet->packet_type = BAT_VIS;
 932         packet->ttl = TTL;
 933         packet->seqno = 0;
 934         packet->entries = 0;
 935
 936         INIT_LIST_HEAD(&bat_priv->vis_send_list);
 937
 938         hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
 939                               bat_priv->my_vis_info,
 940                               &bat_priv->my_vis_info->hash_entry);
 941         if (hash_added < 0) {
 942                 pr_err("Can't add own vis packet into hash\n");
 943                 /* not in hash, need to remove it manually. */
 944                 kref_put(&bat_priv->my_vis_info->refcount, free_info);
 945                 goto err;
 946         }
 947
 948         spin_unlock_bh(&bat_priv->vis_hash_lock);
 949         start_vis_timer(bat_priv);
 950         return 1;
 951
 952 free_info:
 953         kfree(bat_priv->my_vis_info);
 954         bat_priv->my_vis_info = NULL;
 955 err:
 956         spin_unlock_bh(&bat_priv->vis_hash_lock);
 957         vis_quit(bat_priv);
 958         return 0;
 959 }
 960
 961 /* Decrease the reference count on a hash item info */
 962 static void free_info_ref(struct hlist_node *node, void *arg)
 963 {
 964         struct vis_info *info;
 965
 966         info = container_of(node, struct vis_info, hash_entry);
 967         send_list_del(info);
 968         kref_put(&info->refcount, free_info);
 969 }
 970
 971 /* shutdown vis-server */
 972 void vis_quit(struct bat_priv *bat_priv)
 973 {
 974         if (!bat_priv->vis_hash)
 975                 return;
 976
 977         cancel_delayed_work_sync(&bat_priv->vis_work);
 978
 979         spin_lock_bh(&bat_priv->vis_hash_lock);
 980         /* properly remove, kill timers ... */
 981         hash_delete(bat_priv->vis_hash, free_info_ref, NULL);
 982         bat_priv->vis_hash = NULL;
 983         bat_priv->my_vis_info = NULL;
 984         spin_unlock_bh(&bat_priv->vis_hash_lock);
 985 }
 986
 987 /* schedule packets for (re)transmission */
 988 static void start_vis_timer(struct bat_priv *bat_priv)
 989 {
 990         INIT_DELAYED_WORK(&bat_priv->vis_work, send_vis_packets);
 991         queue_delayed_work(bat_event_workqueue, &bat_priv->vis_work,
 992                            msecs_to_jiffies(VIS_INTERVAL));
 993 }