net/batman-adv/translation-table.c

   1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich, Antonio Quartulli
   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 "translation-table.h"
  22 #include "soft-interface.h"
  23 #include "hard-interface.h"
  24 #include "send.h"
  25 #include "hash.h"
  26 #include "originator.h"
  27 #include "routing.h"
  28 #include "bridge_loop_avoidance.h"
  29
  30 #include <linux/crc16.h>
  31
  32 static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
  33                                  struct batadv_orig_node *orig_node);
  34 static void batadv_tt_purge(struct work_struct *work);
  35 static void
  36 batadv_tt_global_del_orig_list(struct batadv_tt_global_entry *tt_global_entry);
  37 static void batadv_tt_global_del(struct batadv_priv *bat_priv,
  38                                  struct batadv_orig_node *orig_node,
  39                                  const unsigned char *addr,
  40                                  const char *message, bool roaming);
  41
  42 /* returns 1 if they are the same mac addr */
  43 static int batadv_compare_tt(const struct hlist_node *node, const void *data2)
  44 {
  45         const void *data1 = container_of(node, struct batadv_tt_common_entry,
  46                                          hash_entry);
  47
  48         return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
  49 }
  50
  51 static void batadv_tt_start_timer(struct batadv_priv *bat_priv)
  52 {
  53         INIT_DELAYED_WORK(&bat_priv->tt.work, batadv_tt_purge);
  54         queue_delayed_work(batadv_event_workqueue, &bat_priv->tt.work,
  55                            msecs_to_jiffies(5000));
  56 }
  57
  58 static struct batadv_tt_common_entry *
  59 batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
  60 {
  61         struct hlist_head *head;
  62         struct hlist_node *node;
  63         struct batadv_tt_common_entry *tt_common_entry;
  64         struct batadv_tt_common_entry *tt_common_entry_tmp = NULL;
  65         uint32_t index;
  66
  67         if (!hash)
  68                 return NULL;
  69
  70         index = batadv_choose_orig(data, hash->size);
  71         head = &hash->table[index];
  72
  73         rcu_read_lock();
  74         hlist_for_each_entry_rcu(tt_common_entry, node, head, hash_entry) {
  75                 if (!batadv_compare_eth(tt_common_entry, data))
  76                         continue;
  77
  78                 if (!atomic_inc_not_zero(&tt_common_entry->refcount))
  79                         continue;
  80
  81                 tt_common_entry_tmp = tt_common_entry;
  82                 break;
  83         }
  84         rcu_read_unlock();
  85
  86         return tt_common_entry_tmp;
  87 }
  88
  89 static struct batadv_tt_local_entry *
  90 batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const void *data)
  91 {
  92         struct batadv_tt_common_entry *tt_common_entry;
  93         struct batadv_tt_local_entry *tt_local_entry = NULL;
  94
  95         tt_common_entry = batadv_tt_hash_find(bat_priv->tt.local_hash, data);
  96         if (tt_common_entry)
  97                 tt_local_entry = container_of(tt_common_entry,
  98                                               struct batadv_tt_local_entry,
  99                                               common);
 100         return tt_local_entry;
 101 }
 102
 103 static struct batadv_tt_global_entry *
 104 batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const void *data)
 105 {
 106         struct batadv_tt_common_entry *tt_common_entry;
 107         struct batadv_tt_global_entry *tt_global_entry = NULL;
 108
 109         tt_common_entry = batadv_tt_hash_find(bat_priv->tt.global_hash, data);
 110         if (tt_common_entry)
 111                 tt_global_entry = container_of(tt_common_entry,
 112                                                struct batadv_tt_global_entry,
 113                                                common);
 114         return tt_global_entry;
 115
 116 }
 117
 118 static void
 119 batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry)
 120 {
 121         if (atomic_dec_and_test(&tt_local_entry->common.refcount))
 122                 kfree_rcu(tt_local_entry, common.rcu);
 123 }
 124
 125 static void batadv_tt_global_entry_free_rcu(struct rcu_head *rcu)
 126 {
 127         struct batadv_tt_common_entry *tt_common_entry;
 128         struct batadv_tt_global_entry *tt_global_entry;
 129
 130         tt_common_entry = container_of(rcu, struct batadv_tt_common_entry, rcu);
 131         tt_global_entry = container_of(tt_common_entry,
 132                                        struct batadv_tt_global_entry, common);
 133
 134         kfree(tt_global_entry);
 135 }
 136
 137 static void
 138 batadv_tt_global_entry_free_ref(struct batadv_tt_global_entry *tt_global_entry)
 139 {
 140         if (atomic_dec_and_test(&tt_global_entry->common.refcount)) {
 141                 batadv_tt_global_del_orig_list(tt_global_entry);
 142                 call_rcu(&tt_global_entry->common.rcu,
 143                          batadv_tt_global_entry_free_rcu);
 144         }
 145 }
 146
 147 static void batadv_tt_orig_list_entry_free_rcu(struct rcu_head *rcu)
 148 {
 149         struct batadv_tt_orig_list_entry *orig_entry;
 150
 151         orig_entry = container_of(rcu, struct batadv_tt_orig_list_entry, rcu);
 152         batadv_orig_node_free_ref(orig_entry->orig_node);
 153         kfree(orig_entry);
 154 }
 155
 156 static void
 157 batadv_tt_orig_list_entry_free_ref(struct batadv_tt_orig_list_entry *orig_entry)
 158 {
 159         if (!atomic_dec_and_test(&orig_entry->refcount))
 160                 return;
 161         /* to avoid race conditions, immediately decrease the tt counter */
 162         atomic_dec(&orig_entry->orig_node->tt_size);
 163         call_rcu(&orig_entry->rcu, batadv_tt_orig_list_entry_free_rcu);
 164 }
 165
 166 static void batadv_tt_local_event(struct batadv_priv *bat_priv,
 167                                   const uint8_t *addr, uint8_t flags)
 168 {
 169         struct batadv_tt_change_node *tt_change_node, *entry, *safe;
 170         bool event_removed = false;
 171         bool del_op_requested, del_op_entry;
 172
 173         tt_change_node = kmalloc(sizeof(*tt_change_node), GFP_ATOMIC);
 174
 175         if (!tt_change_node)
 176                 return;
 177
 178         tt_change_node->change.flags = flags;
 179         memcpy(tt_change_node->change.addr, addr, ETH_ALEN);
 180
 181         del_op_requested = flags & BATADV_TT_CLIENT_DEL;
 182
 183         /* check for ADD+DEL or DEL+ADD events */
 184         spin_lock_bh(&bat_priv->tt.changes_list_lock);
 185         list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
 186                                  list) {
 187                 if (!batadv_compare_eth(entry->change.addr, addr))
 188                         continue;
 189
 190                 /* DEL+ADD in the same orig interval have no effect and can be
 191                  * removed to avoid silly behaviour on the receiver side. The
 192                  * other way around (ADD+DEL) can happen in case of roaming of
 193                  * a client still in the NEW state. Roaming of NEW clients is
 194                  * now possible due to automatically recognition of "temporary"
 195                  * clients
 196                  */
 197                 del_op_entry = entry->change.flags & BATADV_TT_CLIENT_DEL;
 198                 if (!del_op_requested && del_op_entry)
 199                         goto del;
 200                 if (del_op_requested && !del_op_entry)
 201                         goto del;
 202                 continue;
 203 del:
 204                 list_del(&entry->list);
 205                 kfree(entry);
 206                 kfree(tt_change_node);
 207                 event_removed = true;
 208                 goto unlock;
 209         }
 210
 211         /* track the change in the OGMinterval list */
 212         list_add_tail(&tt_change_node->list, &bat_priv->tt.changes_list);
 213
 214 unlock:
 215         spin_unlock_bh(&bat_priv->tt.changes_list_lock);
 216
 217         if (event_removed)
 218                 atomic_dec(&bat_priv->tt.local_changes);
 219         else
 220                 atomic_inc(&bat_priv->tt.local_changes);
 221 }
 222
 223 int batadv_tt_len(int changes_num)
 224 {
 225         return changes_num * sizeof(struct batadv_tt_change);
 226 }
 227
 228 static int batadv_tt_local_init(struct batadv_priv *bat_priv)
 229 {
 230         if (bat_priv->tt.local_hash)
 231                 return 0;
 232
 233         bat_priv->tt.local_hash = batadv_hash_new(1024);
 234
 235         if (!bat_priv->tt.local_hash)
 236                 return -ENOMEM;
 237
 238         return 0;
 239 }
 240
 241 static void batadv_tt_global_free(struct batadv_priv *bat_priv,
 242                                   struct batadv_tt_global_entry *tt_global,
 243                                   const char *message)
 244 {
 245         batadv_dbg(BATADV_DBG_TT, bat_priv,
 246                    "Deleting global tt entry %pM: %s\n",
 247                    tt_global->common.addr, message);
 248
 249         batadv_hash_remove(bat_priv->tt.global_hash, batadv_compare_tt,
 250                            batadv_choose_orig, tt_global->common.addr);
 251         batadv_tt_global_entry_free_ref(tt_global);
 252
 253 }
 254
 255 void batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
 256                          int ifindex)
 257 {
 258         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 259         struct batadv_tt_local_entry *tt_local;
 260         struct batadv_tt_global_entry *tt_global;
 261         struct hlist_head *head;
 262         struct hlist_node *node;
 263         struct batadv_tt_orig_list_entry *orig_entry;
 264         int hash_added;
 265         bool roamed_back = false;
 266
 267         tt_local = batadv_tt_local_hash_find(bat_priv, addr);
 268         tt_global = batadv_tt_global_hash_find(bat_priv, addr);
 269
 270         if (tt_local) {
 271                 tt_local->last_seen = jiffies;
 272                 if (tt_local->common.flags & BATADV_TT_CLIENT_PENDING) {
 273                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 274                                    "Re-adding pending client %pM\n", addr);
 275                         /* whatever the reason why the PENDING flag was set,
 276                          * this is a client which was enqueued to be removed in
 277                          * this orig_interval. Since it popped up again, the
 278                          * flag can be reset like it was never enqueued
 279                          */
 280                         tt_local->common.flags &= ~BATADV_TT_CLIENT_PENDING;
 281                         goto add_event;
 282                 }
 283
 284                 if (tt_local->common.flags & BATADV_TT_CLIENT_ROAM) {
 285                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 286                                    "Roaming client %pM came back to its original location\n",
 287                                    addr);
 288                         /* the ROAM flag is set because this client roamed away
 289                          * and the node got a roaming_advertisement message. Now
 290                          * that the client popped up again at its original
 291                          * location such flag can be unset
 292                          */
 293                         tt_local->common.flags &= ~BATADV_TT_CLIENT_ROAM;
 294                         roamed_back = true;
 295                 }
 296                 goto check_roaming;
 297         }
 298
 299         tt_local = kmalloc(sizeof(*tt_local), GFP_ATOMIC);
 300         if (!tt_local)
 301                 goto out;
 302
 303         batadv_dbg(BATADV_DBG_TT, bat_priv,
 304                    "Creating new local tt entry: %pM (ttvn: %d)\n", addr,
 305                    (uint8_t)atomic_read(&bat_priv->tt.vn));
 306
 307         memcpy(tt_local->common.addr, addr, ETH_ALEN);
 308         tt_local->common.flags = BATADV_NO_FLAGS;
 309         if (batadv_is_wifi_iface(ifindex))
 310                 tt_local->common.flags |= BATADV_TT_CLIENT_WIFI;
 311         atomic_set(&tt_local->common.refcount, 2);
 312         tt_local->last_seen = jiffies;
 313         tt_local->common.added_at = tt_local->last_seen;
 314
 315         /* the batman interface mac address should never be purged */
 316         if (batadv_compare_eth(addr, soft_iface->dev_addr))
 317                 tt_local->common.flags |= BATADV_TT_CLIENT_NOPURGE;
 318
 319         /* The local entry has to be marked as NEW to avoid to send it in
 320          * a full table response going out before the next ttvn increment
 321          * (consistency check)
 322          */
 323         tt_local->common.flags |= BATADV_TT_CLIENT_NEW;
 324
 325         hash_added = batadv_hash_add(bat_priv->tt.local_hash, batadv_compare_tt,
 326                                      batadv_choose_orig, &tt_local->common,
 327                                      &tt_local->common.hash_entry);
 328
 329         if (unlikely(hash_added != 0)) {
 330                 /* remove the reference for the hash */
 331                 batadv_tt_local_entry_free_ref(tt_local);
 332                 goto out;
 333         }
 334
 335 add_event:
 336         batadv_tt_local_event(bat_priv, addr, tt_local->common.flags);
 337
 338 check_roaming:
 339         /* Check whether it is a roaming, but don't do anything if the roaming
 340          * process has already been handled
 341          */
 342         if (tt_global && !(tt_global->common.flags & BATADV_TT_CLIENT_ROAM)) {
 343                 /* These node are probably going to update their tt table */
 344                 head = &tt_global->orig_list;
 345                 rcu_read_lock();
 346                 hlist_for_each_entry_rcu(orig_entry, node, head, list) {
 347                         batadv_send_roam_adv(bat_priv, tt_global->common.addr,
 348                                              orig_entry->orig_node);
 349                 }
 350                 rcu_read_unlock();
 351                 if (roamed_back) {
 352                         batadv_tt_global_free(bat_priv, tt_global,
 353                                               "Roaming canceled");
 354                         tt_global = NULL;
 355                 } else {
 356                         /* The global entry has to be marked as ROAMING and
 357                          * has to be kept for consistency purpose
 358                          */
 359                         tt_global->common.flags |= BATADV_TT_CLIENT_ROAM;
 360                         tt_global->roam_at = jiffies;
 361                 }
 362         }
 363
 364 out:
 365         if (tt_local)
 366                 batadv_tt_local_entry_free_ref(tt_local);
 367         if (tt_global)
 368                 batadv_tt_global_entry_free_ref(tt_global);
 369 }
 370
 371 static void batadv_tt_realloc_packet_buff(unsigned char **packet_buff,
 372                                           int *packet_buff_len,
 373                                           int min_packet_len,
 374                                           int new_packet_len)
 375 {
 376         unsigned char *new_buff;
 377
 378         new_buff = kmalloc(new_packet_len, GFP_ATOMIC);
 379
 380         /* keep old buffer if kmalloc should fail */
 381         if (new_buff) {
 382                 memcpy(new_buff, *packet_buff, min_packet_len);
 383                 kfree(*packet_buff);
 384                 *packet_buff = new_buff;
 385                 *packet_buff_len = new_packet_len;
 386         }
 387 }
 388
 389 static void batadv_tt_prepare_packet_buff(struct batadv_priv *bat_priv,
 390                                           unsigned char **packet_buff,
 391                                           int *packet_buff_len,
 392                                           int min_packet_len)
 393 {
 394         struct batadv_hard_iface *primary_if;
 395         int req_len;
 396
 397         primary_if = batadv_primary_if_get_selected(bat_priv);
 398
 399         req_len = min_packet_len;
 400         req_len += batadv_tt_len(atomic_read(&bat_priv->tt.local_changes));
 401
 402         /* if we have too many changes for one packet don't send any
 403          * and wait for the tt table request which will be fragmented
 404          */
 405         if ((!primary_if) || (req_len > primary_if->soft_iface->mtu))
 406                 req_len = min_packet_len;
 407
 408         batadv_tt_realloc_packet_buff(packet_buff, packet_buff_len,
 409                                       min_packet_len, req_len);
 410
 411         if (primary_if)
 412                 batadv_hardif_free_ref(primary_if);
 413 }
 414
 415 static int batadv_tt_changes_fill_buff(struct batadv_priv *bat_priv,
 416                                        unsigned char **packet_buff,
 417                                        int *packet_buff_len,
 418                                        int min_packet_len)
 419 {
 420         struct batadv_tt_change_node *entry, *safe;
 421         int count = 0, tot_changes = 0, new_len;
 422         unsigned char *tt_buff;
 423
 424         batadv_tt_prepare_packet_buff(bat_priv, packet_buff,
 425                                       packet_buff_len, min_packet_len);
 426
 427         new_len = *packet_buff_len - min_packet_len;
 428         tt_buff = *packet_buff + min_packet_len;
 429
 430         if (new_len > 0)
 431                 tot_changes = new_len / batadv_tt_len(1);
 432
 433         spin_lock_bh(&bat_priv->tt.changes_list_lock);
 434         atomic_set(&bat_priv->tt.local_changes, 0);
 435
 436         list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
 437                                  list) {
 438                 if (count < tot_changes) {
 439                         memcpy(tt_buff + batadv_tt_len(count),
 440                                &entry->change, sizeof(struct batadv_tt_change));
 441                         count++;
 442                 }
 443                 list_del(&entry->list);
 444                 kfree(entry);
 445         }
 446         spin_unlock_bh(&bat_priv->tt.changes_list_lock);
 447
 448         /* Keep the buffer for possible tt_request */
 449         spin_lock_bh(&bat_priv->tt.last_changeset_lock);
 450         kfree(bat_priv->tt.last_changeset);
 451         bat_priv->tt.last_changeset_len = 0;
 452         bat_priv->tt.last_changeset = NULL;
 453         /* check whether this new OGM has no changes due to size problems */
 454         if (new_len > 0) {
 455                 /* if kmalloc() fails we will reply with the full table
 456                  * instead of providing the diff
 457                  */
 458                 bat_priv->tt.last_changeset = kmalloc(new_len, GFP_ATOMIC);
 459                 if (bat_priv->tt.last_changeset) {
 460                         memcpy(bat_priv->tt.last_changeset, tt_buff, new_len);
 461                         bat_priv->tt.last_changeset_len = new_len;
 462                 }
 463         }
 464         spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
 465
 466         return count;
 467 }
 468
 469 int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset)
 470 {
 471         struct net_device *net_dev = (struct net_device *)seq->private;
 472         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 473         struct batadv_hashtable *hash = bat_priv->tt.local_hash;
 474         struct batadv_tt_common_entry *tt_common_entry;
 475         struct batadv_hard_iface *primary_if;
 476         struct hlist_node *node;
 477         struct hlist_head *head;
 478         uint32_t i;
 479
 480         primary_if = batadv_seq_print_text_primary_if_get(seq);
 481         if (!primary_if)
 482                 goto out;
 483
 484         seq_printf(seq,
 485                    "Locally retrieved addresses (from %s) announced via TT (TTVN: %u):\n",
 486                    net_dev->name, (uint8_t)atomic_read(&bat_priv->tt.vn));
 487
 488         for (i = 0; i < hash->size; i++) {
 489                 head = &hash->table[i];
 490
 491                 rcu_read_lock();
 492                 hlist_for_each_entry_rcu(tt_common_entry, node,
 493                                          head, hash_entry) {
 494                         seq_printf(seq, " * %pM [%c%c%c%c%c]\n",
 495                                    tt_common_entry->addr,
 496                                    (tt_common_entry->flags &
 497                                     BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
 498                                    (tt_common_entry->flags &
 499                                     BATADV_TT_CLIENT_NOPURGE ? 'P' : '.'),
 500                                    (tt_common_entry->flags &
 501                                     BATADV_TT_CLIENT_NEW ? 'N' : '.'),
 502                                    (tt_common_entry->flags &
 503                                     BATADV_TT_CLIENT_PENDING ? 'X' : '.'),
 504                                    (tt_common_entry->flags &
 505                                     BATADV_TT_CLIENT_WIFI ? 'W' : '.'));
 506                 }
 507                 rcu_read_unlock();
 508         }
 509 out:
 510         if (primary_if)
 511                 batadv_hardif_free_ref(primary_if);
 512         return 0;
 513 }
 514
 515 static void
 516 batadv_tt_local_set_pending(struct batadv_priv *bat_priv,
 517                             struct batadv_tt_local_entry *tt_local_entry,
 518                             uint16_t flags, const char *message)
 519 {
 520         batadv_tt_local_event(bat_priv, tt_local_entry->common.addr,
 521                               tt_local_entry->common.flags | flags);
 522
 523         /* The local client has to be marked as "pending to be removed" but has
 524          * to be kept in the table in order to send it in a full table
 525          * response issued before the net ttvn increment (consistency check)
 526          */
 527         tt_local_entry->common.flags |= BATADV_TT_CLIENT_PENDING;
 528
 529         batadv_dbg(BATADV_DBG_TT, bat_priv,
 530                    "Local tt entry (%pM) pending to be removed: %s\n",
 531                    tt_local_entry->common.addr, message);
 532 }
 533
 534 /**
 535  * batadv_tt_local_remove - logically remove an entry from the local table
 536  * @bat_priv: the bat priv with all the soft interface information
 537  * @addr: the MAC address of the client to remove
 538  * @message: message to append to the log on deletion
 539  * @roaming: true if the deletion is due to a roaming event
 540  *
 541  * Returns the flags assigned to the local entry before being deleted
 542  */
 543 uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
 544                                 const uint8_t *addr, const char *message,
 545                                 bool roaming)
 546 {
 547         struct batadv_tt_local_entry *tt_local_entry;
 548         uint16_t flags, curr_flags = BATADV_NO_FLAGS;
 549
 550         tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
 551         if (!tt_local_entry)
 552                 goto out;
 553
 554         curr_flags = tt_local_entry->common.flags;
 555
 556         flags = BATADV_TT_CLIENT_DEL;
 557         /* if this global entry addition is due to a roaming, the node has to
 558          * mark the local entry as "roamed" in order to correctly reroute
 559          * packets later
 560          */
 561         if (roaming) {
 562                 flags |= BATADV_TT_CLIENT_ROAM;
 563                 /* mark the local client as ROAMed */
 564                 tt_local_entry->common.flags |= BATADV_TT_CLIENT_ROAM;
 565         }
 566
 567         if (!(tt_local_entry->common.flags & BATADV_TT_CLIENT_NEW)) {
 568                 batadv_tt_local_set_pending(bat_priv, tt_local_entry, flags,
 569                                             message);
 570                 goto out;
 571         }
 572         /* if this client has been added right now, it is possible to
 573          * immediately purge it
 574          */
 575         batadv_tt_local_event(bat_priv, tt_local_entry->common.addr,
 576                               curr_flags | BATADV_TT_CLIENT_DEL);
 577         hlist_del_rcu(&tt_local_entry->common.hash_entry);
 578         batadv_tt_local_entry_free_ref(tt_local_entry);
 579
 580 out:
 581         if (tt_local_entry)
 582                 batadv_tt_local_entry_free_ref(tt_local_entry);
 583
 584         return curr_flags;
 585 }
 586
 587 static void batadv_tt_local_purge_list(struct batadv_priv *bat_priv,
 588                                        struct hlist_head *head)
 589 {
 590         struct batadv_tt_local_entry *tt_local_entry;
 591         struct batadv_tt_common_entry *tt_common_entry;
 592         struct hlist_node *node, *node_tmp;
 593
 594         hlist_for_each_entry_safe(tt_common_entry, node, node_tmp, head,
 595                                   hash_entry) {
 596                 tt_local_entry = container_of(tt_common_entry,
 597                                               struct batadv_tt_local_entry,
 598                                               common);
 599                 if (tt_local_entry->common.flags & BATADV_TT_CLIENT_NOPURGE)
 600                         continue;
 601
 602                 /* entry already marked for deletion */
 603                 if (tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING)
 604                         continue;
 605
 606                 if (!batadv_has_timed_out(tt_local_entry->last_seen,
 607                                           BATADV_TT_LOCAL_TIMEOUT))
 608                         continue;
 609
 610                 batadv_tt_local_set_pending(bat_priv, tt_local_entry,
 611                                             BATADV_TT_CLIENT_DEL, "timed out");
 612         }
 613 }
 614
 615 static void batadv_tt_local_purge(struct batadv_priv *bat_priv)
 616 {
 617         struct batadv_hashtable *hash = bat_priv->tt.local_hash;
 618         struct hlist_head *head;
 619         spinlock_t *list_lock; /* protects write access to the hash lists */
 620         uint32_t i;
 621
 622         for (i = 0; i < hash->size; i++) {
 623                 head = &hash->table[i];
 624                 list_lock = &hash->list_locks[i];
 625
 626                 spin_lock_bh(list_lock);
 627                 batadv_tt_local_purge_list(bat_priv, head);
 628                 spin_unlock_bh(list_lock);
 629         }
 630
 631 }
 632
 633 static void batadv_tt_local_table_free(struct batadv_priv *bat_priv)
 634 {
 635         struct batadv_hashtable *hash;
 636         spinlock_t *list_lock; /* protects write access to the hash lists */
 637         struct batadv_tt_common_entry *tt_common_entry;
 638         struct batadv_tt_local_entry *tt_local;
 639         struct hlist_node *node, *node_tmp;
 640         struct hlist_head *head;
 641         uint32_t i;
 642
 643         if (!bat_priv->tt.local_hash)
 644                 return;
 645
 646         hash = bat_priv->tt.local_hash;
 647
 648         for (i = 0; i < hash->size; i++) {
 649                 head = &hash->table[i];
 650                 list_lock = &hash->list_locks[i];
 651
 652                 spin_lock_bh(list_lock);
 653                 hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,
 654                                           head, hash_entry) {
 655                         hlist_del_rcu(node);
 656                         tt_local = container_of(tt_common_entry,
 657                                                 struct batadv_tt_local_entry,
 658                                                 common);
 659                         batadv_tt_local_entry_free_ref(tt_local);
 660                 }
 661                 spin_unlock_bh(list_lock);
 662         }
 663
 664         batadv_hash_destroy(hash);
 665
 666         bat_priv->tt.local_hash = NULL;
 667 }
 668
 669 static int batadv_tt_global_init(struct batadv_priv *bat_priv)
 670 {
 671         if (bat_priv->tt.global_hash)
 672                 return 0;
 673
 674         bat_priv->tt.global_hash = batadv_hash_new(1024);
 675
 676         if (!bat_priv->tt.global_hash)
 677                 return -ENOMEM;
 678
 679         return 0;
 680 }
 681
 682 static void batadv_tt_changes_list_free(struct batadv_priv *bat_priv)
 683 {
 684         struct batadv_tt_change_node *entry, *safe;
 685
 686         spin_lock_bh(&bat_priv->tt.changes_list_lock);
 687
 688         list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
 689                                  list) {
 690                 list_del(&entry->list);
 691                 kfree(entry);
 692         }
 693
 694         atomic_set(&bat_priv->tt.local_changes, 0);
 695         spin_unlock_bh(&bat_priv->tt.changes_list_lock);
 696 }
 697
 698 /* retrieves the orig_tt_list_entry belonging to orig_node from the
 699  * batadv_tt_global_entry list
 700  *
 701  * returns it with an increased refcounter, NULL if not found
 702  */
 703 static struct batadv_tt_orig_list_entry *
 704 batadv_tt_global_orig_entry_find(const struct batadv_tt_global_entry *entry,
 705                                  const struct batadv_orig_node *orig_node)
 706 {
 707         struct batadv_tt_orig_list_entry *tmp_orig_entry, *orig_entry = NULL;
 708         const struct hlist_head *head;
 709         struct hlist_node *node;
 710
 711         rcu_read_lock();
 712         head = &entry->orig_list;
 713         hlist_for_each_entry_rcu(tmp_orig_entry, node, head, list) {
 714                 if (tmp_orig_entry->orig_node != orig_node)
 715                         continue;
 716                 if (!atomic_inc_not_zero(&tmp_orig_entry->refcount))
 717                         continue;
 718
 719                 orig_entry = tmp_orig_entry;
 720                 break;
 721         }
 722         rcu_read_unlock();
 723
 724         return orig_entry;
 725 }
 726
 727 /* find out if an orig_node is already in the list of a tt_global_entry.
 728  * returns true if found, false otherwise
 729  */
 730 static bool
 731 batadv_tt_global_entry_has_orig(const struct batadv_tt_global_entry *entry,
 732                                 const struct batadv_orig_node *orig_node)
 733 {
 734         struct batadv_tt_orig_list_entry *orig_entry;
 735         bool found = false;
 736
 737         orig_entry = batadv_tt_global_orig_entry_find(entry, orig_node);
 738         if (orig_entry) {
 739                 found = true;
 740                 batadv_tt_orig_list_entry_free_ref(orig_entry);
 741         }
 742
 743         return found;
 744 }
 745
 746 static void
 747 batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
 748                                 struct batadv_orig_node *orig_node, int ttvn)
 749 {
 750         struct batadv_tt_orig_list_entry *orig_entry;
 751
 752         orig_entry = batadv_tt_global_orig_entry_find(tt_global, orig_node);
 753         if (orig_entry) {
 754                 /* refresh the ttvn: the current value could be a bogus one that
 755                  * was added during a "temporary client detection"
 756                  */
 757                 orig_entry->ttvn = ttvn;
 758                 goto out;
 759         }
 760
 761         orig_entry = kzalloc(sizeof(*orig_entry), GFP_ATOMIC);
 762         if (!orig_entry)
 763                 goto out;
 764
 765         INIT_HLIST_NODE(&orig_entry->list);
 766         atomic_inc(&orig_node->refcount);
 767         atomic_inc(&orig_node->tt_size);
 768         orig_entry->orig_node = orig_node;
 769         orig_entry->ttvn = ttvn;
 770         atomic_set(&orig_entry->refcount, 2);
 771
 772         spin_lock_bh(&tt_global->list_lock);
 773         hlist_add_head_rcu(&orig_entry->list,
 774                            &tt_global->orig_list);
 775         spin_unlock_bh(&tt_global->list_lock);
 776 out:
 777         if (orig_entry)
 778                 batadv_tt_orig_list_entry_free_ref(orig_entry);
 779 }
 780
 781 /* caller must hold orig_node refcount */
 782 int batadv_tt_global_add(struct batadv_priv *bat_priv,
 783                          struct batadv_orig_node *orig_node,
 784                          const unsigned char *tt_addr, uint8_t flags,
 785                          uint8_t ttvn)
 786 {
 787         struct batadv_tt_global_entry *tt_global_entry;
 788         struct batadv_tt_local_entry *tt_local_entry;
 789         int ret = 0;
 790         int hash_added;
 791         struct batadv_tt_common_entry *common;
 792         uint16_t local_flags;
 793
 794         tt_global_entry = batadv_tt_global_hash_find(bat_priv, tt_addr);
 795         tt_local_entry = batadv_tt_local_hash_find(bat_priv, tt_addr);
 796
 797         /* if the node already has a local client for this entry, it has to wait
 798          * for a roaming advertisement instead of manually messing up the global
 799          * table
 800          */
 801         if ((flags & BATADV_TT_CLIENT_TEMP) && tt_local_entry &&
 802             !(tt_local_entry->common.flags & BATADV_TT_CLIENT_NEW))
 803                 goto out;
 804
 805         if (!tt_global_entry) {
 806                 tt_global_entry = kzalloc(sizeof(*tt_global_entry), GFP_ATOMIC);
 807                 if (!tt_global_entry)
 808                         goto out;
 809
 810                 common = &tt_global_entry->common;
 811                 memcpy(common->addr, tt_addr, ETH_ALEN);
 812
 813                 common->flags = flags;
 814                 tt_global_entry->roam_at = 0;
 815                 /* node must store current time in case of roaming. This is
 816                  * needed to purge this entry out on timeout (if nobody claims
 817                  * it)
 818                  */
 819                 if (flags & BATADV_TT_CLIENT_ROAM)
 820                         tt_global_entry->roam_at = jiffies;
 821                 atomic_set(&common->refcount, 2);
 822                 common->added_at = jiffies;
 823
 824                 INIT_HLIST_HEAD(&tt_global_entry->orig_list);
 825                 spin_lock_init(&tt_global_entry->list_lock);
 826
 827                 hash_added = batadv_hash_add(bat_priv->tt.global_hash,
 828                                              batadv_compare_tt,
 829                                              batadv_choose_orig, common,
 830                                              &common->hash_entry);
 831
 832                 if (unlikely(hash_added != 0)) {
 833                         /* remove the reference for the hash */
 834                         batadv_tt_global_entry_free_ref(tt_global_entry);
 835                         goto out_remove;
 836                 }
 837         } else {
 838                 common = &tt_global_entry->common;
 839                 /* If there is already a global entry, we can use this one for
 840                  * our processing.
 841                  * But if we are trying to add a temporary client then here are
 842                  * two options at this point:
 843                  * 1) the global client is not a temporary client: the global
 844                  *    client has to be left as it is, temporary information
 845                  *    should never override any already known client state
 846                  * 2) the global client is a temporary client: purge the
 847                  *    originator list and add the new one orig_entry
 848                  */
 849                 if (flags & BATADV_TT_CLIENT_TEMP) {
 850                         if (!(common->flags & BATADV_TT_CLIENT_TEMP))
 851                                 goto out;
 852                         if (batadv_tt_global_entry_has_orig(tt_global_entry,
 853                                                             orig_node))
 854                                 goto out_remove;
 855                         batadv_tt_global_del_orig_list(tt_global_entry);
 856                         goto add_orig_entry;
 857                 }
 858
 859                 /* if the client was temporary added before receiving the first
 860                  * OGM announcing it, we have to clear the TEMP flag
 861                  */
 862                 common->flags &= ~BATADV_TT_CLIENT_TEMP;
 863
 864                 /* the change can carry possible "attribute" flags like the
 865                  * TT_CLIENT_WIFI, therefore they have to be copied in the
 866                  * client entry
 867                  */
 868                 tt_global_entry->common.flags |= flags;
 869
 870                 /* If there is the BATADV_TT_CLIENT_ROAM flag set, there is only
 871                  * one originator left in the list and we previously received a
 872                  * delete + roaming change for this originator.
 873                  *
 874                  * We should first delete the old originator before adding the
 875                  * new one.
 876                  */
 877                 if (common->flags & BATADV_TT_CLIENT_ROAM) {
 878                         batadv_tt_global_del_orig_list(tt_global_entry);
 879                         common->flags &= ~BATADV_TT_CLIENT_ROAM;
 880                         tt_global_entry->roam_at = 0;
 881                 }
 882         }
 883 add_orig_entry:
 884         /* add the new orig_entry (if needed) or update it */
 885         batadv_tt_global_orig_entry_add(tt_global_entry, orig_node, ttvn);
 886
 887         batadv_dbg(BATADV_DBG_TT, bat_priv,
 888                    "Creating new global tt entry: %pM (via %pM)\n",
 889                    common->addr, orig_node->orig);
 890         ret = 1;
 891
 892 out_remove:
 893
 894         /* remove address from local hash if present */
 895         local_flags = batadv_tt_local_remove(bat_priv, tt_addr,
 896                                              "global tt received",
 897                                              !!(flags & BATADV_TT_CLIENT_ROAM));
 898         tt_global_entry->common.flags |= local_flags & BATADV_TT_CLIENT_WIFI;
 899
 900         if (!(flags & BATADV_TT_CLIENT_ROAM))
 901                 /* this is a normal global add. Therefore the client is not in a
 902                  * roaming state anymore.
 903                  */
 904                 tt_global_entry->common.flags &= ~BATADV_TT_CLIENT_ROAM;
 905
 906 out:
 907         if (tt_global_entry)
 908                 batadv_tt_global_entry_free_ref(tt_global_entry);
 909         if (tt_local_entry)
 910                 batadv_tt_local_entry_free_ref(tt_local_entry);
 911         return ret;
 912 }
 913
 914 /* batadv_transtable_best_orig - Get best originator list entry from tt entry
 915  * @tt_global_entry: global translation table entry to be analyzed
 916  *
 917  * This functon assumes the caller holds rcu_read_lock().
 918  * Returns best originator list entry or NULL on errors.
 919  */
 920 static struct batadv_tt_orig_list_entry *
 921 batadv_transtable_best_orig(struct batadv_tt_global_entry *tt_global_entry)
 922 {
 923         struct batadv_neigh_node *router = NULL;
 924         struct hlist_head *head;
 925         struct hlist_node *node;
 926         struct batadv_tt_orig_list_entry *orig_entry, *best_entry = NULL;
 927         int best_tq = 0;
 928
 929         head = &tt_global_entry->orig_list;
 930         hlist_for_each_entry_rcu(orig_entry, node, head, list) {
 931                 router = batadv_orig_node_get_router(orig_entry->orig_node);
 932                 if (!router)
 933                         continue;
 934
 935                 if (router->tq_avg > best_tq) {
 936                         best_entry = orig_entry;
 937                         best_tq = router->tq_avg;
 938                 }
 939
 940                 batadv_neigh_node_free_ref(router);
 941         }
 942
 943         return best_entry;
 944 }
 945
 946 /* batadv_tt_global_print_entry - print all orig nodes who announce the address
 947  * for this global entry
 948  * @tt_global_entry: global translation table entry to be printed
 949  * @seq: debugfs table seq_file struct
 950  *
 951  * This functon assumes the caller holds rcu_read_lock().
 952  */
 953 static void
 954 batadv_tt_global_print_entry(struct batadv_tt_global_entry *tt_global_entry,
 955                              struct seq_file *seq)
 956 {
 957         struct hlist_head *head;
 958         struct hlist_node *node;
 959         struct batadv_tt_orig_list_entry *orig_entry, *best_entry;
 960         struct batadv_tt_common_entry *tt_common_entry;
 961         uint16_t flags;
 962         uint8_t last_ttvn;
 963
 964         tt_common_entry = &tt_global_entry->common;
 965         flags = tt_common_entry->flags;
 966
 967         best_entry = batadv_transtable_best_orig(tt_global_entry);
 968         if (best_entry) {
 969                 last_ttvn = atomic_read(&best_entry->orig_node->last_ttvn);
 970                 seq_printf(seq, " %c %pM  (%3u) via %pM     (%3u)   [%c%c%c]\n",
 971                            '*', tt_global_entry->common.addr,
 972                            best_entry->ttvn, best_entry->orig_node->orig,
 973                            last_ttvn,
 974                            (flags & BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
 975                            (flags & BATADV_TT_CLIENT_WIFI ? 'W' : '.'),
 976                            (flags & BATADV_TT_CLIENT_TEMP ? 'T' : '.'));
 977         }
 978
 979         head = &tt_global_entry->orig_list;
 980
 981         hlist_for_each_entry_rcu(orig_entry, node, head, list) {
 982                 if (best_entry == orig_entry)
 983                         continue;
 984
 985                 last_ttvn = atomic_read(&orig_entry->orig_node->last_ttvn);
 986                 seq_printf(seq, " %c %pM  (%3u) via %pM     (%3u)   [%c%c%c]\n",
 987                            '+', tt_global_entry->common.addr,
 988                            orig_entry->ttvn, orig_entry->orig_node->orig,
 989                            last_ttvn,
 990                            (flags & BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
 991                            (flags & BATADV_TT_CLIENT_WIFI ? 'W' : '.'),
 992                            (flags & BATADV_TT_CLIENT_TEMP ? 'T' : '.'));
 993         }
 994 }
 995
 996 int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset)
 997 {
 998         struct net_device *net_dev = (struct net_device *)seq->private;
 999         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1000         struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1001         struct batadv_tt_common_entry *tt_common_entry;
1002         struct batadv_tt_global_entry *tt_global;
1003         struct batadv_hard_iface *primary_if;
1004         struct hlist_node *node;
1005         struct hlist_head *head;
1006         uint32_t i;
1007
1008         primary_if = batadv_seq_print_text_primary_if_get(seq);
1009         if (!primary_if)
1010                 goto out;
1011
1012         seq_printf(seq,
1013                    "Globally announced TT entries received via the mesh %s\n",
1014                    net_dev->name);
1015         seq_printf(seq, "       %-13s %s       %-15s %s %s\n",
1016                    "Client", "(TTVN)", "Originator", "(Curr TTVN)", "Flags");
1017
1018         for (i = 0; i < hash->size; i++) {
1019                 head = &hash->table[i];
1020
1021                 rcu_read_lock();
1022                 hlist_for_each_entry_rcu(tt_common_entry, node,
1023                                          head, hash_entry) {
1024                         tt_global = container_of(tt_common_entry,
1025                                                  struct batadv_tt_global_entry,
1026                                                  common);
1027                         batadv_tt_global_print_entry(tt_global, seq);
1028                 }
1029                 rcu_read_unlock();
1030         }
1031 out:
1032         if (primary_if)
1033                 batadv_hardif_free_ref(primary_if);
1034         return 0;
1035 }
1036
1037 /* deletes the orig list of a tt_global_entry */
1038 static void
1039 batadv_tt_global_del_orig_list(struct batadv_tt_global_entry *tt_global_entry)
1040 {
1041         struct hlist_head *head;
1042         struct hlist_node *node, *safe;
1043         struct batadv_tt_orig_list_entry *orig_entry;
1044
1045         spin_lock_bh(&tt_global_entry->list_lock);
1046         head = &tt_global_entry->orig_list;
1047         hlist_for_each_entry_safe(orig_entry, node, safe, head, list) {
1048                 hlist_del_rcu(node);
1049                 batadv_tt_orig_list_entry_free_ref(orig_entry);
1050         }
1051         spin_unlock_bh(&tt_global_entry->list_lock);
1052
1053 }
1054
1055 static void
1056 batadv_tt_global_del_orig_entry(struct batadv_priv *bat_priv,
1057                                 struct batadv_tt_global_entry *tt_global_entry,
1058                                 struct batadv_orig_node *orig_node,
1059                                 const char *message)
1060 {
1061         struct hlist_head *head;
1062         struct hlist_node *node, *safe;
1063         struct batadv_tt_orig_list_entry *orig_entry;
1064
1065         spin_lock_bh(&tt_global_entry->list_lock);
1066         head = &tt_global_entry->orig_list;
1067         hlist_for_each_entry_safe(orig_entry, node, safe, head, list) {
1068                 if (orig_entry->orig_node == orig_node) {
1069                         batadv_dbg(BATADV_DBG_TT, bat_priv,
1070                                    "Deleting %pM from global tt entry %pM: %s\n",
1071                                    orig_node->orig,
1072                                    tt_global_entry->common.addr, message);
1073                         hlist_del_rcu(node);
1074                         batadv_tt_orig_list_entry_free_ref(orig_entry);
1075                 }
1076         }
1077         spin_unlock_bh(&tt_global_entry->list_lock);
1078 }
1079
1080 /* If the client is to be deleted, we check if it is the last origantor entry
1081  * within tt_global entry. If yes, we set the BATADV_TT_CLIENT_ROAM flag and the
1082  * timer, otherwise we simply remove the originator scheduled for deletion.
1083  */
1084 static void
1085 batadv_tt_global_del_roaming(struct batadv_priv *bat_priv,
1086                              struct batadv_tt_global_entry *tt_global_entry,
1087                              struct batadv_orig_node *orig_node,
1088                              const char *message)
1089 {
1090         bool last_entry = true;
1091         struct hlist_head *head;
1092         struct hlist_node *node;
1093         struct batadv_tt_orig_list_entry *orig_entry;
1094
1095         /* no local entry exists, case 1:
1096          * Check if this is the last one or if other entries exist.
1097          */
1098
1099         rcu_read_lock();
1100         head = &tt_global_entry->orig_list;
1101         hlist_for_each_entry_rcu(orig_entry, node, head, list) {
1102                 if (orig_entry->orig_node != orig_node) {
1103                         last_entry = false;
1104                         break;
1105                 }
1106         }
1107         rcu_read_unlock();
1108
1109         if (last_entry) {
1110                 /* its the last one, mark for roaming. */
1111                 tt_global_entry->common.flags |= BATADV_TT_CLIENT_ROAM;
1112                 tt_global_entry->roam_at = jiffies;
1113         } else
1114                 /* there is another entry, we can simply delete this
1115                  * one and can still use the other one.
1116                  */
1117                 batadv_tt_global_del_orig_entry(bat_priv, tt_global_entry,
1118                                                 orig_node, message);
1119 }
1120
1121
1122
1123 static void batadv_tt_global_del(struct batadv_priv *bat_priv,
1124                                  struct batadv_orig_node *orig_node,
1125                                  const unsigned char *addr,
1126                                  const char *message, bool roaming)
1127 {
1128         struct batadv_tt_global_entry *tt_global_entry;
1129         struct batadv_tt_local_entry *local_entry = NULL;
1130
1131         tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
1132         if (!tt_global_entry)
1133                 goto out;
1134
1135         if (!roaming) {
1136                 batadv_tt_global_del_orig_entry(bat_priv, tt_global_entry,
1137                                                 orig_node, message);
1138
1139                 if (hlist_empty(&tt_global_entry->orig_list))
1140                         batadv_tt_global_free(bat_priv, tt_global_entry,
1141                                               message);
1142
1143                 goto out;
1144         }
1145
1146         /* if we are deleting a global entry due to a roam
1147          * event, there are two possibilities:
1148          * 1) the client roamed from node A to node B => if there
1149          *    is only one originator left for this client, we mark
1150          *    it with BATADV_TT_CLIENT_ROAM, we start a timer and we
1151          *    wait for node B to claim it. In case of timeout
1152          *    the entry is purged.
1153          *
1154          *    If there are other originators left, we directly delete
1155          *    the originator.
1156          * 2) the client roamed to us => we can directly delete
1157          *    the global entry, since it is useless now.
1158          */
1159         local_entry = batadv_tt_local_hash_find(bat_priv,
1160                                                 tt_global_entry->common.addr);
1161         if (local_entry) {
1162                 /* local entry exists, case 2: client roamed to us. */
1163                 batadv_tt_global_del_orig_list(tt_global_entry);
1164                 batadv_tt_global_free(bat_priv, tt_global_entry, message);
1165         } else
1166                 /* no local entry exists, case 1: check for roaming */
1167                 batadv_tt_global_del_roaming(bat_priv, tt_global_entry,
1168                                              orig_node, message);
1169
1170
1171 out:
1172         if (tt_global_entry)
1173                 batadv_tt_global_entry_free_ref(tt_global_entry);
1174         if (local_entry)
1175                 batadv_tt_local_entry_free_ref(local_entry);
1176 }
1177
1178 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
1179                                struct batadv_orig_node *orig_node,
1180                                const char *message)
1181 {
1182         struct batadv_tt_global_entry *tt_global;
1183         struct batadv_tt_common_entry *tt_common_entry;
1184         uint32_t i;
1185         struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1186         struct hlist_node *node, *safe;
1187         struct hlist_head *head;
1188         spinlock_t *list_lock; /* protects write access to the hash lists */
1189
1190         if (!hash)
1191                 return;
1192
1193         for (i = 0; i < hash->size; i++) {
1194                 head = &hash->table[i];
1195                 list_lock = &hash->list_locks[i];
1196
1197                 spin_lock_bh(list_lock);
1198                 hlist_for_each_entry_safe(tt_common_entry, node, safe,
1199                                           head, hash_entry) {
1200                         tt_global = container_of(tt_common_entry,
1201                                                  struct batadv_tt_global_entry,
1202                                                  common);
1203
1204                         batadv_tt_global_del_orig_entry(bat_priv, tt_global,
1205                                                         orig_node, message);
1206
1207                         if (hlist_empty(&tt_global->orig_list)) {
1208                                 batadv_dbg(BATADV_DBG_TT, bat_priv,
1209                                            "Deleting global tt entry %pM: %s\n",
1210                                            tt_global->common.addr, message);
1211                                 hlist_del_rcu(node);
1212                                 batadv_tt_global_entry_free_ref(tt_global);
1213                         }
1214                 }
1215                 spin_unlock_bh(list_lock);
1216         }
1217         orig_node->tt_initialised = false;
1218 }
1219
1220 static bool batadv_tt_global_to_purge(struct batadv_tt_global_entry *tt_global,
1221                                       char **msg)
1222 {
1223         bool purge = false;
1224         unsigned long roam_timeout = BATADV_TT_CLIENT_ROAM_TIMEOUT;
1225         unsigned long temp_timeout = BATADV_TT_CLIENT_TEMP_TIMEOUT;
1226
1227         if ((tt_global->common.flags & BATADV_TT_CLIENT_ROAM) &&
1228             batadv_has_timed_out(tt_global->roam_at, roam_timeout)) {
1229                 purge = true;
1230                 *msg = "Roaming timeout\n";
1231         }
1232
1233         if ((tt_global->common.flags & BATADV_TT_CLIENT_TEMP) &&
1234             batadv_has_timed_out(tt_global->common.added_at, temp_timeout)) {
1235                 purge = true;
1236                 *msg = "Temporary client timeout\n";
1237         }
1238
1239         return purge;
1240 }
1241
1242 static void batadv_tt_global_purge(struct batadv_priv *bat_priv)
1243 {
1244         struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1245         struct hlist_head *head;
1246         struct hlist_node *node, *node_tmp;
1247         spinlock_t *list_lock; /* protects write access to the hash lists */
1248         uint32_t i;
1249         char *msg = NULL;
1250         struct batadv_tt_common_entry *tt_common;
1251         struct batadv_tt_global_entry *tt_global;
1252
1253         for (i = 0; i < hash->size; i++) {
1254                 head = &hash->table[i];
1255                 list_lock = &hash->list_locks[i];
1256
1257                 spin_lock_bh(list_lock);
1258                 hlist_for_each_entry_safe(tt_common, node, node_tmp, head,
1259                                           hash_entry) {
1260                         tt_global = container_of(tt_common,
1261                                                  struct batadv_tt_global_entry,
1262                                                  common);
1263
1264                         if (!batadv_tt_global_to_purge(tt_global, &msg))
1265                                 continue;
1266
1267                         batadv_dbg(BATADV_DBG_TT, bat_priv,
1268                                    "Deleting global tt entry (%pM): %s\n",
1269                                    tt_global->common.addr, msg);
1270
1271                         hlist_del_rcu(node);
1272
1273                         batadv_tt_global_entry_free_ref(tt_global);
1274                 }
1275                 spin_unlock_bh(list_lock);
1276         }
1277 }
1278
1279 static void batadv_tt_global_table_free(struct batadv_priv *bat_priv)
1280 {
1281         struct batadv_hashtable *hash;
1282         spinlock_t *list_lock; /* protects write access to the hash lists */
1283         struct batadv_tt_common_entry *tt_common_entry;
1284         struct batadv_tt_global_entry *tt_global;
1285         struct hlist_node *node, *node_tmp;
1286         struct hlist_head *head;
1287         uint32_t i;
1288
1289         if (!bat_priv->tt.global_hash)
1290                 return;
1291
1292         hash = bat_priv->tt.global_hash;
1293
1294         for (i = 0; i < hash->size; i++) {
1295                 head = &hash->table[i];
1296                 list_lock = &hash->list_locks[i];
1297
1298                 spin_lock_bh(list_lock);
1299                 hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,
1300                                           head, hash_entry) {
1301                         hlist_del_rcu(node);
1302                         tt_global = container_of(tt_common_entry,
1303                                                  struct batadv_tt_global_entry,
1304                                                  common);
1305                         batadv_tt_global_entry_free_ref(tt_global);
1306                 }
1307                 spin_unlock_bh(list_lock);
1308         }
1309
1310         batadv_hash_destroy(hash);
1311
1312         bat_priv->tt.global_hash = NULL;
1313 }
1314
1315 static bool
1316 _batadv_is_ap_isolated(struct batadv_tt_local_entry *tt_local_entry,
1317                        struct batadv_tt_global_entry *tt_global_entry)
1318 {
1319         bool ret = false;
1320
1321         if (tt_local_entry->common.flags & BATADV_TT_CLIENT_WIFI &&
1322             tt_global_entry->common.flags & BATADV_TT_CLIENT_WIFI)
1323                 ret = true;
1324
1325         return ret;
1326 }
1327
1328 struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
1329                                                   const uint8_t *src,
1330                                                   const uint8_t *addr)
1331 {
1332         struct batadv_tt_local_entry *tt_local_entry = NULL;
1333         struct batadv_tt_global_entry *tt_global_entry = NULL;
1334         struct batadv_orig_node *orig_node = NULL;
1335         struct batadv_tt_orig_list_entry *best_entry;
1336
1337         if (src && atomic_read(&bat_priv->ap_isolation)) {
1338                 tt_local_entry = batadv_tt_local_hash_find(bat_priv, src);
1339                 if (!tt_local_entry ||
1340                     (tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING))
1341                         goto out;
1342         }
1343
1344         tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
1345         if (!tt_global_entry)
1346                 goto out;
1347
1348         /* check whether the clients should not communicate due to AP
1349          * isolation
1350          */
1351         if (tt_local_entry &&
1352             _batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
1353                 goto out;
1354
1355         rcu_read_lock();
1356         best_entry = batadv_transtable_best_orig(tt_global_entry);
1357         /* found anything? */
1358         if (best_entry)
1359                 orig_node = best_entry->orig_node;
1360         if (orig_node && !atomic_inc_not_zero(&orig_node->refcount))
1361                 orig_node = NULL;
1362         rcu_read_unlock();
1363
1364 out:
1365         if (tt_global_entry)
1366                 batadv_tt_global_entry_free_ref(tt_global_entry);
1367         if (tt_local_entry)
1368                 batadv_tt_local_entry_free_ref(tt_local_entry);
1369
1370         return orig_node;
1371 }
1372
1373 /* Calculates the checksum of the local table of a given orig_node */
1374 static uint16_t batadv_tt_global_crc(struct batadv_priv *bat_priv,
1375                                      struct batadv_orig_node *orig_node)
1376 {
1377         uint16_t total = 0, total_one;
1378         struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1379         struct batadv_tt_common_entry *tt_common;
1380         struct batadv_tt_global_entry *tt_global;
1381         struct hlist_node *node;
1382         struct hlist_head *head;
1383         uint32_t i;
1384         int j;
1385
1386         for (i = 0; i < hash->size; i++) {
1387                 head = &hash->table[i];
1388
1389                 rcu_read_lock();
1390                 hlist_for_each_entry_rcu(tt_common, node, head, hash_entry) {
1391                         tt_global = container_of(tt_common,
1392                                                  struct batadv_tt_global_entry,
1393                                                  common);
1394                         /* Roaming clients are in the global table for
1395                          * consistency only. They don't have to be
1396                          * taken into account while computing the
1397                          * global crc
1398                          */
1399                         if (tt_common->flags & BATADV_TT_CLIENT_ROAM)
1400                                 continue;
1401                         /* Temporary clients have not been announced yet, so
1402                          * they have to be skipped while computing the global
1403                          * crc
1404                          */
1405                         if (tt_common->flags & BATADV_TT_CLIENT_TEMP)
1406                                 continue;
1407
1408                         /* find out if this global entry is announced by this
1409                          * originator
1410                          */
1411                         if (!batadv_tt_global_entry_has_orig(tt_global,
1412                                                              orig_node))
1413                                 continue;
1414
1415                         total_one = 0;
1416                         for (j = 0; j < ETH_ALEN; j++)
1417                                 total_one = crc16_byte(total_one,
1418                                                        tt_common->addr[j]);
1419                         total ^= total_one;
1420                 }
1421                 rcu_read_unlock();
1422         }
1423
1424         return total;
1425 }
1426
1427 /* Calculates the checksum of the local table */
1428 static uint16_t batadv_tt_local_crc(struct batadv_priv *bat_priv)
1429 {
1430         uint16_t total = 0, total_one;
1431         struct batadv_hashtable *hash = bat_priv->tt.local_hash;
1432         struct batadv_tt_common_entry *tt_common;
1433         struct hlist_node *node;
1434         struct hlist_head *head;
1435         uint32_t i;
1436         int j;
1437
1438         for (i = 0; i < hash->size; i++) {
1439                 head = &hash->table[i];
1440
1441                 rcu_read_lock();
1442                 hlist_for_each_entry_rcu(tt_common, node, head, hash_entry) {
1443                         /* not yet committed clients have not to be taken into
1444                          * account while computing the CRC
1445                          */
1446                         if (tt_common->flags & BATADV_TT_CLIENT_NEW)
1447                                 continue;
1448                         total_one = 0;
1449                         for (j = 0; j < ETH_ALEN; j++)
1450                                 total_one = crc16_byte(total_one,
1451                                                        tt_common->addr[j]);
1452                         total ^= total_one;
1453                 }
1454                 rcu_read_unlock();
1455         }
1456
1457         return total;
1458 }
1459
1460 static void batadv_tt_req_list_free(struct batadv_priv *bat_priv)
1461 {
1462         struct batadv_tt_req_node *node, *safe;
1463
1464         spin_lock_bh(&bat_priv->tt.req_list_lock);
1465
1466         list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
1467                 list_del(&node->list);
1468                 kfree(node);
1469         }
1470
1471         spin_unlock_bh(&bat_priv->tt.req_list_lock);
1472 }
1473
1474 static void batadv_tt_save_orig_buffer(struct batadv_priv *bat_priv,
1475                                        struct batadv_orig_node *orig_node,
1476                                        const unsigned char *tt_buff,
1477                                        uint8_t tt_num_changes)
1478 {
1479         uint16_t tt_buff_len = batadv_tt_len(tt_num_changes);
1480
1481         /* Replace the old buffer only if I received something in the
1482          * last OGM (the OGM could carry no changes)
1483          */
1484         spin_lock_bh(&orig_node->tt_buff_lock);
1485         if (tt_buff_len > 0) {
1486                 kfree(orig_node->tt_buff);
1487                 orig_node->tt_buff_len = 0;
1488                 orig_node->tt_buff = kmalloc(tt_buff_len, GFP_ATOMIC);
1489                 if (orig_node->tt_buff) {
1490                         memcpy(orig_node->tt_buff, tt_buff, tt_buff_len);
1491                         orig_node->tt_buff_len = tt_buff_len;
1492                 }
1493         }
1494         spin_unlock_bh(&orig_node->tt_buff_lock);
1495 }
1496
1497 static void batadv_tt_req_purge(struct batadv_priv *bat_priv)
1498 {
1499         struct batadv_tt_req_node *node, *safe;
1500
1501         spin_lock_bh(&bat_priv->tt.req_list_lock);
1502         list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
1503                 if (batadv_has_timed_out(node->issued_at,
1504                                          BATADV_TT_REQUEST_TIMEOUT)) {
1505                         list_del(&node->list);
1506                         kfree(node);
1507                 }
1508         }
1509         spin_unlock_bh(&bat_priv->tt.req_list_lock);
1510 }
1511
1512 /* returns the pointer to the new tt_req_node struct if no request
1513  * has already been issued for this orig_node, NULL otherwise
1514  */
1515 static struct batadv_tt_req_node *
1516 batadv_new_tt_req_node(struct batadv_priv *bat_priv,
1517                        struct batadv_orig_node *orig_node)
1518 {
1519         struct batadv_tt_req_node *tt_req_node_tmp, *tt_req_node = NULL;
1520
1521         spin_lock_bh(&bat_priv->tt.req_list_lock);
1522         list_for_each_entry(tt_req_node_tmp, &bat_priv->tt.req_list, list) {
1523                 if (batadv_compare_eth(tt_req_node_tmp, orig_node) &&
1524                     !batadv_has_timed_out(tt_req_node_tmp->issued_at,
1525                                           BATADV_TT_REQUEST_TIMEOUT))
1526                         goto unlock;
1527         }
1528
1529         tt_req_node = kmalloc(sizeof(*tt_req_node), GFP_ATOMIC);
1530         if (!tt_req_node)
1531                 goto unlock;
1532
1533         memcpy(tt_req_node->addr, orig_node->orig, ETH_ALEN);
1534         tt_req_node->issued_at = jiffies;
1535
1536         list_add(&tt_req_node->list, &bat_priv->tt.req_list);
1537 unlock:
1538         spin_unlock_bh(&bat_priv->tt.req_list_lock);
1539         return tt_req_node;
1540 }
1541
1542 /* data_ptr is useless here, but has to be kept to respect the prototype */
1543 static int batadv_tt_local_valid_entry(const void *entry_ptr,
1544                                        const void *data_ptr)
1545 {
1546         const struct batadv_tt_common_entry *tt_common_entry = entry_ptr;
1547
1548         if (tt_common_entry->flags & BATADV_TT_CLIENT_NEW)
1549                 return 0;
1550         return 1;
1551 }
1552
1553 static int batadv_tt_global_valid(const void *entry_ptr,
1554                                   const void *data_ptr)
1555 {
1556         const struct batadv_tt_common_entry *tt_common_entry = entry_ptr;
1557         const struct batadv_tt_global_entry *tt_global_entry;
1558         const struct batadv_orig_node *orig_node = data_ptr;
1559
1560         if (tt_common_entry->flags & BATADV_TT_CLIENT_ROAM ||
1561             tt_common_entry->flags & BATADV_TT_CLIENT_TEMP)
1562                 return 0;
1563
1564         tt_global_entry = container_of(tt_common_entry,
1565                                        struct batadv_tt_global_entry,
1566                                        common);
1567
1568         return batadv_tt_global_entry_has_orig(tt_global_entry, orig_node);
1569 }
1570
1571 static struct sk_buff *
1572 batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
1573                               struct batadv_hashtable *hash,
1574                               struct batadv_hard_iface *primary_if,
1575                               int (*valid_cb)(const void *, const void *),
1576                               void *cb_data)
1577 {
1578         struct batadv_tt_common_entry *tt_common_entry;
1579         struct batadv_tt_query_packet *tt_response;
1580         struct batadv_tt_change *tt_change;
1581         struct hlist_node *node;
1582         struct hlist_head *head;
1583         struct sk_buff *skb = NULL;
1584         uint16_t tt_tot, tt_count;
1585         ssize_t tt_query_size = sizeof(struct batadv_tt_query_packet);
1586         uint32_t i;
1587         size_t len;
1588
1589         if (tt_query_size + tt_len > primary_if->soft_iface->mtu) {
1590                 tt_len = primary_if->soft_iface->mtu - tt_query_size;
1591                 tt_len -= tt_len % sizeof(struct batadv_tt_change);
1592         }
1593         tt_tot = tt_len / sizeof(struct batadv_tt_change);
1594
1595         len = tt_query_size + tt_len;
1596         skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1597         if (!skb)
1598                 goto out;
1599
1600         skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1601         tt_response = (struct batadv_tt_query_packet *)skb_put(skb, len);
1602         tt_response->ttvn = ttvn;
1603
1604         tt_change = (struct batadv_tt_change *)(skb->data + tt_query_size);
1605         tt_count = 0;
1606
1607         rcu_read_lock();
1608         for (i = 0; i < hash->size; i++) {
1609                 head = &hash->table[i];
1610
1611                 hlist_for_each_entry_rcu(tt_common_entry, node,
1612                                          head, hash_entry) {
1613                         if (tt_count == tt_tot)
1614                                 break;
1615
1616                         if ((valid_cb) && (!valid_cb(tt_common_entry, cb_data)))
1617                                 continue;
1618
1619                         memcpy(tt_change->addr, tt_common_entry->addr,
1620                                ETH_ALEN);
1621                         tt_change->flags = tt_common_entry->flags;
1622
1623                         tt_count++;
1624                         tt_change++;
1625                 }
1626         }
1627         rcu_read_unlock();
1628
1629         /* store in the message the number of entries we have successfully
1630          * copied
1631          */
1632         tt_response->tt_data = htons(tt_count);
1633
1634 out:
1635         return skb;
1636 }
1637
1638 static int batadv_send_tt_request(struct batadv_priv *bat_priv,
1639                                   struct batadv_orig_node *dst_orig_node,
1640                                   uint8_t ttvn, uint16_t tt_crc,
1641                                   bool full_table)
1642 {
1643         struct sk_buff *skb = NULL;
1644         struct batadv_tt_query_packet *tt_request;
1645         struct batadv_hard_iface *primary_if;
1646         struct batadv_tt_req_node *tt_req_node = NULL;
1647         int ret = 1;
1648         size_t tt_req_len;
1649
1650         primary_if = batadv_primary_if_get_selected(bat_priv);
1651         if (!primary_if)
1652                 goto out;
1653
1654         /* The new tt_req will be issued only if I'm not waiting for a
1655          * reply from the same orig_node yet
1656          */
1657         tt_req_node = batadv_new_tt_req_node(bat_priv, dst_orig_node);
1658         if (!tt_req_node)
1659                 goto out;
1660
1661         skb = dev_alloc_skb(sizeof(*tt_request) + ETH_HLEN + NET_IP_ALIGN);
1662         if (!skb)
1663                 goto out;
1664
1665         skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1666
1667         tt_req_len = sizeof(*tt_request);
1668         tt_request = (struct batadv_tt_query_packet *)skb_put(skb, tt_req_len);
1669
1670         tt_request->header.packet_type = BATADV_TT_QUERY;
1671         tt_request->header.version = BATADV_COMPAT_VERSION;
1672         memcpy(tt_request->src, primary_if->net_dev->dev_addr, ETH_ALEN);
1673         memcpy(tt_request->dst, dst_orig_node->orig, ETH_ALEN);
1674         tt_request->header.ttl = BATADV_TTL;
1675         tt_request->ttvn = ttvn;
1676         tt_request->tt_data = htons(tt_crc);
1677         tt_request->flags = BATADV_TT_REQUEST;
1678
1679         if (full_table)
1680                 tt_request->flags |= BATADV_TT_FULL_TABLE;
1681
1682         batadv_dbg(BATADV_DBG_TT, bat_priv, "Sending TT_REQUEST to %pM [%c]\n",
1683                    dst_orig_node->orig, (full_table ? 'F' : '.'));
1684
1685         batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_TX);
1686
1687         if (batadv_send_skb_to_orig(skb, dst_orig_node, NULL))
1688                 ret = 0;
1689
1690 out:
1691         if (primary_if)
1692                 batadv_hardif_free_ref(primary_if);
1693         if (ret)
1694                 kfree_skb(skb);
1695         if (ret && tt_req_node) {
1696                 spin_lock_bh(&bat_priv->tt.req_list_lock);
1697                 list_del(&tt_req_node->list);
1698                 spin_unlock_bh(&bat_priv->tt.req_list_lock);
1699                 kfree(tt_req_node);
1700         }
1701         return ret;
1702 }
1703
1704 static bool
1705 batadv_send_other_tt_response(struct batadv_priv *bat_priv,
1706                               struct batadv_tt_query_packet *tt_request)
1707 {
1708         struct batadv_orig_node *req_dst_orig_node;
1709         struct batadv_orig_node *res_dst_orig_node = NULL;
1710         struct batadv_hard_iface *primary_if = NULL;
1711         uint8_t orig_ttvn, req_ttvn, ttvn;
1712         int ret = false;
1713         unsigned char *tt_buff;
1714         bool full_table;
1715         uint16_t tt_len, tt_tot;
1716         struct sk_buff *skb = NULL;
1717         struct batadv_tt_query_packet *tt_response;
1718         uint8_t *packet_pos;
1719         size_t len;
1720
1721         batadv_dbg(BATADV_DBG_TT, bat_priv,
1722                    "Received TT_REQUEST from %pM for ttvn: %u (%pM) [%c]\n",
1723                    tt_request->src, tt_request->ttvn, tt_request->dst,
1724                    (tt_request->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1725
1726         /* Let's get the orig node of the REAL destination */
1727         req_dst_orig_node = batadv_orig_hash_find(bat_priv, tt_request->dst);
1728         if (!req_dst_orig_node)
1729                 goto out;
1730
1731         res_dst_orig_node = batadv_orig_hash_find(bat_priv, tt_request->src);
1732         if (!res_dst_orig_node)
1733                 goto out;
1734
1735         primary_if = batadv_primary_if_get_selected(bat_priv);
1736         if (!primary_if)
1737                 goto out;
1738
1739         orig_ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
1740         req_ttvn = tt_request->ttvn;
1741
1742         /* I don't have the requested data */
1743         if (orig_ttvn != req_ttvn ||
1744             tt_request->tt_data != htons(req_dst_orig_node->tt_crc))
1745                 goto out;
1746
1747         /* If the full table has been explicitly requested */
1748         if (tt_request->flags & BATADV_TT_FULL_TABLE ||
1749             !req_dst_orig_node->tt_buff)
1750                 full_table = true;
1751         else
1752                 full_table = false;
1753
1754         /* In this version, fragmentation is not implemented, then
1755          * I'll send only one packet with as much TT entries as I can
1756          */
1757         if (!full_table) {
1758                 spin_lock_bh(&req_dst_orig_node->tt_buff_lock);
1759                 tt_len = req_dst_orig_node->tt_buff_len;
1760                 tt_tot = tt_len / sizeof(struct batadv_tt_change);
1761
1762                 len = sizeof(*tt_response) + tt_len;
1763                 skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1764                 if (!skb)
1765                         goto unlock;
1766
1767                 skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1768                 packet_pos = skb_put(skb, len);
1769                 tt_response = (struct batadv_tt_query_packet *)packet_pos;
1770                 tt_response->ttvn = req_ttvn;
1771                 tt_response->tt_data = htons(tt_tot);
1772
1773                 tt_buff = skb->data + sizeof(*tt_response);
1774                 /* Copy the last orig_node's OGM buffer */
1775                 memcpy(tt_buff, req_dst_orig_node->tt_buff,
1776                        req_dst_orig_node->tt_buff_len);
1777
1778                 spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
1779         } else {
1780                 tt_len = (uint16_t)atomic_read(&req_dst_orig_node->tt_size);
1781                 tt_len *= sizeof(struct batadv_tt_change);
1782                 ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
1783
1784                 skb = batadv_tt_response_fill_table(tt_len, ttvn,
1785                                                     bat_priv->tt.global_hash,
1786                                                     primary_if,
1787                                                     batadv_tt_global_valid,
1788                                                     req_dst_orig_node);
1789                 if (!skb)
1790                         goto out;
1791
1792                 tt_response = (struct batadv_tt_query_packet *)skb->data;
1793         }
1794
1795         tt_response->header.packet_type = BATADV_TT_QUERY;
1796         tt_response->header.version = BATADV_COMPAT_VERSION;
1797         tt_response->header.ttl = BATADV_TTL;
1798         memcpy(tt_response->src, req_dst_orig_node->orig, ETH_ALEN);
1799         memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
1800         tt_response->flags = BATADV_TT_RESPONSE;
1801
1802         if (full_table)
1803                 tt_response->flags |= BATADV_TT_FULL_TABLE;
1804
1805         batadv_dbg(BATADV_DBG_TT, bat_priv,
1806                    "Sending TT_RESPONSE %pM for %pM (ttvn: %u)\n",
1807                    res_dst_orig_node->orig, req_dst_orig_node->orig, req_ttvn);
1808
1809         batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
1810
1811         if (batadv_send_skb_to_orig(skb, res_dst_orig_node, NULL))
1812                 ret = true;
1813         goto out;
1814
1815 unlock:
1816         spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
1817
1818 out:
1819         if (res_dst_orig_node)
1820                 batadv_orig_node_free_ref(res_dst_orig_node);
1821         if (req_dst_orig_node)
1822                 batadv_orig_node_free_ref(req_dst_orig_node);
1823         if (primary_if)
1824                 batadv_hardif_free_ref(primary_if);
1825         if (!ret)
1826                 kfree_skb(skb);
1827         return ret;
1828
1829 }
1830
1831 static bool
1832 batadv_send_my_tt_response(struct batadv_priv *bat_priv,
1833                            struct batadv_tt_query_packet *tt_request)
1834 {
1835         struct batadv_orig_node *orig_node;
1836         struct batadv_hard_iface *primary_if = NULL;
1837         uint8_t my_ttvn, req_ttvn, ttvn;
1838         int ret = false;
1839         unsigned char *tt_buff;
1840         bool full_table;
1841         uint16_t tt_len, tt_tot;
1842         struct sk_buff *skb = NULL;
1843         struct batadv_tt_query_packet *tt_response;
1844         uint8_t *packet_pos;
1845         size_t len;
1846
1847         batadv_dbg(BATADV_DBG_TT, bat_priv,
1848                    "Received TT_REQUEST from %pM for ttvn: %u (me) [%c]\n",
1849                    tt_request->src, tt_request->ttvn,
1850                    (tt_request->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1851
1852
1853         my_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
1854         req_ttvn = tt_request->ttvn;
1855
1856         orig_node = batadv_orig_hash_find(bat_priv, tt_request->src);
1857         if (!orig_node)
1858                 goto out;
1859
1860         primary_if = batadv_primary_if_get_selected(bat_priv);
1861         if (!primary_if)
1862                 goto out;
1863
1864         /* If the full table has been explicitly requested or the gap
1865          * is too big send the whole local translation table
1866          */
1867         if (tt_request->flags & BATADV_TT_FULL_TABLE || my_ttvn != req_ttvn ||
1868             !bat_priv->tt.last_changeset)
1869                 full_table = true;
1870         else
1871                 full_table = false;
1872
1873         /* In this version, fragmentation is not implemented, then
1874          * I'll send only one packet with as much TT entries as I can
1875          */
1876         if (!full_table) {
1877                 spin_lock_bh(&bat_priv->tt.last_changeset_lock);
1878                 tt_len = bat_priv->tt.last_changeset_len;
1879                 tt_tot = tt_len / sizeof(struct batadv_tt_change);
1880
1881                 len = sizeof(*tt_response) + tt_len;
1882                 skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1883                 if (!skb)
1884                         goto unlock;
1885
1886                 skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1887                 packet_pos = skb_put(skb, len);
1888                 tt_response = (struct batadv_tt_query_packet *)packet_pos;
1889                 tt_response->ttvn = req_ttvn;
1890                 tt_response->tt_data = htons(tt_tot);
1891
1892                 tt_buff = skb->data + sizeof(*tt_response);
1893                 memcpy(tt_buff, bat_priv->tt.last_changeset,
1894                        bat_priv->tt.last_changeset_len);
1895                 spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
1896         } else {
1897                 tt_len = (uint16_t)atomic_read(&bat_priv->tt.local_entry_num);
1898                 tt_len *= sizeof(struct batadv_tt_change);
1899                 ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
1900
1901                 skb = batadv_tt_response_fill_table(tt_len, ttvn,
1902                                                     bat_priv->tt.local_hash,
1903                                                     primary_if,
1904                                                     batadv_tt_local_valid_entry,
1905                                                     NULL);
1906                 if (!skb)
1907                         goto out;
1908
1909                 tt_response = (struct batadv_tt_query_packet *)skb->data;
1910         }
1911
1912         tt_response->header.packet_type = BATADV_TT_QUERY;
1913         tt_response->header.version = BATADV_COMPAT_VERSION;
1914         tt_response->header.ttl = BATADV_TTL;
1915         memcpy(tt_response->src, primary_if->net_dev->dev_addr, ETH_ALEN);
1916         memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
1917         tt_response->flags = BATADV_TT_RESPONSE;
1918
1919         if (full_table)
1920                 tt_response->flags |= BATADV_TT_FULL_TABLE;
1921
1922         batadv_dbg(BATADV_DBG_TT, bat_priv,
1923                    "Sending TT_RESPONSE to %pM [%c]\n",
1924                    orig_node->orig,
1925                    (tt_response->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1926
1927         batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
1928
1929         if (batadv_send_skb_to_orig(skb, orig_node, NULL))
1930                 ret = true;
1931         goto out;
1932
1933 unlock:
1934         spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
1935 out:
1936         if (orig_node)
1937                 batadv_orig_node_free_ref(orig_node);
1938         if (primary_if)
1939                 batadv_hardif_free_ref(primary_if);
1940         if (!ret)
1941                 kfree_skb(skb);
1942         /* This packet was for me, so it doesn't need to be re-routed */
1943         return true;
1944 }
1945
1946 bool batadv_send_tt_response(struct batadv_priv *bat_priv,
1947                              struct batadv_tt_query_packet *tt_request)
1948 {
1949         if (batadv_is_my_mac(tt_request->dst)) {
1950                 /* don't answer backbone gws! */
1951                 if (batadv_bla_is_backbone_gw_orig(bat_priv, tt_request->src))
1952                         return true;
1953
1954                 return batadv_send_my_tt_response(bat_priv, tt_request);
1955         } else {
1956                 return batadv_send_other_tt_response(bat_priv, tt_request);
1957         }
1958 }
1959
1960 static void _batadv_tt_update_changes(struct batadv_priv *bat_priv,
1961                                       struct batadv_orig_node *orig_node,
1962                                       struct batadv_tt_change *tt_change,
1963                                       uint16_t tt_num_changes, uint8_t ttvn)
1964 {
1965         int i;
1966         int roams;
1967
1968         for (i = 0; i < tt_num_changes; i++) {
1969                 if ((tt_change + i)->flags & BATADV_TT_CLIENT_DEL) {
1970                         roams = (tt_change + i)->flags & BATADV_TT_CLIENT_ROAM;
1971                         batadv_tt_global_del(bat_priv, orig_node,
1972                                              (tt_change + i)->addr,
1973                                              "tt removed by changes",
1974                                              roams);
1975                 } else {
1976                         if (!batadv_tt_global_add(bat_priv, orig_node,
1977                                                   (tt_change + i)->addr,
1978                                                   (tt_change + i)->flags, ttvn))
1979                                 /* In case of problem while storing a
1980                                  * global_entry, we stop the updating
1981                                  * procedure without committing the
1982                                  * ttvn change. This will avoid to send
1983                                  * corrupted data on tt_request
1984                                  */
1985                                 return;
1986                 }
1987         }
1988         orig_node->tt_initialised = true;
1989 }
1990
1991 static void batadv_tt_fill_gtable(struct batadv_priv *bat_priv,
1992                                   struct batadv_tt_query_packet *tt_response)
1993 {
1994         struct batadv_orig_node *orig_node;
1995
1996         orig_node = batadv_orig_hash_find(bat_priv, tt_response->src);
1997         if (!orig_node)
1998                 goto out;
1999
2000         /* Purge the old table first.. */
2001         batadv_tt_global_del_orig(bat_priv, orig_node, "Received full table");
2002
2003         _batadv_tt_update_changes(bat_priv, orig_node,
2004                                   (struct batadv_tt_change *)(tt_response + 1),
2005                                   ntohs(tt_response->tt_data),
2006                                   tt_response->ttvn);
2007
2008         spin_lock_bh(&orig_node->tt_buff_lock);
2009         kfree(orig_node->tt_buff);
2010         orig_node->tt_buff_len = 0;
2011         orig_node->tt_buff = NULL;
2012         spin_unlock_bh(&orig_node->tt_buff_lock);
2013
2014         atomic_set(&orig_node->last_ttvn, tt_response->ttvn);
2015
2016 out:
2017         if (orig_node)
2018                 batadv_orig_node_free_ref(orig_node);
2019 }
2020
2021 static void batadv_tt_update_changes(struct batadv_priv *bat_priv,
2022                                      struct batadv_orig_node *orig_node,
2023                                      uint16_t tt_num_changes, uint8_t ttvn,
2024                                      struct batadv_tt_change *tt_change)
2025 {
2026         _batadv_tt_update_changes(bat_priv, orig_node, tt_change,
2027                                   tt_num_changes, ttvn);
2028
2029         batadv_tt_save_orig_buffer(bat_priv, orig_node,
2030                                    (unsigned char *)tt_change, tt_num_changes);
2031         atomic_set(&orig_node->last_ttvn, ttvn);
2032 }
2033
2034 bool batadv_is_my_client(struct batadv_priv *bat_priv, const uint8_t *addr)
2035 {
2036         struct batadv_tt_local_entry *tt_local_entry;
2037         bool ret = false;
2038
2039         tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
2040         if (!tt_local_entry)
2041                 goto out;
2042         /* Check if the client has been logically deleted (but is kept for
2043          * consistency purpose)
2044          */
2045         if ((tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING) ||
2046             (tt_local_entry->common.flags & BATADV_TT_CLIENT_ROAM))
2047                 goto out;
2048         ret = true;
2049 out:
2050         if (tt_local_entry)
2051                 batadv_tt_local_entry_free_ref(tt_local_entry);
2052         return ret;
2053 }
2054
2055 void batadv_handle_tt_response(struct batadv_priv *bat_priv,
2056                                struct batadv_tt_query_packet *tt_response)
2057 {
2058         struct batadv_tt_req_node *node, *safe;
2059         struct batadv_orig_node *orig_node = NULL;
2060         struct batadv_tt_change *tt_change;
2061
2062         batadv_dbg(BATADV_DBG_TT, bat_priv,
2063                    "Received TT_RESPONSE from %pM for ttvn %d t_size: %d [%c]\n",
2064                    tt_response->src, tt_response->ttvn,
2065                    ntohs(tt_response->tt_data),
2066                    (tt_response->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
2067
2068         /* we should have never asked a backbone gw */
2069         if (batadv_bla_is_backbone_gw_orig(bat_priv, tt_response->src))
2070                 goto out;
2071
2072         orig_node = batadv_orig_hash_find(bat_priv, tt_response->src);
2073         if (!orig_node)
2074                 goto out;
2075
2076         if (tt_response->flags & BATADV_TT_FULL_TABLE) {
2077                 batadv_tt_fill_gtable(bat_priv, tt_response);
2078         } else {
2079                 tt_change = (struct batadv_tt_change *)(tt_response + 1);
2080                 batadv_tt_update_changes(bat_priv, orig_node,
2081                                          ntohs(tt_response->tt_data),
2082                                          tt_response->ttvn, tt_change);
2083         }
2084
2085         /* Delete the tt_req_node from pending tt_requests list */
2086         spin_lock_bh(&bat_priv->tt.req_list_lock);
2087         list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
2088                 if (!batadv_compare_eth(node->addr, tt_response->src))
2089                         continue;
2090                 list_del(&node->list);
2091                 kfree(node);
2092         }
2093         spin_unlock_bh(&bat_priv->tt.req_list_lock);
2094
2095         /* Recalculate the CRC for this orig_node and store it */
2096         orig_node->tt_crc = batadv_tt_global_crc(bat_priv, orig_node);
2097 out:
2098         if (orig_node)
2099                 batadv_orig_node_free_ref(orig_node);
2100 }
2101
2102 int batadv_tt_init(struct batadv_priv *bat_priv)
2103 {
2104         int ret;
2105
2106         ret = batadv_tt_local_init(bat_priv);
2107         if (ret < 0)
2108                 return ret;
2109
2110         ret = batadv_tt_global_init(bat_priv);
2111         if (ret < 0)
2112                 return ret;
2113
2114         batadv_tt_start_timer(bat_priv);
2115
2116         return 1;
2117 }
2118
2119 static void batadv_tt_roam_list_free(struct batadv_priv *bat_priv)
2120 {
2121         struct batadv_tt_roam_node *node, *safe;
2122
2123         spin_lock_bh(&bat_priv->tt.roam_list_lock);
2124
2125         list_for_each_entry_safe(node, safe, &bat_priv->tt.roam_list, list) {
2126                 list_del(&node->list);
2127                 kfree(node);
2128         }
2129
2130         spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2131 }
2132
2133 static void batadv_tt_roam_purge(struct batadv_priv *bat_priv)
2134 {
2135         struct batadv_tt_roam_node *node, *safe;
2136
2137         spin_lock_bh(&bat_priv->tt.roam_list_lock);
2138         list_for_each_entry_safe(node, safe, &bat_priv->tt.roam_list, list) {
2139                 if (!batadv_has_timed_out(node->first_time,
2140                                           BATADV_ROAMING_MAX_TIME))
2141                         continue;
2142
2143                 list_del(&node->list);
2144                 kfree(node);
2145         }
2146         spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2147 }
2148
2149 /* This function checks whether the client already reached the
2150  * maximum number of possible roaming phases. In this case the ROAMING_ADV
2151  * will not be sent.
2152  *
2153  * returns true if the ROAMING_ADV can be sent, false otherwise
2154  */
2155 static bool batadv_tt_check_roam_count(struct batadv_priv *bat_priv,
2156                                        uint8_t *client)
2157 {
2158         struct batadv_tt_roam_node *tt_roam_node;
2159         bool ret = false;
2160
2161         spin_lock_bh(&bat_priv->tt.roam_list_lock);
2162         /* The new tt_req will be issued only if I'm not waiting for a
2163          * reply from the same orig_node yet
2164          */
2165         list_for_each_entry(tt_roam_node, &bat_priv->tt.roam_list, list) {
2166                 if (!batadv_compare_eth(tt_roam_node->addr, client))
2167                         continue;
2168
2169                 if (batadv_has_timed_out(tt_roam_node->first_time,
2170                                          BATADV_ROAMING_MAX_TIME))
2171                         continue;
2172
2173                 if (!batadv_atomic_dec_not_zero(&tt_roam_node->counter))
2174                         /* Sorry, you roamed too many times! */
2175                         goto unlock;
2176                 ret = true;
2177                 break;
2178         }
2179
2180         if (!ret) {
2181                 tt_roam_node = kmalloc(sizeof(*tt_roam_node), GFP_ATOMIC);
2182                 if (!tt_roam_node)
2183                         goto unlock;
2184
2185                 tt_roam_node->first_time = jiffies;
2186                 atomic_set(&tt_roam_node->counter,
2187                            BATADV_ROAMING_MAX_COUNT - 1);
2188                 memcpy(tt_roam_node->addr, client, ETH_ALEN);
2189
2190                 list_add(&tt_roam_node->list, &bat_priv->tt.roam_list);
2191                 ret = true;
2192         }
2193
2194 unlock:
2195         spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2196         return ret;
2197 }
2198
2199 static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
2200                                  struct batadv_orig_node *orig_node)
2201 {
2202         struct sk_buff *skb = NULL;
2203         struct batadv_roam_adv_packet *roam_adv_packet;
2204         int ret = 1;
2205         struct batadv_hard_iface *primary_if;
2206         size_t len = sizeof(*roam_adv_packet);
2207
2208         /* before going on we have to check whether the client has
2209          * already roamed to us too many times
2210          */
2211         if (!batadv_tt_check_roam_count(bat_priv, client))
2212                 goto out;
2213
2214         skb = dev_alloc_skb(sizeof(*roam_adv_packet) + ETH_HLEN + NET_IP_ALIGN);
2215         if (!skb)
2216                 goto out;
2217
2218         skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
2219
2220         roam_adv_packet = (struct batadv_roam_adv_packet *)skb_put(skb, len);
2221
2222         roam_adv_packet->header.packet_type = BATADV_ROAM_ADV;
2223         roam_adv_packet->header.version = BATADV_COMPAT_VERSION;
2224         roam_adv_packet->header.ttl = BATADV_TTL;
2225         roam_adv_packet->reserved = 0;
2226         primary_if = batadv_primary_if_get_selected(bat_priv);
2227         if (!primary_if)
2228                 goto out;
2229         memcpy(roam_adv_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
2230         batadv_hardif_free_ref(primary_if);
2231         memcpy(roam_adv_packet->dst, orig_node->orig, ETH_ALEN);
2232         memcpy(roam_adv_packet->client, client, ETH_ALEN);
2233
2234         batadv_dbg(BATADV_DBG_TT, bat_priv,
2235                    "Sending ROAMING_ADV to %pM (client %pM)\n",
2236                    orig_node->orig, client);
2237
2238         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_TX);
2239
2240         if (batadv_send_skb_to_orig(skb, orig_node, NULL))
2241                 ret = 0;
2242
2243 out:
2244         if (ret && skb)
2245                 kfree_skb(skb);
2246         return;
2247 }
2248
2249 static void batadv_tt_purge(struct work_struct *work)
2250 {
2251         struct delayed_work *delayed_work;
2252         struct batadv_priv_tt *priv_tt;
2253         struct batadv_priv *bat_priv;
2254
2255         delayed_work = container_of(work, struct delayed_work, work);
2256         priv_tt = container_of(delayed_work, struct batadv_priv_tt, work);
2257         bat_priv = container_of(priv_tt, struct batadv_priv, tt);
2258
2259         batadv_tt_local_purge(bat_priv);
2260         batadv_tt_global_purge(bat_priv);
2261         batadv_tt_req_purge(bat_priv);
2262         batadv_tt_roam_purge(bat_priv);
2263
2264         batadv_tt_start_timer(bat_priv);
2265 }
2266
2267 void batadv_tt_free(struct batadv_priv *bat_priv)
2268 {
2269         cancel_delayed_work_sync(&bat_priv->tt.work);
2270
2271         batadv_tt_local_table_free(bat_priv);
2272         batadv_tt_global_table_free(bat_priv);
2273         batadv_tt_req_list_free(bat_priv);
2274         batadv_tt_changes_list_free(bat_priv);
2275         batadv_tt_roam_list_free(bat_priv);
2276
2277         kfree(bat_priv->tt.last_changeset);
2278 }
2279
2280 /* This function will enable or disable the specified flags for all the entries
2281  * in the given hash table and returns the number of modified entries
2282  */
2283 static uint16_t batadv_tt_set_flags(struct batadv_hashtable *hash,
2284                                     uint16_t flags, bool enable)
2285 {
2286         uint32_t i;
2287         uint16_t changed_num = 0;
2288         struct hlist_head *head;
2289         struct hlist_node *node;
2290         struct batadv_tt_common_entry *tt_common_entry;
2291
2292         if (!hash)
2293                 goto out;
2294
2295         for (i = 0; i < hash->size; i++) {
2296                 head = &hash->table[i];
2297
2298                 rcu_read_lock();
2299                 hlist_for_each_entry_rcu(tt_common_entry, node,
2300                                          head, hash_entry) {
2301                         if (enable) {
2302                                 if ((tt_common_entry->flags & flags) == flags)
2303                                         continue;
2304                                 tt_common_entry->flags |= flags;
2305                         } else {
2306                                 if (!(tt_common_entry->flags & flags))
2307                                         continue;
2308                                 tt_common_entry->flags &= ~flags;
2309                         }
2310                         changed_num++;
2311                 }
2312                 rcu_read_unlock();
2313         }
2314 out:
2315         return changed_num;
2316 }
2317
2318 /* Purge out all the tt local entries marked with BATADV_TT_CLIENT_PENDING */
2319 static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)
2320 {
2321         struct batadv_hashtable *hash = bat_priv->tt.local_hash;
2322         struct batadv_tt_common_entry *tt_common;
2323         struct batadv_tt_local_entry *tt_local;
2324         struct hlist_node *node, *node_tmp;
2325         struct hlist_head *head;
2326         spinlock_t *list_lock; /* protects write access to the hash lists */
2327         uint32_t i;
2328
2329         if (!hash)
2330                 return;
2331
2332         for (i = 0; i < hash->size; i++) {
2333                 head = &hash->table[i];
2334                 list_lock = &hash->list_locks[i];
2335
2336                 spin_lock_bh(list_lock);
2337                 hlist_for_each_entry_safe(tt_common, node, node_tmp, head,
2338                                           hash_entry) {
2339                         if (!(tt_common->flags & BATADV_TT_CLIENT_PENDING))
2340                                 continue;
2341
2342                         batadv_dbg(BATADV_DBG_TT, bat_priv,
2343                                    "Deleting local tt entry (%pM): pending\n",
2344                                    tt_common->addr);
2345
2346                         atomic_dec(&bat_priv->tt.local_entry_num);
2347                         hlist_del_rcu(node);
2348                         tt_local = container_of(tt_common,
2349                                                 struct batadv_tt_local_entry,
2350                                                 common);
2351                         batadv_tt_local_entry_free_ref(tt_local);
2352                 }
2353                 spin_unlock_bh(list_lock);
2354         }
2355
2356 }
2357
2358 static int batadv_tt_commit_changes(struct batadv_priv *bat_priv,
2359                                     unsigned char **packet_buff,
2360                                     int *packet_buff_len, int packet_min_len)
2361 {
2362         uint16_t changed_num = 0;
2363
2364         if (atomic_read(&bat_priv->tt.local_changes) < 1)
2365                 return -ENOENT;
2366
2367         changed_num = batadv_tt_set_flags(bat_priv->tt.local_hash,
2368                                           BATADV_TT_CLIENT_NEW, false);
2369
2370         /* all reset entries have to be counted as local entries */
2371         atomic_add(changed_num, &bat_priv->tt.local_entry_num);
2372         batadv_tt_local_purge_pending_clients(bat_priv);
2373         bat_priv->tt.local_crc = batadv_tt_local_crc(bat_priv);
2374
2375         /* Increment the TTVN only once per OGM interval */
2376         atomic_inc(&bat_priv->tt.vn);
2377         batadv_dbg(BATADV_DBG_TT, bat_priv,
2378                    "Local changes committed, updating to ttvn %u\n",
2379                    (uint8_t)atomic_read(&bat_priv->tt.vn));
2380
2381         /* reset the sending counter */
2382         atomic_set(&bat_priv->tt.ogm_append_cnt, BATADV_TT_OGM_APPEND_MAX);
2383
2384         return batadv_tt_changes_fill_buff(bat_priv, packet_buff,
2385                                            packet_buff_len, packet_min_len);
2386 }
2387
2388 /* when calling this function (hard_iface == primary_if) has to be true */
2389 int batadv_tt_append_diff(struct batadv_priv *bat_priv,
2390                           unsigned char **packet_buff, int *packet_buff_len,
2391                           int packet_min_len)
2392 {
2393         int tt_num_changes;
2394
2395         /* if at least one change happened */
2396         tt_num_changes = batadv_tt_commit_changes(bat_priv, packet_buff,
2397                                                   packet_buff_len,
2398                                                   packet_min_len);
2399
2400         /* if the changes have been sent often enough */
2401         if ((tt_num_changes < 0) &&
2402             (!batadv_atomic_dec_not_zero(&bat_priv->tt.ogm_append_cnt))) {
2403                 batadv_tt_realloc_packet_buff(packet_buff, packet_buff_len,
2404                                               packet_min_len, packet_min_len);
2405                 tt_num_changes = 0;
2406         }
2407
2408         return tt_num_changes;
2409 }
2410
2411 bool batadv_is_ap_isolated(struct batadv_priv *bat_priv, uint8_t *src,
2412                            uint8_t *dst)
2413 {
2414         struct batadv_tt_local_entry *tt_local_entry = NULL;
2415         struct batadv_tt_global_entry *tt_global_entry = NULL;
2416         bool ret = false;
2417
2418         if (!atomic_read(&bat_priv->ap_isolation))
2419                 goto out;
2420
2421         tt_local_entry = batadv_tt_local_hash_find(bat_priv, dst);
2422         if (!tt_local_entry)
2423                 goto out;
2424
2425         tt_global_entry = batadv_tt_global_hash_find(bat_priv, src);
2426         if (!tt_global_entry)
2427                 goto out;
2428
2429         if (!_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
2430                 goto out;
2431
2432         ret = true;
2433
2434 out:
2435         if (tt_global_entry)
2436                 batadv_tt_global_entry_free_ref(tt_global_entry);
2437         if (tt_local_entry)
2438                 batadv_tt_local_entry_free_ref(tt_local_entry);
2439         return ret;
2440 }
2441
2442 void batadv_tt_update_orig(struct batadv_priv *bat_priv,
2443                            struct batadv_orig_node *orig_node,
2444                            const unsigned char *tt_buff, uint8_t tt_num_changes,
2445                            uint8_t ttvn, uint16_t tt_crc)
2446 {
2447         uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
2448         bool full_table = true;
2449         struct batadv_tt_change *tt_change;
2450
2451         /* don't care about a backbone gateways updates. */
2452         if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig))
2453                 return;
2454
2455         /* orig table not initialised AND first diff is in the OGM OR the ttvn
2456          * increased by one -> we can apply the attached changes
2457          */
2458         if ((!orig_node->tt_initialised && ttvn == 1) ||
2459             ttvn - orig_ttvn == 1) {
2460                 /* the OGM could not contain the changes due to their size or
2461                  * because they have already been sent BATADV_TT_OGM_APPEND_MAX
2462                  * times.
2463                  * In this case send a tt request
2464                  */
2465                 if (!tt_num_changes) {
2466                         full_table = false;
2467                         goto request_table;
2468                 }
2469
2470                 tt_change = (struct batadv_tt_change *)tt_buff;
2471                 batadv_tt_update_changes(bat_priv, orig_node, tt_num_changes,
2472                                          ttvn, tt_change);
2473
2474                 /* Even if we received the precomputed crc with the OGM, we
2475                  * prefer to recompute it to spot any possible inconsistency
2476                  * in the global table
2477                  */
2478                 orig_node->tt_crc = batadv_tt_global_crc(bat_priv, orig_node);
2479
2480                 /* The ttvn alone is not enough to guarantee consistency
2481                  * because a single value could represent different states
2482                  * (due to the wrap around). Thus a node has to check whether
2483                  * the resulting table (after applying the changes) is still
2484                  * consistent or not. E.g. a node could disconnect while its
2485                  * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case
2486                  * checking the CRC value is mandatory to detect the
2487                  * inconsistency
2488                  */
2489                 if (orig_node->tt_crc != tt_crc)
2490                         goto request_table;
2491         } else {
2492                 /* if we missed more than one change or our tables are not
2493                  * in sync anymore -> request fresh tt data
2494                  */
2495                 if (!orig_node->tt_initialised || ttvn != orig_ttvn ||
2496                     orig_node->tt_crc != tt_crc) {
2497 request_table:
2498                         batadv_dbg(BATADV_DBG_TT, bat_priv,
2499                                    "TT inconsistency for %pM. Need to retrieve the correct information (ttvn: %u last_ttvn: %u crc: %u last_crc: %u num_changes: %u)\n",
2500                                    orig_node->orig, ttvn, orig_ttvn, tt_crc,
2501                                    orig_node->tt_crc, tt_num_changes);
2502                         batadv_send_tt_request(bat_priv, orig_node, ttvn,
2503                                                tt_crc, full_table);
2504                         return;
2505                 }
2506         }
2507 }
2508
2509 /* returns true whether we know that the client has moved from its old
2510  * originator to another one. This entry is kept is still kept for consistency
2511  * purposes
2512  */
2513 bool batadv_tt_global_client_is_roaming(struct batadv_priv *bat_priv,
2514                                         uint8_t *addr)
2515 {
2516         struct batadv_tt_global_entry *tt_global_entry;
2517         bool ret = false;
2518
2519         tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
2520         if (!tt_global_entry)
2521                 goto out;
2522
2523         ret = !!(tt_global_entry->common.flags & BATADV_TT_CLIENT_ROAM);
2524         batadv_tt_global_entry_free_ref(tt_global_entry);
2525 out:
2526         return ret;
2527 }
2528
2529 /**
2530  * batadv_tt_local_client_is_roaming - tells whether the client is roaming
2531  * @bat_priv: the bat priv with all the soft interface information
2532  * @addr: the MAC address of the local client to query
2533  *
2534  * Returns true if the local client is known to be roaming (it is not served by
2535  * this node anymore) or not. If yes, the client is still present in the table
2536  * to keep the latter consistent with the node TTVN
2537  */
2538 bool batadv_tt_local_client_is_roaming(struct batadv_priv *bat_priv,
2539                                        uint8_t *addr)
2540 {
2541         struct batadv_tt_local_entry *tt_local_entry;
2542         bool ret = false;
2543
2544         tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
2545         if (!tt_local_entry)
2546                 goto out;
2547
2548         ret = tt_local_entry->common.flags & BATADV_TT_CLIENT_ROAM;
2549         batadv_tt_local_entry_free_ref(tt_local_entry);
2550 out:
2551         return ret;
2552
2553 }
2554
2555 bool batadv_tt_add_temporary_global_entry(struct batadv_priv *bat_priv,
2556                                           struct batadv_orig_node *orig_node,
2557                                           const unsigned char *addr)
2558 {
2559         bool ret = false;
2560
2561         /* if the originator is a backbone node (meaning it belongs to the same
2562          * LAN of this node) the temporary client must not be added because to
2563          * reach such destination the node must use the LAN instead of the mesh
2564          */
2565         if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig))
2566                 goto out;
2567
2568         if (!batadv_tt_global_add(bat_priv, orig_node, addr,
2569                                   BATADV_TT_CLIENT_TEMP,
2570                                   atomic_read(&orig_node->last_ttvn)))
2571                 goto out;
2572
2573         batadv_dbg(BATADV_DBG_TT, bat_priv,
2574                    "Added temporary global client (addr: %pM orig: %pM)\n",
2575                    addr, orig_node->orig);
2576         ret = true;
2577 out:
2578         return ret;
2579 }