net/batman-adv/network-coding.c

   1 /* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Martin Hundebøll, Jeppe Ledet-Pedersen
   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 <linux/debugfs.h>
  21
  22 #include "main.h"
  23 #include "hash.h"
  24 #include "network-coding.h"
  25 #include "send.h"
  26 #include "originator.h"
  27 #include "hard-interface.h"
  28 #include "routing.h"
  29
  30 static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
  31 static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
  32
  33 static void batadv_nc_worker(struct work_struct *work);
  34 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
  35                                        struct batadv_hard_iface *recv_if);
  36
  37 /**
  38  * batadv_nc_init - one-time initialization for network coding
  39  */
  40 int __init batadv_nc_init(void)
  41 {
  42         int ret;
  43
  44         /* Register our packet type */
  45         ret = batadv_recv_handler_register(BATADV_CODED,
  46                                            batadv_nc_recv_coded_packet);
  47
  48         return ret;
  49 }
  50
  51 /**
  52  * batadv_nc_start_timer - initialise the nc periodic worker
  53  * @bat_priv: the bat priv with all the soft interface information
  54  */
  55 static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
  56 {
  57         queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
  58                            msecs_to_jiffies(10));
  59 }
  60
  61 /**
  62  * batadv_nc_mesh_init - initialise coding hash table and start house keeping
  63  * @bat_priv: the bat priv with all the soft interface information
  64  */
  65 int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
  66 {
  67         bat_priv->nc.timestamp_fwd_flush = jiffies;
  68         bat_priv->nc.timestamp_sniffed_purge = jiffies;
  69
  70         if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
  71                 return 0;
  72
  73         bat_priv->nc.coding_hash = batadv_hash_new(128);
  74         if (!bat_priv->nc.coding_hash)
  75                 goto err;
  76
  77         batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
  78                                    &batadv_nc_coding_hash_lock_class_key);
  79
  80         bat_priv->nc.decoding_hash = batadv_hash_new(128);
  81         if (!bat_priv->nc.decoding_hash)
  82                 goto err;
  83
  84         batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
  85                                    &batadv_nc_decoding_hash_lock_class_key);
  86
  87         INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
  88         batadv_nc_start_timer(bat_priv);
  89
  90         return 0;
  91
  92 err:
  93         return -ENOMEM;
  94 }
  95
  96 /**
  97  * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
  98  * @bat_priv: the bat priv with all the soft interface information
  99  */
 100 void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
 101 {
 102         atomic_set(&bat_priv->network_coding, 1);
 103         bat_priv->nc.min_tq = 200;
 104         bat_priv->nc.max_fwd_delay = 10;
 105         bat_priv->nc.max_buffer_time = 200;
 106 }
 107
 108 /**
 109  * batadv_nc_init_orig - initialise the nc fields of an orig_node
 110  * @orig_node: the orig_node which is going to be initialised
 111  */
 112 void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
 113 {
 114         INIT_LIST_HEAD(&orig_node->in_coding_list);
 115         INIT_LIST_HEAD(&orig_node->out_coding_list);
 116         spin_lock_init(&orig_node->in_coding_list_lock);
 117         spin_lock_init(&orig_node->out_coding_list_lock);
 118 }
 119
 120 /**
 121  * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove
 122  *  its refcount on the orig_node
 123  * @rcu: rcu pointer of the nc node
 124  */
 125 static void batadv_nc_node_free_rcu(struct rcu_head *rcu)
 126 {
 127         struct batadv_nc_node *nc_node;
 128
 129         nc_node = container_of(rcu, struct batadv_nc_node, rcu);
 130         batadv_orig_node_free_ref(nc_node->orig_node);
 131         kfree(nc_node);
 132 }
 133
 134 /**
 135  * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly
 136  * frees it
 137  * @nc_node: the nc node to free
 138  */
 139 static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
 140 {
 141         if (atomic_dec_and_test(&nc_node->refcount))
 142                 call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu);
 143 }
 144
 145 /**
 146  * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
 147  * frees it
 148  * @nc_path: the nc node to free
 149  */
 150 static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path)
 151 {
 152         if (atomic_dec_and_test(&nc_path->refcount))
 153                 kfree_rcu(nc_path, rcu);
 154 }
 155
 156 /**
 157  * batadv_nc_packet_free - frees nc packet
 158  * @nc_packet: the nc packet to free
 159  */
 160 static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet)
 161 {
 162         if (nc_packet->skb)
 163                 kfree_skb(nc_packet->skb);
 164
 165         batadv_nc_path_free_ref(nc_packet->nc_path);
 166         kfree(nc_packet);
 167 }
 168
 169 /**
 170  * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
 171  * @bat_priv: the bat priv with all the soft interface information
 172  * @nc_node: the nc node to check
 173  *
 174  * Returns true if the entry has to be purged now, false otherwise
 175  */
 176 static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
 177                                        struct batadv_nc_node *nc_node)
 178 {
 179         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 180                 return true;
 181
 182         return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
 183 }
 184
 185 /**
 186  * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
 187  * @bat_priv: the bat priv with all the soft interface information
 188  * @nc_path: the nc path to check
 189  *
 190  * Returns true if the entry has to be purged now, false otherwise
 191  */
 192 static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
 193                                               struct batadv_nc_path *nc_path)
 194 {
 195         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 196                 return true;
 197
 198         /* purge the path when no packets has been added for 10 times the
 199          * max_fwd_delay time
 200          */
 201         return batadv_has_timed_out(nc_path->last_valid,
 202                                     bat_priv->nc.max_fwd_delay * 10);
 203 }
 204
 205 /**
 206  * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
 207  * @bat_priv: the bat priv with all the soft interface information
 208  * @nc_path: the nc path to check
 209  *
 210  * Returns true if the entry has to be purged now, false otherwise
 211  */
 212 static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
 213                                                 struct batadv_nc_path *nc_path)
 214 {
 215         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 216                 return true;
 217
 218         /* purge the path when no packets has been added for 10 times the
 219          * max_buffer time
 220          */
 221         return batadv_has_timed_out(nc_path->last_valid,
 222                                     bat_priv->nc.max_buffer_time*10);
 223 }
 224
 225 /**
 226  * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
 227  *  entries
 228  * @bat_priv: the bat priv with all the soft interface information
 229  * @list: list of nc nodes
 230  * @lock: nc node list lock
 231  * @to_purge: function in charge to decide whether an entry has to be purged or
 232  *            not. This function takes the nc node as argument and has to return
 233  *            a boolean value: true if the entry has to be deleted, false
 234  *            otherwise
 235  */
 236 static void
 237 batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
 238                               struct list_head *list,
 239                               spinlock_t *lock,
 240                               bool (*to_purge)(struct batadv_priv *,
 241                                                struct batadv_nc_node *))
 242 {
 243         struct batadv_nc_node *nc_node, *nc_node_tmp;
 244
 245         /* For each nc_node in list */
 246         spin_lock_bh(lock);
 247         list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
 248                 /* if an helper function has been passed as parameter,
 249                  * ask it if the entry has to be purged or not
 250                  */
 251                 if (to_purge && !to_purge(bat_priv, nc_node))
 252                         continue;
 253
 254                 batadv_dbg(BATADV_DBG_NC, bat_priv,
 255                            "Removing nc_node %pM -> %pM\n",
 256                            nc_node->addr, nc_node->orig_node->orig);
 257                 list_del_rcu(&nc_node->list);
 258                 batadv_nc_node_free_ref(nc_node);
 259         }
 260         spin_unlock_bh(lock);
 261 }
 262
 263 /**
 264  * batadv_nc_purge_orig - purges all nc node data attached of the given
 265  *  originator
 266  * @bat_priv: the bat priv with all the soft interface information
 267  * @orig_node: orig_node with the nc node entries to be purged
 268  * @to_purge: function in charge to decide whether an entry has to be purged or
 269  *            not. This function takes the nc node as argument and has to return
 270  *            a boolean value: true is the entry has to be deleted, false
 271  *            otherwise
 272  */
 273 void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
 274                           struct batadv_orig_node *orig_node,
 275                           bool (*to_purge)(struct batadv_priv *,
 276                                            struct batadv_nc_node *))
 277 {
 278         /* Check ingoing nc_node's of this orig_node */
 279         batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
 280                                       &orig_node->in_coding_list_lock,
 281                                       to_purge);
 282
 283         /* Check outgoing nc_node's of this orig_node */
 284         batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
 285                                       &orig_node->out_coding_list_lock,
 286                                       to_purge);
 287 }
 288
 289 /**
 290  * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
 291  *  have timed out nc nodes
 292  * @bat_priv: the bat priv with all the soft interface information
 293  */
 294 static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
 295 {
 296         struct batadv_hashtable *hash = bat_priv->orig_hash;
 297         struct hlist_head *head;
 298         struct batadv_orig_node *orig_node;
 299         uint32_t i;
 300
 301         if (!hash)
 302                 return;
 303
 304         /* For each orig_node */
 305         for (i = 0; i < hash->size; i++) {
 306                 head = &hash->table[i];
 307
 308                 rcu_read_lock();
 309                 hlist_for_each_entry_rcu(orig_node, head, hash_entry)
 310                         batadv_nc_purge_orig(bat_priv, orig_node,
 311                                              batadv_nc_to_purge_nc_node);
 312                 rcu_read_unlock();
 313         }
 314 }
 315
 316 /**
 317  * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
 318  *  unused ones
 319  * @bat_priv: the bat priv with all the soft interface information
 320  * @hash: hash table containing the nc paths to check
 321  * @to_purge: function in charge to decide whether an entry has to be purged or
 322  *            not. This function takes the nc node as argument and has to return
 323  *            a boolean value: true is the entry has to be deleted, false
 324  *            otherwise
 325  */
 326 static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,
 327                                   struct batadv_hashtable *hash,
 328                                   bool (*to_purge)(struct batadv_priv *,
 329                                                    struct batadv_nc_path *))
 330 {
 331         struct hlist_head *head;
 332         struct hlist_node *node_tmp;
 333         struct batadv_nc_path *nc_path;
 334         spinlock_t *lock; /* Protects lists in hash */
 335         uint32_t i;
 336
 337         for (i = 0; i < hash->size; i++) {
 338                 head = &hash->table[i];
 339                 lock = &hash->list_locks[i];
 340
 341                 /* For each nc_path in this bin */
 342                 spin_lock_bh(lock);
 343                 hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) {
 344                         /* if an helper function has been passed as parameter,
 345                          * ask it if the entry has to be purged or not
 346                          */
 347                         if (to_purge && !to_purge(bat_priv, nc_path))
 348                                 continue;
 349
 350                         /* purging an non-empty nc_path should never happen, but
 351                          * is observed under high CPU load. Delay the purging
 352                          * until next iteration to allow the packet_list to be
 353                          * emptied first.
 354                          */
 355                         if (!unlikely(list_empty(&nc_path->packet_list))) {
 356                                 net_ratelimited_function(printk,
 357                                                          KERN_WARNING
 358                                                          "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
 359                                                          nc_path->prev_hop,
 360                                                          nc_path->next_hop);
 361                                 continue;
 362                         }
 363
 364                         /* nc_path is unused, so remove it */
 365                         batadv_dbg(BATADV_DBG_NC, bat_priv,
 366                                    "Remove nc_path %pM -> %pM\n",
 367                                    nc_path->prev_hop, nc_path->next_hop);
 368                         hlist_del_rcu(&nc_path->hash_entry);
 369                         batadv_nc_path_free_ref(nc_path);
 370                 }
 371                 spin_unlock_bh(lock);
 372         }
 373 }
 374
 375 /**
 376  * batadv_nc_hash_key_gen - computes the nc_path hash key
 377  * @key: buffer to hold the final hash key
 378  * @src: source ethernet mac address going into the hash key
 379  * @dst: destination ethernet mac address going into the hash key
 380  */
 381 static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src,
 382                                    const char *dst)
 383 {
 384         memcpy(key->prev_hop, src, sizeof(key->prev_hop));
 385         memcpy(key->next_hop, dst, sizeof(key->next_hop));
 386 }
 387
 388 /**
 389  * batadv_nc_hash_choose - compute the hash value for an nc path
 390  * @data: data to hash
 391  * @size: size of the hash table
 392  *
 393  * Returns the selected index in the hash table for the given data.
 394  */
 395 static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size)
 396 {
 397         const struct batadv_nc_path *nc_path = data;
 398         uint32_t hash = 0;
 399
 400         hash = batadv_hash_bytes(hash, &nc_path->prev_hop,
 401                                  sizeof(nc_path->prev_hop));
 402         hash = batadv_hash_bytes(hash, &nc_path->next_hop,
 403                                  sizeof(nc_path->next_hop));
 404
 405         hash += (hash << 3);
 406         hash ^= (hash >> 11);
 407         hash += (hash << 15);
 408
 409         return hash % size;
 410 }
 411
 412 /**
 413  * batadv_nc_hash_compare - comparing function used in the network coding hash
 414  *  tables
 415  * @node: node in the local table
 416  * @data2: second object to compare the node to
 417  *
 418  * Returns 1 if the two entry are the same, 0 otherwise
 419  */
 420 static int batadv_nc_hash_compare(const struct hlist_node *node,
 421                                   const void *data2)
 422 {
 423         const struct batadv_nc_path *nc_path1, *nc_path2;
 424
 425         nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
 426         nc_path2 = data2;
 427
 428         /* Return 1 if the two keys are identical */
 429         if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop,
 430                    sizeof(nc_path1->prev_hop)) != 0)
 431                 return 0;
 432
 433         if (memcmp(nc_path1->next_hop, nc_path2->next_hop,
 434                    sizeof(nc_path1->next_hop)) != 0)
 435                 return 0;
 436
 437         return 1;
 438 }
 439
 440 /**
 441  * batadv_nc_hash_find - search for an existing nc path and return it
 442  * @hash: hash table containing the nc path
 443  * @data: search key
 444  *
 445  * Returns the nc_path if found, NULL otherwise.
 446  */
 447 static struct batadv_nc_path *
 448 batadv_nc_hash_find(struct batadv_hashtable *hash,
 449                     void *data)
 450 {
 451         struct hlist_head *head;
 452         struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
 453         int index;
 454
 455         if (!hash)
 456                 return NULL;
 457
 458         index = batadv_nc_hash_choose(data, hash->size);
 459         head = &hash->table[index];
 460
 461         rcu_read_lock();
 462         hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
 463                 if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
 464                         continue;
 465
 466                 if (!atomic_inc_not_zero(&nc_path->refcount))
 467                         continue;
 468
 469                 nc_path_tmp = nc_path;
 470                 break;
 471         }
 472         rcu_read_unlock();
 473
 474         return nc_path_tmp;
 475 }
 476
 477 /**
 478  * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
 479  * @nc_packet: the nc packet to send
 480  */
 481 static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
 482 {
 483         batadv_send_skb_packet(nc_packet->skb,
 484                                nc_packet->neigh_node->if_incoming,
 485                                nc_packet->nc_path->next_hop);
 486         nc_packet->skb = NULL;
 487         batadv_nc_packet_free(nc_packet);
 488 }
 489
 490 /**
 491  * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
 492  * @bat_priv: the bat priv with all the soft interface information
 493  * @nc_path: the nc path the packet belongs to
 494  * @nc_packet: the nc packet to be checked
 495  *
 496  * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
 497  * timeout. If so, the packet is no longer kept and the entry deleted from the
 498  * queue. Has to be called with the appropriate locks.
 499  *
 500  * Returns false as soon as the entry in the fifo queue has not been timed out
 501  * yet and true otherwise.
 502  */
 503 static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
 504                                     struct batadv_nc_path *nc_path,
 505                                     struct batadv_nc_packet *nc_packet)
 506 {
 507         unsigned long timeout = bat_priv->nc.max_buffer_time;
 508         bool res = false;
 509
 510         /* Packets are added to tail, so the remaining packets did not time
 511          * out and we can stop processing the current queue
 512          */
 513         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
 514             !batadv_has_timed_out(nc_packet->timestamp, timeout))
 515                 goto out;
 516
 517         /* purge nc packet */
 518         list_del(&nc_packet->list);
 519         batadv_nc_packet_free(nc_packet);
 520
 521         res = true;
 522
 523 out:
 524         return res;
 525 }
 526
 527 /**
 528  * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
 529  * @bat_priv: the bat priv with all the soft interface information
 530  * @nc_path: the nc path the packet belongs to
 531  * @nc_packet: the nc packet to be checked
 532  *
 533  * Checks whether the given nc packet has hit its forward timeout. If so, the
 534  * packet is no longer delayed, immediately sent and the entry deleted from the
 535  * queue. Has to be called with the appropriate locks.
 536  *
 537  * Returns false as soon as the entry in the fifo queue has not been timed out
 538  * yet and true otherwise.
 539  */
 540 static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,
 541                                 struct batadv_nc_path *nc_path,
 542                                 struct batadv_nc_packet *nc_packet)
 543 {
 544         unsigned long timeout = bat_priv->nc.max_fwd_delay;
 545
 546         /* Packets are added to tail, so the remaining packets did not time
 547          * out and we can stop processing the current queue
 548          */
 549         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
 550             !batadv_has_timed_out(nc_packet->timestamp, timeout))
 551                 return false;
 552
 553         /* Send packet */
 554         batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 555         batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 556                            nc_packet->skb->len + ETH_HLEN);
 557         list_del(&nc_packet->list);
 558         batadv_nc_send_packet(nc_packet);
 559
 560         return true;
 561 }
 562
 563 /**
 564  * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
 565  *  nc packets
 566  * @bat_priv: the bat priv with all the soft interface information
 567  * @hash: to be processed hash table
 568  * @process_fn: Function called to process given nc packet. Should return true
 569  *              to encourage this function to proceed with the next packet.
 570  *              Otherwise the rest of the current queue is skipped.
 571  */
 572 static void
 573 batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,
 574                            struct batadv_hashtable *hash,
 575                            bool (*process_fn)(struct batadv_priv *,
 576                                               struct batadv_nc_path *,
 577                                               struct batadv_nc_packet *))
 578 {
 579         struct hlist_head *head;
 580         struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
 581         struct batadv_nc_path *nc_path;
 582         bool ret;
 583         int i;
 584
 585         if (!hash)
 586                 return;
 587
 588         /* Loop hash table bins */
 589         for (i = 0; i < hash->size; i++) {
 590                 head = &hash->table[i];
 591
 592                 /* Loop coding paths */
 593                 rcu_read_lock();
 594                 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
 595                         /* Loop packets */
 596                         spin_lock_bh(&nc_path->packet_list_lock);
 597                         list_for_each_entry_safe(nc_packet, nc_packet_tmp,
 598                                                  &nc_path->packet_list, list) {
 599                                 ret = process_fn(bat_priv, nc_path, nc_packet);
 600                                 if (!ret)
 601                                         break;
 602                         }
 603                         spin_unlock_bh(&nc_path->packet_list_lock);
 604                 }
 605                 rcu_read_unlock();
 606         }
 607 }
 608
 609 /**
 610  * batadv_nc_worker - periodic task for house keeping related to network coding
 611  * @work: kernel work struct
 612  */
 613 static void batadv_nc_worker(struct work_struct *work)
 614 {
 615         struct delayed_work *delayed_work;
 616         struct batadv_priv_nc *priv_nc;
 617         struct batadv_priv *bat_priv;
 618         unsigned long timeout;
 619
 620         delayed_work = container_of(work, struct delayed_work, work);
 621         priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
 622         bat_priv = container_of(priv_nc, struct batadv_priv, nc);
 623
 624         batadv_nc_purge_orig_hash(bat_priv);
 625         batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
 626                               batadv_nc_to_purge_nc_path_coding);
 627         batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
 628                               batadv_nc_to_purge_nc_path_decoding);
 629
 630         timeout = bat_priv->nc.max_fwd_delay;
 631
 632         if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {
 633                 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
 634                                            batadv_nc_fwd_flush);
 635                 bat_priv->nc.timestamp_fwd_flush = jiffies;
 636         }
 637
 638         if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
 639                                  bat_priv->nc.max_buffer_time)) {
 640                 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
 641                                            batadv_nc_sniffed_purge);
 642                 bat_priv->nc.timestamp_sniffed_purge = jiffies;
 643         }
 644
 645         /* Schedule a new check */
 646         batadv_nc_start_timer(bat_priv);
 647 }
 648
 649 /**
 650  * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
 651  *  coding or not
 652  * @bat_priv: the bat priv with all the soft interface information
 653  * @orig_node: neighboring orig node which may be used as nc candidate
 654  * @ogm_packet: incoming ogm packet also used for the checks
 655  *
 656  * Returns true if:
 657  *  1) The OGM must have the most recent sequence number.
 658  *  2) The TTL must be decremented by one and only one.
 659  *  3) The OGM must be received from the first hop from orig_node.
 660  *  4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
 661  */
 662 static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
 663                                     struct batadv_orig_node *orig_node,
 664                                     struct batadv_ogm_packet *ogm_packet)
 665 {
 666         if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno))
 667                 return false;
 668         if (orig_node->last_ttl != ogm_packet->header.ttl + 1)
 669                 return false;
 670         if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
 671                 return false;
 672         if (ogm_packet->tq < bat_priv->nc.min_tq)
 673                 return false;
 674
 675         return true;
 676 }
 677
 678 /**
 679  * batadv_nc_find_nc_node - search for an existing nc node and return it
 680  * @orig_node: orig node originating the ogm packet
 681  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
 682  *  (can be equal to orig_node)
 683  * @in_coding: traverse incoming or outgoing network coding list
 684  *
 685  * Returns the nc_node if found, NULL otherwise.
 686  */
 687 static struct batadv_nc_node
 688 *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
 689                         struct batadv_orig_node *orig_neigh_node,
 690                         bool in_coding)
 691 {
 692         struct batadv_nc_node *nc_node, *nc_node_out = NULL;
 693         struct list_head *list;
 694
 695         if (in_coding)
 696                 list = &orig_neigh_node->in_coding_list;
 697         else
 698                 list = &orig_neigh_node->out_coding_list;
 699
 700         /* Traverse list of nc_nodes to orig_node */
 701         rcu_read_lock();
 702         list_for_each_entry_rcu(nc_node, list, list) {
 703                 if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
 704                         continue;
 705
 706                 if (!atomic_inc_not_zero(&nc_node->refcount))
 707                         continue;
 708
 709                 /* Found a match */
 710                 nc_node_out = nc_node;
 711                 break;
 712         }
 713         rcu_read_unlock();
 714
 715         return nc_node_out;
 716 }
 717
 718 /**
 719  * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
 720  *  not found
 721  * @bat_priv: the bat priv with all the soft interface information
 722  * @orig_node: orig node originating the ogm packet
 723  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
 724  *  (can be equal to orig_node)
 725  * @in_coding: traverse incoming or outgoing network coding list
 726  *
 727  * Returns the nc_node if found or created, NULL in case of an error.
 728  */
 729 static struct batadv_nc_node
 730 *batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 731                        struct batadv_orig_node *orig_node,
 732                        struct batadv_orig_node *orig_neigh_node,
 733                        bool in_coding)
 734 {
 735         struct batadv_nc_node *nc_node;
 736         spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
 737         struct list_head *list;
 738
 739         /* Check if nc_node is already added */
 740         nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
 741
 742         /* Node found */
 743         if (nc_node)
 744                 return nc_node;
 745
 746         nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
 747         if (!nc_node)
 748                 return NULL;
 749
 750         if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
 751                 goto free;
 752
 753         /* Initialize nc_node */
 754         INIT_LIST_HEAD(&nc_node->list);
 755         memcpy(nc_node->addr, orig_node->orig, ETH_ALEN);
 756         nc_node->orig_node = orig_neigh_node;
 757         atomic_set(&nc_node->refcount, 2);
 758
 759         /* Select ingoing or outgoing coding node */
 760         if (in_coding) {
 761                 lock = &orig_neigh_node->in_coding_list_lock;
 762                 list = &orig_neigh_node->in_coding_list;
 763         } else {
 764                 lock = &orig_neigh_node->out_coding_list_lock;
 765                 list = &orig_neigh_node->out_coding_list;
 766         }
 767
 768         batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
 769                    nc_node->addr, nc_node->orig_node->orig);
 770
 771         /* Add nc_node to orig_node */
 772         spin_lock_bh(lock);
 773         list_add_tail_rcu(&nc_node->list, list);
 774         spin_unlock_bh(lock);
 775
 776         return nc_node;
 777
 778 free:
 779         kfree(nc_node);
 780         return NULL;
 781 }
 782
 783 /**
 784  * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs
 785  *  (best called on incoming OGMs)
 786  * @bat_priv: the bat priv with all the soft interface information
 787  * @orig_node: orig node originating the ogm packet
 788  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
 789  *  (can be equal to orig_node)
 790  * @ogm_packet: incoming ogm packet
 791  * @is_single_hop_neigh: orig_node is a single hop neighbor
 792  */
 793 void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
 794                               struct batadv_orig_node *orig_node,
 795                               struct batadv_orig_node *orig_neigh_node,
 796                               struct batadv_ogm_packet *ogm_packet,
 797                               int is_single_hop_neigh)
 798 {
 799         struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL;
 800
 801         /* Check if network coding is enabled */
 802         if (!atomic_read(&bat_priv->network_coding))
 803                 goto out;
 804
 805         /* accept ogms from 'good' neighbors and single hop neighbors */
 806         if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
 807             !is_single_hop_neigh)
 808                 goto out;
 809
 810         /* Add orig_node as in_nc_node on hop */
 811         in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
 812                                            orig_neigh_node, true);
 813         if (!in_nc_node)
 814                 goto out;
 815
 816         in_nc_node->last_seen = jiffies;
 817
 818         /* Add hop as out_nc_node on orig_node */
 819         out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
 820                                             orig_node, false);
 821         if (!out_nc_node)
 822                 goto out;
 823
 824         out_nc_node->last_seen = jiffies;
 825
 826 out:
 827         if (in_nc_node)
 828                 batadv_nc_node_free_ref(in_nc_node);
 829         if (out_nc_node)
 830                 batadv_nc_node_free_ref(out_nc_node);
 831 }
 832
 833 /**
 834  * batadv_nc_get_path - get existing nc_path or allocate a new one
 835  * @bat_priv: the bat priv with all the soft interface information
 836  * @hash: hash table containing the nc path
 837  * @src: ethernet source address - first half of the nc path search key
 838  * @dst: ethernet destination address - second half of the nc path search key
 839  *
 840  * Returns pointer to nc_path if the path was found or created, returns NULL
 841  * on error.
 842  */
 843 static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
 844                                                  struct batadv_hashtable *hash,
 845                                                  uint8_t *src,
 846                                                  uint8_t *dst)
 847 {
 848         int hash_added;
 849         struct batadv_nc_path *nc_path, nc_path_key;
 850
 851         batadv_nc_hash_key_gen(&nc_path_key, src, dst);
 852
 853         /* Search for existing nc_path */
 854         nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
 855
 856         if (nc_path) {
 857                 /* Set timestamp to delay removal of nc_path */
 858                 nc_path->last_valid = jiffies;
 859                 return nc_path;
 860         }
 861
 862         /* No existing nc_path was found; create a new */
 863         nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
 864
 865         if (!nc_path)
 866                 return NULL;
 867
 868         /* Initialize nc_path */
 869         INIT_LIST_HEAD(&nc_path->packet_list);
 870         spin_lock_init(&nc_path->packet_list_lock);
 871         atomic_set(&nc_path->refcount, 2);
 872         nc_path->last_valid = jiffies;
 873         memcpy(nc_path->next_hop, dst, ETH_ALEN);
 874         memcpy(nc_path->prev_hop, src, ETH_ALEN);
 875
 876         batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",
 877                    nc_path->prev_hop,
 878                    nc_path->next_hop);
 879
 880         /* Add nc_path to hash table */
 881         hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,
 882                                      batadv_nc_hash_choose, &nc_path_key,
 883                                      &nc_path->hash_entry);
 884
 885         if (hash_added < 0) {
 886                 kfree(nc_path);
 887                 return NULL;
 888         }
 889
 890         return nc_path;
 891 }
 892
 893 /**
 894  * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
 895  *  selection of a receiver with slightly lower TQ than the other
 896  * @tq: to be weighted tq value
 897  */
 898 static uint8_t batadv_nc_random_weight_tq(uint8_t tq)
 899 {
 900         uint8_t rand_val, rand_tq;
 901
 902         get_random_bytes(&rand_val, sizeof(rand_val));
 903
 904         /* randomize the estimated packet loss (max TQ - estimated TQ) */
 905         rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
 906
 907         /* normalize the randomized packet loss */
 908         rand_tq /= BATADV_TQ_MAX_VALUE;
 909
 910         /* convert to (randomized) estimated tq again */
 911         return BATADV_TQ_MAX_VALUE - rand_tq;
 912 }
 913
 914 /**
 915  * batadv_nc_memxor - XOR destination with source
 916  * @dst: byte array to XOR into
 917  * @src: byte array to XOR from
 918  * @len: length of destination array
 919  */
 920 static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
 921 {
 922         unsigned int i;
 923
 924         for (i = 0; i < len; ++i)
 925                 dst[i] ^= src[i];
 926 }
 927
 928 /**
 929  * batadv_nc_code_packets - code a received unicast_packet with an nc packet
 930  *  into a coded_packet and send it
 931  * @bat_priv: the bat priv with all the soft interface information
 932  * @skb: data skb to forward
 933  * @ethhdr: pointer to the ethernet header inside the skb
 934  * @nc_packet: structure containing the packet to the skb can be coded with
 935  * @neigh_node: next hop to forward packet to
 936  *
 937  * Returns true if both packets are consumed, false otherwise.
 938  */
 939 static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
 940                                    struct sk_buff *skb,
 941                                    struct ethhdr *ethhdr,
 942                                    struct batadv_nc_packet *nc_packet,
 943                                    struct batadv_neigh_node *neigh_node)
 944 {
 945         uint8_t tq_weighted_neigh, tq_weighted_coding;
 946         struct sk_buff *skb_dest, *skb_src;
 947         struct batadv_unicast_packet *packet1;
 948         struct batadv_unicast_packet *packet2;
 949         struct batadv_coded_packet *coded_packet;
 950         struct batadv_neigh_node *neigh_tmp, *router_neigh;
 951         struct batadv_neigh_node *router_coding = NULL;
 952         uint8_t *first_source, *first_dest, *second_source, *second_dest;
 953         __be32 packet_id1, packet_id2;
 954         size_t count;
 955         bool res = false;
 956         int coding_len;
 957         int unicast_size = sizeof(*packet1);
 958         int coded_size = sizeof(*coded_packet);
 959         int header_add = coded_size - unicast_size;
 960
 961         router_neigh = batadv_orig_node_get_router(neigh_node->orig_node);
 962         if (!router_neigh)
 963                 goto out;
 964
 965         neigh_tmp = nc_packet->neigh_node;
 966         router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node);
 967         if (!router_coding)
 968                 goto out;
 969
 970         tq_weighted_neigh = batadv_nc_random_weight_tq(router_neigh->tq_avg);
 971         tq_weighted_coding = batadv_nc_random_weight_tq(router_coding->tq_avg);
 972
 973         /* Select one destination for the MAC-header dst-field based on
 974          * weighted TQ-values.
 975          */
 976         if (tq_weighted_neigh >= tq_weighted_coding) {
 977                 /* Destination from nc_packet is selected for MAC-header */
 978                 first_dest = nc_packet->nc_path->next_hop;
 979                 first_source = nc_packet->nc_path->prev_hop;
 980                 second_dest = neigh_node->addr;
 981                 second_source = ethhdr->h_source;
 982                 packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
 983                 packet2 = (struct batadv_unicast_packet *)skb->data;
 984                 packet_id1 = nc_packet->packet_id;
 985                 packet_id2 = batadv_skb_crc32(skb,
 986                                               skb->data + sizeof(*packet2));
 987         } else {
 988                 /* Destination for skb is selected for MAC-header */
 989                 first_dest = neigh_node->addr;
 990                 first_source = ethhdr->h_source;
 991                 second_dest = nc_packet->nc_path->next_hop;
 992                 second_source = nc_packet->nc_path->prev_hop;
 993                 packet1 = (struct batadv_unicast_packet *)skb->data;
 994                 packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
 995                 packet_id1 = batadv_skb_crc32(skb,
 996                                               skb->data + sizeof(*packet1));
 997                 packet_id2 = nc_packet->packet_id;
 998         }
 999
1000         /* Instead of zero padding the smallest data buffer, we
1001          * code into the largest.
1002          */
1003         if (skb->len <= nc_packet->skb->len) {
1004                 skb_dest = nc_packet->skb;
1005                 skb_src = skb;
1006         } else {
1007                 skb_dest = skb;
1008                 skb_src = nc_packet->skb;
1009         }
1010
1011         /* coding_len is used when decoding the packet shorter packet */
1012         coding_len = skb_src->len - unicast_size;
1013
1014         if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
1015                 goto out;
1016
1017         skb_push(skb_dest, header_add);
1018
1019         coded_packet = (struct batadv_coded_packet *)skb_dest->data;
1020         skb_reset_mac_header(skb_dest);
1021
1022         coded_packet->header.packet_type = BATADV_CODED;
1023         coded_packet->header.version = BATADV_COMPAT_VERSION;
1024         coded_packet->header.ttl = packet1->header.ttl;
1025
1026         /* Info about first unicast packet */
1027         memcpy(coded_packet->first_source, first_source, ETH_ALEN);
1028         memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN);
1029         coded_packet->first_crc = packet_id1;
1030         coded_packet->first_ttvn = packet1->ttvn;
1031
1032         /* Info about second unicast packet */
1033         memcpy(coded_packet->second_dest, second_dest, ETH_ALEN);
1034         memcpy(coded_packet->second_source, second_source, ETH_ALEN);
1035         memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN);
1036         coded_packet->second_crc = packet_id2;
1037         coded_packet->second_ttl = packet2->header.ttl;
1038         coded_packet->second_ttvn = packet2->ttvn;
1039         coded_packet->coded_len = htons(coding_len);
1040
1041         /* This is where the magic happens: Code skb_src into skb_dest */
1042         batadv_nc_memxor(skb_dest->data + coded_size,
1043                          skb_src->data + unicast_size, coding_len);
1044
1045         /* Update counters accordingly */
1046         if (BATADV_SKB_CB(skb_src)->decoded &&
1047             BATADV_SKB_CB(skb_dest)->decoded) {
1048                 /* Both packets are recoded */
1049                 count = skb_src->len + ETH_HLEN;
1050                 count += skb_dest->len + ETH_HLEN;
1051                 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
1052                 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
1053         } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1054                    !BATADV_SKB_CB(skb_dest)->decoded) {
1055                 /* Both packets are newly coded */
1056                 count = skb_src->len + ETH_HLEN;
1057                 count += skb_dest->len + ETH_HLEN;
1058                 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
1059                 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
1060         } else if (BATADV_SKB_CB(skb_src)->decoded &&
1061                    !BATADV_SKB_CB(skb_dest)->decoded) {
1062                 /* skb_src recoded and skb_dest is newly coded */
1063                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1064                 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1065                                    skb_src->len + ETH_HLEN);
1066                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1067                 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1068                                    skb_dest->len + ETH_HLEN);
1069         } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1070                    BATADV_SKB_CB(skb_dest)->decoded) {
1071                 /* skb_src is newly coded and skb_dest is recoded */
1072                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1073                 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1074                                    skb_src->len + ETH_HLEN);
1075                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1076                 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1077                                    skb_dest->len + ETH_HLEN);
1078         }
1079
1080         /* skb_src is now coded into skb_dest, so free it */
1081         kfree_skb(skb_src);
1082
1083         /* avoid duplicate free of skb from nc_packet */
1084         nc_packet->skb = NULL;
1085         batadv_nc_packet_free(nc_packet);
1086
1087         /* Send the coded packet and return true */
1088         batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
1089         res = true;
1090 out:
1091         if (router_neigh)
1092                 batadv_neigh_node_free_ref(router_neigh);
1093         if (router_coding)
1094                 batadv_neigh_node_free_ref(router_coding);
1095         return res;
1096 }
1097
1098 /**
1099  * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1100  * @skb: data skb to forward
1101  * @dst: destination mac address of the other skb to code with
1102  * @src: source mac address of skb
1103  *
1104  * Whenever we network code a packet we have to check whether we received it in
1105  * a network coded form. If so, we may not be able to use it for coding because
1106  * some neighbors may also have received (overheard) the packet in the network
1107  * coded form without being able to decode it. It is hard to know which of the
1108  * neighboring nodes was able to decode the packet, therefore we can only
1109  * re-code the packet if the source of the previous encoded packet is involved.
1110  * Since the source encoded the packet we can be certain it has all necessary
1111  * decode information.
1112  *
1113  * Returns true if coding of a decoded packet is allowed.
1114  */
1115 static bool batadv_nc_skb_coding_possible(struct sk_buff *skb,
1116                                           uint8_t *dst, uint8_t *src)
1117 {
1118         if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
1119                 return false;
1120         else
1121                 return true;
1122 }
1123
1124 /**
1125  * batadv_nc_path_search - Find the coding path matching in_nc_node and
1126  *  out_nc_node to retrieve a buffered packet that can be used for coding.
1127  * @bat_priv: the bat priv with all the soft interface information
1128  * @in_nc_node: pointer to skb next hop's neighbor nc node
1129  * @out_nc_node: pointer to skb source's neighbor nc node
1130  * @skb: data skb to forward
1131  * @eth_dst: next hop mac address of skb
1132  *
1133  * Returns true if coding of a decoded skb is allowed.
1134  */
1135 static struct batadv_nc_packet *
1136 batadv_nc_path_search(struct batadv_priv *bat_priv,
1137                       struct batadv_nc_node *in_nc_node,
1138                       struct batadv_nc_node *out_nc_node,
1139                       struct sk_buff *skb,
1140                       uint8_t *eth_dst)
1141 {
1142         struct batadv_nc_path *nc_path, nc_path_key;
1143         struct batadv_nc_packet *nc_packet_out = NULL;
1144         struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
1145         struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
1146         int idx;
1147
1148         if (!hash)
1149                 return NULL;
1150
1151         /* Create almost path key */
1152         batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
1153                                out_nc_node->addr);
1154         idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
1155
1156         /* Check for coding opportunities in this nc_path */
1157         rcu_read_lock();
1158         hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
1159                 if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
1160                         continue;
1161
1162                 if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
1163                         continue;
1164
1165                 spin_lock_bh(&nc_path->packet_list_lock);
1166                 if (list_empty(&nc_path->packet_list)) {
1167                         spin_unlock_bh(&nc_path->packet_list_lock);
1168                         continue;
1169                 }
1170
1171                 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
1172                                          &nc_path->packet_list, list) {
1173                         if (!batadv_nc_skb_coding_possible(nc_packet->skb,
1174                                                            eth_dst,
1175                                                            in_nc_node->addr))
1176                                 continue;
1177
1178                         /* Coding opportunity is found! */
1179                         list_del(&nc_packet->list);
1180                         nc_packet_out = nc_packet;
1181                         break;
1182                 }
1183
1184                 spin_unlock_bh(&nc_path->packet_list_lock);
1185                 break;
1186         }
1187         rcu_read_unlock();
1188
1189         return nc_packet_out;
1190 }
1191
1192 /**
1193  * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1194  *  skb's sender (may be equal to the originator).
1195  * @bat_priv: the bat priv with all the soft interface information
1196  * @skb: data skb to forward
1197  * @eth_dst: next hop mac address of skb
1198  * @eth_src: source mac address of skb
1199  * @in_nc_node: pointer to skb next hop's neighbor nc node
1200  *
1201  * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
1202  */
1203 static struct batadv_nc_packet *
1204 batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
1205                          struct sk_buff *skb,
1206                          uint8_t *eth_dst,
1207                          uint8_t *eth_src,
1208                          struct batadv_nc_node *in_nc_node)
1209 {
1210         struct batadv_orig_node *orig_node;
1211         struct batadv_nc_node *out_nc_node;
1212         struct batadv_nc_packet *nc_packet = NULL;
1213
1214         orig_node = batadv_orig_hash_find(bat_priv, eth_src);
1215         if (!orig_node)
1216                 return NULL;
1217
1218         rcu_read_lock();
1219         list_for_each_entry_rcu(out_nc_node,
1220                                 &orig_node->out_coding_list, list) {
1221                 /* Check if the skb is decoded and if recoding is possible */
1222                 if (!batadv_nc_skb_coding_possible(skb,
1223                                                    out_nc_node->addr, eth_src))
1224                         continue;
1225
1226                 /* Search for an opportunity in this nc_path */
1227                 nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
1228                                                   out_nc_node, skb, eth_dst);
1229                 if (nc_packet)
1230                         break;
1231         }
1232         rcu_read_unlock();
1233
1234         batadv_orig_node_free_ref(orig_node);
1235         return nc_packet;
1236 }
1237
1238 /**
1239  * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1240  *  unicast skb before it is stored for use in later decoding
1241  * @bat_priv: the bat priv with all the soft interface information
1242  * @skb: data skb to store
1243  * @eth_dst_new: new destination mac address of skb
1244  */
1245 static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
1246                                               struct sk_buff *skb,
1247                                               uint8_t *eth_dst_new)
1248 {
1249         struct ethhdr *ethhdr;
1250
1251         /* Copy skb header to change the mac header */
1252         skb = pskb_copy(skb, GFP_ATOMIC);
1253         if (!skb)
1254                 return;
1255
1256         /* Set the mac header as if we actually sent the packet uncoded */
1257         ethhdr = eth_hdr(skb);
1258         memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN);
1259         memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN);
1260
1261         /* Set data pointer to MAC header to mimic packets from our tx path */
1262         skb_push(skb, ETH_HLEN);
1263
1264         /* Add the packet to the decoding packet pool */
1265         batadv_nc_skb_store_for_decoding(bat_priv, skb);
1266
1267         /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1268          * our ref
1269          */
1270         kfree_skb(skb);
1271 }
1272
1273 /**
1274  * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1275  * @skb: data skb to forward
1276  * @neigh_node: next hop to forward packet to
1277  * @ethhdr: pointer to the ethernet header inside the skb
1278  *
1279  * Loops through list of neighboring nodes the next hop has a good connection to
1280  * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1281  * next hop that potentially sent a packet which our next hop also received
1282  * (overheard) and has stored for later decoding.
1283  *
1284  * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1285  */
1286 static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
1287                                      struct batadv_neigh_node *neigh_node,
1288                                      struct ethhdr *ethhdr)
1289 {
1290         struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1291         struct batadv_priv *bat_priv = netdev_priv(netdev);
1292         struct batadv_orig_node *orig_node = neigh_node->orig_node;
1293         struct batadv_nc_node *nc_node;
1294         struct batadv_nc_packet *nc_packet = NULL;
1295
1296         rcu_read_lock();
1297         list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
1298                 /* Search for coding opportunity with this in_nc_node */
1299                 nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
1300                                                      neigh_node->addr,
1301                                                      ethhdr->h_source, nc_node);
1302
1303                 /* Opportunity was found, so stop searching */
1304                 if (nc_packet)
1305                         break;
1306         }
1307         rcu_read_unlock();
1308
1309         if (!nc_packet)
1310                 return false;
1311
1312         /* Save packets for later decoding */
1313         batadv_nc_skb_store_before_coding(bat_priv, skb,
1314                                           neigh_node->addr);
1315         batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
1316                                           nc_packet->neigh_node->addr);
1317
1318         /* Code and send packets */
1319         if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
1320                                    neigh_node))
1321                 return true;
1322
1323         /* out of mem ? Coding failed - we have to free the buffered packet
1324          * to avoid memleaks. The skb passed as argument will be dealt with
1325          * by the calling function.
1326          */
1327         batadv_nc_send_packet(nc_packet);
1328         return false;
1329 }
1330
1331 /**
1332  * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1333  * @skb: skb to add to path
1334  * @nc_path: path to add skb to
1335  * @neigh_node: next hop to forward packet to
1336  * @packet_id: checksum to identify packet
1337  *
1338  * Returns true if the packet was buffered or false in case of an error.
1339  */
1340 static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,
1341                                       struct batadv_nc_path *nc_path,
1342                                       struct batadv_neigh_node *neigh_node,
1343                                       __be32 packet_id)
1344 {
1345         struct batadv_nc_packet *nc_packet;
1346
1347         nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
1348         if (!nc_packet)
1349                 return false;
1350
1351         /* Initialize nc_packet */
1352         nc_packet->timestamp = jiffies;
1353         nc_packet->packet_id = packet_id;
1354         nc_packet->skb = skb;
1355         nc_packet->neigh_node = neigh_node;
1356         nc_packet->nc_path = nc_path;
1357
1358         /* Add coding packet to list */
1359         spin_lock_bh(&nc_path->packet_list_lock);
1360         list_add_tail(&nc_packet->list, &nc_path->packet_list);
1361         spin_unlock_bh(&nc_path->packet_list_lock);
1362
1363         return true;
1364 }
1365
1366 /**
1367  * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1368  *  buffer
1369  * @skb: data skb to forward
1370  * @neigh_node: next hop to forward packet to
1371  *
1372  * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1373  */
1374 bool batadv_nc_skb_forward(struct sk_buff *skb,
1375                            struct batadv_neigh_node *neigh_node)
1376 {
1377         const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1378         struct batadv_priv *bat_priv = netdev_priv(netdev);
1379         struct batadv_unicast_packet *packet;
1380         struct batadv_nc_path *nc_path;
1381         struct ethhdr *ethhdr = eth_hdr(skb);
1382         __be32 packet_id;
1383         u8 *payload;
1384
1385         /* Check if network coding is enabled */
1386         if (!atomic_read(&bat_priv->network_coding))
1387                 goto out;
1388
1389         /* We only handle unicast packets */
1390         payload = skb_network_header(skb);
1391         packet = (struct batadv_unicast_packet *)payload;
1392         if (packet->header.packet_type != BATADV_UNICAST)
1393                 goto out;
1394
1395         /* Try to find a coding opportunity and send the skb if one is found */
1396         if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
1397                 return true;
1398
1399         /* Find or create a nc_path for this src-dst pair */
1400         nc_path = batadv_nc_get_path(bat_priv,
1401                                      bat_priv->nc.coding_hash,
1402                                      ethhdr->h_source,
1403                                      neigh_node->addr);
1404
1405         if (!nc_path)
1406                 goto out;
1407
1408         /* Add skb to nc_path */
1409         packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1410         if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))
1411                 goto free_nc_path;
1412
1413         /* Packet is consumed */
1414         return true;
1415
1416 free_nc_path:
1417         batadv_nc_path_free_ref(nc_path);
1418 out:
1419         /* Packet is not consumed */
1420         return false;
1421 }
1422
1423 /**
1424  * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1425  *  when decoding coded packets
1426  * @bat_priv: the bat priv with all the soft interface information
1427  * @skb: data skb to store
1428  */
1429 void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
1430                                       struct sk_buff *skb)
1431 {
1432         struct batadv_unicast_packet *packet;
1433         struct batadv_nc_path *nc_path;
1434         struct ethhdr *ethhdr = eth_hdr(skb);
1435         __be32 packet_id;
1436         u8 *payload;
1437
1438         /* Check if network coding is enabled */
1439         if (!atomic_read(&bat_priv->network_coding))
1440                 goto out;
1441
1442         /* Check for supported packet type */
1443         payload = skb_network_header(skb);
1444         packet = (struct batadv_unicast_packet *)payload;
1445         if (packet->header.packet_type != BATADV_UNICAST)
1446                 goto out;
1447
1448         /* Find existing nc_path or create a new */
1449         nc_path = batadv_nc_get_path(bat_priv,
1450                                      bat_priv->nc.decoding_hash,
1451                                      ethhdr->h_source,
1452                                      ethhdr->h_dest);
1453
1454         if (!nc_path)
1455                 goto out;
1456
1457         /* Clone skb and adjust skb->data to point at batman header */
1458         skb = skb_clone(skb, GFP_ATOMIC);
1459         if (unlikely(!skb))
1460                 goto free_nc_path;
1461
1462         if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
1463                 goto free_skb;
1464
1465         if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
1466                 goto free_skb;
1467
1468         /* Add skb to nc_path */
1469         packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1470         if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
1471                 goto free_skb;
1472
1473         batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
1474         return;
1475
1476 free_skb:
1477         kfree_skb(skb);
1478 free_nc_path:
1479         batadv_nc_path_free_ref(nc_path);
1480 out:
1481         return;
1482 }
1483
1484 /**
1485  * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1486  *  should be saved in the decoding buffer and, if so, store it there
1487  * @bat_priv: the bat priv with all the soft interface information
1488  * @skb: unicast skb to store
1489  */
1490 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
1491                                          struct sk_buff *skb)
1492 {
1493         struct ethhdr *ethhdr = eth_hdr(skb);
1494
1495         if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
1496                 return;
1497
1498         /* Set data pointer to MAC header to mimic packets from our tx path */
1499         skb_push(skb, ETH_HLEN);
1500
1501         batadv_nc_skb_store_for_decoding(bat_priv, skb);
1502 }
1503
1504 /**
1505  * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1506  *  in nc_packet
1507  * @bat_priv: the bat priv with all the soft interface information
1508  * @skb: unicast skb to decode
1509  * @nc_packet: decode data needed to decode the skb
1510  *
1511  * Returns pointer to decoded unicast packet if the packet was decoded or NULL
1512  * in case of an error.
1513  */
1514 static struct batadv_unicast_packet *
1515 batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
1516                             struct batadv_nc_packet *nc_packet)
1517 {
1518         const int h_size = sizeof(struct batadv_unicast_packet);
1519         const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
1520         struct batadv_unicast_packet *unicast_packet;
1521         struct batadv_coded_packet coded_packet_tmp;
1522         struct ethhdr *ethhdr, ethhdr_tmp;
1523         uint8_t *orig_dest, ttl, ttvn;
1524         unsigned int coding_len;
1525         int err;
1526
1527         /* Save headers temporarily */
1528         memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
1529         memcpy(&ethhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
1530
1531         if (skb_cow(skb, 0) < 0)
1532                 return NULL;
1533
1534         if (unlikely(!skb_pull_rcsum(skb, h_diff)))
1535                 return NULL;
1536
1537         /* Data points to batman header, so set mac header 14 bytes before
1538          * and network to data
1539          */
1540         skb_set_mac_header(skb, -ETH_HLEN);
1541         skb_reset_network_header(skb);
1542
1543         /* Reconstruct original mac header */
1544         ethhdr = eth_hdr(skb);
1545         memcpy(ethhdr, &ethhdr_tmp, sizeof(*ethhdr));
1546
1547         /* Select the correct unicast header information based on the location
1548          * of our mac address in the coded_packet header
1549          */
1550         if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
1551                 /* If we are the second destination the packet was overheard,
1552                  * so the Ethernet address must be copied to h_dest and
1553                  * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1554                  */
1555                 memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN);
1556                 skb->pkt_type = PACKET_HOST;
1557
1558                 orig_dest = coded_packet_tmp.second_orig_dest;
1559                 ttl = coded_packet_tmp.second_ttl;
1560                 ttvn = coded_packet_tmp.second_ttvn;
1561         } else {
1562                 orig_dest = coded_packet_tmp.first_orig_dest;
1563                 ttl = coded_packet_tmp.header.ttl;
1564                 ttvn = coded_packet_tmp.first_ttvn;
1565         }
1566
1567         coding_len = ntohs(coded_packet_tmp.coded_len);
1568
1569         if (coding_len > skb->len)
1570                 return NULL;
1571
1572         /* Here the magic is reversed:
1573          *   extract the missing packet from the received coded packet
1574          */
1575         batadv_nc_memxor(skb->data + h_size,
1576                          nc_packet->skb->data + h_size,
1577                          coding_len);
1578
1579         /* Resize decoded skb if decoded with larger packet */
1580         if (nc_packet->skb->len > coding_len + h_size) {
1581                 err = pskb_trim_rcsum(skb, coding_len + h_size);
1582                 if (err)
1583                         return NULL;
1584         }
1585
1586         /* Create decoded unicast packet */
1587         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1588         unicast_packet->header.packet_type = BATADV_UNICAST;
1589         unicast_packet->header.version = BATADV_COMPAT_VERSION;
1590         unicast_packet->header.ttl = ttl;
1591         memcpy(unicast_packet->dest, orig_dest, ETH_ALEN);
1592         unicast_packet->ttvn = ttvn;
1593
1594         batadv_nc_packet_free(nc_packet);
1595         return unicast_packet;
1596 }
1597
1598 /**
1599  * batadv_nc_find_decoding_packet - search through buffered decoding data to
1600  *  find the data needed to decode the coded packet
1601  * @bat_priv: the bat priv with all the soft interface information
1602  * @ethhdr: pointer to the ethernet header inside the coded packet
1603  * @coded: coded packet we try to find decode data for
1604  *
1605  * Returns pointer to nc packet if the needed data was found or NULL otherwise.
1606  */
1607 static struct batadv_nc_packet *
1608 batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
1609                                struct ethhdr *ethhdr,
1610                                struct batadv_coded_packet *coded)
1611 {
1612         struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
1613         struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
1614         struct batadv_nc_path *nc_path, nc_path_key;
1615         uint8_t *dest, *source;
1616         __be32 packet_id;
1617         int index;
1618
1619         if (!hash)
1620                 return NULL;
1621
1622         /* Select the correct packet id based on the location of our mac-addr */
1623         dest = ethhdr->h_source;
1624         if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
1625                 source = coded->second_source;
1626                 packet_id = coded->second_crc;
1627         } else {
1628                 source = coded->first_source;
1629                 packet_id = coded->first_crc;
1630         }
1631
1632         batadv_nc_hash_key_gen(&nc_path_key, source, dest);
1633         index = batadv_nc_hash_choose(&nc_path_key, hash->size);
1634
1635         /* Search for matching coding path */
1636         rcu_read_lock();
1637         hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
1638                 /* Find matching nc_packet */
1639                 spin_lock_bh(&nc_path->packet_list_lock);
1640                 list_for_each_entry(tmp_nc_packet,
1641                                     &nc_path->packet_list, list) {
1642                         if (packet_id == tmp_nc_packet->packet_id) {
1643                                 list_del(&tmp_nc_packet->list);
1644
1645                                 nc_packet = tmp_nc_packet;
1646                                 break;
1647                         }
1648                 }
1649                 spin_unlock_bh(&nc_path->packet_list_lock);
1650
1651                 if (nc_packet)
1652                         break;
1653         }
1654         rcu_read_unlock();
1655
1656         if (!nc_packet)
1657                 batadv_dbg(BATADV_DBG_NC, bat_priv,
1658                            "No decoding packet found for %u\n", packet_id);
1659
1660         return nc_packet;
1661 }
1662
1663 /**
1664  * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1665  *  resulting unicast packet
1666  * @skb: incoming coded packet
1667  * @recv_if: pointer to interface this packet was received on
1668  */
1669 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
1670                                        struct batadv_hard_iface *recv_if)
1671 {
1672         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1673         struct batadv_unicast_packet *unicast_packet;
1674         struct batadv_coded_packet *coded_packet;
1675         struct batadv_nc_packet *nc_packet;
1676         struct ethhdr *ethhdr;
1677         int hdr_size = sizeof(*coded_packet);
1678
1679         /* Check if network coding is enabled */
1680         if (!atomic_read(&bat_priv->network_coding))
1681                 return NET_RX_DROP;
1682
1683         /* Make sure we can access (and remove) header */
1684         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1685                 return NET_RX_DROP;
1686
1687         coded_packet = (struct batadv_coded_packet *)skb->data;
1688         ethhdr = eth_hdr(skb);
1689
1690         /* Verify frame is destined for us */
1691         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
1692             !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1693                 return NET_RX_DROP;
1694
1695         /* Update stat counter */
1696         if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1697                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
1698
1699         nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
1700                                                    coded_packet);
1701         if (!nc_packet) {
1702                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1703                 return NET_RX_DROP;
1704         }
1705
1706         /* Make skb's linear, because decoding accesses the entire buffer */
1707         if (skb_linearize(skb) < 0)
1708                 goto free_nc_packet;
1709
1710         if (skb_linearize(nc_packet->skb) < 0)
1711                 goto free_nc_packet;
1712
1713         /* Decode the packet */
1714         unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
1715         if (!unicast_packet) {
1716                 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1717                 goto free_nc_packet;
1718         }
1719
1720         /* Mark packet as decoded to do correct recoding when forwarding */
1721         BATADV_SKB_CB(skb)->decoded = true;
1722         batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
1723         batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
1724                            skb->len + ETH_HLEN);
1725         return batadv_recv_unicast_packet(skb, recv_if);
1726
1727 free_nc_packet:
1728         batadv_nc_packet_free(nc_packet);
1729         return NET_RX_DROP;
1730 }
1731
1732 /**
1733  * batadv_nc_mesh_free - clean up network coding memory
1734  * @bat_priv: the bat priv with all the soft interface information
1735  */
1736 void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
1737 {
1738         cancel_delayed_work_sync(&bat_priv->nc.work);
1739
1740         batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
1741         batadv_hash_destroy(bat_priv->nc.coding_hash);
1742         batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
1743         batadv_hash_destroy(bat_priv->nc.decoding_hash);
1744 }
1745
1746 /**
1747  * batadv_nc_nodes_seq_print_text - print the nc node information
1748  * @seq: seq file to print on
1749  * @offset: not used
1750  */
1751 int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
1752 {
1753         struct net_device *net_dev = (struct net_device *)seq->private;
1754         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1755         struct batadv_hashtable *hash = bat_priv->orig_hash;
1756         struct batadv_hard_iface *primary_if;
1757         struct hlist_head *head;
1758         struct batadv_orig_node *orig_node;
1759         struct batadv_nc_node *nc_node;
1760         int i;
1761
1762         primary_if = batadv_seq_print_text_primary_if_get(seq);
1763         if (!primary_if)
1764                 goto out;
1765
1766         /* Traverse list of originators */
1767         for (i = 0; i < hash->size; i++) {
1768                 head = &hash->table[i];
1769
1770                 /* For each orig_node in this bin */
1771                 rcu_read_lock();
1772                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1773                         /* no need to print the orig node if it does not have
1774                          * network coding neighbors
1775                          */
1776                         if (list_empty(&orig_node->in_coding_list) &&
1777                             list_empty(&orig_node->out_coding_list))
1778                                 continue;
1779
1780                         seq_printf(seq, "Node:      %pM\n", orig_node->orig);
1781
1782                         seq_puts(seq, " Ingoing:  ");
1783                         /* For each in_nc_node to this orig_node */
1784                         list_for_each_entry_rcu(nc_node,
1785                                                 &orig_node->in_coding_list,
1786                                                 list)
1787                                 seq_printf(seq, "%pM ",
1788                                            nc_node->addr);
1789                         seq_puts(seq, "\n");
1790
1791                         seq_puts(seq, " Outgoing: ");
1792                         /* For out_nc_node to this orig_node */
1793                         list_for_each_entry_rcu(nc_node,
1794                                                 &orig_node->out_coding_list,
1795                                                 list)
1796                                 seq_printf(seq, "%pM ",
1797                                            nc_node->addr);
1798                         seq_puts(seq, "\n\n");
1799                 }
1800                 rcu_read_unlock();
1801         }
1802
1803 out:
1804         if (primary_if)
1805                 batadv_hardif_free_ref(primary_if);
1806         return 0;
1807 }
1808
1809 /**
1810  * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1811  * @bat_priv: the bat priv with all the soft interface information
1812  */
1813 int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
1814 {
1815         struct dentry *nc_dir, *file;
1816
1817         nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
1818         if (!nc_dir)
1819                 goto out;
1820
1821         file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
1822                                  &bat_priv->nc.min_tq);
1823         if (!file)
1824                 goto out;
1825
1826         file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,
1827                                   &bat_priv->nc.max_fwd_delay);
1828         if (!file)
1829                 goto out;
1830
1831         file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
1832                                   &bat_priv->nc.max_buffer_time);
1833         if (!file)
1834                 goto out;
1835
1836         return 0;
1837
1838 out:
1839         return -ENOMEM;
1840 }