1 /* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
3 * Martin Hundebøll, Jeppe Ledet-Pedersen
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.
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.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 #include <linux/debugfs.h>
22 #include "network-coding.h"
24 #include "originator.h"
25 #include "hard-interface.h"
28 static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
29 static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
31 static void batadv_nc_worker(struct work_struct *work);
32 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
33 struct batadv_hard_iface *recv_if);
36 * batadv_nc_init - one-time initialization for network coding
38 int __init batadv_nc_init(void)
42 /* Register our packet type */
43 ret = batadv_recv_handler_register(BATADV_CODED,
44 batadv_nc_recv_coded_packet);
50 * batadv_nc_start_timer - initialise the nc periodic worker
51 * @bat_priv: the bat priv with all the soft interface information
53 static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
55 queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
56 msecs_to_jiffies(10));
60 * batadv_nc_tvlv_container_update - update the network coding tvlv container
61 * after network coding setting change
62 * @bat_priv: the bat priv with all the soft interface information
64 static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv)
68 nc_mode = atomic_read(&bat_priv->network_coding);
72 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
75 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1,
82 * batadv_nc_status_update - update the network coding tvlv container after
83 * network coding setting change
84 * @net_dev: the soft interface net device
86 void batadv_nc_status_update(struct net_device *net_dev)
88 struct batadv_priv *bat_priv = netdev_priv(net_dev);
89 batadv_nc_tvlv_container_update(bat_priv);
93 * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
94 * @bat_priv: the bat priv with all the soft interface information
95 * @orig: the orig_node of the ogm
96 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
97 * @tvlv_value: tvlv buffer containing the gateway data
98 * @tvlv_value_len: tvlv buffer length
100 static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
101 struct batadv_orig_node *orig,
104 uint16_t tvlv_value_len)
106 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
107 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC;
109 orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC;
113 * batadv_nc_mesh_init - initialise coding hash table and start house keeping
114 * @bat_priv: the bat priv with all the soft interface information
116 int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
118 bat_priv->nc.timestamp_fwd_flush = jiffies;
119 bat_priv->nc.timestamp_sniffed_purge = jiffies;
121 if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
124 bat_priv->nc.coding_hash = batadv_hash_new(128);
125 if (!bat_priv->nc.coding_hash)
128 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
129 &batadv_nc_coding_hash_lock_class_key);
131 bat_priv->nc.decoding_hash = batadv_hash_new(128);
132 if (!bat_priv->nc.decoding_hash)
135 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
136 &batadv_nc_decoding_hash_lock_class_key);
138 INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
139 batadv_nc_start_timer(bat_priv);
141 batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1,
142 NULL, BATADV_TVLV_NC, 1,
143 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
144 batadv_nc_tvlv_container_update(bat_priv);
152 * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
153 * @bat_priv: the bat priv with all the soft interface information
155 void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
157 atomic_set(&bat_priv->network_coding, 1);
158 bat_priv->nc.min_tq = 200;
159 bat_priv->nc.max_fwd_delay = 10;
160 bat_priv->nc.max_buffer_time = 200;
164 * batadv_nc_init_orig - initialise the nc fields of an orig_node
165 * @orig_node: the orig_node which is going to be initialised
167 void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
169 INIT_LIST_HEAD(&orig_node->in_coding_list);
170 INIT_LIST_HEAD(&orig_node->out_coding_list);
171 spin_lock_init(&orig_node->in_coding_list_lock);
172 spin_lock_init(&orig_node->out_coding_list_lock);
176 * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove
177 * its refcount on the orig_node
178 * @rcu: rcu pointer of the nc node
180 static void batadv_nc_node_free_rcu(struct rcu_head *rcu)
182 struct batadv_nc_node *nc_node;
184 nc_node = container_of(rcu, struct batadv_nc_node, rcu);
185 batadv_orig_node_free_ref(nc_node->orig_node);
190 * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly
192 * @nc_node: the nc node to free
194 static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
196 if (atomic_dec_and_test(&nc_node->refcount))
197 call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu);
201 * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
203 * @nc_path: the nc node to free
205 static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path)
207 if (atomic_dec_and_test(&nc_path->refcount))
208 kfree_rcu(nc_path, rcu);
212 * batadv_nc_packet_free - frees nc packet
213 * @nc_packet: the nc packet to free
215 static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet)
218 kfree_skb(nc_packet->skb);
220 batadv_nc_path_free_ref(nc_packet->nc_path);
225 * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
226 * @bat_priv: the bat priv with all the soft interface information
227 * @nc_node: the nc node to check
229 * Returns true if the entry has to be purged now, false otherwise
231 static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
232 struct batadv_nc_node *nc_node)
234 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
237 return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
241 * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
242 * @bat_priv: the bat priv with all the soft interface information
243 * @nc_path: the nc path to check
245 * Returns true if the entry has to be purged now, false otherwise
247 static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
248 struct batadv_nc_path *nc_path)
250 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
253 /* purge the path when no packets has been added for 10 times the
256 return batadv_has_timed_out(nc_path->last_valid,
257 bat_priv->nc.max_fwd_delay * 10);
261 * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
262 * @bat_priv: the bat priv with all the soft interface information
263 * @nc_path: the nc path to check
265 * Returns true if the entry has to be purged now, false otherwise
267 static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
268 struct batadv_nc_path *nc_path)
270 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
273 /* purge the path when no packets has been added for 10 times the
276 return batadv_has_timed_out(nc_path->last_valid,
277 bat_priv->nc.max_buffer_time*10);
281 * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
283 * @bat_priv: the bat priv with all the soft interface information
284 * @list: list of nc nodes
285 * @lock: nc node list lock
286 * @to_purge: function in charge to decide whether an entry has to be purged or
287 * not. This function takes the nc node as argument and has to return
288 * a boolean value: true if the entry has to be deleted, false
292 batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
293 struct list_head *list,
295 bool (*to_purge)(struct batadv_priv *,
296 struct batadv_nc_node *))
298 struct batadv_nc_node *nc_node, *nc_node_tmp;
300 /* For each nc_node in list */
302 list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
303 /* if an helper function has been passed as parameter,
304 * ask it if the entry has to be purged or not
306 if (to_purge && !to_purge(bat_priv, nc_node))
309 batadv_dbg(BATADV_DBG_NC, bat_priv,
310 "Removing nc_node %pM -> %pM\n",
311 nc_node->addr, nc_node->orig_node->orig);
312 list_del_rcu(&nc_node->list);
313 batadv_nc_node_free_ref(nc_node);
315 spin_unlock_bh(lock);
319 * batadv_nc_purge_orig - purges all nc node data attached of the given
321 * @bat_priv: the bat priv with all the soft interface information
322 * @orig_node: orig_node with the nc node entries to be purged
323 * @to_purge: function in charge to decide whether an entry has to be purged or
324 * not. This function takes the nc node as argument and has to return
325 * a boolean value: true is the entry has to be deleted, false
328 void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
329 struct batadv_orig_node *orig_node,
330 bool (*to_purge)(struct batadv_priv *,
331 struct batadv_nc_node *))
333 /* Check ingoing nc_node's of this orig_node */
334 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
335 &orig_node->in_coding_list_lock,
338 /* Check outgoing nc_node's of this orig_node */
339 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
340 &orig_node->out_coding_list_lock,
345 * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
346 * have timed out nc nodes
347 * @bat_priv: the bat priv with all the soft interface information
349 static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
351 struct batadv_hashtable *hash = bat_priv->orig_hash;
352 struct hlist_head *head;
353 struct batadv_orig_node *orig_node;
359 /* For each orig_node */
360 for (i = 0; i < hash->size; i++) {
361 head = &hash->table[i];
364 hlist_for_each_entry_rcu(orig_node, head, hash_entry)
365 batadv_nc_purge_orig(bat_priv, orig_node,
366 batadv_nc_to_purge_nc_node);
372 * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
374 * @bat_priv: the bat priv with all the soft interface information
375 * @hash: hash table containing the nc paths to check
376 * @to_purge: function in charge to decide whether an entry has to be purged or
377 * not. This function takes the nc node as argument and has to return
378 * a boolean value: true is the entry has to be deleted, false
381 static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,
382 struct batadv_hashtable *hash,
383 bool (*to_purge)(struct batadv_priv *,
384 struct batadv_nc_path *))
386 struct hlist_head *head;
387 struct hlist_node *node_tmp;
388 struct batadv_nc_path *nc_path;
389 spinlock_t *lock; /* Protects lists in hash */
392 for (i = 0; i < hash->size; i++) {
393 head = &hash->table[i];
394 lock = &hash->list_locks[i];
396 /* For each nc_path in this bin */
398 hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) {
399 /* if an helper function has been passed as parameter,
400 * ask it if the entry has to be purged or not
402 if (to_purge && !to_purge(bat_priv, nc_path))
405 /* purging an non-empty nc_path should never happen, but
406 * is observed under high CPU load. Delay the purging
407 * until next iteration to allow the packet_list to be
410 if (!unlikely(list_empty(&nc_path->packet_list))) {
411 net_ratelimited_function(printk,
413 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
419 /* nc_path is unused, so remove it */
420 batadv_dbg(BATADV_DBG_NC, bat_priv,
421 "Remove nc_path %pM -> %pM\n",
422 nc_path->prev_hop, nc_path->next_hop);
423 hlist_del_rcu(&nc_path->hash_entry);
424 batadv_nc_path_free_ref(nc_path);
426 spin_unlock_bh(lock);
431 * batadv_nc_hash_key_gen - computes the nc_path hash key
432 * @key: buffer to hold the final hash key
433 * @src: source ethernet mac address going into the hash key
434 * @dst: destination ethernet mac address going into the hash key
436 static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src,
439 memcpy(key->prev_hop, src, sizeof(key->prev_hop));
440 memcpy(key->next_hop, dst, sizeof(key->next_hop));
444 * batadv_nc_hash_choose - compute the hash value for an nc path
445 * @data: data to hash
446 * @size: size of the hash table
448 * Returns the selected index in the hash table for the given data.
450 static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size)
452 const struct batadv_nc_path *nc_path = data;
455 hash = batadv_hash_bytes(hash, &nc_path->prev_hop,
456 sizeof(nc_path->prev_hop));
457 hash = batadv_hash_bytes(hash, &nc_path->next_hop,
458 sizeof(nc_path->next_hop));
461 hash ^= (hash >> 11);
462 hash += (hash << 15);
468 * batadv_nc_hash_compare - comparing function used in the network coding hash
470 * @node: node in the local table
471 * @data2: second object to compare the node to
473 * Returns 1 if the two entry are the same, 0 otherwise
475 static int batadv_nc_hash_compare(const struct hlist_node *node,
478 const struct batadv_nc_path *nc_path1, *nc_path2;
480 nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
483 /* Return 1 if the two keys are identical */
484 if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop,
485 sizeof(nc_path1->prev_hop)) != 0)
488 if (memcmp(nc_path1->next_hop, nc_path2->next_hop,
489 sizeof(nc_path1->next_hop)) != 0)
496 * batadv_nc_hash_find - search for an existing nc path and return it
497 * @hash: hash table containing the nc path
500 * Returns the nc_path if found, NULL otherwise.
502 static struct batadv_nc_path *
503 batadv_nc_hash_find(struct batadv_hashtable *hash,
506 struct hlist_head *head;
507 struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
513 index = batadv_nc_hash_choose(data, hash->size);
514 head = &hash->table[index];
517 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
518 if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
521 if (!atomic_inc_not_zero(&nc_path->refcount))
524 nc_path_tmp = nc_path;
533 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
534 * @nc_packet: the nc packet to send
536 static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
538 batadv_send_skb_packet(nc_packet->skb,
539 nc_packet->neigh_node->if_incoming,
540 nc_packet->nc_path->next_hop);
541 nc_packet->skb = NULL;
542 batadv_nc_packet_free(nc_packet);
546 * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
547 * @bat_priv: the bat priv with all the soft interface information
548 * @nc_path: the nc path the packet belongs to
549 * @nc_packet: the nc packet to be checked
551 * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
552 * timeout. If so, the packet is no longer kept and the entry deleted from the
553 * queue. Has to be called with the appropriate locks.
555 * Returns false as soon as the entry in the fifo queue has not been timed out
556 * yet and true otherwise.
558 static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
559 struct batadv_nc_path *nc_path,
560 struct batadv_nc_packet *nc_packet)
562 unsigned long timeout = bat_priv->nc.max_buffer_time;
565 /* Packets are added to tail, so the remaining packets did not time
566 * out and we can stop processing the current queue
568 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
569 !batadv_has_timed_out(nc_packet->timestamp, timeout))
572 /* purge nc packet */
573 list_del(&nc_packet->list);
574 batadv_nc_packet_free(nc_packet);
583 * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
584 * @bat_priv: the bat priv with all the soft interface information
585 * @nc_path: the nc path the packet belongs to
586 * @nc_packet: the nc packet to be checked
588 * Checks whether the given nc packet has hit its forward timeout. If so, the
589 * packet is no longer delayed, immediately sent and the entry deleted from the
590 * queue. Has to be called with the appropriate locks.
592 * Returns false as soon as the entry in the fifo queue has not been timed out
593 * yet and true otherwise.
595 static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,
596 struct batadv_nc_path *nc_path,
597 struct batadv_nc_packet *nc_packet)
599 unsigned long timeout = bat_priv->nc.max_fwd_delay;
601 /* Packets are added to tail, so the remaining packets did not time
602 * out and we can stop processing the current queue
604 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
605 !batadv_has_timed_out(nc_packet->timestamp, timeout))
609 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
610 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
611 nc_packet->skb->len + ETH_HLEN);
612 list_del(&nc_packet->list);
613 batadv_nc_send_packet(nc_packet);
619 * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
621 * @bat_priv: the bat priv with all the soft interface information
622 * @hash: to be processed hash table
623 * @process_fn: Function called to process given nc packet. Should return true
624 * to encourage this function to proceed with the next packet.
625 * Otherwise the rest of the current queue is skipped.
628 batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,
629 struct batadv_hashtable *hash,
630 bool (*process_fn)(struct batadv_priv *,
631 struct batadv_nc_path *,
632 struct batadv_nc_packet *))
634 struct hlist_head *head;
635 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
636 struct batadv_nc_path *nc_path;
643 /* Loop hash table bins */
644 for (i = 0; i < hash->size; i++) {
645 head = &hash->table[i];
647 /* Loop coding paths */
649 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
651 spin_lock_bh(&nc_path->packet_list_lock);
652 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
653 &nc_path->packet_list, list) {
654 ret = process_fn(bat_priv, nc_path, nc_packet);
658 spin_unlock_bh(&nc_path->packet_list_lock);
665 * batadv_nc_worker - periodic task for house keeping related to network coding
666 * @work: kernel work struct
668 static void batadv_nc_worker(struct work_struct *work)
670 struct delayed_work *delayed_work;
671 struct batadv_priv_nc *priv_nc;
672 struct batadv_priv *bat_priv;
673 unsigned long timeout;
675 delayed_work = container_of(work, struct delayed_work, work);
676 priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
677 bat_priv = container_of(priv_nc, struct batadv_priv, nc);
679 batadv_nc_purge_orig_hash(bat_priv);
680 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
681 batadv_nc_to_purge_nc_path_coding);
682 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
683 batadv_nc_to_purge_nc_path_decoding);
685 timeout = bat_priv->nc.max_fwd_delay;
687 if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {
688 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
689 batadv_nc_fwd_flush);
690 bat_priv->nc.timestamp_fwd_flush = jiffies;
693 if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
694 bat_priv->nc.max_buffer_time)) {
695 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
696 batadv_nc_sniffed_purge);
697 bat_priv->nc.timestamp_sniffed_purge = jiffies;
700 /* Schedule a new check */
701 batadv_nc_start_timer(bat_priv);
705 * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
707 * @bat_priv: the bat priv with all the soft interface information
708 * @orig_node: neighboring orig node which may be used as nc candidate
709 * @ogm_packet: incoming ogm packet also used for the checks
712 * 1) The OGM must have the most recent sequence number.
713 * 2) The TTL must be decremented by one and only one.
714 * 3) The OGM must be received from the first hop from orig_node.
715 * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
717 static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
718 struct batadv_orig_node *orig_node,
719 struct batadv_ogm_packet *ogm_packet)
721 if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno))
723 if (orig_node->last_ttl != ogm_packet->ttl + 1)
725 if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
727 if (ogm_packet->tq < bat_priv->nc.min_tq)
734 * batadv_nc_find_nc_node - search for an existing nc node and return it
735 * @orig_node: orig node originating the ogm packet
736 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
737 * (can be equal to orig_node)
738 * @in_coding: traverse incoming or outgoing network coding list
740 * Returns the nc_node if found, NULL otherwise.
742 static struct batadv_nc_node
743 *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
744 struct batadv_orig_node *orig_neigh_node,
747 struct batadv_nc_node *nc_node, *nc_node_out = NULL;
748 struct list_head *list;
751 list = &orig_neigh_node->in_coding_list;
753 list = &orig_neigh_node->out_coding_list;
755 /* Traverse list of nc_nodes to orig_node */
757 list_for_each_entry_rcu(nc_node, list, list) {
758 if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
761 if (!atomic_inc_not_zero(&nc_node->refcount))
765 nc_node_out = nc_node;
774 * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
776 * @bat_priv: the bat priv with all the soft interface information
777 * @orig_node: orig node originating the ogm packet
778 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
779 * (can be equal to orig_node)
780 * @in_coding: traverse incoming or outgoing network coding list
782 * Returns the nc_node if found or created, NULL in case of an error.
784 static struct batadv_nc_node
785 *batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
786 struct batadv_orig_node *orig_node,
787 struct batadv_orig_node *orig_neigh_node,
790 struct batadv_nc_node *nc_node;
791 spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
792 struct list_head *list;
794 /* Check if nc_node is already added */
795 nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
801 nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
805 if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
808 /* Initialize nc_node */
809 INIT_LIST_HEAD(&nc_node->list);
810 memcpy(nc_node->addr, orig_node->orig, ETH_ALEN);
811 nc_node->orig_node = orig_neigh_node;
812 atomic_set(&nc_node->refcount, 2);
814 /* Select ingoing or outgoing coding node */
816 lock = &orig_neigh_node->in_coding_list_lock;
817 list = &orig_neigh_node->in_coding_list;
819 lock = &orig_neigh_node->out_coding_list_lock;
820 list = &orig_neigh_node->out_coding_list;
823 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
824 nc_node->addr, nc_node->orig_node->orig);
826 /* Add nc_node to orig_node */
828 list_add_tail_rcu(&nc_node->list, list);
829 spin_unlock_bh(lock);
839 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs
840 * (best called on incoming OGMs)
841 * @bat_priv: the bat priv with all the soft interface information
842 * @orig_node: orig node originating the ogm packet
843 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
844 * (can be equal to orig_node)
845 * @ogm_packet: incoming ogm packet
846 * @is_single_hop_neigh: orig_node is a single hop neighbor
848 void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
849 struct batadv_orig_node *orig_node,
850 struct batadv_orig_node *orig_neigh_node,
851 struct batadv_ogm_packet *ogm_packet,
852 int is_single_hop_neigh)
854 struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL;
856 /* Check if network coding is enabled */
857 if (!atomic_read(&bat_priv->network_coding))
860 /* check if orig node is network coding enabled */
861 if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC))
864 /* accept ogms from 'good' neighbors and single hop neighbors */
865 if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
866 !is_single_hop_neigh)
869 /* Add orig_node as in_nc_node on hop */
870 in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
871 orig_neigh_node, true);
875 in_nc_node->last_seen = jiffies;
877 /* Add hop as out_nc_node on orig_node */
878 out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
883 out_nc_node->last_seen = jiffies;
887 batadv_nc_node_free_ref(in_nc_node);
889 batadv_nc_node_free_ref(out_nc_node);
893 * batadv_nc_get_path - get existing nc_path or allocate a new one
894 * @bat_priv: the bat priv with all the soft interface information
895 * @hash: hash table containing the nc path
896 * @src: ethernet source address - first half of the nc path search key
897 * @dst: ethernet destination address - second half of the nc path search key
899 * Returns pointer to nc_path if the path was found or created, returns NULL
902 static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
903 struct batadv_hashtable *hash,
908 struct batadv_nc_path *nc_path, nc_path_key;
910 batadv_nc_hash_key_gen(&nc_path_key, src, dst);
912 /* Search for existing nc_path */
913 nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
916 /* Set timestamp to delay removal of nc_path */
917 nc_path->last_valid = jiffies;
921 /* No existing nc_path was found; create a new */
922 nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
927 /* Initialize nc_path */
928 INIT_LIST_HEAD(&nc_path->packet_list);
929 spin_lock_init(&nc_path->packet_list_lock);
930 atomic_set(&nc_path->refcount, 2);
931 nc_path->last_valid = jiffies;
932 memcpy(nc_path->next_hop, dst, ETH_ALEN);
933 memcpy(nc_path->prev_hop, src, ETH_ALEN);
935 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",
939 /* Add nc_path to hash table */
940 hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,
941 batadv_nc_hash_choose, &nc_path_key,
942 &nc_path->hash_entry);
944 if (hash_added < 0) {
953 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
954 * selection of a receiver with slightly lower TQ than the other
955 * @tq: to be weighted tq value
957 static uint8_t batadv_nc_random_weight_tq(uint8_t tq)
959 uint8_t rand_val, rand_tq;
961 get_random_bytes(&rand_val, sizeof(rand_val));
963 /* randomize the estimated packet loss (max TQ - estimated TQ) */
964 rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
966 /* normalize the randomized packet loss */
967 rand_tq /= BATADV_TQ_MAX_VALUE;
969 /* convert to (randomized) estimated tq again */
970 return BATADV_TQ_MAX_VALUE - rand_tq;
974 * batadv_nc_memxor - XOR destination with source
975 * @dst: byte array to XOR into
976 * @src: byte array to XOR from
977 * @len: length of destination array
979 static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
983 for (i = 0; i < len; ++i)
988 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
989 * into a coded_packet and send it
990 * @bat_priv: the bat priv with all the soft interface information
991 * @skb: data skb to forward
992 * @ethhdr: pointer to the ethernet header inside the skb
993 * @nc_packet: structure containing the packet to the skb can be coded with
994 * @neigh_node: next hop to forward packet to
996 * Returns true if both packets are consumed, false otherwise.
998 static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
1000 struct ethhdr *ethhdr,
1001 struct batadv_nc_packet *nc_packet,
1002 struct batadv_neigh_node *neigh_node)
1004 uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp;
1005 struct sk_buff *skb_dest, *skb_src;
1006 struct batadv_unicast_packet *packet1;
1007 struct batadv_unicast_packet *packet2;
1008 struct batadv_coded_packet *coded_packet;
1009 struct batadv_neigh_node *neigh_tmp, *router_neigh;
1010 struct batadv_neigh_node *router_coding = NULL;
1011 uint8_t *first_source, *first_dest, *second_source, *second_dest;
1012 __be32 packet_id1, packet_id2;
1016 int unicast_size = sizeof(*packet1);
1017 int coded_size = sizeof(*coded_packet);
1018 int header_add = coded_size - unicast_size;
1020 router_neigh = batadv_orig_node_get_router(neigh_node->orig_node);
1024 neigh_tmp = nc_packet->neigh_node;
1025 router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node);
1029 tq_tmp = batadv_nc_random_weight_tq(router_neigh->bat_iv.tq_avg);
1030 tq_weighted_neigh = tq_tmp;
1031 tq_tmp = batadv_nc_random_weight_tq(router_coding->bat_iv.tq_avg);
1032 tq_weighted_coding = tq_tmp;
1034 /* Select one destination for the MAC-header dst-field based on
1035 * weighted TQ-values.
1037 if (tq_weighted_neigh >= tq_weighted_coding) {
1038 /* Destination from nc_packet is selected for MAC-header */
1039 first_dest = nc_packet->nc_path->next_hop;
1040 first_source = nc_packet->nc_path->prev_hop;
1041 second_dest = neigh_node->addr;
1042 second_source = ethhdr->h_source;
1043 packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1044 packet2 = (struct batadv_unicast_packet *)skb->data;
1045 packet_id1 = nc_packet->packet_id;
1046 packet_id2 = batadv_skb_crc32(skb,
1047 skb->data + sizeof(*packet2));
1049 /* Destination for skb is selected for MAC-header */
1050 first_dest = neigh_node->addr;
1051 first_source = ethhdr->h_source;
1052 second_dest = nc_packet->nc_path->next_hop;
1053 second_source = nc_packet->nc_path->prev_hop;
1054 packet1 = (struct batadv_unicast_packet *)skb->data;
1055 packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1056 packet_id1 = batadv_skb_crc32(skb,
1057 skb->data + sizeof(*packet1));
1058 packet_id2 = nc_packet->packet_id;
1061 /* Instead of zero padding the smallest data buffer, we
1062 * code into the largest.
1064 if (skb->len <= nc_packet->skb->len) {
1065 skb_dest = nc_packet->skb;
1069 skb_src = nc_packet->skb;
1072 /* coding_len is used when decoding the packet shorter packet */
1073 coding_len = skb_src->len - unicast_size;
1075 if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
1078 skb_push(skb_dest, header_add);
1080 coded_packet = (struct batadv_coded_packet *)skb_dest->data;
1081 skb_reset_mac_header(skb_dest);
1083 coded_packet->packet_type = BATADV_CODED;
1084 coded_packet->version = BATADV_COMPAT_VERSION;
1085 coded_packet->ttl = packet1->ttl;
1087 /* Info about first unicast packet */
1088 memcpy(coded_packet->first_source, first_source, ETH_ALEN);
1089 memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN);
1090 coded_packet->first_crc = packet_id1;
1091 coded_packet->first_ttvn = packet1->ttvn;
1093 /* Info about second unicast packet */
1094 memcpy(coded_packet->second_dest, second_dest, ETH_ALEN);
1095 memcpy(coded_packet->second_source, second_source, ETH_ALEN);
1096 memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN);
1097 coded_packet->second_crc = packet_id2;
1098 coded_packet->second_ttl = packet2->ttl;
1099 coded_packet->second_ttvn = packet2->ttvn;
1100 coded_packet->coded_len = htons(coding_len);
1102 /* This is where the magic happens: Code skb_src into skb_dest */
1103 batadv_nc_memxor(skb_dest->data + coded_size,
1104 skb_src->data + unicast_size, coding_len);
1106 /* Update counters accordingly */
1107 if (BATADV_SKB_CB(skb_src)->decoded &&
1108 BATADV_SKB_CB(skb_dest)->decoded) {
1109 /* Both packets are recoded */
1110 count = skb_src->len + ETH_HLEN;
1111 count += skb_dest->len + ETH_HLEN;
1112 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
1113 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
1114 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1115 !BATADV_SKB_CB(skb_dest)->decoded) {
1116 /* Both packets are newly coded */
1117 count = skb_src->len + ETH_HLEN;
1118 count += skb_dest->len + ETH_HLEN;
1119 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
1120 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
1121 } else if (BATADV_SKB_CB(skb_src)->decoded &&
1122 !BATADV_SKB_CB(skb_dest)->decoded) {
1123 /* skb_src recoded and skb_dest is newly coded */
1124 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1125 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1126 skb_src->len + ETH_HLEN);
1127 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1128 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1129 skb_dest->len + ETH_HLEN);
1130 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1131 BATADV_SKB_CB(skb_dest)->decoded) {
1132 /* skb_src is newly coded and skb_dest is recoded */
1133 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1134 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1135 skb_src->len + ETH_HLEN);
1136 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1137 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1138 skb_dest->len + ETH_HLEN);
1141 /* skb_src is now coded into skb_dest, so free it */
1144 /* avoid duplicate free of skb from nc_packet */
1145 nc_packet->skb = NULL;
1146 batadv_nc_packet_free(nc_packet);
1148 /* Send the coded packet and return true */
1149 batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
1153 batadv_neigh_node_free_ref(router_neigh);
1155 batadv_neigh_node_free_ref(router_coding);
1160 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1161 * @skb: data skb to forward
1162 * @dst: destination mac address of the other skb to code with
1163 * @src: source mac address of skb
1165 * Whenever we network code a packet we have to check whether we received it in
1166 * a network coded form. If so, we may not be able to use it for coding because
1167 * some neighbors may also have received (overheard) the packet in the network
1168 * coded form without being able to decode it. It is hard to know which of the
1169 * neighboring nodes was able to decode the packet, therefore we can only
1170 * re-code the packet if the source of the previous encoded packet is involved.
1171 * Since the source encoded the packet we can be certain it has all necessary
1172 * decode information.
1174 * Returns true if coding of a decoded packet is allowed.
1176 static bool batadv_nc_skb_coding_possible(struct sk_buff *skb,
1177 uint8_t *dst, uint8_t *src)
1179 if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
1186 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1187 * out_nc_node to retrieve a buffered packet that can be used for coding.
1188 * @bat_priv: the bat priv with all the soft interface information
1189 * @in_nc_node: pointer to skb next hop's neighbor nc node
1190 * @out_nc_node: pointer to skb source's neighbor nc node
1191 * @skb: data skb to forward
1192 * @eth_dst: next hop mac address of skb
1194 * Returns true if coding of a decoded skb is allowed.
1196 static struct batadv_nc_packet *
1197 batadv_nc_path_search(struct batadv_priv *bat_priv,
1198 struct batadv_nc_node *in_nc_node,
1199 struct batadv_nc_node *out_nc_node,
1200 struct sk_buff *skb,
1203 struct batadv_nc_path *nc_path, nc_path_key;
1204 struct batadv_nc_packet *nc_packet_out = NULL;
1205 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
1206 struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
1212 /* Create almost path key */
1213 batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
1215 idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
1217 /* Check for coding opportunities in this nc_path */
1219 hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
1220 if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
1223 if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
1226 spin_lock_bh(&nc_path->packet_list_lock);
1227 if (list_empty(&nc_path->packet_list)) {
1228 spin_unlock_bh(&nc_path->packet_list_lock);
1232 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
1233 &nc_path->packet_list, list) {
1234 if (!batadv_nc_skb_coding_possible(nc_packet->skb,
1239 /* Coding opportunity is found! */
1240 list_del(&nc_packet->list);
1241 nc_packet_out = nc_packet;
1245 spin_unlock_bh(&nc_path->packet_list_lock);
1250 return nc_packet_out;
1254 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1255 * skb's sender (may be equal to the originator).
1256 * @bat_priv: the bat priv with all the soft interface information
1257 * @skb: data skb to forward
1258 * @eth_dst: next hop mac address of skb
1259 * @eth_src: source mac address of skb
1260 * @in_nc_node: pointer to skb next hop's neighbor nc node
1262 * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
1264 static struct batadv_nc_packet *
1265 batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
1266 struct sk_buff *skb,
1269 struct batadv_nc_node *in_nc_node)
1271 struct batadv_orig_node *orig_node;
1272 struct batadv_nc_node *out_nc_node;
1273 struct batadv_nc_packet *nc_packet = NULL;
1275 orig_node = batadv_orig_hash_find(bat_priv, eth_src);
1280 list_for_each_entry_rcu(out_nc_node,
1281 &orig_node->out_coding_list, list) {
1282 /* Check if the skb is decoded and if recoding is possible */
1283 if (!batadv_nc_skb_coding_possible(skb,
1284 out_nc_node->addr, eth_src))
1287 /* Search for an opportunity in this nc_path */
1288 nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
1289 out_nc_node, skb, eth_dst);
1295 batadv_orig_node_free_ref(orig_node);
1300 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1301 * unicast skb before it is stored for use in later decoding
1302 * @bat_priv: the bat priv with all the soft interface information
1303 * @skb: data skb to store
1304 * @eth_dst_new: new destination mac address of skb
1306 static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
1307 struct sk_buff *skb,
1308 uint8_t *eth_dst_new)
1310 struct ethhdr *ethhdr;
1312 /* Copy skb header to change the mac header */
1313 skb = pskb_copy(skb, GFP_ATOMIC);
1317 /* Set the mac header as if we actually sent the packet uncoded */
1318 ethhdr = eth_hdr(skb);
1319 memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN);
1320 memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN);
1322 /* Set data pointer to MAC header to mimic packets from our tx path */
1323 skb_push(skb, ETH_HLEN);
1325 /* Add the packet to the decoding packet pool */
1326 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1328 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1335 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1336 * @skb: data skb to forward
1337 * @neigh_node: next hop to forward packet to
1338 * @ethhdr: pointer to the ethernet header inside the skb
1340 * Loops through list of neighboring nodes the next hop has a good connection to
1341 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1342 * next hop that potentially sent a packet which our next hop also received
1343 * (overheard) and has stored for later decoding.
1345 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1347 static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
1348 struct batadv_neigh_node *neigh_node,
1349 struct ethhdr *ethhdr)
1351 struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1352 struct batadv_priv *bat_priv = netdev_priv(netdev);
1353 struct batadv_orig_node *orig_node = neigh_node->orig_node;
1354 struct batadv_nc_node *nc_node;
1355 struct batadv_nc_packet *nc_packet = NULL;
1358 list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
1359 /* Search for coding opportunity with this in_nc_node */
1360 nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
1362 ethhdr->h_source, nc_node);
1364 /* Opportunity was found, so stop searching */
1373 /* Save packets for later decoding */
1374 batadv_nc_skb_store_before_coding(bat_priv, skb,
1376 batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
1377 nc_packet->neigh_node->addr);
1379 /* Code and send packets */
1380 if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
1384 /* out of mem ? Coding failed - we have to free the buffered packet
1385 * to avoid memleaks. The skb passed as argument will be dealt with
1386 * by the calling function.
1388 batadv_nc_send_packet(nc_packet);
1393 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1394 * @skb: skb to add to path
1395 * @nc_path: path to add skb to
1396 * @neigh_node: next hop to forward packet to
1397 * @packet_id: checksum to identify packet
1399 * Returns true if the packet was buffered or false in case of an error.
1401 static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,
1402 struct batadv_nc_path *nc_path,
1403 struct batadv_neigh_node *neigh_node,
1406 struct batadv_nc_packet *nc_packet;
1408 nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
1412 /* Initialize nc_packet */
1413 nc_packet->timestamp = jiffies;
1414 nc_packet->packet_id = packet_id;
1415 nc_packet->skb = skb;
1416 nc_packet->neigh_node = neigh_node;
1417 nc_packet->nc_path = nc_path;
1419 /* Add coding packet to list */
1420 spin_lock_bh(&nc_path->packet_list_lock);
1421 list_add_tail(&nc_packet->list, &nc_path->packet_list);
1422 spin_unlock_bh(&nc_path->packet_list_lock);
1428 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1430 * @skb: data skb to forward
1431 * @neigh_node: next hop to forward packet to
1433 * Returns true if the skb was consumed (encoded packet sent) or false otherwise
1435 bool batadv_nc_skb_forward(struct sk_buff *skb,
1436 struct batadv_neigh_node *neigh_node)
1438 const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1439 struct batadv_priv *bat_priv = netdev_priv(netdev);
1440 struct batadv_unicast_packet *packet;
1441 struct batadv_nc_path *nc_path;
1442 struct ethhdr *ethhdr = eth_hdr(skb);
1446 /* Check if network coding is enabled */
1447 if (!atomic_read(&bat_priv->network_coding))
1450 /* We only handle unicast packets */
1451 payload = skb_network_header(skb);
1452 packet = (struct batadv_unicast_packet *)payload;
1453 if (packet->packet_type != BATADV_UNICAST)
1456 /* Try to find a coding opportunity and send the skb if one is found */
1457 if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
1460 /* Find or create a nc_path for this src-dst pair */
1461 nc_path = batadv_nc_get_path(bat_priv,
1462 bat_priv->nc.coding_hash,
1469 /* Add skb to nc_path */
1470 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1471 if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))
1474 /* Packet is consumed */
1478 batadv_nc_path_free_ref(nc_path);
1480 /* Packet is not consumed */
1485 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1486 * when decoding coded packets
1487 * @bat_priv: the bat priv with all the soft interface information
1488 * @skb: data skb to store
1490 void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
1491 struct sk_buff *skb)
1493 struct batadv_unicast_packet *packet;
1494 struct batadv_nc_path *nc_path;
1495 struct ethhdr *ethhdr = eth_hdr(skb);
1499 /* Check if network coding is enabled */
1500 if (!atomic_read(&bat_priv->network_coding))
1503 /* Check for supported packet type */
1504 payload = skb_network_header(skb);
1505 packet = (struct batadv_unicast_packet *)payload;
1506 if (packet->packet_type != BATADV_UNICAST)
1509 /* Find existing nc_path or create a new */
1510 nc_path = batadv_nc_get_path(bat_priv,
1511 bat_priv->nc.decoding_hash,
1518 /* Clone skb and adjust skb->data to point at batman header */
1519 skb = skb_clone(skb, GFP_ATOMIC);
1523 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
1526 if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
1529 /* Add skb to nc_path */
1530 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1531 if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
1534 batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
1540 batadv_nc_path_free_ref(nc_path);
1546 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1547 * should be saved in the decoding buffer and, if so, store it there
1548 * @bat_priv: the bat priv with all the soft interface information
1549 * @skb: unicast skb to store
1551 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
1552 struct sk_buff *skb)
1554 struct ethhdr *ethhdr = eth_hdr(skb);
1556 if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
1559 /* Set data pointer to MAC header to mimic packets from our tx path */
1560 skb_push(skb, ETH_HLEN);
1562 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1566 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1568 * @bat_priv: the bat priv with all the soft interface information
1569 * @skb: unicast skb to decode
1570 * @nc_packet: decode data needed to decode the skb
1572 * Returns pointer to decoded unicast packet if the packet was decoded or NULL
1573 * in case of an error.
1575 static struct batadv_unicast_packet *
1576 batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
1577 struct batadv_nc_packet *nc_packet)
1579 const int h_size = sizeof(struct batadv_unicast_packet);
1580 const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
1581 struct batadv_unicast_packet *unicast_packet;
1582 struct batadv_coded_packet coded_packet_tmp;
1583 struct ethhdr *ethhdr, ethhdr_tmp;
1584 uint8_t *orig_dest, ttl, ttvn;
1585 unsigned int coding_len;
1588 /* Save headers temporarily */
1589 memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
1590 memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
1592 if (skb_cow(skb, 0) < 0)
1595 if (unlikely(!skb_pull_rcsum(skb, h_diff)))
1598 /* Data points to batman header, so set mac header 14 bytes before
1599 * and network to data
1601 skb_set_mac_header(skb, -ETH_HLEN);
1602 skb_reset_network_header(skb);
1604 /* Reconstruct original mac header */
1605 ethhdr = eth_hdr(skb);
1606 memcpy(ethhdr, ðhdr_tmp, sizeof(*ethhdr));
1608 /* Select the correct unicast header information based on the location
1609 * of our mac address in the coded_packet header
1611 if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
1612 /* If we are the second destination the packet was overheard,
1613 * so the Ethernet address must be copied to h_dest and
1614 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1616 memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN);
1617 skb->pkt_type = PACKET_HOST;
1619 orig_dest = coded_packet_tmp.second_orig_dest;
1620 ttl = coded_packet_tmp.second_ttl;
1621 ttvn = coded_packet_tmp.second_ttvn;
1623 orig_dest = coded_packet_tmp.first_orig_dest;
1624 ttl = coded_packet_tmp.ttl;
1625 ttvn = coded_packet_tmp.first_ttvn;
1628 coding_len = ntohs(coded_packet_tmp.coded_len);
1630 if (coding_len > skb->len)
1633 /* Here the magic is reversed:
1634 * extract the missing packet from the received coded packet
1636 batadv_nc_memxor(skb->data + h_size,
1637 nc_packet->skb->data + h_size,
1640 /* Resize decoded skb if decoded with larger packet */
1641 if (nc_packet->skb->len > coding_len + h_size) {
1642 err = pskb_trim_rcsum(skb, coding_len + h_size);
1647 /* Create decoded unicast packet */
1648 unicast_packet = (struct batadv_unicast_packet *)skb->data;
1649 unicast_packet->packet_type = BATADV_UNICAST;
1650 unicast_packet->version = BATADV_COMPAT_VERSION;
1651 unicast_packet->ttl = ttl;
1652 memcpy(unicast_packet->dest, orig_dest, ETH_ALEN);
1653 unicast_packet->ttvn = ttvn;
1655 batadv_nc_packet_free(nc_packet);
1656 return unicast_packet;
1660 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1661 * find the data needed to decode the coded packet
1662 * @bat_priv: the bat priv with all the soft interface information
1663 * @ethhdr: pointer to the ethernet header inside the coded packet
1664 * @coded: coded packet we try to find decode data for
1666 * Returns pointer to nc packet if the needed data was found or NULL otherwise.
1668 static struct batadv_nc_packet *
1669 batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
1670 struct ethhdr *ethhdr,
1671 struct batadv_coded_packet *coded)
1673 struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
1674 struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
1675 struct batadv_nc_path *nc_path, nc_path_key;
1676 uint8_t *dest, *source;
1683 /* Select the correct packet id based on the location of our mac-addr */
1684 dest = ethhdr->h_source;
1685 if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
1686 source = coded->second_source;
1687 packet_id = coded->second_crc;
1689 source = coded->first_source;
1690 packet_id = coded->first_crc;
1693 batadv_nc_hash_key_gen(&nc_path_key, source, dest);
1694 index = batadv_nc_hash_choose(&nc_path_key, hash->size);
1696 /* Search for matching coding path */
1698 hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
1699 /* Find matching nc_packet */
1700 spin_lock_bh(&nc_path->packet_list_lock);
1701 list_for_each_entry(tmp_nc_packet,
1702 &nc_path->packet_list, list) {
1703 if (packet_id == tmp_nc_packet->packet_id) {
1704 list_del(&tmp_nc_packet->list);
1706 nc_packet = tmp_nc_packet;
1710 spin_unlock_bh(&nc_path->packet_list_lock);
1718 batadv_dbg(BATADV_DBG_NC, bat_priv,
1719 "No decoding packet found for %u\n", packet_id);
1725 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1726 * resulting unicast packet
1727 * @skb: incoming coded packet
1728 * @recv_if: pointer to interface this packet was received on
1730 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
1731 struct batadv_hard_iface *recv_if)
1733 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1734 struct batadv_unicast_packet *unicast_packet;
1735 struct batadv_coded_packet *coded_packet;
1736 struct batadv_nc_packet *nc_packet;
1737 struct ethhdr *ethhdr;
1738 int hdr_size = sizeof(*coded_packet);
1740 /* Check if network coding is enabled */
1741 if (!atomic_read(&bat_priv->network_coding))
1744 /* Make sure we can access (and remove) header */
1745 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1748 coded_packet = (struct batadv_coded_packet *)skb->data;
1749 ethhdr = eth_hdr(skb);
1751 /* Verify frame is destined for us */
1752 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
1753 !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1756 /* Update stat counter */
1757 if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1758 batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
1760 nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
1763 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1767 /* Make skb's linear, because decoding accesses the entire buffer */
1768 if (skb_linearize(skb) < 0)
1769 goto free_nc_packet;
1771 if (skb_linearize(nc_packet->skb) < 0)
1772 goto free_nc_packet;
1774 /* Decode the packet */
1775 unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
1776 if (!unicast_packet) {
1777 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1778 goto free_nc_packet;
1781 /* Mark packet as decoded to do correct recoding when forwarding */
1782 BATADV_SKB_CB(skb)->decoded = true;
1783 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
1784 batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
1785 skb->len + ETH_HLEN);
1786 return batadv_recv_unicast_packet(skb, recv_if);
1789 batadv_nc_packet_free(nc_packet);
1794 * batadv_nc_mesh_free - clean up network coding memory
1795 * @bat_priv: the bat priv with all the soft interface information
1797 void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
1799 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
1800 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1);
1801 cancel_delayed_work_sync(&bat_priv->nc.work);
1803 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
1804 batadv_hash_destroy(bat_priv->nc.coding_hash);
1805 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
1806 batadv_hash_destroy(bat_priv->nc.decoding_hash);
1810 * batadv_nc_nodes_seq_print_text - print the nc node information
1811 * @seq: seq file to print on
1814 int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
1816 struct net_device *net_dev = (struct net_device *)seq->private;
1817 struct batadv_priv *bat_priv = netdev_priv(net_dev);
1818 struct batadv_hashtable *hash = bat_priv->orig_hash;
1819 struct batadv_hard_iface *primary_if;
1820 struct hlist_head *head;
1821 struct batadv_orig_node *orig_node;
1822 struct batadv_nc_node *nc_node;
1825 primary_if = batadv_seq_print_text_primary_if_get(seq);
1829 /* Traverse list of originators */
1830 for (i = 0; i < hash->size; i++) {
1831 head = &hash->table[i];
1833 /* For each orig_node in this bin */
1835 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1836 /* no need to print the orig node if it does not have
1837 * network coding neighbors
1839 if (list_empty(&orig_node->in_coding_list) &&
1840 list_empty(&orig_node->out_coding_list))
1843 seq_printf(seq, "Node: %pM\n", orig_node->orig);
1845 seq_puts(seq, " Ingoing: ");
1846 /* For each in_nc_node to this orig_node */
1847 list_for_each_entry_rcu(nc_node,
1848 &orig_node->in_coding_list,
1850 seq_printf(seq, "%pM ",
1852 seq_puts(seq, "\n");
1854 seq_puts(seq, " Outgoing: ");
1855 /* For out_nc_node to this orig_node */
1856 list_for_each_entry_rcu(nc_node,
1857 &orig_node->out_coding_list,
1859 seq_printf(seq, "%pM ",
1861 seq_puts(seq, "\n\n");
1868 batadv_hardif_free_ref(primary_if);
1873 * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1874 * @bat_priv: the bat priv with all the soft interface information
1876 int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
1878 struct dentry *nc_dir, *file;
1880 nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
1884 file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
1885 &bat_priv->nc.min_tq);
1889 file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,
1890 &bat_priv->nc.max_fwd_delay);
1894 file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
1895 &bat_priv->nc.max_buffer_time);