1 /* Copyright (C) 2012-2016 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 "network-coding.h"
21 #include <linux/atomic.h>
22 #include <linux/bitops.h>
23 #include <linux/byteorder/generic.h>
24 #include <linux/compiler.h>
25 #include <linux/debugfs.h>
26 #include <linux/errno.h>
27 #include <linux/etherdevice.h>
29 #include <linux/if_ether.h>
30 #include <linux/if_packet.h>
31 #include <linux/init.h>
32 #include <linux/jhash.h>
33 #include <linux/jiffies.h>
34 #include <linux/kernel.h>
35 #include <linux/kref.h>
36 #include <linux/list.h>
37 #include <linux/lockdep.h>
38 #include <linux/netdevice.h>
39 #include <linux/printk.h>
40 #include <linux/random.h>
41 #include <linux/rculist.h>
42 #include <linux/rcupdate.h>
43 #include <linux/seq_file.h>
44 #include <linux/skbuff.h>
45 #include <linux/slab.h>
46 #include <linux/spinlock.h>
47 #include <linux/stat.h>
48 #include <linux/stddef.h>
49 #include <linux/string.h>
50 #include <linux/workqueue.h>
52 #include "hard-interface.h"
55 #include "originator.h"
61 static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
62 static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
64 static void batadv_nc_worker(struct work_struct *work);
65 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
66 struct batadv_hard_iface *recv_if);
69 * batadv_nc_init - one-time initialization for network coding
71 * Return: 0 on success or negative error number in case of failure
73 int __init batadv_nc_init(void)
77 /* Register our packet type */
78 ret = batadv_recv_handler_register(BATADV_CODED,
79 batadv_nc_recv_coded_packet);
85 * batadv_nc_start_timer - initialise the nc periodic worker
86 * @bat_priv: the bat priv with all the soft interface information
88 static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
90 queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
91 msecs_to_jiffies(10));
95 * batadv_nc_tvlv_container_update - update the network coding tvlv container
96 * after network coding setting change
97 * @bat_priv: the bat priv with all the soft interface information
99 static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv)
103 nc_mode = atomic_read(&bat_priv->network_coding);
107 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
110 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1,
117 * batadv_nc_status_update - update the network coding tvlv container after
118 * network coding setting change
119 * @net_dev: the soft interface net device
121 void batadv_nc_status_update(struct net_device *net_dev)
123 struct batadv_priv *bat_priv = netdev_priv(net_dev);
125 batadv_nc_tvlv_container_update(bat_priv);
129 * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
130 * @bat_priv: the bat priv with all the soft interface information
131 * @orig: the orig_node of the ogm
132 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
133 * @tvlv_value: tvlv buffer containing the gateway data
134 * @tvlv_value_len: tvlv buffer length
136 static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
137 struct batadv_orig_node *orig,
139 void *tvlv_value, u16 tvlv_value_len)
141 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
142 clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
144 set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
148 * batadv_nc_mesh_init - initialise coding hash table and start house keeping
149 * @bat_priv: the bat priv with all the soft interface information
151 * Return: 0 on success or negative error number in case of failure
153 int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
155 bat_priv->nc.timestamp_fwd_flush = jiffies;
156 bat_priv->nc.timestamp_sniffed_purge = jiffies;
158 if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
161 bat_priv->nc.coding_hash = batadv_hash_new(128);
162 if (!bat_priv->nc.coding_hash)
165 batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
166 &batadv_nc_coding_hash_lock_class_key);
168 bat_priv->nc.decoding_hash = batadv_hash_new(128);
169 if (!bat_priv->nc.decoding_hash) {
170 batadv_hash_destroy(bat_priv->nc.coding_hash);
174 batadv_hash_set_lock_class(bat_priv->nc.decoding_hash,
175 &batadv_nc_decoding_hash_lock_class_key);
177 INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
178 batadv_nc_start_timer(bat_priv);
180 batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1,
181 NULL, BATADV_TVLV_NC, 1,
182 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
183 batadv_nc_tvlv_container_update(bat_priv);
191 * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
192 * @bat_priv: the bat priv with all the soft interface information
194 void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
196 atomic_set(&bat_priv->network_coding, 0);
197 bat_priv->nc.min_tq = 200;
198 bat_priv->nc.max_fwd_delay = 10;
199 bat_priv->nc.max_buffer_time = 200;
203 * batadv_nc_init_orig - initialise the nc fields of an orig_node
204 * @orig_node: the orig_node which is going to be initialised
206 void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
208 INIT_LIST_HEAD(&orig_node->in_coding_list);
209 INIT_LIST_HEAD(&orig_node->out_coding_list);
210 spin_lock_init(&orig_node->in_coding_list_lock);
211 spin_lock_init(&orig_node->out_coding_list_lock);
215 * batadv_nc_node_release - release nc_node from lists and queue for free after
217 * @ref: kref pointer of the nc_node
219 static void batadv_nc_node_release(struct kref *ref)
221 struct batadv_nc_node *nc_node;
223 nc_node = container_of(ref, struct batadv_nc_node, refcount);
225 batadv_orig_node_put(nc_node->orig_node);
226 kfree_rcu(nc_node, rcu);
230 * batadv_nc_node_put - decrement the nc_node refcounter and possibly
232 * @nc_node: nc_node to be free'd
234 static void batadv_nc_node_put(struct batadv_nc_node *nc_node)
236 kref_put(&nc_node->refcount, batadv_nc_node_release);
240 * batadv_nc_path_release - release nc_path from lists and queue for free after
242 * @ref: kref pointer of the nc_path
244 static void batadv_nc_path_release(struct kref *ref)
246 struct batadv_nc_path *nc_path;
248 nc_path = container_of(ref, struct batadv_nc_path, refcount);
250 kfree_rcu(nc_path, rcu);
254 * batadv_nc_path_put - decrement the nc_path refcounter and possibly
256 * @nc_path: nc_path to be free'd
258 static void batadv_nc_path_put(struct batadv_nc_path *nc_path)
260 kref_put(&nc_path->refcount, batadv_nc_path_release);
264 * batadv_nc_packet_free - frees nc packet
265 * @nc_packet: the nc packet to free
267 static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet)
269 kfree_skb(nc_packet->skb);
270 batadv_nc_path_put(nc_packet->nc_path);
275 * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
276 * @bat_priv: the bat priv with all the soft interface information
277 * @nc_node: the nc node to check
279 * Return: true if the entry has to be purged now, false otherwise
281 static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
282 struct batadv_nc_node *nc_node)
284 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
287 return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
291 * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
292 * @bat_priv: the bat priv with all the soft interface information
293 * @nc_path: the nc path to check
295 * Return: true if the entry has to be purged now, false otherwise
297 static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
298 struct batadv_nc_path *nc_path)
300 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
303 /* purge the path when no packets has been added for 10 times the
306 return batadv_has_timed_out(nc_path->last_valid,
307 bat_priv->nc.max_fwd_delay * 10);
311 * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
312 * @bat_priv: the bat priv with all the soft interface information
313 * @nc_path: the nc path to check
315 * Return: true if the entry has to be purged now, false otherwise
317 static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
318 struct batadv_nc_path *nc_path)
320 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
323 /* purge the path when no packets has been added for 10 times the
326 return batadv_has_timed_out(nc_path->last_valid,
327 bat_priv->nc.max_buffer_time * 10);
331 * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
333 * @bat_priv: the bat priv with all the soft interface information
334 * @list: list of nc nodes
335 * @lock: nc node list lock
336 * @to_purge: function in charge to decide whether an entry has to be purged or
337 * not. This function takes the nc node as argument and has to return
338 * a boolean value: true if the entry has to be deleted, false
342 batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
343 struct list_head *list,
345 bool (*to_purge)(struct batadv_priv *,
346 struct batadv_nc_node *))
348 struct batadv_nc_node *nc_node, *nc_node_tmp;
350 /* For each nc_node in list */
352 list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
353 /* if an helper function has been passed as parameter,
354 * ask it if the entry has to be purged or not
356 if (to_purge && !to_purge(bat_priv, nc_node))
359 batadv_dbg(BATADV_DBG_NC, bat_priv,
360 "Removing nc_node %pM -> %pM\n",
361 nc_node->addr, nc_node->orig_node->orig);
362 list_del_rcu(&nc_node->list);
363 batadv_nc_node_put(nc_node);
365 spin_unlock_bh(lock);
369 * batadv_nc_purge_orig - purges all nc node data attached of the given
371 * @bat_priv: the bat priv with all the soft interface information
372 * @orig_node: orig_node with the nc node entries to be purged
373 * @to_purge: function in charge to decide whether an entry has to be purged or
374 * not. This function takes the nc node as argument and has to return
375 * a boolean value: true is the entry has to be deleted, false
378 void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
379 struct batadv_orig_node *orig_node,
380 bool (*to_purge)(struct batadv_priv *,
381 struct batadv_nc_node *))
383 /* Check ingoing nc_node's of this orig_node */
384 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
385 &orig_node->in_coding_list_lock,
388 /* Check outgoing nc_node's of this orig_node */
389 batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
390 &orig_node->out_coding_list_lock,
395 * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
396 * have timed out nc nodes
397 * @bat_priv: the bat priv with all the soft interface information
399 static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
401 struct batadv_hashtable *hash = bat_priv->orig_hash;
402 struct hlist_head *head;
403 struct batadv_orig_node *orig_node;
409 /* For each orig_node */
410 for (i = 0; i < hash->size; i++) {
411 head = &hash->table[i];
414 hlist_for_each_entry_rcu(orig_node, head, hash_entry)
415 batadv_nc_purge_orig(bat_priv, orig_node,
416 batadv_nc_to_purge_nc_node);
422 * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
424 * @bat_priv: the bat priv with all the soft interface information
425 * @hash: hash table containing the nc paths to check
426 * @to_purge: function in charge to decide whether an entry has to be purged or
427 * not. This function takes the nc node as argument and has to return
428 * a boolean value: true is the entry has to be deleted, false
431 static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,
432 struct batadv_hashtable *hash,
433 bool (*to_purge)(struct batadv_priv *,
434 struct batadv_nc_path *))
436 struct hlist_head *head;
437 struct hlist_node *node_tmp;
438 struct batadv_nc_path *nc_path;
439 spinlock_t *lock; /* Protects lists in hash */
442 for (i = 0; i < hash->size; i++) {
443 head = &hash->table[i];
444 lock = &hash->list_locks[i];
446 /* For each nc_path in this bin */
448 hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) {
449 /* if an helper function has been passed as parameter,
450 * ask it if the entry has to be purged or not
452 if (to_purge && !to_purge(bat_priv, nc_path))
455 /* purging an non-empty nc_path should never happen, but
456 * is observed under high CPU load. Delay the purging
457 * until next iteration to allow the packet_list to be
460 if (!unlikely(list_empty(&nc_path->packet_list))) {
461 net_ratelimited_function(printk,
463 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
469 /* nc_path is unused, so remove it */
470 batadv_dbg(BATADV_DBG_NC, bat_priv,
471 "Remove nc_path %pM -> %pM\n",
472 nc_path->prev_hop, nc_path->next_hop);
473 hlist_del_rcu(&nc_path->hash_entry);
474 batadv_nc_path_put(nc_path);
476 spin_unlock_bh(lock);
481 * batadv_nc_hash_key_gen - computes the nc_path hash key
482 * @key: buffer to hold the final hash key
483 * @src: source ethernet mac address going into the hash key
484 * @dst: destination ethernet mac address going into the hash key
486 static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src,
489 memcpy(key->prev_hop, src, sizeof(key->prev_hop));
490 memcpy(key->next_hop, dst, sizeof(key->next_hop));
494 * batadv_nc_hash_choose - compute the hash value for an nc path
495 * @data: data to hash
496 * @size: size of the hash table
498 * Return: the selected index in the hash table for the given data.
500 static u32 batadv_nc_hash_choose(const void *data, u32 size)
502 const struct batadv_nc_path *nc_path = data;
505 hash = jhash(&nc_path->prev_hop, sizeof(nc_path->prev_hop), hash);
506 hash = jhash(&nc_path->next_hop, sizeof(nc_path->next_hop), hash);
512 * batadv_nc_hash_compare - comparing function used in the network coding hash
514 * @node: node in the local table
515 * @data2: second object to compare the node to
517 * Return: true if the two entry are the same, false otherwise
519 static bool batadv_nc_hash_compare(const struct hlist_node *node,
522 const struct batadv_nc_path *nc_path1, *nc_path2;
524 nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
527 /* Return 1 if the two keys are identical */
528 if (!batadv_compare_eth(nc_path1->prev_hop, nc_path2->prev_hop))
531 if (!batadv_compare_eth(nc_path1->next_hop, nc_path2->next_hop))
538 * batadv_nc_hash_find - search for an existing nc path and return it
539 * @hash: hash table containing the nc path
542 * Return: the nc_path if found, NULL otherwise.
544 static struct batadv_nc_path *
545 batadv_nc_hash_find(struct batadv_hashtable *hash,
548 struct hlist_head *head;
549 struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
555 index = batadv_nc_hash_choose(data, hash->size);
556 head = &hash->table[index];
559 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
560 if (!batadv_nc_hash_compare(&nc_path->hash_entry, data))
563 if (!kref_get_unless_zero(&nc_path->refcount))
566 nc_path_tmp = nc_path;
575 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
576 * @nc_packet: the nc packet to send
578 static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
580 batadv_send_unicast_skb(nc_packet->skb, nc_packet->neigh_node);
581 nc_packet->skb = NULL;
582 batadv_nc_packet_free(nc_packet);
586 * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
587 * @bat_priv: the bat priv with all the soft interface information
588 * @nc_path: the nc path the packet belongs to
589 * @nc_packet: the nc packet to be checked
591 * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
592 * timeout. If so, the packet is no longer kept and the entry deleted from the
593 * queue. Has to be called with the appropriate locks.
595 * Return: false as soon as the entry in the fifo queue has not been timed out
596 * yet and true otherwise.
598 static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
599 struct batadv_nc_path *nc_path,
600 struct batadv_nc_packet *nc_packet)
602 unsigned long timeout = bat_priv->nc.max_buffer_time;
605 lockdep_assert_held(&nc_path->packet_list_lock);
607 /* Packets are added to tail, so the remaining packets did not time
608 * out and we can stop processing the current queue
610 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
611 !batadv_has_timed_out(nc_packet->timestamp, timeout))
614 /* purge nc packet */
615 list_del(&nc_packet->list);
616 batadv_nc_packet_free(nc_packet);
625 * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
626 * @bat_priv: the bat priv with all the soft interface information
627 * @nc_path: the nc path the packet belongs to
628 * @nc_packet: the nc packet to be checked
630 * Checks whether the given nc packet has hit its forward timeout. If so, the
631 * packet is no longer delayed, immediately sent and the entry deleted from the
632 * queue. Has to be called with the appropriate locks.
634 * Return: false as soon as the entry in the fifo queue has not been timed out
635 * yet and true otherwise.
637 static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,
638 struct batadv_nc_path *nc_path,
639 struct batadv_nc_packet *nc_packet)
641 unsigned long timeout = bat_priv->nc.max_fwd_delay;
643 lockdep_assert_held(&nc_path->packet_list_lock);
645 /* Packets are added to tail, so the remaining packets did not time
646 * out and we can stop processing the current queue
648 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
649 !batadv_has_timed_out(nc_packet->timestamp, timeout))
653 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
654 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
655 nc_packet->skb->len + ETH_HLEN);
656 list_del(&nc_packet->list);
657 batadv_nc_send_packet(nc_packet);
663 * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
665 * @bat_priv: the bat priv with all the soft interface information
666 * @hash: to be processed hash table
667 * @process_fn: Function called to process given nc packet. Should return true
668 * to encourage this function to proceed with the next packet.
669 * Otherwise the rest of the current queue is skipped.
672 batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,
673 struct batadv_hashtable *hash,
674 bool (*process_fn)(struct batadv_priv *,
675 struct batadv_nc_path *,
676 struct batadv_nc_packet *))
678 struct hlist_head *head;
679 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
680 struct batadv_nc_path *nc_path;
687 /* Loop hash table bins */
688 for (i = 0; i < hash->size; i++) {
689 head = &hash->table[i];
691 /* Loop coding paths */
693 hlist_for_each_entry_rcu(nc_path, head, hash_entry) {
695 spin_lock_bh(&nc_path->packet_list_lock);
696 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
697 &nc_path->packet_list, list) {
698 ret = process_fn(bat_priv, nc_path, nc_packet);
702 spin_unlock_bh(&nc_path->packet_list_lock);
709 * batadv_nc_worker - periodic task for house keeping related to network coding
710 * @work: kernel work struct
712 static void batadv_nc_worker(struct work_struct *work)
714 struct delayed_work *delayed_work;
715 struct batadv_priv_nc *priv_nc;
716 struct batadv_priv *bat_priv;
717 unsigned long timeout;
719 delayed_work = to_delayed_work(work);
720 priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
721 bat_priv = container_of(priv_nc, struct batadv_priv, nc);
723 batadv_nc_purge_orig_hash(bat_priv);
724 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
725 batadv_nc_to_purge_nc_path_coding);
726 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
727 batadv_nc_to_purge_nc_path_decoding);
729 timeout = bat_priv->nc.max_fwd_delay;
731 if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {
732 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
733 batadv_nc_fwd_flush);
734 bat_priv->nc.timestamp_fwd_flush = jiffies;
737 if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
738 bat_priv->nc.max_buffer_time)) {
739 batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
740 batadv_nc_sniffed_purge);
741 bat_priv->nc.timestamp_sniffed_purge = jiffies;
744 /* Schedule a new check */
745 batadv_nc_start_timer(bat_priv);
749 * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
751 * @bat_priv: the bat priv with all the soft interface information
752 * @orig_node: neighboring orig node which may be used as nc candidate
753 * @ogm_packet: incoming ogm packet also used for the checks
756 * 1) The OGM must have the most recent sequence number.
757 * 2) The TTL must be decremented by one and only one.
758 * 3) The OGM must be received from the first hop from orig_node.
759 * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
761 static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
762 struct batadv_orig_node *orig_node,
763 struct batadv_ogm_packet *ogm_packet)
765 struct batadv_orig_ifinfo *orig_ifinfo;
769 orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT);
773 last_ttl = orig_ifinfo->last_ttl;
774 last_real_seqno = orig_ifinfo->last_real_seqno;
775 batadv_orig_ifinfo_put(orig_ifinfo);
777 if (last_real_seqno != ntohl(ogm_packet->seqno))
779 if (last_ttl != ogm_packet->ttl + 1)
781 if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
783 if (ogm_packet->tq < bat_priv->nc.min_tq)
790 * batadv_nc_find_nc_node - search for an existing nc node and return it
791 * @orig_node: orig node originating the ogm packet
792 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
793 * (can be equal to orig_node)
794 * @in_coding: traverse incoming or outgoing network coding list
796 * Return: the nc_node if found, NULL otherwise.
798 static struct batadv_nc_node *
799 batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
800 struct batadv_orig_node *orig_neigh_node,
803 struct batadv_nc_node *nc_node, *nc_node_out = NULL;
804 struct list_head *list;
807 list = &orig_neigh_node->in_coding_list;
809 list = &orig_neigh_node->out_coding_list;
811 /* Traverse list of nc_nodes to orig_node */
813 list_for_each_entry_rcu(nc_node, list, list) {
814 if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
817 if (!kref_get_unless_zero(&nc_node->refcount))
821 nc_node_out = nc_node;
830 * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
832 * @bat_priv: the bat priv with all the soft interface information
833 * @orig_node: orig node originating the ogm packet
834 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
835 * (can be equal to orig_node)
836 * @in_coding: traverse incoming or outgoing network coding list
838 * Return: the nc_node if found or created, NULL in case of an error.
840 static struct batadv_nc_node *
841 batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
842 struct batadv_orig_node *orig_node,
843 struct batadv_orig_node *orig_neigh_node,
846 struct batadv_nc_node *nc_node;
847 spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
848 struct list_head *list;
850 /* Select ingoing or outgoing coding node */
852 lock = &orig_neigh_node->in_coding_list_lock;
853 list = &orig_neigh_node->in_coding_list;
855 lock = &orig_neigh_node->out_coding_list_lock;
856 list = &orig_neigh_node->out_coding_list;
861 /* Check if nc_node is already added */
862 nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
868 nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
872 /* Initialize nc_node */
873 INIT_LIST_HEAD(&nc_node->list);
874 kref_init(&nc_node->refcount);
875 ether_addr_copy(nc_node->addr, orig_node->orig);
876 kref_get(&orig_neigh_node->refcount);
877 nc_node->orig_node = orig_neigh_node;
879 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
880 nc_node->addr, nc_node->orig_node->orig);
882 /* Add nc_node to orig_node */
883 kref_get(&nc_node->refcount);
884 list_add_tail_rcu(&nc_node->list, list);
887 spin_unlock_bh(lock);
893 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node
894 * structs (best called on incoming OGMs)
895 * @bat_priv: the bat priv with all the soft interface information
896 * @orig_node: orig node originating the ogm packet
897 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
898 * (can be equal to orig_node)
899 * @ogm_packet: incoming ogm packet
900 * @is_single_hop_neigh: orig_node is a single hop neighbor
902 void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
903 struct batadv_orig_node *orig_node,
904 struct batadv_orig_node *orig_neigh_node,
905 struct batadv_ogm_packet *ogm_packet,
906 int is_single_hop_neigh)
908 struct batadv_nc_node *in_nc_node = NULL;
909 struct batadv_nc_node *out_nc_node = NULL;
911 /* Check if network coding is enabled */
912 if (!atomic_read(&bat_priv->network_coding))
915 /* check if orig node is network coding enabled */
916 if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities))
919 /* accept ogms from 'good' neighbors and single hop neighbors */
920 if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
921 !is_single_hop_neigh)
924 /* Add orig_node as in_nc_node on hop */
925 in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
926 orig_neigh_node, true);
930 in_nc_node->last_seen = jiffies;
932 /* Add hop as out_nc_node on orig_node */
933 out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
938 out_nc_node->last_seen = jiffies;
942 batadv_nc_node_put(in_nc_node);
944 batadv_nc_node_put(out_nc_node);
948 * batadv_nc_get_path - get existing nc_path or allocate a new one
949 * @bat_priv: the bat priv with all the soft interface information
950 * @hash: hash table containing the nc path
951 * @src: ethernet source address - first half of the nc path search key
952 * @dst: ethernet destination address - second half of the nc path search key
954 * Return: pointer to nc_path if the path was found or created, returns NULL
957 static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
958 struct batadv_hashtable *hash,
963 struct batadv_nc_path *nc_path, nc_path_key;
965 batadv_nc_hash_key_gen(&nc_path_key, src, dst);
967 /* Search for existing nc_path */
968 nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
971 /* Set timestamp to delay removal of nc_path */
972 nc_path->last_valid = jiffies;
976 /* No existing nc_path was found; create a new */
977 nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
982 /* Initialize nc_path */
983 INIT_LIST_HEAD(&nc_path->packet_list);
984 spin_lock_init(&nc_path->packet_list_lock);
985 kref_init(&nc_path->refcount);
986 nc_path->last_valid = jiffies;
987 ether_addr_copy(nc_path->next_hop, dst);
988 ether_addr_copy(nc_path->prev_hop, src);
990 batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",
994 /* Add nc_path to hash table */
995 kref_get(&nc_path->refcount);
996 hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,
997 batadv_nc_hash_choose, &nc_path_key,
998 &nc_path->hash_entry);
1000 if (hash_added < 0) {
1009 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
1010 * selection of a receiver with slightly lower TQ than the other
1011 * @tq: to be weighted tq value
1013 * Return: scaled tq value
1015 static u8 batadv_nc_random_weight_tq(u8 tq)
1017 /* randomize the estimated packet loss (max TQ - estimated TQ) */
1018 u8 rand_tq = prandom_u32_max(BATADV_TQ_MAX_VALUE + 1 - tq);
1020 /* convert to (randomized) estimated tq again */
1021 return BATADV_TQ_MAX_VALUE - rand_tq;
1025 * batadv_nc_memxor - XOR destination with source
1026 * @dst: byte array to XOR into
1027 * @src: byte array to XOR from
1028 * @len: length of destination array
1030 static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
1034 for (i = 0; i < len; ++i)
1039 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
1040 * into a coded_packet and send it
1041 * @bat_priv: the bat priv with all the soft interface information
1042 * @skb: data skb to forward
1043 * @ethhdr: pointer to the ethernet header inside the skb
1044 * @nc_packet: structure containing the packet to the skb can be coded with
1045 * @neigh_node: next hop to forward packet to
1047 * Return: true if both packets are consumed, false otherwise.
1049 static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
1050 struct sk_buff *skb,
1051 struct ethhdr *ethhdr,
1052 struct batadv_nc_packet *nc_packet,
1053 struct batadv_neigh_node *neigh_node)
1055 u8 tq_weighted_neigh, tq_weighted_coding, tq_tmp;
1056 struct sk_buff *skb_dest, *skb_src;
1057 struct batadv_unicast_packet *packet1;
1058 struct batadv_unicast_packet *packet2;
1059 struct batadv_coded_packet *coded_packet;
1060 struct batadv_neigh_node *neigh_tmp, *router_neigh, *first_dest;
1061 struct batadv_neigh_node *router_coding = NULL, *second_dest;
1062 struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL;
1063 struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL;
1064 u8 *first_source, *second_source;
1065 __be32 packet_id1, packet_id2;
1069 int unicast_size = sizeof(*packet1);
1070 int coded_size = sizeof(*coded_packet);
1071 int header_add = coded_size - unicast_size;
1073 /* TODO: do we need to consider the outgoing interface for
1076 router_neigh = batadv_orig_router_get(neigh_node->orig_node,
1081 router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh,
1083 if (!router_neigh_ifinfo)
1086 neigh_tmp = nc_packet->neigh_node;
1087 router_coding = batadv_orig_router_get(neigh_tmp->orig_node,
1092 router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding,
1094 if (!router_coding_ifinfo)
1097 tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg;
1098 tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp);
1099 tq_tmp = router_coding_ifinfo->bat_iv.tq_avg;
1100 tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp);
1102 /* Select one destination for the MAC-header dst-field based on
1103 * weighted TQ-values.
1105 if (tq_weighted_neigh >= tq_weighted_coding) {
1106 /* Destination from nc_packet is selected for MAC-header */
1107 first_dest = nc_packet->neigh_node;
1108 first_source = nc_packet->nc_path->prev_hop;
1109 second_dest = neigh_node;
1110 second_source = ethhdr->h_source;
1111 packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1112 packet2 = (struct batadv_unicast_packet *)skb->data;
1113 packet_id1 = nc_packet->packet_id;
1114 packet_id2 = batadv_skb_crc32(skb,
1115 skb->data + sizeof(*packet2));
1117 /* Destination for skb is selected for MAC-header */
1118 first_dest = neigh_node;
1119 first_source = ethhdr->h_source;
1120 second_dest = nc_packet->neigh_node;
1121 second_source = nc_packet->nc_path->prev_hop;
1122 packet1 = (struct batadv_unicast_packet *)skb->data;
1123 packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
1124 packet_id1 = batadv_skb_crc32(skb,
1125 skb->data + sizeof(*packet1));
1126 packet_id2 = nc_packet->packet_id;
1129 /* Instead of zero padding the smallest data buffer, we
1130 * code into the largest.
1132 if (skb->len <= nc_packet->skb->len) {
1133 skb_dest = nc_packet->skb;
1137 skb_src = nc_packet->skb;
1140 /* coding_len is used when decoding the packet shorter packet */
1141 coding_len = skb_src->len - unicast_size;
1143 if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
1146 skb_push(skb_dest, header_add);
1148 coded_packet = (struct batadv_coded_packet *)skb_dest->data;
1149 skb_reset_mac_header(skb_dest);
1151 coded_packet->packet_type = BATADV_CODED;
1152 coded_packet->version = BATADV_COMPAT_VERSION;
1153 coded_packet->ttl = packet1->ttl;
1155 /* Info about first unicast packet */
1156 ether_addr_copy(coded_packet->first_source, first_source);
1157 ether_addr_copy(coded_packet->first_orig_dest, packet1->dest);
1158 coded_packet->first_crc = packet_id1;
1159 coded_packet->first_ttvn = packet1->ttvn;
1161 /* Info about second unicast packet */
1162 ether_addr_copy(coded_packet->second_dest, second_dest->addr);
1163 ether_addr_copy(coded_packet->second_source, second_source);
1164 ether_addr_copy(coded_packet->second_orig_dest, packet2->dest);
1165 coded_packet->second_crc = packet_id2;
1166 coded_packet->second_ttl = packet2->ttl;
1167 coded_packet->second_ttvn = packet2->ttvn;
1168 coded_packet->coded_len = htons(coding_len);
1170 /* This is where the magic happens: Code skb_src into skb_dest */
1171 batadv_nc_memxor(skb_dest->data + coded_size,
1172 skb_src->data + unicast_size, coding_len);
1174 /* Update counters accordingly */
1175 if (BATADV_SKB_CB(skb_src)->decoded &&
1176 BATADV_SKB_CB(skb_dest)->decoded) {
1177 /* Both packets are recoded */
1178 count = skb_src->len + ETH_HLEN;
1179 count += skb_dest->len + ETH_HLEN;
1180 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
1181 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
1182 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1183 !BATADV_SKB_CB(skb_dest)->decoded) {
1184 /* Both packets are newly coded */
1185 count = skb_src->len + ETH_HLEN;
1186 count += skb_dest->len + ETH_HLEN;
1187 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
1188 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
1189 } else if (BATADV_SKB_CB(skb_src)->decoded &&
1190 !BATADV_SKB_CB(skb_dest)->decoded) {
1191 /* skb_src recoded and skb_dest is newly coded */
1192 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1193 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1194 skb_src->len + ETH_HLEN);
1195 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1196 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1197 skb_dest->len + ETH_HLEN);
1198 } else if (!BATADV_SKB_CB(skb_src)->decoded &&
1199 BATADV_SKB_CB(skb_dest)->decoded) {
1200 /* skb_src is newly coded and skb_dest is recoded */
1201 batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
1202 batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
1203 skb_src->len + ETH_HLEN);
1204 batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
1205 batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
1206 skb_dest->len + ETH_HLEN);
1209 /* skb_src is now coded into skb_dest, so free it */
1212 /* avoid duplicate free of skb from nc_packet */
1213 nc_packet->skb = NULL;
1214 batadv_nc_packet_free(nc_packet);
1216 /* Send the coded packet and return true */
1217 batadv_send_unicast_skb(skb_dest, first_dest);
1221 batadv_neigh_node_put(router_neigh);
1223 batadv_neigh_node_put(router_coding);
1224 if (router_neigh_ifinfo)
1225 batadv_neigh_ifinfo_put(router_neigh_ifinfo);
1226 if (router_coding_ifinfo)
1227 batadv_neigh_ifinfo_put(router_coding_ifinfo);
1232 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1233 * @skb: data skb to forward
1234 * @dst: destination mac address of the other skb to code with
1235 * @src: source mac address of skb
1237 * Whenever we network code a packet we have to check whether we received it in
1238 * a network coded form. If so, we may not be able to use it for coding because
1239 * some neighbors may also have received (overheard) the packet in the network
1240 * coded form without being able to decode it. It is hard to know which of the
1241 * neighboring nodes was able to decode the packet, therefore we can only
1242 * re-code the packet if the source of the previous encoded packet is involved.
1243 * Since the source encoded the packet we can be certain it has all necessary
1244 * decode information.
1246 * Return: true if coding of a decoded packet is allowed.
1248 static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, u8 *dst, u8 *src)
1250 if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
1256 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1257 * out_nc_node to retrieve a buffered packet that can be used for coding.
1258 * @bat_priv: the bat priv with all the soft interface information
1259 * @in_nc_node: pointer to skb next hop's neighbor nc node
1260 * @out_nc_node: pointer to skb source's neighbor nc node
1261 * @skb: data skb to forward
1262 * @eth_dst: next hop mac address of skb
1264 * Return: true if coding of a decoded skb is allowed.
1266 static struct batadv_nc_packet *
1267 batadv_nc_path_search(struct batadv_priv *bat_priv,
1268 struct batadv_nc_node *in_nc_node,
1269 struct batadv_nc_node *out_nc_node,
1270 struct sk_buff *skb,
1273 struct batadv_nc_path *nc_path, nc_path_key;
1274 struct batadv_nc_packet *nc_packet_out = NULL;
1275 struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
1276 struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
1282 /* Create almost path key */
1283 batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
1285 idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
1287 /* Check for coding opportunities in this nc_path */
1289 hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
1290 if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
1293 if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
1296 spin_lock_bh(&nc_path->packet_list_lock);
1297 if (list_empty(&nc_path->packet_list)) {
1298 spin_unlock_bh(&nc_path->packet_list_lock);
1302 list_for_each_entry_safe(nc_packet, nc_packet_tmp,
1303 &nc_path->packet_list, list) {
1304 if (!batadv_nc_skb_coding_possible(nc_packet->skb,
1309 /* Coding opportunity is found! */
1310 list_del(&nc_packet->list);
1311 nc_packet_out = nc_packet;
1315 spin_unlock_bh(&nc_path->packet_list_lock);
1320 return nc_packet_out;
1324 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1325 * skb's sender (may be equal to the originator).
1326 * @bat_priv: the bat priv with all the soft interface information
1327 * @skb: data skb to forward
1328 * @eth_dst: next hop mac address of skb
1329 * @eth_src: source mac address of skb
1330 * @in_nc_node: pointer to skb next hop's neighbor nc node
1332 * Return: an nc packet if a suitable coding packet was found, NULL otherwise.
1334 static struct batadv_nc_packet *
1335 batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
1336 struct sk_buff *skb,
1339 struct batadv_nc_node *in_nc_node)
1341 struct batadv_orig_node *orig_node;
1342 struct batadv_nc_node *out_nc_node;
1343 struct batadv_nc_packet *nc_packet = NULL;
1345 orig_node = batadv_orig_hash_find(bat_priv, eth_src);
1350 list_for_each_entry_rcu(out_nc_node,
1351 &orig_node->out_coding_list, list) {
1352 /* Check if the skb is decoded and if recoding is possible */
1353 if (!batadv_nc_skb_coding_possible(skb,
1354 out_nc_node->addr, eth_src))
1357 /* Search for an opportunity in this nc_path */
1358 nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
1359 out_nc_node, skb, eth_dst);
1365 batadv_orig_node_put(orig_node);
1370 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1371 * unicast skb before it is stored for use in later decoding
1372 * @bat_priv: the bat priv with all the soft interface information
1373 * @skb: data skb to store
1374 * @eth_dst_new: new destination mac address of skb
1376 static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
1377 struct sk_buff *skb,
1380 struct ethhdr *ethhdr;
1382 /* Copy skb header to change the mac header */
1383 skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
1387 /* Set the mac header as if we actually sent the packet uncoded */
1388 ethhdr = eth_hdr(skb);
1389 ether_addr_copy(ethhdr->h_source, ethhdr->h_dest);
1390 ether_addr_copy(ethhdr->h_dest, eth_dst_new);
1392 /* Set data pointer to MAC header to mimic packets from our tx path */
1393 skb_push(skb, ETH_HLEN);
1395 /* Add the packet to the decoding packet pool */
1396 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1398 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1405 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1406 * @skb: data skb to forward
1407 * @neigh_node: next hop to forward packet to
1408 * @ethhdr: pointer to the ethernet header inside the skb
1410 * Loops through list of neighboring nodes the next hop has a good connection to
1411 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1412 * next hop that potentially sent a packet which our next hop also received
1413 * (overheard) and has stored for later decoding.
1415 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1417 static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
1418 struct batadv_neigh_node *neigh_node,
1419 struct ethhdr *ethhdr)
1421 struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1422 struct batadv_priv *bat_priv = netdev_priv(netdev);
1423 struct batadv_orig_node *orig_node = neigh_node->orig_node;
1424 struct batadv_nc_node *nc_node;
1425 struct batadv_nc_packet *nc_packet = NULL;
1428 list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
1429 /* Search for coding opportunity with this in_nc_node */
1430 nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
1432 ethhdr->h_source, nc_node);
1434 /* Opportunity was found, so stop searching */
1443 /* Save packets for later decoding */
1444 batadv_nc_skb_store_before_coding(bat_priv, skb,
1446 batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
1447 nc_packet->neigh_node->addr);
1449 /* Code and send packets */
1450 if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
1454 /* out of mem ? Coding failed - we have to free the buffered packet
1455 * to avoid memleaks. The skb passed as argument will be dealt with
1456 * by the calling function.
1458 batadv_nc_send_packet(nc_packet);
1463 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1464 * @skb: skb to add to path
1465 * @nc_path: path to add skb to
1466 * @neigh_node: next hop to forward packet to
1467 * @packet_id: checksum to identify packet
1469 * Return: true if the packet was buffered or false in case of an error.
1471 static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,
1472 struct batadv_nc_path *nc_path,
1473 struct batadv_neigh_node *neigh_node,
1476 struct batadv_nc_packet *nc_packet;
1478 nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
1482 /* Initialize nc_packet */
1483 nc_packet->timestamp = jiffies;
1484 nc_packet->packet_id = packet_id;
1485 nc_packet->skb = skb;
1486 nc_packet->neigh_node = neigh_node;
1487 nc_packet->nc_path = nc_path;
1489 /* Add coding packet to list */
1490 spin_lock_bh(&nc_path->packet_list_lock);
1491 list_add_tail(&nc_packet->list, &nc_path->packet_list);
1492 spin_unlock_bh(&nc_path->packet_list_lock);
1498 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1500 * @skb: data skb to forward
1501 * @neigh_node: next hop to forward packet to
1503 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1505 bool batadv_nc_skb_forward(struct sk_buff *skb,
1506 struct batadv_neigh_node *neigh_node)
1508 const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
1509 struct batadv_priv *bat_priv = netdev_priv(netdev);
1510 struct batadv_unicast_packet *packet;
1511 struct batadv_nc_path *nc_path;
1512 struct ethhdr *ethhdr = eth_hdr(skb);
1516 /* Check if network coding is enabled */
1517 if (!atomic_read(&bat_priv->network_coding))
1520 /* We only handle unicast packets */
1521 payload = skb_network_header(skb);
1522 packet = (struct batadv_unicast_packet *)payload;
1523 if (packet->packet_type != BATADV_UNICAST)
1526 /* Try to find a coding opportunity and send the skb if one is found */
1527 if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
1530 /* Find or create a nc_path for this src-dst pair */
1531 nc_path = batadv_nc_get_path(bat_priv,
1532 bat_priv->nc.coding_hash,
1539 /* Add skb to nc_path */
1540 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1541 if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))
1544 /* Packet is consumed */
1548 batadv_nc_path_put(nc_path);
1550 /* Packet is not consumed */
1555 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1556 * when decoding coded packets
1557 * @bat_priv: the bat priv with all the soft interface information
1558 * @skb: data skb to store
1560 void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
1561 struct sk_buff *skb)
1563 struct batadv_unicast_packet *packet;
1564 struct batadv_nc_path *nc_path;
1565 struct ethhdr *ethhdr = eth_hdr(skb);
1569 /* Check if network coding is enabled */
1570 if (!atomic_read(&bat_priv->network_coding))
1573 /* Check for supported packet type */
1574 payload = skb_network_header(skb);
1575 packet = (struct batadv_unicast_packet *)payload;
1576 if (packet->packet_type != BATADV_UNICAST)
1579 /* Find existing nc_path or create a new */
1580 nc_path = batadv_nc_get_path(bat_priv,
1581 bat_priv->nc.decoding_hash,
1588 /* Clone skb and adjust skb->data to point at batman header */
1589 skb = skb_clone(skb, GFP_ATOMIC);
1593 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
1596 if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
1599 /* Add skb to nc_path */
1600 packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
1601 if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
1604 batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
1610 batadv_nc_path_put(nc_path);
1616 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1617 * should be saved in the decoding buffer and, if so, store it there
1618 * @bat_priv: the bat priv with all the soft interface information
1619 * @skb: unicast skb to store
1621 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
1622 struct sk_buff *skb)
1624 struct ethhdr *ethhdr = eth_hdr(skb);
1626 if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
1629 /* Set data pointer to MAC header to mimic packets from our tx path */
1630 skb_push(skb, ETH_HLEN);
1632 batadv_nc_skb_store_for_decoding(bat_priv, skb);
1636 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1638 * @bat_priv: the bat priv with all the soft interface information
1639 * @skb: unicast skb to decode
1640 * @nc_packet: decode data needed to decode the skb
1642 * Return: pointer to decoded unicast packet if the packet was decoded or NULL
1643 * in case of an error.
1645 static struct batadv_unicast_packet *
1646 batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
1647 struct batadv_nc_packet *nc_packet)
1649 const int h_size = sizeof(struct batadv_unicast_packet);
1650 const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
1651 struct batadv_unicast_packet *unicast_packet;
1652 struct batadv_coded_packet coded_packet_tmp;
1653 struct ethhdr *ethhdr, ethhdr_tmp;
1654 u8 *orig_dest, ttl, ttvn;
1655 unsigned int coding_len;
1658 /* Save headers temporarily */
1659 memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
1660 memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
1662 if (skb_cow(skb, 0) < 0)
1665 if (unlikely(!skb_pull_rcsum(skb, h_diff)))
1668 /* Data points to batman header, so set mac header 14 bytes before
1669 * and network to data
1671 skb_set_mac_header(skb, -ETH_HLEN);
1672 skb_reset_network_header(skb);
1674 /* Reconstruct original mac header */
1675 ethhdr = eth_hdr(skb);
1676 *ethhdr = ethhdr_tmp;
1678 /* Select the correct unicast header information based on the location
1679 * of our mac address in the coded_packet header
1681 if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
1682 /* If we are the second destination the packet was overheard,
1683 * so the Ethernet address must be copied to h_dest and
1684 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1686 ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest);
1687 skb->pkt_type = PACKET_HOST;
1689 orig_dest = coded_packet_tmp.second_orig_dest;
1690 ttl = coded_packet_tmp.second_ttl;
1691 ttvn = coded_packet_tmp.second_ttvn;
1693 orig_dest = coded_packet_tmp.first_orig_dest;
1694 ttl = coded_packet_tmp.ttl;
1695 ttvn = coded_packet_tmp.first_ttvn;
1698 coding_len = ntohs(coded_packet_tmp.coded_len);
1700 if (coding_len > skb->len)
1703 /* Here the magic is reversed:
1704 * extract the missing packet from the received coded packet
1706 batadv_nc_memxor(skb->data + h_size,
1707 nc_packet->skb->data + h_size,
1710 /* Resize decoded skb if decoded with larger packet */
1711 if (nc_packet->skb->len > coding_len + h_size) {
1712 err = pskb_trim_rcsum(skb, coding_len + h_size);
1717 /* Create decoded unicast packet */
1718 unicast_packet = (struct batadv_unicast_packet *)skb->data;
1719 unicast_packet->packet_type = BATADV_UNICAST;
1720 unicast_packet->version = BATADV_COMPAT_VERSION;
1721 unicast_packet->ttl = ttl;
1722 ether_addr_copy(unicast_packet->dest, orig_dest);
1723 unicast_packet->ttvn = ttvn;
1725 batadv_nc_packet_free(nc_packet);
1726 return unicast_packet;
1730 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1731 * find the data needed to decode the coded packet
1732 * @bat_priv: the bat priv with all the soft interface information
1733 * @ethhdr: pointer to the ethernet header inside the coded packet
1734 * @coded: coded packet we try to find decode data for
1736 * Return: pointer to nc packet if the needed data was found or NULL otherwise.
1738 static struct batadv_nc_packet *
1739 batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
1740 struct ethhdr *ethhdr,
1741 struct batadv_coded_packet *coded)
1743 struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
1744 struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
1745 struct batadv_nc_path *nc_path, nc_path_key;
1753 /* Select the correct packet id based on the location of our mac-addr */
1754 dest = ethhdr->h_source;
1755 if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
1756 source = coded->second_source;
1757 packet_id = coded->second_crc;
1759 source = coded->first_source;
1760 packet_id = coded->first_crc;
1763 batadv_nc_hash_key_gen(&nc_path_key, source, dest);
1764 index = batadv_nc_hash_choose(&nc_path_key, hash->size);
1766 /* Search for matching coding path */
1768 hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
1769 /* Find matching nc_packet */
1770 spin_lock_bh(&nc_path->packet_list_lock);
1771 list_for_each_entry(tmp_nc_packet,
1772 &nc_path->packet_list, list) {
1773 if (packet_id == tmp_nc_packet->packet_id) {
1774 list_del(&tmp_nc_packet->list);
1776 nc_packet = tmp_nc_packet;
1780 spin_unlock_bh(&nc_path->packet_list_lock);
1788 batadv_dbg(BATADV_DBG_NC, bat_priv,
1789 "No decoding packet found for %u\n", packet_id);
1795 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1796 * resulting unicast packet
1797 * @skb: incoming coded packet
1798 * @recv_if: pointer to interface this packet was received on
1800 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1803 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
1804 struct batadv_hard_iface *recv_if)
1806 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1807 struct batadv_unicast_packet *unicast_packet;
1808 struct batadv_coded_packet *coded_packet;
1809 struct batadv_nc_packet *nc_packet;
1810 struct ethhdr *ethhdr;
1811 int hdr_size = sizeof(*coded_packet);
1813 /* Check if network coding is enabled */
1814 if (!atomic_read(&bat_priv->network_coding))
1817 /* Make sure we can access (and remove) header */
1818 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1821 coded_packet = (struct batadv_coded_packet *)skb->data;
1822 ethhdr = eth_hdr(skb);
1824 /* Verify frame is destined for us */
1825 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
1826 !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1829 /* Update stat counter */
1830 if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
1831 batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
1833 nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
1836 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1840 /* Make skb's linear, because decoding accesses the entire buffer */
1841 if (skb_linearize(skb) < 0)
1842 goto free_nc_packet;
1844 if (skb_linearize(nc_packet->skb) < 0)
1845 goto free_nc_packet;
1847 /* Decode the packet */
1848 unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
1849 if (!unicast_packet) {
1850 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
1851 goto free_nc_packet;
1854 /* Mark packet as decoded to do correct recoding when forwarding */
1855 BATADV_SKB_CB(skb)->decoded = true;
1856 batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
1857 batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
1858 skb->len + ETH_HLEN);
1859 return batadv_recv_unicast_packet(skb, recv_if);
1862 batadv_nc_packet_free(nc_packet);
1867 * batadv_nc_mesh_free - clean up network coding memory
1868 * @bat_priv: the bat priv with all the soft interface information
1870 void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
1872 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
1873 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1);
1874 cancel_delayed_work_sync(&bat_priv->nc.work);
1876 batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
1877 batadv_hash_destroy(bat_priv->nc.coding_hash);
1878 batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
1879 batadv_hash_destroy(bat_priv->nc.decoding_hash);
1882 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
1884 * batadv_nc_nodes_seq_print_text - print the nc node information
1885 * @seq: seq file to print on
1890 int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
1892 struct net_device *net_dev = (struct net_device *)seq->private;
1893 struct batadv_priv *bat_priv = netdev_priv(net_dev);
1894 struct batadv_hashtable *hash = bat_priv->orig_hash;
1895 struct batadv_hard_iface *primary_if;
1896 struct hlist_head *head;
1897 struct batadv_orig_node *orig_node;
1898 struct batadv_nc_node *nc_node;
1901 primary_if = batadv_seq_print_text_primary_if_get(seq);
1905 /* Traverse list of originators */
1906 for (i = 0; i < hash->size; i++) {
1907 head = &hash->table[i];
1909 /* For each orig_node in this bin */
1911 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1912 /* no need to print the orig node if it does not have
1913 * network coding neighbors
1915 if (list_empty(&orig_node->in_coding_list) &&
1916 list_empty(&orig_node->out_coding_list))
1919 seq_printf(seq, "Node: %pM\n", orig_node->orig);
1921 seq_puts(seq, " Ingoing: ");
1922 /* For each in_nc_node to this orig_node */
1923 list_for_each_entry_rcu(nc_node,
1924 &orig_node->in_coding_list,
1926 seq_printf(seq, "%pM ",
1928 seq_puts(seq, "\n");
1930 seq_puts(seq, " Outgoing: ");
1931 /* For out_nc_node to this orig_node */
1932 list_for_each_entry_rcu(nc_node,
1933 &orig_node->out_coding_list,
1935 seq_printf(seq, "%pM ",
1937 seq_puts(seq, "\n\n");
1944 batadv_hardif_put(primary_if);
1949 * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1950 * @bat_priv: the bat priv with all the soft interface information
1952 * Return: 0 on success or negative error number in case of failure
1954 int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
1956 struct dentry *nc_dir, *file;
1958 nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
1962 file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
1963 &bat_priv->nc.min_tq);
1967 file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,
1968 &bat_priv->nc.max_fwd_delay);
1972 file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
1973 &bat_priv->nc.max_buffer_time);