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"
54 #include "originator.h"
59 static struct lock_class_key batadv_nc_coding_hash_lock_class_key
;
60 static struct lock_class_key batadv_nc_decoding_hash_lock_class_key
;
62 static void batadv_nc_worker(struct work_struct
*work
);
63 static int batadv_nc_recv_coded_packet(struct sk_buff
*skb
,
64 struct batadv_hard_iface
*recv_if
);
67 * batadv_nc_init - one-time initialization for network coding
69 * Return: 0 on success or negative error number in case of failure
71 int __init
batadv_nc_init(void)
75 /* Register our packet type */
76 ret
= batadv_recv_handler_register(BATADV_CODED
,
77 batadv_nc_recv_coded_packet
);
83 * batadv_nc_start_timer - initialise the nc periodic worker
84 * @bat_priv: the bat priv with all the soft interface information
86 static void batadv_nc_start_timer(struct batadv_priv
*bat_priv
)
88 queue_delayed_work(batadv_event_workqueue
, &bat_priv
->nc
.work
,
89 msecs_to_jiffies(10));
93 * batadv_nc_tvlv_container_update - update the network coding tvlv container
94 * after network coding setting change
95 * @bat_priv: the bat priv with all the soft interface information
97 static void batadv_nc_tvlv_container_update(struct batadv_priv
*bat_priv
)
101 nc_mode
= atomic_read(&bat_priv
->network_coding
);
105 batadv_tvlv_container_unregister(bat_priv
, BATADV_TVLV_NC
, 1);
108 batadv_tvlv_container_register(bat_priv
, BATADV_TVLV_NC
, 1,
115 * batadv_nc_status_update - update the network coding tvlv container after
116 * network coding setting change
117 * @net_dev: the soft interface net device
119 void batadv_nc_status_update(struct net_device
*net_dev
)
121 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
123 batadv_nc_tvlv_container_update(bat_priv
);
127 * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
128 * @bat_priv: the bat priv with all the soft interface information
129 * @orig: the orig_node of the ogm
130 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
131 * @tvlv_value: tvlv buffer containing the gateway data
132 * @tvlv_value_len: tvlv buffer length
134 static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv
*bat_priv
,
135 struct batadv_orig_node
*orig
,
137 void *tvlv_value
, u16 tvlv_value_len
)
139 if (flags
& BATADV_TVLV_HANDLER_OGM_CIFNOTFND
)
140 clear_bit(BATADV_ORIG_CAPA_HAS_NC
, &orig
->capabilities
);
142 set_bit(BATADV_ORIG_CAPA_HAS_NC
, &orig
->capabilities
);
146 * batadv_nc_mesh_init - initialise coding hash table and start house keeping
147 * @bat_priv: the bat priv with all the soft interface information
149 * Return: 0 on success or negative error number in case of failure
151 int batadv_nc_mesh_init(struct batadv_priv
*bat_priv
)
153 bat_priv
->nc
.timestamp_fwd_flush
= jiffies
;
154 bat_priv
->nc
.timestamp_sniffed_purge
= jiffies
;
156 if (bat_priv
->nc
.coding_hash
|| bat_priv
->nc
.decoding_hash
)
159 bat_priv
->nc
.coding_hash
= batadv_hash_new(128);
160 if (!bat_priv
->nc
.coding_hash
)
163 batadv_hash_set_lock_class(bat_priv
->nc
.coding_hash
,
164 &batadv_nc_coding_hash_lock_class_key
);
166 bat_priv
->nc
.decoding_hash
= batadv_hash_new(128);
167 if (!bat_priv
->nc
.decoding_hash
)
170 batadv_hash_set_lock_class(bat_priv
->nc
.decoding_hash
,
171 &batadv_nc_decoding_hash_lock_class_key
);
173 INIT_DELAYED_WORK(&bat_priv
->nc
.work
, batadv_nc_worker
);
174 batadv_nc_start_timer(bat_priv
);
176 batadv_tvlv_handler_register(bat_priv
, batadv_nc_tvlv_ogm_handler_v1
,
177 NULL
, BATADV_TVLV_NC
, 1,
178 BATADV_TVLV_HANDLER_OGM_CIFNOTFND
);
179 batadv_nc_tvlv_container_update(bat_priv
);
187 * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
188 * @bat_priv: the bat priv with all the soft interface information
190 void batadv_nc_init_bat_priv(struct batadv_priv
*bat_priv
)
192 atomic_set(&bat_priv
->network_coding
, 0);
193 bat_priv
->nc
.min_tq
= 200;
194 bat_priv
->nc
.max_fwd_delay
= 10;
195 bat_priv
->nc
.max_buffer_time
= 200;
199 * batadv_nc_init_orig - initialise the nc fields of an orig_node
200 * @orig_node: the orig_node which is going to be initialised
202 void batadv_nc_init_orig(struct batadv_orig_node
*orig_node
)
204 INIT_LIST_HEAD(&orig_node
->in_coding_list
);
205 INIT_LIST_HEAD(&orig_node
->out_coding_list
);
206 spin_lock_init(&orig_node
->in_coding_list_lock
);
207 spin_lock_init(&orig_node
->out_coding_list_lock
);
211 * batadv_nc_node_release - release nc_node from lists and queue for free after
213 * @ref: kref pointer of the nc_node
215 static void batadv_nc_node_release(struct kref
*ref
)
217 struct batadv_nc_node
*nc_node
;
219 nc_node
= container_of(ref
, struct batadv_nc_node
, refcount
);
221 batadv_orig_node_put(nc_node
->orig_node
);
222 kfree_rcu(nc_node
, rcu
);
226 * batadv_nc_node_put - decrement the nc_node refcounter and possibly
228 * @nc_node: nc_node to be free'd
230 static void batadv_nc_node_put(struct batadv_nc_node
*nc_node
)
232 kref_put(&nc_node
->refcount
, batadv_nc_node_release
);
236 * batadv_nc_path_release - release nc_path from lists and queue for free after
238 * @ref: kref pointer of the nc_path
240 static void batadv_nc_path_release(struct kref
*ref
)
242 struct batadv_nc_path
*nc_path
;
244 nc_path
= container_of(ref
, struct batadv_nc_path
, refcount
);
246 kfree_rcu(nc_path
, rcu
);
250 * batadv_nc_path_put - decrement the nc_path refcounter and possibly
252 * @nc_path: nc_path to be free'd
254 static void batadv_nc_path_put(struct batadv_nc_path
*nc_path
)
256 kref_put(&nc_path
->refcount
, batadv_nc_path_release
);
260 * batadv_nc_packet_free - frees nc packet
261 * @nc_packet: the nc packet to free
263 static void batadv_nc_packet_free(struct batadv_nc_packet
*nc_packet
)
265 kfree_skb(nc_packet
->skb
);
266 batadv_nc_path_put(nc_packet
->nc_path
);
271 * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
272 * @bat_priv: the bat priv with all the soft interface information
273 * @nc_node: the nc node to check
275 * Return: true if the entry has to be purged now, false otherwise
277 static bool batadv_nc_to_purge_nc_node(struct batadv_priv
*bat_priv
,
278 struct batadv_nc_node
*nc_node
)
280 if (atomic_read(&bat_priv
->mesh_state
) != BATADV_MESH_ACTIVE
)
283 return batadv_has_timed_out(nc_node
->last_seen
, BATADV_NC_NODE_TIMEOUT
);
287 * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
288 * @bat_priv: the bat priv with all the soft interface information
289 * @nc_path: the nc path to check
291 * Return: true if the entry has to be purged now, false otherwise
293 static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv
*bat_priv
,
294 struct batadv_nc_path
*nc_path
)
296 if (atomic_read(&bat_priv
->mesh_state
) != BATADV_MESH_ACTIVE
)
299 /* purge the path when no packets has been added for 10 times the
302 return batadv_has_timed_out(nc_path
->last_valid
,
303 bat_priv
->nc
.max_fwd_delay
* 10);
307 * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
308 * @bat_priv: the bat priv with all the soft interface information
309 * @nc_path: the nc path to check
311 * Return: true if the entry has to be purged now, false otherwise
313 static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv
*bat_priv
,
314 struct batadv_nc_path
*nc_path
)
316 if (atomic_read(&bat_priv
->mesh_state
) != BATADV_MESH_ACTIVE
)
319 /* purge the path when no packets has been added for 10 times the
322 return batadv_has_timed_out(nc_path
->last_valid
,
323 bat_priv
->nc
.max_buffer_time
* 10);
327 * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
329 * @bat_priv: the bat priv with all the soft interface information
330 * @list: list of nc nodes
331 * @lock: nc node list lock
332 * @to_purge: function in charge to decide whether an entry has to be purged or
333 * not. This function takes the nc node as argument and has to return
334 * a boolean value: true if the entry has to be deleted, false
338 batadv_nc_purge_orig_nc_nodes(struct batadv_priv
*bat_priv
,
339 struct list_head
*list
,
341 bool (*to_purge
)(struct batadv_priv
*,
342 struct batadv_nc_node
*))
344 struct batadv_nc_node
*nc_node
, *nc_node_tmp
;
346 /* For each nc_node in list */
348 list_for_each_entry_safe(nc_node
, nc_node_tmp
, list
, list
) {
349 /* if an helper function has been passed as parameter,
350 * ask it if the entry has to be purged or not
352 if (to_purge
&& !to_purge(bat_priv
, nc_node
))
355 batadv_dbg(BATADV_DBG_NC
, bat_priv
,
356 "Removing nc_node %pM -> %pM\n",
357 nc_node
->addr
, nc_node
->orig_node
->orig
);
358 list_del_rcu(&nc_node
->list
);
359 batadv_nc_node_put(nc_node
);
361 spin_unlock_bh(lock
);
365 * batadv_nc_purge_orig - purges all nc node data attached of the given
367 * @bat_priv: the bat priv with all the soft interface information
368 * @orig_node: orig_node with the nc node entries to be purged
369 * @to_purge: function in charge to decide whether an entry has to be purged or
370 * not. This function takes the nc node as argument and has to return
371 * a boolean value: true is the entry has to be deleted, false
374 void batadv_nc_purge_orig(struct batadv_priv
*bat_priv
,
375 struct batadv_orig_node
*orig_node
,
376 bool (*to_purge
)(struct batadv_priv
*,
377 struct batadv_nc_node
*))
379 /* Check ingoing nc_node's of this orig_node */
380 batadv_nc_purge_orig_nc_nodes(bat_priv
, &orig_node
->in_coding_list
,
381 &orig_node
->in_coding_list_lock
,
384 /* Check outgoing nc_node's of this orig_node */
385 batadv_nc_purge_orig_nc_nodes(bat_priv
, &orig_node
->out_coding_list
,
386 &orig_node
->out_coding_list_lock
,
391 * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
392 * have timed out nc nodes
393 * @bat_priv: the bat priv with all the soft interface information
395 static void batadv_nc_purge_orig_hash(struct batadv_priv
*bat_priv
)
397 struct batadv_hashtable
*hash
= bat_priv
->orig_hash
;
398 struct hlist_head
*head
;
399 struct batadv_orig_node
*orig_node
;
405 /* For each orig_node */
406 for (i
= 0; i
< hash
->size
; i
++) {
407 head
= &hash
->table
[i
];
410 hlist_for_each_entry_rcu(orig_node
, head
, hash_entry
)
411 batadv_nc_purge_orig(bat_priv
, orig_node
,
412 batadv_nc_to_purge_nc_node
);
418 * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
420 * @bat_priv: the bat priv with all the soft interface information
421 * @hash: hash table containing the nc paths to check
422 * @to_purge: function in charge to decide whether an entry has to be purged or
423 * not. This function takes the nc node as argument and has to return
424 * a boolean value: true is the entry has to be deleted, false
427 static void batadv_nc_purge_paths(struct batadv_priv
*bat_priv
,
428 struct batadv_hashtable
*hash
,
429 bool (*to_purge
)(struct batadv_priv
*,
430 struct batadv_nc_path
*))
432 struct hlist_head
*head
;
433 struct hlist_node
*node_tmp
;
434 struct batadv_nc_path
*nc_path
;
435 spinlock_t
*lock
; /* Protects lists in hash */
438 for (i
= 0; i
< hash
->size
; i
++) {
439 head
= &hash
->table
[i
];
440 lock
= &hash
->list_locks
[i
];
442 /* For each nc_path in this bin */
444 hlist_for_each_entry_safe(nc_path
, node_tmp
, head
, hash_entry
) {
445 /* if an helper function has been passed as parameter,
446 * ask it if the entry has to be purged or not
448 if (to_purge
&& !to_purge(bat_priv
, nc_path
))
451 /* purging an non-empty nc_path should never happen, but
452 * is observed under high CPU load. Delay the purging
453 * until next iteration to allow the packet_list to be
456 if (!unlikely(list_empty(&nc_path
->packet_list
))) {
457 net_ratelimited_function(printk
,
459 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
465 /* nc_path is unused, so remove it */
466 batadv_dbg(BATADV_DBG_NC
, bat_priv
,
467 "Remove nc_path %pM -> %pM\n",
468 nc_path
->prev_hop
, nc_path
->next_hop
);
469 hlist_del_rcu(&nc_path
->hash_entry
);
470 batadv_nc_path_put(nc_path
);
472 spin_unlock_bh(lock
);
477 * batadv_nc_hash_key_gen - computes the nc_path hash key
478 * @key: buffer to hold the final hash key
479 * @src: source ethernet mac address going into the hash key
480 * @dst: destination ethernet mac address going into the hash key
482 static void batadv_nc_hash_key_gen(struct batadv_nc_path
*key
, const char *src
,
485 memcpy(key
->prev_hop
, src
, sizeof(key
->prev_hop
));
486 memcpy(key
->next_hop
, dst
, sizeof(key
->next_hop
));
490 * batadv_nc_hash_choose - compute the hash value for an nc path
491 * @data: data to hash
492 * @size: size of the hash table
494 * Return: the selected index in the hash table for the given data.
496 static u32
batadv_nc_hash_choose(const void *data
, u32 size
)
498 const struct batadv_nc_path
*nc_path
= data
;
501 hash
= jhash(&nc_path
->prev_hop
, sizeof(nc_path
->prev_hop
), hash
);
502 hash
= jhash(&nc_path
->next_hop
, sizeof(nc_path
->next_hop
), hash
);
508 * batadv_nc_hash_compare - comparing function used in the network coding hash
510 * @node: node in the local table
511 * @data2: second object to compare the node to
513 * Return: true if the two entry are the same, false otherwise
515 static bool batadv_nc_hash_compare(const struct hlist_node
*node
,
518 const struct batadv_nc_path
*nc_path1
, *nc_path2
;
520 nc_path1
= container_of(node
, struct batadv_nc_path
, hash_entry
);
523 /* Return 1 if the two keys are identical */
524 if (!batadv_compare_eth(nc_path1
->prev_hop
, nc_path2
->prev_hop
))
527 if (!batadv_compare_eth(nc_path1
->next_hop
, nc_path2
->next_hop
))
534 * batadv_nc_hash_find - search for an existing nc path and return it
535 * @hash: hash table containing the nc path
538 * Return: the nc_path if found, NULL otherwise.
540 static struct batadv_nc_path
*
541 batadv_nc_hash_find(struct batadv_hashtable
*hash
,
544 struct hlist_head
*head
;
545 struct batadv_nc_path
*nc_path
, *nc_path_tmp
= NULL
;
551 index
= batadv_nc_hash_choose(data
, hash
->size
);
552 head
= &hash
->table
[index
];
555 hlist_for_each_entry_rcu(nc_path
, head
, hash_entry
) {
556 if (!batadv_nc_hash_compare(&nc_path
->hash_entry
, data
))
559 if (!kref_get_unless_zero(&nc_path
->refcount
))
562 nc_path_tmp
= nc_path
;
571 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
572 * @nc_packet: the nc packet to send
574 static void batadv_nc_send_packet(struct batadv_nc_packet
*nc_packet
)
576 batadv_send_unicast_skb(nc_packet
->skb
, nc_packet
->neigh_node
);
577 nc_packet
->skb
= NULL
;
578 batadv_nc_packet_free(nc_packet
);
582 * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
583 * @bat_priv: the bat priv with all the soft interface information
584 * @nc_path: the nc path the packet belongs to
585 * @nc_packet: the nc packet to be checked
587 * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
588 * timeout. If so, the packet is no longer kept and the entry deleted from the
589 * queue. Has to be called with the appropriate locks.
591 * Return: false as soon as the entry in the fifo queue has not been timed out
592 * yet and true otherwise.
594 static bool batadv_nc_sniffed_purge(struct batadv_priv
*bat_priv
,
595 struct batadv_nc_path
*nc_path
,
596 struct batadv_nc_packet
*nc_packet
)
598 unsigned long timeout
= bat_priv
->nc
.max_buffer_time
;
601 lockdep_assert_held(&nc_path
->packet_list_lock
);
603 /* Packets are added to tail, so the remaining packets did not time
604 * out and we can stop processing the current queue
606 if (atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_ACTIVE
&&
607 !batadv_has_timed_out(nc_packet
->timestamp
, timeout
))
610 /* purge nc packet */
611 list_del(&nc_packet
->list
);
612 batadv_nc_packet_free(nc_packet
);
621 * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
622 * @bat_priv: the bat priv with all the soft interface information
623 * @nc_path: the nc path the packet belongs to
624 * @nc_packet: the nc packet to be checked
626 * Checks whether the given nc packet has hit its forward timeout. If so, the
627 * packet is no longer delayed, immediately sent and the entry deleted from the
628 * queue. Has to be called with the appropriate locks.
630 * Return: false as soon as the entry in the fifo queue has not been timed out
631 * yet and true otherwise.
633 static bool batadv_nc_fwd_flush(struct batadv_priv
*bat_priv
,
634 struct batadv_nc_path
*nc_path
,
635 struct batadv_nc_packet
*nc_packet
)
637 unsigned long timeout
= bat_priv
->nc
.max_fwd_delay
;
639 lockdep_assert_held(&nc_path
->packet_list_lock
);
641 /* Packets are added to tail, so the remaining packets did not time
642 * out and we can stop processing the current queue
644 if (atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_ACTIVE
&&
645 !batadv_has_timed_out(nc_packet
->timestamp
, timeout
))
649 batadv_inc_counter(bat_priv
, BATADV_CNT_FORWARD
);
650 batadv_add_counter(bat_priv
, BATADV_CNT_FORWARD_BYTES
,
651 nc_packet
->skb
->len
+ ETH_HLEN
);
652 list_del(&nc_packet
->list
);
653 batadv_nc_send_packet(nc_packet
);
659 * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
661 * @bat_priv: the bat priv with all the soft interface information
662 * @hash: to be processed hash table
663 * @process_fn: Function called to process given nc packet. Should return true
664 * to encourage this function to proceed with the next packet.
665 * Otherwise the rest of the current queue is skipped.
668 batadv_nc_process_nc_paths(struct batadv_priv
*bat_priv
,
669 struct batadv_hashtable
*hash
,
670 bool (*process_fn
)(struct batadv_priv
*,
671 struct batadv_nc_path
*,
672 struct batadv_nc_packet
*))
674 struct hlist_head
*head
;
675 struct batadv_nc_packet
*nc_packet
, *nc_packet_tmp
;
676 struct batadv_nc_path
*nc_path
;
683 /* Loop hash table bins */
684 for (i
= 0; i
< hash
->size
; i
++) {
685 head
= &hash
->table
[i
];
687 /* Loop coding paths */
689 hlist_for_each_entry_rcu(nc_path
, head
, hash_entry
) {
691 spin_lock_bh(&nc_path
->packet_list_lock
);
692 list_for_each_entry_safe(nc_packet
, nc_packet_tmp
,
693 &nc_path
->packet_list
, list
) {
694 ret
= process_fn(bat_priv
, nc_path
, nc_packet
);
698 spin_unlock_bh(&nc_path
->packet_list_lock
);
705 * batadv_nc_worker - periodic task for house keeping related to network coding
706 * @work: kernel work struct
708 static void batadv_nc_worker(struct work_struct
*work
)
710 struct delayed_work
*delayed_work
;
711 struct batadv_priv_nc
*priv_nc
;
712 struct batadv_priv
*bat_priv
;
713 unsigned long timeout
;
715 delayed_work
= to_delayed_work(work
);
716 priv_nc
= container_of(delayed_work
, struct batadv_priv_nc
, work
);
717 bat_priv
= container_of(priv_nc
, struct batadv_priv
, nc
);
719 batadv_nc_purge_orig_hash(bat_priv
);
720 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.coding_hash
,
721 batadv_nc_to_purge_nc_path_coding
);
722 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.decoding_hash
,
723 batadv_nc_to_purge_nc_path_decoding
);
725 timeout
= bat_priv
->nc
.max_fwd_delay
;
727 if (batadv_has_timed_out(bat_priv
->nc
.timestamp_fwd_flush
, timeout
)) {
728 batadv_nc_process_nc_paths(bat_priv
, bat_priv
->nc
.coding_hash
,
729 batadv_nc_fwd_flush
);
730 bat_priv
->nc
.timestamp_fwd_flush
= jiffies
;
733 if (batadv_has_timed_out(bat_priv
->nc
.timestamp_sniffed_purge
,
734 bat_priv
->nc
.max_buffer_time
)) {
735 batadv_nc_process_nc_paths(bat_priv
, bat_priv
->nc
.decoding_hash
,
736 batadv_nc_sniffed_purge
);
737 bat_priv
->nc
.timestamp_sniffed_purge
= jiffies
;
740 /* Schedule a new check */
741 batadv_nc_start_timer(bat_priv
);
745 * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
747 * @bat_priv: the bat priv with all the soft interface information
748 * @orig_node: neighboring orig node which may be used as nc candidate
749 * @ogm_packet: incoming ogm packet also used for the checks
752 * 1) The OGM must have the most recent sequence number.
753 * 2) The TTL must be decremented by one and only one.
754 * 3) The OGM must be received from the first hop from orig_node.
755 * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
757 static bool batadv_can_nc_with_orig(struct batadv_priv
*bat_priv
,
758 struct batadv_orig_node
*orig_node
,
759 struct batadv_ogm_packet
*ogm_packet
)
761 struct batadv_orig_ifinfo
*orig_ifinfo
;
765 orig_ifinfo
= batadv_orig_ifinfo_get(orig_node
, BATADV_IF_DEFAULT
);
769 last_ttl
= orig_ifinfo
->last_ttl
;
770 last_real_seqno
= orig_ifinfo
->last_real_seqno
;
771 batadv_orig_ifinfo_put(orig_ifinfo
);
773 if (last_real_seqno
!= ntohl(ogm_packet
->seqno
))
775 if (last_ttl
!= ogm_packet
->ttl
+ 1)
777 if (!batadv_compare_eth(ogm_packet
->orig
, ogm_packet
->prev_sender
))
779 if (ogm_packet
->tq
< bat_priv
->nc
.min_tq
)
786 * batadv_nc_find_nc_node - search for an existing nc node and return it
787 * @orig_node: orig node originating the ogm packet
788 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
789 * (can be equal to orig_node)
790 * @in_coding: traverse incoming or outgoing network coding list
792 * Return: the nc_node if found, NULL otherwise.
794 static struct batadv_nc_node
*
795 batadv_nc_find_nc_node(struct batadv_orig_node
*orig_node
,
796 struct batadv_orig_node
*orig_neigh_node
,
799 struct batadv_nc_node
*nc_node
, *nc_node_out
= NULL
;
800 struct list_head
*list
;
803 list
= &orig_neigh_node
->in_coding_list
;
805 list
= &orig_neigh_node
->out_coding_list
;
807 /* Traverse list of nc_nodes to orig_node */
809 list_for_each_entry_rcu(nc_node
, list
, list
) {
810 if (!batadv_compare_eth(nc_node
->addr
, orig_node
->orig
))
813 if (!kref_get_unless_zero(&nc_node
->refcount
))
817 nc_node_out
= nc_node
;
826 * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
828 * @bat_priv: the bat priv with all the soft interface information
829 * @orig_node: orig node originating the ogm packet
830 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
831 * (can be equal to orig_node)
832 * @in_coding: traverse incoming or outgoing network coding list
834 * Return: the nc_node if found or created, NULL in case of an error.
836 static struct batadv_nc_node
*
837 batadv_nc_get_nc_node(struct batadv_priv
*bat_priv
,
838 struct batadv_orig_node
*orig_node
,
839 struct batadv_orig_node
*orig_neigh_node
,
842 struct batadv_nc_node
*nc_node
;
843 spinlock_t
*lock
; /* Used to lock list selected by "int in_coding" */
844 struct list_head
*list
;
846 /* Check if nc_node is already added */
847 nc_node
= batadv_nc_find_nc_node(orig_node
, orig_neigh_node
, in_coding
);
853 nc_node
= kzalloc(sizeof(*nc_node
), GFP_ATOMIC
);
857 kref_get(&orig_neigh_node
->refcount
);
859 /* Initialize nc_node */
860 INIT_LIST_HEAD(&nc_node
->list
);
861 ether_addr_copy(nc_node
->addr
, orig_node
->orig
);
862 nc_node
->orig_node
= orig_neigh_node
;
863 kref_init(&nc_node
->refcount
);
864 kref_get(&nc_node
->refcount
);
866 /* Select ingoing or outgoing coding node */
868 lock
= &orig_neigh_node
->in_coding_list_lock
;
869 list
= &orig_neigh_node
->in_coding_list
;
871 lock
= &orig_neigh_node
->out_coding_list_lock
;
872 list
= &orig_neigh_node
->out_coding_list
;
875 batadv_dbg(BATADV_DBG_NC
, bat_priv
, "Adding nc_node %pM -> %pM\n",
876 nc_node
->addr
, nc_node
->orig_node
->orig
);
878 /* Add nc_node to orig_node */
880 list_add_tail_rcu(&nc_node
->list
, list
);
881 spin_unlock_bh(lock
);
887 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node
888 * structs (best called on incoming OGMs)
889 * @bat_priv: the bat priv with all the soft interface information
890 * @orig_node: orig node originating the ogm packet
891 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
892 * (can be equal to orig_node)
893 * @ogm_packet: incoming ogm packet
894 * @is_single_hop_neigh: orig_node is a single hop neighbor
896 void batadv_nc_update_nc_node(struct batadv_priv
*bat_priv
,
897 struct batadv_orig_node
*orig_node
,
898 struct batadv_orig_node
*orig_neigh_node
,
899 struct batadv_ogm_packet
*ogm_packet
,
900 int is_single_hop_neigh
)
902 struct batadv_nc_node
*in_nc_node
= NULL
;
903 struct batadv_nc_node
*out_nc_node
= NULL
;
905 /* Check if network coding is enabled */
906 if (!atomic_read(&bat_priv
->network_coding
))
909 /* check if orig node is network coding enabled */
910 if (!test_bit(BATADV_ORIG_CAPA_HAS_NC
, &orig_node
->capabilities
))
913 /* accept ogms from 'good' neighbors and single hop neighbors */
914 if (!batadv_can_nc_with_orig(bat_priv
, orig_node
, ogm_packet
) &&
915 !is_single_hop_neigh
)
918 /* Add orig_node as in_nc_node on hop */
919 in_nc_node
= batadv_nc_get_nc_node(bat_priv
, orig_node
,
920 orig_neigh_node
, true);
924 in_nc_node
->last_seen
= jiffies
;
926 /* Add hop as out_nc_node on orig_node */
927 out_nc_node
= batadv_nc_get_nc_node(bat_priv
, orig_neigh_node
,
932 out_nc_node
->last_seen
= jiffies
;
936 batadv_nc_node_put(in_nc_node
);
938 batadv_nc_node_put(out_nc_node
);
942 * batadv_nc_get_path - get existing nc_path or allocate a new one
943 * @bat_priv: the bat priv with all the soft interface information
944 * @hash: hash table containing the nc path
945 * @src: ethernet source address - first half of the nc path search key
946 * @dst: ethernet destination address - second half of the nc path search key
948 * Return: pointer to nc_path if the path was found or created, returns NULL
951 static struct batadv_nc_path
*batadv_nc_get_path(struct batadv_priv
*bat_priv
,
952 struct batadv_hashtable
*hash
,
957 struct batadv_nc_path
*nc_path
, nc_path_key
;
959 batadv_nc_hash_key_gen(&nc_path_key
, src
, dst
);
961 /* Search for existing nc_path */
962 nc_path
= batadv_nc_hash_find(hash
, (void *)&nc_path_key
);
965 /* Set timestamp to delay removal of nc_path */
966 nc_path
->last_valid
= jiffies
;
970 /* No existing nc_path was found; create a new */
971 nc_path
= kzalloc(sizeof(*nc_path
), GFP_ATOMIC
);
976 /* Initialize nc_path */
977 INIT_LIST_HEAD(&nc_path
->packet_list
);
978 spin_lock_init(&nc_path
->packet_list_lock
);
979 kref_init(&nc_path
->refcount
);
980 kref_get(&nc_path
->refcount
);
981 nc_path
->last_valid
= jiffies
;
982 ether_addr_copy(nc_path
->next_hop
, dst
);
983 ether_addr_copy(nc_path
->prev_hop
, src
);
985 batadv_dbg(BATADV_DBG_NC
, bat_priv
, "Adding nc_path %pM -> %pM\n",
989 /* Add nc_path to hash table */
990 hash_added
= batadv_hash_add(hash
, batadv_nc_hash_compare
,
991 batadv_nc_hash_choose
, &nc_path_key
,
992 &nc_path
->hash_entry
);
994 if (hash_added
< 0) {
1003 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
1004 * selection of a receiver with slightly lower TQ than the other
1005 * @tq: to be weighted tq value
1007 * Return: scaled tq value
1009 static u8
batadv_nc_random_weight_tq(u8 tq
)
1011 u8 rand_val
, rand_tq
;
1013 get_random_bytes(&rand_val
, sizeof(rand_val
));
1015 /* randomize the estimated packet loss (max TQ - estimated TQ) */
1016 rand_tq
= rand_val
* (BATADV_TQ_MAX_VALUE
- tq
);
1018 /* normalize the randomized packet loss */
1019 rand_tq
/= BATADV_TQ_MAX_VALUE
;
1021 /* convert to (randomized) estimated tq again */
1022 return BATADV_TQ_MAX_VALUE
- rand_tq
;
1026 * batadv_nc_memxor - XOR destination with source
1027 * @dst: byte array to XOR into
1028 * @src: byte array to XOR from
1029 * @len: length of destination array
1031 static void batadv_nc_memxor(char *dst
, const char *src
, unsigned int len
)
1035 for (i
= 0; i
< len
; ++i
)
1040 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
1041 * into a coded_packet and send it
1042 * @bat_priv: the bat priv with all the soft interface information
1043 * @skb: data skb to forward
1044 * @ethhdr: pointer to the ethernet header inside the skb
1045 * @nc_packet: structure containing the packet to the skb can be coded with
1046 * @neigh_node: next hop to forward packet to
1048 * Return: true if both packets are consumed, false otherwise.
1050 static bool batadv_nc_code_packets(struct batadv_priv
*bat_priv
,
1051 struct sk_buff
*skb
,
1052 struct ethhdr
*ethhdr
,
1053 struct batadv_nc_packet
*nc_packet
,
1054 struct batadv_neigh_node
*neigh_node
)
1056 u8 tq_weighted_neigh
, tq_weighted_coding
, tq_tmp
;
1057 struct sk_buff
*skb_dest
, *skb_src
;
1058 struct batadv_unicast_packet
*packet1
;
1059 struct batadv_unicast_packet
*packet2
;
1060 struct batadv_coded_packet
*coded_packet
;
1061 struct batadv_neigh_node
*neigh_tmp
, *router_neigh
, *first_dest
;
1062 struct batadv_neigh_node
*router_coding
= NULL
, *second_dest
;
1063 struct batadv_neigh_ifinfo
*router_neigh_ifinfo
= NULL
;
1064 struct batadv_neigh_ifinfo
*router_coding_ifinfo
= NULL
;
1065 u8
*first_source
, *second_source
;
1066 __be32 packet_id1
, packet_id2
;
1070 int unicast_size
= sizeof(*packet1
);
1071 int coded_size
= sizeof(*coded_packet
);
1072 int header_add
= coded_size
- unicast_size
;
1074 /* TODO: do we need to consider the outgoing interface for
1077 router_neigh
= batadv_orig_router_get(neigh_node
->orig_node
,
1082 router_neigh_ifinfo
= batadv_neigh_ifinfo_get(router_neigh
,
1084 if (!router_neigh_ifinfo
)
1087 neigh_tmp
= nc_packet
->neigh_node
;
1088 router_coding
= batadv_orig_router_get(neigh_tmp
->orig_node
,
1093 router_coding_ifinfo
= batadv_neigh_ifinfo_get(router_coding
,
1095 if (!router_coding_ifinfo
)
1098 tq_tmp
= router_neigh_ifinfo
->bat_iv
.tq_avg
;
1099 tq_weighted_neigh
= batadv_nc_random_weight_tq(tq_tmp
);
1100 tq_tmp
= router_coding_ifinfo
->bat_iv
.tq_avg
;
1101 tq_weighted_coding
= batadv_nc_random_weight_tq(tq_tmp
);
1103 /* Select one destination for the MAC-header dst-field based on
1104 * weighted TQ-values.
1106 if (tq_weighted_neigh
>= tq_weighted_coding
) {
1107 /* Destination from nc_packet is selected for MAC-header */
1108 first_dest
= nc_packet
->neigh_node
;
1109 first_source
= nc_packet
->nc_path
->prev_hop
;
1110 second_dest
= neigh_node
;
1111 second_source
= ethhdr
->h_source
;
1112 packet1
= (struct batadv_unicast_packet
*)nc_packet
->skb
->data
;
1113 packet2
= (struct batadv_unicast_packet
*)skb
->data
;
1114 packet_id1
= nc_packet
->packet_id
;
1115 packet_id2
= batadv_skb_crc32(skb
,
1116 skb
->data
+ sizeof(*packet2
));
1118 /* Destination for skb is selected for MAC-header */
1119 first_dest
= neigh_node
;
1120 first_source
= ethhdr
->h_source
;
1121 second_dest
= nc_packet
->neigh_node
;
1122 second_source
= nc_packet
->nc_path
->prev_hop
;
1123 packet1
= (struct batadv_unicast_packet
*)skb
->data
;
1124 packet2
= (struct batadv_unicast_packet
*)nc_packet
->skb
->data
;
1125 packet_id1
= batadv_skb_crc32(skb
,
1126 skb
->data
+ sizeof(*packet1
));
1127 packet_id2
= nc_packet
->packet_id
;
1130 /* Instead of zero padding the smallest data buffer, we
1131 * code into the largest.
1133 if (skb
->len
<= nc_packet
->skb
->len
) {
1134 skb_dest
= nc_packet
->skb
;
1138 skb_src
= nc_packet
->skb
;
1141 /* coding_len is used when decoding the packet shorter packet */
1142 coding_len
= skb_src
->len
- unicast_size
;
1144 if (skb_linearize(skb_dest
) < 0 || skb_linearize(skb_src
) < 0)
1147 skb_push(skb_dest
, header_add
);
1149 coded_packet
= (struct batadv_coded_packet
*)skb_dest
->data
;
1150 skb_reset_mac_header(skb_dest
);
1152 coded_packet
->packet_type
= BATADV_CODED
;
1153 coded_packet
->version
= BATADV_COMPAT_VERSION
;
1154 coded_packet
->ttl
= packet1
->ttl
;
1156 /* Info about first unicast packet */
1157 ether_addr_copy(coded_packet
->first_source
, first_source
);
1158 ether_addr_copy(coded_packet
->first_orig_dest
, packet1
->dest
);
1159 coded_packet
->first_crc
= packet_id1
;
1160 coded_packet
->first_ttvn
= packet1
->ttvn
;
1162 /* Info about second unicast packet */
1163 ether_addr_copy(coded_packet
->second_dest
, second_dest
->addr
);
1164 ether_addr_copy(coded_packet
->second_source
, second_source
);
1165 ether_addr_copy(coded_packet
->second_orig_dest
, packet2
->dest
);
1166 coded_packet
->second_crc
= packet_id2
;
1167 coded_packet
->second_ttl
= packet2
->ttl
;
1168 coded_packet
->second_ttvn
= packet2
->ttvn
;
1169 coded_packet
->coded_len
= htons(coding_len
);
1171 /* This is where the magic happens: Code skb_src into skb_dest */
1172 batadv_nc_memxor(skb_dest
->data
+ coded_size
,
1173 skb_src
->data
+ unicast_size
, coding_len
);
1175 /* Update counters accordingly */
1176 if (BATADV_SKB_CB(skb_src
)->decoded
&&
1177 BATADV_SKB_CB(skb_dest
)->decoded
) {
1178 /* Both packets are recoded */
1179 count
= skb_src
->len
+ ETH_HLEN
;
1180 count
+= skb_dest
->len
+ ETH_HLEN
;
1181 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE
, 2);
1182 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
, count
);
1183 } else if (!BATADV_SKB_CB(skb_src
)->decoded
&&
1184 !BATADV_SKB_CB(skb_dest
)->decoded
) {
1185 /* Both packets are newly coded */
1186 count
= skb_src
->len
+ ETH_HLEN
;
1187 count
+= skb_dest
->len
+ ETH_HLEN
;
1188 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE
, 2);
1189 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
, count
);
1190 } else if (BATADV_SKB_CB(skb_src
)->decoded
&&
1191 !BATADV_SKB_CB(skb_dest
)->decoded
) {
1192 /* skb_src recoded and skb_dest is newly coded */
1193 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_RECODE
);
1194 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
,
1195 skb_src
->len
+ ETH_HLEN
);
1196 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_CODE
);
1197 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
,
1198 skb_dest
->len
+ ETH_HLEN
);
1199 } else if (!BATADV_SKB_CB(skb_src
)->decoded
&&
1200 BATADV_SKB_CB(skb_dest
)->decoded
) {
1201 /* skb_src is newly coded and skb_dest is recoded */
1202 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_CODE
);
1203 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
,
1204 skb_src
->len
+ ETH_HLEN
);
1205 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_RECODE
);
1206 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
,
1207 skb_dest
->len
+ ETH_HLEN
);
1210 /* skb_src is now coded into skb_dest, so free it */
1213 /* avoid duplicate free of skb from nc_packet */
1214 nc_packet
->skb
= NULL
;
1215 batadv_nc_packet_free(nc_packet
);
1217 /* Send the coded packet and return true */
1218 batadv_send_unicast_skb(skb_dest
, first_dest
);
1222 batadv_neigh_node_put(router_neigh
);
1224 batadv_neigh_node_put(router_coding
);
1225 if (router_neigh_ifinfo
)
1226 batadv_neigh_ifinfo_put(router_neigh_ifinfo
);
1227 if (router_coding_ifinfo
)
1228 batadv_neigh_ifinfo_put(router_coding_ifinfo
);
1233 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1234 * @skb: data skb to forward
1235 * @dst: destination mac address of the other skb to code with
1236 * @src: source mac address of skb
1238 * Whenever we network code a packet we have to check whether we received it in
1239 * a network coded form. If so, we may not be able to use it for coding because
1240 * some neighbors may also have received (overheard) the packet in the network
1241 * coded form without being able to decode it. It is hard to know which of the
1242 * neighboring nodes was able to decode the packet, therefore we can only
1243 * re-code the packet if the source of the previous encoded packet is involved.
1244 * Since the source encoded the packet we can be certain it has all necessary
1245 * decode information.
1247 * Return: true if coding of a decoded packet is allowed.
1249 static bool batadv_nc_skb_coding_possible(struct sk_buff
*skb
, u8
*dst
, u8
*src
)
1251 if (BATADV_SKB_CB(skb
)->decoded
&& !batadv_compare_eth(dst
, src
))
1257 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1258 * out_nc_node to retrieve a buffered packet that can be used for coding.
1259 * @bat_priv: the bat priv with all the soft interface information
1260 * @in_nc_node: pointer to skb next hop's neighbor nc node
1261 * @out_nc_node: pointer to skb source's neighbor nc node
1262 * @skb: data skb to forward
1263 * @eth_dst: next hop mac address of skb
1265 * Return: true if coding of a decoded skb is allowed.
1267 static struct batadv_nc_packet
*
1268 batadv_nc_path_search(struct batadv_priv
*bat_priv
,
1269 struct batadv_nc_node
*in_nc_node
,
1270 struct batadv_nc_node
*out_nc_node
,
1271 struct sk_buff
*skb
,
1274 struct batadv_nc_path
*nc_path
, nc_path_key
;
1275 struct batadv_nc_packet
*nc_packet_out
= NULL
;
1276 struct batadv_nc_packet
*nc_packet
, *nc_packet_tmp
;
1277 struct batadv_hashtable
*hash
= bat_priv
->nc
.coding_hash
;
1283 /* Create almost path key */
1284 batadv_nc_hash_key_gen(&nc_path_key
, in_nc_node
->addr
,
1286 idx
= batadv_nc_hash_choose(&nc_path_key
, hash
->size
);
1288 /* Check for coding opportunities in this nc_path */
1290 hlist_for_each_entry_rcu(nc_path
, &hash
->table
[idx
], hash_entry
) {
1291 if (!batadv_compare_eth(nc_path
->prev_hop
, in_nc_node
->addr
))
1294 if (!batadv_compare_eth(nc_path
->next_hop
, out_nc_node
->addr
))
1297 spin_lock_bh(&nc_path
->packet_list_lock
);
1298 if (list_empty(&nc_path
->packet_list
)) {
1299 spin_unlock_bh(&nc_path
->packet_list_lock
);
1303 list_for_each_entry_safe(nc_packet
, nc_packet_tmp
,
1304 &nc_path
->packet_list
, list
) {
1305 if (!batadv_nc_skb_coding_possible(nc_packet
->skb
,
1310 /* Coding opportunity is found! */
1311 list_del(&nc_packet
->list
);
1312 nc_packet_out
= nc_packet
;
1316 spin_unlock_bh(&nc_path
->packet_list_lock
);
1321 return nc_packet_out
;
1325 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1326 * skb's sender (may be equal to the originator).
1327 * @bat_priv: the bat priv with all the soft interface information
1328 * @skb: data skb to forward
1329 * @eth_dst: next hop mac address of skb
1330 * @eth_src: source mac address of skb
1331 * @in_nc_node: pointer to skb next hop's neighbor nc node
1333 * Return: an nc packet if a suitable coding packet was found, NULL otherwise.
1335 static struct batadv_nc_packet
*
1336 batadv_nc_skb_src_search(struct batadv_priv
*bat_priv
,
1337 struct sk_buff
*skb
,
1340 struct batadv_nc_node
*in_nc_node
)
1342 struct batadv_orig_node
*orig_node
;
1343 struct batadv_nc_node
*out_nc_node
;
1344 struct batadv_nc_packet
*nc_packet
= NULL
;
1346 orig_node
= batadv_orig_hash_find(bat_priv
, eth_src
);
1351 list_for_each_entry_rcu(out_nc_node
,
1352 &orig_node
->out_coding_list
, list
) {
1353 /* Check if the skb is decoded and if recoding is possible */
1354 if (!batadv_nc_skb_coding_possible(skb
,
1355 out_nc_node
->addr
, eth_src
))
1358 /* Search for an opportunity in this nc_path */
1359 nc_packet
= batadv_nc_path_search(bat_priv
, in_nc_node
,
1360 out_nc_node
, skb
, eth_dst
);
1366 batadv_orig_node_put(orig_node
);
1371 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1372 * unicast skb before it is stored for use in later decoding
1373 * @bat_priv: the bat priv with all the soft interface information
1374 * @skb: data skb to store
1375 * @eth_dst_new: new destination mac address of skb
1377 static void batadv_nc_skb_store_before_coding(struct batadv_priv
*bat_priv
,
1378 struct sk_buff
*skb
,
1381 struct ethhdr
*ethhdr
;
1383 /* Copy skb header to change the mac header */
1384 skb
= pskb_copy_for_clone(skb
, GFP_ATOMIC
);
1388 /* Set the mac header as if we actually sent the packet uncoded */
1389 ethhdr
= eth_hdr(skb
);
1390 ether_addr_copy(ethhdr
->h_source
, ethhdr
->h_dest
);
1391 ether_addr_copy(ethhdr
->h_dest
, eth_dst_new
);
1393 /* Set data pointer to MAC header to mimic packets from our tx path */
1394 skb_push(skb
, ETH_HLEN
);
1396 /* Add the packet to the decoding packet pool */
1397 batadv_nc_skb_store_for_decoding(bat_priv
, skb
);
1399 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1406 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1407 * @skb: data skb to forward
1408 * @neigh_node: next hop to forward packet to
1409 * @ethhdr: pointer to the ethernet header inside the skb
1411 * Loops through list of neighboring nodes the next hop has a good connection to
1412 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1413 * next hop that potentially sent a packet which our next hop also received
1414 * (overheard) and has stored for later decoding.
1416 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1418 static bool batadv_nc_skb_dst_search(struct sk_buff
*skb
,
1419 struct batadv_neigh_node
*neigh_node
,
1420 struct ethhdr
*ethhdr
)
1422 struct net_device
*netdev
= neigh_node
->if_incoming
->soft_iface
;
1423 struct batadv_priv
*bat_priv
= netdev_priv(netdev
);
1424 struct batadv_orig_node
*orig_node
= neigh_node
->orig_node
;
1425 struct batadv_nc_node
*nc_node
;
1426 struct batadv_nc_packet
*nc_packet
= NULL
;
1429 list_for_each_entry_rcu(nc_node
, &orig_node
->in_coding_list
, list
) {
1430 /* Search for coding opportunity with this in_nc_node */
1431 nc_packet
= batadv_nc_skb_src_search(bat_priv
, skb
,
1433 ethhdr
->h_source
, nc_node
);
1435 /* Opportunity was found, so stop searching */
1444 /* Save packets for later decoding */
1445 batadv_nc_skb_store_before_coding(bat_priv
, skb
,
1447 batadv_nc_skb_store_before_coding(bat_priv
, nc_packet
->skb
,
1448 nc_packet
->neigh_node
->addr
);
1450 /* Code and send packets */
1451 if (batadv_nc_code_packets(bat_priv
, skb
, ethhdr
, nc_packet
,
1455 /* out of mem ? Coding failed - we have to free the buffered packet
1456 * to avoid memleaks. The skb passed as argument will be dealt with
1457 * by the calling function.
1459 batadv_nc_send_packet(nc_packet
);
1464 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1465 * @skb: skb to add to path
1466 * @nc_path: path to add skb to
1467 * @neigh_node: next hop to forward packet to
1468 * @packet_id: checksum to identify packet
1470 * Return: true if the packet was buffered or false in case of an error.
1472 static bool batadv_nc_skb_add_to_path(struct sk_buff
*skb
,
1473 struct batadv_nc_path
*nc_path
,
1474 struct batadv_neigh_node
*neigh_node
,
1477 struct batadv_nc_packet
*nc_packet
;
1479 nc_packet
= kzalloc(sizeof(*nc_packet
), GFP_ATOMIC
);
1483 /* Initialize nc_packet */
1484 nc_packet
->timestamp
= jiffies
;
1485 nc_packet
->packet_id
= packet_id
;
1486 nc_packet
->skb
= skb
;
1487 nc_packet
->neigh_node
= neigh_node
;
1488 nc_packet
->nc_path
= nc_path
;
1490 /* Add coding packet to list */
1491 spin_lock_bh(&nc_path
->packet_list_lock
);
1492 list_add_tail(&nc_packet
->list
, &nc_path
->packet_list
);
1493 spin_unlock_bh(&nc_path
->packet_list_lock
);
1499 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1501 * @skb: data skb to forward
1502 * @neigh_node: next hop to forward packet to
1504 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1506 bool batadv_nc_skb_forward(struct sk_buff
*skb
,
1507 struct batadv_neigh_node
*neigh_node
)
1509 const struct net_device
*netdev
= neigh_node
->if_incoming
->soft_iface
;
1510 struct batadv_priv
*bat_priv
= netdev_priv(netdev
);
1511 struct batadv_unicast_packet
*packet
;
1512 struct batadv_nc_path
*nc_path
;
1513 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1517 /* Check if network coding is enabled */
1518 if (!atomic_read(&bat_priv
->network_coding
))
1521 /* We only handle unicast packets */
1522 payload
= skb_network_header(skb
);
1523 packet
= (struct batadv_unicast_packet
*)payload
;
1524 if (packet
->packet_type
!= BATADV_UNICAST
)
1527 /* Try to find a coding opportunity and send the skb if one is found */
1528 if (batadv_nc_skb_dst_search(skb
, neigh_node
, ethhdr
))
1531 /* Find or create a nc_path for this src-dst pair */
1532 nc_path
= batadv_nc_get_path(bat_priv
,
1533 bat_priv
->nc
.coding_hash
,
1540 /* Add skb to nc_path */
1541 packet_id
= batadv_skb_crc32(skb
, payload
+ sizeof(*packet
));
1542 if (!batadv_nc_skb_add_to_path(skb
, nc_path
, neigh_node
, packet_id
))
1545 /* Packet is consumed */
1549 batadv_nc_path_put(nc_path
);
1551 /* Packet is not consumed */
1556 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1557 * when decoding coded packets
1558 * @bat_priv: the bat priv with all the soft interface information
1559 * @skb: data skb to store
1561 void batadv_nc_skb_store_for_decoding(struct batadv_priv
*bat_priv
,
1562 struct sk_buff
*skb
)
1564 struct batadv_unicast_packet
*packet
;
1565 struct batadv_nc_path
*nc_path
;
1566 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1570 /* Check if network coding is enabled */
1571 if (!atomic_read(&bat_priv
->network_coding
))
1574 /* Check for supported packet type */
1575 payload
= skb_network_header(skb
);
1576 packet
= (struct batadv_unicast_packet
*)payload
;
1577 if (packet
->packet_type
!= BATADV_UNICAST
)
1580 /* Find existing nc_path or create a new */
1581 nc_path
= batadv_nc_get_path(bat_priv
,
1582 bat_priv
->nc
.decoding_hash
,
1589 /* Clone skb and adjust skb->data to point at batman header */
1590 skb
= skb_clone(skb
, GFP_ATOMIC
);
1594 if (unlikely(!pskb_may_pull(skb
, ETH_HLEN
)))
1597 if (unlikely(!skb_pull_rcsum(skb
, ETH_HLEN
)))
1600 /* Add skb to nc_path */
1601 packet_id
= batadv_skb_crc32(skb
, payload
+ sizeof(*packet
));
1602 if (!batadv_nc_skb_add_to_path(skb
, nc_path
, NULL
, packet_id
))
1605 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_BUFFER
);
1611 batadv_nc_path_put(nc_path
);
1617 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1618 * should be saved in the decoding buffer and, if so, store it there
1619 * @bat_priv: the bat priv with all the soft interface information
1620 * @skb: unicast skb to store
1622 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv
*bat_priv
,
1623 struct sk_buff
*skb
)
1625 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1627 if (batadv_is_my_mac(bat_priv
, ethhdr
->h_dest
))
1630 /* Set data pointer to MAC header to mimic packets from our tx path */
1631 skb_push(skb
, ETH_HLEN
);
1633 batadv_nc_skb_store_for_decoding(bat_priv
, skb
);
1637 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1639 * @bat_priv: the bat priv with all the soft interface information
1640 * @skb: unicast skb to decode
1641 * @nc_packet: decode data needed to decode the skb
1643 * Return: pointer to decoded unicast packet if the packet was decoded or NULL
1644 * in case of an error.
1646 static struct batadv_unicast_packet
*
1647 batadv_nc_skb_decode_packet(struct batadv_priv
*bat_priv
, struct sk_buff
*skb
,
1648 struct batadv_nc_packet
*nc_packet
)
1650 const int h_size
= sizeof(struct batadv_unicast_packet
);
1651 const int h_diff
= sizeof(struct batadv_coded_packet
) - h_size
;
1652 struct batadv_unicast_packet
*unicast_packet
;
1653 struct batadv_coded_packet coded_packet_tmp
;
1654 struct ethhdr
*ethhdr
, ethhdr_tmp
;
1655 u8
*orig_dest
, ttl
, ttvn
;
1656 unsigned int coding_len
;
1659 /* Save headers temporarily */
1660 memcpy(&coded_packet_tmp
, skb
->data
, sizeof(coded_packet_tmp
));
1661 memcpy(ðhdr_tmp
, skb_mac_header(skb
), sizeof(ethhdr_tmp
));
1663 if (skb_cow(skb
, 0) < 0)
1666 if (unlikely(!skb_pull_rcsum(skb
, h_diff
)))
1669 /* Data points to batman header, so set mac header 14 bytes before
1670 * and network to data
1672 skb_set_mac_header(skb
, -ETH_HLEN
);
1673 skb_reset_network_header(skb
);
1675 /* Reconstruct original mac header */
1676 ethhdr
= eth_hdr(skb
);
1677 *ethhdr
= ethhdr_tmp
;
1679 /* Select the correct unicast header information based on the location
1680 * of our mac address in the coded_packet header
1682 if (batadv_is_my_mac(bat_priv
, coded_packet_tmp
.second_dest
)) {
1683 /* If we are the second destination the packet was overheard,
1684 * so the Ethernet address must be copied to h_dest and
1685 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1687 ether_addr_copy(ethhdr
->h_dest
, coded_packet_tmp
.second_dest
);
1688 skb
->pkt_type
= PACKET_HOST
;
1690 orig_dest
= coded_packet_tmp
.second_orig_dest
;
1691 ttl
= coded_packet_tmp
.second_ttl
;
1692 ttvn
= coded_packet_tmp
.second_ttvn
;
1694 orig_dest
= coded_packet_tmp
.first_orig_dest
;
1695 ttl
= coded_packet_tmp
.ttl
;
1696 ttvn
= coded_packet_tmp
.first_ttvn
;
1699 coding_len
= ntohs(coded_packet_tmp
.coded_len
);
1701 if (coding_len
> skb
->len
)
1704 /* Here the magic is reversed:
1705 * extract the missing packet from the received coded packet
1707 batadv_nc_memxor(skb
->data
+ h_size
,
1708 nc_packet
->skb
->data
+ h_size
,
1711 /* Resize decoded skb if decoded with larger packet */
1712 if (nc_packet
->skb
->len
> coding_len
+ h_size
) {
1713 err
= pskb_trim_rcsum(skb
, coding_len
+ h_size
);
1718 /* Create decoded unicast packet */
1719 unicast_packet
= (struct batadv_unicast_packet
*)skb
->data
;
1720 unicast_packet
->packet_type
= BATADV_UNICAST
;
1721 unicast_packet
->version
= BATADV_COMPAT_VERSION
;
1722 unicast_packet
->ttl
= ttl
;
1723 ether_addr_copy(unicast_packet
->dest
, orig_dest
);
1724 unicast_packet
->ttvn
= ttvn
;
1726 batadv_nc_packet_free(nc_packet
);
1727 return unicast_packet
;
1731 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1732 * find the data needed to decode the coded packet
1733 * @bat_priv: the bat priv with all the soft interface information
1734 * @ethhdr: pointer to the ethernet header inside the coded packet
1735 * @coded: coded packet we try to find decode data for
1737 * Return: pointer to nc packet if the needed data was found or NULL otherwise.
1739 static struct batadv_nc_packet
*
1740 batadv_nc_find_decoding_packet(struct batadv_priv
*bat_priv
,
1741 struct ethhdr
*ethhdr
,
1742 struct batadv_coded_packet
*coded
)
1744 struct batadv_hashtable
*hash
= bat_priv
->nc
.decoding_hash
;
1745 struct batadv_nc_packet
*tmp_nc_packet
, *nc_packet
= NULL
;
1746 struct batadv_nc_path
*nc_path
, nc_path_key
;
1754 /* Select the correct packet id based on the location of our mac-addr */
1755 dest
= ethhdr
->h_source
;
1756 if (!batadv_is_my_mac(bat_priv
, coded
->second_dest
)) {
1757 source
= coded
->second_source
;
1758 packet_id
= coded
->second_crc
;
1760 source
= coded
->first_source
;
1761 packet_id
= coded
->first_crc
;
1764 batadv_nc_hash_key_gen(&nc_path_key
, source
, dest
);
1765 index
= batadv_nc_hash_choose(&nc_path_key
, hash
->size
);
1767 /* Search for matching coding path */
1769 hlist_for_each_entry_rcu(nc_path
, &hash
->table
[index
], hash_entry
) {
1770 /* Find matching nc_packet */
1771 spin_lock_bh(&nc_path
->packet_list_lock
);
1772 list_for_each_entry(tmp_nc_packet
,
1773 &nc_path
->packet_list
, list
) {
1774 if (packet_id
== tmp_nc_packet
->packet_id
) {
1775 list_del(&tmp_nc_packet
->list
);
1777 nc_packet
= tmp_nc_packet
;
1781 spin_unlock_bh(&nc_path
->packet_list_lock
);
1789 batadv_dbg(BATADV_DBG_NC
, bat_priv
,
1790 "No decoding packet found for %u\n", packet_id
);
1796 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1797 * resulting unicast packet
1798 * @skb: incoming coded packet
1799 * @recv_if: pointer to interface this packet was received on
1801 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1804 static int batadv_nc_recv_coded_packet(struct sk_buff
*skb
,
1805 struct batadv_hard_iface
*recv_if
)
1807 struct batadv_priv
*bat_priv
= netdev_priv(recv_if
->soft_iface
);
1808 struct batadv_unicast_packet
*unicast_packet
;
1809 struct batadv_coded_packet
*coded_packet
;
1810 struct batadv_nc_packet
*nc_packet
;
1811 struct ethhdr
*ethhdr
;
1812 int hdr_size
= sizeof(*coded_packet
);
1814 /* Check if network coding is enabled */
1815 if (!atomic_read(&bat_priv
->network_coding
))
1818 /* Make sure we can access (and remove) header */
1819 if (unlikely(!pskb_may_pull(skb
, hdr_size
)))
1822 coded_packet
= (struct batadv_coded_packet
*)skb
->data
;
1823 ethhdr
= eth_hdr(skb
);
1825 /* Verify frame is destined for us */
1826 if (!batadv_is_my_mac(bat_priv
, ethhdr
->h_dest
) &&
1827 !batadv_is_my_mac(bat_priv
, coded_packet
->second_dest
))
1830 /* Update stat counter */
1831 if (batadv_is_my_mac(bat_priv
, coded_packet
->second_dest
))
1832 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_SNIFFED
);
1834 nc_packet
= batadv_nc_find_decoding_packet(bat_priv
, ethhdr
,
1837 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE_FAILED
);
1841 /* Make skb's linear, because decoding accesses the entire buffer */
1842 if (skb_linearize(skb
) < 0)
1843 goto free_nc_packet
;
1845 if (skb_linearize(nc_packet
->skb
) < 0)
1846 goto free_nc_packet
;
1848 /* Decode the packet */
1849 unicast_packet
= batadv_nc_skb_decode_packet(bat_priv
, skb
, nc_packet
);
1850 if (!unicast_packet
) {
1851 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE_FAILED
);
1852 goto free_nc_packet
;
1855 /* Mark packet as decoded to do correct recoding when forwarding */
1856 BATADV_SKB_CB(skb
)->decoded
= true;
1857 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE
);
1858 batadv_add_counter(bat_priv
, BATADV_CNT_NC_DECODE_BYTES
,
1859 skb
->len
+ ETH_HLEN
);
1860 return batadv_recv_unicast_packet(skb
, recv_if
);
1863 batadv_nc_packet_free(nc_packet
);
1868 * batadv_nc_mesh_free - clean up network coding memory
1869 * @bat_priv: the bat priv with all the soft interface information
1871 void batadv_nc_mesh_free(struct batadv_priv
*bat_priv
)
1873 batadv_tvlv_container_unregister(bat_priv
, BATADV_TVLV_NC
, 1);
1874 batadv_tvlv_handler_unregister(bat_priv
, BATADV_TVLV_NC
, 1);
1875 cancel_delayed_work_sync(&bat_priv
->nc
.work
);
1877 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.coding_hash
, NULL
);
1878 batadv_hash_destroy(bat_priv
->nc
.coding_hash
);
1879 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.decoding_hash
, NULL
);
1880 batadv_hash_destroy(bat_priv
->nc
.decoding_hash
);
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
);