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_free_ref - decrement the nc_node refcounter and possibly
228 * @nc_node: nc_node to be free'd
230 static void batadv_nc_node_free_ref(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_free_ref - decrement the nc_path refcounter and possibly
252 * @nc_path: nc_path to be free'd
254 static void batadv_nc_path_free_ref(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_free_ref(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_free_ref(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_free_ref(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: 1 if the two entry are the same, 0 otherwise
515 static int 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 (memcmp(nc_path1
->prev_hop
, nc_path2
->prev_hop
,
525 sizeof(nc_path1
->prev_hop
)) != 0)
528 if (memcmp(nc_path1
->next_hop
, nc_path2
->next_hop
,
529 sizeof(nc_path1
->next_hop
)) != 0)
536 * batadv_nc_hash_find - search for an existing nc path and return it
537 * @hash: hash table containing the nc path
540 * Return: the nc_path if found, NULL otherwise.
542 static struct batadv_nc_path
*
543 batadv_nc_hash_find(struct batadv_hashtable
*hash
,
546 struct hlist_head
*head
;
547 struct batadv_nc_path
*nc_path
, *nc_path_tmp
= NULL
;
553 index
= batadv_nc_hash_choose(data
, hash
->size
);
554 head
= &hash
->table
[index
];
557 hlist_for_each_entry_rcu(nc_path
, head
, hash_entry
) {
558 if (!batadv_nc_hash_compare(&nc_path
->hash_entry
, data
))
561 if (!kref_get_unless_zero(&nc_path
->refcount
))
564 nc_path_tmp
= nc_path
;
573 * batadv_nc_send_packet - send non-coded packet and free nc_packet struct
574 * @nc_packet: the nc packet to send
576 static void batadv_nc_send_packet(struct batadv_nc_packet
*nc_packet
)
578 batadv_send_skb_packet(nc_packet
->skb
,
579 nc_packet
->neigh_node
->if_incoming
,
580 nc_packet
->nc_path
->next_hop
);
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
= container_of(work
, struct 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_free_ref(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 /* Check if nc_node is already added */
851 nc_node
= batadv_nc_find_nc_node(orig_node
, orig_neigh_node
, in_coding
);
857 nc_node
= kzalloc(sizeof(*nc_node
), GFP_ATOMIC
);
861 if (!kref_get_unless_zero(&orig_neigh_node
->refcount
))
864 /* Initialize nc_node */
865 INIT_LIST_HEAD(&nc_node
->list
);
866 ether_addr_copy(nc_node
->addr
, orig_node
->orig
);
867 nc_node
->orig_node
= orig_neigh_node
;
868 kref_init(&nc_node
->refcount
);
869 kref_get(&nc_node
->refcount
);
871 /* Select ingoing or outgoing coding node */
873 lock
= &orig_neigh_node
->in_coding_list_lock
;
874 list
= &orig_neigh_node
->in_coding_list
;
876 lock
= &orig_neigh_node
->out_coding_list_lock
;
877 list
= &orig_neigh_node
->out_coding_list
;
880 batadv_dbg(BATADV_DBG_NC
, bat_priv
, "Adding nc_node %pM -> %pM\n",
881 nc_node
->addr
, nc_node
->orig_node
->orig
);
883 /* Add nc_node to orig_node */
885 list_add_tail_rcu(&nc_node
->list
, list
);
886 spin_unlock_bh(lock
);
896 * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node
897 * structs (best called on incoming OGMs)
898 * @bat_priv: the bat priv with all the soft interface information
899 * @orig_node: orig node originating the ogm packet
900 * @orig_neigh_node: neighboring orig node from which we received the ogm packet
901 * (can be equal to orig_node)
902 * @ogm_packet: incoming ogm packet
903 * @is_single_hop_neigh: orig_node is a single hop neighbor
905 void batadv_nc_update_nc_node(struct batadv_priv
*bat_priv
,
906 struct batadv_orig_node
*orig_node
,
907 struct batadv_orig_node
*orig_neigh_node
,
908 struct batadv_ogm_packet
*ogm_packet
,
909 int is_single_hop_neigh
)
911 struct batadv_nc_node
*in_nc_node
= NULL
;
912 struct batadv_nc_node
*out_nc_node
= NULL
;
914 /* Check if network coding is enabled */
915 if (!atomic_read(&bat_priv
->network_coding
))
918 /* check if orig node is network coding enabled */
919 if (!test_bit(BATADV_ORIG_CAPA_HAS_NC
, &orig_node
->capabilities
))
922 /* accept ogms from 'good' neighbors and single hop neighbors */
923 if (!batadv_can_nc_with_orig(bat_priv
, orig_node
, ogm_packet
) &&
924 !is_single_hop_neigh
)
927 /* Add orig_node as in_nc_node on hop */
928 in_nc_node
= batadv_nc_get_nc_node(bat_priv
, orig_node
,
929 orig_neigh_node
, true);
933 in_nc_node
->last_seen
= jiffies
;
935 /* Add hop as out_nc_node on orig_node */
936 out_nc_node
= batadv_nc_get_nc_node(bat_priv
, orig_neigh_node
,
941 out_nc_node
->last_seen
= jiffies
;
945 batadv_nc_node_free_ref(in_nc_node
);
947 batadv_nc_node_free_ref(out_nc_node
);
951 * batadv_nc_get_path - get existing nc_path or allocate a new one
952 * @bat_priv: the bat priv with all the soft interface information
953 * @hash: hash table containing the nc path
954 * @src: ethernet source address - first half of the nc path search key
955 * @dst: ethernet destination address - second half of the nc path search key
957 * Return: pointer to nc_path if the path was found or created, returns NULL
960 static struct batadv_nc_path
*batadv_nc_get_path(struct batadv_priv
*bat_priv
,
961 struct batadv_hashtable
*hash
,
966 struct batadv_nc_path
*nc_path
, nc_path_key
;
968 batadv_nc_hash_key_gen(&nc_path_key
, src
, dst
);
970 /* Search for existing nc_path */
971 nc_path
= batadv_nc_hash_find(hash
, (void *)&nc_path_key
);
974 /* Set timestamp to delay removal of nc_path */
975 nc_path
->last_valid
= jiffies
;
979 /* No existing nc_path was found; create a new */
980 nc_path
= kzalloc(sizeof(*nc_path
), GFP_ATOMIC
);
985 /* Initialize nc_path */
986 INIT_LIST_HEAD(&nc_path
->packet_list
);
987 spin_lock_init(&nc_path
->packet_list_lock
);
988 kref_init(&nc_path
->refcount
);
989 kref_get(&nc_path
->refcount
);
990 nc_path
->last_valid
= jiffies
;
991 ether_addr_copy(nc_path
->next_hop
, dst
);
992 ether_addr_copy(nc_path
->prev_hop
, src
);
994 batadv_dbg(BATADV_DBG_NC
, bat_priv
, "Adding nc_path %pM -> %pM\n",
998 /* Add nc_path to hash table */
999 hash_added
= batadv_hash_add(hash
, batadv_nc_hash_compare
,
1000 batadv_nc_hash_choose
, &nc_path_key
,
1001 &nc_path
->hash_entry
);
1003 if (hash_added
< 0) {
1012 * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
1013 * selection of a receiver with slightly lower TQ than the other
1014 * @tq: to be weighted tq value
1016 * Return: scaled tq value
1018 static u8
batadv_nc_random_weight_tq(u8 tq
)
1020 u8 rand_val
, rand_tq
;
1022 get_random_bytes(&rand_val
, sizeof(rand_val
));
1024 /* randomize the estimated packet loss (max TQ - estimated TQ) */
1025 rand_tq
= rand_val
* (BATADV_TQ_MAX_VALUE
- tq
);
1027 /* normalize the randomized packet loss */
1028 rand_tq
/= BATADV_TQ_MAX_VALUE
;
1030 /* convert to (randomized) estimated tq again */
1031 return BATADV_TQ_MAX_VALUE
- rand_tq
;
1035 * batadv_nc_memxor - XOR destination with source
1036 * @dst: byte array to XOR into
1037 * @src: byte array to XOR from
1038 * @len: length of destination array
1040 static void batadv_nc_memxor(char *dst
, const char *src
, unsigned int len
)
1044 for (i
= 0; i
< len
; ++i
)
1049 * batadv_nc_code_packets - code a received unicast_packet with an nc packet
1050 * into a coded_packet and send it
1051 * @bat_priv: the bat priv with all the soft interface information
1052 * @skb: data skb to forward
1053 * @ethhdr: pointer to the ethernet header inside the skb
1054 * @nc_packet: structure containing the packet to the skb can be coded with
1055 * @neigh_node: next hop to forward packet to
1057 * Return: true if both packets are consumed, false otherwise.
1059 static bool batadv_nc_code_packets(struct batadv_priv
*bat_priv
,
1060 struct sk_buff
*skb
,
1061 struct ethhdr
*ethhdr
,
1062 struct batadv_nc_packet
*nc_packet
,
1063 struct batadv_neigh_node
*neigh_node
)
1065 u8 tq_weighted_neigh
, tq_weighted_coding
, tq_tmp
;
1066 struct sk_buff
*skb_dest
, *skb_src
;
1067 struct batadv_unicast_packet
*packet1
;
1068 struct batadv_unicast_packet
*packet2
;
1069 struct batadv_coded_packet
*coded_packet
;
1070 struct batadv_neigh_node
*neigh_tmp
, *router_neigh
;
1071 struct batadv_neigh_node
*router_coding
= NULL
;
1072 struct batadv_neigh_ifinfo
*router_neigh_ifinfo
= NULL
;
1073 struct batadv_neigh_ifinfo
*router_coding_ifinfo
= NULL
;
1074 u8
*first_source
, *first_dest
, *second_source
, *second_dest
;
1075 __be32 packet_id1
, packet_id2
;
1079 int unicast_size
= sizeof(*packet1
);
1080 int coded_size
= sizeof(*coded_packet
);
1081 int header_add
= coded_size
- unicast_size
;
1083 /* TODO: do we need to consider the outgoing interface for
1086 router_neigh
= batadv_orig_router_get(neigh_node
->orig_node
,
1091 router_neigh_ifinfo
= batadv_neigh_ifinfo_get(router_neigh
,
1093 if (!router_neigh_ifinfo
)
1096 neigh_tmp
= nc_packet
->neigh_node
;
1097 router_coding
= batadv_orig_router_get(neigh_tmp
->orig_node
,
1102 router_coding_ifinfo
= batadv_neigh_ifinfo_get(router_coding
,
1104 if (!router_coding_ifinfo
)
1107 tq_tmp
= router_neigh_ifinfo
->bat_iv
.tq_avg
;
1108 tq_weighted_neigh
= batadv_nc_random_weight_tq(tq_tmp
);
1109 tq_tmp
= router_coding_ifinfo
->bat_iv
.tq_avg
;
1110 tq_weighted_coding
= batadv_nc_random_weight_tq(tq_tmp
);
1112 /* Select one destination for the MAC-header dst-field based on
1113 * weighted TQ-values.
1115 if (tq_weighted_neigh
>= tq_weighted_coding
) {
1116 /* Destination from nc_packet is selected for MAC-header */
1117 first_dest
= nc_packet
->nc_path
->next_hop
;
1118 first_source
= nc_packet
->nc_path
->prev_hop
;
1119 second_dest
= neigh_node
->addr
;
1120 second_source
= ethhdr
->h_source
;
1121 packet1
= (struct batadv_unicast_packet
*)nc_packet
->skb
->data
;
1122 packet2
= (struct batadv_unicast_packet
*)skb
->data
;
1123 packet_id1
= nc_packet
->packet_id
;
1124 packet_id2
= batadv_skb_crc32(skb
,
1125 skb
->data
+ sizeof(*packet2
));
1127 /* Destination for skb is selected for MAC-header */
1128 first_dest
= neigh_node
->addr
;
1129 first_source
= ethhdr
->h_source
;
1130 second_dest
= nc_packet
->nc_path
->next_hop
;
1131 second_source
= nc_packet
->nc_path
->prev_hop
;
1132 packet1
= (struct batadv_unicast_packet
*)skb
->data
;
1133 packet2
= (struct batadv_unicast_packet
*)nc_packet
->skb
->data
;
1134 packet_id1
= batadv_skb_crc32(skb
,
1135 skb
->data
+ sizeof(*packet1
));
1136 packet_id2
= nc_packet
->packet_id
;
1139 /* Instead of zero padding the smallest data buffer, we
1140 * code into the largest.
1142 if (skb
->len
<= nc_packet
->skb
->len
) {
1143 skb_dest
= nc_packet
->skb
;
1147 skb_src
= nc_packet
->skb
;
1150 /* coding_len is used when decoding the packet shorter packet */
1151 coding_len
= skb_src
->len
- unicast_size
;
1153 if (skb_linearize(skb_dest
) < 0 || skb_linearize(skb_src
) < 0)
1156 skb_push(skb_dest
, header_add
);
1158 coded_packet
= (struct batadv_coded_packet
*)skb_dest
->data
;
1159 skb_reset_mac_header(skb_dest
);
1161 coded_packet
->packet_type
= BATADV_CODED
;
1162 coded_packet
->version
= BATADV_COMPAT_VERSION
;
1163 coded_packet
->ttl
= packet1
->ttl
;
1165 /* Info about first unicast packet */
1166 ether_addr_copy(coded_packet
->first_source
, first_source
);
1167 ether_addr_copy(coded_packet
->first_orig_dest
, packet1
->dest
);
1168 coded_packet
->first_crc
= packet_id1
;
1169 coded_packet
->first_ttvn
= packet1
->ttvn
;
1171 /* Info about second unicast packet */
1172 ether_addr_copy(coded_packet
->second_dest
, second_dest
);
1173 ether_addr_copy(coded_packet
->second_source
, second_source
);
1174 ether_addr_copy(coded_packet
->second_orig_dest
, packet2
->dest
);
1175 coded_packet
->second_crc
= packet_id2
;
1176 coded_packet
->second_ttl
= packet2
->ttl
;
1177 coded_packet
->second_ttvn
= packet2
->ttvn
;
1178 coded_packet
->coded_len
= htons(coding_len
);
1180 /* This is where the magic happens: Code skb_src into skb_dest */
1181 batadv_nc_memxor(skb_dest
->data
+ coded_size
,
1182 skb_src
->data
+ unicast_size
, coding_len
);
1184 /* Update counters accordingly */
1185 if (BATADV_SKB_CB(skb_src
)->decoded
&&
1186 BATADV_SKB_CB(skb_dest
)->decoded
) {
1187 /* Both packets are recoded */
1188 count
= skb_src
->len
+ ETH_HLEN
;
1189 count
+= skb_dest
->len
+ ETH_HLEN
;
1190 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE
, 2);
1191 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
, count
);
1192 } else if (!BATADV_SKB_CB(skb_src
)->decoded
&&
1193 !BATADV_SKB_CB(skb_dest
)->decoded
) {
1194 /* Both packets are newly coded */
1195 count
= skb_src
->len
+ ETH_HLEN
;
1196 count
+= skb_dest
->len
+ ETH_HLEN
;
1197 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE
, 2);
1198 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
, count
);
1199 } else if (BATADV_SKB_CB(skb_src
)->decoded
&&
1200 !BATADV_SKB_CB(skb_dest
)->decoded
) {
1201 /* skb_src recoded and skb_dest is newly coded */
1202 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_RECODE
);
1203 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
,
1204 skb_src
->len
+ ETH_HLEN
);
1205 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_CODE
);
1206 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
,
1207 skb_dest
->len
+ ETH_HLEN
);
1208 } else if (!BATADV_SKB_CB(skb_src
)->decoded
&&
1209 BATADV_SKB_CB(skb_dest
)->decoded
) {
1210 /* skb_src is newly coded and skb_dest is recoded */
1211 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_CODE
);
1212 batadv_add_counter(bat_priv
, BATADV_CNT_NC_CODE_BYTES
,
1213 skb_src
->len
+ ETH_HLEN
);
1214 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_RECODE
);
1215 batadv_add_counter(bat_priv
, BATADV_CNT_NC_RECODE_BYTES
,
1216 skb_dest
->len
+ ETH_HLEN
);
1219 /* skb_src is now coded into skb_dest, so free it */
1222 /* avoid duplicate free of skb from nc_packet */
1223 nc_packet
->skb
= NULL
;
1224 batadv_nc_packet_free(nc_packet
);
1226 /* Send the coded packet and return true */
1227 batadv_send_skb_packet(skb_dest
, neigh_node
->if_incoming
, first_dest
);
1231 batadv_neigh_node_put(router_neigh
);
1233 batadv_neigh_node_put(router_coding
);
1234 if (router_neigh_ifinfo
)
1235 batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo
);
1236 if (router_coding_ifinfo
)
1237 batadv_neigh_ifinfo_free_ref(router_coding_ifinfo
);
1242 * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
1243 * @skb: data skb to forward
1244 * @dst: destination mac address of the other skb to code with
1245 * @src: source mac address of skb
1247 * Whenever we network code a packet we have to check whether we received it in
1248 * a network coded form. If so, we may not be able to use it for coding because
1249 * some neighbors may also have received (overheard) the packet in the network
1250 * coded form without being able to decode it. It is hard to know which of the
1251 * neighboring nodes was able to decode the packet, therefore we can only
1252 * re-code the packet if the source of the previous encoded packet is involved.
1253 * Since the source encoded the packet we can be certain it has all necessary
1254 * decode information.
1256 * Return: true if coding of a decoded packet is allowed.
1258 static bool batadv_nc_skb_coding_possible(struct sk_buff
*skb
, u8
*dst
, u8
*src
)
1260 if (BATADV_SKB_CB(skb
)->decoded
&& !batadv_compare_eth(dst
, src
))
1266 * batadv_nc_path_search - Find the coding path matching in_nc_node and
1267 * out_nc_node to retrieve a buffered packet that can be used for coding.
1268 * @bat_priv: the bat priv with all the soft interface information
1269 * @in_nc_node: pointer to skb next hop's neighbor nc node
1270 * @out_nc_node: pointer to skb source's neighbor nc node
1271 * @skb: data skb to forward
1272 * @eth_dst: next hop mac address of skb
1274 * Return: true if coding of a decoded skb is allowed.
1276 static struct batadv_nc_packet
*
1277 batadv_nc_path_search(struct batadv_priv
*bat_priv
,
1278 struct batadv_nc_node
*in_nc_node
,
1279 struct batadv_nc_node
*out_nc_node
,
1280 struct sk_buff
*skb
,
1283 struct batadv_nc_path
*nc_path
, nc_path_key
;
1284 struct batadv_nc_packet
*nc_packet_out
= NULL
;
1285 struct batadv_nc_packet
*nc_packet
, *nc_packet_tmp
;
1286 struct batadv_hashtable
*hash
= bat_priv
->nc
.coding_hash
;
1292 /* Create almost path key */
1293 batadv_nc_hash_key_gen(&nc_path_key
, in_nc_node
->addr
,
1295 idx
= batadv_nc_hash_choose(&nc_path_key
, hash
->size
);
1297 /* Check for coding opportunities in this nc_path */
1299 hlist_for_each_entry_rcu(nc_path
, &hash
->table
[idx
], hash_entry
) {
1300 if (!batadv_compare_eth(nc_path
->prev_hop
, in_nc_node
->addr
))
1303 if (!batadv_compare_eth(nc_path
->next_hop
, out_nc_node
->addr
))
1306 spin_lock_bh(&nc_path
->packet_list_lock
);
1307 if (list_empty(&nc_path
->packet_list
)) {
1308 spin_unlock_bh(&nc_path
->packet_list_lock
);
1312 list_for_each_entry_safe(nc_packet
, nc_packet_tmp
,
1313 &nc_path
->packet_list
, list
) {
1314 if (!batadv_nc_skb_coding_possible(nc_packet
->skb
,
1319 /* Coding opportunity is found! */
1320 list_del(&nc_packet
->list
);
1321 nc_packet_out
= nc_packet
;
1325 spin_unlock_bh(&nc_path
->packet_list_lock
);
1330 return nc_packet_out
;
1334 * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
1335 * skb's sender (may be equal to the originator).
1336 * @bat_priv: the bat priv with all the soft interface information
1337 * @skb: data skb to forward
1338 * @eth_dst: next hop mac address of skb
1339 * @eth_src: source mac address of skb
1340 * @in_nc_node: pointer to skb next hop's neighbor nc node
1342 * Return: an nc packet if a suitable coding packet was found, NULL otherwise.
1344 static struct batadv_nc_packet
*
1345 batadv_nc_skb_src_search(struct batadv_priv
*bat_priv
,
1346 struct sk_buff
*skb
,
1349 struct batadv_nc_node
*in_nc_node
)
1351 struct batadv_orig_node
*orig_node
;
1352 struct batadv_nc_node
*out_nc_node
;
1353 struct batadv_nc_packet
*nc_packet
= NULL
;
1355 orig_node
= batadv_orig_hash_find(bat_priv
, eth_src
);
1360 list_for_each_entry_rcu(out_nc_node
,
1361 &orig_node
->out_coding_list
, list
) {
1362 /* Check if the skb is decoded and if recoding is possible */
1363 if (!batadv_nc_skb_coding_possible(skb
,
1364 out_nc_node
->addr
, eth_src
))
1367 /* Search for an opportunity in this nc_path */
1368 nc_packet
= batadv_nc_path_search(bat_priv
, in_nc_node
,
1369 out_nc_node
, skb
, eth_dst
);
1375 batadv_orig_node_put(orig_node
);
1380 * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
1381 * unicast skb before it is stored for use in later decoding
1382 * @bat_priv: the bat priv with all the soft interface information
1383 * @skb: data skb to store
1384 * @eth_dst_new: new destination mac address of skb
1386 static void batadv_nc_skb_store_before_coding(struct batadv_priv
*bat_priv
,
1387 struct sk_buff
*skb
,
1390 struct ethhdr
*ethhdr
;
1392 /* Copy skb header to change the mac header */
1393 skb
= pskb_copy_for_clone(skb
, GFP_ATOMIC
);
1397 /* Set the mac header as if we actually sent the packet uncoded */
1398 ethhdr
= eth_hdr(skb
);
1399 ether_addr_copy(ethhdr
->h_source
, ethhdr
->h_dest
);
1400 ether_addr_copy(ethhdr
->h_dest
, eth_dst_new
);
1402 /* Set data pointer to MAC header to mimic packets from our tx path */
1403 skb_push(skb
, ETH_HLEN
);
1405 /* Add the packet to the decoding packet pool */
1406 batadv_nc_skb_store_for_decoding(bat_priv
, skb
);
1408 /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
1415 * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
1416 * @skb: data skb to forward
1417 * @neigh_node: next hop to forward packet to
1418 * @ethhdr: pointer to the ethernet header inside the skb
1420 * Loops through list of neighboring nodes the next hop has a good connection to
1421 * (receives OGMs with a sufficient quality). We need to find a neighbor of our
1422 * next hop that potentially sent a packet which our next hop also received
1423 * (overheard) and has stored for later decoding.
1425 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1427 static bool batadv_nc_skb_dst_search(struct sk_buff
*skb
,
1428 struct batadv_neigh_node
*neigh_node
,
1429 struct ethhdr
*ethhdr
)
1431 struct net_device
*netdev
= neigh_node
->if_incoming
->soft_iface
;
1432 struct batadv_priv
*bat_priv
= netdev_priv(netdev
);
1433 struct batadv_orig_node
*orig_node
= neigh_node
->orig_node
;
1434 struct batadv_nc_node
*nc_node
;
1435 struct batadv_nc_packet
*nc_packet
= NULL
;
1438 list_for_each_entry_rcu(nc_node
, &orig_node
->in_coding_list
, list
) {
1439 /* Search for coding opportunity with this in_nc_node */
1440 nc_packet
= batadv_nc_skb_src_search(bat_priv
, skb
,
1442 ethhdr
->h_source
, nc_node
);
1444 /* Opportunity was found, so stop searching */
1453 /* Save packets for later decoding */
1454 batadv_nc_skb_store_before_coding(bat_priv
, skb
,
1456 batadv_nc_skb_store_before_coding(bat_priv
, nc_packet
->skb
,
1457 nc_packet
->neigh_node
->addr
);
1459 /* Code and send packets */
1460 if (batadv_nc_code_packets(bat_priv
, skb
, ethhdr
, nc_packet
,
1464 /* out of mem ? Coding failed - we have to free the buffered packet
1465 * to avoid memleaks. The skb passed as argument will be dealt with
1466 * by the calling function.
1468 batadv_nc_send_packet(nc_packet
);
1473 * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
1474 * @skb: skb to add to path
1475 * @nc_path: path to add skb to
1476 * @neigh_node: next hop to forward packet to
1477 * @packet_id: checksum to identify packet
1479 * Return: true if the packet was buffered or false in case of an error.
1481 static bool batadv_nc_skb_add_to_path(struct sk_buff
*skb
,
1482 struct batadv_nc_path
*nc_path
,
1483 struct batadv_neigh_node
*neigh_node
,
1486 struct batadv_nc_packet
*nc_packet
;
1488 nc_packet
= kzalloc(sizeof(*nc_packet
), GFP_ATOMIC
);
1492 /* Initialize nc_packet */
1493 nc_packet
->timestamp
= jiffies
;
1494 nc_packet
->packet_id
= packet_id
;
1495 nc_packet
->skb
= skb
;
1496 nc_packet
->neigh_node
= neigh_node
;
1497 nc_packet
->nc_path
= nc_path
;
1499 /* Add coding packet to list */
1500 spin_lock_bh(&nc_path
->packet_list_lock
);
1501 list_add_tail(&nc_packet
->list
, &nc_path
->packet_list
);
1502 spin_unlock_bh(&nc_path
->packet_list_lock
);
1508 * batadv_nc_skb_forward - try to code a packet or add it to the coding packet
1510 * @skb: data skb to forward
1511 * @neigh_node: next hop to forward packet to
1513 * Return: true if the skb was consumed (encoded packet sent) or false otherwise
1515 bool batadv_nc_skb_forward(struct sk_buff
*skb
,
1516 struct batadv_neigh_node
*neigh_node
)
1518 const struct net_device
*netdev
= neigh_node
->if_incoming
->soft_iface
;
1519 struct batadv_priv
*bat_priv
= netdev_priv(netdev
);
1520 struct batadv_unicast_packet
*packet
;
1521 struct batadv_nc_path
*nc_path
;
1522 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1526 /* Check if network coding is enabled */
1527 if (!atomic_read(&bat_priv
->network_coding
))
1530 /* We only handle unicast packets */
1531 payload
= skb_network_header(skb
);
1532 packet
= (struct batadv_unicast_packet
*)payload
;
1533 if (packet
->packet_type
!= BATADV_UNICAST
)
1536 /* Try to find a coding opportunity and send the skb if one is found */
1537 if (batadv_nc_skb_dst_search(skb
, neigh_node
, ethhdr
))
1540 /* Find or create a nc_path for this src-dst pair */
1541 nc_path
= batadv_nc_get_path(bat_priv
,
1542 bat_priv
->nc
.coding_hash
,
1549 /* Add skb to nc_path */
1550 packet_id
= batadv_skb_crc32(skb
, payload
+ sizeof(*packet
));
1551 if (!batadv_nc_skb_add_to_path(skb
, nc_path
, neigh_node
, packet_id
))
1554 /* Packet is consumed */
1558 batadv_nc_path_free_ref(nc_path
);
1560 /* Packet is not consumed */
1565 * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
1566 * when decoding coded packets
1567 * @bat_priv: the bat priv with all the soft interface information
1568 * @skb: data skb to store
1570 void batadv_nc_skb_store_for_decoding(struct batadv_priv
*bat_priv
,
1571 struct sk_buff
*skb
)
1573 struct batadv_unicast_packet
*packet
;
1574 struct batadv_nc_path
*nc_path
;
1575 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1579 /* Check if network coding is enabled */
1580 if (!atomic_read(&bat_priv
->network_coding
))
1583 /* Check for supported packet type */
1584 payload
= skb_network_header(skb
);
1585 packet
= (struct batadv_unicast_packet
*)payload
;
1586 if (packet
->packet_type
!= BATADV_UNICAST
)
1589 /* Find existing nc_path or create a new */
1590 nc_path
= batadv_nc_get_path(bat_priv
,
1591 bat_priv
->nc
.decoding_hash
,
1598 /* Clone skb and adjust skb->data to point at batman header */
1599 skb
= skb_clone(skb
, GFP_ATOMIC
);
1603 if (unlikely(!pskb_may_pull(skb
, ETH_HLEN
)))
1606 if (unlikely(!skb_pull_rcsum(skb
, ETH_HLEN
)))
1609 /* Add skb to nc_path */
1610 packet_id
= batadv_skb_crc32(skb
, payload
+ sizeof(*packet
));
1611 if (!batadv_nc_skb_add_to_path(skb
, nc_path
, NULL
, packet_id
))
1614 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_BUFFER
);
1620 batadv_nc_path_free_ref(nc_path
);
1626 * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
1627 * should be saved in the decoding buffer and, if so, store it there
1628 * @bat_priv: the bat priv with all the soft interface information
1629 * @skb: unicast skb to store
1631 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv
*bat_priv
,
1632 struct sk_buff
*skb
)
1634 struct ethhdr
*ethhdr
= eth_hdr(skb
);
1636 if (batadv_is_my_mac(bat_priv
, ethhdr
->h_dest
))
1639 /* Set data pointer to MAC header to mimic packets from our tx path */
1640 skb_push(skb
, ETH_HLEN
);
1642 batadv_nc_skb_store_for_decoding(bat_priv
, skb
);
1646 * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
1648 * @bat_priv: the bat priv with all the soft interface information
1649 * @skb: unicast skb to decode
1650 * @nc_packet: decode data needed to decode the skb
1652 * Return: pointer to decoded unicast packet if the packet was decoded or NULL
1653 * in case of an error.
1655 static struct batadv_unicast_packet
*
1656 batadv_nc_skb_decode_packet(struct batadv_priv
*bat_priv
, struct sk_buff
*skb
,
1657 struct batadv_nc_packet
*nc_packet
)
1659 const int h_size
= sizeof(struct batadv_unicast_packet
);
1660 const int h_diff
= sizeof(struct batadv_coded_packet
) - h_size
;
1661 struct batadv_unicast_packet
*unicast_packet
;
1662 struct batadv_coded_packet coded_packet_tmp
;
1663 struct ethhdr
*ethhdr
, ethhdr_tmp
;
1664 u8
*orig_dest
, ttl
, ttvn
;
1665 unsigned int coding_len
;
1668 /* Save headers temporarily */
1669 memcpy(&coded_packet_tmp
, skb
->data
, sizeof(coded_packet_tmp
));
1670 memcpy(ðhdr_tmp
, skb_mac_header(skb
), sizeof(ethhdr_tmp
));
1672 if (skb_cow(skb
, 0) < 0)
1675 if (unlikely(!skb_pull_rcsum(skb
, h_diff
)))
1678 /* Data points to batman header, so set mac header 14 bytes before
1679 * and network to data
1681 skb_set_mac_header(skb
, -ETH_HLEN
);
1682 skb_reset_network_header(skb
);
1684 /* Reconstruct original mac header */
1685 ethhdr
= eth_hdr(skb
);
1686 *ethhdr
= ethhdr_tmp
;
1688 /* Select the correct unicast header information based on the location
1689 * of our mac address in the coded_packet header
1691 if (batadv_is_my_mac(bat_priv
, coded_packet_tmp
.second_dest
)) {
1692 /* If we are the second destination the packet was overheard,
1693 * so the Ethernet address must be copied to h_dest and
1694 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
1696 ether_addr_copy(ethhdr
->h_dest
, coded_packet_tmp
.second_dest
);
1697 skb
->pkt_type
= PACKET_HOST
;
1699 orig_dest
= coded_packet_tmp
.second_orig_dest
;
1700 ttl
= coded_packet_tmp
.second_ttl
;
1701 ttvn
= coded_packet_tmp
.second_ttvn
;
1703 orig_dest
= coded_packet_tmp
.first_orig_dest
;
1704 ttl
= coded_packet_tmp
.ttl
;
1705 ttvn
= coded_packet_tmp
.first_ttvn
;
1708 coding_len
= ntohs(coded_packet_tmp
.coded_len
);
1710 if (coding_len
> skb
->len
)
1713 /* Here the magic is reversed:
1714 * extract the missing packet from the received coded packet
1716 batadv_nc_memxor(skb
->data
+ h_size
,
1717 nc_packet
->skb
->data
+ h_size
,
1720 /* Resize decoded skb if decoded with larger packet */
1721 if (nc_packet
->skb
->len
> coding_len
+ h_size
) {
1722 err
= pskb_trim_rcsum(skb
, coding_len
+ h_size
);
1727 /* Create decoded unicast packet */
1728 unicast_packet
= (struct batadv_unicast_packet
*)skb
->data
;
1729 unicast_packet
->packet_type
= BATADV_UNICAST
;
1730 unicast_packet
->version
= BATADV_COMPAT_VERSION
;
1731 unicast_packet
->ttl
= ttl
;
1732 ether_addr_copy(unicast_packet
->dest
, orig_dest
);
1733 unicast_packet
->ttvn
= ttvn
;
1735 batadv_nc_packet_free(nc_packet
);
1736 return unicast_packet
;
1740 * batadv_nc_find_decoding_packet - search through buffered decoding data to
1741 * find the data needed to decode the coded packet
1742 * @bat_priv: the bat priv with all the soft interface information
1743 * @ethhdr: pointer to the ethernet header inside the coded packet
1744 * @coded: coded packet we try to find decode data for
1746 * Return: pointer to nc packet if the needed data was found or NULL otherwise.
1748 static struct batadv_nc_packet
*
1749 batadv_nc_find_decoding_packet(struct batadv_priv
*bat_priv
,
1750 struct ethhdr
*ethhdr
,
1751 struct batadv_coded_packet
*coded
)
1753 struct batadv_hashtable
*hash
= bat_priv
->nc
.decoding_hash
;
1754 struct batadv_nc_packet
*tmp_nc_packet
, *nc_packet
= NULL
;
1755 struct batadv_nc_path
*nc_path
, nc_path_key
;
1763 /* Select the correct packet id based on the location of our mac-addr */
1764 dest
= ethhdr
->h_source
;
1765 if (!batadv_is_my_mac(bat_priv
, coded
->second_dest
)) {
1766 source
= coded
->second_source
;
1767 packet_id
= coded
->second_crc
;
1769 source
= coded
->first_source
;
1770 packet_id
= coded
->first_crc
;
1773 batadv_nc_hash_key_gen(&nc_path_key
, source
, dest
);
1774 index
= batadv_nc_hash_choose(&nc_path_key
, hash
->size
);
1776 /* Search for matching coding path */
1778 hlist_for_each_entry_rcu(nc_path
, &hash
->table
[index
], hash_entry
) {
1779 /* Find matching nc_packet */
1780 spin_lock_bh(&nc_path
->packet_list_lock
);
1781 list_for_each_entry(tmp_nc_packet
,
1782 &nc_path
->packet_list
, list
) {
1783 if (packet_id
== tmp_nc_packet
->packet_id
) {
1784 list_del(&tmp_nc_packet
->list
);
1786 nc_packet
= tmp_nc_packet
;
1790 spin_unlock_bh(&nc_path
->packet_list_lock
);
1798 batadv_dbg(BATADV_DBG_NC
, bat_priv
,
1799 "No decoding packet found for %u\n", packet_id
);
1805 * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
1806 * resulting unicast packet
1807 * @skb: incoming coded packet
1808 * @recv_if: pointer to interface this packet was received on
1810 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1813 static int batadv_nc_recv_coded_packet(struct sk_buff
*skb
,
1814 struct batadv_hard_iface
*recv_if
)
1816 struct batadv_priv
*bat_priv
= netdev_priv(recv_if
->soft_iface
);
1817 struct batadv_unicast_packet
*unicast_packet
;
1818 struct batadv_coded_packet
*coded_packet
;
1819 struct batadv_nc_packet
*nc_packet
;
1820 struct ethhdr
*ethhdr
;
1821 int hdr_size
= sizeof(*coded_packet
);
1823 /* Check if network coding is enabled */
1824 if (!atomic_read(&bat_priv
->network_coding
))
1827 /* Make sure we can access (and remove) header */
1828 if (unlikely(!pskb_may_pull(skb
, hdr_size
)))
1831 coded_packet
= (struct batadv_coded_packet
*)skb
->data
;
1832 ethhdr
= eth_hdr(skb
);
1834 /* Verify frame is destined for us */
1835 if (!batadv_is_my_mac(bat_priv
, ethhdr
->h_dest
) &&
1836 !batadv_is_my_mac(bat_priv
, coded_packet
->second_dest
))
1839 /* Update stat counter */
1840 if (batadv_is_my_mac(bat_priv
, coded_packet
->second_dest
))
1841 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_SNIFFED
);
1843 nc_packet
= batadv_nc_find_decoding_packet(bat_priv
, ethhdr
,
1846 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE_FAILED
);
1850 /* Make skb's linear, because decoding accesses the entire buffer */
1851 if (skb_linearize(skb
) < 0)
1852 goto free_nc_packet
;
1854 if (skb_linearize(nc_packet
->skb
) < 0)
1855 goto free_nc_packet
;
1857 /* Decode the packet */
1858 unicast_packet
= batadv_nc_skb_decode_packet(bat_priv
, skb
, nc_packet
);
1859 if (!unicast_packet
) {
1860 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE_FAILED
);
1861 goto free_nc_packet
;
1864 /* Mark packet as decoded to do correct recoding when forwarding */
1865 BATADV_SKB_CB(skb
)->decoded
= true;
1866 batadv_inc_counter(bat_priv
, BATADV_CNT_NC_DECODE
);
1867 batadv_add_counter(bat_priv
, BATADV_CNT_NC_DECODE_BYTES
,
1868 skb
->len
+ ETH_HLEN
);
1869 return batadv_recv_unicast_packet(skb
, recv_if
);
1872 batadv_nc_packet_free(nc_packet
);
1877 * batadv_nc_mesh_free - clean up network coding memory
1878 * @bat_priv: the bat priv with all the soft interface information
1880 void batadv_nc_mesh_free(struct batadv_priv
*bat_priv
)
1882 batadv_tvlv_container_unregister(bat_priv
, BATADV_TVLV_NC
, 1);
1883 batadv_tvlv_handler_unregister(bat_priv
, BATADV_TVLV_NC
, 1);
1884 cancel_delayed_work_sync(&bat_priv
->nc
.work
);
1886 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.coding_hash
, NULL
);
1887 batadv_hash_destroy(bat_priv
->nc
.coding_hash
);
1888 batadv_nc_purge_paths(bat_priv
, bat_priv
->nc
.decoding_hash
, NULL
);
1889 batadv_hash_destroy(bat_priv
->nc
.decoding_hash
);
1893 * batadv_nc_nodes_seq_print_text - print the nc node information
1894 * @seq: seq file to print on
1899 int batadv_nc_nodes_seq_print_text(struct seq_file
*seq
, void *offset
)
1901 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
1902 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
1903 struct batadv_hashtable
*hash
= bat_priv
->orig_hash
;
1904 struct batadv_hard_iface
*primary_if
;
1905 struct hlist_head
*head
;
1906 struct batadv_orig_node
*orig_node
;
1907 struct batadv_nc_node
*nc_node
;
1910 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
1914 /* Traverse list of originators */
1915 for (i
= 0; i
< hash
->size
; i
++) {
1916 head
= &hash
->table
[i
];
1918 /* For each orig_node in this bin */
1920 hlist_for_each_entry_rcu(orig_node
, head
, hash_entry
) {
1921 /* no need to print the orig node if it does not have
1922 * network coding neighbors
1924 if (list_empty(&orig_node
->in_coding_list
) &&
1925 list_empty(&orig_node
->out_coding_list
))
1928 seq_printf(seq
, "Node: %pM\n", orig_node
->orig
);
1930 seq_puts(seq
, " Ingoing: ");
1931 /* For each in_nc_node to this orig_node */
1932 list_for_each_entry_rcu(nc_node
,
1933 &orig_node
->in_coding_list
,
1935 seq_printf(seq
, "%pM ",
1937 seq_puts(seq
, "\n");
1939 seq_puts(seq
, " Outgoing: ");
1940 /* For out_nc_node to this orig_node */
1941 list_for_each_entry_rcu(nc_node
,
1942 &orig_node
->out_coding_list
,
1944 seq_printf(seq
, "%pM ",
1946 seq_puts(seq
, "\n\n");
1953 batadv_hardif_put(primary_if
);
1958 * batadv_nc_init_debugfs - create nc folder and related files in debugfs
1959 * @bat_priv: the bat priv with all the soft interface information
1961 * Return: 0 on success or negative error number in case of failure
1963 int batadv_nc_init_debugfs(struct batadv_priv
*bat_priv
)
1965 struct dentry
*nc_dir
, *file
;
1967 nc_dir
= debugfs_create_dir("nc", bat_priv
->debug_dir
);
1971 file
= debugfs_create_u8("min_tq", S_IRUGO
| S_IWUSR
, nc_dir
,
1972 &bat_priv
->nc
.min_tq
);
1976 file
= debugfs_create_u32("max_fwd_delay", S_IRUGO
| S_IWUSR
, nc_dir
,
1977 &bat_priv
->nc
.max_fwd_delay
);
1981 file
= debugfs_create_u32("max_buffer_time", S_IRUGO
| S_IWUSR
, nc_dir
,
1982 &bat_priv
->nc
.max_buffer_time
);