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1 | /* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors: |
2 | * |
3 | * Martin Hundebøll, Jeppe Ledet-Pedersen |
4 | * |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of version 2 of the GNU General Public |
7 | * License as published by the Free Software Foundation. |
8 | * |
9 | * This program is distributed in the hope that it will be useful, but |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * General Public License for more details. |
13 | * |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write to the Free Software |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
17 | * 02110-1301, USA |
18 | */ |
19 | |
20 | #include <linux/debugfs.h> |
21 | |
22 | #include "main.h" |
23 | #include "hash.h" |
24 | #include "network-coding.h" |
25 | #include "send.h" |
26 | #include "originator.h" |
27 | #include "hard-interface.h" |
28 | #include "routing.h" |
29 | |
30 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
31 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
32 | |
33 | static void batadv_nc_worker(struct work_struct *work); |
34 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
35 | struct batadv_hard_iface *recv_if); |
36 | |
37 | /** |
38 | * batadv_nc_init - one-time initialization for network coding |
39 | */ |
40 | int __init batadv_nc_init(void) |
41 | { |
42 | int ret; |
43 | |
44 | /* Register our packet type */ |
45 | ret = batadv_recv_handler_register(BATADV_CODED, |
46 | batadv_nc_recv_coded_packet); |
47 | |
48 | return ret; |
49 | } |
50 | |
51 | /** |
52 | * batadv_nc_start_timer - initialise the nc periodic worker |
53 | * @bat_priv: the bat priv with all the soft interface information |
54 | */ |
55 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) |
56 | { |
57 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, |
58 | msecs_to_jiffies(10)); |
59 | } |
60 | |
61 | /** |
62 | * batadv_nc_tvlv_container_update - update the network coding tvlv container |
63 | * after network coding setting change |
64 | * @bat_priv: the bat priv with all the soft interface information |
65 | */ |
66 | static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv) |
67 | { |
68 | char nc_mode; |
69 | |
70 | nc_mode = atomic_read(&bat_priv->network_coding); |
71 | |
72 | switch (nc_mode) { |
73 | case 0: |
74 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
75 | break; |
76 | case 1: |
77 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1, |
78 | NULL, 0); |
79 | break; |
80 | } |
81 | } |
82 | |
83 | /** |
84 | * batadv_nc_status_update - update the network coding tvlv container after |
85 | * network coding setting change |
86 | * @net_dev: the soft interface net device |
87 | */ |
88 | void batadv_nc_status_update(struct net_device *net_dev) |
89 | { |
90 | struct batadv_priv *bat_priv = netdev_priv(net_dev); |
91 | batadv_nc_tvlv_container_update(bat_priv); |
92 | } |
93 | |
94 | /** |
95 | * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container |
96 | * @bat_priv: the bat priv with all the soft interface information |
97 | * @orig: the orig_node of the ogm |
98 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) |
99 | * @tvlv_value: tvlv buffer containing the gateway data |
100 | * @tvlv_value_len: tvlv buffer length |
101 | */ |
102 | static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, |
103 | struct batadv_orig_node *orig, |
104 | uint8_t flags, |
105 | void *tvlv_value, |
106 | uint16_t tvlv_value_len) |
107 | { |
108 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) |
109 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC; |
110 | else |
111 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC; |
112 | } |
113 | |
114 | /** |
115 | * batadv_nc_mesh_init - initialise coding hash table and start house keeping |
116 | * @bat_priv: the bat priv with all the soft interface information |
117 | */ |
118 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
119 | { |
120 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
121 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
122 | |
123 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
124 | return 0; |
125 | |
126 | bat_priv->nc.coding_hash = batadv_hash_new(128); |
127 | if (!bat_priv->nc.coding_hash) |
128 | goto err; |
129 | |
130 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, |
131 | &batadv_nc_coding_hash_lock_class_key); |
132 | |
133 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
134 | if (!bat_priv->nc.decoding_hash) |
135 | goto err; |
136 | |
137 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, |
138 | &batadv_nc_decoding_hash_lock_class_key); |
139 | |
140 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
141 | batadv_nc_start_timer(bat_priv); |
142 | |
143 | batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1, |
144 | NULL, BATADV_TVLV_NC, 1, |
145 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); |
146 | batadv_nc_tvlv_container_update(bat_priv); |
147 | return 0; |
148 | |
149 | err: |
150 | return -ENOMEM; |
151 | } |
152 | |
153 | /** |
154 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables |
155 | * @bat_priv: the bat priv with all the soft interface information |
156 | */ |
157 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) |
158 | { |
159 | atomic_set(&bat_priv->network_coding, 1); |
160 | bat_priv->nc.min_tq = 200; |
161 | bat_priv->nc.max_fwd_delay = 10; |
162 | bat_priv->nc.max_buffer_time = 200; |
163 | } |
164 | |
165 | /** |
166 | * batadv_nc_init_orig - initialise the nc fields of an orig_node |
167 | * @orig_node: the orig_node which is going to be initialised |
168 | */ |
169 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) |
170 | { |
171 | INIT_LIST_HEAD(&orig_node->in_coding_list); |
172 | INIT_LIST_HEAD(&orig_node->out_coding_list); |
173 | spin_lock_init(&orig_node->in_coding_list_lock); |
174 | spin_lock_init(&orig_node->out_coding_list_lock); |
175 | } |
176 | |
177 | /** |
178 | * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove |
179 | * its refcount on the orig_node |
180 | * @rcu: rcu pointer of the nc node |
181 | */ |
182 | static void batadv_nc_node_free_rcu(struct rcu_head *rcu) |
183 | { |
184 | struct batadv_nc_node *nc_node; |
185 | |
186 | nc_node = container_of(rcu, struct batadv_nc_node, rcu); |
187 | batadv_orig_node_free_ref(nc_node->orig_node); |
188 | kfree(nc_node); |
189 | } |
190 | |
191 | /** |
192 | * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly |
193 | * frees it |
194 | * @nc_node: the nc node to free |
195 | */ |
196 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) |
197 | { |
198 | if (atomic_dec_and_test(&nc_node->refcount)) |
199 | call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu); |
200 | } |
201 | |
202 | /** |
203 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly |
204 | * frees it |
205 | * @nc_path: the nc node to free |
206 | */ |
207 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) |
208 | { |
209 | if (atomic_dec_and_test(&nc_path->refcount)) |
210 | kfree_rcu(nc_path, rcu); |
211 | } |
212 | |
213 | /** |
214 | * batadv_nc_packet_free - frees nc packet |
215 | * @nc_packet: the nc packet to free |
216 | */ |
217 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) |
218 | { |
219 | if (nc_packet->skb) |
220 | kfree_skb(nc_packet->skb); |
221 | |
222 | batadv_nc_path_free_ref(nc_packet->nc_path); |
223 | kfree(nc_packet); |
224 | } |
225 | |
226 | /** |
227 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged |
228 | * @bat_priv: the bat priv with all the soft interface information |
229 | * @nc_node: the nc node to check |
230 | * |
231 | * Returns true if the entry has to be purged now, false otherwise |
232 | */ |
233 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, |
234 | struct batadv_nc_node *nc_node) |
235 | { |
236 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) |
237 | return true; |
238 | |
239 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); |
240 | } |
241 | |
242 | /** |
243 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out |
244 | * @bat_priv: the bat priv with all the soft interface information |
245 | * @nc_path: the nc path to check |
246 | * |
247 | * Returns true if the entry has to be purged now, false otherwise |
248 | */ |
249 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, |
250 | struct batadv_nc_path *nc_path) |
251 | { |
252 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) |
253 | return true; |
254 | |
255 | /* purge the path when no packets has been added for 10 times the |
256 | * max_fwd_delay time |
257 | */ |
258 | return batadv_has_timed_out(nc_path->last_valid, |
259 | bat_priv->nc.max_fwd_delay * 10); |
260 | } |
261 | |
262 | /** |
263 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out |
264 | * @bat_priv: the bat priv with all the soft interface information |
265 | * @nc_path: the nc path to check |
266 | * |
267 | * Returns true if the entry has to be purged now, false otherwise |
268 | */ |
269 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, |
270 | struct batadv_nc_path *nc_path) |
271 | { |
272 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) |
273 | return true; |
274 | |
275 | /* purge the path when no packets has been added for 10 times the |
276 | * max_buffer time |
277 | */ |
278 | return batadv_has_timed_out(nc_path->last_valid, |
279 | bat_priv->nc.max_buffer_time*10); |
280 | } |
281 | |
282 | /** |
283 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale |
284 | * entries |
285 | * @bat_priv: the bat priv with all the soft interface information |
286 | * @list: list of nc nodes |
287 | * @lock: nc node list lock |
288 | * @to_purge: function in charge to decide whether an entry has to be purged or |
289 | * not. This function takes the nc node as argument and has to return |
290 | * a boolean value: true if the entry has to be deleted, false |
291 | * otherwise |
292 | */ |
293 | static void |
294 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, |
295 | struct list_head *list, |
296 | spinlock_t *lock, |
297 | bool (*to_purge)(struct batadv_priv *, |
298 | struct batadv_nc_node *)) |
299 | { |
300 | struct batadv_nc_node *nc_node, *nc_node_tmp; |
301 | |
302 | /* For each nc_node in list */ |
303 | spin_lock_bh(lock); |
304 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { |
305 | /* if an helper function has been passed as parameter, |
306 | * ask it if the entry has to be purged or not |
307 | */ |
308 | if (to_purge && !to_purge(bat_priv, nc_node)) |
309 | continue; |
310 | |
311 | batadv_dbg(BATADV_DBG_NC, bat_priv, |
312 | "Removing nc_node %pM -> %pM\n", |
313 | nc_node->addr, nc_node->orig_node->orig); |
314 | list_del_rcu(&nc_node->list); |
315 | batadv_nc_node_free_ref(nc_node); |
316 | } |
317 | spin_unlock_bh(lock); |
318 | } |
319 | |
320 | /** |
321 | * batadv_nc_purge_orig - purges all nc node data attached of the given |
322 | * originator |
323 | * @bat_priv: the bat priv with all the soft interface information |
324 | * @orig_node: orig_node with the nc node entries to be purged |
325 | * @to_purge: function in charge to decide whether an entry has to be purged or |
326 | * not. This function takes the nc node as argument and has to return |
327 | * a boolean value: true is the entry has to be deleted, false |
328 | * otherwise |
329 | */ |
330 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, |
331 | struct batadv_orig_node *orig_node, |
332 | bool (*to_purge)(struct batadv_priv *, |
333 | struct batadv_nc_node *)) |
334 | { |
335 | /* Check ingoing nc_node's of this orig_node */ |
336 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, |
337 | &orig_node->in_coding_list_lock, |
338 | to_purge); |
339 | |
340 | /* Check outgoing nc_node's of this orig_node */ |
341 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, |
342 | &orig_node->out_coding_list_lock, |
343 | to_purge); |
344 | } |
345 | |
346 | /** |
347 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they |
348 | * have timed out nc nodes |
349 | * @bat_priv: the bat priv with all the soft interface information |
350 | */ |
351 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) |
352 | { |
353 | struct batadv_hashtable *hash = bat_priv->orig_hash; |
354 | struct hlist_head *head; |
355 | struct batadv_orig_node *orig_node; |
356 | uint32_t i; |
357 | |
358 | if (!hash) |
359 | return; |
360 | |
361 | /* For each orig_node */ |
362 | for (i = 0; i < hash->size; i++) { |
363 | head = &hash->table[i]; |
364 | |
365 | rcu_read_lock(); |
366 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) |
367 | batadv_nc_purge_orig(bat_priv, orig_node, |
368 | batadv_nc_to_purge_nc_node); |
369 | rcu_read_unlock(); |
370 | } |
371 | } |
372 | |
373 | /** |
374 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove |
375 | * unused ones |
376 | * @bat_priv: the bat priv with all the soft interface information |
377 | * @hash: hash table containing the nc paths to check |
378 | * @to_purge: function in charge to decide whether an entry has to be purged or |
379 | * not. This function takes the nc node as argument and has to return |
380 | * a boolean value: true is the entry has to be deleted, false |
381 | * otherwise |
382 | */ |
383 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, |
384 | struct batadv_hashtable *hash, |
385 | bool (*to_purge)(struct batadv_priv *, |
386 | struct batadv_nc_path *)) |
387 | { |
388 | struct hlist_head *head; |
389 | struct hlist_node *node_tmp; |
390 | struct batadv_nc_path *nc_path; |
391 | spinlock_t *lock; /* Protects lists in hash */ |
392 | uint32_t i; |
393 | |
394 | for (i = 0; i < hash->size; i++) { |
395 | head = &hash->table[i]; |
396 | lock = &hash->list_locks[i]; |
397 | |
398 | /* For each nc_path in this bin */ |
399 | spin_lock_bh(lock); |
400 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { |
401 | /* if an helper function has been passed as parameter, |
402 | * ask it if the entry has to be purged or not |
403 | */ |
404 | if (to_purge && !to_purge(bat_priv, nc_path)) |
405 | continue; |
406 | |
407 | /* purging an non-empty nc_path should never happen, but |
408 | * is observed under high CPU load. Delay the purging |
409 | * until next iteration to allow the packet_list to be |
410 | * emptied first. |
411 | */ |
412 | if (!unlikely(list_empty(&nc_path->packet_list))) { |
413 | net_ratelimited_function(printk, |
414 | KERN_WARNING |
415 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", |
416 | nc_path->prev_hop, |
417 | nc_path->next_hop); |
418 | continue; |
419 | } |
420 | |
421 | /* nc_path is unused, so remove it */ |
422 | batadv_dbg(BATADV_DBG_NC, bat_priv, |
423 | "Remove nc_path %pM -> %pM\n", |
424 | nc_path->prev_hop, nc_path->next_hop); |
425 | hlist_del_rcu(&nc_path->hash_entry); |
426 | batadv_nc_path_free_ref(nc_path); |
427 | } |
428 | spin_unlock_bh(lock); |
429 | } |
430 | } |
431 | |
432 | /** |
433 | * batadv_nc_hash_key_gen - computes the nc_path hash key |
434 | * @key: buffer to hold the final hash key |
435 | * @src: source ethernet mac address going into the hash key |
436 | * @dst: destination ethernet mac address going into the hash key |
437 | */ |
438 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, |
439 | const char *dst) |
440 | { |
441 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); |
442 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); |
443 | } |
444 | |
445 | /** |
446 | * batadv_nc_hash_choose - compute the hash value for an nc path |
447 | * @data: data to hash |
448 | * @size: size of the hash table |
449 | * |
450 | * Returns the selected index in the hash table for the given data. |
451 | */ |
452 | static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) |
453 | { |
454 | const struct batadv_nc_path *nc_path = data; |
455 | uint32_t hash = 0; |
456 | |
457 | hash = batadv_hash_bytes(hash, &nc_path->prev_hop, |
458 | sizeof(nc_path->prev_hop)); |
459 | hash = batadv_hash_bytes(hash, &nc_path->next_hop, |
460 | sizeof(nc_path->next_hop)); |
461 | |
462 | hash += (hash << 3); |
463 | hash ^= (hash >> 11); |
464 | hash += (hash << 15); |
465 | |
466 | return hash % size; |
467 | } |
468 | |
469 | /** |
470 | * batadv_nc_hash_compare - comparing function used in the network coding hash |
471 | * tables |
472 | * @node: node in the local table |
473 | * @data2: second object to compare the node to |
474 | * |
475 | * Returns 1 if the two entry are the same, 0 otherwise |
476 | */ |
477 | static int batadv_nc_hash_compare(const struct hlist_node *node, |
478 | const void *data2) |
479 | { |
480 | const struct batadv_nc_path *nc_path1, *nc_path2; |
481 | |
482 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); |
483 | nc_path2 = data2; |
484 | |
485 | /* Return 1 if the two keys are identical */ |
486 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, |
487 | sizeof(nc_path1->prev_hop)) != 0) |
488 | return 0; |
489 | |
490 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, |
491 | sizeof(nc_path1->next_hop)) != 0) |
492 | return 0; |
493 | |
494 | return 1; |
495 | } |
496 | |
497 | /** |
498 | * batadv_nc_hash_find - search for an existing nc path and return it |
499 | * @hash: hash table containing the nc path |
500 | * @data: search key |
501 | * |
502 | * Returns the nc_path if found, NULL otherwise. |
503 | */ |
504 | static struct batadv_nc_path * |
505 | batadv_nc_hash_find(struct batadv_hashtable *hash, |
506 | void *data) |
507 | { |
508 | struct hlist_head *head; |
509 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; |
510 | int index; |
511 | |
512 | if (!hash) |
513 | return NULL; |
514 | |
515 | index = batadv_nc_hash_choose(data, hash->size); |
516 | head = &hash->table[index]; |
517 | |
518 | rcu_read_lock(); |
519 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { |
520 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) |
521 | continue; |
522 | |
523 | if (!atomic_inc_not_zero(&nc_path->refcount)) |
524 | continue; |
525 | |
526 | nc_path_tmp = nc_path; |
527 | break; |
528 | } |
529 | rcu_read_unlock(); |
530 | |
531 | return nc_path_tmp; |
532 | } |
533 | |
534 | /** |
535 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct |
536 | * @nc_packet: the nc packet to send |
537 | */ |
538 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) |
539 | { |
540 | batadv_send_skb_packet(nc_packet->skb, |
541 | nc_packet->neigh_node->if_incoming, |
542 | nc_packet->nc_path->next_hop); |
543 | nc_packet->skb = NULL; |
544 | batadv_nc_packet_free(nc_packet); |
545 | } |
546 | |
547 | /** |
548 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. |
549 | * @bat_priv: the bat priv with all the soft interface information |
550 | * @nc_path: the nc path the packet belongs to |
551 | * @nc_packet: the nc packet to be checked |
552 | * |
553 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering |
554 | * timeout. If so, the packet is no longer kept and the entry deleted from the |
555 | * queue. Has to be called with the appropriate locks. |
556 | * |
557 | * Returns false as soon as the entry in the fifo queue has not been timed out |
558 | * yet and true otherwise. |
559 | */ |
560 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, |
561 | struct batadv_nc_path *nc_path, |
562 | struct batadv_nc_packet *nc_packet) |
563 | { |
564 | unsigned long timeout = bat_priv->nc.max_buffer_time; |
565 | bool res = false; |
566 | |
567 | /* Packets are added to tail, so the remaining packets did not time |
568 | * out and we can stop processing the current queue |
569 | */ |
570 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && |
571 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) |
572 | goto out; |
573 | |
574 | /* purge nc packet */ |
575 | list_del(&nc_packet->list); |
576 | batadv_nc_packet_free(nc_packet); |
577 | |
578 | res = true; |
579 | |
580 | out: |
581 | return res; |
582 | } |
583 | |
584 | /** |
585 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. |
586 | * @bat_priv: the bat priv with all the soft interface information |
587 | * @nc_path: the nc path the packet belongs to |
588 | * @nc_packet: the nc packet to be checked |
589 | * |
590 | * Checks whether the given nc packet has hit its forward timeout. If so, the |
591 | * packet is no longer delayed, immediately sent and the entry deleted from the |
592 | * queue. Has to be called with the appropriate locks. |
593 | * |
594 | * Returns false as soon as the entry in the fifo queue has not been timed out |
595 | * yet and true otherwise. |
596 | */ |
597 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, |
598 | struct batadv_nc_path *nc_path, |
599 | struct batadv_nc_packet *nc_packet) |
600 | { |
601 | unsigned long timeout = bat_priv->nc.max_fwd_delay; |
602 | |
603 | /* Packets are added to tail, so the remaining packets did not time |
604 | * out and we can stop processing the current queue |
605 | */ |
606 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && |
607 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) |
608 | return false; |
609 | |
610 | /* Send packet */ |
611 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); |
612 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, |
613 | nc_packet->skb->len + ETH_HLEN); |
614 | list_del(&nc_packet->list); |
615 | batadv_nc_send_packet(nc_packet); |
616 | |
617 | return true; |
618 | } |
619 | |
620 | /** |
621 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out |
622 | * nc packets |
623 | * @bat_priv: the bat priv with all the soft interface information |
624 | * @hash: to be processed hash table |
625 | * @process_fn: Function called to process given nc packet. Should return true |
626 | * to encourage this function to proceed with the next packet. |
627 | * Otherwise the rest of the current queue is skipped. |
628 | */ |
629 | static void |
630 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, |
631 | struct batadv_hashtable *hash, |
632 | bool (*process_fn)(struct batadv_priv *, |
633 | struct batadv_nc_path *, |
634 | struct batadv_nc_packet *)) |
635 | { |
636 | struct hlist_head *head; |
637 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; |
638 | struct batadv_nc_path *nc_path; |
639 | bool ret; |
640 | int i; |
641 | |
642 | if (!hash) |
643 | return; |
644 | |
645 | /* Loop hash table bins */ |
646 | for (i = 0; i < hash->size; i++) { |
647 | head = &hash->table[i]; |
648 | |
649 | /* Loop coding paths */ |
650 | rcu_read_lock(); |
651 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { |
652 | /* Loop packets */ |
653 | spin_lock_bh(&nc_path->packet_list_lock); |
654 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, |
655 | &nc_path->packet_list, list) { |
656 | ret = process_fn(bat_priv, nc_path, nc_packet); |
657 | if (!ret) |
658 | break; |
659 | } |
660 | spin_unlock_bh(&nc_path->packet_list_lock); |
661 | } |
662 | rcu_read_unlock(); |
663 | } |
664 | } |
665 | |
666 | /** |
667 | * batadv_nc_worker - periodic task for house keeping related to network coding |
668 | * @work: kernel work struct |
669 | */ |
670 | static void batadv_nc_worker(struct work_struct *work) |
671 | { |
672 | struct delayed_work *delayed_work; |
673 | struct batadv_priv_nc *priv_nc; |
674 | struct batadv_priv *bat_priv; |
675 | unsigned long timeout; |
676 | |
677 | delayed_work = container_of(work, struct delayed_work, work); |
678 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); |
679 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); |
680 | |
681 | batadv_nc_purge_orig_hash(bat_priv); |
682 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
683 | batadv_nc_to_purge_nc_path_coding); |
684 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
685 | batadv_nc_to_purge_nc_path_decoding); |
686 | |
687 | timeout = bat_priv->nc.max_fwd_delay; |
688 | |
689 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { |
690 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, |
691 | batadv_nc_fwd_flush); |
692 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
693 | } |
694 | |
695 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
696 | bat_priv->nc.max_buffer_time)) { |
697 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, |
698 | batadv_nc_sniffed_purge); |
699 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
700 | } |
701 | |
702 | /* Schedule a new check */ |
703 | batadv_nc_start_timer(bat_priv); |
704 | } |
705 | |
706 | /** |
707 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for |
708 | * coding or not |
709 | * @bat_priv: the bat priv with all the soft interface information |
710 | * @orig_node: neighboring orig node which may be used as nc candidate |
711 | * @ogm_packet: incoming ogm packet also used for the checks |
712 | * |
713 | * Returns true if: |
714 | * 1) The OGM must have the most recent sequence number. |
715 | * 2) The TTL must be decremented by one and only one. |
716 | * 3) The OGM must be received from the first hop from orig_node. |
717 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. |
718 | */ |
719 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, |
720 | struct batadv_orig_node *orig_node, |
721 | struct batadv_ogm_packet *ogm_packet) |
722 | { |
723 | if (orig_node->last_real_seqno != ntohl(ogm_packet->seqno)) |
724 | return false; |
725 | if (orig_node->last_ttl != ogm_packet->ttl + 1) |
726 | return false; |
727 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) |
728 | return false; |
729 | if (ogm_packet->tq < bat_priv->nc.min_tq) |
730 | return false; |
731 | |
732 | return true; |
733 | } |
734 | |
735 | /** |
736 | * batadv_nc_find_nc_node - search for an existing nc node and return it |
737 | * @orig_node: orig node originating the ogm packet |
738 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet |
739 | * (can be equal to orig_node) |
740 | * @in_coding: traverse incoming or outgoing network coding list |
741 | * |
742 | * Returns the nc_node if found, NULL otherwise. |
743 | */ |
744 | static struct batadv_nc_node |
745 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, |
746 | struct batadv_orig_node *orig_neigh_node, |
747 | bool in_coding) |
748 | { |
749 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; |
750 | struct list_head *list; |
751 | |
752 | if (in_coding) |
753 | list = &orig_neigh_node->in_coding_list; |
754 | else |
755 | list = &orig_neigh_node->out_coding_list; |
756 | |
757 | /* Traverse list of nc_nodes to orig_node */ |
758 | rcu_read_lock(); |
759 | list_for_each_entry_rcu(nc_node, list, list) { |
760 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) |
761 | continue; |
762 | |
763 | if (!atomic_inc_not_zero(&nc_node->refcount)) |
764 | continue; |
765 | |
766 | /* Found a match */ |
767 | nc_node_out = nc_node; |
768 | break; |
769 | } |
770 | rcu_read_unlock(); |
771 | |
772 | return nc_node_out; |
773 | } |
774 | |
775 | /** |
776 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was |
777 | * not found |
778 | * @bat_priv: the bat priv with all the soft interface information |
779 | * @orig_node: orig node originating the ogm packet |
780 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet |
781 | * (can be equal to orig_node) |
782 | * @in_coding: traverse incoming or outgoing network coding list |
783 | * |
784 | * Returns the nc_node if found or created, NULL in case of an error. |
785 | */ |
786 | static struct batadv_nc_node |
787 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, |
788 | struct batadv_orig_node *orig_node, |
789 | struct batadv_orig_node *orig_neigh_node, |
790 | bool in_coding) |
791 | { |
792 | struct batadv_nc_node *nc_node; |
793 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ |
794 | struct list_head *list; |
795 | |
796 | /* Check if nc_node is already added */ |
797 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); |
798 | |
799 | /* Node found */ |
800 | if (nc_node) |
801 | return nc_node; |
802 | |
803 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); |
804 | if (!nc_node) |
805 | return NULL; |
806 | |
807 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) |
808 | goto free; |
809 | |
810 | /* Initialize nc_node */ |
811 | INIT_LIST_HEAD(&nc_node->list); |
812 | memcpy(nc_node->addr, orig_node->orig, ETH_ALEN); |
813 | nc_node->orig_node = orig_neigh_node; |
814 | atomic_set(&nc_node->refcount, 2); |
815 | |
816 | /* Select ingoing or outgoing coding node */ |
817 | if (in_coding) { |
818 | lock = &orig_neigh_node->in_coding_list_lock; |
819 | list = &orig_neigh_node->in_coding_list; |
820 | } else { |
821 | lock = &orig_neigh_node->out_coding_list_lock; |
822 | list = &orig_neigh_node->out_coding_list; |
823 | } |
824 | |
825 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", |
826 | nc_node->addr, nc_node->orig_node->orig); |
827 | |
828 | /* Add nc_node to orig_node */ |
829 | spin_lock_bh(lock); |
830 | list_add_tail_rcu(&nc_node->list, list); |
831 | spin_unlock_bh(lock); |
832 | |
833 | return nc_node; |
834 | |
835 | free: |
836 | kfree(nc_node); |
837 | return NULL; |
838 | } |
839 | |
840 | /** |
841 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs |
842 | * (best called on incoming OGMs) |
843 | * @bat_priv: the bat priv with all the soft interface information |
844 | * @orig_node: orig node originating the ogm packet |
845 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet |
846 | * (can be equal to orig_node) |
847 | * @ogm_packet: incoming ogm packet |
848 | * @is_single_hop_neigh: orig_node is a single hop neighbor |
849 | */ |
850 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, |
851 | struct batadv_orig_node *orig_node, |
852 | struct batadv_orig_node *orig_neigh_node, |
853 | struct batadv_ogm_packet *ogm_packet, |
854 | int is_single_hop_neigh) |
855 | { |
856 | struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL; |
857 | |
858 | /* Check if network coding is enabled */ |
859 | if (!atomic_read(&bat_priv->network_coding)) |
860 | goto out; |
861 | |
862 | /* check if orig node is network coding enabled */ |
863 | if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC)) |
864 | goto out; |
865 | |
866 | /* accept ogms from 'good' neighbors and single hop neighbors */ |
867 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && |
868 | !is_single_hop_neigh) |
869 | goto out; |
870 | |
871 | /* Add orig_node as in_nc_node on hop */ |
872 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, |
873 | orig_neigh_node, true); |
874 | if (!in_nc_node) |
875 | goto out; |
876 | |
877 | in_nc_node->last_seen = jiffies; |
878 | |
879 | /* Add hop as out_nc_node on orig_node */ |
880 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, |
881 | orig_node, false); |
882 | if (!out_nc_node) |
883 | goto out; |
884 | |
885 | out_nc_node->last_seen = jiffies; |
886 | |
887 | out: |
888 | if (in_nc_node) |
889 | batadv_nc_node_free_ref(in_nc_node); |
890 | if (out_nc_node) |
891 | batadv_nc_node_free_ref(out_nc_node); |
892 | } |
893 | |
894 | /** |
895 | * batadv_nc_get_path - get existing nc_path or allocate a new one |
896 | * @bat_priv: the bat priv with all the soft interface information |
897 | * @hash: hash table containing the nc path |
898 | * @src: ethernet source address - first half of the nc path search key |
899 | * @dst: ethernet destination address - second half of the nc path search key |
900 | * |
901 | * Returns pointer to nc_path if the path was found or created, returns NULL |
902 | * on error. |
903 | */ |
904 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, |
905 | struct batadv_hashtable *hash, |
906 | uint8_t *src, |
907 | uint8_t *dst) |
908 | { |
909 | int hash_added; |
910 | struct batadv_nc_path *nc_path, nc_path_key; |
911 | |
912 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); |
913 | |
914 | /* Search for existing nc_path */ |
915 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); |
916 | |
917 | if (nc_path) { |
918 | /* Set timestamp to delay removal of nc_path */ |
919 | nc_path->last_valid = jiffies; |
920 | return nc_path; |
921 | } |
922 | |
923 | /* No existing nc_path was found; create a new */ |
924 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); |
925 | |
926 | if (!nc_path) |
927 | return NULL; |
928 | |
929 | /* Initialize nc_path */ |
930 | INIT_LIST_HEAD(&nc_path->packet_list); |
931 | spin_lock_init(&nc_path->packet_list_lock); |
932 | atomic_set(&nc_path->refcount, 2); |
933 | nc_path->last_valid = jiffies; |
934 | memcpy(nc_path->next_hop, dst, ETH_ALEN); |
935 | memcpy(nc_path->prev_hop, src, ETH_ALEN); |
936 | |
937 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", |
938 | nc_path->prev_hop, |
939 | nc_path->next_hop); |
940 | |
941 | /* Add nc_path to hash table */ |
942 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, |
943 | batadv_nc_hash_choose, &nc_path_key, |
944 | &nc_path->hash_entry); |
945 | |
946 | if (hash_added < 0) { |
947 | kfree(nc_path); |
948 | return NULL; |
949 | } |
950 | |
951 | return nc_path; |
952 | } |
953 | |
954 | /** |
955 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair |
956 | * selection of a receiver with slightly lower TQ than the other |
957 | * @tq: to be weighted tq value |
958 | */ |
959 | static uint8_t batadv_nc_random_weight_tq(uint8_t tq) |
960 | { |
961 | uint8_t rand_val, rand_tq; |
962 | |
963 | get_random_bytes(&rand_val, sizeof(rand_val)); |
964 | |
965 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ |
966 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); |
967 | |
968 | /* normalize the randomized packet loss */ |
969 | rand_tq /= BATADV_TQ_MAX_VALUE; |
970 | |
971 | /* convert to (randomized) estimated tq again */ |
972 | return BATADV_TQ_MAX_VALUE - rand_tq; |
973 | } |
974 | |
975 | /** |
976 | * batadv_nc_memxor - XOR destination with source |
977 | * @dst: byte array to XOR into |
978 | * @src: byte array to XOR from |
979 | * @len: length of destination array |
980 | */ |
981 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) |
982 | { |
983 | unsigned int i; |
984 | |
985 | for (i = 0; i < len; ++i) |
986 | dst[i] ^= src[i]; |
987 | } |
988 | |
989 | /** |
990 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet |
991 | * into a coded_packet and send it |
992 | * @bat_priv: the bat priv with all the soft interface information |
993 | * @skb: data skb to forward |
994 | * @ethhdr: pointer to the ethernet header inside the skb |
995 | * @nc_packet: structure containing the packet to the skb can be coded with |
996 | * @neigh_node: next hop to forward packet to |
997 | * |
998 | * Returns true if both packets are consumed, false otherwise. |
999 | */ |
1000 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, |
1001 | struct sk_buff *skb, |
1002 | struct ethhdr *ethhdr, |
1003 | struct batadv_nc_packet *nc_packet, |
1004 | struct batadv_neigh_node *neigh_node) |
1005 | { |
1006 | uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp; |
1007 | struct sk_buff *skb_dest, *skb_src; |
1008 | struct batadv_unicast_packet *packet1; |
1009 | struct batadv_unicast_packet *packet2; |
1010 | struct batadv_coded_packet *coded_packet; |
1011 | struct batadv_neigh_node *neigh_tmp, *router_neigh; |
1012 | struct batadv_neigh_node *router_coding = NULL; |
1013 | uint8_t *first_source, *first_dest, *second_source, *second_dest; |
1014 | __be32 packet_id1, packet_id2; |
1015 | size_t count; |
1016 | bool res = false; |
1017 | int coding_len; |
1018 | int unicast_size = sizeof(*packet1); |
1019 | int coded_size = sizeof(*coded_packet); |
1020 | int header_add = coded_size - unicast_size; |
1021 | |
1022 | router_neigh = batadv_orig_node_get_router(neigh_node->orig_node); |
1023 | if (!router_neigh) |
1024 | goto out; |
1025 | |
1026 | neigh_tmp = nc_packet->neigh_node; |
1027 | router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node); |
1028 | if (!router_coding) |
1029 | goto out; |
1030 | |
1031 | tq_tmp = batadv_nc_random_weight_tq(router_neigh->bat_iv.tq_avg); |
1032 | tq_weighted_neigh = tq_tmp; |
1033 | tq_tmp = batadv_nc_random_weight_tq(router_coding->bat_iv.tq_avg); |
1034 | tq_weighted_coding = tq_tmp; |
1035 | |
1036 | /* Select one destination for the MAC-header dst-field based on |
1037 | * weighted TQ-values. |
1038 | */ |
1039 | if (tq_weighted_neigh >= tq_weighted_coding) { |
1040 | /* Destination from nc_packet is selected for MAC-header */ |
1041 | first_dest = nc_packet->nc_path->next_hop; |
1042 | first_source = nc_packet->nc_path->prev_hop; |
1043 | second_dest = neigh_node->addr; |
1044 | second_source = ethhdr->h_source; |
1045 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; |
1046 | packet2 = (struct batadv_unicast_packet *)skb->data; |
1047 | packet_id1 = nc_packet->packet_id; |
1048 | packet_id2 = batadv_skb_crc32(skb, |
1049 | skb->data + sizeof(*packet2)); |
1050 | } else { |
1051 | /* Destination for skb is selected for MAC-header */ |
1052 | first_dest = neigh_node->addr; |
1053 | first_source = ethhdr->h_source; |
1054 | second_dest = nc_packet->nc_path->next_hop; |
1055 | second_source = nc_packet->nc_path->prev_hop; |
1056 | packet1 = (struct batadv_unicast_packet *)skb->data; |
1057 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; |
1058 | packet_id1 = batadv_skb_crc32(skb, |
1059 | skb->data + sizeof(*packet1)); |
1060 | packet_id2 = nc_packet->packet_id; |
1061 | } |
1062 | |
1063 | /* Instead of zero padding the smallest data buffer, we |
1064 | * code into the largest. |
1065 | */ |
1066 | if (skb->len <= nc_packet->skb->len) { |
1067 | skb_dest = nc_packet->skb; |
1068 | skb_src = skb; |
1069 | } else { |
1070 | skb_dest = skb; |
1071 | skb_src = nc_packet->skb; |
1072 | } |
1073 | |
1074 | /* coding_len is used when decoding the packet shorter packet */ |
1075 | coding_len = skb_src->len - unicast_size; |
1076 | |
1077 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) |
1078 | goto out; |
1079 | |
1080 | skb_push(skb_dest, header_add); |
1081 | |
1082 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; |
1083 | skb_reset_mac_header(skb_dest); |
1084 | |
1085 | coded_packet->packet_type = BATADV_CODED; |
1086 | coded_packet->version = BATADV_COMPAT_VERSION; |
1087 | coded_packet->ttl = packet1->ttl; |
1088 | |
1089 | /* Info about first unicast packet */ |
1090 | memcpy(coded_packet->first_source, first_source, ETH_ALEN); |
1091 | memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN); |
1092 | coded_packet->first_crc = packet_id1; |
1093 | coded_packet->first_ttvn = packet1->ttvn; |
1094 | |
1095 | /* Info about second unicast packet */ |
1096 | memcpy(coded_packet->second_dest, second_dest, ETH_ALEN); |
1097 | memcpy(coded_packet->second_source, second_source, ETH_ALEN); |
1098 | memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN); |
1099 | coded_packet->second_crc = packet_id2; |
1100 | coded_packet->second_ttl = packet2->ttl; |
1101 | coded_packet->second_ttvn = packet2->ttvn; |
1102 | coded_packet->coded_len = htons(coding_len); |
1103 | |
1104 | /* This is where the magic happens: Code skb_src into skb_dest */ |
1105 | batadv_nc_memxor(skb_dest->data + coded_size, |
1106 | skb_src->data + unicast_size, coding_len); |
1107 | |
1108 | /* Update counters accordingly */ |
1109 | if (BATADV_SKB_CB(skb_src)->decoded && |
1110 | BATADV_SKB_CB(skb_dest)->decoded) { |
1111 | /* Both packets are recoded */ |
1112 | count = skb_src->len + ETH_HLEN; |
1113 | count += skb_dest->len + ETH_HLEN; |
1114 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); |
1115 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); |
1116 | } else if (!BATADV_SKB_CB(skb_src)->decoded && |
1117 | !BATADV_SKB_CB(skb_dest)->decoded) { |
1118 | /* Both packets are newly coded */ |
1119 | count = skb_src->len + ETH_HLEN; |
1120 | count += skb_dest->len + ETH_HLEN; |
1121 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); |
1122 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); |
1123 | } else if (BATADV_SKB_CB(skb_src)->decoded && |
1124 | !BATADV_SKB_CB(skb_dest)->decoded) { |
1125 | /* skb_src recoded and skb_dest is newly coded */ |
1126 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); |
1127 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, |
1128 | skb_src->len + ETH_HLEN); |
1129 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); |
1130 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, |
1131 | skb_dest->len + ETH_HLEN); |
1132 | } else if (!BATADV_SKB_CB(skb_src)->decoded && |
1133 | BATADV_SKB_CB(skb_dest)->decoded) { |
1134 | /* skb_src is newly coded and skb_dest is recoded */ |
1135 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); |
1136 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, |
1137 | skb_src->len + ETH_HLEN); |
1138 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); |
1139 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, |
1140 | skb_dest->len + ETH_HLEN); |
1141 | } |
1142 | |
1143 | /* skb_src is now coded into skb_dest, so free it */ |
1144 | kfree_skb(skb_src); |
1145 | |
1146 | /* avoid duplicate free of skb from nc_packet */ |
1147 | nc_packet->skb = NULL; |
1148 | batadv_nc_packet_free(nc_packet); |
1149 | |
1150 | /* Send the coded packet and return true */ |
1151 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); |
1152 | res = true; |
1153 | out: |
1154 | if (router_neigh) |
1155 | batadv_neigh_node_free_ref(router_neigh); |
1156 | if (router_coding) |
1157 | batadv_neigh_node_free_ref(router_coding); |
1158 | return res; |
1159 | } |
1160 | |
1161 | /** |
1162 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. |
1163 | * @skb: data skb to forward |
1164 | * @dst: destination mac address of the other skb to code with |
1165 | * @src: source mac address of skb |
1166 | * |
1167 | * Whenever we network code a packet we have to check whether we received it in |
1168 | * a network coded form. If so, we may not be able to use it for coding because |
1169 | * some neighbors may also have received (overheard) the packet in the network |
1170 | * coded form without being able to decode it. It is hard to know which of the |
1171 | * neighboring nodes was able to decode the packet, therefore we can only |
1172 | * re-code the packet if the source of the previous encoded packet is involved. |
1173 | * Since the source encoded the packet we can be certain it has all necessary |
1174 | * decode information. |
1175 | * |
1176 | * Returns true if coding of a decoded packet is allowed. |
1177 | */ |
1178 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, |
1179 | uint8_t *dst, uint8_t *src) |
1180 | { |
1181 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) |
1182 | return false; |
1183 | else |
1184 | return true; |
1185 | } |
1186 | |
1187 | /** |
1188 | * batadv_nc_path_search - Find the coding path matching in_nc_node and |
1189 | * out_nc_node to retrieve a buffered packet that can be used for coding. |
1190 | * @bat_priv: the bat priv with all the soft interface information |
1191 | * @in_nc_node: pointer to skb next hop's neighbor nc node |
1192 | * @out_nc_node: pointer to skb source's neighbor nc node |
1193 | * @skb: data skb to forward |
1194 | * @eth_dst: next hop mac address of skb |
1195 | * |
1196 | * Returns true if coding of a decoded skb is allowed. |
1197 | */ |
1198 | static struct batadv_nc_packet * |
1199 | batadv_nc_path_search(struct batadv_priv *bat_priv, |
1200 | struct batadv_nc_node *in_nc_node, |
1201 | struct batadv_nc_node *out_nc_node, |
1202 | struct sk_buff *skb, |
1203 | uint8_t *eth_dst) |
1204 | { |
1205 | struct batadv_nc_path *nc_path, nc_path_key; |
1206 | struct batadv_nc_packet *nc_packet_out = NULL; |
1207 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; |
1208 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; |
1209 | int idx; |
1210 | |
1211 | if (!hash) |
1212 | return NULL; |
1213 | |
1214 | /* Create almost path key */ |
1215 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, |
1216 | out_nc_node->addr); |
1217 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); |
1218 | |
1219 | /* Check for coding opportunities in this nc_path */ |
1220 | rcu_read_lock(); |
1221 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { |
1222 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) |
1223 | continue; |
1224 | |
1225 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) |
1226 | continue; |
1227 | |
1228 | spin_lock_bh(&nc_path->packet_list_lock); |
1229 | if (list_empty(&nc_path->packet_list)) { |
1230 | spin_unlock_bh(&nc_path->packet_list_lock); |
1231 | continue; |
1232 | } |
1233 | |
1234 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, |
1235 | &nc_path->packet_list, list) { |
1236 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, |
1237 | eth_dst, |
1238 | in_nc_node->addr)) |
1239 | continue; |
1240 | |
1241 | /* Coding opportunity is found! */ |
1242 | list_del(&nc_packet->list); |
1243 | nc_packet_out = nc_packet; |
1244 | break; |
1245 | } |
1246 | |
1247 | spin_unlock_bh(&nc_path->packet_list_lock); |
1248 | break; |
1249 | } |
1250 | rcu_read_unlock(); |
1251 | |
1252 | return nc_packet_out; |
1253 | } |
1254 | |
1255 | /** |
1256 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the |
1257 | * skb's sender (may be equal to the originator). |
1258 | * @bat_priv: the bat priv with all the soft interface information |
1259 | * @skb: data skb to forward |
1260 | * @eth_dst: next hop mac address of skb |
1261 | * @eth_src: source mac address of skb |
1262 | * @in_nc_node: pointer to skb next hop's neighbor nc node |
1263 | * |
1264 | * Returns an nc packet if a suitable coding packet was found, NULL otherwise. |
1265 | */ |
1266 | static struct batadv_nc_packet * |
1267 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, |
1268 | struct sk_buff *skb, |
1269 | uint8_t *eth_dst, |
1270 | uint8_t *eth_src, |
1271 | struct batadv_nc_node *in_nc_node) |
1272 | { |
1273 | struct batadv_orig_node *orig_node; |
1274 | struct batadv_nc_node *out_nc_node; |
1275 | struct batadv_nc_packet *nc_packet = NULL; |
1276 | |
1277 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); |
1278 | if (!orig_node) |
1279 | return NULL; |
1280 | |
1281 | rcu_read_lock(); |
1282 | list_for_each_entry_rcu(out_nc_node, |
1283 | &orig_node->out_coding_list, list) { |
1284 | /* Check if the skb is decoded and if recoding is possible */ |
1285 | if (!batadv_nc_skb_coding_possible(skb, |
1286 | out_nc_node->addr, eth_src)) |
1287 | continue; |
1288 | |
1289 | /* Search for an opportunity in this nc_path */ |
1290 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, |
1291 | out_nc_node, skb, eth_dst); |
1292 | if (nc_packet) |
1293 | break; |
1294 | } |
1295 | rcu_read_unlock(); |
1296 | |
1297 | batadv_orig_node_free_ref(orig_node); |
1298 | return nc_packet; |
1299 | } |
1300 | |
1301 | /** |
1302 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the |
1303 | * unicast skb before it is stored for use in later decoding |
1304 | * @bat_priv: the bat priv with all the soft interface information |
1305 | * @skb: data skb to store |
1306 | * @eth_dst_new: new destination mac address of skb |
1307 | */ |
1308 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, |
1309 | struct sk_buff *skb, |
1310 | uint8_t *eth_dst_new) |
1311 | { |
1312 | struct ethhdr *ethhdr; |
1313 | |
1314 | /* Copy skb header to change the mac header */ |
1315 | skb = pskb_copy(skb, GFP_ATOMIC); |
1316 | if (!skb) |
1317 | return; |
1318 | |
1319 | /* Set the mac header as if we actually sent the packet uncoded */ |
1320 | ethhdr = eth_hdr(skb); |
1321 | memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN); |
1322 | memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN); |
1323 | |
1324 | /* Set data pointer to MAC header to mimic packets from our tx path */ |
1325 | skb_push(skb, ETH_HLEN); |
1326 | |
1327 | /* Add the packet to the decoding packet pool */ |
1328 | batadv_nc_skb_store_for_decoding(bat_priv, skb); |
1329 | |
1330 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free |
1331 | * our ref |
1332 | */ |
1333 | kfree_skb(skb); |
1334 | } |
1335 | |
1336 | /** |
1337 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. |
1338 | * @skb: data skb to forward |
1339 | * @neigh_node: next hop to forward packet to |
1340 | * @ethhdr: pointer to the ethernet header inside the skb |
1341 | * |
1342 | * Loops through list of neighboring nodes the next hop has a good connection to |
1343 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our |
1344 | * next hop that potentially sent a packet which our next hop also received |
1345 | * (overheard) and has stored for later decoding. |
1346 | * |
1347 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise |
1348 | */ |
1349 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, |
1350 | struct batadv_neigh_node *neigh_node, |
1351 | struct ethhdr *ethhdr) |
1352 | { |
1353 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; |
1354 | struct batadv_priv *bat_priv = netdev_priv(netdev); |
1355 | struct batadv_orig_node *orig_node = neigh_node->orig_node; |
1356 | struct batadv_nc_node *nc_node; |
1357 | struct batadv_nc_packet *nc_packet = NULL; |
1358 | |
1359 | rcu_read_lock(); |
1360 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { |
1361 | /* Search for coding opportunity with this in_nc_node */ |
1362 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, |
1363 | neigh_node->addr, |
1364 | ethhdr->h_source, nc_node); |
1365 | |
1366 | /* Opportunity was found, so stop searching */ |
1367 | if (nc_packet) |
1368 | break; |
1369 | } |
1370 | rcu_read_unlock(); |
1371 | |
1372 | if (!nc_packet) |
1373 | return false; |
1374 | |
1375 | /* Save packets for later decoding */ |
1376 | batadv_nc_skb_store_before_coding(bat_priv, skb, |
1377 | neigh_node->addr); |
1378 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, |
1379 | nc_packet->neigh_node->addr); |
1380 | |
1381 | /* Code and send packets */ |
1382 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, |
1383 | neigh_node)) |
1384 | return true; |
1385 | |
1386 | /* out of mem ? Coding failed - we have to free the buffered packet |
1387 | * to avoid memleaks. The skb passed as argument will be dealt with |
1388 | * by the calling function. |
1389 | */ |
1390 | batadv_nc_send_packet(nc_packet); |
1391 | return false; |
1392 | } |
1393 | |
1394 | /** |
1395 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding |
1396 | * @skb: skb to add to path |
1397 | * @nc_path: path to add skb to |
1398 | * @neigh_node: next hop to forward packet to |
1399 | * @packet_id: checksum to identify packet |
1400 | * |
1401 | * Returns true if the packet was buffered or false in case of an error. |
1402 | */ |
1403 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, |
1404 | struct batadv_nc_path *nc_path, |
1405 | struct batadv_neigh_node *neigh_node, |
1406 | __be32 packet_id) |
1407 | { |
1408 | struct batadv_nc_packet *nc_packet; |
1409 | |
1410 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); |
1411 | if (!nc_packet) |
1412 | return false; |
1413 | |
1414 | /* Initialize nc_packet */ |
1415 | nc_packet->timestamp = jiffies; |
1416 | nc_packet->packet_id = packet_id; |
1417 | nc_packet->skb = skb; |
1418 | nc_packet->neigh_node = neigh_node; |
1419 | nc_packet->nc_path = nc_path; |
1420 | |
1421 | /* Add coding packet to list */ |
1422 | spin_lock_bh(&nc_path->packet_list_lock); |
1423 | list_add_tail(&nc_packet->list, &nc_path->packet_list); |
1424 | spin_unlock_bh(&nc_path->packet_list_lock); |
1425 | |
1426 | return true; |
1427 | } |
1428 | |
1429 | /** |
1430 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet |
1431 | * buffer |
1432 | * @skb: data skb to forward |
1433 | * @neigh_node: next hop to forward packet to |
1434 | * |
1435 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise |
1436 | */ |
1437 | bool batadv_nc_skb_forward(struct sk_buff *skb, |
1438 | struct batadv_neigh_node *neigh_node) |
1439 | { |
1440 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; |
1441 | struct batadv_priv *bat_priv = netdev_priv(netdev); |
1442 | struct batadv_unicast_packet *packet; |
1443 | struct batadv_nc_path *nc_path; |
1444 | struct ethhdr *ethhdr = eth_hdr(skb); |
1445 | __be32 packet_id; |
1446 | u8 *payload; |
1447 | |
1448 | /* Check if network coding is enabled */ |
1449 | if (!atomic_read(&bat_priv->network_coding)) |
1450 | goto out; |
1451 | |
1452 | /* We only handle unicast packets */ |
1453 | payload = skb_network_header(skb); |
1454 | packet = (struct batadv_unicast_packet *)payload; |
1455 | if (packet->packet_type != BATADV_UNICAST) |
1456 | goto out; |
1457 | |
1458 | /* Try to find a coding opportunity and send the skb if one is found */ |
1459 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) |
1460 | return true; |
1461 | |
1462 | /* Find or create a nc_path for this src-dst pair */ |
1463 | nc_path = batadv_nc_get_path(bat_priv, |
1464 | bat_priv->nc.coding_hash, |
1465 | ethhdr->h_source, |
1466 | neigh_node->addr); |
1467 | |
1468 | if (!nc_path) |
1469 | goto out; |
1470 | |
1471 | /* Add skb to nc_path */ |
1472 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); |
1473 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) |
1474 | goto free_nc_path; |
1475 | |
1476 | /* Packet is consumed */ |
1477 | return true; |
1478 | |
1479 | free_nc_path: |
1480 | batadv_nc_path_free_ref(nc_path); |
1481 | out: |
1482 | /* Packet is not consumed */ |
1483 | return false; |
1484 | } |
1485 | |
1486 | /** |
1487 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used |
1488 | * when decoding coded packets |
1489 | * @bat_priv: the bat priv with all the soft interface information |
1490 | * @skb: data skb to store |
1491 | */ |
1492 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, |
1493 | struct sk_buff *skb) |
1494 | { |
1495 | struct batadv_unicast_packet *packet; |
1496 | struct batadv_nc_path *nc_path; |
1497 | struct ethhdr *ethhdr = eth_hdr(skb); |
1498 | __be32 packet_id; |
1499 | u8 *payload; |
1500 | |
1501 | /* Check if network coding is enabled */ |
1502 | if (!atomic_read(&bat_priv->network_coding)) |
1503 | goto out; |
1504 | |
1505 | /* Check for supported packet type */ |
1506 | payload = skb_network_header(skb); |
1507 | packet = (struct batadv_unicast_packet *)payload; |
1508 | if (packet->packet_type != BATADV_UNICAST) |
1509 | goto out; |
1510 | |
1511 | /* Find existing nc_path or create a new */ |
1512 | nc_path = batadv_nc_get_path(bat_priv, |
1513 | bat_priv->nc.decoding_hash, |
1514 | ethhdr->h_source, |
1515 | ethhdr->h_dest); |
1516 | |
1517 | if (!nc_path) |
1518 | goto out; |
1519 | |
1520 | /* Clone skb and adjust skb->data to point at batman header */ |
1521 | skb = skb_clone(skb, GFP_ATOMIC); |
1522 | if (unlikely(!skb)) |
1523 | goto free_nc_path; |
1524 | |
1525 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) |
1526 | goto free_skb; |
1527 | |
1528 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) |
1529 | goto free_skb; |
1530 | |
1531 | /* Add skb to nc_path */ |
1532 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); |
1533 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) |
1534 | goto free_skb; |
1535 | |
1536 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); |
1537 | return; |
1538 | |
1539 | free_skb: |
1540 | kfree_skb(skb); |
1541 | free_nc_path: |
1542 | batadv_nc_path_free_ref(nc_path); |
1543 | out: |
1544 | return; |
1545 | } |
1546 | |
1547 | /** |
1548 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet |
1549 | * should be saved in the decoding buffer and, if so, store it there |
1550 | * @bat_priv: the bat priv with all the soft interface information |
1551 | * @skb: unicast skb to store |
1552 | */ |
1553 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, |
1554 | struct sk_buff *skb) |
1555 | { |
1556 | struct ethhdr *ethhdr = eth_hdr(skb); |
1557 | |
1558 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
1559 | return; |
1560 | |
1561 | /* Set data pointer to MAC header to mimic packets from our tx path */ |
1562 | skb_push(skb, ETH_HLEN); |
1563 | |
1564 | batadv_nc_skb_store_for_decoding(bat_priv, skb); |
1565 | } |
1566 | |
1567 | /** |
1568 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored |
1569 | * in nc_packet |
1570 | * @bat_priv: the bat priv with all the soft interface information |
1571 | * @skb: unicast skb to decode |
1572 | * @nc_packet: decode data needed to decode the skb |
1573 | * |
1574 | * Returns pointer to decoded unicast packet if the packet was decoded or NULL |
1575 | * in case of an error. |
1576 | */ |
1577 | static struct batadv_unicast_packet * |
1578 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
1579 | struct batadv_nc_packet *nc_packet) |
1580 | { |
1581 | const int h_size = sizeof(struct batadv_unicast_packet); |
1582 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; |
1583 | struct batadv_unicast_packet *unicast_packet; |
1584 | struct batadv_coded_packet coded_packet_tmp; |
1585 | struct ethhdr *ethhdr, ethhdr_tmp; |
1586 | uint8_t *orig_dest, ttl, ttvn; |
1587 | unsigned int coding_len; |
1588 | int err; |
1589 | |
1590 | /* Save headers temporarily */ |
1591 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); |
1592 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); |
1593 | |
1594 | if (skb_cow(skb, 0) < 0) |
1595 | return NULL; |
1596 | |
1597 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) |
1598 | return NULL; |
1599 | |
1600 | /* Data points to batman header, so set mac header 14 bytes before |
1601 | * and network to data |
1602 | */ |
1603 | skb_set_mac_header(skb, -ETH_HLEN); |
1604 | skb_reset_network_header(skb); |
1605 | |
1606 | /* Reconstruct original mac header */ |
1607 | ethhdr = eth_hdr(skb); |
1608 | memcpy(ethhdr, ðhdr_tmp, sizeof(*ethhdr)); |
1609 | |
1610 | /* Select the correct unicast header information based on the location |
1611 | * of our mac address in the coded_packet header |
1612 | */ |
1613 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
1614 | /* If we are the second destination the packet was overheard, |
1615 | * so the Ethernet address must be copied to h_dest and |
1616 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST |
1617 | */ |
1618 | memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN); |
1619 | skb->pkt_type = PACKET_HOST; |
1620 | |
1621 | orig_dest = coded_packet_tmp.second_orig_dest; |
1622 | ttl = coded_packet_tmp.second_ttl; |
1623 | ttvn = coded_packet_tmp.second_ttvn; |
1624 | } else { |
1625 | orig_dest = coded_packet_tmp.first_orig_dest; |
1626 | ttl = coded_packet_tmp.ttl; |
1627 | ttvn = coded_packet_tmp.first_ttvn; |
1628 | } |
1629 | |
1630 | coding_len = ntohs(coded_packet_tmp.coded_len); |
1631 | |
1632 | if (coding_len > skb->len) |
1633 | return NULL; |
1634 | |
1635 | /* Here the magic is reversed: |
1636 | * extract the missing packet from the received coded packet |
1637 | */ |
1638 | batadv_nc_memxor(skb->data + h_size, |
1639 | nc_packet->skb->data + h_size, |
1640 | coding_len); |
1641 | |
1642 | /* Resize decoded skb if decoded with larger packet */ |
1643 | if (nc_packet->skb->len > coding_len + h_size) { |
1644 | err = pskb_trim_rcsum(skb, coding_len + h_size); |
1645 | if (err) |
1646 | return NULL; |
1647 | } |
1648 | |
1649 | /* Create decoded unicast packet */ |
1650 | unicast_packet = (struct batadv_unicast_packet *)skb->data; |
1651 | unicast_packet->packet_type = BATADV_UNICAST; |
1652 | unicast_packet->version = BATADV_COMPAT_VERSION; |
1653 | unicast_packet->ttl = ttl; |
1654 | memcpy(unicast_packet->dest, orig_dest, ETH_ALEN); |
1655 | unicast_packet->ttvn = ttvn; |
1656 | |
1657 | batadv_nc_packet_free(nc_packet); |
1658 | return unicast_packet; |
1659 | } |
1660 | |
1661 | /** |
1662 | * batadv_nc_find_decoding_packet - search through buffered decoding data to |
1663 | * find the data needed to decode the coded packet |
1664 | * @bat_priv: the bat priv with all the soft interface information |
1665 | * @ethhdr: pointer to the ethernet header inside the coded packet |
1666 | * @coded: coded packet we try to find decode data for |
1667 | * |
1668 | * Returns pointer to nc packet if the needed data was found or NULL otherwise. |
1669 | */ |
1670 | static struct batadv_nc_packet * |
1671 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, |
1672 | struct ethhdr *ethhdr, |
1673 | struct batadv_coded_packet *coded) |
1674 | { |
1675 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; |
1676 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; |
1677 | struct batadv_nc_path *nc_path, nc_path_key; |
1678 | uint8_t *dest, *source; |
1679 | __be32 packet_id; |
1680 | int index; |
1681 | |
1682 | if (!hash) |
1683 | return NULL; |
1684 | |
1685 | /* Select the correct packet id based on the location of our mac-addr */ |
1686 | dest = ethhdr->h_source; |
1687 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
1688 | source = coded->second_source; |
1689 | packet_id = coded->second_crc; |
1690 | } else { |
1691 | source = coded->first_source; |
1692 | packet_id = coded->first_crc; |
1693 | } |
1694 | |
1695 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); |
1696 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); |
1697 | |
1698 | /* Search for matching coding path */ |
1699 | rcu_read_lock(); |
1700 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { |
1701 | /* Find matching nc_packet */ |
1702 | spin_lock_bh(&nc_path->packet_list_lock); |
1703 | list_for_each_entry(tmp_nc_packet, |
1704 | &nc_path->packet_list, list) { |
1705 | if (packet_id == tmp_nc_packet->packet_id) { |
1706 | list_del(&tmp_nc_packet->list); |
1707 | |
1708 | nc_packet = tmp_nc_packet; |
1709 | break; |
1710 | } |
1711 | } |
1712 | spin_unlock_bh(&nc_path->packet_list_lock); |
1713 | |
1714 | if (nc_packet) |
1715 | break; |
1716 | } |
1717 | rcu_read_unlock(); |
1718 | |
1719 | if (!nc_packet) |
1720 | batadv_dbg(BATADV_DBG_NC, bat_priv, |
1721 | "No decoding packet found for %u\n", packet_id); |
1722 | |
1723 | return nc_packet; |
1724 | } |
1725 | |
1726 | /** |
1727 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the |
1728 | * resulting unicast packet |
1729 | * @skb: incoming coded packet |
1730 | * @recv_if: pointer to interface this packet was received on |
1731 | */ |
1732 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
1733 | struct batadv_hard_iface *recv_if) |
1734 | { |
1735 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); |
1736 | struct batadv_unicast_packet *unicast_packet; |
1737 | struct batadv_coded_packet *coded_packet; |
1738 | struct batadv_nc_packet *nc_packet; |
1739 | struct ethhdr *ethhdr; |
1740 | int hdr_size = sizeof(*coded_packet); |
1741 | |
1742 | /* Check if network coding is enabled */ |
1743 | if (!atomic_read(&bat_priv->network_coding)) |
1744 | return NET_RX_DROP; |
1745 | |
1746 | /* Make sure we can access (and remove) header */ |
1747 | if (unlikely(!pskb_may_pull(skb, hdr_size))) |
1748 | return NET_RX_DROP; |
1749 | |
1750 | coded_packet = (struct batadv_coded_packet *)skb->data; |
1751 | ethhdr = eth_hdr(skb); |
1752 | |
1753 | /* Verify frame is destined for us */ |
1754 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1755 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
1756 | return NET_RX_DROP; |
1757 | |
1758 | /* Update stat counter */ |
1759 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
1760 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1761 | |
1762 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, |
1763 | coded_packet); |
1764 | if (!nc_packet) { |
1765 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); |
1766 | return NET_RX_DROP; |
1767 | } |
1768 | |
1769 | /* Make skb's linear, because decoding accesses the entire buffer */ |
1770 | if (skb_linearize(skb) < 0) |
1771 | goto free_nc_packet; |
1772 | |
1773 | if (skb_linearize(nc_packet->skb) < 0) |
1774 | goto free_nc_packet; |
1775 | |
1776 | /* Decode the packet */ |
1777 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
1778 | if (!unicast_packet) { |
1779 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); |
1780 | goto free_nc_packet; |
1781 | } |
1782 | |
1783 | /* Mark packet as decoded to do correct recoding when forwarding */ |
1784 | BATADV_SKB_CB(skb)->decoded = true; |
1785 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); |
1786 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, |
1787 | skb->len + ETH_HLEN); |
1788 | return batadv_recv_unicast_packet(skb, recv_if); |
1789 | |
1790 | free_nc_packet: |
1791 | batadv_nc_packet_free(nc_packet); |
1792 | return NET_RX_DROP; |
1793 | } |
1794 | |
1795 | /** |
1796 | * batadv_nc_mesh_free - clean up network coding memory |
1797 | * @bat_priv: the bat priv with all the soft interface information |
1798 | */ |
1799 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
1800 | { |
1801 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1802 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1803 | cancel_delayed_work_sync(&bat_priv->nc.work); |
1804 | |
1805 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1806 | batadv_hash_destroy(bat_priv->nc.coding_hash); |
1807 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1808 | batadv_hash_destroy(bat_priv->nc.decoding_hash); |
1809 | } |
1810 | |
1811 | /** |
1812 | * batadv_nc_nodes_seq_print_text - print the nc node information |
1813 | * @seq: seq file to print on |
1814 | * @offset: not used |
1815 | */ |
1816 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) |
1817 | { |
1818 | struct net_device *net_dev = (struct net_device *)seq->private; |
1819 | struct batadv_priv *bat_priv = netdev_priv(net_dev); |
1820 | struct batadv_hashtable *hash = bat_priv->orig_hash; |
1821 | struct batadv_hard_iface *primary_if; |
1822 | struct hlist_head *head; |
1823 | struct batadv_orig_node *orig_node; |
1824 | struct batadv_nc_node *nc_node; |
1825 | int i; |
1826 | |
1827 | primary_if = batadv_seq_print_text_primary_if_get(seq); |
1828 | if (!primary_if) |
1829 | goto out; |
1830 | |
1831 | /* Traverse list of originators */ |
1832 | for (i = 0; i < hash->size; i++) { |
1833 | head = &hash->table[i]; |
1834 | |
1835 | /* For each orig_node in this bin */ |
1836 | rcu_read_lock(); |
1837 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
1838 | /* no need to print the orig node if it does not have |
1839 | * network coding neighbors |
1840 | */ |
1841 | if (list_empty(&orig_node->in_coding_list) && |
1842 | list_empty(&orig_node->out_coding_list)) |
1843 | continue; |
1844 | |
1845 | seq_printf(seq, "Node: %pM\n", orig_node->orig); |
1846 | |
1847 | seq_puts(seq, " Ingoing: "); |
1848 | /* For each in_nc_node to this orig_node */ |
1849 | list_for_each_entry_rcu(nc_node, |
1850 | &orig_node->in_coding_list, |
1851 | list) |
1852 | seq_printf(seq, "%pM ", |
1853 | nc_node->addr); |
1854 | seq_puts(seq, "\n"); |
1855 | |
1856 | seq_puts(seq, " Outgoing: "); |
1857 | /* For out_nc_node to this orig_node */ |
1858 | list_for_each_entry_rcu(nc_node, |
1859 | &orig_node->out_coding_list, |
1860 | list) |
1861 | seq_printf(seq, "%pM ", |
1862 | nc_node->addr); |
1863 | seq_puts(seq, "\n\n"); |
1864 | } |
1865 | rcu_read_unlock(); |
1866 | } |
1867 | |
1868 | out: |
1869 | if (primary_if) |
1870 | batadv_hardif_free_ref(primary_if); |
1871 | return 0; |
1872 | } |
1873 | |
1874 | /** |
1875 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs |
1876 | * @bat_priv: the bat priv with all the soft interface information |
1877 | */ |
1878 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) |
1879 | { |
1880 | struct dentry *nc_dir, *file; |
1881 | |
1882 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); |
1883 | if (!nc_dir) |
1884 | goto out; |
1885 | |
1886 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, |
1887 | &bat_priv->nc.min_tq); |
1888 | if (!file) |
1889 | goto out; |
1890 | |
1891 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1892 | &bat_priv->nc.max_fwd_delay); |
1893 | if (!file) |
1894 | goto out; |
1895 | |
1896 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1897 | &bat_priv->nc.max_buffer_time); |
1898 | if (!file) |
1899 | goto out; |
1900 | |
1901 | return 0; |
1902 | |
1903 | out: |
1904 | return -ENOMEM; |
1905 | } |
1906 |
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