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9f6446c7 | 1 | /* Copyright (C) 2012-2015 B.A.T.M.A.N. contributors: |
d353d8d4 MH |
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 | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
d353d8d4 MH |
16 | */ |
17 | ||
d56b1705 MH |
18 | #include <linux/debugfs.h> |
19 | ||
d353d8d4 | 20 | #include "main.h" |
95332477 | 21 | #include "hash.h" |
d353d8d4 | 22 | #include "network-coding.h" |
95332477 | 23 | #include "send.h" |
d56b1705 MH |
24 | #include "originator.h" |
25 | #include "hard-interface.h" | |
2df5278b | 26 | #include "routing.h" |
d353d8d4 | 27 | |
95332477 | 28 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
612d2b4f | 29 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
95332477 | 30 | |
d353d8d4 | 31 | static void batadv_nc_worker(struct work_struct *work); |
2df5278b MH |
32 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
33 | struct batadv_hard_iface *recv_if); | |
d353d8d4 | 34 | |
6c519bad MS |
35 | /** |
36 | * batadv_nc_init - one-time initialization for network coding | |
37 | */ | |
38 | int __init batadv_nc_init(void) | |
39 | { | |
40 | int ret; | |
41 | ||
42 | /* Register our packet type */ | |
43 | ret = batadv_recv_handler_register(BATADV_CODED, | |
44 | batadv_nc_recv_coded_packet); | |
45 | ||
46 | return ret; | |
47 | } | |
48 | ||
d353d8d4 MH |
49 | /** |
50 | * batadv_nc_start_timer - initialise the nc periodic worker | |
51 | * @bat_priv: the bat priv with all the soft interface information | |
52 | */ | |
53 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
54 | { | |
55 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
56 | msecs_to_jiffies(10)); | |
57 | } | |
58 | ||
3f4841ff ML |
59 | /** |
60 | * batadv_nc_tvlv_container_update - update the network coding tvlv container | |
61 | * after network coding setting change | |
62 | * @bat_priv: the bat priv with all the soft interface information | |
63 | */ | |
64 | static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv) | |
65 | { | |
66 | char nc_mode; | |
67 | ||
68 | nc_mode = atomic_read(&bat_priv->network_coding); | |
69 | ||
70 | switch (nc_mode) { | |
71 | case 0: | |
72 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
73 | break; | |
74 | case 1: | |
75 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1, | |
76 | NULL, 0); | |
77 | break; | |
78 | } | |
79 | } | |
80 | ||
81 | /** | |
82 | * batadv_nc_status_update - update the network coding tvlv container after | |
83 | * network coding setting change | |
84 | * @net_dev: the soft interface net device | |
85 | */ | |
86 | void batadv_nc_status_update(struct net_device *net_dev) | |
87 | { | |
88 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 89 | |
3f4841ff ML |
90 | batadv_nc_tvlv_container_update(bat_priv); |
91 | } | |
92 | ||
93 | /** | |
94 | * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container | |
95 | * @bat_priv: the bat priv with all the soft interface information | |
96 | * @orig: the orig_node of the ogm | |
97 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
98 | * @tvlv_value: tvlv buffer containing the gateway data | |
99 | * @tvlv_value_len: tvlv buffer length | |
100 | */ | |
101 | static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
102 | struct batadv_orig_node *orig, | |
103 | uint8_t flags, | |
104 | void *tvlv_value, | |
105 | uint16_t tvlv_value_len) | |
106 | { | |
107 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
108 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC; | |
109 | else | |
110 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC; | |
111 | } | |
112 | ||
d353d8d4 | 113 | /** |
6c519bad | 114 | * batadv_nc_mesh_init - initialise coding hash table and start house keeping |
d353d8d4 MH |
115 | * @bat_priv: the bat priv with all the soft interface information |
116 | */ | |
6c519bad | 117 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
d353d8d4 | 118 | { |
95332477 | 119 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 120 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 121 | |
612d2b4f | 122 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
123 | return 0; |
124 | ||
125 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
126 | if (!bat_priv->nc.coding_hash) | |
127 | goto err; | |
128 | ||
129 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
130 | &batadv_nc_coding_hash_lock_class_key); | |
131 | ||
612d2b4f MH |
132 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
133 | if (!bat_priv->nc.decoding_hash) | |
134 | goto err; | |
135 | ||
f44d5407 | 136 | batadv_hash_set_lock_class(bat_priv->nc.decoding_hash, |
612d2b4f MH |
137 | &batadv_nc_decoding_hash_lock_class_key); |
138 | ||
d353d8d4 MH |
139 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
140 | batadv_nc_start_timer(bat_priv); | |
141 | ||
3f4841ff ML |
142 | batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1, |
143 | NULL, BATADV_TVLV_NC, 1, | |
144 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
145 | batadv_nc_tvlv_container_update(bat_priv); | |
d353d8d4 | 146 | return 0; |
95332477 MH |
147 | |
148 | err: | |
149 | return -ENOMEM; | |
d353d8d4 MH |
150 | } |
151 | ||
152 | /** | |
153 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables | |
154 | * @bat_priv: the bat priv with all the soft interface information | |
155 | */ | |
156 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
157 | { | |
158 | atomic_set(&bat_priv->network_coding, 1); | |
d56b1705 | 159 | bat_priv->nc.min_tq = 200; |
95332477 | 160 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 161 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
162 | } |
163 | ||
164 | /** | |
165 | * batadv_nc_init_orig - initialise the nc fields of an orig_node | |
166 | * @orig_node: the orig_node which is going to be initialised | |
167 | */ | |
168 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
169 | { | |
170 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
171 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
172 | spin_lock_init(&orig_node->in_coding_list_lock); | |
173 | spin_lock_init(&orig_node->out_coding_list_lock); | |
174 | } | |
175 | ||
176 | /** | |
177 | * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove | |
178 | * its refcount on the orig_node | |
179 | * @rcu: rcu pointer of the nc node | |
180 | */ | |
181 | static void batadv_nc_node_free_rcu(struct rcu_head *rcu) | |
182 | { | |
183 | struct batadv_nc_node *nc_node; | |
184 | ||
185 | nc_node = container_of(rcu, struct batadv_nc_node, rcu); | |
186 | batadv_orig_node_free_ref(nc_node->orig_node); | |
187 | kfree(nc_node); | |
188 | } | |
189 | ||
190 | /** | |
191 | * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly | |
192 | * frees it | |
193 | * @nc_node: the nc node to free | |
194 | */ | |
195 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) | |
196 | { | |
197 | if (atomic_dec_and_test(&nc_node->refcount)) | |
198 | call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu); | |
199 | } | |
200 | ||
95332477 MH |
201 | /** |
202 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly | |
203 | * frees it | |
204 | * @nc_path: the nc node to free | |
205 | */ | |
206 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) | |
207 | { | |
208 | if (atomic_dec_and_test(&nc_path->refcount)) | |
209 | kfree_rcu(nc_path, rcu); | |
210 | } | |
211 | ||
212 | /** | |
213 | * batadv_nc_packet_free - frees nc packet | |
214 | * @nc_packet: the nc packet to free | |
215 | */ | |
216 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) | |
217 | { | |
218 | if (nc_packet->skb) | |
219 | kfree_skb(nc_packet->skb); | |
220 | ||
221 | batadv_nc_path_free_ref(nc_packet->nc_path); | |
222 | kfree(nc_packet); | |
223 | } | |
224 | ||
d56b1705 MH |
225 | /** |
226 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged | |
227 | * @bat_priv: the bat priv with all the soft interface information | |
228 | * @nc_node: the nc node to check | |
229 | * | |
230 | * Returns true if the entry has to be purged now, false otherwise | |
231 | */ | |
232 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
233 | struct batadv_nc_node *nc_node) | |
234 | { | |
235 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
236 | return true; | |
237 | ||
238 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
239 | } | |
240 | ||
95332477 MH |
241 | /** |
242 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out | |
243 | * @bat_priv: the bat priv with all the soft interface information | |
244 | * @nc_path: the nc path to check | |
245 | * | |
246 | * Returns true if the entry has to be purged now, false otherwise | |
247 | */ | |
248 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
249 | struct batadv_nc_path *nc_path) | |
250 | { | |
251 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
252 | return true; | |
253 | ||
254 | /* purge the path when no packets has been added for 10 times the | |
255 | * max_fwd_delay time | |
256 | */ | |
257 | return batadv_has_timed_out(nc_path->last_valid, | |
258 | bat_priv->nc.max_fwd_delay * 10); | |
259 | } | |
260 | ||
612d2b4f MH |
261 | /** |
262 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out | |
263 | * @bat_priv: the bat priv with all the soft interface information | |
264 | * @nc_path: the nc path to check | |
265 | * | |
266 | * Returns true if the entry has to be purged now, false otherwise | |
267 | */ | |
268 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
269 | struct batadv_nc_path *nc_path) | |
270 | { | |
271 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
272 | return true; | |
273 | ||
274 | /* purge the path when no packets has been added for 10 times the | |
275 | * max_buffer time | |
276 | */ | |
277 | return batadv_has_timed_out(nc_path->last_valid, | |
278 | bat_priv->nc.max_buffer_time*10); | |
279 | } | |
280 | ||
d56b1705 MH |
281 | /** |
282 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale | |
283 | * entries | |
284 | * @bat_priv: the bat priv with all the soft interface information | |
285 | * @list: list of nc nodes | |
286 | * @lock: nc node list lock | |
287 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
288 | * not. This function takes the nc node as argument and has to return | |
289 | * a boolean value: true if the entry has to be deleted, false | |
290 | * otherwise | |
291 | */ | |
292 | static void | |
293 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
294 | struct list_head *list, | |
295 | spinlock_t *lock, | |
296 | bool (*to_purge)(struct batadv_priv *, | |
297 | struct batadv_nc_node *)) | |
298 | { | |
299 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
300 | ||
301 | /* For each nc_node in list */ | |
302 | spin_lock_bh(lock); | |
303 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
304 | /* if an helper function has been passed as parameter, | |
305 | * ask it if the entry has to be purged or not | |
306 | */ | |
307 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
308 | continue; | |
309 | ||
310 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
311 | "Removing nc_node %pM -> %pM\n", | |
312 | nc_node->addr, nc_node->orig_node->orig); | |
313 | list_del_rcu(&nc_node->list); | |
314 | batadv_nc_node_free_ref(nc_node); | |
315 | } | |
316 | spin_unlock_bh(lock); | |
317 | } | |
318 | ||
319 | /** | |
320 | * batadv_nc_purge_orig - purges all nc node data attached of the given | |
321 | * originator | |
322 | * @bat_priv: the bat priv with all the soft interface information | |
323 | * @orig_node: orig_node with the nc node entries to be purged | |
324 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
325 | * not. This function takes the nc node as argument and has to return | |
326 | * a boolean value: true is the entry has to be deleted, false | |
327 | * otherwise | |
328 | */ | |
329 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
330 | struct batadv_orig_node *orig_node, | |
331 | bool (*to_purge)(struct batadv_priv *, | |
332 | struct batadv_nc_node *)) | |
333 | { | |
334 | /* Check ingoing nc_node's of this orig_node */ | |
335 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
336 | &orig_node->in_coding_list_lock, | |
337 | to_purge); | |
338 | ||
339 | /* Check outgoing nc_node's of this orig_node */ | |
340 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
341 | &orig_node->out_coding_list_lock, | |
342 | to_purge); | |
343 | } | |
344 | ||
345 | /** | |
346 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they | |
347 | * have timed out nc nodes | |
348 | * @bat_priv: the bat priv with all the soft interface information | |
349 | */ | |
350 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
351 | { | |
352 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
353 | struct hlist_head *head; | |
354 | struct batadv_orig_node *orig_node; | |
355 | uint32_t i; | |
356 | ||
357 | if (!hash) | |
358 | return; | |
359 | ||
360 | /* For each orig_node */ | |
361 | for (i = 0; i < hash->size; i++) { | |
362 | head = &hash->table[i]; | |
363 | ||
364 | rcu_read_lock(); | |
365 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
366 | batadv_nc_purge_orig(bat_priv, orig_node, | |
367 | batadv_nc_to_purge_nc_node); | |
368 | rcu_read_unlock(); | |
369 | } | |
d353d8d4 MH |
370 | } |
371 | ||
95332477 MH |
372 | /** |
373 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove | |
374 | * unused ones | |
375 | * @bat_priv: the bat priv with all the soft interface information | |
376 | * @hash: hash table containing the nc paths to check | |
377 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
378 | * not. This function takes the nc node as argument and has to return | |
379 | * a boolean value: true is the entry has to be deleted, false | |
380 | * otherwise | |
381 | */ | |
382 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
383 | struct batadv_hashtable *hash, | |
384 | bool (*to_purge)(struct batadv_priv *, | |
385 | struct batadv_nc_path *)) | |
386 | { | |
387 | struct hlist_head *head; | |
388 | struct hlist_node *node_tmp; | |
389 | struct batadv_nc_path *nc_path; | |
390 | spinlock_t *lock; /* Protects lists in hash */ | |
391 | uint32_t i; | |
392 | ||
393 | for (i = 0; i < hash->size; i++) { | |
394 | head = &hash->table[i]; | |
395 | lock = &hash->list_locks[i]; | |
396 | ||
397 | /* For each nc_path in this bin */ | |
398 | spin_lock_bh(lock); | |
399 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
400 | /* if an helper function has been passed as parameter, | |
401 | * ask it if the entry has to be purged or not | |
402 | */ | |
403 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
404 | continue; | |
405 | ||
406 | /* purging an non-empty nc_path should never happen, but | |
407 | * is observed under high CPU load. Delay the purging | |
408 | * until next iteration to allow the packet_list to be | |
409 | * emptied first. | |
410 | */ | |
411 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
412 | net_ratelimited_function(printk, | |
413 | KERN_WARNING | |
414 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
415 | nc_path->prev_hop, | |
416 | nc_path->next_hop); | |
417 | continue; | |
418 | } | |
419 | ||
420 | /* nc_path is unused, so remove it */ | |
421 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
422 | "Remove nc_path %pM -> %pM\n", | |
423 | nc_path->prev_hop, nc_path->next_hop); | |
424 | hlist_del_rcu(&nc_path->hash_entry); | |
425 | batadv_nc_path_free_ref(nc_path); | |
426 | } | |
427 | spin_unlock_bh(lock); | |
428 | } | |
429 | } | |
430 | ||
431 | /** | |
432 | * batadv_nc_hash_key_gen - computes the nc_path hash key | |
433 | * @key: buffer to hold the final hash key | |
434 | * @src: source ethernet mac address going into the hash key | |
435 | * @dst: destination ethernet mac address going into the hash key | |
436 | */ | |
437 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
438 | const char *dst) | |
439 | { | |
440 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
441 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
442 | } | |
443 | ||
444 | /** | |
445 | * batadv_nc_hash_choose - compute the hash value for an nc path | |
446 | * @data: data to hash | |
447 | * @size: size of the hash table | |
448 | * | |
449 | * Returns the selected index in the hash table for the given data. | |
450 | */ | |
451 | static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) | |
452 | { | |
453 | const struct batadv_nc_path *nc_path = data; | |
454 | uint32_t hash = 0; | |
455 | ||
456 | hash = batadv_hash_bytes(hash, &nc_path->prev_hop, | |
457 | sizeof(nc_path->prev_hop)); | |
458 | hash = batadv_hash_bytes(hash, &nc_path->next_hop, | |
459 | sizeof(nc_path->next_hop)); | |
460 | ||
461 | hash += (hash << 3); | |
462 | hash ^= (hash >> 11); | |
463 | hash += (hash << 15); | |
464 | ||
465 | return hash % size; | |
466 | } | |
467 | ||
468 | /** | |
469 | * batadv_nc_hash_compare - comparing function used in the network coding hash | |
470 | * tables | |
471 | * @node: node in the local table | |
472 | * @data2: second object to compare the node to | |
473 | * | |
474 | * Returns 1 if the two entry are the same, 0 otherwise | |
475 | */ | |
476 | static int batadv_nc_hash_compare(const struct hlist_node *node, | |
477 | const void *data2) | |
478 | { | |
479 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
480 | ||
481 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
482 | nc_path2 = data2; | |
483 | ||
484 | /* Return 1 if the two keys are identical */ | |
485 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, | |
486 | sizeof(nc_path1->prev_hop)) != 0) | |
487 | return 0; | |
488 | ||
489 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, | |
490 | sizeof(nc_path1->next_hop)) != 0) | |
491 | return 0; | |
492 | ||
493 | return 1; | |
494 | } | |
495 | ||
496 | /** | |
497 | * batadv_nc_hash_find - search for an existing nc path and return it | |
498 | * @hash: hash table containing the nc path | |
499 | * @data: search key | |
500 | * | |
501 | * Returns the nc_path if found, NULL otherwise. | |
502 | */ | |
503 | static struct batadv_nc_path * | |
504 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
505 | void *data) | |
506 | { | |
507 | struct hlist_head *head; | |
508 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
509 | int index; | |
510 | ||
511 | if (!hash) | |
512 | return NULL; | |
513 | ||
514 | index = batadv_nc_hash_choose(data, hash->size); | |
515 | head = &hash->table[index]; | |
516 | ||
517 | rcu_read_lock(); | |
518 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
519 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
520 | continue; | |
521 | ||
522 | if (!atomic_inc_not_zero(&nc_path->refcount)) | |
523 | continue; | |
524 | ||
525 | nc_path_tmp = nc_path; | |
526 | break; | |
527 | } | |
528 | rcu_read_unlock(); | |
529 | ||
530 | return nc_path_tmp; | |
531 | } | |
532 | ||
533 | /** | |
534 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct | |
535 | * @nc_packet: the nc packet to send | |
536 | */ | |
537 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
538 | { | |
539 | batadv_send_skb_packet(nc_packet->skb, | |
540 | nc_packet->neigh_node->if_incoming, | |
541 | nc_packet->nc_path->next_hop); | |
542 | nc_packet->skb = NULL; | |
543 | batadv_nc_packet_free(nc_packet); | |
544 | } | |
545 | ||
612d2b4f MH |
546 | /** |
547 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. | |
548 | * @bat_priv: the bat priv with all the soft interface information | |
549 | * @nc_path: the nc path the packet belongs to | |
550 | * @nc_packet: the nc packet to be checked | |
551 | * | |
552 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
553 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
554 | * queue. Has to be called with the appropriate locks. | |
555 | * | |
556 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
557 | * yet and true otherwise. | |
558 | */ | |
559 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
560 | struct batadv_nc_path *nc_path, | |
561 | struct batadv_nc_packet *nc_packet) | |
562 | { | |
563 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
564 | bool res = false; | |
565 | ||
566 | /* Packets are added to tail, so the remaining packets did not time | |
567 | * out and we can stop processing the current queue | |
568 | */ | |
569 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
570 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
571 | goto out; | |
572 | ||
573 | /* purge nc packet */ | |
574 | list_del(&nc_packet->list); | |
575 | batadv_nc_packet_free(nc_packet); | |
576 | ||
577 | res = true; | |
578 | ||
579 | out: | |
580 | return res; | |
581 | } | |
582 | ||
95332477 MH |
583 | /** |
584 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. | |
585 | * @bat_priv: the bat priv with all the soft interface information | |
586 | * @nc_path: the nc path the packet belongs to | |
587 | * @nc_packet: the nc packet to be checked | |
588 | * | |
589 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
590 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
591 | * queue. Has to be called with the appropriate locks. | |
592 | * | |
593 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
594 | * yet and true otherwise. | |
595 | */ | |
596 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
597 | struct batadv_nc_path *nc_path, | |
598 | struct batadv_nc_packet *nc_packet) | |
599 | { | |
600 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
601 | ||
602 | /* Packets are added to tail, so the remaining packets did not time | |
603 | * out and we can stop processing the current queue | |
604 | */ | |
605 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
606 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
607 | return false; | |
608 | ||
609 | /* Send packet */ | |
610 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
611 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
612 | nc_packet->skb->len + ETH_HLEN); | |
613 | list_del(&nc_packet->list); | |
614 | batadv_nc_send_packet(nc_packet); | |
615 | ||
616 | return true; | |
617 | } | |
618 | ||
619 | /** | |
620 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out | |
621 | * nc packets | |
622 | * @bat_priv: the bat priv with all the soft interface information | |
623 | * @hash: to be processed hash table | |
624 | * @process_fn: Function called to process given nc packet. Should return true | |
625 | * to encourage this function to proceed with the next packet. | |
626 | * Otherwise the rest of the current queue is skipped. | |
627 | */ | |
628 | static void | |
629 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
630 | struct batadv_hashtable *hash, | |
631 | bool (*process_fn)(struct batadv_priv *, | |
632 | struct batadv_nc_path *, | |
633 | struct batadv_nc_packet *)) | |
634 | { | |
635 | struct hlist_head *head; | |
636 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
637 | struct batadv_nc_path *nc_path; | |
638 | bool ret; | |
639 | int i; | |
640 | ||
641 | if (!hash) | |
642 | return; | |
643 | ||
644 | /* Loop hash table bins */ | |
645 | for (i = 0; i < hash->size; i++) { | |
646 | head = &hash->table[i]; | |
647 | ||
648 | /* Loop coding paths */ | |
649 | rcu_read_lock(); | |
650 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
651 | /* Loop packets */ | |
652 | spin_lock_bh(&nc_path->packet_list_lock); | |
653 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
654 | &nc_path->packet_list, list) { | |
655 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
656 | if (!ret) | |
657 | break; | |
658 | } | |
659 | spin_unlock_bh(&nc_path->packet_list_lock); | |
660 | } | |
661 | rcu_read_unlock(); | |
662 | } | |
663 | } | |
664 | ||
d353d8d4 MH |
665 | /** |
666 | * batadv_nc_worker - periodic task for house keeping related to network coding | |
667 | * @work: kernel work struct | |
668 | */ | |
669 | static void batadv_nc_worker(struct work_struct *work) | |
670 | { | |
671 | struct delayed_work *delayed_work; | |
672 | struct batadv_priv_nc *priv_nc; | |
673 | struct batadv_priv *bat_priv; | |
95332477 | 674 | unsigned long timeout; |
d353d8d4 MH |
675 | |
676 | delayed_work = container_of(work, struct delayed_work, work); | |
677 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); | |
678 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
679 | ||
d56b1705 | 680 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
681 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
682 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
683 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
684 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
685 | |
686 | timeout = bat_priv->nc.max_fwd_delay; | |
687 | ||
688 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
689 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
690 | batadv_nc_fwd_flush); | |
691 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
692 | } | |
d56b1705 | 693 | |
612d2b4f MH |
694 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
695 | bat_priv->nc.max_buffer_time)) { | |
696 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
697 | batadv_nc_sniffed_purge); | |
698 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
699 | } | |
700 | ||
d353d8d4 MH |
701 | /* Schedule a new check */ |
702 | batadv_nc_start_timer(bat_priv); | |
703 | } | |
704 | ||
d56b1705 MH |
705 | /** |
706 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for | |
707 | * coding or not | |
708 | * @bat_priv: the bat priv with all the soft interface information | |
709 | * @orig_node: neighboring orig node which may be used as nc candidate | |
710 | * @ogm_packet: incoming ogm packet also used for the checks | |
711 | * | |
712 | * Returns true if: | |
713 | * 1) The OGM must have the most recent sequence number. | |
714 | * 2) The TTL must be decremented by one and only one. | |
715 | * 3) The OGM must be received from the first hop from orig_node. | |
716 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
717 | */ | |
718 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
719 | struct batadv_orig_node *orig_node, | |
720 | struct batadv_ogm_packet *ogm_packet) | |
721 | { | |
7351a482 SW |
722 | struct batadv_orig_ifinfo *orig_ifinfo; |
723 | uint32_t last_real_seqno; | |
724 | uint8_t last_ttl; | |
725 | ||
726 | orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT); | |
727 | if (!orig_ifinfo) | |
d56b1705 | 728 | return false; |
7351a482 SW |
729 | |
730 | last_ttl = orig_ifinfo->last_ttl; | |
731 | last_real_seqno = orig_ifinfo->last_real_seqno; | |
732 | batadv_orig_ifinfo_free_ref(orig_ifinfo); | |
733 | ||
734 | if (last_real_seqno != ntohl(ogm_packet->seqno)) | |
735 | return false; | |
736 | if (last_ttl != ogm_packet->ttl + 1) | |
d56b1705 MH |
737 | return false; |
738 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
739 | return false; | |
740 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
741 | return false; | |
742 | ||
743 | return true; | |
744 | } | |
745 | ||
746 | /** | |
747 | * batadv_nc_find_nc_node - search for an existing nc node and return it | |
748 | * @orig_node: orig node originating the ogm packet | |
749 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
750 | * (can be equal to orig_node) | |
751 | * @in_coding: traverse incoming or outgoing network coding list | |
752 | * | |
753 | * Returns the nc_node if found, NULL otherwise. | |
754 | */ | |
755 | static struct batadv_nc_node | |
756 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
757 | struct batadv_orig_node *orig_neigh_node, | |
758 | bool in_coding) | |
759 | { | |
760 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
761 | struct list_head *list; | |
762 | ||
763 | if (in_coding) | |
764 | list = &orig_neigh_node->in_coding_list; | |
765 | else | |
766 | list = &orig_neigh_node->out_coding_list; | |
767 | ||
768 | /* Traverse list of nc_nodes to orig_node */ | |
769 | rcu_read_lock(); | |
770 | list_for_each_entry_rcu(nc_node, list, list) { | |
771 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
772 | continue; | |
773 | ||
774 | if (!atomic_inc_not_zero(&nc_node->refcount)) | |
775 | continue; | |
776 | ||
777 | /* Found a match */ | |
778 | nc_node_out = nc_node; | |
779 | break; | |
780 | } | |
781 | rcu_read_unlock(); | |
782 | ||
783 | return nc_node_out; | |
784 | } | |
785 | ||
786 | /** | |
787 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was | |
788 | * not found | |
789 | * @bat_priv: the bat priv with all the soft interface information | |
790 | * @orig_node: orig node originating the ogm packet | |
791 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
792 | * (can be equal to orig_node) | |
793 | * @in_coding: traverse incoming or outgoing network coding list | |
794 | * | |
795 | * Returns the nc_node if found or created, NULL in case of an error. | |
796 | */ | |
797 | static struct batadv_nc_node | |
798 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
799 | struct batadv_orig_node *orig_node, | |
800 | struct batadv_orig_node *orig_neigh_node, | |
801 | bool in_coding) | |
802 | { | |
803 | struct batadv_nc_node *nc_node; | |
804 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
805 | struct list_head *list; | |
806 | ||
807 | /* Check if nc_node is already added */ | |
808 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
809 | ||
810 | /* Node found */ | |
811 | if (nc_node) | |
812 | return nc_node; | |
813 | ||
814 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
815 | if (!nc_node) | |
816 | return NULL; | |
817 | ||
818 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) | |
819 | goto free; | |
820 | ||
821 | /* Initialize nc_node */ | |
822 | INIT_LIST_HEAD(&nc_node->list); | |
8fdd0153 | 823 | ether_addr_copy(nc_node->addr, orig_node->orig); |
d56b1705 MH |
824 | nc_node->orig_node = orig_neigh_node; |
825 | atomic_set(&nc_node->refcount, 2); | |
826 | ||
827 | /* Select ingoing or outgoing coding node */ | |
828 | if (in_coding) { | |
829 | lock = &orig_neigh_node->in_coding_list_lock; | |
830 | list = &orig_neigh_node->in_coding_list; | |
831 | } else { | |
832 | lock = &orig_neigh_node->out_coding_list_lock; | |
833 | list = &orig_neigh_node->out_coding_list; | |
834 | } | |
835 | ||
836 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", | |
837 | nc_node->addr, nc_node->orig_node->orig); | |
838 | ||
839 | /* Add nc_node to orig_node */ | |
840 | spin_lock_bh(lock); | |
841 | list_add_tail_rcu(&nc_node->list, list); | |
842 | spin_unlock_bh(lock); | |
843 | ||
844 | return nc_node; | |
845 | ||
846 | free: | |
847 | kfree(nc_node); | |
848 | return NULL; | |
849 | } | |
850 | ||
851 | /** | |
852 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs | |
853 | * (best called on incoming OGMs) | |
854 | * @bat_priv: the bat priv with all the soft interface information | |
855 | * @orig_node: orig node originating the ogm packet | |
856 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
857 | * (can be equal to orig_node) | |
858 | * @ogm_packet: incoming ogm packet | |
859 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
860 | */ | |
861 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
862 | struct batadv_orig_node *orig_node, | |
863 | struct batadv_orig_node *orig_neigh_node, | |
864 | struct batadv_ogm_packet *ogm_packet, | |
865 | int is_single_hop_neigh) | |
866 | { | |
867 | struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL; | |
868 | ||
869 | /* Check if network coding is enabled */ | |
870 | if (!atomic_read(&bat_priv->network_coding)) | |
871 | goto out; | |
872 | ||
3f4841ff ML |
873 | /* check if orig node is network coding enabled */ |
874 | if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC)) | |
875 | goto out; | |
876 | ||
d56b1705 MH |
877 | /* accept ogms from 'good' neighbors and single hop neighbors */ |
878 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
879 | !is_single_hop_neigh) | |
880 | goto out; | |
881 | ||
882 | /* Add orig_node as in_nc_node on hop */ | |
883 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
884 | orig_neigh_node, true); | |
885 | if (!in_nc_node) | |
886 | goto out; | |
887 | ||
888 | in_nc_node->last_seen = jiffies; | |
889 | ||
890 | /* Add hop as out_nc_node on orig_node */ | |
891 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
892 | orig_node, false); | |
893 | if (!out_nc_node) | |
894 | goto out; | |
895 | ||
896 | out_nc_node->last_seen = jiffies; | |
897 | ||
898 | out: | |
899 | if (in_nc_node) | |
900 | batadv_nc_node_free_ref(in_nc_node); | |
901 | if (out_nc_node) | |
902 | batadv_nc_node_free_ref(out_nc_node); | |
903 | } | |
904 | ||
95332477 MH |
905 | /** |
906 | * batadv_nc_get_path - get existing nc_path or allocate a new one | |
907 | * @bat_priv: the bat priv with all the soft interface information | |
908 | * @hash: hash table containing the nc path | |
909 | * @src: ethernet source address - first half of the nc path search key | |
910 | * @dst: ethernet destination address - second half of the nc path search key | |
911 | * | |
912 | * Returns pointer to nc_path if the path was found or created, returns NULL | |
913 | * on error. | |
914 | */ | |
915 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
916 | struct batadv_hashtable *hash, | |
917 | uint8_t *src, | |
918 | uint8_t *dst) | |
919 | { | |
920 | int hash_added; | |
921 | struct batadv_nc_path *nc_path, nc_path_key; | |
922 | ||
923 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
924 | ||
925 | /* Search for existing nc_path */ | |
926 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
927 | ||
928 | if (nc_path) { | |
929 | /* Set timestamp to delay removal of nc_path */ | |
930 | nc_path->last_valid = jiffies; | |
931 | return nc_path; | |
932 | } | |
933 | ||
934 | /* No existing nc_path was found; create a new */ | |
935 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
936 | ||
937 | if (!nc_path) | |
938 | return NULL; | |
939 | ||
940 | /* Initialize nc_path */ | |
941 | INIT_LIST_HEAD(&nc_path->packet_list); | |
942 | spin_lock_init(&nc_path->packet_list_lock); | |
943 | atomic_set(&nc_path->refcount, 2); | |
944 | nc_path->last_valid = jiffies; | |
8fdd0153 AQ |
945 | ether_addr_copy(nc_path->next_hop, dst); |
946 | ether_addr_copy(nc_path->prev_hop, src); | |
95332477 MH |
947 | |
948 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
949 | nc_path->prev_hop, | |
950 | nc_path->next_hop); | |
951 | ||
952 | /* Add nc_path to hash table */ | |
953 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, | |
954 | batadv_nc_hash_choose, &nc_path_key, | |
955 | &nc_path->hash_entry); | |
956 | ||
957 | if (hash_added < 0) { | |
958 | kfree(nc_path); | |
959 | return NULL; | |
960 | } | |
961 | ||
962 | return nc_path; | |
963 | } | |
964 | ||
3c12de9a MH |
965 | /** |
966 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair | |
967 | * selection of a receiver with slightly lower TQ than the other | |
968 | * @tq: to be weighted tq value | |
969 | */ | |
970 | static uint8_t batadv_nc_random_weight_tq(uint8_t tq) | |
971 | { | |
972 | uint8_t rand_val, rand_tq; | |
973 | ||
974 | get_random_bytes(&rand_val, sizeof(rand_val)); | |
975 | ||
976 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ | |
977 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); | |
978 | ||
979 | /* normalize the randomized packet loss */ | |
980 | rand_tq /= BATADV_TQ_MAX_VALUE; | |
981 | ||
982 | /* convert to (randomized) estimated tq again */ | |
983 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
984 | } | |
985 | ||
986 | /** | |
987 | * batadv_nc_memxor - XOR destination with source | |
988 | * @dst: byte array to XOR into | |
989 | * @src: byte array to XOR from | |
990 | * @len: length of destination array | |
991 | */ | |
992 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
993 | { | |
994 | unsigned int i; | |
995 | ||
996 | for (i = 0; i < len; ++i) | |
997 | dst[i] ^= src[i]; | |
998 | } | |
999 | ||
1000 | /** | |
1001 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet | |
1002 | * into a coded_packet and send it | |
1003 | * @bat_priv: the bat priv with all the soft interface information | |
1004 | * @skb: data skb to forward | |
1005 | * @ethhdr: pointer to the ethernet header inside the skb | |
1006 | * @nc_packet: structure containing the packet to the skb can be coded with | |
1007 | * @neigh_node: next hop to forward packet to | |
1008 | * | |
1009 | * Returns true if both packets are consumed, false otherwise. | |
1010 | */ | |
1011 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
1012 | struct sk_buff *skb, | |
1013 | struct ethhdr *ethhdr, | |
1014 | struct batadv_nc_packet *nc_packet, | |
1015 | struct batadv_neigh_node *neigh_node) | |
1016 | { | |
0538f759 | 1017 | uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp; |
3c12de9a MH |
1018 | struct sk_buff *skb_dest, *skb_src; |
1019 | struct batadv_unicast_packet *packet1; | |
1020 | struct batadv_unicast_packet *packet2; | |
1021 | struct batadv_coded_packet *coded_packet; | |
1022 | struct batadv_neigh_node *neigh_tmp, *router_neigh; | |
1023 | struct batadv_neigh_node *router_coding = NULL; | |
89652331 SW |
1024 | struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL; |
1025 | struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL; | |
3c12de9a MH |
1026 | uint8_t *first_source, *first_dest, *second_source, *second_dest; |
1027 | __be32 packet_id1, packet_id2; | |
1028 | size_t count; | |
1029 | bool res = false; | |
1030 | int coding_len; | |
1031 | int unicast_size = sizeof(*packet1); | |
1032 | int coded_size = sizeof(*coded_packet); | |
1033 | int header_add = coded_size - unicast_size; | |
1034 | ||
7351a482 SW |
1035 | /* TODO: do we need to consider the outgoing interface for |
1036 | * coded packets? | |
1037 | */ | |
1038 | router_neigh = batadv_orig_router_get(neigh_node->orig_node, | |
1039 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1040 | if (!router_neigh) |
1041 | goto out; | |
1042 | ||
89652331 SW |
1043 | router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh, |
1044 | BATADV_IF_DEFAULT); | |
1045 | if (!router_neigh_ifinfo) | |
1046 | goto out; | |
1047 | ||
3c12de9a | 1048 | neigh_tmp = nc_packet->neigh_node; |
7351a482 SW |
1049 | router_coding = batadv_orig_router_get(neigh_tmp->orig_node, |
1050 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1051 | if (!router_coding) |
1052 | goto out; | |
1053 | ||
89652331 SW |
1054 | router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding, |
1055 | BATADV_IF_DEFAULT); | |
1056 | if (!router_coding_ifinfo) | |
1057 | goto out; | |
1058 | ||
1059 | tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg; | |
1060 | tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp); | |
1061 | tq_tmp = router_coding_ifinfo->bat_iv.tq_avg; | |
1062 | tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp); | |
3c12de9a MH |
1063 | |
1064 | /* Select one destination for the MAC-header dst-field based on | |
1065 | * weighted TQ-values. | |
1066 | */ | |
1067 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
1068 | /* Destination from nc_packet is selected for MAC-header */ | |
1069 | first_dest = nc_packet->nc_path->next_hop; | |
1070 | first_source = nc_packet->nc_path->prev_hop; | |
1071 | second_dest = neigh_node->addr; | |
1072 | second_source = ethhdr->h_source; | |
1073 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1074 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
1075 | packet_id1 = nc_packet->packet_id; | |
1076 | packet_id2 = batadv_skb_crc32(skb, | |
1077 | skb->data + sizeof(*packet2)); | |
1078 | } else { | |
1079 | /* Destination for skb is selected for MAC-header */ | |
1080 | first_dest = neigh_node->addr; | |
1081 | first_source = ethhdr->h_source; | |
1082 | second_dest = nc_packet->nc_path->next_hop; | |
1083 | second_source = nc_packet->nc_path->prev_hop; | |
1084 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
1085 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1086 | packet_id1 = batadv_skb_crc32(skb, | |
1087 | skb->data + sizeof(*packet1)); | |
1088 | packet_id2 = nc_packet->packet_id; | |
1089 | } | |
1090 | ||
1091 | /* Instead of zero padding the smallest data buffer, we | |
1092 | * code into the largest. | |
1093 | */ | |
1094 | if (skb->len <= nc_packet->skb->len) { | |
1095 | skb_dest = nc_packet->skb; | |
1096 | skb_src = skb; | |
1097 | } else { | |
1098 | skb_dest = skb; | |
1099 | skb_src = nc_packet->skb; | |
1100 | } | |
1101 | ||
1102 | /* coding_len is used when decoding the packet shorter packet */ | |
1103 | coding_len = skb_src->len - unicast_size; | |
1104 | ||
1105 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1106 | goto out; | |
1107 | ||
1108 | skb_push(skb_dest, header_add); | |
1109 | ||
1110 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1111 | skb_reset_mac_header(skb_dest); | |
1112 | ||
a40d9b07 SW |
1113 | coded_packet->packet_type = BATADV_CODED; |
1114 | coded_packet->version = BATADV_COMPAT_VERSION; | |
1115 | coded_packet->ttl = packet1->ttl; | |
3c12de9a MH |
1116 | |
1117 | /* Info about first unicast packet */ | |
8fdd0153 AQ |
1118 | ether_addr_copy(coded_packet->first_source, first_source); |
1119 | ether_addr_copy(coded_packet->first_orig_dest, packet1->dest); | |
3c12de9a MH |
1120 | coded_packet->first_crc = packet_id1; |
1121 | coded_packet->first_ttvn = packet1->ttvn; | |
1122 | ||
1123 | /* Info about second unicast packet */ | |
8fdd0153 AQ |
1124 | ether_addr_copy(coded_packet->second_dest, second_dest); |
1125 | ether_addr_copy(coded_packet->second_source, second_source); | |
1126 | ether_addr_copy(coded_packet->second_orig_dest, packet2->dest); | |
3c12de9a | 1127 | coded_packet->second_crc = packet_id2; |
a40d9b07 | 1128 | coded_packet->second_ttl = packet2->ttl; |
3c12de9a MH |
1129 | coded_packet->second_ttvn = packet2->ttvn; |
1130 | coded_packet->coded_len = htons(coding_len); | |
1131 | ||
1132 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1133 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1134 | skb_src->data + unicast_size, coding_len); | |
1135 | ||
1136 | /* Update counters accordingly */ | |
1137 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1138 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1139 | /* Both packets are recoded */ | |
1140 | count = skb_src->len + ETH_HLEN; | |
1141 | count += skb_dest->len + ETH_HLEN; | |
1142 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1143 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1144 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1145 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1146 | /* Both packets are newly coded */ | |
1147 | count = skb_src->len + ETH_HLEN; | |
1148 | count += skb_dest->len + ETH_HLEN; | |
1149 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1150 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1151 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1152 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1153 | /* skb_src recoded and skb_dest is newly coded */ | |
1154 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1155 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1156 | skb_src->len + ETH_HLEN); | |
1157 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1158 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1159 | skb_dest->len + ETH_HLEN); | |
1160 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1161 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1162 | /* skb_src is newly coded and skb_dest is recoded */ | |
1163 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1164 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1165 | skb_src->len + ETH_HLEN); | |
1166 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1167 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1168 | skb_dest->len + ETH_HLEN); | |
1169 | } | |
1170 | ||
1171 | /* skb_src is now coded into skb_dest, so free it */ | |
1172 | kfree_skb(skb_src); | |
1173 | ||
1174 | /* avoid duplicate free of skb from nc_packet */ | |
1175 | nc_packet->skb = NULL; | |
1176 | batadv_nc_packet_free(nc_packet); | |
1177 | ||
1178 | /* Send the coded packet and return true */ | |
1179 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); | |
1180 | res = true; | |
1181 | out: | |
1182 | if (router_neigh) | |
1183 | batadv_neigh_node_free_ref(router_neigh); | |
1184 | if (router_coding) | |
1185 | batadv_neigh_node_free_ref(router_coding); | |
89652331 SW |
1186 | if (router_neigh_ifinfo) |
1187 | batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo); | |
1188 | if (router_coding_ifinfo) | |
1189 | batadv_neigh_ifinfo_free_ref(router_coding_ifinfo); | |
3c12de9a MH |
1190 | return res; |
1191 | } | |
1192 | ||
1193 | /** | |
1194 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. | |
1195 | * @skb: data skb to forward | |
1196 | * @dst: destination mac address of the other skb to code with | |
1197 | * @src: source mac address of skb | |
1198 | * | |
1199 | * Whenever we network code a packet we have to check whether we received it in | |
1200 | * a network coded form. If so, we may not be able to use it for coding because | |
1201 | * some neighbors may also have received (overheard) the packet in the network | |
1202 | * coded form without being able to decode it. It is hard to know which of the | |
1203 | * neighboring nodes was able to decode the packet, therefore we can only | |
1204 | * re-code the packet if the source of the previous encoded packet is involved. | |
1205 | * Since the source encoded the packet we can be certain it has all necessary | |
1206 | * decode information. | |
1207 | * | |
1208 | * Returns true if coding of a decoded packet is allowed. | |
1209 | */ | |
1210 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, | |
1211 | uint8_t *dst, uint8_t *src) | |
1212 | { | |
1213 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1214 | return false; | |
24820df1 | 1215 | return true; |
3c12de9a MH |
1216 | } |
1217 | ||
1218 | /** | |
1219 | * batadv_nc_path_search - Find the coding path matching in_nc_node and | |
1220 | * out_nc_node to retrieve a buffered packet that can be used for coding. | |
1221 | * @bat_priv: the bat priv with all the soft interface information | |
1222 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1223 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1224 | * @skb: data skb to forward | |
1225 | * @eth_dst: next hop mac address of skb | |
1226 | * | |
1227 | * Returns true if coding of a decoded skb is allowed. | |
1228 | */ | |
1229 | static struct batadv_nc_packet * | |
1230 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1231 | struct batadv_nc_node *in_nc_node, | |
1232 | struct batadv_nc_node *out_nc_node, | |
1233 | struct sk_buff *skb, | |
1234 | uint8_t *eth_dst) | |
1235 | { | |
1236 | struct batadv_nc_path *nc_path, nc_path_key; | |
1237 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1238 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1239 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1240 | int idx; | |
1241 | ||
1242 | if (!hash) | |
1243 | return NULL; | |
1244 | ||
1245 | /* Create almost path key */ | |
1246 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1247 | out_nc_node->addr); | |
1248 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1249 | ||
1250 | /* Check for coding opportunities in this nc_path */ | |
1251 | rcu_read_lock(); | |
1252 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1253 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1254 | continue; | |
1255 | ||
1256 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1257 | continue; | |
1258 | ||
1259 | spin_lock_bh(&nc_path->packet_list_lock); | |
1260 | if (list_empty(&nc_path->packet_list)) { | |
1261 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1262 | continue; | |
1263 | } | |
1264 | ||
1265 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1266 | &nc_path->packet_list, list) { | |
1267 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1268 | eth_dst, | |
1269 | in_nc_node->addr)) | |
1270 | continue; | |
1271 | ||
1272 | /* Coding opportunity is found! */ | |
1273 | list_del(&nc_packet->list); | |
1274 | nc_packet_out = nc_packet; | |
1275 | break; | |
1276 | } | |
1277 | ||
1278 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1279 | break; | |
1280 | } | |
1281 | rcu_read_unlock(); | |
1282 | ||
1283 | return nc_packet_out; | |
1284 | } | |
1285 | ||
1286 | /** | |
1287 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the | |
1288 | * skb's sender (may be equal to the originator). | |
1289 | * @bat_priv: the bat priv with all the soft interface information | |
1290 | * @skb: data skb to forward | |
1291 | * @eth_dst: next hop mac address of skb | |
1292 | * @eth_src: source mac address of skb | |
1293 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1294 | * | |
1295 | * Returns an nc packet if a suitable coding packet was found, NULL otherwise. | |
1296 | */ | |
1297 | static struct batadv_nc_packet * | |
1298 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1299 | struct sk_buff *skb, | |
1300 | uint8_t *eth_dst, | |
1301 | uint8_t *eth_src, | |
1302 | struct batadv_nc_node *in_nc_node) | |
1303 | { | |
1304 | struct batadv_orig_node *orig_node; | |
1305 | struct batadv_nc_node *out_nc_node; | |
1306 | struct batadv_nc_packet *nc_packet = NULL; | |
1307 | ||
1308 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1309 | if (!orig_node) | |
1310 | return NULL; | |
1311 | ||
1312 | rcu_read_lock(); | |
1313 | list_for_each_entry_rcu(out_nc_node, | |
1314 | &orig_node->out_coding_list, list) { | |
1315 | /* Check if the skb is decoded and if recoding is possible */ | |
1316 | if (!batadv_nc_skb_coding_possible(skb, | |
1317 | out_nc_node->addr, eth_src)) | |
1318 | continue; | |
1319 | ||
1320 | /* Search for an opportunity in this nc_path */ | |
1321 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1322 | out_nc_node, skb, eth_dst); | |
1323 | if (nc_packet) | |
1324 | break; | |
1325 | } | |
1326 | rcu_read_unlock(); | |
1327 | ||
1328 | batadv_orig_node_free_ref(orig_node); | |
1329 | return nc_packet; | |
1330 | } | |
1331 | ||
612d2b4f MH |
1332 | /** |
1333 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the | |
1334 | * unicast skb before it is stored for use in later decoding | |
1335 | * @bat_priv: the bat priv with all the soft interface information | |
1336 | * @skb: data skb to store | |
1337 | * @eth_dst_new: new destination mac address of skb | |
1338 | */ | |
1339 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1340 | struct sk_buff *skb, | |
1341 | uint8_t *eth_dst_new) | |
1342 | { | |
1343 | struct ethhdr *ethhdr; | |
1344 | ||
1345 | /* Copy skb header to change the mac header */ | |
bad93e9d | 1346 | skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
612d2b4f MH |
1347 | if (!skb) |
1348 | return; | |
1349 | ||
1350 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1351 | ethhdr = eth_hdr(skb); |
8fdd0153 AQ |
1352 | ether_addr_copy(ethhdr->h_source, ethhdr->h_dest); |
1353 | ether_addr_copy(ethhdr->h_dest, eth_dst_new); | |
612d2b4f MH |
1354 | |
1355 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1356 | skb_push(skb, ETH_HLEN); | |
1357 | ||
1358 | /* Add the packet to the decoding packet pool */ | |
1359 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1360 | ||
1361 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1362 | * our ref | |
1363 | */ | |
1364 | kfree_skb(skb); | |
1365 | } | |
1366 | ||
3c12de9a MH |
1367 | /** |
1368 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. | |
1369 | * @skb: data skb to forward | |
1370 | * @neigh_node: next hop to forward packet to | |
1371 | * @ethhdr: pointer to the ethernet header inside the skb | |
1372 | * | |
1373 | * Loops through list of neighboring nodes the next hop has a good connection to | |
1374 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our | |
1375 | * next hop that potentially sent a packet which our next hop also received | |
1376 | * (overheard) and has stored for later decoding. | |
1377 | * | |
1378 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1379 | */ | |
1380 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1381 | struct batadv_neigh_node *neigh_node, | |
1382 | struct ethhdr *ethhdr) | |
1383 | { | |
1384 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1385 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1386 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1387 | struct batadv_nc_node *nc_node; | |
1388 | struct batadv_nc_packet *nc_packet = NULL; | |
1389 | ||
1390 | rcu_read_lock(); | |
1391 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1392 | /* Search for coding opportunity with this in_nc_node */ | |
1393 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1394 | neigh_node->addr, | |
1395 | ethhdr->h_source, nc_node); | |
1396 | ||
1397 | /* Opportunity was found, so stop searching */ | |
1398 | if (nc_packet) | |
1399 | break; | |
1400 | } | |
1401 | rcu_read_unlock(); | |
1402 | ||
1403 | if (!nc_packet) | |
1404 | return false; | |
1405 | ||
612d2b4f MH |
1406 | /* Save packets for later decoding */ |
1407 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1408 | neigh_node->addr); | |
1409 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1410 | nc_packet->neigh_node->addr); | |
1411 | ||
3c12de9a MH |
1412 | /* Code and send packets */ |
1413 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1414 | neigh_node)) | |
1415 | return true; | |
1416 | ||
1417 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1418 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1419 | * by the calling function. | |
1420 | */ | |
1421 | batadv_nc_send_packet(nc_packet); | |
1422 | return false; | |
1423 | } | |
1424 | ||
95332477 MH |
1425 | /** |
1426 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding | |
1427 | * @skb: skb to add to path | |
1428 | * @nc_path: path to add skb to | |
1429 | * @neigh_node: next hop to forward packet to | |
1430 | * @packet_id: checksum to identify packet | |
1431 | * | |
1432 | * Returns true if the packet was buffered or false in case of an error. | |
1433 | */ | |
1434 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1435 | struct batadv_nc_path *nc_path, | |
1436 | struct batadv_neigh_node *neigh_node, | |
1437 | __be32 packet_id) | |
1438 | { | |
1439 | struct batadv_nc_packet *nc_packet; | |
1440 | ||
1441 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1442 | if (!nc_packet) | |
1443 | return false; | |
1444 | ||
1445 | /* Initialize nc_packet */ | |
1446 | nc_packet->timestamp = jiffies; | |
1447 | nc_packet->packet_id = packet_id; | |
1448 | nc_packet->skb = skb; | |
1449 | nc_packet->neigh_node = neigh_node; | |
1450 | nc_packet->nc_path = nc_path; | |
1451 | ||
1452 | /* Add coding packet to list */ | |
1453 | spin_lock_bh(&nc_path->packet_list_lock); | |
1454 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1455 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1456 | ||
1457 | return true; | |
1458 | } | |
1459 | ||
1460 | /** | |
1461 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet | |
1462 | * buffer | |
1463 | * @skb: data skb to forward | |
1464 | * @neigh_node: next hop to forward packet to | |
95332477 MH |
1465 | * |
1466 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1467 | */ | |
1468 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
e91ecfc6 | 1469 | struct batadv_neigh_node *neigh_node) |
95332477 MH |
1470 | { |
1471 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1472 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1473 | struct batadv_unicast_packet *packet; | |
1474 | struct batadv_nc_path *nc_path; | |
e91ecfc6 | 1475 | struct ethhdr *ethhdr = eth_hdr(skb); |
95332477 MH |
1476 | __be32 packet_id; |
1477 | u8 *payload; | |
1478 | ||
1479 | /* Check if network coding is enabled */ | |
1480 | if (!atomic_read(&bat_priv->network_coding)) | |
1481 | goto out; | |
1482 | ||
1483 | /* We only handle unicast packets */ | |
1484 | payload = skb_network_header(skb); | |
1485 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1486 | if (packet->packet_type != BATADV_UNICAST) |
95332477 MH |
1487 | goto out; |
1488 | ||
3c12de9a MH |
1489 | /* Try to find a coding opportunity and send the skb if one is found */ |
1490 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1491 | return true; | |
1492 | ||
95332477 MH |
1493 | /* Find or create a nc_path for this src-dst pair */ |
1494 | nc_path = batadv_nc_get_path(bat_priv, | |
1495 | bat_priv->nc.coding_hash, | |
1496 | ethhdr->h_source, | |
1497 | neigh_node->addr); | |
1498 | ||
1499 | if (!nc_path) | |
1500 | goto out; | |
1501 | ||
1502 | /* Add skb to nc_path */ | |
1503 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1504 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1505 | goto free_nc_path; | |
1506 | ||
1507 | /* Packet is consumed */ | |
1508 | return true; | |
1509 | ||
1510 | free_nc_path: | |
1511 | batadv_nc_path_free_ref(nc_path); | |
1512 | out: | |
1513 | /* Packet is not consumed */ | |
1514 | return false; | |
1515 | } | |
1516 | ||
612d2b4f MH |
1517 | /** |
1518 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used | |
1519 | * when decoding coded packets | |
1520 | * @bat_priv: the bat priv with all the soft interface information | |
1521 | * @skb: data skb to store | |
1522 | */ | |
1523 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1524 | struct sk_buff *skb) | |
1525 | { | |
1526 | struct batadv_unicast_packet *packet; | |
1527 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1528 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1529 | __be32 packet_id; |
1530 | u8 *payload; | |
1531 | ||
1532 | /* Check if network coding is enabled */ | |
1533 | if (!atomic_read(&bat_priv->network_coding)) | |
1534 | goto out; | |
1535 | ||
1536 | /* Check for supported packet type */ | |
1537 | payload = skb_network_header(skb); | |
1538 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1539 | if (packet->packet_type != BATADV_UNICAST) |
612d2b4f MH |
1540 | goto out; |
1541 | ||
1542 | /* Find existing nc_path or create a new */ | |
1543 | nc_path = batadv_nc_get_path(bat_priv, | |
1544 | bat_priv->nc.decoding_hash, | |
1545 | ethhdr->h_source, | |
1546 | ethhdr->h_dest); | |
1547 | ||
1548 | if (!nc_path) | |
1549 | goto out; | |
1550 | ||
1551 | /* Clone skb and adjust skb->data to point at batman header */ | |
1552 | skb = skb_clone(skb, GFP_ATOMIC); | |
1553 | if (unlikely(!skb)) | |
1554 | goto free_nc_path; | |
1555 | ||
1556 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1557 | goto free_skb; | |
1558 | ||
1559 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1560 | goto free_skb; | |
1561 | ||
1562 | /* Add skb to nc_path */ | |
1563 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1564 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1565 | goto free_skb; | |
1566 | ||
1567 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1568 | return; | |
1569 | ||
1570 | free_skb: | |
1571 | kfree_skb(skb); | |
1572 | free_nc_path: | |
1573 | batadv_nc_path_free_ref(nc_path); | |
1574 | out: | |
1575 | return; | |
1576 | } | |
1577 | ||
1578 | /** | |
1579 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet | |
1580 | * should be saved in the decoding buffer and, if so, store it there | |
1581 | * @bat_priv: the bat priv with all the soft interface information | |
1582 | * @skb: unicast skb to store | |
1583 | */ | |
1584 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1585 | struct sk_buff *skb) | |
1586 | { | |
7ed4be95 | 1587 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1588 | |
6e0895c2 | 1589 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1590 | return; |
1591 | ||
1592 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1593 | skb_push(skb, ETH_HLEN); | |
1594 | ||
1595 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1596 | } | |
1597 | ||
2df5278b MH |
1598 | /** |
1599 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored | |
1600 | * in nc_packet | |
6e0895c2 | 1601 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1602 | * @skb: unicast skb to decode |
1603 | * @nc_packet: decode data needed to decode the skb | |
1604 | * | |
1605 | * Returns pointer to decoded unicast packet if the packet was decoded or NULL | |
1606 | * in case of an error. | |
1607 | */ | |
1608 | static struct batadv_unicast_packet * | |
6e0895c2 | 1609 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1610 | struct batadv_nc_packet *nc_packet) |
1611 | { | |
1612 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1613 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1614 | struct batadv_unicast_packet *unicast_packet; | |
1615 | struct batadv_coded_packet coded_packet_tmp; | |
1616 | struct ethhdr *ethhdr, ethhdr_tmp; | |
1617 | uint8_t *orig_dest, ttl, ttvn; | |
1618 | unsigned int coding_len; | |
7da19971 | 1619 | int err; |
2df5278b MH |
1620 | |
1621 | /* Save headers temporarily */ | |
1622 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1623 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1624 | ||
1625 | if (skb_cow(skb, 0) < 0) | |
1626 | return NULL; | |
1627 | ||
1628 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1629 | return NULL; | |
1630 | ||
1631 | /* Data points to batman header, so set mac header 14 bytes before | |
1632 | * and network to data | |
1633 | */ | |
1634 | skb_set_mac_header(skb, -ETH_HLEN); | |
1635 | skb_reset_network_header(skb); | |
1636 | ||
1637 | /* Reconstruct original mac header */ | |
7ed4be95 | 1638 | ethhdr = eth_hdr(skb); |
abae9479 | 1639 | *ethhdr = ethhdr_tmp; |
2df5278b MH |
1640 | |
1641 | /* Select the correct unicast header information based on the location | |
1642 | * of our mac address in the coded_packet header | |
1643 | */ | |
6e0895c2 | 1644 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1645 | /* If we are the second destination the packet was overheard, |
1646 | * so the Ethernet address must be copied to h_dest and | |
1647 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1648 | */ | |
8fdd0153 | 1649 | ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest); |
2df5278b MH |
1650 | skb->pkt_type = PACKET_HOST; |
1651 | ||
1652 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1653 | ttl = coded_packet_tmp.second_ttl; | |
1654 | ttvn = coded_packet_tmp.second_ttvn; | |
1655 | } else { | |
1656 | orig_dest = coded_packet_tmp.first_orig_dest; | |
a40d9b07 | 1657 | ttl = coded_packet_tmp.ttl; |
2df5278b MH |
1658 | ttvn = coded_packet_tmp.first_ttvn; |
1659 | } | |
1660 | ||
1661 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1662 | ||
1663 | if (coding_len > skb->len) | |
1664 | return NULL; | |
1665 | ||
1666 | /* Here the magic is reversed: | |
1667 | * extract the missing packet from the received coded packet | |
1668 | */ | |
1669 | batadv_nc_memxor(skb->data + h_size, | |
1670 | nc_packet->skb->data + h_size, | |
1671 | coding_len); | |
1672 | ||
1673 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1674 | if (nc_packet->skb->len > coding_len + h_size) { |
1675 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1676 | if (err) | |
1677 | return NULL; | |
1678 | } | |
2df5278b MH |
1679 | |
1680 | /* Create decoded unicast packet */ | |
1681 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
a40d9b07 SW |
1682 | unicast_packet->packet_type = BATADV_UNICAST; |
1683 | unicast_packet->version = BATADV_COMPAT_VERSION; | |
1684 | unicast_packet->ttl = ttl; | |
8fdd0153 | 1685 | ether_addr_copy(unicast_packet->dest, orig_dest); |
2df5278b MH |
1686 | unicast_packet->ttvn = ttvn; |
1687 | ||
1688 | batadv_nc_packet_free(nc_packet); | |
1689 | return unicast_packet; | |
1690 | } | |
1691 | ||
1692 | /** | |
1693 | * batadv_nc_find_decoding_packet - search through buffered decoding data to | |
1694 | * find the data needed to decode the coded packet | |
1695 | * @bat_priv: the bat priv with all the soft interface information | |
1696 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1697 | * @coded: coded packet we try to find decode data for | |
1698 | * | |
1699 | * Returns pointer to nc packet if the needed data was found or NULL otherwise. | |
1700 | */ | |
1701 | static struct batadv_nc_packet * | |
1702 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1703 | struct ethhdr *ethhdr, | |
1704 | struct batadv_coded_packet *coded) | |
1705 | { | |
1706 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1707 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1708 | struct batadv_nc_path *nc_path, nc_path_key; | |
1709 | uint8_t *dest, *source; | |
1710 | __be32 packet_id; | |
1711 | int index; | |
1712 | ||
1713 | if (!hash) | |
1714 | return NULL; | |
1715 | ||
1716 | /* Select the correct packet id based on the location of our mac-addr */ | |
1717 | dest = ethhdr->h_source; | |
6e0895c2 | 1718 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1719 | source = coded->second_source; |
1720 | packet_id = coded->second_crc; | |
1721 | } else { | |
1722 | source = coded->first_source; | |
1723 | packet_id = coded->first_crc; | |
1724 | } | |
1725 | ||
1726 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1727 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1728 | ||
1729 | /* Search for matching coding path */ | |
1730 | rcu_read_lock(); | |
1731 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1732 | /* Find matching nc_packet */ | |
1733 | spin_lock_bh(&nc_path->packet_list_lock); | |
1734 | list_for_each_entry(tmp_nc_packet, | |
1735 | &nc_path->packet_list, list) { | |
1736 | if (packet_id == tmp_nc_packet->packet_id) { | |
1737 | list_del(&tmp_nc_packet->list); | |
1738 | ||
1739 | nc_packet = tmp_nc_packet; | |
1740 | break; | |
1741 | } | |
1742 | } | |
1743 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1744 | ||
1745 | if (nc_packet) | |
1746 | break; | |
1747 | } | |
1748 | rcu_read_unlock(); | |
1749 | ||
1750 | if (!nc_packet) | |
1751 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1752 | "No decoding packet found for %u\n", packet_id); | |
1753 | ||
1754 | return nc_packet; | |
1755 | } | |
1756 | ||
1757 | /** | |
1758 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the | |
1759 | * resulting unicast packet | |
1760 | * @skb: incoming coded packet | |
1761 | * @recv_if: pointer to interface this packet was received on | |
1762 | */ | |
1763 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1764 | struct batadv_hard_iface *recv_if) | |
1765 | { | |
1766 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1767 | struct batadv_unicast_packet *unicast_packet; | |
1768 | struct batadv_coded_packet *coded_packet; | |
1769 | struct batadv_nc_packet *nc_packet; | |
1770 | struct ethhdr *ethhdr; | |
1771 | int hdr_size = sizeof(*coded_packet); | |
1772 | ||
1773 | /* Check if network coding is enabled */ | |
1774 | if (!atomic_read(&bat_priv->network_coding)) | |
1775 | return NET_RX_DROP; | |
1776 | ||
1777 | /* Make sure we can access (and remove) header */ | |
1778 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
1779 | return NET_RX_DROP; | |
1780 | ||
1781 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1782 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1783 | |
1784 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1785 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1786 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
2df5278b MH |
1787 | return NET_RX_DROP; |
1788 | ||
1789 | /* Update stat counter */ | |
6e0895c2 | 1790 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1791 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1792 | ||
1793 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1794 | coded_packet); | |
1795 | if (!nc_packet) { | |
1796 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1797 | return NET_RX_DROP; | |
1798 | } | |
1799 | ||
1800 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1801 | if (skb_linearize(skb) < 0) | |
1802 | goto free_nc_packet; | |
1803 | ||
1804 | if (skb_linearize(nc_packet->skb) < 0) | |
1805 | goto free_nc_packet; | |
1806 | ||
1807 | /* Decode the packet */ | |
6e0895c2 | 1808 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1809 | if (!unicast_packet) { |
1810 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1811 | goto free_nc_packet; | |
1812 | } | |
1813 | ||
1814 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1815 | BATADV_SKB_CB(skb)->decoded = true; | |
1816 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1817 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1818 | skb->len + ETH_HLEN); | |
1819 | return batadv_recv_unicast_packet(skb, recv_if); | |
1820 | ||
1821 | free_nc_packet: | |
1822 | batadv_nc_packet_free(nc_packet); | |
1823 | return NET_RX_DROP; | |
1824 | } | |
1825 | ||
d353d8d4 | 1826 | /** |
6c519bad | 1827 | * batadv_nc_mesh_free - clean up network coding memory |
d353d8d4 MH |
1828 | * @bat_priv: the bat priv with all the soft interface information |
1829 | */ | |
6c519bad | 1830 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
d353d8d4 | 1831 | { |
3f4841ff ML |
1832 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1833 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
d353d8d4 | 1834 | cancel_delayed_work_sync(&bat_priv->nc.work); |
612d2b4f | 1835 | |
95332477 MH |
1836 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1837 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1838 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1839 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1840 | } |
d56b1705 MH |
1841 | |
1842 | /** | |
1843 | * batadv_nc_nodes_seq_print_text - print the nc node information | |
1844 | * @seq: seq file to print on | |
1845 | * @offset: not used | |
1846 | */ | |
1847 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) | |
1848 | { | |
1849 | struct net_device *net_dev = (struct net_device *)seq->private; | |
1850 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
1851 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
1852 | struct batadv_hard_iface *primary_if; | |
1853 | struct hlist_head *head; | |
1854 | struct batadv_orig_node *orig_node; | |
1855 | struct batadv_nc_node *nc_node; | |
1856 | int i; | |
1857 | ||
1858 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
1859 | if (!primary_if) | |
1860 | goto out; | |
1861 | ||
1862 | /* Traverse list of originators */ | |
1863 | for (i = 0; i < hash->size; i++) { | |
1864 | head = &hash->table[i]; | |
1865 | ||
1866 | /* For each orig_node in this bin */ | |
1867 | rcu_read_lock(); | |
1868 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { | |
aa27c312 ML |
1869 | /* no need to print the orig node if it does not have |
1870 | * network coding neighbors | |
1871 | */ | |
1872 | if (list_empty(&orig_node->in_coding_list) && | |
1873 | list_empty(&orig_node->out_coding_list)) | |
1874 | continue; | |
1875 | ||
d56b1705 MH |
1876 | seq_printf(seq, "Node: %pM\n", orig_node->orig); |
1877 | ||
0c814653 | 1878 | seq_puts(seq, " Ingoing: "); |
d56b1705 MH |
1879 | /* For each in_nc_node to this orig_node */ |
1880 | list_for_each_entry_rcu(nc_node, | |
1881 | &orig_node->in_coding_list, | |
1882 | list) | |
1883 | seq_printf(seq, "%pM ", | |
1884 | nc_node->addr); | |
0c814653 | 1885 | seq_puts(seq, "\n"); |
d56b1705 | 1886 | |
0c814653 | 1887 | seq_puts(seq, " Outgoing: "); |
d56b1705 MH |
1888 | /* For out_nc_node to this orig_node */ |
1889 | list_for_each_entry_rcu(nc_node, | |
1890 | &orig_node->out_coding_list, | |
1891 | list) | |
1892 | seq_printf(seq, "%pM ", | |
1893 | nc_node->addr); | |
0c814653 | 1894 | seq_puts(seq, "\n\n"); |
d56b1705 MH |
1895 | } |
1896 | rcu_read_unlock(); | |
1897 | } | |
1898 | ||
1899 | out: | |
1900 | if (primary_if) | |
1901 | batadv_hardif_free_ref(primary_if); | |
1902 | return 0; | |
1903 | } | |
1904 | ||
1905 | /** | |
1906 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs | |
1907 | * @bat_priv: the bat priv with all the soft interface information | |
1908 | */ | |
1909 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) | |
1910 | { | |
1911 | struct dentry *nc_dir, *file; | |
1912 | ||
1913 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); | |
1914 | if (!nc_dir) | |
1915 | goto out; | |
1916 | ||
1917 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, | |
1918 | &bat_priv->nc.min_tq); | |
1919 | if (!file) | |
1920 | goto out; | |
1921 | ||
95332477 MH |
1922 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1923 | &bat_priv->nc.max_fwd_delay); | |
1924 | if (!file) | |
1925 | goto out; | |
1926 | ||
612d2b4f MH |
1927 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1928 | &bat_priv->nc.max_buffer_time); | |
1929 | if (!file) | |
1930 | goto out; | |
1931 | ||
d56b1705 MH |
1932 | return 0; |
1933 | ||
1934 | out: | |
1935 | return -ENOMEM; | |
1936 | } |