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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 | ||
1e2c2a4f SE |
18 | #include "network-coding.h" |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/atomic.h> | |
22 | #include <linux/byteorder/generic.h> | |
23 | #include <linux/compiler.h> | |
d56b1705 | 24 | #include <linux/debugfs.h> |
1e2c2a4f SE |
25 | #include <linux/errno.h> |
26 | #include <linux/etherdevice.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/if_ether.h> | |
29 | #include <linux/if_packet.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/jhash.h> | |
32 | #include <linux/jiffies.h> | |
33 | #include <linux/kernel.h> | |
34 | #include <linux/list.h> | |
35 | #include <linux/lockdep.h> | |
36 | #include <linux/netdevice.h> | |
37 | #include <linux/printk.h> | |
38 | #include <linux/random.h> | |
39 | #include <linux/rculist.h> | |
40 | #include <linux/rcupdate.h> | |
41 | #include <linux/seq_file.h> | |
42 | #include <linux/skbuff.h> | |
43 | #include <linux/slab.h> | |
44 | #include <linux/spinlock.h> | |
45 | #include <linux/stat.h> | |
46 | #include <linux/stddef.h> | |
47 | #include <linux/string.h> | |
48 | #include <linux/workqueue.h> | |
d56b1705 | 49 | |
1e2c2a4f | 50 | #include "hard-interface.h" |
95332477 | 51 | #include "hash.h" |
d56b1705 | 52 | #include "originator.h" |
1e2c2a4f | 53 | #include "packet.h" |
2df5278b | 54 | #include "routing.h" |
1e2c2a4f | 55 | #include "send.h" |
d353d8d4 | 56 | |
95332477 | 57 | static struct lock_class_key batadv_nc_coding_hash_lock_class_key; |
612d2b4f | 58 | static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; |
95332477 | 59 | |
d353d8d4 | 60 | static void batadv_nc_worker(struct work_struct *work); |
2df5278b MH |
61 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, |
62 | struct batadv_hard_iface *recv_if); | |
d353d8d4 | 63 | |
6c519bad MS |
64 | /** |
65 | * batadv_nc_init - one-time initialization for network coding | |
66 | */ | |
67 | int __init batadv_nc_init(void) | |
68 | { | |
69 | int ret; | |
70 | ||
71 | /* Register our packet type */ | |
72 | ret = batadv_recv_handler_register(BATADV_CODED, | |
73 | batadv_nc_recv_coded_packet); | |
74 | ||
75 | return ret; | |
76 | } | |
77 | ||
d353d8d4 MH |
78 | /** |
79 | * batadv_nc_start_timer - initialise the nc periodic worker | |
80 | * @bat_priv: the bat priv with all the soft interface information | |
81 | */ | |
82 | static void batadv_nc_start_timer(struct batadv_priv *bat_priv) | |
83 | { | |
84 | queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work, | |
85 | msecs_to_jiffies(10)); | |
86 | } | |
87 | ||
3f4841ff ML |
88 | /** |
89 | * batadv_nc_tvlv_container_update - update the network coding tvlv container | |
90 | * after network coding setting change | |
91 | * @bat_priv: the bat priv with all the soft interface information | |
92 | */ | |
93 | static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv) | |
94 | { | |
95 | char nc_mode; | |
96 | ||
97 | nc_mode = atomic_read(&bat_priv->network_coding); | |
98 | ||
99 | switch (nc_mode) { | |
100 | case 0: | |
101 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
102 | break; | |
103 | case 1: | |
104 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1, | |
105 | NULL, 0); | |
106 | break; | |
107 | } | |
108 | } | |
109 | ||
110 | /** | |
111 | * batadv_nc_status_update - update the network coding tvlv container after | |
112 | * network coding setting change | |
113 | * @net_dev: the soft interface net device | |
114 | */ | |
115 | void batadv_nc_status_update(struct net_device *net_dev) | |
116 | { | |
117 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 118 | |
3f4841ff ML |
119 | batadv_nc_tvlv_container_update(bat_priv); |
120 | } | |
121 | ||
122 | /** | |
123 | * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container | |
124 | * @bat_priv: the bat priv with all the soft interface information | |
125 | * @orig: the orig_node of the ogm | |
126 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
127 | * @tvlv_value: tvlv buffer containing the gateway data | |
128 | * @tvlv_value_len: tvlv buffer length | |
129 | */ | |
130 | static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
131 | struct batadv_orig_node *orig, | |
132 | uint8_t flags, | |
133 | void *tvlv_value, | |
134 | uint16_t tvlv_value_len) | |
135 | { | |
136 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
137 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC; | |
138 | else | |
139 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC; | |
140 | } | |
141 | ||
d353d8d4 | 142 | /** |
6c519bad | 143 | * batadv_nc_mesh_init - initialise coding hash table and start house keeping |
d353d8d4 MH |
144 | * @bat_priv: the bat priv with all the soft interface information |
145 | */ | |
6c519bad | 146 | int batadv_nc_mesh_init(struct batadv_priv *bat_priv) |
d353d8d4 | 147 | { |
95332477 | 148 | bat_priv->nc.timestamp_fwd_flush = jiffies; |
612d2b4f | 149 | bat_priv->nc.timestamp_sniffed_purge = jiffies; |
95332477 | 150 | |
612d2b4f | 151 | if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash) |
95332477 MH |
152 | return 0; |
153 | ||
154 | bat_priv->nc.coding_hash = batadv_hash_new(128); | |
155 | if (!bat_priv->nc.coding_hash) | |
156 | goto err; | |
157 | ||
158 | batadv_hash_set_lock_class(bat_priv->nc.coding_hash, | |
159 | &batadv_nc_coding_hash_lock_class_key); | |
160 | ||
612d2b4f MH |
161 | bat_priv->nc.decoding_hash = batadv_hash_new(128); |
162 | if (!bat_priv->nc.decoding_hash) | |
163 | goto err; | |
164 | ||
f44d5407 | 165 | batadv_hash_set_lock_class(bat_priv->nc.decoding_hash, |
612d2b4f MH |
166 | &batadv_nc_decoding_hash_lock_class_key); |
167 | ||
d353d8d4 MH |
168 | INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); |
169 | batadv_nc_start_timer(bat_priv); | |
170 | ||
3f4841ff ML |
171 | batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1, |
172 | NULL, BATADV_TVLV_NC, 1, | |
173 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
174 | batadv_nc_tvlv_container_update(bat_priv); | |
d353d8d4 | 175 | return 0; |
95332477 MH |
176 | |
177 | err: | |
178 | return -ENOMEM; | |
d353d8d4 MH |
179 | } |
180 | ||
181 | /** | |
182 | * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables | |
183 | * @bat_priv: the bat priv with all the soft interface information | |
184 | */ | |
185 | void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) | |
186 | { | |
dab7b621 | 187 | atomic_set(&bat_priv->network_coding, 0); |
d56b1705 | 188 | bat_priv->nc.min_tq = 200; |
95332477 | 189 | bat_priv->nc.max_fwd_delay = 10; |
612d2b4f | 190 | bat_priv->nc.max_buffer_time = 200; |
d56b1705 MH |
191 | } |
192 | ||
193 | /** | |
194 | * batadv_nc_init_orig - initialise the nc fields of an orig_node | |
195 | * @orig_node: the orig_node which is going to be initialised | |
196 | */ | |
197 | void batadv_nc_init_orig(struct batadv_orig_node *orig_node) | |
198 | { | |
199 | INIT_LIST_HEAD(&orig_node->in_coding_list); | |
200 | INIT_LIST_HEAD(&orig_node->out_coding_list); | |
201 | spin_lock_init(&orig_node->in_coding_list_lock); | |
202 | spin_lock_init(&orig_node->out_coding_list_lock); | |
203 | } | |
204 | ||
205 | /** | |
206 | * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove | |
207 | * its refcount on the orig_node | |
208 | * @rcu: rcu pointer of the nc node | |
209 | */ | |
210 | static void batadv_nc_node_free_rcu(struct rcu_head *rcu) | |
211 | { | |
212 | struct batadv_nc_node *nc_node; | |
213 | ||
214 | nc_node = container_of(rcu, struct batadv_nc_node, rcu); | |
215 | batadv_orig_node_free_ref(nc_node->orig_node); | |
216 | kfree(nc_node); | |
217 | } | |
218 | ||
219 | /** | |
220 | * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly | |
221 | * frees it | |
222 | * @nc_node: the nc node to free | |
223 | */ | |
224 | static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) | |
225 | { | |
226 | if (atomic_dec_and_test(&nc_node->refcount)) | |
227 | call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu); | |
228 | } | |
229 | ||
95332477 MH |
230 | /** |
231 | * batadv_nc_path_free_ref - decrements the nc path refcounter and possibly | |
232 | * frees it | |
233 | * @nc_path: the nc node to free | |
234 | */ | |
235 | static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) | |
236 | { | |
237 | if (atomic_dec_and_test(&nc_path->refcount)) | |
238 | kfree_rcu(nc_path, rcu); | |
239 | } | |
240 | ||
241 | /** | |
242 | * batadv_nc_packet_free - frees nc packet | |
243 | * @nc_packet: the nc packet to free | |
244 | */ | |
245 | static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) | |
246 | { | |
247 | if (nc_packet->skb) | |
248 | kfree_skb(nc_packet->skb); | |
249 | ||
250 | batadv_nc_path_free_ref(nc_packet->nc_path); | |
251 | kfree(nc_packet); | |
252 | } | |
253 | ||
d56b1705 MH |
254 | /** |
255 | * batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged | |
256 | * @bat_priv: the bat priv with all the soft interface information | |
257 | * @nc_node: the nc node to check | |
258 | * | |
259 | * Returns true if the entry has to be purged now, false otherwise | |
260 | */ | |
261 | static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, | |
262 | struct batadv_nc_node *nc_node) | |
263 | { | |
264 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
265 | return true; | |
266 | ||
267 | return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT); | |
268 | } | |
269 | ||
95332477 MH |
270 | /** |
271 | * batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out | |
272 | * @bat_priv: the bat priv with all the soft interface information | |
273 | * @nc_path: the nc path to check | |
274 | * | |
275 | * Returns true if the entry has to be purged now, false otherwise | |
276 | */ | |
277 | static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv, | |
278 | struct batadv_nc_path *nc_path) | |
279 | { | |
280 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
281 | return true; | |
282 | ||
283 | /* purge the path when no packets has been added for 10 times the | |
284 | * max_fwd_delay time | |
285 | */ | |
286 | return batadv_has_timed_out(nc_path->last_valid, | |
287 | bat_priv->nc.max_fwd_delay * 10); | |
288 | } | |
289 | ||
612d2b4f MH |
290 | /** |
291 | * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out | |
292 | * @bat_priv: the bat priv with all the soft interface information | |
293 | * @nc_path: the nc path to check | |
294 | * | |
295 | * Returns true if the entry has to be purged now, false otherwise | |
296 | */ | |
297 | static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv, | |
298 | struct batadv_nc_path *nc_path) | |
299 | { | |
300 | if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) | |
301 | return true; | |
302 | ||
303 | /* purge the path when no packets has been added for 10 times the | |
304 | * max_buffer time | |
305 | */ | |
306 | return batadv_has_timed_out(nc_path->last_valid, | |
fc1f8693 | 307 | bat_priv->nc.max_buffer_time * 10); |
612d2b4f MH |
308 | } |
309 | ||
d56b1705 MH |
310 | /** |
311 | * batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale | |
312 | * entries | |
313 | * @bat_priv: the bat priv with all the soft interface information | |
314 | * @list: list of nc nodes | |
315 | * @lock: nc node list lock | |
316 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
317 | * not. This function takes the nc node as argument and has to return | |
318 | * a boolean value: true if the entry has to be deleted, false | |
319 | * otherwise | |
320 | */ | |
321 | static void | |
322 | batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv, | |
323 | struct list_head *list, | |
324 | spinlock_t *lock, | |
325 | bool (*to_purge)(struct batadv_priv *, | |
326 | struct batadv_nc_node *)) | |
327 | { | |
328 | struct batadv_nc_node *nc_node, *nc_node_tmp; | |
329 | ||
330 | /* For each nc_node in list */ | |
331 | spin_lock_bh(lock); | |
332 | list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) { | |
333 | /* if an helper function has been passed as parameter, | |
334 | * ask it if the entry has to be purged or not | |
335 | */ | |
336 | if (to_purge && !to_purge(bat_priv, nc_node)) | |
337 | continue; | |
338 | ||
339 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
340 | "Removing nc_node %pM -> %pM\n", | |
341 | nc_node->addr, nc_node->orig_node->orig); | |
342 | list_del_rcu(&nc_node->list); | |
343 | batadv_nc_node_free_ref(nc_node); | |
344 | } | |
345 | spin_unlock_bh(lock); | |
346 | } | |
347 | ||
348 | /** | |
349 | * batadv_nc_purge_orig - purges all nc node data attached of the given | |
350 | * originator | |
351 | * @bat_priv: the bat priv with all the soft interface information | |
352 | * @orig_node: orig_node with the nc node entries to be purged | |
353 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
354 | * not. This function takes the nc node as argument and has to return | |
355 | * a boolean value: true is the entry has to be deleted, false | |
356 | * otherwise | |
357 | */ | |
358 | void batadv_nc_purge_orig(struct batadv_priv *bat_priv, | |
359 | struct batadv_orig_node *orig_node, | |
360 | bool (*to_purge)(struct batadv_priv *, | |
361 | struct batadv_nc_node *)) | |
362 | { | |
363 | /* Check ingoing nc_node's of this orig_node */ | |
364 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list, | |
365 | &orig_node->in_coding_list_lock, | |
366 | to_purge); | |
367 | ||
368 | /* Check outgoing nc_node's of this orig_node */ | |
369 | batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list, | |
370 | &orig_node->out_coding_list_lock, | |
371 | to_purge); | |
372 | } | |
373 | ||
374 | /** | |
375 | * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they | |
376 | * have timed out nc nodes | |
377 | * @bat_priv: the bat priv with all the soft interface information | |
378 | */ | |
379 | static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) | |
380 | { | |
381 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
382 | struct hlist_head *head; | |
383 | struct batadv_orig_node *orig_node; | |
384 | uint32_t i; | |
385 | ||
386 | if (!hash) | |
387 | return; | |
388 | ||
389 | /* For each orig_node */ | |
390 | for (i = 0; i < hash->size; i++) { | |
391 | head = &hash->table[i]; | |
392 | ||
393 | rcu_read_lock(); | |
394 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) | |
395 | batadv_nc_purge_orig(bat_priv, orig_node, | |
396 | batadv_nc_to_purge_nc_node); | |
397 | rcu_read_unlock(); | |
398 | } | |
d353d8d4 MH |
399 | } |
400 | ||
95332477 MH |
401 | /** |
402 | * batadv_nc_purge_paths - traverse all nc paths part of the hash and remove | |
403 | * unused ones | |
404 | * @bat_priv: the bat priv with all the soft interface information | |
405 | * @hash: hash table containing the nc paths to check | |
406 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
407 | * not. This function takes the nc node as argument and has to return | |
408 | * a boolean value: true is the entry has to be deleted, false | |
409 | * otherwise | |
410 | */ | |
411 | static void batadv_nc_purge_paths(struct batadv_priv *bat_priv, | |
412 | struct batadv_hashtable *hash, | |
413 | bool (*to_purge)(struct batadv_priv *, | |
414 | struct batadv_nc_path *)) | |
415 | { | |
416 | struct hlist_head *head; | |
417 | struct hlist_node *node_tmp; | |
418 | struct batadv_nc_path *nc_path; | |
419 | spinlock_t *lock; /* Protects lists in hash */ | |
420 | uint32_t i; | |
421 | ||
422 | for (i = 0; i < hash->size; i++) { | |
423 | head = &hash->table[i]; | |
424 | lock = &hash->list_locks[i]; | |
425 | ||
426 | /* For each nc_path in this bin */ | |
427 | spin_lock_bh(lock); | |
428 | hlist_for_each_entry_safe(nc_path, node_tmp, head, hash_entry) { | |
429 | /* if an helper function has been passed as parameter, | |
430 | * ask it if the entry has to be purged or not | |
431 | */ | |
432 | if (to_purge && !to_purge(bat_priv, nc_path)) | |
433 | continue; | |
434 | ||
435 | /* purging an non-empty nc_path should never happen, but | |
436 | * is observed under high CPU load. Delay the purging | |
437 | * until next iteration to allow the packet_list to be | |
438 | * emptied first. | |
439 | */ | |
440 | if (!unlikely(list_empty(&nc_path->packet_list))) { | |
441 | net_ratelimited_function(printk, | |
442 | KERN_WARNING | |
443 | "Skipping free of non-empty nc_path (%pM -> %pM)!\n", | |
444 | nc_path->prev_hop, | |
445 | nc_path->next_hop); | |
446 | continue; | |
447 | } | |
448 | ||
449 | /* nc_path is unused, so remove it */ | |
450 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
451 | "Remove nc_path %pM -> %pM\n", | |
452 | nc_path->prev_hop, nc_path->next_hop); | |
453 | hlist_del_rcu(&nc_path->hash_entry); | |
454 | batadv_nc_path_free_ref(nc_path); | |
455 | } | |
456 | spin_unlock_bh(lock); | |
457 | } | |
458 | } | |
459 | ||
460 | /** | |
461 | * batadv_nc_hash_key_gen - computes the nc_path hash key | |
462 | * @key: buffer to hold the final hash key | |
463 | * @src: source ethernet mac address going into the hash key | |
464 | * @dst: destination ethernet mac address going into the hash key | |
465 | */ | |
466 | static void batadv_nc_hash_key_gen(struct batadv_nc_path *key, const char *src, | |
467 | const char *dst) | |
468 | { | |
469 | memcpy(key->prev_hop, src, sizeof(key->prev_hop)); | |
470 | memcpy(key->next_hop, dst, sizeof(key->next_hop)); | |
471 | } | |
472 | ||
473 | /** | |
474 | * batadv_nc_hash_choose - compute the hash value for an nc path | |
475 | * @data: data to hash | |
476 | * @size: size of the hash table | |
477 | * | |
478 | * Returns the selected index in the hash table for the given data. | |
479 | */ | |
480 | static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) | |
481 | { | |
482 | const struct batadv_nc_path *nc_path = data; | |
483 | uint32_t hash = 0; | |
484 | ||
36fd61cb SE |
485 | hash = jhash(&nc_path->prev_hop, sizeof(nc_path->prev_hop), hash); |
486 | hash = jhash(&nc_path->next_hop, sizeof(nc_path->next_hop), hash); | |
95332477 MH |
487 | |
488 | return hash % size; | |
489 | } | |
490 | ||
491 | /** | |
492 | * batadv_nc_hash_compare - comparing function used in the network coding hash | |
493 | * tables | |
494 | * @node: node in the local table | |
495 | * @data2: second object to compare the node to | |
496 | * | |
497 | * Returns 1 if the two entry are the same, 0 otherwise | |
498 | */ | |
499 | static int batadv_nc_hash_compare(const struct hlist_node *node, | |
500 | const void *data2) | |
501 | { | |
502 | const struct batadv_nc_path *nc_path1, *nc_path2; | |
503 | ||
504 | nc_path1 = container_of(node, struct batadv_nc_path, hash_entry); | |
505 | nc_path2 = data2; | |
506 | ||
507 | /* Return 1 if the two keys are identical */ | |
508 | if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop, | |
509 | sizeof(nc_path1->prev_hop)) != 0) | |
510 | return 0; | |
511 | ||
512 | if (memcmp(nc_path1->next_hop, nc_path2->next_hop, | |
513 | sizeof(nc_path1->next_hop)) != 0) | |
514 | return 0; | |
515 | ||
516 | return 1; | |
517 | } | |
518 | ||
519 | /** | |
520 | * batadv_nc_hash_find - search for an existing nc path and return it | |
521 | * @hash: hash table containing the nc path | |
522 | * @data: search key | |
523 | * | |
524 | * Returns the nc_path if found, NULL otherwise. | |
525 | */ | |
526 | static struct batadv_nc_path * | |
527 | batadv_nc_hash_find(struct batadv_hashtable *hash, | |
528 | void *data) | |
529 | { | |
530 | struct hlist_head *head; | |
531 | struct batadv_nc_path *nc_path, *nc_path_tmp = NULL; | |
532 | int index; | |
533 | ||
534 | if (!hash) | |
535 | return NULL; | |
536 | ||
537 | index = batadv_nc_hash_choose(data, hash->size); | |
538 | head = &hash->table[index]; | |
539 | ||
540 | rcu_read_lock(); | |
541 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
542 | if (!batadv_nc_hash_compare(&nc_path->hash_entry, data)) | |
543 | continue; | |
544 | ||
545 | if (!atomic_inc_not_zero(&nc_path->refcount)) | |
546 | continue; | |
547 | ||
548 | nc_path_tmp = nc_path; | |
549 | break; | |
550 | } | |
551 | rcu_read_unlock(); | |
552 | ||
553 | return nc_path_tmp; | |
554 | } | |
555 | ||
556 | /** | |
557 | * batadv_nc_send_packet - send non-coded packet and free nc_packet struct | |
558 | * @nc_packet: the nc packet to send | |
559 | */ | |
560 | static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) | |
561 | { | |
562 | batadv_send_skb_packet(nc_packet->skb, | |
563 | nc_packet->neigh_node->if_incoming, | |
564 | nc_packet->nc_path->next_hop); | |
565 | nc_packet->skb = NULL; | |
566 | batadv_nc_packet_free(nc_packet); | |
567 | } | |
568 | ||
612d2b4f MH |
569 | /** |
570 | * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet. | |
571 | * @bat_priv: the bat priv with all the soft interface information | |
572 | * @nc_path: the nc path the packet belongs to | |
573 | * @nc_packet: the nc packet to be checked | |
574 | * | |
575 | * Checks whether the given sniffed (overheard) nc_packet has hit its buffering | |
576 | * timeout. If so, the packet is no longer kept and the entry deleted from the | |
577 | * queue. Has to be called with the appropriate locks. | |
578 | * | |
579 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
580 | * yet and true otherwise. | |
581 | */ | |
582 | static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv, | |
583 | struct batadv_nc_path *nc_path, | |
584 | struct batadv_nc_packet *nc_packet) | |
585 | { | |
586 | unsigned long timeout = bat_priv->nc.max_buffer_time; | |
587 | bool res = false; | |
588 | ||
589 | /* Packets are added to tail, so the remaining packets did not time | |
590 | * out and we can stop processing the current queue | |
591 | */ | |
592 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
593 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
594 | goto out; | |
595 | ||
596 | /* purge nc packet */ | |
597 | list_del(&nc_packet->list); | |
598 | batadv_nc_packet_free(nc_packet); | |
599 | ||
600 | res = true; | |
601 | ||
602 | out: | |
603 | return res; | |
604 | } | |
605 | ||
95332477 MH |
606 | /** |
607 | * batadv_nc_fwd_flush - Checks the timestamp of the given nc packet. | |
608 | * @bat_priv: the bat priv with all the soft interface information | |
609 | * @nc_path: the nc path the packet belongs to | |
610 | * @nc_packet: the nc packet to be checked | |
611 | * | |
612 | * Checks whether the given nc packet has hit its forward timeout. If so, the | |
613 | * packet is no longer delayed, immediately sent and the entry deleted from the | |
614 | * queue. Has to be called with the appropriate locks. | |
615 | * | |
616 | * Returns false as soon as the entry in the fifo queue has not been timed out | |
617 | * yet and true otherwise. | |
618 | */ | |
619 | static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv, | |
620 | struct batadv_nc_path *nc_path, | |
621 | struct batadv_nc_packet *nc_packet) | |
622 | { | |
623 | unsigned long timeout = bat_priv->nc.max_fwd_delay; | |
624 | ||
625 | /* Packets are added to tail, so the remaining packets did not time | |
626 | * out and we can stop processing the current queue | |
627 | */ | |
628 | if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE && | |
629 | !batadv_has_timed_out(nc_packet->timestamp, timeout)) | |
630 | return false; | |
631 | ||
632 | /* Send packet */ | |
633 | batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); | |
634 | batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, | |
635 | nc_packet->skb->len + ETH_HLEN); | |
636 | list_del(&nc_packet->list); | |
637 | batadv_nc_send_packet(nc_packet); | |
638 | ||
639 | return true; | |
640 | } | |
641 | ||
642 | /** | |
643 | * batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out | |
644 | * nc packets | |
645 | * @bat_priv: the bat priv with all the soft interface information | |
646 | * @hash: to be processed hash table | |
647 | * @process_fn: Function called to process given nc packet. Should return true | |
648 | * to encourage this function to proceed with the next packet. | |
649 | * Otherwise the rest of the current queue is skipped. | |
650 | */ | |
651 | static void | |
652 | batadv_nc_process_nc_paths(struct batadv_priv *bat_priv, | |
653 | struct batadv_hashtable *hash, | |
654 | bool (*process_fn)(struct batadv_priv *, | |
655 | struct batadv_nc_path *, | |
656 | struct batadv_nc_packet *)) | |
657 | { | |
658 | struct hlist_head *head; | |
659 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
660 | struct batadv_nc_path *nc_path; | |
661 | bool ret; | |
662 | int i; | |
663 | ||
664 | if (!hash) | |
665 | return; | |
666 | ||
667 | /* Loop hash table bins */ | |
668 | for (i = 0; i < hash->size; i++) { | |
669 | head = &hash->table[i]; | |
670 | ||
671 | /* Loop coding paths */ | |
672 | rcu_read_lock(); | |
673 | hlist_for_each_entry_rcu(nc_path, head, hash_entry) { | |
674 | /* Loop packets */ | |
675 | spin_lock_bh(&nc_path->packet_list_lock); | |
676 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
677 | &nc_path->packet_list, list) { | |
678 | ret = process_fn(bat_priv, nc_path, nc_packet); | |
679 | if (!ret) | |
680 | break; | |
681 | } | |
682 | spin_unlock_bh(&nc_path->packet_list_lock); | |
683 | } | |
684 | rcu_read_unlock(); | |
685 | } | |
686 | } | |
687 | ||
d353d8d4 MH |
688 | /** |
689 | * batadv_nc_worker - periodic task for house keeping related to network coding | |
690 | * @work: kernel work struct | |
691 | */ | |
692 | static void batadv_nc_worker(struct work_struct *work) | |
693 | { | |
694 | struct delayed_work *delayed_work; | |
695 | struct batadv_priv_nc *priv_nc; | |
696 | struct batadv_priv *bat_priv; | |
95332477 | 697 | unsigned long timeout; |
d353d8d4 MH |
698 | |
699 | delayed_work = container_of(work, struct delayed_work, work); | |
700 | priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); | |
701 | bat_priv = container_of(priv_nc, struct batadv_priv, nc); | |
702 | ||
d56b1705 | 703 | batadv_nc_purge_orig_hash(bat_priv); |
95332477 MH |
704 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, |
705 | batadv_nc_to_purge_nc_path_coding); | |
612d2b4f MH |
706 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, |
707 | batadv_nc_to_purge_nc_path_decoding); | |
95332477 MH |
708 | |
709 | timeout = bat_priv->nc.max_fwd_delay; | |
710 | ||
711 | if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) { | |
712 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash, | |
713 | batadv_nc_fwd_flush); | |
714 | bat_priv->nc.timestamp_fwd_flush = jiffies; | |
715 | } | |
d56b1705 | 716 | |
612d2b4f MH |
717 | if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge, |
718 | bat_priv->nc.max_buffer_time)) { | |
719 | batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash, | |
720 | batadv_nc_sniffed_purge); | |
721 | bat_priv->nc.timestamp_sniffed_purge = jiffies; | |
722 | } | |
723 | ||
d353d8d4 MH |
724 | /* Schedule a new check */ |
725 | batadv_nc_start_timer(bat_priv); | |
726 | } | |
727 | ||
d56b1705 MH |
728 | /** |
729 | * batadv_can_nc_with_orig - checks whether the given orig node is suitable for | |
730 | * coding or not | |
731 | * @bat_priv: the bat priv with all the soft interface information | |
732 | * @orig_node: neighboring orig node which may be used as nc candidate | |
733 | * @ogm_packet: incoming ogm packet also used for the checks | |
734 | * | |
735 | * Returns true if: | |
736 | * 1) The OGM must have the most recent sequence number. | |
737 | * 2) The TTL must be decremented by one and only one. | |
738 | * 3) The OGM must be received from the first hop from orig_node. | |
739 | * 4) The TQ value of the OGM must be above bat_priv->nc.min_tq. | |
740 | */ | |
741 | static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv, | |
742 | struct batadv_orig_node *orig_node, | |
743 | struct batadv_ogm_packet *ogm_packet) | |
744 | { | |
7351a482 SW |
745 | struct batadv_orig_ifinfo *orig_ifinfo; |
746 | uint32_t last_real_seqno; | |
747 | uint8_t last_ttl; | |
748 | ||
749 | orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT); | |
750 | if (!orig_ifinfo) | |
d56b1705 | 751 | return false; |
7351a482 SW |
752 | |
753 | last_ttl = orig_ifinfo->last_ttl; | |
754 | last_real_seqno = orig_ifinfo->last_real_seqno; | |
755 | batadv_orig_ifinfo_free_ref(orig_ifinfo); | |
756 | ||
757 | if (last_real_seqno != ntohl(ogm_packet->seqno)) | |
758 | return false; | |
759 | if (last_ttl != ogm_packet->ttl + 1) | |
d56b1705 MH |
760 | return false; |
761 | if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender)) | |
762 | return false; | |
763 | if (ogm_packet->tq < bat_priv->nc.min_tq) | |
764 | return false; | |
765 | ||
766 | return true; | |
767 | } | |
768 | ||
769 | /** | |
770 | * batadv_nc_find_nc_node - search for an existing nc node and return it | |
771 | * @orig_node: orig node originating the ogm packet | |
772 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
773 | * (can be equal to orig_node) | |
774 | * @in_coding: traverse incoming or outgoing network coding list | |
775 | * | |
776 | * Returns the nc_node if found, NULL otherwise. | |
777 | */ | |
778 | static struct batadv_nc_node | |
779 | *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node, | |
780 | struct batadv_orig_node *orig_neigh_node, | |
781 | bool in_coding) | |
782 | { | |
783 | struct batadv_nc_node *nc_node, *nc_node_out = NULL; | |
784 | struct list_head *list; | |
785 | ||
786 | if (in_coding) | |
787 | list = &orig_neigh_node->in_coding_list; | |
788 | else | |
789 | list = &orig_neigh_node->out_coding_list; | |
790 | ||
791 | /* Traverse list of nc_nodes to orig_node */ | |
792 | rcu_read_lock(); | |
793 | list_for_each_entry_rcu(nc_node, list, list) { | |
794 | if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) | |
795 | continue; | |
796 | ||
797 | if (!atomic_inc_not_zero(&nc_node->refcount)) | |
798 | continue; | |
799 | ||
800 | /* Found a match */ | |
801 | nc_node_out = nc_node; | |
802 | break; | |
803 | } | |
804 | rcu_read_unlock(); | |
805 | ||
806 | return nc_node_out; | |
807 | } | |
808 | ||
809 | /** | |
810 | * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was | |
811 | * not found | |
812 | * @bat_priv: the bat priv with all the soft interface information | |
813 | * @orig_node: orig node originating the ogm packet | |
814 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
815 | * (can be equal to orig_node) | |
816 | * @in_coding: traverse incoming or outgoing network coding list | |
817 | * | |
818 | * Returns the nc_node if found or created, NULL in case of an error. | |
819 | */ | |
820 | static struct batadv_nc_node | |
821 | *batadv_nc_get_nc_node(struct batadv_priv *bat_priv, | |
822 | struct batadv_orig_node *orig_node, | |
823 | struct batadv_orig_node *orig_neigh_node, | |
824 | bool in_coding) | |
825 | { | |
826 | struct batadv_nc_node *nc_node; | |
827 | spinlock_t *lock; /* Used to lock list selected by "int in_coding" */ | |
828 | struct list_head *list; | |
829 | ||
830 | /* Check if nc_node is already added */ | |
831 | nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding); | |
832 | ||
833 | /* Node found */ | |
834 | if (nc_node) | |
835 | return nc_node; | |
836 | ||
837 | nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC); | |
838 | if (!nc_node) | |
839 | return NULL; | |
840 | ||
841 | if (!atomic_inc_not_zero(&orig_neigh_node->refcount)) | |
842 | goto free; | |
843 | ||
844 | /* Initialize nc_node */ | |
845 | INIT_LIST_HEAD(&nc_node->list); | |
8fdd0153 | 846 | ether_addr_copy(nc_node->addr, orig_node->orig); |
d56b1705 MH |
847 | nc_node->orig_node = orig_neigh_node; |
848 | atomic_set(&nc_node->refcount, 2); | |
849 | ||
850 | /* Select ingoing or outgoing coding node */ | |
851 | if (in_coding) { | |
852 | lock = &orig_neigh_node->in_coding_list_lock; | |
853 | list = &orig_neigh_node->in_coding_list; | |
854 | } else { | |
855 | lock = &orig_neigh_node->out_coding_list_lock; | |
856 | list = &orig_neigh_node->out_coding_list; | |
857 | } | |
858 | ||
859 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n", | |
860 | nc_node->addr, nc_node->orig_node->orig); | |
861 | ||
862 | /* Add nc_node to orig_node */ | |
863 | spin_lock_bh(lock); | |
864 | list_add_tail_rcu(&nc_node->list, list); | |
865 | spin_unlock_bh(lock); | |
866 | ||
867 | return nc_node; | |
868 | ||
869 | free: | |
870 | kfree(nc_node); | |
871 | return NULL; | |
872 | } | |
873 | ||
874 | /** | |
875 | * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node structs | |
876 | * (best called on incoming OGMs) | |
877 | * @bat_priv: the bat priv with all the soft interface information | |
878 | * @orig_node: orig node originating the ogm packet | |
879 | * @orig_neigh_node: neighboring orig node from which we received the ogm packet | |
880 | * (can be equal to orig_node) | |
881 | * @ogm_packet: incoming ogm packet | |
882 | * @is_single_hop_neigh: orig_node is a single hop neighbor | |
883 | */ | |
884 | void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, | |
885 | struct batadv_orig_node *orig_node, | |
886 | struct batadv_orig_node *orig_neigh_node, | |
887 | struct batadv_ogm_packet *ogm_packet, | |
888 | int is_single_hop_neigh) | |
889 | { | |
890 | struct batadv_nc_node *in_nc_node = NULL, *out_nc_node = NULL; | |
891 | ||
892 | /* Check if network coding is enabled */ | |
893 | if (!atomic_read(&bat_priv->network_coding)) | |
894 | goto out; | |
895 | ||
3f4841ff ML |
896 | /* check if orig node is network coding enabled */ |
897 | if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC)) | |
898 | goto out; | |
899 | ||
d56b1705 MH |
900 | /* accept ogms from 'good' neighbors and single hop neighbors */ |
901 | if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) && | |
902 | !is_single_hop_neigh) | |
903 | goto out; | |
904 | ||
905 | /* Add orig_node as in_nc_node on hop */ | |
906 | in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node, | |
907 | orig_neigh_node, true); | |
908 | if (!in_nc_node) | |
909 | goto out; | |
910 | ||
911 | in_nc_node->last_seen = jiffies; | |
912 | ||
913 | /* Add hop as out_nc_node on orig_node */ | |
914 | out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node, | |
915 | orig_node, false); | |
916 | if (!out_nc_node) | |
917 | goto out; | |
918 | ||
919 | out_nc_node->last_seen = jiffies; | |
920 | ||
921 | out: | |
922 | if (in_nc_node) | |
923 | batadv_nc_node_free_ref(in_nc_node); | |
924 | if (out_nc_node) | |
925 | batadv_nc_node_free_ref(out_nc_node); | |
926 | } | |
927 | ||
95332477 MH |
928 | /** |
929 | * batadv_nc_get_path - get existing nc_path or allocate a new one | |
930 | * @bat_priv: the bat priv with all the soft interface information | |
931 | * @hash: hash table containing the nc path | |
932 | * @src: ethernet source address - first half of the nc path search key | |
933 | * @dst: ethernet destination address - second half of the nc path search key | |
934 | * | |
935 | * Returns pointer to nc_path if the path was found or created, returns NULL | |
936 | * on error. | |
937 | */ | |
938 | static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv, | |
939 | struct batadv_hashtable *hash, | |
940 | uint8_t *src, | |
941 | uint8_t *dst) | |
942 | { | |
943 | int hash_added; | |
944 | struct batadv_nc_path *nc_path, nc_path_key; | |
945 | ||
946 | batadv_nc_hash_key_gen(&nc_path_key, src, dst); | |
947 | ||
948 | /* Search for existing nc_path */ | |
949 | nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key); | |
950 | ||
951 | if (nc_path) { | |
952 | /* Set timestamp to delay removal of nc_path */ | |
953 | nc_path->last_valid = jiffies; | |
954 | return nc_path; | |
955 | } | |
956 | ||
957 | /* No existing nc_path was found; create a new */ | |
958 | nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC); | |
959 | ||
960 | if (!nc_path) | |
961 | return NULL; | |
962 | ||
963 | /* Initialize nc_path */ | |
964 | INIT_LIST_HEAD(&nc_path->packet_list); | |
965 | spin_lock_init(&nc_path->packet_list_lock); | |
966 | atomic_set(&nc_path->refcount, 2); | |
967 | nc_path->last_valid = jiffies; | |
8fdd0153 AQ |
968 | ether_addr_copy(nc_path->next_hop, dst); |
969 | ether_addr_copy(nc_path->prev_hop, src); | |
95332477 MH |
970 | |
971 | batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n", | |
972 | nc_path->prev_hop, | |
973 | nc_path->next_hop); | |
974 | ||
975 | /* Add nc_path to hash table */ | |
976 | hash_added = batadv_hash_add(hash, batadv_nc_hash_compare, | |
977 | batadv_nc_hash_choose, &nc_path_key, | |
978 | &nc_path->hash_entry); | |
979 | ||
980 | if (hash_added < 0) { | |
981 | kfree(nc_path); | |
982 | return NULL; | |
983 | } | |
984 | ||
985 | return nc_path; | |
986 | } | |
987 | ||
3c12de9a MH |
988 | /** |
989 | * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair | |
990 | * selection of a receiver with slightly lower TQ than the other | |
991 | * @tq: to be weighted tq value | |
992 | */ | |
993 | static uint8_t batadv_nc_random_weight_tq(uint8_t tq) | |
994 | { | |
995 | uint8_t rand_val, rand_tq; | |
996 | ||
997 | get_random_bytes(&rand_val, sizeof(rand_val)); | |
998 | ||
999 | /* randomize the estimated packet loss (max TQ - estimated TQ) */ | |
1000 | rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq); | |
1001 | ||
1002 | /* normalize the randomized packet loss */ | |
1003 | rand_tq /= BATADV_TQ_MAX_VALUE; | |
1004 | ||
1005 | /* convert to (randomized) estimated tq again */ | |
1006 | return BATADV_TQ_MAX_VALUE - rand_tq; | |
1007 | } | |
1008 | ||
1009 | /** | |
1010 | * batadv_nc_memxor - XOR destination with source | |
1011 | * @dst: byte array to XOR into | |
1012 | * @src: byte array to XOR from | |
1013 | * @len: length of destination array | |
1014 | */ | |
1015 | static void batadv_nc_memxor(char *dst, const char *src, unsigned int len) | |
1016 | { | |
1017 | unsigned int i; | |
1018 | ||
1019 | for (i = 0; i < len; ++i) | |
1020 | dst[i] ^= src[i]; | |
1021 | } | |
1022 | ||
1023 | /** | |
1024 | * batadv_nc_code_packets - code a received unicast_packet with an nc packet | |
1025 | * into a coded_packet and send it | |
1026 | * @bat_priv: the bat priv with all the soft interface information | |
1027 | * @skb: data skb to forward | |
1028 | * @ethhdr: pointer to the ethernet header inside the skb | |
1029 | * @nc_packet: structure containing the packet to the skb can be coded with | |
1030 | * @neigh_node: next hop to forward packet to | |
1031 | * | |
1032 | * Returns true if both packets are consumed, false otherwise. | |
1033 | */ | |
1034 | static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, | |
1035 | struct sk_buff *skb, | |
1036 | struct ethhdr *ethhdr, | |
1037 | struct batadv_nc_packet *nc_packet, | |
1038 | struct batadv_neigh_node *neigh_node) | |
1039 | { | |
0538f759 | 1040 | uint8_t tq_weighted_neigh, tq_weighted_coding, tq_tmp; |
3c12de9a MH |
1041 | struct sk_buff *skb_dest, *skb_src; |
1042 | struct batadv_unicast_packet *packet1; | |
1043 | struct batadv_unicast_packet *packet2; | |
1044 | struct batadv_coded_packet *coded_packet; | |
1045 | struct batadv_neigh_node *neigh_tmp, *router_neigh; | |
1046 | struct batadv_neigh_node *router_coding = NULL; | |
89652331 SW |
1047 | struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL; |
1048 | struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL; | |
3c12de9a MH |
1049 | uint8_t *first_source, *first_dest, *second_source, *second_dest; |
1050 | __be32 packet_id1, packet_id2; | |
1051 | size_t count; | |
1052 | bool res = false; | |
1053 | int coding_len; | |
1054 | int unicast_size = sizeof(*packet1); | |
1055 | int coded_size = sizeof(*coded_packet); | |
1056 | int header_add = coded_size - unicast_size; | |
1057 | ||
7351a482 SW |
1058 | /* TODO: do we need to consider the outgoing interface for |
1059 | * coded packets? | |
1060 | */ | |
1061 | router_neigh = batadv_orig_router_get(neigh_node->orig_node, | |
1062 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1063 | if (!router_neigh) |
1064 | goto out; | |
1065 | ||
89652331 SW |
1066 | router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh, |
1067 | BATADV_IF_DEFAULT); | |
1068 | if (!router_neigh_ifinfo) | |
1069 | goto out; | |
1070 | ||
3c12de9a | 1071 | neigh_tmp = nc_packet->neigh_node; |
7351a482 SW |
1072 | router_coding = batadv_orig_router_get(neigh_tmp->orig_node, |
1073 | BATADV_IF_DEFAULT); | |
3c12de9a MH |
1074 | if (!router_coding) |
1075 | goto out; | |
1076 | ||
89652331 SW |
1077 | router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding, |
1078 | BATADV_IF_DEFAULT); | |
1079 | if (!router_coding_ifinfo) | |
1080 | goto out; | |
1081 | ||
1082 | tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg; | |
1083 | tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp); | |
1084 | tq_tmp = router_coding_ifinfo->bat_iv.tq_avg; | |
1085 | tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp); | |
3c12de9a MH |
1086 | |
1087 | /* Select one destination for the MAC-header dst-field based on | |
1088 | * weighted TQ-values. | |
1089 | */ | |
1090 | if (tq_weighted_neigh >= tq_weighted_coding) { | |
1091 | /* Destination from nc_packet is selected for MAC-header */ | |
1092 | first_dest = nc_packet->nc_path->next_hop; | |
1093 | first_source = nc_packet->nc_path->prev_hop; | |
1094 | second_dest = neigh_node->addr; | |
1095 | second_source = ethhdr->h_source; | |
1096 | packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1097 | packet2 = (struct batadv_unicast_packet *)skb->data; | |
1098 | packet_id1 = nc_packet->packet_id; | |
1099 | packet_id2 = batadv_skb_crc32(skb, | |
1100 | skb->data + sizeof(*packet2)); | |
1101 | } else { | |
1102 | /* Destination for skb is selected for MAC-header */ | |
1103 | first_dest = neigh_node->addr; | |
1104 | first_source = ethhdr->h_source; | |
1105 | second_dest = nc_packet->nc_path->next_hop; | |
1106 | second_source = nc_packet->nc_path->prev_hop; | |
1107 | packet1 = (struct batadv_unicast_packet *)skb->data; | |
1108 | packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data; | |
1109 | packet_id1 = batadv_skb_crc32(skb, | |
1110 | skb->data + sizeof(*packet1)); | |
1111 | packet_id2 = nc_packet->packet_id; | |
1112 | } | |
1113 | ||
1114 | /* Instead of zero padding the smallest data buffer, we | |
1115 | * code into the largest. | |
1116 | */ | |
1117 | if (skb->len <= nc_packet->skb->len) { | |
1118 | skb_dest = nc_packet->skb; | |
1119 | skb_src = skb; | |
1120 | } else { | |
1121 | skb_dest = skb; | |
1122 | skb_src = nc_packet->skb; | |
1123 | } | |
1124 | ||
1125 | /* coding_len is used when decoding the packet shorter packet */ | |
1126 | coding_len = skb_src->len - unicast_size; | |
1127 | ||
1128 | if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0) | |
1129 | goto out; | |
1130 | ||
1131 | skb_push(skb_dest, header_add); | |
1132 | ||
1133 | coded_packet = (struct batadv_coded_packet *)skb_dest->data; | |
1134 | skb_reset_mac_header(skb_dest); | |
1135 | ||
a40d9b07 SW |
1136 | coded_packet->packet_type = BATADV_CODED; |
1137 | coded_packet->version = BATADV_COMPAT_VERSION; | |
1138 | coded_packet->ttl = packet1->ttl; | |
3c12de9a MH |
1139 | |
1140 | /* Info about first unicast packet */ | |
8fdd0153 AQ |
1141 | ether_addr_copy(coded_packet->first_source, first_source); |
1142 | ether_addr_copy(coded_packet->first_orig_dest, packet1->dest); | |
3c12de9a MH |
1143 | coded_packet->first_crc = packet_id1; |
1144 | coded_packet->first_ttvn = packet1->ttvn; | |
1145 | ||
1146 | /* Info about second unicast packet */ | |
8fdd0153 AQ |
1147 | ether_addr_copy(coded_packet->second_dest, second_dest); |
1148 | ether_addr_copy(coded_packet->second_source, second_source); | |
1149 | ether_addr_copy(coded_packet->second_orig_dest, packet2->dest); | |
3c12de9a | 1150 | coded_packet->second_crc = packet_id2; |
a40d9b07 | 1151 | coded_packet->second_ttl = packet2->ttl; |
3c12de9a MH |
1152 | coded_packet->second_ttvn = packet2->ttvn; |
1153 | coded_packet->coded_len = htons(coding_len); | |
1154 | ||
1155 | /* This is where the magic happens: Code skb_src into skb_dest */ | |
1156 | batadv_nc_memxor(skb_dest->data + coded_size, | |
1157 | skb_src->data + unicast_size, coding_len); | |
1158 | ||
1159 | /* Update counters accordingly */ | |
1160 | if (BATADV_SKB_CB(skb_src)->decoded && | |
1161 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1162 | /* Both packets are recoded */ | |
1163 | count = skb_src->len + ETH_HLEN; | |
1164 | count += skb_dest->len + ETH_HLEN; | |
1165 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2); | |
1166 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count); | |
1167 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1168 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1169 | /* Both packets are newly coded */ | |
1170 | count = skb_src->len + ETH_HLEN; | |
1171 | count += skb_dest->len + ETH_HLEN; | |
1172 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2); | |
1173 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count); | |
1174 | } else if (BATADV_SKB_CB(skb_src)->decoded && | |
1175 | !BATADV_SKB_CB(skb_dest)->decoded) { | |
1176 | /* skb_src recoded and skb_dest is newly coded */ | |
1177 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1178 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1179 | skb_src->len + ETH_HLEN); | |
1180 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1181 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1182 | skb_dest->len + ETH_HLEN); | |
1183 | } else if (!BATADV_SKB_CB(skb_src)->decoded && | |
1184 | BATADV_SKB_CB(skb_dest)->decoded) { | |
1185 | /* skb_src is newly coded and skb_dest is recoded */ | |
1186 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE); | |
1187 | batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, | |
1188 | skb_src->len + ETH_HLEN); | |
1189 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE); | |
1190 | batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, | |
1191 | skb_dest->len + ETH_HLEN); | |
1192 | } | |
1193 | ||
1194 | /* skb_src is now coded into skb_dest, so free it */ | |
1195 | kfree_skb(skb_src); | |
1196 | ||
1197 | /* avoid duplicate free of skb from nc_packet */ | |
1198 | nc_packet->skb = NULL; | |
1199 | batadv_nc_packet_free(nc_packet); | |
1200 | ||
1201 | /* Send the coded packet and return true */ | |
1202 | batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest); | |
1203 | res = true; | |
1204 | out: | |
1205 | if (router_neigh) | |
1206 | batadv_neigh_node_free_ref(router_neigh); | |
1207 | if (router_coding) | |
1208 | batadv_neigh_node_free_ref(router_coding); | |
89652331 SW |
1209 | if (router_neigh_ifinfo) |
1210 | batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo); | |
1211 | if (router_coding_ifinfo) | |
1212 | batadv_neigh_ifinfo_free_ref(router_coding_ifinfo); | |
3c12de9a MH |
1213 | return res; |
1214 | } | |
1215 | ||
1216 | /** | |
1217 | * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst. | |
1218 | * @skb: data skb to forward | |
1219 | * @dst: destination mac address of the other skb to code with | |
1220 | * @src: source mac address of skb | |
1221 | * | |
1222 | * Whenever we network code a packet we have to check whether we received it in | |
1223 | * a network coded form. If so, we may not be able to use it for coding because | |
1224 | * some neighbors may also have received (overheard) the packet in the network | |
1225 | * coded form without being able to decode it. It is hard to know which of the | |
1226 | * neighboring nodes was able to decode the packet, therefore we can only | |
1227 | * re-code the packet if the source of the previous encoded packet is involved. | |
1228 | * Since the source encoded the packet we can be certain it has all necessary | |
1229 | * decode information. | |
1230 | * | |
1231 | * Returns true if coding of a decoded packet is allowed. | |
1232 | */ | |
1233 | static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, | |
1234 | uint8_t *dst, uint8_t *src) | |
1235 | { | |
1236 | if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src)) | |
1237 | return false; | |
24820df1 | 1238 | return true; |
3c12de9a MH |
1239 | } |
1240 | ||
1241 | /** | |
1242 | * batadv_nc_path_search - Find the coding path matching in_nc_node and | |
1243 | * out_nc_node to retrieve a buffered packet that can be used for coding. | |
1244 | * @bat_priv: the bat priv with all the soft interface information | |
1245 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1246 | * @out_nc_node: pointer to skb source's neighbor nc node | |
1247 | * @skb: data skb to forward | |
1248 | * @eth_dst: next hop mac address of skb | |
1249 | * | |
1250 | * Returns true if coding of a decoded skb is allowed. | |
1251 | */ | |
1252 | static struct batadv_nc_packet * | |
1253 | batadv_nc_path_search(struct batadv_priv *bat_priv, | |
1254 | struct batadv_nc_node *in_nc_node, | |
1255 | struct batadv_nc_node *out_nc_node, | |
1256 | struct sk_buff *skb, | |
1257 | uint8_t *eth_dst) | |
1258 | { | |
1259 | struct batadv_nc_path *nc_path, nc_path_key; | |
1260 | struct batadv_nc_packet *nc_packet_out = NULL; | |
1261 | struct batadv_nc_packet *nc_packet, *nc_packet_tmp; | |
1262 | struct batadv_hashtable *hash = bat_priv->nc.coding_hash; | |
1263 | int idx; | |
1264 | ||
1265 | if (!hash) | |
1266 | return NULL; | |
1267 | ||
1268 | /* Create almost path key */ | |
1269 | batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr, | |
1270 | out_nc_node->addr); | |
1271 | idx = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1272 | ||
1273 | /* Check for coding opportunities in this nc_path */ | |
1274 | rcu_read_lock(); | |
1275 | hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) { | |
1276 | if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr)) | |
1277 | continue; | |
1278 | ||
1279 | if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr)) | |
1280 | continue; | |
1281 | ||
1282 | spin_lock_bh(&nc_path->packet_list_lock); | |
1283 | if (list_empty(&nc_path->packet_list)) { | |
1284 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1285 | continue; | |
1286 | } | |
1287 | ||
1288 | list_for_each_entry_safe(nc_packet, nc_packet_tmp, | |
1289 | &nc_path->packet_list, list) { | |
1290 | if (!batadv_nc_skb_coding_possible(nc_packet->skb, | |
1291 | eth_dst, | |
1292 | in_nc_node->addr)) | |
1293 | continue; | |
1294 | ||
1295 | /* Coding opportunity is found! */ | |
1296 | list_del(&nc_packet->list); | |
1297 | nc_packet_out = nc_packet; | |
1298 | break; | |
1299 | } | |
1300 | ||
1301 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1302 | break; | |
1303 | } | |
1304 | rcu_read_unlock(); | |
1305 | ||
1306 | return nc_packet_out; | |
1307 | } | |
1308 | ||
1309 | /** | |
1310 | * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the | |
1311 | * skb's sender (may be equal to the originator). | |
1312 | * @bat_priv: the bat priv with all the soft interface information | |
1313 | * @skb: data skb to forward | |
1314 | * @eth_dst: next hop mac address of skb | |
1315 | * @eth_src: source mac address of skb | |
1316 | * @in_nc_node: pointer to skb next hop's neighbor nc node | |
1317 | * | |
1318 | * Returns an nc packet if a suitable coding packet was found, NULL otherwise. | |
1319 | */ | |
1320 | static struct batadv_nc_packet * | |
1321 | batadv_nc_skb_src_search(struct batadv_priv *bat_priv, | |
1322 | struct sk_buff *skb, | |
1323 | uint8_t *eth_dst, | |
1324 | uint8_t *eth_src, | |
1325 | struct batadv_nc_node *in_nc_node) | |
1326 | { | |
1327 | struct batadv_orig_node *orig_node; | |
1328 | struct batadv_nc_node *out_nc_node; | |
1329 | struct batadv_nc_packet *nc_packet = NULL; | |
1330 | ||
1331 | orig_node = batadv_orig_hash_find(bat_priv, eth_src); | |
1332 | if (!orig_node) | |
1333 | return NULL; | |
1334 | ||
1335 | rcu_read_lock(); | |
1336 | list_for_each_entry_rcu(out_nc_node, | |
1337 | &orig_node->out_coding_list, list) { | |
1338 | /* Check if the skb is decoded and if recoding is possible */ | |
1339 | if (!batadv_nc_skb_coding_possible(skb, | |
1340 | out_nc_node->addr, eth_src)) | |
1341 | continue; | |
1342 | ||
1343 | /* Search for an opportunity in this nc_path */ | |
1344 | nc_packet = batadv_nc_path_search(bat_priv, in_nc_node, | |
1345 | out_nc_node, skb, eth_dst); | |
1346 | if (nc_packet) | |
1347 | break; | |
1348 | } | |
1349 | rcu_read_unlock(); | |
1350 | ||
1351 | batadv_orig_node_free_ref(orig_node); | |
1352 | return nc_packet; | |
1353 | } | |
1354 | ||
612d2b4f MH |
1355 | /** |
1356 | * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the | |
1357 | * unicast skb before it is stored for use in later decoding | |
1358 | * @bat_priv: the bat priv with all the soft interface information | |
1359 | * @skb: data skb to store | |
1360 | * @eth_dst_new: new destination mac address of skb | |
1361 | */ | |
1362 | static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, | |
1363 | struct sk_buff *skb, | |
1364 | uint8_t *eth_dst_new) | |
1365 | { | |
1366 | struct ethhdr *ethhdr; | |
1367 | ||
1368 | /* Copy skb header to change the mac header */ | |
bad93e9d | 1369 | skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
612d2b4f MH |
1370 | if (!skb) |
1371 | return; | |
1372 | ||
1373 | /* Set the mac header as if we actually sent the packet uncoded */ | |
7ed4be95 | 1374 | ethhdr = eth_hdr(skb); |
8fdd0153 AQ |
1375 | ether_addr_copy(ethhdr->h_source, ethhdr->h_dest); |
1376 | ether_addr_copy(ethhdr->h_dest, eth_dst_new); | |
612d2b4f MH |
1377 | |
1378 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1379 | skb_push(skb, ETH_HLEN); | |
1380 | ||
1381 | /* Add the packet to the decoding packet pool */ | |
1382 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1383 | ||
1384 | /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free | |
1385 | * our ref | |
1386 | */ | |
1387 | kfree_skb(skb); | |
1388 | } | |
1389 | ||
3c12de9a MH |
1390 | /** |
1391 | * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst. | |
1392 | * @skb: data skb to forward | |
1393 | * @neigh_node: next hop to forward packet to | |
1394 | * @ethhdr: pointer to the ethernet header inside the skb | |
1395 | * | |
1396 | * Loops through list of neighboring nodes the next hop has a good connection to | |
1397 | * (receives OGMs with a sufficient quality). We need to find a neighbor of our | |
1398 | * next hop that potentially sent a packet which our next hop also received | |
1399 | * (overheard) and has stored for later decoding. | |
1400 | * | |
1401 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1402 | */ | |
1403 | static bool batadv_nc_skb_dst_search(struct sk_buff *skb, | |
1404 | struct batadv_neigh_node *neigh_node, | |
1405 | struct ethhdr *ethhdr) | |
1406 | { | |
1407 | struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1408 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1409 | struct batadv_orig_node *orig_node = neigh_node->orig_node; | |
1410 | struct batadv_nc_node *nc_node; | |
1411 | struct batadv_nc_packet *nc_packet = NULL; | |
1412 | ||
1413 | rcu_read_lock(); | |
1414 | list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) { | |
1415 | /* Search for coding opportunity with this in_nc_node */ | |
1416 | nc_packet = batadv_nc_skb_src_search(bat_priv, skb, | |
1417 | neigh_node->addr, | |
1418 | ethhdr->h_source, nc_node); | |
1419 | ||
1420 | /* Opportunity was found, so stop searching */ | |
1421 | if (nc_packet) | |
1422 | break; | |
1423 | } | |
1424 | rcu_read_unlock(); | |
1425 | ||
1426 | if (!nc_packet) | |
1427 | return false; | |
1428 | ||
612d2b4f MH |
1429 | /* Save packets for later decoding */ |
1430 | batadv_nc_skb_store_before_coding(bat_priv, skb, | |
1431 | neigh_node->addr); | |
1432 | batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb, | |
1433 | nc_packet->neigh_node->addr); | |
1434 | ||
3c12de9a MH |
1435 | /* Code and send packets */ |
1436 | if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet, | |
1437 | neigh_node)) | |
1438 | return true; | |
1439 | ||
1440 | /* out of mem ? Coding failed - we have to free the buffered packet | |
1441 | * to avoid memleaks. The skb passed as argument will be dealt with | |
1442 | * by the calling function. | |
1443 | */ | |
1444 | batadv_nc_send_packet(nc_packet); | |
1445 | return false; | |
1446 | } | |
1447 | ||
95332477 MH |
1448 | /** |
1449 | * batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding | |
1450 | * @skb: skb to add to path | |
1451 | * @nc_path: path to add skb to | |
1452 | * @neigh_node: next hop to forward packet to | |
1453 | * @packet_id: checksum to identify packet | |
1454 | * | |
1455 | * Returns true if the packet was buffered or false in case of an error. | |
1456 | */ | |
1457 | static bool batadv_nc_skb_add_to_path(struct sk_buff *skb, | |
1458 | struct batadv_nc_path *nc_path, | |
1459 | struct batadv_neigh_node *neigh_node, | |
1460 | __be32 packet_id) | |
1461 | { | |
1462 | struct batadv_nc_packet *nc_packet; | |
1463 | ||
1464 | nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC); | |
1465 | if (!nc_packet) | |
1466 | return false; | |
1467 | ||
1468 | /* Initialize nc_packet */ | |
1469 | nc_packet->timestamp = jiffies; | |
1470 | nc_packet->packet_id = packet_id; | |
1471 | nc_packet->skb = skb; | |
1472 | nc_packet->neigh_node = neigh_node; | |
1473 | nc_packet->nc_path = nc_path; | |
1474 | ||
1475 | /* Add coding packet to list */ | |
1476 | spin_lock_bh(&nc_path->packet_list_lock); | |
1477 | list_add_tail(&nc_packet->list, &nc_path->packet_list); | |
1478 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1479 | ||
1480 | return true; | |
1481 | } | |
1482 | ||
1483 | /** | |
1484 | * batadv_nc_skb_forward - try to code a packet or add it to the coding packet | |
1485 | * buffer | |
1486 | * @skb: data skb to forward | |
1487 | * @neigh_node: next hop to forward packet to | |
95332477 MH |
1488 | * |
1489 | * Returns true if the skb was consumed (encoded packet sent) or false otherwise | |
1490 | */ | |
1491 | bool batadv_nc_skb_forward(struct sk_buff *skb, | |
e91ecfc6 | 1492 | struct batadv_neigh_node *neigh_node) |
95332477 MH |
1493 | { |
1494 | const struct net_device *netdev = neigh_node->if_incoming->soft_iface; | |
1495 | struct batadv_priv *bat_priv = netdev_priv(netdev); | |
1496 | struct batadv_unicast_packet *packet; | |
1497 | struct batadv_nc_path *nc_path; | |
e91ecfc6 | 1498 | struct ethhdr *ethhdr = eth_hdr(skb); |
95332477 MH |
1499 | __be32 packet_id; |
1500 | u8 *payload; | |
1501 | ||
1502 | /* Check if network coding is enabled */ | |
1503 | if (!atomic_read(&bat_priv->network_coding)) | |
1504 | goto out; | |
1505 | ||
1506 | /* We only handle unicast packets */ | |
1507 | payload = skb_network_header(skb); | |
1508 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1509 | if (packet->packet_type != BATADV_UNICAST) |
95332477 MH |
1510 | goto out; |
1511 | ||
3c12de9a MH |
1512 | /* Try to find a coding opportunity and send the skb if one is found */ |
1513 | if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr)) | |
1514 | return true; | |
1515 | ||
95332477 MH |
1516 | /* Find or create a nc_path for this src-dst pair */ |
1517 | nc_path = batadv_nc_get_path(bat_priv, | |
1518 | bat_priv->nc.coding_hash, | |
1519 | ethhdr->h_source, | |
1520 | neigh_node->addr); | |
1521 | ||
1522 | if (!nc_path) | |
1523 | goto out; | |
1524 | ||
1525 | /* Add skb to nc_path */ | |
1526 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1527 | if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id)) | |
1528 | goto free_nc_path; | |
1529 | ||
1530 | /* Packet is consumed */ | |
1531 | return true; | |
1532 | ||
1533 | free_nc_path: | |
1534 | batadv_nc_path_free_ref(nc_path); | |
1535 | out: | |
1536 | /* Packet is not consumed */ | |
1537 | return false; | |
1538 | } | |
1539 | ||
612d2b4f MH |
1540 | /** |
1541 | * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used | |
1542 | * when decoding coded packets | |
1543 | * @bat_priv: the bat priv with all the soft interface information | |
1544 | * @skb: data skb to store | |
1545 | */ | |
1546 | void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv, | |
1547 | struct sk_buff *skb) | |
1548 | { | |
1549 | struct batadv_unicast_packet *packet; | |
1550 | struct batadv_nc_path *nc_path; | |
7ed4be95 | 1551 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f MH |
1552 | __be32 packet_id; |
1553 | u8 *payload; | |
1554 | ||
1555 | /* Check if network coding is enabled */ | |
1556 | if (!atomic_read(&bat_priv->network_coding)) | |
1557 | goto out; | |
1558 | ||
1559 | /* Check for supported packet type */ | |
1560 | payload = skb_network_header(skb); | |
1561 | packet = (struct batadv_unicast_packet *)payload; | |
a40d9b07 | 1562 | if (packet->packet_type != BATADV_UNICAST) |
612d2b4f MH |
1563 | goto out; |
1564 | ||
1565 | /* Find existing nc_path or create a new */ | |
1566 | nc_path = batadv_nc_get_path(bat_priv, | |
1567 | bat_priv->nc.decoding_hash, | |
1568 | ethhdr->h_source, | |
1569 | ethhdr->h_dest); | |
1570 | ||
1571 | if (!nc_path) | |
1572 | goto out; | |
1573 | ||
1574 | /* Clone skb and adjust skb->data to point at batman header */ | |
1575 | skb = skb_clone(skb, GFP_ATOMIC); | |
1576 | if (unlikely(!skb)) | |
1577 | goto free_nc_path; | |
1578 | ||
1579 | if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) | |
1580 | goto free_skb; | |
1581 | ||
1582 | if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN))) | |
1583 | goto free_skb; | |
1584 | ||
1585 | /* Add skb to nc_path */ | |
1586 | packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet)); | |
1587 | if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id)) | |
1588 | goto free_skb; | |
1589 | ||
1590 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER); | |
1591 | return; | |
1592 | ||
1593 | free_skb: | |
1594 | kfree_skb(skb); | |
1595 | free_nc_path: | |
1596 | batadv_nc_path_free_ref(nc_path); | |
1597 | out: | |
1598 | return; | |
1599 | } | |
1600 | ||
1601 | /** | |
1602 | * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet | |
1603 | * should be saved in the decoding buffer and, if so, store it there | |
1604 | * @bat_priv: the bat priv with all the soft interface information | |
1605 | * @skb: unicast skb to store | |
1606 | */ | |
1607 | void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, | |
1608 | struct sk_buff *skb) | |
1609 | { | |
7ed4be95 | 1610 | struct ethhdr *ethhdr = eth_hdr(skb); |
612d2b4f | 1611 | |
6e0895c2 | 1612 | if (batadv_is_my_mac(bat_priv, ethhdr->h_dest)) |
612d2b4f MH |
1613 | return; |
1614 | ||
1615 | /* Set data pointer to MAC header to mimic packets from our tx path */ | |
1616 | skb_push(skb, ETH_HLEN); | |
1617 | ||
1618 | batadv_nc_skb_store_for_decoding(bat_priv, skb); | |
1619 | } | |
1620 | ||
2df5278b MH |
1621 | /** |
1622 | * batadv_nc_skb_decode_packet - decode given skb using the decode data stored | |
1623 | * in nc_packet | |
6e0895c2 | 1624 | * @bat_priv: the bat priv with all the soft interface information |
2df5278b MH |
1625 | * @skb: unicast skb to decode |
1626 | * @nc_packet: decode data needed to decode the skb | |
1627 | * | |
1628 | * Returns pointer to decoded unicast packet if the packet was decoded or NULL | |
1629 | * in case of an error. | |
1630 | */ | |
1631 | static struct batadv_unicast_packet * | |
6e0895c2 | 1632 | batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, |
2df5278b MH |
1633 | struct batadv_nc_packet *nc_packet) |
1634 | { | |
1635 | const int h_size = sizeof(struct batadv_unicast_packet); | |
1636 | const int h_diff = sizeof(struct batadv_coded_packet) - h_size; | |
1637 | struct batadv_unicast_packet *unicast_packet; | |
1638 | struct batadv_coded_packet coded_packet_tmp; | |
1639 | struct ethhdr *ethhdr, ethhdr_tmp; | |
1640 | uint8_t *orig_dest, ttl, ttvn; | |
1641 | unsigned int coding_len; | |
7da19971 | 1642 | int err; |
2df5278b MH |
1643 | |
1644 | /* Save headers temporarily */ | |
1645 | memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); | |
1646 | memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); | |
1647 | ||
1648 | if (skb_cow(skb, 0) < 0) | |
1649 | return NULL; | |
1650 | ||
1651 | if (unlikely(!skb_pull_rcsum(skb, h_diff))) | |
1652 | return NULL; | |
1653 | ||
1654 | /* Data points to batman header, so set mac header 14 bytes before | |
1655 | * and network to data | |
1656 | */ | |
1657 | skb_set_mac_header(skb, -ETH_HLEN); | |
1658 | skb_reset_network_header(skb); | |
1659 | ||
1660 | /* Reconstruct original mac header */ | |
7ed4be95 | 1661 | ethhdr = eth_hdr(skb); |
abae9479 | 1662 | *ethhdr = ethhdr_tmp; |
2df5278b MH |
1663 | |
1664 | /* Select the correct unicast header information based on the location | |
1665 | * of our mac address in the coded_packet header | |
1666 | */ | |
6e0895c2 | 1667 | if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) { |
2df5278b MH |
1668 | /* If we are the second destination the packet was overheard, |
1669 | * so the Ethernet address must be copied to h_dest and | |
1670 | * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST | |
1671 | */ | |
8fdd0153 | 1672 | ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest); |
2df5278b MH |
1673 | skb->pkt_type = PACKET_HOST; |
1674 | ||
1675 | orig_dest = coded_packet_tmp.second_orig_dest; | |
1676 | ttl = coded_packet_tmp.second_ttl; | |
1677 | ttvn = coded_packet_tmp.second_ttvn; | |
1678 | } else { | |
1679 | orig_dest = coded_packet_tmp.first_orig_dest; | |
a40d9b07 | 1680 | ttl = coded_packet_tmp.ttl; |
2df5278b MH |
1681 | ttvn = coded_packet_tmp.first_ttvn; |
1682 | } | |
1683 | ||
1684 | coding_len = ntohs(coded_packet_tmp.coded_len); | |
1685 | ||
1686 | if (coding_len > skb->len) | |
1687 | return NULL; | |
1688 | ||
1689 | /* Here the magic is reversed: | |
1690 | * extract the missing packet from the received coded packet | |
1691 | */ | |
1692 | batadv_nc_memxor(skb->data + h_size, | |
1693 | nc_packet->skb->data + h_size, | |
1694 | coding_len); | |
1695 | ||
1696 | /* Resize decoded skb if decoded with larger packet */ | |
7da19971 ML |
1697 | if (nc_packet->skb->len > coding_len + h_size) { |
1698 | err = pskb_trim_rcsum(skb, coding_len + h_size); | |
1699 | if (err) | |
1700 | return NULL; | |
1701 | } | |
2df5278b MH |
1702 | |
1703 | /* Create decoded unicast packet */ | |
1704 | unicast_packet = (struct batadv_unicast_packet *)skb->data; | |
a40d9b07 SW |
1705 | unicast_packet->packet_type = BATADV_UNICAST; |
1706 | unicast_packet->version = BATADV_COMPAT_VERSION; | |
1707 | unicast_packet->ttl = ttl; | |
8fdd0153 | 1708 | ether_addr_copy(unicast_packet->dest, orig_dest); |
2df5278b MH |
1709 | unicast_packet->ttvn = ttvn; |
1710 | ||
1711 | batadv_nc_packet_free(nc_packet); | |
1712 | return unicast_packet; | |
1713 | } | |
1714 | ||
1715 | /** | |
1716 | * batadv_nc_find_decoding_packet - search through buffered decoding data to | |
1717 | * find the data needed to decode the coded packet | |
1718 | * @bat_priv: the bat priv with all the soft interface information | |
1719 | * @ethhdr: pointer to the ethernet header inside the coded packet | |
1720 | * @coded: coded packet we try to find decode data for | |
1721 | * | |
1722 | * Returns pointer to nc packet if the needed data was found or NULL otherwise. | |
1723 | */ | |
1724 | static struct batadv_nc_packet * | |
1725 | batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, | |
1726 | struct ethhdr *ethhdr, | |
1727 | struct batadv_coded_packet *coded) | |
1728 | { | |
1729 | struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; | |
1730 | struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; | |
1731 | struct batadv_nc_path *nc_path, nc_path_key; | |
1732 | uint8_t *dest, *source; | |
1733 | __be32 packet_id; | |
1734 | int index; | |
1735 | ||
1736 | if (!hash) | |
1737 | return NULL; | |
1738 | ||
1739 | /* Select the correct packet id based on the location of our mac-addr */ | |
1740 | dest = ethhdr->h_source; | |
6e0895c2 | 1741 | if (!batadv_is_my_mac(bat_priv, coded->second_dest)) { |
2df5278b MH |
1742 | source = coded->second_source; |
1743 | packet_id = coded->second_crc; | |
1744 | } else { | |
1745 | source = coded->first_source; | |
1746 | packet_id = coded->first_crc; | |
1747 | } | |
1748 | ||
1749 | batadv_nc_hash_key_gen(&nc_path_key, source, dest); | |
1750 | index = batadv_nc_hash_choose(&nc_path_key, hash->size); | |
1751 | ||
1752 | /* Search for matching coding path */ | |
1753 | rcu_read_lock(); | |
1754 | hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { | |
1755 | /* Find matching nc_packet */ | |
1756 | spin_lock_bh(&nc_path->packet_list_lock); | |
1757 | list_for_each_entry(tmp_nc_packet, | |
1758 | &nc_path->packet_list, list) { | |
1759 | if (packet_id == tmp_nc_packet->packet_id) { | |
1760 | list_del(&tmp_nc_packet->list); | |
1761 | ||
1762 | nc_packet = tmp_nc_packet; | |
1763 | break; | |
1764 | } | |
1765 | } | |
1766 | spin_unlock_bh(&nc_path->packet_list_lock); | |
1767 | ||
1768 | if (nc_packet) | |
1769 | break; | |
1770 | } | |
1771 | rcu_read_unlock(); | |
1772 | ||
1773 | if (!nc_packet) | |
1774 | batadv_dbg(BATADV_DBG_NC, bat_priv, | |
1775 | "No decoding packet found for %u\n", packet_id); | |
1776 | ||
1777 | return nc_packet; | |
1778 | } | |
1779 | ||
1780 | /** | |
1781 | * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the | |
1782 | * resulting unicast packet | |
1783 | * @skb: incoming coded packet | |
1784 | * @recv_if: pointer to interface this packet was received on | |
1785 | */ | |
1786 | static int batadv_nc_recv_coded_packet(struct sk_buff *skb, | |
1787 | struct batadv_hard_iface *recv_if) | |
1788 | { | |
1789 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
1790 | struct batadv_unicast_packet *unicast_packet; | |
1791 | struct batadv_coded_packet *coded_packet; | |
1792 | struct batadv_nc_packet *nc_packet; | |
1793 | struct ethhdr *ethhdr; | |
1794 | int hdr_size = sizeof(*coded_packet); | |
1795 | ||
1796 | /* Check if network coding is enabled */ | |
1797 | if (!atomic_read(&bat_priv->network_coding)) | |
1798 | return NET_RX_DROP; | |
1799 | ||
1800 | /* Make sure we can access (and remove) header */ | |
1801 | if (unlikely(!pskb_may_pull(skb, hdr_size))) | |
1802 | return NET_RX_DROP; | |
1803 | ||
1804 | coded_packet = (struct batadv_coded_packet *)skb->data; | |
7ed4be95 | 1805 | ethhdr = eth_hdr(skb); |
2df5278b MH |
1806 | |
1807 | /* Verify frame is destined for us */ | |
6e0895c2 DM |
1808 | if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && |
1809 | !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) | |
2df5278b MH |
1810 | return NET_RX_DROP; |
1811 | ||
1812 | /* Update stat counter */ | |
6e0895c2 | 1813 | if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) |
2df5278b MH |
1814 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); |
1815 | ||
1816 | nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, | |
1817 | coded_packet); | |
1818 | if (!nc_packet) { | |
1819 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1820 | return NET_RX_DROP; | |
1821 | } | |
1822 | ||
1823 | /* Make skb's linear, because decoding accesses the entire buffer */ | |
1824 | if (skb_linearize(skb) < 0) | |
1825 | goto free_nc_packet; | |
1826 | ||
1827 | if (skb_linearize(nc_packet->skb) < 0) | |
1828 | goto free_nc_packet; | |
1829 | ||
1830 | /* Decode the packet */ | |
6e0895c2 | 1831 | unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet); |
2df5278b MH |
1832 | if (!unicast_packet) { |
1833 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); | |
1834 | goto free_nc_packet; | |
1835 | } | |
1836 | ||
1837 | /* Mark packet as decoded to do correct recoding when forwarding */ | |
1838 | BATADV_SKB_CB(skb)->decoded = true; | |
1839 | batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); | |
1840 | batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, | |
1841 | skb->len + ETH_HLEN); | |
1842 | return batadv_recv_unicast_packet(skb, recv_if); | |
1843 | ||
1844 | free_nc_packet: | |
1845 | batadv_nc_packet_free(nc_packet); | |
1846 | return NET_RX_DROP; | |
1847 | } | |
1848 | ||
d353d8d4 | 1849 | /** |
6c519bad | 1850 | * batadv_nc_mesh_free - clean up network coding memory |
d353d8d4 MH |
1851 | * @bat_priv: the bat priv with all the soft interface information |
1852 | */ | |
6c519bad | 1853 | void batadv_nc_mesh_free(struct batadv_priv *bat_priv) |
d353d8d4 | 1854 | { |
3f4841ff ML |
1855 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1); |
1856 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1); | |
d353d8d4 | 1857 | cancel_delayed_work_sync(&bat_priv->nc.work); |
612d2b4f | 1858 | |
95332477 MH |
1859 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); |
1860 | batadv_hash_destroy(bat_priv->nc.coding_hash); | |
612d2b4f MH |
1861 | batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL); |
1862 | batadv_hash_destroy(bat_priv->nc.decoding_hash); | |
d353d8d4 | 1863 | } |
d56b1705 MH |
1864 | |
1865 | /** | |
1866 | * batadv_nc_nodes_seq_print_text - print the nc node information | |
1867 | * @seq: seq file to print on | |
1868 | * @offset: not used | |
1869 | */ | |
1870 | int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) | |
1871 | { | |
1872 | struct net_device *net_dev = (struct net_device *)seq->private; | |
1873 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
1874 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
1875 | struct batadv_hard_iface *primary_if; | |
1876 | struct hlist_head *head; | |
1877 | struct batadv_orig_node *orig_node; | |
1878 | struct batadv_nc_node *nc_node; | |
1879 | int i; | |
1880 | ||
1881 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
1882 | if (!primary_if) | |
1883 | goto out; | |
1884 | ||
1885 | /* Traverse list of originators */ | |
1886 | for (i = 0; i < hash->size; i++) { | |
1887 | head = &hash->table[i]; | |
1888 | ||
1889 | /* For each orig_node in this bin */ | |
1890 | rcu_read_lock(); | |
1891 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { | |
aa27c312 ML |
1892 | /* no need to print the orig node if it does not have |
1893 | * network coding neighbors | |
1894 | */ | |
1895 | if (list_empty(&orig_node->in_coding_list) && | |
1896 | list_empty(&orig_node->out_coding_list)) | |
1897 | continue; | |
1898 | ||
d56b1705 MH |
1899 | seq_printf(seq, "Node: %pM\n", orig_node->orig); |
1900 | ||
0c814653 | 1901 | seq_puts(seq, " Ingoing: "); |
d56b1705 MH |
1902 | /* For each in_nc_node to this orig_node */ |
1903 | list_for_each_entry_rcu(nc_node, | |
1904 | &orig_node->in_coding_list, | |
1905 | list) | |
1906 | seq_printf(seq, "%pM ", | |
1907 | nc_node->addr); | |
0c814653 | 1908 | seq_puts(seq, "\n"); |
d56b1705 | 1909 | |
0c814653 | 1910 | seq_puts(seq, " Outgoing: "); |
d56b1705 MH |
1911 | /* For out_nc_node to this orig_node */ |
1912 | list_for_each_entry_rcu(nc_node, | |
1913 | &orig_node->out_coding_list, | |
1914 | list) | |
1915 | seq_printf(seq, "%pM ", | |
1916 | nc_node->addr); | |
0c814653 | 1917 | seq_puts(seq, "\n\n"); |
d56b1705 MH |
1918 | } |
1919 | rcu_read_unlock(); | |
1920 | } | |
1921 | ||
1922 | out: | |
1923 | if (primary_if) | |
1924 | batadv_hardif_free_ref(primary_if); | |
1925 | return 0; | |
1926 | } | |
1927 | ||
1928 | /** | |
1929 | * batadv_nc_init_debugfs - create nc folder and related files in debugfs | |
1930 | * @bat_priv: the bat priv with all the soft interface information | |
1931 | */ | |
1932 | int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) | |
1933 | { | |
1934 | struct dentry *nc_dir, *file; | |
1935 | ||
1936 | nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir); | |
1937 | if (!nc_dir) | |
1938 | goto out; | |
1939 | ||
1940 | file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir, | |
1941 | &bat_priv->nc.min_tq); | |
1942 | if (!file) | |
1943 | goto out; | |
1944 | ||
95332477 MH |
1945 | file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir, |
1946 | &bat_priv->nc.max_fwd_delay); | |
1947 | if (!file) | |
1948 | goto out; | |
1949 | ||
612d2b4f MH |
1950 | file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir, |
1951 | &bat_priv->nc.max_buffer_time); | |
1952 | if (!file) | |
1953 | goto out; | |
1954 | ||
d56b1705 MH |
1955 | return 0; |
1956 | ||
1957 | out: | |
1958 | return -ENOMEM; | |
1959 | } |