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1 | /* |
2 | * Copyright (c) 2008, 2009 open80211s Ltd. |
3 | * Author: Luis Carlos Cobo <luisca@cozybit.com> |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify |
6 | * it under the terms of the GNU General Public License version 2 as |
7 | * published by the Free Software Foundation. |
8 | */ |
9 | |
10 | #include <linux/etherdevice.h> |
11 | #include <linux/list.h> |
12 | #include <linux/random.h> |
13 | #include <linux/slab.h> |
14 | #include <linux/spinlock.h> |
15 | #include <linux/string.h> |
16 | #include <net/mac80211.h> |
17 | #include "ieee80211_i.h" |
18 | #include "mesh.h" |
19 | |
20 | /* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */ |
21 | #define INIT_PATHS_SIZE_ORDER 2 |
22 | |
23 | /* Keep the mean chain length below this constant */ |
24 | #define MEAN_CHAIN_LEN 2 |
25 | |
26 | #define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \ |
27 | time_after(jiffies, mpath->exp_time) && \ |
28 | !(mpath->flags & MESH_PATH_FIXED)) |
29 | |
30 | struct mpath_node { |
31 | struct hlist_node list; |
32 | struct rcu_head rcu; |
33 | /* This indirection allows two different tables to point to the same |
34 | * mesh_path structure, useful when resizing |
35 | */ |
36 | struct mesh_path *mpath; |
37 | }; |
38 | |
39 | static struct mesh_table *mesh_paths; |
40 | static struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */ |
41 | |
42 | int mesh_paths_generation; |
43 | static void __mesh_table_free(struct mesh_table *tbl) |
44 | { |
45 | kfree(tbl->hash_buckets); |
46 | kfree(tbl->hashwlock); |
47 | kfree(tbl); |
48 | } |
49 | |
50 | void mesh_table_free(struct mesh_table *tbl, bool free_leafs) |
51 | { |
52 | struct hlist_head *mesh_hash; |
53 | struct hlist_node *p, *q; |
54 | int i; |
55 | |
56 | mesh_hash = tbl->hash_buckets; |
57 | for (i = 0; i <= tbl->hash_mask; i++) { |
58 | spin_lock(&tbl->hashwlock[i]); |
59 | hlist_for_each_safe(p, q, &mesh_hash[i]) { |
60 | tbl->free_node(p, free_leafs); |
61 | atomic_dec(&tbl->entries); |
62 | } |
63 | spin_unlock(&tbl->hashwlock[i]); |
64 | } |
65 | __mesh_table_free(tbl); |
66 | } |
67 | |
68 | static struct mesh_table *mesh_table_grow(struct mesh_table *tbl) |
69 | { |
70 | struct mesh_table *newtbl; |
71 | struct hlist_head *oldhash; |
72 | struct hlist_node *p, *q; |
73 | int i; |
74 | |
75 | if (atomic_read(&tbl->entries) |
76 | < tbl->mean_chain_len * (tbl->hash_mask + 1)) |
77 | goto endgrow; |
78 | |
79 | newtbl = mesh_table_alloc(tbl->size_order + 1); |
80 | if (!newtbl) |
81 | goto endgrow; |
82 | |
83 | newtbl->free_node = tbl->free_node; |
84 | newtbl->mean_chain_len = tbl->mean_chain_len; |
85 | newtbl->copy_node = tbl->copy_node; |
86 | atomic_set(&newtbl->entries, atomic_read(&tbl->entries)); |
87 | |
88 | oldhash = tbl->hash_buckets; |
89 | for (i = 0; i <= tbl->hash_mask; i++) |
90 | hlist_for_each(p, &oldhash[i]) |
91 | if (tbl->copy_node(p, newtbl) < 0) |
92 | goto errcopy; |
93 | |
94 | return newtbl; |
95 | |
96 | errcopy: |
97 | for (i = 0; i <= newtbl->hash_mask; i++) { |
98 | hlist_for_each_safe(p, q, &newtbl->hash_buckets[i]) |
99 | tbl->free_node(p, 0); |
100 | } |
101 | __mesh_table_free(newtbl); |
102 | endgrow: |
103 | return NULL; |
104 | } |
105 | |
106 | |
107 | /* This lock will have the grow table function as writer and add / delete nodes |
108 | * as readers. When reading the table (i.e. doing lookups) we are well protected |
109 | * by RCU |
110 | */ |
111 | static DEFINE_RWLOCK(pathtbl_resize_lock); |
112 | |
113 | /** |
114 | * |
115 | * mesh_path_assign_nexthop - update mesh path next hop |
116 | * |
117 | * @mpath: mesh path to update |
118 | * @sta: next hop to assign |
119 | * |
120 | * Locking: mpath->state_lock must be held when calling this function |
121 | */ |
122 | void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta) |
123 | { |
124 | struct sk_buff *skb; |
125 | struct ieee80211_hdr *hdr; |
126 | struct sk_buff_head tmpq; |
127 | unsigned long flags; |
128 | |
129 | rcu_assign_pointer(mpath->next_hop, sta); |
130 | |
131 | __skb_queue_head_init(&tmpq); |
132 | |
133 | spin_lock_irqsave(&mpath->frame_queue.lock, flags); |
134 | |
135 | while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) { |
136 | hdr = (struct ieee80211_hdr *) skb->data; |
137 | memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN); |
138 | __skb_queue_tail(&tmpq, skb); |
139 | } |
140 | |
141 | skb_queue_splice(&tmpq, &mpath->frame_queue); |
142 | spin_unlock_irqrestore(&mpath->frame_queue.lock, flags); |
143 | } |
144 | |
145 | |
146 | /** |
147 | * mesh_path_lookup - look up a path in the mesh path table |
148 | * @dst: hardware address (ETH_ALEN length) of destination |
149 | * @sdata: local subif |
150 | * |
151 | * Returns: pointer to the mesh path structure, or NULL if not found |
152 | * |
153 | * Locking: must be called within a read rcu section. |
154 | */ |
155 | struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) |
156 | { |
157 | struct mesh_path *mpath; |
158 | struct hlist_node *n; |
159 | struct hlist_head *bucket; |
160 | struct mesh_table *tbl; |
161 | struct mpath_node *node; |
162 | |
163 | tbl = rcu_dereference(mesh_paths); |
164 | |
165 | bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)]; |
166 | hlist_for_each_entry_rcu(node, n, bucket, list) { |
167 | mpath = node->mpath; |
168 | if (mpath->sdata == sdata && |
169 | memcmp(dst, mpath->dst, ETH_ALEN) == 0) { |
170 | if (MPATH_EXPIRED(mpath)) { |
171 | spin_lock_bh(&mpath->state_lock); |
172 | if (MPATH_EXPIRED(mpath)) |
173 | mpath->flags &= ~MESH_PATH_ACTIVE; |
174 | spin_unlock_bh(&mpath->state_lock); |
175 | } |
176 | return mpath; |
177 | } |
178 | } |
179 | return NULL; |
180 | } |
181 | |
182 | struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) |
183 | { |
184 | struct mesh_path *mpath; |
185 | struct hlist_node *n; |
186 | struct hlist_head *bucket; |
187 | struct mesh_table *tbl; |
188 | struct mpath_node *node; |
189 | |
190 | tbl = rcu_dereference(mpp_paths); |
191 | |
192 | bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)]; |
193 | hlist_for_each_entry_rcu(node, n, bucket, list) { |
194 | mpath = node->mpath; |
195 | if (mpath->sdata == sdata && |
196 | memcmp(dst, mpath->dst, ETH_ALEN) == 0) { |
197 | if (MPATH_EXPIRED(mpath)) { |
198 | spin_lock_bh(&mpath->state_lock); |
199 | if (MPATH_EXPIRED(mpath)) |
200 | mpath->flags &= ~MESH_PATH_ACTIVE; |
201 | spin_unlock_bh(&mpath->state_lock); |
202 | } |
203 | return mpath; |
204 | } |
205 | } |
206 | return NULL; |
207 | } |
208 | |
209 | |
210 | /** |
211 | * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index |
212 | * @idx: index |
213 | * @sdata: local subif, or NULL for all entries |
214 | * |
215 | * Returns: pointer to the mesh path structure, or NULL if not found. |
216 | * |
217 | * Locking: must be called within a read rcu section. |
218 | */ |
219 | struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data *sdata) |
220 | { |
221 | struct mpath_node *node; |
222 | struct hlist_node *p; |
223 | int i; |
224 | int j = 0; |
225 | |
226 | for_each_mesh_entry(mesh_paths, p, node, i) { |
227 | if (sdata && node->mpath->sdata != sdata) |
228 | continue; |
229 | if (j++ == idx) { |
230 | if (MPATH_EXPIRED(node->mpath)) { |
231 | spin_lock_bh(&node->mpath->state_lock); |
232 | if (MPATH_EXPIRED(node->mpath)) |
233 | node->mpath->flags &= ~MESH_PATH_ACTIVE; |
234 | spin_unlock_bh(&node->mpath->state_lock); |
235 | } |
236 | return node->mpath; |
237 | } |
238 | } |
239 | |
240 | return NULL; |
241 | } |
242 | |
243 | /** |
244 | * mesh_path_add - allocate and add a new path to the mesh path table |
245 | * @addr: destination address of the path (ETH_ALEN length) |
246 | * @sdata: local subif |
247 | * |
248 | * Returns: 0 on success |
249 | * |
250 | * State: the initial state of the new path is set to 0 |
251 | */ |
252 | int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata) |
253 | { |
254 | struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; |
255 | struct ieee80211_local *local = sdata->local; |
256 | struct mesh_path *mpath, *new_mpath; |
257 | struct mpath_node *node, *new_node; |
258 | struct hlist_head *bucket; |
259 | struct hlist_node *n; |
260 | int grow = 0; |
261 | int err = 0; |
262 | u32 hash_idx; |
263 | |
264 | if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0) |
265 | /* never add ourselves as neighbours */ |
266 | return -ENOTSUPP; |
267 | |
268 | if (is_multicast_ether_addr(dst)) |
269 | return -ENOTSUPP; |
270 | |
271 | if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0) |
272 | return -ENOSPC; |
273 | |
274 | err = -ENOMEM; |
275 | new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC); |
276 | if (!new_mpath) |
277 | goto err_path_alloc; |
278 | |
279 | new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); |
280 | if (!new_node) |
281 | goto err_node_alloc; |
282 | |
283 | read_lock(&pathtbl_resize_lock); |
284 | memcpy(new_mpath->dst, dst, ETH_ALEN); |
285 | new_mpath->sdata = sdata; |
286 | new_mpath->flags = 0; |
287 | skb_queue_head_init(&new_mpath->frame_queue); |
288 | new_node->mpath = new_mpath; |
289 | new_mpath->timer.data = (unsigned long) new_mpath; |
290 | new_mpath->timer.function = mesh_path_timer; |
291 | new_mpath->exp_time = jiffies; |
292 | spin_lock_init(&new_mpath->state_lock); |
293 | init_timer(&new_mpath->timer); |
294 | |
295 | hash_idx = mesh_table_hash(dst, sdata, mesh_paths); |
296 | bucket = &mesh_paths->hash_buckets[hash_idx]; |
297 | |
298 | spin_lock(&mesh_paths->hashwlock[hash_idx]); |
299 | |
300 | err = -EEXIST; |
301 | hlist_for_each_entry(node, n, bucket, list) { |
302 | mpath = node->mpath; |
303 | if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0) |
304 | goto err_exists; |
305 | } |
306 | |
307 | hlist_add_head_rcu(&new_node->list, bucket); |
308 | if (atomic_inc_return(&mesh_paths->entries) >= |
309 | mesh_paths->mean_chain_len * (mesh_paths->hash_mask + 1)) |
310 | grow = 1; |
311 | |
312 | mesh_paths_generation++; |
313 | |
314 | spin_unlock(&mesh_paths->hashwlock[hash_idx]); |
315 | read_unlock(&pathtbl_resize_lock); |
316 | if (grow) { |
317 | set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags); |
318 | ieee80211_queue_work(&local->hw, &ifmsh->work); |
319 | } |
320 | return 0; |
321 | |
322 | err_exists: |
323 | spin_unlock(&mesh_paths->hashwlock[hash_idx]); |
324 | read_unlock(&pathtbl_resize_lock); |
325 | kfree(new_node); |
326 | err_node_alloc: |
327 | kfree(new_mpath); |
328 | err_path_alloc: |
329 | atomic_dec(&sdata->u.mesh.mpaths); |
330 | return err; |
331 | } |
332 | |
333 | void mesh_mpath_table_grow(void) |
334 | { |
335 | struct mesh_table *oldtbl, *newtbl; |
336 | |
337 | write_lock(&pathtbl_resize_lock); |
338 | oldtbl = mesh_paths; |
339 | newtbl = mesh_table_grow(mesh_paths); |
340 | if (!newtbl) { |
341 | write_unlock(&pathtbl_resize_lock); |
342 | return; |
343 | } |
344 | rcu_assign_pointer(mesh_paths, newtbl); |
345 | write_unlock(&pathtbl_resize_lock); |
346 | |
347 | synchronize_rcu(); |
348 | mesh_table_free(oldtbl, false); |
349 | } |
350 | |
351 | void mesh_mpp_table_grow(void) |
352 | { |
353 | struct mesh_table *oldtbl, *newtbl; |
354 | |
355 | write_lock(&pathtbl_resize_lock); |
356 | oldtbl = mpp_paths; |
357 | newtbl = mesh_table_grow(mpp_paths); |
358 | if (!newtbl) { |
359 | write_unlock(&pathtbl_resize_lock); |
360 | return; |
361 | } |
362 | rcu_assign_pointer(mpp_paths, newtbl); |
363 | write_unlock(&pathtbl_resize_lock); |
364 | |
365 | synchronize_rcu(); |
366 | mesh_table_free(oldtbl, false); |
367 | } |
368 | |
369 | int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata) |
370 | { |
371 | struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; |
372 | struct ieee80211_local *local = sdata->local; |
373 | struct mesh_path *mpath, *new_mpath; |
374 | struct mpath_node *node, *new_node; |
375 | struct hlist_head *bucket; |
376 | struct hlist_node *n; |
377 | int grow = 0; |
378 | int err = 0; |
379 | u32 hash_idx; |
380 | |
381 | if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0) |
382 | /* never add ourselves as neighbours */ |
383 | return -ENOTSUPP; |
384 | |
385 | if (is_multicast_ether_addr(dst)) |
386 | return -ENOTSUPP; |
387 | |
388 | err = -ENOMEM; |
389 | new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC); |
390 | if (!new_mpath) |
391 | goto err_path_alloc; |
392 | |
393 | new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); |
394 | if (!new_node) |
395 | goto err_node_alloc; |
396 | |
397 | read_lock(&pathtbl_resize_lock); |
398 | memcpy(new_mpath->dst, dst, ETH_ALEN); |
399 | memcpy(new_mpath->mpp, mpp, ETH_ALEN); |
400 | new_mpath->sdata = sdata; |
401 | new_mpath->flags = 0; |
402 | skb_queue_head_init(&new_mpath->frame_queue); |
403 | new_node->mpath = new_mpath; |
404 | new_mpath->exp_time = jiffies; |
405 | spin_lock_init(&new_mpath->state_lock); |
406 | |
407 | hash_idx = mesh_table_hash(dst, sdata, mpp_paths); |
408 | bucket = &mpp_paths->hash_buckets[hash_idx]; |
409 | |
410 | spin_lock(&mpp_paths->hashwlock[hash_idx]); |
411 | |
412 | err = -EEXIST; |
413 | hlist_for_each_entry(node, n, bucket, list) { |
414 | mpath = node->mpath; |
415 | if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0) |
416 | goto err_exists; |
417 | } |
418 | |
419 | hlist_add_head_rcu(&new_node->list, bucket); |
420 | if (atomic_inc_return(&mpp_paths->entries) >= |
421 | mpp_paths->mean_chain_len * (mpp_paths->hash_mask + 1)) |
422 | grow = 1; |
423 | |
424 | spin_unlock(&mpp_paths->hashwlock[hash_idx]); |
425 | read_unlock(&pathtbl_resize_lock); |
426 | if (grow) { |
427 | set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags); |
428 | ieee80211_queue_work(&local->hw, &ifmsh->work); |
429 | } |
430 | return 0; |
431 | |
432 | err_exists: |
433 | spin_unlock(&mpp_paths->hashwlock[hash_idx]); |
434 | read_unlock(&pathtbl_resize_lock); |
435 | kfree(new_node); |
436 | err_node_alloc: |
437 | kfree(new_mpath); |
438 | err_path_alloc: |
439 | return err; |
440 | } |
441 | |
442 | |
443 | /** |
444 | * mesh_plink_broken - deactivates paths and sends perr when a link breaks |
445 | * |
446 | * @sta: broken peer link |
447 | * |
448 | * This function must be called from the rate control algorithm if enough |
449 | * delivery errors suggest that a peer link is no longer usable. |
450 | */ |
451 | void mesh_plink_broken(struct sta_info *sta) |
452 | { |
453 | static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; |
454 | struct mesh_path *mpath; |
455 | struct mpath_node *node; |
456 | struct hlist_node *p; |
457 | struct ieee80211_sub_if_data *sdata = sta->sdata; |
458 | int i; |
459 | |
460 | rcu_read_lock(); |
461 | for_each_mesh_entry(mesh_paths, p, node, i) { |
462 | mpath = node->mpath; |
463 | spin_lock_bh(&mpath->state_lock); |
464 | if (mpath->next_hop == sta && |
465 | mpath->flags & MESH_PATH_ACTIVE && |
466 | !(mpath->flags & MESH_PATH_FIXED)) { |
467 | mpath->flags &= ~MESH_PATH_ACTIVE; |
468 | ++mpath->sn; |
469 | spin_unlock_bh(&mpath->state_lock); |
470 | mesh_path_error_tx(MESH_TTL, mpath->dst, |
471 | cpu_to_le32(mpath->sn), |
472 | cpu_to_le16(PERR_RCODE_DEST_UNREACH), |
473 | bcast, sdata); |
474 | } else |
475 | spin_unlock_bh(&mpath->state_lock); |
476 | } |
477 | rcu_read_unlock(); |
478 | } |
479 | |
480 | /** |
481 | * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches |
482 | * |
483 | * @sta - mesh peer to match |
484 | * |
485 | * RCU notes: this function is called when a mesh plink transitions from |
486 | * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that |
487 | * allows path creation. This will happen before the sta can be freed (because |
488 | * sta_info_destroy() calls this) so any reader in a rcu read block will be |
489 | * protected against the plink disappearing. |
490 | */ |
491 | void mesh_path_flush_by_nexthop(struct sta_info *sta) |
492 | { |
493 | struct mesh_path *mpath; |
494 | struct mpath_node *node; |
495 | struct hlist_node *p; |
496 | int i; |
497 | |
498 | for_each_mesh_entry(mesh_paths, p, node, i) { |
499 | mpath = node->mpath; |
500 | if (mpath->next_hop == sta) |
501 | mesh_path_del(mpath->dst, mpath->sdata); |
502 | } |
503 | } |
504 | |
505 | void mesh_path_flush(struct ieee80211_sub_if_data *sdata) |
506 | { |
507 | struct mesh_path *mpath; |
508 | struct mpath_node *node; |
509 | struct hlist_node *p; |
510 | int i; |
511 | |
512 | for_each_mesh_entry(mesh_paths, p, node, i) { |
513 | mpath = node->mpath; |
514 | if (mpath->sdata == sdata) |
515 | mesh_path_del(mpath->dst, mpath->sdata); |
516 | } |
517 | } |
518 | |
519 | static void mesh_path_node_reclaim(struct rcu_head *rp) |
520 | { |
521 | struct mpath_node *node = container_of(rp, struct mpath_node, rcu); |
522 | struct ieee80211_sub_if_data *sdata = node->mpath->sdata; |
523 | |
524 | del_timer_sync(&node->mpath->timer); |
525 | atomic_dec(&sdata->u.mesh.mpaths); |
526 | kfree(node->mpath); |
527 | kfree(node); |
528 | } |
529 | |
530 | /** |
531 | * mesh_path_del - delete a mesh path from the table |
532 | * |
533 | * @addr: dst address (ETH_ALEN length) |
534 | * @sdata: local subif |
535 | * |
536 | * Returns: 0 if successful |
537 | */ |
538 | int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata) |
539 | { |
540 | struct mesh_path *mpath; |
541 | struct mpath_node *node; |
542 | struct hlist_head *bucket; |
543 | struct hlist_node *n; |
544 | int hash_idx; |
545 | int err = 0; |
546 | |
547 | read_lock(&pathtbl_resize_lock); |
548 | hash_idx = mesh_table_hash(addr, sdata, mesh_paths); |
549 | bucket = &mesh_paths->hash_buckets[hash_idx]; |
550 | |
551 | spin_lock(&mesh_paths->hashwlock[hash_idx]); |
552 | hlist_for_each_entry(node, n, bucket, list) { |
553 | mpath = node->mpath; |
554 | if (mpath->sdata == sdata && |
555 | memcmp(addr, mpath->dst, ETH_ALEN) == 0) { |
556 | spin_lock_bh(&mpath->state_lock); |
557 | mpath->flags |= MESH_PATH_RESOLVING; |
558 | hlist_del_rcu(&node->list); |
559 | call_rcu(&node->rcu, mesh_path_node_reclaim); |
560 | atomic_dec(&mesh_paths->entries); |
561 | spin_unlock_bh(&mpath->state_lock); |
562 | goto enddel; |
563 | } |
564 | } |
565 | |
566 | err = -ENXIO; |
567 | enddel: |
568 | mesh_paths_generation++; |
569 | spin_unlock(&mesh_paths->hashwlock[hash_idx]); |
570 | read_unlock(&pathtbl_resize_lock); |
571 | return err; |
572 | } |
573 | |
574 | /** |
575 | * mesh_path_tx_pending - sends pending frames in a mesh path queue |
576 | * |
577 | * @mpath: mesh path to activate |
578 | * |
579 | * Locking: the state_lock of the mpath structure must NOT be held when calling |
580 | * this function. |
581 | */ |
582 | void mesh_path_tx_pending(struct mesh_path *mpath) |
583 | { |
584 | if (mpath->flags & MESH_PATH_ACTIVE) |
585 | ieee80211_add_pending_skbs(mpath->sdata->local, |
586 | &mpath->frame_queue); |
587 | } |
588 | |
589 | /** |
590 | * mesh_path_discard_frame - discard a frame whose path could not be resolved |
591 | * |
592 | * @skb: frame to discard |
593 | * @sdata: network subif the frame was to be sent through |
594 | * |
595 | * If the frame was being forwarded from another MP, a PERR frame will be sent |
596 | * to the precursor. The precursor's address (i.e. the previous hop) was saved |
597 | * in addr1 of the frame-to-be-forwarded, and would only be overwritten once |
598 | * the destination is successfully resolved. |
599 | * |
600 | * Locking: the function must me called within a rcu_read_lock region |
601 | */ |
602 | void mesh_path_discard_frame(struct sk_buff *skb, |
603 | struct ieee80211_sub_if_data *sdata) |
604 | { |
605 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
606 | struct mesh_path *mpath; |
607 | u32 sn = 0; |
608 | |
609 | if (memcmp(hdr->addr4, sdata->vif.addr, ETH_ALEN) != 0) { |
610 | u8 *ra, *da; |
611 | |
612 | da = hdr->addr3; |
613 | ra = hdr->addr1; |
614 | mpath = mesh_path_lookup(da, sdata); |
615 | if (mpath) |
616 | sn = ++mpath->sn; |
617 | mesh_path_error_tx(MESH_TTL, skb->data, cpu_to_le32(sn), |
618 | cpu_to_le16(PERR_RCODE_NO_ROUTE), ra, sdata); |
619 | } |
620 | |
621 | kfree_skb(skb); |
622 | sdata->u.mesh.mshstats.dropped_frames_no_route++; |
623 | } |
624 | |
625 | /** |
626 | * mesh_path_flush_pending - free the pending queue of a mesh path |
627 | * |
628 | * @mpath: mesh path whose queue has to be freed |
629 | * |
630 | * Locking: the function must me called withing a rcu_read_lock region |
631 | */ |
632 | void mesh_path_flush_pending(struct mesh_path *mpath) |
633 | { |
634 | struct sk_buff *skb; |
635 | |
636 | while ((skb = skb_dequeue(&mpath->frame_queue)) && |
637 | (mpath->flags & MESH_PATH_ACTIVE)) |
638 | mesh_path_discard_frame(skb, mpath->sdata); |
639 | } |
640 | |
641 | /** |
642 | * mesh_path_fix_nexthop - force a specific next hop for a mesh path |
643 | * |
644 | * @mpath: the mesh path to modify |
645 | * @next_hop: the next hop to force |
646 | * |
647 | * Locking: this function must be called holding mpath->state_lock |
648 | */ |
649 | void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop) |
650 | { |
651 | spin_lock_bh(&mpath->state_lock); |
652 | mesh_path_assign_nexthop(mpath, next_hop); |
653 | mpath->sn = 0xffff; |
654 | mpath->metric = 0; |
655 | mpath->hop_count = 0; |
656 | mpath->exp_time = 0; |
657 | mpath->flags |= MESH_PATH_FIXED; |
658 | mesh_path_activate(mpath); |
659 | spin_unlock_bh(&mpath->state_lock); |
660 | mesh_path_tx_pending(mpath); |
661 | } |
662 | |
663 | static void mesh_path_node_free(struct hlist_node *p, bool free_leafs) |
664 | { |
665 | struct mesh_path *mpath; |
666 | struct mpath_node *node = hlist_entry(p, struct mpath_node, list); |
667 | mpath = node->mpath; |
668 | hlist_del_rcu(p); |
669 | if (free_leafs) |
670 | kfree(mpath); |
671 | kfree(node); |
672 | } |
673 | |
674 | static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl) |
675 | { |
676 | struct mesh_path *mpath; |
677 | struct mpath_node *node, *new_node; |
678 | u32 hash_idx; |
679 | |
680 | new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); |
681 | if (new_node == NULL) |
682 | return -ENOMEM; |
683 | |
684 | node = hlist_entry(p, struct mpath_node, list); |
685 | mpath = node->mpath; |
686 | new_node->mpath = mpath; |
687 | hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl); |
688 | hlist_add_head(&new_node->list, |
689 | &newtbl->hash_buckets[hash_idx]); |
690 | return 0; |
691 | } |
692 | |
693 | int mesh_pathtbl_init(void) |
694 | { |
695 | mesh_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER); |
696 | if (!mesh_paths) |
697 | return -ENOMEM; |
698 | mesh_paths->free_node = &mesh_path_node_free; |
699 | mesh_paths->copy_node = &mesh_path_node_copy; |
700 | mesh_paths->mean_chain_len = MEAN_CHAIN_LEN; |
701 | |
702 | mpp_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER); |
703 | if (!mpp_paths) { |
704 | mesh_table_free(mesh_paths, true); |
705 | return -ENOMEM; |
706 | } |
707 | mpp_paths->free_node = &mesh_path_node_free; |
708 | mpp_paths->copy_node = &mesh_path_node_copy; |
709 | mpp_paths->mean_chain_len = MEAN_CHAIN_LEN; |
710 | |
711 | return 0; |
712 | } |
713 | |
714 | void mesh_path_expire(struct ieee80211_sub_if_data *sdata) |
715 | { |
716 | struct mesh_path *mpath; |
717 | struct mpath_node *node; |
718 | struct hlist_node *p; |
719 | int i; |
720 | |
721 | read_lock(&pathtbl_resize_lock); |
722 | for_each_mesh_entry(mesh_paths, p, node, i) { |
723 | if (node->mpath->sdata != sdata) |
724 | continue; |
725 | mpath = node->mpath; |
726 | spin_lock_bh(&mpath->state_lock); |
727 | if ((!(mpath->flags & MESH_PATH_RESOLVING)) && |
728 | (!(mpath->flags & MESH_PATH_FIXED)) && |
729 | time_after(jiffies, |
730 | mpath->exp_time + MESH_PATH_EXPIRE)) { |
731 | spin_unlock_bh(&mpath->state_lock); |
732 | mesh_path_del(mpath->dst, mpath->sdata); |
733 | } else |
734 | spin_unlock_bh(&mpath->state_lock); |
735 | } |
736 | read_unlock(&pathtbl_resize_lock); |
737 | } |
738 | |
739 | void mesh_pathtbl_unregister(void) |
740 | { |
741 | mesh_table_free(mesh_paths, true); |
742 | mesh_table_free(mpp_paths, true); |
743 | } |
744 |
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Tags:
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v2.6.34-rc5
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