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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 "wme.h"
18#include "ieee80211_i.h"
19#include "mesh.h"
20
21static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
22
23static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
24{
25 /* Use last four bytes of hw addr as hash index */
26 return jhash_1word(*(u32 *)(addr+2), seed);
27}
28
29static const struct rhashtable_params mesh_rht_params = {
30 .nelem_hint = 2,
31 .automatic_shrinking = true,
32 .key_len = ETH_ALEN,
33 .key_offset = offsetof(struct mesh_path, dst),
34 .head_offset = offsetof(struct mesh_path, rhash),
35 .hashfn = mesh_table_hash,
36};
37
38static inline bool mpath_expired(struct mesh_path *mpath)
39{
40 return (mpath->flags & MESH_PATH_ACTIVE) &&
41 time_after(jiffies, mpath->exp_time) &&
42 !(mpath->flags & MESH_PATH_FIXED);
43}
44
45static void mesh_path_rht_free(void *ptr, void *tblptr)
46{
47 struct mesh_path *mpath = ptr;
48 struct mesh_table *tbl = tblptr;
49
50 mesh_path_free_rcu(tbl, mpath);
51}
52
53static struct mesh_table *mesh_table_alloc(void)
54{
55 struct mesh_table *newtbl;
56
57 newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
58 if (!newtbl)
59 return NULL;
60
61 INIT_HLIST_HEAD(&newtbl->known_gates);
62 atomic_set(&newtbl->entries, 0);
63 spin_lock_init(&newtbl->gates_lock);
64
65 return newtbl;
66}
67
68static void mesh_table_free(struct mesh_table *tbl)
69{
70 rhashtable_free_and_destroy(&tbl->rhead,
71 mesh_path_rht_free, tbl);
72 kfree(tbl);
73}
74
75/**
76 *
77 * mesh_path_assign_nexthop - update mesh path next hop
78 *
79 * @mpath: mesh path to update
80 * @sta: next hop to assign
81 *
82 * Locking: mpath->state_lock must be held when calling this function
83 */
84void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
85{
86 struct sk_buff *skb;
87 struct ieee80211_hdr *hdr;
88 unsigned long flags;
89
90 rcu_assign_pointer(mpath->next_hop, sta);
91
92 spin_lock_irqsave(&mpath->frame_queue.lock, flags);
93 skb_queue_walk(&mpath->frame_queue, skb) {
94 hdr = (struct ieee80211_hdr *) skb->data;
95 memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
96 memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
97 ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
98 }
99
100 spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
101}
102
103static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
104 struct mesh_path *gate_mpath)
105{
106 struct ieee80211_hdr *hdr;
107 struct ieee80211s_hdr *mshdr;
108 int mesh_hdrlen, hdrlen;
109 char *next_hop;
110
111 hdr = (struct ieee80211_hdr *) skb->data;
112 hdrlen = ieee80211_hdrlen(hdr->frame_control);
113 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
114
115 if (!(mshdr->flags & MESH_FLAGS_AE)) {
116 /* size of the fixed part of the mesh header */
117 mesh_hdrlen = 6;
118
119 /* make room for the two extended addresses */
120 skb_push(skb, 2 * ETH_ALEN);
121 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
122
123 hdr = (struct ieee80211_hdr *) skb->data;
124
125 /* we preserve the previous mesh header and only add
126 * the new addreses */
127 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
128 mshdr->flags = MESH_FLAGS_AE_A5_A6;
129 memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
130 memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
131 }
132
133 /* update next hop */
134 hdr = (struct ieee80211_hdr *) skb->data;
135 rcu_read_lock();
136 next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
137 memcpy(hdr->addr1, next_hop, ETH_ALEN);
138 rcu_read_unlock();
139 memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
140 memcpy(hdr->addr3, dst_addr, ETH_ALEN);
141}
142
143/**
144 *
145 * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
146 *
147 * This function is used to transfer or copy frames from an unresolved mpath to
148 * a gate mpath. The function also adds the Address Extension field and
149 * updates the next hop.
150 *
151 * If a frame already has an Address Extension field, only the next hop and
152 * destination addresses are updated.
153 *
154 * The gate mpath must be an active mpath with a valid mpath->next_hop.
155 *
156 * @mpath: An active mpath the frames will be sent to (i.e. the gate)
157 * @from_mpath: The failed mpath
158 * @copy: When true, copy all the frames to the new mpath queue. When false,
159 * move them.
160 */
161static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
162 struct mesh_path *from_mpath,
163 bool copy)
164{
165 struct sk_buff *skb, *fskb, *tmp;
166 struct sk_buff_head failq;
167 unsigned long flags;
168
169 if (WARN_ON(gate_mpath == from_mpath))
170 return;
171 if (WARN_ON(!gate_mpath->next_hop))
172 return;
173
174 __skb_queue_head_init(&failq);
175
176 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
177 skb_queue_splice_init(&from_mpath->frame_queue, &failq);
178 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
179
180 skb_queue_walk_safe(&failq, fskb, tmp) {
181 if (skb_queue_len(&gate_mpath->frame_queue) >=
182 MESH_FRAME_QUEUE_LEN) {
183 mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
184 break;
185 }
186
187 skb = skb_copy(fskb, GFP_ATOMIC);
188 if (WARN_ON(!skb))
189 break;
190
191 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
192 skb_queue_tail(&gate_mpath->frame_queue, skb);
193
194 if (copy)
195 continue;
196
197 __skb_unlink(fskb, &failq);
198 kfree_skb(fskb);
199 }
200
201 mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
202 gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
203
204 if (!copy)
205 return;
206
207 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
208 skb_queue_splice(&failq, &from_mpath->frame_queue);
209 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
210}
211
212
213static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
214 struct ieee80211_sub_if_data *sdata)
215{
216 struct mesh_path *mpath;
217
218 mpath = rhashtable_lookup_fast(&tbl->rhead, dst, mesh_rht_params);
219
220 if (mpath && mpath_expired(mpath)) {
221 spin_lock_bh(&mpath->state_lock);
222 mpath->flags &= ~MESH_PATH_ACTIVE;
223 spin_unlock_bh(&mpath->state_lock);
224 }
225 return mpath;
226}
227
228/**
229 * mesh_path_lookup - look up a path in the mesh path table
230 * @sdata: local subif
231 * @dst: hardware address (ETH_ALEN length) of destination
232 *
233 * Returns: pointer to the mesh path structure, or NULL if not found
234 *
235 * Locking: must be called within a read rcu section.
236 */
237struct mesh_path *
238mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
239{
240 return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata);
241}
242
243struct mesh_path *
244mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
245{
246 return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
247}
248
249static struct mesh_path *
250__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
251{
252 int i = 0, ret;
253 struct mesh_path *mpath = NULL;
254 struct rhashtable_iter iter;
255
256 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
257 if (ret)
258 return NULL;
259
260 ret = rhashtable_walk_start(&iter);
261 if (ret && ret != -EAGAIN)
262 goto err;
263
264 while ((mpath = rhashtable_walk_next(&iter))) {
265 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
266 continue;
267 if (IS_ERR(mpath))
268 break;
269 if (i++ == idx)
270 break;
271 }
272err:
273 rhashtable_walk_stop(&iter);
274 rhashtable_walk_exit(&iter);
275
276 if (IS_ERR(mpath) || !mpath)
277 return NULL;
278
279 if (mpath_expired(mpath)) {
280 spin_lock_bh(&mpath->state_lock);
281 mpath->flags &= ~MESH_PATH_ACTIVE;
282 spin_unlock_bh(&mpath->state_lock);
283 }
284 return mpath;
285}
286
287/**
288 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
289 * @idx: index
290 * @sdata: local subif, or NULL for all entries
291 *
292 * Returns: pointer to the mesh path structure, or NULL if not found.
293 *
294 * Locking: must be called within a read rcu section.
295 */
296struct mesh_path *
297mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
298{
299 return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
300}
301
302/**
303 * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
304 * @idx: index
305 * @sdata: local subif, or NULL for all entries
306 *
307 * Returns: pointer to the proxy path structure, or NULL if not found.
308 *
309 * Locking: must be called within a read rcu section.
310 */
311struct mesh_path *
312mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
313{
314 return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
315}
316
317/**
318 * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
319 * @mpath: gate path to add to table
320 */
321int mesh_path_add_gate(struct mesh_path *mpath)
322{
323 struct mesh_table *tbl;
324 int err;
325
326 rcu_read_lock();
327 tbl = mpath->sdata->u.mesh.mesh_paths;
328
329 spin_lock_bh(&mpath->state_lock);
330 if (mpath->is_gate) {
331 err = -EEXIST;
332 spin_unlock_bh(&mpath->state_lock);
333 goto err_rcu;
334 }
335 mpath->is_gate = true;
336 mpath->sdata->u.mesh.num_gates++;
337
338 spin_lock(&tbl->gates_lock);
339 hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
340 spin_unlock(&tbl->gates_lock);
341
342 spin_unlock_bh(&mpath->state_lock);
343
344 mpath_dbg(mpath->sdata,
345 "Mesh path: Recorded new gate: %pM. %d known gates\n",
346 mpath->dst, mpath->sdata->u.mesh.num_gates);
347 err = 0;
348err_rcu:
349 rcu_read_unlock();
350 return err;
351}
352
353/**
354 * mesh_gate_del - remove a mesh gate from the list of known gates
355 * @tbl: table which holds our list of known gates
356 * @mpath: gate mpath
357 */
358static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
359{
360 lockdep_assert_held(&mpath->state_lock);
361 if (!mpath->is_gate)
362 return;
363
364 mpath->is_gate = false;
365 spin_lock_bh(&tbl->gates_lock);
366 hlist_del_rcu(&mpath->gate_list);
367 mpath->sdata->u.mesh.num_gates--;
368 spin_unlock_bh(&tbl->gates_lock);
369
370 mpath_dbg(mpath->sdata,
371 "Mesh path: Deleted gate: %pM. %d known gates\n",
372 mpath->dst, mpath->sdata->u.mesh.num_gates);
373}
374
375/**
376 * mesh_gate_num - number of gates known to this interface
377 * @sdata: subif data
378 */
379int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
380{
381 return sdata->u.mesh.num_gates;
382}
383
384static
385struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
386 const u8 *dst, gfp_t gfp_flags)
387{
388 struct mesh_path *new_mpath;
389
390 new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
391 if (!new_mpath)
392 return NULL;
393
394 memcpy(new_mpath->dst, dst, ETH_ALEN);
395 eth_broadcast_addr(new_mpath->rann_snd_addr);
396 new_mpath->is_root = false;
397 new_mpath->sdata = sdata;
398 new_mpath->flags = 0;
399 skb_queue_head_init(&new_mpath->frame_queue);
400 new_mpath->timer.data = (unsigned long) new_mpath;
401 new_mpath->timer.function = mesh_path_timer;
402 new_mpath->exp_time = jiffies;
403 spin_lock_init(&new_mpath->state_lock);
404 init_timer(&new_mpath->timer);
405
406 return new_mpath;
407}
408
409/**
410 * mesh_path_add - allocate and add a new path to the mesh path table
411 * @dst: destination address of the path (ETH_ALEN length)
412 * @sdata: local subif
413 *
414 * Returns: 0 on success
415 *
416 * State: the initial state of the new path is set to 0
417 */
418struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
419 const u8 *dst)
420{
421 struct mesh_table *tbl;
422 struct mesh_path *mpath, *new_mpath;
423 int ret;
424
425 if (ether_addr_equal(dst, sdata->vif.addr))
426 /* never add ourselves as neighbours */
427 return ERR_PTR(-ENOTSUPP);
428
429 if (is_multicast_ether_addr(dst))
430 return ERR_PTR(-ENOTSUPP);
431
432 if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
433 return ERR_PTR(-ENOSPC);
434
435 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
436 if (!new_mpath)
437 return ERR_PTR(-ENOMEM);
438
439 tbl = sdata->u.mesh.mesh_paths;
440 do {
441 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
442 &new_mpath->rhash,
443 mesh_rht_params);
444
445 if (ret == -EEXIST)
446 mpath = rhashtable_lookup_fast(&tbl->rhead,
447 dst,
448 mesh_rht_params);
449
450 } while (unlikely(ret == -EEXIST && !mpath));
451
452 if (ret && ret != -EEXIST)
453 return ERR_PTR(ret);
454
455 /* At this point either new_mpath was added, or we found a
456 * matching entry already in the table; in the latter case
457 * free the unnecessary new entry.
458 */
459 if (ret == -EEXIST) {
460 kfree(new_mpath);
461 new_mpath = mpath;
462 }
463 sdata->u.mesh.mesh_paths_generation++;
464 return new_mpath;
465}
466
467int mpp_path_add(struct ieee80211_sub_if_data *sdata,
468 const u8 *dst, const u8 *mpp)
469{
470 struct mesh_table *tbl;
471 struct mesh_path *new_mpath;
472 int ret;
473
474 if (ether_addr_equal(dst, sdata->vif.addr))
475 /* never add ourselves as neighbours */
476 return -ENOTSUPP;
477
478 if (is_multicast_ether_addr(dst))
479 return -ENOTSUPP;
480
481 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
482
483 if (!new_mpath)
484 return -ENOMEM;
485
486 memcpy(new_mpath->mpp, mpp, ETH_ALEN);
487 tbl = sdata->u.mesh.mpp_paths;
488 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
489 &new_mpath->rhash,
490 mesh_rht_params);
491
492 sdata->u.mesh.mpp_paths_generation++;
493 return ret;
494}
495
496
497/**
498 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
499 *
500 * @sta: broken peer link
501 *
502 * This function must be called from the rate control algorithm if enough
503 * delivery errors suggest that a peer link is no longer usable.
504 */
505void mesh_plink_broken(struct sta_info *sta)
506{
507 struct ieee80211_sub_if_data *sdata = sta->sdata;
508 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
509 static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
510 struct mesh_path *mpath;
511 struct rhashtable_iter iter;
512 int ret;
513
514 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
515 if (ret)
516 return;
517
518 ret = rhashtable_walk_start(&iter);
519 if (ret && ret != -EAGAIN)
520 goto out;
521
522 while ((mpath = rhashtable_walk_next(&iter))) {
523 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
524 continue;
525 if (IS_ERR(mpath))
526 break;
527 if (rcu_access_pointer(mpath->next_hop) == sta &&
528 mpath->flags & MESH_PATH_ACTIVE &&
529 !(mpath->flags & MESH_PATH_FIXED)) {
530 spin_lock_bh(&mpath->state_lock);
531 mpath->flags &= ~MESH_PATH_ACTIVE;
532 ++mpath->sn;
533 spin_unlock_bh(&mpath->state_lock);
534 mesh_path_error_tx(sdata,
535 sdata->u.mesh.mshcfg.element_ttl,
536 mpath->dst, mpath->sn,
537 WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
538 }
539 }
540out:
541 rhashtable_walk_stop(&iter);
542 rhashtable_walk_exit(&iter);
543}
544
545static void mesh_path_free_rcu(struct mesh_table *tbl,
546 struct mesh_path *mpath)
547{
548 struct ieee80211_sub_if_data *sdata = mpath->sdata;
549
550 spin_lock_bh(&mpath->state_lock);
551 mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
552 mesh_gate_del(tbl, mpath);
553 spin_unlock_bh(&mpath->state_lock);
554 del_timer_sync(&mpath->timer);
555 atomic_dec(&sdata->u.mesh.mpaths);
556 atomic_dec(&tbl->entries);
557 kfree_rcu(mpath, rcu);
558}
559
560static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
561{
562 rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
563 mesh_path_free_rcu(tbl, mpath);
564}
565
566/**
567 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
568 *
569 * @sta: mesh peer to match
570 *
571 * RCU notes: this function is called when a mesh plink transitions from
572 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
573 * allows path creation. This will happen before the sta can be freed (because
574 * sta_info_destroy() calls this) so any reader in a rcu read block will be
575 * protected against the plink disappearing.
576 */
577void mesh_path_flush_by_nexthop(struct sta_info *sta)
578{
579 struct ieee80211_sub_if_data *sdata = sta->sdata;
580 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
581 struct mesh_path *mpath;
582 struct rhashtable_iter iter;
583 int ret;
584
585 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
586 if (ret)
587 return;
588
589 ret = rhashtable_walk_start(&iter);
590 if (ret && ret != -EAGAIN)
591 goto out;
592
593 while ((mpath = rhashtable_walk_next(&iter))) {
594 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
595 continue;
596 if (IS_ERR(mpath))
597 break;
598
599 if (rcu_access_pointer(mpath->next_hop) == sta)
600 __mesh_path_del(tbl, mpath);
601 }
602out:
603 rhashtable_walk_stop(&iter);
604 rhashtable_walk_exit(&iter);
605}
606
607static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
608 const u8 *proxy)
609{
610 struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
611 struct mesh_path *mpath;
612 struct rhashtable_iter iter;
613 int ret;
614
615 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
616 if (ret)
617 return;
618
619 ret = rhashtable_walk_start(&iter);
620 if (ret && ret != -EAGAIN)
621 goto out;
622
623 while ((mpath = rhashtable_walk_next(&iter))) {
624 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
625 continue;
626 if (IS_ERR(mpath))
627 break;
628
629 if (ether_addr_equal(mpath->mpp, proxy))
630 __mesh_path_del(tbl, mpath);
631 }
632out:
633 rhashtable_walk_stop(&iter);
634 rhashtable_walk_exit(&iter);
635}
636
637static void table_flush_by_iface(struct mesh_table *tbl)
638{
639 struct mesh_path *mpath;
640 struct rhashtable_iter iter;
641 int ret;
642
643 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
644 if (ret)
645 return;
646
647 ret = rhashtable_walk_start(&iter);
648 if (ret && ret != -EAGAIN)
649 goto out;
650
651 while ((mpath = rhashtable_walk_next(&iter))) {
652 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
653 continue;
654 if (IS_ERR(mpath))
655 break;
656 __mesh_path_del(tbl, mpath);
657 }
658out:
659 rhashtable_walk_stop(&iter);
660 rhashtable_walk_exit(&iter);
661}
662
663/**
664 * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
665 *
666 * This function deletes both mesh paths as well as mesh portal paths.
667 *
668 * @sdata: interface data to match
669 *
670 */
671void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
672{
673 table_flush_by_iface(sdata->u.mesh.mesh_paths);
674 table_flush_by_iface(sdata->u.mesh.mpp_paths);
675}
676
677/**
678 * table_path_del - delete a path from the mesh or mpp table
679 *
680 * @tbl: mesh or mpp path table
681 * @sdata: local subif
682 * @addr: dst address (ETH_ALEN length)
683 *
684 * Returns: 0 if successful
685 */
686static int table_path_del(struct mesh_table *tbl,
687 struct ieee80211_sub_if_data *sdata,
688 const u8 *addr)
689{
690 struct mesh_path *mpath;
691
692 rcu_read_lock();
693 mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
694 if (!mpath) {
695 rcu_read_unlock();
696 return -ENXIO;
697 }
698
699 __mesh_path_del(tbl, mpath);
700 rcu_read_unlock();
701 return 0;
702}
703
704
705/**
706 * mesh_path_del - delete a mesh path from the table
707 *
708 * @addr: dst address (ETH_ALEN length)
709 * @sdata: local subif
710 *
711 * Returns: 0 if successful
712 */
713int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
714{
715 int err;
716
717 /* flush relevant mpp entries first */
718 mpp_flush_by_proxy(sdata, addr);
719
720 err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
721 sdata->u.mesh.mesh_paths_generation++;
722 return err;
723}
724
725/**
726 * mesh_path_tx_pending - sends pending frames in a mesh path queue
727 *
728 * @mpath: mesh path to activate
729 *
730 * Locking: the state_lock of the mpath structure must NOT be held when calling
731 * this function.
732 */
733void mesh_path_tx_pending(struct mesh_path *mpath)
734{
735 if (mpath->flags & MESH_PATH_ACTIVE)
736 ieee80211_add_pending_skbs(mpath->sdata->local,
737 &mpath->frame_queue);
738}
739
740/**
741 * mesh_path_send_to_gates - sends pending frames to all known mesh gates
742 *
743 * @mpath: mesh path whose queue will be emptied
744 *
745 * If there is only one gate, the frames are transferred from the failed mpath
746 * queue to that gate's queue. If there are more than one gates, the frames
747 * are copied from each gate to the next. After frames are copied, the
748 * mpath queues are emptied onto the transmission queue.
749 */
750int mesh_path_send_to_gates(struct mesh_path *mpath)
751{
752 struct ieee80211_sub_if_data *sdata = mpath->sdata;
753 struct mesh_table *tbl;
754 struct mesh_path *from_mpath = mpath;
755 struct mesh_path *gate;
756 bool copy = false;
757
758 tbl = sdata->u.mesh.mesh_paths;
759
760 rcu_read_lock();
761 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
762 if (gate->flags & MESH_PATH_ACTIVE) {
763 mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
764 mesh_path_move_to_queue(gate, from_mpath, copy);
765 from_mpath = gate;
766 copy = true;
767 } else {
768 mpath_dbg(sdata,
769 "Not forwarding to %pM (flags %#x)\n",
770 gate->dst, gate->flags);
771 }
772 }
773
774 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
775 mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
776 mesh_path_tx_pending(gate);
777 }
778 rcu_read_unlock();
779
780 return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
781}
782
783/**
784 * mesh_path_discard_frame - discard a frame whose path could not be resolved
785 *
786 * @skb: frame to discard
787 * @sdata: network subif the frame was to be sent through
788 *
789 * Locking: the function must me called within a rcu_read_lock region
790 */
791void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
792 struct sk_buff *skb)
793{
794 kfree_skb(skb);
795 sdata->u.mesh.mshstats.dropped_frames_no_route++;
796}
797
798/**
799 * mesh_path_flush_pending - free the pending queue of a mesh path
800 *
801 * @mpath: mesh path whose queue has to be freed
802 *
803 * Locking: the function must me called within a rcu_read_lock region
804 */
805void mesh_path_flush_pending(struct mesh_path *mpath)
806{
807 struct sk_buff *skb;
808
809 while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
810 mesh_path_discard_frame(mpath->sdata, skb);
811}
812
813/**
814 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
815 *
816 * @mpath: the mesh path to modify
817 * @next_hop: the next hop to force
818 *
819 * Locking: this function must be called holding mpath->state_lock
820 */
821void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
822{
823 spin_lock_bh(&mpath->state_lock);
824 mesh_path_assign_nexthop(mpath, next_hop);
825 mpath->sn = 0xffff;
826 mpath->metric = 0;
827 mpath->hop_count = 0;
828 mpath->exp_time = 0;
829 mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;
830 mesh_path_activate(mpath);
831 spin_unlock_bh(&mpath->state_lock);
832 mesh_path_tx_pending(mpath);
833}
834
835int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
836{
837 struct mesh_table *tbl_path, *tbl_mpp;
838 int ret;
839
840 tbl_path = mesh_table_alloc();
841 if (!tbl_path)
842 return -ENOMEM;
843
844 tbl_mpp = mesh_table_alloc();
845 if (!tbl_mpp) {
846 ret = -ENOMEM;
847 goto free_path;
848 }
849
850 rhashtable_init(&tbl_path->rhead, &mesh_rht_params);
851 rhashtable_init(&tbl_mpp->rhead, &mesh_rht_params);
852
853 sdata->u.mesh.mesh_paths = tbl_path;
854 sdata->u.mesh.mpp_paths = tbl_mpp;
855
856 return 0;
857
858free_path:
859 mesh_table_free(tbl_path);
860 return ret;
861}
862
863static
864void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
865 struct mesh_table *tbl)
866{
867 struct mesh_path *mpath;
868 struct rhashtable_iter iter;
869 int ret;
870
871 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL);
872 if (ret)
873 return;
874
875 ret = rhashtable_walk_start(&iter);
876 if (ret && ret != -EAGAIN)
877 goto out;
878
879 while ((mpath = rhashtable_walk_next(&iter))) {
880 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
881 continue;
882 if (IS_ERR(mpath))
883 break;
884 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
885 (!(mpath->flags & MESH_PATH_FIXED)) &&
886 time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
887 __mesh_path_del(tbl, mpath);
888 }
889out:
890 rhashtable_walk_stop(&iter);
891 rhashtable_walk_exit(&iter);
892}
893
894void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
895{
896 mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
897 mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
898}
899
900void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
901{
902 mesh_table_free(sdata->u.mesh.mesh_paths);
903 mesh_table_free(sdata->u.mesh.mpp_paths);
904}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Author: Luis Carlos Cobo <luisca@cozybit.com>
5 */
6
7#include <linux/etherdevice.h>
8#include <linux/list.h>
9#include <linux/random.h>
10#include <linux/slab.h>
11#include <linux/spinlock.h>
12#include <linux/string.h>
13#include <net/mac80211.h>
14#include "wme.h"
15#include "ieee80211_i.h"
16#include "mesh.h"
17
18static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
19
20static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
21{
22 /* Use last four bytes of hw addr as hash index */
23 return jhash_1word(__get_unaligned_cpu32((u8 *)addr + 2), seed);
24}
25
26static const struct rhashtable_params mesh_rht_params = {
27 .nelem_hint = 2,
28 .automatic_shrinking = true,
29 .key_len = ETH_ALEN,
30 .key_offset = offsetof(struct mesh_path, dst),
31 .head_offset = offsetof(struct mesh_path, rhash),
32 .hashfn = mesh_table_hash,
33};
34
35static inline bool mpath_expired(struct mesh_path *mpath)
36{
37 return (mpath->flags & MESH_PATH_ACTIVE) &&
38 time_after(jiffies, mpath->exp_time) &&
39 !(mpath->flags & MESH_PATH_FIXED);
40}
41
42static void mesh_path_rht_free(void *ptr, void *tblptr)
43{
44 struct mesh_path *mpath = ptr;
45 struct mesh_table *tbl = tblptr;
46
47 mesh_path_free_rcu(tbl, mpath);
48}
49
50static struct mesh_table *mesh_table_alloc(void)
51{
52 struct mesh_table *newtbl;
53
54 newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
55 if (!newtbl)
56 return NULL;
57
58 INIT_HLIST_HEAD(&newtbl->known_gates);
59 INIT_HLIST_HEAD(&newtbl->walk_head);
60 atomic_set(&newtbl->entries, 0);
61 spin_lock_init(&newtbl->gates_lock);
62 spin_lock_init(&newtbl->walk_lock);
63 if (rhashtable_init(&newtbl->rhead, &mesh_rht_params)) {
64 kfree(newtbl);
65 return NULL;
66 }
67
68 return newtbl;
69}
70
71static void mesh_table_free(struct mesh_table *tbl)
72{
73 rhashtable_free_and_destroy(&tbl->rhead,
74 mesh_path_rht_free, tbl);
75 kfree(tbl);
76}
77
78/**
79 * mesh_path_assign_nexthop - update mesh path next hop
80 *
81 * @mpath: mesh path to update
82 * @sta: next hop to assign
83 *
84 * Locking: mpath->state_lock must be held when calling this function
85 */
86void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
87{
88 struct sk_buff *skb;
89 struct ieee80211_hdr *hdr;
90 unsigned long flags;
91
92 rcu_assign_pointer(mpath->next_hop, sta);
93
94 spin_lock_irqsave(&mpath->frame_queue.lock, flags);
95 skb_queue_walk(&mpath->frame_queue, skb) {
96 hdr = (struct ieee80211_hdr *) skb->data;
97 memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
98 memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
99 ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
100 }
101
102 spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
103}
104
105static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
106 struct mesh_path *gate_mpath)
107{
108 struct ieee80211_hdr *hdr;
109 struct ieee80211s_hdr *mshdr;
110 int mesh_hdrlen, hdrlen;
111 char *next_hop;
112
113 hdr = (struct ieee80211_hdr *) skb->data;
114 hdrlen = ieee80211_hdrlen(hdr->frame_control);
115 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
116
117 if (!(mshdr->flags & MESH_FLAGS_AE)) {
118 /* size of the fixed part of the mesh header */
119 mesh_hdrlen = 6;
120
121 /* make room for the two extended addresses */
122 skb_push(skb, 2 * ETH_ALEN);
123 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
124
125 hdr = (struct ieee80211_hdr *) skb->data;
126
127 /* we preserve the previous mesh header and only add
128 * the new addresses */
129 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
130 mshdr->flags = MESH_FLAGS_AE_A5_A6;
131 memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
132 memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
133 }
134
135 /* update next hop */
136 hdr = (struct ieee80211_hdr *) skb->data;
137 rcu_read_lock();
138 next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
139 memcpy(hdr->addr1, next_hop, ETH_ALEN);
140 rcu_read_unlock();
141 memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
142 memcpy(hdr->addr3, dst_addr, ETH_ALEN);
143}
144
145/**
146 * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
147 *
148 * This function is used to transfer or copy frames from an unresolved mpath to
149 * a gate mpath. The function also adds the Address Extension field and
150 * updates the next hop.
151 *
152 * If a frame already has an Address Extension field, only the next hop and
153 * destination addresses are updated.
154 *
155 * The gate mpath must be an active mpath with a valid mpath->next_hop.
156 *
157 * @gate_mpath: An active mpath the frames will be sent to (i.e. the gate)
158 * @from_mpath: The failed mpath
159 * @copy: When true, copy all the frames to the new mpath queue. When false,
160 * move them.
161 */
162static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
163 struct mesh_path *from_mpath,
164 bool copy)
165{
166 struct sk_buff *skb, *fskb, *tmp;
167 struct sk_buff_head failq;
168 unsigned long flags;
169
170 if (WARN_ON(gate_mpath == from_mpath))
171 return;
172 if (WARN_ON(!gate_mpath->next_hop))
173 return;
174
175 __skb_queue_head_init(&failq);
176
177 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
178 skb_queue_splice_init(&from_mpath->frame_queue, &failq);
179 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
180
181 skb_queue_walk_safe(&failq, fskb, tmp) {
182 if (skb_queue_len(&gate_mpath->frame_queue) >=
183 MESH_FRAME_QUEUE_LEN) {
184 mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
185 break;
186 }
187
188 skb = skb_copy(fskb, GFP_ATOMIC);
189 if (WARN_ON(!skb))
190 break;
191
192 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
193 skb_queue_tail(&gate_mpath->frame_queue, skb);
194
195 if (copy)
196 continue;
197
198 __skb_unlink(fskb, &failq);
199 kfree_skb(fskb);
200 }
201
202 mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
203 gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
204
205 if (!copy)
206 return;
207
208 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
209 skb_queue_splice(&failq, &from_mpath->frame_queue);
210 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
211}
212
213
214static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
215 struct ieee80211_sub_if_data *sdata)
216{
217 struct mesh_path *mpath;
218
219 mpath = rhashtable_lookup(&tbl->rhead, dst, mesh_rht_params);
220
221 if (mpath && mpath_expired(mpath)) {
222 spin_lock_bh(&mpath->state_lock);
223 mpath->flags &= ~MESH_PATH_ACTIVE;
224 spin_unlock_bh(&mpath->state_lock);
225 }
226 return mpath;
227}
228
229/**
230 * mesh_path_lookup - look up a path in the mesh path table
231 * @sdata: local subif
232 * @dst: hardware address (ETH_ALEN length) of destination
233 *
234 * Returns: pointer to the mesh path structure, or NULL if not found
235 *
236 * Locking: must be called within a read rcu section.
237 */
238struct mesh_path *
239mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
240{
241 return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata);
242}
243
244struct mesh_path *
245mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
246{
247 return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
248}
249
250static struct mesh_path *
251__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
252{
253 int i = 0;
254 struct mesh_path *mpath;
255
256 hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
257 if (i++ == idx)
258 break;
259 }
260
261 if (!mpath)
262 return NULL;
263
264 if (mpath_expired(mpath)) {
265 spin_lock_bh(&mpath->state_lock);
266 mpath->flags &= ~MESH_PATH_ACTIVE;
267 spin_unlock_bh(&mpath->state_lock);
268 }
269 return mpath;
270}
271
272/**
273 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
274 * @idx: index
275 * @sdata: local subif, or NULL for all entries
276 *
277 * Returns: pointer to the mesh path structure, or NULL if not found.
278 *
279 * Locking: must be called within a read rcu section.
280 */
281struct mesh_path *
282mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
283{
284 return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
285}
286
287/**
288 * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
289 * @idx: index
290 * @sdata: local subif, or NULL for all entries
291 *
292 * Returns: pointer to the proxy path structure, or NULL if not found.
293 *
294 * Locking: must be called within a read rcu section.
295 */
296struct mesh_path *
297mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
298{
299 return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
300}
301
302/**
303 * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
304 * @mpath: gate path to add to table
305 */
306int mesh_path_add_gate(struct mesh_path *mpath)
307{
308 struct mesh_table *tbl;
309 int err;
310
311 rcu_read_lock();
312 tbl = mpath->sdata->u.mesh.mesh_paths;
313
314 spin_lock_bh(&mpath->state_lock);
315 if (mpath->is_gate) {
316 err = -EEXIST;
317 spin_unlock_bh(&mpath->state_lock);
318 goto err_rcu;
319 }
320 mpath->is_gate = true;
321 mpath->sdata->u.mesh.num_gates++;
322
323 spin_lock(&tbl->gates_lock);
324 hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
325 spin_unlock(&tbl->gates_lock);
326
327 spin_unlock_bh(&mpath->state_lock);
328
329 mpath_dbg(mpath->sdata,
330 "Mesh path: Recorded new gate: %pM. %d known gates\n",
331 mpath->dst, mpath->sdata->u.mesh.num_gates);
332 err = 0;
333err_rcu:
334 rcu_read_unlock();
335 return err;
336}
337
338/**
339 * mesh_gate_del - remove a mesh gate from the list of known gates
340 * @tbl: table which holds our list of known gates
341 * @mpath: gate mpath
342 */
343static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
344{
345 lockdep_assert_held(&mpath->state_lock);
346 if (!mpath->is_gate)
347 return;
348
349 mpath->is_gate = false;
350 spin_lock_bh(&tbl->gates_lock);
351 hlist_del_rcu(&mpath->gate_list);
352 mpath->sdata->u.mesh.num_gates--;
353 spin_unlock_bh(&tbl->gates_lock);
354
355 mpath_dbg(mpath->sdata,
356 "Mesh path: Deleted gate: %pM. %d known gates\n",
357 mpath->dst, mpath->sdata->u.mesh.num_gates);
358}
359
360/**
361 * mesh_gate_num - number of gates known to this interface
362 * @sdata: subif data
363 */
364int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
365{
366 return sdata->u.mesh.num_gates;
367}
368
369static
370struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
371 const u8 *dst, gfp_t gfp_flags)
372{
373 struct mesh_path *new_mpath;
374
375 new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
376 if (!new_mpath)
377 return NULL;
378
379 memcpy(new_mpath->dst, dst, ETH_ALEN);
380 eth_broadcast_addr(new_mpath->rann_snd_addr);
381 new_mpath->is_root = false;
382 new_mpath->sdata = sdata;
383 new_mpath->flags = 0;
384 skb_queue_head_init(&new_mpath->frame_queue);
385 new_mpath->exp_time = jiffies;
386 spin_lock_init(&new_mpath->state_lock);
387 timer_setup(&new_mpath->timer, mesh_path_timer, 0);
388
389 return new_mpath;
390}
391
392/**
393 * mesh_path_add - allocate and add a new path to the mesh path table
394 * @dst: destination address of the path (ETH_ALEN length)
395 * @sdata: local subif
396 *
397 * Returns: 0 on success
398 *
399 * State: the initial state of the new path is set to 0
400 */
401struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
402 const u8 *dst)
403{
404 struct mesh_table *tbl;
405 struct mesh_path *mpath, *new_mpath;
406
407 if (ether_addr_equal(dst, sdata->vif.addr))
408 /* never add ourselves as neighbours */
409 return ERR_PTR(-ENOTSUPP);
410
411 if (is_multicast_ether_addr(dst))
412 return ERR_PTR(-ENOTSUPP);
413
414 if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
415 return ERR_PTR(-ENOSPC);
416
417 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
418 if (!new_mpath)
419 return ERR_PTR(-ENOMEM);
420
421 tbl = sdata->u.mesh.mesh_paths;
422 spin_lock_bh(&tbl->walk_lock);
423 mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead,
424 &new_mpath->rhash,
425 mesh_rht_params);
426 if (!mpath)
427 hlist_add_head(&new_mpath->walk_list, &tbl->walk_head);
428 spin_unlock_bh(&tbl->walk_lock);
429
430 if (mpath) {
431 kfree(new_mpath);
432
433 if (IS_ERR(mpath))
434 return mpath;
435
436 new_mpath = mpath;
437 }
438
439 sdata->u.mesh.mesh_paths_generation++;
440 return new_mpath;
441}
442
443int mpp_path_add(struct ieee80211_sub_if_data *sdata,
444 const u8 *dst, const u8 *mpp)
445{
446 struct mesh_table *tbl;
447 struct mesh_path *new_mpath;
448 int ret;
449
450 if (ether_addr_equal(dst, sdata->vif.addr))
451 /* never add ourselves as neighbours */
452 return -ENOTSUPP;
453
454 if (is_multicast_ether_addr(dst))
455 return -ENOTSUPP;
456
457 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
458
459 if (!new_mpath)
460 return -ENOMEM;
461
462 memcpy(new_mpath->mpp, mpp, ETH_ALEN);
463 tbl = sdata->u.mesh.mpp_paths;
464
465 spin_lock_bh(&tbl->walk_lock);
466 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
467 &new_mpath->rhash,
468 mesh_rht_params);
469 if (!ret)
470 hlist_add_head_rcu(&new_mpath->walk_list, &tbl->walk_head);
471 spin_unlock_bh(&tbl->walk_lock);
472
473 if (ret)
474 kfree(new_mpath);
475
476 sdata->u.mesh.mpp_paths_generation++;
477 return ret;
478}
479
480
481/**
482 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
483 *
484 * @sta: broken peer link
485 *
486 * This function must be called from the rate control algorithm if enough
487 * delivery errors suggest that a peer link is no longer usable.
488 */
489void mesh_plink_broken(struct sta_info *sta)
490{
491 struct ieee80211_sub_if_data *sdata = sta->sdata;
492 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
493 static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
494 struct mesh_path *mpath;
495
496 rcu_read_lock();
497 hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
498 if (rcu_access_pointer(mpath->next_hop) == sta &&
499 mpath->flags & MESH_PATH_ACTIVE &&
500 !(mpath->flags & MESH_PATH_FIXED)) {
501 spin_lock_bh(&mpath->state_lock);
502 mpath->flags &= ~MESH_PATH_ACTIVE;
503 ++mpath->sn;
504 spin_unlock_bh(&mpath->state_lock);
505 mesh_path_error_tx(sdata,
506 sdata->u.mesh.mshcfg.element_ttl,
507 mpath->dst, mpath->sn,
508 WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
509 }
510 }
511 rcu_read_unlock();
512}
513
514static void mesh_path_free_rcu(struct mesh_table *tbl,
515 struct mesh_path *mpath)
516{
517 struct ieee80211_sub_if_data *sdata = mpath->sdata;
518
519 spin_lock_bh(&mpath->state_lock);
520 mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
521 mesh_gate_del(tbl, mpath);
522 spin_unlock_bh(&mpath->state_lock);
523 del_timer_sync(&mpath->timer);
524 atomic_dec(&sdata->u.mesh.mpaths);
525 atomic_dec(&tbl->entries);
526 mesh_path_flush_pending(mpath);
527 kfree_rcu(mpath, rcu);
528}
529
530static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
531{
532 hlist_del_rcu(&mpath->walk_list);
533 rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
534 mesh_path_free_rcu(tbl, mpath);
535}
536
537/**
538 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
539 *
540 * @sta: mesh peer to match
541 *
542 * RCU notes: this function is called when a mesh plink transitions from
543 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
544 * allows path creation. This will happen before the sta can be freed (because
545 * sta_info_destroy() calls this) so any reader in a rcu read block will be
546 * protected against the plink disappearing.
547 */
548void mesh_path_flush_by_nexthop(struct sta_info *sta)
549{
550 struct ieee80211_sub_if_data *sdata = sta->sdata;
551 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
552 struct mesh_path *mpath;
553 struct hlist_node *n;
554
555 spin_lock_bh(&tbl->walk_lock);
556 hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
557 if (rcu_access_pointer(mpath->next_hop) == sta)
558 __mesh_path_del(tbl, mpath);
559 }
560 spin_unlock_bh(&tbl->walk_lock);
561}
562
563static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
564 const u8 *proxy)
565{
566 struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
567 struct mesh_path *mpath;
568 struct hlist_node *n;
569
570 spin_lock_bh(&tbl->walk_lock);
571 hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
572 if (ether_addr_equal(mpath->mpp, proxy))
573 __mesh_path_del(tbl, mpath);
574 }
575 spin_unlock_bh(&tbl->walk_lock);
576}
577
578static void table_flush_by_iface(struct mesh_table *tbl)
579{
580 struct mesh_path *mpath;
581 struct hlist_node *n;
582
583 spin_lock_bh(&tbl->walk_lock);
584 hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
585 __mesh_path_del(tbl, mpath);
586 }
587 spin_unlock_bh(&tbl->walk_lock);
588}
589
590/**
591 * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
592 *
593 * This function deletes both mesh paths as well as mesh portal paths.
594 *
595 * @sdata: interface data to match
596 *
597 */
598void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
599{
600 table_flush_by_iface(sdata->u.mesh.mesh_paths);
601 table_flush_by_iface(sdata->u.mesh.mpp_paths);
602}
603
604/**
605 * table_path_del - delete a path from the mesh or mpp table
606 *
607 * @tbl: mesh or mpp path table
608 * @sdata: local subif
609 * @addr: dst address (ETH_ALEN length)
610 *
611 * Returns: 0 if successful
612 */
613static int table_path_del(struct mesh_table *tbl,
614 struct ieee80211_sub_if_data *sdata,
615 const u8 *addr)
616{
617 struct mesh_path *mpath;
618
619 spin_lock_bh(&tbl->walk_lock);
620 mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
621 if (!mpath) {
622 spin_unlock_bh(&tbl->walk_lock);
623 return -ENXIO;
624 }
625
626 __mesh_path_del(tbl, mpath);
627 spin_unlock_bh(&tbl->walk_lock);
628 return 0;
629}
630
631
632/**
633 * mesh_path_del - delete a mesh path from the table
634 *
635 * @addr: dst address (ETH_ALEN length)
636 * @sdata: local subif
637 *
638 * Returns: 0 if successful
639 */
640int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
641{
642 int err;
643
644 /* flush relevant mpp entries first */
645 mpp_flush_by_proxy(sdata, addr);
646
647 err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
648 sdata->u.mesh.mesh_paths_generation++;
649 return err;
650}
651
652/**
653 * mesh_path_tx_pending - sends pending frames in a mesh path queue
654 *
655 * @mpath: mesh path to activate
656 *
657 * Locking: the state_lock of the mpath structure must NOT be held when calling
658 * this function.
659 */
660void mesh_path_tx_pending(struct mesh_path *mpath)
661{
662 if (mpath->flags & MESH_PATH_ACTIVE)
663 ieee80211_add_pending_skbs(mpath->sdata->local,
664 &mpath->frame_queue);
665}
666
667/**
668 * mesh_path_send_to_gates - sends pending frames to all known mesh gates
669 *
670 * @mpath: mesh path whose queue will be emptied
671 *
672 * If there is only one gate, the frames are transferred from the failed mpath
673 * queue to that gate's queue. If there are more than one gates, the frames
674 * are copied from each gate to the next. After frames are copied, the
675 * mpath queues are emptied onto the transmission queue.
676 */
677int mesh_path_send_to_gates(struct mesh_path *mpath)
678{
679 struct ieee80211_sub_if_data *sdata = mpath->sdata;
680 struct mesh_table *tbl;
681 struct mesh_path *from_mpath = mpath;
682 struct mesh_path *gate;
683 bool copy = false;
684
685 tbl = sdata->u.mesh.mesh_paths;
686
687 rcu_read_lock();
688 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
689 if (gate->flags & MESH_PATH_ACTIVE) {
690 mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
691 mesh_path_move_to_queue(gate, from_mpath, copy);
692 from_mpath = gate;
693 copy = true;
694 } else {
695 mpath_dbg(sdata,
696 "Not forwarding to %pM (flags %#x)\n",
697 gate->dst, gate->flags);
698 }
699 }
700
701 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
702 mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
703 mesh_path_tx_pending(gate);
704 }
705 rcu_read_unlock();
706
707 return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
708}
709
710/**
711 * mesh_path_discard_frame - discard a frame whose path could not be resolved
712 *
713 * @skb: frame to discard
714 * @sdata: network subif the frame was to be sent through
715 *
716 * Locking: the function must me called within a rcu_read_lock region
717 */
718void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
719 struct sk_buff *skb)
720{
721 kfree_skb(skb);
722 sdata->u.mesh.mshstats.dropped_frames_no_route++;
723}
724
725/**
726 * mesh_path_flush_pending - free the pending queue of a mesh path
727 *
728 * @mpath: mesh path whose queue has to be freed
729 *
730 * Locking: the function must me called within a rcu_read_lock region
731 */
732void mesh_path_flush_pending(struct mesh_path *mpath)
733{
734 struct sk_buff *skb;
735
736 while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
737 mesh_path_discard_frame(mpath->sdata, skb);
738}
739
740/**
741 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
742 *
743 * @mpath: the mesh path to modify
744 * @next_hop: the next hop to force
745 *
746 * Locking: this function must be called holding mpath->state_lock
747 */
748void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
749{
750 spin_lock_bh(&mpath->state_lock);
751 mesh_path_assign_nexthop(mpath, next_hop);
752 mpath->sn = 0xffff;
753 mpath->metric = 0;
754 mpath->hop_count = 0;
755 mpath->exp_time = 0;
756 mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;
757 mesh_path_activate(mpath);
758 spin_unlock_bh(&mpath->state_lock);
759 ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
760 /* init it at a low value - 0 start is tricky */
761 ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
762 mesh_path_tx_pending(mpath);
763}
764
765int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
766{
767 struct mesh_table *tbl_path, *tbl_mpp;
768 int ret;
769
770 tbl_path = mesh_table_alloc();
771 if (!tbl_path)
772 return -ENOMEM;
773
774 tbl_mpp = mesh_table_alloc();
775 if (!tbl_mpp) {
776 ret = -ENOMEM;
777 goto free_path;
778 }
779
780 sdata->u.mesh.mesh_paths = tbl_path;
781 sdata->u.mesh.mpp_paths = tbl_mpp;
782
783 return 0;
784
785free_path:
786 mesh_table_free(tbl_path);
787 return ret;
788}
789
790static
791void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
792 struct mesh_table *tbl)
793{
794 struct mesh_path *mpath;
795 struct hlist_node *n;
796
797 spin_lock_bh(&tbl->walk_lock);
798 hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
799 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
800 (!(mpath->flags & MESH_PATH_FIXED)) &&
801 time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
802 __mesh_path_del(tbl, mpath);
803 }
804 spin_unlock_bh(&tbl->walk_lock);
805}
806
807void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
808{
809 mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
810 mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
811}
812
813void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
814{
815 mesh_table_free(sdata->u.mesh.mesh_paths);
816 mesh_table_free(sdata->u.mesh.mpp_paths);
817}