Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / mac80211 / mesh_pathtbl.c
bloba5125624a76dce205b28e916a505faae765539ae
1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
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 */
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"
21 static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
23 static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
25 /* Use last four bytes of hw addr as hash index */
26 return jhash_1word(*(u32 *)(addr+2), seed);
29 static 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,
38 static inline bool mpath_expired(struct mesh_path *mpath)
40 return (mpath->flags & MESH_PATH_ACTIVE) &&
41 time_after(jiffies, mpath->exp_time) &&
42 !(mpath->flags & MESH_PATH_FIXED);
45 static void mesh_path_rht_free(void *ptr, void *tblptr)
47 struct mesh_path *mpath = ptr;
48 struct mesh_table *tbl = tblptr;
50 mesh_path_free_rcu(tbl, mpath);
53 static struct mesh_table *mesh_table_alloc(void)
55 struct mesh_table *newtbl;
57 newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
58 if (!newtbl)
59 return NULL;
61 INIT_HLIST_HEAD(&newtbl->known_gates);
62 atomic_set(&newtbl->entries, 0);
63 spin_lock_init(&newtbl->gates_lock);
65 return newtbl;
68 static void mesh_table_free(struct mesh_table *tbl)
70 rhashtable_free_and_destroy(&tbl->rhead,
71 mesh_path_rht_free, tbl);
72 kfree(tbl);
75 /**
77 * mesh_path_assign_nexthop - update mesh path next hop
79 * @mpath: mesh path to update
80 * @sta: next hop to assign
82 * Locking: mpath->state_lock must be held when calling this function
84 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
86 struct sk_buff *skb;
87 struct ieee80211_hdr *hdr;
88 unsigned long flags;
90 rcu_assign_pointer(mpath->next_hop, sta);
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);
100 spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
103 static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
104 struct mesh_path *gate_mpath)
106 struct ieee80211_hdr *hdr;
107 struct ieee80211s_hdr *mshdr;
108 int mesh_hdrlen, hdrlen;
109 char *next_hop;
111 hdr = (struct ieee80211_hdr *) skb->data;
112 hdrlen = ieee80211_hdrlen(hdr->frame_control);
113 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
115 if (!(mshdr->flags & MESH_FLAGS_AE)) {
116 /* size of the fixed part of the mesh header */
117 mesh_hdrlen = 6;
119 /* make room for the two extended addresses */
120 skb_push(skb, 2 * ETH_ALEN);
121 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
123 hdr = (struct ieee80211_hdr *) skb->data;
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);
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);
145 * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
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.
151 * If a frame already has an Address Extension field, only the next hop and
152 * destination addresses are updated.
154 * The gate mpath must be an active mpath with a valid mpath->next_hop.
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.
161 static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
162 struct mesh_path *from_mpath,
163 bool copy)
165 struct sk_buff *skb, *fskb, *tmp;
166 struct sk_buff_head failq;
167 unsigned long flags;
169 if (WARN_ON(gate_mpath == from_mpath))
170 return;
171 if (WARN_ON(!gate_mpath->next_hop))
172 return;
174 __skb_queue_head_init(&failq);
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);
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;
187 skb = skb_copy(fskb, GFP_ATOMIC);
188 if (WARN_ON(!skb))
189 break;
191 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
192 skb_queue_tail(&gate_mpath->frame_queue, skb);
194 if (copy)
195 continue;
197 __skb_unlink(fskb, &failq);
198 kfree_skb(fskb);
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));
204 if (!copy)
205 return;
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);
213 static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
214 struct ieee80211_sub_if_data *sdata)
216 struct mesh_path *mpath;
218 mpath = rhashtable_lookup_fast(&tbl->rhead, dst, mesh_rht_params);
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);
225 return mpath;
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
233 * Returns: pointer to the mesh path structure, or NULL if not found
235 * Locking: must be called within a read rcu section.
237 struct mesh_path *
238 mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
240 return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata);
243 struct mesh_path *
244 mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
246 return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
249 static struct mesh_path *
250 __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
252 int i = 0, ret;
253 struct mesh_path *mpath = NULL;
254 struct rhashtable_iter iter;
256 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
257 if (ret)
258 return NULL;
260 rhashtable_walk_start(&iter);
262 while ((mpath = rhashtable_walk_next(&iter))) {
263 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
264 continue;
265 if (IS_ERR(mpath))
266 break;
267 if (i++ == idx)
268 break;
270 rhashtable_walk_stop(&iter);
271 rhashtable_walk_exit(&iter);
273 if (IS_ERR(mpath) || !mpath)
274 return NULL;
276 if (mpath_expired(mpath)) {
277 spin_lock_bh(&mpath->state_lock);
278 mpath->flags &= ~MESH_PATH_ACTIVE;
279 spin_unlock_bh(&mpath->state_lock);
281 return mpath;
285 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
286 * @idx: index
287 * @sdata: local subif, or NULL for all entries
289 * Returns: pointer to the mesh path structure, or NULL if not found.
291 * Locking: must be called within a read rcu section.
293 struct mesh_path *
294 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
296 return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
300 * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
301 * @idx: index
302 * @sdata: local subif, or NULL for all entries
304 * Returns: pointer to the proxy path structure, or NULL if not found.
306 * Locking: must be called within a read rcu section.
308 struct mesh_path *
309 mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
311 return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
315 * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
316 * @mpath: gate path to add to table
318 int mesh_path_add_gate(struct mesh_path *mpath)
320 struct mesh_table *tbl;
321 int err;
323 rcu_read_lock();
324 tbl = mpath->sdata->u.mesh.mesh_paths;
326 spin_lock_bh(&mpath->state_lock);
327 if (mpath->is_gate) {
328 err = -EEXIST;
329 spin_unlock_bh(&mpath->state_lock);
330 goto err_rcu;
332 mpath->is_gate = true;
333 mpath->sdata->u.mesh.num_gates++;
335 spin_lock(&tbl->gates_lock);
336 hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
337 spin_unlock(&tbl->gates_lock);
339 spin_unlock_bh(&mpath->state_lock);
341 mpath_dbg(mpath->sdata,
342 "Mesh path: Recorded new gate: %pM. %d known gates\n",
343 mpath->dst, mpath->sdata->u.mesh.num_gates);
344 err = 0;
345 err_rcu:
346 rcu_read_unlock();
347 return err;
351 * mesh_gate_del - remove a mesh gate from the list of known gates
352 * @tbl: table which holds our list of known gates
353 * @mpath: gate mpath
355 static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
357 lockdep_assert_held(&mpath->state_lock);
358 if (!mpath->is_gate)
359 return;
361 mpath->is_gate = false;
362 spin_lock_bh(&tbl->gates_lock);
363 hlist_del_rcu(&mpath->gate_list);
364 mpath->sdata->u.mesh.num_gates--;
365 spin_unlock_bh(&tbl->gates_lock);
367 mpath_dbg(mpath->sdata,
368 "Mesh path: Deleted gate: %pM. %d known gates\n",
369 mpath->dst, mpath->sdata->u.mesh.num_gates);
373 * mesh_gate_num - number of gates known to this interface
374 * @sdata: subif data
376 int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
378 return sdata->u.mesh.num_gates;
381 static
382 struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
383 const u8 *dst, gfp_t gfp_flags)
385 struct mesh_path *new_mpath;
387 new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
388 if (!new_mpath)
389 return NULL;
391 memcpy(new_mpath->dst, dst, ETH_ALEN);
392 eth_broadcast_addr(new_mpath->rann_snd_addr);
393 new_mpath->is_root = false;
394 new_mpath->sdata = sdata;
395 new_mpath->flags = 0;
396 skb_queue_head_init(&new_mpath->frame_queue);
397 new_mpath->exp_time = jiffies;
398 spin_lock_init(&new_mpath->state_lock);
399 timer_setup(&new_mpath->timer, mesh_path_timer, 0);
401 return new_mpath;
405 * mesh_path_add - allocate and add a new path to the mesh path table
406 * @dst: destination address of the path (ETH_ALEN length)
407 * @sdata: local subif
409 * Returns: 0 on success
411 * State: the initial state of the new path is set to 0
413 struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
414 const u8 *dst)
416 struct mesh_table *tbl;
417 struct mesh_path *mpath, *new_mpath;
418 int ret;
420 if (ether_addr_equal(dst, sdata->vif.addr))
421 /* never add ourselves as neighbours */
422 return ERR_PTR(-ENOTSUPP);
424 if (is_multicast_ether_addr(dst))
425 return ERR_PTR(-ENOTSUPP);
427 if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
428 return ERR_PTR(-ENOSPC);
430 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
431 if (!new_mpath)
432 return ERR_PTR(-ENOMEM);
434 tbl = sdata->u.mesh.mesh_paths;
435 do {
436 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
437 &new_mpath->rhash,
438 mesh_rht_params);
440 if (ret == -EEXIST)
441 mpath = rhashtable_lookup_fast(&tbl->rhead,
442 dst,
443 mesh_rht_params);
445 } while (unlikely(ret == -EEXIST && !mpath));
447 if (ret && ret != -EEXIST)
448 return ERR_PTR(ret);
450 /* At this point either new_mpath was added, or we found a
451 * matching entry already in the table; in the latter case
452 * free the unnecessary new entry.
454 if (ret == -EEXIST) {
455 kfree(new_mpath);
456 new_mpath = mpath;
458 sdata->u.mesh.mesh_paths_generation++;
459 return new_mpath;
462 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
463 const u8 *dst, const u8 *mpp)
465 struct mesh_table *tbl;
466 struct mesh_path *new_mpath;
467 int ret;
469 if (ether_addr_equal(dst, sdata->vif.addr))
470 /* never add ourselves as neighbours */
471 return -ENOTSUPP;
473 if (is_multicast_ether_addr(dst))
474 return -ENOTSUPP;
476 new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
478 if (!new_mpath)
479 return -ENOMEM;
481 memcpy(new_mpath->mpp, mpp, ETH_ALEN);
482 tbl = sdata->u.mesh.mpp_paths;
483 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
484 &new_mpath->rhash,
485 mesh_rht_params);
487 sdata->u.mesh.mpp_paths_generation++;
488 return ret;
493 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
495 * @sta: broken peer link
497 * This function must be called from the rate control algorithm if enough
498 * delivery errors suggest that a peer link is no longer usable.
500 void mesh_plink_broken(struct sta_info *sta)
502 struct ieee80211_sub_if_data *sdata = sta->sdata;
503 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
504 static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
505 struct mesh_path *mpath;
506 struct rhashtable_iter iter;
507 int ret;
509 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
510 if (ret)
511 return;
513 rhashtable_walk_start(&iter);
515 while ((mpath = rhashtable_walk_next(&iter))) {
516 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
517 continue;
518 if (IS_ERR(mpath))
519 break;
520 if (rcu_access_pointer(mpath->next_hop) == sta &&
521 mpath->flags & MESH_PATH_ACTIVE &&
522 !(mpath->flags & MESH_PATH_FIXED)) {
523 spin_lock_bh(&mpath->state_lock);
524 mpath->flags &= ~MESH_PATH_ACTIVE;
525 ++mpath->sn;
526 spin_unlock_bh(&mpath->state_lock);
527 mesh_path_error_tx(sdata,
528 sdata->u.mesh.mshcfg.element_ttl,
529 mpath->dst, mpath->sn,
530 WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
533 rhashtable_walk_stop(&iter);
534 rhashtable_walk_exit(&iter);
537 static void mesh_path_free_rcu(struct mesh_table *tbl,
538 struct mesh_path *mpath)
540 struct ieee80211_sub_if_data *sdata = mpath->sdata;
542 spin_lock_bh(&mpath->state_lock);
543 mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
544 mesh_gate_del(tbl, mpath);
545 spin_unlock_bh(&mpath->state_lock);
546 del_timer_sync(&mpath->timer);
547 atomic_dec(&sdata->u.mesh.mpaths);
548 atomic_dec(&tbl->entries);
549 kfree_rcu(mpath, rcu);
552 static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
554 rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
555 mesh_path_free_rcu(tbl, mpath);
559 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
561 * @sta: mesh peer to match
563 * RCU notes: this function is called when a mesh plink transitions from
564 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
565 * allows path creation. This will happen before the sta can be freed (because
566 * sta_info_destroy() calls this) so any reader in a rcu read block will be
567 * protected against the plink disappearing.
569 void mesh_path_flush_by_nexthop(struct sta_info *sta)
571 struct ieee80211_sub_if_data *sdata = sta->sdata;
572 struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
573 struct mesh_path *mpath;
574 struct rhashtable_iter iter;
575 int ret;
577 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
578 if (ret)
579 return;
581 rhashtable_walk_start(&iter);
583 while ((mpath = rhashtable_walk_next(&iter))) {
584 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
585 continue;
586 if (IS_ERR(mpath))
587 break;
589 if (rcu_access_pointer(mpath->next_hop) == sta)
590 __mesh_path_del(tbl, mpath);
593 rhashtable_walk_stop(&iter);
594 rhashtable_walk_exit(&iter);
597 static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
598 const u8 *proxy)
600 struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
601 struct mesh_path *mpath;
602 struct rhashtable_iter iter;
603 int ret;
605 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
606 if (ret)
607 return;
609 rhashtable_walk_start(&iter);
611 while ((mpath = rhashtable_walk_next(&iter))) {
612 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
613 continue;
614 if (IS_ERR(mpath))
615 break;
617 if (ether_addr_equal(mpath->mpp, proxy))
618 __mesh_path_del(tbl, mpath);
621 rhashtable_walk_stop(&iter);
622 rhashtable_walk_exit(&iter);
625 static void table_flush_by_iface(struct mesh_table *tbl)
627 struct mesh_path *mpath;
628 struct rhashtable_iter iter;
629 int ret;
631 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
632 if (ret)
633 return;
635 rhashtable_walk_start(&iter);
637 while ((mpath = rhashtable_walk_next(&iter))) {
638 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
639 continue;
640 if (IS_ERR(mpath))
641 break;
642 __mesh_path_del(tbl, mpath);
645 rhashtable_walk_stop(&iter);
646 rhashtable_walk_exit(&iter);
650 * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
652 * This function deletes both mesh paths as well as mesh portal paths.
654 * @sdata: interface data to match
657 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
659 table_flush_by_iface(sdata->u.mesh.mesh_paths);
660 table_flush_by_iface(sdata->u.mesh.mpp_paths);
664 * table_path_del - delete a path from the mesh or mpp table
666 * @tbl: mesh or mpp path table
667 * @sdata: local subif
668 * @addr: dst address (ETH_ALEN length)
670 * Returns: 0 if successful
672 static int table_path_del(struct mesh_table *tbl,
673 struct ieee80211_sub_if_data *sdata,
674 const u8 *addr)
676 struct mesh_path *mpath;
678 rcu_read_lock();
679 mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
680 if (!mpath) {
681 rcu_read_unlock();
682 return -ENXIO;
685 __mesh_path_del(tbl, mpath);
686 rcu_read_unlock();
687 return 0;
692 * mesh_path_del - delete a mesh path from the table
694 * @addr: dst address (ETH_ALEN length)
695 * @sdata: local subif
697 * Returns: 0 if successful
699 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
701 int err;
703 /* flush relevant mpp entries first */
704 mpp_flush_by_proxy(sdata, addr);
706 err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
707 sdata->u.mesh.mesh_paths_generation++;
708 return err;
712 * mesh_path_tx_pending - sends pending frames in a mesh path queue
714 * @mpath: mesh path to activate
716 * Locking: the state_lock of the mpath structure must NOT be held when calling
717 * this function.
719 void mesh_path_tx_pending(struct mesh_path *mpath)
721 if (mpath->flags & MESH_PATH_ACTIVE)
722 ieee80211_add_pending_skbs(mpath->sdata->local,
723 &mpath->frame_queue);
727 * mesh_path_send_to_gates - sends pending frames to all known mesh gates
729 * @mpath: mesh path whose queue will be emptied
731 * If there is only one gate, the frames are transferred from the failed mpath
732 * queue to that gate's queue. If there are more than one gates, the frames
733 * are copied from each gate to the next. After frames are copied, the
734 * mpath queues are emptied onto the transmission queue.
736 int mesh_path_send_to_gates(struct mesh_path *mpath)
738 struct ieee80211_sub_if_data *sdata = mpath->sdata;
739 struct mesh_table *tbl;
740 struct mesh_path *from_mpath = mpath;
741 struct mesh_path *gate;
742 bool copy = false;
744 tbl = sdata->u.mesh.mesh_paths;
746 rcu_read_lock();
747 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
748 if (gate->flags & MESH_PATH_ACTIVE) {
749 mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
750 mesh_path_move_to_queue(gate, from_mpath, copy);
751 from_mpath = gate;
752 copy = true;
753 } else {
754 mpath_dbg(sdata,
755 "Not forwarding to %pM (flags %#x)\n",
756 gate->dst, gate->flags);
760 hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
761 mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
762 mesh_path_tx_pending(gate);
764 rcu_read_unlock();
766 return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
770 * mesh_path_discard_frame - discard a frame whose path could not be resolved
772 * @skb: frame to discard
773 * @sdata: network subif the frame was to be sent through
775 * Locking: the function must me called within a rcu_read_lock region
777 void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
778 struct sk_buff *skb)
780 kfree_skb(skb);
781 sdata->u.mesh.mshstats.dropped_frames_no_route++;
785 * mesh_path_flush_pending - free the pending queue of a mesh path
787 * @mpath: mesh path whose queue has to be freed
789 * Locking: the function must me called within a rcu_read_lock region
791 void mesh_path_flush_pending(struct mesh_path *mpath)
793 struct sk_buff *skb;
795 while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
796 mesh_path_discard_frame(mpath->sdata, skb);
800 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
802 * @mpath: the mesh path to modify
803 * @next_hop: the next hop to force
805 * Locking: this function must be called holding mpath->state_lock
807 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
809 spin_lock_bh(&mpath->state_lock);
810 mesh_path_assign_nexthop(mpath, next_hop);
811 mpath->sn = 0xffff;
812 mpath->metric = 0;
813 mpath->hop_count = 0;
814 mpath->exp_time = 0;
815 mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;
816 mesh_path_activate(mpath);
817 spin_unlock_bh(&mpath->state_lock);
818 ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
819 /* init it at a low value - 0 start is tricky */
820 ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
821 mesh_path_tx_pending(mpath);
824 int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
826 struct mesh_table *tbl_path, *tbl_mpp;
827 int ret;
829 tbl_path = mesh_table_alloc();
830 if (!tbl_path)
831 return -ENOMEM;
833 tbl_mpp = mesh_table_alloc();
834 if (!tbl_mpp) {
835 ret = -ENOMEM;
836 goto free_path;
839 rhashtable_init(&tbl_path->rhead, &mesh_rht_params);
840 rhashtable_init(&tbl_mpp->rhead, &mesh_rht_params);
842 sdata->u.mesh.mesh_paths = tbl_path;
843 sdata->u.mesh.mpp_paths = tbl_mpp;
845 return 0;
847 free_path:
848 mesh_table_free(tbl_path);
849 return ret;
852 static
853 void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
854 struct mesh_table *tbl)
856 struct mesh_path *mpath;
857 struct rhashtable_iter iter;
858 int ret;
860 ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL);
861 if (ret)
862 return;
864 rhashtable_walk_start(&iter);
866 while ((mpath = rhashtable_walk_next(&iter))) {
867 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
868 continue;
869 if (IS_ERR(mpath))
870 break;
871 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
872 (!(mpath->flags & MESH_PATH_FIXED)) &&
873 time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
874 __mesh_path_del(tbl, mpath);
877 rhashtable_walk_stop(&iter);
878 rhashtable_walk_exit(&iter);
881 void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
883 mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
884 mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
887 void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
889 mesh_table_free(sdata->u.mesh.mesh_paths);
890 mesh_table_free(sdata->u.mesh.mpp_paths);