2 * Copyright (c) 2008 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.
10 #include <linux/etherdevice.h>
11 #include <linux/list.h>
12 #include <linux/random.h>
13 #include <linux/spinlock.h>
14 #include <linux/string.h>
15 #include <net/mac80211.h>
16 #include "ieee80211_i.h"
19 /* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
20 #define INIT_PATHS_SIZE_ORDER 2
22 /* Keep the mean chain length below this constant */
23 #define MEAN_CHAIN_LEN 2
25 #define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \
26 time_after(jiffies, mpath->exp_time) && \
27 !(mpath->flags & MESH_PATH_FIXED))
30 struct hlist_node list
;
32 /* This indirection allows two different tables to point to the same
33 * mesh_path structure, useful when resizing
35 struct mesh_path
*mpath
;
38 static struct mesh_table
*mesh_paths
;
39 static struct mesh_table
*mpp_paths
; /* Store paths for MPP&MAP */
41 /* This lock will have the grow table function as writer and add / delete nodes
42 * as readers. When reading the table (i.e. doing lookups) we are well protected
45 static DEFINE_RWLOCK(pathtbl_resize_lock
);
49 * mesh_path_assign_nexthop - update mesh path next hop
51 * @mpath: mesh path to update
52 * @sta: next hop to assign
54 * Locking: mpath->state_lock must be held when calling this function
56 void mesh_path_assign_nexthop(struct mesh_path
*mpath
, struct sta_info
*sta
)
58 rcu_assign_pointer(mpath
->next_hop
, sta
);
63 * mesh_path_lookup - look up a path in the mesh path table
64 * @dst: hardware address (ETH_ALEN length) of destination
67 * Returns: pointer to the mesh path structure, or NULL if not found
69 * Locking: must be called within a read rcu section.
71 struct mesh_path
*mesh_path_lookup(u8
*dst
, struct ieee80211_sub_if_data
*sdata
)
73 struct mesh_path
*mpath
;
75 struct hlist_head
*bucket
;
76 struct mesh_table
*tbl
;
77 struct mpath_node
*node
;
79 tbl
= rcu_dereference(mesh_paths
);
81 bucket
= &tbl
->hash_buckets
[mesh_table_hash(dst
, sdata
, tbl
)];
82 hlist_for_each_entry_rcu(node
, n
, bucket
, list
) {
84 if (mpath
->sdata
== sdata
&&
85 memcmp(dst
, mpath
->dst
, ETH_ALEN
) == 0) {
86 if (MPATH_EXPIRED(mpath
)) {
87 spin_lock_bh(&mpath
->state_lock
);
88 if (MPATH_EXPIRED(mpath
))
89 mpath
->flags
&= ~MESH_PATH_ACTIVE
;
90 spin_unlock_bh(&mpath
->state_lock
);
98 struct mesh_path
*mpp_path_lookup(u8
*dst
, struct ieee80211_sub_if_data
*sdata
)
100 struct mesh_path
*mpath
;
101 struct hlist_node
*n
;
102 struct hlist_head
*bucket
;
103 struct mesh_table
*tbl
;
104 struct mpath_node
*node
;
106 tbl
= rcu_dereference(mpp_paths
);
108 bucket
= &tbl
->hash_buckets
[mesh_table_hash(dst
, sdata
, tbl
)];
109 hlist_for_each_entry_rcu(node
, n
, bucket
, list
) {
111 if (mpath
->sdata
== sdata
&&
112 memcmp(dst
, mpath
->dst
, ETH_ALEN
) == 0) {
113 if (MPATH_EXPIRED(mpath
)) {
114 spin_lock_bh(&mpath
->state_lock
);
115 if (MPATH_EXPIRED(mpath
))
116 mpath
->flags
&= ~MESH_PATH_ACTIVE
;
117 spin_unlock_bh(&mpath
->state_lock
);
127 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
129 * @sdata: local subif, or NULL for all entries
131 * Returns: pointer to the mesh path structure, or NULL if not found.
133 * Locking: must be called within a read rcu section.
135 struct mesh_path
*mesh_path_lookup_by_idx(int idx
, struct ieee80211_sub_if_data
*sdata
)
137 struct mpath_node
*node
;
138 struct hlist_node
*p
;
142 for_each_mesh_entry(mesh_paths
, p
, node
, i
) {
143 if (sdata
&& node
->mpath
->sdata
!= sdata
)
146 if (MPATH_EXPIRED(node
->mpath
)) {
147 spin_lock_bh(&node
->mpath
->state_lock
);
148 if (MPATH_EXPIRED(node
->mpath
))
149 node
->mpath
->flags
&= ~MESH_PATH_ACTIVE
;
150 spin_unlock_bh(&node
->mpath
->state_lock
);
160 * mesh_path_add - allocate and add a new path to the mesh path table
161 * @addr: destination address of the path (ETH_ALEN length)
162 * @sdata: local subif
164 * Returns: 0 on sucess
166 * State: the initial state of the new path is set to 0
168 int mesh_path_add(u8
*dst
, struct ieee80211_sub_if_data
*sdata
)
170 struct mesh_path
*mpath
, *new_mpath
;
171 struct mpath_node
*node
, *new_node
;
172 struct hlist_head
*bucket
;
173 struct hlist_node
*n
;
178 if (memcmp(dst
, sdata
->dev
->dev_addr
, ETH_ALEN
) == 0)
179 /* never add ourselves as neighbours */
182 if (is_multicast_ether_addr(dst
))
185 if (atomic_add_unless(&sdata
->u
.mesh
.mpaths
, 1, MESH_MAX_MPATHS
) == 0)
189 new_mpath
= kzalloc(sizeof(struct mesh_path
), GFP_KERNEL
);
193 new_node
= kmalloc(sizeof(struct mpath_node
), GFP_KERNEL
);
197 read_lock(&pathtbl_resize_lock
);
198 memcpy(new_mpath
->dst
, dst
, ETH_ALEN
);
199 new_mpath
->sdata
= sdata
;
200 new_mpath
->flags
= 0;
201 skb_queue_head_init(&new_mpath
->frame_queue
);
202 new_node
->mpath
= new_mpath
;
203 new_mpath
->timer
.data
= (unsigned long) new_mpath
;
204 new_mpath
->timer
.function
= mesh_path_timer
;
205 new_mpath
->exp_time
= jiffies
;
206 spin_lock_init(&new_mpath
->state_lock
);
207 init_timer(&new_mpath
->timer
);
209 hash_idx
= mesh_table_hash(dst
, sdata
, mesh_paths
);
210 bucket
= &mesh_paths
->hash_buckets
[hash_idx
];
212 spin_lock(&mesh_paths
->hashwlock
[hash_idx
]);
215 hlist_for_each_entry(node
, n
, bucket
, list
) {
217 if (mpath
->sdata
== sdata
&& memcmp(dst
, mpath
->dst
, ETH_ALEN
) == 0)
221 hlist_add_head_rcu(&new_node
->list
, bucket
);
222 if (atomic_inc_return(&mesh_paths
->entries
) >=
223 mesh_paths
->mean_chain_len
* (mesh_paths
->hash_mask
+ 1))
226 spin_unlock(&mesh_paths
->hashwlock
[hash_idx
]);
227 read_unlock(&pathtbl_resize_lock
);
229 struct mesh_table
*oldtbl
, *newtbl
;
231 write_lock(&pathtbl_resize_lock
);
233 newtbl
= mesh_table_grow(mesh_paths
);
235 write_unlock(&pathtbl_resize_lock
);
238 rcu_assign_pointer(mesh_paths
, newtbl
);
239 write_unlock(&pathtbl_resize_lock
);
242 mesh_table_free(oldtbl
, false);
247 spin_unlock(&mesh_paths
->hashwlock
[hash_idx
]);
248 read_unlock(&pathtbl_resize_lock
);
253 atomic_dec(&sdata
->u
.mesh
.mpaths
);
258 int mpp_path_add(u8
*dst
, u8
*mpp
, struct ieee80211_sub_if_data
*sdata
)
260 struct mesh_path
*mpath
, *new_mpath
;
261 struct mpath_node
*node
, *new_node
;
262 struct hlist_head
*bucket
;
263 struct hlist_node
*n
;
269 if (memcmp(dst
, sdata
->dev
->dev_addr
, ETH_ALEN
) == 0)
270 /* never add ourselves as neighbours */
273 if (is_multicast_ether_addr(dst
))
277 new_mpath
= kzalloc(sizeof(struct mesh_path
), GFP_KERNEL
);
281 new_node
= kmalloc(sizeof(struct mpath_node
), GFP_KERNEL
);
285 read_lock(&pathtbl_resize_lock
);
286 memcpy(new_mpath
->dst
, dst
, ETH_ALEN
);
287 memcpy(new_mpath
->mpp
, mpp
, ETH_ALEN
);
288 new_mpath
->sdata
= sdata
;
289 new_mpath
->flags
= 0;
290 skb_queue_head_init(&new_mpath
->frame_queue
);
291 new_node
->mpath
= new_mpath
;
292 new_mpath
->exp_time
= jiffies
;
293 spin_lock_init(&new_mpath
->state_lock
);
295 hash_idx
= mesh_table_hash(dst
, sdata
, mpp_paths
);
296 bucket
= &mpp_paths
->hash_buckets
[hash_idx
];
298 spin_lock(&mpp_paths
->hashwlock
[hash_idx
]);
301 hlist_for_each_entry(node
, n
, bucket
, list
) {
303 if (mpath
->sdata
== sdata
&& memcmp(dst
, mpath
->dst
, ETH_ALEN
) == 0)
307 hlist_add_head_rcu(&new_node
->list
, bucket
);
308 if (atomic_inc_return(&mpp_paths
->entries
) >=
309 mpp_paths
->mean_chain_len
* (mpp_paths
->hash_mask
+ 1))
312 spin_unlock(&mpp_paths
->hashwlock
[hash_idx
]);
313 read_unlock(&pathtbl_resize_lock
);
315 struct mesh_table
*oldtbl
, *newtbl
;
317 write_lock(&pathtbl_resize_lock
);
319 newtbl
= mesh_table_grow(mpp_paths
);
321 write_unlock(&pathtbl_resize_lock
);
324 rcu_assign_pointer(mpp_paths
, newtbl
);
325 write_unlock(&pathtbl_resize_lock
);
328 mesh_table_free(oldtbl
, false);
333 spin_unlock(&mpp_paths
->hashwlock
[hash_idx
]);
334 read_unlock(&pathtbl_resize_lock
);
344 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
346 * @sta: broken peer link
348 * This function must be called from the rate control algorithm if enough
349 * delivery errors suggest that a peer link is no longer usable.
351 void mesh_plink_broken(struct sta_info
*sta
)
353 struct mesh_path
*mpath
;
354 struct mpath_node
*node
;
355 struct hlist_node
*p
;
356 struct ieee80211_sub_if_data
*sdata
= sta
->sdata
;
360 for_each_mesh_entry(mesh_paths
, p
, node
, i
) {
362 spin_lock_bh(&mpath
->state_lock
);
363 if (mpath
->next_hop
== sta
&&
364 mpath
->flags
& MESH_PATH_ACTIVE
&&
365 !(mpath
->flags
& MESH_PATH_FIXED
)) {
366 mpath
->flags
&= ~MESH_PATH_ACTIVE
;
368 spin_unlock_bh(&mpath
->state_lock
);
369 mesh_path_error_tx(mpath
->dst
,
370 cpu_to_le32(mpath
->dsn
),
371 sdata
->dev
->broadcast
, sdata
);
373 spin_unlock_bh(&mpath
->state_lock
);
379 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
381 * @sta - mesh peer to match
383 * RCU notes: this function is called when a mesh plink transitions from
384 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
385 * allows path creation. This will happen before the sta can be freed (because
386 * sta_info_destroy() calls this) so any reader in a rcu read block will be
387 * protected against the plink disappearing.
389 void mesh_path_flush_by_nexthop(struct sta_info
*sta
)
391 struct mesh_path
*mpath
;
392 struct mpath_node
*node
;
393 struct hlist_node
*p
;
396 for_each_mesh_entry(mesh_paths
, p
, node
, i
) {
398 if (mpath
->next_hop
== sta
)
399 mesh_path_del(mpath
->dst
, mpath
->sdata
);
403 void mesh_path_flush(struct ieee80211_sub_if_data
*sdata
)
405 struct mesh_path
*mpath
;
406 struct mpath_node
*node
;
407 struct hlist_node
*p
;
410 for_each_mesh_entry(mesh_paths
, p
, node
, i
) {
412 if (mpath
->sdata
== sdata
)
413 mesh_path_del(mpath
->dst
, mpath
->sdata
);
417 static void mesh_path_node_reclaim(struct rcu_head
*rp
)
419 struct mpath_node
*node
= container_of(rp
, struct mpath_node
, rcu
);
420 struct ieee80211_sub_if_data
*sdata
= node
->mpath
->sdata
;
422 del_timer_sync(&node
->mpath
->timer
);
423 atomic_dec(&sdata
->u
.mesh
.mpaths
);
429 * mesh_path_del - delete a mesh path from the table
431 * @addr: dst address (ETH_ALEN length)
432 * @sdata: local subif
434 * Returns: 0 if succesful
436 int mesh_path_del(u8
*addr
, struct ieee80211_sub_if_data
*sdata
)
438 struct mesh_path
*mpath
;
439 struct mpath_node
*node
;
440 struct hlist_head
*bucket
;
441 struct hlist_node
*n
;
445 read_lock(&pathtbl_resize_lock
);
446 hash_idx
= mesh_table_hash(addr
, sdata
, mesh_paths
);
447 bucket
= &mesh_paths
->hash_buckets
[hash_idx
];
449 spin_lock(&mesh_paths
->hashwlock
[hash_idx
]);
450 hlist_for_each_entry(node
, n
, bucket
, list
) {
452 if (mpath
->sdata
== sdata
&&
453 memcmp(addr
, mpath
->dst
, ETH_ALEN
) == 0) {
454 spin_lock_bh(&mpath
->state_lock
);
455 mpath
->flags
|= MESH_PATH_RESOLVING
;
456 hlist_del_rcu(&node
->list
);
457 call_rcu(&node
->rcu
, mesh_path_node_reclaim
);
458 atomic_dec(&mesh_paths
->entries
);
459 spin_unlock_bh(&mpath
->state_lock
);
466 spin_unlock(&mesh_paths
->hashwlock
[hash_idx
]);
467 read_unlock(&pathtbl_resize_lock
);
472 * mesh_path_tx_pending - sends pending frames in a mesh path queue
474 * @mpath: mesh path to activate
476 * Locking: the state_lock of the mpath structure must NOT be held when calling
479 void mesh_path_tx_pending(struct mesh_path
*mpath
)
483 while ((skb
= skb_dequeue(&mpath
->frame_queue
)) &&
484 (mpath
->flags
& MESH_PATH_ACTIVE
))
489 * mesh_path_discard_frame - discard a frame whose path could not be resolved
491 * @skb: frame to discard
492 * @sdata: network subif the frame was to be sent through
494 * If the frame was beign forwarded from another MP, a PERR frame will be sent
497 * Locking: the function must me called within a rcu_read_lock region
499 void mesh_path_discard_frame(struct sk_buff
*skb
,
500 struct ieee80211_sub_if_data
*sdata
)
502 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) skb
->data
;
503 struct mesh_path
*mpath
;
506 if (memcmp(hdr
->addr4
, sdata
->dev
->dev_addr
, ETH_ALEN
) != 0) {
511 mpath
= mesh_path_lookup(da
, sdata
);
514 mesh_path_error_tx(skb
->data
, cpu_to_le32(dsn
), ra
, sdata
);
518 sdata
->u
.mesh
.mshstats
.dropped_frames_no_route
++;
522 * mesh_path_flush_pending - free the pending queue of a mesh path
524 * @mpath: mesh path whose queue has to be freed
526 * Locking: the function must me called withing a rcu_read_lock region
528 void mesh_path_flush_pending(struct mesh_path
*mpath
)
532 while ((skb
= skb_dequeue(&mpath
->frame_queue
)) &&
533 (mpath
->flags
& MESH_PATH_ACTIVE
))
534 mesh_path_discard_frame(skb
, mpath
->sdata
);
538 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
540 * @mpath: the mesh path to modify
541 * @next_hop: the next hop to force
543 * Locking: this function must be called holding mpath->state_lock
545 void mesh_path_fix_nexthop(struct mesh_path
*mpath
, struct sta_info
*next_hop
)
547 spin_lock_bh(&mpath
->state_lock
);
548 mesh_path_assign_nexthop(mpath
, next_hop
);
551 mpath
->hop_count
= 0;
553 mpath
->flags
|= MESH_PATH_FIXED
;
554 mesh_path_activate(mpath
);
555 spin_unlock_bh(&mpath
->state_lock
);
556 mesh_path_tx_pending(mpath
);
559 static void mesh_path_node_free(struct hlist_node
*p
, bool free_leafs
)
561 struct mesh_path
*mpath
;
562 struct mpath_node
*node
= hlist_entry(p
, struct mpath_node
, list
);
570 static int mesh_path_node_copy(struct hlist_node
*p
, struct mesh_table
*newtbl
)
572 struct mesh_path
*mpath
;
573 struct mpath_node
*node
, *new_node
;
576 new_node
= kmalloc(sizeof(struct mpath_node
), GFP_ATOMIC
);
577 if (new_node
== NULL
)
580 node
= hlist_entry(p
, struct mpath_node
, list
);
582 new_node
->mpath
= mpath
;
583 hash_idx
= mesh_table_hash(mpath
->dst
, mpath
->sdata
, newtbl
);
584 hlist_add_head(&new_node
->list
,
585 &newtbl
->hash_buckets
[hash_idx
]);
589 int mesh_pathtbl_init(void)
591 mesh_paths
= mesh_table_alloc(INIT_PATHS_SIZE_ORDER
);
594 mesh_paths
->free_node
= &mesh_path_node_free
;
595 mesh_paths
->copy_node
= &mesh_path_node_copy
;
596 mesh_paths
->mean_chain_len
= MEAN_CHAIN_LEN
;
598 mpp_paths
= mesh_table_alloc(INIT_PATHS_SIZE_ORDER
);
600 mesh_table_free(mesh_paths
, true);
603 mpp_paths
->free_node
= &mesh_path_node_free
;
604 mpp_paths
->copy_node
= &mesh_path_node_copy
;
605 mpp_paths
->mean_chain_len
= MEAN_CHAIN_LEN
;
610 void mesh_path_expire(struct ieee80211_sub_if_data
*sdata
)
612 struct mesh_path
*mpath
;
613 struct mpath_node
*node
;
614 struct hlist_node
*p
;
617 read_lock(&pathtbl_resize_lock
);
618 for_each_mesh_entry(mesh_paths
, p
, node
, i
) {
619 if (node
->mpath
->sdata
!= sdata
)
622 spin_lock_bh(&mpath
->state_lock
);
623 if ((!(mpath
->flags
& MESH_PATH_RESOLVING
)) &&
624 (!(mpath
->flags
& MESH_PATH_FIXED
)) &&
626 mpath
->exp_time
+ MESH_PATH_EXPIRE
)) {
627 spin_unlock_bh(&mpath
->state_lock
);
628 mesh_path_del(mpath
->dst
, mpath
->sdata
);
630 spin_unlock_bh(&mpath
->state_lock
);
632 read_unlock(&pathtbl_resize_lock
);
635 void mesh_pathtbl_unregister(void)
637 mesh_table_free(mesh_paths
, true);
638 mesh_table_free(mpp_paths
, true);
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