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.
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"
20 #ifdef CONFIG_MAC80211_VERBOSE_MPATH_DEBUG
21 #define mpath_dbg(fmt, args...) printk(KERN_DEBUG fmt, ##args)
23 #define mpath_dbg(fmt, args...) do { (void)(0); } while (0)
26 /* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
27 #define INIT_PATHS_SIZE_ORDER 2
29 /* Keep the mean chain length below this constant */
30 #define MEAN_CHAIN_LEN 2
32 #define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \
33 time_after(jiffies, mpath->exp_time) && \
34 !(mpath->flags & MESH_PATH_FIXED))
37 struct hlist_node list;
39 /* This indirection allows two different tables to point to the same
40 * mesh_path structure, useful when resizing
42 struct mesh_path *mpath;
45 static struct mesh_table __rcu *mesh_paths;
46 static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
48 int mesh_paths_generation;
50 /* This lock will have the grow table function as writer and add / delete nodes
51 * as readers. RCU provides sufficient protection only when reading the table
52 * (i.e. doing lookups). Adding or adding or removing nodes requires we take
53 * the read lock or we risk operating on an old table. The write lock is only
54 * needed when modifying the number of buckets a table.
56 static DEFINE_RWLOCK(pathtbl_resize_lock);
59 static inline struct mesh_table *resize_dereference_mesh_paths(void)
61 return rcu_dereference_protected(mesh_paths,
62 lockdep_is_held(&pathtbl_resize_lock));
65 static inline struct mesh_table *resize_dereference_mpp_paths(void)
67 return rcu_dereference_protected(mpp_paths,
68 lockdep_is_held(&pathtbl_resize_lock));
71 static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath);
74 * CAREFUL -- "tbl" must not be an expression,
75 * in particular not an rcu_dereference(), since
76 * it's used twice. So it is illegal to do
77 * for_each_mesh_entry(rcu_dereference(...), ...)
79 #define for_each_mesh_entry(tbl, p, node, i) \
80 for (i = 0; i <= tbl->hash_mask; i++) \
81 hlist_for_each_entry_rcu(node, p, &tbl->hash_buckets[i], list)
84 static struct mesh_table *mesh_table_alloc(int size_order)
87 struct mesh_table *newtbl;
89 newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
93 newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
94 (1 << size_order), GFP_ATOMIC);
96 if (!newtbl->hash_buckets) {
101 newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
102 (1 << size_order), GFP_ATOMIC);
103 if (!newtbl->hashwlock) {
104 kfree(newtbl->hash_buckets);
109 newtbl->size_order = size_order;
110 newtbl->hash_mask = (1 << size_order) - 1;
111 atomic_set(&newtbl->entries, 0);
112 get_random_bytes(&newtbl->hash_rnd,
113 sizeof(newtbl->hash_rnd));
114 for (i = 0; i <= newtbl->hash_mask; i++)
115 spin_lock_init(&newtbl->hashwlock[i]);
116 spin_lock_init(&newtbl->gates_lock);
121 static void __mesh_table_free(struct mesh_table *tbl)
123 kfree(tbl->hash_buckets);
124 kfree(tbl->hashwlock);
128 static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
130 struct hlist_head *mesh_hash;
131 struct hlist_node *p, *q;
132 struct mpath_node *gate;
135 mesh_hash = tbl->hash_buckets;
136 for (i = 0; i <= tbl->hash_mask; i++) {
137 spin_lock_bh(&tbl->hashwlock[i]);
138 hlist_for_each_safe(p, q, &mesh_hash[i]) {
139 tbl->free_node(p, free_leafs);
140 atomic_dec(&tbl->entries);
142 spin_unlock_bh(&tbl->hashwlock[i]);
145 spin_lock_bh(&tbl->gates_lock);
146 hlist_for_each_entry_safe(gate, p, q,
147 tbl->known_gates, list) {
148 hlist_del(&gate->list);
151 kfree(tbl->known_gates);
152 spin_unlock_bh(&tbl->gates_lock);
155 __mesh_table_free(tbl);
158 static int mesh_table_grow(struct mesh_table *oldtbl,
159 struct mesh_table *newtbl)
161 struct hlist_head *oldhash;
162 struct hlist_node *p, *q;
165 if (atomic_read(&oldtbl->entries)
166 < oldtbl->mean_chain_len * (oldtbl->hash_mask + 1))
169 newtbl->free_node = oldtbl->free_node;
170 newtbl->mean_chain_len = oldtbl->mean_chain_len;
171 newtbl->copy_node = oldtbl->copy_node;
172 newtbl->known_gates = oldtbl->known_gates;
173 atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
175 oldhash = oldtbl->hash_buckets;
176 for (i = 0; i <= oldtbl->hash_mask; i++)
177 hlist_for_each(p, &oldhash[i])
178 if (oldtbl->copy_node(p, newtbl) < 0)
184 for (i = 0; i <= newtbl->hash_mask; i++) {
185 hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
186 oldtbl->free_node(p, 0);
191 static u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
192 struct mesh_table *tbl)
194 /* Use last four bytes of hw addr and interface index as hash index */
195 return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
202 * mesh_path_assign_nexthop - update mesh path next hop
204 * @mpath: mesh path to update
205 * @sta: next hop to assign
207 * Locking: mpath->state_lock must be held when calling this function
209 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
212 struct ieee80211_hdr *hdr;
213 struct sk_buff_head tmpq;
216 rcu_assign_pointer(mpath->next_hop, sta);
218 __skb_queue_head_init(&tmpq);
220 spin_lock_irqsave(&mpath->frame_queue.lock, flags);
222 while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
223 hdr = (struct ieee80211_hdr *) skb->data;
224 memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
225 __skb_queue_tail(&tmpq, skb);
228 skb_queue_splice(&tmpq, &mpath->frame_queue);
229 spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
232 static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
233 struct mesh_path *gate_mpath)
235 struct ieee80211_hdr *hdr;
236 struct ieee80211s_hdr *mshdr;
237 int mesh_hdrlen, hdrlen;
240 hdr = (struct ieee80211_hdr *) skb->data;
241 hdrlen = ieee80211_hdrlen(hdr->frame_control);
242 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
244 if (!(mshdr->flags & MESH_FLAGS_AE)) {
245 /* size of the fixed part of the mesh header */
248 /* make room for the two extended addresses */
249 skb_push(skb, 2 * ETH_ALEN);
250 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
252 hdr = (struct ieee80211_hdr *) skb->data;
254 /* we preserve the previous mesh header and only add
255 * the new addreses */
256 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
257 mshdr->flags = MESH_FLAGS_AE_A5_A6;
258 memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
259 memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
262 /* update next hop */
263 hdr = (struct ieee80211_hdr *) skb->data;
265 next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
266 memcpy(hdr->addr1, next_hop, ETH_ALEN);
268 memcpy(hdr->addr3, dst_addr, ETH_ALEN);
273 * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
275 * This function is used to transfer or copy frames from an unresolved mpath to
276 * a gate mpath. The function also adds the Address Extension field and
277 * updates the next hop.
279 * If a frame already has an Address Extension field, only the next hop and
280 * destination addresses are updated.
282 * The gate mpath must be an active mpath with a valid mpath->next_hop.
284 * @mpath: An active mpath the frames will be sent to (i.e. the gate)
285 * @from_mpath: The failed mpath
286 * @copy: When true, copy all the frames to the new mpath queue. When false,
289 static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
290 struct mesh_path *from_mpath,
293 struct sk_buff *skb, *cp_skb = NULL;
294 struct sk_buff_head gateq, failq;
298 BUG_ON(gate_mpath == from_mpath);
299 BUG_ON(!gate_mpath->next_hop);
301 __skb_queue_head_init(&gateq);
302 __skb_queue_head_init(&failq);
304 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
305 skb_queue_splice_init(&from_mpath->frame_queue, &failq);
306 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
308 num_skbs = skb_queue_len(&failq);
311 skb = __skb_dequeue(&failq);
313 cp_skb = skb_copy(skb, GFP_ATOMIC);
315 __skb_queue_tail(&failq, cp_skb);
318 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
319 __skb_queue_tail(&gateq, skb);
322 spin_lock_irqsave(&gate_mpath->frame_queue.lock, flags);
323 skb_queue_splice(&gateq, &gate_mpath->frame_queue);
324 mpath_dbg("Mpath queue for gate %pM has %d frames\n",
326 skb_queue_len(&gate_mpath->frame_queue));
327 spin_unlock_irqrestore(&gate_mpath->frame_queue.lock, flags);
332 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
333 skb_queue_splice(&failq, &from_mpath->frame_queue);
334 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
338 static struct mesh_path *path_lookup(struct mesh_table *tbl, u8 *dst,
339 struct ieee80211_sub_if_data *sdata)
341 struct mesh_path *mpath;
342 struct hlist_node *n;
343 struct hlist_head *bucket;
344 struct mpath_node *node;
346 bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
347 hlist_for_each_entry_rcu(node, n, bucket, list) {
349 if (mpath->sdata == sdata &&
350 memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
351 if (MPATH_EXPIRED(mpath)) {
352 spin_lock_bh(&mpath->state_lock);
353 mpath->flags &= ~MESH_PATH_ACTIVE;
354 spin_unlock_bh(&mpath->state_lock);
363 * mesh_path_lookup - look up a path in the mesh path table
364 * @dst: hardware address (ETH_ALEN length) of destination
365 * @sdata: local subif
367 * Returns: pointer to the mesh path structure, or NULL if not found
369 * Locking: must be called within a read rcu section.
371 struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
373 return path_lookup(rcu_dereference(mesh_paths), dst, sdata);
376 struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
378 return path_lookup(rcu_dereference(mpp_paths), dst, sdata);
383 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
385 * @sdata: local subif, or NULL for all entries
387 * Returns: pointer to the mesh path structure, or NULL if not found.
389 * Locking: must be called within a read rcu section.
391 struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data *sdata)
393 struct mesh_table *tbl = rcu_dereference(mesh_paths);
394 struct mpath_node *node;
395 struct hlist_node *p;
399 for_each_mesh_entry(tbl, p, node, i) {
400 if (sdata && node->mpath->sdata != sdata)
403 if (MPATH_EXPIRED(node->mpath)) {
404 spin_lock_bh(&node->mpath->state_lock);
405 node->mpath->flags &= ~MESH_PATH_ACTIVE;
406 spin_unlock_bh(&node->mpath->state_lock);
415 static void mesh_gate_node_reclaim(struct rcu_head *rp)
417 struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
422 * mesh_gate_add - mark mpath as path to a mesh gate and add to known_gates
423 * @mesh_tbl: table which contains known_gates list
424 * @mpath: mpath to known mesh gate
426 * Returns: 0 on success
429 static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath)
431 struct mpath_node *gate, *new_gate;
432 struct hlist_node *n;
436 tbl = rcu_dereference(tbl);
438 hlist_for_each_entry_rcu(gate, n, tbl->known_gates, list)
439 if (gate->mpath == mpath) {
444 new_gate = kzalloc(sizeof(struct mpath_node), GFP_ATOMIC);
450 mpath->is_gate = true;
451 mpath->sdata->u.mesh.num_gates++;
452 new_gate->mpath = mpath;
453 spin_lock_bh(&tbl->gates_lock);
454 hlist_add_head_rcu(&new_gate->list, tbl->known_gates);
455 spin_unlock_bh(&tbl->gates_lock);
457 mpath_dbg("Mesh path (%s): Recorded new gate: %pM. %d known gates\n",
458 mpath->sdata->name, mpath->dst,
459 mpath->sdata->u.mesh.num_gates);
467 * mesh_gate_del - remove a mesh gate from the list of known gates
468 * @tbl: table which holds our list of known gates
471 * Returns: 0 on success
473 * Locking: must be called inside rcu_read_lock() section
475 static int mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
477 struct mpath_node *gate;
478 struct hlist_node *p, *q;
480 tbl = rcu_dereference(tbl);
482 hlist_for_each_entry_safe(gate, p, q, tbl->known_gates, list)
483 if (gate->mpath == mpath) {
484 spin_lock_bh(&tbl->gates_lock);
485 hlist_del_rcu(&gate->list);
486 call_rcu(&gate->rcu, mesh_gate_node_reclaim);
487 spin_unlock_bh(&tbl->gates_lock);
488 mpath->sdata->u.mesh.num_gates--;
489 mpath->is_gate = false;
490 mpath_dbg("Mesh path (%s): Deleted gate: %pM. "
491 "%d known gates\n", mpath->sdata->name,
492 mpath->dst, mpath->sdata->u.mesh.num_gates);
501 * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
502 * @mpath: gate path to add to table
504 int mesh_path_add_gate(struct mesh_path *mpath)
506 return mesh_gate_add(mesh_paths, mpath);
510 * mesh_gate_num - number of gates known to this interface
513 int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
515 return sdata->u.mesh.num_gates;
519 * mesh_path_add - allocate and add a new path to the mesh path table
520 * @addr: destination address of the path (ETH_ALEN length)
521 * @sdata: local subif
523 * Returns: 0 on success
525 * State: the initial state of the new path is set to 0
527 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata)
529 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
530 struct ieee80211_local *local = sdata->local;
531 struct mesh_table *tbl;
532 struct mesh_path *mpath, *new_mpath;
533 struct mpath_node *node, *new_node;
534 struct hlist_head *bucket;
535 struct hlist_node *n;
540 if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
541 /* never add ourselves as neighbours */
544 if (is_multicast_ether_addr(dst))
547 if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
551 new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
555 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
559 read_lock_bh(&pathtbl_resize_lock);
560 memcpy(new_mpath->dst, dst, ETH_ALEN);
561 new_mpath->sdata = sdata;
562 new_mpath->flags = 0;
563 skb_queue_head_init(&new_mpath->frame_queue);
564 new_node->mpath = new_mpath;
565 new_mpath->timer.data = (unsigned long) new_mpath;
566 new_mpath->timer.function = mesh_path_timer;
567 new_mpath->exp_time = jiffies;
568 spin_lock_init(&new_mpath->state_lock);
569 init_timer(&new_mpath->timer);
571 tbl = resize_dereference_mesh_paths();
573 hash_idx = mesh_table_hash(dst, sdata, tbl);
574 bucket = &tbl->hash_buckets[hash_idx];
576 spin_lock_bh(&tbl->hashwlock[hash_idx]);
579 hlist_for_each_entry(node, n, bucket, list) {
581 if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
585 hlist_add_head_rcu(&new_node->list, bucket);
586 if (atomic_inc_return(&tbl->entries) >=
587 tbl->mean_chain_len * (tbl->hash_mask + 1))
590 mesh_paths_generation++;
592 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
593 read_unlock_bh(&pathtbl_resize_lock);
595 set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags);
596 ieee80211_queue_work(&local->hw, &sdata->work);
601 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
602 read_unlock_bh(&pathtbl_resize_lock);
607 atomic_dec(&sdata->u.mesh.mpaths);
611 static void mesh_table_free_rcu(struct rcu_head *rcu)
613 struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head);
615 mesh_table_free(tbl, false);
618 void mesh_mpath_table_grow(void)
620 struct mesh_table *oldtbl, *newtbl;
622 write_lock_bh(&pathtbl_resize_lock);
623 oldtbl = resize_dereference_mesh_paths();
624 newtbl = mesh_table_alloc(oldtbl->size_order + 1);
627 if (mesh_table_grow(oldtbl, newtbl) < 0) {
628 __mesh_table_free(newtbl);
631 rcu_assign_pointer(mesh_paths, newtbl);
633 call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
636 write_unlock_bh(&pathtbl_resize_lock);
639 void mesh_mpp_table_grow(void)
641 struct mesh_table *oldtbl, *newtbl;
643 write_lock_bh(&pathtbl_resize_lock);
644 oldtbl = resize_dereference_mpp_paths();
645 newtbl = mesh_table_alloc(oldtbl->size_order + 1);
648 if (mesh_table_grow(oldtbl, newtbl) < 0) {
649 __mesh_table_free(newtbl);
652 rcu_assign_pointer(mpp_paths, newtbl);
653 call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
656 write_unlock_bh(&pathtbl_resize_lock);
659 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
661 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
662 struct ieee80211_local *local = sdata->local;
663 struct mesh_table *tbl;
664 struct mesh_path *mpath, *new_mpath;
665 struct mpath_node *node, *new_node;
666 struct hlist_head *bucket;
667 struct hlist_node *n;
672 if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
673 /* never add ourselves as neighbours */
676 if (is_multicast_ether_addr(dst))
680 new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
684 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
688 read_lock_bh(&pathtbl_resize_lock);
689 memcpy(new_mpath->dst, dst, ETH_ALEN);
690 memcpy(new_mpath->mpp, mpp, ETH_ALEN);
691 new_mpath->sdata = sdata;
692 new_mpath->flags = 0;
693 skb_queue_head_init(&new_mpath->frame_queue);
694 new_node->mpath = new_mpath;
695 init_timer(&new_mpath->timer);
696 new_mpath->exp_time = jiffies;
697 spin_lock_init(&new_mpath->state_lock);
699 tbl = resize_dereference_mpp_paths();
701 hash_idx = mesh_table_hash(dst, sdata, tbl);
702 bucket = &tbl->hash_buckets[hash_idx];
704 spin_lock_bh(&tbl->hashwlock[hash_idx]);
707 hlist_for_each_entry(node, n, bucket, list) {
709 if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
713 hlist_add_head_rcu(&new_node->list, bucket);
714 if (atomic_inc_return(&tbl->entries) >=
715 tbl->mean_chain_len * (tbl->hash_mask + 1))
718 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
719 read_unlock_bh(&pathtbl_resize_lock);
721 set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags);
722 ieee80211_queue_work(&local->hw, &sdata->work);
727 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
728 read_unlock_bh(&pathtbl_resize_lock);
738 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
740 * @sta: broken peer link
742 * This function must be called from the rate control algorithm if enough
743 * delivery errors suggest that a peer link is no longer usable.
745 void mesh_plink_broken(struct sta_info *sta)
747 struct mesh_table *tbl;
748 static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
749 struct mesh_path *mpath;
750 struct mpath_node *node;
751 struct hlist_node *p;
752 struct ieee80211_sub_if_data *sdata = sta->sdata;
754 __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_DEST_UNREACHABLE);
757 tbl = rcu_dereference(mesh_paths);
758 for_each_mesh_entry(tbl, p, node, i) {
760 if (rcu_dereference(mpath->next_hop) == sta &&
761 mpath->flags & MESH_PATH_ACTIVE &&
762 !(mpath->flags & MESH_PATH_FIXED)) {
763 spin_lock_bh(&mpath->state_lock);
764 mpath->flags &= ~MESH_PATH_ACTIVE;
766 spin_unlock_bh(&mpath->state_lock);
767 mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
768 mpath->dst, cpu_to_le32(mpath->sn),
769 reason, bcast, sdata);
775 static void mesh_path_node_reclaim(struct rcu_head *rp)
777 struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
778 struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
780 del_timer_sync(&node->mpath->timer);
781 atomic_dec(&sdata->u.mesh.mpaths);
786 /* needs to be called with the corresponding hashwlock taken */
787 static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
789 struct mesh_path *mpath;
791 spin_lock(&mpath->state_lock);
792 mpath->flags |= MESH_PATH_RESOLVING;
794 mesh_gate_del(tbl, mpath);
795 hlist_del_rcu(&node->list);
796 call_rcu(&node->rcu, mesh_path_node_reclaim);
797 spin_unlock(&mpath->state_lock);
798 atomic_dec(&tbl->entries);
802 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
804 * @sta - mesh peer to match
806 * RCU notes: this function is called when a mesh plink transitions from
807 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
808 * allows path creation. This will happen before the sta can be freed (because
809 * sta_info_destroy() calls this) so any reader in a rcu read block will be
810 * protected against the plink disappearing.
812 void mesh_path_flush_by_nexthop(struct sta_info *sta)
814 struct mesh_table *tbl;
815 struct mesh_path *mpath;
816 struct mpath_node *node;
817 struct hlist_node *p;
821 read_lock_bh(&pathtbl_resize_lock);
822 tbl = resize_dereference_mesh_paths();
823 for_each_mesh_entry(tbl, p, node, i) {
825 if (rcu_dereference(mpath->next_hop) == sta) {
826 spin_lock_bh(&tbl->hashwlock[i]);
827 __mesh_path_del(tbl, node);
828 spin_unlock_bh(&tbl->hashwlock[i]);
831 read_unlock_bh(&pathtbl_resize_lock);
835 static void table_flush_by_iface(struct mesh_table *tbl,
836 struct ieee80211_sub_if_data *sdata)
838 struct mesh_path *mpath;
839 struct mpath_node *node;
840 struct hlist_node *p;
843 WARN_ON(!rcu_read_lock_held());
844 for_each_mesh_entry(tbl, p, node, i) {
846 if (mpath->sdata != sdata)
848 spin_lock_bh(&tbl->hashwlock[i]);
849 __mesh_path_del(tbl, node);
850 spin_unlock_bh(&tbl->hashwlock[i]);
855 * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
857 * This function deletes both mesh paths as well as mesh portal paths.
859 * @sdata - interface data to match
862 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
864 struct mesh_table *tbl;
867 read_lock_bh(&pathtbl_resize_lock);
868 tbl = resize_dereference_mesh_paths();
869 table_flush_by_iface(tbl, sdata);
870 tbl = resize_dereference_mpp_paths();
871 table_flush_by_iface(tbl, sdata);
872 read_unlock_bh(&pathtbl_resize_lock);
877 * mesh_path_del - delete a mesh path from the table
879 * @addr: dst address (ETH_ALEN length)
880 * @sdata: local subif
882 * Returns: 0 if successful
884 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
886 struct mesh_table *tbl;
887 struct mesh_path *mpath;
888 struct mpath_node *node;
889 struct hlist_head *bucket;
890 struct hlist_node *n;
894 read_lock_bh(&pathtbl_resize_lock);
895 tbl = resize_dereference_mesh_paths();
896 hash_idx = mesh_table_hash(addr, sdata, tbl);
897 bucket = &tbl->hash_buckets[hash_idx];
899 spin_lock_bh(&tbl->hashwlock[hash_idx]);
900 hlist_for_each_entry(node, n, bucket, list) {
902 if (mpath->sdata == sdata &&
903 memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
904 __mesh_path_del(tbl, node);
911 mesh_paths_generation++;
912 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
913 read_unlock_bh(&pathtbl_resize_lock);
918 * mesh_path_tx_pending - sends pending frames in a mesh path queue
920 * @mpath: mesh path to activate
922 * Locking: the state_lock of the mpath structure must NOT be held when calling
925 void mesh_path_tx_pending(struct mesh_path *mpath)
927 if (mpath->flags & MESH_PATH_ACTIVE)
928 ieee80211_add_pending_skbs(mpath->sdata->local,
929 &mpath->frame_queue);
933 * mesh_path_send_to_gates - sends pending frames to all known mesh gates
935 * @mpath: mesh path whose queue will be emptied
937 * If there is only one gate, the frames are transferred from the failed mpath
938 * queue to that gate's queue. If there are more than one gates, the frames
939 * are copied from each gate to the next. After frames are copied, the
940 * mpath queues are emptied onto the transmission queue.
942 int mesh_path_send_to_gates(struct mesh_path *mpath)
944 struct ieee80211_sub_if_data *sdata = mpath->sdata;
945 struct hlist_node *n;
946 struct mesh_table *tbl;
947 struct mesh_path *from_mpath = mpath;
948 struct mpath_node *gate = NULL;
950 struct hlist_head *known_gates;
953 tbl = rcu_dereference(mesh_paths);
954 known_gates = tbl->known_gates;
958 return -EHOSTUNREACH;
960 hlist_for_each_entry_rcu(gate, n, known_gates, list) {
961 if (gate->mpath->sdata != sdata)
964 if (gate->mpath->flags & MESH_PATH_ACTIVE) {
965 mpath_dbg("Forwarding to %pM\n", gate->mpath->dst);
966 mesh_path_move_to_queue(gate->mpath, from_mpath, copy);
967 from_mpath = gate->mpath;
970 mpath_dbg("Not forwarding %p\n", gate->mpath);
971 mpath_dbg("flags %x\n", gate->mpath->flags);
975 hlist_for_each_entry_rcu(gate, n, known_gates, list)
976 if (gate->mpath->sdata == sdata) {
977 mpath_dbg("Sending to %pM\n", gate->mpath->dst);
978 mesh_path_tx_pending(gate->mpath);
981 return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
985 * mesh_path_discard_frame - discard a frame whose path could not be resolved
987 * @skb: frame to discard
988 * @sdata: network subif the frame was to be sent through
990 * If the frame was being forwarded from another MP, a PERR frame will be sent
991 * to the precursor. The precursor's address (i.e. the previous hop) was saved
992 * in addr1 of the frame-to-be-forwarded, and would only be overwritten once
993 * the destination is successfully resolved.
995 * Locking: the function must me called within a rcu_read_lock region
997 void mesh_path_discard_frame(struct sk_buff *skb,
998 struct ieee80211_sub_if_data *sdata)
1000 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1001 struct mesh_path *mpath;
1003 __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
1005 if (memcmp(hdr->addr4, sdata->vif.addr, ETH_ALEN) != 0) {
1011 mpath = mesh_path_lookup(da, sdata);
1013 spin_lock_bh(&mpath->state_lock);
1015 spin_unlock_bh(&mpath->state_lock);
1018 mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
1019 cpu_to_le32(sn), reason, ra, sdata);
1023 sdata->u.mesh.mshstats.dropped_frames_no_route++;
1027 * mesh_path_flush_pending - free the pending queue of a mesh path
1029 * @mpath: mesh path whose queue has to be freed
1031 * Locking: the function must me called within a rcu_read_lock region
1033 void mesh_path_flush_pending(struct mesh_path *mpath)
1035 struct sk_buff *skb;
1037 while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
1038 mesh_path_discard_frame(skb, mpath->sdata);
1042 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
1044 * @mpath: the mesh path to modify
1045 * @next_hop: the next hop to force
1047 * Locking: this function must be called holding mpath->state_lock
1049 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
1051 spin_lock_bh(&mpath->state_lock);
1052 mesh_path_assign_nexthop(mpath, next_hop);
1055 mpath->hop_count = 0;
1056 mpath->exp_time = 0;
1057 mpath->flags |= MESH_PATH_FIXED;
1058 mesh_path_activate(mpath);
1059 spin_unlock_bh(&mpath->state_lock);
1060 mesh_path_tx_pending(mpath);
1063 static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
1065 struct mesh_path *mpath;
1066 struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
1067 mpath = node->mpath;
1070 del_timer_sync(&mpath->timer);
1076 static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
1078 struct mesh_path *mpath;
1079 struct mpath_node *node, *new_node;
1082 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
1083 if (new_node == NULL)
1086 node = hlist_entry(p, struct mpath_node, list);
1087 mpath = node->mpath;
1088 new_node->mpath = mpath;
1089 hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl);
1090 hlist_add_head(&new_node->list,
1091 &newtbl->hash_buckets[hash_idx]);
1095 int mesh_pathtbl_init(void)
1097 struct mesh_table *tbl_path, *tbl_mpp;
1100 tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
1103 tbl_path->free_node = &mesh_path_node_free;
1104 tbl_path->copy_node = &mesh_path_node_copy;
1105 tbl_path->mean_chain_len = MEAN_CHAIN_LEN;
1106 tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
1107 if (!tbl_path->known_gates) {
1111 INIT_HLIST_HEAD(tbl_path->known_gates);
1114 tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
1119 tbl_mpp->free_node = &mesh_path_node_free;
1120 tbl_mpp->copy_node = &mesh_path_node_copy;
1121 tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN;
1122 tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
1123 if (!tbl_mpp->known_gates) {
1127 INIT_HLIST_HEAD(tbl_mpp->known_gates);
1129 /* Need no locking since this is during init */
1130 RCU_INIT_POINTER(mesh_paths, tbl_path);
1131 RCU_INIT_POINTER(mpp_paths, tbl_mpp);
1136 mesh_table_free(tbl_mpp, true);
1138 mesh_table_free(tbl_path, true);
1142 void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
1144 struct mesh_table *tbl;
1145 struct mesh_path *mpath;
1146 struct mpath_node *node;
1147 struct hlist_node *p;
1151 tbl = rcu_dereference(mesh_paths);
1152 for_each_mesh_entry(tbl, p, node, i) {
1153 if (node->mpath->sdata != sdata)
1155 mpath = node->mpath;
1156 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
1157 (!(mpath->flags & MESH_PATH_FIXED)) &&
1158 time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
1159 mesh_path_del(mpath->dst, mpath->sdata);
1164 void mesh_pathtbl_unregister(void)
1166 /* no need for locking during exit path */
1167 mesh_table_free(rcu_dereference_raw(mesh_paths), true);
1168 mesh_table_free(rcu_dereference_raw(mpp_paths), true);