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. When reading the table (i.e. doing lookups) we are well protected
54 static DEFINE_RWLOCK(pathtbl_resize_lock);
57 static inline struct mesh_table *resize_dereference_mesh_paths(void)
59 return rcu_dereference_protected(mesh_paths,
60 lockdep_is_held(&pathtbl_resize_lock));
63 static inline struct mesh_table *resize_dereference_mpp_paths(void)
65 return rcu_dereference_protected(mpp_paths,
66 lockdep_is_held(&pathtbl_resize_lock));
69 static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath);
72 * CAREFUL -- "tbl" must not be an expression,
73 * in particular not an rcu_dereference(), since
74 * it's used twice. So it is illegal to do
75 * for_each_mesh_entry(rcu_dereference(...), ...)
77 #define for_each_mesh_entry(tbl, p, node, i) \
78 for (i = 0; i <= tbl->hash_mask; i++) \
79 hlist_for_each_entry_rcu(node, p, &tbl->hash_buckets[i], list)
82 static struct mesh_table *mesh_table_alloc(int size_order)
85 struct mesh_table *newtbl;
87 newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
91 newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
92 (1 << size_order), GFP_ATOMIC);
94 if (!newtbl->hash_buckets) {
99 newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
100 (1 << size_order), GFP_ATOMIC);
101 if (!newtbl->hashwlock) {
102 kfree(newtbl->hash_buckets);
107 newtbl->size_order = size_order;
108 newtbl->hash_mask = (1 << size_order) - 1;
109 atomic_set(&newtbl->entries, 0);
110 get_random_bytes(&newtbl->hash_rnd,
111 sizeof(newtbl->hash_rnd));
112 for (i = 0; i <= newtbl->hash_mask; i++)
113 spin_lock_init(&newtbl->hashwlock[i]);
114 spin_lock_init(&newtbl->gates_lock);
119 static void __mesh_table_free(struct mesh_table *tbl)
121 kfree(tbl->hash_buckets);
122 kfree(tbl->hashwlock);
126 static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
128 struct hlist_head *mesh_hash;
129 struct hlist_node *p, *q;
130 struct mpath_node *gate;
133 mesh_hash = tbl->hash_buckets;
134 for (i = 0; i <= tbl->hash_mask; i++) {
135 spin_lock_bh(&tbl->hashwlock[i]);
136 hlist_for_each_safe(p, q, &mesh_hash[i]) {
137 tbl->free_node(p, free_leafs);
138 atomic_dec(&tbl->entries);
140 spin_unlock_bh(&tbl->hashwlock[i]);
143 spin_lock_bh(&tbl->gates_lock);
144 hlist_for_each_entry_safe(gate, p, q,
145 tbl->known_gates, list) {
146 hlist_del(&gate->list);
149 kfree(tbl->known_gates);
150 spin_unlock_bh(&tbl->gates_lock);
153 __mesh_table_free(tbl);
156 static int mesh_table_grow(struct mesh_table *oldtbl,
157 struct mesh_table *newtbl)
159 struct hlist_head *oldhash;
160 struct hlist_node *p, *q;
163 if (atomic_read(&oldtbl->entries)
164 < oldtbl->mean_chain_len * (oldtbl->hash_mask + 1))
167 newtbl->free_node = oldtbl->free_node;
168 newtbl->mean_chain_len = oldtbl->mean_chain_len;
169 newtbl->copy_node = oldtbl->copy_node;
170 newtbl->known_gates = oldtbl->known_gates;
171 atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
173 oldhash = oldtbl->hash_buckets;
174 for (i = 0; i <= oldtbl->hash_mask; i++)
175 hlist_for_each(p, &oldhash[i])
176 if (oldtbl->copy_node(p, newtbl) < 0)
182 for (i = 0; i <= newtbl->hash_mask; i++) {
183 hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
184 oldtbl->free_node(p, 0);
189 static u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
190 struct mesh_table *tbl)
192 /* Use last four bytes of hw addr and interface index as hash index */
193 return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
200 * mesh_path_assign_nexthop - update mesh path next hop
202 * @mpath: mesh path to update
203 * @sta: next hop to assign
205 * Locking: mpath->state_lock must be held when calling this function
207 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
210 struct ieee80211_hdr *hdr;
211 struct sk_buff_head tmpq;
214 rcu_assign_pointer(mpath->next_hop, sta);
216 __skb_queue_head_init(&tmpq);
218 spin_lock_irqsave(&mpath->frame_queue.lock, flags);
220 while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
221 hdr = (struct ieee80211_hdr *) skb->data;
222 memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
223 __skb_queue_tail(&tmpq, skb);
226 skb_queue_splice(&tmpq, &mpath->frame_queue);
227 spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
230 static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
231 struct mesh_path *gate_mpath)
233 struct ieee80211_hdr *hdr;
234 struct ieee80211s_hdr *mshdr;
235 int mesh_hdrlen, hdrlen;
238 hdr = (struct ieee80211_hdr *) skb->data;
239 hdrlen = ieee80211_hdrlen(hdr->frame_control);
240 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
242 if (!(mshdr->flags & MESH_FLAGS_AE)) {
243 /* size of the fixed part of the mesh header */
246 /* make room for the two extended addresses */
247 skb_push(skb, 2 * ETH_ALEN);
248 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
250 hdr = (struct ieee80211_hdr *) skb->data;
252 /* we preserve the previous mesh header and only add
253 * the new addreses */
254 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
255 mshdr->flags = MESH_FLAGS_AE_A5_A6;
256 memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
257 memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
260 /* update next hop */
261 hdr = (struct ieee80211_hdr *) skb->data;
263 next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
264 memcpy(hdr->addr1, next_hop, ETH_ALEN);
266 memcpy(hdr->addr3, dst_addr, ETH_ALEN);
271 * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
273 * This function is used to transfer or copy frames from an unresolved mpath to
274 * a gate mpath. The function also adds the Address Extension field and
275 * updates the next hop.
277 * If a frame already has an Address Extension field, only the next hop and
278 * destination addresses are updated.
280 * The gate mpath must be an active mpath with a valid mpath->next_hop.
282 * @mpath: An active mpath the frames will be sent to (i.e. the gate)
283 * @from_mpath: The failed mpath
284 * @copy: When true, copy all the frames to the new mpath queue. When false,
287 static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
288 struct mesh_path *from_mpath,
291 struct sk_buff *skb, *cp_skb = NULL;
292 struct sk_buff_head gateq, failq;
296 BUG_ON(gate_mpath == from_mpath);
297 BUG_ON(!gate_mpath->next_hop);
299 __skb_queue_head_init(&gateq);
300 __skb_queue_head_init(&failq);
302 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
303 skb_queue_splice_init(&from_mpath->frame_queue, &failq);
304 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
306 num_skbs = skb_queue_len(&failq);
309 skb = __skb_dequeue(&failq);
311 cp_skb = skb_copy(skb, GFP_ATOMIC);
313 __skb_queue_tail(&failq, cp_skb);
316 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
317 __skb_queue_tail(&gateq, skb);
320 spin_lock_irqsave(&gate_mpath->frame_queue.lock, flags);
321 skb_queue_splice(&gateq, &gate_mpath->frame_queue);
322 mpath_dbg("Mpath queue for gate %pM has %d frames\n",
324 skb_queue_len(&gate_mpath->frame_queue));
325 spin_unlock_irqrestore(&gate_mpath->frame_queue.lock, flags);
330 spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
331 skb_queue_splice(&failq, &from_mpath->frame_queue);
332 spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
337 * mesh_path_lookup - look up a path in the mesh path table
338 * @dst: hardware address (ETH_ALEN length) of destination
339 * @sdata: local subif
341 * Returns: pointer to the mesh path structure, or NULL if not found
343 * Locking: must be called within a read rcu section.
345 struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
347 struct mesh_path *mpath;
348 struct hlist_node *n;
349 struct hlist_head *bucket;
350 struct mesh_table *tbl;
351 struct mpath_node *node;
353 tbl = rcu_dereference(mesh_paths);
355 bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
356 hlist_for_each_entry_rcu(node, n, bucket, list) {
358 if (mpath->sdata == sdata &&
359 memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
360 if (MPATH_EXPIRED(mpath)) {
361 spin_lock_bh(&mpath->state_lock);
362 if (MPATH_EXPIRED(mpath))
363 mpath->flags &= ~MESH_PATH_ACTIVE;
364 spin_unlock_bh(&mpath->state_lock);
372 struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
374 struct mesh_path *mpath;
375 struct hlist_node *n;
376 struct hlist_head *bucket;
377 struct mesh_table *tbl;
378 struct mpath_node *node;
380 tbl = rcu_dereference(mpp_paths);
382 bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
383 hlist_for_each_entry_rcu(node, n, bucket, list) {
385 if (mpath->sdata == sdata &&
386 memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
387 if (MPATH_EXPIRED(mpath)) {
388 spin_lock_bh(&mpath->state_lock);
389 if (MPATH_EXPIRED(mpath))
390 mpath->flags &= ~MESH_PATH_ACTIVE;
391 spin_unlock_bh(&mpath->state_lock);
401 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
403 * @sdata: local subif, or NULL for all entries
405 * Returns: pointer to the mesh path structure, or NULL if not found.
407 * Locking: must be called within a read rcu section.
409 struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data *sdata)
411 struct mesh_table *tbl = rcu_dereference(mesh_paths);
412 struct mpath_node *node;
413 struct hlist_node *p;
417 for_each_mesh_entry(tbl, p, node, i) {
418 if (sdata && node->mpath->sdata != sdata)
421 if (MPATH_EXPIRED(node->mpath)) {
422 spin_lock_bh(&node->mpath->state_lock);
423 if (MPATH_EXPIRED(node->mpath))
424 node->mpath->flags &= ~MESH_PATH_ACTIVE;
425 spin_unlock_bh(&node->mpath->state_lock);
434 static void mesh_gate_node_reclaim(struct rcu_head *rp)
436 struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
441 * mesh_gate_add - mark mpath as path to a mesh gate and add to known_gates
442 * @mesh_tbl: table which contains known_gates list
443 * @mpath: mpath to known mesh gate
445 * Returns: 0 on success
448 static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath)
450 struct mpath_node *gate, *new_gate;
451 struct hlist_node *n;
455 tbl = rcu_dereference(tbl);
457 hlist_for_each_entry_rcu(gate, n, tbl->known_gates, list)
458 if (gate->mpath == mpath) {
463 new_gate = kzalloc(sizeof(struct mpath_node), GFP_ATOMIC);
469 mpath->is_gate = true;
470 mpath->sdata->u.mesh.num_gates++;
471 new_gate->mpath = mpath;
472 spin_lock_bh(&tbl->gates_lock);
473 hlist_add_head_rcu(&new_gate->list, tbl->known_gates);
474 spin_unlock_bh(&tbl->gates_lock);
476 mpath_dbg("Mesh path (%s): Recorded new gate: %pM. %d known gates\n",
477 mpath->sdata->name, mpath->dst,
478 mpath->sdata->u.mesh.num_gates);
486 * mesh_gate_del - remove a mesh gate from the list of known gates
487 * @tbl: table which holds our list of known gates
490 * Returns: 0 on success
492 * Locking: must be called inside rcu_read_lock() section
494 static int mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
496 struct mpath_node *gate;
497 struct hlist_node *p, *q;
499 tbl = rcu_dereference(tbl);
501 hlist_for_each_entry_safe(gate, p, q, tbl->known_gates, list)
502 if (gate->mpath == mpath) {
503 spin_lock_bh(&tbl->gates_lock);
504 hlist_del_rcu(&gate->list);
505 call_rcu(&gate->rcu, mesh_gate_node_reclaim);
506 spin_unlock_bh(&tbl->gates_lock);
507 mpath->sdata->u.mesh.num_gates--;
508 mpath->is_gate = false;
509 mpath_dbg("Mesh path (%s): Deleted gate: %pM. "
510 "%d known gates\n", mpath->sdata->name,
511 mpath->dst, mpath->sdata->u.mesh.num_gates);
520 * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
521 * @mpath: gate path to add to table
523 int mesh_path_add_gate(struct mesh_path *mpath)
525 return mesh_gate_add(mesh_paths, mpath);
529 * mesh_gate_num - number of gates known to this interface
532 int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
534 return sdata->u.mesh.num_gates;
538 * mesh_path_add - allocate and add a new path to the mesh path table
539 * @addr: destination address of the path (ETH_ALEN length)
540 * @sdata: local subif
542 * Returns: 0 on success
544 * State: the initial state of the new path is set to 0
546 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata)
548 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
549 struct ieee80211_local *local = sdata->local;
550 struct mesh_table *tbl;
551 struct mesh_path *mpath, *new_mpath;
552 struct mpath_node *node, *new_node;
553 struct hlist_head *bucket;
554 struct hlist_node *n;
559 if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
560 /* never add ourselves as neighbours */
563 if (is_multicast_ether_addr(dst))
566 if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
570 new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
574 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
578 read_lock_bh(&pathtbl_resize_lock);
579 memcpy(new_mpath->dst, dst, ETH_ALEN);
580 new_mpath->sdata = sdata;
581 new_mpath->flags = 0;
582 skb_queue_head_init(&new_mpath->frame_queue);
583 new_node->mpath = new_mpath;
584 new_mpath->timer.data = (unsigned long) new_mpath;
585 new_mpath->timer.function = mesh_path_timer;
586 new_mpath->exp_time = jiffies;
587 spin_lock_init(&new_mpath->state_lock);
588 init_timer(&new_mpath->timer);
590 tbl = resize_dereference_mesh_paths();
592 hash_idx = mesh_table_hash(dst, sdata, tbl);
593 bucket = &tbl->hash_buckets[hash_idx];
595 spin_lock_bh(&tbl->hashwlock[hash_idx]);
598 hlist_for_each_entry(node, n, bucket, list) {
600 if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
604 hlist_add_head_rcu(&new_node->list, bucket);
605 if (atomic_inc_return(&tbl->entries) >=
606 tbl->mean_chain_len * (tbl->hash_mask + 1))
609 mesh_paths_generation++;
611 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
612 read_unlock_bh(&pathtbl_resize_lock);
614 set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags);
615 ieee80211_queue_work(&local->hw, &sdata->work);
620 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
621 read_unlock_bh(&pathtbl_resize_lock);
626 atomic_dec(&sdata->u.mesh.mpaths);
630 static void mesh_table_free_rcu(struct rcu_head *rcu)
632 struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head);
634 mesh_table_free(tbl, false);
637 void mesh_mpath_table_grow(void)
639 struct mesh_table *oldtbl, *newtbl;
641 write_lock_bh(&pathtbl_resize_lock);
642 oldtbl = resize_dereference_mesh_paths();
643 newtbl = mesh_table_alloc(oldtbl->size_order + 1);
646 if (mesh_table_grow(oldtbl, newtbl) < 0) {
647 __mesh_table_free(newtbl);
650 rcu_assign_pointer(mesh_paths, newtbl);
652 call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
655 write_unlock_bh(&pathtbl_resize_lock);
658 void mesh_mpp_table_grow(void)
660 struct mesh_table *oldtbl, *newtbl;
662 write_lock_bh(&pathtbl_resize_lock);
663 oldtbl = resize_dereference_mpp_paths();
664 newtbl = mesh_table_alloc(oldtbl->size_order + 1);
667 if (mesh_table_grow(oldtbl, newtbl) < 0) {
668 __mesh_table_free(newtbl);
671 rcu_assign_pointer(mpp_paths, newtbl);
672 call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
675 write_unlock_bh(&pathtbl_resize_lock);
678 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
680 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
681 struct ieee80211_local *local = sdata->local;
682 struct mesh_table *tbl;
683 struct mesh_path *mpath, *new_mpath;
684 struct mpath_node *node, *new_node;
685 struct hlist_head *bucket;
686 struct hlist_node *n;
691 if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
692 /* never add ourselves as neighbours */
695 if (is_multicast_ether_addr(dst))
699 new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
703 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
707 read_lock_bh(&pathtbl_resize_lock);
708 memcpy(new_mpath->dst, dst, ETH_ALEN);
709 memcpy(new_mpath->mpp, mpp, ETH_ALEN);
710 new_mpath->sdata = sdata;
711 new_mpath->flags = 0;
712 skb_queue_head_init(&new_mpath->frame_queue);
713 new_node->mpath = new_mpath;
714 init_timer(&new_mpath->timer);
715 new_mpath->exp_time = jiffies;
716 spin_lock_init(&new_mpath->state_lock);
718 tbl = resize_dereference_mpp_paths();
720 hash_idx = mesh_table_hash(dst, sdata, tbl);
721 bucket = &tbl->hash_buckets[hash_idx];
723 spin_lock_bh(&tbl->hashwlock[hash_idx]);
726 hlist_for_each_entry(node, n, bucket, list) {
728 if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
732 hlist_add_head_rcu(&new_node->list, bucket);
733 if (atomic_inc_return(&tbl->entries) >=
734 tbl->mean_chain_len * (tbl->hash_mask + 1))
737 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
738 read_unlock_bh(&pathtbl_resize_lock);
740 set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags);
741 ieee80211_queue_work(&local->hw, &sdata->work);
746 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
747 read_unlock_bh(&pathtbl_resize_lock);
757 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
759 * @sta: broken peer link
761 * This function must be called from the rate control algorithm if enough
762 * delivery errors suggest that a peer link is no longer usable.
764 void mesh_plink_broken(struct sta_info *sta)
766 struct mesh_table *tbl;
767 static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
768 struct mesh_path *mpath;
769 struct mpath_node *node;
770 struct hlist_node *p;
771 struct ieee80211_sub_if_data *sdata = sta->sdata;
773 __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_DEST_UNREACHABLE);
776 tbl = rcu_dereference(mesh_paths);
777 for_each_mesh_entry(tbl, p, node, i) {
779 spin_lock_bh(&mpath->state_lock);
780 if (rcu_dereference(mpath->next_hop) == sta &&
781 mpath->flags & MESH_PATH_ACTIVE &&
782 !(mpath->flags & MESH_PATH_FIXED)) {
783 mpath->flags &= ~MESH_PATH_ACTIVE;
785 spin_unlock_bh(&mpath->state_lock);
786 mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
787 mpath->dst, cpu_to_le32(mpath->sn),
788 reason, bcast, sdata);
790 spin_unlock_bh(&mpath->state_lock);
796 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
798 * @sta - mesh peer to match
800 * RCU notes: this function is called when a mesh plink transitions from
801 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
802 * allows path creation. This will happen before the sta can be freed (because
803 * sta_info_destroy() calls this) so any reader in a rcu read block will be
804 * protected against the plink disappearing.
806 void mesh_path_flush_by_nexthop(struct sta_info *sta)
808 struct mesh_table *tbl;
809 struct mesh_path *mpath;
810 struct mpath_node *node;
811 struct hlist_node *p;
815 tbl = rcu_dereference(mesh_paths);
816 for_each_mesh_entry(tbl, p, node, i) {
818 if (rcu_dereference(mpath->next_hop) == sta)
819 mesh_path_del(mpath->dst, mpath->sdata);
824 void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
826 struct mesh_table *tbl;
827 struct mesh_path *mpath;
828 struct mpath_node *node;
829 struct hlist_node *p;
833 tbl = rcu_dereference(mesh_paths);
834 for_each_mesh_entry(tbl, p, node, i) {
836 if (mpath->sdata == sdata)
837 mesh_path_del(mpath->dst, mpath->sdata);
842 static void mesh_path_node_reclaim(struct rcu_head *rp)
844 struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
845 struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
847 del_timer_sync(&node->mpath->timer);
848 atomic_dec(&sdata->u.mesh.mpaths);
854 * mesh_path_del - delete a mesh path from the table
856 * @addr: dst address (ETH_ALEN length)
857 * @sdata: local subif
859 * Returns: 0 if successful
861 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
863 struct mesh_table *tbl;
864 struct mesh_path *mpath;
865 struct mpath_node *node;
866 struct hlist_head *bucket;
867 struct hlist_node *n;
871 read_lock_bh(&pathtbl_resize_lock);
872 tbl = resize_dereference_mesh_paths();
873 hash_idx = mesh_table_hash(addr, sdata, tbl);
874 bucket = &tbl->hash_buckets[hash_idx];
876 spin_lock_bh(&tbl->hashwlock[hash_idx]);
877 hlist_for_each_entry(node, n, bucket, list) {
879 if (mpath->sdata == sdata &&
880 memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
881 spin_lock_bh(&mpath->state_lock);
883 mesh_gate_del(tbl, mpath);
884 mpath->flags |= MESH_PATH_RESOLVING;
885 hlist_del_rcu(&node->list);
886 call_rcu(&node->rcu, mesh_path_node_reclaim);
887 atomic_dec(&tbl->entries);
888 spin_unlock_bh(&mpath->state_lock);
895 mesh_paths_generation++;
896 spin_unlock_bh(&tbl->hashwlock[hash_idx]);
897 read_unlock_bh(&pathtbl_resize_lock);
902 * mesh_path_tx_pending - sends pending frames in a mesh path queue
904 * @mpath: mesh path to activate
906 * Locking: the state_lock of the mpath structure must NOT be held when calling
909 void mesh_path_tx_pending(struct mesh_path *mpath)
911 if (mpath->flags & MESH_PATH_ACTIVE)
912 ieee80211_add_pending_skbs(mpath->sdata->local,
913 &mpath->frame_queue);
917 * mesh_path_send_to_gates - sends pending frames to all known mesh gates
919 * @mpath: mesh path whose queue will be emptied
921 * If there is only one gate, the frames are transferred from the failed mpath
922 * queue to that gate's queue. If there are more than one gates, the frames
923 * are copied from each gate to the next. After frames are copied, the
924 * mpath queues are emptied onto the transmission queue.
926 int mesh_path_send_to_gates(struct mesh_path *mpath)
928 struct ieee80211_sub_if_data *sdata = mpath->sdata;
929 struct hlist_node *n;
930 struct mesh_table *tbl;
931 struct mesh_path *from_mpath = mpath;
932 struct mpath_node *gate = NULL;
934 struct hlist_head *known_gates;
937 tbl = rcu_dereference(mesh_paths);
938 known_gates = tbl->known_gates;
942 return -EHOSTUNREACH;
944 hlist_for_each_entry_rcu(gate, n, known_gates, list) {
945 if (gate->mpath->sdata != sdata)
948 if (gate->mpath->flags & MESH_PATH_ACTIVE) {
949 mpath_dbg("Forwarding to %pM\n", gate->mpath->dst);
950 mesh_path_move_to_queue(gate->mpath, from_mpath, copy);
951 from_mpath = gate->mpath;
954 mpath_dbg("Not forwarding %p\n", gate->mpath);
955 mpath_dbg("flags %x\n", gate->mpath->flags);
959 hlist_for_each_entry_rcu(gate, n, known_gates, list)
960 if (gate->mpath->sdata == sdata) {
961 mpath_dbg("Sending to %pM\n", gate->mpath->dst);
962 mesh_path_tx_pending(gate->mpath);
965 return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
969 * mesh_path_discard_frame - discard a frame whose path could not be resolved
971 * @skb: frame to discard
972 * @sdata: network subif the frame was to be sent through
974 * If the frame was being forwarded from another MP, a PERR frame will be sent
975 * to the precursor. The precursor's address (i.e. the previous hop) was saved
976 * in addr1 of the frame-to-be-forwarded, and would only be overwritten once
977 * the destination is successfully resolved.
979 * Locking: the function must me called within a rcu_read_lock region
981 void mesh_path_discard_frame(struct sk_buff *skb,
982 struct ieee80211_sub_if_data *sdata)
984 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
985 struct mesh_path *mpath;
987 __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
989 if (memcmp(hdr->addr4, sdata->vif.addr, ETH_ALEN) != 0) {
995 mpath = mesh_path_lookup(da, sdata);
997 spin_lock_bh(&mpath->state_lock);
999 spin_unlock_bh(&mpath->state_lock);
1002 mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
1003 cpu_to_le32(sn), reason, ra, sdata);
1007 sdata->u.mesh.mshstats.dropped_frames_no_route++;
1011 * mesh_path_flush_pending - free the pending queue of a mesh path
1013 * @mpath: mesh path whose queue has to be freed
1015 * Locking: the function must me called within a rcu_read_lock region
1017 void mesh_path_flush_pending(struct mesh_path *mpath)
1019 struct sk_buff *skb;
1021 while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
1022 mesh_path_discard_frame(skb, mpath->sdata);
1026 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
1028 * @mpath: the mesh path to modify
1029 * @next_hop: the next hop to force
1031 * Locking: this function must be called holding mpath->state_lock
1033 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
1035 spin_lock_bh(&mpath->state_lock);
1036 mesh_path_assign_nexthop(mpath, next_hop);
1039 mpath->hop_count = 0;
1040 mpath->exp_time = 0;
1041 mpath->flags |= MESH_PATH_FIXED;
1042 mesh_path_activate(mpath);
1043 spin_unlock_bh(&mpath->state_lock);
1044 mesh_path_tx_pending(mpath);
1047 static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
1049 struct mesh_path *mpath;
1050 struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
1051 mpath = node->mpath;
1054 del_timer_sync(&mpath->timer);
1060 static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
1062 struct mesh_path *mpath;
1063 struct mpath_node *node, *new_node;
1066 new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
1067 if (new_node == NULL)
1070 node = hlist_entry(p, struct mpath_node, list);
1071 mpath = node->mpath;
1072 new_node->mpath = mpath;
1073 hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl);
1074 hlist_add_head(&new_node->list,
1075 &newtbl->hash_buckets[hash_idx]);
1079 int mesh_pathtbl_init(void)
1081 struct mesh_table *tbl_path, *tbl_mpp;
1083 tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
1086 tbl_path->free_node = &mesh_path_node_free;
1087 tbl_path->copy_node = &mesh_path_node_copy;
1088 tbl_path->mean_chain_len = MEAN_CHAIN_LEN;
1089 tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
1090 INIT_HLIST_HEAD(tbl_path->known_gates);
1093 tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
1095 mesh_table_free(tbl_path, true);
1098 tbl_mpp->free_node = &mesh_path_node_free;
1099 tbl_mpp->copy_node = &mesh_path_node_copy;
1100 tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN;
1101 tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
1102 INIT_HLIST_HEAD(tbl_mpp->known_gates);
1104 /* Need no locking since this is during init */
1105 RCU_INIT_POINTER(mesh_paths, tbl_path);
1106 RCU_INIT_POINTER(mpp_paths, tbl_mpp);
1111 void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
1113 struct mesh_table *tbl;
1114 struct mesh_path *mpath;
1115 struct mpath_node *node;
1116 struct hlist_node *p;
1120 tbl = rcu_dereference(mesh_paths);
1121 for_each_mesh_entry(tbl, p, node, i) {
1122 if (node->mpath->sdata != sdata)
1124 mpath = node->mpath;
1125 spin_lock_bh(&mpath->state_lock);
1126 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
1127 (!(mpath->flags & MESH_PATH_FIXED)) &&
1128 time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) {
1129 spin_unlock_bh(&mpath->state_lock);
1130 mesh_path_del(mpath->dst, mpath->sdata);
1132 spin_unlock_bh(&mpath->state_lock);
1137 void mesh_pathtbl_unregister(void)
1139 /* no need for locking during exit path */
1140 mesh_table_free(rcu_dereference_raw(mesh_paths), true);
1141 mesh_table_free(rcu_dereference_raw(mpp_paths), true);