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