aboutsummaryrefslogtreecommitdiffstats
path: root/net/mac80211/mesh.c
blob: b10f1e543a945733375704b5806c8cdbcfe26895 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
/*
 * Copyright (c) 2008 open80211s Ltd.
 * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
 * 	       Javier Cardona <javier@cozybit.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include "ieee80211_i.h"
#include "mesh.h"

#define ACCEPT_PLINKS 0x80

int mesh_allocated;
static struct kmem_cache *rm_cache;

void ieee80211s_init(void)
{
	mesh_pathtbl_init();
	mesh_allocated = 1;
	rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
				     0, 0, NULL);
}

void ieee80211s_stop(void)
{
	mesh_pathtbl_unregister();
	kmem_cache_destroy(rm_cache);
}

/**
 * mesh_matches_local - check if the config of a mesh point matches ours
 *
 * @ie: information elements of a management frame from the mesh peer
 * @dev: local mesh interface
 *
 * This function checks if the mesh configuration of a mesh point matches the
 * local mesh configuration, i.e. if both nodes belong to the same mesh network.
 */
bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_if_sta *sta = &sdata->u.sta;

	/*
	 * As support for each feature is added, check for matching
	 * - On mesh config capabilities
	 *   - Power Save Support En
	 *   - Sync support enabled
	 *   - Sync support active
	 *   - Sync support required from peer
	 *   - MDA enabled
	 * - Power management control on fc
	 */
	if (sta->mesh_id_len == ie->mesh_id_len &&
		memcmp(sta->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
		memcmp(sta->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 &&
		memcmp(sta->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 &&
		memcmp(sta->mesh_cc_id, ie->mesh_config + CC_OFFSET, 4) == 0)
		return true;

	return false;
}

/**
 * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
 *
 * @ie: information elements of a management frame from the mesh peer
 * @dev: local mesh interface
 */
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie,
			      struct net_device *dev)
{
	return (*(ie->mesh_config + CAPAB_OFFSET) & ACCEPT_PLINKS) != 0;
}

/**
 * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
 *
 * @sdata: mesh interface in which mesh beacons are going to be updated
 */
void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
{
	bool free_plinks;

	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
	 * the mesh interface might be able to establish plinks with peers that
	 * are already on the table but are not on PLINK_ESTAB state. However,
	 * in general the mesh interface is not accepting peer link requests
	 * from new peers, and that must be reflected in the beacon
	 */
	free_plinks = mesh_plink_availables(sdata);

	if (free_plinks != sdata->u.sta.accepting_plinks)
		ieee80211_sta_timer((unsigned long) sdata);
}

void mesh_ids_set_default(struct ieee80211_if_sta *sta)
{
	u8 def_id[4] = {0x00, 0x0F, 0xAC, 0xff};

	memcpy(sta->mesh_pp_id, def_id, 4);
	memcpy(sta->mesh_pm_id, def_id, 4);
	memcpy(sta->mesh_cc_id, def_id, 4);
}

int mesh_rmc_init(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	int i;

	sdata->u.sta.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
	if (!sdata->u.sta.rmc)
		return -ENOMEM;
	sdata->u.sta.rmc->idx_mask = RMC_BUCKETS - 1;
	for (i = 0; i < RMC_BUCKETS; i++)
		INIT_LIST_HEAD(&sdata->u.sta.rmc->bucket[i].list);
	return 0;
}

void mesh_rmc_free(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct mesh_rmc *rmc = sdata->u.sta.rmc;
	struct rmc_entry *p, *n;
	int i;

	if (!sdata->u.sta.rmc)
		return;

	for (i = 0; i < RMC_BUCKETS; i++)
		list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
			list_del(&p->list);
			kmem_cache_free(rm_cache, p);
		}

	kfree(rmc);
	sdata->u.sta.rmc = NULL;
}

/**
 * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 *
 * @sa:		source address
 * @mesh_hdr:	mesh_header
 *
 * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 *
 * Checks using the source address and the mesh sequence number if we have
 * received this frame lately. If the frame is not in the cache, it is added to
 * it.
 */
int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
		   struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct mesh_rmc *rmc = sdata->u.sta.rmc;
	u32 seqnum = 0;
	int entries = 0;
	u8 idx;
	struct rmc_entry *p, *n;

	/* Don't care about endianness since only match matters */
	memcpy(&seqnum, mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
	idx = mesh_hdr->seqnum[0] & rmc->idx_mask;
	list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
		++entries;
		if (time_after(jiffies, p->exp_time) ||
				(entries == RMC_QUEUE_MAX_LEN)) {
			list_del(&p->list);
			kmem_cache_free(rm_cache, p);
			--entries;
		} else if ((seqnum == p->seqnum)
				&& (memcmp(sa, p->sa, ETH_ALEN) == 0))
			return -1;
	}

	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
	if (!p) {
		printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
		return 0;
	}
	p->seqnum = seqnum;
	p->exp_time = jiffies + RMC_TIMEOUT;
	memcpy(p->sa, sa, ETH_ALEN);
	list_add(&p->list, &rmc->bucket[idx].list);
	return 0;
}

void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_supported_band *sband;
	u8 *pos;
	int len, i, rate;

	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
	len = sband->n_bitrates;
	if (len > 8)
		len = 8;
	pos = skb_put(skb, len + 2);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = len;
	for (i = 0; i < len; i++) {
		rate = sband->bitrates[i].bitrate;
		*pos++ = (u8) (rate / 5);
	}

	if (sband->n_bitrates > len) {
		pos = skb_put(skb, sband->n_bitrates - len + 2);
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = sband->n_bitrates - len;
		for (i = len; i < sband->n_bitrates; i++) {
			rate = sband->bitrates[i].bitrate;
			*pos++ = (u8) (rate / 5);
		}
	}

	pos = skb_put(skb, 2 + sdata->u.sta.mesh_id_len);
	*pos++ = WLAN_EID_MESH_ID;
	*pos++ = sdata->u.sta.mesh_id_len;
	if (sdata->u.sta.mesh_id_len)
		memcpy(pos, sdata->u.sta.mesh_id, sdata->u.sta.mesh_id_len);

	pos = skb_put(skb, 21);
	*pos++ = WLAN_EID_MESH_CONFIG;
	*pos++ = MESH_CFG_LEN;
	/* Version */
	*pos++ = 1;

	/* Active path selection protocol ID */
	memcpy(pos, sdata->u.sta.mesh_pp_id, 4);
	pos += 4;

	/* Active path selection metric ID   */
	memcpy(pos, sdata->u.sta.mesh_pm_id, 4);
	pos += 4;

	/* Congestion control mode identifier */
	memcpy(pos, sdata->u.sta.mesh_cc_id, 4);
	pos += 4;

	/* Channel precedence:
	 * Not running simple channel unification protocol
	 */
	memset(pos, 0x00, 4);
	pos += 4;

	/* Mesh capability */
	sdata->u.sta.accepting_plinks = mesh_plink_availables(sdata);
	*pos++ = sdata->u.sta.accepting_plinks ? ACCEPT_PLINKS : 0x00;
	*pos++ = 0x00;

	return;
}

u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl)
{
	/* Use last four bytes of hw addr and interface index as hash index */
	return jhash_2words(*(u32 *)(addr+2), dev->ifindex, tbl->hash_rnd)
		& tbl->hash_mask;
}

u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len)
{
	if (!mesh_id_len)
		return 1;
	else if (mesh_id_len == 1)
		return (u8) mesh_id[0];
	else
		return (u8) (mesh_id[0] + 2 * mesh_id[1]);
}

struct mesh_table *mesh_table_alloc(int size_order)
{
	int i;
	struct mesh_table *newtbl;

	newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
	if (!newtbl)
		return NULL;

	newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
			(1 << size_order), GFP_KERNEL);

	if (!newtbl->hash_buckets) {
		kfree(newtbl);
		return NULL;
	}

	newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
			(1 << size_order), GFP_KERNEL);
	if (!newtbl->hashwlock) {
		kfree(newtbl->hash_buckets);
		kfree(newtbl);
		return NULL;
	}

	newtbl->size_order = size_order;
	newtbl->hash_mask = (1 << size_order) - 1;
	atomic_set(&newtbl->entries,  0);
	get_random_bytes(&newtbl->hash_rnd,
			sizeof(newtbl->hash_rnd));
	for (i = 0; i <= newtbl->hash_mask; i++)
		spin_lock_init(&newtbl->hashwlock[i]);

	return newtbl;
}

void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
{
	struct hlist_head *mesh_hash;
	struct hlist_node *p, *q;
	int i;

	mesh_hash = tbl->hash_buckets;
	for (i = 0; i <= tbl->hash_mask; i++) {
		spin_lock(&tbl->hashwlock[i]);
		hlist_for_each_safe(p, q, &mesh_hash[i]) {
			tbl->free_node(p, free_leafs);
			atomic_dec(&tbl->entries);
		}
		spin_unlock(&tbl->hashwlock[i]);
	}
	kfree(tbl->hash_buckets);
	kfree(tbl->hashwlock);
	kfree(tbl);
}

static void ieee80211_mesh_path_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct ieee80211_local *local = wdev_priv(&sdata->wdev);

	queue_work(local->hw.workqueue, &ifsta->work);
}

struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
{
	struct mesh_table *newtbl;
	struct hlist_head *oldhash;
	struct hlist_node *p;
	int err = 0;
	int i;

	if (atomic_read(&tbl->entries)
			< tbl->mean_chain_len * (tbl->hash_mask + 1)) {
		err = -EPERM;
		goto endgrow;
	}

	newtbl = mesh_table_alloc(tbl->size_order + 1);
	if (!newtbl) {
		err = -ENOMEM;
		goto endgrow;
	}

	newtbl->free_node = tbl->free_node;
	newtbl->mean_chain_len = tbl->mean_chain_len;
	newtbl->copy_node = tbl->copy_node;
	atomic_set(&newtbl->entries, atomic_read(&tbl->entries));

	oldhash = tbl->hash_buckets;
	for (i = 0; i <= tbl->hash_mask; i++)
		hlist_for_each(p, &oldhash[i])
			tbl->copy_node(p, newtbl);

endgrow:
	if (err)
		return NULL;
	else
		return newtbl;
}

/**
 * ieee80211_new_mesh_header - create a new mesh header
 * @meshhdr:    uninitialized mesh header
 * @sdata:	mesh interface to be used
 *
 * Return the header length.
 */
int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
		struct ieee80211_sub_if_data *sdata)
{
	meshhdr->flags = 0;
	meshhdr->ttl = sdata->u.sta.mshcfg.dot11MeshTTL;

	meshhdr->seqnum[0] = sdata->u.sta.mesh_seqnum[0]++;
	meshhdr->seqnum[1] = sdata->u.sta.mesh_seqnum[1];
	meshhdr->seqnum[2] = sdata->u.sta.mesh_seqnum[2];

	if (sdata->u.sta.mesh_seqnum[0] == 0) {
		sdata->u.sta.mesh_seqnum[1]++;
		if (sdata->u.sta.mesh_seqnum[1] == 0)
			sdata->u.sta.mesh_seqnum[2]++;
	}

	return 5;
}

void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;

	ifsta->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
	ifsta->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
	ifsta->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
	ifsta->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
	ifsta->mshcfg.dot11MeshTTL = MESH_TTL;
	ifsta->mshcfg.auto_open_plinks = true;
	ifsta->mshcfg.dot11MeshMaxPeerLinks =
		MESH_MAX_ESTAB_PLINKS;
	ifsta->mshcfg.dot11MeshHWMPactivePathTimeout =
		MESH_PATH_TIMEOUT;
	ifsta->mshcfg.dot11MeshHWMPpreqMinInterval =
		MESH_PREQ_MIN_INT;
	ifsta->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
		MESH_DIAM_TRAVERSAL_TIME;
	ifsta->mshcfg.dot11MeshHWMPmaxPREQretries =
		MESH_MAX_PREQ_RETRIES;
	ifsta->mshcfg.path_refresh_time =
		MESH_PATH_REFRESH_TIME;
	ifsta->mshcfg.min_discovery_timeout =
		MESH_MIN_DISCOVERY_TIMEOUT;
	ifsta->accepting_plinks = true;
	ifsta->preq_id = 0;
	ifsta->dsn = 0;
	atomic_set(&ifsta->mpaths, 0);
	mesh_rmc_init(sdata->dev);
	ifsta->last_preq = jiffies;
	/* Allocate all mesh structures when creating the first mesh interface. */
	if (!mesh_allocated)
		ieee80211s_init();
	mesh_ids_set_default(ifsta);
	setup_timer(&ifsta->mesh_path_timer,
		    ieee80211_mesh_path_timer,
		    (unsigned long) sdata);
	INIT_LIST_HEAD(&ifsta->preq_queue.list);
	spin_lock_init(&ifsta->mesh_preq_queue_lock);
}