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authorLuis Carlos Cobo <luisca@cozybit.com>2008-02-23 09:17:09 -0500
committerJohn W. Linville <linville@tuxdriver.com>2008-03-06 15:30:41 -0500
commit2e3c8736820bf72a8ad10721c7e31d36d4fa7790 (patch)
tree21c6afeff5a649c40d8fd1f166b0c56aaf2e21c0 /net/mac80211/mesh.c
parentccf80ddfe4923ae75cd3536723880277d285e779 (diff)
mac80211: support functions for mesh
The two important features coded in mesh.c are: Recently Multicast Cache: in on-demand HWMP, multicast traffic is retransmitted by every receiving node. Even though a mesh TTL counter avoids infinite loops, it is also necessary to avoid traffic explosion by keeping a cache of multicast mesh frame that have been received recently. With this feature, maximum number of retransmissions of a multicast frame for the case of N nodes within the range of each other would be N. Without it, the maximum number of retransmissions would be in the order of N^(MESH_TTL - 1). Code to support mesh tables. Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/mesh.c')
-rw-r--r--net/mac80211/mesh.c383
1 files changed, 383 insertions, 0 deletions
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
new file mode 100644
index 000000000000..8ff533005d92
--- /dev/null
+++ b/net/mac80211/mesh.c
@@ -0,0 +1,383 @@
1/*
2 * Copyright (c) 2008 open80211s Ltd.
3 * Authors: Luis Carlos Cobo <luisca@cozybit.com>
4 * Javier Cardona <javier@cozybit.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include "ieee80211_i.h"
12#include "mesh.h"
13
14#define PP_OFFSET 1 /* Path Selection Protocol */
15#define PM_OFFSET 5 /* Path Selection Metric */
16#define CC_OFFSET 9 /* Congestion Control Mode */
17#define CAPAB_OFFSET 17
18#define ACCEPT_PLINKS 0x80
19
20int mesh_allocated;
21static struct kmem_cache *rm_cache;
22
23void ieee80211s_init(void)
24{
25 mesh_pathtbl_init();
26 mesh_allocated = 1;
27 rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
28 0, 0, NULL);
29}
30
31void ieee80211s_stop(void)
32{
33 mesh_pathtbl_unregister();
34 kmem_cache_destroy(rm_cache);
35}
36
37/**
38 * mesh_matches_local - check if the config of a mesh point matches ours
39 *
40 * @ie: information elements of a management frame from the mesh peer
41 * @dev: local mesh interface
42 *
43 * This function checks if the mesh configuration of a mesh point matches the
44 * local mesh configuration, i.e. if both nodes belong to the same mesh network.
45 */
46bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev)
47{
48 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
49 struct ieee80211_if_sta *sta = &sdata->u.sta;
50
51 if (sta->mesh_id_len == ie->mesh_id_len &&
52 memcmp(sta->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
53 memcmp(sta->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 &&
54 memcmp(sta->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 &&
55 memcmp(sta->mesh_cc_id, ie->mesh_config + CC_OFFSET, 4) == 0)
56 /*
57 * As support for each feature is added, check for matching
58 * - On mesh config capabilities
59 * - Power Save Support En
60 * - Sync support enabled
61 * - Sync support active
62 * - Sync support required from peer
63 * - MDA enabled
64 * - Power management control on fc
65 */
66 return true;
67
68 return false;
69}
70
71/**
72 * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
73 *
74 * @ie: information elements of a management frame from the mesh peer
75 * @dev: local mesh interface
76 */
77bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie,
78 struct net_device *dev)
79{
80 return (*(ie->mesh_config + CAPAB_OFFSET) & ACCEPT_PLINKS) != 0;
81}
82
83/**
84 * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
85 *
86 * @dev: mesh interface in which mesh beacons are going to be updated
87 */
88void mesh_accept_plinks_update(struct net_device *dev)
89{
90 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
91 bool free_plinks;
92
93 /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
94 * the mesh interface might be able to establish plinks with peers that
95 * are already on the table but are not on ESTAB state. However, in
96 * general the mesh interface is not accepting peer link requests from
97 * new peers, and that must be reflected in the beacon
98 */
99 free_plinks = mesh_plink_availables(sdata);
100
101 if (free_plinks != sdata->u.sta.accepting_plinks)
102 ieee80211_sta_timer((unsigned long) sdata);
103}
104
105void mesh_ids_set_default(struct ieee80211_if_sta *sta)
106{
107 u8 def_id[4] = {0x00, 0x0F, 0xAC, 0xff};
108
109 memcpy(sta->mesh_pp_id, def_id, 4);
110 memcpy(sta->mesh_pm_id, def_id, 4);
111 memcpy(sta->mesh_cc_id, def_id, 4);
112}
113
114int mesh_rmc_init(struct net_device *dev)
115{
116 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
117 int i;
118
119 sdata->u.sta.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
120 if (!sdata->u.sta.rmc)
121 return -ENOMEM;
122 sdata->u.sta.rmc->idx_mask = RMC_BUCKETS - 1;
123 for (i = 0; i < RMC_BUCKETS; i++)
124 INIT_LIST_HEAD(&sdata->u.sta.rmc->bucket[i].list);
125 return 0;
126}
127
128void mesh_rmc_free(struct net_device *dev)
129{
130 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
131 struct mesh_rmc *rmc = sdata->u.sta.rmc;
132 struct rmc_entry *p, *n;
133 int i;
134
135 if (!sdata->u.sta.rmc)
136 return;
137
138 for (i = 0; i < RMC_BUCKETS; i++)
139 list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
140 list_del(&p->list);
141 kmem_cache_free(rm_cache, p);
142 }
143
144 kfree(rmc);
145 sdata->u.sta.rmc = NULL;
146}
147
148/**
149 * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
150 *
151 * @sa: source address
152 * @mesh_hdr: mesh_header
153 *
154 * Returns: 0 if the frame is not in the cache, nonzero otherwise.
155 *
156 * Checks using the source address and the mesh sequence number if we have
157 * received this frame lately. If the frame is not in the cache, it is added to
158 * it.
159 */
160int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
161 struct net_device *dev)
162{
163 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
164 struct mesh_rmc *rmc = sdata->u.sta.rmc;
165 u32 seqnum = 0;
166 int entries = 0;
167 u8 idx;
168 struct rmc_entry *p, *n;
169
170 /* Don't care about endianness since only match matters */
171 memcpy(&seqnum, mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
172 idx = mesh_hdr->seqnum[0] & rmc->idx_mask;
173 list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
174 ++entries;
175 if (time_after(jiffies, p->exp_time) ||
176 (entries == RMC_QUEUE_MAX_LEN)) {
177 list_del(&p->list);
178 kmem_cache_free(rm_cache, p);
179 --entries;
180 } else if ((seqnum == p->seqnum)
181 && (memcmp(sa, p->sa, ETH_ALEN) == 0))
182 return -1;
183 }
184
185 p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
186 if (!p) {
187 printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
188 return 0;
189 }
190 p->seqnum = seqnum;
191 p->exp_time = jiffies + RMC_TIMEOUT;
192 memcpy(p->sa, sa, ETH_ALEN);
193 list_add(&p->list, &rmc->bucket[idx].list);
194 return 0;
195}
196
197void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev)
198{
199 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
200 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
201 struct ieee80211_supported_band *sband;
202 u8 *pos;
203 int len, i, rate;
204
205 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
206 len = sband->n_bitrates;
207 if (len > 8)
208 len = 8;
209 pos = skb_put(skb, len + 2);
210 *pos++ = WLAN_EID_SUPP_RATES;
211 *pos++ = len;
212 for (i = 0; i < len; i++) {
213 rate = sband->bitrates[i].bitrate;
214 *pos++ = (u8) (rate / 5);
215 }
216
217 if (sband->n_bitrates > len) {
218 pos = skb_put(skb, sband->n_bitrates - len + 2);
219 *pos++ = WLAN_EID_EXT_SUPP_RATES;
220 *pos++ = sband->n_bitrates - len;
221 for (i = len; i < sband->n_bitrates; i++) {
222 rate = sband->bitrates[i].bitrate;
223 *pos++ = (u8) (rate / 5);
224 }
225 }
226
227 pos = skb_put(skb, 2 + sdata->u.sta.mesh_id_len);
228 *pos++ = WLAN_EID_MESH_ID;
229 *pos++ = sdata->u.sta.mesh_id_len;
230 if (sdata->u.sta.mesh_id_len)
231 memcpy(pos, sdata->u.sta.mesh_id, sdata->u.sta.mesh_id_len);
232
233 pos = skb_put(skb, 21);
234 *pos++ = WLAN_EID_MESH_CONFIG;
235 *pos++ = MESH_CFG_LEN;
236 /* Version */
237 *pos++ = 1;
238
239 /* Active path selection protocol ID */
240 memcpy(pos, sdata->u.sta.mesh_pp_id, 4);
241 pos += 4;
242
243 /* Active path selection metric ID */
244 memcpy(pos, sdata->u.sta.mesh_pm_id, 4);
245 pos += 4;
246
247 /* Congestion control mode identifier */
248 memcpy(pos, sdata->u.sta.mesh_cc_id, 4);
249 pos += 4;
250
251 /* Channel precedence:
252 * Not running simple channel unification protocol
253 */
254 memset(pos, 0x00, 4);
255 pos += 4;
256
257 /* Mesh capability */
258 sdata->u.sta.accepting_plinks = mesh_plink_availables(sdata);
259 *pos++ = sdata->u.sta.accepting_plinks ? ACCEPT_PLINKS : 0x00;
260 *pos++ = 0x00;
261
262 return;
263}
264
265u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl)
266{
267 /* Use last four bytes of hw addr and interface index as hash index */
268 return jhash_2words(*(u32 *)(addr+2), dev->ifindex, tbl->hash_rnd)
269 & tbl->hash_mask;
270}
271
272u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len)
273{
274 if (!mesh_id_len)
275 return 1;
276 else if (mesh_id_len == 1)
277 return (u8) mesh_id[0];
278 else
279 return (u8) (mesh_id[0] + 2 * mesh_id[1]);
280}
281
282struct mesh_table *mesh_table_alloc(int size_order)
283{
284 int i;
285 struct mesh_table *newtbl;
286
287 newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
288 if (!newtbl)
289 return NULL;
290
291 newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
292 (1 << size_order), GFP_KERNEL);
293
294 if (!newtbl->hash_buckets) {
295 kfree(newtbl);
296 return NULL;
297 }
298
299 newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
300 (1 << size_order), GFP_KERNEL);
301 if (!newtbl->hashwlock) {
302 kfree(newtbl->hash_buckets);
303 kfree(newtbl);
304 return NULL;
305 }
306
307 newtbl->size_order = size_order;
308 newtbl->hash_mask = (1 << size_order) - 1;
309 atomic_set(&newtbl->entries, 0);
310 get_random_bytes(&newtbl->hash_rnd,
311 sizeof(newtbl->hash_rnd));
312 for (i = 0; i <= newtbl->hash_mask; i++)
313 spin_lock_init(&newtbl->hashwlock[i]);
314
315 return newtbl;
316}
317
318void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
319{
320 struct hlist_head *mesh_hash;
321 struct hlist_node *p, *q;
322 int i;
323
324 mesh_hash = tbl->hash_buckets;
325 for (i = 0; i <= tbl->hash_mask; i++) {
326 spin_lock(&tbl->hashwlock[i]);
327 hlist_for_each_safe(p, q, &mesh_hash[i]) {
328 tbl->free_node(p, free_leafs);
329 atomic_dec(&tbl->entries);
330 }
331 spin_unlock(&tbl->hashwlock[i]);
332 }
333 kfree(tbl->hash_buckets);
334 kfree(tbl->hashwlock);
335 kfree(tbl);
336}
337
338static void ieee80211_mesh_path_timer(unsigned long data)
339{
340 struct ieee80211_sub_if_data *sdata =
341 (struct ieee80211_sub_if_data *) data;
342 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
343 struct ieee80211_local *local = wdev_priv(&sdata->wdev);
344
345 queue_work(local->hw.workqueue, &ifsta->work);
346}
347
348struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
349{
350 struct mesh_table *newtbl;
351 struct hlist_head *oldhash;
352 struct hlist_node *p;
353 int err = 0;
354 int i;
355
356 if (atomic_read(&tbl->entries)
357 < tbl->mean_chain_len * (tbl->hash_mask + 1)) {
358 err = -EPERM;
359 goto endgrow;
360 }
361
362 newtbl = mesh_table_alloc(tbl->size_order + 1);
363 if (!newtbl) {
364 err = -ENOMEM;
365 goto endgrow;
366 }
367
368 newtbl->free_node = tbl->free_node;
369 newtbl->mean_chain_len = tbl->mean_chain_len;
370 newtbl->copy_node = tbl->copy_node;
371 atomic_set(&newtbl->entries, atomic_read(&tbl->entries));
372
373 oldhash = tbl->hash_buckets;
374 for (i = 0; i <= tbl->hash_mask; i++)
375 hlist_for_each(p, &oldhash[i])
376 tbl->copy_node(p, newtbl);
377
378endgrow:
379 if (err)
380 return NULL;
381 else
382 return newtbl;
383}