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ksm: clean up obsolete references
[linux-2.6/next.git] / net / mac80211 / mesh_hwmp.c
blobe12a786e26b8046769f6b30ba2946c3948f680ff
1 /*
2 * Copyright (c) 2008 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
4 *
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.
8 */
9
10 #include "mesh.h"
11
12 #define TEST_FRAME_LEN 8192
13 #define MAX_METRIC 0xffffffff
14 #define ARITH_SHIFT 8
15
16 /* Number of frames buffered per destination for unresolved destinations */
17 #define MESH_FRAME_QUEUE_LEN 10
18 #define MAX_PREQ_QUEUE_LEN 64
19
20 /* Destination only */
21 #define MP_F_DO 0x1
22 /* Reply and forward */
23 #define MP_F_RF 0x2
24
25 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
26 {
27 if (ae)
28 offset += 6;
29 return get_unaligned_le32(preq_elem + offset);
30 }
31
32 /* HWMP IE processing macros */
33 #define AE_F (1<<6)
34 #define AE_F_SET(x) (*x & AE_F)
35 #define PREQ_IE_FLAGS(x) (*(x))
36 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
37 #define PREQ_IE_TTL(x) (*(x + 2))
38 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
39 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
40 #define PREQ_IE_ORIG_DSN(x) u32_field_get(x, 13, 0);
41 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x));
42 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x));
43 #define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
44 #define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
45 #define PREQ_IE_DST_DSN(x) u32_field_get(x, 33, AE_F_SET(x));
46
47
48 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
49 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
50 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
51 #define PREP_IE_ORIG_ADDR(x) (x + 3)
52 #define PREP_IE_ORIG_DSN(x) u32_field_get(x, 9, 0);
53 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x));
54 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x));
55 #define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
56 #define PREP_IE_DST_DSN(x) u32_field_get(x, 27, AE_F_SET(x));
57
58 #define PERR_IE_DST_ADDR(x) (x + 2)
59 #define PERR_IE_DST_DSN(x) u32_field_get(x, 8, 0);
60
61 #define MSEC_TO_TU(x) (x*1000/1024)
62 #define DSN_GT(x, y) ((long) (y) - (long) (x) < 0)
63 #define DSN_LT(x, y) ((long) (x) - (long) (y) < 0)
64
65 #define net_traversal_jiffies(s) \
66 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
67 #define default_lifetime(s) \
68 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
69 #define min_preq_int_jiff(s) \
70 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
71 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
72 #define disc_timeout_jiff(s) \
73 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
74
75 enum mpath_frame_type {
76 MPATH_PREQ = 0,
77 MPATH_PREP,
78 MPATH_PERR
79 };
80
81 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
82 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst,
83 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime,
84 __le32 metric, __le32 preq_id, struct ieee80211_sub_if_data *sdata)
85 {
86 struct ieee80211_local *local = sdata->local;
87 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
88 struct ieee80211_mgmt *mgmt;
89 u8 *pos;
90 int ie_len;
91
92 if (!skb)
93 return -1;
94 skb_reserve(skb, local->hw.extra_tx_headroom);
95 /* 25 is the size of the common mgmt part (24) plus the size of the
96 * common action part (1)
97 */
98 mgmt = (struct ieee80211_mgmt *)
99 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
100 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
101 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
102 IEEE80211_STYPE_ACTION);
103
104 memcpy(mgmt->da, da, ETH_ALEN);
105 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
106 /* BSSID is left zeroed, wildcard value */
107 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
108 mgmt->u.action.u.mesh_action.action_code = action;
109
110 switch (action) {
111 case MPATH_PREQ:
112 ie_len = 37;
113 pos = skb_put(skb, 2 + ie_len);
114 *pos++ = WLAN_EID_PREQ;
115 break;
116 case MPATH_PREP:
117 ie_len = 31;
118 pos = skb_put(skb, 2 + ie_len);
119 *pos++ = WLAN_EID_PREP;
120 break;
121 default:
122 kfree_skb(skb);
123 return -ENOTSUPP;
124 break;
125 }
126 *pos++ = ie_len;
127 *pos++ = flags;
128 *pos++ = hop_count;
129 *pos++ = ttl;
130 if (action == MPATH_PREQ) {
131 memcpy(pos, &preq_id, 4);
132 pos += 4;
133 }
134 memcpy(pos, orig_addr, ETH_ALEN);
135 pos += ETH_ALEN;
136 memcpy(pos, &orig_dsn, 4);
137 pos += 4;
138 memcpy(pos, &lifetime, 4);
139 pos += 4;
140 memcpy(pos, &metric, 4);
141 pos += 4;
142 if (action == MPATH_PREQ) {
143 /* destination count */
144 *pos++ = 1;
145 *pos++ = dst_flags;
146 }
147 memcpy(pos, dst, ETH_ALEN);
148 pos += ETH_ALEN;
149 memcpy(pos, &dst_dsn, 4);
150
151 ieee80211_tx_skb(sdata, skb, 1);
152 return 0;
153 }
154
155 /**
156 * mesh_send_path error - Sends a PERR mesh management frame
157 *
158 * @dst: broken destination
159 * @dst_dsn: dsn of the broken destination
160 * @ra: node this frame is addressed to
161 */
162 int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
163 struct ieee80211_sub_if_data *sdata)
164 {
165 struct ieee80211_local *local = sdata->local;
166 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
167 struct ieee80211_mgmt *mgmt;
168 u8 *pos;
169 int ie_len;
170
171 if (!skb)
172 return -1;
173 skb_reserve(skb, local->hw.extra_tx_headroom);
174 /* 25 is the size of the common mgmt part (24) plus the size of the
175 * common action part (1)
176 */
177 mgmt = (struct ieee80211_mgmt *)
178 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
179 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
180 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
181 IEEE80211_STYPE_ACTION);
182
183 memcpy(mgmt->da, ra, ETH_ALEN);
184 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
185 /* BSSID is left zeroed, wildcard value */
186 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
187 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR;
188 ie_len = 12;
189 pos = skb_put(skb, 2 + ie_len);
190 *pos++ = WLAN_EID_PERR;
191 *pos++ = ie_len;
192 /* mode flags, reserved */
193 *pos++ = 0;
194 /* number of destinations */
195 *pos++ = 1;
196 memcpy(pos, dst, ETH_ALEN);
197 pos += ETH_ALEN;
198 memcpy(pos, &dst_dsn, 4);
199
200 ieee80211_tx_skb(sdata, skb, 1);
201 return 0;
202 }
203
204 void ieee80211s_update_metric(struct ieee80211_local *local,
205 struct sta_info *stainfo, struct sk_buff *skb)
206 {
207 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
208 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
209 int failed;
210
211 if (!ieee80211_is_data(hdr->frame_control))
212 return;
213
214 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
215
216 /* moving average, scaled to 100 */
217 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
218 if (stainfo->fail_avg > 95)
219 mesh_plink_broken(stainfo);
220 }
221
222 static u32 airtime_link_metric_get(struct ieee80211_local *local,
223 struct sta_info *sta)
224 {
225 struct ieee80211_supported_band *sband;
226 /* This should be adjusted for each device */
227 int device_constant = 1 << ARITH_SHIFT;
228 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
229 int s_unit = 1 << ARITH_SHIFT;
230 int rate, err;
231 u32 tx_time, estimated_retx;
232 u64 result;
233
234 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
235
236 if (sta->fail_avg >= 100)
237 return MAX_METRIC;
238
239 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
240 return MAX_METRIC;
241
242 err = (sta->fail_avg << ARITH_SHIFT) / 100;
243
244 /* bitrate is in units of 100 Kbps, while we need rate in units of
245 * 1Mbps. This will be corrected on tx_time computation.
246 */
247 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
248 tx_time = (device_constant + 10 * test_frame_len / rate);
249 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
250 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
251 return (u32)result;
252 }
253
254 /**
255 * hwmp_route_info_get - Update routing info to originator and transmitter
256 *
257 * @sdata: local mesh subif
258 * @mgmt: mesh management frame
259 * @hwmp_ie: hwmp information element (PREP or PREQ)
260 *
261 * This function updates the path routing information to the originator and the
262 * transmitter of a HWMP PREQ or PREP fram.
263 *
264 * Returns: metric to frame originator or 0 if the frame should not be further
265 * processed
266 *
267 * Notes: this function is the only place (besides user-provided info) where
268 * path routing information is updated.
269 */
270 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
271 struct ieee80211_mgmt *mgmt,
272 u8 *hwmp_ie)
273 {
274 struct ieee80211_local *local = sdata->local;
275 struct mesh_path *mpath;
276 struct sta_info *sta;
277 bool fresh_info;
278 u8 *orig_addr, *ta;
279 u32 orig_dsn, orig_metric;
280 unsigned long orig_lifetime, exp_time;
281 u32 last_hop_metric, new_metric;
282 bool process = true;
283 u8 action = mgmt->u.action.u.mesh_action.action_code;
284
285 rcu_read_lock();
286 sta = sta_info_get(local, mgmt->sa);
287 if (!sta) {
288 rcu_read_unlock();
289 return 0;
290 }
291
292 last_hop_metric = airtime_link_metric_get(local, sta);
293 /* Update and check originator routing info */
294 fresh_info = true;
295
296 switch (action) {
297 case MPATH_PREQ:
298 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
299 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
300 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
301 orig_metric = PREQ_IE_METRIC(hwmp_ie);
302 break;
303 case MPATH_PREP:
304 /* Originator here refers to the MP that was the destination in
305 * the Path Request. The draft refers to that MP as the
306 * destination address, even though usually it is the origin of
307 * the PREP frame. We divert from the nomenclature in the draft
308 * so that we can easily use a single function to gather path
309 * information from both PREQ and PREP frames.
310 */
311 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
312 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
313 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
314 orig_metric = PREP_IE_METRIC(hwmp_ie);
315 break;
316 default:
317 rcu_read_unlock();
318 return 0;
319 }
320 new_metric = orig_metric + last_hop_metric;
321 if (new_metric < orig_metric)
322 new_metric = MAX_METRIC;
323 exp_time = TU_TO_EXP_TIME(orig_lifetime);
324
325 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
326 /* This MP is the originator, we are not interested in this
327 * frame, except for updating transmitter's path info.
328 */
329 process = false;
330 fresh_info = false;
331 } else {
332 mpath = mesh_path_lookup(orig_addr, sdata);
333 if (mpath) {
334 spin_lock_bh(&mpath->state_lock);
335 if (mpath->flags & MESH_PATH_FIXED)
336 fresh_info = false;
337 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
338 (mpath->flags & MESH_PATH_DSN_VALID)) {
339 if (DSN_GT(mpath->dsn, orig_dsn) ||
340 (mpath->dsn == orig_dsn &&
341 action == MPATH_PREQ &&
342 new_metric > mpath->metric)) {
343 process = false;
344 fresh_info = false;
345 }
346 }
347 } else {
348 mesh_path_add(orig_addr, sdata);
349 mpath = mesh_path_lookup(orig_addr, sdata);
350 if (!mpath) {
351 rcu_read_unlock();
352 return 0;
353 }
354 spin_lock_bh(&mpath->state_lock);
355 }
356
357 if (fresh_info) {
358 mesh_path_assign_nexthop(mpath, sta);
359 mpath->flags |= MESH_PATH_DSN_VALID;
360 mpath->metric = new_metric;
361 mpath->dsn = orig_dsn;
362 mpath->exp_time = time_after(mpath->exp_time, exp_time)
363 ? mpath->exp_time : exp_time;
364 mesh_path_activate(mpath);
365 spin_unlock_bh(&mpath->state_lock);
366 mesh_path_tx_pending(mpath);
367 /* draft says preq_id should be saved to, but there does
368 * not seem to be any use for it, skipping by now
369 */
370 } else
371 spin_unlock_bh(&mpath->state_lock);
372 }
373
374 /* Update and check transmitter routing info */
375 ta = mgmt->sa;
376 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
377 fresh_info = false;
378 else {
379 fresh_info = true;
380
381 mpath = mesh_path_lookup(ta, sdata);
382 if (mpath) {
383 spin_lock_bh(&mpath->state_lock);
384 if ((mpath->flags & MESH_PATH_FIXED) ||
385 ((mpath->flags & MESH_PATH_ACTIVE) &&
386 (last_hop_metric > mpath->metric)))
387 fresh_info = false;
388 } else {
389 mesh_path_add(ta, sdata);
390 mpath = mesh_path_lookup(ta, sdata);
391 if (!mpath) {
392 rcu_read_unlock();
393 return 0;
394 }
395 spin_lock_bh(&mpath->state_lock);
396 }
397
398 if (fresh_info) {
399 mesh_path_assign_nexthop(mpath, sta);
400 mpath->flags &= ~MESH_PATH_DSN_VALID;
401 mpath->metric = last_hop_metric;
402 mpath->exp_time = time_after(mpath->exp_time, exp_time)
403 ? mpath->exp_time : exp_time;
404 mesh_path_activate(mpath);
405 spin_unlock_bh(&mpath->state_lock);
406 mesh_path_tx_pending(mpath);
407 } else
408 spin_unlock_bh(&mpath->state_lock);
409 }
410
411 rcu_read_unlock();
412
413 return process ? new_metric : 0;
414 }
415
416 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
417 struct ieee80211_mgmt *mgmt,
418 u8 *preq_elem, u32 metric)
419 {
420 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
421 struct mesh_path *mpath;
422 u8 *dst_addr, *orig_addr;
423 u8 dst_flags, ttl;
424 u32 orig_dsn, dst_dsn, lifetime;
425 bool reply = false;
426 bool forward = true;
427
428 /* Update destination DSN, if present */
429 dst_addr = PREQ_IE_DST_ADDR(preq_elem);
430 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
431 dst_dsn = PREQ_IE_DST_DSN(preq_elem);
432 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem);
433 dst_flags = PREQ_IE_DST_F(preq_elem);
434
435 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
436 forward = false;
437 reply = true;
438 metric = 0;
439 if (time_after(jiffies, ifmsh->last_dsn_update +
440 net_traversal_jiffies(sdata)) ||
441 time_before(jiffies, ifmsh->last_dsn_update)) {
442 dst_dsn = ++ifmsh->dsn;
443 ifmsh->last_dsn_update = jiffies;
444 }
445 } else {
446 rcu_read_lock();
447 mpath = mesh_path_lookup(dst_addr, sdata);
448 if (mpath) {
449 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) ||
450 DSN_LT(mpath->dsn, dst_dsn)) {
451 mpath->dsn = dst_dsn;
452 mpath->flags |= MESH_PATH_DSN_VALID;
453 } else if ((!(dst_flags & MP_F_DO)) &&
454 (mpath->flags & MESH_PATH_ACTIVE)) {
455 reply = true;
456 metric = mpath->metric;
457 dst_dsn = mpath->dsn;
458 if (dst_flags & MP_F_RF)
459 dst_flags |= MP_F_DO;
460 else
461 forward = false;
462 }
463 }
464 rcu_read_unlock();
465 }
466
467 if (reply) {
468 lifetime = PREQ_IE_LIFETIME(preq_elem);
469 ttl = ifmsh->mshcfg.dot11MeshTTL;
470 if (ttl != 0)
471 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr,
472 cpu_to_le32(dst_dsn), 0, orig_addr,
473 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl,
474 cpu_to_le32(lifetime), cpu_to_le32(metric),
475 0, sdata);
476 else
477 ifmsh->mshstats.dropped_frames_ttl++;
478 }
479
480 if (forward) {
481 u32 preq_id;
482 u8 hopcount, flags;
483
484 ttl = PREQ_IE_TTL(preq_elem);
485 lifetime = PREQ_IE_LIFETIME(preq_elem);
486 if (ttl <= 1) {
487 ifmsh->mshstats.dropped_frames_ttl++;
488 return;
489 }
490 --ttl;
491 flags = PREQ_IE_FLAGS(preq_elem);
492 preq_id = PREQ_IE_PREQ_ID(preq_elem);
493 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
494 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
495 cpu_to_le32(orig_dsn), dst_flags, dst_addr,
496 cpu_to_le32(dst_dsn), sdata->dev->broadcast,
497 hopcount, ttl, cpu_to_le32(lifetime),
498 cpu_to_le32(metric), cpu_to_le32(preq_id),
499 sdata);
500 ifmsh->mshstats.fwded_mcast++;
501 ifmsh->mshstats.fwded_frames++;
502 }
503 }
504
505
506 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
507 struct ieee80211_mgmt *mgmt,
508 u8 *prep_elem, u32 metric)
509 {
510 struct mesh_path *mpath;
511 u8 *dst_addr, *orig_addr;
512 u8 ttl, hopcount, flags;
513 u8 next_hop[ETH_ALEN];
514 u32 dst_dsn, orig_dsn, lifetime;
515
516 /* Note that we divert from the draft nomenclature and denominate
517 * destination to what the draft refers to as origininator. So in this
518 * function destnation refers to the final destination of the PREP,
519 * which corresponds with the originator of the PREQ which this PREP
520 * replies
521 */
522 dst_addr = PREP_IE_DST_ADDR(prep_elem);
523 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0)
524 /* destination, no forwarding required */
525 return;
526
527 ttl = PREP_IE_TTL(prep_elem);
528 if (ttl <= 1) {
529 sdata->u.mesh.mshstats.dropped_frames_ttl++;
530 return;
531 }
532
533 rcu_read_lock();
534 mpath = mesh_path_lookup(dst_addr, sdata);
535 if (mpath)
536 spin_lock_bh(&mpath->state_lock);
537 else
538 goto fail;
539 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
540 spin_unlock_bh(&mpath->state_lock);
541 goto fail;
542 }
543 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN);
544 spin_unlock_bh(&mpath->state_lock);
545 --ttl;
546 flags = PREP_IE_FLAGS(prep_elem);
547 lifetime = PREP_IE_LIFETIME(prep_elem);
548 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
549 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
550 dst_dsn = PREP_IE_DST_DSN(prep_elem);
551 orig_dsn = PREP_IE_ORIG_DSN(prep_elem);
552
553 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
554 cpu_to_le32(orig_dsn), 0, dst_addr,
555 cpu_to_le32(dst_dsn), mpath->next_hop->sta.addr, hopcount, ttl,
556 cpu_to_le32(lifetime), cpu_to_le32(metric),
557 0, sdata);
558 rcu_read_unlock();
559
560 sdata->u.mesh.mshstats.fwded_unicast++;
561 sdata->u.mesh.mshstats.fwded_frames++;
562 return;
563
564 fail:
565 rcu_read_unlock();
566 sdata->u.mesh.mshstats.dropped_frames_no_route++;
567 return;
568 }
569
570 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
571 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
572 {
573 struct mesh_path *mpath;
574 u8 *ta, *dst_addr;
575 u32 dst_dsn;
576
577 ta = mgmt->sa;
578 dst_addr = PERR_IE_DST_ADDR(perr_elem);
579 dst_dsn = PERR_IE_DST_DSN(perr_elem);
580 rcu_read_lock();
581 mpath = mesh_path_lookup(dst_addr, sdata);
582 if (mpath) {
583 spin_lock_bh(&mpath->state_lock);
584 if (mpath->flags & MESH_PATH_ACTIVE &&
585 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 &&
586 (!(mpath->flags & MESH_PATH_DSN_VALID) ||
587 DSN_GT(dst_dsn, mpath->dsn))) {
588 mpath->flags &= ~MESH_PATH_ACTIVE;
589 mpath->dsn = dst_dsn;
590 spin_unlock_bh(&mpath->state_lock);
591 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn),
592 sdata->dev->broadcast, sdata);
593 } else
594 spin_unlock_bh(&mpath->state_lock);
595 }
596 rcu_read_unlock();
597 }
598
599
600
601 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
602 struct ieee80211_mgmt *mgmt,
603 size_t len)
604 {
605 struct ieee802_11_elems elems;
606 size_t baselen;
607 u32 last_hop_metric;
608
609 /* need action_code */
610 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
611 return;
612
613 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
614 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
615 len - baselen, &elems);
616
617 switch (mgmt->u.action.u.mesh_action.action_code) {
618 case MPATH_PREQ:
619 if (!elems.preq || elems.preq_len != 37)
620 /* Right now we support just 1 destination and no AE */
621 return;
622 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq);
623 if (!last_hop_metric)
624 return;
625 hwmp_preq_frame_process(sdata, mgmt, elems.preq, last_hop_metric);
626 break;
627 case MPATH_PREP:
628 if (!elems.prep || elems.prep_len != 31)
629 /* Right now we support no AE */
630 return;
631 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep);
632 if (!last_hop_metric)
633 return;
634 hwmp_prep_frame_process(sdata, mgmt, elems.prep, last_hop_metric);
635 break;
636 case MPATH_PERR:
637 if (!elems.perr || elems.perr_len != 12)
638 /* Right now we support only one destination per PERR */
639 return;
640 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
641 default:
642 return;
643 }
644
645 }
646
647 /**
648 * mesh_queue_preq - queue a PREQ to a given destination
649 *
650 * @mpath: mesh path to discover
651 * @flags: special attributes of the PREQ to be sent
652 *
653 * Locking: the function must be called from within a rcu read lock block.
654 *
655 */
656 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
657 {
658 struct ieee80211_sub_if_data *sdata = mpath->sdata;
659 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
660 struct mesh_preq_queue *preq_node;
661
662 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
663 if (!preq_node) {
664 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n");
665 return;
666 }
667
668 spin_lock(&ifmsh->mesh_preq_queue_lock);
669 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
670 spin_unlock(&ifmsh->mesh_preq_queue_lock);
671 kfree(preq_node);
672 if (printk_ratelimit())
673 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n");
674 return;
675 }
676
677 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
678 preq_node->flags = flags;
679
680 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
681 ++ifmsh->preq_queue_len;
682 spin_unlock(&ifmsh->mesh_preq_queue_lock);
683
684 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
685 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work);
686
687 else if (time_before(jiffies, ifmsh->last_preq)) {
688 /* avoid long wait if did not send preqs for a long time
689 * and jiffies wrapped around
690 */
691 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
692 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work);
693 } else
694 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
695 min_preq_int_jiff(sdata));
696 }
697
698 /**
699 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
700 *
701 * @sdata: local mesh subif
702 */
703 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
704 {
705 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
706 struct mesh_preq_queue *preq_node;
707 struct mesh_path *mpath;
708 u8 ttl, dst_flags;
709 u32 lifetime;
710
711 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
712 if (!ifmsh->preq_queue_len ||
713 time_before(jiffies, ifmsh->last_preq +
714 min_preq_int_jiff(sdata))) {
715 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
716 return;
717 }
718
719 preq_node = list_first_entry(&ifmsh->preq_queue.list,
720 struct mesh_preq_queue, list);
721 list_del(&preq_node->list);
722 --ifmsh->preq_queue_len;
723 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
724
725 rcu_read_lock();
726 mpath = mesh_path_lookup(preq_node->dst, sdata);
727 if (!mpath)
728 goto enddiscovery;
729
730 spin_lock_bh(&mpath->state_lock);
731 if (preq_node->flags & PREQ_Q_F_START) {
732 if (mpath->flags & MESH_PATH_RESOLVING) {
733 spin_unlock_bh(&mpath->state_lock);
734 goto enddiscovery;
735 } else {
736 mpath->flags &= ~MESH_PATH_RESOLVED;
737 mpath->flags |= MESH_PATH_RESOLVING;
738 mpath->discovery_retries = 0;
739 mpath->discovery_timeout = disc_timeout_jiff(sdata);
740 }
741 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
742 mpath->flags & MESH_PATH_RESOLVED) {
743 mpath->flags &= ~MESH_PATH_RESOLVING;
744 spin_unlock_bh(&mpath->state_lock);
745 goto enddiscovery;
746 }
747
748 ifmsh->last_preq = jiffies;
749
750 if (time_after(jiffies, ifmsh->last_dsn_update +
751 net_traversal_jiffies(sdata)) ||
752 time_before(jiffies, ifmsh->last_dsn_update)) {
753 ++ifmsh->dsn;
754 sdata->u.mesh.last_dsn_update = jiffies;
755 }
756 lifetime = default_lifetime(sdata);
757 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
758 if (ttl == 0) {
759 sdata->u.mesh.mshstats.dropped_frames_ttl++;
760 spin_unlock_bh(&mpath->state_lock);
761 goto enddiscovery;
762 }
763
764 if (preq_node->flags & PREQ_Q_F_REFRESH)
765 dst_flags = MP_F_DO;
766 else
767 dst_flags = MP_F_RF;
768
769 spin_unlock_bh(&mpath->state_lock);
770 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr,
771 cpu_to_le32(ifmsh->dsn), dst_flags, mpath->dst,
772 cpu_to_le32(mpath->dsn), sdata->dev->broadcast, 0,
773 ttl, cpu_to_le32(lifetime), 0,
774 cpu_to_le32(ifmsh->preq_id++), sdata);
775 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
776
777 enddiscovery:
778 rcu_read_unlock();
779 kfree(preq_node);
780 }
781
782 /**
783 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
784 *
785 * @skb: 802.11 frame to be sent
786 * @sdata: network subif the frame will be sent through
787 *
788 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
789 * found, the function will start a path discovery and queue the frame so it is
790 * sent when the path is resolved. This means the caller must not free the skb
791 * in this case.
792 */
793 int mesh_nexthop_lookup(struct sk_buff *skb,
794 struct ieee80211_sub_if_data *sdata)
795 {
796 struct sk_buff *skb_to_free = NULL;
797 struct mesh_path *mpath;
798 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
799 u8 *dst_addr = hdr->addr3;
800 int err = 0;
801
802 rcu_read_lock();
803 mpath = mesh_path_lookup(dst_addr, sdata);
804
805 if (!mpath) {
806 mesh_path_add(dst_addr, sdata);
807 mpath = mesh_path_lookup(dst_addr, sdata);
808 if (!mpath) {
809 sdata->u.mesh.mshstats.dropped_frames_no_route++;
810 err = -ENOSPC;
811 goto endlookup;
812 }
813 }
814
815 if (mpath->flags & MESH_PATH_ACTIVE) {
816 if (time_after(jiffies, mpath->exp_time +
817 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time))
818 && !memcmp(sdata->dev->dev_addr, hdr->addr4,
819 ETH_ALEN)
820 && !(mpath->flags & MESH_PATH_RESOLVING)
821 && !(mpath->flags & MESH_PATH_FIXED)) {
822 mesh_queue_preq(mpath,
823 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
824 }
825 memcpy(hdr->addr1, mpath->next_hop->sta.addr,
826 ETH_ALEN);
827 } else {
828 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
829 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
830 /* Start discovery only if it is not running yet */
831 mesh_queue_preq(mpath, PREQ_Q_F_START);
832 }
833
834 if (skb_queue_len(&mpath->frame_queue) >=
835 MESH_FRAME_QUEUE_LEN)
836 skb_to_free = skb_dequeue(&mpath->frame_queue);
837
838 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
839 skb_queue_tail(&mpath->frame_queue, skb);
840 if (skb_to_free)
841 mesh_path_discard_frame(skb_to_free, sdata);
842 err = -ENOENT;
843 }
844
845 endlookup:
846 rcu_read_unlock();
847 return err;
848 }
849
850 void mesh_path_timer(unsigned long data)
851 {
852 struct ieee80211_sub_if_data *sdata;
853 struct mesh_path *mpath;
854
855 rcu_read_lock();
856 mpath = (struct mesh_path *) data;
857 mpath = rcu_dereference(mpath);
858 if (!mpath)
859 goto endmpathtimer;
860 sdata = mpath->sdata;
861
862 if (sdata->local->quiescing) {
863 rcu_read_unlock();
864 return;
865 }
866
867 spin_lock_bh(&mpath->state_lock);
868 if (mpath->flags & MESH_PATH_RESOLVED ||
869 (!(mpath->flags & MESH_PATH_RESOLVING)))
870 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
871 else if (mpath->discovery_retries < max_preq_retries(sdata)) {
872 ++mpath->discovery_retries;
873 mpath->discovery_timeout *= 2;
874 mesh_queue_preq(mpath, 0);
875 } else {
876 mpath->flags = 0;
877 mpath->exp_time = jiffies;
878 mesh_path_flush_pending(mpath);
879 }
880
881 spin_unlock_bh(&mpath->state_lock);
882 endmpathtimer:
883 rcu_read_unlock();
884 }
linux-next