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swiotlb: factor out copy to/from device
[linux-2.6.git] / net / mac80211 / mesh_hwmp.c
blob501c7831adb4469627c8b7cd0a8c3b067478ff3b
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 TU_TO_EXP_TIME(x) (jiffies + msecs_to_jiffies(x * 1024 / 1000))
62 #define MSEC_TO_TU(x) (x*1000/1024)
63 #define DSN_GT(x, y) ((long) (y) - (long) (x) < 0)
64 #define DSN_LT(x, y) ((long) (x) - (long) (y) < 0)
65
66 #define net_traversal_jiffies(s) \
67 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
68 #define default_lifetime(s) \
69 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
70 #define min_preq_int_jiff(s) \
71 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
72 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
73 #define disc_timeout_jiff(s) \
74 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
75
76 enum mpath_frame_type {
77 MPATH_PREQ = 0,
78 MPATH_PREP,
79 MPATH_PERR
80 };
81
82 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
83 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst,
84 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime,
85 __le32 metric, __le32 preq_id, struct ieee80211_sub_if_data *sdata)
86 {
87 struct ieee80211_local *local = sdata->local;
88 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
89 struct ieee80211_mgmt *mgmt;
90 u8 *pos;
91 int ie_len;
92
93 if (!skb)
94 return -1;
95 skb_reserve(skb, local->hw.extra_tx_headroom);
96 /* 25 is the size of the common mgmt part (24) plus the size of the
97 * common action part (1)
98 */
99 mgmt = (struct ieee80211_mgmt *)
100 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
101 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
102 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
103 IEEE80211_STYPE_ACTION);
104
105 memcpy(mgmt->da, da, ETH_ALEN);
106 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
107 /* BSSID is left zeroed, wildcard value */
108 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
109 mgmt->u.action.u.mesh_action.action_code = action;
110
111 switch (action) {
112 case MPATH_PREQ:
113 ie_len = 37;
114 pos = skb_put(skb, 2 + ie_len);
115 *pos++ = WLAN_EID_PREQ;
116 break;
117 case MPATH_PREP:
118 ie_len = 31;
119 pos = skb_put(skb, 2 + ie_len);
120 *pos++ = WLAN_EID_PREP;
121 break;
122 default:
123 kfree_skb(skb);
124 return -ENOTSUPP;
125 break;
126 }
127 *pos++ = ie_len;
128 *pos++ = flags;
129 *pos++ = hop_count;
130 *pos++ = ttl;
131 if (action == MPATH_PREQ) {
132 memcpy(pos, &preq_id, 4);
133 pos += 4;
134 }
135 memcpy(pos, orig_addr, ETH_ALEN);
136 pos += ETH_ALEN;
137 memcpy(pos, &orig_dsn, 4);
138 pos += 4;
139 memcpy(pos, &lifetime, 4);
140 pos += 4;
141 memcpy(pos, &metric, 4);
142 pos += 4;
143 if (action == MPATH_PREQ) {
144 /* destination count */
145 *pos++ = 1;
146 *pos++ = dst_flags;
147 }
148 memcpy(pos, dst, ETH_ALEN);
149 pos += ETH_ALEN;
150 memcpy(pos, &dst_dsn, 4);
151
152 ieee80211_tx_skb(sdata, skb, 0);
153 return 0;
154 }
155
156 /**
157 * mesh_send_path error - Sends a PERR mesh management frame
158 *
159 * @dst: broken destination
160 * @dst_dsn: dsn of the broken destination
161 * @ra: node this frame is addressed to
162 */
163 int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
164 struct ieee80211_sub_if_data *sdata)
165 {
166 struct ieee80211_local *local = sdata->local;
167 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
168 struct ieee80211_mgmt *mgmt;
169 u8 *pos;
170 int ie_len;
171
172 if (!skb)
173 return -1;
174 skb_reserve(skb, local->hw.extra_tx_headroom);
175 /* 25 is the size of the common mgmt part (24) plus the size of the
176 * common action part (1)
177 */
178 mgmt = (struct ieee80211_mgmt *)
179 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
180 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
181 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
182 IEEE80211_STYPE_ACTION);
183
184 memcpy(mgmt->da, ra, ETH_ALEN);
185 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
186 /* BSSID is left zeroed, wildcard value */
187 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
188 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR;
189 ie_len = 12;
190 pos = skb_put(skb, 2 + ie_len);
191 *pos++ = WLAN_EID_PERR;
192 *pos++ = ie_len;
193 /* mode flags, reserved */
194 *pos++ = 0;
195 /* number of destinations */
196 *pos++ = 1;
197 memcpy(pos, dst, ETH_ALEN);
198 pos += ETH_ALEN;
199 memcpy(pos, &dst_dsn, 4);
200
201 ieee80211_tx_skb(sdata, skb, 0);
202 return 0;
203 }
204
205 static u32 airtime_link_metric_get(struct ieee80211_local *local,
206 struct sta_info *sta)
207 {
208 struct ieee80211_supported_band *sband;
209 /* This should be adjusted for each device */
210 int device_constant = 1 << ARITH_SHIFT;
211 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
212 int s_unit = 1 << ARITH_SHIFT;
213 int rate, err;
214 u32 tx_time, estimated_retx;
215 u64 result;
216
217 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
218
219 if (sta->fail_avg >= 100)
220 return MAX_METRIC;
221 err = (sta->fail_avg << ARITH_SHIFT) / 100;
222
223 /* bitrate is in units of 100 Kbps, while we need rate in units of
224 * 1Mbps. This will be corrected on tx_time computation.
225 */
226 rate = sband->bitrates[sta->last_txrate_idx].bitrate;
227 tx_time = (device_constant + 10 * test_frame_len / rate);
228 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
229 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
230 return (u32)result;
231 }
232
233 /**
234 * hwmp_route_info_get - Update routing info to originator and transmitter
235 *
236 * @sdata: local mesh subif
237 * @mgmt: mesh management frame
238 * @hwmp_ie: hwmp information element (PREP or PREQ)
239 *
240 * This function updates the path routing information to the originator and the
241 * transmitter of a HWMP PREQ or PREP fram.
242 *
243 * Returns: metric to frame originator or 0 if the frame should not be further
244 * processed
245 *
246 * Notes: this function is the only place (besides user-provided info) where
247 * path routing information is updated.
248 */
249 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
250 struct ieee80211_mgmt *mgmt,
251 u8 *hwmp_ie)
252 {
253 struct ieee80211_local *local = sdata->local;
254 struct mesh_path *mpath;
255 struct sta_info *sta;
256 bool fresh_info;
257 u8 *orig_addr, *ta;
258 u32 orig_dsn, orig_metric;
259 unsigned long orig_lifetime, exp_time;
260 u32 last_hop_metric, new_metric;
261 bool process = true;
262 u8 action = mgmt->u.action.u.mesh_action.action_code;
263
264 rcu_read_lock();
265 sta = sta_info_get(local, mgmt->sa);
266 if (!sta) {
267 rcu_read_unlock();
268 return 0;
269 }
270
271 last_hop_metric = airtime_link_metric_get(local, sta);
272 /* Update and check originator routing info */
273 fresh_info = true;
274
275 switch (action) {
276 case MPATH_PREQ:
277 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
278 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
279 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
280 orig_metric = PREQ_IE_METRIC(hwmp_ie);
281 break;
282 case MPATH_PREP:
283 /* Originator here refers to the MP that was the destination in
284 * the Path Request. The draft refers to that MP as the
285 * destination address, even though usually it is the origin of
286 * the PREP frame. We divert from the nomenclature in the draft
287 * so that we can easily use a single function to gather path
288 * information from both PREQ and PREP frames.
289 */
290 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
291 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
292 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
293 orig_metric = PREP_IE_METRIC(hwmp_ie);
294 break;
295 default:
296 rcu_read_unlock();
297 return 0;
298 }
299 new_metric = orig_metric + last_hop_metric;
300 if (new_metric < orig_metric)
301 new_metric = MAX_METRIC;
302 exp_time = TU_TO_EXP_TIME(orig_lifetime);
303
304 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
305 /* This MP is the originator, we are not interested in this
306 * frame, except for updating transmitter's path info.
307 */
308 process = false;
309 fresh_info = false;
310 } else {
311 mpath = mesh_path_lookup(orig_addr, sdata);
312 if (mpath) {
313 spin_lock_bh(&mpath->state_lock);
314 if (mpath->flags & MESH_PATH_FIXED)
315 fresh_info = false;
316 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
317 (mpath->flags & MESH_PATH_DSN_VALID)) {
318 if (DSN_GT(mpath->dsn, orig_dsn) ||
319 (mpath->dsn == orig_dsn &&
320 action == MPATH_PREQ &&
321 new_metric > mpath->metric)) {
322 process = false;
323 fresh_info = false;
324 }
325 }
326 } else {
327 mesh_path_add(orig_addr, sdata);
328 mpath = mesh_path_lookup(orig_addr, sdata);
329 if (!mpath) {
330 rcu_read_unlock();
331 return 0;
332 }
333 spin_lock_bh(&mpath->state_lock);
334 }
335
336 if (fresh_info) {
337 mesh_path_assign_nexthop(mpath, sta);
338 mpath->flags |= MESH_PATH_DSN_VALID;
339 mpath->metric = new_metric;
340 mpath->dsn = orig_dsn;
341 mpath->exp_time = time_after(mpath->exp_time, exp_time)
342 ? mpath->exp_time : exp_time;
343 mesh_path_activate(mpath);
344 spin_unlock_bh(&mpath->state_lock);
345 mesh_path_tx_pending(mpath);
346 /* draft says preq_id should be saved to, but there does
347 * not seem to be any use for it, skipping by now
348 */
349 } else
350 spin_unlock_bh(&mpath->state_lock);
351 }
352
353 /* Update and check transmitter routing info */
354 ta = mgmt->sa;
355 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
356 fresh_info = false;
357 else {
358 fresh_info = true;
359
360 mpath = mesh_path_lookup(ta, sdata);
361 if (mpath) {
362 spin_lock_bh(&mpath->state_lock);
363 if ((mpath->flags & MESH_PATH_FIXED) ||
364 ((mpath->flags & MESH_PATH_ACTIVE) &&
365 (last_hop_metric > mpath->metric)))
366 fresh_info = false;
367 } else {
368 mesh_path_add(ta, sdata);
369 mpath = mesh_path_lookup(ta, sdata);
370 if (!mpath) {
371 rcu_read_unlock();
372 return 0;
373 }
374 spin_lock_bh(&mpath->state_lock);
375 }
376
377 if (fresh_info) {
378 mesh_path_assign_nexthop(mpath, sta);
379 mpath->flags &= ~MESH_PATH_DSN_VALID;
380 mpath->metric = last_hop_metric;
381 mpath->exp_time = time_after(mpath->exp_time, exp_time)
382 ? mpath->exp_time : exp_time;
383 mesh_path_activate(mpath);
384 spin_unlock_bh(&mpath->state_lock);
385 mesh_path_tx_pending(mpath);
386 } else
387 spin_unlock_bh(&mpath->state_lock);
388 }
389
390 rcu_read_unlock();
391
392 return process ? new_metric : 0;
393 }
394
395 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
396 struct ieee80211_mgmt *mgmt,
397 u8 *preq_elem, u32 metric) {
398 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
399 struct mesh_path *mpath;
400 u8 *dst_addr, *orig_addr;
401 u8 dst_flags, ttl;
402 u32 orig_dsn, dst_dsn, lifetime;
403 bool reply = false;
404 bool forward = true;
405
406 /* Update destination DSN, if present */
407 dst_addr = PREQ_IE_DST_ADDR(preq_elem);
408 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
409 dst_dsn = PREQ_IE_DST_DSN(preq_elem);
410 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem);
411 dst_flags = PREQ_IE_DST_F(preq_elem);
412
413 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
414 forward = false;
415 reply = true;
416 metric = 0;
417 if (time_after(jiffies, ifmsh->last_dsn_update +
418 net_traversal_jiffies(sdata)) ||
419 time_before(jiffies, ifmsh->last_dsn_update)) {
420 dst_dsn = ++ifmsh->dsn;
421 ifmsh->last_dsn_update = jiffies;
422 }
423 } else {
424 rcu_read_lock();
425 mpath = mesh_path_lookup(dst_addr, sdata);
426 if (mpath) {
427 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) ||
428 DSN_LT(mpath->dsn, dst_dsn)) {
429 mpath->dsn = dst_dsn;
430 mpath->flags &= MESH_PATH_DSN_VALID;
431 } else if ((!(dst_flags & MP_F_DO)) &&
432 (mpath->flags & MESH_PATH_ACTIVE)) {
433 reply = true;
434 metric = mpath->metric;
435 dst_dsn = mpath->dsn;
436 if (dst_flags & MP_F_RF)
437 dst_flags |= MP_F_DO;
438 else
439 forward = false;
440 }
441 }
442 rcu_read_unlock();
443 }
444
445 if (reply) {
446 lifetime = PREQ_IE_LIFETIME(preq_elem);
447 ttl = ifmsh->mshcfg.dot11MeshTTL;
448 if (ttl != 0)
449 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr,
450 cpu_to_le32(dst_dsn), 0, orig_addr,
451 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl,
452 cpu_to_le32(lifetime), cpu_to_le32(metric),
453 0, sdata);
454 else
455 ifmsh->mshstats.dropped_frames_ttl++;
456 }
457
458 if (forward) {
459 u32 preq_id;
460 u8 hopcount, flags;
461
462 ttl = PREQ_IE_TTL(preq_elem);
463 lifetime = PREQ_IE_LIFETIME(preq_elem);
464 if (ttl <= 1) {
465 ifmsh->mshstats.dropped_frames_ttl++;
466 return;
467 }
468 --ttl;
469 flags = PREQ_IE_FLAGS(preq_elem);
470 preq_id = PREQ_IE_PREQ_ID(preq_elem);
471 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
472 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
473 cpu_to_le32(orig_dsn), dst_flags, dst_addr,
474 cpu_to_le32(dst_dsn), sdata->dev->broadcast,
475 hopcount, ttl, cpu_to_le32(lifetime),
476 cpu_to_le32(metric), cpu_to_le32(preq_id),
477 sdata);
478 ifmsh->mshstats.fwded_frames++;
479 }
480 }
481
482
483 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
484 struct ieee80211_mgmt *mgmt,
485 u8 *prep_elem, u32 metric)
486 {
487 struct mesh_path *mpath;
488 u8 *dst_addr, *orig_addr;
489 u8 ttl, hopcount, flags;
490 u8 next_hop[ETH_ALEN];
491 u32 dst_dsn, orig_dsn, lifetime;
492
493 /* Note that we divert from the draft nomenclature and denominate
494 * destination to what the draft refers to as origininator. So in this
495 * function destnation refers to the final destination of the PREP,
496 * which corresponds with the originator of the PREQ which this PREP
497 * replies
498 */
499 dst_addr = PREP_IE_DST_ADDR(prep_elem);
500 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0)
501 /* destination, no forwarding required */
502 return;
503
504 ttl = PREP_IE_TTL(prep_elem);
505 if (ttl <= 1) {
506 sdata->u.mesh.mshstats.dropped_frames_ttl++;
507 return;
508 }
509
510 rcu_read_lock();
511 mpath = mesh_path_lookup(dst_addr, sdata);
512 if (mpath)
513 spin_lock_bh(&mpath->state_lock);
514 else
515 goto fail;
516 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
517 spin_unlock_bh(&mpath->state_lock);
518 goto fail;
519 }
520 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN);
521 spin_unlock_bh(&mpath->state_lock);
522 --ttl;
523 flags = PREP_IE_FLAGS(prep_elem);
524 lifetime = PREP_IE_LIFETIME(prep_elem);
525 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
526 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
527 dst_dsn = PREP_IE_DST_DSN(prep_elem);
528 orig_dsn = PREP_IE_ORIG_DSN(prep_elem);
529
530 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
531 cpu_to_le32(orig_dsn), 0, dst_addr,
532 cpu_to_le32(dst_dsn), mpath->next_hop->sta.addr, hopcount, ttl,
533 cpu_to_le32(lifetime), cpu_to_le32(metric),
534 0, sdata);
535 rcu_read_unlock();
536 sdata->u.mesh.mshstats.fwded_frames++;
537 return;
538
539 fail:
540 rcu_read_unlock();
541 sdata->u.mesh.mshstats.dropped_frames_no_route++;
542 return;
543 }
544
545 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
546 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
547 {
548 struct mesh_path *mpath;
549 u8 *ta, *dst_addr;
550 u32 dst_dsn;
551
552 ta = mgmt->sa;
553 dst_addr = PERR_IE_DST_ADDR(perr_elem);
554 dst_dsn = PERR_IE_DST_DSN(perr_elem);
555 rcu_read_lock();
556 mpath = mesh_path_lookup(dst_addr, sdata);
557 if (mpath) {
558 spin_lock_bh(&mpath->state_lock);
559 if (mpath->flags & MESH_PATH_ACTIVE &&
560 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 &&
561 (!(mpath->flags & MESH_PATH_DSN_VALID) ||
562 DSN_GT(dst_dsn, mpath->dsn))) {
563 mpath->flags &= ~MESH_PATH_ACTIVE;
564 mpath->dsn = dst_dsn;
565 spin_unlock_bh(&mpath->state_lock);
566 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn),
567 sdata->dev->broadcast, sdata);
568 } else
569 spin_unlock_bh(&mpath->state_lock);
570 }
571 rcu_read_unlock();
572 }
573
574
575
576 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
577 struct ieee80211_mgmt *mgmt,
578 size_t len)
579 {
580 struct ieee802_11_elems elems;
581 size_t baselen;
582 u32 last_hop_metric;
583
584 /* need action_code */
585 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
586 return;
587
588 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
589 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
590 len - baselen, &elems);
591
592 switch (mgmt->u.action.u.mesh_action.action_code) {
593 case MPATH_PREQ:
594 if (!elems.preq || elems.preq_len != 37)
595 /* Right now we support just 1 destination and no AE */
596 return;
597 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq);
598 if (!last_hop_metric)
599 return;
600 hwmp_preq_frame_process(sdata, mgmt, elems.preq, last_hop_metric);
601 break;
602 case MPATH_PREP:
603 if (!elems.prep || elems.prep_len != 31)
604 /* Right now we support no AE */
605 return;
606 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep);
607 if (!last_hop_metric)
608 return;
609 hwmp_prep_frame_process(sdata, mgmt, elems.prep, last_hop_metric);
610 break;
611 case MPATH_PERR:
612 if (!elems.perr || elems.perr_len != 12)
613 /* Right now we support only one destination per PERR */
614 return;
615 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
616 default:
617 return;
618 }
619
620 }
621
622 /**
623 * mesh_queue_preq - queue a PREQ to a given destination
624 *
625 * @mpath: mesh path to discover
626 * @flags: special attributes of the PREQ to be sent
627 *
628 * Locking: the function must be called from within a rcu read lock block.
629 *
630 */
631 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
632 {
633 struct ieee80211_sub_if_data *sdata = mpath->sdata;
634 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
635 struct mesh_preq_queue *preq_node;
636
637 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL);
638 if (!preq_node) {
639 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n");
640 return;
641 }
642
643 spin_lock(&ifmsh->mesh_preq_queue_lock);
644 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
645 spin_unlock(&ifmsh->mesh_preq_queue_lock);
646 kfree(preq_node);
647 if (printk_ratelimit())
648 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n");
649 return;
650 }
651
652 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
653 preq_node->flags = flags;
654
655 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
656 ++ifmsh->preq_queue_len;
657 spin_unlock(&ifmsh->mesh_preq_queue_lock);
658
659 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
660 queue_work(sdata->local->hw.workqueue, &ifmsh->work);
661
662 else if (time_before(jiffies, ifmsh->last_preq)) {
663 /* avoid long wait if did not send preqs for a long time
664 * and jiffies wrapped around
665 */
666 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
667 queue_work(sdata->local->hw.workqueue, &ifmsh->work);
668 } else
669 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
670 min_preq_int_jiff(sdata));
671 }
672
673 /**
674 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
675 *
676 * @sdata: local mesh subif
677 */
678 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
679 {
680 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
681 struct mesh_preq_queue *preq_node;
682 struct mesh_path *mpath;
683 u8 ttl, dst_flags;
684 u32 lifetime;
685
686 spin_lock(&ifmsh->mesh_preq_queue_lock);
687 if (!ifmsh->preq_queue_len ||
688 time_before(jiffies, ifmsh->last_preq +
689 min_preq_int_jiff(sdata))) {
690 spin_unlock(&ifmsh->mesh_preq_queue_lock);
691 return;
692 }
693
694 preq_node = list_first_entry(&ifmsh->preq_queue.list,
695 struct mesh_preq_queue, list);
696 list_del(&preq_node->list);
697 --ifmsh->preq_queue_len;
698 spin_unlock(&ifmsh->mesh_preq_queue_lock);
699
700 rcu_read_lock();
701 mpath = mesh_path_lookup(preq_node->dst, sdata);
702 if (!mpath)
703 goto enddiscovery;
704
705 spin_lock_bh(&mpath->state_lock);
706 if (preq_node->flags & PREQ_Q_F_START) {
707 if (mpath->flags & MESH_PATH_RESOLVING) {
708 spin_unlock_bh(&mpath->state_lock);
709 goto enddiscovery;
710 } else {
711 mpath->flags &= ~MESH_PATH_RESOLVED;
712 mpath->flags |= MESH_PATH_RESOLVING;
713 mpath->discovery_retries = 0;
714 mpath->discovery_timeout = disc_timeout_jiff(sdata);
715 }
716 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
717 mpath->flags & MESH_PATH_RESOLVED) {
718 mpath->flags &= ~MESH_PATH_RESOLVING;
719 spin_unlock_bh(&mpath->state_lock);
720 goto enddiscovery;
721 }
722
723 ifmsh->last_preq = jiffies;
724
725 if (time_after(jiffies, ifmsh->last_dsn_update +
726 net_traversal_jiffies(sdata)) ||
727 time_before(jiffies, ifmsh->last_dsn_update)) {
728 ++ifmsh->dsn;
729 sdata->u.mesh.last_dsn_update = jiffies;
730 }
731 lifetime = default_lifetime(sdata);
732 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
733 if (ttl == 0) {
734 sdata->u.mesh.mshstats.dropped_frames_ttl++;
735 spin_unlock_bh(&mpath->state_lock);
736 goto enddiscovery;
737 }
738
739 if (preq_node->flags & PREQ_Q_F_REFRESH)
740 dst_flags = MP_F_DO;
741 else
742 dst_flags = MP_F_RF;
743
744 spin_unlock_bh(&mpath->state_lock);
745 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr,
746 cpu_to_le32(ifmsh->dsn), dst_flags, mpath->dst,
747 cpu_to_le32(mpath->dsn), sdata->dev->broadcast, 0,
748 ttl, cpu_to_le32(lifetime), 0,
749 cpu_to_le32(ifmsh->preq_id++), sdata);
750 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
751
752 enddiscovery:
753 rcu_read_unlock();
754 kfree(preq_node);
755 }
756
757 /**
758 * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame
759 *
760 * @skb: 802.11 frame to be sent
761 * @sdata: network subif the frame will be sent through
762 * @fwd_frame: true if this frame was originally from a different host
763 *
764 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
765 * found, the function will start a path discovery and queue the frame so it is
766 * sent when the path is resolved. This means the caller must not free the skb
767 * in this case.
768 */
769 int mesh_nexthop_lookup(struct sk_buff *skb,
770 struct ieee80211_sub_if_data *sdata)
771 {
772 struct sk_buff *skb_to_free = NULL;
773 struct mesh_path *mpath;
774 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
775 u8 *dst_addr = hdr->addr3;
776 int err = 0;
777
778 rcu_read_lock();
779 mpath = mesh_path_lookup(dst_addr, sdata);
780
781 if (!mpath) {
782 mesh_path_add(dst_addr, sdata);
783 mpath = mesh_path_lookup(dst_addr, sdata);
784 if (!mpath) {
785 dev_kfree_skb(skb);
786 sdata->u.mesh.mshstats.dropped_frames_no_route++;
787 err = -ENOSPC;
788 goto endlookup;
789 }
790 }
791
792 if (mpath->flags & MESH_PATH_ACTIVE) {
793 if (time_after(jiffies, mpath->exp_time -
794 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time))
795 && !memcmp(sdata->dev->dev_addr, hdr->addr4,
796 ETH_ALEN)
797 && !(mpath->flags & MESH_PATH_RESOLVING)
798 && !(mpath->flags & MESH_PATH_FIXED)) {
799 mesh_queue_preq(mpath,
800 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
801 }
802 memcpy(hdr->addr1, mpath->next_hop->sta.addr,
803 ETH_ALEN);
804 } else {
805 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
806 /* Start discovery only if it is not running yet */
807 mesh_queue_preq(mpath, PREQ_Q_F_START);
808 }
809
810 if (skb_queue_len(&mpath->frame_queue) >=
811 MESH_FRAME_QUEUE_LEN) {
812 skb_to_free = mpath->frame_queue.next;
813 skb_unlink(skb_to_free, &mpath->frame_queue);
814 }
815
816 skb_queue_tail(&mpath->frame_queue, skb);
817 if (skb_to_free)
818 mesh_path_discard_frame(skb_to_free, sdata);
819 err = -ENOENT;
820 }
821
822 endlookup:
823 rcu_read_unlock();
824 return err;
825 }
826
827 void mesh_path_timer(unsigned long data)
828 {
829 struct ieee80211_sub_if_data *sdata;
830 struct mesh_path *mpath;
831
832 rcu_read_lock();
833 mpath = (struct mesh_path *) data;
834 mpath = rcu_dereference(mpath);
835 if (!mpath)
836 goto endmpathtimer;
837 spin_lock_bh(&mpath->state_lock);
838 sdata = mpath->sdata;
839 if (mpath->flags & MESH_PATH_RESOLVED ||
840 (!(mpath->flags & MESH_PATH_RESOLVING)))
841 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
842 else if (mpath->discovery_retries < max_preq_retries(sdata)) {
843 ++mpath->discovery_retries;
844 mpath->discovery_timeout *= 2;
845 mesh_queue_preq(mpath, 0);
846 } else {
847 mpath->flags = 0;
848 mpath->exp_time = jiffies;
849 mesh_path_flush_pending(mpath);
850 }
851
852 spin_unlock_bh(&mpath->state_lock);
853 endmpathtimer:
854 rcu_read_unlock();
855 }
Linus' kernel tree