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-rw-r--r--net/mac80211/mesh_hwmp.c855
1 files changed, 855 insertions, 0 deletions
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
new file mode 100644
index 000000000000..02de8f1522a3
--- /dev/null
+++ b/net/mac80211/mesh_hwmp.c
@@ -0,0 +1,855 @@
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 <asm/unaligned.h>
11#include "mesh.h"
12
13#define TEST_FRAME_LEN 8192
14#define MAX_METRIC 0xffffffff
15#define ARITH_SHIFT 8
16
17/* Number of frames buffered per destination for unresolved destinations */
18#define MESH_FRAME_QUEUE_LEN 10
19#define MAX_PREQ_QUEUE_LEN 64
20
21/* Destination only */
22#define MP_F_DO 0x1
23/* Reply and forward */
24#define MP_F_RF 0x2
25
26static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
27{
28 if (ae)
29 offset += 6;
30 return le32_to_cpu(get_unaligned((__le32 *) (preq_elem + offset)));
31}
32
33/* HWMP IE processing macros */
34#define AE_F (1<<6)
35#define AE_F_SET(x) (*x & AE_F)
36#define PREQ_IE_FLAGS(x) (*(x))
37#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
38#define PREQ_IE_TTL(x) (*(x + 2))
39#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
40#define PREQ_IE_ORIG_ADDR(x) (x + 7)
41#define PREQ_IE_ORIG_DSN(x) u32_field_get(x, 13, 0);
42#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x));
43#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x));
44#define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
45#define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
46#define PREQ_IE_DST_DSN(x) u32_field_get(x, 33, AE_F_SET(x));
47
48
49#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
50#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
51#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
52#define PREP_IE_ORIG_ADDR(x) (x + 3)
53#define PREP_IE_ORIG_DSN(x) u32_field_get(x, 9, 0);
54#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x));
55#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x));
56#define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
57#define PREP_IE_DST_DSN(x) u32_field_get(x, 27, AE_F_SET(x));
58
59#define PERR_IE_DST_ADDR(x) (x + 2)
60#define PERR_IE_DST_DSN(x) u32_field_get(x, 8, 0);
61
62#define TU_TO_EXP_TIME(x) (jiffies + msecs_to_jiffies(x * 1024 / 1000))
63#define MSEC_TO_TU(x) (x*1000/1024)
64#define DSN_GT(x, y) ((long) (y) - (long) (x) < 0)
65#define DSN_LT(x, y) ((long) (x) - (long) (y) < 0)
66
67#define net_traversal_jiffies(s) \
68 msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
69#define default_lifetime(s) \
70 MSEC_TO_TU(s->u.sta.mshcfg.dot11MeshHWMPactivePathTimeout)
71#define min_preq_int_jiff(s) \
72 (msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPpreqMinInterval))
73#define max_preq_retries(s) (s->u.sta.mshcfg.dot11MeshHWMPmaxPREQretries)
74#define disc_timeout_jiff(s) \
75 msecs_to_jiffies(sdata->u.sta.mshcfg.min_discovery_timeout)
76
77enum mpath_frame_type {
78 MPATH_PREQ = 0,
79 MPATH_PREP,
80 MPATH_PERR
81};
82
83static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
84 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst,
85 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime,
86 __le32 metric, __le32 preq_id, struct net_device *dev)
87{
88 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
89 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
90 struct ieee80211_mgmt *mgmt;
91 u8 *pos;
92 int ie_len;
93
94 if (!skb)
95 return -1;
96 skb_reserve(skb, local->hw.extra_tx_headroom);
97 /* 25 is the size of the common mgmt part (24) plus the size of the
98 * common action part (1)
99 */
100 mgmt = (struct ieee80211_mgmt *)
101 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
102 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
103 mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
104 IEEE80211_STYPE_ACTION);
105
106 memcpy(mgmt->da, da, ETH_ALEN);
107 memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
108 /* BSSID is left zeroed, wildcard value */
109 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
110 mgmt->u.action.u.mesh_action.action_code = action;
111
112 switch (action) {
113 case MPATH_PREQ:
114 ie_len = 37;
115 pos = skb_put(skb, 2 + ie_len);
116 *pos++ = WLAN_EID_PREQ;
117 break;
118 case MPATH_PREP:
119 ie_len = 31;
120 pos = skb_put(skb, 2 + ie_len);
121 *pos++ = WLAN_EID_PREP;
122 break;
123 default:
124 kfree(skb);
125 return -ENOTSUPP;
126 break;
127 }
128 *pos++ = ie_len;
129 *pos++ = flags;
130 *pos++ = hop_count;
131 *pos++ = ttl;
132 if (action == MPATH_PREQ) {
133 memcpy(pos, &preq_id, 4);
134 pos += 4;
135 }
136 memcpy(pos, orig_addr, ETH_ALEN);
137 pos += ETH_ALEN;
138 memcpy(pos, &orig_dsn, 4);
139 pos += 4;
140 memcpy(pos, &lifetime, 4);
141 pos += 4;
142 memcpy(pos, &metric, 4);
143 pos += 4;
144 if (action == MPATH_PREQ) {
145 /* destination count */
146 *pos++ = 1;
147 *pos++ = dst_flags;
148 }
149 memcpy(pos, dst, ETH_ALEN);
150 pos += ETH_ALEN;
151 memcpy(pos, &dst_dsn, 4);
152
153 ieee80211_sta_tx(dev, skb, 0);
154 return 0;
155}
156
157/**
158 * mesh_send_path error - Sends a PERR mesh management frame
159 *
160 * @dst: broken destination
161 * @dst_dsn: dsn of the broken destination
162 * @ra: node this frame is addressed to
163 */
164int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
165 struct net_device *dev)
166{
167 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
168 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
169 struct ieee80211_mgmt *mgmt;
170 u8 *pos;
171 int ie_len;
172
173 if (!skb)
174 return -1;
175 skb_reserve(skb, local->hw.extra_tx_headroom);
176 /* 25 is the size of the common mgmt part (24) plus the size of the
177 * common action part (1)
178 */
179 mgmt = (struct ieee80211_mgmt *)
180 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
181 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
182 mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
183 IEEE80211_STYPE_ACTION);
184
185 memcpy(mgmt->da, ra, ETH_ALEN);
186 memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
187 /* BSSID is left zeroed, wildcard value */
188 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
189 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR;
190 ie_len = 12;
191 pos = skb_put(skb, 2 + ie_len);
192 *pos++ = WLAN_EID_PERR;
193 *pos++ = ie_len;
194 /* mode flags, reserved */
195 *pos++ = 0;
196 /* number of destinations */
197 *pos++ = 1;
198 memcpy(pos, dst, ETH_ALEN);
199 pos += ETH_ALEN;
200 memcpy(pos, &dst_dsn, 4);
201
202 ieee80211_sta_tx(dev, skb, 0);
203 return 0;
204}
205
206static u32 airtime_link_metric_get(struct ieee80211_local *local,
207 struct sta_info *sta)
208{
209 struct ieee80211_supported_band *sband;
210 /* This should be adjusted for each device */
211 int device_constant = 1 << ARITH_SHIFT;
212 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
213 int s_unit = 1 << ARITH_SHIFT;
214 int rate, err;
215 u32 tx_time, estimated_retx;
216 u64 result;
217
218 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
219
220 if (sta->fail_avg >= 100)
221 return MAX_METRIC;
222 err = (sta->fail_avg << ARITH_SHIFT) / 100;
223
224 /* bitrate is in units of 100 Kbps, while we need rate in units of
225 * 1Mbps. This will be corrected on tx_time computation.
226 */
227 rate = sband->bitrates[sta->txrate_idx].bitrate;
228 tx_time = (device_constant + 10 * test_frame_len / rate);
229 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
230 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
231 return (u32)result;
232}
233
234/**
235 * hwmp_route_info_get - Update routing info to originator and transmitter
236 *
237 * @dev: local mesh interface
238 * @mgmt: mesh management frame
239 * @hwmp_ie: hwmp information element (PREP or PREQ)
240 *
241 * This function updates the path routing information to the originator and the
242 * transmitter of a HWMP PREQ or PREP fram.
243 *
244 * Returns: metric to frame originator or 0 if the frame should not be further
245 * processed
246 *
247 * Notes: this function is the only place (besides user-provided info) where
248 * path routing information is updated.
249 */
250static u32 hwmp_route_info_get(struct net_device *dev,
251 struct ieee80211_mgmt *mgmt,
252 u8 *hwmp_ie)
253{
254 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
255 struct mesh_path *mpath;
256 struct sta_info *sta;
257 bool fresh_info;
258 u8 *orig_addr, *ta;
259 u32 orig_dsn, orig_metric;
260 unsigned long orig_lifetime, exp_time;
261 u32 last_hop_metric, new_metric;
262 bool process = true;
263 u8 action = mgmt->u.action.u.mesh_action.action_code;
264
265 rcu_read_lock();
266 sta = sta_info_get(local, mgmt->sa);
267 if (!sta) {
268 rcu_read_unlock();
269 return 0;
270 }
271
272 last_hop_metric = airtime_link_metric_get(local, sta);
273 /* Update and check originator routing info */
274 fresh_info = true;
275
276 switch (action) {
277 case MPATH_PREQ:
278 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
279 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
280 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
281 orig_metric = PREQ_IE_METRIC(hwmp_ie);
282 break;
283 case MPATH_PREP:
284 /* Originator here refers to the MP that was the destination in
285 * the Path Request. The draft refers to that MP as the
286 * destination address, even though usually it is the origin of
287 * the PREP frame. We divert from the nomenclature in the draft
288 * so that we can easily use a single function to gather path
289 * information from both PREQ and PREP frames.
290 */
291 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
292 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
293 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
294 orig_metric = PREP_IE_METRIC(hwmp_ie);
295 break;
296 default:
297 rcu_read_unlock();
298 return 0;
299 }
300 new_metric = orig_metric + last_hop_metric;
301 if (new_metric < orig_metric)
302 new_metric = MAX_METRIC;
303 exp_time = TU_TO_EXP_TIME(orig_lifetime);
304
305 if (memcmp(orig_addr, dev->dev_addr, ETH_ALEN) == 0) {
306 /* This MP is the originator, we are not interested in this
307 * frame, except for updating transmitter's path info.
308 */
309 process = false;
310 fresh_info = false;
311 } else {
312 mpath = mesh_path_lookup(orig_addr, dev);
313 if (mpath) {
314 spin_lock_bh(&mpath->state_lock);
315 if (mpath->flags & MESH_PATH_FIXED)
316 fresh_info = false;
317 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
318 (mpath->flags & MESH_PATH_DSN_VALID)) {
319 if (DSN_GT(mpath->dsn, orig_dsn) ||
320 (mpath->dsn == orig_dsn &&
321 action == MPATH_PREQ &&
322 new_metric > mpath->metric)) {
323 process = false;
324 fresh_info = false;
325 }
326 }
327 } else {
328 mesh_path_add(orig_addr, dev);
329 mpath = mesh_path_lookup(orig_addr, dev);
330 if (!mpath) {
331 rcu_read_unlock();
332 return 0;
333 }
334 spin_lock_bh(&mpath->state_lock);
335 }
336
337 if (fresh_info) {
338 mesh_path_assign_nexthop(mpath, sta);
339 mpath->flags |= MESH_PATH_DSN_VALID;
340 mpath->metric = new_metric;
341 mpath->dsn = orig_dsn;
342 mpath->exp_time = time_after(mpath->exp_time, exp_time)
343 ? mpath->exp_time : exp_time;
344 mesh_path_activate(mpath);
345 spin_unlock_bh(&mpath->state_lock);
346 mesh_path_tx_pending(mpath);
347 /* draft says preq_id should be saved to, but there does
348 * not seem to be any use for it, skipping by now
349 */
350 } else
351 spin_unlock_bh(&mpath->state_lock);
352 }
353
354 /* Update and check transmitter routing info */
355 ta = mgmt->sa;
356 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
357 fresh_info = false;
358 else {
359 fresh_info = true;
360
361 mpath = mesh_path_lookup(ta, dev);
362 if (mpath) {
363 spin_lock_bh(&mpath->state_lock);
364 if ((mpath->flags & MESH_PATH_FIXED) ||
365 ((mpath->flags & MESH_PATH_ACTIVE) &&
366 (last_hop_metric > mpath->metric)))
367 fresh_info = false;
368 } else {
369 mesh_path_add(ta, dev);
370 mpath = mesh_path_lookup(ta, dev);
371 if (!mpath) {
372 rcu_read_unlock();
373 return 0;
374 }
375 spin_lock_bh(&mpath->state_lock);
376 }
377
378 if (fresh_info) {
379 mesh_path_assign_nexthop(mpath, sta);
380 mpath->flags &= ~MESH_PATH_DSN_VALID;
381 mpath->metric = last_hop_metric;
382 mpath->exp_time = time_after(mpath->exp_time, exp_time)
383 ? mpath->exp_time : exp_time;
384 mesh_path_activate(mpath);
385 spin_unlock_bh(&mpath->state_lock);
386 mesh_path_tx_pending(mpath);
387 } else
388 spin_unlock_bh(&mpath->state_lock);
389 }
390
391 rcu_read_unlock();
392
393 return process ? new_metric : 0;
394}
395
396static void hwmp_preq_frame_process(struct net_device *dev,
397 struct ieee80211_mgmt *mgmt,
398 u8 *preq_elem, u32 metric) {
399 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
400 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
401 struct mesh_path *mpath;
402 u8 *dst_addr, *orig_addr;
403 u8 dst_flags, ttl;
404 u32 orig_dsn, dst_dsn, lifetime;
405 bool reply = false;
406 bool forward = true;
407
408 /* Update destination DSN, if present */
409 dst_addr = PREQ_IE_DST_ADDR(preq_elem);
410 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
411 dst_dsn = PREQ_IE_DST_DSN(preq_elem);
412 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem);
413 dst_flags = PREQ_IE_DST_F(preq_elem);
414
415 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0) {
416 forward = false;
417 reply = true;
418 metric = 0;
419 if (time_after(jiffies, ifsta->last_dsn_update +
420 net_traversal_jiffies(sdata)) ||
421 time_before(jiffies, ifsta->last_dsn_update)) {
422 dst_dsn = ++ifsta->dsn;
423 ifsta->last_dsn_update = jiffies;
424 }
425 } else {
426 rcu_read_lock();
427 mpath = mesh_path_lookup(dst_addr, dev);
428 if (mpath) {
429 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) ||
430 DSN_LT(mpath->dsn, dst_dsn)) {
431 mpath->dsn = dst_dsn;
432 mpath->flags &= MESH_PATH_DSN_VALID;
433 } else if ((!(dst_flags & MP_F_DO)) &&
434 (mpath->flags & MESH_PATH_ACTIVE)) {
435 reply = true;
436 metric = mpath->metric;
437 dst_dsn = mpath->dsn;
438 if (dst_flags & MP_F_RF)
439 dst_flags |= MP_F_DO;
440 else
441 forward = false;
442 }
443 }
444 rcu_read_unlock();
445 }
446
447 if (reply) {
448 lifetime = PREQ_IE_LIFETIME(preq_elem);
449 ttl = ifsta->mshcfg.dot11MeshTTL;
450 if (ttl != 0)
451 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr,
452 cpu_to_le32(dst_dsn), 0, orig_addr,
453 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl,
454 cpu_to_le32(lifetime), cpu_to_le32(metric),
455 0, dev);
456 else
457 ifsta->mshstats.dropped_frames_ttl++;
458 }
459
460 if (forward) {
461 u32 preq_id;
462 u8 hopcount, flags;
463
464 ttl = PREQ_IE_TTL(preq_elem);
465 lifetime = PREQ_IE_LIFETIME(preq_elem);
466 if (ttl <= 1) {
467 ifsta->mshstats.dropped_frames_ttl++;
468 return;
469 }
470 --ttl;
471 flags = PREQ_IE_FLAGS(preq_elem);
472 preq_id = PREQ_IE_PREQ_ID(preq_elem);
473 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
474 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
475 cpu_to_le32(orig_dsn), dst_flags, dst_addr,
476 cpu_to_le32(dst_dsn), dev->broadcast,
477 hopcount, ttl, cpu_to_le32(lifetime),
478 cpu_to_le32(metric), cpu_to_le32(preq_id),
479 dev);
480 ifsta->mshstats.fwded_frames++;
481 }
482}
483
484
485static void hwmp_prep_frame_process(struct net_device *dev,
486 struct ieee80211_mgmt *mgmt,
487 u8 *prep_elem, u32 metric)
488{
489 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
490 struct mesh_path *mpath;
491 u8 *dst_addr, *orig_addr;
492 u8 ttl, hopcount, flags;
493 u8 next_hop[ETH_ALEN];
494 u32 dst_dsn, orig_dsn, lifetime;
495
496 /* Note that we divert from the draft nomenclature and denominate
497 * destination to what the draft refers to as origininator. So in this
498 * function destnation refers to the final destination of the PREP,
499 * which corresponds with the originator of the PREQ which this PREP
500 * replies
501 */
502 dst_addr = PREP_IE_DST_ADDR(prep_elem);
503 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0)
504 /* destination, no forwarding required */
505 return;
506
507 ttl = PREP_IE_TTL(prep_elem);
508 if (ttl <= 1) {
509 sdata->u.sta.mshstats.dropped_frames_ttl++;
510 return;
511 }
512
513 rcu_read_lock();
514 mpath = mesh_path_lookup(dst_addr, dev);
515 if (mpath)
516 spin_lock_bh(&mpath->state_lock);
517 else
518 goto fail;
519 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
520 spin_unlock_bh(&mpath->state_lock);
521 goto fail;
522 }
523 memcpy(next_hop, mpath->next_hop->addr, ETH_ALEN);
524 spin_unlock_bh(&mpath->state_lock);
525 --ttl;
526 flags = PREP_IE_FLAGS(prep_elem);
527 lifetime = PREP_IE_LIFETIME(prep_elem);
528 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
529 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
530 dst_dsn = PREP_IE_DST_DSN(prep_elem);
531 orig_dsn = PREP_IE_ORIG_DSN(prep_elem);
532
533 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
534 cpu_to_le32(orig_dsn), 0, dst_addr,
535 cpu_to_le32(dst_dsn), mpath->next_hop->addr, hopcount, ttl,
536 cpu_to_le32(lifetime), cpu_to_le32(metric),
537 0, dev);
538 rcu_read_unlock();
539 sdata->u.sta.mshstats.fwded_frames++;
540 return;
541
542fail:
543 rcu_read_unlock();
544 sdata->u.sta.mshstats.dropped_frames_no_route++;
545 return;
546}
547
548static void hwmp_perr_frame_process(struct net_device *dev,
549 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
550{
551 struct mesh_path *mpath;
552 u8 *ta, *dst_addr;
553 u32 dst_dsn;
554
555 ta = mgmt->sa;
556 dst_addr = PERR_IE_DST_ADDR(perr_elem);
557 dst_dsn = PERR_IE_DST_DSN(perr_elem);
558 rcu_read_lock();
559 mpath = mesh_path_lookup(dst_addr, dev);
560 if (mpath) {
561 spin_lock_bh(&mpath->state_lock);
562 if (mpath->flags & MESH_PATH_ACTIVE &&
563 memcmp(ta, mpath->next_hop->addr, ETH_ALEN) == 0 &&
564 (!(mpath->flags & MESH_PATH_DSN_VALID) ||
565 DSN_GT(dst_dsn, mpath->dsn))) {
566 mpath->flags &= ~MESH_PATH_ACTIVE;
567 mpath->dsn = dst_dsn;
568 spin_unlock_bh(&mpath->state_lock);
569 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn),
570 dev->broadcast, dev);
571 } else
572 spin_unlock_bh(&mpath->state_lock);
573 }
574 rcu_read_unlock();
575}
576
577
578
579void mesh_rx_path_sel_frame(struct net_device *dev,
580 struct ieee80211_mgmt *mgmt,
581 size_t len)
582{
583 struct ieee802_11_elems elems;
584 size_t baselen;
585 u32 last_hop_metric;
586
587 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
588 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
589 len - baselen, &elems);
590
591 switch (mgmt->u.action.u.mesh_action.action_code) {
592 case MPATH_PREQ:
593 if (!elems.preq || elems.preq_len != 37)
594 /* Right now we support just 1 destination and no AE */
595 return;
596 last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.preq);
597 if (!last_hop_metric)
598 return;
599 hwmp_preq_frame_process(dev, mgmt, elems.preq, last_hop_metric);
600 break;
601 case MPATH_PREP:
602 if (!elems.prep || elems.prep_len != 31)
603 /* Right now we support no AE */
604 return;
605 last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.prep);
606 if (!last_hop_metric)
607 return;
608 hwmp_prep_frame_process(dev, mgmt, elems.prep, last_hop_metric);
609 break;
610 case MPATH_PERR:
611 if (!elems.perr || elems.perr_len != 12)
612 /* Right now we support only one destination per PERR */
613 return;
614 hwmp_perr_frame_process(dev, mgmt, elems.perr);
615 default:
616 return;
617 }
618
619}
620
621/**
622 * mesh_queue_preq - queue a PREQ to a given destination
623 *
624 * @mpath: mesh path to discover
625 * @flags: special attributes of the PREQ to be sent
626 *
627 * Locking: the function must be called from within a rcu read lock block.
628 *
629 */
630static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
631{
632 struct ieee80211_sub_if_data *sdata =
633 IEEE80211_DEV_TO_SUB_IF(mpath->dev);
634 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
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(&ifsta->mesh_preq_queue_lock);
644 if (ifsta->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
645 spin_unlock(&ifsta->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, &ifsta->preq_queue.list);
656 ++ifsta->preq_queue_len;
657 spin_unlock(&ifsta->mesh_preq_queue_lock);
658
659 if (time_after(jiffies, ifsta->last_preq + min_preq_int_jiff(sdata)))
660 queue_work(sdata->local->hw.workqueue, &ifsta->work);
661
662 else if (time_before(jiffies, ifsta->last_preq)) {
663 /* avoid long wait if did not send preqs for a long time
664 * and jiffies wrapped around
665 */
666 ifsta->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
667 queue_work(sdata->local->hw.workqueue, &ifsta->work);
668 } else
669 mod_timer(&ifsta->mesh_path_timer, ifsta->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 * @dev: local mesh interface
677 */
678void mesh_path_start_discovery(struct net_device *dev)
679{
680 struct ieee80211_sub_if_data *sdata =
681 IEEE80211_DEV_TO_SUB_IF(dev);
682 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
683 struct mesh_preq_queue *preq_node;
684 struct mesh_path *mpath;
685 u8 ttl, dst_flags;
686 u32 lifetime;
687
688 spin_lock(&ifsta->mesh_preq_queue_lock);
689 if (!ifsta->preq_queue_len ||
690 time_before(jiffies, ifsta->last_preq +
691 min_preq_int_jiff(sdata))) {
692 spin_unlock(&ifsta->mesh_preq_queue_lock);
693 return;
694 }
695
696 preq_node = list_first_entry(&ifsta->preq_queue.list,
697 struct mesh_preq_queue, list);
698 list_del(&preq_node->list);
699 --ifsta->preq_queue_len;
700 spin_unlock(&ifsta->mesh_preq_queue_lock);
701
702 rcu_read_lock();
703 mpath = mesh_path_lookup(preq_node->dst, dev);
704 if (!mpath)
705 goto enddiscovery;
706
707 spin_lock_bh(&mpath->state_lock);
708 if (preq_node->flags & PREQ_Q_F_START) {
709 if (mpath->flags & MESH_PATH_RESOLVING) {
710 spin_unlock_bh(&mpath->state_lock);
711 goto enddiscovery;
712 } else {
713 mpath->flags &= ~MESH_PATH_RESOLVED;
714 mpath->flags |= MESH_PATH_RESOLVING;
715 mpath->discovery_retries = 0;
716 mpath->discovery_timeout = disc_timeout_jiff(sdata);
717 }
718 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
719 mpath->flags & MESH_PATH_RESOLVED) {
720 mpath->flags &= ~MESH_PATH_RESOLVING;
721 spin_unlock_bh(&mpath->state_lock);
722 goto enddiscovery;
723 }
724
725 ifsta->last_preq = jiffies;
726
727 if (time_after(jiffies, ifsta->last_dsn_update +
728 net_traversal_jiffies(sdata)) ||
729 time_before(jiffies, ifsta->last_dsn_update)) {
730 ++ifsta->dsn;
731 sdata->u.sta.last_dsn_update = jiffies;
732 }
733 lifetime = default_lifetime(sdata);
734 ttl = sdata->u.sta.mshcfg.dot11MeshTTL;
735 if (ttl == 0) {
736 sdata->u.sta.mshstats.dropped_frames_ttl++;
737 spin_unlock_bh(&mpath->state_lock);
738 goto enddiscovery;
739 }
740
741 if (preq_node->flags & PREQ_Q_F_REFRESH)
742 dst_flags = MP_F_DO;
743 else
744 dst_flags = MP_F_RF;
745
746 spin_unlock_bh(&mpath->state_lock);
747 mesh_path_sel_frame_tx(MPATH_PREQ, 0, dev->dev_addr,
748 cpu_to_le32(ifsta->dsn), dst_flags, mpath->dst,
749 cpu_to_le32(mpath->dsn), dev->broadcast, 0,
750 ttl, cpu_to_le32(lifetime), 0,
751 cpu_to_le32(ifsta->preq_id++), dev);
752 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
753
754enddiscovery:
755 rcu_read_unlock();
756 kfree(preq_node);
757}
758
759/**
760 * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame
761 *
762 * @next_hop: output argument for next hop address
763 * @skb: frame to be sent
764 * @dev: network device the frame will be sent through
765 *
766 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
767 * found, the function will start a path discovery and queue the frame so it is
768 * sent when the path is resolved. This means the caller must not free the skb
769 * in this case.
770 */
771int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb,
772 struct net_device *dev)
773{
774 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
775 struct sk_buff *skb_to_free = NULL;
776 struct mesh_path *mpath;
777 int err = 0;
778
779 rcu_read_lock();
780 mpath = mesh_path_lookup(skb->data, dev);
781
782 if (!mpath) {
783 mesh_path_add(skb->data, dev);
784 mpath = mesh_path_lookup(skb->data, dev);
785 if (!mpath) {
786 dev_kfree_skb(skb);
787 sdata->u.sta.mshstats.dropped_frames_no_route++;
788 err = -ENOSPC;
789 goto endlookup;
790 }
791 }
792
793 if (mpath->flags & MESH_PATH_ACTIVE) {
794 if (time_after(jiffies, mpath->exp_time -
795 msecs_to_jiffies(sdata->u.sta.mshcfg.path_refresh_time))
796 && skb->pkt_type != PACKET_OTHERHOST
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(next_hop, mpath->next_hop->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, dev);
819 err = -ENOENT;
820 }
821
822endlookup:
823 rcu_read_unlock();
824 return err;
825}
826
827void 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 = IEEE80211_DEV_TO_SUB_IF(mpath->dev);
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);
853endmpathtimer:
854 rcu_read_unlock();
855}
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-01 06:36:44 -0500