projects / linux-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
mac80211: code for on-demand Hybrid Wireless Mesh Protocol
[linux-block.git] / net / mac80211 / mesh_hwmp.c
CommitLineData
050ac52c
LCC		 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 IEEE80211_FC(type, stype) cpu_to_le16(type | stype)
13
14#define TEST_FRAME_LEN 8192
15#define MAX_METRIC 0xffffffff
16#define ARITH_SHIFT 8
17
18/* Number of frames buffered per destination for unresolved destinations */
19#define MESH_FRAME_QUEUE_LEN 10
20#define MAX_PREQ_QUEUE_LEN 64
21
22/* Destination only */
23#define MP_F_DO 0x1
24/* Reply and forward */
25#define MP_F_RF 0x2
26
27/* HWMP IE processing macros */
28#define AE_F (1<<6)
29#define AE_F_SET(x) (*x & AE_F)
30#define PREQ_IE_FLAGS(x) (*(x))
31#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
32#define PREQ_IE_TTL(x) (*(x + 2))
33#define PREQ_IE_PREQ_ID(x) le32_to_cpu(*((u32 *) (x + 3)))
34#define PREQ_IE_ORIG_ADDR(x) (x + 7)
35#define PREQ_IE_ORIG_DSN(x) le32_to_cpu(*((u32 *) (x + 13)))
36#define PREQ_IE_LIFETIME(x) le32_to_cpu(*((u32 *) \
37 (AE_F_SET(x) ? x + 23 : x + 17)))
38#define PREQ_IE_METRIC(x) le32_to_cpu(*((u32 *) \
39 (AE_F_SET(x) ? x + 27 : x + 21)))
40#define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
41#define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
42#define PREQ_IE_DST_DSN(x) le32_to_cpu(*((u32 *) \
43 (AE_F_SET(x) ? x + 39 : x + 33)))
44
45
46#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
47#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
48#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
49#define PREP_IE_ORIG_ADDR(x) (x + 3)
50#define PREP_IE_ORIG_DSN(x) le32_to_cpu(*((u32 *) (x + 9)))
51#define PREP_IE_LIFETIME(x) le32_to_cpu(*((u32 *) \
52 (AE_F_SET(x) ? x + 19 : x + 13)))
53#define PREP_IE_METRIC(x) le32_to_cpu(*((u32 *) \
54 (AE_F_SET(x) ? x + 23 : x + 17)))
55#define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
56#define PREP_IE_DST_DSN(x) le32_to_cpu(*((u32 *) \
57 (AE_F_SET(x) ? x + 33 : x + 27)))
58
59#define PERR_IE_DST_ADDR(x) (x + 2)
60#define PERR_IE_DST_DSN(x) le32_to_cpu(*((u32 *) (x + 8)))
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 return 0;
269
270 last_hop_metric = airtime_link_metric_get(local, sta);
271 /* Update and check originator routing info */
272 fresh_info = true;
273
274 switch (action) {
275 case MPATH_PREQ:
276 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
277 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
278 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
279 orig_metric = PREQ_IE_METRIC(hwmp_ie);
280 break;
281 case MPATH_PREP:
282 /* Originator here refers to the MP that was the destination in
283 * the Path Request. The draft refers to that MP as the
284 * destination address, even though usually it is the origin of
285 * the PREP frame. We divert from the nomenclature in the draft
286 * so that we can easily use a single function to gather path
287 * information from both PREQ and PREP frames.
288 */
289 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
290 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
291 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
292 orig_metric = PREP_IE_METRIC(hwmp_ie);
293 break;
294 default:
295 sta_info_put(sta);
296 return 0;
297 }
298 new_metric = orig_metric + last_hop_metric;
299 if (new_metric < orig_metric)
300 new_metric = MAX_METRIC;
301 exp_time = TU_TO_EXP_TIME(orig_lifetime);
302
303 if (memcmp(orig_addr, dev->dev_addr, ETH_ALEN) == 0) {
304 /* This MP is the originator, we are not interested in this
305 * frame, except for updating transmitter's path info.
306 */
307 process = false;
308 fresh_info = false;
309 } else {
310 mpath = mesh_path_lookup(orig_addr, dev);
311 if (mpath) {
312 spin_lock_bh(&mpath->state_lock);
313 if (mpath->flags & MESH_PATH_FIXED)
314 fresh_info = false;
315 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
316 (mpath->flags & MESH_PATH_DSN_VALID)) {
317 if (DSN_GT(mpath->dsn, orig_dsn) ||
318 (mpath->dsn == orig_dsn &&
319 action == MPATH_PREQ &&
320 new_metric > mpath->metric)) {
321 process = false;
322 fresh_info = false;
323 }
324 }
325 } else {
326 mesh_path_add(orig_addr, dev);
327 mpath = mesh_path_lookup(orig_addr, dev);
328 if (!mpath) {
329 rcu_read_unlock();
330 sta_info_put(sta);
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, dev);
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, dev);
369 mpath = mesh_path_lookup(ta, dev);
370 if (!mpath) {
371 rcu_read_unlock();
372 sta_info_put(sta);
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 sta_info_put(sta);
392 rcu_read_unlock();
393
394 return process ? new_metric : 0;
395}
396
397static void hwmp_preq_frame_process(struct net_device *dev,
398 struct ieee80211_mgmt *mgmt,
399 u8 *preq_elem, u32 metric) {
400 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
401 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
402 struct mesh_path *mpath;
403 u8 *dst_addr, *orig_addr;
404 u8 dst_flags, ttl;
405 u32 orig_dsn, dst_dsn, lifetime;
406 bool reply = false;
407 bool forward = true;
408
409 /* Update destination DSN, if present */
410 dst_addr = PREQ_IE_DST_ADDR(preq_elem);
411 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
412 dst_dsn = PREQ_IE_DST_DSN(preq_elem);
413 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem);
414 dst_flags = PREQ_IE_DST_F(preq_elem);
415
416 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0) {
417 forward = false;
418 reply = true;
419 metric = 0;
420 if (time_after(jiffies, ifsta->last_dsn_update +
421 net_traversal_jiffies(sdata)) ||
422 time_before(jiffies, ifsta->last_dsn_update)) {
423 dst_dsn = ++ifsta->dsn;
424 ifsta->last_dsn_update = jiffies;
425 }
426 } else {
427 rcu_read_lock();
428 mpath = mesh_path_lookup(dst_addr, dev);
429 if (mpath) {
430 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) ||
431 DSN_LT(mpath->dsn, dst_dsn)) {
432 mpath->dsn = dst_dsn;
433 mpath->flags &= MESH_PATH_DSN_VALID;
434 } else if ((!(dst_flags & MP_F_DO)) &&
435 (mpath->flags & MESH_PATH_ACTIVE)) {
436 reply = true;
437 metric = mpath->metric;
438 dst_dsn = mpath->dsn;
439 if (dst_flags & MP_F_RF)
440 dst_flags |= MP_F_DO;
441 else
442 forward = false;
443 }
444 }
445 rcu_read_unlock();
446 }
447
448 if (reply) {
449 lifetime = PREQ_IE_LIFETIME(preq_elem);
450 ttl = ifsta->mshcfg.dot11MeshTTL;
451 if (ttl != 0)
452 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr,
453 __cpu_to_le32(dst_dsn), 0, orig_addr,
454 __cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl,
455 __cpu_to_le32(lifetime), __cpu_to_le32(metric),
456 0, dev);
457 else
458 ifsta->mshstats.dropped_frames_ttl++;
459 }
460
461 if (forward) {
462 u32 preq_id;
463 u8 hopcount, flags;
464
465 ttl = PREQ_IE_TTL(preq_elem);
466 lifetime = PREQ_IE_LIFETIME(preq_elem);
467 if (ttl <= 1) {
468 ifsta->mshstats.dropped_frames_ttl++;
469 return;
470 }
471 --ttl;
472 flags = PREQ_IE_FLAGS(preq_elem);
473 preq_id = PREQ_IE_PREQ_ID(preq_elem);
474 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
475 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
476 __cpu_to_le32(orig_dsn), dst_flags, dst_addr,
477 __cpu_to_le32(dst_dsn), dev->broadcast,
478 hopcount, ttl, __cpu_to_le32(lifetime),
479 __cpu_to_le32(metric), __cpu_to_le32(preq_id),
480 dev);
481 ifsta->mshstats.fwded_frames++;
482 }
483}
484
485
486static void hwmp_prep_frame_process(struct net_device *dev,
487 struct ieee80211_mgmt *mgmt,
488 u8 *prep_elem, u32 metric)
489{
490 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
491 struct mesh_path *mpath;
492 u8 *dst_addr, *orig_addr;
493 u8 ttl, hopcount, flags;
494 u8 next_hop[ETH_ALEN];
495 u32 dst_dsn, orig_dsn, lifetime;
496
497 /* Note that we divert from the draft nomenclature and denominate
498 * destination to what the draft refers to as origininator. So in this
499 * function destnation refers to the final destination of the PREP,
500 * which corresponds with the originator of the PREQ which this PREP
501 * replies
502 */
503 dst_addr = PREP_IE_DST_ADDR(prep_elem);
504 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0)
505 /* destination, no forwarding required */
506 return;
507
508 ttl = PREP_IE_TTL(prep_elem);
509 if (ttl <= 1) {
510 sdata->u.sta.mshstats.dropped_frames_ttl++;
511 return;
512 }
513
514 rcu_read_lock();
515 mpath = mesh_path_lookup(dst_addr, dev);
516 if (mpath)
517 spin_lock_bh(&mpath->state_lock);
518 else
519 goto fail;
520 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
521 spin_unlock_bh(&mpath->state_lock);
522 goto fail;
523 }
524 memcpy(next_hop, mpath->next_hop->addr, ETH_ALEN);
525 spin_unlock_bh(&mpath->state_lock);
526 --ttl;
527 flags = PREP_IE_FLAGS(prep_elem);
528 lifetime = PREP_IE_LIFETIME(prep_elem);
529 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
530 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
531 dst_dsn = PREP_IE_DST_DSN(prep_elem);
532 orig_dsn = PREP_IE_ORIG_DSN(prep_elem);
533
534 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
535 __cpu_to_le32(orig_dsn), 0, dst_addr,
536 __cpu_to_le32(dst_dsn), mpath->next_hop->addr, hopcount, ttl,
537 __cpu_to_le32(lifetime), __cpu_to_le32(metric),
538 0, dev);
539 rcu_read_unlock();
540 sdata->u.sta.mshstats.fwded_frames++;
541 return;
542
543fail:
544 rcu_read_unlock();
545 sdata->u.sta.mshstats.dropped_frames_no_route++;
546 return;
547}
548
549static void hwmp_perr_frame_process(struct net_device *dev,
550 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
551{
552 struct mesh_path *mpath;
553 u8 *ta, *dst_addr;
554 u32 dst_dsn;
555
556 ta = mgmt->sa;
557 dst_addr = PERR_IE_DST_ADDR(perr_elem);
558 dst_dsn = PERR_IE_DST_DSN(perr_elem);
559 rcu_read_lock();
560 mpath = mesh_path_lookup(dst_addr, dev);
561 if (mpath) {
562 spin_lock_bh(&mpath->state_lock);
563 if (mpath->flags & MESH_PATH_ACTIVE &&
564 memcmp(ta, mpath->next_hop->addr, ETH_ALEN) == 0 &&
565 (!(mpath->flags & MESH_PATH_DSN_VALID) ||
566 DSN_GT(dst_dsn, mpath->dsn))) {
567 mpath->flags &= ~MESH_PATH_ACTIVE;
568 mpath->dsn = dst_dsn;
569 spin_unlock_bh(&mpath->state_lock);
570 mesh_path_error_tx(dst_addr, dst_dsn, dev->broadcast,
571 dev);
572 } else
573 spin_unlock_bh(&mpath->state_lock);
574 }
575 rcu_read_unlock();
576}
577
578
579
580void mesh_rx_path_sel_frame(struct net_device *dev,
581 struct ieee80211_mgmt *mgmt,
582 size_t len)
583{
584 struct ieee802_11_elems elems;
585 size_t baselen;
586 u32 last_hop_metric;
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(dev, mgmt, elems.preq);
598 if (!last_hop_metric)
599 return;
600 hwmp_preq_frame_process(dev, 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(dev, mgmt, elems.prep);
607 if (!last_hop_metric)
608 return;
609 hwmp_prep_frame_process(dev, 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(dev, 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 */
631static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
632{
633 struct ieee80211_sub_if_data *sdata =
634 IEEE80211_DEV_TO_SUB_IF(mpath->dev);
635 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
636 struct mesh_preq_queue *preq_node;
637
638 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL);
639 if (!preq_node) {
640 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n");
641 return;
642 }
643
644 spin_lock(&ifsta->mesh_preq_queue_lock);
645 if (ifsta->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
646 spin_unlock(&ifsta->mesh_preq_queue_lock);
647 kfree(preq_node);
648 if (printk_ratelimit())
649 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n");
650 return;
651 }
652
653 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
654 preq_node->flags = flags;
655
656 list_add_tail(&preq_node->list, &ifsta->preq_queue.list);
657 ++ifsta->preq_queue_len;
658 spin_unlock(&ifsta->mesh_preq_queue_lock);
659
660 if (time_after(jiffies, ifsta->last_preq + min_preq_int_jiff(sdata)))
661 queue_work(sdata->local->hw.workqueue, &ifsta->work);
662
663 else if (time_before(jiffies, ifsta->last_preq)) {
664 /* avoid long wait if did not send preqs for a long time
665 * and jiffies wrapped around
666 */
667 ifsta->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
668 queue_work(sdata->local->hw.workqueue, &ifsta->work);
669 } else
670 mod_timer(&ifsta->mesh_path_timer, ifsta->last_preq +
671 min_preq_int_jiff(sdata));
672}
673
674/**
675 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
676 *
677 * @dev: local mesh interface
678 */
679void mesh_path_start_discovery(struct net_device *dev)
680{
681 struct ieee80211_sub_if_data *sdata =
682 IEEE80211_DEV_TO_SUB_IF(dev);
683 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
684 struct mesh_preq_queue *preq_node;
685 struct mesh_path *mpath;
686 u8 ttl, dst_flags;
687 u32 lifetime;
688
689 spin_lock(&ifsta->mesh_preq_queue_lock);
690 if (!ifsta->preq_queue_len ||
691 time_before(jiffies, ifsta->last_preq +
692 min_preq_int_jiff(sdata))) {
693 spin_unlock(&ifsta->mesh_preq_queue_lock);
694 return;
695 }
696
697 preq_node = list_first_entry(&ifsta->preq_queue.list,
698 struct mesh_preq_queue, list);
699 list_del(&preq_node->list);
700 --ifsta->preq_queue_len;
701 spin_unlock(&ifsta->mesh_preq_queue_lock);
702
703 rcu_read_lock();
704 mpath = mesh_path_lookup(preq_node->dst, dev);
705 if (!mpath)
706 goto enddiscovery;
707
708 spin_lock_bh(&mpath->state_lock);
709 if (preq_node->flags & PREQ_Q_F_START) {
710 if (mpath->flags & MESH_PATH_RESOLVING) {
711 spin_unlock_bh(&mpath->state_lock);
712 goto enddiscovery;
713 } else {
714 mpath->flags &= ~MESH_PATH_RESOLVED;
715 mpath->flags |= MESH_PATH_RESOLVING;
716 mpath->discovery_retries = 0;
717 mpath->discovery_timeout = disc_timeout_jiff(sdata);
718 }
719 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
720 mpath->flags & MESH_PATH_RESOLVED) {
721 mpath->flags &= ~MESH_PATH_RESOLVING;
722 spin_unlock_bh(&mpath->state_lock);
723 goto enddiscovery;
724 }
725
726 ifsta->last_preq = jiffies;
727
728 if (time_after(jiffies, ifsta->last_dsn_update +
729 net_traversal_jiffies(sdata)) ||
730 time_before(jiffies, ifsta->last_dsn_update)) {
731 ++ifsta->dsn;
732 sdata->u.sta.last_dsn_update = jiffies;
733 }
734 lifetime = default_lifetime(sdata);
735 ttl = sdata->u.sta.mshcfg.dot11MeshTTL;
736 if (ttl == 0) {
737 sdata->u.sta.mshstats.dropped_frames_ttl++;
738 spin_unlock_bh(&mpath->state_lock);
739 goto enddiscovery;
740 }
741
742 if (preq_node->flags & PREQ_Q_F_REFRESH)
743 dst_flags = MP_F_DO;
744 else
745 dst_flags = MP_F_RF;
746
747 spin_unlock_bh(&mpath->state_lock);
748 mesh_path_sel_frame_tx(MPATH_PREQ, 0, dev->dev_addr,
749 __cpu_to_le32(ifsta->dsn), dst_flags, mpath->dst,
750 __cpu_to_le32(mpath->dsn), dev->broadcast, 0,
751 ttl, __cpu_to_le32(lifetime), 0,
752 __cpu_to_le32(ifsta->preq_id++), dev);
753 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
754
755enddiscovery:
756 rcu_read_unlock();
757 kfree(preq_node);
758}
759
760/**
761 * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame
762 *
763 * @next_hop: output argument for next hop address
764 * @skb: frame to be sent
765 * @dev: network device the frame will be sent through
766 *
767 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
768 * found, the function will start a path discovery and queue the frame so it is
769 * sent when the path is resolved. This means the caller must not free the skb
770 * in this case.
771 */
772int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb,
773 struct net_device *dev)
774{
775 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
776 struct sk_buff *skb_to_free = NULL;
777 struct mesh_path *mpath;
778 int err = 0;
779
780 rcu_read_lock();
781 mpath = mesh_path_lookup(skb->data, dev);
782
783 if (!mpath) {
784 mesh_path_add(skb->data, dev);
785 mpath = mesh_path_lookup(skb->data, dev);
786 if (!mpath) {
787 dev_kfree_skb(skb);
788 sdata->u.sta.mshstats.dropped_frames_no_route++;
789 err = -ENOSPC;
790 goto endlookup;
791 }
792 }
793
794 if (mpath->flags & MESH_PATH_ACTIVE) {
795 if (time_after(jiffies, mpath->exp_time -
796 msecs_to_jiffies(sdata->u.sta.mshcfg.path_refresh_time))
797 && skb->pkt_type != PACKET_OTHERHOST
798 && !(mpath->flags & MESH_PATH_RESOLVING)
799 && !(mpath->flags & MESH_PATH_FIXED)) {
800 mesh_queue_preq(mpath,
801 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
802 }
803 memcpy(next_hop, mpath->next_hop->addr,
804 ETH_ALEN);
805 } else {
806 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
807 /* Start discovery only if it is not running yet */
808 mesh_queue_preq(mpath, PREQ_Q_F_START);
809 }
810
811 if (skb_queue_len(&mpath->frame_queue) >=
812 MESH_FRAME_QUEUE_LEN) {
813 skb_to_free = mpath->frame_queue.next;
814 skb_unlink(skb_to_free, &mpath->frame_queue);
815 }
816
817 skb_queue_tail(&mpath->frame_queue, skb);
818 if (skb_to_free)
819 mesh_path_discard_frame(skb_to_free, dev);
820 err = -ENOENT;
821 }
822
823endlookup:
824 rcu_read_unlock();
825 return err;
826}
827
828void mesh_path_timer(unsigned long data)
829{
830 struct ieee80211_sub_if_data *sdata;
831 struct mesh_path *mpath;
832 bool delete = false;
833
834 rcu_read_lock();
835 mpath = (struct mesh_path *) data;
836 mpath = rcu_dereference(mpath);
837 if (!mpath)
838 goto endmpathtimer;
839 spin_lock_bh(&mpath->state_lock);
840 sdata = IEEE80211_DEV_TO_SUB_IF(mpath->dev);
841 if (mpath->flags & MESH_PATH_DELETE) {
842 mpath->flags = 0;
843 delete = true;
844 } else if (mpath->flags & MESH_PATH_RESOLVED ||
845 (!(mpath->flags & MESH_PATH_RESOLVING)))
846 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
847 else if (mpath->discovery_retries < max_preq_retries(sdata)) {
848 ++mpath->discovery_retries;
849 mpath->discovery_timeout *= 2;
850 mesh_queue_preq(mpath, 0);
851 } else {
852 mpath->flags = 0;
853 mpath->exp_time = jiffies;
854 mesh_path_flush_pending(mpath);
855 }
856
857 spin_unlock_bh(&mpath->state_lock);
858endmpathtimer:
859 rcu_read_unlock();
860 if (delete)
861 mesh_path_del(mpath->dst, mpath->dev);
862}
Linux 6.x block layer and io_uring tree(s)