aboutsummaryrefslogtreecommitdiffstats
path: root/net/mac80211/mesh_hwmp.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/mac80211/mesh_hwmp.c')
-rw-r--r--net/mac80211/mesh_hwmp.c857
1 files changed, 857 insertions, 0 deletions
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
new file mode 100644
index 000000000000..576a6e55323e
--- /dev/null
+++ b/net/mac80211/mesh_hwmp.c
@@ -0,0 +1,857 @@
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 IEEE80211_FC(type, stype) cpu_to_le16(type | stype)
14
15#define TEST_FRAME_LEN 8192
16#define MAX_METRIC 0xffffffff
17#define ARITH_SHIFT 8
18
19/* Number of frames buffered per destination for unresolved destinations */
20#define MESH_FRAME_QUEUE_LEN 10
21#define MAX_PREQ_QUEUE_LEN 64
22
23/* Destination only */
24#define MP_F_DO 0x1
25/* Reply and forward */
26#define MP_F_RF 0x2
27
28static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
29{
30 if (ae)
31 offset += 6;
32 return le32_to_cpu(get_unaligned((__le32 *) (preq_elem + offset)));
33}
34
35/* HWMP IE processing macros */
36#define AE_F (1<<6)
37#define AE_F_SET(x) (*x & AE_F)
38#define PREQ_IE_FLAGS(x) (*(x))
39#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
40#define PREQ_IE_TTL(x) (*(x + 2))
41#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
42#define PREQ_IE_ORIG_ADDR(x) (x + 7)
43#define PREQ_IE_ORIG_DSN(x) u32_field_get(x, 13, 0);
44#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x));
45#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x));
46#define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
47#define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
48#define PREQ_IE_DST_DSN(x) u32_field_get(x, 33, AE_F_SET(x));
49
50
51#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
52#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
53#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
54#define PREP_IE_ORIG_ADDR(x) (x + 3)
55#define PREP_IE_ORIG_DSN(x) u32_field_get(x, 9, 0);
56#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x));
57#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x));
58#define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
59#define PREP_IE_DST_DSN(x) u32_field_get(x, 27, AE_F_SET(x));
60
61#define PERR_IE_DST_ADDR(x) (x + 2)
62#define PERR_IE_DST_DSN(x) u32_field_get(x, 8, 0);
63
64#define TU_TO_EXP_TIME(x) (jiffies + msecs_to_jiffies(x * 1024 / 1000))
65#define MSEC_TO_TU(x) (x*1000/1024)
66#define DSN_GT(x, y) ((long) (y) - (long) (x) < 0)
67#define DSN_LT(x, y) ((long) (x) - (long) (y) < 0)
68
69#define net_traversal_jiffies(s) \
70 msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
71#define default_lifetime(s) \
72 MSEC_TO_TU(s->u.sta.mshcfg.dot11MeshHWMPactivePathTimeout)
73#define min_preq_int_jiff(s) \
74 (msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPpreqMinInterval))
75#define max_preq_retries(s) (s->u.sta.mshcfg.dot11MeshHWMPmaxPREQretries)
76#define disc_timeout_jiff(s) \
77 msecs_to_jiffies(sdata->u.sta.mshcfg.min_discovery_timeout)
78
79enum mpath_frame_type {
80 MPATH_PREQ = 0,
81 MPATH_PREP,
82 MPATH_PERR
83};
84
85static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
86 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst,
87 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime,
88 __le32 metric, __le32 preq_id, struct net_device *dev)
89{
90 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
91 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
92 struct ieee80211_mgmt *mgmt;
93 u8 *pos;
94 int ie_len;
95
96 if (!skb)
97 return -1;
98 skb_reserve(skb, local->hw.extra_tx_headroom);
99 /* 25 is the size of the common mgmt part (24) plus the size of the
100 * common action part (1)
101 */
102 mgmt = (struct ieee80211_mgmt *)
103 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
104 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
105 mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
106 IEEE80211_STYPE_ACTION);
107
108 memcpy(mgmt->da, da, ETH_ALEN);
109 memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
110 /* BSSID is left zeroed, wildcard value */
111 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
112 mgmt->u.action.u.mesh_action.action_code = action;
113
114 switch (action) {
115 case MPATH_PREQ:
116 ie_len = 37;
117 pos = skb_put(skb, 2 + ie_len);
118 *pos++ = WLAN_EID_PREQ;
119 break;
120 case MPATH_PREP:
121 ie_len = 31;
122 pos = skb_put(skb, 2 + ie_len);
123 *pos++ = WLAN_EID_PREP;
124 break;
125 default:
126 kfree(skb);
127 return -ENOTSUPP;
128 break;
129 }
130 *pos++ = ie_len;
131 *pos++ = flags;
132 *pos++ = hop_count;
133 *pos++ = ttl;
134 if (action == MPATH_PREQ) {
135 memcpy(pos, &preq_id, 4);
136 pos += 4;
137 }
138 memcpy(pos, orig_addr, ETH_ALEN);
139 pos += ETH_ALEN;
140 memcpy(pos, &orig_dsn, 4);
141 pos += 4;
142 memcpy(pos, &lifetime, 4);
143 pos += 4;
144 memcpy(pos, &metric, 4);
145 pos += 4;
146 if (action == MPATH_PREQ) {
147 /* destination count */
148 *pos++ = 1;
149 *pos++ = dst_flags;
150 }
151 memcpy(pos, dst, ETH_ALEN);
152 pos += ETH_ALEN;
153 memcpy(pos, &dst_dsn, 4);
154
155 ieee80211_sta_tx(dev, skb, 0);
156 return 0;
157}
158
159/**
160 * mesh_send_path error - Sends a PERR mesh management frame
161 *
162 * @dst: broken destination
163 * @dst_dsn: dsn of the broken destination
164 * @ra: node this frame is addressed to
165 */
166int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
167 struct net_device *dev)
168{
169 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
170 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
171 struct ieee80211_mgmt *mgmt;
172 u8 *pos;
173 int ie_len;
174
175 if (!skb)
176 return -1;
177 skb_reserve(skb, local->hw.extra_tx_headroom);
178 /* 25 is the size of the common mgmt part (24) plus the size of the
179 * common action part (1)
180 */
181 mgmt = (struct ieee80211_mgmt *)
182 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
183 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
184 mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
185 IEEE80211_STYPE_ACTION);
186
187 memcpy(mgmt->da, ra, ETH_ALEN);
188 memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
189 /* BSSID is left zeroed, wildcard value */
190 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
191 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR;
192 ie_len = 12;
193 pos = skb_put(skb, 2 + ie_len);
194 *pos++ = WLAN_EID_PERR;
195 *pos++ = ie_len;
196 /* mode flags, reserved */
197 *pos++ = 0;
198 /* number of destinations */
199 *pos++ = 1;
200 memcpy(pos, dst, ETH_ALEN);
201 pos += ETH_ALEN;
202 memcpy(pos, &dst_dsn, 4);
203
204 ieee80211_sta_tx(dev, skb, 0);
205 return 0;
206}
207
208static u32 airtime_link_metric_get(struct ieee80211_local *local,
209 struct sta_info *sta)
210{
211 struct ieee80211_supported_band *sband;
212 /* This should be adjusted for each device */
213 int device_constant = 1 << ARITH_SHIFT;
214 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
215 int s_unit = 1 << ARITH_SHIFT;
216 int rate, err;
217 u32 tx_time, estimated_retx;
218 u64 result;
219
220 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
221
222 if (sta->fail_avg >= 100)
223 return MAX_METRIC;
224 err = (sta->fail_avg << ARITH_SHIFT) / 100;
225
226 /* bitrate is in units of 100 Kbps, while we need rate in units of
227 * 1Mbps. This will be corrected on tx_time computation.
228 */
229 rate = sband->bitrates[sta->txrate_idx].bitrate;
230 tx_time = (device_constant + 10 * test_frame_len / rate);
231 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
232 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
233 return (u32)result;
234}
235
236/**
237 * hwmp_route_info_get - Update routing info to originator and transmitter
238 *
239 * @dev: local mesh interface
240 * @mgmt: mesh management frame
241 * @hwmp_ie: hwmp information element (PREP or PREQ)
242 *
243 * This function updates the path routing information to the originator and the
244 * transmitter of a HWMP PREQ or PREP fram.
245 *
246 * Returns: metric to frame originator or 0 if the frame should not be further
247 * processed
248 *
249 * Notes: this function is the only place (besides user-provided info) where
250 * path routing information is updated.
251 */
252static u32 hwmp_route_info_get(struct net_device *dev,
253 struct ieee80211_mgmt *mgmt,
254 u8 *hwmp_ie)
255{
256 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
257 struct mesh_path *mpath;
258 struct sta_info *sta;
259 bool fresh_info;
260 u8 *orig_addr, *ta;
261 u32 orig_dsn, orig_metric;
262 unsigned long orig_lifetime, exp_time;
263 u32 last_hop_metric, new_metric;
264 bool process = true;
265 u8 action = mgmt->u.action.u.mesh_action.action_code;
266
267 rcu_read_lock();
268 sta = sta_info_get(local, mgmt->sa);
269 if (!sta) {
270 rcu_read_unlock();
271 return 0;
272 }
273
274 last_hop_metric = airtime_link_metric_get(local, sta);
275 /* Update and check originator routing info */
276 fresh_info = true;
277
278 switch (action) {
279 case MPATH_PREQ:
280 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
281 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
282 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
283 orig_metric = PREQ_IE_METRIC(hwmp_ie);
284 break;
285 case MPATH_PREP:
286 /* Originator here refers to the MP that was the destination in
287 * the Path Request. The draft refers to that MP as the
288 * destination address, even though usually it is the origin of
289 * the PREP frame. We divert from the nomenclature in the draft
290 * so that we can easily use a single function to gather path
291 * information from both PREQ and PREP frames.
292 */
293 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
294 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
295 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
296 orig_metric = PREP_IE_METRIC(hwmp_ie);
297 break;
298 default:
299 rcu_read_unlock();
300 return 0;
301 }
302 new_metric = orig_metric + last_hop_metric;
303 if (new_metric < orig_metric)
304 new_metric = MAX_METRIC;
305 exp_time = TU_TO_EXP_TIME(orig_lifetime);
306
307 if (memcmp(orig_addr, dev->dev_addr, ETH_ALEN) == 0) {
308 /* This MP is the originator, we are not interested in this
309 * frame, except for updating transmitter's path info.
310 */
311 process = false;
312 fresh_info = false;
313 } else {
314 mpath = mesh_path_lookup(orig_addr, dev);
315 if (mpath) {
316 spin_lock_bh(&mpath->state_lock);
317 if (mpath->flags & MESH_PATH_FIXED)
318 fresh_info = false;
319 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
320 (mpath->flags & MESH_PATH_DSN_VALID)) {
321 if (DSN_GT(mpath->dsn, orig_dsn) ||
322 (mpath->dsn == orig_dsn &&
323 action == MPATH_PREQ &&
324 new_metric > mpath->metric)) {
325 process = false;
326 fresh_info = false;
327 }
328 }
329 } else {
330 mesh_path_add(orig_addr, dev);
331 mpath = mesh_path_lookup(orig_addr, dev);
332 if (!mpath) {
333 rcu_read_unlock();
334 return 0;
335 }
336 spin_lock_bh(&mpath->state_lock);
337 }
338
339 if (fresh_info) {
340 mesh_path_assign_nexthop(mpath, sta);
341 mpath->flags |= MESH_PATH_DSN_VALID;
342 mpath->metric = new_metric;
343 mpath->dsn = orig_dsn;
344 mpath->exp_time = time_after(mpath->exp_time, exp_time)
345 ? mpath->exp_time : exp_time;
346 mesh_path_activate(mpath);
347 spin_unlock_bh(&mpath->state_lock);
348 mesh_path_tx_pending(mpath);
349 /* draft says preq_id should be saved to, but there does
350 * not seem to be any use for it, skipping by now
351 */
352 } else
353 spin_unlock_bh(&mpath->state_lock);
354 }
355
356 /* Update and check transmitter routing info */
357 ta = mgmt->sa;
358 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
359 fresh_info = false;
360 else {
361 fresh_info = true;
362
363 mpath = mesh_path_lookup(ta, dev);
364 if (mpath) {
365 spin_lock_bh(&mpath->state_lock);
366 if ((mpath->flags & MESH_PATH_FIXED) ||
367 ((mpath->flags & MESH_PATH_ACTIVE) &&
368 (last_hop_metric > mpath->metric)))
369 fresh_info = false;
370 } else {
371 mesh_path_add(ta, dev);
372 mpath = mesh_path_lookup(ta, dev);
373 if (!mpath) {
374 rcu_read_unlock();
375 return 0;
376 }
377 spin_lock_bh(&mpath->state_lock);
378 }
379
380 if (fresh_info) {
381 mesh_path_assign_nexthop(mpath, sta);
382 mpath->flags &= ~MESH_PATH_DSN_VALID;
383 mpath->metric = last_hop_metric;
384 mpath->exp_time = time_after(mpath->exp_time, exp_time)
385 ? mpath->exp_time : exp_time;
386 mesh_path_activate(mpath);
387 spin_unlock_bh(&mpath->state_lock);
388 mesh_path_tx_pending(mpath);
389 } else
390 spin_unlock_bh(&mpath->state_lock);
391 }
392
393 rcu_read_unlock();
394
395 return process ? new_metric : 0;
396}
397
398static void hwmp_preq_frame_process(struct net_device *dev,
399 struct ieee80211_mgmt *mgmt,
400 u8 *preq_elem, u32 metric) {
401 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
402 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
403 struct mesh_path *mpath;
404 u8 *dst_addr, *orig_addr;
405 u8 dst_flags, ttl;
406 u32 orig_dsn, dst_dsn, lifetime;
407 bool reply = false;
408 bool forward = true;
409
410 /* Update destination DSN, if present */
411 dst_addr = PREQ_IE_DST_ADDR(preq_elem);
412 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
413 dst_dsn = PREQ_IE_DST_DSN(preq_elem);
414 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem);
415 dst_flags = PREQ_IE_DST_F(preq_elem);
416
417 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0) {
418 forward = false;
419 reply = true;
420 metric = 0;
421 if (time_after(jiffies, ifsta->last_dsn_update +
422 net_traversal_jiffies(sdata)) ||
423 time_before(jiffies, ifsta->last_dsn_update)) {
424 dst_dsn = ++ifsta->dsn;
425 ifsta->last_dsn_update = jiffies;
426 }
427 } else {
428 rcu_read_lock();
429 mpath = mesh_path_lookup(dst_addr, dev);
430 if (mpath) {
431 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) ||
432 DSN_LT(mpath->dsn, dst_dsn)) {
433 mpath->dsn = dst_dsn;
434 mpath->flags &= MESH_PATH_DSN_VALID;
435 } else if ((!(dst_flags & MP_F_DO)) &&
436 (mpath->flags & MESH_PATH_ACTIVE)) {
437 reply = true;
438 metric = mpath->metric;
439 dst_dsn = mpath->dsn;
440 if (dst_flags & MP_F_RF)
441 dst_flags |= MP_F_DO;
442 else
443 forward = false;
444 }
445 }
446 rcu_read_unlock();
447 }
448
449 if (reply) {
450 lifetime = PREQ_IE_LIFETIME(preq_elem);
451 ttl = ifsta->mshcfg.dot11MeshTTL;
452 if (ttl != 0)
453 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr,
454 cpu_to_le32(dst_dsn), 0, orig_addr,
455 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl,
456 cpu_to_le32(lifetime), cpu_to_le32(metric),
457 0, dev);
458 else
459 ifsta->mshstats.dropped_frames_ttl++;
460 }
461
462 if (forward) {
463 u32 preq_id;
464 u8 hopcount, flags;
465
466 ttl = PREQ_IE_TTL(preq_elem);
467 lifetime = PREQ_IE_LIFETIME(preq_elem);
468 if (ttl <= 1) {
469 ifsta->mshstats.dropped_frames_ttl++;
470 return;
471 }
472 --ttl;
473 flags = PREQ_IE_FLAGS(preq_elem);
474 preq_id = PREQ_IE_PREQ_ID(preq_elem);
475 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
476 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
477 cpu_to_le32(orig_dsn), dst_flags, dst_addr,
478 cpu_to_le32(dst_dsn), dev->broadcast,
479 hopcount, ttl, cpu_to_le32(lifetime),
480 cpu_to_le32(metric), cpu_to_le32(preq_id),
481 dev);
482 ifsta->mshstats.fwded_frames++;
483 }
484}
485
486
487static void hwmp_prep_frame_process(struct net_device *dev,
488 struct ieee80211_mgmt *mgmt,
489 u8 *prep_elem, u32 metric)
490{
491 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
492 struct mesh_path *mpath;
493 u8 *dst_addr, *orig_addr;
494 u8 ttl, hopcount, flags;
495 u8 next_hop[ETH_ALEN];
496 u32 dst_dsn, orig_dsn, lifetime;
497
498 /* Note that we divert from the draft nomenclature and denominate
499 * destination to what the draft refers to as origininator. So in this
500 * function destnation refers to the final destination of the PREP,
501 * which corresponds with the originator of the PREQ which this PREP
502 * replies
503 */
504 dst_addr = PREP_IE_DST_ADDR(prep_elem);
505 if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0)
506 /* destination, no forwarding required */
507 return;
508
509 ttl = PREP_IE_TTL(prep_elem);
510 if (ttl <= 1) {
511 sdata->u.sta.mshstats.dropped_frames_ttl++;
512 return;
513 }
514
515 rcu_read_lock();
516 mpath = mesh_path_lookup(dst_addr, dev);
517 if (mpath)
518 spin_lock_bh(&mpath->state_lock);
519 else
520 goto fail;
521 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
522 spin_unlock_bh(&mpath->state_lock);
523 goto fail;
524 }
525 memcpy(next_hop, mpath->next_hop->addr, ETH_ALEN);
526 spin_unlock_bh(&mpath->state_lock);
527 --ttl;
528 flags = PREP_IE_FLAGS(prep_elem);
529 lifetime = PREP_IE_LIFETIME(prep_elem);
530 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
531 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
532 dst_dsn = PREP_IE_DST_DSN(prep_elem);
533 orig_dsn = PREP_IE_ORIG_DSN(prep_elem);
534
535 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
536 cpu_to_le32(orig_dsn), 0, dst_addr,
537 cpu_to_le32(dst_dsn), mpath->next_hop->addr, hopcount, ttl,
538 cpu_to_le32(lifetime), cpu_to_le32(metric),
539 0, dev);
540 rcu_read_unlock();
541 sdata->u.sta.mshstats.fwded_frames++;
542 return;
543
544fail:
545 rcu_read_unlock();
546 sdata->u.sta.mshstats.dropped_frames_no_route++;
547 return;
548}
549
550static void hwmp_perr_frame_process(struct net_device *dev,
551 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
552{
553 struct mesh_path *mpath;
554 u8 *ta, *dst_addr;
555 u32 dst_dsn;
556
557 ta = mgmt->sa;
558 dst_addr = PERR_IE_DST_ADDR(perr_elem);
559 dst_dsn = PERR_IE_DST_DSN(perr_elem);
560 rcu_read_lock();
561 mpath = mesh_path_lookup(dst_addr, dev);
562 if (mpath) {
563 spin_lock_bh(&mpath->state_lock);
564 if (mpath->flags & MESH_PATH_ACTIVE &&
565 memcmp(ta, mpath->next_hop->addr, ETH_ALEN) == 0 &&
566 (!(mpath->flags & MESH_PATH_DSN_VALID) ||
567 DSN_GT(dst_dsn, mpath->dsn))) {
568 mpath->flags &= ~MESH_PATH_ACTIVE;
569 mpath->dsn = dst_dsn;
570 spin_unlock_bh(&mpath->state_lock);
571 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn),
572 dev->broadcast, dev);
573 } else
574 spin_unlock_bh(&mpath->state_lock);
575 }
576 rcu_read_unlock();
577}
578
579
580
581void mesh_rx_path_sel_frame(struct net_device *dev,
582 struct ieee80211_mgmt *mgmt,
583 size_t len)
584{
585 struct ieee802_11_elems elems;
586 size_t baselen;
587 u32 last_hop_metric;
588
589 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
590 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
591 len - baselen, &elems);
592
593 switch (mgmt->u.action.u.mesh_action.action_code) {
594 case MPATH_PREQ:
595 if (!elems.preq || elems.preq_len != 37)
596 /* Right now we support just 1 destination and no AE */
597 return;
598 last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.preq);
599 if (!last_hop_metric)
600 return;
601 hwmp_preq_frame_process(dev, mgmt, elems.preq, last_hop_metric);
602 break;
603 case MPATH_PREP:
604 if (!elems.prep || elems.prep_len != 31)
605 /* Right now we support no AE */
606 return;
607 last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.prep);
608 if (!last_hop_metric)
609 return;
610 hwmp_prep_frame_process(dev, mgmt, elems.prep, last_hop_metric);
611 break;
612 case MPATH_PERR:
613 if (!elems.perr || elems.perr_len != 12)
614 /* Right now we support only one destination per PERR */
615 return;
616 hwmp_perr_frame_process(dev, mgmt, elems.perr);
617 default:
618 return;
619 }
620
621}
622
623/**
624 * mesh_queue_preq - queue a PREQ to a given destination
625 *
626 * @mpath: mesh path to discover
627 * @flags: special attributes of the PREQ to be sent
628 *
629 * Locking: the function must be called from within a rcu read lock block.
630 *
631 */
632static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
633{
634 struct ieee80211_sub_if_data *sdata =
635 IEEE80211_DEV_TO_SUB_IF(mpath->dev);
636 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
637 struct mesh_preq_queue *preq_node;
638
639 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL);
640 if (!preq_node) {
641 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n");
642 return;
643 }
644
645 spin_lock(&ifsta->mesh_preq_queue_lock);
646 if (ifsta->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
647 spin_unlock(&ifsta->mesh_preq_queue_lock);
648 kfree(preq_node);
649 if (printk_ratelimit())
650 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n");
651 return;
652 }
653
654 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
655 preq_node->flags = flags;
656
657 list_add_tail(&preq_node->list, &ifsta->preq_queue.list);
658 ++ifsta->preq_queue_len;
659 spin_unlock(&ifsta->mesh_preq_queue_lock);
660
661 if (time_after(jiffies, ifsta->last_preq + min_preq_int_jiff(sdata)))
662 queue_work(sdata->local->hw.workqueue, &ifsta->work);
663
664 else if (time_before(jiffies, ifsta->last_preq)) {
665 /* avoid long wait if did not send preqs for a long time
666 * and jiffies wrapped around
667 */
668 ifsta->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
669 queue_work(sdata->local->hw.workqueue, &ifsta->work);
670 } else
671 mod_timer(&ifsta->mesh_path_timer, ifsta->last_preq +
672 min_preq_int_jiff(sdata));
673}
674
675/**
676 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
677 *
678 * @dev: local mesh interface
679 */
680void mesh_path_start_discovery(struct net_device *dev)
681{
682 struct ieee80211_sub_if_data *sdata =
683 IEEE80211_DEV_TO_SUB_IF(dev);
684 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
685 struct mesh_preq_queue *preq_node;
686 struct mesh_path *mpath;
687 u8 ttl, dst_flags;
688 u32 lifetime;
689
690 spin_lock(&ifsta->mesh_preq_queue_lock);
691 if (!ifsta->preq_queue_len ||
692 time_before(jiffies, ifsta->last_preq +
693 min_preq_int_jiff(sdata))) {
694 spin_unlock(&ifsta->mesh_preq_queue_lock);
695 return;
696 }
697
698 preq_node = list_first_entry(&ifsta->preq_queue.list,
699 struct mesh_preq_queue, list);
700 list_del(&preq_node->list);
701 --ifsta->preq_queue_len;
702 spin_unlock(&ifsta->mesh_preq_queue_lock);
703
704 rcu_read_lock();
705 mpath = mesh_path_lookup(preq_node->dst, dev);
706 if (!mpath)
707 goto enddiscovery;
708
709 spin_lock_bh(&mpath->state_lock);
710 if (preq_node->flags & PREQ_Q_F_START) {
711 if (mpath->flags & MESH_PATH_RESOLVING) {
712 spin_unlock_bh(&mpath->state_lock);
713 goto enddiscovery;
714 } else {
715 mpath->flags &= ~MESH_PATH_RESOLVED;
716 mpath->flags |= MESH_PATH_RESOLVING;
717 mpath->discovery_retries = 0;
718 mpath->discovery_timeout = disc_timeout_jiff(sdata);
719 }
720 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
721 mpath->flags & MESH_PATH_RESOLVED) {
722 mpath->flags &= ~MESH_PATH_RESOLVING;
723 spin_unlock_bh(&mpath->state_lock);
724 goto enddiscovery;
725 }
726
727 ifsta->last_preq = jiffies;
728
729 if (time_after(jiffies, ifsta->last_dsn_update +
730 net_traversal_jiffies(sdata)) ||
731 time_before(jiffies, ifsta->last_dsn_update)) {
732 ++ifsta->dsn;
733 sdata->u.sta.last_dsn_update = jiffies;
734 }
735 lifetime = default_lifetime(sdata);
736 ttl = sdata->u.sta.mshcfg.dot11MeshTTL;
737 if (ttl == 0) {
738 sdata->u.sta.mshstats.dropped_frames_ttl++;
739 spin_unlock_bh(&mpath->state_lock);
740 goto enddiscovery;
741 }
742
743 if (preq_node->flags & PREQ_Q_F_REFRESH)
744 dst_flags = MP_F_DO;
745 else
746 dst_flags = MP_F_RF;
747
748 spin_unlock_bh(&mpath->state_lock);
749 mesh_path_sel_frame_tx(MPATH_PREQ, 0, dev->dev_addr,
750 cpu_to_le32(ifsta->dsn), dst_flags, mpath->dst,
751 cpu_to_le32(mpath->dsn), dev->broadcast, 0,
752 ttl, cpu_to_le32(lifetime), 0,
753 cpu_to_le32(ifsta->preq_id++), dev);
754 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
755
756enddiscovery:
757 rcu_read_unlock();
758 kfree(preq_node);
759}
760
761/**
762 * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame
763 *
764 * @next_hop: output argument for next hop address
765 * @skb: frame to be sent
766 * @dev: network device the frame will be sent through
767 *
768 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
769 * found, the function will start a path discovery and queue the frame so it is
770 * sent when the path is resolved. This means the caller must not free the skb
771 * in this case.
772 */
773int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb,
774 struct net_device *dev)
775{
776 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
777 struct sk_buff *skb_to_free = NULL;
778 struct mesh_path *mpath;
779 int err = 0;
780
781 rcu_read_lock();
782 mpath = mesh_path_lookup(skb->data, dev);
783
784 if (!mpath) {
785 mesh_path_add(skb->data, dev);
786 mpath = mesh_path_lookup(skb->data, dev);
787 if (!mpath) {
788 dev_kfree_skb(skb);
789 sdata->u.sta.mshstats.dropped_frames_no_route++;
790 err = -ENOSPC;
791 goto endlookup;
792 }
793 }
794
795 if (mpath->flags & MESH_PATH_ACTIVE) {
796 if (time_after(jiffies, mpath->exp_time -
797 msecs_to_jiffies(sdata->u.sta.mshcfg.path_refresh_time))
798 && skb->pkt_type != PACKET_OTHERHOST
799 && !(mpath->flags & MESH_PATH_RESOLVING)
800 && !(mpath->flags & MESH_PATH_FIXED)) {
801 mesh_queue_preq(mpath,
802 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
803 }
804 memcpy(next_hop, mpath->next_hop->addr,
805 ETH_ALEN);
806 } else {
807 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
808 /* Start discovery only if it is not running yet */
809 mesh_queue_preq(mpath, PREQ_Q_F_START);
810 }
811
812 if (skb_queue_len(&mpath->frame_queue) >=
813 MESH_FRAME_QUEUE_LEN) {
814 skb_to_free = mpath->frame_queue.next;
815 skb_unlink(skb_to_free, &mpath->frame_queue);
816 }
817
818 skb_queue_tail(&mpath->frame_queue, skb);
819 if (skb_to_free)
820 mesh_path_discard_frame(skb_to_free, dev);
821 err = -ENOENT;
822 }
823
824endlookup:
825 rcu_read_unlock();
826 return err;
827}
828
829void mesh_path_timer(unsigned long data)
830{
831 struct ieee80211_sub_if_data *sdata;
832 struct mesh_path *mpath;
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_RESOLVED ||
842 (!(mpath->flags & MESH_PATH_RESOLVING)))
843 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
844 else if (mpath->discovery_retries < max_preq_retries(sdata)) {
845 ++mpath->discovery_retries;
846 mpath->discovery_timeout *= 2;
847 mesh_queue_preq(mpath, 0);
848 } else {
849 mpath->flags = 0;
850 mpath->exp_time = jiffies;
851 mesh_path_flush_pending(mpath);
852 }
853
854 spin_unlock_bh(&mpath->state_lock);
855endmpathtimer:
856 rcu_read_unlock();
857}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-28 08:16:23 -0500