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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / mac80211 / mesh_hwmp.c
blob35ad3983ae4b6b26fb13f6718b692c9b9b0d6e98
1 /*
2 * Copyright (c) 2008, 2009 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 <linux/slab.h>
11 #include <linux/etherdevice.h>
12 #include <asm/unaligned.h>
13 #include "wme.h"
14 #include "mesh.h"
15
16 #define TEST_FRAME_LEN 8192
17 #define MAX_METRIC 0xffffffff
18 #define ARITH_SHIFT 8
19 #define LINK_FAIL_THRESH 95
20
21 #define MAX_PREQ_QUEUE_LEN 64
22
23 static void mesh_queue_preq(struct mesh_path *, u8);
24
25 static inline u32 u32_field_get(const 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 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
33 {
34 if (ae)
35 offset += 6;
36 return get_unaligned_le16(preq_elem + offset);
37 }
38
39 /* HWMP IE processing macros */
40 #define AE_F (1<<6)
41 #define AE_F_SET(x) (*x & AE_F)
42 #define PREQ_IE_FLAGS(x) (*(x))
43 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
44 #define PREQ_IE_TTL(x) (*(x + 2))
45 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
46 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
47 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
48 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
49 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
50 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
51 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
52 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
53
54
55 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
56 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
57 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
58 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
59 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
60 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
61 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
62 #define PREP_IE_TARGET_ADDR(x) (x + 3)
63 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
64
65 #define PERR_IE_TTL(x) (*(x))
66 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
67 #define PERR_IE_TARGET_ADDR(x) (x + 3)
68 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
69 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
70
71 #define MSEC_TO_TU(x) (x*1000/1024)
72 #define SN_GT(x, y) ((s32)(y - x) < 0)
73 #define SN_LT(x, y) ((s32)(x - y) < 0)
74 #define MAX_SANE_SN_DELTA 32
75
76 static inline u32 SN_DELTA(u32 x, u32 y)
77 {
78 return x >= y ? x - y : y - x;
79 }
80
81 #define net_traversal_jiffies(s) \
82 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
83 #define default_lifetime(s) \
84 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
85 #define min_preq_int_jiff(s) \
86 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
87 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
88 #define disc_timeout_jiff(s) \
89 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
90 #define root_path_confirmation_jiffies(s) \
91 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
92
93 enum mpath_frame_type {
94 MPATH_PREQ = 0,
95 MPATH_PREP,
96 MPATH_PERR,
97 MPATH_RANN
98 };
99
100 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
101
102 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
103 const u8 *orig_addr, u32 orig_sn,
104 u8 target_flags, const u8 *target,
105 u32 target_sn, const u8 *da,
106 u8 hop_count, u8 ttl,
107 u32 lifetime, u32 metric, u32 preq_id,
108 struct ieee80211_sub_if_data *sdata)
109 {
110 struct ieee80211_local *local = sdata->local;
111 struct sk_buff *skb;
112 struct ieee80211_mgmt *mgmt;
113 u8 *pos, ie_len;
114 int hdr_len = offsetofend(struct ieee80211_mgmt,
115 u.action.u.mesh_action);
116
117 skb = dev_alloc_skb(local->tx_headroom +
118 hdr_len +
119 2 + 37); /* max HWMP IE */
120 if (!skb)
121 return -1;
122 skb_reserve(skb, local->tx_headroom);
123 mgmt = skb_put_zero(skb, hdr_len);
124 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
125 IEEE80211_STYPE_ACTION);
126
127 memcpy(mgmt->da, da, ETH_ALEN);
128 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
129 /* BSSID == SA */
130 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
131 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
132 mgmt->u.action.u.mesh_action.action_code =
133 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
134
135 switch (action) {
136 case MPATH_PREQ:
137 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
138 ie_len = 37;
139 pos = skb_put(skb, 2 + ie_len);
140 *pos++ = WLAN_EID_PREQ;
141 break;
142 case MPATH_PREP:
143 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
144 ie_len = 31;
145 pos = skb_put(skb, 2 + ie_len);
146 *pos++ = WLAN_EID_PREP;
147 break;
148 case MPATH_RANN:
149 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
150 ie_len = sizeof(struct ieee80211_rann_ie);
151 pos = skb_put(skb, 2 + ie_len);
152 *pos++ = WLAN_EID_RANN;
153 break;
154 default:
155 kfree_skb(skb);
156 return -ENOTSUPP;
157 }
158 *pos++ = ie_len;
159 *pos++ = flags;
160 *pos++ = hop_count;
161 *pos++ = ttl;
162 if (action == MPATH_PREP) {
163 memcpy(pos, target, ETH_ALEN);
164 pos += ETH_ALEN;
165 put_unaligned_le32(target_sn, pos);
166 pos += 4;
167 } else {
168 if (action == MPATH_PREQ) {
169 put_unaligned_le32(preq_id, pos);
170 pos += 4;
171 }
172 memcpy(pos, orig_addr, ETH_ALEN);
173 pos += ETH_ALEN;
174 put_unaligned_le32(orig_sn, pos);
175 pos += 4;
176 }
177 put_unaligned_le32(lifetime, pos); /* interval for RANN */
178 pos += 4;
179 put_unaligned_le32(metric, pos);
180 pos += 4;
181 if (action == MPATH_PREQ) {
182 *pos++ = 1; /* destination count */
183 *pos++ = target_flags;
184 memcpy(pos, target, ETH_ALEN);
185 pos += ETH_ALEN;
186 put_unaligned_le32(target_sn, pos);
187 pos += 4;
188 } else if (action == MPATH_PREP) {
189 memcpy(pos, orig_addr, ETH_ALEN);
190 pos += ETH_ALEN;
191 put_unaligned_le32(orig_sn, pos);
192 pos += 4;
193 }
194
195 ieee80211_tx_skb(sdata, skb);
196 return 0;
197 }
198
199
200 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
201 * headroom in case the frame is encrypted. */
202 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
203 struct sk_buff *skb)
204 {
205 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
206 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
207
208 skb_reset_mac_header(skb);
209 skb_reset_network_header(skb);
210 skb_reset_transport_header(skb);
211
212 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
213 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
214 skb->priority = 7;
215
216 info->control.vif = &sdata->vif;
217 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
218 ieee80211_set_qos_hdr(sdata, skb);
219 ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
220 }
221
222 /**
223 * mesh_path_error_tx - Sends a PERR mesh management frame
224 *
225 * @ttl: allowed remaining hops
226 * @target: broken destination
227 * @target_sn: SN of the broken destination
228 * @target_rcode: reason code for this PERR
229 * @ra: node this frame is addressed to
230 * @sdata: local mesh subif
231 *
232 * Note: This function may be called with driver locks taken that the driver
233 * also acquires in the TX path. To avoid a deadlock we don't transmit the
234 * frame directly but add it to the pending queue instead.
235 */
236 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
237 u8 ttl, const u8 *target, u32 target_sn,
238 u16 target_rcode, const u8 *ra)
239 {
240 struct ieee80211_local *local = sdata->local;
241 struct sk_buff *skb;
242 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
243 struct ieee80211_mgmt *mgmt;
244 u8 *pos, ie_len;
245 int hdr_len = offsetofend(struct ieee80211_mgmt,
246 u.action.u.mesh_action);
247
248 if (time_before(jiffies, ifmsh->next_perr))
249 return -EAGAIN;
250
251 skb = dev_alloc_skb(local->tx_headroom +
252 sdata->encrypt_headroom +
253 IEEE80211_ENCRYPT_TAILROOM +
254 hdr_len +
255 2 + 15 /* PERR IE */);
256 if (!skb)
257 return -1;
258 skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
259 mgmt = skb_put_zero(skb, hdr_len);
260 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
261 IEEE80211_STYPE_ACTION);
262
263 memcpy(mgmt->da, ra, ETH_ALEN);
264 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
265 /* BSSID == SA */
266 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
267 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
268 mgmt->u.action.u.mesh_action.action_code =
269 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
270 ie_len = 15;
271 pos = skb_put(skb, 2 + ie_len);
272 *pos++ = WLAN_EID_PERR;
273 *pos++ = ie_len;
274 /* ttl */
275 *pos++ = ttl;
276 /* number of destinations */
277 *pos++ = 1;
278 /* Flags field has AE bit only as defined in
279 * sec 8.4.2.117 IEEE802.11-2012
280 */
281 *pos = 0;
282 pos++;
283 memcpy(pos, target, ETH_ALEN);
284 pos += ETH_ALEN;
285 put_unaligned_le32(target_sn, pos);
286 pos += 4;
287 put_unaligned_le16(target_rcode, pos);
288
289 /* see note in function header */
290 prepare_frame_for_deferred_tx(sdata, skb);
291 ifmsh->next_perr = TU_TO_EXP_TIME(
292 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
293 ieee80211_add_pending_skb(local, skb);
294 return 0;
295 }
296
297 void ieee80211s_update_metric(struct ieee80211_local *local,
298 struct sta_info *sta, struct sk_buff *skb)
299 {
300 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
301 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
302 int failed;
303
304 if (!ieee80211_is_data(hdr->frame_control))
305 return;
306
307 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
308
309 /* moving average, scaled to 100.
310 * feed failure as 100 and success as 0
311 */
312 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
313 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
314 LINK_FAIL_THRESH)
315 mesh_plink_broken(sta);
316 }
317
318 static u32 airtime_link_metric_get(struct ieee80211_local *local,
319 struct sta_info *sta)
320 {
321 struct rate_info rinfo;
322 /* This should be adjusted for each device */
323 int device_constant = 1 << ARITH_SHIFT;
324 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
325 int s_unit = 1 << ARITH_SHIFT;
326 int rate, err;
327 u32 tx_time, estimated_retx;
328 u64 result;
329 unsigned long fail_avg =
330 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
331
332 /* Try to get rate based on HW/SW RC algorithm.
333 * Rate is returned in units of Kbps, correct this
334 * to comply with airtime calculation units
335 * Round up in case we get rate < 100Kbps
336 */
337 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
338
339 if (rate) {
340 err = 0;
341 } else {
342 if (fail_avg > LINK_FAIL_THRESH)
343 return MAX_METRIC;
344
345 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
346 rate = cfg80211_calculate_bitrate(&rinfo);
347 if (WARN_ON(!rate))
348 return MAX_METRIC;
349
350 err = (fail_avg << ARITH_SHIFT) / 100;
351 }
352
353 /* bitrate is in units of 100 Kbps, while we need rate in units of
354 * 1Mbps. This will be corrected on tx_time computation.
355 */
356 tx_time = (device_constant + 10 * test_frame_len / rate);
357 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
358 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
359 return (u32)result;
360 }
361
362 /**
363 * hwmp_route_info_get - Update routing info to originator and transmitter
364 *
365 * @sdata: local mesh subif
366 * @mgmt: mesh management frame
367 * @hwmp_ie: hwmp information element (PREP or PREQ)
368 * @action: type of hwmp ie
369 *
370 * This function updates the path routing information to the originator and the
371 * transmitter of a HWMP PREQ or PREP frame.
372 *
373 * Returns: metric to frame originator or 0 if the frame should not be further
374 * processed
375 *
376 * Notes: this function is the only place (besides user-provided info) where
377 * path routing information is updated.
378 */
379 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
380 struct ieee80211_mgmt *mgmt,
381 const u8 *hwmp_ie, enum mpath_frame_type action)
382 {
383 struct ieee80211_local *local = sdata->local;
384 struct mesh_path *mpath;
385 struct sta_info *sta;
386 bool fresh_info;
387 const u8 *orig_addr, *ta;
388 u32 orig_sn, orig_metric;
389 unsigned long orig_lifetime, exp_time;
390 u32 last_hop_metric, new_metric;
391 bool process = true;
392
393 rcu_read_lock();
394 sta = sta_info_get(sdata, mgmt->sa);
395 if (!sta) {
396 rcu_read_unlock();
397 return 0;
398 }
399
400 last_hop_metric = airtime_link_metric_get(local, sta);
401 /* Update and check originator routing info */
402 fresh_info = true;
403
404 switch (action) {
405 case MPATH_PREQ:
406 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
407 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
408 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
409 orig_metric = PREQ_IE_METRIC(hwmp_ie);
410 break;
411 case MPATH_PREP:
412 /* Originator here refers to the MP that was the target in the
413 * Path Request. We divert from the nomenclature in the draft
414 * so that we can easily use a single function to gather path
415 * information from both PREQ and PREP frames.
416 */
417 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
418 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
419 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
420 orig_metric = PREP_IE_METRIC(hwmp_ie);
421 break;
422 default:
423 rcu_read_unlock();
424 return 0;
425 }
426 new_metric = orig_metric + last_hop_metric;
427 if (new_metric < orig_metric)
428 new_metric = MAX_METRIC;
429 exp_time = TU_TO_EXP_TIME(orig_lifetime);
430
431 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
432 /* This MP is the originator, we are not interested in this
433 * frame, except for updating transmitter's path info.
434 */
435 process = false;
436 fresh_info = false;
437 } else {
438 mpath = mesh_path_lookup(sdata, orig_addr);
439 if (mpath) {
440 spin_lock_bh(&mpath->state_lock);
441 if (mpath->flags & MESH_PATH_FIXED)
442 fresh_info = false;
443 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
444 (mpath->flags & MESH_PATH_SN_VALID)) {
445 if (SN_GT(mpath->sn, orig_sn) ||
446 (mpath->sn == orig_sn &&
447 new_metric >= mpath->metric)) {
448 process = false;
449 fresh_info = false;
450 }
451 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
452 bool have_sn, newer_sn, bounced;
453
454 have_sn = mpath->flags & MESH_PATH_SN_VALID;
455 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
456 bounced = have_sn &&
457 (SN_DELTA(orig_sn, mpath->sn) >
458 MAX_SANE_SN_DELTA);
459
460 if (!have_sn || newer_sn) {
461 /* if SN is newer than what we had
462 * then we can take it */;
463 } else if (bounced) {
464 /* if SN is way different than what
465 * we had then assume the other side
466 * rebooted or restarted */;
467 } else {
468 process = false;
469 fresh_info = false;
470 }
471 }
472 } else {
473 mpath = mesh_path_add(sdata, orig_addr);
474 if (IS_ERR(mpath)) {
475 rcu_read_unlock();
476 return 0;
477 }
478 spin_lock_bh(&mpath->state_lock);
479 }
480
481 if (fresh_info) {
482 mesh_path_assign_nexthop(mpath, sta);
483 mpath->flags |= MESH_PATH_SN_VALID;
484 mpath->metric = new_metric;
485 mpath->sn = orig_sn;
486 mpath->exp_time = time_after(mpath->exp_time, exp_time)
487 ? mpath->exp_time : exp_time;
488 mesh_path_activate(mpath);
489 spin_unlock_bh(&mpath->state_lock);
490 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
491 /* init it at a low value - 0 start is tricky */
492 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
493 mesh_path_tx_pending(mpath);
494 /* draft says preq_id should be saved to, but there does
495 * not seem to be any use for it, skipping by now
496 */
497 } else
498 spin_unlock_bh(&mpath->state_lock);
499 }
500
501 /* Update and check transmitter routing info */
502 ta = mgmt->sa;
503 if (ether_addr_equal(orig_addr, ta))
504 fresh_info = false;
505 else {
506 fresh_info = true;
507
508 mpath = mesh_path_lookup(sdata, ta);
509 if (mpath) {
510 spin_lock_bh(&mpath->state_lock);
511 if ((mpath->flags & MESH_PATH_FIXED) ||
512 ((mpath->flags & MESH_PATH_ACTIVE) &&
513 (last_hop_metric > mpath->metric)))
514 fresh_info = false;
515 } else {
516 mpath = mesh_path_add(sdata, ta);
517 if (IS_ERR(mpath)) {
518 rcu_read_unlock();
519 return 0;
520 }
521 spin_lock_bh(&mpath->state_lock);
522 }
523
524 if (fresh_info) {
525 mesh_path_assign_nexthop(mpath, sta);
526 mpath->metric = last_hop_metric;
527 mpath->exp_time = time_after(mpath->exp_time, exp_time)
528 ? mpath->exp_time : exp_time;
529 mesh_path_activate(mpath);
530 spin_unlock_bh(&mpath->state_lock);
531 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
532 /* init it at a low value - 0 start is tricky */
533 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
534 mesh_path_tx_pending(mpath);
535 } else
536 spin_unlock_bh(&mpath->state_lock);
537 }
538
539 rcu_read_unlock();
540
541 return process ? new_metric : 0;
542 }
543
544 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
545 struct ieee80211_mgmt *mgmt,
546 const u8 *preq_elem, u32 orig_metric)
547 {
548 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
549 struct mesh_path *mpath = NULL;
550 const u8 *target_addr, *orig_addr;
551 const u8 *da;
552 u8 target_flags, ttl, flags;
553 u32 orig_sn, target_sn, lifetime, target_metric = 0;
554 bool reply = false;
555 bool forward = true;
556 bool root_is_gate;
557
558 /* Update target SN, if present */
559 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
560 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
561 target_sn = PREQ_IE_TARGET_SN(preq_elem);
562 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
563 target_flags = PREQ_IE_TARGET_F(preq_elem);
564 /* Proactive PREQ gate announcements */
565 flags = PREQ_IE_FLAGS(preq_elem);
566 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
567
568 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
569
570 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
571 mhwmp_dbg(sdata, "PREQ is for us\n");
572 forward = false;
573 reply = true;
574 target_metric = 0;
575 if (time_after(jiffies, ifmsh->last_sn_update +
576 net_traversal_jiffies(sdata)) ||
577 time_before(jiffies, ifmsh->last_sn_update)) {
578 ++ifmsh->sn;
579 ifmsh->last_sn_update = jiffies;
580 }
581 target_sn = ifmsh->sn;
582 } else if (is_broadcast_ether_addr(target_addr) &&
583 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
584 rcu_read_lock();
585 mpath = mesh_path_lookup(sdata, orig_addr);
586 if (mpath) {
587 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
588 reply = true;
589 target_addr = sdata->vif.addr;
590 target_sn = ++ifmsh->sn;
591 target_metric = 0;
592 ifmsh->last_sn_update = jiffies;
593 }
594 if (root_is_gate)
595 mesh_path_add_gate(mpath);
596 }
597 rcu_read_unlock();
598 } else {
599 rcu_read_lock();
600 mpath = mesh_path_lookup(sdata, target_addr);
601 if (mpath) {
602 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
603 SN_LT(mpath->sn, target_sn)) {
604 mpath->sn = target_sn;
605 mpath->flags |= MESH_PATH_SN_VALID;
606 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
607 (mpath->flags & MESH_PATH_ACTIVE)) {
608 reply = true;
609 target_metric = mpath->metric;
610 target_sn = mpath->sn;
611 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
612 target_flags |= IEEE80211_PREQ_TO_FLAG;
613 }
614 }
615 rcu_read_unlock();
616 }
617
618 if (reply) {
619 lifetime = PREQ_IE_LIFETIME(preq_elem);
620 ttl = ifmsh->mshcfg.element_ttl;
621 if (ttl != 0) {
622 mhwmp_dbg(sdata, "replying to the PREQ\n");
623 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
624 orig_sn, 0, target_addr,
625 target_sn, mgmt->sa, 0, ttl,
626 lifetime, target_metric, 0,
627 sdata);
628 } else {
629 ifmsh->mshstats.dropped_frames_ttl++;
630 }
631 }
632
633 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
634 u32 preq_id;
635 u8 hopcount;
636
637 ttl = PREQ_IE_TTL(preq_elem);
638 lifetime = PREQ_IE_LIFETIME(preq_elem);
639 if (ttl <= 1) {
640 ifmsh->mshstats.dropped_frames_ttl++;
641 return;
642 }
643 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
644 --ttl;
645 preq_id = PREQ_IE_PREQ_ID(preq_elem);
646 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
647 da = (mpath && mpath->is_root) ?
648 mpath->rann_snd_addr : broadcast_addr;
649
650 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
651 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
652 target_sn = PREQ_IE_TARGET_SN(preq_elem);
653 }
654
655 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
656 orig_sn, target_flags, target_addr,
657 target_sn, da, hopcount, ttl, lifetime,
658 orig_metric, preq_id, sdata);
659 if (!is_multicast_ether_addr(da))
660 ifmsh->mshstats.fwded_unicast++;
661 else
662 ifmsh->mshstats.fwded_mcast++;
663 ifmsh->mshstats.fwded_frames++;
664 }
665 }
666
667
668 static inline struct sta_info *
669 next_hop_deref_protected(struct mesh_path *mpath)
670 {
671 return rcu_dereference_protected(mpath->next_hop,
672 lockdep_is_held(&mpath->state_lock));
673 }
674
675
676 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
677 struct ieee80211_mgmt *mgmt,
678 const u8 *prep_elem, u32 metric)
679 {
680 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
681 struct mesh_path *mpath;
682 const u8 *target_addr, *orig_addr;
683 u8 ttl, hopcount, flags;
684 u8 next_hop[ETH_ALEN];
685 u32 target_sn, orig_sn, lifetime;
686
687 mhwmp_dbg(sdata, "received PREP from %pM\n",
688 PREP_IE_TARGET_ADDR(prep_elem));
689
690 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
691 if (ether_addr_equal(orig_addr, sdata->vif.addr))
692 /* destination, no forwarding required */
693 return;
694
695 if (!ifmsh->mshcfg.dot11MeshForwarding)
696 return;
697
698 ttl = PREP_IE_TTL(prep_elem);
699 if (ttl <= 1) {
700 sdata->u.mesh.mshstats.dropped_frames_ttl++;
701 return;
702 }
703
704 rcu_read_lock();
705 mpath = mesh_path_lookup(sdata, orig_addr);
706 if (mpath)
707 spin_lock_bh(&mpath->state_lock);
708 else
709 goto fail;
710 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
711 spin_unlock_bh(&mpath->state_lock);
712 goto fail;
713 }
714 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
715 spin_unlock_bh(&mpath->state_lock);
716 --ttl;
717 flags = PREP_IE_FLAGS(prep_elem);
718 lifetime = PREP_IE_LIFETIME(prep_elem);
719 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
720 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
721 target_sn = PREP_IE_TARGET_SN(prep_elem);
722 orig_sn = PREP_IE_ORIG_SN(prep_elem);
723
724 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
725 target_addr, target_sn, next_hop, hopcount,
726 ttl, lifetime, metric, 0, sdata);
727 rcu_read_unlock();
728
729 sdata->u.mesh.mshstats.fwded_unicast++;
730 sdata->u.mesh.mshstats.fwded_frames++;
731 return;
732
733 fail:
734 rcu_read_unlock();
735 sdata->u.mesh.mshstats.dropped_frames_no_route++;
736 }
737
738 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
739 struct ieee80211_mgmt *mgmt,
740 const u8 *perr_elem)
741 {
742 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
743 struct mesh_path *mpath;
744 u8 ttl;
745 const u8 *ta, *target_addr;
746 u32 target_sn;
747 u16 target_rcode;
748
749 ta = mgmt->sa;
750 ttl = PERR_IE_TTL(perr_elem);
751 if (ttl <= 1) {
752 ifmsh->mshstats.dropped_frames_ttl++;
753 return;
754 }
755 ttl--;
756 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
757 target_sn = PERR_IE_TARGET_SN(perr_elem);
758 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
759
760 rcu_read_lock();
761 mpath = mesh_path_lookup(sdata, target_addr);
762 if (mpath) {
763 struct sta_info *sta;
764
765 spin_lock_bh(&mpath->state_lock);
766 sta = next_hop_deref_protected(mpath);
767 if (mpath->flags & MESH_PATH_ACTIVE &&
768 ether_addr_equal(ta, sta->sta.addr) &&
769 !(mpath->flags & MESH_PATH_FIXED) &&
770 (!(mpath->flags & MESH_PATH_SN_VALID) ||
771 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
772 mpath->flags &= ~MESH_PATH_ACTIVE;
773 if (target_sn != 0)
774 mpath->sn = target_sn;
775 else
776 mpath->sn += 1;
777 spin_unlock_bh(&mpath->state_lock);
778 if (!ifmsh->mshcfg.dot11MeshForwarding)
779 goto endperr;
780 mesh_path_error_tx(sdata, ttl, target_addr,
781 target_sn, target_rcode,
782 broadcast_addr);
783 } else
784 spin_unlock_bh(&mpath->state_lock);
785 }
786 endperr:
787 rcu_read_unlock();
788 }
789
790 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
791 struct ieee80211_mgmt *mgmt,
792 const struct ieee80211_rann_ie *rann)
793 {
794 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
795 struct ieee80211_local *local = sdata->local;
796 struct sta_info *sta;
797 struct mesh_path *mpath;
798 u8 ttl, flags, hopcount;
799 const u8 *orig_addr;
800 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
801 bool root_is_gate;
802
803 ttl = rann->rann_ttl;
804 flags = rann->rann_flags;
805 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
806 orig_addr = rann->rann_addr;
807 orig_sn = le32_to_cpu(rann->rann_seq);
808 interval = le32_to_cpu(rann->rann_interval);
809 hopcount = rann->rann_hopcount;
810 hopcount++;
811 orig_metric = le32_to_cpu(rann->rann_metric);
812
813 /* Ignore our own RANNs */
814 if (ether_addr_equal(orig_addr, sdata->vif.addr))
815 return;
816
817 mhwmp_dbg(sdata,
818 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
819 orig_addr, mgmt->sa, root_is_gate);
820
821 rcu_read_lock();
822 sta = sta_info_get(sdata, mgmt->sa);
823 if (!sta) {
824 rcu_read_unlock();
825 return;
826 }
827
828 last_hop_metric = airtime_link_metric_get(local, sta);
829 new_metric = orig_metric + last_hop_metric;
830 if (new_metric < orig_metric)
831 new_metric = MAX_METRIC;
832
833 mpath = mesh_path_lookup(sdata, orig_addr);
834 if (!mpath) {
835 mpath = mesh_path_add(sdata, orig_addr);
836 if (IS_ERR(mpath)) {
837 rcu_read_unlock();
838 sdata->u.mesh.mshstats.dropped_frames_no_route++;
839 return;
840 }
841 }
842
843 if (!(SN_LT(mpath->sn, orig_sn)) &&
844 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
845 rcu_read_unlock();
846 return;
847 }
848
849 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
850 (time_after(jiffies, mpath->last_preq_to_root +
851 root_path_confirmation_jiffies(sdata)) ||
852 time_before(jiffies, mpath->last_preq_to_root))) &&
853 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
854 mhwmp_dbg(sdata,
855 "time to refresh root mpath %pM\n",
856 orig_addr);
857 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
858 mpath->last_preq_to_root = jiffies;
859 }
860
861 mpath->sn = orig_sn;
862 mpath->rann_metric = new_metric;
863 mpath->is_root = true;
864 /* Recording RANNs sender address to send individually
865 * addressed PREQs destined for root mesh STA */
866 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
867
868 if (root_is_gate)
869 mesh_path_add_gate(mpath);
870
871 if (ttl <= 1) {
872 ifmsh->mshstats.dropped_frames_ttl++;
873 rcu_read_unlock();
874 return;
875 }
876 ttl--;
877
878 if (ifmsh->mshcfg.dot11MeshForwarding) {
879 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
880 orig_sn, 0, NULL, 0, broadcast_addr,
881 hopcount, ttl, interval,
882 new_metric, 0, sdata);
883 }
884
885 rcu_read_unlock();
886 }
887
888
889 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
890 struct ieee80211_mgmt *mgmt, size_t len)
891 {
892 struct ieee802_11_elems elems;
893 size_t baselen;
894 u32 path_metric;
895 struct sta_info *sta;
896
897 /* need action_code */
898 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
899 return;
900
901 rcu_read_lock();
902 sta = sta_info_get(sdata, mgmt->sa);
903 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
904 rcu_read_unlock();
905 return;
906 }
907 rcu_read_unlock();
908
909 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
910 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
911 len - baselen, false, &elems);
912
913 if (elems.preq) {
914 if (elems.preq_len != 37)
915 /* Right now we support just 1 destination and no AE */
916 return;
917 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
918 MPATH_PREQ);
919 if (path_metric)
920 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
921 path_metric);
922 }
923 if (elems.prep) {
924 if (elems.prep_len != 31)
925 /* Right now we support no AE */
926 return;
927 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
928 MPATH_PREP);
929 if (path_metric)
930 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
931 path_metric);
932 }
933 if (elems.perr) {
934 if (elems.perr_len != 15)
935 /* Right now we support only one destination per PERR */
936 return;
937 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
938 }
939 if (elems.rann)
940 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
941 }
942
943 /**
944 * mesh_queue_preq - queue a PREQ to a given destination
945 *
946 * @mpath: mesh path to discover
947 * @flags: special attributes of the PREQ to be sent
948 *
949 * Locking: the function must be called from within a rcu read lock block.
950 *
951 */
952 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
953 {
954 struct ieee80211_sub_if_data *sdata = mpath->sdata;
955 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
956 struct mesh_preq_queue *preq_node;
957
958 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
959 if (!preq_node) {
960 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
961 return;
962 }
963
964 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
965 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
966 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
967 kfree(preq_node);
968 if (printk_ratelimit())
969 mhwmp_dbg(sdata, "PREQ node queue full\n");
970 return;
971 }
972
973 spin_lock(&mpath->state_lock);
974 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
975 spin_unlock(&mpath->state_lock);
976 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
977 kfree(preq_node);
978 return;
979 }
980
981 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
982 preq_node->flags = flags;
983
984 mpath->flags |= MESH_PATH_REQ_QUEUED;
985 spin_unlock(&mpath->state_lock);
986
987 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
988 ++ifmsh->preq_queue_len;
989 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
990
991 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
992 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
993
994 else if (time_before(jiffies, ifmsh->last_preq)) {
995 /* avoid long wait if did not send preqs for a long time
996 * and jiffies wrapped around
997 */
998 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
999 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1000 } else
1001 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1002 min_preq_int_jiff(sdata));
1003 }
1004
1005 /**
1006 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1007 *
1008 * @sdata: local mesh subif
1009 */
1010 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1011 {
1012 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1013 struct mesh_preq_queue *preq_node;
1014 struct mesh_path *mpath;
1015 u8 ttl, target_flags = 0;
1016 const u8 *da;
1017 u32 lifetime;
1018
1019 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1020 if (!ifmsh->preq_queue_len ||
1021 time_before(jiffies, ifmsh->last_preq +
1022 min_preq_int_jiff(sdata))) {
1023 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1024 return;
1025 }
1026
1027 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1028 struct mesh_preq_queue, list);
1029 list_del(&preq_node->list);
1030 --ifmsh->preq_queue_len;
1031 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1032
1033 rcu_read_lock();
1034 mpath = mesh_path_lookup(sdata, preq_node->dst);
1035 if (!mpath)
1036 goto enddiscovery;
1037
1038 spin_lock_bh(&mpath->state_lock);
1039 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1040 spin_unlock_bh(&mpath->state_lock);
1041 goto enddiscovery;
1042 }
1043 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1044 if (preq_node->flags & PREQ_Q_F_START) {
1045 if (mpath->flags & MESH_PATH_RESOLVING) {
1046 spin_unlock_bh(&mpath->state_lock);
1047 goto enddiscovery;
1048 } else {
1049 mpath->flags &= ~MESH_PATH_RESOLVED;
1050 mpath->flags |= MESH_PATH_RESOLVING;
1051 mpath->discovery_retries = 0;
1052 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1053 }
1054 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1055 mpath->flags & MESH_PATH_RESOLVED) {
1056 mpath->flags &= ~MESH_PATH_RESOLVING;
1057 spin_unlock_bh(&mpath->state_lock);
1058 goto enddiscovery;
1059 }
1060
1061 ifmsh->last_preq = jiffies;
1062
1063 if (time_after(jiffies, ifmsh->last_sn_update +
1064 net_traversal_jiffies(sdata)) ||
1065 time_before(jiffies, ifmsh->last_sn_update)) {
1066 ++ifmsh->sn;
1067 sdata->u.mesh.last_sn_update = jiffies;
1068 }
1069 lifetime = default_lifetime(sdata);
1070 ttl = sdata->u.mesh.mshcfg.element_ttl;
1071 if (ttl == 0) {
1072 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1073 spin_unlock_bh(&mpath->state_lock);
1074 goto enddiscovery;
1075 }
1076
1077 if (preq_node->flags & PREQ_Q_F_REFRESH)
1078 target_flags |= IEEE80211_PREQ_TO_FLAG;
1079 else
1080 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1081
1082 spin_unlock_bh(&mpath->state_lock);
1083 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1084 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1085 target_flags, mpath->dst, mpath->sn, da, 0,
1086 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1087 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1088
1089 enddiscovery:
1090 rcu_read_unlock();
1091 kfree(preq_node);
1092 }
1093
1094 /**
1095 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1096 *
1097 * @skb: 802.11 frame to be sent
1098 * @sdata: network subif the frame will be sent through
1099 *
1100 * Lookup next hop for given skb and start path discovery if no
1101 * forwarding information is found.
1102 *
1103 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1104 * skb is freeed here if no mpath could be allocated.
1105 */
1106 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1107 struct sk_buff *skb)
1108 {
1109 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1110 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1111 struct mesh_path *mpath;
1112 struct sk_buff *skb_to_free = NULL;
1113 u8 *target_addr = hdr->addr3;
1114 int err = 0;
1115
1116 /* Nulls are only sent to peers for PS and should be pre-addressed */
1117 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1118 return 0;
1119
1120 rcu_read_lock();
1121 err = mesh_nexthop_lookup(sdata, skb);
1122 if (!err)
1123 goto endlookup;
1124
1125 /* no nexthop found, start resolving */
1126 mpath = mesh_path_lookup(sdata, target_addr);
1127 if (!mpath) {
1128 mpath = mesh_path_add(sdata, target_addr);
1129 if (IS_ERR(mpath)) {
1130 mesh_path_discard_frame(sdata, skb);
1131 err = PTR_ERR(mpath);
1132 goto endlookup;
1133 }
1134 }
1135
1136 if (!(mpath->flags & MESH_PATH_RESOLVING))
1137 mesh_queue_preq(mpath, PREQ_Q_F_START);
1138
1139 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1140 skb_to_free = skb_dequeue(&mpath->frame_queue);
1141
1142 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1143 ieee80211_set_qos_hdr(sdata, skb);
1144 skb_queue_tail(&mpath->frame_queue, skb);
1145 err = -ENOENT;
1146 if (skb_to_free)
1147 mesh_path_discard_frame(sdata, skb_to_free);
1148
1149 endlookup:
1150 rcu_read_unlock();
1151 return err;
1152 }
1153
1154 /**
1155 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1156 * this function is considered "using" the associated mpath, so preempt a path
1157 * refresh if this mpath expires soon.
1158 *
1159 * @skb: 802.11 frame to be sent
1160 * @sdata: network subif the frame will be sent through
1161 *
1162 * Returns: 0 if the next hop was found. Nonzero otherwise.
1163 */
1164 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1165 struct sk_buff *skb)
1166 {
1167 struct mesh_path *mpath;
1168 struct sta_info *next_hop;
1169 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1170 u8 *target_addr = hdr->addr3;
1171 int err = -ENOENT;
1172
1173 rcu_read_lock();
1174 mpath = mesh_path_lookup(sdata, target_addr);
1175
1176 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1177 goto endlookup;
1178
1179 if (time_after(jiffies,
1180 mpath->exp_time -
1181 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1182 ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
1183 !(mpath->flags & MESH_PATH_RESOLVING) &&
1184 !(mpath->flags & MESH_PATH_FIXED))
1185 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1186
1187 next_hop = rcu_dereference(mpath->next_hop);
1188 if (next_hop) {
1189 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1190 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1191 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1192 err = 0;
1193 }
1194
1195 endlookup:
1196 rcu_read_unlock();
1197 return err;
1198 }
1199
1200 void mesh_path_timer(struct timer_list *t)
1201 {
1202 struct mesh_path *mpath = from_timer(mpath, t, timer);
1203 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1204 int ret;
1205
1206 if (sdata->local->quiescing)
1207 return;
1208
1209 spin_lock_bh(&mpath->state_lock);
1210 if (mpath->flags & MESH_PATH_RESOLVED ||
1211 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1212 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1213 spin_unlock_bh(&mpath->state_lock);
1214 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1215 ++mpath->discovery_retries;
1216 mpath->discovery_timeout *= 2;
1217 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1218 spin_unlock_bh(&mpath->state_lock);
1219 mesh_queue_preq(mpath, 0);
1220 } else {
1221 mpath->flags &= ~(MESH_PATH_RESOLVING |
1222 MESH_PATH_RESOLVED |
1223 MESH_PATH_REQ_QUEUED);
1224 mpath->exp_time = jiffies;
1225 spin_unlock_bh(&mpath->state_lock);
1226 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1227 ret = mesh_path_send_to_gates(mpath);
1228 if (ret)
1229 mhwmp_dbg(sdata, "no gate was reachable\n");
1230 } else
1231 mesh_path_flush_pending(mpath);
1232 }
1233 }
1234
1235 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1236 {
1237 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1238 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1239 u8 flags, target_flags = 0;
1240
1241 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1242 ? RANN_FLAG_IS_GATE : 0;
1243
1244 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1245 case IEEE80211_PROACTIVE_RANN:
1246 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1247 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1248 0, ifmsh->mshcfg.element_ttl,
1249 interval, 0, 0, sdata);
1250 break;
1251 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1252 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1253 /* fall through */
1254 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1255 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1256 target_flags |= IEEE80211_PREQ_TO_FLAG |
1257 IEEE80211_PREQ_USN_FLAG;
1258 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1259 ++ifmsh->sn, target_flags,
1260 (u8 *) broadcast_addr, 0, broadcast_addr,
1261 0, ifmsh->mshcfg.element_ttl, interval,
1262 0, ifmsh->preq_id++, sdata);
1263 break;
1264 default:
1265 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1266 return;
1267 }
1268 }
CRIS linux kernel tree