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Linux 5.1.15
[linux/fpc-iii.git] / net / mac80211 / mesh_hwmp.c
blobf7517668e77a0fdfd74003af482371ac6fc14f04
1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Copyright (C) 2019 Intel Corporation
4 * Author: Luis Carlos Cobo <luisca@cozybit.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/slab.h>
12 #include <linux/etherdevice.h>
13 #include <asm/unaligned.h>
14 #include "wme.h"
15 #include "mesh.h"
16
17 #define TEST_FRAME_LEN 8192
18 #define MAX_METRIC 0xffffffff
19 #define ARITH_SHIFT 8
20 #define LINK_FAIL_THRESH 95
21
22 #define MAX_PREQ_QUEUE_LEN 64
23
24 static void mesh_queue_preq(struct mesh_path *, u8);
25
26 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
27 {
28 if (ae)
29 offset += 6;
30 return get_unaligned_le32(preq_elem + offset);
31 }
32
33 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
34 {
35 if (ae)
36 offset += 6;
37 return get_unaligned_le16(preq_elem + offset);
38 }
39
40 /* HWMP IE processing macros */
41 #define AE_F (1<<6)
42 #define AE_F_SET(x) (*x & AE_F)
43 #define PREQ_IE_FLAGS(x) (*(x))
44 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
45 #define PREQ_IE_TTL(x) (*(x + 2))
46 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
47 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
48 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
49 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
50 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
51 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
52 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
53 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
54
55
56 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
57 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
58 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
59 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
60 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
61 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
62 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
63 #define PREP_IE_TARGET_ADDR(x) (x + 3)
64 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
65
66 #define PERR_IE_TTL(x) (*(x))
67 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
68 #define PERR_IE_TARGET_ADDR(x) (x + 3)
69 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
70 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
71
72 #define MSEC_TO_TU(x) (x*1000/1024)
73 #define SN_GT(x, y) ((s32)(y - x) < 0)
74 #define SN_LT(x, y) ((s32)(x - y) < 0)
75 #define MAX_SANE_SN_DELTA 32
76
77 static inline u32 SN_DELTA(u32 x, u32 y)
78 {
79 return x >= y ? x - y : y - x;
80 }
81
82 #define net_traversal_jiffies(s) \
83 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
84 #define default_lifetime(s) \
85 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
86 #define min_preq_int_jiff(s) \
87 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
88 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
89 #define disc_timeout_jiff(s) \
90 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
91 #define root_path_confirmation_jiffies(s) \
92 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
93
94 enum mpath_frame_type {
95 MPATH_PREQ = 0,
96 MPATH_PREP,
97 MPATH_PERR,
98 MPATH_RANN
99 };
100
101 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
102
103 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
104 const u8 *orig_addr, u32 orig_sn,
105 u8 target_flags, const u8 *target,
106 u32 target_sn, const u8 *da,
107 u8 hop_count, u8 ttl,
108 u32 lifetime, u32 metric, u32 preq_id,
109 struct ieee80211_sub_if_data *sdata)
110 {
111 struct ieee80211_local *local = sdata->local;
112 struct sk_buff *skb;
113 struct ieee80211_mgmt *mgmt;
114 u8 *pos, ie_len;
115 int hdr_len = offsetofend(struct ieee80211_mgmt,
116 u.action.u.mesh_action);
117
118 skb = dev_alloc_skb(local->tx_headroom +
119 hdr_len +
120 2 + 37); /* max HWMP IE */
121 if (!skb)
122 return -1;
123 skb_reserve(skb, local->tx_headroom);
124 mgmt = skb_put_zero(skb, hdr_len);
125 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
126 IEEE80211_STYPE_ACTION);
127
128 memcpy(mgmt->da, da, ETH_ALEN);
129 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
130 /* BSSID == SA */
131 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
132 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
133 mgmt->u.action.u.mesh_action.action_code =
134 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
135
136 switch (action) {
137 case MPATH_PREQ:
138 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
139 ie_len = 37;
140 pos = skb_put(skb, 2 + ie_len);
141 *pos++ = WLAN_EID_PREQ;
142 break;
143 case MPATH_PREP:
144 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
145 ie_len = 31;
146 pos = skb_put(skb, 2 + ie_len);
147 *pos++ = WLAN_EID_PREP;
148 break;
149 case MPATH_RANN:
150 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
151 ie_len = sizeof(struct ieee80211_rann_ie);
152 pos = skb_put(skb, 2 + ie_len);
153 *pos++ = WLAN_EID_RANN;
154 break;
155 default:
156 kfree_skb(skb);
157 return -ENOTSUPP;
158 }
159 *pos++ = ie_len;
160 *pos++ = flags;
161 *pos++ = hop_count;
162 *pos++ = ttl;
163 if (action == MPATH_PREP) {
164 memcpy(pos, target, ETH_ALEN);
165 pos += ETH_ALEN;
166 put_unaligned_le32(target_sn, pos);
167 pos += 4;
168 } else {
169 if (action == MPATH_PREQ) {
170 put_unaligned_le32(preq_id, pos);
171 pos += 4;
172 }
173 memcpy(pos, orig_addr, ETH_ALEN);
174 pos += ETH_ALEN;
175 put_unaligned_le32(orig_sn, pos);
176 pos += 4;
177 }
178 put_unaligned_le32(lifetime, pos); /* interval for RANN */
179 pos += 4;
180 put_unaligned_le32(metric, pos);
181 pos += 4;
182 if (action == MPATH_PREQ) {
183 *pos++ = 1; /* destination count */
184 *pos++ = target_flags;
185 memcpy(pos, target, ETH_ALEN);
186 pos += ETH_ALEN;
187 put_unaligned_le32(target_sn, pos);
188 pos += 4;
189 } else if (action == MPATH_PREP) {
190 memcpy(pos, orig_addr, ETH_ALEN);
191 pos += ETH_ALEN;
192 put_unaligned_le32(orig_sn, pos);
193 pos += 4;
194 }
195
196 ieee80211_tx_skb(sdata, skb);
197 return 0;
198 }
199
200
201 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
202 * headroom in case the frame is encrypted. */
203 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
204 struct sk_buff *skb)
205 {
206 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
207 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
208
209 skb_reset_mac_header(skb);
210 skb_reset_network_header(skb);
211 skb_reset_transport_header(skb);
212
213 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
214 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
215 skb->priority = 7;
216
217 info->control.vif = &sdata->vif;
218 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
219 ieee80211_set_qos_hdr(sdata, skb);
220 ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
221 }
222
223 /**
224 * mesh_path_error_tx - Sends a PERR mesh management frame
225 *
226 * @ttl: allowed remaining hops
227 * @target: broken destination
228 * @target_sn: SN of the broken destination
229 * @target_rcode: reason code for this PERR
230 * @ra: node this frame is addressed to
231 * @sdata: local mesh subif
232 *
233 * Note: This function may be called with driver locks taken that the driver
234 * also acquires in the TX path. To avoid a deadlock we don't transmit the
235 * frame directly but add it to the pending queue instead.
236 */
237 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
238 u8 ttl, const u8 *target, u32 target_sn,
239 u16 target_rcode, const u8 *ra)
240 {
241 struct ieee80211_local *local = sdata->local;
242 struct sk_buff *skb;
243 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
244 struct ieee80211_mgmt *mgmt;
245 u8 *pos, ie_len;
246 int hdr_len = offsetofend(struct ieee80211_mgmt,
247 u.action.u.mesh_action);
248
249 if (time_before(jiffies, ifmsh->next_perr))
250 return -EAGAIN;
251
252 skb = dev_alloc_skb(local->tx_headroom +
253 sdata->encrypt_headroom +
254 IEEE80211_ENCRYPT_TAILROOM +
255 hdr_len +
256 2 + 15 /* PERR IE */);
257 if (!skb)
258 return -1;
259 skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
260 mgmt = skb_put_zero(skb, hdr_len);
261 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
262 IEEE80211_STYPE_ACTION);
263
264 memcpy(mgmt->da, ra, ETH_ALEN);
265 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
266 /* BSSID == SA */
267 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
268 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
269 mgmt->u.action.u.mesh_action.action_code =
270 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
271 ie_len = 15;
272 pos = skb_put(skb, 2 + ie_len);
273 *pos++ = WLAN_EID_PERR;
274 *pos++ = ie_len;
275 /* ttl */
276 *pos++ = ttl;
277 /* number of destinations */
278 *pos++ = 1;
279 /* Flags field has AE bit only as defined in
280 * sec 8.4.2.117 IEEE802.11-2012
281 */
282 *pos = 0;
283 pos++;
284 memcpy(pos, target, ETH_ALEN);
285 pos += ETH_ALEN;
286 put_unaligned_le32(target_sn, pos);
287 pos += 4;
288 put_unaligned_le16(target_rcode, pos);
289
290 /* see note in function header */
291 prepare_frame_for_deferred_tx(sdata, skb);
292 ifmsh->next_perr = TU_TO_EXP_TIME(
293 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
294 ieee80211_add_pending_skb(local, skb);
295 return 0;
296 }
297
298 void ieee80211s_update_metric(struct ieee80211_local *local,
299 struct sta_info *sta,
300 struct ieee80211_tx_status *st)
301 {
302 struct ieee80211_tx_info *txinfo = st->info;
303 int failed;
304 struct rate_info rinfo;
305
306 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
307
308 /* moving average, scaled to 100.
309 * feed failure as 100 and success as 0
310 */
311 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
312 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
313 LINK_FAIL_THRESH)
314 mesh_plink_broken(sta);
315
316 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
317 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg,
318 cfg80211_calculate_bitrate(&rinfo));
319 }
320
321 static u32 airtime_link_metric_get(struct ieee80211_local *local,
322 struct sta_info *sta)
323 {
324 /* This should be adjusted for each device */
325 int device_constant = 1 << ARITH_SHIFT;
326 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
327 int s_unit = 1 << ARITH_SHIFT;
328 int rate, err;
329 u32 tx_time, estimated_retx;
330 u64 result;
331 unsigned long fail_avg =
332 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
333
334 /* Try to get rate based on HW/SW RC algorithm.
335 * Rate is returned in units of Kbps, correct this
336 * to comply with airtime calculation units
337 * Round up in case we get rate < 100Kbps
338 */
339 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
340
341 if (rate) {
342 err = 0;
343 } else {
344 if (fail_avg > LINK_FAIL_THRESH)
345 return MAX_METRIC;
346
347 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg);
348 if (WARN_ON(!rate))
349 return MAX_METRIC;
350
351 err = (fail_avg << ARITH_SHIFT) / 100;
352 }
353
354 /* bitrate is in units of 100 Kbps, while we need rate in units of
355 * 1Mbps. This will be corrected on tx_time computation.
356 */
357 tx_time = (device_constant + 10 * test_frame_len / rate);
358 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
359 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
360 return (u32)result;
361 }
362
363 /**
364 * hwmp_route_info_get - Update routing info to originator and transmitter
365 *
366 * @sdata: local mesh subif
367 * @mgmt: mesh management frame
368 * @hwmp_ie: hwmp information element (PREP or PREQ)
369 * @action: type of hwmp ie
370 *
371 * This function updates the path routing information to the originator and the
372 * transmitter of a HWMP PREQ or PREP frame.
373 *
374 * Returns: metric to frame originator or 0 if the frame should not be further
375 * processed
376 *
377 * Notes: this function is the only place (besides user-provided info) where
378 * path routing information is updated.
379 */
380 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
381 struct ieee80211_mgmt *mgmt,
382 const u8 *hwmp_ie, enum mpath_frame_type action)
383 {
384 struct ieee80211_local *local = sdata->local;
385 struct mesh_path *mpath;
386 struct sta_info *sta;
387 bool fresh_info;
388 const u8 *orig_addr, *ta;
389 u32 orig_sn, orig_metric;
390 unsigned long orig_lifetime, exp_time;
391 u32 last_hop_metric, new_metric;
392 bool process = true;
393 u8 hopcount;
394
395 rcu_read_lock();
396 sta = sta_info_get(sdata, mgmt->sa);
397 if (!sta) {
398 rcu_read_unlock();
399 return 0;
400 }
401
402 last_hop_metric = airtime_link_metric_get(local, sta);
403 /* Update and check originator routing info */
404 fresh_info = true;
405
406 switch (action) {
407 case MPATH_PREQ:
408 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
409 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
410 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
411 orig_metric = PREQ_IE_METRIC(hwmp_ie);
412 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
413 break;
414 case MPATH_PREP:
415 /* Originator here refers to the MP that was the target in the
416 * Path Request. We divert from the nomenclature in the draft
417 * so that we can easily use a single function to gather path
418 * information from both PREQ and PREP frames.
419 */
420 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
421 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
422 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
423 orig_metric = PREP_IE_METRIC(hwmp_ie);
424 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
425 break;
426 default:
427 rcu_read_unlock();
428 return 0;
429 }
430 new_metric = orig_metric + last_hop_metric;
431 if (new_metric < orig_metric)
432 new_metric = MAX_METRIC;
433 exp_time = TU_TO_EXP_TIME(orig_lifetime);
434
435 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
436 /* This MP is the originator, we are not interested in this
437 * frame, except for updating transmitter's path info.
438 */
439 process = false;
440 fresh_info = false;
441 } else {
442 mpath = mesh_path_lookup(sdata, orig_addr);
443 if (mpath) {
444 spin_lock_bh(&mpath->state_lock);
445 if (mpath->flags & MESH_PATH_FIXED)
446 fresh_info = false;
447 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
448 (mpath->flags & MESH_PATH_SN_VALID)) {
449 if (SN_GT(mpath->sn, orig_sn) ||
450 (mpath->sn == orig_sn &&
451 (rcu_access_pointer(mpath->next_hop) !=
452 sta ?
453 mult_frac(new_metric, 10, 9) :
454 new_metric) >= mpath->metric)) {
455 process = false;
456 fresh_info = false;
457 }
458 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
459 bool have_sn, newer_sn, bounced;
460
461 have_sn = mpath->flags & MESH_PATH_SN_VALID;
462 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
463 bounced = have_sn &&
464 (SN_DELTA(orig_sn, mpath->sn) >
465 MAX_SANE_SN_DELTA);
466
467 if (!have_sn || newer_sn) {
468 /* if SN is newer than what we had
469 * then we can take it */;
470 } else if (bounced) {
471 /* if SN is way different than what
472 * we had then assume the other side
473 * rebooted or restarted */;
474 } else {
475 process = false;
476 fresh_info = false;
477 }
478 }
479 } else {
480 mpath = mesh_path_add(sdata, orig_addr);
481 if (IS_ERR(mpath)) {
482 rcu_read_unlock();
483 return 0;
484 }
485 spin_lock_bh(&mpath->state_lock);
486 }
487
488 if (fresh_info) {
489 if (rcu_access_pointer(mpath->next_hop) != sta)
490 mpath->path_change_count++;
491 mesh_path_assign_nexthop(mpath, sta);
492 mpath->flags |= MESH_PATH_SN_VALID;
493 mpath->metric = new_metric;
494 mpath->sn = orig_sn;
495 mpath->exp_time = time_after(mpath->exp_time, exp_time)
496 ? mpath->exp_time : exp_time;
497 mpath->hop_count = hopcount;
498 mesh_path_activate(mpath);
499 spin_unlock_bh(&mpath->state_lock);
500 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
501 /* init it at a low value - 0 start is tricky */
502 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
503 mesh_path_tx_pending(mpath);
504 /* draft says preq_id should be saved to, but there does
505 * not seem to be any use for it, skipping by now
506 */
507 } else
508 spin_unlock_bh(&mpath->state_lock);
509 }
510
511 /* Update and check transmitter routing info */
512 ta = mgmt->sa;
513 if (ether_addr_equal(orig_addr, ta))
514 fresh_info = false;
515 else {
516 fresh_info = true;
517
518 mpath = mesh_path_lookup(sdata, ta);
519 if (mpath) {
520 spin_lock_bh(&mpath->state_lock);
521 if ((mpath->flags & MESH_PATH_FIXED) ||
522 ((mpath->flags & MESH_PATH_ACTIVE) &&
523 ((rcu_access_pointer(mpath->next_hop) != sta ?
524 mult_frac(last_hop_metric, 10, 9) :
525 last_hop_metric) > mpath->metric)))
526 fresh_info = false;
527 } else {
528 mpath = mesh_path_add(sdata, ta);
529 if (IS_ERR(mpath)) {
530 rcu_read_unlock();
531 return 0;
532 }
533 spin_lock_bh(&mpath->state_lock);
534 }
535
536 if (fresh_info) {
537 if (rcu_access_pointer(mpath->next_hop) != sta)
538 mpath->path_change_count++;
539 mesh_path_assign_nexthop(mpath, sta);
540 mpath->metric = last_hop_metric;
541 mpath->exp_time = time_after(mpath->exp_time, exp_time)
542 ? mpath->exp_time : exp_time;
543 mpath->hop_count = 1;
544 mesh_path_activate(mpath);
545 spin_unlock_bh(&mpath->state_lock);
546 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
547 /* init it at a low value - 0 start is tricky */
548 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
549 mesh_path_tx_pending(mpath);
550 } else
551 spin_unlock_bh(&mpath->state_lock);
552 }
553
554 rcu_read_unlock();
555
556 return process ? new_metric : 0;
557 }
558
559 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
560 struct ieee80211_mgmt *mgmt,
561 const u8 *preq_elem, u32 orig_metric)
562 {
563 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
564 struct mesh_path *mpath = NULL;
565 const u8 *target_addr, *orig_addr;
566 const u8 *da;
567 u8 target_flags, ttl, flags;
568 u32 orig_sn, target_sn, lifetime, target_metric = 0;
569 bool reply = false;
570 bool forward = true;
571 bool root_is_gate;
572
573 /* Update target SN, if present */
574 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
575 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
576 target_sn = PREQ_IE_TARGET_SN(preq_elem);
577 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
578 target_flags = PREQ_IE_TARGET_F(preq_elem);
579 /* Proactive PREQ gate announcements */
580 flags = PREQ_IE_FLAGS(preq_elem);
581 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
582
583 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
584
585 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
586 mhwmp_dbg(sdata, "PREQ is for us\n");
587 forward = false;
588 reply = true;
589 target_metric = 0;
590
591 if (SN_GT(target_sn, ifmsh->sn))
592 ifmsh->sn = target_sn;
593
594 if (time_after(jiffies, ifmsh->last_sn_update +
595 net_traversal_jiffies(sdata)) ||
596 time_before(jiffies, ifmsh->last_sn_update)) {
597 ++ifmsh->sn;
598 ifmsh->last_sn_update = jiffies;
599 }
600 target_sn = ifmsh->sn;
601 } else if (is_broadcast_ether_addr(target_addr) &&
602 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
603 rcu_read_lock();
604 mpath = mesh_path_lookup(sdata, orig_addr);
605 if (mpath) {
606 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
607 reply = true;
608 target_addr = sdata->vif.addr;
609 target_sn = ++ifmsh->sn;
610 target_metric = 0;
611 ifmsh->last_sn_update = jiffies;
612 }
613 if (root_is_gate)
614 mesh_path_add_gate(mpath);
615 }
616 rcu_read_unlock();
617 } else {
618 rcu_read_lock();
619 mpath = mesh_path_lookup(sdata, target_addr);
620 if (mpath) {
621 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
622 SN_LT(mpath->sn, target_sn)) {
623 mpath->sn = target_sn;
624 mpath->flags |= MESH_PATH_SN_VALID;
625 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
626 (mpath->flags & MESH_PATH_ACTIVE)) {
627 reply = true;
628 target_metric = mpath->metric;
629 target_sn = mpath->sn;
630 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
631 target_flags |= IEEE80211_PREQ_TO_FLAG;
632 }
633 }
634 rcu_read_unlock();
635 }
636
637 if (reply) {
638 lifetime = PREQ_IE_LIFETIME(preq_elem);
639 ttl = ifmsh->mshcfg.element_ttl;
640 if (ttl != 0) {
641 mhwmp_dbg(sdata, "replying to the PREQ\n");
642 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
643 orig_sn, 0, target_addr,
644 target_sn, mgmt->sa, 0, ttl,
645 lifetime, target_metric, 0,
646 sdata);
647 } else {
648 ifmsh->mshstats.dropped_frames_ttl++;
649 }
650 }
651
652 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
653 u32 preq_id;
654 u8 hopcount;
655
656 ttl = PREQ_IE_TTL(preq_elem);
657 lifetime = PREQ_IE_LIFETIME(preq_elem);
658 if (ttl <= 1) {
659 ifmsh->mshstats.dropped_frames_ttl++;
660 return;
661 }
662 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
663 --ttl;
664 preq_id = PREQ_IE_PREQ_ID(preq_elem);
665 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
666 da = (mpath && mpath->is_root) ?
667 mpath->rann_snd_addr : broadcast_addr;
668
669 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
670 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
671 target_sn = PREQ_IE_TARGET_SN(preq_elem);
672 }
673
674 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
675 orig_sn, target_flags, target_addr,
676 target_sn, da, hopcount, ttl, lifetime,
677 orig_metric, preq_id, sdata);
678 if (!is_multicast_ether_addr(da))
679 ifmsh->mshstats.fwded_unicast++;
680 else
681 ifmsh->mshstats.fwded_mcast++;
682 ifmsh->mshstats.fwded_frames++;
683 }
684 }
685
686
687 static inline struct sta_info *
688 next_hop_deref_protected(struct mesh_path *mpath)
689 {
690 return rcu_dereference_protected(mpath->next_hop,
691 lockdep_is_held(&mpath->state_lock));
692 }
693
694
695 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
696 struct ieee80211_mgmt *mgmt,
697 const u8 *prep_elem, u32 metric)
698 {
699 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
700 struct mesh_path *mpath;
701 const u8 *target_addr, *orig_addr;
702 u8 ttl, hopcount, flags;
703 u8 next_hop[ETH_ALEN];
704 u32 target_sn, orig_sn, lifetime;
705
706 mhwmp_dbg(sdata, "received PREP from %pM\n",
707 PREP_IE_TARGET_ADDR(prep_elem));
708
709 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
710 if (ether_addr_equal(orig_addr, sdata->vif.addr))
711 /* destination, no forwarding required */
712 return;
713
714 if (!ifmsh->mshcfg.dot11MeshForwarding)
715 return;
716
717 ttl = PREP_IE_TTL(prep_elem);
718 if (ttl <= 1) {
719 sdata->u.mesh.mshstats.dropped_frames_ttl++;
720 return;
721 }
722
723 rcu_read_lock();
724 mpath = mesh_path_lookup(sdata, orig_addr);
725 if (mpath)
726 spin_lock_bh(&mpath->state_lock);
727 else
728 goto fail;
729 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
730 spin_unlock_bh(&mpath->state_lock);
731 goto fail;
732 }
733 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
734 spin_unlock_bh(&mpath->state_lock);
735 --ttl;
736 flags = PREP_IE_FLAGS(prep_elem);
737 lifetime = PREP_IE_LIFETIME(prep_elem);
738 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
739 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
740 target_sn = PREP_IE_TARGET_SN(prep_elem);
741 orig_sn = PREP_IE_ORIG_SN(prep_elem);
742
743 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
744 target_addr, target_sn, next_hop, hopcount,
745 ttl, lifetime, metric, 0, sdata);
746 rcu_read_unlock();
747
748 sdata->u.mesh.mshstats.fwded_unicast++;
749 sdata->u.mesh.mshstats.fwded_frames++;
750 return;
751
752 fail:
753 rcu_read_unlock();
754 sdata->u.mesh.mshstats.dropped_frames_no_route++;
755 }
756
757 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
758 struct ieee80211_mgmt *mgmt,
759 const u8 *perr_elem)
760 {
761 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
762 struct mesh_path *mpath;
763 u8 ttl;
764 const u8 *ta, *target_addr;
765 u32 target_sn;
766 u16 target_rcode;
767
768 ta = mgmt->sa;
769 ttl = PERR_IE_TTL(perr_elem);
770 if (ttl <= 1) {
771 ifmsh->mshstats.dropped_frames_ttl++;
772 return;
773 }
774 ttl--;
775 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
776 target_sn = PERR_IE_TARGET_SN(perr_elem);
777 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
778
779 rcu_read_lock();
780 mpath = mesh_path_lookup(sdata, target_addr);
781 if (mpath) {
782 struct sta_info *sta;
783
784 spin_lock_bh(&mpath->state_lock);
785 sta = next_hop_deref_protected(mpath);
786 if (mpath->flags & MESH_PATH_ACTIVE &&
787 ether_addr_equal(ta, sta->sta.addr) &&
788 !(mpath->flags & MESH_PATH_FIXED) &&
789 (!(mpath->flags & MESH_PATH_SN_VALID) ||
790 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
791 mpath->flags &= ~MESH_PATH_ACTIVE;
792 if (target_sn != 0)
793 mpath->sn = target_sn;
794 else
795 mpath->sn += 1;
796 spin_unlock_bh(&mpath->state_lock);
797 if (!ifmsh->mshcfg.dot11MeshForwarding)
798 goto endperr;
799 mesh_path_error_tx(sdata, ttl, target_addr,
800 target_sn, target_rcode,
801 broadcast_addr);
802 } else
803 spin_unlock_bh(&mpath->state_lock);
804 }
805 endperr:
806 rcu_read_unlock();
807 }
808
809 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
810 struct ieee80211_mgmt *mgmt,
811 const struct ieee80211_rann_ie *rann)
812 {
813 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
814 struct ieee80211_local *local = sdata->local;
815 struct sta_info *sta;
816 struct mesh_path *mpath;
817 u8 ttl, flags, hopcount;
818 const u8 *orig_addr;
819 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
820 bool root_is_gate;
821
822 ttl = rann->rann_ttl;
823 flags = rann->rann_flags;
824 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
825 orig_addr = rann->rann_addr;
826 orig_sn = le32_to_cpu(rann->rann_seq);
827 interval = le32_to_cpu(rann->rann_interval);
828 hopcount = rann->rann_hopcount;
829 hopcount++;
830 orig_metric = le32_to_cpu(rann->rann_metric);
831
832 /* Ignore our own RANNs */
833 if (ether_addr_equal(orig_addr, sdata->vif.addr))
834 return;
835
836 mhwmp_dbg(sdata,
837 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
838 orig_addr, mgmt->sa, root_is_gate);
839
840 rcu_read_lock();
841 sta = sta_info_get(sdata, mgmt->sa);
842 if (!sta) {
843 rcu_read_unlock();
844 return;
845 }
846
847 last_hop_metric = airtime_link_metric_get(local, sta);
848 new_metric = orig_metric + last_hop_metric;
849 if (new_metric < orig_metric)
850 new_metric = MAX_METRIC;
851
852 mpath = mesh_path_lookup(sdata, orig_addr);
853 if (!mpath) {
854 mpath = mesh_path_add(sdata, orig_addr);
855 if (IS_ERR(mpath)) {
856 rcu_read_unlock();
857 sdata->u.mesh.mshstats.dropped_frames_no_route++;
858 return;
859 }
860 }
861
862 if (!(SN_LT(mpath->sn, orig_sn)) &&
863 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
864 rcu_read_unlock();
865 return;
866 }
867
868 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
869 (time_after(jiffies, mpath->last_preq_to_root +
870 root_path_confirmation_jiffies(sdata)) ||
871 time_before(jiffies, mpath->last_preq_to_root))) &&
872 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
873 mhwmp_dbg(sdata,
874 "time to refresh root mpath %pM\n",
875 orig_addr);
876 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
877 mpath->last_preq_to_root = jiffies;
878 }
879
880 mpath->sn = orig_sn;
881 mpath->rann_metric = new_metric;
882 mpath->is_root = true;
883 /* Recording RANNs sender address to send individually
884 * addressed PREQs destined for root mesh STA */
885 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
886
887 if (root_is_gate)
888 mesh_path_add_gate(mpath);
889
890 if (ttl <= 1) {
891 ifmsh->mshstats.dropped_frames_ttl++;
892 rcu_read_unlock();
893 return;
894 }
895 ttl--;
896
897 if (ifmsh->mshcfg.dot11MeshForwarding) {
898 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
899 orig_sn, 0, NULL, 0, broadcast_addr,
900 hopcount, ttl, interval,
901 new_metric, 0, sdata);
902 }
903
904 rcu_read_unlock();
905 }
906
907
908 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
909 struct ieee80211_mgmt *mgmt, size_t len)
910 {
911 struct ieee802_11_elems elems;
912 size_t baselen;
913 u32 path_metric;
914 struct sta_info *sta;
915
916 /* need action_code */
917 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
918 return;
919
920 rcu_read_lock();
921 sta = sta_info_get(sdata, mgmt->sa);
922 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
923 rcu_read_unlock();
924 return;
925 }
926 rcu_read_unlock();
927
928 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
929 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
930 len - baselen, false, &elems, mgmt->bssid, NULL);
931
932 if (elems.preq) {
933 if (elems.preq_len != 37)
934 /* Right now we support just 1 destination and no AE */
935 return;
936 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
937 MPATH_PREQ);
938 if (path_metric)
939 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
940 path_metric);
941 }
942 if (elems.prep) {
943 if (elems.prep_len != 31)
944 /* Right now we support no AE */
945 return;
946 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
947 MPATH_PREP);
948 if (path_metric)
949 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
950 path_metric);
951 }
952 if (elems.perr) {
953 if (elems.perr_len != 15)
954 /* Right now we support only one destination per PERR */
955 return;
956 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
957 }
958 if (elems.rann)
959 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
960 }
961
962 /**
963 * mesh_queue_preq - queue a PREQ to a given destination
964 *
965 * @mpath: mesh path to discover
966 * @flags: special attributes of the PREQ to be sent
967 *
968 * Locking: the function must be called from within a rcu read lock block.
969 *
970 */
971 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
972 {
973 struct ieee80211_sub_if_data *sdata = mpath->sdata;
974 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
975 struct mesh_preq_queue *preq_node;
976
977 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
978 if (!preq_node) {
979 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
980 return;
981 }
982
983 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
984 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
985 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
986 kfree(preq_node);
987 if (printk_ratelimit())
988 mhwmp_dbg(sdata, "PREQ node queue full\n");
989 return;
990 }
991
992 spin_lock(&mpath->state_lock);
993 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
994 spin_unlock(&mpath->state_lock);
995 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
996 kfree(preq_node);
997 return;
998 }
999
1000 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1001 preq_node->flags = flags;
1002
1003 mpath->flags |= MESH_PATH_REQ_QUEUED;
1004 spin_unlock(&mpath->state_lock);
1005
1006 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1007 ++ifmsh->preq_queue_len;
1008 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1009
1010 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1011 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1012
1013 else if (time_before(jiffies, ifmsh->last_preq)) {
1014 /* avoid long wait if did not send preqs for a long time
1015 * and jiffies wrapped around
1016 */
1017 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1018 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1019 } else
1020 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1021 min_preq_int_jiff(sdata));
1022 }
1023
1024 /**
1025 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1026 *
1027 * @sdata: local mesh subif
1028 */
1029 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1030 {
1031 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1032 struct mesh_preq_queue *preq_node;
1033 struct mesh_path *mpath;
1034 u8 ttl, target_flags = 0;
1035 const u8 *da;
1036 u32 lifetime;
1037
1038 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1039 if (!ifmsh->preq_queue_len ||
1040 time_before(jiffies, ifmsh->last_preq +
1041 min_preq_int_jiff(sdata))) {
1042 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1043 return;
1044 }
1045
1046 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1047 struct mesh_preq_queue, list);
1048 list_del(&preq_node->list);
1049 --ifmsh->preq_queue_len;
1050 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1051
1052 rcu_read_lock();
1053 mpath = mesh_path_lookup(sdata, preq_node->dst);
1054 if (!mpath)
1055 goto enddiscovery;
1056
1057 spin_lock_bh(&mpath->state_lock);
1058 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1059 spin_unlock_bh(&mpath->state_lock);
1060 goto enddiscovery;
1061 }
1062 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1063 if (preq_node->flags & PREQ_Q_F_START) {
1064 if (mpath->flags & MESH_PATH_RESOLVING) {
1065 spin_unlock_bh(&mpath->state_lock);
1066 goto enddiscovery;
1067 } else {
1068 mpath->flags &= ~MESH_PATH_RESOLVED;
1069 mpath->flags |= MESH_PATH_RESOLVING;
1070 mpath->discovery_retries = 0;
1071 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1072 }
1073 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1074 mpath->flags & MESH_PATH_RESOLVED) {
1075 mpath->flags &= ~MESH_PATH_RESOLVING;
1076 spin_unlock_bh(&mpath->state_lock);
1077 goto enddiscovery;
1078 }
1079
1080 ifmsh->last_preq = jiffies;
1081
1082 if (time_after(jiffies, ifmsh->last_sn_update +
1083 net_traversal_jiffies(sdata)) ||
1084 time_before(jiffies, ifmsh->last_sn_update)) {
1085 ++ifmsh->sn;
1086 sdata->u.mesh.last_sn_update = jiffies;
1087 }
1088 lifetime = default_lifetime(sdata);
1089 ttl = sdata->u.mesh.mshcfg.element_ttl;
1090 if (ttl == 0) {
1091 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1092 spin_unlock_bh(&mpath->state_lock);
1093 goto enddiscovery;
1094 }
1095
1096 if (preq_node->flags & PREQ_Q_F_REFRESH)
1097 target_flags |= IEEE80211_PREQ_TO_FLAG;
1098 else
1099 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1100
1101 spin_unlock_bh(&mpath->state_lock);
1102 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1103 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1104 target_flags, mpath->dst, mpath->sn, da, 0,
1105 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1106 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1107
1108 enddiscovery:
1109 rcu_read_unlock();
1110 kfree(preq_node);
1111 }
1112
1113 /**
1114 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1115 *
1116 * @skb: 802.11 frame to be sent
1117 * @sdata: network subif the frame will be sent through
1118 *
1119 * Lookup next hop for given skb and start path discovery if no
1120 * forwarding information is found.
1121 *
1122 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1123 * skb is freeed here if no mpath could be allocated.
1124 */
1125 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1126 struct sk_buff *skb)
1127 {
1128 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1129 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1130 struct mesh_path *mpath;
1131 struct sk_buff *skb_to_free = NULL;
1132 u8 *target_addr = hdr->addr3;
1133 int err = 0;
1134
1135 /* Nulls are only sent to peers for PS and should be pre-addressed */
1136 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1137 return 0;
1138
1139 rcu_read_lock();
1140 err = mesh_nexthop_lookup(sdata, skb);
1141 if (!err)
1142 goto endlookup;
1143
1144 /* no nexthop found, start resolving */
1145 mpath = mesh_path_lookup(sdata, target_addr);
1146 if (!mpath) {
1147 mpath = mesh_path_add(sdata, target_addr);
1148 if (IS_ERR(mpath)) {
1149 mesh_path_discard_frame(sdata, skb);
1150 err = PTR_ERR(mpath);
1151 goto endlookup;
1152 }
1153 }
1154
1155 if (!(mpath->flags & MESH_PATH_RESOLVING))
1156 mesh_queue_preq(mpath, PREQ_Q_F_START);
1157
1158 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1159 skb_to_free = skb_dequeue(&mpath->frame_queue);
1160
1161 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1162 ieee80211_set_qos_hdr(sdata, skb);
1163 skb_queue_tail(&mpath->frame_queue, skb);
1164 err = -ENOENT;
1165 if (skb_to_free)
1166 mesh_path_discard_frame(sdata, skb_to_free);
1167
1168 endlookup:
1169 rcu_read_unlock();
1170 return err;
1171 }
1172
1173 /**
1174 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1175 * this function is considered "using" the associated mpath, so preempt a path
1176 * refresh if this mpath expires soon.
1177 *
1178 * @skb: 802.11 frame to be sent
1179 * @sdata: network subif the frame will be sent through
1180 *
1181 * Returns: 0 if the next hop was found. Nonzero otherwise.
1182 */
1183 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1184 struct sk_buff *skb)
1185 {
1186 struct mesh_path *mpath;
1187 struct sta_info *next_hop;
1188 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1189 u8 *target_addr = hdr->addr3;
1190 int err = -ENOENT;
1191
1192 rcu_read_lock();
1193 mpath = mesh_path_lookup(sdata, target_addr);
1194
1195 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1196 goto endlookup;
1197
1198 if (time_after(jiffies,
1199 mpath->exp_time -
1200 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1201 ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
1202 !(mpath->flags & MESH_PATH_RESOLVING) &&
1203 !(mpath->flags & MESH_PATH_FIXED))
1204 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1205
1206 next_hop = rcu_dereference(mpath->next_hop);
1207 if (next_hop) {
1208 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1209 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1210 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1211 err = 0;
1212 }
1213
1214 endlookup:
1215 rcu_read_unlock();
1216 return err;
1217 }
1218
1219 void mesh_path_timer(struct timer_list *t)
1220 {
1221 struct mesh_path *mpath = from_timer(mpath, t, timer);
1222 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1223 int ret;
1224
1225 if (sdata->local->quiescing)
1226 return;
1227
1228 spin_lock_bh(&mpath->state_lock);
1229 if (mpath->flags & MESH_PATH_RESOLVED ||
1230 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1231 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1232 spin_unlock_bh(&mpath->state_lock);
1233 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1234 ++mpath->discovery_retries;
1235 mpath->discovery_timeout *= 2;
1236 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1237 spin_unlock_bh(&mpath->state_lock);
1238 mesh_queue_preq(mpath, 0);
1239 } else {
1240 mpath->flags &= ~(MESH_PATH_RESOLVING |
1241 MESH_PATH_RESOLVED |
1242 MESH_PATH_REQ_QUEUED);
1243 mpath->exp_time = jiffies;
1244 spin_unlock_bh(&mpath->state_lock);
1245 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1246 ret = mesh_path_send_to_gates(mpath);
1247 if (ret)
1248 mhwmp_dbg(sdata, "no gate was reachable\n");
1249 } else
1250 mesh_path_flush_pending(mpath);
1251 }
1252 }
1253
1254 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1255 {
1256 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1257 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1258 u8 flags, target_flags = 0;
1259
1260 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1261 ? RANN_FLAG_IS_GATE : 0;
1262
1263 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1264 case IEEE80211_PROACTIVE_RANN:
1265 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1266 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1267 0, ifmsh->mshcfg.element_ttl,
1268 interval, 0, 0, sdata);
1269 break;
1270 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1271 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1272 /* fall through */
1273 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1274 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1275 target_flags |= IEEE80211_PREQ_TO_FLAG |
1276 IEEE80211_PREQ_USN_FLAG;
1277 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1278 ++ifmsh->sn, target_flags,
1279 (u8 *) broadcast_addr, 0, broadcast_addr,
1280 0, ifmsh->mshcfg.element_ttl, interval,
1281 0, ifmsh->preq_id++, sdata);
1282 break;
1283 default:
1284 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1285 return;
1286 }
1287 }
Linux with added FPC-III support