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Merge tag 'pci-v6.16-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
[linux-2.6-block.git] / net / mac80211 / mesh_hwmp.c
... / ...
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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Copyright (C) 2019, 2021-2023 Intel Corporation
5 * Author: Luis Carlos Cobo <luisca@cozybit.com>
6 */
7
8#include <linux/slab.h>
9#include <linux/etherdevice.h>
10#include <linux/unaligned.h>
11#include "wme.h"
12#include "mesh.h"
13
14#define TEST_FRAME_LEN 8192
15#define MAX_METRIC 0xffffffff
16#define ARITH_SHIFT 8
17#define LINK_FAIL_THRESH 95
18
19#define MAX_PREQ_QUEUE_LEN 64
20
21static void mesh_queue_preq(struct mesh_path *, u8);
22
23static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
24{
25 if (ae)
26 offset += 6;
27 return get_unaligned_le32(preq_elem + offset);
28}
29
30static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
31{
32 if (ae)
33 offset += 6;
34 return get_unaligned_le16(preq_elem + offset);
35}
36
37/* HWMP IE processing macros */
38#define AE_F (1<<6)
39#define AE_F_SET(x) (*x & AE_F)
40#define PREQ_IE_FLAGS(x) (*(x))
41#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
42#define PREQ_IE_TTL(x) (*(x + 2))
43#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
44#define PREQ_IE_ORIG_ADDR(x) (x + 7)
45#define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
46#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
47#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
48#define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
49#define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
50#define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
51
52
53#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
54#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
55#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
56#define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
57#define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
58#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
59#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
60#define PREP_IE_TARGET_ADDR(x) (x + 3)
61#define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
62
63#define PERR_IE_TTL(x) (*(x))
64#define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
65#define PERR_IE_TARGET_ADDR(x) (x + 3)
66#define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
67#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
68
69#define MSEC_TO_TU(x) (x*1000/1024)
70#define SN_GT(x, y) ((s32)(y - x) < 0)
71#define SN_LT(x, y) ((s32)(x - y) < 0)
72#define MAX_SANE_SN_DELTA 32
73
74static inline u32 SN_DELTA(u32 x, u32 y)
75{
76 return x >= y ? x - y : y - x;
77}
78
79#define net_traversal_jiffies(s) \
80 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
81#define default_lifetime(s) \
82 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
83#define min_preq_int_jiff(s) \
84 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
85#define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
86#define disc_timeout_jiff(s) \
87 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
88#define root_path_confirmation_jiffies(s) \
89 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
90
91enum mpath_frame_type {
92 MPATH_PREQ = 0,
93 MPATH_PREP,
94 MPATH_PERR,
95 MPATH_RANN
96};
97
98static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
99
100static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
101 const u8 *orig_addr, u32 orig_sn,
102 u8 target_flags, const u8 *target,
103 u32 target_sn, const u8 *da,
104 u8 hop_count, u8 ttl,
105 u32 lifetime, u32 metric, u32 preq_id,
106 struct ieee80211_sub_if_data *sdata)
107{
108 struct ieee80211_local *local = sdata->local;
109 struct sk_buff *skb;
110 struct ieee80211_mgmt *mgmt;
111 u8 *pos, ie_len;
112 int hdr_len = offsetofend(struct ieee80211_mgmt,
113 u.action.u.mesh_action);
114
115 skb = dev_alloc_skb(local->tx_headroom +
116 hdr_len +
117 2 + 37); /* max HWMP IE */
118 if (!skb)
119 return -1;
120 skb_reserve(skb, local->tx_headroom);
121 mgmt = skb_put_zero(skb, hdr_len);
122 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
123 IEEE80211_STYPE_ACTION);
124
125 memcpy(mgmt->da, da, ETH_ALEN);
126 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
127 /* BSSID == SA */
128 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
129 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
130 mgmt->u.action.u.mesh_action.action_code =
131 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
132
133 switch (action) {
134 case MPATH_PREQ:
135 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
136 ie_len = 37;
137 pos = skb_put(skb, 2 + ie_len);
138 *pos++ = WLAN_EID_PREQ;
139 break;
140 case MPATH_PREP:
141 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
142 ie_len = 31;
143 pos = skb_put(skb, 2 + ie_len);
144 *pos++ = WLAN_EID_PREP;
145 break;
146 case MPATH_RANN:
147 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
148 ie_len = sizeof(struct ieee80211_rann_ie);
149 pos = skb_put(skb, 2 + ie_len);
150 *pos++ = WLAN_EID_RANN;
151 break;
152 default:
153 kfree_skb(skb);
154 return -EOPNOTSUPP;
155 }
156 *pos++ = ie_len;
157 *pos++ = flags;
158 *pos++ = hop_count;
159 *pos++ = ttl;
160 if (action == MPATH_PREP) {
161 memcpy(pos, target, ETH_ALEN);
162 pos += ETH_ALEN;
163 put_unaligned_le32(target_sn, pos);
164 pos += 4;
165 } else {
166 if (action == MPATH_PREQ) {
167 put_unaligned_le32(preq_id, pos);
168 pos += 4;
169 }
170 memcpy(pos, orig_addr, ETH_ALEN);
171 pos += ETH_ALEN;
172 put_unaligned_le32(orig_sn, pos);
173 pos += 4;
174 }
175 put_unaligned_le32(lifetime, pos); /* interval for RANN */
176 pos += 4;
177 put_unaligned_le32(metric, pos);
178 pos += 4;
179 if (action == MPATH_PREQ) {
180 *pos++ = 1; /* destination count */
181 *pos++ = target_flags;
182 memcpy(pos, target, ETH_ALEN);
183 pos += ETH_ALEN;
184 put_unaligned_le32(target_sn, pos);
185 pos += 4;
186 } else if (action == MPATH_PREP) {
187 memcpy(pos, orig_addr, ETH_ALEN);
188 pos += ETH_ALEN;
189 put_unaligned_le32(orig_sn, pos);
190 pos += 4;
191 }
192
193 ieee80211_tx_skb(sdata, skb);
194 return 0;
195}
196
197
198/* Headroom is not adjusted. Caller should ensure that skb has sufficient
199 * headroom in case the frame is encrypted. */
200static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
201 struct sk_buff *skb)
202{
203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
204 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
205
206 skb_reset_mac_header(skb);
207 skb_reset_network_header(skb);
208 skb_reset_transport_header(skb);
209
210 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
211 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
212 skb->priority = 7;
213
214 info->control.vif = &sdata->vif;
215 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
216 ieee80211_set_qos_hdr(sdata, skb);
217 ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
218}
219
220/**
221 * mesh_path_error_tx - Sends a PERR mesh management frame
222 *
223 * @sdata: local mesh subif
224 * @ttl: allowed remaining hops
225 * @target: broken destination
226 * @target_sn: SN of the broken destination
227 * @target_rcode: reason code for this PERR
228 * @ra: node this frame is addressed to
229 *
230 * Note: This function may be called with driver locks taken that the driver
231 * also acquires in the TX path. To avoid a deadlock we don't transmit the
232 * frame directly but add it to the pending queue instead.
233 *
234 * Returns: 0 on success
235 */
236int 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 IEEE80211_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 + IEEE80211_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
297void ieee80211s_update_metric(struct ieee80211_local *local,
298 struct sta_info *sta,
299 struct ieee80211_tx_status *st)
300{
301 struct ieee80211_tx_info *txinfo = st->info;
302 int failed;
303 struct rate_info rinfo;
304
305 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
306
307 /* moving average, scaled to 100.
308 * feed failure as 100 and success as 0
309 */
310 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
311 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
312 LINK_FAIL_THRESH)
313 mesh_plink_broken(sta);
314
315 /* use rate info set by the driver directly if present */
316 if (st->n_rates)
317 rinfo = sta->deflink.tx_stats.last_rate_info;
318 else
319 sta_set_rate_info_tx(sta, &sta->deflink.tx_stats.last_rate, &rinfo);
320
321 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg,
322 cfg80211_calculate_bitrate(&rinfo));
323}
324
325u32 airtime_link_metric_get(struct ieee80211_local *local,
326 struct sta_info *sta)
327{
328 /* This should be adjusted for each device */
329 int device_constant = 1 << ARITH_SHIFT;
330 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
331 int s_unit = 1 << ARITH_SHIFT;
332 int rate, err;
333 u32 tx_time, estimated_retx;
334 u64 result;
335 unsigned long fail_avg =
336 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
337
338 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB)
339 return MAX_METRIC;
340
341 /* Try to get rate based on HW/SW RC algorithm.
342 * Rate is returned in units of Kbps, correct this
343 * to comply with airtime calculation units
344 * Round up in case we get rate < 100Kbps
345 */
346 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
347
348 if (rate) {
349 err = 0;
350 } else {
351 if (fail_avg > LINK_FAIL_THRESH)
352 return MAX_METRIC;
353
354 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg);
355 if (WARN_ON(!rate))
356 return MAX_METRIC;
357
358 err = (fail_avg << ARITH_SHIFT) / 100;
359 }
360
361 /* bitrate is in units of 100 Kbps, while we need rate in units of
362 * 1Mbps. This will be corrected on tx_time computation.
363 */
364 tx_time = (device_constant + 10 * test_frame_len / rate);
365 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
366 result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
367 return (u32)result;
368}
369
370/* Check that the first metric is at least 10% better than the second one */
371static bool is_metric_better(u32 x, u32 y)
372{
373 return (x < y) && (x < (y - x / 10));
374}
375
376/**
377 * hwmp_route_info_get - Update routing info to originator and transmitter
378 *
379 * @sdata: local mesh subif
380 * @mgmt: mesh management frame
381 * @hwmp_ie: hwmp information element (PREP or PREQ)
382 * @action: type of hwmp ie
383 *
384 * This function updates the path routing information to the originator and the
385 * transmitter of a HWMP PREQ or PREP frame.
386 *
387 * Returns: metric to frame originator or 0 if the frame should not be further
388 * processed
389 *
390 * Notes: this function is the only place (besides user-provided info) where
391 * path routing information is updated.
392 */
393static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
394 struct ieee80211_mgmt *mgmt,
395 const u8 *hwmp_ie, enum mpath_frame_type action)
396{
397 struct ieee80211_local *local = sdata->local;
398 struct mesh_path *mpath;
399 struct sta_info *sta;
400 bool fresh_info;
401 const u8 *orig_addr, *ta;
402 u32 orig_sn, orig_metric;
403 unsigned long orig_lifetime, exp_time;
404 u32 last_hop_metric, new_metric;
405 bool flush_mpath = false;
406 bool process = true;
407 u8 hopcount;
408
409 rcu_read_lock();
410 sta = sta_info_get(sdata, mgmt->sa);
411 if (!sta) {
412 rcu_read_unlock();
413 return 0;
414 }
415
416 last_hop_metric = airtime_link_metric_get(local, sta);
417 /* Update and check originator routing info */
418 fresh_info = true;
419
420 switch (action) {
421 case MPATH_PREQ:
422 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
423 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
424 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
425 orig_metric = PREQ_IE_METRIC(hwmp_ie);
426 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
427 break;
428 case MPATH_PREP:
429 /* Originator here refers to the MP that was the target in the
430 * Path Request. We divert from the nomenclature in the draft
431 * so that we can easily use a single function to gather path
432 * information from both PREQ and PREP frames.
433 */
434 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
435 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
436 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
437 orig_metric = PREP_IE_METRIC(hwmp_ie);
438 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
439 break;
440 default:
441 rcu_read_unlock();
442 return 0;
443 }
444 new_metric = orig_metric + last_hop_metric;
445 if (new_metric < orig_metric)
446 new_metric = MAX_METRIC;
447 exp_time = TU_TO_EXP_TIME(orig_lifetime);
448
449 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
450 /* This MP is the originator, we are not interested in this
451 * frame, except for updating transmitter's path info.
452 */
453 process = false;
454 fresh_info = false;
455 } else {
456 mpath = mesh_path_lookup(sdata, orig_addr);
457 if (mpath) {
458 spin_lock_bh(&mpath->state_lock);
459 if (mpath->flags & MESH_PATH_FIXED)
460 fresh_info = false;
461 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
462 (mpath->flags & MESH_PATH_SN_VALID)) {
463 if (SN_GT(mpath->sn, orig_sn) ||
464 (mpath->sn == orig_sn &&
465 (rcu_access_pointer(mpath->next_hop) !=
466 sta ?
467 !is_metric_better(new_metric, mpath->metric) :
468 new_metric >= mpath->metric))) {
469 process = false;
470 fresh_info = false;
471 }
472 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
473 bool have_sn, newer_sn, bounced;
474
475 have_sn = mpath->flags & MESH_PATH_SN_VALID;
476 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
477 bounced = have_sn &&
478 (SN_DELTA(orig_sn, mpath->sn) >
479 MAX_SANE_SN_DELTA);
480
481 if (!have_sn || newer_sn) {
482 /* if SN is newer than what we had
483 * then we can take it */;
484 } else if (bounced) {
485 /* if SN is way different than what
486 * we had then assume the other side
487 * rebooted or restarted */;
488 } else {
489 process = false;
490 fresh_info = false;
491 }
492 }
493 } else {
494 mpath = mesh_path_add(sdata, orig_addr);
495 if (IS_ERR(mpath)) {
496 rcu_read_unlock();
497 return 0;
498 }
499 spin_lock_bh(&mpath->state_lock);
500 }
501
502 if (fresh_info) {
503 if (rcu_access_pointer(mpath->next_hop) != sta) {
504 mpath->path_change_count++;
505 flush_mpath = true;
506 }
507 mesh_path_assign_nexthop(mpath, sta);
508 mpath->flags |= MESH_PATH_SN_VALID;
509 mpath->metric = new_metric;
510 mpath->sn = orig_sn;
511 mpath->exp_time = time_after(mpath->exp_time, exp_time)
512 ? mpath->exp_time : exp_time;
513 mpath->hop_count = hopcount;
514 mesh_path_activate(mpath);
515 spin_unlock_bh(&mpath->state_lock);
516 if (flush_mpath)
517 mesh_fast_tx_flush_mpath(mpath);
518 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
519 /* init it at a low value - 0 start is tricky */
520 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
521 mesh_path_tx_pending(mpath);
522 /* draft says preq_id should be saved to, but there does
523 * not seem to be any use for it, skipping by now
524 */
525 } else
526 spin_unlock_bh(&mpath->state_lock);
527 }
528
529 /* Update and check transmitter routing info */
530 ta = mgmt->sa;
531 if (ether_addr_equal(orig_addr, ta))
532 fresh_info = false;
533 else {
534 fresh_info = true;
535
536 mpath = mesh_path_lookup(sdata, ta);
537 if (mpath) {
538 spin_lock_bh(&mpath->state_lock);
539 if ((mpath->flags & MESH_PATH_FIXED) ||
540 ((mpath->flags & MESH_PATH_ACTIVE) &&
541 ((rcu_access_pointer(mpath->next_hop) != sta ?
542 !is_metric_better(last_hop_metric, mpath->metric) :
543 last_hop_metric > mpath->metric))))
544 fresh_info = false;
545 } else {
546 mpath = mesh_path_add(sdata, ta);
547 if (IS_ERR(mpath)) {
548 rcu_read_unlock();
549 return 0;
550 }
551 spin_lock_bh(&mpath->state_lock);
552 }
553
554 if (fresh_info) {
555 if (rcu_access_pointer(mpath->next_hop) != sta) {
556 mpath->path_change_count++;
557 flush_mpath = true;
558 }
559 mesh_path_assign_nexthop(mpath, sta);
560 mpath->metric = last_hop_metric;
561 mpath->exp_time = time_after(mpath->exp_time, exp_time)
562 ? mpath->exp_time : exp_time;
563 mpath->hop_count = 1;
564 mesh_path_activate(mpath);
565 spin_unlock_bh(&mpath->state_lock);
566 if (flush_mpath)
567 mesh_fast_tx_flush_mpath(mpath);
568 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
569 /* init it at a low value - 0 start is tricky */
570 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
571 mesh_path_tx_pending(mpath);
572 } else
573 spin_unlock_bh(&mpath->state_lock);
574 }
575
576 rcu_read_unlock();
577
578 return process ? new_metric : 0;
579}
580
581static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
582 struct ieee80211_mgmt *mgmt,
583 const u8 *preq_elem, u32 orig_metric)
584{
585 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
586 struct mesh_path *mpath = NULL;
587 const u8 *target_addr, *orig_addr;
588 const u8 *da;
589 u8 target_flags, ttl, flags;
590 u32 orig_sn, target_sn, lifetime, target_metric = 0;
591 bool reply = false;
592 bool forward = true;
593 bool root_is_gate;
594
595 /* Update target SN, if present */
596 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
597 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
598 target_sn = PREQ_IE_TARGET_SN(preq_elem);
599 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
600 target_flags = PREQ_IE_TARGET_F(preq_elem);
601 /* Proactive PREQ gate announcements */
602 flags = PREQ_IE_FLAGS(preq_elem);
603 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
604
605 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
606
607 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
608 mhwmp_dbg(sdata, "PREQ is for us\n");
609 forward = false;
610 reply = true;
611 target_metric = 0;
612
613 if (SN_GT(target_sn, ifmsh->sn))
614 ifmsh->sn = target_sn;
615
616 if (time_after(jiffies, ifmsh->last_sn_update +
617 net_traversal_jiffies(sdata)) ||
618 time_before(jiffies, ifmsh->last_sn_update)) {
619 ++ifmsh->sn;
620 ifmsh->last_sn_update = jiffies;
621 }
622 target_sn = ifmsh->sn;
623 } else if (is_broadcast_ether_addr(target_addr) &&
624 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
625 rcu_read_lock();
626 mpath = mesh_path_lookup(sdata, orig_addr);
627 if (mpath) {
628 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
629 reply = true;
630 target_addr = sdata->vif.addr;
631 target_sn = ++ifmsh->sn;
632 target_metric = 0;
633 ifmsh->last_sn_update = jiffies;
634 }
635 if (root_is_gate)
636 mesh_path_add_gate(mpath);
637 }
638 rcu_read_unlock();
639 } else if (ifmsh->mshcfg.dot11MeshForwarding) {
640 rcu_read_lock();
641 mpath = mesh_path_lookup(sdata, target_addr);
642 if (mpath) {
643 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
644 SN_LT(mpath->sn, target_sn)) {
645 mpath->sn = target_sn;
646 mpath->flags |= MESH_PATH_SN_VALID;
647 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
648 (mpath->flags & MESH_PATH_ACTIVE)) {
649 reply = true;
650 target_metric = mpath->metric;
651 target_sn = mpath->sn;
652 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
653 target_flags |= IEEE80211_PREQ_TO_FLAG;
654 }
655 }
656 rcu_read_unlock();
657 } else {
658 forward = false;
659 }
660
661 if (reply) {
662 lifetime = PREQ_IE_LIFETIME(preq_elem);
663 ttl = ifmsh->mshcfg.element_ttl;
664 if (ttl != 0) {
665 mhwmp_dbg(sdata, "replying to the PREQ\n");
666 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
667 orig_sn, 0, target_addr,
668 target_sn, mgmt->sa, 0, ttl,
669 lifetime, target_metric, 0,
670 sdata);
671 } else {
672 ifmsh->mshstats.dropped_frames_ttl++;
673 }
674 }
675
676 if (forward) {
677 u32 preq_id;
678 u8 hopcount;
679
680 ttl = PREQ_IE_TTL(preq_elem);
681 lifetime = PREQ_IE_LIFETIME(preq_elem);
682 if (ttl <= 1) {
683 ifmsh->mshstats.dropped_frames_ttl++;
684 return;
685 }
686 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
687 --ttl;
688 preq_id = PREQ_IE_PREQ_ID(preq_elem);
689 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
690 da = (mpath && mpath->is_root) ?
691 mpath->rann_snd_addr : broadcast_addr;
692
693 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
694 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
695 target_sn = PREQ_IE_TARGET_SN(preq_elem);
696 }
697
698 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
699 orig_sn, target_flags, target_addr,
700 target_sn, da, hopcount, ttl, lifetime,
701 orig_metric, preq_id, sdata);
702 if (!is_multicast_ether_addr(da))
703 ifmsh->mshstats.fwded_unicast++;
704 else
705 ifmsh->mshstats.fwded_mcast++;
706 ifmsh->mshstats.fwded_frames++;
707 }
708}
709
710
711static inline struct sta_info *
712next_hop_deref_protected(struct mesh_path *mpath)
713{
714 return rcu_dereference_protected(mpath->next_hop,
715 lockdep_is_held(&mpath->state_lock));
716}
717
718
719static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
720 struct ieee80211_mgmt *mgmt,
721 const u8 *prep_elem, u32 metric)
722{
723 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
724 struct mesh_path *mpath;
725 const u8 *target_addr, *orig_addr;
726 u8 ttl, hopcount, flags;
727 u8 next_hop[ETH_ALEN];
728 u32 target_sn, orig_sn, lifetime;
729
730 mhwmp_dbg(sdata, "received PREP from %pM\n",
731 PREP_IE_TARGET_ADDR(prep_elem));
732
733 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
734 if (ether_addr_equal(orig_addr, sdata->vif.addr))
735 /* destination, no forwarding required */
736 return;
737
738 if (!ifmsh->mshcfg.dot11MeshForwarding)
739 return;
740
741 ttl = PREP_IE_TTL(prep_elem);
742 if (ttl <= 1) {
743 sdata->u.mesh.mshstats.dropped_frames_ttl++;
744 return;
745 }
746
747 rcu_read_lock();
748 mpath = mesh_path_lookup(sdata, orig_addr);
749 if (mpath)
750 spin_lock_bh(&mpath->state_lock);
751 else
752 goto fail;
753 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
754 spin_unlock_bh(&mpath->state_lock);
755 goto fail;
756 }
757 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
758 spin_unlock_bh(&mpath->state_lock);
759 --ttl;
760 flags = PREP_IE_FLAGS(prep_elem);
761 lifetime = PREP_IE_LIFETIME(prep_elem);
762 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
763 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
764 target_sn = PREP_IE_TARGET_SN(prep_elem);
765 orig_sn = PREP_IE_ORIG_SN(prep_elem);
766
767 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
768 target_addr, target_sn, next_hop, hopcount,
769 ttl, lifetime, metric, 0, sdata);
770 rcu_read_unlock();
771
772 sdata->u.mesh.mshstats.fwded_unicast++;
773 sdata->u.mesh.mshstats.fwded_frames++;
774 return;
775
776fail:
777 rcu_read_unlock();
778 sdata->u.mesh.mshstats.dropped_frames_no_route++;
779}
780
781static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
782 struct ieee80211_mgmt *mgmt,
783 const u8 *perr_elem)
784{
785 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
786 struct mesh_path *mpath;
787 u8 ttl;
788 const u8 *ta, *target_addr;
789 u32 target_sn;
790 u16 target_rcode;
791
792 ta = mgmt->sa;
793 ttl = PERR_IE_TTL(perr_elem);
794 if (ttl <= 1) {
795 ifmsh->mshstats.dropped_frames_ttl++;
796 return;
797 }
798 ttl--;
799 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
800 target_sn = PERR_IE_TARGET_SN(perr_elem);
801 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
802
803 rcu_read_lock();
804 mpath = mesh_path_lookup(sdata, target_addr);
805 if (mpath) {
806 struct sta_info *sta;
807
808 spin_lock_bh(&mpath->state_lock);
809 sta = next_hop_deref_protected(mpath);
810 if (mpath->flags & MESH_PATH_ACTIVE &&
811 ether_addr_equal(ta, sta->sta.addr) &&
812 !(mpath->flags & MESH_PATH_FIXED) &&
813 (!(mpath->flags & MESH_PATH_SN_VALID) ||
814 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
815 mpath->flags &= ~MESH_PATH_ACTIVE;
816 if (target_sn != 0)
817 mpath->sn = target_sn;
818 else
819 mpath->sn += 1;
820 spin_unlock_bh(&mpath->state_lock);
821 if (!ifmsh->mshcfg.dot11MeshForwarding)
822 goto endperr;
823 mesh_path_error_tx(sdata, ttl, target_addr,
824 target_sn, target_rcode,
825 broadcast_addr);
826 } else
827 spin_unlock_bh(&mpath->state_lock);
828 }
829endperr:
830 rcu_read_unlock();
831}
832
833static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
834 struct ieee80211_mgmt *mgmt,
835 const struct ieee80211_rann_ie *rann)
836{
837 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
838 struct ieee80211_local *local = sdata->local;
839 struct sta_info *sta;
840 struct mesh_path *mpath;
841 u8 ttl, flags, hopcount;
842 const u8 *orig_addr;
843 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
844 bool root_is_gate;
845
846 ttl = rann->rann_ttl;
847 flags = rann->rann_flags;
848 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
849 orig_addr = rann->rann_addr;
850 orig_sn = le32_to_cpu(rann->rann_seq);
851 interval = le32_to_cpu(rann->rann_interval);
852 hopcount = rann->rann_hopcount;
853 hopcount++;
854 orig_metric = le32_to_cpu(rann->rann_metric);
855
856 /* Ignore our own RANNs */
857 if (ether_addr_equal(orig_addr, sdata->vif.addr))
858 return;
859
860 mhwmp_dbg(sdata,
861 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
862 orig_addr, mgmt->sa, root_is_gate);
863
864 rcu_read_lock();
865 sta = sta_info_get(sdata, mgmt->sa);
866 if (!sta) {
867 rcu_read_unlock();
868 return;
869 }
870
871 last_hop_metric = airtime_link_metric_get(local, sta);
872 new_metric = orig_metric + last_hop_metric;
873 if (new_metric < orig_metric)
874 new_metric = MAX_METRIC;
875
876 mpath = mesh_path_lookup(sdata, orig_addr);
877 if (!mpath) {
878 mpath = mesh_path_add(sdata, orig_addr);
879 if (IS_ERR(mpath)) {
880 rcu_read_unlock();
881 sdata->u.mesh.mshstats.dropped_frames_no_route++;
882 return;
883 }
884 }
885
886 if (!(SN_LT(mpath->sn, orig_sn)) &&
887 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
888 rcu_read_unlock();
889 return;
890 }
891
892 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
893 (time_after(jiffies, mpath->last_preq_to_root +
894 root_path_confirmation_jiffies(sdata)) ||
895 time_before(jiffies, mpath->last_preq_to_root))) &&
896 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
897 mhwmp_dbg(sdata,
898 "time to refresh root mpath %pM\n",
899 orig_addr);
900 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
901 mpath->last_preq_to_root = jiffies;
902 }
903
904 mpath->sn = orig_sn;
905 mpath->rann_metric = new_metric;
906 mpath->is_root = true;
907 /* Recording RANNs sender address to send individually
908 * addressed PREQs destined for root mesh STA */
909 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
910
911 if (root_is_gate)
912 mesh_path_add_gate(mpath);
913
914 if (ttl <= 1) {
915 ifmsh->mshstats.dropped_frames_ttl++;
916 rcu_read_unlock();
917 return;
918 }
919 ttl--;
920
921 if (ifmsh->mshcfg.dot11MeshForwarding) {
922 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
923 orig_sn, 0, NULL, 0, broadcast_addr,
924 hopcount, ttl, interval,
925 new_metric, 0, sdata);
926 }
927
928 rcu_read_unlock();
929}
930
931
932void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
933 struct ieee80211_mgmt *mgmt, size_t len)
934{
935 struct ieee802_11_elems *elems;
936 size_t baselen;
937 u32 path_metric;
938 struct sta_info *sta;
939
940 /* need action_code */
941 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
942 return;
943
944 rcu_read_lock();
945 sta = sta_info_get(sdata, mgmt->sa);
946 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
947 rcu_read_unlock();
948 return;
949 }
950 rcu_read_unlock();
951
952 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
953 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
954 len - baselen, false, NULL);
955 if (!elems)
956 return;
957
958 if (elems->preq) {
959 if (elems->preq_len != 37)
960 /* Right now we support just 1 destination and no AE */
961 goto free;
962 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
963 MPATH_PREQ);
964 if (path_metric)
965 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
966 path_metric);
967 }
968 if (elems->prep) {
969 if (elems->prep_len != 31)
970 /* Right now we support no AE */
971 goto free;
972 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
973 MPATH_PREP);
974 if (path_metric)
975 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
976 path_metric);
977 }
978 if (elems->perr) {
979 if (elems->perr_len != 15)
980 /* Right now we support only one destination per PERR */
981 goto free;
982 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
983 }
984 if (elems->rann)
985 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
986free:
987 kfree(elems);
988}
989
990/**
991 * mesh_queue_preq - queue a PREQ to a given destination
992 *
993 * @mpath: mesh path to discover
994 * @flags: special attributes of the PREQ to be sent
995 *
996 * Locking: the function must be called from within a rcu read lock block.
997 *
998 */
999static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
1000{
1001 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1002 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1003 struct mesh_preq_queue *preq_node;
1004
1005 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
1006 if (!preq_node) {
1007 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
1008 return;
1009 }
1010
1011 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1012 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
1013 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1014 kfree(preq_node);
1015 if (printk_ratelimit())
1016 mhwmp_dbg(sdata, "PREQ node queue full\n");
1017 return;
1018 }
1019
1020 spin_lock(&mpath->state_lock);
1021 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1022 spin_unlock(&mpath->state_lock);
1023 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1024 kfree(preq_node);
1025 return;
1026 }
1027
1028 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1029 preq_node->flags = flags;
1030
1031 mpath->flags |= MESH_PATH_REQ_QUEUED;
1032 spin_unlock(&mpath->state_lock);
1033
1034 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1035 ++ifmsh->preq_queue_len;
1036 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1037
1038 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1039 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1040
1041 else if (time_before(jiffies, ifmsh->last_preq)) {
1042 /* avoid long wait if did not send preqs for a long time
1043 * and jiffies wrapped around
1044 */
1045 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1046 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1047 } else
1048 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1049 min_preq_int_jiff(sdata));
1050}
1051
1052/**
1053 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1054 *
1055 * @sdata: local mesh subif
1056 */
1057void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1058{
1059 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1060 struct mesh_preq_queue *preq_node;
1061 struct mesh_path *mpath;
1062 u8 ttl, target_flags = 0;
1063 const u8 *da;
1064 u32 lifetime;
1065
1066 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1067 if (!ifmsh->preq_queue_len ||
1068 time_before(jiffies, ifmsh->last_preq +
1069 min_preq_int_jiff(sdata))) {
1070 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1071 return;
1072 }
1073
1074 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1075 struct mesh_preq_queue, list);
1076 list_del(&preq_node->list);
1077 --ifmsh->preq_queue_len;
1078 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1079
1080 rcu_read_lock();
1081 mpath = mesh_path_lookup(sdata, preq_node->dst);
1082 if (!mpath)
1083 goto enddiscovery;
1084
1085 spin_lock_bh(&mpath->state_lock);
1086 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1087 spin_unlock_bh(&mpath->state_lock);
1088 goto enddiscovery;
1089 }
1090 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1091 if (preq_node->flags & PREQ_Q_F_START) {
1092 if (mpath->flags & MESH_PATH_RESOLVING) {
1093 spin_unlock_bh(&mpath->state_lock);
1094 goto enddiscovery;
1095 } else {
1096 mpath->flags &= ~MESH_PATH_RESOLVED;
1097 mpath->flags |= MESH_PATH_RESOLVING;
1098 mpath->discovery_retries = 0;
1099 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1100 }
1101 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1102 mpath->flags & MESH_PATH_RESOLVED) {
1103 mpath->flags &= ~MESH_PATH_RESOLVING;
1104 spin_unlock_bh(&mpath->state_lock);
1105 goto enddiscovery;
1106 }
1107
1108 ifmsh->last_preq = jiffies;
1109
1110 if (time_after(jiffies, ifmsh->last_sn_update +
1111 net_traversal_jiffies(sdata)) ||
1112 time_before(jiffies, ifmsh->last_sn_update)) {
1113 ++ifmsh->sn;
1114 sdata->u.mesh.last_sn_update = jiffies;
1115 }
1116 lifetime = default_lifetime(sdata);
1117 ttl = sdata->u.mesh.mshcfg.element_ttl;
1118 if (ttl == 0) {
1119 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1120 spin_unlock_bh(&mpath->state_lock);
1121 goto enddiscovery;
1122 }
1123
1124 if (preq_node->flags & PREQ_Q_F_REFRESH)
1125 target_flags |= IEEE80211_PREQ_TO_FLAG;
1126 else
1127 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1128
1129 spin_unlock_bh(&mpath->state_lock);
1130 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1131 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1132 target_flags, mpath->dst, mpath->sn, da, 0,
1133 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1134
1135 spin_lock_bh(&mpath->state_lock);
1136 if (!(mpath->flags & MESH_PATH_DELETED))
1137 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1138 spin_unlock_bh(&mpath->state_lock);
1139
1140enddiscovery:
1141 rcu_read_unlock();
1142 kfree(preq_node);
1143}
1144
1145/**
1146 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1147 *
1148 * @sdata: network subif the frame will be sent through
1149 * @skb: 802.11 frame to be sent
1150 *
1151 * Lookup next hop for given skb and start path discovery if no
1152 * forwarding information is found.
1153 *
1154 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1155 * skb is freed here if no mpath could be allocated.
1156 */
1157int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1158 struct sk_buff *skb)
1159{
1160 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1161 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1162 struct mesh_path *mpath;
1163 struct sk_buff *skb_to_free = NULL;
1164 u8 *target_addr = hdr->addr3;
1165
1166 /* Nulls are only sent to peers for PS and should be pre-addressed */
1167 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1168 return 0;
1169
1170 /* Allow injected packets to bypass mesh routing */
1171 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1172 return 0;
1173
1174 if (!mesh_nexthop_lookup(sdata, skb))
1175 return 0;
1176
1177 /* no nexthop found, start resolving */
1178 mpath = mesh_path_lookup(sdata, target_addr);
1179 if (!mpath) {
1180 mpath = mesh_path_add(sdata, target_addr);
1181 if (IS_ERR(mpath)) {
1182 mesh_path_discard_frame(sdata, skb);
1183 return PTR_ERR(mpath);
1184 }
1185 }
1186
1187 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1188 mesh_path_sel_is_hwmp(sdata))
1189 mesh_queue_preq(mpath, PREQ_Q_F_START);
1190
1191 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1192 skb_to_free = skb_dequeue(&mpath->frame_queue);
1193
1194 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1195 ieee80211_set_qos_hdr(sdata, skb);
1196 skb_queue_tail(&mpath->frame_queue, skb);
1197 if (skb_to_free)
1198 mesh_path_discard_frame(sdata, skb_to_free);
1199
1200 return -ENOENT;
1201}
1202
1203/**
1204 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1205 * @skb: 802.11 frame to be sent
1206 * @sdata: network subif the frame will be sent through
1207 *
1208 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1209 * And if so, set the RA (addr1) to it to transmit to this node directly,
1210 * avoiding PREQ/PREP path discovery.
1211 *
1212 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1213 */
1214static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1215 struct sk_buff *skb)
1216{
1217 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1218 struct sta_info *sta;
1219
1220 if (is_multicast_ether_addr(hdr->addr1))
1221 return -ENOENT;
1222
1223 rcu_read_lock();
1224 sta = sta_info_get(sdata, hdr->addr3);
1225
1226 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1227 rcu_read_unlock();
1228 return -ENOENT;
1229 }
1230 rcu_read_unlock();
1231
1232 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1233 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1234 return 0;
1235}
1236
1237void mesh_path_refresh(struct ieee80211_sub_if_data *sdata,
1238 struct mesh_path *mpath, const u8 *addr)
1239{
1240 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED |
1241 MESH_PATH_RESOLVING))
1242 return;
1243
1244 if (time_after(jiffies,
1245 mpath->exp_time -
1246 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1247 (!addr || ether_addr_equal(sdata->vif.addr, addr)))
1248 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1249}
1250
1251/**
1252 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1253 * this function is considered "using" the associated mpath, so preempt a path
1254 * refresh if this mpath expires soon.
1255 *
1256 * @sdata: network subif the frame will be sent through
1257 * @skb: 802.11 frame to be sent
1258 *
1259 * Returns: 0 if the next hop was found. Nonzero otherwise.
1260 */
1261int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1262 struct sk_buff *skb)
1263{
1264 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1265 struct mesh_path *mpath;
1266 struct sta_info *next_hop;
1267 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1268 u8 *target_addr = hdr->addr3;
1269
1270 if (ifmsh->mshcfg.dot11MeshNolearn &&
1271 !mesh_nexthop_lookup_nolearn(sdata, skb))
1272 return 0;
1273
1274 mpath = mesh_path_lookup(sdata, target_addr);
1275 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1276 return -ENOENT;
1277
1278 mesh_path_refresh(sdata, mpath, hdr->addr4);
1279
1280 next_hop = rcu_dereference(mpath->next_hop);
1281 if (next_hop) {
1282 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1283 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1284 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1285 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT))
1286 mesh_fast_tx_cache(sdata, skb, mpath);
1287 return 0;
1288 }
1289
1290 return -ENOENT;
1291}
1292
1293void mesh_path_timer(struct timer_list *t)
1294{
1295 struct mesh_path *mpath = timer_container_of(mpath, t, timer);
1296 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1297 int ret;
1298
1299 if (sdata->local->quiescing)
1300 return;
1301
1302 spin_lock_bh(&mpath->state_lock);
1303 if (mpath->flags & MESH_PATH_RESOLVED ||
1304 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1305 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1306 spin_unlock_bh(&mpath->state_lock);
1307 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1308 ++mpath->discovery_retries;
1309 mpath->discovery_timeout *= 2;
1310 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1311 spin_unlock_bh(&mpath->state_lock);
1312 mesh_queue_preq(mpath, 0);
1313 } else {
1314 mpath->flags &= ~(MESH_PATH_RESOLVING |
1315 MESH_PATH_RESOLVED |
1316 MESH_PATH_REQ_QUEUED);
1317 mpath->exp_time = jiffies;
1318 spin_unlock_bh(&mpath->state_lock);
1319 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1320 ret = mesh_path_send_to_gates(mpath);
1321 if (ret)
1322 mhwmp_dbg(sdata, "no gate was reachable\n");
1323 } else
1324 mesh_path_flush_pending(mpath);
1325 }
1326}
1327
1328void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1329{
1330 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1331 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1332 u8 flags, target_flags = 0;
1333
1334 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1335 ? RANN_FLAG_IS_GATE : 0;
1336
1337 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1338 case IEEE80211_PROACTIVE_RANN:
1339 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1340 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1341 0, ifmsh->mshcfg.element_ttl,
1342 interval, 0, 0, sdata);
1343 break;
1344 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1345 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1346 fallthrough;
1347 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1348 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1349 target_flags |= IEEE80211_PREQ_TO_FLAG |
1350 IEEE80211_PREQ_USN_FLAG;
1351 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1352 ++ifmsh->sn, target_flags,
1353 (u8 *) broadcast_addr, 0, broadcast_addr,
1354 0, ifmsh->mshcfg.element_ttl, interval,
1355 0, ifmsh->preq_id++, sdata);
1356 break;
1357 default:
1358 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1359 return;
1360 }
1361}
Linux 6.x block layer and io_uring tree(s)