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
21 static void mesh_queue_preq(struct mesh_path *, u8);
22
u32_field_get(const u8 * preq_elem,int offset,bool ae)23 static 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
u16_field_get(const u8 * preq_elem,int offset,bool ae)30 static 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
SN_DELTA(u32 x,u32 y)74 static 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
91 enum mpath_frame_type {
92 MPATH_PREQ = 0,
93 MPATH_PREP,
94 MPATH_PERR,
95 MPATH_RANN
96 };
97
98 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
99
mesh_path_sel_frame_tx(enum mpath_frame_type action,u8 flags,const u8 * orig_addr,u32 orig_sn,u8 target_flags,const u8 * target,u32 target_sn,const u8 * da,u8 hop_count,u8 ttl,u32 lifetime,u32 metric,u32 preq_id,struct ieee80211_sub_if_data * sdata)100 static 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. */
prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)200 static 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 * @ttl: allowed remaining hops
224 * @target: broken destination
225 * @target_sn: SN of the broken destination
226 * @target_rcode: reason code for this PERR
227 * @ra: node this frame is addressed to
228 * @sdata: local mesh subif
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 */
mesh_path_error_tx(struct ieee80211_sub_if_data * sdata,u8 ttl,const u8 * target,u32 target_sn,u16 target_rcode,const u8 * ra)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 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
ieee80211s_update_metric(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_tx_status * st)297 void 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
airtime_link_metric_get(struct ieee80211_local * local,struct sta_info * sta)325 u32 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 /**
371 * hwmp_route_info_get - Update routing info to originator and transmitter
372 *
373 * @sdata: local mesh subif
374 * @mgmt: mesh management frame
375 * @hwmp_ie: hwmp information element (PREP or PREQ)
376 * @action: type of hwmp ie
377 *
378 * This function updates the path routing information to the originator and the
379 * transmitter of a HWMP PREQ or PREP frame.
380 *
381 * Returns: metric to frame originator or 0 if the frame should not be further
382 * processed
383 *
384 * Notes: this function is the only place (besides user-provided info) where
385 * path routing information is updated.
386 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)387 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
388 struct ieee80211_mgmt *mgmt,
389 const u8 *hwmp_ie, enum mpath_frame_type action)
390 {
391 struct ieee80211_local *local = sdata->local;
392 struct mesh_path *mpath;
393 struct sta_info *sta;
394 bool fresh_info;
395 const u8 *orig_addr, *ta;
396 u32 orig_sn, orig_metric;
397 unsigned long orig_lifetime, exp_time;
398 u32 last_hop_metric, new_metric;
399 bool flush_mpath = false;
400 bool process = true;
401 u8 hopcount;
402
403 rcu_read_lock();
404 sta = sta_info_get(sdata, mgmt->sa);
405 if (!sta) {
406 rcu_read_unlock();
407 return 0;
408 }
409
410 last_hop_metric = airtime_link_metric_get(local, sta);
411 /* Update and check originator routing info */
412 fresh_info = true;
413
414 switch (action) {
415 case MPATH_PREQ:
416 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
417 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
418 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
419 orig_metric = PREQ_IE_METRIC(hwmp_ie);
420 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
421 break;
422 case MPATH_PREP:
423 /* Originator here refers to the MP that was the target in the
424 * Path Request. We divert from the nomenclature in the draft
425 * so that we can easily use a single function to gather path
426 * information from both PREQ and PREP frames.
427 */
428 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
429 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
430 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
431 orig_metric = PREP_IE_METRIC(hwmp_ie);
432 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
433 break;
434 default:
435 rcu_read_unlock();
436 return 0;
437 }
438 new_metric = orig_metric + last_hop_metric;
439 if (new_metric < orig_metric)
440 new_metric = MAX_METRIC;
441 exp_time = TU_TO_EXP_TIME(orig_lifetime);
442
443 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
444 /* This MP is the originator, we are not interested in this
445 * frame, except for updating transmitter's path info.
446 */
447 process = false;
448 fresh_info = false;
449 } else {
450 mpath = mesh_path_lookup(sdata, orig_addr);
451 if (mpath) {
452 spin_lock_bh(&mpath->state_lock);
453 if (mpath->flags & MESH_PATH_FIXED)
454 fresh_info = false;
455 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
456 (mpath->flags & MESH_PATH_SN_VALID)) {
457 if (SN_GT(mpath->sn, orig_sn) ||
458 (mpath->sn == orig_sn &&
459 (rcu_access_pointer(mpath->next_hop) !=
460 sta ?
461 mult_frac(new_metric, 10, 9) :
462 new_metric) >= mpath->metric)) {
463 process = false;
464 fresh_info = false;
465 }
466 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
467 bool have_sn, newer_sn, bounced;
468
469 have_sn = mpath->flags & MESH_PATH_SN_VALID;
470 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
471 bounced = have_sn &&
472 (SN_DELTA(orig_sn, mpath->sn) >
473 MAX_SANE_SN_DELTA);
474
475 if (!have_sn || newer_sn) {
476 /* if SN is newer than what we had
477 * then we can take it */;
478 } else if (bounced) {
479 /* if SN is way different than what
480 * we had then assume the other side
481 * rebooted or restarted */;
482 } else {
483 process = false;
484 fresh_info = false;
485 }
486 }
487 } else {
488 mpath = mesh_path_add(sdata, orig_addr);
489 if (IS_ERR(mpath)) {
490 rcu_read_unlock();
491 return 0;
492 }
493 spin_lock_bh(&mpath->state_lock);
494 }
495
496 if (fresh_info) {
497 if (rcu_access_pointer(mpath->next_hop) != sta) {
498 mpath->path_change_count++;
499 flush_mpath = true;
500 }
501 mesh_path_assign_nexthop(mpath, sta);
502 mpath->flags |= MESH_PATH_SN_VALID;
503 mpath->metric = new_metric;
504 mpath->sn = orig_sn;
505 mpath->exp_time = time_after(mpath->exp_time, exp_time)
506 ? mpath->exp_time : exp_time;
507 mpath->hop_count = hopcount;
508 mesh_path_activate(mpath);
509 spin_unlock_bh(&mpath->state_lock);
510 if (flush_mpath)
511 mesh_fast_tx_flush_mpath(mpath);
512 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
513 /* init it at a low value - 0 start is tricky */
514 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
515 mesh_path_tx_pending(mpath);
516 /* draft says preq_id should be saved to, but there does
517 * not seem to be any use for it, skipping by now
518 */
519 } else
520 spin_unlock_bh(&mpath->state_lock);
521 }
522
523 /* Update and check transmitter routing info */
524 ta = mgmt->sa;
525 if (ether_addr_equal(orig_addr, ta))
526 fresh_info = false;
527 else {
528 fresh_info = true;
529
530 mpath = mesh_path_lookup(sdata, ta);
531 if (mpath) {
532 spin_lock_bh(&mpath->state_lock);
533 if ((mpath->flags & MESH_PATH_FIXED) ||
534 ((mpath->flags & MESH_PATH_ACTIVE) &&
535 ((rcu_access_pointer(mpath->next_hop) != sta ?
536 mult_frac(last_hop_metric, 10, 9) :
537 last_hop_metric) > mpath->metric)))
538 fresh_info = false;
539 } else {
540 mpath = mesh_path_add(sdata, ta);
541 if (IS_ERR(mpath)) {
542 rcu_read_unlock();
543 return 0;
544 }
545 spin_lock_bh(&mpath->state_lock);
546 }
547
548 if (fresh_info) {
549 if (rcu_access_pointer(mpath->next_hop) != sta) {
550 mpath->path_change_count++;
551 flush_mpath = true;
552 }
553 mesh_path_assign_nexthop(mpath, sta);
554 mpath->metric = last_hop_metric;
555 mpath->exp_time = time_after(mpath->exp_time, exp_time)
556 ? mpath->exp_time : exp_time;
557 mpath->hop_count = 1;
558 mesh_path_activate(mpath);
559 spin_unlock_bh(&mpath->state_lock);
560 if (flush_mpath)
561 mesh_fast_tx_flush_mpath(mpath);
562 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
563 /* init it at a low value - 0 start is tricky */
564 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
565 mesh_path_tx_pending(mpath);
566 } else
567 spin_unlock_bh(&mpath->state_lock);
568 }
569
570 rcu_read_unlock();
571
572 return process ? new_metric : 0;
573 }
574
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)575 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
576 struct ieee80211_mgmt *mgmt,
577 const u8 *preq_elem, u32 orig_metric)
578 {
579 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
580 struct mesh_path *mpath = NULL;
581 const u8 *target_addr, *orig_addr;
582 const u8 *da;
583 u8 target_flags, ttl, flags;
584 u32 orig_sn, target_sn, lifetime, target_metric = 0;
585 bool reply = false;
586 bool forward = true;
587 bool root_is_gate;
588
589 /* Update target SN, if present */
590 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
591 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
592 target_sn = PREQ_IE_TARGET_SN(preq_elem);
593 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
594 target_flags = PREQ_IE_TARGET_F(preq_elem);
595 /* Proactive PREQ gate announcements */
596 flags = PREQ_IE_FLAGS(preq_elem);
597 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
598
599 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
600
601 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
602 mhwmp_dbg(sdata, "PREQ is for us\n");
603 forward = false;
604 reply = true;
605 target_metric = 0;
606
607 if (SN_GT(target_sn, ifmsh->sn))
608 ifmsh->sn = target_sn;
609
610 if (time_after(jiffies, ifmsh->last_sn_update +
611 net_traversal_jiffies(sdata)) ||
612 time_before(jiffies, ifmsh->last_sn_update)) {
613 ++ifmsh->sn;
614 ifmsh->last_sn_update = jiffies;
615 }
616 target_sn = ifmsh->sn;
617 } else if (is_broadcast_ether_addr(target_addr) &&
618 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
619 rcu_read_lock();
620 mpath = mesh_path_lookup(sdata, orig_addr);
621 if (mpath) {
622 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
623 reply = true;
624 target_addr = sdata->vif.addr;
625 target_sn = ++ifmsh->sn;
626 target_metric = 0;
627 ifmsh->last_sn_update = jiffies;
628 }
629 if (root_is_gate)
630 mesh_path_add_gate(mpath);
631 }
632 rcu_read_unlock();
633 } else {
634 rcu_read_lock();
635 mpath = mesh_path_lookup(sdata, target_addr);
636 if (mpath) {
637 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
638 SN_LT(mpath->sn, target_sn)) {
639 mpath->sn = target_sn;
640 mpath->flags |= MESH_PATH_SN_VALID;
641 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
642 (mpath->flags & MESH_PATH_ACTIVE)) {
643 reply = true;
644 target_metric = mpath->metric;
645 target_sn = mpath->sn;
646 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
647 target_flags |= IEEE80211_PREQ_TO_FLAG;
648 }
649 }
650 rcu_read_unlock();
651 }
652
653 if (reply) {
654 lifetime = PREQ_IE_LIFETIME(preq_elem);
655 ttl = ifmsh->mshcfg.element_ttl;
656 if (ttl != 0) {
657 mhwmp_dbg(sdata, "replying to the PREQ\n");
658 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
659 orig_sn, 0, target_addr,
660 target_sn, mgmt->sa, 0, ttl,
661 lifetime, target_metric, 0,
662 sdata);
663 } else {
664 ifmsh->mshstats.dropped_frames_ttl++;
665 }
666 }
667
668 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
669 u32 preq_id;
670 u8 hopcount;
671
672 ttl = PREQ_IE_TTL(preq_elem);
673 lifetime = PREQ_IE_LIFETIME(preq_elem);
674 if (ttl <= 1) {
675 ifmsh->mshstats.dropped_frames_ttl++;
676 return;
677 }
678 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
679 --ttl;
680 preq_id = PREQ_IE_PREQ_ID(preq_elem);
681 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
682 da = (mpath && mpath->is_root) ?
683 mpath->rann_snd_addr : broadcast_addr;
684
685 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
686 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
687 target_sn = PREQ_IE_TARGET_SN(preq_elem);
688 }
689
690 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
691 orig_sn, target_flags, target_addr,
692 target_sn, da, hopcount, ttl, lifetime,
693 orig_metric, preq_id, sdata);
694 if (!is_multicast_ether_addr(da))
695 ifmsh->mshstats.fwded_unicast++;
696 else
697 ifmsh->mshstats.fwded_mcast++;
698 ifmsh->mshstats.fwded_frames++;
699 }
700 }
701
702
703 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)704 next_hop_deref_protected(struct mesh_path *mpath)
705 {
706 return rcu_dereference_protected(mpath->next_hop,
707 lockdep_is_held(&mpath->state_lock));
708 }
709
710
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)711 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
712 struct ieee80211_mgmt *mgmt,
713 const u8 *prep_elem, u32 metric)
714 {
715 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
716 struct mesh_path *mpath;
717 const u8 *target_addr, *orig_addr;
718 u8 ttl, hopcount, flags;
719 u8 next_hop[ETH_ALEN];
720 u32 target_sn, orig_sn, lifetime;
721
722 mhwmp_dbg(sdata, "received PREP from %pM\n",
723 PREP_IE_TARGET_ADDR(prep_elem));
724
725 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
726 if (ether_addr_equal(orig_addr, sdata->vif.addr))
727 /* destination, no forwarding required */
728 return;
729
730 if (!ifmsh->mshcfg.dot11MeshForwarding)
731 return;
732
733 ttl = PREP_IE_TTL(prep_elem);
734 if (ttl <= 1) {
735 sdata->u.mesh.mshstats.dropped_frames_ttl++;
736 return;
737 }
738
739 rcu_read_lock();
740 mpath = mesh_path_lookup(sdata, orig_addr);
741 if (mpath)
742 spin_lock_bh(&mpath->state_lock);
743 else
744 goto fail;
745 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
746 spin_unlock_bh(&mpath->state_lock);
747 goto fail;
748 }
749 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
750 spin_unlock_bh(&mpath->state_lock);
751 --ttl;
752 flags = PREP_IE_FLAGS(prep_elem);
753 lifetime = PREP_IE_LIFETIME(prep_elem);
754 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
755 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
756 target_sn = PREP_IE_TARGET_SN(prep_elem);
757 orig_sn = PREP_IE_ORIG_SN(prep_elem);
758
759 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
760 target_addr, target_sn, next_hop, hopcount,
761 ttl, lifetime, metric, 0, sdata);
762 rcu_read_unlock();
763
764 sdata->u.mesh.mshstats.fwded_unicast++;
765 sdata->u.mesh.mshstats.fwded_frames++;
766 return;
767
768 fail:
769 rcu_read_unlock();
770 sdata->u.mesh.mshstats.dropped_frames_no_route++;
771 }
772
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)773 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
774 struct ieee80211_mgmt *mgmt,
775 const u8 *perr_elem)
776 {
777 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
778 struct mesh_path *mpath;
779 u8 ttl;
780 const u8 *ta, *target_addr;
781 u32 target_sn;
782 u16 target_rcode;
783
784 ta = mgmt->sa;
785 ttl = PERR_IE_TTL(perr_elem);
786 if (ttl <= 1) {
787 ifmsh->mshstats.dropped_frames_ttl++;
788 return;
789 }
790 ttl--;
791 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
792 target_sn = PERR_IE_TARGET_SN(perr_elem);
793 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
794
795 rcu_read_lock();
796 mpath = mesh_path_lookup(sdata, target_addr);
797 if (mpath) {
798 struct sta_info *sta;
799
800 spin_lock_bh(&mpath->state_lock);
801 sta = next_hop_deref_protected(mpath);
802 if (mpath->flags & MESH_PATH_ACTIVE &&
803 ether_addr_equal(ta, sta->sta.addr) &&
804 !(mpath->flags & MESH_PATH_FIXED) &&
805 (!(mpath->flags & MESH_PATH_SN_VALID) ||
806 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
807 mpath->flags &= ~MESH_PATH_ACTIVE;
808 if (target_sn != 0)
809 mpath->sn = target_sn;
810 else
811 mpath->sn += 1;
812 spin_unlock_bh(&mpath->state_lock);
813 if (!ifmsh->mshcfg.dot11MeshForwarding)
814 goto endperr;
815 mesh_path_error_tx(sdata, ttl, target_addr,
816 target_sn, target_rcode,
817 broadcast_addr);
818 } else
819 spin_unlock_bh(&mpath->state_lock);
820 }
821 endperr:
822 rcu_read_unlock();
823 }
824
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)825 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
826 struct ieee80211_mgmt *mgmt,
827 const struct ieee80211_rann_ie *rann)
828 {
829 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
830 struct ieee80211_local *local = sdata->local;
831 struct sta_info *sta;
832 struct mesh_path *mpath;
833 u8 ttl, flags, hopcount;
834 const u8 *orig_addr;
835 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
836 bool root_is_gate;
837
838 ttl = rann->rann_ttl;
839 flags = rann->rann_flags;
840 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
841 orig_addr = rann->rann_addr;
842 orig_sn = le32_to_cpu(rann->rann_seq);
843 interval = le32_to_cpu(rann->rann_interval);
844 hopcount = rann->rann_hopcount;
845 hopcount++;
846 orig_metric = le32_to_cpu(rann->rann_metric);
847
848 /* Ignore our own RANNs */
849 if (ether_addr_equal(orig_addr, sdata->vif.addr))
850 return;
851
852 mhwmp_dbg(sdata,
853 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
854 orig_addr, mgmt->sa, root_is_gate);
855
856 rcu_read_lock();
857 sta = sta_info_get(sdata, mgmt->sa);
858 if (!sta) {
859 rcu_read_unlock();
860 return;
861 }
862
863 last_hop_metric = airtime_link_metric_get(local, sta);
864 new_metric = orig_metric + last_hop_metric;
865 if (new_metric < orig_metric)
866 new_metric = MAX_METRIC;
867
868 mpath = mesh_path_lookup(sdata, orig_addr);
869 if (!mpath) {
870 mpath = mesh_path_add(sdata, orig_addr);
871 if (IS_ERR(mpath)) {
872 rcu_read_unlock();
873 sdata->u.mesh.mshstats.dropped_frames_no_route++;
874 return;
875 }
876 }
877
878 if (!(SN_LT(mpath->sn, orig_sn)) &&
879 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
880 rcu_read_unlock();
881 return;
882 }
883
884 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
885 (time_after(jiffies, mpath->last_preq_to_root +
886 root_path_confirmation_jiffies(sdata)) ||
887 time_before(jiffies, mpath->last_preq_to_root))) &&
888 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
889 mhwmp_dbg(sdata,
890 "time to refresh root mpath %pM\n",
891 orig_addr);
892 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
893 mpath->last_preq_to_root = jiffies;
894 }
895
896 mpath->sn = orig_sn;
897 mpath->rann_metric = new_metric;
898 mpath->is_root = true;
899 /* Recording RANNs sender address to send individually
900 * addressed PREQs destined for root mesh STA */
901 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
902
903 if (root_is_gate)
904 mesh_path_add_gate(mpath);
905
906 if (ttl <= 1) {
907 ifmsh->mshstats.dropped_frames_ttl++;
908 rcu_read_unlock();
909 return;
910 }
911 ttl--;
912
913 if (ifmsh->mshcfg.dot11MeshForwarding) {
914 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
915 orig_sn, 0, NULL, 0, broadcast_addr,
916 hopcount, ttl, interval,
917 new_metric, 0, sdata);
918 }
919
920 rcu_read_unlock();
921 }
922
923
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)924 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
925 struct ieee80211_mgmt *mgmt, size_t len)
926 {
927 struct ieee802_11_elems *elems;
928 size_t baselen;
929 u32 path_metric;
930 struct sta_info *sta;
931
932 /* need action_code */
933 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
934 return;
935
936 rcu_read_lock();
937 sta = sta_info_get(sdata, mgmt->sa);
938 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
939 rcu_read_unlock();
940 return;
941 }
942 rcu_read_unlock();
943
944 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
945 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
946 len - baselen, false, NULL);
947 if (!elems)
948 return;
949
950 if (elems->preq) {
951 if (elems->preq_len != 37)
952 /* Right now we support just 1 destination and no AE */
953 goto free;
954 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
955 MPATH_PREQ);
956 if (path_metric)
957 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
958 path_metric);
959 }
960 if (elems->prep) {
961 if (elems->prep_len != 31)
962 /* Right now we support no AE */
963 goto free;
964 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
965 MPATH_PREP);
966 if (path_metric)
967 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
968 path_metric);
969 }
970 if (elems->perr) {
971 if (elems->perr_len != 15)
972 /* Right now we support only one destination per PERR */
973 goto free;
974 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
975 }
976 if (elems->rann)
977 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
978 free:
979 kfree(elems);
980 }
981
982 /**
983 * mesh_queue_preq - queue a PREQ to a given destination
984 *
985 * @mpath: mesh path to discover
986 * @flags: special attributes of the PREQ to be sent
987 *
988 * Locking: the function must be called from within a rcu read lock block.
989 *
990 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)991 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
992 {
993 struct ieee80211_sub_if_data *sdata = mpath->sdata;
994 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
995 struct mesh_preq_queue *preq_node;
996
997 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
998 if (!preq_node) {
999 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
1000 return;
1001 }
1002
1003 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1004 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
1005 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1006 kfree(preq_node);
1007 if (printk_ratelimit())
1008 mhwmp_dbg(sdata, "PREQ node queue full\n");
1009 return;
1010 }
1011
1012 spin_lock(&mpath->state_lock);
1013 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1014 spin_unlock(&mpath->state_lock);
1015 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1016 kfree(preq_node);
1017 return;
1018 }
1019
1020 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1021 preq_node->flags = flags;
1022
1023 mpath->flags |= MESH_PATH_REQ_QUEUED;
1024 spin_unlock(&mpath->state_lock);
1025
1026 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1027 ++ifmsh->preq_queue_len;
1028 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1029
1030 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1031 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1032
1033 else if (time_before(jiffies, ifmsh->last_preq)) {
1034 /* avoid long wait if did not send preqs for a long time
1035 * and jiffies wrapped around
1036 */
1037 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1038 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1039 } else
1040 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1041 min_preq_int_jiff(sdata));
1042 }
1043
1044 /**
1045 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1046 *
1047 * @sdata: local mesh subif
1048 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1049 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1050 {
1051 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1052 struct mesh_preq_queue *preq_node;
1053 struct mesh_path *mpath;
1054 u8 ttl, target_flags = 0;
1055 const u8 *da;
1056 u32 lifetime;
1057
1058 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1059 if (!ifmsh->preq_queue_len ||
1060 time_before(jiffies, ifmsh->last_preq +
1061 min_preq_int_jiff(sdata))) {
1062 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1063 return;
1064 }
1065
1066 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1067 struct mesh_preq_queue, list);
1068 list_del(&preq_node->list);
1069 --ifmsh->preq_queue_len;
1070 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1071
1072 rcu_read_lock();
1073 mpath = mesh_path_lookup(sdata, preq_node->dst);
1074 if (!mpath)
1075 goto enddiscovery;
1076
1077 spin_lock_bh(&mpath->state_lock);
1078 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1079 spin_unlock_bh(&mpath->state_lock);
1080 goto enddiscovery;
1081 }
1082 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1083 if (preq_node->flags & PREQ_Q_F_START) {
1084 if (mpath->flags & MESH_PATH_RESOLVING) {
1085 spin_unlock_bh(&mpath->state_lock);
1086 goto enddiscovery;
1087 } else {
1088 mpath->flags &= ~MESH_PATH_RESOLVED;
1089 mpath->flags |= MESH_PATH_RESOLVING;
1090 mpath->discovery_retries = 0;
1091 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1092 }
1093 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1094 mpath->flags & MESH_PATH_RESOLVED) {
1095 mpath->flags &= ~MESH_PATH_RESOLVING;
1096 spin_unlock_bh(&mpath->state_lock);
1097 goto enddiscovery;
1098 }
1099
1100 ifmsh->last_preq = jiffies;
1101
1102 if (time_after(jiffies, ifmsh->last_sn_update +
1103 net_traversal_jiffies(sdata)) ||
1104 time_before(jiffies, ifmsh->last_sn_update)) {
1105 ++ifmsh->sn;
1106 sdata->u.mesh.last_sn_update = jiffies;
1107 }
1108 lifetime = default_lifetime(sdata);
1109 ttl = sdata->u.mesh.mshcfg.element_ttl;
1110 if (ttl == 0) {
1111 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1112 spin_unlock_bh(&mpath->state_lock);
1113 goto enddiscovery;
1114 }
1115
1116 if (preq_node->flags & PREQ_Q_F_REFRESH)
1117 target_flags |= IEEE80211_PREQ_TO_FLAG;
1118 else
1119 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1120
1121 spin_unlock_bh(&mpath->state_lock);
1122 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1123 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1124 target_flags, mpath->dst, mpath->sn, da, 0,
1125 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1126
1127 spin_lock_bh(&mpath->state_lock);
1128 if (!(mpath->flags & MESH_PATH_DELETED))
1129 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1130 spin_unlock_bh(&mpath->state_lock);
1131
1132 enddiscovery:
1133 rcu_read_unlock();
1134 kfree(preq_node);
1135 }
1136
1137 /**
1138 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1139 *
1140 * @skb: 802.11 frame to be sent
1141 * @sdata: network subif the frame will be sent through
1142 *
1143 * Lookup next hop for given skb and start path discovery if no
1144 * forwarding information is found.
1145 *
1146 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1147 * skb is freed here if no mpath could be allocated.
1148 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1149 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1150 struct sk_buff *skb)
1151 {
1152 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1153 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1154 struct mesh_path *mpath;
1155 struct sk_buff *skb_to_free = NULL;
1156 u8 *target_addr = hdr->addr3;
1157
1158 /* Nulls are only sent to peers for PS and should be pre-addressed */
1159 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1160 return 0;
1161
1162 /* Allow injected packets to bypass mesh routing */
1163 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1164 return 0;
1165
1166 if (!mesh_nexthop_lookup(sdata, skb))
1167 return 0;
1168
1169 /* no nexthop found, start resolving */
1170 mpath = mesh_path_lookup(sdata, target_addr);
1171 if (!mpath) {
1172 mpath = mesh_path_add(sdata, target_addr);
1173 if (IS_ERR(mpath)) {
1174 mesh_path_discard_frame(sdata, skb);
1175 return PTR_ERR(mpath);
1176 }
1177 }
1178
1179 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1180 mesh_path_sel_is_hwmp(sdata))
1181 mesh_queue_preq(mpath, PREQ_Q_F_START);
1182
1183 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1184 skb_to_free = skb_dequeue(&mpath->frame_queue);
1185
1186 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1187 ieee80211_set_qos_hdr(sdata, skb);
1188 skb_queue_tail(&mpath->frame_queue, skb);
1189 if (skb_to_free)
1190 mesh_path_discard_frame(sdata, skb_to_free);
1191
1192 return -ENOENT;
1193 }
1194
1195 /**
1196 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1197 * @skb: 802.11 frame to be sent
1198 * @sdata: network subif the frame will be sent through
1199 *
1200 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1201 * And if so, set the RA (addr1) to it to transmit to this node directly,
1202 * avoiding PREQ/PREP path discovery.
1203 *
1204 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1205 */
mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1206 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1207 struct sk_buff *skb)
1208 {
1209 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1210 struct sta_info *sta;
1211
1212 if (is_multicast_ether_addr(hdr->addr1))
1213 return -ENOENT;
1214
1215 rcu_read_lock();
1216 sta = sta_info_get(sdata, hdr->addr3);
1217
1218 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1219 rcu_read_unlock();
1220 return -ENOENT;
1221 }
1222 rcu_read_unlock();
1223
1224 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1225 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1226 return 0;
1227 }
1228
mesh_path_refresh(struct ieee80211_sub_if_data * sdata,struct mesh_path * mpath,const u8 * addr)1229 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata,
1230 struct mesh_path *mpath, const u8 *addr)
1231 {
1232 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED |
1233 MESH_PATH_RESOLVING))
1234 return;
1235
1236 if (time_after(jiffies,
1237 mpath->exp_time -
1238 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1239 (!addr || ether_addr_equal(sdata->vif.addr, addr)))
1240 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1241 }
1242
1243 /**
1244 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1245 * this function is considered "using" the associated mpath, so preempt a path
1246 * refresh if this mpath expires soon.
1247 *
1248 * @skb: 802.11 frame to be sent
1249 * @sdata: network subif the frame will be sent through
1250 *
1251 * Returns: 0 if the next hop was found. Nonzero otherwise.
1252 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1253 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1254 struct sk_buff *skb)
1255 {
1256 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1257 struct mesh_path *mpath;
1258 struct sta_info *next_hop;
1259 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1260 u8 *target_addr = hdr->addr3;
1261
1262 if (ifmsh->mshcfg.dot11MeshNolearn &&
1263 !mesh_nexthop_lookup_nolearn(sdata, skb))
1264 return 0;
1265
1266 mpath = mesh_path_lookup(sdata, target_addr);
1267 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1268 return -ENOENT;
1269
1270 mesh_path_refresh(sdata, mpath, hdr->addr4);
1271
1272 next_hop = rcu_dereference(mpath->next_hop);
1273 if (next_hop) {
1274 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1275 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1276 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1277 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT))
1278 mesh_fast_tx_cache(sdata, skb, mpath);
1279 return 0;
1280 }
1281
1282 return -ENOENT;
1283 }
1284
mesh_path_timer(struct timer_list * t)1285 void mesh_path_timer(struct timer_list *t)
1286 {
1287 struct mesh_path *mpath = from_timer(mpath, t, timer);
1288 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1289 int ret;
1290
1291 if (sdata->local->quiescing)
1292 return;
1293
1294 spin_lock_bh(&mpath->state_lock);
1295 if (mpath->flags & MESH_PATH_RESOLVED ||
1296 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1297 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1298 spin_unlock_bh(&mpath->state_lock);
1299 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1300 ++mpath->discovery_retries;
1301 mpath->discovery_timeout *= 2;
1302 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1303 spin_unlock_bh(&mpath->state_lock);
1304 mesh_queue_preq(mpath, 0);
1305 } else {
1306 mpath->flags &= ~(MESH_PATH_RESOLVING |
1307 MESH_PATH_RESOLVED |
1308 MESH_PATH_REQ_QUEUED);
1309 mpath->exp_time = jiffies;
1310 spin_unlock_bh(&mpath->state_lock);
1311 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1312 ret = mesh_path_send_to_gates(mpath);
1313 if (ret)
1314 mhwmp_dbg(sdata, "no gate was reachable\n");
1315 } else
1316 mesh_path_flush_pending(mpath);
1317 }
1318 }
1319
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1320 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1321 {
1322 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1323 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1324 u8 flags, target_flags = 0;
1325
1326 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1327 ? RANN_FLAG_IS_GATE : 0;
1328
1329 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1330 case IEEE80211_PROACTIVE_RANN:
1331 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1332 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1333 0, ifmsh->mshcfg.element_ttl,
1334 interval, 0, 0, sdata);
1335 break;
1336 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1337 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1338 fallthrough;
1339 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1340 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1341 target_flags |= IEEE80211_PREQ_TO_FLAG |
1342 IEEE80211_PREQ_USN_FLAG;
1343 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1344 ++ifmsh->sn, target_flags,
1345 (u8 *) broadcast_addr, 0, broadcast_addr,
1346 0, ifmsh->mshcfg.element_ttl, interval,
1347 0, ifmsh->preq_id++, sdata);
1348 break;
1349 default:
1350 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1351 return;
1352 }
1353 }
1354