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 <asm/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 -ENOTSUPP;
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 */
mesh_path_error_tx(struct ieee80211_sub_if_data * sdata,u8 ttl,const u8 * target,u32 target_sn,u16 target_rcode,const u8 * ra)234 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
235 u8 ttl, const u8 *target, u32 target_sn,
236 u16 target_rcode, const u8 *ra)
237 {
238 struct ieee80211_local *local = sdata->local;
239 struct sk_buff *skb;
240 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
241 struct ieee80211_mgmt *mgmt;
242 u8 *pos, ie_len;
243 int hdr_len = offsetofend(struct ieee80211_mgmt,
244 u.action.u.mesh_action);
245
246 if (time_before(jiffies, ifmsh->next_perr))
247 return -EAGAIN;
248
249 skb = dev_alloc_skb(local->tx_headroom +
250 IEEE80211_ENCRYPT_HEADROOM +
251 IEEE80211_ENCRYPT_TAILROOM +
252 hdr_len +
253 2 + 15 /* PERR IE */);
254 if (!skb)
255 return -1;
256 skb_reserve(skb, local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM);
257 mgmt = skb_put_zero(skb, hdr_len);
258 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
259 IEEE80211_STYPE_ACTION);
260
261 memcpy(mgmt->da, ra, ETH_ALEN);
262 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
263 /* BSSID == SA */
264 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
265 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
266 mgmt->u.action.u.mesh_action.action_code =
267 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
268 ie_len = 15;
269 pos = skb_put(skb, 2 + ie_len);
270 *pos++ = WLAN_EID_PERR;
271 *pos++ = ie_len;
272 /* ttl */
273 *pos++ = ttl;
274 /* number of destinations */
275 *pos++ = 1;
276 /* Flags field has AE bit only as defined in
277 * sec 8.4.2.117 IEEE802.11-2012
278 */
279 *pos = 0;
280 pos++;
281 memcpy(pos, target, ETH_ALEN);
282 pos += ETH_ALEN;
283 put_unaligned_le32(target_sn, pos);
284 pos += 4;
285 put_unaligned_le16(target_rcode, pos);
286
287 /* see note in function header */
288 prepare_frame_for_deferred_tx(sdata, skb);
289 ifmsh->next_perr = TU_TO_EXP_TIME(
290 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
291 ieee80211_add_pending_skb(local, skb);
292 return 0;
293 }
294
ieee80211s_update_metric(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_tx_status * st)295 void ieee80211s_update_metric(struct ieee80211_local *local,
296 struct sta_info *sta,
297 struct ieee80211_tx_status *st)
298 {
299 struct ieee80211_tx_info *txinfo = st->info;
300 int failed;
301 struct rate_info rinfo;
302
303 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
304
305 /* moving average, scaled to 100.
306 * feed failure as 100 and success as 0
307 */
308 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
309 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
310 LINK_FAIL_THRESH)
311 mesh_plink_broken(sta);
312
313 /* use rate info set by the driver directly if present */
314 if (st->n_rates)
315 rinfo = sta->deflink.tx_stats.last_rate_info;
316 else
317 sta_set_rate_info_tx(sta, &sta->deflink.tx_stats.last_rate, &rinfo);
318
319 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg,
320 cfg80211_calculate_bitrate(&rinfo));
321 }
322
airtime_link_metric_get(struct ieee80211_local * local,struct sta_info * sta)323 u32 airtime_link_metric_get(struct ieee80211_local *local,
324 struct sta_info *sta)
325 {
326 /* This should be adjusted for each device */
327 int device_constant = 1 << ARITH_SHIFT;
328 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
329 int s_unit = 1 << ARITH_SHIFT;
330 int rate, err;
331 u32 tx_time, estimated_retx;
332 u64 result;
333 unsigned long fail_avg =
334 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
335
336 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB)
337 return MAX_METRIC;
338
339 /* Try to get rate based on HW/SW RC algorithm.
340 * Rate is returned in units of Kbps, correct this
341 * to comply with airtime calculation units
342 * Round up in case we get rate < 100Kbps
343 */
344 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
345
346 if (rate) {
347 err = 0;
348 } else {
349 if (fail_avg > LINK_FAIL_THRESH)
350 return MAX_METRIC;
351
352 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg);
353 if (WARN_ON(!rate))
354 return MAX_METRIC;
355
356 err = (fail_avg << ARITH_SHIFT) / 100;
357 }
358
359 /* bitrate is in units of 100 Kbps, while we need rate in units of
360 * 1Mbps. This will be corrected on tx_time computation.
361 */
362 tx_time = (device_constant + 10 * test_frame_len / rate);
363 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
364 result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
365 return (u32)result;
366 }
367
368 /**
369 * hwmp_route_info_get - Update routing info to originator and transmitter
370 *
371 * @sdata: local mesh subif
372 * @mgmt: mesh management frame
373 * @hwmp_ie: hwmp information element (PREP or PREQ)
374 * @action: type of hwmp ie
375 *
376 * This function updates the path routing information to the originator and the
377 * transmitter of a HWMP PREQ or PREP frame.
378 *
379 * Returns: metric to frame originator or 0 if the frame should not be further
380 * processed
381 *
382 * Notes: this function is the only place (besides user-provided info) where
383 * path routing information is updated.
384 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)385 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
386 struct ieee80211_mgmt *mgmt,
387 const u8 *hwmp_ie, enum mpath_frame_type action)
388 {
389 struct ieee80211_local *local = sdata->local;
390 struct mesh_path *mpath;
391 struct sta_info *sta;
392 bool fresh_info;
393 const u8 *orig_addr, *ta;
394 u32 orig_sn, orig_metric;
395 unsigned long orig_lifetime, exp_time;
396 u32 last_hop_metric, new_metric;
397 bool flush_mpath = false;
398 bool process = true;
399 u8 hopcount;
400
401 rcu_read_lock();
402 sta = sta_info_get(sdata, mgmt->sa);
403 if (!sta) {
404 rcu_read_unlock();
405 return 0;
406 }
407
408 last_hop_metric = airtime_link_metric_get(local, sta);
409 /* Update and check originator routing info */
410 fresh_info = true;
411
412 switch (action) {
413 case MPATH_PREQ:
414 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
415 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
416 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
417 orig_metric = PREQ_IE_METRIC(hwmp_ie);
418 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
419 break;
420 case MPATH_PREP:
421 /* Originator here refers to the MP that was the target in the
422 * Path Request. We divert from the nomenclature in the draft
423 * so that we can easily use a single function to gather path
424 * information from both PREQ and PREP frames.
425 */
426 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
427 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
428 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
429 orig_metric = PREP_IE_METRIC(hwmp_ie);
430 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
431 break;
432 default:
433 rcu_read_unlock();
434 return 0;
435 }
436 new_metric = orig_metric + last_hop_metric;
437 if (new_metric < orig_metric)
438 new_metric = MAX_METRIC;
439 exp_time = TU_TO_EXP_TIME(orig_lifetime);
440
441 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
442 /* This MP is the originator, we are not interested in this
443 * frame, except for updating transmitter's path info.
444 */
445 process = false;
446 fresh_info = false;
447 } else {
448 mpath = mesh_path_lookup(sdata, orig_addr);
449 if (mpath) {
450 spin_lock_bh(&mpath->state_lock);
451 if (mpath->flags & MESH_PATH_FIXED)
452 fresh_info = false;
453 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
454 (mpath->flags & MESH_PATH_SN_VALID)) {
455 if (SN_GT(mpath->sn, orig_sn) ||
456 (mpath->sn == orig_sn &&
457 (rcu_access_pointer(mpath->next_hop) !=
458 sta ?
459 mult_frac(new_metric, 10, 9) :
460 new_metric) >= mpath->metric)) {
461 process = false;
462 fresh_info = false;
463 }
464 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
465 bool have_sn, newer_sn, bounced;
466
467 have_sn = mpath->flags & MESH_PATH_SN_VALID;
468 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
469 bounced = have_sn &&
470 (SN_DELTA(orig_sn, mpath->sn) >
471 MAX_SANE_SN_DELTA);
472
473 if (!have_sn || newer_sn) {
474 /* if SN is newer than what we had
475 * then we can take it */;
476 } else if (bounced) {
477 /* if SN is way different than what
478 * we had then assume the other side
479 * rebooted or restarted */;
480 } else {
481 process = false;
482 fresh_info = false;
483 }
484 }
485 } else {
486 mpath = mesh_path_add(sdata, orig_addr);
487 if (IS_ERR(mpath)) {
488 rcu_read_unlock();
489 return 0;
490 }
491 spin_lock_bh(&mpath->state_lock);
492 }
493
494 if (fresh_info) {
495 if (rcu_access_pointer(mpath->next_hop) != sta) {
496 mpath->path_change_count++;
497 flush_mpath = true;
498 }
499 mesh_path_assign_nexthop(mpath, sta);
500 mpath->flags |= MESH_PATH_SN_VALID;
501 mpath->metric = new_metric;
502 mpath->sn = orig_sn;
503 mpath->exp_time = time_after(mpath->exp_time, exp_time)
504 ? mpath->exp_time : exp_time;
505 mpath->hop_count = hopcount;
506 mesh_path_activate(mpath);
507 spin_unlock_bh(&mpath->state_lock);
508 if (flush_mpath)
509 mesh_fast_tx_flush_mpath(mpath);
510 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
511 /* init it at a low value - 0 start is tricky */
512 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
513 mesh_path_tx_pending(mpath);
514 /* draft says preq_id should be saved to, but there does
515 * not seem to be any use for it, skipping by now
516 */
517 } else
518 spin_unlock_bh(&mpath->state_lock);
519 }
520
521 /* Update and check transmitter routing info */
522 ta = mgmt->sa;
523 if (ether_addr_equal(orig_addr, ta))
524 fresh_info = false;
525 else {
526 fresh_info = true;
527
528 mpath = mesh_path_lookup(sdata, ta);
529 if (mpath) {
530 spin_lock_bh(&mpath->state_lock);
531 if ((mpath->flags & MESH_PATH_FIXED) ||
532 ((mpath->flags & MESH_PATH_ACTIVE) &&
533 ((rcu_access_pointer(mpath->next_hop) != sta ?
534 mult_frac(last_hop_metric, 10, 9) :
535 last_hop_metric) > mpath->metric)))
536 fresh_info = false;
537 } else {
538 mpath = mesh_path_add(sdata, ta);
539 if (IS_ERR(mpath)) {
540 rcu_read_unlock();
541 return 0;
542 }
543 spin_lock_bh(&mpath->state_lock);
544 }
545
546 if (fresh_info) {
547 if (rcu_access_pointer(mpath->next_hop) != sta) {
548 mpath->path_change_count++;
549 flush_mpath = true;
550 }
551 mesh_path_assign_nexthop(mpath, sta);
552 mpath->metric = last_hop_metric;
553 mpath->exp_time = time_after(mpath->exp_time, exp_time)
554 ? mpath->exp_time : exp_time;
555 mpath->hop_count = 1;
556 mesh_path_activate(mpath);
557 spin_unlock_bh(&mpath->state_lock);
558 if (flush_mpath)
559 mesh_fast_tx_flush_mpath(mpath);
560 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
561 /* init it at a low value - 0 start is tricky */
562 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
563 mesh_path_tx_pending(mpath);
564 } else
565 spin_unlock_bh(&mpath->state_lock);
566 }
567
568 rcu_read_unlock();
569
570 return process ? new_metric : 0;
571 }
572
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)573 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
574 struct ieee80211_mgmt *mgmt,
575 const u8 *preq_elem, u32 orig_metric)
576 {
577 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
578 struct mesh_path *mpath = NULL;
579 const u8 *target_addr, *orig_addr;
580 const u8 *da;
581 u8 target_flags, ttl, flags;
582 u32 orig_sn, target_sn, lifetime, target_metric = 0;
583 bool reply = false;
584 bool forward = true;
585 bool root_is_gate;
586
587 /* Update target SN, if present */
588 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
589 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
590 target_sn = PREQ_IE_TARGET_SN(preq_elem);
591 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
592 target_flags = PREQ_IE_TARGET_F(preq_elem);
593 /* Proactive PREQ gate announcements */
594 flags = PREQ_IE_FLAGS(preq_elem);
595 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
596
597 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
598
599 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
600 mhwmp_dbg(sdata, "PREQ is for us\n");
601 forward = false;
602 reply = true;
603 target_metric = 0;
604
605 if (SN_GT(target_sn, ifmsh->sn))
606 ifmsh->sn = target_sn;
607
608 if (time_after(jiffies, ifmsh->last_sn_update +
609 net_traversal_jiffies(sdata)) ||
610 time_before(jiffies, ifmsh->last_sn_update)) {
611 ++ifmsh->sn;
612 ifmsh->last_sn_update = jiffies;
613 }
614 target_sn = ifmsh->sn;
615 } else if (is_broadcast_ether_addr(target_addr) &&
616 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
617 rcu_read_lock();
618 mpath = mesh_path_lookup(sdata, orig_addr);
619 if (mpath) {
620 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
621 reply = true;
622 target_addr = sdata->vif.addr;
623 target_sn = ++ifmsh->sn;
624 target_metric = 0;
625 ifmsh->last_sn_update = jiffies;
626 }
627 if (root_is_gate)
628 mesh_path_add_gate(mpath);
629 }
630 rcu_read_unlock();
631 } else {
632 rcu_read_lock();
633 mpath = mesh_path_lookup(sdata, target_addr);
634 if (mpath) {
635 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
636 SN_LT(mpath->sn, target_sn)) {
637 mpath->sn = target_sn;
638 mpath->flags |= MESH_PATH_SN_VALID;
639 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
640 (mpath->flags & MESH_PATH_ACTIVE)) {
641 reply = true;
642 target_metric = mpath->metric;
643 target_sn = mpath->sn;
644 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
645 target_flags |= IEEE80211_PREQ_TO_FLAG;
646 }
647 }
648 rcu_read_unlock();
649 }
650
651 if (reply) {
652 lifetime = PREQ_IE_LIFETIME(preq_elem);
653 ttl = ifmsh->mshcfg.element_ttl;
654 if (ttl != 0) {
655 mhwmp_dbg(sdata, "replying to the PREQ\n");
656 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
657 orig_sn, 0, target_addr,
658 target_sn, mgmt->sa, 0, ttl,
659 lifetime, target_metric, 0,
660 sdata);
661 } else {
662 ifmsh->mshstats.dropped_frames_ttl++;
663 }
664 }
665
666 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
667 u32 preq_id;
668 u8 hopcount;
669
670 ttl = PREQ_IE_TTL(preq_elem);
671 lifetime = PREQ_IE_LIFETIME(preq_elem);
672 if (ttl <= 1) {
673 ifmsh->mshstats.dropped_frames_ttl++;
674 return;
675 }
676 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
677 --ttl;
678 preq_id = PREQ_IE_PREQ_ID(preq_elem);
679 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
680 da = (mpath && mpath->is_root) ?
681 mpath->rann_snd_addr : broadcast_addr;
682
683 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
684 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
685 target_sn = PREQ_IE_TARGET_SN(preq_elem);
686 }
687
688 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
689 orig_sn, target_flags, target_addr,
690 target_sn, da, hopcount, ttl, lifetime,
691 orig_metric, preq_id, sdata);
692 if (!is_multicast_ether_addr(da))
693 ifmsh->mshstats.fwded_unicast++;
694 else
695 ifmsh->mshstats.fwded_mcast++;
696 ifmsh->mshstats.fwded_frames++;
697 }
698 }
699
700
701 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)702 next_hop_deref_protected(struct mesh_path *mpath)
703 {
704 return rcu_dereference_protected(mpath->next_hop,
705 lockdep_is_held(&mpath->state_lock));
706 }
707
708
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)709 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
710 struct ieee80211_mgmt *mgmt,
711 const u8 *prep_elem, u32 metric)
712 {
713 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
714 struct mesh_path *mpath;
715 const u8 *target_addr, *orig_addr;
716 u8 ttl, hopcount, flags;
717 u8 next_hop[ETH_ALEN];
718 u32 target_sn, orig_sn, lifetime;
719
720 mhwmp_dbg(sdata, "received PREP from %pM\n",
721 PREP_IE_TARGET_ADDR(prep_elem));
722
723 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
724 if (ether_addr_equal(orig_addr, sdata->vif.addr))
725 /* destination, no forwarding required */
726 return;
727
728 if (!ifmsh->mshcfg.dot11MeshForwarding)
729 return;
730
731 ttl = PREP_IE_TTL(prep_elem);
732 if (ttl <= 1) {
733 sdata->u.mesh.mshstats.dropped_frames_ttl++;
734 return;
735 }
736
737 rcu_read_lock();
738 mpath = mesh_path_lookup(sdata, orig_addr);
739 if (mpath)
740 spin_lock_bh(&mpath->state_lock);
741 else
742 goto fail;
743 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
744 spin_unlock_bh(&mpath->state_lock);
745 goto fail;
746 }
747 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
748 spin_unlock_bh(&mpath->state_lock);
749 --ttl;
750 flags = PREP_IE_FLAGS(prep_elem);
751 lifetime = PREP_IE_LIFETIME(prep_elem);
752 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
753 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
754 target_sn = PREP_IE_TARGET_SN(prep_elem);
755 orig_sn = PREP_IE_ORIG_SN(prep_elem);
756
757 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
758 target_addr, target_sn, next_hop, hopcount,
759 ttl, lifetime, metric, 0, sdata);
760 rcu_read_unlock();
761
762 sdata->u.mesh.mshstats.fwded_unicast++;
763 sdata->u.mesh.mshstats.fwded_frames++;
764 return;
765
766 fail:
767 rcu_read_unlock();
768 sdata->u.mesh.mshstats.dropped_frames_no_route++;
769 }
770
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)771 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
772 struct ieee80211_mgmt *mgmt,
773 const u8 *perr_elem)
774 {
775 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
776 struct mesh_path *mpath;
777 u8 ttl;
778 const u8 *ta, *target_addr;
779 u32 target_sn;
780 u16 target_rcode;
781
782 ta = mgmt->sa;
783 ttl = PERR_IE_TTL(perr_elem);
784 if (ttl <= 1) {
785 ifmsh->mshstats.dropped_frames_ttl++;
786 return;
787 }
788 ttl--;
789 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
790 target_sn = PERR_IE_TARGET_SN(perr_elem);
791 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
792
793 rcu_read_lock();
794 mpath = mesh_path_lookup(sdata, target_addr);
795 if (mpath) {
796 struct sta_info *sta;
797
798 spin_lock_bh(&mpath->state_lock);
799 sta = next_hop_deref_protected(mpath);
800 if (mpath->flags & MESH_PATH_ACTIVE &&
801 ether_addr_equal(ta, sta->sta.addr) &&
802 !(mpath->flags & MESH_PATH_FIXED) &&
803 (!(mpath->flags & MESH_PATH_SN_VALID) ||
804 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
805 mpath->flags &= ~MESH_PATH_ACTIVE;
806 if (target_sn != 0)
807 mpath->sn = target_sn;
808 else
809 mpath->sn += 1;
810 spin_unlock_bh(&mpath->state_lock);
811 if (!ifmsh->mshcfg.dot11MeshForwarding)
812 goto endperr;
813 mesh_path_error_tx(sdata, ttl, target_addr,
814 target_sn, target_rcode,
815 broadcast_addr);
816 } else
817 spin_unlock_bh(&mpath->state_lock);
818 }
819 endperr:
820 rcu_read_unlock();
821 }
822
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)823 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
824 struct ieee80211_mgmt *mgmt,
825 const struct ieee80211_rann_ie *rann)
826 {
827 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
828 struct ieee80211_local *local = sdata->local;
829 struct sta_info *sta;
830 struct mesh_path *mpath;
831 u8 ttl, flags, hopcount;
832 const u8 *orig_addr;
833 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
834 bool root_is_gate;
835
836 ttl = rann->rann_ttl;
837 flags = rann->rann_flags;
838 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
839 orig_addr = rann->rann_addr;
840 orig_sn = le32_to_cpu(rann->rann_seq);
841 interval = le32_to_cpu(rann->rann_interval);
842 hopcount = rann->rann_hopcount;
843 hopcount++;
844 orig_metric = le32_to_cpu(rann->rann_metric);
845
846 /* Ignore our own RANNs */
847 if (ether_addr_equal(orig_addr, sdata->vif.addr))
848 return;
849
850 mhwmp_dbg(sdata,
851 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
852 orig_addr, mgmt->sa, root_is_gate);
853
854 rcu_read_lock();
855 sta = sta_info_get(sdata, mgmt->sa);
856 if (!sta) {
857 rcu_read_unlock();
858 return;
859 }
860
861 last_hop_metric = airtime_link_metric_get(local, sta);
862 new_metric = orig_metric + last_hop_metric;
863 if (new_metric < orig_metric)
864 new_metric = MAX_METRIC;
865
866 mpath = mesh_path_lookup(sdata, orig_addr);
867 if (!mpath) {
868 mpath = mesh_path_add(sdata, orig_addr);
869 if (IS_ERR(mpath)) {
870 rcu_read_unlock();
871 sdata->u.mesh.mshstats.dropped_frames_no_route++;
872 return;
873 }
874 }
875
876 if (!(SN_LT(mpath->sn, orig_sn)) &&
877 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
878 rcu_read_unlock();
879 return;
880 }
881
882 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
883 (time_after(jiffies, mpath->last_preq_to_root +
884 root_path_confirmation_jiffies(sdata)) ||
885 time_before(jiffies, mpath->last_preq_to_root))) &&
886 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
887 mhwmp_dbg(sdata,
888 "time to refresh root mpath %pM\n",
889 orig_addr);
890 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
891 mpath->last_preq_to_root = jiffies;
892 }
893
894 mpath->sn = orig_sn;
895 mpath->rann_metric = new_metric;
896 mpath->is_root = true;
897 /* Recording RANNs sender address to send individually
898 * addressed PREQs destined for root mesh STA */
899 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
900
901 if (root_is_gate)
902 mesh_path_add_gate(mpath);
903
904 if (ttl <= 1) {
905 ifmsh->mshstats.dropped_frames_ttl++;
906 rcu_read_unlock();
907 return;
908 }
909 ttl--;
910
911 if (ifmsh->mshcfg.dot11MeshForwarding) {
912 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
913 orig_sn, 0, NULL, 0, broadcast_addr,
914 hopcount, ttl, interval,
915 new_metric, 0, sdata);
916 }
917
918 rcu_read_unlock();
919 }
920
921
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)922 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
923 struct ieee80211_mgmt *mgmt, size_t len)
924 {
925 struct ieee802_11_elems *elems;
926 size_t baselen;
927 u32 path_metric;
928 struct sta_info *sta;
929
930 /* need action_code */
931 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
932 return;
933
934 rcu_read_lock();
935 sta = sta_info_get(sdata, mgmt->sa);
936 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
937 rcu_read_unlock();
938 return;
939 }
940 rcu_read_unlock();
941
942 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
943 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
944 len - baselen, false, NULL);
945 if (!elems)
946 return;
947
948 if (elems->preq) {
949 if (elems->preq_len != 37)
950 /* Right now we support just 1 destination and no AE */
951 goto free;
952 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
953 MPATH_PREQ);
954 if (path_metric)
955 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
956 path_metric);
957 }
958 if (elems->prep) {
959 if (elems->prep_len != 31)
960 /* Right now we support no AE */
961 goto free;
962 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
963 MPATH_PREP);
964 if (path_metric)
965 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
966 path_metric);
967 }
968 if (elems->perr) {
969 if (elems->perr_len != 15)
970 /* Right now we support only one destination per PERR */
971 goto free;
972 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
973 }
974 if (elems->rann)
975 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
976 free:
977 kfree(elems);
978 }
979
980 /**
981 * mesh_queue_preq - queue a PREQ to a given destination
982 *
983 * @mpath: mesh path to discover
984 * @flags: special attributes of the PREQ to be sent
985 *
986 * Locking: the function must be called from within a rcu read lock block.
987 *
988 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)989 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
990 {
991 struct ieee80211_sub_if_data *sdata = mpath->sdata;
992 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
993 struct mesh_preq_queue *preq_node;
994
995 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
996 if (!preq_node) {
997 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
998 return;
999 }
1000
1001 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1002 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
1003 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1004 kfree(preq_node);
1005 if (printk_ratelimit())
1006 mhwmp_dbg(sdata, "PREQ node queue full\n");
1007 return;
1008 }
1009
1010 spin_lock(&mpath->state_lock);
1011 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1012 spin_unlock(&mpath->state_lock);
1013 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1014 kfree(preq_node);
1015 return;
1016 }
1017
1018 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1019 preq_node->flags = flags;
1020
1021 mpath->flags |= MESH_PATH_REQ_QUEUED;
1022 spin_unlock(&mpath->state_lock);
1023
1024 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1025 ++ifmsh->preq_queue_len;
1026 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1027
1028 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1029 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1030
1031 else if (time_before(jiffies, ifmsh->last_preq)) {
1032 /* avoid long wait if did not send preqs for a long time
1033 * and jiffies wrapped around
1034 */
1035 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1036 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1037 } else
1038 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1039 min_preq_int_jiff(sdata));
1040 }
1041
1042 /**
1043 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1044 *
1045 * @sdata: local mesh subif
1046 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1047 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1048 {
1049 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1050 struct mesh_preq_queue *preq_node;
1051 struct mesh_path *mpath;
1052 u8 ttl, target_flags = 0;
1053 const u8 *da;
1054 u32 lifetime;
1055
1056 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1057 if (!ifmsh->preq_queue_len ||
1058 time_before(jiffies, ifmsh->last_preq +
1059 min_preq_int_jiff(sdata))) {
1060 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1061 return;
1062 }
1063
1064 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1065 struct mesh_preq_queue, list);
1066 list_del(&preq_node->list);
1067 --ifmsh->preq_queue_len;
1068 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1069
1070 rcu_read_lock();
1071 mpath = mesh_path_lookup(sdata, preq_node->dst);
1072 if (!mpath)
1073 goto enddiscovery;
1074
1075 spin_lock_bh(&mpath->state_lock);
1076 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1077 spin_unlock_bh(&mpath->state_lock);
1078 goto enddiscovery;
1079 }
1080 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1081 if (preq_node->flags & PREQ_Q_F_START) {
1082 if (mpath->flags & MESH_PATH_RESOLVING) {
1083 spin_unlock_bh(&mpath->state_lock);
1084 goto enddiscovery;
1085 } else {
1086 mpath->flags &= ~MESH_PATH_RESOLVED;
1087 mpath->flags |= MESH_PATH_RESOLVING;
1088 mpath->discovery_retries = 0;
1089 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1090 }
1091 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1092 mpath->flags & MESH_PATH_RESOLVED) {
1093 mpath->flags &= ~MESH_PATH_RESOLVING;
1094 spin_unlock_bh(&mpath->state_lock);
1095 goto enddiscovery;
1096 }
1097
1098 ifmsh->last_preq = jiffies;
1099
1100 if (time_after(jiffies, ifmsh->last_sn_update +
1101 net_traversal_jiffies(sdata)) ||
1102 time_before(jiffies, ifmsh->last_sn_update)) {
1103 ++ifmsh->sn;
1104 sdata->u.mesh.last_sn_update = jiffies;
1105 }
1106 lifetime = default_lifetime(sdata);
1107 ttl = sdata->u.mesh.mshcfg.element_ttl;
1108 if (ttl == 0) {
1109 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1110 spin_unlock_bh(&mpath->state_lock);
1111 goto enddiscovery;
1112 }
1113
1114 if (preq_node->flags & PREQ_Q_F_REFRESH)
1115 target_flags |= IEEE80211_PREQ_TO_FLAG;
1116 else
1117 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1118
1119 spin_unlock_bh(&mpath->state_lock);
1120 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1121 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1122 target_flags, mpath->dst, mpath->sn, da, 0,
1123 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1124
1125 spin_lock_bh(&mpath->state_lock);
1126 if (!(mpath->flags & MESH_PATH_DELETED))
1127 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1128 spin_unlock_bh(&mpath->state_lock);
1129
1130 enddiscovery:
1131 rcu_read_unlock();
1132 kfree(preq_node);
1133 }
1134
1135 /**
1136 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1137 *
1138 * @skb: 802.11 frame to be sent
1139 * @sdata: network subif the frame will be sent through
1140 *
1141 * Lookup next hop for given skb and start path discovery if no
1142 * forwarding information is found.
1143 *
1144 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1145 * skb is freed here if no mpath could be allocated.
1146 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1147 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1148 struct sk_buff *skb)
1149 {
1150 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1151 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1152 struct mesh_path *mpath;
1153 struct sk_buff *skb_to_free = NULL;
1154 u8 *target_addr = hdr->addr3;
1155
1156 /* Nulls are only sent to peers for PS and should be pre-addressed */
1157 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1158 return 0;
1159
1160 /* Allow injected packets to bypass mesh routing */
1161 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1162 return 0;
1163
1164 if (!mesh_nexthop_lookup(sdata, skb))
1165 return 0;
1166
1167 /* no nexthop found, start resolving */
1168 mpath = mesh_path_lookup(sdata, target_addr);
1169 if (!mpath) {
1170 mpath = mesh_path_add(sdata, target_addr);
1171 if (IS_ERR(mpath)) {
1172 mesh_path_discard_frame(sdata, skb);
1173 return PTR_ERR(mpath);
1174 }
1175 }
1176
1177 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1178 mesh_path_sel_is_hwmp(sdata))
1179 mesh_queue_preq(mpath, PREQ_Q_F_START);
1180
1181 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1182 skb_to_free = skb_dequeue(&mpath->frame_queue);
1183
1184 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1185 ieee80211_set_qos_hdr(sdata, skb);
1186 skb_queue_tail(&mpath->frame_queue, skb);
1187 if (skb_to_free)
1188 mesh_path_discard_frame(sdata, skb_to_free);
1189
1190 return -ENOENT;
1191 }
1192
1193 /**
1194 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1195 * @skb: 802.11 frame to be sent
1196 * @sdata: network subif the frame will be sent through
1197 *
1198 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1199 * And if so, set the RA (addr1) to it to transmit to this node directly,
1200 * avoiding PREQ/PREP path discovery.
1201 *
1202 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1203 */
mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1204 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1205 struct sk_buff *skb)
1206 {
1207 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1208 struct sta_info *sta;
1209
1210 if (is_multicast_ether_addr(hdr->addr1))
1211 return -ENOENT;
1212
1213 rcu_read_lock();
1214 sta = sta_info_get(sdata, hdr->addr3);
1215
1216 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1217 rcu_read_unlock();
1218 return -ENOENT;
1219 }
1220 rcu_read_unlock();
1221
1222 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1223 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1224 return 0;
1225 }
1226
mesh_path_refresh(struct ieee80211_sub_if_data * sdata,struct mesh_path * mpath,const u8 * addr)1227 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata,
1228 struct mesh_path *mpath, const u8 *addr)
1229 {
1230 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED |
1231 MESH_PATH_RESOLVING))
1232 return;
1233
1234 if (time_after(jiffies,
1235 mpath->exp_time -
1236 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1237 (!addr || ether_addr_equal(sdata->vif.addr, addr)))
1238 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1239 }
1240
1241 /**
1242 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1243 * this function is considered "using" the associated mpath, so preempt a path
1244 * refresh if this mpath expires soon.
1245 *
1246 * @skb: 802.11 frame to be sent
1247 * @sdata: network subif the frame will be sent through
1248 *
1249 * Returns: 0 if the next hop was found. Nonzero otherwise.
1250 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1251 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1252 struct sk_buff *skb)
1253 {
1254 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1255 struct mesh_path *mpath;
1256 struct sta_info *next_hop;
1257 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1258 u8 *target_addr = hdr->addr3;
1259
1260 if (ifmsh->mshcfg.dot11MeshNolearn &&
1261 !mesh_nexthop_lookup_nolearn(sdata, skb))
1262 return 0;
1263
1264 mpath = mesh_path_lookup(sdata, target_addr);
1265 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1266 return -ENOENT;
1267
1268 mesh_path_refresh(sdata, mpath, hdr->addr4);
1269
1270 next_hop = rcu_dereference(mpath->next_hop);
1271 if (next_hop) {
1272 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1273 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1274 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1275 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT))
1276 mesh_fast_tx_cache(sdata, skb, mpath);
1277 return 0;
1278 }
1279
1280 return -ENOENT;
1281 }
1282
mesh_path_timer(struct timer_list * t)1283 void mesh_path_timer(struct timer_list *t)
1284 {
1285 struct mesh_path *mpath = from_timer(mpath, t, timer);
1286 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1287 int ret;
1288
1289 if (sdata->local->quiescing)
1290 return;
1291
1292 spin_lock_bh(&mpath->state_lock);
1293 if (mpath->flags & MESH_PATH_RESOLVED ||
1294 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1295 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1296 spin_unlock_bh(&mpath->state_lock);
1297 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1298 ++mpath->discovery_retries;
1299 mpath->discovery_timeout *= 2;
1300 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1301 spin_unlock_bh(&mpath->state_lock);
1302 mesh_queue_preq(mpath, 0);
1303 } else {
1304 mpath->flags &= ~(MESH_PATH_RESOLVING |
1305 MESH_PATH_RESOLVED |
1306 MESH_PATH_REQ_QUEUED);
1307 mpath->exp_time = jiffies;
1308 spin_unlock_bh(&mpath->state_lock);
1309 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1310 ret = mesh_path_send_to_gates(mpath);
1311 if (ret)
1312 mhwmp_dbg(sdata, "no gate was reachable\n");
1313 } else
1314 mesh_path_flush_pending(mpath);
1315 }
1316 }
1317
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1318 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1319 {
1320 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1321 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1322 u8 flags, target_flags = 0;
1323
1324 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1325 ? RANN_FLAG_IS_GATE : 0;
1326
1327 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1328 case IEEE80211_PROACTIVE_RANN:
1329 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1330 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1331 0, ifmsh->mshcfg.element_ttl,
1332 interval, 0, 0, sdata);
1333 break;
1334 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1335 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1336 fallthrough;
1337 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1338 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1339 target_flags |= IEEE80211_PREQ_TO_FLAG |
1340 IEEE80211_PREQ_USN_FLAG;
1341 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1342 ++ifmsh->sn, target_flags,
1343 (u8 *) broadcast_addr, 0, broadcast_addr,
1344 0, ifmsh->mshcfg.element_ttl, interval,
1345 0, ifmsh->preq_id++, sdata);
1346 break;
1347 default:
1348 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1349 return;
1350 }
1351 }
1352