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 /* Check that the first metric is at least 10% better than the second one */
is_metric_better(u32 x,u32 y)369 static bool is_metric_better(u32 x, u32 y)
370 {
371 return (x < y) && (x < (y - x / 10));
372 }
373
374 /**
375 * hwmp_route_info_get - Update routing info to originator and transmitter
376 *
377 * @sdata: local mesh subif
378 * @mgmt: mesh management frame
379 * @hwmp_ie: hwmp information element (PREP or PREQ)
380 * @action: type of hwmp ie
381 *
382 * This function updates the path routing information to the originator and the
383 * transmitter of a HWMP PREQ or PREP frame.
384 *
385 * Returns: metric to frame originator or 0 if the frame should not be further
386 * processed
387 *
388 * Notes: this function is the only place (besides user-provided info) where
389 * path routing information is updated.
390 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)391 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
392 struct ieee80211_mgmt *mgmt,
393 const u8 *hwmp_ie, enum mpath_frame_type action)
394 {
395 struct ieee80211_local *local = sdata->local;
396 struct mesh_path *mpath;
397 struct sta_info *sta;
398 bool fresh_info;
399 const u8 *orig_addr, *ta;
400 u32 orig_sn, orig_metric;
401 unsigned long orig_lifetime, exp_time;
402 u32 last_hop_metric, new_metric;
403 bool flush_mpath = false;
404 bool process = true;
405 u8 hopcount;
406
407 rcu_read_lock();
408 sta = sta_info_get(sdata, mgmt->sa);
409 if (!sta) {
410 rcu_read_unlock();
411 return 0;
412 }
413
414 last_hop_metric = airtime_link_metric_get(local, sta);
415 /* Update and check originator routing info */
416 fresh_info = true;
417
418 switch (action) {
419 case MPATH_PREQ:
420 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
421 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
422 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
423 orig_metric = PREQ_IE_METRIC(hwmp_ie);
424 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
425 break;
426 case MPATH_PREP:
427 /* Originator here refers to the MP that was the target in the
428 * Path Request. We divert from the nomenclature in the draft
429 * so that we can easily use a single function to gather path
430 * information from both PREQ and PREP frames.
431 */
432 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
433 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
434 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
435 orig_metric = PREP_IE_METRIC(hwmp_ie);
436 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
437 break;
438 default:
439 rcu_read_unlock();
440 return 0;
441 }
442 new_metric = orig_metric + last_hop_metric;
443 if (new_metric < orig_metric)
444 new_metric = MAX_METRIC;
445 exp_time = TU_TO_EXP_TIME(orig_lifetime);
446
447 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
448 /* This MP is the originator, we are not interested in this
449 * frame, except for updating transmitter's path info.
450 */
451 process = false;
452 fresh_info = false;
453 } else {
454 mpath = mesh_path_lookup(sdata, orig_addr);
455 if (mpath) {
456 spin_lock_bh(&mpath->state_lock);
457 if (mpath->flags & MESH_PATH_FIXED)
458 fresh_info = false;
459 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
460 (mpath->flags & MESH_PATH_SN_VALID)) {
461 if (SN_GT(mpath->sn, orig_sn) ||
462 (mpath->sn == orig_sn &&
463 (rcu_access_pointer(mpath->next_hop) !=
464 sta ?
465 !is_metric_better(new_metric, mpath->metric) :
466 new_metric >= mpath->metric))) {
467 process = false;
468 fresh_info = false;
469 }
470 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
471 bool have_sn, newer_sn, bounced;
472
473 have_sn = mpath->flags & MESH_PATH_SN_VALID;
474 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
475 bounced = have_sn &&
476 (SN_DELTA(orig_sn, mpath->sn) >
477 MAX_SANE_SN_DELTA);
478
479 if (!have_sn || newer_sn) {
480 /* if SN is newer than what we had
481 * then we can take it */;
482 } else if (bounced) {
483 /* if SN is way different than what
484 * we had then assume the other side
485 * rebooted or restarted */;
486 } else {
487 process = false;
488 fresh_info = false;
489 }
490 }
491 } else {
492 mpath = mesh_path_add(sdata, orig_addr);
493 if (IS_ERR(mpath)) {
494 rcu_read_unlock();
495 return 0;
496 }
497 spin_lock_bh(&mpath->state_lock);
498 }
499
500 if (fresh_info) {
501 if (rcu_access_pointer(mpath->next_hop) != sta) {
502 mpath->path_change_count++;
503 flush_mpath = true;
504 }
505 mesh_path_assign_nexthop(mpath, sta);
506 mpath->flags |= MESH_PATH_SN_VALID;
507 mpath->metric = new_metric;
508 mpath->sn = orig_sn;
509 mpath->exp_time = time_after(mpath->exp_time, exp_time)
510 ? mpath->exp_time : exp_time;
511 mpath->hop_count = hopcount;
512 mesh_path_activate(mpath);
513 spin_unlock_bh(&mpath->state_lock);
514 if (flush_mpath)
515 mesh_fast_tx_flush_mpath(mpath);
516 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
517 /* init it at a low value - 0 start is tricky */
518 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
519 mesh_path_tx_pending(mpath);
520 /* draft says preq_id should be saved to, but there does
521 * not seem to be any use for it, skipping by now
522 */
523 } else
524 spin_unlock_bh(&mpath->state_lock);
525 }
526
527 /* Update and check transmitter routing info */
528 ta = mgmt->sa;
529 if (ether_addr_equal(orig_addr, ta))
530 fresh_info = false;
531 else {
532 fresh_info = true;
533
534 mpath = mesh_path_lookup(sdata, ta);
535 if (mpath) {
536 spin_lock_bh(&mpath->state_lock);
537 if ((mpath->flags & MESH_PATH_FIXED) ||
538 ((mpath->flags & MESH_PATH_ACTIVE) &&
539 ((rcu_access_pointer(mpath->next_hop) != sta ?
540 !is_metric_better(last_hop_metric, mpath->metric) :
541 last_hop_metric > mpath->metric))))
542 fresh_info = false;
543 } else {
544 mpath = mesh_path_add(sdata, ta);
545 if (IS_ERR(mpath)) {
546 rcu_read_unlock();
547 return 0;
548 }
549 spin_lock_bh(&mpath->state_lock);
550 }
551
552 if (fresh_info) {
553 if (rcu_access_pointer(mpath->next_hop) != sta) {
554 mpath->path_change_count++;
555 flush_mpath = true;
556 }
557 mesh_path_assign_nexthop(mpath, sta);
558 mpath->metric = last_hop_metric;
559 mpath->exp_time = time_after(mpath->exp_time, exp_time)
560 ? mpath->exp_time : exp_time;
561 mpath->hop_count = 1;
562 mesh_path_activate(mpath);
563 spin_unlock_bh(&mpath->state_lock);
564 if (flush_mpath)
565 mesh_fast_tx_flush_mpath(mpath);
566 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
567 /* init it at a low value - 0 start is tricky */
568 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
569 mesh_path_tx_pending(mpath);
570 } else
571 spin_unlock_bh(&mpath->state_lock);
572 }
573
574 rcu_read_unlock();
575
576 return process ? new_metric : 0;
577 }
578
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)579 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
580 struct ieee80211_mgmt *mgmt,
581 const u8 *preq_elem, u32 orig_metric)
582 {
583 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
584 struct mesh_path *mpath = NULL;
585 const u8 *target_addr, *orig_addr;
586 const u8 *da;
587 u8 target_flags, ttl, flags;
588 u32 orig_sn, target_sn, lifetime, target_metric = 0;
589 bool reply = false;
590 bool forward = true;
591 bool root_is_gate;
592
593 /* Update target SN, if present */
594 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
595 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
596 target_sn = PREQ_IE_TARGET_SN(preq_elem);
597 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
598 target_flags = PREQ_IE_TARGET_F(preq_elem);
599 /* Proactive PREQ gate announcements */
600 flags = PREQ_IE_FLAGS(preq_elem);
601 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
602
603 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
604
605 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
606 mhwmp_dbg(sdata, "PREQ is for us\n");
607 forward = false;
608 reply = true;
609 target_metric = 0;
610
611 if (SN_GT(target_sn, ifmsh->sn))
612 ifmsh->sn = target_sn;
613
614 if (time_after(jiffies, ifmsh->last_sn_update +
615 net_traversal_jiffies(sdata)) ||
616 time_before(jiffies, ifmsh->last_sn_update)) {
617 ++ifmsh->sn;
618 ifmsh->last_sn_update = jiffies;
619 }
620 target_sn = ifmsh->sn;
621 } else if (is_broadcast_ether_addr(target_addr) &&
622 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
623 rcu_read_lock();
624 mpath = mesh_path_lookup(sdata, orig_addr);
625 if (mpath) {
626 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
627 reply = true;
628 target_addr = sdata->vif.addr;
629 target_sn = ++ifmsh->sn;
630 target_metric = 0;
631 ifmsh->last_sn_update = jiffies;
632 }
633 if (root_is_gate)
634 mesh_path_add_gate(mpath);
635 }
636 rcu_read_unlock();
637 } else {
638 rcu_read_lock();
639 mpath = mesh_path_lookup(sdata, target_addr);
640 if (mpath) {
641 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
642 SN_LT(mpath->sn, target_sn)) {
643 mpath->sn = target_sn;
644 mpath->flags |= MESH_PATH_SN_VALID;
645 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
646 (mpath->flags & MESH_PATH_ACTIVE)) {
647 reply = true;
648 target_metric = mpath->metric;
649 target_sn = mpath->sn;
650 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
651 target_flags |= IEEE80211_PREQ_TO_FLAG;
652 }
653 }
654 rcu_read_unlock();
655 }
656
657 if (reply) {
658 lifetime = PREQ_IE_LIFETIME(preq_elem);
659 ttl = ifmsh->mshcfg.element_ttl;
660 if (ttl != 0) {
661 mhwmp_dbg(sdata, "replying to the PREQ\n");
662 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
663 orig_sn, 0, target_addr,
664 target_sn, mgmt->sa, 0, ttl,
665 lifetime, target_metric, 0,
666 sdata);
667 } else {
668 ifmsh->mshstats.dropped_frames_ttl++;
669 }
670 }
671
672 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
673 u32 preq_id;
674 u8 hopcount;
675
676 ttl = PREQ_IE_TTL(preq_elem);
677 lifetime = PREQ_IE_LIFETIME(preq_elem);
678 if (ttl <= 1) {
679 ifmsh->mshstats.dropped_frames_ttl++;
680 return;
681 }
682 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
683 --ttl;
684 preq_id = PREQ_IE_PREQ_ID(preq_elem);
685 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
686 da = (mpath && mpath->is_root) ?
687 mpath->rann_snd_addr : broadcast_addr;
688
689 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
690 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
691 target_sn = PREQ_IE_TARGET_SN(preq_elem);
692 }
693
694 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
695 orig_sn, target_flags, target_addr,
696 target_sn, da, hopcount, ttl, lifetime,
697 orig_metric, preq_id, sdata);
698 if (!is_multicast_ether_addr(da))
699 ifmsh->mshstats.fwded_unicast++;
700 else
701 ifmsh->mshstats.fwded_mcast++;
702 ifmsh->mshstats.fwded_frames++;
703 }
704 }
705
706
707 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)708 next_hop_deref_protected(struct mesh_path *mpath)
709 {
710 return rcu_dereference_protected(mpath->next_hop,
711 lockdep_is_held(&mpath->state_lock));
712 }
713
714
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)715 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
716 struct ieee80211_mgmt *mgmt,
717 const u8 *prep_elem, u32 metric)
718 {
719 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
720 struct mesh_path *mpath;
721 const u8 *target_addr, *orig_addr;
722 u8 ttl, hopcount, flags;
723 u8 next_hop[ETH_ALEN];
724 u32 target_sn, orig_sn, lifetime;
725
726 mhwmp_dbg(sdata, "received PREP from %pM\n",
727 PREP_IE_TARGET_ADDR(prep_elem));
728
729 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
730 if (ether_addr_equal(orig_addr, sdata->vif.addr))
731 /* destination, no forwarding required */
732 return;
733
734 if (!ifmsh->mshcfg.dot11MeshForwarding)
735 return;
736
737 ttl = PREP_IE_TTL(prep_elem);
738 if (ttl <= 1) {
739 sdata->u.mesh.mshstats.dropped_frames_ttl++;
740 return;
741 }
742
743 rcu_read_lock();
744 mpath = mesh_path_lookup(sdata, orig_addr);
745 if (mpath)
746 spin_lock_bh(&mpath->state_lock);
747 else
748 goto fail;
749 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
750 spin_unlock_bh(&mpath->state_lock);
751 goto fail;
752 }
753 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
754 spin_unlock_bh(&mpath->state_lock);
755 --ttl;
756 flags = PREP_IE_FLAGS(prep_elem);
757 lifetime = PREP_IE_LIFETIME(prep_elem);
758 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
759 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
760 target_sn = PREP_IE_TARGET_SN(prep_elem);
761 orig_sn = PREP_IE_ORIG_SN(prep_elem);
762
763 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
764 target_addr, target_sn, next_hop, hopcount,
765 ttl, lifetime, metric, 0, sdata);
766 rcu_read_unlock();
767
768 sdata->u.mesh.mshstats.fwded_unicast++;
769 sdata->u.mesh.mshstats.fwded_frames++;
770 return;
771
772 fail:
773 rcu_read_unlock();
774 sdata->u.mesh.mshstats.dropped_frames_no_route++;
775 }
776
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)777 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
778 struct ieee80211_mgmt *mgmt,
779 const u8 *perr_elem)
780 {
781 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
782 struct mesh_path *mpath;
783 u8 ttl;
784 const u8 *ta, *target_addr;
785 u32 target_sn;
786 u16 target_rcode;
787
788 ta = mgmt->sa;
789 ttl = PERR_IE_TTL(perr_elem);
790 if (ttl <= 1) {
791 ifmsh->mshstats.dropped_frames_ttl++;
792 return;
793 }
794 ttl--;
795 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
796 target_sn = PERR_IE_TARGET_SN(perr_elem);
797 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
798
799 rcu_read_lock();
800 mpath = mesh_path_lookup(sdata, target_addr);
801 if (mpath) {
802 struct sta_info *sta;
803
804 spin_lock_bh(&mpath->state_lock);
805 sta = next_hop_deref_protected(mpath);
806 if (mpath->flags & MESH_PATH_ACTIVE &&
807 ether_addr_equal(ta, sta->sta.addr) &&
808 !(mpath->flags & MESH_PATH_FIXED) &&
809 (!(mpath->flags & MESH_PATH_SN_VALID) ||
810 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
811 mpath->flags &= ~MESH_PATH_ACTIVE;
812 if (target_sn != 0)
813 mpath->sn = target_sn;
814 else
815 mpath->sn += 1;
816 spin_unlock_bh(&mpath->state_lock);
817 if (!ifmsh->mshcfg.dot11MeshForwarding)
818 goto endperr;
819 mesh_path_error_tx(sdata, ttl, target_addr,
820 target_sn, target_rcode,
821 broadcast_addr);
822 } else
823 spin_unlock_bh(&mpath->state_lock);
824 }
825 endperr:
826 rcu_read_unlock();
827 }
828
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)829 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
830 struct ieee80211_mgmt *mgmt,
831 const struct ieee80211_rann_ie *rann)
832 {
833 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
834 struct ieee80211_local *local = sdata->local;
835 struct sta_info *sta;
836 struct mesh_path *mpath;
837 u8 ttl, flags, hopcount;
838 const u8 *orig_addr;
839 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
840 bool root_is_gate;
841
842 ttl = rann->rann_ttl;
843 flags = rann->rann_flags;
844 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
845 orig_addr = rann->rann_addr;
846 orig_sn = le32_to_cpu(rann->rann_seq);
847 interval = le32_to_cpu(rann->rann_interval);
848 hopcount = rann->rann_hopcount;
849 hopcount++;
850 orig_metric = le32_to_cpu(rann->rann_metric);
851
852 /* Ignore our own RANNs */
853 if (ether_addr_equal(orig_addr, sdata->vif.addr))
854 return;
855
856 mhwmp_dbg(sdata,
857 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
858 orig_addr, mgmt->sa, root_is_gate);
859
860 rcu_read_lock();
861 sta = sta_info_get(sdata, mgmt->sa);
862 if (!sta) {
863 rcu_read_unlock();
864 return;
865 }
866
867 last_hop_metric = airtime_link_metric_get(local, sta);
868 new_metric = orig_metric + last_hop_metric;
869 if (new_metric < orig_metric)
870 new_metric = MAX_METRIC;
871
872 mpath = mesh_path_lookup(sdata, orig_addr);
873 if (!mpath) {
874 mpath = mesh_path_add(sdata, orig_addr);
875 if (IS_ERR(mpath)) {
876 rcu_read_unlock();
877 sdata->u.mesh.mshstats.dropped_frames_no_route++;
878 return;
879 }
880 }
881
882 if (!(SN_LT(mpath->sn, orig_sn)) &&
883 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
884 rcu_read_unlock();
885 return;
886 }
887
888 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
889 (time_after(jiffies, mpath->last_preq_to_root +
890 root_path_confirmation_jiffies(sdata)) ||
891 time_before(jiffies, mpath->last_preq_to_root))) &&
892 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
893 mhwmp_dbg(sdata,
894 "time to refresh root mpath %pM\n",
895 orig_addr);
896 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
897 mpath->last_preq_to_root = jiffies;
898 }
899
900 mpath->sn = orig_sn;
901 mpath->rann_metric = new_metric;
902 mpath->is_root = true;
903 /* Recording RANNs sender address to send individually
904 * addressed PREQs destined for root mesh STA */
905 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
906
907 if (root_is_gate)
908 mesh_path_add_gate(mpath);
909
910 if (ttl <= 1) {
911 ifmsh->mshstats.dropped_frames_ttl++;
912 rcu_read_unlock();
913 return;
914 }
915 ttl--;
916
917 if (ifmsh->mshcfg.dot11MeshForwarding) {
918 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
919 orig_sn, 0, NULL, 0, broadcast_addr,
920 hopcount, ttl, interval,
921 new_metric, 0, sdata);
922 }
923
924 rcu_read_unlock();
925 }
926
927
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)928 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
929 struct ieee80211_mgmt *mgmt, size_t len)
930 {
931 struct ieee802_11_elems *elems;
932 size_t baselen;
933 u32 path_metric;
934 struct sta_info *sta;
935
936 /* need action_code */
937 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
938 return;
939
940 rcu_read_lock();
941 sta = sta_info_get(sdata, mgmt->sa);
942 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
943 rcu_read_unlock();
944 return;
945 }
946 rcu_read_unlock();
947
948 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
949 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
950 len - baselen, false, NULL);
951 if (!elems)
952 return;
953
954 if (elems->preq) {
955 if (elems->preq_len != 37)
956 /* Right now we support just 1 destination and no AE */
957 goto free;
958 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
959 MPATH_PREQ);
960 if (path_metric)
961 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
962 path_metric);
963 }
964 if (elems->prep) {
965 if (elems->prep_len != 31)
966 /* Right now we support no AE */
967 goto free;
968 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
969 MPATH_PREP);
970 if (path_metric)
971 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
972 path_metric);
973 }
974 if (elems->perr) {
975 if (elems->perr_len != 15)
976 /* Right now we support only one destination per PERR */
977 goto free;
978 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
979 }
980 if (elems->rann)
981 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
982 free:
983 kfree(elems);
984 }
985
986 /**
987 * mesh_queue_preq - queue a PREQ to a given destination
988 *
989 * @mpath: mesh path to discover
990 * @flags: special attributes of the PREQ to be sent
991 *
992 * Locking: the function must be called from within a rcu read lock block.
993 *
994 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)995 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
996 {
997 struct ieee80211_sub_if_data *sdata = mpath->sdata;
998 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
999 struct mesh_preq_queue *preq_node;
1000
1001 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
1002 if (!preq_node) {
1003 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
1004 return;
1005 }
1006
1007 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1008 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
1009 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1010 kfree(preq_node);
1011 if (printk_ratelimit())
1012 mhwmp_dbg(sdata, "PREQ node queue full\n");
1013 return;
1014 }
1015
1016 spin_lock(&mpath->state_lock);
1017 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1018 spin_unlock(&mpath->state_lock);
1019 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1020 kfree(preq_node);
1021 return;
1022 }
1023
1024 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1025 preq_node->flags = flags;
1026
1027 mpath->flags |= MESH_PATH_REQ_QUEUED;
1028 spin_unlock(&mpath->state_lock);
1029
1030 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1031 ++ifmsh->preq_queue_len;
1032 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1033
1034 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1035 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1036
1037 else if (time_before(jiffies, ifmsh->last_preq)) {
1038 /* avoid long wait if did not send preqs for a long time
1039 * and jiffies wrapped around
1040 */
1041 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1042 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1043 } else
1044 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1045 min_preq_int_jiff(sdata));
1046 }
1047
1048 /**
1049 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1050 *
1051 * @sdata: local mesh subif
1052 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1053 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1054 {
1055 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1056 struct mesh_preq_queue *preq_node;
1057 struct mesh_path *mpath;
1058 u8 ttl, target_flags = 0;
1059 const u8 *da;
1060 u32 lifetime;
1061
1062 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1063 if (!ifmsh->preq_queue_len ||
1064 time_before(jiffies, ifmsh->last_preq +
1065 min_preq_int_jiff(sdata))) {
1066 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1067 return;
1068 }
1069
1070 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1071 struct mesh_preq_queue, list);
1072 list_del(&preq_node->list);
1073 --ifmsh->preq_queue_len;
1074 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1075
1076 rcu_read_lock();
1077 mpath = mesh_path_lookup(sdata, preq_node->dst);
1078 if (!mpath)
1079 goto enddiscovery;
1080
1081 spin_lock_bh(&mpath->state_lock);
1082 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1083 spin_unlock_bh(&mpath->state_lock);
1084 goto enddiscovery;
1085 }
1086 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1087 if (preq_node->flags & PREQ_Q_F_START) {
1088 if (mpath->flags & MESH_PATH_RESOLVING) {
1089 spin_unlock_bh(&mpath->state_lock);
1090 goto enddiscovery;
1091 } else {
1092 mpath->flags &= ~MESH_PATH_RESOLVED;
1093 mpath->flags |= MESH_PATH_RESOLVING;
1094 mpath->discovery_retries = 0;
1095 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1096 }
1097 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1098 mpath->flags & MESH_PATH_RESOLVED) {
1099 mpath->flags &= ~MESH_PATH_RESOLVING;
1100 spin_unlock_bh(&mpath->state_lock);
1101 goto enddiscovery;
1102 }
1103
1104 ifmsh->last_preq = jiffies;
1105
1106 if (time_after(jiffies, ifmsh->last_sn_update +
1107 net_traversal_jiffies(sdata)) ||
1108 time_before(jiffies, ifmsh->last_sn_update)) {
1109 ++ifmsh->sn;
1110 sdata->u.mesh.last_sn_update = jiffies;
1111 }
1112 lifetime = default_lifetime(sdata);
1113 ttl = sdata->u.mesh.mshcfg.element_ttl;
1114 if (ttl == 0) {
1115 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1116 spin_unlock_bh(&mpath->state_lock);
1117 goto enddiscovery;
1118 }
1119
1120 if (preq_node->flags & PREQ_Q_F_REFRESH)
1121 target_flags |= IEEE80211_PREQ_TO_FLAG;
1122 else
1123 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1124
1125 spin_unlock_bh(&mpath->state_lock);
1126 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1127 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1128 target_flags, mpath->dst, mpath->sn, da, 0,
1129 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1130
1131 spin_lock_bh(&mpath->state_lock);
1132 if (!(mpath->flags & MESH_PATH_DELETED))
1133 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1134 spin_unlock_bh(&mpath->state_lock);
1135
1136 enddiscovery:
1137 rcu_read_unlock();
1138 kfree(preq_node);
1139 }
1140
1141 /**
1142 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1143 *
1144 * @skb: 802.11 frame to be sent
1145 * @sdata: network subif the frame will be sent through
1146 *
1147 * Lookup next hop for given skb and start path discovery if no
1148 * forwarding information is found.
1149 *
1150 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1151 * skb is freed here if no mpath could be allocated.
1152 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1153 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1154 struct sk_buff *skb)
1155 {
1156 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1157 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1158 struct mesh_path *mpath;
1159 struct sk_buff *skb_to_free = NULL;
1160 u8 *target_addr = hdr->addr3;
1161
1162 /* Nulls are only sent to peers for PS and should be pre-addressed */
1163 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1164 return 0;
1165
1166 /* Allow injected packets to bypass mesh routing */
1167 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1168 return 0;
1169
1170 if (!mesh_nexthop_lookup(sdata, skb))
1171 return 0;
1172
1173 /* no nexthop found, start resolving */
1174 mpath = mesh_path_lookup(sdata, target_addr);
1175 if (!mpath) {
1176 mpath = mesh_path_add(sdata, target_addr);
1177 if (IS_ERR(mpath)) {
1178 mesh_path_discard_frame(sdata, skb);
1179 return PTR_ERR(mpath);
1180 }
1181 }
1182
1183 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1184 mesh_path_sel_is_hwmp(sdata))
1185 mesh_queue_preq(mpath, PREQ_Q_F_START);
1186
1187 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1188 skb_to_free = skb_dequeue(&mpath->frame_queue);
1189
1190 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1191 ieee80211_set_qos_hdr(sdata, skb);
1192 skb_queue_tail(&mpath->frame_queue, skb);
1193 if (skb_to_free)
1194 mesh_path_discard_frame(sdata, skb_to_free);
1195
1196 return -ENOENT;
1197 }
1198
1199 /**
1200 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1201 * @skb: 802.11 frame to be sent
1202 * @sdata: network subif the frame will be sent through
1203 *
1204 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1205 * And if so, set the RA (addr1) to it to transmit to this node directly,
1206 * avoiding PREQ/PREP path discovery.
1207 *
1208 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1209 */
mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1210 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1211 struct sk_buff *skb)
1212 {
1213 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1214 struct sta_info *sta;
1215
1216 if (is_multicast_ether_addr(hdr->addr1))
1217 return -ENOENT;
1218
1219 rcu_read_lock();
1220 sta = sta_info_get(sdata, hdr->addr3);
1221
1222 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1223 rcu_read_unlock();
1224 return -ENOENT;
1225 }
1226 rcu_read_unlock();
1227
1228 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1229 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1230 return 0;
1231 }
1232
mesh_path_refresh(struct ieee80211_sub_if_data * sdata,struct mesh_path * mpath,const u8 * addr)1233 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata,
1234 struct mesh_path *mpath, const u8 *addr)
1235 {
1236 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED |
1237 MESH_PATH_RESOLVING))
1238 return;
1239
1240 if (time_after(jiffies,
1241 mpath->exp_time -
1242 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1243 (!addr || ether_addr_equal(sdata->vif.addr, addr)))
1244 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1245 }
1246
1247 /**
1248 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1249 * this function is considered "using" the associated mpath, so preempt a path
1250 * refresh if this mpath expires soon.
1251 *
1252 * @skb: 802.11 frame to be sent
1253 * @sdata: network subif the frame will be sent through
1254 *
1255 * Returns: 0 if the next hop was found. Nonzero otherwise.
1256 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1257 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1258 struct sk_buff *skb)
1259 {
1260 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1261 struct mesh_path *mpath;
1262 struct sta_info *next_hop;
1263 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1264 u8 *target_addr = hdr->addr3;
1265
1266 if (ifmsh->mshcfg.dot11MeshNolearn &&
1267 !mesh_nexthop_lookup_nolearn(sdata, skb))
1268 return 0;
1269
1270 mpath = mesh_path_lookup(sdata, target_addr);
1271 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1272 return -ENOENT;
1273
1274 mesh_path_refresh(sdata, mpath, hdr->addr4);
1275
1276 next_hop = rcu_dereference(mpath->next_hop);
1277 if (next_hop) {
1278 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1279 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1280 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1281 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT))
1282 mesh_fast_tx_cache(sdata, skb, mpath);
1283 return 0;
1284 }
1285
1286 return -ENOENT;
1287 }
1288
mesh_path_timer(struct timer_list * t)1289 void mesh_path_timer(struct timer_list *t)
1290 {
1291 struct mesh_path *mpath = from_timer(mpath, t, timer);
1292 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1293 int ret;
1294
1295 if (sdata->local->quiescing)
1296 return;
1297
1298 spin_lock_bh(&mpath->state_lock);
1299 if (mpath->flags & MESH_PATH_RESOLVED ||
1300 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1301 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1302 spin_unlock_bh(&mpath->state_lock);
1303 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1304 ++mpath->discovery_retries;
1305 mpath->discovery_timeout *= 2;
1306 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1307 spin_unlock_bh(&mpath->state_lock);
1308 mesh_queue_preq(mpath, 0);
1309 } else {
1310 mpath->flags &= ~(MESH_PATH_RESOLVING |
1311 MESH_PATH_RESOLVED |
1312 MESH_PATH_REQ_QUEUED);
1313 mpath->exp_time = jiffies;
1314 spin_unlock_bh(&mpath->state_lock);
1315 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1316 ret = mesh_path_send_to_gates(mpath);
1317 if (ret)
1318 mhwmp_dbg(sdata, "no gate was reachable\n");
1319 } else
1320 mesh_path_flush_pending(mpath);
1321 }
1322 }
1323
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1324 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1325 {
1326 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1327 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1328 u8 flags, target_flags = 0;
1329
1330 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1331 ? RANN_FLAG_IS_GATE : 0;
1332
1333 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1334 case IEEE80211_PROACTIVE_RANN:
1335 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1336 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1337 0, ifmsh->mshcfg.element_ttl,
1338 interval, 0, 0, sdata);
1339 break;
1340 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1341 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1342 fallthrough;
1343 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1344 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1345 target_flags |= IEEE80211_PREQ_TO_FLAG |
1346 IEEE80211_PREQ_USN_FLAG;
1347 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1348 ++ifmsh->sn, target_flags,
1349 (u8 *) broadcast_addr, 0, broadcast_addr,
1350 0, ifmsh->mshcfg.element_ttl, interval,
1351 0, ifmsh->preq_id++, sdata);
1352 break;
1353 default:
1354 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1355 return;
1356 }
1357 }
1358