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 * @sdata: local mesh subif
224 * @ttl: allowed remaining hops
225 * @target: broken destination
226 * @target_sn: SN of the broken destination
227 * @target_rcode: reason code for this PERR
228 * @ra: node this frame is addressed to
229 *
230 * Note: This function may be called with driver locks taken that the driver
231 * also acquires in the TX path. To avoid a deadlock we don't transmit the
232 * frame directly but add it to the pending queue instead.
233 *
234 * Returns: 0 on success
235 */
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 /* Check that the first metric is at least 10% better than the second one */
is_metric_better(u32 x,u32 y)371 static bool is_metric_better(u32 x, u32 y)
372 {
373 return (x < y) && (x < (y - x / 10));
374 }
375
376 /**
377 * hwmp_route_info_get - Update routing info to originator and transmitter
378 *
379 * @sdata: local mesh subif
380 * @mgmt: mesh management frame
381 * @hwmp_ie: hwmp information element (PREP or PREQ)
382 * @action: type of hwmp ie
383 *
384 * This function updates the path routing information to the originator and the
385 * transmitter of a HWMP PREQ or PREP frame.
386 *
387 * Returns: metric to frame originator or 0 if the frame should not be further
388 * processed
389 *
390 * Notes: this function is the only place (besides user-provided info) where
391 * path routing information is updated.
392 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)393 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
394 struct ieee80211_mgmt *mgmt,
395 const u8 *hwmp_ie, enum mpath_frame_type action)
396 {
397 struct ieee80211_local *local = sdata->local;
398 struct mesh_path *mpath;
399 struct sta_info *sta;
400 bool fresh_info;
401 const u8 *orig_addr, *ta;
402 u32 orig_sn, orig_metric;
403 unsigned long orig_lifetime, exp_time;
404 u32 last_hop_metric, new_metric;
405 bool flush_mpath = false;
406 bool process = true;
407 u8 hopcount;
408
409 rcu_read_lock();
410 sta = sta_info_get(sdata, mgmt->sa);
411 if (!sta) {
412 rcu_read_unlock();
413 return 0;
414 }
415
416 last_hop_metric = airtime_link_metric_get(local, sta);
417 /* Update and check originator routing info */
418 fresh_info = true;
419
420 switch (action) {
421 case MPATH_PREQ:
422 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
423 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
424 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
425 orig_metric = PREQ_IE_METRIC(hwmp_ie);
426 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
427 break;
428 case MPATH_PREP:
429 /* Originator here refers to the MP that was the target in the
430 * Path Request. We divert from the nomenclature in the draft
431 * so that we can easily use a single function to gather path
432 * information from both PREQ and PREP frames.
433 */
434 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
435 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
436 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
437 orig_metric = PREP_IE_METRIC(hwmp_ie);
438 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
439 break;
440 default:
441 rcu_read_unlock();
442 return 0;
443 }
444 new_metric = orig_metric + last_hop_metric;
445 if (new_metric < orig_metric)
446 new_metric = MAX_METRIC;
447 exp_time = TU_TO_EXP_TIME(orig_lifetime);
448
449 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
450 /* This MP is the originator, we are not interested in this
451 * frame, except for updating transmitter's path info.
452 */
453 process = false;
454 fresh_info = false;
455 } else {
456 mpath = mesh_path_lookup(sdata, orig_addr);
457 if (mpath) {
458 spin_lock_bh(&mpath->state_lock);
459 if (mpath->flags & MESH_PATH_FIXED)
460 fresh_info = false;
461 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
462 (mpath->flags & MESH_PATH_SN_VALID)) {
463 if (SN_GT(mpath->sn, orig_sn) ||
464 (mpath->sn == orig_sn &&
465 (rcu_access_pointer(mpath->next_hop) !=
466 sta ?
467 !is_metric_better(new_metric, mpath->metric) :
468 new_metric >= mpath->metric))) {
469 process = false;
470 fresh_info = false;
471 }
472 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
473 bool have_sn, newer_sn, bounced;
474
475 have_sn = mpath->flags & MESH_PATH_SN_VALID;
476 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
477 bounced = have_sn &&
478 (SN_DELTA(orig_sn, mpath->sn) >
479 MAX_SANE_SN_DELTA);
480
481 if (!have_sn || newer_sn) {
482 /* if SN is newer than what we had
483 * then we can take it */;
484 } else if (bounced) {
485 /* if SN is way different than what
486 * we had then assume the other side
487 * rebooted or restarted */;
488 } else {
489 process = false;
490 fresh_info = false;
491 }
492 }
493 } else {
494 mpath = mesh_path_add(sdata, orig_addr);
495 if (IS_ERR(mpath)) {
496 rcu_read_unlock();
497 return 0;
498 }
499 spin_lock_bh(&mpath->state_lock);
500 }
501
502 if (fresh_info) {
503 if (rcu_access_pointer(mpath->next_hop) != sta) {
504 mpath->path_change_count++;
505 flush_mpath = true;
506 }
507 mesh_path_assign_nexthop(mpath, sta);
508 mpath->flags |= MESH_PATH_SN_VALID;
509 mpath->metric = new_metric;
510 mpath->sn = orig_sn;
511 mpath->exp_time = time_after(mpath->exp_time, exp_time)
512 ? mpath->exp_time : exp_time;
513 mpath->hop_count = hopcount;
514 mesh_path_activate(mpath);
515 spin_unlock_bh(&mpath->state_lock);
516 if (flush_mpath)
517 mesh_fast_tx_flush_mpath(mpath);
518 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
519 /* init it at a low value - 0 start is tricky */
520 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
521 mesh_path_tx_pending(mpath);
522 /* draft says preq_id should be saved to, but there does
523 * not seem to be any use for it, skipping by now
524 */
525 } else
526 spin_unlock_bh(&mpath->state_lock);
527 }
528
529 /* Update and check transmitter routing info */
530 ta = mgmt->sa;
531 if (ether_addr_equal(orig_addr, ta))
532 fresh_info = false;
533 else {
534 fresh_info = true;
535
536 mpath = mesh_path_lookup(sdata, ta);
537 if (mpath) {
538 spin_lock_bh(&mpath->state_lock);
539 if ((mpath->flags & MESH_PATH_FIXED) ||
540 ((mpath->flags & MESH_PATH_ACTIVE) &&
541 ((rcu_access_pointer(mpath->next_hop) != sta ?
542 !is_metric_better(last_hop_metric, mpath->metric) :
543 last_hop_metric > mpath->metric))))
544 fresh_info = false;
545 } else {
546 mpath = mesh_path_add(sdata, ta);
547 if (IS_ERR(mpath)) {
548 rcu_read_unlock();
549 return 0;
550 }
551 spin_lock_bh(&mpath->state_lock);
552 }
553
554 if (fresh_info) {
555 if (rcu_access_pointer(mpath->next_hop) != sta) {
556 mpath->path_change_count++;
557 flush_mpath = true;
558 }
559 mesh_path_assign_nexthop(mpath, sta);
560 mpath->metric = last_hop_metric;
561 mpath->exp_time = time_after(mpath->exp_time, exp_time)
562 ? mpath->exp_time : exp_time;
563 mpath->hop_count = 1;
564 mesh_path_activate(mpath);
565 spin_unlock_bh(&mpath->state_lock);
566 if (flush_mpath)
567 mesh_fast_tx_flush_mpath(mpath);
568 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
569 /* init it at a low value - 0 start is tricky */
570 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
571 mesh_path_tx_pending(mpath);
572 } else
573 spin_unlock_bh(&mpath->state_lock);
574 }
575
576 rcu_read_unlock();
577
578 return process ? new_metric : 0;
579 }
580
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)581 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
582 struct ieee80211_mgmt *mgmt,
583 const u8 *preq_elem, u32 orig_metric)
584 {
585 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
586 struct mesh_path *mpath = NULL;
587 const u8 *target_addr, *orig_addr;
588 const u8 *da;
589 u8 target_flags, ttl, flags;
590 u32 orig_sn, target_sn, lifetime, target_metric = 0;
591 bool reply = false;
592 bool forward = true;
593 bool root_is_gate;
594
595 /* Update target SN, if present */
596 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
597 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
598 target_sn = PREQ_IE_TARGET_SN(preq_elem);
599 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
600 target_flags = PREQ_IE_TARGET_F(preq_elem);
601 /* Proactive PREQ gate announcements */
602 flags = PREQ_IE_FLAGS(preq_elem);
603 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
604
605 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
606
607 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
608 mhwmp_dbg(sdata, "PREQ is for us\n");
609 forward = false;
610 reply = true;
611 target_metric = 0;
612
613 if (SN_GT(target_sn, ifmsh->sn))
614 ifmsh->sn = target_sn;
615
616 if (time_after(jiffies, ifmsh->last_sn_update +
617 net_traversal_jiffies(sdata)) ||
618 time_before(jiffies, ifmsh->last_sn_update)) {
619 ++ifmsh->sn;
620 ifmsh->last_sn_update = jiffies;
621 }
622 target_sn = ifmsh->sn;
623 } else if (is_broadcast_ether_addr(target_addr) &&
624 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
625 rcu_read_lock();
626 mpath = mesh_path_lookup(sdata, orig_addr);
627 if (mpath) {
628 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
629 reply = true;
630 target_addr = sdata->vif.addr;
631 target_sn = ++ifmsh->sn;
632 target_metric = 0;
633 ifmsh->last_sn_update = jiffies;
634 }
635 if (root_is_gate)
636 mesh_path_add_gate(mpath);
637 }
638 rcu_read_unlock();
639 } else {
640 rcu_read_lock();
641 mpath = mesh_path_lookup(sdata, target_addr);
642 if (mpath) {
643 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
644 SN_LT(mpath->sn, target_sn)) {
645 mpath->sn = target_sn;
646 mpath->flags |= MESH_PATH_SN_VALID;
647 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
648 (mpath->flags & MESH_PATH_ACTIVE)) {
649 reply = true;
650 target_metric = mpath->metric;
651 target_sn = mpath->sn;
652 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
653 target_flags |= IEEE80211_PREQ_TO_FLAG;
654 }
655 }
656 rcu_read_unlock();
657 }
658
659 if (reply) {
660 lifetime = PREQ_IE_LIFETIME(preq_elem);
661 ttl = ifmsh->mshcfg.element_ttl;
662 if (ttl != 0) {
663 mhwmp_dbg(sdata, "replying to the PREQ\n");
664 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
665 orig_sn, 0, target_addr,
666 target_sn, mgmt->sa, 0, ttl,
667 lifetime, target_metric, 0,
668 sdata);
669 } else {
670 ifmsh->mshstats.dropped_frames_ttl++;
671 }
672 }
673
674 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
675 u32 preq_id;
676 u8 hopcount;
677
678 ttl = PREQ_IE_TTL(preq_elem);
679 lifetime = PREQ_IE_LIFETIME(preq_elem);
680 if (ttl <= 1) {
681 ifmsh->mshstats.dropped_frames_ttl++;
682 return;
683 }
684 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
685 --ttl;
686 preq_id = PREQ_IE_PREQ_ID(preq_elem);
687 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
688 da = (mpath && mpath->is_root) ?
689 mpath->rann_snd_addr : broadcast_addr;
690
691 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
692 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
693 target_sn = PREQ_IE_TARGET_SN(preq_elem);
694 }
695
696 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
697 orig_sn, target_flags, target_addr,
698 target_sn, da, hopcount, ttl, lifetime,
699 orig_metric, preq_id, sdata);
700 if (!is_multicast_ether_addr(da))
701 ifmsh->mshstats.fwded_unicast++;
702 else
703 ifmsh->mshstats.fwded_mcast++;
704 ifmsh->mshstats.fwded_frames++;
705 }
706 }
707
708
709 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)710 next_hop_deref_protected(struct mesh_path *mpath)
711 {
712 return rcu_dereference_protected(mpath->next_hop,
713 lockdep_is_held(&mpath->state_lock));
714 }
715
716
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)717 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
718 struct ieee80211_mgmt *mgmt,
719 const u8 *prep_elem, u32 metric)
720 {
721 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
722 struct mesh_path *mpath;
723 const u8 *target_addr, *orig_addr;
724 u8 ttl, hopcount, flags;
725 u8 next_hop[ETH_ALEN];
726 u32 target_sn, orig_sn, lifetime;
727
728 mhwmp_dbg(sdata, "received PREP from %pM\n",
729 PREP_IE_TARGET_ADDR(prep_elem));
730
731 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
732 if (ether_addr_equal(orig_addr, sdata->vif.addr))
733 /* destination, no forwarding required */
734 return;
735
736 if (!ifmsh->mshcfg.dot11MeshForwarding)
737 return;
738
739 ttl = PREP_IE_TTL(prep_elem);
740 if (ttl <= 1) {
741 sdata->u.mesh.mshstats.dropped_frames_ttl++;
742 return;
743 }
744
745 rcu_read_lock();
746 mpath = mesh_path_lookup(sdata, orig_addr);
747 if (mpath)
748 spin_lock_bh(&mpath->state_lock);
749 else
750 goto fail;
751 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
752 spin_unlock_bh(&mpath->state_lock);
753 goto fail;
754 }
755 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
756 spin_unlock_bh(&mpath->state_lock);
757 --ttl;
758 flags = PREP_IE_FLAGS(prep_elem);
759 lifetime = PREP_IE_LIFETIME(prep_elem);
760 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
761 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
762 target_sn = PREP_IE_TARGET_SN(prep_elem);
763 orig_sn = PREP_IE_ORIG_SN(prep_elem);
764
765 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
766 target_addr, target_sn, next_hop, hopcount,
767 ttl, lifetime, metric, 0, sdata);
768 rcu_read_unlock();
769
770 sdata->u.mesh.mshstats.fwded_unicast++;
771 sdata->u.mesh.mshstats.fwded_frames++;
772 return;
773
774 fail:
775 rcu_read_unlock();
776 sdata->u.mesh.mshstats.dropped_frames_no_route++;
777 }
778
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)779 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
780 struct ieee80211_mgmt *mgmt,
781 const u8 *perr_elem)
782 {
783 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
784 struct mesh_path *mpath;
785 u8 ttl;
786 const u8 *ta, *target_addr;
787 u32 target_sn;
788 u16 target_rcode;
789
790 ta = mgmt->sa;
791 ttl = PERR_IE_TTL(perr_elem);
792 if (ttl <= 1) {
793 ifmsh->mshstats.dropped_frames_ttl++;
794 return;
795 }
796 ttl--;
797 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
798 target_sn = PERR_IE_TARGET_SN(perr_elem);
799 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
800
801 rcu_read_lock();
802 mpath = mesh_path_lookup(sdata, target_addr);
803 if (mpath) {
804 struct sta_info *sta;
805
806 spin_lock_bh(&mpath->state_lock);
807 sta = next_hop_deref_protected(mpath);
808 if (mpath->flags & MESH_PATH_ACTIVE &&
809 ether_addr_equal(ta, sta->sta.addr) &&
810 !(mpath->flags & MESH_PATH_FIXED) &&
811 (!(mpath->flags & MESH_PATH_SN_VALID) ||
812 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
813 mpath->flags &= ~MESH_PATH_ACTIVE;
814 if (target_sn != 0)
815 mpath->sn = target_sn;
816 else
817 mpath->sn += 1;
818 spin_unlock_bh(&mpath->state_lock);
819 if (!ifmsh->mshcfg.dot11MeshForwarding)
820 goto endperr;
821 mesh_path_error_tx(sdata, ttl, target_addr,
822 target_sn, target_rcode,
823 broadcast_addr);
824 } else
825 spin_unlock_bh(&mpath->state_lock);
826 }
827 endperr:
828 rcu_read_unlock();
829 }
830
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)831 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
832 struct ieee80211_mgmt *mgmt,
833 const struct ieee80211_rann_ie *rann)
834 {
835 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
836 struct ieee80211_local *local = sdata->local;
837 struct sta_info *sta;
838 struct mesh_path *mpath;
839 u8 ttl, flags, hopcount;
840 const u8 *orig_addr;
841 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
842 bool root_is_gate;
843
844 ttl = rann->rann_ttl;
845 flags = rann->rann_flags;
846 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
847 orig_addr = rann->rann_addr;
848 orig_sn = le32_to_cpu(rann->rann_seq);
849 interval = le32_to_cpu(rann->rann_interval);
850 hopcount = rann->rann_hopcount;
851 hopcount++;
852 orig_metric = le32_to_cpu(rann->rann_metric);
853
854 /* Ignore our own RANNs */
855 if (ether_addr_equal(orig_addr, sdata->vif.addr))
856 return;
857
858 mhwmp_dbg(sdata,
859 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
860 orig_addr, mgmt->sa, root_is_gate);
861
862 rcu_read_lock();
863 sta = sta_info_get(sdata, mgmt->sa);
864 if (!sta) {
865 rcu_read_unlock();
866 return;
867 }
868
869 last_hop_metric = airtime_link_metric_get(local, sta);
870 new_metric = orig_metric + last_hop_metric;
871 if (new_metric < orig_metric)
872 new_metric = MAX_METRIC;
873
874 mpath = mesh_path_lookup(sdata, orig_addr);
875 if (!mpath) {
876 mpath = mesh_path_add(sdata, orig_addr);
877 if (IS_ERR(mpath)) {
878 rcu_read_unlock();
879 sdata->u.mesh.mshstats.dropped_frames_no_route++;
880 return;
881 }
882 }
883
884 if (!(SN_LT(mpath->sn, orig_sn)) &&
885 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
886 rcu_read_unlock();
887 return;
888 }
889
890 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
891 (time_after(jiffies, mpath->last_preq_to_root +
892 root_path_confirmation_jiffies(sdata)) ||
893 time_before(jiffies, mpath->last_preq_to_root))) &&
894 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
895 mhwmp_dbg(sdata,
896 "time to refresh root mpath %pM\n",
897 orig_addr);
898 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
899 mpath->last_preq_to_root = jiffies;
900 }
901
902 mpath->sn = orig_sn;
903 mpath->rann_metric = new_metric;
904 mpath->is_root = true;
905 /* Recording RANNs sender address to send individually
906 * addressed PREQs destined for root mesh STA */
907 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
908
909 if (root_is_gate)
910 mesh_path_add_gate(mpath);
911
912 if (ttl <= 1) {
913 ifmsh->mshstats.dropped_frames_ttl++;
914 rcu_read_unlock();
915 return;
916 }
917 ttl--;
918
919 if (ifmsh->mshcfg.dot11MeshForwarding) {
920 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
921 orig_sn, 0, NULL, 0, broadcast_addr,
922 hopcount, ttl, interval,
923 new_metric, 0, sdata);
924 }
925
926 rcu_read_unlock();
927 }
928
929
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)930 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
931 struct ieee80211_mgmt *mgmt, size_t len)
932 {
933 struct ieee802_11_elems *elems;
934 size_t baselen;
935 u32 path_metric;
936 struct sta_info *sta;
937
938 /* need action_code */
939 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
940 return;
941
942 rcu_read_lock();
943 sta = sta_info_get(sdata, mgmt->sa);
944 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
945 rcu_read_unlock();
946 return;
947 }
948 rcu_read_unlock();
949
950 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
951 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
952 len - baselen, false, NULL);
953 if (!elems)
954 return;
955
956 if (elems->preq) {
957 if (elems->preq_len != 37)
958 /* Right now we support just 1 destination and no AE */
959 goto free;
960 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
961 MPATH_PREQ);
962 if (path_metric)
963 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
964 path_metric);
965 }
966 if (elems->prep) {
967 if (elems->prep_len != 31)
968 /* Right now we support no AE */
969 goto free;
970 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
971 MPATH_PREP);
972 if (path_metric)
973 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
974 path_metric);
975 }
976 if (elems->perr) {
977 if (elems->perr_len != 15)
978 /* Right now we support only one destination per PERR */
979 goto free;
980 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
981 }
982 if (elems->rann)
983 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
984 free:
985 kfree(elems);
986 }
987
988 /**
989 * mesh_queue_preq - queue a PREQ to a given destination
990 *
991 * @mpath: mesh path to discover
992 * @flags: special attributes of the PREQ to be sent
993 *
994 * Locking: the function must be called from within a rcu read lock block.
995 *
996 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)997 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
998 {
999 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1000 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1001 struct mesh_preq_queue *preq_node;
1002
1003 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
1004 if (!preq_node) {
1005 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
1006 return;
1007 }
1008
1009 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1010 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
1011 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1012 kfree(preq_node);
1013 if (printk_ratelimit())
1014 mhwmp_dbg(sdata, "PREQ node queue full\n");
1015 return;
1016 }
1017
1018 spin_lock(&mpath->state_lock);
1019 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1020 spin_unlock(&mpath->state_lock);
1021 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1022 kfree(preq_node);
1023 return;
1024 }
1025
1026 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1027 preq_node->flags = flags;
1028
1029 mpath->flags |= MESH_PATH_REQ_QUEUED;
1030 spin_unlock(&mpath->state_lock);
1031
1032 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1033 ++ifmsh->preq_queue_len;
1034 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1035
1036 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1037 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1038
1039 else if (time_before(jiffies, ifmsh->last_preq)) {
1040 /* avoid long wait if did not send preqs for a long time
1041 * and jiffies wrapped around
1042 */
1043 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1044 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1045 } else
1046 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1047 min_preq_int_jiff(sdata));
1048 }
1049
1050 /**
1051 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1052 *
1053 * @sdata: local mesh subif
1054 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1055 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1056 {
1057 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1058 struct mesh_preq_queue *preq_node;
1059 struct mesh_path *mpath;
1060 u8 ttl, target_flags = 0;
1061 const u8 *da;
1062 u32 lifetime;
1063
1064 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1065 if (!ifmsh->preq_queue_len ||
1066 time_before(jiffies, ifmsh->last_preq +
1067 min_preq_int_jiff(sdata))) {
1068 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1069 return;
1070 }
1071
1072 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1073 struct mesh_preq_queue, list);
1074 list_del(&preq_node->list);
1075 --ifmsh->preq_queue_len;
1076 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1077
1078 rcu_read_lock();
1079 mpath = mesh_path_lookup(sdata, preq_node->dst);
1080 if (!mpath)
1081 goto enddiscovery;
1082
1083 spin_lock_bh(&mpath->state_lock);
1084 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1085 spin_unlock_bh(&mpath->state_lock);
1086 goto enddiscovery;
1087 }
1088 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1089 if (preq_node->flags & PREQ_Q_F_START) {
1090 if (mpath->flags & MESH_PATH_RESOLVING) {
1091 spin_unlock_bh(&mpath->state_lock);
1092 goto enddiscovery;
1093 } else {
1094 mpath->flags &= ~MESH_PATH_RESOLVED;
1095 mpath->flags |= MESH_PATH_RESOLVING;
1096 mpath->discovery_retries = 0;
1097 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1098 }
1099 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1100 mpath->flags & MESH_PATH_RESOLVED) {
1101 mpath->flags &= ~MESH_PATH_RESOLVING;
1102 spin_unlock_bh(&mpath->state_lock);
1103 goto enddiscovery;
1104 }
1105
1106 ifmsh->last_preq = jiffies;
1107
1108 if (time_after(jiffies, ifmsh->last_sn_update +
1109 net_traversal_jiffies(sdata)) ||
1110 time_before(jiffies, ifmsh->last_sn_update)) {
1111 ++ifmsh->sn;
1112 sdata->u.mesh.last_sn_update = jiffies;
1113 }
1114 lifetime = default_lifetime(sdata);
1115 ttl = sdata->u.mesh.mshcfg.element_ttl;
1116 if (ttl == 0) {
1117 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1118 spin_unlock_bh(&mpath->state_lock);
1119 goto enddiscovery;
1120 }
1121
1122 if (preq_node->flags & PREQ_Q_F_REFRESH)
1123 target_flags |= IEEE80211_PREQ_TO_FLAG;
1124 else
1125 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1126
1127 spin_unlock_bh(&mpath->state_lock);
1128 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1129 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1130 target_flags, mpath->dst, mpath->sn, da, 0,
1131 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1132
1133 spin_lock_bh(&mpath->state_lock);
1134 if (!(mpath->flags & MESH_PATH_DELETED))
1135 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1136 spin_unlock_bh(&mpath->state_lock);
1137
1138 enddiscovery:
1139 rcu_read_unlock();
1140 kfree(preq_node);
1141 }
1142
1143 /**
1144 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1145 *
1146 * @sdata: network subif the frame will be sent through
1147 * @skb: 802.11 frame to be sent
1148 *
1149 * Lookup next hop for given skb and start path discovery if no
1150 * forwarding information is found.
1151 *
1152 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1153 * skb is freed here if no mpath could be allocated.
1154 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1155 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1156 struct sk_buff *skb)
1157 {
1158 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1159 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1160 struct mesh_path *mpath;
1161 struct sk_buff *skb_to_free = NULL;
1162 u8 *target_addr = hdr->addr3;
1163
1164 /* Nulls are only sent to peers for PS and should be pre-addressed */
1165 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1166 return 0;
1167
1168 /* Allow injected packets to bypass mesh routing */
1169 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1170 return 0;
1171
1172 if (!mesh_nexthop_lookup(sdata, skb))
1173 return 0;
1174
1175 /* no nexthop found, start resolving */
1176 mpath = mesh_path_lookup(sdata, target_addr);
1177 if (!mpath) {
1178 mpath = mesh_path_add(sdata, target_addr);
1179 if (IS_ERR(mpath)) {
1180 mesh_path_discard_frame(sdata, skb);
1181 return PTR_ERR(mpath);
1182 }
1183 }
1184
1185 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1186 mesh_path_sel_is_hwmp(sdata))
1187 mesh_queue_preq(mpath, PREQ_Q_F_START);
1188
1189 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1190 skb_to_free = skb_dequeue(&mpath->frame_queue);
1191
1192 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1193 ieee80211_set_qos_hdr(sdata, skb);
1194 skb_queue_tail(&mpath->frame_queue, skb);
1195 if (skb_to_free)
1196 mesh_path_discard_frame(sdata, skb_to_free);
1197
1198 return -ENOENT;
1199 }
1200
1201 /**
1202 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1203 * @skb: 802.11 frame to be sent
1204 * @sdata: network subif the frame will be sent through
1205 *
1206 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1207 * And if so, set the RA (addr1) to it to transmit to this node directly,
1208 * avoiding PREQ/PREP path discovery.
1209 *
1210 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1211 */
mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1212 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1213 struct sk_buff *skb)
1214 {
1215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1216 struct sta_info *sta;
1217
1218 if (is_multicast_ether_addr(hdr->addr1))
1219 return -ENOENT;
1220
1221 rcu_read_lock();
1222 sta = sta_info_get(sdata, hdr->addr3);
1223
1224 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1225 rcu_read_unlock();
1226 return -ENOENT;
1227 }
1228 rcu_read_unlock();
1229
1230 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1231 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1232 return 0;
1233 }
1234
mesh_path_refresh(struct ieee80211_sub_if_data * sdata,struct mesh_path * mpath,const u8 * addr)1235 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata,
1236 struct mesh_path *mpath, const u8 *addr)
1237 {
1238 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED |
1239 MESH_PATH_RESOLVING))
1240 return;
1241
1242 if (time_after(jiffies,
1243 mpath->exp_time -
1244 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1245 (!addr || ether_addr_equal(sdata->vif.addr, addr)))
1246 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1247 }
1248
1249 /**
1250 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1251 * this function is considered "using" the associated mpath, so preempt a path
1252 * refresh if this mpath expires soon.
1253 *
1254 * @sdata: network subif the frame will be sent through
1255 * @skb: 802.11 frame to be sent
1256 *
1257 * Returns: 0 if the next hop was found. Nonzero otherwise.
1258 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1259 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1260 struct sk_buff *skb)
1261 {
1262 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1263 struct mesh_path *mpath;
1264 struct sta_info *next_hop;
1265 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1266 u8 *target_addr = hdr->addr3;
1267
1268 if (ifmsh->mshcfg.dot11MeshNolearn &&
1269 !mesh_nexthop_lookup_nolearn(sdata, skb))
1270 return 0;
1271
1272 mpath = mesh_path_lookup(sdata, target_addr);
1273 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1274 return -ENOENT;
1275
1276 mesh_path_refresh(sdata, mpath, hdr->addr4);
1277
1278 next_hop = rcu_dereference(mpath->next_hop);
1279 if (next_hop) {
1280 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1281 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1282 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1283 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT))
1284 mesh_fast_tx_cache(sdata, skb, mpath);
1285 return 0;
1286 }
1287
1288 return -ENOENT;
1289 }
1290
mesh_path_timer(struct timer_list * t)1291 void mesh_path_timer(struct timer_list *t)
1292 {
1293 struct mesh_path *mpath = from_timer(mpath, t, timer);
1294 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1295 int ret;
1296
1297 if (sdata->local->quiescing)
1298 return;
1299
1300 spin_lock_bh(&mpath->state_lock);
1301 if (mpath->flags & MESH_PATH_RESOLVED ||
1302 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1303 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1304 spin_unlock_bh(&mpath->state_lock);
1305 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1306 ++mpath->discovery_retries;
1307 mpath->discovery_timeout *= 2;
1308 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1309 spin_unlock_bh(&mpath->state_lock);
1310 mesh_queue_preq(mpath, 0);
1311 } else {
1312 mpath->flags &= ~(MESH_PATH_RESOLVING |
1313 MESH_PATH_RESOLVED |
1314 MESH_PATH_REQ_QUEUED);
1315 mpath->exp_time = jiffies;
1316 spin_unlock_bh(&mpath->state_lock);
1317 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1318 ret = mesh_path_send_to_gates(mpath);
1319 if (ret)
1320 mhwmp_dbg(sdata, "no gate was reachable\n");
1321 } else
1322 mesh_path_flush_pending(mpath);
1323 }
1324 }
1325
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1326 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1327 {
1328 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1329 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1330 u8 flags, target_flags = 0;
1331
1332 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1333 ? RANN_FLAG_IS_GATE : 0;
1334
1335 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1336 case IEEE80211_PROACTIVE_RANN:
1337 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1338 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1339 0, ifmsh->mshcfg.element_ttl,
1340 interval, 0, 0, sdata);
1341 break;
1342 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1343 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1344 fallthrough;
1345 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1346 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1347 target_flags |= IEEE80211_PREQ_TO_FLAG |
1348 IEEE80211_PREQ_USN_FLAG;
1349 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1350 ++ifmsh->sn, target_flags,
1351 (u8 *) broadcast_addr, 0, broadcast_addr,
1352 0, ifmsh->mshcfg.element_ttl, interval,
1353 0, ifmsh->preq_id++, sdata);
1354 break;
1355 default:
1356 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1357 return;
1358 }
1359 }
1360