1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Copyright (C) 2019, 2021-2022 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 process = true;
398 u8 hopcount;
399
400 rcu_read_lock();
401 sta = sta_info_get(sdata, mgmt->sa);
402 if (!sta) {
403 rcu_read_unlock();
404 return 0;
405 }
406
407 last_hop_metric = airtime_link_metric_get(local, sta);
408 /* Update and check originator routing info */
409 fresh_info = true;
410
411 switch (action) {
412 case MPATH_PREQ:
413 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
414 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
415 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
416 orig_metric = PREQ_IE_METRIC(hwmp_ie);
417 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
418 break;
419 case MPATH_PREP:
420 /* Originator here refers to the MP that was the target in the
421 * Path Request. We divert from the nomenclature in the draft
422 * so that we can easily use a single function to gather path
423 * information from both PREQ and PREP frames.
424 */
425 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
426 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
427 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
428 orig_metric = PREP_IE_METRIC(hwmp_ie);
429 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
430 break;
431 default:
432 rcu_read_unlock();
433 return 0;
434 }
435 new_metric = orig_metric + last_hop_metric;
436 if (new_metric < orig_metric)
437 new_metric = MAX_METRIC;
438 exp_time = TU_TO_EXP_TIME(orig_lifetime);
439
440 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
441 /* This MP is the originator, we are not interested in this
442 * frame, except for updating transmitter's path info.
443 */
444 process = false;
445 fresh_info = false;
446 } else {
447 mpath = mesh_path_lookup(sdata, orig_addr);
448 if (mpath) {
449 spin_lock_bh(&mpath->state_lock);
450 if (mpath->flags & MESH_PATH_FIXED)
451 fresh_info = false;
452 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
453 (mpath->flags & MESH_PATH_SN_VALID)) {
454 if (SN_GT(mpath->sn, orig_sn) ||
455 (mpath->sn == orig_sn &&
456 (rcu_access_pointer(mpath->next_hop) !=
457 sta ?
458 mult_frac(new_metric, 10, 9) :
459 new_metric) >= mpath->metric)) {
460 process = false;
461 fresh_info = false;
462 }
463 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
464 bool have_sn, newer_sn, bounced;
465
466 have_sn = mpath->flags & MESH_PATH_SN_VALID;
467 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
468 bounced = have_sn &&
469 (SN_DELTA(orig_sn, mpath->sn) >
470 MAX_SANE_SN_DELTA);
471
472 if (!have_sn || newer_sn) {
473 /* if SN is newer than what we had
474 * then we can take it */;
475 } else if (bounced) {
476 /* if SN is way different than what
477 * we had then assume the other side
478 * rebooted or restarted */;
479 } else {
480 process = false;
481 fresh_info = false;
482 }
483 }
484 } else {
485 mpath = mesh_path_add(sdata, orig_addr);
486 if (IS_ERR(mpath)) {
487 rcu_read_unlock();
488 return 0;
489 }
490 spin_lock_bh(&mpath->state_lock);
491 }
492
493 if (fresh_info) {
494 if (rcu_access_pointer(mpath->next_hop) != sta)
495 mpath->path_change_count++;
496 mesh_path_assign_nexthop(mpath, sta);
497 mpath->flags |= MESH_PATH_SN_VALID;
498 mpath->metric = new_metric;
499 mpath->sn = orig_sn;
500 mpath->exp_time = time_after(mpath->exp_time, exp_time)
501 ? mpath->exp_time : exp_time;
502 mpath->hop_count = hopcount;
503 mesh_path_activate(mpath);
504 spin_unlock_bh(&mpath->state_lock);
505 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
506 /* init it at a low value - 0 start is tricky */
507 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
508 mesh_path_tx_pending(mpath);
509 /* draft says preq_id should be saved to, but there does
510 * not seem to be any use for it, skipping by now
511 */
512 } else
513 spin_unlock_bh(&mpath->state_lock);
514 }
515
516 /* Update and check transmitter routing info */
517 ta = mgmt->sa;
518 if (ether_addr_equal(orig_addr, ta))
519 fresh_info = false;
520 else {
521 fresh_info = true;
522
523 mpath = mesh_path_lookup(sdata, ta);
524 if (mpath) {
525 spin_lock_bh(&mpath->state_lock);
526 if ((mpath->flags & MESH_PATH_FIXED) ||
527 ((mpath->flags & MESH_PATH_ACTIVE) &&
528 ((rcu_access_pointer(mpath->next_hop) != sta ?
529 mult_frac(last_hop_metric, 10, 9) :
530 last_hop_metric) > mpath->metric)))
531 fresh_info = false;
532 } else {
533 mpath = mesh_path_add(sdata, ta);
534 if (IS_ERR(mpath)) {
535 rcu_read_unlock();
536 return 0;
537 }
538 spin_lock_bh(&mpath->state_lock);
539 }
540
541 if (fresh_info) {
542 if (rcu_access_pointer(mpath->next_hop) != sta)
543 mpath->path_change_count++;
544 mesh_path_assign_nexthop(mpath, sta);
545 mpath->metric = last_hop_metric;
546 mpath->exp_time = time_after(mpath->exp_time, exp_time)
547 ? mpath->exp_time : exp_time;
548 mpath->hop_count = 1;
549 mesh_path_activate(mpath);
550 spin_unlock_bh(&mpath->state_lock);
551 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
552 /* init it at a low value - 0 start is tricky */
553 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
554 mesh_path_tx_pending(mpath);
555 } else
556 spin_unlock_bh(&mpath->state_lock);
557 }
558
559 rcu_read_unlock();
560
561 return process ? new_metric : 0;
562 }
563
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)564 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
565 struct ieee80211_mgmt *mgmt,
566 const u8 *preq_elem, u32 orig_metric)
567 {
568 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
569 struct mesh_path *mpath = NULL;
570 const u8 *target_addr, *orig_addr;
571 const u8 *da;
572 u8 target_flags, ttl, flags;
573 u32 orig_sn, target_sn, lifetime, target_metric = 0;
574 bool reply = false;
575 bool forward = true;
576 bool root_is_gate;
577
578 /* Update target SN, if present */
579 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
580 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
581 target_sn = PREQ_IE_TARGET_SN(preq_elem);
582 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
583 target_flags = PREQ_IE_TARGET_F(preq_elem);
584 /* Proactive PREQ gate announcements */
585 flags = PREQ_IE_FLAGS(preq_elem);
586 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
587
588 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
589
590 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
591 mhwmp_dbg(sdata, "PREQ is for us\n");
592 forward = false;
593 reply = true;
594 target_metric = 0;
595
596 if (SN_GT(target_sn, ifmsh->sn))
597 ifmsh->sn = target_sn;
598
599 if (time_after(jiffies, ifmsh->last_sn_update +
600 net_traversal_jiffies(sdata)) ||
601 time_before(jiffies, ifmsh->last_sn_update)) {
602 ++ifmsh->sn;
603 ifmsh->last_sn_update = jiffies;
604 }
605 target_sn = ifmsh->sn;
606 } else if (is_broadcast_ether_addr(target_addr) &&
607 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
608 rcu_read_lock();
609 mpath = mesh_path_lookup(sdata, orig_addr);
610 if (mpath) {
611 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
612 reply = true;
613 target_addr = sdata->vif.addr;
614 target_sn = ++ifmsh->sn;
615 target_metric = 0;
616 ifmsh->last_sn_update = jiffies;
617 }
618 if (root_is_gate)
619 mesh_path_add_gate(mpath);
620 }
621 rcu_read_unlock();
622 } else {
623 rcu_read_lock();
624 mpath = mesh_path_lookup(sdata, target_addr);
625 if (mpath) {
626 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
627 SN_LT(mpath->sn, target_sn)) {
628 mpath->sn = target_sn;
629 mpath->flags |= MESH_PATH_SN_VALID;
630 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
631 (mpath->flags & MESH_PATH_ACTIVE)) {
632 reply = true;
633 target_metric = mpath->metric;
634 target_sn = mpath->sn;
635 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
636 target_flags |= IEEE80211_PREQ_TO_FLAG;
637 }
638 }
639 rcu_read_unlock();
640 }
641
642 if (reply) {
643 lifetime = PREQ_IE_LIFETIME(preq_elem);
644 ttl = ifmsh->mshcfg.element_ttl;
645 if (ttl != 0) {
646 mhwmp_dbg(sdata, "replying to the PREQ\n");
647 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
648 orig_sn, 0, target_addr,
649 target_sn, mgmt->sa, 0, ttl,
650 lifetime, target_metric, 0,
651 sdata);
652 } else {
653 ifmsh->mshstats.dropped_frames_ttl++;
654 }
655 }
656
657 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
658 u32 preq_id;
659 u8 hopcount;
660
661 ttl = PREQ_IE_TTL(preq_elem);
662 lifetime = PREQ_IE_LIFETIME(preq_elem);
663 if (ttl <= 1) {
664 ifmsh->mshstats.dropped_frames_ttl++;
665 return;
666 }
667 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
668 --ttl;
669 preq_id = PREQ_IE_PREQ_ID(preq_elem);
670 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
671 da = (mpath && mpath->is_root) ?
672 mpath->rann_snd_addr : broadcast_addr;
673
674 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
675 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
676 target_sn = PREQ_IE_TARGET_SN(preq_elem);
677 }
678
679 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
680 orig_sn, target_flags, target_addr,
681 target_sn, da, hopcount, ttl, lifetime,
682 orig_metric, preq_id, sdata);
683 if (!is_multicast_ether_addr(da))
684 ifmsh->mshstats.fwded_unicast++;
685 else
686 ifmsh->mshstats.fwded_mcast++;
687 ifmsh->mshstats.fwded_frames++;
688 }
689 }
690
691
692 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)693 next_hop_deref_protected(struct mesh_path *mpath)
694 {
695 return rcu_dereference_protected(mpath->next_hop,
696 lockdep_is_held(&mpath->state_lock));
697 }
698
699
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)700 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
701 struct ieee80211_mgmt *mgmt,
702 const u8 *prep_elem, u32 metric)
703 {
704 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
705 struct mesh_path *mpath;
706 const u8 *target_addr, *orig_addr;
707 u8 ttl, hopcount, flags;
708 u8 next_hop[ETH_ALEN];
709 u32 target_sn, orig_sn, lifetime;
710
711 mhwmp_dbg(sdata, "received PREP from %pM\n",
712 PREP_IE_TARGET_ADDR(prep_elem));
713
714 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
715 if (ether_addr_equal(orig_addr, sdata->vif.addr))
716 /* destination, no forwarding required */
717 return;
718
719 if (!ifmsh->mshcfg.dot11MeshForwarding)
720 return;
721
722 ttl = PREP_IE_TTL(prep_elem);
723 if (ttl <= 1) {
724 sdata->u.mesh.mshstats.dropped_frames_ttl++;
725 return;
726 }
727
728 rcu_read_lock();
729 mpath = mesh_path_lookup(sdata, orig_addr);
730 if (mpath)
731 spin_lock_bh(&mpath->state_lock);
732 else
733 goto fail;
734 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
735 spin_unlock_bh(&mpath->state_lock);
736 goto fail;
737 }
738 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
739 spin_unlock_bh(&mpath->state_lock);
740 --ttl;
741 flags = PREP_IE_FLAGS(prep_elem);
742 lifetime = PREP_IE_LIFETIME(prep_elem);
743 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
744 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
745 target_sn = PREP_IE_TARGET_SN(prep_elem);
746 orig_sn = PREP_IE_ORIG_SN(prep_elem);
747
748 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
749 target_addr, target_sn, next_hop, hopcount,
750 ttl, lifetime, metric, 0, sdata);
751 rcu_read_unlock();
752
753 sdata->u.mesh.mshstats.fwded_unicast++;
754 sdata->u.mesh.mshstats.fwded_frames++;
755 return;
756
757 fail:
758 rcu_read_unlock();
759 sdata->u.mesh.mshstats.dropped_frames_no_route++;
760 }
761
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)762 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
763 struct ieee80211_mgmt *mgmt,
764 const u8 *perr_elem)
765 {
766 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
767 struct mesh_path *mpath;
768 u8 ttl;
769 const u8 *ta, *target_addr;
770 u32 target_sn;
771 u16 target_rcode;
772
773 ta = mgmt->sa;
774 ttl = PERR_IE_TTL(perr_elem);
775 if (ttl <= 1) {
776 ifmsh->mshstats.dropped_frames_ttl++;
777 return;
778 }
779 ttl--;
780 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
781 target_sn = PERR_IE_TARGET_SN(perr_elem);
782 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
783
784 rcu_read_lock();
785 mpath = mesh_path_lookup(sdata, target_addr);
786 if (mpath) {
787 struct sta_info *sta;
788
789 spin_lock_bh(&mpath->state_lock);
790 sta = next_hop_deref_protected(mpath);
791 if (mpath->flags & MESH_PATH_ACTIVE &&
792 ether_addr_equal(ta, sta->sta.addr) &&
793 !(mpath->flags & MESH_PATH_FIXED) &&
794 (!(mpath->flags & MESH_PATH_SN_VALID) ||
795 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
796 mpath->flags &= ~MESH_PATH_ACTIVE;
797 if (target_sn != 0)
798 mpath->sn = target_sn;
799 else
800 mpath->sn += 1;
801 spin_unlock_bh(&mpath->state_lock);
802 if (!ifmsh->mshcfg.dot11MeshForwarding)
803 goto endperr;
804 mesh_path_error_tx(sdata, ttl, target_addr,
805 target_sn, target_rcode,
806 broadcast_addr);
807 } else
808 spin_unlock_bh(&mpath->state_lock);
809 }
810 endperr:
811 rcu_read_unlock();
812 }
813
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)814 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
815 struct ieee80211_mgmt *mgmt,
816 const struct ieee80211_rann_ie *rann)
817 {
818 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
819 struct ieee80211_local *local = sdata->local;
820 struct sta_info *sta;
821 struct mesh_path *mpath;
822 u8 ttl, flags, hopcount;
823 const u8 *orig_addr;
824 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
825 bool root_is_gate;
826
827 ttl = rann->rann_ttl;
828 flags = rann->rann_flags;
829 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
830 orig_addr = rann->rann_addr;
831 orig_sn = le32_to_cpu(rann->rann_seq);
832 interval = le32_to_cpu(rann->rann_interval);
833 hopcount = rann->rann_hopcount;
834 hopcount++;
835 orig_metric = le32_to_cpu(rann->rann_metric);
836
837 /* Ignore our own RANNs */
838 if (ether_addr_equal(orig_addr, sdata->vif.addr))
839 return;
840
841 mhwmp_dbg(sdata,
842 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
843 orig_addr, mgmt->sa, root_is_gate);
844
845 rcu_read_lock();
846 sta = sta_info_get(sdata, mgmt->sa);
847 if (!sta) {
848 rcu_read_unlock();
849 return;
850 }
851
852 last_hop_metric = airtime_link_metric_get(local, sta);
853 new_metric = orig_metric + last_hop_metric;
854 if (new_metric < orig_metric)
855 new_metric = MAX_METRIC;
856
857 mpath = mesh_path_lookup(sdata, orig_addr);
858 if (!mpath) {
859 mpath = mesh_path_add(sdata, orig_addr);
860 if (IS_ERR(mpath)) {
861 rcu_read_unlock();
862 sdata->u.mesh.mshstats.dropped_frames_no_route++;
863 return;
864 }
865 }
866
867 if (!(SN_LT(mpath->sn, orig_sn)) &&
868 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
869 rcu_read_unlock();
870 return;
871 }
872
873 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
874 (time_after(jiffies, mpath->last_preq_to_root +
875 root_path_confirmation_jiffies(sdata)) ||
876 time_before(jiffies, mpath->last_preq_to_root))) &&
877 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
878 mhwmp_dbg(sdata,
879 "time to refresh root mpath %pM\n",
880 orig_addr);
881 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
882 mpath->last_preq_to_root = jiffies;
883 }
884
885 mpath->sn = orig_sn;
886 mpath->rann_metric = new_metric;
887 mpath->is_root = true;
888 /* Recording RANNs sender address to send individually
889 * addressed PREQs destined for root mesh STA */
890 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
891
892 if (root_is_gate)
893 mesh_path_add_gate(mpath);
894
895 if (ttl <= 1) {
896 ifmsh->mshstats.dropped_frames_ttl++;
897 rcu_read_unlock();
898 return;
899 }
900 ttl--;
901
902 if (ifmsh->mshcfg.dot11MeshForwarding) {
903 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
904 orig_sn, 0, NULL, 0, broadcast_addr,
905 hopcount, ttl, interval,
906 new_metric, 0, sdata);
907 }
908
909 rcu_read_unlock();
910 }
911
912
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)913 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
914 struct ieee80211_mgmt *mgmt, size_t len)
915 {
916 struct ieee802_11_elems *elems;
917 size_t baselen;
918 u32 path_metric;
919 struct sta_info *sta;
920
921 /* need action_code */
922 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
923 return;
924
925 rcu_read_lock();
926 sta = sta_info_get(sdata, mgmt->sa);
927 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
928 rcu_read_unlock();
929 return;
930 }
931 rcu_read_unlock();
932
933 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
934 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
935 len - baselen, false, NULL);
936 if (!elems)
937 return;
938
939 if (elems->preq) {
940 if (elems->preq_len != 37)
941 /* Right now we support just 1 destination and no AE */
942 goto free;
943 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq,
944 MPATH_PREQ);
945 if (path_metric)
946 hwmp_preq_frame_process(sdata, mgmt, elems->preq,
947 path_metric);
948 }
949 if (elems->prep) {
950 if (elems->prep_len != 31)
951 /* Right now we support no AE */
952 goto free;
953 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep,
954 MPATH_PREP);
955 if (path_metric)
956 hwmp_prep_frame_process(sdata, mgmt, elems->prep,
957 path_metric);
958 }
959 if (elems->perr) {
960 if (elems->perr_len != 15)
961 /* Right now we support only one destination per PERR */
962 goto free;
963 hwmp_perr_frame_process(sdata, mgmt, elems->perr);
964 }
965 if (elems->rann)
966 hwmp_rann_frame_process(sdata, mgmt, elems->rann);
967 free:
968 kfree(elems);
969 }
970
971 /**
972 * mesh_queue_preq - queue a PREQ to a given destination
973 *
974 * @mpath: mesh path to discover
975 * @flags: special attributes of the PREQ to be sent
976 *
977 * Locking: the function must be called from within a rcu read lock block.
978 *
979 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)980 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
981 {
982 struct ieee80211_sub_if_data *sdata = mpath->sdata;
983 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
984 struct mesh_preq_queue *preq_node;
985
986 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
987 if (!preq_node) {
988 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
989 return;
990 }
991
992 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
993 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
994 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
995 kfree(preq_node);
996 if (printk_ratelimit())
997 mhwmp_dbg(sdata, "PREQ node queue full\n");
998 return;
999 }
1000
1001 spin_lock(&mpath->state_lock);
1002 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
1003 spin_unlock(&mpath->state_lock);
1004 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1005 kfree(preq_node);
1006 return;
1007 }
1008
1009 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
1010 preq_node->flags = flags;
1011
1012 mpath->flags |= MESH_PATH_REQ_QUEUED;
1013 spin_unlock(&mpath->state_lock);
1014
1015 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
1016 ++ifmsh->preq_queue_len;
1017 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1018
1019 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
1020 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1021
1022 else if (time_before(jiffies, ifmsh->last_preq)) {
1023 /* avoid long wait if did not send preqs for a long time
1024 * and jiffies wrapped around
1025 */
1026 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1027 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1028 } else
1029 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1030 min_preq_int_jiff(sdata));
1031 }
1032
1033 /**
1034 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1035 *
1036 * @sdata: local mesh subif
1037 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1038 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1039 {
1040 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1041 struct mesh_preq_queue *preq_node;
1042 struct mesh_path *mpath;
1043 u8 ttl, target_flags = 0;
1044 const u8 *da;
1045 u32 lifetime;
1046
1047 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1048 if (!ifmsh->preq_queue_len ||
1049 time_before(jiffies, ifmsh->last_preq +
1050 min_preq_int_jiff(sdata))) {
1051 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1052 return;
1053 }
1054
1055 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1056 struct mesh_preq_queue, list);
1057 list_del(&preq_node->list);
1058 --ifmsh->preq_queue_len;
1059 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1060
1061 rcu_read_lock();
1062 mpath = mesh_path_lookup(sdata, preq_node->dst);
1063 if (!mpath)
1064 goto enddiscovery;
1065
1066 spin_lock_bh(&mpath->state_lock);
1067 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1068 spin_unlock_bh(&mpath->state_lock);
1069 goto enddiscovery;
1070 }
1071 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1072 if (preq_node->flags & PREQ_Q_F_START) {
1073 if (mpath->flags & MESH_PATH_RESOLVING) {
1074 spin_unlock_bh(&mpath->state_lock);
1075 goto enddiscovery;
1076 } else {
1077 mpath->flags &= ~MESH_PATH_RESOLVED;
1078 mpath->flags |= MESH_PATH_RESOLVING;
1079 mpath->discovery_retries = 0;
1080 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1081 }
1082 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1083 mpath->flags & MESH_PATH_RESOLVED) {
1084 mpath->flags &= ~MESH_PATH_RESOLVING;
1085 spin_unlock_bh(&mpath->state_lock);
1086 goto enddiscovery;
1087 }
1088
1089 ifmsh->last_preq = jiffies;
1090
1091 if (time_after(jiffies, ifmsh->last_sn_update +
1092 net_traversal_jiffies(sdata)) ||
1093 time_before(jiffies, ifmsh->last_sn_update)) {
1094 ++ifmsh->sn;
1095 sdata->u.mesh.last_sn_update = jiffies;
1096 }
1097 lifetime = default_lifetime(sdata);
1098 ttl = sdata->u.mesh.mshcfg.element_ttl;
1099 if (ttl == 0) {
1100 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1101 spin_unlock_bh(&mpath->state_lock);
1102 goto enddiscovery;
1103 }
1104
1105 if (preq_node->flags & PREQ_Q_F_REFRESH)
1106 target_flags |= IEEE80211_PREQ_TO_FLAG;
1107 else
1108 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1109
1110 spin_unlock_bh(&mpath->state_lock);
1111 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1112 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1113 target_flags, mpath->dst, mpath->sn, da, 0,
1114 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1115
1116 spin_lock_bh(&mpath->state_lock);
1117 if (!(mpath->flags & MESH_PATH_DELETED))
1118 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1119 spin_unlock_bh(&mpath->state_lock);
1120
1121 enddiscovery:
1122 rcu_read_unlock();
1123 kfree(preq_node);
1124 }
1125
1126 /**
1127 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1128 *
1129 * @skb: 802.11 frame to be sent
1130 * @sdata: network subif the frame will be sent through
1131 *
1132 * Lookup next hop for given skb and start path discovery if no
1133 * forwarding information is found.
1134 *
1135 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1136 * skb is freed here if no mpath could be allocated.
1137 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1138 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1139 struct sk_buff *skb)
1140 {
1141 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1142 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1143 struct mesh_path *mpath;
1144 struct sk_buff *skb_to_free = NULL;
1145 u8 *target_addr = hdr->addr3;
1146
1147 /* Nulls are only sent to peers for PS and should be pre-addressed */
1148 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1149 return 0;
1150
1151 /* Allow injected packets to bypass mesh routing */
1152 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
1153 return 0;
1154
1155 if (!mesh_nexthop_lookup(sdata, skb))
1156 return 0;
1157
1158 /* no nexthop found, start resolving */
1159 mpath = mesh_path_lookup(sdata, target_addr);
1160 if (!mpath) {
1161 mpath = mesh_path_add(sdata, target_addr);
1162 if (IS_ERR(mpath)) {
1163 mesh_path_discard_frame(sdata, skb);
1164 return PTR_ERR(mpath);
1165 }
1166 }
1167
1168 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1169 mesh_path_sel_is_hwmp(sdata))
1170 mesh_queue_preq(mpath, PREQ_Q_F_START);
1171
1172 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1173 skb_to_free = skb_dequeue(&mpath->frame_queue);
1174
1175 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
1176 ieee80211_set_qos_hdr(sdata, skb);
1177 skb_queue_tail(&mpath->frame_queue, skb);
1178 if (skb_to_free)
1179 mesh_path_discard_frame(sdata, skb_to_free);
1180
1181 return -ENOENT;
1182 }
1183
1184 /**
1185 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
1186 * @skb: 802.11 frame to be sent
1187 * @sdata: network subif the frame will be sent through
1188 *
1189 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
1190 * And if so, set the RA (addr1) to it to transmit to this node directly,
1191 * avoiding PREQ/PREP path discovery.
1192 *
1193 * Returns: 0 if the next hop was found and -ENOENT otherwise.
1194 */
mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1195 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
1196 struct sk_buff *skb)
1197 {
1198 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1199 struct sta_info *sta;
1200
1201 if (is_multicast_ether_addr(hdr->addr1))
1202 return -ENOENT;
1203
1204 rcu_read_lock();
1205 sta = sta_info_get(sdata, hdr->addr3);
1206
1207 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
1208 rcu_read_unlock();
1209 return -ENOENT;
1210 }
1211 rcu_read_unlock();
1212
1213 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1214 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1215 return 0;
1216 }
1217
1218 /**
1219 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1220 * this function is considered "using" the associated mpath, so preempt a path
1221 * refresh if this mpath expires soon.
1222 *
1223 * @skb: 802.11 frame to be sent
1224 * @sdata: network subif the frame will be sent through
1225 *
1226 * Returns: 0 if the next hop was found. Nonzero otherwise.
1227 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1228 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1229 struct sk_buff *skb)
1230 {
1231 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1232 struct mesh_path *mpath;
1233 struct sta_info *next_hop;
1234 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1235 u8 *target_addr = hdr->addr3;
1236
1237 if (ifmsh->mshcfg.dot11MeshNolearn &&
1238 !mesh_nexthop_lookup_nolearn(sdata, skb))
1239 return 0;
1240
1241 mpath = mesh_path_lookup(sdata, target_addr);
1242 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1243 return -ENOENT;
1244
1245 if (time_after(jiffies,
1246 mpath->exp_time -
1247 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1248 ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
1249 !(mpath->flags & MESH_PATH_RESOLVING) &&
1250 !(mpath->flags & MESH_PATH_FIXED))
1251 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1252
1253 next_hop = rcu_dereference(mpath->next_hop);
1254 if (next_hop) {
1255 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1256 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1257 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1258 return 0;
1259 }
1260
1261 return -ENOENT;
1262 }
1263
mesh_path_timer(struct timer_list * t)1264 void mesh_path_timer(struct timer_list *t)
1265 {
1266 struct mesh_path *mpath = from_timer(mpath, t, timer);
1267 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1268 int ret;
1269
1270 if (sdata->local->quiescing)
1271 return;
1272
1273 spin_lock_bh(&mpath->state_lock);
1274 if (mpath->flags & MESH_PATH_RESOLVED ||
1275 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1276 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1277 spin_unlock_bh(&mpath->state_lock);
1278 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1279 ++mpath->discovery_retries;
1280 mpath->discovery_timeout *= 2;
1281 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1282 spin_unlock_bh(&mpath->state_lock);
1283 mesh_queue_preq(mpath, 0);
1284 } else {
1285 mpath->flags &= ~(MESH_PATH_RESOLVING |
1286 MESH_PATH_RESOLVED |
1287 MESH_PATH_REQ_QUEUED);
1288 mpath->exp_time = jiffies;
1289 spin_unlock_bh(&mpath->state_lock);
1290 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1291 ret = mesh_path_send_to_gates(mpath);
1292 if (ret)
1293 mhwmp_dbg(sdata, "no gate was reachable\n");
1294 } else
1295 mesh_path_flush_pending(mpath);
1296 }
1297 }
1298
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1299 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1300 {
1301 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1302 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1303 u8 flags, target_flags = 0;
1304
1305 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1306 ? RANN_FLAG_IS_GATE : 0;
1307
1308 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1309 case IEEE80211_PROACTIVE_RANN:
1310 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1311 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1312 0, ifmsh->mshcfg.element_ttl,
1313 interval, 0, 0, sdata);
1314 break;
1315 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1316 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1317 fallthrough;
1318 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1319 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1320 target_flags |= IEEE80211_PREQ_TO_FLAG |
1321 IEEE80211_PREQ_USN_FLAG;
1322 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1323 ++ifmsh->sn, target_flags,
1324 (u8 *) broadcast_addr, 0, broadcast_addr,
1325 0, ifmsh->mshcfg.element_ttl, interval,
1326 0, ifmsh->preq_id++, sdata);
1327 break;
1328 default:
1329 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1330 return;
1331 }
1332 }
1333