1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/slab.h>
11 #include <linux/etherdevice.h>
12 #include <asm/unaligned.h>
13 #include "wme.h"
14 #include "mesh.h"
15
16 #define TEST_FRAME_LEN 8192
17 #define MAX_METRIC 0xffffffff
18 #define ARITH_SHIFT 8
19 #define LINK_FAIL_THRESH 95
20
21 #define MAX_PREQ_QUEUE_LEN 64
22
23 static void mesh_queue_preq(struct mesh_path *, u8);
24
u32_field_get(const u8 * preq_elem,int offset,bool ae)25 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
26 {
27 if (ae)
28 offset += 6;
29 return get_unaligned_le32(preq_elem + offset);
30 }
31
u16_field_get(const u8 * preq_elem,int offset,bool ae)32 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
33 {
34 if (ae)
35 offset += 6;
36 return get_unaligned_le16(preq_elem + offset);
37 }
38
39 /* HWMP IE processing macros */
40 #define AE_F (1<<6)
41 #define AE_F_SET(x) (*x & AE_F)
42 #define PREQ_IE_FLAGS(x) (*(x))
43 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
44 #define PREQ_IE_TTL(x) (*(x + 2))
45 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
46 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
47 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
48 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
49 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
50 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
51 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
52 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
53
54
55 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
56 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
57 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
58 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
59 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
60 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
61 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
62 #define PREP_IE_TARGET_ADDR(x) (x + 3)
63 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
64
65 #define PERR_IE_TTL(x) (*(x))
66 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
67 #define PERR_IE_TARGET_ADDR(x) (x + 3)
68 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
69 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
70
71 #define MSEC_TO_TU(x) (x*1000/1024)
72 #define SN_GT(x, y) ((s32)(y - x) < 0)
73 #define SN_LT(x, y) ((s32)(x - y) < 0)
74 #define MAX_SANE_SN_DELTA 32
75
SN_DELTA(u32 x,u32 y)76 static inline u32 SN_DELTA(u32 x, u32 y)
77 {
78 return x >= y ? x - y : y - x;
79 }
80
81 #define net_traversal_jiffies(s) \
82 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
83 #define default_lifetime(s) \
84 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
85 #define min_preq_int_jiff(s) \
86 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
87 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
88 #define disc_timeout_jiff(s) \
89 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
90 #define root_path_confirmation_jiffies(s) \
91 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
92
93 enum mpath_frame_type {
94 MPATH_PREQ = 0,
95 MPATH_PREP,
96 MPATH_PERR,
97 MPATH_RANN
98 };
99
100 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
101
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)102 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
103 const u8 *orig_addr, u32 orig_sn,
104 u8 target_flags, const u8 *target,
105 u32 target_sn, const u8 *da,
106 u8 hop_count, u8 ttl,
107 u32 lifetime, u32 metric, u32 preq_id,
108 struct ieee80211_sub_if_data *sdata)
109 {
110 struct ieee80211_local *local = sdata->local;
111 struct sk_buff *skb;
112 struct ieee80211_mgmt *mgmt;
113 u8 *pos, ie_len;
114 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
115 sizeof(mgmt->u.action.u.mesh_action);
116
117 skb = dev_alloc_skb(local->tx_headroom +
118 hdr_len +
119 2 + 37); /* max HWMP IE */
120 if (!skb)
121 return -1;
122 skb_reserve(skb, local->tx_headroom);
123 mgmt = skb_put_zero(skb, hdr_len);
124 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
125 IEEE80211_STYPE_ACTION);
126
127 memcpy(mgmt->da, da, ETH_ALEN);
128 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
129 /* BSSID == SA */
130 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
131 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
132 mgmt->u.action.u.mesh_action.action_code =
133 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
134
135 switch (action) {
136 case MPATH_PREQ:
137 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
138 ie_len = 37;
139 pos = skb_put(skb, 2 + ie_len);
140 *pos++ = WLAN_EID_PREQ;
141 break;
142 case MPATH_PREP:
143 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
144 ie_len = 31;
145 pos = skb_put(skb, 2 + ie_len);
146 *pos++ = WLAN_EID_PREP;
147 break;
148 case MPATH_RANN:
149 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
150 ie_len = sizeof(struct ieee80211_rann_ie);
151 pos = skb_put(skb, 2 + ie_len);
152 *pos++ = WLAN_EID_RANN;
153 break;
154 default:
155 kfree_skb(skb);
156 return -ENOTSUPP;
157 }
158 *pos++ = ie_len;
159 *pos++ = flags;
160 *pos++ = hop_count;
161 *pos++ = ttl;
162 if (action == MPATH_PREP) {
163 memcpy(pos, target, ETH_ALEN);
164 pos += ETH_ALEN;
165 put_unaligned_le32(target_sn, pos);
166 pos += 4;
167 } else {
168 if (action == MPATH_PREQ) {
169 put_unaligned_le32(preq_id, pos);
170 pos += 4;
171 }
172 memcpy(pos, orig_addr, ETH_ALEN);
173 pos += ETH_ALEN;
174 put_unaligned_le32(orig_sn, pos);
175 pos += 4;
176 }
177 put_unaligned_le32(lifetime, pos); /* interval for RANN */
178 pos += 4;
179 put_unaligned_le32(metric, pos);
180 pos += 4;
181 if (action == MPATH_PREQ) {
182 *pos++ = 1; /* destination count */
183 *pos++ = target_flags;
184 memcpy(pos, target, ETH_ALEN);
185 pos += ETH_ALEN;
186 put_unaligned_le32(target_sn, pos);
187 pos += 4;
188 } else if (action == MPATH_PREP) {
189 memcpy(pos, orig_addr, ETH_ALEN);
190 pos += ETH_ALEN;
191 put_unaligned_le32(orig_sn, pos);
192 pos += 4;
193 }
194
195 ieee80211_tx_skb(sdata, skb);
196 return 0;
197 }
198
199
200 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
201 * headroom in case the frame is encrypted. */
prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)202 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
203 struct sk_buff *skb)
204 {
205 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
206 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
207
208 skb_reset_mac_header(skb);
209 skb_reset_network_header(skb);
210 skb_reset_transport_header(skb);
211
212 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
213 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
214 skb->priority = 7;
215
216 info->control.vif = &sdata->vif;
217 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
218 ieee80211_set_qos_hdr(sdata, skb);
219 ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
220 }
221
222 /**
223 * mesh_path_error_tx - Sends a PERR mesh management frame
224 *
225 * @ttl: allowed remaining hops
226 * @target: broken destination
227 * @target_sn: SN of the broken destination
228 * @target_rcode: reason code for this PERR
229 * @ra: node this frame is addressed to
230 * @sdata: local mesh subif
231 *
232 * Note: This function may be called with driver locks taken that the driver
233 * also acquires in the TX path. To avoid a deadlock we don't transmit the
234 * frame directly but add it to the pending queue instead.
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 = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
246 sizeof(mgmt->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 sdata->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 + sdata->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
304 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
305
306 /* moving average, scaled to 100.
307 * feed failure as 100 and success as 0
308 */
309 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
310 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
311 LINK_FAIL_THRESH)
312 mesh_plink_broken(sta);
313 }
314
airtime_link_metric_get(struct ieee80211_local * local,struct sta_info * sta)315 static u32 airtime_link_metric_get(struct ieee80211_local *local,
316 struct sta_info *sta)
317 {
318 struct rate_info rinfo;
319 /* This should be adjusted for each device */
320 int device_constant = 1 << ARITH_SHIFT;
321 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
322 int s_unit = 1 << ARITH_SHIFT;
323 int rate, err;
324 u32 tx_time, estimated_retx;
325 u64 result;
326 unsigned long fail_avg =
327 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
328
329 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB)
330 return MAX_METRIC;
331
332 /* Try to get rate based on HW/SW RC algorithm.
333 * Rate is returned in units of Kbps, correct this
334 * to comply with airtime calculation units
335 * Round up in case we get rate < 100Kbps
336 */
337 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
338
339 if (rate) {
340 err = 0;
341 } else {
342 if (fail_avg > LINK_FAIL_THRESH)
343 return MAX_METRIC;
344
345 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
346 rate = cfg80211_calculate_bitrate(&rinfo);
347 if (WARN_ON(!rate))
348 return MAX_METRIC;
349
350 err = (fail_avg << ARITH_SHIFT) / 100;
351 }
352
353 /* bitrate is in units of 100 Kbps, while we need rate in units of
354 * 1Mbps. This will be corrected on tx_time computation.
355 */
356 tx_time = (device_constant + 10 * test_frame_len / rate);
357 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
358 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
359 return (u32)result;
360 }
361
362 /**
363 * hwmp_route_info_get - Update routing info to originator and transmitter
364 *
365 * @sdata: local mesh subif
366 * @mgmt: mesh management frame
367 * @hwmp_ie: hwmp information element (PREP or PREQ)
368 * @action: type of hwmp ie
369 *
370 * This function updates the path routing information to the originator and the
371 * transmitter of a HWMP PREQ or PREP frame.
372 *
373 * Returns: metric to frame originator or 0 if the frame should not be further
374 * processed
375 *
376 * Notes: this function is the only place (besides user-provided info) where
377 * path routing information is updated.
378 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)379 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
380 struct ieee80211_mgmt *mgmt,
381 const u8 *hwmp_ie, enum mpath_frame_type action)
382 {
383 struct ieee80211_local *local = sdata->local;
384 struct mesh_path *mpath;
385 struct sta_info *sta;
386 bool fresh_info;
387 const u8 *orig_addr, *ta;
388 u32 orig_sn, orig_metric;
389 unsigned long orig_lifetime, exp_time;
390 u32 last_hop_metric, new_metric;
391 bool process = true;
392
393 rcu_read_lock();
394 sta = sta_info_get(sdata, mgmt->sa);
395 if (!sta) {
396 rcu_read_unlock();
397 return 0;
398 }
399
400 last_hop_metric = airtime_link_metric_get(local, sta);
401 /* Update and check originator routing info */
402 fresh_info = true;
403
404 switch (action) {
405 case MPATH_PREQ:
406 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
407 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
408 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
409 orig_metric = PREQ_IE_METRIC(hwmp_ie);
410 break;
411 case MPATH_PREP:
412 /* Originator here refers to the MP that was the target in the
413 * Path Request. We divert from the nomenclature in the draft
414 * so that we can easily use a single function to gather path
415 * information from both PREQ and PREP frames.
416 */
417 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
418 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
419 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
420 orig_metric = PREP_IE_METRIC(hwmp_ie);
421 break;
422 default:
423 rcu_read_unlock();
424 return 0;
425 }
426 new_metric = orig_metric + last_hop_metric;
427 if (new_metric < orig_metric)
428 new_metric = MAX_METRIC;
429 exp_time = TU_TO_EXP_TIME(orig_lifetime);
430
431 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
432 /* This MP is the originator, we are not interested in this
433 * frame, except for updating transmitter's path info.
434 */
435 process = false;
436 fresh_info = false;
437 } else {
438 mpath = mesh_path_lookup(sdata, orig_addr);
439 if (mpath) {
440 spin_lock_bh(&mpath->state_lock);
441 if (mpath->flags & MESH_PATH_FIXED)
442 fresh_info = false;
443 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
444 (mpath->flags & MESH_PATH_SN_VALID)) {
445 if (SN_GT(mpath->sn, orig_sn) ||
446 (mpath->sn == orig_sn &&
447 new_metric >= mpath->metric)) {
448 process = false;
449 fresh_info = false;
450 }
451 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
452 bool have_sn, newer_sn, bounced;
453
454 have_sn = mpath->flags & MESH_PATH_SN_VALID;
455 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
456 bounced = have_sn &&
457 (SN_DELTA(orig_sn, mpath->sn) >
458 MAX_SANE_SN_DELTA);
459
460 if (!have_sn || newer_sn) {
461 /* if SN is newer than what we had
462 * then we can take it */;
463 } else if (bounced) {
464 /* if SN is way different than what
465 * we had then assume the other side
466 * rebooted or restarted */;
467 } else {
468 process = false;
469 fresh_info = false;
470 }
471 }
472 } else {
473 mpath = mesh_path_add(sdata, orig_addr);
474 if (IS_ERR(mpath)) {
475 rcu_read_unlock();
476 return 0;
477 }
478 spin_lock_bh(&mpath->state_lock);
479 }
480
481 if (fresh_info) {
482 mesh_path_assign_nexthop(mpath, sta);
483 mpath->flags |= MESH_PATH_SN_VALID;
484 mpath->metric = new_metric;
485 mpath->sn = orig_sn;
486 mpath->exp_time = time_after(mpath->exp_time, exp_time)
487 ? mpath->exp_time : exp_time;
488 mesh_path_activate(mpath);
489 spin_unlock_bh(&mpath->state_lock);
490 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
491 /* init it at a low value - 0 start is tricky */
492 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
493 mesh_path_tx_pending(mpath);
494 /* draft says preq_id should be saved to, but there does
495 * not seem to be any use for it, skipping by now
496 */
497 } else
498 spin_unlock_bh(&mpath->state_lock);
499 }
500
501 /* Update and check transmitter routing info */
502 ta = mgmt->sa;
503 if (ether_addr_equal(orig_addr, ta))
504 fresh_info = false;
505 else {
506 fresh_info = true;
507
508 mpath = mesh_path_lookup(sdata, ta);
509 if (mpath) {
510 spin_lock_bh(&mpath->state_lock);
511 if ((mpath->flags & MESH_PATH_FIXED) ||
512 ((mpath->flags & MESH_PATH_ACTIVE) &&
513 (last_hop_metric > mpath->metric)))
514 fresh_info = false;
515 } else {
516 mpath = mesh_path_add(sdata, ta);
517 if (IS_ERR(mpath)) {
518 rcu_read_unlock();
519 return 0;
520 }
521 spin_lock_bh(&mpath->state_lock);
522 }
523
524 if (fresh_info) {
525 mesh_path_assign_nexthop(mpath, sta);
526 mpath->metric = last_hop_metric;
527 mpath->exp_time = time_after(mpath->exp_time, exp_time)
528 ? mpath->exp_time : exp_time;
529 mesh_path_activate(mpath);
530 spin_unlock_bh(&mpath->state_lock);
531 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
532 /* init it at a low value - 0 start is tricky */
533 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
534 mesh_path_tx_pending(mpath);
535 } else
536 spin_unlock_bh(&mpath->state_lock);
537 }
538
539 rcu_read_unlock();
540
541 return process ? new_metric : 0;
542 }
543
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)544 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
545 struct ieee80211_mgmt *mgmt,
546 const u8 *preq_elem, u32 orig_metric)
547 {
548 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
549 struct mesh_path *mpath = NULL;
550 const u8 *target_addr, *orig_addr;
551 const u8 *da;
552 u8 target_flags, ttl, flags;
553 u32 orig_sn, target_sn, lifetime, target_metric = 0;
554 bool reply = false;
555 bool forward = true;
556 bool root_is_gate;
557
558 /* Update target SN, if present */
559 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
560 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
561 target_sn = PREQ_IE_TARGET_SN(preq_elem);
562 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
563 target_flags = PREQ_IE_TARGET_F(preq_elem);
564 /* Proactive PREQ gate announcements */
565 flags = PREQ_IE_FLAGS(preq_elem);
566 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
567
568 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
569
570 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
571 mhwmp_dbg(sdata, "PREQ is for us\n");
572 forward = false;
573 reply = true;
574 target_metric = 0;
575
576 if (SN_GT(target_sn, ifmsh->sn))
577 ifmsh->sn = target_sn;
578
579 if (time_after(jiffies, ifmsh->last_sn_update +
580 net_traversal_jiffies(sdata)) ||
581 time_before(jiffies, ifmsh->last_sn_update)) {
582 ++ifmsh->sn;
583 ifmsh->last_sn_update = jiffies;
584 }
585 target_sn = ifmsh->sn;
586 } else if (is_broadcast_ether_addr(target_addr) &&
587 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
588 rcu_read_lock();
589 mpath = mesh_path_lookup(sdata, orig_addr);
590 if (mpath) {
591 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
592 reply = true;
593 target_addr = sdata->vif.addr;
594 target_sn = ++ifmsh->sn;
595 target_metric = 0;
596 ifmsh->last_sn_update = jiffies;
597 }
598 if (root_is_gate)
599 mesh_path_add_gate(mpath);
600 }
601 rcu_read_unlock();
602 } else {
603 rcu_read_lock();
604 mpath = mesh_path_lookup(sdata, target_addr);
605 if (mpath) {
606 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
607 SN_LT(mpath->sn, target_sn)) {
608 mpath->sn = target_sn;
609 mpath->flags |= MESH_PATH_SN_VALID;
610 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
611 (mpath->flags & MESH_PATH_ACTIVE)) {
612 reply = true;
613 target_metric = mpath->metric;
614 target_sn = mpath->sn;
615 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
616 target_flags |= IEEE80211_PREQ_TO_FLAG;
617 }
618 }
619 rcu_read_unlock();
620 }
621
622 if (reply) {
623 lifetime = PREQ_IE_LIFETIME(preq_elem);
624 ttl = ifmsh->mshcfg.element_ttl;
625 if (ttl != 0) {
626 mhwmp_dbg(sdata, "replying to the PREQ\n");
627 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
628 orig_sn, 0, target_addr,
629 target_sn, mgmt->sa, 0, ttl,
630 lifetime, target_metric, 0,
631 sdata);
632 } else {
633 ifmsh->mshstats.dropped_frames_ttl++;
634 }
635 }
636
637 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
638 u32 preq_id;
639 u8 hopcount;
640
641 ttl = PREQ_IE_TTL(preq_elem);
642 lifetime = PREQ_IE_LIFETIME(preq_elem);
643 if (ttl <= 1) {
644 ifmsh->mshstats.dropped_frames_ttl++;
645 return;
646 }
647 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
648 --ttl;
649 preq_id = PREQ_IE_PREQ_ID(preq_elem);
650 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
651 da = (mpath && mpath->is_root) ?
652 mpath->rann_snd_addr : broadcast_addr;
653
654 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
655 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
656 target_sn = PREQ_IE_TARGET_SN(preq_elem);
657 }
658
659 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
660 orig_sn, target_flags, target_addr,
661 target_sn, da, hopcount, ttl, lifetime,
662 orig_metric, preq_id, sdata);
663 if (!is_multicast_ether_addr(da))
664 ifmsh->mshstats.fwded_unicast++;
665 else
666 ifmsh->mshstats.fwded_mcast++;
667 ifmsh->mshstats.fwded_frames++;
668 }
669 }
670
671
672 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)673 next_hop_deref_protected(struct mesh_path *mpath)
674 {
675 return rcu_dereference_protected(mpath->next_hop,
676 lockdep_is_held(&mpath->state_lock));
677 }
678
679
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)680 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
681 struct ieee80211_mgmt *mgmt,
682 const u8 *prep_elem, u32 metric)
683 {
684 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
685 struct mesh_path *mpath;
686 const u8 *target_addr, *orig_addr;
687 u8 ttl, hopcount, flags;
688 u8 next_hop[ETH_ALEN];
689 u32 target_sn, orig_sn, lifetime;
690
691 mhwmp_dbg(sdata, "received PREP from %pM\n",
692 PREP_IE_TARGET_ADDR(prep_elem));
693
694 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
695 if (ether_addr_equal(orig_addr, sdata->vif.addr))
696 /* destination, no forwarding required */
697 return;
698
699 if (!ifmsh->mshcfg.dot11MeshForwarding)
700 return;
701
702 ttl = PREP_IE_TTL(prep_elem);
703 if (ttl <= 1) {
704 sdata->u.mesh.mshstats.dropped_frames_ttl++;
705 return;
706 }
707
708 rcu_read_lock();
709 mpath = mesh_path_lookup(sdata, orig_addr);
710 if (mpath)
711 spin_lock_bh(&mpath->state_lock);
712 else
713 goto fail;
714 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
715 spin_unlock_bh(&mpath->state_lock);
716 goto fail;
717 }
718 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
719 spin_unlock_bh(&mpath->state_lock);
720 --ttl;
721 flags = PREP_IE_FLAGS(prep_elem);
722 lifetime = PREP_IE_LIFETIME(prep_elem);
723 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
724 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
725 target_sn = PREP_IE_TARGET_SN(prep_elem);
726 orig_sn = PREP_IE_ORIG_SN(prep_elem);
727
728 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
729 target_addr, target_sn, next_hop, hopcount,
730 ttl, lifetime, metric, 0, sdata);
731 rcu_read_unlock();
732
733 sdata->u.mesh.mshstats.fwded_unicast++;
734 sdata->u.mesh.mshstats.fwded_frames++;
735 return;
736
737 fail:
738 rcu_read_unlock();
739 sdata->u.mesh.mshstats.dropped_frames_no_route++;
740 }
741
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)742 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
743 struct ieee80211_mgmt *mgmt,
744 const u8 *perr_elem)
745 {
746 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
747 struct mesh_path *mpath;
748 u8 ttl;
749 const u8 *ta, *target_addr;
750 u32 target_sn;
751 u16 target_rcode;
752
753 ta = mgmt->sa;
754 ttl = PERR_IE_TTL(perr_elem);
755 if (ttl <= 1) {
756 ifmsh->mshstats.dropped_frames_ttl++;
757 return;
758 }
759 ttl--;
760 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
761 target_sn = PERR_IE_TARGET_SN(perr_elem);
762 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
763
764 rcu_read_lock();
765 mpath = mesh_path_lookup(sdata, target_addr);
766 if (mpath) {
767 struct sta_info *sta;
768
769 spin_lock_bh(&mpath->state_lock);
770 sta = next_hop_deref_protected(mpath);
771 if (mpath->flags & MESH_PATH_ACTIVE &&
772 ether_addr_equal(ta, sta->sta.addr) &&
773 !(mpath->flags & MESH_PATH_FIXED) &&
774 (!(mpath->flags & MESH_PATH_SN_VALID) ||
775 SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
776 mpath->flags &= ~MESH_PATH_ACTIVE;
777 if (target_sn != 0)
778 mpath->sn = target_sn;
779 else
780 mpath->sn += 1;
781 spin_unlock_bh(&mpath->state_lock);
782 if (!ifmsh->mshcfg.dot11MeshForwarding)
783 goto endperr;
784 mesh_path_error_tx(sdata, ttl, target_addr,
785 target_sn, target_rcode,
786 broadcast_addr);
787 } else
788 spin_unlock_bh(&mpath->state_lock);
789 }
790 endperr:
791 rcu_read_unlock();
792 }
793
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)794 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
795 struct ieee80211_mgmt *mgmt,
796 const struct ieee80211_rann_ie *rann)
797 {
798 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
799 struct ieee80211_local *local = sdata->local;
800 struct sta_info *sta;
801 struct mesh_path *mpath;
802 u8 ttl, flags, hopcount;
803 const u8 *orig_addr;
804 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
805 bool root_is_gate;
806
807 ttl = rann->rann_ttl;
808 flags = rann->rann_flags;
809 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
810 orig_addr = rann->rann_addr;
811 orig_sn = le32_to_cpu(rann->rann_seq);
812 interval = le32_to_cpu(rann->rann_interval);
813 hopcount = rann->rann_hopcount;
814 hopcount++;
815 orig_metric = le32_to_cpu(rann->rann_metric);
816
817 /* Ignore our own RANNs */
818 if (ether_addr_equal(orig_addr, sdata->vif.addr))
819 return;
820
821 mhwmp_dbg(sdata,
822 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
823 orig_addr, mgmt->sa, root_is_gate);
824
825 rcu_read_lock();
826 sta = sta_info_get(sdata, mgmt->sa);
827 if (!sta) {
828 rcu_read_unlock();
829 return;
830 }
831
832 last_hop_metric = airtime_link_metric_get(local, sta);
833 new_metric = orig_metric + last_hop_metric;
834 if (new_metric < orig_metric)
835 new_metric = MAX_METRIC;
836
837 mpath = mesh_path_lookup(sdata, orig_addr);
838 if (!mpath) {
839 mpath = mesh_path_add(sdata, orig_addr);
840 if (IS_ERR(mpath)) {
841 rcu_read_unlock();
842 sdata->u.mesh.mshstats.dropped_frames_no_route++;
843 return;
844 }
845 }
846
847 if (!(SN_LT(mpath->sn, orig_sn)) &&
848 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
849 rcu_read_unlock();
850 return;
851 }
852
853 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
854 (time_after(jiffies, mpath->last_preq_to_root +
855 root_path_confirmation_jiffies(sdata)) ||
856 time_before(jiffies, mpath->last_preq_to_root))) &&
857 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
858 mhwmp_dbg(sdata,
859 "time to refresh root mpath %pM\n",
860 orig_addr);
861 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
862 mpath->last_preq_to_root = jiffies;
863 }
864
865 mpath->sn = orig_sn;
866 mpath->rann_metric = new_metric;
867 mpath->is_root = true;
868 /* Recording RANNs sender address to send individually
869 * addressed PREQs destined for root mesh STA */
870 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
871
872 if (root_is_gate)
873 mesh_path_add_gate(mpath);
874
875 if (ttl <= 1) {
876 ifmsh->mshstats.dropped_frames_ttl++;
877 rcu_read_unlock();
878 return;
879 }
880 ttl--;
881
882 if (ifmsh->mshcfg.dot11MeshForwarding) {
883 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
884 orig_sn, 0, NULL, 0, broadcast_addr,
885 hopcount, ttl, interval,
886 new_metric, 0, sdata);
887 }
888
889 rcu_read_unlock();
890 }
891
892
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)893 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
894 struct ieee80211_mgmt *mgmt, size_t len)
895 {
896 struct ieee802_11_elems elems;
897 size_t baselen;
898 u32 path_metric;
899 struct sta_info *sta;
900
901 /* need action_code */
902 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
903 return;
904
905 rcu_read_lock();
906 sta = sta_info_get(sdata, mgmt->sa);
907 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
908 rcu_read_unlock();
909 return;
910 }
911 rcu_read_unlock();
912
913 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
914 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
915 len - baselen, false, &elems);
916
917 if (elems.preq) {
918 if (elems.preq_len != 37)
919 /* Right now we support just 1 destination and no AE */
920 return;
921 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
922 MPATH_PREQ);
923 if (path_metric)
924 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
925 path_metric);
926 }
927 if (elems.prep) {
928 if (elems.prep_len != 31)
929 /* Right now we support no AE */
930 return;
931 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
932 MPATH_PREP);
933 if (path_metric)
934 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
935 path_metric);
936 }
937 if (elems.perr) {
938 if (elems.perr_len != 15)
939 /* Right now we support only one destination per PERR */
940 return;
941 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
942 }
943 if (elems.rann)
944 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
945 }
946
947 /**
948 * mesh_queue_preq - queue a PREQ to a given destination
949 *
950 * @mpath: mesh path to discover
951 * @flags: special attributes of the PREQ to be sent
952 *
953 * Locking: the function must be called from within a rcu read lock block.
954 *
955 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)956 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
957 {
958 struct ieee80211_sub_if_data *sdata = mpath->sdata;
959 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
960 struct mesh_preq_queue *preq_node;
961
962 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
963 if (!preq_node) {
964 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
965 return;
966 }
967
968 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
969 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
970 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
971 kfree(preq_node);
972 if (printk_ratelimit())
973 mhwmp_dbg(sdata, "PREQ node queue full\n");
974 return;
975 }
976
977 spin_lock(&mpath->state_lock);
978 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
979 spin_unlock(&mpath->state_lock);
980 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
981 kfree(preq_node);
982 return;
983 }
984
985 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
986 preq_node->flags = flags;
987
988 mpath->flags |= MESH_PATH_REQ_QUEUED;
989 spin_unlock(&mpath->state_lock);
990
991 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
992 ++ifmsh->preq_queue_len;
993 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
994
995 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
996 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
997
998 else if (time_before(jiffies, ifmsh->last_preq)) {
999 /* avoid long wait if did not send preqs for a long time
1000 * and jiffies wrapped around
1001 */
1002 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
1003 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1004 } else
1005 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
1006 min_preq_int_jiff(sdata));
1007 }
1008
1009 /**
1010 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
1011 *
1012 * @sdata: local mesh subif
1013 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1014 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
1015 {
1016 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1017 struct mesh_preq_queue *preq_node;
1018 struct mesh_path *mpath;
1019 u8 ttl, target_flags = 0;
1020 const u8 *da;
1021 u32 lifetime;
1022
1023 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
1024 if (!ifmsh->preq_queue_len ||
1025 time_before(jiffies, ifmsh->last_preq +
1026 min_preq_int_jiff(sdata))) {
1027 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1028 return;
1029 }
1030
1031 preq_node = list_first_entry(&ifmsh->preq_queue.list,
1032 struct mesh_preq_queue, list);
1033 list_del(&preq_node->list);
1034 --ifmsh->preq_queue_len;
1035 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
1036
1037 rcu_read_lock();
1038 mpath = mesh_path_lookup(sdata, preq_node->dst);
1039 if (!mpath)
1040 goto enddiscovery;
1041
1042 spin_lock_bh(&mpath->state_lock);
1043 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
1044 spin_unlock_bh(&mpath->state_lock);
1045 goto enddiscovery;
1046 }
1047 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1048 if (preq_node->flags & PREQ_Q_F_START) {
1049 if (mpath->flags & MESH_PATH_RESOLVING) {
1050 spin_unlock_bh(&mpath->state_lock);
1051 goto enddiscovery;
1052 } else {
1053 mpath->flags &= ~MESH_PATH_RESOLVED;
1054 mpath->flags |= MESH_PATH_RESOLVING;
1055 mpath->discovery_retries = 0;
1056 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1057 }
1058 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1059 mpath->flags & MESH_PATH_RESOLVED) {
1060 mpath->flags &= ~MESH_PATH_RESOLVING;
1061 spin_unlock_bh(&mpath->state_lock);
1062 goto enddiscovery;
1063 }
1064
1065 ifmsh->last_preq = jiffies;
1066
1067 if (time_after(jiffies, ifmsh->last_sn_update +
1068 net_traversal_jiffies(sdata)) ||
1069 time_before(jiffies, ifmsh->last_sn_update)) {
1070 ++ifmsh->sn;
1071 sdata->u.mesh.last_sn_update = jiffies;
1072 }
1073 lifetime = default_lifetime(sdata);
1074 ttl = sdata->u.mesh.mshcfg.element_ttl;
1075 if (ttl == 0) {
1076 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1077 spin_unlock_bh(&mpath->state_lock);
1078 goto enddiscovery;
1079 }
1080
1081 if (preq_node->flags & PREQ_Q_F_REFRESH)
1082 target_flags |= IEEE80211_PREQ_TO_FLAG;
1083 else
1084 target_flags &= ~IEEE80211_PREQ_TO_FLAG;
1085
1086 spin_unlock_bh(&mpath->state_lock);
1087 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1088 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1089 target_flags, mpath->dst, mpath->sn, da, 0,
1090 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1091 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1092
1093 enddiscovery:
1094 rcu_read_unlock();
1095 kfree(preq_node);
1096 }
1097
1098 /**
1099 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1100 *
1101 * @skb: 802.11 frame to be sent
1102 * @sdata: network subif the frame will be sent through
1103 *
1104 * Lookup next hop for given skb and start path discovery if no
1105 * forwarding information is found.
1106 *
1107 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1108 * skb is freeed here if no mpath could be allocated.
1109 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1110 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1111 struct sk_buff *skb)
1112 {
1113 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1114 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1115 struct mesh_path *mpath;
1116 struct sk_buff *skb_to_free = NULL;
1117 u8 *target_addr = hdr->addr3;
1118 int err = 0;
1119
1120 /* Nulls are only sent to peers for PS and should be pre-addressed */
1121 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1122 return 0;
1123
1124 rcu_read_lock();
1125 err = mesh_nexthop_lookup(sdata, skb);
1126 if (!err)
1127 goto endlookup;
1128
1129 /* no nexthop found, start resolving */
1130 mpath = mesh_path_lookup(sdata, target_addr);
1131 if (!mpath) {
1132 mpath = mesh_path_add(sdata, target_addr);
1133 if (IS_ERR(mpath)) {
1134 mesh_path_discard_frame(sdata, skb);
1135 err = PTR_ERR(mpath);
1136 goto endlookup;
1137 }
1138 }
1139
1140 if (!(mpath->flags & MESH_PATH_RESOLVING) &&
1141 mesh_path_sel_is_hwmp(sdata))
1142 mesh_queue_preq(mpath, PREQ_Q_F_START);
1143
1144 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1145 skb_to_free = skb_dequeue(&mpath->frame_queue);
1146
1147 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1148 ieee80211_set_qos_hdr(sdata, skb);
1149 skb_queue_tail(&mpath->frame_queue, skb);
1150 err = -ENOENT;
1151 if (skb_to_free)
1152 mesh_path_discard_frame(sdata, skb_to_free);
1153
1154 endlookup:
1155 rcu_read_unlock();
1156 return err;
1157 }
1158
1159 /**
1160 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1161 * this function is considered "using" the associated mpath, so preempt a path
1162 * refresh if this mpath expires soon.
1163 *
1164 * @skb: 802.11 frame to be sent
1165 * @sdata: network subif the frame will be sent through
1166 *
1167 * Returns: 0 if the next hop was found. Nonzero otherwise.
1168 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1169 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1170 struct sk_buff *skb)
1171 {
1172 struct mesh_path *mpath;
1173 struct sta_info *next_hop;
1174 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1175 u8 *target_addr = hdr->addr3;
1176 int err = -ENOENT;
1177
1178 rcu_read_lock();
1179 mpath = mesh_path_lookup(sdata, target_addr);
1180
1181 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1182 goto endlookup;
1183
1184 if (time_after(jiffies,
1185 mpath->exp_time -
1186 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1187 ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
1188 !(mpath->flags & MESH_PATH_RESOLVING) &&
1189 !(mpath->flags & MESH_PATH_FIXED))
1190 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1191
1192 next_hop = rcu_dereference(mpath->next_hop);
1193 if (next_hop) {
1194 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1195 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1196 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1197 err = 0;
1198 }
1199
1200 endlookup:
1201 rcu_read_unlock();
1202 return err;
1203 }
1204
mesh_path_timer(unsigned long data)1205 void mesh_path_timer(unsigned long data)
1206 {
1207 struct mesh_path *mpath = (void *) data;
1208 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1209 int ret;
1210
1211 if (sdata->local->quiescing)
1212 return;
1213
1214 spin_lock_bh(&mpath->state_lock);
1215 if (mpath->flags & MESH_PATH_RESOLVED ||
1216 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1217 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1218 spin_unlock_bh(&mpath->state_lock);
1219 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1220 ++mpath->discovery_retries;
1221 mpath->discovery_timeout *= 2;
1222 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1223 spin_unlock_bh(&mpath->state_lock);
1224 mesh_queue_preq(mpath, 0);
1225 } else {
1226 mpath->flags &= ~(MESH_PATH_RESOLVING |
1227 MESH_PATH_RESOLVED |
1228 MESH_PATH_REQ_QUEUED);
1229 mpath->exp_time = jiffies;
1230 spin_unlock_bh(&mpath->state_lock);
1231 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1232 ret = mesh_path_send_to_gates(mpath);
1233 if (ret)
1234 mhwmp_dbg(sdata, "no gate was reachable\n");
1235 } else
1236 mesh_path_flush_pending(mpath);
1237 }
1238 }
1239
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1240 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1241 {
1242 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1243 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1244 u8 flags, target_flags = 0;
1245
1246 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1247 ? RANN_FLAG_IS_GATE : 0;
1248
1249 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1250 case IEEE80211_PROACTIVE_RANN:
1251 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1252 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1253 0, ifmsh->mshcfg.element_ttl,
1254 interval, 0, 0, sdata);
1255 break;
1256 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1257 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1258 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1259 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1260 target_flags |= IEEE80211_PREQ_TO_FLAG |
1261 IEEE80211_PREQ_USN_FLAG;
1262 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1263 ++ifmsh->sn, target_flags,
1264 (u8 *) broadcast_addr, 0, broadcast_addr,
1265 0, ifmsh->mshcfg.element_ttl, interval,
1266 0, ifmsh->preq_id++, sdata);
1267 break;
1268 default:
1269 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1270 return;
1271 }
1272 }
1273