forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
mesh_hwmp.c
1264 lines (1127 loc) · 35.7 KB
/
mesh_hwmp.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Author: Luis Carlos Cobo <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/slab.h>
#include <linux/etherdevice.h>
#include <asm/unaligned.h>
#include "wme.h"
#include "mesh.h"
#define TEST_FRAME_LEN 8192
#define MAX_METRIC 0xffffffff
#define ARITH_SHIFT 8
#define LINK_FAIL_THRESH 95
#define MAX_PREQ_QUEUE_LEN 64
static void mesh_queue_preq(struct mesh_path *, u8);
static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le32(preq_elem + offset);
}
static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le16(preq_elem + offset);
}
/* HWMP IE processing macros */
#define AE_F (1<<6)
#define AE_F_SET(x) (*x & AE_F)
#define PREQ_IE_FLAGS(x) (*(x))
#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
#define PREQ_IE_TTL(x) (*(x + 2))
#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
#define PREQ_IE_ORIG_ADDR(x) (x + 7)
#define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
#define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
#define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
#define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
#define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
#define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
#define PREP_IE_TARGET_ADDR(x) (x + 3)
#define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
#define PERR_IE_TTL(x) (*(x))
#define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
#define PERR_IE_TARGET_ADDR(x) (x + 3)
#define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
#define MSEC_TO_TU(x) (x*1000/1024)
#define SN_GT(x, y) ((s32)(y - x) < 0)
#define SN_LT(x, y) ((s32)(x - y) < 0)
#define MAX_SANE_SN_DELTA 32
static inline u32 SN_DELTA(u32 x, u32 y)
{
return x >= y ? x - y : y - x;
}
#define net_traversal_jiffies(s) \
msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
#define default_lifetime(s) \
MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
#define min_preq_int_jiff(s) \
(msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
#define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
#define disc_timeout_jiff(s) \
msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
#define root_path_confirmation_jiffies(s) \
msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
enum mpath_frame_type {
MPATH_PREQ = 0,
MPATH_PREP,
MPATH_PERR,
MPATH_RANN
};
static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
static int 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)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
u8 *pos, ie_len;
int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
sizeof(mgmt->u.action.u.mesh_action);
skb = dev_alloc_skb(local->tx_headroom +
hdr_len +
2 + 37); /* max HWMP IE */
if (!skb)
return -1;
skb_reserve(skb, local->tx_headroom);
mgmt = skb_put_zero(skb, hdr_len);
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
memcpy(mgmt->da, da, ETH_ALEN);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
/* BSSID == SA */
memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
mgmt->u.action.u.mesh_action.action_code =
WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
switch (action) {
case MPATH_PREQ:
mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
ie_len = 37;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PREQ;
break;
case MPATH_PREP:
mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
ie_len = 31;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PREP;
break;
case MPATH_RANN:
mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
ie_len = sizeof(struct ieee80211_rann_ie);
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_RANN;
break;
default:
kfree_skb(skb);
return -ENOTSUPP;
}
*pos++ = ie_len;
*pos++ = flags;
*pos++ = hop_count;
*pos++ = ttl;
if (action == MPATH_PREP) {
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
} else {
if (action == MPATH_PREQ) {
put_unaligned_le32(preq_id, pos);
pos += 4;
}
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(orig_sn, pos);
pos += 4;
}
put_unaligned_le32(lifetime, pos); /* interval for RANN */
pos += 4;
put_unaligned_le32(metric, pos);
pos += 4;
if (action == MPATH_PREQ) {
*pos++ = 1; /* destination count */
*pos++ = target_flags;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
} else if (action == MPATH_PREP) {
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(orig_sn, pos);
pos += 4;
}
ieee80211_tx_skb(sdata, skb);
return 0;
}
/* Headroom is not adjusted. Caller should ensure that skb has sufficient
* headroom in case the frame is encrypted. */
static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
/* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
skb_set_queue_mapping(skb, IEEE80211_AC_VO);
skb->priority = 7;
info->control.vif = &sdata->vif;
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
ieee80211_set_qos_hdr(sdata, skb);
ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
}
/**
* mesh_path_error_tx - Sends a PERR mesh management frame
*
* @ttl: allowed remaining hops
* @target: broken destination
* @target_sn: SN of the broken destination
* @target_rcode: reason code for this PERR
* @ra: node this frame is addressed to
* @sdata: local mesh subif
*
* Note: This function may be called with driver locks taken that the driver
* also acquires in the TX path. To avoid a deadlock we don't transmit the
* frame directly but add it to the pending queue instead.
*/
int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
u8 ttl, const u8 *target, u32 target_sn,
u16 target_rcode, const u8 *ra)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_mgmt *mgmt;
u8 *pos, ie_len;
int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
sizeof(mgmt->u.action.u.mesh_action);
if (time_before(jiffies, ifmsh->next_perr))
return -EAGAIN;
skb = dev_alloc_skb(local->tx_headroom +
sdata->encrypt_headroom +
IEEE80211_ENCRYPT_TAILROOM +
hdr_len +
2 + 15 /* PERR IE */);
if (!skb)
return -1;
skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
mgmt = skb_put_zero(skb, hdr_len);
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
memcpy(mgmt->da, ra, ETH_ALEN);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
/* BSSID == SA */
memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
mgmt->u.action.u.mesh_action.action_code =
WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
ie_len = 15;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PERR;
*pos++ = ie_len;
/* ttl */
*pos++ = ttl;
/* number of destinations */
*pos++ = 1;
/* Flags field has AE bit only as defined in
* sec 8.4.2.117 IEEE802.11-2012
*/
*pos = 0;
pos++;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
put_unaligned_le16(target_rcode, pos);
/* see note in function header */
prepare_frame_for_deferred_tx(sdata, skb);
ifmsh->next_perr = TU_TO_EXP_TIME(
ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
ieee80211_add_pending_skb(local, skb);
return 0;
}
void ieee80211s_update_metric(struct ieee80211_local *local,
struct sta_info *sta, struct sk_buff *skb)
{
struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
int failed;
if (!ieee80211_is_data(hdr->frame_control))
return;
failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
/* moving average, scaled to 100.
* feed failure as 100 and success as 0
*/
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
LINK_FAIL_THRESH)
mesh_plink_broken(sta);
}
static u32 airtime_link_metric_get(struct ieee80211_local *local,
struct sta_info *sta)
{
struct rate_info rinfo;
/* This should be adjusted for each device */
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
int rate, err;
u32 tx_time, estimated_retx;
u64 result;
unsigned long fail_avg =
ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
/* Try to get rate based on HW/SW RC algorithm.
* Rate is returned in units of Kbps, correct this
* to comply with airtime calculation units
* Round up in case we get rate < 100Kbps
*/
rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
if (rate) {
err = 0;
} else {
if (fail_avg > LINK_FAIL_THRESH)
return MAX_METRIC;
sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
rate = cfg80211_calculate_bitrate(&rinfo);
if (WARN_ON(!rate))
return MAX_METRIC;
err = (fail_avg << ARITH_SHIFT) / 100;
}
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
*/
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
return (u32)result;
}
/**
* hwmp_route_info_get - Update routing info to originator and transmitter
*
* @sdata: local mesh subif
* @mgmt: mesh management frame
* @hwmp_ie: hwmp information element (PREP or PREQ)
* @action: type of hwmp ie
*
* This function updates the path routing information to the originator and the
* transmitter of a HWMP PREQ or PREP frame.
*
* Returns: metric to frame originator or 0 if the frame should not be further
* processed
*
* Notes: this function is the only place (besides user-provided info) where
* path routing information is updated.
*/
static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const u8 *hwmp_ie, enum mpath_frame_type action)
{
struct ieee80211_local *local = sdata->local;
struct mesh_path *mpath;
struct sta_info *sta;
bool fresh_info;
const u8 *orig_addr, *ta;
u32 orig_sn, orig_metric;
unsigned long orig_lifetime, exp_time;
u32 last_hop_metric, new_metric;
bool process = true;
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta) {
rcu_read_unlock();
return 0;
}
last_hop_metric = airtime_link_metric_get(local, sta);
/* Update and check originator routing info */
fresh_info = true;
switch (action) {
case MPATH_PREQ:
orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
orig_metric = PREQ_IE_METRIC(hwmp_ie);
break;
case MPATH_PREP:
/* Originator here refers to the MP that was the target in the
* Path Request. We divert from the nomenclature in the draft
* so that we can easily use a single function to gather path
* information from both PREQ and PREP frames.
*/
orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
orig_metric = PREP_IE_METRIC(hwmp_ie);
break;
default:
rcu_read_unlock();
return 0;
}
new_metric = orig_metric + last_hop_metric;
if (new_metric < orig_metric)
new_metric = MAX_METRIC;
exp_time = TU_TO_EXP_TIME(orig_lifetime);
if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
/* This MP is the originator, we are not interested in this
* frame, except for updating transmitter's path info.
*/
process = false;
fresh_info = false;
} else {
mpath = mesh_path_lookup(sdata, orig_addr);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if (mpath->flags & MESH_PATH_FIXED)
fresh_info = false;
else if ((mpath->flags & MESH_PATH_ACTIVE) &&
(mpath->flags & MESH_PATH_SN_VALID)) {
if (SN_GT(mpath->sn, orig_sn) ||
(mpath->sn == orig_sn &&
new_metric >= mpath->metric)) {
process = false;
fresh_info = false;
}
} else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
bool have_sn, newer_sn, bounced;
have_sn = mpath->flags & MESH_PATH_SN_VALID;
newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
bounced = have_sn &&
(SN_DELTA(orig_sn, mpath->sn) >
MAX_SANE_SN_DELTA);
if (!have_sn || newer_sn) {
/* if SN is newer than what we had
* then we can take it */;
} else if (bounced) {
/* if SN is way different than what
* we had then assume the other side
* rebooted or restarted */;
} else {
process = false;
fresh_info = false;
}
}
} else {
mpath = mesh_path_add(sdata, orig_addr);
if (IS_ERR(mpath)) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
mesh_path_assign_nexthop(mpath, sta);
mpath->flags |= MESH_PATH_SN_VALID;
mpath->metric = new_metric;
mpath->sn = orig_sn;
mpath->exp_time = time_after(mpath->exp_time, exp_time)
? mpath->exp_time : exp_time;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
/* init it at a low value - 0 start is tricky */
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
mesh_path_tx_pending(mpath);
/* draft says preq_id should be saved to, but there does
* not seem to be any use for it, skipping by now
*/
} else
spin_unlock_bh(&mpath->state_lock);
}
/* Update and check transmitter routing info */
ta = mgmt->sa;
if (ether_addr_equal(orig_addr, ta))
fresh_info = false;
else {
fresh_info = true;
mpath = mesh_path_lookup(sdata, ta);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if ((mpath->flags & MESH_PATH_FIXED) ||
((mpath->flags & MESH_PATH_ACTIVE) &&
(last_hop_metric > mpath->metric)))
fresh_info = false;
} else {
mpath = mesh_path_add(sdata, ta);
if (IS_ERR(mpath)) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
mesh_path_assign_nexthop(mpath, sta);
mpath->metric = last_hop_metric;
mpath->exp_time = time_after(mpath->exp_time, exp_time)
? mpath->exp_time : exp_time;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
/* init it at a low value - 0 start is tricky */
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
mesh_path_tx_pending(mpath);
} else
spin_unlock_bh(&mpath->state_lock);
}
rcu_read_unlock();
return process ? new_metric : 0;
}
static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const u8 *preq_elem, u32 orig_metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath = NULL;
const u8 *target_addr, *orig_addr;
const u8 *da;
u8 target_flags, ttl, flags;
u32 orig_sn, target_sn, lifetime, target_metric = 0;
bool reply = false;
bool forward = true;
bool root_is_gate;
/* Update target SN, if present */
target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
target_sn = PREQ_IE_TARGET_SN(preq_elem);
orig_sn = PREQ_IE_ORIG_SN(preq_elem);
target_flags = PREQ_IE_TARGET_F(preq_elem);
/* Proactive PREQ gate announcements */
flags = PREQ_IE_FLAGS(preq_elem);
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
if (ether_addr_equal(target_addr, sdata->vif.addr)) {
mhwmp_dbg(sdata, "PREQ is for us\n");
forward = false;
reply = true;
target_metric = 0;
if (time_after(jiffies, ifmsh->last_sn_update +
net_traversal_jiffies(sdata)) ||
time_before(jiffies, ifmsh->last_sn_update)) {
++ifmsh->sn;
ifmsh->last_sn_update = jiffies;
}
target_sn = ifmsh->sn;
} else if (is_broadcast_ether_addr(target_addr) &&
(target_flags & IEEE80211_PREQ_TO_FLAG)) {
rcu_read_lock();
mpath = mesh_path_lookup(sdata, orig_addr);
if (mpath) {
if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
reply = true;
target_addr = sdata->vif.addr;
target_sn = ++ifmsh->sn;
target_metric = 0;
ifmsh->last_sn_update = jiffies;
}
if (root_is_gate)
mesh_path_add_gate(mpath);
}
rcu_read_unlock();
} else {
rcu_read_lock();
mpath = mesh_path_lookup(sdata, target_addr);
if (mpath) {
if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
SN_LT(mpath->sn, target_sn)) {
mpath->sn = target_sn;
mpath->flags |= MESH_PATH_SN_VALID;
} else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) &&
(mpath->flags & MESH_PATH_ACTIVE)) {
reply = true;
target_metric = mpath->metric;
target_sn = mpath->sn;
/* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
target_flags |= IEEE80211_PREQ_TO_FLAG;
}
}
rcu_read_unlock();
}
if (reply) {
lifetime = PREQ_IE_LIFETIME(preq_elem);
ttl = ifmsh->mshcfg.element_ttl;
if (ttl != 0) {
mhwmp_dbg(sdata, "replying to the PREQ\n");
mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
orig_sn, 0, target_addr,
target_sn, mgmt->sa, 0, ttl,
lifetime, target_metric, 0,
sdata);
} else {
ifmsh->mshstats.dropped_frames_ttl++;
}
}
if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
u32 preq_id;
u8 hopcount;
ttl = PREQ_IE_TTL(preq_elem);
lifetime = PREQ_IE_LIFETIME(preq_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
--ttl;
preq_id = PREQ_IE_PREQ_ID(preq_elem);
hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
da = (mpath && mpath->is_root) ?
mpath->rann_snd_addr : broadcast_addr;
if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
target_sn = PREQ_IE_TARGET_SN(preq_elem);
}
mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
orig_sn, target_flags, target_addr,
target_sn, da, hopcount, ttl, lifetime,
orig_metric, preq_id, sdata);
if (!is_multicast_ether_addr(da))
ifmsh->mshstats.fwded_unicast++;
else
ifmsh->mshstats.fwded_mcast++;
ifmsh->mshstats.fwded_frames++;
}
}
static inline struct sta_info *
next_hop_deref_protected(struct mesh_path *mpath)
{
return rcu_dereference_protected(mpath->next_hop,
lockdep_is_held(&mpath->state_lock));
}
static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const u8 *prep_elem, u32 metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
const u8 *target_addr, *orig_addr;
u8 ttl, hopcount, flags;
u8 next_hop[ETH_ALEN];
u32 target_sn, orig_sn, lifetime;
mhwmp_dbg(sdata, "received PREP from %pM\n",
PREP_IE_TARGET_ADDR(prep_elem));
orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
if (ether_addr_equal(orig_addr, sdata->vif.addr))
/* destination, no forwarding required */
return;
if (!ifmsh->mshcfg.dot11MeshForwarding)
return;
ttl = PREP_IE_TTL(prep_elem);
if (ttl <= 1) {
sdata->u.mesh.mshstats.dropped_frames_ttl++;
return;
}
rcu_read_lock();
mpath = mesh_path_lookup(sdata, orig_addr);
if (mpath)
spin_lock_bh(&mpath->state_lock);
else
goto fail;
if (!(mpath->flags & MESH_PATH_ACTIVE)) {
spin_unlock_bh(&mpath->state_lock);
goto fail;
}
memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
spin_unlock_bh(&mpath->state_lock);
--ttl;
flags = PREP_IE_FLAGS(prep_elem);
lifetime = PREP_IE_LIFETIME(prep_elem);
hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
target_addr = PREP_IE_TARGET_ADDR(prep_elem);
target_sn = PREP_IE_TARGET_SN(prep_elem);
orig_sn = PREP_IE_ORIG_SN(prep_elem);
mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
target_addr, target_sn, next_hop, hopcount,
ttl, lifetime, metric, 0, sdata);
rcu_read_unlock();
sdata->u.mesh.mshstats.fwded_unicast++;
sdata->u.mesh.mshstats.fwded_frames++;
return;
fail:
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
}
static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const u8 *perr_elem)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl;
const u8 *ta, *target_addr;
u32 target_sn;
u16 target_rcode;
ta = mgmt->sa;
ttl = PERR_IE_TTL(perr_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
target_addr = PERR_IE_TARGET_ADDR(perr_elem);
target_sn = PERR_IE_TARGET_SN(perr_elem);
target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
rcu_read_lock();
mpath = mesh_path_lookup(sdata, target_addr);
if (mpath) {
struct sta_info *sta;
spin_lock_bh(&mpath->state_lock);
sta = next_hop_deref_protected(mpath);
if (mpath->flags & MESH_PATH_ACTIVE &&
ether_addr_equal(ta, sta->sta.addr) &&
!(mpath->flags & MESH_PATH_FIXED) &&
(!(mpath->flags & MESH_PATH_SN_VALID) ||
SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
mpath->flags &= ~MESH_PATH_ACTIVE;
if (target_sn != 0)
mpath->sn = target_sn;
else
mpath->sn += 1;
spin_unlock_bh(&mpath->state_lock);
if (!ifmsh->mshcfg.dot11MeshForwarding)
goto endperr;
mesh_path_error_tx(sdata, ttl, target_addr,
target_sn, target_rcode,
broadcast_addr);
} else
spin_unlock_bh(&mpath->state_lock);
}
endperr:
rcu_read_unlock();
}
static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct mesh_path *mpath;
u8 ttl, flags, hopcount;
const u8 *orig_addr;
u32 orig_sn, metric, metric_txsta, interval;
bool root_is_gate;
ttl = rann->rann_ttl;
flags = rann->rann_flags;
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
orig_addr = rann->rann_addr;
orig_sn = le32_to_cpu(rann->rann_seq);
interval = le32_to_cpu(rann->rann_interval);
hopcount = rann->rann_hopcount;
hopcount++;
metric = le32_to_cpu(rann->rann_metric);
/* Ignore our own RANNs */
if (ether_addr_equal(orig_addr, sdata->vif.addr))
return;
mhwmp_dbg(sdata,
"received RANN from %pM via neighbour %pM (is_gate=%d)\n",
orig_addr, mgmt->sa, root_is_gate);
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta) {
rcu_read_unlock();
return;
}
metric_txsta = airtime_link_metric_get(local, sta);
mpath = mesh_path_lookup(sdata, orig_addr);
if (!mpath) {
mpath = mesh_path_add(sdata, orig_addr);
if (IS_ERR(mpath)) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
}
if (!(SN_LT(mpath->sn, orig_sn)) &&
!(mpath->sn == orig_sn && metric < mpath->rann_metric)) {
rcu_read_unlock();
return;
}
if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
(time_after(jiffies, mpath->last_preq_to_root +
root_path_confirmation_jiffies(sdata)) ||
time_before(jiffies, mpath->last_preq_to_root))) &&
!(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
mhwmp_dbg(sdata,
"time to refresh root mpath %pM\n",
orig_addr);
mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
mpath->last_preq_to_root = jiffies;
}
mpath->sn = orig_sn;
mpath->rann_metric = metric + metric_txsta;
mpath->is_root = true;
/* Recording RANNs sender address to send individually
* addressed PREQs destined for root mesh STA */
memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
if (root_is_gate)
mesh_path_add_gate(mpath);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
rcu_read_unlock();
return;
}
ttl--;
if (ifmsh->mshcfg.dot11MeshForwarding) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
orig_sn, 0, NULL, 0, broadcast_addr,
hopcount, ttl, interval,
metric + metric_txsta, 0, sdata);
}
rcu_read_unlock();
}
void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len)
{
struct ieee802_11_elems elems;
size_t baselen;
u32 path_metric;
struct sta_info *sta;
/* need action_code */
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return;
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
rcu_read_unlock();
return;
}
rcu_read_unlock();
baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
len - baselen, false, &elems);
if (elems.preq) {
if (elems.preq_len != 37)
/* Right now we support just 1 destination and no AE */
return;
path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
MPATH_PREQ);
if (path_metric)
hwmp_preq_frame_process(sdata, mgmt, elems.preq,
path_metric);
}
if (elems.prep) {
if (elems.prep_len != 31)
/* Right now we support no AE */
return;
path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
MPATH_PREP);
if (path_metric)
hwmp_prep_frame_process(sdata, mgmt, elems.prep,
path_metric);
}
if (elems.perr) {
if (elems.perr_len != 15)
/* Right now we support only one destination per PERR */
return;
hwmp_perr_frame_process(sdata, mgmt, elems.perr);
}
if (elems.rann)
hwmp_rann_frame_process(sdata, mgmt, elems.rann);
}
/**
* mesh_queue_preq - queue a PREQ to a given destination
*
* @mpath: mesh path to discover
* @flags: special attributes of the PREQ to be sent
*
* Locking: the function must be called from within a rcu read lock block.
*
*/
static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_preq_queue *preq_node;
preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
if (!preq_node) {
mhwmp_dbg(sdata, "could not allocate PREQ node\n");
return;
}
spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
kfree(preq_node);
if (printk_ratelimit())
mhwmp_dbg(sdata, "PREQ node queue full\n");
return;
}
spin_lock(&mpath->state_lock);
if (mpath->flags & MESH_PATH_REQ_QUEUED) {
spin_unlock(&mpath->state_lock);
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
kfree(preq_node);
return;
}
memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
preq_node->flags = flags;
mpath->flags |= MESH_PATH_REQ_QUEUED;
spin_unlock(&mpath->state_lock);
list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
++ifmsh->preq_queue_len;
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
else if (time_before(jiffies, ifmsh->last_preq)) {
/* avoid long wait if did not send preqs for a long time
* and jiffies wrapped around
*/
ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
} else
mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
min_preq_int_jiff(sdata));
}