forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathrx.c
3670 lines (3127 loc) · 102 KB
/
rx.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 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <[email protected]>
* Copyright 2007-2010 Johannes Berg <[email protected]>
* Copyright 2013-2014 Intel Mobile Communications GmbH
*
* 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/jiffies.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "led.h"
#include "mesh.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"
#include "rate.h"
/*
* monitor mode reception
*
* This function cleans up the SKB, i.e. it removes all the stuff
* only useful for monitoring.
*/
static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
struct sk_buff *skb,
unsigned int rtap_vendor_space)
{
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
if (likely(skb->len > FCS_LEN))
__pskb_trim(skb, skb->len - FCS_LEN);
else {
/* driver bug */
WARN_ON(1);
dev_kfree_skb(skb);
return NULL;
}
}
__pskb_pull(skb, rtap_vendor_space);
return skb;
}
static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len,
unsigned int rtap_vendor_space)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr;
hdr = (void *)(skb->data + rtap_vendor_space);
if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
RX_FLAG_FAILED_PLCP_CRC |
RX_FLAG_AMPDU_IS_ZEROLEN))
return true;
if (unlikely(skb->len < 16 + present_fcs_len + rtap_vendor_space))
return true;
if (ieee80211_is_ctl(hdr->frame_control) &&
!ieee80211_is_pspoll(hdr->frame_control) &&
!ieee80211_is_back_req(hdr->frame_control))
return true;
return false;
}
static int
ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
struct ieee80211_rx_status *status,
struct sk_buff *skb)
{
int len;
/* always present fields */
len = sizeof(struct ieee80211_radiotap_header) + 8;
/* allocate extra bitmaps */
if (status->chains)
len += 4 * hweight8(status->chains);
if (ieee80211_have_rx_timestamp(status)) {
len = ALIGN(len, 8);
len += 8;
}
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
len += 1;
/* antenna field, if we don't have per-chain info */
if (!status->chains)
len += 1;
/* padding for RX_FLAGS if necessary */
len = ALIGN(len, 2);
if (status->flag & RX_FLAG_HT) /* HT info */
len += 3;
if (status->flag & RX_FLAG_AMPDU_DETAILS) {
len = ALIGN(len, 4);
len += 8;
}
if (status->flag & RX_FLAG_VHT) {
len = ALIGN(len, 2);
len += 12;
}
if (status->chains) {
/* antenna and antenna signal fields */
len += 2 * hweight8(status->chains);
}
if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
struct ieee80211_vendor_radiotap *rtap = (void *)skb->data;
/* vendor presence bitmap */
len += 4;
/* alignment for fixed 6-byte vendor data header */
len = ALIGN(len, 2);
/* vendor data header */
len += 6;
if (WARN_ON(rtap->align == 0))
rtap->align = 1;
len = ALIGN(len, rtap->align);
len += rtap->len + rtap->pad;
}
return len;
}
/*
* ieee80211_add_rx_radiotap_header - add radiotap header
*
* add a radiotap header containing all the fields which the hardware provided.
*/
static void
ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
struct sk_buff *skb,
struct ieee80211_rate *rate,
int rtap_len, bool has_fcs)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_radiotap_header *rthdr;
unsigned char *pos;
__le32 *it_present;
u32 it_present_val;
u16 rx_flags = 0;
u16 channel_flags = 0;
int mpdulen, chain;
unsigned long chains = status->chains;
struct ieee80211_vendor_radiotap rtap = {};
if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
rtap = *(struct ieee80211_vendor_radiotap *)skb->data;
/* rtap.len and rtap.pad are undone immediately */
skb_pull(skb, sizeof(rtap) + rtap.len + rtap.pad);
}
mpdulen = skb->len;
if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
mpdulen += FCS_LEN;
rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
memset(rthdr, 0, rtap_len - rtap.len - rtap.pad);
it_present = &rthdr->it_present;
/* radiotap header, set always present flags */
rthdr->it_len = cpu_to_le16(rtap_len);
it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
BIT(IEEE80211_RADIOTAP_CHANNEL) |
BIT(IEEE80211_RADIOTAP_RX_FLAGS);
if (!status->chains)
it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
it_present_val |=
BIT(IEEE80211_RADIOTAP_EXT) |
BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
put_unaligned_le32(it_present_val, it_present);
it_present++;
it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
}
if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
it_present_val |= BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE) |
BIT(IEEE80211_RADIOTAP_EXT);
put_unaligned_le32(it_present_val, it_present);
it_present++;
it_present_val = rtap.present;
}
put_unaligned_le32(it_present_val, it_present);
pos = (void *)(it_present + 1);
/* the order of the following fields is important */
/* IEEE80211_RADIOTAP_TSFT */
if (ieee80211_have_rx_timestamp(status)) {
/* padding */
while ((pos - (u8 *)rthdr) & 7)
*pos++ = 0;
put_unaligned_le64(
ieee80211_calculate_rx_timestamp(local, status,
mpdulen, 0),
pos);
rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
pos += 8;
}
/* IEEE80211_RADIOTAP_FLAGS */
if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
*pos |= IEEE80211_RADIOTAP_F_FCS;
if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
*pos |= IEEE80211_RADIOTAP_F_BADFCS;
if (status->flag & RX_FLAG_SHORTPRE)
*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
pos++;
/* IEEE80211_RADIOTAP_RATE */
if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
/*
* Without rate information don't add it. If we have,
* MCS information is a separate field in radiotap,
* added below. The byte here is needed as padding
* for the channel though, so initialise it to 0.
*/
*pos = 0;
} else {
int shift = 0;
rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
if (status->flag & RX_FLAG_10MHZ)
shift = 1;
else if (status->flag & RX_FLAG_5MHZ)
shift = 2;
*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
}
pos++;
/* IEEE80211_RADIOTAP_CHANNEL */
put_unaligned_le16(status->freq, pos);
pos += 2;
if (status->flag & RX_FLAG_10MHZ)
channel_flags |= IEEE80211_CHAN_HALF;
else if (status->flag & RX_FLAG_5MHZ)
channel_flags |= IEEE80211_CHAN_QUARTER;
if (status->band == IEEE80211_BAND_5GHZ)
channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
else if (rate)
channel_flags |= IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ;
else
channel_flags |= IEEE80211_CHAN_2GHZ;
put_unaligned_le16(channel_flags, pos);
pos += 2;
/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
*pos = status->signal;
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
pos++;
}
/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
if (!status->chains) {
/* IEEE80211_RADIOTAP_ANTENNA */
*pos = status->antenna;
pos++;
}
/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
/* IEEE80211_RADIOTAP_RX_FLAGS */
/* ensure 2 byte alignment for the 2 byte field as required */
if ((pos - (u8 *)rthdr) & 1)
*pos++ = 0;
if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
put_unaligned_le16(rx_flags, pos);
pos += 2;
if (status->flag & RX_FLAG_HT) {
unsigned int stbc;
rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
*pos++ = local->hw.radiotap_mcs_details;
*pos = 0;
if (status->flag & RX_FLAG_SHORT_GI)
*pos |= IEEE80211_RADIOTAP_MCS_SGI;
if (status->flag & RX_FLAG_40MHZ)
*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
if (status->flag & RX_FLAG_HT_GF)
*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
if (status->flag & RX_FLAG_LDPC)
*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
pos++;
*pos++ = status->rate_idx;
}
if (status->flag & RX_FLAG_AMPDU_DETAILS) {
u16 flags = 0;
/* ensure 4 byte alignment */
while ((pos - (u8 *)rthdr) & 3)
pos++;
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
put_unaligned_le32(status->ampdu_reference, pos);
pos += 4;
if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
if (status->flag & RX_FLAG_AMPDU_IS_LAST)
flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
put_unaligned_le16(flags, pos);
pos += 2;
if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
*pos++ = status->ampdu_delimiter_crc;
else
*pos++ = 0;
*pos++ = 0;
}
if (status->flag & RX_FLAG_VHT) {
u16 known = local->hw.radiotap_vht_details;
rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
put_unaligned_le16(known, pos);
pos += 2;
/* flags */
if (status->flag & RX_FLAG_SHORT_GI)
*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
/* in VHT, STBC is binary */
if (status->flag & RX_FLAG_STBC_MASK)
*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
if (status->vht_flag & RX_VHT_FLAG_BF)
*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
pos++;
/* bandwidth */
if (status->vht_flag & RX_VHT_FLAG_80MHZ)
*pos++ = 4;
else if (status->vht_flag & RX_VHT_FLAG_160MHZ)
*pos++ = 11;
else if (status->flag & RX_FLAG_40MHZ)
*pos++ = 1;
else /* 20 MHz */
*pos++ = 0;
/* MCS/NSS */
*pos = (status->rate_idx << 4) | status->vht_nss;
pos += 4;
/* coding field */
if (status->flag & RX_FLAG_LDPC)
*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
pos++;
/* group ID */
pos++;
/* partial_aid */
pos += 2;
}
for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
*pos++ = status->chain_signal[chain];
*pos++ = chain;
}
if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
/* ensure 2 byte alignment for the vendor field as required */
if ((pos - (u8 *)rthdr) & 1)
*pos++ = 0;
*pos++ = rtap.oui[0];
*pos++ = rtap.oui[1];
*pos++ = rtap.oui[2];
*pos++ = rtap.subns;
put_unaligned_le16(rtap.len, pos);
pos += 2;
/* align the actual payload as requested */
while ((pos - (u8 *)rthdr) & (rtap.align - 1))
*pos++ = 0;
/* data (and possible padding) already follows */
}
}
/*
* This function copies a received frame to all monitor interfaces and
* returns a cleaned-up SKB that no longer includes the FCS nor the
* radiotap header the driver might have added.
*/
static struct sk_buff *
ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
struct ieee80211_rate *rate)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
struct ieee80211_sub_if_data *sdata;
int rt_hdrlen, needed_headroom;
struct sk_buff *skb, *skb2;
struct net_device *prev_dev = NULL;
int present_fcs_len = 0;
unsigned int rtap_vendor_space = 0;
if (unlikely(status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA)) {
struct ieee80211_vendor_radiotap *rtap = (void *)origskb->data;
rtap_vendor_space = sizeof(*rtap) + rtap->len + rtap->pad;
}
/*
* First, we may need to make a copy of the skb because
* (1) we need to modify it for radiotap (if not present), and
* (2) the other RX handlers will modify the skb we got.
*
* We don't need to, of course, if we aren't going to return
* the SKB because it has a bad FCS/PLCP checksum.
*/
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
present_fcs_len = FCS_LEN;
/* ensure hdr->frame_control and vendor radiotap data are in skb head */
if (!pskb_may_pull(origskb, 2 + rtap_vendor_space)) {
dev_kfree_skb(origskb);
return NULL;
}
if (!local->monitors) {
if (should_drop_frame(origskb, present_fcs_len,
rtap_vendor_space)) {
dev_kfree_skb(origskb);
return NULL;
}
return remove_monitor_info(local, origskb, rtap_vendor_space);
}
/* room for the radiotap header based on driver features */
rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, origskb);
needed_headroom = rt_hdrlen - rtap_vendor_space;
if (should_drop_frame(origskb, present_fcs_len, rtap_vendor_space)) {
/* only need to expand headroom if necessary */
skb = origskb;
origskb = NULL;
/*
* This shouldn't trigger often because most devices have an
* RX header they pull before we get here, and that should
* be big enough for our radiotap information. We should
* probably export the length to drivers so that we can have
* them allocate enough headroom to start with.
*/
if (skb_headroom(skb) < needed_headroom &&
pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
dev_kfree_skb(skb);
return NULL;
}
} else {
/*
* Need to make a copy and possibly remove radiotap header
* and FCS from the original.
*/
skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
origskb = remove_monitor_info(local, origskb,
rtap_vendor_space);
if (!skb)
return origskb;
}
/* prepend radiotap information */
ieee80211_add_rx_radiotap_header(local, skb, rate, rt_hdrlen, true);
skb_reset_mac_header(skb);
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->pkt_type = PACKET_OTHERHOST;
skb->protocol = htons(ETH_P_802_2);
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
continue;
if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
continue;
if (!ieee80211_sdata_running(sdata))
continue;
if (prev_dev) {
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2) {
skb2->dev = prev_dev;
netif_receive_skb(skb2);
}
}
prev_dev = sdata->dev;
sdata->dev->stats.rx_packets++;
sdata->dev->stats.rx_bytes += skb->len;
}
if (prev_dev) {
skb->dev = prev_dev;
netif_receive_skb(skb);
} else
dev_kfree_skb(skb);
return origskb;
}
static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
int tid, seqno_idx, security_idx;
/* does the frame have a qos control field? */
if (ieee80211_is_data_qos(hdr->frame_control)) {
u8 *qc = ieee80211_get_qos_ctl(hdr);
/* frame has qos control */
tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
status->rx_flags |= IEEE80211_RX_AMSDU;
seqno_idx = tid;
security_idx = tid;
} else {
/*
* IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
*
* Sequence numbers for management frames, QoS data
* frames with a broadcast/multicast address in the
* Address 1 field, and all non-QoS data frames sent
* by QoS STAs are assigned using an additional single
* modulo-4096 counter, [...]
*
* We also use that counter for non-QoS STAs.
*/
seqno_idx = IEEE80211_NUM_TIDS;
security_idx = 0;
if (ieee80211_is_mgmt(hdr->frame_control))
security_idx = IEEE80211_NUM_TIDS;
tid = 0;
}
rx->seqno_idx = seqno_idx;
rx->security_idx = security_idx;
/* Set skb->priority to 1d tag if highest order bit of TID is not set.
* For now, set skb->priority to 0 for other cases. */
rx->skb->priority = (tid > 7) ? 0 : tid;
}
/**
* DOC: Packet alignment
*
* Drivers always need to pass packets that are aligned to two-byte boundaries
* to the stack.
*
* Additionally, should, if possible, align the payload data in a way that
* guarantees that the contained IP header is aligned to a four-byte
* boundary. In the case of regular frames, this simply means aligning the
* payload to a four-byte boundary (because either the IP header is directly
* contained, or IV/RFC1042 headers that have a length divisible by four are
* in front of it). If the payload data is not properly aligned and the
* architecture doesn't support efficient unaligned operations, mac80211
* will align the data.
*
* With A-MSDU frames, however, the payload data address must yield two modulo
* four because there are 14-byte 802.3 headers within the A-MSDU frames that
* push the IP header further back to a multiple of four again. Thankfully, the
* specs were sane enough this time around to require padding each A-MSDU
* subframe to a length that is a multiple of four.
*
* Padding like Atheros hardware adds which is between the 802.11 header and
* the payload is not supported, the driver is required to move the 802.11
* header to be directly in front of the payload in that case.
*/
static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
WARN_ONCE((unsigned long)rx->skb->data & 1,
"unaligned packet at 0x%p\n", rx->skb->data);
#endif
}
/* rx handlers */
static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (is_multicast_ether_addr(hdr->addr1))
return 0;
return ieee80211_is_robust_mgmt_frame(skb);
}
static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (!is_multicast_ether_addr(hdr->addr1))
return 0;
return ieee80211_is_robust_mgmt_frame(skb);
}
/* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
{
struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
struct ieee80211_mmie *mmie;
struct ieee80211_mmie_16 *mmie16;
if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
return -1;
if (!ieee80211_is_robust_mgmt_frame(skb))
return -1; /* not a robust management frame */
mmie = (struct ieee80211_mmie *)
(skb->data + skb->len - sizeof(*mmie));
if (mmie->element_id == WLAN_EID_MMIE &&
mmie->length == sizeof(*mmie) - 2)
return le16_to_cpu(mmie->key_id);
mmie16 = (struct ieee80211_mmie_16 *)
(skb->data + skb->len - sizeof(*mmie16));
if (skb->len >= 24 + sizeof(*mmie16) &&
mmie16->element_id == WLAN_EID_MMIE &&
mmie16->length == sizeof(*mmie16) - 2)
return le16_to_cpu(mmie16->key_id);
return -1;
}
static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
__le16 fc;
int hdrlen;
u8 keyid;
fc = hdr->frame_control;
hdrlen = ieee80211_hdrlen(fc);
if (skb->len < hdrlen + cs->hdr_len)
return -EINVAL;
skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
keyid &= cs->key_idx_mask;
keyid >>= cs->key_idx_shift;
return keyid;
}
static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
char *dev_addr = rx->sdata->vif.addr;
if (ieee80211_is_data(hdr->frame_control)) {
if (is_multicast_ether_addr(hdr->addr1)) {
if (ieee80211_has_tods(hdr->frame_control) ||
!ieee80211_has_fromds(hdr->frame_control))
return RX_DROP_MONITOR;
if (ether_addr_equal(hdr->addr3, dev_addr))
return RX_DROP_MONITOR;
} else {
if (!ieee80211_has_a4(hdr->frame_control))
return RX_DROP_MONITOR;
if (ether_addr_equal(hdr->addr4, dev_addr))
return RX_DROP_MONITOR;
}
}
/* If there is not an established peer link and this is not a peer link
* establisment frame, beacon or probe, drop the frame.
*/
if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
struct ieee80211_mgmt *mgmt;
if (!ieee80211_is_mgmt(hdr->frame_control))
return RX_DROP_MONITOR;
if (ieee80211_is_action(hdr->frame_control)) {
u8 category;
/* make sure category field is present */
if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
return RX_DROP_MONITOR;
mgmt = (struct ieee80211_mgmt *)hdr;
category = mgmt->u.action.category;
if (category != WLAN_CATEGORY_MESH_ACTION &&
category != WLAN_CATEGORY_SELF_PROTECTED)
return RX_DROP_MONITOR;
return RX_CONTINUE;
}
if (ieee80211_is_probe_req(hdr->frame_control) ||
ieee80211_is_probe_resp(hdr->frame_control) ||
ieee80211_is_beacon(hdr->frame_control) ||
ieee80211_is_auth(hdr->frame_control))
return RX_CONTINUE;
return RX_DROP_MONITOR;
}
return RX_CONTINUE;
}
static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
struct tid_ampdu_rx *tid_agg_rx,
int index,
struct sk_buff_head *frames)
{
struct sk_buff_head *skb_list = &tid_agg_rx->reorder_buf[index];
struct sk_buff *skb;
struct ieee80211_rx_status *status;
lockdep_assert_held(&tid_agg_rx->reorder_lock);
if (skb_queue_empty(skb_list))
goto no_frame;
if (!ieee80211_rx_reorder_ready(skb_list)) {
__skb_queue_purge(skb_list);
goto no_frame;
}
/* release frames from the reorder ring buffer */
tid_agg_rx->stored_mpdu_num--;
while ((skb = __skb_dequeue(skb_list))) {
status = IEEE80211_SKB_RXCB(skb);
status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
__skb_queue_tail(frames, skb);
}
no_frame:
tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
}
static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
struct tid_ampdu_rx *tid_agg_rx,
u16 head_seq_num,
struct sk_buff_head *frames)
{
int index;
lockdep_assert_held(&tid_agg_rx->reorder_lock);
while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
frames);
}
}
/*
* Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
* the skb was added to the buffer longer than this time ago, the earlier
* frames that have not yet been received are assumed to be lost and the skb
* can be released for processing. This may also release other skb's from the
* reorder buffer if there are no additional gaps between the frames.
*
* Callers must hold tid_agg_rx->reorder_lock.
*/
#define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
struct tid_ampdu_rx *tid_agg_rx,
struct sk_buff_head *frames)
{
int index, i, j;
lockdep_assert_held(&tid_agg_rx->reorder_lock);
/* release the buffer until next missing frame */
index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
if (!ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index]) &&
tid_agg_rx->stored_mpdu_num) {
/*
* No buffers ready to be released, but check whether any
* frames in the reorder buffer have timed out.
*/
int skipped = 1;
for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
j = (j + 1) % tid_agg_rx->buf_size) {
if (!ieee80211_rx_reorder_ready(
&tid_agg_rx->reorder_buf[j])) {
skipped++;
continue;
}
if (skipped &&
!time_after(jiffies, tid_agg_rx->reorder_time[j] +
HT_RX_REORDER_BUF_TIMEOUT))
goto set_release_timer;
/* don't leave incomplete A-MSDUs around */
for (i = (index + 1) % tid_agg_rx->buf_size; i != j;
i = (i + 1) % tid_agg_rx->buf_size)
__skb_queue_purge(&tid_agg_rx->reorder_buf[i]);
ht_dbg_ratelimited(sdata,
"release an RX reorder frame due to timeout on earlier frames\n");
ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
frames);
/*
* Increment the head seq# also for the skipped slots.
*/
tid_agg_rx->head_seq_num =
(tid_agg_rx->head_seq_num +
skipped) & IEEE80211_SN_MASK;
skipped = 0;
}
} else while (ieee80211_rx_reorder_ready(
&tid_agg_rx->reorder_buf[index])) {
ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
frames);
index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
}
if (tid_agg_rx->stored_mpdu_num) {
j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
for (; j != (index - 1) % tid_agg_rx->buf_size;
j = (j + 1) % tid_agg_rx->buf_size) {
if (ieee80211_rx_reorder_ready(
&tid_agg_rx->reorder_buf[j]))
break;
}
set_release_timer:
if (!tid_agg_rx->removed)
mod_timer(&tid_agg_rx->reorder_timer,
tid_agg_rx->reorder_time[j] + 1 +
HT_RX_REORDER_BUF_TIMEOUT);
} else {
del_timer(&tid_agg_rx->reorder_timer);
}
}
/*
* As this function belongs to the RX path it must be under
* rcu_read_lock protection. It returns false if the frame
* can be processed immediately, true if it was consumed.
*/
static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
struct tid_ampdu_rx *tid_agg_rx,
struct sk_buff *skb,
struct sk_buff_head *frames)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
u16 sc = le16_to_cpu(hdr->seq_ctrl);
u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
u16 head_seq_num, buf_size;
int index;
bool ret = true;
spin_lock(&tid_agg_rx->reorder_lock);
/*
* Offloaded BA sessions have no known starting sequence number so pick
* one from first Rxed frame for this tid after BA was started.
*/
if (unlikely(tid_agg_rx->auto_seq)) {
tid_agg_rx->auto_seq = false;
tid_agg_rx->ssn = mpdu_seq_num;
tid_agg_rx->head_seq_num = mpdu_seq_num;
}
buf_size = tid_agg_rx->buf_size;
head_seq_num = tid_agg_rx->head_seq_num;
/* frame with out of date sequence number */
if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
dev_kfree_skb(skb);
goto out;
}
/*
* If frame the sequence number exceeds our buffering window
* size release some previous frames to make room for this one.
*/
if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
head_seq_num = ieee80211_sn_inc(
ieee80211_sn_sub(mpdu_seq_num, buf_size));
/* release stored frames up to new head to stack */
ieee80211_release_reorder_frames(sdata, tid_agg_rx,
head_seq_num, frames);
}
/* Now the new frame is always in the range of the reordering buffer */
index = mpdu_seq_num % tid_agg_rx->buf_size;
/* check if we already stored this frame */
if (ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index])) {
dev_kfree_skb(skb);
goto out;
}
/*
* If the current MPDU is in the right order and nothing else
* is stored we can process it directly, no need to buffer it.
* If it is first but there's something stored, we may be able
* to release frames after this one.
*/
if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
tid_agg_rx->stored_mpdu_num == 0) {
if (!(status->flag & RX_FLAG_AMSDU_MORE))
tid_agg_rx->head_seq_num =
ieee80211_sn_inc(tid_agg_rx->head_seq_num);
ret = false;
goto out;
}
/* put the frame in the reordering buffer */
__skb_queue_tail(&tid_agg_rx->reorder_buf[index], skb);
if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
tid_agg_rx->reorder_time[index] = jiffies;
tid_agg_rx->stored_mpdu_num++;
ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
}
out:
spin_unlock(&tid_agg_rx->reorder_lock);
return ret;
}
/*
* Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
* true if the MPDU was buffered, false if it should be processed.
*/
static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
struct sk_buff_head *frames)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_local *local = rx->local;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct sta_info *sta = rx->sta;
struct tid_ampdu_rx *tid_agg_rx;
u16 sc;
u8 tid, ack_policy;
if (!ieee80211_is_data_qos(hdr->frame_control) ||
is_multicast_ether_addr(hdr->addr1))
goto dont_reorder;
/*
* filter the QoS data rx stream according to
* STA/TID and check if this STA/TID is on aggregation
*/
if (!sta)
goto dont_reorder;