summaryrefslogtreecommitdiffstats
path: root/net/mac80211/tx.c
blob: 1d7dd54aacef31120fa744bef928bd7075ad72c2 (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * 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.
 *
 *
 * Transmit and frame generation functions.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/bitmap.h>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/ieee80211_radiotap.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "ieee80211_i.h"
#include "led.h"
#include "mesh.h"
#include "wep.h"
#include "wpa.h"
#include "wme.h"
#include "rate.h"

#define IEEE80211_TX_OK		0
#define IEEE80211_TX_AGAIN	1
#define IEEE80211_TX_FRAG_AGAIN	2

/* misc utils */

static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
					      struct ieee80211_hdr *hdr)
{
	/* Set the sequence number for this frame. */
	hdr->seq_ctrl = cpu_to_le16(sdata->sequence);

	/* Increase the sequence number. */
	sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
}

#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
static void ieee80211_dump_frame(const char *ifname, const char *title,
				 const struct sk_buff *skb)
{
	const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 fc;
	int hdrlen;
	DECLARE_MAC_BUF(mac);

	printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
	if (skb->len < 4) {
		printk("\n");
		return;
	}

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	if (hdrlen > skb->len)
		hdrlen = skb->len;
	if (hdrlen >= 4)
		printk(" FC=0x%04x DUR=0x%04x",
		       fc, le16_to_cpu(hdr->duration_id));
	if (hdrlen >= 10)
		printk(" A1=%s", print_mac(mac, hdr->addr1));
	if (hdrlen >= 16)
		printk(" A2=%s", print_mac(mac, hdr->addr2));
	if (hdrlen >= 24)
		printk(" A3=%s", print_mac(mac, hdr->addr3));
	if (hdrlen >= 30)
		printk(" A4=%s", print_mac(mac, hdr->addr4));
	printk("\n");
}
#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
static inline void ieee80211_dump_frame(const char *ifname, const char *title,
					struct sk_buff *skb)
{
}
#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */

static u16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
			      int next_frag_len)
{
	int rate, mrate, erp, dur, i;
	struct ieee80211_rate *txrate = tx->rate;
	struct ieee80211_local *local = tx->local;
	struct ieee80211_supported_band *sband;

	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	erp = 0;
	if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
		erp = txrate->flags & IEEE80211_RATE_ERP_G;

	/*
	 * data and mgmt (except PS Poll):
	 * - during CFP: 32768
	 * - during contention period:
	 *   if addr1 is group address: 0
	 *   if more fragments = 0 and addr1 is individual address: time to
	 *      transmit one ACK plus SIFS
	 *   if more fragments = 1 and addr1 is individual address: time to
	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
	 *
	 * IEEE 802.11, 9.6:
	 * - control response frame (CTS or ACK) shall be transmitted using the
	 *   same rate as the immediately previous frame in the frame exchange
	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
	 *   at the highest possible rate belonging to the PHY rates in the
	 *   BSSBasicRateSet
	 */

	if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
		/* TODO: These control frames are not currently sent by
		 * 80211.o, but should they be implemented, this function
		 * needs to be updated to support duration field calculation.
		 *
		 * RTS: time needed to transmit pending data/mgmt frame plus
		 *    one CTS frame plus one ACK frame plus 3 x SIFS
		 * CTS: duration of immediately previous RTS minus time
		 *    required to transmit CTS and its SIFS
		 * ACK: 0 if immediately previous directed data/mgmt had
		 *    more=0, with more=1 duration in ACK frame is duration
		 *    from previous frame minus time needed to transmit ACK
		 *    and its SIFS
		 * PS Poll: BIT(15) | BIT(14) | aid
		 */
		return 0;
	}

	/* data/mgmt */
	if (0 /* FIX: data/mgmt during CFP */)
		return 32768;

	if (group_addr) /* Group address as the destination - no ACK */
		return 0;

	/* Individual destination address:
	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
	 * CTS and ACK frames shall be transmitted using the highest rate in
	 * basic rate set that is less than or equal to the rate of the
	 * immediately previous frame and that is using the same modulation
	 * (CCK or OFDM). If no basic rate set matches with these requirements,
	 * the highest mandatory rate of the PHY that is less than or equal to
	 * the rate of the previous frame is used.
	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
	 */
	rate = -1;
	/* use lowest available if everything fails */
	mrate = sband->bitrates[0].bitrate;
	for (i = 0; i < sband->n_bitrates; i++) {
		struct ieee80211_rate *r = &sband->bitrates[i];

		if (r->bitrate > txrate->bitrate)
			break;

		if (tx->sdata->basic_rates & BIT(i))
			rate = r->bitrate;

		switch (sband->band) {
		case IEEE80211_BAND_2GHZ: {
			u32 flag;
			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
				flag = IEEE80211_RATE_MANDATORY_G;
			else
				flag = IEEE80211_RATE_MANDATORY_B;
			if (r->flags & flag)
				mrate = r->bitrate;
			break;
		}
		case IEEE80211_BAND_5GHZ:
			if (r->flags & IEEE80211_RATE_MANDATORY_A)
				mrate = r->bitrate;
			break;
		case IEEE80211_NUM_BANDS:
			WARN_ON(1);
			break;
		}
	}
	if (rate == -1) {
		/* No matching basic rate found; use highest suitable mandatory
		 * PHY rate */
		rate = mrate;
	}

	/* Time needed to transmit ACK
	 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
	 * to closest integer */

	dur = ieee80211_frame_duration(local, 10, rate, erp,
				tx->sdata->bss_conf.use_short_preamble);

	if (next_frag_len) {
		/* Frame is fragmented: duration increases with time needed to
		 * transmit next fragment plus ACK and 2 x SIFS. */
		dur *= 2; /* ACK + SIFS */
		/* next fragment */
		dur += ieee80211_frame_duration(local, next_frag_len,
				txrate->bitrate, erp,
				tx->sdata->bss_conf.use_short_preamble);
	}

	return dur;
}

static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
					    int queue)
{
	return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}

static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
					    int queue)
{
	return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
}

static int inline is_ieee80211_device(struct net_device *dev,
				      struct net_device *master)
{
	return (wdev_priv(dev->ieee80211_ptr) ==
		wdev_priv(master->ieee80211_ptr));
}

/* tx handlers */

static ieee80211_tx_result
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
	u32 sta_flags;

	if (unlikely(tx->flags & IEEE80211_TX_INJECTED))
		return TX_CONTINUE;

	if (unlikely(tx->local->sta_sw_scanning) &&
	    ((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
	     (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
		return TX_DROP;

	if (tx->sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT)
		return TX_CONTINUE;

	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
		return TX_CONTINUE;

	sta_flags = tx->sta ? tx->sta->flags : 0;

	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
			     tx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
			     (tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
			DECLARE_MAC_BUF(mac);
			printk(KERN_DEBUG "%s: dropped data frame to not "
			       "associated station %s\n",
			       tx->dev->name, print_mac(mac, hdr->addr1));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
			return TX_DROP;
		}
	} else {
		if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
			     tx->local->num_sta == 0 &&
			     tx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS)) {
			/*
			 * No associated STAs - no need to send multicast
			 * frames.
			 */
			return TX_DROP;
		}
		return TX_CONTINUE;
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;

	if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
		ieee80211_include_sequence(tx->sdata, hdr);

	return TX_CONTINUE;
}

/* This function is called whenever the AP is about to exceed the maximum limit
 * of buffered frames for power saving STAs. This situation should not really
 * happen often during normal operation, so dropping the oldest buffered packet
 * from each queue should be OK to make some room for new frames. */
static void purge_old_ps_buffers(struct ieee80211_local *local)
{
	int total = 0, purged = 0;
	struct sk_buff *skb;
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;

	/*
	 * virtual interfaces are protected by RCU
	 */
	rcu_read_lock();

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		struct ieee80211_if_ap *ap;
		if (sdata->dev == local->mdev ||
		    sdata->vif.type != IEEE80211_IF_TYPE_AP)
			continue;
		ap = &sdata->u.ap;
		skb = skb_dequeue(&ap->ps_bc_buf);
		if (skb) {
			purged++;
			dev_kfree_skb(skb);
		}
		total += skb_queue_len(&ap->ps_bc_buf);
	}

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		skb = skb_dequeue(&sta->ps_tx_buf);
		if (skb) {
			purged++;
			dev_kfree_skb(skb);
		}
		total += skb_queue_len(&sta->ps_tx_buf);
	}

	rcu_read_unlock();

	local->total_ps_buffered = total;
	printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
	       wiphy_name(local->hw.wiphy), purged);
}

static ieee80211_tx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
{
	/*
	 * broadcast/multicast frame
	 *
	 * If any of the associated stations is in power save mode,
	 * the frame is buffered to be sent after DTIM beacon frame.
	 * This is done either by the hardware or us.
	 */

	/* not AP/IBSS or ordered frame */
	if (!tx->sdata->bss || (tx->fc & IEEE80211_FCTL_ORDER))
		return TX_CONTINUE;

	/* no stations in PS mode */
	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
		return TX_CONTINUE;

	/* buffered in mac80211 */
	if (tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) {
		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
			purge_old_ps_buffers(tx->local);
		if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
		    AP_MAX_BC_BUFFER) {
			if (net_ratelimit()) {
				printk(KERN_DEBUG "%s: BC TX buffer full - "
				       "dropping the oldest frame\n",
				       tx->dev->name);
			}
			dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
		} else
			tx->local->total_ps_buffered++;
		skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
		return TX_QUEUED;
	}

	/* buffered in hardware */
	tx->control->flags |= IEEE80211_TXCTL_SEND_AFTER_DTIM;

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
{
	struct sta_info *sta = tx->sta;
	DECLARE_MAC_BUF(mac);

	if (unlikely(!sta ||
		     ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
		      (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
		return TX_CONTINUE;

	if (unlikely((sta->flags & WLAN_STA_PS) &&
		     !(sta->flags & WLAN_STA_PSPOLL))) {
		struct ieee80211_tx_packet_data *pkt_data;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
		printk(KERN_DEBUG "STA %s aid %d: PS buffer (entries "
		       "before %d)\n",
		       print_mac(mac, sta->addr), sta->aid,
		       skb_queue_len(&sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
			purge_old_ps_buffers(tx->local);
		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
			if (net_ratelimit()) {
				printk(KERN_DEBUG "%s: STA %s TX "
				       "buffer full - dropping oldest frame\n",
				       tx->dev->name, print_mac(mac, sta->addr));
			}
			dev_kfree_skb(old);
		} else
			tx->local->total_ps_buffered++;

		/* Queue frame to be sent after STA sends an PS Poll frame */
		if (skb_queue_empty(&sta->ps_tx_buf))
			sta_info_set_tim_bit(sta);

		pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
		pkt_data->jiffies = jiffies;
		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
		return TX_QUEUED;
	}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
	else if (unlikely(sta->flags & WLAN_STA_PS)) {
		printk(KERN_DEBUG "%s: STA %s in PS mode, but pspoll "
		       "set -> send frame\n", tx->dev->name,
		       print_mac(mac, sta->addr));
	}
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
	sta->flags &= ~WLAN_STA_PSPOLL;

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
{
	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
		return TX_CONTINUE;

	if (tx->flags & IEEE80211_TX_UNICAST)
		return ieee80211_tx_h_unicast_ps_buf(tx);
	else
		return ieee80211_tx_h_multicast_ps_buf(tx);
}

static ieee80211_tx_result
ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
{
	struct ieee80211_key *key;
	u16 fc = tx->fc;

	if (unlikely(tx->control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
		tx->key = NULL;
	else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
		tx->key = key;
	else if ((key = rcu_dereference(tx->sdata->default_key)))
		tx->key = key;
	else if (tx->sdata->drop_unencrypted &&
		 !(tx->control->flags & IEEE80211_TXCTL_EAPOL_FRAME) &&
		 !(tx->flags & IEEE80211_TX_INJECTED)) {
		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
		return TX_DROP;
	} else
		tx->key = NULL;

	if (tx->key) {
		u16 ftype, stype;

		tx->key->tx_rx_count++;
		/* TODO: add threshold stuff again */

		switch (tx->key->conf.alg) {
		case ALG_WEP:
			ftype = fc & IEEE80211_FCTL_FTYPE;
			stype = fc & IEEE80211_FCTL_STYPE;

			if (ftype == IEEE80211_FTYPE_MGMT &&
			    stype == IEEE80211_STYPE_AUTH)
				break;
		case ALG_TKIP:
		case ALG_CCMP:
			if (!WLAN_FC_DATA_PRESENT(fc))
				tx->key = NULL;
			break;
		}
	}

	if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		tx->control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
	size_t hdrlen, per_fragm, num_fragm, payload_len, left;
	struct sk_buff **frags, *first, *frag;
	int i;
	u16 seq;
	u8 *pos;
	int frag_threshold = tx->local->fragmentation_threshold;

	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
		return TX_CONTINUE;

	first = tx->skb;

	hdrlen = ieee80211_get_hdrlen(tx->fc);
	payload_len = first->len - hdrlen;
	per_fragm = frag_threshold - hdrlen - FCS_LEN;
	num_fragm = DIV_ROUND_UP(payload_len, per_fragm);

	frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
	if (!frags)
		goto fail;

	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
	seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
	pos = first->data + hdrlen + per_fragm;
	left = payload_len - per_fragm;
	for (i = 0; i < num_fragm - 1; i++) {
		struct ieee80211_hdr *fhdr;
		size_t copylen;

		if (left <= 0)
			goto fail;

		/* reserve enough extra head and tail room for possible
		 * encryption */
		frag = frags[i] =
			dev_alloc_skb(tx->local->tx_headroom +
				      frag_threshold +
				      IEEE80211_ENCRYPT_HEADROOM +
				      IEEE80211_ENCRYPT_TAILROOM);
		if (!frag)
			goto fail;
		/* Make sure that all fragments use the same priority so
		 * that they end up using the same TX queue */
		frag->priority = first->priority;
		skb_reserve(frag, tx->local->tx_headroom +
				  IEEE80211_ENCRYPT_HEADROOM);
		fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
		memcpy(fhdr, first->data, hdrlen);
		if (i == num_fragm - 2)
			fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
		fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
		copylen = left > per_fragm ? per_fragm : left;
		memcpy(skb_put(frag, copylen), pos, copylen);

		pos += copylen;
		left -= copylen;
	}
	skb_trim(first, hdrlen + per_fragm);

	tx->num_extra_frag = num_fragm - 1;
	tx->extra_frag = frags;

	return TX_CONTINUE;

 fail:
	printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
	if (frags) {
		for (i = 0; i < num_fragm - 1; i++)
			if (frags[i])
				dev_kfree_skb(frags[i]);
		kfree(frags);
	}
	I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
	return TX_DROP;
}

static ieee80211_tx_result
ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
{
	if (!tx->key)
		return TX_CONTINUE;

	switch (tx->key->conf.alg) {
	case ALG_WEP:
		return ieee80211_crypto_wep_encrypt(tx);
	case ALG_TKIP:
		return ieee80211_crypto_tkip_encrypt(tx);
	case ALG_CCMP:
		return ieee80211_crypto_ccmp_encrypt(tx);
	}

	/* not reached */
	WARN_ON(1);
	return TX_DROP;
}

static ieee80211_tx_result
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
{
	struct rate_selection rsel;
	struct ieee80211_supported_band *sband;

	sband = tx->local->hw.wiphy->bands[tx->local->hw.conf.channel->band];

	if (likely(!tx->rate)) {
		rate_control_get_rate(tx->dev, sband, tx->skb, &rsel);
		tx->rate = rsel.rate;
		if (unlikely(rsel.probe)) {
			tx->control->flags |=
				IEEE80211_TXCTL_RATE_CTRL_PROBE;
			tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
			tx->control->alt_retry_rate = tx->rate;
			tx->rate = rsel.probe;
		} else
			tx->control->alt_retry_rate = NULL;

		if (!tx->rate)
			return TX_DROP;
	} else
		tx->control->alt_retry_rate = NULL;

	if (tx->sdata->bss_conf.use_cts_prot &&
	    (tx->flags & IEEE80211_TX_FRAGMENTED) && rsel.nonerp) {
		tx->last_frag_rate = tx->rate;
		if (rsel.probe)
			tx->flags &= ~IEEE80211_TX_PROBE_LAST_FRAG;
		else
			tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
		tx->rate = rsel.nonerp;
		tx->control->tx_rate = rsel.nonerp;
		tx->control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
	} else {
		tx->last_frag_rate = tx->rate;
		tx->control->tx_rate = tx->rate;
	}
	tx->control->tx_rate = tx->rate;

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_misc(struct ieee80211_tx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
	u16 fc = le16_to_cpu(hdr->frame_control);
	u16 dur;
	struct ieee80211_tx_control *control = tx->control;

	if (!control->retry_limit) {
		if (!is_multicast_ether_addr(hdr->addr1)) {
			if (tx->skb->len + FCS_LEN > tx->local->rts_threshold
			    && tx->local->rts_threshold <
					IEEE80211_MAX_RTS_THRESHOLD) {
				control->flags |=
					IEEE80211_TXCTL_USE_RTS_CTS;
				control->flags |=
					IEEE80211_TXCTL_LONG_RETRY_LIMIT;
				control->retry_limit =
					tx->local->long_retry_limit;
			} else {
				control->retry_limit =
					tx->local->short_retry_limit;
			}
		} else {
			control->retry_limit = 1;
		}
	}

	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		/* Do not use multiple retry rates when sending fragmented
		 * frames.
		 * TODO: The last fragment could still use multiple retry
		 * rates. */
		control->alt_retry_rate = NULL;
	}

	/* Use CTS protection for unicast frames sent using extended rates if
	 * there are associated non-ERP stations and RTS/CTS is not configured
	 * for the frame. */
	if ((tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) &&
	    (tx->rate->flags & IEEE80211_RATE_ERP_G) &&
	    (tx->flags & IEEE80211_TX_UNICAST) &&
	    tx->sdata->bss_conf.use_cts_prot &&
	    !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
		control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;

	/* Transmit data frames using short preambles if the driver supports
	 * short preambles at the selected rate and short preambles are
	 * available on the network at the current point in time. */
	if (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
	    (tx->rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) &&
	    tx->sdata->bss_conf.use_short_preamble &&
	    (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
		tx->control->flags |= IEEE80211_TXCTL_SHORT_PREAMBLE;
	}

	/* Setup duration field for the first fragment of the frame. Duration
	 * for remaining fragments will be updated when they are being sent
	 * to low-level driver in ieee80211_tx(). */
	dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
				 (tx->flags & IEEE80211_TX_FRAGMENTED) ?
				 tx->extra_frag[0]->len : 0);
	hdr->duration_id = cpu_to_le16(dur);

	if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
	    (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
		struct ieee80211_supported_band *sband;
		struct ieee80211_rate *rate, *baserate;
		int idx;

		sband = tx->local->hw.wiphy->bands[
				tx->local->hw.conf.channel->band];

		/* Do not use multiple retry rates when using RTS/CTS */
		control->alt_retry_rate = NULL;

		/* Use min(data rate, max base rate) as CTS/RTS rate */
		rate = tx->rate;
		baserate = NULL;

		for (idx = 0; idx < sband->n_bitrates; idx++) {
			if (sband->bitrates[idx].bitrate > rate->bitrate)
				continue;
			if (tx->sdata->basic_rates & BIT(idx) &&
			    (!baserate ||
			     (baserate->bitrate < sband->bitrates[idx].bitrate)))
				baserate = &sband->bitrates[idx];
		}

		if (baserate)
			control->rts_cts_rate = baserate;
		else
			control->rts_cts_rate = &sband->bitrates[0];
	}

	if (tx->sta) {
		control->aid = tx->sta->aid;
		tx->sta->tx_packets++;
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += tx->skb->len;
		if (tx->extra_frag) {
			int i;
			tx->sta->tx_fragments += tx->num_extra_frag;
			for (i = 0; i < tx->num_extra_frag; i++) {
				tx->sta->tx_bytes +=
					tx->extra_frag[i]->len;
			}
		}
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result
ieee80211_tx_h_load_stats(struct ieee80211_tx_data *tx)
{
	struct ieee80211_local *local = tx->local;
	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u32 load = 0, hdrtime;
	struct ieee80211_rate *rate = tx->rate;

	/* TODO: this could be part of tx_status handling, so that the number
	 * of retries would be known; TX rate should in that case be stored
	 * somewhere with the packet */

	/* Estimate total channel use caused by this frame */

	/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
	 * 1 usec = 1/8 * (1080 / 10) = 13.5 */

	if (tx->channel->band == IEEE80211_BAND_5GHZ ||
	    (tx->channel->band == IEEE80211_BAND_2GHZ &&
	     rate->flags & IEEE80211_RATE_ERP_G))
		hdrtime = CHAN_UTIL_HDR_SHORT;
	else
		hdrtime = CHAN_UTIL_HDR_LONG;

	load = hdrtime;
	if (!is_multicast_ether_addr(hdr->addr1))
		load += hdrtime;

	if (tx->control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
		load += 2 * hdrtime;
	else if (tx->control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
		load += hdrtime;

	/* TODO: optimise again */
	load += skb->len * CHAN_UTIL_RATE_LCM / rate->bitrate;

	if (tx->extra_frag) {
		int i;
		for (i = 0; i < tx->num_extra_frag; i++) {
			load += 2 * hdrtime;
			load += tx->extra_frag[i]->len *
				tx->rate->bitrate;
		}
	}

	/* Divide channel_use by 8 to avoid wrapping around the counter */
	load >>= CHAN_UTIL_SHIFT;
	local->channel_use_raw += load;
	if (tx->sta)
		tx->sta->channel_use_raw += load;
	tx->sdata->channel_use_raw += load;

	return TX_CONTINUE;
}


typedef ieee80211_tx_result (*ieee80211_tx_handler)(struct ieee80211_tx_data *);
static ieee80211_tx_handler ieee80211_tx_handlers[] =
{
	ieee80211_tx_h_check_assoc,
	ieee80211_tx_h_sequence,
	ieee80211_tx_h_ps_buf,
	ieee80211_tx_h_select_key,
	ieee80211_tx_h_michael_mic_add,
	ieee80211_tx_h_fragment,
	ieee80211_tx_h_encrypt,
	ieee80211_tx_h_rate_ctrl,
	ieee80211_tx_h_misc,
	ieee80211_tx_h_load_stats,
	NULL
};

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
static ieee80211_tx_result
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
			      struct sk_buff *skb)
{
	/*
	 * this is the moment to interpret and discard the radiotap header that
	 * must be at the start of the packet injected in Monitor mode
	 *
	 * Need to take some care with endian-ness since radiotap
	 * args are little-endian
	 */

	struct ieee80211_radiotap_iterator iterator;
	struct ieee80211_radiotap_header *rthdr =
		(struct ieee80211_radiotap_header *) skb->data;
	struct ieee80211_supported_band *sband;
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
	struct ieee80211_tx_control *control = tx->control;

	sband = tx->local->hw.wiphy->bands[tx->local->hw.conf.channel->band];

	control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
	tx->flags |= IEEE80211_TX_INJECTED;
	tx->flags &= ~IEEE80211_TX_FRAGMENTED;

	/*
	 * for every radiotap entry that is present
	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
	 * entries present, or -EINVAL on error)
	 */

	while (!ret) {
		int i, target_rate;

		ret = ieee80211_radiotap_iterator_next(&iterator);

		if (ret)
			continue;

		/* see if this argument is something we can use */
		switch (iterator.this_arg_index) {
		/*
		 * You must take care when dereferencing iterator.this_arg
		 * for multibyte types... the pointer is not aligned.  Use
		 * get_unaligned((type *)iterator.this_arg) to dereference
		 * iterator.this_arg for type "type" safely on all arches.
		*/
		case IEEE80211_RADIOTAP_RATE:
			/*
			 * radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
			 * ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
			 */
			target_rate = (*iterator.this_arg) * 5;
			for (i = 0; i < sband->n_bitrates; i++) {
				struct ieee80211_rate *r;

				r = &sband->bitrates[i];

				if (r->bitrate == target_rate) {
					tx->rate = r;
					break;
				}
			}
			break;

		case IEEE80211_RADIOTAP_ANTENNA:
			/*
			 * radiotap uses 0 for 1st ant, mac80211 is 1 for
			 * 1st ant
			 */
			control->antenna_sel_tx = (*iterator.this_arg) + 1;
			break;

#if 0
		case IEEE80211_RADIOTAP_DBM_TX_POWER:
			control->power_level = *iterator.this_arg;
			break;
#endif

		case IEEE80211_RADIOTAP_FLAGS:
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
				/*
				 * this indicates that the skb we have been
				 * handed has the 32-bit FCS CRC at the end...
				 * we should react to that by snipping it off
				 * because it will be recomputed and added
				 * on transmission
				 */
				if (skb->len < (iterator.max_length + FCS_LEN))
					return TX_DROP;

				skb_trim(skb, skb->len - FCS_LEN);
			}
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
				control->flags &=
					~IEEE80211_TXCTL_DO_NOT_ENCRYPT;
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
				tx->flags |= IEEE80211_TX_FRAGMENTED;
			break;

		/*
		 * Please update the file
		 * Documentation/networking/mac80211-injection.txt
		 * when parsing new fields here.
		 */

		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
		return TX_DROP;

	/*
	 * remove the radiotap header
	 * iterator->max_length was sanity-checked against
	 * skb->len by iterator init
	 */
	skb_pull(skb, iterator.max_length);

	return TX_CONTINUE;
}

/*
 * initialises @tx
 */
static ieee80211_tx_result
__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
		       struct sk_buff *skb,
		       struct net_device *dev,
		       struct ieee80211_tx_control *control)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_hdr *hdr;
	struct ieee80211_sub_if_data *sdata;

	int hdrlen;

	memset(tx, 0, sizeof(*tx));
	tx->skb = skb;
	tx->dev = dev; /* use original interface */
	tx->local = local;
	tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	tx->control = control;
	/*
	 * Set this flag (used below to indicate "automatic fragmentation"),
	 * it will be cleared/left by radiotap as desired.
	 */
	tx->flags |= IEEE80211_TX_FRAGMENTED;

	/* process and remove the injection radiotap header */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (unlikely(sdata->vif.type == IEEE80211_IF_TYPE_MNTR)) {
		if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
			return TX_DROP;

		/*
		 * __ieee80211_parse_tx_radiotap has now removed
		 * the radiotap header that was present and pre-filled
		 * 'tx' with tx control information.
		 */
	}

	hdr = (struct ieee80211_hdr *) skb->data;

	tx->sta = sta_info_get(local, hdr->addr1);
	tx->fc = le16_to_cpu(hdr->frame_control);

	if (is_multicast_ether_addr(hdr->addr1)) {
		tx->flags &= ~IEEE80211_TX_UNICAST;
		control->flags |= IEEE80211_TXCTL_NO_ACK;
	} else {
		tx->flags |= IEEE80211_TX_UNICAST;
		control->flags &= ~IEEE80211_TXCTL_NO_ACK;
	}

	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		if ((tx->flags & IEEE80211_TX_UNICAST) &&
		    skb->len + FCS_LEN > local->fragmentation_threshold &&
		    !local->ops->set_frag_threshold)
			tx->flags |= IEEE80211_TX_FRAGMENTED;
		else
			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
	}

	if (!tx->sta)
		control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
	else if (tx->sta->flags & WLAN_STA_CLEAR_PS_FILT) {
		control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
		tx->sta->flags &= ~WLAN_STA_CLEAR_PS_FILT;
	}

	hdrlen = ieee80211_get_hdrlen(tx->fc);
	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
	control->flags |= IEEE80211_TXCTL_FIRST_FRAGMENT;

	return TX_CONTINUE;
}

/*
 * NB: @tx is uninitialised when passed in here
 */
static int ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
				struct sk_buff *skb,
				struct net_device *mdev,
				struct ieee80211_tx_control *control)
{
	struct ieee80211_tx_packet_data *pkt_data;
	struct net_device *dev;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	dev = dev_get_by_index(&init_net, pkt_data->ifindex);
	if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
		dev_put(dev);
		dev = NULL;
	}
	if (unlikely(!dev))
		return -ENODEV;
	/* initialises tx with control */
	__ieee80211_tx_prepare(tx, skb, dev, control);
	dev_put(dev);
	return 0;
}

static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
			  struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_control *control = tx->control;
	int ret, i;

	if (!ieee80211_qdisc_installed(local->mdev) &&
	    __ieee80211_queue_stopped(local, 0)) {
		netif_stop_queue(local->mdev);
		return IEEE80211_TX_AGAIN;
	}
	if (skb) {
		ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
				     "TX to low-level driver", skb);
		ret = local->ops->tx(local_to_hw(local), skb, control);
		if (ret)
			return IEEE80211_TX_AGAIN;
		local->mdev->trans_start = jiffies;
		ieee80211_led_tx(local, 1);
	}
	if (tx->extra_frag) {
		control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
				    IEEE80211_TXCTL_USE_CTS_PROTECT |
				    IEEE80211_TXCTL_CLEAR_PS_FILT |
				    IEEE80211_TXCTL_FIRST_FRAGMENT);
		for (i = 0; i < tx->num_extra_frag; i++) {
			if (!tx->extra_frag[i])
				continue;
			if (__ieee80211_queue_stopped(local, control->queue))
				return IEEE80211_TX_FRAG_AGAIN;
			if (i == tx->num_extra_frag) {
				control->tx_rate = tx->last_frag_rate;

				if (tx->flags & IEEE80211_TX_PROBE_LAST_FRAG)
					control->flags |=
						IEEE80211_TXCTL_RATE_CTRL_PROBE;
				else
					control->flags &=
						~IEEE80211_TXCTL_RATE_CTRL_PROBE;
			}

			ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
					     "TX to low-level driver",
					     tx->extra_frag[i]);
			ret = local->ops->tx(local_to_hw(local),
					    tx->extra_frag[i],
					    control);
			if (ret)
				return IEEE80211_TX_FRAG_AGAIN;
			local->mdev->trans_start = jiffies;
			ieee80211_led_tx(local, 1);
			tx->extra_frag[i] = NULL;
		}
		kfree(tx->extra_frag);
		tx->extra_frag = NULL;
	}
	return IEEE80211_TX_OK;
}

static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
			struct ieee80211_tx_control *control)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta;
	ieee80211_tx_handler *handler;
	struct ieee80211_tx_data tx;
	ieee80211_tx_result res = TX_DROP, res_prepare;
	int ret, i;

	WARN_ON(__ieee80211_queue_pending(local, control->queue));

	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
		return 0;
	}

	rcu_read_lock();

	/* initialises tx */
	res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);

	if (res_prepare == TX_DROP) {
		dev_kfree_skb(skb);
		rcu_read_unlock();
		return 0;
	}

	sta = tx.sta;
	tx.channel = local->hw.conf.channel;

	for (handler = ieee80211_tx_handlers; *handler != NULL;
	     handler++) {
		res = (*handler)(&tx);
		if (res != TX_CONTINUE)
			break;
	}

	skb = tx.skb; /* handlers are allowed to change skb */

	if (unlikely(res == TX_DROP)) {
		I802_DEBUG_INC(local->tx_handlers_drop);
		goto drop;
	}

	if (unlikely(res == TX_QUEUED)) {
		I802_DEBUG_INC(local->tx_handlers_queued);
		rcu_read_unlock();
		return 0;
	}

	if (tx.extra_frag) {
		for (i = 0; i < tx.num_extra_frag; i++) {
			int next_len, dur;
			struct ieee80211_hdr *hdr =
				(struct ieee80211_hdr *)
				tx.extra_frag[i]->data;

			if (i + 1 < tx.num_extra_frag) {
				next_len = tx.extra_frag[i + 1]->len;
			} else {
				next_len = 0;
				tx.rate = tx.last_frag_rate;
			}
			dur = ieee80211_duration(&tx, 0, next_len);
			hdr->duration_id = cpu_to_le16(dur);
		}
	}

retry:
	ret = __ieee80211_tx(local, skb, &tx);
	if (ret) {
		struct ieee80211_tx_stored_packet *store =
			&local->pending_packet[control->queue];

		if (ret == IEEE80211_TX_FRAG_AGAIN)
			skb = NULL;
		set_bit(IEEE80211_LINK_STATE_PENDING,
			&local->state[control->queue]);
		smp_mb();
		/* When the driver gets out of buffers during sending of
		 * fragments and calls ieee80211_stop_queue, there is
		 * a small window between IEEE80211_LINK_STATE_XOFF and
		 * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
		 * gets available in that window (i.e. driver calls
		 * ieee80211_wake_queue), we would end up with ieee80211_tx
		 * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
		 * continuing transmitting here when that situation is
		 * possible to have happened. */
		if (!__ieee80211_queue_stopped(local, control->queue)) {
			clear_bit(IEEE80211_LINK_STATE_PENDING,
				  &local->state[control->queue]);
			goto retry;
		}
		memcpy(&store->control, control,
		       sizeof(struct ieee80211_tx_control));
		store->skb = skb;
		store->extra_frag = tx.extra_frag;
		store->num_extra_frag = tx.num_extra_frag;
		store->last_frag_rate = tx.last_frag_rate;
		store->last_frag_rate_ctrl_probe =
			!!(tx.flags & IEEE80211_TX_PROBE_LAST_FRAG);
	}
	rcu_read_unlock();
	return 0;

 drop:
	if (skb)
		dev_kfree_skb(skb);
	for (i = 0; i < tx.num_extra_frag; i++)
		if (tx.extra_frag[i])
			dev_kfree_skb(tx.extra_frag[i]);
	kfree(tx.extra_frag);
	rcu_read_unlock();
	return 0;
}

/* device xmit handlers */

int ieee80211_master_start_xmit(struct sk_buff *skb,
				struct net_device *dev)
{
	struct ieee80211_tx_control control;
	struct ieee80211_tx_packet_data *pkt_data;
	struct net_device *odev = NULL;
	struct ieee80211_sub_if_data *osdata;
	int headroom;
	int ret;

	/*
	 * copy control out of the skb so other people can use skb->cb
	 */
	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(&control, 0, sizeof(struct ieee80211_tx_control));

	if (pkt_data->ifindex)
		odev = dev_get_by_index(&init_net, pkt_data->ifindex);
	if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
		dev_put(odev);
		odev = NULL;
	}
	if (unlikely(!odev)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
		       "originating device\n", dev->name);
#endif
		dev_kfree_skb(skb);
		return 0;
	}
	osdata = IEEE80211_DEV_TO_SUB_IF(odev);

	headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM;
	if (skb_headroom(skb) < headroom) {
		if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
			dev_kfree_skb(skb);
			dev_put(odev);
			return 0;
		}
	}

	control.vif = &osdata->vif;
	control.type = osdata->vif.type;
	if (pkt_data->flags & IEEE80211_TXPD_REQ_TX_STATUS)
		control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
	if (pkt_data->flags & IEEE80211_TXPD_DO_NOT_ENCRYPT)
		control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
	if (pkt_data->flags & IEEE80211_TXPD_REQUEUE)
		control.flags |= IEEE80211_TXCTL_REQUEUE;
	if (pkt_data->flags & IEEE80211_TXPD_EAPOL_FRAME)
		control.flags |= IEEE80211_TXCTL_EAPOL_FRAME;
	if (pkt_data->flags & IEEE80211_TXPD_AMPDU)
		control.flags |= IEEE80211_TXCTL_AMPDU;
	control.queue = pkt_data->queue;

	ret = ieee80211_tx(odev, skb, &control);
	dev_put(odev);

	return ret;
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_tx_packet_data *pkt_data;
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
	u16 len_rthdr;

	/* check for not even having the fixed radiotap header part */
	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
		goto fail; /* too short to be possibly valid */

	/* is it a header version we can trust to find length from? */
	if (unlikely(prthdr->it_version))
		goto fail; /* only version 0 is supported */

	/* then there must be a radiotap header with a length we can use */
	len_rthdr = ieee80211_get_radiotap_len(skb->data);

	/* does the skb contain enough to deliver on the alleged length? */
	if (unlikely(skb->len < len_rthdr))
		goto fail; /* skb too short for claimed rt header extent */

	skb->dev = local->mdev;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(pkt_data, 0, sizeof(*pkt_data));
	/* needed because we set skb device to master */
	pkt_data->ifindex = dev->ifindex;

	pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT;

	/*
	 * fix up the pointers accounting for the radiotap
	 * header still being in there.  We are being given
	 * a precooked IEEE80211 header so no need for
	 * normal processing
	 */
	skb_set_mac_header(skb, len_rthdr);
	/*
	 * these are just fixed to the end of the rt area since we
	 * don't have any better information and at this point, nobody cares
	 */
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);

	/* pass the radiotap header up to the next stage intact */
	dev_queue_xmit(skb);
	return NETDEV_TX_OK;

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
}

/**
 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
 * subinterfaces (wlan#, WDS, and VLAN interfaces)
 * @skb: packet to be sent
 * @dev: incoming interface
 *
 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
 * not be freed, and caller is responsible for either retrying later or freeing
 * skb).
 *
 * This function takes in an Ethernet header and encapsulates it with suitable
 * IEEE 802.11 header based on which interface the packet is coming in. The
 * encapsulated packet will then be passed to master interface, wlan#.11, for
 * transmission (through low-level driver).
 */
int ieee80211_subif_start_xmit(struct sk_buff *skb,
			       struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_tx_packet_data *pkt_data;
	struct ieee80211_sub_if_data *sdata;
	int ret = 1, head_need;
	u16 ethertype, hdrlen,  meshhdrlen = 0, fc;
	struct ieee80211_hdr hdr;
	struct ieee80211s_hdr mesh_hdr;
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
	int nh_pos, h_pos;
	struct sta_info *sta;
	u32 sta_flags = 0;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (unlikely(skb->len < ETH_HLEN)) {
		printk(KERN_DEBUG "%s: short skb (len=%d)\n",
		       dev->name, skb->len);
		ret = 0;
		goto fail;
	}

	nh_pos = skb_network_header(skb) - skb->data;
	h_pos = skb_transport_header(skb) - skb->data;

	/* convert Ethernet header to proper 802.11 header (based on
	 * operation mode) */
	ethertype = (skb->data[12] << 8) | skb->data[13];
	fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;

	switch (sdata->vif.type) {
	case IEEE80211_IF_TYPE_AP:
	case IEEE80211_IF_TYPE_VLAN:
		fc |= IEEE80211_FCTL_FROMDS;
		/* DA BSSID SA */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 24;
		break;
	case IEEE80211_IF_TYPE_WDS:
		fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
		/* RA TA DA SA */
		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 30;
		break;
#ifdef CONFIG_MAC80211_MESH
	case IEEE80211_IF_TYPE_MESH_POINT:
		fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
		/* RA TA DA SA */
		if (is_multicast_ether_addr(skb->data))
			memcpy(hdr.addr1, skb->data, ETH_ALEN);
		else if (mesh_nexthop_lookup(hdr.addr1, skb, dev))
				return 0;
		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
		if (skb->pkt_type == PACKET_OTHERHOST) {
			/* Forwarded frame, keep mesh ttl and seqnum */
			struct ieee80211s_hdr *prev_meshhdr;
			prev_meshhdr = ((struct ieee80211s_hdr *)skb->cb);
			meshhdrlen = ieee80211_get_mesh_hdrlen(prev_meshhdr);
			memcpy(&mesh_hdr, prev_meshhdr, meshhdrlen);
			sdata->u.sta.mshstats.fwded_frames++;
		} else {
			if (!sdata->u.sta.mshcfg.dot11MeshTTL) {
				/* Do not send frames with mesh_ttl == 0 */
				sdata->u.sta.mshstats.dropped_frames_ttl++;
				ret = 0;
				goto fail;
			}
			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
							       sdata);
		}
		hdrlen = 30;
		break;
#endif
	case IEEE80211_IF_TYPE_STA:
		fc |= IEEE80211_FCTL_TODS;
		/* BSSID SA DA */
		memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
		break;
	case IEEE80211_IF_TYPE_IBSS:
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
		hdrlen = 24;
		break;
	default:
		ret = 0;
		goto fail;
	}

	/*
	 * There's no need to try to look up the destination
	 * if it is a multicast address (which can only happen
	 * in AP mode)
	 */
	if (!is_multicast_ether_addr(hdr.addr1)) {
		rcu_read_lock();
		sta = sta_info_get(local, hdr.addr1);
		if (sta)
			sta_flags = sta->flags;
		rcu_read_unlock();
	}

	/* receiver is QoS enabled, use a QoS type frame */
	if (sta_flags & WLAN_STA_WME) {
		fc |= IEEE80211_STYPE_QOS_DATA;
		hdrlen += 2;
	}

	/*
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
	 */
	if (unlikely(!is_multicast_ether_addr(hdr.addr1) &&
		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
		      !(ethertype == ETH_P_PAE &&
		       compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		DECLARE_MAC_BUF(mac);

		if (net_ratelimit())
			printk(KERN_DEBUG "%s: dropped frame to %s"
			       " (unauthorized port)\n", dev->name,
			       print_mac(mac, hdr.addr1));
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

		ret = 0;
		goto fail;
	}

	hdr.frame_control = cpu_to_le16(fc);
	hdr.duration_id = 0;
	hdr.seq_ctrl = 0;

	skip_header_bytes = ETH_HLEN;
	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
		encaps_data = bridge_tunnel_header;
		encaps_len = sizeof(bridge_tunnel_header);
		skip_header_bytes -= 2;
	} else if (ethertype >= 0x600) {
		encaps_data = rfc1042_header;
		encaps_len = sizeof(rfc1042_header);
		skip_header_bytes -= 2;
	} else {
		encaps_data = NULL;
		encaps_len = 0;
	}

	skb_pull(skb, skip_header_bytes);
	nh_pos -= skip_header_bytes;
	h_pos -= skip_header_bytes;

	/* TODO: implement support for fragments so that there is no need to
	 * reallocate and copy payload; it might be enough to support one
	 * extra fragment that would be copied in the beginning of the frame
	 * data.. anyway, it would be nice to include this into skb structure
	 * somehow
	 *
	 * There are few options for this:
	 * use skb->cb as an extra space for 802.11 header
	 * allocate new buffer if not enough headroom
	 * make sure that there is enough headroom in every skb by increasing
	 * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
	 * alloc_skb() (net/core/skbuff.c)
	 */
	head_need = hdrlen + encaps_len + meshhdrlen + local->tx_headroom;
	head_need -= skb_headroom(skb);

	/* We are going to modify skb data, so make a copy of it if happens to
	 * be cloned. This could happen, e.g., with Linux bridge code passing
	 * us broadcast frames. */

	if (head_need > 0 || skb_header_cloned(skb)) {
#if 0
		printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
		       "of headroom\n", dev->name, head_need);
#endif

		if (skb_header_cloned(skb))
			I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
		else
			I802_DEBUG_INC(local->tx_expand_skb_head);
		/* Since we have to reallocate the buffer, make sure that there
		 * is enough room for possible WEP IV/ICV and TKIP (8 bytes
		 * before payload and 12 after). */
		if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
				     12, GFP_ATOMIC)) {
			printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
			       "\n", dev->name);
			goto fail;
		}
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}

	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}

	if (fc & IEEE80211_STYPE_QOS_DATA) {
		__le16 *qos_control;

		qos_control = (__le16*) skb_push(skb, 2);
		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
		/*
		 * Maybe we could actually set some fields here, for now just
		 * initialise to zero to indicate no special operation.
		 */
		*qos_control = 0;
	} else
		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);

	nh_pos += hdrlen;
	h_pos += hdrlen;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
	pkt_data->ifindex = dev->ifindex;
	if (ethertype == ETH_P_PAE)
		pkt_data->flags |= IEEE80211_TXPD_EAPOL_FRAME;

	skb->dev = local->mdev;
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	/* Update skb pointers to various headers since this modified frame
	 * is going to go through Linux networking code that may potentially
	 * need things like pointer to IP header. */
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, nh_pos);
	skb_set_transport_header(skb, h_pos);

	dev->trans_start = jiffies;
	dev_queue_xmit(skb);

	return 0;

 fail:
	if (!ret)
		dev_kfree_skb(skb);

	return ret;
}

/* helper functions for pending packets for when queues are stopped */

void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
	int i, j;
	struct ieee80211_tx_stored_packet *store;

	for (i = 0; i < local->hw.queues; i++) {
		if (!__ieee80211_queue_pending(local, i))
			continue;
		store = &local->pending_packet[i];
		kfree_skb(store->skb);
		for (j = 0; j < store->num_extra_frag; j++)
			kfree_skb(store->extra_frag[j]);
		kfree(store->extra_frag);
		clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
	}
}

void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
	struct net_device *dev = local->mdev;
	struct ieee80211_tx_stored_packet *store;
	struct ieee80211_tx_data tx;
	int i, ret, reschedule = 0;

	netif_tx_lock_bh(dev);
	for (i = 0; i < local->hw.queues; i++) {
		if (__ieee80211_queue_stopped(local, i))
			continue;
		if (!__ieee80211_queue_pending(local, i)) {
			reschedule = 1;
			continue;
		}
		store = &local->pending_packet[i];
		tx.control = &store->control;
		tx.extra_frag = store->extra_frag;
		tx.num_extra_frag = store->num_extra_frag;
		tx.last_frag_rate = store->last_frag_rate;
		tx.flags = 0;
		if (store->last_frag_rate_ctrl_probe)
			tx.flags |= IEEE80211_TX_PROBE_LAST_FRAG;
		ret = __ieee80211_tx(local, store->skb, &tx);
		if (ret) {
			if (ret == IEEE80211_TX_FRAG_AGAIN)
				store->skb = NULL;
		} else {
			clear_bit(IEEE80211_LINK_STATE_PENDING,
				  &local->state[i]);
			reschedule = 1;
		}
	}
	netif_tx_unlock_bh(dev);
	if (reschedule) {
		if (!ieee80211_qdisc_installed(dev)) {
			if (!__ieee80211_queue_stopped(local, 0))
				netif_wake_queue(dev);
		} else
			netif_schedule(dev);
	}
}

/* functions for drivers to get certain frames */

static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
				     struct ieee80211_if_ap *bss,
				     struct sk_buff *skb,
				     struct beacon_data *beacon)
{
	u8 *pos, *tim;
	int aid0 = 0;
	int i, have_bits = 0, n1, n2;

	/* Generate bitmap for TIM only if there are any STAs in power save
	 * mode. */
	if (atomic_read(&bss->num_sta_ps) > 0)
		/* in the hope that this is faster than
		 * checking byte-for-byte */
		have_bits = !bitmap_empty((unsigned long*)bss->tim,
					  IEEE80211_MAX_AID+1);

	if (bss->dtim_count == 0)
		bss->dtim_count = beacon->dtim_period - 1;
	else
		bss->dtim_count--;

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = bss->dtim_count;
	*pos++ = beacon->dtim_period;

	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
		aid0 = 1;

	if (have_bits) {
		/* Find largest even number N1 so that bits numbered 1 through
		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
		 * (N2 + 1) x 8 through 2007 are 0. */
		n1 = 0;
		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
			if (bss->tim[i]) {
				n1 = i & 0xfe;
				break;
			}
		}
		n2 = n1;
		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
			if (bss->tim[i]) {
				n2 = i;
				break;
			}
		}

		/* Bitmap control */
		*pos++ = n1 | aid0;
		/* Part Virt Bitmap */
		memcpy(pos, bss->tim + n1, n2 - n1 + 1);

		tim[1] = n2 - n1 + 4;
		skb_put(skb, n2 - n1);
	} else {
		*pos++ = aid0; /* Bitmap control */
		*pos++ = 0; /* Part Virt Bitmap */
	}
}

struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
				     struct ieee80211_vif *vif,
				     struct ieee80211_tx_control *control)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sk_buff *skb;
	struct net_device *bdev;
	struct ieee80211_sub_if_data *sdata = NULL;
	struct ieee80211_if_ap *ap = NULL;
	struct rate_selection rsel;
	struct beacon_data *beacon;
	struct ieee80211_supported_band *sband;
	struct ieee80211_mgmt *mgmt;
	int *num_beacons;
	bool err = true;
	u8 *pos;

	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	rcu_read_lock();

	sdata = vif_to_sdata(vif);
	bdev = sdata->dev;

	if (sdata->vif.type == IEEE80211_IF_TYPE_AP) {
		ap = &sdata->u.ap;
		beacon = rcu_dereference(ap->beacon);
		if (ap && beacon) {
			/*
			 * headroom, head length,
			 * tail length and maximum TIM length
			 */
			skb = dev_alloc_skb(local->tx_headroom +
					    beacon->head_len +
					    beacon->tail_len + 256);
			if (!skb)
				goto out;

			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);

			ieee80211_include_sequence(sdata,
					(struct ieee80211_hdr *)skb->data);

			/*
			 * Not very nice, but we want to allow the driver to call
			 * ieee80211_beacon_get() as a response to the set_tim()
			 * callback. That, however, is already invoked under the
			 * sta_lock to guarantee consistent and race-free update
			 * of the tim bitmap in mac80211 and the driver.
			 */
			if (local->tim_in_locked_section) {
				ieee80211_beacon_add_tim(local, ap, skb, beacon);
			} else {
				unsigned long flags;

				spin_lock_irqsave(&local->sta_lock, flags);
				ieee80211_beacon_add_tim(local, ap, skb, beacon);
				spin_unlock_irqrestore(&local->sta_lock, flags);
			}

			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);

			num_beacons = &ap->num_beacons;

			err = false;
		}
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
		/* headroom, head length, tail length and maximum TIM length */
		skb = dev_alloc_skb(local->tx_headroom + 400);
		if (!skb)
			goto out;

		skb_reserve(skb, local->hw.extra_tx_headroom);
		mgmt = (struct ieee80211_mgmt *)
			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
		mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
						   IEEE80211_STYPE_BEACON);
		memset(mgmt->da, 0xff, ETH_ALEN);
		memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
		/* BSSID is left zeroed, wildcard value */
		mgmt->u.beacon.beacon_int =
			cpu_to_le16(local->hw.conf.beacon_int);
		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */

		pos = skb_put(skb, 2);
		*pos++ = WLAN_EID_SSID;
		*pos++ = 0x0;

		mesh_mgmt_ies_add(skb, sdata->dev);

		num_beacons = &sdata->u.sta.num_beacons;

		err = false;
	}

	if (err) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "no beacon data avail for %s\n",
			       bdev->name);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
		skb = NULL;
		goto out;
	}

	if (control) {
		rate_control_get_rate(local->mdev, sband, skb, &rsel);
		if (!rsel.rate) {
			if (net_ratelimit()) {
				printk(KERN_DEBUG "%s: ieee80211_beacon_get: "
				       "no rate found\n",
				       wiphy_name(local->hw.wiphy));
			}
			dev_kfree_skb(skb);
			skb = NULL;
			goto out;
		}

		control->vif = vif;
		control->tx_rate = rsel.rate;
		if (sdata->bss_conf.use_short_preamble &&
		    rsel.rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
			control->flags |= IEEE80211_TXCTL_SHORT_PREAMBLE;
		control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
		control->flags |= IEEE80211_TXCTL_NO_ACK;
		control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
		control->retry_limit = 1;
		control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
	}
	(*num_beacons)++;
out:
	rcu_read_unlock();
	return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
		       const void *frame, size_t frame_len,
		       const struct ieee80211_tx_control *frame_txctl,
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;
	u16 fctl;

	fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
	rts->frame_control = cpu_to_le16(fctl);
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
			     const void *frame, size_t frame_len,
			     const struct ieee80211_tx_control *frame_txctl,
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;
	u16 fctl;

	fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
	cts->frame_control = cpu_to_le16(fctl);
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
			  struct ieee80211_vif *vif,
			  struct ieee80211_tx_control *control)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sk_buff *skb;
	struct sta_info *sta;
	ieee80211_tx_handler *handler;
	struct ieee80211_tx_data tx;
	ieee80211_tx_result res = TX_DROP;
	struct net_device *bdev;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_ap *bss = NULL;
	struct beacon_data *beacon;

	sdata = vif_to_sdata(vif);
	bdev = sdata->dev;


	if (!bss)
		return NULL;

	rcu_read_lock();
	beacon = rcu_dereference(bss->beacon);

	if (sdata->vif.type != IEEE80211_IF_TYPE_AP || !beacon ||
	    !beacon->head) {
		rcu_read_unlock();
		return NULL;
	}

	if (bss->dtim_count != 0)
		return NULL; /* send buffered bc/mc only after DTIM beacon */
	memset(control, 0, sizeof(*control));
	while (1) {
		skb = skb_dequeue(&bss->ps_bc_buf);
		if (!skb)
			return NULL;
		local->total_ps_buffered--;

		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
			struct ieee80211_hdr *hdr =
				(struct ieee80211_hdr *) skb->data;
			/* more buffered multicast/broadcast frames ==> set
			 * MoreData flag in IEEE 802.11 header to inform PS
			 * STAs */
			hdr->frame_control |=
				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
		}

		if (!ieee80211_tx_prepare(&tx, skb, local->mdev, control))
			break;
		dev_kfree_skb_any(skb);
	}
	sta = tx.sta;
	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	tx.channel = local->hw.conf.channel;

	for (handler = ieee80211_tx_handlers; *handler != NULL; handler++) {
		res = (*handler)(&tx);
		if (res == TX_DROP || res == TX_QUEUED)
			break;
	}
	skb = tx.skb; /* handlers are allowed to change skb */

	if (res == TX_DROP) {
		I802_DEBUG_INC(local->tx_handlers_drop);
		dev_kfree_skb(skb);
		skb = NULL;
	} else if (res == TX_QUEUED) {
		I802_DEBUG_INC(local->tx_handlers_queued);
		skb = NULL;
	}

	rcu_read_unlock();

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);