summaryrefslogtreecommitdiffstats
path: root/net/wireless/reg.c
blob: baf5704740ee62080e8dc4a16de8cb71503b7669 (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
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2008-2011	Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */


/**
 * DOC: Wireless regulatory infrastructure
 *
 * The usual implementation is for a driver to read a device EEPROM to
 * determine which regulatory domain it should be operating under, then
 * looking up the allowable channels in a driver-local table and finally
 * registering those channels in the wiphy structure.
 *
 * Another set of compliance enforcement is for drivers to use their
 * own compliance limits which can be stored on the EEPROM. The host
 * driver or firmware may ensure these are used.
 *
 * In addition to all this we provide an extra layer of regulatory
 * conformance. For drivers which do not have any regulatory
 * information CRDA provides the complete regulatory solution.
 * For others it provides a community effort on further restrictions
 * to enhance compliance.
 *
 * Note: When number of rules --> infinity we will not be able to
 * index on alpha2 any more, instead we'll probably have to
 * rely on some SHA1 checksum of the regdomain for example.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/ctype.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <linux/moduleparam.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"
#include "regdb.h"
#include "nl80211.h"

#ifdef CONFIG_CFG80211_REG_DEBUG
#define REG_DBG_PRINT(format, args...)			\
	printk(KERN_DEBUG pr_fmt(format), ##args)
#else
#define REG_DBG_PRINT(args...)
#endif

static struct regulatory_request core_request_world = {
	.initiator = NL80211_REGDOM_SET_BY_CORE,
	.alpha2[0] = '0',
	.alpha2[1] = '0',
	.intersect = false,
	.processed = true,
	.country_ie_env = ENVIRON_ANY,
};

/* Receipt of information from last regulatory request */
static struct regulatory_request *last_request = &core_request_world;

/* To trigger userspace events */
static struct platform_device *reg_pdev;

static struct device_type reg_device_type = {
	.uevent = reg_device_uevent,
};

/*
 * Central wireless core regulatory domains, we only need two,
 * the current one and a world regulatory domain in case we have no
 * information to give us an alpha2
 */
const struct ieee80211_regdomain *cfg80211_regdomain;

/*
 * Protects static reg.c components:
 *     - cfg80211_world_regdom
 *     - cfg80211_regdom
 *     - last_request
 */
static DEFINE_MUTEX(reg_mutex);

static inline void assert_reg_lock(void)
{
	lockdep_assert_held(&reg_mutex);
}

/* Used to queue up regulatory hints */
static LIST_HEAD(reg_requests_list);
static spinlock_t reg_requests_lock;

/* Used to queue up beacon hints for review */
static LIST_HEAD(reg_pending_beacons);
static spinlock_t reg_pending_beacons_lock;

/* Used to keep track of processed beacon hints */
static LIST_HEAD(reg_beacon_list);

struct reg_beacon {
	struct list_head list;
	struct ieee80211_channel chan;
};

static void reg_todo(struct work_struct *work);
static DECLARE_WORK(reg_work, reg_todo);

static void reg_timeout_work(struct work_struct *work);
static DECLARE_DELAYED_WORK(reg_timeout, reg_timeout_work);

/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
	.n_reg_rules = 5,
	.alpha2 =  "00",
	.reg_rules = {
		/* IEEE 802.11b/g, channels 1..11 */
		REG_RULE(2412-10, 2462+10, 40, 6, 20, 0),
		/* IEEE 802.11b/g, channels 12..13. No HT40
		 * channel fits here. */
		REG_RULE(2467-10, 2472+10, 20, 6, 20,
			NL80211_RRF_PASSIVE_SCAN |
			NL80211_RRF_NO_IBSS),
		/* IEEE 802.11 channel 14 - Only JP enables
		 * this and for 802.11b only */
		REG_RULE(2484-10, 2484+10, 20, 6, 20,
			NL80211_RRF_PASSIVE_SCAN |
			NL80211_RRF_NO_IBSS |
			NL80211_RRF_NO_OFDM),
		/* IEEE 802.11a, channel 36..48 */
		REG_RULE(5180-10, 5240+10, 40, 6, 20,
                        NL80211_RRF_PASSIVE_SCAN |
                        NL80211_RRF_NO_IBSS),

		/* NB: 5260 MHz - 5700 MHz requies DFS */

		/* IEEE 802.11a, channel 149..165 */
		REG_RULE(5745-10, 5825+10, 40, 6, 20,
			NL80211_RRF_PASSIVE_SCAN |
			NL80211_RRF_NO_IBSS),
	}
};

static const struct ieee80211_regdomain *cfg80211_world_regdom =
	&world_regdom;

static char *ieee80211_regdom = "00";
static char user_alpha2[2];

module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");

static void reset_regdomains(bool full_reset)
{
	/* avoid freeing static information or freeing something twice */
	if (cfg80211_regdomain == cfg80211_world_regdom)
		cfg80211_regdomain = NULL;
	if (cfg80211_world_regdom == &world_regdom)
		cfg80211_world_regdom = NULL;
	if (cfg80211_regdomain == &world_regdom)
		cfg80211_regdomain = NULL;

	kfree(cfg80211_regdomain);
	kfree(cfg80211_world_regdom);

	cfg80211_world_regdom = &world_regdom;
	cfg80211_regdomain = NULL;

	if (!full_reset)
		return;

	if (last_request != &core_request_world)
		kfree(last_request);
	last_request = &core_request_world;
}

/*
 * Dynamic world regulatory domain requested by the wireless
 * core upon initialization
 */
static void update_world_regdomain(const struct ieee80211_regdomain *rd)
{
	BUG_ON(!last_request);

	reset_regdomains(false);

	cfg80211_world_regdom = rd;
	cfg80211_regdomain = rd;
}

bool is_world_regdom(const char *alpha2)
{
	if (!alpha2)
		return false;
	if (alpha2[0] == '0' && alpha2[1] == '0')
		return true;
	return false;
}

static bool is_alpha2_set(const char *alpha2)
{
	if (!alpha2)
		return false;
	if (alpha2[0] != 0 && alpha2[1] != 0)
		return true;
	return false;
}

static bool is_unknown_alpha2(const char *alpha2)
{
	if (!alpha2)
		return false;
	/*
	 * Special case where regulatory domain was built by driver
	 * but a specific alpha2 cannot be determined
	 */
	if (alpha2[0] == '9' && alpha2[1] == '9')
		return true;
	return false;
}

static bool is_intersected_alpha2(const char *alpha2)
{
	if (!alpha2)
		return false;
	/*
	 * Special case where regulatory domain is the
	 * result of an intersection between two regulatory domain
	 * structures
	 */
	if (alpha2[0] == '9' && alpha2[1] == '8')
		return true;
	return false;
}

static bool is_an_alpha2(const char *alpha2)
{
	if (!alpha2)
		return false;
	if (isalpha(alpha2[0]) && isalpha(alpha2[1]))
		return true;
	return false;
}

static bool alpha2_equal(const char *alpha2_x, const char *alpha2_y)
{
	if (!alpha2_x || !alpha2_y)
		return false;
	if (alpha2_x[0] == alpha2_y[0] &&
		alpha2_x[1] == alpha2_y[1])
		return true;
	return false;
}

static bool regdom_changes(const char *alpha2)
{
	assert_cfg80211_lock();

	if (!cfg80211_regdomain)
		return true;
	if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
		return false;
	return true;
}

/*
 * The NL80211_REGDOM_SET_BY_USER regdom alpha2 is cached, this lets
 * you know if a valid regulatory hint with NL80211_REGDOM_SET_BY_USER
 * has ever been issued.
 */
static bool is_user_regdom_saved(void)
{
	if (user_alpha2[0] == '9' && user_alpha2[1] == '7')
		return false;

	/* This would indicate a mistake on the design */
	if (WARN((!is_world_regdom(user_alpha2) &&
		  !is_an_alpha2(user_alpha2)),
		 "Unexpected user alpha2: %c%c\n",
		 user_alpha2[0],
	         user_alpha2[1]))
		return false;

	return true;
}

static int reg_copy_regd(const struct ieee80211_regdomain **dst_regd,
			 const struct ieee80211_regdomain *src_regd)
{
	struct ieee80211_regdomain *regd;
	int size_of_regd = 0;
	unsigned int i;

	size_of_regd = sizeof(struct ieee80211_regdomain) +
	  ((src_regd->n_reg_rules + 1) * sizeof(struct ieee80211_reg_rule));

	regd = kzalloc(size_of_regd, GFP_KERNEL);
	if (!regd)
		return -ENOMEM;

	memcpy(regd, src_regd, sizeof(struct ieee80211_regdomain));

	for (i = 0; i < src_regd->n_reg_rules; i++)
		memcpy(&regd->reg_rules[i], &src_regd->reg_rules[i],
			sizeof(struct ieee80211_reg_rule));

	*dst_regd = regd;
	return 0;
}

#ifdef CONFIG_CFG80211_INTERNAL_REGDB
struct reg_regdb_search_request {
	char alpha2[2];
	struct list_head list;
};

static LIST_HEAD(reg_regdb_search_list);
static DEFINE_MUTEX(reg_regdb_search_mutex);

static void reg_regdb_search(struct work_struct *work)
{
	struct reg_regdb_search_request *request;
	const struct ieee80211_regdomain *curdom, *regdom;
	int i, r;

	mutex_lock(&reg_regdb_search_mutex);
	while (!list_empty(&reg_regdb_search_list)) {
		request = list_first_entry(&reg_regdb_search_list,
					   struct reg_regdb_search_request,
					   list);
		list_del(&request->list);

		for (i=0; i<reg_regdb_size; i++) {
			curdom = reg_regdb[i];

			if (!memcmp(request->alpha2, curdom->alpha2, 2)) {
				r = reg_copy_regd(&regdom, curdom);
				if (r)
					break;
				mutex_lock(&cfg80211_mutex);
				set_regdom(regdom);
				mutex_unlock(&cfg80211_mutex);
				break;
			}
		}

		kfree(request);
	}
	mutex_unlock(&reg_regdb_search_mutex);
}

static DECLARE_WORK(reg_regdb_work, reg_regdb_search);

static void reg_regdb_query(const char *alpha2)
{
	struct reg_regdb_search_request *request;

	if (!alpha2)
		return;

	request = kzalloc(sizeof(struct reg_regdb_search_request), GFP_KERNEL);
	if (!request)
		return;

	memcpy(request->alpha2, alpha2, 2);

	mutex_lock(&reg_regdb_search_mutex);
	list_add_tail(&request->list, &reg_regdb_search_list);
	mutex_unlock(&reg_regdb_search_mutex);

	schedule_work(&reg_regdb_work);
}

/* Feel free to add any other sanity checks here */
static void reg_regdb_size_check(void)
{
	/* We should ideally BUILD_BUG_ON() but then random builds would fail */
	WARN_ONCE(!reg_regdb_size, "db.txt is empty, you should update it...");
}
#else
static inline void reg_regdb_size_check(void) {}
static inline void reg_regdb_query(const char *alpha2) {}
#endif /* CONFIG_CFG80211_INTERNAL_REGDB */

/*
 * This lets us keep regulatory code which is updated on a regulatory
 * basis in userspace. Country information is filled in by
 * reg_device_uevent
 */
static int call_crda(const char *alpha2)
{
	if (!is_world_regdom((char *) alpha2))
		pr_info("Calling CRDA for country: %c%c\n",
			alpha2[0], alpha2[1]);
	else
		pr_info("Calling CRDA to update world regulatory domain\n");

	/* query internal regulatory database (if it exists) */
	reg_regdb_query(alpha2);

	return kobject_uevent(&reg_pdev->dev.kobj, KOBJ_CHANGE);
}

/* Used by nl80211 before kmalloc'ing our regulatory domain */
bool reg_is_valid_request(const char *alpha2)
{
	assert_cfg80211_lock();

	if (!last_request)
		return false;

	return alpha2_equal(last_request->alpha2, alpha2);
}

/* Sanity check on a regulatory rule */
static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
{
	const struct ieee80211_freq_range *freq_range = &rule->freq_range;
	u32 freq_diff;

	if (freq_range->start_freq_khz <= 0 || freq_range->end_freq_khz <= 0)
		return false;

	if (freq_range->start_freq_khz > freq_range->end_freq_khz)
		return false;

	freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;

	if (freq_range->end_freq_khz <= freq_range->start_freq_khz ||
			freq_range->max_bandwidth_khz > freq_diff)
		return false;

	return true;
}

static bool is_valid_rd(const struct ieee80211_regdomain *rd)
{
	const struct ieee80211_reg_rule *reg_rule = NULL;
	unsigned int i;

	if (!rd->n_reg_rules)
		return false;

	if (WARN_ON(rd->n_reg_rules > NL80211_MAX_SUPP_REG_RULES))
		return false;

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		if (!is_valid_reg_rule(reg_rule))
			return false;
	}

	return true;
}

static bool reg_does_bw_fit(const struct ieee80211_freq_range *freq_range,
			    u32 center_freq_khz,
			    u32 bw_khz)
{
	u32 start_freq_khz, end_freq_khz;

	start_freq_khz = center_freq_khz - (bw_khz/2);
	end_freq_khz = center_freq_khz + (bw_khz/2);

	if (start_freq_khz >= freq_range->start_freq_khz &&
	    end_freq_khz <= freq_range->end_freq_khz)
		return true;

	return false;
}

/**
 * freq_in_rule_band - tells us if a frequency is in a frequency band
 * @freq_range: frequency rule we want to query
 * @freq_khz: frequency we are inquiring about
 *
 * This lets us know if a specific frequency rule is or is not relevant to
 * a specific frequency's band. Bands are device specific and artificial
 * definitions (the "2.4 GHz band" and the "5 GHz band"), however it is
 * safe for now to assume that a frequency rule should not be part of a
 * frequency's band if the start freq or end freq are off by more than 2 GHz.
 * This resolution can be lowered and should be considered as we add
 * regulatory rule support for other "bands".
 **/
static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
	u32 freq_khz)
{
#define ONE_GHZ_IN_KHZ	1000000
	if (abs(freq_khz - freq_range->start_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
		return true;
	if (abs(freq_khz - freq_range->end_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
		return true;
	return false;
#undef ONE_GHZ_IN_KHZ
}

/*
 * Helper for regdom_intersect(), this does the real
 * mathematical intersection fun
 */
static int reg_rules_intersect(
	const struct ieee80211_reg_rule *rule1,
	const struct ieee80211_reg_rule *rule2,
	struct ieee80211_reg_rule *intersected_rule)
{
	const struct ieee80211_freq_range *freq_range1, *freq_range2;
	struct ieee80211_freq_range *freq_range;
	const struct ieee80211_power_rule *power_rule1, *power_rule2;
	struct ieee80211_power_rule *power_rule;
	u32 freq_diff;

	freq_range1 = &rule1->freq_range;
	freq_range2 = &rule2->freq_range;
	freq_range = &intersected_rule->freq_range;

	power_rule1 = &rule1->power_rule;
	power_rule2 = &rule2->power_rule;
	power_rule = &intersected_rule->power_rule;

	freq_range->start_freq_khz = max(freq_range1->start_freq_khz,
		freq_range2->start_freq_khz);
	freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
		freq_range2->end_freq_khz);
	freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz,
		freq_range2->max_bandwidth_khz);

	freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
	if (freq_range->max_bandwidth_khz > freq_diff)
		freq_range->max_bandwidth_khz = freq_diff;

	power_rule->max_eirp = min(power_rule1->max_eirp,
		power_rule2->max_eirp);
	power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain,
		power_rule2->max_antenna_gain);

	intersected_rule->flags = (rule1->flags | rule2->flags);

	if (!is_valid_reg_rule(intersected_rule))
		return -EINVAL;

	return 0;
}

/**
 * regdom_intersect - do the intersection between two regulatory domains
 * @rd1: first regulatory domain
 * @rd2: second regulatory domain
 *
 * Use this function to get the intersection between two regulatory domains.
 * Once completed we will mark the alpha2 for the rd as intersected, "98",
 * as no one single alpha2 can represent this regulatory domain.
 *
 * Returns a pointer to the regulatory domain structure which will hold the
 * resulting intersection of rules between rd1 and rd2. We will
 * kzalloc() this structure for you.
 */
static struct ieee80211_regdomain *regdom_intersect(
	const struct ieee80211_regdomain *rd1,
	const struct ieee80211_regdomain *rd2)
{
	int r, size_of_regd;
	unsigned int x, y;
	unsigned int num_rules = 0, rule_idx = 0;
	const struct ieee80211_reg_rule *rule1, *rule2;
	struct ieee80211_reg_rule *intersected_rule;
	struct ieee80211_regdomain *rd;
	/* This is just a dummy holder to help us count */
	struct ieee80211_reg_rule irule;

	/* Uses the stack temporarily for counter arithmetic */
	intersected_rule = &irule;

	memset(intersected_rule, 0, sizeof(struct ieee80211_reg_rule));

	if (!rd1 || !rd2)
		return NULL;

	/*
	 * First we get a count of the rules we'll need, then we actually
	 * build them. This is to so we can malloc() and free() a
	 * regdomain once. The reason we use reg_rules_intersect() here
	 * is it will return -EINVAL if the rule computed makes no sense.
	 * All rules that do check out OK are valid.
	 */

	for (x = 0; x < rd1->n_reg_rules; x++) {
		rule1 = &rd1->reg_rules[x];
		for (y = 0; y < rd2->n_reg_rules; y++) {
			rule2 = &rd2->reg_rules[y];
			if (!reg_rules_intersect(rule1, rule2,
					intersected_rule))
				num_rules++;
			memset(intersected_rule, 0,
					sizeof(struct ieee80211_reg_rule));
		}
	}

	if (!num_rules)
		return NULL;

	size_of_regd = sizeof(struct ieee80211_regdomain) +
		((num_rules + 1) * sizeof(struct ieee80211_reg_rule));

	rd = kzalloc(size_of_regd, GFP_KERNEL);
	if (!rd)
		return NULL;

	for (x = 0; x < rd1->n_reg_rules; x++) {
		rule1 = &rd1->reg_rules[x];
		for (y = 0; y < rd2->n_reg_rules; y++) {
			rule2 = &rd2->reg_rules[y];
			/*
			 * This time around instead of using the stack lets
			 * write to the target rule directly saving ourselves
			 * a memcpy()
			 */
			intersected_rule = &rd->reg_rules[rule_idx];
			r = reg_rules_intersect(rule1, rule2,
				intersected_rule);
			/*
			 * No need to memset here the intersected rule here as
			 * we're not using the stack anymore
			 */
			if (r)
				continue;
			rule_idx++;
		}
	}

	if (rule_idx != num_rules) {
		kfree(rd);
		return NULL;
	}

	rd->n_reg_rules = num_rules;
	rd->alpha2[0] = '9';
	rd->alpha2[1] = '8';

	return rd;
}

/*
 * XXX: add support for the rest of enum nl80211_reg_rule_flags, we may
 * want to just have the channel structure use these
 */
static u32 map_regdom_flags(u32 rd_flags)
{
	u32 channel_flags = 0;
	if (rd_flags & NL80211_RRF_PASSIVE_SCAN)
		channel_flags |= IEEE80211_CHAN_PASSIVE_SCAN;
	if (rd_flags & NL80211_RRF_NO_IBSS)
		channel_flags |= IEEE80211_CHAN_NO_IBSS;
	if (rd_flags & NL80211_RRF_DFS)
		channel_flags |= IEEE80211_CHAN_RADAR;
	return channel_flags;
}

static int freq_reg_info_regd(struct wiphy *wiphy,
			      u32 center_freq,
			      u32 desired_bw_khz,
			      const struct ieee80211_reg_rule **reg_rule,
			      const struct ieee80211_regdomain *custom_regd)
{
	int i;
	bool band_rule_found = false;
	const struct ieee80211_regdomain *regd;
	bool bw_fits = false;

	if (!desired_bw_khz)
		desired_bw_khz = MHZ_TO_KHZ(20);

	regd = custom_regd ? custom_regd : cfg80211_regdomain;

	/*
	 * Follow the driver's regulatory domain, if present, unless a country
	 * IE has been processed or a user wants to help complaince further
	 */
	if (!custom_regd &&
	    last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
	    last_request->initiator != NL80211_REGDOM_SET_BY_USER &&
	    wiphy->regd)
		regd = wiphy->regd;

	if (!regd)
		return -EINVAL;

	for (i = 0; i < regd->n_reg_rules; i++) {
		const struct ieee80211_reg_rule *rr;
		const struct ieee80211_freq_range *fr = NULL;

		rr = &regd->reg_rules[i];
		fr = &rr->freq_range;

		/*
		 * We only need to know if one frequency rule was
		 * was in center_freq's band, that's enough, so lets
		 * not overwrite it once found
		 */
		if (!band_rule_found)
			band_rule_found = freq_in_rule_band(fr, center_freq);

		bw_fits = reg_does_bw_fit(fr,
					  center_freq,
					  desired_bw_khz);

		if (band_rule_found && bw_fits) {
			*reg_rule = rr;
			return 0;
		}
	}

	if (!band_rule_found)
		return -ERANGE;

	return -EINVAL;
}

int freq_reg_info(struct wiphy *wiphy,
		  u32 center_freq,
		  u32 desired_bw_khz,
		  const struct ieee80211_reg_rule **reg_rule)
{
	assert_cfg80211_lock();
	return freq_reg_info_regd(wiphy,
				  center_freq,
				  desired_bw_khz,
				  reg_rule,
				  NULL);
}
EXPORT_SYMBOL(freq_reg_info);

#ifdef CONFIG_CFG80211_REG_DEBUG
static const char *reg_initiator_name(enum nl80211_reg_initiator initiator)
{
	switch (initiator) {
	case NL80211_REGDOM_SET_BY_CORE:
		return "Set by core";
	case NL80211_REGDOM_SET_BY_USER:
		return "Set by user";
	case NL80211_REGDOM_SET_BY_DRIVER:
		return "Set by driver";
	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
		return "Set by country IE";
	default:
		WARN_ON(1);
		return "Set by bug";
	}
}

static void chan_reg_rule_print_dbg(struct ieee80211_channel *chan,
				    u32 desired_bw_khz,
				    const struct ieee80211_reg_rule *reg_rule)
{
	const struct ieee80211_power_rule *power_rule;
	const struct ieee80211_freq_range *freq_range;
	char max_antenna_gain[32];

	power_rule = &reg_rule->power_rule;
	freq_range = &reg_rule->freq_range;

	if (!power_rule->max_antenna_gain)
		snprintf(max_antenna_gain, 32, "N/A");
	else
		snprintf(max_antenna_gain, 32, "%d", power_rule->max_antenna_gain);

	REG_DBG_PRINT("Updating information on frequency %d MHz "
		      "for a %d MHz width channel with regulatory rule:\n",
		      chan->center_freq,
		      KHZ_TO_MHZ(desired_bw_khz));

	REG_DBG_PRINT("%d KHz - %d KHz @ %d KHz), (%s mBi, %d mBm)\n",
		      freq_range->start_freq_khz,
		      freq_range->end_freq_khz,
		      freq_range->max_bandwidth_khz,
		      max_antenna_gain,
		      power_rule->max_eirp);
}
#else
static void chan_reg_rule_print_dbg(struct ieee80211_channel *chan,
				    u32 desired_bw_khz,
				    const struct ieee80211_reg_rule *reg_rule)
{
	return;
}
#endif

/*
 * Note that right now we assume the desired channel bandwidth
 * is always 20 MHz for each individual channel (HT40 uses 20 MHz
 * per channel, the primary and the extension channel). To support
 * smaller custom bandwidths such as 5 MHz or 10 MHz we'll need a
 * new ieee80211_channel.target_bw and re run the regulatory check
 * on the wiphy with the target_bw specified. Then we can simply use
 * that below for the desired_bw_khz below.
 */
static void handle_channel(struct wiphy *wiphy,
			   enum nl80211_reg_initiator initiator,
			   enum ieee80211_band band,
			   unsigned int chan_idx)
{
	int r;
	u32 flags, bw_flags = 0;
	u32 desired_bw_khz = MHZ_TO_KHZ(20);
	const struct ieee80211_reg_rule *reg_rule = NULL;
	const struct ieee80211_power_rule *power_rule = NULL;
	const struct ieee80211_freq_range *freq_range = NULL;
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *chan;
	struct wiphy *request_wiphy = NULL;

	assert_cfg80211_lock();

	request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

	sband = wiphy->bands[band];
	BUG_ON(chan_idx >= sband->n_channels);
	chan = &sband->channels[chan_idx];

	flags = chan->orig_flags;

	r = freq_reg_info(wiphy,
			  MHZ_TO_KHZ(chan->center_freq),
			  desired_bw_khz,
			  &reg_rule);

	if (r) {
		/*
		 * We will disable all channels that do not match our
		 * received regulatory rule unless the hint is coming
		 * from a Country IE and the Country IE had no information
		 * about a band. The IEEE 802.11 spec allows for an AP
		 * to send only a subset of the regulatory rules allowed,
		 * so an AP in the US that only supports 2.4 GHz may only send
		 * a country IE with information for the 2.4 GHz band
		 * while 5 GHz is still supported.
		 */
		if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
		    r == -ERANGE)
			return;

		REG_DBG_PRINT("Disabling freq %d MHz\n", chan->center_freq);
		chan->flags = IEEE80211_CHAN_DISABLED;
		return;
	}

	chan_reg_rule_print_dbg(chan, desired_bw_khz, reg_rule);

	power_rule = &reg_rule->power_rule;
	freq_range = &reg_rule->freq_range;

	if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
		bw_flags = IEEE80211_CHAN_NO_HT40;

	if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
	    request_wiphy && request_wiphy == wiphy &&
	    request_wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY) {
		/*
		 * This guarantees the driver's requested regulatory domain
		 * will always be used as a base for further regulatory
		 * settings
		 */
		chan->flags = chan->orig_flags =
			map_regdom_flags(reg_rule->flags) | bw_flags;
		chan->max_antenna_gain = chan->orig_mag =
			(int) MBI_TO_DBI(power_rule->max_antenna_gain);
		chan->max_power = chan->orig_mpwr =
			(int) MBM_TO_DBM(power_rule->max_eirp);
		return;
	}

	chan->beacon_found = false;
	chan->flags = flags | bw_flags | map_regdom_flags(reg_rule->flags);
	chan->max_antenna_gain = min(chan->orig_mag,
		(int) MBI_TO_DBI(power_rule->max_antenna_gain));
	chan->max_reg_power = (int) MBM_TO_DBM(power_rule->max_eirp);
	chan->max_power = min(chan->max_power, chan->max_reg_power);
}

static void handle_band(struct wiphy *wiphy,
			enum ieee80211_band band,
			enum nl80211_reg_initiator initiator)
{
	unsigned int i;
	struct ieee80211_supported_band *sband;

	BUG_ON(!wiphy->bands[band]);
	sband = wiphy->bands[band];

	for (i = 0; i < sband->n_channels; i++)
		handle_channel(wiphy, initiator, band, i);
}

static bool ignore_reg_update(struct wiphy *wiphy,
			      enum nl80211_reg_initiator initiator)
{
	if (!last_request) {
		REG_DBG_PRINT("Ignoring regulatory request %s since "
			      "last_request is not set\n",
			      reg_initiator_name(initiator));
		return true;
	}

	if (initiator == NL80211_REGDOM_SET_BY_CORE &&
	    wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY) {
		REG_DBG_PRINT("Ignoring regulatory request %s "
			      "since the driver uses its own custom "
			      "regulatory domain\n",
			      reg_initiator_name(initiator));
		return true;
	}

	/*
	 * wiphy->regd will be set once the device has its own
	 * desired regulatory domain set
	 */
	if (wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY && !wiphy->regd &&
	    initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
	    !is_world_regdom(last_request->alpha2)) {
		REG_DBG_PRINT("Ignoring regulatory request %s "
			      "since the driver requires its own regulatory "
			      "domain to be set first\n",
			      reg_initiator_name(initiator));
		return true;
	}

	return false;
}

static void handle_reg_beacon(struct wiphy *wiphy,
			      unsigned int chan_idx,
			      struct reg_beacon *reg_beacon)
{
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *chan;
	bool channel_changed = false;
	struct ieee80211_channel chan_before;

	assert_cfg80211_lock();

	sband = wiphy->bands[reg_beacon->chan.band];
	chan = &sband->channels[chan_idx];

	if (likely(chan->center_freq != reg_beacon->chan.center_freq))
		return;

	if (chan->beacon_found)
		return;

	chan->beacon_found = true;

	if (wiphy->flags & WIPHY_FLAG_DISABLE_BEACON_HINTS)
		return;

	chan_before.center_freq = chan->center_freq;
	chan_before.flags = chan->flags;

	if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) {
		chan->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
		channel_changed = true;
	}

	if (chan->flags & IEEE80211_CHAN_NO_IBSS) {
		chan->flags &= ~IEEE80211_CHAN_NO_IBSS;
		channel_changed = true;
	}

	if (channel_changed)
		nl80211_send_beacon_hint_event(wiphy, &chan_before, chan);
}

/*
 * Called when a scan on a wiphy finds a beacon on
 * new channel
 */
static void wiphy_update_new_beacon(struct wiphy *wiphy,
				    struct reg_beacon *reg_beacon)
{
	unsigned int i;
	struct ieee80211_supported_band *sband;

	assert_cfg80211_lock();

	if (!wiphy->bands[reg_beacon->chan.band])
		return;

	sband = wiphy->bands[reg_beacon->chan.band];

	for (i = 0; i < sband->n_channels; i++)
		handle_reg_beacon(wiphy, i, reg_beacon);
}

/*
 * Called upon reg changes or a new wiphy is added
 */
static void wiphy_update_beacon_reg(struct wiphy *wiphy)
{
	unsigned int i;
	struct ieee80211_supported_band *sband;
	struct reg_beacon *reg_beacon;

	assert_cfg80211_lock();

	if (list_empty(&reg_beacon_list))
		return;

	list_for_each_entry(reg_beacon, &reg_beacon_list, list) {
		if (!wiphy->bands[reg_beacon->chan.band])
			continue;
		sband = wiphy->bands[reg_beacon->chan.band];
		for (i = 0; i < sband->n_channels; i++)
			handle_reg_beacon(wiphy, i, reg_beacon);
	}
}

static bool reg_is_world_roaming(struct wiphy *wiphy)
{
	if (is_world_regdom(cfg80211_regdomain->alpha2) ||
	    (wiphy->regd && is_world_regdom(wiphy->regd->alpha2)))
		return true;
	if (last_request &&
	    last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
	    wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY)
		return true;
	return false;
}

/* Reap the advantages of previously found beacons */
static void reg_process_beacons(struct wiphy *wiphy)
{
	/*
	 * Means we are just firing up cfg80211, so no beacons would
	 * have been processed yet.
	 */
	if (!last_request)
		return;
	if (!reg_is_world_roaming(wiphy))
		return;
	wiphy_update_beacon_reg(wiphy);
}

static bool is_ht40_not_allowed(struct ieee80211_channel *chan)
{
	if (!chan)
		return true;
	if (chan->flags & IEEE80211_CHAN_DISABLED)
		return true;
	/* This would happen when regulatory rules disallow HT40 completely */
	if (IEEE80211_CHAN_NO_HT40 == (chan->flags & (IEEE80211_CHAN_NO_HT40)))
		return true;
	return false;
}

static void reg_process_ht_flags_channel(struct wiphy *wiphy,
					 enum ieee80211_band band,
					 unsigned int chan_idx)
{
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *channel;
	struct ieee80211_channel *channel_before = NULL, *channel_after = NULL;
	unsigned int i;

	assert_cfg80211_lock();

	sband = wiphy->bands[band];
	BUG_ON(chan_idx >= sband->n_channels);
	channel = &sband->channels[chan_idx];

	if (is_ht40_not_allowed(channel)) {
		channel->flags |= IEEE80211_CHAN_NO_HT40;
		return;
	}

	/*
	 * We need to ensure the extension channels exist to
	 * be able to use HT40- or HT40+, this finds them (or not)
	 */
	for (i = 0; i < sband->n_channels; i++) {
		struct ieee80211_channel *c = &sband->channels[i];
		if (c->center_freq == (channel->center_freq - 20))
			channel_before = c;
		if (c->center_freq == (channel->center_freq + 20))
			channel_after = c;
	}

	/*
	 * Please note that this assumes target bandwidth is 20 MHz,
	 * if that ever changes we also need to change the below logic
	 * to include that as well.
	 */
	if (is_ht40_not_allowed(channel_before))
		channel->flags |= IEEE80211_CHAN_NO_HT40MINUS;
	else
		channel->flags &= ~IEEE80211_CHAN_NO_HT40MINUS;

	if (is_ht40_not_allowed(channel_after))
		channel->flags |= IEEE80211_CHAN_NO_HT40PLUS;
	else
		channel->flags &= ~IEEE80211_CHAN_NO_HT40PLUS;
}

static void reg_process_ht_flags_band(struct wiphy *wiphy,
				      enum ieee80211_band band)
{
	unsigned int i;
	struct ieee80211_supported_band *sband;

	BUG_ON(!wiphy->bands[band]);
	sband = wiphy->bands[band];

	for (i = 0; i < sband->n_channels; i++)
		reg_process_ht_flags_channel(wiphy, band, i);
}

static void reg_process_ht_flags(struct wiphy *wiphy)
{
	enum ieee80211_band band;

	if (!wiphy)
		return;

	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		if (wiphy->bands[band])
			reg_process_ht_flags_band(wiphy, band);
	}

}

static void wiphy_update_regulatory(struct wiphy *wiphy,
				    enum nl80211_reg_initiator initiator)
{
	enum ieee80211_band band;

	assert_reg_lock();

	if (ignore_reg_update(wiphy, initiator))
		return;

	last_request->dfs_region = cfg80211_regdomain->dfs_region;

	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		if (wiphy->bands[band])
			handle_band(wiphy, band, initiator);
	}

	reg_process_beacons(wiphy);
	reg_process_ht_flags(wiphy);
	if (wiphy->reg_notifier)
		wiphy->reg_notifier(wiphy, last_request);
}

void regulatory_update(struct wiphy *wiphy,
		       enum nl80211_reg_initiator setby)
{
	mutex_lock(&reg_mutex);
	wiphy_update_regulatory(wiphy, setby);
	mutex_unlock(&reg_mutex);
}

static void update_all_wiphy_regulatory(enum nl80211_reg_initiator initiator)
{
	struct cfg80211_registered_device *rdev;
	struct wiphy *wiphy;

	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
		wiphy = &rdev->wiphy;
		wiphy_update_regulatory(wiphy, initiator);
		/*
		 * Regulatory updates set by CORE are ignored for custom
		 * regulatory cards. Let us notify the changes to the driver,
		 * as some drivers used this to restore its orig_* reg domain.
		 */
		if (initiator == NL80211_REGDOM_SET_BY_CORE &&
		    wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY &&
		    wiphy->reg_notifier)
			wiphy->reg_notifier(wiphy, last_request);
	}
}

static void handle_channel_custom(struct wiphy *wiphy,
				  enum ieee80211_band band,
				  unsigned int chan_idx,
				  const struct ieee80211_regdomain *regd)
{
	int r;
	u32 desired_bw_khz = MHZ_TO_KHZ(20);
	u32 bw_flags = 0;
	const struct ieee80211_reg_rule *reg_rule = NULL;
	const struct ieee80211_power_rule *power_rule = NULL;
	const struct ieee80211_freq_range *freq_range = NULL;
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *chan;

	assert_reg_lock();

	sband = wiphy->bands[band];
	BUG_ON(chan_idx >= sband->n_channels);
	chan = &sband->channels[chan_idx];

	r = freq_reg_info_regd(wiphy,
			       MHZ_TO_KHZ(chan->center_freq),
			       desired_bw_khz,
			       &reg_rule,
			       regd);

	if (r) {
		REG_DBG_PRINT("Disabling freq %d MHz as custom "
			      "regd has no rule that fits a %d MHz "
			      "wide channel\n",
			      chan->center_freq,
			      KHZ_TO_MHZ(desired_bw_khz));
		chan->flags = IEEE80211_CHAN_DISABLED;
		return;
	}

	chan_reg_rule_print_dbg(chan, desired_bw_khz, reg_rule);

	power_rule = &reg_rule->power_rule;
	freq_range = &reg_rule->freq_range;

	if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
		bw_flags = IEEE80211_CHAN_NO_HT40;

	chan->flags |= map_regdom_flags(reg_rule->flags) | bw_flags;
	chan->max_antenna_gain = (int) MBI_TO_DBI(power_rule->max_antenna_gain);
	chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
}

static void handle_band_custom(struct wiphy *wiphy, enum ieee80211_band band,
			       const struct ieee80211_regdomain *regd)
{
	unsigned int i;
	struct ieee80211_supported_band *sband;

	BUG_ON(!wiphy->bands[band]);
	sband = wiphy->bands[band];

	for (i = 0; i < sband->n_channels; i++)
		handle_channel_custom(wiphy, band, i, regd);
}

/* Used by drivers prior to wiphy registration */
void wiphy_apply_custom_regulatory(struct wiphy *wiphy,
				   const struct ieee80211_regdomain *regd)
{
	enum ieee80211_band band;
	unsigned int bands_set = 0;

	mutex_lock(&reg_mutex);
	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		if (!wiphy->bands[band])
			continue;
		handle_band_custom(wiphy, band, regd);
		bands_set++;
	}
	mutex_unlock(&reg_mutex);

	/*
	 * no point in calling this if it won't have any effect
	 * on your device's supportd bands.
	 */
	WARN_ON(!bands_set);
}
EXPORT_SYMBOL(wiphy_apply_custom_regulatory);

/*
 * Return value which can be used by ignore_request() to indicate
 * it has been determined we should intersect two regulatory domains
 */
#define REG_INTERSECT	1

/* This has the logic which determines when a new request
 * should be ignored. */
static int ignore_request(struct wiphy *wiphy,
			  struct regulatory_request *pending_request)
{
	struct wiphy *last_wiphy = NULL;

	assert_cfg80211_lock();

	/* All initial requests are respected */
	if (!last_request)
		return 0;

	switch (pending_request->initiator) {
	case NL80211_REGDOM_SET_BY_CORE:
		return 0;
	case NL80211_REGDOM_SET_BY_COUNTRY_IE:

		last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

		if (unlikely(!is_an_alpha2(pending_request->alpha2)))
			return -EINVAL;
		if (last_request->initiator ==
		    NL80211_REGDOM_SET_BY_COUNTRY_IE) {
			if (last_wiphy != wiphy) {
				/*
				 * Two cards with two APs claiming different
				 * Country IE alpha2s. We could
				 * intersect them, but that seems unlikely
				 * to be correct. Reject second one for now.
				 */
				if (regdom_changes(pending_request->alpha2))
					return -EOPNOTSUPP;
				return -EALREADY;
			}
			/*
			 * Two consecutive Country IE hints on the same wiphy.
			 * This should be picked up early by the driver/stack
			 */
			if (WARN_ON(regdom_changes(pending_request->alpha2)))
				return 0;
			return -EALREADY;
		}
		return 0;
	case NL80211_REGDOM_SET_BY_DRIVER:
		if (last_request->initiator == NL80211_REGDOM_SET_BY_CORE) {
			if (regdom_changes(pending_request->alpha2))
				return 0;
			return -EALREADY;
		}

		/*
		 * This would happen if you unplug and plug your card
		 * back in or if you add a new device for which the previously
		 * loaded card also agrees on the regulatory domain.
		 */
		if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
		    !regdom_changes(pending_request->alpha2))
			return -EALREADY;

		return REG_INTERSECT;
	case NL80211_REGDOM_SET_BY_USER:
		if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)
			return REG_INTERSECT;
		/*
		 * If the user knows better the user should set the regdom
		 * to their country before the IE is picked up
		 */
		if (last_request->initiator == NL80211_REGDOM_SET_BY_USER &&
			  last_request->intersect)
			return -EOPNOTSUPP;
		/*
		 * Process user requests only after previous user/driver/core
		 * requests have been processed
		 */
		if (last_request->initiator == NL80211_REGDOM_SET_BY_CORE ||
		    last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
		    last_request->initiator == NL80211_REGDOM_SET_BY_USER) {
			if (regdom_changes(last_request->alpha2))
				return -EAGAIN;
		}

		if (!regdom_changes(pending_request->alpha2))
			return -EALREADY;

		return 0;
	}

	return -EINVAL;
}

static void reg_set_request_processed(void)
{
	bool need_more_processing = false;

	last_request->processed = true;

	spin_lock(&reg_requests_lock);
	if (!list_empty(&reg_requests_list))
		need_more_processing = true;
	spin_unlock(&reg_requests_lock);

	if (last_request->initiator == NL80211_REGDOM_SET_BY_USER)
		cancel_delayed_work(&reg_timeout);

	if (need_more_processing)
		schedule_work(&reg_work);
}

/**
 * __regulatory_hint - hint to the wireless core a regulatory domain
 * @wiphy: if the hint comes from country information from an AP, this
 *	is required to be set to the wiphy that received the information
 * @pending_request: the regulatory request currently being processed
 *
 * The Wireless subsystem can use this function to hint to the wireless core
 * what it believes should be the current regulatory domain.
 *
 * Returns zero if all went fine, %-EALREADY if a regulatory domain had
 * already been set or other standard error codes.
 *
 * Caller must hold &cfg80211_mutex and &reg_mutex
 */
static int __regulatory_hint(struct wiphy *wiphy,
			     struct regulatory_request *pending_request)
{
	bool intersect = false;
	int r = 0;

	assert_cfg80211_lock();

	r = ignore_request(wiphy, pending_request);

	if (r == REG_INTERSECT) {
		if (pending_request->initiator ==
		    NL80211_REGDOM_SET_BY_DRIVER) {
			r = reg_copy_regd(&wiphy->regd, cfg80211_regdomain);
			if (r) {
				kfree(pending_request);
				return r;
			}
		}
		intersect = true;
	} else if (r) {
		/*
		 * If the regulatory domain being requested by the
		 * driver has already been set just copy it to the
		 * wiphy
		 */
		if (r == -EALREADY &&
		    pending_request->initiator ==
		    NL80211_REGDOM_SET_BY_DRIVER) {
			r = reg_copy_regd(&wiphy->regd, cfg80211_regdomain);
			if (r) {
				kfree(pending_request);
				return r;
			}
			r = -EALREADY;
			goto new_request;
		}
		kfree(pending_request);
		return r;
	}

new_request:
	if (last_request != &core_request_world)
		kfree(last_request);

	last_request = pending_request;
	last_request->intersect = intersect;

	pending_request = NULL;

	if (last_request->initiator == NL80211_REGDOM_SET_BY_USER) {
		user_alpha2[0] = last_request->alpha2[0];
		user_alpha2[1] = last_request->alpha2[1];
	}

	/* When r == REG_INTERSECT we do need to call CRDA */
	if (r < 0) {
		/*
		 * Since CRDA will not be called in this case as we already
		 * have applied the requested regulatory domain before we just
		 * inform userspace we have processed the request
		 */
		if (r == -EALREADY) {
			nl80211_send_reg_change_event(last_request);
			reg_set_request_processed();
		}
		return r;
	}

	return call_crda(last_request->alpha2);
}

/* This processes *all* regulatory hints */
static void reg_process_hint(struct regulatory_request *reg_request,
			     enum nl80211_reg_initiator reg_initiator)
{
	int r = 0;
	struct wiphy *wiphy = NULL;

	BUG_ON(!reg_request->alpha2);

	if (wiphy_idx_valid(reg_request->wiphy_idx))
		wiphy = wiphy_idx_to_wiphy(reg_request->wiphy_idx);

	if (reg_initiator == NL80211_REGDOM_SET_BY_DRIVER &&
	    !wiphy) {
		kfree(reg_request);
		return;
	}

	r = __regulatory_hint(wiphy, reg_request);
	/* This is required so that the orig_* parameters are saved */
	if (r == -EALREADY && wiphy &&
	    wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY) {
		wiphy_update_regulatory(wiphy, reg_initiator);
		return;
	}

	/*
	 * We only time out user hints, given that they should be the only
	 * source of bogus requests.
	 */
	if (r != -EALREADY &&
	    reg_initiator == NL80211_REGDOM_SET_BY_USER)
		schedule_delayed_work(&reg_timeout, msecs_to_jiffies(3142));
}

/*
 * Processes regulatory hints, this is all the NL80211_REGDOM_SET_BY_*
 * Regulatory hints come on a first come first serve basis and we
 * must process each one atomically.
 */
static void reg_process_pending_hints(void)
{
	struct regulatory_request *reg_request;

	mutex_lock(&cfg80211_mutex);
	mutex_lock(&reg_mutex);

	/* When last_request->processed becomes true this will be rescheduled */
	if (last_request && !last_request->processed) {
		REG_DBG_PRINT("Pending regulatory request, waiting "
			      "for it to be processed...\n");
		goto out;
	}

	spin_lock(&reg_requests_lock);

	if (list_empty(&reg_requests_list)) {
		spin_unlock(&reg_requests_lock);
		goto out;
	}

	reg_request = list_first_entry(&reg_requests_list,
				       struct regulatory_request,
				       list);
	list_del_init(&reg_request->list);

	spin_unlock(&reg_requests_lock);

	reg_process_hint(reg_request, reg_request->initiator);

out:
	mutex_unlock(&reg_mutex);
	mutex_unlock(&cfg80211_mutex);
}

/* Processes beacon hints -- this has nothing to do with country IEs */
static void reg_process_pending_beacon_hints(void)
{
	struct cfg80211_registered_device *rdev;
	struct reg_beacon *pending_beacon, *tmp;

	/*
	 * No need to hold the reg_mutex here as we just touch wiphys
	 * and do not read or access regulatory variables.
	 */
	mutex_lock(&cfg80211_mutex);

	/* This goes through the _pending_ beacon list */
	spin_lock_bh(&reg_pending_beacons_lock);

	if (list_empty(&reg_pending_beacons)) {
		spin_unlock_bh(&reg_pending_beacons_lock);
		goto out;
	}

	list_for_each_entry_safe(pending_beacon, tmp,
				 &reg_pending_beacons, list) {

		list_del_init(&pending_beacon->list);

		/* Applies the beacon hint to current wiphys */
		list_for_each_entry(rdev, &cfg80211_rdev_list, list)
			wiphy_update_new_beacon(&rdev->wiphy, pending_beacon);

		/* Remembers the beacon hint for new wiphys or reg changes */
		list_add_tail(&pending_beacon->list, &reg_beacon_list);
	}

	spin_unlock_bh(&reg_pending_beacons_lock);
out:
	mutex_unlock(&cfg80211_mutex);
}

static void reg_todo(struct work_struct *work)
{
	reg_process_pending_hints();
	reg_process_pending_beacon_hints();
}

static void queue_regulatory_request(struct regulatory_request *request)
{
	if (isalpha(request->alpha2[0]))
		request->alpha2[0] = toupper(request->alpha2[0]);
	if (isalpha(request->alpha2[1]))
		request->alpha2[1] = toupper(request->alpha2[1]);

	spin_lock(&reg_requests_lock);
	list_add_tail(&request->list, &reg_requests_list);
	spin_unlock(&reg_requests_lock);

	schedule_work(&reg_work);
}

/*
 * Core regulatory hint -- happens during cfg80211_init()
 * and when we restore regulatory settings.
 */
static int regulatory_hint_core(const char *alpha2)
{
	struct regulatory_request *request;

	request = kzalloc(sizeof(struct regulatory_request),
			  GFP_KERNEL);
	if (!request)
		return -ENOMEM;

	request->alpha2[0] = alpha2[0];
	request->alpha2[1] = alpha2[1];
	request->initiator = NL80211_REGDOM_SET_BY_CORE;

	queue_regulatory_request(request);

	return 0;
}

/* User hints */
int regulatory_hint_user(const char *alpha2)
{
	struct regulatory_request *request;

	BUG_ON(!alpha2);

	request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
	if (!request)
		return -ENOMEM;

	request->wiphy_idx = WIPHY_IDX_STALE;
	request->alpha2[0] = alpha2[0];
	request->alpha2[1] = alpha2[1];
	request->initiator = NL80211_REGDOM_SET_BY_USER;

	queue_regulatory_request(request);

	return 0;
}

/* Driver hints */
int regulatory_hint(struct wiphy *wiphy, const char *alpha2)
{
	struct regulatory_request *request;

	BUG_ON(!alpha2);
	BUG_ON(!wiphy);

	request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
	if (!request)
		return -ENOMEM;

	request->wiphy_idx = get_wiphy_idx(wiphy);

	/* Must have registered wiphy first */
	BUG_ON(!wiphy_idx_valid(request->wiphy_idx));

	request->alpha2[0] = alpha2[0];
	request->alpha2[1] = alpha2[1];
	request->initiator = NL80211_REGDOM_SET_BY_DRIVER;

	queue_regulatory_request(request);

	return 0;
}
EXPORT_SYMBOL(regulatory_hint);

/*
 * We hold wdev_lock() here so we cannot hold cfg80211_mutex() and
 * therefore cannot iterate over the rdev list here.
 */
void regulatory_hint_11d(struct wiphy *wiphy,
			 enum ieee80211_band band,
			 u8 *country_ie,
			 u8 country_ie_len)
{
	char alpha2[2];
	enum environment_cap env = ENVIRON_ANY;
	struct regulatory_request *request;

	mutex_lock(&reg_mutex);

	if (unlikely(!last_request))
		goto out;

	/* IE len must be evenly divisible by 2 */
	if (country_ie_len & 0x01)
		goto out;

	if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
		goto out;

	alpha2[0] = country_ie[0];
	alpha2[1] = country_ie[1];

	if (country_ie[2] == 'I')
		env = ENVIRON_INDOOR;
	else if (country_ie[2] == 'O')
		env = ENVIRON_OUTDOOR;

	/*
	 * We will run this only upon a successful connection on cfg80211.
	 * We leave conflict resolution to the workqueue, where can hold
	 * cfg80211_mutex.
	 */
	if (likely(last_request->initiator ==
	    NL80211_REGDOM_SET_BY_COUNTRY_IE &&
	    wiphy_idx_valid(last_request->wiphy_idx)))
		goto out;

	request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
	if (!request)
		goto out;

	request->wiphy_idx = get_wiphy_idx(wiphy);
	request->alpha2[0] = alpha2[0];
	request->alpha2[1] = alpha2[1];
	request->initiator = NL80211_REGDOM_SET_BY_COUNTRY_IE;
	request->country_ie_env = env;

	mutex_unlock(&reg_mutex);

	queue_regulatory_request(request);

	return;

out:
	mutex_unlock(&reg_mutex);
}

static void restore_alpha2(char *alpha2, bool reset_user)
{
	/* indicates there is no alpha2 to consider for restoration */
	alpha2[0] = '9';
	alpha2[1] = '7';

	/* The user setting has precedence over the module parameter */
	if (is_user_regdom_saved()) {
		/* Unless we're asked to ignore it and reset it */
		if (reset_user) {
			REG_DBG_PRINT("Restoring regulatory settings "
			       "including user preference\n");
			user_alpha2[0] = '9';
			user_alpha2[1] = '7';

			/*
			 * If we're ignoring user settings, we still need to
			 * check the module parameter to ensure we put things
			 * back as they were for a full restore.
			 */
			if (!is_world_regdom(ieee80211_regdom)) {
				REG_DBG_PRINT("Keeping preference on "
				       "module parameter ieee80211_regdom: %c%c\n",
				       ieee80211_regdom[0],
				       ieee80211_regdom[1]);
				alpha2[0] = ieee80211_regdom[0];
				alpha2[1] = ieee80211_regdom[1];
			}
		} else {
			REG_DBG_PRINT("Restoring regulatory settings "
			       "while preserving user preference for: %c%c\n",
			       user_alpha2[0],
			       user_alpha2[1]);
			alpha2[0] = user_alpha2[0];
			alpha2[1] = user_alpha2[1];
		}
	} else if (!is_world_regdom(ieee80211_regdom)) {
		REG_DBG_PRINT("Keeping preference on "
		       "module parameter ieee80211_regdom: %c%c\n",
		       ieee80211_regdom[0],
		       ieee80211_regdom[1]);
		alpha2[0] = ieee80211_regdom[0];
		alpha2[1] = ieee80211_regdom[1];
	} else
		REG_DBG_PRINT("Restoring regulatory settings\n");
}

static void restore_custom_reg_settings(struct wiphy *wiphy)
{
	struct ieee80211_supported_band *sband;
	enum ieee80211_band band;
	struct ieee80211_channel *chan;
	int i;

	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		sband = wiphy->bands[band];
		if (!sband)
			continue;
		for (i = 0; i < sband->n_channels; i++) {
			chan = &sband->channels[i];
			chan->flags = chan->orig_flags;
			chan->max_antenna_gain = chan->orig_mag;
			chan->max_power = chan->orig_mpwr;
		}
	}
}

/*
 * Restoring regulatory settings involves ingoring any
 * possibly stale country IE information and user regulatory
 * settings if so desired, this includes any beacon hints
 * learned as we could have traveled outside to another country
 * after disconnection. To restore regulatory settings we do
 * exactly what we did at bootup:
 *
 *   - send a core regulatory hint
 *   - send a user regulatory hint if applicable
 *
 * Device drivers that send a regulatory hint for a specific country
 * keep their own regulatory domain on wiphy->regd so that does does
 * not need to be remembered.
 */
static void restore_regulatory_settings(bool reset_user)
{
	char alpha2[2];
	char world_alpha2[2];
	struct reg_beacon *reg_beacon, *btmp;
	struct regulatory_request *reg_request, *tmp;
	LIST_HEAD(tmp_reg_req_list);
	struct cfg80211_registered_device *rdev;

	mutex_lock(&cfg80211_mutex);
	mutex_lock(&reg_mutex);

	reset_regdomains(true);
	restore_alpha2(alpha2, reset_user);

	/*
	 * If there's any pending requests we simply
	 * stash them to a temporary pending queue and
	 * add then after we've restored regulatory
	 * settings.
	 */
	spin_lock(&reg_requests_lock);
	if (!list_empty(&reg_requests_list)) {
		list_for_each_entry_safe(reg_request, tmp,
					 &reg_requests_list, list) {
			if (reg_request->initiator !=
			    NL80211_REGDOM_SET_BY_USER)
				continue;
			list_del(&reg_request->list);
			list_add_tail(&reg_request->list, &tmp_reg_req_list);
		}
	}
	spin_unlock(&reg_requests_lock);

	/* Clear beacon hints */
	spin_lock_bh(&reg_pending_beacons_lock);
	if (!list_empty(&reg_pending_beacons)) {
		list_for_each_entry_safe(reg_beacon, btmp,
					 &reg_pending_beacons, list) {
			list_del(&reg_beacon->list);
			kfree(reg_beacon);
		}
	}
	spin_unlock_bh(&reg_pending_beacons_lock);

	if (!list_empty(&reg_beacon_list)) {
		list_for_each_entry_safe(reg_beacon, btmp,
					 &reg_beacon_list, list) {
			list_del(&reg_beacon->list);
			kfree(reg_beacon);
		}
	}

	/* First restore to the basic regulatory settings */
	cfg80211_regdomain = cfg80211_world_regdom;
	world_alpha2[0] = cfg80211_regdomain->alpha2[0];
	world_alpha2[1] = cfg80211_regdomain->alpha2[1];

	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
		if (rdev->wiphy.flags & WIPHY_FLAG_CUSTOM_REGULATORY)
			restore_custom_reg_settings(&rdev->wiphy);
	}

	mutex_unlock(&reg_mutex);
	mutex_unlock(&cfg80211_mutex);

	regulatory_hint_core(world_alpha2);

	/*
	 * This restores the ieee80211_regdom module parameter
	 * preference or the last user requested regulatory
	 * settings, user regulatory settings takes precedence.
	 */
	if (is_an_alpha2(alpha2))
		regulatory_hint_user(user_alpha2);

	if (list_empty(&tmp_reg_req_list))
		return;

	mutex_lock(&cfg80211_mutex);
	mutex_lock(&reg_mutex);

	spin_lock(&reg_requests_lock);
	list_for_each_entry_safe(reg_request, tmp, &tmp_reg_req_list, list) {
		REG_DBG_PRINT("Adding request for country %c%c back "
			      "into the queue\n",
			      reg_request->alpha2[0],
			      reg_request->alpha2[1]);
		list_del(&reg_request->list);
		list_add_tail(&reg_request->list, &reg_requests_list);
	}
	spin_unlock(&reg_requests_lock);

	mutex_unlock(&reg_mutex);
	mutex_unlock(&cfg80211_mutex);

	REG_DBG_PRINT("Kicking the queue\n");

	schedule_work(&reg_work);
}

void regulatory_hint_disconnect(void)
{
	REG_DBG_PRINT("All devices are disconnected, going to "
		      "restore regulatory settings\n");
	restore_regulatory_settings(false);
}

static bool freq_is_chan_12_13_14(u16 freq)
{
	if (freq == ieee80211_channel_to_frequency(12, IEEE80211_BAND_2GHZ) ||
	    freq == ieee80211_channel_to_frequency(13, IEEE80211_BAND_2GHZ) ||
	    freq == ieee80211_channel_to_frequency(14, IEEE80211_BAND_2GHZ))
		return true;
	return false;
}

int regulatory_hint_found_beacon(struct wiphy *wiphy,
				 struct ieee80211_channel *beacon_chan,
				 gfp_t gfp)
{
	struct reg_beacon *reg_beacon;

	if (likely((beacon_chan->beacon_found ||
	    (beacon_chan->flags & IEEE80211_CHAN_RADAR) ||
	    (beacon_chan->band == IEEE80211_BAND_2GHZ &&
	     !freq_is_chan_12_13_14(beacon_chan->center_freq)))))
		return 0;

	reg_beacon = kzalloc(sizeof(struct reg_beacon), gfp);
	if (!reg_beacon)
		return -ENOMEM;

	REG_DBG_PRINT("Found new beacon on "
		      "frequency: %d MHz (Ch %d) on %s\n",
		      beacon_chan->center_freq,
		      ieee80211_frequency_to_channel(beacon_chan->center_freq),
		      wiphy_name(wiphy));

	memcpy(&reg_beacon->chan, beacon_chan,
		sizeof(struct ieee80211_channel));


	/*
	 * Since we can be called from BH or and non-BH context
	 * we must use spin_lock_bh()
	 */
	spin_lock_bh(&reg_pending_beacons_lock);
	list_add_tail(&reg_beacon->list, &reg_pending_beacons);
	spin_unlock_bh(&reg_pending_beacons_lock);

	schedule_work(&reg_work);

	return 0;
}

static void print_rd_rules(const struct ieee80211_regdomain *rd)
{
	unsigned int i;
	const struct ieee80211_reg_rule *reg_rule = NULL;
	const struct ieee80211_freq_range *freq_range = NULL;
	const struct ieee80211_power_rule *power_rule = NULL;

	pr_info("  (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)\n");

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		freq_range = &reg_rule->freq_range;
		power_rule = &reg_rule->power_rule;

		/*
		 * There may not be documentation for max antenna gain
		 * in certain regions
		 */
		if (power_rule->max_antenna_gain)
			pr_info("  (%d KHz - %d KHz @ %d KHz), (%d mBi, %d mBm)\n",
				freq_range->start_freq_khz,
				freq_range->end_freq_khz,
				freq_range->max_bandwidth_khz,
				power_rule->max_antenna_gain,
				power_rule->max_eirp);
		else
			pr_info("  (%d KHz - %d KHz @ %d KHz), (N/A, %d mBm)\n",
				freq_range->start_freq_khz,
				freq_range->end_freq_khz,
				freq_range->max_bandwidth_khz,
				power_rule->max_eirp);
	}
}

bool reg_supported_dfs_region(u8 dfs_region)
{
	switch (dfs_region) {
	case NL80211_DFS_UNSET:
	case NL80211_DFS_FCC:
	case NL80211_DFS_ETSI:
	case NL80211_DFS_JP:
		return true;
	default:
		REG_DBG_PRINT("Ignoring uknown DFS master region: %d\n",
			      dfs_region);
		return false;
	}
}

static void print_dfs_region(u8 dfs_region)
{
	if (!dfs_region)
		return;

	switch (dfs_region) {
	case NL80211_DFS_FCC:
		pr_info(" DFS Master region FCC");
		break;
	case NL80211_DFS_ETSI:
		pr_info(" DFS Master region ETSI");
		break;
	case NL80211_DFS_JP:
		pr_info(" DFS Master region JP");
		break;
	default:
		pr_info(" DFS Master region Uknown");
		break;
	}
}

static void print_regdomain(const struct ieee80211_regdomain *rd)
{

	if (is_intersected_alpha2(rd->alpha2)) {

		if (last_request->initiator ==
		    NL80211_REGDOM_SET_BY_COUNTRY_IE) {
			struct cfg80211_registered_device *rdev;
			rdev = cfg80211_rdev_by_wiphy_idx(
				last_request->wiphy_idx);
			if (rdev) {
				pr_info("Current regulatory domain updated by AP to: %c%c\n",
					rdev->country_ie_alpha2[0],
					rdev->country_ie_alpha2[1]);
			} else
				pr_info("Current regulatory domain intersected:\n");
		} else
			pr_info("Current regulatory domain intersected:\n");
	} else if (is_world_regdom(rd->alpha2))
		pr_info("World regulatory domain updated:\n");
	else {
		if (is_unknown_alpha2(rd->alpha2))
			pr_info("Regulatory domain changed to driver built-in settings (unknown country)\n");
		else
			pr_info("Regulatory domain changed to country: %c%c\n",
				rd->alpha2[0], rd->alpha2[1]);
	}
	print_dfs_region(rd->dfs_region);
	print_rd_rules(rd);
}

static void print_regdomain_info(const struct ieee80211_regdomain *rd)
{
	pr_info("Regulatory domain: %c%c\n", rd->alpha2[0], rd->alpha2[1]);
	print_rd_rules(rd);
}

/* Takes ownership of rd only if it doesn't fail */
static int __set_regdom(const struct ieee80211_regdomain *rd)
{
	const struct ieee80211_regdomain *intersected_rd = NULL;
	struct cfg80211_registered_device *rdev = NULL;
	struct wiphy *request_wiphy;
	/* Some basic sanity checks first */

	if (is_world_regdom(rd->alpha2)) {
		if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
			return -EINVAL;
		update_world_regdomain(rd);
		return 0;
	}

	if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
			!is_unknown_alpha2(rd->alpha2))
		return -EINVAL;

	if (!last_request)
		return -EINVAL;

	/*
	 * Lets only bother proceeding on the same alpha2 if the current
	 * rd is non static (it means CRDA was present and was used last)
	 * and the pending request came in from a country IE
	 */
	if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
		/*
		 * If someone else asked us to change the rd lets only bother
		 * checking if the alpha2 changes if CRDA was already called
		 */
		if (!regdom_changes(rd->alpha2))
			return -EINVAL;
	}

	/*
	 * Now lets set the regulatory domain, update all driver channels
	 * and finally inform them of what we have done, in case they want
	 * to review or adjust their own settings based on their own
	 * internal EEPROM data
	 */

	if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
		return -EINVAL;

	if (!is_valid_rd(rd)) {
		pr_err("Invalid regulatory domain detected:\n");
		print_regdomain_info(rd);
		return -EINVAL;
	}

	request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
	if (!request_wiphy &&
	    (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
	     last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)) {
		schedule_delayed_work(&reg_timeout, 0);
		return -ENODEV;
	}

	if (!last_request->intersect) {
		int r;

		if (last_request->initiator != NL80211_REGDOM_SET_BY_DRIVER) {
			reset_regdomains(false);
			cfg80211_regdomain = rd;
			return 0;
		}

		/*
		 * For a driver hint, lets copy the regulatory domain the
		 * driver wanted to the wiphy to deal with conflicts
		 */

		/*
		 * Userspace could have sent two replies with only
		 * one kernel request.
		 */
		if (request_wiphy->regd)
			return -EALREADY;

		r = reg_copy_regd(&request_wiphy->regd, rd);
		if (r)
			return r;

		reset_regdomains(false);
		cfg80211_regdomain = rd;
		return 0;
	}

	/* Intersection requires a bit more work */

	if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {

		intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
		if (!intersected_rd)
			return -EINVAL;

		/*
		 * We can trash what CRDA provided now.
		 * However if a driver requested this specific regulatory
		 * domain we keep it for its private use
		 */
		if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER)
			request_wiphy->regd = rd;
		else
			kfree(rd);

		rd = NULL;

		reset_regdomains(false);
		cfg80211_regdomain = intersected_rd;

		return 0;
	}

	if (!intersected_rd)
		return -EINVAL;

	rdev = wiphy_to_dev(request_wiphy);

	rdev->country_ie_alpha2[0] = rd->alpha2[0];
	rdev->country_ie_alpha2[1] = rd->alpha2[1];
	rdev->env = last_request->country_ie_env;

	BUG_ON(intersected_rd == rd);

	kfree(rd);
	rd = NULL;

	reset_regdomains(false);
	cfg80211_regdomain = intersected_rd;

	return 0;
}


/*
 * Use this call to set the current regulatory domain. Conflicts with
 * multiple drivers can be ironed out later. Caller must've already
 * kmalloc'd the rd structure. Caller must hold cfg80211_mutex
 */
int set_regdom(const struct ieee80211_regdomain *rd)
{
	int r;

	assert_cfg80211_lock();

	mutex_lock(&reg_mutex);

	/* Note that this doesn't update the wiphys, this is done below */
	r = __set_regdom(rd);
	if (r) {
		kfree(rd);
		mutex_unlock(&reg_mutex);
		return r;
	}

	/* This would make this whole thing pointless */
	if (!last_request->intersect)
		BUG_ON(rd != cfg80211_regdomain);

	/* update all wiphys now with the new established regulatory domain */
	update_all_wiphy_regulatory(last_request->initiator);

	print_regdomain(cfg80211_regdomain);

	nl80211_send_reg_change_event(last_request);

	reg_set_request_processed();

	mutex_unlock(&reg_mutex);

	return r;
}

#ifdef CONFIG_HOTPLUG
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	if (last_request && !last_request->processed) {
		if (add_uevent_var(env, "COUNTRY=%c%c",
				   last_request->alpha2[0],
				   last_request->alpha2[1]))
			return -ENOMEM;
	}

	return 0;
}
#else
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	return -ENODEV;
}
#endif /* CONFIG_HOTPLUG */

/* Caller must hold cfg80211_mutex */
void reg_device_remove(struct wiphy *wiphy)
{
	struct wiphy *request_wiphy = NULL;

	assert_cfg80211_lock();

	mutex_lock(&reg_mutex);

	kfree(wiphy->regd);

	if (last_request)
		request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

	if (!request_wiphy || request_wiphy != wiphy)
		goto out;

	last_request->wiphy_idx = WIPHY_IDX_STALE;
	last_request->country_ie_env = ENVIRON_ANY;
out:
	mutex_unlock(&reg_mutex);
}

static void reg_timeout_work(struct work_struct *work)
{
	REG_DBG_PRINT("Timeout while waiting for CRDA to reply, "
		      "restoring regulatory settings\n");
	restore_regulatory_settings(true);
}

int __init regulatory_init(void)
{
	int err = 0;

	reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
	if (IS_ERR(reg_pdev))
		return PTR_ERR(reg_pdev);

	reg_pdev->dev.type = &reg_device_type;

	spin_lock_init(&reg_requests_lock);
	spin_lock_init(&reg_pending_beacons_lock);

	reg_regdb_size_check();

	cfg80211_regdomain = cfg80211_world_regdom;

	user_alpha2[0] = '9';
	user_alpha2[1] = '7';

	/* We always try to get an update for the static regdomain */
	err = regulatory_hint_core(cfg80211_regdomain->alpha2);
	if (err) {
		if (err == -ENOMEM)
			return err;
		/*
		 * N.B. kobject_uevent_env() can fail mainly for when we're out
		 * memory which is handled and propagated appropriately above
		 * but it can also fail during a netlink_broadcast() or during
		 * early boot for call_usermodehelper(). For now treat these
		 * errors as non-fatal.
		 */
		pr_err("kobject_uevent_env() was unable to call CRDA during init\n");
#ifdef CONFIG_CFG80211_REG_DEBUG
		/* We want to find out exactly why when debugging */
		WARN_ON(err);
#endif
	}

	/*
	 * Finally, if the user set the module parameter treat it
	 * as a user hint.
	 */
	if (!is_world_regdom(ieee80211_regdom))
		regulatory_hint_user(ieee80211_regdom);

	return 0;
}

void /* __init_or_exit */ regulatory_exit(void)
{
	struct regulatory_request *reg_request, *tmp;
	struct reg_beacon *reg_beacon, *btmp;

	cancel_work_sync(&reg_work);
	cancel_delayed_work_sync(&reg_timeout);

	mutex_lock(&cfg80211_mutex);
	mutex_lock(&reg_mutex);

	reset_regdomains(true);

	dev_set_uevent_suppress(&reg_pdev->dev, true);

	platform_device_unregister(reg_pdev);

	spin_lock_bh(&reg_pending_beacons_lock);
	if (!list_empty(&reg_pending_beacons)) {
		list_for_each_entry_safe(reg_beacon, btmp,
					 &reg_pending_beacons, list) {
			list_del(&reg_beacon->list);
			kfree(reg_beacon);
		}
	}
	spin_unlock_bh(&reg_pending_beacons_lock);

	if (!list_empty(&reg_beacon_list)) {
		list_for_each_entry_safe(reg_beacon, btmp,
					 &reg_beacon_list, list) {
			list_del(&reg_beacon->list);
			kfree(reg_beacon);
		}
	}

	spin_lock(&reg_requests_lock);
	if (!list_empty(&reg_requests_list)) {
		list_for_each_entry_safe(reg_request, tmp,
					 &reg_requests_list, list) {
			list_del(&reg_request->list);
			kfree(reg_request);
		}
	}
	spin_unlock(&reg_requests_lock);

	mutex_unlock(&reg_mutex);
	mutex_unlock(&cfg80211_mutex);
}