File: reglib.c

package info (click to toggle)
crda 4.14%2Bgit20191112.9856751-1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm, bullseye, sid
  • size: 568 kB
  • sloc: ansic: 2,599; makefile: 195; python: 130; sh: 6
file content (1336 lines) | stat: -rw-r--r-- 31,675 bytes parent folder | download
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
#include <errno.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <limits.h>

#include <arpa/inet.h> /* ntohl */

#include "reglib.h"
#include "regdb.h"

#ifdef USE_OPENSSL
#include <openssl/objects.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
#include <openssl/pem.h>
#endif

#ifdef USE_GCRYPT
#include <gcrypt.h>
#endif

#include "reglib.h"

#if defined(USE_OPENSSL) && defined(HAVE_KEYS_SSL)
#include "keys-ssl.c"
#endif

#ifdef USE_GCRYPT
#include "keys-gcrypt.c"
#endif

int debug = 0;

void *
reglib_get_file_ptr(uint8_t *db, size_t dblen, size_t structlen, uint32_t ptr)
{
	uint32_t p = ntohl(ptr);

	if (structlen > dblen) {
		fprintf(stderr, "Invalid database file, too short!\n");
		exit(3);
	}

	if (p > dblen - structlen) {
		fprintf(stderr, "Invalid database file, bad pointer!\n");
		exit(3);
	}

	return (void *)(db + p);
}

static size_t
reglib_array_len(size_t baselen, unsigned int elemcount, size_t elemlen)
{
	if (elemcount > (SIZE_MAX - baselen) / elemlen) {
		fprintf(stderr, "Invalid database file, count too large!\n");
		exit(3);
	}

	return baselen + elemcount * elemlen;
}

/*
 * reglib_verify_db_signature():
 *
 * Checks the validity of the signature found on the regulatory
 * database against the array 'keys'. Returns 1 if there exists
 * at least one key in the array such that the signature is valid
 * against that key; 0 otherwise.
 */

#ifdef USE_OPENSSL
int reglib_verify_db_signature(uint8_t *db, size_t dblen, size_t siglen)
{
	RSA *rsa;
	uint8_t hash[SHA_DIGEST_LENGTH];
	int ok = 0;
	DIR *pubkey_dir;
	struct dirent *nextfile;
	FILE *keyfile;
	char filename[PATH_MAX];

	if (SHA1(db, dblen, hash) != hash) {
		fprintf(stderr, "Failed to calculate SHA1 sum.\n");
		goto out;
	}

#ifdef HAVE_KEYS_SSL
	unsigned int i;
	for (i = 0; (i < sizeof(keys)/sizeof(keys[0])) && (!ok); i++) {
		rsa = RSA_new();
		if (!rsa) {
			fprintf(stderr, "Failed to create RSA key.\n");
			goto out;
		}

		rsa->e = &keys[i].e;
		rsa->n = &keys[i].n;

		ok = RSA_verify(NID_sha1, hash, SHA_DIGEST_LENGTH,
				db + dblen, siglen, rsa) == 1;

		rsa->e = NULL;
		rsa->n = NULL;
		RSA_free(rsa);
	}
#endif
	if (!ok && (pubkey_dir = opendir(PUBKEY_DIR))) {
		while (!ok && (nextfile = readdir(pubkey_dir))) {
			snprintf(filename, PATH_MAX, "%s/%s", PUBKEY_DIR,
				nextfile->d_name);
			if ((keyfile = fopen(filename, "rb"))) {
				rsa = PEM_read_RSA_PUBKEY(keyfile,
					NULL, NULL, NULL);
				if (rsa)
					ok = RSA_verify(NID_sha1, hash, SHA_DIGEST_LENGTH,
						db + dblen, siglen, rsa) == 1;
				RSA_free(rsa);
				fclose(keyfile);
			}
		}
		closedir(pubkey_dir);
	}

	if (!ok)
		fprintf(stderr, "Database signature verification failed.\n");

out:
	return ok;
}
#endif /* USE_OPENSSL */

#ifdef USE_GCRYPT
int reglib_verify_db_signature(uint8_t *db, size_t dblen, size_t siglen)
{
	gcry_mpi_t mpi_e, mpi_n;
	gcry_sexp_t rsa, signature, data;
	uint8_t hash[20];
	unsigned int i;
	int ok = 0;

	/* initialise */
	gcry_check_version(NULL);

	/* hash the db */
	gcry_md_hash_buffer(GCRY_MD_SHA1, hash, db, dblen);

	if (gcry_sexp_build(&data, NULL, "(data (flags pkcs1) (hash sha1 %b))",
			    20, hash)) {
		fprintf(stderr, "Failed to build data S-expression.\n");
		return ok;
	}

	if (gcry_sexp_build(&signature, NULL, "(sig-val (rsa (s %b)))",
			    siglen, db + dblen)) {
		fprintf(stderr, "Failed to build signature S-expression.\n");
		gcry_sexp_release(data);
		return ok;
	}

	for (i = 0; (i < sizeof(keys)/sizeof(keys[0])) && (!ok); i++) {
		if (gcry_mpi_scan(&mpi_e, GCRYMPI_FMT_USG,
				keys[i].e, keys[i].len_e, NULL) ||
		    gcry_mpi_scan(&mpi_n, GCRYMPI_FMT_USG,
				keys[i].n, keys[i].len_n, NULL)) {
			fprintf(stderr, "Failed to convert numbers.\n");
			goto out;
		}

		if (gcry_sexp_build(&rsa, NULL,
				    "(public-key (rsa (n %m) (e %m)))",
				    mpi_n, mpi_e)) {
			fprintf(stderr, "Failed to build RSA S-expression.\n");
			gcry_mpi_release(mpi_e);
			gcry_mpi_release(mpi_n);
			goto out;
		}

		ok = gcry_pk_verify(signature, data, rsa) == 0;
		gcry_mpi_release(mpi_e);
		gcry_mpi_release(mpi_n);
		gcry_sexp_release(rsa);
	}

	if (!ok)
		fprintf(stderr, "Database signature verification failed.\n");

out:
	gcry_sexp_release(data);
	gcry_sexp_release(signature);
	return ok;
}
#endif /* USE_GCRYPT */

#if !defined(USE_OPENSSL) && !defined(USE_GCRYPT)
int reglib_verify_db_signature(uint8_t *db, size_t dblen, size_t siglen)
{
	return 1;
}
#endif

const struct reglib_regdb_ctx *reglib_malloc_regdb_ctx(const char *regdb_file)
{
	struct regdb_file_header *header;
	struct reglib_regdb_ctx *ctx;

	ctx = malloc(sizeof(struct reglib_regdb_ctx));
	if (!ctx)
		return NULL;

	memset(ctx, 0, sizeof(struct reglib_regdb_ctx));

	ctx->fd = open(regdb_file, O_RDONLY);

	if (ctx->fd < 0) {
		free(ctx);
		return NULL;
	}

	if (fstat(ctx->fd, &ctx->stat)) {
		close(ctx->fd);
		free(ctx);
		return NULL;
	}

	ctx->real_dblen = ctx->stat.st_size;

	ctx->db = mmap(NULL, ctx->real_dblen, PROT_READ,
		       MAP_PRIVATE, ctx->fd, 0);
	if (ctx->db == MAP_FAILED) {
		close(ctx->fd);
		free(ctx);
		return NULL;
	}

	ctx->header = reglib_get_file_ptr(ctx->db, ctx->real_dblen,
					  sizeof(struct regdb_file_header),
					  0);
	header = ctx->header;

	if (ntohl(header->magic) != REGDB_MAGIC)
		goto err_out;

	if (ntohl(header->version) != REGDB_VERSION)
		goto err_out;

	ctx->siglen = ntohl(header->signature_length);

	if (ctx->siglen > ctx->real_dblen - sizeof(*header))
		goto err_out;

	/* The actual dblen does not take into account the signature */
	ctx->dblen = ctx->real_dblen - ctx->siglen;

	/* verify signature */
	if (!reglib_verify_db_signature(ctx->db, ctx->dblen, ctx->siglen))
		goto err_out;

	ctx->verified = true;
	ctx->num_countries = ntohl(header->reg_country_num);
	ctx->countries = reglib_get_file_ptr(ctx->db,
					     ctx->dblen,
					     sizeof(struct regdb_file_reg_country) * ctx->num_countries,
					     header->reg_country_ptr);
	return ctx;

err_out:
	close(ctx->fd);
	munmap(ctx->db, ctx->real_dblen);
	free(ctx);
	return NULL;
}

void reglib_free_regdb_ctx(const struct reglib_regdb_ctx *regdb_ctx)
{
	struct reglib_regdb_ctx *ctx;

	if (!regdb_ctx)
		return;

	ctx = (struct reglib_regdb_ctx *) regdb_ctx;

	memset(ctx, 0, sizeof(struct reglib_regdb_ctx));
	close(ctx->fd);
	munmap(ctx->db, ctx->real_dblen);
	free(ctx);
}

static void reg_rule2rd(uint8_t *db, size_t dblen,
	uint32_t ruleptr, struct ieee80211_reg_rule *rd_reg_rule)
{
	struct regdb_file_reg_rule *rule;
	struct regdb_file_freq_range *freq;
	struct regdb_file_power_rule *power;

	struct ieee80211_freq_range *rd_freq_range = &rd_reg_rule->freq_range;
	struct ieee80211_power_rule *rd_power_rule = &rd_reg_rule->power_rule;

	rule  = reglib_get_file_ptr(db, dblen, sizeof(*rule), ruleptr);
	freq  = reglib_get_file_ptr(db, dblen, sizeof(*freq), rule->freq_range_ptr);
	power = reglib_get_file_ptr(db, dblen, sizeof(*power), rule->power_rule_ptr);

	rd_freq_range->start_freq_khz = ntohl(freq->start_freq);
	rd_freq_range->end_freq_khz = ntohl(freq->end_freq);
	rd_freq_range->max_bandwidth_khz = ntohl(freq->max_bandwidth);

	rd_power_rule->max_antenna_gain = ntohl(power->max_antenna_gain);
	rd_power_rule->max_eirp = ntohl(power->max_eirp);

	rd_reg_rule->flags = ntohl(rule->flags);

	if (rd_reg_rule->flags & RRF_NO_IR_ALL)
		rd_reg_rule->flags |= RRF_NO_IR_ALL;
}

/* Converts a file regdomain to ieee80211_regdomain, easier to manage */
const static struct ieee80211_regdomain *
country2rd(const struct reglib_regdb_ctx *ctx,
	   struct regdb_file_reg_country *country)
{
	struct regdb_file_reg_rules_collection *rcoll;
	struct ieee80211_regdomain *rd;
	unsigned int i, num_rules;
	size_t size_of_rd;

	rcoll = reglib_get_file_ptr(ctx->db, ctx->dblen, sizeof(*rcoll),
				    country->reg_collection_ptr);
	num_rules = ntohl(rcoll->reg_rule_num);
	/* re-get pointer with sanity checking for num_rules */
	rcoll = reglib_get_file_ptr(ctx->db, ctx->dblen,
				    reglib_array_len(sizeof(*rcoll), num_rules,
						     sizeof(uint32_t)),
				    country->reg_collection_ptr);

	size_of_rd = reglib_array_len(sizeof(struct ieee80211_regdomain),
				      num_rules,
				      sizeof(struct ieee80211_reg_rule));

	rd = malloc(size_of_rd);
	if (!rd)
		return NULL;

	memset(rd, 0, size_of_rd);

	rd->alpha2[0] = country->alpha2[0];
	rd->alpha2[1] = country->alpha2[1];
	rd->dfs_region = country->creqs & 0x3;
	rd->n_reg_rules = num_rules;

	for (i = 0; i < num_rules; i++) {
		reg_rule2rd(ctx->db, ctx->dblen, rcoll->reg_rule_ptrs[i],
			&rd->reg_rules[i]);
	}

	return rd;
}

const struct ieee80211_regdomain *
reglib_get_rd_idx(unsigned int idx, const struct reglib_regdb_ctx *ctx)
{
	struct regdb_file_reg_country *country;

	if (!ctx)
		return NULL;

	if (idx >= ctx->num_countries)
		return NULL;

	country = ctx->countries + idx;

	return country2rd(ctx, country);
}

const struct ieee80211_regdomain *
reglib_get_rd_alpha2(const char *alpha2, const char *file)
{
	const struct reglib_regdb_ctx *ctx;
	const struct ieee80211_regdomain *rd = NULL;
	struct regdb_file_reg_country *country;
	bool found_country = false;
	unsigned int i;

	ctx = reglib_malloc_regdb_ctx(file);
	if (!ctx)
		return NULL;

	for (i = 0; i < ctx->num_countries; i++) {
		country = ctx->countries + i;
		if (memcmp(country->alpha2, alpha2, 2) == 0) {
			found_country = 1;
			break;
		}
	}

	if (!found_country)
		goto out;

	rd = country2rd(ctx, country);
	if (!rd)
		goto out;

out:
	reglib_free_regdb_ctx(ctx);
	return rd;
}

/* Sanity check on a regulatory rule */
static int is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
{
	const struct ieee80211_freq_range *freq_range = &rule->freq_range;
	uint32_t freq_diff;

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

	if (freq_range->start_freq_khz > freq_range->end_freq_khz)
		return 0;

	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 0;

	return 1;
}

int reglib_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 0;

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		if (!is_valid_reg_rule(reg_rule))
			return 0;
	}
	return 1;
}

static int reg_rules_union(const struct ieee80211_reg_rule *rule1,
			   const struct ieee80211_reg_rule *rule2,
			   struct ieee80211_reg_rule *union_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;

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

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


	if (freq_range1->end_freq_khz < freq_range2->start_freq_khz)
		return -EINVAL;
	if (freq_range2->end_freq_khz < freq_range1->start_freq_khz)
		return -EINVAL;

	freq_range->start_freq_khz = reglib_min(freq_range1->start_freq_khz,
					 freq_range2->start_freq_khz);
	freq_range->end_freq_khz = reglib_max(freq_range1->end_freq_khz,
				       freq_range2->end_freq_khz);
	freq_range->max_bandwidth_khz = reglib_max(freq_range1->max_bandwidth_khz,
					    freq_range2->max_bandwidth_khz);

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

	union_rule->flags = rule1->flags | rule2->flags;

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

	return 0;
}

/*
 * Helper for reglib_intersect_rds(), 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;
	uint32_t 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 = reglib_max(freq_range1->start_freq_khz,
					 freq_range2->start_freq_khz);
	freq_range->end_freq_khz = reglib_min(freq_range1->end_freq_khz,
				       freq_range2->end_freq_khz);
	freq_range->max_bandwidth_khz = reglib_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 = reglib_min(power_rule1->max_eirp,
		power_rule2->max_eirp);
	power_rule->max_antenna_gain = reglib_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;
}

/**
 * reglib_intersect_rds - 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
 * malloc() this structure for you.
 */
struct ieee80211_regdomain *
reglib_intersect_rds(const struct ieee80211_regdomain *rd1,
		     const struct ieee80211_regdomain *rd2)
{
	int r;
	size_t 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 = reglib_array_len(sizeof(struct ieee80211_regdomain),
					num_rules + 1,
					sizeof(struct ieee80211_reg_rule));

	rd = malloc(size_of_regd);
	if (!rd)
		return NULL;

	memset(rd, 0, size_of_regd);

	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);
			if (r)
				continue;
			rule_idx++;
		}
	}

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

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

	return rd;
}

const struct ieee80211_regdomain *
reglib_intersect_regdb(const struct reglib_regdb_ctx *ctx)
{
	const struct ieee80211_regdomain *rd;
	struct ieee80211_regdomain *prev_rd_intsct = NULL, *rd_intsct = NULL;
	int intersected = 0;
	unsigned int idx = 0;

	if (!ctx)
		return NULL;

	reglib_for_each_country(rd, idx, ctx) {
		if (reglib_is_world_regdom((const char *) rd->alpha2)) {
			free((struct ieee80211_regdomain *) rd);
			continue;
		}

		if (!prev_rd_intsct) {
			prev_rd_intsct = (struct ieee80211_regdomain *) rd;
			continue;
		}

		if (rd_intsct) {
			free(prev_rd_intsct);
			prev_rd_intsct = (struct ieee80211_regdomain *) rd_intsct;
		}

		rd_intsct = reglib_intersect_rds(prev_rd_intsct, rd);
		if (!rd_intsct) {
			free(prev_rd_intsct);
			free((struct ieee80211_regdomain *) rd);
			return NULL;
		}

		intersected++;
		free((struct ieee80211_regdomain *) rd);
	}

	if (!idx)
		return NULL;

	if (intersected <= 0) {
		rd_intsct = prev_rd_intsct;
		prev_rd_intsct = NULL;
		if (idx > 1) {
			free(rd_intsct);
			return NULL;
		}
	}

	if (prev_rd_intsct)
		free(prev_rd_intsct);

	return rd_intsct;
}

static const char *dfs_domain_name(enum regdb_dfs_regions region)
{
	switch (region) {
	case REGDB_DFS_UNSET:
		return "DFS-UNSET";
	case REGDB_DFS_FCC:
		return "DFS-FCC";
	case REGDB_DFS_ETSI:
		return "DFS-ETSI";
	case REGDB_DFS_JP:
		return "DFS-JP";
	default:
		return "DFS-invalid";
	}
}

static void print_reg_rule(const struct ieee80211_reg_rule *rule)
{
	const struct ieee80211_freq_range *freq;
	const struct ieee80211_power_rule *power;

	freq  = &rule->freq_range;
	power = &rule->power_rule;

	printf("\t(%.3f - %.3f @ %.3f), ",
	       ((float)(freq->start_freq_khz))/1000.0,
	       ((float)(freq->end_freq_khz))/1000.0,
	       ((float)(freq->max_bandwidth_khz))/1000.0);

	printf("(");

	if (power->max_eirp)
		printf("%.2f)", ((float)(power->max_eirp)/100.0));
	else
		printf("N/A)");

	if (rule->dfs_cac_ms)
		printf(", (%u)", rule->dfs_cac_ms);
	else
		printf(", (N/A)");

	if (rule->flags & RRF_NO_OFDM)
		printf(", NO-OFDM");
	if (rule->flags & RRF_NO_CCK)
		printf(", NO-CCK");
	if (rule->flags & RRF_NO_INDOOR)
		printf(", NO-INDOOR");
	if (rule->flags & RRF_NO_OUTDOOR)
		printf(", NO-OUTDOOR");
	if (rule->flags & RRF_DFS)
		printf(", DFS");
	if (rule->flags & RRF_PTP_ONLY)
		printf(", PTP-ONLY");
	if (rule->flags & RRF_PTMP_ONLY)
		printf(", PTMP-ONLY");
	if (rule->flags & RRF_NO_IR_ALL)
		printf(", NO-IR");
	if (rule->flags & RRF_AUTO_BW)
		printf(", AUTO-BW");

	printf("\n");
}

void reglib_print_regdom(const struct ieee80211_regdomain *rd)
{
	unsigned int i;
	printf("country %.2s: %s\n", rd->alpha2,
	       dfs_domain_name(rd->dfs_region));
	for (i = 0; i < rd->n_reg_rules; i++)
		print_reg_rule(&rd->reg_rules[i]);
	printf("\n");
}

static unsigned int reglib_parse_dfs_region(char *dfs_region)
{
	if (!dfs_region)
		return REGDB_DFS_UNSET;

	if (strstr(dfs_region, "DFS-FCC"))
		return REGDB_DFS_FCC;
	if (strstr(dfs_region, "DFS-ETSI"))
		return REGDB_DFS_ETSI;
	if (strstr(dfs_region, "DFS-JP"))
		return REGDB_DFS_JP;
	return REGDB_DFS_UNSET;
}

static uint32_t reglib_parse_rule_flag(char *flag_s)
{
	uint32_t flags = 0;

	if (strstr(flag_s, "NO-OFDM"))
		flags |= RRF_NO_OFDM;
	if (strstr(flag_s, "NO-CCK"))
		flags |= RRF_NO_CCK;
	if (strstr(flag_s, "NO-INDOOR"))
		flags |= RRF_NO_INDOOR;
	if (strstr(flag_s, "NO-OUTDOOR"))
		flags |= RRF_NO_OUTDOOR;
	if (strstr(flag_s, "DFS"))
		flags |= RRF_DFS;
	if (strstr(flag_s, "PTP-ONLY"))
		flags |= RRF_PTP_ONLY;
	if (strstr(flag_s, "PTMP-ONLY"))
		flags |= RRF_PTMP_ONLY;
	if (strstr(flag_s, "NO-IR"))
		flags |= RRF_NO_IR;
	if (strstr(flag_s, "AUTO-BW"))
		flags |= RRF_AUTO_BW;

	return flags;
}

static int reglib_parse_rule(FILE *fp, struct ieee80211_reg_rule *reg_rule)
{
	char line[1024];
	char *line_p;
	int hits, r = 0;
	float start_freq_khz, end_freq_khz, max_bandwidth_khz, max_eirp;
	unsigned int dfs_cac_ms = 0;

	memset(line, 0, sizeof(line));
	line_p = fgets(line, sizeof(line), fp);
	if (line_p != line)
		return -EINVAL;

	/* First get start, end and bandwidth */
	hits = sscanf(line_p, "\t(%f - %f @ %f),",
		      &start_freq_khz,
		      &end_freq_khz,
		      &max_bandwidth_khz);

	if (hits != 3)
		return -EINVAL;

	reg_rule->freq_range.start_freq_khz =
		REGLIB_MHZ_TO_KHZ(start_freq_khz);
	reg_rule->freq_range.end_freq_khz =
		REGLIB_MHZ_TO_KHZ(end_freq_khz);
	reg_rule->freq_range.max_bandwidth_khz =
		REGLIB_MHZ_TO_KHZ(max_bandwidth_khz);

	/* Next get eirp */
	strsep(&line_p, ",");
	if (!line_p) {
		fprintf(stderr, "not found eirp in line: %s\n", line);
		return -EINVAL;
	}

	if (strstr(line_p, "mW")) {
		hits = sscanf(line_p, " (%f mW)", &max_eirp);
		if (hits != 1)
			return -EINVAL;
		reg_rule->power_rule.max_eirp =
			REGLIB_MW_TO_MBM(max_eirp);
	} else {
		hits = sscanf(line_p, " (%f)", &max_eirp);
		if (hits != 1)
			return -EINVAL;
		reg_rule->power_rule.max_eirp =
			REGLIB_DBM_TO_MBM(max_eirp);
	}

	/* Next get optional arguments (flags ...) */
	strsep(&line_p, ",");
	if (line_p) {
		/* Check DFS CAC time */
		hits = sscanf(line_p, " (%u)", &dfs_cac_ms);
		if (hits == 1)
			reg_rule->dfs_cac_ms = dfs_cac_ms;

		/* Check flags */
		reg_rule->flags = reglib_parse_rule_flag(line_p);
	}

	return r;
}

static uint32_t
reglib_get_n_rules(FILE *fp, struct ieee80211_reg_rule *reg_rule)
{
	uint32_t n_rules = 0;
	int r;
	bool save_debug = false;

	save_debug = debug;
	debug = false;

	while (1) {
		r = reglib_parse_rule(fp, reg_rule);
		if (r != 0)
			break;
		n_rules++;
	}

	debug = save_debug;

	return n_rules;
}

static int reglib_parse_reg_rule(FILE *fp, struct ieee80211_reg_rule *reg_rule)
{
	int r;

	while (1) {
		r = reglib_parse_rule(fp, reg_rule);
		if (r != 0)
			continue;
		return 0;
	}
}

static struct ieee80211_regdomain *
reglib_parse_rules(FILE *fp, struct ieee80211_regdomain *trd)
{
	struct ieee80211_regdomain *rd;
	struct ieee80211_reg_rule rule;
	struct ieee80211_reg_rule *reg_rule;
	fpos_t pos;
	unsigned int i;
	uint32_t size_of_regd = 0, num_rules = 0;
	int r;

	memset(&rule, 0, sizeof(rule));
	reg_rule = &rule;

	r = fgetpos(fp, &pos);
	if (r != 0) {
		fprintf(stderr, "fgetpos() failed: %s\n",
			strerror(errno));
		return NULL;
	}

	num_rules = reglib_get_n_rules(fp, reg_rule);
	if (!num_rules)
		return NULL;

	size_of_regd = reglib_array_len(sizeof(struct ieee80211_regdomain),
					num_rules + 1,
					sizeof(struct ieee80211_reg_rule));
	rd = malloc(size_of_regd);
	if (!rd)
		return NULL;

	memset(rd, 0, size_of_regd);
	memcpy(rd, trd, sizeof(*trd));

	rd->n_reg_rules = num_rules;

	r = fsetpos(fp, &pos);
	if (r != 0) {
		fprintf(stderr, "fsetpos() failed: %s\n",
			strerror(errno));
		free(rd);
		return NULL;
	}
	for (i = 0; i < num_rules; i++) {
		struct ieee80211_reg_rule *rrule = &rd->reg_rules[i];

		if (reglib_parse_reg_rule(fp, rrule) != 0) {
			fprintf(stderr, "rule parse failed\n");
			free(rd);
			return NULL;
		}
	}
	return rd;
}

static int reglib_parse_country_dfs(char *line, struct ieee80211_regdomain *rd)
{
	char dfs_region_alpha[9];
	char alpha2[2];
	int hits;

	memset(rd, 0, sizeof(*rd));
	memset(alpha2, 0, sizeof(alpha2));
	memset(dfs_region_alpha, 0, sizeof(dfs_region_alpha));

	hits = sscanf(line, "country %2[a-zA-Z0-9]:%*[ ]%s\n",
		      alpha2,
		      dfs_region_alpha);
	if (hits <= 0)
		return -EINVAL;

	rd->alpha2[0] = alpha2[0];
	rd->alpha2[1] = alpha2[1];
	rd->dfs_region = reglib_parse_dfs_region(dfs_region_alpha);

	return 0;
}

struct ieee80211_regdomain *__reglib_parse_country(FILE *fp)
{
	struct ieee80211_regdomain *rd;
	struct ieee80211_regdomain tmp_rd;
	char line[1024];
	char *line_p;
	int r = 0;

	memset(&tmp_rd, 0, sizeof(tmp_rd));
	memset(line, 0, sizeof(line));

	line_p = fgets(line, sizeof(line), fp);

	if (line_p != line) {
		return NULL;
	}

	/* Country */
	r = reglib_parse_country_dfs(line_p, &tmp_rd);
	if (r != 0) {
		fprintf(stderr, "Invalid country line: %s", line);
		return NULL;
	}

	/* Rules */
	rd = reglib_parse_rules(fp, &tmp_rd);

	return rd;
}

static int reglib_find_next_country_stream(FILE *fp)
{
	fpos_t prev_pos;
	int r;
	unsigned int i = 0;

	while(1) {
		char line[1024];
		char *line_p;

		r = fgetpos(fp, &prev_pos);
		if (r != 0) {
			fprintf(stderr, "fgetpos() failed: %s\n",
				strerror(errno));
			return r;
		}

		memset(line, 0, sizeof(line));

		line_p = fgets(line, sizeof(line), fp);
		if (line_p == line) {
			if (strspn(line, "\n") == strlen(line)) {
				i++;
				continue;
			}
			if (strncmp(line, "country", 7) != 0)
				continue;
			r = fsetpos(fp, &prev_pos);
			if (r != 0) {
				fprintf(stderr, "fsetpos() failed: %s\n",
					strerror(errno));
				return r;
			}
			return 0;
		} else
			return EOF;
	}
}

struct ieee80211_regdomain *reglib_parse_country(FILE *fp)
{
	int r;

	r = reglib_find_next_country_stream(fp);
	if (r != 0)
		return NULL;
	return __reglib_parse_country(fp);
}

FILE *reglib_create_parse_stream(FILE *f)
{
	unsigned int lines = 0;
	FILE *fp;

	fp = tmpfile();
	if (errno) {
		fprintf(stderr, "%s\n", strerror(errno));
		return NULL;
	}

	while(1) {
		char line[1024];
		char *line_p;

		line_p = fgets(line, sizeof(line), f);
		if (line_p == line) {
			if (strchr(line, '#') == NULL) {
				fputs(line, fp);
				lines++;
			}
			continue;
		} else
			break;
	}

	rewind(fp);
	fflush(fp);

	return fp;
}

/*
 * Just whatever for now, nothing formal, but note that as bands
 * grow we'll want to make this a bit more formal somehow.
 */
static uint32_t reglib_deduce_band(uint32_t start_freq_khz)
{
	uint32_t freq_mhz = REGLIB_KHZ_TO_MHZ(start_freq_khz);

	if (freq_mhz >= 4000)
		return 5;
	if (freq_mhz > 2000 && freq_mhz < 4000)
		return 2;
	if (freq_mhz > 50000)
		return 60;
	return 1234;
}

/*
 * The idea behind a rule key is that if two rule keys share the
 * same key they can be merged together if their frequencies overlap.
 */
static uint64_t reglib_rule_key(struct ieee80211_reg_rule *reg_rule)
{
	struct ieee80211_power_rule *power_rule;
	struct ieee80211_freq_range *freq_range;
	uint32_t band;
	uint32_t key;

	freq_range = &reg_rule->freq_range;
	band = reglib_deduce_band(freq_range->start_freq_khz);

	power_rule = &reg_rule->power_rule;

	key = ((power_rule->max_eirp ^  0) <<  0) ^
	      ((reg_rule->flags      ^  8) <<  8) ^
	      ((band                 ^ 16) << 16);

	return key;
}

struct reglib_optimize_map {
	bool optimized;
	uint32_t key;
};

/* Does the provided rule suffice both of the other two */
static int reglib_opt_rule_fit(struct ieee80211_reg_rule *rule1,
			       struct ieee80211_reg_rule *rule2,
			       struct ieee80211_reg_rule *opt_rule)
{
	struct ieee80211_reg_rule interesected_rule;
	struct ieee80211_reg_rule *int_rule;
	int r;

	memset(&interesected_rule, 0, sizeof(struct ieee80211_reg_rule));
	int_rule = &interesected_rule;

	r = reg_rules_intersect(rule1, opt_rule, int_rule);
	if (r != 0)
		return r;
	r = reg_rules_intersect(rule2, opt_rule, int_rule);
	if (r != 0)
		return r;

	return 0;
}

static int reg_rule_optimize(struct ieee80211_reg_rule *rule1,
			     struct ieee80211_reg_rule *rule2,
			     struct ieee80211_reg_rule *opt_rule)
{
	int r;

	r = reg_rules_union(rule1, rule2, opt_rule);
	if (r != 0)
		return r;
	r = reglib_opt_rule_fit(rule1, rule2, opt_rule);
	if (r != 0)
		return r;

	return 0;
}

/*
 * Here's the math explanation:
 *
 * This takes each pivot frequency on the regulatory domain, computes
 * the union between it each regulatory rule on the regulatory domain
 * sequentially, and after that it tries to verify that the pivot frequency
 * fits on it by computing an intersection between it and the union, if
 * a rule exist as a possible intersection then we know the rule can be
 * subset of the combination of the two frequency ranges (union) computed.
 */
static unsigned int reg_rule_optimize_rd(struct ieee80211_regdomain *rd,
					 unsigned int rule_idx,
					 struct ieee80211_reg_rule *opt_rule,
					 struct reglib_optimize_map *opt_map)
{
	unsigned int i;
	struct ieee80211_reg_rule *rule1;
	struct ieee80211_reg_rule *rule2;

	struct ieee80211_reg_rule tmp_optimized_rule;
	struct ieee80211_reg_rule *tmp_opt_rule;

	struct ieee80211_reg_rule *target_rule;

	unsigned int optimized = 0;
	int r;

	if (rule_idx > rd->n_reg_rules)
		return 0;

	rule1 = &rd->reg_rules[rule_idx];

	memset(&tmp_optimized_rule, 0, sizeof(struct ieee80211_reg_rule));
	tmp_opt_rule = &tmp_optimized_rule;

	memset(opt_rule, 0, sizeof(*opt_rule));

	for (i = 0; i < rd->n_reg_rules; i++) {
		if (rule_idx == i)
			continue;
		rule2 = &rd->reg_rules[i];
		if (opt_map[rule_idx].key != opt_map[i].key)
			continue;

		target_rule = optimized ? opt_rule : rule1;
		r = reg_rule_optimize(target_rule, rule2, tmp_opt_rule);
		if (r != 0)
			continue;
		memcpy(opt_rule, tmp_opt_rule, sizeof(*tmp_opt_rule));

		if (!opt_map[i].optimized) {
			opt_map[i].optimized = true;
			optimized++;
		}
		if (!opt_map[rule_idx].optimized) {
			opt_map[rule_idx].optimized = true;
			optimized++;
		}
	}
	return optimized;
}

struct ieee80211_regdomain *
reglib_optimize_regdom(struct ieee80211_regdomain *rd)
{
	struct ieee80211_regdomain *opt_rd = NULL;
	struct ieee80211_reg_rule *reg_rule;
	struct ieee80211_reg_rule *reg_rule_dst;
	struct ieee80211_reg_rule optimized_reg_rule;
	struct ieee80211_reg_rule *opt_reg_rule;
	struct reglib_optimize_map *opt_map;
	unsigned int i, idx = 0, non_opt = 0, opt = 0;
	size_t num_rules, size_of_regd, size_of_opt_map;
	unsigned int num_opts = 0;

	size_of_opt_map = (rd->n_reg_rules + 2) *
		sizeof(struct reglib_optimize_map);
	opt_map = malloc(size_of_opt_map);
	if (!opt_map)
		return NULL;

	memset(opt_map, 0, size_of_opt_map);
	memset(&optimized_reg_rule, 0, sizeof(struct ieee80211_reg_rule));

	opt_reg_rule = &optimized_reg_rule;

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		opt_map[i].key = reglib_rule_key(reg_rule);
	}
	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		if (opt_map[i].optimized)
			continue;
		num_opts = reg_rule_optimize_rd(rd, i, opt_reg_rule, opt_map);
		if (!num_opts)
			non_opt++;
		else
			opt += (num_opts ? 1 : 0);
	}

	num_rules = non_opt + opt;

	if (num_rules > rd->n_reg_rules)
		goto fail_opt_map;

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

	opt_rd = malloc(size_of_regd);
	if (!opt_rd)
		goto fail_opt_map;
	memset(opt_rd, 0, size_of_regd);

	opt_rd->n_reg_rules = num_rules;
	opt_rd->alpha2[0] = rd->alpha2[0];
	opt_rd->alpha2[1] = rd->alpha2[1];
	opt_rd->dfs_region = rd->dfs_region;

	memset(opt_map, 0, size_of_opt_map);
	memset(&optimized_reg_rule, 0, sizeof(struct ieee80211_reg_rule));

	opt_reg_rule = &optimized_reg_rule;

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		opt_map[i].key = reglib_rule_key(reg_rule);
	}

	for (i = 0; i < rd->n_reg_rules; i++) {
		reg_rule = &rd->reg_rules[i];
		reg_rule_dst = &opt_rd->reg_rules[idx];
		if (opt_map[i].optimized)
			continue;
		num_opts = reg_rule_optimize_rd(rd, i, opt_reg_rule, opt_map);
		if (!num_opts)
			memcpy(reg_rule_dst, reg_rule, sizeof(struct ieee80211_reg_rule));
		else
			memcpy(reg_rule_dst, opt_reg_rule, sizeof(struct ieee80211_reg_rule));
		idx++;
	}

	if (idx != num_rules)
		goto fail;

	for (i = 0; i < opt_rd->n_reg_rules; i++) {
		reg_rule = &opt_rd->reg_rules[i];
		if (!is_valid_reg_rule(reg_rule))
			goto fail;
	}

	free(opt_map);
	return opt_rd;
fail:
	free(opt_rd);
fail_opt_map:
	free(opt_map);
	return NULL;
}