summaryrefslogtreecommitdiffstats
path: root/libxtables/xtoptions.c
blob: d26d2f8b3d65d5d1aab0473d53850c75f27235fc (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
/*
 *	Argument parser
 *	Copyright © Jan Engelhardt, 2011
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation; either version 2 of
 *	the License, or (at your option) any later version.
 */
#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include "xtables.h"
#include "xshared.h"
#ifndef IPTOS_NORMALSVC
#	define IPTOS_NORMALSVC 0
#endif

#define XTOPT_MKPTR(cb) \
	((void *)((char *)(cb)->data + (cb)->entry->ptroff))

/**
 * Simple key-value pairs for syslog levels
 */
struct syslog_level {
	char name[8];
	uint8_t level;
};

struct tos_value_mask {
	uint8_t value, mask;
};

static const size_t xtopt_psize[] = {
	/*
	 * All types not listed here, and thus essentially being initialized to
	 * zero have zero on purpose.
	 */
	[XTTYPE_UINT8]       = sizeof(uint8_t),
	[XTTYPE_UINT16]      = sizeof(uint16_t),
	[XTTYPE_UINT32]      = sizeof(uint32_t),
	[XTTYPE_UINT64]      = sizeof(uint64_t),
	[XTTYPE_UINT8RC]     = sizeof(uint8_t[2]),
	[XTTYPE_UINT16RC]    = sizeof(uint16_t[2]),
	[XTTYPE_UINT32RC]    = sizeof(uint32_t[2]),
	[XTTYPE_UINT64RC]    = sizeof(uint64_t[2]),
	[XTTYPE_DOUBLE]      = sizeof(double),
	[XTTYPE_STRING]      = -1,
	[XTTYPE_SYSLOGLEVEL] = sizeof(uint8_t),
	[XTTYPE_HOST]        = sizeof(union nf_inet_addr),
	[XTTYPE_HOSTMASK]    = sizeof(union nf_inet_addr),
	[XTTYPE_PROTOCOL]    = sizeof(uint8_t),
	[XTTYPE_PORT]        = sizeof(uint16_t),
	[XTTYPE_PORTRC]      = sizeof(uint16_t[2]),
	[XTTYPE_PLENMASK]    = sizeof(union nf_inet_addr),
	[XTTYPE_ETHERMAC]    = sizeof(uint8_t[6]),
};

/**
 * Creates getopt options from the x6-style option map, and assigns each a
 * getopt id.
 */
struct option *
xtables_options_xfrm(struct option *orig_opts, struct option *oldopts,
		     const struct xt_option_entry *entry, unsigned int *offset)
{
	unsigned int num_orig, num_old = 0, num_new, i;
	struct option *merge, *mp;

	if (entry == NULL)
		return oldopts;
	for (num_orig = 0; orig_opts[num_orig].name != NULL; ++num_orig)
		;
	if (oldopts != NULL)
		for (num_old = 0; oldopts[num_old].name != NULL; ++num_old)
			;
	for (num_new = 0; entry[num_new].name != NULL; ++num_new)
		;

	/*
	 * Since @oldopts also has @orig_opts already (and does so at the
	 * start), skip these entries.
	 */
	oldopts += num_orig;
	num_old -= num_orig;

	merge = malloc(sizeof(*mp) * (num_orig + num_old + num_new + 1));
	if (merge == NULL)
		return NULL;

	/* Let the base options -[ADI...] have precedence over everything */
	memcpy(merge, orig_opts, sizeof(*mp) * num_orig);
	mp = merge + num_orig;

	/* Second, the new options */
	xt_params->option_offset += XT_OPTION_OFFSET_SCALE;
	*offset = xt_params->option_offset;

	for (i = 0; i < num_new; ++i, ++mp, ++entry) {
		mp->name         = entry->name;
		mp->has_arg      = entry->type != XTTYPE_NONE;
		mp->flag         = NULL;
		mp->val          = entry->id + *offset;
	}

	/* Third, the old options */
	memcpy(mp, oldopts, sizeof(*mp) * num_old);
	mp += num_old;
	xtables_free_opts(0);

	/* Clear trailing entry */
	memset(mp, 0, sizeof(*mp));
	return merge;
}

/**
 * Give the upper limit for a certain type.
 */
static uintmax_t xtopt_max_by_type(enum xt_option_type type)
{
	switch (type) {
	case XTTYPE_UINT8:
	case XTTYPE_UINT8RC:
		return UINT8_MAX;
	case XTTYPE_UINT16:
	case XTTYPE_UINT16RC:
		return UINT16_MAX;
	case XTTYPE_UINT32:
	case XTTYPE_UINT32RC:
		return UINT32_MAX;
	case XTTYPE_UINT64:
	case XTTYPE_UINT64RC:
		return UINT64_MAX;
	default:
		return 0;
	}
}

/**
 * Return the size of a single entity based upon a type - predominantly an
 * XTTYPE_UINT*RC type.
 */
static size_t xtopt_esize_by_type(enum xt_option_type type)
{
	switch (type) {
	case XTTYPE_UINT8RC:
		return xtopt_psize[XTTYPE_UINT8];
	case XTTYPE_UINT16RC:
		return xtopt_psize[XTTYPE_UINT16];
	case XTTYPE_UINT32RC:
		return xtopt_psize[XTTYPE_UINT32];
	case XTTYPE_UINT64RC:
		return xtopt_psize[XTTYPE_UINT64];
	default:
		return xtopt_psize[type];
	}
}

/**
 * Require a simple integer.
 */
static void xtopt_parse_int(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	uintmax_t lmin = 0, lmax = xtopt_max_by_type(entry->type);
	uintmax_t value;

	if (cb->entry->min != 0)
		lmin = cb->entry->min;
	if (cb->entry->max != 0)
		lmax = cb->entry->max;

	if (!xtables_strtoul(cb->arg, NULL, &value, lmin, lmax))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: bad value for option \"--%s\", "
			"or out of range (%ju-%ju).\n",
			cb->ext_name, entry->name, lmin, lmax);

	if (entry->type == XTTYPE_UINT8) {
		cb->val.u8 = value;
		if (entry->flags & XTOPT_PUT)
			*(uint8_t *)XTOPT_MKPTR(cb) = cb->val.u8;
	} else if (entry->type == XTTYPE_UINT16) {
		cb->val.u16 = value;
		if (entry->flags & XTOPT_PUT)
			*(uint16_t *)XTOPT_MKPTR(cb) = cb->val.u16;
	} else if (entry->type == XTTYPE_UINT32) {
		cb->val.u32 = value;
		if (entry->flags & XTOPT_PUT)
			*(uint32_t *)XTOPT_MKPTR(cb) = cb->val.u32;
	} else if (entry->type == XTTYPE_UINT64) {
		cb->val.u64 = value;
		if (entry->flags & XTOPT_PUT)
			*(uint64_t *)XTOPT_MKPTR(cb) = cb->val.u64;
	}
}

/**
 * Require a simple floating point number.
 */
static void xtopt_parse_float(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	double value;
	char *end;

	value = strtod(cb->arg, &end);
	if (end == cb->arg || *end != '\0' ||
	    (entry->min != entry->max &&
	    (value < entry->min || value > entry->max)))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: bad value for option \"--%s\", "
			"or out of range (%u-%u).\n",
			cb->ext_name, entry->name, entry->min, entry->max);

	cb->val.dbl = value;
	if (entry->flags & XTOPT_PUT)
		*(double *)XTOPT_MKPTR(cb) = cb->val.dbl;
}

/**
 * Copy the parsed value to the appropriate entry in cb->val.
 */
static void xtopt_mint_value_to_cb(struct xt_option_call *cb, uintmax_t value)
{
	const struct xt_option_entry *entry = cb->entry;

	if (cb->nvals >= ARRAY_SIZE(cb->val.u32_range))
		return;
	if (entry->type == XTTYPE_UINT8RC)
		cb->val.u8_range[cb->nvals] = value;
	else if (entry->type == XTTYPE_UINT16RC)
		cb->val.u16_range[cb->nvals] = value;
	else if (entry->type == XTTYPE_UINT32RC)
		cb->val.u32_range[cb->nvals] = value;
	else if (entry->type == XTTYPE_UINT64RC)
		cb->val.u64_range[cb->nvals] = value;
}

/**
 * Copy the parsed value to the data area, using appropriate type access.
 */
static void xtopt_mint_value_to_ptr(struct xt_option_call *cb, void **datap,
				    uintmax_t value)
{
	const struct xt_option_entry *entry = cb->entry;
	void *data = *datap;

	if (!(entry->flags & XTOPT_PUT))
		return;
	if (entry->type == XTTYPE_UINT8RC)
		*(uint8_t *)data = value;
	else if (entry->type == XTTYPE_UINT16RC)
		*(uint16_t *)data = value;
	else if (entry->type == XTTYPE_UINT32RC)
		*(uint32_t *)data = value;
	else if (entry->type == XTTYPE_UINT64RC)
		*(uint64_t *)data = value;
	data += xtopt_esize_by_type(entry->type);
	*datap = data;
}

/**
 * Multiple integer parse routine.
 *
 * This function is capable of parsing any number of fields. Only the first
 * two values from the string will be put into @cb however (and as such,
 * @cb->val.uXX_range is just that large) to cater for the few extensions that
 * do not have a range[2] field, but {min, max}, and which cannot use
 * XTOPT_POINTER.
 */
static void xtopt_parse_mint(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	const char *arg = cb->arg;
	size_t esize = xtopt_esize_by_type(entry->type);
	const uintmax_t lmax = xtopt_max_by_type(entry->type);
	void *put = XTOPT_MKPTR(cb);
	unsigned int maxiter;
	uintmax_t value;
	char *end = "";
	char sep = ':';

	maxiter = entry->size / esize;
	if (maxiter == 0)
		maxiter = ARRAY_SIZE(cb->val.u32_range);
	if (entry->size % esize != 0)
		xt_params->exit_err(OTHER_PROBLEM, "%s: memory block does "
			"not have proper size\n", __func__);

	cb->nvals = 0;
	for (arg = cb->arg, end = (char *)arg; ; arg = end + 1) {
		if (cb->nvals == maxiter)
			xt_params->exit_err(PARAMETER_PROBLEM, "%s: Too many "
				"components for option \"--%s\" (max: %u)\n",
				cb->ext_name, entry->name, maxiter);
		if (*arg == '\0' || *arg == sep) {
			/* Default range components when field not spec'd. */
			end = (char *)arg;
			value = (cb->nvals == 1) ? lmax : 0;
		} else {
			if (!xtables_strtoul(arg, &end, &value, 0, lmax))
				xt_params->exit_err(PARAMETER_PROBLEM,
					"%s: bad value for option \"--%s\" near "
					"\"%s\", or out of range (0-%ju).\n",
					cb->ext_name, entry->name, arg, lmax);
			if (*end != '\0' && *end != sep)
				xt_params->exit_err(PARAMETER_PROBLEM,
					"%s: Argument to \"--%s\" has "
					"unexpected characters near \"%s\".\n",
					cb->ext_name, entry->name, end);
		}
		xtopt_mint_value_to_cb(cb, value);
		++cb->nvals;
		xtopt_mint_value_to_ptr(cb, &put, value);
		if (*end == '\0')
			break;
	}
}

static void xtopt_parse_string(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	size_t z = strlen(cb->arg);
	char *p;

	if (entry->min != 0 && z < entry->min)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"Argument must have a minimum length of "
			"%u characters\n", entry->min);
	if (entry->max != 0 && z > entry->max)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"Argument must have a maximum length of "
			"%u characters\n", entry->max);
	if (!(entry->flags & XTOPT_PUT))
		return;
	if (z >= entry->size)
		z = entry->size - 1;
	p = XTOPT_MKPTR(cb);
	strncpy(p, cb->arg, z);
	p[z] = '\0';
}

static const struct tos_symbol_info {
	unsigned char value;
	const char *name;
} tos_symbol_names[] = {
	{IPTOS_LOWDELAY,    "Minimize-Delay"},
	{IPTOS_THROUGHPUT,  "Maximize-Throughput"},
	{IPTOS_RELIABILITY, "Maximize-Reliability"},
	{IPTOS_MINCOST,     "Minimize-Cost"},
	{IPTOS_NORMALSVC,   "Normal-Service"},
	{},
};

/*
 * tos_parse_numeric - parse a string like "15/255"
 *
 * @str:	input string
 * @tvm:	(value/mask) tuple
 * @max:	maximum allowed value (must be pow(2,some_int)-1)
 */
static bool tos_parse_numeric(const char *str, struct xt_option_call *cb,
                              unsigned int max)
{
	unsigned int value;
	char *end;

	xtables_strtoui(str, &end, &value, 0, max);
	cb->val.tos_value = value;
	cb->val.tos_mask  = max;

	if (*end == '/') {
		const char *p = end + 1;

		if (!xtables_strtoui(p, &end, &value, 0, max))
			xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"",
			           str);
		cb->val.tos_mask = value;
	}

	if (*end != '\0')
		xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"", str);
	return true;
}

/**
 * @str:	input string
 * @tvm:	(value/mask) tuple
 * @def_mask:	mask to force when a symbolic name is used
 */
static void xtopt_parse_tosmask(struct xt_option_call *cb)
{
	const struct tos_symbol_info *symbol;
	char *tmp;

	if (xtables_strtoui(cb->arg, &tmp, NULL, 0, UINT8_MAX)) {
		tos_parse_numeric(cb->arg, cb, UINT8_MAX);
		return;
	}
	/*
	 * This is our way we deal with different defaults
	 * for different revisions.
	 */
	cb->val.tos_mask = cb->entry->max;
	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
		if (strcasecmp(cb->arg, symbol->name) == 0) {
			cb->val.tos_value = symbol->value;
			return;
		}

	xtables_error(PARAMETER_PROBLEM, "Symbolic name \"%s\" is unknown",
		      cb->arg);
}

/**
 * Validate the input for being conformant to "mark[/mask]".
 */
static void xtopt_parse_markmask(struct xt_option_call *cb)
{
	unsigned int mark = 0, mask = ~0U;
	char *end;

	if (!xtables_strtoui(cb->arg, &end, &mark, 0, UINT32_MAX))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: bad mark value for option \"--%s\", "
			"or out of range.\n",
			cb->ext_name, cb->entry->name);
	if (*end == '/' &&
	    !xtables_strtoui(end + 1, &end, &mask, 0, UINT32_MAX))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: bad mask value for option \"--%s\", "
			"or out of range.\n",
			cb->ext_name, cb->entry->name);
	if (*end != '\0')
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: trailing garbage after value "
			"for option \"--%s\".\n",
			cb->ext_name, cb->entry->name);
	cb->val.mark = mark;
	cb->val.mask = mask;
}

static int xtopt_sysloglvl_compare(const void *a, const void *b)
{
	const char *name = a;
	const struct syslog_level *entry = b;

	return strcmp(name, entry->name);
}

static void xtopt_parse_sysloglevel(struct xt_option_call *cb)
{
	static const struct syslog_level log_names[] = { /* must be sorted */
		{"alert",   LOG_ALERT},
		{"crit",    LOG_CRIT},
		{"debug",   LOG_DEBUG},
		{"emerg",   LOG_EMERG},
		{"error",   LOG_ERR}, /* deprecated */
		{"info",    LOG_INFO},
		{"notice",  LOG_NOTICE},
		{"panic",   LOG_EMERG}, /* deprecated */
		{"warning", LOG_WARNING},
	};
	const struct syslog_level *e;
	unsigned int num = 0;

	if (!xtables_strtoui(cb->arg, NULL, &num, 0, 7)) {
		e = bsearch(cb->arg, log_names, ARRAY_SIZE(log_names),
			    sizeof(*log_names), xtopt_sysloglvl_compare);
		if (e == NULL)
			xt_params->exit_err(PARAMETER_PROBLEM,
				"log level \"%s\" unknown\n", cb->arg);
		num = e->level;
	}
	cb->val.syslog_level = num;
	if (cb->entry->flags & XTOPT_PUT)
		*(uint8_t *)XTOPT_MKPTR(cb) = num;
}

static void *xtables_sa_host(const void *sa, unsigned int afproto)
{
	if (afproto == AF_INET6)
		return &((struct sockaddr_in6 *)sa)->sin6_addr;
	else if (afproto == AF_INET)
		return &((struct sockaddr_in *)sa)->sin_addr;
	return (void *)sa;
}

static socklen_t xtables_sa_hostlen(unsigned int afproto)
{
	if (afproto == AF_INET6)
		return sizeof(struct in6_addr);
	else if (afproto == AF_INET)
		return sizeof(struct in_addr);
	return 0;
}

/**
 * Accepts: a hostname (DNS), or a single inetaddr - without any mask. The
 * result is stored in @cb->val.haddr. Additionally, @cb->val.hmask and
 * @cb->val.hlen are set for completeness to the appropriate values.
 */
static void xtopt_parse_host(struct xt_option_call *cb)
{
	struct addrinfo hints = {.ai_family = afinfo->family};
	unsigned int adcount = 0;
	struct addrinfo *res, *p;
	int ret;

	ret = getaddrinfo(cb->arg, NULL, &hints, &res);
	if (ret != 0)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"getaddrinfo: %s\n", gai_strerror(ret));

	memset(&cb->val.hmask, 0xFF, sizeof(cb->val.hmask));
	cb->val.hlen = (afinfo->family == NFPROTO_IPV4) ? 32 : 128;

	for (p = res; p != NULL; p = p->ai_next) {
		if (adcount == 0) {
			memset(&cb->val.haddr, 0, sizeof(cb->val.haddr));
			memcpy(&cb->val.haddr,
			       xtables_sa_host(p->ai_addr, p->ai_family),
			       xtables_sa_hostlen(p->ai_family));
			++adcount;
			continue;
		}
		if (memcmp(&cb->val.haddr,
		    xtables_sa_host(p->ai_addr, p->ai_family),
		    xtables_sa_hostlen(p->ai_family)) != 0)
			xt_params->exit_err(PARAMETER_PROBLEM,
				"%s resolves to more than one address\n",
				cb->arg);
	}

	freeaddrinfo(res);
	if (cb->entry->flags & XTOPT_PUT)
		/* Validation in xtables_option_metavalidate */
		memcpy(XTOPT_MKPTR(cb), &cb->val.haddr,
		       sizeof(cb->val.haddr));
}

/**
 * @name:	port name, or number as a string (e.g. "http" or "80")
 *
 * Resolve a port name to a number. Returns the port number in integral
 * form on success, or <0 on error. (errno will not be set.)
 */
static int xtables_getportbyname(const char *name)
{
	struct addrinfo *res = NULL, *p;
	int ret;

	ret = getaddrinfo(NULL, name, NULL, &res);
	if (ret != 0)
		return -1;
	ret = -1;
	for (p = res; p != NULL; p = p->ai_next) {
		if (p->ai_family == AF_INET6) {
			ret = ((struct sockaddr_in6 *)p->ai_addr)->sin6_port;
			break;
		} else if (p->ai_family == AF_INET) {
			ret = ((struct sockaddr_in *)p->ai_addr)->sin_port;
			break;
		}
	}
	freeaddrinfo(res);
	if (ret < 0)
		return ret;
	return ntohs(ret);
}

/**
 * Validate and parse a protocol specification (number or name) by use of
 * /etc/protocols and put the result into @cb->val.protocol.
 */
static void xtopt_parse_protocol(struct xt_option_call *cb)
{
	cb->val.protocol = xtables_parse_protocol(cb->arg);
	if (cb->entry->flags & XTOPT_PUT)
		*(uint8_t *)XTOPT_MKPTR(cb) = cb->val.protocol;
}

/**
 * Validate and parse a port specification and put the result into
 * @cb->val.port.
 */
static void xtopt_parse_port(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	int ret;

	ret = xtables_getportbyname(cb->arg);
	if (ret < 0)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"Port \"%s\" does not resolve to anything.\n",
			cb->arg);
	if (entry->flags & XTOPT_NBO)
		ret = htons(ret);
	cb->val.port = ret;
	if (entry->flags & XTOPT_PUT)
		*(uint16_t *)XTOPT_MKPTR(cb) = cb->val.port;
}

static void xtopt_parse_mport(struct xt_option_call *cb)
{
	static const size_t esize = sizeof(uint16_t);
	const struct xt_option_entry *entry = cb->entry;
	char *lo_arg, *wp_arg, *arg;
	unsigned int maxiter;
	int value;

	wp_arg = lo_arg = strdup(cb->arg);
	if (lo_arg == NULL)
		xt_params->exit_err(RESOURCE_PROBLEM, "strdup");

	maxiter = entry->size / esize;
	if (maxiter == 0)
		maxiter = 2; /* ARRAY_SIZE(cb->val.port_range) */
	if (entry->size % esize != 0)
		xt_params->exit_err(OTHER_PROBLEM, "%s: memory block does "
			"not have proper size\n", __func__);

	cb->val.port_range[0] = 0;
	cb->val.port_range[1] = UINT16_MAX;
	cb->nvals = 0;

	while ((arg = strsep(&wp_arg, ":")) != NULL) {
		if (cb->nvals == maxiter)
			xt_params->exit_err(PARAMETER_PROBLEM, "%s: Too many "
				"components for option \"--%s\" (max: %u)\n",
				cb->ext_name, entry->name, maxiter);
		if (*arg == '\0') {
			++cb->nvals;
			continue;
		}

		value = xtables_getportbyname(arg);
		if (value < 0)
			xt_params->exit_err(PARAMETER_PROBLEM,
				"Port \"%s\" does not resolve to "
				"anything.\n", arg);
		if (entry->flags & XTOPT_NBO)
			value = htons(value);
		if (cb->nvals < ARRAY_SIZE(cb->val.port_range))
			cb->val.port_range[cb->nvals] = value;
		++cb->nvals;
	}

	if (cb->nvals == 1) {
		cb->val.port_range[1] = cb->val.port_range[0];
		++cb->nvals;
	}
	if (entry->flags & XTOPT_PUT)
		memcpy(XTOPT_MKPTR(cb), cb->val.port_range, sizeof(uint16_t) *
		       (cb->nvals <= maxiter ? cb->nvals : maxiter));
	free(lo_arg);
}

static int xtopt_parse_mask(struct xt_option_call *cb)
{
	struct addrinfo hints = {.ai_family = afinfo->family,
				 .ai_flags = AI_NUMERICHOST };
	struct addrinfo *res;
	int ret;

	ret = getaddrinfo(cb->arg, NULL, &hints, &res);
	if (ret != 0)
		return 0;

	memcpy(&cb->val.hmask, xtables_sa_host(res->ai_addr, res->ai_family),
	       xtables_sa_hostlen(res->ai_family));

	switch(afinfo->family) {
	case AF_INET:
		cb->val.hlen = xtables_ipmask_to_cidr(&cb->val.hmask.in);
		break;
	case AF_INET6:
		cb->val.hlen = xtables_ip6mask_to_cidr(&cb->val.hmask.in6);
		break;
	}

	freeaddrinfo(res);
	return 1;
}

/**
 * Parse an integer and ensure it is within the address family's prefix length
 * limits. The result is stored in @cb->val.hlen.
 */
static void xtopt_parse_plen(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	unsigned int prefix_len = 128; /* happiness is a warm gcc */

	cb->val.hlen = (afinfo->family == NFPROTO_IPV4) ? 32 : 128;
	if (!xtables_strtoui(cb->arg, NULL, &prefix_len, 0, cb->val.hlen)) {
		/* Is this mask expressed in full format? e.g. 255.255.255.0 */
		if (xtopt_parse_mask(cb))
			return;

		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: bad value for option \"--%s\", "
			"neither a valid network mask "
			"nor valid CIDR (%u-%u).\n",
			cb->ext_name, entry->name, 0, cb->val.hlen);
	}
	cb->val.hlen = prefix_len;
}

/**
 * Reuse xtopt_parse_plen for testing the integer. Afterwards convert this to
 * a bitmask, and make it available through @cb->val.hmask (hlen remains
 * valid). If %XTOPT_PUT is used, hmask will be copied to the target area.
 */
static void xtopt_parse_plenmask(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	uint32_t *mask = cb->val.hmask.all;

	xtopt_parse_plen(cb);

	memset(mask, 0xFF, sizeof(union nf_inet_addr));
	/* This shifting is AF-independent. */
	if (cb->val.hlen == 0) {
		mask[0] = mask[1] = mask[2] = mask[3] = 0;
	} else if (cb->val.hlen <= 32) {
		mask[0] <<= 32 - cb->val.hlen;
		mask[1] = mask[2] = mask[3] = 0;
	} else if (cb->val.hlen <= 64) {
		mask[1] <<= 32 - (cb->val.hlen - 32);
		mask[2] = mask[3] = 0;
	} else if (cb->val.hlen <= 96) {
		mask[2] <<= 32 - (cb->val.hlen - 64);
		mask[3] = 0;
	} else if (cb->val.hlen <= 128) {
		mask[3] <<= 32 - (cb->val.hlen - 96);
	}
	mask[0] = htonl(mask[0]);
	mask[1] = htonl(mask[1]);
	mask[2] = htonl(mask[2]);
	mask[3] = htonl(mask[3]);
	if (entry->flags & XTOPT_PUT)
		memcpy(XTOPT_MKPTR(cb), mask, sizeof(union nf_inet_addr));
}

static void xtopt_parse_hostmask(struct xt_option_call *cb)
{
	const char *orig_arg = cb->arg;
	char *work, *p;

	if (strchr(cb->arg, '/') == NULL) {
		xtopt_parse_host(cb);
		return;
	}
	work = strdup(orig_arg);
	if (work == NULL)
		xt_params->exit_err(PARAMETER_PROBLEM, "strdup");
	p = strchr(work, '/'); /* by def this can't be NULL now */
	*p++ = '\0';
	/*
	 * Because xtopt_parse_host and xtopt_parse_plenmask would store
	 * different things in the same target area, XTTYPE_HOSTMASK must
	 * disallow XTOPT_PUT, which it does by forcing its absence,
	 * cf. not being listed in xtopt_psize.
	 */
	cb->arg = work;
	xtopt_parse_host(cb);
	cb->arg = p;
	xtopt_parse_plenmask(cb);
	cb->arg = orig_arg;
}

static void xtopt_parse_ethermac(struct xt_option_call *cb)
{
	const char *arg = cb->arg;
	unsigned int i;
	char *end;

	for (i = 0; i < ARRAY_SIZE(cb->val.ethermac) - 1; ++i) {
		cb->val.ethermac[i] = strtoul(arg, &end, 16);
		if (*end != ':' || end - arg > 2)
			goto out;
		arg = end + 1;
	}
	i = ARRAY_SIZE(cb->val.ethermac) - 1;
	cb->val.ethermac[i] = strtoul(arg, &end, 16);
	if (*end != '\0' || end - arg > 2)
		goto out;
	if (cb->entry->flags & XTOPT_PUT)
		memcpy(XTOPT_MKPTR(cb), cb->val.ethermac,
		       sizeof(cb->val.ethermac));
	return;
 out:
	xt_params->exit_err(PARAMETER_PROBLEM, "Invalid MAC address specified.");
}

static void (*const xtopt_subparse[])(struct xt_option_call *) = {
	[XTTYPE_UINT8]       = xtopt_parse_int,
	[XTTYPE_UINT16]      = xtopt_parse_int,
	[XTTYPE_UINT32]      = xtopt_parse_int,
	[XTTYPE_UINT64]      = xtopt_parse_int,
	[XTTYPE_UINT8RC]     = xtopt_parse_mint,
	[XTTYPE_UINT16RC]    = xtopt_parse_mint,
	[XTTYPE_UINT32RC]    = xtopt_parse_mint,
	[XTTYPE_UINT64RC]    = xtopt_parse_mint,
	[XTTYPE_DOUBLE]      = xtopt_parse_float,
	[XTTYPE_STRING]      = xtopt_parse_string,
	[XTTYPE_TOSMASK]     = xtopt_parse_tosmask,
	[XTTYPE_MARKMASK32]  = xtopt_parse_markmask,
	[XTTYPE_SYSLOGLEVEL] = xtopt_parse_sysloglevel,
	[XTTYPE_HOST]        = xtopt_parse_host,
	[XTTYPE_HOSTMASK]    = xtopt_parse_hostmask,
	[XTTYPE_PROTOCOL]    = xtopt_parse_protocol,
	[XTTYPE_PORT]        = xtopt_parse_port,
	[XTTYPE_PORTRC]      = xtopt_parse_mport,
	[XTTYPE_PLEN]        = xtopt_parse_plen,
	[XTTYPE_PLENMASK]    = xtopt_parse_plenmask,
	[XTTYPE_ETHERMAC]    = xtopt_parse_ethermac,
};

/**
 * The master option parsing routine. May be used for the ".x6_parse"
 * function pointer in extensions if fully automatic parsing is desired.
 * It may be also called manually from a custom x6_parse function.
 */
void xtables_option_parse(struct xt_option_call *cb)
{
	const struct xt_option_entry *entry = cb->entry;
	unsigned int eflag = 1 << cb->entry->id;

	/*
	 * With {.id = P_FOO, .excl = P_FOO} we can have simple double-use
	 * prevention. Though it turned out that this is too much typing (most
	 * of the options are one-time use only), so now we also have
	 * %XTOPT_MULTI.
	 */
	if ((!(entry->flags & XTOPT_MULTI) || (entry->excl & eflag)) &&
	    cb->xflags & eflag)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: option \"--%s\" can only be used once.\n",
			cb->ext_name, cb->entry->name);
	if (cb->invert && !(entry->flags & XTOPT_INVERT))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: option \"--%s\" cannot be inverted.\n",
			cb->ext_name, entry->name);
	if (entry->type != XTTYPE_NONE && optarg == NULL)
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: option \"--%s\" requires an argument.\n",
			cb->ext_name, entry->name);
	/*
	 * Fill in fallback value for "nvals", in case an extension (as it
	 * happened with libxt_conntrack.2) tries to read it, despite not using
	 * a *RC option type.
	 */
	cb->nvals = 1;
	if (entry->type <= ARRAY_SIZE(xtopt_subparse) &&
	    xtopt_subparse[entry->type] != NULL)
		xtopt_subparse[entry->type](cb);
	/* Exclusion with other flags tested later in finalize. */
	cb->xflags |= 1 << entry->id;
}

/**
 * Verifies that an extension's option map descriptor is valid, and ought to
 * be called right after the extension has been loaded, and before option
 * merging/xfrm.
 */
void xtables_option_metavalidate(const char *name,
				 const struct xt_option_entry *entry)
{
	for (; entry->name != NULL; ++entry) {
		if (entry->id >= CHAR_BIT * sizeof(unsigned int) ||
		    entry->id >= XT_OPTION_OFFSET_SCALE)
			xt_params->exit_err(OTHER_PROBLEM,
				"Extension %s uses invalid ID %u\n",
				name, entry->id);
		if (!(entry->flags & XTOPT_PUT)) {
			if (entry->ptroff != 0)
				xt_params->exit_err(OTHER_PROBLEM,
					"%s: ptroff for \"--%s\" is non-"
					"zero but no XTOPT_PUT is specified. "
					"Oversight?", name, entry->name);
			continue;
		}
		if (entry->type >= ARRAY_SIZE(xtopt_psize) ||
		    xtopt_psize[entry->type] == 0)
			xt_params->exit_err(OTHER_PROBLEM,
				"%s: entry type of option \"--%s\" cannot be "
				"combined with XTOPT_PUT\n",
				name, entry->name);
		if (xtopt_psize[entry->type] != -1 &&
		    xtopt_psize[entry->type] != entry->size)
			xt_params->exit_err(OTHER_PROBLEM,
				"%s: option \"--%s\" points to a memory block "
				"of wrong size (expected %zu, got %zu)\n",
				name, entry->name,
				xtopt_psize[entry->type], entry->size);
	}
}

/**
 * Find an option entry by its id.
 */
static const struct xt_option_entry *
xtables_option_lookup(const struct xt_option_entry *entry, unsigned int id)
{
	for (; entry->name != NULL; ++entry)
		if (entry->id == id)
			return entry;
	return NULL;
}

/**
 * @c:		getopt id (i.e. with offset)
 * @fw:		struct ipt_entry or ip6t_entry
 *
 * Dispatch arguments to the appropriate parse function, based upon the
 * extension's choice of API.
 */
void xtables_option_tpcall(unsigned int c, char **argv, bool invert,
			   struct xtables_target *t, void *fw)
{
	struct xt_option_call cb;

	if (t->x6_parse == NULL) {
		if (t->parse != NULL)
			t->parse(c - t->option_offset, argv, invert,
				 &t->tflags, fw, &t->t);
		return;
	}

	c -= t->option_offset;
	cb.entry = xtables_option_lookup(t->x6_options, c);
	if (cb.entry == NULL)
		xtables_error(OTHER_PROBLEM,
			"Extension does not know id %u\n", c);
	cb.arg      = optarg;
	cb.invert   = invert;
	cb.ext_name = t->name;
	cb.data     = t->t->data;
	cb.xflags   = t->tflags;
	cb.target   = &t->t;
	cb.xt_entry = fw;
	cb.udata    = t->udata;
	t->x6_parse(&cb);
	t->tflags = cb.xflags;
}

/**
 * @c:		getopt id (i.e. with offset)
 * @fw:		struct ipt_entry or ip6t_entry
 *
 * Dispatch arguments to the appropriate parse function, based upon the
 * extension's choice of API.
 */
void xtables_option_mpcall(unsigned int c, char **argv, bool invert,
			   struct xtables_match *m, void *fw)
{
	struct xt_option_call cb;

	if (m->x6_parse == NULL) {
		if (m->parse != NULL)
			m->parse(c - m->option_offset, argv, invert,
				 &m->mflags, fw, &m->m);
		return;
	}

	c -= m->option_offset;
	cb.entry = xtables_option_lookup(m->x6_options, c);
	if (cb.entry == NULL)
		xtables_error(OTHER_PROBLEM,
			"Extension does not know id %u\n", c);
	cb.arg      = optarg;
	cb.invert   = invert;
	cb.ext_name = m->name;
	cb.data     = m->m->data;
	cb.xflags   = m->mflags;
	cb.match    = &m->m;
	cb.xt_entry = fw;
	cb.udata    = m->udata;
	m->x6_parse(&cb);
	m->mflags = cb.xflags;
}

/**
 * @name:	name of extension
 * @entry:	current option (from all ext's entries) being validated
 * @xflags:	flags the extension has collected
 * @i:		conflicting option (id) to test for
 */
static void
xtables_option_fcheck2(const char *name, const struct xt_option_entry *entry,
		       const struct xt_option_entry *other,
		       unsigned int xflags)
{
	unsigned int ef = 1 << entry->id, of = 1 << other->id;

	if (entry->also & of && !(xflags & of))
		xt_params->exit_err(PARAMETER_PROBLEM,
			"%s: option \"--%s\" also requires \"--%s\".\n",
			name, entry->name, other->name);

	if (!(entry->excl & of))
		/* Use of entry does not collide with other option, good. */
		return;
	if ((xflags & (ef | of)) != (ef | of))
		/* Conflicting options were not used. */
		return;

	xt_params->exit_err(PARAMETER_PROBLEM,
		"%s: option \"--%s\" cannot be used together with \"--%s\".\n",
		name, entry->name, other->name);
}

/**
 * @name:	name of extension
 * @xflags:	accumulated flags
 * @entry:	extension's option table
 *
 * Check that all option constraints have been met. This effectively replaces
 * ->final_check of the older API.
 */
void xtables_options_fcheck(const char *name, unsigned int xflags,
			    const struct xt_option_entry *table)
{
	const struct xt_option_entry *entry, *other;
	unsigned int i;

	for (entry = table; entry->name != NULL; ++entry) {
		if (entry->flags & XTOPT_MAND &&
		    !(xflags & (1 << entry->id)))
			xt_params->exit_err(PARAMETER_PROBLEM,
				"%s: option \"--%s\" must be specified\n",
				name, entry->name);
		if (!(xflags & (1 << entry->id)))
			/* Not required, not specified, thus skip. */
			continue;

		for (i = 0; i < CHAR_BIT * sizeof(entry->id); ++i) {
			if (entry->id == i)
				/*
				 * Avoid conflict with self. Multi-use check
				 * was done earlier in xtables_option_parse.
				 */
				continue;
			other = xtables_option_lookup(table, i);
			if (other == NULL)
				continue;
			xtables_option_fcheck2(name, entry, other, xflags);
		}
	}
}

/**
 * Dispatch arguments to the appropriate final_check function, based upon the
 * extension's choice of API.
 */
void xtables_option_tfcall(struct xtables_target *t)
{
	if (t->x6_fcheck != NULL) {
		struct xt_fcheck_call cb;

		cb.ext_name = t->name;
		cb.data     = t->t->data;
		cb.xflags   = t->tflags;
		cb.udata    = t->udata;
		t->x6_fcheck(&cb);
	} else if (t->final_check != NULL) {
		t->final_check(t->tflags);
	}
	if (t->x6_options != NULL)
		xtables_options_fcheck(t->name, t->tflags, t->x6_options);
}

/**
 * Dispatch arguments to the appropriate final_check function, based upon the
 * extension's choice of API.
 */
void xtables_option_mfcall(struct xtables_match *m)
{
	if (m->x6_fcheck != NULL) {
		struct xt_fcheck_call cb;

		cb.ext_name = m->name;
		cb.data     = m->m->data;
		cb.xflags   = m->mflags;
		cb.udata    = m->udata;
		m->x6_fcheck(&cb);
	} else if (m->final_check != NULL) {
		m->final_check(m->mflags);
	}
	if (m->x6_options != NULL)
		xtables_options_fcheck(m->name, m->mflags, m->x6_options);
}

struct xtables_lmap *xtables_lmap_init(const char *file)
{
	struct xtables_lmap *lmap_head = NULL, *lmap_prev = NULL, *lmap_this;
	char buf[512];
	FILE *fp;
	char *cur, *nxt;
	int id;

	fp = fopen(file, "re");
	if (fp == NULL)
		return NULL;

	while (fgets(buf, sizeof(buf), fp) != NULL) {
		cur = buf;
		while (isspace(*cur))
			++cur;
		if (*cur == '#' || *cur == '\n' || *cur == '\0')
			continue;

		/* iproute2 allows hex and dec format */
		errno = 0;
		id = strtoul(cur, &nxt, strncmp(cur, "0x", 2) == 0 ? 16 : 10);
		if (nxt == cur || errno != 0)
			continue;

		/* same boundaries as in iproute2 */
		if (id < 0 || id > 255)
			continue;
		cur = nxt;

		if (!isspace(*cur))
			continue;
		while (isspace(*cur))
			++cur;
		if (*cur == '#' || *cur == '\n' || *cur == '\0')
			continue;
		nxt = cur;
		while (*nxt != '\0' && !isspace(*nxt))
			++nxt;
		if (nxt == cur)
			continue;
		*nxt = '\0';

		/* found valid data */
		lmap_this = malloc(sizeof(*lmap_this));
		if (lmap_this == NULL) {
			perror("malloc");
			goto out;
		}
		lmap_this->id   = id;
		lmap_this->name = strdup(cur);
		if (lmap_this->name == NULL) {
			free(lmap_this);
			goto out;
		}
		lmap_this->next = NULL;

		if (lmap_prev != NULL)
			lmap_prev->next = lmap_this;
		else
			lmap_head = lmap_this;
		lmap_prev = lmap_this;
	}

	fclose(fp);
	return lmap_head;
 out:
	fclose(fp);
	xtables_lmap_free(lmap_head);
	return NULL;
}

void xtables_lmap_free(struct xtables_lmap *head)
{
	struct xtables_lmap *next;

	for (; head != NULL; head = next) {
		next = head->next;
		free(head->name);
		free(head);
	}
}

int xtables_lmap_name2id(const struct xtables_lmap *head, const char *name)
{
	for (; head != NULL; head = head->next)
		if (strcmp(head->name, name) == 0)
			return head->id;
	return -1;
}

const char *xtables_lmap_id2name(const struct xtables_lmap *head, int id)
{
	for (; head != NULL; head = head->next)
		if (head->id == id)
			return head->name;
	return NULL;
}