Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
/*	$NetBSD: getaddrinfo.c,v 1.1.1.1 2009/04/12 15:33:44 christos Exp $	*/

/*	$KAME: getaddrinfo.c,v 1.14 2001/01/06 09:41:15 jinmei Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*! \file
 * Issues to be discussed:
 *\li  Thread safe-ness must be checked.
 *\li  Return values.  There are nonstandard return values defined and used
 *   in the source code.  This is because RFC2553 is silent about which error
 *   code must be returned for which situation.
 *\li  IPv4 classful (shortened) form.  RFC2553 is silent about it.  XNET 5.2
 *   says to use inet_aton() to convert IPv4 numeric to binary (allows
 *   classful form as a result).
 *   current code - disallow classful form for IPv4 (due to use of inet_pton).
 *\li  freeaddrinfo(NULL).  RFC2553 is silent about it.  XNET 5.2 says it is
 *   invalid.
 *   current code - SEGV on freeaddrinfo(NULL)
 * Note:
 *\li  We use getipnodebyname() just for thread-safeness.  There's no intent
 *   to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
 *   getipnodebyname().
 *\li  The code filters out AFs that are not supported by the kernel,
 *   when globbing NULL hostname (to loopback, or wildcard).  Is it the right
 *   thing to do?  What is the relationship with post-RFC2553 AI_ADDRCONFIG
 *   in ai_flags?
 *\li  (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
 *   (1) what should we do against numeric hostname (2) what should we do
 *   against NULL hostname (3) what is AI_ADDRCONFIG itself.  AF not ready?
 *   non-loopback address configured?  global address configured?
 * \par Additional Issue:
 *  To avoid search order issue, we have a big amount of code duplicate
 *   from gethnamaddr.c and some other places.  The issues that there's no
 *   lower layer function to lookup "IPv4 or IPv6" record.  Calling
 *   gethostbyname2 from getaddrinfo will end up in wrong search order, as
 *   follows:
 *	\li The code makes use of following calls when asked to resolver with
 *	  ai_family  = PF_UNSPEC:
 *\code		getipnodebyname(host, AF_INET6);
 *		getipnodebyname(host, AF_INET);
 *\endcode
 *	\li  This will result in the following queries if the node is configure to
 *	  prefer /etc/hosts than DNS:
 *\code
 *		lookup /etc/hosts for IPv6 address
 *		lookup DNS for IPv6 address
 *		lookup /etc/hosts for IPv4 address
 *		lookup DNS for IPv4 address
 *\endcode
 *	  which may not meet people's requirement.
 *	 \li The right thing to happen is to have underlying layer which does
 *	  PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
 *	  This would result in a bit of code duplicate with _dns_ghbyname() and
 *	  friends.
 */

#include "port_before.h"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>

#include <net/if.h>
#include <netinet/in.h>

#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>

#include <stdarg.h>

#include <irs.h>
#include <isc/assertions.h>

#include "port_after.h"

#include "irs_data.h"

#define SUCCESS 0
#define ANY 0
#define YES 1
#define NO  0

static const char in_addrany[] = { 0, 0, 0, 0 };
static const char in6_addrany[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const char in_loopback[] = { 127, 0, 0, 1 };
static const char in6_loopback[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
};

static const struct afd {
	int a_af;
	int a_addrlen;
	int a_socklen;
	int a_off;
	const char *a_addrany;
	const char *a_loopback;
	int a_scoped;
} afdl [] = {
	{PF_INET6, sizeof(struct in6_addr),
	 sizeof(struct sockaddr_in6),
	 offsetof(struct sockaddr_in6, sin6_addr),
	 in6_addrany, in6_loopback, 1},
	{PF_INET, sizeof(struct in_addr),
	 sizeof(struct sockaddr_in),
	 offsetof(struct sockaddr_in, sin_addr),
	 in_addrany, in_loopback, 0},
	{0, 0, 0, 0, NULL, NULL, 0},
};

struct explore {
	int e_af;
	int e_socktype;
	int e_protocol;
	const char *e_protostr;
	int e_wild;
#define WILD_AF(ex)		((ex)->e_wild & 0x01)
#define WILD_SOCKTYPE(ex)	((ex)->e_wild & 0x02)
#define WILD_PROTOCOL(ex)	((ex)->e_wild & 0x04)
};

static const struct explore explore[] = {
#if 0
	{ PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
#endif
	{ PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
	{ PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
	{ PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
	{ PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
	{ PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
	{ PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
	{ -1, 0, 0, NULL, 0 },
};

#define PTON_MAX	16

static int str_isnumber __P((const char *));
static int explore_fqdn __P((const struct addrinfo *, const char *,
	const char *, struct addrinfo **));
static int explore_copy __P((const struct addrinfo *, const struct addrinfo *,
	struct addrinfo **));
static int explore_null __P((const struct addrinfo *,
	const char *, struct addrinfo **));
static int explore_numeric __P((const struct addrinfo *, const char *,
	const char *, struct addrinfo **));
static int explore_numeric_scope __P((const struct addrinfo *, const char *,
	const char *, struct addrinfo **));
static int get_canonname __P((const struct addrinfo *,
	struct addrinfo *, const char *));
static struct addrinfo *get_ai __P((const struct addrinfo *,
	const struct afd *, const char *));
static struct addrinfo *copy_ai __P((const struct addrinfo *));
static int get_portmatch __P((const struct addrinfo *, const char *));
static int get_port __P((const struct addrinfo *, const char *, int));
static const struct afd *find_afd __P((int));
static int addrconfig __P((int));
static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *,
				u_int32_t *scopeidp));
static struct net_data *init __P((void));

struct addrinfo *hostent2addrinfo __P((struct hostent *,
				       const struct addrinfo *));
struct addrinfo *addr2addrinfo __P((const struct addrinfo *,
				    const char *));

#if 0
static const char *ai_errlist[] = {
	"Success",
	"Address family for hostname not supported",	/*%< EAI_ADDRFAMILY */
	"Temporary failure in name resolution",		/*%< EAI_AGAIN */
	"Invalid value for ai_flags",		       	/*%< EAI_BADFLAGS */
	"Non-recoverable failure in name resolution", 	/*%< EAI_FAIL */
	"ai_family not supported",			/*%< EAI_FAMILY */
	"Memory allocation failure", 			/*%< EAI_MEMORY */
	"No address associated with hostname", 		/*%< EAI_NODATA */
	"hostname nor servname provided, or not known",	/*%< EAI_NONAME */
	"servname not supported for ai_socktype",	/*%< EAI_SERVICE */
	"ai_socktype not supported", 			/*%< EAI_SOCKTYPE */
	"System error returned in errno", 		/*%< EAI_SYSTEM */
	"Invalid value for hints",			/*%< EAI_BADHINTS */
	"Resolved protocol is unknown",			/*%< EAI_PROTOCOL */
	"Unknown error", 				/*%< EAI_MAX */
};
#endif

/* XXX macros that make external reference is BAD. */

#define GET_AI(ai, afd, addr) \
do { \
	/* external reference: pai, error, and label free */ \
	(ai) = get_ai(pai, (afd), (addr)); \
	if ((ai) == NULL) { \
		error = EAI_MEMORY; \
		goto free; \
	} \
} while (/*CONSTCOND*/0)

#define GET_PORT(ai, serv) \
do { \
	/* external reference: error and label free */ \
	error = get_port((ai), (serv), 0); \
	if (error != 0) \
		goto free; \
} while (/*CONSTCOND*/0)

#define GET_CANONNAME(ai, str) \
do { \
	/* external reference: pai, error and label free */ \
	error = get_canonname(pai, (ai), (str)); \
	if (error != 0) \
		goto free; \
} while (/*CONSTCOND*/0)

#ifndef SOLARIS2
#define SETERROR(err) \
do { \
	/* external reference: error, and label bad */ \
	error = (err); \
	goto bad; \
	/*NOTREACHED*/ \
} while (/*CONSTCOND*/0)
#else
#define SETERROR(err) \
do { \
	/* external reference: error, and label bad */ \
	error = (err); \
	if (error == error) \
		goto bad; \
} while (/*CONSTCOND*/0)
#endif


#define MATCH_FAMILY(x, y, w) \
	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
#define MATCH(x, y, w) \
	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))

#if 0				/*%< bind8 has its own version */
char *
gai_strerror(ecode)
	int ecode;
{
	if (ecode < 0 || ecode > EAI_MAX)
		ecode = EAI_MAX;
	return ai_errlist[ecode];
}
#endif

void
freeaddrinfo(ai)
	struct addrinfo *ai;
{
	struct addrinfo *next;

	do {
		next = ai->ai_next;
		if (ai->ai_canonname)
			free(ai->ai_canonname);
		/* no need to free(ai->ai_addr) */
		free(ai);
		ai = next;
	} while (ai);
}

static int
str_isnumber(p)
	const char *p;
{
	char *ep;

	if (*p == '\0')
		return NO;
	ep = NULL;
	errno = 0;
	(void)strtoul(p, &ep, 10);
	if (errno == 0 && ep && *ep == '\0')
		return YES;
	else
		return NO;
}

int
getaddrinfo(hostname, servname, hints, res)
	const char *hostname, *servname;
	const struct addrinfo *hints;
	struct addrinfo **res;
{
	struct addrinfo sentinel;
	struct addrinfo *cur;
	int error = 0;
	struct addrinfo ai, ai0, *afai = NULL;
	struct addrinfo *pai;
	const struct explore *ex;

	memset(&sentinel, 0, sizeof(sentinel));
	cur = &sentinel;
	pai = &ai;
	pai->ai_flags = 0;
	pai->ai_family = PF_UNSPEC;
	pai->ai_socktype = ANY;
	pai->ai_protocol = ANY;
#if defined(sun) && defined(_SOCKLEN_T) && defined(__sparcv9)
	/*
	 * clear _ai_pad to preserve binary
	 * compatibility with previously compiled 64-bit
	 * applications in a pre-SUSv3 environment by
	 * guaranteeing the upper 32-bits are empty.
	 */
	pai->_ai_pad = 0;
#endif
	pai->ai_addrlen = 0;
	pai->ai_canonname = NULL;
	pai->ai_addr = NULL;
	pai->ai_next = NULL;

	if (hostname == NULL && servname == NULL)
		return EAI_NONAME;
	if (hints) {
		/* error check for hints */
		if (hints->ai_addrlen || hints->ai_canonname ||
		    hints->ai_addr || hints->ai_next)
			SETERROR(EAI_BADHINTS); /*%< xxx */
		if (hints->ai_flags & ~AI_MASK)
			SETERROR(EAI_BADFLAGS);
		switch (hints->ai_family) {
		case PF_UNSPEC:
		case PF_INET:
		case PF_INET6:
			break;
		default:
			SETERROR(EAI_FAMILY);
		}
		memcpy(pai, hints, sizeof(*pai));

#if defined(sun) && defined(_SOCKLEN_T) && defined(__sparcv9)
		/*
		 * We need to clear _ai_pad to preserve binary
		 * compatibility.  See prior comment.
		 */
		pai->_ai_pad = 0;
#endif
		/*
		 * if both socktype/protocol are specified, check if they
		 * are meaningful combination.
		 */
		if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
			for (ex = explore; ex->e_af >= 0; ex++) {
				if (pai->ai_family != ex->e_af)
					continue;
				if (ex->e_socktype == ANY)
					continue;
				if (ex->e_protocol == ANY)
					continue;
				if (pai->ai_socktype == ex->e_socktype &&
				    pai->ai_protocol != ex->e_protocol) {
					SETERROR(EAI_BADHINTS);
				}
			}
		}
	}

	/*
	 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
	 * AF_INET6 query.  They needs to be ignored if specified in other
	 * occassions.
	 */
	switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
	case AI_V4MAPPED:
	case AI_ALL | AI_V4MAPPED:
		if (pai->ai_family != AF_INET6)
			pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
		break;
	case AI_ALL:
#if 1
		/* illegal */
		SETERROR(EAI_BADFLAGS);
#else
		pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
		break;
#endif
	}

	/*
	 * check for special cases.  (1) numeric servname is disallowed if
	 * socktype/protocol are left unspecified. (2) servname is disallowed
	 * for raw and other inet{,6} sockets.
	 */
	if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
#ifdef PF_INET6
	 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
#endif
	    ) {
		ai0 = *pai;	/* backup *pai */

		if (pai->ai_family == PF_UNSPEC) {
#ifdef PF_INET6
			pai->ai_family = PF_INET6;
#else
			pai->ai_family = PF_INET;
#endif
		}
		error = get_portmatch(pai, servname);
		if (error)
			SETERROR(error);

		*pai = ai0;
	}

	ai0 = *pai;

	/* NULL hostname, or numeric hostname */
	for (ex = explore; ex->e_af >= 0; ex++) {
		*pai = ai0;

		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
			continue;
		if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
			continue;
		if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
			continue;

		if (pai->ai_family == PF_UNSPEC)
			pai->ai_family = ex->e_af;
		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
			pai->ai_socktype = ex->e_socktype;
		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
			pai->ai_protocol = ex->e_protocol;

		/*
		 * if the servname does not match socktype/protocol, ignore it.
		 */
		if (get_portmatch(pai, servname) != 0)
			continue;

		if (hostname == NULL) {
			/*
			 * filter out AFs that are not supported by the kernel
			 * XXX errno?
			 */
			if (!addrconfig(pai->ai_family))
				continue;
			error = explore_null(pai, servname, &cur->ai_next);
		} else
			error = explore_numeric_scope(pai, hostname, servname,
			    &cur->ai_next);

		if (error)
			goto free;

		while (cur && cur->ai_next)
			cur = cur->ai_next;
	}

	/*
	 * XXX
	 * If numreic representation of AF1 can be interpreted as FQDN
	 * representation of AF2, we need to think again about the code below.
	 */
	if (sentinel.ai_next)
		goto good;

	if (pai->ai_flags & AI_NUMERICHOST)
		SETERROR(EAI_NONAME);
	if (hostname == NULL)
		SETERROR(EAI_NONAME);

	/*
	 * hostname as alphabetical name.
	 * We'll make sure that
	 * - if returning addrinfo list is empty, return non-zero error
	 *   value (already known one or EAI_NONAME).
	 * - otherwise, 
	 *   + if we haven't had any errors, return 0 (i.e. success).
	 *   + if we've had an error, free the list and return the error.
	 * without any assumption on the behavior of explore_fqdn().
	 */

	/* first, try to query DNS for all possible address families. */
	*pai = ai0;
	error = explore_fqdn(pai, hostname, servname, &afai);
	if (error) {
		if (afai != NULL)
			freeaddrinfo(afai);
		goto free;
	}
	if (afai == NULL) {
		error = EAI_NONAME; /*%< we've had no errors. */
		goto free;
	}

	/*
	 * we would like to prefer AF_INET6 than AF_INET, so we'll make an
	 * outer loop by AFs.
	 */
	for (ex = explore; ex->e_af >= 0; ex++) {
		*pai = ai0;

		if (pai->ai_family == PF_UNSPEC)
			pai->ai_family = ex->e_af;

		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
			continue;
		if (!MATCH(pai->ai_socktype, ex->e_socktype,
			   WILD_SOCKTYPE(ex))) {
			continue;
		}
		if (!MATCH(pai->ai_protocol, ex->e_protocol,
			   WILD_PROTOCOL(ex))) {
			continue;
		}

#ifdef AI_ADDRCONFIG
		/*
		 * If AI_ADDRCONFIG is specified, check if we are
		 * expected to return the address family or not.
		 */
		if ((pai->ai_flags & AI_ADDRCONFIG) != 0 &&
		    !addrconfig(pai->ai_family))
			continue;
#endif

		if (pai->ai_family == PF_UNSPEC)
			pai->ai_family = ex->e_af;
		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
			pai->ai_socktype = ex->e_socktype;
		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
			pai->ai_protocol = ex->e_protocol;

		/*
		 * if the servname does not match socktype/protocol, ignore it.
		 */
		if (get_portmatch(pai, servname) != 0)
			continue;

		if ((error = explore_copy(pai, afai, &cur->ai_next)) != 0) {
			freeaddrinfo(afai);
			goto free;
		}

		while (cur && cur->ai_next)
			cur = cur->ai_next;
	}

	freeaddrinfo(afai);	/*%< afai must not be NULL at this point. */

	if (sentinel.ai_next) {
good:
		*res = sentinel.ai_next;
		return(SUCCESS);
	} else {
		/*
		 * All the process succeeded, but we've had an empty list. 
		 * This can happen if the given hints do not match our
		 * candidates.
		 */
		error = EAI_NONAME;
	}

free:
bad:
	if (sentinel.ai_next)
		freeaddrinfo(sentinel.ai_next);
	*res = NULL;
	return(error);
}

/*%
 * FQDN hostname, DNS lookup
 */
static int
explore_fqdn(pai, hostname, servname, res)
	const struct addrinfo *pai;
	const char *hostname;
	const char *servname;
	struct addrinfo **res;
{
	struct addrinfo *result;
	struct addrinfo *cur;
	struct net_data *net_data = init();
	struct irs_ho *ho;
	int error = 0;
	char tmp[NS_MAXDNAME];
	const char *cp;

	INSIST(res != NULL && *res == NULL);

	/*
	 * if the servname does not match socktype/protocol, ignore it.
	 */
	if (get_portmatch(pai, servname) != 0)
		return(0);

	if (!net_data || !(ho = net_data->ho))
		return(0);
#if 0				/*%< XXX (notyet) */
	if (net_data->ho_stayopen && net_data->ho_last &&
	    net_data->ho_last->h_addrtype == af) {
		if (ns_samename(name, net_data->ho_last->h_name) == 1)
			return (net_data->ho_last);
		for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
			if (ns_samename(name, *hap) == 1)
				return (net_data->ho_last);
	}
#endif
	if (!strchr(hostname, '.') &&
	    (cp = res_hostalias(net_data->res, hostname,
				tmp, sizeof(tmp))))
		hostname = cp;
	result = (*ho->addrinfo)(ho, hostname, pai);
	if (!net_data->ho_stayopen) {
		(*ho->minimize)(ho);
	}
	if (result == NULL) {
		int e = h_errno;

		switch(e) {
		case NETDB_INTERNAL:
			error = EAI_SYSTEM;
			break;
		case TRY_AGAIN:
			error = EAI_AGAIN;
			break;
		case NO_RECOVERY:
			error = EAI_FAIL;
			break;
		case HOST_NOT_FOUND:
		case NO_DATA:
			error = EAI_NONAME;
			break;
		default:
		case NETDB_SUCCESS: /*%< should be impossible... */
			error = EAI_NONAME;
			break;
		}
		goto free;
	}

	for (cur = result; cur; cur = cur->ai_next) {
		GET_PORT(cur, servname); /*%< XXX: redundant lookups... */
		/* canonname should already be filled. */
	}

	*res = result;

	return(0);

free:
	if (result)
		freeaddrinfo(result);
	return error;
}

static int
explore_copy(pai, src0, res)
	const struct addrinfo *pai;	/*%< seed */
	const struct addrinfo *src0;	/*%< source */
	struct addrinfo **res;
{
	int error;
	struct addrinfo sentinel, *cur;
	const struct addrinfo *src;

	error = 0;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	for (src = src0; src != NULL; src = src->ai_next) {
		if (src->ai_family != pai->ai_family)
			continue;

		cur->ai_next = copy_ai(src);
		if (!cur->ai_next) {
			error = EAI_MEMORY;
			goto fail;
		}

		cur->ai_next->ai_socktype = pai->ai_socktype;
		cur->ai_next->ai_protocol = pai->ai_protocol;
		cur = cur->ai_next;
	}

	*res = sentinel.ai_next;
	return 0;

fail:
	freeaddrinfo(sentinel.ai_next);
	return error;
}

/*%
 * hostname == NULL.
 * passive socket -> anyaddr (0.0.0.0 or ::)
 * non-passive socket -> localhost (127.0.0.1 or ::1)
 */
static int
explore_null(pai, servname, res)
	const struct addrinfo *pai;
	const char *servname;
	struct addrinfo **res;
{
	const struct afd *afd;
	struct addrinfo *cur;
	struct addrinfo sentinel;
	int error;

	*res = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	if (pai->ai_flags & AI_PASSIVE) {
		GET_AI(cur->ai_next, afd, afd->a_addrany);
		/* xxx meaningless?
		 * GET_CANONNAME(cur->ai_next, "anyaddr");
		 */
		GET_PORT(cur->ai_next, servname);
	} else {
		GET_AI(cur->ai_next, afd, afd->a_loopback);
		/* xxx meaningless?
		 * GET_CANONNAME(cur->ai_next, "localhost");
		 */
		GET_PORT(cur->ai_next, servname);
	}
	cur = cur->ai_next;

	*res = sentinel.ai_next;
	return 0;

free:
	if (sentinel.ai_next)
		freeaddrinfo(sentinel.ai_next);
	return error;
}

/*%
 * numeric hostname
 */
static int
explore_numeric(pai, hostname, servname, res)
	const struct addrinfo *pai;
	const char *hostname;
	const char *servname;
	struct addrinfo **res;
{
	const struct afd *afd;
	struct addrinfo *cur;
	struct addrinfo sentinel;
	int error;
	char pton[PTON_MAX];

	*res = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	switch (afd->a_af) {
#if 0 /*X/Open spec*/
	case AF_INET:
		if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
			if (pai->ai_family == afd->a_af ||
			    pai->ai_family == PF_UNSPEC /*?*/) {
				GET_AI(cur->ai_next, afd, pton);
				GET_PORT(cur->ai_next, servname);
				while (cur->ai_next)
					cur = cur->ai_next;
			} else
				SETERROR(EAI_FAMILY);	/*xxx*/
		}
		break;
#endif
	default:
		if (inet_pton(afd->a_af, hostname, pton) == 1) {
			if (pai->ai_family == afd->a_af ||
			    pai->ai_family == PF_UNSPEC /*?*/) {
				GET_AI(cur->ai_next, afd, pton);
				GET_PORT(cur->ai_next, servname);
				while (cur->ai_next)
					cur = cur->ai_next;
			} else
				SETERROR(EAI_FAMILY);	/*xxx*/
		}
		break;
	}

	*res = sentinel.ai_next;
	return 0;

free:
bad:
	if (sentinel.ai_next)
		freeaddrinfo(sentinel.ai_next);
	return error;
}

/*%
 * numeric hostname with scope
 */
static int
explore_numeric_scope(pai, hostname, servname, res)
	const struct addrinfo *pai;
	const char *hostname;
	const char *servname;
	struct addrinfo **res;
{
#ifndef SCOPE_DELIMITER
	return explore_numeric(pai, hostname, servname, res);
#else
	const struct afd *afd;
	struct addrinfo *cur;
	int error;
	char *cp, *hostname2 = NULL, *scope, *addr;
	struct sockaddr_in6 *sin6;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	if (!afd->a_scoped)
		return explore_numeric(pai, hostname, servname, res);

	cp = strchr(hostname, SCOPE_DELIMITER);
	if (cp == NULL)
		return explore_numeric(pai, hostname, servname, res);

	/*
	 * Handle special case of <scoped_address><delimiter><scope id>
	 */
	hostname2 = strdup(hostname);
	if (hostname2 == NULL)
		return EAI_MEMORY;
	/* terminate at the delimiter */
	hostname2[cp - hostname] = '\0';
	addr = hostname2;
	scope = cp + 1;

	error = explore_numeric(pai, addr, servname, res);
	if (error == 0) {
		u_int32_t scopeid = 0;

		for (cur = *res; cur; cur = cur->ai_next) {
			if (cur->ai_family != AF_INET6)
				continue;
			sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
			if (!ip6_str2scopeid(scope, sin6, &scopeid)) {
				free(hostname2);
				return(EAI_NONAME); /*%< XXX: is return OK? */
			}
#ifdef HAVE_SIN6_SCOPE_ID
			sin6->sin6_scope_id = scopeid;
#endif
		}
	}

	free(hostname2);

	return error;
#endif
}

static int
get_canonname(pai, ai, str)
	const struct addrinfo *pai;
	struct addrinfo *ai;
	const char *str;
{
	if ((pai->ai_flags & AI_CANONNAME) != 0) {
		ai->ai_canonname = (char *)malloc(strlen(str) + 1);
		if (ai->ai_canonname == NULL)
			return EAI_MEMORY;
		strcpy(ai->ai_canonname, str);
	}
	return 0;
}

static struct addrinfo *
get_ai(pai, afd, addr)
	const struct addrinfo *pai;
	const struct afd *afd;
	const char *addr;
{
	char *p;
	struct addrinfo *ai;

	ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
		+ (afd->a_socklen));
	if (ai == NULL)
		return NULL;

	memcpy(ai, pai, sizeof(struct addrinfo));
	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
	memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
#ifdef HAVE_SA_LEN
	ai->ai_addr->sa_len = afd->a_socklen;
#endif
	ai->ai_addrlen = afd->a_socklen;
	ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
	p = (char *)(void *)(ai->ai_addr);
	memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
	return ai;
}

/* XXX need to malloc() the same way we do from other functions! */
static struct addrinfo *
copy_ai(pai)
	const struct addrinfo *pai;
{
	struct addrinfo *ai;
	size_t l;

	l = sizeof(*ai) + pai->ai_addrlen;
	if ((ai = (struct addrinfo *)malloc(l)) == NULL)
		return NULL;
	memset(ai, 0, l);
	memcpy(ai, pai, sizeof(*ai));
	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
	memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen);

	if (pai->ai_canonname) {
		l = strlen(pai->ai_canonname) + 1;
		if ((ai->ai_canonname = malloc(l)) == NULL) {
			free(ai);
			return NULL;
		}
		strcpy(ai->ai_canonname, pai->ai_canonname);	/* (checked) */
	} else {
		/* just to make sure */
		ai->ai_canonname = NULL;
	}

	ai->ai_next = NULL;

	return ai;
}

static int
get_portmatch(const struct addrinfo *ai, const char *servname) {

	/* get_port does not touch first argument. when matchonly == 1. */
	/* LINTED const cast */
	return get_port((const struct addrinfo *)ai, servname, 1);
}

static int
get_port(const struct addrinfo *ai, const char *servname, int matchonly) {
	const char *proto;
	struct servent *sp;
	int port;
	int allownumeric;

	if (servname == NULL)
		return 0;
	switch (ai->ai_family) {
	case AF_INET:
#ifdef AF_INET6
	case AF_INET6:
#endif
		break;
	default:
		return 0;
	}

	switch (ai->ai_socktype) {
	case SOCK_RAW:
		return EAI_SERVICE;
	case SOCK_DGRAM:
	case SOCK_STREAM:
		allownumeric = 1;
		break;
	case ANY:
		switch (ai->ai_family) {
		case AF_INET:
#ifdef AF_INET6
		case AF_INET6:
#endif
			allownumeric = 1;
			break;
		default:
			allownumeric = 0;
			break;
		}
		break;
	default:
		return EAI_SOCKTYPE;
	}

	if (str_isnumber(servname)) {
		if (!allownumeric)
			return EAI_SERVICE;
		port = atoi(servname);
		if (port < 0 || port > 65535)
			return EAI_SERVICE;
		port = htons(port);
	} else {
		switch (ai->ai_socktype) {
		case SOCK_DGRAM:
			proto = "udp";
			break;
		case SOCK_STREAM:
			proto = "tcp";
			break;
		default:
			proto = NULL;
			break;
		}

		if ((sp = getservbyname(servname, proto)) == NULL)
			return EAI_SERVICE;
		port = sp->s_port;
	}

	if (!matchonly) {
		switch (ai->ai_family) {
		case AF_INET:
			((struct sockaddr_in *)(void *)
			    ai->ai_addr)->sin_port = port;
			break;
		case AF_INET6:
			((struct sockaddr_in6 *)(void *)
			    ai->ai_addr)->sin6_port = port;
			break;
		}
	}

	return 0;
}

static const struct afd *
find_afd(af)
	int af;
{
	const struct afd *afd;

	if (af == PF_UNSPEC)
		return NULL;
	for (afd = afdl; afd->a_af; afd++) {
		if (afd->a_af == af)
			return afd;
	}
	return NULL;
}

/*%
 * post-2553: AI_ADDRCONFIG check.  if we use getipnodeby* as backend, backend
 * will take care of it.
 * the semantics of AI_ADDRCONFIG is not defined well.  we are not sure
 * if the code is right or not.
 */
static int
addrconfig(af)
	int af;
{
	int s;

	/* XXX errno */
	s = socket(af, SOCK_DGRAM, 0);
	if (s < 0) {
		if (errno != EMFILE)
			return 0;
	} else
		close(s);
	return 1;
}

/* convert a string to a scope identifier. XXX: IPv6 specific */
static int
ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6,
		u_int32_t *scopeidp)
{
	u_int32_t scopeid;
	u_long lscopeid;
	struct in6_addr *a6 = &sin6->sin6_addr;
	char *ep;
	
	/* empty scopeid portion is invalid */
	if (*scope == '\0')
		return (0);

#ifdef USE_IFNAMELINKID
	if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
	    IN6_IS_ADDR_MC_NODELOCAL(a6)) {
		/*
		 * Using interface names as link indices can be allowed
		 * only when we can assume a one-to-one mappings between
		 * links and interfaces.  See comments in getnameinfo.c.
		 */
		scopeid = if_nametoindex(scope);
		if (scopeid == 0)
			goto trynumeric;
		*scopeidp = scopeid;
		return (1);
	}
#endif

	/* still unclear about literal, allow numeric only - placeholder */
	if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
		goto trynumeric;
	if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
		goto trynumeric;
	else
		goto trynumeric;	/*%< global */
	/* try to convert to a numeric id as a last resort */
trynumeric:
	errno = 0;
	lscopeid = strtoul(scope, &ep, 10);
	scopeid = lscopeid & 0xffffffff;
	if (errno == 0 && ep && *ep == '\0' && scopeid == lscopeid) {
		*scopeidp = scopeid;
		return (1);
	} else
		return (0);
}

struct addrinfo *
hostent2addrinfo(hp, pai)
	struct hostent *hp;
	const struct addrinfo *pai;
{
	int i, af, error = 0;
	char **aplist = NULL, *ap;
	struct addrinfo sentinel, *cur;
	const struct afd *afd;

	af = hp->h_addrtype;
	if (pai->ai_family != AF_UNSPEC && af != pai->ai_family)
		return(NULL);

	afd = find_afd(af);
	if (afd == NULL)
		return(NULL);

	aplist = hp->h_addr_list;

	memset(&sentinel, 0, sizeof(sentinel));
	cur = &sentinel;

	for (i = 0; (ap = aplist[i]) != NULL; i++) {
#if 0				/*%< the trick seems too much */
		af = hp->h_addr_list;
		if (af == AF_INET6 &&
		    IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
			af = AF_INET;
			ap = ap + sizeof(struct in6_addr)
				- sizeof(struct in_addr);
		}
		afd = find_afd(af);
		if (afd == NULL)
			continue;
#endif /* 0 */

		GET_AI(cur->ai_next, afd, ap);

		/* GET_PORT(cur->ai_next, servname); */
		if ((pai->ai_flags & AI_CANONNAME) != 0) {
			/*
			 * RFC2553 says that ai_canonname will be set only for
			 * the first element.  we do it for all the elements,
			 * just for convenience.
			 */
			GET_CANONNAME(cur->ai_next, hp->h_name);
		}
		while (cur->ai_next) /*%< no need to loop, actually. */
			cur = cur->ai_next;
		continue;

	free:
		if (cur->ai_next)
			freeaddrinfo(cur->ai_next);
		cur->ai_next = NULL;
		/* continue, without tht pointer CUR advanced. */
	}

	return(sentinel.ai_next);
}

struct addrinfo *
addr2addrinfo(pai, cp)
	const struct addrinfo *pai;
	const char *cp;
{
	const struct afd *afd;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return(NULL);

	return(get_ai(pai, afd, cp));
}

static struct net_data *
init()
{
	struct net_data *net_data;

	if (!(net_data = net_data_init(NULL)))
		goto error;
	if (!net_data->ho) {
		net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
		if (!net_data->ho || !net_data->res) {
error:
			errno = EIO;
			if (net_data && net_data->res)
				RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
			return (NULL);
		}

		(*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
	}

	return (net_data);
}