su_addrinfo.c 20.1 KB
Newer Older
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
/*
 * 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
 * GAI_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 GAI_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 GAI_ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN GAI_ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <su_addrinfo.h>
#include <su.h>

#if !SU_HAVE_GETADDRINFO

#include <string.h>
#include <stddef.h>
#include <stdlib.h>
#include <ctype.h>

/*
 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
 *
 * Issues to be discussed:
 * - Thread safe-ness must be checked.
 * - Return values.  There are nonstandard return values defined and used
 *   in the source code.  This is because RFC2133 is silent about which error
 *   code must be returned for which situation.
 * - PF_UNSPEC case would be handled in getipnodebyname() with the AI_ALL flag.
 */

#if defined(__KAME__) && defined(INET6)
# define FAITH
#endif

#define SUCCESS 0
#define GAI_ANY 0
#define YES 1
#define NO  0

#undef SU_HAVE_IN6

#ifdef FAITH
static int translate = NO;
static struct in6_addr faith_prefix = IN6ADDR_GAI_ANY_INIT;
#endif

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
};

struct sockinet {
	u_char	si_len;
	u_char	si_family;
	u_short	si_port;
};

static struct gai_afd {
	int a_af;
	int a_addrlen;
	int a_socklen;
	int a_off;
	const char *a_addrany;
	const char *a_loopback;	
} gai_afdl [] = {
#if SU_HAVE_IN6
#define N_INET6 0
	{PF_INET6, sizeof(struct in6_addr),
	 sizeof(struct sockaddr_in6),
	 offsetof(struct sockaddr_in6, sin6_addr),
	 in6_addrany, in6_loopback},
#define N_INET  1
#else
#define N_INET  0
#endif
	{PF_INET, sizeof(struct in_addr),
	 sizeof(struct sockaddr_in),
	 offsetof(struct sockaddr_in, sin_addr),
	 in_addrany, in_loopback},
	{0, 0, 0, 0, NULL, NULL},
};

#if SU_HAVE_IN6
#define PTON_MAX	16
#else
#define PTON_MAX	4
#endif

#if SU_HAVE_IN6 && !defined(s6_addr8)
#  define s6_addr8 s6_addr
#endif

static int get_name(const char *, struct gai_afd *,
		    struct addrinfo **, char *, struct addrinfo *,
		    int);
static int get_addr(const char *, int, struct addrinfo **,
		    struct addrinfo *, int);
static int str_isnumber(const char *);
	
static 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        */
};

#define GET_CANONNAME(ai, str) \
if (pai->ai_flags & AI_CANONNAME) {\
	if (((ai)->ai_canonname = (char *)malloc(strlen(str) + 1)) != NULL) {\
		strcpy((ai)->ai_canonname, (str));\
	} else {\
		error = EAI_MEMORY;\
		goto free;\
	}\
}

#ifdef HAVE_SOCKADDR_SA_LEN
#define GET_AI(ai, gai_afd, addr, port) {\
	char *p;\
	if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
					      ((gai_afd)->a_socklen)))\
	    == NULL) goto free;\
	memcpy(ai, pai, sizeof(struct addrinfo));\
	(ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
	memset((ai)->ai_addr, 0, (gai_afd)->a_socklen);\
	(ai)->ai_addr->sa_len = (ai)->ai_addrlen = (gai_afd)->a_socklen;\
	(ai)->ai_addr->sa_family = (ai)->ai_family = (gai_afd)->a_af;\
	((struct sockinet *)(ai)->ai_addr)->si_port = port;\
	p = (char *)((ai)->ai_addr);\
	memcpy(p + (gai_afd)->a_off, (addr), (gai_afd)->a_addrlen);\
}
#else
#define GET_AI(ai, gai_afd, addr, port) {\
	char *p;\
	if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
					      ((gai_afd)->a_socklen)))\
	    == NULL) goto free;\
	memcpy(ai, pai, sizeof(struct addrinfo));\
	(ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
	memset((ai)->ai_addr, 0, (gai_afd)->a_socklen);\
	(ai)->ai_addr->sa_family = (ai)->ai_family = (gai_afd)->a_af;\
	((struct sockinet *)(ai)->ai_addr)->si_port = port;\
	p = (char *)((ai)->ai_addr);\
	memcpy(p + (gai_afd)->a_off, (addr), (gai_afd)->a_addrlen);\
}
#endif

#define ERR(err) { error = (err); goto bad; }

static 
char *
gai_strerror(ecode)
	int ecode;
{
	if (ecode < 0 || ecode > EAI_MAX)
		ecode = EAI_MAX;
	return ai_errlist[ecode];
}

static 
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);
	} while ((ai = next) != NULL);
}

static int
str_isnumber(p)
	const char *p;
{
	char *q = (char *)p;
	while (*q) {
		if (! isdigit(*q))
			return NO;
		q++;
	}
	return YES;
}

static
int
getaddrinfo(hostname, servname, hints, res)
	const char *hostname, *servname;
	const struct addrinfo *hints;
	struct addrinfo **res;
{
	struct addrinfo sentinel;
	struct addrinfo *top = NULL;
	struct addrinfo *cur;
	int i, error = 0;
	char pton[PTON_MAX];
	struct addrinfo ai;
	struct addrinfo *pai;
	u_short port;

#ifdef FAITH
	static int firsttime = 1;

	if (firsttime) {
		/* translator hack */
		{
			char *q = getenv("GAI");
			if (q && inet_pton(AF_INET6, q, &faith_prefix) == 1)
				translate = YES;
		}
		firsttime = 0;
	}
#endif

	/* initialize file static vars */
	sentinel.ai_next = NULL;
	cur = &sentinel;
	pai = &ai;
	pai->ai_flags = 0;
	pai->ai_family = PF_UNSPEC;
	pai->ai_socktype = GAI_ANY;
	pai->ai_protocol = GAI_ANY;
	pai->ai_addrlen = 0;
	pai->ai_canonname = NULL;
	pai->ai_addr = NULL;
	pai->ai_next = NULL;
	port = GAI_ANY;
	
	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)
			ERR(EAI_BADHINTS); /* xxx */
		if (hints->ai_flags & ~AI_MASK)
			ERR(EAI_BADFLAGS);
		switch (hints->ai_family) {
		case PF_UNSPEC:
		case PF_INET:
#if SU_HAVE_IN6
		case PF_INET6:
#endif
			break;
		default:
			ERR(EAI_FAMILY);
		}
		memcpy(pai, hints, sizeof(*pai));
		switch (pai->ai_socktype) {
		case GAI_ANY:
			switch (pai->ai_protocol) {
			case GAI_ANY:
				break;
			case IPPROTO_UDP:
				pai->ai_socktype = SOCK_DGRAM;
				break;
			case IPPROTO_TCP:
				pai->ai_socktype = SOCK_STREAM;
				break;
			default:
				pai->ai_socktype = SOCK_RAW;
				break;
			}
			break;
		case SOCK_RAW:
			break;
		case SOCK_DGRAM:
			if (pai->ai_protocol != IPPROTO_UDP &&
			    pai->ai_protocol != GAI_ANY)
				ERR(EAI_BADHINTS);	/*xxx*/
			pai->ai_protocol = IPPROTO_UDP;
			break;
		case SOCK_STREAM:
			if (pai->ai_protocol != IPPROTO_TCP &&
			    pai->ai_protocol != GAI_ANY)
				ERR(EAI_BADHINTS);	/*xxx*/
			pai->ai_protocol = IPPROTO_TCP;
			break;
		default:
			ERR(EAI_SOCKTYPE);
			break;
		}
	}

	/*
	 * service port
	 */
	if (servname) {
		if (str_isnumber(servname)) {
			if (pai->ai_socktype == GAI_ANY) {
				/* caller accept *GAI_ANY* socktype */
				pai->ai_socktype = SOCK_DGRAM;
				pai->ai_protocol = IPPROTO_UDP;
			}
			port = htons(atoi(servname));
		} else {
			struct servent *sp;
			char *proto;

			proto = NULL;
			switch (pai->ai_socktype) {
			case GAI_ANY:
				proto = NULL;
				break;
			case SOCK_DGRAM:
				proto = "udp";
				break;
			case SOCK_STREAM:
				proto = "tcp";
				break;
			default:
				fprintf(stderr, "panic!\n");
				break;
			}
			if ((sp = getservbyname(servname, proto)) == NULL)
				ERR(EAI_SERVICE);
			port = sp->s_port;
			if (pai->ai_socktype == GAI_ANY)
				if (strcmp(sp->s_proto, "udp") == 0) {
					pai->ai_socktype = SOCK_DGRAM;
					pai->ai_protocol = IPPROTO_UDP;
				} else if (strcmp(sp->s_proto, "tcp") == 0) {
					pai->ai_socktype = SOCK_STREAM;
					pai->ai_protocol = IPPROTO_TCP;
				} else
					ERR(EAI_PROTOCOL);	/*xxx*/
		}
	}
	
	/*
	 * hostname == NULL.
	 * passive socket -> anyaddr (0.0.0.0 or ::)
	 * non-passive socket -> localhost (127.0.0.1 or ::1)
	 */
	if (hostname == NULL) {
		struct gai_afd *gai_afd;

		for (gai_afd = &gai_afdl[0]; gai_afd->a_af; gai_afd++) {
			if (!(pai->ai_family == PF_UNSPEC
			   || pai->ai_family == gai_afd->a_af)) {
				continue;
			}

			if (pai->ai_flags & AI_PASSIVE) {
				GET_AI(cur->ai_next, gai_afd, gai_afd->a_addrany, port);
				/* xxx meaningless?
				 * GET_CANONNAME(cur->ai_next, "anyaddr");
				 */
			} else {
				GET_AI(cur->ai_next, gai_afd, gai_afd->a_loopback,
					port);
				/* xxx meaningless?
				 * GET_CANONNAME(cur->ai_next, "localhost");
				 */
			}
			cur = cur->ai_next;
		}
		top = sentinel.ai_next;
		if (top)
			goto good;
		else
			ERR(EAI_FAMILY);
	}
	
	/* hostname as numeric name */
	for (i = 0; gai_afdl[i].a_af; i++) {
		if (inet_pton(gai_afdl[i].a_af, hostname, pton)) {
			u_long v4a;
			u_char pfx;

			switch (gai_afdl[i].a_af) {
			case AF_INET:
				v4a = ((struct in_addr *)pton)->s_addr;
				if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
					pai->ai_flags &= ~AI_CANONNAME;
				v4a >>= IN_CLASSA_NSHIFT;
				if (v4a == 0 || v4a == IN_LOOPBACKNET)
					pai->ai_flags &= ~AI_CANONNAME;
				break;
#if SU_HAVE_IN6
			case AF_INET6:
				pfx = ((struct in6_addr *)pton)->s6_addr8[0];
				if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
					pai->ai_flags &= ~AI_CANONNAME;
				break;
#endif
			}
			
			if (pai->ai_family == gai_afdl[i].a_af ||
			    pai->ai_family == PF_UNSPEC) {
				if (! (pai->ai_flags & AI_CANONNAME)) {
					GET_AI(top, &gai_afdl[i], pton, port);
					goto good;
				}
				/*
				 * if AI_CANONNAME and if reverse lookup
				 * fail, return ai anyway to pacify
				 * calling application.
				 *
				 * XXX getaddrinfo() is a name->address
				 * translation function, and it looks strange
				 * that we do addr->name translation here.
				 */
				get_name(pton, &gai_afdl[i], &top, pton, pai, port);
				goto good;
			} else 
				ERR(EAI_FAMILY);	/*xxx*/
		}
	}

	if (pai->ai_flags & AI_NUMERICHOST)
		ERR(EAI_NONAME);

	/* hostname as alphabetical name */
	error = get_addr(hostname, pai->ai_family, &top, pai, port);
	if (error == 0) {
		if (top) {
 good:
			*res = top;
			return SUCCESS;
		} else
			error = EAI_FAIL;
	}
 free:
	if (top)
		freeaddrinfo(top);
 bad:
	*res = NULL;
	return error;
}

static int
get_name(addr, gai_afd, res, numaddr, pai, port0)
	const char *addr;
	struct gai_afd *gai_afd;
	struct addrinfo **res;
	char *numaddr;
	struct addrinfo *pai;
	int port0;
{
	u_short port = port0 & 0xffff;
	struct hostent *hp;
	struct addrinfo *cur;
	int error = 0, h_error;
	
#if SU_HAVE_IN6
	hp = getipnodebyaddr(addr, gai_afd->a_addrlen, gai_afd->a_af, &h_error);
#else
	hp = gethostbyaddr(addr, gai_afd->a_addrlen, AF_INET);
#endif
	if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
		GET_AI(cur, gai_afd, hp->h_addr_list[0], port);
		GET_CANONNAME(cur, hp->h_name);
	} else
		GET_AI(cur, gai_afd, numaddr, port);
	
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
	*res = cur;
	return SUCCESS;
 free:
	if (cur)
		freeaddrinfo(cur);
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
 /* bad: */
	*res = NULL;
	return error;
}

static int
get_addr(hostname, af, res, pai, port0)
	const char *hostname;
	int af;
	struct addrinfo **res;
	struct addrinfo *pai;
	int port0;
{
	u_short port = port0 & 0xffff;
	struct addrinfo sentinel;
	struct hostent *hp;
	struct addrinfo *top, *cur;
	struct gai_afd *gai_afd;
	int i, error = 0, h_error;
	char *ap;
#ifndef INET6
	extern int h_errno;
#endif

	top = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;
#if SU_HAVE_IN6
	if (af == AF_UNSPEC) {
		hp = getipnodebyname(hostname, AF_INET6,
				AI_ADDRCONFIG|AI_ALL|AI_V4MAPPED, &h_error);
	} else
		hp = getipnodebyname(hostname, af, AI_ADDRCONFIG, &h_error);
#else
	hp = gethostbyname(hostname);
	h_error = h_errno;
#endif
	if (hp == NULL) {
		switch (h_error) {
		case HOST_NOT_FOUND:
		case NO_DATA:
			error = EAI_NODATA;
			break;
		case TRY_AGAIN:
			error = EAI_AGAIN;
			break;
		case NO_RECOVERY:
		default:
			error = EAI_FAIL;
			break;
		}
		goto bad;
	}

	if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
	    (hp->h_addr_list[0] == NULL))
		ERR(EAI_FAIL);
	
	for (i = 0; (ap = hp->h_addr_list[i]) != NULL; i++) {
		switch (af) {
#if SU_HAVE_IN6
		case AF_INET6:
			gai_afd = &gai_afdl[N_INET6];
			break;
#endif
#ifndef INET6
		default:	/* AF_UNSPEC */
#endif
		case AF_INET:
			gai_afd = &gai_afdl[N_INET];
			break;
#if SU_HAVE_IN6
		default:	/* AF_UNSPEC */
			if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
				ap += sizeof(struct in6_addr) -
					sizeof(struct in_addr);
				gai_afd = &gai_afdl[N_INET];
			} else
				gai_afd = &gai_afdl[N_INET6];
			break;
#endif
		}
#ifdef FAITH
		if (translate && gai_afd->a_af == AF_INET) {
			struct in6_addr *in6;

			GET_AI(cur->ai_next, &gai_afdl[N_INET6], ap, port);
			in6 = &((struct sockaddr_in6 *)cur->ai_next->ai_addr)->sin6_addr;
			memcpy(&in6->s6_addr32[0], &faith_prefix,
			    sizeof(struct in6_addr) - sizeof(struct in_addr));
			memcpy(&in6->s6_addr32[3], ap, sizeof(struct in_addr));
		} else
#endif /* FAITH */
		GET_AI(cur->ai_next, gai_afd, ap, port);
		if (cur == &sentinel) {
			top = cur->ai_next;
			GET_CANONNAME(top, hp->h_name);
		}
		cur = cur->ai_next;
	}
#if SU_HAVE_IN6
	freehostent(hp);
#endif
	*res = top;
	return SUCCESS;
 free:
	if (top)
		freeaddrinfo(top);
#if SU_HAVE_IN6
	if (hp)
		freehostent(hp);
#endif
 bad:
	*res = NULL;
	return error;
}

/*
 * Issues to be discussed:
 * - Thread safe-ness must be checked
 * - Return values.  There seems to be no standard for return value (RFC2133)
 *   but INRIA implementation returns EAI_xxx defined for getaddrinfo().
 */

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

static struct gni_afd {
	int a_af;
	int a_addrlen;
	int a_socklen;
	int a_off;
} gni_afdl [] = {
#if SU_HAVE_IN6
	{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
		offsetof(struct sockaddr_in6, sin6_addr)},
#endif
	{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
		offsetof(struct sockaddr_in, sin_addr)},
	{0, 0, 0},
};

struct gni_sockinet {
	u_char	si_len;
	u_char	si_family;
	u_short	si_port;
};

#define ENI_NOSOCKET 	0
#define ENI_NOSERVNAME	1
#define ENI_NOHOSTNAME	2
#define ENI_MEMORY	3
#define ENI_SYSTEM	4
#define ENI_FAMILY	5
#define ENI_SALEN	6

static
int
getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
	const struct sockaddr *sa;
	size_t salen;
	char *host;
	size_t hostlen;
	char *serv;
	size_t servlen;
	int flags;
{
	struct gni_afd *gni_afd;
	struct servent *sp;
	struct hostent *hp;
	u_short port;
	int family, len, i;
	char *addr, *p;
	u_long v4a;
	u_char pfx;
	int h_error;
	char numserv[512];
	char numaddr[512];

	if (sa == NULL)
		return ENI_NOSOCKET;

#ifdef HAVE_SOCKADDR_SA_LEN
	len = sa->sa_len;
	if (len != salen) return ENI_SALEN;
#else
	len = salen;
#endif
	
	family = sa->sa_family;
	for (i = 0; gni_afdl[i].a_af; i++)
		if (gni_afdl[i].a_af == family) {
			gni_afd = &gni_afdl[i];
			goto found;
		}
	return ENI_FAMILY;
	
 found:
	if (len != gni_afd->a_socklen) return ENI_SALEN;
	
	port = ((struct gni_sockinet *)sa)->si_port; /* network byte order */
	addr = (char *)sa + gni_afd->a_off;

	if (serv == NULL || servlen == 0) {
		/* what we should do? */
	} else if (flags & NI_NUMERICSERV) {
		snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
		if (strlen(numserv) > servlen)
			return ENI_MEMORY;
		strcpy(serv, numserv);
	} else {
		sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
		if (sp) {
			if (strlen(sp->s_name) > servlen)
				return ENI_MEMORY;
			strcpy(serv, sp->s_name);
		} else
			return ENI_NOSERVNAME;
	}

	switch (sa->sa_family) {
	case AF_INET:
		v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
		if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
			flags |= NI_NUMERICHOST;
		v4a >>= IN_CLASSA_NSHIFT;
		if (v4a == 0 || v4a == IN_LOOPBACKNET)
			flags |= NI_NUMERICHOST;			
		break;
#if SU_HAVE_IN6
	case AF_INET6:
		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr8[0];
		if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
			flags |= NI_NUMERICHOST;
		break;
#endif
	}
	if (host == NULL || hostlen == 0) {
		/* what should we do? */
	} else if (flags & NI_NUMERICHOST) {
		if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
		    == NULL)
			return ENI_SYSTEM;
		if (strlen(numaddr) > hostlen)
			return ENI_MEMORY;
		strcpy(host, numaddr);
	} else {
#if SU_HAVE_IN6
		hp = getipnodebyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af, &h_error);
#else
		hp = gethostbyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af);
		h_error = h_errno;
#endif

		if (hp) {
			if (flags & NI_NOFQDN) {
				p = strchr(hp->h_name, '.');
				if (p) *p = '\0';
			}
			if (strlen(hp->h_name) > hostlen) {
#if SU_HAVE_IN6
				freehostent(hp);
#endif
				return ENI_MEMORY;
			}
			strcpy(host, hp->h_name);
#if SU_HAVE_IN6
			freehostent(hp);
#endif
		} else {
			if (flags & NI_NAMEREQD)
				return ENI_NOHOSTNAME;
			if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
			    == NULL)
				return ENI_NOHOSTNAME;
			if (strlen(numaddr) > hostlen)
				return ENI_MEMORY;
			strcpy(host, numaddr);
		}
	}
	return SUCCESS;
}

#endif	/* SU_WITH_GETADDRINFO */

/** Translate address and service.
 *
 * This is a getaddrinfo() supporting SCTP and other exotic protocols.
 */
int su_getaddrinfo(char const *node, char const *service,
		   su_addrinfo_t const *hints,
		   su_addrinfo_t **res)
{
#if HAVE_SCTP
  if (res && hints && hints->ai_protocol == IPPROTO_SCTP) {
    su_addrinfo_t *ai, system_hints[1];
    int retval, socktype;

    socktype = hints->ai_socktype;
    
    if (!(socktype == 0 ||
	  socktype == SOCK_SEQPACKET ||
	  socktype == SOCK_STREAM ||
	  socktype == SOCK_DGRAM))
      return EAI_SOCKTYPE;

    *system_hints = *hints;
    system_hints->ai_protocol = IPPROTO_TCP;
    system_hints->ai_socktype = SOCK_STREAM;

    retval = getaddrinfo(node, service, system_hints, res);
    if (retval)
      return retval;

    if (socktype == 0)
      socktype = SOCK_STREAM;

    for (ai = *res; ai; ai = ai->ai_next) {
      ai->ai_protocol = IPPROTO_SCTP;
      ai->ai_socktype = socktype;
    }

    return 0;
  }
#endif

  return getaddrinfo(node, service, hints, res);
}

/** Free su_addrinfo_t structure allocated by su_getaddrinfo(). */
void su_freeaddrinfo(su_addrinfo_t *res)
{
  freeaddrinfo(res);
}

/** Return string describing address translation error. */
char const *su_gai_strerror(int errcode)
{
  return gai_strerror(errcode);
}

/** Resolve socket address into hostname and service name */
int
su_getnameinfo(const su_sockaddr_t *su, size_t sulen,
	       char *return_host, size_t hostlen,
	       char *return_serv, size_t servlen,
	       int flags)
{
  return getnameinfo(&su->su_sa, sulen, 
		     return_host, hostlen, 
		     return_serv, servlen, 
		     flags);
}