/* $USAGI: getaddrinfo.c,v 1.16 2001/10/04 09:52:03 sekiya Exp $ */

/* The Inner Net License, Version 2.00

  The author(s) grant permission for redistribution and use in source and
binary forms, with or without modification, of the software and documentation
provided that the following conditions are met:

0. If you receive a version of the software that is specifically labelled
   as not being for redistribution (check the version message and/or README),
   you are not permitted to redistribute that version of the software in any
   way or form.
1. All terms of the all other applicable copyrights and licenses must be
   followed.
2. Redistributions of source code must retain the authors' copyright
   notice(s), this list of conditions, and the following disclaimer.
3. Redistributions in binary form must reproduce the authors' copyright
   notice(s), this list of conditions, and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
4. All advertising materials mentioning features or use of this software
   must display the following acknowledgement with the name(s) of the
   authors as specified in the copyright notice(s) substituted where
   indicated:

	This product includes software developed by <name(s)>, The Inner
	Net, and other contributors.

5. Neither the name(s) of the author(s) 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 ITS AUTHORS 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 AUTHORS 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.

  If these license terms cause you a real problem, contact the author.  */

/* This software is Copyright 1996 by Craig Metz, All Rights Reserved.  */

#include <config.h>
#include "owfs_config.h"

#ifdef HAVE_PTHREAD
#include <pthread.h>
#endif

#ifndef HAVE_GETADDRINFO

#define _GNU_SOURCE 1
#define __FORCE_GLIBC
#ifdef HAVE_FEATURES_H
#include <features.h>
#endif
#include <assert.h>
#include <errno.h>
#include <netdb.h>
#include "compat_netdb.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/utsname.h>
#include <net/if.h>

#ifdef HAVE_RESOLV_H
#include <resolv.h>
#endif

#include "ow_debug.h"
#include "ow_alloc.h"

/* The following declarations and definitions have been removed from
 *    the public header since we don't want people to use them.  */
#define AI_V4MAPPED     0x0008	/* IPv4-mapped addresses are acceptable.  */
#define AI_ALL          0x0010	/* Return both IPv4 and IPv6 addresses.  */
#define AI_ADDRCONFIG   0x0020	/* Use configuration of this host to choose
								   returned address type.  */
#define AI_DEFAULT    (AI_V4MAPPED | AI_ADDRCONFIG)


#define GAIH_OKIFUNSPEC 0x0100
#define GAIH_EAI        ~(GAIH_OKIFUNSPEC)

struct gaih_service {
	const char *name;
	int num;
};

struct gaih_servtuple {
	struct gaih_servtuple *next;
	int socktype;
	int protocol;
	int port;
};

static const struct gaih_servtuple nullserv;

struct gaih_addrtuple {
	struct gaih_addrtuple *next;
	int family;
	char addr[16];
	uint32_t scopeid;
};

struct gaih_typeproto {
	int socktype;
	int protocol;
	char name[4];
	int protoflag;
};

/* Values for `protoflag'.  */
#define GAI_PROTO_NOSERVICE	1
#define GAI_PROTO_PROTOANY	2

static const struct gaih_typeproto gaih_inet_typeproto[] = {
	{0, 0, "", 0},
	{SOCK_STREAM, IPPROTO_TCP, "tcp", 0},
	{SOCK_DGRAM, IPPROTO_UDP, "udp", 0},
	{SOCK_RAW, 0, "raw", GAI_PROTO_PROTOANY | GAI_PROTO_NOSERVICE},
	{0, 0, "", 0}
};

struct gaih {
	int family;
	int (*gaih) (const char *name, const struct gaih_service * service, const struct addrinfo * req, struct addrinfo ** pai);
};

#if PF_UNSPEC == 0
static const struct addrinfo default_hints;
#else
static const struct addrinfo default_hints = { 0, PF_UNSPEC, 0, 0, 0, NULL, NULL, NULL };
#endif


static int addrconfig(sa_family_t af)
{
	int s;
	int ret;
	int saved_errno = errno;
	s = socket(af, SOCK_DGRAM, 0);
	if (s < 0)
		ret = (errno == EMFILE) ? 1 : 0;
	else {
		close(s);
		ret = 1;
	}
	__set_errno(saved_errno);
	return ret;
}

#if 0
#ifndef UNIX_PATH_MAX
#define UNIX_PATH_MAX  108
#endif

/* Using Unix sockets this way is a security risk.  */
static int gaih_local(const char *name, const struct gaih_service *service, const struct addrinfo *req, struct addrinfo **pai)
{
	struct utsname utsname;

	if ((name != NULL) && (req->ai_flags & AI_NUMERICHOST))
		return GAIH_OKIFUNSPEC | -EAI_NONAME;

	if ((name != NULL) || (req->ai_flags & AI_CANONNAME))
		if (uname(&utsname) < 0)
			return -EAI_SYSTEM;

	if (name != NULL) {
		if (strcmp(name, "localhost") && strcmp(name, "local") && strcmp(name, "unix") && strcmp(name, utsname.nodename))
			return GAIH_OKIFUNSPEC | -EAI_NONAME;
	}

	if (req->ai_protocol || req->ai_socktype) {
		const struct gaih_typeproto *tp = gaih_inet_typeproto + 1;

		while (tp->name[0]
			   && ((tp->protoflag & GAI_PROTO_NOSERVICE) != 0 || (req->ai_socktype != 0 && req->ai_socktype != tp->socktype)
				   || (req->ai_protocol != 0 && !(tp->protoflag & GAI_PROTO_PROTOANY)
					   && req->ai_protocol != tp->protocol)))
			++tp;

		if (!tp->name[0]) {
			if (req->ai_socktype)
				return (GAIH_OKIFUNSPEC | -EAI_SOCKTYPE);
			else
				return (GAIH_OKIFUNSPEC | -EAI_SERVICE);
		}
	}

	*pai = owmalloc(sizeof(struct addrinfo) + sizeof(struct sockaddr_un)
				  + ((req->ai_flags & AI_CANONNAME)
					 ? (strlen(utsname.nodename) + 1) : 0));
	if (*pai == NULL)
		return -EAI_MEMORY;

	(*pai)->ai_next = NULL;
	(*pai)->ai_flags = req->ai_flags;
	(*pai)->ai_family = AF_LOCAL;
	(*pai)->ai_socktype = req->ai_socktype ? req->ai_socktype : SOCK_STREAM;
	(*pai)->ai_protocol = req->ai_protocol;
	(*pai)->ai_addrlen = sizeof(struct sockaddr_un);
	(*pai)->ai_addr = (void *) (*pai) + sizeof(struct addrinfo);

#ifdef HAVE_SA_LEN
	((struct sockaddr_un *) (*pai)->ai_addr)->sun_len = sizeof(struct sockaddr_un);
#endif							/* HAVE_SA_LEN */

	((struct sockaddr_un *) (*pai)->ai_addr)->sun_family = AF_LOCAL;
	memset(((struct sockaddr_un *) (*pai)->ai_addr)->sun_path, 0, UNIX_PATH_MAX);

	if (service) {
		struct sockaddr_un *sunp = (struct sockaddr_un *) (*pai)->ai_addr;

		if (strchr(service->name, '/') != NULL) {
			if (strlen(service->name) >= sizeof(sunp->sun_path))
				return GAIH_OKIFUNSPEC | -EAI_SERVICE;

			strcpy(sunp->sun_path, service->name);
		} else {
			if (strlen(P_tmpdir "/") + 1 + strlen(service->name) >= sizeof(sunp->sun_path))
				return GAIH_OKIFUNSPEC | -EAI_SERVICE;

			__stpcpy(__stpcpy(sunp->sun_path, P_tmpdir "/"), service->name);
		}
	} else {
		/* This is a dangerous use of the interface since there is a time
		   window between the test for the file and the actual creation
		   (done by the caller) in which a file with the same name could
		   be created.  */
		char *buf = ((struct sockaddr_un *) (*pai)->ai_addr)->sun_path;

		if (__builtin_expect(__path_search(buf, L_tmpnam, NULL, NULL, 0), 0) != 0 || __builtin_expect(__gen_tempname(buf, __GT_NOCREATE), 0) != 0)
			return -EAI_SYSTEM;
	}

	if (req->ai_flags & AI_CANONNAME)
		(*pai)->ai_canonname = strcpy((char *) *pai + sizeof(struct addrinfo)
									  + sizeof(struct sockaddr_un), utsname.nodename);
	else
		(*pai)->ai_canonname = NULL;
	return 0;
}
#endif							/* 0 */

#ifndef HAVE_GETHOSTBYNAME_R
struct hostent *gethostbyname_r(const char *name, struct hostent *result, char *buf, size_t buflen, int *h_errnop)
{
#ifdef HAVE_PTHREAD
	static pthread_mutex_t gethostbyname_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
	struct hostent *res;
	(void) buf;					// not used
	(void) buflen;				// not used

#ifdef HAVE_PTHREAD
	_MUTEX_LOCK(gethostbyname_lock);
#endif
	res = gethostbyname(name);
	if (res) {
		memcpy(result, res, sizeof(struct hostent));
	} else {
		*h_errnop = errno;
	}
#ifdef HAVE_PTHREAD
	_MUTEX_UNLOCK(gethostbyname_lock);
#endif
	return res;
}
#endif

#ifndef HAVE_GETSERVBYNAME_R
struct servent *getservbyname_r(const char *name, const char *proto, struct servent *result, char *buf, size_t buflen)
{
#ifdef HAVE_PTHREAD
	static pthread_mutex_t getservbyname_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
	struct servent *res;
	(void) buf;					// not used
	(void) buflen;				// not used

#ifdef HAVE_PTHREAD
	_MUTEX_LOCK(getservbyname_lock);
#endif
	res = getservbyname(name, proto);
	if (res)
		memcpy(result, res, sizeof(struct servent));
#ifdef HAVE_PTHREAD
	_MUTEX_UNLOCK(getservbyname_lock);
#endif
	return res;
}
#endif





static int gaih_inet_serv(const char *servicename, const struct gaih_typeproto *tp, const struct addrinfo *req, struct gaih_servtuple *st)
{
	struct servent *s;
	size_t tmpbuflen = 1024;
	struct servent ts;
	char *tmpbuf;
	int r;

	do {
		tmpbuf = alloca(tmpbuflen);
#if 0
		r = getservbyname_r(servicename, tp->name, &ts, tmpbuf, tmpbuflen, &s);
		if (!s)
			r = errno;
		if (r != 0 || s == NULL) {
			if (r == ERANGE)
				tmpbuflen *= 2;
			else
				return GAIH_OKIFUNSPEC | -EAI_SERVICE;
		}
#else
		s = getservbyname_r(servicename, tp->name, &ts, tmpbuf, tmpbuflen);
		if (s == NULL) {
			r = errno;
			if (r == ERANGE)
				tmpbuflen *= 2;
			else
				return GAIH_OKIFUNSPEC | -EAI_SERVICE;
		} else {
			r = 0;
		}
#endif
	}
	while (r);

	st->next = NULL;
	st->socktype = tp->socktype;
	st->protocol = ((tp->protoflag & GAI_PROTO_PROTOANY)
					? req->ai_protocol : tp->protocol);
	st->port = s->s_port;

	return 0;
}

#define gethosts(_family, _type)					\
{									\
    int i, herrno;							\
    size_t tmpbuflen;							\
    struct hostent th;							\
    char *tmpbuf;							\
    tmpbuflen = 512;							\
    no_data = 0;							\
    do {								\
	tmpbuflen *= 2;							\
	tmpbuf = alloca (tmpbuflen);					\
        rc = 0;								\
	h = gethostbyname_r (name, &th, tmpbuf,				\
			       tmpbuflen, &herrno);			\
        if(!h) rc = errno;						\
    } while (rc == ERANGE && herrno == NETDB_INTERNAL);			\
    if (rc != 0)							\
    {									\
	if (herrno == NETDB_INTERNAL)					\
	{								\
	    __set_h_errno (herrno);					\
		return -EAI_SYSTEM;					\
	}								\
	if (herrno == TRY_AGAIN)					\
	    no_data = EAI_AGAIN;					\
	else								\
	    no_data = herrno == NO_DATA;				\
    }									\
    else if (h != NULL)							\
    {									\
	for (i = 0; h->h_addr_list[i]; i++)				\
	{								\
	    if (*pat == NULL) {						\
		*pat = alloca (sizeof(struct gaih_addrtuple));		\
		    (*pat)->scopeid = 0;				\
	    }								\
	    (*pat)->next = NULL;					\
		(*pat)->family = _family;				\
		memcpy ((*pat)->addr, h->h_addr_list[i],		\
			sizeof(_type));					\
		pat = &((*pat)->next);					\
	}								\
    }									\
}

#ifndef HAVE_GETHOSTBYNAME2_R
struct hostenv *gethostbyname2_r(const char *name, int af, struct hostent *ret, char *buf, size_t buflen, struct hostent **result, int *h_errnop)
{
	/* Don't support this if it doesn't exists...
	   (eg. IPV6 will fail on cygwin for example) */
	(void) name;
	(void) af;
	(void) ret;
	(void) buf;
	(void) buflen;
	(void) result;
	(void) h_errnop;
	return NULL;
}
#endif


#if __HAS_IPV6__
#define gethosts2(_family, _type)					\
{									\
    int i, herrno;							\
    size_t tmpbuflen;							\
    struct hostent th;							\
    char *tmpbuf;							\
    tmpbuflen = 512;							\
    no_data = 0;							\
    do {								\
	tmpbuflen *= 2;							\
	tmpbuf = alloca (tmpbuflen);					\
	rc = gethostbyname2_r (name, _family, &th, tmpbuf,		\
			       tmpbuflen, &h, &herrno);			\
    } while (rc == ERANGE && herrno == NETDB_INTERNAL);			\
    if (rc != 0)							\
    {									\
	if (herrno == NETDB_INTERNAL)					\
	{								\
	    __set_h_errno (herrno);					\
		return -EAI_SYSTEM;					\
	}								\
	if (herrno == TRY_AGAIN)					\
	    no_data = EAI_AGAIN;					\
	else								\
	    no_data = herrno == NO_DATA;				\
    }									\
    else if (h != NULL)							\
    {									\
	for (i = 0; h->h_addr_list[i]; i++)				\
	{								\
	    if (*pat == NULL) {						\
		*pat = alloca (sizeof(struct gaih_addrtuple));		\
		    (*pat)->scopeid = 0;				\
	    }								\
	    (*pat)->next = NULL;					\
		(*pat)->family = _family;				\
		memcpy ((*pat)->addr, h->h_addr_list[i],		\
			sizeof(_type));					\
		pat = &((*pat)->next);					\
	}								\
    }									\
}
#endif

#ifndef HAVE_GETHOSTBYADDR_R
struct hostent *gethostbyaddr_r(const char *name, int len, int type, struct hostent *result, char *buf, size_t buflen, int *h_errnop)
{
#ifdef HAVE_PTHREAD
	static pthread_mutex_t gethostbyaddr_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
	struct hostent *res;
	(void) buf;					// not used
	(void) buflen;				// not used

#ifdef HAVE_PTHREAD
	_MUTEX_LOCK(gethostbyaddr_lock);
#endif
	res = gethostbyaddr(name, len, type);
	if (res) {
		memcpy(result, res, sizeof(struct hostent));
	} else {
		*h_errnop = errno;
	}
#ifdef HAVE_PTHREAD
	_MUTEX_UNLOCK(gethostbyaddr_lock);
#endif
	return res;
}
#endif

static int gaih_inet(const char *name, const struct gaih_service *service, const struct addrinfo *req, struct addrinfo **pai)
{
	const struct gaih_typeproto *tp = gaih_inet_typeproto;
	struct gaih_servtuple *st = (struct gaih_servtuple *) &nullserv;
	struct gaih_addrtuple *at = NULL;
	int rc;
	int v4mapped = (req->ai_family == PF_UNSPEC
#if __HAS_IPV6__
					|| req->ai_family == PF_INET6
#endif
		) && (req->ai_flags & AI_V4MAPPED);

	if (req->ai_protocol || req->ai_socktype) {
		++tp;

		while (tp->name[0]
			   && ((req->ai_socktype != 0 && req->ai_socktype != tp->socktype)
				   || (req->ai_protocol != 0 && !(tp->protoflag & GAI_PROTO_PROTOANY)
					   && req->ai_protocol != tp->protocol)))
			++tp;

		if (!tp->name[0]) {
			if (req->ai_socktype)
				return (GAIH_OKIFUNSPEC | -EAI_SOCKTYPE);
			else
				return (GAIH_OKIFUNSPEC | -EAI_SERVICE);
		}
	}

	if (service != NULL) {
		if ((tp->protoflag & GAI_PROTO_NOSERVICE) != 0)
			return (GAIH_OKIFUNSPEC | -EAI_SERVICE);

		if (service->num < 0) {
			if (tp->name[0]) {
				st = (struct gaih_servtuple *)
					alloca(sizeof(struct gaih_servtuple));

				if ((rc = gaih_inet_serv(service->name, tp, req, st)))
					return rc;
			} else {
				struct gaih_servtuple **pst = &st;
				for (tp++; tp->name[0]; tp++) {
					struct gaih_servtuple *newp;

					if ((tp->protoflag & GAI_PROTO_NOSERVICE) != 0)
						continue;

					if (req->ai_socktype != 0 && req->ai_socktype != tp->socktype)
						continue;
					if (req->ai_protocol != 0 && !(tp->protoflag & GAI_PROTO_PROTOANY)
						&& req->ai_protocol != tp->protocol)
						continue;

					newp = (struct gaih_servtuple *)
						alloca(sizeof(struct gaih_servtuple));

					if ((rc = gaih_inet_serv(service->name, tp, req, newp))) {
						if (rc & GAIH_OKIFUNSPEC)
							continue;
						return rc;
					}

					*pst = newp;
					pst = &(newp->next);
				}
				if (st == (struct gaih_servtuple *) &nullserv)
					return (GAIH_OKIFUNSPEC | -EAI_SERVICE);
			}
		} else {
			st = alloca(sizeof(struct gaih_servtuple));
			st->next = NULL;
			st->socktype = tp->socktype;
			st->protocol = ((tp->protoflag & GAI_PROTO_PROTOANY)
							? req->ai_protocol : tp->protocol);
			st->port = htons(service->num);
		}
	} else if (req->ai_socktype || req->ai_protocol) {
		st = alloca(sizeof(struct gaih_servtuple));
		st->next = NULL;
		st->socktype = tp->socktype;
		st->protocol = ((tp->protoflag & GAI_PROTO_PROTOANY)
						? req->ai_protocol : tp->protocol);
		st->port = 0;
	} else {
		/*
		 * Neither socket type nor protocol is set.  Return all socket types
		 * we know about.
		 */
		struct gaih_servtuple **lastp = &st;
		for (++tp; tp->name[0]; ++tp) {
			struct gaih_servtuple *newp;

			newp = alloca(sizeof(struct gaih_servtuple));
			newp->next = NULL;
			newp->socktype = tp->socktype;
			newp->protocol = tp->protocol;
			newp->port = 0;

			*lastp = newp;
			lastp = &newp->next;
		}
	}

	if (name != NULL) {
		at = alloca(sizeof(struct gaih_addrtuple));

		at->family = AF_UNSPEC;
		at->scopeid = 0;
		at->next = NULL;

		if (inet_pton(AF_INET, name, at->addr) > 0) {
			if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET || v4mapped)
				at->family = AF_INET;
			else
				return -EAI_FAMILY;
		}
#if __HAS_IPV6__
		if (at->family == AF_UNSPEC) {
			char *namebuf = strdupa(name);
			char *scope_delim;

			scope_delim = strchr(namebuf, SCOPE_DELIMITER);
			if (scope_delim != NULL)
				*scope_delim = '\0';

			if (inet_pton(AF_INET6, namebuf, at->addr) > 0) {
				if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
					at->family = AF_INET6;
				else
					return -EAI_FAMILY;

				if (scope_delim != NULL) {
					int try_numericscope = 0;
					if (IN6_IS_ADDR_LINKLOCAL(at->addr)
						|| IN6_IS_ADDR_MC_LINKLOCAL(at->addr)) {
						at->scopeid = if_nametoindex(scope_delim + 1);
						if (at->scopeid == 0)
							try_numericscope = 1;
					} else
						try_numericscope = 1;

					if (try_numericscope != 0) {
						char *end;
						assert(sizeof(uint32_t) <= sizeof(unsigned long));
						at->scopeid = (uint32_t) strtoul(scope_delim + 1, &end, 10);
						if (*end != '\0')
							return GAIH_OKIFUNSPEC | -EAI_NONAME;
					}
				}
			}
		}
#endif

		if (at->family == AF_UNSPEC && (req->ai_flags & AI_NUMERICHOST) == 0) {
			struct hostent *h;
			struct gaih_addrtuple **pat = &at;
			int no_data = 0;
			int no_inet6_data;

			/*
			 * If we are looking for both IPv4 and IPv6 address we don't want
			 * the lookup functions to automatically promote IPv4 addresses to
			 * IPv6 addresses.
			 */

#if __HAS_IPV6__
			if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
				gethosts(AF_INET6, struct in6_addr);
#endif
			no_inet6_data = no_data;

			if (req->ai_family == AF_INET ||
				(!v4mapped && req->ai_family == AF_UNSPEC) || (v4mapped && (no_inet6_data != 0 || (req->ai_flags & AI_ALL))))
#if __HAS_IPV6__
				gethosts2(AF_INET, struct in_addr);
#else
				gethosts(AF_INET, struct in_addr);
#endif
			if (no_data != 0 && no_inet6_data != 0) {
				/* If both requests timed out report this. */
				if (no_data == EAI_AGAIN && no_inet6_data == EAI_AGAIN)
					return -EAI_AGAIN;

				/*
				 * We made requests but they turned out no data.
				 * The name is known, though.
				 */
				return (GAIH_OKIFUNSPEC | -EAI_AGAIN);
			}
		}

		if (at->family == AF_UNSPEC)
			return (GAIH_OKIFUNSPEC | -EAI_NONAME);
	} else {
		struct gaih_addrtuple *atr;
		atr = at = alloca(sizeof(struct gaih_addrtuple));
		memset(at, '\0', sizeof(struct gaih_addrtuple));

		if (req->ai_family == 0) {
			at->next = alloca(sizeof(struct gaih_addrtuple));
			memset(at->next, '\0', sizeof(struct gaih_addrtuple));
		}
#if __HAS_IPV6__
		if (req->ai_family == 0 || req->ai_family == AF_INET6) {
			extern const struct in6_addr __in6addr_loopback;
			at->family = AF_INET6;
			if ((req->ai_flags & AI_PASSIVE) == 0)
				memcpy(at->addr, &__in6addr_loopback, sizeof(struct in6_addr));
			atr = at->next;
		}
#endif

		if (req->ai_family == 0 || req->ai_family == AF_INET) {
			atr->family = AF_INET;
			if ((req->ai_flags & AI_PASSIVE) == 0)
				*(uint32_t *) atr->addr = htonl(INADDR_LOOPBACK);
		}
	}

	if (pai == NULL)
		return 0;

	{
		const char *c = NULL;
		struct gaih_servtuple *st2;
		struct gaih_addrtuple *at2 = at;
		size_t socklen, namelen;
		sa_family_t family;

		/*
		 * buffer is the size of an unformatted IPv6 address in
		 * printable format.
		 */
		char buffer[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];

		while (at2 != NULL) {
			if (req->ai_flags & AI_CANONNAME) {
				struct hostent *h = NULL;

				int herrno;
				struct hostent th;
				size_t tmpbuflen = 512;
				char *tmpbuf;

				do {
					tmpbuflen *= 2;
					tmpbuf = alloca(tmpbuflen);

					if (tmpbuf == NULL)
						return -EAI_MEMORY;

					rc = 0;
					h = gethostbyaddr_r(at2->addr,
#if __HAS_IPV6__
										((at2->family == AF_INET6)
										 ? sizeof(struct in6_addr)
										 : sizeof(struct in_addr)),
#else
										sizeof(struct in_addr),
#endif
										at2->family, &th, tmpbuf, tmpbuflen, &herrno);

					if (!h)
						rc = errno;
				}
				while (rc == errno && herrno == NETDB_INTERNAL);

				if (rc != 0 && herrno == NETDB_INTERNAL) {
					__set_h_errno(herrno);
					return -EAI_SYSTEM;
				}

				if (h == NULL)
					c = inet_ntop(at2->family, at2->addr, buffer, sizeof(buffer));
				else
					c = h->h_name;

				if (c == NULL)
					return GAIH_OKIFUNSPEC | -EAI_NONAME;

				namelen = strlen(c) + 1;
			} else
				namelen = 0;

#if __HAS_IPV6__
			if (at2->family == AF_INET6 || v4mapped) {
				family = AF_INET6;
				socklen = sizeof(struct sockaddr_in6);
			} else
#endif
			{
				family = AF_INET;
				socklen = sizeof(struct sockaddr_in);
			}

			for (st2 = st; st2 != NULL; st2 = st2->next) {
				*pai = owmalloc(sizeof(struct addrinfo) + socklen + namelen);
				if (*pai == NULL)
					return -EAI_MEMORY;

				(*pai)->ai_flags = req->ai_flags;
				(*pai)->ai_family = family;
				(*pai)->ai_socktype = st2->socktype;
				(*pai)->ai_protocol = st2->protocol;
				(*pai)->ai_addrlen = socklen;
				(*pai)->ai_addr = (void *) (*pai) + sizeof(struct addrinfo);
#ifdef HAVE_SA_LEN
				(*pai)->ai_addr->sa_len = socklen;
#endif							/* HAVE_SA_LEN */
				(*pai)->ai_addr->sa_family = family;

#if __HAS_IPV6__
				if (family == AF_INET6) {
					struct sockaddr_in6 *sin6p = (struct sockaddr_in6 *) (*pai)->ai_addr;

					sin6p->sin6_flowinfo = 0;
					if (at2->family == AF_INET6) {
						memcpy(&sin6p->sin6_addr, at2->addr, sizeof(struct in6_addr));
					} else {
						sin6p->sin6_addr.s6_addr32[0] = 0;
						sin6p->sin6_addr.s6_addr32[1] = 0;
						sin6p->sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
						memcpy(&sin6p->sin6_addr.s6_addr32[3], at2->addr, sizeof(sin6p->sin6_addr.s6_addr32[3]));
					}
					sin6p->sin6_port = st2->port;
					sin6p->sin6_scope_id = at2->scopeid;
				} else
#endif
				{
					struct sockaddr_in *sinp = (struct sockaddr_in *) (*pai)->ai_addr;

					memcpy(&sinp->sin_addr, at2->addr, sizeof(struct in_addr));
					sinp->sin_port = st2->port;
					memset(sinp->sin_zero, '\0', sizeof(sinp->sin_zero));
				}

				if (c) {
					(*pai)->ai_canonname = ((void *) (*pai) + sizeof(struct addrinfo) + socklen);
					strcpy((*pai)->ai_canonname, c);
				} else
					(*pai)->ai_canonname = NULL;

				(*pai)->ai_next = NULL;
				pai = &((*pai)->ai_next);
			}

			at2 = at2->next;
		}
	}
	return 0;
}

static struct gaih gaih[] = {
#if __HAS_IPV6__
	{PF_INET6, gaih_inet},
#endif
	{PF_INET, gaih_inet},
#if 0
	{PF_LOCAL, gaih_local},
#endif
	{PF_UNSPEC, NULL}
};

int getaddrinfo(const char *name, const char *service, const struct addrinfo *hints, struct addrinfo **pai)
{
	int i = 0, j = 0, last_i = 0;
	struct addrinfo *p = NULL, **end;
	struct gaih *g = gaih, *pg = NULL;
	struct gaih_service gaih_service, *pservice;

	if (name != NULL && name[0] == '*' && name[1] == 0)
		name = NULL;

	if (service != NULL && service[0] == '*' && service[1] == 0)
		service = NULL;

	if (name == NULL && service == NULL)
		return EAI_NONAME;

	if (hints == NULL)
		hints = &default_hints;

	if (hints->ai_flags & ~(AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST | AI_ADDRCONFIG | AI_V4MAPPED | AI_ALL))
		return EAI_BADFLAGS;

	if ((hints->ai_flags & AI_CANONNAME) && name == NULL)
		return EAI_BADFLAGS;

	if (service && service[0]) {
		char *c;
		gaih_service.name = service;
		gaih_service.num = strtoul(gaih_service.name, &c, 10);
		if (*c)
			gaih_service.num = -1;
		else
			/*
			 * Can't specify a numerical socket unless a protocol
			 * family was given.
			 */
		if (hints->ai_socktype == 0 && hints->ai_protocol == 0)
			return EAI_SERVICE;
		pservice = &gaih_service;
	} else
		pservice = NULL;

	if (pai)
		end = &p;
	else
		end = NULL;

	while (g->gaih) {
		if (hints->ai_family == g->family || hints->ai_family == AF_UNSPEC) {
			if ((hints->ai_flags & AI_ADDRCONFIG)
				&& !addrconfig(g->family))
				continue;
			j++;
			if (pg == NULL || pg->gaih != g->gaih) {
				pg = g;
				i = g->gaih(name, pservice, hints, end);
				if (i != 0) {
					last_i = i;

					if (hints->ai_family == AF_UNSPEC && (i & GAIH_OKIFUNSPEC))
						continue;

					if (p)
						freeaddrinfo(p);

					return -(i & GAIH_EAI);
				}
				if (end)
					while (*end)
						end = &((*end)->ai_next);
			}
		}
		++g;
	}

	if (j == 0)
		return EAI_FAMILY;

	if (p) {
		*pai = p;
		return 0;
	}

	if (pai == NULL && last_i == 0)
		return 0;

	if (p)
		freeaddrinfo(p);

	return last_i ? -(last_i & GAIH_EAI) : EAI_NONAME;
}

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

	while (ai != NULL) {
		p = ai;
		ai = ai->ai_next;
		owfree(p);
	}
}

#define N_(x) x
static struct {
	int code;
	const char *msg;
} values[] = {
	{
	EAI_ADDRFAMILY, N_("Address family for hostname not supported")}, {
	EAI_AGAIN, N_("Temporary failure in name resolution")}, {
	EAI_BADFLAGS, N_("Bad value for ai_flags")}, {
	EAI_FAIL, N_("Non-recoverable failure in name resolution")}, {
	EAI_FAMILY, N_("ai_family not supported")}, {
	EAI_MEMORY, N_("Memory allocation failure")}, {
	EAI_NODATA, N_("No address associated with hostname")}, {
	EAI_NONAME, N_("Name or service not known")}, {
	EAI_SERVICE, N_("Servname not supported for ai_socktype")}, {
	EAI_SOCKTYPE, N_("ai_socktype not supported")}, {
	EAI_SYSTEM, N_("System error")}, {
	EAI_INPROGRESS, N_("Processing request in progress")}, {
	EAI_CANCELED, N_("Request canceled")}, {
	EAI_NOTCANCELED, N_("Request not canceled")}, {
	EAI_ALLDONE, N_("All requests done")}, {
	EAI_INTR, N_("Interrupted by a signal")}
};

const char *gai_strerror(int code)
{
	size_t i;
	for (i = 0; i < sizeof(values) / sizeof(values[0]); ++i)
		if (values[i].code == code)
			return (values[i].msg);

	return ("Unknown error");
}

#endif							/* HAVE_GETADDRINFO */



#ifndef HAVE_INET_NTOP
/* char *
 * inet_ntop4(src, dst, size)
 *      format an IPv4 address
 * return:
 *      `dst' (as a const)
 * notes:
 *      (1) uses no statics
 *      (2) takes a u_char* not an in_addr as input
 * author:
 *      Paul Vixie, 1996.
 */
static const char *inet_ntop4(const unsigned char *src, char *dst, size_t size)
{
	char tmp[sizeof("255.255.255.255") + 1] = "\0";
	int octet;
	int i;

	i = 0;
	for (octet = 0; octet <= 3; octet++) {

		if (src[octet] > 255) {
			__set_errno(ENOSPC);
			return (NULL);
		}
		tmp[i++] = '0' + src[octet] / 100;
		if (tmp[i - 1] == '0') {
			tmp[i - 1] = '0' + (src[octet] / 10 % 10);
			if (tmp[i - 1] == '0')
				i--;
		} else {
			tmp[i++] = '0' + (src[octet] / 10 % 10);
		}
		tmp[i++] = '0' + src[octet] % 10;
		tmp[i++] = '.';
	}
	tmp[i - 1] = '\0';

	if (strlen(tmp) > size) {
		__set_errno(ENOSPC);
		return (NULL);
	}

	return strcpy(dst, tmp);
}

/* char *
 * inet_ntop(af, src, dst, size)
 *      convert a network format address to presentation format.
 * return:
 *      pointer to presentation format address (`dst'), or NULL (see errno).
 * author:
 *      Paul Vixie, 1996.
 */
const char *inet_ntop(af, src, dst, size)
int af;
const void *src;
char *dst;
socklen_t size;
{
	switch (af) {
	case AF_INET:
		return (inet_ntop4(src, dst, size));
#if __HAS_IPV6__
	case AF_INET6:
		return (inet_ntop6(src, dst, size));
#endif
	default:
		__set_errno(EAFNOSUPPORT);
		return (NULL);
	}
	/* NOTREACHED */
}
#endif							/* HAVE_INET_NTOP */


#ifndef HAVE_INET_PTON
/* int
 * inet_pton4(src, dst)
 *      like inet_aton() but without all the hexadecimal and shorthand.
 * return:
 *      1 if `src' is a valid dotted quad, else 0.
 * notice:
 *      does not touch `dst' unless it's returning 1.
 * author:
 *      Paul Vixie, 1996.
 */
static int inet_pton4(const char *src, unsigned char *dst)
{
	int saw_digit, octets, ch;
	unsigned char tmp[4], *tp;

	saw_digit = 0;
	octets = 0;
	*(tp = tmp) = 0;
	while ((ch = *src++) != '\0') {

		if (ch >= '0' && ch <= '9') {
			unsigned int new = *tp * 10 + (ch - '0');

			if (new > 255)
				return (0);
			*tp = new;
			if (!saw_digit) {
				if (++octets > 4)
					return (0);
				saw_digit = 1;
			}
		} else if (ch == '.' && saw_digit) {
			if (octets == 4)
				return (0);
			*++tp = 0;
			saw_digit = 0;
		} else
			return (0);
	}
	if (octets < 4)
		return (0);
	memcpy(dst, tmp, 4);
	return (1);
}

/* int
 * inet_pton(af, src, dst)
 *      convert from presentation format (which usually means ASCII printable)
 *      to network format (which is usually some kind of binary format).
 * return:
 *      1 if the address was valid for the specified address family
 *      0 if the address wasn't valid (`dst' is untouched in this case)
 *      -1 if some other error occurred (`dst' is untouched in this case, too)
 * author:
 *      Paul Vixie, 1996.
 */
int inet_pton(af, src, dst)
int af;
const char *src;
void *dst;
{
	switch (af) {
	case AF_INET:
		return (inet_pton4(src, dst));
#if __HAS_IPV6__
	case AF_INET6:
		return (inet_pton6(src, dst));
#endif
	default:
		__set_errno(EAFNOSUPPORT);
		return (-1);
	}
	/* NOTREACHED */
}
#endif							/* HAVE_INET_PTON */
