getaddrinfo.c: New file

3 files changed, 2859 insertions, 2 deletions

diff --git a/freebsd-userspace/Makefile b/freebsd-userspace/Makefile
index fb84e881..f7f162c3 100644
--- a/freebsd-userspace/Makefile
+++ b/freebsd-userspace/Makefile
@@ -9,6 +9,8 @@ CFLAGS += -I rtems/include
 CFLAGS += -I lib/libc/include 
 CFLAGS += -I sys
 CFLAGS += -I local 
+# XXX hack to find rpc
+CFLAGS += -I ../services/librpc/include 
 
 CFLAGS += -I $(INSTALL_BASE)/include
 
@@ -34,6 +36,7 @@ C_FILES += lib/libc/inet/nsap_addr.c
 
 C_FILES += lib/libc/net/base64.c
 C_FILES += lib/libc/net/ether_addr.c
+C_FILES += lib/libc/net/getaddrinfo.c
 C_FILES += lib/libc/net/gethostbydns.c
 C_FILES += lib/libc/net/gethostbyht.c
 C_FILES += lib/libc/net/gethostbynis.c
diff --git a/freebsd-userspace/from-freebsd.sh b/freebsd-userspace/from-freebsd.sh
index 13236023..dc43fb69 100755
--- a/freebsd-userspace/from-freebsd.sh
+++ b/freebsd-userspace/from-freebsd.sh
@@ -102,7 +102,6 @@ done <<EOF
 include/db.h
 include/ifaddrs.h
 include/netconfig.h
-include/netdb.h
 include/nsswitch.h
 include/resolv.h
 include/res_update.h
@@ -114,7 +113,6 @@ include/rpc/clnt_soc.h
 include/rpc/clnt_stat.h
 include/rpc/pmap_clnt.h
 include/rpc/pmap_prot.h
-include/rpc/rpc.h
 include/rpc/rpcent.h
 include/rpc/rpc_msg.h
 include/rpc/rpcb_clnt.h
@@ -181,6 +179,7 @@ do
 done <<EOF
 lib/libc/net/base64.c
 lib/libc/net/ether_addr.c
+lib/libc/net/getaddrinfo.c
 lib/libc/net/gethostbydns.c
 lib/libc/net/gethostbyht.c
 lib/libc/net/gethostbynis.c
@@ -264,3 +263,8 @@ EOF
 echo "#include <sys/syslog.h>" > local/syslog.h
 # Should be able to copy this except for printflike issue
 # sys/sys/syslog.h
+
+# netdb.h has an issue with __socklen_t which needs to be run down
+# for now, a manually edited copy is in rtems/include
+# include/rpc/rpc.h has issue with internal methods changing from 
+#   old implementation to current day. We need to update our RPC
diff --git a/freebsd-userspace/lib/libc/net/getaddrinfo.c b/freebsd-userspace/lib/libc/net/getaddrinfo.c
new file mode 100644
index 00000000..bbd5efab
--- /dev/null
+++ b/freebsd-userspace/lib/libc/net/getaddrinfo.c
@@ -0,0 +1,2850 @@
+#include "port_before.h"
+
+/*	$KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun 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.
+ */
+
+/*
+ * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
+ *
+ * Issues to be discussed:
+ * - 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.
+ * - freeaddrinfo(NULL).  RFC2553 is silent about it.  XNET 5.2 says it is
+ *   invalid.  current code - SEGV on freeaddrinfo(NULL)
+ *
+ * Note:
+ * - 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?
+ * - (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?
+ *
+ * OS specific notes for freebsd4:
+ * - FreeBSD supported $GAI.  The code does not.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <sys/queue.h>
+#ifdef INET6
+#include <net/if_var.h>
+#include <sys/sysctl.h>
+#include <sys/ioctl.h>
+#include <netinet6/in6_var.h>	/* XXX */
+#endif
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <rpc/rpc.h>
+#include <rpcsvc/yp_prot.h>
+#include <rpcsvc/ypclnt.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 "res_config.h"
+
+#ifdef DEBUG
+#include <syslog.h>
+#endif
+
+#include <stdarg.h>
+#include <nsswitch.h>
+#include "un-namespace.h"
+#include "libc_private.h"
+#ifdef NS_CACHING
+#include "nscache.h"
+#endif
+
+#if defined(__KAME__) && defined(INET6)
+# define FAITH
+#endif
+
+#define ANY 0
+#define YES 1
+#define NO  0
+
+static const char in_addrany[] = { 0, 0, 0, 0 };
+static const char in_loopback[] = { 127, 0, 0, 1 };
+#ifdef INET6
+static const char in6_addrany[] = {
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+static const char in6_loopback[] = {
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
+};
+#endif
+
+struct policyqueue {
+	TAILQ_ENTRY(policyqueue) pc_entry;
+#ifdef INET6
+	struct in6_addrpolicy pc_policy;
+#endif
+};
+TAILQ_HEAD(policyhead, policyqueue);
+
+static const struct afd {
+	int a_af;
+	int a_addrlen;
+	socklen_t a_socklen;
+	int a_off;
+	const char *a_addrany;
+	const char *a_loopback;
+	int a_scoped;
+} afdl [] = {
+#ifdef INET6
+#define	N_INET6 0
+	{PF_INET6, sizeof(struct in6_addr),
+	 sizeof(struct sockaddr_in6),
+	 offsetof(struct sockaddr_in6, sin6_addr),
+	 in6_addrany, in6_loopback, 1},
+#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, 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, ANY, ANY, NULL, 0x01 },
+#endif
+#ifdef INET6
+	{ PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
+	{ PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
+	{ PF_INET6, SOCK_STREAM, IPPROTO_SCTP, "sctp", 0x03 },
+	{ PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 0x07 },
+	{ PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
+#endif
+	{ PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
+	{ PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
+	{ PF_INET, SOCK_STREAM, IPPROTO_SCTP, "sctp", 0x03 },
+	{ PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 0x07 },
+	{ PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
+	{ -1, 0, 0, NULL, 0 },
+};
+
+#ifdef INET6
+#define PTON_MAX	16
+#else
+#define PTON_MAX	4
+#endif
+
+#define AIO_SRCFLAG_DEPRECATED	0x1
+
+struct ai_order {
+	union {
+		struct sockaddr_storage aiou_ss;
+		struct sockaddr aiou_sa;
+	} aio_src_un;
+#define aio_srcsa aio_src_un.aiou_sa
+	u_int32_t aio_srcflag;
+	int aio_srcscope;
+	int aio_dstscope;
+	struct policyqueue *aio_srcpolicy;
+	struct policyqueue *aio_dstpolicy;
+	struct addrinfo *aio_ai;
+	int aio_matchlen;
+};
+
+static const ns_src default_dns_files[] = {
+	{ NSSRC_FILES, 	NS_SUCCESS },
+	{ NSSRC_DNS, 	NS_SUCCESS },
+	{ 0 }
+};
+
+struct res_target {
+	struct res_target *next;
+	const char *name;	/* domain name */
+	int qclass, qtype;	/* class and type of query */
+	u_char *answer;		/* buffer to put answer */
+	int anslen;		/* size of answer buffer */
+	int n;			/* result length */
+};
+
+#define MAXPACKET	(64*1024)
+
+typedef union {
+	HEADER hdr;
+	u_char buf[MAXPACKET];
+} querybuf;
+
+static int str2number(const char *, int *);
+static int explore_copy(const struct addrinfo *, const struct addrinfo *,
+	struct addrinfo **);
+static int explore_null(const struct addrinfo *,
+	const char *, struct addrinfo **);
+static int explore_numeric(const struct addrinfo *, const char *,
+	const char *, struct addrinfo **, const char *);
+static int explore_numeric_scope(const struct addrinfo *, const char *,
+	const char *, struct addrinfo **);
+static int get_canonname(const struct addrinfo *,
+	struct addrinfo *, const char *);
+static struct addrinfo *get_ai(const struct addrinfo *,
+	const struct afd *, const char *);
+static struct addrinfo *copy_ai(const struct addrinfo *);
+static int get_portmatch(const struct addrinfo *, const char *);
+static int get_port(struct addrinfo *, const char *, int);
+static const struct afd *find_afd(int);
+static int addrconfig(struct addrinfo *);
+static void set_source(struct ai_order *, struct policyhead *);
+static int comp_dst(const void *, const void *);
+#ifdef INET6
+static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
+#endif
+static int gai_addr2scopetype(struct sockaddr *);
+
+static int explore_fqdn(const struct addrinfo *, const char *,
+	const char *, struct addrinfo **);
+
+static int reorder(struct addrinfo *);
+static int get_addrselectpolicy(struct policyhead *);
+static void free_addrselectpolicy(struct policyhead *);
+static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
+	struct policyhead *);
+static int matchlen(struct sockaddr *, struct sockaddr *);
+
+static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
+	const struct addrinfo *, res_state);
+#if defined(RESOLVSORT)
+static int addr4sort(struct addrinfo *, res_state);
+#endif
+static int _dns_getaddrinfo(void *, void *, va_list);
+static void _sethtent(FILE **);
+static void _endhtent(FILE **);
+static struct addrinfo *_gethtent(FILE **, const char *,
+	const struct addrinfo *);
+static int _files_getaddrinfo(void *, void *, va_list);
+#ifdef YP
+static struct addrinfo *_yphostent(char *, const struct addrinfo *);
+static int _yp_getaddrinfo(void *, void *, va_list);
+#endif
+#ifdef NS_CACHING
+static int addrinfo_id_func(char *, size_t *, va_list, void *);
+static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *);
+static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *);
+#endif
+
+static int res_queryN(const char *, struct res_target *, res_state);
+static int res_searchN(const char *, struct res_target *, res_state);
+static int res_querydomainN(const char *, const char *,
+	struct res_target *, res_state);
+
+/* 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)
+
+#define ERR(err) \
+do { \
+	/* external reference: error, and label bad */ \
+	error = (err); \
+	goto bad; \
+	/*NOTREACHED*/ \
+} while (/*CONSTCOND*/0)
+
+#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)))
+
+void
+freeaddrinfo(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
+str2number(const char *p, int *portp)
+{
+	char *ep;
+	unsigned long v;
+
+	if (*p == '\0')
+		return -1;
+	ep = NULL;
+	errno = 0;
+	v = strtoul(p, &ep, 10);
+	if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) {
+		*portp = v;
+		return 0;
+	} else
+		return -1;
+}
+
+int
+getaddrinfo(const char *hostname, const char *servname,
+    const struct addrinfo *hints, struct addrinfo **res)
+{
+	struct addrinfo sentinel;
+	struct addrinfo *cur;
+	int error = 0;
+	struct addrinfo ai, ai0, *afai;
+	struct addrinfo *pai;
+	const struct afd *afd;
+	const struct explore *ex;
+	struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])];
+	struct addrinfo *afai_unspec;
+	int found;
+	int numeric = 0;
+
+	/* ensure we return NULL on errors */
+	*res = NULL;
+
+	memset(&ai, 0, sizeof(ai));
+
+	memset(afailist, 0, sizeof(afailist));
+	afai_unspec = NULL;
+
+	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;
+	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)
+			ERR(EAI_BADHINTS); /* xxx */
+		if (hints->ai_flags & ~AI_MASK)
+			ERR(EAI_BADFLAGS);
+		switch (hints->ai_family) {
+		case PF_UNSPEC:
+		case PF_INET:
+#ifdef INET6
+		case PF_INET6:
+#endif
+			break;
+		default:
+			ERR(EAI_FAMILY);
+		}
+		memcpy(pai, hints, sizeof(*pai));
+
+		/*
+		 * 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 (!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;
+
+				/* matched */
+				break;
+			}
+
+			if (ex->e_af < 0)
+				ERR(EAI_BADHINTS);
+		}
+	}
+
+	/*
+	 * 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)
+			ERR(error);
+
+		*pai = ai0;
+	}
+
+	ai0 = *pai;
+
+	/*
+	 * NULL hostname, or numeric hostname.
+	 * If numeric representation of AF1 can be interpreted as FQDN
+	 * representation of AF2, we need to think again about the code below.
+	 */
+	found = 0;
+	for (afd = afdl; afd->a_af; afd++) {
+		*pai = ai0;
+
+		if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1))
+			continue;
+
+		if (pai->ai_family == PF_UNSPEC)
+			pai->ai_family = afd->a_af;
+
+		if (hostname == NULL) {
+			error = explore_null(pai, servname,
+			    &afailist[afd - afdl]);
+
+			/*
+			 * Errors from explore_null should be unexpected and
+			 * be caught to avoid returning an incomplete result.
+			 */
+			if (error != 0)
+				goto bad;
+		} else {
+			error = explore_numeric_scope(pai, hostname, servname,
+			    &afailist[afd - afdl]);
+
+			/*
+			 * explore_numeric_scope returns an error for address
+			 * families that do not match that of hostname.
+			 * Thus we should not catch the error at this moment. 
+			 */
+		}
+
+		if (!error && afailist[afd - afdl])
+			found++;
+	}
+	if (found) {
+		numeric = 1;
+		goto globcopy;
+	}
+
+	if (hostname == NULL)
+		ERR(EAI_NONAME);	/* used to be EAI_NODATA */
+	if (pai->ai_flags & AI_NUMERICHOST)
+		ERR(EAI_NONAME);
+
+	if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
+		ERR(EAI_FAIL);
+
+	/*
+	 * hostname as alphabetical name.
+	 */
+	*pai = ai0;
+	error = explore_fqdn(pai, hostname, servname, &afai_unspec);
+
+globcopy:
+	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 (afai_unspec)
+			afai = afai_unspec;
+		else {
+			if ((afd = find_afd(pai->ai_family)) == NULL)
+				continue;
+			/* XXX assumes that afd points inside afdl[] */
+			afai = afailist[afd - afdl];
+		}
+		if (!afai)
+			continue;
+
+		error = explore_copy(pai, afai, &cur->ai_next);
+		if (error != 0)
+			goto bad;
+
+		while (cur && cur->ai_next)
+			cur = cur->ai_next;
+	}
+
+	/*
+	 * ensure we return either:
+	 * - error == 0, non-NULL *res
+	 * - error != 0, NULL *res
+	 */
+	if (error == 0) {
+		if (sentinel.ai_next) {
+			/*
+			 * If the returned entry is for an active connection,
+			 * and the given name is not numeric, reorder the
+			 * list, so that the application would try the list
+			 * in the most efficient order.  Since the head entry
+			 * of the original list may contain ai_canonname and
+			 * that entry may be moved elsewhere in the new list,
+			 * we keep the pointer and will  restore it in the new
+			 * head entry.  (Note that RFC3493 requires the head
+			 * entry store it when requested by the caller).
+			 */
+			if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) {
+				if (!numeric) {
+					char *canonname;
+
+					canonname =
+					    sentinel.ai_next->ai_canonname;
+					sentinel.ai_next->ai_canonname = NULL;
+					(void)reorder(&sentinel);
+					if (sentinel.ai_next->ai_canonname ==
+					    NULL) {
+						sentinel.ai_next->ai_canonname
+						    = canonname;
+					} else if (canonname != NULL)
+						free(canonname);
+				}
+			}
+			*res = sentinel.ai_next;
+		} else
+			error = EAI_FAIL;
+	}
+
+bad:
+	if (afai_unspec)
+		freeaddrinfo(afai_unspec);
+	for (afd = afdl; afd->a_af; afd++) {
+		if (afailist[afd - afdl])
+			freeaddrinfo(afailist[afd - afdl]);
+	}
+	if (!*res)
+		if (sentinel.ai_next)
+			freeaddrinfo(sentinel.ai_next);
+
+	return (error);
+}
+
+static int
+reorder(struct addrinfo *sentinel)
+{
+	struct addrinfo *ai, **aip;
+	struct ai_order *aio;
+	int i, n;
+	struct policyhead policyhead;
+
+	/* count the number of addrinfo elements for sorting. */
+	for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++)
+		;
+
+	/*
+	 * If the number is small enough, we can skip the reordering process.
+	 */
+	if (n <= 1)
+		return(n);
+
+	/* allocate a temporary array for sort and initialization of it. */
+	if ((aio = malloc(sizeof(*aio) * n)) == NULL)
+		return(n);	/* give up reordering */
+	memset(aio, 0, sizeof(*aio) * n);
+
+	/* retrieve address selection policy from the kernel */
+	TAILQ_INIT(&policyhead);
+	if (!get_addrselectpolicy(&policyhead)) {
+		/* no policy is installed into kernel, we don't sort. */
+		free(aio);
+		return (n);
+	}
+
+	for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) {
+		aio[i].aio_ai = ai;
+		aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr);
+		aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr,
+							      &policyhead);
+		set_source(&aio[i], &policyhead);
+	}
+
+	/* perform sorting. */
+	qsort(aio, n, sizeof(*aio), comp_dst);
+
+	/* reorder the addrinfo chain. */
+	for (i = 0, aip = &sentinel->ai_next; i < n; i++) {
+		*aip = aio[i].aio_ai;
+		aip = &aio[i].aio_ai->ai_next;
+	}
+	*aip = NULL;
+
+	/* cleanup and return */
+	free(aio);
+	free_addrselectpolicy(&policyhead);
+	return(n);
+}
+
+static int
+get_addrselectpolicy(struct policyhead *head)
+{
+#ifdef INET6
+	int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
+	size_t l;
+	char *buf;
+	struct in6_addrpolicy *pol, *ep;
+
+	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0)
+		return (0);
+	if ((buf = malloc(l)) == NULL)
+		return (0);
+	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) {
+		free(buf);
+		return (0);
+	}
+
+	ep = (struct in6_addrpolicy *)(buf + l);
+	for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) {
+		struct policyqueue *new;
+
+		if ((new = malloc(sizeof(*new))) == NULL) {
+			free_addrselectpolicy(head); /* make the list empty */
+			break;
+		}
+		new->pc_policy = *pol;
+		TAILQ_INSERT_TAIL(head, new, pc_entry);
+	}
+
+	free(buf);
+	return (1);
+#else
+	return (0);
+#endif
+}
+
+static void
+free_addrselectpolicy(struct policyhead *head)
+{
+	struct policyqueue *ent, *nent;
+
+	for (ent = TAILQ_FIRST(head); ent; ent = nent) {
+		nent = TAILQ_NEXT(ent, pc_entry);
+		TAILQ_REMOVE(head, ent, pc_entry);
+		free(ent);
+	}
+}
+
+static struct policyqueue *
+match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
+{
+#ifdef INET6
+	struct policyqueue *ent, *bestent = NULL;
+	struct in6_addrpolicy *pol;
+	int matchlen, bestmatchlen = -1;
+	u_char *mp, *ep, *k, *p, m;
+	struct sockaddr_in6 key;
+
+	switch(addr->sa_family) {
+	case AF_INET6:
+		key = *(struct sockaddr_in6 *)addr;
+		break;
+	case AF_INET:
+		/* convert the address into IPv4-mapped IPv6 address. */
+		memset(&key, 0, sizeof(key));
+		key.sin6_family = AF_INET6;
+		key.sin6_len = sizeof(key);
+		key.sin6_addr.s6_addr[10] = 0xff;
+		key.sin6_addr.s6_addr[11] = 0xff;
+		memcpy(&key.sin6_addr.s6_addr[12],
+		       &((struct sockaddr_in *)addr)->sin_addr, 4);
+		break;
+	default:
+		return(NULL);
+	}
+
+	for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
+		pol = &ent->pc_policy;
+		matchlen = 0;
+
+		mp = (u_char *)&pol->addrmask.sin6_addr;
+		ep = mp + 16;	/* XXX: scope field? */
+		k = (u_char *)&key.sin6_addr;
+		p = (u_char *)&pol->addr.sin6_addr;
+		for (; mp < ep && *mp; mp++, k++, p++) {
+			m = *mp;
+			if ((*k & m) != *p)
+				goto next; /* not match */
+			if (m == 0xff) /* short cut for a typical case */
+				matchlen += 8;
+			else {
+				while (m >= 0x80) {
+					matchlen++;
+					m <<= 1;
+				}
+			}
+		}
+
+		/* matched.  check if this is better than the current best. */
+		if (matchlen > bestmatchlen) {
+			bestent = ent;
+			bestmatchlen = matchlen;
+		}
+
+	  next:
+		continue;
+	}
+
+	return(bestent);
+#else
+	return(NULL);
+#endif
+
+}
+
+static void
+set_source(struct ai_order *aio, struct policyhead *ph)
+{
+	struct addrinfo ai = *aio->aio_ai;
+	struct sockaddr_storage ss;
+	socklen_t srclen;
+	int s;
+
+	/* set unspec ("no source is available"), just in case */
+	aio->aio_srcsa.sa_family = AF_UNSPEC;
+	aio->aio_srcscope = -1;
+
+	switch(ai.ai_family) {
+	case AF_INET:
+#ifdef INET6
+	case AF_INET6:
+#endif
+		break;
+	default:		/* ignore unsupported AFs explicitly */
+		return;
+	}
+
+	/* XXX: make a dummy addrinfo to call connect() */
+	ai.ai_socktype = SOCK_DGRAM;
+	ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */
+	ai.ai_next = NULL;
+	memset(&ss, 0, sizeof(ss));
+	memcpy(&ss, ai.ai_addr, ai.ai_addrlen);
+	ai.ai_addr = (struct sockaddr *)&ss;
+	get_port(&ai, "1", 0);
+
+	/* open a socket to get the source address for the given dst */
+	if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0)
+		return;		/* give up */
+	if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0)
+		goto cleanup;
+	srclen = ai.ai_addrlen;
+	if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
+		aio->aio_srcsa.sa_family = AF_UNSPEC;
+		goto cleanup;
+	}
+	aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
+	aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
+	aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr);
+#ifdef INET6
+	if (ai.ai_family == AF_INET6) {
+		struct in6_ifreq ifr6;
+		u_int32_t flags6;
+
+		/* XXX: interface name should not be hardcoded */
+		strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name));
+		memset(&ifr6, 0, sizeof(ifr6));
+		memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen);
+		if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
+			flags6 = ifr6.ifr_ifru.ifru_flags6;
+			if ((flags6 & IN6_IFF_DEPRECATED))
+				aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
+		}
+	}
+#endif
+
+  cleanup:
+	_close(s);
+	return;
+}
+
+static int
+matchlen(struct sockaddr *src, struct sockaddr *dst)
+{
+	int match = 0;
+	u_char *s, *d;
+	u_char *lim, r;
+	int addrlen;
+
+	switch (src->sa_family) {
+#ifdef INET6
+	case AF_INET6:
+		s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr;
+		d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr;
+		addrlen = sizeof(struct in6_addr);
+		lim = s + addrlen;
+		break;
+#endif
+	case AF_INET:
+		s = (u_char *)&((struct sockaddr_in *)src)->sin_addr;
+		d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr;
+		addrlen = sizeof(struct in_addr);
+		lim = s + addrlen;
+		break;
+	default:
+		return(0);
+	}
+
+	while (s < lim)
+		if ((r = (*d++ ^ *s++)) != 0) {
+			while (r < addrlen * 8) {
+				match++;
+				r <<= 1;
+			}
+			break;
+		} else
+			match += 8;
+	return(match);
+}
+
+static int
+comp_dst(const void *arg1, const void *arg2)
+{
+	const struct ai_order *dst1 = arg1, *dst2 = arg2;
+
+	/*
+	 * Rule 1: Avoid unusable destinations.
+	 * XXX: we currently do not consider if an appropriate route exists.
+	 */
+	if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
+	    dst2->aio_srcsa.sa_family == AF_UNSPEC) {
+		return(-1);
+	}
+	if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
+	    dst2->aio_srcsa.sa_family != AF_UNSPEC) {
+		return(1);
+	}
+
+	/* Rule 2: Prefer matching scope. */
+	if (dst1->aio_dstscope == dst1->aio_srcscope &&
+	    dst2->aio_dstscope != dst2->aio_srcscope) {
+		return(-1);
+	}
+	if (dst1->aio_dstscope != dst1->aio_srcscope &&
+	    dst2->aio_dstscope == dst2->aio_srcscope) {
+		return(1);
+	}
+
+	/* Rule 3: Avoid deprecated addresses. */
+	if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
+	    dst2->aio_srcsa.sa_family != AF_UNSPEC) {
+		if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
+		    (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
+			return(-1);
+		}
+		if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
+		    !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
+			return(1);
+		}
+	}
+
+	/* Rule 4: Prefer home addresses. */
+	/* XXX: not implemented yet */
+
+	/* Rule 5: Prefer matching label. */
+#ifdef INET6
+	if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
+	    dst1->aio_srcpolicy->pc_policy.label ==
+	    dst1->aio_dstpolicy->pc_policy.label &&
+	    (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
+	     dst2->aio_srcpolicy->pc_policy.label !=
+	     dst2->aio_dstpolicy->pc_policy.label)) {
+		return(-1);
+	}
+	if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
+	    dst2->aio_srcpolicy->pc_policy.label ==
+	    dst2->aio_dstpolicy->pc_policy.label &&
+	    (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
+	     dst1->aio_srcpolicy->pc_policy.label !=
+	     dst1->aio_dstpolicy->pc_policy.label)) {
+		return(1);
+	}
+#endif
+
+	/* Rule 6: Prefer higher precedence. */
+#ifdef INET6
+	if (dst1->aio_dstpolicy &&
+	    (dst2->aio_dstpolicy == NULL ||
+	     dst1->aio_dstpolicy->pc_policy.preced >
+	     dst2->aio_dstpolicy->pc_policy.preced)) {
+		return(-1);
+	}
+	if (dst2->aio_dstpolicy &&
+	    (dst1->aio_dstpolicy == NULL ||
+	     dst2->aio_dstpolicy->pc_policy.preced >
+	     dst1->aio_dstpolicy->pc_policy.preced)) {
+		return(1);
+	}
+#endif
+
+	/* Rule 7: Prefer native transport. */
+	/* XXX: not implemented yet */
+
+	/* Rule 8: Prefer smaller scope. */
+	if (dst1->aio_dstscope >= 0 &&
+	    dst1->aio_dstscope < dst2->aio_dstscope) {
+		return(-1);
+	}
+	if (dst2->aio_dstscope >= 0 &&
+	    dst2->aio_dstscope < dst1->aio_dstscope) {
+		return(1);
+	}
+
+	/*
+	 * Rule 9: Use longest matching prefix.
+	 * We compare the match length in a same AF only.
+	 */
+	if (dst1->aio_ai->ai_addr->sa_family ==
+	    dst2->aio_ai->ai_addr->sa_family) {
+		if (dst1->aio_matchlen > dst2->aio_matchlen) {
+			return(-1);
+		}
+		if (dst1->aio_matchlen < dst2->aio_matchlen) {
+			return(1);
+		}
+	}
+
+	/* Rule 10: Otherwise, leave the order unchanged. */
+	return(-1);
+}
+
+/*
+ * Copy from scope.c.
+ * XXX: we should standardize the functions and link them as standard
+ * library.
+ */
+static int
+gai_addr2scopetype(struct sockaddr *sa)
+{
+#ifdef INET6
+	struct sockaddr_in6 *sa6;
+#endif
+	struct sockaddr_in *sa4;
+
+	switch(sa->sa_family) {
+#ifdef INET6
+	case AF_INET6:
+		sa6 = (struct sockaddr_in6 *)sa;
+		if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
+			/* just use the scope field of the multicast address */
+			return(sa6->sin6_addr.s6_addr[2] & 0x0f);
+		}
+		/*
+		 * Unicast addresses: map scope type to corresponding scope
+		 * value defined for multcast addresses.
+		 * XXX: hardcoded scope type values are bad...
+		 */
+		if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
+			return(1); /* node local scope */
+		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
+			return(2); /* link-local scope */
+		if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
+			return(5); /* site-local scope */
+		return(14);	/* global scope */
+		break;
+#endif
+	case AF_INET:
+		/*
+		 * IPv4 pseudo scoping according to RFC 3484.
+		 */
+		sa4 = (struct sockaddr_in *)sa;
+		/* IPv4 autoconfiguration addresses have link-local scope. */
+		if (((u_char *)&sa4->sin_addr)[0] == 169 &&
+		    ((u_char *)&sa4->sin_addr)[1] == 254)
+			return(2);
+		/* Private addresses have site-local scope. */
+		if (((u_char *)&sa4->sin_addr)[0] == 10 ||
+		    (((u_char *)&sa4->sin_addr)[0] == 172 &&
+		     (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) ||
+		    (((u_char *)&sa4->sin_addr)[0] == 192 &&
+		     ((u_char *)&sa4->sin_addr)[1] == 168))
+			return(14);	/* XXX: It should be 5 unless NAT */
+		/* Loopback addresses have link-local scope. */
+		if (((u_char *)&sa4->sin_addr)[0] == 127)
+			return(2);
+		return(14);
+		break;
+	default:
+		errno = EAFNOSUPPORT; /* is this a good error? */
+		return(-1);
+	}
+}
+
+static int
+explore_copy(const struct addrinfo *pai, const struct addrinfo *src0,
+    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(const struct addrinfo *pai, const char *servname,
+    struct addrinfo **res)
+{
+	int s;
+	const struct afd *afd;
+	struct addrinfo *ai;
+	int error;
+
+	*res = NULL;
+	ai = NULL;
+
+	/*
+	 * filter out AFs that are not supported by the kernel
+	 * XXX errno?
+	 */
+	s = _socket(pai->ai_family, SOCK_DGRAM, 0);
+	if (s < 0) {
+		if (errno != EMFILE)
+			return 0;
+	} else
+		_close(s);
+
+	afd = find_afd(pai->ai_family);
+	if (afd == NULL)
+		return 0;
+
+	if (pai->ai_flags & AI_PASSIVE) {
+		GET_AI(ai, afd, afd->a_addrany);
+		GET_PORT(ai, servname);
+	} else {
+		GET_AI(ai, afd, afd->a_loopback);
+		GET_PORT(ai, servname);
+	}
+
+	*res = ai;
+	return 0;
+
+free:
+	if (ai != NULL)
+		freeaddrinfo(ai);
+	return error;
+}
+
+/*
+ * numeric hostname
+ */
+static int
+explore_numeric(const struct addrinfo *pai, const char *hostname,
+    const char *servname, struct addrinfo **res, const char *canonname)
+{
+	const struct afd *afd;
+	struct addrinfo *ai;
+	int error;
+	char pton[PTON_MAX];
+
+	*res = NULL;
+	ai = NULL;
+
+	afd = find_afd(pai->ai_family);
+	if (afd == NULL)
+		return 0;
+
+	switch (afd->a_af) {
+	case AF_INET:
+		/*
+		 * RFC3493 requires getaddrinfo() to accept AF_INET formats
+		 * that are accepted by inet_addr() and its family.  The
+		 * accepted forms includes the "classful" one, which inet_pton
+		 * does not accept.  So we need to separate the case for
+		 * AF_INET.
+		 */
+		if (inet_aton(hostname, (struct in_addr *)pton) != 1)
+			return 0;
+		break;
+	default:
+		if (inet_pton(afd->a_af, hostname, pton) != 1)
+			return 0;
+		break;
+	}
+
+	if (pai->ai_family == afd->a_af) {
+		GET_AI(ai, afd, pton);
+		GET_PORT(ai, servname);
+		if ((pai->ai_flags & AI_CANONNAME)) {
+			/*
+			 * Set the numeric address itself as the canonical
+			 * name, based on a clarification in RFC3493.
+			 */
+			GET_CANONNAME(ai, canonname);
+		}
+	} else {
+		/*
+		 * XXX: This should not happen since we already matched the AF
+		 * by find_afd.
+		 */
+		ERR(EAI_FAMILY);
+	}
+
+	*res = ai;
+	return 0;
+
+free:
+bad:
+	if (ai != NULL)
+		freeaddrinfo(ai);
+	return error;
+}
+
+/*
+ * numeric hostname with scope
+ */
+static int
+explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
+    const char *servname, struct addrinfo **res)
+{
+#if !defined(SCOPE_DELIMITER) || !defined(INET6)
+	return explore_numeric(pai, hostname, servname, res, hostname);
+#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, hostname);
+
+	cp = strchr(hostname, SCOPE_DELIMITER);
+	if (cp == NULL)
+		return explore_numeric(pai, hostname, servname, res, hostname);
+
+	/*
+	 * 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, hostname);
+	if (error == 0) {
+		u_int32_t scopeid;
+
+		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) == -1) {
+				free(hostname2);
+				freeaddrinfo(*res);
+				*res = NULL;
+				return(EAI_NONAME); /* XXX: is return OK? */
+			}
+			sin6->sin6_scope_id = scopeid;
+		}
+	}
+
+	free(hostname2);
+
+	if (error && *res) {
+		freeaddrinfo(*res);
+		*res = NULL;
+	}
+	return error;
+#endif
+}
+
+static int
+get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
+{
+	if ((pai->ai_flags & AI_CANONNAME) != 0) {
+		ai->ai_canonname = strdup(str);
+		if (ai->ai_canonname == NULL)
+			return EAI_MEMORY;
+	}
+	return 0;
+}
+
+static struct addrinfo *
+get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
+{
+	char *p;
+	struct addrinfo *ai;
+#ifdef FAITH
+	struct in6_addr faith_prefix;
+	char *fp_str;
+	int translate = 0;
+#endif
+
+#ifdef FAITH
+	/*
+	 * Transfrom an IPv4 addr into a special IPv6 addr format for
+	 * IPv6->IPv4 translation gateway. (only TCP is supported now)
+	 *
+	 * +-----------------------------------+------------+
+	 * | faith prefix part (12 bytes)      | embedded   |
+	 * |                                   | IPv4 addr part (4 bytes)
+	 * +-----------------------------------+------------+
+	 *
+	 * faith prefix part is specified as ascii IPv6 addr format
+	 * in environmental variable GAI.
+	 * For FAITH to work correctly, routing to faith prefix must be
+	 * setup toward a machine where a FAITH daemon operates.
+	 * Also, the machine must enable some mechanizm
+	 * (e.g. faith interface hack) to divert those packet with
+	 * faith prefixed destination addr to user-land FAITH daemon.
+	 */
+	fp_str = getenv("GAI");
+	if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
+	    afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
+		u_int32_t v4a;
+		u_int8_t v4a_top;
+
+		memcpy(&v4a, addr, sizeof v4a);
+		v4a_top = v4a >> IN_CLASSA_NSHIFT;
+		if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
+		    v4a_top != 0 && v4a != IN_LOOPBACKNET) {
+			afd = &afdl[N_INET6];
+			memcpy(&faith_prefix.s6_addr[12], addr,
+			       sizeof(struct in_addr));
+			translate = 1;
+		}
+	}
+#endif
+
+	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);
+	ai->ai_addr->sa_len = afd->a_socklen;
+	ai->ai_addrlen = afd->a_socklen;
+	ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
+	p = (char *)(void *)(ai->ai_addr);
+#ifdef FAITH
+	if (translate == 1)
+		memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
+	else
+#endif
+	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(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;
+		}
+		strlcpy(ai->ai_canonname, pai->ai_canonname, l);
+	} 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((struct addrinfo *)ai, servname, 1);
+}
+
+static int
+get_port(struct addrinfo *ai, const char *servname, int matchonly)
+{
+	const char *proto;
+	struct servent *sp;
+	int port, error;
+	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:
+	case SOCK_SEQPACKET:
+		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;
+	}
+
+	error = str2number(servname, &port);
+	if (error == 0) {
+		if (!allownumeric)
+			return EAI_SERVICE;
+		if (port < 0 || port > 65535)
+			return EAI_SERVICE;
+		port = htons(port);
+	} else {
+		if (ai->ai_flags & AI_NUMERICSERV)
+			return EAI_NONAME;
+
+		switch (ai->ai_protocol) {
+		case IPPROTO_UDP:
+			proto = "udp";
+			break;
+		case IPPROTO_TCP:
+			proto = "tcp";
+			break;
+		case IPPROTO_SCTP:
+			proto = "sctp";
+			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;
+#ifdef INET6
+		case AF_INET6:
+			((struct sockaddr_in6 *)(void *)
+			    ai->ai_addr)->sin6_port = port;
+			break;
+#endif
+		}
+	}
+
+	return 0;
+}
+
+static const struct afd *
+find_afd(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.
+ *
+ * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
+ * _dns_getaddrinfo.
+ */
+static int
+addrconfig(struct addrinfo *pai)
+{
+	int s, af;
+
+	/*
+	 * TODO:
+	 * Note that implementation dependent test for address
+	 * configuration should be done everytime called
+	 * (or apropriate interval),
+	 * because addresses will be dynamically assigned or deleted.
+	 */
+	af = pai->ai_family;
+	if (af == AF_UNSPEC) {
+		if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
+			af = AF_INET;
+		else {
+			_close(s);
+			if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
+				af = AF_INET6;
+			else
+				_close(s);
+		}
+	}
+	if (af != AF_UNSPEC) {
+		if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
+			return 0;
+		_close(s);
+	}
+	pai->ai_family = af;
+	return 1;
+}
+
+#ifdef INET6
+/* convert a string to a scope identifier. XXX: IPv6 specific */
+static int
+ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid)
+{
+	u_long lscopeid;
+	struct in6_addr *a6;
+	char *ep;
+
+	a6 = &sin6->sin6_addr;
+
+	/* empty scopeid portion is invalid */
+	if (*scope == '\0')
+		return -1;
+
+	if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
+		/*
+		 * We currently assume a one-to-one mapping between links
+		 * and interfaces, so we simply use interface indices for
+		 * like-local scopes.
+		 */
+		*scopeid = if_nametoindex(scope);
+		if (*scopeid == 0)
+			goto trynumeric;
+		return 0;
+	}
+
+	/* 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 = (u_int32_t)(lscopeid & 0xffffffffUL);
+	if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid)
+		return 0;
+	else
+		return -1;
+}
+#endif
+
+
+#ifdef NS_CACHING
+static int
+addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap,
+    void *cache_mdata)
+{
+	res_state statp;
+	u_long res_options;
+
+	const int op_id = 0;	/* identifies the getaddrinfo for the cache */
+	char *hostname;
+	struct addrinfo *hints;
+
+	char *p;
+	int ai_flags, ai_family, ai_socktype, ai_protocol;
+	size_t desired_size, size;
+
+	statp = __res_state();
+	res_options = statp->options & (RES_RECURSE | RES_DEFNAMES |
+	    RES_DNSRCH | RES_NOALIASES | RES_USE_INET6);
+
+	hostname = va_arg(ap, char *);
+	hints = va_arg(ap, struct addrinfo *);
+
+	desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4;
+	if (hostname != NULL) {
+		size = strlen(hostname);
+		desired_size += size + 1;
+	} else
+		size = 0;
+
+	if (desired_size > *buffer_size) {
+		*buffer_size = desired_size;
+		return (NS_RETURN);
+	}
+
+	if (hints == NULL)
+		ai_flags = ai_family = ai_socktype = ai_protocol = 0;
+	else {
+		ai_flags = hints->ai_flags;
+		ai_family = hints->ai_family;
+		ai_socktype = hints->ai_socktype;
+		ai_protocol = hints->ai_protocol;
+	}
+
+	p = buffer;
+	memcpy(p, &res_options, sizeof(res_options));
+	p += sizeof(res_options);
+
+	memcpy(p, &op_id, sizeof(int));
+	p += sizeof(int);
+
+	memcpy(p, &ai_flags, sizeof(int));
+	p += sizeof(int);
+
+	memcpy(p, &ai_family, sizeof(int));
+	p += sizeof(int);
+
+	memcpy(p, &ai_socktype, sizeof(int));
+	p += sizeof(int);
+
+	memcpy(p, &ai_protocol, sizeof(int));
+	p += sizeof(int);
+
+	if (hostname != NULL)
+		memcpy(p, hostname, size);
+
+	*buffer_size = desired_size;
+	return (NS_SUCCESS);
+}
+
+static int
+addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval,
+    va_list ap, void *cache_mdata)
+{
+	struct addrinfo	*ai, *cai;
+	char *p;
+	size_t desired_size, size, ai_size;
+
+	ai = *((struct addrinfo **)retval);
+
+	desired_size = sizeof(size_t);
+	ai_size = 0;
+	for (cai = ai; cai != NULL; cai = cai->ai_next) {
+		desired_size += sizeof(struct addrinfo) + cai->ai_addrlen;
+		if (cai->ai_canonname != NULL)
+			desired_size += sizeof(size_t) +
+			    strlen(cai->ai_canonname);
+		++ai_size;
+	}
+
+	if (desired_size > *buffer_size) {
+		/* this assignment is here for future use */
+		errno = ERANGE;
+		*buffer_size = desired_size;
+		return (NS_RETURN);
+	}
+
+	memset(buffer, 0, desired_size);
+	p = buffer;
+
+	memcpy(p, &ai_size, sizeof(size_t));
+	p += sizeof(size_t);
+	for (cai = ai; cai != NULL; cai = cai->ai_next) {
+		memcpy(p, cai, sizeof(struct addrinfo));
+		p += sizeof(struct addrinfo);
+
+		memcpy(p, cai->ai_addr, cai->ai_addrlen);
+		p += cai->ai_addrlen;
+
+		if (cai->ai_canonname != NULL) {
+			size = strlen(cai->ai_canonname);
+			memcpy(p, &size, sizeof(size_t));
+			p += sizeof(size_t);
+
+			memcpy(p, cai->ai_canonname, size);
+			p += size;
+		}
+	}
+
+	return (NS_SUCCESS);
+}
+
+static int
+addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval,
+    va_list ap, void *cache_mdata)
+{
+	struct addrinfo	new_ai, *result, *sentinel, *lasts;
+
+	char *p;
+	size_t ai_size, ai_i, size;
+
+	p = buffer;
+	memcpy(&ai_size, p, sizeof(size_t));
+	p += sizeof(size_t);
+
+	result = NULL;
+	lasts = NULL;
+	for (ai_i = 0; ai_i < ai_size; ++ai_i) {
+		memcpy(&new_ai, p, sizeof(struct addrinfo));
+		p += sizeof(struct addrinfo);
+		size = new_ai.ai_addrlen + sizeof(struct addrinfo) +
+			_ALIGNBYTES;
+
+		sentinel = (struct addrinfo *)malloc(size);
+		memset(sentinel, 0, size);
+
+		memcpy(sentinel, &new_ai, sizeof(struct addrinfo));
+		sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel +
+		    sizeof(struct addrinfo));
+
+		memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen);
+		p += new_ai.ai_addrlen;
+
+		if (new_ai.ai_canonname != NULL) {
+			memcpy(&size, p, sizeof(size_t));
+			p += sizeof(size_t);
+
+			sentinel->ai_canonname = (char *)malloc(size + 1);
+			memset(sentinel->ai_canonname, 0, size + 1);
+
+			memcpy(sentinel->ai_canonname, p, size);
+			p += size;
+		}
+
+		if (result == NULL) {
+			result = sentinel;
+			lasts = sentinel;
+		} else {
+			lasts->ai_next = sentinel;
+			lasts = sentinel;
+		}
+	}
+
+	*((struct addrinfo **)retval) = result;
+	return (NS_SUCCESS);
+}
+#endif /* NS_CACHING */
+
+/*
+ * FQDN hostname, DNS lookup
+ */
+static int
+explore_fqdn(const struct addrinfo *pai, const char *hostname,
+    const char *servname, struct addrinfo **res)
+{
+	struct addrinfo *result;
+	struct addrinfo *cur;
+	int error = 0;
+
+#ifdef NS_CACHING
+	static const nss_cache_info cache_info =
+	NS_COMMON_CACHE_INFO_INITIALIZER(
+		hosts, NULL, addrinfo_id_func, addrinfo_marshal_func,
+		addrinfo_unmarshal_func);
+#endif
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_files_getaddrinfo, NULL)
+		{ NSSRC_DNS, _dns_getaddrinfo, NULL },	/* force -DHESIOD */
+		NS_NIS_CB(_yp_getaddrinfo, NULL)
+#ifdef NS_CACHING
+		NS_CACHE_CB(&cache_info)
+#endif
+		{ 0 }
+	};
+
+	result = NULL;
+
+	/*
+	 * if the servname does not match socktype/protocol, ignore it.
+	 */
+	if (get_portmatch(pai, servname) != 0)
+		return 0;
+
+	switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
+			default_dns_files, hostname, pai)) {
+	case NS_TRYAGAIN:
+		error = EAI_AGAIN;
+		goto free;
+	case NS_UNAVAIL:
+		error = EAI_FAIL;
+		goto free;
+	case NS_NOTFOUND:
+		error = EAI_NONAME;
+		goto free;
+	case NS_SUCCESS:
+		error = 0;
+		for (cur = result; cur; cur = cur->ai_next) {
+			GET_PORT(cur, servname);
+			/* canonname should be filled already */
+		}
+		break;
+	}
+
+	*res = result;
+
+	return 0;
+
+free:
+	if (result)
+		freeaddrinfo(result);
+	return error;
+}
+
+#ifdef DEBUG
+static const char AskedForGot[] =
+	"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
+#endif
+
+static struct addrinfo *
+getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
+    const struct addrinfo *pai, res_state res)
+{
+	struct addrinfo sentinel, *cur;
+	struct addrinfo ai;
+	const struct afd *afd;
+	char *canonname;
+	const HEADER *hp;
+	const u_char *cp;
+	int n;
+	const u_char *eom;
+	char *bp, *ep;
+	int type, class, ancount, qdcount;
+	int haveanswer, had_error;
+	char tbuf[MAXDNAME];
+	int (*name_ok)(const char *);
+	char hostbuf[8*1024];
+
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+	canonname = NULL;
+	eom = answer->buf + anslen;
+	switch (qtype) {
+	case T_A:
+	case T_AAAA:
+	case T_ANY:	/*use T_ANY only for T_A/T_AAAA lookup*/
+		name_ok = res_hnok;
+		break;
+	default:
+		return (NULL);	/* XXX should be abort(); */
+	}
+	/*
+	 * find first satisfactory answer
+	 */
+	hp = &answer->hdr;
+	ancount = ntohs(hp->ancount);
+	qdcount = ntohs(hp->qdcount);
+	bp = hostbuf;
+	ep = hostbuf + sizeof hostbuf;
+	cp = answer->buf + HFIXEDSZ;
+	if (qdcount != 1) {
+		RES_SET_H_ERRNO(res, NO_RECOVERY);
+		return (NULL);
+	}
+	n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
+	if ((n < 0) || !(*name_ok)(bp)) {
+		RES_SET_H_ERRNO(res, NO_RECOVERY);
+		return (NULL);
+	}
+	cp += n + QFIXEDSZ;
+	if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
+		/* res_send() has already verified that the query name is the
+		 * same as the one we sent; this just gets the expanded name
+		 * (i.e., with the succeeding search-domain tacked on).
+		 */
+		n = strlen(bp) + 1;		/* for the \0 */
+		if (n >= MAXHOSTNAMELEN) {
+			RES_SET_H_ERRNO(res, NO_RECOVERY);
+			return (NULL);
+		}
+		canonname = bp;
+		bp += n;
+		/* The qname can be abbreviated, but h_name is now absolute. */
+		qname = canonname;
+	}
+	haveanswer = 0;
+	had_error = 0;
+	while (ancount-- > 0 && cp < eom && !had_error) {
+		n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
+		if ((n < 0) || !(*name_ok)(bp)) {
+			had_error++;
+			continue;
+		}
+		cp += n;			/* name */
+		type = _getshort(cp);
+ 		cp += INT16SZ;			/* type */
+		class = _getshort(cp);
+ 		cp += INT16SZ + INT32SZ;	/* class, TTL */
+		n = _getshort(cp);
+		cp += INT16SZ;			/* len */
+		if (class != C_IN) {
+			/* XXX - debug? syslog? */
+			cp += n;
+			continue;		/* XXX - had_error++ ? */
+		}
+		if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
+		    type == T_CNAME) {
+			n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
+			if ((n < 0) || !(*name_ok)(tbuf)) {
+				had_error++;
+				continue;
+			}
+			cp += n;
+			/* Get canonical name. */
+			n = strlen(tbuf) + 1;	/* for the \0 */
+			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
+				had_error++;
+				continue;
+			}
+			strlcpy(bp, tbuf, ep - bp);
+			canonname = bp;
+			bp += n;
+			continue;
+		}
+		if (qtype == T_ANY) {
+			if (!(type == T_A || type == T_AAAA)) {
+				cp += n;
+				continue;
+			}
+		} else if (type != qtype) {
+#ifdef DEBUG
+			if (type != T_KEY && type != T_SIG &&
+			    type != ns_t_dname)
+				syslog(LOG_NOTICE|LOG_AUTH,
+	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
+				       qname, p_class(C_IN), p_type(qtype),
+				       p_type(type));
+#endif
+			cp += n;
+			continue;		/* XXX - had_error++ ? */
+		}
+		switch (type) {
+		case T_A:
+		case T_AAAA:
+			if (strcasecmp(canonname, bp) != 0) {
+#ifdef DEBUG
+				syslog(LOG_NOTICE|LOG_AUTH,
+				       AskedForGot, canonname, bp);
+#endif
+				cp += n;
+				continue;	/* XXX - had_error++ ? */
+			}
+			if (type == T_A && n != INADDRSZ) {
+				cp += n;
+				continue;
+			}
+			if (type == T_AAAA && n != IN6ADDRSZ) {
+				cp += n;
+				continue;
+			}
+#ifdef FILTER_V4MAPPED
+			if (type == T_AAAA) {
+				struct in6_addr in6;
+				memcpy(&in6, cp, sizeof(in6));
+				if (IN6_IS_ADDR_V4MAPPED(&in6)) {
+					cp += n;
+					continue;
+				}
+			}
+#endif
+			if (!haveanswer) {
+				int nn;
+
+				canonname = bp;
+				nn = strlen(bp) + 1;	/* for the \0 */
+				bp += nn;
+			}
+
+			/* don't overwrite pai */
+			ai = *pai;
+			ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
+			afd = find_afd(ai.ai_family);
+			if (afd == NULL) {
+				cp += n;
+				continue;
+			}
+			cur->ai_next = get_ai(&ai, afd, (const char *)cp);
+			if (cur->ai_next == NULL)
+				had_error++;
+			while (cur && cur->ai_next)
+				cur = cur->ai_next;
+			cp += n;
+			break;
+		default:
+			abort();
+		}
+		if (!had_error)
+			haveanswer++;
+	}
+	if (haveanswer) {
+#if defined(RESOLVSORT)
+		/*
+		 * We support only IPv4 address for backward
+		 * compatibility against gethostbyname(3).
+		 */
+		if (res->nsort && qtype == T_A) {
+			if (addr4sort(&sentinel, res) < 0) {
+				freeaddrinfo(sentinel.ai_next);
+				RES_SET_H_ERRNO(res, NO_RECOVERY);
+				return NULL;
+			}
+		}
+#endif /*RESOLVSORT*/
+		if (!canonname)
+			(void)get_canonname(pai, sentinel.ai_next, qname);
+		else
+			(void)get_canonname(pai, sentinel.ai_next, canonname);
+		RES_SET_H_ERRNO(res, NETDB_SUCCESS);
+		return sentinel.ai_next;
+	}
+
+	RES_SET_H_ERRNO(res, NO_RECOVERY);
+	return NULL;
+}
+
+#ifdef RESOLVSORT
+struct addr_ptr {
+	struct addrinfo *ai;
+	int aval;
+};
+
+static int
+addr4sort(struct addrinfo *sentinel, res_state res)
+{
+	struct addrinfo *ai;
+	struct addr_ptr *addrs, addr;
+	struct sockaddr_in *sin;
+	int naddrs, i, j;
+	int needsort = 0;
+
+	if (!sentinel)
+		return -1;
+	naddrs = 0;
+	for (ai = sentinel->ai_next; ai; ai = ai->ai_next)
+		naddrs++;
+	if (naddrs < 2)
+		return 0;		/* We don't need sorting. */
+	if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL)
+		return -1;
+	i = 0;
+	for (ai = sentinel->ai_next; ai; ai = ai->ai_next) {
+		sin = (struct sockaddr_in *)ai->ai_addr;
+		for (j = 0; (unsigned)j < res->nsort; j++) {
+			if (res->sort_list[j].addr.s_addr ==
+			    (sin->sin_addr.s_addr & res->sort_list[j].mask))
+				break;
+		}
+		addrs[i].ai = ai;
+		addrs[i].aval = j;
+		if (needsort == 0 && i > 0 && j < addrs[i - 1].aval)
+			needsort = i;
+		i++;
+	}
+	if (!needsort) {
+		free(addrs);
+		return 0;
+	}
+
+	while (needsort < naddrs) {
+		for (j = needsort - 1; j >= 0; j--) {
+			if (addrs[j].aval > addrs[j+1].aval) {
+				addr = addrs[j];
+				addrs[j] = addrs[j + 1];
+				addrs[j + 1] = addr;
+			} else
+				break;
+		}
+		needsort++;
+	}
+
+	ai = sentinel;
+	for (i = 0; i < naddrs; ++i) {
+		ai->ai_next = addrs[i].ai;
+		ai = ai->ai_next;
+	}
+	ai->ai_next = NULL;
+	free(addrs);
+	return 0;
+}
+#endif /*RESOLVSORT*/
+
+/*ARGSUSED*/
+static int
+_dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
+{
+	struct addrinfo *ai;
+	querybuf *buf, *buf2;
+	const char *hostname;
+	const struct addrinfo *pai;
+	struct addrinfo sentinel, *cur;
+	struct res_target q, q2;
+	res_state res;
+
+	hostname = va_arg(ap, char *);
+	pai = va_arg(ap, const struct addrinfo *);
+
+	memset(&q, 0, sizeof(q));
+	memset(&q2, 0, sizeof(q2));
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+	buf = malloc(sizeof(*buf));
+	if (!buf) {
+		RES_SET_H_ERRNO(res, NETDB_INTERNAL);
+		return NS_NOTFOUND;
+	}
+	buf2 = malloc(sizeof(*buf2));
+	if (!buf2) {
+		free(buf);
+		RES_SET_H_ERRNO(res, NETDB_INTERNAL);
+		return NS_NOTFOUND;
+	}
+
+	switch (pai->ai_family) {
+	case AF_UNSPEC:
+		q.name = hostname;
+		q.qclass = C_IN;
+		q.qtype = T_A;
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
+		q.next = &q2;
+		q2.name = hostname;
+		q2.qclass = C_IN;
+		q2.qtype = T_AAAA;
+		q2.answer = buf2->buf;
+		q2.anslen = sizeof(buf2->buf);
+		break;
+	case AF_INET:
+		q.name = hostname;
+		q.qclass = C_IN;
+		q.qtype = T_A;
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
+		break;
+	case AF_INET6:
+		q.name = hostname;
+		q.qclass = C_IN;
+		q.qtype = T_AAAA;
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
+		break;
+	default:
+		free(buf);
+		free(buf2);
+		return NS_UNAVAIL;
+	}
+
+	res = __res_state();
+	if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) {
+		RES_SET_H_ERRNO(res, NETDB_INTERNAL);
+		free(buf);
+		free(buf2);
+		return NS_NOTFOUND;
+	}
+
+	if (res_searchN(hostname, &q, res) < 0) {
+		free(buf);
+		free(buf2);
+		return NS_NOTFOUND;
+	}
+	/* prefer IPv6 */
+	if (q.next) {
+		ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res);
+		if (ai) {
+			cur->ai_next = ai;
+			while (cur && cur->ai_next)
+				cur = cur->ai_next;
+		}
+	}
+	ai = getanswer(buf, q.n, q.name, q.qtype, pai, res);
+	if (ai)
+		cur->ai_next = ai;
+	free(buf);
+	free(buf2);
+	if (sentinel.ai_next == NULL)
+		switch (res->res_h_errno) {
+		case HOST_NOT_FOUND:
+			return NS_NOTFOUND;
+		case TRY_AGAIN:
+			return NS_TRYAGAIN;
+		default:
+			return NS_UNAVAIL;
+		}
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	return NS_SUCCESS;
+}
+
+static void
+_sethtent(FILE **hostf)
+{
+	if (!*hostf)
+		*hostf = fopen(_PATH_HOSTS, "r");
+	else
+		rewind(*hostf);
+}
+
+static void
+_endhtent(FILE **hostf)
+{
+	if (*hostf) {
+		(void) fclose(*hostf);
+		*hostf = NULL;
+	}
+}
+
+static struct addrinfo *
+_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai)
+{
+	char *p;
+	char *cp, *tname, *cname;
+	struct addrinfo hints, *res0, *res;
+	int error;
+	const char *addr;
+	char hostbuf[8*1024];
+
+	if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r")))
+		return (NULL);
+again:
+	if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf)))
+		return (NULL);
+	if (*p == '#')
+		goto again;
+	cp = strpbrk(p, "#\n");
+	if (cp != NULL)
+		*cp = '\0';
+	if (!(cp = strpbrk(p, " \t")))
+		goto again;
+	*cp++ = '\0';
+	addr = p;
+	cname = NULL;
+	/* if this is not something we're looking for, skip it. */
+	while (cp && *cp) {
+		if (*cp == ' ' || *cp == '\t') {
+			cp++;
+			continue;
+		}
+		tname = cp;
+		if (cname == NULL)
+			cname = cp;
+		if ((cp = strpbrk(cp, " \t")) != NULL)
+			*cp++ = '\0';
+		if (strcasecmp(name, tname) == 0)
+			goto found;
+	}
+	goto again;
+
+found:
+	/* we should not glob socktype/protocol here */
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = pai->ai_family;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = 0;
+	hints.ai_flags = AI_NUMERICHOST;
+	error = getaddrinfo(addr, "0", &hints, &res0);
+	if (error)
+		goto again;
+#ifdef FILTER_V4MAPPED
+	/* XXX should check all items in the chain */
+	if (res0->ai_family == AF_INET6 &&
+	    IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
+		freeaddrinfo(res0);
+		goto again;
+	}
+#endif
+	for (res = res0; res; res = res->ai_next) {
+		/* cover it up */
+		res->ai_flags = pai->ai_flags;
+		res->ai_socktype = pai->ai_socktype;
+		res->ai_protocol = pai->ai_protocol;
+
+		if (pai->ai_flags & AI_CANONNAME) {
+			if (get_canonname(pai, res, cname) != 0) {
+				freeaddrinfo(res0);
+				goto again;
+			}
+		}
+	}
+	return res0;
+}
+
+/*ARGSUSED*/
+static int
+_files_getaddrinfo(void *rv, void *cb_data, va_list ap)
+{
+	const char *name;
+	const struct addrinfo *pai;
+	struct addrinfo sentinel, *cur;
+	struct addrinfo *p;
+	FILE *hostf = NULL;
+
+	name = va_arg(ap, char *);
+	pai = va_arg(ap, struct addrinfo *);
+
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+	_sethtent(&hostf);
+	while ((p = _gethtent(&hostf, name, pai)) != NULL) {
+		cur->ai_next = p;
+		while (cur && cur->ai_next)
+			cur = cur->ai_next;
+	}
+	_endhtent(&hostf);
+
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	if (sentinel.ai_next == NULL)
+		return NS_NOTFOUND;
+	return NS_SUCCESS;
+}
+
+#ifdef YP
+/*ARGSUSED*/
+static struct addrinfo *
+_yphostent(char *line, const struct addrinfo *pai)
+{
+	struct addrinfo sentinel, *cur;
+	struct addrinfo hints, *res, *res0;
+	int error;
+	char *p = line;
+	const char *addr, *canonname;
+	char *nextline;
+	char *cp;
+
+	addr = canonname = NULL;
+
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+nextline:
+	/* terminate line */
+	cp = strchr(p, '\n');
+	if (cp) {
+		*cp++ = '\0';
+		nextline = cp;
+	} else
+		nextline = NULL;
+
+	cp = strpbrk(p, " \t");
+	if (cp == NULL) {
+		if (canonname == NULL)
+			return (NULL);
+		else
+			goto done;
+	}
+	*cp++ = '\0';
+
+	addr = p;
+
+	while (cp && *cp) {
+		if (*cp == ' ' || *cp == '\t') {
+			cp++;
+			continue;
+		}
+		if (!canonname)
+			canonname = cp;
+		if ((cp = strpbrk(cp, " \t")) != NULL)
+			*cp++ = '\0';
+	}
+
+	hints = *pai;
+	hints.ai_flags = AI_NUMERICHOST;
+	error = getaddrinfo(addr, NULL, &hints, &res0);
+	if (error == 0) {
+		for (res = res0; res; res = res->ai_next) {
+			/* cover it up */
+			res->ai_flags = pai->ai_flags;
+
+			if (pai->ai_flags & AI_CANONNAME)
+				(void)get_canonname(pai, res, canonname);
+		}
+	} else
+		res0 = NULL;
+	if (res0) {
+		cur->ai_next = res0;
+		while (cur && cur->ai_next)
+			cur = cur->ai_next;
+	}
+
+	if (nextline) {
+		p = nextline;
+		goto nextline;
+	}
+
+done:
+	return sentinel.ai_next;
+}
+
+/*ARGSUSED*/
+static int
+_yp_getaddrinfo(void *rv, void *cb_data, va_list ap)
+{
+	struct addrinfo sentinel, *cur;
+	struct addrinfo *ai = NULL;
+	char *ypbuf;
+	int ypbuflen, r;
+	const char *name;
+	const struct addrinfo *pai;
+	char *ypdomain;
+
+	if (_yp_check(&ypdomain) == 0)
+		return NS_UNAVAIL;
+
+	name = va_arg(ap, char *);
+	pai = va_arg(ap, const struct addrinfo *);
+
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+	/* hosts.byname is only for IPv4 (Solaris8) */
+	if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
+		r = yp_match(ypdomain, "hosts.byname", name,
+			(int)strlen(name), &ypbuf, &ypbuflen);
+		if (r == 0) {
+			struct addrinfo ai4;
+
+			ai4 = *pai;
+			ai4.ai_family = AF_INET;
+			ai = _yphostent(ypbuf, &ai4);
+			if (ai) {
+				cur->ai_next = ai;
+				while (cur && cur->ai_next)
+					cur = cur->ai_next;
+			}
+			free(ypbuf);
+		}
+	}
+
+	/* ipnodes.byname can hold both IPv4/v6 */
+	r = yp_match(ypdomain, "ipnodes.byname", name,
+		(int)strlen(name), &ypbuf, &ypbuflen);
+	if (r == 0) {
+		ai = _yphostent(ypbuf, pai);
+		if (ai)
+			cur->ai_next = ai;
+		free(ypbuf);
+	}
+
+	if (sentinel.ai_next == NULL) {
+		RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND);
+		return NS_NOTFOUND;
+	}
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	return NS_SUCCESS;
+}
+#endif
+
+/* resolver logic */
+
+/*
+ * Formulate a normal query, send, and await answer.
+ * Returned answer is placed in supplied buffer "answer".
+ * Perform preliminary check of answer, returning success only
+ * if no error is indicated and the answer count is nonzero.
+ * Return the size of the response on success, -1 on error.
+ * Error number is left in h_errno.
+ *
+ * Caller must parse answer and determine whether it answers the question.
+ */
+static int
+res_queryN(const char *name, struct res_target *target, res_state res)
+{
+	u_char *buf;
+	HEADER *hp;
+	int n;
+	u_int oflags;
+	struct res_target *t;
+	int rcode;
+	int ancount;
+
+	rcode = NOERROR;
+	ancount = 0;
+
+	buf = malloc(MAXPACKET);
+	if (!buf) {
+		RES_SET_H_ERRNO(res, NETDB_INTERNAL);
+		return -1;
+	}
+
+	for (t = target; t; t = t->next) {
+		int class, type;
+		u_char *answer;
+		int anslen;
+
+		hp = (HEADER *)(void *)t->answer;
+
+		/* make it easier... */
+		class = t->qclass;
+		type = t->qtype;
+		answer = t->answer;
+		anslen = t->anslen;
+
+		oflags = res->_flags;
+
+again:
+		hp->rcode = NOERROR;	/* default */
+
+#ifdef DEBUG
+		if (res->options & RES_DEBUG)
+			printf(";; res_query(%s, %d, %d)\n", name, class, type);
+#endif
+
+		n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
+		    buf, MAXPACKET);
+		if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 &&
+		    (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U)
+			n = res_nopt(res, n, buf, MAXPACKET, anslen);
+		if (n <= 0) {
+#ifdef DEBUG
+			if (res->options & RES_DEBUG)
+				printf(";; res_query: mkquery failed\n");
+#endif
+			free(buf);
+			RES_SET_H_ERRNO(res, NO_RECOVERY);
+			return (n);
+		}
+		n = res_nsend(res, buf, n, answer, anslen);
+		if (n < 0) {
+			/*
+			 * if the query choked with EDNS0, retry
+			 * without EDNS0
+			 */
+			if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC))
+			    != 0U &&
+			    ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) {
+				res->_flags |= RES_F_EDNS0ERR;
+				if (res->options & RES_DEBUG)
+					printf(";; res_nquery: retry without EDNS0\n");
+				goto again;
+			}
+			rcode = hp->rcode;	/* record most recent error */
+#ifdef DEBUG
+			if (res->options & RES_DEBUG)
+				printf(";; res_query: send error\n");
+#endif
+			continue;
+		}
+
+		if (n > anslen)
+			hp->rcode = FORMERR; /* XXX not very informative */
+		if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+			rcode = hp->rcode;	/* record most recent error */
+#ifdef DEBUG
+			if (res->options & RES_DEBUG)
+				printf(";; rcode = %u, ancount=%u\n", hp->rcode,
+				    ntohs(hp->ancount));
+#endif
+			continue;
+		}
+
+		ancount += ntohs(hp->ancount);
+
+		t->n = n;
+	}
+
+	free(buf);
+
+	if (ancount == 0) {
+		switch (rcode) {
+		case NXDOMAIN:
+			RES_SET_H_ERRNO(res, HOST_NOT_FOUND);
+			break;
+		case SERVFAIL:
+			RES_SET_H_ERRNO(res, TRY_AGAIN);
+			break;
+		case NOERROR:
+			RES_SET_H_ERRNO(res, NO_DATA);
+			break;
+		case FORMERR:
+		case NOTIMP:
+		case REFUSED:
+		default:
+			RES_SET_H_ERRNO(res, NO_RECOVERY);
+			break;
+		}
+		return (-1);
+	}
+	return (ancount);
+}
+
+/*
+ * Formulate a normal query, send, and retrieve answer in supplied buffer.
+ * Return the size of the response on success, -1 on error.
+ * If enabled, implement search rules until answer or unrecoverable failure
+ * is detected.  Error code, if any, is left in h_errno.
+ */
+static int
+res_searchN(const char *name, struct res_target *target, res_state res)
+{
+	const char *cp, * const *domain;
+	HEADER *hp = (HEADER *)(void *)target->answer;	/*XXX*/
+	u_int dots;
+	int trailing_dot, ret, saved_herrno;
+	int got_nodata = 0, got_servfail = 0, root_on_list = 0;
+	int tried_as_is = 0;
+	int searched = 0;
+	char abuf[MAXDNAME];
+
+	errno = 0;
+	RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */
+	dots = 0;
+	for (cp = name; *cp; cp++)
+		dots += (*cp == '.');
+	trailing_dot = 0;
+	if (cp > name && *--cp == '.')
+		trailing_dot++;
+
+	/*
+	 * if there aren't any dots, it could be a user-level alias
+	 */
+	if (!dots &&
+	    (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL)
+		return (res_queryN(cp, target, res));
+
+	/*
+	 * If there are enough dots in the name, let's just give it a
+	 * try 'as is'. The threshold can be set with the "ndots" option.
+	 * Also, query 'as is', if there is a trailing dot in the name.
+	 */
+	saved_herrno = -1;
+	if (dots >= res->ndots || trailing_dot) {
+		ret = res_querydomainN(name, NULL, target, res);
+		if (ret > 0 || trailing_dot)
+			return (ret);
+		if (errno == ECONNREFUSED) {
+			RES_SET_H_ERRNO(res, TRY_AGAIN);
+			return (-1);
+		}
+		switch (res->res_h_errno) {
+		case NO_DATA:
+		case HOST_NOT_FOUND:
+			break;
+		case TRY_AGAIN:
+			if (hp->rcode == SERVFAIL)
+				break;
+			/* FALLTHROUGH */
+		default:
+			return (-1);
+		}
+		saved_herrno = res->res_h_errno;
+		tried_as_is++;
+	}
+
+	/*
+	 * We do at least one level of search if
+	 *	- there is no dot and RES_DEFNAME is set, or
+	 *	- there is at least one dot, there is no trailing dot,
+	 *	  and RES_DNSRCH is set.
+	 */
+	if ((!dots && (res->options & RES_DEFNAMES)) ||
+	    (dots && !trailing_dot && (res->options & RES_DNSRCH))) {
+		int done = 0;
+
+		for (domain = (const char * const *)res->dnsrch;
+		   *domain && !done;
+		   domain++) {
+			searched = 1;
+
+			if (domain[0][0] == '\0' ||
+			    (domain[0][0] == '.' && domain[0][1] == '\0'))
+				root_on_list++;
+
+			if (root_on_list && tried_as_is)
+				continue;
+
+			ret = res_querydomainN(name, *domain, target, res);
+			if (ret > 0)
+				return (ret);
+
+			/*
+			 * If no server present, give up.
+			 * If name isn't found in this domain,
+			 * keep trying higher domains in the search list
+			 * (if that's enabled).
+			 * On a NO_DATA error, keep trying, otherwise
+			 * a wildcard entry of another type could keep us
+			 * from finding this entry higher in the domain.
+			 * If we get some other error (negative answer or
+			 * server failure), then stop searching up,
+			 * but try the input name below in case it's
+			 * fully-qualified.
+			 */
+			if (errno == ECONNREFUSED) {
+				RES_SET_H_ERRNO(res, TRY_AGAIN);
+				return (-1);
+			}
+
+			switch (res->res_h_errno) {
+			case NO_DATA:
+				got_nodata++;
+				/* FALLTHROUGH */
+			case HOST_NOT_FOUND:
+				/* keep trying */
+				break;
+			case TRY_AGAIN:
+				got_servfail++;
+				if (hp->rcode == SERVFAIL) {
+					/* try next search element, if any */
+					break;
+				}
+				/* FALLTHROUGH */
+			default:
+				/* anything else implies that we're done */
+				done++;
+			}
+			/*
+			 * if we got here for some reason other than DNSRCH,
+			 * we only wanted one iteration of the loop, so stop.
+			 */
+			if (!(res->options & RES_DNSRCH))
+			        done++;
+		}
+	}
+
+	switch (res->res_h_errno) {
+	case NO_DATA:
+	case HOST_NOT_FOUND:
+		break;
+	case TRY_AGAIN:
+		if (hp->rcode == SERVFAIL)
+			break;
+		/* FALLTHROUGH */
+	default:
+		goto giveup;
+	}
+
+	/*
+	 * If the query has not already been tried as is then try it
+	 * unless RES_NOTLDQUERY is set and there were no dots.
+	 */
+	if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) &&
+	    !(tried_as_is || root_on_list)) {
+		ret = res_querydomainN(name, NULL, target, res);
+		if (ret > 0)
+			return (ret);
+	}
+
+	/*
+	 * if we got here, we didn't satisfy the search.
+	 * if we did an initial full query, return that query's h_errno
+	 * (note that we wouldn't be here if that query had succeeded).
+	 * else if we ever got a nodata, send that back as the reason.
+	 * else send back meaningless h_errno, that being the one from
+	 * the last DNSRCH we did.
+	 */
+giveup:
+	if (saved_herrno != -1)
+		RES_SET_H_ERRNO(res, saved_herrno);
+	else if (got_nodata)
+		RES_SET_H_ERRNO(res, NO_DATA);
+	else if (got_servfail)
+		RES_SET_H_ERRNO(res, TRY_AGAIN);
+	return (-1);
+}
+
+/*
+ * Perform a call on res_query on the concatenation of name and domain,
+ * removing a trailing dot from name if domain is NULL.
+ */
+static int
+res_querydomainN(const char *name, const char *domain,
+    struct res_target *target, res_state res)
+{
+	char nbuf[MAXDNAME];
+	const char *longname = nbuf;
+	size_t n, d;
+
+#ifdef DEBUG
+	if (res->options & RES_DEBUG)
+		printf(";; res_querydomain(%s, %s)\n",
+			name, domain?domain:"<Nil>");
+#endif
+	if (domain == NULL) {
+		/*
+		 * Check for trailing '.';
+		 * copy without '.' if present.
+		 */
+		n = strlen(name);
+		if (n >= MAXDNAME) {
+			RES_SET_H_ERRNO(res, NO_RECOVERY);
+			return (-1);
+		}
+		if (n > 0 && name[--n] == '.') {
+			strncpy(nbuf, name, n);
+			nbuf[n] = '\0';
+		} else
+			longname = name;
+	} else {
+		n = strlen(name);
+		d = strlen(domain);
+		if (n + d + 1 >= MAXDNAME) {
+			RES_SET_H_ERRNO(res, NO_RECOVERY);
+			return (-1);
+		}
+		snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
+	}
+	return (res_queryN(longname, target, res));
+}