Add nsswitch support. By creating an /etc/nsswitch.conf file, you can

configure FreeBSD so that various databases such as passwd and group can be
looked up using flat files, NIS, or Hesiod.

= Hesiod has been added to libc (see hesiod(3)).

= A library routine for parsing nsswitch.conf and invoking callback
  functions as specified has been added to libc (see nsdispatch(3)).

= The following C library functions have been modified to use nsdispatch:
    . getgrent, getgrnam, getgrgid
    . getpwent, getpwnam, getpwuid
    . getusershell
    . getaddrinfo
    . gethostbyname, gethostbyname2, gethostbyaddr
    . getnetbyname, getnetbyaddr
    . getipnodebyname, getipnodebyaddr, getnodebyname, getnodebyaddr

= host.conf has been removed from src/etc.  rc.network has been modified
  to warn that host.conf is no longer used at boot time.  In addition, if
  there is a host.conf but no nsswitch.conf, the latter is created at boot
  time from the former.

Obtained from:	NetBSD

22 files changed, 2217 insertions, 725 deletions

diff --git a/lib/libc/net/Makefile.inc b/lib/libc/net/Makefile.inc
index 1d3ab66..3f84d10 100644
--- a/lib/libc/net/Makefile.inc
+++ b/lib/libc/net/Makefile.inc
@@ -9,19 +9,32 @@ SRCS+=	addr2ascii.c ascii2addr.c base64.c ether_addr.c getaddrinfo.c \
 	getifaddrs.c getnameinfo.c \
 	getnetbydns.c getnetbyht.c getnetbynis.c getnetnamadr.c \
 	getproto.c getprotoent.c getprotoname.c getservbyname.c \
-	getservbyport.c getservent.c herror.c inet_addr.c ifname.c \
-	inet_lnaof.c \
+	getservbyport.c getservent.c herror.c hesiod.c inet_addr.c \
+	ifname.c inet_lnaof.c \
 	inet_makeaddr.c inet_net_ntop.c inet_net_pton.c inet_neta.c \
 	inet_netof.c inet_network.c inet_ntoa.c inet_ntop.c \
 	inet_pton.c ip6opt.c linkaddr.c map_v4v6.c name6.c ns_addr.c \
 	ns_name.c ns_netint.c \
-	ns_ntoa.c ns_parse.c ns_print.c ns_ttl.c nsap_addr.c \
-	rcmd.c recv.c res_comp.c res_data.c res_debug.c \
+	ns_ntoa.c ns_parse.c ns_print.c ns_ttl.c \
+	nsdispatch.c nslexer.c nsparser.c \
+	nsap_addr.c rcmd.c recv.c res_comp.c res_data.c res_debug.c \
 	res_init.c res_mkquery.c res_mkupdate.c res_query.c res_send.c \
 	res_update.c rthdr.c send.c vars.c
 # not supported: iso_addr.c 
 
-CFLAGS+=-DINET6
+CFLAGS+=-DINET6 -I${.OBJDIR}
+
+YFLAGS+=-p_nsyy
+LFLAGS+=-P_nsyy
+
+CLEANFILES+=nsparser.c nslexer.c nsparser.h
+
+nsparser.h: nsparser.c
+	mv y.tab.h ${.TARGET}
+
+nslexer.c: nslexer.l nsparser.h
+	${LEX} ${LFLAGS} -o/dev/stdout ${.IMPSRC} | \
+		sed -e '/YY_BUF_SIZE/s/16384/1024/' >${.TARGET}
 
 # machine-dependent net sources
 .include "${.CURDIR}/../libc/${MACHINE_ARCH}/net/Makefile.inc"
@@ -29,9 +42,10 @@ CFLAGS+=-DINET6
 .if ${LIB} == "c"
 MAN3+=	addr2ascii.3 byteorder.3 ethers.3 getaddrinfo.3 gethostbyname.3 \
 	getifaddrs.3 getipnodebyname.3 \
-	getnameinfo.3 getnetent.3 getprotoent.3 getservent.3 if_indextoname.3 \
+	getnameinfo.3 getnetent.3 getprotoent.3 getservent.3 hesiod.3 \
+	if_indextoname.3 \
 	inet.3 inet6_option_space.3 inet6_rthdr_space.3 linkaddr.3 \
-	rcmd.3 resolver.3
+	nsdispatch.3 rcmd.3 resolver.3
 # not installed: iso_addr.3 ns.3
 
 MLINKS+=addr2ascii.3 ascii2addr.3
diff --git a/lib/libc/net/getaddrinfo.3 b/lib/libc/net/getaddrinfo.3
index 1a0b5f4..deb575f 100644
--- a/lib/libc/net/getaddrinfo.3
+++ b/lib/libc/net/getaddrinfo.3
@@ -496,9 +496,9 @@ freeaddrinfo(res0);
 .Ed
 .\"
 .Sh FILES
-.Bl -tag -width /etc/resolv.conf -compact
+.Bl -tag -width /etc/nsswitch.conf -compact
 .It Pa /etc/hosts
-.It Pa /etc/host.conf
+.It Pa /etc/nsswitch.conf
 .It Pa /etc/resolv.conf
 .El
 .\"
diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c
index 6d23544..10ddd3a 100644
--- a/lib/libc/net/getaddrinfo.c
+++ b/lib/libc/net/getaddrinfo.c
@@ -1,4 +1,4 @@
-/*	$FreeBSD$	*/
+/*      $FreeBSD$        */
 /*	$KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $	*/
 
 /*
@@ -103,14 +103,18 @@
 #include <stdio.h>
 #include <errno.h>
 
+#include <syslog.h>
+#include <stdarg.h>
+#include <nsswitch.h>
+
 #if defined(__KAME__) && defined(INET6)
 # define FAITH
 #endif
 
-#define	SUCCESS 0
-#define	ANY 0
-#define	YES 1
-#define	NO  0
+#define SUCCESS 0
+#define ANY 0
+#define YES 1
+#define NO  0
 
 static const char in_addrany[] = { 0, 0, 0, 0 };
 static const char in6_addrany[] = {
@@ -127,7 +131,7 @@ static const struct afd {
 	int a_socklen;
 	int a_off;
 	const char *a_addrany;
-	const char *a_loopback;
+	const char *a_loopback;	
 	int a_scoped;
 } afdl [] = {
 #ifdef INET6
@@ -153,9 +157,9 @@ struct explore {
 	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)
+#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[] = {
@@ -177,11 +181,17 @@ static const struct explore explore[] = {
 };
 
 #ifdef INET6
-#define	PTON_MAX	16
+#define PTON_MAX	16
 #else
-#define	PTON_MAX	4
+#define PTON_MAX	4
 #endif
 
+static const ns_src default_dns_files[] = {
+	{ NSSRC_FILES, 	NS_SUCCESS },
+	{ NSSRC_DNS, 	NS_SUCCESS },
+	{ 0 }
+};
+
 #if PACKETSZ > 1024
 #define MAXPACKET	PACKETSZ
 #else
@@ -223,24 +233,22 @@ static int addrconfig __P((struct addrinfo *));
 static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *));
 #endif
 
-static struct addrinfo *getanswer __P((const querybuf *, int, const char *,
-				       int, const struct addrinfo *));
-static int _dns_getaddrinfo __P((const struct addrinfo *, const char *,
-				 struct addrinfo **));
-static struct addrinfo *_gethtent __P((FILE *fp, const char *,
-				       const struct addrinfo *));
-static int _files_getaddrinfo __P((const struct addrinfo *, const char *,
-				   struct addrinfo **));
+static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int,
+	const struct addrinfo *));
+static int _dns_getaddrinfo __P((void *, void *, va_list));
+static void _sethtent __P((void));
+static void _endhtent __P((void));
+static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *));
+static int _files_getaddrinfo __P((void *, void *, va_list));
 #ifdef YP
-static int _nis_getaddrinfo __P((const struct addrinfo *, const char *,
-				 struct addrinfo **));
+static struct addrinfo *_yphostent __P((char *, const struct addrinfo *));
+static int _yp_getaddrinfo __P((void *, void *, va_list));
 #endif
 
 static int res_queryN __P((const char *, struct res_target *));
 static int res_searchN __P((const char *, struct res_target *));
 static int res_querydomainN __P((const char *, const char *,
-				 struct res_target *));
-
+	struct res_target *));
 
 static char *ai_errlist[] = {
 	"Success",
@@ -263,35 +271,9 @@ static char *ai_errlist[] = {
 	"Unknown error", 				/* EAI_MAX        */
 };
 
-/*
- * Select order host function.
- */
-#define	MAXHOSTCONF	4
-
-#ifndef HOSTCONF
-#  define	HOSTCONF	"/etc/host.conf"
-#endif /* !HOSTCONF */
-
-struct _hostconf {
-	int (*byname)(const struct addrinfo *, const char *,
-		      struct addrinfo **);
-};
-
-/* default order */
-static struct _hostconf _hostconf[MAXHOSTCONF] = {
-	_dns_getaddrinfo,
-	_files_getaddrinfo,
-#ifdef ICMPNL
-	NULL,
-#endif /* ICMPNL */
-};
-
-static int	_hostconf_init_done;
-static void	_hostconf_init(void);
-
 /* XXX macros that make external reference is BAD. */
 
-#define	GET_AI(ai, afd, addr) \
+#define GET_AI(ai, afd, addr) \
 do { \
 	/* external reference: pai, error, and label free */ \
 	(ai) = get_ai(pai, (afd), (addr)); \
@@ -301,7 +283,7 @@ do { \
 	} \
 } while (/*CONSTCOND*/0)
 
-#define	GET_PORT(ai, serv) \
+#define GET_PORT(ai, serv) \
 do { \
 	/* external reference: error and label free */ \
 	error = get_port((ai), (serv), 0); \
@@ -309,7 +291,7 @@ do { \
 		goto free; \
 } while (/*CONSTCOND*/0)
 
-#define	GET_CANONNAME(ai, str) \
+#define GET_CANONNAME(ai, str) \
 do { \
 	/* external reference: pai, error and label free */ \
 	error = get_canonname(pai, (ai), (str)); \
@@ -317,7 +299,7 @@ do { \
 		goto free; \
 } while (/*CONSTCOND*/0)
 
-#define	ERR(err) \
+#define ERR(err) \
 do { \
 	/* external reference: error, and label bad */ \
 	error = (err); \
@@ -325,9 +307,9 @@ do { \
 	/*NOTREACHED*/ \
 } while (/*CONSTCOND*/0)
 
-#define	MATCH_FAMILY(x, y, w) \
+#define MATCH_FAMILY(x, y, w) \
 	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
-#define	MATCH(x, y, w) \
+#define MATCH(x, y, w) \
 	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
 
 char *
@@ -470,7 +452,7 @@ getaddrinfo(hostname, servname, hints, res)
 	 */
 	if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
 #ifdef PF_INET6
-	    || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
+	 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
 #endif
 	    ) {
 		ai0 = *pai;	/* backup *pai */
@@ -501,11 +483,9 @@ getaddrinfo(hostname, servname, hints, res)
 
 		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
 			continue;
-		if (!MATCH(pai->ai_socktype, ex->e_socktype,
-			   WILD_SOCKTYPE(ex)))
+		if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
 			continue;
-		if (!MATCH(pai->ai_protocol, ex->e_protocol,
-			   WILD_PROTOCOL(ex)))
+		if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
 			continue;
 
 		if (pai->ai_family == PF_UNSPEC)
@@ -518,8 +498,7 @@ getaddrinfo(hostname, servname, hints, res)
 		if (hostname == NULL)
 			error = explore_null(pai, servname, &cur->ai_next);
 		else
-			error = explore_numeric_scope(pai, hostname, servname,
-						      &cur->ai_next);
+			error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
 
 		if (error)
 			goto free;
@@ -561,11 +540,11 @@ getaddrinfo(hostname, servname, hints, res)
 			continue;
 
 		if (!MATCH(pai->ai_socktype, ex->e_socktype,
-			   WILD_SOCKTYPE(ex))) {
+				WILD_SOCKTYPE(ex))) {
 			continue;
 		}
 		if (!MATCH(pai->ai_protocol, ex->e_protocol,
-			   WILD_PROTOCOL(ex))) {
+				WILD_PROTOCOL(ex))) {
 			continue;
 		}
 
@@ -574,7 +553,8 @@ getaddrinfo(hostname, servname, hints, res)
 		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
 			pai->ai_protocol = ex->e_protocol;
 
-		error = explore_fqdn(pai, hostname, servname, &cur->ai_next);
+		error = explore_fqdn(pai, hostname, servname,
+			&cur->ai_next);
 
 		while (cur && cur->ai_next)
 			cur = cur->ai_next;
@@ -602,82 +582,6 @@ getaddrinfo(hostname, servname, hints, res)
 	return error;
 }
 
-static char *
-_hgetword(char **pp)
-{
-	char c, *p, *ret;
-	const char *sp;
-	static const char sep[] = "# \t\n";
-
-	ret = NULL;
-	for (p = *pp; (c = *p) != '\0'; p++) {
-		for (sp = sep; *sp != '\0'; sp++) {
-			if (c == *sp)
-				break;
-		}
-		if (c == '#')
-			p[1] = '\0';	/* ignore rest of line */
-		if (ret == NULL) {
-			if (*sp == '\0')
-				ret = p;
-		} else {
-			if (*sp != '\0') {
-				*p++ = '\0';
-				break;
-			}
-		}
-	}
-	*pp = p;
-	if (ret == NULL || *ret == '\0')
-		return NULL;
-	return ret;
-}
-
-/*
- * Initialize hostconf structure.
- */
-
-static void
-_hostconf_init(void)
-{
-	FILE *fp;
-	int n;
-	char *p, *line;
-	char buf[BUFSIZ];
-
-	_hostconf_init_done = 1;
-	n = 0;
-	p = HOSTCONF;
-	if ((fp = fopen(p, "r")) == NULL)
-		return;
-	while (n < MAXHOSTCONF && fgets(buf, sizeof(buf), fp)) {
-		line = buf;
-		if ((p = _hgetword(&line)) == NULL)
-			continue;
-		do {
-			if (strcmp(p, "hosts") == 0
-			||  strcmp(p, "local") == 0
-			||  strcmp(p, "file") == 0
-			||  strcmp(p, "files") == 0)
-				_hostconf[n++].byname = _files_getaddrinfo;
-			else if (strcmp(p, "dns") == 0
-			     ||  strcmp(p, "bind") == 0)
-				_hostconf[n++].byname = _dns_getaddrinfo;
-#ifdef YP
-			else if (strcmp(p, "nis") == 0)
-				_hostconf[n++].byname = _nis_getaddrinfo;
-#endif
-		} while ((p = _hgetword(&line)) != NULL);
-	}
-	fclose(fp);
-	if (n < 0) {
-		/* no keyword found. do not change default configuration */
-		return;
-	}
-	for (; n < MAXHOSTCONF; n++)
-		_hostconf[n].byname = NULL;
-}
-
 /*
  * FQDN hostname, DNS lookup
  */
@@ -690,10 +594,15 @@ explore_fqdn(pai, hostname, servname, res)
 {
 	struct addrinfo *result;
 	struct addrinfo *cur;
-	int error = 0, i;
+	int error = 0;
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_files_getaddrinfo, NULL)
+		{ NSSRC_DNS, _dns_getaddrinfo, NULL },	/* force -DHESIOD */
+		NS_NIS_CB(_yp_getaddrinfo, NULL)
+		{ 0 }
+	};
 
 	result = NULL;
-	*res = NULL;
 
 	/*
 	 * if the servname does not match socktype/protocol, ignore it.
@@ -701,23 +610,30 @@ explore_fqdn(pai, hostname, servname, res)
 	if (get_portmatch(pai, servname) != 0)
 		return 0;
 
-	if (!_hostconf_init_done)
-		_hostconf_init();
-
-	for (i = 0; i < MAXHOSTCONF; i++) {
-		if (!_hostconf[i].byname)
-			continue;
-		error = (*_hostconf[i].byname)(pai, hostname, &result);
-		if (error != 0)
-			continue;
+	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_NODATA;
+		goto free;
+	case NS_SUCCESS:
+		error = 0;
 		for (cur = result; cur; cur = cur->ai_next) {
 			GET_PORT(cur, servname);
 			/* canonname should be filled already */
 		}
-		*res = result;
-		return 0;
+		break;
 	}
 
+	*res = result;
+
+	return 0;
+
 free:
 	if (result)
 		freeaddrinfo(result);
@@ -887,6 +803,7 @@ explore_numeric_scope(pai, hostname, servname, res)
 	afd = find_afd(pai->ai_family);
 	if (afd == NULL)
 		return 0;
+
 	if (!afd->a_scoped)
 		return explore_numeric(pai, hostname, servname, res);
 
@@ -1003,14 +920,13 @@ get_ai(pai, afd, addr)
 	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 *)(ai->ai_addr);
+	p = (char *)(void *)(ai->ai_addr);
 #ifdef FAITH
 	if (translate == 1)
-		memcpy(p + afd->a_off, &faith_prefix, afd->a_addrlen);
+		memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
 	else
 #endif
-	memcpy(p + afd->a_off, addr, afd->a_addrlen);
-
+	memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
 	return ai;
 }
 
@@ -1152,7 +1068,6 @@ addrconfig(pai)
 			else
 				_close(s);
 		}
-
 	}
 	if (af != AF_UNSPEC) {
 		if ((s = socket(af, SOCK_DGRAM, 0)) < 0)
@@ -1212,6 +1127,7 @@ ip6_str2scopeid(scope, sin6)
 static const char AskedForGot[] =
 	"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
 #endif
+static FILE *hostf = NULL;
 
 static struct addrinfo *
 getanswer(answer, anslen, qname, qtype, pai)
@@ -1415,17 +1331,21 @@ getanswer(answer, anslen, qname, qtype, pai)
 
 /*ARGSUSED*/
 static int
-_dns_getaddrinfo(pai, hostname, res)
-	const struct addrinfo *pai;
-	const char *hostname;
-	struct addrinfo **res;
+_dns_getaddrinfo(rv, cb_data, ap)
+	void	*rv;
+	void	*cb_data;
+	va_list	 ap;
 {
 	struct addrinfo *ai;
 	querybuf buf, buf2;
 	const char *name;
+	const struct addrinfo *pai;
 	struct addrinfo sentinel, *cur;
 	struct res_target q, q2;
 
+	name = va_arg(ap, char *);
+	pai = va_arg(ap, const struct addrinfo *);
+
 	memset(&q, 0, sizeof(q2));
 	memset(&q2, 0, sizeof(q2));
 	memset(&sentinel, 0, sizeof(sentinel));
@@ -1457,10 +1377,10 @@ _dns_getaddrinfo(pai, hostname, res)
 		q.anslen = sizeof(buf);
 		break;
 	default:
-		return EAI_FAIL;
+		return NS_UNAVAIL;
 	}
-	if (res_searchN(hostname, &q) < 0)
-		return EAI_NODATA;
+	if (res_searchN(name, &q) < 0)
+		return NS_NOTFOUND;
 	ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
 	if (ai) {
 		cur->ai_next = ai;
@@ -1475,19 +1395,36 @@ _dns_getaddrinfo(pai, hostname, res)
 	if (sentinel.ai_next == NULL)
 		switch (h_errno) {
 		case HOST_NOT_FOUND:
-			return EAI_NODATA;
+			return NS_NOTFOUND;
 		case TRY_AGAIN:
-			return EAI_AGAIN;
+			return NS_TRYAGAIN;
 		default:
-			return EAI_FAIL;
+			return NS_UNAVAIL;
 		}
-	*res = sentinel.ai_next;
-	return 0;
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	return NS_SUCCESS;
+}
+
+static void
+_sethtent()
+{
+	if (!hostf)
+		hostf = fopen(_PATH_HOSTS, "r" );
+	else
+		rewind(hostf);
+}
+
+static void
+_endhtent()
+{
+	if (hostf) {
+		(void) fclose(hostf);
+		hostf = NULL;
+	}
 }
 
 static struct addrinfo *
-_gethtent(hostf, name, pai)
-	FILE *hostf;
+_gethtent(name, pai)
 	const char *name;
 	const struct addrinfo *pai;
 {
@@ -1498,6 +1435,8 @@ _gethtent(hostf, name, pai)
 	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);
@@ -1557,102 +1496,181 @@ found:
 
 /*ARGSUSED*/
 static int
-_files_getaddrinfo(pai, hostname, res)
-	const struct addrinfo *pai;
-	const char *hostname;
-	struct addrinfo **res;
+_files_getaddrinfo(rv, cb_data, ap)
+	void	*rv;
+	void	*cb_data;
+	va_list	 ap;
 {
-	FILE *hostf;
+	const char *name;
+	const struct addrinfo *pai;
 	struct addrinfo sentinel, *cur;
 	struct addrinfo *p;
 
-	sentinel.ai_next = NULL;
+	name = va_arg(ap, char *);
+	pai = va_arg(ap, struct addrinfo *);
+
+	memset(&sentinel, 0, sizeof(sentinel));
 	cur = &sentinel;
 
-	if ((hostf = fopen(_PATH_HOSTS, "r")) == NULL)
-		return EAI_FAIL;
-	while ((p = _gethtent(hostf, hostname, pai)) != NULL) {
+	_sethtent();
+	while ((p = _gethtent(name, pai)) != NULL) {
 		cur->ai_next = p;
 		while (cur && cur->ai_next)
 			cur = cur->ai_next;
 	}
-	fclose(hostf);
+	_endhtent();
 
-	if (!sentinel.ai_next)
-		return EAI_NODATA;
-
-	*res = sentinel.ai_next;
-	return 0;
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	if (sentinel.ai_next == NULL)
+		return NS_NOTFOUND;
+	return NS_SUCCESS;
 }
 
 #ifdef YP
+static char *__ypdomain;
+
 /*ARGSUSED*/
-static int
-_nis_getaddrinfo(pai, hostname, res)
+static struct addrinfo *
+_yphostent(line, pai)
+	char *line;
 	const struct addrinfo *pai;
-	const char *hostname;
-	struct addrinfo **res;
 {
-	struct hostent *hp;
-	int h_error;
-	int af;
 	struct addrinfo sentinel, *cur;
-	int i;
-	const struct afd *afd;
+	struct addrinfo hints, *res, *res0;
 	int error;
+	char *p = line;
+	const char *addr, *canonname;
+	char *nextline;
+	char *cp;
 
-	sentinel.ai_next = NULL;
+	addr = canonname = NULL;
+
+	memset(&sentinel, 0, sizeof(sentinel));
 	cur = &sentinel;
 
-	af = (pai->ai_family == AF_UNSPEC) ? AF_INET : pai->ai_family;
-	if (af != AF_INET)
-		return (EAI_ADDRFAMILY);
+nextline:
+	/* terminate line */
+	cp = strchr(p, '\n');
+	if (cp) {
+		*cp++ = '\0';
+		nextline = cp;
+	} else
+		nextline = NULL;
 
-	if ((hp = _gethostbynisname(hostname, af)) == NULL) {
-		switch (errno) {
-		/* XXX: should be filled in */
-		default:
-			error = EAI_FAIL;
-			break;
-		}
-	} else if (hp->h_name == NULL ||
-		   hp->h_name[0] == 0 || hp->h_addr_list[0] == NULL) {
-		hp = NULL;
-		error = EAI_FAIL;
+	cp = strpbrk(p, " \t");
+	if (cp == NULL) {
+		if (canonname == NULL)
+			return (NULL);
+		else
+			goto done;
 	}
+	*cp++ = '\0';
 
-	if (hp == NULL)
-		return error;
+	addr = p;
 
-	for (i = 0; hp->h_addr_list[i] != NULL; i++) {
-		if (hp->h_addrtype != af)
+	while (cp && *cp) {
+		if (*cp == ' ' || *cp == '\t') {
+			cp++;
 			continue;
+		}
+		if (!canonname)
+			canonname = cp;
+		if ((cp = strpbrk(cp, " \t")) != NULL)
+			*cp++ = '\0';
+	}
 
-		afd = find_afd(hp->h_addrtype);
-		if (afd == NULL)
-			continue;
+	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;
 
-		GET_AI(cur->ai_next, afd, hp->h_addr_list[i]);
-		if ((pai->ai_flags & AI_CANONNAME) != 0) {
-			/*
-			 * RFC2553 says that ai_canonname will be set only for
-			 * the first element.  we do it for all the elements,
-			 * just for convenience.
-			 */
-			GET_CANONNAME(cur->ai_next, hp->h_name);
+			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;
 	}
 
-	*res = sentinel.ai_next;
-	return 0;
+	if (nextline) {
+		p = nextline;
+		goto nextline;
+	}
 
-free:
-	if (sentinel.ai_next)
-		freeaddrinfo(sentinel.ai_next);
-	return error;
+done:
+	return sentinel.ai_next;
+}
+
+/*ARGSUSED*/
+static int
+_yp_getaddrinfo(rv, cb_data, ap)
+	void	*rv;
+	void	*cb_data;
+	va_list	 ap;
+{
+	struct addrinfo sentinel, *cur;
+	struct addrinfo *ai = NULL;
+	static char *__ypcurrent;
+	int __ypcurrentlen, r;
+	const char *name;
+	const struct addrinfo *pai;
+
+	name = va_arg(ap, char *);
+	pai = va_arg(ap, const struct addrinfo *);
+
+	memset(&sentinel, 0, sizeof(sentinel));
+	cur = &sentinel;
+
+	if (!__ypdomain) {
+		if (_yp_check(&__ypdomain) == 0)
+			return NS_UNAVAIL;
+	}
+	if (__ypcurrent)
+		free(__ypcurrent);
+	__ypcurrent = NULL;
+
+	/* 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), &__ypcurrent, &__ypcurrentlen);
+		if (r == 0) {
+			struct addrinfo ai4;
+
+			ai4 = *pai;
+			ai4.ai_family = AF_INET;
+			ai = _yphostent(__ypcurrent, &ai4);
+			if (ai) {
+				cur->ai_next = ai;
+				while (cur && cur->ai_next)
+					cur = cur->ai_next;
+			}
+		}
+	}
+
+	/* ipnodes.byname can hold both IPv4/v6 */
+	r = yp_match(__ypdomain, "ipnodes.byname", name,
+		(int)strlen(name), &__ypcurrent, &__ypcurrentlen);
+	if (r == 0) {
+		ai = _yphostent(__ypcurrent, pai);
+		if (ai) {
+			cur->ai_next = ai;
+			while (cur && cur->ai_next)
+				cur = cur->ai_next;
+		}
+	}
+
+	if (sentinel.ai_next == NULL) {
+		h_errno = HOST_NOT_FOUND;
+		return NS_NOTFOUND;
+	}
+	*((struct addrinfo **)rv) = sentinel.ai_next;
+	return NS_SUCCESS;
 }
 #endif
 
diff --git a/lib/libc/net/gethostbydns.c b/lib/libc/net/gethostbydns.c
index a5a3e7b..4a56655 100644
--- a/lib/libc/net/gethostbydns.c
+++ b/lib/libc/net/gethostbydns.c
@@ -74,6 +74,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <syslog.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 
 #include "res_config.h"
 
@@ -474,19 +476,23 @@ __dns_getanswer(answer, anslen, qname, qtype)
 	return(gethostanswer((const querybuf *)answer, anslen, qname, qtype));
 }
 
-struct hostent *
-_gethostbydnsname(name, af)
+int
+_dns_gethostbyname(void *rval, void *cb_data, va_list ap)
+{
 	const char *name;
 	int af;
-{
 	querybuf buf;
 	register const char *cp;
 	char *bp;
 	int n, size, type, len;
 
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
+	*(struct hostent **)rval = NULL;
+
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		h_errno = NETDB_INTERNAL;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 
 	switch (af) {
@@ -501,7 +507,7 @@ _gethostbydnsname(name, af)
 	default:
 		h_errno = NETDB_INTERNAL;
 		errno = EAFNOSUPPORT;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 
 	host.h_addrtype = af;
@@ -531,7 +537,7 @@ _gethostbydnsname(name, af)
 				 */
 				if (inet_pton(af, name, host_addr) <= 0) {
 					h_errno = HOST_NOT_FOUND;
-					return (NULL);
+					return NS_NOTFOUND;
 				}
 				strncpy(hostbuf, name, MAXDNAME);
 				hostbuf[MAXDNAME] = '\0';
@@ -546,7 +552,8 @@ _gethostbydnsname(name, af)
 				if (_res.options & RES_USE_INET6)
 					_map_v4v6_hostent(&host, &bp, &len);
 				h_errno = NETDB_SUCCESS;
-				return (&host);
+				*(struct hostent **)rval = &host;
+				return NS_SUCCESS;
 			}
 			if (!isdigit((unsigned char)*cp) && *cp != '.')
 				break;
@@ -564,7 +571,7 @@ _gethostbydnsname(name, af)
 				 */
 				if (inet_pton(af, name, host_addr) <= 0) {
 					h_errno = HOST_NOT_FOUND;
-					return (NULL);
+					return NS_NOTFOUND;
 				}
 				strncpy(hostbuf, name, MAXDNAME);
 				hostbuf[MAXDNAME] = '\0';
@@ -577,7 +584,8 @@ _gethostbydnsname(name, af)
 				h_addr_ptrs[1] = NULL;
 				host.h_addr_list = h_addr_ptrs;
 				h_errno = NETDB_SUCCESS;
-				return (&host);
+				*(struct hostent **)rval = &host;
+				return NS_SUCCESS;
 			}
 			if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.')
 				break;
@@ -585,17 +593,18 @@ _gethostbydnsname(name, af)
 
 	if ((n = res_search(name, C_IN, type, buf.buf, sizeof(buf))) < 0) {
 		dprintf("res_search failed (%d)\n", n);
-		return (NULL);
+		return NS_UNAVAIL;
 	}
-	return (gethostanswer(&buf, n, name, type));
+	*(struct hostent **)rval = gethostanswer(&buf, n, name, type);
+	return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
-struct hostent *
-_gethostbydnsaddr(addr, len, af)
+int
+_dns_gethostbyaddr(void *rval, void *cb_data, va_list ap)
+{
 	const char *addr;	/* XXX should have been def'd as u_char! */
 	int len, af;
-{
-	const u_char *uaddr = (const u_char *)addr;
+	const u_char *uaddr;
 	static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
 	static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
 	int n, size;
@@ -608,10 +617,17 @@ _gethostbydnsaddr(addr, len, af)
 	u_long old_options;
 	char hname2[MAXDNAME+1];
 #endif /*SUNSECURITY*/
+
+	addr = va_arg(ap, const char *);
+	uaddr = (const u_char *)addr;
+	len = va_arg(ap, int);
+	af = va_arg(ap, int);
+	
+	*(struct hostent **)rval = NULL;
 	
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		h_errno = NETDB_INTERNAL;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	if (af == AF_INET6 && len == IN6ADDRSZ &&
 	    (!bcmp(uaddr, mapped, sizeof mapped) ||
@@ -632,12 +648,12 @@ _gethostbydnsaddr(addr, len, af)
 	default:
 		errno = EAFNOSUPPORT;
 		h_errno = NETDB_INTERNAL;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	if (size != len) {
 		errno = EINVAL;
 		h_errno = NETDB_INTERNAL;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	switch (af) {
 	case AF_INET:
@@ -662,14 +678,14 @@ _gethostbydnsaddr(addr, len, af)
 	n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf);
 	if (n < 0) {
 		dprintf("res_query failed (%d)\n", n);
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	if (n > sizeof buf.buf) {
 		dprintf("static buffer is too small (%d)\n", n);
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	if (!(hp = gethostanswer(&buf, n, qbuf, T_PTR)))
-		return (NULL);	/* h_errno was set by gethostanswer() */
+		return NS_NOTFOUND;   /* h_errno was set by gethostanswer() */
 #ifdef SUNSECURITY
 	if (af == AF_INET) {
 	    /*
@@ -687,7 +703,7 @@ _gethostbydnsaddr(addr, len, af)
 		       hname2, inet_ntoa(*((struct in_addr *)addr)));
 		_res.options = old_options;
 		h_errno = HOST_NOT_FOUND;
-		return (NULL);
+		return NS_NOTFOUND;
 	    }
 	    _res.options = old_options;
 	    for (haddr = rhp->h_addr_list; *haddr; haddr++)
@@ -698,7 +714,7 @@ _gethostbydnsaddr(addr, len, af)
 		       "gethostbyaddr: A record of %s != PTR record [%s]",
 		       hname2, inet_ntoa(*((struct in_addr *)addr)));
 		h_errno = HOST_NOT_FOUND;
-		return (NULL);
+		return NS_NOTFOUND;
 	    }
 	}
 #endif /*SUNSECURITY*/
@@ -713,7 +729,8 @@ _gethostbydnsaddr(addr, len, af)
 		hp->h_length = IN6ADDRSZ;
 	}
 	h_errno = NETDB_SUCCESS;
-	return (hp);
+	*(struct hostent **)rval = hp;
+	return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
 #ifdef RESOLVSORT
diff --git a/lib/libc/net/gethostbyht.c b/lib/libc/net/gethostbyht.c
index cd5f0f4..eeecd22 100644
--- a/lib/libc/net/gethostbyht.c
+++ b/lib/libc/net/gethostbyht.c
@@ -65,6 +65,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 #include <arpa/nameser.h>	/* XXX */
 #include <resolv.h>		/* XXX */
 
@@ -163,13 +165,16 @@ gethostent()
 	return (&host);
 }
 
-struct hostent *
-_gethostbyhtname(name, af)
+int
+_ht_gethostbyname(void *rval, void *cb_data, va_list ap) 
+{
 	const char *name;
 	int af;
-{
 	register struct hostent *p;
 	register char **cp;
+
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
 	
 	sethostent(0);
 	while ((p = gethostent()) != NULL) {
@@ -183,20 +188,28 @@ _gethostbyhtname(name, af)
 	}
 found:
 	endhostent();
-	return (p);
+	*(struct hostent **)rval = p;
+	
+	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
-struct hostent *
-_gethostbyhtaddr(addr, len, af)
+int 
+_ht_gethostbyaddr(void *rval, void *cb_data, va_list ap)
+{
 	const char *addr;
 	int len, af;
-{
 	register struct hostent *p;
 
+	addr = va_arg(ap, const char *);
+	len = va_arg(ap, int);
+	af = va_arg(ap, int);
+
 	sethostent(0);
 	while ((p = gethostent()) != NULL)
 		if (p->h_addrtype == af && !bcmp(p->h_addr, addr, len))
 			break;
 	endhostent();
-	return (p);
+
+	*(struct hostent **)rval = p;
+	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
diff --git a/lib/libc/net/gethostbyname.3 b/lib/libc/net/gethostbyname.3
index e513d74..0e2006e 100644
--- a/lib/libc/net/gethostbyname.3
+++ b/lib/libc/net/gethostbyname.3
@@ -78,10 +78,15 @@ following structure describing an internet host
 referenced by name or by address, respectively.
 This structure contains either the information obtained from the name server,
 .Xr named 8 ,
-or broken-out fields from a line in 
-.Pa /etc/hosts .
-If the local name server is not running these routines do a lookup in
-.Pa /etc/hosts .
+broken-out fields from a line in
+.Pa /etc/hosts ,
+or database entries supplied by the
+.Xr yp 4
+system.
+The order of the lookups is controlled by the
+.Sq hosts
+entry in
+.Xr nsswitch.conf 5 .
 .Bd -literal
 struct	hostent {
 	char	*h_name;	/* official name of host */
@@ -188,9 +193,9 @@ value of the
 .Fa err
 parameter.
 .Sh FILES
-.Bl -tag -width /etc/resolv.conf -compact
+.Bl -tag -width /etc/nsswitch.conf -compact
 .It Pa /etc/hosts
-.It Pa /etc/host.conf
+.It Pa /etc/nsswitch.conf
 .It Pa /etc/resolv.conf
 .El
 .Sh DIAGNOSTICS
diff --git a/lib/libc/net/gethostbynis.c b/lib/libc/net/gethostbynis.c
index 82e0b3d..518d512 100644
--- a/lib/libc/net/gethostbynis.c
+++ b/lib/libc/net/gethostbynis.c
@@ -39,6 +39,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 #ifdef YP
 #include <rpc/rpc.h>
 #include <rpcsvc/yp_prot.h>
@@ -52,7 +54,6 @@ static char rcsid[] = "$FreeBSD$";
 static char *host_aliases[MAXALIASES];
 static char hostaddr[MAXADDRS];
 static char *host_addrs[2];
-#endif /* YP */
 
 static struct hostent *
 _gethostbynis(name, map, af)
@@ -60,7 +61,6 @@ _gethostbynis(name, map, af)
 	char *map;
 	int af;
 {
-#ifdef YP
 	register char *cp, **q;
 	char *result;
 	int resultlen,size;
@@ -122,24 +122,64 @@ _gethostbynis(name, map, af)
 	}
 	*q = NULL;
 	return (&h);
-#else
-	return (NULL);
-#endif /* YP */
 }
+#endif /* YP */
 
+/* XXX _gethostbynisname/_gethostbynisaddr only used by getaddrinfo */
 struct hostent *
-_gethostbynisname(name, af)
-	const char *name;
-	int af;
+_gethostbynisname(const char *name, int af)
 {
+#ifdef YP
 	return _gethostbynis(name, "hosts.byname", af);
+#else
+	return NULL;
+#endif
 }
 
 struct hostent *
-_gethostbynisaddr(addr, len, af)
+_gethostbynisaddr(const char *addr, int len, int af)
+{
+#ifdef YP
+	return _gethostbynis(inet_ntoa(*(struct in_addr *)addr), 
+			     "hosts.byaddr", af);
+#else
+	return NULL;
+#endif
+}
+
+
+int
+_nis_gethostbyname(void *rval, void *cb_data, va_list ap)
+{
+#ifdef YP
+	const char *name;
+	int af;
+
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
+
+	*(struct hostent **)rval = _gethostbynis(name, "hosts.byname", af);
+	return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
+#else
+	return NS_UNAVAIL;
+#endif
+}
+
+int
+_nis_gethostbyaddr(void *rval, void *cb_data, va_list ap)
+{
+#ifdef YP
 	const char *addr;
 	int len;
 	int af;
-{
-	return _gethostbynis(inet_ntoa(*(struct in_addr *)addr),"hosts.byaddr", af);
+
+	addr = va_arg(ap, const char *);
+	len = va_arg(ap, int);
+	af = va_arg(ap, int);
+	
+	*(struct hostent **)rval =_gethostbynis(inet_ntoa(*(struct in_addr *)addr),"hosts.byaddr", af);
+	return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
+#else
+	return NS_UNAVAIL;
+#endif
 }
diff --git a/lib/libc/net/gethostnamadr.c b/lib/libc/net/gethostnamadr.c
index 010e4db..fcfc979 100644
--- a/lib/libc/net/gethostnamadr.c
+++ b/lib/libc/net/gethostnamadr.c
@@ -37,87 +37,25 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 #include <arpa/nameser.h>		/* XXX hack for _res */
 #include <resolv.h>			/* XXX hack for _res */
 
-#define _PATH_HOSTCONF	"/etc/host.conf"
-
-enum service_type {
-  SERVICE_NONE = 0,
-  SERVICE_BIND,
-  SERVICE_HOSTS,
-  SERVICE_NIS };
-#define SERVICE_MAX	SERVICE_NIS
-
-static struct {
-  const char *name;
-  enum service_type type;
-} service_names[] = {
-  { "hosts", SERVICE_HOSTS },
-  { "/etc/hosts", SERVICE_HOSTS },
-  { "hosttable", SERVICE_HOSTS },
-  { "htable", SERVICE_HOSTS },
-  { "bind", SERVICE_BIND },
-  { "dns", SERVICE_BIND },
-  { "domain", SERVICE_BIND },
-  { "yp", SERVICE_NIS },
-  { "yellowpages", SERVICE_NIS },
-  { "nis", SERVICE_NIS },
-  { 0, SERVICE_NONE }
+extern int _ht_gethostbyname(void *, void *, va_list);
+extern int _dns_gethostbyname(void *, void *, va_list);
+extern int _nis_gethostbyname(void *, void *, va_list);
+extern int _ht_gethostbyaddr(void *, void *, va_list);
+extern int _dns_gethostbyaddr(void *, void *, va_list);
+extern int _nis_gethostbyaddr(void *, void *, va_list);
+
+/* Host lookup order if nsswitch.conf is broken or nonexistant */
+static const ns_src default_src[] = { 
+	{ NSSRC_FILES, NS_SUCCESS },
+	{ NSSRC_DNS, NS_SUCCESS },
+	{ 0 }
 };
 
-static enum service_type service_order[SERVICE_MAX + 1];
-static int service_done = 0;
-
-static enum service_type
-get_service_name(const char *name) {
-	int i;
-	for(i = 0; service_names[i].type != SERVICE_NONE; i++) {
-		if(!strcasecmp(name, service_names[i].name)) {
-			return service_names[i].type;
-		}
-	}
-	return SERVICE_NONE;
-}
-
-static void
-init_services()
-{
-	char *cp, *p, buf[BUFSIZ];
-	register int cc = 0;
-	FILE *fd;
-
-	if ((fd = (FILE *)fopen(_PATH_HOSTCONF, "r")) == NULL) {
-				/* make some assumptions */
-		service_order[0] = SERVICE_BIND;
-		service_order[1] = SERVICE_HOSTS;
-		service_order[2] = SERVICE_NONE;
-	} else {
-		while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) {
-			if(buf[0] == '#')
-				continue;
-
-			p = buf;
-			while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
-				;
-			if (cp == NULL)
-				continue;
-			do {
-				if (isalpha((unsigned char)cp[0])) {
-					service_order[cc] = get_service_name(cp);
-					if(service_order[cc] != SERVICE_NONE)
-						cc++;
-				}
-				while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
-					;
-			} while(cp != NULL && cc < SERVICE_MAX);
-		}
-		service_order[cc] = SERVICE_NONE;
-		fclose(fd);
-	}
-	service_done = 1;
-}
-
 struct hostent *
 gethostbyname(const char *name)
 {
@@ -135,56 +73,44 @@ struct hostent *
 gethostbyname2(const char *name, int type)
 {
 	struct hostent *hp = 0;
-	int nserv = 0;
-
-	if (!service_done)
-		init_services();
-
-	while (!hp) {
-		switch (service_order[nserv]) {
-		      case SERVICE_NONE:
-			return NULL;
-		      case SERVICE_HOSTS:
-			hp = _gethostbyhtname(name, type);
-			break;
-		      case SERVICE_BIND:
-			hp = _gethostbydnsname(name, type);
-			break;
-		      case SERVICE_NIS:
-			hp = _gethostbynisname(name, type);
-			break;
-		}
-		nserv++;
-	}
-	return hp;
+	int rval;
+
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_ht_gethostbyname, NULL)
+		{ NSSRC_DNS, _dns_gethostbyname, NULL },
+		NS_NIS_CB(_nis_gethostbyname, NULL) /* force -DHESIOD */
+		{ 0 }
+	};       
+	
+	rval = nsdispatch((void *)&hp, dtab, NSDB_HOSTS, "gethostbyname",
+			  default_src, name, type);
+
+	if (rval != NS_SUCCESS)
+		return NULL;
+	else
+		return hp;
 }
 
 struct hostent *
 gethostbyaddr(const char *addr, int len, int type)
 {
 	struct hostent *hp = 0;
-	int nserv = 0;
-
-	if (!service_done)
-		init_services();
-
-	while (!hp) {
-		switch (service_order[nserv]) {
-		      case SERVICE_NONE:
-			return 0;
-		      case SERVICE_HOSTS:
-			hp = _gethostbyhtaddr(addr, len, type);
-			break;
-		      case SERVICE_BIND:
-			hp = _gethostbydnsaddr(addr, len, type);
-			break;
-		      case SERVICE_NIS:
-			hp = _gethostbynisaddr(addr, len, type);
-			break;
-		}
-		nserv++;
-	}
-	return hp;
+	int rval;
+
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_ht_gethostbyaddr, NULL)
+		{ NSSRC_DNS, _dns_gethostbyaddr, NULL },
+		NS_NIS_CB(_nis_gethostbyaddr, NULL) /* force -DHESIOD */
+		{ 0 }
+	};       
+
+	rval = nsdispatch((void *)&hp, dtab, NSDB_HOSTS, "gethostbyaddr",
+			  default_src, addr, len, type);
+
+	if (rval != NS_SUCCESS)
+		return NULL;
+	else
+		return hp;
 }
 
 #ifdef _THREAD_SAFE
diff --git a/lib/libc/net/getipnodebyname.3 b/lib/libc/net/getipnodebyname.3
index 618f5a3..5eec582 100644
--- a/lib/libc/net/getipnodebyname.3
+++ b/lib/libc/net/getipnodebyname.3
@@ -405,9 +405,9 @@ or
 .Fn getipnodebyaddr .
 .\"
 .Sh FILES
-.Bl -tag -width /etc/resolv.conf -compact
+.Bl -tag -width /etc/nsswitch.conf -compact
 .It Pa /etc/hosts
-.It Pa /etc/host.conf
+.It Pa /etc/nsswitch.conf
 .It Pa /etc/resolv.conf
 .El
 .\"
@@ -429,6 +429,7 @@ The meanings of each error code are described in
 .Xr gethostbyname 3 ,
 .Xr gethostbyaddr 3 ,
 .Xr hosts 5 ,
+.Xr nsswitch.conf 5 ,
 .Xr services 5 ,
 .Xr hostname 7 ,
 .Xr named 8
diff --git a/lib/libc/net/getnameinfo.3 b/lib/libc/net/getnameinfo.3
index 113563f..0289b9f 100644
--- a/lib/libc/net/getnameinfo.3
+++ b/lib/libc/net/getnameinfo.3
@@ -226,9 +226,9 @@ printf("host=%s\\n", hbuf);
 .Ed
 .\"
 .Sh FILES
-.Bl -tag -width /etc/resolv.conf -compact
+.Bl -tag -width /etc/nsswitch.conf -compact
 .It Pa /etc/hosts
-.It Pa /etc/host.conf
+.It Pa /etc/nsswitch.conf
 .It Pa /etc/resolv.conf
 .El
 .\"
diff --git a/lib/libc/net/getnetbydns.c b/lib/libc/net/getnetbydns.c
index 65d9d2d..5827103 100644
--- a/lib/libc/net/getnetbydns.c
+++ b/lib/libc/net/getnetbydns.c
@@ -77,6 +77,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <string.h>
 #include <unistd.h>
 #include <syslog.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 
 #include "res_config.h"
 
@@ -218,11 +220,11 @@ static	char *net_aliases[MAXALIASES], netbuf[PACKETSZ];
 	return (NULL);
 }
 
-struct netent *
-_getnetbydnsaddr(net, net_type)
-	register unsigned long net;
-	register int net_type;
+int
+_dns_getnetbyaddr(void *rval, void *cb_data, va_list ap)
 {
+	unsigned long net;
+	int net_type;
 	unsigned int netbr[4];
 	int nn, anslen;
 	querybuf buf;
@@ -230,8 +232,13 @@ _getnetbydnsaddr(net, net_type)
 	unsigned long net2;
 	struct netent *net_entry;
 
+	net = va_arg(ap, unsigned long);
+	net_type = va_arg(ap, int);
+
+	*(struct netent **)rval = NULL;
+
 	if (net_type != AF_INET)
-		return (NULL);
+		return NS_UNAVAIL;
 
 	for (nn = 4, net2 = net; net2; net2 >>= 8)
 		netbr[--nn] = net2 & 0xff;
@@ -257,7 +264,7 @@ _getnetbydnsaddr(net, net_type)
 		if (_res.options & RES_DEBUG)
 			printf("res_query failed\n");
 #endif
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	net_entry = getnetanswer(&buf, anslen, BYADDR);
 	if (net_entry) {
@@ -267,22 +274,27 @@ _getnetbydnsaddr(net, net_type)
 		while ((u_net & 0xff) == 0 && u_net != 0)
 			u_net >>= 8;
 		net_entry->n_net = u_net;
-		return (net_entry);
+		*(struct netent **)rval = net_entry;
+		return NS_SUCCESS;
 	}
-	return (NULL);
+	return NS_NOTFOUND;
 }
 
-struct netent *
-_getnetbydnsname(net)
-	register const char *net;
+int
+_dns_getnetbyname(void *rval, void *cb_data, va_list ap)
 {
+	const char *net;
 	int anslen;
 	querybuf buf;
 	char qbuf[MAXDNAME];
 
+	net = va_arg(ap, const char *);
+
+	*(struct netent**)rval = NULL;
+
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		h_errno = NETDB_INTERNAL;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 	strncpy(qbuf, net, sizeof(qbuf) - 1);
 	qbuf[sizeof(qbuf) - 1] = '\0';
@@ -292,9 +304,10 @@ _getnetbydnsname(net)
 		if (_res.options & RES_DEBUG)
 			printf("res_query failed\n");
 #endif
-		return (NULL);
+		return NS_UNAVAIL;
 	}
-	return getnetanswer(&buf, anslen, BYNAME);
+	*(struct netent**)rval = getnetanswer(&buf, anslen, BYNAME);
+	return (*(struct netent**)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
 void
diff --git a/lib/libc/net/getnetbyht.c b/lib/libc/net/getnetbyht.c
index ab164b1..b5f73be 100644
--- a/lib/libc/net/getnetbyht.c
+++ b/lib/libc/net/getnetbyht.c
@@ -55,6 +55,8 @@ static chat rcsid[] = "$FreeBSD$";
 #include <netdb.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 
 #define	MAXALIASES	35
 
@@ -135,13 +137,15 @@ again:
 	return (&net);
 }
 
-struct netent *
-_getnetbyhtname(name)
-	register const char *name;
+int
+_ht_getnetbyname(void *rval, void *cb_data, va_list ap)
 {
+	const char *name;
 	register struct netent *p;
 	register char **cp;
 
+	name = va_arg(ap, const char *);
+
 	setnetent(_net_stayopen);
 	while ( (p = getnetent()) ) {
 		if (strcasecmp(p->n_name, name) == 0)
@@ -153,21 +157,26 @@ _getnetbyhtname(name)
 found:
 	if (!_net_stayopen)
 		endnetent();
-	return (p);
+	*(struct netent **)rval = p;
+	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
-struct netent *
-_getnetbyhtaddr(net, type)
-	register unsigned long net;
-	register int type;
+int
+_ht_getnetbyaddr(void *rval, void *cb_data, va_list ap)
 {
+	unsigned long net;
+	int type;
 	register struct netent *p;
 
+	net = va_arg(ap, unsigned long);
+	type = va_arg(ap, int);
+
 	setnetent(_net_stayopen);
 	while ( (p = getnetent()) )
 		if (p->n_addrtype == type && p->n_net == net)
 			break;
 	if (!_net_stayopen)
 		endnetent();
-	return (p);
+	*(struct netent **)rval = p;
+	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
diff --git a/lib/libc/net/getnetbynis.c b/lib/libc/net/getnetbynis.c
index 0ab7073..d226b01 100644
--- a/lib/libc/net/getnetbynis.c
+++ b/lib/libc/net/getnetbynis.c
@@ -38,6 +38,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 #include <arpa/nameser.h>
 #ifdef YP
 #include <rpc/rpc.h>
@@ -50,15 +52,10 @@ static char rcsid[] = "$FreeBSD$";
 
 #ifdef YP
 static char *host_aliases[MAXALIASES];
-#endif /* YP */
 
 static struct netent *
-_getnetbynis(name, map, af)
-	const char *name;
-	char *map;
-	int af;
+_getnetbynis(const char *name, char *map, int af)
 {
-#ifdef YP
 	register char *cp, **q;
 	static char *result;
 	int resultlen;
@@ -117,32 +114,45 @@ _getnetbynis(name, map, af)
 	}
 	*q = NULL;
 	return (&h);
-#else
-	return (NULL);
-#endif
 }
+#endif /* YP */
 
-struct netent *
-_getnetbynisname(name)
-	const char *name;
+int
+_nis_getnetbyname(void *rval, void *cb_data, va_list ap)
 {
-	return _getnetbynis(name, "networks.byname", AF_INET);
+#ifdef YP
+	const char *name;
+
+	name = va_arg(ap, const char *);
+	
+	*(struct netent **)rval = _getnetbynis(name, "networks.byname", AF_INET);
+	return (*(struct netent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
+#else
+	return NS_UNAVAIL;
+#endif
+
 }
 
-struct netent *
-_getnetbynisaddr(addr, af)
+int 
+_nis_getnetbyaddr(void *rval, void *cb_data, va_list ap)
+{
+#ifdef YP
 	unsigned long addr;
 	int af;
-{
 	char *str, *cp;
 	unsigned long net2;
 	int nn;
 	unsigned int netbr[4];
 	char buf[MAXDNAME];
 
+	addr = va_arg(ap, unsigned long);
+	af = va_arg(ap, int);
+
+	*(struct netent **)rval = NULL;
+
 	if (af != AF_INET) {
 		errno = EAFNOSUPPORT;
-		return (NULL);
+		return NS_UNAVAIL;
 	}
 
         for (nn = 4, net2 = addr; net2; net2 >>= 8) {
@@ -173,5 +183,9 @@ _getnetbynisaddr(addr, af)
 		cp = str + (strlen(str) - 2);
 	}
 
-	return _getnetbynis(str, "networks.byaddr", af);
+	*(struct netent **)rval = _getnetbynis(str, "networks.byaddr", af);
+	return (*(struct netent**)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
+#else
+	return NS_UNAVAIL;
+#endif /* YP */
 }
diff --git a/lib/libc/net/getnetent.3 b/lib/libc/net/getnetent.3
index 086f4c3..de3e9df 100644
--- a/lib/libc/net/getnetent.3
+++ b/lib/libc/net/getnetent.3
@@ -64,10 +64,18 @@ and
 .Fn getnetbyaddr
 functions
 each return a pointer to an object with the
-following structure
-containing the broken-out
-fields of a line in the network data base,
-.Pa /etc/networks .
+following structure describing an internet network.
+This structure contains either the information obtained
+from the nameserver, 
+.Xr named 8 ,
+broken-out fields of a line in the network data base
+.Pa /etc/networks ,
+or entries supplied by the
+.Xr yp 4 
+system.  The order of the lookups is controlled by the
+`networks' entry in 
+.Xr nsswitch.conf 5 .
+.Pp
 .Bd -literal -offset indent
 struct	netent {
 	char		*n_name;	/* official name of net */
@@ -129,8 +137,10 @@ must be
 .Dv AF_INET .
 Network numbers are supplied in host order.
 .Sh FILES
-.Bl -tag -width /etc/networks -compact
+.Bl -tag -width /etc/nsswitch.conf -compact
 .It Pa /etc/networks
+.It Pa /etc/nsswitch.conf
+.It Pa /etc/resolv.conf
 .El
 .Sh DIAGNOSTICS
 Null pointer
diff --git a/lib/libc/net/getnetnamadr.c b/lib/libc/net/getnetnamadr.c
index cb5871b..6d9dbfa 100644
--- a/lib/libc/net/getnetnamadr.c
+++ b/lib/libc/net/getnetnamadr.c
@@ -36,142 +36,66 @@ static char rcsid[] = "$FreeBSD$";
 #include <ctype.h>
 #include <errno.h>
 #include <string.h>
-
-#ifndef _PATH_NETCONF
-#define _PATH_NETCONF	"/etc/host.conf"
-#endif
-
-enum service_type {
-  SERVICE_NONE = 0,
-  SERVICE_BIND,
-  SERVICE_TABLE,
-  SERVICE_NIS };
-#define SERVICE_MAX	SERVICE_NIS
-
-static struct {
-  const char *name;
-  enum service_type type;
-} service_names[] = {
-  { "hosts", SERVICE_TABLE },
-  { "/etc/hosts", SERVICE_TABLE },
-  { "hosttable", SERVICE_TABLE },
-  { "htable", SERVICE_TABLE },
-  { "bind", SERVICE_BIND },
-  { "dns", SERVICE_BIND },
-  { "domain", SERVICE_BIND },
-  { "yp", SERVICE_NIS },
-  { "yellowpages", SERVICE_NIS },
-  { "nis", SERVICE_NIS },
-  { 0, SERVICE_NONE }
+#include <stdarg.h>
+#include <nsswitch.h>
+
+extern int _ht_getnetbyname(void *, void *, va_list);
+extern int _dns_getnetbyname(void *, void *, va_list);
+extern int _nis_getnetbyname(void *, void *, va_list);
+extern int _ht_getnetbyaddr(void *, void *, va_list);
+extern int _dns_getnetbyaddr(void *, void *, va_list);
+extern int _nis_getnetbyaddr(void *, void *, va_list);
+
+/* Network lookup order if nsswitch.conf is broken or nonexistant */
+static const ns_src default_src[] = { 
+	{ NSSRC_FILES, NS_SUCCESS },
+	{ NSSRC_DNS, NS_SUCCESS },
+	{ 0 }
 };
 
-static enum service_type service_order[SERVICE_MAX + 1];
-static int service_done = 0;
-
-static enum service_type
-get_service_name(const char *name) {
-	int i;
-	for(i = 0; service_names[i].type != SERVICE_NONE; i++) {
-		if(!strcasecmp(name, service_names[i].name)) {
-			return service_names[i].type;
-		}
-	}
-	return SERVICE_NONE;
-}
-
-static void
-init_services()
-{
-	char *cp, *p, buf[BUFSIZ];
-	register int cc = 0;
-	FILE *fd;
-
-	if ((fd = (FILE *)fopen(_PATH_NETCONF, "r")) == NULL) {
-				/* make some assumptions */
-		service_order[0] = SERVICE_TABLE;
-		service_order[1] = SERVICE_NONE;
-	} else {
-		while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) {
-			if(buf[0] == '#')
-				continue;
-
-			p = buf;
-			while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
-				;
-			if (cp == NULL)
-				continue;
-			do {
-				if (isalpha((unsigned char)cp[0])) {
-					service_order[cc] = get_service_name(cp);
-					if(service_order[cc] != SERVICE_NONE)
-						cc++;
-				}
-				while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
-					;
-			} while(cp != NULL && cc < SERVICE_MAX);
-		}
-		service_order[cc] = SERVICE_NONE;
-		fclose(fd);
-	}
-	service_done = 1;
-}
-
 struct netent *
 getnetbyname(const char *name)
 {
 	struct netent *hp = 0;
-	int nserv = 0;
-
-	if (!service_done)
-		init_services();
-
-	while (!hp) {
-		switch (service_order[nserv]) {
-		      case SERVICE_NONE:
-			return NULL;
-		      case SERVICE_TABLE:
-			hp = _getnetbyhtname(name);
-			break;
-		      case SERVICE_BIND:
-			hp = _getnetbydnsname(name);
-			break;
-		      case SERVICE_NIS:
-			hp = _getnetbynisname(name);
-			break;
-		}
-		nserv++;
-	}
-	return hp;
+	int rval;
+
+
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_ht_getnetbyname, NULL)
+		{ NSSRC_DNS, _dns_getnetbyname, NULL },
+		NS_NIS_CB(_nis_getnetbyname, NULL) /* force -DHESIOD */
+		{ 0 }
+	};       
+	
+	rval = nsdispatch((void *)&hp, dtab, NSDB_NETWORKS, "getnetbyname",
+			  default_src, name);
+
+	if (rval != NS_SUCCESS)
+		return NULL;
+	else
+		return hp;
 }
 
 struct netent *
-getnetbyaddr(addr, af)
-	u_long addr;
-	int af;
+getnetbyaddr(u_long addr, int af)
 {
 	struct netent *hp = 0;
-	int nserv = 0;
-
-	if (!service_done)
-		init_services();
-
-	while (!hp) {
-		switch (service_order[nserv]) {
-		      case SERVICE_NONE:
-			return 0;
-		      case SERVICE_TABLE:
-			hp = _getnetbyhtaddr(addr, af);
-			break;
-		      case SERVICE_BIND:
-			hp = _getnetbydnsaddr(addr, af);
-			break;
-		      case SERVICE_NIS:
-			hp = _getnetbynisaddr(addr, af);
-			break;
-		}
-		nserv++;
-	}
-	return hp;
+	int rval;
+
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_ht_getnetbyaddr, NULL)
+		{ NSSRC_DNS, _dns_getnetbyaddr, NULL },
+		NS_NIS_CB(_nis_getnetbyaddr, NULL) /* force -DHESIOD */
+		{ 0 }
+	};       
+
+	rval = nsdispatch((void *)&hp, dtab, NSDB_HOSTS, "getnetbyaddr",
+			  default_src, addr, af);
+
+	if (rval != NS_SUCCESS)
+		return NULL;
+	else
+		return hp;
 }
 
 void
diff --git a/lib/libc/net/hesiod.3 b/lib/libc/net/hesiod.3
new file mode 100644
index 0000000..49e7d67
--- /dev/null
+++ b/lib/libc/net/hesiod.3
@@ -0,0 +1,136 @@
+.\"	$NetBSD: hesiod.3,v 1.1 1999/01/25 03:43:04 lukem Exp $
+.\"	$FreeBSD$
+.\"
+.\" from: #Id: hesiod.3,v 1.9.2.1 1997/01/03 21:02:23 ghudson Exp #
+.\"
+.\" Copyright 1988, 1996 by the Massachusetts Institute of Technology.
+.\"
+.\" Permission to use, copy, modify, and distribute this
+.\" software and its documentation for any purpose and without
+.\" fee is hereby granted, provided that the above copyright
+.\" notice appear in all copies and that both that copyright
+.\" notice and this permission notice appear in supporting
+.\" documentation, and that the name of M.I.T. not be used in
+.\" advertising or publicity pertaining to distribution of the
+.\" software without specific, written prior permission.
+.\" M.I.T. makes no representations about the suitability of
+.\" this software for any purpose.  It is provided "as is"
+.\" without express or implied warranty.
+.\"
+.TH HESIOD 3 "30 November 1996"
+.SH NAME
+hesiod, hesiod_init, hesiod_resolve, hesiod_free_list, hesiod_to_bind, hesiod_end \- Hesiod name server interface library
+.SH SYNOPSIS
+.nf
+.B #include <hesiod.h>
+.PP
+.B int hesiod_init(void **\fIcontext\fP)
+.B char **hesiod_resolve(void *\fIcontext\fP, const char *\fIname\fP,
+.B 	const char *\fItype\fP)
+.B void hesiod_free_list(void *\fIcontext\fP, char **\fIlist\fP);
+.B char *hesiod_to_bind(void *\fIcontext\fP, const char *\fIname\fP,
+.B 	const char *\fItype\fP)
+.B void hesiod_end(void *\fIcontext\fP)
+.PP
+.B cc file.c -lhesiod
+.fi
+.SH DESCRIPTION
+This family of functions allows you to perform lookups of Hesiod
+information, which is stored as text records in the Domain Name
+Service.  To perform lookups, you must first initialize a
+.IR context ,
+an opaque object which stores information used internally by the
+library between calls.
+.I hesiod_init
+initializes a context, storing a pointer to the context in the
+location pointed to by the
+.I context
+argument.
+.I hesiod_end
+frees the resources used by a context.
+.PP
+.I hesiod_resolve
+is the primary interface to the library.  If successful, it returns a
+list of one or more strings giving the records matching
+.I name
+and
+.IR type .
+The last element of the list is followed by a NULL pointer.  It is the
+caller's responsibility to call
+.I hesiod_free_list
+to free the resources used by the returned list.
+.PP
+.I hesiod_to_bind
+converts
+.I name
+and
+.I type
+into the DNS name used by
+.IR hesiod_resolve .
+It is the caller's responsibility to free the returned string using
+.IR free .
+.SH RETURN VALUES
+If successful,
+.I hesiod_init
+returns 0; otherwise it returns \-1 and sets
+.I errno
+to indicate the error.  On failure,
+.I hesiod_resolve
+and
+.I hesiod_to_bind
+return NULL and set the global variable
+.I errno
+to indicate the error.
+.SH ENVIRONMENT
+If the environment variable
+.B HES_DOMAIN
+is set, it will override the domain in the Hesiod configuration file.
+If the environment variable
+.B HESIOD_CONFIG
+is set, it specifies the location of the Hesiod configuration file.
+.SH SEE ALSO
+`Hesiod - Project Athena Technical Plan -- Name Service', named(8),
+hesiod.conf(5)
+.SH ERRORS
+Hesiod calls may fail because of:
+.IP ENOMEM
+Insufficient memory was available to carry out the requested
+operation.
+.IP ENOEXEC
+.I hesiod_init
+failed because the Hesiod configuration file was invalid.
+.IP ECONNREFUSED
+.I hesiod_resolve
+failed because no name server could be contacted to answer the query.
+.IP EMSGSIZE
+.I hesiod_resolve
+or
+.I hesiod_to_bind
+failed because the query or response was too big to fit into the
+packet buffers.
+.IP ENOENT
+.I hesiod_resolve
+failed because the name server had no text records matching
+.I name
+and
+.IR type ,
+or
+.I hesiod_to_bind
+failed because the
+.I name
+argument had a domain extension which could not be resolved with type
+``rhs-extension'' in the local Hesiod domain.
+.SH AUTHOR
+Steve Dyer, IBM/Project Athena
+.br
+Greg Hudson, MIT Team Athena
+.br
+Copyright 1987, 1988, 1995, 1996 by the Massachusetts Institute of Technology.
+.SH BUGS
+The strings corresponding to the
+.I errno
+values set by the Hesiod functions are not particularly indicative of
+what went wrong, especially for
+.I ENOEXEC
+and
+.IR ENOENT .
diff --git a/lib/libc/net/hesiod.c b/lib/libc/net/hesiod.c
new file mode 100644
index 0000000..f36757b
--- /dev/null
+++ b/lib/libc/net/hesiod.c
@@ -0,0 +1,572 @@
+/*	$NetBSD: hesiod.c,v 1.9 1999/02/11 06:16:38 simonb Exp $	*/
+
+/* Copyright (c) 1996 by Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+/* Copyright 1996 by the Massachusetts Institute of Technology.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ */
+
+/* This file is part of the hesiod library.  It implements the core
+ * portion of the hesiod resolver.
+ *
+ * This file is loosely based on an interim version of hesiod.c from
+ * the BIND IRS library, which was in turn based on an earlier version
+ * of this file.  Extensive changes have been made on each step of the
+ * path.
+ *
+ * This implementation is not truly thread-safe at the moment because
+ * it uses res_send() and accesses _res.
+ */
+
+#include <sys/cdefs.h>
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *orig_rcsid = "$NetBSD: hesiod.c,v 1.9 1999/02/11 06:16:38 simonb Exp $";
+static char *rcsid = "$FreeBSD$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <hesiod.h>
+#include <resolv.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct hesiod_p {
+	char	*lhs;			/* normally ".ns" */
+	char	*rhs;			/* AKA the default hesiod domain */
+	int	 classes[2];		/* The class search order. */
+};
+
+#define	MAX_HESRESP	1024
+
+static int	  read_config_file __P((struct hesiod_p *, const char *));
+static char	**get_txt_records __P((int, const char *));
+static int	  init_context __P((void));
+static void	  translate_errors __P((void));
+
+
+/*
+ * hesiod_init --
+ *	initialize a hesiod_p.
+ */
+int 
+hesiod_init(context)
+	void	**context;
+{
+	struct hesiod_p	*ctx;
+	const char	*p, *configname;
+
+	ctx = malloc(sizeof(struct hesiod_p));
+	if (ctx) {
+		*context = ctx;
+		configname = getenv("HESIOD_CONFIG");
+		if (!configname)
+			configname = _PATH_HESIOD_CONF;
+		if (read_config_file(ctx, configname) >= 0) {
+			/*
+			 * The default rhs can be overridden by an
+			 * environment variable.
+			 */
+			p = getenv("HES_DOMAIN");
+			if (p) {
+				if (ctx->rhs)
+					free(ctx->rhs);
+				ctx->rhs = malloc(strlen(p) + 2);
+				if (ctx->rhs) {
+					*ctx->rhs = '.';
+					strcpy(ctx->rhs + 1,
+					    (*p == '.') ? p + 1 : p);
+					return 0;
+				} else
+					errno = ENOMEM;
+			} else
+				return 0;
+		}
+	} else
+		errno = ENOMEM;
+
+	if (ctx->lhs)
+		free(ctx->lhs);
+	if (ctx->rhs)
+		free(ctx->rhs);
+	if (ctx)
+		free(ctx);
+	return -1;
+}
+
+/*
+ * hesiod_end --
+ *	Deallocates the hesiod_p.
+ */
+void 
+hesiod_end(context)
+	void	*context;
+{
+	struct hesiod_p *ctx = (struct hesiod_p *) context;
+
+	free(ctx->rhs);
+	if (ctx->lhs)
+		free(ctx->lhs);
+	free(ctx);
+}
+
+/*
+ * hesiod_to_bind --
+ * 	takes a hesiod (name, type) and returns a DNS
+ *	name which is to be resolved.
+ */
+char *
+hesiod_to_bind(void *context, const char *name, const char *type)
+{
+	struct hesiod_p *ctx = (struct hesiod_p *) context;
+	char		 bindname[MAXDNAME], *p, *ret, **rhs_list = NULL;
+	const char	*rhs;
+	int		 len;
+
+	strcpy(bindname, name);
+
+		/*
+		 * Find the right right hand side to use, possibly
+		 * truncating bindname.
+		 */
+	p = strchr(bindname, '@');
+	if (p) {
+		*p++ = 0;
+		if (strchr(p, '.'))
+			rhs = name + (p - bindname);
+		else {
+			rhs_list = hesiod_resolve(context, p, "rhs-extension");
+			if (rhs_list)
+				rhs = *rhs_list;
+			else {
+				errno = ENOENT;
+				return NULL;
+			}
+		}
+	} else
+		rhs = ctx->rhs;
+
+		/* See if we have enough room. */
+	len = strlen(bindname) + 1 + strlen(type);
+	if (ctx->lhs)
+		len += strlen(ctx->lhs) + ((ctx->lhs[0] != '.') ? 1 : 0);
+	len += strlen(rhs) + ((rhs[0] != '.') ? 1 : 0);
+	if (len > sizeof(bindname) - 1) {
+		if (rhs_list)
+			hesiod_free_list(context, rhs_list);
+		errno = EMSGSIZE;
+		return NULL;
+	}
+		/* Put together the rest of the domain. */
+	strcat(bindname, ".");
+	strcat(bindname, type);
+		/* Only append lhs if it isn't empty. */
+	if (ctx->lhs && ctx->lhs[0] != '\0' ) {
+		if (ctx->lhs[0] != '.')
+			strcat(bindname, ".");
+		strcat(bindname, ctx->lhs);
+	}
+	if (rhs[0] != '.')
+		strcat(bindname, ".");
+	strcat(bindname, rhs);
+
+		/* rhs_list is no longer needed, since we're done with rhs. */
+	if (rhs_list)
+		hesiod_free_list(context, rhs_list);
+
+		/* Make a copy of the result and return it to the caller. */
+	ret = strdup(bindname);
+	if (!ret)
+		errno = ENOMEM;
+	return ret;
+}
+
+/*
+ * hesiod_resolve --
+ *	Given a hesiod name and type, return an array of strings returned
+ *	by the resolver.
+ */
+char **
+hesiod_resolve(context, name, type)
+	void		*context;
+	const char	*name;
+	const char	*type;
+{
+	struct hesiod_p	*ctx = (struct hesiod_p *) context;
+	char		*bindname, **retvec;
+
+	bindname = hesiod_to_bind(context, name, type);
+	if (!bindname)
+		return NULL;
+
+	retvec = get_txt_records(ctx->classes[0], bindname);
+	if (retvec == NULL && errno == ENOENT && ctx->classes[1])
+		retvec = get_txt_records(ctx->classes[1], bindname);
+
+	free(bindname);
+	return retvec;
+}
+
+/*ARGSUSED*/
+void 
+hesiod_free_list(context, list)
+	void	 *context;
+	char	**list;
+{
+	char  **p;
+
+	if (list == NULL)
+		return;
+	for (p = list; *p; p++)
+		free(*p);
+	free(list);
+}
+
+
+/* read_config_file --
+ *	Parse the /etc/hesiod.conf file.  Returns 0 on success,
+ *	-1 on failure.  On failure, it might leave values in ctx->lhs
+ *	or ctx->rhs which need to be freed by the caller.
+ */
+static int 
+read_config_file(ctx, filename)
+	struct hesiod_p	*ctx;
+	const char	*filename;
+{
+	char	*key, *data, *p, **which;
+	char	 buf[MAXDNAME + 7];
+	int	 n;
+	FILE	*fp;
+
+		/* Set default query classes. */
+	ctx->classes[0] = C_IN;
+	ctx->classes[1] = C_HS;
+
+		/* Try to open the configuration file. */
+	fp = fopen(filename, "r");
+	if (!fp) {
+		/* Use compiled in default domain names. */
+		ctx->lhs = strdup(DEF_LHS);
+		ctx->rhs = strdup(DEF_RHS);
+		if (ctx->lhs && ctx->rhs)
+			return 0;
+		else {
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+	ctx->lhs = NULL;
+	ctx->rhs = NULL;
+	while (fgets(buf, sizeof(buf), fp) != NULL) {
+		p = buf;
+		if (*p == '#' || *p == '\n' || *p == '\r')
+			continue;
+		while (*p == ' ' || *p == '\t')
+			p++;
+		key = p;
+		while (*p != ' ' && *p != '\t' && *p != '=')
+			p++;
+		*p++ = 0;
+
+		while (isspace(*p) || *p == '=')
+			p++;
+		data = p;
+		while (!isspace(*p))
+			p++;
+		*p = 0;
+
+		if (strcasecmp(key, "lhs") == 0 ||
+		    strcasecmp(key, "rhs") == 0) {
+			which = (strcasecmp(key, "lhs") == 0)
+			    ? &ctx->lhs : &ctx->rhs;
+			*which = strdup(data);
+			if (!*which) {
+				errno = ENOMEM;
+				return -1;
+			}
+		} else {
+			if (strcasecmp(key, "classes") == 0) {
+				n = 0;
+				while (*data && n < 2) {
+					p = data;
+					while (*p && *p != ',')
+						p++;
+					if (*p)
+						*p++ = 0;
+					if (strcasecmp(data, "IN") == 0)
+						ctx->classes[n++] = C_IN;
+					else
+						if (strcasecmp(data, "HS") == 0)
+							ctx->classes[n++] =
+							    C_HS;
+					data = p;
+				}
+				while (n < 2)
+					ctx->classes[n++] = 0;
+			}
+		}
+	}
+	fclose(fp);
+
+	if (!ctx->rhs || ctx->classes[0] == 0 ||
+	    ctx->classes[0] == ctx->classes[1]) {
+		errno = ENOEXEC;
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ * get_txt_records --
+ *	Given a DNS class and a DNS name, do a lookup for TXT records, and
+ *	return a list of them.
+ */
+static char **
+get_txt_records(qclass, name)
+	int		 qclass;
+	const char	*name;
+{
+	HEADER		*hp;
+	unsigned char	 qbuf[PACKETSZ], abuf[MAX_HESRESP], *p, *eom, *eor;
+	char		*dst, **list;
+	int		 ancount, qdcount, i, j, n, skip, type, class, len;
+
+		/* Make sure the resolver is initialized. */
+	if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+		return NULL;
+
+		/* Construct the query. */
+	n = res_mkquery(QUERY, name, qclass, T_TXT, NULL, 0,
+	    NULL, qbuf, PACKETSZ);
+	if (n < 0)
+		return NULL;
+
+		/* Send the query. */
+	n = res_send(qbuf, n, abuf, MAX_HESRESP);
+	if (n < 0) {
+		errno = ECONNREFUSED;
+		return NULL;
+	}
+		/* Parse the header of the result. */
+	hp = (HEADER *) (void *) abuf;
+	ancount = ntohs(hp->ancount);
+	qdcount = ntohs(hp->qdcount);
+	p = abuf + sizeof(HEADER);
+	eom = abuf + n;
+
+		/*
+		 * Skip questions, trying to get to the answer section
+		 * which follows.
+		 */
+	for (i = 0; i < qdcount; i++) {
+		skip = dn_skipname(p, eom);
+		if (skip < 0 || p + skip + QFIXEDSZ > eom) {
+			errno = EMSGSIZE;
+			return NULL;
+		}
+		p += skip + QFIXEDSZ;
+	}
+
+		/* Allocate space for the text record answers. */
+	list = malloc((ancount + 1) * sizeof(char *));
+	if (!list) {
+		errno = ENOMEM;
+		return NULL;
+	}
+		/* Parse the answers. */
+	j = 0;
+	for (i = 0; i < ancount; i++) {
+		/* Parse the header of this answer. */
+		skip = dn_skipname(p, eom);
+		if (skip < 0 || p + skip + 10 > eom)
+			break;
+		type = p[skip + 0] << 8 | p[skip + 1];
+		class = p[skip + 2] << 8 | p[skip + 3];
+		len = p[skip + 8] << 8 | p[skip + 9];
+		p += skip + 10;
+		if (p + len > eom) {
+			errno = EMSGSIZE;
+			break;
+		}
+		/* Skip entries of the wrong class and type. */
+		if (class != qclass || type != T_TXT) {
+			p += len;
+			continue;
+		}
+		/* Allocate space for this answer. */
+		list[j] = malloc((size_t)len);
+		if (!list[j]) {
+			errno = ENOMEM;
+			break;
+		}
+		dst = list[j++];
+
+		/* Copy answer data into the allocated area. */
+		eor = p + len;
+		while (p < eor) {
+			n = (unsigned char) *p++;
+			if (p + n > eor) {
+				errno = EMSGSIZE;
+				break;
+			}
+			memcpy(dst, p, (size_t)n);
+			p += n;
+			dst += n;
+		}
+		if (p < eor) {
+			errno = EMSGSIZE;
+			break;
+		}
+		*dst = 0;
+	}
+
+		/*
+		 * If we didn't terminate the loop normally, something
+		 * went wrong.
+		 */
+	if (i < ancount) {
+		for (i = 0; i < j; i++)
+			free(list[i]);
+		free(list);
+		return NULL;
+	}
+	if (j == 0) {
+		errno = ENOENT;
+		free(list);
+		return NULL;
+	}
+	list[j] = NULL;
+	return list;
+}
+
+		/*
+		 *	COMPATIBILITY FUNCTIONS
+		 */
+
+static int	  inited = 0;
+static void	 *context;
+static int	  errval = HES_ER_UNINIT;
+
+int
+hes_init()
+{
+	init_context();
+	return errval;
+}
+
+char *
+hes_to_bind(name, type)
+	const char	*name;
+	const char	*type;
+{
+	static	char	*bindname;
+	if (init_context() < 0)
+		return NULL;
+	if (bindname)
+		free(bindname);
+	bindname = hesiod_to_bind(context, name, type);
+	if (!bindname)
+		translate_errors();
+	return bindname;
+}
+
+char **
+hes_resolve(name, type)
+	const char	*name;
+	const char	*type;
+{
+	static char	**list;
+
+	if (init_context() < 0)
+		return NULL;
+
+	/*
+	 * In the old Hesiod interface, the caller was responsible for
+	 * freeing the returned strings but not the vector of strings itself.
+	 */
+	if (list)
+		free(list);
+
+	list = hesiod_resolve(context, name, type);
+	if (!list)
+		translate_errors();
+	return list;
+}
+
+int
+hes_error()
+{
+	return errval;
+}
+
+void
+hes_free(hp)
+	char **hp;
+{
+	hesiod_free_list(context, hp);
+}
+
+static int
+init_context()
+{
+	if (!inited) {
+		inited = 1;
+		if (hesiod_init(&context) < 0) {
+			errval = HES_ER_CONFIG;
+			return -1;
+		}
+		errval = HES_ER_OK;
+	}
+	return 0;
+}
+
+static void
+translate_errors()
+{
+	switch (errno) {
+	case ENOENT:
+		errval = HES_ER_NOTFOUND;
+		break;
+	case ECONNREFUSED:
+	case EMSGSIZE:
+		errval = HES_ER_NET;
+		break;
+	case ENOMEM:
+	default:
+		/* Not a good match, but the best we can do. */
+		errval = HES_ER_CONFIG;
+		break;
+	}
+}
diff --git a/lib/libc/net/name6.c b/lib/libc/net/name6.c
index 8edcb1b..ea08d92 100644
--- a/lib/libc/net/name6.c
+++ b/lib/libc/net/name6.c
@@ -109,6 +109,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdarg.h>
+#include <nsswitch.h>
 #include <unistd.h>
 
 #ifndef _PATH_HOSTS
@@ -169,110 +171,32 @@ static char	*_hgetword(char **pp);
 static int	 _mapped_addr_enabled(void);
 
 static FILE	*_files_open(int *errp);
-static struct	 hostent *_files_ghbyname(const char *name, int af, int *errp);
-static struct	 hostent *_files_ghbyaddr(const void *addr, int addrlen, int af, int *errp);
+static int	 _files_ghbyname(void *, void *, va_list);
+static int	 _files_ghbyaddr(void *, void *, va_list);
 static void	 _files_shent(int stayopen);
 static void	 _files_ehent(void);
 #ifdef YP
-static struct	 hostent *_nis_ghbyname(const char *name, int af, int *errp);
-static struct	 hostent *_nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp);
+static int	 _nis_ghbyname(void *, void *, va_list);
+static int	 _nis_ghbyaddr(void *, void *, va_list);
 #endif
-static struct	 hostent *_dns_ghbyname(const char *name, int af, int *errp);
-static struct	 hostent *_dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp);
+static int	 _dns_ghbyname(void *, void *, va_list);
+static int	 _dns_ghbyaddr(void *, void *, va_list);
 static void	 _dns_shent(int stayopen);
 static void	 _dns_ehent(void);
 #ifdef ICMPNL
-static struct	 hostent *_icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp);
+static int	 _icmp_ghbyaddr(void *, void *, va_list);
 #endif /* ICMPNL */
 
-/*
- * Select order host function.
- */
-#define	MAXHOSTCONF	4
-
-#ifndef HOSTCONF
-#  define	HOSTCONF	"/etc/host.conf"
-#endif /* !HOSTCONF */
-
-struct _hostconf {
-	struct hostent *(*byname)(const char *name, int af, int *errp);
-	struct hostent *(*byaddr)(const void *addr, int addrlen, int af, int *errp);
-};
-
-/* default order */
-static struct _hostconf _hostconf[MAXHOSTCONF] = {
-	{ _dns_ghbyname,	_dns_ghbyaddr },
-	{ _files_ghbyname,	_files_ghbyaddr },
+/* Host lookup order if nsswitch.conf is broken or nonexistant */
+static const ns_src default_src[] = { 
+	{ NSSRC_FILES, NS_SUCCESS },
+	{ NSSRC_DNS, NS_SUCCESS },
 #ifdef ICMPNL
-	{ NULL,			_icmp_ghbyaddr },
-#endif /* ICMPNL */
-};
-
-static int	_hostconf_init_done;
-static void	_hostconf_init(void);
-
-/*
- * Initialize hostconf structure.
- */
-
-static void
-_hostconf_init(void)
-{
-	FILE *fp;
-	int n;
-	char *p, *line;
-	char buf[BUFSIZ];
-
-	_hostconf_init_done = 1;
-	n = 0;
-	p = HOSTCONF;
-	if ((fp = fopen(p, "r")) == NULL)
-		return;
-	while (n < MAXHOSTCONF && fgets(buf, sizeof(buf), fp)) {
-		line = buf;
-		if ((p = _hgetword(&line)) == NULL)
-			continue;
-		do {
-			if (strcmp(p, "hosts") == 0
-			||  strcmp(p, "local") == 0
-			||  strcmp(p, "file") == 0
-			||  strcmp(p, "files") == 0) {
-				_hostconf[n].byname = _files_ghbyname;
-				_hostconf[n].byaddr = _files_ghbyaddr;
-				n++;
-			}
-			else if (strcmp(p, "dns") == 0
-			     ||  strcmp(p, "bind") == 0) {
-				_hostconf[n].byname = _dns_ghbyname;
-				_hostconf[n].byaddr = _dns_ghbyaddr;
-				n++;
-			}
-#ifdef YP
-			else if (strcmp(p, "nis") == 0) {
-				_hostconf[n].byname = _nis_ghbyname;
-				_hostconf[n].byaddr = _nis_ghbyaddr;
-				n++;
-			}
+#define NSSRC_ICMP "icmp"
+	{ NSSRC_ICMP, NS_SUCCESS },
 #endif
-#ifdef ICMPNL
-			else if (strcmp(p, "icmp") == 0) {
-				_hostconf[n].byname = NULL;
-				_hostconf[n].byaddr = _icmp_ghbyaddr;
-				n++;
-			}
-#endif /* ICMPNL */
-		} while ((p = _hgetword(&line)) != NULL);
-	}
-	fclose(fp);
-	if (n < 0) {
-		/* no keyword found. do not change default configuration */
-		return;
-	}
-	for (; n < MAXHOSTCONF; n++) {
-		_hostconf[n].byname = NULL;
-		_hostconf[n].byaddr = NULL;
-	}
-}
+	{ 0 }
+};
 
 /*
  * Check if kernel supports mapped address.
@@ -311,7 +235,14 @@ static struct hostent *
 _ghbyname(const char *name, int af, int flags, int *errp)
 {
 	struct hostent *hp;
-	int i;
+	int i, rval;
+	
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_files_ghbyname, NULL)
+		{ NSSRC_DNS, _dns_ghbyname, NULL },
+		NS_NIS_CB(_nis_ghbyname, NULL)
+		{ 0 }
+	};
 
 	if (flags & AI_ADDRCONFIG) {
 		int s;
@@ -342,13 +273,9 @@ _ghbyname(const char *name, int af, int flags, int *errp)
 		}
 	}
 
-	for (i = 0; i < MAXHOSTCONF; i++) {
-		if (_hostconf[i].byname
-		 && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL)
-			return hp;
-	}
-
-	return NULL;
+	rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyname", default_src,
+			  name, af, errp);
+	return (rval == NS_SUCCESS) ? hp : NULL;
 }
 
 /* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */
@@ -392,9 +319,6 @@ _getipnodebyname_multi(const char *name, int af, int flags, int *errp)
 		return _hpaddr(af, name, &addrbuf, errp);
 	}
 
-	if (!_hostconf_init_done)
-		_hostconf_init();
-
 	*errp = HOST_NOT_FOUND;
 	hp = _ghbyname(name, af, flags, errp);
 
@@ -436,13 +360,23 @@ struct hostent *
 getipnodebyaddr(const void *src, size_t len, int af, int *errp)
 {
 	struct hostent *hp;
-	int i;
+	int i, rval;
 #ifdef INET6
 	struct in6_addr addrbuf;
 #else
 	struct in_addr addrbuf;
 #endif
 
+	static const ns_dtab dtab[] = {
+		NS_FILES_CB(_files_ghbyaddr, NULL)
+		{ NSSRC_DNS, _dns_ghbyaddr, NULL },
+		NS_NIS_CB(_nis_ghbyaddr, NULL)
+#ifdef ICMPNL
+		{ NSSRC_ICMP, _icmp_ghbyaddr, NULL },
+#endif
+		{ 0 }
+	};
+
 	*errp = HOST_NOT_FOUND;
 
 	switch (af) {
@@ -484,15 +418,9 @@ getipnodebyaddr(const void *src, size_t len, int af, int *errp)
 		return NULL;
 	}
 
-	if (!_hostconf_init_done)
-		_hostconf_init();
-	for (i = 0; i < MAXHOSTCONF; i++) {
-		if (_hostconf[i].byaddr
-		&&  (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL)
-			return hp;
-	}
-
-	return NULL;
+	rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyaddr", default_src,
+			  src, len, af, errp);
+	return (rval == NS_SUCCESS) ? hp : NULL;
 }
 
 void
@@ -828,9 +756,12 @@ _files_open(int *errp)
 	return fp;
 }
 
-static struct hostent *
-_files_ghbyname(const char *name, int af, int *errp)
+static int
+_files_ghbyname(void *rval, void *cb_data, va_list ap)
 {
+	const char *name;
+	int af; 
+	int *errp;
 	int match, nalias;
 	char *p, *line, *addrstr, *cname;
 	FILE *fp;
@@ -840,8 +771,14 @@ _files_ghbyname(const char *name, int af, int *errp)
 	char buf[BUFSIZ];
 	int af0 = af;
 
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
+	errp = va_arg(ap, int *);
+
+	*(struct hostent **)rval = NULL;
+
 	if ((fp = _files_open(errp)) == NULL)
-		return NULL;
+		return NS_UNAVAIL;
 	rethp = hp = NULL;
 
 	while (fgets(buf, sizeof(buf), fp)) {
@@ -906,12 +843,17 @@ _files_ghbyname(const char *name, int af, int *errp)
 		rethp = _hpmerge(rethp, hp, errp);
 	}
 	fclose(fp);
-	return rethp;
+	*(struct hostent **)rval = rethp;
+	return (rethp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
-static struct hostent *
-_files_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
+static int
+_files_ghbyaddr(void *rval, void *cb_data, va_list ap)
 {
+	const void *addr; 
+	int addrlen; 
+	int af; 
+	int *errp;
 	int nalias;
 	char *p, *line;
 	FILE *fp;
@@ -920,8 +862,15 @@ _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 	union inx_addr addrbuf;
 	char buf[BUFSIZ];
 
+	addr = va_arg(ap, const void *);
+	addrlen = va_arg(ap, int);
+	af = va_arg(ap, int);
+	errp = va_arg(ap, int *);
+
+	*(struct hostent**)rval = NULL;
+
 	if ((fp = _files_open(errp)) == NULL)
-		return NULL;
+		return NS_UNAVAIL;
 	hp = NULL;
 	while (fgets(buf, sizeof(buf), fp)) {
 		line = buf;
@@ -950,7 +899,8 @@ _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 		break;
 	}
 	fclose(fp);
-	return hp;
+	*(struct hostent **)rval = hp;
+	return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
 #ifdef YP
@@ -959,11 +909,18 @@ _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
  *
  * XXX actually a hack, these are INET4 specific.
  */
-static struct hostent *
-_nis_ghbyname(const char *name, int af, int *errp)
+static int
+_nis_ghbyname(void *rval, void *cb_data, va_list ap)
 {
+	const char *name;
+	int af;
+	int *errp;
 	struct hostent *hp = NULL;
 
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
+	errp = va_arg(ap, int *);
+	
 	if (af == AF_UNSPEC)
 		af = AF_INET;
 	if (af == AF_INET) {
@@ -971,21 +928,32 @@ _nis_ghbyname(const char *name, int af, int *errp)
 		if (hp != NULL)
 			hp = _hpcopy(hp, errp);
 	}
-	return (hp);
+	
+	*(struct hostent **)rval = hp;
+	return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 	
 }
 
-static struct hostent *
-_nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
+static int
+_nis_ghbyaddr(void *rval, void *cb_data, va_list ap)
 {
+	const void *addr;
+	int addrlen;
+	int af;
+	int *errp;
 	struct hostent *hp = NULL;
 
+	addr = va_arg(ap, const void *);
+	addrlen = va_arg(ap, int);
+	af = va_arg(ap, int);
+
 	if (af == AF_INET) {
 		hp = _gethostbynisaddr(addr, addrlen, af);
 		if (hp != NULL)
 			hp = _hpcopy(hp, errp);
 	}
-	return (hp);
+	*(struct hostent **)rval = hp;
+	return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 #endif
 
@@ -1486,14 +1454,21 @@ _res_search_multi(name, rtl, errp)
 	return (NULL);
 }
 
-static struct hostent *
-_dns_ghbyname(const char *name, int af, int *errp)
+static int
+_dns_ghbyname(void *rval, void *cb_data, va_list ap)
 {
+	const char *name;
+	int af;
+	int *errp;
 	struct __res_type_list *rtl, rtl4;
 #ifdef INET6
 	struct __res_type_list rtl6;
 #endif
 
+	name = va_arg(ap, const char *);
+	af = va_arg(ap, int);
+	errp = va_arg(ap, int *);
+
 #ifdef INET6
 	switch (af) {
 	case AF_UNSPEC:
@@ -1514,12 +1489,17 @@ _dns_ghbyname(const char *name, int af, int *errp)
 	SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
 	rtl = &rtl4;
 #endif
-	return(_res_search_multi(name, rtl, errp));
+	*(struct hostent **)rval = _res_search_multi(name, rtl, errp);
+	return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
 }
 
-static struct hostent *
-_dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
+static int
+_dns_ghbyaddr(void *rval, void *cb_data, va_list ap)
 {
+	const void *addr;
+	int addrlen;
+	int af;
+	int *errp;
 	int n;
 	struct hostent *hp;
 	u_char c, *cp;
@@ -1533,16 +1513,23 @@ _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 	char qbuf[MAXDNAME+1];
 	char *hlist[2];
 
+	addr = va_arg(ap, const void *);
+	addrlen = va_arg(ap, int);
+	af = va_arg(ap, int);
+	errp = va_arg(ap, int *);
+
+	*(struct hostent **)rval = NULL;
+
 #ifdef INET6
 	/* XXX */
 	if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr))
-		return NULL;
+		return NS_NOTFOUND;
 #endif
 
 	if ((_res.options & RES_INIT) == 0) {
 		if (res_init() < 0) {
 			*errp = h_errno;
-			return NULL;
+			return NS_UNAVAIL;
 		}
 	}
 	memset(&hbuf, 0, sizeof(hbuf));
@@ -1585,17 +1572,18 @@ _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 	n = res_query(qbuf, C_IN, T_PTR, buf.buf, sizeof buf.buf);
 	if (n < 0) {
 		*errp = h_errno;
-		return NULL;
+		return NS_UNAVAIL;
 	}
 	hp = getanswer(&buf, n, qbuf, T_PTR, &hbuf, errp);
 	if (!hp)
-		return NULL;
+		return NS_NOTFOUND;
 	hbuf.h_addrtype = af;
 	hbuf.h_length = addrlen;
 	hbuf.h_addr_list = hlist;
 	hlist[0] = (char *)addr;
 	hlist[1] = NULL;
-	return _hpcopy(&hbuf, errp);
+	*(struct hostent **)rval = _hpcopy(&hbuf, errp);
+	return NS_SUCCESS;
 }
 
 static void
diff --git a/lib/libc/net/nsdispatch.3 b/lib/libc/net/nsdispatch.3
new file mode 100644
index 0000000..bd6366e
--- /dev/null
+++ b/lib/libc/net/nsdispatch.3
@@ -0,0 +1,231 @@
+.\"	$NetBSD: nsdispatch.3,v 1.8 1999/03/22 19:44:53 garbled Exp $
+.\"	$FreeBSD$
+.\"
+.\" Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Luke Mewburn.
+.\"
+.\" 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. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"        This product includes software developed by the NetBSD
+.\"        Foundation, Inc. and its contributors.
+.\" 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+.\"
+.Dd January 19, 1999
+.Dt NSDISPATCH 3
+.Os
+.Sh NAME
+.Nm nsdispatch
+.Nd name-service switch dispatcher routine
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.Fd #include <nsswitch.h>
+.Ft int
+.Fo nsdispatch
+.Fa "void *retval"
+.Fa "const ns_dtab dtab[]"
+.Fa "const char *database"
+.Fa "const char *method"
+.Fa "const ns_src defaults[]"
+.Fa "..."
+.Fc
+.Sh DESCRIPTION
+The
+.Fn nsdispatch
+function invokes the callback functions specified in 
+.Va dtab
+in the order given in
+.Pa /etc/nsswitch.conf
+for the database
+.Va database
+until a successful entry is found.
+.Pp
+.Va retval
+is passed to each callback function to modify as necessary
+(to pass back to the caller of
+.Fn nsdispatch )
+.Pp
+.Va dtab
+is an array of
+.Va ns_dtab
+structures, which have the following format:
+.Bd -literal -offset indent
+typedef struct {
+	const char *src;
+	int (*cb)(void *retval, void *cb_data, va_list ap);
+	void *cb_data;
+} ns_dtab;
+.Ed
+.Pp
+.Bd -ragged -offset indent
+For each source type that is implemented, an entry with
+.Va src
+set to the name of the source,
+.Va cb
+defined as a function which handles that source, and
+.Va cb_data
+is used to pass arbritrary data to the callback function.
+The last entry in
+.Va dtab
+should contain
+.Dv NULL
+values for
+.Va src , 
+.Va cb ,
+and
+.Va cb_data .
+.Ed
+.Pp
+.Va method
+is usually the name of the function calling
+.Fn nsdispatch .
+When dynamic loading is supported, a symbol constructed from
+.Va database ,
+the current source, and
+.Va method
+will be used as the name to invoke the dynamically loaded function.
+.Pp
+.Va defaults
+contains a list of default sources to try in the case of
+a missing or corrupt
+.Xr nsswitch.conf 5 ,
+or if there isn't a relevant entry for
+.Va database .
+It is an array of
+.Va ns_src
+structures, which have the following format:
+.Bd -literal -offset indent
+typedef struct {
+	const char *src;
+	u_int32_t flags;
+} ns_src;
+.Ed
+.Pp
+.Bd -ragged -offset indent
+For each default source type, an entry with
+.Va src
+set to the name of the source, and
+.Va flags
+set to the relevant flags
+(usually 
+.Dv NS_SUCCESS ;
+refer to
+.Sx Callback return values
+for more information).
+The last entry in
+.Va defaults
+should have
+.Va src
+set to
+.Dv NULL
+and
+.Va flags
+set to 0.
+.Pp
+For convenience, a global variable defined as:
+.Dl extern const ns_src __nsdefaultsrc[];
+exists which contains a single default entry for
+.Sq files
+for use by callers which don't require complicated default rules.
+.Ed
+.Pp
+.Va Sq ...
+are optional extra arguments, which
+are passed to the appropriate callback function as a variable argument
+list of the type
+.Va va_list .
+.Ss Valid source types
+Whilst there is support for arbitrary sources, the following
+#defines for commonly implementated sources are available:
+.Bl -column NS_COMPAT COMPAT -offset indent
+.Sy #define	value
+.It NSSRC_FILES	"files"
+.It NSSRC_DNS	"dns"
+.It NSSRC_NIS	"nis"
+.It NSSRC_COMPAT	"compat"
+.El
+.Pp
+Refer to
+.Xr nsswitch.conf 5
+for a complete description of what each source type is.
+.Pp
+.Ss Callback return values
+The callback functions should return one of the following values
+depending upon status of the lookup:
+.Bl -column NS_NOTFOUND -offset indent
+.Sy "Return value"	Status code
+.It NS_SUCCESS	success
+.It NS_NOTFOUND	notfound
+.It NS_UNAVAIL	unavail
+.It NS_TRYAGAIN	tryagain
+.El
+.Pp
+Refer to
+.Xr nsswitch.conf 5
+for a complete description of what each status code is.
+.Pp
+.Nm
+returns the value of the callback that caused the dispatcher to finish,
+or NS_NOTFOUND otherwise.
+.Sh SEE ALSO
+.Xr hesiod 3 ,
+.Xr stdarg 3 ,
+.Xr ypclnt 3 ,
+.Xr nsswitch.conf 5
+.Sh HISTORY
+The
+.Nm
+routines first appeared in
+.Fx 4.1 .
+They were imported from the
+.Nx 
+Project,
+where they appeared first in 
+.Nx 1.4 .
+.Sh AUTHORS
+Luke Mewburn
+.Aq lukem@netbsd.org
+wrote this freely distributable name-service switch implementation,
+using ideas from the
+.Tn ULTRIX
+.Xr svc.conf 5
+and
+.Tn Solaris
+.Xr nsswitch.conf 4
+manual pages.
+.Sh BUGS
+The
+.Nm
+routines are not thread safe.
+This will be rectified in the future.
+.Pp
+Currently there is no support for dynamically loadable dispatcher callback
+functions.
+It is anticipated that this will be added in the future in the back-end
+without requiring changes to code that invokes
+.Fn nsdispatch .
diff --git a/lib/libc/net/nsdispatch.c b/lib/libc/net/nsdispatch.c
new file mode 100644
index 0000000..311b89d
--- /dev/null
+++ b/lib/libc/net/nsdispatch.c
@@ -0,0 +1,270 @@
+/*	$NetBSD: nsdispatch.c,v 1.9 1999/01/25 00:16:17 lukem Exp $	*/
+
+/*-
+ * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Luke Mewburn.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = 
+  "$FreeBSD$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <fcntl.h>
+#define _NS_PRIVATE
+#include <nsswitch.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/*
+ * default sourcelist: `files'
+ */
+const ns_src __nsdefaultsrc[] = {
+	{ NSSRC_FILES, NS_SUCCESS },
+	{ 0 },
+};
+
+
+static	int			 _nsmapsize = 0;
+static	ns_dbt			*_nsmap = NULL;
+
+/*
+ * size of dynamic array chunk for _nsmap and _nsmap[x].srclist
+ */
+#define NSELEMSPERCHUNK		8
+
+
+int	_nscmp __P((const void *, const void *));
+
+
+int
+_nscmp(a, b)
+	const void *a;
+	const void *b;
+{
+	return (strcasecmp(((const ns_dbt *)a)->name,
+	    ((const ns_dbt *)b)->name));
+}
+
+
+void
+_nsdbtaddsrc(dbt, src)
+	ns_dbt		*dbt;
+	const ns_src	*src;
+{
+	if ((dbt->srclistsize % NSELEMSPERCHUNK) == 0) {
+		dbt->srclist = (ns_src *)realloc(dbt->srclist,
+		    (dbt->srclistsize + NSELEMSPERCHUNK) * sizeof(ns_src));
+		if (dbt->srclist == NULL)
+			err(1, "nsdispatch: memory allocation failure");
+	}
+	memmove(&dbt->srclist[dbt->srclistsize++], src, sizeof(ns_src));
+}
+
+
+void
+_nsdbtdump(dbt)
+	const ns_dbt *dbt;
+{
+	int i;
+
+	printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
+	    dbt->srclistsize == 1 ? "" : "s");
+	for (i = 0; i < dbt->srclistsize; i++) {
+		printf(" %s", dbt->srclist[i].name);
+		if (!(dbt->srclist[i].flags &
+		    (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
+		    (dbt->srclist[i].flags & NS_SUCCESS))
+			continue;
+		printf(" [");
+		if (!(dbt->srclist[i].flags & NS_SUCCESS))
+			printf(" SUCCESS=continue");
+		if (dbt->srclist[i].flags & NS_UNAVAIL)
+			printf(" UNAVAIL=return");
+		if (dbt->srclist[i].flags & NS_NOTFOUND)
+			printf(" NOTFOUND=return");
+		if (dbt->srclist[i].flags & NS_TRYAGAIN)
+			printf(" TRYAGAIN=return");
+		printf(" ]");
+	}
+	printf("\n");
+}
+
+
+const ns_dbt *
+_nsdbtget(name)
+	const char	*name;
+{
+	static	time_t	 confmod;
+
+	struct stat	 statbuf;
+	ns_dbt		 dbt;
+
+	extern	FILE 	*_nsyyin;
+	extern	int	 _nsyyparse __P((void));
+
+	dbt.name = name;
+
+	if (confmod) {
+		if (stat(_PATH_NS_CONF, &statbuf) == -1)
+			return (NULL);
+		if (confmod < statbuf.st_mtime) {
+			int i, j;
+
+			for (i = 0; i < _nsmapsize; i++) {
+				for (j = 0; j < _nsmap[i].srclistsize; j++) {
+					if (_nsmap[i].srclist[j].name != NULL) {
+						/*LINTED const cast*/
+						free((void *)
+						    _nsmap[i].srclist[j].name);
+					}
+				}
+				if (_nsmap[i].srclist)
+					free(_nsmap[i].srclist);
+				if (_nsmap[i].name) {
+					/*LINTED const cast*/
+					free((void *)_nsmap[i].name);
+				}
+			}
+			if (_nsmap)
+				free(_nsmap);
+			_nsmap = NULL;
+			_nsmapsize = 0;
+			confmod = 0;
+		}
+	}
+	if (!confmod) {
+		if (stat(_PATH_NS_CONF, &statbuf) == -1)
+			return (NULL);
+		_nsyyin = fopen(_PATH_NS_CONF, "r");
+		if (_nsyyin == NULL)
+			return (NULL);
+		_nsyyparse();
+		(void)fclose(_nsyyin);
+		qsort(_nsmap, (size_t)_nsmapsize, sizeof(ns_dbt), _nscmp);
+		confmod = statbuf.st_mtime;
+	}
+	return (bsearch(&dbt, _nsmap, (size_t)_nsmapsize, sizeof(ns_dbt),
+	    _nscmp));
+}
+
+
+void
+_nsdbtput(dbt)
+	const ns_dbt *dbt;
+{
+	int	i;
+
+	for (i = 0; i < _nsmapsize; i++) {
+		if (_nscmp(dbt, &_nsmap[i]) == 0) {
+					/* overwrite existing entry */
+			if (_nsmap[i].srclist != NULL)
+				free(_nsmap[i].srclist);
+			memmove(&_nsmap[i], dbt, sizeof(ns_dbt));
+			return;
+		}
+	}
+
+	if ((_nsmapsize % NSELEMSPERCHUNK) == 0) {
+		_nsmap = (ns_dbt *)realloc(_nsmap,
+		    (_nsmapsize + NSELEMSPERCHUNK) * sizeof(ns_dbt));
+		if (_nsmap == NULL)
+			err(1, "nsdispatch: memory allocation failure");
+	}
+	memmove(&_nsmap[_nsmapsize++], dbt, sizeof(ns_dbt));
+}
+
+
+int
+#if __STDC__
+nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
+	    const char *method, const ns_src defaults[], ...)
+#else
+nsdispatch(retval, disp_tab, database, method, defaults, va_alist)
+	void		*retval;
+	const ns_dtab	 disp_tab[];
+	const char	*database;
+	const char	*method;
+	const ns_src	 defaults[];
+	va_dcl
+#endif
+{
+	va_list		 ap;
+	int		 i, curdisp, result;
+	const ns_dbt	*dbt;
+	const ns_src	*srclist;
+	int		 srclistsize;
+
+	dbt = _nsdbtget(database);
+	if (dbt != NULL) {
+		srclist = dbt->srclist;
+		srclistsize = dbt->srclistsize;
+	} else {
+		srclist = defaults;
+		srclistsize = 0;
+		while (srclist[srclistsize].name != NULL)
+			srclistsize++;
+	}
+	result = 0;
+
+	for (i = 0; i < srclistsize; i++) {
+		for (curdisp = 0; disp_tab[curdisp].src != NULL; curdisp++)
+			if (strcasecmp(disp_tab[curdisp].src,
+			    srclist[i].name) == 0)
+				break;
+		result = 0;
+		if (disp_tab[curdisp].callback) {
+#if __STDC__
+			va_start(ap, defaults);
+#else
+			va_start(ap);
+#endif
+			result = disp_tab[curdisp].callback(retval,
+			    disp_tab[curdisp].cb_data, ap);
+			va_end(ap);
+			if (result & srclist[i].flags) {
+				break;
+			}
+		}
+	}
+	return (result ? result : NS_NOTFOUND);
+}
diff --git a/lib/libc/net/nslexer.l b/lib/libc/net/nslexer.l
new file mode 100644
index 0000000..104cfbb
--- /dev/null
+++ b/lib/libc/net/nslexer.l
@@ -0,0 +1,116 @@
+%{
+/*	$NetBSD: nslexer.l,v 1.3 1999/01/25 00:16:17 lukem Exp $	*/
+
+/*-
+ * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Luke Mewburn.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = 
+  "$FreeBSD$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <ctype.h>
+#include <err.h>
+#define _NS_PRIVATE
+#include <nsswitch.h>
+#include <string.h>
+
+#include "nsparser.h"
+
+#define YY_NO_UNPUT
+
+%}
+
+%option yylineno
+
+BLANK		[ \t]
+CR		\n
+STRING		[a-zA-Z][a-zA-Z0-9_]*
+
+%%
+
+{BLANK}+	;			/* skip whitespace */
+
+#.*		;			/* skip comments */
+
+\\{CR}		;			/* allow continuation */
+
+{CR}		return NL;
+
+[sS][uU][cC][cC][eE][sS][sS]		return SUCCESS;
+[uU][nN][aA][vV][aA][iI][lL]		return UNAVAIL;
+[nN][oO][tT][fF][oO][uU][nN][dD]	return NOTFOUND;
+[tT][rR][yY][aA][gG][aA][iI][nN]	return TRYAGAIN;
+
+[rR][eE][tT][uU][rR][nN]		return RETURN;
+[cC][oO][nN][tT][iI][nN][uU][eE]	return CONTINUE;
+
+{STRING}	{
+			char *p;
+			int i;
+
+			if ((p = strdup(yytext)) == NULL)
+				err(1, "nsdispatch: memory allocation failure");
+
+			for (i = 0; i < strlen(p); i++) {
+				if (isupper((unsigned char)p[i]))
+					p[i] = tolower((unsigned char)p[i]);
+			}
+			_nsyylval.str = p;
+			return STRING;
+		}
+
+[:=\[\]]	return yytext[0];
+
+.		;	/* ignore all else */
+
+%%
+
+#undef _nsyywrap
+int
+_nsyywrap()
+{
+	return 1;
+} /* _nsyywrap */
+
+void
+_nsyyerror(msg)
+	const char *msg;
+{
+
+	 warnx("%s line %d: %s at '%s'", _PATH_NS_CONF, yylineno, msg, yytext);
+} /* _nsyyerror */
diff --git a/lib/libc/net/nsparser.y b/lib/libc/net/nsparser.y
new file mode 100644
index 0000000..b39f011
--- /dev/null
+++ b/lib/libc/net/nsparser.y
@@ -0,0 +1,175 @@
+%{
+/*	$NetBSD: nsparser.y,v 1.3 1999/01/25 00:16:18 lukem Exp $	*/
+
+/*-
+ * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Luke Mewburn.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid =
+  "$FreeBSD$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <err.h>
+#define _NS_PRIVATE
+#include <nsswitch.h>
+#include <stdio.h>
+#include <string.h>
+
+
+static	void	_nsaddsrctomap __P((const char *));
+
+static	ns_dbt		curdbt;
+static	ns_src		cursrc;
+%}
+
+%union {
+	char *str;
+	int   mapval;
+}
+
+%token	NL
+%token	SUCCESS UNAVAIL NOTFOUND TRYAGAIN
+%token	RETURN CONTINUE
+%token	<str> STRING
+
+%type	<mapval> Status Action
+
+%%
+
+File
+	:	/* empty */
+	| Lines
+	;
+
+Lines
+	: Entry
+	| Lines Entry
+	;
+
+Entry
+	: NL
+	| Database ':' NL
+	| Database ':' Srclist NL
+		{
+			_nsdbtput(&curdbt);
+		}
+	;
+
+Database
+	: STRING
+		{
+			curdbt.name = yylval.str;
+			curdbt.srclist = NULL;
+			curdbt.srclistsize = 0;
+		}
+	;
+
+Srclist
+	: Item
+	| Srclist Item
+	;
+
+Item
+	: STRING
+		{
+			cursrc.flags = NS_SUCCESS;
+			_nsaddsrctomap($1);
+		}
+	| STRING '[' { cursrc.flags = NS_SUCCESS; } Criteria ']'
+		{
+			_nsaddsrctomap($1);
+		}
+	;
+
+Criteria
+	: Criterion
+	| Criteria Criterion
+	;
+
+Criterion
+	: Status '=' Action
+		{
+			if ($3)		/* if action == RETURN set RETURN bit */
+				cursrc.flags |= $1;  
+			else		/* else unset it */
+				cursrc.flags &= ~$1;
+		}
+	;
+
+Status
+	: SUCCESS	{ $$ = NS_SUCCESS; }
+	| UNAVAIL	{ $$ = NS_UNAVAIL; }
+	| NOTFOUND	{ $$ = NS_NOTFOUND; }
+	| TRYAGAIN	{ $$ = NS_TRYAGAIN; }
+	;
+
+Action
+	: RETURN	{ $$ = 1L; }
+	| CONTINUE	{ $$ = 0L; }
+	;
+
+%%
+
+static void
+_nsaddsrctomap(elem)
+	const char *elem;
+{
+	int		i, lineno;
+	extern int	_nsyylineno;
+	extern char *	_nsyytext;
+
+	lineno = _nsyylineno - (*_nsyytext == '\n' ? 1 : 0);
+	if (curdbt.srclistsize > 0) {
+		if ((strcasecmp(elem, NSSRC_COMPAT) == 0) ||
+		    (strcasecmp(curdbt.srclist[0].name, NSSRC_COMPAT) == 0)) {
+				/* XXX: syslog the following */
+			warnx("%s line %d: 'compat' used with other sources",
+			    _PATH_NS_CONF, lineno);
+			return;
+		}
+	}
+	for (i = 0; i < curdbt.srclistsize; i++) {
+		if (strcasecmp(curdbt.srclist[i].name, elem) == 0) {
+				/* XXX: syslog the following */
+			warnx("%s line %d: duplicate source '%s'",
+			    _PATH_NS_CONF, lineno, elem);
+			return;
+		}
+	}
+	cursrc.name = elem;
+	_nsdbtaddsrc(&curdbt, &cursrc);
+}