BIND 4.9.5-P1.

libresolv and include are required until the new resolver gets integrated
into libc.

1 files changed, 967 insertions, 0 deletions

diff --git a/usr.sbin/named/libresolv/gethnamaddr.c b/usr.sbin/named/libresolv/gethnamaddr.c
new file mode 100644
index 00000000000..aa93b257643
--- /dev/null
+++ b/usr.sbin/named/libresolv/gethnamaddr.c
@@ -0,0 +1,967 @@
+/*	$OpenBSD: gethnamaddr.c,v 1.1 1997/03/12 10:42:02 downsj Exp $	*/
+
+/*
+ * ++Copyright++ 1985, 1988, 1993
+ * -
+ * Copyright (c) 1985, 1988, 1993
+ *    The Regents of the University of California.  All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ * 	This product includes software developed by the University of
+ * 	California, Berkeley and its contributors.
+ * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
+ * -
+ * Portions Copyright (c) 1993 by Digital Equipment Corporation.
+ * 
+ * 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, and that
+ * the name of Digital Equipment Corporation not be used in advertising or
+ * publicity pertaining to distribution of the document or software without
+ * specific, written prior permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
+ * CORPORATION 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--
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
+static char rcsid[] = "$From: gethnamaddr.c,v 8.20 1996/09/28 06:51:07 vixie Exp $";
+#else
+static char rcsid[] = "$OpenBSD: gethnamaddr.c,v 1.1 1997/03/12 10:42:02 downsj Exp $";
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <stdio.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <ctype.h>
+#include <errno.h>
+#include <syslog.h>
+
+#ifndef LOG_AUTH
+# define LOG_AUTH 0
+#endif
+
+#define MULTI_PTRS_ARE_ALIASES 1	/* XXX - experimental */
+
+#if defined(BSD) && (BSD >= 199103) && defined(AF_INET6)
+# include <stdlib.h>
+# include <string.h>
+#else
+# include "../conf/portability.h"
+#endif
+
+#if defined(USE_OPTIONS_H)
+# include <../conf/options.h>
+#endif
+
+#ifdef SPRINTF_CHAR
+# define SPRINTF(x) strlen(sprintf/**/x)
+#else
+# define SPRINTF(x) ((size_t)sprintf x)
+#endif
+
+#define	MAXALIASES	35
+#define	MAXADDRS	35
+
+static const char AskedForGot[] =
+			  "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
+
+static char *h_addr_ptrs[MAXADDRS + 1];
+
+static struct hostent host;
+static char *host_aliases[MAXALIASES];
+static char hostbuf[8*1024];
+static u_char host_addr[16];	/* IPv4 or IPv6 */
+static FILE *hostf = NULL;
+static int stayopen = 0;
+
+static void map_v4v6_address __P((const char *src, char *dst));
+static void map_v4v6_hostent __P((struct hostent *hp, char **bp, int *len));
+
+#ifdef RESOLVSORT
+static void addrsort __P((char **, int));
+#endif
+
+#if PACKETSZ > 1024
+#define	MAXPACKET	PACKETSZ
+#else
+#define	MAXPACKET	1024
+#endif
+
+typedef union {
+    HEADER hdr;
+    u_char buf[MAXPACKET];
+} querybuf;
+
+typedef union {
+    int32_t al;
+    char ac;
+} align;
+
+extern int h_errno;
+
+#ifdef DEBUG
+static void
+dprintf(msg, num)
+	char *msg;
+	int num;
+{
+	if (_res.options & RES_DEBUG) {
+		int save = errno;
+
+		printf(msg, num);
+		errno = save;
+	}
+}
+#else
+# define dprintf(msg, num) /*nada*/
+#endif
+
+static struct hostent *
+getanswer(answer, anslen, qname, qtype)
+	const querybuf *answer;
+	int anslen;
+	const char *qname;
+	int qtype;
+{
+	register const HEADER *hp;
+	register const u_char *cp;
+	register int n;
+	const u_char *eom;
+	char *bp, **ap, **hap;
+	int type, class, buflen, ancount, qdcount;
+	int haveanswer, had_error;
+	int toobig = 0;
+	char tbuf[MAXDNAME];
+	const char *tname;
+	int (*name_ok) __P((const char *));
+
+	tname = qname;
+	host.h_name = NULL;
+	eom = answer->buf + anslen;
+	switch (qtype) {
+	case T_A:
+	case T_AAAA:
+		name_ok = res_hnok;
+		break;
+	case T_PTR:
+		name_ok = res_dnok;
+		break;
+	default:
+		return (NULL);	/* XXX should be abort(); */
+	}
+	/*
+	 * find first satisfactory answer
+	 */
+	hp = &answer->hdr;
+	ancount = ntohs(hp->ancount);
+	qdcount = ntohs(hp->qdcount);
+	bp = hostbuf;
+	buflen = sizeof hostbuf;
+	cp = answer->buf + HFIXEDSZ;
+	if (qdcount != 1) {
+		h_errno = NO_RECOVERY;
+		return (NULL);
+	}
+	n = dn_expand(answer->buf, eom, cp, bp, buflen);
+	if ((n < 0) || !(*name_ok)(bp)) {
+		h_errno = NO_RECOVERY;
+		return (NULL);
+	}
+	cp += n + QFIXEDSZ;
+	if (qtype == T_A || qtype == T_AAAA) {
+		/* res_send() has already verified that the query name is the
+		 * same as the one we sent; this just gets the expanded name
+		 * (i.e., with the succeeding search-domain tacked on).
+		 */
+		n = strlen(bp) + 1;		/* for the \0 */
+		host.h_name = bp;
+		bp += n;
+		buflen -= n;
+		/* The qname can be abbreviated, but h_name is now absolute. */
+		qname = host.h_name;
+	}
+	ap = host_aliases;
+	*ap = NULL;
+	host.h_aliases = host_aliases;
+	hap = h_addr_ptrs;
+	*hap = NULL;
+	host.h_addr_list = h_addr_ptrs;
+	haveanswer = 0;
+	had_error = 0;
+	while (ancount-- > 0 && cp < eom && !had_error) {
+		n = dn_expand(answer->buf, eom, cp, bp, buflen);
+		if ((n < 0) || !(*name_ok)(bp)) {
+			had_error++;
+			continue;
+		}
+		cp += n;			/* name */
+		type = _getshort(cp);
+ 		cp += INT16SZ;			/* type */
+		class = _getshort(cp);
+ 		cp += INT16SZ + INT32SZ;	/* class, TTL */
+		n = _getshort(cp);
+		cp += INT16SZ;			/* len */
+		if (class != C_IN) {
+			/* XXX - debug? syslog? */
+			cp += n;
+			continue;		/* XXX - had_error++ ? */
+		}
+		if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
+			if (ap >= &host_aliases[MAXALIASES-1])
+				continue;
+			n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
+			if ((n < 0) || !(*name_ok)(tbuf)) {
+				had_error++;
+				continue;
+			}
+			cp += n;
+			/* Store alias. */
+			*ap++ = bp;
+			n = strlen(bp) + 1;	/* for the \0 */
+			bp += n;
+			buflen -= n;
+			/* Get canonical name. */
+			n = strlen(tbuf) + 1;	/* for the \0 */
+			if (n > buflen) {
+				had_error++;
+				continue;
+			}
+			strcpy(bp, tbuf);
+			host.h_name = bp;
+			bp += n;
+			buflen -= n;
+			continue;
+		}
+		if (qtype == T_PTR && type == T_CNAME) {
+			n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
+			if ((n < 0) || !res_hnok(tbuf)) {
+				had_error++;
+				continue;
+			}
+			cp += n;
+			/* Get canonical name. */
+			n = strlen(tbuf) + 1;	/* for the \0 */
+			if (n > buflen) {
+				had_error++;
+				continue;
+			}
+			strcpy(bp, tbuf);
+			tname = bp;
+			bp += n;
+			buflen -= n;
+			continue;
+		}
+		if (type != qtype) {
+			syslog(LOG_NOTICE|LOG_AUTH,
+	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
+			       qname, p_class(C_IN), p_type(qtype),
+			       p_type(type));
+			cp += n;
+			continue;		/* XXX - had_error++ ? */
+		}
+		switch (type) {
+		case T_PTR:
+			if (strcasecmp(tname, bp) != 0) {
+				syslog(LOG_NOTICE|LOG_AUTH,
+				       AskedForGot, qname, bp);
+				cp += n;
+				continue;	/* XXX - had_error++ ? */
+			}
+			n = dn_expand(answer->buf, eom, cp, bp, buflen);
+			if ((n < 0) || !res_hnok(bp)) {
+				had_error++;
+				break;
+			}
+#if MULTI_PTRS_ARE_ALIASES
+			cp += n;
+			if (!haveanswer)
+				host.h_name = bp;
+			else if (ap < &host_aliases[MAXALIASES-1])
+				*ap++ = bp;
+			else
+				n = -1;
+			if (n != -1) {
+				n = strlen(bp) + 1;	/* for the \0 */
+				bp += n;
+				buflen -= n;
+			}
+			break;
+#else
+			host.h_name = bp;
+			if (_res.options & RES_USE_INET6) {
+				n = strlen(bp) + 1;	/* for the \0 */
+				bp += n;
+				buflen -= n;
+				map_v4v6_hostent(&host, &bp, &buflen);
+			}
+			h_errno = NETDB_SUCCESS;
+			return (&host);
+#endif
+		case T_A:
+		case T_AAAA:
+			if (strcasecmp(host.h_name, bp) != 0) {
+				syslog(LOG_NOTICE|LOG_AUTH,
+				       AskedForGot, host.h_name, bp);
+				cp += n;
+				continue;	/* XXX - had_error++ ? */
+			}
+			if (n != host.h_length) {
+				cp += n;
+				continue;
+			}
+			if (!haveanswer) {
+				register int nn;
+
+				host.h_name = bp;
+				nn = strlen(bp) + 1;	/* for the \0 */
+				bp += nn;
+				buflen -= nn;
+			}
+
+			bp += sizeof(align) - ((u_long)bp % sizeof(align));
+
+			if (bp + n >= &hostbuf[sizeof hostbuf]) {
+				dprintf("size (%d) too big\n", n);
+				had_error++;
+				continue;
+			}
+			if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
+				if (!toobig++)
+					dprintf("Too many addresses (%d)\n",
+						MAXADDRS);
+				cp += n;
+				continue;
+			}
+			bcopy(cp, *hap++ = bp, n);
+			bp += n;
+			buflen -= n;
+			cp += n;
+			break;
+		default:
+			abort();
+		}
+		if (!had_error)
+			haveanswer++;
+	}
+	if (haveanswer) {
+		*ap = NULL;
+		*hap = NULL;
+# if defined(RESOLVSORT)
+		/*
+		 * Note: we sort even if host can take only one address
+		 * in its return structures - should give it the "best"
+		 * address in that case, not some random one
+		 */
+		if (_res.nsort && haveanswer > 1 && qtype == T_A)
+			addrsort(h_addr_ptrs, haveanswer);
+# endif /*RESOLVSORT*/
+		if (!host.h_name) {
+			n = strlen(qname) + 1;	/* for the \0 */
+			if (n > buflen)
+				goto try_again;
+			strcpy(bp, qname);
+			host.h_name = bp;
+			bp += n;
+			buflen -= n;
+		}
+		if (_res.options & RES_USE_INET6)
+			map_v4v6_hostent(&host, &bp, &buflen);
+		h_errno = NETDB_SUCCESS;
+		return (&host);
+	}
+ try_again:
+	h_errno = TRY_AGAIN;
+	return (NULL);
+}
+
+struct hostent *
+gethostbyname(name)
+	const char *name;
+{
+	struct hostent *hp;
+
+	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	if (_res.options & RES_USE_INET6) {
+		hp = gethostbyname2(name, AF_INET6);
+		if (hp)
+			return (hp);
+	}
+	return (gethostbyname2(name, AF_INET));
+}
+
+struct hostent *
+gethostbyname2(name, af)
+	const char *name;
+	int af;
+{
+	querybuf buf;
+	register const char *cp;
+	char *bp;
+	int n, size, type, len;
+	extern struct hostent *_gethtbyname2();
+
+	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+
+	switch (af) {
+	case AF_INET:
+		size = INADDRSZ;
+		type = T_A;
+		break;
+	case AF_INET6:
+		size = IN6ADDRSZ;
+		type = T_AAAA;
+		break;
+	default:
+		h_errno = NETDB_INTERNAL;
+		errno = EAFNOSUPPORT;
+		return (NULL);
+	}
+
+	host.h_addrtype = af;
+	host.h_length = size;
+
+	/*
+	 * if there aren't any dots, it could be a user-level alias.
+	 * this is also done in res_query() since we are not the only
+	 * function that looks up host names.
+	 */
+	if (!strchr(name, '.') && (cp = __hostalias(name)))
+		name = cp;
+
+	/*
+	 * disallow names consisting only of digits/dots, unless
+	 * they end in a dot.
+	 */
+	if (isdigit(name[0]))
+		for (cp = name;; ++cp) {
+			if (!*cp) {
+				if (*--cp == '.')
+					break;
+				/*
+				 * All-numeric, no dot at the end.
+				 * Fake up a hostent as if we'd actually
+				 * done a lookup.
+				 */
+				if (inet_pton(af, name, host_addr) <= 0) {
+					h_errno = HOST_NOT_FOUND;
+					return (NULL);
+				}
+				strncpy(hostbuf, name, MAXDNAME);
+				hostbuf[MAXDNAME] = '\0';
+				bp = hostbuf + MAXDNAME;
+				len = sizeof hostbuf - MAXDNAME;
+				host.h_name = hostbuf;
+				host.h_aliases = host_aliases;
+				host_aliases[0] = NULL;
+				h_addr_ptrs[0] = (char *)host_addr;
+				h_addr_ptrs[1] = NULL;
+				host.h_addr_list = h_addr_ptrs;
+				if (_res.options & RES_USE_INET6)
+					map_v4v6_hostent(&host, &bp, &len);
+				h_errno = NETDB_SUCCESS;
+				return (&host);
+			}
+			if (!isdigit(*cp) && *cp != '.') 
+				break;
+		}
+	if (isxdigit(name[0]) || name[0] == ':')
+		for (cp = name;; ++cp) {
+			if (!*cp) {
+				if (*--cp == '.')
+					break;
+				/*
+				 * All-IPv6-legal, no dot at the end.
+				 * Fake up a hostent as if we'd actually
+				 * done a lookup.
+				 */
+				if (inet_pton(af, name, host_addr) <= 0) {
+					h_errno = HOST_NOT_FOUND;
+					return (NULL);
+				}
+				strncpy(hostbuf, name, MAXDNAME);
+				hostbuf[MAXDNAME] = '\0';
+				bp = hostbuf + MAXDNAME;
+				len = sizeof hostbuf - MAXDNAME;
+				host.h_name = hostbuf;
+				host.h_aliases = host_aliases;
+				host_aliases[0] = NULL;
+				h_addr_ptrs[0] = (char *)host_addr;
+				h_addr_ptrs[1] = NULL;
+				host.h_addr_list = h_addr_ptrs;
+				h_errno = NETDB_SUCCESS;
+				return (&host);
+			}
+			if (!isxdigit(*cp) && *cp != ':' && *cp != '.') 
+				break;
+		}
+
+	if ((n = res_search(name, C_IN, type, buf.buf, sizeof(buf))) < 0) {
+		dprintf("res_search failed (%d)\n", n);
+		if (errno == ECONNREFUSED)
+			return (_gethtbyname2(name, af));
+		return (NULL);
+	}
+	return (getanswer(&buf, n, name, type));
+}
+
+struct hostent *
+gethostbyaddr(addr, len, af)
+	const char *addr;	/* XXX should have been def'd as u_char! */
+	int len, af;
+{
+	const u_char *uaddr = (const u_char *)addr;
+	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;
+	querybuf buf;
+	register struct hostent *hp;
+	char qbuf[MAXDNAME+1], *qp;
+#ifdef SUNSECURITY
+	register struct hostent *rhp;
+	char **haddr;
+	u_long old_options;
+	char hname2[MAXDNAME+1];
+#endif /*SUNSECURITY*/
+	extern struct hostent *_gethtbyaddr();
+	
+	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	if (af == AF_INET6 && len == IN6ADDRSZ &&
+	    (!bcmp(uaddr, mapped, sizeof mapped) ||
+	     !bcmp(uaddr, tunnelled, sizeof tunnelled))) {
+		/* Unmap. */
+		addr += sizeof mapped;
+		uaddr += sizeof mapped;
+		af = AF_INET;
+		len = INADDRSZ;
+	}
+	switch (af) {
+	case AF_INET:
+		size = INADDRSZ;
+		break;
+	case AF_INET6:
+		size = IN6ADDRSZ;
+		break;
+	default:
+		errno = EAFNOSUPPORT;
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	if (size != len) {
+		errno = EINVAL;
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	switch (af) {
+	case AF_INET:
+		(void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",
+			       (uaddr[3] & 0xff),
+			       (uaddr[2] & 0xff),
+			       (uaddr[1] & 0xff),
+			       (uaddr[0] & 0xff));
+		break;
+	case AF_INET6:
+		qp = qbuf;
+		for (n = IN6ADDRSZ - 1; n >= 0; n--) {
+			qp += SPRINTF((qp, "%x.%x.",
+				       uaddr[n] & 0xf,
+				       (uaddr[n] >> 4) & 0xf));
+		}
+		strcpy(qp, "ip6.int");
+		break;
+	default:
+		abort();
+	}
+	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);
+		if (errno == ECONNREFUSED)
+			return (_gethtbyaddr(addr, len, af));
+		return (NULL);
+	}
+	if (!(hp = getanswer(&buf, n, qbuf, T_PTR)))
+		return (NULL);	/* h_errno was set by getanswer() */
+#ifdef SUNSECURITY
+	if (af == AF_INET) {
+	    /*
+	     * turn off search as the name should be absolute,
+	     * 'localhost' should be matched by defnames
+	     */
+	    strncpy(hname2, hp->h_name, MAXDNAME);
+	    hname2[MAXDNAME] = '\0';
+	    old_options = _res.options;
+	    _res.options &= ~RES_DNSRCH;
+	    _res.options |= RES_DEFNAMES;
+	    if (!(rhp = gethostbyname(hname2))) {
+		syslog(LOG_NOTICE|LOG_AUTH,
+		       "gethostbyaddr: No A record for %s (verifying [%s])",
+		       hname2, inet_ntoa(*((struct in_addr *)addr)));
+		_res.options = old_options;
+		h_errno = HOST_NOT_FOUND;
+		return (NULL);
+	    }
+	    _res.options = old_options;
+	    for (haddr = rhp->h_addr_list; *haddr; haddr++)
+		if (!memcmp(*haddr, addr, INADDRSZ))
+			break;
+	    if (!*haddr) {
+		syslog(LOG_NOTICE|LOG_AUTH,
+		       "gethostbyaddr: A record of %s != PTR record [%s]",
+		       hname2, inet_ntoa(*((struct in_addr *)addr)));
+		h_errno = HOST_NOT_FOUND;
+		return (NULL);
+	    }
+	}
+#endif /*SUNSECURITY*/
+	hp->h_addrtype = af;
+	hp->h_length = len;
+	bcopy(addr, host_addr, len);
+	h_addr_ptrs[0] = (char *)host_addr;
+	h_addr_ptrs[1] = NULL;
+	if (af == AF_INET && (_res.options & RES_USE_INET6)) {
+		map_v4v6_address((char*)host_addr, (char*)host_addr);
+		hp->h_addrtype = AF_INET6;
+		hp->h_length = IN6ADDRSZ;
+	}
+	h_errno = NETDB_SUCCESS;
+	return (hp);
+}
+
+void
+_sethtent(f)
+	int f;
+{
+	if (!hostf)
+		hostf = fopen(_PATH_HOSTS, "r" );
+	else
+		rewind(hostf);
+	stayopen = f;
+}
+
+void
+_endhtent()
+{
+	if (hostf && !stayopen) {
+		(void) fclose(hostf);
+		hostf = NULL;
+	}
+}
+
+struct hostent *
+_gethtent()
+{
+	char *p;
+	register char *cp, **q;
+	int af, len;
+
+	if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+ again:
+	if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
+		h_errno = HOST_NOT_FOUND;
+		return (NULL);
+	}
+	if (*p == '#')
+		goto again;
+	if (!(cp = strpbrk(p, "#\n")))
+		goto again;
+	*cp = '\0';
+	if (!(cp = strpbrk(p, " \t")))
+		goto again;
+	*cp++ = '\0';
+	if ((_res.options & RES_USE_INET6) &&
+	    inet_pton(AF_INET6, p, host_addr) > 0) {
+		af = AF_INET6;
+		len = IN6ADDRSZ;
+	} else if (inet_pton(AF_INET, p, host_addr) > 0) {
+		if (_res.options & RES_USE_INET6) {
+			map_v4v6_address((char*)host_addr, (char*)host_addr);
+			af = AF_INET6;
+			len = IN6ADDRSZ;
+		} else {
+			af = AF_INET;
+			len = INADDRSZ;
+		}
+	} else {
+		goto again;
+	}
+	h_addr_ptrs[0] = (char *)host_addr;
+	h_addr_ptrs[1] = NULL;
+	host.h_addr_list = h_addr_ptrs;
+	host.h_length = len;
+	host.h_addrtype = af;
+	while (*cp == ' ' || *cp == '\t')
+		cp++;
+	host.h_name = cp;
+	q = host.h_aliases = host_aliases;
+	if (cp = strpbrk(cp, " \t"))
+		*cp++ = '\0';
+	while (cp && *cp) {
+		if (*cp == ' ' || *cp == '\t') {
+			cp++;
+			continue;
+		}
+		if (q < &host_aliases[MAXALIASES - 1])
+			*q++ = cp;
+		if (cp = strpbrk(cp, " \t"))
+			*cp++ = '\0';
+	}
+	*q = NULL;
+	if (_res.options & RES_USE_INET6) {
+		char *bp = hostbuf;
+		int buflen = sizeof hostbuf;
+
+		map_v4v6_hostent(&host, &bp, &buflen);
+	}
+	h_errno = NETDB_SUCCESS;
+	return (&host);
+}
+
+struct hostent *
+_gethtbyname(name)
+	const char *name;
+{
+	extern struct hostent *_gethtbyname2();
+	struct hostent *hp;
+
+	if (_res.options & RES_USE_INET6) {
+		hp = _gethtbyname2(name, AF_INET6);
+		if (hp)
+			return (hp);
+	}
+	return (_gethtbyname2(name, AF_INET));
+}
+
+struct hostent *
+_gethtbyname2(name, af)
+	const char *name;
+	int af;
+{
+	register struct hostent *p;
+	register char **cp;
+	
+	_sethtent(0);
+	while (p = _gethtent()) {
+		if (p->h_addrtype != af)
+			continue;
+		if (strcasecmp(p->h_name, name) == 0)
+			break;
+		for (cp = p->h_aliases; *cp != 0; cp++)
+			if (strcasecmp(*cp, name) == 0)
+				goto found;
+	}
+ found:
+	_endhtent();
+	return (p);
+}
+
+struct hostent *
+_gethtbyaddr(addr, len, af)
+	const char *addr;
+	int len, af;
+{
+	register struct hostent *p;
+
+	_sethtent(0);
+	while (p = _gethtent())
+		if (p->h_addrtype == af && !bcmp(p->h_addr, addr, len))
+			break;
+	_endhtent();
+	return (p);
+}
+
+static void
+map_v4v6_address(src, dst)
+	const char *src;
+	char *dst;
+{
+	u_char *p = (u_char *)dst;
+	char tmp[INADDRSZ];
+	int i;
+
+	/* Stash a temporary copy so our caller can update in place. */
+	bcopy(src, tmp, INADDRSZ);
+	/* Mark this ipv6 addr as a mapped ipv4. */
+	for (i = 0; i < 10; i++)
+		*p++ = 0x00;
+	*p++ = 0xff;
+	*p++ = 0xff;
+	/* Retrieve the saved copy and we're done. */
+	bcopy(tmp, (void*)p, INADDRSZ);
+}
+
+static void
+map_v4v6_hostent(hp, bpp, lenp)
+	struct hostent *hp;
+	char **bpp;
+	int *lenp;
+{
+	char **ap;
+
+	if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
+		return;
+	hp->h_addrtype = AF_INET6;
+	hp->h_length = IN6ADDRSZ;
+	for (ap = hp->h_addr_list; *ap; ap++) {
+		int i = sizeof(align) - ((u_long)*bpp % sizeof(align));
+
+		if (*lenp < (i + IN6ADDRSZ)) {
+			/* Out of memory.  Truncate address list here.  XXX */
+			*ap = NULL;
+			return;
+		}
+		*bpp += i;
+		*lenp -= i;
+		map_v4v6_address(*ap, *bpp);
+		*ap = *bpp;
+		*bpp += IN6ADDRSZ;
+		*lenp -= IN6ADDRSZ;
+	}
+}
+
+#ifdef RESOLVSORT
+static void
+addrsort(ap, num)
+	char **ap;
+	int num;
+{
+	int i, j;
+	char **p;
+	short aval[MAXADDRS];
+	int needsort = 0;
+
+	p = ap;
+	for (i = 0; i < num; i++, p++) {
+	    for (j = 0 ; (unsigned)j < _res.nsort; j++)
+		if (_res.sort_list[j].addr.s_addr == 
+		    (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask))
+			break;
+	    aval[i] = j;
+	    if (needsort == 0 && i > 0 && j < aval[i-1])
+		needsort = i;
+	}
+	if (!needsort)
+	    return;
+
+	while (needsort < num) {
+	    for (j = needsort - 1; j >= 0; j--) {
+		if (aval[j] > aval[j+1]) {
+		    char *hp;
+
+		    i = aval[j];
+		    aval[j] = aval[j+1];
+		    aval[j+1] = i;
+
+		    hp = ap[j];
+		    ap[j] = ap[j+1];
+		    ap[j+1] = hp;
+
+		} else
+		    break;
+	    }
+	    needsort++;
+	}
+}
+#endif
+
+#if defined(BSD43_BSD43_NFS) || defined(sun)
+/* some libc's out there are bound internally to these names (UMIPS) */
+void
+ht_sethostent(stayopen)
+	int stayopen;
+{
+	_sethtent(stayopen);
+}
+
+void
+ht_endhostent()
+{
+	_endhtent();
+}
+
+struct hostent *
+ht_gethostbyname(name)
+	char *name;
+{
+	return (_gethtbyname(name));
+}
+
+struct hostent *
+ht_gethostbyaddr(addr, len, af)
+	const char *addr;
+	int len, af;
+{
+	return (_gethtbyaddr(addr, len, af));
+}
+
+struct hostent *
+gethostent()
+{
+	return (_gethtent());
+}
+
+void
+dns_service()
+{
+	return;
+}
+
+#undef dn_skipname
+dn_skipname(comp_dn, eom)
+	const u_char *comp_dn, *eom;
+{
+	return (__dn_skipname(comp_dn, eom));
+}
+#endif /*old-style libc with yp junk in it*/