initial import

1 files changed, 746 insertions, 0 deletions

diff --git a/resolv/res_send.c b/resolv/res_send.c
new file mode 100644
index 0000000..03055d3
--- /dev/null
+++ b/resolv/res_send.c
@@ -0,0 +1,746 @@
+/*
+ * ++Copyright++ 1985, 1989, 1993
+ * -
+ * Copyright (c) 1985, 1989, 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)
+static char sccsid[] = "@(#)res_send.c	8.1 (Berkeley) 6/4/93";
+static char rcsid[] = "$Id$";
+#endif /* LIBC_SCCS and not lint */
+
+	/* change this to "0"
+	 * if you talk to a lot
+	 * of multi-homed SunOS
+	 * ("broken") name servers.
+	 */
+#define	CHECK_SRVR_ADDR	1	/* XXX - should be in options.h */
+
+/*
+ * Send query to name server and wait for reply.
+ */
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <arpa/inet.h>
+
+#include <stdio.h>
+#include <errno.h>
+#include <resolv.h>
+#if defined(BSD) && (BSD >= 199306)
+# include <stdlib.h>
+# include <string.h>
+#else
+# include "../conf/portability.h"
+#endif
+
+#if defined(USE_OPTIONS_H)
+# include <../conf/options.h>
+#endif
+
+void _res_close __P((void));
+
+static int s = -1;	/* socket used for communications */
+static int connected = 0;	/* is the socket connected */
+static int vc = 0;	/* is the socket a virtual ciruit? */
+
+#ifndef FD_SET
+/* XXX - should be in portability.h */
+#define	NFDBITS		32
+#define	FD_SETSIZE	32
+#define	FD_SET(n, p)	((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
+#define	FD_CLR(n, p)	((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
+#define	FD_ISSET(n, p)	((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
+#define FD_ZERO(p)	bzero((char *)(p), sizeof(*(p)))
+#endif
+
+#ifndef DEBUG
+#   define Dprint(cond, args) /*empty*/
+#   define DprintQ(cond, args, query) /*empty*/
+#   define Aerror(file, string, error, address) /*empty*/
+#   define Perror(file, string, error) /*empty*/
+#else
+#   define Dprint(cond, args) if (cond) {fprintf args;} else {}
+#   define DprintQ(cond, args, query) if (cond) {\
+			fprintf args;\
+			__p_query(query);\
+		} else {}
+    static void
+    Aerror(file, string, error, address)
+	FILE *file;
+	char *string;
+	int error;
+	struct sockaddr_in address;
+    {
+	int save = errno;
+
+	if (_res.options & RES_DEBUG) {
+		fprintf(file, "res_send: %s ([%s].%u): %s\n",
+			string,
+			inet_ntoa(address.sin_addr),
+			ntohs(address.sin_port),
+			strerror(error));
+	}
+	errno = save;
+    }
+    static void
+    Perror(file, string, error)
+	FILE *file;
+	char *string;
+	int error;
+    {
+	int save = errno;
+
+	if (_res.options & RES_DEBUG) {
+		fprintf(file, "res_send: %s: %s\n",
+			string, strerror(error));
+	}
+	errno = save;
+    }
+#endif
+
+static res_send_qhook Qhook = NULL;
+static res_send_rhook Rhook = NULL;
+
+void
+res_send_setqhook(hook)
+	res_send_qhook hook;
+{
+
+	Qhook = hook;
+}
+
+void
+res_send_setrhook(hook)
+	res_send_rhook hook;
+{
+
+	Rhook = hook;
+}
+
+/* int
+ * res_isourserver(ina)
+ *	looks up "ina" in _res.ns_addr_list[]
+ * returns:
+ *	0  : not found
+ *	>0 : found
+ * author:
+ *	paul vixie, 29may94
+ */
+int
+res_isourserver(inp)
+	const struct sockaddr_in *inp;
+{
+	struct sockaddr_in ina;
+	register int ns, ret;
+
+	ina = *inp;
+	ret = 0;
+	for (ns = 0;  ns < _res.nscount;  ns++) {
+		register const struct sockaddr_in *srv = &_res.nsaddr_list[ns];
+
+		if (srv->sin_family == ina.sin_family &&
+		    srv->sin_port == ina.sin_port &&
+		    (srv->sin_addr.s_addr == INADDR_ANY ||
+		     srv->sin_addr.s_addr == ina.sin_addr.s_addr)) {
+			ret++;
+			break;
+		}
+	}
+	return (ret);
+}
+
+/* int
+ * res_nameinquery(name, type, class, buf, eom)
+ *	look for (name,type,class) in the query section of packet (buf,eom)
+ * returns:
+ *	-1 : format error
+ *	0  : not found
+ *	>0 : found
+ * author:
+ *	paul vixie, 29may94
+ */
+int
+res_nameinquery(name, type, class, buf, eom)
+	const char *name;
+	register int type, class;
+	const u_char *buf, *eom;
+{
+	register const u_char *cp = buf + HFIXEDSZ;
+	int qdcount = ntohs(((HEADER*)buf)->qdcount);
+
+	while (qdcount-- > 0) {
+		char tname[MAXDNAME+1];
+		register int n, ttype, tclass;
+
+		n = dn_expand(buf, eom, cp, tname, sizeof tname);
+		if (n < 0)
+			return (-1);
+		cp += n;
+		ttype = _getshort(cp);	cp += INT16SZ;
+		tclass = _getshort(cp); cp += INT16SZ;
+		if (ttype == type &&
+		    tclass == class &&
+		    strcasecmp(tname, name) == 0)
+			return (1);
+	}
+	return (0);
+}
+
+/* int
+ * res_queriesmatch(buf1, eom1, buf2, eom2)
+ *	is there a 1:1 mapping of (name,type,class)
+ *	in (buf1,eom1) and (buf2,eom2)?
+ * returns:
+ *	-1 : format error
+ *	0  : not a 1:1 mapping
+ *	>0 : is a 1:1 mapping
+ * author:
+ *	paul vixie, 29may94
+ */
+int
+res_queriesmatch(buf1, eom1, buf2, eom2)
+	const u_char *buf1, *eom1;
+	const u_char *buf2, *eom2;
+{
+	register const u_char *cp = buf1 + HFIXEDSZ;
+	int qdcount = ntohs(((HEADER*)buf1)->qdcount);
+
+	if (qdcount != ntohs(((HEADER*)buf2)->qdcount))
+		return (0);
+	while (qdcount-- > 0) {
+		char tname[MAXDNAME+1];
+		register int n, ttype, tclass;
+
+		n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
+		if (n < 0)
+			return (-1);
+		cp += n;
+		ttype = _getshort(cp);	cp += INT16SZ;
+		tclass = _getshort(cp); cp += INT16SZ;
+		if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
+			return (0);
+	}
+	return (1);
+}
+
+int
+res_send(buf, buflen, ans, anssiz)
+	const u_char *buf;
+	int buflen;
+	u_char *ans;
+	int anssiz;
+{
+	HEADER *hp = (HEADER *) buf;
+	HEADER *anhp = (HEADER *) ans;
+	int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns;
+	register int n;
+	u_int badns;	/* XXX NSMAX can't exceed #/bits in this var */
+
+	DprintQ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY),
+		(stdout, ";; res_send()\n"), buf);
+	if (!(_res.options & RES_INIT) && res_init() == -1)
+		return (-1);
+	v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
+	gotsomewhere = 0;
+	connreset = 0;
+	terrno = ETIMEDOUT;
+	badns = 0;
+
+	/*
+	 * Send request, RETRY times, or until successful
+	 */
+	for (try = 0; try < _res.retry; try++) {
+	    for (ns = 0; ns < _res.nscount; ns++) {
+		struct sockaddr_in *nsap = &_res.nsaddr_list[ns];
+    same_ns:
+		if (badns & (1 << ns)) {
+			_res_close();
+			goto next_ns;
+		}
+
+		if (Qhook) {
+			int done = 0, loops = 0;
+
+			do {
+				res_sendhookact act;
+
+				act = (*Qhook)(&nsap, &buf, &buflen,
+					       ans, anssiz, &resplen);
+				switch (act) {
+				case res_goahead:
+					done = 1;
+					break;
+				case res_nextns:
+					_res_close();
+					goto next_ns;
+				case res_done:
+					return (resplen);
+				case res_modified:
+					/* give the hook another try */
+					if (++loops < 42) /*doug adams*/
+						break;
+					/*FALLTHROUGH*/
+				case res_error:
+					/*FALLTHROUGH*/
+				default:
+					return (-1);
+				}
+			} while (!done);
+		}
+
+		Dprint(_res.options & RES_DEBUG,
+		       (stdout, ";; Querying server (# %d) address = %s\n",
+			ns + 1, inet_ntoa(nsap->sin_addr)));
+
+		if (v_circuit) {
+			int truncated;
+			struct iovec iov[2];
+			u_short len;
+			u_char *cp;
+
+			/*
+			 * Use virtual circuit;
+			 * at most one attempt per server.
+			 */
+			try = _res.retry;
+			truncated = 0;
+			if ((s < 0) || (!vc)) {
+				if (s >= 0)
+					_res_close();
+
+				s = socket(AF_INET, SOCK_STREAM, PF_UNSPEC);
+				if (s < 0) {
+					terrno = errno;
+					Perror(stderr, "socket(vc)", errno);
+					return (-1);
+				}
+				if (connect(s, (struct sockaddr *)nsap,
+					    sizeof(struct sockaddr)) < 0) {
+					terrno = errno;
+					Aerror(stderr, "connect/vc",
+					       errno, *nsap);
+					badns |= (1 << ns);
+					_res_close();
+					goto next_ns;
+				}
+				vc = 1;
+			}
+			/*
+			 * Send length & message
+			 */
+			putshort((u_short)buflen, (u_char*)&len);
+			iov[0].iov_base = (caddr_t)&len;
+			iov[0].iov_len = INT16SZ;
+			iov[1].iov_base = (caddr_t)buf;
+			iov[1].iov_len = buflen;
+			if (writev(s, iov, 2) != (INT16SZ + buflen)) {
+				terrno = errno;
+				Perror(stderr, "write failed", errno);
+				badns |= (1 << ns);
+				_res_close();
+				goto next_ns;
+			}
+			/*
+			 * Receive length & response
+			 */
+			cp = ans;
+			len = INT16SZ;
+			while ((n = read(s, (char *)cp, (int)len)) > 0) {
+				cp += n;
+				if ((len -= n) <= 0)
+					break;
+			}
+			if (n <= 0) {
+				terrno = errno;
+				Perror(stderr, "read failed", errno);
+				_res_close();
+				/*
+				 * A long running process might get its TCP
+				 * connection reset if the remote server was
+				 * restarted.  Requery the server instead of
+				 * trying a new one.  When there is only one
+				 * server, this means that a query might work
+				 * instead of failing.  We only allow one reset
+				 * per query to prevent looping.
+				 */
+				if (terrno == ECONNRESET && !connreset) {
+					connreset = 1;
+					_res_close();
+					goto same_ns;
+				}
+				_res_close();
+				goto next_ns;
+			}
+			resplen = _getshort(ans);
+			if (resplen > anssiz) {
+				Dprint(_res.options & RES_DEBUG,
+				       (stdout, ";; response truncated\n")
+				       );
+				truncated = 1;
+				len = anssiz;
+			} else
+				len = resplen;
+			cp = ans;
+			while (len != 0 &&
+			       (n = read(s, (char *)cp, (int)len)) > 0) {
+				cp += n;
+				len -= n;
+			}
+			if (n <= 0) {
+				terrno = errno;
+				Perror(stderr, "read(vc)", errno);
+				_res_close();
+				goto next_ns;
+			}
+			if (truncated) {
+				/*
+				 * Flush rest of answer
+				 * so connection stays in synch.
+				 */
+				anhp->tc = 1;
+				len = resplen - anssiz;
+				while (len != 0) {
+					char junk[PACKETSZ];
+
+					n = (len > sizeof(junk)
+					     ? sizeof(junk)
+					     : len);
+					if ((n = read(s, junk, n)) > 0)
+						len -= n;
+					else
+						break;
+				}
+			}
+		} else {
+			/*
+			 * Use datagrams.
+			 */
+			struct timeval timeout;
+			fd_set dsmask;
+			struct sockaddr_in from;
+			int fromlen;
+
+			if ((s < 0) || vc) {
+				if (vc)
+					_res_close();
+				s = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC);
+				if (s < 0) {
+ bad_dg_sock:				terrno = errno;
+					Perror(stderr, "socket(dg)", errno);
+					return (-1);
+				}
+				connected = 0;
+			}
+			/*
+			 * On a 4.3BSD+ machine (client and server,
+			 * actually), sending to a nameserver datagram
+			 * port with no nameserver will cause an
+			 * ICMP port unreachable message to be returned.
+			 * If our datagram socket is "connected" to the
+			 * server, we get an ECONNREFUSED error on the next
+			 * socket operation, and select returns if the
+			 * error message is received.  We can thus detect
+			 * the absence of a nameserver without timing out.
+			 * If we have sent queries to at least two servers,
+			 * however, we don't want to remain connected,
+			 * as we wish to receive answers from the first
+			 * server to respond.
+			 */
+			if (_res.nscount == 1 || (try == 0 && ns == 0)) {
+				/*
+				 * Connect only if we are sure we won't
+				 * receive a response from another server.
+				 */
+				if (!connected) {
+					if (connect(s, (struct sockaddr *)nsap,
+						    sizeof(struct sockaddr)
+						    ) < 0) {
+						Aerror(stderr,
+						       "connect(dg)",
+						       errno, *nsap);
+						badns |= (1 << ns);
+						_res_close();
+						goto next_ns;
+					}
+					connected = 1;
+				}
+				if (send(s, (char*)buf, buflen, 0) != buflen) {
+					Perror(stderr, "send", errno);
+					badns |= (1 << ns);
+					_res_close();
+					goto next_ns;
+				}
+			} else {
+				/*
+				 * Disconnect if we want to listen
+				 * for responses from more than one server.
+				 */
+				if (connected) {
+#if defined(BSD) && (BSD >= 199103)
+					struct sockaddr_in no_addr;
+
+					no_addr.sin_family = AF_INET;
+					no_addr.sin_addr.s_addr = INADDR_ANY;
+					no_addr.sin_port = 0;
+					(void) connect(s,
+						       (struct sockaddr *)
+						        &no_addr,
+						       sizeof(no_addr));
+#else
+					int s1 = socket(AF_INET, SOCK_DGRAM,
+							PF_UNSPEC);
+					if (s1 < 0)
+						goto bad_dg_sock;
+					(void) dup2(s1, s);
+					(void) close(s1);
+					Dprint(_res.options & RES_DEBUG,
+					       (stdout, ";; new DG socket\n"))
+#endif
+					connected = 0;
+					errno = 0;
+				}
+				if (sendto(s, (char*)buf, buflen, 0,
+					   (struct sockaddr *)nsap,
+					   sizeof(struct sockaddr))
+				    != buflen) {
+					Aerror(stderr, "sendto", errno, *nsap);
+					badns |= (1 << ns);
+					_res_close();
+					goto next_ns;
+				}
+			}
+
+			/*
+			 * Wait for reply
+			 */
+			timeout.tv_sec = (_res.retrans << try);
+			if (try > 0)
+				timeout.tv_sec /= _res.nscount;
+			if ((long) timeout.tv_sec <= 0)
+				timeout.tv_sec = 1;
+			timeout.tv_usec = 0;
+    wait:
+			FD_ZERO(&dsmask);
+			FD_SET(s, &dsmask);
+			n = select(s+1, &dsmask, (fd_set *)NULL,
+				   (fd_set *)NULL, &timeout);
+			if (n < 0) {
+				Perror(stderr, "select", errno);
+				_res_close();
+				goto next_ns;
+			}
+			if (n == 0) {
+				/*
+				 * timeout
+				 */
+				Dprint(_res.options & RES_DEBUG,
+				       (stdout, ";; timeout\n"));
+				gotsomewhere = 1;
+				_res_close();
+				goto next_ns;
+			}
+			fromlen = sizeof(struct sockaddr_in);
+			resplen = recvfrom(s, (char*)ans, anssiz, 0,
+					   (struct sockaddr *)&from, &fromlen);
+			if (resplen <= 0) {
+				Perror(stderr, "recvfrom", errno);
+				_res_close();
+				goto next_ns;
+			}
+			gotsomewhere = 1;
+			if (hp->id != anhp->id) {
+				/*
+				 * response from old query, ignore it.
+				 * XXX - potential security hazard could
+				 *	 be detected here.
+				 */
+				DprintQ((_res.options & RES_DEBUG) ||
+					(_res.pfcode & RES_PRF_REPLY),
+					(stdout, ";; old answer:\n"),
+					ans);
+				goto wait;
+			}
+#if CHECK_SRVR_ADDR
+			if (!(_res.options & RES_INSECURE1) &&
+			    !res_isourserver(&from)) {
+				/*
+				 * response from wrong server? ignore it.
+				 * XXX - potential security hazard could
+				 *	 be detected here.
+				 */
+				DprintQ((_res.options & RES_DEBUG) ||
+					(_res.pfcode & RES_PRF_REPLY),
+					(stdout, ";; not our server:\n"),
+					ans);
+				goto wait;
+			}
+#endif
+			if (!(_res.options & RES_INSECURE2) &&
+			    !res_queriesmatch(buf, buf + buflen,
+					      ans, ans + anssiz)) {
+				/*
+				 * response contains wrong query? ignore it.
+				 * XXX - potential security hazard could
+				 *	 be detected here.
+				 */
+				DprintQ((_res.options & RES_DEBUG) ||
+					(_res.pfcode & RES_PRF_REPLY),
+					(stdout, ";; wrong query name:\n"),
+					ans);
+				goto wait;
+			}
+			if (anhp->rcode == SERVFAIL ||
+			    anhp->rcode == NOTIMP ||
+			    anhp->rcode == REFUSED) {
+				DprintQ(_res.options & RES_DEBUG,
+					(stdout, "server rejected query:\n"),
+					ans);
+				badns |= (1 << ns);
+				_res_close();
+				/* don't retry if called from dig */
+				if (!_res.pfcode)
+					goto next_ns;
+			}
+			if (!(_res.options & RES_IGNTC) && anhp->tc) {
+				/*
+				 * get rest of answer;
+				 * use TCP with same server.
+				 */
+				Dprint(_res.options & RES_DEBUG,
+				       (stdout, ";; truncated answer\n"));
+				v_circuit = 1;
+				_res_close();
+				goto same_ns;
+			}
+		} /*if vc/dg*/
+		DprintQ((_res.options & RES_DEBUG) ||
+			(_res.pfcode & RES_PRF_REPLY),
+			(stdout, ";; got answer:\n"),
+			ans);
+		/*
+		 * If using virtual circuits, we assume that the first server
+		 * is preferred over the rest (i.e. it is on the local
+		 * machine) and only keep that one open.
+		 * If we have temporarily opened a virtual circuit,
+		 * or if we haven't been asked to keep a socket open,
+		 * close the socket.
+		 */
+		if ((v_circuit && (!(_res.options & RES_USEVC) || ns != 0)) ||
+		    !(_res.options & RES_STAYOPEN)) {
+			_res_close();
+		}
+		if (Rhook) {
+			int done = 0, loops = 0;
+
+			do {
+				res_sendhookact act;
+
+				act = (*Rhook)(nsap, buf, buflen,
+					       ans, anssiz, &resplen);
+				switch (act) {
+				case res_goahead:
+				case res_done:
+					done = 1;
+					break;
+				case res_nextns:
+					_res_close();
+					goto next_ns;
+				case res_modified:
+					/* give the hook another try */
+					if (++loops < 42) /*doug adams*/
+						break;
+					/*FALLTHROUGH*/
+				case res_error:
+					/*FALLTHROUGH*/
+				default:
+					return (-1);
+				}
+			} while (!done);
+
+		}
+		return (resplen);
+    next_ns: ;
+	   } /*foreach ns*/
+	} /*foreach retry*/
+	_res_close();
+	if (!v_circuit)
+		if (!gotsomewhere)
+			errno = ECONNREFUSED;	/* no nameservers found */
+		else
+			errno = ETIMEDOUT;	/* no answer obtained */
+	else
+		errno = terrno;
+	return (-1);
+}
+
+/*
+ * This routine is for closing the socket if a virtual circuit is used and
+ * the program wants to close it.  This provides support for endhostent()
+ * which expects to close the socket.
+ *
+ * This routine is not expected to be user visible.
+ */
+void
+_res_close()
+{
+	if (s >= 0) {
+		(void) close(s);
+		s = -1;
+		connected = 0;
+		vc = 0;
+	}
+}