res_send.c

bind 9.3结合mysql数据库

/*
 * 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 (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (c) 1996-1999 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 ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char sccsid[] = "@(#)res_send.c	8.1 (Berkeley) 6/4/93";
static const char rcsid[] = "$Id: res_send.c,v 1.5.2.2.4.5 2004/08/10 02:19:56 marka Exp $";
#endif /* LIBC_SCCS and not lint */

/*
 * Send query to name server and wait for reply.
 */

#include "port_before.h"
#include "fd_setsize.h"

#include <sys/types.h>
#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 <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <isc/eventlib.h>

#include "port_after.h"

/* Options.  Leave them on. */
#define DEBUG
#include "res_debug.h"
#include "res_private.h"

#define EXT(res) ((res)->_u._ext)

static const int highestFD = FD_SETSIZE - 1;

/* Forward. */

static int		get_salen __P((const struct sockaddr *));
static struct sockaddr * get_nsaddr __P((res_state, size_t));
static int		send_vc(res_state, const u_char *, int,
				u_char *, int, int *, int);
static int		send_dg(res_state, const u_char *, int,
				u_char *, int, int *, int,
				int *, int *);
static void		Aerror(const res_state, FILE *, const char *, int,
			       const struct sockaddr *, int);
static void		Perror(const res_state, FILE *, const char *, int);
static int		sock_eq(struct sockaddr *, struct sockaddr *);
#ifdef NEED_PSELECT
static int		pselect(int, void *, void *, void *,
				struct timespec *,
				const sigset_t *);
#endif
void res_pquery(const res_state, const u_char *, int, FILE *);

static const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;

/* Public. */

/* int
 * res_isourserver(ina)
 *	looks up "ina" in _res.ns_addr_list[]
 * returns:
 *	0  : not found
 *	>0 : found
 * author:
 *	paul vixie, 29may94
 */
int
res_ourserver_p(const res_state statp, const struct sockaddr *sa) {
	const struct sockaddr_in *inp, *srv;
	const struct sockaddr_in6 *in6p, *srv6;
	int ns;

	switch (sa->sa_family) {
	case AF_INET:
		inp = (const struct sockaddr_in *)sa;
		for (ns = 0;  ns < statp->nscount;  ns++) {
			srv = (struct sockaddr_in *)get_nsaddr(statp, ns);
			if (srv->sin_family == inp->sin_family &&
			    srv->sin_port == inp->sin_port &&
			    (srv->sin_addr.s_addr == INADDR_ANY ||
			     srv->sin_addr.s_addr == inp->sin_addr.s_addr))
				return (1);
		}
		break;
	case AF_INET6:
		if (EXT(statp).ext == NULL)
			break;
		in6p = (const struct sockaddr_in6 *)sa;
		for (ns = 0;  ns < statp->nscount;  ns++) {
			srv6 = (struct sockaddr_in6 *)get_nsaddr(statp, ns);
			if (srv6->sin6_family == in6p->sin6_family &&
			    srv6->sin6_port == in6p->sin6_port &&
#ifdef HAVE_SIN6_SCOPE_ID
			    (srv6->sin6_scope_id == 0 ||
			     srv6->sin6_scope_id == in6p->sin6_scope_id) &&
#endif
			    (IN6_IS_ADDR_UNSPECIFIED(&srv6->sin6_addr) ||
			     IN6_ARE_ADDR_EQUAL(&srv6->sin6_addr, &in6p->sin6_addr)))
				return (1);
		}
		break;
	default:
		break;
	}
	return (0);
}

/* int
 * res_nameinquery(name, type, class, buf, eom)
 *	look for (name,type,class) in the query section of packet (buf,eom)
 * requires:
 *	buf + HFIXEDSZ <= eom
 * returns:
 *	-1 : format error
 *	0  : not found
 *	>0 : found
 * author:
 *	paul vixie, 29may94
 */
int
res_nameinquery(const char *name, int type, int class,
		const u_char *buf, const u_char *eom)
{
	const u_char *cp = buf + HFIXEDSZ;
	int qdcount = ntohs(((const HEADER*)buf)->qdcount);

	while (qdcount-- > 0) {
		char tname[MAXDNAME+1];
		int n, ttype, tclass;

		n = dn_expand(buf, eom, cp, tname, sizeof tname);
		if (n < 0)
			return (-1);
		cp += n;
		if (cp + 2 * INT16SZ > eom)
			return (-1);
		ttype = ns_get16(cp); cp += INT16SZ;
		tclass = ns_get16(cp); cp += INT16SZ;
		if (ttype == type && tclass == class &&
		    ns_samename(tname, name) == 1)
			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(const u_char *buf1, const u_char *eom1,
		 const u_char *buf2, const u_char *eom2)
{
	const u_char *cp = buf1 + HFIXEDSZ;
	int qdcount = ntohs(((const HEADER*)buf1)->qdcount);

	if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
		return (-1);

	/*
	 * Only header section present in replies to
	 * dynamic update packets.
	 */
	if ((((const HEADER *)buf1)->opcode == ns_o_update) &&
	    (((const HEADER *)buf2)->opcode == ns_o_update))
		return (1);

	if (qdcount != ntohs(((const HEADER*)buf2)->qdcount))
		return (0);
	while (qdcount-- > 0) {
		char tname[MAXDNAME+1];
		int n, ttype, tclass;

		n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
		if (n < 0)
			return (-1);
		cp += n;
		if (cp + 2 * INT16SZ > eom1)
			return (-1);
		ttype = ns_get16(cp);	cp += INT16SZ;
		tclass = ns_get16(cp); cp += INT16SZ;
		if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
			return (0);
	}
	return (1);
}

int
res_nsend(res_state statp,
	  const u_char *buf, int buflen, u_char *ans, int anssiz)
{
	int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
	char abuf[NI_MAXHOST];

	if (statp->nscount == 0) {
		errno = ESRCH;
		return (-1);
	}
	if (anssiz < HFIXEDSZ) {
		errno = EINVAL;
		return (-1);
	}
	DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
		(stdout, ";; res_send()\n"), buf, buflen);
	v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
	gotsomewhere = 0;
	terrno = ETIMEDOUT;

	/*
	 * If the ns_addr_list in the resolver context has changed, then
	 * invalidate our cached copy and the associated timing data.
	 */
	if (EXT(statp).nscount != 0) {
		int needclose = 0;
		struct sockaddr_storage peer;
		ISC_SOCKLEN_T peerlen;

		if (EXT(statp).nscount != statp->nscount)
			needclose++;
		else
			for (ns = 0; ns < statp->nscount; ns++) {
				if (statp->nsaddr_list[ns].sin_family &&
				    !sock_eq((struct sockaddr *)&statp->nsaddr_list[ns],
					     (struct sockaddr *)&EXT(statp).ext->nsaddrs[ns])) {
					needclose++;
					break;
				}

				if (EXT(statp).nssocks[ns] == -1)
					continue;
				peerlen = sizeof(peer);
				if (getsockname(EXT(statp).nssocks[ns],
				    (struct sockaddr *)&peer, &peerlen) < 0) {
					needclose++;
					break;
				}
				if (!sock_eq((struct sockaddr *)&peer,
				    get_nsaddr(statp, ns))) {
					needclose++;
					break;
				}
			}
		if (needclose) {
			res_nclose(statp);
			EXT(statp).nscount = 0;
		}
	}

	/*
	 * Maybe initialize our private copy of the ns_addr_list.
	 */
	if (EXT(statp).nscount == 0) {
		for (ns = 0; ns < statp->nscount; ns++) {
			EXT(statp).nstimes[ns] = RES_MAXTIME;
			EXT(statp).nssocks[ns] = -1;
			if (!statp->nsaddr_list[ns].sin_family)
				continue;
			EXT(statp).ext->nsaddrs[ns].sin =
				 statp->nsaddr_list[ns];
		}
		EXT(statp).nscount = statp->nscount;
	}

	/*
	 * Some resolvers want to even out the load on their nameservers.
	 * Note that RES_BLAST overrides RES_ROTATE.
	 */
	if ((statp->options & RES_ROTATE) != 0U &&
	    (statp->options & RES_BLAST) == 0U) {
		union res_sockaddr_union inu;
		struct sockaddr_in ina;
		int lastns = statp->nscount - 1;
		int fd;
		u_int16_t nstime;

		if (EXT(statp).ext != NULL)
			inu = EXT(statp).ext->nsaddrs[0];
		ina = statp->nsaddr_list[0];
		fd = EXT(statp).nssocks[0];
		nstime = EXT(statp).nstimes[0];
		for (ns = 0; ns < lastns; ns++) {
			if (EXT(statp).ext != NULL)
                                EXT(statp).ext->nsaddrs[ns] = 
					EXT(statp).ext->nsaddrs[ns + 1];
			statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
			EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
			EXT(statp).nstimes[ns] = EXT(statp).nstimes[ns + 1];
		}
		if (EXT(statp).ext != NULL)
			EXT(statp).ext->nsaddrs[lastns] = inu;
		statp->nsaddr_list[lastns] = ina;
		EXT(statp).nssocks[lastns] = fd;
		EXT(statp).nstimes[lastns] = nstime;
	}

	/*
	 * Send request, RETRY times, or until successful.
	 */
	for (try = 0; try < statp->retry; try++) {
	    for (ns = 0; ns < statp->nscount; ns++) {
		struct sockaddr *nsap;
		int nsaplen;
		nsap = get_nsaddr(statp, ns);
		nsaplen = get_salen(nsap);
		statp->_flags &= ~RES_F_LASTMASK;
		statp->_flags |= (ns << RES_F_LASTSHIFT);
 same_ns:
		if (statp->qhook) {
			int done = 0, loops = 0;

			do {
				res_sendhookact act;

				act = (*statp->qhook)(&nsap, &buf, &buflen,
						      ans, anssiz, &resplen);
				switch (act) {
				case res_goahead:
					done = 1;
					break;
				case res_nextns:
					res_nclose(statp);
					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:
					goto fail;
				}
			} while (!done);
		}

		Dprint(((statp->options & RES_DEBUG) &&
			getnameinfo(nsap, nsaplen, abuf, sizeof(abuf),
				    NULL, 0, niflags) == 0),
		       (stdout, ";; Querying server (# %d) address = %s\n",
			ns + 1, abuf));


		if (v_circuit) {
			/* Use VC; at most one attempt per server. */
			try = statp->retry;
			n = send_vc(statp, buf, buflen, ans, anssiz, &terrno,
				    ns);
			if (n < 0)
				goto fail;
			if (n == 0)
				goto next_ns;
			resplen = n;
		} else {
			/* Use datagrams. */
			n = send_dg(statp, buf, buflen, ans, anssiz, &terrno,
				    ns, &v_circuit, &gotsomewhere);
			if (n < 0)
				goto fail;
			if (n == 0)
				goto next_ns;
			if (v_circuit)
				goto same_ns;
			resplen = n;
		}

		Dprint((statp->options & RES_DEBUG) ||
		       ((statp->pfcode & RES_PRF_REPLY) &&
			(statp->pfcode & RES_PRF_HEAD1)),
		       (stdout, ";; got answer:\n"));

		DprintQ((statp->options & RES_DEBUG) ||
			(statp->pfcode & RES_PRF_REPLY),
			(stdout, "%s", ""),
			ans, (resplen > anssiz) ? anssiz : resplen);

		/*
		 * 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 && (statp->options & RES_USEVC) == 0U) ||
		    (statp->options & RES_STAYOPEN) == 0U) {
			res_nclose(statp);
		}
		if (statp->rhook) {
			int done = 0, loops = 0;

			do {
				res_sendhookact act;

				act = (*statp->rhook)(nsap, buf, buflen,
						      ans, anssiz, &resplen);
				switch (act) {
				case res_goahead:
				case res_done:
					done = 1;
					break;
				case res_nextns:
					res_nclose(statp);
					goto next_ns;
				case res_modified:
					/* give the hook another try */
					if (++loops < 42) /*doug adams*/
						break;
					/*FALLTHROUGH*/
				case res_error:
					/*FALLTHROUGH*/
				default:
					goto fail;
				}
			} while (!done);

		}
		return (resplen);
 next_ns: ;
	   } /*foreach ns*/
	} /*foreach retry*/
	res_nclose(statp);
	if (!v_circuit) {
		if (!gotsomewhere)
			errno = ECONNREFUSED;	/* no nameservers found */
		else
			errno = ETIMEDOUT;	/* no answer obtained */
	} else
		errno = terrno;
	return (-1);
 fail:
	res_nclose(statp);
	return (-1);
}

/* Private */

static int
get_salen(sa)
	const struct sockaddr *sa;
{