1089 lines
28 KiB
C
1089 lines
28 KiB
C
/*
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* Copyright (c) 1985, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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*/
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/*
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* Copyright (c) 2005 by Internet Systems Consortium, Inc. ("ISC")
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* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
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* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static const char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
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static const char rcsid[] = "$Id: res_send.c,v 1.5.2.2.4.7 2005/08/15 02:04:41 marka Exp $";
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#endif /* LIBC_SCCS and not lint */
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/*
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* Send query to name server and wait for reply.
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*/
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#include "port_before.h"
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#include "fd_setsize.h"
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/time.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <netinet/in.h>
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#include <arpa/nameser.h>
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#include <arpa/inet.h>
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#include <errno.h>
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#include <netdb.h>
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#include <resolv.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <isc/eventlib.h>
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#include "port_after.h"
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#ifdef USE_POLL
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#ifdef HAVE_STROPTS_H
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#include <stropts.h>
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#endif
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#include <poll.h>
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#endif /* USE_POLL */
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/* Options. Leave them on. */
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#define DEBUG
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#include "res_debug.h"
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#include "res_private.h"
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#define EXT(res) ((res)->_u._ext)
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#ifndef USE_POLL
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static const int highestFD = FD_SETSIZE - 1;
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#else
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static int highestFD = 0;
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#endif
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/* Forward. */
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static int get_salen __P((const struct sockaddr *));
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static struct sockaddr * get_nsaddr __P((res_state, size_t));
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static int send_vc(res_state, const u_char *, int,
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u_char *, int, int *, int);
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static int send_dg(res_state, const u_char *, int,
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u_char *, int, int *, int,
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int *, int *);
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static void Aerror(const res_state, FILE *, const char *, int,
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const struct sockaddr *, int);
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static void Perror(const res_state, FILE *, const char *, int);
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static int sock_eq(struct sockaddr *, struct sockaddr *);
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#if defined(NEED_PSELECT) && !defined(USE_POLL)
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static int pselect(int, void *, void *, void *,
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struct timespec *,
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const sigset_t *);
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#endif
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void res_pquery(const res_state, const u_char *, int, FILE *);
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static const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
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/* Public. */
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/* int
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* res_isourserver(ina)
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* looks up "ina" in _res.ns_addr_list[]
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* returns:
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* 0 : not found
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* >0 : found
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* author:
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* paul vixie, 29may94
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*/
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int
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res_ourserver_p(const res_state statp, const struct sockaddr *sa) {
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const struct sockaddr_in *inp, *srv;
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const struct sockaddr_in6 *in6p, *srv6;
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int ns;
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switch (sa->sa_family) {
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case AF_INET:
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inp = (const struct sockaddr_in *)sa;
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for (ns = 0; ns < statp->nscount; ns++) {
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srv = (struct sockaddr_in *)get_nsaddr(statp, ns);
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if (srv->sin_family == inp->sin_family &&
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srv->sin_port == inp->sin_port &&
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(srv->sin_addr.s_addr == INADDR_ANY ||
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srv->sin_addr.s_addr == inp->sin_addr.s_addr))
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return (1);
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}
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break;
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case AF_INET6:
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if (EXT(statp).ext == NULL)
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break;
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in6p = (const struct sockaddr_in6 *)sa;
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for (ns = 0; ns < statp->nscount; ns++) {
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srv6 = (struct sockaddr_in6 *)get_nsaddr(statp, ns);
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if (srv6->sin6_family == in6p->sin6_family &&
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srv6->sin6_port == in6p->sin6_port &&
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#ifdef HAVE_SIN6_SCOPE_ID
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(srv6->sin6_scope_id == 0 ||
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srv6->sin6_scope_id == in6p->sin6_scope_id) &&
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#endif
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(IN6_IS_ADDR_UNSPECIFIED(&srv6->sin6_addr) ||
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IN6_ARE_ADDR_EQUAL(&srv6->sin6_addr, &in6p->sin6_addr)))
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return (1);
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}
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break;
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default:
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break;
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}
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return (0);
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}
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/* int
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* res_nameinquery(name, type, class, buf, eom)
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* look for (name,type,class) in the query section of packet (buf,eom)
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* requires:
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* buf + HFIXEDSZ <= eom
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* returns:
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* -1 : format error
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* 0 : not found
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* >0 : found
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* author:
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* paul vixie, 29may94
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*/
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int
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res_nameinquery(const char *name, int type, int class,
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const u_char *buf, const u_char *eom)
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{
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const u_char *cp = buf + HFIXEDSZ;
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int qdcount = ntohs(((const HEADER*)buf)->qdcount);
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while (qdcount-- > 0) {
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char tname[MAXDNAME+1];
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int n, ttype, tclass;
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n = dn_expand(buf, eom, cp, tname, sizeof tname);
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if (n < 0)
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return (-1);
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cp += n;
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if (cp + 2 * INT16SZ > eom)
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return (-1);
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ttype = ns_get16(cp); cp += INT16SZ;
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tclass = ns_get16(cp); cp += INT16SZ;
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if (ttype == type && tclass == class &&
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ns_samename(tname, name) == 1)
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return (1);
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}
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return (0);
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}
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/* int
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* res_queriesmatch(buf1, eom1, buf2, eom2)
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* is there a 1:1 mapping of (name,type,class)
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* in (buf1,eom1) and (buf2,eom2)?
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* returns:
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* -1 : format error
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* 0 : not a 1:1 mapping
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* >0 : is a 1:1 mapping
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* author:
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* paul vixie, 29may94
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*/
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int
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res_queriesmatch(const u_char *buf1, const u_char *eom1,
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const u_char *buf2, const u_char *eom2)
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{
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const u_char *cp = buf1 + HFIXEDSZ;
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int qdcount = ntohs(((const HEADER*)buf1)->qdcount);
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if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
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return (-1);
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/*
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* Only header section present in replies to
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* dynamic update packets.
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*/
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if ((((const HEADER *)buf1)->opcode == ns_o_update) &&
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(((const HEADER *)buf2)->opcode == ns_o_update))
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return (1);
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if (qdcount != ntohs(((const HEADER*)buf2)->qdcount))
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return (0);
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while (qdcount-- > 0) {
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char tname[MAXDNAME+1];
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int n, ttype, tclass;
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n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
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if (n < 0)
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return (-1);
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cp += n;
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if (cp + 2 * INT16SZ > eom1)
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return (-1);
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ttype = ns_get16(cp); cp += INT16SZ;
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tclass = ns_get16(cp); cp += INT16SZ;
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if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
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return (0);
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}
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return (1);
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}
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int
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res_nsend(res_state statp,
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const u_char *buf, int buflen, u_char *ans, int anssiz)
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{
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int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
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char abuf[NI_MAXHOST];
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#ifdef USE_POLL
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highestFD = sysconf(_SC_OPEN_MAX) - 1;
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#endif
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if (statp->nscount == 0) {
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errno = ESRCH;
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return (-1);
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}
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if (anssiz < HFIXEDSZ) {
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errno = EINVAL;
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return (-1);
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}
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DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
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(stdout, ";; res_send()\n"), buf, buflen);
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v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
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gotsomewhere = 0;
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terrno = ETIMEDOUT;
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/*
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* If the ns_addr_list in the resolver context has changed, then
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* invalidate our cached copy and the associated timing data.
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*/
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if (EXT(statp).nscount != 0) {
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int needclose = 0;
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struct sockaddr_storage peer;
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ISC_SOCKLEN_T peerlen;
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if (EXT(statp).nscount != statp->nscount)
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needclose++;
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else
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for (ns = 0; ns < statp->nscount; ns++) {
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if (statp->nsaddr_list[ns].sin_family &&
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!sock_eq((struct sockaddr *)&statp->nsaddr_list[ns],
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(struct sockaddr *)&EXT(statp).ext->nsaddrs[ns])) {
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needclose++;
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break;
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}
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if (EXT(statp).nssocks[ns] == -1)
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continue;
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peerlen = sizeof(peer);
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if (getsockname(EXT(statp).nssocks[ns],
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(struct sockaddr *)&peer, &peerlen) < 0) {
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needclose++;
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break;
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}
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if (!sock_eq((struct sockaddr *)&peer,
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get_nsaddr(statp, ns))) {
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needclose++;
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break;
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}
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}
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if (needclose) {
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res_nclose(statp);
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EXT(statp).nscount = 0;
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}
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}
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/*
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* Maybe initialize our private copy of the ns_addr_list.
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*/
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if (EXT(statp).nscount == 0) {
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for (ns = 0; ns < statp->nscount; ns++) {
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EXT(statp).nstimes[ns] = RES_MAXTIME;
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EXT(statp).nssocks[ns] = -1;
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if (!statp->nsaddr_list[ns].sin_family)
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continue;
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EXT(statp).ext->nsaddrs[ns].sin =
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statp->nsaddr_list[ns];
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}
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EXT(statp).nscount = statp->nscount;
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}
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|
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/*
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* Some resolvers want to even out the load on their nameservers.
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* Note that RES_BLAST overrides RES_ROTATE.
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*/
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if ((statp->options & RES_ROTATE) != 0U &&
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(statp->options & RES_BLAST) == 0U) {
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union res_sockaddr_union inu;
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struct sockaddr_in ina;
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int lastns = statp->nscount - 1;
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int fd;
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u_int16_t nstime;
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if (EXT(statp).ext != NULL)
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inu = EXT(statp).ext->nsaddrs[0];
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ina = statp->nsaddr_list[0];
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fd = EXT(statp).nssocks[0];
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nstime = EXT(statp).nstimes[0];
|
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for (ns = 0; ns < lastns; ns++) {
|
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if (EXT(statp).ext != NULL)
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EXT(statp).ext->nsaddrs[ns] =
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EXT(statp).ext->nsaddrs[ns + 1];
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statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
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EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
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EXT(statp).nstimes[ns] = EXT(statp).nstimes[ns + 1];
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}
|
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if (EXT(statp).ext != NULL)
|
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EXT(statp).ext->nsaddrs[lastns] = inu;
|
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statp->nsaddr_list[lastns] = ina;
|
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EXT(statp).nssocks[lastns] = fd;
|
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EXT(statp).nstimes[lastns] = nstime;
|
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}
|
|
|
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/*
|
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* Send request, RETRY times, or until successful.
|
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*/
|
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for (try = 0; try < statp->retry; try++) {
|
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for (ns = 0; ns < statp->nscount; ns++) {
|
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struct sockaddr *nsap;
|
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int nsaplen;
|
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nsap = get_nsaddr(statp, ns);
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nsaplen = get_salen(nsap);
|
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statp->_flags &= ~RES_F_LASTMASK;
|
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statp->_flags |= (ns << RES_F_LASTSHIFT);
|
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same_ns:
|
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if (statp->qhook) {
|
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int done = 0, loops = 0;
|
|
|
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do {
|
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res_sendhookact act;
|
|
|
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act = (*statp->qhook)(&nsap, &buf, &buflen,
|
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ans, anssiz, &resplen);
|
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switch (act) {
|
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case res_goahead:
|
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done = 1;
|
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break;
|
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case res_nextns:
|
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res_nclose(statp);
|
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goto next_ns;
|
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case res_done:
|
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return (resplen);
|
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case res_modified:
|
|
/* give the hook another try */
|
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if (++loops < 42) /*doug adams*/
|
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break;
|
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/*FALLTHROUGH*/
|
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case res_error:
|
|
/*FALLTHROUGH*/
|
|
default:
|
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goto fail;
|
|
}
|
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} while (!done);
|
|
}
|
|
|
|
Dprint(((statp->options & RES_DEBUG) &&
|
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getnameinfo(nsap, nsaplen, abuf, sizeof(abuf),
|
|
NULL, 0, niflags) == 0),
|
|
(stdout, ";; Querying server (# %d) address = %s\n",
|
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ns + 1, abuf));
|
|
|
|
|
|
if (v_circuit) {
|
|
/* Use VC; at most one attempt per server. */
|
|
try = statp->retry;
|
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n = send_vc(statp, buf, buflen, ans, anssiz, &terrno,
|
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ns);
|
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if (n < 0)
|
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goto fail;
|
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if (n == 0)
|
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goto next_ns;
|
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resplen = n;
|
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} else {
|
|
/* Use datagrams. */
|
|
n = send_dg(statp, buf, buflen, ans, anssiz, &terrno,
|
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ns, &v_circuit, &gotsomewhere);
|
|
if (n < 0)
|
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goto fail;
|
|
if (n == 0)
|
|
goto next_ns;
|
|
if (v_circuit)
|
|
goto same_ns;
|
|
resplen = n;
|
|
}
|
|
|
|
Dprint((statp->options & RES_DEBUG) ||
|
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((statp->pfcode & RES_PRF_REPLY) &&
|
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(statp->pfcode & RES_PRF_HEAD1)),
|
|
(stdout, ";; got answer:\n"));
|
|
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, "%s", ""),
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|
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;
|
|
{
|
|
|
|
#ifdef HAVE_SA_LEN
|
|
/* There are people do not set sa_len. Be forgiving to them. */
|
|
if (sa->sa_len)
|
|
return (sa->sa_len);
|
|
#endif
|
|
|
|
if (sa->sa_family == AF_INET)
|
|
return (sizeof(struct sockaddr_in));
|
|
else if (sa->sa_family == AF_INET6)
|
|
return (sizeof(struct sockaddr_in6));
|
|
else
|
|
return (0); /* unknown, die on connect */
|
|
}
|
|
|
|
/*
|
|
* pick appropriate nsaddr_list for use. see res_init() for initialization.
|
|
*/
|
|
static struct sockaddr *
|
|
get_nsaddr(statp, n)
|
|
res_state statp;
|
|
size_t n;
|
|
{
|
|
|
|
if (!statp->nsaddr_list[n].sin_family && EXT(statp).ext) {
|
|
/*
|
|
* - EXT(statp).ext->nsaddrs[n] holds an address that is larger
|
|
* than struct sockaddr, and
|
|
* - user code did not update statp->nsaddr_list[n].
|
|
*/
|
|
return (struct sockaddr *)(void *)&EXT(statp).ext->nsaddrs[n];
|
|
} else {
|
|
/*
|
|
* - user code updated statp->nsaddr_list[n], or
|
|
* - statp->nsaddr_list[n] has the same content as
|
|
* EXT(statp).ext->nsaddrs[n].
|
|
*/
|
|
return (struct sockaddr *)(void *)&statp->nsaddr_list[n];
|
|
}
|
|
}
|
|
|
|
static int
|
|
send_vc(res_state statp,
|
|
const u_char *buf, int buflen, u_char *ans, int anssiz,
|
|
int *terrno, int ns)
|
|
{
|
|
const HEADER *hp = (const HEADER *) buf;
|
|
HEADER *anhp = (HEADER *) ans;
|
|
struct sockaddr *nsap;
|
|
int nsaplen;
|
|
int truncating, connreset, resplen, n;
|
|
struct iovec iov[2];
|
|
u_short len;
|
|
u_char *cp;
|
|
void *tmp;
|
|
|
|
nsap = get_nsaddr(statp, ns);
|
|
nsaplen = get_salen(nsap);
|
|
|
|
connreset = 0;
|
|
same_ns:
|
|
truncating = 0;
|
|
|
|
/* Are we still talking to whom we want to talk to? */
|
|
if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
|
|
struct sockaddr_storage peer;
|
|
ISC_SOCKLEN_T size = sizeof peer;
|
|
|
|
if (getpeername(statp->_vcsock,
|
|
(struct sockaddr *)&peer, &size) < 0 ||
|
|
!sock_eq((struct sockaddr *)&peer, nsap)) {
|
|
res_nclose(statp);
|
|
statp->_flags &= ~RES_F_VC;
|
|
}
|
|
}
|
|
|
|
if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) {
|
|
if (statp->_vcsock >= 0)
|
|
res_nclose(statp);
|
|
|
|
statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0);
|
|
if (statp->_vcsock > highestFD) {
|
|
res_nclose(statp);
|
|
errno = ENOTSOCK;
|
|
}
|
|
if (statp->_vcsock < 0) {
|
|
switch (errno) {
|
|
case EPROTONOSUPPORT:
|
|
#ifdef EPFNOSUPPORT
|
|
case EPFNOSUPPORT:
|
|
#endif
|
|
case EAFNOSUPPORT:
|
|
Perror(statp, stderr, "socket(vc)", errno);
|
|
return (0);
|
|
default:
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "socket(vc)", errno);
|
|
return (-1);
|
|
}
|
|
}
|
|
errno = 0;
|
|
if (connect(statp->_vcsock, nsap, nsaplen) < 0) {
|
|
*terrno = errno;
|
|
Aerror(statp, stderr, "connect/vc", errno, nsap,
|
|
nsaplen);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
statp->_flags |= RES_F_VC;
|
|
}
|
|
|
|
/*
|
|
* Send length & message
|
|
*/
|
|
ns_put16((u_short)buflen, (u_char*)&len);
|
|
iov[0] = evConsIovec(&len, INT16SZ);
|
|
DE_CONST(buf, tmp);
|
|
iov[1] = evConsIovec(tmp, buflen);
|
|
if (writev(statp->_vcsock, iov, 2) != (INT16SZ + buflen)) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "write failed", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
/*
|
|
* Receive length & response
|
|
*/
|
|
read_len:
|
|
cp = ans;
|
|
len = INT16SZ;
|
|
while ((n = read(statp->_vcsock, (char *)cp, (int)len)) > 0) {
|
|
cp += n;
|
|
if ((len -= n) == 0)
|
|
break;
|
|
}
|
|
if (n <= 0) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "read failed", errno);
|
|
res_nclose(statp);
|
|
/*
|
|
* 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_nclose(statp);
|
|
goto same_ns;
|
|
}
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
resplen = ns_get16(ans);
|
|
if (resplen > anssiz) {
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; response truncated\n")
|
|
);
|
|
truncating = 1;
|
|
len = anssiz;
|
|
} else
|
|
len = resplen;
|
|
if (len < HFIXEDSZ) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n", len));
|
|
*terrno = EMSGSIZE;
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
cp = ans;
|
|
while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){
|
|
cp += n;
|
|
len -= n;
|
|
}
|
|
if (n <= 0) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "read(vc)", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
if (truncating) {
|
|
/*
|
|
* Flush rest of answer so connection stays in synch.
|
|
*/
|
|
anhp->tc = 1;
|
|
len = resplen - anssiz;
|
|
while (len != 0) {
|
|
char junk[PACKETSZ];
|
|
|
|
n = read(statp->_vcsock, junk,
|
|
(len > sizeof junk) ? sizeof junk : len);
|
|
if (n > 0)
|
|
len -= n;
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* If the calling applicating has bailed out of
|
|
* a previous call and failed to arrange to have
|
|
* the circuit closed or the server has got
|
|
* itself confused, then drop the packet and
|
|
* wait for the correct one.
|
|
*/
|
|
if (hp->id != anhp->id) {
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; old answer (unexpected):\n"),
|
|
ans, (resplen > anssiz) ? anssiz: resplen);
|
|
goto read_len;
|
|
}
|
|
|
|
/*
|
|
* All is well, or the error is fatal. Signal that the
|
|
* next nameserver ought not be tried.
|
|
*/
|
|
return (resplen);
|
|
}
|
|
|
|
static int
|
|
send_dg(res_state statp,
|
|
const u_char *buf, int buflen, u_char *ans, int anssiz,
|
|
int *terrno, int ns, int *v_circuit, int *gotsomewhere)
|
|
{
|
|
const HEADER *hp = (const HEADER *) buf;
|
|
HEADER *anhp = (HEADER *) ans;
|
|
const struct sockaddr *nsap;
|
|
int nsaplen;
|
|
struct timespec now, timeout, finish;
|
|
struct sockaddr_storage from;
|
|
ISC_SOCKLEN_T fromlen;
|
|
int resplen, seconds, n, s;
|
|
#ifdef USE_POLL
|
|
int polltimeout;
|
|
struct pollfd pollfd;
|
|
#else
|
|
fd_set dsmask;
|
|
#endif
|
|
|
|
nsap = get_nsaddr(statp, ns);
|
|
nsaplen = get_salen(nsap);
|
|
if (EXT(statp).nssocks[ns] == -1) {
|
|
EXT(statp).nssocks[ns] = socket(nsap->sa_family, SOCK_DGRAM, 0);
|
|
if (EXT(statp).nssocks[ns] > highestFD) {
|
|
res_nclose(statp);
|
|
errno = ENOTSOCK;
|
|
}
|
|
if (EXT(statp).nssocks[ns] < 0) {
|
|
switch (errno) {
|
|
case EPROTONOSUPPORT:
|
|
#ifdef EPFNOSUPPORT
|
|
case EPFNOSUPPORT:
|
|
#endif
|
|
case EAFNOSUPPORT:
|
|
Perror(statp, stderr, "socket(dg)", errno);
|
|
return (0);
|
|
default:
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "socket(dg)", errno);
|
|
return (-1);
|
|
}
|
|
}
|
|
#ifndef CANNOT_CONNECT_DGRAM
|
|
/*
|
|
* 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 (connect(EXT(statp).nssocks[ns], nsap, nsaplen) < 0) {
|
|
Aerror(statp, stderr, "connect(dg)", errno, nsap,
|
|
nsaplen);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; new DG socket\n"))
|
|
}
|
|
s = EXT(statp).nssocks[ns];
|
|
#ifndef CANNOT_CONNECT_DGRAM
|
|
if (send(s, (const char*)buf, buflen, 0) != buflen) {
|
|
Perror(statp, stderr, "send", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
#else /* !CANNOT_CONNECT_DGRAM */
|
|
if (sendto(s, (const char*)buf, buflen, 0, nsap, nsaplen) != buflen)
|
|
{
|
|
Aerror(statp, stderr, "sendto", errno, nsap, nsaplen);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
|
|
/*
|
|
* Wait for reply.
|
|
*/
|
|
seconds = (statp->retrans << ns);
|
|
if (ns > 0)
|
|
seconds /= statp->nscount;
|
|
if (seconds <= 0)
|
|
seconds = 1;
|
|
now = evNowTime();
|
|
timeout = evConsTime(seconds, 0);
|
|
finish = evAddTime(now, timeout);
|
|
goto nonow;
|
|
wait:
|
|
now = evNowTime();
|
|
nonow:
|
|
#ifndef USE_POLL
|
|
FD_ZERO(&dsmask);
|
|
FD_SET(s, &dsmask);
|
|
if (evCmpTime(finish, now) > 0)
|
|
timeout = evSubTime(finish, now);
|
|
else
|
|
timeout = evConsTime(0, 0);
|
|
n = pselect(s + 1, &dsmask, NULL, NULL, &timeout, NULL);
|
|
#else
|
|
timeout = evSubTime(finish, now);
|
|
if (timeout.tv_sec < 0)
|
|
timeout = evConsTime(0, 0);
|
|
polltimeout = 1000*timeout.tv_sec +
|
|
timeout.tv_nsec/1000000;
|
|
pollfd.fd = s;
|
|
pollfd.events = POLLRDNORM;
|
|
n = poll(&pollfd, 1, polltimeout);
|
|
#endif /* USE_POLL */
|
|
|
|
if (n == 0) {
|
|
Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n"));
|
|
*gotsomewhere = 1;
|
|
return (0);
|
|
}
|
|
if (n < 0) {
|
|
if (errno == EINTR)
|
|
goto wait;
|
|
#ifndef USE_POLL
|
|
Perror(statp, stderr, "select", errno);
|
|
#else
|
|
Perror(statp, stderr, "poll", errno);
|
|
#endif /* USE_POLL */
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
errno = 0;
|
|
fromlen = sizeof(from);
|
|
resplen = recvfrom(s, (char*)ans, anssiz,0,
|
|
(struct sockaddr *)&from, &fromlen);
|
|
if (resplen <= 0) {
|
|
Perror(statp, stderr, "recvfrom", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
*gotsomewhere = 1;
|
|
if (resplen < HFIXEDSZ) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n",
|
|
resplen));
|
|
*terrno = EMSGSIZE;
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
if (hp->id != anhp->id) {
|
|
/*
|
|
* response from old query, ignore it.
|
|
* XXX - potential security hazard could
|
|
* be detected here.
|
|
*/
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; old answer:\n"),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
goto wait;
|
|
}
|
|
if (!(statp->options & RES_INSECURE1) &&
|
|
!res_ourserver_p(statp, (struct sockaddr *)&from)) {
|
|
/*
|
|
* response from wrong server? ignore it.
|
|
* XXX - potential security hazard could
|
|
* be detected here.
|
|
*/
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; not our server:\n"),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
goto wait;
|
|
}
|
|
#ifdef RES_USE_EDNS0
|
|
if (anhp->rcode == FORMERR && (statp->options & RES_USE_EDNS0) != 0U) {
|
|
/*
|
|
* Do not retry if the server do not understand EDNS0.
|
|
* The case has to be captured here, as FORMERR packet do not
|
|
* carry query section, hence res_queriesmatch() returns 0.
|
|
*/
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout, "server rejected query with EDNS0:\n"),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
/* record the error */
|
|
statp->_flags |= RES_F_EDNS0ERR;
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
#endif
|
|
if (!(statp->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((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; wrong query name:\n"),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
goto wait;
|
|
}
|
|
if (anhp->rcode == SERVFAIL ||
|
|
anhp->rcode == NOTIMP ||
|
|
anhp->rcode == REFUSED) {
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout, "server rejected query:\n"),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
res_nclose(statp);
|
|
/* don't retry if called from dig */
|
|
if (!statp->pfcode)
|
|
return (0);
|
|
}
|
|
if (!(statp->options & RES_IGNTC) && anhp->tc) {
|
|
/*
|
|
* To get the rest of answer,
|
|
* use TCP with same server.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; truncated answer\n"));
|
|
*v_circuit = 1;
|
|
res_nclose(statp);
|
|
return (1);
|
|
}
|
|
/*
|
|
* All is well, or the error is fatal. Signal that the
|
|
* next nameserver ought not be tried.
|
|
*/
|
|
return (resplen);
|
|
}
|
|
|
|
static void
|
|
Aerror(const res_state statp, FILE *file, const char *string, int error,
|
|
const struct sockaddr *address, int alen)
|
|
{
|
|
int save = errno;
|
|
char hbuf[NI_MAXHOST];
|
|
char sbuf[NI_MAXSERV];
|
|
|
|
alen = alen;
|
|
|
|
if ((statp->options & RES_DEBUG) != 0U) {
|
|
if (getnameinfo(address, alen, hbuf, sizeof(hbuf),
|
|
sbuf, sizeof(sbuf), niflags)) {
|
|
strncpy(hbuf, "?", sizeof(hbuf) - 1);
|
|
hbuf[sizeof(hbuf) - 1] = '\0';
|
|
strncpy(sbuf, "?", sizeof(sbuf) - 1);
|
|
sbuf[sizeof(sbuf) - 1] = '\0';
|
|
}
|
|
fprintf(file, "res_send: %s ([%s].%s): %s\n",
|
|
string, hbuf, sbuf, strerror(error));
|
|
}
|
|
errno = save;
|
|
}
|
|
|
|
static void
|
|
Perror(const res_state statp, FILE *file, const char *string, int error) {
|
|
int save = errno;
|
|
|
|
if ((statp->options & RES_DEBUG) != 0U)
|
|
fprintf(file, "res_send: %s: %s\n",
|
|
string, strerror(error));
|
|
errno = save;
|
|
}
|
|
|
|
static int
|
|
sock_eq(struct sockaddr *a, struct sockaddr *b) {
|
|
struct sockaddr_in *a4, *b4;
|
|
struct sockaddr_in6 *a6, *b6;
|
|
|
|
if (a->sa_family != b->sa_family)
|
|
return 0;
|
|
switch (a->sa_family) {
|
|
case AF_INET:
|
|
a4 = (struct sockaddr_in *)a;
|
|
b4 = (struct sockaddr_in *)b;
|
|
return a4->sin_port == b4->sin_port &&
|
|
a4->sin_addr.s_addr == b4->sin_addr.s_addr;
|
|
case AF_INET6:
|
|
a6 = (struct sockaddr_in6 *)a;
|
|
b6 = (struct sockaddr_in6 *)b;
|
|
return a6->sin6_port == b6->sin6_port &&
|
|
#ifdef HAVE_SIN6_SCOPE_ID
|
|
a6->sin6_scope_id == b6->sin6_scope_id &&
|
|
#endif
|
|
IN6_ARE_ADDR_EQUAL(&a6->sin6_addr, &b6->sin6_addr);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#if defined(NEED_PSELECT) && !defined(USE_POLL)
|
|
/* XXX needs to move to the porting library. */
|
|
static int
|
|
pselect(int nfds, void *rfds, void *wfds, void *efds,
|
|
struct timespec *tsp, const sigset_t *sigmask)
|
|
{
|
|
struct timeval tv, *tvp;
|
|
sigset_t sigs;
|
|
int n;
|
|
|
|
if (tsp) {
|
|
tvp = &tv;
|
|
tv = evTimeVal(*tsp);
|
|
} else
|
|
tvp = NULL;
|
|
if (sigmask)
|
|
sigprocmask(SIG_SETMASK, sigmask, &sigs);
|
|
n = select(nfds, rfds, wfds, efds, tvp);
|
|
if (sigmask)
|
|
sigprocmask(SIG_SETMASK, &sigs, NULL);
|
|
if (tsp)
|
|
*tsp = evTimeSpec(tv);
|
|
return (n);
|
|
}
|
|
#endif
|