874 lines
22 KiB
C
874 lines
22 KiB
C
/* $NetBSD: res_send.c,v 1.4 2001/05/17 23:00:20 itojun Exp $ */
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/*
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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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* 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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* CONSORTIUM 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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#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 8.42 2001/03/07 06:48:03 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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/* Options. Leave them on. */
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#define DEBUG
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#include "res_debug.h"
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#define EXT(res) ((res)->_u._ext)
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static const int highestFD = FD_SETSIZE - 1;
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/* Forward. */
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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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struct sockaddr_in);
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static void Perror(const res_state, FILE *, const char *, int);
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static int sock_eq(struct sockaddr_in *, struct sockaddr_in *);
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#ifdef NEED_PSELECT
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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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/* 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_in *inp) {
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struct sockaddr_in ina;
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int ns;
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ina = *inp;
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for (ns = 0; ns < statp->nscount; ns++) {
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const struct sockaddr_in *srv = &statp->nsaddr_list[ns];
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if (srv->sin_family == ina.sin_family &&
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srv->sin_port == ina.sin_port &&
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(srv->sin_addr.s_addr == INADDR_ANY ||
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srv->sin_addr.s_addr == ina.sin_addr.s_addr))
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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_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(((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(((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 ((((HEADER *)buf1)->opcode == ns_o_update) &&
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(((HEADER *)buf2)->opcode == ns_o_update))
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return (1);
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if (qdcount != ntohs(((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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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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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 (!sock_eq(&statp->nsaddr_list[ns],
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&EXT(statp).nsaddrs[ns])) {
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needclose++;
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break;
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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).nsaddrs[ns] = statp->nsaddr_list[ns];
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EXT(statp).nstimes[ns] = RES_MAXTIME;
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EXT(statp).nssocks[ns] = -1;
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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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* 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) != 0 &&
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(statp->options & RES_BLAST) == 0) {
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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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ina = statp->nsaddr_list[0];
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fd = EXT(statp).nssocks[0];
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nstime = EXT(statp).nstimes[ns];
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for (ns = 0; ns < lastns; ns++) {
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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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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_in *nsap = &statp->nsaddr_list[ns];
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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:
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/* 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:
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/*FALLTHROUGH*/
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default:
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goto fail;
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}
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} while (!done);
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}
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Dprint(statp->options & RES_DEBUG,
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(stdout, ";; Querying server (# %d) address = %s\n",
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ns + 1, inet_ntoa(nsap->sin_addr)));
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if (v_circuit) {
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/* Use VC; at most one attempt per server. */
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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 {
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/* Use datagrams. */
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n = send_dg(statp, buf, buflen, ans, anssiz, &terrno,
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ns, &v_circuit, &gotsomewhere);
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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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if (v_circuit)
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goto same_ns;
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resplen = n;
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}
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Dprint((statp->options & RES_DEBUG) ||
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((statp->pfcode & RES_PRF_REPLY) &&
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(statp->pfcode & RES_PRF_HEAD1)),
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(stdout, ";; got answer:\n"));
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DprintQ((statp->options & RES_DEBUG) ||
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(statp->pfcode & RES_PRF_REPLY),
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(stdout, ""),
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ans, (resplen > anssiz) ? anssiz : resplen);
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/*
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* If we have temporarily opened a virtual circuit,
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* or if we haven't been asked to keep a socket open,
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* close the socket.
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*/
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if ((v_circuit && (statp->options & RES_USEVC) == 0) ||
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(statp->options & RES_STAYOPEN) == 0) {
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res_nclose(statp);
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}
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if (statp->rhook) {
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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->rhook)(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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case res_done:
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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_modified:
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/* 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:
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/*FALLTHROUGH*/
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default:
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goto fail;
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}
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} while (!done);
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}
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return (resplen);
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next_ns: ;
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} /*foreach ns*/
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} /*foreach retry*/
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res_nclose(statp);
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if (!v_circuit) {
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if (!gotsomewhere)
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errno = ECONNREFUSED; /* no nameservers found */
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else
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errno = ETIMEDOUT; /* no answer obtained */
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} else
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errno = terrno;
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return (-1);
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fail:
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res_nclose(statp);
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return (-1);
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}
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/* Private */
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static int
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send_vc(res_state statp,
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const u_char *buf, int buflen, u_char *ans, int anssiz,
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int *terrno, int ns)
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{
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const HEADER *hp = (HEADER *) buf;
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HEADER *anhp = (HEADER *) ans;
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struct sockaddr_in *nsap = &statp->nsaddr_list[ns];
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int truncating, connreset, resplen, n;
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struct iovec iov[2];
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u_short len;
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u_char *cp;
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connreset = 0;
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same_ns:
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truncating = 0;
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/* Are we still talking to whom we want to talk to? */
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if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
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struct sockaddr_in peer;
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int size = sizeof peer;
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if (getpeername(statp->_vcsock,
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(struct sockaddr *)&peer, &size) < 0 ||
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!sock_eq(&peer, nsap)) {
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res_nclose(statp);
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statp->_flags &= ~RES_F_VC;
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}
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}
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if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) {
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if (statp->_vcsock >= 0)
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res_nclose(statp);
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statp->_vcsock = socket(PF_INET, SOCK_STREAM, 0);
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if (statp->_vcsock > highestFD) {
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res_nclose(statp);
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errno = ENOTSOCK;
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}
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if (statp->_vcsock < 0) {
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*terrno = errno;
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Perror(statp, stderr, "socket(vc)", errno);
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return (-1);
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}
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errno = 0;
|
|
if (connect(statp->_vcsock, (struct sockaddr *)nsap,
|
|
sizeof *nsap) < 0) {
|
|
*terrno = errno;
|
|
Aerror(statp, stderr, "connect/vc", errno, *nsap);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
statp->_flags |= RES_F_VC;
|
|
}
|
|
|
|
/*
|
|
* Send length & message
|
|
*/
|
|
putshort((u_short)buflen, (u_char*)&len);
|
|
iov[0] = evConsIovec(&len, INT16SZ);
|
|
iov[1] = evConsIovec((void*)buf, 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 = (HEADER *) buf;
|
|
HEADER *anhp = (HEADER *) ans;
|
|
const struct sockaddr_in *nsap = &statp->nsaddr_list[ns];
|
|
struct timespec now, timeout, finish;
|
|
fd_set dsmask;
|
|
struct sockaddr_in from;
|
|
int fromlen, resplen, seconds, n, s;
|
|
|
|
if (EXT(statp).nssocks[ns] == -1) {
|
|
EXT(statp).nssocks[ns] = socket(PF_INET, SOCK_DGRAM, 0);
|
|
if (EXT(statp).nssocks[ns] > highestFD) {
|
|
res_nclose(statp);
|
|
errno = ENOTSOCK;
|
|
}
|
|
if (EXT(statp).nssocks[ns] < 0) {
|
|
*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], (struct sockaddr *)nsap,
|
|
sizeof *nsap) < 0) {
|
|
Aerror(statp, stderr, "connect(dg)", errno, *nsap);
|
|
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, (char*)buf, buflen, 0) != buflen) {
|
|
Perror(statp, stderr, "send", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
#else /* !CANNOT_CONNECT_DGRAM */
|
|
if (sendto(s, (char*)buf, buflen, 0,
|
|
(struct sockaddr *)nsap, sizeof *nsap) != buflen)
|
|
{
|
|
Aerror(statp, stderr, "sendto", errno, *nsap);
|
|
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:
|
|
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);
|
|
if (n == 0) {
|
|
Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n"));
|
|
*gotsomewhere = 1;
|
|
return (0);
|
|
}
|
|
if (n < 0) {
|
|
if (errno == EINTR)
|
|
goto wait;
|
|
Perror(statp, stderr, "select", errno);
|
|
res_nclose(statp);
|
|
return (0);
|
|
}
|
|
errno = 0;
|
|
fromlen = sizeof(struct sockaddr_in);
|
|
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, &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;
|
|
}
|
|
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,
|
|
struct sockaddr_in address)
|
|
{
|
|
int save = errno;
|
|
|
|
if ((statp->options & RES_DEBUG) != 0) {
|
|
char tmp[sizeof "255.255.255.255"];
|
|
|
|
fprintf(file, "res_send: %s ([%s].%u): %s\n",
|
|
string,
|
|
inet_ntop(address.sin_family, &address.sin_addr,
|
|
tmp, sizeof tmp),
|
|
ntohs(address.sin_port),
|
|
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) != 0)
|
|
fprintf(file, "res_send: %s: %s\n",
|
|
string, strerror(error));
|
|
errno = save;
|
|
}
|
|
|
|
static int
|
|
sock_eq(struct sockaddr_in *a1, struct sockaddr_in *a2) {
|
|
return ((a1->sin_family == a2->sin_family) &&
|
|
(a1->sin_port == a2->sin_port) &&
|
|
(a1->sin_addr.s_addr == a2->sin_addr.s_addr));
|
|
}
|
|
|
|
#ifdef NEED_PSELECT
|
|
/* 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
|