872 lines
23 KiB
C
872 lines
23 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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* Portions Copyright (c) 1996-2001 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 1.7 2001/02/22 07:28:25 mellon Exp $";
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#endif /* LIBC_SCCS and not lint */
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/* Rename the I/O functions in case we're tracing. */
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#define send trace_mr_send
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#define recvfrom trace_mr_recvfrom
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#define read trace_mr_read
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#define connect trace_mr_connect
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#define socket trace_mr_socket
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#define bind trace_mr_bind
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#define close trace_mr_close
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#define select trace_mr_select
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#define time trace_mr_time
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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 <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/inet.h>
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#include <errno.h>
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#include <netdb.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 "minires/minires.h"
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#include "arpa/nameser.h"
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#define CHECK_SRVR_ADDR
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static int cmpsock(struct sockaddr_in *a1, struct sockaddr_in *a2);
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void res_pquery(const res_state, const u_char *, int, FILE *);
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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(((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 = getUShort(cp); cp += INT16SZ;
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tclass = getUShort(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 = getUShort(cp); cp += INT16SZ;
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tclass = getUShort(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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isc_result_t
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res_nsend(res_state statp,
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double *buf, unsigned buflen,
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double *ans, unsigned anssiz, unsigned *ansret)
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{
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HEADER *hp = (HEADER *) buf;
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HEADER *anhp = (HEADER *) ans;
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int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns, n;
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u_int badns; /* XXX NSMAX can't exceed #/bits in this variable */
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static int highestFD = FD_SETSIZE - 1;
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if (anssiz < HFIXEDSZ) {
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return ISC_R_INVALIDARG;
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}
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DprintQ((statp->options & RES_DEBUG) ||
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(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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connreset = 0;
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terrno = ISC_R_TIMEDOUT;
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badns = 0;
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/*
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* Some callers want to even out the load on their resolver list.
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*/
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if (statp->nscount > 0 && (statp->options & RES_ROTATE) != 0) {
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struct sockaddr_in ina;
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int lastns = statp->nscount - 1;
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ina = statp->nsaddr_list[0];
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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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statp->nsaddr_list[lastns] = ina;
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}
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#if defined (TRACING)
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trace_mr_statp_setup (statp);
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#endif
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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 (badns & (1 << ns)) {
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res_nclose(statp);
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goto next_ns;
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}
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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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return ISC_R_UNEXPECTED;
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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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int truncated;
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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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/* Use VC; at most one attempt per server. */
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try = statp->retry;
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truncated = 0;
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/* Are we still talking to whom we want to talk to? */
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if (statp->_sock >= 0 &&
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(statp->_flags & RES_F_VC) != 0) {
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struct sockaddr_in peer;
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SOCKLEN_T size = sizeof(peer);
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if (getpeername(statp->_sock,
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(struct sockaddr *)&peer,
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&size) < 0) {
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res_nclose(statp);
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statp->_flags &= ~RES_F_VC;
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} else if (!cmpsock(&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->_sock < 0 ||
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(statp->_flags & RES_F_VC) == 0) {
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if (statp->_sock >= 0)
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res_nclose(statp);
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statp->_sock = socket(PF_INET,
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SOCK_STREAM, 0);
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if (statp->_sock < 0 ||
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statp->_sock > highestFD) {
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terrno = uerr2isc (errno);
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Perror(statp, stderr,
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"socket(vc)", errno);
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return (-1);
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}
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errno = 0;
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if (connect(statp->_sock,
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(struct sockaddr *)nsap,
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sizeof *nsap) < 0) {
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terrno = uerr2isc (errno);
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Aerror(statp, stderr, "connect/vc",
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errno, *nsap);
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badns |= (1 << ns);
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res_nclose(statp);
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goto next_ns;
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}
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statp->_flags |= RES_F_VC;
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}
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/*
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* Send length & message
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*/
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putUShort((u_char*)&len, buflen);
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iov[0].iov_base = (caddr_t)&len;
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iov[0].iov_len = INT16SZ;
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iov[1].iov_base = (const caddr_t)buf;
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iov[1].iov_len = buflen;
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if (writev(statp->_sock, iov, 2) !=
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(INT16SZ + buflen)) {
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terrno = uerr2isc (errno);
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Perror(statp, stderr, "write failed", errno);
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badns |= (1 << ns);
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res_nclose(statp);
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goto next_ns;
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}
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/*
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* Receive length & response
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*/
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read_len:
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cp = (u_char *)ans;
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len = INT16SZ;
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while ((n = read(statp->_sock,
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(char *)cp, (unsigned)len)) > 0) {
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cp += n;
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if ((len -= n) <= 0)
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break;
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}
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if (n <= 0) {
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terrno = uerr2isc (errno);
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Perror(statp, stderr, "read failed", errno);
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res_nclose(statp);
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/*
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* A long running process might get its TCP
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* connection reset if the remote server was
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* restarted. Requery the server instead of
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* trying a new one. When there is only one
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* server, this means that a query might work
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* instead of failing. We only allow one reset
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* per query to prevent looping.
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*/
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if (terrno == ISC_R_CONNREFUSED &&
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!connreset) {
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connreset = 1;
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res_nclose(statp);
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goto same_ns;
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}
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res_nclose(statp);
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goto next_ns;
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}
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resplen = getUShort ((unsigned char *)ans);
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if (resplen > anssiz) {
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Dprint(statp->options & RES_DEBUG,
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(stdout, ";; response truncated\n")
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);
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truncated = 1;
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len = anssiz;
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} else
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len = resplen;
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if (len < HFIXEDSZ) {
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/*
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* Undersized message.
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*/
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Dprint(statp->options & RES_DEBUG,
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(stdout, ";; undersized: %d\n", len));
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terrno = ISC_R_NOSPACE;
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badns |= (1 << ns);
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res_nclose(statp);
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goto next_ns;
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}
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cp = (u_char *)ans;
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while (len != 0 &&
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(n = read(statp->_sock,
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(char *)cp, (unsigned)len))
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> 0) {
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cp += n;
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len -= n;
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}
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if (n <= 0) {
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terrno = uerr2isc (errno);
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Perror(statp, stderr, "read(vc)", errno);
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res_nclose(statp);
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goto next_ns;
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}
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if (truncated) {
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/*
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* Flush rest of answer
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* so connection stays in synch.
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*/
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anhp->tc = 1;
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len = resplen - anssiz;
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while (len != 0) {
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char junk[PACKETSZ];
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n = (len > sizeof(junk)
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? sizeof(junk)
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: len);
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n = read(statp->_sock,
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junk, (unsigned)n);
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if (n > 0)
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len -= n;
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else
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break;
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}
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}
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/*
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* The calling applicating has bailed out of
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* a previous call and failed to arrange to have
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* the circuit closed or the server has got
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* itself confused. Anyway drop the packet and
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* wait for the correct one.
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*/
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if (hp->id != anhp->id) {
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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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";; old answer (unexpected):\n"),
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ans, (resplen>anssiz)?anssiz:resplen);
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goto read_len;
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}
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} else {
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/*
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* Use datagrams.
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*/
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int start, timeout, finish;
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fd_set dsmask;
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struct sockaddr_in from;
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SOCKLEN_T fromlen;
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int seconds;
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if (statp->_sock < 0 ||
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(statp->_flags & RES_F_VC) != 0) {
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if ((statp->_flags & RES_F_VC) != 0)
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res_nclose(statp);
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statp->_sock = socket(PF_INET, SOCK_DGRAM, 0);
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if (statp->_sock < 0 ||
|
|
statp->_sock > highestFD) {
|
|
#ifndef CAN_RECONNECT
|
|
bad_dg_sock:
|
|
#endif
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr,
|
|
"socket(dg)", errno);
|
|
return terrno;
|
|
}
|
|
statp->_flags &= ~RES_F_CONN;
|
|
}
|
|
#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 we have sent queries to at least two servers,
|
|
* however, we don't want to remain connected,
|
|
* as we wish to receive answers from the first
|
|
* server to respond.
|
|
*/
|
|
if (statp->nscount == 1 || (try == 0 && ns == 0)) {
|
|
/*
|
|
* Connect only if we are sure we won't
|
|
* receive a response from another server.
|
|
*/
|
|
if ((statp->_flags & RES_F_CONN) == 0) {
|
|
if (connect(statp->_sock,
|
|
(struct sockaddr *)nsap,
|
|
sizeof *nsap) < 0) {
|
|
Aerror(statp, stderr,
|
|
"connect(dg)",
|
|
errno, *nsap);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
statp->_flags |= RES_F_CONN;
|
|
}
|
|
if (send(statp->_sock,
|
|
(const char*)buf, (unsigned)buflen, 0)
|
|
!= buflen) {
|
|
Perror(statp, stderr, "send", errno);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
} else {
|
|
/*
|
|
* Disconnect if we want to listen
|
|
* for responses from more than one server.
|
|
*/
|
|
if ((statp->_flags & RES_F_CONN) != 0) {
|
|
#ifdef CAN_RECONNECT
|
|
struct sockaddr_in no_addr;
|
|
|
|
no_addr.sin_family = AF_INET;
|
|
no_addr.sin_addr.s_addr = INADDR_ANY;
|
|
no_addr.sin_port = 0;
|
|
(void) connect(statp->_sock,
|
|
(struct sockaddr *)
|
|
&no_addr,
|
|
sizeof no_addr);
|
|
#else
|
|
struct sockaddr_in local_addr;
|
|
SOCKLEN_T len;
|
|
int result, s1;
|
|
|
|
len = sizeof(local_addr);
|
|
s1 = socket(PF_INET, SOCK_DGRAM, 0);
|
|
result = getsockname(statp->_sock,
|
|
(struct sockaddr *)&local_addr,
|
|
&len);
|
|
if (s1 < 0)
|
|
goto bad_dg_sock;
|
|
(void) dup2(s1, statp->_sock);
|
|
(void) close(s1);
|
|
if (result == 0) {
|
|
/*
|
|
* Attempt to rebind to old
|
|
* port. Note connected socket
|
|
* has an sin_addr set.
|
|
*/
|
|
local_addr.sin_addr.s_addr =
|
|
htonl(0);
|
|
(void)bind(statp->_sock,
|
|
(struct sockaddr *)
|
|
&local_addr,
|
|
(unsigned)len);
|
|
}
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; new DG socket\n"))
|
|
#endif /* CAN_RECONNECT */
|
|
statp->_flags &= ~RES_F_CONN;
|
|
errno = 0;
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
if (sendto(statp->_sock,
|
|
(const char *)buf, buflen, 0,
|
|
(struct sockaddr *)nsap,
|
|
sizeof *nsap)
|
|
!= buflen) {
|
|
Aerror(statp, stderr, "sendto", errno, *nsap);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
#ifndef CANNOT_CONNECT_DGRAM
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
|
|
if (statp->_sock < 0 || statp->_sock > highestFD) {
|
|
Perror(statp, stderr,
|
|
"fd out-of-bounds", EMFILE);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
|
|
/*
|
|
* Wait for reply
|
|
*/
|
|
seconds = (statp->retrans << try);
|
|
if (try > 0)
|
|
seconds /= statp->nscount;
|
|
if (seconds <= 0)
|
|
seconds = 1;
|
|
start = cur_time;
|
|
timeout = seconds;
|
|
finish = start + timeout;
|
|
wait:
|
|
FD_ZERO(&dsmask);
|
|
FD_SET(statp->_sock, &dsmask);
|
|
{
|
|
struct timeval t;
|
|
t.tv_sec = timeout;
|
|
t.tv_usec = 0;
|
|
n = select(statp->_sock + 1,
|
|
&dsmask, NULL, NULL, &t);
|
|
}
|
|
if (n == 0) {
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; timeout\n"));
|
|
gotsomewhere = 1;
|
|
goto next_ns;
|
|
}
|
|
if (n < 0) {
|
|
if (errno == EINTR) {
|
|
if (finish >= cur_time) {
|
|
timeout = finish - cur_time;
|
|
goto wait;
|
|
}
|
|
}
|
|
Perror(statp, stderr, "select", errno);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
errno = 0;
|
|
fromlen = sizeof(struct sockaddr_in);
|
|
resplen = recvfrom(statp->_sock,
|
|
(char *)ans, anssiz, 0,
|
|
(struct sockaddr *)&from, &fromlen);
|
|
if (resplen <= 0) {
|
|
Perror(statp, stderr, "recvfrom", errno);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
gotsomewhere = 1;
|
|
if (resplen < HFIXEDSZ) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n",
|
|
resplen));
|
|
terrno = ISC_R_NOSPACE;
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
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;
|
|
}
|
|
#ifdef CHECK_SRVR_ADDR
|
|
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;
|
|
}
|
|
#endif
|
|
if (!(statp->options & RES_INSECURE2) &&
|
|
!res_queriesmatch((u_char *)buf,
|
|
((u_char *)buf) + buflen,
|
|
(u_char *)ans,
|
|
((u_char *)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);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
/* don't retry if called from dig */
|
|
if (!statp->pfcode)
|
|
goto next_ns;
|
|
}
|
|
if (!(statp->options & RES_IGNTC) && anhp->tc) {
|
|
/*
|
|
* get rest of answer;
|
|
* use TCP with same server.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; truncated answer\n"));
|
|
v_circuit = 1;
|
|
res_nclose(statp);
|
|
goto same_ns;
|
|
}
|
|
} /*if vc/dg*/
|
|
Dprint((statp->options & RES_DEBUG) ||
|
|
((statp->pfcode & RES_PRF_REPLY) &&
|
|
(statp->pfcode & RES_PRF_HEAD1)),
|
|
(stdout, ";; got answer:\n"));
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ""),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
/*
|
|
* If using virtual circuits, we assume that the first server
|
|
* is preferred over the rest (i.e. it is on the local
|
|
* machine) and only keep that one open.
|
|
* If we have temporarily opened a virtual circuit,
|
|
* or if we haven't been asked to keep a socket open,
|
|
* close the socket.
|
|
*/
|
|
if ((v_circuit && (!(statp->options & RES_USEVC) || ns != 0)) ||
|
|
!(statp->options & RES_STAYOPEN)) {
|
|
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:
|
|
return ISC_R_UNEXPECTED;
|
|
}
|
|
} while (!done);
|
|
|
|
}
|
|
*ansret = resplen;
|
|
return ISC_R_SUCCESS;
|
|
next_ns: ;
|
|
} /*foreach ns*/
|
|
} /*foreach retry*/
|
|
res_nclose(statp);
|
|
if (!v_circuit) {
|
|
if (!gotsomewhere)
|
|
terrno = ISC_R_CONNREFUSED; /* no nameservers found */
|
|
else
|
|
errno = ISC_R_TIMEDOUT; /* no answer obtained */
|
|
}
|
|
return terrno;
|
|
}
|
|
|
|
/*
|
|
* This routine is for closing the socket if a virtual circuit is used and
|
|
* the program wants to close it. This provides support for endhostent()
|
|
* which expects to close the socket.
|
|
*
|
|
* This routine is not expected to be user visible.
|
|
*/
|
|
void
|
|
res_nclose(res_state statp) {
|
|
if (statp->_sock >= 0) {
|
|
(void) close(statp->_sock);
|
|
statp->_sock = -1;
|
|
statp->_flags &= ~(RES_F_VC | RES_F_CONN);
|
|
}
|
|
}
|
|
|
|
/* Private */
|
|
static int
|
|
cmpsock(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
|