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0cd8552045
Use DIAG_IGNORE_NEEDS_COMMENT instead since the compiler should have seen that NS never goes beyond MAXNS.
1527 lines
41 KiB
C
1527 lines
41 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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* 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[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixie 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 <assert.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 <sys/poll.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 <sys/ioctl.h>
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#include <errno.h>
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#include <fcntl.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 <kernel-features.h>
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#include <libc-internal.h>
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#if PACKETSZ > 65536
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#define MAXPACKET PACKETSZ
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#else
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#define MAXPACKET 65536
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#endif
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#ifndef __ASSUME_SOCK_CLOEXEC
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static int __have_o_nonblock;
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#else
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# define __have_o_nonblock 0
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#endif
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/* From ev_streams.c. */
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static inline void
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__attribute ((always_inline))
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evConsIovec(void *buf, size_t cnt, struct iovec *vec) {
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memset(vec, 0xf5, sizeof (*vec));
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vec->iov_base = buf;
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vec->iov_len = cnt;
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}
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/* From ev_timers.c. */
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#define BILLION 1000000000
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static inline void
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evConsTime(struct timespec *res, time_t sec, long nsec) {
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res->tv_sec = sec;
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res->tv_nsec = nsec;
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}
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static inline void
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evAddTime(struct timespec *res, const struct timespec *addend1,
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const struct timespec *addend2) {
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res->tv_sec = addend1->tv_sec + addend2->tv_sec;
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res->tv_nsec = addend1->tv_nsec + addend2->tv_nsec;
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if (res->tv_nsec >= BILLION) {
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res->tv_sec++;
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res->tv_nsec -= BILLION;
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}
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}
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static inline void
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evSubTime(struct timespec *res, const struct timespec *minuend,
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const struct timespec *subtrahend) {
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res->tv_sec = minuend->tv_sec - subtrahend->tv_sec;
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if (minuend->tv_nsec >= subtrahend->tv_nsec)
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res->tv_nsec = minuend->tv_nsec - subtrahend->tv_nsec;
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else {
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res->tv_nsec = (BILLION
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- subtrahend->tv_nsec + minuend->tv_nsec);
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res->tv_sec--;
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}
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}
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static int
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evCmpTime(struct timespec a, struct timespec b) {
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long x = a.tv_sec - b.tv_sec;
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if (x == 0L)
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x = a.tv_nsec - b.tv_nsec;
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return (x < 0L ? (-1) : x > 0L ? (1) : (0));
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}
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static void
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evNowTime(struct timespec *res) {
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struct timeval now;
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if (gettimeofday(&now, NULL) < 0)
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evConsTime(res, 0, 0);
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else
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TIMEVAL_TO_TIMESPEC (&now, res);
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}
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/* Options. Leave them on. */
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/* #undef DEBUG */
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#include "res_debug.h"
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#define EXT(res) ((res)->_u._ext)
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/* Forward. */
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static int send_vc(res_state, const u_char *, int,
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const u_char *, int,
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u_char **, int *, int *, int, u_char **,
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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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const u_char *, int,
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u_char **, int *, int *, int,
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int *, int *, u_char **,
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u_char **, int *, int *, int *);
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#ifdef DEBUG
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static void Aerror(const res_state, FILE *, const char *, int,
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const struct sockaddr *);
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static void Perror(const res_state, FILE *, const char *, int);
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#endif
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static int sock_eq(struct sockaddr_in6 *, struct sockaddr_in6 *);
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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_in6 *inp)
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{
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int ns;
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if (inp->sin6_family == AF_INET) {
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struct sockaddr_in *in4p = (struct sockaddr_in *) inp;
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in_port_t port = in4p->sin_port;
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in_addr_t addr = in4p->sin_addr.s_addr;
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for (ns = 0; ns < MAXNS; ns++) {
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const struct sockaddr_in *srv =
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(struct sockaddr_in *)EXT(statp).nsaddrs[ns];
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if ((srv != NULL) && (srv->sin_family == AF_INET) &&
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(srv->sin_port == port) &&
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(srv->sin_addr.s_addr == INADDR_ANY ||
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srv->sin_addr.s_addr == addr))
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return (1);
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}
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} else if (inp->sin6_family == AF_INET6) {
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for (ns = 0; ns < MAXNS; ns++) {
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const struct sockaddr_in6 *srv = EXT(statp).nsaddrs[ns];
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if ((srv != NULL) && (srv->sin6_family == AF_INET6) &&
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(srv->sin6_port == inp->sin6_port) &&
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!(memcmp(&srv->sin6_addr, &in6addr_any,
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sizeof (struct in6_addr)) &&
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memcmp(&srv->sin6_addr, &inp->sin6_addr,
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sizeof (struct in6_addr))))
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return (1);
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}
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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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NS_GET16(ttype, cp);
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NS_GET16(tclass, cp);
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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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libresolv_hidden_def (res_nameinquery)
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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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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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/* Note that we initially do not convert QDCOUNT to the host byte
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order. We can compare it with the second buffer's QDCOUNT
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value without doing this. */
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int qdcount = ((HEADER*)buf1)->qdcount;
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if (qdcount != ((HEADER*)buf2)->qdcount)
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return (0);
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qdcount = htons (qdcount);
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const u_char *cp = buf1 + HFIXEDSZ;
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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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NS_GET16(ttype, cp);
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NS_GET16(tclass, cp);
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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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libresolv_hidden_def (res_queriesmatch)
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int
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__libc_res_nsend(res_state statp, const u_char *buf, int buflen,
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const u_char *buf2, int buflen2,
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u_char *ans, int anssiz, u_char **ansp, u_char **ansp2,
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int *nansp2, int *resplen2, int *ansp2_malloced)
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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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__set_errno (ESRCH);
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return (-1);
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}
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if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) {
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__set_errno (EINVAL);
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return (-1);
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}
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#ifdef USE_HOOKS
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if (__glibc_unlikely (statp->qhook || statp->rhook)) {
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if (anssiz < MAXPACKET && ansp) {
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u_char *buf = malloc (MAXPACKET);
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if (buf == NULL)
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return (-1);
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memcpy (buf, ans, HFIXEDSZ);
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*ansp = buf;
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ans = buf;
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anssiz = MAXPACKET;
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}
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}
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#endif
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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)
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|| buflen > PACKETSZ
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|| buflen2 > 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).nsinit) {
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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 < MAXNS; ns++) {
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unsigned int map = EXT(statp).nsmap[ns];
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if (map < MAXNS
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&& !sock_eq((struct sockaddr_in6 *)
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&statp->nsaddr_list[map],
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EXT(statp).nsaddrs[ns]))
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{
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needclose++;
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break;
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}
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}
|
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if (needclose)
|
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__res_iclose(statp, false);
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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).nsinit == 0) {
|
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unsigned char map[MAXNS];
|
|
|
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memset (map, MAXNS, sizeof (map));
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for (n = 0; n < MAXNS; n++) {
|
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ns = EXT(statp).nsmap[n];
|
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if (ns < statp->nscount)
|
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map[ns] = n;
|
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else if (ns < MAXNS) {
|
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free(EXT(statp).nsaddrs[n]);
|
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EXT(statp).nsaddrs[n] = NULL;
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EXT(statp).nsmap[n] = MAXNS;
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}
|
|
}
|
|
n = statp->nscount;
|
|
if (statp->nscount > EXT(statp).nscount)
|
|
for (n = EXT(statp).nscount, ns = 0;
|
|
n < statp->nscount; n++) {
|
|
while (ns < MAXNS
|
|
&& EXT(statp).nsmap[ns] != MAXNS)
|
|
ns++;
|
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if (ns == MAXNS)
|
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break;
|
|
/* NS never exceeds MAXNS, but gcc 4.9 somehow
|
|
does not see this. */
|
|
DIAG_PUSH_NEEDS_COMMENT;
|
|
DIAG_IGNORE_NEEDS_COMMENT (4.9,
|
|
"-Warray-bounds");
|
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EXT(statp).nsmap[ns] = n;
|
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DIAG_POP_NEEDS_COMMENT;
|
|
map[n] = ns++;
|
|
}
|
|
EXT(statp).nscount = n;
|
|
for (ns = 0; ns < EXT(statp).nscount; ns++) {
|
|
n = map[ns];
|
|
if (EXT(statp).nsaddrs[n] == NULL)
|
|
EXT(statp).nsaddrs[n] =
|
|
malloc(sizeof (struct sockaddr_in6));
|
|
if (EXT(statp).nsaddrs[n] != NULL) {
|
|
memset (mempcpy(EXT(statp).nsaddrs[n],
|
|
&statp->nsaddr_list[ns],
|
|
sizeof (struct sockaddr_in)),
|
|
'\0',
|
|
sizeof (struct sockaddr_in6)
|
|
- sizeof (struct sockaddr_in));
|
|
EXT(statp).nssocks[n] = -1;
|
|
n++;
|
|
}
|
|
}
|
|
EXT(statp).nsinit = 1;
|
|
}
|
|
|
|
/*
|
|
* Some resolvers want to even out the load on their nameservers.
|
|
* Note that RES_BLAST overrides RES_ROTATE.
|
|
*/
|
|
if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) &&
|
|
(statp->options & RES_BLAST) == 0) {
|
|
struct sockaddr_in6 *ina;
|
|
unsigned int map;
|
|
|
|
n = 0;
|
|
while (n < MAXNS && EXT(statp).nsmap[n] == MAXNS)
|
|
n++;
|
|
if (n < MAXNS) {
|
|
ina = EXT(statp).nsaddrs[n];
|
|
map = EXT(statp).nsmap[n];
|
|
for (;;) {
|
|
ns = n + 1;
|
|
while (ns < MAXNS
|
|
&& EXT(statp).nsmap[ns] == MAXNS)
|
|
ns++;
|
|
if (ns == MAXNS)
|
|
break;
|
|
EXT(statp).nsaddrs[n] = EXT(statp).nsaddrs[ns];
|
|
EXT(statp).nsmap[n] = EXT(statp).nsmap[ns];
|
|
n = ns;
|
|
}
|
|
EXT(statp).nsaddrs[n] = ina;
|
|
EXT(statp).nsmap[n] = map;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send request, RETRY times, or until successful.
|
|
*/
|
|
for (try = 0; try < statp->retry; try++) {
|
|
for (ns = 0; ns < MAXNS; ns++)
|
|
{
|
|
#ifdef DEBUG
|
|
char tmpbuf[40];
|
|
#endif
|
|
struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
|
|
|
|
if (nsap == NULL)
|
|
goto next_ns;
|
|
same_ns:
|
|
#ifdef USE_HOOKS
|
|
if (__glibc_unlikely (statp->qhook != NULL)) {
|
|
int done = 0, loops = 0;
|
|
|
|
do {
|
|
res_sendhookact act;
|
|
|
|
struct sockaddr_in *nsap4;
|
|
nsap4 = (struct sockaddr_in *) nsap;
|
|
act = (*statp->qhook)(&nsap4, &buf, &buflen,
|
|
ans, anssiz, &resplen);
|
|
nsap = (struct sockaddr_in6 *) nsap4;
|
|
switch (act) {
|
|
case res_goahead:
|
|
done = 1;
|
|
break;
|
|
case res_nextns:
|
|
__res_iclose(statp, false);
|
|
goto next_ns;
|
|
case res_done:
|
|
return (resplen);
|
|
case res_modified:
|
|
/* give the hook another try */
|
|
if (++loops < 42) /*doug adams*/
|
|
break;
|
|
/*FALLTHROUGH*/
|
|
case res_error:
|
|
/*FALLTHROUGH*/
|
|
default:
|
|
return (-1);
|
|
}
|
|
} while (!done);
|
|
}
|
|
#endif
|
|
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; Querying server (# %d) address = %s\n",
|
|
ns + 1, inet_ntop(nsap->sin6_family,
|
|
(nsap->sin6_family == AF_INET6
|
|
? &nsap->sin6_addr
|
|
: &((struct sockaddr_in *) nsap)->sin_addr),
|
|
tmpbuf, sizeof (tmpbuf))));
|
|
|
|
if (__glibc_unlikely (v_circuit)) {
|
|
/* Use VC; at most one attempt per server. */
|
|
try = statp->retry;
|
|
n = send_vc(statp, buf, buflen, buf2, buflen2,
|
|
&ans, &anssiz, &terrno,
|
|
ns, ansp, ansp2, nansp2, resplen2,
|
|
ansp2_malloced);
|
|
if (n < 0)
|
|
return (-1);
|
|
if (n == 0 && (buf2 == NULL || *resplen2 == 0))
|
|
goto next_ns;
|
|
} else {
|
|
/* Use datagrams. */
|
|
n = send_dg(statp, buf, buflen, buf2, buflen2,
|
|
&ans, &anssiz, &terrno,
|
|
ns, &v_circuit, &gotsomewhere, ansp,
|
|
ansp2, nansp2, resplen2, ansp2_malloced);
|
|
if (n < 0)
|
|
return (-1);
|
|
if (n == 0 && (buf2 == NULL || *resplen2 == 0))
|
|
goto next_ns;
|
|
if (v_circuit)
|
|
// XXX Check whether both requests failed or
|
|
// XXX whether one has been answered successfully
|
|
goto same_ns;
|
|
}
|
|
|
|
resplen = n;
|
|
|
|
Dprint((statp->options & RES_DEBUG) ||
|
|
((statp->pfcode & RES_PRF_REPLY) &&
|
|
(statp->pfcode & RES_PRF_HEAD1)),
|
|
(stdout, ";; got answer:\n"));
|
|
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, "%s", ""),
|
|
ans, (resplen > anssiz) ? anssiz : resplen);
|
|
if (buf2 != NULL) {
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, "%s", ""),
|
|
*ansp2, (*resplen2 > *nansp2) ? *nansp2 : *resplen2);
|
|
}
|
|
|
|
/*
|
|
* 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) == 0) ||
|
|
(statp->options & RES_STAYOPEN) == 0) {
|
|
__res_iclose(statp, false);
|
|
}
|
|
#ifdef USE_HOOKS
|
|
if (__glibc_unlikely (statp->rhook)) {
|
|
int done = 0, loops = 0;
|
|
|
|
do {
|
|
res_sendhookact act;
|
|
|
|
act = (*statp->rhook)((struct sockaddr_in *)
|
|
nsap, buf, buflen,
|
|
ans, anssiz, &resplen);
|
|
switch (act) {
|
|
case res_goahead:
|
|
case res_done:
|
|
done = 1;
|
|
break;
|
|
case res_nextns:
|
|
__res_iclose(statp, false);
|
|
goto next_ns;
|
|
case res_modified:
|
|
/* give the hook another try */
|
|
if (++loops < 42) /*doug adams*/
|
|
break;
|
|
/*FALLTHROUGH*/
|
|
case res_error:
|
|
/*FALLTHROUGH*/
|
|
default:
|
|
return (-1);
|
|
}
|
|
} while (!done);
|
|
|
|
}
|
|
#endif
|
|
return (resplen);
|
|
next_ns: ;
|
|
} /*foreach ns*/
|
|
} /*foreach retry*/
|
|
__res_iclose(statp, false);
|
|
if (!v_circuit) {
|
|
if (!gotsomewhere)
|
|
__set_errno (ECONNREFUSED); /* no nameservers found */
|
|
else
|
|
__set_errno (ETIMEDOUT); /* no answer obtained */
|
|
} else
|
|
__set_errno (terrno);
|
|
return (-1);
|
|
}
|
|
|
|
int
|
|
res_nsend(res_state statp,
|
|
const u_char *buf, int buflen, u_char *ans, int anssiz)
|
|
{
|
|
return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz,
|
|
NULL, NULL, NULL, NULL, NULL);
|
|
}
|
|
libresolv_hidden_def (res_nsend)
|
|
|
|
/* Private */
|
|
|
|
static int
|
|
send_vc(res_state statp,
|
|
const u_char *buf, int buflen, const u_char *buf2, int buflen2,
|
|
u_char **ansp, int *anssizp,
|
|
int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2,
|
|
int *resplen2, int *ansp2_malloced)
|
|
{
|
|
const HEADER *hp = (HEADER *) buf;
|
|
const HEADER *hp2 = (HEADER *) buf2;
|
|
u_char *ans = *ansp;
|
|
int orig_anssizp = *anssizp;
|
|
// XXX REMOVE
|
|
// int anssiz = *anssizp;
|
|
HEADER *anhp = (HEADER *) ans;
|
|
struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
|
|
int truncating, connreset, n;
|
|
/* On some architectures compiler might emit a warning indicating
|
|
'resplen' may be used uninitialized. However if buf2 == NULL
|
|
then this code won't be executed; if buf2 != NULL, then first
|
|
time round the loop recvresp1 and recvresp2 will be 0 so this
|
|
code won't be executed but "thisresplenp = &resplen;" followed
|
|
by "*thisresplenp = rlen;" will be executed so that subsequent
|
|
times round the loop resplen has been initialized. So this is
|
|
a false-positive.
|
|
*/
|
|
#if __GNUC_PREREQ (4, 7)
|
|
DIAG_PUSH_NEEDS_COMMENT;
|
|
DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
|
|
#endif
|
|
int resplen;
|
|
#if __GNUC_PREREQ (4, 7)
|
|
DIAG_POP_NEEDS_COMMENT;
|
|
#endif
|
|
struct iovec iov[4];
|
|
u_short len;
|
|
u_short len2;
|
|
u_char *cp;
|
|
|
|
if (resplen2 != NULL)
|
|
*resplen2 = 0;
|
|
connreset = 0;
|
|
same_ns:
|
|
truncating = 0;
|
|
|
|
/* Are we still talking to whom we want to talk to? */
|
|
if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
|
|
struct sockaddr_in6 peer;
|
|
socklen_t size = sizeof peer;
|
|
|
|
if (getpeername(statp->_vcsock,
|
|
(struct sockaddr *)&peer, &size) < 0 ||
|
|
!sock_eq(&peer, nsap)) {
|
|
__res_iclose(statp, false);
|
|
statp->_flags &= ~RES_F_VC;
|
|
}
|
|
}
|
|
|
|
if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) {
|
|
if (statp->_vcsock >= 0)
|
|
__res_iclose(statp, false);
|
|
|
|
statp->_vcsock = socket(nsap->sin6_family, SOCK_STREAM, 0);
|
|
if (statp->_vcsock < 0) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "socket(vc)", errno);
|
|
return (-1);
|
|
}
|
|
__set_errno (0);
|
|
if (connect(statp->_vcsock, (struct sockaddr *)nsap,
|
|
nsap->sin6_family == AF_INET
|
|
? sizeof (struct sockaddr_in)
|
|
: sizeof (struct sockaddr_in6)) < 0) {
|
|
*terrno = errno;
|
|
Aerror(statp, stderr, "connect/vc", errno,
|
|
(struct sockaddr *) nsap);
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
statp->_flags |= RES_F_VC;
|
|
}
|
|
|
|
/*
|
|
* Send length & message
|
|
*/
|
|
len = htons ((u_short) buflen);
|
|
evConsIovec(&len, INT16SZ, &iov[0]);
|
|
evConsIovec((void*)buf, buflen, &iov[1]);
|
|
int niov = 2;
|
|
ssize_t explen = INT16SZ + buflen;
|
|
if (buf2 != NULL) {
|
|
len2 = htons ((u_short) buflen2);
|
|
evConsIovec(&len2, INT16SZ, &iov[2]);
|
|
evConsIovec((void*)buf2, buflen2, &iov[3]);
|
|
niov = 4;
|
|
explen += INT16SZ + buflen2;
|
|
}
|
|
if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "write failed", errno);
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
/*
|
|
* Receive length & response
|
|
*/
|
|
int recvresp1 = 0;
|
|
int recvresp2 = buf2 == NULL;
|
|
uint16_t rlen16;
|
|
read_len:
|
|
cp = (u_char *)&rlen16;
|
|
len = sizeof(rlen16);
|
|
while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, cp,
|
|
(int)len))) > 0) {
|
|
cp += n;
|
|
if ((len -= n) <= 0)
|
|
break;
|
|
}
|
|
if (n <= 0) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "read failed", errno);
|
|
__res_iclose(statp, false);
|
|
/*
|
|
* 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;
|
|
goto same_ns;
|
|
}
|
|
return (0);
|
|
}
|
|
int rlen = ntohs (rlen16);
|
|
|
|
int *thisanssizp;
|
|
u_char **thisansp;
|
|
int *thisresplenp;
|
|
if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) {
|
|
thisanssizp = anssizp;
|
|
thisansp = anscp ?: ansp;
|
|
assert (anscp != NULL || ansp2 == NULL);
|
|
thisresplenp = &resplen;
|
|
} else {
|
|
if (*anssizp != MAXPACKET) {
|
|
/* No buffer allocated for the first
|
|
reply. We can try to use the rest
|
|
of the user-provided buffer. */
|
|
#if __GNUC_PREREQ (4, 7)
|
|
DIAG_PUSH_NEEDS_COMMENT;
|
|
DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
|
|
#endif
|
|
#if _STRING_ARCH_unaligned
|
|
*anssizp2 = orig_anssizp - resplen;
|
|
*ansp2 = *ansp + resplen;
|
|
#else
|
|
int aligned_resplen
|
|
= ((resplen + __alignof__ (HEADER) - 1)
|
|
& ~(__alignof__ (HEADER) - 1));
|
|
*anssizp2 = orig_anssizp - aligned_resplen;
|
|
*ansp2 = *ansp + aligned_resplen;
|
|
#endif
|
|
#if __GNUC_PREREQ (4, 7)
|
|
DIAG_POP_NEEDS_COMMENT;
|
|
#endif
|
|
} else {
|
|
/* The first reply did not fit into the
|
|
user-provided buffer. Maybe the second
|
|
answer will. */
|
|
*anssizp2 = orig_anssizp;
|
|
*ansp2 = *ansp;
|
|
}
|
|
|
|
thisanssizp = anssizp2;
|
|
thisansp = ansp2;
|
|
thisresplenp = resplen2;
|
|
}
|
|
anhp = (HEADER *) *thisansp;
|
|
|
|
*thisresplenp = rlen;
|
|
if (rlen > *thisanssizp) {
|
|
/* Yes, we test ANSCP here. If we have two buffers
|
|
both will be allocatable. */
|
|
if (__glibc_likely (anscp != NULL)) {
|
|
u_char *newp = malloc (MAXPACKET);
|
|
if (newp == NULL) {
|
|
*terrno = ENOMEM;
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
*thisanssizp = MAXPACKET;
|
|
*thisansp = newp;
|
|
if (thisansp == ansp2)
|
|
*ansp2_malloced = 1;
|
|
anhp = (HEADER *) newp;
|
|
len = rlen;
|
|
} else {
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; response truncated\n")
|
|
);
|
|
truncating = 1;
|
|
len = *thisanssizp;
|
|
}
|
|
} else
|
|
len = rlen;
|
|
|
|
if (__glibc_unlikely (len < HFIXEDSZ)) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n", len));
|
|
*terrno = EMSGSIZE;
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
|
|
cp = *thisansp;
|
|
while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){
|
|
cp += n;
|
|
len -= n;
|
|
}
|
|
if (__glibc_unlikely (n <= 0)) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "read(vc)", errno);
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
if (__glibc_unlikely (truncating)) {
|
|
/*
|
|
* Flush rest of answer so connection stays in synch.
|
|
*/
|
|
anhp->tc = 1;
|
|
len = rlen - *thisanssizp;
|
|
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 application 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 ((recvresp1 || hp->id != anhp->id)
|
|
&& (recvresp2 || hp2->id != anhp->id)) {
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; old answer (unexpected):\n"),
|
|
*thisansp,
|
|
(rlen > *thisanssizp) ? *thisanssizp: rlen);
|
|
goto read_len;
|
|
}
|
|
|
|
/* Mark which reply we received. */
|
|
if (recvresp1 == 0 && hp->id == anhp->id)
|
|
recvresp1 = 1;
|
|
else
|
|
recvresp2 = 1;
|
|
/* Repeat waiting if we have a second answer to arrive. */
|
|
if ((recvresp1 & recvresp2) == 0)
|
|
goto read_len;
|
|
|
|
/*
|
|
* All is well, or the error is fatal. Signal that the
|
|
* next nameserver ought not be tried.
|
|
*/
|
|
return resplen;
|
|
}
|
|
|
|
static int
|
|
reopen (res_state statp, int *terrno, int ns)
|
|
{
|
|
if (EXT(statp).nssocks[ns] == -1) {
|
|
struct sockaddr *nsap
|
|
= (struct sockaddr *) EXT(statp).nsaddrs[ns];
|
|
socklen_t slen;
|
|
|
|
/* only try IPv6 if IPv6 NS and if not failed before */
|
|
if (nsap->sa_family == AF_INET6 && !statp->ipv6_unavail) {
|
|
if (__glibc_likely (__have_o_nonblock >= 0)) {
|
|
EXT(statp).nssocks[ns] =
|
|
socket(PF_INET6, SOCK_DGRAM|SOCK_NONBLOCK,
|
|
0);
|
|
#ifndef __ASSUME_SOCK_CLOEXEC
|
|
if (__have_o_nonblock == 0)
|
|
__have_o_nonblock
|
|
= (EXT(statp).nssocks[ns] == -1
|
|
&& errno == EINVAL ? -1 : 1);
|
|
#endif
|
|
}
|
|
if (__glibc_unlikely (__have_o_nonblock < 0))
|
|
EXT(statp).nssocks[ns] =
|
|
socket(PF_INET6, SOCK_DGRAM, 0);
|
|
if (EXT(statp).nssocks[ns] < 0)
|
|
statp->ipv6_unavail = errno == EAFNOSUPPORT;
|
|
slen = sizeof (struct sockaddr_in6);
|
|
} else if (nsap->sa_family == AF_INET) {
|
|
if (__glibc_likely (__have_o_nonblock >= 0)) {
|
|
EXT(statp).nssocks[ns]
|
|
= socket(PF_INET, SOCK_DGRAM|SOCK_NONBLOCK,
|
|
0);
|
|
#ifndef __ASSUME_SOCK_CLOEXEC
|
|
if (__have_o_nonblock == 0)
|
|
__have_o_nonblock
|
|
= (EXT(statp).nssocks[ns] == -1
|
|
&& errno == EINVAL ? -1 : 1);
|
|
#endif
|
|
}
|
|
if (__glibc_unlikely (__have_o_nonblock < 0))
|
|
EXT(statp).nssocks[ns]
|
|
= socket(PF_INET, SOCK_DGRAM, 0);
|
|
slen = sizeof (struct sockaddr_in);
|
|
}
|
|
if (EXT(statp).nssocks[ns] < 0) {
|
|
*terrno = errno;
|
|
Perror(statp, stderr, "socket(dg)", errno);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* On a 4.3BSD+ machine (client and server,
|
|
* actually), sending to a nameserver datagram
|
|
* port with no nameserver will cause an
|
|
* ICMP port unreachable message to be returned.
|
|
* If our datagram socket is "connected" to the
|
|
* server, we get an ECONNREFUSED error on the next
|
|
* socket operation, and select returns if the
|
|
* error message is received. We can thus detect
|
|
* the absence of a nameserver without timing out.
|
|
*/
|
|
if (connect(EXT(statp).nssocks[ns], nsap, slen) < 0) {
|
|
Aerror(statp, stderr, "connect(dg)", errno, nsap);
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
if (__glibc_unlikely (__have_o_nonblock < 0)) {
|
|
/* Make socket non-blocking. */
|
|
int fl = __fcntl (EXT(statp).nssocks[ns], F_GETFL);
|
|
if (fl != -1)
|
|
__fcntl (EXT(statp).nssocks[ns], F_SETFL,
|
|
fl | O_NONBLOCK);
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; new DG socket\n"))
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
send_dg(res_state statp,
|
|
const u_char *buf, int buflen, const u_char *buf2, int buflen2,
|
|
u_char **ansp, int *anssizp,
|
|
int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp,
|
|
u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced)
|
|
{
|
|
const HEADER *hp = (HEADER *) buf;
|
|
const HEADER *hp2 = (HEADER *) buf2;
|
|
u_char *ans = *ansp;
|
|
int orig_anssizp = *anssizp;
|
|
struct timespec now, timeout, finish;
|
|
struct pollfd pfd[1];
|
|
int ptimeout;
|
|
struct sockaddr_in6 from;
|
|
int resplen = 0;
|
|
int n;
|
|
|
|
/*
|
|
* Compute time for the total operation.
|
|
*/
|
|
int seconds = (statp->retrans << ns);
|
|
if (ns > 0)
|
|
seconds /= statp->nscount;
|
|
if (seconds <= 0)
|
|
seconds = 1;
|
|
bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0;
|
|
bool single_request = (((statp->options & RES_SNGLKUP) != 0)
|
|
| single_request_reopen);
|
|
int save_gotsomewhere = *gotsomewhere;
|
|
|
|
int retval;
|
|
retry_reopen:
|
|
retval = reopen (statp, terrno, ns);
|
|
if (retval <= 0)
|
|
return retval;
|
|
retry:
|
|
evNowTime(&now);
|
|
evConsTime(&timeout, seconds, 0);
|
|
evAddTime(&finish, &now, &timeout);
|
|
int need_recompute = 0;
|
|
int nwritten = 0;
|
|
int recvresp1 = 0;
|
|
int recvresp2 = buf2 == NULL;
|
|
pfd[0].fd = EXT(statp).nssocks[ns];
|
|
pfd[0].events = POLLOUT;
|
|
if (resplen2 != NULL)
|
|
*resplen2 = 0;
|
|
wait:
|
|
if (need_recompute) {
|
|
recompute_resend:
|
|
evNowTime(&now);
|
|
if (evCmpTime(finish, now) <= 0) {
|
|
poll_err_out:
|
|
Perror(statp, stderr, "poll", errno);
|
|
err_out:
|
|
__res_iclose(statp, false);
|
|
return (0);
|
|
}
|
|
evSubTime(&timeout, &finish, &now);
|
|
need_recompute = 0;
|
|
}
|
|
/* Convert struct timespec in milliseconds. */
|
|
ptimeout = timeout.tv_sec * 1000 + timeout.tv_nsec / 1000000;
|
|
|
|
n = 0;
|
|
if (nwritten == 0)
|
|
n = __poll (pfd, 1, 0);
|
|
if (__glibc_unlikely (n == 0)) {
|
|
n = __poll (pfd, 1, ptimeout);
|
|
need_recompute = 1;
|
|
}
|
|
if (n == 0) {
|
|
Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n"));
|
|
if (resplen > 1 && (recvresp1 || (buf2 != NULL && recvresp2)))
|
|
{
|
|
/* There are quite a few broken name servers out
|
|
there which don't handle two outstanding
|
|
requests from the same source. There are also
|
|
broken firewall settings. If we time out after
|
|
having received one answer switch to the mode
|
|
where we send the second request only once we
|
|
have received the first answer. */
|
|
if (!single_request)
|
|
{
|
|
statp->options |= RES_SNGLKUP;
|
|
single_request = true;
|
|
*gotsomewhere = save_gotsomewhere;
|
|
goto retry;
|
|
}
|
|
else if (!single_request_reopen)
|
|
{
|
|
statp->options |= RES_SNGLKUPREOP;
|
|
single_request_reopen = true;
|
|
*gotsomewhere = save_gotsomewhere;
|
|
__res_iclose (statp, false);
|
|
goto retry_reopen;
|
|
}
|
|
|
|
*resplen2 = 1;
|
|
return resplen;
|
|
}
|
|
|
|
*gotsomewhere = 1;
|
|
return (0);
|
|
}
|
|
if (n < 0) {
|
|
if (errno == EINTR)
|
|
goto recompute_resend;
|
|
|
|
goto poll_err_out;
|
|
}
|
|
__set_errno (0);
|
|
if (pfd[0].revents & POLLOUT) {
|
|
#ifndef __ASSUME_SENDMMSG
|
|
static int have_sendmmsg;
|
|
#else
|
|
# define have_sendmmsg 1
|
|
#endif
|
|
if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL
|
|
&& !single_request)
|
|
{
|
|
struct iovec iov[2];
|
|
struct mmsghdr reqs[2];
|
|
reqs[0].msg_hdr.msg_name = NULL;
|
|
reqs[0].msg_hdr.msg_namelen = 0;
|
|
reqs[0].msg_hdr.msg_iov = &iov[0];
|
|
reqs[0].msg_hdr.msg_iovlen = 1;
|
|
iov[0].iov_base = (void *) buf;
|
|
iov[0].iov_len = buflen;
|
|
reqs[0].msg_hdr.msg_control = NULL;
|
|
reqs[0].msg_hdr.msg_controllen = 0;
|
|
|
|
reqs[1].msg_hdr.msg_name = NULL;
|
|
reqs[1].msg_hdr.msg_namelen = 0;
|
|
reqs[1].msg_hdr.msg_iov = &iov[1];
|
|
reqs[1].msg_hdr.msg_iovlen = 1;
|
|
iov[1].iov_base = (void *) buf2;
|
|
iov[1].iov_len = buflen2;
|
|
reqs[1].msg_hdr.msg_control = NULL;
|
|
reqs[1].msg_hdr.msg_controllen = 0;
|
|
|
|
int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL);
|
|
if (__glibc_likely (ndg == 2))
|
|
{
|
|
if (reqs[0].msg_len != buflen
|
|
|| reqs[1].msg_len != buflen2)
|
|
goto fail_sendmmsg;
|
|
|
|
pfd[0].events = POLLIN;
|
|
nwritten += 2;
|
|
}
|
|
else if (ndg == 1 && reqs[0].msg_len == buflen)
|
|
goto just_one;
|
|
else if (ndg < 0 && (errno == EINTR || errno == EAGAIN))
|
|
goto recompute_resend;
|
|
else
|
|
{
|
|
#ifndef __ASSUME_SENDMMSG
|
|
if (__glibc_unlikely (have_sendmmsg == 0))
|
|
{
|
|
if (ndg < 0 && errno == ENOSYS)
|
|
{
|
|
have_sendmmsg = -1;
|
|
goto try_send;
|
|
}
|
|
have_sendmmsg = 1;
|
|
}
|
|
#endif
|
|
|
|
fail_sendmmsg:
|
|
Perror(statp, stderr, "sendmmsg", errno);
|
|
goto err_out;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ssize_t sr;
|
|
#ifndef __ASSUME_SENDMMSG
|
|
try_send:
|
|
#endif
|
|
if (nwritten != 0)
|
|
sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL);
|
|
else
|
|
sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL);
|
|
|
|
if (sr != (nwritten != 0 ? buflen2 : buflen)) {
|
|
if (errno == EINTR || errno == EAGAIN)
|
|
goto recompute_resend;
|
|
Perror(statp, stderr, "send", errno);
|
|
goto err_out;
|
|
}
|
|
just_one:
|
|
if (nwritten != 0 || buf2 == NULL || single_request)
|
|
pfd[0].events = POLLIN;
|
|
else
|
|
pfd[0].events = POLLIN | POLLOUT;
|
|
++nwritten;
|
|
}
|
|
goto wait;
|
|
} else if (pfd[0].revents & POLLIN) {
|
|
int *thisanssizp;
|
|
u_char **thisansp;
|
|
int *thisresplenp;
|
|
|
|
if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) {
|
|
thisanssizp = anssizp;
|
|
thisansp = anscp ?: ansp;
|
|
assert (anscp != NULL || ansp2 == NULL);
|
|
thisresplenp = &resplen;
|
|
} else {
|
|
if (*anssizp != MAXPACKET) {
|
|
/* No buffer allocated for the first
|
|
reply. We can try to use the rest
|
|
of the user-provided buffer. */
|
|
#if _STRING_ARCH_unaligned
|
|
*anssizp2 = orig_anssizp - resplen;
|
|
*ansp2 = *ansp + resplen;
|
|
#else
|
|
int aligned_resplen
|
|
= ((resplen + __alignof__ (HEADER) - 1)
|
|
& ~(__alignof__ (HEADER) - 1));
|
|
*anssizp2 = orig_anssizp - aligned_resplen;
|
|
*ansp2 = *ansp + aligned_resplen;
|
|
#endif
|
|
} else {
|
|
/* The first reply did not fit into the
|
|
user-provided buffer. Maybe the second
|
|
answer will. */
|
|
*anssizp2 = orig_anssizp;
|
|
*ansp2 = *ansp;
|
|
}
|
|
|
|
thisanssizp = anssizp2;
|
|
thisansp = ansp2;
|
|
thisresplenp = resplen2;
|
|
}
|
|
|
|
if (*thisanssizp < MAXPACKET
|
|
/* Yes, we test ANSCP here. If we have two buffers
|
|
both will be allocatable. */
|
|
&& anscp
|
|
#ifdef FIONREAD
|
|
&& (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0
|
|
|| *thisanssizp < *thisresplenp)
|
|
#endif
|
|
) {
|
|
u_char *newp = malloc (MAXPACKET);
|
|
if (newp != NULL) {
|
|
*anssizp = MAXPACKET;
|
|
*thisansp = ans = newp;
|
|
if (thisansp == ansp2)
|
|
*ansp2_malloced = 1;
|
|
}
|
|
}
|
|
HEADER *anhp = (HEADER *) *thisansp;
|
|
socklen_t fromlen = sizeof(struct sockaddr_in6);
|
|
assert (sizeof(from) <= fromlen);
|
|
*thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp,
|
|
*thisanssizp, 0,
|
|
(struct sockaddr *)&from, &fromlen);
|
|
if (__glibc_unlikely (*thisresplenp <= 0)) {
|
|
if (errno == EINTR || errno == EAGAIN) {
|
|
need_recompute = 1;
|
|
goto wait;
|
|
}
|
|
Perror(statp, stderr, "recvfrom", errno);
|
|
goto err_out;
|
|
}
|
|
*gotsomewhere = 1;
|
|
if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n",
|
|
*thisresplenp));
|
|
*terrno = EMSGSIZE;
|
|
goto err_out;
|
|
}
|
|
if ((recvresp1 || hp->id != anhp->id)
|
|
&& (recvresp2 || hp2->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"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
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"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
goto wait;
|
|
}
|
|
#ifdef RES_USE_EDNS0
|
|
if (anhp->rcode == FORMERR
|
|
&& (statp->options & RES_USE_EDNS0) != 0U) {
|
|
/*
|
|
* Do not retry if the server does not understand
|
|
* EDNS0. The case has to be captured here, as
|
|
* FORMERR packet do not carry query section, hence
|
|
* res_queriesmatch() returns 0.
|
|
*/
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout,
|
|
"server rejected query with EDNS0:\n"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
/* record the error */
|
|
statp->_flags |= RES_F_EDNS0ERR;
|
|
goto err_out;
|
|
}
|
|
#endif
|
|
if (!(statp->options & RES_INSECURE2)
|
|
&& (recvresp1 || !res_queriesmatch(buf, buf + buflen,
|
|
*thisansp,
|
|
*thisansp
|
|
+ *thisanssizp))
|
|
&& (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2,
|
|
*thisansp,
|
|
*thisansp
|
|
+ *thisanssizp))) {
|
|
/*
|
|
* 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"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
goto wait;
|
|
}
|
|
if (anhp->rcode == SERVFAIL ||
|
|
anhp->rcode == NOTIMP ||
|
|
anhp->rcode == REFUSED) {
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout, "server rejected query:\n"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
|
|
next_ns:
|
|
if (recvresp1 || (buf2 != NULL && recvresp2)) {
|
|
*resplen2 = 0;
|
|
return resplen;
|
|
}
|
|
if (buf2 != NULL)
|
|
{
|
|
/* No data from the first reply. */
|
|
resplen = 0;
|
|
/* We are waiting for a possible second reply. */
|
|
if (hp->id == anhp->id)
|
|
recvresp1 = 1;
|
|
else
|
|
recvresp2 = 1;
|
|
|
|
goto wait;
|
|
}
|
|
|
|
__res_iclose(statp, false);
|
|
/* don't retry if called from dig */
|
|
if (!statp->pfcode)
|
|
return (0);
|
|
}
|
|
if (anhp->rcode == NOERROR && anhp->ancount == 0
|
|
&& anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) {
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout, "referred query:\n"),
|
|
*thisansp,
|
|
(*thisresplenp > *thisanssizp)
|
|
? *thisanssizp : *thisresplenp);
|
|
goto next_ns;
|
|
}
|
|
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_iclose(statp, false);
|
|
// XXX if we have received one reply we could
|
|
// XXX use it and not repeat it over TCP...
|
|
return (1);
|
|
}
|
|
/* Mark which reply we received. */
|
|
if (recvresp1 == 0 && hp->id == anhp->id)
|
|
recvresp1 = 1;
|
|
else
|
|
recvresp2 = 1;
|
|
/* Repeat waiting if we have a second answer to arrive. */
|
|
if ((recvresp1 & recvresp2) == 0) {
|
|
if (single_request) {
|
|
pfd[0].events = POLLOUT;
|
|
if (single_request_reopen) {
|
|
__res_iclose (statp, false);
|
|
retval = reopen (statp, terrno, ns);
|
|
if (retval <= 0)
|
|
return retval;
|
|
pfd[0].fd = EXT(statp).nssocks[ns];
|
|
}
|
|
}
|
|
goto wait;
|
|
}
|
|
/*
|
|
* All is well, or the error is fatal. Signal that the
|
|
* next nameserver ought not be tried.
|
|
*/
|
|
return (resplen);
|
|
} else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
/* Something went wrong. We can stop trying. */
|
|
goto err_out;
|
|
}
|
|
else {
|
|
/* poll should not have returned > 0 in this case. */
|
|
abort ();
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
static void
|
|
Aerror(const res_state statp, FILE *file, const char *string, int error,
|
|
const struct sockaddr *address)
|
|
{
|
|
int save = errno;
|
|
|
|
if ((statp->options & RES_DEBUG) != 0) {
|
|
char tmp[sizeof "xxxx.xxxx.xxxx.255.255.255.255"];
|
|
|
|
fprintf(file, "res_send: %s ([%s].%u): %s\n",
|
|
string,
|
|
(address->sa_family == AF_INET
|
|
? inet_ntop(address->sa_family,
|
|
&((const struct sockaddr_in *) address)->sin_addr,
|
|
tmp, sizeof tmp)
|
|
: inet_ntop(address->sa_family,
|
|
&((const struct sockaddr_in6 *) address)->sin6_addr,
|
|
tmp, sizeof tmp)),
|
|
(address->sa_family == AF_INET
|
|
? ntohs(((struct sockaddr_in *) address)->sin_port)
|
|
: address->sa_family == AF_INET6
|
|
? ntohs(((struct sockaddr_in6 *) address)->sin6_port)
|
|
: 0),
|
|
strerror(error));
|
|
}
|
|
__set_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));
|
|
__set_errno (save);
|
|
}
|
|
#endif
|
|
|
|
static int
|
|
sock_eq(struct sockaddr_in6 *a1, struct sockaddr_in6 *a2) {
|
|
if (a1->sin6_family == a2->sin6_family) {
|
|
if (a1->sin6_family == AF_INET)
|
|
return ((((struct sockaddr_in *)a1)->sin_port ==
|
|
((struct sockaddr_in *)a2)->sin_port) &&
|
|
(((struct sockaddr_in *)a1)->sin_addr.s_addr ==
|
|
((struct sockaddr_in *)a2)->sin_addr.s_addr));
|
|
else
|
|
return ((a1->sin6_port == a2->sin6_port) &&
|
|
!memcmp(&a1->sin6_addr, &a2->sin6_addr,
|
|
sizeof (struct in6_addr)));
|
|
}
|
|
if (a1->sin6_family == AF_INET) {
|
|
struct sockaddr_in6 *sap = a1;
|
|
a1 = a2;
|
|
a2 = sap;
|
|
} /* assumes that AF_INET and AF_INET6 are the only possibilities */
|
|
return ((a1->sin6_port == ((struct sockaddr_in *)a2)->sin_port) &&
|
|
IN6_IS_ADDR_V4MAPPED(&a1->sin6_addr) &&
|
|
(a1->sin6_addr.s6_addr32[3] ==
|
|
((struct sockaddr_in *)a2)->sin_addr.s_addr));
|
|
}
|