413 lines
11 KiB
C
413 lines
11 KiB
C
/*
|
||
* ++Copyright++ 1985, 1989
|
||
* -
|
||
* Copyright (c) 1985, 1989
|
||
* The Regents of the University of California. All rights reserved.
|
||
*
|
||
* Redistribution and use in source and binary forms, with or without
|
||
* modification, are permitted provided that the following conditions
|
||
* are met:
|
||
* 1. Redistributions of source code must retain the above copyright
|
||
* notice, this list of conditions and the following disclaimer.
|
||
* 2. Redistributions in binary form must reproduce the above copyright
|
||
* notice, this list of conditions and the following disclaimer in the
|
||
* documentation and/or other materials provided with the distribution.
|
||
* 3. All advertising materials mentioning features or use of this software
|
||
* must display the following acknowledgement:
|
||
* This product includes software developed by the University of
|
||
* California, Berkeley and its contributors.
|
||
* 4. Neither the name of the University nor the names of its contributors
|
||
* may be used to endorse or promote products derived from this software
|
||
* without specific prior written permission.
|
||
*
|
||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
* SUCH DAMAGE.
|
||
* -
|
||
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
|
||
*
|
||
* Permission to use, copy, modify, and distribute this software for any
|
||
* purpose with or without fee is hereby granted, provided that the above
|
||
* copyright notice and this permission notice appear in all copies, and that
|
||
* the name of Digital Equipment Corporation not be used in advertising or
|
||
* publicity pertaining to distribution of the document or software without
|
||
* specific, written prior permission.
|
||
*
|
||
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
|
||
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
|
||
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
|
||
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
||
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
||
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
||
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
||
* SOFTWARE.
|
||
* -
|
||
* --Copyright--
|
||
*/
|
||
|
||
#ifndef lint
|
||
static char sccsid[] = "@(#)send.c 5.18 (Berkeley) 3/2/91";
|
||
static char rcsid[] = "$Id: send.c,v 8.1 1994/12/15 06:24:31 vixie Exp $";
|
||
#endif /* not lint */
|
||
|
||
/*
|
||
******************************************************************************
|
||
*
|
||
* send.c --
|
||
*
|
||
* Routine to send request packets to a name server.
|
||
*
|
||
* Based on "@(#)res_send.c 6.25 (Berkeley) 6/1/90".
|
||
*
|
||
******************************************************************************
|
||
*/
|
||
|
||
|
||
/*
|
||
* Send query to name server and wait for reply.
|
||
*/
|
||
|
||
#include <sys/param.h>
|
||
#include <sys/time.h>
|
||
#include <sys/socket.h>
|
||
#include <sys/uio.h>
|
||
#include <netinet/in.h>
|
||
#include <stdio.h>
|
||
#include <errno.h>
|
||
#include <arpa/nameser.h>
|
||
#include <arpa/inet.h>
|
||
#include <resolv.h>
|
||
#include "res.h"
|
||
#include "../../conf/portability.h"
|
||
|
||
static int s = -1; /* socket used for communications */
|
||
|
||
|
||
#ifndef FD_SET
|
||
#define NFDBITS 32
|
||
#define FD_SETSIZE 32
|
||
#define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
|
||
#define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
|
||
#define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
|
||
#define FD_ZERO(p) bzero((char *)(p), sizeof(*(p)))
|
||
#endif
|
||
|
||
|
||
|
||
unsigned short nsport = NAMESERVER_PORT;
|
||
|
||
|
||
|
||
/*
|
||
******************************************************************************
|
||
*
|
||
* SendRequest --
|
||
*
|
||
* Sends a request packet to a name server whose address
|
||
* is specified by the first argument and returns with
|
||
* the answer packet.
|
||
*
|
||
* Results:
|
||
* SUCCESS - the request was sent and an answer
|
||
* was received.
|
||
* TIME_OUT - the virtual circuit connection timed-out
|
||
* or a reply to a datagram wasn't received.
|
||
*
|
||
*
|
||
******************************************************************************
|
||
*/
|
||
|
||
int
|
||
SendRequest(nsAddrPtr, buf, buflen, answer, anslen, trueLenPtr)
|
||
struct in_addr *nsAddrPtr;
|
||
char *buf;
|
||
int buflen;
|
||
char *answer;
|
||
u_int anslen;
|
||
int *trueLenPtr;
|
||
{
|
||
register int n;
|
||
int try, v_circuit, resplen;
|
||
int gotsomewhere = 0, connected = 0;
|
||
int connreset = 0;
|
||
u_short id, len;
|
||
char *cp;
|
||
fd_set dsmask;
|
||
struct timeval timeout;
|
||
HEADER *hp = (HEADER *) buf;
|
||
HEADER *anhp = (HEADER *) answer;
|
||
struct iovec iov[2];
|
||
int terrno = ETIMEDOUT;
|
||
char junk[512];
|
||
struct sockaddr_in sin;
|
||
|
||
if (_res.options & RES_DEBUG2) {
|
||
printf("------------\nSendRequest(), len %d\n", buflen);
|
||
Print_query(buf, buf+buflen, 1);
|
||
}
|
||
sin.sin_family = AF_INET;
|
||
sin.sin_port = htons(nsport);
|
||
sin.sin_addr = *nsAddrPtr;
|
||
v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
|
||
id = hp->id;
|
||
/*
|
||
* Send request, RETRY times, or until successful
|
||
*/
|
||
for (try = 0; try < _res.retry; try++) {
|
||
usevc:
|
||
if (v_circuit) {
|
||
int truncated = 0;
|
||
|
||
/*
|
||
* Use virtual circuit;
|
||
* at most one attempt per server.
|
||
*/
|
||
try = _res.retry;
|
||
if (s < 0) {
|
||
s = socket(AF_INET, SOCK_STREAM, 0);
|
||
if (s < 0) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("socket (vc) failed");
|
||
continue;
|
||
}
|
||
if (connect(s, (struct sockaddr *)&sin,
|
||
sizeof(struct sockaddr)) < 0) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("connect failed");
|
||
(void) close(s);
|
||
s = -1;
|
||
continue;
|
||
}
|
||
}
|
||
/*
|
||
* Send length & message
|
||
*/
|
||
__putshort(buflen, (u_char *)&len);
|
||
iov[0].iov_base = (caddr_t)&len;
|
||
iov[0].iov_len = INT16SZ;
|
||
iov[1].iov_base = buf;
|
||
iov[1].iov_len = buflen;
|
||
if (writev(s, iov, 2) != INT16SZ + buflen) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("write failed");
|
||
(void) close(s);
|
||
s = -1;
|
||
continue;
|
||
}
|
||
/*
|
||
* Receive length & response
|
||
*/
|
||
cp = answer;
|
||
len = INT16SZ;
|
||
while ((n = read(s, (char *)cp, (int)len)) > 0) {
|
||
cp += n;
|
||
if ((len -= n) <= 0)
|
||
break;
|
||
}
|
||
if (n <= 0) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("read failed");
|
||
(void) close(s);
|
||
s = -1;
|
||
/*
|
||
* 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;
|
||
}
|
||
continue;
|
||
}
|
||
cp = answer;
|
||
if ((resplen = _getshort((u_char*)cp)) > anslen) {
|
||
if (_res.options & RES_DEBUG)
|
||
fprintf(stderr, "response truncated\n");
|
||
len = anslen;
|
||
truncated = 1;
|
||
} else
|
||
len = resplen;
|
||
while (len != 0 &&
|
||
(n = read(s, (char *)cp, (int)len)) > 0) {
|
||
cp += n;
|
||
len -= n;
|
||
}
|
||
if (n <= 0) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("read failed");
|
||
(void) close(s);
|
||
s = -1;
|
||
continue;
|
||
}
|
||
if (truncated) {
|
||
/*
|
||
* Flush rest of answer
|
||
* so connection stays in synch.
|
||
*/
|
||
anhp->tc = 1;
|
||
len = resplen - anslen;
|
||
while (len != 0) {
|
||
n = (len > sizeof(junk) ?
|
||
sizeof(junk) : len);
|
||
if ((n = read(s, junk, n)) > 0)
|
||
len -= n;
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
} else {
|
||
/*
|
||
* Use datagrams.
|
||
*/
|
||
if (s < 0) {
|
||
s = socket(AF_INET, SOCK_DGRAM, 0);
|
||
if (s < 0) {
|
||
terrno = errno;
|
||
if (_res.options & RES_DEBUG)
|
||
perror("socket (dg) failed");
|
||
continue;
|
||
}
|
||
}
|
||
#if BSD >= 43
|
||
if (connected == 0) {
|
||
if (connect(s, (struct sockaddr *)&sin,
|
||
sizeof(struct sockaddr)) < 0) {
|
||
if (_res.options & RES_DEBUG)
|
||
perror("connect");
|
||
continue;
|
||
}
|
||
connected = 1;
|
||
}
|
||
if (send(s, buf, buflen, 0) != buflen) {
|
||
if (_res.options & RES_DEBUG)
|
||
perror("send");
|
||
continue;
|
||
}
|
||
#else /* BSD */
|
||
if (sendto(s, buf, buflen, 0,
|
||
(struct sockaddr *) &sin,
|
||
sizeof(sin)) != buflen) {
|
||
if (_res.options & RES_DEBUG)
|
||
perror("sendto");
|
||
continue;
|
||
}
|
||
#endif
|
||
|
||
/*
|
||
* Wait for reply
|
||
*/
|
||
timeout.tv_sec = (_res.retrans << try);
|
||
if (timeout.tv_sec <= 0)
|
||
timeout.tv_sec = 1;
|
||
timeout.tv_usec = 0;
|
||
wait:
|
||
FD_ZERO(&dsmask);
|
||
FD_SET(s, &dsmask);
|
||
n = select(s+1, &dsmask, (fd_set *)NULL,
|
||
(fd_set *)NULL, &timeout);
|
||
if (n < 0) {
|
||
if (_res.options & RES_DEBUG)
|
||
perror("select");
|
||
continue;
|
||
}
|
||
if (n == 0) {
|
||
/*
|
||
* timeout
|
||
*/
|
||
if (_res.options & RES_DEBUG)
|
||
printf("timeout (%d secs)\n",
|
||
timeout.tv_sec);
|
||
#if BSD >= 43
|
||
gotsomewhere = 1;
|
||
#endif
|
||
continue;
|
||
}
|
||
if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
|
||
if (_res.options & RES_DEBUG)
|
||
perror("recvfrom");
|
||
continue;
|
||
}
|
||
gotsomewhere = 1;
|
||
if (id != anhp->id) {
|
||
/*
|
||
* response from old query, ignore it
|
||
*/
|
||
if (_res.options & RES_DEBUG2) {
|
||
printf("------------\nOld answer:\n");
|
||
Print_query(answer, answer+resplen, 1);
|
||
}
|
||
goto wait;
|
||
}
|
||
if (!(_res.options & RES_IGNTC) && anhp->tc) {
|
||
/*
|
||
* get rest of answer;
|
||
* use TCP with same server.
|
||
*/
|
||
if (_res.options & RES_DEBUG)
|
||
printf("truncated answer\n");
|
||
(void) close(s);
|
||
s = -1;
|
||
v_circuit = 1;
|
||
goto usevc;
|
||
}
|
||
}
|
||
if (_res.options & RES_DEBUG) {
|
||
if (_res.options & RES_DEBUG2)
|
||
printf("------------\nGot answer (%d bytes):\n",
|
||
resplen);
|
||
else
|
||
printf("------------\nGot answer:\n");
|
||
Print_query(answer, answer+resplen, 1);
|
||
}
|
||
(void) close(s);
|
||
s = -1;
|
||
*trueLenPtr = resplen;
|
||
return (SUCCESS);
|
||
}
|
||
if (s >= 0) {
|
||
(void) close(s);
|
||
s = -1;
|
||
}
|
||
if (v_circuit == 0)
|
||
if (gotsomewhere == 0)
|
||
return NO_RESPONSE; /* no nameservers found */
|
||
else
|
||
return TIME_OUT; /* no answer obtained */
|
||
else
|
||
if (errno == ECONNREFUSED)
|
||
return NO_RESPONSE;
|
||
else
|
||
return ERROR;
|
||
}
|
||
|
||
/*
|
||
* This routine is for closing the socket if a virtual circuit is used and
|
||
* the program wants to close it.
|
||
*
|
||
* Called from the interrupt handler.
|
||
*/
|
||
SendRequest_close()
|
||
{
|
||
if (s != -1) {
|
||
(void) close(s);
|
||
s = -1;
|
||
}
|
||
}
|