[unix-history] / usr / src / usr.sbin / named / tools / nslookup / send.c

/*
 * Copyright (c) 1985, 1989 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.
 */

#ifndef lint
static char sccsid[] = "@(#)send.c	5.18 (Berkeley) 3/2/91";
#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"

extern int errno;

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

#define SR 1		/* SendRequest style */

#ifndef DEBUG
#define DEBUG
#endif

unsigned short nsport = NAMESERVER_PORT;


\f
/*
 *******************************************************************************
 *
 *   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, ns;
	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];

#if SR
	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;
#else
#ifdef DEBUG
	if (_res.options & RES_DEBUG) {
		printf("res_send()\n");
		p_query(buf);
	}
#endif DEBUG
	if (!(_res.options & RES_INIT))
		if (res_init() == -1) {
			return(-1);
		}
#endif /* SR */
	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++) {
#if !SR
	   for (ns = 0; ns < _res.nscount; ns++) {
#ifdef DEBUG
		if (_res.options & RES_DEBUG)
			printf("Querying server (# %d) address = %s\n", ns+1,
			      inet_ntoa(_res.nsaddr_list[ns].sin_addr));
#endif DEBUG
#endif /* !SR */
	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;
#ifdef DEBUG
					if (_res.options & RES_DEBUG)
					    perror("socket (vc) failed");
#endif DEBUG
					continue;
				}
#if SR
				if (connect(s, (struct sockaddr *)&sin,
#else
				if (connect(s,
				    (struct sockaddr *)&(_res.nsaddr_list[ns]),
#endif
				   sizeof(struct sockaddr)) < 0) {
					terrno = errno;
#ifdef DEBUG
					if (_res.options & RES_DEBUG)
					    perror("connect failed");
#endif DEBUG
					(void) close(s);
					s = -1;
					continue;
				}
			}
			/*
			 * Send length & message
			 */
			len = htons((u_short)buflen);
			iov[0].iov_base = (caddr_t)&len;
			iov[0].iov_len = sizeof(len);
			iov[1].iov_base = buf;
			iov[1].iov_len = buflen;
			if (writev(s, iov, 2) != sizeof(len) + buflen) {
				terrno = errno;
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					perror("write failed");
#endif DEBUG
				(void) close(s);
				s = -1;
				continue;
			}
			/*
			 * Receive length & response
			 */
			cp = answer;
			len = sizeof(short);
			while (len != 0 &&
			    (n = read(s, (char *)cp, (int)len)) > 0) {
				cp += n;
				len -= n;
			}
			if (n <= 0) {
				terrno = errno;
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					perror("read failed");
#endif DEBUG
				(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;
					ns--;
				}
				continue;
			}
			cp = answer;
			if ((resplen = ntohs(*(u_short *)cp)) > anslen) {
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					fprintf(stderr, "response truncated\n");
#endif DEBUG
				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;
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					perror("read failed");
#endif DEBUG
				(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;
#ifdef DEBUG
					if (_res.options & RES_DEBUG)
					    perror("socket (dg) failed");
#endif DEBUG
					continue;
				}
			}
#if SR
			/*
			 * Special case the send code below
			 * since we have just 1 server.
			 */
#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, &sin,
				    sizeof(struct sockaddr)) != buflen) {
					if (_res.options & RES_DEBUG)
						perror("sendto");
					continue;
				}
#endif
#else /* SR */
#if	BSD >= 43
			/*
			 * I'm tired of answering this question, so:
			 * 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 (_res.nscount == 1 || (try == 0 && ns == 0)) {
				/*
				 * Don't use connect if we might
				 * still receive a response
				 * from another server.
				 */
				if (connected == 0) {
					if (connect(s, &_res.nsaddr_list[ns],
					    sizeof(struct sockaddr)) < 0) {
#ifdef DEBUG
						if (_res.options & RES_DEBUG)
							perror("connect");
#endif DEBUG
						continue;
					}
					connected = 1;
				}
				if (send(s, buf, buflen, 0) != buflen) {
#ifdef DEBUG
					if (_res.options & RES_DEBUG)
						perror("send");
#endif DEBUG
					continue;
				}
			} else {
				/*
				 * Disconnect if we want to listen
				 * for responses from more than one server.
				 */
				if (connected) {
					(void) connect(s, &no_addr,
					    sizeof(no_addr));
					connected = 0;
				}
#endif BSD
				if (sendto(s, buf, buflen, 0,
				    &_res.nsaddr_list[ns],
				    sizeof(struct sockaddr)) != buflen) {
#ifdef DEBUG
					if (_res.options & RES_DEBUG)
						perror("sendto");
#endif DEBUG
					continue;
				}
#if	BSD >= 43
			}
#endif
#endif /* SR */

			/*
			 * Wait for reply
			 */
			timeout.tv_sec = (_res.retrans << try);
#if !SR
			if (try > 0)
				timeout.tv_sec /= _res.nscount;
#endif /* SR */
			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) {
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					perror("select");
#endif DEBUG
				continue;
			}
			if (n == 0) {
				/*
				 * timeout
				 */
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					printf("timeout (%d secs)\n", 
						timeout.tv_sec);
#endif DEBUG
#if BSD >= 43
				gotsomewhere = 1;
#endif
				continue;
			}
			if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					perror("recvfrom");
#endif DEBUG
				continue;
			}
			gotsomewhere = 1;
			if (id != anhp->id) {
				/*
				 * response from old query, ignore it
				 */
#if SR
				if (_res.options & RES_DEBUG2) {
					printf("------------\nOld answer:\n");
					Print_query(answer, answer+resplen, 1);
				}
#else
#ifdef DEBUG
				if (_res.options & RES_DEBUG) {
					printf("old answer:\n");
					p_query(answer);
				}
#endif DEBUG
#endif
				goto wait;
			}
			if (!(_res.options & RES_IGNTC) && anhp->tc) {
				/*
				 * get rest of answer;
				 * use TCP with same server.
				 */
#ifdef DEBUG
				if (_res.options & RES_DEBUG)
					printf("truncated answer\n");
#endif DEBUG
				(void) close(s);
				s = -1;
				v_circuit = 1;
				goto usevc;
			}
		}
#if SR
		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);
#else
#ifdef DEBUG
		if (_res.options & RES_DEBUG) {
			printf("got answer:\n");
			p_query(answer);
		}
#endif DEBUG
		/*
		 * 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 &&
		    ((_res.options & RES_USEVC) == 0 || ns != 0)) ||
		    (_res.options & RES_STAYOPEN) == 0) {
			(void) close(s);
			s = -1;
		}
		return (resplen);
	   }
#endif /* SR */
	}
	if (s >= 0) {
		(void) close(s);
		s = -1;
	}
#if SR
	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;
#else
	if (v_circuit == 0)
		if (gotsomewhere == 0)
			errno = ECONNREFUSED;	/* no nameservers found */
		else
			errno = ETIMEDOUT;	/* no answer obtained */
	else
		errno = terrno;
	return (-1);
#endif
}

/*
 * 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;
	}
}
Commit	Line	Data
b423e985	1	/*
e9e1a1f3	2	* Copyright (c) 1985, 1989 Regents of the University of California.
6b2f9dd0 KB	3	* All rights reserved.
6b2f9dd0 KB	4	*
af359dea C	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
1c15e888 C	32	*/
	33
	34	#ifndef lint
af359dea	35	static char sccsid[] = "@(#)send.c 5.18 (Berkeley) 3/2/91";
1c15e888 C	36	#endif /* not lint */
	37
	38	/*
	39	*******************************************************************************
	40	*
	41	* send.c --
	42	*
	43	* Routine to send request packets to a name server.
	44	*
	45	* Based on "@(#)res_send.c 6.25 (Berkeley) 6/1/90".
	46	*
	47	*******************************************************************************
b423e985 RC	48	*/
b423e985 RC	49
8ea4199d	50
616a94ba RC	51	/*
	52	* Send query to name server and wait for reply.
	53	*/
	54
04a773cb	55	#include <sys/param.h>
616a94ba RC	56	#include <sys/time.h>
616a94ba RC	57	#include <sys/socket.h>
679f3274	58	#include <sys/uio.h>
616a94ba RC	59	#include <netinet/in.h>
	60	#include <stdio.h>
	61	#include <errno.h>
27df2740	62	#include <arpa/nameser.h>
1c15e888	63	#include <arpa/inet.h>
f94b2f50	64	#include <resolv.h>
1c15e888	65	#include "res.h"
616a94ba RC	66
	67	extern int errno;
	68
3126f4c0	69	static int s = -1; /* socket used for communications */
1c15e888	70
15537e14 KD	71
	72	#ifndef FD_SET
	73	#define NFDBITS 32
	74	#define FD_SETSIZE 32
	75	#define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] \|= (1 << ((n) % NFDBITS)))
	76	#define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
	77	#define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
	78	#define FD_ZERO(p) bzero((char )(p), sizeof((p)))
	79	#endif
3126f4c0	80
1c15e888 C	81	#define SR 1 /* SendRequest style */
	82
	83	#ifndef DEBUG
	84	#define DEBUG
	85	#endif
	86
	87	unsigned short nsport = NAMESERVER_PORT;
	88
	89
	90	\f
	91	/*
	92	*******************************************************************************
	93	*
	94	* SendRequest --
	95	*
	96	* Sends a request packet to a name server whose address
	97	* is specified by the first argument and returns with
	98	* the answer packet.
	99	*
	100	* Results:
	101	* SUCCESS - the request was sent and an answer
	102	* was received.
	103	* TIME_OUT - the virtual circuit connection timed-out
	104	* or a reply to a datagram wasn't received.
	105	*
	106	*
	107	*******************************************************************************
	108	*/
	109
	110	int
	111	SendRequest(nsAddrPtr, buf, buflen, answer, anslen, trueLenPtr)
	112	struct in_addr *nsAddrPtr;
	113	char *buf;
	114	int buflen;
	115	char *answer;
	116	u_int anslen;
	117	int *trueLenPtr;
616a94ba RC	118	{
616a94ba RC	119	register int n;
e9e1a1f3	120	int try, v_circuit, resplen, ns;
2344735f	121	int gotsomewhere = 0, connected = 0;
17b5e053	122	int connreset = 0;
616a94ba RC	123	u_short id, len;
616a94ba RC	124	char *cp;
ac3ceb42	125	fd_set dsmask;
616a94ba RC	126	struct timeval timeout;
	127	HEADER hp = (HEADER ) buf;
	128	HEADER anhp = (HEADER ) answer;
679f3274	129	struct iovec iov[2];
1ea504e8	130	int terrno = ETIMEDOUT;
2344735f	131	char junk[512];
616a94ba	132
1c15e888 C	133	#if SR
	134	struct sockaddr_in sin;
	135
	136	if (_res.options & RES_DEBUG2) {
	137	printf("------------\nSendRequest(), len %d\n", buflen);
	138	Print_query(buf, buf+buflen, 1);
	139	}
	140	sin.sin_family = AF_INET;
	141	sin.sin_port = htons(nsport);
	142	sin.sin_addr = *nsAddrPtr;
	143	#else
ae94a224	144	#ifdef DEBUG
616a94ba	145	if (_res.options & RES_DEBUG) {
31f0ead0	146	printf("res_send()\n");
616a94ba RC	147	p_query(buf);
616a94ba RC	148	}
0b8992ca	149	#endif DEBUG
31f0ead0	150	if (!(_res.options & RES_INIT))
ae94a224 JB	151	if (res_init() == -1) {
	152	return(-1);
	153	}
1c15e888	154	#endif /* SR */
616a94ba RC	155	v_circuit = (_res.options & RES_USEVC) \|\| buflen > PACKETSZ;
	156	id = hp->id;
	157	/*
	158	* Send request, RETRY times, or until successful
	159	*/
e9e1a1f3	160	for (try = 0; try < _res.retry; try++) {
1c15e888	161	#if !SR
0b8992ca KD	162	for (ns = 0; ns < _res.nscount; ns++) {
	163	#ifdef DEBUG
	164	if (_res.options & RES_DEBUG)
	165	printf("Querying server (# %d) address = %s\n", ns+1,
2344735f	166	inet_ntoa(_res.nsaddr_list[ns].sin_addr));
0b8992ca	167	#endif DEBUG
1c15e888	168	#endif /* !SR */
e9e1a1f3	169	usevc:
616a94ba	170	if (v_circuit) {
2344735f MK	171	int truncated = 0;
2344735f MK	172
616a94ba	173	/*
e9e1a1f3 MK	174	* Use virtual circuit;
e9e1a1f3 MK	175	* at most one attempt per server.
616a94ba	176	*/
e9e1a1f3	177	try = _res.retry;
a5d4a4c0	178	if (s < 0) {
616a94ba	179	s = socket(AF_INET, SOCK_STREAM, 0);
92a82fe4	180	if (s < 0) {
1ea504e8	181	terrno = errno;
92a82fe4 MK	182	#ifdef DEBUG
92a82fe4 MK	183	if (_res.options & RES_DEBUG)
f7d00d5e	184	perror("socket (vc) failed");
92a82fe4 MK	185	#endif DEBUG
	186	continue;
	187	}
1c15e888	188	#if SR
af359dea	189	if (connect(s, (struct sockaddr *)&sin,
1c15e888	190	#else
af359dea C	191	if (connect(s,
af359dea C	192	(struct sockaddr *)&(_res.nsaddr_list[ns]),
1c15e888	193	#endif
a5d4a4c0	194	sizeof(struct sockaddr)) < 0) {
1ea504e8	195	terrno = errno;
ae94a224	196	#ifdef DEBUG
a5d4a4c0	197	if (_res.options & RES_DEBUG)
747d796e	198	perror("connect failed");
0b8992ca	199	#endif DEBUG
a5d4a4c0 JB	200	(void) close(s);
	201	s = -1;
	202	continue;
	203	}
616a94ba RC	204	}
	205	/*
	206	* Send length & message
	207	*/
3126f4c0	208	len = htons((u_short)buflen);
679f3274 JB	209	iov[0].iov_base = (caddr_t)&len;
	210	iov[0].iov_len = sizeof(len);
	211	iov[1].iov_base = buf;
	212	iov[1].iov_len = buflen;
	213	if (writev(s, iov, 2) != sizeof(len) + buflen) {
1ea504e8	214	terrno = errno;
ae94a224	215	#ifdef DEBUG
616a94ba	216	if (_res.options & RES_DEBUG)
747d796e	217	perror("write failed");
0b8992ca	218	#endif DEBUG
616a94ba RC	219	(void) close(s);
	220	s = -1;
	221	continue;
	222	}
	223	/*
	224	* Receive length & response
	225	*/
	226	cp = answer;
	227	len = sizeof(short);
679f3274	228	while (len != 0 &&
747d796e	229	(n = read(s, (char *)cp, (int)len)) > 0) {
616a94ba RC	230	cp += n;
	231	len -= n;
	232	}
	233	if (n <= 0) {
1ea504e8	234	terrno = errno;
ae94a224	235	#ifdef DEBUG
616a94ba	236	if (_res.options & RES_DEBUG)
747d796e	237	perror("read failed");
0b8992ca	238	#endif DEBUG
616a94ba RC	239	(void) close(s);
616a94ba RC	240	s = -1;
17b5e053 JB	241	/*
	242	* A long running process might get its TCP
	243	* connection reset if the remote server was
	244	* restarted. Requery the server instead of
	245	* trying a new one. When there is only one
	246	* server, this means that a query might work
	247	* instead of failing. We only allow one reset
	248	* per query to prevent looping.
	249	*/
	250	if (terrno == ECONNRESET && !connreset) {
	251	connreset = 1;
	252	ns--;
	253	}
616a94ba RC	254	continue;
	255	}
	256	cp = answer;
2344735f MK	257	if ((resplen = ntohs((u_short )cp)) > anslen) {
	258	#ifdef DEBUG
	259	if (_res.options & RES_DEBUG)
	260	fprintf(stderr, "response truncated\n");
	261	#endif DEBUG
	262	len = anslen;
	263	truncated = 1;
	264	} else
	265	len = resplen;
679f3274	266	while (len != 0 &&
747d796e	267	(n = read(s, (char *)cp, (int)len)) > 0) {
616a94ba RC	268	cp += n;
	269	len -= n;
	270	}
	271	if (n <= 0) {
1ea504e8	272	terrno = errno;
ae94a224	273	#ifdef DEBUG
616a94ba	274	if (_res.options & RES_DEBUG)
747d796e	275	perror("read failed");
0b8992ca	276	#endif DEBUG
616a94ba RC	277	(void) close(s);
	278	s = -1;
	279	continue;
	280	}
2344735f MK	281	if (truncated) {
	282	/*
	283	* Flush rest of answer
	284	* so connection stays in synch.
	285	*/
	286	anhp->tc = 1;
	287	len = resplen - anslen;
	288	while (len != 0) {
	289	n = (len > sizeof(junk) ?
	290	sizeof(junk) : len);
	291	if ((n = read(s, junk, n)) > 0)
	292	len -= n;
	293	else
	294	break;
	295	}
	296	}
616a94ba RC	297	} else {
	298	/*
	299	* Use datagrams.
	300	*/
f7d00d5e	301	if (s < 0) {
616a94ba	302	s = socket(AF_INET, SOCK_DGRAM, 0);
f7d00d5e JB	303	if (s < 0) {
	304	terrno = errno;
	305	#ifdef DEBUG
	306	if (_res.options & RES_DEBUG)
	307	perror("socket (dg) failed");
	308	#endif DEBUG
	309	continue;
	310	}
	311	}
1c15e888 C	312	#if SR
	313	/*
	314	* Special case the send code below
	315	* since we have just 1 server.
	316	*/
	317	#if BSD >= 43
	318	if (connected == 0) {
af359dea	319	if (connect(s, (struct sockaddr *)&sin,
1c15e888 C	320	sizeof(struct sockaddr)) < 0) {
	321	if (_res.options & RES_DEBUG)
	322	perror("connect");
	323	continue;
	324	}
	325	connected = 1;
	326	}
	327	if (send(s, buf, buflen, 0) != buflen) {
	328	if (_res.options & RES_DEBUG)
	329	perror("send");
	330	continue;
	331	}
	332	#else /* BSD */
	333	if (sendto(s, buf, buflen, 0, &sin,
	334	sizeof(struct sockaddr)) != buflen) {
	335	if (_res.options & RES_DEBUG)
	336	perror("sendto");
	337	continue;
	338	}
	339	#endif
	340	#else /* SR */
92a82fe4	341	#if BSD >= 43
e9e1a1f3 MK	342	/*
	343	* I'm tired of answering this question, so:
	344	* On a 4.3BSD+ machine (client and server,
	345	* actually), sending to a nameserver datagram
	346	* port with no nameserver will cause an
	347	* ICMP port unreachable message to be returned.
	348	* If our datagram socket is "connected" to the
	349	* server, we get an ECONNREFUSED error on the next
	350	* socket operation, and select returns if the
	351	* error message is received. We can thus detect
	352	* the absence of a nameserver without timing out.
	353	* If we have sent queries to at least two servers,
	354	* however, we don't want to remain connected,
	355	* as we wish to receive answers from the first
	356	* server to respond.
	357	*/
	358	if (_res.nscount == 1 \|\| (try == 0 && ns == 0)) {
7a8f7802	359	/*
9bb3997d MK	360	* Don't use connect if we might
	361	* still receive a response
	362	* from another server.
7a8f7802	363	*/
2344735f MK	364	if (connected == 0) {
	365	if (connect(s, &_res.nsaddr_list[ns],
	366	sizeof(struct sockaddr)) < 0) {
	367	#ifdef DEBUG
	368	if (_res.options & RES_DEBUG)
	369	perror("connect");
	370	#endif DEBUG
	371	continue;
	372	}
	373	connected = 1;
	374	}
	375	if (send(s, buf, buflen, 0) != buflen) {
ae94a224	376	#ifdef DEBUG
7a8f7802	377	if (_res.options & RES_DEBUG)
2344735f	378	perror("send");
0b8992ca	379	#endif DEBUG
7a8f7802 KD	380	continue;
7a8f7802 KD	381	}
fee59cfd MK	382	} else {
	383	/*
	384	* Disconnect if we want to listen
	385	* for responses from more than one server.
	386	*/
	387	if (connected) {
	388	(void) connect(s, &no_addr,
	389	sizeof(no_addr));
	390	connected = 0;
	391	}
7a8f7802	392	#endif BSD
fee59cfd MK	393	if (sendto(s, buf, buflen, 0,
	394	&_res.nsaddr_list[ns],
	395	sizeof(struct sockaddr)) != buflen) {
92a82fe4	396	#ifdef DEBUG
fee59cfd MK	397	if (_res.options & RES_DEBUG)
fee59cfd MK	398	perror("sendto");
92a82fe4	399	#endif DEBUG
fee59cfd MK	400	continue;
	401	}
	402	#if BSD >= 43
616a94ba	403	}
fee59cfd	404	#endif
1c15e888	405	#endif /* SR */
7a8f7802	406
616a94ba	407	/*
747d796e	408	* Wait for reply
616a94ba	409	*/
e9e1a1f3	410	timeout.tv_sec = (_res.retrans << try);
1c15e888	411	#if !SR
e9e1a1f3 MK	412	if (try > 0)
e9e1a1f3 MK	413	timeout.tv_sec /= _res.nscount;
1c15e888	414	#endif /* SR */
747d796e KD	415	if (timeout.tv_sec <= 0)
747d796e KD	416	timeout.tv_sec = 1;
616a94ba	417	timeout.tv_usec = 0;
87b12937	418	wait:
ac3ceb42 KD	419	FD_ZERO(&dsmask);
ac3ceb42 KD	420	FD_SET(s, &dsmask);
679f3274 JB	421	n = select(s+1, &dsmask, (fd_set *)NULL,
679f3274 JB	422	(fd_set *)NULL, &timeout);
616a94ba	423	if (n < 0) {
ae94a224	424	#ifdef DEBUG
616a94ba	425	if (_res.options & RES_DEBUG)
747d796e	426	perror("select");
0b8992ca	427	#endif DEBUG
616a94ba RC	428	continue;
	429	}
	430	if (n == 0) {
	431	/*
	432	* timeout
	433	*/
ae94a224	434	#ifdef DEBUG
616a94ba	435	if (_res.options & RES_DEBUG)
1c15e888 C	436	printf("timeout (%d secs)\n",
1c15e888 C	437	timeout.tv_sec);
0b8992ca	438	#endif DEBUG
e9e1a1f3	439	#if BSD >= 43
92a82fe4	440	gotsomewhere = 1;
e9e1a1f3	441	#endif
616a94ba RC	442	continue;
616a94ba RC	443	}
dd7a6a73	444	if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
ae94a224	445	#ifdef DEBUG
616a94ba	446	if (_res.options & RES_DEBUG)
747d796e	447	perror("recvfrom");
0b8992ca	448	#endif DEBUG
616a94ba RC	449	continue;
616a94ba RC	450	}
92a82fe4	451	gotsomewhere = 1;
616a94ba RC	452	if (id != anhp->id) {
	453	/*
	454	* response from old query, ignore it
	455	*/
1c15e888 C	456	#if SR
	457	if (_res.options & RES_DEBUG2) {
	458	printf("------------\nOld answer:\n");
	459	Print_query(answer, answer+resplen, 1);
	460	}
	461	#else
ae94a224	462	#ifdef DEBUG
616a94ba	463	if (_res.options & RES_DEBUG) {
616a94ba	464	printf("old answer:\n");
616a94ba RC	465	p_query(answer);
616a94ba RC	466	}
0b8992ca	467	#endif DEBUG
1c15e888	468	#endif
87b12937	469	goto wait;
616a94ba RC	470	}
	471	if (!(_res.options & RES_IGNTC) && anhp->tc) {
	472	/*
e9e1a1f3 MK	473	* get rest of answer;
e9e1a1f3 MK	474	* use TCP with same server.
616a94ba	475	*/
ae94a224	476	#ifdef DEBUG
616a94ba RC	477	if (_res.options & RES_DEBUG)
616a94ba RC	478	printf("truncated answer\n");
0b8992ca	479	#endif DEBUG
616a94ba RC	480	(void) close(s);
616a94ba RC	481	s = -1;
616a94ba	482	v_circuit = 1;
e9e1a1f3	483	goto usevc;
616a94ba RC	484	}
616a94ba RC	485	}
1c15e888 C	486	#if SR
	487	if (_res.options & RES_DEBUG) {
	488	if (_res.options & RES_DEBUG2)
	489	printf("------------\nGot answer (%d bytes):\n",
	490	resplen);
	491	else
	492	printf("------------\nGot answer:\n");
	493	Print_query(answer, answer+resplen, 1);
	494	}
	495	(void) close(s);
	496	s = -1;
	497	*trueLenPtr = resplen;
	498	return (SUCCESS);
	499	#else
ae94a224	500	#ifdef DEBUG
616a94ba RC	501	if (_res.options & RES_DEBUG) {
	502	printf("got answer:\n");
	503	p_query(answer);
	504	}
0b8992ca	505	#endif DEBUG
a5d4a4c0	506	/*
e9e1a1f3 MK	507	* If using virtual circuits, we assume that the first server
	508	* is preferred * over the rest (i.e. it is on the local
	509	* machine) and only keep that one open.
	510	* If we have temporarily opened a virtual circuit,
	511	* or if we haven't been asked to keep a socket open,
	512	* close the socket.
a5d4a4c0	513	*/
e9e1a1f3 MK	514	if ((v_circuit &&
	515	((_res.options & RES_USEVC) == 0 \|\| ns != 0)) \|\|
	516	(_res.options & RES_STAYOPEN) == 0) {
a5d4a4c0 JB	517	(void) close(s);
a5d4a4c0 JB	518	s = -1;
a5d4a4c0	519	}
fee59cfd	520	return (resplen);
0b8992ca	521	}
1c15e888	522	#endif /* SR */
616a94ba	523	}
1ea504e8 JB	524	if (s >= 0) {
	525	(void) close(s);
	526	s = -1;
	527	}
1c15e888 C	528	#if SR
	529	if (v_circuit == 0)
	530	if (gotsomewhere == 0)
	531	return NO_RESPONSE; /* no nameservers found */
	532	else
	533	return TIME_OUT; /* no answer obtained */
	534	else
	535	if (errno == ECONNREFUSED)
	536	return NO_RESPONSE;
	537	else
	538	return ERROR;
	539	#else
1ea504e8 JB	540	if (v_circuit == 0)
1ea504e8 JB	541	if (gotsomewhere == 0)
e9e1a1f3	542	errno = ECONNREFUSED; /* no nameservers found */
1ea504e8	543	else
e9e1a1f3	544	errno = ETIMEDOUT; /* no answer obtained */
92a82fe4	545	else
1ea504e8	546	errno = terrno;
616a94ba	547	return (-1);
1c15e888	548	#endif
616a94ba	549	}
3126f4c0 JB	550
	551	/*
	552	* This routine is for closing the socket if a virtual circuit is used and
1c15e888	553	* the program wants to close it.
3126f4c0	554	*
1c15e888	555	* Called from the interrupt handler.
3126f4c0	556	*/
1c15e888	557	SendRequest_close()
3126f4c0 JB	558	{
	559	if (s != -1) {
	560	(void) close(s);
	561	s = -1;
	562	}
	563	}