ctl_transact.c revision 0c969eabba6f61fca563b0f670aad1cb5f8ab921
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31
32__FBSDID("$FreeBSD$");
33
34#ifndef lint
35static const char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
36#endif
37
38#include <arpa/inet.h>
39
40#include <errno.h>
41#include <poll.h>
42
43#include "talk.h"
44#include "talk_ctl.h"
45
46#define CTL_WAIT 2	/* time to wait for a response, in seconds */
47
48/*
49 * SOCKDGRAM is unreliable, so we must repeat messages if we have
50 * not received an acknowledgement within a reasonable amount
51 * of time
52 */
53void
54ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
55{
56	struct pollfd pfd[1];
57	int nready = 0, cc;
58
59	lmsg.type = type;
60	daemon_addr.sin_addr = target;
61	daemon_addr.sin_port = daemon_port;
62	pfd[0].fd = ctl_sockt;
63	pfd[0].events = POLLIN;
64
65	/*
66	 * Keep sending the message until a response of
67	 * the proper type is obtained.
68	 */
69	do {
70		/* resend message until a response is obtained */
71		do {
72			cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
73			    (struct sockaddr *)&daemon_addr,
74			    sizeof (daemon_addr));
75			if (cc != sizeof (lmsg)) {
76				if (errno == EINTR)
77					continue;
78				p_error("Error on write to talk daemon");
79			}
80			nready = poll(pfd, 1, CTL_WAIT * 1000);
81			if (nready < 0) {
82				if (errno == EINTR)
83					continue;
84				p_error("Error waiting for daemon response");
85			}
86		} while (nready == 0);
87		/*
88		 * Keep reading while there are queued messages
89		 * (this is not necessary, it just saves extra
90		 * request/acknowledgements being sent)
91		 */
92		do {
93			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
94			if (cc < 0) {
95				if (errno == EINTR)
96					continue;
97				p_error("Error on read from talk daemon");
98			}
99			nready = poll(pfd, 1, 0);
100		} while (nready > 0 && (rp->vers != TALK_VERSION ||
101		    rp->type != type));
102	} while (rp->vers != TALK_VERSION || rp->type != type);
103	rp->id_num = ntohl(rp->id_num);
104	rp->addr.sa_family = ntohs(rp->addr.sa_family);
105}
106