1/*	$OpenBSD: ctl_transact.c,v 1.13 2016/02/01 07:29:25 mestre Exp $	*/
2/*	$NetBSD: ctl_transact.c,v 1.3 1994/12/09 02:14:12 jtc Exp $	*/
3
4/*
5 * Copyright (c) 1983, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/socket.h>
34#include <netinet/in.h>
35
36#include <errno.h>
37#include <poll.h>
38
39#include "talk.h"
40#include "talk_ctl.h"
41
42#define CTL_WAIT 2	/* time to wait for a response, in seconds */
43
44/*
45 * SOCKDGRAM is unreliable, so we must repeat messages if we have
46 * not received an acknowledgement within a reasonable amount
47 * of time
48 */
49void
50ctl_transact(struct in_addr target, CTL_MSG msg, int type, CTL_RESPONSE *rp)
51{
52	struct pollfd pfd[1];
53	int nready, cc;
54
55	msg.type = type;
56	daemon_addr.sin_addr = target;
57	daemon_addr.sin_port = daemon_port;
58	pfd[0].fd = ctl_sockt;
59	pfd[0].events = POLLIN;
60
61	/*
62	 * Keep sending the message until a response of
63	 * the proper type is obtained.
64	 */
65	do {
66		/* resend message until a response is obtained */
67		do {
68			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
69			    (struct sockaddr *)&daemon_addr,
70			    sizeof (daemon_addr));
71			if (cc != sizeof (msg)) {
72				if (errno == EINTR)
73					continue;
74				quit("Error on write to talk daemon", 1);
75			}
76			nready = poll(pfd, 1, CTL_WAIT * 1000);
77			if (nready < 0) {
78				if (errno == EINTR)
79					continue;
80				quit("Error waiting for daemon response", 1);
81			}
82		} while (nready == 0);
83		/*
84		 * Keep reading while there are queued messages
85		 * (this is not necessary, it just saves extra
86		 * request/acknowledgements being sent)
87		 */
88		do {
89			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
90			if (cc < 0) {
91				if (errno == EINTR)
92					continue;
93				quit("Error on read from talk daemon", 1);
94			}
95			nready = poll(pfd, 1, 0);
96		} while (nready > 0 && (rp->vers != TALK_VERSION ||
97		    rp->type != type));
98	} while (rp->vers != TALK_VERSION || rp->type != type);
99	rp->id_num = ntohl(rp->id_num);
100}
101