1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32
33
34#include <arpa/inet.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 lmsg, int type, CTL_RESPONSE *rp)
51{
52	struct pollfd pfd[1];
53	int nready = 0, cc;
54
55	lmsg.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 *)&lmsg, sizeof (lmsg), 0,
69			    (struct sockaddr *)&daemon_addr,
70			    sizeof (daemon_addr));
71			if (cc != sizeof (lmsg)) {
72				if (errno == EINTR)
73					continue;
74				p_error("Error on write to talk daemon");
75			}
76			nready = poll(pfd, 1, CTL_WAIT * 1000);
77			if (nready < 0) {
78				if (errno == EINTR)
79					continue;
80				p_error("Error waiting for daemon response");
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				p_error("Error on read from talk daemon");
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	rp->addr.sa_family = ntohs(rp->addr.sa_family);
101}
102