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#include <sys/cdefs.h>
33
34__FBSDID("$FreeBSD$");
35
36#ifndef lint
37static const char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
38#endif
39
40#include <arpa/inet.h>
41
42#include <errno.h>
43#include <poll.h>
44
45#include "talk.h"
46#include "talk_ctl.h"
47
48#define CTL_WAIT 2	/* time to wait for a response, in seconds */
49
50/*
51 * SOCKDGRAM is unreliable, so we must repeat messages if we have
52 * not received an acknowledgement within a reasonable amount
53 * of time
54 */
55void
56ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
57{
58	struct pollfd pfd[1];
59	int nready = 0, cc;
60
61	lmsg.type = type;
62	daemon_addr.sin_addr = target;
63	daemon_addr.sin_port = daemon_port;
64	pfd[0].fd = ctl_sockt;
65	pfd[0].events = POLLIN;
66
67	/*
68	 * Keep sending the message until a response of
69	 * the proper type is obtained.
70	 */
71	do {
72		/* resend message until a response is obtained */
73		do {
74			cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
75			    (struct sockaddr *)&daemon_addr,
76			    sizeof (daemon_addr));
77			if (cc != sizeof (lmsg)) {
78				if (errno == EINTR)
79					continue;
80				p_error("Error on write to talk daemon");
81			}
82			nready = poll(pfd, 1, CTL_WAIT * 1000);
83			if (nready < 0) {
84				if (errno == EINTR)
85					continue;
86				p_error("Error waiting for daemon response");
87			}
88		} while (nready == 0);
89		/*
90		 * Keep reading while there are queued messages
91		 * (this is not necessary, it just saves extra
92		 * request/acknowledgements being sent)
93		 */
94		do {
95			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
96			if (cc < 0) {
97				if (errno == EINTR)
98					continue;
99				p_error("Error on read from talk daemon");
100			}
101			nready = poll(pfd, 1, 0);
102		} while (nready > 0 && (rp->vers != TALK_VERSION ||
103		    rp->type != type));
104	} while (rp->vers != TALK_VERSION || rp->type != type);
105	rp->id_num = ntohl(rp->id_num);
106	rp->addr.sa_family = ntohs(rp->addr.sa_family);
107}
108