ctl_transact.c revision eb1a5f8de9f7ea602c373a710f531abbf81141c4
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
42#include "talk.h"
43#include "talk_ctl.h"
44
45#define CTL_WAIT 2	/* time to wait for a response, in seconds */
46
47/*
48 * SOCKDGRAM is unreliable, so we must repeat messages if we have
49 * not received an acknowledgement within a reasonable amount
50 * of time
51 */
52void
53ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
54{
55	fd_set read_mask, ctl_mask;
56	int nready = 0, cc;
57	struct timeval wait;
58
59	lmsg.type = type;
60	daemon_addr.sin_addr = target;
61	daemon_addr.sin_port = daemon_port;
62	FD_ZERO(&ctl_mask);
63	FD_SET(ctl_sockt, &ctl_mask);
64
65	/*
66	 * Keep sending the message until a response of
67	 * the proper type is obtained.
68	 */
69	do {
70		wait.tv_sec = CTL_WAIT;
71		wait.tv_usec = 0;
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			read_mask = ctl_mask;
83			nready = select(32, &read_mask, 0, 0, &wait);
84			if (nready < 0) {
85				if (errno == EINTR)
86					continue;
87				p_error("Error waiting for daemon response");
88			}
89		} while (nready == 0);
90		/*
91		 * Keep reading while there are queued messages
92		 * (this is not necessary, it just saves extra
93		 * request/acknowledgements being sent)
94		 */
95		do {
96			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
97			if (cc < 0) {
98				if (errno == EINTR)
99					continue;
100				p_error("Error on read from talk daemon");
101			}
102			read_mask = ctl_mask;
103			/* an immediate poll */
104			timerclear(&wait);
105			nready = select(32, &read_mask, 0, 0, &wait);
106		} while (nready > 0 && (rp->vers != TALK_VERSION ||
107		    rp->type != type));
108	} while (rp->vers != TALK_VERSION || rp->type != type);
109	rp->id_num = ntohl(rp->id_num);
110	rp->addr.sa_family = ntohs(rp->addr.sa_family);
111}
112