ctl_transact.c revision 3b842d34e82312a8004a7ecd65ccdb837ef72ac1
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
37#endif
38static const char rcsid[] =
39  "$FreeBSD$";
40#endif /* not lint */
41
42#include <errno.h>
43#include <string.h>
44#include "talk.h"
45#include "talk_ctl.h"
46
47#define CTL_WAIT 2	/* time to wait for a response, in seconds */
48
49/*
50 * SOCKDGRAM is unreliable, so we must repeat messages if we have
51 * not recieved an acknowledgement within a reasonable amount
52 * of time
53 */
54void
55ctl_transact(target, msg, type, rp)
56	struct in_addr target;
57	CTL_MSG msg;
58	int type;
59	CTL_RESPONSE *rp;
60{
61	fd_set read_mask, ctl_mask;
62	int nready = 0, cc;
63	struct timeval wait;
64
65	msg.type = type;
66	daemon_addr.sin_addr = target;
67	daemon_addr.sin_port = daemon_port;
68	FD_ZERO(&ctl_mask);
69	FD_SET(ctl_sockt, &ctl_mask);
70
71	/*
72	 * Keep sending the message until a response of
73	 * the proper type is obtained.
74	 */
75	do {
76		wait.tv_sec = CTL_WAIT;
77		wait.tv_usec = 0;
78		/* resend message until a response is obtained */
79		do {
80			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
81			    (struct sockaddr *)&daemon_addr,
82			    sizeof (daemon_addr));
83			if (cc != sizeof (msg)) {
84				if (errno == EINTR)
85					continue;
86				p_error("Error on write to talk daemon");
87			}
88			read_mask = ctl_mask;
89			nready = select(32, &read_mask, 0, 0, &wait);
90			if (nready < 0) {
91				if (errno == EINTR)
92					continue;
93				p_error("Error waiting for daemon response");
94			}
95		} while (nready == 0);
96		/*
97		 * Keep reading while there are queued messages
98		 * (this is not necessary, it just saves extra
99		 * request/acknowledgements being sent)
100		 */
101		do {
102			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
103			if (cc < 0) {
104				if (errno == EINTR)
105					continue;
106				p_error("Error on read from talk daemon");
107			}
108			read_mask = ctl_mask;
109			/* an immediate poll */
110			timerclear(&wait);
111			nready = select(32, &read_mask, 0, 0, &wait);
112		} while (nready > 0 && (rp->vers != TALK_VERSION ||
113		    rp->type != type));
114	} while (rp->vers != TALK_VERSION || rp->type != type);
115	rp->id_num = ntohl(rp->id_num);
116	rp->addr.sa_family = ntohs(rp->addr.sa_family);
117}
118