ctl_transact.c revision a12cf8aa0e1029b87db1d40e09450d0d09635334
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
35static char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
36#endif /* not lint */
37
38#include <errno.h>
39#include <string.h>
40#include "talk.h"
41#include "talk_ctl.h"
42
43#define CTL_WAIT 2	/* time to wait for a response, in seconds */
44
45/*
46 * SOCKDGRAM is unreliable, so we must repeat messages if we have
47 * not recieved an acknowledgement within a reasonable amount
48 * of time
49 */
50void
51ctl_transact(target, msg, type, rp)
52	struct in_addr target;
53	CTL_MSG msg;
54	int type;
55	CTL_RESPONSE *rp;
56{
57	fd_set read_mask, ctl_mask;
58	int nready = 0, cc;
59	struct timeval wait;
60
61	msg.type = type;
62	daemon_addr.sin_addr = target;
63	daemon_addr.sin_port = daemon_port;
64	FD_ZERO(&ctl_mask);
65	FD_SET(ctl_sockt, &ctl_mask);
66
67	/*
68	 * Keep sending the message until a response of
69	 * the proper type is obtained.
70	 */
71	do {
72		wait.tv_sec = CTL_WAIT;
73		wait.tv_usec = 0;
74		/* resend message until a response is obtained */
75		do {
76			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
77			    (struct sockaddr *)&daemon_addr,
78			    sizeof (daemon_addr));
79			if (cc != sizeof (msg)) {
80				if (errno == EINTR)
81					continue;
82				p_error("Error on write to talk daemon");
83			}
84			read_mask = ctl_mask;
85			nready = select(32, &read_mask, 0, 0, &wait);
86			if (nready < 0) {
87				if (errno == EINTR)
88					continue;
89				p_error("Error waiting for daemon response");
90			}
91		} while (nready == 0);
92		/*
93		 * Keep reading while there are queued messages
94		 * (this is not necessary, it just saves extra
95		 * request/acknowledgements being sent)
96		 */
97		do {
98			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
99			if (cc < 0) {
100				if (errno == EINTR)
101					continue;
102				p_error("Error on read from talk daemon");
103			}
104			read_mask = ctl_mask;
105			/* an immediate poll */
106			timerclear(&wait);
107			nready = select(32, &read_mask, 0, 0, &wait);
108		} while (nready > 0 && (rp->vers != TALK_VERSION ||
109		    rp->type != type));
110	} while (rp->vers != TALK_VERSION || rp->type != type);
111	rp->id_num = ntohl(rp->id_num);
112	rp->addr.sa_family = ntohs(rp->addr.sa_family);
113}
114