talkd.c revision 22989 
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 *	$Id$
34 */
35
36#ifndef lint
37static char copyright[] =
38"@(#) Copyright (c) 1983, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n";
40#endif /* not lint */
41
42#ifndef lint
43static char sccsid[] = "@(#)talkd.c	8.1 (Berkeley) 6/4/93";
44#endif /* not lint */
45
46/*
47 * The top level of the daemon, the format is heavily borrowed
48 * from rwhod.c. Basically: find out who and where you are;
49 * disconnect all descriptors and ttys, and then endless
50 * loop on waiting for and processing requests
51 */
52#include <sys/types.h>
53#include <sys/socket.h>
54#include <sys/param.h>
55#include <protocols/talkd.h>
56#include <signal.h>
57#include <syslog.h>
58#include <time.h>
59#include <errno.h>
60#include <unistd.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <paths.h>
65
66CTL_MSG		request;
67CTL_RESPONSE	response;
68
69int	sockt;
70int	debug = 0;
71void	timeout();
72long	lastmsgtime;
73
74char    hostname[MAXHOSTNAMELEN + 1];
75
76#define TIMEOUT 30
77#define MAXIDLE 120
78
79main(argc, argv)
80	int argc;
81	char *argv[];
82{
83	register CTL_MSG *mp = &request;
84	int cc;
85
86	if (getuid()) {
87		fprintf(stderr, "%s: getuid: not super-user\n", argv[0]);
88		exit(1);
89	}
90	openlog("talkd", LOG_PID, LOG_DAEMON);
91	if (gethostname(hostname, sizeof (hostname) - 1) < 0) {
92		syslog(LOG_ERR, "gethostname: %m");
93		_exit(1);
94	}
95	if (chdir(_PATH_DEV) < 0) {
96		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
97		_exit(1);
98	}
99	if (argc > 1 && strcmp(argv[1], "-d") == 0)
100		debug = 1;
101	signal(SIGALRM, timeout);
102	alarm(TIMEOUT);
103	for (;;) {
104		extern int errno;
105
106		cc = recv(0, (char *)mp, sizeof (*mp), 0);
107		if (cc != sizeof (*mp)) {
108			if (cc < 0 && errno != EINTR)
109				syslog(LOG_WARNING, "recv: %m");
110			continue;
111		}
112		lastmsgtime = time(0);
113		process_request(mp, &response);
114		/* can block here, is this what I want? */
115		mp->ctl_addr.sa_family = htons(mp->ctl_addr.sa_family);
116		cc = sendto(sockt, (char *)&response,
117		    sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
118		    sizeof (mp->ctl_addr));
119		if (cc != sizeof (response))
120			syslog(LOG_WARNING, "sendto: %m");
121	}
122}
123
124void
125timeout()
126{
127
128	if (time(0) - lastmsgtime >= MAXIDLE)
129		_exit(0);
130	alarm(TIMEOUT);
131}
132