xref: /netbsd-src/libexec/talkd/talkd.c (revision d0fed6c87ddc40a8bffa6f99e7433ddfc864dd83)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * 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 char copyright[] =
36 "@(#) Copyright (c) 1983 Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)talkd.c	5.8 (Berkeley) 2/26/91";*/
42 static char rcsid[] = "$Id: talkd.c,v 1.4 1997/01/29 10:30:14 explorer Exp $";
43 #endif /* not lint */
44 
45 /*
46  * The top level of the daemon, the format is heavily borrowed
47  * from rwhod.c. Basically: find out who and where you are;
48  * disconnect all descriptors and ttys, and then endless
49  * loop on waiting for and processing requests
50  */
51 #include <sys/types.h>
52 #include <sys/socket.h>
53 #include <sys/param.h>
54 
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 
66 CTL_MSG		request;
67 CTL_RESPONSE	response;
68 
69 int	sockt;
70 int	debug = 0;
71 void	timeout();
72 long	lastmsgtime;
73 
74 char	hostname[MAXHOSTNAMELEN + 1];
75 
76 #define TIMEOUT 30
77 #define MAXIDLE 120
78 
79 main(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", 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 	hostname[MAXHOSTNAMELEN] = 0;  /* ensure null termination */
96 	if (chdir(_PATH_DEV) < 0) {
97 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
98 		_exit(1);
99 	}
100 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
101 		debug = 1;
102 	signal(SIGALRM, timeout);
103 	alarm(TIMEOUT);
104 	for (;;) {
105 		extern int errno;
106 
107 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
108 		if (cc != sizeof (*mp)) {
109 			if (cc < 0 && errno != EINTR)
110 				syslog(LOG_WARNING, "recv: %m");
111 			continue;
112 		}
113 		lastmsgtime = time(0);
114 		process_request(mp, &response);
115 		/* can block here, is this what I want? */
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 
124 void
125 timeout()
126 {
127 
128 	if (time(0) - lastmsgtime >= MAXIDLE)
129 		_exit(0);
130 	alarm(TIMEOUT);
131 }
132