xref: /freebsd/libexec/talkd/talkd.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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 static const char copyright[] =
36 "@(#) Copyright (c) 1983, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)talkd.c	8.1 (Berkeley) 6/4/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 /*
49  * The top level of the daemon, the format is heavily borrowed
50  * from rwhod.c. Basically: find out who and where you are;
51  * disconnect all descriptors and ttys, and then endless
52  * loop on waiting for and processing requests
53  */
54 #include <sys/types.h>
55 #include <sys/socket.h>
56 #include <sys/param.h>
57 #include <netinet/in.h>
58 #include <protocols/talkd.h>
59 #include <err.h>
60 #include <errno.h>
61 #include <paths.h>
62 #include <signal.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <syslog.h>
67 #include <time.h>
68 #include <unistd.h>
69 
70 #include "extern.h"
71 
72 CTL_MSG		request;
73 CTL_RESPONSE	response;
74 
75 int	debug = 0;
76 long	lastmsgtime;
77 
78 char	hostname[MAXHOSTNAMELEN];
79 
80 #define TIMEOUT 30
81 #define MAXIDLE 120
82 
83 int
84 main(int argc, char *argv[])
85 {
86 	register CTL_MSG *mp = &request;
87 	int cc;
88 	struct sockaddr ctl_addr;
89 
90 #ifdef NOTDEF
91 	/*
92 	 * removed so ntalkd can run in tty sandbox
93 	 */
94 	if (getuid())
95 		errx(1, "getuid: not super-user");
96 #endif
97 	openlog("talkd", LOG_PID, LOG_DAEMON);
98 	if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
99 		syslog(LOG_ERR, "gethostname: %m");
100 		_exit(1);
101 	}
102 	hostname[sizeof(hostname) - 1] = '\0';
103 	if (chdir(_PATH_DEV) < 0) {
104 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
105 		_exit(1);
106 	}
107 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
108 		debug = 1;
109 	signal(SIGALRM, timeout);
110 	alarm(TIMEOUT);
111 	for (;;) {
112 		cc = recv(0, (char *)mp, sizeof(*mp), 0);
113 		if (cc != sizeof (*mp)) {
114 			if (cc < 0 && errno != EINTR)
115 				syslog(LOG_WARNING, "recv: %m");
116 			continue;
117 		}
118 		lastmsgtime = time(0);
119 		(void)memcpy(&ctl_addr, &mp->ctl_addr, sizeof(ctl_addr));
120 		ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
121 		ctl_addr.sa_len = sizeof(ctl_addr);
122 		process_request(mp, &response);
123 		/* can block here, is this what I want? */
124 		cc = sendto(STDIN_FILENO, (char *)&response,
125 		    sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
126 		if (cc != sizeof (response))
127 			syslog(LOG_WARNING, "sendto: %m");
128 	}
129 }
130 
131 void
132 timeout(int sig __unused)
133 {
134 	int save_errno = errno;
135 
136 	if (time(0) - lastmsgtime >= MAXIDLE)
137 		_exit(0);
138 	alarm(TIMEOUT);
139 	errno = save_errno;
140 }
141