xref: /dragonfly/libexec/talkd/talkd.c (revision 9348a738)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
30  * @(#)talkd.c	8.1 (Berkeley) 6/4/93
31  * $FreeBSD: src/libexec/talkd/talkd.c,v 1.11.2.1 2001/10/18 12:30:42 des Exp $
32  */
33 
34 /*
35  * The top level of the daemon, the format is heavily borrowed
36  * from rwhod.c. Basically: find out who and where you are;
37  * disconnect all descriptors and ttys, and then endless
38  * loop on waiting for and processing requests
39  */
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <sys/param.h>
43 #include <protocols/talkd.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <paths.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <syslog.h>
52 #include <time.h>
53 #include <unistd.h>
54 
55 #include "extern.h"
56 
57 CTL_MSG		request;
58 CTL_RESPONSE	response;
59 
60 int	sockt;
61 int	debug = 0;
62 long	lastmsgtime;
63 
64 char	hostname[MAXHOSTNAMELEN];
65 
66 #define TIMEOUT 30
67 #define MAXIDLE 120
68 
69 int
70 main(int argc, char *argv[])
71 {
72 	CTL_MSG *mp = &request;
73 	int cc;
74 
75 #ifdef NOTDEF
76 	/*
77 	 * removed so ntalkd can run in tty sandbox
78 	 */
79 	if (getuid())
80 		errx(1, "getuid: not super-user");
81 #endif
82 	openlog("talkd", LOG_PID, LOG_DAEMON);
83 	if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
84 		syslog(LOG_ERR, "gethostname: %m");
85 		_exit(1);
86 	}
87 	hostname[sizeof(hostname) - 1] = '\0';
88 	if (chdir(_PATH_DEV) < 0) {
89 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
90 		_exit(1);
91 	}
92 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
93 		debug = 1;
94 	signal(SIGALRM, timeout);
95 	alarm(TIMEOUT);
96 	for (;;) {
97 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
98 		if (cc != sizeof (*mp)) {
99 			if (cc < 0 && errno != EINTR)
100 				syslog(LOG_WARNING, "recv: %m");
101 			continue;
102 		}
103 		lastmsgtime = time(0);
104 		process_request(mp, &response);
105 		/* can block here, is this what I want? */
106 		mp->ctl_addr.sa_family = htons(mp->ctl_addr.sa_family);
107 		cc = sendto(sockt, (char *)&response,
108 		    sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
109 		    sizeof (mp->ctl_addr));
110 		if (cc != sizeof (response))
111 			syslog(LOG_WARNING, "sendto: %m");
112 	}
113 }
114 
115 void
116 timeout(int sig __unused)
117 {
118 	int save_errno = errno;
119 
120 	if (time(0) - lastmsgtime >= MAXIDLE)
121 		_exit(0);
122 	alarm(TIMEOUT);
123 	errno = save_errno;
124 }
125