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talkd.c revision 1.1 
      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[] = "@(#)talkd.c	5.8 (Berkeley) 2/26/91";
     42 #endif /* not lint */
     43 
     44 /*
     45  * The top level of the daemon, the format is heavily borrowed
     46  * from rwhod.c. Basically: find out who and where you are;
     47  * disconnect all descriptors and ttys, and then endless
     48  * loop on waiting for and processing requests
     49  */
     50 #include <sys/types.h>
     51 #include <sys/socket.h>
     52 #include <protocols/talkd.h>
     53 #include <signal.h>
     54 #include <syslog.h>
     55 #include <time.h>
     56 #include <errno.h>
     57 #include <unistd.h>
     58 #include <stdio.h>
     59 #include <stdlib.h>
     60 #include <string.h>
     61 #include <paths.h>
     62 
     63 CTL_MSG		request;
     64 CTL_RESPONSE	response;
     65 
     66 int	sockt;
     67 int	debug = 0;
     68 void	timeout();
     69 long	lastmsgtime;
     70 
     71 char	hostname[32];
     72 
     73 #define TIMEOUT 30
     74 #define MAXIDLE 120
     75 
     76 main(argc, argv)
     77 	int argc;
     78 	char *argv[];
     79 {
     80 	register CTL_MSG *mp = &request;
     81 	int cc;
     82 
     83 	if (getuid()) {
     84 		fprintf(stderr, "%s: getuid: not super-user", argv[0]);
     85 		exit(1);
     86 	}
     87 	openlog("talkd", LOG_PID, LOG_DAEMON);
     88 	if (gethostname(hostname, sizeof (hostname) - 1) < 0) {
     89 		syslog(LOG_ERR, "gethostname: %m");
     90 		_exit(1);
     91 	}
     92 	if (chdir(_PATH_DEV) < 0) {
     93 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
     94 		_exit(1);
     95 	}
     96 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
     97 		debug = 1;
     98 	signal(SIGALRM, timeout);
     99 	alarm(TIMEOUT);
    100 	for (;;) {
    101 		extern int errno;
    102 
    103 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
    104 		if (cc != sizeof (*mp)) {
    105 			if (cc < 0 && errno != EINTR)
    106 				syslog(LOG_WARNING, "recv: %m");
    107 			continue;
    108 		}
    109 		lastmsgtime = time(0);
    110 		process_request(mp, &response);
    111 		/* can block here, is this what I want? */
    112 		cc = sendto(sockt, (char *)&response,
    113 		    sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
    114 		    sizeof (mp->ctl_addr));
    115 		if (cc != sizeof (response))
    116 			syslog(LOG_WARNING, "sendto: %m");
    117 	}
    118 }
    119 
    120 void
    121 timeout()
    122 {
    123 
    124 	if (time(0) - lastmsgtime >= MAXIDLE)
    125 		_exit(0);
    126 	alarm(TIMEOUT);
    127 }
    128