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talkd.c revision 1.6 
      1 /*	$NetBSD: talkd.c,v 1.6 1997/06/29 19:13:05 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) 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
     43 #if 0
     44 static char sccsid[] = "@(#)talkd.c	8.1 (Berkeley) 6/4/93";
     45 #else
     46 __RCSID("$NetBSD: talkd.c,v 1.6 1997/06/29 19:13:05 christos Exp $");
     47 #endif
     48 #endif /* not lint */
     49 
     50 /*
     51  * The top level of the daemon, the format is heavily borrowed
     52  * from rwhod.c. Basically: find out who and where you are;
     53  * disconnect all descriptors and ttys, and then endless
     54  * loop on waiting for and processing requests
     55  */
     56 #include <sys/types.h>
     57 #include <sys/socket.h>
     58 #include <sys/param.h>
     59 
     60 #include <protocols/talkd.h>
     61 #include <signal.h>
     62 #include <syslog.h>
     63 #include <time.h>
     64 #include <errno.h>
     65 #include <unistd.h>
     66 #include <stdio.h>
     67 #include <stdlib.h>
     68 #include <string.h>
     69 #include <paths.h>
     70 #include "extern.h"
     71 
     72 CTL_MSG		request;
     73 CTL_RESPONSE	response;
     74 
     75 int	sockt = STDIN_FILENO;
     76 int	debug = 0;
     77 long	lastmsgtime;
     78 
     79 char	hostname[MAXHOSTNAMELEN + 1];
     80 
     81 #define TIMEOUT 30
     82 #define MAXIDLE 120
     83 
     84 static void timeout __P((int));
     85 int	main __P((int, char *[]));
     86 
     87 int
     88 main(argc, argv)
     89 	int argc;
     90 	char *argv[];
     91 {
     92 	CTL_MSG *mp = &request;
     93 	int cc;
     94 
     95 	if (getuid()) {
     96 		fprintf(stderr, "%s: getuid: not super-user\n", argv[0]);
     97 		exit(1);
     98 	}
     99 	openlog("talkd", LOG_PID, LOG_DAEMON);
    100 	if (gethostname(hostname, sizeof (hostname) - 1) < 0) {
    101 		syslog(LOG_ERR, "gethostname: %m");
    102 		_exit(1);
    103 	}
    104 	hostname[MAXHOSTNAMELEN] = '\0';  /* ensure null termination */
    105 	if (chdir(_PATH_DEV) < 0) {
    106 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
    107 		_exit(1);
    108 	}
    109 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
    110 		debug = 1;
    111 	signal(SIGALRM, timeout);
    112 	alarm(TIMEOUT);
    113 	for (;;) {
    114 		extern int errno;
    115 
    116 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
    117 		if (cc != sizeof (*mp)) {
    118 			if (cc < 0 && errno != EINTR)
    119 				syslog(LOG_WARNING, "recv: %m");
    120 			continue;
    121 		}
    122 		lastmsgtime = time(0);
    123 		process_request(mp, &response);
    124 		/* can block here, is this what I want? */
    125 		cc = sendto(sockt, (char *)&response,
    126 		    sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
    127 		    sizeof (mp->ctl_addr));
    128 		if (cc != sizeof (response))
    129 			syslog(LOG_WARNING, "sendto: %m");
    130 	}
    131 }
    132 
    133 void
    134 timeout(n)
    135 	int n;
    136 {
    137 
    138 	if (time(0) - lastmsgtime >= MAXIDLE)
    139 		_exit(0);
    140 	alarm(TIMEOUT);
    141 }
    142