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      1 /*	$NetBSD: talkd.c,v 1.21 2009/03/16 01:04:32 lukem 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
     35  The Regents of the University of California.  All rights reserved.");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)talkd.c	8.1 (Berkeley) 6/4/93";
     41 #else
     42 __RCSID("$NetBSD: talkd.c,v 1.21 2009/03/16 01:04:32 lukem Exp $");
     43 #endif
     44 #endif /* not lint */
     45 
     46 /*
     47  * The top level of the daemon, the format is heavily borrowed
     48  * from rwhod.c. Basically: find out who and where you are;
     49  * disconnect all descriptors and ttys, and then endless
     50  * loop on waiting for and processing requests
     51  */
     52 #include <sys/types.h>
     53 #include <sys/socket.h>
     54 #include <sys/param.h>
     55 
     56 #include <protocols/talkd.h>
     57 
     58 #include <errno.h>
     59 #include <paths.h>
     60 #include <signal.h>
     61 #include <stdio.h>
     62 #include <stdlib.h>
     63 #include <string.h>
     64 #include <syslog.h>
     65 #include <time.h>
     66 #include <unistd.h>
     67 
     68 #include "extern.h"
     69 
     70 CTL_MSG		request;
     71 CTL_RESPONSE	response;
     72 
     73 int	sockt = STDIN_FILENO;
     74 int	debug = 0;
     75 int	logging = 0;
     76 time_t	lastmsgtime;
     77 
     78 char	hostname[MAXHOSTNAMELEN + 1];
     79 
     80 #define TIMEOUT 30
     81 #define MAXIDLE 120
     82 
     83 static void timeout(int);
     84 int	main(int, char *[]);
     85 
     86 int
     87 main(int argc, char *argv[])
     88 {
     89 	CTL_MSG *mp = &request;
     90 	int cc, ch;
     91 	struct sockaddr ctl_addr;
     92 
     93 	openlog("talkd", LOG_PID, LOG_DAEMON);
     94 	while ((ch = getopt(argc, argv, "dl")) != -1)
     95 		switch (ch) {
     96 		case 'd':
     97 			debug = 1;
     98 			break;
     99 		case 'l':
    100 			logging = 1;
    101 			break;
    102 		default:
    103 			syslog(LOG_ERR, "Usage: %s [-dl]", getprogname());
    104 			exit(1);
    105 		}
    106 
    107 	if (gethostname(hostname, sizeof hostname) < 0) {
    108 		syslog(LOG_ERR, "gethostname: %m");
    109 		_exit(1);
    110 	}
    111 	hostname[MAXHOSTNAMELEN] = '\0';  /* ensure null termination */
    112 	if (chdir(_PATH_DEV) < 0) {
    113 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
    114 		_exit(1);
    115 	}
    116 	signal(SIGALRM, timeout);
    117 	alarm(TIMEOUT);
    118 	for (;;) {
    119 		memset(&response, 0, sizeof(response));
    120 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
    121 		if (cc != sizeof (*mp)) {
    122 			if (cc < 0 && errno != EINTR)
    123 				syslog(LOG_WARNING, "recv: %m");
    124 			continue;
    125 		}
    126 
    127 		mp->l_name[sizeof(mp->l_name) - 1] = '\0';
    128 		mp->r_name[sizeof(mp->r_name) - 1] = '\0';
    129 		mp->r_tty[sizeof(mp->r_tty) - 1] = '\0';
    130 
    131 		lastmsgtime = time(0);
    132 		process_request(mp, &response);
    133 
    134 		tsa2sa(&ctl_addr, &mp->ctl_addr);
    135 		if (ctl_addr.sa_family != AF_INET)
    136 			continue;
    137 
    138 		/* can block here, is this what I want? */
    139 		cc = sendto(sockt, (char *)&response, sizeof (response), 0,
    140 		    &ctl_addr, sizeof (ctl_addr));
    141 		if (cc != sizeof (response))
    142 			syslog(LOG_WARNING, "sendto: %m");
    143 	}
    144 }
    145 
    146 void
    147 timeout(int n)
    148 {
    149 	int save_errno = errno;
    150 
    151 	if (time(0) - lastmsgtime >= MAXIDLE)
    152 		_exit(0);
    153 	alarm(TIMEOUT);
    154 	errno = save_errno;
    155 }
    156 
    157 void
    158 tsa2sa(struct sockaddr *sa, const struct talkd_sockaddr *tsa)
    159 {
    160 	(void)memcpy(sa, tsa, sizeof(*tsa));
    161 	sa->sa_len = sizeof(*tsa);
    162 	sa->sa_family = tsa->sa_family;
    163 }
    164