Home | History | Annotate | Line # | Download | only in talkd
talkd.c revision 1.16 
      1 /*	$NetBSD: talkd.c,v 1.16 2002/11/20 21:01:57 itojun 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 1.16 2002/11/20 21:01:57 itojun 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 
     62 #include <errno.h>
     63 #include <paths.h>
     64 #include <signal.h>
     65 #include <stdio.h>
     66 #include <stdlib.h>
     67 #include <string.h>
     68 #include <syslog.h>
     69 #include <time.h>
     70 #include <unistd.h>
     71 
     72 #include "extern.h"
     73 
     74 CTL_MSG		request;
     75 CTL_RESPONSE	response;
     76 
     77 int	sockt = STDIN_FILENO;
     78 int	debug = 0;
     79 int	logging = 0;
     80 long	lastmsgtime;
     81 
     82 char	hostname[MAXHOSTNAMELEN + 1];
     83 
     84 #define TIMEOUT 30
     85 #define MAXIDLE 120
     86 
     87 static void timeout __P((int));
     88 int	main __P((int, char *[]));
     89 
     90 int
     91 main(argc, argv)
     92 	int argc;
     93 	char *argv[];
     94 {
     95 	CTL_MSG *mp = &request;
     96 	int cc, ch;
     97 	struct sockaddr ctl_addr;
     98 
     99 	openlog("talkd", LOG_PID, LOG_DAEMON);
    100 	while ((ch = getopt(argc, argv, "dl")) != -1)
    101 		switch (ch) {
    102 		case 'd':
    103 			debug = 1;
    104 			break;
    105 		case 'l':
    106 			logging = 1;
    107 			break;
    108 		default:
    109 			syslog(LOG_ERR, "Usage: %s [-dl]", getprogname());
    110 			exit(1);
    111 		}
    112 
    113 	if (gethostname(hostname, sizeof hostname) < 0) {
    114 		syslog(LOG_ERR, "gethostname: %m");
    115 		_exit(1);
    116 	}
    117 	hostname[MAXHOSTNAMELEN] = '\0';  /* ensure null termination */
    118 	if (chdir(_PATH_DEV) < 0) {
    119 		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
    120 		_exit(1);
    121 	}
    122 	signal(SIGALRM, timeout);
    123 	alarm(TIMEOUT);
    124 	for (;;) {
    125 		memset(&response, 0, sizeof(response));
    126 		cc = recv(0, (char *)mp, sizeof (*mp), 0);
    127 		if (cc != sizeof (*mp)) {
    128 			if (cc < 0 && errno != EINTR)
    129 				syslog(LOG_WARNING, "recv: %m");
    130 			continue;
    131 		}
    132 
    133 		mp->l_name[sizeof(mp->l_name) - 1] = '\0';
    134 		mp->r_name[sizeof(mp->r_name) - 1] = '\0';
    135 		mp->r_tty[sizeof(mp->r_tty) - 1] = '\0';
    136 
    137 		lastmsgtime = time(0);
    138 		process_request(mp, &response);
    139 
    140 		(void)memcpy(&ctl_addr, &mp->ctl_addr, sizeof(ctl_addr));
    141 		ctl_addr.sa_family = mp->ctl_addr.sa_family;
    142 		ctl_addr.sa_len = sizeof(ctl_addr);
    143 		if (ctl_addr.sa_family != AF_INET)
    144 			continue;
    145 
    146 		/* can block here, is this what I want? */
    147 		cc = sendto(sockt, (char *)&response, sizeof (response), 0,
    148 		    &ctl_addr, sizeof (ctl_addr));
    149 		if (cc != sizeof (response))
    150 			syslog(LOG_WARNING, "sendto: %m");
    151 	}
    152 }
    153 
    154 void
    155 timeout(n)
    156 	int n;
    157 {
    158 	int save_errno = errno;
    159 
    160 	if (time(0) - lastmsgtime >= MAXIDLE)
    161 		_exit(0);
    162 	alarm(TIMEOUT);
    163 	errno = save_errno;
    164 }
    165