xref: /csrg-svn/libexec/talkd/talkd.c (revision 22401)
1*22401Sdist /*
2*22401Sdist  * Copyright (c) 1983 Regents of the University of California.
3*22401Sdist  * All rights reserved.  The Berkeley software License Agreement
4*22401Sdist  * specifies the terms and conditions for redistribution.
5*22401Sdist  */
6*22401Sdist 
716366Skarels #ifndef lint
8*22401Sdist char copyright[] =
9*22401Sdist "@(#) Copyright (c) 1983 Regents of the University of California.\n\
10*22401Sdist  All rights reserved.\n";
11*22401Sdist #endif not lint
1216360Skarels 
13*22401Sdist #ifndef lint
14*22401Sdist static char sccsid[] = "@(#)talkd.c	5.1 (Berkeley) 06/06/85";
15*22401Sdist #endif not lint
16*22401Sdist 
1716366Skarels /*
1816366Skarels  * The top level of the daemon, the format is heavily borrowed
1916366Skarels  * from rwhod.c. Basically: find out who and where you are;
2016366Skarels  * disconnect all descriptors and ttys, and then endless
2116366Skarels  * loop on waiting for and processing requests
2216360Skarels  */
2316360Skarels #include <stdio.h>
2416360Skarels #include <errno.h>
2516366Skarels #include <signal.h>
2616360Skarels 
2716366Skarels #include "ctl.h"
2816360Skarels 
2916360Skarels struct	sockaddr_in sin = { AF_INET };
3016360Skarels 
3116366Skarels CTL_MSG		request;
3216366Skarels CTL_RESPONSE	response;
3316360Skarels 
3416366Skarels int	sockt;
3516366Skarels int	debug = 0;
3616467Slayer FILE	*debugout;
3716366Skarels int	timeout();
3816366Skarels long	lastmsgtime;
3916360Skarels 
4016366Skarels char	hostname[32];
4116360Skarels 
4216366Skarels #define TIMEOUT 30
4316366Skarels #define MAXIDLE 120
4416366Skarels 
4516366Skarels main(argc, argv)
4616366Skarels 	int argc;
4716366Skarels 	char *argv[];
4816360Skarels {
4916366Skarels 	struct sockaddr_in from;
5016366Skarels 	int fromlen, cc;
5116467Slayer 
5216467Slayer 	if (debug)
5316467Slayer 		debugout = (FILE *)fopen ("/usr/tmp/talkd.msgs", "w");
5416360Skarels 
5516366Skarels 	if (getuid()) {
5616366Skarels 		fprintf(stderr, "Talkd : not super user\n");
5716366Skarels 		exit(1);
5816360Skarels 	}
5916366Skarels 	gethostname(hostname, sizeof (hostname));
6016366Skarels 	(void) chdir("/dev");
6116366Skarels 	signal(SIGALRM, timeout);
6216366Skarels 	alarm(TIMEOUT);
6316366Skarels 	for (;;) {
6416366Skarels 		extern int errno;
6516360Skarels 
6616366Skarels 		fromlen = sizeof(from);
6716366Skarels 		cc = recvfrom(0, (char *)&request, sizeof (request), 0,
6816366Skarels 		    &from, &fromlen);
6916366Skarels 		if (cc != sizeof(request)) {
7016366Skarels 			if (cc < 0 && errno != EINTR)
7116366Skarels 			perror("recvfrom");
7216366Skarels 			continue;
7316366Skarels 		}
7416366Skarels 		lastmsgtime = time(0);
7516467Slayer 		swapmsg(&request);
7617567Sbloom 		if (debug) print_request(&request);
7716366Skarels 		process_request(&request, &response);
7816360Skarels 		/* can block here, is this what I want? */
7916366Skarels 		cc = sendto(sockt, (char *) &response,
8016366Skarels 		    sizeof (response), 0, &request.ctl_addr,
8116366Skarels 		    sizeof (request.ctl_addr));
8216366Skarels 		if (cc != sizeof(response))
8316366Skarels 			perror("sendto");
8416360Skarels 	}
8516360Skarels }
8616360Skarels 
8716366Skarels timeout()
8816360Skarels {
8916360Skarels 
9016366Skarels 	if (time(0) - lastmsgtime >= MAXIDLE)
9116366Skarels 		exit(0);
9216366Skarels 	alarm(TIMEOUT);
9316360Skarels }
9416467Slayer 
9516467Slayer /*
9616467Slayer  * heuristic to detect if need to swap bytes
9716467Slayer  */
9816467Slayer 
9916467Slayer swapmsg(req)
10016467Slayer 	CTL_MSG *req;
10116467Slayer {
10217567Sbloom 	if (req->ctl_addr.sin_family == ntohs(AF_INET)) {
10317567Sbloom 		req->id_num = ntohl(req->id_num);
10417567Sbloom 		req->pid = ntohl(req->pid);
10517567Sbloom 		req->addr.sin_family = ntohs(req->addr.sin_family);
10616467Slayer 		req->ctl_addr.sin_family =
10717567Sbloom 			ntohs(req->ctl_addr.sin_family);
10816467Slayer 	}
10916467Slayer }
110