dgated.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 235 行

#ifndef lint
static	char	*sccsid = "@(#)dgated.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/*
Modification History
~~~~~~~~~~~~~~~~~~~~
07	25-Jul-87, Jim Melvin
	- Added the O_APPEND flag to opens of /etc/utmp.

08	30-Jul-87, Jim Melvin
	- Removed the O_APPEND flag to opens of /etc/utmp.


*/



/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

#include <stdio.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include <netinet/in.h>

#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <sgtty.h>
#include <stdio.h>
#include <netdb.h>
#include <syslog.h>

extern	errno;
int pid, Pfd, netf;
char *line;
/*
 * remote dlogin gateway server:
 */
main(argc, argv)
	int argc;
	char **argv;
{
	int f = 0;
	int on = 1;
	char buf[BUFSIZ];
	int cleanup();
	int child;
	int i, p, cc, t, ppid;
	char c;
	int stop = TIOCPKT_DOSTOP;

	for (c = 'p'; c <= 'z'; c++) {
		struct stat stb;
		line = "/dev/ptyXX";
		line[strlen("/dev/pty")] = c;
		line[strlen("/dev/ptyp")] = '0';
		if (stat(line, &stb) < 0)
			break;
		for (i = 0; i < 16; i++) {
			line[strlen("/dev/ptyp")] = "0123456789abcdef"[i];
			p = open(line, 2);
			if (p > 0)
				goto gotpty;
		}
	}
	openlog("dgated", LOG_PID);
	syslog(LOG_ERR, "All network ports in use");
	closelog();
	exit(1);
	/*NOTREACHED*/
gotpty:
	Pfd = p;
	netf = f;
	line[strlen("/dev/")] = 't';
#ifdef DEBUG
	{ int tt = open("/dev/tty", 2);
	  if (tt > 0) {
		ioctl(tt, TIOCNOTTY, 0);
		(void) close(tt);
	  }
	}
#endif
	t = open(line, 2);
	if (t < 0) {
		openlog("dgated", LOG_PID);
		syslog (LOG_CRIT, "cannot reopen %s", line);
		closelog();
		exit(1);
	}
	{ struct sgttyb b;
	  gtty(t, &b); b.sg_flags = RAW|ANYP; stty(t, &b);
	}
	pid = fork();
	if (pid < 0) {
		openlog("dgated", LOG_PID);
		syslog(LOG_CRIT, "cannot fork");
		closelog();
		exit(1);
	}
	if (pid) {
		char fibuf[1024], *pbp, *fbp;
		register int fcc = 0;
		int on = 1;

		ioctl(f, FIONBIO, &on);
		ioctl(p, FIONBIO, &on);
		ioctl(p, TIOCPKT, &on);
		signal(SIGTSTP, SIG_IGN);
		signal(SIGCHLD, cleanup);
		for (;;) {
			int ibits = 0;
			
			ibits = (1 << f) | (1 << p);
			select(16, &ibits, (int *) 0, (int *) 0, 0);
			if (!ibits)
				continue;
			if (ibits & (1 << f)) {
				fcc = read(f, fibuf, sizeof(fibuf));
				if(fcc)
					write(p, fibuf, fcc);
				else break;
			}
			if (ibits & (1 << p)) {
				fcc = read(p, fibuf, sizeof(fibuf));
				if(fcc)
					write(f, fibuf, fcc);
				else break;
			}
		}
		cleanup();
	}
	(void) close(f);
	(void) close(p);
	(void) dup2(t, 0);
	(void) dup2(t, 1);
	(void) dup2(t, 2);
	(void) close(t);
	argv[0] = "dlogin";
	execve("/usr/bin/dlogin", argv, (char **) 0);
	openlog("dgated", LOG_PID);
	syslog(LOG_ERR, "cannot exec /usr/bin/dlogin");
	closelog();
	exit(1);
	/*NOTREACHED*/
}

cleanup()
{

	rmut();
	signal(SIGHUP, SIG_IGN);
	close(Pfd);
	vhangup();		/* XXX */
	(void) shutdown(netf, 2);
	(void) kill(0, SIGKILL);
	exit(1);
}

#include <utmp.h>

struct	utmp wtmp;
char	wtmpf[]	= "/usr/adm/wtmp";
char	utmp[] = "/etc/utmp";
#define SCPYN(a, b)	(void) strncpy(a, b, sizeof(a))
#define SCMPN(a, b)	strncmp(a, b, sizeof(a))

rmut()
{
	register f;
	int found = 0;

	f = open(utmp, O_RDWR);
	if (f >= 0) {
		while(read(f, (char *)&wtmp, sizeof(wtmp)) == sizeof(wtmp)) {
			if (SCMPN(wtmp.ut_line, line+5) || wtmp.ut_name[0]==0)
				continue;
			(void) lseek(f, -(long)sizeof(wtmp), 1);
			SCPYN(wtmp.ut_name, "");
			SCPYN(wtmp.ut_host, "");
			(void) time(&wtmp.ut_time);
			write(f, (char *)&wtmp, sizeof(wtmp));
			found++;
		}
		(void) close(f);
	}
	if (found) {
		f = open(wtmpf, O_WRONLY|O_APPEND);
		if (f >= 0) {
			SCPYN(wtmp.ut_line, line+5);
			SCPYN(wtmp.ut_name, "");
			SCPYN(wtmp.ut_host, "");
			(void) time(&wtmp.ut_time);
			write(f, (char *)&wtmp, sizeof(wtmp));
			(void) close(f);
		}
	}
	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
	line[strlen("/dev/")] = 'p';
	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
}