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/* vlock.c -- main routine for vlock, the VT locking program for linux
*
* This program is copyright (C) 1994 Michael K. Johnson, and is free
* software which is freely distributable under the terms of the
* GNU public license, included as the file COPYING in this
* distribution. It is NOT public domain software, and any
* redistribution not permitted by the GNU General Public License is
* expressly forbidden without prior written permission from
* the author.
*
*/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <getopt.h>
#include <termios.h>
#include <signal.h>
#include <sys/vt.h>
#include <sys/kd.h>
#include <sys/ioctl.h>
#include "vlock.h"
#include "version.h"
/* Option globals */
/* This determines whether the default behavior is to lock only the */
/* current VT or all of them. 0 means current, 1 means all. */
int o_lock_all = 0;
/* Other globals */
struct vt_mode ovtm;
struct termios oterm;
int vfd;
int is_vt;
int main(int argc, char **argv) {
static struct option long_options[] = { /* For parsing long arguments */
{"current", 0, &o_lock_all, 0},
{"all", 0, &o_lock_all, 1},
{"version", no_argument, 0, O_VERSION},
{"help", no_argument, 0, O_HELP},
{0, 0, 0, 0},
};
int option_index; /* Unused */
int c;
struct vt_mode vtm;
/* First we parse all the command line arguments */
while ((c = getopt_long(argc, argv, "acvh",
long_options, &option_index)) != -1) {
switch(c) {
case 'c':
o_lock_all = 0;
break;
case 'a':
o_lock_all = 1;
break;
case 'v':
case O_VERSION:
fprintf(stderr, VERSION);
exit(0);
break;
case 'h':
case O_HELP:
print_help(0);
break;
case '?':
print_help(1);
break;
}
}
/* Now we have parsed the options, and can get on with life */
/* Get the user's and root's encrypted passwords. This needs
to run as root when using shadow passwords, but will drop
root privileges as soon as they are no longer needed. */
init_passwords();
if ((vfd = open("/dev/tty", O_RDWR)) < 0) {
perror("vlock: could not open /dev/tty");
exit (1);
}
/* First we will set process control of VC switching; if this fails, */
/* then we know that we aren't on a VC, and will print a warning message */
/* If it doesn't fail, it gets the current VT status... */
c = ioctl(vfd, VT_GETMODE, &vtm);
if (c < 0) {
fprintf(stderr, " *** This tty is not a VC (virtual console). ***\n"
" *** It may not be securely locked. ***\n\n");
is_vt = 0;
o_lock_all = 0;
} else {
is_vt = 1;
}
/* Now set the signals so we can't be summarily executed or stopped, */
/* and handle SIGUSR{1,2} and SIGCHLD */
mask_signals();
if (is_vt) {
clear_screen();
ovtm = vtm; /* Keep a copy around to restore at appropriate times */
vtm.mode = VT_PROCESS;
vtm.relsig = SIGUSR1; /* handled by release_vt() */
vtm.acqsig = SIGUSR2; /* handled by acquire_vt() */
ioctl(vfd, VT_SETMODE, &vtm);
}
/* get_password() sets the terminal characteristics and does not */
/* return until the correct password has been read. */
get_password();
/* vt status was restored in restore_terminal() already... */
if (is_vt) restore_screen();
/* we should really return something... */
return (0);
}
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