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/* vi: set sw=4 ts=4: */
/*
* vlock implementation for busybox
*
* Copyright (C) 2000 by spoon <spoon@ix.netcom.com>
* Written by spoon <spon@ix.netcom.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* Shoutz to Michael K. Johnson <johnsonm@redhat.com>, author of the
* original vlock. I snagged a bunch of his code to write this
* minimalistic vlock.
*/
/* Fixed by Erik Andersen to do passwords the tinylogin way...
* It now works with md5, sha1, etc passwords.
*/
//config:config VLOCK
//config: bool "vlock (17 kb)"
//config: default y
//config: help
//config: Build the "vlock" applet which allows you to lock (virtual) terminals.
//config:
//config: Note that busybox binary must be setuid root for this applet to
//config: work properly.
//applet:/* Needs to be run by root or be suid root - needs to change uid and gid: */
//applet:IF_VLOCK(APPLET(vlock, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
//kbuild:lib-$(CONFIG_VLOCK) += vlock.o
//usage:#define vlock_trivial_usage
//usage: "[-a]"
//usage:#define vlock_full_usage "\n\n"
//usage: "Lock a virtual terminal. A password is required to unlock.\n"
//usage: "\n -a Lock all VTs"
#include "libbb.h"
#ifdef __linux__
#include <sys/vt.h>
static void release_vt(int signo UNUSED_PARAM)
{
/* If -a, param is 0, which means:
* "no, kernel, we don't allow console switch away from us!" */
ioctl(STDIN_FILENO, VT_RELDISP, (unsigned long) !option_mask32);
}
static void acquire_vt(int signo UNUSED_PARAM)
{
/* ACK to kernel that switch to console is successful */
ioctl(STDIN_FILENO, VT_RELDISP, VT_ACKACQ);
}
#endif
int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int vlock_main(int argc UNUSED_PARAM, char **argv)
{
#ifdef __linux__
struct vt_mode vtm;
struct vt_mode ovtm;
#endif
struct termios term;
struct termios oterm;
struct passwd *pw;
pw = xgetpwuid(getuid());
getopt32(argv, "^" "a" "\0" "=0"/* no args!*/);
/* Ignore some signals so that we don't get killed by them */
bb_signals(0
+ (1 << SIGTSTP)
+ (1 << SIGTTIN)
+ (1 << SIGTTOU)
+ (1 << SIGHUP )
+ (1 << SIGCHLD) /* paranoia :) */
+ (1 << SIGQUIT)
+ (1 << SIGINT )
, SIG_IGN);
#ifdef __linux__
/* We will use SIGUSRx for console switch control: */
/* 1: set handlers */
signal_SA_RESTART_empty_mask(SIGUSR1, release_vt);
signal_SA_RESTART_empty_mask(SIGUSR2, acquire_vt);
/* 2: unmask them */
sig_unblock(SIGUSR1);
sig_unblock(SIGUSR2);
#endif
/* Revert stdin/out to our controlling tty
* (or die if we have none) */
xmove_fd(xopen(CURRENT_TTY, O_RDWR), STDIN_FILENO);
xdup2(STDIN_FILENO, STDOUT_FILENO);
#ifdef __linux__
xioctl(STDIN_FILENO, VT_GETMODE, &vtm);
ovtm = vtm;
/* "console switches are controlled by us, not kernel!" */
vtm.mode = VT_PROCESS;
vtm.relsig = SIGUSR1;
vtm.acqsig = SIGUSR2;
ioctl(STDIN_FILENO, VT_SETMODE, &vtm);
#endif
//TODO: use set_termios_to_raw()
tcgetattr(STDIN_FILENO, &oterm);
term = oterm;
term.c_iflag |= IGNBRK; /* ignore serial break (why? VTs don't have breaks, right?) */
term.c_iflag &= ~BRKINT; /* redundant? "dont translate break to SIGINT" */
term.c_lflag &= ~(ISIG | ECHO | ECHOCTL); /* ignore ^C ^Z, echo off */
tcsetattr_stdin_TCSANOW(&term);
while (1) {
printf("Virtual console%s locked by %s.\n",
/* "s" if -a, else "": */ "s" + !option_mask32,
pw->pw_name
);
if (ask_and_check_password(pw) > 0) {
break;
}
pause_after_failed_login();
puts("Incorrect password");
}
#ifdef __linux__
ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
#endif
tcsetattr_stdin_TCSANOW(&oterm);
fflush_stdout_and_exit_SUCCESS();
}
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