| /* 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 tarball for details. |
| */ |
| |
| /* 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. */ |
| |
| #include <sys/vt.h> |
| #include "libbb.h" |
| |
| static void release_vt(int signo) |
| { |
| /* 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) |
| { |
| /* ACK to kernel that switch to console is successful */ |
| ioctl(STDIN_FILENO, VT_RELDISP, VT_ACKACQ); |
| } |
| |
| int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int vlock_main(int argc, char **argv) |
| { |
| struct vt_mode vtm; |
| struct termios term; |
| struct termios oterm; |
| struct vt_mode ovtm; |
| uid_t uid; |
| struct passwd *pw; |
| |
| uid = getuid(); |
| pw = getpwuid(uid); |
| if (pw == NULL) |
| bb_error_msg_and_die("unknown uid %d", (int)uid); |
| |
| opt_complementary = "=0"; /* no params! */ |
| getopt32(argv, "a"); |
| |
| /* 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); |
| |
| /* 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); |
| |
| /* 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); |
| |
| 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); |
| |
| tcgetattr(STDIN_FILENO, &oterm); |
| term = oterm; |
| term.c_iflag &= ~BRKINT; |
| term.c_iflag |= IGNBRK; |
| term.c_lflag &= ~ISIG; |
| term.c_lflag &= ~(ECHO | ECHOCTL); |
| tcsetattr(STDIN_FILENO, TCSANOW, &term); |
| |
| do { |
| printf("Virtual console%s locked by %s.\n", |
| option_mask32 /*o_lock_all*/ ? "s" : "", |
| pw->pw_name); |
| if (correct_password(pw)) { |
| break; |
| } |
| bb_do_delay(FAIL_DELAY); |
| puts("Password incorrect"); |
| } while (1); |
| |
| ioctl(STDIN_FILENO, VT_SETMODE, &ovtm); |
| tcsetattr(STDIN_FILENO, TCSANOW, &oterm); |
| fflush_stdout_and_exit(0); |
| } |