source: branches/3.2/mindi-busybox/loginutils/vlock.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 6 years ago
  • Update mindi-busybox to 1.21.1
File size: 2.9 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * vlock implementation for busybox
4 *
5 * Copyright (C) 2000 by spoon <spoon@ix.netcom.com>
6 * Written by spoon <spon@ix.netcom.com>
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9 */
10
11/* Shoutz to Michael K. Johnson <johnsonm@redhat.com>, author of the
12 * original vlock.  I snagged a bunch of his code to write this
13 * minimalistic vlock.
14 */
15/* Fixed by Erik Andersen to do passwords the tinylogin way...
16 * It now works with md5, sha1, etc passwords. */
17
18//usage:#define vlock_trivial_usage
19//usage:       "[-a]"
20//usage:#define vlock_full_usage "\n\n"
21//usage:       "Lock a virtual terminal. A password is required to unlock.\n"
22//usage:     "\n    -a  Lock all VTs"
23
24#include "libbb.h"
25
26#ifdef __linux__
27#include <sys/vt.h>
28
29static void release_vt(int signo UNUSED_PARAM)
30{
31    /* If -a, param is 0, which means:
32     * "no, kernel, we don't allow console switch away from us!" */
33    ioctl(STDIN_FILENO, VT_RELDISP, (unsigned long) !option_mask32);
34}
35
36static void acquire_vt(int signo UNUSED_PARAM)
37{
38    /* ACK to kernel that switch to console is successful */
39    ioctl(STDIN_FILENO, VT_RELDISP, VT_ACKACQ);
40}
41#endif
42
43int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
44int vlock_main(int argc UNUSED_PARAM, char **argv)
45{
46#ifdef __linux__
47    struct vt_mode vtm;
48    struct vt_mode ovtm;
49#endif
50    struct termios term;
51    struct termios oterm;
52    struct passwd *pw;
53
54    pw = xgetpwuid(getuid());
55    opt_complementary = "=0"; /* no params! */
56    getopt32(argv, "a");
57
58    /* Ignore some signals so that we don't get killed by them */
59    bb_signals(0
60        + (1 << SIGTSTP)
61        + (1 << SIGTTIN)
62        + (1 << SIGTTOU)
63        + (1 << SIGHUP )
64        + (1 << SIGCHLD) /* paranoia :) */
65        + (1 << SIGQUIT)
66        + (1 << SIGINT )
67        , SIG_IGN);
68
69#ifdef __linux__
70    /* We will use SIGUSRx for console switch control: */
71    /* 1: set handlers */
72    signal_SA_RESTART_empty_mask(SIGUSR1, release_vt);
73    signal_SA_RESTART_empty_mask(SIGUSR2, acquire_vt);
74    /* 2: unmask them */
75    sig_unblock(SIGUSR1);
76    sig_unblock(SIGUSR2);
77#endif
78
79    /* Revert stdin/out to our controlling tty
80     * (or die if we have none) */
81    xmove_fd(xopen(CURRENT_TTY, O_RDWR), STDIN_FILENO);
82    xdup2(STDIN_FILENO, STDOUT_FILENO);
83
84#ifdef __linux__
85    xioctl(STDIN_FILENO, VT_GETMODE, &vtm);
86    ovtm = vtm;
87    /* "console switches are controlled by us, not kernel!" */
88    vtm.mode = VT_PROCESS;
89    vtm.relsig = SIGUSR1;
90    vtm.acqsig = SIGUSR2;
91    ioctl(STDIN_FILENO, VT_SETMODE, &vtm);
92#endif
93
94    tcgetattr(STDIN_FILENO, &oterm);
95    term = oterm;
96    term.c_iflag &= ~BRKINT;
97    term.c_iflag |= IGNBRK;
98    term.c_lflag &= ~ISIG;
99    term.c_lflag &= ~(ECHO | ECHOCTL);
100    tcsetattr_stdin_TCSANOW(&term);
101
102    while (1) {
103        printf("Virtual console%s locked by %s.\n",
104                /* "s" if -a, else "": */ "s" + !option_mask32,
105                pw->pw_name
106        );
107        if (correct_password(pw)) {
108            break;
109        }
110        bb_do_delay(LOGIN_FAIL_DELAY);
111        puts("Incorrect password");
112    }
113
114#ifdef __linux__
115    ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
116#endif
117    tcsetattr_stdin_TCSANOW(&oterm);
118    fflush_stdout_and_exit(EXIT_SUCCESS);
119}
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