1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/* 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());
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);
#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;
}
bb_do_delay(LOGIN_FAIL_DELAY);
puts("Incorrect password");
}
#ifdef __linux__
ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
#endif
tcsetattr_stdin_TCSANOW(&oterm);
fflush_stdout_and_exit(EXIT_SUCCESS);
}
|
