busybox/loginutils/vlock.c

/* 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 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);
}

int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int vlock_main(int argc UNUSED_PARAM, char **argv)
{
	struct vt_mode vtm;
	struct termios term;
	struct termios oterm;
	struct vt_mode ovtm;
	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);

	/* 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_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_TCSANOW(&oterm);
	fflush_stdout_and_exit(EXIT_SUCCESS);
}
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 tarball for details.
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	#include <sys/vt.h>
19	#include "libbb.h"
20
21	static void release_vt(int signo UNUSED_PARAM)
22	{
23	/* If -a, param is 0, which means:
24	* "no, kernel, we don't allow console switch away from us!" */
25	ioctl(STDIN_FILENO, VT_RELDISP, (unsigned long) !option_mask32);
26	}
27
28	static void acquire_vt(int signo UNUSED_PARAM)
29	{
30	/* ACK to kernel that switch to console is successful */
31	ioctl(STDIN_FILENO, VT_RELDISP, VT_ACKACQ);
32	}
33
34	int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
35	int vlock_main(int argc UNUSED_PARAM, char **argv)
36	{
37	struct vt_mode vtm;
38	struct termios term;
39	struct termios oterm;
40	struct vt_mode ovtm;
41	struct passwd *pw;
42
43	pw = xgetpwuid(getuid());
44	opt_complementary = "=0"; /* no params! */
45	getopt32(argv, "a");
46
47	/* Ignore some signals so that we don't get killed by them */
48	bb_signals(0
49	+ (1 << SIGTSTP)
50	+ (1 << SIGTTIN)
51	+ (1 << SIGTTOU)
52	+ (1 << SIGHUP )
53	+ (1 << SIGCHLD) /* paranoia :) */
54	+ (1 << SIGQUIT)
55	+ (1 << SIGINT )
56	, SIG_IGN);
57
58	/* We will use SIGUSRx for console switch control: */
59	/* 1: set handlers */
60	signal_SA_RESTART_empty_mask(SIGUSR1, release_vt);
61	signal_SA_RESTART_empty_mask(SIGUSR2, acquire_vt);
62	/* 2: unmask them */
63	sig_unblock(SIGUSR1);
64	sig_unblock(SIGUSR2);
65
66	/* Revert stdin/out to our controlling tty
67	* (or die if we have none) */
68	xmove_fd(xopen(CURRENT_TTY, O_RDWR), STDIN_FILENO);
69	xdup2(STDIN_FILENO, STDOUT_FILENO);
70
71	xioctl(STDIN_FILENO, VT_GETMODE, &vtm);
72	ovtm = vtm;
73	/* "console switches are controlled by us, not kernel!" */
74	vtm.mode = VT_PROCESS;
75	vtm.relsig = SIGUSR1;
76	vtm.acqsig = SIGUSR2;
77	ioctl(STDIN_FILENO, VT_SETMODE, &vtm);
78
79	tcgetattr(STDIN_FILENO, &oterm);
80	term = oterm;
81	term.c_iflag &= ~BRKINT;
82	term.c_iflag \|= IGNBRK;
83	term.c_lflag &= ~ISIG;
84	term.c_lflag &= ~(ECHO \| ECHOCTL);
85	tcsetattr_stdin_TCSANOW(&term);
86
87	do {
88	printf("Virtual console%s locked by %s.\n",
89	option_mask32 /o_lock_all/ ? "s" : "",
90	pw->pw_name);
91	if (correct_password(pw)) {
92	break;
93	}
94	bb_do_delay(FAIL_DELAY);
95	puts("Password incorrect");
96	} while (1);
97
98	ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
99	tcsetattr_stdin_TCSANOW(&oterm);
100	fflush_stdout_and_exit(EXIT_SUCCESS);
101	}