1/* vi: set sw=4 ts=4: */
2
3/*
4 * vlock implementation for busybox
5 *
6 * Copyright (C) 2000 by spoon <spoon@ix.netcom.com>
7 * Written by spoon <spon@ix.netcom.com>
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10 */
11
12/* Shoutz to Michael K. Johnson <johnsonm@redhat.com>, author of the
13 * original vlock.  I snagged a bunch of his code to write this
14 * minimalistic vlock.
15 */
16/* Fixed by Erik Andersen to do passwords the tinylogin way...
17 * It now works with md5, sha1, etc passwords. */
18
19#include "libbb.h"
20#include <sys/vt.h>
21
22static struct passwd *pw;
23static struct vt_mode ovtm;
24static struct termios oterm;
25static int vfd;
26static unsigned long o_lock_all;
27
28static void release_vt(int signo)
29{
30	ioctl(vfd, VT_RELDISP, !o_lock_all);
31}
32
33static void acquire_vt(int signo)
34{
35	ioctl(vfd, VT_RELDISP, VT_ACKACQ);
36}
37
38static void restore_terminal(void)
39{
40	ioctl(vfd, VT_SETMODE, &ovtm);
41	tcsetattr(STDIN_FILENO, TCSANOW, &oterm);
42}
43
44int vlock_main(int argc, char **argv);
45int vlock_main(int argc, char **argv)
46{
47	sigset_t sig;
48	struct sigaction sa;
49	struct vt_mode vtm;
50	struct termios term;
51	uid_t uid = getuid();
52
53	pw = getpwuid(uid);
54	if (pw == NULL)
55		bb_error_msg_and_die("unknown uid %d", uid);
56
57	if (argc > 2) {
58		bb_show_usage();
59	}
60
61	o_lock_all = getopt32(argv, "a");
62
63	vfd = xopen(CURRENT_TTY, O_RDWR);
64
65	xioctl(vfd, VT_GETMODE, &vtm);
66
67	/* mask a bunch of signals */
68	sigprocmask(SIG_SETMASK, NULL, &sig);
69	sigdelset(&sig, SIGUSR1);
70	sigdelset(&sig, SIGUSR2);
71	sigaddset(&sig, SIGTSTP);
72	sigaddset(&sig, SIGTTIN);
73	sigaddset(&sig, SIGTTOU);
74	sigaddset(&sig, SIGHUP);
75	sigaddset(&sig, SIGCHLD);
76	sigaddset(&sig, SIGQUIT);
77	sigaddset(&sig, SIGINT);
78
79	sigemptyset(&(sa.sa_mask));
80	sa.sa_flags = SA_RESTART;
81	sa.sa_handler = release_vt;
82	sigaction(SIGUSR1, &sa, NULL);
83	sa.sa_handler = acquire_vt;
84	sigaction(SIGUSR2, &sa, NULL);
85
86	/* need to handle some signals so that we don't get killed by them */
87	sa.sa_handler = SIG_IGN;
88	sigaction(SIGHUP, &sa, NULL);
89	sigaction(SIGQUIT, &sa, NULL);
90	sigaction(SIGINT, &sa, NULL);
91	sigaction(SIGTSTP, &sa, NULL);
92
93	ovtm = vtm;
94	vtm.mode = VT_PROCESS;
95	vtm.relsig = SIGUSR1;
96	vtm.acqsig = SIGUSR2;
97	ioctl(vfd, VT_SETMODE, &vtm);
98
99	tcgetattr(STDIN_FILENO, &oterm);
100	term = oterm;
101	term.c_iflag &= ~BRKINT;
102	term.c_iflag |= IGNBRK;
103	term.c_lflag &= ~ISIG;
104	term.c_lflag &= ~(ECHO | ECHOCTL);
105	tcsetattr(STDIN_FILENO, TCSANOW, &term);
106
107	do {
108		printf("Virtual Console%s locked by %s.\n", (o_lock_all) ? "s" : "", pw->pw_name);
109		if (correct_password(pw)) {
110			break;
111		}
112		bb_do_delay(FAIL_DELAY);
113		puts("Password incorrect");
114	} while (1);
115	restore_terminal();
116	fflush_stdout_and_exit(0);
117}
118