lock.c revision 227169 
1/*
2 * Copyright (c) 1980, 1987, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Bob Toxen.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34static const char copyright[] =
35"@(#) Copyright (c) 1980, 1987, 1993\n\
36	The Regents of the University of California.  All rights reserved.\n";
37#endif /* not lint */
38
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)lock.c	8.1 (Berkeley) 6/6/93";
42#endif
43#endif /* not lint */
44#include <sys/cdefs.h>
45__FBSDID("$FreeBSD: head/usr.bin/lock/lock.c 227169 2011-11-06 08:15:48Z ed $");
46
47/*
48 * Lock a terminal up until the given key is entered or the given
49 * interval times out.
50 *
51 * Timeout interval is by default TIMEOUT, it can be changed with
52 * an argument of the form -time where time is in minutes
53 */
54
55#include <sys/param.h>
56#include <sys/stat.h>
57#include <sys/time.h>
58#include <sys/signal.h>
59#include <sys/consio.h>
60#include <err.h>
61#include <ctype.h>
62#include <errno.h>
63#include <paths.h>
64#include <pwd.h>
65#include <stdint.h>
66#include <stdio.h>
67#include <stdlib.h>
68#include <string.h>
69#include <syslog.h>
70#include <termios.h>
71#include <unistd.h>
72
73#define	TIMEOUT	15
74
75static void quit(int);
76static void bye(int);
77static void hi(int);
78static void usage(void);
79
80static struct timeval	timeout;
81static struct timeval	zerotime;
82static struct termios	tty, ntty;
83static long		nexttime;		/* keep the timeout time */
84static int		no_timeout;		/* lock terminal forever */
85static int		vtyunlock;		/* Unlock flag and code. */
86
87/*ARGSUSED*/
88int
89main(int argc, char **argv)
90{
91	struct passwd *pw;
92	struct timeval timval;
93	time_t timval_sec;
94	struct itimerval ntimer, otimer;
95	struct tm *timp;
96	int ch, failures, sectimeout, usemine, vtylock;
97	char *ap, *mypw, *ttynam, *tzn;
98	char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
99
100	openlog("lock", LOG_ODELAY, LOG_AUTH);
101
102	sectimeout = TIMEOUT;
103	pw = NULL;
104	mypw = NULL;
105	usemine = 0;
106	no_timeout = 0;
107	vtylock = 0;
108	while ((ch = getopt(argc, argv, "npt:v")) != -1)
109		switch((char)ch) {
110		case 't':
111			if ((sectimeout = atoi(optarg)) <= 0)
112				errx(1, "illegal timeout value");
113			break;
114		case 'p':
115			usemine = 1;
116			if (!(pw = getpwuid(getuid())))
117				errx(1, "unknown uid %d", getuid());
118			mypw = strdup(pw->pw_passwd);
119			break;
120		case 'n':
121			no_timeout = 1;
122			break;
123		case 'v':
124			vtylock = 1;
125			break;
126		case '?':
127		default:
128			usage();
129		}
130	timeout.tv_sec = sectimeout * 60;
131
132	setuid(getuid());		/* discard privs */
133
134	if (tcgetattr(0, &tty))		/* get information for header */
135		exit(1);
136	gethostname(hostname, sizeof(hostname));
137	if (!(ttynam = ttyname(0)))
138		errx(1, "not a terminal?");
139	if (strncmp(ttynam, _PATH_DEV, strlen(_PATH_DEV)) == 0)
140		ttynam += strlen(_PATH_DEV);
141	if (gettimeofday(&timval, (struct timezone *)NULL))
142		err(1, "gettimeofday");
143	nexttime = timval.tv_sec + (sectimeout * 60);
144	timval_sec = timval.tv_sec;
145	timp = localtime(&timval_sec);
146	ap = asctime(timp);
147	tzn = timp->tm_zone;
148
149	(void)signal(SIGINT, quit);
150	(void)signal(SIGQUIT, quit);
151	ntty = tty; ntty.c_lflag &= ~ECHO;
152	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty);
153
154	if (!mypw) {
155		/* get key and check again */
156		(void)printf("Key: ");
157		if (!fgets(s, sizeof(s), stdin) || *s == '\n')
158			quit(0);
159		(void)printf("\nAgain: ");
160		/*
161		 * Don't need EOF test here, if we get EOF, then s1 != s
162		 * and the right things will happen.
163		 */
164		(void)fgets(s1, sizeof(s1), stdin);
165		(void)putchar('\n');
166		if (strcmp(s1, s)) {
167			(void)printf("\07lock: passwords didn't match.\n");
168			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
169			exit(1);
170		}
171		s[0] = '\0';
172		mypw = s1;
173	}
174
175	/* set signal handlers */
176	(void)signal(SIGINT, hi);
177	(void)signal(SIGQUIT, hi);
178	(void)signal(SIGTSTP, hi);
179	(void)signal(SIGALRM, bye);
180
181	ntimer.it_interval = zerotime;
182	ntimer.it_value = timeout;
183	if (!no_timeout)
184		setitimer(ITIMER_REAL, &ntimer, &otimer);
185	if (vtylock) {
186		/*
187		 * If this failed, we want to err out; warn isn't good
188		 * enough, since we don't want the user to think that
189		 * everything is nice and locked because they got a
190		 * "Key:" prompt.
191		 */
192		if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) {
193			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
194			err(1, "locking vty");
195		}
196		vtyunlock = 0x2;
197	}
198
199	/* header info */
200	if (pw != NULL)
201		(void)printf("lock: %s using %s on %s.", pw->pw_name,
202		    ttynam, hostname);
203	else
204		(void)printf("lock: %s on %s.", ttynam, hostname);
205	if (no_timeout)
206		(void)printf(" no timeout.");
207	else
208		(void)printf(" timeout in %d minute%s.", sectimeout,
209		    sectimeout != 1 ? "s" : "");
210	if (vtylock)
211		(void)printf(" vty locked.");
212	(void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
213
214	failures = 0;
215
216	for (;;) {
217		(void)printf("Key: ");
218		if (!fgets(s, sizeof(s), stdin)) {
219			clearerr(stdin);
220			hi(0);
221			goto tryagain;
222		}
223		if (usemine) {
224			s[strlen(s) - 1] = '\0';
225			if (!strcmp(mypw, crypt(s, mypw)))
226				break;
227		}
228		else if (!strcmp(s, s1))
229			break;
230		(void)printf("\07\n");
231	    	failures++;
232		if (getuid() == 0)
233	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
234			failures, failures > 1 ? "S": "", ttynam, hostname);
235tryagain:
236		if (tcgetattr(0, &ntty) && (errno != EINTR))
237			exit(1);
238		sleep(1);		/* to discourage guessing */
239	}
240	if (getuid() == 0)
241		syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
242		    hostname, ttynam);
243	quit(0);
244	return(0); /* not reached */
245}
246
247
248static void
249usage(void)
250{
251	(void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
252	exit(1);
253}
254
255static void
256hi(int signo __unused)
257{
258	struct timeval timval;
259
260	if (!gettimeofday(&timval, (struct timezone *)NULL)) {
261		(void)printf("lock: type in the unlock key. ");
262		if (no_timeout) {
263			(void)putchar('\n');
264		} else {
265			(void)printf("timeout in %jd:%jd minutes\n",
266			    (intmax_t)(nexttime - timval.tv_sec) / 60,
267			    (intmax_t)(nexttime - timval.tv_sec) % 60);
268		}
269	}
270}
271
272static void
273quit(int signo __unused)
274{
275	(void)putchar('\n');
276	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
277	if (vtyunlock)
278		(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
279	exit(0);
280}
281
282static void
283bye(int signo __unused)
284{
285	if (!no_timeout) {
286		(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
287		if (vtyunlock)
288			(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
289		(void)printf("lock: timeout\n");
290		exit(1);
291	}
292}
293