xref: /freebsd/usr.bin/lock/lock.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
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  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1980, 1987, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)lock.c	8.1 (Berkeley) 6/6/93";
46 #endif
47 #endif /* not lint */
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 /*
52  * Lock a terminal up until the given key is entered or the given
53  * interval times out.
54  *
55  * Timeout interval is by default TIMEOUT, it can be changed with
56  * an argument of the form -time where time is in minutes
57  */
58 
59 #include <sys/param.h>
60 #include <sys/stat.h>
61 #include <sys/time.h>
62 #include <sys/signal.h>
63 #include <sys/consio.h>
64 #include <err.h>
65 #include <ctype.h>
66 #include <errno.h>
67 #include <pwd.h>
68 #include <stdint.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <syslog.h>
73 #include <termios.h>
74 #include <unistd.h>
75 
76 #define	TIMEOUT	15
77 
78 void quit(int);
79 void bye(int);
80 void hi(int);
81 static void usage(void);
82 
83 struct timeval	timeout;
84 struct timeval	zerotime;
85 struct termios	tty, ntty;
86 long	nexttime;			/* keep the timeout time */
87 int            no_timeout;                     /* lock terminal forever */
88 int	vtyunlock;			/* Unlock flag and code. */
89 
90 /*ARGSUSED*/
91 int
92 main(int argc, char **argv)
93 {
94 	struct passwd *pw;
95 	struct timeval timval;
96 	time_t timval_sec;
97 	struct itimerval ntimer, otimer;
98 	struct tm *timp;
99 	int ch, failures, sectimeout, usemine, vtylock;
100 	char *ap, *mypw, *ttynam, *tzn;
101 	char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
102 
103 	openlog("lock", LOG_ODELAY, LOG_AUTH);
104 
105 	sectimeout = TIMEOUT;
106 	mypw = NULL;
107 	usemine = 0;
108 	no_timeout = 0;
109 	vtylock = 0;
110 	while ((ch = getopt(argc, argv, "npt:v")) != -1)
111 		switch((char)ch) {
112 		case 't':
113 			if ((sectimeout = atoi(optarg)) <= 0)
114 				errx(1, "illegal timeout value");
115 			break;
116 		case 'p':
117 			usemine = 1;
118 			if (!(pw = getpwuid(getuid())))
119 				errx(1, "unknown uid %d", getuid());
120 			mypw = strdup(pw->pw_passwd);
121 			break;
122 		case 'n':
123 			no_timeout = 1;
124 			break;
125 		case 'v':
126 			vtylock = 1;
127 			break;
128 		case '?':
129 		default:
130 			usage();
131 		}
132 	timeout.tv_sec = sectimeout * 60;
133 
134 	setuid(getuid());		/* discard privs */
135 
136 	if (tcgetattr(0, &tty))		/* get information for header */
137 		exit(1);
138 	gethostname(hostname, sizeof(hostname));
139 	if (!(ttynam = ttyname(0)))
140 		errx(1, "not a terminal?");
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 	(void)printf("lock: %s on %s.", ttynam, hostname);
201 	if (no_timeout)
202 		(void)printf(" no timeout.");
203 	else
204 		(void)printf(" timeout in %d minute%s.", sectimeout,
205 		    sectimeout != 1 ? "s" : "");
206 	if (vtylock)
207 		(void)printf(" vty locked.");
208 	(void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
209 
210 	failures = 0;
211 
212 	for (;;) {
213 		(void)printf("Key: ");
214 		if (!fgets(s, sizeof(s), stdin)) {
215 			clearerr(stdin);
216 			hi(0);
217 			goto tryagain;
218 		}
219 		if (usemine) {
220 			s[strlen(s) - 1] = '\0';
221 			if (!strcmp(mypw, crypt(s, mypw)))
222 				break;
223 		}
224 		else if (!strcmp(s, s1))
225 			break;
226 		(void)printf("\07\n");
227 	    	failures++;
228 		if (getuid() == 0)
229 	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
230 			failures, failures > 1 ? "S": "", ttynam, hostname);
231 tryagain:
232 		if (tcgetattr(0, &ntty) && (errno != EINTR))
233 			exit(1);
234 		sleep(1);		/* to discourage guessing */
235 	}
236 	if (getuid() == 0)
237 		syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
238 		    hostname, ttynam);
239 	quit(0);
240 	return(0); /* not reached */
241 }
242 
243 
244 static void
245 usage(void)
246 {
247 	(void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
248 	exit(1);
249 }
250 
251 void
252 hi(int signo __unused)
253 {
254 	struct timeval timval;
255 
256 	if (!gettimeofday(&timval, (struct timezone *)NULL)) {
257 		(void)printf("lock: type in the unlock key. ");
258 		if (no_timeout) {
259 			(void)putchar('\n');
260 		} else {
261 			(void)printf("timeout in %jd:%jd minutes\n",
262 			    (intmax_t)(nexttime - timval.tv_sec) / 60,
263 			    (intmax_t)(nexttime - timval.tv_sec) % 60);
264 		}
265 	}
266 }
267 
268 void
269 quit(int signo __unused)
270 {
271 	(void)putchar('\n');
272 	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
273 	if (vtyunlock)
274 		(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
275 	exit(0);
276 }
277 
278 void
279 bye(int signo __unused)
280 {
281 	if (!no_timeout) {
282 		(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
283 		if (vtyunlock)
284 			(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
285 		(void)printf("lock: timeout\n");
286 		exit(1);
287 	}
288 }
289