xref: /freebsd/usr.bin/lock/lock.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 <pwd.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <syslog.h>
71 #include <termios.h>
72 #include <unistd.h>
73 
74 #define	TIMEOUT	15
75 
76 void quit(int);
77 void bye(int);
78 void hi(int);
79 static void usage(void);
80 
81 struct timeval	timeout;
82 struct timeval	zerotime;
83 struct termios	tty, ntty;
84 long	nexttime;			/* keep the timeout time */
85 int            no_timeout;                     /* lock terminal forever */
86 int	vtyunlock;			/* Unlock flag and code. */
87 
88 /*ARGSUSED*/
89 int
90 main(int argc, char **argv)
91 {
92 	struct passwd *pw;
93 	struct timeval timval;
94 	time_t timval_sec;
95 	struct itimerval ntimer, otimer;
96 	struct tm *timp;
97 	int ch, failures, sectimeout, usemine, vtylock;
98 	char *ap, *mypw, *ttynam, *tzn;
99 	char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
100 
101 	openlog("lock", LOG_ODELAY, LOG_AUTH);
102 
103 	sectimeout = TIMEOUT;
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 (gettimeofday(&timval, (struct timezone *)NULL))
140 		err(1, "gettimeofday");
141 	nexttime = timval.tv_sec + (sectimeout * 60);
142 	timval_sec = timval.tv_sec;
143 	timp = localtime(&timval_sec);
144 	ap = asctime(timp);
145 	tzn = timp->tm_zone;
146 
147 	(void)signal(SIGINT, quit);
148 	(void)signal(SIGQUIT, quit);
149 	ntty = tty; ntty.c_lflag &= ~ECHO;
150 	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty);
151 
152 	if (!mypw) {
153 		/* get key and check again */
154 		(void)printf("Key: ");
155 		if (!fgets(s, sizeof(s), stdin) || *s == '\n')
156 			quit(0);
157 		(void)printf("\nAgain: ");
158 		/*
159 		 * Don't need EOF test here, if we get EOF, then s1 != s
160 		 * and the right things will happen.
161 		 */
162 		(void)fgets(s1, sizeof(s1), stdin);
163 		(void)putchar('\n');
164 		if (strcmp(s1, s)) {
165 			(void)printf("\07lock: passwords didn't match.\n");
166 			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
167 			exit(1);
168 		}
169 		s[0] = '\0';
170 		mypw = s1;
171 	}
172 
173 	/* set signal handlers */
174 	(void)signal(SIGINT, hi);
175 	(void)signal(SIGQUIT, hi);
176 	(void)signal(SIGTSTP, hi);
177 	(void)signal(SIGALRM, bye);
178 
179 	ntimer.it_interval = zerotime;
180 	ntimer.it_value = timeout;
181 	if (!no_timeout)
182 		setitimer(ITIMER_REAL, &ntimer, &otimer);
183 	if (vtylock) {
184 		/*
185 		 * If this failed, we want to err out; warn isn't good
186 		 * enough, since we don't want the user to think that
187 		 * everything is nice and locked because they got a
188 		 * "Key:" prompt.
189 		 */
190 		if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) {
191 			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
192 			err(1, "locking vty");
193 		}
194 		vtyunlock = 0x2;
195 	}
196 
197 	/* header info */
198 	(void)printf("lock: %s on %s.", ttynam, hostname);
199 	if (no_timeout)
200 		(void)printf(" no timeout.");
201 	else
202 		(void)printf(" timeout in %d minute%s.", sectimeout,
203 		    sectimeout != 1 ? "s" : "");
204 	if (vtylock)
205 		(void)printf(" vty locked.");
206 	(void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
207 
208 	failures = 0;
209 
210 	for (;;) {
211 		(void)printf("Key: ");
212 		if (!fgets(s, sizeof(s), stdin)) {
213 			clearerr(stdin);
214 			hi(0);
215 			continue;
216 		}
217 		if (usemine) {
218 			s[strlen(s) - 1] = '\0';
219 			if (!strcmp(mypw, crypt(s, mypw)))
220 				break;
221 		}
222 		else if (!strcmp(s, s1))
223 			break;
224 		(void)printf("\07\n");
225 	    	failures++;
226 		if (getuid() == 0)
227 	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
228 			failures, failures > 1 ? "S": "", ttynam, hostname);
229 		if (tcgetattr(0, &ntty))
230 			exit(1);
231 		sleep(1);		/* to discourage guessing */
232 	}
233 	if (getuid() == 0)
234 		syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
235 		    hostname, ttynam);
236 	quit(0);
237 	return(0); /* not reached */
238 }
239 
240 
241 static void
242 usage(void)
243 {
244 	(void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
245 	exit(1);
246 }
247 
248 void
249 hi(int signo __unused)
250 {
251 	struct timeval timval;
252 
253 	if (!gettimeofday(&timval, (struct timezone *)NULL)) {
254 		(void)printf("lock: type in the unlock key. ");
255 		if (no_timeout) {
256 			(void)putchar('\n');
257 		} else {
258 			(void)printf("timeout in %ld:%ld minutes\n",
259 			    (nexttime - timval.tv_sec) / 60,
260 			    (nexttime - timval.tv_sec) % 60);
261 		}
262 	}
263 }
264 
265 void
266 quit(int signo __unused)
267 {
268 	(void)putchar('\n');
269 	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
270 	if (vtyunlock)
271 		(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
272 	exit(0);
273 }
274 
275 void
276 bye(int signo __unused)
277 {
278 	if (!no_timeout) {
279 		(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
280 		if (vtyunlock)
281 			(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
282 		(void)printf("lock: timeout\n");
283 		exit(1);
284 	}
285 }
286