xref: /dragonfly/usr.bin/lock/lock.c (revision 20c2db9a)
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  * @(#) Copyright (c) 1980, 1987, 1993 The Regents of the University of California.  All rights reserved.
37  * @(#)lock.c	8.1 (Berkeley) 6/6/93
38  * $FreeBSD: src/usr.bin/lock/lock.c,v 1.8.2.1 2002/09/15 22:32:56 dd Exp $
39  */
40 
41 /*
42  * Lock a terminal up until the given key is entered or the given
43  * interval times out.
44  *
45  * Timeout interval is by default TIMEOUT, it can be changed with
46  * an argument of the form -time where time is in minutes
47  */
48 
49 #include <sys/param.h>
50 #include <sys/time.h>
51 #include <sys/consio.h>
52 
53 #include <err.h>
54 #include <pwd.h>
55 #include <errno.h>
56 #include <stdint.h>
57 #include <signal.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <syslog.h>
62 #include <termios.h>
63 #include <unistd.h>
64 
65 #define	TIMEOUT	15
66 
67 static void	quit(int);
68 static void	bye(int);
69 static void	hi(int);
70 static void	usage(void);
71 
72 static struct timeval	timeout;
73 static struct timeval	zerotime;
74 static struct termios	tty, ntty;
75 static long		nexttime;			/* keep the timeout time */
76 static int     		no_timeout;                     /* lock terminal forever */
77 static int		vtyunlock;			/* Unlock flag and code. */
78 
79 /*ARGSUSED*/
80 int
81 main(int argc, char **argv)
82 {
83 	struct passwd *pw;
84 	time_t timval;
85 	struct itimerval ntimer, otimer;
86 	struct tm *timp;
87 	int ch, failures, sectimeout, usemine, vtylock;
88 	long tmp;
89 	char *ap, *ep, *mypw, *cryptpw, *ttynam, *tzn;
90 	char hostname[MAXHOSTNAMELEN + 1], s[BUFSIZ], s1[BUFSIZ];
91 
92 	openlog("lock", LOG_ODELAY, LOG_AUTH);
93 
94 	sectimeout = TIMEOUT;
95 	pw = NULL;
96 	mypw = NULL;
97 	usemine = 0;
98 	no_timeout = 0;
99 	vtylock = 0;
100 	while ((ch = getopt(argc, argv, "npt:v")) != -1)
101 		switch(ch) {
102 		case 't':
103 			tmp = strtol(optarg, &ep, 10);
104 			if (*ep != '\0' || tmp > INT_MAX || tmp < INT_MIN)
105 				errx(1, "illegal timeout value");
106 			sectimeout = (int)tmp;
107 			break;
108 		case 'p':
109 			usemine = 1;
110 			if (!(pw = getpwuid(getuid())))
111 				errx(1, "unknown uid %d", getuid());
112 			mypw = strdup(pw->pw_passwd);
113 			break;
114 		case 'n':
115 			no_timeout = 1;
116 			break;
117 		case 'v':
118 			vtylock = 1;
119 			break;
120 		case '?':
121 		default:
122 			usage();
123 		}
124 	timeout.tv_sec = sectimeout * 60;
125 
126 	if (setuid(getuid()) != 0)			/* discard privs */
127 		errx(1, "setuid failed");
128 
129 	if (tcgetattr(STDIN_FILENO, &tty))		/* get information for header */
130 		err(1, "tcgetattr failed");
131 
132 	gethostname(hostname, sizeof(hostname));
133 	if (!(ttynam = ttyname(STDIN_FILENO)))
134 		errx(1, "not a terminal?");
135 	timval = time(NULL);
136 	nexttime = timval + (sectimeout * 60);
137 	timp = localtime(&timval);
138 	ap = asctime(timp);
139 	tzn = timp->tm_zone;
140 
141 	signal(SIGINT, quit);
142 	signal(SIGQUIT, quit);
143 	ntty = tty; ntty.c_lflag &= ~ECHO;
144 	tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &ntty);
145 
146 	if (!mypw) {
147 		/* get key and check again */
148 		printf("Key: ");
149 		if (!fgets(s, sizeof(s), stdin) || *s == '\n')
150 			quit(0);
151 		printf("\nAgain: ");
152 		/*
153 		 * Don't need EOF test here, if we get EOF, then s1 != s
154 		 * and the right things will happen.
155 		 */
156 		fgets(s1, sizeof(s1), stdin);
157 		putchar('\n');
158 		if (strcmp(s1, s)) {
159 			printf("\07lock: passwords didn't match.\n");
160 			tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
161 			exit(1);
162 		}
163 		s[0] = '\0';
164 		mypw = s1;
165 	}
166 
167 	/* set signal handlers */
168 	signal(SIGINT, hi);
169 	signal(SIGQUIT, hi);
170 	signal(SIGTSTP, hi);
171 	signal(SIGALRM, bye);
172 
173 	ntimer.it_interval = zerotime;
174 	ntimer.it_value = timeout;
175 	if (!no_timeout)
176 		setitimer(ITIMER_REAL, &ntimer, &otimer);
177 	if (vtylock) {
178 		/*
179 		 * If this failed, we want to err out; warn isn't good
180 		 * enough, since we don't want the user to think that
181 		 * everything is nice and locked because they got a
182 		 * "Key:" prompt.
183 		 */
184 		if (ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtylock) == -1) {
185 			tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
186 			err(1, "locking vty");
187 		}
188 		vtyunlock = 0x2;
189 	}
190 
191 	/* header info */
192 	if (pw != NULL)
193 		printf("lock: %s using %s on %s.", pw->pw_name,
194 		    ttynam, hostname);
195 	else
196 		printf("lock: %s on %s.", ttynam, hostname);
197 	if (no_timeout)
198 		printf(" no timeout.");
199 	else
200 		printf(" timeout in %d minute%s.", sectimeout,
201 		    sectimeout != 1 ? "s" : "");
202 	if (vtylock)
203 		printf(" vty locked.");
204 	printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
205 
206 	failures = 0;
207 
208 	for (;;) {
209 		printf("Key: ");
210 		if (!fgets(s, sizeof(s), stdin)) {
211 			clearerr(stdin);
212 			hi(0);
213 			goto tryagain;
214 		}
215 		if (usemine) {
216 			s[strlen(s) - 1] = '\0';
217 			cryptpw = crypt(s, mypw);
218 			if (cryptpw == NULL || !strcmp(mypw, cryptpw))
219 				break;
220 		}
221 		else if (!strcmp(s, s1))
222 			break;
223 		printf("\07\n");
224 	    	failures++;
225 		if (getuid() == 0)
226 	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
227 			failures, failures > 1 ? "S": "", ttynam, hostname);
228 tryagain:
229 		if (tcgetattr(0, &ntty) && (errno != EINTR))
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 	fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
245 	exit(1);
246 }
247 
248 static void
249 hi(int signo __unused)
250 {
251 	time_t timval;
252 
253 	if ((timval = time(NULL)) != (time_t)-1) {
254 		printf("lock: type in the unlock key. ");
255 		if (no_timeout) {
256 			putchar('\n');
257 		} else {
258 			printf("timeout in %jd:%jd minutes\n",
259 			    (intmax_t)(nexttime - timval) / 60,
260 			    (intmax_t)(nexttime - timval) % 60);
261 		}
262 	}
263 }
264 
265 static void
266 quit(int signo __unused)
267 {
268 	putchar('\n');
269 	tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
270 	if (vtyunlock)
271 		ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
272 	exit(0);
273 }
274 
275 static void
276 bye(int signo __unused)
277 {
278 	if (!no_timeout) {
279 		tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
280 		if (vtyunlock)
281 			ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
282 		printf("lock: timeout\n");
283 		exit(1);
284 	}
285 }
286