usr.bin/lock/lock.c

   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  * $DragonFly: src/usr.bin/lock/lock.c,v 1.5 2007/11/25 18:10:07 swildner Exp $
  40  */
  41
  42 /*
  43  * Lock a terminal up until the given key is entered or the given
  44  * interval times out.
  45  *
  46  * Timeout interval is by default TIMEOUT, it can be changed with
  47  * an argument of the form -time where time is in minutes
  48  */
  49
  50 #include <sys/param.h>
  51 #include <sys/time.h>
  52 #include <sys/consio.h>
  53
  54 #include <err.h>
  55 #include <pwd.h>
  56 #include <sgtty.h>
  57 #include <signal.h>
  58 #include <stdio.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include <syslog.h>
  62 #include <unistd.h>
  63
  64 #define TIMEOUT 15
  65
  66 static void     quit(int);
  67 static void     bye(int);
  68 static void     hi(int);
  69 static void     usage(void);
  70
  71 struct timeval  timeout;
  72 struct timeval  zerotime;
  73 struct sgttyb   tty, ntty;
  74 long    nexttime;                       /* keep the timeout time */
  75 int     no_timeout;                     /* lock terminal forever */
  76 int     vtyunlock;                      /* Unlock flag and code. */
  77
  78 /*ARGSUSED*/
  79 int
  80 main(int argc, char **argv)
  81 {
  82         struct passwd *pw;
  83         struct timeval timval;
  84         time_t timval_sec;
  85         struct itimerval ntimer, otimer;
  86         struct tm *timp;
  87         int ch, failures, sectimeout, usemine, vtylock;
  88         long tmp;
  89         char *ap, *ep, *mypw, *ttynam, *tzn;
  90         char hostname[MAXHOSTNAMELEN + 1], s[BUFSIZ], s1[BUFSIZ];
  91
  92         openlog("lock", LOG_ODELAY, LOG_AUTH);
  93
  94         sectimeout = TIMEOUT;
  95         mypw = NULL;
  96         usemine = 0;
  97         no_timeout = 0;
  98         vtylock = 0;
  99         while ((ch = getopt(argc, argv, "npt:v")) != -1)
 100                 switch(ch) {
 101                 case 't':
 102                         tmp = strtol(optarg, &ep, 10);
 103                         if (*ep != '\0' || tmp > INT_MAX || tmp < INT_MIN)
 104                                 errx(1, "illegal timeout value");
 105                         sectimeout = (int)tmp;
 106                         break;
 107                 case 'p':
 108                         usemine = 1;
 109                         if (!(pw = getpwuid(getuid())))
 110                                 errx(1, "unknown uid %d", getuid());
 111                         mypw = strdup(pw->pw_passwd);
 112                         break;
 113                 case 'n':
 114                         no_timeout = 1;
 115                         break;
 116                 case 'v':
 117                         vtylock = 1;
 118                         break;
 119                 case '?':
 120                 default:
 121                         usage();
 122                 }
 123         timeout.tv_sec = sectimeout * 60;
 124
 125         setuid(getuid());               /* discard privs */
 126
 127         if (ioctl(STDIN_FILENO, TIOCGETP, &tty))        /* get information for header */
 128                 err(1, "ioctl(TIOCGETP) failed");
 129
 130         gethostname(hostname, sizeof(hostname));
 131         if (!(ttynam = ttyname(0)))
 132                 errx(1, "not a terminal?");
 133         if (gettimeofday(&timval, NULL))
 134                 err(1, "gettimeofday");
 135         nexttime = timval.tv_sec + (sectimeout * 60);
 136         timval_sec = timval.tv_sec;
 137         timp = localtime(&timval_sec);
 138         ap = asctime(timp);
 139         tzn = timp->tm_zone;
 140
 141         signal(SIGINT, quit);
 142         signal(SIGQUIT, quit);
 143         ntty = tty; ntty.sg_flags &= ~ECHO;
 144         if (ioctl(STDIN_FILENO, TIOCSETP, &ntty))
 145                 err(1, "ioctl(TIOSETP) failed");
 146
 147         if (!mypw) {
 148                 /* get key and check again */
 149                 printf("Key: ");
 150                 if (!fgets(s, sizeof(s), stdin) || *s == '\n')
 151                         quit(0);
 152                 printf("\nAgain: ");
 153                 /*
 154                  * Don't need EOF test here, if we get EOF, then s1 != s
 155                  * and the right things will happen.
 156                  */
 157                 fgets(s1, sizeof(s1), stdin);
 158                 putchar('\n');
 159                 if (strcmp(s1, s)) {
 160                         printf("\07lock: passwords didn't match.\n");
 161                         ioctl(STDIN_FILENO, TIOCSETP, &tty);
 162                         exit(1);
 163                 }
 164                 s[0] = '\0';
 165                 mypw = s1;
 166         }
 167
 168         /* set signal handlers */
 169         signal(SIGINT, hi);
 170         signal(SIGQUIT, hi);
 171         signal(SIGTSTP, hi);
 172         signal(SIGALRM, bye);
 173
 174         ntimer.it_interval = zerotime;
 175         ntimer.it_value = timeout;
 176         if (!no_timeout)
 177                 setitimer(ITIMER_REAL, &ntimer, &otimer);
 178         if (vtylock) {
 179                 /*
 180                  * If this failed, we want to err out; warn isn't good
 181                  * enough, since we don't want the user to think that
 182                  * everything is nice and locked because they got a
 183                  * "Key:" prompt.
 184                  */
 185                 if (ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtylock) == -1) {
 186                         ioctl(STDIN_FILENO, TIOCSETP, &tty);
 187                         err(1, "locking vty");
 188                 }
 189                 vtyunlock = 0x2;
 190         }
 191
 192         /* header info */
 193         printf("lock: %s on %s.", ttynam, hostname);
 194         if (no_timeout)
 195                 printf(" no timeout.");
 196         else
 197                 printf(" timeout in %d minute%s.", sectimeout,
 198                     sectimeout != 1 ? "s" : "");
 199         if (vtylock)
 200                 printf(" vty locked.");
 201         printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
 202
 203         failures = 0;
 204
 205         for (;;) {
 206                 printf("Key: ");
 207                 if (!fgets(s, sizeof(s), stdin)) {
 208                         clearerr(stdin);
 209                         hi(0);
 210                         continue;
 211                 }
 212                 if (usemine) {
 213                         s[strlen(s) - 1] = '\0';
 214                         if (!strcmp(mypw, crypt(s, mypw)))
 215                                 break;
 216                 }
 217                 else if (!strcmp(s, s1))
 218                         break;
 219                 printf("\07\n");
 220                 failures++;
 221                 if (getuid() == 0)
 222                     syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
 223                         failures, failures > 1 ? "S": "", ttynam, hostname);
 224                 if (ioctl(STDIN_FILENO, TIOCGETP, &ntty))
 225                         exit(1);
 226                 sleep(1);               /* to discourage guessing */
 227         }
 228         if (getuid() == 0)
 229                 syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
 230                     hostname, ttynam);
 231         quit(0);
 232         return(0); /* not reached */
 233 }
 234
 235
 236 static void
 237 usage(void)
 238 {
 239         fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
 240         exit(1);
 241 }
 242
 243 static void
 244 hi(int signo __unused)
 245 {
 246         struct timeval timval;
 247
 248         if (!gettimeofday(&timval, NULL)) {
 249                 printf("lock: type in the unlock key. ");
 250                 if (no_timeout) {
 251                         putchar('\n');
 252                 } else {
 253                         printf("timeout in %ld:%ld minutes\n",
 254                             (nexttime - timval.tv_sec) / 60,
 255                             (nexttime - timval.tv_sec) % 60);
 256                 }
 257         }
 258 }
 259
 260 static void
 261 quit(int signo __unused)
 262 {
 263         putchar('\n');
 264         ioctl(STDIN_FILENO, TIOCSETP, &tty);
 265         if (vtyunlock)
 266                 ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
 267         exit(0);
 268 }
 269
 270 static void
 271 bye(int signo __unused)
 272 {
 273         if (!no_timeout) {
 274                 ioctl(STDIN_FILENO, TIOCSETP, &tty);
 275                 if (vtyunlock)
 276                         ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
 277                 printf("lock: timeout\n");
 278                 exit(1);
 279         }
 280 }