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. 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  * @(#) Copyright (c) 1980, 1987, 1993 The Regents of the University of California.  All rights reserved.
  33  * @(#)lock.c   8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/usr.bin/lock/lock.c,v 1.8.2.1 2002/09/15 22:32:56 dd Exp $
  35  */
  36
  37 /*
  38  * Lock a terminal up until the given key is entered or the given
  39  * interval times out.
  40  *
  41  * Timeout interval is by default TIMEOUT, it can be changed with
  42  * an argument of the form -time where time is in minutes
  43  */
  44
  45 #include <sys/param.h>
  46 #include <sys/time.h>
  47 #include <sys/consio.h>
  48
  49 #include <err.h>
  50 #include <pwd.h>
  51 #include <errno.h>
  52 #include <stdint.h>
  53 #include <signal.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <syslog.h>
  58 #include <termios.h>
  59 #include <unistd.h>
  60
  61 #define TIMEOUT 15
  62
  63 static void     quit(int);
  64 static void     bye(int);
  65 static void     hi(int);
  66 static void     usage(void);
  67
  68 static struct timeval   timeout;
  69 static struct timeval   zerotime;
  70 static struct termios   tty, ntty;
  71 static long             nexttime;                       /* keep the timeout time */
  72 static int              no_timeout;                     /* lock terminal forever */
  73 static int              vtyunlock;                      /* Unlock flag and code. */
  74
  75 /*ARGSUSED*/
  76 int
  77 main(int argc, char **argv)
  78 {
  79         struct passwd *pw;
  80         time_t timval;
  81         struct itimerval ntimer, otimer;
  82         struct tm *timp;
  83         int ch, failures, sectimeout, usemine, vtylock;
  84         long tmp;
  85         char *ap, *ep, *mypw, *cryptpw, *ttynam, *tzn;
  86         char hostname[MAXHOSTNAMELEN + 1], s[BUFSIZ], s1[BUFSIZ];
  87
  88         openlog("lock", LOG_ODELAY, LOG_AUTH);
  89
  90         sectimeout = TIMEOUT;
  91         pw = NULL;
  92         mypw = NULL;
  93         usemine = 0;
  94         no_timeout = 0;
  95         vtylock = 0;
  96         while ((ch = getopt(argc, argv, "npt:v")) != -1)
  97                 switch(ch) {
  98                 case 't':
  99                         tmp = strtol(optarg, &ep, 10);
 100                         if (*ep != '\0' || tmp > INT_MAX || tmp < INT_MIN)
 101                                 errx(1, "illegal timeout value");
 102                         sectimeout = (int)tmp;
 103                         break;
 104                 case 'p':
 105                         usemine = 1;
 106                         if (!(pw = getpwuid(getuid())))
 107                                 errx(1, "unknown uid %d", getuid());
 108                         mypw = strdup(pw->pw_passwd);
 109                         break;
 110                 case 'n':
 111                         no_timeout = 1;
 112                         break;
 113                 case 'v':
 114                         vtylock = 1;
 115                         break;
 116                 case '?':
 117                 default:
 118                         usage();
 119                 }
 120         timeout.tv_sec = sectimeout * 60;
 121
 122         if (setuid(getuid()) != 0)                      /* discard privs */
 123                 errx(1, "setuid failed");
 124
 125         if (tcgetattr(STDIN_FILENO, &tty))              /* get information for header */
 126                 err(1, "tcgetattr failed");
 127
 128         gethostname(hostname, sizeof(hostname));
 129         if (!(ttynam = ttyname(STDIN_FILENO)))
 130                 errx(1, "not a terminal?");
 131         timval = time(NULL);
 132         nexttime = timval + (sectimeout * 60);
 133         timp = localtime(&timval);
 134         ap = asctime(timp);
 135         tzn = timp->tm_zone;
 136
 137         signal(SIGINT, quit);
 138         signal(SIGQUIT, quit);
 139         ntty = tty; ntty.c_lflag &= ~ECHO;
 140         tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &ntty);
 141
 142         if (!mypw) {
 143                 /* get key and check again */
 144                 printf("Key: ");
 145                 if (!fgets(s, sizeof(s), stdin) || *s == '\n')
 146                         quit(0);
 147                 printf("\nAgain: ");
 148                 /*
 149                  * Don't need EOF test here, if we get EOF, then s1 != s
 150                  * and the right things will happen.
 151                  */
 152                 fgets(s1, sizeof(s1), stdin);
 153                 putchar('\n');
 154                 if (strcmp(s1, s)) {
 155                         printf("\07lock: passwords didn't match.\n");
 156                         tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
 157                         exit(1);
 158                 }
 159                 s[0] = '\0';
 160                 mypw = s1;
 161         }
 162
 163         /* set signal handlers */
 164         signal(SIGINT, hi);
 165         signal(SIGQUIT, hi);
 166         signal(SIGTSTP, hi);
 167         signal(SIGALRM, bye);
 168
 169         ntimer.it_interval = zerotime;
 170         ntimer.it_value = timeout;
 171         if (!no_timeout)
 172                 setitimer(ITIMER_REAL, &ntimer, &otimer);
 173         if (vtylock) {
 174                 /*
 175                  * If this failed, we want to err out; warn isn't good
 176                  * enough, since we don't want the user to think that
 177                  * everything is nice and locked because they got a
 178                  * "Key:" prompt.
 179                  */
 180                 if (ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtylock) == -1) {
 181                         tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
 182                         err(1, "locking vty");
 183                 }
 184                 vtyunlock = 0x2;
 185         }
 186
 187         /* header info */
 188         if (pw != NULL)
 189                 printf("lock: %s using %s on %s.", pw->pw_name,
 190                     ttynam, hostname);
 191         else
 192                 printf("lock: %s on %s.", ttynam, hostname);
 193         if (no_timeout)
 194                 printf(" no timeout.");
 195         else
 196                 printf(" timeout in %d minute%s.", sectimeout,
 197                     sectimeout != 1 ? "s" : "");
 198         if (vtylock)
 199                 printf(" vty locked.");
 200         printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
 201
 202         failures = 0;
 203
 204         for (;;) {
 205                 printf("Key: ");
 206                 if (!fgets(s, sizeof(s), stdin)) {
 207                         clearerr(stdin);
 208                         hi(0);
 209                         goto tryagain;
 210                 }
 211                 if (usemine) {
 212                         s[strlen(s) - 1] = '\0';
 213                         cryptpw = crypt(s, mypw);
 214                         if (cryptpw == NULL || !strcmp(mypw, cryptpw))
 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 tryagain:
 225                 if (tcgetattr(0, &ntty) && (errno != EINTR))
 226                         exit(1);
 227                 sleep(1);               /* to discourage guessing */
 228         }
 229         if (getuid() == 0)
 230                 syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
 231                     hostname, ttynam);
 232         quit(0);
 233         return(0); /* not reached */
 234 }
 235
 236
 237 static void
 238 usage(void)
 239 {
 240         fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
 241         exit(1);
 242 }
 243
 244 static void
 245 hi(int signo __unused)
 246 {
 247         time_t timval;
 248
 249         if ((timval = time(NULL)) != (time_t)-1) {
 250                 printf("lock: type in the unlock key. ");
 251                 if (no_timeout) {
 252                         putchar('\n');
 253                 } else {
 254                         printf("timeout in %jd:%jd minutes\n",
 255                             (intmax_t)(nexttime - timval) / 60,
 256                             (intmax_t)(nexttime - timval) % 60);
 257                 }
 258         }
 259 }
 260
 261 static void
 262 quit(int signo __unused)
 263 {
 264         putchar('\n');
 265         tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
 266         if (vtyunlock)
 267                 ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
 268         exit(0);
 269 }
 270
 271 static void
 272 bye(int signo __unused)
 273 {
 274         if (!no_timeout) {
 275                 tcsetattr(STDIN_FILENO, TCSADRAIN|TCSASOFT, &tty);
 276                 if (vtyunlock)
 277                         ioctl(STDIN_FILENO, VT_LOCKSWITCH, &vtyunlock);
 278                 printf("lock: timeout\n");
 279                 exit(1);
 280         }
 281 }