1 /*- 2 * Copyright (c) 1980, 1987, 1988, 1991 The Regents of the University 3 * of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 char copyright[] = 10 "@(#) Copyright (c) 1980, 1987, 1988, 1991 The Regents of the University of California.\n\ 11 All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)login.c 5.75 (Berkeley) 11/19/91"; 16 #endif /* not lint */ 17 18 /* 19 * login [ name ] 20 * login -h hostname (for telnetd, etc.) 21 * login -f name (for pre-authenticated login: datakit, xterm, etc.) 22 */ 23 24 #include <sys/param.h> 25 #include <sys/stat.h> 26 #include <sys/time.h> 27 #include <sys/resource.h> 28 #include <sys/file.h> 29 30 #include <utmp.h> 31 #include <signal.h> 32 #include <errno.h> 33 #include <ttyent.h> 34 #include <syslog.h> 35 #include <grp.h> 36 #include <pwd.h> 37 #include <setjmp.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <tzfile.h> 41 #include "pathnames.h" 42 43 #define TTYGRPNAME "tty" /* name of group to own ttys */ 44 45 /* 46 * This bounds the time given to login. Not a define so it can 47 * be patched on machines where it's too small. 48 */ 49 int timeout = 300; 50 int rootlogin; 51 #ifdef KERBEROS 52 int notickets = 1; 53 char *instance; 54 char *krbtkfile_env; 55 int authok; 56 #endif 57 58 struct passwd *pwd; 59 int failures; 60 char term[64], *envinit[1], *hostname, *username, *tty; 61 62 main(argc, argv) 63 int argc; 64 char **argv; 65 { 66 extern int optind; 67 extern char *optarg, **environ; 68 struct timeval tp; 69 struct group *gr; 70 register int ch; 71 register char *p; 72 int ask, fflag, hflag, pflag, cnt, uid; 73 int quietlog, rval; 74 char *domain, *salt, *ttyn; 75 char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10]; 76 char localhost[MAXHOSTNAMELEN]; 77 char *ctime(), *ttyname(), *stypeof(), *crypt(), *getpass(); 78 time_t time(); 79 off_t lseek(); 80 void timedout(); 81 82 (void)signal(SIGALRM, timedout); 83 (void)alarm((u_int)timeout); 84 (void)signal(SIGQUIT, SIG_IGN); 85 (void)signal(SIGINT, SIG_IGN); 86 (void)setpriority(PRIO_PROCESS, 0, 0); 87 88 openlog("login", LOG_ODELAY, LOG_AUTH); 89 90 /* 91 * -p is used by getty to tell login not to destroy the environment 92 * -f is used to skip a second login authentication 93 * -h is used by other servers to pass the name of the remote 94 * host to login so that it may be placed in utmp and wtmp 95 */ 96 domain = NULL; 97 if (gethostname(localhost, sizeof(localhost)) < 0) 98 syslog(LOG_ERR, "couldn't get local hostname: %m"); 99 else 100 domain = index(localhost, '.'); 101 102 fflag = hflag = pflag = 0; 103 uid = getuid(); 104 while ((ch = getopt(argc, argv, "fh:p")) != EOF) 105 switch (ch) { 106 case 'f': 107 fflag = 1; 108 break; 109 case 'h': 110 if (uid) { 111 (void)fprintf(stderr, 112 "login: -h option: %s\n", strerror(EPERM)); 113 exit(1); 114 } 115 hflag = 1; 116 if (domain && (p = index(optarg, '.')) && 117 strcasecmp(p, domain) == 0) 118 *p = 0; 119 hostname = optarg; 120 break; 121 case 'p': 122 pflag = 1; 123 break; 124 case '?': 125 default: 126 if (!uid) 127 syslog(LOG_ERR, "invalid flag %c", ch); 128 (void)fprintf(stderr, 129 "usage: login [-fp] [-h hostname] [username]\n"); 130 exit(1); 131 } 132 argc -= optind; 133 argv += optind; 134 if (*argv) { 135 username = *argv; 136 ask = 0; 137 } else 138 ask = 1; 139 140 for (cnt = getdtablesize(); cnt > 2; cnt--) 141 close(cnt); 142 143 ttyn = ttyname(0); 144 if (ttyn == NULL || *ttyn == '\0') { 145 (void)sprintf(tname, "%s??", _PATH_TTY); 146 ttyn = tname; 147 } 148 if (tty = rindex(ttyn, '/')) 149 ++tty; 150 else 151 tty = ttyn; 152 153 for (cnt = 0;; ask = 1) { 154 if (ask) { 155 fflag = 0; 156 getloginname(); 157 } 158 #ifdef KERBEROS 159 if ((instance = index(username, '.')) != NULL) { 160 if (strncmp(instance, ".root", 5) == 0) 161 rootlogin++; 162 *instance++ = '\0'; 163 } else { 164 rootlogin = 0; 165 instance = ""; 166 } 167 #endif 168 if (strlen(username) > UT_NAMESIZE) 169 username[UT_NAMESIZE] = '\0'; 170 171 /* 172 * Note if trying multiple user names; log failures for 173 * previous user name, but don't bother logging one failure 174 * for nonexistent name (mistyped username). 175 */ 176 if (failures && strcmp(tbuf, username)) { 177 if (failures > (pwd ? 0 : 1)) 178 badlogin(tbuf); 179 failures = 0; 180 } 181 (void)strcpy(tbuf, username); 182 183 if (pwd = getpwnam(username)) 184 salt = pwd->pw_passwd; 185 else 186 salt = "xx"; 187 188 /* 189 * if we have a valid account name, and it doesn't have a 190 * password, or the -f option was specified and the caller 191 * is root or the caller isn't changing their uid, don't 192 * authenticate. 193 */ 194 if (pwd && (*pwd->pw_passwd == '\0' || 195 fflag && (uid == 0 || uid == pwd->pw_uid))) 196 break; 197 fflag = 0; 198 if (pwd && pwd->pw_uid == 0) 199 rootlogin = 1; 200 else 201 rootlogin = 0; 202 203 (void)setpriority(PRIO_PROCESS, 0, -4); 204 205 p = getpass("Password:"); 206 207 if (pwd) { 208 #ifdef KERBEROS 209 rval = klogin(pwd, instance, localhost, p); 210 if (rval == 0) 211 authok = 1; 212 else if (rval == 1) { 213 if (pwd->pw_uid != 0) 214 rootlogin = 0; 215 rval = strcmp(crypt(p, salt), pwd->pw_passwd); 216 } 217 #else 218 rval = strcmp(crypt(p, salt), pwd->pw_passwd); 219 #endif 220 } 221 bzero(p, strlen(p)); 222 223 (void)setpriority(PRIO_PROCESS, 0, 0); 224 225 /* 226 * If trying to log in as root without Kerberos, 227 * but with insecure terminal, refuse the login attempt. 228 */ 229 #ifdef KERBEROS 230 if (authok == 0) 231 #endif 232 if (pwd && rootlogin && !rootterm(tty)) { 233 (void)fprintf(stderr, 234 "%s login refused on this terminal.\n", 235 pwd->pw_name); 236 if (hostname) 237 syslog(LOG_NOTICE, 238 "LOGIN %s REFUSED FROM %s ON TTY %s", 239 pwd->pw_name, hostname, tty); 240 else 241 syslog(LOG_NOTICE, 242 "LOGIN %s REFUSED ON TTY %s", 243 pwd->pw_name, tty); 244 continue; 245 } 246 247 if (pwd && !rval) 248 break; 249 250 (void)printf("Login incorrect\n"); 251 failures++; 252 /* we allow 10 tries, but after 3 we start backing off */ 253 if (++cnt > 3) { 254 if (cnt >= 10) { 255 badlogin(username); 256 sleepexit(1); 257 } 258 sleep((u_int)((cnt - 3) * 5)); 259 } 260 } 261 262 /* committed to login -- turn off timeout */ 263 (void)alarm((u_int)0); 264 265 endpwent(); 266 267 /* if user not super-user, check for disabled logins */ 268 if (!rootlogin) 269 checknologin(); 270 271 if (chdir(pwd->pw_dir) < 0) { 272 (void)printf("No home directory %s!\n", pwd->pw_dir); 273 if (chdir("/")) 274 exit(0); 275 pwd->pw_dir = "/"; 276 (void)printf("Logging in with home = \"/\".\n"); 277 } 278 279 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 280 281 if (pwd->pw_change || pwd->pw_expire) 282 (void)gettimeofday(&tp, (struct timezone *)NULL); 283 if (pwd->pw_change) 284 if (tp.tv_sec >= pwd->pw_change) { 285 (void)printf("Sorry -- your password has expired.\n"); 286 sleepexit(1); 287 } else if (pwd->pw_change - tp.tv_sec < 288 2 * DAYSPERWEEK * SECSPERDAY && !quietlog) 289 (void)printf("Warning: your password expires on %s", 290 ctime(&pwd->pw_change)); 291 if (pwd->pw_expire) 292 if (tp.tv_sec >= pwd->pw_expire) { 293 (void)printf("Sorry -- your account has expired.\n"); 294 sleepexit(1); 295 } else if (pwd->pw_expire - tp.tv_sec < 296 2 * DAYSPERWEEK * SECSPERDAY && !quietlog) 297 (void)printf("Warning: your account expires on %s", 298 ctime(&pwd->pw_expire)); 299 300 /* nothing else left to fail -- really log in */ 301 { 302 struct utmp utmp; 303 304 bzero((void *)&utmp, sizeof(utmp)); 305 (void)time(&utmp.ut_time); 306 strncpy(utmp.ut_name, username, sizeof(utmp.ut_name)); 307 if (hostname) 308 strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); 309 strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); 310 login(&utmp); 311 } 312 313 dolastlog(quietlog); 314 315 (void)chown(ttyn, pwd->pw_uid, 316 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid); 317 (void)setgid(pwd->pw_gid); 318 319 initgroups(username, pwd->pw_gid); 320 321 if (*pwd->pw_shell == '\0') 322 pwd->pw_shell = _PATH_BSHELL; 323 324 /* destroy environment unless user has requested preservation */ 325 if (!pflag) 326 environ = envinit; 327 (void)setenv("HOME", pwd->pw_dir, 1); 328 (void)setenv("SHELL", pwd->pw_shell, 1); 329 if (term[0] == '\0') 330 strncpy(term, stypeof(tty), sizeof(term)); 331 (void)setenv("TERM", term, 0); 332 (void)setenv("LOGNAME", pwd->pw_name, 1); 333 (void)setenv("USER", pwd->pw_name, 1); 334 (void)setenv("PATH", _PATH_DEFPATH, 0); 335 #ifdef KERBEROS 336 if (krbtkfile_env) 337 (void)setenv("KRBTKFILE", krbtkfile_env, 1); 338 #endif 339 340 if (tty[sizeof("tty")-1] == 'd') 341 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 342 /* if fflag is on, assume caller/authenticator has logged root login */ 343 if (rootlogin && fflag == 0) 344 if (hostname) 345 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 346 username, tty, hostname); 347 else 348 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", username, tty); 349 350 #ifdef KERBEROS 351 if (!quietlog && notickets == 1) 352 (void)printf("Warning: no Kerberos tickets issued.\n"); 353 #endif 354 355 if (!quietlog) { 356 struct stat st; 357 358 printf( 359 "Copyright (c) 1980,1983,1986,1988,1990,1991 The Regents of the University\n%s", 360 "of California. All rights reserved.\n\n"); 361 motd(); 362 (void)sprintf(tbuf, "%s/%s", _PATH_MAILDIR, pwd->pw_name); 363 if (stat(tbuf, &st) == 0 && st.st_size != 0) 364 (void)printf("You have %smail.\n", 365 (st.st_mtime > st.st_atime) ? "new " : ""); 366 } 367 368 (void)signal(SIGALRM, SIG_DFL); 369 (void)signal(SIGQUIT, SIG_DFL); 370 (void)signal(SIGINT, SIG_DFL); 371 (void)signal(SIGTSTP, SIG_IGN); 372 373 tbuf[0] = '-'; 374 strcpy(tbuf + 1, (p = rindex(pwd->pw_shell, '/')) ? 375 p + 1 : pwd->pw_shell); 376 377 if (setlogin(pwd->pw_name) < 0) 378 syslog(LOG_ERR, "setlogin() failure: %m"); 379 380 /* discard permissions last so can't get killed and drop core */ 381 if (rootlogin) 382 (void) setuid(0); 383 else 384 (void) setuid(pwd->pw_uid); 385 386 execlp(pwd->pw_shell, tbuf, 0); 387 (void)fprintf(stderr, "%s: %s\n", pwd->pw_shell, strerror(errno)); 388 exit(1); 389 } 390 391 #ifdef KERBEROS 392 #define NBUFSIZ (UT_NAMESIZE + 1 + 5) /* .root suffix */ 393 #else 394 #define NBUFSIZ (UT_NAMESIZE + 1) 395 #endif 396 397 getloginname() 398 { 399 register int ch; 400 register char *p; 401 static char nbuf[NBUFSIZ]; 402 403 for (;;) { 404 (void)printf("login: "); 405 for (p = nbuf; (ch = getchar()) != '\n'; ) { 406 if (ch == EOF) { 407 badlogin(username); 408 exit(0); 409 } 410 if (p < nbuf + (NBUFSIZ - 1)) 411 *p++ = ch; 412 } 413 if (p > nbuf) 414 if (nbuf[0] == '-') 415 (void)fprintf(stderr, 416 "login names may not start with '-'.\n"); 417 else { 418 *p = '\0'; 419 username = nbuf; 420 break; 421 } 422 } 423 } 424 425 void 426 timedout() 427 { 428 (void)fprintf(stderr, "Login timed out after %d seconds\n", timeout); 429 exit(0); 430 } 431 432 rootterm(ttyn) 433 char *ttyn; 434 { 435 struct ttyent *t; 436 437 return((t = getttynam(ttyn)) && t->ty_status&TTY_SECURE); 438 } 439 440 jmp_buf motdinterrupt; 441 442 motd() 443 { 444 register int fd, nchars; 445 sig_t oldint; 446 void sigint(); 447 char tbuf[8192]; 448 449 if ((fd = open(_PATH_MOTDFILE, O_RDONLY, 0)) < 0) 450 return; 451 oldint = signal(SIGINT, sigint); 452 if (setjmp(motdinterrupt) == 0) 453 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0) 454 (void)write(fileno(stdout), tbuf, nchars); 455 (void)signal(SIGINT, oldint); 456 (void)close(fd); 457 } 458 459 void 460 sigint() 461 { 462 longjmp(motdinterrupt, 1); 463 } 464 465 checknologin() 466 { 467 register int fd, nchars; 468 char tbuf[8192]; 469 470 if ((fd = open(_PATH_NOLOGIN, O_RDONLY, 0)) >= 0) { 471 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0) 472 (void)write(fileno(stdout), tbuf, nchars); 473 sleepexit(0); 474 } 475 } 476 477 dolastlog(quiet) 478 int quiet; 479 { 480 struct lastlog ll; 481 int fd; 482 char *ctime(); 483 484 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 485 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 486 if (!quiet) { 487 if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && 488 ll.ll_time != 0) { 489 (void)printf("Last login: %.*s ", 490 24-5, (char *)ctime(&ll.ll_time)); 491 if (*ll.ll_host != '\0') 492 (void)printf("from %.*s\n", 493 sizeof(ll.ll_host), ll.ll_host); 494 else 495 (void)printf("on %.*s\n", 496 sizeof(ll.ll_line), ll.ll_line); 497 } 498 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 499 } 500 bzero((void *)&ll, sizeof(ll)); 501 (void)time(&ll.ll_time); 502 strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 503 if (hostname) 504 strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); 505 (void)write(fd, (char *)&ll, sizeof(ll)); 506 (void)close(fd); 507 } 508 } 509 510 badlogin(name) 511 char *name; 512 { 513 if (failures == 0) 514 return; 515 if (hostname) { 516 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 517 failures, failures > 1 ? "S" : "", hostname); 518 syslog(LOG_AUTHPRIV|LOG_NOTICE, 519 "%d LOGIN FAILURE%s FROM %s, %s", 520 failures, failures > 1 ? "S" : "", hostname, name); 521 } else { 522 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 523 failures, failures > 1 ? "S" : "", tty); 524 syslog(LOG_AUTHPRIV|LOG_NOTICE, 525 "%d LOGIN FAILURE%s ON %s, %s", 526 failures, failures > 1 ? "S" : "", tty, name); 527 } 528 } 529 530 #undef UNKNOWN 531 #define UNKNOWN "su" 532 533 char * 534 stypeof(ttyid) 535 char *ttyid; 536 { 537 struct ttyent *t; 538 539 return(ttyid && (t = getttynam(ttyid)) ? t->ty_type : UNKNOWN); 540 } 541 542 sleepexit(eval) 543 int eval; 544 { 545 sleep((u_int)5); 546 exit(eval); 547 } 548