1 /*- 2 * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char copyright[] = 10 "@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\n\ 11 The Regents of the University of California. All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)login.c 8.2 (Berkeley) 02/24/94"; 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 <signal.h> 31 #include <ttyent.h> 32 #include <syslog.h> 33 #include <setjmp.h> 34 #include <tzfile.h> 35 #include <utmp.h> 36 #include <errno.h> 37 #include <grp.h> 38 #include <pwd.h> 39 #include <unistd.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include "pathnames.h" 44 45 void badlogin __P((char *)); 46 void checknologin __P((void)); 47 void dolastlog __P((int)); 48 void getloginname __P((void)); 49 void motd __P((void)); 50 int rootterm __P((char *)); 51 void sigint __P((int)); 52 void sleepexit __P((int)); 53 char *stypeof __P((char *)); 54 void timedout __P((int)); 55 #ifdef KERBEROS 56 int klogin __P((struct passwd *, char *, char *, char *)); 57 #endif 58 59 #define TTYGRPNAME "tty" /* name of group to own ttys */ 60 61 /* 62 * This bounds the time given to login. Not a define so it can 63 * be patched on machines where it's too small. 64 */ 65 int timeout = 300; 66 67 #ifdef KERBEROS 68 int notickets = 1; 69 char *instance; 70 char *krbtkfile_env; 71 int authok; 72 #endif 73 74 struct passwd *pwd; 75 int failures; 76 char term[64], *envinit[1], *hostname, *username, *tty; 77 78 int 79 main(argc, argv) 80 int argc; 81 char *argv[]; 82 { 83 extern char **environ; 84 register int ch; 85 register char *p; 86 struct group *gr; 87 struct stat st; 88 struct timeval tp; 89 struct utmp utmp; 90 int ask, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval, uid; 91 char *domain, *salt, *ttyn; 92 char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10]; 93 char localhost[MAXHOSTNAMELEN]; 94 95 (void)signal(SIGALRM, timedout); 96 (void)alarm((u_int)timeout); 97 (void)signal(SIGQUIT, SIG_IGN); 98 (void)signal(SIGINT, SIG_IGN); 99 (void)setpriority(PRIO_PROCESS, 0, 0); 100 101 openlog("login", LOG_ODELAY, LOG_AUTH); 102 103 /* 104 * -p is used by getty to tell login not to destroy the environment 105 * -f is used to skip a second login authentication 106 * -h is used by other servers to pass the name of the remote 107 * host to login so that it may be placed in utmp and wtmp 108 */ 109 domain = NULL; 110 if (gethostname(localhost, sizeof(localhost)) < 0) 111 syslog(LOG_ERR, "couldn't get local hostname: %m"); 112 else 113 domain = index(localhost, '.'); 114 115 fflag = hflag = pflag = 0; 116 uid = getuid(); 117 while ((ch = getopt(argc, argv, "fh:p")) != EOF) 118 switch (ch) { 119 case 'f': 120 fflag = 1; 121 break; 122 case 'h': 123 if (uid) { 124 (void)fprintf(stderr, 125 "login: -h option: %s\n", strerror(EPERM)); 126 exit(1); 127 } 128 hflag = 1; 129 if (domain && (p = index(optarg, '.')) && 130 strcasecmp(p, domain) == 0) 131 *p = 0; 132 hostname = optarg; 133 break; 134 case 'p': 135 pflag = 1; 136 break; 137 case '?': 138 default: 139 if (!uid) 140 syslog(LOG_ERR, "invalid flag %c", ch); 141 (void)fprintf(stderr, 142 "usage: login [-fp] [-h hostname] [username]\n"); 143 exit(1); 144 } 145 argc -= optind; 146 argv += optind; 147 148 if (*argv) { 149 username = *argv; 150 ask = 0; 151 } else 152 ask = 1; 153 154 for (cnt = getdtablesize(); cnt > 2; cnt--) 155 (void)close(cnt); 156 157 ttyn = ttyname(STDIN_FILENO); 158 if (ttyn == NULL || *ttyn == '\0') { 159 (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY); 160 ttyn = tname; 161 } 162 if (tty = rindex(ttyn, '/')) 163 ++tty; 164 else 165 tty = ttyn; 166 167 for (cnt = 0;; ask = 1) { 168 if (ask) { 169 fflag = 0; 170 getloginname(); 171 } 172 rootlogin = 0; 173 #ifdef KERBEROS 174 if ((instance = index(username, '.')) != NULL) { 175 if (strncmp(instance, ".root", 5) == 0) 176 rootlogin = 1; 177 *instance++ = '\0'; 178 } else 179 instance = ""; 180 #endif 181 if (strlen(username) > UT_NAMESIZE) 182 username[UT_NAMESIZE] = '\0'; 183 184 /* 185 * Note if trying multiple user names; log failures for 186 * previous user name, but don't bother logging one failure 187 * for nonexistent name (mistyped username). 188 */ 189 if (failures && strcmp(tbuf, username)) { 190 if (failures > (pwd ? 0 : 1)) 191 badlogin(tbuf); 192 failures = 0; 193 } 194 (void)strcpy(tbuf, username); 195 196 if (pwd = getpwnam(username)) 197 salt = pwd->pw_passwd; 198 else 199 salt = "xx"; 200 201 /* 202 * if we have a valid account name, and it doesn't have a 203 * password, or the -f option was specified and the caller 204 * is root or the caller isn't changing their uid, don't 205 * authenticate. 206 */ 207 if (pwd && (*pwd->pw_passwd == '\0' || 208 fflag && (uid == 0 || uid == pwd->pw_uid))) 209 break; 210 fflag = 0; 211 if (pwd && pwd->pw_uid == 0) 212 rootlogin = 1; 213 214 (void)setpriority(PRIO_PROCESS, 0, -4); 215 216 p = getpass("Password:"); 217 218 if (pwd) { 219 #ifdef KERBEROS 220 rval = klogin(pwd, instance, localhost, p); 221 if (rval == 0) 222 authok = 1; 223 else if (rval == 1) 224 rval = strcmp(crypt(p, salt), pwd->pw_passwd); 225 #else 226 rval = strcmp(crypt(p, salt), pwd->pw_passwd); 227 #endif 228 } 229 bzero(p, strlen(p)); 230 231 (void)setpriority(PRIO_PROCESS, 0, 0); 232 233 /* 234 * If trying to log in as root without Kerberos, 235 * but with insecure terminal, refuse the login attempt. 236 */ 237 #ifdef KERBEROS 238 if (authok == 0) 239 #endif 240 if (pwd && rootlogin && !rootterm(tty)) { 241 (void)fprintf(stderr, 242 "%s login refused on this terminal.\n", 243 pwd->pw_name); 244 if (hostname) 245 syslog(LOG_NOTICE, 246 "LOGIN %s REFUSED FROM %s ON TTY %s", 247 pwd->pw_name, hostname, tty); 248 else 249 syslog(LOG_NOTICE, 250 "LOGIN %s REFUSED ON TTY %s", 251 pwd->pw_name, tty); 252 continue; 253 } 254 255 if (pwd && !rval) 256 break; 257 258 (void)printf("Login incorrect\n"); 259 failures++; 260 /* we allow 10 tries, but after 3 we start backing off */ 261 if (++cnt > 3) { 262 if (cnt >= 10) { 263 badlogin(username); 264 sleepexit(1); 265 } 266 sleep((u_int)((cnt - 3) * 5)); 267 } 268 } 269 270 /* committed to login -- turn off timeout */ 271 (void)alarm((u_int)0); 272 273 endpwent(); 274 275 /* if user not super-user, check for disabled logins */ 276 if (!rootlogin) 277 checknologin(); 278 279 if (chdir(pwd->pw_dir) < 0) { 280 (void)printf("No home directory %s!\n", pwd->pw_dir); 281 if (chdir("/")) 282 exit(0); 283 pwd->pw_dir = "/"; 284 (void)printf("Logging in with home = \"/\".\n"); 285 } 286 287 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 288 289 if (pwd->pw_change || pwd->pw_expire) 290 (void)gettimeofday(&tp, (struct timezone *)NULL); 291 if (pwd->pw_change) 292 if (tp.tv_sec >= pwd->pw_change) { 293 (void)printf("Sorry -- your password has expired.\n"); 294 sleepexit(1); 295 } else if (pwd->pw_change - tp.tv_sec < 296 2 * DAYSPERWEEK * SECSPERDAY && !quietlog) 297 (void)printf("Warning: your password expires on %s", 298 ctime(&pwd->pw_change)); 299 if (pwd->pw_expire) 300 if (tp.tv_sec >= pwd->pw_expire) { 301 (void)printf("Sorry -- your account has expired.\n"); 302 sleepexit(1); 303 } else if (pwd->pw_expire - tp.tv_sec < 304 2 * DAYSPERWEEK * SECSPERDAY && !quietlog) 305 (void)printf("Warning: your account expires on %s", 306 ctime(&pwd->pw_expire)); 307 308 /* Nothing else left to fail -- really log in. */ 309 bzero((void *)&utmp, sizeof(utmp)); 310 (void)time(&utmp.ut_time); 311 (void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name)); 312 if (hostname) 313 (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); 314 (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); 315 login(&utmp); 316 317 dolastlog(quietlog); 318 319 (void)chown(ttyn, pwd->pw_uid, 320 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid); 321 (void)setgid(pwd->pw_gid); 322 323 initgroups(username, pwd->pw_gid); 324 325 if (*pwd->pw_shell == '\0') 326 pwd->pw_shell = _PATH_BSHELL; 327 328 /* Destroy environment unless user has requested its preservation. */ 329 if (!pflag) 330 environ = envinit; 331 (void)setenv("HOME", pwd->pw_dir, 1); 332 (void)setenv("SHELL", pwd->pw_shell, 1); 333 if (term[0] == '\0') 334 (void)strncpy(term, stypeof(tty), sizeof(term)); 335 (void)setenv("TERM", term, 0); 336 (void)setenv("LOGNAME", pwd->pw_name, 1); 337 (void)setenv("USER", pwd->pw_name, 1); 338 (void)setenv("PATH", _PATH_DEFPATH, 0); 339 #ifdef KERBEROS 340 if (krbtkfile_env) 341 (void)setenv("KRBTKFILE", krbtkfile_env, 1); 342 #endif 343 344 if (tty[sizeof("tty")-1] == 'd') 345 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 346 347 /* If fflag is on, assume caller/authenticator has logged root login. */ 348 if (rootlogin && fflag == 0) 349 if (hostname) 350 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 351 username, tty, hostname); 352 else 353 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", username, tty); 354 355 #ifdef KERBEROS 356 if (!quietlog && notickets == 1) 357 (void)printf("Warning: no Kerberos tickets issued.\n"); 358 #endif 359 360 if (!quietlog) { 361 (void)printf("%s\n\t%s %s\n\n", 362 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 363 "The Regents of the University of California. ", 364 "All rights reserved."); 365 motd(); 366 (void)snprintf(tbuf, 367 sizeof(tbuf), "%s/%s", _PATH_MAILDIR, pwd->pw_name); 368 if (stat(tbuf, &st) == 0 && st.st_size != 0) 369 (void)printf("You have %smail.\n", 370 (st.st_mtime > st.st_atime) ? "new " : ""); 371 } 372 373 (void)signal(SIGALRM, SIG_DFL); 374 (void)signal(SIGQUIT, SIG_DFL); 375 (void)signal(SIGINT, SIG_DFL); 376 (void)signal(SIGTSTP, SIG_IGN); 377 378 tbuf[0] = '-'; 379 (void)strcpy(tbuf + 1, (p = rindex(pwd->pw_shell, '/')) ? 380 p + 1 : pwd->pw_shell); 381 382 if (setlogin(pwd->pw_name) < 0) 383 syslog(LOG_ERR, "setlogin() failure: %m"); 384 385 /* Discard permissions last so can't get killed and drop core. */ 386 if (rootlogin) 387 (void) setuid(0); 388 else 389 (void) setuid(pwd->pw_uid); 390 391 execlp(pwd->pw_shell, tbuf, 0); 392 (void)fprintf(stderr, "%s: %s\n", pwd->pw_shell, strerror(errno)); 393 exit(1); 394 } 395 396 #ifdef KERBEROS 397 #define NBUFSIZ (UT_NAMESIZE + 1 + 5) /* .root suffix */ 398 #else 399 #define NBUFSIZ (UT_NAMESIZE + 1) 400 #endif 401 402 void 403 getloginname() 404 { 405 register int ch; 406 register char *p; 407 static char nbuf[NBUFSIZ]; 408 409 for (;;) { 410 (void)printf("login: "); 411 for (p = nbuf; (ch = getchar()) != '\n'; ) { 412 if (ch == EOF) { 413 badlogin(username); 414 exit(0); 415 } 416 if (p < nbuf + (NBUFSIZ - 1)) 417 *p++ = ch; 418 } 419 if (p > nbuf) 420 if (nbuf[0] == '-') 421 (void)fprintf(stderr, 422 "login names may not start with '-'.\n"); 423 else { 424 *p = '\0'; 425 username = nbuf; 426 break; 427 } 428 } 429 } 430 431 int 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 void 443 motd() 444 { 445 register int fd, nchars; 446 sig_t oldint; 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 /* ARGSUSED */ 460 void 461 sigint(signo) 462 int signo; 463 { 464 longjmp(motdinterrupt, 1); 465 } 466 467 /* ARGSUSED */ 468 void 469 timedout(signo) 470 int signo; 471 { 472 (void)fprintf(stderr, "Login timed out after %d seconds\n", timeout); 473 exit(0); 474 } 475 476 void 477 checknologin() 478 { 479 register int fd, nchars; 480 char tbuf[8192]; 481 482 if ((fd = open(_PATH_NOLOGIN, O_RDONLY, 0)) >= 0) { 483 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0) 484 (void)write(fileno(stdout), tbuf, nchars); 485 sleepexit(0); 486 } 487 } 488 489 void 490 dolastlog(quiet) 491 int quiet; 492 { 493 struct lastlog ll; 494 int fd; 495 496 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 497 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 498 if (!quiet) { 499 if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && 500 ll.ll_time != 0) { 501 (void)printf("Last login: %.*s ", 502 24-5, (char *)ctime(&ll.ll_time)); 503 if (*ll.ll_host != '\0') 504 (void)printf("from %.*s\n", 505 (int)sizeof(ll.ll_host), 506 ll.ll_host); 507 else 508 (void)printf("on %.*s\n", 509 (int)sizeof(ll.ll_line), 510 ll.ll_line); 511 } 512 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 513 } 514 bzero((void *)&ll, sizeof(ll)); 515 (void)time(&ll.ll_time); 516 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 517 if (hostname) 518 (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); 519 (void)write(fd, (char *)&ll, sizeof(ll)); 520 (void)close(fd); 521 } 522 } 523 524 void 525 badlogin(name) 526 char *name; 527 { 528 if (failures == 0) 529 return; 530 if (hostname) { 531 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 532 failures, failures > 1 ? "S" : "", hostname); 533 syslog(LOG_AUTHPRIV|LOG_NOTICE, 534 "%d LOGIN FAILURE%s FROM %s, %s", 535 failures, failures > 1 ? "S" : "", hostname, name); 536 } else { 537 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 538 failures, failures > 1 ? "S" : "", tty); 539 syslog(LOG_AUTHPRIV|LOG_NOTICE, 540 "%d LOGIN FAILURE%s ON %s, %s", 541 failures, failures > 1 ? "S" : "", tty, name); 542 } 543 } 544 545 #undef UNKNOWN 546 #define UNKNOWN "su" 547 548 char * 549 stypeof(ttyid) 550 char *ttyid; 551 { 552 struct ttyent *t; 553 554 return(ttyid && (t = getttynam(ttyid)) ? t->ty_type : UNKNOWN); 555 } 556 557 void 558 sleepexit(eval) 559 int eval; 560 { 561 (void)sleep((u_int)5); 562 exit(eval); 563 } 564