usr.bin/login/login_pam.c

   1 /*     $NetBSD: login_pam.c,v 1.24 2014/11/12 22:23:38 aymeric Exp $       */
   2
   3 /*-
   4  * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)login.c     8.4 (Berkeley) 4/2/94";
  41 #endif
  42 __RCSID("$NetBSD: login_pam.c,v 1.24 2014/11/12 22:23:38 aymeric Exp $");
  43 #endif /* not lint */
  44
  45 /*
  46  * login [ name ]
  47  * login -h hostname    (for telnetd, etc.)
  48  * login -f name        (for pre-authenticated login: datakit, xterm, etc.)
  49  */
  50
  51 #include <sys/param.h>
  52 #include <sys/stat.h>
  53 #include <sys/time.h>
  54 #include <sys/resource.h>
  55 #include <sys/file.h>
  56 #include <sys/wait.h>
  57 #include <sys/socket.h>
  58
  59 #include <err.h>
  60 #include <errno.h>
  61 #include <grp.h>
  62 #include <pwd.h>
  63 #include <setjmp.h>
  64 #include <signal.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <syslog.h>
  69 #include <time.h>
  70 #include <ttyent.h>
  71 #include <tzfile.h>
  72 #include <unistd.h>
  73 #include <util.h>
  74 #include <login_cap.h>
  75 #include <vis.h>
  76
  77 #include <security/pam_appl.h>
  78 #include <security/openpam.h>
  79
  80 #include "pathnames.h"
  81 #include "common.h"
  82
  83 #if 0
  84 static int       rootterm(char *);
  85 #endif
  86 static void      usage(void) __attribute__((__noreturn__));
  87
  88 static struct pam_conv pamc = { openpam_ttyconv, NULL };
  89
  90 #define TTYGRPNAME      "tty"           /* name of group to own ttys */
  91
  92 #define DEFAULT_BACKOFF 3
  93 #define DEFAULT_RETRIES 10
  94
  95 static struct   passwd pwres;
  96 static char     pwbuf[1024];
  97 static struct   group grs, *grp;
  98 static char     grbuf[1024];
  99 extern char **environ;
 100
 101 int
 102 main(int argc, char *argv[])
 103 {
 104         struct stat st;
 105         int ask, ch, cnt, fflag, pflag, quietlog, rootlogin;
 106         int auth_passed;
 107         uid_t uid, saved_uid;
 108         gid_t saved_gid, saved_gids[NGROUPS_MAX];
 109         int nsaved_gids;
 110         char *domain, *p, *ttyn;
 111         char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
 112         char localhost[MAXHOSTNAMELEN + 1];
 113         int login_retries = DEFAULT_RETRIES,
 114             login_backoff = DEFAULT_BACKOFF;
 115         char *shell = NULL;
 116         login_cap_t *lc = NULL;
 117         pam_handle_t *pamh = NULL;
 118         int pam_err;
 119         sig_t oint, oabrt, oquit, oalrm;
 120         const void *newuser;
 121         int pam_silent = PAM_SILENT;
 122         pid_t xpid, pid;
 123         int status;
 124         char *saved_term;
 125         char **pamenv;
 126
 127         tbuf[0] = '\0';
 128         nested = NULL;
 129
 130         oabrt = signal(SIGABRT, SIG_IGN);
 131         oalrm = signal(SIGALRM, timedout);
 132         oint = signal(SIGINT, SIG_IGN);
 133         oquit = signal(SIGQUIT, SIG_IGN);
 134
 135         (void)alarm(timeout);
 136         (void)setpriority(PRIO_PROCESS, 0, 0);
 137
 138         openlog("login", 0, LOG_AUTH);
 139
 140         /*
 141          * -p is used by getty to tell login not to destroy the environment
 142          * -f is used to skip a second login authentication
 143          * -h is used by other servers to pass the name of the remote host to
 144          *    login so that it may be placed in utmp/utmpx and wtmp/wtmpx
 145          * -a in addition to -h, a server my supply -a to pass the actual
 146          *    server address.
 147          */
 148         domain = NULL;
 149         if (gethostname(localhost, sizeof(localhost)) < 0)
 150                 syslog(LOG_ERR, "couldn't get local hostname: %m");
 151         else
 152                 domain = strchr(localhost, '.');
 153         localhost[sizeof(localhost) - 1] = '\0';
 154
 155         fflag = pflag = 0;
 156         have_ss = 0;
 157         uid = getuid();
 158         while ((ch = getopt(argc, argv, "a:fh:p")) != -1)
 159                 switch (ch) {
 160                 case 'a':
 161                         if (uid) {
 162                                 errno = EPERM;
 163                                 err(EXIT_FAILURE, "-a option");
 164                         }
 165                         decode_ss(optarg);
 166                         break;
 167                 case 'f':
 168                         fflag = 1;
 169                         break;
 170                 case 'h':
 171                         if (uid) {
 172                                 errno = EPERM;
 173                                 err(EXIT_FAILURE, "-h option");
 174                         }
 175                         if (domain && (p = strchr(optarg, '.')) != NULL &&
 176                             strcasecmp(p, domain) == 0)
 177                                 *p = '\0';
 178                         hostname = optarg;
 179                         break;
 180                 case 'p':
 181                         pflag = 1;
 182                         break;
 183                 default:
 184                 case '?':
 185                         usage();
 186                         break;
 187                 }
 188
 189         setproctitle(NULL);
 190         argc -= optind;
 191         argv += optind;
 192
 193         if (*argv) {
 194                 username = trimloginname(*argv);
 195                 ask = 0;
 196         } else
 197                 ask = 1;
 198
 199 #ifdef F_CLOSEM
 200         (void)fcntl(3, F_CLOSEM, 0);
 201 #else
 202         for (cnt = getdtablesize(); cnt > 2; cnt--)
 203                 (void)close(cnt);
 204 #endif
 205
 206         ttyn = ttyname(STDIN_FILENO);
 207         if (ttyn == NULL || *ttyn == '\0') {
 208                 (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
 209                 ttyn = tname;
 210         }
 211         if ((tty = strstr(ttyn, "/pts/")) != NULL)
 212                 ++tty;
 213         else if ((tty = strrchr(ttyn, '/')) != NULL)
 214                 ++tty;
 215         else
 216                 tty = ttyn;
 217
 218         if (issetugid()) {
 219                 nested = strdup(user_from_uid(getuid(), 0));
 220                 if (nested == NULL) {
 221                         syslog(LOG_ERR, "strdup: %m");
 222                         sleepexit(EXIT_FAILURE);
 223                 }
 224         }
 225
 226         /* Get "login-retries" and "login-backoff" from default class */
 227         if ((lc = login_getclass(NULL)) != NULL) {
 228                 login_retries = (int)login_getcapnum(lc, "login-retries",
 229                     DEFAULT_RETRIES, DEFAULT_RETRIES);
 230                 login_backoff = (int)login_getcapnum(lc, "login-backoff",
 231                     DEFAULT_BACKOFF, DEFAULT_BACKOFF);
 232                 login_close(lc);
 233                 lc = NULL;
 234         }
 235
 236
 237         for (cnt = 0;; ask = 1) {
 238                 if (ask) {
 239                         fflag = 0;
 240                         username = trimloginname(getloginname());
 241                 }
 242                 rootlogin = 0;
 243                 auth_passed = 0;
 244
 245                 /*
 246                  * Note if trying multiple user names; log failures for
 247                  * previous user name, but don't bother logging one failure
 248                  * for nonexistent name (mistyped username).
 249                  */
 250                 if (failures && strcmp(tbuf, username)) {
 251                         if (failures > (pwd ? 0 : 1))
 252                                 badlogin(tbuf);
 253                         failures = 0;
 254                 }
 255
 256 #define PAM_END(msg) do {                                               \
 257         syslog(LOG_ERR, "%s: %s", msg, pam_strerror(pamh, pam_err));    \
 258         warnx("%s: %s", msg, pam_strerror(pamh, pam_err));              \
 259         pam_end(pamh, pam_err);                                         \
 260         sleepexit(EXIT_FAILURE);                                        \
 261 } while (/*CONSTCOND*/0)
 262
 263                 pam_err = pam_start("login", username, &pamc, &pamh);
 264                 if (pam_err != PAM_SUCCESS) {
 265                         if (pamh != NULL)
 266                                 PAM_END("pam_start");
 267                         /* Things went really bad... */
 268                         syslog(LOG_ERR, "pam_start failed: %s",
 269                             pam_strerror(pamh, pam_err));
 270                         errx(EXIT_FAILURE, "pam_start failed");
 271                 }
 272
 273 #define PAM_SET_ITEM(item, var) do {                                    \
 274         pam_err = pam_set_item(pamh, (item), (var));                    \
 275         if (pam_err != PAM_SUCCESS)                                     \
 276                 PAM_END("pam_set_item(" # item ")");                    \
 277 } while (/*CONSTCOND*/0)
 278
 279                 /*
 280                  * Fill hostname tty, and nested user
 281                  */
 282                 PAM_SET_ITEM(PAM_RHOST, hostname);
 283                 PAM_SET_ITEM(PAM_TTY, tty);
 284                 if (nested)
 285                         PAM_SET_ITEM(PAM_NUSER, nested);
 286                 if (have_ss)
 287                         PAM_SET_ITEM(PAM_SOCKADDR, &ss);
 288
 289                 /*
 290                  * Don't check for errors, because we don't want to give
 291                  * out any information.
 292                  */
 293                 pwd = NULL;
 294                 (void)getpwnam_r(username, &pwres, pwbuf, sizeof(pwbuf), &pwd);
 295
 296                 /*
 297                  * Establish the class now, before we might goto
 298                  * within the next block. pwd can be NULL since it
 299                  * falls back to the "default" class if it is.
 300                  */
 301                 lc = login_getclass(pwd ? pwd->pw_class : NULL);
 302
 303                 /*
 304                  * if we have a valid account name, and it doesn't have a
 305                  * password, or the -f option was specified and the caller
 306                  * is root or the caller isn't changing their uid, don't
 307                  * authenticate.
 308                  */
 309                 if (pwd) {
 310                         if (pwd->pw_uid == 0)
 311                                 rootlogin = 1;
 312
 313                         if (fflag && (uid == 0 || uid == pwd->pw_uid)) {
 314                                 /* already authenticated */
 315                                 auth_passed = 1;
 316                                 goto skip_auth;
 317                         }
 318                 }
 319
 320                 (void)setpriority(PRIO_PROCESS, 0, -4);
 321
 322                 switch(pam_err = pam_authenticate(pamh, pam_silent)) {
 323                 case PAM_SUCCESS:
 324                         /*
 325                          * PAM can change the user, refresh
 326                          * username, pwd, and lc.
 327                          */
 328                         pam_err = pam_get_item(pamh, PAM_USER, &newuser);
 329                         if (pam_err != PAM_SUCCESS)
 330                                 PAM_END("pam_get_item(PAM_USER)");
 331
 332                         username = newuser;
 333                         /*
 334                          * Don't check for errors, because we don't want to give
 335                          * out any information.
 336                          */
 337                         pwd = NULL;
 338                         (void)getpwnam_r(username, &pwres, pwbuf, sizeof(pwbuf),
 339                             &pwd);
 340                         lc = login_getpwclass(pwd);
 341                         auth_passed = 1;
 342
 343                         switch (pam_err = pam_acct_mgmt(pamh, pam_silent)) {
 344                         case PAM_SUCCESS:
 345                                 break;
 346
 347                         case PAM_NEW_AUTHTOK_REQD:
 348                                 pam_err = pam_chauthtok(pamh,
 349                                     pam_silent|PAM_CHANGE_EXPIRED_AUTHTOK);
 350
 351                                 if (pam_err != PAM_SUCCESS)
 352                                         PAM_END("pam_chauthtok");
 353                                 break;
 354
 355                         case PAM_AUTH_ERR:
 356                         case PAM_USER_UNKNOWN:
 357                         case PAM_MAXTRIES:
 358                                 auth_passed = 0;
 359                                 break;
 360
 361                         default:
 362                                 PAM_END("pam_acct_mgmt");
 363                                 break;
 364                         }
 365                         break;
 366
 367                 case PAM_AUTH_ERR:
 368                 case PAM_USER_UNKNOWN:
 369                 case PAM_MAXTRIES:
 370                         auth_passed = 0;
 371                         break;
 372
 373                 default:
 374                         PAM_END("pam_authenticate");
 375                         break;
 376                 }
 377
 378                 (void)setpriority(PRIO_PROCESS, 0, 0);
 379
 380 skip_auth:
 381                 /*
 382                  * If the user exists and authentication passed,
 383                  * get out of the loop and login the user.
 384                  */
 385                 if (pwd && auth_passed)
 386                         break;
 387
 388                 (void)printf("Login incorrect or refused on this terminal.\n");
 389                 failures++;
 390                 cnt++;
 391                 /*
 392                  * We allow login_retries tries, but after login_backoff
 393                  * we start backing off.  These default to 10 and 3
 394                  * respectively.
 395                  */
 396                 if (cnt > login_backoff) {
 397                         if (cnt >= login_retries) {
 398                                 badlogin(username);
 399                                 pam_end(pamh, PAM_SUCCESS);
 400                                 sleepexit(EXIT_FAILURE);
 401                         }
 402                         sleep((u_int)((cnt - login_backoff) * 5));
 403                 }
 404         }
 405
 406         /* committed to login -- turn off timeout */
 407         (void)alarm((u_int)0);
 408
 409         endpwent();
 410
 411         quietlog = login_getcapbool(lc, "hushlogin", 0);
 412
 413         /*
 414          * Temporarily give up special privileges so we can change
 415          * into NFS-mounted homes that are exported for non-root
 416          * access and have mode 7x0
 417          */
 418         saved_uid = geteuid();
 419         saved_gid = getegid();
 420         nsaved_gids = getgroups(NGROUPS_MAX, saved_gids);
 421
 422         (void)setegid(pwd->pw_gid);
 423         initgroups(username, pwd->pw_gid);
 424         (void)seteuid(pwd->pw_uid);
 425
 426         if (chdir(pwd->pw_dir) != 0) {
 427                 if (login_getcapbool(lc, "requirehome", 0)) {
 428                         (void)printf("Home directory %s required\n",
 429                             pwd->pw_dir);
 430                         pam_end(pamh, PAM_SUCCESS);
 431                         exit(EXIT_FAILURE);
 432                 }
 433
 434                 (void)printf("No home directory %s!\n", pwd->pw_dir);
 435                 if (chdir("/") == -1) {
 436                         pam_end(pamh, PAM_SUCCESS);
 437                         exit(EXIT_FAILURE);
 438                 }
 439                 pwd->pw_dir = __UNCONST("/");
 440                 (void)printf("Logging in with home = \"/\".\n");
 441         }
 442
 443         if (!quietlog) {
 444                 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
 445                 pam_silent = quietlog ? PAM_SILENT : 0;
 446         }
 447
 448         /* regain special privileges */
 449         setegid(saved_gid);
 450         setgroups(nsaved_gids, saved_gids);
 451         seteuid(saved_uid);
 452
 453         (void)getgrnam_r(TTYGRPNAME, &grs, grbuf, sizeof(grbuf), &grp);
 454         (void)chown(ttyn, pwd->pw_uid,
 455             (grp != NULL) ? grp->gr_gid : pwd->pw_gid);
 456
 457         if (ttyaction(ttyn, "login", pwd->pw_name))
 458                 (void)printf("Warning: ttyaction failed.\n");
 459
 460         /* Nothing else left to fail -- really log in. */
 461         update_db(quietlog, rootlogin, fflag);
 462
 463         if (nested == NULL && setusercontext(lc, pwd, pwd->pw_uid,
 464             LOGIN_SETLOGIN) != 0) {
 465                 syslog(LOG_ERR, "setusercontext failed");
 466                 pam_end(pamh, PAM_SUCCESS);
 467                 exit(EXIT_FAILURE);
 468         }
 469
 470         /*
 471          * Establish groups
 472          */
 473         if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
 474                 syslog(LOG_ERR, "setusercontext failed");
 475                 pam_end(pamh, PAM_SUCCESS);
 476                 exit(EXIT_FAILURE);
 477         }
 478
 479         pam_err = pam_setcred(pamh, pam_silent|PAM_ESTABLISH_CRED);
 480         if (pam_err != PAM_SUCCESS)
 481                 PAM_END("pam_setcred");
 482
 483         pam_err = pam_open_session(pamh, pam_silent);
 484         if (pam_err != PAM_SUCCESS)
 485                 PAM_END("pam_open_session");
 486
 487         /*
 488          * Fork because we need to call pam_closesession as root.
 489          * Make sure signals cannot kill the parent.
 490          * This has been handled in the begining of main.
 491          */
 492
 493         switch(pid = fork()) {
 494         case -1:
 495                 pam_err = pam_close_session(pamh, 0);
 496                 if (pam_err != PAM_SUCCESS) {
 497                         syslog(LOG_ERR, "pam_close_session: %s",
 498                             pam_strerror(pamh, pam_err));
 499                         warnx("pam_close_session: %s",
 500                             pam_strerror(pamh, pam_err));
 501                 }
 502                 syslog(LOG_ERR, "fork failed: %m");
 503                 warn("fork failed");
 504                 pam_end(pamh, pam_err);
 505                 exit(EXIT_FAILURE);
 506                 break;
 507
 508         case 0: /* Child */
 509                 break;
 510
 511         default:
 512                 /*
 513                  * Parent: wait for the child to terminate
 514                  * and call pam_close_session.
 515                  */
 516                 if ((xpid = waitpid(pid, &status, 0)) != pid) {
 517                         pam_err = pam_close_session(pamh, 0);
 518                         if (pam_err != PAM_SUCCESS) {
 519                                 syslog(LOG_ERR,
 520                                     "pam_close_session: %s",
 521                                     pam_strerror(pamh, pam_err));
 522                                 warnx("pam_close_session: %s",
 523                                     pam_strerror(pamh, pam_err));
 524                         }
 525                         pam_end(pamh, pam_err);
 526                         if (xpid != -1)
 527                                 warnx("wrong PID: %d != %d", pid, xpid);
 528                         else
 529                                 warn("wait for pid %d failed", pid);
 530                         exit(EXIT_FAILURE);
 531                 }
 532
 533                 (void)signal(SIGABRT, oabrt);
 534                 (void)signal(SIGALRM, oalrm);
 535                 (void)signal(SIGINT, oint);
 536                 (void)signal(SIGQUIT, oquit);
 537                 if ((pam_err = pam_close_session(pamh, 0)) != PAM_SUCCESS) {
 538                         syslog(LOG_ERR, "pam_close_session: %s",
 539                             pam_strerror(pamh, pam_err));
 540                         warnx("pam_close_session: %s",
 541                             pam_strerror(pamh, pam_err));
 542                 }
 543                 pam_end(pamh, PAM_SUCCESS);
 544                 exit(EXIT_SUCCESS);
 545                 break;
 546         }
 547
 548         /*
 549          * The child: starting here, we don't have to care about
 550          * handling PAM issues if we exit, the parent will do the
 551          * job when we exit.
 552          *
 553          * Destroy environment unless user has requested its preservation.
 554          * Try to preserve TERM anyway.
 555          */
 556         saved_term = getenv("TERM");
 557         if (!pflag) {
 558                 environ = envinit;
 559                 if (saved_term)
 560                         setenv("TERM", saved_term, 0);
 561         }
 562
 563         if (*pwd->pw_shell == '\0')
 564                 pwd->pw_shell = __UNCONST(_PATH_BSHELL);
 565
 566         shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
 567         if (*shell == '\0')
 568                 shell = pwd->pw_shell;
 569
 570         if ((pwd->pw_shell = strdup(shell)) == NULL) {
 571                 syslog(LOG_ERR, "Cannot alloc mem");
 572                 exit(EXIT_FAILURE);
 573         }
 574
 575         (void)setenv("HOME", pwd->pw_dir, 1);
 576         (void)setenv("SHELL", pwd->pw_shell, 1);
 577         if (term[0] == '\0') {
 578                 const char *tt = stypeof(tty);
 579
 580                 if (tt == NULL)
 581                         tt = login_getcapstr(lc, "term", NULL, NULL);
 582
 583                 /* unknown term -> "su" */
 584                 (void)strlcpy(term, tt != NULL ? tt : "su", sizeof(term));
 585         }
 586         (void)setenv("TERM", term, 0);
 587         (void)setenv("LOGNAME", pwd->pw_name, 1);
 588         (void)setenv("USER", pwd->pw_name, 1);
 589
 590         /*
 591          * Add PAM environement
 592          */
 593         if ((pamenv = pam_getenvlist(pamh)) != NULL) {
 594                 char **envitem;
 595
 596                 for (envitem = pamenv; *envitem; envitem++) {
 597                         putenv(*envitem);
 598                         free(*envitem);
 599                 }
 600
 601                 free(pamenv);
 602         }
 603
 604         /* This drops root privs */
 605         if (setusercontext(lc, pwd, pwd->pw_uid,
 606             (LOGIN_SETALL & ~LOGIN_SETLOGIN)) != 0) {
 607                 syslog(LOG_ERR, "setusercontext failed");
 608                 exit(EXIT_FAILURE);
 609         }
 610
 611         if (!quietlog) {
 612                 const char *fname;
 613
 614                 fname = login_getcapstr(lc, "copyright", NULL, NULL);
 615                 if (fname != NULL && access(fname, F_OK) == 0)
 616                         motd(fname);
 617                 else
 618                         (void)printf("%s", copyrightstr);
 619
 620                 fname = login_getcapstr(lc, "welcome", NULL, NULL);
 621                 if (fname == NULL || access(fname, F_OK) != 0)
 622                         fname = _PATH_MOTDFILE;
 623                 motd(fname);
 624
 625                 (void)snprintf(tbuf,
 626                     sizeof(tbuf), "%s/%s", _PATH_MAILDIR, pwd->pw_name);
 627                 if (stat(tbuf, &st) == 0 && st.st_size != 0)
 628                         (void)printf("You have %smail.\n",
 629                             (st.st_mtime > st.st_atime) ? "new " : "");
 630         }
 631
 632         login_close(lc);
 633
 634
 635         tbuf[0] = '-';
 636         (void)strlcpy(tbuf + 1, (p = strrchr(pwd->pw_shell, '/')) ?
 637             p + 1 : pwd->pw_shell, sizeof(tbuf) - 1);
 638
 639         (void)signal(SIGABRT, oabrt);
 640         (void)signal(SIGALRM, oalrm);
 641         (void)signal(SIGINT, oint);
 642         (void)signal(SIGQUIT, oquit);
 643         (void)signal(SIGTSTP, SIG_IGN);
 644
 645         execlp(pwd->pw_shell, tbuf, NULL);
 646         err(EXIT_FAILURE, "%s", pwd->pw_shell);
 647 }
 648
 649 static void
 650 usage(void)
 651 {
 652         (void)fprintf(stderr,
 653             "Usage: %s [-fp] [-a address] [-h hostname] [username]\n",
 654             getprogname());
 655         exit(EXIT_FAILURE);
 656 }
 657
 658 #if 0
 659 static int
 660 rootterm(char *ttyn)
 661 {
 662         struct ttyent *t;
 663
 664         return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
 665 }
 666 #endif