appl/kx/kxd.c

   1 /*
   2  * Copyright (c) 1995 - 2003 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  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  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "kx.h"
  35
  36 RCSID("$Id$");
  37
  38 static pid_t wait_on_pid = -1;
  39 static int   done        = 0;
  40
  41 /*
  42  * Signal handler that justs waits for the children when they die.
  43  */
  44
  45 static RETSIGTYPE
  46 childhandler (int sig)
  47 {
  48      pid_t pid;
  49      int status;
  50
  51      do {
  52        pid = waitpid (-1, &status, WNOHANG|WUNTRACED);
  53        if (pid > 0 && pid == wait_on_pid)
  54            done = 1;
  55      } while(pid > 0);
  56      signal (SIGCHLD, childhandler);
  57      SIGRETURN(0);
  58 }
  59
  60 /*
  61  * Print the error message `format' and `...' on fd and die.
  62  */
  63
  64 void
  65 fatal (kx_context *kc, int fd, char *format, ...)
  66 {
  67     u_char msg[1024];
  68     u_char *p;
  69     va_list args;
  70     int len;
  71
  72     va_start(args, format);
  73     p = msg;
  74     *p++ = ERROR;
  75     vsnprintf ((char *)p + 4, sizeof(msg) - 5, format, args);
  76     syslog (LOG_ERR, "%s", (char *)p + 4);
  77     len = strlen ((char *)p + 4);
  78     p += kx_put_int (len, p, 4, 4);
  79     p += len;
  80     kx_write (kc, fd, msg, p - msg);
  81     va_end(args);
  82     exit (1);
  83 }
  84
  85 /*
  86  * Remove all sockets and cookie files.
  87  */
  88
  89 static void
  90 cleanup(int nsockets, struct x_socket *sockets)
  91 {
  92     int i;
  93
  94     if(xauthfile[0])
  95         unlink(xauthfile);
  96     for (i = 0; i < nsockets; ++i) {
  97         if (sockets[i].pathname != NULL) {
  98             unlink (sockets[i].pathname);
  99             free (sockets[i].pathname);
 100         }
 101     }
 102     free(sockets);
 103 }
 104
 105 /*
 106  * Prepare to receive a connection on `sock'.
 107  */
 108
 109 static int
 110 recv_conn (int sock, kx_context *kc,
 111            int *dispnr, int *nsockets, struct x_socket **sockets,
 112            int tcp_flag)
 113 {
 114      u_char msg[1024], *p;
 115      char user[256];
 116      socklen_t addrlen;
 117      struct passwd *passwd;
 118      char remotehost[MaxHostNameLen];
 119      char remoteaddr[INET6_ADDRSTRLEN];
 120      int ret = 1;
 121      int flags;
 122      int len;
 123      uint32_t tmp32;
 124
 125      memset(kc, 0, sizeof(*kc));
 126      *nsockets = 0;
 127      *sockets = NULL;
 128      *dispnr = 0;
 129
 130      addrlen = sizeof(kc->__ss_this);
 131      kc->thisaddr = (struct sockaddr*)&kc->__ss_this;
 132      if (getsockname (sock, kc->thisaddr, &addrlen) < 0) {
 133          syslog (LOG_ERR, "getsockname: %m");
 134          exit (1);
 135      }
 136      kc->thisaddr_len = addrlen;
 137      addrlen = sizeof(kc->__ss_that);
 138      kc->thataddr = (struct sockaddr*)&kc->__ss_that;
 139      if (getpeername (sock, kc->thataddr, &addrlen) < 0) {
 140          syslog (LOG_ERR, "getpeername: %m");
 141          exit (1);
 142      }
 143      kc->thataddr_len = addrlen;
 144
 145      getnameinfo_verified (kc->thataddr,
 146                            kc->thataddr_len,
 147                            remotehost, sizeof(remotehost),
 148                            NULL, 0, 0);
 149
 150      if (net_read (sock, msg, 4) != 4) {
 151          syslog (LOG_ERR, "read: %m");
 152          exit (1);
 153      }
 154
 155 #ifdef KRB5
 156      if (ret && recv_v5_auth (kc, sock, msg) == 0)
 157          ret = 0;
 158 #endif
 159      if (ret) {
 160          syslog (LOG_ERR, "unrecognized auth protocol: %x %x %x %x",
 161                  msg[0], msg[1], msg[2], msg[3]);
 162          exit (1);
 163      }
 164
 165      len = kx_read (kc, sock, msg, sizeof(msg));
 166      if (len < 0) {
 167          syslog (LOG_ERR, "kx_read failed");
 168          exit (1);
 169      }
 170      p = (u_char *)msg;
 171      if (*p != INIT)
 172          fatal(kc, sock, "Bad message");
 173      p++;
 174      if ((p - msg) < sizeof(msg))
 175          fatal(kc, sock, "user");
 176
 177      p += kx_get_int (p, &tmp32, 4, 0);
 178      if (tmp32 >= sizeof(user) - 1)
 179          fatal(kc, sock, "user name too long");
 180      if ((p - msg) + tmp32 >= sizeof(msg))
 181          fatal(kc, sock, "user too long");
 182      memcpy (user, p, tmp32);
 183      p += tmp32;
 184      user[tmp32] = '\0';
 185
 186      passwd = k_getpwnam (user);
 187      if (passwd == NULL)
 188          fatal (kc, sock, "cannot find uid for %s", user);
 189
 190      if (context_userok (kc, user) != 0)
 191          fatal (kc, sock, "%s not allowed to login as %s",
 192                 kc->user, user);
 193
 194      if ((p - msg) >= sizeof(msg))
 195          fatal(kc, sock, "user too long");
 196
 197      flags = *p++;
 198
 199      if (flags & PASSIVE) {
 200          pid_t pid;
 201          int tmp;
 202
 203          tmp = get_xsockets (nsockets, sockets, tcp_flag);
 204          if (tmp < 0) {
 205              fatal (kc, sock, "Cannot create X socket(s): %s",
 206                     strerror(errno));
 207          }
 208          *dispnr = tmp;
 209
 210          if (chown_xsockets (*nsockets, *sockets,
 211                             passwd->pw_uid, passwd->pw_gid)) {
 212              cleanup (*nsockets, *sockets);
 213              fatal (kc, sock, "Cannot chown sockets: %s",
 214                     strerror(errno));
 215          }
 216
 217          pid = fork();
 218          if (pid == -1) {
 219              cleanup (*nsockets, *sockets);
 220              fatal (kc, sock, "fork: %s", strerror(errno));
 221          } else if (pid != 0) {
 222              wait_on_pid = pid;
 223              while (!done)
 224                  pause ();
 225              cleanup (*nsockets, *sockets);
 226              exit (0);
 227          }
 228      }
 229
 230      if (setgid (passwd->pw_gid) ||
 231          initgroups(passwd->pw_name, passwd->pw_gid) ||
 232 #ifdef HAVE_GETUDBNAM /* XXX this happens on crays */
 233          setjob(passwd->pw_uid, 0) == -1 ||
 234 #endif
 235          setuid(passwd->pw_uid)) {
 236          syslog(LOG_ERR, "setting uid/groups: %m");
 237          fatal (kc, sock, "cannot set uid");
 238      }
 239
 240      ret = getnameinfo(kc->thataddr, kc->thataddr_len,
 241                        remoteaddr, sizeof(remoteaddr),
 242                        NULL, 0, NI_NUMERICHOST);
 243      if (ret != 0)
 244          fatal (kc, sock, "getnameinfo failed: %s", gai_strerror(ret));
 245
 246      syslog (LOG_INFO, "from %s(%s): %s -> %s",
 247              remotehost, remoteaddr,
 248              kc->user, user);
 249      umask(077);
 250      if (!(flags & PASSIVE)) {
 251          p += kx_get_int (p, &tmp32, 4, 0);
 252          if (tmp32 > display_size)
 253              fatal(kc, sock, "display too large");
 254          if ((p - msg) + tmp32 + 8 >= sizeof(msg))
 255              fatal(kc, sock, "user too long");
 256          memcpy (display, p, tmp32);
 257          display[tmp32] = '\0';
 258          p += tmp32;
 259          p += kx_get_int (p, &tmp32, 4, 0);
 260          len = min(tmp32, xauthfile_size);
 261          memcpy (xauthfile, p, len);
 262          xauthfile[len] = '\0';
 263      }
 264 #if defined(SO_KEEPALIVE) && defined(HAVE_SETSOCKOPT)
 265      if (flags & KEEP_ALIVE) {
 266          int one = 1;
 267
 268          setsockopt (sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&one,
 269                      sizeof(one));
 270      }
 271 #endif
 272      return flags;
 273 }
 274
 275 /*
 276  *
 277  */
 278
 279 static int
 280 passive_session (kx_context *kc, int fd, int sock, int cookiesp)
 281 {
 282     if (verify_and_remove_cookies (fd, sock, cookiesp))
 283         return 1;
 284     else
 285         return copy_encrypted (kc, fd, sock);
 286 }
 287
 288 /*
 289  *
 290  */
 291
 292 static int
 293 active_session (kx_context *kc, int fd, int sock, int cookiesp)
 294 {
 295     fd = connect_local_xsocket(0);
 296
 297     if (replace_cookie (fd, sock, xauthfile, cookiesp))
 298         return 1;
 299     else
 300         return copy_encrypted (kc, fd, sock);
 301 }
 302
 303 /*
 304  * Handle a new connection.
 305  */
 306
 307 static int
 308 doit_conn (kx_context *kc,
 309            int fd, int meta_sock, int flags, int cookiesp)
 310 {
 311     int sock, sock2, port;
 312     struct sockaddr_storage __ss_addr;
 313     struct sockaddr *addr = (struct sockaddr*)&__ss_addr;
 314     struct sockaddr_storage __ss_thisaddr;
 315     struct sockaddr *thisaddr = (struct sockaddr*)&__ss_thisaddr;
 316     socklen_t addrlen;
 317     u_char msg[1024], *p;
 318
 319     sock = socket (kc->thisaddr->sa_family, SOCK_STREAM, 0);
 320     if (sock < 0) {
 321         syslog (LOG_ERR, "socket: %m");
 322         return 1;
 323     }
 324 #if defined(TCP_NODELAY) && defined(HAVE_SETSOCKOPT)
 325     {
 326         int one = 1;
 327         setsockopt (sock, IPPROTO_TCP, TCP_NODELAY, (void *)&one, sizeof(one));
 328     }
 329 #endif
 330 #if defined(SO_KEEPALIVE) && defined(HAVE_SETSOCKOPT)
 331     if (flags & KEEP_ALIVE) {
 332         int one = 1;
 333
 334         setsockopt (sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&one,
 335                     sizeof(one));
 336     }
 337 #endif
 338     memset (&__ss_addr, 0, sizeof(__ss_addr));
 339     addr->sa_family = kc->thisaddr->sa_family;
 340     if (kc->thisaddr_len > sizeof(__ss_addr)) {
 341         syslog(LOG_ERR, "error in af");
 342         return 1;
 343     }
 344     if (bind (sock, addr, kc->thisaddr_len) < 0) {
 345         syslog (LOG_ERR, "bind: %m");
 346         return 1;
 347     }
 348     addrlen = sizeof(__ss_addr);
 349     if (getsockname (sock, addr, &addrlen) < 0) {
 350         syslog (LOG_ERR, "getsockname: %m");
 351         return 1;
 352     }
 353     if (listen (sock, SOMAXCONN) < 0) {
 354         syslog (LOG_ERR, "listen: %m");
 355         return 1;
 356     }
 357     port = socket_get_port(addr);
 358
 359     p = msg;
 360     *p++ = NEW_CONN;
 361     p += kx_put_int (ntohs(port), p, 4, 4);
 362
 363     if (kx_write (kc, meta_sock, msg, p - msg) < 0) {
 364         syslog (LOG_ERR, "write: %m");
 365         return 1;
 366     }
 367
 368     addrlen = sizeof(__ss_thisaddr);
 369     sock2 = accept (sock, thisaddr, &addrlen);
 370     if (sock2 < 0) {
 371         syslog (LOG_ERR, "accept: %m");
 372         return 1;
 373     }
 374     close (sock);
 375     close (meta_sock);
 376
 377     if (flags & PASSIVE)
 378         return passive_session (kc, fd, sock2, cookiesp);
 379     else
 380         return active_session (kc, fd, sock2, cookiesp);
 381 }
 382
 383 /*
 384  *  Is the current user the owner of the console?
 385  */
 386
 387 static void
 388 check_user_console (kx_context *kc, int fd)
 389 {
 390      struct stat sb;
 391
 392      if (stat ("/dev/console", &sb) < 0)
 393          fatal (kc, fd, "Cannot stat /dev/console: %s", strerror(errno));
 394      if (getuid() != sb.st_uid)
 395          fatal (kc, fd, "Permission denied");
 396 }
 397
 398 /* close down the new connection with a reasonable error message */
 399 static void
 400 close_connection(int fd, const char *message)
 401 {
 402     char buf[264]; /* max message */
 403     char *p;
 404     int lsb = 0;
 405     size_t mlen;
 406
 407     mlen = strlen(message);
 408     if(mlen > 255)
 409         mlen = 255;
 410
 411     /* read first part of connection packet, to get byte order */
 412     if(read(fd, buf, 6) != 6) {
 413         close(fd);
 414         return;
 415     }
 416     if(buf[0] == 0x6c)
 417         lsb++;
 418     p = buf;
 419     *p++ = 0;                           /* failed */
 420     *p++ = mlen;                        /* length of message */
 421     p += 4;                             /* skip protocol version */
 422     p += 2;                             /* skip additional length */
 423     memcpy(p, message, mlen);           /* copy message */
 424     p += mlen;
 425     while((p - buf) % 4)                /* pad to multiple of 4 bytes */
 426         *p++ = 0;
 427
 428     /* now fill in length of additional data */
 429     if(lsb) {
 430         buf[6] = (p - buf - 8) / 4;
 431         buf[7] = 0;
 432     }else{
 433         buf[6] = 0;
 434         buf[7] = (p - buf - 8) / 4;
 435     }
 436     write(fd, buf, p - buf);
 437     close(fd);
 438 }
 439
 440
 441 /*
 442  * Handle a passive session on `sock'
 443  */
 444
 445 static int
 446 doit_passive (kx_context *kc,
 447               int sock,
 448               int flags,
 449               int dispnr,
 450               int nsockets,
 451               struct x_socket *sockets,
 452               int tcp_flag)
 453 {
 454     int tmp;
 455     int len;
 456     size_t rem;
 457     u_char msg[1024], *p;
 458     int error;
 459
 460     display_num = dispnr;
 461     if (tcp_flag)
 462         snprintf (display, display_size, "localhost:%u", display_num);
 463     else
 464         snprintf (display, display_size, ":%u", display_num);
 465     error = create_and_write_cookie (xauthfile, xauthfile_size,
 466                                      cookie, cookie_len);
 467     if (error) {
 468         cleanup(nsockets, sockets);
 469         fatal (kc, sock, "Cookie-creation failed: %s", strerror(error));
 470         return 1;
 471     }
 472
 473     p = msg;
 474     rem = sizeof(msg);
 475     *p++ = ACK;
 476     --rem;
 477
 478     len = strlen (display);
 479     tmp = kx_put_int (len, p, rem, 4);
 480     if (tmp < 0 || rem < len + 4) {
 481         syslog (LOG_ERR, "doit: buffer too small");
 482         cleanup(nsockets, sockets);
 483         return 1;
 484     }
 485     p += tmp;
 486     rem -= tmp;
 487
 488     memcpy (p, display, len);
 489     p += len;
 490     rem -= len;
 491
 492     len = strlen (xauthfile);
 493     tmp = kx_put_int (len, p, rem, 4);
 494     if (tmp < 0 || rem < len + 4) {
 495         syslog (LOG_ERR, "doit: buffer too small");
 496         cleanup(nsockets, sockets);
 497         return 1;
 498     }
 499     p += tmp;
 500     rem -= tmp;
 501
 502     memcpy (p, xauthfile, len);
 503     p += len;
 504     rem -= len;
 505
 506     if(kx_write (kc, sock, msg, p - msg) < 0) {
 507         syslog (LOG_ERR, "write: %m");
 508         cleanup(nsockets, sockets);
 509         return 1;
 510     }
 511     for (;;) {
 512         pid_t child;
 513         int fd = -1;
 514         fd_set fds;
 515         int i;
 516         int ret;
 517         int cookiesp = TRUE;
 518
 519         FD_ZERO(&fds);
 520         if (sock >= FD_SETSIZE) {
 521             syslog (LOG_ERR, "fd too large");
 522             cleanup(nsockets, sockets);
 523             return 1;
 524         }
 525
 526         FD_SET(sock, &fds);
 527         for (i = 0; i < nsockets; ++i) {
 528             if (sockets[i].fd >= FD_SETSIZE) {
 529                 syslog (LOG_ERR, "fd too large");
 530                 cleanup(nsockets, sockets);
 531                 return 1;
 532             }
 533             FD_SET(sockets[i].fd, &fds);
 534         }
 535         ret = select(FD_SETSIZE, &fds, NULL, NULL, NULL);
 536         if(ret <= 0)
 537             continue;
 538         if(FD_ISSET(sock, &fds)){
 539             /* there are no processes left on the remote side
 540              */
 541             cleanup(nsockets, sockets);
 542             exit(0);
 543         } else if(ret) {
 544             for (i = 0; i < nsockets; ++i) {
 545                 if (FD_ISSET(sockets[i].fd, &fds)) {
 546                     if (sockets[i].flags == TCP) {
 547                         struct sockaddr_storage __ss_peer;
 548                         struct sockaddr *peer = (struct sockaddr*)&__ss_peer;
 549                         socklen_t slen = sizeof(__ss_peer);
 550
 551                         fd = accept (sockets[i].fd,
 552                                      peer,
 553                                      &slen);
 554                         if (fd < 0 && errno != EINTR)
 555                             syslog (LOG_ERR, "accept: %m");
 556
 557                         /* XXX */
 558                         if (fd >= 0 && suspicious_address (fd, peer)) {
 559                             close (fd);
 560                             fd = -1;
 561                             errno = EINTR;
 562                         }
 563                     } else if(sockets[i].flags == UNIX_SOCKET) {
 564                         socklen_t zero = 0;
 565
 566                         fd = accept (sockets[i].fd, NULL, &zero);
 567
 568                         if (fd < 0 && errno != EINTR)
 569                             syslog (LOG_ERR, "accept: %m");
 570 #ifdef MAY_HAVE_X11_PIPES
 571                     } else if(sockets[i].flags == STREAM_PIPE) {
 572                         /*
 573                          * this code tries to handle the
 574                          * send fd-over-pipe stuff for
 575                          * solaris
 576                          */
 577
 578                         struct strrecvfd strrecvfd;
 579
 580                         ret = ioctl (sockets[i].fd,
 581                                      I_RECVFD, &strrecvfd);
 582                         if (ret < 0 && errno != EINTR) {
 583                             syslog (LOG_ERR, "ioctl I_RECVFD: %m");
 584                         }
 585
 586                         /* XXX */
 587                         if (ret == 0) {
 588                             if (strrecvfd.uid != getuid()) {
 589                                 close (strrecvfd.fd);
 590                                 fd = -1;
 591                                 errno = EINTR;
 592                             } else {
 593                                 fd = strrecvfd.fd;
 594                                 cookiesp = FALSE;
 595                             }
 596                         }
 597 #endif /* MAY_HAVE_X11_PIPES */
 598                     } else
 599                         abort ();
 600                     break;
 601                 }
 602             }
 603         }
 604         if (fd < 0) {
 605             if (errno == EINTR)
 606                 continue;
 607             else
 608                 return 1;
 609         }
 610
 611         child = fork ();
 612         if (child < 0) {
 613             syslog (LOG_ERR, "fork: %m");
 614             if(errno != EAGAIN)
 615                 return 1;
 616             close_connection(fd, strerror(errno));
 617         } else if (child == 0) {
 618             for (i = 0; i < nsockets; ++i)
 619                 close (sockets[i].fd);
 620             return doit_conn (kc, fd, sock, flags, cookiesp);
 621         } else {
 622             close (fd);
 623         }
 624     }
 625 }
 626
 627 /*
 628  * Handle an active session on `sock'
 629  */
 630
 631 static int
 632 doit_active (kx_context *kc,
 633              int sock,
 634              int flags,
 635              int tcp_flag)
 636 {
 637     u_char msg[1024], *p;
 638
 639     check_user_console (kc, sock);
 640
 641     p = msg;
 642     *p++ = ACK;
 643
 644     if(kx_write (kc, sock, msg, p - msg) < 0) {
 645         syslog (LOG_ERR, "write: %m");
 646         return 1;
 647     }
 648     for (;;) {
 649         pid_t child;
 650         int len;
 651
 652         len = kx_read (kc, sock, msg, sizeof(msg));
 653         if (len < 0) {
 654             syslog (LOG_ERR, "read: %m");
 655             return 1;
 656         }
 657         p = (u_char *)msg;
 658         if (*p != NEW_CONN) {
 659             syslog (LOG_ERR, "bad_message: %d", *p);
 660             return 1;
 661         }
 662
 663         child = fork ();
 664         if (child < 0) {
 665             syslog (LOG_ERR, "fork: %m");
 666             if (errno != EAGAIN)
 667                 return 1;
 668         } else if (child == 0) {
 669             return doit_conn (kc, sock, sock, flags, 1);
 670         } else {
 671         }
 672     }
 673 }
 674
 675 /*
 676  * Receive a connection on `sock' and process it.
 677  */
 678
 679 static int
 680 doit(int sock, int tcp_flag)
 681 {
 682     int ret;
 683     kx_context context;
 684     int dispnr;
 685     int nsockets;
 686     struct x_socket *sockets;
 687     int flags;
 688
 689     flags = recv_conn (sock, &context, &dispnr, &nsockets, &sockets, tcp_flag);
 690
 691     if (flags & PASSIVE) {
 692         ret = doit_passive (&context, sock, flags, dispnr,
 693                             nsockets, sockets, tcp_flag);
 694     } else {
 695         ret = doit_active (&context, sock, flags, tcp_flag);
 696         cleanup(nsockets, sockets);
 697     }
 698     context_destroy (&context);
 699     return ret;
 700 }
 701
 702 static char *port_str           = NULL;
 703 static int inetd_flag           = 1;
 704 static int tcp_flag             = 0;
 705 static int version_flag         = 0;
 706 static int help_flag            = 0;
 707
 708 struct getargs args[] = {
 709     { "inetd",          'i',    arg_negative_flag,      &inetd_flag,
 710       "Not started from inetd" },
 711     { "tcp",            't',    arg_flag,       &tcp_flag,      "Use TCP" },
 712     { "port",           'p',    arg_string,     &port_str,      "Use this port",
 713       "port" },
 714     { "version",        0,      arg_flag,               &version_flag },
 715     { "help",           0,      arg_flag,               &help_flag }
 716 };
 717
 718 static void
 719 usage(int ret)
 720 {
 721     arg_printusage (args,
 722                     sizeof(args) / sizeof(args[0]),
 723                     NULL,
 724                     "host");
 725     exit (ret);
 726 }
 727
 728 /*
 729  * kxd - receive a forwarded X conncection
 730  */
 731
 732 int
 733 main (int argc, char **argv)
 734 {
 735     int port;
 736     int optidx = 0;
 737
 738     setprogname (argv[0]);
 739     roken_openlog ("kxd", LOG_ODELAY | LOG_PID, LOG_DAEMON);
 740
 741     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
 742                 &optidx))
 743         usage (1);
 744
 745     if (help_flag)
 746         usage (0);
 747
 748     if (version_flag) {
 749         print_version (NULL);
 750         return 0;
 751     }
 752
 753     if(port_str) {
 754         struct servent *s = roken_getservbyname (port_str, "tcp");
 755
 756         if (s)
 757             port = s->s_port;
 758         else {
 759             char *ptr;
 760
 761             port = strtol (port_str, &ptr, 10);
 762             if (port == 0 && ptr == port_str)
 763                 errx (1, "bad port `%s'", port_str);
 764             port = htons(port);
 765         }
 766     } else {
 767 #if defined(KRB5)
 768         port = krb5_getportbyname(NULL, "kx", "tcp", KX_PORT);
 769 #else
 770 #error define KRB5
 771 #endif
 772     }
 773
 774     if (!inetd_flag)
 775         mini_inetd (port);
 776
 777      signal (SIGCHLD, childhandler);
 778      return doit(STDIN_FILENO, tcp_flag);
 779 }