appl/kx/common.c

   1 /*
   2  * Copyright (c) 1995 - 2001 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 char x_socket[MaxPathLen];
  39
  40 uint32_t display_num;
  41 char display[MaxPathLen];
  42 int display_size = sizeof(display);
  43 char xauthfile[MaxPathLen];
  44 int xauthfile_size = sizeof(xauthfile);
  45 u_char cookie[16];
  46 size_t cookie_len = sizeof(cookie);
  47
  48 #ifndef X_UNIX_PATH
  49 #define X_UNIX_PATH "/tmp/.X11-unix/X"
  50 #endif
  51
  52 #ifndef X_PIPE_PATH
  53 #define X_PIPE_PATH "/tmp/.X11-pipe/X"
  54 #endif
  55
  56 /*
  57  * Allocate a unix domain socket in `s' for display `dpy' and with
  58  * filename `pattern'
  59  *
  60  * 0 if all is OK
  61  * -1 if bind failed badly
  62  * 1 if dpy is already used */
  63
  64 static int
  65 try_socket (struct x_socket *s, int dpy, const char *pattern)
  66 {
  67     struct sockaddr_un addr;
  68     int fd;
  69
  70     fd = socket (AF_UNIX, SOCK_STREAM, 0);
  71     if (fd < 0)
  72         err (1, "socket AF_UNIX");
  73     memset (&addr, 0, sizeof(addr));
  74     addr.sun_family = AF_UNIX;
  75     snprintf (addr.sun_path, sizeof(addr.sun_path), pattern, dpy);
  76     if(bind(fd,
  77             (struct sockaddr *)&addr,
  78             sizeof(addr)) < 0) {
  79         close (fd);
  80         if (errno == EADDRINUSE ||
  81             errno == EACCES  /* Cray return EACCESS */
  82 #ifdef ENOTUNIQ
  83             || errno == ENOTUNIQ /* bug in Solaris 2.4 */
  84 #endif
  85             )
  86             return 1;
  87         else
  88             return -1;
  89     }
  90     s->fd = fd;
  91     s->pathname = strdup (addr.sun_path);
  92     if (s->pathname == NULL)
  93         errx (1, "strdup: out of memory");
  94     s->flags = UNIX_SOCKET;
  95     return 0;
  96 }
  97
  98 #ifdef MAY_HAVE_X11_PIPES
  99 /*
 100  * Allocate a stream (masqueraded as a named pipe)
 101  *
 102  * 0 if all is OK
 103  * -1 if bind failed badly
 104  * 1 if dpy is already used
 105  */
 106
 107 static int
 108 try_pipe (struct x_socket *s, int dpy, const char *pattern)
 109 {
 110     char path[MAXPATHLEN];
 111     int ret;
 112     int fd;
 113     int pipefd[2];
 114
 115     snprintf (path, sizeof(path), pattern, dpy);
 116     fd = open (path, O_WRONLY | O_CREAT | O_EXCL, 0600);
 117     if (fd < 0) {
 118         if (errno == EEXIST)
 119             return 1;
 120         else
 121             return -1;
 122     }
 123
 124     close (fd);
 125
 126     ret = pipe (pipefd);
 127     if (ret < 0)
 128         err (1, "pipe");
 129
 130     ret = ioctl (pipefd[1], I_PUSH, "connld");
 131     if (ret < 0) {
 132         if(errno == ENOSYS)
 133             return -1;
 134         err (1, "ioctl I_PUSH");
 135     }
 136
 137     ret = fattach (pipefd[1], path);
 138     if (ret < 0)
 139         err (1, "fattach %s", path);
 140
 141     s->fd  = pipefd[0];
 142     close (pipefd[1]);
 143     s->pathname = strdup (path);
 144     if (s->pathname == NULL)
 145         errx (1, "strdup: out of memory");
 146     s->flags = STREAM_PIPE;
 147     return 0;
 148 }
 149 #endif /* MAY_HAVE_X11_PIPES */
 150
 151 /*
 152  * Try to create a TCP socket in `s' corresponding to display `dpy'.
 153  *
 154  * 0 if all is OK
 155  * -1 if bind failed badly
 156  * 1 if dpy is already used
 157  */
 158
 159 static int
 160 try_tcp (struct x_socket *s, int dpy)
 161 {
 162     struct sockaddr_in tcpaddr;
 163     struct in_addr local;
 164     int one = 1;
 165     int fd;
 166
 167     memset(&local, 0, sizeof(local));
 168     local.s_addr = htonl(INADDR_LOOPBACK);
 169
 170     fd = socket (AF_INET, SOCK_STREAM, 0);
 171     if (fd < 0)
 172         err (1, "socket AF_INET");
 173 #if defined(TCP_NODELAY) && defined(HAVE_SETSOCKOPT)
 174     setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, (void *)&one,
 175                 sizeof(one));
 176 #endif
 177     memset (&tcpaddr, 0, sizeof(tcpaddr));
 178     tcpaddr.sin_family = AF_INET;
 179     tcpaddr.sin_addr = local;
 180     tcpaddr.sin_port = htons(6000 + dpy);
 181     if (bind (fd, (struct sockaddr *)&tcpaddr,
 182               sizeof(tcpaddr)) < 0) {
 183         close (fd);
 184         if (errno == EADDRINUSE)
 185             return 1;
 186         else
 187             return -1;
 188     }
 189     s->fd = fd;
 190     s->pathname = NULL;
 191     s->flags = TCP;
 192     return 0;
 193 }
 194
 195 /*
 196  * The potential places to create unix sockets.
 197  */
 198
 199 static char *x_sockets[] = {
 200 X_UNIX_PATH "%u",
 201 "/var/X/.X11-unix/X" "%u",
 202 "/usr/spool/sockets/X11/" "%u",
 203 NULL
 204 };
 205
 206 /*
 207  * Dito for stream pipes.
 208  */
 209
 210 #ifdef MAY_HAVE_X11_PIPES
 211 static char *x_pipes[] = {
 212 X_PIPE_PATH "%u",
 213 "/var/X/.X11-pipe/X" "%u",
 214 NULL
 215 };
 216 #endif
 217
 218 /*
 219  * Create the directory corresponding to dirname of `path' or fail.
 220  */
 221
 222 static void
 223 try_mkdir (const char *path)
 224 {
 225     char *dir;
 226     char *p;
 227     int oldmask;
 228
 229     if((dir = strdup (path)) == NULL)
 230         errx (1, "strdup: out of memory");
 231     p = strrchr (dir, '/');
 232     if (p)
 233         *p = '\0';
 234
 235     oldmask = umask(0);
 236     mkdir (dir, 01777);
 237     umask (oldmask);
 238     free (dir);
 239 }
 240
 241 /*
 242  * Allocate a display, returning the number of sockets in `number' and
 243  * all the corresponding sockets in `sockets'.  If `tcp_socket' is
 244  * true, also allcoaet a TCP socket.
 245  *
 246  * The return value is the display allocated or -1 if an error occurred.
 247  */
 248
 249 int
 250 get_xsockets (int *number, struct x_socket **sockets, int tcp_socket)
 251 {
 252      int dpy;
 253      struct x_socket *s;
 254      int n;
 255      int i;
 256
 257      s = malloc (sizeof(*s) * 5);
 258      if (s == NULL)
 259          errx (1, "malloc: out of memory");
 260
 261      try_mkdir (X_UNIX_PATH);
 262      try_mkdir (X_PIPE_PATH);
 263
 264      for(dpy = 4; dpy < 256; ++dpy) {
 265          char **path;
 266          int tmp = 0;
 267
 268          n = 0;
 269          for (path = x_sockets; *path; ++path) {
 270              tmp = try_socket (&s[n], dpy, *path);
 271              if (tmp == -1) {
 272                  if (errno != ENOTDIR && errno != ENOENT)
 273                      err(1, "failed to open '%s'", *path);
 274              } else if (tmp == 1) {
 275                  while(--n >= 0) {
 276                      close (s[n].fd);
 277                      free (s[n].pathname);
 278                  }
 279                  break;
 280              } else if (tmp == 0)
 281                  ++n;
 282          }
 283          if (tmp == 1)
 284              continue;
 285
 286 #ifdef MAY_HAVE_X11_PIPES
 287          for (path = x_pipes; *path; ++path) {
 288              tmp = try_pipe (&s[n], dpy, *path);
 289              if (tmp == -1) {
 290                  if (errno != ENOTDIR && errno != ENOENT && errno != ENOSYS)
 291                      err(1, "failed to open '%s'", *path);
 292              } else if (tmp == 1) {
 293                  while (--n >= 0) {
 294                      close (s[n].fd);
 295                      free (s[n].pathname);
 296                  }
 297                  break;
 298              } else if (tmp == 0)
 299                  ++n;
 300          }
 301
 302          if (tmp == 1)
 303              continue;
 304 #endif
 305
 306          if (tcp_socket) {
 307              tmp = try_tcp (&s[n], dpy);
 308              if (tmp == -1)
 309                  err(1, "failed to open tcp stocket");
 310              else if (tmp == 1) {
 311                  while (--n >= 0) {
 312                      close (s[n].fd);
 313                      free (s[n].pathname);
 314                  }
 315                  break;
 316              } else if (tmp == 0)
 317                  ++n;
 318          }
 319          break;
 320      }
 321      if (dpy == 256)
 322          errx (1, "no free x-servers");
 323      for (i = 0; i < n; ++i)
 324          if (s[i].flags & LISTENP
 325              && listen (s[i].fd, SOMAXCONN) < 0)
 326              err (1, "listen %s", s[i].pathname ? s[i].pathname : "tcp");
 327      *number = n;
 328      *sockets = s;
 329      return dpy;
 330 }
 331
 332 /*
 333  * Change owner on the `n' sockets in `sockets' to `uid', `gid'.
 334  * Return 0 is succesful or -1 if an error occurred.
 335  */
 336
 337 int
 338 chown_xsockets (int n, struct x_socket *sockets, uid_t uid, gid_t gid)
 339 {
 340     int i;
 341
 342     for (i = 0; i < n; ++i)
 343         if (sockets[i].pathname != NULL)
 344             if (chown (sockets[i].pathname, uid, gid) < 0)
 345                 return -1;
 346     return 0;
 347 }
 348
 349 /*
 350  * Connect to local display `dnr' with local transport or TCP.
 351  * Return a file descriptor.
 352  */
 353
 354 int
 355 connect_local_xsocket (unsigned dnr)
 356 {
 357      int fd;
 358      char **path;
 359
 360      for (path = x_sockets; *path; ++path) {
 361          struct sockaddr_un addr;
 362
 363          fd = socket (AF_UNIX, SOCK_STREAM, 0);
 364          if (fd < 0)
 365              break;
 366          memset (&addr, 0, sizeof(addr));
 367          addr.sun_family = AF_UNIX;
 368          snprintf (addr.sun_path, sizeof(addr.sun_path), *path, dnr);
 369          if (connect (fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
 370              return fd;
 371          close(fd);
 372      }
 373      {
 374          struct sockaddr_in addr;
 375
 376          fd = socket(AF_INET, SOCK_STREAM, 0);
 377          if (fd < 0)
 378              err (1, "socket AF_INET");
 379          memset (&addr, 0, sizeof(addr));
 380          addr.sin_family = AF_INET;
 381          addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 382          addr.sin_port = htons(6000 + dnr);
 383          if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
 384              return fd;
 385          close(fd);
 386      }
 387      err (1, "connecting to local display %u", dnr);
 388 }
 389
 390 /*
 391  * Create a cookie file with a random cookie for the localhost.  The
 392  * file name will be stored in `xauthfile' (but not larger than
 393  * `xauthfile_size'), and the cookie returned in `cookie', `cookie_sz'.
 394  * Return 0 if succesful, or errno.
 395  */
 396
 397 int
 398 create_and_write_cookie (char *file,
 399                          size_t file_size,
 400                          u_char *cookie_buf,
 401                          size_t cookie_sz)
 402 {
 403      Xauth auth;
 404      char tmp[64];
 405      int fd;
 406      FILE *f;
 407      char hostname[MaxHostNameLen];
 408      int saved_errno;
 409
 410      gethostname (hostname, sizeof(hostname));
 411
 412      auth.family = FamilyLocal;
 413      auth.address = hostname;
 414      auth.address_length = strlen(auth.address);
 415      snprintf (tmp, sizeof(tmp), "%d", display_num);
 416      auth.number_length = strlen(tmp);
 417      auth.number = tmp;
 418      auth.name = COOKIE_TYPE;
 419      auth.name_length = strlen(auth.name);
 420      auth.data_length = cookie_sz;
 421      auth.data = (char*)cookie_buf;
 422 #ifdef KRB5
 423      krb5_generate_random_block (cookie_buf, cookie_sz);
 424 #else
 425      krb_generate_random_block (cookie_buf, cookie_sz);
 426 #endif
 427
 428      strlcpy(file, "/tmp/AXXXXXX", file_size);
 429      fd = mkstemp(file);
 430      if(fd < 0) {
 431          saved_errno = errno;
 432          syslog(LOG_ERR, "create_and_write_cookie: mkstemp: %m");
 433          return saved_errno;
 434      }
 435      f = fdopen(fd, "r+");
 436      if(f == NULL){
 437          saved_errno = errno;
 438          close(fd);
 439          return errno;
 440      }
 441      if(XauWriteAuth(f, &auth) == 0) {
 442          saved_errno = errno;
 443          fclose(f);
 444          return saved_errno;
 445      }
 446
 447      /*
 448       * I would like to write a cookie for localhost:n here, but some
 449       * stupid code in libX11 will not look for cookies of that type,
 450       * so we are forced to use FamilyWild instead.
 451       */
 452
 453      auth.family  = FamilyWild;
 454      auth.address_length = 0;
 455
 456      if (XauWriteAuth(f, &auth) == 0) {
 457          saved_errno = errno;
 458          fclose (f);
 459          return saved_errno;
 460      }
 461
 462      if(fclose(f))
 463          return errno;
 464      return 0;
 465 }
 466
 467 /*
 468  * Verify and remove cookies.  Read and parse a X-connection from
 469  * `fd'. Check the cookie used is the same as in `cookie'.  Remove the
 470  * cookie and copy the rest of it to `sock'.
 471  * Expect cookies iff cookiesp.
 472  * Return 0 iff ok.
 473  *
 474  * The protocol is as follows:
 475  *
 476  * C->S:        [Bl]                            1
 477  *              unused                          1
 478  *              protocol major version          2
 479  *              protocol minor version          2
 480  *              length of auth protocol name(n) 2
 481  *              length of auth protocol data    2
 482  *              unused                          2
 483  *              authorization protocol name     n
 484  *              pad                             pad(n)
 485  *              authorization protocol data     d
 486  *              pad                             pad(d)
 487  *
 488  * S->C:        Failed
 489  *              0                               1
 490  *              length of reason                1
 491  *              protocol major version          2
 492  *              protocol minor version          2
 493  *              length in 4 bytes unit of
 494  *              additional data (n+p)/4         2
 495  *              reason                          n
 496  *              unused                          p = pad(n)
 497  */
 498
 499 int
 500 verify_and_remove_cookies (int fd, int sock, int cookiesp)
 501 {
 502      u_char beg[12];
 503      int bigendianp;
 504      unsigned n, d, npad, dpad;
 505      char *protocol_name, *protocol_data;
 506      u_char zeros[6] = {0, 0, 0, 0, 0, 0};
 507      u_char refused[20] = {0, 10,
 508                            0, 0, /* protocol major version  */
 509                            0, 0, /* protocol minor version */
 510                            0, 0, /* length of additional data / 4 */
 511                            'b', 'a', 'd', ' ', 'c', 'o', 'o', 'k', 'i', 'e',
 512                            0, 0};
 513
 514      if (net_read (fd, beg, sizeof(beg)) != sizeof(beg))
 515           return 1;
 516      if (net_write (sock, beg, 6) != 6)
 517           return 1;
 518      bigendianp = beg[0] == 'B';
 519      if (bigendianp) {
 520           n = (beg[6] << 8) | beg[7];
 521           d = (beg[8] << 8) | beg[9];
 522      } else {
 523           n = (beg[7] << 8) | beg[6];
 524           d = (beg[9] << 8) | beg[8];
 525      }
 526      npad = (4 - (n % 4)) % 4;
 527      dpad = (4 - (d % 4)) % 4;
 528      protocol_name = malloc(n + npad);
 529      if (n + npad != 0 && protocol_name == NULL)
 530          return 1;
 531      protocol_data = malloc(d + dpad);
 532      if (d + dpad != 0 && protocol_data == NULL) {
 533          free (protocol_name);
 534          return 1;
 535      }
 536      if (net_read (fd, protocol_name, n + npad) != n + npad)
 537          goto fail;
 538      if (net_read (fd, protocol_data, d + dpad) != d + dpad)
 539          goto fail;
 540      if (cookiesp) {
 541          if (strncmp (protocol_name, COOKIE_TYPE, strlen(COOKIE_TYPE)) != 0)
 542              goto refused;
 543          if (d != cookie_len ||
 544              memcmp (protocol_data, cookie, cookie_len) != 0)
 545              goto refused;
 546      }
 547      free (protocol_name);
 548      free (protocol_data);
 549      if (net_write (sock, zeros, 6) != 6)
 550           return 1;
 551      return 0;
 552 refused:
 553      refused[2] = beg[2];
 554      refused[3] = beg[3];
 555      refused[4] = beg[4];
 556      refused[5] = beg[5];
 557      if (bigendianp)
 558          refused[7] = 3;
 559      else
 560          refused[6] = 3;
 561
 562      net_write (fd, refused, sizeof(refused));
 563 fail:
 564      free (protocol_name);
 565      free (protocol_data);
 566      return 1;
 567 }
 568
 569 /*
 570  * Return 0 iff `cookie' is compatible with the cookie for the
 571  * localhost with name given in `ai' (or `hostname') and display
 572  * number in `disp_nr'.
 573  */
 574
 575 static int
 576 match_local_auth (Xauth* auth,
 577                   struct addrinfo *ai, const char *hostname, int disp_nr)
 578 {
 579     int auth_disp;
 580     char *tmp_disp;
 581     struct addrinfo *a;
 582
 583     tmp_disp = malloc(auth->number_length + 1);
 584     if (tmp_disp == NULL)
 585         return -1;
 586     memcpy(tmp_disp, auth->number, auth->number_length);
 587     tmp_disp[auth->number_length] = '\0';
 588     auth_disp = atoi(tmp_disp);
 589     free (tmp_disp);
 590     if (auth_disp != disp_nr)
 591         return 1;
 592     for (a = ai; a != NULL; a = a->ai_next) {
 593         if ((auth->family == FamilyLocal
 594              || auth->family == FamilyWild)
 595             && a->ai_canonname != NULL
 596             && strncmp (auth->address,
 597                         a->ai_canonname,
 598                         auth->address_length) == 0)
 599             return 0;
 600     }
 601     if (hostname != NULL
 602         && (auth->family    == FamilyLocal
 603             || auth->family == FamilyWild)
 604         && strncmp (auth->address, hostname, auth->address_length) == 0)
 605         return 0;
 606     return 1;
 607 }
 608
 609 /*
 610  * Find `our' cookie from the cookie file `f' and return it or NULL.
 611  */
 612
 613 static Xauth*
 614 find_auth_cookie (FILE *f)
 615 {
 616     Xauth *ret = NULL;
 617     char local_hostname[MaxHostNameLen];
 618     char *display_str = getenv("DISPLAY");
 619     char d[MaxHostNameLen + 4];
 620     char *colon;
 621     struct addrinfo *ai;
 622     struct addrinfo hints;
 623     int disp;
 624     int error;
 625
 626     if(display_str == NULL)
 627         display_str = ":0";
 628     strlcpy(d, display_str, sizeof(d));
 629     display_str = d;
 630     colon = strchr (display_str, ':');
 631     if (colon == NULL)
 632         disp = 0;
 633     else {
 634         *colon = '\0';
 635         disp = atoi (colon + 1);
 636     }
 637     if (strcmp (display_str, "") == 0
 638         || strncmp (display_str, "unix", 4) == 0
 639         || strncmp (display_str, "localhost", 9) == 0) {
 640         gethostname (local_hostname, sizeof(local_hostname));
 641         display_str = local_hostname;
 642     }
 643     memset (&hints, 0, sizeof(hints));
 644     hints.ai_flags    = AI_CANONNAME;
 645     hints.ai_socktype = SOCK_STREAM;
 646     hints.ai_protocol = IPPROTO_TCP;
 647
 648     error = getaddrinfo (display_str, NULL, &hints, &ai);
 649     if (error)
 650         ai = NULL;
 651
 652     for (; (ret = XauReadAuth (f)) != NULL; XauDisposeAuth(ret)) {
 653         if (match_local_auth (ret, ai, display_str, disp) == 0) {
 654             if (ai != NULL)
 655                 freeaddrinfo (ai);
 656             return ret;
 657         }
 658     }
 659     if (ai != NULL)
 660         freeaddrinfo (ai);
 661     return NULL;
 662 }
 663
 664 /*
 665  * Get rid of the cookie that we were sent and get the correct one
 666  * from our own cookie file instead.
 667  */
 668
 669 int
 670 replace_cookie(int xserver, int fd, char *filename, int cookiesp) /* XXX */
 671 {
 672      u_char beg[12];
 673      int bigendianp;
 674      unsigned n, d, npad, dpad;
 675      FILE *f;
 676      u_char zeros[6] = {0, 0, 0, 0, 0, 0};
 677
 678      if (net_read (fd, beg, sizeof(beg)) != sizeof(beg))
 679           return 1;
 680      if (net_write (xserver, beg, 6) != 6)
 681           return 1;
 682      bigendianp = beg[0] == 'B';
 683      if (bigendianp) {
 684           n = (beg[6] << 8) | beg[7];
 685           d = (beg[8] << 8) | beg[9];
 686      } else {
 687           n = (beg[7] << 8) | beg[6];
 688           d = (beg[9] << 8) | beg[8];
 689      }
 690      if (n != 0 || d != 0)
 691           return 1;
 692      f = fopen(filename, "r");
 693      if (f != NULL) {
 694          Xauth *auth = find_auth_cookie (f);
 695          u_char len[6] = {0, 0, 0, 0, 0, 0};
 696
 697          fclose (f);
 698
 699          if (auth != NULL) {
 700              n = auth->name_length;
 701              d = auth->data_length;
 702          } else {
 703              n = 0;
 704              d = 0;
 705          }
 706          if (bigendianp) {
 707              len[0] = n >> 8;
 708              len[1] = n & 0xFF;
 709              len[2] = d >> 8;
 710              len[3] = d & 0xFF;
 711          } else {
 712              len[0] = n & 0xFF;
 713              len[1] = n >> 8;
 714              len[2] = d & 0xFF;
 715              len[3] = d >> 8;
 716          }
 717          if (net_write (xserver, len, 6) != 6) {
 718              XauDisposeAuth(auth);
 719              return 1;
 720          }
 721          if(n != 0 && net_write (xserver, auth->name, n) != n) {
 722              XauDisposeAuth(auth);
 723              return 1;
 724          }
 725          npad = (4 - (n % 4)) % 4;
 726          if (npad && net_write (xserver, zeros, npad) != npad) {
 727              XauDisposeAuth(auth);
 728              return 1;
 729          }
 730          if (d != 0 && net_write (xserver, auth->data, d) != d) {
 731              XauDisposeAuth(auth);
 732              return 1;
 733          }
 734          XauDisposeAuth(auth);
 735          dpad = (4 - (d % 4)) % 4;
 736          if (dpad && net_write (xserver, zeros, dpad) != dpad)
 737              return 1;
 738      } else {
 739          if(net_write(xserver, zeros, 6) != 6)
 740              return 1;
 741      }
 742      return 0;
 743 }
 744
 745 /*
 746  * Some simple controls on the address and corresponding socket
 747  */
 748
 749 int
 750 suspicious_address (int sock, struct sockaddr *addr)
 751 {
 752     char data[40];
 753     socklen_t len = sizeof(data);
 754
 755     switch (addr->sa_family) {
 756     case AF_INET:
 757         return ((struct sockaddr_in *)addr)->sin_addr.s_addr !=
 758             htonl(INADDR_LOOPBACK)
 759 #if defined(IP_OPTIONS) && defined(HAVE_GETSOCKOPT)
 760             || getsockopt (sock, IPPROTO_IP, IP_OPTIONS, data, &len) < 0
 761             || len != 0
 762 #endif
 763             ;
 764         break;
 765 #ifdef HAVE_IPV6
 766     case AF_INET6:
 767         /* XXX check route headers */
 768         return !IN6_IS_ADDR_LOOPBACK(&((struct sockaddr_in6*)addr)->sin6_addr);
 769 #endif
 770     default:
 771         return 1;
 772     }
 773 }
 774
 775 /*
 776  * This really sucks, but these functions are used and if we're not
 777  * linking against libkrb they don't exist.  Using the heimdal storage
 778  * functions will not work either cause we do not always link with
 779  * libkrb5 either.
 780  */
 781
 782 int
 783 kx_get_int(void *f, uint32_t *to, int size, int lsb)
 784 {
 785     int i;
 786     unsigned char *from = (unsigned char *)f;
 787
 788     *to = 0;
 789     if(lsb){
 790         for(i = size-1; i >= 0; i--)
 791             *to = (*to << 8) | from[i];
 792     }else{
 793         for(i = 0; i < size; i++)
 794             *to = (*to << 8) | from[i];
 795     }
 796     return size;
 797 }
 798
 799 int
 800 kx_put_int(uint32_t from, void *to, size_t rem, int size)
 801 {
 802     int i;
 803     unsigned char *p = (unsigned char *)to;
 804
 805     if (rem < size)
 806         return -1;
 807
 808     for(i = size - 1; i >= 0; i--){
 809         p[i] = from & 0xff;
 810         from >>= 8;
 811     }
 812     return size;
 813 }