kdc/connect.c

   1 /*
   2  * Copyright (c) 1997-2005 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 "kdc_locl.h"
  35
  36 /* Should we enable the HTTP hack? */
  37 int enable_http = -1;
  38
  39 /* Log over requests to the KDC */
  40 const char *request_log;
  41
  42 /* A string describing on what ports to listen */
  43 const char *port_str;
  44
  45 krb5_addresses explicit_addresses;
  46
  47 size_t max_request_udp;
  48 size_t max_request_tcp;
  49
  50 /*
  51  * a tuple describing on what to listen
  52  */
  53
  54 struct port_desc{
  55     int family;
  56     int type;
  57     int port;
  58 };
  59
  60 /* the current ones */
  61
  62 static struct port_desc *ports;
  63 static int num_ports;
  64
  65 /*
  66  * add `family, port, protocol' to the list with duplicate suppresion.
  67  */
  68
  69 static void
  70 add_port(krb5_context context,
  71          int family, int port, const char *protocol)
  72 {
  73     int type;
  74     int i;
  75
  76     if(strcmp(protocol, "udp") == 0)
  77         type = SOCK_DGRAM;
  78     else if(strcmp(protocol, "tcp") == 0)
  79         type = SOCK_STREAM;
  80     else
  81         return;
  82     for(i = 0; i < num_ports; i++){
  83         if(ports[i].type == type
  84            && ports[i].port == port
  85            && ports[i].family == family)
  86             return;
  87     }
  88     ports = realloc(ports, (num_ports + 1) * sizeof(*ports));
  89     if (ports == NULL)
  90         krb5_err (context, 1, errno, "realloc");
  91     ports[num_ports].family = family;
  92     ports[num_ports].type   = type;
  93     ports[num_ports].port   = port;
  94     num_ports++;
  95 }
  96
  97 /*
  98  * add a triple but with service -> port lookup
  99  * (this prints warnings for stuff that does not exist)
 100  */
 101
 102 static void
 103 add_port_service(krb5_context context,
 104                  int family, const char *service, int port,
 105                  const char *protocol)
 106 {
 107     port = krb5_getportbyname (context, service, protocol, port);
 108     add_port (context, family, port, protocol);
 109 }
 110
 111 /*
 112  * add the port with service -> port lookup or string -> number
 113  * (no warning is printed)
 114  */
 115
 116 static void
 117 add_port_string (krb5_context context,
 118                  int family, const char *str, const char *protocol)
 119 {
 120     struct servent *sp;
 121     int port;
 122
 123     sp = roken_getservbyname (str, protocol);
 124     if (sp != NULL) {
 125         port = sp->s_port;
 126     } else {
 127         char *end;
 128
 129         port = htons(strtol(str, &end, 0));
 130         if (end == str)
 131             return;
 132     }
 133     add_port (context, family, port, protocol);
 134 }
 135
 136 /*
 137  * add the standard collection of ports for `family'
 138  */
 139
 140 static void
 141 add_standard_ports (krb5_context context,
 142                     krb5_kdc_configuration *config,
 143                     int family)
 144 {
 145     add_port_service(context, family, "kerberos", 88, "udp");
 146     add_port_service(context, family, "kerberos", 88, "tcp");
 147     add_port_service(context, family, "kerberos-sec", 88, "udp");
 148     add_port_service(context, family, "kerberos-sec", 88, "tcp");
 149     if(enable_http)
 150         add_port_service(context, family, "http", 80, "tcp");
 151     if(config->enable_524) {
 152         add_port_service(context, family, "krb524", 4444, "udp");
 153         add_port_service(context, family, "krb524", 4444, "tcp");
 154     }
 155     if(config->enable_v4) {
 156         add_port_service(context, family, "kerberos-iv", 750, "udp");
 157         add_port_service(context, family, "kerberos-iv", 750, "tcp");
 158     }
 159     if (config->enable_kaserver)
 160         add_port_service(context, family, "afs3-kaserver", 7004, "udp");
 161     if(config->enable_kx509) {
 162         add_port_service(context, family, "kca_service", 9878, "udp");
 163         add_port_service(context, family, "kca_service", 9878, "tcp");
 164     }
 165
 166 }
 167
 168 /*
 169  * parse the set of space-delimited ports in `str' and add them.
 170  * "+" => all the standard ones
 171  * otherwise it's port|service[/protocol]
 172  */
 173
 174 static void
 175 parse_ports(krb5_context context,
 176             krb5_kdc_configuration *config,
 177             const char *str)
 178 {
 179     char *pos = NULL;
 180     char *p;
 181     char *str_copy = strdup (str);
 182
 183     p = strtok_r(str_copy, " \t", &pos);
 184     while(p != NULL) {
 185         if(strcmp(p, "+") == 0) {
 186 #ifdef HAVE_IPV6
 187             add_standard_ports(context, config, AF_INET6);
 188 #endif
 189             add_standard_ports(context, config, AF_INET);
 190         } else {
 191             char *q = strchr(p, '/');
 192             if(q){
 193                 *q++ = 0;
 194 #ifdef HAVE_IPV6
 195                 add_port_string(context, AF_INET6, p, q);
 196 #endif
 197                 add_port_string(context, AF_INET, p, q);
 198             }else {
 199 #ifdef HAVE_IPV6
 200                 add_port_string(context, AF_INET6, p, "udp");
 201                 add_port_string(context, AF_INET6, p, "tcp");
 202 #endif
 203                 add_port_string(context, AF_INET, p, "udp");
 204                 add_port_string(context, AF_INET, p, "tcp");
 205             }
 206         }
 207
 208         p = strtok_r(NULL, " \t", &pos);
 209     }
 210     free (str_copy);
 211 }
 212
 213 /*
 214  * every socket we listen on
 215  */
 216
 217 struct descr {
 218     krb5_socket_t s;
 219     int type;
 220     int port;
 221     unsigned char *buf;
 222     size_t size;
 223     size_t len;
 224     time_t timeout;
 225     struct sockaddr_storage __ss;
 226     struct sockaddr *sa;
 227     socklen_t sock_len;
 228     char addr_string[128];
 229 };
 230
 231 static void
 232 init_descr(struct descr *d)
 233 {
 234     memset(d, 0, sizeof(*d));
 235     d->sa = (struct sockaddr *)&d->__ss;
 236     d->s = rk_INVALID_SOCKET;
 237 }
 238
 239 /*
 240  * re-initialize all `n' ->sa in `d'.
 241  */
 242
 243 static void
 244 reinit_descrs (struct descr *d, int n)
 245 {
 246     int i;
 247
 248     for (i = 0; i < n; ++i)
 249         d[i].sa = (struct sockaddr *)&d[i].__ss;
 250 }
 251
 252 /*
 253  * Create the socket (family, type, port) in `d'
 254  */
 255
 256 static void
 257 init_socket(krb5_context context,
 258             krb5_kdc_configuration *config,
 259             struct descr *d, krb5_address *a, int family, int type, int port)
 260 {
 261     krb5_error_code ret;
 262     struct sockaddr_storage __ss;
 263     struct sockaddr *sa = (struct sockaddr *)&__ss;
 264     krb5_socklen_t sa_size = sizeof(__ss);
 265
 266     init_descr (d);
 267
 268     ret = krb5_addr2sockaddr (context, a, sa, &sa_size, port);
 269     if (ret) {
 270         krb5_warn(context, ret, "krb5_addr2sockaddr");
 271         rk_closesocket(d->s);
 272         d->s = rk_INVALID_SOCKET;
 273         return;
 274     }
 275
 276     if (sa->sa_family != family)
 277         return;
 278
 279     d->s = socket(family, type, 0);
 280     if(rk_IS_BAD_SOCKET(d->s)){
 281         krb5_warn(context, errno, "socket(%d, %d, 0)", family, type);
 282         d->s = rk_INVALID_SOCKET;
 283         return;
 284     }
 285 #if defined(HAVE_SETSOCKOPT) && defined(SOL_SOCKET) && defined(SO_REUSEADDR)
 286     {
 287         int one = 1;
 288         setsockopt(d->s, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
 289     }
 290 #endif
 291     d->type = type;
 292     d->port = port;
 293
 294     if(rk_IS_SOCKET_ERROR(bind(d->s, sa, sa_size))){
 295         char a_str[256];
 296         size_t len;
 297
 298         krb5_print_address (a, a_str, sizeof(a_str), &len);
 299         krb5_warn(context, errno, "bind %s/%d", a_str, ntohs(port));
 300         rk_closesocket(d->s);
 301         d->s = rk_INVALID_SOCKET;
 302         return;
 303     }
 304     if(type == SOCK_STREAM && rk_IS_SOCKET_ERROR(listen(d->s, SOMAXCONN))){
 305         char a_str[256];
 306         size_t len;
 307
 308         krb5_print_address (a, a_str, sizeof(a_str), &len);
 309         krb5_warn(context, errno, "listen %s/%d", a_str, ntohs(port));
 310         rk_closesocket(d->s);
 311         d->s = rk_INVALID_SOCKET;
 312         return;
 313     }
 314 }
 315
 316 /*
 317  * Allocate descriptors for all the sockets that we should listen on
 318  * and return the number of them.
 319  */
 320
 321 static int
 322 init_sockets(krb5_context context,
 323              krb5_kdc_configuration *config,
 324              struct descr **desc)
 325 {
 326     krb5_error_code ret;
 327     int i, j;
 328     struct descr *d;
 329     int num = 0;
 330     krb5_addresses addresses;
 331
 332     if (explicit_addresses.len) {
 333         addresses = explicit_addresses;
 334     } else {
 335         ret = krb5_get_all_server_addrs (context, &addresses);
 336         if (ret)
 337             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 338     }
 339     parse_ports(context, config, port_str);
 340     d = malloc(addresses.len * num_ports * sizeof(*d));
 341     if (d == NULL)
 342         krb5_errx(context, 1, "malloc(%lu) failed",
 343                   (unsigned long)num_ports * sizeof(*d));
 344
 345     for (i = 0; i < num_ports; i++){
 346         for (j = 0; j < addresses.len; ++j) {
 347             init_socket(context, config, &d[num], &addresses.val[j],
 348                         ports[i].family, ports[i].type, ports[i].port);
 349             if(d[num].s != rk_INVALID_SOCKET){
 350                 char a_str[80];
 351                 size_t len;
 352
 353                 krb5_print_address (&addresses.val[j], a_str,
 354                                     sizeof(a_str), &len);
 355
 356                 kdc_log(context, config, 5, "listening on %s port %u/%s",
 357                         a_str,
 358                         ntohs(ports[i].port),
 359                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 360                 /* XXX */
 361                 num++;
 362             }
 363         }
 364     }
 365     krb5_free_addresses (context, &addresses);
 366     d = realloc(d, num * sizeof(*d));
 367     if (d == NULL && num != 0)
 368         krb5_errx(context, 1, "realloc(%lu) failed",
 369                   (unsigned long)num * sizeof(*d));
 370     reinit_descrs (d, num);
 371     *desc = d;
 372     return num;
 373 }
 374
 375 /*
 376  *
 377  */
 378
 379 static const char *
 380 descr_type(struct descr *d)
 381 {
 382     if (d->type == SOCK_DGRAM)
 383         return "udp";
 384     else if (d->type == SOCK_STREAM)
 385         return "tcp";
 386     return "unknown";
 387 }
 388
 389 static void
 390 addr_to_string(krb5_context context,
 391                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 392 {
 393     krb5_address a;
 394     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 395         if(krb5_print_address(&a, str, len, &len) == 0) {
 396             krb5_free_address(context, &a);
 397             return;
 398         }
 399         krb5_free_address(context, &a);
 400     }
 401     snprintf(str, len, "<family=%d>", addr->sa_family);
 402 }
 403
 404 /*
 405  *
 406  */
 407
 408 static void
 409 send_reply(krb5_context context,
 410            krb5_kdc_configuration *config,
 411            krb5_boolean prependlength,
 412            struct descr *d,
 413            krb5_data *reply)
 414 {
 415     kdc_log(context, config, 5,
 416             "sending %lu bytes to %s", (unsigned long)reply->length,
 417             d->addr_string);
 418     if(prependlength){
 419         unsigned char l[4];
 420         l[0] = (reply->length >> 24) & 0xff;
 421         l[1] = (reply->length >> 16) & 0xff;
 422         l[2] = (reply->length >> 8) & 0xff;
 423         l[3] = reply->length & 0xff;
 424         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 425             kdc_log (context, config,
 426                      0, "sendto(%s): %s", d->addr_string,
 427                      strerror(rk_SOCK_ERRNO));
 428             return;
 429         }
 430     }
 431     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 432         kdc_log (context, config, 0, "sendto(%s): %s", d->addr_string,
 433                  strerror(rk_SOCK_ERRNO));
 434         return;
 435     }
 436 }
 437
 438 /*
 439  * Handle the request in `buf, len' to socket `d'
 440  */
 441
 442 static void
 443 do_request(krb5_context context,
 444            krb5_kdc_configuration *config,
 445            void *buf, size_t len, krb5_boolean prependlength,
 446            struct descr *d)
 447 {
 448     krb5_error_code ret;
 449     krb5_data reply;
 450     int datagram_reply = (d->type == SOCK_DGRAM);
 451
 452     krb5_kdc_update_time(NULL);
 453
 454     krb5_data_zero(&reply);
 455     ret = krb5_kdc_process_request(context, config,
 456                                    buf, len, &reply, &prependlength,
 457                                    d->addr_string, d->sa,
 458                                    datagram_reply);
 459     if(request_log)
 460         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 461     if(reply.length){
 462         send_reply(context, config, prependlength, d, &reply);
 463         krb5_data_free(&reply);
 464     }
 465     if(ret)
 466         kdc_log(context, config, 0,
 467                 "Failed processing %lu byte request from %s",
 468                 (unsigned long)len, d->addr_string);
 469 }
 470
 471 /*
 472  * Handle incoming data to the UDP socket in `d'
 473  */
 474
 475 static void
 476 handle_udp(krb5_context context,
 477            krb5_kdc_configuration *config,
 478            struct descr *d)
 479 {
 480     unsigned char *buf;
 481     int n;
 482
 483     buf = malloc(max_request_udp);
 484     if(buf == NULL){
 485         kdc_log(context, config, 0, "Failed to allocate %lu bytes", (unsigned long)max_request_udp);
 486         return;
 487     }
 488
 489     d->sock_len = sizeof(d->__ss);
 490     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 491     if(rk_IS_SOCKET_ERROR(n))
 492         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 493     else {
 494         addr_to_string (context, d->sa, d->sock_len,
 495                         d->addr_string, sizeof(d->addr_string));
 496         if (n == max_request_udp) {
 497             krb5_data data;
 498             krb5_warn(context, errno,
 499                       "recvfrom: truncated packet from %s, asking for TCP",
 500                       d->addr_string);
 501             krb5_mk_error(context,
 502                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 503                           NULL,
 504                           NULL,
 505                           NULL,
 506                           NULL,
 507                           NULL,
 508                           NULL,
 509                           &data);
 510             send_reply(context, config, FALSE, d, &data);
 511             krb5_data_free(&data);
 512         } else {
 513             do_request(context, config, buf, n, FALSE, d);
 514         }
 515     }
 516     free (buf);
 517 }
 518
 519 static void
 520 clear_descr(struct descr *d)
 521 {
 522     if(d->buf)
 523         memset(d->buf, 0, d->size);
 524     d->len = 0;
 525     if(d->s != rk_INVALID_SOCKET)
 526         rk_closesocket(d->s);
 527     d->s = rk_INVALID_SOCKET;
 528 }
 529
 530
 531 /* remove HTTP %-quoting from buf */
 532 static int
 533 de_http(char *buf)
 534 {
 535     unsigned char *p, *q;
 536     for(p = q = (unsigned char *)buf; *p; p++, q++) {
 537         if(*p == '%' && isxdigit(p[1]) && isxdigit(p[2])) {
 538             unsigned int x;
 539             if(sscanf((char *)p + 1, "%2x", &x) != 1)
 540                 return -1;
 541             *q = x;
 542             p += 2;
 543         } else
 544             *q = *p;
 545     }
 546     *q = '\0';
 547     return 0;
 548 }
 549
 550 #define TCP_TIMEOUT 4
 551
 552 /*
 553  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 554  */
 555
 556 static void
 557 add_new_tcp (krb5_context context,
 558              krb5_kdc_configuration *config,
 559              struct descr *d, int parent, int child)
 560 {
 561     krb5_socket_t s;
 562
 563     if (child == -1)
 564         return;
 565
 566     d[child].sock_len = sizeof(d[child].__ss);
 567     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 568     if(rk_IS_BAD_SOCKET(s)) {
 569         krb5_warn(context, rk_SOCK_ERRNO, "accept");
 570         return;
 571     }
 572
 573 #ifdef FD_SETSIZE
 574     if (s >= FD_SETSIZE) {
 575         krb5_warnx(context, "socket FD too large");
 576         rk_closesocket (s);
 577         return;
 578     }
 579 #endif
 580
 581     d[child].s = s;
 582     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 583     d[child].type = SOCK_STREAM;
 584     addr_to_string (context,
 585                     d[child].sa, d[child].sock_len,
 586                     d[child].addr_string, sizeof(d[child].addr_string));
 587 }
 588
 589 /*
 590  * Grow `d' to handle at least `n'.
 591  * Return != 0 if fails
 592  */
 593
 594 static int
 595 grow_descr (krb5_context context,
 596             krb5_kdc_configuration *config,
 597             struct descr *d, size_t n)
 598 {
 599     if (d->size - d->len < n) {
 600         unsigned char *tmp;
 601         size_t grow;
 602
 603         grow = max(1024, d->len + n);
 604         if (d->size + grow > max_request_tcp) {
 605             kdc_log(context, config, 0, "Request exceeds max request size (%lu bytes).",
 606                     (unsigned long)d->size + grow);
 607             clear_descr(d);
 608             return -1;
 609         }
 610         tmp = realloc (d->buf, d->size + grow);
 611         if (tmp == NULL) {
 612             kdc_log(context, config, 0, "Failed to re-allocate %lu bytes.",
 613                     (unsigned long)d->size + grow);
 614             clear_descr(d);
 615             return -1;
 616         }
 617         d->size += grow;
 618         d->buf = tmp;
 619     }
 620     return 0;
 621 }
 622
 623 /*
 624  * Try to handle the TCP data at `d->buf, d->len'.
 625  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 626  */
 627
 628 static int
 629 handle_vanilla_tcp (krb5_context context,
 630                     krb5_kdc_configuration *config,
 631                     struct descr *d)
 632 {
 633     krb5_storage *sp;
 634     uint32_t len;
 635
 636     sp = krb5_storage_from_mem(d->buf, d->len);
 637     if (sp == NULL) {
 638         kdc_log (context, config, 0, "krb5_storage_from_mem failed");
 639         return -1;
 640     }
 641     krb5_ret_uint32(sp, &len);
 642     krb5_storage_free(sp);
 643     if(d->len - 4 >= len) {
 644         memmove(d->buf, d->buf + 4, d->len - 4);
 645         d->len -= 4;
 646         return 1;
 647     }
 648     return 0;
 649 }
 650
 651 /*
 652  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 653  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 654  */
 655
 656 static int
 657 handle_http_tcp (krb5_context context,
 658                  krb5_kdc_configuration *config,
 659                  struct descr *d)
 660 {
 661     char *s, *p, *t;
 662     void *data;
 663     char *proto;
 664     int len;
 665
 666     s = (char *)d->buf;
 667
 668     /* If its a multi line query, truncate off the first line */
 669     p = strstr(s, "\r\n");
 670     if (p)
 671         *p = 0;
 672
 673     p = NULL;
 674     t = strtok_r(s, " \t", &p);
 675     if (t == NULL) {
 676         kdc_log(context, config, 0,
 677                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 678         return -1;
 679     }
 680
 681     t = strtok_r(NULL, " \t", &p);
 682     if(t == NULL) {
 683         kdc_log(context, config, 0,
 684                 "Missing HTTP GET data in request from %s", d->addr_string);
 685         return -1;
 686     }
 687
 688     data = malloc(strlen(t));
 689     if (data == NULL) {
 690         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 691                 (unsigned long)strlen(t));
 692         return -1;
 693     }
 694     if(*t == '/')
 695         t++;
 696     if(de_http(t) != 0) {
 697         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 698         kdc_log(context, config, 5, "HTTP request: %s", t);
 699         free(data);
 700         return -1;
 701     }
 702     proto = strtok_r(NULL, " \t", &p);
 703     if (proto == NULL) {
 704         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 705         free(data);
 706         return -1;
 707     }
 708     len = base64_decode(t, data);
 709     if(len <= 0){
 710         const char *msg =
 711             " 404 Not found\r\n"
 712             "Server: Heimdal/" VERSION "\r\n"
 713             "Cache-Control: no-cache\r\n"
 714             "Pragma: no-cache\r\n"
 715             "Content-type: text/html\r\n"
 716             "Content-transfer-encoding: 8bit\r\n\r\n"
 717             "<TITLE>404 Not found</TITLE>\r\n"
 718             "<H1>404 Not found</H1>\r\n"
 719             "That page doesn't exist, maybe you are looking for "
 720             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 721         kdc_log(context, config, 0, "HTTP request from %s is non KDC request", d->addr_string);
 722         kdc_log(context, config, 5, "HTTP request: %s", t);
 723         free(data);
 724         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 725             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 726                     d->addr_string, strerror(rk_SOCK_ERRNO));
 727             return -1;
 728         }
 729         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 730             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 731                     d->addr_string, strerror(rk_SOCK_ERRNO));
 732             return -1;
 733         }
 734         return -1;
 735     }
 736     {
 737         const char *msg =
 738             " 200 OK\r\n"
 739             "Server: Heimdal/" VERSION "\r\n"
 740             "Cache-Control: no-cache\r\n"
 741             "Pragma: no-cache\r\n"
 742             "Content-type: application/octet-stream\r\n"
 743             "Content-transfer-encoding: binary\r\n\r\n";
 744         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 745             free(data);
 746             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 747                     d->addr_string, strerror(rk_SOCK_ERRNO));
 748             return -1;
 749         }
 750         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 751             free(data);
 752             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 753                     d->addr_string, strerror(rk_SOCK_ERRNO));
 754             return -1;
 755         }
 756     }
 757     if (len > d->len)
 758         len = d->len;
 759     memcpy(d->buf, data, len);
 760     d->len = len;
 761     free(data);
 762     return 1;
 763 }
 764
 765 /*
 766  * Handle incoming data to the TCP socket in `d[index]'
 767  */
 768
 769 static void
 770 handle_tcp(krb5_context context,
 771            krb5_kdc_configuration *config,
 772            struct descr *d, int idx, int min_free)
 773 {
 774     unsigned char buf[1024];
 775     int n;
 776     int ret = 0;
 777
 778     if (d[idx].timeout == 0) {
 779         add_new_tcp (context, config, d, idx, min_free);
 780         return;
 781     }
 782
 783     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 784     if(rk_IS_SOCKET_ERROR(n)){
 785         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 786                   d[idx].addr_string, descr_type(d + idx),
 787                   ntohs(d[idx].port));
 788         return;
 789     } else if (n == 0) {
 790         krb5_warnx(context, "connection closed before end of data after %lu "
 791                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 792                    d[idx].addr_string, descr_type(d + idx),
 793                    ntohs(d[idx].port));
 794         clear_descr (d + idx);
 795         return;
 796     }
 797     if (grow_descr (context, config, &d[idx], n))
 798         return;
 799     memcpy(d[idx].buf + d[idx].len, buf, n);
 800     d[idx].len += n;
 801     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 802         ret = handle_vanilla_tcp (context, config, &d[idx]);
 803     } else if(enable_http &&
 804               d[idx].len >= 4 &&
 805               strncmp((char *)d[idx].buf, "GET ", 4) == 0 &&
 806               strncmp((char *)d[idx].buf + d[idx].len - 4,
 807                       "\r\n\r\n", 4) == 0) {
 808
 809         /* remove the trailing \r\n\r\n so the string is NUL terminated */
 810         d[idx].buf[d[idx].len - 4] = '\0';
 811
 812         ret = handle_http_tcp (context, config, &d[idx]);
 813         if (ret < 0)
 814             clear_descr (d + idx);
 815     } else if (d[idx].len > 4) {
 816         kdc_log (context, config,
 817                  0, "TCP data of strange type from %s to %s/%d",
 818                  d[idx].addr_string, descr_type(d + idx),
 819                  ntohs(d[idx].port));
 820         if (d[idx].buf[0] & 0x80) {
 821             krb5_data reply;
 822
 823             kdc_log (context, config, 0, "TCP extension not supported");
 824
 825             ret = krb5_mk_error(context,
 826                                 KRB5KRB_ERR_FIELD_TOOLONG,
 827                                 NULL,
 828                                 NULL,
 829                                 NULL,
 830                                 NULL,
 831                                 NULL,
 832                                 NULL,
 833                                 &reply);
 834             if (ret == 0) {
 835                 send_reply(context, config, TRUE, d + idx, &reply);
 836                 krb5_data_free(&reply);
 837             }
 838         }
 839         clear_descr(d + idx);
 840         return;
 841     }
 842     if (ret < 0)
 843         return;
 844     else if (ret == 1) {
 845         do_request(context, config,
 846                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 847         clear_descr(d + idx);
 848     }
 849 }
 850
 851 void
 852 loop(krb5_context context,
 853      krb5_kdc_configuration *config)
 854 {
 855     struct descr *d;
 856     unsigned int ndescr;
 857
 858     ndescr = init_sockets(context, config, &d);
 859     if(ndescr <= 0)
 860         krb5_errx(context, 1, "No sockets!");
 861     kdc_log(context, config, 0, "KDC started");
 862     while(exit_flag == 0){
 863         struct timeval tmout;
 864         fd_set fds;
 865         int min_free = -1;
 866         int max_fd = 0;
 867         int i;
 868
 869         FD_ZERO(&fds);
 870         for(i = 0; i < ndescr; i++) {
 871             if(!rk_IS_BAD_SOCKET(d[i].s)){
 872                 if(d[i].type == SOCK_STREAM &&
 873                    d[i].timeout && d[i].timeout < time(NULL)) {
 874                     kdc_log(context, config, 1,
 875                             "TCP-connection from %s expired after %lu bytes",
 876                             d[i].addr_string, (unsigned long)d[i].len);
 877                     clear_descr(&d[i]);
 878                     continue;
 879                 }
 880 #ifndef NO_LIMIT_FD_SETSIZE
 881                 if(max_fd < d[i].s)
 882                     max_fd = d[i].s;
 883 #ifdef FD_SETSIZE
 884                 if (max_fd >= FD_SETSIZE)
 885                     krb5_errx(context, 1, "fd too large");
 886 #endif
 887 #endif
 888                 FD_SET(d[i].s, &fds);
 889             } else if(min_free < 0 || i < min_free)
 890                 min_free = i;
 891         }
 892         if(min_free == -1){
 893             struct descr *tmp;
 894             tmp = realloc(d, (ndescr + 4) * sizeof(*d));
 895             if(tmp == NULL)
 896                 krb5_warnx(context, "No memory");
 897             else {
 898                 d = tmp;
 899                 reinit_descrs (d, ndescr);
 900                 memset(d + ndescr, 0, 4 * sizeof(*d));
 901                 for(i = ndescr; i < ndescr + 4; i++)
 902                     init_descr (&d[i]);
 903                 min_free = ndescr;
 904                 ndescr += 4;
 905             }
 906         }
 907
 908         tmout.tv_sec = TCP_TIMEOUT;
 909         tmout.tv_usec = 0;
 910         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 911         case 0:
 912             break;
 913         case -1:
 914             if (errno != EINTR)
 915                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 916             break;
 917         default:
 918             for(i = 0; i < ndescr; i++)
 919                 if(!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 920                     if(d[i].type == SOCK_DGRAM)
 921                         handle_udp(context, config, &d[i]);
 922                     else if(d[i].type == SOCK_STREAM)
 923                         handle_tcp(context, config, d, i, min_free);
 924                 }
 925         }
 926     }
 927     if (0);
 928 #ifdef SIGXCPU
 929     else if(exit_flag == SIGXCPU)
 930         kdc_log(context, config, 0, "CPU time limit exceeded");
 931 #endif
 932     else if(exit_flag == SIGINT || exit_flag == SIGTERM)
 933         kdc_log(context, config, 0, "Terminated");
 934     else
 935         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
 936     free (d);
 937 }