crypto/external/bsd/heimdal/dist/kdc/connect.c

   1 /*      $NetBSD: connect.c,v 1.1.1.2 2014/04/24 12:45:27 pettai Exp $   */
   2
   3 /*
   4  * Copyright (c) 1997-2005 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "kdc_locl.h"
  37
  38 /* Should we enable the HTTP hack? */
  39 int enable_http = -1;
  40
  41 /* Log over requests to the KDC */
  42 const char *request_log;
  43
  44 /* A string describing on what ports to listen */
  45 const char *port_str;
  46
  47 krb5_addresses explicit_addresses;
  48
  49 size_t max_request_udp;
  50 size_t max_request_tcp;
  51
  52 /*
  53  * a tuple describing on what to listen
  54  */
  55
  56 struct port_desc{
  57     int family;
  58     int type;
  59     int port;
  60 };
  61
  62 /* the current ones */
  63
  64 static struct port_desc *ports;
  65 static size_t num_ports;
  66
  67 /*
  68  * add `family, port, protocol' to the list with duplicate suppresion.
  69  */
  70
  71 static void
  72 add_port(krb5_context context,
  73          int family, int port, const char *protocol)
  74 {
  75     int type;
  76     size_t i;
  77
  78     if(strcmp(protocol, "udp") == 0)
  79         type = SOCK_DGRAM;
  80     else if(strcmp(protocol, "tcp") == 0)
  81         type = SOCK_STREAM;
  82     else
  83         return;
  84     for(i = 0; i < num_ports; i++){
  85         if(ports[i].type == type
  86            && ports[i].port == port
  87            && ports[i].family == family)
  88             return;
  89     }
  90     ports = realloc(ports, (num_ports + 1) * sizeof(*ports));
  91     if (ports == NULL)
  92         krb5_err (context, 1, errno, "realloc");
  93     ports[num_ports].family = family;
  94     ports[num_ports].type   = type;
  95     ports[num_ports].port   = port;
  96     num_ports++;
  97 }
  98
  99 /*
 100  * add a triple but with service -> port lookup
 101  * (this prints warnings for stuff that does not exist)
 102  */
 103
 104 static void
 105 add_port_service(krb5_context context,
 106                  int family, const char *service, int port,
 107                  const char *protocol)
 108 {
 109     port = krb5_getportbyname (context, service, protocol, port);
 110     add_port (context, family, port, protocol);
 111 }
 112
 113 /*
 114  * add the port with service -> port lookup or string -> number
 115  * (no warning is printed)
 116  */
 117
 118 static void
 119 add_port_string (krb5_context context,
 120                  int family, const char *str, const char *protocol)
 121 {
 122     struct servent *sp;
 123     int port;
 124
 125     sp = roken_getservbyname (str, protocol);
 126     if (sp != NULL) {
 127         port = sp->s_port;
 128     } else {
 129         char *end;
 130
 131         port = htons(strtol(str, &end, 0));
 132         if (end == str)
 133             return;
 134     }
 135     add_port (context, family, port, protocol);
 136 }
 137
 138 /*
 139  * add the standard collection of ports for `family'
 140  */
 141
 142 static void
 143 add_standard_ports (krb5_context context,
 144                     krb5_kdc_configuration *config,
 145                     int family)
 146 {
 147     add_port_service(context, family, "kerberos", 88, "udp");
 148     add_port_service(context, family, "kerberos", 88, "tcp");
 149     add_port_service(context, family, "kerberos-sec", 88, "udp");
 150     add_port_service(context, family, "kerberos-sec", 88, "tcp");
 151     if(enable_http)
 152         add_port_service(context, family, "http", 80, "tcp");
 153     if(config->enable_kx509) {
 154         add_port_service(context, family, "kca_service", 9878, "udp");
 155         add_port_service(context, family, "kca_service", 9878, "tcp");
 156     }
 157
 158 }
 159
 160 /*
 161  * parse the set of space-delimited ports in `str' and add them.
 162  * "+" => all the standard ones
 163  * otherwise it's port|service[/protocol]
 164  */
 165
 166 static void
 167 parse_ports(krb5_context context,
 168             krb5_kdc_configuration *config,
 169             const char *str)
 170 {
 171     char *pos = NULL;
 172     char *p;
 173     char *str_copy = strdup (str);
 174
 175     p = strtok_r(str_copy, " \t", &pos);
 176     while(p != NULL) {
 177         if(strcmp(p, "+") == 0) {
 178 #ifdef HAVE_IPV6
 179             add_standard_ports(context, config, AF_INET6);
 180 #endif
 181             add_standard_ports(context, config, AF_INET);
 182         } else {
 183             char *q = strchr(p, '/');
 184             if(q){
 185                 *q++ = 0;
 186 #ifdef HAVE_IPV6
 187                 add_port_string(context, AF_INET6, p, q);
 188 #endif
 189                 add_port_string(context, AF_INET, p, q);
 190             }else {
 191 #ifdef HAVE_IPV6
 192                 add_port_string(context, AF_INET6, p, "udp");
 193                 add_port_string(context, AF_INET6, p, "tcp");
 194 #endif
 195                 add_port_string(context, AF_INET, p, "udp");
 196                 add_port_string(context, AF_INET, p, "tcp");
 197             }
 198         }
 199
 200         p = strtok_r(NULL, " \t", &pos);
 201     }
 202     free (str_copy);
 203 }
 204
 205 /*
 206  * every socket we listen on
 207  */
 208
 209 struct descr {
 210     krb5_socket_t s;
 211     int type;
 212     int port;
 213     unsigned char *buf;
 214     size_t size;
 215     size_t len;
 216     time_t timeout;
 217     struct sockaddr_storage __ss;
 218     struct sockaddr *sa;
 219     socklen_t sock_len;
 220     char addr_string[128];
 221 };
 222
 223 static void
 224 init_descr(struct descr *d)
 225 {
 226     memset(d, 0, sizeof(*d));
 227     d->sa = (struct sockaddr *)&d->__ss;
 228     d->s = rk_INVALID_SOCKET;
 229 }
 230
 231 /*
 232  * re-initialize all `n' ->sa in `d'.
 233  */
 234
 235 static void
 236 reinit_descrs (struct descr *d, int n)
 237 {
 238     int i;
 239
 240     for (i = 0; i < n; ++i)
 241         d[i].sa = (struct sockaddr *)&d[i].__ss;
 242 }
 243
 244 /*
 245  * Create the socket (family, type, port) in `d'
 246  */
 247
 248 static void
 249 init_socket(krb5_context context,
 250             krb5_kdc_configuration *config,
 251             struct descr *d, krb5_address *a, int family, int type, int port)
 252 {
 253     krb5_error_code ret;
 254     struct sockaddr_storage __ss;
 255     struct sockaddr *sa = (struct sockaddr *)&__ss;
 256     krb5_socklen_t sa_size = sizeof(__ss);
 257
 258     init_descr (d);
 259
 260     ret = krb5_addr2sockaddr (context, a, sa, &sa_size, port);
 261     if (ret) {
 262         krb5_warn(context, ret, "krb5_addr2sockaddr");
 263         rk_closesocket(d->s);
 264         d->s = rk_INVALID_SOCKET;
 265         return;
 266     }
 267
 268     if (sa->sa_family != family)
 269         return;
 270
 271     d->s = socket(family, type, 0);
 272     if(rk_IS_BAD_SOCKET(d->s)){
 273         krb5_warn(context, errno, "socket(%d, %d, 0)", family, type);
 274         d->s = rk_INVALID_SOCKET;
 275         return;
 276     }
 277 #if defined(HAVE_SETSOCKOPT) && defined(SOL_SOCKET) && defined(SO_REUSEADDR)
 278     {
 279         int one = 1;
 280         setsockopt(d->s, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
 281     }
 282 #endif
 283     d->type = type;
 284     d->port = port;
 285
 286     if(rk_IS_SOCKET_ERROR(bind(d->s, sa, sa_size))){
 287         char a_str[256];
 288         size_t len;
 289
 290         krb5_print_address (a, a_str, sizeof(a_str), &len);
 291         krb5_warn(context, errno, "bind %s/%d", a_str, ntohs(port));
 292         rk_closesocket(d->s);
 293         d->s = rk_INVALID_SOCKET;
 294         return;
 295     }
 296     if(type == SOCK_STREAM && rk_IS_SOCKET_ERROR(listen(d->s, SOMAXCONN))){
 297         char a_str[256];
 298         size_t len;
 299
 300         krb5_print_address (a, a_str, sizeof(a_str), &len);
 301         krb5_warn(context, errno, "listen %s/%d", a_str, ntohs(port));
 302         rk_closesocket(d->s);
 303         d->s = rk_INVALID_SOCKET;
 304         return;
 305     }
 306 }
 307
 308 /*
 309  * Allocate descriptors for all the sockets that we should listen on
 310  * and return the number of them.
 311  */
 312
 313 static int
 314 init_sockets(krb5_context context,
 315              krb5_kdc_configuration *config,
 316              struct descr **desc)
 317 {
 318     krb5_error_code ret;
 319     size_t i, j;
 320     struct descr *d;
 321     int num = 0;
 322     krb5_addresses addresses;
 323
 324     if (explicit_addresses.len) {
 325         addresses = explicit_addresses;
 326     } else {
 327         ret = krb5_get_all_server_addrs (context, &addresses);
 328         if (ret)
 329             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 330     }
 331     parse_ports(context, config, port_str);
 332     d = malloc(addresses.len * num_ports * sizeof(*d));
 333     if (d == NULL)
 334         krb5_errx(context, 1, "malloc(%lu) failed",
 335                   (unsigned long)num_ports * sizeof(*d));
 336
 337     for (i = 0; i < num_ports; i++){
 338         for (j = 0; j < addresses.len; ++j) {
 339             init_socket(context, config, &d[num], &addresses.val[j],
 340                         ports[i].family, ports[i].type, ports[i].port);
 341             if(d[num].s != rk_INVALID_SOCKET){
 342                 char a_str[80];
 343                 size_t len;
 344
 345                 krb5_print_address (&addresses.val[j], a_str,
 346                                     sizeof(a_str), &len);
 347
 348                 kdc_log(context, config, 5, "listening on %s port %u/%s",
 349                         a_str,
 350                         ntohs(ports[i].port),
 351                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 352                 /* XXX */
 353                 num++;
 354             }
 355         }
 356     }
 357     krb5_free_addresses (context, &addresses);
 358     d = realloc(d, num * sizeof(*d));
 359     if (d == NULL && num != 0)
 360         krb5_errx(context, 1, "realloc(%lu) failed",
 361                   (unsigned long)num * sizeof(*d));
 362     reinit_descrs (d, num);
 363     *desc = d;
 364     return num;
 365 }
 366
 367 /*
 368  *
 369  */
 370
 371 static const char *
 372 descr_type(struct descr *d)
 373 {
 374     if (d->type == SOCK_DGRAM)
 375         return "udp";
 376     else if (d->type == SOCK_STREAM)
 377         return "tcp";
 378     return "unknown";
 379 }
 380
 381 static void
 382 addr_to_string(krb5_context context,
 383                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 384 {
 385     krb5_address a;
 386     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 387         if(krb5_print_address(&a, str, len, &len) == 0) {
 388             krb5_free_address(context, &a);
 389             return;
 390         }
 391         krb5_free_address(context, &a);
 392     }
 393     snprintf(str, len, "<family=%d>", addr->sa_family);
 394 }
 395
 396 /*
 397  *
 398  */
 399
 400 static void
 401 send_reply(krb5_context context,
 402            krb5_kdc_configuration *config,
 403            krb5_boolean prependlength,
 404            struct descr *d,
 405            krb5_data *reply)
 406 {
 407     kdc_log(context, config, 5,
 408             "sending %lu bytes to %s", (unsigned long)reply->length,
 409             d->addr_string);
 410     if(prependlength){
 411         unsigned char l[4];
 412         l[0] = (reply->length >> 24) & 0xff;
 413         l[1] = (reply->length >> 16) & 0xff;
 414         l[2] = (reply->length >> 8) & 0xff;
 415         l[3] = reply->length & 0xff;
 416         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 417             kdc_log (context, config,
 418                      0, "sendto(%s): %s", d->addr_string,
 419                      strerror(rk_SOCK_ERRNO));
 420             return;
 421         }
 422     }
 423     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 424         kdc_log (context, config, 0, "sendto(%s): %s", d->addr_string,
 425                  strerror(rk_SOCK_ERRNO));
 426         return;
 427     }
 428 }
 429
 430 /*
 431  * Handle the request in `buf, len' to socket `d'
 432  */
 433
 434 static void
 435 do_request(krb5_context context,
 436            krb5_kdc_configuration *config,
 437            void *buf, size_t len, krb5_boolean prependlength,
 438            struct descr *d)
 439 {
 440     krb5_error_code ret;
 441     krb5_data reply;
 442     int datagram_reply = (d->type == SOCK_DGRAM);
 443
 444     krb5_kdc_update_time(NULL);
 445
 446     krb5_data_zero(&reply);
 447     ret = krb5_kdc_process_request(context, config,
 448                                    buf, len, &reply, &prependlength,
 449                                    d->addr_string, d->sa,
 450                                    datagram_reply);
 451     if(request_log)
 452         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 453     if(reply.length){
 454         send_reply(context, config, prependlength, d, &reply);
 455         krb5_data_free(&reply);
 456     }
 457     if(ret)
 458         kdc_log(context, config, 0,
 459                 "Failed processing %lu byte request from %s",
 460                 (unsigned long)len, d->addr_string);
 461 }
 462
 463 /*
 464  * Handle incoming data to the UDP socket in `d'
 465  */
 466
 467 static void
 468 handle_udp(krb5_context context,
 469            krb5_kdc_configuration *config,
 470            struct descr *d)
 471 {
 472     unsigned char *buf;
 473     ssize_t n;
 474
 475     buf = malloc(max_request_udp);
 476     if(buf == NULL){
 477         kdc_log(context, config, 0, "Failed to allocate %lu bytes", (unsigned long)max_request_udp);
 478         return;
 479     }
 480
 481     d->sock_len = sizeof(d->__ss);
 482     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 483     if(rk_IS_SOCKET_ERROR(n))
 484         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 485     else {
 486         addr_to_string (context, d->sa, d->sock_len,
 487                         d->addr_string, sizeof(d->addr_string));
 488         if ((size_t)n == max_request_udp) {
 489             krb5_data data;
 490             krb5_warn(context, errno,
 491                       "recvfrom: truncated packet from %s, asking for TCP",
 492                       d->addr_string);
 493             krb5_mk_error(context,
 494                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 495                           NULL,
 496                           NULL,
 497                           NULL,
 498                           NULL,
 499                           NULL,
 500                           NULL,
 501                           &data);
 502             send_reply(context, config, FALSE, d, &data);
 503             krb5_data_free(&data);
 504         } else {
 505             do_request(context, config, buf, n, FALSE, d);
 506         }
 507     }
 508     free (buf);
 509 }
 510
 511 static void
 512 clear_descr(struct descr *d)
 513 {
 514     if(d->buf)
 515         memset(d->buf, 0, d->size);
 516     d->len = 0;
 517     if(d->s != rk_INVALID_SOCKET)
 518         rk_closesocket(d->s);
 519     d->s = rk_INVALID_SOCKET;
 520 }
 521
 522
 523 /* remove HTTP %-quoting from buf */
 524 static int
 525 de_http(char *buf)
 526 {
 527     unsigned char *p, *q;
 528     for(p = q = (unsigned char *)buf; *p; p++, q++) {
 529         if(*p == '%' && isxdigit(p[1]) && isxdigit(p[2])) {
 530             unsigned int x;
 531             if(sscanf((char *)p + 1, "%2x", &x) != 1)
 532                 return -1;
 533             *q = x;
 534             p += 2;
 535         } else
 536             *q = *p;
 537     }
 538     *q = '\0';
 539     return 0;
 540 }
 541
 542 #define TCP_TIMEOUT 4
 543
 544 /*
 545  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 546  */
 547
 548 static void
 549 add_new_tcp (krb5_context context,
 550              krb5_kdc_configuration *config,
 551              struct descr *d, int parent, int child)
 552 {
 553     krb5_socket_t s;
 554
 555     if (child == -1)
 556         return;
 557
 558     d[child].sock_len = sizeof(d[child].__ss);
 559     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 560     if(rk_IS_BAD_SOCKET(s)) {
 561         krb5_warn(context, rk_SOCK_ERRNO, "accept");
 562         return;
 563     }
 564
 565 #ifdef FD_SETSIZE
 566     if (s >= FD_SETSIZE) {
 567         krb5_warnx(context, "socket FD too large");
 568         rk_closesocket (s);
 569         return;
 570     }
 571 #endif
 572
 573     d[child].s = s;
 574     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 575     d[child].type = SOCK_STREAM;
 576     addr_to_string (context,
 577                     d[child].sa, d[child].sock_len,
 578                     d[child].addr_string, sizeof(d[child].addr_string));
 579 }
 580
 581 /*
 582  * Grow `d' to handle at least `n'.
 583  * Return != 0 if fails
 584  */
 585
 586 static int
 587 grow_descr (krb5_context context,
 588             krb5_kdc_configuration *config,
 589             struct descr *d, size_t n)
 590 {
 591     if (d->size - d->len < n) {
 592         unsigned char *tmp;
 593         size_t grow;
 594
 595         grow = max(1024, d->len + n);
 596         if (d->size + grow > max_request_tcp) {
 597             kdc_log(context, config, 0, "Request exceeds max request size (%lu bytes).",
 598                     (unsigned long)d->size + grow);
 599             clear_descr(d);
 600             return -1;
 601         }
 602         tmp = realloc (d->buf, d->size + grow);
 603         if (tmp == NULL) {
 604             kdc_log(context, config, 0, "Failed to re-allocate %lu bytes.",
 605                     (unsigned long)d->size + grow);
 606             clear_descr(d);
 607             return -1;
 608         }
 609         d->size += grow;
 610         d->buf = tmp;
 611     }
 612     return 0;
 613 }
 614
 615 /*
 616  * Try to handle the TCP data at `d->buf, d->len'.
 617  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 618  */
 619
 620 static int
 621 handle_vanilla_tcp (krb5_context context,
 622                     krb5_kdc_configuration *config,
 623                     struct descr *d)
 624 {
 625     krb5_storage *sp;
 626     uint32_t len;
 627
 628     sp = krb5_storage_from_mem(d->buf, d->len);
 629     if (sp == NULL) {
 630         kdc_log (context, config, 0, "krb5_storage_from_mem failed");
 631         return -1;
 632     }
 633     krb5_ret_uint32(sp, &len);
 634     krb5_storage_free(sp);
 635     if(d->len - 4 >= len) {
 636         memmove(d->buf, d->buf + 4, d->len - 4);
 637         d->len -= 4;
 638         return 1;
 639     }
 640     return 0;
 641 }
 642
 643 /*
 644  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 645  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 646  */
 647
 648 static int
 649 handle_http_tcp (krb5_context context,
 650                  krb5_kdc_configuration *config,
 651                  struct descr *d)
 652 {
 653     char *s, *p, *t;
 654     void *data;
 655     char *proto;
 656     int len;
 657
 658     s = (char *)d->buf;
 659
 660     /* If its a multi line query, truncate off the first line */
 661     p = strstr(s, "\r\n");
 662     if (p)
 663         *p = 0;
 664
 665     p = NULL;
 666     t = strtok_r(s, " \t", &p);
 667     if (t == NULL) {
 668         kdc_log(context, config, 0,
 669                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 670         return -1;
 671     }
 672
 673     t = strtok_r(NULL, " \t", &p);
 674     if(t == NULL) {
 675         kdc_log(context, config, 0,
 676                 "Missing HTTP GET data in request from %s", d->addr_string);
 677         return -1;
 678     }
 679
 680     data = malloc(strlen(t));
 681     if (data == NULL) {
 682         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 683                 (unsigned long)strlen(t));
 684         return -1;
 685     }
 686     if(*t == '/')
 687         t++;
 688     if(de_http(t) != 0) {
 689         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 690         kdc_log(context, config, 5, "HTTP request: %s", t);
 691         free(data);
 692         return -1;
 693     }
 694     proto = strtok_r(NULL, " \t", &p);
 695     if (proto == NULL) {
 696         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 697         free(data);
 698         return -1;
 699     }
 700     len = base64_decode(t, data);
 701     if(len <= 0){
 702         const char *msg =
 703             " 404 Not found\r\n"
 704             "Server: Heimdal/" VERSION "\r\n"
 705             "Cache-Control: no-cache\r\n"
 706             "Pragma: no-cache\r\n"
 707             "Content-type: text/html\r\n"
 708             "Content-transfer-encoding: 8bit\r\n\r\n"
 709             "<TITLE>404 Not found</TITLE>\r\n"
 710             "<H1>404 Not found</H1>\r\n"
 711             "That page doesn't exist, maybe you are looking for "
 712             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 713         kdc_log(context, config, 0, "HTTP request from %s is non KDC request", d->addr_string);
 714         kdc_log(context, config, 5, "HTTP request: %s", t);
 715         free(data);
 716         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 717             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 718                     d->addr_string, strerror(rk_SOCK_ERRNO));
 719             return -1;
 720         }
 721         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 722             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 723                     d->addr_string, strerror(rk_SOCK_ERRNO));
 724             return -1;
 725         }
 726         return -1;
 727     }
 728     {
 729         const char *msg =
 730             " 200 OK\r\n"
 731             "Server: Heimdal/" VERSION "\r\n"
 732             "Cache-Control: no-cache\r\n"
 733             "Pragma: no-cache\r\n"
 734             "Content-type: application/octet-stream\r\n"
 735             "Content-transfer-encoding: binary\r\n\r\n";
 736         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 737             free(data);
 738             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 739                     d->addr_string, strerror(rk_SOCK_ERRNO));
 740             return -1;
 741         }
 742         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 743             free(data);
 744             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 745                     d->addr_string, strerror(rk_SOCK_ERRNO));
 746             return -1;
 747         }
 748     }
 749     if ((size_t)len > d->len)
 750         len = d->len;
 751     memcpy(d->buf, data, len);
 752     d->len = len;
 753     free(data);
 754     return 1;
 755 }
 756
 757 /*
 758  * Handle incoming data to the TCP socket in `d[index]'
 759  */
 760
 761 static void
 762 handle_tcp(krb5_context context,
 763            krb5_kdc_configuration *config,
 764            struct descr *d, int idx, int min_free)
 765 {
 766     unsigned char buf[1024];
 767     int n;
 768     int ret = 0;
 769
 770     if (d[idx].timeout == 0) {
 771         add_new_tcp (context, config, d, idx, min_free);
 772         return;
 773     }
 774
 775     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 776     if(rk_IS_SOCKET_ERROR(n)){
 777         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 778                   d[idx].addr_string, descr_type(d + idx),
 779                   ntohs(d[idx].port));
 780         return;
 781     } else if (n == 0) {
 782         krb5_warnx(context, "connection closed before end of data after %lu "
 783                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 784                    d[idx].addr_string, descr_type(d + idx),
 785                    ntohs(d[idx].port));
 786         clear_descr (d + idx);
 787         return;
 788     }
 789     if (grow_descr (context, config, &d[idx], n))
 790         return;
 791     memcpy(d[idx].buf + d[idx].len, buf, n);
 792     d[idx].len += n;
 793     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 794         ret = handle_vanilla_tcp (context, config, &d[idx]);
 795     } else if(enable_http &&
 796               d[idx].len >= 4 &&
 797               strncmp((char *)d[idx].buf, "GET ", 4) == 0 &&
 798               strncmp((char *)d[idx].buf + d[idx].len - 4,
 799                       "\r\n\r\n", 4) == 0) {
 800
 801         /* remove the trailing \r\n\r\n so the string is NUL terminated */
 802         d[idx].buf[d[idx].len - 4] = '\0';
 803
 804         ret = handle_http_tcp (context, config, &d[idx]);
 805         if (ret < 0)
 806             clear_descr (d + idx);
 807     } else if (d[idx].len > 4) {
 808         kdc_log (context, config,
 809                  0, "TCP data of strange type from %s to %s/%d",
 810                  d[idx].addr_string, descr_type(d + idx),
 811                  ntohs(d[idx].port));
 812         if (d[idx].buf[0] & 0x80) {
 813             krb5_data reply;
 814
 815             kdc_log (context, config, 0, "TCP extension not supported");
 816
 817             ret = krb5_mk_error(context,
 818                                 KRB5KRB_ERR_FIELD_TOOLONG,
 819                                 NULL,
 820                                 NULL,
 821                                 NULL,
 822                                 NULL,
 823                                 NULL,
 824                                 NULL,
 825                                 &reply);
 826             if (ret == 0) {
 827                 send_reply(context, config, TRUE, d + idx, &reply);
 828                 krb5_data_free(&reply);
 829             }
 830         }
 831         clear_descr(d + idx);
 832         return;
 833     }
 834     if (ret < 0)
 835         return;
 836     else if (ret == 1) {
 837         do_request(context, config,
 838                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 839         clear_descr(d + idx);
 840     }
 841 }
 842
 843 krb5_boolean
 844 realloc_descrs(struct descr **d, unsigned int *ndescr)
 845 {
 846     struct descr *tmp;
 847     size_t i;
 848
 849     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 850     if(tmp == NULL)
 851         return FALSE;
 852
 853     *d = tmp;
 854     reinit_descrs (*d, *ndescr);
 855     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 856     for(i = *ndescr; i < *ndescr + 4; i++)
 857         init_descr (*d + i);
 858
 859     *ndescr += 4;
 860
 861     return TRUE;
 862 }
 863
 864 int
 865 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 866 {
 867     size_t i;
 868     int min_free;
 869
 870     for(i = 0; i < *ndescr; i++) {
 871         int s = (*d + i)->s;
 872         if(rk_IS_BAD_SOCKET(s))
 873             return i;
 874     }
 875
 876     min_free = *ndescr;
 877     if(!realloc_descrs(d, ndescr)) {
 878         min_free = -1;
 879         krb5_warnx(context, "No memory");
 880     }
 881
 882     return min_free;
 883 }
 884
 885 void
 886 loop(krb5_context context,
 887      krb5_kdc_configuration *config)
 888 {
 889     struct descr *d;
 890     unsigned int ndescr;
 891
 892     ndescr = init_sockets(context, config, &d);
 893     if(ndescr <= 0)
 894         krb5_errx(context, 1, "No sockets!");
 895     kdc_log(context, config, 0, "KDC started");
 896     while(exit_flag == 0){
 897         struct timeval tmout;
 898         fd_set fds;
 899         int min_free = -1;
 900         int max_fd = 0;
 901         size_t i;
 902
 903         FD_ZERO(&fds);
 904         for(i = 0; i < ndescr; i++) {
 905             if(!rk_IS_BAD_SOCKET(d[i].s)){
 906                 if(d[i].type == SOCK_STREAM &&
 907                    d[i].timeout && d[i].timeout < time(NULL)) {
 908                     kdc_log(context, config, 1,
 909                             "TCP-connection from %s expired after %lu bytes",
 910                             d[i].addr_string, (unsigned long)d[i].len);
 911                     clear_descr(&d[i]);
 912                     continue;
 913                 }
 914 #ifndef NO_LIMIT_FD_SETSIZE
 915                 if(max_fd < d[i].s)
 916                     max_fd = d[i].s;
 917 #ifdef FD_SETSIZE
 918                 if (max_fd >= FD_SETSIZE)
 919                     krb5_errx(context, 1, "fd too large");
 920 #endif
 921 #endif
 922                 FD_SET(d[i].s, &fds);
 923             }
 924         }
 925
 926         tmout.tv_sec = TCP_TIMEOUT;
 927         tmout.tv_usec = 0;
 928         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 929         case 0:
 930             break;
 931         case -1:
 932             if (errno != EINTR)
 933                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 934             break;
 935         default:
 936             for(i = 0; i < ndescr; i++)
 937                 if(!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 938             min_free = next_min_free(context, &d, &ndescr);
 939
 940             if(d[i].type == SOCK_DGRAM)
 941                 handle_udp(context, config, &d[i]);
 942             else if(d[i].type == SOCK_STREAM)
 943                 handle_tcp(context, config, d, i, min_free);
 944                 }
 945         }
 946     }
 947     if (0);
 948 #ifdef SIGXCPU
 949     else if(exit_flag == SIGXCPU)
 950         kdc_log(context, config, 0, "CPU time limit exceeded");
 951 #endif
 952     else if(exit_flag == SIGINT || exit_flag == SIGTERM)
 953         kdc_log(context, config, 0, "Terminated");
 954     else
 955         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
 956     free (d);
 957 }