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 /*
  37  * a tuple describing on what to listen
  38  */
  39
  40 struct port_desc{
  41     int family;
  42     int type;
  43     int port;
  44 };
  45
  46 /* the current ones */
  47
  48 static struct port_desc *ports;
  49 static size_t num_ports;
  50
  51 /*
  52  * add `family, port, protocol' to the list with duplicate suppresion.
  53  */
  54
  55 static void
  56 add_port(krb5_context context,
  57          int family, int port, const char *protocol)
  58 {
  59     int type;
  60     size_t i;
  61
  62     if(strcmp(protocol, "udp") == 0)
  63         type = SOCK_DGRAM;
  64     else if(strcmp(protocol, "tcp") == 0)
  65         type = SOCK_STREAM;
  66     else
  67         return;
  68     for(i = 0; i < num_ports; i++){
  69         if(ports[i].type == type
  70            && ports[i].port == port
  71            && ports[i].family == family)
  72             return;
  73     }
  74     ports = realloc(ports, (num_ports + 1) * sizeof(*ports));
  75     if (ports == NULL)
  76         krb5_err (context, 1, errno, "realloc");
  77     ports[num_ports].family = family;
  78     ports[num_ports].type   = type;
  79     ports[num_ports].port   = port;
  80     num_ports++;
  81 }
  82
  83 /*
  84  * add a triple but with service -> port lookup
  85  * (this prints warnings for stuff that does not exist)
  86  */
  87
  88 static void
  89 add_port_service(krb5_context context,
  90                  int family, const char *service, int port,
  91                  const char *protocol)
  92 {
  93     port = krb5_getportbyname (context, service, protocol, port);
  94     add_port (context, family, port, protocol);
  95 }
  96
  97 /*
  98  * add the port with service -> port lookup or string -> number
  99  * (no warning is printed)
 100  */
 101
 102 static void
 103 add_port_string (krb5_context context,
 104                  int family, const char *str, const char *protocol)
 105 {
 106     struct servent *sp;
 107     int port;
 108
 109     sp = roken_getservbyname (str, protocol);
 110     if (sp != NULL) {
 111         port = sp->s_port;
 112     } else {
 113         char *end;
 114
 115         port = htons(strtol(str, &end, 0));
 116         if (end == str)
 117             return;
 118     }
 119     add_port (context, family, port, protocol);
 120 }
 121
 122 /*
 123  * add the standard collection of ports for `family'
 124  */
 125
 126 static void
 127 add_standard_ports (krb5_context context,
 128                     krb5_kdc_configuration *config,
 129                     int family)
 130 {
 131     add_port_service(context, family, "kerberos", 88, "udp");
 132     add_port_service(context, family, "kerberos", 88, "tcp");
 133     add_port_service(context, family, "kerberos-sec", 88, "udp");
 134     add_port_service(context, family, "kerberos-sec", 88, "tcp");
 135     if(enable_http)
 136         add_port_service(context, family, "http", 80, "tcp");
 137     if(config->enable_kx509) {
 138         add_port_service(context, family, "kca_service", 9878, "udp");
 139         add_port_service(context, family, "kca_service", 9878, "tcp");
 140     }
 141
 142 }
 143
 144 /*
 145  * parse the set of space-delimited ports in `str' and add them.
 146  * "+" => all the standard ones
 147  * otherwise it's port|service[/protocol]
 148  */
 149
 150 static void
 151 parse_ports(krb5_context context,
 152             krb5_kdc_configuration *config,
 153             const char *str)
 154 {
 155     char *pos = NULL;
 156     char *p;
 157     char *str_copy = strdup (str);
 158
 159     p = strtok_r(str_copy, " \t", &pos);
 160     while(p != NULL) {
 161         if(strcmp(p, "+") == 0) {
 162 #ifdef HAVE_IPV6
 163             add_standard_ports(context, config, AF_INET6);
 164 #endif
 165             add_standard_ports(context, config, AF_INET);
 166         } else {
 167             char *q = strchr(p, '/');
 168             if(q){
 169                 *q++ = 0;
 170 #ifdef HAVE_IPV6
 171                 add_port_string(context, AF_INET6, p, q);
 172 #endif
 173                 add_port_string(context, AF_INET, p, q);
 174             }else {
 175 #ifdef HAVE_IPV6
 176                 add_port_string(context, AF_INET6, p, "udp");
 177                 add_port_string(context, AF_INET6, p, "tcp");
 178 #endif
 179                 add_port_string(context, AF_INET, p, "udp");
 180                 add_port_string(context, AF_INET, p, "tcp");
 181             }
 182         }
 183
 184         p = strtok_r(NULL, " \t", &pos);
 185     }
 186     free (str_copy);
 187 }
 188
 189 /*
 190  * every socket we listen on
 191  */
 192
 193 struct descr {
 194     krb5_socket_t s;
 195     int type;
 196     int port;
 197     unsigned char *buf;
 198     size_t size;
 199     size_t len;
 200     time_t timeout;
 201     struct sockaddr_storage __ss;
 202     struct sockaddr *sa;
 203     socklen_t sock_len;
 204     char addr_string[128];
 205 };
 206
 207 static void
 208 init_descr(struct descr *d)
 209 {
 210     memset(d, 0, sizeof(*d));
 211     d->sa = (struct sockaddr *)&d->__ss;
 212     d->s = rk_INVALID_SOCKET;
 213 }
 214
 215 /*
 216  * re-initialize all `n' ->sa in `d'.
 217  */
 218
 219 static void
 220 reinit_descrs (struct descr *d, int n)
 221 {
 222     int i;
 223
 224     for (i = 0; i < n; ++i)
 225         d[i].sa = (struct sockaddr *)&d[i].__ss;
 226 }
 227
 228 /*
 229  * Create the socket (family, type, port) in `d'
 230  */
 231
 232 static void
 233 init_socket(krb5_context context,
 234             krb5_kdc_configuration *config,
 235             struct descr *d, krb5_address *a, int family, int type, int port)
 236 {
 237     krb5_error_code ret;
 238     struct sockaddr_storage __ss;
 239     struct sockaddr *sa = (struct sockaddr *)&__ss;
 240     krb5_socklen_t sa_size = sizeof(__ss);
 241
 242     init_descr (d);
 243
 244     ret = krb5_addr2sockaddr (context, a, sa, &sa_size, port);
 245     if (ret) {
 246         krb5_warn(context, ret, "krb5_addr2sockaddr");
 247         rk_closesocket(d->s);
 248         d->s = rk_INVALID_SOCKET;
 249         return;
 250     }
 251
 252     if (sa->sa_family != family)
 253         return;
 254
 255     d->s = socket(family, type, 0);
 256     if(rk_IS_BAD_SOCKET(d->s)){
 257         krb5_warn(context, errno, "socket(%d, %d, 0)", family, type);
 258         d->s = rk_INVALID_SOCKET;
 259         return;
 260     }
 261 #if defined(HAVE_SETSOCKOPT) && defined(SOL_SOCKET) && defined(SO_REUSEADDR)
 262     {
 263         int one = 1;
 264         setsockopt(d->s, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
 265     }
 266 #endif
 267     d->type = type;
 268     d->port = port;
 269
 270     socket_set_nonblocking(d->s, 1);
 271
 272     if(rk_IS_SOCKET_ERROR(bind(d->s, sa, sa_size))){
 273         char a_str[256];
 274         size_t len;
 275
 276         krb5_print_address (a, a_str, sizeof(a_str), &len);
 277         krb5_warn(context, errno, "bind %s/%d", a_str, ntohs(port));
 278         rk_closesocket(d->s);
 279         d->s = rk_INVALID_SOCKET;
 280         return;
 281     }
 282     if(type == SOCK_STREAM && rk_IS_SOCKET_ERROR(listen(d->s, SOMAXCONN))){
 283         char a_str[256];
 284         size_t len;
 285
 286         krb5_print_address (a, a_str, sizeof(a_str), &len);
 287         krb5_warn(context, errno, "listen %s/%d", a_str, ntohs(port));
 288         rk_closesocket(d->s);
 289         d->s = rk_INVALID_SOCKET;
 290         return;
 291     }
 292 }
 293
 294 /*
 295  * Allocate descriptors for all the sockets that we should listen on
 296  * and return the number of them.
 297  */
 298
 299 static int
 300 init_sockets(krb5_context context,
 301              krb5_kdc_configuration *config,
 302              struct descr **desc)
 303 {
 304     krb5_error_code ret;
 305     size_t i, j;
 306     struct descr *d;
 307     int num = 0;
 308     krb5_addresses addresses;
 309
 310     if (explicit_addresses.len) {
 311         addresses = explicit_addresses;
 312     } else {
 313         ret = krb5_get_all_server_addrs (context, &addresses);
 314         if (ret)
 315             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 316     }
 317     parse_ports(context, config, port_str);
 318     d = malloc(addresses.len * num_ports * sizeof(*d));
 319     if (d == NULL)
 320         krb5_errx(context, 1, "malloc(%lu) failed",
 321                   (unsigned long)num_ports * sizeof(*d));
 322
 323     for (i = 0; i < num_ports; i++){
 324         for (j = 0; j < addresses.len; ++j) {
 325             init_socket(context, config, &d[num], &addresses.val[j],
 326                         ports[i].family, ports[i].type, ports[i].port);
 327             if(d[num].s != rk_INVALID_SOCKET){
 328                 char a_str[80];
 329                 size_t len;
 330
 331                 krb5_print_address (&addresses.val[j], a_str,
 332                                     sizeof(a_str), &len);
 333
 334                 kdc_log(context, config, 5, "listening on %s port %u/%s",
 335                         a_str,
 336                         ntohs(ports[i].port),
 337                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 338                 /* XXX */
 339                 num++;
 340             }
 341         }
 342     }
 343     krb5_free_addresses (context, &addresses);
 344     d = realloc(d, num * sizeof(*d));
 345     if (d == NULL && num != 0)
 346         krb5_errx(context, 1, "realloc(%lu) failed",
 347                   (unsigned long)num * sizeof(*d));
 348     reinit_descrs (d, num);
 349     *desc = d;
 350     return num;
 351 }
 352
 353 /*
 354  *
 355  */
 356
 357 static const char *
 358 descr_type(struct descr *d)
 359 {
 360     if (d->type == SOCK_DGRAM)
 361         return "udp";
 362     else if (d->type == SOCK_STREAM)
 363         return "tcp";
 364     return "unknown";
 365 }
 366
 367 static void
 368 addr_to_string(krb5_context context,
 369                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 370 {
 371     krb5_address a;
 372     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 373         if(krb5_print_address(&a, str, len, &len) == 0) {
 374             krb5_free_address(context, &a);
 375             return;
 376         }
 377         krb5_free_address(context, &a);
 378     }
 379     snprintf(str, len, "<family=%d>", addr->sa_family);
 380 }
 381
 382 /*
 383  *
 384  */
 385
 386 static void
 387 send_reply(krb5_context context,
 388            krb5_kdc_configuration *config,
 389            krb5_boolean prependlength,
 390            struct descr *d,
 391            krb5_data *reply)
 392 {
 393     kdc_log(context, config, 5,
 394             "sending %lu bytes to %s", (unsigned long)reply->length,
 395             d->addr_string);
 396     if(prependlength){
 397         unsigned char l[4];
 398         l[0] = (reply->length >> 24) & 0xff;
 399         l[1] = (reply->length >> 16) & 0xff;
 400         l[2] = (reply->length >> 8) & 0xff;
 401         l[3] = reply->length & 0xff;
 402         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 403             kdc_log (context, config,
 404                      0, "sendto(%s): %s", d->addr_string,
 405                      strerror(rk_SOCK_ERRNO));
 406             return;
 407         }
 408     }
 409     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 410         kdc_log (context, config, 0, "sendto(%s): %s", d->addr_string,
 411                  strerror(rk_SOCK_ERRNO));
 412         return;
 413     }
 414 }
 415
 416 /*
 417  * Handle the request in `buf, len' to socket `d'
 418  */
 419
 420 static void
 421 do_request(krb5_context context,
 422            krb5_kdc_configuration *config,
 423            void *buf, size_t len, krb5_boolean prependlength,
 424            struct descr *d)
 425 {
 426     krb5_error_code ret;
 427     krb5_data reply;
 428     int datagram_reply = (d->type == SOCK_DGRAM);
 429
 430     krb5_kdc_update_time(NULL);
 431
 432     krb5_data_zero(&reply);
 433     ret = krb5_kdc_process_request(context, config,
 434                                    buf, len, &reply, &prependlength,
 435                                    d->addr_string, d->sa,
 436                                    datagram_reply);
 437     if(request_log)
 438         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 439     if(reply.length){
 440         send_reply(context, config, prependlength, d, &reply);
 441         krb5_data_free(&reply);
 442     }
 443     if(ret)
 444         kdc_log(context, config, 0,
 445                 "Failed processing %lu byte request from %s",
 446                 (unsigned long)len, d->addr_string);
 447 }
 448
 449 /*
 450  * Handle incoming data to the UDP socket in `d'
 451  */
 452
 453 static void
 454 handle_udp(krb5_context context,
 455            krb5_kdc_configuration *config,
 456            struct descr *d)
 457 {
 458     unsigned char *buf;
 459     ssize_t n;
 460
 461     buf = malloc(max_request_udp);
 462     if (buf == NULL){
 463         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 464                 (unsigned long)max_request_udp);
 465         return;
 466     }
 467
 468     d->sock_len = sizeof(d->__ss);
 469     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 470     if (rk_IS_SOCKET_ERROR(n)) {
 471         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 472             krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 473     } else {
 474         addr_to_string (context, d->sa, d->sock_len,
 475                         d->addr_string, sizeof(d->addr_string));
 476         if ((size_t)n == max_request_udp) {
 477             krb5_data data;
 478             krb5_warn(context, errno,
 479                       "recvfrom: truncated packet from %s, asking for TCP",
 480                       d->addr_string);
 481             krb5_mk_error(context,
 482                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 483                           NULL,
 484                           NULL,
 485                           NULL,
 486                           NULL,
 487                           NULL,
 488                           NULL,
 489                           &data);
 490             send_reply(context, config, FALSE, d, &data);
 491             krb5_data_free(&data);
 492         } else {
 493             do_request(context, config, buf, n, FALSE, d);
 494         }
 495     }
 496     free (buf);
 497 }
 498
 499 static void
 500 clear_descr(struct descr *d)
 501 {
 502     if(d->buf)
 503         memset(d->buf, 0, d->size);
 504     d->len = 0;
 505     if(d->s != rk_INVALID_SOCKET)
 506         rk_closesocket(d->s);
 507     d->s = rk_INVALID_SOCKET;
 508 }
 509
 510
 511 /* remove HTTP %-quoting from buf */
 512 static int
 513 de_http(char *buf)
 514 {
 515     unsigned char *p, *q;
 516     for(p = q = (unsigned char *)buf; *p; p++, q++) {
 517         if(*p == '%' && isxdigit(p[1]) && isxdigit(p[2])) {
 518             unsigned int x;
 519             if(sscanf((char *)p + 1, "%2x", &x) != 1)
 520                 return -1;
 521             *q = x;
 522             p += 2;
 523         } else
 524             *q = *p;
 525     }
 526     *q = '\0';
 527     return 0;
 528 }
 529
 530 #define TCP_TIMEOUT 4
 531
 532 /*
 533  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 534  */
 535
 536 static void
 537 add_new_tcp (krb5_context context,
 538              krb5_kdc_configuration *config,
 539              struct descr *d, int parent, int child)
 540 {
 541     krb5_socket_t s;
 542
 543     if (child == -1)
 544         return;
 545
 546     d[child].sock_len = sizeof(d[child].__ss);
 547     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 548     if(rk_IS_BAD_SOCKET(s)) {
 549         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 550             krb5_warn(context, rk_SOCK_ERRNO, "accept");
 551         return;
 552     }
 553
 554 #ifdef FD_SETSIZE
 555     if (s >= FD_SETSIZE) {
 556         krb5_warnx(context, "socket FD too large");
 557         rk_closesocket (s);
 558         return;
 559     }
 560 #endif
 561
 562     d[child].s = s;
 563     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 564     d[child].type = SOCK_STREAM;
 565     addr_to_string (context,
 566                     d[child].sa, d[child].sock_len,
 567                     d[child].addr_string, sizeof(d[child].addr_string));
 568 }
 569
 570 /*
 571  * Grow `d' to handle at least `n'.
 572  * Return != 0 if fails
 573  */
 574
 575 static int
 576 grow_descr (krb5_context context,
 577             krb5_kdc_configuration *config,
 578             struct descr *d, size_t n)
 579 {
 580     if (d->size - d->len < n) {
 581         unsigned char *tmp;
 582         size_t grow;
 583
 584         grow = max(1024, d->len + n);
 585         if (d->size + grow > max_request_tcp) {
 586             kdc_log(context, config, 0, "Request exceeds max request size (%lu bytes).",
 587                     (unsigned long)d->size + grow);
 588             clear_descr(d);
 589             return -1;
 590         }
 591         tmp = realloc (d->buf, d->size + grow);
 592         if (tmp == NULL) {
 593             kdc_log(context, config, 0, "Failed to re-allocate %lu bytes.",
 594                     (unsigned long)d->size + grow);
 595             clear_descr(d);
 596             return -1;
 597         }
 598         d->size += grow;
 599         d->buf = tmp;
 600     }
 601     return 0;
 602 }
 603
 604 /*
 605  * Try to handle the TCP data at `d->buf, d->len'.
 606  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 607  */
 608
 609 static int
 610 handle_vanilla_tcp (krb5_context context,
 611                     krb5_kdc_configuration *config,
 612                     struct descr *d)
 613 {
 614     krb5_storage *sp;
 615     uint32_t len;
 616
 617     sp = krb5_storage_from_mem(d->buf, d->len);
 618     if (sp == NULL) {
 619         kdc_log (context, config, 0, "krb5_storage_from_mem failed");
 620         return -1;
 621     }
 622     krb5_ret_uint32(sp, &len);
 623     krb5_storage_free(sp);
 624     if(d->len - 4 >= len) {
 625         memmove(d->buf, d->buf + 4, d->len - 4);
 626         d->len -= 4;
 627         return 1;
 628     }
 629     return 0;
 630 }
 631
 632 /*
 633  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 634  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 635  */
 636
 637 static int
 638 handle_http_tcp (krb5_context context,
 639                  krb5_kdc_configuration *config,
 640                  struct descr *d)
 641 {
 642     char *s, *p, *t;
 643     void *data;
 644     char *proto;
 645     int len;
 646
 647     s = (char *)d->buf;
 648
 649     /* If its a multi line query, truncate off the first line */
 650     p = strstr(s, "\r\n");
 651     if (p)
 652         *p = 0;
 653
 654     p = NULL;
 655     t = strtok_r(s, " \t", &p);
 656     if (t == NULL) {
 657         kdc_log(context, config, 0,
 658                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 659         return -1;
 660     }
 661
 662     t = strtok_r(NULL, " \t", &p);
 663     if(t == NULL) {
 664         kdc_log(context, config, 0,
 665                 "Missing HTTP GET data in request from %s", d->addr_string);
 666         return -1;
 667     }
 668
 669     data = malloc(strlen(t));
 670     if (data == NULL) {
 671         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 672                 (unsigned long)strlen(t));
 673         return -1;
 674     }
 675     if(*t == '/')
 676         t++;
 677     if(de_http(t) != 0) {
 678         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 679         kdc_log(context, config, 5, "HTTP request: %s", t);
 680         free(data);
 681         return -1;
 682     }
 683     proto = strtok_r(NULL, " \t", &p);
 684     if (proto == NULL) {
 685         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 686         free(data);
 687         return -1;
 688     }
 689     len = rk_base64_decode(t, data);
 690     if(len <= 0){
 691         const char *msg =
 692             " 404 Not found\r\n"
 693             "Server: Heimdal/" VERSION "\r\n"
 694             "Cache-Control: no-cache\r\n"
 695             "Pragma: no-cache\r\n"
 696             "Content-type: text/html\r\n"
 697             "Content-transfer-encoding: 8bit\r\n\r\n"
 698             "<TITLE>404 Not found</TITLE>\r\n"
 699             "<H1>404 Not found</H1>\r\n"
 700             "That page doesn't exist, maybe you are looking for "
 701             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 702         kdc_log(context, config, 0, "HTTP request from %s is non KDC request", d->addr_string);
 703         kdc_log(context, config, 5, "HTTP request: %s", t);
 704         free(data);
 705         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 706             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 707                     d->addr_string, strerror(rk_SOCK_ERRNO));
 708             return -1;
 709         }
 710         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 711             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 712                     d->addr_string, strerror(rk_SOCK_ERRNO));
 713             return -1;
 714         }
 715         return -1;
 716     }
 717     {
 718         const char *msg =
 719             " 200 OK\r\n"
 720             "Server: Heimdal/" VERSION "\r\n"
 721             "Cache-Control: no-cache\r\n"
 722             "Pragma: no-cache\r\n"
 723             "Content-type: application/octet-stream\r\n"
 724             "Content-transfer-encoding: binary\r\n\r\n";
 725         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 726             free(data);
 727             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 728                     d->addr_string, strerror(rk_SOCK_ERRNO));
 729             return -1;
 730         }
 731         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 732             free(data);
 733             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 734                     d->addr_string, strerror(rk_SOCK_ERRNO));
 735             return -1;
 736         }
 737     }
 738     if ((size_t)len > d->len)
 739         len = d->len;
 740     memcpy(d->buf, data, len);
 741     d->len = len;
 742     free(data);
 743     return 1;
 744 }
 745
 746 /*
 747  * Handle incoming data to the TCP socket in `d[index]'
 748  */
 749
 750 static void
 751 handle_tcp(krb5_context context,
 752            krb5_kdc_configuration *config,
 753            struct descr *d, int idx, int min_free)
 754 {
 755     unsigned char buf[1024];
 756     int n;
 757     int ret = 0;
 758
 759     if (d[idx].timeout == 0) {
 760         add_new_tcp (context, config, d, idx, min_free);
 761         return;
 762     }
 763
 764     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 765     if(rk_IS_SOCKET_ERROR(n)){
 766         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 767                   d[idx].addr_string, descr_type(d + idx),
 768                   ntohs(d[idx].port));
 769         return;
 770     } else if (n == 0) {
 771         krb5_warnx(context, "connection closed before end of data after %lu "
 772                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 773                    d[idx].addr_string, descr_type(d + idx),
 774                    ntohs(d[idx].port));
 775         clear_descr (d + idx);
 776         return;
 777     }
 778     if (grow_descr (context, config, &d[idx], n))
 779         return;
 780     memcpy(d[idx].buf + d[idx].len, buf, n);
 781     d[idx].len += n;
 782     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 783         ret = handle_vanilla_tcp (context, config, &d[idx]);
 784     } else if(enable_http &&
 785               d[idx].len >= 4 &&
 786               strncmp((char *)d[idx].buf, "GET ", 4) == 0 &&
 787               strncmp((char *)d[idx].buf + d[idx].len - 4,
 788                       "\r\n\r\n", 4) == 0) {
 789
 790         /* remove the trailing \r\n\r\n so the string is NUL terminated */
 791         d[idx].buf[d[idx].len - 4] = '\0';
 792
 793         ret = handle_http_tcp (context, config, &d[idx]);
 794         if (ret < 0)
 795             clear_descr (d + idx);
 796     } else if (d[idx].len > 4) {
 797         kdc_log (context, config,
 798                  0, "TCP data of strange type from %s to %s/%d",
 799                  d[idx].addr_string, descr_type(d + idx),
 800                  ntohs(d[idx].port));
 801         if (d[idx].buf[0] & 0x80) {
 802             krb5_data reply;
 803
 804             kdc_log (context, config, 0, "TCP extension not supported");
 805
 806             ret = krb5_mk_error(context,
 807                                 KRB5KRB_ERR_FIELD_TOOLONG,
 808                                 NULL,
 809                                 NULL,
 810                                 NULL,
 811                                 NULL,
 812                                 NULL,
 813                                 NULL,
 814                                 &reply);
 815             if (ret == 0) {
 816                 send_reply(context, config, TRUE, d + idx, &reply);
 817                 krb5_data_free(&reply);
 818             }
 819         }
 820         clear_descr(d + idx);
 821         return;
 822     }
 823     if (ret < 0)
 824         return;
 825     else if (ret == 1) {
 826         do_request(context, config,
 827                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 828         clear_descr(d + idx);
 829     }
 830 }
 831
 832 #ifdef HAVE_FORK
 833 static void
 834 handle_islive(int fd)
 835 {
 836     char buf[2];
 837     int ret;
 838
 839     ret = read(fd, buf, 2);
 840     if (ret == 0)
 841         exit_flag = -1;
 842 }
 843 #endif
 844
 845 krb5_boolean
 846 realloc_descrs(struct descr **d, unsigned int *ndescr)
 847 {
 848     struct descr *tmp;
 849     size_t i;
 850
 851     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 852     if(tmp == NULL)
 853         return FALSE;
 854
 855     *d = tmp;
 856     reinit_descrs (*d, *ndescr);
 857     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 858     for(i = *ndescr; i < *ndescr + 4; i++)
 859         init_descr (*d + i);
 860
 861     *ndescr += 4;
 862
 863     return TRUE;
 864 }
 865
 866 int
 867 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 868 {
 869     size_t i;
 870     int min_free;
 871
 872     for(i = 0; i < *ndescr; i++) {
 873         int s = (*d + i)->s;
 874         if(rk_IS_BAD_SOCKET(s))
 875             return i;
 876     }
 877
 878     min_free = *ndescr;
 879     if(!realloc_descrs(d, ndescr)) {
 880         min_free = -1;
 881         krb5_warnx(context, "No memory");
 882     }
 883
 884     return min_free;
 885 }
 886
 887 static void
 888 loop(krb5_context context, krb5_kdc_configuration *config,
 889      struct descr *d, unsigned int ndescr, int islive)
 890 {
 891
 892     while (exit_flag == 0) {
 893         struct timeval tmout;
 894         fd_set fds;
 895         int min_free = -1;
 896         int max_fd = 0;
 897         size_t i;
 898
 899         FD_ZERO(&fds);
 900         if (islive > -1) {
 901             FD_SET(islive, &fds);
 902             max_fd = islive;
 903         }
 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 #ifdef HAVE_FORK
 937             if (islive > -1 && FD_ISSET(islive, &fds))
 938                 handle_islive(islive);
 939 #endif
 940             for (i = 0; i < ndescr; i++)
 941                 if (!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 942                     min_free = next_min_free(context, &d, &ndescr);
 943
 944                     if (d[i].type == SOCK_DGRAM)
 945                         handle_udp(context, config, &d[i]);
 946                     else if (d[i].type == SOCK_STREAM)
 947                         handle_tcp(context, config, d, i, min_free);
 948                 }
 949         }
 950     }
 951
 952     switch (exit_flag) {
 953     case -1:
 954         kdc_log(context, config, 0,
 955                 "KDC worker process exiting because KDC master exited.");
 956         break;
 957 #ifdef SIGXCPU
 958     case SIGXCPU:
 959         kdc_log(context, config, 0, "CPU time limit exceeded");
 960         break;
 961 #endif
 962     case SIGINT:
 963     case SIGTERM:
 964         kdc_log(context, config, 0, "Terminated");
 965         break;
 966     default:
 967         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
 968         break;
 969     }
 970 }
 971
 972 #ifdef __APPLE__
 973 static void
 974 bonjour_kid(krb5_context context, krb5_kdc_configuration *config, int islive)
 975 {
 976     char buf[2];
 977
 978     if (fork())
 979         return;
 980     bonjour_announce(context, config);
 981
 982     while (read(islive, buf, 1) != 0)
 983         ;
 984     exit(0);
 985 }
 986 #endif
 987
 988 #ifdef HAVE_FORK
 989 static void
 990 kill_kids(pid_t *pids, int max_kids, int sig)
 991 {
 992     int i;
 993
 994     for (i=0; i < max_kids; i++)
 995         if (pids[i] > 0)
 996             kill(sig, pids[i]);
 997 }
 998
 999 static int
1000 reap_kid(krb5_context context, krb5_kdc_configuration *config,
1001          pid_t *pids, int max_kids, int options)
1002 {
1003     pid_t pid;
1004     int status;
1005     int i;
1006
1007     pid = waitpid(-1, &status, options);
1008     if (pid < 1)
1009         return 0;
1010
1011     for (i=0; i < max_kids; i++) {
1012         if (pids[i] == pid)
1013             break;
1014     }
1015
1016     if (i == max_kids) {
1017         /* XXXrcd: this should not happen, have to do something, though */
1018         return 0;
1019     }
1020
1021     /* XXXrcd: should likely log exit code and the like */
1022     kdc_log(context, config, 0, "KDC worker process reaped: %d", pid);
1023     pids[i] = (pid_t)-1;
1024
1025     return 1;
1026 }
1027
1028 static int
1029 reap_kids(krb5_context context, krb5_kdc_configuration *config,
1030           pid_t *pids, int max_kids)
1031 {
1032     int reaped = 0;
1033
1034     for (;;) {
1035         if (reap_kid(context, config, pids, max_kids, WNOHANG) == 0)
1036             break;
1037         reaped++;
1038     }
1039
1040     return reaped;
1041 }
1042
1043 static void
1044 select_sleep(int microseconds)
1045 {
1046     struct timeval tv;
1047
1048     tv.tv_sec = microseconds / 1000000;
1049     tv.tv_usec = microseconds % 1000000;
1050     select(0, NULL, NULL, NULL, &tv);
1051 }
1052 #endif
1053
1054 void
1055 start_kdc(krb5_context context,
1056           krb5_kdc_configuration *config)
1057 {
1058     struct timeval tv1;
1059     struct timeval tv2;
1060     struct descr *d;
1061     unsigned int ndescr;
1062     pid_t pid;
1063 #ifdef HAVE_FORK
1064     pid_t *pids;
1065     int max_kdcs = config->num_kdc_processes;
1066     int num_kdcs = 0;
1067     int i;
1068     int islive[2];
1069 #endif
1070
1071 #ifdef HAVE_FORK
1072 #ifdef _SC_NPROCESSORS_ONLN
1073     if (max_kdcs < 1)
1074         max_kdcs = sysconf(_SC_NPROCESSORS_ONLN);
1075 #endif
1076
1077     if (max_kdcs < 1)
1078         max_kdcs = 1;
1079
1080     pids = malloc(max_kdcs * sizeof(*pids));
1081     if (!pids)
1082         krb5_err(context, 1, errno, "malloc");
1083     memset(pids, 0x0, max_kdcs * sizeof(*pids));
1084
1085     /*
1086      * We open a socketpair of which we hand one end to each of our kids.
1087      * When we exit, for whatever reason, the children will notice an EOF
1088      * on their end and be able to cleanly exit.
1089      */
1090
1091     if (socketpair(PF_LOCAL, SOCK_STREAM, 0, islive) == -1)
1092         krb5_errx(context, 1, "socketpair");
1093     socket_set_nonblocking(islive[1], 1);
1094 #endif
1095
1096     ndescr = init_sockets(context, config, &d);
1097     if(ndescr <= 0)
1098         krb5_errx(context, 1, "No sockets!");
1099
1100 #ifdef HAVE_FORK
1101
1102 #ifdef __APPLE__
1103     bonjour_kid(context, config, islive[1]); /* fork()s */
1104 #endif
1105
1106     kdc_log(context, config, 0, "KDC started master process pid=%d", getpid());
1107 #else
1108     kdc_log(context, config, 0, "KDC started pid=%d", getpid());
1109 #endif
1110
1111     roken_detach_finish(NULL, daemon_child);
1112
1113     tv1.tv_sec  = 0;
1114     tv1.tv_usec = 0;
1115
1116 #ifdef HAVE_FORK
1117     while (exit_flag == 0) {
1118
1119         /* Slow down the creation of KDCs... */
1120
1121         gettimeofday(&tv2, NULL);
1122         if (tv1.tv_sec == tv2.tv_sec && tv2.tv_usec - tv1.tv_usec < 25000) {
1123 #if 0   /* XXXrcd: should print a message... */
1124             kdc_log(context, config, 0, "Spawning KDCs too quickly, "
1125                 "pausing for 50ms");
1126 #endif
1127             select_sleep(12500);
1128             continue;
1129         }
1130
1131         if (num_kdcs >= max_kdcs) {
1132             num_kdcs -= reap_kid(context, config, pids, max_kdcs, 0);
1133             continue;
1134         }
1135
1136         if (num_kdcs > 0)
1137             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1138
1139         pid = fork();
1140         switch (pid) {
1141         case 0:
1142             close(islive[0]);
1143             loop(context, config, d, ndescr, islive[1]);
1144             exit(0);
1145         case -1:
1146             /* XXXrcd: hmmm, do something useful?? */
1147             kdc_log(context, config, 0,
1148                     "KDC master process could not fork worker process");
1149             sleep(10);
1150             break;
1151         default:
1152             for (i=0; i < max_kdcs; i++)
1153                 if (pids[i] == 0)
1154                     break;
1155             pids[i] = pid;
1156             kdc_log(context, config, 0, "KDC worker process started: %d", pid);
1157             num_kdcs++;
1158             gettimeofday(&tv1, NULL);
1159             break;
1160         }
1161     }
1162
1163     /* Closing these sockets should cause the kids to die... */
1164
1165     close(islive[0]);
1166     close(islive[1]);
1167
1168     gettimeofday(&tv1, NULL);
1169
1170     for (;;) {
1171         num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1172         if (num_kdcs == 0)
1173             break;
1174         /*
1175          * Using select to sleep will fail with EINTR if we receive a
1176          * SIGCHLD.  This is desirable.
1177          */
1178         select_sleep(200000);
1179         kill_kids(pids, max_kdcs, SIGTERM);
1180         gettimeofday(&tv2, NULL);
1181         if (tv2.tv_sec - tv1.tv_sec > 10)
1182             break;
1183     }
1184
1185     for (;;) {
1186         kill_kids(pids, max_kdcs, SIGKILL);
1187         num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1188         if (num_kdcs == 0)
1189             break;
1190         select_sleep(200000);
1191         gettimeofday(&tv2, NULL);
1192         if (tv2.tv_sec - tv1.tv_sec > 15)
1193             break;
1194     }
1195
1196     kdc_log(context, config, 0, "KDC master process exiting", pid);
1197     free(pids);
1198 #else
1199     loop(context, config, d, ndescr, -1);
1200     kdc_log(context, config, 0, "KDC exiting", pid);
1201 #endif
1202
1203     free (d);
1204 }