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 static pid_t bonjour_pid = -1;
  51
  52 /*
  53  * add `family, port, protocol' to the list with duplicate suppresion.
  54  */
  55
  56 static void
  57 add_port(krb5_context context,
  58          int family, int port, const char *protocol)
  59 {
  60     int type;
  61     size_t i;
  62
  63     if(strcmp(protocol, "udp") == 0)
  64         type = SOCK_DGRAM;
  65     else if(strcmp(protocol, "tcp") == 0)
  66         type = SOCK_STREAM;
  67     else
  68         return;
  69     for(i = 0; i < num_ports; i++){
  70         if(ports[i].type == type
  71            && ports[i].port == port
  72            && ports[i].family == family)
  73             return;
  74     }
  75     ports = realloc(ports, (num_ports + 1) * sizeof(*ports));
  76     if (ports == NULL)
  77         krb5_err (context, 1, errno, "realloc");
  78     ports[num_ports].family = family;
  79     ports[num_ports].type   = type;
  80     ports[num_ports].port   = port;
  81     num_ports++;
  82 }
  83
  84 /*
  85  * add a triple but with service -> port lookup
  86  * (this prints warnings for stuff that does not exist)
  87  */
  88
  89 static void
  90 add_port_service(krb5_context context,
  91                  int family, const char *service, int port,
  92                  const char *protocol)
  93 {
  94     port = krb5_getportbyname (context, service, protocol, port);
  95     add_port (context, family, port, protocol);
  96 }
  97
  98 /*
  99  * add the port with service -> port lookup or string -> number
 100  * (no warning is printed)
 101  */
 102
 103 static void
 104 add_port_string (krb5_context context,
 105                  int family, const char *str, const char *protocol)
 106 {
 107     struct servent *sp;
 108     int port;
 109
 110     sp = roken_getservbyname (str, protocol);
 111     if (sp != NULL) {
 112         port = sp->s_port;
 113     } else {
 114         char *end;
 115
 116         port = htons(strtol(str, &end, 0));
 117         if (end == str)
 118             return;
 119     }
 120     add_port (context, family, port, protocol);
 121 }
 122
 123 /*
 124  * add the standard collection of ports for `family'
 125  */
 126
 127 static void
 128 add_standard_ports (krb5_context context,
 129                     krb5_kdc_configuration *config,
 130                     int family)
 131 {
 132     add_port_service(context, family, "kerberos", 88, "udp");
 133     add_port_service(context, family, "kerberos", 88, "tcp");
 134     add_port_service(context, family, "kerberos-sec", 88, "udp");
 135     add_port_service(context, family, "kerberos-sec", 88, "tcp");
 136     if(enable_http)
 137         add_port_service(context, family, "http", 80, "tcp");
 138     if(config->enable_kx509) {
 139         add_port_service(context, family, "kca_service", 9878, "udp");
 140         add_port_service(context, family, "kca_service", 9878, "tcp");
 141     }
 142
 143 }
 144
 145 /*
 146  * parse the set of space-delimited ports in `str' and add them.
 147  * "+" => all the standard ones
 148  * otherwise it's port|service[/protocol]
 149  */
 150
 151 static void
 152 parse_ports(krb5_context context,
 153             krb5_kdc_configuration *config,
 154             const char *str)
 155 {
 156     char *pos = NULL;
 157     char *p;
 158     char *str_copy = strdup (str);
 159
 160     p = strtok_r(str_copy, " \t", &pos);
 161     while(p != NULL) {
 162         if(strcmp(p, "+") == 0) {
 163 #ifdef HAVE_IPV6
 164             add_standard_ports(context, config, AF_INET6);
 165 #endif
 166             add_standard_ports(context, config, AF_INET);
 167         } else {
 168             char *q = strchr(p, '/');
 169             if(q){
 170                 *q++ = 0;
 171 #ifdef HAVE_IPV6
 172                 add_port_string(context, AF_INET6, p, q);
 173 #endif
 174                 add_port_string(context, AF_INET, p, q);
 175             }else {
 176 #ifdef HAVE_IPV6
 177                 add_port_string(context, AF_INET6, p, "udp");
 178                 add_port_string(context, AF_INET6, p, "tcp");
 179 #endif
 180                 add_port_string(context, AF_INET, p, "udp");
 181                 add_port_string(context, AF_INET, p, "tcp");
 182             }
 183         }
 184
 185         p = strtok_r(NULL, " \t", &pos);
 186     }
 187     free (str_copy);
 188 }
 189
 190 /*
 191  * every socket we listen on
 192  */
 193
 194 struct descr {
 195     krb5_socket_t s;
 196     int type;
 197     int port;
 198     unsigned char *buf;
 199     size_t size;
 200     size_t len;
 201     time_t timeout;
 202     struct sockaddr_storage __ss;
 203     struct sockaddr *sa;
 204     socklen_t sock_len;
 205     char addr_string[128];
 206 };
 207
 208 static void
 209 init_descr(struct descr *d)
 210 {
 211     memset(d, 0, sizeof(*d));
 212     d->sa = (struct sockaddr *)&d->__ss;
 213     d->s = rk_INVALID_SOCKET;
 214 }
 215
 216 /*
 217  * re-initialize all `n' ->sa in `d'.
 218  */
 219
 220 static void
 221 reinit_descrs (struct descr *d, int n)
 222 {
 223     int i;
 224
 225     for (i = 0; i < n; ++i)
 226         d[i].sa = (struct sockaddr *)&d[i].__ss;
 227 }
 228
 229 /*
 230  * Create the socket (family, type, port) in `d'
 231  */
 232
 233 static void
 234 init_socket(krb5_context context,
 235             krb5_kdc_configuration *config,
 236             struct descr *d, krb5_address *a, int family, int type, int port)
 237 {
 238     krb5_error_code ret;
 239     struct sockaddr_storage __ss;
 240     struct sockaddr *sa = (struct sockaddr *)&__ss;
 241     krb5_socklen_t sa_size = sizeof(__ss);
 242
 243     init_descr (d);
 244
 245     ret = krb5_addr2sockaddr (context, a, sa, &sa_size, port);
 246     if (ret) {
 247         krb5_warn(context, ret, "krb5_addr2sockaddr");
 248         rk_closesocket(d->s);
 249         d->s = rk_INVALID_SOCKET;
 250         return;
 251     }
 252
 253     if (sa->sa_family != family)
 254         return;
 255
 256     d->s = socket(family, type, 0);
 257     if(rk_IS_BAD_SOCKET(d->s)){
 258         krb5_warn(context, errno, "socket(%d, %d, 0)", family, type);
 259         d->s = rk_INVALID_SOCKET;
 260         return;
 261     }
 262     rk_cloexec(d->s);
 263 #if defined(HAVE_SETSOCKOPT) && defined(SOL_SOCKET) && defined(SO_REUSEADDR)
 264     {
 265         int one = 1;
 266         setsockopt(d->s, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
 267     }
 268 #endif
 269     d->type = type;
 270     d->port = port;
 271
 272     socket_set_nonblocking(d->s, 1);
 273
 274     if(rk_IS_SOCKET_ERROR(bind(d->s, sa, sa_size))){
 275         char a_str[256];
 276         size_t len;
 277
 278         krb5_print_address (a, a_str, sizeof(a_str), &len);
 279         krb5_warn(context, errno, "bind %s/%d", a_str, ntohs(port));
 280         rk_closesocket(d->s);
 281         d->s = rk_INVALID_SOCKET;
 282         return;
 283     }
 284     if(type == SOCK_STREAM && rk_IS_SOCKET_ERROR(listen(d->s, SOMAXCONN))){
 285         char a_str[256];
 286         size_t len;
 287
 288         krb5_print_address (a, a_str, sizeof(a_str), &len);
 289         krb5_warn(context, errno, "listen %s/%d", a_str, ntohs(port));
 290         rk_closesocket(d->s);
 291         d->s = rk_INVALID_SOCKET;
 292         return;
 293     }
 294 }
 295
 296 /*
 297  * Allocate descriptors for all the sockets that we should listen on
 298  * and return the number of them.
 299  */
 300
 301 static int
 302 init_sockets(krb5_context context,
 303              krb5_kdc_configuration *config,
 304              struct descr **desc)
 305 {
 306     krb5_error_code ret;
 307     size_t i, j;
 308     struct descr *d;
 309     int num = 0;
 310     krb5_addresses addresses;
 311
 312     if (explicit_addresses.len) {
 313         addresses = explicit_addresses;
 314     } else {
 315         ret = krb5_get_all_server_addrs (context, &addresses);
 316         if (ret)
 317             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 318     }
 319     parse_ports(context, config, port_str);
 320     d = malloc(addresses.len * num_ports * sizeof(*d));
 321     if (d == NULL)
 322         krb5_errx(context, 1, "malloc(%lu) failed",
 323                   (unsigned long)num_ports * sizeof(*d));
 324
 325     for (i = 0; i < num_ports; i++){
 326         for (j = 0; j < addresses.len; ++j) {
 327             init_socket(context, config, &d[num], &addresses.val[j],
 328                         ports[i].family, ports[i].type, ports[i].port);
 329             if(d[num].s != rk_INVALID_SOCKET){
 330                 char a_str[80];
 331                 size_t len;
 332
 333                 krb5_print_address (&addresses.val[j], a_str,
 334                                     sizeof(a_str), &len);
 335
 336                 kdc_log(context, config, 5, "listening on %s port %u/%s",
 337                         a_str,
 338                         ntohs(ports[i].port),
 339                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 340                 /* XXX */
 341                 num++;
 342             }
 343         }
 344     }
 345     krb5_free_addresses (context, &addresses);
 346     d = realloc(d, num * sizeof(*d));
 347     if (d == NULL && num != 0)
 348         krb5_errx(context, 1, "realloc(%lu) failed",
 349                   (unsigned long)num * sizeof(*d));
 350     reinit_descrs (d, num);
 351     *desc = d;
 352     return num;
 353 }
 354
 355 /*
 356  *
 357  */
 358
 359 static const char *
 360 descr_type(struct descr *d)
 361 {
 362     if (d->type == SOCK_DGRAM)
 363         return "udp";
 364     else if (d->type == SOCK_STREAM)
 365         return "tcp";
 366     return "unknown";
 367 }
 368
 369 static void
 370 addr_to_string(krb5_context context,
 371                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 372 {
 373     krb5_address a;
 374     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 375         if(krb5_print_address(&a, str, len, &len) == 0) {
 376             krb5_free_address(context, &a);
 377             return;
 378         }
 379         krb5_free_address(context, &a);
 380     }
 381     snprintf(str, len, "<family=%d>", addr->sa_family);
 382 }
 383
 384 /*
 385  *
 386  */
 387
 388 static void
 389 send_reply(krb5_context context,
 390            krb5_kdc_configuration *config,
 391            krb5_boolean prependlength,
 392            struct descr *d,
 393            krb5_data *reply)
 394 {
 395     kdc_log(context, config, 5,
 396             "sending %lu bytes to %s", (unsigned long)reply->length,
 397             d->addr_string);
 398     if(prependlength){
 399         unsigned char l[4];
 400         l[0] = (reply->length >> 24) & 0xff;
 401         l[1] = (reply->length >> 16) & 0xff;
 402         l[2] = (reply->length >> 8) & 0xff;
 403         l[3] = reply->length & 0xff;
 404         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 405             kdc_log (context, config,
 406                      0, "sendto(%s): %s", d->addr_string,
 407                      strerror(rk_SOCK_ERRNO));
 408             return;
 409         }
 410     }
 411     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 412         kdc_log (context, config, 0, "sendto(%s): %s", d->addr_string,
 413                  strerror(rk_SOCK_ERRNO));
 414         return;
 415     }
 416 }
 417
 418 /*
 419  * Handle the request in `buf, len' to socket `d'
 420  */
 421
 422 static void
 423 do_request(krb5_context context,
 424            krb5_kdc_configuration *config,
 425            void *buf, size_t len, krb5_boolean prependlength,
 426            struct descr *d)
 427 {
 428     krb5_error_code ret;
 429     krb5_data reply;
 430     int datagram_reply = (d->type == SOCK_DGRAM);
 431
 432     krb5_kdc_update_time(NULL);
 433
 434     krb5_data_zero(&reply);
 435     ret = krb5_kdc_process_request(context, config,
 436                                    buf, len, &reply, &prependlength,
 437                                    d->addr_string, d->sa,
 438                                    datagram_reply);
 439     if(request_log)
 440         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 441     if(reply.length){
 442         send_reply(context, config, prependlength, d, &reply);
 443         krb5_data_free(&reply);
 444     }
 445     if(ret)
 446         kdc_log(context, config, 0,
 447                 "Failed processing %lu byte request from %s",
 448                 (unsigned long)len, d->addr_string);
 449 }
 450
 451 /*
 452  * Handle incoming data to the UDP socket in `d'
 453  */
 454
 455 static void
 456 handle_udp(krb5_context context,
 457            krb5_kdc_configuration *config,
 458            struct descr *d)
 459 {
 460     unsigned char *buf;
 461     ssize_t n;
 462
 463     buf = malloc(max_request_udp);
 464     if (buf == NULL){
 465         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 466                 (unsigned long)max_request_udp);
 467         return;
 468     }
 469
 470     d->sock_len = sizeof(d->__ss);
 471     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 472     if (rk_IS_SOCKET_ERROR(n)) {
 473         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 474             krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 475     } else {
 476         addr_to_string (context, d->sa, d->sock_len,
 477                         d->addr_string, sizeof(d->addr_string));
 478         if ((size_t)n == max_request_udp) {
 479             krb5_data data;
 480             krb5_warn(context, errno,
 481                       "recvfrom: truncated packet from %s, asking for TCP",
 482                       d->addr_string);
 483             krb5_mk_error(context,
 484                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 485                           NULL,
 486                           NULL,
 487                           NULL,
 488                           NULL,
 489                           NULL,
 490                           NULL,
 491                           &data);
 492             send_reply(context, config, FALSE, d, &data);
 493             krb5_data_free(&data);
 494         } else {
 495             do_request(context, config, buf, n, FALSE, d);
 496         }
 497     }
 498     free (buf);
 499 }
 500
 501 static void
 502 clear_descr(struct descr *d)
 503 {
 504     if(d->buf)
 505         memset(d->buf, 0, d->size);
 506     d->len = 0;
 507     if(d->s != rk_INVALID_SOCKET)
 508         rk_closesocket(d->s);
 509     d->s = rk_INVALID_SOCKET;
 510 }
 511
 512
 513 /* remove HTTP %-quoting from buf */
 514 static int
 515 de_http(char *buf)
 516 {
 517     unsigned char *p, *q;
 518     for(p = q = (unsigned char *)buf; *p; p++, q++) {
 519         if(*p == '%' && isxdigit(p[1]) && isxdigit(p[2])) {
 520             unsigned int x;
 521             if(sscanf((char *)p + 1, "%2x", &x) != 1)
 522                 return -1;
 523             *q = x;
 524             p += 2;
 525         } else
 526             *q = *p;
 527     }
 528     *q = '\0';
 529     return 0;
 530 }
 531
 532 #define TCP_TIMEOUT 4
 533
 534 /*
 535  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 536  */
 537
 538 static void
 539 add_new_tcp (krb5_context context,
 540              krb5_kdc_configuration *config,
 541              struct descr *d, int parent, int child)
 542 {
 543     krb5_socket_t s;
 544
 545     if (child == -1)
 546         return;
 547
 548     d[child].sock_len = sizeof(d[child].__ss);
 549     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 550     if(rk_IS_BAD_SOCKET(s)) {
 551         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 552             krb5_warn(context, rk_SOCK_ERRNO, "accept");
 553         return;
 554     }
 555
 556 #ifdef FD_SETSIZE
 557     if (s >= FD_SETSIZE) {
 558         krb5_warnx(context, "socket FD too large");
 559         rk_closesocket (s);
 560         return;
 561     }
 562 #endif
 563
 564     d[child].s = s;
 565     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 566     d[child].type = SOCK_STREAM;
 567     addr_to_string (context,
 568                     d[child].sa, d[child].sock_len,
 569                     d[child].addr_string, sizeof(d[child].addr_string));
 570 }
 571
 572 /*
 573  * Grow `d' to handle at least `n'.
 574  * Return != 0 if fails
 575  */
 576
 577 static int
 578 grow_descr (krb5_context context,
 579             krb5_kdc_configuration *config,
 580             struct descr *d, size_t n)
 581 {
 582     if (d->size - d->len < n) {
 583         unsigned char *tmp;
 584         size_t grow;
 585
 586         grow = max(1024, d->len + n);
 587         if (d->size + grow > max_request_tcp) {
 588             kdc_log(context, config, 0, "Request exceeds max request size (%lu bytes).",
 589                     (unsigned long)d->size + grow);
 590             clear_descr(d);
 591             return -1;
 592         }
 593         tmp = realloc (d->buf, d->size + grow);
 594         if (tmp == NULL) {
 595             kdc_log(context, config, 0, "Failed to re-allocate %lu bytes.",
 596                     (unsigned long)d->size + grow);
 597             clear_descr(d);
 598             return -1;
 599         }
 600         d->size += grow;
 601         d->buf = tmp;
 602     }
 603     return 0;
 604 }
 605
 606 /*
 607  * Try to handle the TCP data at `d->buf, d->len'.
 608  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 609  */
 610
 611 static int
 612 handle_vanilla_tcp (krb5_context context,
 613                     krb5_kdc_configuration *config,
 614                     struct descr *d)
 615 {
 616     krb5_storage *sp;
 617     uint32_t len;
 618
 619     sp = krb5_storage_from_mem(d->buf, d->len);
 620     if (sp == NULL) {
 621         kdc_log (context, config, 0, "krb5_storage_from_mem failed");
 622         return -1;
 623     }
 624     krb5_ret_uint32(sp, &len);
 625     krb5_storage_free(sp);
 626     if(d->len - 4 >= len) {
 627         memmove(d->buf, d->buf + 4, d->len - 4);
 628         d->len -= 4;
 629         return 1;
 630     }
 631     return 0;
 632 }
 633
 634 /*
 635  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 636  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 637  */
 638
 639 static int
 640 handle_http_tcp (krb5_context context,
 641                  krb5_kdc_configuration *config,
 642                  struct descr *d)
 643 {
 644     char *s, *p, *t;
 645     void *data;
 646     char *proto;
 647     int len;
 648
 649     s = (char *)d->buf;
 650
 651     /* If its a multi line query, truncate off the first line */
 652     p = strstr(s, "\r\n");
 653     if (p)
 654         *p = 0;
 655
 656     p = NULL;
 657     t = strtok_r(s, " \t", &p);
 658     if (t == NULL) {
 659         kdc_log(context, config, 0,
 660                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 661         return -1;
 662     }
 663
 664     t = strtok_r(NULL, " \t", &p);
 665     if(t == NULL) {
 666         kdc_log(context, config, 0,
 667                 "Missing HTTP GET data in request from %s", d->addr_string);
 668         return -1;
 669     }
 670
 671     data = malloc(strlen(t));
 672     if (data == NULL) {
 673         kdc_log(context, config, 0, "Failed to allocate %lu bytes",
 674                 (unsigned long)strlen(t));
 675         return -1;
 676     }
 677     if(*t == '/')
 678         t++;
 679     if(de_http(t) != 0) {
 680         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 681         kdc_log(context, config, 5, "HTTP request: %s", t);
 682         free(data);
 683         return -1;
 684     }
 685     proto = strtok_r(NULL, " \t", &p);
 686     if (proto == NULL) {
 687         kdc_log(context, config, 0, "Malformed HTTP request from %s", d->addr_string);
 688         free(data);
 689         return -1;
 690     }
 691     len = rk_base64_decode(t, data);
 692     if(len <= 0){
 693         const char *msg =
 694             " 404 Not found\r\n"
 695             "Server: Heimdal/" VERSION "\r\n"
 696             "Cache-Control: no-cache\r\n"
 697             "Pragma: no-cache\r\n"
 698             "Content-type: text/html\r\n"
 699             "Content-transfer-encoding: 8bit\r\n\r\n"
 700             "<TITLE>404 Not found</TITLE>\r\n"
 701             "<H1>404 Not found</H1>\r\n"
 702             "That page doesn't exist, maybe you are looking for "
 703             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 704         kdc_log(context, config, 0, "HTTP request from %s is non KDC request", d->addr_string);
 705         kdc_log(context, config, 5, "HTTP request: %s", t);
 706         free(data);
 707         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 708             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 709                     d->addr_string, strerror(rk_SOCK_ERRNO));
 710             return -1;
 711         }
 712         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 713             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 714                     d->addr_string, strerror(rk_SOCK_ERRNO));
 715             return -1;
 716         }
 717         return -1;
 718     }
 719     {
 720         const char *msg =
 721             " 200 OK\r\n"
 722             "Server: Heimdal/" VERSION "\r\n"
 723             "Cache-Control: no-cache\r\n"
 724             "Pragma: no-cache\r\n"
 725             "Content-type: application/octet-stream\r\n"
 726             "Content-transfer-encoding: binary\r\n\r\n";
 727         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 728             free(data);
 729             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 730                     d->addr_string, strerror(rk_SOCK_ERRNO));
 731             return -1;
 732         }
 733         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 734             free(data);
 735             kdc_log(context, config, 0, "HTTP write failed: %s: %s",
 736                     d->addr_string, strerror(rk_SOCK_ERRNO));
 737             return -1;
 738         }
 739     }
 740     if ((size_t)len > d->len)
 741         len = d->len;
 742     memcpy(d->buf, data, len);
 743     d->len = len;
 744     free(data);
 745     return 1;
 746 }
 747
 748 /*
 749  * Handle incoming data to the TCP socket in `d[index]'
 750  */
 751
 752 static void
 753 handle_tcp(krb5_context context,
 754            krb5_kdc_configuration *config,
 755            struct descr *d, int idx, int min_free)
 756 {
 757     unsigned char buf[1024];
 758     int n;
 759     int ret = 0;
 760
 761     if (d[idx].timeout == 0) {
 762         add_new_tcp (context, config, d, idx, min_free);
 763         return;
 764     }
 765
 766     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 767     if(rk_IS_SOCKET_ERROR(n)){
 768         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 769                   d[idx].addr_string, descr_type(d + idx),
 770                   ntohs(d[idx].port));
 771         return;
 772     } else if (n == 0) {
 773         krb5_warnx(context, "connection closed before end of data after %lu "
 774                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 775                    d[idx].addr_string, descr_type(d + idx),
 776                    ntohs(d[idx].port));
 777         clear_descr (d + idx);
 778         return;
 779     }
 780     if (grow_descr (context, config, &d[idx], n))
 781         return;
 782     memcpy(d[idx].buf + d[idx].len, buf, n);
 783     d[idx].len += n;
 784     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 785         ret = handle_vanilla_tcp (context, config, &d[idx]);
 786     } else if(enable_http &&
 787               d[idx].len >= 4 &&
 788               strncmp((char *)d[idx].buf, "GET ", 4) == 0 &&
 789               strncmp((char *)d[idx].buf + d[idx].len - 4,
 790                       "\r\n\r\n", 4) == 0) {
 791
 792         /* remove the trailing \r\n\r\n so the string is NUL terminated */
 793         d[idx].buf[d[idx].len - 4] = '\0';
 794
 795         ret = handle_http_tcp (context, config, &d[idx]);
 796         if (ret < 0)
 797             clear_descr (d + idx);
 798     } else if (d[idx].len > 4) {
 799         kdc_log (context, config,
 800                  0, "TCP data of strange type from %s to %s/%d",
 801                  d[idx].addr_string, descr_type(d + idx),
 802                  ntohs(d[idx].port));
 803         if (d[idx].buf[0] & 0x80) {
 804             krb5_data reply;
 805
 806             kdc_log (context, config, 0, "TCP extension not supported");
 807
 808             ret = krb5_mk_error(context,
 809                                 KRB5KRB_ERR_FIELD_TOOLONG,
 810                                 NULL,
 811                                 NULL,
 812                                 NULL,
 813                                 NULL,
 814                                 NULL,
 815                                 NULL,
 816                                 &reply);
 817             if (ret == 0) {
 818                 send_reply(context, config, TRUE, d + idx, &reply);
 819                 krb5_data_free(&reply);
 820             }
 821         }
 822         clear_descr(d + idx);
 823         return;
 824     }
 825     if (ret < 0)
 826         return;
 827     else if (ret == 1) {
 828         do_request(context, config,
 829                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 830         clear_descr(d + idx);
 831     }
 832 }
 833
 834 #ifdef HAVE_FORK
 835 static void
 836 handle_islive(int fd)
 837 {
 838     char buf;
 839     int ret;
 840
 841     ret = read(fd, &buf, 1);
 842     if (ret != 1)
 843         exit_flag = -1;
 844 }
 845 #endif
 846
 847 krb5_boolean
 848 realloc_descrs(struct descr **d, unsigned int *ndescr)
 849 {
 850     struct descr *tmp;
 851     size_t i;
 852
 853     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 854     if(tmp == NULL)
 855         return FALSE;
 856
 857     *d = tmp;
 858     reinit_descrs (*d, *ndescr);
 859     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 860     for(i = *ndescr; i < *ndescr + 4; i++)
 861         init_descr (*d + i);
 862
 863     *ndescr += 4;
 864
 865     return TRUE;
 866 }
 867
 868 int
 869 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 870 {
 871     size_t i;
 872     int min_free;
 873
 874     for(i = 0; i < *ndescr; i++) {
 875         int s = (*d + i)->s;
 876         if(rk_IS_BAD_SOCKET(s))
 877             return i;
 878     }
 879
 880     min_free = *ndescr;
 881     if(!realloc_descrs(d, ndescr)) {
 882         min_free = -1;
 883         krb5_warnx(context, "No memory");
 884     }
 885
 886     return min_free;
 887 }
 888
 889 static void
 890 loop(krb5_context context, krb5_kdc_configuration *config,
 891      struct descr *d, unsigned int ndescr, int islive)
 892 {
 893
 894     while (exit_flag == 0) {
 895         struct timeval tmout;
 896         fd_set fds;
 897         int min_free = -1;
 898         int max_fd = 0;
 899         size_t i;
 900
 901         FD_ZERO(&fds);
 902         if (islive > -1) {
 903             FD_SET(islive, &fds);
 904             max_fd = islive;
 905         }
 906         for (i = 0; i < ndescr; i++) {
 907             if (!rk_IS_BAD_SOCKET(d[i].s)) {
 908                 if (d[i].type == SOCK_STREAM &&
 909                    d[i].timeout && d[i].timeout < time(NULL)) {
 910                     kdc_log(context, config, 1,
 911                             "TCP-connection from %s expired after %lu bytes",
 912                             d[i].addr_string, (unsigned long)d[i].len);
 913                     clear_descr(&d[i]);
 914                     continue;
 915                 }
 916 #ifndef NO_LIMIT_FD_SETSIZE
 917                 if (max_fd < d[i].s)
 918                     max_fd = d[i].s;
 919 #ifdef FD_SETSIZE
 920                 if (max_fd >= FD_SETSIZE)
 921                     krb5_errx(context, 1, "fd too large");
 922 #endif
 923 #endif
 924                 FD_SET(d[i].s, &fds);
 925             }
 926         }
 927
 928         tmout.tv_sec = TCP_TIMEOUT;
 929         tmout.tv_usec = 0;
 930         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 931         case 0:
 932             break;
 933         case -1:
 934             if (errno != EINTR)
 935                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 936             break;
 937         default:
 938 #ifdef HAVE_FORK
 939             if (islive > -1 && FD_ISSET(islive, &fds))
 940                 handle_islive(islive);
 941 #endif
 942             for (i = 0; i < ndescr; i++)
 943                 if (!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 944                     min_free = next_min_free(context, &d, &ndescr);
 945
 946                     if (d[i].type == SOCK_DGRAM)
 947                         handle_udp(context, config, &d[i]);
 948                     else if (d[i].type == SOCK_STREAM)
 949                         handle_tcp(context, config, d, i, min_free);
 950                 }
 951         }
 952     }
 953
 954     switch (exit_flag) {
 955     case -1:
 956         kdc_log(context, config, 0,
 957                 "KDC worker process exiting because KDC master exited.");
 958         break;
 959 #ifdef SIGXCPU
 960     case SIGXCPU:
 961         kdc_log(context, config, 0, "CPU time limit exceeded");
 962         break;
 963 #endif
 964     case SIGINT:
 965     case SIGTERM:
 966         kdc_log(context, config, 0, "Terminated");
 967         break;
 968     default:
 969         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
 970         break;
 971     }
 972 }
 973
 974 #ifdef __APPLE__
 975 static void
 976 bonjour_kid(krb5_context context, krb5_kdc_configuration *config, const char *argv0, int *islive)
 977 {
 978     char buf;
 979
 980     if (do_bonjour > 0) {
 981         bonjour_announce(context, config);
 982
 983         while (read(0, &buf, 1) == 1)
 984             continue;
 985         _exit(0);
 986     }
 987
 988     if ((bonjour_pid = fork()) != 0)
 989         return;
 990
 991     close(islive[0]);
 992     if (dup2(islive[1], 0) == -1)
 993         err(1, "failed to announce with bonjour (dup)");
 994     if (islive[1] != 0)
 995         close(islive[1]);
 996     execlp(argv0, "kdc", "--bonjour", NULL);
 997     err(1, "failed to announce with bonjour (exec)");
 998 }
 999 #endif
1000
1001 #ifdef HAVE_FORK
1002 static void
1003 kill_kids(pid_t *pids, int max_kids, int sig)
1004 {
1005     int i;
1006
1007     for (i=0; i < max_kids; i++)
1008         if (pids[i] > 0)
1009             kill(sig, pids[i]);
1010     if (bonjour_pid > 0)
1011         kill(sig, bonjour_pid);
1012 }
1013
1014 static int
1015 reap_kid(krb5_context context, krb5_kdc_configuration *config,
1016          pid_t *pids, int max_kids, int options)
1017 {
1018     pid_t pid;
1019     char *what;
1020     int status;
1021     int i;
1022
1023     pid = waitpid(-1, &status, options);
1024     if (pid < 1)
1025         return 0;
1026
1027     if (pid != bonjour_pid) {
1028         for (i=0; i < max_kids; i++) {
1029             if (pids[i] == pid)
1030                 break;
1031         }
1032
1033         if (i == max_kids) {
1034             /* XXXrcd: this should not happen, have to do something, though */
1035             return 0;
1036         }
1037     }
1038
1039     if (pid == bonjour_pid)
1040         what = "bonjour";
1041     else
1042         what = "worker";
1043     if (WIFEXITED(status))
1044         kdc_log(context, config, 0, "KDC reaped %s process: %d, exit status: %d",
1045                 what, (int)pid, WEXITSTATUS(status));
1046     else if (WIFSIGNALED(status))
1047         kdc_log(context, config, 0, "KDC reaped %s process: %d, term signal %d%s",
1048                 what, (int)pid, WTERMSIG(status),
1049                 WCOREDUMP(status) ? " (core dumped)" : "");
1050     else
1051         kdc_log(context, config, 0, "KDC reaped %s process: %d",
1052                 what, (int)pid);
1053     if (pid == bonjour_pid) {
1054         bonjour_pid = (pid_t)-1;
1055         return 0;
1056     } else {
1057         pids[i] = (pid_t)-1;
1058         return 1;
1059     }
1060 }
1061
1062 static int
1063 reap_kids(krb5_context context, krb5_kdc_configuration *config,
1064           pid_t *pids, int max_kids)
1065 {
1066     int reaped = 0;
1067
1068     for (;;) {
1069         if (reap_kid(context, config, pids, max_kids, WNOHANG) == 0)
1070             break;
1071         reaped++;
1072     }
1073
1074     return reaped;
1075 }
1076
1077 static void
1078 select_sleep(int microseconds)
1079 {
1080     struct timeval tv;
1081
1082     tv.tv_sec = microseconds / 1000000;
1083     tv.tv_usec = microseconds % 1000000;
1084     select(0, NULL, NULL, NULL, &tv);
1085 }
1086 #endif
1087
1088 void
1089 start_kdc(krb5_context context,
1090           krb5_kdc_configuration *config, const char *argv0)
1091 {
1092     struct timeval tv1;
1093     struct timeval tv2;
1094     struct descr *d;
1095     unsigned int ndescr;
1096     pid_t pid;
1097 #ifdef HAVE_FORK
1098     pid_t *pids;
1099     int max_kdcs = config->num_kdc_processes;
1100     int num_kdcs = 0;
1101     int i;
1102     int islive[2];
1103 #endif
1104
1105 #ifdef __APPLE__
1106     if (do_bonjour > 0)
1107         bonjour_kid(context, config, argv0, NULL);
1108 #endif
1109
1110 #ifdef HAVE_FORK
1111 #ifdef _SC_NPROCESSORS_ONLN
1112     if (max_kdcs < 1)
1113         max_kdcs = sysconf(_SC_NPROCESSORS_ONLN);
1114 #endif
1115
1116     if (max_kdcs < 1)
1117         max_kdcs = 1;
1118
1119     pids = malloc(max_kdcs * sizeof(*pids));
1120     if (!pids)
1121         krb5_err(context, 1, errno, "malloc");
1122     memset(pids, 0x0, max_kdcs * sizeof(*pids));
1123
1124     /*
1125      * We open a socketpair of which we hand one end to each of our kids.
1126      * When we exit, for whatever reason, the children will notice an EOF
1127      * on their end and be able to cleanly exit.
1128      */
1129
1130     if (socketpair(PF_LOCAL, SOCK_STREAM, 0, islive) == -1)
1131         krb5_errx(context, 1, "socketpair");
1132     socket_set_nonblocking(islive[1], 1);
1133 #endif
1134
1135     ndescr = init_sockets(context, config, &d);
1136     if(ndescr <= 0)
1137         krb5_errx(context, 1, "No sockets!");
1138
1139 #ifdef HAVE_FORK
1140
1141 # ifdef __APPLE__
1142     if (do_bonjour < 0)
1143         bonjour_kid(context, config, argv0, islive);
1144 # endif
1145
1146     kdc_log(context, config, 0, "KDC started master process pid=%d", getpid());
1147 #else
1148     kdc_log(context, config, 0, "KDC started pid=%d", getpid());
1149 #endif
1150
1151     roken_detach_finish(NULL, daemon_child);
1152
1153     tv1.tv_sec  = 0;
1154     tv1.tv_usec = 0;
1155
1156 #ifdef HAVE_FORK
1157     while (exit_flag == 0) {
1158
1159         /* Slow down the creation of KDCs... */
1160
1161         gettimeofday(&tv2, NULL);
1162         if (tv1.tv_sec == tv2.tv_sec && tv2.tv_usec - tv1.tv_usec < 25000) {
1163 #if 0   /* XXXrcd: should print a message... */
1164             kdc_log(context, config, 0, "Spawning KDCs too quickly, "
1165                 "pausing for 50ms");
1166 #endif
1167             select_sleep(12500);
1168             continue;
1169         }
1170
1171         if (num_kdcs >= max_kdcs) {
1172             num_kdcs -= reap_kid(context, config, pids, max_kdcs, 0);
1173             continue;
1174         }
1175
1176         if (num_kdcs > 0)
1177             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1178
1179         pid = fork();
1180         switch (pid) {
1181         case 0:
1182             close(islive[0]);
1183             loop(context, config, d, ndescr, islive[1]);
1184             exit(0);
1185         case -1:
1186             /* XXXrcd: hmmm, do something useful?? */
1187             kdc_log(context, config, 0,
1188                     "KDC master process could not fork worker process");
1189             sleep(10);
1190             break;
1191         default:
1192             for (i=0; i < max_kdcs; i++)
1193                 if (pids[i] == 0)
1194                     break;
1195             pids[i] = pid;
1196             kdc_log(context, config, 0, "KDC worker process started: %d", pid);
1197             num_kdcs++;
1198             gettimeofday(&tv1, NULL);
1199             break;
1200         }
1201     }
1202
1203     /* Closing these sockets should cause the kids to die... */
1204
1205     close(islive[0]);
1206     close(islive[1]);
1207
1208     /* Close our listener sockets before terminating workers */
1209     for (i = 0; i < ndescr; ++i)
1210         clear_descr(&d[i]);
1211
1212     gettimeofday(&tv1, NULL);
1213     tv2 = tv1;
1214
1215     /* Reap every 10ms, terminate stragglers once a second, give up after 10 */
1216     for (;;) {
1217         struct timeval tv3;
1218         num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1219         if (num_kdcs == 0 && bonjour_pid <= 0)
1220             goto end;
1221         /*
1222          * Using select to sleep will fail with EINTR if we receive a
1223          * SIGCHLD.  This is desirable.
1224          */
1225         select_sleep(10000);
1226         gettimeofday(&tv3, NULL);
1227         if (tv3.tv_sec - tv1.tv_sec > 10 ||
1228             (tv3.tv_sec - tv1.tv_sec == 10 && tv3.tv_usec >= tv1.tv_usec))
1229             break;
1230         if (tv3.tv_sec - tv2.tv_sec > 1 ||
1231             (tv3.tv_sec - tv2.tv_sec == 1 && tv3.tv_usec >= tv2.tv_usec)) {
1232             kill_kids(pids, max_kdcs, SIGTERM);
1233             tv2 = tv3;
1234         }
1235     }
1236
1237     /* Kill stragglers and reap every 200ms, give up after 15s */
1238     for (;;) {
1239         kill_kids(pids, max_kdcs, SIGKILL);
1240         num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1241         if (num_kdcs == 0 && bonjour_pid <= 0)
1242             break;
1243         select_sleep(200000);
1244         gettimeofday(&tv2, NULL);
1245         if (tv2.tv_sec - tv1.tv_sec > 15 ||
1246             (tv2.tv_sec - tv1.tv_sec == 15 && tv2.tv_usec >= tv1.tv_usec))
1247             break;
1248     }
1249
1250  end:
1251     kdc_log(context, config, 0, "KDC master process exiting", pid);
1252     free(pids);
1253 #else
1254     loop(context, config, d, ndescr, -1);
1255     kdc_log(context, config, 0, "KDC exiting", pid);
1256 #endif
1257
1258     free (d);
1259 }