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         (void) setsockopt(d->s, SOL_SOCKET, SO_REUSEADDR, (void *)&one,
 267                           sizeof(one));
 268     }
 269 #endif
 270     d->type = type;
 271     d->port = port;
 272
 273     socket_set_nonblocking(d->s, 1);
 274
 275     if(rk_IS_SOCKET_ERROR(bind(d->s, sa, sa_size))){
 276         char a_str[256];
 277         size_t len;
 278
 279         krb5_print_address (a, a_str, sizeof(a_str), &len);
 280         krb5_warn(context, errno, "bind %s/%d", a_str, ntohs(port));
 281         rk_closesocket(d->s);
 282         d->s = rk_INVALID_SOCKET;
 283         return;
 284     }
 285     if(type == SOCK_STREAM && rk_IS_SOCKET_ERROR(listen(d->s, SOMAXCONN))){
 286         char a_str[256];
 287         size_t len;
 288
 289         krb5_print_address (a, a_str, sizeof(a_str), &len);
 290         krb5_warn(context, errno, "listen %s/%d", a_str, ntohs(port));
 291         rk_closesocket(d->s);
 292         d->s = rk_INVALID_SOCKET;
 293         return;
 294     }
 295     socket_set_keepalive(d->s, 1);
 296 }
 297
 298 /*
 299  * Allocate descriptors for all the sockets that we should listen on
 300  * and return the number of them.
 301  */
 302
 303 static int
 304 init_sockets(krb5_context context,
 305              krb5_kdc_configuration *config,
 306              struct descr **desc)
 307 {
 308     krb5_error_code ret;
 309     size_t i, j;
 310     struct descr *d;
 311     int num = 0;
 312     krb5_addresses addresses;
 313
 314     if (explicit_addresses.len) {
 315         addresses = explicit_addresses;
 316     } else {
 317         ret = krb5_get_all_server_addrs (context, &addresses);
 318         if (ret)
 319             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 320     }
 321     parse_ports(context, config, port_str);
 322     d = malloc(addresses.len * num_ports * sizeof(*d));
 323     if (d == NULL)
 324         krb5_errx(context, 1, "malloc(%lu) failed",
 325                   (unsigned long)num_ports * sizeof(*d));
 326
 327     for (i = 0; i < num_ports; i++){
 328         for (j = 0; j < addresses.len; ++j) {
 329             init_socket(context, config, &d[num], &addresses.val[j],
 330                         ports[i].family, ports[i].type, ports[i].port);
 331             if(d[num].s != rk_INVALID_SOCKET){
 332                 char a_str[80];
 333                 size_t len;
 334
 335                 krb5_print_address (&addresses.val[j], a_str,
 336                                     sizeof(a_str), &len);
 337
 338                 kdc_log(context, config, 3, "listening on %s port %u/%s",
 339                         a_str,
 340                         ntohs(ports[i].port),
 341                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 342                 /* XXX */
 343                 num++;
 344             }
 345         }
 346     }
 347     krb5_free_addresses (context, &addresses);
 348     d = realloc(d, num * sizeof(*d));
 349     if (d == NULL && num != 0)
 350         krb5_errx(context, 1, "realloc(%lu) failed",
 351                   (unsigned long)num * sizeof(*d));
 352     reinit_descrs (d, num);
 353     *desc = d;
 354     return num;
 355 }
 356
 357 /*
 358  *
 359  */
 360
 361 static const char *
 362 descr_type(struct descr *d)
 363 {
 364     if (d->type == SOCK_DGRAM)
 365         return "udp";
 366     else if (d->type == SOCK_STREAM)
 367         return "tcp";
 368     return "unknown";
 369 }
 370
 371 static void
 372 addr_to_string(krb5_context context,
 373                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 374 {
 375     krb5_address a;
 376     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 377         if(krb5_print_address(&a, str, len, &len) == 0) {
 378             krb5_free_address(context, &a);
 379             return;
 380         }
 381         krb5_free_address(context, &a);
 382     }
 383     snprintf(str, len, "<family=%d>", addr->sa_family);
 384 }
 385
 386 /*
 387  *
 388  */
 389
 390 static void
 391 send_reply(krb5_context context,
 392            krb5_kdc_configuration *config,
 393            krb5_boolean prependlength,
 394            struct descr *d,
 395            krb5_data *reply)
 396 {
 397     kdc_log(context, config, 4,
 398             "sending %lu bytes to %s", (unsigned long)reply->length,
 399             d->addr_string);
 400     if(prependlength){
 401         unsigned char l[4];
 402         l[0] = (reply->length >> 24) & 0xff;
 403         l[1] = (reply->length >> 16) & 0xff;
 404         l[2] = (reply->length >> 8) & 0xff;
 405         l[3] = reply->length & 0xff;
 406         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 407             kdc_log (context, config,
 408                      1, "sendto(%s): %s", d->addr_string,
 409                      strerror(rk_SOCK_ERRNO));
 410             return;
 411         }
 412     }
 413     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 414         kdc_log (context, config, 1, "sendto(%s): %s", d->addr_string,
 415                  strerror(rk_SOCK_ERRNO));
 416         return;
 417     }
 418 }
 419
 420 /*
 421  * Handle the request in `buf, len' to socket `d'
 422  */
 423
 424 static void
 425 do_request(krb5_context context,
 426            krb5_kdc_configuration *config,
 427            void *buf, size_t len, krb5_boolean prependlength,
 428            struct descr *d)
 429 {
 430     krb5_error_code ret;
 431     krb5_data reply;
 432     int datagram_reply = (d->type == SOCK_DGRAM);
 433
 434     krb5_kdc_update_time(NULL);
 435
 436     krb5_data_zero(&reply);
 437     ret = krb5_kdc_process_request(context, config,
 438                                    buf, len, &reply, &prependlength,
 439                                    d->addr_string, d->sa,
 440                                    datagram_reply);
 441     if(request_log)
 442         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 443     if(reply.length){
 444         send_reply(context, config, prependlength, d, &reply);
 445         krb5_data_free(&reply);
 446     }
 447     if(ret)
 448         kdc_log(context, config, 1,
 449                 "Failed processing %lu byte request from %s",
 450                 (unsigned long)len, d->addr_string);
 451 }
 452
 453 /*
 454  * Handle incoming data to the UDP socket in `d'
 455  */
 456
 457 static void
 458 handle_udp(krb5_context context,
 459            krb5_kdc_configuration *config,
 460            struct descr *d)
 461 {
 462     unsigned char *buf;
 463     ssize_t n;
 464
 465     buf = malloc(max_request_udp);
 466     if (buf == NULL){
 467         kdc_log(context, config, 1, "Failed to allocate %lu bytes",
 468                 (unsigned long)max_request_udp);
 469         return;
 470     }
 471
 472     d->sock_len = sizeof(d->__ss);
 473     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 474     if (rk_IS_SOCKET_ERROR(n)) {
 475         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 476             krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 477     } else {
 478         addr_to_string (context, d->sa, d->sock_len,
 479                         d->addr_string, sizeof(d->addr_string));
 480         if ((size_t)n == max_request_udp) {
 481             krb5_data data;
 482             krb5_warn(context, errno,
 483                       "recvfrom: truncated packet from %s, asking for TCP",
 484                       d->addr_string);
 485             krb5_mk_error(context,
 486                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 487                           NULL,
 488                           NULL,
 489                           NULL,
 490                           NULL,
 491                           NULL,
 492                           NULL,
 493                           &data);
 494             send_reply(context, config, FALSE, d, &data);
 495             krb5_data_free(&data);
 496         } else {
 497             do_request(context, config, buf, n, FALSE, d);
 498         }
 499     }
 500     free (buf);
 501 }
 502
 503 static void
 504 clear_descr(struct descr *d)
 505 {
 506     if(d->buf)
 507         memset(d->buf, 0, d->size);
 508     d->len = 0;
 509     if(d->s != rk_INVALID_SOCKET)
 510         rk_closesocket(d->s);
 511     d->s = rk_INVALID_SOCKET;
 512 }
 513
 514
 515 /* remove HTTP %-quoting from buf */
 516 static int
 517 de_http(char *buf)
 518 {
 519     unsigned char *p, *q;
 520     unsigned int x;
 521
 522     for (p = q = (unsigned char *)buf; *p; p++, q++) {
 523         if (*p == '%') {
 524             if (!(isxdigit(p[1]) && isxdigit(p[2])))
 525                 return -1;
 526
 527             if (sscanf((char *)p + 1, "%2x", &x) != 1)
 528                 return -1;
 529
 530             *q = x;
 531             p += 2;
 532         } else {
 533             *q = *p;
 534         }
 535     }
 536     *q = '\0';
 537     return 0;
 538 }
 539
 540 #define TCP_TIMEOUT 4
 541
 542 /*
 543  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 544  */
 545
 546 static void
 547 add_new_tcp (krb5_context context,
 548              krb5_kdc_configuration *config,
 549              struct descr *d, int parent, int child)
 550 {
 551     krb5_socket_t s;
 552
 553     if (child == -1)
 554         return;
 555
 556     d[child].sock_len = sizeof(d[child].__ss);
 557     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 558     if(rk_IS_BAD_SOCKET(s)) {
 559         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 560             krb5_warn(context, rk_SOCK_ERRNO, "accept");
 561         return;
 562     }
 563
 564 #ifdef FD_SETSIZE
 565     if (s >= FD_SETSIZE) {
 566         krb5_warnx(context, "socket FD too large");
 567         rk_closesocket (s);
 568         return;
 569     }
 570 #endif
 571
 572     d[child].s = s;
 573     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 574     d[child].type = SOCK_STREAM;
 575     addr_to_string (context,
 576                     d[child].sa, d[child].sock_len,
 577                     d[child].addr_string, sizeof(d[child].addr_string));
 578 }
 579
 580 /*
 581  * Grow `d' to handle at least `n'.
 582  * Return != 0 if fails
 583  */
 584
 585 static int
 586 grow_descr (krb5_context context,
 587             krb5_kdc_configuration *config,
 588             struct descr *d, size_t n)
 589 {
 590     if (d->size - d->len < n) {
 591         unsigned char *tmp;
 592         size_t grow;
 593
 594         grow = max(1024, d->len + n);
 595         if (d->size + grow > max_request_tcp) {
 596             kdc_log(context, config, 2, "Request exceeds max request size (%lu bytes).",
 597                     (unsigned long)d->size + grow);
 598             clear_descr(d);
 599             return -1;
 600         }
 601         tmp = realloc (d->buf, d->size + grow);
 602         if (tmp == NULL) {
 603             kdc_log(context, config, 1, "Failed to re-allocate %lu bytes.",
 604                     (unsigned long)d->size + grow);
 605             clear_descr(d);
 606             return -1;
 607         }
 608         d->size += grow;
 609         d->buf = tmp;
 610     }
 611     return 0;
 612 }
 613
 614 /*
 615  * Try to handle the TCP data at `d->buf, d->len'.
 616  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 617  */
 618
 619 static int
 620 handle_vanilla_tcp (krb5_context context,
 621                     krb5_kdc_configuration *config,
 622                     struct descr *d)
 623 {
 624     krb5_storage *sp;
 625     uint32_t len;
 626
 627     sp = krb5_storage_from_mem(d->buf, d->len);
 628     if (sp == NULL) {
 629         kdc_log (context, config, 1, "krb5_storage_from_mem failed");
 630         return -1;
 631     }
 632     krb5_ret_uint32(sp, &len);
 633     krb5_storage_free(sp);
 634     if(d->len - 4 >= len) {
 635         memmove(d->buf, d->buf + 4, d->len - 4);
 636         d->len -= 4;
 637         return 1;
 638     }
 639     return 0;
 640 }
 641
 642 /*
 643  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 644  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 645  */
 646
 647 static int
 648 handle_http_tcp (krb5_context context,
 649                  krb5_kdc_configuration *config,
 650                  struct descr *d)
 651 {
 652     char *s, *p, *t;
 653     void *data;
 654     char *proto;
 655     int len;
 656
 657     s = (char *)d->buf;
 658
 659     /* If its a multi line query, truncate off the first line */
 660     p = strstr(s, "\r\n");
 661     if (p)
 662         *p = 0;
 663
 664     p = NULL;
 665     t = strtok_r(s, " \t", &p);
 666     if (t == NULL) {
 667         kdc_log(context, config, 2,
 668                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 669         return -1;
 670     }
 671
 672     t = strtok_r(NULL, " \t", &p);
 673     if(t == NULL) {
 674         kdc_log(context, config, 2,
 675                 "Missing HTTP GET data in request from %s", d->addr_string);
 676         return -1;
 677     }
 678
 679     data = malloc(strlen(t));
 680     if (data == NULL) {
 681         kdc_log(context, config, 1, "Failed to allocate %lu bytes",
 682                 (unsigned long)strlen(t));
 683         return -1;
 684     }
 685     if(*t == '/')
 686         t++;
 687     if(de_http(t) != 0) {
 688         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 689         kdc_log(context, config, 4, "HTTP request: %s", t);
 690         free(data);
 691         return -1;
 692     }
 693     proto = strtok_r(NULL, " \t", &p);
 694     if (proto == NULL) {
 695         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 696         free(data);
 697         return -1;
 698     }
 699     len = rk_base64_decode(t, data);
 700     if(len <= 0){
 701         const char *msg =
 702             " 404 Not found\r\n"
 703             "Server: Heimdal/" VERSION "\r\n"
 704             "Cache-Control: no-cache\r\n"
 705             "Pragma: no-cache\r\n"
 706             "Content-type: text/html\r\n"
 707             "Content-transfer-encoding: 8bit\r\n\r\n"
 708             "<TITLE>404 Not found</TITLE>\r\n"
 709             "<H1>404 Not found</H1>\r\n"
 710             "That page doesn't exist, maybe you are looking for "
 711             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 712         kdc_log(context, config, 2, "HTTP request from %s is non KDC request", d->addr_string);
 713         kdc_log(context, config, 4, "HTTP request: %s", t);
 714         free(data);
 715         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 716             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 717                     d->addr_string, strerror(rk_SOCK_ERRNO));
 718             return -1;
 719         }
 720         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 721             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 722                     d->addr_string, strerror(rk_SOCK_ERRNO));
 723             return -1;
 724         }
 725         return -1;
 726     }
 727     {
 728         const char *msg =
 729             " 200 OK\r\n"
 730             "Server: Heimdal/" VERSION "\r\n"
 731             "Cache-Control: no-cache\r\n"
 732             "Pragma: no-cache\r\n"
 733             "Content-type: application/octet-stream\r\n"
 734             "Content-transfer-encoding: binary\r\n\r\n";
 735         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 736             free(data);
 737             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 738                     d->addr_string, strerror(rk_SOCK_ERRNO));
 739             return -1;
 740         }
 741         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 742             free(data);
 743             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 744                     d->addr_string, strerror(rk_SOCK_ERRNO));
 745             return -1;
 746         }
 747     }
 748     if ((size_t)len > d->len)
 749         len = d->len;
 750     memcpy(d->buf, data, len);
 751     d->len = len;
 752     free(data);
 753     return 1;
 754 }
 755
 756 static int
 757 http1_request_taste(const unsigned char *req, size_t len)
 758 {
 759     return !!((len >= sizeof("GET ") - 1 &&
 760                memcmp(req, "GET ", sizeof("GET ") - 1) == 0) ||
 761               (len >= sizeof("HEAD ") - 1 &&
 762                memcmp(req, "HEAD ", sizeof("HEAD ") - 1) == 0));
 763 }
 764
 765 static int
 766 http1_request_is_complete(const unsigned char *req, size_t len)
 767 {
 768
 769     return http1_request_taste(req, len) &&
 770         memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 771
 772     /*
 773      * For POST (the MSFT variant of this protocol) we'll need something like
 774      * this (plus check for Content-Length/Transfer-Encoding):
 775      *
 776      *  const unsigned char *body;
 777      *  if ((body = memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4)) == NULL)
 778      *      return 0;
 779      *  body += sizeof("\r\n\r\n") - 4;
 780      *  len -= (body - req);
 781      *  return memmem(body, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 782      *
 783      * Since the POST-based variant runs over HTTPS, we'll probably implement
 784      * that in a proxy instead of here.
 785      */
 786 }
 787
 788 /*
 789  * Handle incoming data to the TCP socket in `d[index]'
 790  */
 791
 792 static void
 793 handle_tcp(krb5_context context,
 794            krb5_kdc_configuration *config,
 795            struct descr *d, int idx, int min_free)
 796 {
 797     unsigned char buf[1024];
 798     int n;
 799     int ret = 0;
 800
 801     if (d[idx].timeout == 0) {
 802         add_new_tcp (context, config, d, idx, min_free);
 803         return;
 804     }
 805
 806     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 807     if(rk_IS_SOCKET_ERROR(n)){
 808         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 809                   d[idx].addr_string, descr_type(d + idx),
 810                   ntohs(d[idx].port));
 811         return;
 812     } else if (n == 0) {
 813         krb5_warnx(context, "connection closed before end of data after %lu "
 814                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 815                    d[idx].addr_string, descr_type(d + idx),
 816                    ntohs(d[idx].port));
 817         clear_descr (d + idx);
 818         return;
 819     }
 820     if (grow_descr (context, config, &d[idx], n))
 821         return;
 822     memcpy(d[idx].buf + d[idx].len, buf, n);
 823     d[idx].len += n;
 824     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 825         ret = handle_vanilla_tcp (context, config, &d[idx]);
 826     } else if (enable_http &&
 827                http1_request_taste(d[idx].buf, d[idx].len)) {
 828
 829         if (http1_request_is_complete(d[idx].buf, d[idx].len)) {
 830             /* NUL-terminate at the request header ending \r\n\r\n */
 831             d[idx].buf[d[idx].len - 4] = '\0';
 832             ret = handle_http_tcp (context, config, &d[idx]);
 833         }
 834     } else if (d[idx].len > 4) {
 835         kdc_log (context, config,
 836                  2, "TCP data of strange type from %s to %s/%d",
 837                  d[idx].addr_string, descr_type(d + idx),
 838                  ntohs(d[idx].port));
 839         if (d[idx].buf[0] & 0x80) {
 840             krb5_data reply;
 841
 842             kdc_log (context, config, 2, "TCP extension not supported");
 843
 844             ret = krb5_mk_error(context,
 845                                 KRB5KRB_ERR_FIELD_TOOLONG,
 846                                 NULL,
 847                                 NULL,
 848                                 NULL,
 849                                 NULL,
 850                                 NULL,
 851                                 NULL,
 852                                 &reply);
 853             if (ret == 0) {
 854                 send_reply(context, config, TRUE, d + idx, &reply);
 855                 krb5_data_free(&reply);
 856             }
 857         }
 858         clear_descr(d + idx);
 859         return;
 860     }
 861
 862     /*
 863      * ret == 0 -> not enough of request buffered -> wait for more
 864      * ret == 1 -> go ahead and perform the request
 865      * ret != 0 (really, < 0) -> error, probably ENOMEM, close connection
 866      */
 867     if (ret == 1)
 868         do_request(context, config,
 869                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 870
 871     /*
 872      * Note: this means we don't keep the connection open even where we
 873      * the protocol permits it.
 874      */
 875     if (ret != 0)
 876         clear_descr(d + idx);
 877 }
 878
 879 #ifdef HAVE_FORK
 880 static void
 881 handle_islive(int fd)
 882 {
 883     char buf;
 884     int ret;
 885
 886     ret = read(fd, &buf, 1);
 887     if (ret != 1)
 888         exit_flag = -1;
 889 }
 890 #endif
 891
 892 static krb5_boolean
 893 realloc_descrs(struct descr **d, unsigned int *ndescr)
 894 {
 895     struct descr *tmp;
 896     size_t i;
 897
 898     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 899     if(tmp == NULL)
 900         return FALSE;
 901
 902     *d = tmp;
 903     reinit_descrs (*d, *ndescr);
 904     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 905     for(i = *ndescr; i < *ndescr + 4; i++)
 906         init_descr (*d + i);
 907
 908     *ndescr += 4;
 909
 910     return TRUE;
 911 }
 912
 913 static int
 914 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 915 {
 916     size_t i;
 917     int min_free;
 918
 919     for(i = 0; i < *ndescr; i++) {
 920         int s = (*d + i)->s;
 921         if(rk_IS_BAD_SOCKET(s))
 922             return i;
 923     }
 924
 925     min_free = *ndescr;
 926     if(!realloc_descrs(d, ndescr)) {
 927         min_free = -1;
 928         krb5_warnx(context, "No memory");
 929     }
 930
 931     return min_free;
 932 }
 933
 934 static void
 935 loop(krb5_context context, krb5_kdc_configuration *config,
 936      struct descr **dp, unsigned int *ndescrp, int islive)
 937 {
 938     struct descr *d = *dp;
 939     unsigned int ndescr = *ndescrp;
 940
 941     while (exit_flag == 0) {
 942         struct timeval tmout;
 943         fd_set fds;
 944         int min_free = -1;
 945         int max_fd = 0;
 946         size_t i;
 947
 948         FD_ZERO(&fds);
 949         if (islive > -1) {
 950             FD_SET(islive, &fds);
 951             max_fd = islive;
 952         }
 953         for (i = 0; i < ndescr; i++) {
 954             if (!rk_IS_BAD_SOCKET(d[i].s)) {
 955                 if (d[i].type == SOCK_STREAM &&
 956                    d[i].timeout && d[i].timeout < time(NULL)) {
 957                     kdc_log(context, config, 2,
 958                             "TCP-connection from %s expired after %lu bytes",
 959                             d[i].addr_string, (unsigned long)d[i].len);
 960                     clear_descr(&d[i]);
 961                     continue;
 962                 }
 963 #ifndef NO_LIMIT_FD_SETSIZE
 964                 if (max_fd < d[i].s)
 965                     max_fd = d[i].s;
 966 #ifdef FD_SETSIZE
 967                 if (max_fd >= FD_SETSIZE)
 968                     krb5_errx(context, 1, "fd too large");
 969 #endif
 970 #endif
 971                 FD_SET(d[i].s, &fds);
 972             }
 973         }
 974
 975         tmout.tv_sec = TCP_TIMEOUT;
 976         tmout.tv_usec = 0;
 977         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 978         case 0:
 979             break;
 980         case -1:
 981             if (errno != EINTR)
 982                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 983             break;
 984         default:
 985 #ifdef HAVE_FORK
 986             if (islive > -1 && FD_ISSET(islive, &fds))
 987                 handle_islive(islive);
 988 #endif
 989             for (i = 0; i < ndescr; i++)
 990                 if (!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 991                     min_free = next_min_free(context, dp, ndescrp);
 992                     ndescr = *ndescrp;
 993                     d = *dp;
 994
 995                     if (d[i].type == SOCK_DGRAM)
 996                         handle_udp(context, config, &d[i]);
 997                     else if (d[i].type == SOCK_STREAM)
 998                         handle_tcp(context, config, d, i, min_free);
 999                 }
1000         }
1001     }
1002
1003     switch (exit_flag) {
1004     case -1:
1005         kdc_log(context, config, 0,
1006                 "KDC worker process exiting because KDC master exited.");
1007         break;
1008 #ifdef SIGXCPU
1009     case SIGXCPU:
1010         kdc_log(context, config, 0, "CPU time limit exceeded");
1011         break;
1012 #endif
1013     case SIGINT:
1014     case SIGTERM:
1015         kdc_log(context, config, 0, "Terminated");
1016         break;
1017     default:
1018         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
1019         break;
1020     }
1021 }
1022
1023 #ifdef __APPLE__
1024 static void
1025 bonjour_kid(krb5_context context, krb5_kdc_configuration *config, const char *argv0, int *islive)
1026 {
1027     char buf;
1028
1029     if (do_bonjour > 0) {
1030         bonjour_announce(context, config);
1031
1032         while (read(0, &buf, 1) == 1)
1033             continue;
1034         _exit(0);
1035     }
1036
1037     if ((bonjour_pid = fork()) != 0)
1038         return;
1039
1040     close(islive[0]);
1041     if (dup2(islive[1], 0) == -1)
1042         err(1, "failed to announce with bonjour (dup)");
1043     if (islive[1] != 0)
1044         close(islive[1]);
1045     execlp(argv0, "kdc", "--bonjour", NULL);
1046     err(1, "failed to announce with bonjour (exec)");
1047 }
1048 #endif
1049
1050 #ifdef HAVE_FORK
1051 static void
1052 kill_kids(pid_t *pids, int max_kids, int sig)
1053 {
1054     int i;
1055
1056     for (i=0; i < max_kids; i++)
1057         if (pids[i] > 0)
1058             kill(sig, pids[i]);
1059     if (bonjour_pid > 0)
1060         kill(sig, bonjour_pid);
1061 }
1062
1063 static int
1064 reap_kid(krb5_context context, krb5_kdc_configuration *config,
1065          pid_t *pids, int max_kids, int options)
1066 {
1067     pid_t pid;
1068     char *what = "untracked";
1069     int status;
1070     int i = 0; /* quiet warnings */
1071     int ret = 0;
1072     int level = 3;
1073     const char *sev = "info: ";
1074
1075     pid = waitpid(-1, &status, options);
1076     if (pid <= 0)
1077         return 0;
1078
1079     if (pid == bonjour_pid) {
1080         bonjour_pid = (pid_t)-1;
1081         what = "bonjour";
1082     } else {
1083         for (i=0; i < max_kids; i++) {
1084             if (pids[i] == pid) {
1085                 pids[i] = (pid_t)-1;
1086                 what = "worker";
1087                 ret = 1;
1088                 break;
1089             }
1090         }
1091
1092         if (i == max_kids) {
1093             /* should not happen */
1094             sev = "warning: ";
1095             level = 2;
1096         }
1097     }
1098
1099     if (WIFEXITED(status))
1100         kdc_log(context, config, level,
1101                 "%sKDC reaped %s process: %d, exit status: %d",
1102                 sev, what, (int)pid, WEXITSTATUS(status));
1103     else if (WIFSIGNALED(status))
1104         kdc_log(context, config, level,
1105                 "%sKDC reaped %s process: %d, term signal %d%s",
1106                 sev, what, (int)pid, WTERMSIG(status),
1107                 WCOREDUMP(status) ? " (core dumped)" : "");
1108     else
1109         kdc_log(context, config, level, "%sKDC reaped %s process: %d",
1110                 sev, what, (int)pid);
1111
1112     return ret;
1113 }
1114
1115 static int
1116 reap_kids(krb5_context context, krb5_kdc_configuration *config,
1117           pid_t *pids, int max_kids)
1118 {
1119     int reaped = 0;
1120
1121     for (;;) {
1122         if (reap_kid(context, config, pids, max_kids, WNOHANG) == 0)
1123             break;
1124         reaped++;
1125     }
1126
1127     return reaped;
1128 }
1129
1130 static void
1131 select_sleep(int microseconds)
1132 {
1133     struct timeval tv;
1134
1135     tv.tv_sec = microseconds / 1000000;
1136     tv.tv_usec = microseconds % 1000000;
1137     select(0, NULL, NULL, NULL, &tv);
1138 }
1139 #endif
1140
1141 void
1142 start_kdc(krb5_context context,
1143           krb5_kdc_configuration *config, const char *argv0)
1144 {
1145     struct timeval tv1;
1146     struct timeval tv2;
1147     struct descr *d;
1148     unsigned int ndescr;
1149     pid_t pid = -1;
1150 #ifdef HAVE_FORK
1151     pid_t *pids;
1152     int max_kdcs = config->num_kdc_processes;
1153     int num_kdcs = 0;
1154     int i;
1155     int islive[2];
1156 #endif
1157
1158 #ifdef __APPLE__
1159     if (do_bonjour > 0)
1160         bonjour_kid(context, config, argv0, NULL);
1161 #endif
1162
1163 #ifdef HAVE_FORK
1164 #ifdef _SC_NPROCESSORS_ONLN
1165     if (max_kdcs < 1)
1166         max_kdcs = sysconf(_SC_NPROCESSORS_ONLN);
1167 #endif
1168
1169     if (max_kdcs < 1)
1170         max_kdcs = 1;
1171
1172     pids = calloc(max_kdcs, sizeof(*pids));
1173     if (pids == NULL)
1174         krb5_err(context, 1, errno, "malloc");
1175
1176     /*
1177      * We open a socketpair of which we hand one end to each of our kids.
1178      * When we exit, for whatever reason, the children will notice an EOF
1179      * on their end and be able to cleanly exit.
1180      */
1181
1182     if (socketpair(PF_UNIX, SOCK_STREAM, 0, islive) == -1)
1183         krb5_errx(context, 1, "socketpair");
1184     socket_set_nonblocking(islive[1], 1);
1185 #endif
1186
1187     ndescr = init_sockets(context, config, &d);
1188     if(ndescr <= 0)
1189         krb5_errx(context, 1, "No sockets!");
1190
1191 #ifdef HAVE_FORK
1192
1193 # ifdef __APPLE__
1194     if (do_bonjour < 0)
1195         bonjour_kid(context, config, argv0, islive);
1196 # endif
1197
1198     kdc_log(context, config, 3, "KDC started master process pid=%d", getpid());
1199 #else
1200     kdc_log(context, config, 3, "KDC started pid=%d", getpid());
1201 #endif
1202
1203     roken_detach_finish(NULL, daemon_child);
1204
1205 #ifdef HAVE_FORK
1206     if (!testing_flag) {
1207         /* Note that we might never execute the body of this loop */
1208         while (exit_flag == 0) {
1209
1210             if (num_kdcs >= max_kdcs) {
1211                 num_kdcs -= reap_kid(context, config, pids, max_kdcs, 0);
1212                 continue;
1213             }
1214
1215             if (num_kdcs > 0)
1216                 num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1217
1218             pid = fork();
1219             switch (pid) {
1220             case 0:
1221                 close(islive[0]);
1222                 loop(context, config, &d, &ndescr, islive[1]);
1223                 exit(0);
1224             case -1:
1225                 /* XXXrcd: hmmm, do something useful?? */
1226                 kdc_log(context, config, 1,
1227                         "KDC master process could not fork worker process");
1228                 sleep(10);
1229                 break;
1230             default:
1231                 for (i = 0; i < max_kdcs; i++) {
1232                     if (pids[i] <= 0) {
1233                         pids[i] = pid;
1234                         break;
1235                     }
1236                 }
1237                 if (i >= max_kdcs) {
1238                     /* This should not happen */
1239                     kdc_log(context, config, 1,
1240                             "warning: forked untracked child process: %d",
1241                             (int)pid);
1242                 }
1243                 kdc_log(context, config, 3, "KDC worker process started: %d",
1244                         pid);
1245                 num_kdcs++;
1246                 /* Slow down the creation of KDCs... */
1247                 select_sleep(12500);
1248                 break;
1249             }
1250         }
1251
1252         /* Closing these sockets should cause the kids to die... */
1253
1254         close(islive[0]);
1255         close(islive[1]);
1256
1257         /* Close our listener sockets before terminating workers */
1258         for (i = 0; i < ndescr; ++i)
1259             clear_descr(&d[i]);
1260
1261         gettimeofday(&tv1, NULL);
1262         tv2 = tv1;
1263
1264         /* Reap every 10ms, terminate stragglers once a second, give up after 10 */
1265         for (;;) {
1266             struct timeval tv3;
1267             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1268             if (num_kdcs == 0 && bonjour_pid <= 0)
1269                 goto end;
1270             /*
1271              * Using select to sleep will fail with EINTR if we receive a
1272              * SIGCHLD.  This is desirable.
1273              */
1274             select_sleep(10000);
1275             gettimeofday(&tv3, NULL);
1276             if (tv3.tv_sec - tv1.tv_sec > 10 ||
1277                 (tv3.tv_sec - tv1.tv_sec == 10 && tv3.tv_usec >= tv1.tv_usec))
1278                 break;
1279             if (tv3.tv_sec - tv2.tv_sec > 1 ||
1280                 (tv3.tv_sec - tv2.tv_sec == 1 && tv3.tv_usec >= tv2.tv_usec)) {
1281                 kill_kids(pids, max_kdcs, SIGTERM);
1282                 tv2 = tv3;
1283             }
1284         }
1285
1286         /* Kill stragglers and reap every 200ms, give up after 15s */
1287         for (;;) {
1288             kill_kids(pids, max_kdcs, SIGKILL);
1289             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1290             if (num_kdcs == 0 && bonjour_pid <= 0)
1291                 break;
1292             select_sleep(200000);
1293             gettimeofday(&tv2, NULL);
1294             if (tv2.tv_sec - tv1.tv_sec > 15 ||
1295                 (tv2.tv_sec - tv1.tv_sec == 15 && tv2.tv_usec >= tv1.tv_usec))
1296                 break;
1297         }
1298
1299      end:
1300         kdc_log(context, config, 3, "KDC master process exiting");
1301     } else {
1302         loop(context, config, &d, &ndescr, -1);
1303         kdc_log(context, config, 3, "KDC exiting");
1304     }
1305     free(pids);
1306 #else
1307     loop(context, config, &d, &ndescr, -1);
1308     kdc_log(context, config, 3, "KDC exiting");
1309 #endif
1310
1311     free(d);
1312 }