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, 3, "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, 4,
 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                      1, "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, 1, "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, 1,
 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, 1, "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     unsigned int x;
 519
 520     for (p = q = (unsigned char *)buf; *p; p++, q++) {
 521         if (*p == '%') {
 522             if (!(isxdigit(p[1]) && isxdigit(p[2])))
 523                 return -1;
 524
 525             if (sscanf((char *)p + 1, "%2x", &x) != 1)
 526                 return -1;
 527
 528             *q = x;
 529             p += 2;
 530         } else {
 531             *q = *p;
 532         }
 533     }
 534     *q = '\0';
 535     return 0;
 536 }
 537
 538 #define TCP_TIMEOUT 4
 539
 540 /*
 541  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 542  */
 543
 544 static void
 545 add_new_tcp (krb5_context context,
 546              krb5_kdc_configuration *config,
 547              struct descr *d, int parent, int child)
 548 {
 549     krb5_socket_t s;
 550
 551     if (child == -1)
 552         return;
 553
 554     d[child].sock_len = sizeof(d[child].__ss);
 555     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 556     if(rk_IS_BAD_SOCKET(s)) {
 557         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 558             krb5_warn(context, rk_SOCK_ERRNO, "accept");
 559         return;
 560     }
 561
 562 #ifdef FD_SETSIZE
 563     if (s >= FD_SETSIZE) {
 564         krb5_warnx(context, "socket FD too large");
 565         rk_closesocket (s);
 566         return;
 567     }
 568 #endif
 569
 570     d[child].s = s;
 571     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 572     d[child].type = SOCK_STREAM;
 573     addr_to_string (context,
 574                     d[child].sa, d[child].sock_len,
 575                     d[child].addr_string, sizeof(d[child].addr_string));
 576 }
 577
 578 /*
 579  * Grow `d' to handle at least `n'.
 580  * Return != 0 if fails
 581  */
 582
 583 static int
 584 grow_descr (krb5_context context,
 585             krb5_kdc_configuration *config,
 586             struct descr *d, size_t n)
 587 {
 588     if (d->size - d->len < n) {
 589         unsigned char *tmp;
 590         size_t grow;
 591
 592         grow = max(1024, d->len + n);
 593         if (d->size + grow > max_request_tcp) {
 594             kdc_log(context, config, 2, "Request exceeds max request size (%lu bytes).",
 595                     (unsigned long)d->size + grow);
 596             clear_descr(d);
 597             return -1;
 598         }
 599         tmp = realloc (d->buf, d->size + grow);
 600         if (tmp == NULL) {
 601             kdc_log(context, config, 1, "Failed to re-allocate %lu bytes.",
 602                     (unsigned long)d->size + grow);
 603             clear_descr(d);
 604             return -1;
 605         }
 606         d->size += grow;
 607         d->buf = tmp;
 608     }
 609     return 0;
 610 }
 611
 612 /*
 613  * Try to handle the TCP data at `d->buf, d->len'.
 614  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 615  */
 616
 617 static int
 618 handle_vanilla_tcp (krb5_context context,
 619                     krb5_kdc_configuration *config,
 620                     struct descr *d)
 621 {
 622     krb5_storage *sp;
 623     uint32_t len;
 624
 625     sp = krb5_storage_from_mem(d->buf, d->len);
 626     if (sp == NULL) {
 627         kdc_log (context, config, 1, "krb5_storage_from_mem failed");
 628         return -1;
 629     }
 630     krb5_ret_uint32(sp, &len);
 631     krb5_storage_free(sp);
 632     if(d->len - 4 >= len) {
 633         memmove(d->buf, d->buf + 4, d->len - 4);
 634         d->len -= 4;
 635         return 1;
 636     }
 637     return 0;
 638 }
 639
 640 /*
 641  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 642  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 643  */
 644
 645 static int
 646 handle_http_tcp (krb5_context context,
 647                  krb5_kdc_configuration *config,
 648                  struct descr *d)
 649 {
 650     char *s, *p, *t;
 651     void *data;
 652     char *proto;
 653     int len;
 654
 655     s = (char *)d->buf;
 656
 657     /* If its a multi line query, truncate off the first line */
 658     p = strstr(s, "\r\n");
 659     if (p)
 660         *p = 0;
 661
 662     p = NULL;
 663     t = strtok_r(s, " \t", &p);
 664     if (t == NULL) {
 665         kdc_log(context, config, 2,
 666                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 667         return -1;
 668     }
 669
 670     t = strtok_r(NULL, " \t", &p);
 671     if(t == NULL) {
 672         kdc_log(context, config, 2,
 673                 "Missing HTTP GET data in request from %s", d->addr_string);
 674         return -1;
 675     }
 676
 677     data = malloc(strlen(t));
 678     if (data == NULL) {
 679         kdc_log(context, config, 1, "Failed to allocate %lu bytes",
 680                 (unsigned long)strlen(t));
 681         return -1;
 682     }
 683     if(*t == '/')
 684         t++;
 685     if(de_http(t) != 0) {
 686         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 687         kdc_log(context, config, 4, "HTTP request: %s", t);
 688         free(data);
 689         return -1;
 690     }
 691     proto = strtok_r(NULL, " \t", &p);
 692     if (proto == NULL) {
 693         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 694         free(data);
 695         return -1;
 696     }
 697     len = rk_base64_decode(t, data);
 698     if(len <= 0){
 699         const char *msg =
 700             " 404 Not found\r\n"
 701             "Server: Heimdal/" VERSION "\r\n"
 702             "Cache-Control: no-cache\r\n"
 703             "Pragma: no-cache\r\n"
 704             "Content-type: text/html\r\n"
 705             "Content-transfer-encoding: 8bit\r\n\r\n"
 706             "<TITLE>404 Not found</TITLE>\r\n"
 707             "<H1>404 Not found</H1>\r\n"
 708             "That page doesn't exist, maybe you are looking for "
 709             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 710         kdc_log(context, config, 2, "HTTP request from %s is non KDC request", d->addr_string);
 711         kdc_log(context, config, 4, "HTTP request: %s", t);
 712         free(data);
 713         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 714             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 715                     d->addr_string, strerror(rk_SOCK_ERRNO));
 716             return -1;
 717         }
 718         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 719             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 720                     d->addr_string, strerror(rk_SOCK_ERRNO));
 721             return -1;
 722         }
 723         return -1;
 724     }
 725     {
 726         const char *msg =
 727             " 200 OK\r\n"
 728             "Server: Heimdal/" VERSION "\r\n"
 729             "Cache-Control: no-cache\r\n"
 730             "Pragma: no-cache\r\n"
 731             "Content-type: application/octet-stream\r\n"
 732             "Content-transfer-encoding: binary\r\n\r\n";
 733         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 734             free(data);
 735             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 736                     d->addr_string, strerror(rk_SOCK_ERRNO));
 737             return -1;
 738         }
 739         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 740             free(data);
 741             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 742                     d->addr_string, strerror(rk_SOCK_ERRNO));
 743             return -1;
 744         }
 745     }
 746     if ((size_t)len > d->len)
 747         len = d->len;
 748     memcpy(d->buf, data, len);
 749     d->len = len;
 750     free(data);
 751     return 1;
 752 }
 753
 754 static int
 755 http1_request_taste(const unsigned char *req, size_t len)
 756 {
 757     return !!((len >= sizeof("GET ") - 1 &&
 758                memcmp(req, "GET ", sizeof("GET ") - 1) == 0) ||
 759               (len >= sizeof("HEAD ") - 1 &&
 760                memcmp(req, "HEAD ", sizeof("HEAD ") - 1) == 0));
 761 }
 762
 763 static int
 764 http1_request_is_complete(const unsigned char *req, size_t len)
 765 {
 766
 767     return http1_request_taste(req, len) &&
 768         memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 769
 770     /*
 771      * For POST (the MSFT variant of this protocol) we'll need something like
 772      * this (plus check for Content-Length/Transfer-Encoding):
 773      *
 774      *  const unsigned char *body;
 775      *  if ((body = memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4)) == NULL)
 776      *      return 0;
 777      *  body += sizeof("\r\n\r\n") - 4;
 778      *  len -= (body - req);
 779      *  return memmem(body, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 780      *
 781      * Since the POST-based variant runs over HTTPS, we'll probably implement
 782      * that in a proxy instead of here.
 783      */
 784 }
 785
 786 /*
 787  * Handle incoming data to the TCP socket in `d[index]'
 788  */
 789
 790 static void
 791 handle_tcp(krb5_context context,
 792            krb5_kdc_configuration *config,
 793            struct descr *d, int idx, int min_free)
 794 {
 795     unsigned char buf[1024];
 796     int n;
 797     int ret = 0;
 798
 799     if (d[idx].timeout == 0) {
 800         add_new_tcp (context, config, d, idx, min_free);
 801         return;
 802     }
 803
 804     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 805     if(rk_IS_SOCKET_ERROR(n)){
 806         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 807                   d[idx].addr_string, descr_type(d + idx),
 808                   ntohs(d[idx].port));
 809         return;
 810     } else if (n == 0) {
 811         krb5_warnx(context, "connection closed before end of data after %lu "
 812                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 813                    d[idx].addr_string, descr_type(d + idx),
 814                    ntohs(d[idx].port));
 815         clear_descr (d + idx);
 816         return;
 817     }
 818     if (grow_descr (context, config, &d[idx], n))
 819         return;
 820     memcpy(d[idx].buf + d[idx].len, buf, n);
 821     d[idx].len += n;
 822     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 823         ret = handle_vanilla_tcp (context, config, &d[idx]);
 824     } else if (enable_http &&
 825                http1_request_taste(d[idx].buf, d[idx].len)) {
 826
 827         if (http1_request_is_complete(d[idx].buf, d[idx].len)) {
 828             /* NUL-terminate at the request header ending \r\n\r\n */
 829             d[idx].buf[d[idx].len - 4] = '\0';
 830             ret = handle_http_tcp (context, config, &d[idx]);
 831         }
 832     } else if (d[idx].len > 4) {
 833         kdc_log (context, config,
 834                  2, "TCP data of strange type from %s to %s/%d",
 835                  d[idx].addr_string, descr_type(d + idx),
 836                  ntohs(d[idx].port));
 837         if (d[idx].buf[0] & 0x80) {
 838             krb5_data reply;
 839
 840             kdc_log (context, config, 2, "TCP extension not supported");
 841
 842             ret = krb5_mk_error(context,
 843                                 KRB5KRB_ERR_FIELD_TOOLONG,
 844                                 NULL,
 845                                 NULL,
 846                                 NULL,
 847                                 NULL,
 848                                 NULL,
 849                                 NULL,
 850                                 &reply);
 851             if (ret == 0) {
 852                 send_reply(context, config, TRUE, d + idx, &reply);
 853                 krb5_data_free(&reply);
 854             }
 855         }
 856         clear_descr(d + idx);
 857         return;
 858     }
 859
 860     /*
 861      * ret == 0 -> not enough of request buffered -> wait for more
 862      * ret == 1 -> go ahead and perform the request
 863      * ret != 0 (really, < 0) -> error, probably ENOMEM, close connection
 864      */
 865     if (ret == 1)
 866         do_request(context, config,
 867                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 868
 869     /*
 870      * Note: this means we don't keep the connection open even where we
 871      * the protocol permits it.
 872      */
 873     if (ret != 0)
 874         clear_descr(d + idx);
 875 }
 876
 877 #ifdef HAVE_FORK
 878 static void
 879 handle_islive(int fd)
 880 {
 881     char buf;
 882     int ret;
 883
 884     ret = read(fd, &buf, 1);
 885     if (ret != 1)
 886         exit_flag = -1;
 887 }
 888 #endif
 889
 890 static krb5_boolean
 891 realloc_descrs(struct descr **d, unsigned int *ndescr)
 892 {
 893     struct descr *tmp;
 894     size_t i;
 895
 896     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 897     if(tmp == NULL)
 898         return FALSE;
 899
 900     *d = tmp;
 901     reinit_descrs (*d, *ndescr);
 902     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 903     for(i = *ndescr; i < *ndescr + 4; i++)
 904         init_descr (*d + i);
 905
 906     *ndescr += 4;
 907
 908     return TRUE;
 909 }
 910
 911 static int
 912 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 913 {
 914     size_t i;
 915     int min_free;
 916
 917     for(i = 0; i < *ndescr; i++) {
 918         int s = (*d + i)->s;
 919         if(rk_IS_BAD_SOCKET(s))
 920             return i;
 921     }
 922
 923     min_free = *ndescr;
 924     if(!realloc_descrs(d, ndescr)) {
 925         min_free = -1;
 926         krb5_warnx(context, "No memory");
 927     }
 928
 929     return min_free;
 930 }
 931
 932 static void
 933 loop(krb5_context context, krb5_kdc_configuration *config,
 934      struct descr **dp, unsigned int *ndescrp, int islive)
 935 {
 936     struct descr *d = *dp;
 937     unsigned int ndescr = *ndescrp;
 938
 939     while (exit_flag == 0) {
 940         struct timeval tmout;
 941         fd_set fds;
 942         int min_free = -1;
 943         int max_fd = 0;
 944         size_t i;
 945
 946         FD_ZERO(&fds);
 947         if (islive > -1) {
 948             FD_SET(islive, &fds);
 949             max_fd = islive;
 950         }
 951         for (i = 0; i < ndescr; i++) {
 952             if (!rk_IS_BAD_SOCKET(d[i].s)) {
 953                 if (d[i].type == SOCK_STREAM &&
 954                    d[i].timeout && d[i].timeout < time(NULL)) {
 955                     kdc_log(context, config, 2,
 956                             "TCP-connection from %s expired after %lu bytes",
 957                             d[i].addr_string, (unsigned long)d[i].len);
 958                     clear_descr(&d[i]);
 959                     continue;
 960                 }
 961 #ifndef NO_LIMIT_FD_SETSIZE
 962                 if (max_fd < d[i].s)
 963                     max_fd = d[i].s;
 964 #ifdef FD_SETSIZE
 965                 if (max_fd >= FD_SETSIZE)
 966                     krb5_errx(context, 1, "fd too large");
 967 #endif
 968 #endif
 969                 FD_SET(d[i].s, &fds);
 970             }
 971         }
 972
 973         tmout.tv_sec = TCP_TIMEOUT;
 974         tmout.tv_usec = 0;
 975         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 976         case 0:
 977             break;
 978         case -1:
 979             if (errno != EINTR)
 980                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 981             break;
 982         default:
 983 #ifdef HAVE_FORK
 984             if (islive > -1 && FD_ISSET(islive, &fds))
 985                 handle_islive(islive);
 986 #endif
 987             for (i = 0; i < ndescr; i++)
 988                 if (!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 989                     min_free = next_min_free(context, dp, ndescrp);
 990                     ndescr = *ndescrp;
 991                     d = *dp;
 992
 993                     if (d[i].type == SOCK_DGRAM)
 994                         handle_udp(context, config, &d[i]);
 995                     else if (d[i].type == SOCK_STREAM)
 996                         handle_tcp(context, config, d, i, min_free);
 997                 }
 998         }
 999     }
1000
1001     switch (exit_flag) {
1002     case -1:
1003         kdc_log(context, config, 0,
1004                 "KDC worker process exiting because KDC master exited.");
1005         break;
1006 #ifdef SIGXCPU
1007     case SIGXCPU:
1008         kdc_log(context, config, 0, "CPU time limit exceeded");
1009         break;
1010 #endif
1011     case SIGINT:
1012     case SIGTERM:
1013         kdc_log(context, config, 0, "Terminated");
1014         break;
1015     default:
1016         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
1017         break;
1018     }
1019 }
1020
1021 #ifdef __APPLE__
1022 static void
1023 bonjour_kid(krb5_context context, krb5_kdc_configuration *config, const char *argv0, int *islive)
1024 {
1025     char buf;
1026
1027     if (do_bonjour > 0) {
1028         bonjour_announce(context, config);
1029
1030         while (read(0, &buf, 1) == 1)
1031             continue;
1032         _exit(0);
1033     }
1034
1035     if ((bonjour_pid = fork()) != 0)
1036         return;
1037
1038     close(islive[0]);
1039     if (dup2(islive[1], 0) == -1)
1040         err(1, "failed to announce with bonjour (dup)");
1041     if (islive[1] != 0)
1042         close(islive[1]);
1043     execlp(argv0, "kdc", "--bonjour", NULL);
1044     err(1, "failed to announce with bonjour (exec)");
1045 }
1046 #endif
1047
1048 #ifdef HAVE_FORK
1049 static void
1050 kill_kids(pid_t *pids, int max_kids, int sig)
1051 {
1052     int i;
1053
1054     for (i=0; i < max_kids; i++)
1055         if (pids[i] > 0)
1056             kill(sig, pids[i]);
1057     if (bonjour_pid > 0)
1058         kill(sig, bonjour_pid);
1059 }
1060
1061 static int
1062 reap_kid(krb5_context context, krb5_kdc_configuration *config,
1063          pid_t *pids, int max_kids, int options)
1064 {
1065     pid_t pid;
1066     char *what;
1067     int status;
1068     int i = 0; /* quiet warnings */
1069     int ret = 0;
1070     int level = 3;
1071     const char *sev = "info: ";
1072
1073     pid = waitpid(-1, &status, options);
1074     if (pid <= 0)
1075         return 0;
1076
1077     if (pid == bonjour_pid) {
1078         bonjour_pid = (pid_t)-1;
1079         what = "bonjour";
1080     } else {
1081         for (i=0; i < max_kids; i++) {
1082             if (pids[i] == pid) {
1083                 pids[i] = (pid_t)-1;
1084                 what = "worker";
1085                 ret = 1;
1086                 break;
1087             }
1088         }
1089
1090         if (i == max_kids) {
1091             /* should not happen */
1092             what = "untracked";
1093             sev = "warning: ";
1094             level = 2;
1095         }
1096     }
1097
1098     if (WIFEXITED(status))
1099         kdc_log(context, config, level,
1100                 "%sKDC reaped %s process: %d, exit status: %d",
1101                 sev, what, (int)pid, WEXITSTATUS(status));
1102     else if (WIFSIGNALED(status))
1103         kdc_log(context, config, level,
1104                 "%sKDC reaped %s process: %d, term signal %d%s",
1105                 sev, what, (int)pid, WTERMSIG(status),
1106                 WCOREDUMP(status) ? " (core dumped)" : "");
1107     else
1108         kdc_log(context, config, level, "%sKDC reaped %s process: %d",
1109                 sev, what, (int)pid);
1110
1111     return ret;
1112 }
1113
1114 static int
1115 reap_kids(krb5_context context, krb5_kdc_configuration *config,
1116           pid_t *pids, int max_kids)
1117 {
1118     int reaped = 0;
1119
1120     for (;;) {
1121         if (reap_kid(context, config, pids, max_kids, WNOHANG) == 0)
1122             break;
1123         reaped++;
1124     }
1125
1126     return reaped;
1127 }
1128
1129 static void
1130 select_sleep(int microseconds)
1131 {
1132     struct timeval tv;
1133
1134     tv.tv_sec = microseconds / 1000000;
1135     tv.tv_usec = microseconds % 1000000;
1136     select(0, NULL, NULL, NULL, &tv);
1137 }
1138 #endif
1139
1140 void
1141 start_kdc(krb5_context context,
1142           krb5_kdc_configuration *config, const char *argv0)
1143 {
1144     struct timeval tv1;
1145     struct timeval tv2;
1146     struct descr *d;
1147     unsigned int ndescr;
1148     pid_t pid = -1;
1149 #ifdef HAVE_FORK
1150     pid_t *pids;
1151     int max_kdcs = config->num_kdc_processes;
1152     int num_kdcs = 0;
1153     int i;
1154     int islive[2];
1155 #endif
1156
1157 #ifdef __APPLE__
1158     if (do_bonjour > 0)
1159         bonjour_kid(context, config, argv0, NULL);
1160 #endif
1161
1162 #ifdef HAVE_FORK
1163 #ifdef _SC_NPROCESSORS_ONLN
1164     if (max_kdcs < 1)
1165         max_kdcs = sysconf(_SC_NPROCESSORS_ONLN);
1166 #endif
1167
1168     if (max_kdcs < 1)
1169         max_kdcs = 1;
1170
1171     pids = calloc(max_kdcs, sizeof(*pids));
1172     if (pids == NULL)
1173         krb5_err(context, 1, errno, "malloc");
1174
1175     /*
1176      * We open a socketpair of which we hand one end to each of our kids.
1177      * When we exit, for whatever reason, the children will notice an EOF
1178      * on their end and be able to cleanly exit.
1179      */
1180
1181     if (socketpair(PF_UNIX, SOCK_STREAM, 0, islive) == -1)
1182         krb5_errx(context, 1, "socketpair");
1183     socket_set_nonblocking(islive[1], 1);
1184 #endif
1185
1186     ndescr = init_sockets(context, config, &d);
1187     if(ndescr <= 0)
1188         krb5_errx(context, 1, "No sockets!");
1189
1190 #ifdef HAVE_FORK
1191
1192 # ifdef __APPLE__
1193     if (do_bonjour < 0)
1194         bonjour_kid(context, config, argv0, islive);
1195 # endif
1196
1197     kdc_log(context, config, 3, "KDC started master process pid=%d", getpid());
1198 #else
1199     kdc_log(context, config, 3, "KDC started pid=%d", getpid());
1200 #endif
1201
1202     roken_detach_finish(NULL, daemon_child);
1203
1204 #ifdef HAVE_FORK
1205     if (!testing_flag) {
1206         /* Note that we might never execute the body of this loop */
1207         while (exit_flag == 0) {
1208
1209             if (num_kdcs >= max_kdcs) {
1210                 num_kdcs -= reap_kid(context, config, pids, max_kdcs, 0);
1211                 continue;
1212             }
1213
1214             if (num_kdcs > 0)
1215                 num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1216
1217             pid = fork();
1218             switch (pid) {
1219             case 0:
1220                 close(islive[0]);
1221                 loop(context, config, &d, &ndescr, islive[1]);
1222                 exit(0);
1223             case -1:
1224                 /* XXXrcd: hmmm, do something useful?? */
1225                 kdc_log(context, config, 1,
1226                         "KDC master process could not fork worker process");
1227                 sleep(10);
1228                 break;
1229             default:
1230                 for (i = 0; i < max_kdcs; i++) {
1231                     if (pids[i] <= 0) {
1232                         pids[i] = pid;
1233                         break;
1234                     }
1235                 }
1236                 if (i >= max_kdcs) {
1237                     /* This should not happen */
1238                     kdc_log(context, config, 1,
1239                             "warning: forked untracked child process: %d",
1240                             (int)pid);
1241                 }
1242                 kdc_log(context, config, 3, "KDC worker process started: %d",
1243                         pid);
1244                 num_kdcs++;
1245                 /* Slow down the creation of KDCs... */
1246                 select_sleep(12500);
1247                 break;
1248             }
1249         }
1250
1251         /* Closing these sockets should cause the kids to die... */
1252
1253         close(islive[0]);
1254         close(islive[1]);
1255
1256         /* Close our listener sockets before terminating workers */
1257         for (i = 0; i < ndescr; ++i)
1258             clear_descr(&d[i]);
1259
1260         gettimeofday(&tv1, NULL);
1261         tv2 = tv1;
1262
1263         /* Reap every 10ms, terminate stragglers once a second, give up after 10 */
1264         for (;;) {
1265             struct timeval tv3;
1266             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1267             if (num_kdcs == 0 && bonjour_pid <= 0)
1268                 goto end;
1269             /*
1270              * Using select to sleep will fail with EINTR if we receive a
1271              * SIGCHLD.  This is desirable.
1272              */
1273             select_sleep(10000);
1274             gettimeofday(&tv3, NULL);
1275             if (tv3.tv_sec - tv1.tv_sec > 10 ||
1276                 (tv3.tv_sec - tv1.tv_sec == 10 && tv3.tv_usec >= tv1.tv_usec))
1277                 break;
1278             if (tv3.tv_sec - tv2.tv_sec > 1 ||
1279                 (tv3.tv_sec - tv2.tv_sec == 1 && tv3.tv_usec >= tv2.tv_usec)) {
1280                 kill_kids(pids, max_kdcs, SIGTERM);
1281                 tv2 = tv3;
1282             }
1283         }
1284
1285         /* Kill stragglers and reap every 200ms, give up after 15s */
1286         for (;;) {
1287             kill_kids(pids, max_kdcs, SIGKILL);
1288             num_kdcs -= reap_kids(context, config, pids, max_kdcs);
1289             if (num_kdcs == 0 && bonjour_pid <= 0)
1290                 break;
1291             select_sleep(200000);
1292             gettimeofday(&tv2, NULL);
1293             if (tv2.tv_sec - tv1.tv_sec > 15 ||
1294                 (tv2.tv_sec - tv1.tv_sec == 15 && tv2.tv_usec >= tv1.tv_usec))
1295                 break;
1296         }
1297
1298      end:
1299         kdc_log(context, config, 3, "KDC master process exiting");
1300     } else {
1301         loop(context, config, &d, &ndescr, -1);
1302         kdc_log(context, config, 3, "KDC exiting");
1303     }
1304     free(pids);
1305 #else
1306     loop(context, config, &d, &ndescr, -1);
1307     kdc_log(context, config, 3, "KDC exiting");
1308 #endif
1309
1310     free(d);
1311 }