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     socket_set_keepalive(d->s, 1);
 295 }
 296
 297 /*
 298  * Allocate descriptors for all the sockets that we should listen on
 299  * and return the number of them.
 300  */
 301
 302 static int
 303 init_sockets(krb5_context context,
 304              krb5_kdc_configuration *config,
 305              struct descr **desc)
 306 {
 307     krb5_error_code ret;
 308     size_t i, j;
 309     struct descr *d;
 310     int num = 0;
 311     krb5_addresses addresses;
 312
 313     if (explicit_addresses.len) {
 314         addresses = explicit_addresses;
 315     } else {
 316         ret = krb5_get_all_server_addrs (context, &addresses);
 317         if (ret)
 318             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 319     }
 320     parse_ports(context, config, port_str);
 321     d = malloc(addresses.len * num_ports * sizeof(*d));
 322     if (d == NULL)
 323         krb5_errx(context, 1, "malloc(%lu) failed",
 324                   (unsigned long)num_ports * sizeof(*d));
 325
 326     for (i = 0; i < num_ports; i++){
 327         for (j = 0; j < addresses.len; ++j) {
 328             init_socket(context, config, &d[num], &addresses.val[j],
 329                         ports[i].family, ports[i].type, ports[i].port);
 330             if(d[num].s != rk_INVALID_SOCKET){
 331                 char a_str[80];
 332                 size_t len;
 333
 334                 krb5_print_address (&addresses.val[j], a_str,
 335                                     sizeof(a_str), &len);
 336
 337                 kdc_log(context, config, 3, "listening on %s port %u/%s",
 338                         a_str,
 339                         ntohs(ports[i].port),
 340                         (ports[i].type == SOCK_STREAM) ? "tcp" : "udp");
 341                 /* XXX */
 342                 num++;
 343             }
 344         }
 345     }
 346     krb5_free_addresses (context, &addresses);
 347     d = realloc(d, num * sizeof(*d));
 348     if (d == NULL && num != 0)
 349         krb5_errx(context, 1, "realloc(%lu) failed",
 350                   (unsigned long)num * sizeof(*d));
 351     reinit_descrs (d, num);
 352     *desc = d;
 353     return num;
 354 }
 355
 356 /*
 357  *
 358  */
 359
 360 static const char *
 361 descr_type(struct descr *d)
 362 {
 363     if (d->type == SOCK_DGRAM)
 364         return "udp";
 365     else if (d->type == SOCK_STREAM)
 366         return "tcp";
 367     return "unknown";
 368 }
 369
 370 static void
 371 addr_to_string(krb5_context context,
 372                struct sockaddr *addr, size_t addr_len, char *str, size_t len)
 373 {
 374     krb5_address a;
 375     if(krb5_sockaddr2address(context, addr, &a) == 0) {
 376         if(krb5_print_address(&a, str, len, &len) == 0) {
 377             krb5_free_address(context, &a);
 378             return;
 379         }
 380         krb5_free_address(context, &a);
 381     }
 382     snprintf(str, len, "<family=%d>", addr->sa_family);
 383 }
 384
 385 /*
 386  *
 387  */
 388
 389 static void
 390 send_reply(krb5_context context,
 391            krb5_kdc_configuration *config,
 392            krb5_boolean prependlength,
 393            struct descr *d,
 394            krb5_data *reply)
 395 {
 396     kdc_log(context, config, 4,
 397             "sending %lu bytes to %s", (unsigned long)reply->length,
 398             d->addr_string);
 399     if(prependlength){
 400         unsigned char l[4];
 401         l[0] = (reply->length >> 24) & 0xff;
 402         l[1] = (reply->length >> 16) & 0xff;
 403         l[2] = (reply->length >> 8) & 0xff;
 404         l[3] = reply->length & 0xff;
 405         if(rk_IS_SOCKET_ERROR(sendto(d->s, l, sizeof(l), 0, d->sa, d->sock_len))) {
 406             kdc_log (context, config,
 407                      1, "sendto(%s): %s", d->addr_string,
 408                      strerror(rk_SOCK_ERRNO));
 409             return;
 410         }
 411     }
 412     if(rk_IS_SOCKET_ERROR(sendto(d->s, reply->data, reply->length, 0, d->sa, d->sock_len))) {
 413         kdc_log (context, config, 1, "sendto(%s): %s", d->addr_string,
 414                  strerror(rk_SOCK_ERRNO));
 415         return;
 416     }
 417 }
 418
 419 /*
 420  * Handle the request in `buf, len' to socket `d'
 421  */
 422
 423 static void
 424 do_request(krb5_context context,
 425            krb5_kdc_configuration *config,
 426            void *buf, size_t len, krb5_boolean prependlength,
 427            struct descr *d)
 428 {
 429     krb5_error_code ret;
 430     krb5_data reply;
 431     int datagram_reply = (d->type == SOCK_DGRAM);
 432
 433     krb5_kdc_update_time(NULL);
 434
 435     krb5_data_zero(&reply);
 436     ret = krb5_kdc_process_request(context, config,
 437                                    buf, len, &reply, &prependlength,
 438                                    d->addr_string, d->sa,
 439                                    datagram_reply);
 440     if(request_log)
 441         krb5_kdc_save_request(context, request_log, buf, len, &reply, d->sa);
 442     if(reply.length){
 443         send_reply(context, config, prependlength, d, &reply);
 444         krb5_data_free(&reply);
 445     }
 446     if(ret)
 447         kdc_log(context, config, 1,
 448                 "Failed processing %lu byte request from %s",
 449                 (unsigned long)len, d->addr_string);
 450 }
 451
 452 /*
 453  * Handle incoming data to the UDP socket in `d'
 454  */
 455
 456 static void
 457 handle_udp(krb5_context context,
 458            krb5_kdc_configuration *config,
 459            struct descr *d)
 460 {
 461     unsigned char *buf;
 462     ssize_t n;
 463
 464     buf = malloc(max_request_udp);
 465     if (buf == NULL){
 466         kdc_log(context, config, 1, "Failed to allocate %lu bytes",
 467                 (unsigned long)max_request_udp);
 468         return;
 469     }
 470
 471     d->sock_len = sizeof(d->__ss);
 472     n = recvfrom(d->s, buf, max_request_udp, 0, d->sa, &d->sock_len);
 473     if (rk_IS_SOCKET_ERROR(n)) {
 474         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 475             krb5_warn(context, rk_SOCK_ERRNO, "recvfrom");
 476     } else {
 477         addr_to_string (context, d->sa, d->sock_len,
 478                         d->addr_string, sizeof(d->addr_string));
 479         if ((size_t)n == max_request_udp) {
 480             krb5_data data;
 481             krb5_warn(context, errno,
 482                       "recvfrom: truncated packet from %s, asking for TCP",
 483                       d->addr_string);
 484             krb5_mk_error(context,
 485                           KRB5KRB_ERR_RESPONSE_TOO_BIG,
 486                           NULL,
 487                           NULL,
 488                           NULL,
 489                           NULL,
 490                           NULL,
 491                           NULL,
 492                           &data);
 493             send_reply(context, config, FALSE, d, &data);
 494             krb5_data_free(&data);
 495         } else {
 496             do_request(context, config, buf, n, FALSE, d);
 497         }
 498     }
 499     free (buf);
 500 }
 501
 502 static void
 503 clear_descr(struct descr *d)
 504 {
 505     if(d->buf)
 506         memset(d->buf, 0, d->size);
 507     d->len = 0;
 508     if(d->s != rk_INVALID_SOCKET)
 509         rk_closesocket(d->s);
 510     d->s = rk_INVALID_SOCKET;
 511 }
 512
 513
 514 /* remove HTTP %-quoting from buf */
 515 static int
 516 de_http(char *buf)
 517 {
 518     unsigned char *p, *q;
 519     unsigned int x;
 520
 521     for (p = q = (unsigned char *)buf; *p; p++, q++) {
 522         if (*p == '%') {
 523             if (!(isxdigit(p[1]) && isxdigit(p[2])))
 524                 return -1;
 525
 526             if (sscanf((char *)p + 1, "%2x", &x) != 1)
 527                 return -1;
 528
 529             *q = x;
 530             p += 2;
 531         } else {
 532             *q = *p;
 533         }
 534     }
 535     *q = '\0';
 536     return 0;
 537 }
 538
 539 #define TCP_TIMEOUT 4
 540
 541 /*
 542  * accept a new TCP connection on `d[parent]' and store it in `d[child]'
 543  */
 544
 545 static void
 546 add_new_tcp (krb5_context context,
 547              krb5_kdc_configuration *config,
 548              struct descr *d, int parent, int child)
 549 {
 550     krb5_socket_t s;
 551
 552     if (child == -1)
 553         return;
 554
 555     d[child].sock_len = sizeof(d[child].__ss);
 556     s = accept(d[parent].s, d[child].sa, &d[child].sock_len);
 557     if(rk_IS_BAD_SOCKET(s)) {
 558         if (rk_SOCK_ERRNO != EAGAIN && rk_SOCK_ERRNO != EINTR)
 559             krb5_warn(context, rk_SOCK_ERRNO, "accept");
 560         return;
 561     }
 562
 563 #ifdef FD_SETSIZE
 564     if (s >= FD_SETSIZE) {
 565         krb5_warnx(context, "socket FD too large");
 566         rk_closesocket (s);
 567         return;
 568     }
 569 #endif
 570
 571     d[child].s = s;
 572     d[child].timeout = time(NULL) + TCP_TIMEOUT;
 573     d[child].type = SOCK_STREAM;
 574     addr_to_string (context,
 575                     d[child].sa, d[child].sock_len,
 576                     d[child].addr_string, sizeof(d[child].addr_string));
 577 }
 578
 579 /*
 580  * Grow `d' to handle at least `n'.
 581  * Return != 0 if fails
 582  */
 583
 584 static int
 585 grow_descr (krb5_context context,
 586             krb5_kdc_configuration *config,
 587             struct descr *d, size_t n)
 588 {
 589     if (d->size - d->len < n) {
 590         unsigned char *tmp;
 591         size_t grow;
 592
 593         grow = max(1024, d->len + n);
 594         if (d->size + grow > max_request_tcp) {
 595             kdc_log(context, config, 2, "Request exceeds max request size (%lu bytes).",
 596                     (unsigned long)d->size + grow);
 597             clear_descr(d);
 598             return -1;
 599         }
 600         tmp = realloc (d->buf, d->size + grow);
 601         if (tmp == NULL) {
 602             kdc_log(context, config, 1, "Failed to re-allocate %lu bytes.",
 603                     (unsigned long)d->size + grow);
 604             clear_descr(d);
 605             return -1;
 606         }
 607         d->size += grow;
 608         d->buf = tmp;
 609     }
 610     return 0;
 611 }
 612
 613 /*
 614  * Try to handle the TCP data at `d->buf, d->len'.
 615  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 616  */
 617
 618 static int
 619 handle_vanilla_tcp (krb5_context context,
 620                     krb5_kdc_configuration *config,
 621                     struct descr *d)
 622 {
 623     krb5_storage *sp;
 624     uint32_t len;
 625
 626     sp = krb5_storage_from_mem(d->buf, d->len);
 627     if (sp == NULL) {
 628         kdc_log (context, config, 1, "krb5_storage_from_mem failed");
 629         return -1;
 630     }
 631     krb5_ret_uint32(sp, &len);
 632     krb5_storage_free(sp);
 633     if(d->len - 4 >= len) {
 634         memmove(d->buf, d->buf + 4, d->len - 4);
 635         d->len -= 4;
 636         return 1;
 637     }
 638     return 0;
 639 }
 640
 641 /*
 642  * Try to handle the TCP/HTTP data at `d->buf, d->len'.
 643  * Return -1 if failed, 0 if succesful, and 1 if data is complete.
 644  */
 645
 646 static int
 647 handle_http_tcp (krb5_context context,
 648                  krb5_kdc_configuration *config,
 649                  struct descr *d)
 650 {
 651     char *s, *p, *t;
 652     void *data;
 653     char *proto;
 654     int len;
 655
 656     s = (char *)d->buf;
 657
 658     /* If its a multi line query, truncate off the first line */
 659     p = strstr(s, "\r\n");
 660     if (p)
 661         *p = 0;
 662
 663     p = NULL;
 664     t = strtok_r(s, " \t", &p);
 665     if (t == NULL) {
 666         kdc_log(context, config, 2,
 667                 "Missing HTTP operand (GET) request from %s", d->addr_string);
 668         return -1;
 669     }
 670
 671     t = strtok_r(NULL, " \t", &p);
 672     if(t == NULL) {
 673         kdc_log(context, config, 2,
 674                 "Missing HTTP GET data in request from %s", d->addr_string);
 675         return -1;
 676     }
 677
 678     data = malloc(strlen(t));
 679     if (data == NULL) {
 680         kdc_log(context, config, 1, "Failed to allocate %lu bytes",
 681                 (unsigned long)strlen(t));
 682         return -1;
 683     }
 684     if(*t == '/')
 685         t++;
 686     if(de_http(t) != 0) {
 687         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 688         kdc_log(context, config, 4, "HTTP request: %s", t);
 689         free(data);
 690         return -1;
 691     }
 692     proto = strtok_r(NULL, " \t", &p);
 693     if (proto == NULL) {
 694         kdc_log(context, config, 2, "Malformed HTTP request from %s", d->addr_string);
 695         free(data);
 696         return -1;
 697     }
 698     len = rk_base64_decode(t, data);
 699     if(len <= 0){
 700         const char *msg =
 701             " 404 Not found\r\n"
 702             "Server: Heimdal/" VERSION "\r\n"
 703             "Cache-Control: no-cache\r\n"
 704             "Pragma: no-cache\r\n"
 705             "Content-type: text/html\r\n"
 706             "Content-transfer-encoding: 8bit\r\n\r\n"
 707             "<TITLE>404 Not found</TITLE>\r\n"
 708             "<H1>404 Not found</H1>\r\n"
 709             "That page doesn't exist, maybe you are looking for "
 710             "<A HREF=\"http://www.h5l.org/\">Heimdal</A>?\r\n";
 711         kdc_log(context, config, 2, "HTTP request from %s is non KDC request", d->addr_string);
 712         kdc_log(context, config, 4, "HTTP request: %s", t);
 713         free(data);
 714         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 715             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 716                     d->addr_string, strerror(rk_SOCK_ERRNO));
 717             return -1;
 718         }
 719         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 720             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 721                     d->addr_string, strerror(rk_SOCK_ERRNO));
 722             return -1;
 723         }
 724         return -1;
 725     }
 726     {
 727         const char *msg =
 728             " 200 OK\r\n"
 729             "Server: Heimdal/" VERSION "\r\n"
 730             "Cache-Control: no-cache\r\n"
 731             "Pragma: no-cache\r\n"
 732             "Content-type: application/octet-stream\r\n"
 733             "Content-transfer-encoding: binary\r\n\r\n";
 734         if (rk_IS_SOCKET_ERROR(send(d->s, proto, strlen(proto), 0))) {
 735             free(data);
 736             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 737                     d->addr_string, strerror(rk_SOCK_ERRNO));
 738             return -1;
 739         }
 740         if (rk_IS_SOCKET_ERROR(send(d->s, msg, strlen(msg), 0))) {
 741             free(data);
 742             kdc_log(context, config, 1, "HTTP write failed: %s: %s",
 743                     d->addr_string, strerror(rk_SOCK_ERRNO));
 744             return -1;
 745         }
 746     }
 747     if ((size_t)len > d->len)
 748         len = d->len;
 749     memcpy(d->buf, data, len);
 750     d->len = len;
 751     free(data);
 752     return 1;
 753 }
 754
 755 static int
 756 http1_request_taste(const unsigned char *req, size_t len)
 757 {
 758     return !!((len >= sizeof("GET ") - 1 &&
 759                memcmp(req, "GET ", sizeof("GET ") - 1) == 0) ||
 760               (len >= sizeof("HEAD ") - 1 &&
 761                memcmp(req, "HEAD ", sizeof("HEAD ") - 1) == 0));
 762 }
 763
 764 static int
 765 http1_request_is_complete(const unsigned char *req, size_t len)
 766 {
 767
 768     return http1_request_taste(req, len) &&
 769         memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 770
 771     /*
 772      * For POST (the MSFT variant of this protocol) we'll need something like
 773      * this (plus check for Content-Length/Transfer-Encoding):
 774      *
 775      *  const unsigned char *body;
 776      *  if ((body = memmem(req, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4)) == NULL)
 777      *      return 0;
 778      *  body += sizeof("\r\n\r\n") - 4;
 779      *  len -= (body - req);
 780      *  return memmem(body, len, "\r\n\r\n", sizeof("\r\n\r\n") - 4) != NULL;
 781      *
 782      * Since the POST-based variant runs over HTTPS, we'll probably implement
 783      * that in a proxy instead of here.
 784      */
 785 }
 786
 787 /*
 788  * Handle incoming data to the TCP socket in `d[index]'
 789  */
 790
 791 static void
 792 handle_tcp(krb5_context context,
 793            krb5_kdc_configuration *config,
 794            struct descr *d, int idx, int min_free)
 795 {
 796     unsigned char buf[1024];
 797     int n;
 798     int ret = 0;
 799
 800     if (d[idx].timeout == 0) {
 801         add_new_tcp (context, config, d, idx, min_free);
 802         return;
 803     }
 804
 805     n = recvfrom(d[idx].s, buf, sizeof(buf), 0, NULL, NULL);
 806     if(rk_IS_SOCKET_ERROR(n)){
 807         krb5_warn(context, rk_SOCK_ERRNO, "recvfrom failed from %s to %s/%d",
 808                   d[idx].addr_string, descr_type(d + idx),
 809                   ntohs(d[idx].port));
 810         return;
 811     } else if (n == 0) {
 812         krb5_warnx(context, "connection closed before end of data after %lu "
 813                    "bytes from %s to %s/%d", (unsigned long)d[idx].len,
 814                    d[idx].addr_string, descr_type(d + idx),
 815                    ntohs(d[idx].port));
 816         clear_descr (d + idx);
 817         return;
 818     }
 819     if (grow_descr (context, config, &d[idx], n))
 820         return;
 821     memcpy(d[idx].buf + d[idx].len, buf, n);
 822     d[idx].len += n;
 823     if(d[idx].len > 4 && d[idx].buf[0] == 0) {
 824         ret = handle_vanilla_tcp (context, config, &d[idx]);
 825     } else if (enable_http &&
 826                http1_request_taste(d[idx].buf, d[idx].len)) {
 827
 828         if (http1_request_is_complete(d[idx].buf, d[idx].len)) {
 829             /* NUL-terminate at the request header ending \r\n\r\n */
 830             d[idx].buf[d[idx].len - 4] = '\0';
 831             ret = handle_http_tcp (context, config, &d[idx]);
 832         }
 833     } else if (d[idx].len > 4) {
 834         kdc_log (context, config,
 835                  2, "TCP data of strange type from %s to %s/%d",
 836                  d[idx].addr_string, descr_type(d + idx),
 837                  ntohs(d[idx].port));
 838         if (d[idx].buf[0] & 0x80) {
 839             krb5_data reply;
 840
 841             kdc_log (context, config, 2, "TCP extension not supported");
 842
 843             ret = krb5_mk_error(context,
 844                                 KRB5KRB_ERR_FIELD_TOOLONG,
 845                                 NULL,
 846                                 NULL,
 847                                 NULL,
 848                                 NULL,
 849                                 NULL,
 850                                 NULL,
 851                                 &reply);
 852             if (ret == 0) {
 853                 send_reply(context, config, TRUE, d + idx, &reply);
 854                 krb5_data_free(&reply);
 855             }
 856         }
 857         clear_descr(d + idx);
 858         return;
 859     }
 860
 861     /*
 862      * ret == 0 -> not enough of request buffered -> wait for more
 863      * ret == 1 -> go ahead and perform the request
 864      * ret != 0 (really, < 0) -> error, probably ENOMEM, close connection
 865      */
 866     if (ret == 1)
 867         do_request(context, config,
 868                    d[idx].buf, d[idx].len, TRUE, &d[idx]);
 869
 870     /*
 871      * Note: this means we don't keep the connection open even where we
 872      * the protocol permits it.
 873      */
 874     if (ret != 0)
 875         clear_descr(d + idx);
 876 }
 877
 878 #ifdef HAVE_FORK
 879 static void
 880 handle_islive(int fd)
 881 {
 882     char buf;
 883     int ret;
 884
 885     ret = read(fd, &buf, 1);
 886     if (ret != 1)
 887         exit_flag = -1;
 888 }
 889 #endif
 890
 891 static krb5_boolean
 892 realloc_descrs(struct descr **d, unsigned int *ndescr)
 893 {
 894     struct descr *tmp;
 895     size_t i;
 896
 897     tmp = realloc(*d, (*ndescr + 4) * sizeof(**d));
 898     if(tmp == NULL)
 899         return FALSE;
 900
 901     *d = tmp;
 902     reinit_descrs (*d, *ndescr);
 903     memset(*d + *ndescr, 0, 4 * sizeof(**d));
 904     for(i = *ndescr; i < *ndescr + 4; i++)
 905         init_descr (*d + i);
 906
 907     *ndescr += 4;
 908
 909     return TRUE;
 910 }
 911
 912 static int
 913 next_min_free(krb5_context context, struct descr **d, unsigned int *ndescr)
 914 {
 915     size_t i;
 916     int min_free;
 917
 918     for(i = 0; i < *ndescr; i++) {
 919         int s = (*d + i)->s;
 920         if(rk_IS_BAD_SOCKET(s))
 921             return i;
 922     }
 923
 924     min_free = *ndescr;
 925     if(!realloc_descrs(d, ndescr)) {
 926         min_free = -1;
 927         krb5_warnx(context, "No memory");
 928     }
 929
 930     return min_free;
 931 }
 932
 933 static void
 934 loop(krb5_context context, krb5_kdc_configuration *config,
 935      struct descr **dp, unsigned int *ndescrp, int islive)
 936 {
 937     struct descr *d = *dp;
 938     unsigned int ndescr = *ndescrp;
 939
 940     while (exit_flag == 0) {
 941         struct timeval tmout;
 942         fd_set fds;
 943         int min_free = -1;
 944         int max_fd = 0;
 945         size_t i;
 946
 947         FD_ZERO(&fds);
 948         if (islive > -1) {
 949             FD_SET(islive, &fds);
 950             max_fd = islive;
 951         }
 952         for (i = 0; i < ndescr; i++) {
 953             if (!rk_IS_BAD_SOCKET(d[i].s)) {
 954                 if (d[i].type == SOCK_STREAM &&
 955                    d[i].timeout && d[i].timeout < time(NULL)) {
 956                     kdc_log(context, config, 2,
 957                             "TCP-connection from %s expired after %lu bytes",
 958                             d[i].addr_string, (unsigned long)d[i].len);
 959                     clear_descr(&d[i]);
 960                     continue;
 961                 }
 962 #ifndef NO_LIMIT_FD_SETSIZE
 963                 if (max_fd < d[i].s)
 964                     max_fd = d[i].s;
 965 #ifdef FD_SETSIZE
 966                 if (max_fd >= FD_SETSIZE)
 967                     krb5_errx(context, 1, "fd too large");
 968 #endif
 969 #endif
 970                 FD_SET(d[i].s, &fds);
 971             }
 972         }
 973
 974         tmout.tv_sec = TCP_TIMEOUT;
 975         tmout.tv_usec = 0;
 976         switch(select(max_fd + 1, &fds, 0, 0, &tmout)){
 977         case 0:
 978             break;
 979         case -1:
 980             if (errno != EINTR)
 981                 krb5_warn(context, rk_SOCK_ERRNO, "select");
 982             break;
 983         default:
 984 #ifdef HAVE_FORK
 985             if (islive > -1 && FD_ISSET(islive, &fds))
 986                 handle_islive(islive);
 987 #endif
 988             for (i = 0; i < ndescr; i++)
 989                 if (!rk_IS_BAD_SOCKET(d[i].s) && FD_ISSET(d[i].s, &fds)) {
 990                     min_free = next_min_free(context, dp, ndescrp);
 991                     ndescr = *ndescrp;
 992                     d = *dp;
 993
 994                     if (d[i].type == SOCK_DGRAM)
 995                         handle_udp(context, config, &d[i]);
 996                     else if (d[i].type == SOCK_STREAM)
 997                         handle_tcp(context, config, d, i, min_free);
 998                 }
 999         }
1000     }
1001
1002     switch (exit_flag) {
1003     case -1:
1004         kdc_log(context, config, 0,
1005                 "KDC worker process exiting because KDC master exited.");
1006         break;
1007 #ifdef SIGXCPU
1008     case SIGXCPU:
1009         kdc_log(context, config, 0, "CPU time limit exceeded");
1010         break;
1011 #endif
1012     case SIGINT:
1013     case SIGTERM:
1014         kdc_log(context, config, 0, "Terminated");
1015         break;
1016     default:
1017         kdc_log(context, config, 0, "Unexpected exit reason: %d", exit_flag);
1018         break;
1019     }
1020 }
1021
1022 #ifdef __APPLE__
1023 static void
1024 bonjour_kid(krb5_context context, krb5_kdc_configuration *config, const char *argv0, int *islive)
1025 {
1026     char buf;
1027
1028     if (do_bonjour > 0) {
1029         bonjour_announce(context, config);
1030
1031         while (read(0, &buf, 1) == 1)
1032             continue;
1033         _exit(0);
1034     }
1035
1036     if ((bonjour_pid = fork()) != 0)
1037         return;
1038
1039     close(islive[0]);
1040     if (dup2(islive[1], 0) == -1)
1041         err(1, "failed to announce with bonjour (dup)");
1042     if (islive[1] != 0)
1043         close(islive[1]);
1044     execlp(argv0, "kdc", "--bonjour", NULL);
1045     err(1, "failed to announce with bonjour (exec)");
1046 }
1047 #endif
1048
1049 #ifdef HAVE_FORK
1050 static void
1051 kill_kids(pid_t *pids, int max_kids, int sig)
1052 {
1053     int i;
1054
1055     for (i=0; i < max_kids; i++)
1056         if (pids[i] > 0)
1057             kill(sig, pids[i]);
1058     if (bonjour_pid > 0)
1059         kill(sig, bonjour_pid);
1060 }
1061
1062 static int
1063 reap_kid(krb5_context context, krb5_kdc_configuration *config,
1064          pid_t *pids, int max_kids, int options)
1065 {
1066     pid_t pid;
1067     char *what = "untracked";
1068     int status;
1069     int i = 0; /* quiet warnings */
1070     int ret = 0;
1071     int level = 3;
1072     const char *sev = "info: ";
1073
1074     pid = waitpid(-1, &status, options);
1075     if (pid <= 0)
1076         return 0;
1077
1078     if (pid == bonjour_pid) {
1079         bonjour_pid = (pid_t)-1;
1080         what = "bonjour";
1081     } else {
1082         for (i=0; i < max_kids; i++) {
1083             if (pids[i] == pid) {
1084                 pids[i] = (pid_t)-1;
1085                 what = "worker";
1086                 ret = 1;
1087                 break;
1088             }
1089         }
1090
1091         if (i == max_kids) {
1092             /* should not happen */
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 }