source4/kdc/kdc.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    KDC Server startup
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   7    Copyright (C) Andrew Tridgell        2005
   8    Copyright (C) Stefan Metzmacher      2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "smbd/service_task.h"
  27 #include "smbd/service_stream.h"
  28 #include "lib/events/events.h"
  29 #include "lib/socket/socket.h"
  30 #include "kdc/kdc.h"
  31 #include "system/network.h"
  32 #include "dlinklist.h"
  33 #include "lib/messaging/irpc.h"
  34 #include "lib/stream/packet.h"
  35
  36 /* hold all the info needed to send a reply */
  37 struct kdc_reply {
  38         struct kdc_reply *next, *prev;
  39         const char *dest_address;
  40         int dest_port;
  41         DATA_BLOB packet;
  42 };
  43
  44 typedef BOOL (*kdc_process_fn_t)(struct kdc_server *kdc,
  45                                  TALLOC_CTX *mem_ctx,
  46                                  DATA_BLOB *input,
  47                                  DATA_BLOB *reply,
  48                                  const char *peer_address, int peer_port,
  49                                  const char *my_address, int my_port);
  50
  51 /* hold information about one kdc socket */
  52 struct kdc_socket {
  53         struct socket_context *sock;
  54         struct kdc_server *kdc;
  55         struct fd_event *fde;
  56
  57         /* a queue of outgoing replies that have been deferred */
  58         struct kdc_reply *send_queue;
  59
  60         kdc_process_fn_t process;
  61 };
  62 /*
  63   state of an open tcp connection
  64 */
  65 struct kdc_tcp_connection {
  66         /* stream connection we belong to */
  67         struct stream_connection *conn;
  68
  69         /* the kdc_server the connection belongs to */
  70         struct kdc_server *kdc;
  71
  72         struct packet_context *packet;
  73
  74         kdc_process_fn_t process;
  75 };
  76
  77 /*
  78   handle fd send events on a KDC socket
  79 */
  80 static void kdc_send_handler(struct kdc_socket *kdc_socket)
  81 {
  82         while (kdc_socket->send_queue) {
  83                 struct kdc_reply *rep = kdc_socket->send_queue;
  84                 NTSTATUS status;
  85                 size_t sendlen;
  86
  87                 status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, 0,
  88                                        rep->dest_address, rep->dest_port);
  89                 if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
  90                         break;
  91                 }
  92                 if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_BUFFER_SIZE)) {
  93                         /* Replace with a krb err, response to big */
  94                 }
  95
  96                 DLIST_REMOVE(kdc_socket->send_queue, rep);
  97                 talloc_free(rep);
  98         }
  99
 100         if (kdc_socket->send_queue == NULL) {
 101                 EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
 102         }
 103 }
 104
 105
 106 /*
 107   handle fd recv events on a KDC socket
 108 */
 109 static void kdc_recv_handler(struct kdc_socket *kdc_socket)
 110 {
 111         NTSTATUS status;
 112         TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
 113         DATA_BLOB blob;
 114         struct kdc_reply *rep;
 115         DATA_BLOB reply;
 116         size_t nread, dsize;
 117         const char *src_addr;
 118         int src_port;
 119         const char *my_addr;
 120         int my_port;
 121         int ret;
 122
 123         status = socket_pending(kdc_socket->sock, &dsize);
 124         if (!NT_STATUS_IS_OK(status)) {
 125                 talloc_free(tmp_ctx);
 126                 return;
 127         }
 128
 129         blob = data_blob_talloc(kdc_socket, NULL, dsize);
 130         if (blob.data == NULL) {
 131                 /* hope this is a temporary low memory condition */
 132                 talloc_free(tmp_ctx);
 133                 return;
 134         }
 135
 136         status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
 137                                  &src_addr, &src_port);
 138         if (!NT_STATUS_IS_OK(status)) {
 139                 talloc_free(tmp_ctx);
 140                 return;
 141         }
 142         talloc_steal(tmp_ctx, src_addr);
 143         blob.length = nread;
 144
 145         DEBUG(10,("Received krb5 UDP packet of length %lu from %s:%u\n",
 146                  (long)blob.length, src_addr, (uint16_t)src_port));
 147
 148         my_addr = socket_get_my_addr(kdc_socket->sock, tmp_ctx);
 149         if (!my_addr) {
 150                 talloc_free(tmp_ctx);
 151                 return;
 152         }
 153         my_port = socket_get_my_port(kdc_socket->sock);
 154
 155
 156         /* Call krb5 */
 157         ret = kdc_socket->process(kdc_socket->kdc,
 158                                   tmp_ctx,
 159                                   &blob,
 160                                   &reply,
 161                                   src_addr, src_port,
 162                                   my_addr, my_port);
 163         if (!ret) {
 164                 talloc_free(tmp_ctx);
 165                 return;
 166         }
 167
 168         /* queue a pending reply */
 169         rep = talloc(kdc_socket, struct kdc_reply);
 170         if (rep == NULL) {
 171                 talloc_free(tmp_ctx);
 172                 return;
 173         }
 174         rep->dest_address = talloc_steal(rep, src_addr);
 175         rep->dest_port    = src_port;
 176         rep->packet       = reply;
 177         talloc_steal(rep, reply.data);
 178
 179         if (rep->packet.data == NULL) {
 180                 talloc_free(rep);
 181                 talloc_free(tmp_ctx);
 182                 return;
 183         }
 184
 185         DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
 186         EVENT_FD_WRITEABLE(kdc_socket->fde);
 187         talloc_free(tmp_ctx);
 188 }
 189
 190 /*
 191   handle fd events on a KDC socket
 192 */
 193 static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
 194                                uint16_t flags, void *private)
 195 {
 196         struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
 197         if (flags & EVENT_FD_WRITE) {
 198                 kdc_send_handler(kdc_socket);
 199         }
 200         if (flags & EVENT_FD_READ) {
 201                 kdc_recv_handler(kdc_socket);
 202         }
 203 }
 204
 205 static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
 206 {
 207         stream_terminate_connection(kdcconn->conn, reason);
 208 }
 209
 210 /*
 211   receive a full packet on a KDC connection
 212 */
 213 static NTSTATUS kdc_tcp_recv(void *private, DATA_BLOB blob)
 214 {
 215         struct kdc_tcp_connection *kdcconn = talloc_get_type(private,
 216                                                              struct kdc_tcp_connection);
 217         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
 218         TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
 219         int ret;
 220         DATA_BLOB input, reply;
 221         const char *src_addr;
 222         int src_port;
 223         const char *my_addr;
 224         int my_port;
 225
 226         talloc_steal(tmp_ctx, blob.data);
 227
 228         src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
 229         if (!src_addr) {
 230                 talloc_free(tmp_ctx);
 231                 return NT_STATUS_NO_MEMORY;
 232         }
 233         src_port = socket_get_my_port(kdcconn->conn->socket);
 234
 235         my_addr = socket_get_my_addr(kdcconn->conn->socket, tmp_ctx);
 236         if (!my_addr) {
 237                 talloc_free(tmp_ctx);
 238                 return NT_STATUS_NO_MEMORY;
 239         }
 240         my_port = socket_get_my_port(kdcconn->conn->socket);
 241
 242         /* Call krb5 */
 243         input = data_blob_const(blob.data + 4, blob.length - 4);
 244
 245         ret = kdcconn->process(kdcconn->kdc,
 246                                tmp_ctx,
 247                                &input,
 248                                &reply,
 249                                src_addr, src_port,
 250                                my_addr, my_port);
 251         if (!ret) {
 252                 talloc_free(tmp_ctx);
 253                 return NT_STATUS_INTERNAL_ERROR;
 254         }
 255
 256         /* and now encode the reply */
 257         blob = data_blob_talloc(kdcconn, NULL, reply.length + 4);
 258         if (!blob.data) {
 259                 talloc_free(tmp_ctx);
 260                 return NT_STATUS_NO_MEMORY;
 261         }
 262
 263         RSIVAL(blob.data, 0, reply.length);
 264         memcpy(blob.data + 4, reply.data, reply.length);
 265
 266         status = packet_send(kdcconn->packet, blob);
 267         if (!NT_STATUS_IS_OK(status)) {
 268                 talloc_free(tmp_ctx);
 269                 return status;
 270         }
 271
 272         /* the call isn't needed any more */
 273         talloc_free(tmp_ctx);
 274         return NT_STATUS_OK;
 275 }
 276
 277 /*
 278   receive some data on a KDC connection
 279 */
 280 static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags)
 281 {
 282         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 283                                                              struct kdc_tcp_connection);
 284         packet_recv(kdcconn->packet);
 285 }
 286
 287 /*
 288   called on a tcp recv error
 289 */
 290 static void kdc_tcp_recv_error(void *private, NTSTATUS status)
 291 {
 292         struct kdc_tcp_connection *kdcconn = talloc_get_type(private, struct kdc_tcp_connection);
 293         kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
 294 }
 295
 296 /*
 297   called when we can write to a connection
 298 */
 299 static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
 300 {
 301         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 302                                                              struct kdc_tcp_connection);
 303         packet_queue_run(kdcconn->packet);
 304 }
 305
 306 /**
 307    Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
 308    calling conventions
 309 */
 310
 311 static BOOL kdc_process(struct kdc_server *kdc,
 312                         TALLOC_CTX *mem_ctx,
 313                         DATA_BLOB *input,
 314                         DATA_BLOB *reply,
 315                         const char *peer_addr,
 316                         int peer_port,
 317                         const char *my_addr,
 318                         int my_port)
 319 {
 320         int ret;
 321         krb5_data k5_reply;
 322         struct ipv4_addr addr;
 323         struct sockaddr_in peer_sock_addr;
 324
 325         /* TODO:  This really should be in a utility function somewhere */
 326         ZERO_STRUCT(peer_sock_addr);
 327 #ifdef HAVE_SOCK_SIN_LEN
 328         peer_sock_addr.sin_len          = sizeof(peer_sock_addr);
 329 #endif
 330         addr                            = interpret_addr2(peer_addr);
 331         peer_sock_addr.sin_addr.s_addr  = addr.addr;
 332         peer_sock_addr.sin_port         = htons(peer_port);
 333         peer_sock_addr.sin_family       = PF_INET;
 334
 335         DEBUG(10,("Received KDC packet of length %lu from %s\n",
 336                  (long)input->length - 4, peer_addr));
 337
 338         ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context,
 339                                             kdc->config,
 340                                             input->data, input->length,
 341                                             &k5_reply,
 342                                             peer_addr,
 343                                             (struct sockaddr *)&peer_sock_addr);
 344         if (ret == -1) {
 345                 *reply = data_blob(NULL, 0);
 346                 return False;
 347         }
 348         *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
 349         krb5_data_free(&k5_reply);
 350         return True;
 351 }
 352
 353 /*
 354   called when we get a new connection
 355 */
 356 static void kdc_tcp_generic_accept(struct stream_connection *conn, kdc_process_fn_t process_fn)
 357 {
 358         struct kdc_server *kdc = talloc_get_type(conn->private, struct kdc_server);
 359         struct kdc_tcp_connection *kdcconn;
 360
 361         kdcconn = talloc_zero(conn, struct kdc_tcp_connection);
 362         if (!kdcconn) {
 363                 stream_terminate_connection(conn, "kdc_tcp_accept: out of memory");
 364                 return;
 365         }
 366         kdcconn->conn    = conn;
 367         kdcconn->kdc     = kdc;
 368         kdcconn->process = process_fn;
 369         conn->private    = kdcconn;
 370
 371         kdcconn->packet = packet_init(kdcconn);
 372         if (kdcconn->packet == NULL) {
 373                 kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_accept: out of memory");
 374                 return;
 375         }
 376         packet_set_private(kdcconn->packet, kdcconn);
 377         packet_set_socket(kdcconn->packet, conn->socket);
 378         packet_set_callback(kdcconn->packet, kdc_tcp_recv);
 379         packet_set_full_request(kdcconn->packet, packet_full_request_u32);
 380         packet_set_error_handler(kdcconn->packet, kdc_tcp_recv_error);
 381         packet_set_event_context(kdcconn->packet, conn->event.ctx);
 382         packet_set_fde(kdcconn->packet, conn->event.fde);
 383         packet_set_serialise(kdcconn->packet);
 384 }
 385
 386 static void kdc_tcp_accept(struct stream_connection *conn)
 387 {
 388         kdc_tcp_generic_accept(conn, kdc_process);
 389 }
 390
 391 static const struct stream_server_ops kdc_tcp_stream_ops = {
 392         .name                   = "kdc_tcp",
 393         .accept_connection      = kdc_tcp_accept,
 394         .recv_handler           = kdc_tcp_recv_handler,
 395         .send_handler           = kdc_tcp_send
 396 };
 397
 398 static void kpasswdd_tcp_accept(struct stream_connection *conn)
 399 {
 400         kdc_tcp_generic_accept(conn, kpasswdd_process);
 401 }
 402
 403 static const struct stream_server_ops kpasswdd_tcp_stream_ops = {
 404         .name                   = "kpasswdd_tcp",
 405         .accept_connection      = kpasswdd_tcp_accept,
 406         .recv_handler           = kdc_tcp_recv_handler,
 407         .send_handler           = kdc_tcp_send
 408 };
 409
 410 /*
 411   start listening on the given address
 412 */
 413 static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
 414 {
 415         const struct model_ops *model_ops;
 416         struct kdc_socket *kdc_socket;
 417         struct kdc_socket *kpasswd_socket;
 418         NTSTATUS status;
 419         uint16_t kdc_port = lp_krb5_port();
 420         uint16_t kpasswd_port = lp_kpasswd_port();
 421
 422         kdc_socket = talloc(kdc, struct kdc_socket);
 423         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 424
 425         kpasswd_socket = talloc(kdc, struct kdc_socket);
 426         NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket);
 427
 428         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
 429         if (!NT_STATUS_IS_OK(status)) {
 430                 talloc_free(kdc_socket);
 431                 return status;
 432         }
 433
 434         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0);
 435         if (!NT_STATUS_IS_OK(status)) {
 436                 talloc_free(kpasswd_socket);
 437                 return status;
 438         }
 439
 440         kdc_socket->kdc = kdc;
 441         kdc_socket->send_queue = NULL;
 442         kdc_socket->process = kdc_process;
 443
 444         talloc_steal(kdc_socket, kdc_socket->sock);
 445
 446         kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 447                                        socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
 448                                        kdc_socket_handler, kdc_socket);
 449
 450         status = socket_listen(kdc_socket->sock, address, kdc_port, 0, 0);
 451         if (!NT_STATUS_IS_OK(status)) {
 452                 DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n",
 453                          address, kdc_port, nt_errstr(status)));
 454                 talloc_free(kdc_socket);
 455                 return status;
 456         }
 457
 458         kpasswd_socket->kdc = kdc;
 459         kpasswd_socket->send_queue = NULL;
 460         kpasswd_socket->process = kpasswdd_process;
 461
 462         talloc_steal(kpasswd_socket, kpasswd_socket->sock);
 463
 464         kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 465                                            socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ,
 466                                            kdc_socket_handler, kpasswd_socket);
 467
 468         status = socket_listen(kpasswd_socket->sock, address, kpasswd_port, 0, 0);
 469         if (!NT_STATUS_IS_OK(status)) {
 470                 DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n",
 471                          address, kpasswd_port, nt_errstr(status)));
 472                 talloc_free(kpasswd_socket);
 473                 return status;
 474         }
 475
 476         /* within the kdc task we want to be a single process, so
 477            ask for the single process model ops and pass these to the
 478            stream_setup_socket() call. */
 479         model_ops = process_model_byname("single");
 480         if (!model_ops) {
 481                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 482                 talloc_free(kdc_socket);
 483                 return NT_STATUS_INTERNAL_ERROR;
 484         }
 485
 486         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 487                                      &kdc_tcp_stream_ops,
 488                                      "ip", address, &kdc_port, kdc);
 489         if (!NT_STATUS_IS_OK(status)) {
 490                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 491                          address, kdc_port, nt_errstr(status)));
 492                 talloc_free(kdc_socket);
 493                 return status;
 494         }
 495
 496         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 497                                      &kpasswdd_tcp_stream_ops,
 498                                      "ip", address, &kpasswd_port, kdc);
 499         if (!NT_STATUS_IS_OK(status)) {
 500                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 501                          address, kpasswd_port, nt_errstr(status)));
 502                 talloc_free(kdc_socket);
 503                 return status;
 504         }
 505
 506         return NT_STATUS_OK;
 507 }
 508
 509
 510 /*
 511   setup our listening sockets on the configured network interfaces
 512 */
 513 static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
 514 {
 515         int num_interfaces = iface_count();
 516         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 517         NTSTATUS status;
 518
 519         /* if we are allowing incoming packets from any address, then
 520            we need to bind to the wildcard address */
 521         if (!lp_bind_interfaces_only()) {
 522                 status = kdc_add_socket(kdc, "0.0.0.0");
 523                 NT_STATUS_NOT_OK_RETURN(status);
 524         } else {
 525                 int i;
 526
 527                 for (i=0; i<num_interfaces; i++) {
 528                         const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
 529                         status = kdc_add_socket(kdc, address);
 530                         NT_STATUS_NOT_OK_RETURN(status);
 531                 }
 532         }
 533
 534         talloc_free(tmp_ctx);
 535
 536         return NT_STATUS_OK;
 537 }
 538
 539 /*
 540   startup the kdc task
 541 */
 542 static void kdc_task_init(struct task_server *task)
 543 {
 544         struct kdc_server *kdc;
 545         NTSTATUS status;
 546         krb5_error_code ret;
 547
 548         if (iface_count() == 0) {
 549                 task_server_terminate(task, "kdc: no network interfaces configured");
 550                 return;
 551         }
 552
 553         kdc = talloc(task, struct kdc_server);
 554         if (kdc == NULL) {
 555                 task_server_terminate(task, "kdc: out of memory");
 556                 return;
 557         }
 558
 559         kdc->task = task;
 560
 561         /* Setup the KDC configuration */
 562         kdc->config = talloc(kdc, krb5_kdc_configuration);
 563         if (!kdc->config) {
 564                 task_server_terminate(task, "kdc: out of memory");
 565                 return;
 566         }
 567         krb5_kdc_default_config(kdc->config);
 568
 569         initialize_krb5_error_table();
 570
 571         ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
 572         if (ret) {
 573                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 574                          error_message(ret)));
 575                 task_server_terminate(task, "kdc: krb5_init_context failed");
 576                 return;
 577         }
 578
 579         krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
 580
 581         kdc->config->logf = kdc->smb_krb5_context->logf;
 582         kdc->config->db = talloc(kdc->config, struct HDB *);
 583         if (!kdc->config->db) {
 584                 task_server_terminate(task, "kdc: out of memory");
 585                 return;
 586         }
 587         kdc->config->num_db = 1;
 588
 589         status = hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context,
 590                                    &kdc->config->db[0], NULL);
 591         if (!NT_STATUS_IS_OK(status)) {
 592                 task_server_terminate(task, "kdc: hdb_ldb_create (setup KDC database) failed");
 593                 return;
 594         }
 595
 596         /* start listening on the configured network interfaces */
 597         status = kdc_startup_interfaces(kdc);
 598         if (!NT_STATUS_IS_OK(status)) {
 599                 task_server_terminate(task, "kdc failed to setup interfaces");
 600                 return;
 601         }
 602
 603         irpc_add_name(task->msg_ctx, "kdc_server");
 604 }
 605
 606
 607 /*
 608   called on startup of the KDC service
 609 */
 610 static NTSTATUS kdc_init(struct event_context *event_ctx,
 611                          const struct model_ops *model_ops)
 612 {
 613         return task_server_startup(event_ctx, model_ops, kdc_task_init);
 614 }
 615
 616 /* called at smbd startup - register ourselves as a server service */
 617 NTSTATUS server_service_kdc_init(void)
 618 {
 619         return register_server_service("kdc", kdc_init);
 620 }