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 *src_addr,
  49                                  int src_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         int ret;
 120
 121         status = socket_pending(kdc_socket->sock, &dsize);
 122         if (!NT_STATUS_IS_OK(status)) {
 123                 talloc_free(tmp_ctx);
 124                 return;
 125         }
 126
 127         blob = data_blob_talloc(kdc_socket, NULL, dsize);
 128         if (blob.data == NULL) {
 129                 /* hope this is a temporary low memory condition */
 130                 talloc_free(tmp_ctx);
 131                 return;
 132         }
 133
 134         status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
 135                                  &src_addr, &src_port);
 136         if (!NT_STATUS_IS_OK(status)) {
 137                 talloc_free(tmp_ctx);
 138                 return;
 139         }
 140         talloc_steal(tmp_ctx, src_addr);
 141         blob.length = nread;
 142
 143         DEBUG(2,("Received krb5 UDP packet of length %lu from %s:%u\n",
 144                  (long)blob.length, src_addr, (uint16_t)src_port));
 145
 146         /* Call krb5 */
 147         ret = kdc_socket->process(kdc_socket->kdc,
 148                                   tmp_ctx,
 149                                   &blob,
 150                                   &reply,
 151                                   src_addr, src_port);
 152         if (!ret) {
 153                 talloc_free(tmp_ctx);
 154                 return;
 155         }
 156
 157         /* queue a pending reply */
 158         rep = talloc(kdc_socket, struct kdc_reply);
 159         if (rep == NULL) {
 160                 talloc_free(tmp_ctx);
 161                 return;
 162         }
 163         rep->dest_address = talloc_steal(rep, src_addr);
 164         rep->dest_port    = src_port;
 165         rep->packet       = reply;
 166         talloc_steal(rep, reply.data);
 167
 168         if (rep->packet.data == NULL) {
 169                 talloc_free(rep);
 170                 talloc_free(tmp_ctx);
 171                 return;
 172         }
 173
 174         DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
 175         EVENT_FD_WRITEABLE(kdc_socket->fde);
 176         talloc_free(tmp_ctx);
 177 }
 178
 179 /*
 180   handle fd events on a KDC socket
 181 */
 182 static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
 183                                uint16_t flags, void *private)
 184 {
 185         struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
 186         if (flags & EVENT_FD_WRITE) {
 187                 kdc_send_handler(kdc_socket);
 188         }
 189         if (flags & EVENT_FD_READ) {
 190                 kdc_recv_handler(kdc_socket);
 191         }
 192 }
 193
 194 static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
 195 {
 196         stream_terminate_connection(kdcconn->conn, reason);
 197 }
 198
 199 /*
 200   receive a full packet on a KDC connection
 201 */
 202 static NTSTATUS kdc_tcp_recv(void *private, DATA_BLOB blob)
 203 {
 204         struct kdc_tcp_connection *kdcconn = talloc_get_type(private,
 205                                                              struct kdc_tcp_connection);
 206         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
 207         TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
 208         const char *src_addr;
 209         int src_port;
 210         int ret;
 211         DATA_BLOB input, reply;
 212
 213         talloc_steal(tmp_ctx, blob.data);
 214
 215         src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
 216         if (!src_addr) goto nomem;
 217         src_port = socket_get_peer_port(kdcconn->conn->socket);
 218
 219         DEBUG(2,("Received krb5 TCP packet of length %lu from %s:%u\n",
 220                  (long)blob.length - 4, src_addr, src_port));
 221
 222         /* Call krb5 */
 223         input = data_blob_const(blob.data + 4, blob.length - 4);
 224
 225         ret = kdcconn->process(kdcconn->kdc,
 226                                tmp_ctx,
 227                                &input,
 228                                &reply,
 229                                src_addr, src_port);
 230         if (!ret) {
 231                 status = NT_STATUS_INTERNAL_ERROR;
 232                 goto failed;
 233         }
 234
 235         /* and now encode the reply */
 236         blob = data_blob_talloc(kdcconn, NULL, reply.length + 4);
 237         if (!blob.data) {
 238                 goto nomem;
 239         }
 240
 241         RSIVAL(blob.data, 0, reply.length);
 242         memcpy(blob.data + 4, reply.data, reply.length);
 243
 244         status = packet_send(kdcconn->packet, blob);
 245         if (!NT_STATUS_IS_OK(status)) {
 246                 goto failed;
 247         }
 248
 249         /* the call isn't needed any more */
 250         talloc_free(tmp_ctx);
 251         return NT_STATUS_OK;
 252 nomem:
 253         status = NT_STATUS_NO_MEMORY;
 254
 255 failed:
 256         return status;
 257 }
 258
 259 /*
 260   receive some data on a KDC connection
 261 */
 262 static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags)
 263 {
 264         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 265                                                              struct kdc_tcp_connection);
 266         packet_recv(kdcconn->packet);
 267 }
 268
 269 /*
 270   called on a tcp recv error
 271 */
 272 static void kdc_tcp_recv_error(void *private, NTSTATUS status)
 273 {
 274         struct kdc_tcp_connection *kdcconn = talloc_get_type(private, struct kdc_tcp_connection);
 275         kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
 276 }
 277
 278 /*
 279   called when we can write to a connection
 280 */
 281 static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
 282 {
 283         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 284                                                              struct kdc_tcp_connection);
 285         packet_queue_run(kdcconn->packet);
 286 }
 287
 288 /**
 289    Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
 290    calling conventions
 291 */
 292
 293 static BOOL kdc_process(struct kdc_server *kdc,
 294                         TALLOC_CTX *mem_ctx,
 295                         DATA_BLOB *input,
 296                         DATA_BLOB *reply,
 297                         const char *src_addr,
 298                         int src_port)
 299 {
 300         int ret;
 301         krb5_data k5_reply;
 302         struct ipv4_addr addr;
 303         struct sockaddr_in src_sock_addr;
 304
 305         /* TODO:  This really should be in a utility function somewhere */
 306         ZERO_STRUCT(src_sock_addr);
 307 #ifdef HAVE_SOCK_SIN_LEN
 308         src_sock_addr.sin_len           = sizeof(src_sock_addr);
 309 #endif
 310         addr                            = interpret_addr2(src_addr);
 311         src_sock_addr.sin_addr.s_addr   = addr.addr;
 312         src_sock_addr.sin_port          = htons(src_port);
 313         src_sock_addr.sin_family        = PF_INET;
 314
 315
 316         ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context,
 317                                             kdc->config,
 318                                             input->data, input->length,
 319                                             &k5_reply,
 320                                             src_addr,
 321                                             (struct sockaddr *)&src_sock_addr);
 322         if (ret == -1) {
 323                 *reply = data_blob(NULL, 0);
 324                 return False;
 325         }
 326         *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
 327         krb5_data_free(&k5_reply);
 328         return True;
 329 }
 330
 331 /*
 332   called when we get a new connection
 333 */
 334 static void kdc_tcp_generic_accept(struct stream_connection *conn, kdc_process_fn_t process_fn)
 335 {
 336         struct kdc_server *kdc = talloc_get_type(conn->private, struct kdc_server);
 337         struct kdc_tcp_connection *kdcconn;
 338
 339         kdcconn = talloc_zero(conn, struct kdc_tcp_connection);
 340         if (!kdcconn) {
 341                 stream_terminate_connection(conn, "kdc_tcp_accept: out of memory");
 342                 return;
 343         }
 344         kdcconn->conn    = conn;
 345         kdcconn->kdc     = kdc;
 346         kdcconn->process = process_fn;
 347         conn->private    = kdcconn;
 348
 349         kdcconn->packet = packet_init(kdcconn);
 350         if (kdcconn->packet == NULL) {
 351                 kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_accept: out of memory");
 352                 return;
 353         }
 354         packet_set_private(kdcconn->packet, kdcconn);
 355         packet_set_socket(kdcconn->packet, conn->socket);
 356         packet_set_callback(kdcconn->packet, kdc_tcp_recv);
 357         packet_set_full_request(kdcconn->packet, packet_full_request_u32);
 358         packet_set_error_handler(kdcconn->packet, kdc_tcp_recv_error);
 359         packet_set_event_context(kdcconn->packet, conn->event.ctx);
 360         packet_set_fde(kdcconn->packet, conn->event.fde);
 361         packet_set_serialise(kdcconn->packet);
 362 }
 363
 364 static void kdc_tcp_accept(struct stream_connection *conn)
 365 {
 366         kdc_tcp_generic_accept(conn, kdc_process);
 367 }
 368
 369 static const struct stream_server_ops kdc_tcp_stream_ops = {
 370         .name                   = "kdc_tcp",
 371         .accept_connection      = kdc_tcp_accept,
 372         .recv_handler           = kdc_tcp_recv_handler,
 373         .send_handler           = kdc_tcp_send
 374 };
 375
 376 static void kpasswdd_tcp_accept(struct stream_connection *conn)
 377 {
 378         kdc_tcp_generic_accept(conn, kpasswdd_process);
 379 }
 380
 381 static const struct stream_server_ops kpasswdd_tcp_stream_ops = {
 382         .name                   = "kpasswdd_tcp",
 383         .accept_connection      = kpasswdd_tcp_accept,
 384         .recv_handler           = kdc_tcp_recv_handler,
 385         .send_handler           = kdc_tcp_send
 386 };
 387
 388 /*
 389   start listening on the given address
 390 */
 391 static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
 392 {
 393         const struct model_ops *model_ops;
 394         struct kdc_socket *kdc_socket;
 395         struct kdc_socket *kpasswd_socket;
 396         NTSTATUS status;
 397         uint16_t kdc_port = lp_krb5_port();
 398         uint16_t kpasswd_port = lp_kpasswd_port();
 399
 400         kdc_socket = talloc(kdc, struct kdc_socket);
 401         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 402
 403         kpasswd_socket = talloc(kdc, struct kdc_socket);
 404         NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket);
 405
 406         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
 407         if (!NT_STATUS_IS_OK(status)) {
 408                 talloc_free(kdc_socket);
 409                 return status;
 410         }
 411
 412         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0);
 413         if (!NT_STATUS_IS_OK(status)) {
 414                 talloc_free(kpasswd_socket);
 415                 return status;
 416         }
 417
 418         kdc_socket->kdc = kdc;
 419         kdc_socket->send_queue = NULL;
 420         kdc_socket->process = kdc_process;
 421
 422         talloc_steal(kdc_socket, kdc_socket->sock);
 423
 424         kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 425                                        socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
 426                                        kdc_socket_handler, kdc_socket);
 427
 428         status = socket_listen(kdc_socket->sock, address, kdc_port, 0, 0);
 429         if (!NT_STATUS_IS_OK(status)) {
 430                 DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n",
 431                          address, kdc_port, nt_errstr(status)));
 432                 talloc_free(kdc_socket);
 433                 return status;
 434         }
 435
 436         kpasswd_socket->kdc = kdc;
 437         kpasswd_socket->send_queue = NULL;
 438         kpasswd_socket->process = kpasswdd_process;
 439
 440         talloc_steal(kpasswd_socket, kpasswd_socket->sock);
 441
 442         kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 443                                            socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ,
 444                                            kdc_socket_handler, kpasswd_socket);
 445
 446         status = socket_listen(kpasswd_socket->sock, address, kpasswd_port, 0, 0);
 447         if (!NT_STATUS_IS_OK(status)) {
 448                 DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n",
 449                          address, kpasswd_port, nt_errstr(status)));
 450                 talloc_free(kpasswd_socket);
 451                 return status;
 452         }
 453
 454         /* within the kdc task we want to be a single process, so
 455            ask for the single process model ops and pass these to the
 456            stream_setup_socket() call. */
 457         model_ops = process_model_byname("single");
 458         if (!model_ops) {
 459                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 460                 talloc_free(kdc_socket);
 461                 return NT_STATUS_INTERNAL_ERROR;
 462         }
 463
 464         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 465                                      &kdc_tcp_stream_ops,
 466                                      "ip", address, &kdc_port, kdc);
 467         if (!NT_STATUS_IS_OK(status)) {
 468                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 469                          address, kdc_port, nt_errstr(status)));
 470                 talloc_free(kdc_socket);
 471                 return status;
 472         }
 473
 474         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 475                                      &kpasswdd_tcp_stream_ops,
 476                                      "ip", address, &kpasswd_port, kdc);
 477         if (!NT_STATUS_IS_OK(status)) {
 478                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 479                          address, kpasswd_port, nt_errstr(status)));
 480                 talloc_free(kdc_socket);
 481                 return status;
 482         }
 483
 484         return NT_STATUS_OK;
 485 }
 486
 487
 488 /*
 489   setup our listening sockets on the configured network interfaces
 490 */
 491 static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
 492 {
 493         int num_interfaces = iface_count();
 494         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 495         NTSTATUS status;
 496
 497         /* if we are allowing incoming packets from any address, then
 498            we need to bind to the wildcard address */
 499         if (!lp_bind_interfaces_only()) {
 500                 status = kdc_add_socket(kdc, "0.0.0.0");
 501                 NT_STATUS_NOT_OK_RETURN(status);
 502         } else {
 503                 int i;
 504
 505                 for (i=0; i<num_interfaces; i++) {
 506                         const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
 507                         status = kdc_add_socket(kdc, address);
 508                         NT_STATUS_NOT_OK_RETURN(status);
 509                 }
 510         }
 511
 512         talloc_free(tmp_ctx);
 513
 514         return NT_STATUS_OK;
 515 }
 516
 517 /*
 518   startup the kdc task
 519 */
 520 static void kdc_task_init(struct task_server *task)
 521 {
 522         struct kdc_server *kdc;
 523         NTSTATUS status;
 524         krb5_error_code ret;
 525
 526         if (iface_count() == 0) {
 527                 task_server_terminate(task, "kdc: no network interfaces configured");
 528                 return;
 529         }
 530
 531         kdc = talloc(task, struct kdc_server);
 532         if (kdc == NULL) {
 533                 task_server_terminate(task, "kdc: out of memory");
 534                 return;
 535         }
 536
 537         kdc->task = task;
 538
 539         /* Setup the KDC configuration */
 540         kdc->config = talloc(kdc, krb5_kdc_configuration);
 541         if (!kdc->config) {
 542                 task_server_terminate(task, "kdc: out of memory");
 543                 return;
 544         }
 545         krb5_kdc_default_config(kdc->config);
 546
 547         initialize_krb5_error_table();
 548
 549         ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
 550         if (ret) {
 551                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 552                          error_message(ret)));
 553                 task_server_terminate(task, "kdc: krb5_init_context failed");
 554                 return;
 555         }
 556
 557         krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
 558
 559         kdc->config->logf = kdc->smb_krb5_context->logf;
 560         kdc->config->db = talloc(kdc->config, struct HDB *);
 561         if (!kdc->config->db) {
 562                 task_server_terminate(task, "kdc: out of memory");
 563                 return;
 564         }
 565         kdc->config->num_db = 1;
 566
 567         ret = hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context,
 568                              &kdc->config->db[0], NULL);
 569         if (ret != 0) {
 570                 DEBUG(1, ("kdc_task_init: hdb_ldb_create fails: %s\n",
 571                           smb_get_krb5_error_message(kdc->smb_krb5_context->krb5_context, ret, kdc)));
 572                 task_server_terminate(task, "kdc: hdb_ldb_create failed");
 573                 return;
 574         }
 575
 576         /* start listening on the configured network interfaces */
 577         status = kdc_startup_interfaces(kdc);
 578         if (!NT_STATUS_IS_OK(status)) {
 579                 task_server_terminate(task, "kdc failed to setup interfaces");
 580                 return;
 581         }
 582
 583         irpc_add_name(task->msg_ctx, "kdc_server");
 584 }
 585
 586
 587 /*
 588   called on startup of the KDC service
 589 */
 590 static NTSTATUS kdc_init(struct event_context *event_ctx,
 591                          const struct model_ops *model_ops)
 592 {
 593         return task_server_startup(event_ctx, model_ops, kdc_task_init);
 594 }
 595
 596 /* called at smbd startup - register ourselves as a server service */
 597 NTSTATUS server_service_kdc_init(void)
 598 {
 599         return register_server_service("kdc", kdc_init);
 600 }