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 "smbd/process_model.h"
  29 #include "lib/events/events.h"
  30 #include "lib/socket/socket.h"
  31 #include "kdc/kdc.h"
  32 #include "system/network.h"
  33 #include "dlinklist.h"
  34 #include "lib/messaging/irpc.h"
  35 #include "lib/stream/packet.h"
  36 #include "librpc/gen_ndr/samr.h"
  37 #include "netif/netif.h"
  38
  39 /* hold all the info needed to send a reply */
  40 struct kdc_reply {
  41         struct kdc_reply *next, *prev;
  42         struct socket_address *dest;
  43         DATA_BLOB packet;
  44 };
  45
  46 typedef BOOL (*kdc_process_fn_t)(struct kdc_server *kdc,
  47                                  TALLOC_CTX *mem_ctx,
  48                                  DATA_BLOB *input,
  49                                  DATA_BLOB *reply,
  50                                  struct socket_address *peer_addr,
  51                                  struct socket_address *my_addr);
  52
  53 /* hold information about one kdc socket */
  54 struct kdc_socket {
  55         struct socket_context *sock;
  56         struct kdc_server *kdc;
  57         struct fd_event *fde;
  58
  59         /* a queue of outgoing replies that have been deferred */
  60         struct kdc_reply *send_queue;
  61
  62         kdc_process_fn_t process;
  63 };
  64 /*
  65   state of an open tcp connection
  66 */
  67 struct kdc_tcp_connection {
  68         /* stream connection we belong to */
  69         struct stream_connection *conn;
  70
  71         /* the kdc_server the connection belongs to */
  72         struct kdc_server *kdc;
  73
  74         struct packet_context *packet;
  75
  76         kdc_process_fn_t process;
  77 };
  78
  79 /*
  80   handle fd send events on a KDC socket
  81 */
  82 static void kdc_send_handler(struct kdc_socket *kdc_socket)
  83 {
  84         while (kdc_socket->send_queue) {
  85                 struct kdc_reply *rep = kdc_socket->send_queue;
  86                 NTSTATUS status;
  87                 size_t sendlen;
  88
  89                 status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, 0,
  90                                        rep->dest);
  91                 if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
  92                         break;
  93                 }
  94                 if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_BUFFER_SIZE)) {
  95                         /* Replace with a krb err, response to big */
  96                 }
  97
  98                 DLIST_REMOVE(kdc_socket->send_queue, rep);
  99                 talloc_free(rep);
 100         }
 101
 102         if (kdc_socket->send_queue == NULL) {
 103                 EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
 104         }
 105 }
 106
 107
 108 /*
 109   handle fd recv events on a KDC socket
 110 */
 111 static void kdc_recv_handler(struct kdc_socket *kdc_socket)
 112 {
 113         NTSTATUS status;
 114         TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
 115         DATA_BLOB blob;
 116         struct kdc_reply *rep;
 117         DATA_BLOB reply;
 118         size_t nread, dsize;
 119         struct socket_address *src;
 120         struct socket_address *my_addr;
 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                                  tmp_ctx, &src);
 138         if (!NT_STATUS_IS_OK(status)) {
 139                 talloc_free(tmp_ctx);
 140                 return;
 141         }
 142         blob.length = nread;
 143
 144         DEBUG(10,("Received krb5 UDP packet of length %lu from %s:%u\n",
 145                  (long)blob.length, src->addr, (uint16_t)src->port));
 146
 147         my_addr = socket_get_my_addr(kdc_socket->sock, tmp_ctx);
 148         if (!my_addr) {
 149                 talloc_free(tmp_ctx);
 150                 return;
 151         }
 152
 153
 154         /* Call krb5 */
 155         ret = kdc_socket->process(kdc_socket->kdc,
 156                                   tmp_ctx,
 157                                   &blob,
 158                                   &reply,
 159                                   src, my_addr);
 160         if (!ret) {
 161                 talloc_free(tmp_ctx);
 162                 return;
 163         }
 164
 165         /* queue a pending reply */
 166         rep = talloc(kdc_socket, struct kdc_reply);
 167         if (rep == NULL) {
 168                 talloc_free(tmp_ctx);
 169                 return;
 170         }
 171         rep->dest         = talloc_steal(rep, src);
 172         rep->packet       = reply;
 173         talloc_steal(rep, reply.data);
 174
 175         if (rep->packet.data == NULL) {
 176                 talloc_free(rep);
 177                 talloc_free(tmp_ctx);
 178                 return;
 179         }
 180
 181         DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
 182         EVENT_FD_WRITEABLE(kdc_socket->fde);
 183         talloc_free(tmp_ctx);
 184 }
 185
 186 /*
 187   handle fd events on a KDC socket
 188 */
 189 static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
 190                                uint16_t flags, void *private)
 191 {
 192         struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
 193         if (flags & EVENT_FD_WRITE) {
 194                 kdc_send_handler(kdc_socket);
 195         }
 196         if (flags & EVENT_FD_READ) {
 197                 kdc_recv_handler(kdc_socket);
 198         }
 199 }
 200
 201 static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
 202 {
 203         stream_terminate_connection(kdcconn->conn, reason);
 204 }
 205
 206 /*
 207   receive a full packet on a KDC connection
 208 */
 209 static NTSTATUS kdc_tcp_recv(void *private, DATA_BLOB blob)
 210 {
 211         struct kdc_tcp_connection *kdcconn = talloc_get_type(private,
 212                                                              struct kdc_tcp_connection);
 213         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
 214         TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
 215         int ret;
 216         DATA_BLOB input, reply;
 217         struct socket_address *src_addr;
 218         struct socket_address *my_addr;
 219
 220         talloc_steal(tmp_ctx, blob.data);
 221
 222         src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
 223         if (!src_addr) {
 224                 talloc_free(tmp_ctx);
 225                 return NT_STATUS_NO_MEMORY;
 226         }
 227
 228         my_addr = socket_get_my_addr(kdcconn->conn->socket, tmp_ctx);
 229         if (!my_addr) {
 230                 talloc_free(tmp_ctx);
 231                 return NT_STATUS_NO_MEMORY;
 232         }
 233
 234         /* Call krb5 */
 235         input = data_blob_const(blob.data + 4, blob.length - 4);
 236
 237         ret = kdcconn->process(kdcconn->kdc,
 238                                tmp_ctx,
 239                                &input,
 240                                &reply,
 241                                src_addr,
 242                                my_addr);
 243         if (!ret) {
 244                 talloc_free(tmp_ctx);
 245                 return NT_STATUS_INTERNAL_ERROR;
 246         }
 247
 248         /* and now encode the reply */
 249         blob = data_blob_talloc(kdcconn, NULL, reply.length + 4);
 250         if (!blob.data) {
 251                 talloc_free(tmp_ctx);
 252                 return NT_STATUS_NO_MEMORY;
 253         }
 254
 255         RSIVAL(blob.data, 0, reply.length);
 256         memcpy(blob.data + 4, reply.data, reply.length);
 257
 258         status = packet_send(kdcconn->packet, blob);
 259         if (!NT_STATUS_IS_OK(status)) {
 260                 talloc_free(tmp_ctx);
 261                 return status;
 262         }
 263
 264         /* the call isn't needed any more */
 265         talloc_free(tmp_ctx);
 266         return NT_STATUS_OK;
 267 }
 268
 269 /*
 270   receive some data on a KDC connection
 271 */
 272 static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags)
 273 {
 274         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 275                                                              struct kdc_tcp_connection);
 276         packet_recv(kdcconn->packet);
 277 }
 278
 279 /*
 280   called on a tcp recv error
 281 */
 282 static void kdc_tcp_recv_error(void *private, NTSTATUS status)
 283 {
 284         struct kdc_tcp_connection *kdcconn = talloc_get_type(private, struct kdc_tcp_connection);
 285         kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
 286 }
 287
 288 /*
 289   called when we can write to a connection
 290 */
 291 static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
 292 {
 293         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private,
 294                                                              struct kdc_tcp_connection);
 295         packet_queue_run(kdcconn->packet);
 296 }
 297
 298 /**
 299    Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
 300    calling conventions
 301 */
 302
 303 static BOOL kdc_process(struct kdc_server *kdc,
 304                         TALLOC_CTX *mem_ctx,
 305                         DATA_BLOB *input,
 306                         DATA_BLOB *reply,
 307                         struct socket_address *peer_addr,
 308                         struct socket_address *my_addr)
 309 {
 310         int ret;
 311         krb5_data k5_reply;
 312
 313         DEBUG(10,("Received KDC packet of length %lu from %s:%d\n",
 314                   (long)input->length - 4, peer_addr->addr, peer_addr->port));
 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                                             peer_addr->addr,
 321                                             peer_addr->sockaddr);
 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         struct socket_address *kdc_address, *kpasswd_address;
 397         NTSTATUS status;
 398         uint16_t kdc_port = lp_krb5_port();
 399         uint16_t kpasswd_port = lp_kpasswd_port();
 400
 401         kdc_socket = talloc(kdc, struct kdc_socket);
 402         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 403
 404         kpasswd_socket = talloc(kdc, struct kdc_socket);
 405         NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket);
 406
 407         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
 408         if (!NT_STATUS_IS_OK(status)) {
 409                 talloc_free(kdc_socket);
 410                 return status;
 411         }
 412
 413         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0);
 414         if (!NT_STATUS_IS_OK(status)) {
 415                 talloc_free(kpasswd_socket);
 416                 return status;
 417         }
 418
 419         kdc_socket->kdc = kdc;
 420         kdc_socket->send_queue = NULL;
 421         kdc_socket->process = kdc_process;
 422
 423         talloc_steal(kdc_socket, kdc_socket->sock);
 424
 425         kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 426                                        socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
 427                                        kdc_socket_handler, kdc_socket);
 428
 429         kdc_address = socket_address_from_strings(kdc_socket, kdc_socket->sock->backend_name,
 430                                                   address, kdc_port);
 431         NT_STATUS_HAVE_NO_MEMORY(kdc_address);
 432
 433         status = socket_listen(kdc_socket->sock, kdc_address, 0, 0);
 434         if (!NT_STATUS_IS_OK(status)) {
 435                 DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n",
 436                          address, kdc_port, nt_errstr(status)));
 437                 talloc_free(kdc_socket);
 438                 return status;
 439         }
 440
 441         kpasswd_socket->kdc = kdc;
 442         kpasswd_socket->send_queue = NULL;
 443         kpasswd_socket->process = kpasswdd_process;
 444
 445         talloc_steal(kpasswd_socket, kpasswd_socket->sock);
 446
 447         kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 448                                            socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ,
 449                                            kdc_socket_handler, kpasswd_socket);
 450
 451         kpasswd_address = socket_address_from_strings(kpasswd_socket, kpasswd_socket->sock->backend_name,
 452                                                       address, kpasswd_port);
 453         NT_STATUS_HAVE_NO_MEMORY(kpasswd_address);
 454
 455         status = socket_listen(kpasswd_socket->sock, kpasswd_address, 0, 0);
 456         if (!NT_STATUS_IS_OK(status)) {
 457                 DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n",
 458                          address, kpasswd_port, nt_errstr(status)));
 459                 talloc_free(kpasswd_socket);
 460                 return status;
 461         }
 462
 463         /* within the kdc task we want to be a single process, so
 464            ask for the single process model ops and pass these to the
 465            stream_setup_socket() call. */
 466         model_ops = process_model_byname("single");
 467         if (!model_ops) {
 468                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 469                 talloc_free(kdc_socket);
 470                 return NT_STATUS_INTERNAL_ERROR;
 471         }
 472
 473         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 474                                      &kdc_tcp_stream_ops,
 475                                      "ip", address, &kdc_port, kdc);
 476         if (!NT_STATUS_IS_OK(status)) {
 477                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 478                          address, kdc_port, nt_errstr(status)));
 479                 talloc_free(kdc_socket);
 480                 return status;
 481         }
 482
 483         status = stream_setup_socket(kdc->task->event_ctx, model_ops,
 484                                      &kpasswdd_tcp_stream_ops,
 485                                      "ip", address, &kpasswd_port, kdc);
 486         if (!NT_STATUS_IS_OK(status)) {
 487                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 488                          address, kpasswd_port, nt_errstr(status)));
 489                 talloc_free(kdc_socket);
 490                 return status;
 491         }
 492
 493         return NT_STATUS_OK;
 494 }
 495
 496
 497 /*
 498   setup our listening sockets on the configured network interfaces
 499 */
 500 static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
 501 {
 502         int num_interfaces = iface_count();
 503         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 504         NTSTATUS status;
 505
 506         int i;
 507
 508         for (i=0; i<num_interfaces; i++) {
 509                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
 510                 status = kdc_add_socket(kdc, address);
 511                 NT_STATUS_NOT_OK_RETURN(status);
 512         }
 513
 514         talloc_free(tmp_ctx);
 515
 516         return NT_STATUS_OK;
 517 }
 518
 519 /*
 520   startup the kdc task
 521 */
 522 static void kdc_task_init(struct task_server *task)
 523 {
 524         struct kdc_server *kdc;
 525         NTSTATUS status;
 526         krb5_error_code ret;
 527
 528         switch (lp_server_role()) {
 529         case ROLE_STANDALONE:
 530                 task_server_terminate(task, "kdc: no KDC required in standalone configuration");
 531                 return;
 532         case ROLE_DOMAIN_MEMBER:
 533                 task_server_terminate(task, "kdc: no KDC required in member server configuration");
 534                 return;
 535         case ROLE_DOMAIN_PDC:
 536         case ROLE_DOMAIN_BDC:
 537                 /* Yes, we want a KDC */
 538                 break;
 539         }
 540
 541         if (iface_count() == 0) {
 542                 task_server_terminate(task, "kdc: no network interfaces configured");
 543                 return;
 544         }
 545
 546         kdc = talloc(task, struct kdc_server);
 547         if (kdc == NULL) {
 548                 task_server_terminate(task, "kdc: out of memory");
 549                 return;
 550         }
 551
 552         kdc->task = task;
 553
 554         /* Setup the KDC configuration */
 555         kdc->config = talloc(kdc, krb5_kdc_configuration);
 556         if (!kdc->config) {
 557                 task_server_terminate(task, "kdc: out of memory");
 558                 return;
 559         }
 560         krb5_kdc_default_config(kdc->config);
 561
 562         initialize_krb5_error_table();
 563
 564         ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
 565         if (ret) {
 566                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 567                          error_message(ret)));
 568                 task_server_terminate(task, "kdc: krb5_init_context failed");
 569                 return;
 570         }
 571
 572         krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
 573
 574         kdc->config->logf = kdc->smb_krb5_context->logf;
 575         kdc->config->db = talloc(kdc->config, struct HDB *);
 576         if (!kdc->config->db) {
 577                 task_server_terminate(task, "kdc: out of memory");
 578                 return;
 579         }
 580         kdc->config->num_db = 1;
 581
 582         status = kdc_hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context,
 583                                     &kdc->config->db[0], NULL);
 584         if (!NT_STATUS_IS_OK(status)) {
 585                 task_server_terminate(task, "kdc: hdb_ldb_create (setup KDC database) failed");
 586                 return;
 587         }
 588
 589         ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
 590         if(ret) {
 591                 task_server_terminate(task, "kdc: failed to register hdb keytab");
 592                 return;
 593         }
 594         /* start listening on the configured network interfaces */
 595         status = kdc_startup_interfaces(kdc);
 596         if (!NT_STATUS_IS_OK(status)) {
 597                 task_server_terminate(task, "kdc failed to setup interfaces");
 598                 return;
 599         }
 600
 601         irpc_add_name(task->msg_ctx, "kdc_server");
 602 }
 603
 604
 605 /*
 606   called on startup of the KDC service
 607 */
 608 static NTSTATUS kdc_init(struct event_context *event_ctx,
 609                          const struct model_ops *model_ops)
 610 {
 611         return task_server_startup(event_ctx, model_ops, kdc_task_init);
 612 }
 613
 614 /* called at smbd startup - register ourselves as a server service */
 615 NTSTATUS server_service_kdc_init(void)
 616 {
 617         return register_server_service("kdc", kdc_init);
 618 }