source4/kdc/kdc-server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    KDC related functions
   5
   6    Copyright (c) 2005-2008 Andrew Bartlett <abartlet@samba.org>
   7    Copyright (c) 2005      Andrew Tridgell <tridge@samba.org>
   8    Copyright (c) 2005      Stefan Metzmacher <metze@samba.org>
   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 3 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, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "param/param.h"
  26 #include "smbd/process_model.h"
  27 #include "lib/tsocket/tsocket.h"
  28 #include "libcli/util/tstream.h"
  29 #include "kdc/kdc-server.h"
  30 #include "kdc/kdc-proxy.h"
  31 #include "lib/stream/packet.h"
  32
  33 /*
  34  * State of an open tcp connection
  35  */
  36 struct kdc_tcp_connection {
  37         /* stream connection we belong to */
  38         struct stream_connection *conn;
  39
  40         /* the kdc_server the connection belongs to */
  41         struct kdc_socket *kdc_socket;
  42
  43         struct tstream_context *tstream;
  44
  45         struct tevent_queue *send_queue;
  46 };
  47
  48 struct kdc_tcp_call {
  49         struct kdc_tcp_connection *kdc_conn;
  50         DATA_BLOB in;
  51         DATA_BLOB out;
  52         uint8_t out_hdr[4];
  53         struct iovec out_iov[2];
  54 };
  55
  56 struct kdc_udp_call {
  57         struct kdc_udp_socket *sock;
  58         struct tsocket_address *src;
  59         DATA_BLOB in;
  60         DATA_BLOB out;
  61 };
  62
  63 static void kdc_udp_call_proxy_done(struct tevent_req *subreq);
  64 static void kdc_udp_call_sendto_done(struct tevent_req *subreq);
  65
  66 static void kdc_tcp_call_writev_done(struct tevent_req *subreq);
  67 static void kdc_tcp_call_proxy_done(struct tevent_req *subreq);
  68
  69 static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdc_conn,
  70                                          const char *reason)
  71 {
  72         stream_terminate_connection(kdc_conn->conn, reason);
  73 }
  74
  75 static NTSTATUS kdc_proxy_unavailable_error(struct kdc_server *kdc,
  76                                             TALLOC_CTX *mem_ctx,
  77                                             DATA_BLOB *out)
  78 {
  79         krb5_error_code code;
  80         krb5_data enc_error;
  81
  82         code = smb_krb5_mk_error(kdc->smb_krb5_context->krb5_context,
  83                                  KRB5KDC_ERR_SVC_UNAVAILABLE,
  84                                  NULL,
  85                                  NULL,
  86                                  NULL,
  87                                  NULL,
  88                                  &enc_error);
  89         if (code != 0) {
  90                 DBG_WARNING("Unable to form krb5 error reply\n");
  91                 return NT_STATUS_INTERNAL_ERROR;
  92         }
  93
  94         *out = data_blob_talloc(mem_ctx, enc_error.data, enc_error.length);
  95         smb_krb5_free_data_contents(kdc->smb_krb5_context->krb5_context,
  96                                     &enc_error);
  97         if (!out->data) {
  98                 return NT_STATUS_NO_MEMORY;
  99         }
 100
 101         return NT_STATUS_OK;
 102 }
 103
 104 static void kdc_udp_call_loop(struct tevent_req *subreq)
 105 {
 106         struct kdc_udp_socket *sock = tevent_req_callback_data(subreq,
 107                                       struct kdc_udp_socket);
 108         struct kdc_udp_call *call;
 109         uint8_t *buf;
 110         ssize_t len;
 111         int sys_errno;
 112         kdc_code ret;
 113
 114         call = talloc(sock, struct kdc_udp_call);
 115         if (call == NULL) {
 116                 talloc_free(call);
 117                 goto done;
 118         }
 119         call->sock = sock;
 120
 121         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 122                                    call, &buf, &call->src);
 123         TALLOC_FREE(subreq);
 124         if (len == -1) {
 125                 talloc_free(call);
 126                 goto done;
 127         }
 128
 129         call->in.data = buf;
 130         call->in.length = len;
 131
 132         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 133                  (long)call->in.length,
 134                  tsocket_address_string(call->src, call)));
 135
 136         /* Call krb5 */
 137         ret = sock->kdc_socket->process(sock->kdc_socket->kdc,
 138                                        call,
 139                                        &call->in,
 140                                        &call->out,
 141                                        call->src,
 142                                        sock->kdc_socket->local_address,
 143                                        1 /* Datagram */);
 144         if (ret == KDC_ERROR) {
 145                 talloc_free(call);
 146                 goto done;
 147         }
 148
 149         if (ret == KDC_PROXY_REQUEST) {
 150                 uint16_t port;
 151
 152                 if (!sock->kdc_socket->kdc->am_rodc) {
 153                         DEBUG(0,("kdc_udp_call_loop: proxying requested when not RODC"));
 154                         talloc_free(call);
 155                         goto done;
 156                 }
 157
 158                 port = tsocket_address_inet_port(sock->kdc_socket->local_address);
 159
 160                 subreq = kdc_udp_proxy_send(call,
 161                                             sock->kdc_socket->kdc->task->event_ctx,
 162                                             sock->kdc_socket->kdc,
 163                                             port,
 164                                             call->in);
 165                 if (subreq == NULL) {
 166                         talloc_free(call);
 167                         goto done;
 168                 }
 169                 tevent_req_set_callback(subreq, kdc_udp_call_proxy_done, call);
 170                 goto done;
 171         }
 172
 173         subreq = tdgram_sendto_queue_send(call,
 174                                           sock->kdc_socket->kdc->task->event_ctx,
 175                                           sock->dgram,
 176                                           sock->send_queue,
 177                                           call->out.data,
 178                                           call->out.length,
 179                                           call->src);
 180         if (subreq == NULL) {
 181                 talloc_free(call);
 182                 goto done;
 183         }
 184         tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
 185
 186 done:
 187         subreq = tdgram_recvfrom_send(sock,
 188                                       sock->kdc_socket->kdc->task->event_ctx,
 189                                       sock->dgram);
 190         if (subreq == NULL) {
 191                 task_server_terminate(sock->kdc_socket->kdc->task,
 192                                       "no memory for tdgram_recvfrom_send",
 193                                       true);
 194                 return;
 195         }
 196         tevent_req_set_callback(subreq, kdc_udp_call_loop, sock);
 197 }
 198
 199 static void kdc_udp_call_proxy_done(struct tevent_req *subreq)
 200 {
 201         struct kdc_udp_call *call =
 202                 tevent_req_callback_data(subreq,
 203                 struct kdc_udp_call);
 204         NTSTATUS status;
 205
 206         status = kdc_udp_proxy_recv(subreq, call, &call->out);
 207         TALLOC_FREE(subreq);
 208         if (!NT_STATUS_IS_OK(status)) {
 209                 /* generate an error packet */
 210                 status = kdc_proxy_unavailable_error(call->sock->kdc_socket->kdc,
 211                                                      call, &call->out);
 212         }
 213
 214         if (!NT_STATUS_IS_OK(status)) {
 215                 talloc_free(call);
 216                 return;
 217         }
 218
 219         subreq = tdgram_sendto_queue_send(call,
 220                                           call->sock->kdc_socket->kdc->task->event_ctx,
 221                                           call->sock->dgram,
 222                                           call->sock->send_queue,
 223                                           call->out.data,
 224                                           call->out.length,
 225                                           call->src);
 226         if (subreq == NULL) {
 227                 talloc_free(call);
 228                 return;
 229         }
 230
 231         tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
 232 }
 233
 234 static void kdc_udp_call_sendto_done(struct tevent_req *subreq)
 235 {
 236         struct kdc_udp_call *call = tevent_req_callback_data(subreq,
 237                                        struct kdc_udp_call);
 238         int sys_errno;
 239
 240         tdgram_sendto_queue_recv(subreq, &sys_errno);
 241
 242         /* We don't care about errors */
 243
 244         talloc_free(call);
 245 }
 246
 247 static void kdc_tcp_call_loop(struct tevent_req *subreq)
 248 {
 249         struct kdc_tcp_connection *kdc_conn = tevent_req_callback_data(subreq,
 250                                       struct kdc_tcp_connection);
 251         struct kdc_tcp_call *call;
 252         NTSTATUS status;
 253         kdc_code ret;
 254
 255         call = talloc(kdc_conn, struct kdc_tcp_call);
 256         if (call == NULL) {
 257                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 258                                 "no memory for kdc_tcp_call");
 259                 return;
 260         }
 261         call->kdc_conn = kdc_conn;
 262
 263         status = tstream_read_pdu_blob_recv(subreq,
 264                                             call,
 265                                             &call->in);
 266         TALLOC_FREE(subreq);
 267         if (!NT_STATUS_IS_OK(status)) {
 268                 const char *reason;
 269
 270                 reason = talloc_asprintf(call, "kdc_tcp_call_loop: "
 271                                          "tstream_read_pdu_blob_recv() - %s",
 272                                          nt_errstr(status));
 273                 if (!reason) {
 274                         reason = nt_errstr(status);
 275                 }
 276
 277                 kdc_tcp_terminate_connection(kdc_conn, reason);
 278                 return;
 279         }
 280
 281         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 282                  (long) call->in.length,
 283                  tsocket_address_string(kdc_conn->conn->remote_address, call)));
 284
 285         /* skip length header */
 286         call->in.data +=4;
 287         call->in.length -= 4;
 288
 289         /* Call krb5 */
 290         ret = kdc_conn->kdc_socket->process(kdc_conn->kdc_socket->kdc,
 291                                            call,
 292                                            &call->in,
 293                                            &call->out,
 294                                            kdc_conn->conn->remote_address,
 295                                            kdc_conn->conn->local_address,
 296                                            0 /* Stream */);
 297         if (ret == KDC_ERROR) {
 298                 kdc_tcp_terminate_connection(kdc_conn,
 299                                 "kdc_tcp_call_loop: process function failed");
 300                 return;
 301         }
 302
 303         if (ret == KDC_PROXY_REQUEST) {
 304                 uint16_t port;
 305
 306                 if (!kdc_conn->kdc_socket->kdc->am_rodc) {
 307                         kdc_tcp_terminate_connection(kdc_conn,
 308                                                      "kdc_tcp_call_loop: proxying requested when not RODC");
 309                         return;
 310                 }
 311                 port = tsocket_address_inet_port(kdc_conn->conn->local_address);
 312
 313                 subreq = kdc_tcp_proxy_send(call,
 314                                             kdc_conn->conn->event.ctx,
 315                                             kdc_conn->kdc_socket->kdc,
 316                                             port,
 317                                             call->in);
 318                 if (subreq == NULL) {
 319                         kdc_tcp_terminate_connection(kdc_conn,
 320                                 "kdc_tcp_call_loop: kdc_tcp_proxy_send failed");
 321                         return;
 322                 }
 323                 tevent_req_set_callback(subreq, kdc_tcp_call_proxy_done, call);
 324                 return;
 325         }
 326
 327         /* First add the length of the out buffer */
 328         RSIVAL(call->out_hdr, 0, call->out.length);
 329         call->out_iov[0].iov_base = (char *) call->out_hdr;
 330         call->out_iov[0].iov_len = 4;
 331
 332         call->out_iov[1].iov_base = (char *) call->out.data;
 333         call->out_iov[1].iov_len = call->out.length;
 334
 335         subreq = tstream_writev_queue_send(call,
 336                                            kdc_conn->conn->event.ctx,
 337                                            kdc_conn->tstream,
 338                                            kdc_conn->send_queue,
 339                                            call->out_iov, 2);
 340         if (subreq == NULL) {
 341                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 342                                 "no memory for tstream_writev_queue_send");
 343                 return;
 344         }
 345         tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
 346
 347         /*
 348          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 349          * packet_full_request_u32 provides the pdu length then.
 350          */
 351         subreq = tstream_read_pdu_blob_send(kdc_conn,
 352                                             kdc_conn->conn->event.ctx,
 353                                             kdc_conn->tstream,
 354                                             4, /* initial_read_size */
 355                                             packet_full_request_u32,
 356                                             kdc_conn);
 357         if (subreq == NULL) {
 358                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 359                                 "no memory for tstream_read_pdu_blob_send");
 360                 return;
 361         }
 362         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 363 }
 364
 365 static void kdc_tcp_call_proxy_done(struct tevent_req *subreq)
 366 {
 367         struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
 368                         struct kdc_tcp_call);
 369         struct kdc_tcp_connection *kdc_conn = call->kdc_conn;
 370         NTSTATUS status;
 371
 372         status = kdc_tcp_proxy_recv(subreq, call, &call->out);
 373         TALLOC_FREE(subreq);
 374         if (!NT_STATUS_IS_OK(status)) {
 375                 /* generate an error packet */
 376                 status = kdc_proxy_unavailable_error(kdc_conn->kdc_socket->kdc,
 377                                                      call, &call->out);
 378         }
 379
 380         if (!NT_STATUS_IS_OK(status)) {
 381                 const char *reason;
 382
 383                 reason = talloc_asprintf(call, "kdc_tcp_call_proxy_done: "
 384                                          "kdc_proxy_unavailable_error - %s",
 385                                          nt_errstr(status));
 386                 if (!reason) {
 387                         reason = "kdc_tcp_call_proxy_done: kdc_proxy_unavailable_error() failed";
 388                 }
 389
 390                 kdc_tcp_terminate_connection(call->kdc_conn, reason);
 391                 return;
 392         }
 393
 394         /* First add the length of the out buffer */
 395         RSIVAL(call->out_hdr, 0, call->out.length);
 396         call->out_iov[0].iov_base = (char *) call->out_hdr;
 397         call->out_iov[0].iov_len = 4;
 398
 399         call->out_iov[1].iov_base = (char *) call->out.data;
 400         call->out_iov[1].iov_len = call->out.length;
 401
 402         subreq = tstream_writev_queue_send(call,
 403                                            kdc_conn->conn->event.ctx,
 404                                            kdc_conn->tstream,
 405                                            kdc_conn->send_queue,
 406                                            call->out_iov, 2);
 407         if (subreq == NULL) {
 408                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 409                                 "no memory for tstream_writev_queue_send");
 410                 return;
 411         }
 412         tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
 413
 414         /*
 415          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 416          * packet_full_request_u32 provides the pdu length then.
 417          */
 418         subreq = tstream_read_pdu_blob_send(kdc_conn,
 419                                             kdc_conn->conn->event.ctx,
 420                                             kdc_conn->tstream,
 421                                             4, /* initial_read_size */
 422                                             packet_full_request_u32,
 423                                             kdc_conn);
 424         if (subreq == NULL) {
 425                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 426                                 "no memory for tstream_read_pdu_blob_send");
 427                 return;
 428         }
 429         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 430 }
 431
 432 static void kdc_tcp_call_writev_done(struct tevent_req *subreq)
 433 {
 434         struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
 435                         struct kdc_tcp_call);
 436         int sys_errno;
 437         int rc;
 438
 439         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 440         TALLOC_FREE(subreq);
 441         if (rc == -1) {
 442                 const char *reason;
 443
 444                 reason = talloc_asprintf(call, "kdc_tcp_call_writev_done: "
 445                                          "tstream_writev_queue_recv() - %d:%s",
 446                                          sys_errno, strerror(sys_errno));
 447                 if (!reason) {
 448                         reason = "kdc_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 449                 }
 450
 451                 kdc_tcp_terminate_connection(call->kdc_conn, reason);
 452                 return;
 453         }
 454
 455         /* We don't care about errors */
 456
 457         talloc_free(call);
 458 }
 459
 460 /*
 461   called when we get a new connection
 462 */
 463 static void kdc_tcp_accept(struct stream_connection *conn)
 464 {
 465         struct kdc_socket *kdc_socket;
 466         struct kdc_tcp_connection *kdc_conn;
 467         struct tevent_req *subreq;
 468         int rc;
 469
 470         kdc_conn = talloc_zero(conn, struct kdc_tcp_connection);
 471         if (kdc_conn == NULL) {
 472                 stream_terminate_connection(conn,
 473                                 "kdc_tcp_accept: out of memory");
 474                 return;
 475         }
 476
 477         kdc_conn->send_queue = tevent_queue_create(conn, "kdc_tcp_accept");
 478         if (kdc_conn->send_queue == NULL) {
 479                 stream_terminate_connection(conn,
 480                                 "kdc_tcp_accept: out of memory");
 481                 return;
 482         }
 483
 484         kdc_socket = talloc_get_type(conn->private_data, struct kdc_socket);
 485
 486         TALLOC_FREE(conn->event.fde);
 487
 488         rc = tstream_bsd_existing_socket(kdc_conn,
 489                         socket_get_fd(conn->socket),
 490                         &kdc_conn->tstream);
 491         if (rc < 0) {
 492                 stream_terminate_connection(conn,
 493                                 "kdc_tcp_accept: out of memory");
 494                 return;
 495         }
 496
 497         kdc_conn->conn = conn;
 498         kdc_conn->kdc_socket = kdc_socket;
 499         conn->private_data = kdc_conn;
 500
 501         /*
 502          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 503          * packet_full_request_u32 provides the pdu length then.
 504          */
 505         subreq = tstream_read_pdu_blob_send(kdc_conn,
 506                                             kdc_conn->conn->event.ctx,
 507                                             kdc_conn->tstream,
 508                                             4, /* initial_read_size */
 509                                             packet_full_request_u32,
 510                                             kdc_conn);
 511         if (subreq == NULL) {
 512                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_accept: "
 513                                 "no memory for tstream_read_pdu_blob_send");
 514                 return;
 515         }
 516         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 517 }
 518
 519 static void kdc_tcp_recv(struct stream_connection *conn, uint16_t flags)
 520 {
 521         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
 522                                                              struct kdc_tcp_connection);
 523         /* this should never be triggered! */
 524         kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_recv: called");
 525 }
 526
 527 static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
 528 {
 529         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
 530                                                              struct kdc_tcp_connection);
 531         /* this should never be triggered! */
 532         kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_send: called");
 533 }
 534
 535 static const struct stream_server_ops kdc_tcp_stream_ops = {
 536         .name                   = "kdc_tcp",
 537         .accept_connection      = kdc_tcp_accept,
 538         .recv_handler           = kdc_tcp_recv,
 539         .send_handler           = kdc_tcp_send
 540 };
 541
 542 /*
 543  * Start listening on the given address
 544  */
 545 NTSTATUS kdc_add_socket(struct kdc_server *kdc,
 546                         const struct model_ops *model_ops,
 547                         const char *name,
 548                         const char *address,
 549                         uint16_t port,
 550                         kdc_process_fn_t process,
 551                         bool udp_only)
 552 {
 553         struct kdc_socket *kdc_socket;
 554         struct kdc_udp_socket *kdc_udp_socket;
 555         struct tevent_req *udpsubreq;
 556         NTSTATUS status;
 557         int ret;
 558
 559         kdc_socket = talloc(kdc, struct kdc_socket);
 560         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 561
 562         kdc_socket->kdc = kdc;
 563         kdc_socket->process = process;
 564
 565         ret = tsocket_address_inet_from_strings(kdc_socket, "ip",
 566                                                 address, port,
 567                                                 &kdc_socket->local_address);
 568         if (ret != 0) {
 569                 status = map_nt_error_from_unix_common(errno);
 570                 return status;
 571         }
 572
 573         if (!udp_only) {
 574                 status = stream_setup_socket(kdc->task,
 575                                              kdc->task->event_ctx,
 576                                              kdc->task->lp_ctx,
 577                                              model_ops,
 578                                              &kdc_tcp_stream_ops,
 579                                              "ip", address, &port,
 580                                              lpcfg_socket_options(kdc->task->lp_ctx),
 581                                              kdc_socket,
 582                                              kdc->task->process_context);
 583                 if (!NT_STATUS_IS_OK(status)) {
 584                         DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 585                                  address, port, nt_errstr(status)));
 586                         talloc_free(kdc_socket);
 587                         return status;
 588                 }
 589         }
 590
 591         kdc_udp_socket = talloc(kdc_socket, struct kdc_udp_socket);
 592         NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket);
 593
 594         kdc_udp_socket->kdc_socket = kdc_socket;
 595
 596         ret = tdgram_inet_udp_socket(kdc_socket->local_address,
 597                                      NULL,
 598                                      kdc_udp_socket,
 599                                      &kdc_udp_socket->dgram);
 600         if (ret != 0) {
 601                 status = map_nt_error_from_unix_common(errno);
 602                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 603                          address, port, nt_errstr(status)));
 604                 return status;
 605         }
 606
 607         kdc_udp_socket->send_queue = tevent_queue_create(kdc_udp_socket,
 608                                                          "kdc_udp_send_queue");
 609         NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket->send_queue);
 610
 611         udpsubreq = tdgram_recvfrom_send(kdc_udp_socket,
 612                                          kdc->task->event_ctx,
 613                                          kdc_udp_socket->dgram);
 614         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 615         tevent_req_set_callback(udpsubreq, kdc_udp_call_loop, kdc_udp_socket);
 616
 617         return NT_STATUS_OK;
 618 }