source/ldap_server/ldap_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    LDAP server
   5
   6    Copyright (C) Andrew Tridgell 2005
   7    Copyright (C) Volker Lendecke 2004
   8    Copyright (C) Stefan Metzmacher 2004
   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 "lib/events/events.h"
  27 #include "auth/auth.h"
  28 #include "dlinklist.h"
  29 #include "asn_1.h"
  30 #include "ldap_server/ldap_server.h"
  31 #include "smbd/service_task.h"
  32 #include "smbd/service_stream.h"
  33 #include "lib/socket/socket.h"
  34 #include "lib/tls/tls.h"
  35 #include "lib/messaging/irpc.h"
  36
  37 /*
  38   close the socket and shutdown a server_context
  39 */
  40 static void ldapsrv_terminate_connection(struct ldapsrv_connection *conn,
  41                                          const char *reason)
  42 {
  43         /* we don't actually do the stream termination here as the
  44            recv/send functions dereference the connection after the
  45            packet processing callbacks. Instead we mark it for
  46            termination and do the real termination in the send/recv
  47            functions */
  48         conn->terminate = reason;
  49 }
  50
  51 /*
  52   process a decoded ldap message
  53 */
  54 static void ldapsrv_process_message(struct ldapsrv_connection *conn,
  55                                     struct ldap_message *msg)
  56 {
  57         struct ldapsrv_call *call;
  58         NTSTATUS status;
  59         DATA_BLOB blob;
  60         struct data_blob_list_item *q;
  61         BOOL enable_wrap = conn->enable_wrap;
  62
  63         call = talloc(conn, struct ldapsrv_call);
  64         if (!call) {
  65                 ldapsrv_terminate_connection(conn, "no memory");
  66                 return;
  67         }
  68
  69         call->request = talloc_steal(call, msg);
  70         call->conn = conn;
  71         call->replies = NULL;
  72
  73         /* make the call */
  74         status = ldapsrv_do_call(call);
  75         if (!NT_STATUS_IS_OK(status)) {
  76                 goto failed;
  77         }
  78
  79         blob = data_blob(NULL, 0);
  80
  81         if (call->replies == NULL) {
  82                 talloc_free(call);
  83                 return;
  84         }
  85
  86         /* build all the replies into a single blob */
  87         while (call->replies) {
  88                 DATA_BLOB b;
  89
  90                 msg = call->replies->msg;
  91                 if (!ldap_encode(msg, &b, call)) {
  92                         DEBUG(0,("Failed to encode ldap reply of type %d\n", msg->type));
  93                         goto failed;
  94                 }
  95
  96                 status = data_blob_append(call, &blob, b.data, b.length);
  97                 data_blob_free(&b);
  98
  99                 if (!NT_STATUS_IS_OK(status)) goto failed;
 100
 101                 DLIST_REMOVE(call->replies, call->replies);
 102         }
 103
 104         /* possibly encrypt/sign the reply */
 105         if (enable_wrap) {
 106                 DATA_BLOB wrapped;
 107
 108                 status = gensec_wrap(conn->gensec, call, &blob, &wrapped);
 109                 if (!NT_STATUS_IS_OK(status)) {
 110                         goto failed;
 111                 }
 112                 data_blob_free(&blob);
 113                 blob = data_blob_talloc(call, NULL, wrapped.length + 4);
 114                 if (blob.data == NULL) {
 115                         goto failed;
 116                 }
 117                 RSIVAL(blob.data, 0, wrapped.length);
 118                 memcpy(blob.data+4, wrapped.data, wrapped.length);
 119                 data_blob_free(&wrapped);
 120         }
 121
 122         q = talloc(conn, struct data_blob_list_item);
 123         if (q == NULL) goto failed;
 124
 125         q->blob = blob;
 126         talloc_steal(q, blob.data);
 127
 128         if (conn->send_queue == NULL) {
 129                 EVENT_FD_WRITEABLE(conn->connection->event.fde);
 130         }
 131         DLIST_ADD_END(conn->send_queue, q, struct data_blob_list_item *);
 132         talloc_free(call);
 133         return;
 134
 135 failed:
 136         talloc_free(call);
 137 }
 138
 139
 140 /*
 141   try and decode the partial input buffer
 142 */
 143 static void ldapsrv_try_decode_plain(struct ldapsrv_connection *conn)
 144 {
 145         struct asn1_data asn1;
 146
 147         if (!asn1_load(&asn1, conn->partial)) {
 148                 ldapsrv_terminate_connection(conn, "out of memory");
 149                 return;
 150         }
 151
 152         /* try and decode - this will fail if we don't have a full packet yet */
 153         while (asn1.ofs < asn1.length) {
 154                 struct ldap_message *msg = talloc(conn, struct ldap_message);
 155                 off_t saved_ofs = asn1.ofs;
 156
 157                 if (msg == NULL) {
 158                         ldapsrv_terminate_connection(conn, "out of memory");
 159                         return;
 160                 }
 161
 162                 if (ldap_decode(&asn1, msg)) {
 163                         ldapsrv_process_message(conn, msg);
 164                 } else {
 165                         if (asn1.ofs < asn1.length) {
 166                                 ldapsrv_terminate_connection(conn, "ldap_decode failed");
 167                                 return;
 168                         }
 169                         asn1.ofs = saved_ofs;
 170                         talloc_free(msg);
 171                         break;
 172                 }
 173         }
 174
 175         /* keep any remaining data in conn->partial */
 176         data_blob_free(&conn->partial);
 177         if (asn1.ofs != asn1.length) {
 178                 conn->partial = data_blob_talloc(conn,
 179                                                  asn1.data + asn1.ofs,
 180                                                  asn1.length - asn1.ofs);
 181         }
 182         asn1_free(&asn1);
 183 }
 184
 185
 186 /*
 187   try and decode/process wrapped data
 188 */
 189 static void ldapsrv_try_decode_wrapped(struct ldapsrv_connection *conn)
 190 {
 191         uint32_t len;
 192
 193         /* keep decoding while we have a full wrapped packet */
 194         while (conn->partial.length >= 4 &&
 195                (len=RIVAL(conn->partial.data, 0)) <= conn->partial.length-4) {
 196                 DATA_BLOB wrapped, unwrapped;
 197                 struct asn1_data asn1;
 198                 struct ldap_message *msg = talloc(conn, struct ldap_message);
 199                 NTSTATUS status;
 200
 201                 if (msg == NULL) {
 202                         ldapsrv_terminate_connection(conn, "out of memory");
 203                         return;
 204                 }
 205
 206                 wrapped.data   = conn->partial.data+4;
 207                 wrapped.length = len;
 208
 209                 status = gensec_unwrap(conn->gensec, msg, &wrapped, &unwrapped);
 210                 if (!NT_STATUS_IS_OK(status)) {
 211                         ldapsrv_terminate_connection(conn, "gensec unwrap failed");
 212                         return;
 213                 }
 214
 215                 if (!asn1_load(&asn1, unwrapped)) {
 216                         ldapsrv_terminate_connection(conn, "out of memory");
 217                         return;
 218                 }
 219
 220                 while (ldap_decode(&asn1, msg)) {
 221                         ldapsrv_process_message(conn, msg);
 222                         msg = talloc(conn, struct ldap_message);
 223                 }
 224
 225                 if (asn1.ofs < asn1.length) {
 226                         ldapsrv_terminate_connection(conn, "ldap_decode failed");
 227                         return;
 228                 }
 229
 230                 talloc_free(msg);
 231                 asn1_free(&asn1);
 232
 233                 if (conn->partial.length == len + 4) {
 234                         data_blob_free(&conn->partial);
 235                 } else {
 236                         memmove(conn->partial.data, conn->partial.data+len+4,
 237                                 conn->partial.length - (len+4));
 238                         conn->partial.length -= len + 4;
 239                 }
 240         }
 241 }
 242
 243
 244 /*
 245   called when a LDAP socket becomes readable
 246 */
 247 static void ldapsrv_recv(struct stream_connection *c, uint16_t flags)
 248 {
 249         struct ldapsrv_connection *conn =
 250                 talloc_get_type(c->private, struct ldapsrv_connection);
 251         NTSTATUS status;
 252         size_t npending, nread;
 253
 254         if (conn->processing) {
 255                 EVENT_FD_NOT_READABLE(c->event.fde);
 256                 return;
 257         }
 258
 259         /* work out how much data is pending */
 260         status = tls_socket_pending(conn->tls, &npending);
 261         if (!NT_STATUS_IS_OK(status)) {
 262                 ldapsrv_terminate_connection(conn, "socket_pending() failed");
 263                 return;
 264         }
 265         if (npending == 0) {
 266                 ldapsrv_terminate_connection(conn, "EOF from client");
 267                 return;
 268         }
 269
 270         conn->partial.data = talloc_realloc_size(conn, conn->partial.data,
 271                                                  conn->partial.length + npending);
 272         if (conn->partial.data == NULL) {
 273                 ldapsrv_terminate_connection(conn, "out of memory");
 274                 return;
 275         }
 276
 277         /* receive the data */
 278         status = tls_socket_recv(conn->tls, conn->partial.data + conn->partial.length,
 279                                  npending, &nread);
 280         if (NT_STATUS_IS_ERR(status)) {
 281                 ldapsrv_terminate_connection(conn, "socket_recv() failed");
 282                 return;
 283         }
 284         if (!NT_STATUS_IS_OK(status)) {
 285                 return;
 286         }
 287         if (nread == 0) {
 288                 ldapsrv_terminate_connection(conn, "EOF from client");
 289                 return;
 290         }
 291         conn->partial.length += nread;
 292
 293         conn->processing = True;
 294         /* see if we can decode what we have */
 295         if (conn->enable_wrap) {
 296                 ldapsrv_try_decode_wrapped(conn);
 297         } else {
 298                 ldapsrv_try_decode_plain(conn);
 299         }
 300         conn->processing = False;
 301
 302         EVENT_FD_READABLE(c->event.fde);
 303
 304         if (conn->terminate) {
 305                 if (conn->tls) {
 306                         talloc_free(conn->tls);
 307                         conn->tls = NULL;
 308                 }
 309                 stream_terminate_connection(conn->connection, conn->terminate);
 310         }
 311 }
 312
 313 /*
 314   called when a LDAP socket becomes writable
 315 */
 316 static void ldapsrv_send(struct stream_connection *c, uint16_t flags)
 317 {
 318         struct ldapsrv_connection *conn =
 319                 talloc_get_type(c->private, struct ldapsrv_connection);
 320         while (conn->send_queue) {
 321                 struct data_blob_list_item *q = conn->send_queue;
 322                 size_t nsent;
 323                 NTSTATUS status;
 324
 325                 status = tls_socket_send(conn->tls, &q->blob, &nsent);
 326                 if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
 327                         break;
 328                 }
 329                 if (!NT_STATUS_IS_OK(status)) {
 330                         ldapsrv_terminate_connection(conn, "socket_send error");
 331                         return;
 332                 }
 333
 334                 q->blob.data += nsent;
 335                 q->blob.length -= nsent;
 336                 if (q->blob.length == 0) {
 337                         DLIST_REMOVE(conn->send_queue, q);
 338                 }
 339         }
 340         if (conn->send_queue == NULL) {
 341                 EVENT_FD_NOT_WRITEABLE(c->event.fde);
 342         }
 343
 344         if (conn->terminate) {
 345                 if (conn->tls) {
 346                         talloc_free(conn->tls);
 347                         conn->tls = NULL;
 348                 }
 349                 stream_terminate_connection(conn->connection, conn->terminate);
 350         }
 351 }
 352
 353 /*
 354   initialise a server_context from a open socket and register a event handler
 355   for reading from that socket
 356 */
 357 static void ldapsrv_accept(struct stream_connection *c)
 358 {
 359         struct ldapsrv_partition *rootDSE_part;
 360         struct ldapsrv_partition *part;
 361         struct ldapsrv_service *ldapsrv_service =
 362                 talloc_get_type(c->private, struct ldapsrv_service);
 363         struct ldapsrv_connection *conn;
 364         int port;
 365
 366         conn = talloc_zero(c, struct ldapsrv_connection);
 367         if (!conn) {
 368                 stream_terminate_connection(c, "ldapsrv_accept: out of memory");
 369                 return;
 370         }
 371
 372         conn->enable_wrap = False;
 373         conn->partial     = data_blob(NULL, 0);
 374         conn->send_queue  = NULL;
 375         conn->connection  = c;
 376         conn->service     = ldapsrv_service;
 377         conn->processing  = False;
 378         c->private        = conn;
 379
 380         port = socket_get_my_port(c->socket);
 381
 382         /* note that '0' is a ASN1_SEQUENCE(0), which is the first byte on
 383            any ldap connection */
 384         conn->tls = tls_init_server(ldapsrv_service->tls_params, c->socket,
 385                                     c->event.fde, NULL, port != 389);
 386         if (!conn->tls) {
 387                 ldapsrv_terminate_connection(conn, "ldapsrv_accept: tls_init_server() failed");
 388                 return;
 389         }
 390
 391         /* Connections start out anonymous */
 392         if (!NT_STATUS_IS_OK(auth_anonymous_session_info(conn, &conn->session_info))) {
 393                 ldapsrv_terminate_connection(conn, "failed to setup anonymous session info");
 394                 return;
 395         }
 396
 397         rootDSE_part = talloc(conn, struct ldapsrv_partition);
 398         if (rootDSE_part == NULL) {
 399                 ldapsrv_terminate_connection(conn, "talloc failed");
 400                 return;
 401         }
 402
 403         rootDSE_part->base_dn = ""; /* RootDSE */
 404         rootDSE_part->ops = ldapsrv_get_rootdse_partition_ops();
 405         if (!NT_STATUS_IS_OK(rootDSE_part->ops->Init(rootDSE_part, conn))) {
 406                 ldapsrv_terminate_connection(conn, "rootDSE Init failed");
 407         }
 408
 409         conn->rootDSE = rootDSE_part;
 410         DLIST_ADD_END(conn->partitions, rootDSE_part, struct ldapsrv_partition *);
 411
 412         part = talloc(conn, struct ldapsrv_partition);
 413         if (part == NULL) {
 414                 ldapsrv_terminate_connection(conn, "talloc failed");
 415                 return;
 416         }
 417
 418         part->base_dn = "*"; /* default partition */
 419         part->ops = ldapsrv_get_sldb_partition_ops();
 420         if (!NT_STATUS_IS_OK(part->ops->Init(part, conn))) {
 421                 ldapsrv_terminate_connection(conn, "default partition Init failed");
 422         }
 423
 424         conn->default_partition = part;
 425         DLIST_ADD_END(conn->partitions, part, struct ldapsrv_partition *);
 426
 427         irpc_add_name(c->msg_ctx, "ldap_server");
 428 }
 429
 430 static const struct stream_server_ops ldap_stream_ops = {
 431         .name                   = "ldap",
 432         .accept_connection      = ldapsrv_accept,
 433         .recv_handler           = ldapsrv_recv,
 434         .send_handler           = ldapsrv_send,
 435 };
 436
 437 /*
 438   add a socket address to the list of events, one event per port
 439 */
 440 static NTSTATUS add_socket(struct event_context *event_context,
 441                            const struct model_ops *model_ops,
 442                            const char *address, struct ldapsrv_service *ldap_service)
 443 {
 444         uint16_t port = 389;
 445         NTSTATUS status;
 446
 447         status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 448                                      "ipv4", address, &port, ldap_service);
 449         if (!NT_STATUS_IS_OK(status)) {
 450                 DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 451                          address, port, nt_errstr(status)));
 452         }
 453
 454         if (tls_support(ldap_service->tls_params)) {
 455                 /* add ldaps server */
 456                 port = 636;
 457                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 458                                              "ipv4", address, &port, ldap_service);
 459                 if (!NT_STATUS_IS_OK(status)) {
 460                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 461                                  address, port, nt_errstr(status)));
 462                 }
 463         }
 464
 465         return status;
 466 }
 467
 468 /*
 469   open the ldap server sockets
 470 */
 471 static void ldapsrv_task_init(struct task_server *task)
 472 {
 473         struct ldapsrv_service *ldap_service;
 474         NTSTATUS status;
 475
 476         ldap_service = talloc_zero(task, struct ldapsrv_service);
 477         if (ldap_service == NULL) goto failed;
 478
 479         ldap_service->tls_params = tls_initialise(ldap_service);
 480         if (ldap_service->tls_params == NULL) goto failed;
 481
 482         if (lp_interfaces() && lp_bind_interfaces_only()) {
 483                 int num_interfaces = iface_count();
 484                 int i;
 485
 486                 /* We have been given an interfaces line, and been
 487                    told to only bind to those interfaces. Create a
 488                    socket per interface and bind to only these.
 489                 */
 490                 for(i = 0; i < num_interfaces; i++) {
 491                         const char *address = iface_n_ip(i);
 492                         status = add_socket(task->event_ctx, task->model_ops, address, ldap_service);
 493                         if (!NT_STATUS_IS_OK(status)) goto failed;
 494                 }
 495         } else {
 496                 status = add_socket(task->event_ctx, task->model_ops, lp_socket_address(), ldap_service);
 497                 if (!NT_STATUS_IS_OK(status)) goto failed;
 498         }
 499
 500         return;
 501
 502 failed:
 503         task_server_terminate(task, "Failed to startup ldap server task");
 504 }
 505
 506 /*
 507   called on startup of the web server service It's job is to start
 508   listening on all configured sockets
 509 */
 510 static NTSTATUS ldapsrv_init(struct event_context *event_context,
 511                              const struct model_ops *model_ops)
 512 {
 513         return task_server_startup(event_context, model_ops, ldapsrv_task_init);
 514 }
 515
 516
 517 NTSTATUS server_service_ldap_init(void)
 518 {
 519         return register_server_service("ldap", ldapsrv_init);
 520 }