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