source3/smbd/smb2_sesssetup.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   6    Copyright (C) Jeremy Allison 2010
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../libcli/smb/smb_common.h"
  26 #include "../auth/gensec/gensec.h"
  27 #include "auth.h"
  28 #include "../lib/tsocket/tsocket.h"
  29 #include "../libcli/security/security.h"
  30 #include "../lib/util/tevent_ntstatus.h"
  31
  32 static struct tevent_req *smbd_smb2_session_setup_send(TALLOC_CTX *mem_ctx,
  33                                         struct tevent_context *ev,
  34                                         struct smbd_smb2_request *smb2req,
  35                                         uint64_t in_session_id,
  36                                         uint8_t in_flags,
  37                                         uint8_t in_security_mode,
  38                                         uint64_t in_previous_session_id,
  39                                         DATA_BLOB in_security_buffer);
  40 static NTSTATUS smbd_smb2_session_setup_recv(struct tevent_req *req,
  41                                         uint16_t *out_session_flags,
  42                                         TALLOC_CTX *mem_ctx,
  43                                         DATA_BLOB *out_security_buffer,
  44                                         uint64_t *out_session_id);
  45
  46 static void smbd_smb2_request_sesssetup_done(struct tevent_req *subreq);
  47
  48 NTSTATUS smbd_smb2_request_process_sesssetup(struct smbd_smb2_request *smb2req)
  49 {
  50         const uint8_t *inhdr;
  51         const uint8_t *inbody;
  52         int i = smb2req->current_idx;
  53         uint64_t in_session_id;
  54         uint8_t in_flags;
  55         uint8_t in_security_mode;
  56         uint64_t in_previous_session_id;
  57         uint16_t in_security_offset;
  58         uint16_t in_security_length;
  59         DATA_BLOB in_security_buffer;
  60         NTSTATUS status;
  61         struct tevent_req *subreq;
  62
  63         status = smbd_smb2_request_verify_sizes(smb2req, 0x19);
  64         if (!NT_STATUS_IS_OK(status)) {
  65                 return smbd_smb2_request_error(smb2req, status);
  66         }
  67         inhdr = (const uint8_t *)smb2req->in.vector[i+0].iov_base;
  68         inbody = (const uint8_t *)smb2req->in.vector[i+1].iov_base;
  69
  70         in_session_id = BVAL(inhdr, SMB2_HDR_SESSION_ID);
  71
  72         in_flags = CVAL(inbody, 0x02);
  73         in_security_mode = CVAL(inbody, 0x03);
  74         /* Capabilities = IVAL(inbody, 0x04) */
  75         /* Channel = IVAL(inbody, 0x08) */
  76         in_security_offset = SVAL(inbody, 0x0C);
  77         in_security_length = SVAL(inbody, 0x0E);
  78         in_previous_session_id = BVAL(inbody, 0x10);
  79
  80         if (in_security_offset != (SMB2_HDR_BODY + smb2req->in.vector[i+1].iov_len)) {
  81                 return smbd_smb2_request_error(smb2req, NT_STATUS_INVALID_PARAMETER);
  82         }
  83
  84         if (in_security_length > smb2req->in.vector[i+2].iov_len) {
  85                 return smbd_smb2_request_error(smb2req, NT_STATUS_INVALID_PARAMETER);
  86         }
  87
  88         in_security_buffer.data = (uint8_t *)smb2req->in.vector[i+2].iov_base;
  89         in_security_buffer.length = in_security_length;
  90
  91         subreq = smbd_smb2_session_setup_send(smb2req,
  92                                               smb2req->sconn->ev_ctx,
  93                                               smb2req,
  94                                               in_session_id,
  95                                               in_flags,
  96                                               in_security_mode,
  97                                               in_previous_session_id,
  98                                               in_security_buffer);
  99         if (subreq == NULL) {
 100                 return smbd_smb2_request_error(smb2req, NT_STATUS_NO_MEMORY);
 101         }
 102         tevent_req_set_callback(subreq, smbd_smb2_request_sesssetup_done, smb2req);
 103
 104         return smbd_smb2_request_pending_queue(smb2req, subreq, 500);
 105 }
 106
 107 static void smbd_smb2_request_sesssetup_done(struct tevent_req *subreq)
 108 {
 109         struct smbd_smb2_request *smb2req =
 110                 tevent_req_callback_data(subreq,
 111                 struct smbd_smb2_request);
 112         int i = smb2req->current_idx;
 113         uint8_t *outhdr;
 114         DATA_BLOB outbody;
 115         DATA_BLOB outdyn;
 116         uint16_t out_session_flags;
 117         uint64_t out_session_id;
 118         uint16_t out_security_offset;
 119         DATA_BLOB out_security_buffer = data_blob_null;
 120         NTSTATUS status;
 121         NTSTATUS error; /* transport error */
 122
 123         status = smbd_smb2_session_setup_recv(subreq,
 124                                               &out_session_flags,
 125                                               smb2req,
 126                                               &out_security_buffer,
 127                                               &out_session_id);
 128         TALLOC_FREE(subreq);
 129         if (!NT_STATUS_IS_OK(status) &&
 130             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 131                 status = nt_status_squash(status);
 132                 error = smbd_smb2_request_error(smb2req, status);
 133                 if (!NT_STATUS_IS_OK(error)) {
 134                         smbd_server_connection_terminate(smb2req->sconn,
 135                                                          nt_errstr(error));
 136                         return;
 137                 }
 138                 return;
 139         }
 140
 141         out_security_offset = SMB2_HDR_BODY + 0x08;
 142
 143         outhdr = (uint8_t *)smb2req->out.vector[i].iov_base;
 144
 145         outbody = data_blob_talloc(smb2req->out.vector, NULL, 0x08);
 146         if (outbody.data == NULL) {
 147                 error = smbd_smb2_request_error(smb2req, NT_STATUS_NO_MEMORY);
 148                 if (!NT_STATUS_IS_OK(error)) {
 149                         smbd_server_connection_terminate(smb2req->sconn,
 150                                                          nt_errstr(error));
 151                         return;
 152                 }
 153                 return;
 154         }
 155
 156         SBVAL(outhdr, SMB2_HDR_SESSION_ID, out_session_id);
 157
 158         SSVAL(outbody.data, 0x00, 0x08 + 1);    /* struct size */
 159         SSVAL(outbody.data, 0x02,
 160               out_session_flags);               /* session flags */
 161         SSVAL(outbody.data, 0x04,
 162               out_security_offset);             /* security buffer offset */
 163         SSVAL(outbody.data, 0x06,
 164               out_security_buffer.length);      /* security buffer length */
 165
 166         outdyn = out_security_buffer;
 167
 168         error = smbd_smb2_request_done_ex(smb2req, status, outbody, &outdyn,
 169                                            __location__);
 170         if (!NT_STATUS_IS_OK(error)) {
 171                 smbd_server_connection_terminate(smb2req->sconn,
 172                                                  nt_errstr(error));
 173                 return;
 174         }
 175 }
 176
 177 static int smbd_smb2_session_destructor(struct smbd_smb2_session *session)
 178 {
 179         if (session->sconn == NULL) {
 180                 return 0;
 181         }
 182
 183         file_close_user(session->sconn, session->vuid);
 184
 185         /* first free all tcons */
 186         while (session->tcons.list) {
 187                 talloc_free(session->tcons.list);
 188         }
 189
 190         idr_remove(session->sconn->smb2.sessions.idtree, session->vuid);
 191         DLIST_REMOVE(session->sconn->smb2.sessions.list, session);
 192         invalidate_vuid(session->sconn, session->vuid);
 193
 194         session->vuid = 0;
 195         session->status = NT_STATUS_USER_SESSION_DELETED;
 196         session->sconn = NULL;
 197
 198         return 0;
 199 }
 200
 201 static NTSTATUS smbd_smb2_auth_generic_return(struct smbd_smb2_session *session,
 202                                         struct smbd_smb2_request *smb2req,
 203                                         uint8_t in_security_mode,
 204                                         uint64_t in_previous_session_id,
 205                                         DATA_BLOB in_security_buffer,
 206                                         uint16_t *out_session_flags,
 207                                         uint64_t *out_session_id)
 208 {
 209         bool guest = false;
 210
 211         if ((in_security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) ||
 212             lp_server_signing() == SMB_SIGNING_REQUIRED) {
 213                 session->do_signing = true;
 214         }
 215
 216         if (security_session_user_level(session->session_info, NULL) < SECURITY_USER) {
 217                 /* we map anonymous to guest internally */
 218                 *out_session_flags |= SMB2_SESSION_FLAG_IS_GUEST;
 219                 *out_session_flags |= SMB2_SESSION_FLAG_IS_NULL;
 220                 /* force no signing */
 221                 session->do_signing = false;
 222                 guest = true;
 223         }
 224
 225         session->session_key = session->session_info->session_key;
 226
 227         session->compat_vuser = talloc_zero(session, struct user_struct);
 228         if (session->compat_vuser == NULL) {
 229                 TALLOC_FREE(session);
 230                 return NT_STATUS_NO_MEMORY;
 231         }
 232         session->compat_vuser->gensec_security = session->gensec_security;
 233         session->compat_vuser->homes_snum = -1;
 234         session->compat_vuser->session_info = session->session_info;
 235         session->compat_vuser->session_keystr = NULL;
 236         session->compat_vuser->vuid = session->vuid;
 237         DLIST_ADD(session->sconn->users, session->compat_vuser);
 238         session->sconn->num_users++;
 239
 240         if (security_session_user_level(session->session_info, NULL) >= SECURITY_USER) {
 241                 session->compat_vuser->homes_snum =
 242                         register_homes_share(session->session_info->unix_info->unix_name);
 243         }
 244
 245         if (!session_claim(session->sconn, session->compat_vuser)) {
 246                 DEBUG(1, ("smb2: Failed to claim session "
 247                         "for vuid=%d\n",
 248                         session->compat_vuser->vuid));
 249                 TALLOC_FREE(session);
 250                 return NT_STATUS_LOGON_FAILURE;
 251         }
 252
 253         set_current_user_info(session->session_info->unix_info->sanitized_username,
 254                               session->session_info->unix_info->unix_name,
 255                               session->session_info->info->domain_name);
 256
 257         reload_services(smb2req->sconn, conn_snum_used, true);
 258
 259         session->status = NT_STATUS_OK;
 260
 261         /*
 262          * we attach the session to the request
 263          * so that the response can be signed
 264          */
 265         smb2req->session = session;
 266         if (!guest) {
 267                 smb2req->do_signing = true;
 268         }
 269
 270         global_client_caps |= (CAP_LEVEL_II_OPLOCKS|CAP_STATUS32);
 271
 272         *out_session_id = session->vuid;
 273
 274         return NT_STATUS_OK;
 275 }
 276
 277 static NTSTATUS smbd_smb2_auth_generic(struct smbd_smb2_session *session,
 278                                        struct smbd_smb2_request *smb2req,
 279                                        uint8_t in_security_mode,
 280                                        uint64_t in_previous_session_id,
 281                                        DATA_BLOB in_security_buffer,
 282                                        uint16_t *out_session_flags,
 283                                        DATA_BLOB *out_security_buffer,
 284                                        uint64_t *out_session_id)
 285 {
 286         NTSTATUS status;
 287
 288         *out_security_buffer = data_blob_null;
 289
 290         if (session->gensec_security == NULL) {
 291                 status = auth_generic_prepare(session, session->sconn->remote_address,
 292                                             &session->gensec_security);
 293                 if (!NT_STATUS_IS_OK(status)) {
 294                         TALLOC_FREE(session);
 295                         return status;
 296                 }
 297
 298                 gensec_want_feature(session->gensec_security, GENSEC_FEATURE_SESSION_KEY);
 299                 gensec_want_feature(session->gensec_security, GENSEC_FEATURE_UNIX_TOKEN);
 300
 301                 status = gensec_start_mech_by_oid(session->gensec_security, GENSEC_OID_SPNEGO);
 302                 if (!NT_STATUS_IS_OK(status)) {
 303                         TALLOC_FREE(session);
 304                         return status;
 305                 }
 306         }
 307
 308         become_root();
 309         status = gensec_update(session->gensec_security,
 310                                smb2req, NULL,
 311                                in_security_buffer,
 312                                out_security_buffer);
 313         unbecome_root();
 314         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 315             !NT_STATUS_IS_OK(status)) {
 316                 TALLOC_FREE(session);
 317                 return nt_status_squash(status);
 318         }
 319
 320         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 321                 *out_session_id = session->vuid;
 322                 return status;
 323         }
 324
 325         status = gensec_session_info(session->gensec_security,
 326                                      session,
 327                                      &session->session_info);
 328
 329         if (!NT_STATUS_IS_OK(status)) {
 330                 TALLOC_FREE(session);
 331                 return status;
 332         }
 333         *out_session_id = session->vuid;
 334
 335         return smbd_smb2_auth_generic_return(session,
 336                                              smb2req,
 337                                              in_security_mode,
 338                                              in_previous_session_id,
 339                                              in_security_buffer,
 340                                              out_session_flags,
 341                                              out_session_id);
 342 }
 343
 344 static NTSTATUS smbd_smb2_session_setup(struct smbd_smb2_request *smb2req,
 345                                         uint64_t in_session_id,
 346                                         uint8_t in_flags,
 347                                         uint8_t in_security_mode,
 348                                         uint64_t in_previous_session_id,
 349                                         DATA_BLOB in_security_buffer,
 350                                         uint16_t *out_session_flags,
 351                                         DATA_BLOB *out_security_buffer,
 352                                         uint64_t *out_session_id)
 353 {
 354         struct smbd_smb2_session *session;
 355
 356         *out_session_flags = 0;
 357         *out_session_id = 0;
 358
 359         if (in_session_id == 0) {
 360                 int id;
 361
 362                 /* create a new session */
 363                 session = talloc_zero(smb2req->sconn, struct smbd_smb2_session);
 364                 if (session == NULL) {
 365                         return NT_STATUS_NO_MEMORY;
 366                 }
 367                 session->status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 368                 id = idr_get_new_random(smb2req->sconn->smb2.sessions.idtree,
 369                                         session,
 370                                         smb2req->sconn->smb2.sessions.limit);
 371                 if (id == -1) {
 372                         return NT_STATUS_INSUFFICIENT_RESOURCES;
 373                 }
 374                 session->vuid = id;
 375
 376                 session->tcons.idtree = idr_init(session);
 377                 if (session->tcons.idtree == NULL) {
 378                         return NT_STATUS_NO_MEMORY;
 379                 }
 380                 session->tcons.limit = 0x0000FFFE;
 381                 session->tcons.list = NULL;
 382
 383                 DLIST_ADD_END(smb2req->sconn->smb2.sessions.list, session,
 384                               struct smbd_smb2_session *);
 385                 session->sconn = smb2req->sconn;
 386                 talloc_set_destructor(session, smbd_smb2_session_destructor);
 387         } else {
 388                 void *p;
 389
 390                 /* lookup an existing session */
 391                 p = idr_find(smb2req->sconn->smb2.sessions.idtree, in_session_id);
 392                 if (p == NULL) {
 393                         return NT_STATUS_USER_SESSION_DELETED;
 394                 }
 395                 session = talloc_get_type_abort(p, struct smbd_smb2_session);
 396         }
 397
 398         if (NT_STATUS_IS_OK(session->status)) {
 399                 return NT_STATUS_REQUEST_NOT_ACCEPTED;
 400         }
 401
 402         return smbd_smb2_auth_generic(session,
 403                                       smb2req,
 404                                       in_security_mode,
 405                                       in_previous_session_id,
 406                                       in_security_buffer,
 407                                       out_session_flags,
 408                                       out_security_buffer,
 409                                       out_session_id);
 410 }
 411
 412 struct smbd_smb2_session_setup_state {
 413         struct tevent_context *ev;
 414         struct smbd_smb2_request *smb2req;
 415         uint64_t in_session_id;
 416         uint8_t in_flags;
 417         uint8_t in_security_mode;
 418         uint64_t in_previous_session_id;
 419         DATA_BLOB in_security_buffer;
 420         uint16_t out_session_flags;
 421         DATA_BLOB out_security_buffer;
 422         uint64_t out_session_id;
 423 };
 424
 425 static struct tevent_req *smbd_smb2_session_setup_send(TALLOC_CTX *mem_ctx,
 426                                         struct tevent_context *ev,
 427                                         struct smbd_smb2_request *smb2req,
 428                                         uint64_t in_session_id,
 429                                         uint8_t in_flags,
 430                                         uint8_t in_security_mode,
 431                                         uint64_t in_previous_session_id,
 432                                         DATA_BLOB in_security_buffer)
 433 {
 434         struct tevent_req *req;
 435         struct smbd_smb2_session_setup_state *state;
 436         NTSTATUS status;
 437
 438         req = tevent_req_create(mem_ctx, &state,
 439                                 struct smbd_smb2_session_setup_state);
 440         if (req == NULL) {
 441                 return NULL;
 442         }
 443         state->ev = ev;
 444         state->smb2req = smb2req;
 445         state->in_session_id = in_session_id;
 446         state->in_flags = in_flags;
 447         state->in_security_mode = in_security_mode;
 448         state->in_previous_session_id = in_previous_session_id;
 449         state->in_security_buffer = in_security_buffer;
 450
 451         status = smbd_smb2_session_setup(smb2req,
 452                                          in_session_id,
 453                                          in_flags,
 454                                          in_security_mode,
 455                                          in_previous_session_id,
 456                                          in_security_buffer,
 457                                          &state->out_session_flags,
 458                                          &state->out_security_buffer,
 459                                          &state->out_session_id);
 460         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 461             NT_STATUS_IS_OK(status))
 462         {
 463                 talloc_steal(state, state->out_security_buffer.data);
 464         }
 465         if (tevent_req_nterror(req, status)) {
 466                 return tevent_req_post(req, ev);
 467         }
 468
 469         tevent_req_done(req);
 470         return tevent_req_post(req, ev);
 471 }
 472
 473 static NTSTATUS smbd_smb2_session_setup_recv(struct tevent_req *req,
 474                                         uint16_t *out_session_flags,
 475                                         TALLOC_CTX *mem_ctx,
 476                                         DATA_BLOB *out_security_buffer,
 477                                         uint64_t *out_session_id)
 478 {
 479         struct smbd_smb2_session_setup_state *state =
 480                 tevent_req_data(req,
 481                 struct smbd_smb2_session_setup_state);
 482         NTSTATUS status;
 483
 484         if (tevent_req_is_nterror(req, &status)) {
 485                 if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 486                         tevent_req_received(req);
 487                         return nt_status_squash(status);
 488                 }
 489         } else {
 490                 status = NT_STATUS_OK;
 491         }
 492
 493         *out_session_flags = state->out_session_flags;
 494         *out_security_buffer = state->out_security_buffer;
 495         *out_session_id = state->out_session_id;
 496
 497         talloc_steal(mem_ctx, out_security_buffer->data);
 498         tevent_req_received(req);
 499         return status;
 500 }
 501
 502 NTSTATUS smbd_smb2_request_process_logoff(struct smbd_smb2_request *req)
 503 {
 504         NTSTATUS status;
 505         DATA_BLOB outbody;
 506
 507         status = smbd_smb2_request_verify_sizes(req, 0x04);
 508         if (!NT_STATUS_IS_OK(status)) {
 509                 return smbd_smb2_request_error(req, status);
 510         }
 511
 512         /*
 513          * TODO: cancel all outstanding requests on the session
 514          *       and delete all tree connections.
 515          */
 516         smbd_smb2_session_destructor(req->session);
 517         /*
 518          * we may need to sign the response, so we need to keep
 519          * the session until the response is sent to the wire.
 520          */
 521         talloc_steal(req, req->session);
 522
 523         outbody = data_blob_talloc(req->out.vector, NULL, 0x04);
 524         if (outbody.data == NULL) {
 525                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 526         }
 527
 528         SSVAL(outbody.data, 0x00, 0x04);        /* struct size */
 529         SSVAL(outbody.data, 0x02, 0);           /* reserved */
 530
 531         return smbd_smb2_request_done(req, outbody, NULL);
 532 }