source3/smbd/smb2_read.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/filesys.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../libcli/smb/smb_common.h"
  26 #include "libcli/security/security.h"
  27 #include "../lib/util/tevent_ntstatus.h"
  28 #include "rpc_server/srv_pipe_hnd.h"
  29 #include "lib/util/sys_rw_data.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_SMB2
  33
  34 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
  35                                               struct tevent_context *ev,
  36                                               struct smbd_smb2_request *smb2req,
  37                                               struct files_struct *in_fsp,
  38                                               uint8_t in_flags,
  39                                               uint32_t in_length,
  40                                               uint64_t in_offset,
  41                                               uint32_t in_minimum,
  42                                               uint32_t in_remaining);
  43 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
  44                                     TALLOC_CTX *mem_ctx,
  45                                     DATA_BLOB *out_data,
  46                                     uint32_t *out_remaining);
  47
  48 static void smbd_smb2_request_read_done(struct tevent_req *subreq);
  49 NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
  50 {
  51         struct smbXsrv_connection *xconn = req->xconn;
  52         NTSTATUS status;
  53         const uint8_t *inbody;
  54         uint8_t in_flags;
  55         uint32_t in_length;
  56         uint64_t in_offset;
  57         uint64_t in_file_id_persistent;
  58         uint64_t in_file_id_volatile;
  59         struct files_struct *in_fsp;
  60         uint32_t in_minimum_count;
  61         uint32_t in_remaining_bytes;
  62         struct tevent_req *subreq;
  63
  64         status = smbd_smb2_request_verify_sizes(req, 0x31);
  65         if (!NT_STATUS_IS_OK(status)) {
  66                 return smbd_smb2_request_error(req, status);
  67         }
  68         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  69
  70         if (xconn->protocol >= PROTOCOL_SMB3_02) {
  71                 in_flags                = CVAL(inbody, 0x03);
  72         } else {
  73                 in_flags                = 0;
  74         }
  75         in_length               = IVAL(inbody, 0x04);
  76         in_offset               = BVAL(inbody, 0x08);
  77         in_file_id_persistent   = BVAL(inbody, 0x10);
  78         in_file_id_volatile     = BVAL(inbody, 0x18);
  79         in_minimum_count        = IVAL(inbody, 0x20);
  80         in_remaining_bytes      = IVAL(inbody, 0x28);
  81
  82         /* check the max read size */
  83         if (in_length > xconn->smb2.server.max_read) {
  84                 DEBUG(2,("smbd_smb2_request_process_read: "
  85                          "client ignored max read: %s: 0x%08X: 0x%08X\n",
  86                         __location__, in_length, xconn->smb2.server.max_read));
  87                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  88         }
  89
  90         status = smbd_smb2_request_verify_creditcharge(req, in_length);
  91         if (!NT_STATUS_IS_OK(status)) {
  92                 return smbd_smb2_request_error(req, status);
  93         }
  94
  95         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  96         if (in_fsp == NULL) {
  97                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  98         }
  99
 100         subreq = smbd_smb2_read_send(req, req->sconn->ev_ctx,
 101                                      req, in_fsp,
 102                                      in_flags,
 103                                      in_length,
 104                                      in_offset,
 105                                      in_minimum_count,
 106                                      in_remaining_bytes);
 107         if (subreq == NULL) {
 108                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 109         }
 110         tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
 111
 112         return smbd_smb2_request_pending_queue(req, subreq, 500);
 113 }
 114
 115 static void smbd_smb2_request_read_done(struct tevent_req *subreq)
 116 {
 117         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 118                                         struct smbd_smb2_request);
 119         DATA_BLOB outbody;
 120         DATA_BLOB outdyn;
 121         uint8_t out_data_offset;
 122         DATA_BLOB out_data_buffer = data_blob_null;
 123         uint32_t out_data_remaining = 0;
 124         NTSTATUS status;
 125         NTSTATUS error; /* transport error */
 126
 127         status = smbd_smb2_read_recv(subreq,
 128                                      req,
 129                                      &out_data_buffer,
 130                                      &out_data_remaining);
 131         TALLOC_FREE(subreq);
 132         if (!NT_STATUS_IS_OK(status)) {
 133                 error = smbd_smb2_request_error(req, status);
 134                 if (!NT_STATUS_IS_OK(error)) {
 135                         smbd_server_connection_terminate(req->xconn,
 136                                                          nt_errstr(error));
 137                         return;
 138                 }
 139                 return;
 140         }
 141
 142         out_data_offset = SMB2_HDR_BODY + 0x10;
 143
 144         outbody = smbd_smb2_generate_outbody(req, 0x10);
 145         if (outbody.data == NULL) {
 146                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 147                 if (!NT_STATUS_IS_OK(error)) {
 148                         smbd_server_connection_terminate(req->xconn,
 149                                                          nt_errstr(error));
 150                         return;
 151                 }
 152                 return;
 153         }
 154
 155         SSVAL(outbody.data, 0x00, 0x10 + 1);    /* struct size */
 156         SCVAL(outbody.data, 0x02,
 157               out_data_offset);                 /* data offset */
 158         SCVAL(outbody.data, 0x03, 0);           /* reserved */
 159         SIVAL(outbody.data, 0x04,
 160               out_data_buffer.length);          /* data length */
 161         SIVAL(outbody.data, 0x08,
 162               out_data_remaining);              /* data remaining */
 163         SIVAL(outbody.data, 0x0C, 0);           /* reserved */
 164
 165         outdyn = out_data_buffer;
 166
 167         error = smbd_smb2_request_done(req, outbody, &outdyn);
 168         if (!NT_STATUS_IS_OK(error)) {
 169                 smbd_server_connection_terminate(req->xconn,
 170                                                  nt_errstr(error));
 171                 return;
 172         }
 173 }
 174
 175 struct smbd_smb2_read_state {
 176         struct smbd_smb2_request *smb2req;
 177         struct smb_request *smbreq;
 178         files_struct *fsp;
 179         uint8_t in_flags;
 180         uint32_t in_length;
 181         uint64_t in_offset;
 182         uint32_t in_minimum;
 183         DATA_BLOB out_headers;
 184         uint8_t _out_hdr_buf[NBT_HDR_SIZE + SMB2_HDR_BODY + 0x10];
 185         DATA_BLOB out_data;
 186         uint32_t out_remaining;
 187 };
 188
 189 static int smb2_smb2_read_state_deny_destructor(struct smbd_smb2_read_state *state)
 190 {
 191         return -1;
 192 }
 193
 194 /* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
 195 static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
 196 {
 197         struct lock_struct lock;
 198         uint32_t in_length = state->in_length;
 199         uint64_t in_offset = state->in_offset;
 200         files_struct *fsp = state->fsp;
 201         const DATA_BLOB *hdr = state->smb2req->queue_entry.sendfile_header;
 202         NTSTATUS *pstatus = state->smb2req->queue_entry.sendfile_status;
 203         struct smbXsrv_connection *xconn = state->smb2req->xconn;
 204         ssize_t nread;
 205         ssize_t ret;
 206         int saved_errno;
 207
 208         nread = SMB_VFS_SENDFILE(xconn->transport.sock,
 209                                  fsp,
 210                                  hdr,
 211                                  in_offset,
 212                                  in_length);
 213         DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
 214                 (int)nread,
 215                 fsp_str_dbg(fsp) ));
 216
 217         if (nread == -1) {
 218                 saved_errno = errno;
 219
 220                 /*
 221                  * Returning ENOSYS means no data at all was sent.
 222                    Do this as a normal read. */
 223                 if (errno == ENOSYS) {
 224                         goto normal_read;
 225                 }
 226
 227                 if (errno == ENOTSUP) {
 228                         set_use_sendfile(SNUM(fsp->conn), false);
 229                         DBG_WARNING("Disabling sendfile use as sendfile is "
 230                                     "not supported by the system\n");
 231                         goto normal_read;
 232                 }
 233
 234                 if (errno == EINTR) {
 235                         /*
 236                          * Special hack for broken Linux with no working sendfile. If we
 237                          * return EINTR we sent the header but not the rest of the data.
 238                          * Fake this up by doing read/write calls.
 239                          */
 240                         set_use_sendfile(SNUM(fsp->conn), false);
 241                         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 242                         if (nread == -1) {
 243                                 saved_errno = errno;
 244                                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 245                                          "failed for file %s (%s) for client %s. "
 246                                          "Terminating\n",
 247                                          fsp_str_dbg(fsp), strerror(saved_errno),
 248                                          smbXsrv_connection_dbg(xconn)));
 249                                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 250                                 return 0;
 251                         }
 252                         goto out;
 253                 }
 254
 255                 DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
 256                          "%s (%s) for client %s. Terminating\n",
 257                          fsp_str_dbg(fsp), strerror(saved_errno),
 258                          smbXsrv_connection_dbg(xconn)));
 259                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 260                 return 0;
 261         } else if (nread == 0) {
 262                 /*
 263                  * Some sendfile implementations return 0 to indicate
 264                  * that there was a short read, but nothing was
 265                  * actually written to the socket.  In this case,
 266                  * fallback to the normal read path so the header gets
 267                  * the correct byte count.
 268                  */
 269                 DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
 270                         "falling back to the normal read: %s\n",
 271                         fsp_str_dbg(fsp)));
 272                 goto normal_read;
 273         }
 274
 275         /*
 276          * We got a short read
 277          */
 278         goto out;
 279
 280 normal_read:
 281         /* Send out the header. */
 282         ret = write_data(xconn->transport.sock,
 283                          (const char *)hdr->data, hdr->length);
 284         if (ret != hdr->length) {
 285                 saved_errno = errno;
 286                 DEBUG(0,("smb2_sendfile_send_data: write_data failed for file "
 287                          "%s (%s) for client %s. Terminating\n",
 288                          fsp_str_dbg(fsp), strerror(saved_errno),
 289                          smbXsrv_connection_dbg(xconn)));
 290                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 291                 return 0;
 292         }
 293         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 294         if (nread == -1) {
 295                 saved_errno = errno;
 296                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 297                          "failed for file %s (%s) for client %s. "
 298                          "Terminating\n",
 299                          fsp_str_dbg(fsp), strerror(saved_errno),
 300                          smbXsrv_connection_dbg(xconn)));
 301                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 302                 return 0;
 303         }
 304
 305   out:
 306
 307         if (nread < in_length) {
 308                 ret = sendfile_short_send(xconn, fsp, nread,
 309                                           hdr->length, in_length);
 310                 if (ret == -1) {
 311                         saved_errno = errno;
 312                         DEBUG(0,("%s: sendfile_short_send "
 313                                  "failed for file %s (%s) for client %s. "
 314                                  "Terminating\n",
 315                                  __func__,
 316                                  fsp_str_dbg(fsp), strerror(saved_errno),
 317                                  smbXsrv_connection_dbg(xconn)));
 318                         *pstatus = map_nt_error_from_unix_common(saved_errno);
 319                         return 0;
 320                 }
 321         }
 322
 323         init_strict_lock_struct(fsp,
 324                                 fsp->op->global->open_persistent_id,
 325                                 in_offset,
 326                                 in_length,
 327                                 READ_LOCK,
 328                                 &lock);
 329
 330         *pstatus = NT_STATUS_OK;
 331         return 0;
 332 }
 333
 334 static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
 335                                         struct smbd_smb2_read_state *state)
 336 {
 337         files_struct *fsp = state->fsp;
 338
 339         /*
 340          * We cannot use sendfile if...
 341          * We were not configured to do so OR
 342          * Signing is active OR
 343          * This is a compound SMB2 operation OR
 344          * fsp is a STREAM file OR
 345          * We're using a write cache OR
 346          * It's not a regular file OR
 347          * Requested offset is greater than file size OR
 348          * there's not enough data in the file.
 349          * Phew :-). Luckily this means most
 350          * reads on most normal files. JRA.
 351         */
 352
 353         if (!lp__use_sendfile(SNUM(fsp->conn)) ||
 354             smb2req->do_signing ||
 355             smb2req->do_encryption ||
 356             smbd_smb2_is_compound(smb2req) ||
 357             (fsp->base_fsp != NULL) ||
 358             (fsp->wcp != NULL) ||
 359             (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
 360             (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
 361             (fsp->fsp_name->st.st_ex_size < state->in_offset + state->in_length))
 362         {
 363                 return NT_STATUS_RETRY;
 364         }
 365
 366         /* We've already checked there's this amount of data
 367            to read. */
 368         state->out_data.length = state->in_length;
 369         state->out_remaining = 0;
 370
 371         state->out_headers = data_blob_const(state->_out_hdr_buf,
 372                                              sizeof(state->_out_hdr_buf));
 373         return NT_STATUS_OK;
 374 }
 375
 376 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 377
 378 /*******************************************************************
 379  Common read complete processing function for both synchronous and
 380  asynchronous reads.
 381 *******************************************************************/
 382
 383 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 384 {
 385         struct smbd_smb2_read_state *state = tevent_req_data(req,
 386                                         struct smbd_smb2_read_state);
 387         files_struct *fsp = state->fsp;
 388
 389         if (nread < 0) {
 390                 NTSTATUS status = map_nt_error_from_unix(err);
 391
 392                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 393                         "Error = %s (NTSTATUS %s)\n",
 394                         fsp_str_dbg(fsp),
 395                         (int)nread,
 396                         strerror(err),
 397                         nt_errstr(status)));
 398
 399                 return status;
 400         }
 401         if (nread == 0 && state->in_length != 0) {
 402                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 403                         fsp_str_dbg(fsp)));
 404                 return NT_STATUS_END_OF_FILE;
 405         }
 406
 407         if (nread < state->in_minimum) {
 408                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 409                         "minimum requested %u. Returning end of file\n",
 410                         fsp_str_dbg(fsp),
 411                         (int)nread,
 412                         (unsigned int)state->in_minimum));
 413                 return NT_STATUS_END_OF_FILE;
 414         }
 415
 416         DEBUG(3,("smbd_smb2_read: %s, file %s, length=%lu offset=%lu read=%lu\n",
 417                 fsp_fnum_dbg(fsp),
 418                 fsp_str_dbg(fsp),
 419                 (unsigned long)state->in_length,
 420                 (unsigned long)state->in_offset,
 421                 (unsigned long)nread));
 422
 423         state->out_data.length = nread;
 424         state->out_remaining = 0;
 425
 426         return NT_STATUS_OK;
 427 }
 428
 429 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 430 {
 431         struct smbd_smb2_read_state *state =
 432                 tevent_req_data(req,
 433                 struct smbd_smb2_read_state);
 434
 435         return cancel_smb2_aio(state->smbreq);
 436 }
 437
 438 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 439                                               struct tevent_context *ev,
 440                                               struct smbd_smb2_request *smb2req,
 441                                               struct files_struct *fsp,
 442                                               uint8_t in_flags,
 443                                               uint32_t in_length,
 444                                               uint64_t in_offset,
 445                                               uint32_t in_minimum,
 446                                               uint32_t in_remaining)
 447 {
 448         NTSTATUS status;
 449         struct tevent_req *req = NULL;
 450         struct smbd_smb2_read_state *state = NULL;
 451         struct smb_request *smbreq = NULL;
 452         connection_struct *conn = smb2req->tcon->compat;
 453         ssize_t nread = -1;
 454         struct lock_struct lock;
 455         int saved_errno;
 456
 457         req = tevent_req_create(mem_ctx, &state,
 458                                 struct smbd_smb2_read_state);
 459         if (req == NULL) {
 460                 return NULL;
 461         }
 462         state->smb2req = smb2req;
 463         state->in_flags = in_flags;
 464         state->in_length = in_length;
 465         state->in_offset = in_offset;
 466         state->in_minimum = in_minimum;
 467         state->out_data = data_blob_null;
 468         state->out_remaining = 0;
 469
 470         DEBUG(10,("smbd_smb2_read: %s - %s\n",
 471                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 472
 473         smbreq = smbd_smb2_fake_smb_request(smb2req);
 474         if (tevent_req_nomem(smbreq, req)) {
 475                 return tevent_req_post(req, ev);
 476         }
 477         state->smbreq = smbreq;
 478
 479         if (fsp->is_directory) {
 480                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 481                 return tevent_req_post(req, ev);
 482         }
 483
 484         state->fsp = fsp;
 485
 486         if (IS_IPC(smbreq->conn)) {
 487                 struct tevent_req *subreq = NULL;
 488
 489                 state->out_data = data_blob_talloc(state, NULL, in_length);
 490                 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 491                         return tevent_req_post(req, ev);
 492                 }
 493
 494                 if (!fsp_is_np(fsp)) {
 495                         tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 496                         return tevent_req_post(req, ev);
 497                 }
 498
 499                 subreq = np_read_send(state, ev,
 500                                       fsp->fake_file_handle,
 501                                       state->out_data.data,
 502                                       state->out_data.length);
 503                 if (tevent_req_nomem(subreq, req)) {
 504                         return tevent_req_post(req, ev);
 505                 }
 506                 tevent_req_set_callback(subreq,
 507                                         smbd_smb2_read_pipe_done,
 508                                         req);
 509                 return req;
 510         }
 511
 512         if (!CHECK_READ_SMB2(fsp)) {
 513                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 514                 return tevent_req_post(req, ev);
 515         }
 516
 517         status = schedule_smb2_aio_read(fsp->conn,
 518                                 smbreq,
 519                                 fsp,
 520                                 state,
 521                                 &state->out_data,
 522                                 (off_t)in_offset,
 523                                 (size_t)in_length);
 524
 525         if (NT_STATUS_IS_OK(status)) {
 526                 /*
 527                  * Doing an async read, allow this
 528                  * request to be canceled
 529                  */
 530                 tevent_req_set_cancel_fn(req, smbd_smb2_read_cancel);
 531                 return req;
 532         }
 533
 534         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 535                 /* Real error in setting up aio. Fail. */
 536                 tevent_req_nterror(req, status);
 537                 return tevent_req_post(req, ev);
 538         }
 539
 540         /* Fallback to synchronous. */
 541
 542         init_strict_lock_struct(fsp,
 543                                 fsp->op->global->open_persistent_id,
 544                                 in_offset,
 545                                 in_length,
 546                                 READ_LOCK,
 547                                 &lock);
 548
 549         if (!SMB_VFS_STRICT_LOCK_CHECK(conn, fsp, &lock)) {
 550                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 551                 return tevent_req_post(req, ev);
 552         }
 553
 554         /* Try sendfile in preference. */
 555         status = schedule_smb2_sendfile_read(smb2req, state);
 556         if (NT_STATUS_IS_OK(status)) {
 557                 tevent_req_done(req);
 558                 return tevent_req_post(req, ev);
 559         } else {
 560                 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 561                         tevent_req_nterror(req, status);
 562                         return tevent_req_post(req, ev);
 563                 }
 564         }
 565
 566         /* Ok, read into memory. Allocate the out buffer. */
 567         state->out_data = data_blob_talloc(state, NULL, in_length);
 568         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 569                 return tevent_req_post(req, ev);
 570         }
 571
 572         nread = read_file(fsp,
 573                           (char *)state->out_data.data,
 574                           in_offset,
 575                           in_length);
 576
 577         saved_errno = errno;
 578
 579         DEBUG(10,("smbd_smb2_read: file %s, %s, offset=%llu "
 580                 "len=%llu returned %lld\n",
 581                 fsp_str_dbg(fsp),
 582                 fsp_fnum_dbg(fsp),
 583                 (unsigned long long)in_offset,
 584                 (unsigned long long)in_length,
 585                 (long long)nread));
 586
 587         status = smb2_read_complete(req, nread, saved_errno);
 588         if (!NT_STATUS_IS_OK(status)) {
 589                 tevent_req_nterror(req, status);
 590         } else {
 591                 /* Success. */
 592                 tevent_req_done(req);
 593         }
 594         return tevent_req_post(req, ev);
 595 }
 596
 597 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 598 {
 599         struct tevent_req *req = tevent_req_callback_data(subreq,
 600                                  struct tevent_req);
 601         struct smbd_smb2_read_state *state = tevent_req_data(req,
 602                                              struct smbd_smb2_read_state);
 603         NTSTATUS status;
 604         ssize_t nread = -1;
 605         bool is_data_outstanding;
 606
 607         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 608         TALLOC_FREE(subreq);
 609         if (!NT_STATUS_IS_OK(status)) {
 610                 NTSTATUS old = status;
 611                 status = nt_status_np_pipe(old);
 612                 tevent_req_nterror(req, status);
 613                 return;
 614         }
 615
 616         if (nread == 0 && state->out_data.length != 0) {
 617                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 618                 return;
 619         }
 620
 621         state->out_data.length = nread;
 622         state->out_remaining = 0;
 623
 624         /*
 625          * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
 626          * handle it in SMB1 pipe_read_andx_done().
 627          */
 628
 629         tevent_req_done(req);
 630 }
 631
 632 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 633                                     TALLOC_CTX *mem_ctx,
 634                                     DATA_BLOB *out_data,
 635                                     uint32_t *out_remaining)
 636 {
 637         NTSTATUS status;
 638         struct smbd_smb2_read_state *state = tevent_req_data(req,
 639                                              struct smbd_smb2_read_state);
 640
 641         if (tevent_req_is_nterror(req, &status)) {
 642                 tevent_req_received(req);
 643                 return status;
 644         }
 645
 646         *out_data = state->out_data;
 647         talloc_steal(mem_ctx, out_data->data);
 648         *out_remaining = state->out_remaining;
 649
 650         if (state->out_headers.length > 0) {
 651                 talloc_steal(mem_ctx, state);
 652                 talloc_set_destructor(state, smb2_smb2_read_state_deny_destructor);
 653                 tevent_req_received(req);
 654                 state->smb2req->queue_entry.sendfile_header = &state->out_headers;
 655                 talloc_set_destructor(state, smb2_sendfile_send_data);
 656         } else {
 657                 tevent_req_received(req);
 658         }
 659
 660         return NT_STATUS_OK;
 661 }