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
  30 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
  31                                               struct tevent_context *ev,
  32                                               struct smbd_smb2_request *smb2req,
  33                                               struct files_struct *in_fsp,
  34                                               uint32_t in_length,
  35                                               uint64_t in_offset,
  36                                               uint32_t in_minimum,
  37                                               uint32_t in_remaining);
  38 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
  39                                     TALLOC_CTX *mem_ctx,
  40                                     DATA_BLOB *out_data,
  41                                     uint32_t *out_remaining);
  42
  43 static void smbd_smb2_request_read_done(struct tevent_req *subreq);
  44 NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
  45 {
  46         struct smbXsrv_connection *xconn = req->xconn;
  47         NTSTATUS status;
  48         const uint8_t *inbody;
  49         uint32_t in_length;
  50         uint64_t in_offset;
  51         uint64_t in_file_id_persistent;
  52         uint64_t in_file_id_volatile;
  53         struct files_struct *in_fsp;
  54         uint32_t in_minimum_count;
  55         uint32_t in_remaining_bytes;
  56         struct tevent_req *subreq;
  57
  58         status = smbd_smb2_request_verify_sizes(req, 0x31);
  59         if (!NT_STATUS_IS_OK(status)) {
  60                 return smbd_smb2_request_error(req, status);
  61         }
  62         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  63
  64         in_length               = IVAL(inbody, 0x04);
  65         in_offset               = BVAL(inbody, 0x08);
  66         in_file_id_persistent   = BVAL(inbody, 0x10);
  67         in_file_id_volatile     = BVAL(inbody, 0x18);
  68         in_minimum_count        = IVAL(inbody, 0x20);
  69         in_remaining_bytes      = IVAL(inbody, 0x28);
  70
  71         /* check the max read size */
  72         if (in_length > xconn->smb2.server.max_read) {
  73                 DEBUG(2,("smbd_smb2_request_process_read: "
  74                          "client ignored max read: %s: 0x%08X: 0x%08X\n",
  75                         __location__, in_length, xconn->smb2.server.max_read));
  76                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  77         }
  78
  79         status = smbd_smb2_request_verify_creditcharge(req, in_length);
  80         if (!NT_STATUS_IS_OK(status)) {
  81                 return smbd_smb2_request_error(req, status);
  82         }
  83
  84         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  85         if (in_fsp == NULL) {
  86                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  87         }
  88
  89         subreq = smbd_smb2_read_send(req, req->sconn->ev_ctx,
  90                                      req, in_fsp,
  91                                      in_length,
  92                                      in_offset,
  93                                      in_minimum_count,
  94                                      in_remaining_bytes);
  95         if (subreq == NULL) {
  96                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
  97         }
  98         tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
  99
 100         return smbd_smb2_request_pending_queue(req, subreq, 500);
 101 }
 102
 103 static void smbd_smb2_request_read_done(struct tevent_req *subreq)
 104 {
 105         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 106                                         struct smbd_smb2_request);
 107         DATA_BLOB outbody;
 108         DATA_BLOB outdyn;
 109         uint8_t out_data_offset;
 110         DATA_BLOB out_data_buffer = data_blob_null;
 111         uint32_t out_data_remaining = 0;
 112         NTSTATUS status;
 113         NTSTATUS error; /* transport error */
 114
 115         status = smbd_smb2_read_recv(subreq,
 116                                      req,
 117                                      &out_data_buffer,
 118                                      &out_data_remaining);
 119         TALLOC_FREE(subreq);
 120         if (!NT_STATUS_IS_OK(status)) {
 121                 error = smbd_smb2_request_error(req, status);
 122                 if (!NT_STATUS_IS_OK(error)) {
 123                         smbd_server_connection_terminate(req->xconn,
 124                                                          nt_errstr(error));
 125                         return;
 126                 }
 127                 return;
 128         }
 129
 130         out_data_offset = SMB2_HDR_BODY + 0x10;
 131
 132         outbody = smbd_smb2_generate_outbody(req, 0x10);
 133         if (outbody.data == NULL) {
 134                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 135                 if (!NT_STATUS_IS_OK(error)) {
 136                         smbd_server_connection_terminate(req->xconn,
 137                                                          nt_errstr(error));
 138                         return;
 139                 }
 140                 return;
 141         }
 142
 143         SSVAL(outbody.data, 0x00, 0x10 + 1);    /* struct size */
 144         SCVAL(outbody.data, 0x02,
 145               out_data_offset);                 /* data offset */
 146         SCVAL(outbody.data, 0x03, 0);           /* reserved */
 147         SIVAL(outbody.data, 0x04,
 148               out_data_buffer.length);          /* data length */
 149         SIVAL(outbody.data, 0x08,
 150               out_data_remaining);              /* data remaining */
 151         SIVAL(outbody.data, 0x0C, 0);           /* reserved */
 152
 153         outdyn = out_data_buffer;
 154
 155         error = smbd_smb2_request_done(req, outbody, &outdyn);
 156         if (!NT_STATUS_IS_OK(error)) {
 157                 smbd_server_connection_terminate(req->xconn,
 158                                                  nt_errstr(error));
 159                 return;
 160         }
 161 }
 162
 163 struct smbd_smb2_read_state {
 164         struct smbd_smb2_request *smb2req;
 165         struct smb_request *smbreq;
 166         files_struct *fsp;
 167         uint32_t in_length;
 168         uint64_t in_offset;
 169         uint32_t in_minimum;
 170         DATA_BLOB out_headers;
 171         uint8_t _out_hdr_buf[NBT_HDR_SIZE + SMB2_HDR_BODY + 0x10];
 172         DATA_BLOB out_data;
 173         uint32_t out_remaining;
 174 };
 175
 176 static int smb2_smb2_read_state_deny_destructor(struct smbd_smb2_read_state *state)
 177 {
 178         return -1;
 179 }
 180
 181 /* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
 182 static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
 183 {
 184         struct lock_struct lock;
 185         uint32_t in_length = state->in_length;
 186         uint64_t in_offset = state->in_offset;
 187         files_struct *fsp = state->fsp;
 188         const DATA_BLOB *hdr = state->smb2req->queue_entry.sendfile_header;
 189         struct smbXsrv_connection *xconn = state->smb2req->xconn;
 190         ssize_t nread;
 191         ssize_t ret;
 192         int saved_errno;
 193
 194         nread = SMB_VFS_SENDFILE(xconn->transport.sock,
 195                                  fsp,
 196                                  hdr,
 197                                  in_offset,
 198                                  in_length);
 199         DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
 200                 (int)nread,
 201                 fsp_str_dbg(fsp) ));
 202
 203         if (nread == -1) {
 204                 saved_errno = errno;
 205
 206                 /*
 207                  * Returning ENOSYS means no data at all was sent.
 208                    Do this as a normal read. */
 209                 if (errno == ENOSYS) {
 210                         goto normal_read;
 211                 }
 212
 213                 if (errno == EINTR) {
 214                         /*
 215                          * Special hack for broken Linux with no working sendfile. If we
 216                          * return EINTR we sent the header but not the rest of the data.
 217                          * Fake this up by doing read/write calls.
 218                          */
 219                         set_use_sendfile(SNUM(fsp->conn), false);
 220                         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 221                         if (nread == -1) {
 222                                 saved_errno = errno;
 223                                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 224                                          "failed for file %s (%s) for client %s. "
 225                                          "Terminating\n",
 226                                          fsp_str_dbg(fsp), strerror(saved_errno),
 227                                          smbXsrv_connection_dbg(xconn)));
 228                                 exit_server_cleanly("smb2_sendfile_send_data: "
 229                                         "fake_sendfile failed");
 230                         }
 231                         goto out;
 232                 }
 233
 234                 DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
 235                          "%s (%s) for client %s. Terminating\n",
 236                          fsp_str_dbg(fsp), strerror(saved_errno),
 237                          smbXsrv_connection_dbg(xconn)));
 238                 exit_server_cleanly("smb2_sendfile_send_data: sendfile failed");
 239         } else if (nread == 0) {
 240                 /*
 241                  * Some sendfile implementations return 0 to indicate
 242                  * that there was a short read, but nothing was
 243                  * actually written to the socket.  In this case,
 244                  * fallback to the normal read path so the header gets
 245                  * the correct byte count.
 246                  */
 247                 DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
 248                         "falling back to the normal read: %s\n",
 249                         fsp_str_dbg(fsp)));
 250                 goto normal_read;
 251         }
 252
 253         /*
 254          * We got a short read
 255          */
 256         goto out;
 257
 258 normal_read:
 259         /* Send out the header. */
 260         ret = write_data(xconn->transport.sock,
 261                          (const char *)hdr->data, hdr->length);
 262         if (ret != hdr->length) {
 263                 saved_errno = errno;
 264                 DEBUG(0,("smb2_sendfile_send_data: write_data failed for file "
 265                          "%s (%s) for client %s. Terminating\n",
 266                          fsp_str_dbg(fsp), strerror(saved_errno),
 267                          smbXsrv_connection_dbg(xconn)));
 268                 exit_server_cleanly("smb2_sendfile_send_data: write_data failed");
 269         }
 270         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 271         if (nread == -1) {
 272                 saved_errno = errno;
 273                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 274                          "failed for file %s (%s) for client %s. "
 275                          "Terminating\n",
 276                          fsp_str_dbg(fsp), strerror(saved_errno),
 277                          smbXsrv_connection_dbg(xconn)));
 278                 exit_server_cleanly("smb2_sendfile_send_data: "
 279                         "fake_sendfile failed");
 280         }
 281
 282   out:
 283
 284         if (nread < in_length) {
 285                 ret = sendfile_short_send(xconn, fsp, nread,
 286                                           hdr->length, in_length);
 287                 if (ret == -1) {
 288                         saved_errno = errno;
 289                         DEBUG(0,("smb2_sendfile_send_data: sendfile_short_send "
 290                                  "failed for file %s (%s) for client %s. "
 291                                  "Terminating\n",
 292                                  fsp_str_dbg(fsp), strerror(saved_errno),
 293                                  smbXsrv_connection_dbg(xconn)));
 294                         exit_server_cleanly("smb2_sendfile_send_data: "
 295                                 "sendfile_short_send failed");
 296                 }
 297         }
 298
 299         init_strict_lock_struct(fsp,
 300                                 fsp->op->global->open_persistent_id,
 301                                 in_offset,
 302                                 in_length,
 303                                 READ_LOCK,
 304                                 &lock);
 305
 306         SMB_VFS_STRICT_UNLOCK(fsp->conn, fsp, &lock);
 307         return 0;
 308 }
 309
 310 static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
 311                                         struct smbd_smb2_read_state *state)
 312 {
 313         files_struct *fsp = state->fsp;
 314
 315         /*
 316          * We cannot use sendfile if...
 317          * We were not configured to do so OR
 318          * Signing is active OR
 319          * This is a compound SMB2 operation OR
 320          * fsp is a STREAM file OR
 321          * We're using a write cache OR
 322          * It's not a regular file OR
 323          * Requested offset is greater than file size OR
 324          * there's not enough data in the file.
 325          * Phew :-). Luckily this means most
 326          * reads on most normal files. JRA.
 327         */
 328
 329         if (!lp__use_sendfile(SNUM(fsp->conn)) ||
 330             smb2req->do_signing ||
 331             smb2req->do_encryption ||
 332             smb2req->in.vector_count >= (2*SMBD_SMB2_NUM_IOV_PER_REQ) ||
 333             (fsp->base_fsp != NULL) ||
 334             (fsp->wcp != NULL) ||
 335             (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
 336             (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
 337             (fsp->fsp_name->st.st_ex_size < state->in_offset + state->in_length))
 338         {
 339                 return NT_STATUS_RETRY;
 340         }
 341
 342         /* We've already checked there's this amount of data
 343            to read. */
 344         state->out_data.length = state->in_length;
 345         state->out_remaining = 0;
 346
 347         state->out_headers = data_blob_const(state->_out_hdr_buf,
 348                                              sizeof(state->_out_hdr_buf));
 349         return NT_STATUS_OK;
 350 }
 351
 352 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 353
 354 /*******************************************************************
 355  Common read complete processing function for both synchronous and
 356  asynchronous reads.
 357 *******************************************************************/
 358
 359 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 360 {
 361         struct smbd_smb2_read_state *state = tevent_req_data(req,
 362                                         struct smbd_smb2_read_state);
 363         files_struct *fsp = state->fsp;
 364
 365         if (nread < 0) {
 366                 NTSTATUS status = map_nt_error_from_unix(err);
 367
 368                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 369                         "Error = %s (NTSTATUS %s)\n",
 370                         fsp_str_dbg(fsp),
 371                         (int)nread,
 372                         strerror(err),
 373                         nt_errstr(status)));
 374
 375                 return status;
 376         }
 377         if (nread == 0 && state->in_length != 0) {
 378                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 379                         fsp_str_dbg(fsp)));
 380                 return NT_STATUS_END_OF_FILE;
 381         }
 382
 383         if (nread < state->in_minimum) {
 384                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 385                         "minimum requested %u. Returning end of file\n",
 386                         fsp_str_dbg(fsp),
 387                         (int)nread,
 388                         (unsigned int)state->in_minimum));
 389                 return NT_STATUS_END_OF_FILE;
 390         }
 391
 392         DEBUG(3,("smbd_smb2_read: %s, file %s, length=%lu offset=%lu read=%lu\n",
 393                 fsp_fnum_dbg(fsp),
 394                 fsp_str_dbg(fsp),
 395                 (unsigned long)state->in_length,
 396                 (unsigned long)state->in_offset,
 397                 (unsigned long)nread));
 398
 399         state->out_data.length = nread;
 400         state->out_remaining = 0;
 401
 402         return NT_STATUS_OK;
 403 }
 404
 405 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 406 {
 407         struct smbd_smb2_read_state *state =
 408                 tevent_req_data(req,
 409                 struct smbd_smb2_read_state);
 410
 411         return cancel_smb2_aio(state->smbreq);
 412 }
 413
 414 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 415                                               struct tevent_context *ev,
 416                                               struct smbd_smb2_request *smb2req,
 417                                               struct files_struct *fsp,
 418                                               uint32_t in_length,
 419                                               uint64_t in_offset,
 420                                               uint32_t in_minimum,
 421                                               uint32_t in_remaining)
 422 {
 423         NTSTATUS status;
 424         struct tevent_req *req = NULL;
 425         struct smbd_smb2_read_state *state = NULL;
 426         struct smb_request *smbreq = NULL;
 427         connection_struct *conn = smb2req->tcon->compat;
 428         ssize_t nread = -1;
 429         struct lock_struct lock;
 430         int saved_errno;
 431
 432         req = tevent_req_create(mem_ctx, &state,
 433                                 struct smbd_smb2_read_state);
 434         if (req == NULL) {
 435                 return NULL;
 436         }
 437         state->smb2req = smb2req;
 438         state->in_length = in_length;
 439         state->in_offset = in_offset;
 440         state->in_minimum = in_minimum;
 441         state->out_data = data_blob_null;
 442         state->out_remaining = 0;
 443
 444         DEBUG(10,("smbd_smb2_read: %s - %s\n",
 445                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 446
 447         smbreq = smbd_smb2_fake_smb_request(smb2req);
 448         if (tevent_req_nomem(smbreq, req)) {
 449                 return tevent_req_post(req, ev);
 450         }
 451         state->smbreq = smbreq;
 452
 453         if (fsp->is_directory) {
 454                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 455                 return tevent_req_post(req, ev);
 456         }
 457
 458         state->fsp = fsp;
 459
 460         if (IS_IPC(smbreq->conn)) {
 461                 struct tevent_req *subreq = NULL;
 462
 463                 state->out_data = data_blob_talloc(state, NULL, in_length);
 464                 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 465                         return tevent_req_post(req, ev);
 466                 }
 467
 468                 if (!fsp_is_np(fsp)) {
 469                         tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 470                         return tevent_req_post(req, ev);
 471                 }
 472
 473                 subreq = np_read_send(state, ev,
 474                                       fsp->fake_file_handle,
 475                                       state->out_data.data,
 476                                       state->out_data.length);
 477                 if (tevent_req_nomem(subreq, req)) {
 478                         return tevent_req_post(req, ev);
 479                 }
 480                 tevent_req_set_callback(subreq,
 481                                         smbd_smb2_read_pipe_done,
 482                                         req);
 483                 return req;
 484         }
 485
 486         if (!CHECK_READ(fsp, smbreq)) {
 487                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 488                 return tevent_req_post(req, ev);
 489         }
 490
 491         status = schedule_smb2_aio_read(fsp->conn,
 492                                 smbreq,
 493                                 fsp,
 494                                 state,
 495                                 &state->out_data,
 496                                 (off_t)in_offset,
 497                                 (size_t)in_length);
 498
 499         if (NT_STATUS_IS_OK(status)) {
 500                 /*
 501                  * Doing an async read, allow this
 502                  * request to be canceled
 503                  */
 504                 tevent_req_set_cancel_fn(req, smbd_smb2_read_cancel);
 505                 return req;
 506         }
 507
 508         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 509                 /* Real error in setting up aio. Fail. */
 510                 tevent_req_nterror(req, status);
 511                 return tevent_req_post(req, ev);
 512         }
 513
 514         /* Fallback to synchronous. */
 515
 516         init_strict_lock_struct(fsp,
 517                                 fsp->op->global->open_persistent_id,
 518                                 in_offset,
 519                                 in_length,
 520                                 READ_LOCK,
 521                                 &lock);
 522
 523         if (!SMB_VFS_STRICT_LOCK(conn, fsp, &lock)) {
 524                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 525                 return tevent_req_post(req, ev);
 526         }
 527
 528         /* Try sendfile in preference. */
 529         status = schedule_smb2_sendfile_read(smb2req, state);
 530         if (NT_STATUS_IS_OK(status)) {
 531                 tevent_req_done(req);
 532                 return tevent_req_post(req, ev);
 533         } else {
 534                 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 535                         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 536                         tevent_req_nterror(req, status);
 537                         return tevent_req_post(req, ev);
 538                 }
 539         }
 540
 541         /* Ok, read into memory. Allocate the out buffer. */
 542         state->out_data = data_blob_talloc(state, NULL, in_length);
 543         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 544                 SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 545                 return tevent_req_post(req, ev);
 546         }
 547
 548         nread = read_file(fsp,
 549                           (char *)state->out_data.data,
 550                           in_offset,
 551                           in_length);
 552
 553         saved_errno = errno;
 554
 555         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 556
 557         DEBUG(10,("smbd_smb2_read: file %s, %s, offset=%llu "
 558                 "len=%llu returned %lld\n",
 559                 fsp_str_dbg(fsp),
 560                 fsp_fnum_dbg(fsp),
 561                 (unsigned long long)in_offset,
 562                 (unsigned long long)in_length,
 563                 (long long)nread));
 564
 565         status = smb2_read_complete(req, nread, saved_errno);
 566         if (!NT_STATUS_IS_OK(status)) {
 567                 tevent_req_nterror(req, status);
 568         } else {
 569                 /* Success. */
 570                 tevent_req_done(req);
 571         }
 572         return tevent_req_post(req, ev);
 573 }
 574
 575 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 576 {
 577         struct tevent_req *req = tevent_req_callback_data(subreq,
 578                                  struct tevent_req);
 579         struct smbd_smb2_read_state *state = tevent_req_data(req,
 580                                              struct smbd_smb2_read_state);
 581         NTSTATUS status;
 582         ssize_t nread = -1;
 583         bool is_data_outstanding;
 584
 585         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 586         TALLOC_FREE(subreq);
 587         if (!NT_STATUS_IS_OK(status)) {
 588                 NTSTATUS old = status;
 589                 status = nt_status_np_pipe(old);
 590                 tevent_req_nterror(req, status);
 591                 return;
 592         }
 593
 594         if (nread == 0 && state->out_data.length != 0) {
 595                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 596                 return;
 597         }
 598
 599         state->out_data.length = nread;
 600         state->out_remaining = 0;
 601
 602         /*
 603          * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
 604          * handle it in SMB1 pipe_read_andx_done().
 605          */
 606
 607         tevent_req_done(req);
 608 }
 609
 610 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 611                                     TALLOC_CTX *mem_ctx,
 612                                     DATA_BLOB *out_data,
 613                                     uint32_t *out_remaining)
 614 {
 615         NTSTATUS status;
 616         struct smbd_smb2_read_state *state = tevent_req_data(req,
 617                                              struct smbd_smb2_read_state);
 618
 619         if (tevent_req_is_nterror(req, &status)) {
 620                 tevent_req_received(req);
 621                 return status;
 622         }
 623
 624         *out_data = state->out_data;
 625         talloc_steal(mem_ctx, out_data->data);
 626         *out_remaining = state->out_remaining;
 627
 628         if (state->out_headers.length > 0) {
 629                 talloc_steal(mem_ctx, state);
 630                 talloc_set_destructor(state, smb2_smb2_read_state_deny_destructor);
 631                 tevent_req_received(req);
 632                 state->smb2req->queue_entry.sendfile_header = &state->out_headers;
 633                 talloc_set_destructor(state, smb2_sendfile_send_data);
 634         } else {
 635                 tevent_req_received(req);
 636         }
 637
 638         return NT_STATUS_OK;
 639 }