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/sys_rw_data.h"
  30
  31 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
  32                                               struct tevent_context *ev,
  33                                               struct smbd_smb2_request *smb2req,
  34                                               struct files_struct *in_fsp,
  35                                               uint8_t in_flags,
  36                                               uint32_t in_length,
  37                                               uint64_t in_offset,
  38                                               uint32_t in_minimum,
  39                                               uint32_t in_remaining);
  40 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
  41                                     TALLOC_CTX *mem_ctx,
  42                                     DATA_BLOB *out_data,
  43                                     uint32_t *out_remaining);
  44
  45 static void smbd_smb2_request_read_done(struct tevent_req *subreq);
  46 NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
  47 {
  48         struct smbXsrv_connection *xconn = req->xconn;
  49         NTSTATUS status;
  50         const uint8_t *inbody;
  51         uint8_t in_flags;
  52         uint32_t in_length;
  53         uint64_t in_offset;
  54         uint64_t in_file_id_persistent;
  55         uint64_t in_file_id_volatile;
  56         struct files_struct *in_fsp;
  57         uint32_t in_minimum_count;
  58         uint32_t in_remaining_bytes;
  59         struct tevent_req *subreq;
  60
  61         status = smbd_smb2_request_verify_sizes(req, 0x31);
  62         if (!NT_STATUS_IS_OK(status)) {
  63                 return smbd_smb2_request_error(req, status);
  64         }
  65         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  66
  67         if (xconn->protocol >= PROTOCOL_SMB3_02) {
  68                 in_flags                = CVAL(inbody, 0x03);
  69         } else {
  70                 in_flags                = 0;
  71         }
  72         in_length               = IVAL(inbody, 0x04);
  73         in_offset               = BVAL(inbody, 0x08);
  74         in_file_id_persistent   = BVAL(inbody, 0x10);
  75         in_file_id_volatile     = BVAL(inbody, 0x18);
  76         in_minimum_count        = IVAL(inbody, 0x20);
  77         in_remaining_bytes      = IVAL(inbody, 0x28);
  78
  79         /* check the max read size */
  80         if (in_length > xconn->smb2.server.max_read) {
  81                 DEBUG(2,("smbd_smb2_request_process_read: "
  82                          "client ignored max read: %s: 0x%08X: 0x%08X\n",
  83                         __location__, in_length, xconn->smb2.server.max_read));
  84                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  85         }
  86
  87         status = smbd_smb2_request_verify_creditcharge(req, in_length);
  88         if (!NT_STATUS_IS_OK(status)) {
  89                 return smbd_smb2_request_error(req, status);
  90         }
  91
  92         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  93         if (in_fsp == NULL) {
  94                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  95         }
  96
  97         subreq = smbd_smb2_read_send(req, req->sconn->ev_ctx,
  98                                      req, in_fsp,
  99                                      in_flags,
 100                                      in_length,
 101                                      in_offset,
 102                                      in_minimum_count,
 103                                      in_remaining_bytes);
 104         if (subreq == NULL) {
 105                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 106         }
 107         tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
 108
 109         return smbd_smb2_request_pending_queue(req, subreq, 500);
 110 }
 111
 112 static void smbd_smb2_request_read_done(struct tevent_req *subreq)
 113 {
 114         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 115                                         struct smbd_smb2_request);
 116         DATA_BLOB outbody;
 117         DATA_BLOB outdyn;
 118         uint8_t out_data_offset;
 119         DATA_BLOB out_data_buffer = data_blob_null;
 120         uint32_t out_data_remaining = 0;
 121         NTSTATUS status;
 122         NTSTATUS error; /* transport error */
 123
 124         status = smbd_smb2_read_recv(subreq,
 125                                      req,
 126                                      &out_data_buffer,
 127                                      &out_data_remaining);
 128         TALLOC_FREE(subreq);
 129         if (!NT_STATUS_IS_OK(status)) {
 130                 error = smbd_smb2_request_error(req, status);
 131                 if (!NT_STATUS_IS_OK(error)) {
 132                         smbd_server_connection_terminate(req->xconn,
 133                                                          nt_errstr(error));
 134                         return;
 135                 }
 136                 return;
 137         }
 138
 139         out_data_offset = SMB2_HDR_BODY + 0x10;
 140
 141         outbody = smbd_smb2_generate_outbody(req, 0x10);
 142         if (outbody.data == NULL) {
 143                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 144                 if (!NT_STATUS_IS_OK(error)) {
 145                         smbd_server_connection_terminate(req->xconn,
 146                                                          nt_errstr(error));
 147                         return;
 148                 }
 149                 return;
 150         }
 151
 152         SSVAL(outbody.data, 0x00, 0x10 + 1);    /* struct size */
 153         SCVAL(outbody.data, 0x02,
 154               out_data_offset);                 /* data offset */
 155         SCVAL(outbody.data, 0x03, 0);           /* reserved */
 156         SIVAL(outbody.data, 0x04,
 157               out_data_buffer.length);          /* data length */
 158         SIVAL(outbody.data, 0x08,
 159               out_data_remaining);              /* data remaining */
 160         SIVAL(outbody.data, 0x0C, 0);           /* reserved */
 161
 162         outdyn = out_data_buffer;
 163
 164         error = smbd_smb2_request_done(req, outbody, &outdyn);
 165         if (!NT_STATUS_IS_OK(error)) {
 166                 smbd_server_connection_terminate(req->xconn,
 167                                                  nt_errstr(error));
 168                 return;
 169         }
 170 }
 171
 172 struct smbd_smb2_read_state {
 173         struct smbd_smb2_request *smb2req;
 174         struct smb_request *smbreq;
 175         files_struct *fsp;
 176         uint8_t in_flags;
 177         uint32_t in_length;
 178         uint64_t in_offset;
 179         uint32_t in_minimum;
 180         DATA_BLOB out_headers;
 181         uint8_t _out_hdr_buf[NBT_HDR_SIZE + SMB2_HDR_BODY + 0x10];
 182         DATA_BLOB out_data;
 183         uint32_t out_remaining;
 184 };
 185
 186 static int smb2_smb2_read_state_deny_destructor(struct smbd_smb2_read_state *state)
 187 {
 188         return -1;
 189 }
 190
 191 /* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
 192 static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
 193 {
 194         struct lock_struct lock;
 195         uint32_t in_length = state->in_length;
 196         uint64_t in_offset = state->in_offset;
 197         files_struct *fsp = state->fsp;
 198         const DATA_BLOB *hdr = state->smb2req->queue_entry.sendfile_header;
 199         NTSTATUS *pstatus = state->smb2req->queue_entry.sendfile_status;
 200         struct smbXsrv_connection *xconn = state->smb2req->xconn;
 201         ssize_t nread;
 202         ssize_t ret;
 203         int saved_errno;
 204
 205         nread = SMB_VFS_SENDFILE(xconn->transport.sock,
 206                                  fsp,
 207                                  hdr,
 208                                  in_offset,
 209                                  in_length);
 210         DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
 211                 (int)nread,
 212                 fsp_str_dbg(fsp) ));
 213
 214         if (nread == -1) {
 215                 saved_errno = errno;
 216
 217                 /*
 218                  * Returning ENOSYS means no data at all was sent.
 219                    Do this as a normal read. */
 220                 if (errno == ENOSYS) {
 221                         goto normal_read;
 222                 }
 223
 224                 if (errno == EINTR) {
 225                         /*
 226                          * Special hack for broken Linux with no working sendfile. If we
 227                          * return EINTR we sent the header but not the rest of the data.
 228                          * Fake this up by doing read/write calls.
 229                          */
 230                         set_use_sendfile(SNUM(fsp->conn), false);
 231                         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 232                         if (nread == -1) {
 233                                 saved_errno = errno;
 234                                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 235                                          "failed for file %s (%s) for client %s. "
 236                                          "Terminating\n",
 237                                          fsp_str_dbg(fsp), strerror(saved_errno),
 238                                          smbXsrv_connection_dbg(xconn)));
 239                                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 240                                 return 0;
 241                         }
 242                         goto out;
 243                 }
 244
 245                 DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
 246                          "%s (%s) for client %s. 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         } else if (nread == 0) {
 252                 /*
 253                  * Some sendfile implementations return 0 to indicate
 254                  * that there was a short read, but nothing was
 255                  * actually written to the socket.  In this case,
 256                  * fallback to the normal read path so the header gets
 257                  * the correct byte count.
 258                  */
 259                 DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
 260                         "falling back to the normal read: %s\n",
 261                         fsp_str_dbg(fsp)));
 262                 goto normal_read;
 263         }
 264
 265         /*
 266          * We got a short read
 267          */
 268         goto out;
 269
 270 normal_read:
 271         /* Send out the header. */
 272         ret = write_data(xconn->transport.sock,
 273                          (const char *)hdr->data, hdr->length);
 274         if (ret != hdr->length) {
 275                 saved_errno = errno;
 276                 DEBUG(0,("smb2_sendfile_send_data: write_data failed for file "
 277                          "%s (%s) for client %s. Terminating\n",
 278                          fsp_str_dbg(fsp), strerror(saved_errno),
 279                          smbXsrv_connection_dbg(xconn)));
 280                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 281                 return 0;
 282         }
 283         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 284         if (nread == -1) {
 285                 saved_errno = errno;
 286                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 287                          "failed for file %s (%s) for client %s. "
 288                          "Terminating\n",
 289                          fsp_str_dbg(fsp), strerror(saved_errno),
 290                          smbXsrv_connection_dbg(xconn)));
 291                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 292                 return 0;
 293         }
 294
 295   out:
 296
 297         if (nread < in_length) {
 298                 ret = sendfile_short_send(xconn, fsp, nread,
 299                                           hdr->length, in_length);
 300                 if (ret == -1) {
 301                         saved_errno = errno;
 302                         DEBUG(0,("%s: sendfile_short_send "
 303                                  "failed for file %s (%s) for client %s. "
 304                                  "Terminating\n",
 305                                  __func__,
 306                                  fsp_str_dbg(fsp), strerror(saved_errno),
 307                                  smbXsrv_connection_dbg(xconn)));
 308                         *pstatus = map_nt_error_from_unix_common(saved_errno);
 309                         return 0;
 310                 }
 311         }
 312
 313         init_strict_lock_struct(fsp,
 314                                 fsp->op->global->open_persistent_id,
 315                                 in_offset,
 316                                 in_length,
 317                                 READ_LOCK,
 318                                 &lock);
 319
 320         SMB_VFS_STRICT_UNLOCK(fsp->conn, fsp, &lock);
 321
 322         *pstatus = NT_STATUS_OK;
 323         return 0;
 324 }
 325
 326 static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
 327                                         struct smbd_smb2_read_state *state)
 328 {
 329         files_struct *fsp = state->fsp;
 330
 331         /*
 332          * We cannot use sendfile if...
 333          * We were not configured to do so OR
 334          * Signing is active OR
 335          * This is a compound SMB2 operation OR
 336          * fsp is a STREAM file OR
 337          * We're using a write cache OR
 338          * It's not a regular file OR
 339          * Requested offset is greater than file size OR
 340          * there's not enough data in the file.
 341          * Phew :-). Luckily this means most
 342          * reads on most normal files. JRA.
 343         */
 344
 345         if (!lp__use_sendfile(SNUM(fsp->conn)) ||
 346             smb2req->do_signing ||
 347             smb2req->do_encryption ||
 348             smb2req->in.vector_count >= (2*SMBD_SMB2_NUM_IOV_PER_REQ) ||
 349             (fsp->base_fsp != NULL) ||
 350             (fsp->wcp != NULL) ||
 351             (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
 352             (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
 353             (fsp->fsp_name->st.st_ex_size < state->in_offset + state->in_length))
 354         {
 355                 return NT_STATUS_RETRY;
 356         }
 357
 358         /* We've already checked there's this amount of data
 359            to read. */
 360         state->out_data.length = state->in_length;
 361         state->out_remaining = 0;
 362
 363         state->out_headers = data_blob_const(state->_out_hdr_buf,
 364                                              sizeof(state->_out_hdr_buf));
 365         return NT_STATUS_OK;
 366 }
 367
 368 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 369
 370 /*******************************************************************
 371  Common read complete processing function for both synchronous and
 372  asynchronous reads.
 373 *******************************************************************/
 374
 375 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 376 {
 377         struct smbd_smb2_read_state *state = tevent_req_data(req,
 378                                         struct smbd_smb2_read_state);
 379         files_struct *fsp = state->fsp;
 380
 381         if (nread < 0) {
 382                 NTSTATUS status = map_nt_error_from_unix(err);
 383
 384                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 385                         "Error = %s (NTSTATUS %s)\n",
 386                         fsp_str_dbg(fsp),
 387                         (int)nread,
 388                         strerror(err),
 389                         nt_errstr(status)));
 390
 391                 return status;
 392         }
 393         if (nread == 0 && state->in_length != 0) {
 394                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 395                         fsp_str_dbg(fsp)));
 396                 return NT_STATUS_END_OF_FILE;
 397         }
 398
 399         if (nread < state->in_minimum) {
 400                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 401                         "minimum requested %u. Returning end of file\n",
 402                         fsp_str_dbg(fsp),
 403                         (int)nread,
 404                         (unsigned int)state->in_minimum));
 405                 return NT_STATUS_END_OF_FILE;
 406         }
 407
 408         DEBUG(3,("smbd_smb2_read: %s, file %s, length=%lu offset=%lu read=%lu\n",
 409                 fsp_fnum_dbg(fsp),
 410                 fsp_str_dbg(fsp),
 411                 (unsigned long)state->in_length,
 412                 (unsigned long)state->in_offset,
 413                 (unsigned long)nread));
 414
 415         state->out_data.length = nread;
 416         state->out_remaining = 0;
 417
 418         return NT_STATUS_OK;
 419 }
 420
 421 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 422 {
 423         struct smbd_smb2_read_state *state =
 424                 tevent_req_data(req,
 425                 struct smbd_smb2_read_state);
 426
 427         return cancel_smb2_aio(state->smbreq);
 428 }
 429
 430 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 431                                               struct tevent_context *ev,
 432                                               struct smbd_smb2_request *smb2req,
 433                                               struct files_struct *fsp,
 434                                               uint8_t in_flags,
 435                                               uint32_t in_length,
 436                                               uint64_t in_offset,
 437                                               uint32_t in_minimum,
 438                                               uint32_t in_remaining)
 439 {
 440         NTSTATUS status;
 441         struct tevent_req *req = NULL;
 442         struct smbd_smb2_read_state *state = NULL;
 443         struct smb_request *smbreq = NULL;
 444         connection_struct *conn = smb2req->tcon->compat;
 445         ssize_t nread = -1;
 446         struct lock_struct lock;
 447         int saved_errno;
 448
 449         req = tevent_req_create(mem_ctx, &state,
 450                                 struct smbd_smb2_read_state);
 451         if (req == NULL) {
 452                 return NULL;
 453         }
 454         state->smb2req = smb2req;
 455         state->in_flags = in_flags;
 456         state->in_length = in_length;
 457         state->in_offset = in_offset;
 458         state->in_minimum = in_minimum;
 459         state->out_data = data_blob_null;
 460         state->out_remaining = 0;
 461
 462         DEBUG(10,("smbd_smb2_read: %s - %s\n",
 463                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 464
 465         smbreq = smbd_smb2_fake_smb_request(smb2req);
 466         if (tevent_req_nomem(smbreq, req)) {
 467                 return tevent_req_post(req, ev);
 468         }
 469         state->smbreq = smbreq;
 470
 471         if (fsp->is_directory) {
 472                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 473                 return tevent_req_post(req, ev);
 474         }
 475
 476         state->fsp = fsp;
 477
 478         if (IS_IPC(smbreq->conn)) {
 479                 struct tevent_req *subreq = NULL;
 480
 481                 state->out_data = data_blob_talloc(state, NULL, in_length);
 482                 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 483                         return tevent_req_post(req, ev);
 484                 }
 485
 486                 if (!fsp_is_np(fsp)) {
 487                         tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 488                         return tevent_req_post(req, ev);
 489                 }
 490
 491                 subreq = np_read_send(state, ev,
 492                                       fsp->fake_file_handle,
 493                                       state->out_data.data,
 494                                       state->out_data.length);
 495                 if (tevent_req_nomem(subreq, req)) {
 496                         return tevent_req_post(req, ev);
 497                 }
 498                 tevent_req_set_callback(subreq,
 499                                         smbd_smb2_read_pipe_done,
 500                                         req);
 501                 return req;
 502         }
 503
 504         if (!CHECK_READ(fsp, smbreq)) {
 505                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 506                 return tevent_req_post(req, ev);
 507         }
 508
 509         status = schedule_smb2_aio_read(fsp->conn,
 510                                 smbreq,
 511                                 fsp,
 512                                 state,
 513                                 &state->out_data,
 514                                 (off_t)in_offset,
 515                                 (size_t)in_length);
 516
 517         if (NT_STATUS_IS_OK(status)) {
 518                 /*
 519                  * Doing an async read, allow this
 520                  * request to be canceled
 521                  */
 522                 tevent_req_set_cancel_fn(req, smbd_smb2_read_cancel);
 523                 return req;
 524         }
 525
 526         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 527                 /* Real error in setting up aio. Fail. */
 528                 tevent_req_nterror(req, status);
 529                 return tevent_req_post(req, ev);
 530         }
 531
 532         /* Fallback to synchronous. */
 533
 534         init_strict_lock_struct(fsp,
 535                                 fsp->op->global->open_persistent_id,
 536                                 in_offset,
 537                                 in_length,
 538                                 READ_LOCK,
 539                                 &lock);
 540
 541         if (!SMB_VFS_STRICT_LOCK(conn, fsp, &lock)) {
 542                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 543                 return tevent_req_post(req, ev);
 544         }
 545
 546         /* Try sendfile in preference. */
 547         status = schedule_smb2_sendfile_read(smb2req, state);
 548         if (NT_STATUS_IS_OK(status)) {
 549                 tevent_req_done(req);
 550                 return tevent_req_post(req, ev);
 551         } else {
 552                 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 553                         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 554                         tevent_req_nterror(req, status);
 555                         return tevent_req_post(req, ev);
 556                 }
 557         }
 558
 559         /* Ok, read into memory. Allocate the out buffer. */
 560         state->out_data = data_blob_talloc(state, NULL, in_length);
 561         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 562                 SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 563                 return tevent_req_post(req, ev);
 564         }
 565
 566         nread = read_file(fsp,
 567                           (char *)state->out_data.data,
 568                           in_offset,
 569                           in_length);
 570
 571         saved_errno = errno;
 572
 573         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 574
 575         DEBUG(10,("smbd_smb2_read: file %s, %s, offset=%llu "
 576                 "len=%llu returned %lld\n",
 577                 fsp_str_dbg(fsp),
 578                 fsp_fnum_dbg(fsp),
 579                 (unsigned long long)in_offset,
 580                 (unsigned long long)in_length,
 581                 (long long)nread));
 582
 583         status = smb2_read_complete(req, nread, saved_errno);
 584         if (!NT_STATUS_IS_OK(status)) {
 585                 tevent_req_nterror(req, status);
 586         } else {
 587                 /* Success. */
 588                 tevent_req_done(req);
 589         }
 590         return tevent_req_post(req, ev);
 591 }
 592
 593 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 594 {
 595         struct tevent_req *req = tevent_req_callback_data(subreq,
 596                                  struct tevent_req);
 597         struct smbd_smb2_read_state *state = tevent_req_data(req,
 598                                              struct smbd_smb2_read_state);
 599         NTSTATUS status;
 600         ssize_t nread = -1;
 601         bool is_data_outstanding;
 602
 603         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 604         TALLOC_FREE(subreq);
 605         if (!NT_STATUS_IS_OK(status)) {
 606                 NTSTATUS old = status;
 607                 status = nt_status_np_pipe(old);
 608                 tevent_req_nterror(req, status);
 609                 return;
 610         }
 611
 612         if (nread == 0 && state->out_data.length != 0) {
 613                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 614                 return;
 615         }
 616
 617         state->out_data.length = nread;
 618         state->out_remaining = 0;
 619
 620         /*
 621          * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
 622          * handle it in SMB1 pipe_read_andx_done().
 623          */
 624
 625         tevent_req_done(req);
 626 }
 627
 628 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 629                                     TALLOC_CTX *mem_ctx,
 630                                     DATA_BLOB *out_data,
 631                                     uint32_t *out_remaining)
 632 {
 633         NTSTATUS status;
 634         struct smbd_smb2_read_state *state = tevent_req_data(req,
 635                                              struct smbd_smb2_read_state);
 636
 637         if (tevent_req_is_nterror(req, &status)) {
 638                 tevent_req_received(req);
 639                 return status;
 640         }
 641
 642         *out_data = state->out_data;
 643         talloc_steal(mem_ctx, out_data->data);
 644         *out_remaining = state->out_remaining;
 645
 646         if (state->out_headers.length > 0) {
 647                 talloc_steal(mem_ctx, state);
 648                 talloc_set_destructor(state, smb2_smb2_read_state_deny_destructor);
 649                 tevent_req_received(req);
 650                 state->smb2req->queue_entry.sendfile_header = &state->out_headers;
 651                 talloc_set_destructor(state, smb2_sendfile_send_data);
 652         } else {
 653                 tevent_req_received(req);
 654         }
 655
 656         return NT_STATUS_OK;
 657 }