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         uint16_t body_size;
 120         uint8_t body_padding = req->xconn->smb2.smbtorture.read_body_padding;
 121         DATA_BLOB outbody;
 122         DATA_BLOB outdyn;
 123         uint8_t out_data_offset;
 124         DATA_BLOB out_data_buffer = data_blob_null;
 125         uint32_t out_data_remaining = 0;
 126         NTSTATUS status;
 127         NTSTATUS error; /* transport error */
 128
 129         status = smbd_smb2_read_recv(subreq,
 130                                      req,
 131                                      &out_data_buffer,
 132                                      &out_data_remaining);
 133         TALLOC_FREE(subreq);
 134         if (!NT_STATUS_IS_OK(status)) {
 135                 error = smbd_smb2_request_error(req, status);
 136                 if (!NT_STATUS_IS_OK(error)) {
 137                         smbd_server_connection_terminate(req->xconn,
 138                                                          nt_errstr(error));
 139                         return;
 140                 }
 141                 return;
 142         }
 143
 144         /*
 145          * Only FSCTL_SMBTORTURE_GLOBAL_READ_RESPONSE_BODY_PADDING8
 146          * sets body_padding to a value different from 0.
 147          */
 148         body_size = 0x10 + body_padding;
 149         out_data_offset = SMB2_HDR_BODY + body_size;
 150
 151         outbody = smbd_smb2_generate_outbody(req, body_size);
 152         if (outbody.data == NULL) {
 153                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 154                 if (!NT_STATUS_IS_OK(error)) {
 155                         smbd_server_connection_terminate(req->xconn,
 156                                                          nt_errstr(error));
 157                         return;
 158                 }
 159                 return;
 160         }
 161
 162         SSVAL(outbody.data, 0x00, 0x10 + 1);    /* struct size */
 163         SCVAL(outbody.data, 0x02,
 164               out_data_offset);                 /* data offset */
 165         SCVAL(outbody.data, 0x03, 0);           /* reserved */
 166         SIVAL(outbody.data, 0x04,
 167               out_data_buffer.length);          /* data length */
 168         SIVAL(outbody.data, 0x08,
 169               out_data_remaining);              /* data remaining */
 170         SIVAL(outbody.data, 0x0C, 0);           /* reserved */
 171         if (body_padding != 0) {
 172                 memset(outbody.data + 0x10, 0, body_padding);
 173         }
 174
 175         outdyn = out_data_buffer;
 176
 177         error = smbd_smb2_request_done(req, outbody, &outdyn);
 178         if (!NT_STATUS_IS_OK(error)) {
 179                 smbd_server_connection_terminate(req->xconn,
 180                                                  nt_errstr(error));
 181                 return;
 182         }
 183 }
 184
 185 struct smbd_smb2_read_state {
 186         struct smbd_smb2_request *smb2req;
 187         struct smb_request *smbreq;
 188         files_struct *fsp;
 189         uint8_t in_flags;
 190         uint32_t in_length;
 191         uint64_t in_offset;
 192         uint32_t in_minimum;
 193         DATA_BLOB out_headers;
 194         uint8_t _out_hdr_buf[NBT_HDR_SIZE + SMB2_HDR_BODY + 0x10];
 195         DATA_BLOB out_data;
 196         uint32_t out_remaining;
 197 };
 198
 199 static int smb2_smb2_read_state_deny_destructor(struct smbd_smb2_read_state *state)
 200 {
 201         return -1;
 202 }
 203
 204 /* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
 205 static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
 206 {
 207         struct lock_struct lock;
 208         uint32_t in_length = state->in_length;
 209         uint64_t in_offset = state->in_offset;
 210         files_struct *fsp = state->fsp;
 211         const DATA_BLOB *hdr = state->smb2req->queue_entry.sendfile_header;
 212         NTSTATUS *pstatus = state->smb2req->queue_entry.sendfile_status;
 213         struct smbXsrv_connection *xconn = state->smb2req->xconn;
 214         ssize_t nread;
 215         ssize_t ret;
 216         int saved_errno;
 217
 218         nread = SMB_VFS_SENDFILE(xconn->transport.sock,
 219                                  fsp,
 220                                  hdr,
 221                                  in_offset,
 222                                  in_length);
 223         DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
 224                 (int)nread,
 225                 fsp_str_dbg(fsp) ));
 226
 227         if (nread == -1) {
 228                 saved_errno = errno;
 229
 230                 /*
 231                  * Returning ENOSYS means no data at all was sent.
 232                    Do this as a normal read. */
 233                 if (errno == ENOSYS) {
 234                         goto normal_read;
 235                 }
 236
 237                 if (errno == ENOTSUP) {
 238                         set_use_sendfile(SNUM(fsp->conn), false);
 239                         DBG_WARNING("Disabling sendfile use as sendfile is "
 240                                     "not supported by the system\n");
 241                         goto normal_read;
 242                 }
 243
 244                 if (errno == EINTR) {
 245                         /*
 246                          * Special hack for broken Linux with no working sendfile. If we
 247                          * return EINTR we sent the header but not the rest of the data.
 248                          * Fake this up by doing read/write calls.
 249                          */
 250                         set_use_sendfile(SNUM(fsp->conn), false);
 251                         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 252                         if (nread == -1) {
 253                                 saved_errno = errno;
 254                                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 255                                          "failed for file %s (%s) for client %s. "
 256                                          "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                         }
 262                         goto out;
 263                 }
 264
 265                 DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
 266                          "%s (%s) for client %s. Terminating\n",
 267                          fsp_str_dbg(fsp), strerror(saved_errno),
 268                          smbXsrv_connection_dbg(xconn)));
 269                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 270                 return 0;
 271         } else if (nread == 0) {
 272                 /*
 273                  * Some sendfile implementations return 0 to indicate
 274                  * that there was a short read, but nothing was
 275                  * actually written to the socket.  In this case,
 276                  * fallback to the normal read path so the header gets
 277                  * the correct byte count.
 278                  */
 279                 DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
 280                         "falling back to the normal read: %s\n",
 281                         fsp_str_dbg(fsp)));
 282                 goto normal_read;
 283         }
 284
 285         /*
 286          * We got a short read
 287          */
 288         goto out;
 289
 290 normal_read:
 291         /* Send out the header. */
 292         ret = write_data(xconn->transport.sock,
 293                          (const char *)hdr->data, hdr->length);
 294         if (ret != hdr->length) {
 295                 saved_errno = errno;
 296                 DEBUG(0,("smb2_sendfile_send_data: write_data failed for file "
 297                          "%s (%s) for client %s. Terminating\n",
 298                          fsp_str_dbg(fsp), strerror(saved_errno),
 299                          smbXsrv_connection_dbg(xconn)));
 300                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 301                 return 0;
 302         }
 303         nread = fake_sendfile(xconn, fsp, in_offset, in_length);
 304         if (nread == -1) {
 305                 saved_errno = errno;
 306                 DEBUG(0,("smb2_sendfile_send_data: fake_sendfile "
 307                          "failed for file %s (%s) for client %s. "
 308                          "Terminating\n",
 309                          fsp_str_dbg(fsp), strerror(saved_errno),
 310                          smbXsrv_connection_dbg(xconn)));
 311                 *pstatus = map_nt_error_from_unix_common(saved_errno);
 312                 return 0;
 313         }
 314
 315   out:
 316
 317         if (nread < in_length) {
 318                 ret = sendfile_short_send(xconn, fsp, nread,
 319                                           hdr->length, in_length);
 320                 if (ret == -1) {
 321                         saved_errno = errno;
 322                         DEBUG(0,("%s: sendfile_short_send "
 323                                  "failed for file %s (%s) for client %s. "
 324                                  "Terminating\n",
 325                                  __func__,
 326                                  fsp_str_dbg(fsp), strerror(saved_errno),
 327                                  smbXsrv_connection_dbg(xconn)));
 328                         *pstatus = map_nt_error_from_unix_common(saved_errno);
 329                         return 0;
 330                 }
 331         }
 332
 333         init_strict_lock_struct(fsp,
 334                                 fsp->op->global->open_persistent_id,
 335                                 in_offset,
 336                                 in_length,
 337                                 READ_LOCK,
 338                                 lp_posix_cifsu_locktype(fsp),
 339                                 &lock);
 340
 341         *pstatus = NT_STATUS_OK;
 342         return 0;
 343 }
 344
 345 static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
 346                                         struct smbd_smb2_read_state *state)
 347 {
 348         files_struct *fsp = state->fsp;
 349
 350         /*
 351          * We cannot use sendfile if...
 352          * We were not configured to do so OR
 353          * Signing is active OR
 354          * This is a compound SMB2 operation OR
 355          * fsp is a STREAM file OR
 356          * We're using a write cache OR
 357          * It's not a regular file OR
 358          * Requested offset is greater than file size OR
 359          * there's not enough data in the file.
 360          * Phew :-). Luckily this means most
 361          * reads on most normal files. JRA.
 362         */
 363
 364         if (!lp__use_sendfile(SNUM(fsp->conn)) ||
 365             smb2req->do_signing ||
 366             smb2req->do_encryption ||
 367             smbd_smb2_is_compound(smb2req) ||
 368             fsp_is_alternate_stream(fsp) ||
 369             (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
 370             (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
 371             (fsp->fsp_name->st.st_ex_size < state->in_offset + state->in_length))
 372         {
 373                 return NT_STATUS_RETRY;
 374         }
 375
 376         /* We've already checked there's this amount of data
 377            to read. */
 378         state->out_data.length = state->in_length;
 379         state->out_remaining = 0;
 380
 381         state->out_headers = data_blob_const(state->_out_hdr_buf,
 382                                              sizeof(state->_out_hdr_buf));
 383         return NT_STATUS_OK;
 384 }
 385
 386 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 387
 388 /*******************************************************************
 389  Common read complete processing function for both synchronous and
 390  asynchronous reads.
 391 *******************************************************************/
 392
 393 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 394 {
 395         struct smbd_smb2_read_state *state = tevent_req_data(req,
 396                                         struct smbd_smb2_read_state);
 397         files_struct *fsp = state->fsp;
 398
 399         if (nread < 0) {
 400                 NTSTATUS status = map_nt_error_from_unix(err);
 401
 402                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 403                         "Error = %s (NTSTATUS %s)\n",
 404                         fsp_str_dbg(fsp),
 405                         (int)nread,
 406                         strerror(err),
 407                         nt_errstr(status)));
 408
 409                 return status;
 410         }
 411         if (nread == 0 && state->in_length != 0) {
 412                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 413                         fsp_str_dbg(fsp)));
 414                 return NT_STATUS_END_OF_FILE;
 415         }
 416
 417         if (nread < state->in_minimum) {
 418                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 419                         "minimum requested %u. Returning end of file\n",
 420                         fsp_str_dbg(fsp),
 421                         (int)nread,
 422                         (unsigned int)state->in_minimum));
 423                 return NT_STATUS_END_OF_FILE;
 424         }
 425
 426         DEBUG(3,("smbd_smb2_read: %s, file %s, length=%lu offset=%lu read=%lu\n",
 427                 fsp_fnum_dbg(fsp),
 428                 fsp_str_dbg(fsp),
 429                 (unsigned long)state->in_length,
 430                 (unsigned long)state->in_offset,
 431                 (unsigned long)nread));
 432
 433         state->out_data.length = nread;
 434         state->out_remaining = 0;
 435
 436         return NT_STATUS_OK;
 437 }
 438
 439 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 440 {
 441         struct smbd_smb2_read_state *state =
 442                 tevent_req_data(req,
 443                 struct smbd_smb2_read_state);
 444
 445         return cancel_smb2_aio(state->smbreq);
 446 }
 447
 448 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 449                                               struct tevent_context *ev,
 450                                               struct smbd_smb2_request *smb2req,
 451                                               struct files_struct *fsp,
 452                                               uint8_t in_flags,
 453                                               uint32_t in_length,
 454                                               uint64_t in_offset,
 455                                               uint32_t in_minimum,
 456                                               uint32_t in_remaining)
 457 {
 458         NTSTATUS status;
 459         struct tevent_req *req = NULL;
 460         struct smbd_smb2_read_state *state = NULL;
 461         struct smb_request *smbreq = NULL;
 462         connection_struct *conn = smb2req->tcon->compat;
 463         ssize_t nread = -1;
 464         struct lock_struct lock;
 465         int saved_errno;
 466
 467         req = tevent_req_create(mem_ctx, &state,
 468                                 struct smbd_smb2_read_state);
 469         if (req == NULL) {
 470                 return NULL;
 471         }
 472         state->smb2req = smb2req;
 473         state->in_flags = in_flags;
 474         state->in_length = in_length;
 475         state->in_offset = in_offset;
 476         state->in_minimum = in_minimum;
 477         state->out_data = data_blob_null;
 478         state->out_remaining = 0;
 479
 480         DEBUG(10,("smbd_smb2_read: %s - %s\n",
 481                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 482
 483         smbreq = smbd_smb2_fake_smb_request(smb2req, fsp);
 484         if (tevent_req_nomem(smbreq, req)) {
 485                 return tevent_req_post(req, ev);
 486         }
 487         state->smbreq = smbreq;
 488
 489         if (fsp->fsp_flags.is_directory) {
 490                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 491                 return tevent_req_post(req, ev);
 492         }
 493
 494         state->fsp = fsp;
 495
 496         if (IS_IPC(smbreq->conn)) {
 497                 struct tevent_req *subreq = NULL;
 498
 499                 state->out_data = data_blob_talloc(state, NULL, in_length);
 500                 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 501                         return tevent_req_post(req, ev);
 502                 }
 503
 504                 if (!fsp_is_np(fsp)) {
 505                         tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 506                         return tevent_req_post(req, ev);
 507                 }
 508
 509                 subreq = np_read_send(state, ev,
 510                                       fsp->fake_file_handle,
 511                                       state->out_data.data,
 512                                       state->out_data.length);
 513                 if (tevent_req_nomem(subreq, req)) {
 514                         return tevent_req_post(req, ev);
 515                 }
 516                 tevent_req_set_callback(subreq,
 517                                         smbd_smb2_read_pipe_done,
 518                                         req);
 519                 return req;
 520         }
 521
 522         if (!CHECK_READ_SMB2(fsp)) {
 523                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 524                 return tevent_req_post(req, ev);
 525         }
 526
 527         status = schedule_smb2_aio_read(fsp->conn,
 528                                 smbreq,
 529                                 fsp,
 530                                 state,
 531                                 &state->out_data,
 532                                 (off_t)in_offset,
 533                                 (size_t)in_length);
 534
 535         if (NT_STATUS_IS_OK(status)) {
 536                 /*
 537                  * Doing an async read, allow this
 538                  * request to be canceled
 539                  */
 540                 tevent_req_set_cancel_fn(req, smbd_smb2_read_cancel);
 541                 return req;
 542         }
 543
 544         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 545                 /* Real error in setting up aio. Fail. */
 546                 tevent_req_nterror(req, status);
 547                 return tevent_req_post(req, ev);
 548         }
 549
 550         /* Fallback to synchronous. */
 551
 552         init_strict_lock_struct(fsp,
 553                                 fsp->op->global->open_persistent_id,
 554                                 in_offset,
 555                                 in_length,
 556                                 READ_LOCK,
 557                                 lp_posix_cifsu_locktype(fsp),
 558                                 &lock);
 559
 560         if (!SMB_VFS_STRICT_LOCK_CHECK(conn, fsp, &lock)) {
 561                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 562                 return tevent_req_post(req, ev);
 563         }
 564
 565         /* Try sendfile in preference. */
 566         status = schedule_smb2_sendfile_read(smb2req, state);
 567         if (NT_STATUS_IS_OK(status)) {
 568                 tevent_req_done(req);
 569                 return tevent_req_post(req, ev);
 570         } else {
 571                 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 572                         tevent_req_nterror(req, status);
 573                         return tevent_req_post(req, ev);
 574                 }
 575         }
 576
 577         /* Ok, read into memory. Allocate the out buffer. */
 578         state->out_data = data_blob_talloc(state, NULL, in_length);
 579         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 580                 return tevent_req_post(req, ev);
 581         }
 582
 583         nread = read_file(fsp,
 584                           (char *)state->out_data.data,
 585                           in_offset,
 586                           in_length);
 587
 588         saved_errno = errno;
 589
 590         DEBUG(10,("smbd_smb2_read: file %s, %s, offset=%llu "
 591                 "len=%llu returned %lld\n",
 592                 fsp_str_dbg(fsp),
 593                 fsp_fnum_dbg(fsp),
 594                 (unsigned long long)in_offset,
 595                 (unsigned long long)in_length,
 596                 (long long)nread));
 597
 598         status = smb2_read_complete(req, nread, saved_errno);
 599         if (!NT_STATUS_IS_OK(status)) {
 600                 tevent_req_nterror(req, status);
 601         } else {
 602                 /* Success. */
 603                 tevent_req_done(req);
 604         }
 605         return tevent_req_post(req, ev);
 606 }
 607
 608 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 609 {
 610         struct tevent_req *req = tevent_req_callback_data(subreq,
 611                                  struct tevent_req);
 612         struct smbd_smb2_read_state *state = tevent_req_data(req,
 613                                              struct smbd_smb2_read_state);
 614         NTSTATUS status;
 615         ssize_t nread = -1;
 616         bool is_data_outstanding;
 617
 618         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 619         TALLOC_FREE(subreq);
 620         if (!NT_STATUS_IS_OK(status)) {
 621                 NTSTATUS old = status;
 622                 status = nt_status_np_pipe(old);
 623                 tevent_req_nterror(req, status);
 624                 return;
 625         }
 626
 627         if (nread == 0 && state->out_data.length != 0) {
 628                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 629                 return;
 630         }
 631
 632         state->out_data.length = nread;
 633         state->out_remaining = 0;
 634
 635         /*
 636          * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
 637          * handle it in SMB1 pipe_read_andx_done().
 638          */
 639
 640         tevent_req_done(req);
 641 }
 642
 643 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 644                                     TALLOC_CTX *mem_ctx,
 645                                     DATA_BLOB *out_data,
 646                                     uint32_t *out_remaining)
 647 {
 648         NTSTATUS status;
 649         struct smbd_smb2_read_state *state = tevent_req_data(req,
 650                                              struct smbd_smb2_read_state);
 651
 652         if (tevent_req_is_nterror(req, &status)) {
 653                 tevent_req_received(req);
 654                 return status;
 655         }
 656
 657         *out_data = state->out_data;
 658         talloc_steal(mem_ctx, out_data->data);
 659         *out_remaining = state->out_remaining;
 660
 661         if (state->out_headers.length > 0) {
 662                 talloc_steal(mem_ctx, state);
 663                 talloc_set_destructor(state, smb2_smb2_read_state_deny_destructor);
 664                 tevent_req_received(req);
 665                 state->smb2req->queue_entry.sendfile_header = &state->out_headers;
 666                 state->smb2req->queue_entry.sendfile_body_size = state->in_length;
 667                 talloc_set_destructor(state, smb2_sendfile_send_data);
 668         } else {
 669                 tevent_req_received(req);
 670         }
 671
 672         return NT_STATUS_OK;
 673 }