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          * It's not a regular file OR
 357          * Requested offset is greater than file size OR
 358          * there's not enough data in the file.
 359          * Phew :-). Luckily this means most
 360          * reads on most normal files. JRA.
 361         */
 362
 363         if (!lp__use_sendfile(SNUM(fsp->conn)) ||
 364             smb2req->do_signing ||
 365             smb2req->do_encryption ||
 366             smbd_smb2_is_compound(smb2req) ||
 367             fsp_is_alternate_stream(fsp) ||
 368             (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
 369             (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
 370             (fsp->fsp_name->st.st_ex_size < state->in_offset + state->in_length))
 371         {
 372                 return NT_STATUS_RETRY;
 373         }
 374
 375         /* We've already checked there's this amount of data
 376            to read. */
 377         state->out_data.length = state->in_length;
 378         state->out_remaining = 0;
 379
 380         state->out_headers = data_blob_const(state->_out_hdr_buf,
 381                                              sizeof(state->_out_hdr_buf));
 382         return NT_STATUS_OK;
 383 }
 384
 385 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 386
 387 /*******************************************************************
 388  Common read complete processing function for both synchronous and
 389  asynchronous reads.
 390 *******************************************************************/
 391
 392 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 393 {
 394         struct smbd_smb2_read_state *state = tevent_req_data(req,
 395                                         struct smbd_smb2_read_state);
 396         files_struct *fsp = state->fsp;
 397
 398         if (nread < 0) {
 399                 NTSTATUS status = map_nt_error_from_unix(err);
 400
 401                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 402                         "Error = %s (NTSTATUS %s)\n",
 403                         fsp_str_dbg(fsp),
 404                         (int)nread,
 405                         strerror(err),
 406                         nt_errstr(status)));
 407
 408                 return status;
 409         }
 410         if (nread == 0 && state->in_length != 0) {
 411                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 412                         fsp_str_dbg(fsp)));
 413                 return NT_STATUS_END_OF_FILE;
 414         }
 415
 416         if (nread < state->in_minimum) {
 417                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 418                         "minimum requested %u. Returning end of file\n",
 419                         fsp_str_dbg(fsp),
 420                         (int)nread,
 421                         (unsigned int)state->in_minimum));
 422                 return NT_STATUS_END_OF_FILE;
 423         }
 424
 425         DEBUG(3,("smbd_smb2_read: %s, file %s, length=%lu offset=%lu read=%lu\n",
 426                 fsp_fnum_dbg(fsp),
 427                 fsp_str_dbg(fsp),
 428                 (unsigned long)state->in_length,
 429                 (unsigned long)state->in_offset,
 430                 (unsigned long)nread));
 431
 432         state->out_data.length = nread;
 433         state->out_remaining = 0;
 434
 435         return NT_STATUS_OK;
 436 }
 437
 438 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 439 {
 440         struct smbd_smb2_read_state *state =
 441                 tevent_req_data(req,
 442                 struct smbd_smb2_read_state);
 443
 444         return cancel_smb2_aio(state->smbreq);
 445 }
 446
 447 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 448                                               struct tevent_context *ev,
 449                                               struct smbd_smb2_request *smb2req,
 450                                               struct files_struct *fsp,
 451                                               uint8_t in_flags,
 452                                               uint32_t in_length,
 453                                               uint64_t in_offset,
 454                                               uint32_t in_minimum,
 455                                               uint32_t in_remaining)
 456 {
 457         NTSTATUS status;
 458         struct tevent_req *req = NULL;
 459         struct smbd_smb2_read_state *state = NULL;
 460         struct smb_request *smbreq = NULL;
 461         connection_struct *conn = smb2req->tcon->compat;
 462         ssize_t nread = -1;
 463         struct lock_struct lock;
 464         int saved_errno;
 465
 466         req = tevent_req_create(mem_ctx, &state,
 467                                 struct smbd_smb2_read_state);
 468         if (req == NULL) {
 469                 return NULL;
 470         }
 471         state->smb2req = smb2req;
 472         state->in_flags = in_flags;
 473         state->in_length = in_length;
 474         state->in_offset = in_offset;
 475         state->in_minimum = in_minimum;
 476         state->out_data = data_blob_null;
 477         state->out_remaining = 0;
 478
 479         DEBUG(10,("smbd_smb2_read: %s - %s\n",
 480                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 481
 482         smbreq = smbd_smb2_fake_smb_request(smb2req, fsp);
 483         if (tevent_req_nomem(smbreq, req)) {
 484                 return tevent_req_post(req, ev);
 485         }
 486         state->smbreq = smbreq;
 487
 488         if (fsp->fsp_flags.is_directory) {
 489                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 490                 return tevent_req_post(req, ev);
 491         }
 492
 493         state->fsp = fsp;
 494
 495         if (IS_IPC(smbreq->conn)) {
 496                 struct tevent_req *subreq = NULL;
 497                 bool ok;
 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
 520                 /*
 521                  * Make sure we mark the fsp as having outstanding async
 522                  * activity so we don't crash on shutdown close.
 523                  */
 524
 525                 ok = aio_add_req_to_fsp(fsp, req);
 526                 if (!ok) {
 527                         tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
 528                         return tevent_req_post(req, ev);
 529                 }
 530
 531                 return req;
 532         }
 533
 534         if (!CHECK_READ_SMB2(fsp)) {
 535                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 536                 return tevent_req_post(req, ev);
 537         }
 538
 539         status = schedule_smb2_aio_read(fsp->conn,
 540                                 smbreq,
 541                                 fsp,
 542                                 state,
 543                                 &state->out_data,
 544                                 (off_t)in_offset,
 545                                 (size_t)in_length);
 546
 547         if (NT_STATUS_IS_OK(status)) {
 548                 /*
 549                  * Doing an async read, allow this
 550                  * request to be canceled
 551                  */
 552                 tevent_req_set_cancel_fn(req, smbd_smb2_read_cancel);
 553                 return req;
 554         }
 555
 556         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 557                 /* Real error in setting up aio. Fail. */
 558                 tevent_req_nterror(req, status);
 559                 return tevent_req_post(req, ev);
 560         }
 561
 562         /* Fallback to synchronous. */
 563
 564         init_strict_lock_struct(fsp,
 565                                 fsp->op->global->open_persistent_id,
 566                                 in_offset,
 567                                 in_length,
 568                                 READ_LOCK,
 569                                 lp_posix_cifsu_locktype(fsp),
 570                                 &lock);
 571
 572         if (!SMB_VFS_STRICT_LOCK_CHECK(conn, fsp, &lock)) {
 573                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 574                 return tevent_req_post(req, ev);
 575         }
 576
 577         /* Try sendfile in preference. */
 578         status = schedule_smb2_sendfile_read(smb2req, state);
 579         if (NT_STATUS_IS_OK(status)) {
 580                 tevent_req_done(req);
 581                 return tevent_req_post(req, ev);
 582         } else {
 583                 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 584                         tevent_req_nterror(req, status);
 585                         return tevent_req_post(req, ev);
 586                 }
 587         }
 588
 589         /* Ok, read into memory. Allocate the out buffer. */
 590         state->out_data = data_blob_talloc(state, NULL, in_length);
 591         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 592                 return tevent_req_post(req, ev);
 593         }
 594
 595         nread = read_file(fsp,
 596                           (char *)state->out_data.data,
 597                           in_offset,
 598                           in_length);
 599
 600         saved_errno = errno;
 601
 602         DEBUG(10,("smbd_smb2_read: file %s, %s, offset=%llu "
 603                 "len=%llu returned %lld\n",
 604                 fsp_str_dbg(fsp),
 605                 fsp_fnum_dbg(fsp),
 606                 (unsigned long long)in_offset,
 607                 (unsigned long long)in_length,
 608                 (long long)nread));
 609
 610         status = smb2_read_complete(req, nread, saved_errno);
 611         if (!NT_STATUS_IS_OK(status)) {
 612                 tevent_req_nterror(req, status);
 613         } else {
 614                 /* Success. */
 615                 tevent_req_done(req);
 616         }
 617         return tevent_req_post(req, ev);
 618 }
 619
 620 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 621 {
 622         struct tevent_req *req = tevent_req_callback_data(subreq,
 623                                  struct tevent_req);
 624         struct smbd_smb2_read_state *state = tevent_req_data(req,
 625                                              struct smbd_smb2_read_state);
 626         NTSTATUS status;
 627         ssize_t nread = -1;
 628         bool is_data_outstanding;
 629
 630         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 631         TALLOC_FREE(subreq);
 632         if (!NT_STATUS_IS_OK(status)) {
 633                 NTSTATUS old = status;
 634                 status = nt_status_np_pipe(old);
 635                 tevent_req_nterror(req, status);
 636                 return;
 637         }
 638
 639         if (nread == 0 && state->out_data.length != 0) {
 640                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 641                 return;
 642         }
 643
 644         state->out_data.length = nread;
 645         state->out_remaining = 0;
 646
 647         /*
 648          * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
 649          * handle it in SMB1 pipe_read_andx_done().
 650          */
 651
 652         tevent_req_done(req);
 653 }
 654
 655 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 656                                     TALLOC_CTX *mem_ctx,
 657                                     DATA_BLOB *out_data,
 658                                     uint32_t *out_remaining)
 659 {
 660         NTSTATUS status;
 661         struct smbd_smb2_read_state *state = tevent_req_data(req,
 662                                              struct smbd_smb2_read_state);
 663
 664         if (tevent_req_is_nterror(req, &status)) {
 665                 tevent_req_received(req);
 666                 return status;
 667         }
 668
 669         *out_data = state->out_data;
 670         talloc_steal(mem_ctx, out_data->data);
 671         *out_remaining = state->out_remaining;
 672
 673         if (state->out_headers.length > 0) {
 674                 talloc_steal(mem_ctx, state);
 675                 talloc_set_destructor(state, smb2_smb2_read_state_deny_destructor);
 676                 tevent_req_received(req);
 677                 state->smb2req->queue_entry.sendfile_header = &state->out_headers;
 678                 state->smb2req->queue_entry.sendfile_body_size = state->in_length;
 679                 talloc_set_destructor(state, smb2_sendfile_send_data);
 680         } else {
 681                 tevent_req_received(req);
 682         }
 683
 684         return NT_STATUS_OK;
 685 }