source3/libsmb/clireadwrite.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    client file read/write routines
   4    Copyright (C) Andrew Tridgell 1994-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 /****************************************************************************
  23   Calculate the recommended read buffer size
  24 ****************************************************************************/
  25 static size_t cli_read_max_bufsize(struct cli_state *cli)
  26 {
  27         if (!client_is_signing_on(cli) && !cli_encryption_on(cli)
  28             && (cli->posix_capabilities & CIFS_UNIX_LARGE_READ_CAP)) {
  29                 return CLI_SAMBA_MAX_POSIX_LARGE_READX_SIZE;
  30         }
  31         if (cli->capabilities & CAP_LARGE_READX) {
  32                 return cli->is_samba
  33                         ? CLI_SAMBA_MAX_LARGE_READX_SIZE
  34                         : CLI_WINDOWS_MAX_LARGE_READX_SIZE;
  35         }
  36         return (cli->max_xmit - (smb_size+32)) & ~1023;
  37 }
  38
  39 /*
  40  * Send a read&x request
  41  */
  42
  43 struct async_req *cli_read_andx_send(TALLOC_CTX *mem_ctx,
  44                                      struct cli_state *cli, int fnum,
  45                                      off_t offset, size_t size)
  46 {
  47         struct async_req *result;
  48         struct cli_request *req;
  49         bool bigoffset = False;
  50         char *enc_buf;
  51
  52         if (size > cli_read_max_bufsize(cli)) {
  53                 DEBUG(0, ("cli_read_andx_send got size=%d, can only handle "
  54                           "size=%d\n", (int)size,
  55                           (int)cli_read_max_bufsize(cli)));
  56                 return NULL;
  57         }
  58
  59         result = cli_request_new(mem_ctx, cli->event_ctx, cli, 12, 0, &req);
  60         if (result == NULL) {
  61                 DEBUG(0, ("cli_request_new failed\n"));
  62                 return NULL;
  63         }
  64
  65         req = cli_request_get(result);
  66
  67         req->data.read.ofs = offset;
  68         req->data.read.size = size;
  69         req->data.read.received = 0;
  70         req->data.read.rcvbuf = NULL;
  71
  72         if ((SMB_BIG_UINT)offset >> 32)
  73                 bigoffset = True;
  74
  75         cli_set_message(req->outbuf, bigoffset ? 12 : 10, 0, False);
  76
  77         SCVAL(req->outbuf,smb_com,SMBreadX);
  78         SSVAL(req->outbuf,smb_tid,cli->cnum);
  79         cli_setup_packet_buf(cli, req->outbuf);
  80
  81         SCVAL(req->outbuf,smb_vwv0,0xFF);
  82         SCVAL(req->outbuf,smb_vwv0+1,0);
  83         SSVAL(req->outbuf,smb_vwv1,0);
  84         SSVAL(req->outbuf,smb_vwv2,fnum);
  85         SIVAL(req->outbuf,smb_vwv3,offset);
  86         SSVAL(req->outbuf,smb_vwv5,size);
  87         SSVAL(req->outbuf,smb_vwv6,size);
  88         SSVAL(req->outbuf,smb_vwv7,(size >> 16));
  89         SSVAL(req->outbuf,smb_vwv8,0);
  90         SSVAL(req->outbuf,smb_vwv9,0);
  91         SSVAL(req->outbuf,smb_mid,req->mid);
  92
  93         if (bigoffset) {
  94                 SIVAL(req->outbuf, smb_vwv10,
  95                       (((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
  96         }
  97
  98         cli_calculate_sign_mac(cli, req->outbuf);
  99
 100         event_fd_set_writeable(cli->fd_event);
 101
 102         if (cli_encryption_on(cli)) {
 103                 NTSTATUS status;
 104                 status = cli_encrypt_message(cli, req->outbuf, &enc_buf);
 105                 if (!NT_STATUS_IS_OK(status)) {
 106                         DEBUG(0, ("Error in encrypting client message. "
 107                                   "Error %s\n", nt_errstr(status)));
 108                         TALLOC_FREE(req);
 109                         return NULL;
 110                 }
 111                 req->outbuf = enc_buf;
 112                 req->enc_state = cli->trans_enc_state;
 113         }
 114
 115         return result;
 116 }
 117
 118 /*
 119  * Pull the data out of a finished async read_and_x request. rcvbuf is
 120  * talloced from the request, so better make sure that you copy it away before
 121  * you talloc_free(req). "rcvbuf" is NOT a talloc_ctx of its own, so do not
 122  * talloc_move it!
 123  */
 124
 125 NTSTATUS cli_read_andx_recv(struct async_req *req, ssize_t *received,
 126                             uint8_t **rcvbuf)
 127 {
 128         struct cli_request *cli_req = cli_request_get(req);
 129         NTSTATUS status;
 130         size_t size;
 131
 132         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 133         if (req->state == ASYNC_REQ_ERROR) {
 134                 return req->status;
 135         }
 136
 137         status = cli_pull_error(cli_req->inbuf);
 138
 139         if (NT_STATUS_IS_ERR(status)) {
 140                 return status;
 141         }
 142
 143         /* size is the number of bytes the server returned.
 144          * Might be zero. */
 145         size = SVAL(cli_req->inbuf, smb_vwv5);
 146         size |= (((unsigned int)(SVAL(cli_req->inbuf, smb_vwv7))) << 16);
 147
 148         if (size > cli_req->data.read.size) {
 149                 DEBUG(5,("server returned more than we wanted!\n"));
 150                 return NT_STATUS_UNEXPECTED_IO_ERROR;
 151         }
 152
 153         *rcvbuf = (uint8_t *)
 154                 (smb_base(cli_req->inbuf) + SVAL(cli_req->inbuf, smb_vwv6));
 155         *received = size;
 156         return NT_STATUS_OK;
 157 }
 158
 159 /*
 160  * Parallel read support.
 161  *
 162  * cli_pull sends as many read&x requests as the server would allow via
 163  * max_mux at a time. When replies flow back in, the data is written into
 164  * the callback function "sink" in the right order.
 165  */
 166
 167 struct cli_pull_state {
 168         struct async_req *req;
 169
 170         struct cli_state *cli;
 171         uint16_t fnum;
 172         off_t start_offset;
 173         SMB_OFF_T size;
 174
 175         NTSTATUS (*sink)(char *buf, size_t n, void *priv);
 176         void *priv;
 177
 178         size_t chunk_size;
 179
 180         /*
 181          * Outstanding requests
 182          */
 183         int num_reqs;
 184         struct async_req **reqs;
 185
 186         /*
 187          * For how many bytes did we send requests already?
 188          */
 189         SMB_OFF_T requested;
 190
 191         /*
 192          * Next request index to push into "sink". This walks around the "req"
 193          * array, taking care that the requests are pushed to "sink" in the
 194          * right order. If necessary (i.e. replies don't come in in the right
 195          * order), replies are held back in "reqs".
 196          */
 197         int top_req;
 198
 199         /*
 200          * How many bytes did we push into "sink"?
 201          */
 202
 203         SMB_OFF_T pushed;
 204 };
 205
 206 static char *cli_pull_print(TALLOC_CTX *mem_ctx, struct async_req *req)
 207 {
 208         struct cli_pull_state *state = talloc_get_type_abort(
 209                 req->private_data, struct cli_pull_state);
 210         char *result;
 211
 212         result = async_req_print(mem_ctx, req);
 213         if (result == NULL) {
 214                 return NULL;
 215         }
 216
 217         return talloc_asprintf_append_buffer(
 218                 result, "num_reqs=%d, top_req=%d",
 219                 state->num_reqs, state->top_req);
 220 }
 221
 222 static void cli_pull_read_done(struct async_req *read_req);
 223
 224 /*
 225  * Prepare an async pull request
 226  */
 227
 228 struct async_req *cli_pull_send(TALLOC_CTX *mem_ctx, struct cli_state *cli,
 229                                 uint16_t fnum, off_t start_offset,
 230                                 SMB_OFF_T size, size_t window_size,
 231                                 NTSTATUS (*sink)(char *buf, size_t n,
 232                                                  void *priv),
 233                                 void *priv)
 234 {
 235         struct async_req *result;
 236         struct cli_pull_state *state;
 237         int i;
 238
 239         result = async_req_new(mem_ctx, cli->event_ctx);
 240         if (result == NULL) {
 241                 goto failed;
 242         }
 243         state = talloc(result, struct cli_pull_state);
 244         if (state == NULL) {
 245                 goto failed;
 246         }
 247         result->private_data = state;
 248         result->print = cli_pull_print;
 249         state->req = result;
 250
 251         state->cli = cli;
 252         state->fnum = fnum;
 253         state->start_offset = start_offset;
 254         state->size = size;
 255         state->sink = sink;
 256         state->priv = priv;
 257
 258         state->pushed = 0;
 259         state->top_req = 0;
 260
 261         if (size == 0) {
 262                 if (!async_post_status(result, NT_STATUS_OK)) {
 263                         goto failed;
 264                 }
 265                 return result;
 266         }
 267
 268         state->chunk_size = cli_read_max_bufsize(cli);
 269
 270         state->num_reqs = MAX(window_size/state->chunk_size, 1);
 271         state->num_reqs = MIN(state->num_reqs, cli->max_mux);
 272
 273         state->reqs = TALLOC_ZERO_ARRAY(state, struct async_req *,
 274                                         state->num_reqs);
 275         if (state->reqs == NULL) {
 276                 goto failed;
 277         }
 278
 279         state->requested = 0;
 280
 281         for (i=0; i<state->num_reqs; i++) {
 282                 SMB_OFF_T size_left;
 283                 size_t request_thistime;
 284
 285                 if (state->requested >= size) {
 286                         state->num_reqs = i;
 287                         break;
 288                 }
 289
 290                 size_left = size - state->requested;
 291                 request_thistime = MIN(size_left, state->chunk_size);
 292
 293                 state->reqs[i] = cli_read_andx_send(
 294                         state->reqs, cli, fnum,
 295                         state->start_offset + state->requested,
 296                         request_thistime);
 297
 298                 if (state->reqs[i] == NULL) {
 299                         goto failed;
 300                 }
 301
 302                 state->reqs[i]->async.fn = cli_pull_read_done;
 303                 state->reqs[i]->async.priv = result;
 304
 305                 state->requested += request_thistime;
 306         }
 307         return result;
 308
 309 failed:
 310         TALLOC_FREE(result);
 311         return NULL;
 312 }
 313
 314 /*
 315  * Handle incoming read replies, push the data into sink and send out new
 316  * requests if necessary.
 317  */
 318
 319 static void cli_pull_read_done(struct async_req *read_req)
 320 {
 321         struct async_req *pull_req = talloc_get_type_abort(
 322                 read_req->async.priv, struct async_req);
 323         struct cli_pull_state *state = talloc_get_type_abort(
 324                 pull_req->private_data, struct cli_pull_state);
 325         struct cli_request *read_state = cli_request_get(read_req);
 326         NTSTATUS status;
 327
 328         status = cli_read_andx_recv(read_req, &read_state->data.read.received,
 329                                     &read_state->data.read.rcvbuf);
 330         if (!NT_STATUS_IS_OK(status)) {
 331                 async_req_error(state->req, status);
 332                 return;
 333         }
 334
 335         /*
 336          * This loop is the one to take care of out-of-order replies. All
 337          * pending requests are in state->reqs, state->reqs[top_req] is the
 338          * one that is to be pushed next. If however a request later than
 339          * top_req is replied to, then we can't push yet. If top_req is
 340          * replied to at a later point then, we need to push all the finished
 341          * requests.
 342          */
 343
 344         while (state->reqs[state->top_req] != NULL) {
 345                 struct cli_request *top_read;
 346
 347                 DEBUG(11, ("cli_pull_read_done: top_req = %d\n",
 348                            state->top_req));
 349
 350                 if (state->reqs[state->top_req]->state < ASYNC_REQ_DONE) {
 351                         DEBUG(11, ("cli_pull_read_done: top request not yet "
 352                                    "done\n"));
 353                         return;
 354                 }
 355
 356                 top_read = cli_request_get(state->reqs[state->top_req]);
 357
 358                 DEBUG(10, ("cli_pull_read_done: Pushing %d bytes, %d already "
 359                            "pushed\n", (int)top_read->data.read.received,
 360                            (int)state->pushed));
 361
 362                 status = state->sink((char *)top_read->data.read.rcvbuf,
 363                                      top_read->data.read.received,
 364                                      state->priv);
 365                 if (!NT_STATUS_IS_OK(status)) {
 366                         async_req_error(state->req, status);
 367                         return;
 368                 }
 369                 state->pushed += top_read->data.read.received;
 370
 371                 TALLOC_FREE(state->reqs[state->top_req]);
 372
 373                 if (state->requested < state->size) {
 374                         struct async_req *new_req;
 375                         SMB_OFF_T size_left;
 376                         size_t request_thistime;
 377
 378                         size_left = state->size - state->requested;
 379                         request_thistime = MIN(size_left, state->chunk_size);
 380
 381                         DEBUG(10, ("cli_pull_read_done: Requesting %d bytes "
 382                                    "at %d, position %d\n",
 383                                    (int)request_thistime,
 384                                    (int)(state->start_offset
 385                                          + state->requested),
 386                                    state->top_req));
 387
 388                         new_req = cli_read_andx_send(
 389                                 state->reqs, state->cli, state->fnum,
 390                                 state->start_offset + state->requested,
 391                                 request_thistime);
 392
 393                         if (async_req_nomem(new_req, state->req)) {
 394                                 return;
 395                         }
 396
 397                         new_req->async.fn = cli_pull_read_done;
 398                         new_req->async.priv = pull_req;
 399
 400                         state->reqs[state->top_req] = new_req;
 401                         state->requested += request_thistime;
 402                 }
 403
 404                 state->top_req = (state->top_req+1) % state->num_reqs;
 405         }
 406
 407         async_req_done(pull_req);
 408 }
 409
 410 NTSTATUS cli_pull_recv(struct async_req *req, SMB_OFF_T *received)
 411 {
 412         struct cli_pull_state *state = talloc_get_type_abort(
 413                 req->private_data, struct cli_pull_state);
 414
 415         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 416         if (req->state == ASYNC_REQ_ERROR) {
 417                 return req->status;
 418         }
 419         *received = state->pushed;
 420         return NT_STATUS_OK;
 421 }
 422
 423 NTSTATUS cli_pull(struct cli_state *cli, uint16_t fnum,
 424                   off_t start_offset, SMB_OFF_T size, size_t window_size,
 425                   NTSTATUS (*sink)(char *buf, size_t n, void *priv),
 426                   void *priv, SMB_OFF_T *received)
 427 {
 428         TALLOC_CTX *frame = talloc_stackframe();
 429         struct async_req *req;
 430         NTSTATUS result = NT_STATUS_NO_MEMORY;
 431
 432         if (cli_tmp_event_ctx(frame, cli) == NULL) {
 433                 goto nomem;
 434         }
 435
 436         req = cli_pull_send(frame, cli, fnum, start_offset, size, window_size,
 437                             sink, priv);
 438         if (req == NULL) {
 439                 goto nomem;
 440         }
 441
 442         while (req->state < ASYNC_REQ_DONE) {
 443                 event_loop_once(cli->event_ctx);
 444         }
 445
 446         result = cli_pull_recv(req, received);
 447  nomem:
 448         TALLOC_FREE(frame);
 449         return result;
 450 }
 451
 452 static NTSTATUS cli_read_sink(char *buf, size_t n, void *priv)
 453 {
 454         char **pbuf = (char **)priv;
 455         memcpy(*pbuf, buf, n);
 456         *pbuf += n;
 457         return NT_STATUS_OK;
 458 }
 459
 460 ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 461                  off_t offset, size_t size)
 462 {
 463         NTSTATUS status;
 464         SMB_OFF_T ret;
 465
 466         status = cli_pull(cli, fnum, offset, size, size,
 467                           cli_read_sink, &buf, &ret);
 468         if (!NT_STATUS_IS_OK(status)) {
 469                 cli_set_error(cli, status);
 470                 return -1;
 471         }
 472         return ret;
 473 }
 474
 475 /****************************************************************************
 476  Issue a single SMBwrite and don't wait for a reply.
 477 ****************************************************************************/
 478
 479 static bool cli_issue_write(struct cli_state *cli,
 480                                 int fnum,
 481                                 off_t offset,
 482                                 uint16 mode,
 483                                 const char *buf,
 484                                 size_t size,
 485                                 int i)
 486 {
 487         char *p;
 488         bool large_writex = false;
 489         /* We can only do direct writes if not signing and not encrypting. */
 490         bool direct_writes = !client_is_signing_on(cli) && !cli_encryption_on(cli);
 491
 492         if (!direct_writes && size + 1 > cli->bufsize) {
 493                 cli->outbuf = (char *)SMB_REALLOC(cli->outbuf, size + 1024);
 494                 if (!cli->outbuf) {
 495                         return False;
 496                 }
 497                 cli->inbuf = (char *)SMB_REALLOC(cli->inbuf, size + 1024);
 498                 if (cli->inbuf == NULL) {
 499                         SAFE_FREE(cli->outbuf);
 500                         return False;
 501                 }
 502                 cli->bufsize = size + 1024;
 503         }
 504
 505         memset(cli->outbuf,'\0',smb_size);
 506         memset(cli->inbuf,'\0',smb_size);
 507
 508         if (cli->capabilities & CAP_LARGE_FILES) {
 509                 large_writex = True;
 510         }
 511
 512         if (large_writex) {
 513                 cli_set_message(cli->outbuf,14,0,True);
 514         } else {
 515                 cli_set_message(cli->outbuf,12,0,True);
 516         }
 517
 518         SCVAL(cli->outbuf,smb_com,SMBwriteX);
 519         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 520         cli_setup_packet(cli);
 521
 522         SCVAL(cli->outbuf,smb_vwv0,0xFF);
 523         SSVAL(cli->outbuf,smb_vwv2,fnum);
 524
 525         SIVAL(cli->outbuf,smb_vwv3,offset);
 526         SIVAL(cli->outbuf,smb_vwv5,0);
 527         SSVAL(cli->outbuf,smb_vwv7,mode);
 528
 529         SSVAL(cli->outbuf,smb_vwv8,(mode & 0x0008) ? size : 0);
 530         /*
 531          * According to CIFS-TR-1p00, this following field should only
 532          * be set if CAP_LARGE_WRITEX is set. We should check this
 533          * locally. However, this check might already have been
 534          * done by our callers.
 535          */
 536         SSVAL(cli->outbuf,smb_vwv9,(size>>16));
 537         SSVAL(cli->outbuf,smb_vwv10,size);
 538         /* +1 is pad byte. */
 539         SSVAL(cli->outbuf,smb_vwv11,
 540               smb_buf(cli->outbuf) - smb_base(cli->outbuf) + 1);
 541
 542         if (large_writex) {
 543                 SIVAL(cli->outbuf,smb_vwv12,(((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
 544         }
 545
 546         p = smb_base(cli->outbuf) + SVAL(cli->outbuf,smb_vwv11) -1;
 547         *p++ = '\0'; /* pad byte. */
 548         if (!direct_writes) {
 549                 memcpy(p, buf, size);
 550         }
 551         if (size > 0x1FFFF) {
 552                 /* This is a POSIX 14 word large write. */
 553                 set_message_bcc(cli->outbuf, 0); /* Set bcc to zero. */
 554                 _smb_setlen_large(cli->outbuf,smb_size + 28 + 1 /* pad */ + size - 4);
 555         } else {
 556                 cli_setup_bcc(cli, p+size);
 557         }
 558
 559         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 560
 561         show_msg(cli->outbuf);
 562         if (direct_writes) {
 563                 /* For direct writes we now need to write the data
 564                  * directly out of buf. */
 565                 return cli_send_smb_direct_writeX(cli, buf, size);
 566         } else {
 567                 return cli_send_smb(cli);
 568         }
 569 }
 570
 571 /****************************************************************************
 572   write to a file
 573   write_mode: 0x0001 disallow write cacheing
 574               0x0002 return bytes remaining
 575               0x0004 use raw named pipe protocol
 576               0x0008 start of message mode named pipe protocol
 577 ****************************************************************************/
 578
 579 ssize_t cli_write(struct cli_state *cli,
 580                  int fnum, uint16 write_mode,
 581                  const char *buf, off_t offset, size_t size)
 582 {
 583         ssize_t bwritten = 0;
 584         unsigned int issued = 0;
 585         unsigned int received = 0;
 586         int mpx = 1;
 587         size_t writesize;
 588         int blocks;
 589
 590         if(cli->max_mux > 1) {
 591                 mpx = cli->max_mux-1;
 592         } else {
 593                 mpx = 1;
 594         }
 595
 596         /* Default (small) writesize. */
 597         writesize = (cli->max_xmit - (smb_size+32)) & ~1023;
 598
 599         if (write_mode == 0 &&
 600                         !client_is_signing_on(cli) &&
 601                         !cli_encryption_on(cli) &&
 602                         (cli->posix_capabilities & CIFS_UNIX_LARGE_WRITE_CAP) &&
 603                         (cli->capabilities & CAP_LARGE_FILES)) {
 604                 /* Only do massive writes if we can do them direct
 605                  * with no signing or encrypting - not on a pipe. */
 606                 writesize = CLI_SAMBA_MAX_POSIX_LARGE_WRITEX_SIZE;
 607         } else if ((cli->capabilities & CAP_LARGE_WRITEX) &&
 608                         (strcmp(cli->dev, "LPT1:") != 0)) {
 609
 610                 /* Printer devices are restricted to max_xmit
 611                  * writesize in Vista and XPSP3. */
 612
 613                 if (cli->is_samba) {
 614                         writesize = CLI_SAMBA_MAX_LARGE_WRITEX_SIZE;
 615                 } else if (!client_is_signing_on(cli)) {
 616                         /* Windows restricts signed writes to max_xmit.
 617                          * Found by Volker. */
 618                         writesize = CLI_WINDOWS_MAX_LARGE_WRITEX_SIZE;
 619                 }
 620         }
 621
 622         blocks = (size + (writesize-1)) / writesize;
 623
 624         while (received < blocks) {
 625
 626                 while ((issued - received < mpx) && (issued < blocks)) {
 627                         ssize_t bsent = issued * writesize;
 628                         ssize_t size1 = MIN(writesize, size - bsent);
 629
 630                         if (!cli_issue_write(cli, fnum, offset + bsent,
 631                                         write_mode,
 632                                         buf + bsent,
 633                                         size1, issued))
 634                                 return -1;
 635                         issued++;
 636                 }
 637
 638                 if (!cli_receive_smb(cli)) {
 639                         return bwritten;
 640                 }
 641
 642                 received++;
 643
 644                 if (cli_is_error(cli))
 645                         break;
 646
 647                 bwritten += SVAL(cli->inbuf, smb_vwv2);
 648                 if (writesize > 0xFFFF) {
 649                         bwritten += (((int)(SVAL(cli->inbuf, smb_vwv4)))<<16);
 650                 }
 651         }
 652
 653         while (received < issued && cli_receive_smb(cli)) {
 654                 received++;
 655         }
 656
 657         return bwritten;
 658 }
 659
 660 /****************************************************************************
 661   write to a file using a SMBwrite and not bypassing 0 byte writes
 662 ****************************************************************************/
 663
 664 ssize_t cli_smbwrite(struct cli_state *cli,
 665                      int fnum, char *buf, off_t offset, size_t size1)
 666 {
 667         char *p;
 668         ssize_t total = 0;
 669
 670         do {
 671                 size_t size = MIN(size1, cli->max_xmit - 48);
 672
 673                 memset(cli->outbuf,'\0',smb_size);
 674                 memset(cli->inbuf,'\0',smb_size);
 675
 676                 cli_set_message(cli->outbuf,5, 0,True);
 677
 678                 SCVAL(cli->outbuf,smb_com,SMBwrite);
 679                 SSVAL(cli->outbuf,smb_tid,cli->cnum);
 680                 cli_setup_packet(cli);
 681
 682                 SSVAL(cli->outbuf,smb_vwv0,fnum);
 683                 SSVAL(cli->outbuf,smb_vwv1,size);
 684                 SIVAL(cli->outbuf,smb_vwv2,offset);
 685                 SSVAL(cli->outbuf,smb_vwv4,0);
 686
 687                 p = smb_buf(cli->outbuf);
 688                 *p++ = 1;
 689                 SSVAL(p, 0, size); p += 2;
 690                 memcpy(p, buf + total, size); p += size;
 691
 692                 cli_setup_bcc(cli, p);
 693
 694                 if (!cli_send_smb(cli))
 695                         return -1;
 696
 697                 if (!cli_receive_smb(cli))
 698                         return -1;
 699
 700                 if (cli_is_error(cli))
 701                         return -1;
 702
 703                 size = SVAL(cli->inbuf,smb_vwv0);
 704                 if (size == 0)
 705                         break;
 706
 707                 size1 -= size;
 708                 total += size;
 709                 offset += size;
 710
 711         } while (size1);
 712
 713         return total;
 714 }