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 event_context *ev,
  45                                      struct cli_state *cli, int fnum,
  46                                      off_t offset, size_t size)
  47 {
  48         struct async_req *result;
  49         struct cli_request *req;
  50         bool bigoffset = False;
  51
  52         uint16_t vwv[12];
  53         uint8_t wct = 10;
  54
  55         if (size > cli_read_max_bufsize(cli)) {
  56                 DEBUG(0, ("cli_read_andx_send got size=%d, can only handle "
  57                           "size=%d\n", (int)size,
  58                           (int)cli_read_max_bufsize(cli)));
  59                 return NULL;
  60         }
  61
  62         SCVAL(vwv + 0, 0, 0xFF);
  63         SCVAL(vwv + 0, 1, 0);
  64         SSVAL(vwv + 1, 0, 0);
  65         SSVAL(vwv + 2, 0, fnum);
  66         SIVAL(vwv + 3, 0, offset);
  67         SSVAL(vwv + 5, 0, size);
  68         SSVAL(vwv + 6, 0, size);
  69         SSVAL(vwv + 7, 0, (size >> 16));
  70         SSVAL(vwv + 8, 0, 0);
  71         SSVAL(vwv + 9, 0, 0);
  72
  73         if ((uint64_t)offset >> 32) {
  74                 bigoffset = True;
  75                 SIVAL(vwv + 10, 0,
  76                       (((uint64_t)offset)>>32) & 0xffffffff);
  77                 wct += 2;
  78         }
  79
  80         result = cli_request_send(mem_ctx, ev, cli, SMBreadX, 0, wct, vwv,
  81                                   0, NULL);
  82         if (result == NULL) {
  83                 return NULL;
  84         }
  85
  86         req = talloc_get_type_abort(result->private_data, struct cli_request);
  87
  88         req->data.read.ofs = offset;
  89         req->data.read.size = size;
  90         req->data.read.received = 0;
  91         req->data.read.rcvbuf = NULL;
  92
  93         return result;
  94 }
  95
  96 /*
  97  * Pull the data out of a finished async read_and_x request. rcvbuf is
  98  * talloced from the request, so better make sure that you copy it away before
  99  * you talloc_free(req). "rcvbuf" is NOT a talloc_ctx of its own, so do not
 100  * talloc_move it!
 101  */
 102
 103 NTSTATUS cli_read_andx_recv(struct async_req *req, ssize_t *received,
 104                             uint8_t **rcvbuf)
 105 {
 106         struct cli_request *cli_req = talloc_get_type_abort(
 107                 req->private_data, struct cli_request);
 108         uint8_t wct;
 109         uint16_t *vwv;
 110         uint16_t num_bytes;
 111         uint8_t *bytes;
 112         NTSTATUS status;
 113         size_t size;
 114
 115         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 116         if (req->state == ASYNC_REQ_ERROR) {
 117                 return req->status;
 118         }
 119
 120         status = cli_pull_reply(req, &wct, &vwv, &num_bytes, &bytes);
 121
 122         if (NT_STATUS_IS_ERR(status)) {
 123                 return status;
 124         }
 125
 126         if (wct < 12) {
 127                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 128         }
 129
 130         /* size is the number of bytes the server returned.
 131          * Might be zero. */
 132         size = SVAL(vwv + 5, 0);
 133         size |= (((unsigned int)SVAL(vwv + 7, 0)) << 16);
 134
 135         if (size > cli_req->data.read.size) {
 136                 DEBUG(5,("server returned more than we wanted!\n"));
 137                 return NT_STATUS_UNEXPECTED_IO_ERROR;
 138         }
 139
 140         *rcvbuf = (uint8_t *)(smb_base(cli_req->inbuf) + SVAL(vwv + 6, 0));
 141         *received = size;
 142         return NT_STATUS_OK;
 143 }
 144
 145 /*
 146  * Parallel read support.
 147  *
 148  * cli_pull sends as many read&x requests as the server would allow via
 149  * max_mux at a time. When replies flow back in, the data is written into
 150  * the callback function "sink" in the right order.
 151  */
 152
 153 struct cli_pull_state {
 154         struct async_req *req;
 155
 156         struct event_context *ev;
 157         struct cli_state *cli;
 158         uint16_t fnum;
 159         off_t start_offset;
 160         SMB_OFF_T size;
 161
 162         NTSTATUS (*sink)(char *buf, size_t n, void *priv);
 163         void *priv;
 164
 165         size_t chunk_size;
 166
 167         /*
 168          * Outstanding requests
 169          */
 170         int num_reqs;
 171         struct async_req **reqs;
 172
 173         /*
 174          * For how many bytes did we send requests already?
 175          */
 176         SMB_OFF_T requested;
 177
 178         /*
 179          * Next request index to push into "sink". This walks around the "req"
 180          * array, taking care that the requests are pushed to "sink" in the
 181          * right order. If necessary (i.e. replies don't come in in the right
 182          * order), replies are held back in "reqs".
 183          */
 184         int top_req;
 185
 186         /*
 187          * How many bytes did we push into "sink"?
 188          */
 189
 190         SMB_OFF_T pushed;
 191 };
 192
 193 static char *cli_pull_print(TALLOC_CTX *mem_ctx, struct async_req *req)
 194 {
 195         struct cli_pull_state *state = talloc_get_type_abort(
 196                 req->private_data, struct cli_pull_state);
 197         char *result;
 198
 199         result = async_req_print(mem_ctx, req);
 200         if (result == NULL) {
 201                 return NULL;
 202         }
 203
 204         return talloc_asprintf_append_buffer(
 205                 result, "num_reqs=%d, top_req=%d",
 206                 state->num_reqs, state->top_req);
 207 }
 208
 209 static void cli_pull_read_done(struct async_req *read_req);
 210
 211 /*
 212  * Prepare an async pull request
 213  */
 214
 215 struct async_req *cli_pull_send(TALLOC_CTX *mem_ctx,
 216                                 struct event_context *ev,
 217                                 struct cli_state *cli,
 218                                 uint16_t fnum, off_t start_offset,
 219                                 SMB_OFF_T size, size_t window_size,
 220                                 NTSTATUS (*sink)(char *buf, size_t n,
 221                                                  void *priv),
 222                                 void *priv)
 223 {
 224         struct async_req *result;
 225         struct cli_pull_state *state;
 226         int i;
 227
 228         result = async_req_new(mem_ctx, ev);
 229         if (result == NULL) {
 230                 goto failed;
 231         }
 232         state = talloc(result, struct cli_pull_state);
 233         if (state == NULL) {
 234                 goto failed;
 235         }
 236         result->private_data = state;
 237         result->print = cli_pull_print;
 238         state->req = result;
 239
 240         state->cli = cli;
 241         state->ev = ev;
 242         state->fnum = fnum;
 243         state->start_offset = start_offset;
 244         state->size = size;
 245         state->sink = sink;
 246         state->priv = priv;
 247
 248         state->pushed = 0;
 249         state->top_req = 0;
 250
 251         if (size == 0) {
 252                 if (!async_post_status(result, NT_STATUS_OK)) {
 253                         goto failed;
 254                 }
 255                 return result;
 256         }
 257
 258         state->chunk_size = cli_read_max_bufsize(cli);
 259
 260         state->num_reqs = MAX(window_size/state->chunk_size, 1);
 261         state->num_reqs = MIN(state->num_reqs, cli->max_mux);
 262
 263         state->reqs = TALLOC_ZERO_ARRAY(state, struct async_req *,
 264                                         state->num_reqs);
 265         if (state->reqs == NULL) {
 266                 goto failed;
 267         }
 268
 269         state->requested = 0;
 270
 271         for (i=0; i<state->num_reqs; i++) {
 272                 SMB_OFF_T size_left;
 273                 size_t request_thistime;
 274
 275                 if (state->requested >= size) {
 276                         state->num_reqs = i;
 277                         break;
 278                 }
 279
 280                 size_left = size - state->requested;
 281                 request_thistime = MIN(size_left, state->chunk_size);
 282
 283                 state->reqs[i] = cli_read_andx_send(
 284                         state->reqs, ev, cli, fnum,
 285                         state->start_offset + state->requested,
 286                         request_thistime);
 287
 288                 if (state->reqs[i] == NULL) {
 289                         goto failed;
 290                 }
 291
 292                 state->reqs[i]->async.fn = cli_pull_read_done;
 293                 state->reqs[i]->async.priv = result;
 294
 295                 state->requested += request_thistime;
 296         }
 297         return result;
 298
 299 failed:
 300         TALLOC_FREE(result);
 301         return NULL;
 302 }
 303
 304 /*
 305  * Handle incoming read replies, push the data into sink and send out new
 306  * requests if necessary.
 307  */
 308
 309 static void cli_pull_read_done(struct async_req *read_req)
 310 {
 311         struct async_req *pull_req = talloc_get_type_abort(
 312                 read_req->async.priv, struct async_req);
 313         struct cli_pull_state *state = talloc_get_type_abort(
 314                 pull_req->private_data, struct cli_pull_state);
 315         struct cli_request *read_state = talloc_get_type_abort(
 316                 read_req->private_data, struct cli_request);
 317         NTSTATUS status;
 318
 319         status = cli_read_andx_recv(read_req, &read_state->data.read.received,
 320                                     &read_state->data.read.rcvbuf);
 321         if (!NT_STATUS_IS_OK(status)) {
 322                 async_req_error(state->req, status);
 323                 return;
 324         }
 325
 326         /*
 327          * This loop is the one to take care of out-of-order replies. All
 328          * pending requests are in state->reqs, state->reqs[top_req] is the
 329          * one that is to be pushed next. If however a request later than
 330          * top_req is replied to, then we can't push yet. If top_req is
 331          * replied to at a later point then, we need to push all the finished
 332          * requests.
 333          */
 334
 335         while (state->reqs[state->top_req] != NULL) {
 336                 struct cli_request *top_read;
 337
 338                 DEBUG(11, ("cli_pull_read_done: top_req = %d\n",
 339                            state->top_req));
 340
 341                 if (state->reqs[state->top_req]->state < ASYNC_REQ_DONE) {
 342                         DEBUG(11, ("cli_pull_read_done: top request not yet "
 343                                    "done\n"));
 344                         return;
 345                 }
 346
 347                 top_read = talloc_get_type_abort(
 348                         state->reqs[state->top_req]->private_data,
 349                         struct cli_request);
 350
 351                 DEBUG(10, ("cli_pull_read_done: Pushing %d bytes, %d already "
 352                            "pushed\n", (int)top_read->data.read.received,
 353                            (int)state->pushed));
 354
 355                 status = state->sink((char *)top_read->data.read.rcvbuf,
 356                                      top_read->data.read.received,
 357                                      state->priv);
 358                 if (!NT_STATUS_IS_OK(status)) {
 359                         async_req_error(state->req, status);
 360                         return;
 361                 }
 362                 state->pushed += top_read->data.read.received;
 363
 364                 TALLOC_FREE(state->reqs[state->top_req]);
 365
 366                 if (state->requested < state->size) {
 367                         struct async_req *new_req;
 368                         SMB_OFF_T size_left;
 369                         size_t request_thistime;
 370
 371                         size_left = state->size - state->requested;
 372                         request_thistime = MIN(size_left, state->chunk_size);
 373
 374                         DEBUG(10, ("cli_pull_read_done: Requesting %d bytes "
 375                                    "at %d, position %d\n",
 376                                    (int)request_thistime,
 377                                    (int)(state->start_offset
 378                                          + state->requested),
 379                                    state->top_req));
 380
 381                         new_req = cli_read_andx_send(
 382                                 state->reqs, state->ev, state->cli,
 383                                 state->fnum,
 384                                 state->start_offset + state->requested,
 385                                 request_thistime);
 386
 387                         if (async_req_nomem(new_req, state->req)) {
 388                                 return;
 389                         }
 390
 391                         new_req->async.fn = cli_pull_read_done;
 392                         new_req->async.priv = pull_req;
 393
 394                         state->reqs[state->top_req] = new_req;
 395                         state->requested += request_thistime;
 396                 }
 397
 398                 state->top_req = (state->top_req+1) % state->num_reqs;
 399         }
 400
 401         async_req_done(pull_req);
 402 }
 403
 404 NTSTATUS cli_pull_recv(struct async_req *req, SMB_OFF_T *received)
 405 {
 406         struct cli_pull_state *state = talloc_get_type_abort(
 407                 req->private_data, struct cli_pull_state);
 408
 409         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 410         if (req->state == ASYNC_REQ_ERROR) {
 411                 return req->status;
 412         }
 413         *received = state->pushed;
 414         return NT_STATUS_OK;
 415 }
 416
 417 NTSTATUS cli_pull(struct cli_state *cli, uint16_t fnum,
 418                   off_t start_offset, SMB_OFF_T size, size_t window_size,
 419                   NTSTATUS (*sink)(char *buf, size_t n, void *priv),
 420                   void *priv, SMB_OFF_T *received)
 421 {
 422         TALLOC_CTX *frame = talloc_stackframe();
 423         struct event_context *ev;
 424         struct async_req *req;
 425         NTSTATUS result = NT_STATUS_NO_MEMORY;
 426
 427         if (cli->fd_event != NULL) {
 428                 /*
 429                  * Can't use sync call while an async call is in flight
 430                  */
 431                 return NT_STATUS_INVALID_PARAMETER;
 432         }
 433
 434         ev = event_context_init(frame);
 435         if (ev == NULL) {
 436                 goto nomem;
 437         }
 438
 439         req = cli_pull_send(frame, ev, cli, fnum, start_offset, size,
 440                             window_size, sink, priv);
 441         if (req == NULL) {
 442                 goto nomem;
 443         }
 444
 445         while (req->state < ASYNC_REQ_DONE) {
 446                 event_loop_once(ev);
 447         }
 448
 449         result = cli_pull_recv(req, received);
 450  nomem:
 451         TALLOC_FREE(frame);
 452         return result;
 453 }
 454
 455 static NTSTATUS cli_read_sink(char *buf, size_t n, void *priv)
 456 {
 457         char **pbuf = (char **)priv;
 458         memcpy(*pbuf, buf, n);
 459         *pbuf += n;
 460         return NT_STATUS_OK;
 461 }
 462
 463 ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 464                  off_t offset, size_t size)
 465 {
 466         NTSTATUS status;
 467         SMB_OFF_T ret;
 468
 469         status = cli_pull(cli, fnum, offset, size, size,
 470                           cli_read_sink, &buf, &ret);
 471         if (!NT_STATUS_IS_OK(status)) {
 472                 cli_set_error(cli, status);
 473                 return -1;
 474         }
 475         return ret;
 476 }
 477
 478 /****************************************************************************
 479  Issue a single SMBwrite and don't wait for a reply.
 480 ****************************************************************************/
 481
 482 static bool cli_issue_write(struct cli_state *cli,
 483                                 int fnum,
 484                                 off_t offset,
 485                                 uint16 mode,
 486                                 const char *buf,
 487                                 size_t size,
 488                                 int i)
 489 {
 490         char *p;
 491         bool large_writex = false;
 492         /* We can only do direct writes if not signing and not encrypting. */
 493         bool direct_writes = !client_is_signing_on(cli) && !cli_encryption_on(cli);
 494
 495         if (!direct_writes && size + 1 > cli->bufsize) {
 496                 cli->outbuf = (char *)SMB_REALLOC(cli->outbuf, size + 1024);
 497                 if (!cli->outbuf) {
 498                         return False;
 499                 }
 500                 cli->inbuf = (char *)SMB_REALLOC(cli->inbuf, size + 1024);
 501                 if (cli->inbuf == NULL) {
 502                         SAFE_FREE(cli->outbuf);
 503                         return False;
 504                 }
 505                 cli->bufsize = size + 1024;
 506         }
 507
 508         memset(cli->outbuf,'\0',smb_size);
 509         memset(cli->inbuf,'\0',smb_size);
 510
 511         if (cli->capabilities & CAP_LARGE_FILES) {
 512                 large_writex = True;
 513         }
 514
 515         if (large_writex) {
 516                 cli_set_message(cli->outbuf,14,0,True);
 517         } else {
 518                 cli_set_message(cli->outbuf,12,0,True);
 519         }
 520
 521         SCVAL(cli->outbuf,smb_com,SMBwriteX);
 522         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 523         cli_setup_packet(cli);
 524
 525         SCVAL(cli->outbuf,smb_vwv0,0xFF);
 526         SSVAL(cli->outbuf,smb_vwv2,fnum);
 527
 528         SIVAL(cli->outbuf,smb_vwv3,offset);
 529         SIVAL(cli->outbuf,smb_vwv5,0);
 530         SSVAL(cli->outbuf,smb_vwv7,mode);
 531
 532         SSVAL(cli->outbuf,smb_vwv8,(mode & 0x0008) ? size : 0);
 533         /*
 534          * According to CIFS-TR-1p00, this following field should only
 535          * be set if CAP_LARGE_WRITEX is set. We should check this
 536          * locally. However, this check might already have been
 537          * done by our callers.
 538          */
 539         SSVAL(cli->outbuf,smb_vwv9,(size>>16));
 540         SSVAL(cli->outbuf,smb_vwv10,size);
 541         /* +1 is pad byte. */
 542         SSVAL(cli->outbuf,smb_vwv11,
 543               smb_buf(cli->outbuf) - smb_base(cli->outbuf) + 1);
 544
 545         if (large_writex) {
 546                 SIVAL(cli->outbuf,smb_vwv12,(((uint64_t)offset)>>32) & 0xffffffff);
 547         }
 548
 549         p = smb_base(cli->outbuf) + SVAL(cli->outbuf,smb_vwv11) -1;
 550         *p++ = '\0'; /* pad byte. */
 551         if (!direct_writes) {
 552                 memcpy(p, buf, size);
 553         }
 554         if (size > 0x1FFFF) {
 555                 /* This is a POSIX 14 word large write. */
 556                 set_message_bcc(cli->outbuf, 0); /* Set bcc to zero. */
 557                 _smb_setlen_large(cli->outbuf,smb_size + 28 + 1 /* pad */ + size - 4);
 558         } else {
 559                 cli_setup_bcc(cli, p+size);
 560         }
 561
 562         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 563
 564         show_msg(cli->outbuf);
 565         if (direct_writes) {
 566                 /* For direct writes we now need to write the data
 567                  * directly out of buf. */
 568                 return cli_send_smb_direct_writeX(cli, buf, size);
 569         } else {
 570                 return cli_send_smb(cli);
 571         }
 572 }
 573
 574 /****************************************************************************
 575   write to a file
 576   write_mode: 0x0001 disallow write cacheing
 577               0x0002 return bytes remaining
 578               0x0004 use raw named pipe protocol
 579               0x0008 start of message mode named pipe protocol
 580 ****************************************************************************/
 581
 582 ssize_t cli_write(struct cli_state *cli,
 583                  int fnum, uint16 write_mode,
 584                  const char *buf, off_t offset, size_t size)
 585 {
 586         ssize_t bwritten = 0;
 587         unsigned int issued = 0;
 588         unsigned int received = 0;
 589         int mpx = 1;
 590         size_t writesize;
 591         int blocks;
 592
 593         if(cli->max_mux > 1) {
 594                 mpx = cli->max_mux-1;
 595         } else {
 596                 mpx = 1;
 597         }
 598
 599         /* Default (small) writesize. */
 600         writesize = (cli->max_xmit - (smb_size+32)) & ~1023;
 601
 602         if (write_mode == 0 &&
 603                         !client_is_signing_on(cli) &&
 604                         !cli_encryption_on(cli) &&
 605                         (cli->posix_capabilities & CIFS_UNIX_LARGE_WRITE_CAP) &&
 606                         (cli->capabilities & CAP_LARGE_FILES)) {
 607                 /* Only do massive writes if we can do them direct
 608                  * with no signing or encrypting - not on a pipe. */
 609                 writesize = CLI_SAMBA_MAX_POSIX_LARGE_WRITEX_SIZE;
 610         } else if ((cli->capabilities & CAP_LARGE_WRITEX) &&
 611                         (strcmp(cli->dev, "LPT1:") != 0)) {
 612
 613                 /* Printer devices are restricted to max_xmit
 614                  * writesize in Vista and XPSP3. */
 615
 616                 if (cli->is_samba) {
 617                         writesize = CLI_SAMBA_MAX_LARGE_WRITEX_SIZE;
 618                 } else if (!client_is_signing_on(cli)) {
 619                         /* Windows restricts signed writes to max_xmit.
 620                          * Found by Volker. */
 621                         writesize = CLI_WINDOWS_MAX_LARGE_WRITEX_SIZE;
 622                 }
 623         }
 624
 625         blocks = (size + (writesize-1)) / writesize;
 626
 627         while (received < blocks) {
 628
 629                 while ((issued - received < mpx) && (issued < blocks)) {
 630                         ssize_t bsent = issued * writesize;
 631                         ssize_t size1 = MIN(writesize, size - bsent);
 632
 633                         if (!cli_issue_write(cli, fnum, offset + bsent,
 634                                         write_mode,
 635                                         buf + bsent,
 636                                         size1, issued))
 637                                 return -1;
 638                         issued++;
 639                 }
 640
 641                 if (!cli_receive_smb(cli)) {
 642                         return bwritten;
 643                 }
 644
 645                 received++;
 646
 647                 if (cli_is_error(cli))
 648                         break;
 649
 650                 bwritten += SVAL(cli->inbuf, smb_vwv2);
 651                 if (writesize > 0xFFFF) {
 652                         bwritten += (((int)(SVAL(cli->inbuf, smb_vwv4)))<<16);
 653                 }
 654         }
 655
 656         while (received < issued && cli_receive_smb(cli)) {
 657                 received++;
 658         }
 659
 660         return bwritten;
 661 }
 662
 663 /****************************************************************************
 664   write to a file using a SMBwrite and not bypassing 0 byte writes
 665 ****************************************************************************/
 666
 667 ssize_t cli_smbwrite(struct cli_state *cli,
 668                      int fnum, char *buf, off_t offset, size_t size1)
 669 {
 670         char *p;
 671         ssize_t total = 0;
 672
 673         do {
 674                 size_t size = MIN(size1, cli->max_xmit - 48);
 675
 676                 memset(cli->outbuf,'\0',smb_size);
 677                 memset(cli->inbuf,'\0',smb_size);
 678
 679                 cli_set_message(cli->outbuf,5, 0,True);
 680
 681                 SCVAL(cli->outbuf,smb_com,SMBwrite);
 682                 SSVAL(cli->outbuf,smb_tid,cli->cnum);
 683                 cli_setup_packet(cli);
 684
 685                 SSVAL(cli->outbuf,smb_vwv0,fnum);
 686                 SSVAL(cli->outbuf,smb_vwv1,size);
 687                 SIVAL(cli->outbuf,smb_vwv2,offset);
 688                 SSVAL(cli->outbuf,smb_vwv4,0);
 689
 690                 p = smb_buf(cli->outbuf);
 691                 *p++ = 1;
 692                 SSVAL(p, 0, size); p += 2;
 693                 memcpy(p, buf + total, size); p += size;
 694
 695                 cli_setup_bcc(cli, p);
 696
 697                 if (!cli_send_smb(cli))
 698                         return -1;
 699
 700                 if (!cli_receive_smb(cli))
 701                         return -1;
 702
 703                 if (cli_is_error(cli))
 704                         return -1;
 705
 706                 size = SVAL(cli->inbuf,smb_vwv0);
 707                 if (size == 0)
 708                         break;
 709
 710                 size1 -= size;
 711                 total += size;
 712                 offset += size;
 713
 714         } while (size1);
 715
 716         return total;
 717 }