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