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         if (wct < 12) {
 142                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 143         }
 144
 145         /* size is the number of bytes the server returned.
 146          * Might be zero. */
 147         size = SVAL(cli_req->inbuf, smb_vwv5);
 148         size |= (((unsigned int)(SVAL(cli_req->inbuf, smb_vwv7))) << 16);
 149
 150         if (size > cli_req->data.read.size) {
 151                 DEBUG(5,("server returned more than we wanted!\n"));
 152                 return NT_STATUS_UNEXPECTED_IO_ERROR;
 153         }
 154
 155         *rcvbuf = (uint8_t *)
 156                 (smb_base(cli_req->inbuf) + SVAL(cli_req->inbuf, smb_vwv6));
 157         *received = size;
 158         return NT_STATUS_OK;
 159 }
 160
 161 /*
 162  * Parallel read support.
 163  *
 164  * cli_pull sends as many read&x requests as the server would allow via
 165  * max_mux at a time. When replies flow back in, the data is written into
 166  * the callback function "sink" in the right order.
 167  */
 168
 169 struct cli_pull_state {
 170         struct async_req *req;
 171
 172         struct cli_state *cli;
 173         uint16_t fnum;
 174         off_t start_offset;
 175         SMB_OFF_T size;
 176
 177         NTSTATUS (*sink)(char *buf, size_t n, void *priv);
 178         void *priv;
 179
 180         size_t chunk_size;
 181
 182         /*
 183          * Outstanding requests
 184          */
 185         int num_reqs;
 186         struct async_req **reqs;
 187
 188         /*
 189          * For how many bytes did we send requests already?
 190          */
 191         SMB_OFF_T requested;
 192
 193         /*
 194          * Next request index to push into "sink". This walks around the "req"
 195          * array, taking care that the requests are pushed to "sink" in the
 196          * right order. If necessary (i.e. replies don't come in in the right
 197          * order), replies are held back in "reqs".
 198          */
 199         int top_req;
 200
 201         /*
 202          * How many bytes did we push into "sink"?
 203          */
 204
 205         SMB_OFF_T pushed;
 206 };
 207
 208 static char *cli_pull_print(TALLOC_CTX *mem_ctx, struct async_req *req)
 209 {
 210         struct cli_pull_state *state = talloc_get_type_abort(
 211                 req->private_data, struct cli_pull_state);
 212         char *result;
 213
 214         result = async_req_print(mem_ctx, req);
 215         if (result == NULL) {
 216                 return NULL;
 217         }
 218
 219         return talloc_asprintf_append_buffer(
 220                 result, "num_reqs=%d, top_req=%d",
 221                 state->num_reqs, state->top_req);
 222 }
 223
 224 static void cli_pull_read_done(struct async_req *read_req);
 225
 226 /*
 227  * Prepare an async pull request
 228  */
 229
 230 struct async_req *cli_pull_send(TALLOC_CTX *mem_ctx, struct cli_state *cli,
 231                                 uint16_t fnum, off_t start_offset,
 232                                 SMB_OFF_T size, size_t window_size,
 233                                 NTSTATUS (*sink)(char *buf, size_t n,
 234                                                  void *priv),
 235                                 void *priv)
 236 {
 237         struct async_req *result;
 238         struct cli_pull_state *state;
 239         int i;
 240
 241         result = async_req_new(mem_ctx, cli->event_ctx);
 242         if (result == NULL) {
 243                 goto failed;
 244         }
 245         state = talloc(result, struct cli_pull_state);
 246         if (state == NULL) {
 247                 goto failed;
 248         }
 249         result->private_data = state;
 250         result->print = cli_pull_print;
 251         state->req = result;
 252
 253         state->cli = cli;
 254         state->fnum = fnum;
 255         state->start_offset = start_offset;
 256         state->size = size;
 257         state->sink = sink;
 258         state->priv = priv;
 259
 260         state->pushed = 0;
 261         state->top_req = 0;
 262
 263         if (size == 0) {
 264                 if (!async_post_status(result, NT_STATUS_OK)) {
 265                         goto failed;
 266                 }
 267                 return result;
 268         }
 269
 270         state->chunk_size = cli_read_max_bufsize(cli);
 271
 272         state->num_reqs = MAX(window_size/state->chunk_size, 1);
 273         state->num_reqs = MIN(state->num_reqs, cli->max_mux);
 274
 275         state->reqs = TALLOC_ZERO_ARRAY(state, struct async_req *,
 276                                         state->num_reqs);
 277         if (state->reqs == NULL) {
 278                 goto failed;
 279         }
 280
 281         state->requested = 0;
 282
 283         for (i=0; i<state->num_reqs; i++) {
 284                 SMB_OFF_T size_left;
 285                 size_t request_thistime;
 286
 287                 if (state->requested >= size) {
 288                         state->num_reqs = i;
 289                         break;
 290                 }
 291
 292                 size_left = size - state->requested;
 293                 request_thistime = MIN(size_left, state->chunk_size);
 294
 295                 state->reqs[i] = cli_read_andx_send(
 296                         state->reqs, cli, fnum,
 297                         state->start_offset + state->requested,
 298                         request_thistime);
 299
 300                 if (state->reqs[i] == NULL) {
 301                         goto failed;
 302                 }
 303
 304                 state->reqs[i]->async.fn = cli_pull_read_done;
 305                 state->reqs[i]->async.priv = result;
 306
 307                 state->requested += request_thistime;
 308         }
 309         return result;
 310
 311 failed:
 312         TALLOC_FREE(result);
 313         return NULL;
 314 }
 315
 316 /*
 317  * Handle incoming read replies, push the data into sink and send out new
 318  * requests if necessary.
 319  */
 320
 321 static void cli_pull_read_done(struct async_req *read_req)
 322 {
 323         struct async_req *pull_req = talloc_get_type_abort(
 324                 read_req->async.priv, struct async_req);
 325         struct cli_pull_state *state = talloc_get_type_abort(
 326                 pull_req->private_data, struct cli_pull_state);
 327         struct cli_request *read_state = cli_request_get(read_req);
 328         NTSTATUS status;
 329
 330         status = cli_read_andx_recv(read_req, &read_state->data.read.received,
 331                                     &read_state->data.read.rcvbuf);
 332         if (!NT_STATUS_IS_OK(status)) {
 333                 async_req_error(state->req, status);
 334                 return;
 335         }
 336
 337         /*
 338          * This loop is the one to take care of out-of-order replies. All
 339          * pending requests are in state->reqs, state->reqs[top_req] is the
 340          * one that is to be pushed next. If however a request later than
 341          * top_req is replied to, then we can't push yet. If top_req is
 342          * replied to at a later point then, we need to push all the finished
 343          * requests.
 344          */
 345
 346         while (state->reqs[state->top_req] != NULL) {
 347                 struct cli_request *top_read;
 348
 349                 DEBUG(11, ("cli_pull_read_done: top_req = %d\n",
 350                            state->top_req));
 351
 352                 if (state->reqs[state->top_req]->state < ASYNC_REQ_DONE) {
 353                         DEBUG(11, ("cli_pull_read_done: top request not yet "
 354                                    "done\n"));
 355                         return;
 356                 }
 357
 358                 top_read = cli_request_get(state->reqs[state->top_req]);
 359
 360                 DEBUG(10, ("cli_pull_read_done: Pushing %d bytes, %d already "
 361                            "pushed\n", (int)top_read->data.read.received,
 362                            (int)state->pushed));
 363
 364                 status = state->sink((char *)top_read->data.read.rcvbuf,
 365                                      top_read->data.read.received,
 366                                      state->priv);
 367                 if (!NT_STATUS_IS_OK(status)) {
 368                         async_req_error(state->req, status);
 369                         return;
 370                 }
 371                 state->pushed += top_read->data.read.received;
 372
 373                 TALLOC_FREE(state->reqs[state->top_req]);
 374
 375                 if (state->requested < state->size) {
 376                         struct async_req *new_req;
 377                         SMB_OFF_T size_left;
 378                         size_t request_thistime;
 379
 380                         size_left = state->size - state->requested;
 381                         request_thistime = MIN(size_left, state->chunk_size);
 382
 383                         DEBUG(10, ("cli_pull_read_done: Requesting %d bytes "
 384                                    "at %d, position %d\n",
 385                                    (int)request_thistime,
 386                                    (int)(state->start_offset
 387                                          + state->requested),
 388                                    state->top_req));
 389
 390                         new_req = cli_read_andx_send(
 391                                 state->reqs, state->cli, state->fnum,
 392                                 state->start_offset + state->requested,
 393                                 request_thistime);
 394
 395                         if (async_req_nomem(new_req, state->req)) {
 396                                 return;
 397                         }
 398
 399                         new_req->async.fn = cli_pull_read_done;
 400                         new_req->async.priv = pull_req;
 401
 402                         state->reqs[state->top_req] = new_req;
 403                         state->requested += request_thistime;
 404                 }
 405
 406                 state->top_req = (state->top_req+1) % state->num_reqs;
 407         }
 408
 409         async_req_done(pull_req);
 410 }
 411
 412 NTSTATUS cli_pull_recv(struct async_req *req, SMB_OFF_T *received)
 413 {
 414         struct cli_pull_state *state = talloc_get_type_abort(
 415                 req->private_data, struct cli_pull_state);
 416
 417         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 418         if (req->state == ASYNC_REQ_ERROR) {
 419                 return req->status;
 420         }
 421         *received = state->pushed;
 422         return NT_STATUS_OK;
 423 }
 424
 425 NTSTATUS cli_pull(struct cli_state *cli, uint16_t fnum,
 426                   off_t start_offset, SMB_OFF_T size, size_t window_size,
 427                   NTSTATUS (*sink)(char *buf, size_t n, void *priv),
 428                   void *priv, SMB_OFF_T *received)
 429 {
 430         TALLOC_CTX *frame = talloc_stackframe();
 431         struct async_req *req;
 432         NTSTATUS result = NT_STATUS_NO_MEMORY;
 433
 434         if (cli_tmp_event_ctx(frame, cli) == NULL) {
 435                 goto nomem;
 436         }
 437
 438         req = cli_pull_send(frame, cli, fnum, start_offset, size, window_size,
 439                             sink, priv);
 440         if (req == NULL) {
 441                 goto nomem;
 442         }
 443
 444         while (req->state < ASYNC_REQ_DONE) {
 445                 event_loop_once(cli->event_ctx);
 446         }
 447
 448         result = cli_pull_recv(req, received);
 449  nomem:
 450         TALLOC_FREE(frame);
 451         return result;
 452 }
 453
 454 static NTSTATUS cli_read_sink(char *buf, size_t n, void *priv)
 455 {
 456         char **pbuf = (char **)priv;
 457         memcpy(*pbuf, buf, n);
 458         *pbuf += n;
 459         return NT_STATUS_OK;
 460 }
 461
 462 ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 463                  off_t offset, size_t size)
 464 {
 465         NTSTATUS status;
 466         SMB_OFF_T ret;
 467
 468         status = cli_pull(cli, fnum, offset, size, size,
 469                           cli_read_sink, &buf, &ret);
 470         if (!NT_STATUS_IS_OK(status)) {
 471                 cli_set_error(cli, status);
 472                 return -1;
 473         }
 474         return ret;
 475 }
 476
 477 /****************************************************************************
 478  Issue a single SMBwrite and don't wait for a reply.
 479 ****************************************************************************/
 480
 481 static bool cli_issue_write(struct cli_state *cli,
 482                                 int fnum,
 483                                 off_t offset,
 484                                 uint16 mode,
 485                                 const char *buf,
 486                                 size_t size,
 487                                 int i)
 488 {
 489         char *p;
 490         bool large_writex = false;
 491         /* We can only do direct writes if not signing and not encrypting. */
 492         bool direct_writes = !client_is_signing_on(cli) && !cli_encryption_on(cli);
 493
 494         if (!direct_writes && size + 1 > cli->bufsize) {
 495                 cli->outbuf = (char *)SMB_REALLOC(cli->outbuf, size + 1024);
 496                 if (!cli->outbuf) {
 497                         return False;
 498                 }
 499                 cli->inbuf = (char *)SMB_REALLOC(cli->inbuf, size + 1024);
 500                 if (cli->inbuf == NULL) {
 501                         SAFE_FREE(cli->outbuf);
 502                         return False;
 503                 }
 504                 cli->bufsize = size + 1024;
 505         }
 506
 507         memset(cli->outbuf,'\0',smb_size);
 508         memset(cli->inbuf,'\0',smb_size);
 509
 510         if (cli->capabilities & CAP_LARGE_FILES) {
 511                 large_writex = True;
 512         }
 513
 514         if (large_writex) {
 515                 cli_set_message(cli->outbuf,14,0,True);
 516         } else {
 517                 cli_set_message(cli->outbuf,12,0,True);
 518         }
 519
 520         SCVAL(cli->outbuf,smb_com,SMBwriteX);
 521         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 522         cli_setup_packet(cli);
 523
 524         SCVAL(cli->outbuf,smb_vwv0,0xFF);
 525         SSVAL(cli->outbuf,smb_vwv2,fnum);
 526
 527         SIVAL(cli->outbuf,smb_vwv3,offset);
 528         SIVAL(cli->outbuf,smb_vwv5,0);
 529         SSVAL(cli->outbuf,smb_vwv7,mode);
 530
 531         SSVAL(cli->outbuf,smb_vwv8,(mode & 0x0008) ? size : 0);
 532         /*
 533          * According to CIFS-TR-1p00, this following field should only
 534          * be set if CAP_LARGE_WRITEX is set. We should check this
 535          * locally. However, this check might already have been
 536          * done by our callers.
 537          */
 538         SSVAL(cli->outbuf,smb_vwv9,(size>>16));
 539         SSVAL(cli->outbuf,smb_vwv10,size);
 540         /* +1 is pad byte. */
 541         SSVAL(cli->outbuf,smb_vwv11,
 542               smb_buf(cli->outbuf) - smb_base(cli->outbuf) + 1);
 543
 544         if (large_writex) {
 545                 SIVAL(cli->outbuf,smb_vwv12,(((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
 546         }
 547
 548         p = smb_base(cli->outbuf) + SVAL(cli->outbuf,smb_vwv11) -1;
 549         *p++ = '\0'; /* pad byte. */
 550         if (!direct_writes) {
 551                 memcpy(p, buf, size);
 552         }
 553         if (size > 0x1FFFF) {
 554                 /* This is a POSIX 14 word large write. */
 555                 set_message_bcc(cli->outbuf, 0); /* Set bcc to zero. */
 556                 _smb_setlen_large(cli->outbuf,smb_size + 28 + 1 /* pad */ + size - 4);
 557         } else {
 558                 cli_setup_bcc(cli, p+size);
 559         }
 560
 561         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 562
 563         show_msg(cli->outbuf);
 564         if (direct_writes) {
 565                 /* For direct writes we now need to write the data
 566                  * directly out of buf. */
 567                 return cli_send_smb_direct_writeX(cli, buf, size);
 568         } else {
 569                 return cli_send_smb(cli);
 570         }
 571 }
 572
 573 /****************************************************************************
 574   write to a file
 575   write_mode: 0x0001 disallow write cacheing
 576               0x0002 return bytes remaining
 577               0x0004 use raw named pipe protocol
 578               0x0008 start of message mode named pipe protocol
 579 ****************************************************************************/
 580
 581 ssize_t cli_write(struct cli_state *cli,
 582                  int fnum, uint16 write_mode,
 583                  const char *buf, off_t offset, size_t size)
 584 {
 585         ssize_t bwritten = 0;
 586         unsigned int issued = 0;
 587         unsigned int received = 0;
 588         int mpx = 1;
 589         size_t writesize;
 590         int blocks;
 591
 592         if(cli->max_mux > 1) {
 593                 mpx = cli->max_mux-1;
 594         } else {
 595                 mpx = 1;
 596         }
 597
 598         /* Default (small) writesize. */
 599         writesize = (cli->max_xmit - (smb_size+32)) & ~1023;
 600
 601         if (write_mode == 0 &&
 602                         !client_is_signing_on(cli) &&
 603                         !cli_encryption_on(cli) &&
 604                         (cli->posix_capabilities & CIFS_UNIX_LARGE_WRITE_CAP) &&
 605                         (cli->capabilities & CAP_LARGE_FILES)) {
 606                 /* Only do massive writes if we can do them direct
 607                  * with no signing or encrypting - not on a pipe. */
 608                 writesize = CLI_SAMBA_MAX_POSIX_LARGE_WRITEX_SIZE;
 609         } else if ((cli->capabilities & CAP_LARGE_WRITEX) &&
 610                         (strcmp(cli->dev, "LPT1:") != 0)) {
 611
 612                 /* Printer devices are restricted to max_xmit
 613                  * writesize in Vista and XPSP3. */
 614
 615                 if (cli->is_samba) {
 616                         writesize = CLI_SAMBA_MAX_LARGE_WRITEX_SIZE;
 617                 } else if (!client_is_signing_on(cli)) {
 618                         /* Windows restricts signed writes to max_xmit.
 619                          * Found by Volker. */
 620                         writesize = CLI_WINDOWS_MAX_LARGE_WRITEX_SIZE;
 621                 }
 622         }
 623
 624         blocks = (size + (writesize-1)) / writesize;
 625
 626         while (received < blocks) {
 627
 628                 while ((issued - received < mpx) && (issued < blocks)) {
 629                         ssize_t bsent = issued * writesize;
 630                         ssize_t size1 = MIN(writesize, size - bsent);
 631
 632                         if (!cli_issue_write(cli, fnum, offset + bsent,
 633                                         write_mode,
 634                                         buf + bsent,
 635                                         size1, issued))
 636                                 return -1;
 637                         issued++;
 638                 }
 639
 640                 if (!cli_receive_smb(cli)) {
 641                         return bwritten;
 642                 }
 643
 644                 received++;
 645
 646                 if (cli_is_error(cli))
 647                         break;
 648
 649                 bwritten += SVAL(cli->inbuf, smb_vwv2);
 650                 if (writesize > 0xFFFF) {
 651                         bwritten += (((int)(SVAL(cli->inbuf, smb_vwv4)))<<16);
 652                 }
 653         }
 654
 655         while (received < issued && cli_receive_smb(cli)) {
 656                 received++;
 657         }
 658
 659         return bwritten;
 660 }
 661
 662 /****************************************************************************
 663   write to a file using a SMBwrite and not bypassing 0 byte writes
 664 ****************************************************************************/
 665
 666 ssize_t cli_smbwrite(struct cli_state *cli,
 667                      int fnum, char *buf, off_t offset, size_t size1)
 668 {
 669         char *p;
 670         ssize_t total = 0;
 671
 672         do {
 673                 size_t size = MIN(size1, cli->max_xmit - 48);
 674
 675                 memset(cli->outbuf,'\0',smb_size);
 676                 memset(cli->inbuf,'\0',smb_size);
 677
 678                 cli_set_message(cli->outbuf,5, 0,True);
 679
 680                 SCVAL(cli->outbuf,smb_com,SMBwrite);
 681                 SSVAL(cli->outbuf,smb_tid,cli->cnum);
 682                 cli_setup_packet(cli);
 683
 684                 SSVAL(cli->outbuf,smb_vwv0,fnum);
 685                 SSVAL(cli->outbuf,smb_vwv1,size);
 686                 SIVAL(cli->outbuf,smb_vwv2,offset);
 687                 SSVAL(cli->outbuf,smb_vwv4,0);
 688
 689                 p = smb_buf(cli->outbuf);
 690                 *p++ = 1;
 691                 SSVAL(p, 0, size); p += 2;
 692                 memcpy(p, buf + total, size); p += size;
 693
 694                 cli_setup_bcc(cli, p);
 695
 696                 if (!cli_send_smb(cli))
 697                         return -1;
 698
 699                 if (!cli_receive_smb(cli))
 700                         return -1;
 701
 702                 if (cli_is_error(cli))
 703                         return -1;
 704
 705                 size = SVAL(cli->inbuf,smb_vwv0);
 706                 if (size == 0)
 707                         break;
 708
 709                 size1 -= size;
 710                 total += size;
 711                 offset += size;
 712
 713         } while (size1);
 714
 715         return total;
 716 }