source/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         if (size < 0) {
 154                 DEBUG(5,("read return < 0!\n"));
 155                 return NT_STATUS_UNEXPECTED_IO_ERROR;
 156         }
 157
 158         *rcvbuf = (uint8_t *)
 159                 (smb_base(cli_req->inbuf) + SVAL(cli_req->inbuf, smb_vwv6));
 160         *received = size;
 161         return NT_STATUS_OK;
 162 }
 163
 164 /*
 165  * Parallel read support.
 166  *
 167  * cli_pull sends as many read&x requests as the server would allow via
 168  * max_mux at a time. When replies flow back in, the data is written into
 169  * the callback function "sink" in the right order.
 170  */
 171
 172 struct cli_pull_state {
 173         struct async_req *req;
 174
 175         struct cli_state *cli;
 176         uint16_t fnum;
 177         off_t start_offset;
 178         SMB_OFF_T size;
 179
 180         NTSTATUS (*sink)(char *buf, size_t n, void *priv);
 181         void *priv;
 182
 183         size_t chunk_size;
 184
 185         /*
 186          * Outstanding requests
 187          */
 188         int num_reqs;
 189         struct async_req **reqs;
 190
 191         /*
 192          * For how many bytes did we send requests already?
 193          */
 194         SMB_OFF_T requested;
 195
 196         /*
 197          * Next request index to push into "sink". This walks around the "req"
 198          * array, taking care that the requests are pushed to "sink" in the
 199          * right order. If necessary (i.e. replies don't come in in the right
 200          * order), replies are held back in "reqs".
 201          */
 202         int top_req;
 203
 204         /*
 205          * How many bytes did we push into "sink"?
 206          */
 207
 208         SMB_OFF_T pushed;
 209 };
 210
 211 static char *cli_pull_print(TALLOC_CTX *mem_ctx, struct async_req *req)
 212 {
 213         struct cli_pull_state *state = talloc_get_type_abort(
 214                 req->private_data, struct cli_pull_state);
 215         char *result;
 216
 217         result = async_req_print(mem_ctx, req);
 218         if (result == NULL) {
 219                 return NULL;
 220         }
 221
 222         return talloc_asprintf_append_buffer(
 223                 result, "num_reqs=%d, top_req=%d",
 224                 state->num_reqs, state->top_req);
 225 }
 226
 227 static void cli_pull_read_done(struct async_req *read_req);
 228
 229 /*
 230  * Prepare an async pull request
 231  */
 232
 233 struct async_req *cli_pull_send(TALLOC_CTX *mem_ctx, struct cli_state *cli,
 234                                 uint16_t fnum, off_t start_offset,
 235                                 SMB_OFF_T size, size_t window_size,
 236                                 NTSTATUS (*sink)(char *buf, size_t n,
 237                                                  void *priv),
 238                                 void *priv)
 239 {
 240         struct async_req *result;
 241         struct cli_pull_state *state;
 242         int i;
 243
 244         result = async_req_new(mem_ctx, cli->event_ctx);
 245         if (result == NULL) {
 246                 goto failed;
 247         }
 248         state = talloc(result, struct cli_pull_state);
 249         if (state == NULL) {
 250                 goto failed;
 251         }
 252         result->private_data = state;
 253         result->print = cli_pull_print;
 254         state->req = result;
 255
 256         state->cli = cli;
 257         state->fnum = fnum;
 258         state->start_offset = start_offset;
 259         state->size = size;
 260         state->sink = sink;
 261         state->priv = priv;
 262
 263         state->pushed = 0;
 264         state->top_req = 0;
 265
 266         if (size == 0) {
 267                 if (!async_post_status(result, NT_STATUS_OK)) {
 268                         goto failed;
 269                 }
 270                 return result;
 271         }
 272
 273         state->chunk_size = cli_read_max_bufsize(cli);
 274
 275         state->num_reqs = MAX(window_size/state->chunk_size, 1);
 276         state->num_reqs = MIN(state->num_reqs, cli->max_mux);
 277
 278         state->reqs = TALLOC_ZERO_ARRAY(state, struct async_req *,
 279                                         state->num_reqs);
 280         if (state->reqs == NULL) {
 281                 goto failed;
 282         }
 283
 284         state->requested = 0;
 285
 286         for (i=0; i<state->num_reqs; i++) {
 287                 SMB_OFF_T size_left;
 288                 size_t request_thistime;
 289
 290                 if (state->requested >= size) {
 291                         state->num_reqs = i;
 292                         break;
 293                 }
 294
 295                 size_left = size - state->requested;
 296                 request_thistime = MIN(size_left, state->chunk_size);
 297
 298                 state->reqs[i] = cli_read_andx_send(
 299                         state->reqs, cli, fnum,
 300                         state->start_offset + state->requested,
 301                         request_thistime);
 302
 303                 if (state->reqs[i] == NULL) {
 304                         goto failed;
 305                 }
 306
 307                 state->reqs[i]->async.fn = cli_pull_read_done;
 308                 state->reqs[i]->async.priv = result;
 309
 310                 state->requested += request_thistime;
 311         }
 312         return result;
 313
 314 failed:
 315         TALLOC_FREE(result);
 316         return NULL;
 317 }
 318
 319 /*
 320  * Handle incoming read replies, push the data into sink and send out new
 321  * requests if necessary.
 322  */
 323
 324 static void cli_pull_read_done(struct async_req *read_req)
 325 {
 326         struct async_req *pull_req = talloc_get_type_abort(
 327                 read_req->async.priv, struct async_req);
 328         struct cli_pull_state *state = talloc_get_type_abort(
 329                 pull_req->private_data, struct cli_pull_state);
 330         struct cli_request *read_state = cli_request_get(read_req);
 331         NTSTATUS status;
 332
 333         status = cli_read_andx_recv(read_req, &read_state->data.read.received,
 334                                     &read_state->data.read.rcvbuf);
 335         if (!NT_STATUS_IS_OK(status)) {
 336                 async_req_error(state->req, status);
 337                 return;
 338         }
 339
 340         /*
 341          * This loop is the one to take care of out-of-order replies. All
 342          * pending requests are in state->reqs, state->reqs[top_req] is the
 343          * one that is to be pushed next. If however a request later than
 344          * top_req is replied to, then we can't push yet. If top_req is
 345          * replied to at a later point then, we need to push all the finished
 346          * requests.
 347          */
 348
 349         while (state->reqs[state->top_req] != NULL) {
 350                 struct cli_request *top_read;
 351
 352                 DEBUG(11, ("cli_pull_read_done: top_req = %d\n",
 353                            state->top_req));
 354
 355                 if (state->reqs[state->top_req]->state < ASYNC_REQ_DONE) {
 356                         DEBUG(11, ("cli_pull_read_done: top request not yet "
 357                                    "done\n"));
 358                         return;
 359                 }
 360
 361                 top_read = cli_request_get(state->reqs[state->top_req]);
 362
 363                 DEBUG(10, ("cli_pull_read_done: Pushing %d bytes, %d already "
 364                            "pushed\n", (int)top_read->data.read.received,
 365                            (int)state->pushed));
 366
 367                 status = state->sink((char *)top_read->data.read.rcvbuf,
 368                                      top_read->data.read.received,
 369                                      state->priv);
 370                 if (!NT_STATUS_IS_OK(status)) {
 371                         async_req_error(state->req, status);
 372                         return;
 373                 }
 374                 state->pushed += top_read->data.read.received;
 375
 376                 TALLOC_FREE(state->reqs[state->top_req]);
 377
 378                 if (state->requested < state->size) {
 379                         struct async_req *new_req;
 380                         SMB_OFF_T size_left;
 381                         size_t request_thistime;
 382
 383                         size_left = state->size - state->requested;
 384                         request_thistime = MIN(size_left, state->chunk_size);
 385
 386                         DEBUG(10, ("cli_pull_read_done: Requesting %d bytes "
 387                                    "at %d, position %d\n",
 388                                    (int)request_thistime,
 389                                    (int)(state->start_offset
 390                                          + state->requested),
 391                                    state->top_req));
 392
 393                         new_req = cli_read_andx_send(
 394                                 state->reqs, state->cli, state->fnum,
 395                                 state->start_offset + state->requested,
 396                                 request_thistime);
 397
 398                         if (async_req_nomem(new_req, state->req)) {
 399                                 return;
 400                         }
 401
 402                         new_req->async.fn = cli_pull_read_done;
 403                         new_req->async.priv = pull_req;
 404
 405                         state->reqs[state->top_req] = new_req;
 406                         state->requested += request_thistime;
 407                 }
 408
 409                 state->top_req = (state->top_req+1) % state->num_reqs;
 410         }
 411
 412         async_req_done(pull_req);
 413 }
 414
 415 NTSTATUS cli_pull_recv(struct async_req *req, SMB_OFF_T *received)
 416 {
 417         struct cli_pull_state *state = talloc_get_type_abort(
 418                 req->private_data, struct cli_pull_state);
 419
 420         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 421         if (req->state == ASYNC_REQ_ERROR) {
 422                 return req->status;
 423         }
 424         *received = state->pushed;
 425         return NT_STATUS_OK;
 426 }
 427
 428 NTSTATUS cli_pull(struct cli_state *cli, uint16_t fnum,
 429                   off_t start_offset, SMB_OFF_T size, size_t window_size,
 430                   NTSTATUS (*sink)(char *buf, size_t n, void *priv),
 431                   void *priv, SMB_OFF_T *received)
 432 {
 433         TALLOC_CTX *frame = talloc_stackframe();
 434         struct async_req *req;
 435         NTSTATUS result = NT_STATUS_NO_MEMORY;
 436
 437         if (cli_tmp_event_ctx(frame, cli) == NULL) {
 438                 goto nomem;
 439         }
 440
 441         req = cli_pull_send(frame, cli, fnum, start_offset, size, window_size,
 442                             sink, priv);
 443         if (req == NULL) {
 444                 goto nomem;
 445         }
 446
 447         while (req->state < ASYNC_REQ_DONE) {
 448                 event_loop_once(cli->event_ctx);
 449         }
 450
 451         result = cli_pull_recv(req, received);
 452  nomem:
 453         TALLOC_FREE(frame);
 454         return result;
 455 }
 456
 457 static NTSTATUS cli_read_sink(char *buf, size_t n, void *priv)
 458 {
 459         char **pbuf = (char **)priv;
 460         memcpy(*pbuf, buf, n);
 461         *pbuf += n;
 462         return NT_STATUS_OK;
 463 }
 464
 465 ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 466                  off_t offset, size_t size)
 467 {
 468         NTSTATUS status;
 469         SMB_OFF_T ret;
 470
 471         status = cli_pull(cli, fnum, offset, size, size,
 472                           cli_read_sink, &buf, &ret);
 473         if (!NT_STATUS_IS_OK(status)) {
 474                 cli_set_error(cli, status);
 475                 return -1;
 476         }
 477         return ret;
 478 }
 479
 480 #if 0  /* relies on client_receive_smb(), now a static in libsmb/clientgen.c */
 481
 482 /* This call is INCOMPATIBLE with SMB signing.  If you remove the #if 0
 483    you must fix ensure you don't attempt to sign the packets - data
 484    *will* be currupted */
 485
 486 /****************************************************************************
 487 Issue a single SMBreadraw and don't wait for a reply.
 488 ****************************************************************************/
 489
 490 static bool cli_issue_readraw(struct cli_state *cli, int fnum, off_t offset,
 491                            size_t size, int i)
 492 {
 493
 494         if (!cli->sign_info.use_smb_signing) {
 495                 DEBUG(0, ("Cannot use readraw and SMB Signing\n"));
 496                 return False;
 497         }
 498
 499         memset(cli->outbuf,'\0',smb_size);
 500         memset(cli->inbuf,'\0',smb_size);
 501
 502         cli_set_message(cli->outbuf,10,0,True);
 503
 504         SCVAL(cli->outbuf,smb_com,SMBreadbraw);
 505         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 506         cli_setup_packet(cli);
 507
 508         SSVAL(cli->outbuf,smb_vwv0,fnum);
 509         SIVAL(cli->outbuf,smb_vwv1,offset);
 510         SSVAL(cli->outbuf,smb_vwv2,size);
 511         SSVAL(cli->outbuf,smb_vwv3,size);
 512         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 513
 514         return cli_send_smb(cli);
 515 }
 516
 517 /****************************************************************************
 518  Tester for the readraw call.
 519 ****************************************************************************/
 520
 521 ssize_t cli_readraw(struct cli_state *cli, int fnum, char *buf, off_t offset, size_t size)
 522 {
 523         char *p;
 524         int size2;
 525         size_t readsize;
 526         ssize_t total = 0;
 527
 528         if (size == 0)
 529                 return 0;
 530
 531         /*
 532          * Set readsize to the maximum size we can handle in one readraw.
 533          */
 534
 535         readsize = 0xFFFF;
 536
 537         while (total < size) {
 538                 readsize = MIN(readsize, size-total);
 539
 540                 /* Issue a read and receive a reply */
 541
 542                 if (!cli_issue_readraw(cli, fnum, offset, readsize, 0))
 543                         return -1;
 544
 545                 if (!client_receive_smb(cli->fd, cli->inbuf, cli->timeout))
 546                         return -1;
 547
 548                 size2 = smb_len(cli->inbuf);
 549
 550                 if (size2 > readsize) {
 551                         DEBUG(5,("server returned more than we wanted!\n"));
 552                         return -1;
 553                 } else if (size2 < 0) {
 554                         DEBUG(5,("read return < 0!\n"));
 555                         return -1;
 556                 }
 557
 558                 /* Copy data into buffer */
 559
 560                 if (size2) {
 561                         p = cli->inbuf + 4;
 562                         memcpy(buf + total, p, size2);
 563                 }
 564
 565                 total += size2;
 566                 offset += size2;
 567
 568                 /*
 569                  * If the server returned less than we asked for we're at EOF.
 570                  */
 571
 572                 if (size2 < readsize)
 573                         break;
 574         }
 575
 576         return total;
 577 }
 578 #endif
 579
 580 /****************************************************************************
 581  Issue a single SMBwrite and don't wait for a reply.
 582 ****************************************************************************/
 583
 584 static bool cli_issue_write(struct cli_state *cli,
 585                                 int fnum,
 586                                 off_t offset,
 587                                 uint16 mode,
 588                                 const char *buf,
 589                                 size_t size,
 590                                 int i)
 591 {
 592         char *p;
 593         bool large_writex = false;
 594         /* We can only do direct writes if not signing and not encrypting. */
 595         bool direct_writes = !client_is_signing_on(cli) && !cli_encryption_on(cli);
 596
 597         if (!direct_writes && size + 1 > cli->bufsize) {
 598                 cli->outbuf = (char *)SMB_REALLOC(cli->outbuf, size + 1024);
 599                 if (!cli->outbuf) {
 600                         return False;
 601                 }
 602                 cli->inbuf = (char *)SMB_REALLOC(cli->inbuf, size + 1024);
 603                 if (cli->inbuf == NULL) {
 604                         SAFE_FREE(cli->outbuf);
 605                         return False;
 606                 }
 607                 cli->bufsize = size + 1024;
 608         }
 609
 610         memset(cli->outbuf,'\0',smb_size);
 611         memset(cli->inbuf,'\0',smb_size);
 612
 613         if (cli->capabilities & CAP_LARGE_FILES) {
 614                 large_writex = True;
 615         }
 616
 617         if (large_writex) {
 618                 cli_set_message(cli->outbuf,14,0,True);
 619         } else {
 620                 cli_set_message(cli->outbuf,12,0,True);
 621         }
 622
 623         SCVAL(cli->outbuf,smb_com,SMBwriteX);
 624         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 625         cli_setup_packet(cli);
 626
 627         SCVAL(cli->outbuf,smb_vwv0,0xFF);
 628         SSVAL(cli->outbuf,smb_vwv2,fnum);
 629
 630         SIVAL(cli->outbuf,smb_vwv3,offset);
 631         SIVAL(cli->outbuf,smb_vwv5,0);
 632         SSVAL(cli->outbuf,smb_vwv7,mode);
 633
 634         SSVAL(cli->outbuf,smb_vwv8,(mode & 0x0008) ? size : 0);
 635         /*
 636          * According to CIFS-TR-1p00, this following field should only
 637          * be set if CAP_LARGE_WRITEX is set. We should check this
 638          * locally. However, this check might already have been
 639          * done by our callers.
 640          */
 641         SSVAL(cli->outbuf,smb_vwv9,(size>>16));
 642         SSVAL(cli->outbuf,smb_vwv10,size);
 643         /* +1 is pad byte. */
 644         SSVAL(cli->outbuf,smb_vwv11,
 645               smb_buf(cli->outbuf) - smb_base(cli->outbuf) + 1);
 646
 647         if (large_writex) {
 648                 SIVAL(cli->outbuf,smb_vwv12,(((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
 649         }
 650
 651         p = smb_base(cli->outbuf) + SVAL(cli->outbuf,smb_vwv11) -1;
 652         *p++ = '\0'; /* pad byte. */
 653         if (!direct_writes) {
 654                 memcpy(p, buf, size);
 655         }
 656         if (size > 0x1FFFF) {
 657                 /* This is a POSIX 14 word large write. */
 658                 set_message_bcc(cli->outbuf, 0); /* Set bcc to zero. */
 659                 _smb_setlen_large(cli->outbuf,smb_size + 28 + 1 /* pad */ + size - 4);
 660         } else {
 661                 cli_setup_bcc(cli, p+size);
 662         }
 663
 664         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 665
 666         show_msg(cli->outbuf);
 667         if (direct_writes) {
 668                 /* For direct writes we now need to write the data
 669                  * directly out of buf. */
 670                 return cli_send_smb_direct_writeX(cli, buf, size);
 671         } else {
 672                 return cli_send_smb(cli);
 673         }
 674 }
 675
 676 /****************************************************************************
 677   write to a file
 678   write_mode: 0x0001 disallow write cacheing
 679               0x0002 return bytes remaining
 680               0x0004 use raw named pipe protocol
 681               0x0008 start of message mode named pipe protocol
 682 ****************************************************************************/
 683
 684 ssize_t cli_write(struct cli_state *cli,
 685                  int fnum, uint16 write_mode,
 686                  const char *buf, off_t offset, size_t size)
 687 {
 688         ssize_t bwritten = 0;
 689         unsigned int issued = 0;
 690         unsigned int received = 0;
 691         int mpx = 1;
 692         size_t writesize;
 693         int blocks;
 694
 695         if(cli->max_mux > 1) {
 696                 mpx = cli->max_mux-1;
 697         } else {
 698                 mpx = 1;
 699         }
 700
 701         /* Default (small) writesize. */
 702         writesize = (cli->max_xmit - (smb_size+32)) & ~1023;
 703
 704         if (write_mode == 0 &&
 705                         !client_is_signing_on(cli) &&
 706                         !cli_encryption_on(cli) &&
 707                         (cli->posix_capabilities & CIFS_UNIX_LARGE_WRITE_CAP) &&
 708                         (cli->capabilities & CAP_LARGE_FILES)) {
 709                 /* Only do massive writes if we can do them direct
 710                  * with no signing or encrypting - not on a pipe. */
 711                 writesize = CLI_SAMBA_MAX_POSIX_LARGE_WRITEX_SIZE;
 712         } else if (cli->capabilities & CAP_LARGE_WRITEX) {
 713                 if (cli->is_samba) {
 714                         writesize = CLI_SAMBA_MAX_LARGE_WRITEX_SIZE;
 715                 } else if (!client_is_signing_on(cli)) {
 716                         /* Windows restricts signed writes to max_xmit.
 717                          * Found by Volker. */
 718                         writesize = CLI_WINDOWS_MAX_LARGE_WRITEX_SIZE;
 719                 }
 720         }
 721
 722         blocks = (size + (writesize-1)) / writesize;
 723
 724         while (received < blocks) {
 725
 726                 while ((issued - received < mpx) && (issued < blocks)) {
 727                         ssize_t bsent = issued * writesize;
 728                         ssize_t size1 = MIN(writesize, size - bsent);
 729
 730                         if (!cli_issue_write(cli, fnum, offset + bsent,
 731                                         write_mode,
 732                                         buf + bsent,
 733                                         size1, issued))
 734                                 return -1;
 735                         issued++;
 736                 }
 737
 738                 if (!cli_receive_smb(cli)) {
 739                         return bwritten;
 740                 }
 741
 742                 received++;
 743
 744                 if (cli_is_error(cli))
 745                         break;
 746
 747                 bwritten += SVAL(cli->inbuf, smb_vwv2);
 748                 bwritten += (((int)(SVAL(cli->inbuf, smb_vwv4)))<<16);
 749         }
 750
 751         while (received < issued && cli_receive_smb(cli)) {
 752                 received++;
 753         }
 754
 755         return bwritten;
 756 }
 757
 758 /****************************************************************************
 759   write to a file using a SMBwrite and not bypassing 0 byte writes
 760 ****************************************************************************/
 761
 762 ssize_t cli_smbwrite(struct cli_state *cli,
 763                      int fnum, char *buf, off_t offset, size_t size1)
 764 {
 765         char *p;
 766         ssize_t total = 0;
 767
 768         do {
 769                 size_t size = MIN(size1, cli->max_xmit - 48);
 770
 771                 memset(cli->outbuf,'\0',smb_size);
 772                 memset(cli->inbuf,'\0',smb_size);
 773
 774                 cli_set_message(cli->outbuf,5, 0,True);
 775
 776                 SCVAL(cli->outbuf,smb_com,SMBwrite);
 777                 SSVAL(cli->outbuf,smb_tid,cli->cnum);
 778                 cli_setup_packet(cli);
 779
 780                 SSVAL(cli->outbuf,smb_vwv0,fnum);
 781                 SSVAL(cli->outbuf,smb_vwv1,size);
 782                 SIVAL(cli->outbuf,smb_vwv2,offset);
 783                 SSVAL(cli->outbuf,smb_vwv4,0);
 784
 785                 p = smb_buf(cli->outbuf);
 786                 *p++ = 1;
 787                 SSVAL(p, 0, size); p += 2;
 788                 memcpy(p, buf + total, size); p += size;
 789
 790                 cli_setup_bcc(cli, p);
 791
 792                 if (!cli_send_smb(cli))
 793                         return -1;
 794
 795                 if (!cli_receive_smb(cli))
 796                         return -1;
 797
 798                 if (cli_is_error(cli))
 799                         return -1;
 800
 801                 size = SVAL(cli->inbuf,smb_vwv0);
 802                 if (size == 0)
 803                         break;
 804
 805                 size1 -= size;
 806                 total += size;
 807                 offset += size;
 808
 809         } while (size1);
 810
 811         return total;
 812 }