source3/libsmb/clientgen.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB client generic functions
   4    Copyright (C) Andrew Tridgell 1994-1998
   5    Copyright (C) Jeremy Allison 2007.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 extern int smb_read_error;
  24
  25 /****************************************************************************
  26  Change the timeout (in milliseconds).
  27 ****************************************************************************/
  28
  29 unsigned int cli_set_timeout(struct cli_state *cli, unsigned int timeout)
  30 {
  31         unsigned int old_timeout = cli->timeout;
  32         cli->timeout = timeout;
  33         return old_timeout;
  34 }
  35
  36 /****************************************************************************
  37  Change the port number used to call on.
  38 ****************************************************************************/
  39
  40 int cli_set_port(struct cli_state *cli, int port)
  41 {
  42         cli->port = port;
  43         return port;
  44 }
  45
  46 /****************************************************************************
  47  Read an smb from a fd ignoring all keepalive packets. Note that the buffer
  48  *MUST* be of size BUFFER_SIZE+SAFETY_MARGIN.
  49  The timeout is in milliseconds
  50
  51  This is exactly the same as receive_smb except that it can be set to never return
  52  a session keepalive packet (just as receive_smb used to do).
  53  receive_smb was changed to return keepalives as the oplock processing means this call
  54  should never go into a blocking read.
  55 ****************************************************************************/
  56
  57 static ssize_t client_receive_smb(struct cli_state *cli, BOOL eat_keepalives, size_t maxlen)
  58 {
  59         ssize_t len;
  60         int fd = cli->fd;
  61         char *buffer = cli->inbuf;
  62         unsigned int timeout = cli->timeout;
  63
  64         for(;;) {
  65                 len = receive_smb_raw(fd, buffer, timeout, maxlen);
  66
  67                 if (len < 0) {
  68                         DEBUG(10,("client_receive_smb failed\n"));
  69                         show_msg(buffer);
  70                         return len;
  71                 }
  72
  73                 /* Ignore session keepalive packets. */
  74                 if (eat_keepalives && (CVAL(buffer,0) == SMBkeepalive)) {
  75                         continue;
  76                 }
  77                 break;
  78         }
  79
  80         if (cli_encryption_on(cli)) {
  81                 NTSTATUS status = cli_decrypt_message(cli);
  82                 if (!NT_STATUS_IS_OK(status)) {
  83                         DEBUG(0, ("SMB decryption failed on incoming packet! Error %s\n",
  84                                 nt_errstr(status)));
  85                         cli->smb_rw_error = READ_BAD_DECRYPT;
  86                         close(cli->fd);
  87                         cli->fd = -1;
  88                         return -1;
  89                 }
  90         }
  91         show_msg(buffer);
  92         return len;
  93 }
  94
  95 /****************************************************************************
  96  Recv an smb.
  97 ****************************************************************************/
  98
  99 BOOL cli_receive_smb_internal(struct cli_state *cli, BOOL eat_keepalives)
 100 {
 101         ssize_t len;
 102
 103         /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
 104         if (cli->fd == -1)
 105                 return False;
 106
 107  again:
 108         len = client_receive_smb(cli, eat_keepalives, 0);
 109
 110         if (len >= 0 && !eat_keepalives && (CVAL(cli->inbuf,0) == SMBkeepalive)) {
 111                 /* Give back the keepalive. */
 112                 return True;
 113         }
 114
 115         if (len > 0) {
 116                 /* it might be an oplock break request */
 117                 if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) &&
 118                     CVAL(cli->inbuf,smb_com) == SMBlockingX &&
 119                     SVAL(cli->inbuf,smb_vwv6) == 0 &&
 120                     SVAL(cli->inbuf,smb_vwv7) == 0) {
 121                         if (cli->oplock_handler) {
 122                                 int fnum = SVAL(cli->inbuf,smb_vwv2);
 123                                 unsigned char level = CVAL(cli->inbuf,smb_vwv3+1);
 124                                 if (!cli->oplock_handler(cli, fnum, level)) {
 125                                         return False;
 126                                 }
 127                         }
 128                         /* try to prevent loops */
 129                         SCVAL(cli->inbuf,smb_com,0xFF);
 130                         goto again;
 131                 }
 132         }
 133
 134         /* If the server is not responding, note that now */
 135         if (len < 0) {
 136                 DEBUG(0, ("Receiving SMB: Server stopped responding\n"));
 137                 cli->smb_rw_error = smb_read_error;
 138                 close(cli->fd);
 139                 cli->fd = -1;
 140                 return False;
 141         }
 142
 143         if (!cli_check_sign_mac(cli)) {
 144                 /*
 145                  * If we get a signature failure in sessionsetup, then
 146                  * the server sometimes just reflects the sent signature
 147                  * back to us. Detect this and allow the upper layer to
 148                  * retrieve the correct Windows error message.
 149                  */
 150                 if (CVAL(cli->outbuf,smb_com) == SMBsesssetupX &&
 151                         (smb_len(cli->inbuf) > (smb_ss_field + 8 - 4)) &&
 152                         (SVAL(cli->inbuf,smb_flg2) & FLAGS2_SMB_SECURITY_SIGNATURES) &&
 153                         memcmp(&cli->outbuf[smb_ss_field],&cli->inbuf[smb_ss_field],8) == 0 &&
 154                         cli_is_error(cli)) {
 155
 156                         /*
 157                          * Reflected signature on login error.
 158                          * Set bad sig but don't close fd.
 159                          */
 160                         cli->smb_rw_error = READ_BAD_SIG;
 161                         return True;
 162                 }
 163
 164                 DEBUG(0, ("SMB Signature verification failed on incoming packet!\n"));
 165                 cli->smb_rw_error = READ_BAD_SIG;
 166                 close(cli->fd);
 167                 cli->fd = -1;
 168                 return False;
 169         }
 170
 171         return True;
 172 }
 173
 174 /****************************************************************************
 175  Recv an smb - eat keepalives.
 176 ****************************************************************************/
 177
 178 BOOL cli_receive_smb(struct cli_state *cli)
 179 {
 180         return cli_receive_smb_internal(cli, True);
 181 }
 182
 183 /****************************************************************************
 184  Recv an smb - return keepalives.
 185 ****************************************************************************/
 186
 187 BOOL cli_receive_smb_return_keepalive(struct cli_state *cli)
 188 {
 189         return cli_receive_smb_internal(cli, False);
 190 }
 191
 192 /****************************************************************************
 193  Read the data portion of a readX smb.
 194  The timeout is in milliseconds
 195 ****************************************************************************/
 196
 197 ssize_t cli_receive_smb_data(struct cli_state *cli, char *buffer, size_t len)
 198 {
 199         if (cli->timeout > 0) {
 200                 return read_socket_with_timeout(cli->fd, buffer, len, len, cli->timeout);
 201         } else {
 202                 return read_data(cli->fd, buffer, len);
 203         }
 204 }
 205
 206 /****************************************************************************
 207  Read a smb readX header.
 208  We can only use this if encryption and signing are off.
 209 ****************************************************************************/
 210
 211 BOOL cli_receive_smb_readX_header(struct cli_state *cli)
 212 {
 213         ssize_t len, offset;
 214
 215         if (cli->fd == -1)
 216                 return False;
 217
 218  again:
 219
 220         /* Read up to the size of a readX header reply. */
 221         len = client_receive_smb(cli, True, (smb_size - 4) + 24);
 222
 223         if (len > 0) {
 224                 /* it might be an oplock break request */
 225                 if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) &&
 226                     CVAL(cli->inbuf,smb_com) == SMBlockingX &&
 227                     SVAL(cli->inbuf,smb_vwv6) == 0 &&
 228                     SVAL(cli->inbuf,smb_vwv7) == 0) {
 229                         ssize_t total_len = smb_len(cli->inbuf);
 230
 231                         if (total_len > CLI_SAMBA_MAX_LARGE_READX_SIZE+SAFETY_MARGIN) {
 232                                 goto read_err;
 233                         }
 234
 235                         /* Read the rest of the data. */
 236                         if ((total_len - len > 0) &&
 237                             !cli_receive_smb_data(cli,cli->inbuf+len,total_len - len)) {
 238                                 goto read_err;
 239                         }
 240
 241                         if (cli->oplock_handler) {
 242                                 int fnum = SVAL(cli->inbuf,smb_vwv2);
 243                                 unsigned char level = CVAL(cli->inbuf,smb_vwv3+1);
 244                                 if (!cli->oplock_handler(cli, fnum, level)) return False;
 245                         }
 246                         /* try to prevent loops */
 247                         SCVAL(cli->inbuf,smb_com,0xFF);
 248                         goto again;
 249                 }
 250         }
 251
 252         /* If it's not the above size it probably was an error packet. */
 253
 254         if ((len == (smb_size - 4) + 24) && !cli_is_error(cli)) {
 255                 /* Check it's a non-chained readX reply. */
 256                 if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) ||
 257                         (CVAL(cli->inbuf,smb_vwv0) != 0xFF) ||
 258                         (CVAL(cli->inbuf,smb_com) != SMBreadX)) {
 259                         /*
 260                          * We're not coping here with asnyc replies to
 261                          * other calls. Punt here - we need async client
 262                          * libs for this.
 263                          */
 264                         goto read_err;
 265                 }
 266
 267                 /*
 268                  * We know it's a readX reply - ensure we've read the
 269                  * padding bytes also.
 270                  */
 271
 272                 offset = SVAL(cli->inbuf,smb_vwv6);
 273                 if (offset > len) {
 274                         ssize_t ret;
 275                         size_t padbytes = offset - len;
 276                         ret = cli_receive_smb_data(cli,smb_buf(cli->inbuf),padbytes);
 277                         if (ret != padbytes) {
 278                                 goto read_err;
 279                         }
 280                 }
 281         }
 282
 283         return True;
 284
 285   read_err:
 286
 287         cli->smb_rw_error = smb_read_error = READ_ERROR;
 288         close(cli->fd);
 289         cli->fd = -1;
 290         return False;
 291 }
 292
 293 static ssize_t write_socket(int fd, const char *buf, size_t len)
 294 {
 295         ssize_t ret=0;
 296
 297         DEBUG(6,("write_socket(%d,%d)\n",fd,(int)len));
 298         ret = write_data(fd,buf,len);
 299
 300         DEBUG(6,("write_socket(%d,%d) wrote %d\n",fd,(int)len,(int)ret));
 301         if(ret <= 0)
 302                 DEBUG(0,("write_socket: Error writing %d bytes to socket %d: ERRNO = %s\n",
 303                         (int)len, fd, strerror(errno) ));
 304
 305         return(ret);
 306 }
 307
 308 /****************************************************************************
 309  Send an smb to a fd.
 310 ****************************************************************************/
 311
 312 BOOL cli_send_smb(struct cli_state *cli)
 313 {
 314         size_t len;
 315         size_t nwritten=0;
 316         ssize_t ret;
 317         char *buf_out = cli->outbuf;
 318         BOOL enc_on = cli_encryption_on(cli);
 319
 320         /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
 321         if (cli->fd == -1) {
 322                 return False;
 323         }
 324
 325         cli_calculate_sign_mac(cli);
 326
 327         if (enc_on) {
 328                 NTSTATUS status = cli_encrypt_message(cli, &buf_out);
 329                 if (!NT_STATUS_IS_OK(status)) {
 330                         close(cli->fd);
 331                         cli->fd = -1;
 332                         cli->smb_rw_error = WRITE_ERROR;
 333                         DEBUG(0,("Error in encrypting client message. Error %s\n",
 334                                 nt_errstr(status) ));
 335                         return False;
 336                 }
 337         }
 338
 339         len = smb_len(buf_out) + 4;
 340
 341         while (nwritten < len) {
 342                 ret = write_socket(cli->fd,buf_out+nwritten,len - nwritten);
 343                 if (ret <= 0) {
 344                         if (enc_on) {
 345                                 cli_free_enc_buffer(cli, buf_out);
 346                         }
 347                         close(cli->fd);
 348                         cli->fd = -1;
 349                         cli->smb_rw_error = WRITE_ERROR;
 350                         DEBUG(0,("Error writing %d bytes to client. %d (%s)\n",
 351                                 (int)len,(int)ret, strerror(errno) ));
 352                         return False;
 353                 }
 354                 nwritten += ret;
 355         }
 356
 357         cli_free_enc_buffer(cli, buf_out);
 358
 359         /* Increment the mid so we can tell between responses. */
 360         cli->mid++;
 361         if (!cli->mid) {
 362                 cli->mid++;
 363         }
 364         return True;
 365 }
 366
 367 /****************************************************************************
 368  Setup basics in a outgoing packet.
 369 ****************************************************************************/
 370
 371 void cli_setup_packet(struct cli_state *cli)
 372 {
 373         cli->rap_error = 0;
 374         SSVAL(cli->outbuf,smb_pid,cli->pid);
 375         SSVAL(cli->outbuf,smb_uid,cli->vuid);
 376         SSVAL(cli->outbuf,smb_mid,cli->mid);
 377         if (cli->protocol > PROTOCOL_CORE) {
 378                 uint16 flags2;
 379                 if (cli->case_sensitive) {
 380                         SCVAL(cli->outbuf,smb_flg,0x0);
 381                 } else {
 382                         /* Default setting, case insensitive. */
 383                         SCVAL(cli->outbuf,smb_flg,0x8);
 384                 }
 385                 flags2 = FLAGS2_LONG_PATH_COMPONENTS;
 386                 if (cli->capabilities & CAP_UNICODE)
 387                         flags2 |= FLAGS2_UNICODE_STRINGS;
 388                 if ((cli->capabilities & CAP_DFS) && cli->dfsroot)
 389                         flags2 |= FLAGS2_DFS_PATHNAMES;
 390                 if (cli->capabilities & CAP_STATUS32)
 391                         flags2 |= FLAGS2_32_BIT_ERROR_CODES;
 392                 if (cli->use_spnego)
 393                         flags2 |= FLAGS2_EXTENDED_SECURITY;
 394                 SSVAL(cli->outbuf,smb_flg2, flags2);
 395         }
 396 }
 397
 398 /****************************************************************************
 399  Setup the bcc length of the packet from a pointer to the end of the data.
 400 ****************************************************************************/
 401
 402 void cli_setup_bcc(struct cli_state *cli, void *p)
 403 {
 404         set_message_bcc(NULL,cli->outbuf, PTR_DIFF(p, smb_buf(cli->outbuf)));
 405 }
 406
 407 /****************************************************************************
 408  Initialise credentials of a client structure.
 409 ****************************************************************************/
 410
 411 void cli_init_creds(struct cli_state *cli, const char *username, const char *domain, const char *password)
 412 {
 413         fstrcpy(cli->domain, domain);
 414         fstrcpy(cli->user_name, username);
 415         pwd_set_cleartext(&cli->pwd, password);
 416         if (!*username) {
 417                 cli->pwd.null_pwd = True;
 418         }
 419
 420         DEBUG(10,("cli_init_creds: user %s domain %s\n", cli->user_name, cli->domain));
 421 }
 422
 423 /****************************************************************************
 424  Set the signing state (used from the command line).
 425 ****************************************************************************/
 426
 427 void cli_setup_signing_state(struct cli_state *cli, int signing_state)
 428 {
 429         if (signing_state == Undefined)
 430                 return;
 431
 432         if (signing_state == False) {
 433                 cli->sign_info.allow_smb_signing = False;
 434                 cli->sign_info.mandatory_signing = False;
 435                 return;
 436         }
 437
 438         cli->sign_info.allow_smb_signing = True;
 439
 440         if (signing_state == Required)
 441                 cli->sign_info.mandatory_signing = True;
 442 }
 443
 444 /****************************************************************************
 445  Initialise a client structure. Always returns a malloc'ed struct.
 446 ****************************************************************************/
 447
 448 struct cli_state *cli_initialise(void)
 449 {
 450         struct cli_state *cli = NULL;
 451
 452         /* Check the effective uid - make sure we are not setuid */
 453         if (is_setuid_root()) {
 454                 DEBUG(0,("libsmb based programs must *NOT* be setuid root.\n"));
 455                 return NULL;
 456         }
 457
 458         cli = SMB_MALLOC_P(struct cli_state);
 459         if (!cli) {
 460                 return NULL;
 461         }
 462
 463         ZERO_STRUCTP(cli);
 464
 465         cli->port = 0;
 466         cli->fd = -1;
 467         cli->cnum = -1;
 468         cli->pid = (uint16)sys_getpid();
 469         cli->mid = 1;
 470         cli->vuid = UID_FIELD_INVALID;
 471         cli->protocol = PROTOCOL_NT1;
 472         cli->timeout = 20000; /* Timeout is in milliseconds. */
 473         cli->bufsize = CLI_BUFFER_SIZE+4;
 474         cli->max_xmit = cli->bufsize;
 475         cli->outbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
 476         cli->inbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
 477         cli->oplock_handler = cli_oplock_ack;
 478         cli->case_sensitive = False;
 479         cli->smb_rw_error = 0;
 480
 481         cli->use_spnego = lp_client_use_spnego();
 482
 483         cli->capabilities = CAP_UNICODE | CAP_STATUS32 | CAP_DFS;
 484
 485         /* Set the CLI_FORCE_DOSERR environment variable to test
 486            client routines using DOS errors instead of STATUS32
 487            ones.  This intended only as a temporary hack. */
 488         if (getenv("CLI_FORCE_DOSERR"))
 489                 cli->force_dos_errors = True;
 490
 491         if (lp_client_signing())
 492                 cli->sign_info.allow_smb_signing = True;
 493
 494         if (lp_client_signing() == Required)
 495                 cli->sign_info.mandatory_signing = True;
 496
 497         if (!cli->outbuf || !cli->inbuf)
 498                 goto error;
 499
 500         if ((cli->mem_ctx = talloc_init("cli based talloc")) == NULL)
 501                 goto error;
 502
 503         memset(cli->outbuf, 0, cli->bufsize);
 504         memset(cli->inbuf, 0, cli->bufsize);
 505
 506
 507 #if defined(DEVELOPER)
 508         /* just because we over-allocate, doesn't mean it's right to use it */
 509         clobber_region(FUNCTION_MACRO, __LINE__, cli->outbuf+cli->bufsize, SAFETY_MARGIN);
 510         clobber_region(FUNCTION_MACRO, __LINE__, cli->inbuf+cli->bufsize, SAFETY_MARGIN);
 511 #endif
 512
 513         /* initialise signing */
 514         cli_null_set_signing(cli);
 515
 516         cli->initialised = 1;
 517
 518         return cli;
 519
 520         /* Clean up after malloc() error */
 521
 522  error:
 523
 524         SAFE_FREE(cli->inbuf);
 525         SAFE_FREE(cli->outbuf);
 526         SAFE_FREE(cli);
 527         return NULL;
 528 }
 529
 530 /****************************************************************************
 531  External interface.
 532  Close an open named pipe over SMB. Free any authentication data.
 533  Returns False if the cli_close call failed.
 534  ****************************************************************************/
 535
 536 BOOL cli_rpc_pipe_close(struct rpc_pipe_client *cli)
 537 {
 538         BOOL ret;
 539
 540         if (!cli) {
 541                 return False;
 542         }
 543
 544         ret = cli_close(cli->cli, cli->fnum);
 545
 546         if (!ret) {
 547                 DEBUG(1,("cli_rpc_pipe_close: cli_close failed on pipe %s, "
 548                          "fnum 0x%x "
 549                          "to machine %s.  Error was %s\n",
 550                          cli->pipe_name,
 551                          (int) cli->fnum,
 552                          cli->cli->desthost,
 553                          cli_errstr(cli->cli)));
 554         }
 555
 556         if (cli->auth.cli_auth_data_free_func) {
 557                 (*cli->auth.cli_auth_data_free_func)(&cli->auth);
 558         }
 559
 560         DEBUG(10,("cli_rpc_pipe_close: closed pipe %s to machine %s\n",
 561                 cli->pipe_name, cli->cli->desthost ));
 562
 563         DLIST_REMOVE(cli->cli->pipe_list, cli);
 564         talloc_destroy(cli->mem_ctx);
 565         return ret;
 566 }
 567
 568 /****************************************************************************
 569  Close all pipes open on this session.
 570 ****************************************************************************/
 571
 572 void cli_nt_pipes_close(struct cli_state *cli)
 573 {
 574         struct rpc_pipe_client *cp, *next;
 575
 576         for (cp = cli->pipe_list; cp; cp = next) {
 577                 next = cp->next;
 578                 cli_rpc_pipe_close(cp);
 579         }
 580 }
 581
 582 /****************************************************************************
 583  Shutdown a client structure.
 584 ****************************************************************************/
 585
 586 void cli_shutdown(struct cli_state *cli)
 587 {
 588         cli_nt_pipes_close(cli);
 589
 590         /*
 591          * tell our peer to free his resources.  Wihtout this, when an
 592          * application attempts to do a graceful shutdown and calls
 593          * smbc_free_context() to clean up all connections, some connections
 594          * can remain active on the peer end, until some (long) timeout period
 595          * later.  This tree disconnect forces the peer to clean up, since the
 596          * connection will be going away.
 597          *
 598          * Also, do not do tree disconnect when cli->smb_rw_error is DO_NOT_DO_TDIS
 599          * the only user for this so far is smbmount which passes opened connection
 600          * down to kernel's smbfs module.
 601          */
 602         if ( (cli->cnum != (uint16)-1) && (cli->smb_rw_error != DO_NOT_DO_TDIS ) ) {
 603                 cli_tdis(cli);
 604         }
 605
 606         SAFE_FREE(cli->outbuf);
 607         SAFE_FREE(cli->inbuf);
 608
 609         cli_free_signing_context(cli);
 610         cli_free_encryption_context(cli);
 611
 612         data_blob_free(&cli->secblob);
 613         data_blob_free(&cli->user_session_key);
 614
 615         if (cli->mem_ctx) {
 616                 talloc_destroy(cli->mem_ctx);
 617                 cli->mem_ctx = NULL;
 618         }
 619
 620         if (cli->fd != -1) {
 621                 close(cli->fd);
 622         }
 623         cli->fd = -1;
 624         cli->smb_rw_error = 0;
 625
 626         SAFE_FREE(cli);
 627 }
 628
 629 /****************************************************************************
 630  Set socket options on a open connection.
 631 ****************************************************************************/
 632
 633 void cli_sockopt(struct cli_state *cli, const char *options)
 634 {
 635         set_socket_options(cli->fd, options);
 636 }
 637
 638 /****************************************************************************
 639  Set the PID to use for smb messages. Return the old pid.
 640 ****************************************************************************/
 641
 642 uint16 cli_setpid(struct cli_state *cli, uint16 pid)
 643 {
 644         uint16 ret = cli->pid;
 645         cli->pid = pid;
 646         return ret;
 647 }
 648
 649 /****************************************************************************
 650  Set the case sensitivity flag on the packets. Returns old state.
 651 ****************************************************************************/
 652
 653 BOOL cli_set_case_sensitive(struct cli_state *cli, BOOL case_sensitive)
 654 {
 655         BOOL ret = cli->case_sensitive;
 656         cli->case_sensitive = case_sensitive;
 657         return ret;
 658 }
 659
 660 /****************************************************************************
 661 Send a keepalive packet to the server
 662 ****************************************************************************/
 663
 664 BOOL cli_send_keepalive(struct cli_state *cli)
 665 {
 666         if (cli->fd == -1) {
 667                 DEBUG(3, ("cli_send_keepalive: fd == -1\n"));
 668                 return False;
 669         }
 670         if (!send_keepalive(cli->fd)) {
 671                 close(cli->fd);
 672                 cli->fd = -1;
 673                 DEBUG(0,("Error sending keepalive packet to client.\n"));
 674                 return False;
 675         }
 676         return True;
 677 }
 678
 679 /****************************************************************************
 680  Send/receive a SMBecho command: ping the server
 681 ****************************************************************************/
 682
 683 BOOL cli_echo(struct cli_state *cli, uint16 num_echos,
 684               unsigned char *data, size_t length)
 685 {
 686         char *p;
 687         int i;
 688
 689         SMB_ASSERT(length < 1024);
 690
 691         memset(cli->outbuf,'\0',smb_size);
 692         set_message(NULL,cli->outbuf,1,length,True);
 693         SCVAL(cli->outbuf,smb_com,SMBecho);
 694         SSVAL(cli->outbuf,smb_tid,65535);
 695         SSVAL(cli->outbuf,smb_vwv0,num_echos);
 696         cli_setup_packet(cli);
 697         p = smb_buf(cli->outbuf);
 698         memcpy(p, data, length);
 699         p += length;
 700
 701         cli_setup_bcc(cli, p);
 702
 703         cli_send_smb(cli);
 704
 705         for (i=0; i<num_echos; i++) {
 706                 if (!cli_receive_smb(cli)) {
 707                         return False;
 708                 }
 709
 710                 if (cli_is_error(cli)) {
 711                         return False;
 712                 }
 713         }
 714
 715         return True;
 716 }