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