source/libsmb/clientgen.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB client generic functions
   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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  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 BOOL client_receive_smb(struct cli_state *cli, BOOL eat_keepalives)
  58 {
  59         BOOL ret;
  60         int fd = cli->fd;
  61         char *buffer = cli->inbuf;
  62         unsigned int timeout = cli->timeout;
  63
  64         for(;;) {
  65                 ret = receive_smb_raw(fd, buffer, timeout);
  66
  67                 if (!ret) {
  68                         DEBUG(10,("client_receive_smb failed\n"));
  69                         show_msg(buffer);
  70                         return ret;
  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 False;
  89                 }
  90         }
  91         show_msg(buffer);
  92         return ret;
  93 }
  94
  95 /****************************************************************************
  96  Recv an smb.
  97 ****************************************************************************/
  98
  99 BOOL cli_receive_smb_internal(struct cli_state *cli, BOOL eat_keepalives)
 100 {
 101         BOOL ret;
 102
 103         /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
 104         if (cli->fd == -1)
 105                 return False;
 106
 107  again:
 108         ret = client_receive_smb(cli, eat_keepalives);
 109
 110         if (!eat_keepalives && (CVAL(cli->inbuf,0) == SMBkeepalive)) {
 111                 /* Give back the keepalive. */
 112                 return True;
 113         }
 114
 115         if (ret) {
 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)) return False;
 125                         }
 126                         /* try to prevent loops */
 127                         SCVAL(cli->inbuf,smb_com,0xFF);
 128                         goto again;
 129                 }
 130         }
 131
 132         /* If the server is not responding, note that now */
 133         if (!ret) {
 134                 DEBUG(0, ("Receiving SMB: Server stopped responding\n"));
 135                 cli->smb_rw_error = smb_read_error;
 136                 close(cli->fd);
 137                 cli->fd = -1;
 138                 return ret;
 139         }
 140
 141         if (!cli_check_sign_mac(cli)) {
 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
 149         return True;
 150 }
 151
 152 /****************************************************************************
 153  Recv an smb - eat keepalives.
 154 ****************************************************************************/
 155
 156 BOOL cli_receive_smb(struct cli_state *cli)
 157 {
 158         return cli_receive_smb_internal(cli, True);
 159 }
 160
 161 /****************************************************************************
 162  Recv an smb - return keepalives.
 163 ****************************************************************************/
 164
 165 BOOL cli_receive_smb_return_keepalive(struct cli_state *cli)
 166 {
 167         return cli_receive_smb_internal(cli, False);
 168 }
 169
 170 static ssize_t write_socket(int fd, const char *buf, size_t len)
 171 {
 172         ssize_t ret=0;
 173
 174         DEBUG(6,("write_socket(%d,%d)\n",fd,(int)len));
 175         ret = write_data(fd,buf,len);
 176
 177         DEBUG(6,("write_socket(%d,%d) wrote %d\n",fd,(int)len,(int)ret));
 178         if(ret <= 0)
 179                 DEBUG(0,("write_socket: Error writing %d bytes to socket %d: ERRNO = %s\n",
 180                         (int)len, fd, strerror(errno) ));
 181
 182         return(ret);
 183 }
 184
 185 /****************************************************************************
 186  Send an smb to a fd.
 187 ****************************************************************************/
 188
 189 BOOL cli_send_smb(struct cli_state *cli)
 190 {
 191         size_t len;
 192         size_t nwritten=0;
 193         ssize_t ret;
 194         char *buf_out = cli->outbuf;
 195         BOOL enc_on = cli_encryption_on(cli);
 196
 197         /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
 198         if (cli->fd == -1) {
 199                 return False;
 200         }
 201
 202         cli_calculate_sign_mac(cli);
 203
 204         if (enc_on) {
 205                 NTSTATUS status = cli_encrypt_message(cli, &buf_out);
 206                 if (!NT_STATUS_IS_OK(status)) {
 207                         close(cli->fd);
 208                         cli->fd = -1;
 209                         cli->smb_rw_error = WRITE_ERROR;
 210                         DEBUG(0,("Error in encrypting client message. Error %s\n",
 211                                 nt_errstr(status) ));
 212                         return False;
 213                 }
 214         }
 215
 216         len = smb_len(buf_out) + 4;
 217
 218         while (nwritten < len) {
 219                 ret = write_socket(cli->fd,buf_out+nwritten,len - nwritten);
 220                 if (ret <= 0) {
 221                         if (enc_on) {
 222                                 cli_free_enc_buffer(cli, buf_out);
 223                         }
 224                         close(cli->fd);
 225                         cli->fd = -1;
 226                         cli->smb_rw_error = WRITE_ERROR;
 227                         DEBUG(0,("Error writing %d bytes to client. %d (%s)\n",
 228                                 (int)len,(int)ret, strerror(errno) ));
 229                         return False;
 230                 }
 231                 nwritten += ret;
 232         }
 233
 234         cli_free_enc_buffer(cli, buf_out);
 235
 236         /* Increment the mid so we can tell between responses. */
 237         cli->mid++;
 238         if (!cli->mid) {
 239                 cli->mid++;
 240         }
 241         return True;
 242 }
 243
 244 /****************************************************************************
 245  Setup basics in a outgoing packet.
 246 ****************************************************************************/
 247
 248 void cli_setup_packet(struct cli_state *cli)
 249 {
 250         cli->rap_error = 0;
 251         SSVAL(cli->outbuf,smb_pid,cli->pid);
 252         SSVAL(cli->outbuf,smb_uid,cli->vuid);
 253         SSVAL(cli->outbuf,smb_mid,cli->mid);
 254         if (cli->protocol > PROTOCOL_CORE) {
 255                 uint16 flags2;
 256                 if (cli->case_sensitive) {
 257                         SCVAL(cli->outbuf,smb_flg,0x0);
 258                 } else {
 259                         /* Default setting, case insensitive. */
 260                         SCVAL(cli->outbuf,smb_flg,0x8);
 261                 }
 262                 flags2 = FLAGS2_LONG_PATH_COMPONENTS;
 263                 if (cli->capabilities & CAP_UNICODE)
 264                         flags2 |= FLAGS2_UNICODE_STRINGS;
 265                 if ((cli->capabilities & CAP_DFS) && cli->dfsroot)
 266                         flags2 |= FLAGS2_DFS_PATHNAMES;
 267                 if (cli->capabilities & CAP_STATUS32)
 268                         flags2 |= FLAGS2_32_BIT_ERROR_CODES;
 269                 if (cli->use_spnego)
 270                         flags2 |= FLAGS2_EXTENDED_SECURITY;
 271                 SSVAL(cli->outbuf,smb_flg2, flags2);
 272         }
 273 }
 274
 275 /****************************************************************************
 276  Setup the bcc length of the packet from a pointer to the end of the data.
 277 ****************************************************************************/
 278
 279 void cli_setup_bcc(struct cli_state *cli, void *p)
 280 {
 281         set_message_bcc(cli->outbuf, PTR_DIFF(p, smb_buf(cli->outbuf)));
 282 }
 283
 284 /****************************************************************************
 285  Initialise credentials of a client structure.
 286 ****************************************************************************/
 287
 288 void cli_init_creds(struct cli_state *cli, const char *username, const char *domain, const char *password)
 289 {
 290         fstrcpy(cli->domain, domain);
 291         fstrcpy(cli->user_name, username);
 292         pwd_set_cleartext(&cli->pwd, password);
 293         if (!*username) {
 294                 cli->pwd.null_pwd = True;
 295         }
 296
 297         DEBUG(10,("cli_init_creds: user %s domain %s\n", cli->user_name, cli->domain));
 298 }
 299
 300 /****************************************************************************
 301  Set the signing state (used from the command line).
 302 ****************************************************************************/
 303
 304 void cli_setup_signing_state(struct cli_state *cli, int signing_state)
 305 {
 306         if (signing_state == Undefined)
 307                 return;
 308
 309         if (signing_state == False) {
 310                 cli->sign_info.allow_smb_signing = False;
 311                 cli->sign_info.mandatory_signing = False;
 312                 return;
 313         }
 314
 315         cli->sign_info.allow_smb_signing = True;
 316
 317         if (signing_state == Required)
 318                 cli->sign_info.mandatory_signing = True;
 319 }
 320
 321 /****************************************************************************
 322  Initialise a client structure. Always returns a malloc'ed struct.
 323 ****************************************************************************/
 324
 325 struct cli_state *cli_initialise(void)
 326 {
 327         struct cli_state *cli = NULL;
 328
 329         /* Check the effective uid - make sure we are not setuid */
 330         if (is_setuid_root()) {
 331                 DEBUG(0,("libsmb based programs must *NOT* be setuid root.\n"));
 332                 return NULL;
 333         }
 334
 335         cli = SMB_MALLOC_P(struct cli_state);
 336         if (!cli) {
 337                 return NULL;
 338         }
 339
 340         ZERO_STRUCTP(cli);
 341
 342         cli->port = 0;
 343         cli->fd = -1;
 344         cli->cnum = -1;
 345         cli->pid = (uint16)sys_getpid();
 346         cli->mid = 1;
 347         cli->vuid = UID_FIELD_INVALID;
 348         cli->protocol = PROTOCOL_NT1;
 349         cli->timeout = 20000; /* Timeout is in milliseconds. */
 350         cli->bufsize = CLI_BUFFER_SIZE+4;
 351         cli->max_xmit = cli->bufsize;
 352         cli->outbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
 353         cli->inbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
 354         cli->oplock_handler = cli_oplock_ack;
 355         cli->case_sensitive = False;
 356         cli->smb_rw_error = 0;
 357
 358         cli->use_spnego = lp_client_use_spnego();
 359
 360         cli->capabilities = CAP_UNICODE | CAP_STATUS32 | CAP_DFS;
 361
 362         /* Set the CLI_FORCE_DOSERR environment variable to test
 363            client routines using DOS errors instead of STATUS32
 364            ones.  This intended only as a temporary hack. */
 365         if (getenv("CLI_FORCE_DOSERR"))
 366                 cli->force_dos_errors = True;
 367
 368         if (lp_client_signing())
 369                 cli->sign_info.allow_smb_signing = True;
 370
 371         if (lp_client_signing() == Required)
 372                 cli->sign_info.mandatory_signing = True;
 373
 374         if (!cli->outbuf || !cli->inbuf)
 375                 goto error;
 376
 377         if ((cli->mem_ctx = talloc_init("cli based talloc")) == NULL)
 378                 goto error;
 379
 380         memset(cli->outbuf, 0, cli->bufsize);
 381         memset(cli->inbuf, 0, cli->bufsize);
 382
 383
 384 #if defined(DEVELOPER)
 385         /* just because we over-allocate, doesn't mean it's right to use it */
 386         clobber_region(FUNCTION_MACRO, __LINE__, cli->outbuf+cli->bufsize, SAFETY_MARGIN);
 387         clobber_region(FUNCTION_MACRO, __LINE__, cli->inbuf+cli->bufsize, SAFETY_MARGIN);
 388 #endif
 389
 390         /* initialise signing */
 391         cli_null_set_signing(cli);
 392
 393         cli->initialised = 1;
 394
 395         return cli;
 396
 397         /* Clean up after malloc() error */
 398
 399  error:
 400
 401         SAFE_FREE(cli->inbuf);
 402         SAFE_FREE(cli->outbuf);
 403         SAFE_FREE(cli);
 404         return NULL;
 405 }
 406
 407 /****************************************************************************
 408  External interface.
 409  Close an open named pipe over SMB. Free any authentication data.
 410  Returns False if the cli_close call failed.
 411  ****************************************************************************/
 412
 413 BOOL cli_rpc_pipe_close(struct rpc_pipe_client *cli)
 414 {
 415         BOOL ret;
 416
 417         if (!cli) {
 418                 return False;
 419         }
 420
 421         ret = cli_close(cli->cli, cli->fnum);
 422
 423         if (!ret) {
 424                 DEBUG(1,("cli_rpc_pipe_close: cli_close failed on pipe %s, "
 425                          "fnum 0x%x "
 426                          "to machine %s.  Error was %s\n",
 427                          cli->pipe_name,
 428                          (int) cli->fnum,
 429                          cli->cli->desthost,
 430                          cli_errstr(cli->cli)));
 431         }
 432
 433         if (cli->auth.cli_auth_data_free_func) {
 434                 (*cli->auth.cli_auth_data_free_func)(&cli->auth);
 435         }
 436
 437         DEBUG(10,("cli_rpc_pipe_close: closed pipe %s to machine %s\n",
 438                 cli->pipe_name, cli->cli->desthost ));
 439
 440         DLIST_REMOVE(cli->cli->pipe_list, cli);
 441         talloc_destroy(cli->mem_ctx);
 442         return ret;
 443 }
 444
 445 /****************************************************************************
 446  Close all pipes open on this session.
 447 ****************************************************************************/
 448
 449 void cli_nt_pipes_close(struct cli_state *cli)
 450 {
 451         struct rpc_pipe_client *cp, *next;
 452
 453         for (cp = cli->pipe_list; cp; cp = next) {
 454                 next = cp->next;
 455                 cli_rpc_pipe_close(cp);
 456         }
 457 }
 458
 459 /****************************************************************************
 460  Shutdown a client structure.
 461 ****************************************************************************/
 462
 463 void cli_shutdown(struct cli_state *cli)
 464 {
 465         cli_nt_pipes_close(cli);
 466
 467         /*
 468          * tell our peer to free his resources.  Wihtout this, when an
 469          * application attempts to do a graceful shutdown and calls
 470          * smbc_free_context() to clean up all connections, some connections
 471          * can remain active on the peer end, until some (long) timeout period
 472          * later.  This tree disconnect forces the peer to clean up, since the
 473          * connection will be going away.
 474          *
 475          * Also, do not do tree disconnect when cli->smb_rw_error is DO_NOT_DO_TDIS
 476          * the only user for this so far is smbmount which passes opened connection
 477          * down to kernel's smbfs module.
 478          */
 479         if ( (cli->cnum != (uint16)-1) && (cli->smb_rw_error != DO_NOT_DO_TDIS ) ) {
 480                 cli_tdis(cli);
 481         }
 482
 483         SAFE_FREE(cli->outbuf);
 484         SAFE_FREE(cli->inbuf);
 485
 486         cli_free_signing_context(cli);
 487         cli_free_encryption_context(cli);
 488
 489         data_blob_free(&cli->secblob);
 490         data_blob_free(&cli->user_session_key);
 491
 492         if (cli->mem_ctx) {
 493                 talloc_destroy(cli->mem_ctx);
 494                 cli->mem_ctx = NULL;
 495         }
 496
 497         if (cli->fd != -1) {
 498                 close(cli->fd);
 499         }
 500         cli->fd = -1;
 501         cli->smb_rw_error = 0;
 502
 503         SAFE_FREE(cli);
 504 }
 505
 506 /****************************************************************************
 507  Set socket options on a open connection.
 508 ****************************************************************************/
 509
 510 void cli_sockopt(struct cli_state *cli, const char *options)
 511 {
 512         set_socket_options(cli->fd, options);
 513 }
 514
 515 /****************************************************************************
 516  Set the PID to use for smb messages. Return the old pid.
 517 ****************************************************************************/
 518
 519 uint16 cli_setpid(struct cli_state *cli, uint16 pid)
 520 {
 521         uint16 ret = cli->pid;
 522         cli->pid = pid;
 523         return ret;
 524 }
 525
 526 /****************************************************************************
 527  Set the case sensitivity flag on the packets. Returns old state.
 528 ****************************************************************************/
 529
 530 BOOL cli_set_case_sensitive(struct cli_state *cli, BOOL case_sensitive)
 531 {
 532         BOOL ret = cli->case_sensitive;
 533         cli->case_sensitive = case_sensitive;
 534         return ret;
 535 }
 536
 537 /****************************************************************************
 538 Send a keepalive packet to the server
 539 ****************************************************************************/
 540
 541 BOOL cli_send_keepalive(struct cli_state *cli)
 542 {
 543         if (cli->fd == -1) {
 544                 DEBUG(3, ("cli_send_keepalive: fd == -1\n"));
 545                 return False;
 546         }
 547         if (!send_keepalive(cli->fd)) {
 548                 close(cli->fd);
 549                 cli->fd = -1;
 550                 DEBUG(0,("Error sending keepalive packet to client.\n"));
 551                 return False;
 552         }
 553         return True;
 554 }
 555
 556 /****************************************************************************
 557  Send/receive a SMBecho command: ping the server
 558 ****************************************************************************/
 559
 560 BOOL cli_echo(struct cli_state *cli, unsigned char *data, size_t length)
 561 {
 562         char *p;
 563
 564         SMB_ASSERT(length < 1024);
 565
 566         memset(cli->outbuf,'\0',smb_size);
 567         set_message(cli->outbuf,1,length,True);
 568         SCVAL(cli->outbuf,smb_com,SMBecho);
 569         SSVAL(cli->outbuf,smb_tid,65535);
 570         SSVAL(cli->outbuf,smb_vwv0,1);
 571         cli_setup_packet(cli);
 572         p = smb_buf(cli->outbuf);
 573         memcpy(p, data, length);
 574         p += length;
 575
 576         cli_setup_bcc(cli, p);
 577
 578         cli_send_smb(cli);
 579         if (!cli_receive_smb(cli)) {
 580                 return False;
 581         }
 582
 583         if (cli_is_error(cli)) {
 584                 return False;
 585         }
 586         return True;
 587 }