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