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