source/libsmb/libsmb_server.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    SMB client library implementation
   4    Copyright (C) Andrew Tridgell 1998
   5    Copyright (C) Richard Sharpe 2000, 2002
   6    Copyright (C) John Terpstra 2000
   7    Copyright (C) Tom Jansen (Ninja ISD) 2002
   8    Copyright (C) Derrell Lipman 2003-2008
   9    Copyright (C) Jeremy Allison 2007, 2008
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "libsmbclient.h"
  27 #include "libsmb_internal.h"
  28
  29
  30 /*
  31  * Check a server for being alive and well.
  32  * returns 0 if the server is in shape. Returns 1 on error
  33  *
  34  * Also useable outside libsmbclient to enable external cache
  35  * to do some checks too.
  36  */
  37 int
  38 SMBC_check_server(SMBCCTX * context,
  39                   SMBCSRV * server)
  40 {
  41         socklen_t size;
  42         struct sockaddr addr;
  43
  44         size = sizeof(addr);
  45         return (getpeername(server->cli->fd, &addr, &size) == -1);
  46 }
  47
  48 /*
  49  * Remove a server from the cached server list it's unused.
  50  * On success, 0 is returned. 1 is returned if the server could not be removed.
  51  *
  52  * Also useable outside libsmbclient
  53  */
  54 int
  55 SMBC_remove_unused_server(SMBCCTX * context,
  56                           SMBCSRV * srv)
  57 {
  58         SMBCFILE * file;
  59
  60         /* are we being fooled ? */
  61         if (!context || !context->internal->initialized || !srv) {
  62                 return 1;
  63         }
  64
  65         /* Check all open files/directories for a relation with this server */
  66         for (file = context->internal->files; file; file = file->next) {
  67                 if (file->srv == srv) {
  68                         /* Still used */
  69                         DEBUG(3, ("smbc_remove_usused_server: "
  70                                   "%p still used by %p.\n",
  71                                   srv, file));
  72                         return 1;
  73                 }
  74         }
  75
  76         DLIST_REMOVE(context->internal->servers, srv);
  77
  78         cli_shutdown(srv->cli);
  79         srv->cli = NULL;
  80
  81         DEBUG(3, ("smbc_remove_usused_server: %p removed.\n", srv));
  82
  83         (context->cache.remove_cached_server_fn)(context, srv);
  84
  85         SAFE_FREE(srv);
  86         return 0;
  87 }
  88
  89 /****************************************************************
  90  * Call the auth_fn with fixed size (fstring) buffers.
  91  ***************************************************************/
  92 void
  93 SMBC_call_auth_fn(TALLOC_CTX *ctx,
  94                   SMBCCTX *context,
  95                   const char *server,
  96                   const char *share,
  97                   char **pp_workgroup,
  98                   char **pp_username,
  99                   char **pp_password)
 100 {
 101         fstring workgroup;
 102         fstring username;
 103         fstring password;
 104
 105         strlcpy(workgroup, *pp_workgroup, sizeof(workgroup));
 106         strlcpy(username, *pp_username, sizeof(username));
 107         strlcpy(password, *pp_password, sizeof(password));
 108
 109         (context->server.get_auth_data_fn)(
 110                 server, share,
 111                 workgroup, sizeof(workgroup),
 112                 username, sizeof(username),
 113                 password, sizeof(password));
 114
 115         TALLOC_FREE(*pp_workgroup);
 116         TALLOC_FREE(*pp_username);
 117         TALLOC_FREE(*pp_password);
 118
 119         *pp_workgroup = talloc_strdup(ctx, workgroup);
 120         *pp_username = talloc_strdup(ctx, username);
 121         *pp_password = talloc_strdup(ctx, password);
 122 }
 123
 124
 125 void
 126 SMBC_get_auth_data(const char *server, const char *share,
 127                    char *workgroup_buf, int workgroup_buf_len,
 128                    char *username_buf, int username_buf_len,
 129                    char *password_buf, int password_buf_len)
 130 {
 131         /* Default function just uses provided data.  Nothing to do. */
 132 }
 133
 134
 135
 136 SMBCSRV *
 137 SMBC_find_server(TALLOC_CTX *ctx,
 138                  SMBCCTX *context,
 139                  const char *server,
 140                  const char *share,
 141                  char **pp_workgroup,
 142                  char **pp_username,
 143                  char **pp_password)
 144 {
 145         SMBCSRV *srv;
 146         int auth_called = 0;
 147
 148 check_server_cache:
 149
 150         srv = (context->cache.get_cached_server_fn)(context,
 151                                                     server, share,
 152                                                     *pp_workgroup,
 153                                                     *pp_username);
 154
 155         if (!auth_called && !srv && (!*pp_username || !(*pp_username)[0] ||
 156                                      !*pp_password || !(*pp_password)[0])) {
 157                 SMBC_call_auth_fn(ctx, context, server, share,
 158                                   pp_workgroup, pp_username, pp_password);
 159
 160                 if (!pp_workgroup || !pp_username || !pp_password) {
 161                         return NULL;
 162                 }
 163
 164                 /*
 165                  * However, smbc_auth_fn may have picked up info relating to
 166                  * an existing connection, so try for an existing connection
 167                  * again ...
 168                  */
 169                 auth_called = 1;
 170                 goto check_server_cache;
 171
 172         }
 173
 174         if (srv) {
 175                 if ((context->server.check_server_fn)(context, srv)) {
 176                         /*
 177                          * This server is no good anymore
 178                          * Try to remove it and check for more possible
 179                          * servers in the cache
 180                          */
 181                         if ((context->server.remove_unused_server_fn)(context,
 182                                                                       srv)) {
 183                                 /*
 184                                  * We could not remove the server completely,
 185                                  * remove it from the cache so we will not get
 186                                  * it again. It will be removed when the last
 187                                  * file/dir is closed.
 188                                  */
 189                                 (context->cache.remove_cached_server_fn)(context,
 190                                                                          srv);
 191                         }
 192
 193                         /*
 194                          * Maybe there are more cached connections to this
 195                          * server
 196                          */
 197                         goto check_server_cache;
 198                 }
 199
 200                 return srv;
 201         }
 202
 203         return NULL;
 204 }
 205
 206 /*
 207  * Connect to a server, possibly on an existing connection
 208  *
 209  * Here, what we want to do is: If the server and username
 210  * match an existing connection, reuse that, otherwise, establish a
 211  * new connection.
 212  *
 213  * If we have to create a new connection, call the auth_fn to get the
 214  * info we need, unless the username and password were passed in.
 215  */
 216
 217 SMBCSRV *
 218 SMBC_server(TALLOC_CTX *ctx,
 219             SMBCCTX *context,
 220             bool connect_if_not_found,
 221             const char *server,
 222             const char *share,
 223             char **pp_workgroup,
 224             char **pp_username,
 225             char **pp_password)
 226 {
 227         SMBCSRV *srv=NULL;
 228         struct cli_state *c;
 229         struct nmb_name called, calling;
 230         const char *server_n = server;
 231         struct sockaddr_storage ss;
 232         int tried_reverse = 0;
 233         int port_try_first;
 234         int port_try_next;
 235         const char *username_used;
 236         NTSTATUS status;
 237
 238         zero_addr(&ss);
 239         ZERO_STRUCT(c);
 240
 241         if (server[0] == 0) {
 242                 errno = EPERM;
 243                 return NULL;
 244         }
 245
 246         /* Look for a cached connection */
 247         srv = SMBC_find_server(ctx, context, server, share,
 248                                pp_workgroup, pp_username, pp_password);
 249
 250         /*
 251          * If we found a connection and we're only allowed one share per
 252          * server...
 253          */
 254         if (srv && *share != '\0' && context->options.one_share_per_server) {
 255
 256                 /*
 257                  * ... then if there's no current connection to the share,
 258                  * connect to it.  SMBC_find_server(), or rather the function
 259                  * pointed to by context->cache.get_cached_srv_fn which
 260                  * was called by SMBC_find_server(), will have issued a tree
 261                  * disconnect if the requested share is not the same as the
 262                  * one that was already connected.
 263                  */
 264                 if (srv->cli->cnum == (uint16) -1) {
 265                         /* Ensure we have accurate auth info */
 266                         SMBC_call_auth_fn(ctx, context, server, share,
 267                                           pp_workgroup,
 268                                           pp_username,
 269                                           pp_password);
 270
 271                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 272                                 errno = ENOMEM;
 273                                 cli_shutdown(srv->cli);
 274                                 srv->cli = NULL;
 275                                 (context->cache.remove_cached_server_fn)(context,
 276                                                                          srv);
 277                                 return NULL;
 278                         }
 279
 280                         /*
 281                          * We don't need to renegotiate encryption
 282                          * here as the encryption context is not per
 283                          * tid.
 284                          */
 285
 286                         if (!cli_send_tconX(srv->cli, share, "?????",
 287                                             *pp_password,
 288                                             strlen(*pp_password)+1)) {
 289
 290                                 errno = SMBC_errno(context, srv->cli);
 291                                 cli_shutdown(srv->cli);
 292                                 srv->cli = NULL;
 293                                 (context->cache.remove_cached_server_fn)(context,
 294                                                                          srv);
 295                                 srv = NULL;
 296                         }
 297
 298                         /*
 299                          * Regenerate the dev value since it's based on both
 300                          * server and share
 301                          */
 302                         if (srv) {
 303                                 srv->dev = (dev_t)(str_checksum(server) ^
 304                                                    str_checksum(share));
 305                         }
 306                 }
 307         }
 308
 309         /* If we have a connection... */
 310         if (srv) {
 311
 312                 /* ... then we're done here.  Give 'em what they came for. */
 313                 return srv;
 314         }
 315
 316         /* If we're not asked to connect when a connection doesn't exist... */
 317         if (! connect_if_not_found) {
 318                 /* ... then we're done here. */
 319                 return NULL;
 320         }
 321
 322         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 323                 errno = ENOMEM;
 324                 return NULL;
 325         }
 326
 327         make_nmb_name(&calling, context->config.netbios_name, 0x0);
 328         make_nmb_name(&called , server, 0x20);
 329
 330         DEBUG(4,("SMBC_server: server_n=[%s] server=[%s]\n", server_n, server));
 331
 332         DEBUG(4,(" -> server_n=[%s] server=[%s]\n", server_n, server));
 333
 334 again:
 335
 336         zero_addr(&ss);
 337
 338         /* have to open a new connection */
 339         if ((c = cli_initialise()) == NULL) {
 340                 errno = ENOMEM;
 341                 return NULL;
 342         }
 343
 344         if (context->flags.bits & SMB_CTX_FLAG_USE_KERBEROS) {
 345                 c->use_kerberos = True;
 346         }
 347         if (context->flags.bits & SMB_CTX_FLAG_FALLBACK_AFTER_KERBEROS) {
 348                 c->fallback_after_kerberos = True;
 349         }
 350
 351         c->timeout = context->config.timeout;
 352
 353         /*
 354          * Force use of port 139 for first try if share is $IPC, empty, or
 355          * null, so browse lists can work
 356          */
 357         if (share == NULL || *share == '\0' || strcmp(share, "IPC$") == 0) {
 358                 port_try_first = 139;
 359                 port_try_next = 445;
 360         } else {
 361                 port_try_first = 445;
 362                 port_try_next = 139;
 363         }
 364
 365         c->port = port_try_first;
 366
 367         status = cli_connect(c, server_n, &ss);
 368         if (!NT_STATUS_IS_OK(status)) {
 369
 370                 /* First connection attempt failed.  Try alternate port. */
 371                 c->port = port_try_next;
 372
 373                 status = cli_connect(c, server_n, &ss);
 374                 if (!NT_STATUS_IS_OK(status)) {
 375                         cli_shutdown(c);
 376                         errno = ETIMEDOUT;
 377                         return NULL;
 378                 }
 379         }
 380
 381         if (!cli_session_request(c, &calling, &called)) {
 382                 cli_shutdown(c);
 383                 if (strcmp(called.name, "*SMBSERVER")) {
 384                         make_nmb_name(&called , "*SMBSERVER", 0x20);
 385                         goto again;
 386                 } else {  /* Try one more time, but ensure we don't loop */
 387
 388                         /* Only try this if server is an IP address ... */
 389
 390                         if (is_ipaddress(server) && !tried_reverse) {
 391                                 fstring remote_name;
 392                                 struct sockaddr_storage rem_ss;
 393
 394                                 if (!interpret_string_addr(&rem_ss, server,
 395                                                            NI_NUMERICHOST)) {
 396                                         DEBUG(4, ("Could not convert IP address "
 397                                                   "%s to struct sockaddr_storage\n",
 398                                                   server));
 399                                         errno = ETIMEDOUT;
 400                                         return NULL;
 401                                 }
 402
 403                                 tried_reverse++; /* Yuck */
 404
 405                                 if (name_status_find("*", 0, 0,
 406                                                      &rem_ss, remote_name)) {
 407                                         make_nmb_name(&called,
 408                                                       remote_name,
 409                                                       0x20);
 410                                         goto again;
 411                                 }
 412                         }
 413                 }
 414                 errno = ETIMEDOUT;
 415                 return NULL;
 416         }
 417
 418         DEBUG(4,(" session request ok\n"));
 419
 420         if (!cli_negprot(c)) {
 421                 cli_shutdown(c);
 422                 errno = ETIMEDOUT;
 423                 return NULL;
 424         }
 425
 426         username_used = *pp_username;
 427
 428         if (!NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 429                                                *pp_password,
 430                                                strlen(*pp_password),
 431                                                *pp_password,
 432                                                strlen(*pp_password),
 433                                                *pp_workgroup))) {
 434
 435                 /* Failed.  Try an anonymous login, if allowed by flags. */
 436                 username_used = "";
 437
 438                 if ((context->flags.bits &
 439                      SMBCCTX_FLAG_NO_AUTO_ANONYMOUS_LOGON) ||
 440                     !NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 441                                                        *pp_password, 1,
 442                                                        *pp_password, 0,
 443                                                        *pp_workgroup))) {
 444
 445                         cli_shutdown(c);
 446                         errno = EPERM;
 447                         return NULL;
 448                 }
 449         }
 450
 451         DEBUG(4,(" session setup ok\n"));
 452
 453         if (!cli_send_tconX(c, share, "?????",
 454                             *pp_password, strlen(*pp_password)+1)) {
 455                 errno = SMBC_errno(context, c);
 456                 cli_shutdown(c);
 457                 return NULL;
 458         }
 459
 460         DEBUG(4,(" tconx ok\n"));
 461
 462         if (context->internal->smb_encryption_level) {
 463                 /* Attempt UNIX smb encryption. */
 464                 if (!NT_STATUS_IS_OK(cli_force_encryption(c,
 465                                                           username_used,
 466                                                           *pp_password,
 467                                                           *pp_workgroup))) {
 468
 469                         /*
 470                          * context->smb_encryption_level == 1
 471                          * means don't fail if encryption can't be negotiated,
 472                          * == 2 means fail if encryption can't be negotiated.
 473                          */
 474
 475                         DEBUG(4,(" SMB encrypt failed\n"));
 476
 477                         if (context->internal->smb_encryption_level == 2) {
 478                                 cli_shutdown(c);
 479                                 errno = EPERM;
 480                                 return NULL;
 481                         }
 482                 }
 483                 DEBUG(4,(" SMB encrypt ok\n"));
 484         }
 485
 486         /*
 487          * Ok, we have got a nice connection
 488          * Let's allocate a server structure.
 489          */
 490
 491         srv = SMB_MALLOC_P(SMBCSRV);
 492         if (!srv) {
 493                 errno = ENOMEM;
 494                 goto failed;
 495         }
 496
 497         ZERO_STRUCTP(srv);
 498         srv->cli = c;
 499         srv->dev = (dev_t)(str_checksum(server) ^ str_checksum(share));
 500         srv->no_pathinfo = False;
 501         srv->no_pathinfo2 = False;
 502         srv->no_nt_session = False;
 503
 504         /* now add it to the cache (internal or external)  */
 505         /* Let the cache function set errno if it wants to */
 506         errno = 0;
 507         if ((context->cache.add_cached_server_fn)(context, srv,
 508                                                   server, share,
 509                                                   *pp_workgroup,
 510                                                   *pp_username)) {
 511                 int saved_errno = errno;
 512                 DEBUG(3, (" Failed to add server to cache\n"));
 513                 errno = saved_errno;
 514                 if (errno == 0) {
 515                         errno = ENOMEM;
 516                 }
 517                 goto failed;
 518         }
 519
 520         DEBUG(2, ("Server connect ok: //%s/%s: %p\n",
 521                   server, share, srv));
 522
 523         DLIST_ADD(context->internal->servers, srv);
 524         return srv;
 525
 526 failed:
 527         cli_shutdown(c);
 528         if (!srv) {
 529                 return NULL;
 530         }
 531
 532         SAFE_FREE(srv);
 533         return NULL;
 534 }
 535
 536 /*
 537  * Connect to a server for getting/setting attributes, possibly on an existing
 538  * connection.  This works similarly to SMBC_server().
 539  */
 540 SMBCSRV *
 541 SMBC_attr_server(TALLOC_CTX *ctx,
 542                  SMBCCTX *context,
 543                  const char *server,
 544                  const char *share,
 545                  char **pp_workgroup,
 546                  char **pp_username,
 547                  char **pp_password)
 548 {
 549         int flags;
 550         struct sockaddr_storage ss;
 551         struct cli_state *ipc_cli;
 552         struct rpc_pipe_client *pipe_hnd;
 553         NTSTATUS nt_status;
 554         SMBCSRV *ipc_srv=NULL;
 555
 556         /*
 557          * See if we've already created this special connection.  Reference
 558          * our "special" share name '*IPC$', which is an impossible real share
 559          * name due to the leading asterisk.
 560          */
 561         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
 562                                    pp_workgroup, pp_username, pp_password);
 563         if (!ipc_srv) {
 564
 565                 /* We didn't find a cached connection.  Get the password */
 566                 if (!*pp_password || (*pp_password)[0] == '\0') {
 567                         /* ... then retrieve it now. */
 568                         SMBC_call_auth_fn(ctx, context, server, share,
 569                                           pp_workgroup,
 570                                           pp_username,
 571                                           pp_password);
 572                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 573                                 errno = ENOMEM;
 574                                 return NULL;
 575                         }
 576                 }
 577
 578                 flags = 0;
 579                 if (context->flags.bits & SMB_CTX_FLAG_USE_KERBEROS) {
 580                         flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
 581                 }
 582
 583                 zero_addr(&ss);
 584                 nt_status = cli_full_connection(&ipc_cli,
 585                                                 global_myname(), server,
 586                                                 &ss, 0, "IPC$", "?????",
 587                                                 *pp_username,
 588                                                 *pp_workgroup,
 589                                                 *pp_password,
 590                                                 flags,
 591                                                 Undefined, NULL);
 592                 if (! NT_STATUS_IS_OK(nt_status)) {
 593                         DEBUG(1,("cli_full_connection failed! (%s)\n",
 594                                  nt_errstr(nt_status)));
 595                         errno = ENOTSUP;
 596                         return NULL;
 597                 }
 598
 599                 if (context->internal->smb_encryption_level) {
 600                         /* Attempt UNIX smb encryption. */
 601                         if (!NT_STATUS_IS_OK(cli_force_encryption(ipc_cli,
 602                                                                   *pp_username,
 603                                                                   *pp_password,
 604                                                                   *pp_workgroup))) {
 605
 606                                 /*
 607                                  * context->smb_encryption_level ==
 608                                  * 1 means don't fail if encryption can't be
 609                                  * negotiated, == 2 means fail if encryption
 610                                  * can't be negotiated.
 611                                  */
 612
 613                                 DEBUG(4,(" SMB encrypt failed on IPC$\n"));
 614
 615                                 if (context->internal->smb_encryption_level == 2) {
 616                                         cli_shutdown(ipc_cli);
 617                                         errno = EPERM;
 618                                         return NULL;
 619                                 }
 620                         }
 621                         DEBUG(4,(" SMB encrypt ok on IPC$\n"));
 622                 }
 623
 624                 ipc_srv = SMB_MALLOC_P(SMBCSRV);
 625                 if (!ipc_srv) {
 626                         errno = ENOMEM;
 627                         cli_shutdown(ipc_cli);
 628                         return NULL;
 629                 }
 630
 631                 ZERO_STRUCTP(ipc_srv);
 632                 ipc_srv->cli = ipc_cli;
 633
 634                 pipe_hnd = cli_rpc_pipe_open_noauth(ipc_srv->cli,
 635                                                     PI_LSARPC,
 636                                                     &nt_status);
 637                 if (!pipe_hnd) {
 638                         DEBUG(1, ("cli_nt_session_open fail!\n"));
 639                         errno = ENOTSUP;
 640                         cli_shutdown(ipc_srv->cli);
 641                         free(ipc_srv);
 642                         return NULL;
 643                 }
 644
 645                 /*
 646                  * Some systems don't support
 647                  * SEC_RIGHTS_MAXIMUM_ALLOWED, but NT sends 0x2000000
 648                  * so we might as well do it too.
 649                  */
 650
 651                 nt_status = rpccli_lsa_open_policy(
 652                         pipe_hnd,
 653                         talloc_tos(),
 654                         True,
 655                         GENERIC_EXECUTE_ACCESS,
 656                         &ipc_srv->pol);
 657
 658                 if (!NT_STATUS_IS_OK(nt_status)) {
 659                         errno = SMBC_errno(context, ipc_srv->cli);
 660                         cli_shutdown(ipc_srv->cli);
 661                         return NULL;
 662                 }
 663
 664                 /* now add it to the cache (internal or external) */
 665
 666                 errno = 0;      /* let cache function set errno if it likes */
 667                 if ((context->cache.add_cached_server_fn)(context, ipc_srv,
 668                                                           server,
 669                                                           "*IPC$",
 670                                                           *pp_workgroup,
 671                                                           *pp_username)) {
 672                         DEBUG(3, (" Failed to add server to cache\n"));
 673                         if (errno == 0) {
 674                                 errno = ENOMEM;
 675                         }
 676                         cli_shutdown(ipc_srv->cli);
 677                         free(ipc_srv);
 678                         return NULL;
 679                 }
 680
 681                 DLIST_ADD(context->internal->servers, ipc_srv);
 682         }
 683
 684         return ipc_srv;
 685 }