source3/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         smbc_getFunctionRemoveCachedServer(context)(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         smbc_getFunctionAuthData(context)(server, share,
 110                                           workgroup, sizeof(workgroup),
 111                                           username, sizeof(username),
 112                                           password, sizeof(password));
 113
 114         TALLOC_FREE(*pp_workgroup);
 115         TALLOC_FREE(*pp_username);
 116         TALLOC_FREE(*pp_password);
 117
 118         *pp_workgroup = talloc_strdup(ctx, workgroup);
 119         *pp_username = talloc_strdup(ctx, username);
 120         *pp_password = talloc_strdup(ctx, password);
 121 }
 122
 123
 124 void
 125 SMBC_get_auth_data(const char *server, const char *share,
 126                    char *workgroup_buf, int workgroup_buf_len,
 127                    char *username_buf, int username_buf_len,
 128                    char *password_buf, int password_buf_len)
 129 {
 130         /* Default function just uses provided data.  Nothing to do. */
 131 }
 132
 133
 134
 135 SMBCSRV *
 136 SMBC_find_server(TALLOC_CTX *ctx,
 137                  SMBCCTX *context,
 138                  const char *server,
 139                  const char *share,
 140                  char **pp_workgroup,
 141                  char **pp_username,
 142                  char **pp_password)
 143 {
 144         SMBCSRV *srv;
 145         int auth_called = 0;
 146
 147 check_server_cache:
 148
 149         srv = smbc_getFunctionGetCachedServer(context)(context,
 150                                                        server, share,
 151                                                        *pp_workgroup,
 152                                                        *pp_username);
 153
 154         if (!auth_called && !srv && (!*pp_username || !(*pp_username)[0] ||
 155                                      !*pp_password || !(*pp_password)[0])) {
 156                 SMBC_call_auth_fn(ctx, context, server, share,
 157                                   pp_workgroup, pp_username, pp_password);
 158
 159                 if (!pp_workgroup || !pp_username || !pp_password) {
 160                         return NULL;
 161                 }
 162
 163                 /*
 164                  * However, smbc_auth_fn may have picked up info relating to
 165                  * an existing connection, so try for an existing connection
 166                  * again ...
 167                  */
 168                 auth_called = 1;
 169                 goto check_server_cache;
 170
 171         }
 172
 173         if (srv) {
 174                 if (smbc_getFunctionCheckServer(context)(context, srv)) {
 175                         /*
 176                          * This server is no good anymore
 177                          * Try to remove it and check for more possible
 178                          * servers in the cache
 179                          */
 180                         if (smbc_getFunctionRemoveUnusedServer(context)(context,
 181                                                                         srv)) {
 182                                 /*
 183                                  * We could not remove the server completely,
 184                                  * remove it from the cache so we will not get
 185                                  * it again. It will be removed when the last
 186                                  * file/dir is closed.
 187                                  */
 188                                 smbc_getFunctionRemoveCachedServer(context)(context,
 189                                                                             srv);
 190                         }
 191
 192                         /*
 193                          * Maybe there are more cached connections to this
 194                          * server
 195                          */
 196                         goto check_server_cache;
 197                 }
 198
 199                 return srv;
 200         }
 201
 202         return NULL;
 203 }
 204
 205 /*
 206  * Connect to a server, possibly on an existing connection
 207  *
 208  * Here, what we want to do is: If the server and username
 209  * match an existing connection, reuse that, otherwise, establish a
 210  * new connection.
 211  *
 212  * If we have to create a new connection, call the auth_fn to get the
 213  * info we need, unless the username and password were passed in.
 214  */
 215
 216 SMBCSRV *
 217 SMBC_server(TALLOC_CTX *ctx,
 218             SMBCCTX *context,
 219             bool connect_if_not_found,
 220             const char *server,
 221             const char *share,
 222             char **pp_workgroup,
 223             char **pp_username,
 224             char **pp_password)
 225 {
 226         SMBCSRV *srv=NULL;
 227         struct cli_state *c;
 228         struct nmb_name called, calling;
 229         const char *server_n = server;
 230         struct sockaddr_storage ss;
 231         int tried_reverse = 0;
 232         int port_try_first;
 233         int port_try_next;
 234         const char *username_used;
 235         NTSTATUS status;
 236
 237         zero_addr(&ss);
 238         ZERO_STRUCT(c);
 239
 240         if (server[0] == 0) {
 241                 errno = EPERM;
 242                 return NULL;
 243         }
 244
 245         /* Look for a cached connection */
 246         srv = SMBC_find_server(ctx, context, server, share,
 247                                pp_workgroup, pp_username, pp_password);
 248
 249         /*
 250          * If we found a connection and we're only allowed one share per
 251          * server...
 252          */
 253         if (srv &&
 254             *share != '\0' &&
 255             smbc_getOptionOneSharePerServer(context)) {
 256
 257                 /*
 258                  * ... then if there's no current connection to the share,
 259                  * connect to it.  SMBC_find_server(), or rather the function
 260                  * pointed to by context->get_cached_srv_fn which
 261                  * was called by SMBC_find_server(), will have issued a tree
 262                  * disconnect if the requested share is not the same as the
 263                  * one that was already connected.
 264                  */
 265                 if (srv->cli->cnum == (uint16) -1) {
 266                         /* Ensure we have accurate auth info */
 267                         SMBC_call_auth_fn(ctx, context, server, share,
 268                                           pp_workgroup,
 269                                           pp_username,
 270                                           pp_password);
 271
 272                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 273                                 errno = ENOMEM;
 274                                 cli_shutdown(srv->cli);
 275                                 srv->cli = NULL;
 276                                 smbc_getFunctionRemoveCachedServer(context)(context,
 277                                                                             srv);
 278                                 return NULL;
 279                         }
 280
 281                         /*
 282                          * We don't need to renegotiate encryption
 283                          * here as the encryption context is not per
 284                          * tid.
 285                          */
 286
 287                         if (!cli_send_tconX(srv->cli, share, "?????",
 288                                             *pp_password,
 289                                             strlen(*pp_password)+1)) {
 290
 291                                 errno = SMBC_errno(context, srv->cli);
 292                                 cli_shutdown(srv->cli);
 293                                 srv->cli = NULL;
 294                                 smbc_getFunctionRemoveCachedServer(context)(context,
 295                                                                             srv);
 296                                 srv = NULL;
 297                         }
 298
 299                         /*
 300                          * Regenerate the dev value since it's based on both
 301                          * server and share
 302                          */
 303                         if (srv) {
 304                                 srv->dev = (dev_t)(str_checksum(server) ^
 305                                                    str_checksum(share));
 306                         }
 307                 }
 308         }
 309
 310         /* If we have a connection... */
 311         if (srv) {
 312
 313                 /* ... then we're done here.  Give 'em what they came for. */
 314                 return srv;
 315         }
 316
 317         /* If we're not asked to connect when a connection doesn't exist... */
 318         if (! connect_if_not_found) {
 319                 /* ... then we're done here. */
 320                 return NULL;
 321         }
 322
 323         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 324                 errno = ENOMEM;
 325                 return NULL;
 326         }
 327
 328         make_nmb_name(&calling, smbc_getNetbiosName(context), 0x0);
 329         make_nmb_name(&called , server, 0x20);
 330
 331         DEBUG(4,("SMBC_server: server_n=[%s] server=[%s]\n", server_n, server));
 332
 333         DEBUG(4,(" -> server_n=[%s] server=[%s]\n", server_n, server));
 334
 335 again:
 336
 337         zero_addr(&ss);
 338
 339         /* have to open a new connection */
 340         if ((c = cli_initialise()) == NULL) {
 341                 errno = ENOMEM;
 342                 return NULL;
 343         }
 344
 345         if (smbc_getOptionUseKerberos(context)) {
 346                 c->use_kerberos = True;
 347         }
 348
 349         if (smbc_getOptionFallbackAfterKerberos(context)) {
 350                 c->fallback_after_kerberos = True;
 351         }
 352
 353         c->timeout = smbc_getTimeout(context);
 354
 355         /*
 356          * Force use of port 139 for first try if share is $IPC, empty, or
 357          * null, so browse lists can work
 358          */
 359         if (share == NULL || *share == '\0' || strcmp(share, "IPC$") == 0) {
 360                 port_try_first = 139;
 361                 port_try_next = 445;
 362         } else {
 363                 port_try_first = 445;
 364                 port_try_next = 139;
 365         }
 366
 367         c->port = port_try_first;
 368
 369         status = cli_connect(c, server_n, &ss);
 370         if (!NT_STATUS_IS_OK(status)) {
 371
 372                 /* First connection attempt failed.  Try alternate port. */
 373                 c->port = port_try_next;
 374
 375                 status = cli_connect(c, server_n, &ss);
 376                 if (!NT_STATUS_IS_OK(status)) {
 377                         cli_shutdown(c);
 378                         errno = ETIMEDOUT;
 379                         return NULL;
 380                 }
 381         }
 382
 383         if (!cli_session_request(c, &calling, &called)) {
 384                 cli_shutdown(c);
 385                 if (strcmp(called.name, "*SMBSERVER")) {
 386                         make_nmb_name(&called , "*SMBSERVER", 0x20);
 387                         goto again;
 388                 } else {  /* Try one more time, but ensure we don't loop */
 389
 390                         /* Only try this if server is an IP address ... */
 391
 392                         if (is_ipaddress(server) && !tried_reverse) {
 393                                 fstring remote_name;
 394                                 struct sockaddr_storage rem_ss;
 395
 396                                 if (!interpret_string_addr(&rem_ss, server,
 397                                                            NI_NUMERICHOST)) {
 398                                         DEBUG(4, ("Could not convert IP address "
 399                                                   "%s to struct sockaddr_storage\n",
 400                                                   server));
 401                                         errno = ETIMEDOUT;
 402                                         return NULL;
 403                                 }
 404
 405                                 tried_reverse++; /* Yuck */
 406
 407                                 if (name_status_find("*", 0, 0,
 408                                                      &rem_ss, remote_name)) {
 409                                         make_nmb_name(&called,
 410                                                       remote_name,
 411                                                       0x20);
 412                                         goto again;
 413                                 }
 414                         }
 415                 }
 416                 errno = ETIMEDOUT;
 417                 return NULL;
 418         }
 419
 420         DEBUG(4,(" session request ok\n"));
 421
 422         if (!cli_negprot(c)) {
 423                 cli_shutdown(c);
 424                 errno = ETIMEDOUT;
 425                 return NULL;
 426         }
 427
 428         username_used = *pp_username;
 429
 430         if (!NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 431                                                *pp_password,
 432                                                strlen(*pp_password),
 433                                                *pp_password,
 434                                                strlen(*pp_password),
 435                                                *pp_workgroup))) {
 436
 437                 /* Failed.  Try an anonymous login, if allowed by flags. */
 438                 username_used = "";
 439
 440                 if (smbc_getOptionNoAutoAnonymousLogin(context) ||
 441                     !NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 442                                                        *pp_password, 1,
 443                                                        *pp_password, 0,
 444                                                        *pp_workgroup))) {
 445
 446                         cli_shutdown(c);
 447                         errno = EPERM;
 448                         return NULL;
 449                 }
 450         }
 451
 452         DEBUG(4,(" session setup ok\n"));
 453
 454         if (!cli_send_tconX(c, share, "?????",
 455                             *pp_password, strlen(*pp_password)+1)) {
 456                 errno = SMBC_errno(context, c);
 457                 cli_shutdown(c);
 458                 return NULL;
 459         }
 460
 461         DEBUG(4,(" tconx ok\n"));
 462
 463         if (context->internal->smb_encryption_level) {
 464                 /* Attempt UNIX smb encryption. */
 465                 if (!NT_STATUS_IS_OK(cli_force_encryption(c,
 466                                                           username_used,
 467                                                           *pp_password,
 468                                                           *pp_workgroup))) {
 469
 470                         /*
 471                          * context->smb_encryption_level == 1
 472                          * means don't fail if encryption can't be negotiated,
 473                          * == 2 means fail if encryption can't be negotiated.
 474                          */
 475
 476                         DEBUG(4,(" SMB encrypt failed\n"));
 477
 478                         if (context->internal->smb_encryption_level == 2) {
 479                                 cli_shutdown(c);
 480                                 errno = EPERM;
 481                                 return NULL;
 482                         }
 483                 }
 484                 DEBUG(4,(" SMB encrypt ok\n"));
 485         }
 486
 487         /*
 488          * Ok, we have got a nice connection
 489          * Let's allocate a server structure.
 490          */
 491
 492         srv = SMB_MALLOC_P(SMBCSRV);
 493         if (!srv) {
 494                 errno = ENOMEM;
 495                 goto failed;
 496         }
 497
 498         ZERO_STRUCTP(srv);
 499         srv->cli = c;
 500         srv->dev = (dev_t)(str_checksum(server) ^ str_checksum(share));
 501         srv->no_pathinfo = False;
 502         srv->no_pathinfo2 = False;
 503         srv->no_nt_session = False;
 504
 505         /* now add it to the cache (internal or external)  */
 506         /* Let the cache function set errno if it wants to */
 507         errno = 0;
 508         if (smbc_getFunctionAddCachedServer(context)(context, srv,
 509                                                      server, share,
 510                                                      *pp_workgroup,
 511                                                      *pp_username)) {
 512                 int saved_errno = errno;
 513                 DEBUG(3, (" Failed to add server to cache\n"));
 514                 errno = saved_errno;
 515                 if (errno == 0) {
 516                         errno = ENOMEM;
 517                 }
 518                 goto failed;
 519         }
 520
 521         DEBUG(2, ("Server connect ok: //%s/%s: %p\n",
 522                   server, share, srv));
 523
 524         DLIST_ADD(context->internal->servers, srv);
 525         return srv;
 526
 527 failed:
 528         cli_shutdown(c);
 529         if (!srv) {
 530                 return NULL;
 531         }
 532
 533         SAFE_FREE(srv);
 534         return NULL;
 535 }
 536
 537 /*
 538  * Connect to a server for getting/setting attributes, possibly on an existing
 539  * connection.  This works similarly to SMBC_server().
 540  */
 541 SMBCSRV *
 542 SMBC_attr_server(TALLOC_CTX *ctx,
 543                  SMBCCTX *context,
 544                  const char *server,
 545                  const char *share,
 546                  char **pp_workgroup,
 547                  char **pp_username,
 548                  char **pp_password)
 549 {
 550         int flags;
 551         struct sockaddr_storage ss;
 552         struct cli_state *ipc_cli;
 553         struct rpc_pipe_client *pipe_hnd;
 554         NTSTATUS nt_status;
 555         SMBCSRV *ipc_srv=NULL;
 556
 557         /*
 558          * See if we've already created this special connection.  Reference
 559          * our "special" share name '*IPC$', which is an impossible real share
 560          * name due to the leading asterisk.
 561          */
 562         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
 563                                    pp_workgroup, pp_username, pp_password);
 564         if (!ipc_srv) {
 565
 566                 /* We didn't find a cached connection.  Get the password */
 567                 if (!*pp_password || (*pp_password)[0] == '\0') {
 568                         /* ... then retrieve it now. */
 569                         SMBC_call_auth_fn(ctx, context, server, share,
 570                                           pp_workgroup,
 571                                           pp_username,
 572                                           pp_password);
 573                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 574                                 errno = ENOMEM;
 575                                 return NULL;
 576                         }
 577                 }
 578
 579                 flags = 0;
 580                 if (smbc_getOptionUseKerberos(context)) {
 581                         flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
 582                 }
 583
 584                 zero_addr(&ss);
 585                 nt_status = cli_full_connection(&ipc_cli,
 586                                                 global_myname(), server,
 587                                                 &ss, 0, "IPC$", "?????",
 588                                                 *pp_username,
 589                                                 *pp_workgroup,
 590                                                 *pp_password,
 591                                                 flags,
 592                                                 Undefined, NULL);
 593                 if (! NT_STATUS_IS_OK(nt_status)) {
 594                         DEBUG(1,("cli_full_connection failed! (%s)\n",
 595                                  nt_errstr(nt_status)));
 596                         errno = ENOTSUP;
 597                         return NULL;
 598                 }
 599
 600                 if (context->internal->smb_encryption_level) {
 601                         /* Attempt UNIX smb encryption. */
 602                         if (!NT_STATUS_IS_OK(cli_force_encryption(ipc_cli,
 603                                                                   *pp_username,
 604                                                                   *pp_password,
 605                                                                   *pp_workgroup))) {
 606
 607                                 /*
 608                                  * context->smb_encryption_level ==
 609                                  * 1 means don't fail if encryption can't be
 610                                  * negotiated, == 2 means fail if encryption
 611                                  * can't be negotiated.
 612                                  */
 613
 614                                 DEBUG(4,(" SMB encrypt failed on IPC$\n"));
 615
 616                                 if (context->internal->smb_encryption_level == 2) {
 617                                         cli_shutdown(ipc_cli);
 618                                         errno = EPERM;
 619                                         return NULL;
 620                                 }
 621                         }
 622                         DEBUG(4,(" SMB encrypt ok on IPC$\n"));
 623                 }
 624
 625                 ipc_srv = SMB_MALLOC_P(SMBCSRV);
 626                 if (!ipc_srv) {
 627                         errno = ENOMEM;
 628                         cli_shutdown(ipc_cli);
 629                         return NULL;
 630                 }
 631
 632                 ZERO_STRUCTP(ipc_srv);
 633                 ipc_srv->cli = ipc_cli;
 634
 635                 pipe_hnd = cli_rpc_pipe_open_noauth(ipc_srv->cli,
 636                                                     PI_LSARPC,
 637                                                     &nt_status);
 638                 if (!pipe_hnd) {
 639                         DEBUG(1, ("cli_nt_session_open fail!\n"));
 640                         errno = ENOTSUP;
 641                         cli_shutdown(ipc_srv->cli);
 642                         free(ipc_srv);
 643                         return NULL;
 644                 }
 645
 646                 /*
 647                  * Some systems don't support
 648                  * SEC_RIGHTS_MAXIMUM_ALLOWED, but NT sends 0x2000000
 649                  * so we might as well do it too.
 650                  */
 651
 652                 nt_status = rpccli_lsa_open_policy(
 653                         pipe_hnd,
 654                         talloc_tos(),
 655                         True,
 656                         GENERIC_EXECUTE_ACCESS,
 657                         &ipc_srv->pol);
 658
 659                 if (!NT_STATUS_IS_OK(nt_status)) {
 660                         errno = SMBC_errno(context, ipc_srv->cli);
 661                         cli_shutdown(ipc_srv->cli);
 662                         return NULL;
 663                 }
 664
 665                 /* now add it to the cache (internal or external) */
 666
 667                 errno = 0;      /* let cache function set errno if it likes */
 668                 if (smbc_getFunctionAddCachedServer(context)(context, ipc_srv,
 669                                                              server,
 670                                                              "*IPC$",
 671                                                              *pp_workgroup,
 672                                                              *pp_username)) {
 673                         DEBUG(3, (" Failed to add server to cache\n"));
 674                         if (errno == 0) {
 675                                 errno = ENOMEM;
 676                         }
 677                         cli_shutdown(ipc_srv->cli);
 678                         free(ipc_srv);
 679                         return NULL;
 680                 }
 681
 682                 DLIST_ADD(context->internal->servers, ipc_srv);
 683         }
 684
 685         return ipc_srv;
 686 }