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         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         smbc_get_auth_data_with_context_fn auth_with_context_fn;
 105
 106         strlcpy(workgroup, *pp_workgroup, sizeof(workgroup));
 107         strlcpy(username, *pp_username, sizeof(username));
 108         strlcpy(password, *pp_password, sizeof(password));
 109
 110         /* See if there's an authentication with context function provided */
 111         auth_with_context_fn = smbc_getFunctionAuthDataWithContext(context);
 112         if (auth_with_context_fn)
 113         {
 114             (* auth_with_context_fn)(context,
 115                                      server, share,
 116                                      workgroup, sizeof(workgroup),
 117                                      username, sizeof(username),
 118                                      password, sizeof(password));
 119         }
 120         else
 121         {
 122             smbc_getFunctionAuthData(context)(server, share,
 123                                               workgroup, sizeof(workgroup),
 124                                               username, sizeof(username),
 125                                               password, sizeof(password));
 126         }
 127
 128         TALLOC_FREE(*pp_workgroup);
 129         TALLOC_FREE(*pp_username);
 130         TALLOC_FREE(*pp_password);
 131
 132         *pp_workgroup = talloc_strdup(ctx, workgroup);
 133         *pp_username = talloc_strdup(ctx, username);
 134         *pp_password = talloc_strdup(ctx, password);
 135 }
 136
 137
 138 void
 139 SMBC_get_auth_data(const char *server, const char *share,
 140                    char *workgroup_buf, int workgroup_buf_len,
 141                    char *username_buf, int username_buf_len,
 142                    char *password_buf, int password_buf_len)
 143 {
 144         /* Default function just uses provided data.  Nothing to do. */
 145 }
 146
 147
 148
 149 SMBCSRV *
 150 SMBC_find_server(TALLOC_CTX *ctx,
 151                  SMBCCTX *context,
 152                  const char *server,
 153                  const char *share,
 154                  char **pp_workgroup,
 155                  char **pp_username,
 156                  char **pp_password)
 157 {
 158         SMBCSRV *srv;
 159         int auth_called = 0;
 160
 161         if (!pp_workgroup || !pp_username || !pp_password) {
 162                 return NULL;
 163         }
 164
 165 check_server_cache:
 166
 167         srv = smbc_getFunctionGetCachedServer(context)(context,
 168                                                        server, share,
 169                                                        *pp_workgroup,
 170                                                        *pp_username);
 171
 172         if (!auth_called && !srv && (!*pp_username || !(*pp_username)[0] ||
 173                                      !*pp_password || !(*pp_password)[0])) {
 174                 SMBC_call_auth_fn(ctx, context, server, share,
 175                                   pp_workgroup, pp_username, pp_password);
 176
 177                 /*
 178                  * However, smbc_auth_fn may have picked up info relating to
 179                  * an existing connection, so try for an existing connection
 180                  * again ...
 181                  */
 182                 auth_called = 1;
 183                 goto check_server_cache;
 184
 185         }
 186
 187         if (srv) {
 188                 if (smbc_getFunctionCheckServer(context)(context, srv)) {
 189                         /*
 190                          * This server is no good anymore
 191                          * Try to remove it and check for more possible
 192                          * servers in the cache
 193                          */
 194                         if (smbc_getFunctionRemoveUnusedServer(context)(context,
 195                                                                         srv)) {
 196                                 /*
 197                                  * We could not remove the server completely,
 198                                  * remove it from the cache so we will not get
 199                                  * it again. It will be removed when the last
 200                                  * file/dir is closed.
 201                                  */
 202                                 smbc_getFunctionRemoveCachedServer(context)(context,
 203                                                                             srv);
 204                         }
 205
 206                         /*
 207                          * Maybe there are more cached connections to this
 208                          * server
 209                          */
 210                         goto check_server_cache;
 211                 }
 212
 213                 return srv;
 214         }
 215
 216         return NULL;
 217 }
 218
 219 /*
 220  * Connect to a server, possibly on an existing connection
 221  *
 222  * Here, what we want to do is: If the server and username
 223  * match an existing connection, reuse that, otherwise, establish a
 224  * new connection.
 225  *
 226  * If we have to create a new connection, call the auth_fn to get the
 227  * info we need, unless the username and password were passed in.
 228  */
 229
 230 SMBCSRV *
 231 SMBC_server(TALLOC_CTX *ctx,
 232             SMBCCTX *context,
 233             bool connect_if_not_found,
 234             const char *server,
 235             const char *share,
 236             char **pp_workgroup,
 237             char **pp_username,
 238             char **pp_password)
 239 {
 240         SMBCSRV *srv=NULL;
 241         struct cli_state *c;
 242         struct nmb_name called, calling;
 243         const char *server_n = server;
 244         struct sockaddr_storage ss;
 245         int tried_reverse = 0;
 246         int port_try_first;
 247         int port_try_next;
 248         const char *username_used;
 249         NTSTATUS status;
 250
 251         zero_addr(&ss);
 252         ZERO_STRUCT(c);
 253
 254         if (server[0] == 0) {
 255                 errno = EPERM;
 256                 return NULL;
 257         }
 258
 259         /* Look for a cached connection */
 260         srv = SMBC_find_server(ctx, context, server, share,
 261                                pp_workgroup, pp_username, pp_password);
 262
 263         /*
 264          * If we found a connection and we're only allowed one share per
 265          * server...
 266          */
 267         if (srv &&
 268             *share != '\0' &&
 269             smbc_getOptionOneSharePerServer(context)) {
 270
 271                 /*
 272                  * ... then if there's no current connection to the share,
 273                  * connect to it.  SMBC_find_server(), or rather the function
 274                  * pointed to by context->get_cached_srv_fn which
 275                  * was called by SMBC_find_server(), will have issued a tree
 276                  * disconnect if the requested share is not the same as the
 277                  * one that was already connected.
 278                  */
 279                 if (srv->cli->cnum == (uint16) -1) {
 280                         /* Ensure we have accurate auth info */
 281                         SMBC_call_auth_fn(ctx, context, server, share,
 282                                           pp_workgroup,
 283                                           pp_username,
 284                                           pp_password);
 285
 286                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 287                                 errno = ENOMEM;
 288                                 cli_shutdown(srv->cli);
 289                                 srv->cli = NULL;
 290                                 smbc_getFunctionRemoveCachedServer(context)(context,
 291                                                                             srv);
 292                                 return NULL;
 293                         }
 294
 295                         /*
 296                          * We don't need to renegotiate encryption
 297                          * here as the encryption context is not per
 298                          * tid.
 299                          */
 300
 301                         if (!cli_send_tconX(srv->cli, share, "?????",
 302                                             *pp_password,
 303                                             strlen(*pp_password)+1)) {
 304
 305                                 errno = SMBC_errno(context, srv->cli);
 306                                 cli_shutdown(srv->cli);
 307                                 srv->cli = NULL;
 308                                 smbc_getFunctionRemoveCachedServer(context)(context,
 309                                                                             srv);
 310                                 srv = NULL;
 311                         }
 312
 313                         /*
 314                          * Regenerate the dev value since it's based on both
 315                          * server and share
 316                          */
 317                         if (srv) {
 318                                 srv->dev = (dev_t)(str_checksum(server) ^
 319                                                    str_checksum(share));
 320                         }
 321                 }
 322         }
 323
 324         /* If we have a connection... */
 325         if (srv) {
 326
 327                 /* ... then we're done here.  Give 'em what they came for. */
 328                 return srv;
 329         }
 330
 331         /* If we're not asked to connect when a connection doesn't exist... */
 332         if (! connect_if_not_found) {
 333                 /* ... then we're done here. */
 334                 return NULL;
 335         }
 336
 337         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 338                 errno = ENOMEM;
 339                 return NULL;
 340         }
 341
 342         make_nmb_name(&calling, smbc_getNetbiosName(context), 0x0);
 343         make_nmb_name(&called , server, 0x20);
 344
 345         DEBUG(4,("SMBC_server: server_n=[%s] server=[%s]\n", server_n, server));
 346
 347         DEBUG(4,(" -> server_n=[%s] server=[%s]\n", server_n, server));
 348
 349 again:
 350
 351         zero_addr(&ss);
 352
 353         /* have to open a new connection */
 354         if ((c = cli_initialise()) == NULL) {
 355                 errno = ENOMEM;
 356                 return NULL;
 357         }
 358
 359         if (smbc_getOptionUseKerberos(context)) {
 360                 c->use_kerberos = True;
 361         }
 362
 363         if (smbc_getOptionFallbackAfterKerberos(context)) {
 364                 c->fallback_after_kerberos = True;
 365         }
 366
 367         c->timeout = smbc_getTimeout(context);
 368
 369         /*
 370          * Force use of port 139 for first try if share is $IPC, empty, or
 371          * null, so browse lists can work
 372          */
 373         if (share == NULL || *share == '\0' || strcmp(share, "IPC$") == 0) {
 374                 port_try_first = 139;
 375                 port_try_next = 445;
 376         } else {
 377                 port_try_first = 445;
 378                 port_try_next = 139;
 379         }
 380
 381         c->port = port_try_first;
 382
 383         status = cli_connect(c, server_n, &ss);
 384         if (!NT_STATUS_IS_OK(status)) {
 385
 386                 /* First connection attempt failed.  Try alternate port. */
 387                 c->port = port_try_next;
 388
 389                 status = cli_connect(c, server_n, &ss);
 390                 if (!NT_STATUS_IS_OK(status)) {
 391                         cli_shutdown(c);
 392                         errno = ETIMEDOUT;
 393                         return NULL;
 394                 }
 395         }
 396
 397         if (!cli_session_request(c, &calling, &called)) {
 398                 cli_shutdown(c);
 399                 if (strcmp(called.name, "*SMBSERVER")) {
 400                         make_nmb_name(&called , "*SMBSERVER", 0x20);
 401                         goto again;
 402                 } else {  /* Try one more time, but ensure we don't loop */
 403
 404                         /* Only try this if server is an IP address ... */
 405
 406                         if (is_ipaddress(server) && !tried_reverse) {
 407                                 fstring remote_name;
 408                                 struct sockaddr_storage rem_ss;
 409
 410                                 if (!interpret_string_addr(&rem_ss, server,
 411                                                            NI_NUMERICHOST)) {
 412                                         DEBUG(4, ("Could not convert IP address "
 413                                                   "%s to struct sockaddr_storage\n",
 414                                                   server));
 415                                         errno = ETIMEDOUT;
 416                                         return NULL;
 417                                 }
 418
 419                                 tried_reverse++; /* Yuck */
 420
 421                                 if (name_status_find("*", 0, 0,
 422                                                      &rem_ss, remote_name)) {
 423                                         make_nmb_name(&called,
 424                                                       remote_name,
 425                                                       0x20);
 426                                         goto again;
 427                                 }
 428                         }
 429                 }
 430                 errno = ETIMEDOUT;
 431                 return NULL;
 432         }
 433
 434         DEBUG(4,(" session request ok\n"));
 435
 436         if (!cli_negprot(c)) {
 437                 cli_shutdown(c);
 438                 errno = ETIMEDOUT;
 439                 return NULL;
 440         }
 441
 442         username_used = *pp_username;
 443
 444         if (!NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 445                                                *pp_password,
 446                                                strlen(*pp_password),
 447                                                *pp_password,
 448                                                strlen(*pp_password),
 449                                                *pp_workgroup))) {
 450
 451                 /* Failed.  Try an anonymous login, if allowed by flags. */
 452                 username_used = "";
 453
 454                 if (smbc_getOptionNoAutoAnonymousLogin(context) ||
 455                     !NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 456                                                        *pp_password, 1,
 457                                                        *pp_password, 0,
 458                                                        *pp_workgroup))) {
 459
 460                         cli_shutdown(c);
 461                         errno = EPERM;
 462                         return NULL;
 463                 }
 464         }
 465
 466         DEBUG(4,(" session setup ok\n"));
 467
 468         if (!cli_send_tconX(c, share, "?????",
 469                             *pp_password, strlen(*pp_password)+1)) {
 470                 errno = SMBC_errno(context, c);
 471                 cli_shutdown(c);
 472                 return NULL;
 473         }
 474
 475         DEBUG(4,(" tconx ok\n"));
 476
 477         if (context->internal->smb_encryption_level) {
 478                 /* Attempt UNIX smb encryption. */
 479                 if (!NT_STATUS_IS_OK(cli_force_encryption(c,
 480                                                           username_used,
 481                                                           *pp_password,
 482                                                           *pp_workgroup))) {
 483
 484                         /*
 485                          * context->smb_encryption_level == 1
 486                          * means don't fail if encryption can't be negotiated,
 487                          * == 2 means fail if encryption can't be negotiated.
 488                          */
 489
 490                         DEBUG(4,(" SMB encrypt failed\n"));
 491
 492                         if (context->internal->smb_encryption_level == 2) {
 493                                 cli_shutdown(c);
 494                                 errno = EPERM;
 495                                 return NULL;
 496                         }
 497                 }
 498                 DEBUG(4,(" SMB encrypt ok\n"));
 499         }
 500
 501         /*
 502          * Ok, we have got a nice connection
 503          * Let's allocate a server structure.
 504          */
 505
 506         srv = SMB_MALLOC_P(SMBCSRV);
 507         if (!srv) {
 508                 errno = ENOMEM;
 509                 goto failed;
 510         }
 511
 512         ZERO_STRUCTP(srv);
 513         srv->cli = c;
 514         srv->dev = (dev_t)(str_checksum(server) ^ str_checksum(share));
 515         srv->no_pathinfo = False;
 516         srv->no_pathinfo2 = False;
 517         srv->no_nt_session = False;
 518
 519         /* now add it to the cache (internal or external)  */
 520         /* Let the cache function set errno if it wants to */
 521         errno = 0;
 522         if (smbc_getFunctionAddCachedServer(context)(context, srv,
 523                                                      server, share,
 524                                                      *pp_workgroup,
 525                                                      *pp_username)) {
 526                 int saved_errno = errno;
 527                 DEBUG(3, (" Failed to add server to cache\n"));
 528                 errno = saved_errno;
 529                 if (errno == 0) {
 530                         errno = ENOMEM;
 531                 }
 532                 goto failed;
 533         }
 534
 535         DEBUG(2, ("Server connect ok: //%s/%s: %p\n",
 536                   server, share, srv));
 537
 538         DLIST_ADD(context->internal->servers, srv);
 539         return srv;
 540
 541 failed:
 542         cli_shutdown(c);
 543         if (!srv) {
 544                 return NULL;
 545         }
 546
 547         SAFE_FREE(srv);
 548         return NULL;
 549 }
 550
 551 /*
 552  * Connect to a server for getting/setting attributes, possibly on an existing
 553  * connection.  This works similarly to SMBC_server().
 554  */
 555 SMBCSRV *
 556 SMBC_attr_server(TALLOC_CTX *ctx,
 557                  SMBCCTX *context,
 558                  const char *server,
 559                  const char *share,
 560                  char **pp_workgroup,
 561                  char **pp_username,
 562                  char **pp_password)
 563 {
 564         int flags;
 565         struct sockaddr_storage ss;
 566         struct cli_state *ipc_cli;
 567         struct rpc_pipe_client *pipe_hnd;
 568         NTSTATUS nt_status;
 569         SMBCSRV *ipc_srv=NULL;
 570
 571         /*
 572          * See if we've already created this special connection.  Reference
 573          * our "special" share name '*IPC$', which is an impossible real share
 574          * name due to the leading asterisk.
 575          */
 576         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
 577                                    pp_workgroup, pp_username, pp_password);
 578         if (!ipc_srv) {
 579
 580                 /* We didn't find a cached connection.  Get the password */
 581                 if (!*pp_password || (*pp_password)[0] == '\0') {
 582                         /* ... then retrieve it now. */
 583                         SMBC_call_auth_fn(ctx, context, server, share,
 584                                           pp_workgroup,
 585                                           pp_username,
 586                                           pp_password);
 587                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 588                                 errno = ENOMEM;
 589                                 return NULL;
 590                         }
 591                 }
 592
 593                 flags = 0;
 594                 if (smbc_getOptionUseKerberos(context)) {
 595                         flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
 596                 }
 597
 598                 zero_addr(&ss);
 599                 nt_status = cli_full_connection(&ipc_cli,
 600                                                 global_myname(), server,
 601                                                 &ss, 0, "IPC$", "?????",
 602                                                 *pp_username,
 603                                                 *pp_workgroup,
 604                                                 *pp_password,
 605                                                 flags,
 606                                                 Undefined, NULL);
 607                 if (! NT_STATUS_IS_OK(nt_status)) {
 608                         DEBUG(1,("cli_full_connection failed! (%s)\n",
 609                                  nt_errstr(nt_status)));
 610                         errno = ENOTSUP;
 611                         return NULL;
 612                 }
 613
 614                 if (context->internal->smb_encryption_level) {
 615                         /* Attempt UNIX smb encryption. */
 616                         if (!NT_STATUS_IS_OK(cli_force_encryption(ipc_cli,
 617                                                                   *pp_username,
 618                                                                   *pp_password,
 619                                                                   *pp_workgroup))) {
 620
 621                                 /*
 622                                  * context->smb_encryption_level ==
 623                                  * 1 means don't fail if encryption can't be
 624                                  * negotiated, == 2 means fail if encryption
 625                                  * can't be negotiated.
 626                                  */
 627
 628                                 DEBUG(4,(" SMB encrypt failed on IPC$\n"));
 629
 630                                 if (context->internal->smb_encryption_level == 2) {
 631                                         cli_shutdown(ipc_cli);
 632                                         errno = EPERM;
 633                                         return NULL;
 634                                 }
 635                         }
 636                         DEBUG(4,(" SMB encrypt ok on IPC$\n"));
 637                 }
 638
 639                 ipc_srv = SMB_MALLOC_P(SMBCSRV);
 640                 if (!ipc_srv) {
 641                         errno = ENOMEM;
 642                         cli_shutdown(ipc_cli);
 643                         return NULL;
 644                 }
 645
 646                 ZERO_STRUCTP(ipc_srv);
 647                 ipc_srv->cli = ipc_cli;
 648
 649                 nt_status = cli_rpc_pipe_open_noauth(
 650                         ipc_srv->cli, &ndr_table_lsarpc.syntax_id, &pipe_hnd);
 651                 if (!NT_STATUS_IS_OK(nt_status)) {
 652                         DEBUG(1, ("cli_nt_session_open fail!\n"));
 653                         errno = ENOTSUP;
 654                         cli_shutdown(ipc_srv->cli);
 655                         free(ipc_srv);
 656                         return NULL;
 657                 }
 658
 659                 /*
 660                  * Some systems don't support
 661                  * SEC_RIGHTS_MAXIMUM_ALLOWED, but NT sends 0x2000000
 662                  * so we might as well do it too.
 663                  */
 664
 665                 nt_status = rpccli_lsa_open_policy(
 666                         pipe_hnd,
 667                         talloc_tos(),
 668                         True,
 669                         GENERIC_EXECUTE_ACCESS,
 670                         &ipc_srv->pol);
 671
 672                 if (!NT_STATUS_IS_OK(nt_status)) {
 673                         errno = SMBC_errno(context, ipc_srv->cli);
 674                         cli_shutdown(ipc_srv->cli);
 675                         return NULL;
 676                 }
 677
 678                 /* now add it to the cache (internal or external) */
 679
 680                 errno = 0;      /* let cache function set errno if it likes */
 681                 if (smbc_getFunctionAddCachedServer(context)(context, ipc_srv,
 682                                                              server,
 683                                                              "*IPC$",
 684                                                              *pp_workgroup,
 685                                                              *pp_username)) {
 686                         DEBUG(3, (" Failed to add server to cache\n"));
 687                         if (errno == 0) {
 688                                 errno = ENOMEM;
 689                         }
 690                         cli_shutdown(ipc_srv->cli);
 691                         free(ipc_srv);
 692                         return NULL;
 693                 }
 694
 695                 DLIST_ADD(context->internal->servers, ipc_srv);
 696         }
 697
 698         return ipc_srv;
 699 }