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->initialized || !srv) {
  62                 return 1;
  63         }
  64
  65         /* Check all open files/directories for a relation with this server */
  66         for (file = context->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->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->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, pp_username, pp_password);
 268
 269                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 270                                 errno = ENOMEM;
 271                                 cli_shutdown(srv->cli);
 272                                 srv->cli = NULL;
 273                                 (context->cache.remove_cached_server_fn)(context,
 274                                                                          srv);
 275                                 return NULL;
 276                         }
 277
 278                         /*
 279                          * We don't need to renegotiate encryption
 280                          * here as the encryption context is not per
 281                          * tid.
 282                          */
 283
 284                         if (!cli_send_tconX(srv->cli, share, "?????",
 285                                                 *pp_password,
 286                                                 strlen(*pp_password)+1)) {
 287
 288                                 errno = SMBC_errno(context, srv->cli);
 289                                 cli_shutdown(srv->cli);
 290                                 srv->cli = NULL;
 291                                 (context->cache.remove_cached_server_fn)(context,
 292                                                                          srv);
 293                                 srv = NULL;
 294                         }
 295
 296                         /*
 297                          * Regenerate the dev value since it's based on both
 298                          * server and share
 299                          */
 300                         if (srv) {
 301                                 srv->dev = (dev_t)(str_checksum(server) ^
 302                                                    str_checksum(share));
 303                         }
 304                 }
 305         }
 306
 307         /* If we have a connection... */
 308         if (srv) {
 309
 310                 /* ... then we're done here.  Give 'em what they came for. */
 311                 return srv;
 312         }
 313
 314         /* If we're not asked to connect when a connection doesn't exist... */
 315         if (! connect_if_not_found) {
 316                 /* ... then we're done here. */
 317                 return NULL;
 318         }
 319
 320         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 321                 errno = ENOMEM;
 322                 return NULL;
 323         }
 324
 325         make_nmb_name(&calling, context->netbios_name, 0x0);
 326         make_nmb_name(&called , server, 0x20);
 327
 328         DEBUG(4,("SMBC_server: server_n=[%s] server=[%s]\n", server_n, server));
 329
 330         DEBUG(4,(" -> server_n=[%s] server=[%s]\n", server_n, server));
 331
 332  again:
 333
 334         zero_addr(&ss);
 335
 336         /* have to open a new connection */
 337         if ((c = cli_initialise()) == NULL) {
 338                 errno = ENOMEM;
 339                 return NULL;
 340         }
 341
 342         if (context->use_kerberos) {
 343                 c->use_kerberos = True;
 344         }
 345         if (context->fallback_after_kerberos) {
 346                 c->fallback_after_kerberos = True;
 347         }
 348
 349         c->timeout = context->timeout;
 350
 351         /*
 352          * Force use of port 139 for first try if share is $IPC, empty, or
 353          * null, so browse lists can work
 354          */
 355         if (share == NULL || *share == '\0' || strcmp(share, "IPC$") == 0) {
 356                 port_try_first = 139;
 357                 port_try_next = 445;
 358         } else {
 359                 port_try_first = 445;
 360                 port_try_next = 139;
 361         }
 362
 363         c->port = port_try_first;
 364
 365         status = cli_connect(c, server_n, &ss);
 366         if (!NT_STATUS_IS_OK(status)) {
 367
 368                 /* First connection attempt failed.  Try alternate port. */
 369                 c->port = port_try_next;
 370
 371                 status = cli_connect(c, server_n, &ss);
 372                 if (!NT_STATUS_IS_OK(status)) {
 373                         cli_shutdown(c);
 374                         errno = ETIMEDOUT;
 375                         return NULL;
 376                 }
 377         }
 378
 379         if (!cli_session_request(c, &calling, &called)) {
 380                 cli_shutdown(c);
 381                 if (strcmp(called.name, "*SMBSERVER")) {
 382                         make_nmb_name(&called , "*SMBSERVER", 0x20);
 383                         goto again;
 384                 } else {  /* Try one more time, but ensure we don't loop */
 385
 386                         /* Only try this if server is an IP address ... */
 387
 388                         if (is_ipaddress(server) && !tried_reverse) {
 389                                 fstring remote_name;
 390                                 struct sockaddr_storage rem_ss;
 391
 392                                 if (!interpret_string_addr(&rem_ss, server,
 393                                                         NI_NUMERICHOST)) {
 394                                         DEBUG(4, ("Could not convert IP address "
 395                                                 "%s to struct sockaddr_storage\n",
 396                                                 server));
 397                                         errno = ETIMEDOUT;
 398                                         return NULL;
 399                                 }
 400
 401                                 tried_reverse++; /* Yuck */
 402
 403                                 if (name_status_find("*", 0, 0, &rem_ss, remote_name)) {
 404                                         make_nmb_name(&called, remote_name, 0x20);
 405                                         goto again;
 406                                 }
 407                         }
 408                 }
 409                 errno = ETIMEDOUT;
 410                 return NULL;
 411         }
 412
 413         DEBUG(4,(" session request ok\n"));
 414
 415         if (!cli_negprot(c)) {
 416                 cli_shutdown(c);
 417                 errno = ETIMEDOUT;
 418                 return NULL;
 419         }
 420
 421         username_used = *pp_username;
 422
 423         if (!NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 424                                                *pp_password, strlen(*pp_password),
 425                                                *pp_password, strlen(*pp_password),
 426                                                *pp_workgroup))) {
 427
 428                 /* Failed.  Try an anonymous login, if allowed by flags. */
 429                 username_used = "";
 430
 431                 if (context->no_auto_anonymous_login ||
 432                     !NT_STATUS_IS_OK(cli_session_setup(c, username_used,
 433                                                        *pp_password, 1,
 434                                                        *pp_password, 0,
 435                                                        *pp_workgroup))) {
 436
 437                         cli_shutdown(c);
 438                         errno = EPERM;
 439                         return NULL;
 440                 }
 441         }
 442
 443         DEBUG(4,(" session setup ok\n"));
 444
 445         if (!cli_send_tconX(c, share, "?????",
 446                             *pp_password, strlen(*pp_password)+1)) {
 447                 errno = SMBC_errno(context, c);
 448                 cli_shutdown(c);
 449                 return NULL;
 450         }
 451
 452         DEBUG(4,(" tconx ok\n"));
 453
 454         if (context->smb_encryption_level) {
 455                 /* Attempt UNIX smb encryption. */
 456                 if (!NT_STATUS_IS_OK(cli_force_encryption(c,
 457                                                 username_used,
 458                                                 *pp_password,
 459                                                 *pp_workgroup))) {
 460
 461                         /*
 462                          * context->smb_encryption_level == 1
 463                          * means don't fail if encryption can't be negotiated,
 464                          * == 2 means fail if encryption can't be negotiated.
 465                          */
 466
 467                         DEBUG(4,(" SMB encrypt failed\n"));
 468
 469                         if (context->smb_encryption_level == 2) {
 470                                 cli_shutdown(c);
 471                                 errno = EPERM;
 472                                 return NULL;
 473                         }
 474                 }
 475                 DEBUG(4,(" SMB encrypt ok\n"));
 476         }
 477
 478         /*
 479          * Ok, we have got a nice connection
 480          * Let's allocate a server structure.
 481          */
 482
 483         srv = SMB_MALLOC_P(SMBCSRV);
 484         if (!srv) {
 485                 errno = ENOMEM;
 486                 goto failed;
 487         }
 488
 489         ZERO_STRUCTP(srv);
 490         srv->cli = c;
 491         srv->dev = (dev_t)(str_checksum(server) ^ str_checksum(share));
 492         srv->no_pathinfo = False;
 493         srv->no_pathinfo2 = False;
 494         srv->no_nt_session = False;
 495
 496         /* now add it to the cache (internal or external)  */
 497         /* Let the cache function set errno if it wants to */
 498         errno = 0;
 499         if ((context->cache.add_cached_server_fn)(context, srv,
 500                                                   server, share,
 501                                                   *pp_workgroup,
 502                                                   *pp_username)) {
 503                 int saved_errno = errno;
 504                 DEBUG(3, (" Failed to add server to cache\n"));
 505                 errno = saved_errno;
 506                 if (errno == 0) {
 507                         errno = ENOMEM;
 508                 }
 509                 goto failed;
 510         }
 511
 512         DEBUG(2, ("Server connect ok: //%s/%s: %p\n",
 513                   server, share, srv));
 514
 515         DLIST_ADD(context->servers, srv);
 516         return srv;
 517
 518  failed:
 519         cli_shutdown(c);
 520         if (!srv) {
 521                 return NULL;
 522         }
 523
 524         SAFE_FREE(srv);
 525         return NULL;
 526 }
 527
 528 /*
 529  * Connect to a server for getting/setting attributes, possibly on an existing
 530  * connection.  This works similarly to SMBC_server().
 531  */
 532 SMBCSRV *
 533 SMBC_attr_server(TALLOC_CTX *ctx,
 534                  SMBCCTX *context,
 535                  const char *server,
 536                  const char *share,
 537                  char **pp_workgroup,
 538                  char **pp_username,
 539                  char **pp_password)
 540 {
 541         int flags;
 542         struct sockaddr_storage ss;
 543         struct cli_state *ipc_cli;
 544         struct rpc_pipe_client *pipe_hnd;
 545         NTSTATUS nt_status;
 546         SMBCSRV *ipc_srv=NULL;
 547
 548         /*
 549          * See if we've already created this special connection.  Reference
 550          * our "special" share name '*IPC$', which is an impossible real share
 551          * name due to the leading asterisk.
 552          */
 553         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
 554                               pp_workgroup, pp_username, pp_password);
 555         if (!ipc_srv) {
 556
 557                 /* We didn't find a cached connection.  Get the password */
 558                 if (!*pp_password || (*pp_password)[0] == '\0') {
 559                         /* ... then retrieve it now. */
 560                         SMBC_call_auth_fn(ctx, context, server, share,
 561                                 pp_workgroup, pp_username, pp_password);
 562                         if (!*pp_workgroup || !*pp_username || !*pp_password) {
 563                                 errno = ENOMEM;
 564                                 return NULL;
 565                         }
 566                 }
 567
 568                 flags = 0;
 569                 if (context->use_kerberos) {
 570                         flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
 571                 }
 572
 573                 zero_addr(&ss);
 574                 nt_status = cli_full_connection(&ipc_cli,
 575                                                 global_myname(), server,
 576                                                 &ss, 0, "IPC$", "?????",
 577                                                 *pp_username,
 578                                                 *pp_workgroup,
 579                                                 *pp_password,
 580                                                 flags,
 581                                                 Undefined, NULL);
 582                 if (! NT_STATUS_IS_OK(nt_status)) {
 583                         DEBUG(1,("cli_full_connection failed! (%s)\n",
 584                                  nt_errstr(nt_status)));
 585                         errno = ENOTSUP;
 586                         return NULL;
 587                 }
 588
 589                 if (context->smb_encryption_level) {
 590                         /* Attempt UNIX smb encryption. */
 591                         if (!NT_STATUS_IS_OK(cli_force_encryption(ipc_cli,
 592                                                 *pp_username,
 593                                                 *pp_password,
 594                                                 *pp_workgroup))) {
 595
 596                                 /*
 597                                  * context->smb_encryption_level ==
 598                                  * 1 means don't fail if encryption can't be
 599                                  * negotiated, == 2 means fail if encryption
 600                                  * can't be negotiated.
 601                                  */
 602
 603                                 DEBUG(4,(" SMB encrypt failed on IPC$\n"));
 604
 605                                 if (context->smb_encryption_level == 2) {
 606                                         cli_shutdown(ipc_cli);
 607                                         errno = EPERM;
 608                                         return NULL;
 609                                 }
 610                         }
 611                         DEBUG(4,(" SMB encrypt ok on IPC$\n"));
 612                 }
 613
 614                 ipc_srv = SMB_MALLOC_P(SMBCSRV);
 615                 if (!ipc_srv) {
 616                         errno = ENOMEM;
 617                         cli_shutdown(ipc_cli);
 618                         return NULL;
 619                 }
 620
 621                 ZERO_STRUCTP(ipc_srv);
 622                 ipc_srv->cli = ipc_cli;
 623
 624                 pipe_hnd = cli_rpc_pipe_open_noauth(ipc_srv->cli,
 625                                                     PI_LSARPC,
 626                                                     &nt_status);
 627                 if (!pipe_hnd) {
 628                     DEBUG(1, ("cli_nt_session_open fail!\n"));
 629                     errno = ENOTSUP;
 630                     cli_shutdown(ipc_srv->cli);
 631                     free(ipc_srv);
 632                     return NULL;
 633                 }
 634
 635                 /*
 636                  * Some systems don't support
 637                  * SEC_RIGHTS_MAXIMUM_ALLOWED, but NT sends 0x2000000
 638                  * so we might as well do it too.
 639                  */
 640
 641                 nt_status = rpccli_lsa_open_policy(
 642                     pipe_hnd,
 643                     talloc_tos(),
 644                     True,
 645                     GENERIC_EXECUTE_ACCESS,
 646                     &ipc_srv->pol);
 647
 648                 if (!NT_STATUS_IS_OK(nt_status)) {
 649                     errno = SMBC_errno(context, ipc_srv->cli);
 650                     cli_shutdown(ipc_srv->cli);
 651                     return NULL;
 652                 }
 653
 654                 /* now add it to the cache (internal or external) */
 655
 656                 errno = 0;      /* let cache function set errno if it likes */
 657                 if ((context->cache.add_cached_server_fn)(context, ipc_srv,
 658                                                           server,
 659                                                           "*IPC$",
 660                                                           *pp_workgroup,
 661                                                           *pp_username)) {
 662                         DEBUG(3, (" Failed to add server to cache\n"));
 663                         if (errno == 0) {
 664                                 errno = ENOMEM;
 665                         }
 666                         cli_shutdown(ipc_srv->cli);
 667                         free(ipc_srv);
 668                         return NULL;
 669                 }
 670
 671                 DLIST_ADD(context->servers, ipc_srv);
 672         }
 673
 674         return ipc_srv;
 675 }