source3/libsmb/clidfs.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    client connect/disconnect routines
   4    Copyright (C) Andrew Tridgell                  1994-1998
   5    Copyright (C) Gerald (Jerry) Carter            2004
   6    Copyright (C) Jeremy Allison                   2007-2009
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "libsmb/libsmb.h"
  24 #include "libsmb/clirap.h"
  25 #include "msdfs.h"
  26 #include "trans2.h"
  27 #include "libsmb/nmblib.h"
  28 #include "../libcli/smb/smbXcli_base.h"
  29 #include "auth/credentials/credentials.h"
  30 #include "lib/param/param.h"
  31
  32 /********************************************************************
  33  Important point.
  34
  35  DFS paths are *always* of the form \server\share\<pathname> (the \ characters
  36  are not C escaped here).
  37
  38  - but if we're using POSIX paths then <pathname> may contain
  39    '/' separators, not '\\' separators. So cope with '\\' or '/'
  40    as a separator when looking at the pathname part.... JRA.
  41 ********************************************************************/
  42
  43 /********************************************************************
  44  Ensure a connection is encrypted.
  45 ********************************************************************/
  46
  47 static NTSTATUS cli_cm_force_encryption_creds(struct cli_state *c,
  48                                               struct cli_credentials *creds,
  49                                               const char *sharename)
  50 {
  51         uint16_t major, minor;
  52         uint32_t caplow, caphigh;
  53         NTSTATUS status;
  54         bool temp_ipc = false;
  55
  56         if (smbXcli_conn_protocol(c->conn) >= PROTOCOL_SMB2_02) {
  57                 status = smb2cli_session_encryption_on(c->smb2.session);
  58                 if (NT_STATUS_EQUAL(status,NT_STATUS_NOT_SUPPORTED)) {
  59                         d_printf("Encryption required and "
  60                                 "server doesn't support "
  61                                 "SMB3 encryption - failing connect\n");
  62                 } else if (!NT_STATUS_IS_OK(status)) {
  63                         d_printf("Encryption required and "
  64                                 "setup failed with error %s.\n",
  65                                 nt_errstr(status));
  66                 }
  67                 return status;
  68         }
  69
  70         if (!SERVER_HAS_UNIX_CIFS(c)) {
  71                 d_printf("Encryption required and "
  72                         "server that doesn't support "
  73                         "UNIX extensions - failing connect\n");
  74                 return NT_STATUS_NOT_SUPPORTED;
  75         }
  76
  77         if (c->smb1.tcon == NULL) {
  78                 status = cli_tree_connect_creds(c, "IPC$", "IPC", creds);
  79                 if (!NT_STATUS_IS_OK(status)) {
  80                         d_printf("Encryption required and "
  81                                 "can't connect to IPC$ to check "
  82                                 "UNIX CIFS extensions.\n");
  83                         return NT_STATUS_UNKNOWN_REVISION;
  84                 }
  85                 temp_ipc = true;
  86         }
  87
  88         status = cli_unix_extensions_version(c, &major, &minor, &caplow,
  89                                              &caphigh);
  90         if (!NT_STATUS_IS_OK(status)) {
  91                 d_printf("Encryption required and "
  92                         "can't get UNIX CIFS extensions "
  93                         "version from server.\n");
  94                 if (temp_ipc) {
  95                         cli_tdis(c);
  96                 }
  97                 return NT_STATUS_UNKNOWN_REVISION;
  98         }
  99
 100         if (!(caplow & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)) {
 101                 d_printf("Encryption required and "
 102                         "share %s doesn't support "
 103                         "encryption.\n", sharename);
 104                 if (temp_ipc) {
 105                         cli_tdis(c);
 106                 }
 107                 return NT_STATUS_UNSUPPORTED_COMPRESSION;
 108         }
 109
 110         status = cli_smb1_setup_encryption(c, creds);
 111         if (!NT_STATUS_IS_OK(status)) {
 112                 d_printf("Encryption required and "
 113                         "setup failed with error %s.\n",
 114                         nt_errstr(status));
 115                 if (temp_ipc) {
 116                         cli_tdis(c);
 117                 }
 118                 return status;
 119         }
 120
 121         if (temp_ipc) {
 122                 cli_tdis(c);
 123         }
 124         return NT_STATUS_OK;
 125 }
 126
 127 /********************************************************************
 128  Return a connection to a server.
 129 ********************************************************************/
 130
 131 static NTSTATUS do_connect(TALLOC_CTX *ctx,
 132                                         const char *server,
 133                                         const char *share,
 134                                         struct cli_credentials *creds,
 135                                         const struct sockaddr_storage *dest_ss,
 136                                         int port,
 137                                         int name_type,
 138                                         struct cli_state **pcli)
 139 {
 140         struct cli_state *c = NULL;
 141         char *servicename;
 142         char *sharename;
 143         char *newserver, *newshare;
 144         NTSTATUS status;
 145         int flags = 0;
 146         enum protocol_types protocol = PROTOCOL_NONE;
 147         enum smb_signing_setting signing_state =
 148                 cli_credentials_get_smb_signing(creds);
 149         enum smb_encryption_setting encryption_state =
 150                 cli_credentials_get_smb_encryption(creds);
 151
 152         if (encryption_state >= SMB_ENCRYPTION_DESIRED) {
 153                 signing_state = SMB_SIGNING_REQUIRED;
 154         }
 155
 156         /* make a copy so we don't modify the global string 'service' */
 157         servicename = talloc_strdup(ctx,share);
 158         if (!servicename) {
 159                 return NT_STATUS_NO_MEMORY;
 160         }
 161         sharename = servicename;
 162         if (*sharename == '\\') {
 163                 sharename += 2;
 164                 if (server == NULL) {
 165                         server = sharename;
 166                 }
 167                 sharename = strchr_m(sharename,'\\');
 168                 if (!sharename) {
 169                         return NT_STATUS_NO_MEMORY;
 170                 }
 171                 *sharename = 0;
 172                 sharename++;
 173         }
 174         if (server == NULL) {
 175                 return NT_STATUS_INVALID_PARAMETER;
 176         }
 177
 178         status = cli_connect_nb(
 179                 server, dest_ss, port, name_type, NULL,
 180                 signing_state,
 181                 flags, &c);
 182
 183         if (!NT_STATUS_IS_OK(status)) {
 184                 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
 185                         DBG_ERR("NetBIOS support disabled, unable to connect\n");
 186                 }
 187
 188                 DBG_WARNING("Connection to %s failed (Error %s)\n",
 189                             server,
 190                             nt_errstr(status));
 191                 return status;
 192         }
 193
 194         DEBUG(4,(" session request ok\n"));
 195
 196         status = smbXcli_negprot(c->conn, c->timeout,
 197                                  lp_client_min_protocol(),
 198                                  lp_client_max_protocol());
 199
 200         if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
 201                 d_printf("Protocol negotiation (with timeout %d ms) timed out against server %s\n",
 202                          c->timeout,
 203                          smbXcli_conn_remote_name(c->conn));
 204                 cli_shutdown(c);
 205         } else if (!NT_STATUS_IS_OK(status)) {
 206                 d_printf("Protocol negotiation to server %s (for a protocol between %s and %s) failed: %s\n",
 207                          smbXcli_conn_remote_name(c->conn),
 208                          lpcfg_get_smb_protocol(lp_client_min_protocol()),
 209                          lpcfg_get_smb_protocol(lp_client_max_protocol()),
 210                          nt_errstr(status));
 211                 cli_shutdown(c);
 212                 return status;
 213         }
 214         protocol = smbXcli_conn_protocol(c->conn);
 215         DEBUG(4,(" negotiated dialect[%s] against server[%s]\n",
 216                  smb_protocol_types_string(protocol),
 217                  smbXcli_conn_remote_name(c->conn)));
 218
 219         if (protocol >= PROTOCOL_SMB2_02) {
 220                 /* Ensure we ask for some initial credits. */
 221                 smb2cli_conn_set_max_credits(c->conn, DEFAULT_SMB2_MAX_CREDITS);
 222         }
 223
 224         status = cli_session_setup_creds(c, creds);
 225         if (!NT_STATUS_IS_OK(status)) {
 226                 /* If a password was not supplied then
 227                  * try again with a null username. */
 228                 if (encryption_state == SMB_ENCRYPTION_REQUIRED ||
 229                         smbXcli_conn_signing_mandatory(c->conn) ||
 230                         cli_credentials_authentication_requested(creds) ||
 231                         cli_credentials_is_anonymous(creds) ||
 232                         !NT_STATUS_IS_OK(status = cli_session_setup_anon(c)))
 233                 {
 234                         d_printf("session setup failed: %s\n",
 235                                  nt_errstr(status));
 236                         if (NT_STATUS_EQUAL(status,
 237                                             NT_STATUS_MORE_PROCESSING_REQUIRED))
 238                                 d_printf("did you forget to run kinit?\n");
 239                         cli_shutdown(c);
 240                         return status;
 241                 }
 242                 d_printf("Anonymous login successful\n");
 243         }
 244
 245         if (!NT_STATUS_IS_OK(status)) {
 246                 DEBUG(10,("cli_init_creds() failed: %s\n", nt_errstr(status)));
 247                 cli_shutdown(c);
 248                 return status;
 249         }
 250
 251         DEBUG(4,(" session setup ok\n"));
 252
 253         if (encryption_state >= SMB_ENCRYPTION_DESIRED) {
 254                 status = cli_cm_force_encryption_creds(c,
 255                                                        creds,
 256                                                        sharename);
 257                 if (!NT_STATUS_IS_OK(status)) {
 258                         switch (encryption_state) {
 259                         case SMB_ENCRYPTION_DESIRED:
 260                                 break;
 261                         case SMB_ENCRYPTION_REQUIRED:
 262                         default:
 263                                 cli_shutdown(c);
 264                                 return status;
 265                         }
 266                 }
 267         }
 268
 269         /* here's the fun part....to support 'msdfs proxy' shares
 270            (on Samba or windows) we have to issues a TRANS_GET_DFS_REFERRAL
 271            here before trying to connect to the original share.
 272            cli_check_msdfs_proxy() will fail if it is a normal share. */
 273
 274         if (smbXcli_conn_dfs_supported(c->conn) &&
 275                         cli_check_msdfs_proxy(ctx, c, sharename,
 276                                 &newserver, &newshare,
 277                                 creds)) {
 278                 cli_shutdown(c);
 279                 return do_connect(ctx, newserver,
 280                                 newshare, creds,
 281                                 NULL, port, name_type, pcli);
 282         }
 283
 284         /* must be a normal share */
 285
 286         status = cli_tree_connect_creds(c, sharename, "?????", creds);
 287         if (!NT_STATUS_IS_OK(status)) {
 288                 d_printf("tree connect failed: %s\n", nt_errstr(status));
 289                 cli_shutdown(c);
 290                 return status;
 291         }
 292
 293         DEBUG(4,(" tconx ok\n"));
 294         *pcli = c;
 295         return NT_STATUS_OK;
 296 }
 297
 298 /********************************************************************
 299  Add a new connection to the list.
 300  referring_cli == NULL means a new initial connection.
 301 ********************************************************************/
 302
 303 static NTSTATUS cli_cm_connect(TALLOC_CTX *ctx,
 304                                struct cli_state *referring_cli,
 305                                const char *server,
 306                                const char *share,
 307                                struct cli_credentials *creds,
 308                                const struct sockaddr_storage *dest_ss,
 309                                int port,
 310                                int name_type,
 311                                struct cli_state **pcli)
 312 {
 313         struct cli_state *cli = NULL;
 314         NTSTATUS status;
 315
 316         status = do_connect(ctx, server, share,
 317                                 creds,
 318                                 dest_ss, port, name_type, &cli);
 319
 320         if (!NT_STATUS_IS_OK(status)) {
 321                 return status;
 322         }
 323
 324         /*
 325          * This can't happen, this test is to satisfy static
 326          * checkers (clang)
 327          */
 328         if (cli == NULL) {
 329                 return NT_STATUS_NO_MEMORY;
 330         }
 331
 332         /* Enter into the list. */
 333         if (referring_cli) {
 334                 DLIST_ADD_END(referring_cli, cli);
 335         }
 336
 337         if (referring_cli && referring_cli->requested_posix_capabilities) {
 338                 uint16_t major, minor;
 339                 uint32_t caplow, caphigh;
 340                 status = cli_unix_extensions_version(cli, &major, &minor,
 341                                                      &caplow, &caphigh);
 342                 if (NT_STATUS_IS_OK(status)) {
 343                         cli_set_unix_extensions_capabilities(cli,
 344                                         major, minor,
 345                                         caplow, caphigh);
 346                 }
 347         }
 348
 349         *pcli = cli;
 350         return NT_STATUS_OK;
 351 }
 352
 353 /********************************************************************
 354  Return a connection to a server on a particular share.
 355 ********************************************************************/
 356
 357 static struct cli_state *cli_cm_find(struct cli_state *cli,
 358                                 const char *server,
 359                                 const char *share)
 360 {
 361         struct cli_state *p;
 362
 363         if (cli == NULL) {
 364                 return NULL;
 365         }
 366
 367         /* Search to the start of the list. */
 368         for (p = cli; p; p = DLIST_PREV(p)) {
 369                 const char *remote_name =
 370                         smbXcli_conn_remote_name(p->conn);
 371
 372                 if (strequal(server, remote_name) &&
 373                                 strequal(share,p->share)) {
 374                         return p;
 375                 }
 376         }
 377
 378         /* Search to the end of the list. */
 379         for (p = cli->next; p; p = p->next) {
 380                 const char *remote_name =
 381                         smbXcli_conn_remote_name(p->conn);
 382
 383                 if (strequal(server, remote_name) &&
 384                                 strequal(share,p->share)) {
 385                         return p;
 386                 }
 387         }
 388
 389         return NULL;
 390 }
 391
 392 /****************************************************************************
 393  Open a client connection to a \\server\share.
 394 ****************************************************************************/
 395
 396 NTSTATUS cli_cm_open(TALLOC_CTX *ctx,
 397                      struct cli_state *referring_cli,
 398                      const char *server,
 399                      const char *share,
 400                      struct cli_credentials *creds,
 401                      const struct sockaddr_storage *dest_ss,
 402                      int port,
 403                      int name_type,
 404                      struct cli_state **pcli)
 405 {
 406         /* Try to reuse an existing connection in this list. */
 407         struct cli_state *c = cli_cm_find(referring_cli, server, share);
 408         NTSTATUS status;
 409
 410         if (c) {
 411                 *pcli = c;
 412                 return NT_STATUS_OK;
 413         }
 414
 415         if (creds == NULL) {
 416                 /* Can't do a new connection
 417                  * without auth info. */
 418                 d_printf("cli_cm_open() Unable to open connection [\\%s\\%s] "
 419                         "without client credentials\n",
 420                         server, share );
 421                 return NT_STATUS_INVALID_PARAMETER;
 422         }
 423
 424         status = cli_cm_connect(ctx,
 425                                 referring_cli,
 426                                 server,
 427                                 share,
 428                                 creds,
 429                                 dest_ss,
 430                                 port,
 431                                 name_type,
 432                                 &c);
 433         if (!NT_STATUS_IS_OK(status)) {
 434                 return status;
 435         }
 436         *pcli = c;
 437         return NT_STATUS_OK;
 438 }
 439
 440 /****************************************************************************
 441 ****************************************************************************/
 442
 443 void cli_cm_display(struct cli_state *cli)
 444 {
 445         int i;
 446
 447         for (i=0; cli; cli = cli->next,i++ ) {
 448                 d_printf("%d:\tserver=%s, share=%s\n",
 449                         i, smbXcli_conn_remote_name(cli->conn), cli->share);
 450         }
 451 }
 452
 453 /**********************************************************************
 454  split a dfs path into the server, share name, and extrapath components
 455 **********************************************************************/
 456
 457 static bool split_dfs_path(TALLOC_CTX *ctx,
 458                                 const char *nodepath,
 459                                 char **pp_server,
 460                                 char **pp_share,
 461                                 char **pp_extrapath)
 462 {
 463         char *p, *q;
 464         char *path;
 465
 466         *pp_server = NULL;
 467         *pp_share = NULL;
 468         *pp_extrapath = NULL;
 469
 470         path = talloc_strdup(ctx, nodepath);
 471         if (!path) {
 472                 goto fail;
 473         }
 474
 475         if ( path[0] != '\\' ) {
 476                 goto fail;
 477         }
 478
 479         p = strchr_m( path + 1, '\\' );
 480         if ( !p ) {
 481                 goto fail;
 482         }
 483
 484         *p = '\0';
 485         p++;
 486
 487         /* Look for any extra/deep path */
 488         q = strchr_m(p, '\\');
 489         if (q != NULL) {
 490                 *q = '\0';
 491                 q++;
 492                 *pp_extrapath = talloc_strdup(ctx, q);
 493         } else {
 494                 *pp_extrapath = talloc_strdup(ctx, "");
 495         }
 496         if (*pp_extrapath == NULL) {
 497                 goto fail;
 498         }
 499
 500         *pp_share = talloc_strdup(ctx, p);
 501         if (*pp_share == NULL) {
 502                 goto fail;
 503         }
 504
 505         *pp_server = talloc_strdup(ctx, &path[1]);
 506         if (*pp_server == NULL) {
 507                 goto fail;
 508         }
 509
 510         TALLOC_FREE(path);
 511         return true;
 512
 513 fail:
 514         TALLOC_FREE(*pp_share);
 515         TALLOC_FREE(*pp_extrapath);
 516         TALLOC_FREE(path);
 517         return false;
 518 }
 519
 520 /****************************************************************************
 521  Return the original path truncated at the directory component before
 522  the first wildcard character. Trust the caller to provide a NULL
 523  terminated string
 524 ****************************************************************************/
 525
 526 static char *clean_path(TALLOC_CTX *ctx, const char *path)
 527 {
 528         size_t len;
 529         char *p1, *p2, *p;
 530         char *path_out;
 531
 532         /* No absolute paths. */
 533         while (IS_DIRECTORY_SEP(*path)) {
 534                 path++;
 535         }
 536
 537         path_out = talloc_strdup(ctx, path);
 538         if (!path_out) {
 539                 return NULL;
 540         }
 541
 542         p1 = strchr_m(path_out, '*');
 543         p2 = strchr_m(path_out, '?');
 544
 545         if (p1 || p2) {
 546                 if (p1 && p2) {
 547                         p = MIN(p1,p2);
 548                 } else if (!p1) {
 549                         p = p2;
 550                 } else {
 551                         p = p1;
 552                 }
 553                 *p = '\0';
 554
 555                 /* Now go back to the start of this component. */
 556                 p1 = strrchr_m(path_out, '/');
 557                 p2 = strrchr_m(path_out, '\\');
 558                 p = MAX(p1,p2);
 559                 if (p) {
 560                         *p = '\0';
 561                 }
 562         }
 563
 564         /* Strip any trailing separator */
 565
 566         len = strlen(path_out);
 567         if ( (len > 0) && IS_DIRECTORY_SEP(path_out[len-1])) {
 568                 path_out[len-1] = '\0';
 569         }
 570
 571         return path_out;
 572 }
 573
 574 /****************************************************************************
 575 ****************************************************************************/
 576
 577 static char *cli_dfs_make_full_path(TALLOC_CTX *ctx,
 578                                         struct cli_state *cli,
 579                                         const char *dir)
 580 {
 581         char path_sep = '\\';
 582
 583         /* Ensure the extrapath doesn't start with a separator. */
 584         while (IS_DIRECTORY_SEP(*dir)) {
 585                 dir++;
 586         }
 587
 588         if (cli->requested_posix_capabilities & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
 589                 path_sep = '/';
 590         }
 591         return talloc_asprintf(ctx, "%c%s%c%s%c%s",
 592                         path_sep,
 593                         smbXcli_conn_remote_name(cli->conn),
 594                         path_sep,
 595                         cli->share,
 596                         path_sep,
 597                         dir);
 598 }
 599
 600 /********************************************************************
 601  Check if a path has already been converted to DFS.
 602 ********************************************************************/
 603
 604 bool cli_dfs_is_already_full_path(struct cli_state *cli, const char *path)
 605 {
 606         const char *server = smbXcli_conn_remote_name(cli->conn);
 607         size_t server_len = strlen(server);
 608         bool found_server = false;
 609         const char *share = cli->share;
 610         size_t share_len = strlen(share);
 611         bool found_share = false;
 612
 613         if (!IS_DIRECTORY_SEP(path[0])) {
 614                 return false;
 615         }
 616         path++;
 617         found_server = (strncasecmp_m(path, server, server_len) == 0);
 618         if (!found_server) {
 619                 return false;
 620         }
 621         path += server_len;
 622         if (!IS_DIRECTORY_SEP(path[0])) {
 623                 return false;
 624         }
 625         path++;
 626         found_share = (strncasecmp_m(path, share, share_len) == 0);
 627         if (!found_share) {
 628                 return false;
 629         }
 630         path += share_len;
 631         if (path[0] == '\0') {
 632                 return true;
 633         }
 634         if (IS_DIRECTORY_SEP(path[0])) {
 635                 return true;
 636         }
 637         return false;
 638 }
 639
 640 /********************************************************************
 641  Get the dfs referral link.
 642 ********************************************************************/
 643
 644 NTSTATUS cli_dfs_get_referral_ex(TALLOC_CTX *ctx,
 645                         struct cli_state *cli,
 646                         const char *path,
 647                         uint16_t max_referral_level,
 648                         struct client_dfs_referral **refs,
 649                         size_t *num_refs,
 650                         size_t *consumed)
 651 {
 652         unsigned int param_len = 0;
 653         uint16_t recv_flags2;
 654         uint8_t *param = NULL;
 655         uint8_t *rdata = NULL;
 656         char *p;
 657         char *endp;
 658         smb_ucs2_t *path_ucs;
 659         char *consumed_path = NULL;
 660         uint16_t consumed_ucs;
 661         uint16_t num_referrals;
 662         struct client_dfs_referral *referrals = NULL;
 663         NTSTATUS status;
 664         TALLOC_CTX *frame = talloc_stackframe();
 665
 666         *num_refs = 0;
 667         *refs = NULL;
 668
 669         param = talloc_array(talloc_tos(), uint8_t, 2);
 670         if (!param) {
 671                 status = NT_STATUS_NO_MEMORY;
 672                 goto out;
 673         }
 674         SSVAL(param, 0, max_referral_level);
 675
 676         param = trans2_bytes_push_str(param, smbXcli_conn_use_unicode(cli->conn),
 677                                       path, strlen(path)+1,
 678                                       NULL);
 679         if (!param) {
 680                 status = NT_STATUS_NO_MEMORY;
 681                 goto out;
 682         }
 683         param_len = talloc_get_size(param);
 684         path_ucs = (smb_ucs2_t *)&param[2];
 685
 686         if (smbXcli_conn_protocol(cli->conn) >= PROTOCOL_SMB2_02) {
 687                 DATA_BLOB in_input_buffer;
 688                 DATA_BLOB in_output_buffer = data_blob_null;
 689                 DATA_BLOB out_input_buffer = data_blob_null;
 690                 DATA_BLOB out_output_buffer = data_blob_null;
 691
 692                 in_input_buffer.data = param;
 693                 in_input_buffer.length = param_len;
 694
 695                 status = smb2cli_ioctl(cli->conn,
 696                                        cli->timeout,
 697                                        cli->smb2.session,
 698                                        cli->smb2.tcon,
 699                                        UINT64_MAX, /* in_fid_persistent */
 700                                        UINT64_MAX, /* in_fid_volatile */
 701                                        FSCTL_DFS_GET_REFERRALS,
 702                                        0, /* in_max_input_length */
 703                                        &in_input_buffer,
 704                                        CLI_BUFFER_SIZE, /* in_max_output_length */
 705                                        &in_output_buffer,
 706                                        SMB2_IOCTL_FLAG_IS_FSCTL,
 707                                        talloc_tos(),
 708                                        &out_input_buffer,
 709                                        &out_output_buffer);
 710                 if (!NT_STATUS_IS_OK(status)) {
 711                         goto out;
 712                 }
 713
 714                 if (out_output_buffer.length < 4) {
 715                         status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 716                         goto out;
 717                 }
 718
 719                 recv_flags2 = FLAGS2_UNICODE_STRINGS;
 720                 rdata = out_output_buffer.data;
 721                 endp = (char *)rdata + out_output_buffer.length;
 722         } else {
 723                 unsigned int data_len = 0;
 724                 uint16_t setup[1];
 725
 726                 SSVAL(setup, 0, TRANSACT2_GET_DFS_REFERRAL);
 727
 728                 status = cli_trans(talloc_tos(), cli, SMBtrans2,
 729                                    NULL, 0xffff, 0, 0,
 730                                    setup, 1, 0,
 731                                    param, param_len, 2,
 732                                    NULL, 0, CLI_BUFFER_SIZE,
 733                                    &recv_flags2,
 734                                    NULL, 0, NULL, /* rsetup */
 735                                    NULL, 0, NULL,
 736                                    &rdata, 4, &data_len);
 737                 if (!NT_STATUS_IS_OK(status)) {
 738                         goto out;
 739                 }
 740
 741                 endp = (char *)rdata + data_len;
 742         }
 743
 744         consumed_ucs  = SVAL(rdata, 0);
 745         num_referrals = SVAL(rdata, 2);
 746
 747         /* consumed_ucs is the number of bytes
 748          * of the UCS2 path consumed not counting any
 749          * terminating null. We need to convert
 750          * back to unix charset and count again
 751          * to get the number of bytes consumed from
 752          * the incoming path. */
 753
 754         errno = 0;
 755         if (pull_string_talloc(talloc_tos(),
 756                         NULL,
 757                         0,
 758                         &consumed_path,
 759                         path_ucs,
 760                         consumed_ucs,
 761                         STR_UNICODE) == 0) {
 762                 if (errno != 0) {
 763                         status = map_nt_error_from_unix(errno);
 764                 } else {
 765                         status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 766                 }
 767                 goto out;
 768         }
 769         if (consumed_path == NULL) {
 770                 status = map_nt_error_from_unix(errno);
 771                 goto out;
 772         }
 773         *consumed = strlen(consumed_path);
 774
 775         if (num_referrals != 0) {
 776                 uint16_t ref_version;
 777                 uint16_t ref_size;
 778                 int i;
 779                 uint16_t node_offset;
 780
 781                 referrals = talloc_array(ctx, struct client_dfs_referral,
 782                                          num_referrals);
 783
 784                 if (!referrals) {
 785                         status = NT_STATUS_NO_MEMORY;
 786                         goto out;
 787                 }
 788                 /* start at the referrals array */
 789
 790                 p = (char *)rdata+8;
 791                 for (i=0; i<num_referrals && p < endp; i++) {
 792                         if (p + 18 > endp) {
 793                                 goto out;
 794                         }
 795                         ref_version = SVAL(p, 0);
 796                         ref_size    = SVAL(p, 2);
 797                         node_offset = SVAL(p, 16);
 798
 799                         if (ref_version != 3) {
 800                                 p += ref_size;
 801                                 continue;
 802                         }
 803
 804                         referrals[i].proximity = SVAL(p, 8);
 805                         referrals[i].ttl       = SVAL(p, 10);
 806
 807                         if (p + node_offset > endp) {
 808                                 status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 809                                 goto out;
 810                         }
 811                         pull_string_talloc(referrals,
 812                                            (const char *)rdata,
 813                                            recv_flags2,
 814                                            &referrals[i].dfspath,
 815                                            p+node_offset,
 816                                            PTR_DIFF(endp, p+node_offset),
 817                                            STR_TERMINATE|STR_UNICODE);
 818
 819                         if (!referrals[i].dfspath) {
 820                                 status = map_nt_error_from_unix(errno);
 821                                 goto out;
 822                         }
 823                         p += ref_size;
 824                 }
 825                 if (i < num_referrals) {
 826                         status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 827                         goto out;
 828                 }
 829         }
 830
 831         *num_refs = num_referrals;
 832         *refs = referrals;
 833
 834   out:
 835
 836         TALLOC_FREE(frame);
 837         return status;
 838 }
 839
 840 NTSTATUS cli_dfs_get_referral(TALLOC_CTX *ctx,
 841                         struct cli_state *cli,
 842                         const char *path,
 843                         struct client_dfs_referral **refs,
 844                         size_t *num_refs,
 845                         size_t *consumed)
 846 {
 847         return cli_dfs_get_referral_ex(ctx,
 848                                 cli,
 849                                 path,
 850                                 3,
 851                                 refs, /* Max referral level we want */
 852                                 num_refs,
 853                                 consumed);
 854 }
 855
 856 static bool cli_conn_have_dfs(struct cli_state *cli)
 857 {
 858         struct smbXcli_conn *conn = cli->conn;
 859         struct smbXcli_tcon *tcon = NULL;
 860         bool ok;
 861
 862         if (smbXcli_conn_protocol(conn) < PROTOCOL_SMB2_02) {
 863                 uint32_t capabilities = smb1cli_conn_capabilities(conn);
 864
 865                 if ((capabilities & CAP_STATUS32) == 0) {
 866                         return false;
 867                 }
 868                 if ((capabilities & CAP_UNICODE) == 0) {
 869                         return false;
 870                 }
 871
 872                 tcon = cli->smb1.tcon;
 873         } else {
 874                 tcon = cli->smb2.tcon;
 875         }
 876
 877         ok = smbXcli_tcon_is_dfs_share(tcon);
 878         return ok;
 879 }
 880
 881 /********************************************************************
 882 ********************************************************************/
 883 struct cli_dfs_path_split {
 884         char *server;
 885         char *share;
 886         char *extrapath;
 887 };
 888
 889 NTSTATUS cli_resolve_path(TALLOC_CTX *ctx,
 890                           const char *mountpt,
 891                           struct cli_credentials *creds,
 892                           struct cli_state *rootcli,
 893                           const char *path,
 894                           struct cli_state **targetcli,
 895                           char **pp_targetpath)
 896 {
 897         struct client_dfs_referral *refs = NULL;
 898         size_t num_refs = 0;
 899         size_t consumed = 0;
 900         struct cli_state *cli_ipc = NULL;
 901         char *dfs_path = NULL;
 902         char *cleanpath = NULL;
 903         char *extrapath = NULL;
 904         int pathlen;
 905         struct cli_state *newcli = NULL;
 906         struct cli_state *ccli = NULL;
 907         size_t count = 0;
 908         char *newpath = NULL;
 909         char *newmount = NULL;
 910         char *ppath = NULL;
 911         SMB_STRUCT_STAT sbuf;
 912         uint32_t attributes;
 913         NTSTATUS status;
 914         struct smbXcli_tcon *target_tcon = NULL;
 915         struct cli_dfs_path_split *dfs_refs = NULL;
 916         bool ok;
 917         bool is_already_dfs = false;
 918
 919         if ( !rootcli || !path || !targetcli ) {
 920                 return NT_STATUS_INVALID_PARAMETER;
 921         }
 922
 923         /*
 924          * Avoid more than one leading directory separator
 925          */
 926         while (IS_DIRECTORY_SEP(path[0]) && IS_DIRECTORY_SEP(path[1])) {
 927                 path++;
 928         }
 929
 930         ok = cli_conn_have_dfs(rootcli);
 931         if (!ok) {
 932                 *targetcli = rootcli;
 933                 *pp_targetpath = talloc_strdup(ctx, path);
 934                 if (!*pp_targetpath) {
 935                         return NT_STATUS_NO_MEMORY;
 936                 }
 937                 return NT_STATUS_OK;
 938         }
 939
 940         *targetcli = NULL;
 941
 942         is_already_dfs = cli_dfs_is_already_full_path(rootcli, path);
 943         if (is_already_dfs) {
 944                 const char *localpath = NULL;
 945                 /*
 946                  * Given path is already converted to DFS.
 947                  * Convert to a local path so clean_path()
 948                  * can correctly strip any wildcards.
 949                  */
 950                 status = cli_dfs_target_check(ctx,
 951                                               rootcli,
 952                                               path,
 953                                               &localpath);
 954                 if (!NT_STATUS_IS_OK(status)) {
 955                         return status;
 956                 }
 957                 path = localpath;
 958         }
 959
 960         /* Send a trans2_query_path_info to check for a referral. */
 961
 962         cleanpath = clean_path(ctx, path);
 963         if (!cleanpath) {
 964                 return NT_STATUS_NO_MEMORY;
 965         }
 966
 967         dfs_path = cli_dfs_make_full_path(ctx, rootcli, cleanpath);
 968         if (!dfs_path) {
 969                 return NT_STATUS_NO_MEMORY;
 970         }
 971
 972         status = cli_qpathinfo_basic( rootcli, dfs_path, &sbuf, &attributes);
 973         if (NT_STATUS_IS_OK(status)) {
 974                 /* This is an ordinary path, just return it. */
 975                 *targetcli = rootcli;
 976                 *pp_targetpath = talloc_strdup(ctx, path);
 977                 if (!*pp_targetpath) {
 978                         return NT_STATUS_NO_MEMORY;
 979                 }
 980                 goto done;
 981         }
 982
 983         /* Special case where client asked for a path that does not exist */
 984
 985         if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
 986                 *targetcli = rootcli;
 987                 *pp_targetpath = talloc_strdup(ctx, path);
 988                 if (!*pp_targetpath) {
 989                         return NT_STATUS_NO_MEMORY;
 990                 }
 991                 goto done;
 992         }
 993
 994         /* We got an error, check for DFS referral. */
 995
 996         if (!NT_STATUS_EQUAL(status, NT_STATUS_PATH_NOT_COVERED)) {
 997                 return status;
 998         }
 999
1000         /* Check for the referral. */
1001
1002         status = cli_cm_open(ctx,
1003                              rootcli,
1004                              smbXcli_conn_remote_name(rootcli->conn),
1005                              "IPC$",
1006                              creds,
1007                              NULL, /* dest_ss not needed, we reuse the transport */
1008                              0,
1009                              0x20,
1010                              &cli_ipc);
1011         if (!NT_STATUS_IS_OK(status)) {
1012                 return status;
1013         }
1014
1015         status = cli_dfs_get_referral(ctx, cli_ipc, dfs_path, &refs,
1016                                       &num_refs, &consumed);
1017         if (!NT_STATUS_IS_OK(status)) {
1018                 return status;
1019         }
1020
1021         if (!num_refs || !refs[0].dfspath) {
1022                 return NT_STATUS_NOT_FOUND;
1023         }
1024
1025         /*
1026          * Bug#10123 - DFS referral entries can be provided in a random order,
1027          * so check the connection cache for each item to avoid unnecessary
1028          * reconnections.
1029          */
1030         dfs_refs = talloc_array(ctx, struct cli_dfs_path_split, num_refs);
1031         if (dfs_refs == NULL) {
1032                 return NT_STATUS_NO_MEMORY;
1033         }
1034
1035         for (count = 0; count < num_refs; count++) {
1036                 if (!split_dfs_path(dfs_refs, refs[count].dfspath,
1037                                     &dfs_refs[count].server,
1038                                     &dfs_refs[count].share,
1039                                     &dfs_refs[count].extrapath)) {
1040                         TALLOC_FREE(dfs_refs);
1041                         return NT_STATUS_NOT_FOUND;
1042                 }
1043
1044                 ccli = cli_cm_find(rootcli, dfs_refs[count].server,
1045                                    dfs_refs[count].share);
1046                 if (ccli != NULL) {
1047                         extrapath = dfs_refs[count].extrapath;
1048                         *targetcli = ccli;
1049                         break;
1050                 }
1051         }
1052
1053         /*
1054          * If no cached connection was found, then connect to the first live
1055          * referral server in the list.
1056          */
1057         for (count = 0; (ccli == NULL) && (count < num_refs); count++) {
1058                 /* Connect to the target server & share */
1059                 status = cli_cm_connect(ctx, rootcli,
1060                                 dfs_refs[count].server,
1061                                 dfs_refs[count].share,
1062                                 creds,
1063                                 NULL, /* dest_ss */
1064                                 0, /* port */
1065                                 0x20,
1066                                 targetcli);
1067                 if (!NT_STATUS_IS_OK(status)) {
1068                         d_printf("Unable to follow dfs referral [\\%s\\%s]\n",
1069                                  dfs_refs[count].server,
1070                                  dfs_refs[count].share);
1071                         continue;
1072                 } else {
1073                         extrapath = dfs_refs[count].extrapath;
1074                         break;
1075                 }
1076         }
1077
1078         /* No available referral server for the connection */
1079         if (*targetcli == NULL) {
1080                 TALLOC_FREE(dfs_refs);
1081                 return status;
1082         }
1083
1084         /* Make sure to recreate the original string including any wildcards. */
1085
1086         dfs_path = cli_dfs_make_full_path(ctx, rootcli, path);
1087         if (!dfs_path) {
1088                 TALLOC_FREE(dfs_refs);
1089                 return NT_STATUS_NO_MEMORY;
1090         }
1091         pathlen = strlen(dfs_path);
1092         consumed = MIN(pathlen, consumed);
1093         *pp_targetpath = talloc_strdup(ctx, &dfs_path[consumed]);
1094         if (!*pp_targetpath) {
1095                 TALLOC_FREE(dfs_refs);
1096                 return NT_STATUS_NO_MEMORY;
1097         }
1098         dfs_path[consumed] = '\0';
1099
1100         /*
1101          * *pp_targetpath is now the unconsumed part of the path.
1102          * dfs_path is now the consumed part of the path
1103          * (in \server\share\path format).
1104          */
1105
1106         if (extrapath && strlen(extrapath) > 0) {
1107                 /* EMC Celerra NAS version 5.6.50 (at least) doesn't appear to */
1108                 /* put the trailing \ on the path, so to be safe we put one in if needed */
1109                 if (extrapath[strlen(extrapath)-1] != '\\' && **pp_targetpath != '\\') {
1110                         *pp_targetpath = talloc_asprintf(ctx,
1111                                                   "%s\\%s",
1112                                                   extrapath,
1113                                                   *pp_targetpath);
1114                 } else {
1115                         *pp_targetpath = talloc_asprintf(ctx,
1116                                                   "%s%s",
1117                                                   extrapath,
1118                                                   *pp_targetpath);
1119                 }
1120                 if (!*pp_targetpath) {
1121                         TALLOC_FREE(dfs_refs);
1122                         return NT_STATUS_NO_MEMORY;
1123                 }
1124         }
1125
1126         /* parse out the consumed mount path */
1127         /* trim off the \server\share\ */
1128
1129         ppath = dfs_path;
1130
1131         if (*ppath != '\\') {
1132                 d_printf("cli_resolve_path: "
1133                         "dfs_path (%s) not in correct format.\n",
1134                         dfs_path );
1135                 TALLOC_FREE(dfs_refs);
1136                 return NT_STATUS_NOT_FOUND;
1137         }
1138
1139         ppath++; /* Now pointing at start of server name. */
1140
1141         if ((ppath = strchr_m( dfs_path, '\\' )) == NULL) {
1142                 TALLOC_FREE(dfs_refs);
1143                 return NT_STATUS_NOT_FOUND;
1144         }
1145
1146         ppath++; /* Now pointing at start of share name. */
1147
1148         if ((ppath = strchr_m( ppath+1, '\\' )) == NULL) {
1149                 TALLOC_FREE(dfs_refs);
1150                 return NT_STATUS_NOT_FOUND;
1151         }
1152
1153         ppath++; /* Now pointing at path component. */
1154
1155         newmount = talloc_asprintf(ctx, "%s\\%s", mountpt, ppath );
1156         if (!newmount) {
1157                 TALLOC_FREE(dfs_refs);
1158                 return NT_STATUS_NOT_FOUND;
1159         }
1160
1161         /* Check for another dfs referral, note that we are not
1162            checking for loops here. */
1163
1164         if (!strequal(*pp_targetpath, "\\") && !strequal(*pp_targetpath, "/")) {
1165                 status = cli_resolve_path(ctx,
1166                                           newmount,
1167                                           creds,
1168                                           *targetcli,
1169                                           *pp_targetpath,
1170                                           &newcli,
1171                                           &newpath);
1172                 if (NT_STATUS_IS_OK(status)) {
1173                         /*
1174                          * When cli_resolve_path returns true here it's always
1175                          * returning the complete path in newpath, so we're done
1176                          * here.
1177                          */
1178                         *targetcli = newcli;
1179                         *pp_targetpath = newpath;
1180                         TALLOC_FREE(dfs_refs);
1181                         return status;
1182                 }
1183         }
1184
1185   done:
1186
1187         if (smbXcli_conn_protocol((*targetcli)->conn) >= PROTOCOL_SMB2_02) {
1188                 target_tcon = (*targetcli)->smb2.tcon;
1189         } else {
1190                 target_tcon = (*targetcli)->smb1.tcon;
1191         }
1192
1193         /* If returning true ensure we return a dfs root full path. */
1194         if (smbXcli_tcon_is_dfs_share(target_tcon)) {
1195                 dfs_path = talloc_strdup(ctx, *pp_targetpath);
1196                 if (!dfs_path) {
1197                         TALLOC_FREE(dfs_refs);
1198                         return NT_STATUS_NO_MEMORY;
1199                 }
1200                 *pp_targetpath = cli_dfs_make_full_path(ctx, *targetcli, dfs_path);
1201                 if (*pp_targetpath == NULL) {
1202                         TALLOC_FREE(dfs_refs);
1203                         return NT_STATUS_NO_MEMORY;
1204                 }
1205         }
1206
1207         TALLOC_FREE(dfs_refs);
1208         return NT_STATUS_OK;
1209 }
1210
1211 /********************************************************************
1212 ********************************************************************/
1213
1214 bool cli_check_msdfs_proxy(TALLOC_CTX *ctx,
1215                                 struct cli_state *cli,
1216                                 const char *sharename,
1217                                 char **pp_newserver,
1218                                 char **pp_newshare,
1219                                 struct cli_credentials *creds)
1220 {
1221         struct client_dfs_referral *refs = NULL;
1222         size_t num_refs = 0;
1223         size_t consumed = 0;
1224         char *fullpath = NULL;
1225         bool res;
1226         struct smbXcli_tcon *orig_tcon = NULL;
1227         char *orig_share = NULL;
1228         char *newextrapath = NULL;
1229         NTSTATUS status;
1230         const char *remote_name;
1231         enum smb_encryption_setting encryption_state =
1232                 cli_credentials_get_smb_encryption(creds);
1233
1234         if (!cli || !sharename) {
1235                 return false;
1236         }
1237
1238         remote_name = smbXcli_conn_remote_name(cli->conn);
1239
1240         /* special case.  never check for a referral on the IPC$ share */
1241
1242         if (strequal(sharename, "IPC$")) {
1243                 return false;
1244         }
1245
1246         /* send a trans2_query_path_info to check for a referral */
1247
1248         fullpath = talloc_asprintf(ctx, "\\%s\\%s", remote_name, sharename);
1249         if (!fullpath) {
1250                 return false;
1251         }
1252
1253         /* Store tcon state. */
1254         if (cli_state_has_tcon(cli)) {
1255                 cli_state_save_tcon_share(cli, &orig_tcon, &orig_share);
1256         }
1257
1258         /* check for the referral */
1259
1260         if (!NT_STATUS_IS_OK(cli_tree_connect(cli, "IPC$", "IPC", NULL))) {
1261                 cli_state_restore_tcon_share(cli, orig_tcon, orig_share);
1262                 return false;
1263         }
1264
1265         if (encryption_state >= SMB_ENCRYPTION_DESIRED) {
1266                 status = cli_cm_force_encryption_creds(cli, creds, "IPC$");
1267                 if (!NT_STATUS_IS_OK(status)) {
1268                         switch (encryption_state) {
1269                         case SMB_ENCRYPTION_DESIRED:
1270                                 break;
1271                         case SMB_ENCRYPTION_REQUIRED:
1272                         default:
1273                                 /*
1274                                  * Failed to set up encryption.
1275                                  * Disconnect the temporary IPC$
1276                                  * tcon before restoring the original
1277                                  * tcon so we don't leak it.
1278                                  */
1279                                 cli_tdis(cli);
1280                                 cli_state_restore_tcon_share(cli,
1281                                                              orig_tcon,
1282                                                              orig_share);
1283                                 return false;
1284                         }
1285                 }
1286         }
1287
1288         status = cli_dfs_get_referral(ctx, cli, fullpath, &refs,
1289                                       &num_refs, &consumed);
1290         res = NT_STATUS_IS_OK(status);
1291
1292         status = cli_tdis(cli);
1293
1294         cli_state_restore_tcon_share(cli, orig_tcon, orig_share);
1295
1296         if (!NT_STATUS_IS_OK(status)) {
1297                 return false;
1298         }
1299
1300         if (!res || !num_refs) {
1301                 return false;
1302         }
1303
1304         if (!refs[0].dfspath) {
1305                 return false;
1306         }
1307
1308         if (!split_dfs_path(ctx, refs[0].dfspath, pp_newserver,
1309                             pp_newshare, &newextrapath)) {
1310                 return false;
1311         }
1312
1313         /* check that this is not a self-referral */
1314
1315         if (strequal(remote_name, *pp_newserver) &&
1316                         strequal(sharename, *pp_newshare)) {
1317                 return false;
1318         }
1319
1320         return true;
1321 }
1322
1323 /********************************************************************
1324  Windows and NetApp (and arguably the SMB1/2/3 specs) expect a non-DFS
1325  path for the targets of rename and hardlink. If we have been given
1326  a DFS path for these calls, convert it back into a local path by
1327  stripping off the DFS prefix.
1328 ********************************************************************/
1329
1330 NTSTATUS cli_dfs_target_check(TALLOC_CTX *mem_ctx,
1331                         struct cli_state *cli,
1332                         const char *fname_dst,
1333                         const char **fname_dst_out)
1334 {
1335         char *dfs_prefix = NULL;
1336         size_t prefix_len = 0;
1337         struct smbXcli_tcon *tcon = NULL;
1338
1339         if (!smbXcli_conn_dfs_supported(cli->conn)) {
1340                 goto copy_fname_out;
1341         }
1342         if (smbXcli_conn_protocol(cli->conn) >= PROTOCOL_SMB2_02) {
1343                 tcon = cli->smb2.tcon;
1344         } else {
1345                 tcon = cli->smb1.tcon;
1346         }
1347         if (!smbXcli_tcon_is_dfs_share(tcon)) {
1348                 goto copy_fname_out;
1349         }
1350         dfs_prefix = cli_dfs_make_full_path(mem_ctx, cli, "");
1351         if (dfs_prefix == NULL) {
1352                 return NT_STATUS_NO_MEMORY;
1353         }
1354         prefix_len = strlen(dfs_prefix);
1355         if (strncmp(fname_dst, dfs_prefix, prefix_len) != 0) {
1356                 /*
1357                  * Prefix doesn't match. Assume it was
1358                  * already stripped or not added in the
1359                  * first place.
1360                  */
1361                 goto copy_fname_out;
1362         }
1363         /* Return the trailing name after the prefix. */
1364         *fname_dst_out = &fname_dst[prefix_len];
1365         TALLOC_FREE(dfs_prefix);
1366         return NT_STATUS_OK;
1367
1368   copy_fname_out:
1369
1370         /*
1371          * No change to the destination name. Just
1372          * point it at the incoming destination name.
1373          */
1374         *fname_dst_out = fname_dst;
1375         TALLOC_FREE(dfs_prefix);
1376         return NT_STATUS_OK;
1377 }
1378
1379 /********************************************************************
1380  Convert a pathname into a DFS path if it hasn't already been converted.
1381  Always returns a talloc'ed path, makes it easy to pass const paths in.
1382 ********************************************************************/
1383
1384 char *smb1_dfs_share_path(TALLOC_CTX *ctx,
1385                           struct cli_state *cli,
1386                           const char *path)
1387 {
1388         bool is_dfs = smbXcli_conn_dfs_supported(cli->conn) &&
1389                         smbXcli_tcon_is_dfs_share(cli->smb1.tcon);
1390         bool is_already_dfs_path = false;
1391         bool posix = (cli->requested_posix_capabilities &
1392                         CIFS_UNIX_POSIX_PATHNAMES_CAP);
1393         char sepchar = (posix ? '/' : '\\');
1394
1395         if (!is_dfs) {
1396                 return talloc_strdup(ctx, path);
1397         }
1398         is_already_dfs_path = cli_dfs_is_already_full_path(cli, path);
1399         if (is_already_dfs_path) {
1400                 return talloc_strdup(ctx, path);
1401         }
1402         /*
1403          * We don't use cli_dfs_make_full_path() as,
1404          * when given a null path, cli_dfs_make_full_path
1405          * deliberately adds a trailing '\\' (this is by
1406          * design to check for an existing DFS prefix match).
1407          */
1408         if (path[0] == '\0') {
1409                 return talloc_asprintf(ctx,
1410                                        "%c%s%c%s",
1411                                        sepchar,
1412                                        smbXcli_conn_remote_name(cli->conn),
1413                                        sepchar,
1414                                        cli->share);
1415         }
1416         while (*path == sepchar) {
1417                 path++;
1418         }
1419         return talloc_asprintf(ctx,
1420                                "%c%s%c%s%c%s",
1421                                sepchar,
1422                                smbXcli_conn_remote_name(cli->conn),
1423                                sepchar,
1424                                cli->share,
1425                                sepchar,
1426                                path);
1427 }