source3/smbd/vfs.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    VFS initialisation and support functions
   5    Copyright (C) Tim Potter 1999
   6    Copyright (C) Alexander Bokovoy 2002
   7    Copyright (C) James Peach 2006
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22    This work was sponsored by Optifacio Software Services, Inc.
  23 */
  24
  25 #include "includes.h"
  26 #include "smbd/globals.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_VFS
  30
  31 static_decl_vfs;
  32
  33 struct vfs_init_function_entry {
  34         char *name;
  35         const vfs_op_tuple *vfs_op_tuples;
  36         struct vfs_init_function_entry *prev, *next;
  37 };
  38
  39 /****************************************************************************
  40     maintain the list of available backends
  41 ****************************************************************************/
  42
  43 static struct vfs_init_function_entry *vfs_find_backend_entry(const char *name)
  44 {
  45         struct vfs_init_function_entry *entry = backends;
  46
  47         DEBUG(10, ("vfs_find_backend_entry called for %s\n", name));
  48
  49         while(entry) {
  50                 if (strcmp(entry->name, name)==0) return entry;
  51                 entry = entry->next;
  52         }
  53
  54         return NULL;
  55 }
  56
  57 NTSTATUS smb_register_vfs(int version, const char *name, const vfs_op_tuple *vfs_op_tuples)
  58 {
  59         struct vfs_init_function_entry *entry = backends;
  60
  61         if ((version != SMB_VFS_INTERFACE_VERSION)) {
  62                 DEBUG(0, ("Failed to register vfs module.\n"
  63                           "The module was compiled against SMB_VFS_INTERFACE_VERSION %d,\n"
  64                           "current SMB_VFS_INTERFACE_VERSION is %d.\n"
  65                           "Please recompile against the current Samba Version!\n",
  66                           version, SMB_VFS_INTERFACE_VERSION));
  67                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  68         }
  69
  70         if (!name || !name[0] || !vfs_op_tuples) {
  71                 DEBUG(0,("smb_register_vfs() called with NULL pointer or empty name!\n"));
  72                 return NT_STATUS_INVALID_PARAMETER;
  73         }
  74
  75         if (vfs_find_backend_entry(name)) {
  76                 DEBUG(0,("VFS module %s already loaded!\n", name));
  77                 return NT_STATUS_OBJECT_NAME_COLLISION;
  78         }
  79
  80         entry = SMB_XMALLOC_P(struct vfs_init_function_entry);
  81         entry->name = smb_xstrdup(name);
  82         entry->vfs_op_tuples = vfs_op_tuples;
  83
  84         DLIST_ADD(backends, entry);
  85         DEBUG(5, ("Successfully added vfs backend '%s'\n", name));
  86         return NT_STATUS_OK;
  87 }
  88
  89 /****************************************************************************
  90   initialise default vfs hooks
  91 ****************************************************************************/
  92
  93 static void vfs_init_default(connection_struct *conn)
  94 {
  95         DEBUG(3, ("Initialising default vfs hooks\n"));
  96         vfs_init_custom(conn, DEFAULT_VFS_MODULE_NAME);
  97 }
  98
  99 /****************************************************************************
 100   initialise custom vfs hooks
 101  ****************************************************************************/
 102
 103 static inline void vfs_set_operation(struct vfs_ops * vfs, vfs_op_type which,
 104                                 struct vfs_handle_struct * handle, void * op)
 105 {
 106         ((struct vfs_handle_struct **)&vfs->handles)[which] = handle;
 107         ((void **)(void *)&vfs->ops)[which] = op;
 108 }
 109
 110 bool vfs_init_custom(connection_struct *conn, const char *vfs_object)
 111 {
 112         const vfs_op_tuple *ops;
 113         char *module_path = NULL;
 114         char *module_name = NULL;
 115         char *module_param = NULL, *p;
 116         int i;
 117         vfs_handle_struct *handle;
 118         const struct vfs_init_function_entry *entry;
 119
 120         if (!conn||!vfs_object||!vfs_object[0]) {
 121                 DEBUG(0,("vfs_init_custon() called with NULL pointer or emtpy vfs_object!\n"));
 122                 return False;
 123         }
 124
 125         if(!backends) {
 126                 static_init_vfs;
 127         }
 128
 129         DEBUG(3, ("Initialising custom vfs hooks from [%s]\n", vfs_object));
 130
 131         module_path = smb_xstrdup(vfs_object);
 132
 133         p = strchr_m(module_path, ':');
 134
 135         if (p) {
 136                 *p = 0;
 137                 module_param = p+1;
 138                 trim_char(module_param, ' ', ' ');
 139         }
 140
 141         trim_char(module_path, ' ', ' ');
 142
 143         module_name = smb_xstrdup(module_path);
 144
 145         if ((module_name[0] == '/') &&
 146             (strcmp(module_path, DEFAULT_VFS_MODULE_NAME) != 0)) {
 147
 148                 /*
 149                  * Extract the module name from the path. Just use the base
 150                  * name of the last path component.
 151                  */
 152
 153                 SAFE_FREE(module_name);
 154                 module_name = smb_xstrdup(strrchr_m(module_path, '/')+1);
 155
 156                 p = strchr_m(module_name, '.');
 157
 158                 if (p != NULL) {
 159                         *p = '\0';
 160                 }
 161         }
 162
 163         /* First, try to load the module with the new module system */
 164         if((entry = vfs_find_backend_entry(module_name)) ||
 165            (NT_STATUS_IS_OK(smb_probe_module("vfs", module_path)) &&
 166                 (entry = vfs_find_backend_entry(module_name)))) {
 167
 168                 DEBUGADD(5,("Successfully loaded vfs module [%s] with the new modules system\n", vfs_object));
 169
 170                 if ((ops = entry->vfs_op_tuples) == NULL) {
 171                         DEBUG(0, ("entry->vfs_op_tuples==NULL for [%s] failed\n", vfs_object));
 172                         goto fail;
 173                 }
 174         } else {
 175                 DEBUG(0,("Can't find a vfs module [%s]\n",vfs_object));
 176                 goto fail;
 177         }
 178
 179         handle = TALLOC_ZERO_P(conn, vfs_handle_struct);
 180         if (!handle) {
 181                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 182                 goto fail;
 183         }
 184         memcpy(&handle->vfs_next, &conn->vfs, sizeof(struct vfs_ops));
 185         handle->conn = conn;
 186         if (module_param) {
 187                 handle->param = talloc_strdup(conn, module_param);
 188         }
 189         DLIST_ADD(conn->vfs_handles, handle);
 190
 191         for(i=0; ops[i].op != NULL; i++) {
 192                 DEBUG(5, ("Checking operation #%d (type %d, layer %d)\n", i, ops[i].type, ops[i].layer));
 193                 if(ops[i].layer == SMB_VFS_LAYER_OPAQUE) {
 194                         /* If this operation was already made opaque by different module, it
 195                          * will be overridden here.
 196                          */
 197                         DEBUGADD(5, ("Making operation type %d opaque [module %s]\n", ops[i].type, vfs_object));
 198                         vfs_set_operation(&conn->vfs_opaque, ops[i].type, handle, ops[i].op);
 199                 }
 200                 /* Change current VFS disposition*/
 201                 DEBUGADD(5, ("Accepting operation type %d from module %s\n", ops[i].type, vfs_object));
 202                 vfs_set_operation(&conn->vfs, ops[i].type, handle, ops[i].op);
 203         }
 204
 205         SAFE_FREE(module_path);
 206         SAFE_FREE(module_name);
 207         return True;
 208
 209  fail:
 210         SAFE_FREE(module_path);
 211         SAFE_FREE(module_name);
 212         return False;
 213 }
 214
 215 /*****************************************************************
 216  Allow VFS modules to extend files_struct with VFS-specific state.
 217  This will be ok for small numbers of extensions, but might need to
 218  be refactored if it becomes more widely used.
 219 ******************************************************************/
 220
 221 #define EXT_DATA_AREA(e) ((uint8 *)(e) + sizeof(struct vfs_fsp_data))
 222
 223 void *vfs_add_fsp_extension_notype(vfs_handle_struct *handle, files_struct *fsp, size_t ext_size)
 224 {
 225         struct vfs_fsp_data *ext;
 226         void * ext_data;
 227
 228         /* Prevent VFS modules adding multiple extensions. */
 229         if ((ext_data = vfs_fetch_fsp_extension(handle, fsp))) {
 230                 return ext_data;
 231         }
 232
 233         ext = (struct vfs_fsp_data *)TALLOC_ZERO(
 234                 handle->conn, sizeof(struct vfs_fsp_data) + ext_size);
 235         if (ext == NULL) {
 236                 return NULL;
 237         }
 238
 239         ext->owner = handle;
 240         ext->next = fsp->vfs_extension;
 241         fsp->vfs_extension = ext;
 242         return EXT_DATA_AREA(ext);
 243 }
 244
 245 void vfs_remove_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 246 {
 247         struct vfs_fsp_data *curr;
 248         struct vfs_fsp_data *prev;
 249
 250         for (curr = fsp->vfs_extension, prev = NULL;
 251              curr;
 252              prev = curr, curr = curr->next) {
 253                 if (curr->owner == handle) {
 254                     if (prev) {
 255                             prev->next = curr->next;
 256                     } else {
 257                             fsp->vfs_extension = curr->next;
 258                     }
 259                     TALLOC_FREE(curr);
 260                     return;
 261                 }
 262         }
 263 }
 264
 265 void *vfs_memctx_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 266 {
 267         struct vfs_fsp_data *head;
 268
 269         for (head = fsp->vfs_extension; head; head = head->next) {
 270                 if (head->owner == handle) {
 271                         return head;
 272                 }
 273         }
 274
 275         return NULL;
 276 }
 277
 278 void *vfs_fetch_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 279 {
 280         struct vfs_fsp_data *head;
 281
 282         head = (struct vfs_fsp_data *)vfs_memctx_fsp_extension(handle, fsp);
 283         if (head != NULL) {
 284                 return EXT_DATA_AREA(head);
 285         }
 286
 287         return NULL;
 288 }
 289
 290 #undef EXT_DATA_AREA
 291
 292 /*****************************************************************
 293  Generic VFS init.
 294 ******************************************************************/
 295
 296 bool smbd_vfs_init(connection_struct *conn)
 297 {
 298         const char **vfs_objects;
 299         unsigned int i = 0;
 300         int j = 0;
 301
 302         /* Normal share - initialise with disk access functions */
 303         vfs_init_default(conn);
 304         vfs_objects = lp_vfs_objects(SNUM(conn));
 305
 306         /* Override VFS functions if 'vfs object' was not specified*/
 307         if (!vfs_objects || !vfs_objects[0])
 308                 return True;
 309
 310         for (i=0; vfs_objects[i] ;) {
 311                 i++;
 312         }
 313
 314         for (j=i-1; j >= 0; j--) {
 315                 if (!vfs_init_custom(conn, vfs_objects[j])) {
 316                         DEBUG(0, ("smbd_vfs_init: vfs_init_custom failed for %s\n", vfs_objects[j]));
 317                         return False;
 318                 }
 319         }
 320         return True;
 321 }
 322
 323 /*******************************************************************
 324  Check if directory exists.
 325 ********************************************************************/
 326
 327 bool vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
 328 {
 329         SMB_STRUCT_STAT st2;
 330         bool ret;
 331
 332         if (!st)
 333                 st = &st2;
 334
 335         if (SMB_VFS_STAT(conn,dname,st) != 0)
 336                 return(False);
 337
 338         ret = S_ISDIR(st->st_mode);
 339         if(!ret)
 340                 errno = ENOTDIR;
 341
 342         return ret;
 343 }
 344
 345 /*******************************************************************
 346  Check if an object exists in the vfs.
 347 ********************************************************************/
 348
 349 bool vfs_object_exist(connection_struct *conn,const char *fname,SMB_STRUCT_STAT *sbuf)
 350 {
 351         SMB_STRUCT_STAT st;
 352
 353         if (!sbuf)
 354                 sbuf = &st;
 355
 356         ZERO_STRUCTP(sbuf);
 357
 358         if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
 359                 return(False);
 360         return True;
 361 }
 362
 363 /*******************************************************************
 364  Check if a file exists in the vfs.
 365 ********************************************************************/
 366
 367 bool vfs_file_exist(connection_struct *conn, const char *fname,SMB_STRUCT_STAT *sbuf)
 368 {
 369         SMB_STRUCT_STAT st;
 370
 371         if (!sbuf)
 372                 sbuf = &st;
 373
 374         ZERO_STRUCTP(sbuf);
 375
 376         if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
 377                 return False;
 378         return(S_ISREG(sbuf->st_mode));
 379 }
 380
 381 /****************************************************************************
 382  Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
 383 ****************************************************************************/
 384
 385 ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
 386 {
 387         size_t total=0;
 388
 389         while (total < byte_count)
 390         {
 391                 ssize_t ret = SMB_VFS_READ(fsp, buf + total,
 392                                            byte_count - total);
 393
 394                 if (ret == 0) return total;
 395                 if (ret == -1) {
 396                         if (errno == EINTR)
 397                                 continue;
 398                         else
 399                                 return -1;
 400                 }
 401                 total += ret;
 402         }
 403         return (ssize_t)total;
 404 }
 405
 406 ssize_t vfs_pread_data(files_struct *fsp, char *buf,
 407                 size_t byte_count, SMB_OFF_T offset)
 408 {
 409         size_t total=0;
 410
 411         while (total < byte_count)
 412         {
 413                 ssize_t ret = SMB_VFS_PREAD(fsp, buf + total,
 414                                         byte_count - total, offset + total);
 415
 416                 if (ret == 0) return total;
 417                 if (ret == -1) {
 418                         if (errno == EINTR)
 419                                 continue;
 420                         else
 421                                 return -1;
 422                 }
 423                 total += ret;
 424         }
 425         return (ssize_t)total;
 426 }
 427
 428 /****************************************************************************
 429  Write data to a fd on the vfs.
 430 ****************************************************************************/
 431
 432 ssize_t vfs_write_data(struct smb_request *req,
 433                         files_struct *fsp,
 434                         const char *buffer,
 435                         size_t N)
 436 {
 437         size_t total=0;
 438         ssize_t ret;
 439
 440         if (req && req->unread_bytes) {
 441                 SMB_ASSERT(req->unread_bytes == N);
 442                 /* VFS_RECVFILE must drain the socket
 443                  * before returning. */
 444                 req->unread_bytes = 0;
 445                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 446                                         fsp,
 447                                         (SMB_OFF_T)-1,
 448                                         N);
 449         }
 450
 451         while (total < N) {
 452                 ret = SMB_VFS_WRITE(fsp, buffer + total, N - total);
 453
 454                 if (ret == -1)
 455                         return -1;
 456                 if (ret == 0)
 457                         return total;
 458
 459                 total += ret;
 460         }
 461         return (ssize_t)total;
 462 }
 463
 464 ssize_t vfs_pwrite_data(struct smb_request *req,
 465                         files_struct *fsp,
 466                         const char *buffer,
 467                         size_t N,
 468                         SMB_OFF_T offset)
 469 {
 470         size_t total=0;
 471         ssize_t ret;
 472
 473         if (req && req->unread_bytes) {
 474                 SMB_ASSERT(req->unread_bytes == N);
 475                 /* VFS_RECVFILE must drain the socket
 476                  * before returning. */
 477                 req->unread_bytes = 0;
 478                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 479                                         fsp,
 480                                         offset,
 481                                         N);
 482         }
 483
 484         while (total < N) {
 485                 ret = SMB_VFS_PWRITE(fsp, buffer + total, N - total,
 486                                      offset + total);
 487
 488                 if (ret == -1)
 489                         return -1;
 490                 if (ret == 0)
 491                         return total;
 492
 493                 total += ret;
 494         }
 495         return (ssize_t)total;
 496 }
 497 /****************************************************************************
 498  An allocate file space call using the vfs interface.
 499  Allocates space for a file from a filedescriptor.
 500  Returns 0 on success, -1 on failure.
 501 ****************************************************************************/
 502
 503 int vfs_allocate_file_space(files_struct *fsp, uint64_t len)
 504 {
 505         int ret;
 506         SMB_STRUCT_STAT st;
 507         connection_struct *conn = fsp->conn;
 508         uint64_t space_avail;
 509         uint64_t bsize,dfree,dsize;
 510
 511         release_level_2_oplocks_on_change(fsp);
 512
 513         /*
 514          * Actually try and commit the space on disk....
 515          */
 516
 517         DEBUG(10,("vfs_allocate_file_space: file %s, len %.0f\n", fsp->fsp_name, (double)len ));
 518
 519         if (((SMB_OFF_T)len) < 0) {
 520                 DEBUG(0,("vfs_allocate_file_space: %s negative len requested.\n", fsp->fsp_name ));
 521                 errno = EINVAL;
 522                 return -1;
 523         }
 524
 525         ret = SMB_VFS_FSTAT(fsp, &st);
 526         if (ret == -1)
 527                 return ret;
 528
 529         if (len == (uint64_t)st.st_size)
 530                 return 0;
 531
 532         if (len < (uint64_t)st.st_size) {
 533                 /* Shrink - use ftruncate. */
 534
 535                 DEBUG(10,("vfs_allocate_file_space: file %s, shrink. Current size %.0f\n",
 536                                 fsp->fsp_name, (double)st.st_size ));
 537
 538                 flush_write_cache(fsp, SIZECHANGE_FLUSH);
 539                 if ((ret = SMB_VFS_FTRUNCATE(fsp, (SMB_OFF_T)len)) != -1) {
 540                         set_filelen_write_cache(fsp, len);
 541                 }
 542                 return ret;
 543         }
 544
 545         /* Grow - we need to test if we have enough space. */
 546
 547         if (!lp_strict_allocate(SNUM(fsp->conn)))
 548                 return 0;
 549
 550         len -= st.st_size;
 551         len /= 1024; /* Len is now number of 1k blocks needed. */
 552         space_avail = get_dfree_info(conn,fsp->fsp_name,False,&bsize,&dfree,&dsize);
 553         if (space_avail == (uint64_t)-1) {
 554                 return -1;
 555         }
 556
 557         DEBUG(10,("vfs_allocate_file_space: file %s, grow. Current size %.0f, needed blocks = %.0f, space avail = %.0f\n",
 558                         fsp->fsp_name, (double)st.st_size, (double)len, (double)space_avail ));
 559
 560         if (len > space_avail) {
 561                 errno = ENOSPC;
 562                 return -1;
 563         }
 564
 565         return 0;
 566 }
 567
 568 /****************************************************************************
 569  A vfs set_filelen call.
 570  set the length of a file from a filedescriptor.
 571  Returns 0 on success, -1 on failure.
 572 ****************************************************************************/
 573
 574 int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
 575 {
 576         int ret;
 577
 578         release_level_2_oplocks_on_change(fsp);
 579         DEBUG(10,("vfs_set_filelen: ftruncate %s to len %.0f\n", fsp->fsp_name, (double)len));
 580         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 581         if ((ret = SMB_VFS_FTRUNCATE(fsp, len)) != -1) {
 582                 set_filelen_write_cache(fsp, len);
 583                 notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
 584                              FILE_NOTIFY_CHANGE_SIZE
 585                              | FILE_NOTIFY_CHANGE_ATTRIBUTES,
 586                              fsp->fsp_name);
 587         }
 588
 589         return ret;
 590 }
 591
 592 /****************************************************************************
 593  A vfs fill sparse call.
 594  Writes zeros from the end of file to len, if len is greater than EOF.
 595  Used only by strict_sync.
 596  Returns 0 on success, -1 on failure.
 597 ****************************************************************************/
 598
 599 #define SPARSE_BUF_WRITE_SIZE (32*1024)
 600
 601 int vfs_fill_sparse(files_struct *fsp, SMB_OFF_T len)
 602 {
 603         int ret;
 604         SMB_STRUCT_STAT st;
 605         SMB_OFF_T offset;
 606         size_t total;
 607         size_t num_to_write;
 608         ssize_t pwrite_ret;
 609
 610         release_level_2_oplocks_on_change(fsp);
 611         ret = SMB_VFS_FSTAT(fsp, &st);
 612         if (ret == -1) {
 613                 return ret;
 614         }
 615
 616         if (len <= st.st_size) {
 617                 return 0;
 618         }
 619
 620         DEBUG(10,("vfs_fill_sparse: write zeros in file %s from len %.0f to len %.0f (%.0f bytes)\n",
 621                 fsp->fsp_name, (double)st.st_size, (double)len, (double)(len - st.st_size)));
 622
 623         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 624
 625         if (!sparse_buf) {
 626                 sparse_buf = SMB_CALLOC_ARRAY(char, SPARSE_BUF_WRITE_SIZE);
 627                 if (!sparse_buf) {
 628                         errno = ENOMEM;
 629                         return -1;
 630                 }
 631         }
 632
 633         offset = st.st_size;
 634         num_to_write = len - st.st_size;
 635         total = 0;
 636
 637         while (total < num_to_write) {
 638                 size_t curr_write_size = MIN(SPARSE_BUF_WRITE_SIZE, (num_to_write - total));
 639
 640                 pwrite_ret = SMB_VFS_PWRITE(fsp, sparse_buf, curr_write_size, offset + total);
 641                 if (pwrite_ret == -1) {
 642                         DEBUG(10,("vfs_fill_sparse: SMB_VFS_PWRITE for file %s failed with error %s\n",
 643                                 fsp->fsp_name, strerror(errno) ));
 644                         return -1;
 645                 }
 646                 if (pwrite_ret == 0) {
 647                         return 0;
 648                 }
 649
 650                 total += pwrite_ret;
 651         }
 652
 653         set_filelen_write_cache(fsp, len);
 654         return 0;
 655 }
 656
 657 /****************************************************************************
 658  Transfer some data (n bytes) between two file_struct's.
 659 ****************************************************************************/
 660
 661 static ssize_t vfs_read_fn(void *file, void *buf, size_t len)
 662 {
 663         struct files_struct *fsp = (struct files_struct *)file;
 664
 665         return SMB_VFS_READ(fsp, buf, len);
 666 }
 667
 668 static ssize_t vfs_write_fn(void *file, const void *buf, size_t len)
 669 {
 670         struct files_struct *fsp = (struct files_struct *)file;
 671
 672         return SMB_VFS_WRITE(fsp, buf, len);
 673 }
 674
 675 SMB_OFF_T vfs_transfer_file(files_struct *in, files_struct *out, SMB_OFF_T n)
 676 {
 677         return transfer_file_internal((void *)in, (void *)out, n,
 678                                       vfs_read_fn, vfs_write_fn);
 679 }
 680
 681 /*******************************************************************
 682  A vfs_readdir wrapper which just returns the file name.
 683 ********************************************************************/
 684
 685 char *vfs_readdirname(connection_struct *conn, void *p)
 686 {
 687         SMB_STRUCT_DIRENT *ptr= NULL;
 688         char *dname;
 689
 690         if (!p)
 691                 return(NULL);
 692
 693         ptr = SMB_VFS_READDIR(conn, (DIR *)p);
 694         if (!ptr)
 695                 return(NULL);
 696
 697         dname = ptr->d_name;
 698
 699 #ifdef NEXT2
 700         if (telldir(p) < 0)
 701                 return(NULL);
 702 #endif
 703
 704 #ifdef HAVE_BROKEN_READDIR_NAME
 705         /* using /usr/ucb/cc is BAD */
 706         dname = dname - 2;
 707 #endif
 708
 709         return(dname);
 710 }
 711
 712 /*******************************************************************
 713  A wrapper for vfs_chdir().
 714 ********************************************************************/
 715
 716 int vfs_ChDir(connection_struct *conn, const char *path)
 717 {
 718         int res;
 719
 720         if (!LastDir) {
 721                 LastDir = SMB_STRDUP("");
 722         }
 723
 724         if (strcsequal(path,"."))
 725                 return(0);
 726
 727         if (*path == '/' && strcsequal(LastDir,path))
 728                 return(0);
 729
 730         DEBUG(4,("vfs_ChDir to %s\n",path));
 731
 732         res = SMB_VFS_CHDIR(conn,path);
 733         if (!res) {
 734                 SAFE_FREE(LastDir);
 735                 LastDir = SMB_STRDUP(path);
 736         }
 737         return(res);
 738 }
 739
 740 /*******************************************************************
 741  Return the absolute current directory path - given a UNIX pathname.
 742  Note that this path is returned in DOS format, not UNIX
 743  format. Note this can be called with conn == NULL.
 744 ********************************************************************/
 745
 746 struct getwd_cache_key {
 747         SMB_DEV_T dev;
 748         SMB_INO_T ino;
 749 };
 750
 751 char *vfs_GetWd(TALLOC_CTX *ctx, connection_struct *conn)
 752 {
 753         char s[PATH_MAX+1];
 754         SMB_STRUCT_STAT st, st2;
 755         char *result;
 756         DATA_BLOB cache_value;
 757         struct getwd_cache_key key;
 758
 759         *s = 0;
 760
 761         if (!lp_getwd_cache()) {
 762                 goto nocache;
 763         }
 764
 765         SET_STAT_INVALID(st);
 766
 767         if (SMB_VFS_STAT(conn, ".",&st) == -1) {
 768                 /*
 769                  * Known to fail for root: the directory may be NFS-mounted
 770                  * and exported with root_squash (so has no root access).
 771                  */
 772                 DEBUG(1,("vfs_GetWd: couldn't stat \".\" error %s "
 773                          "(NFS problem ?)\n", strerror(errno) ));
 774                 goto nocache;
 775         }
 776
 777         ZERO_STRUCT(key); /* unlikely, but possible padding */
 778         key.dev = st.st_dev;
 779         key.ino = st.st_ino;
 780
 781         if (!memcache_lookup(smbd_memcache(), GETWD_CACHE,
 782                              data_blob_const(&key, sizeof(key)),
 783                              &cache_value)) {
 784                 goto nocache;
 785         }
 786
 787         SMB_ASSERT((cache_value.length > 0)
 788                    && (cache_value.data[cache_value.length-1] == '\0'));
 789
 790         if ((SMB_VFS_STAT(conn, (char *)cache_value.data, &st2) == 0)
 791             && (st.st_dev == st2.st_dev) && (st.st_ino == st2.st_ino)
 792             && (S_ISDIR(st.st_mode))) {
 793                 /*
 794                  * Ok, we're done
 795                  */
 796                 result = talloc_strdup(ctx, (char *)cache_value.data);
 797                 if (result == NULL) {
 798                         errno = ENOMEM;
 799                 }
 800                 return result;
 801         }
 802
 803  nocache:
 804
 805         /*
 806          * We don't have the information to hand so rely on traditional
 807          * methods. The very slow getcwd, which spawns a process on some
 808          * systems, or the not quite so bad getwd.
 809          */
 810
 811         if (!SMB_VFS_GETWD(conn,s)) {
 812                 DEBUG(0, ("vfs_GetWd: SMB_VFS_GETWD call failed: %s\n",
 813                           strerror(errno)));
 814                 return NULL;
 815         }
 816
 817         if (lp_getwd_cache() && VALID_STAT(st)) {
 818                 ZERO_STRUCT(key); /* unlikely, but possible padding */
 819                 key.dev = st.st_dev;
 820                 key.ino = st.st_ino;
 821
 822                 memcache_add(smbd_memcache(), GETWD_CACHE,
 823                              data_blob_const(&key, sizeof(key)),
 824                              data_blob_const(s, strlen(s)+1));
 825         }
 826
 827         result = talloc_strdup(ctx, s);
 828         if (result == NULL) {
 829                 errno = ENOMEM;
 830         }
 831         return result;
 832 }
 833
 834 /*******************************************************************
 835  Reduce a file name, removing .. elements and checking that
 836  it is below dir in the heirachy. This uses realpath.
 837 ********************************************************************/
 838
 839 NTSTATUS check_reduced_name(connection_struct *conn, const char *fname)
 840 {
 841 #ifdef REALPATH_TAKES_NULL
 842         bool free_resolved_name = True;
 843 #else
 844         char resolved_name_buf[PATH_MAX+1];
 845         bool free_resolved_name = False;
 846 #endif
 847         char *resolved_name = NULL;
 848         size_t con_path_len = strlen(conn->connectpath);
 849         char *p = NULL;
 850
 851         DEBUG(3,("reduce_name [%s] [%s]\n", fname, conn->connectpath));
 852
 853 #ifdef REALPATH_TAKES_NULL
 854         resolved_name = SMB_VFS_REALPATH(conn,fname,NULL);
 855 #else
 856         resolved_name = SMB_VFS_REALPATH(conn,fname,resolved_name_buf);
 857 #endif
 858
 859         if (!resolved_name) {
 860                 switch (errno) {
 861                         case ENOTDIR:
 862                                 DEBUG(3,("reduce_name: Component not a directory in getting realpath for %s\n", fname));
 863                                 return map_nt_error_from_unix(errno);
 864                         case ENOENT:
 865                         {
 866                                 TALLOC_CTX *ctx = talloc_tos();
 867                                 char *tmp_fname = NULL;
 868                                 char *last_component = NULL;
 869                                 /* Last component didn't exist. Remove it and try and canonicalise the directory. */
 870
 871                                 tmp_fname = talloc_strdup(ctx, fname);
 872                                 if (!tmp_fname) {
 873                                         return NT_STATUS_NO_MEMORY;
 874                                 }
 875                                 p = strrchr_m(tmp_fname, '/');
 876                                 if (p) {
 877                                         *p++ = '\0';
 878                                         last_component = p;
 879                                 } else {
 880                                         last_component = tmp_fname;
 881                                         tmp_fname = talloc_strdup(ctx,
 882                                                         ".");
 883                                         if (!tmp_fname) {
 884                                                 return NT_STATUS_NO_MEMORY;
 885                                         }
 886                                 }
 887
 888 #ifdef REALPATH_TAKES_NULL
 889                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,NULL);
 890 #else
 891                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,resolved_name_buf);
 892 #endif
 893                                 if (!resolved_name) {
 894                                         DEBUG(3,("reduce_name: couldn't get realpath for %s\n", fname));
 895                                         return map_nt_error_from_unix(errno);
 896                                 }
 897                                 tmp_fname = talloc_asprintf(ctx,
 898                                                 "%s/%s",
 899                                                 resolved_name,
 900                                                 last_component);
 901                                 if (!tmp_fname) {
 902                                         return NT_STATUS_NO_MEMORY;
 903                                 }
 904 #ifdef REALPATH_TAKES_NULL
 905                                 SAFE_FREE(resolved_name);
 906                                 resolved_name = SMB_STRDUP(tmp_fname);
 907                                 if (!resolved_name) {
 908                                         DEBUG(0,("reduce_name: malloc fail for %s\n", tmp_fname));
 909                                         return NT_STATUS_NO_MEMORY;
 910                                 }
 911 #else
 912                                 safe_strcpy(resolved_name_buf, tmp_fname, PATH_MAX);
 913                                 resolved_name = resolved_name_buf;
 914 #endif
 915                                 break;
 916                         }
 917                         default:
 918                                 DEBUG(1,("reduce_name: couldn't get realpath for %s\n", fname));
 919                                 return map_nt_error_from_unix(errno);
 920                 }
 921         }
 922
 923         DEBUG(10,("reduce_name realpath [%s] -> [%s]\n", fname, resolved_name));
 924
 925         if (*resolved_name != '/') {
 926                 DEBUG(0,("reduce_name: realpath doesn't return absolute paths !\n"));
 927                 if (free_resolved_name) {
 928                         SAFE_FREE(resolved_name);
 929                 }
 930                 return NT_STATUS_OBJECT_NAME_INVALID;
 931         }
 932
 933         /* Check for widelinks allowed. */
 934         if (!lp_widelinks(SNUM(conn)) && (strncmp(conn->connectpath, resolved_name, con_path_len) != 0)) {
 935                 DEBUG(2, ("reduce_name: Bad access attempt: %s is a symlink outside the share path", fname));
 936                 if (free_resolved_name) {
 937                         SAFE_FREE(resolved_name);
 938                 }
 939                 return NT_STATUS_ACCESS_DENIED;
 940         }
 941
 942         /* Check if we are allowing users to follow symlinks */
 943         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 944                 University of Geneva */
 945
 946 #ifdef S_ISLNK
 947         if (!lp_symlinks(SNUM(conn))) {
 948                 SMB_STRUCT_STAT statbuf;
 949                 if ( (SMB_VFS_LSTAT(conn,fname,&statbuf) != -1) &&
 950                                 (S_ISLNK(statbuf.st_mode)) ) {
 951                         if (free_resolved_name) {
 952                                 SAFE_FREE(resolved_name);
 953                         }
 954                         DEBUG(3,("reduce_name: denied: file path name %s is a symlink\n",resolved_name));
 955                         return NT_STATUS_ACCESS_DENIED;
 956                 }
 957         }
 958 #endif
 959
 960         DEBUG(3,("reduce_name: %s reduced to %s\n", fname, resolved_name));
 961         if (free_resolved_name) {
 962                 SAFE_FREE(resolved_name);
 963         }
 964         return NT_STATUS_OK;
 965 }