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         entry = vfs_find_backend_entry(module_name);
 165         if (!entry) {
 166                 NTSTATUS status;
 167
 168                 DEBUG(5, ("vfs module [%s] not loaded - trying to load...\n",
 169                           vfs_object));
 170
 171                 status = smb_probe_module("vfs", module_path);
 172                 if (!NT_STATUS_IS_OK(status)) {
 173                         DEBUG(0, ("error probing vfs module '%s': %s\n",
 174                                   module_path, nt_errstr(status)));
 175                         goto fail;
 176                 }
 177
 178                 entry = vfs_find_backend_entry(module_name);
 179                 if (!entry) {
 180                         DEBUG(0,("Can't find a vfs module [%s]\n",vfs_object));
 181                         goto fail;
 182                 }
 183         }
 184
 185         DEBUGADD(5,("Successfully loaded vfs module [%s] with the new modules system\n", vfs_object));
 186         if ((ops = entry->vfs_op_tuples) == NULL) {
 187                 DEBUG(0, ("entry->vfs_op_tuples==NULL for [%s] failed\n", vfs_object));
 188                 goto fail;
 189         }
 190
 191         handle = TALLOC_ZERO_P(conn, vfs_handle_struct);
 192         if (!handle) {
 193                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 194                 goto fail;
 195         }
 196         memcpy(&handle->vfs_next, &conn->vfs, sizeof(struct vfs_ops));
 197         handle->conn = conn;
 198         if (module_param) {
 199                 handle->param = talloc_strdup(conn, module_param);
 200         }
 201         DLIST_ADD(conn->vfs_handles, handle);
 202
 203         for(i=0; ops[i].op != NULL; i++) {
 204                 DEBUG(5, ("Checking operation #%d (type %d, layer %d)\n", i, ops[i].type, ops[i].layer));
 205                 if(ops[i].layer == SMB_VFS_LAYER_OPAQUE) {
 206                         /* If this operation was already made opaque by different module, it
 207                          * will be overridden here.
 208                          */
 209                         DEBUGADD(5, ("Making operation type %d opaque [module %s]\n", ops[i].type, vfs_object));
 210                         vfs_set_operation(&conn->vfs_opaque, ops[i].type, handle, ops[i].op);
 211                 }
 212                 /* Change current VFS disposition*/
 213                 DEBUGADD(5, ("Accepting operation type %d from module %s\n", ops[i].type, vfs_object));
 214                 vfs_set_operation(&conn->vfs, ops[i].type, handle, ops[i].op);
 215         }
 216
 217         SAFE_FREE(module_path);
 218         SAFE_FREE(module_name);
 219         return True;
 220
 221  fail:
 222         SAFE_FREE(module_path);
 223         SAFE_FREE(module_name);
 224         return False;
 225 }
 226
 227 /*****************************************************************
 228  Allow VFS modules to extend files_struct with VFS-specific state.
 229  This will be ok for small numbers of extensions, but might need to
 230  be refactored if it becomes more widely used.
 231 ******************************************************************/
 232
 233 #define EXT_DATA_AREA(e) ((uint8 *)(e) + sizeof(struct vfs_fsp_data))
 234
 235 void *vfs_add_fsp_extension_notype(vfs_handle_struct *handle,
 236                                    files_struct *fsp, size_t ext_size,
 237                                    void (*destroy_fn)(void *p_data))
 238 {
 239         struct vfs_fsp_data *ext;
 240         void * ext_data;
 241
 242         /* Prevent VFS modules adding multiple extensions. */
 243         if ((ext_data = vfs_fetch_fsp_extension(handle, fsp))) {
 244                 return ext_data;
 245         }
 246
 247         ext = (struct vfs_fsp_data *)TALLOC_ZERO(
 248                 handle->conn, sizeof(struct vfs_fsp_data) + ext_size);
 249         if (ext == NULL) {
 250                 return NULL;
 251         }
 252
 253         ext->owner = handle;
 254         ext->next = fsp->vfs_extension;
 255         ext->destroy = destroy_fn;
 256         fsp->vfs_extension = ext;
 257         return EXT_DATA_AREA(ext);
 258 }
 259
 260 void vfs_remove_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 261 {
 262         struct vfs_fsp_data *curr;
 263         struct vfs_fsp_data *prev;
 264
 265         for (curr = fsp->vfs_extension, prev = NULL;
 266              curr;
 267              prev = curr, curr = curr->next) {
 268                 if (curr->owner == handle) {
 269                     if (prev) {
 270                             prev->next = curr->next;
 271                     } else {
 272                             fsp->vfs_extension = curr->next;
 273                     }
 274                     if (curr->destroy) {
 275                             curr->destroy(EXT_DATA_AREA(curr));
 276                     }
 277                     TALLOC_FREE(curr);
 278                     return;
 279                 }
 280         }
 281 }
 282
 283 void *vfs_memctx_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 284 {
 285         struct vfs_fsp_data *head;
 286
 287         for (head = fsp->vfs_extension; head; head = head->next) {
 288                 if (head->owner == handle) {
 289                         return head;
 290                 }
 291         }
 292
 293         return NULL;
 294 }
 295
 296 void *vfs_fetch_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 297 {
 298         struct vfs_fsp_data *head;
 299
 300         head = (struct vfs_fsp_data *)vfs_memctx_fsp_extension(handle, fsp);
 301         if (head != NULL) {
 302                 return EXT_DATA_AREA(head);
 303         }
 304
 305         return NULL;
 306 }
 307
 308 #undef EXT_DATA_AREA
 309
 310 /*****************************************************************
 311  Generic VFS init.
 312 ******************************************************************/
 313
 314 bool smbd_vfs_init(connection_struct *conn)
 315 {
 316         const char **vfs_objects;
 317         unsigned int i = 0;
 318         int j = 0;
 319
 320         /* Normal share - initialise with disk access functions */
 321         vfs_init_default(conn);
 322         vfs_objects = lp_vfs_objects(SNUM(conn));
 323
 324         /* Override VFS functions if 'vfs object' was not specified*/
 325         if (!vfs_objects || !vfs_objects[0])
 326                 return True;
 327
 328         for (i=0; vfs_objects[i] ;) {
 329                 i++;
 330         }
 331
 332         for (j=i-1; j >= 0; j--) {
 333                 if (!vfs_init_custom(conn, vfs_objects[j])) {
 334                         DEBUG(0, ("smbd_vfs_init: vfs_init_custom failed for %s\n", vfs_objects[j]));
 335                         return False;
 336                 }
 337         }
 338         return True;
 339 }
 340
 341 /*******************************************************************
 342  Check if directory exists.
 343 ********************************************************************/
 344
 345 bool vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
 346 {
 347         SMB_STRUCT_STAT st2;
 348         bool ret;
 349
 350         if (!st)
 351                 st = &st2;
 352
 353         if (SMB_VFS_STAT(conn,dname,st) != 0)
 354                 return(False);
 355
 356         ret = S_ISDIR(st->st_mode);
 357         if(!ret)
 358                 errno = ENOTDIR;
 359
 360         return ret;
 361 }
 362
 363 /*******************************************************************
 364  Check if an object exists in the vfs.
 365 ********************************************************************/
 366
 367 bool vfs_object_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 True;
 379 }
 380
 381 /*******************************************************************
 382  Check if a file exists in the vfs.
 383 ********************************************************************/
 384
 385 bool vfs_file_exist(connection_struct *conn, const char *fname,SMB_STRUCT_STAT *sbuf)
 386 {
 387         SMB_STRUCT_STAT st;
 388
 389         if (!sbuf)
 390                 sbuf = &st;
 391
 392         ZERO_STRUCTP(sbuf);
 393
 394         if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
 395                 return False;
 396         return(S_ISREG(sbuf->st_mode));
 397 }
 398
 399 /****************************************************************************
 400  Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
 401 ****************************************************************************/
 402
 403 ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
 404 {
 405         size_t total=0;
 406
 407         while (total < byte_count)
 408         {
 409                 ssize_t ret = SMB_VFS_READ(fsp, buf + total,
 410                                            byte_count - total);
 411
 412                 if (ret == 0) return total;
 413                 if (ret == -1) {
 414                         if (errno == EINTR)
 415                                 continue;
 416                         else
 417                                 return -1;
 418                 }
 419                 total += ret;
 420         }
 421         return (ssize_t)total;
 422 }
 423
 424 ssize_t vfs_pread_data(files_struct *fsp, char *buf,
 425                 size_t byte_count, SMB_OFF_T offset)
 426 {
 427         size_t total=0;
 428
 429         while (total < byte_count)
 430         {
 431                 ssize_t ret = SMB_VFS_PREAD(fsp, buf + total,
 432                                         byte_count - total, offset + total);
 433
 434                 if (ret == 0) return total;
 435                 if (ret == -1) {
 436                         if (errno == EINTR)
 437                                 continue;
 438                         else
 439                                 return -1;
 440                 }
 441                 total += ret;
 442         }
 443         return (ssize_t)total;
 444 }
 445
 446 /****************************************************************************
 447  Write data to a fd on the vfs.
 448 ****************************************************************************/
 449
 450 ssize_t vfs_write_data(struct smb_request *req,
 451                         files_struct *fsp,
 452                         const char *buffer,
 453                         size_t N)
 454 {
 455         size_t total=0;
 456         ssize_t ret;
 457
 458         if (req && req->unread_bytes) {
 459                 SMB_ASSERT(req->unread_bytes == N);
 460                 /* VFS_RECVFILE must drain the socket
 461                  * before returning. */
 462                 req->unread_bytes = 0;
 463                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 464                                         fsp,
 465                                         (SMB_OFF_T)-1,
 466                                         N);
 467         }
 468
 469         while (total < N) {
 470                 ret = SMB_VFS_WRITE(fsp, buffer + total, N - total);
 471
 472                 if (ret == -1)
 473                         return -1;
 474                 if (ret == 0)
 475                         return total;
 476
 477                 total += ret;
 478         }
 479         return (ssize_t)total;
 480 }
 481
 482 ssize_t vfs_pwrite_data(struct smb_request *req,
 483                         files_struct *fsp,
 484                         const char *buffer,
 485                         size_t N,
 486                         SMB_OFF_T offset)
 487 {
 488         size_t total=0;
 489         ssize_t ret;
 490
 491         if (req && req->unread_bytes) {
 492                 SMB_ASSERT(req->unread_bytes == N);
 493                 /* VFS_RECVFILE must drain the socket
 494                  * before returning. */
 495                 req->unread_bytes = 0;
 496                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 497                                         fsp,
 498                                         offset,
 499                                         N);
 500         }
 501
 502         while (total < N) {
 503                 ret = SMB_VFS_PWRITE(fsp, buffer + total, N - total,
 504                                      offset + total);
 505
 506                 if (ret == -1)
 507                         return -1;
 508                 if (ret == 0)
 509                         return total;
 510
 511                 total += ret;
 512         }
 513         return (ssize_t)total;
 514 }
 515 /****************************************************************************
 516  An allocate file space call using the vfs interface.
 517  Allocates space for a file from a filedescriptor.
 518  Returns 0 on success, -1 on failure.
 519 ****************************************************************************/
 520
 521 int vfs_allocate_file_space(files_struct *fsp, uint64_t len)
 522 {
 523         int ret;
 524         SMB_STRUCT_STAT st;
 525         connection_struct *conn = fsp->conn;
 526         uint64_t space_avail;
 527         uint64_t bsize,dfree,dsize;
 528
 529         /*
 530          * Actually try and commit the space on disk....
 531          */
 532
 533         DEBUG(10,("vfs_allocate_file_space: file %s, len %.0f\n", fsp->fsp_name, (double)len ));
 534
 535         if (((SMB_OFF_T)len) < 0) {
 536                 DEBUG(0,("vfs_allocate_file_space: %s negative len requested.\n", fsp->fsp_name ));
 537                 errno = EINVAL;
 538                 return -1;
 539         }
 540
 541         ret = SMB_VFS_FSTAT(fsp, &st);
 542         if (ret == -1)
 543                 return ret;
 544
 545         if (len == (uint64_t)st.st_size)
 546                 return 0;
 547
 548         if (len < (uint64_t)st.st_size) {
 549                 /* Shrink - use ftruncate. */
 550
 551                 DEBUG(10,("vfs_allocate_file_space: file %s, shrink. Current size %.0f\n",
 552                                 fsp->fsp_name, (double)st.st_size ));
 553
 554                 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_ALLOC_SHRINK);
 555
 556                 flush_write_cache(fsp, SIZECHANGE_FLUSH);
 557                 if ((ret = SMB_VFS_FTRUNCATE(fsp, (SMB_OFF_T)len)) != -1) {
 558                         set_filelen_write_cache(fsp, len);
 559                 }
 560
 561                 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_ALLOC_SHRINK);
 562
 563                 return ret;
 564         }
 565
 566         /* Grow - we need to test if we have enough space. */
 567
 568         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_ALLOC_GROW);
 569         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_ALLOC_GROW);
 570
 571         if (!lp_strict_allocate(SNUM(fsp->conn)))
 572                 return 0;
 573
 574         len -= st.st_size;
 575         len /= 1024; /* Len is now number of 1k blocks needed. */
 576         space_avail = get_dfree_info(conn,fsp->fsp_name,False,&bsize,&dfree,&dsize);
 577         if (space_avail == (uint64_t)-1) {
 578                 return -1;
 579         }
 580
 581         DEBUG(10,("vfs_allocate_file_space: file %s, grow. Current size %.0f, needed blocks = %.0f, space avail = %.0f\n",
 582                         fsp->fsp_name, (double)st.st_size, (double)len, (double)space_avail ));
 583
 584         if (len > space_avail) {
 585                 errno = ENOSPC;
 586                 return -1;
 587         }
 588
 589         return 0;
 590 }
 591
 592 /****************************************************************************
 593  A vfs set_filelen call.
 594  set the length of a file from a filedescriptor.
 595  Returns 0 on success, -1 on failure.
 596 ****************************************************************************/
 597
 598 int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
 599 {
 600         int ret;
 601
 602         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_SET_FILE_LEN);
 603
 604         DEBUG(10,("vfs_set_filelen: ftruncate %s to len %.0f\n", fsp->fsp_name, (double)len));
 605         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 606         if ((ret = SMB_VFS_FTRUNCATE(fsp, len)) != -1) {
 607                 set_filelen_write_cache(fsp, len);
 608                 notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
 609                              FILE_NOTIFY_CHANGE_SIZE
 610                              | FILE_NOTIFY_CHANGE_ATTRIBUTES,
 611                              fsp->fsp_name);
 612         }
 613
 614         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_SET_FILE_LEN);
 615
 616         return ret;
 617 }
 618
 619 /****************************************************************************
 620  A vfs fill sparse call.
 621  Writes zeros from the end of file to len, if len is greater than EOF.
 622  Used only by strict_sync.
 623  Returns 0 on success, -1 on failure.
 624 ****************************************************************************/
 625
 626 #define SPARSE_BUF_WRITE_SIZE (32*1024)
 627
 628 int vfs_fill_sparse(files_struct *fsp, SMB_OFF_T len)
 629 {
 630         int ret;
 631         SMB_STRUCT_STAT st;
 632         SMB_OFF_T offset;
 633         size_t total;
 634         size_t num_to_write;
 635         ssize_t pwrite_ret;
 636
 637         ret = SMB_VFS_FSTAT(fsp, &st);
 638         if (ret == -1) {
 639                 return ret;
 640         }
 641
 642         if (len <= st.st_size) {
 643                 return 0;
 644         }
 645
 646         DEBUG(10,("vfs_fill_sparse: write zeros in file %s from len %.0f to len %.0f (%.0f bytes)\n",
 647                 fsp->fsp_name, (double)st.st_size, (double)len, (double)(len - st.st_size)));
 648
 649         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_FILL_SPARSE);
 650
 651         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 652
 653         if (!sparse_buf) {
 654                 sparse_buf = SMB_CALLOC_ARRAY(char, SPARSE_BUF_WRITE_SIZE);
 655                 if (!sparse_buf) {
 656                         errno = ENOMEM;
 657                         ret = -1;
 658                         goto out;
 659                 }
 660         }
 661
 662         offset = st.st_size;
 663         num_to_write = len - st.st_size;
 664         total = 0;
 665
 666         while (total < num_to_write) {
 667                 size_t curr_write_size = MIN(SPARSE_BUF_WRITE_SIZE, (num_to_write - total));
 668
 669                 pwrite_ret = SMB_VFS_PWRITE(fsp, sparse_buf, curr_write_size, offset + total);
 670                 if (pwrite_ret == -1) {
 671                         DEBUG(10,("vfs_fill_sparse: SMB_VFS_PWRITE for file %s failed with error %s\n",
 672                                 fsp->fsp_name, strerror(errno) ));
 673                         ret = -1;
 674                         goto out;
 675                 }
 676                 if (pwrite_ret == 0) {
 677                         ret = 0;
 678                         goto out;
 679                 }
 680
 681                 total += pwrite_ret;
 682         }
 683
 684         set_filelen_write_cache(fsp, len);
 685
 686         ret = 0;
 687  out:
 688         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_FILL_SPARSE);
 689         return ret;
 690 }
 691
 692 /****************************************************************************
 693  Transfer some data (n bytes) between two file_struct's.
 694 ****************************************************************************/
 695
 696 static ssize_t vfs_read_fn(void *file, void *buf, size_t len)
 697 {
 698         struct files_struct *fsp = (struct files_struct *)file;
 699
 700         return SMB_VFS_READ(fsp, buf, len);
 701 }
 702
 703 static ssize_t vfs_write_fn(void *file, const void *buf, size_t len)
 704 {
 705         struct files_struct *fsp = (struct files_struct *)file;
 706
 707         return SMB_VFS_WRITE(fsp, buf, len);
 708 }
 709
 710 SMB_OFF_T vfs_transfer_file(files_struct *in, files_struct *out, SMB_OFF_T n)
 711 {
 712         return transfer_file_internal((void *)in, (void *)out, n,
 713                                       vfs_read_fn, vfs_write_fn);
 714 }
 715
 716 /*******************************************************************
 717  A vfs_readdir wrapper which just returns the file name.
 718 ********************************************************************/
 719
 720 char *vfs_readdirname(connection_struct *conn, void *p, SMB_STRUCT_STAT *sbuf)
 721 {
 722         SMB_STRUCT_DIRENT *ptr= NULL;
 723         char *dname;
 724
 725         if (!p)
 726                 return(NULL);
 727
 728         ptr = SMB_VFS_READDIR(conn, (DIR *)p, sbuf);
 729         if (!ptr)
 730                 return(NULL);
 731
 732         dname = ptr->d_name;
 733
 734 #ifdef NEXT2
 735         if (telldir(p) < 0)
 736                 return(NULL);
 737 #endif
 738
 739 #ifdef HAVE_BROKEN_READDIR_NAME
 740         /* using /usr/ucb/cc is BAD */
 741         dname = dname - 2;
 742 #endif
 743
 744         return(dname);
 745 }
 746
 747 /*******************************************************************
 748  A wrapper for vfs_chdir().
 749 ********************************************************************/
 750
 751 int vfs_ChDir(connection_struct *conn, const char *path)
 752 {
 753         int res;
 754
 755         if (!LastDir) {
 756                 LastDir = SMB_STRDUP("");
 757         }
 758
 759         if (strcsequal(path,"."))
 760                 return(0);
 761
 762         if (*path == '/' && strcsequal(LastDir,path))
 763                 return(0);
 764
 765         DEBUG(4,("vfs_ChDir to %s\n",path));
 766
 767         res = SMB_VFS_CHDIR(conn,path);
 768         if (!res) {
 769                 SAFE_FREE(LastDir);
 770                 LastDir = SMB_STRDUP(path);
 771         }
 772         return(res);
 773 }
 774
 775 /*******************************************************************
 776  Return the absolute current directory path - given a UNIX pathname.
 777  Note that this path is returned in DOS format, not UNIX
 778  format. Note this can be called with conn == NULL.
 779 ********************************************************************/
 780
 781 char *vfs_GetWd(TALLOC_CTX *ctx, connection_struct *conn)
 782 {
 783         char s[PATH_MAX+1];
 784         SMB_STRUCT_STAT st, st2;
 785         char *result;
 786         DATA_BLOB cache_value;
 787         struct file_id key;
 788
 789         *s = 0;
 790
 791         if (!lp_getwd_cache()) {
 792                 goto nocache;
 793         }
 794
 795         SET_STAT_INVALID(st);
 796
 797         if (SMB_VFS_STAT(conn, ".",&st) == -1) {
 798                 /*
 799                  * Known to fail for root: the directory may be NFS-mounted
 800                  * and exported with root_squash (so has no root access).
 801                  */
 802                 DEBUG(1,("vfs_GetWd: couldn't stat \".\" error %s "
 803                          "(NFS problem ?)\n", strerror(errno) ));
 804                 goto nocache;
 805         }
 806
 807         key = vfs_file_id_from_sbuf(conn, &st);
 808
 809         if (!memcache_lookup(smbd_memcache(), GETWD_CACHE,
 810                              data_blob_const(&key, sizeof(key)),
 811                              &cache_value)) {
 812                 goto nocache;
 813         }
 814
 815         SMB_ASSERT((cache_value.length > 0)
 816                    && (cache_value.data[cache_value.length-1] == '\0'));
 817
 818         if ((SMB_VFS_STAT(conn, (char *)cache_value.data, &st2) == 0)
 819             && (st.st_dev == st2.st_dev) && (st.st_ino == st2.st_ino)
 820             && (S_ISDIR(st.st_mode))) {
 821                 /*
 822                  * Ok, we're done
 823                  */
 824                 result = talloc_strdup(ctx, (char *)cache_value.data);
 825                 if (result == NULL) {
 826                         errno = ENOMEM;
 827                 }
 828                 return result;
 829         }
 830
 831  nocache:
 832
 833         /*
 834          * We don't have the information to hand so rely on traditional
 835          * methods. The very slow getcwd, which spawns a process on some
 836          * systems, or the not quite so bad getwd.
 837          */
 838
 839         if (!SMB_VFS_GETWD(conn,s)) {
 840                 DEBUG(0, ("vfs_GetWd: SMB_VFS_GETWD call failed: %s\n",
 841                           strerror(errno)));
 842                 return NULL;
 843         }
 844
 845         if (lp_getwd_cache() && VALID_STAT(st)) {
 846                 key = vfs_file_id_from_sbuf(conn, &st);
 847
 848                 memcache_add(smbd_memcache(), GETWD_CACHE,
 849                              data_blob_const(&key, sizeof(key)),
 850                              data_blob_const(s, strlen(s)+1));
 851         }
 852
 853         result = talloc_strdup(ctx, s);
 854         if (result == NULL) {
 855                 errno = ENOMEM;
 856         }
 857         return result;
 858 }
 859
 860 /*******************************************************************
 861  Reduce a file name, removing .. elements and checking that
 862  it is below dir in the heirachy. This uses realpath.
 863 ********************************************************************/
 864
 865 NTSTATUS check_reduced_name(connection_struct *conn, const char *fname)
 866 {
 867 #ifdef REALPATH_TAKES_NULL
 868         bool free_resolved_name = True;
 869 #else
 870         char resolved_name_buf[PATH_MAX+1];
 871         bool free_resolved_name = False;
 872 #endif
 873         char *resolved_name = NULL;
 874         size_t con_path_len = strlen(conn->connectpath);
 875         char *p = NULL;
 876
 877         DEBUG(3,("reduce_name [%s] [%s]\n", fname, conn->connectpath));
 878
 879 #ifdef REALPATH_TAKES_NULL
 880         resolved_name = SMB_VFS_REALPATH(conn,fname,NULL);
 881 #else
 882         resolved_name = SMB_VFS_REALPATH(conn,fname,resolved_name_buf);
 883 #endif
 884
 885         if (!resolved_name) {
 886                 switch (errno) {
 887                         case ENOTDIR:
 888                                 DEBUG(3,("reduce_name: Component not a directory in getting realpath for %s\n", fname));
 889                                 return map_nt_error_from_unix(errno);
 890                         case ENOENT:
 891                         {
 892                                 TALLOC_CTX *ctx = talloc_tos();
 893                                 char *tmp_fname = NULL;
 894                                 char *last_component = NULL;
 895                                 /* Last component didn't exist. Remove it and try and canonicalise the directory. */
 896
 897                                 tmp_fname = talloc_strdup(ctx, fname);
 898                                 if (!tmp_fname) {
 899                                         return NT_STATUS_NO_MEMORY;
 900                                 }
 901                                 p = strrchr_m(tmp_fname, '/');
 902                                 if (p) {
 903                                         *p++ = '\0';
 904                                         last_component = p;
 905                                 } else {
 906                                         last_component = tmp_fname;
 907                                         tmp_fname = talloc_strdup(ctx,
 908                                                         ".");
 909                                         if (!tmp_fname) {
 910                                                 return NT_STATUS_NO_MEMORY;
 911                                         }
 912                                 }
 913
 914 #ifdef REALPATH_TAKES_NULL
 915                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,NULL);
 916 #else
 917                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,resolved_name_buf);
 918 #endif
 919                                 if (!resolved_name) {
 920                                         DEBUG(3,("reduce_name: couldn't get realpath for %s\n", fname));
 921                                         return map_nt_error_from_unix(errno);
 922                                 }
 923                                 tmp_fname = talloc_asprintf(ctx,
 924                                                 "%s/%s",
 925                                                 resolved_name,
 926                                                 last_component);
 927                                 if (!tmp_fname) {
 928                                         return NT_STATUS_NO_MEMORY;
 929                                 }
 930 #ifdef REALPATH_TAKES_NULL
 931                                 SAFE_FREE(resolved_name);
 932                                 resolved_name = SMB_STRDUP(tmp_fname);
 933                                 if (!resolved_name) {
 934                                         DEBUG(0,("reduce_name: malloc fail for %s\n", tmp_fname));
 935                                         return NT_STATUS_NO_MEMORY;
 936                                 }
 937 #else
 938                                 safe_strcpy(resolved_name_buf, tmp_fname, PATH_MAX);
 939                                 resolved_name = resolved_name_buf;
 940 #endif
 941                                 break;
 942                         }
 943                         default:
 944                                 DEBUG(1,("reduce_name: couldn't get realpath for %s\n", fname));
 945                                 return map_nt_error_from_unix(errno);
 946                 }
 947         }
 948
 949         DEBUG(10,("reduce_name realpath [%s] -> [%s]\n", fname, resolved_name));
 950
 951         if (*resolved_name != '/') {
 952                 DEBUG(0,("reduce_name: realpath doesn't return absolute paths !\n"));
 953                 if (free_resolved_name) {
 954                         SAFE_FREE(resolved_name);
 955                 }
 956                 return NT_STATUS_OBJECT_NAME_INVALID;
 957         }
 958
 959         /* Check for widelinks allowed. */
 960         if (!lp_widelinks(SNUM(conn)) && (strncmp(conn->connectpath, resolved_name, con_path_len) != 0)) {
 961                 DEBUG(2, ("reduce_name: Bad access attempt: %s is a symlink outside the share path", fname));
 962                 if (free_resolved_name) {
 963                         SAFE_FREE(resolved_name);
 964                 }
 965                 return NT_STATUS_ACCESS_DENIED;
 966         }
 967
 968         /* Check if we are allowing users to follow symlinks */
 969         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 970                 University of Geneva */
 971
 972 #ifdef S_ISLNK
 973         if (!lp_symlinks(SNUM(conn))) {
 974                 SMB_STRUCT_STAT statbuf;
 975                 if ( (SMB_VFS_LSTAT(conn,fname,&statbuf) != -1) &&
 976                                 (S_ISLNK(statbuf.st_mode)) ) {
 977                         if (free_resolved_name) {
 978                                 SAFE_FREE(resolved_name);
 979                         }
 980                         DEBUG(3,("reduce_name: denied: file path name %s is a symlink\n",resolved_name));
 981                         return NT_STATUS_ACCESS_DENIED;
 982                 }
 983         }
 984 #endif
 985
 986         DEBUG(3,("reduce_name: %s reduced to %s\n", fname, resolved_name));
 987         if (free_resolved_name) {
 988                 SAFE_FREE(resolved_name);
 989         }
 990         return NT_STATUS_OK;
 991 }