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 a file exists in the vfs.
 343 ********************************************************************/
 344
 345 NTSTATUS vfs_file_exist(connection_struct *conn, struct smb_filename *smb_fname)
 346 {
 347         /* Only return OK if stat was successful and S_ISREG */
 348         if ((SMB_VFS_STAT(conn, smb_fname) != -1) &&
 349             S_ISREG(smb_fname->st.st_ex_mode)) {
 350                 return NT_STATUS_OK;
 351         }
 352
 353         return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 354 }
 355
 356 /****************************************************************************
 357  Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
 358 ****************************************************************************/
 359
 360 ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
 361 {
 362         size_t total=0;
 363
 364         while (total < byte_count)
 365         {
 366                 ssize_t ret = SMB_VFS_READ(fsp, buf + total,
 367                                            byte_count - total);
 368
 369                 if (ret == 0) return total;
 370                 if (ret == -1) {
 371                         if (errno == EINTR)
 372                                 continue;
 373                         else
 374                                 return -1;
 375                 }
 376                 total += ret;
 377         }
 378         return (ssize_t)total;
 379 }
 380
 381 ssize_t vfs_pread_data(files_struct *fsp, char *buf,
 382                 size_t byte_count, SMB_OFF_T offset)
 383 {
 384         size_t total=0;
 385
 386         while (total < byte_count)
 387         {
 388                 ssize_t ret = SMB_VFS_PREAD(fsp, buf + total,
 389                                         byte_count - total, offset + total);
 390
 391                 if (ret == 0) return total;
 392                 if (ret == -1) {
 393                         if (errno == EINTR)
 394                                 continue;
 395                         else
 396                                 return -1;
 397                 }
 398                 total += ret;
 399         }
 400         return (ssize_t)total;
 401 }
 402
 403 /****************************************************************************
 404  Write data to a fd on the vfs.
 405 ****************************************************************************/
 406
 407 ssize_t vfs_write_data(struct smb_request *req,
 408                         files_struct *fsp,
 409                         const char *buffer,
 410                         size_t N)
 411 {
 412         size_t total=0;
 413         ssize_t ret;
 414
 415         if (req && req->unread_bytes) {
 416                 SMB_ASSERT(req->unread_bytes == N);
 417                 /* VFS_RECVFILE must drain the socket
 418                  * before returning. */
 419                 req->unread_bytes = 0;
 420                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 421                                         fsp,
 422                                         (SMB_OFF_T)-1,
 423                                         N);
 424         }
 425
 426         while (total < N) {
 427                 ret = SMB_VFS_WRITE(fsp, buffer + total, N - total);
 428
 429                 if (ret == -1)
 430                         return -1;
 431                 if (ret == 0)
 432                         return total;
 433
 434                 total += ret;
 435         }
 436         return (ssize_t)total;
 437 }
 438
 439 ssize_t vfs_pwrite_data(struct smb_request *req,
 440                         files_struct *fsp,
 441                         const char *buffer,
 442                         size_t N,
 443                         SMB_OFF_T offset)
 444 {
 445         size_t total=0;
 446         ssize_t ret;
 447
 448         if (req && req->unread_bytes) {
 449                 SMB_ASSERT(req->unread_bytes == N);
 450                 /* VFS_RECVFILE must drain the socket
 451                  * before returning. */
 452                 req->unread_bytes = 0;
 453                 return SMB_VFS_RECVFILE(smbd_server_fd(),
 454                                         fsp,
 455                                         offset,
 456                                         N);
 457         }
 458
 459         while (total < N) {
 460                 ret = SMB_VFS_PWRITE(fsp, buffer + total, N - total,
 461                                      offset + total);
 462
 463                 if (ret == -1)
 464                         return -1;
 465                 if (ret == 0)
 466                         return total;
 467
 468                 total += ret;
 469         }
 470         return (ssize_t)total;
 471 }
 472 /****************************************************************************
 473  An allocate file space call using the vfs interface.
 474  Allocates space for a file from a filedescriptor.
 475  Returns 0 on success, -1 on failure.
 476 ****************************************************************************/
 477
 478 int vfs_allocate_file_space(files_struct *fsp, uint64_t len)
 479 {
 480         int ret;
 481         SMB_STRUCT_STAT st;
 482         connection_struct *conn = fsp->conn;
 483         uint64_t space_avail;
 484         uint64_t bsize,dfree,dsize;
 485
 486         /*
 487          * Actually try and commit the space on disk....
 488          */
 489
 490         DEBUG(10,("vfs_allocate_file_space: file %s, len %.0f\n",
 491                   fsp_str_dbg(fsp), (double)len));
 492
 493         if (((SMB_OFF_T)len) < 0) {
 494                 DEBUG(0,("vfs_allocate_file_space: %s negative len "
 495                          "requested.\n", fsp_str_dbg(fsp)));
 496                 errno = EINVAL;
 497                 return -1;
 498         }
 499
 500         ret = SMB_VFS_FSTAT(fsp, &st);
 501         if (ret == -1)
 502                 return ret;
 503
 504         if (len == (uint64_t)st.st_ex_size)
 505                 return 0;
 506
 507         if (len < (uint64_t)st.st_ex_size) {
 508                 /* Shrink - use ftruncate. */
 509
 510                 DEBUG(10,("vfs_allocate_file_space: file %s, shrink. Current "
 511                           "size %.0f\n", fsp_str_dbg(fsp),
 512                           (double)st.st_ex_size));
 513
 514                 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_ALLOC_SHRINK);
 515
 516                 flush_write_cache(fsp, SIZECHANGE_FLUSH);
 517                 if ((ret = SMB_VFS_FTRUNCATE(fsp, (SMB_OFF_T)len)) != -1) {
 518                         set_filelen_write_cache(fsp, len);
 519                 }
 520
 521                 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_ALLOC_SHRINK);
 522
 523                 return ret;
 524         }
 525
 526         /* Grow - we need to test if we have enough space. */
 527
 528         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_ALLOC_GROW);
 529         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_ALLOC_GROW);
 530
 531         if (!lp_strict_allocate(SNUM(fsp->conn)))
 532                 return 0;
 533
 534         len -= st.st_ex_size;
 535         len /= 1024; /* Len is now number of 1k blocks needed. */
 536         space_avail = get_dfree_info(conn, fsp->fsp_name->base_name, false,
 537                                      &bsize, &dfree, &dsize);
 538         if (space_avail == (uint64_t)-1) {
 539                 return -1;
 540         }
 541
 542         DEBUG(10,("vfs_allocate_file_space: file %s, grow. Current size %.0f, "
 543                   "needed blocks = %.0f, space avail = %.0f\n",
 544                   fsp_str_dbg(fsp), (double)st.st_ex_size, (double)len,
 545                   (double)space_avail));
 546
 547         if (len > space_avail) {
 548                 errno = ENOSPC;
 549                 return -1;
 550         }
 551
 552         return 0;
 553 }
 554
 555 /****************************************************************************
 556  A vfs set_filelen call.
 557  set the length of a file from a filedescriptor.
 558  Returns 0 on success, -1 on failure.
 559 ****************************************************************************/
 560
 561 int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
 562 {
 563         int ret;
 564
 565         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_SET_FILE_LEN);
 566
 567         DEBUG(10,("vfs_set_filelen: ftruncate %s to len %.0f\n",
 568                   fsp_str_dbg(fsp), (double)len));
 569         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 570         if ((ret = SMB_VFS_FTRUNCATE(fsp, len)) != -1) {
 571                 set_filelen_write_cache(fsp, len);
 572                 notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
 573                              FILE_NOTIFY_CHANGE_SIZE
 574                              | FILE_NOTIFY_CHANGE_ATTRIBUTES,
 575                              fsp->fsp_name->base_name);
 576         }
 577
 578         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_SET_FILE_LEN);
 579
 580         return ret;
 581 }
 582
 583 /****************************************************************************
 584  A vfs fill sparse call.
 585  Writes zeros from the end of file to len, if len is greater than EOF.
 586  Used only by strict_sync.
 587  Returns 0 on success, -1 on failure.
 588 ****************************************************************************/
 589
 590 #define SPARSE_BUF_WRITE_SIZE (32*1024)
 591
 592 int vfs_fill_sparse(files_struct *fsp, SMB_OFF_T len)
 593 {
 594         int ret;
 595         SMB_STRUCT_STAT st;
 596         SMB_OFF_T offset;
 597         size_t total;
 598         size_t num_to_write;
 599         ssize_t pwrite_ret;
 600
 601         ret = SMB_VFS_FSTAT(fsp, &st);
 602         if (ret == -1) {
 603                 return ret;
 604         }
 605
 606         if (len <= st.st_ex_size) {
 607                 return 0;
 608         }
 609
 610         DEBUG(10,("vfs_fill_sparse: write zeros in file %s from len %.0f to "
 611                   "len %.0f (%.0f bytes)\n", fsp_str_dbg(fsp),
 612                   (double)st.st_ex_size, (double)len,
 613                   (double)(len - st.st_ex_size)));
 614
 615         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_FILL_SPARSE);
 616
 617         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 618
 619         if (!sparse_buf) {
 620                 sparse_buf = SMB_CALLOC_ARRAY(char, SPARSE_BUF_WRITE_SIZE);
 621                 if (!sparse_buf) {
 622                         errno = ENOMEM;
 623                         ret = -1;
 624                         goto out;
 625                 }
 626         }
 627
 628         offset = st.st_ex_size;
 629         num_to_write = len - st.st_ex_size;
 630         total = 0;
 631
 632         while (total < num_to_write) {
 633                 size_t curr_write_size = MIN(SPARSE_BUF_WRITE_SIZE, (num_to_write - total));
 634
 635                 pwrite_ret = SMB_VFS_PWRITE(fsp, sparse_buf, curr_write_size, offset + total);
 636                 if (pwrite_ret == -1) {
 637                         DEBUG(10,("vfs_fill_sparse: SMB_VFS_PWRITE for file "
 638                                   "%s failed with error %s\n",
 639                                   fsp_str_dbg(fsp), strerror(errno)));
 640                         ret = -1;
 641                         goto out;
 642                 }
 643                 if (pwrite_ret == 0) {
 644                         ret = 0;
 645                         goto out;
 646                 }
 647
 648                 total += pwrite_ret;
 649         }
 650
 651         set_filelen_write_cache(fsp, len);
 652
 653         ret = 0;
 654  out:
 655         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_FILL_SPARSE);
 656         return ret;
 657 }
 658
 659 /****************************************************************************
 660  Transfer some data (n bytes) between two file_struct's.
 661 ****************************************************************************/
 662
 663 static ssize_t vfs_read_fn(void *file, void *buf, size_t len)
 664 {
 665         struct files_struct *fsp = (struct files_struct *)file;
 666
 667         return SMB_VFS_READ(fsp, buf, len);
 668 }
 669
 670 static ssize_t vfs_write_fn(void *file, const void *buf, size_t len)
 671 {
 672         struct files_struct *fsp = (struct files_struct *)file;
 673
 674         return SMB_VFS_WRITE(fsp, buf, len);
 675 }
 676
 677 SMB_OFF_T vfs_transfer_file(files_struct *in, files_struct *out, SMB_OFF_T n)
 678 {
 679         return transfer_file_internal((void *)in, (void *)out, n,
 680                                       vfs_read_fn, vfs_write_fn);
 681 }
 682
 683 /*******************************************************************
 684  A vfs_readdir wrapper which just returns the file name.
 685 ********************************************************************/
 686
 687 char *vfs_readdirname(connection_struct *conn, void *p, SMB_STRUCT_STAT *sbuf)
 688 {
 689         SMB_STRUCT_DIRENT *ptr= NULL;
 690         char *dname;
 691
 692         if (!p)
 693                 return(NULL);
 694
 695         ptr = SMB_VFS_READDIR(conn, (DIR *)p, sbuf);
 696         if (!ptr)
 697                 return(NULL);
 698
 699         dname = ptr->d_name;
 700
 701 #ifdef NEXT2
 702         if (telldir(p) < 0)
 703                 return(NULL);
 704 #endif
 705
 706 #ifdef HAVE_BROKEN_READDIR_NAME
 707         /* using /usr/ucb/cc is BAD */
 708         dname = dname - 2;
 709 #endif
 710
 711         return(dname);
 712 }
 713
 714 /*******************************************************************
 715  A wrapper for vfs_chdir().
 716 ********************************************************************/
 717
 718 int vfs_ChDir(connection_struct *conn, const char *path)
 719 {
 720         int res;
 721
 722         if (!LastDir) {
 723                 LastDir = SMB_STRDUP("");
 724         }
 725
 726         if (strcsequal(path,"."))
 727                 return(0);
 728
 729         if (*path == '/' && strcsequal(LastDir,path))
 730                 return(0);
 731
 732         DEBUG(4,("vfs_ChDir to %s\n",path));
 733
 734         res = SMB_VFS_CHDIR(conn,path);
 735         if (!res) {
 736                 SAFE_FREE(LastDir);
 737                 LastDir = SMB_STRDUP(path);
 738         }
 739         return(res);
 740 }
 741
 742 /*******************************************************************
 743  Return the absolute current directory path - given a UNIX pathname.
 744  Note that this path is returned in DOS format, not UNIX
 745  format. Note this can be called with conn == NULL.
 746 ********************************************************************/
 747
 748 char *vfs_GetWd(TALLOC_CTX *ctx, connection_struct *conn)
 749 {
 750         char s[PATH_MAX+1];
 751         char *result = NULL;
 752         DATA_BLOB cache_value;
 753         struct file_id key;
 754         struct smb_filename *smb_fname_dot = NULL;
 755         struct smb_filename *smb_fname_full = NULL;
 756         NTSTATUS status;
 757
 758         *s = 0;
 759
 760         if (!lp_getwd_cache()) {
 761                 goto nocache;
 762         }
 763
 764         status = create_synthetic_smb_fname(ctx, ".", NULL, NULL,
 765                                             &smb_fname_dot);
 766         if (!NT_STATUS_IS_OK(status)) {
 767                 errno = map_errno_from_nt_status(status);
 768                 goto out;
 769         }
 770
 771         if (SMB_VFS_STAT(conn, smb_fname_dot) == -1) {
 772                 /*
 773                  * Known to fail for root: the directory may be NFS-mounted
 774                  * and exported with root_squash (so has no root access).
 775                  */
 776                 DEBUG(1,("vfs_GetWd: couldn't stat \".\" error %s "
 777                          "(NFS problem ?)\n", strerror(errno) ));
 778                 goto nocache;
 779         }
 780
 781         key = vfs_file_id_from_sbuf(conn, &smb_fname_dot->st);
 782
 783         if (!memcache_lookup(smbd_memcache(), GETWD_CACHE,
 784                              data_blob_const(&key, sizeof(key)),
 785                              &cache_value)) {
 786                 goto nocache;
 787         }
 788
 789         SMB_ASSERT((cache_value.length > 0)
 790                    && (cache_value.data[cache_value.length-1] == '\0'));
 791
 792         status = create_synthetic_smb_fname(ctx, (char *)cache_value.data,
 793                                             NULL, NULL, &smb_fname_full);
 794         if (!NT_STATUS_IS_OK(status)) {
 795                 errno = map_errno_from_nt_status(status);
 796                 goto out;
 797         }
 798
 799         if ((SMB_VFS_STAT(conn, smb_fname_full) == 0) &&
 800             (smb_fname_dot->st.st_ex_dev == smb_fname_full->st.st_ex_dev) &&
 801             (smb_fname_dot->st.st_ex_ino == smb_fname_full->st.st_ex_ino) &&
 802             (S_ISDIR(smb_fname_dot->st.st_ex_mode))) {
 803                 /*
 804                  * Ok, we're done
 805                  */
 806                 result = talloc_strdup(ctx, smb_fname_full->base_name);
 807                 if (result == NULL) {
 808                         errno = ENOMEM;
 809                 }
 810                 goto out;
 811         }
 812
 813  nocache:
 814
 815         /*
 816          * We don't have the information to hand so rely on traditional
 817          * methods. The very slow getcwd, which spawns a process on some
 818          * systems, or the not quite so bad getwd.
 819          */
 820
 821         if (!SMB_VFS_GETWD(conn,s)) {
 822                 DEBUG(0, ("vfs_GetWd: SMB_VFS_GETWD call failed: %s\n",
 823                           strerror(errno)));
 824                 goto out;
 825         }
 826
 827         if (lp_getwd_cache() && VALID_STAT(smb_fname_dot->st)) {
 828                 key = vfs_file_id_from_sbuf(conn, &smb_fname_dot->st);
 829
 830                 memcache_add(smbd_memcache(), GETWD_CACHE,
 831                              data_blob_const(&key, sizeof(key)),
 832                              data_blob_const(s, strlen(s)+1));
 833         }
 834
 835         result = talloc_strdup(ctx, s);
 836         if (result == NULL) {
 837                 errno = ENOMEM;
 838         }
 839
 840  out:
 841         TALLOC_FREE(smb_fname_dot);
 842         TALLOC_FREE(smb_fname_full);
 843         return result;
 844 }
 845
 846 /*******************************************************************
 847  Reduce a file name, removing .. elements and checking that
 848  it is below dir in the heirachy. This uses realpath.
 849 ********************************************************************/
 850
 851 NTSTATUS check_reduced_name(connection_struct *conn, const char *fname)
 852 {
 853 #ifdef REALPATH_TAKES_NULL
 854         bool free_resolved_name = True;
 855 #else
 856         char resolved_name_buf[PATH_MAX+1];
 857         bool free_resolved_name = False;
 858 #endif
 859         char *resolved_name = NULL;
 860         char *p = NULL;
 861
 862         DEBUG(3,("reduce_name [%s] [%s]\n", fname, conn->connectpath));
 863
 864 #ifdef REALPATH_TAKES_NULL
 865         resolved_name = SMB_VFS_REALPATH(conn,fname,NULL);
 866 #else
 867         resolved_name = SMB_VFS_REALPATH(conn,fname,resolved_name_buf);
 868 #endif
 869
 870         if (!resolved_name) {
 871                 switch (errno) {
 872                         case ENOTDIR:
 873                                 DEBUG(3,("reduce_name: Component not a directory in getting realpath for %s\n", fname));
 874                                 return map_nt_error_from_unix(errno);
 875                         case ENOENT:
 876                         {
 877                                 TALLOC_CTX *ctx = talloc_tos();
 878                                 char *tmp_fname = NULL;
 879                                 char *last_component = NULL;
 880                                 /* Last component didn't exist. Remove it and try and canonicalise the directory. */
 881
 882                                 tmp_fname = talloc_strdup(ctx, fname);
 883                                 if (!tmp_fname) {
 884                                         return NT_STATUS_NO_MEMORY;
 885                                 }
 886                                 p = strrchr_m(tmp_fname, '/');
 887                                 if (p) {
 888                                         *p++ = '\0';
 889                                         last_component = p;
 890                                 } else {
 891                                         last_component = tmp_fname;
 892                                         tmp_fname = talloc_strdup(ctx,
 893                                                         ".");
 894                                         if (!tmp_fname) {
 895                                                 return NT_STATUS_NO_MEMORY;
 896                                         }
 897                                 }
 898
 899 #ifdef REALPATH_TAKES_NULL
 900                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,NULL);
 901 #else
 902                                 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,resolved_name_buf);
 903 #endif
 904                                 if (!resolved_name) {
 905                                         DEBUG(3,("reduce_name: couldn't get realpath for %s\n", fname));
 906                                         return map_nt_error_from_unix(errno);
 907                                 }
 908                                 tmp_fname = talloc_asprintf(ctx,
 909                                                 "%s/%s",
 910                                                 resolved_name,
 911                                                 last_component);
 912                                 if (!tmp_fname) {
 913                                         return NT_STATUS_NO_MEMORY;
 914                                 }
 915 #ifdef REALPATH_TAKES_NULL
 916                                 SAFE_FREE(resolved_name);
 917                                 resolved_name = SMB_STRDUP(tmp_fname);
 918                                 if (!resolved_name) {
 919                                         DEBUG(0,("reduce_name: malloc fail for %s\n", tmp_fname));
 920                                         return NT_STATUS_NO_MEMORY;
 921                                 }
 922 #else
 923                                 safe_strcpy(resolved_name_buf, tmp_fname, PATH_MAX);
 924                                 resolved_name = resolved_name_buf;
 925 #endif
 926                                 break;
 927                         }
 928                         default:
 929                                 DEBUG(1,("reduce_name: couldn't get realpath for %s\n", fname));
 930                                 return map_nt_error_from_unix(errno);
 931                 }
 932         }
 933
 934         DEBUG(10,("reduce_name realpath [%s] -> [%s]\n", fname, resolved_name));
 935
 936         if (*resolved_name != '/') {
 937                 DEBUG(0,("reduce_name: realpath doesn't return absolute paths !\n"));
 938                 if (free_resolved_name) {
 939                         SAFE_FREE(resolved_name);
 940                 }
 941                 return NT_STATUS_OBJECT_NAME_INVALID;
 942         }
 943
 944         /* Check for widelinks allowed. */
 945         if (!lp_widelinks(SNUM(conn))) {
 946                     const char *conn_rootdir;
 947
 948                     conn_rootdir = SMB_VFS_CONNECTPATH(conn, fname);
 949                     if (conn_rootdir == NULL) {
 950                             DEBUG(2, ("check_reduced_name: Could not get conn_rootdir\n"));
 951                             if (free_resolved_name) {
 952                                     SAFE_FREE(resolved_name);
 953                             }
 954                             return NT_STATUS_ACCESS_DENIED;
 955                     }
 956
 957                     if (strncmp(conn_rootdir, resolved_name,
 958                                 strlen(conn_rootdir)) != 0) {
 959                             DEBUG(2, ("reduce_name: Bad access attempt: %s is "
 960                                       "a symlink outside the share path",
 961                                       fname));
 962                             if (free_resolved_name) {
 963                                     SAFE_FREE(resolved_name);
 964                             }
 965                             return NT_STATUS_ACCESS_DENIED;
 966                     }
 967         }
 968
 969         /* Check if we are allowing users to follow symlinks */
 970         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 971                 University of Geneva */
 972
 973 #ifdef S_ISLNK
 974         if (!lp_symlinks(SNUM(conn))) {
 975                 SMB_STRUCT_STAT statbuf;
 976                 if ( (vfs_lstat_smb_fname(conn,fname,&statbuf) != -1) &&
 977                                 (S_ISLNK(statbuf.st_ex_mode)) ) {
 978                         if (free_resolved_name) {
 979                                 SAFE_FREE(resolved_name);
 980                         }
 981                         DEBUG(3,("reduce_name: denied: file path name %s is a symlink\n",resolved_name));
 982                         return NT_STATUS_ACCESS_DENIED;
 983                 }
 984         }
 985 #endif
 986
 987         DEBUG(3,("reduce_name: %s reduced to %s\n", fname, resolved_name));
 988         if (free_resolved_name) {
 989                 SAFE_FREE(resolved_name);
 990         }
 991         return NT_STATUS_OK;
 992 }