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