Kernel/vfs/open.c

   1 /*
   2  * Acess2 VFS
   3  * - Open, Close and ChDir
   4  */
   5 #define DEBUG   0
   6 #include <acess.h>
   7 #include <mm_virt.h>
   8 #include "vfs.h"
   9 #include "vfs_int.h"
  10 #include "vfs_ext.h"
  11
  12 // === CONSTANTS ===
  13 #define OPEN_MOUNT_ROOT 1
  14 #define MAX_KERNEL_FILES        128
  15 #define MAX_PATH_SLASHES        256
  16
  17 // === IMPORTS ===
  18 extern tVFS_Node        gVFS_MemRoot;
  19 extern tVFS_Mount       *gVFS_RootMount;
  20
  21 // === GLOBALS ===
  22 tVFS_Handle     *gaUserHandles = (void*)MM_PPD_VFS;
  23 tVFS_Handle     *gaKernelHandles = (void*)MM_KERNEL_VFS;
  24
  25 // === CODE ===
  26 /**
  27  * \fn char *VFS_GetAbsPath(const char *Path)
  28  * \brief Create an absolute path from a relative one
  29  */
  30 char *VFS_GetAbsPath(const char *Path)
  31 {
  32         char    *ret;
  33          int    pathLen = strlen(Path);
  34         char    *pathComps[MAX_PATH_SLASHES];
  35         char    *tmpStr;
  36         int             iPos = 0;
  37         int             iPos2 = 0;
  38         char    *chroot = CFGPTR(CFG_VFS_CHROOT);
  39          int    chrootLen;
  40         char    *cwd = CFGPTR(CFG_VFS_CWD);
  41          int    cwdLen;
  42
  43         ENTER("sPath", Path);
  44
  45         // Memory File
  46         if(Path[0] == '$') {
  47                 ret = malloc(strlen(Path)+1);
  48                 if(!ret) {
  49                         Warning("VFS_GetAbsPath - malloc() returned NULL");
  50                         return NULL;
  51                 }
  52                 strcpy(ret, Path);
  53                 LEAVE('p', ret);
  54                 return ret;
  55         }
  56
  57         // - Fetch ChRoot
  58         if( chroot == NULL ) {
  59                 chroot = "";
  60                 chrootLen = 0;
  61         } else {
  62                 chrootLen = strlen(chroot);
  63         }
  64
  65         // Check if the path is already absolute
  66         if(Path[0] == '/') {
  67                 ret = malloc(pathLen + 1);
  68                 if(!ret) {
  69                         Warning("VFS_GetAbsPath - malloc() returned NULL");
  70                         return NULL;
  71                 }
  72                 strcpy(ret, Path);
  73         } else {
  74                 if(cwd == NULL) {
  75                         cwd = "/";
  76                         cwdLen = 1;
  77                 }
  78                 else {
  79                         cwdLen = strlen(cwd);
  80                 }
  81                 // Prepend the current directory
  82                 ret = malloc( cwdLen + 1 + pathLen + 1 );
  83                 strcpy(ret, cwd);
  84                 ret[cwdLen] = '/';
  85                 strcpy(&ret[cwdLen+1], Path);
  86                 //Log("ret = '%s'\n", ret);
  87         }
  88
  89         // Parse Path
  90         pathComps[iPos++] = tmpStr = ret+1;
  91         while(*tmpStr)
  92         {
  93                 if(*tmpStr++ == '/')
  94                 {
  95                         pathComps[iPos++] = tmpStr;
  96                         if(iPos == MAX_PATH_SLASHES) {
  97                                 LOG("Path '%s' has too many elements", Path);
  98                                 free(ret);
  99                                 LEAVE('n');
 100                                 return NULL;
 101                         }
 102                 }
 103         }
 104         pathComps[iPos] = NULL;
 105
 106         // Cleanup
 107         iPos2 = iPos = 0;
 108         while(pathComps[iPos])
 109         {
 110                 tmpStr = pathComps[iPos];
 111                 // Always Increment iPos
 112                 iPos++;
 113                 // ..
 114                 if(tmpStr[0] == '.' && tmpStr[1] == '.' && (tmpStr[2] == '/' || tmpStr[2] == '\0') )
 115                 {
 116                         if(iPos2 != 0)
 117                                 iPos2 --;
 118                         continue;
 119                 }
 120                 // .
 121                 if(tmpStr[0] == '.' && (tmpStr[1] == '/' || tmpStr[1] == '\0') )
 122                 {
 123                         continue;
 124                 }
 125                 // Empty
 126                 if(tmpStr[0] == '/' || tmpStr[0] == '\0')
 127                 {
 128                         continue;
 129                 }
 130
 131                 // Set New Position
 132                 pathComps[iPos2] = tmpStr;
 133                 iPos2++;
 134         }
 135         pathComps[iPos2] = NULL;
 136
 137         // Build New Path
 138         iPos2 = 1;      iPos = 0;
 139         ret[0] = '/';
 140         while(pathComps[iPos])
 141         {
 142                 tmpStr = pathComps[iPos];
 143                 while(*tmpStr && *tmpStr != '/')
 144                 {
 145                         ret[iPos2++] = *tmpStr;
 146                         tmpStr++;
 147                 }
 148                 ret[iPos2++] = '/';
 149                 iPos++;
 150         }
 151         if(iPos2 > 1)
 152                 ret[iPos2-1] = 0;
 153         else
 154                 ret[iPos2] = 0;
 155
 156
 157         // Prepend the chroot
 158         tmpStr = malloc(chrootLen + strlen(ret) + 1);
 159         strcpy( tmpStr, chroot );
 160         strcpy( tmpStr+chrootLen, ret );
 161         free(ret);
 162         ret = tmpStr;
 163
 164         LEAVE('s', ret);
 165         //Log("VFS_GetAbsPath: RETURN '%s'", ret);
 166         return ret;
 167 }
 168
 169 /**
 170  * \fn char *VFS_ParsePath(const char *Path, char **TruePath)
 171  * \brief Parses a path, resolving sysmlinks and applying permissions
 172  */
 173 tVFS_Node *VFS_ParsePath(const char *Path, char **TruePath)
 174 {
 175         tVFS_Mount      *mnt;
 176         tVFS_Mount      *longestMount = gVFS_RootMount; // Root is first
 177          int    cmp, retLength = 0;
 178          int    ofs, nextSlash;
 179         tVFS_Node       *curNode, *tmpNode;
 180         char    *tmp;
 181
 182         ENTER("sPath pTruePath", Path, TruePath);
 183
 184         // Memory File
 185         if(Path[0] == '$') {
 186                 if(TruePath) {
 187                         *TruePath = malloc(strlen(Path)+1);
 188                         strcpy(*TruePath, Path);
 189                 }
 190                 curNode = gVFS_MemRoot.FindDir(&gVFS_MemRoot, Path);
 191                 LEAVE('p', curNode);
 192                 return curNode;
 193         }
 194
 195         // For root we always fast return
 196         if(Path[0] == '/' && Path[1] == '\0') {
 197                 if(TruePath) {
 198                         *TruePath = malloc( gVFS_RootMount->MountPointLen+1 );
 199                         strcpy(*TruePath, gVFS_RootMount->MountPoint);
 200                 }
 201                 LEAVE('p', gVFS_RootMount->RootNode);
 202                 return gVFS_RootMount->RootNode;
 203         }
 204
 205         // Check if there is an`ything mounted
 206         if(!gVFS_Mounts) {
 207                 Warning("WTF! There's nothing mounted?");
 208                 return NULL;
 209         }
 210
 211         // Find Mountpoint
 212         for(mnt = gVFS_Mounts;
 213                 mnt;
 214                 mnt = mnt->Next)
 215         {
 216                 // Quick Check
 217                 if( Path[mnt->MountPointLen] != '/' && Path[mnt->MountPointLen] != '\0')
 218                         continue;
 219                 // Length Check - If the length is smaller than the longest match sofar
 220                 if(mnt->MountPointLen < longestMount->MountPointLen)    continue;
 221                 // String Compare
 222                 cmp = strcmp(Path, mnt->MountPoint);
 223
 224                 #if OPEN_MOUNT_ROOT
 225                 // Fast Break - Request Mount Root
 226                 if(cmp == 0) {
 227                         if(TruePath) {
 228                                 *TruePath = malloc( mnt->MountPointLen+1 );
 229                                 strcpy(*TruePath, mnt->MountPoint);
 230                         }
 231                         LEAVE('p', mnt->RootNode);
 232                         return mnt->RootNode;
 233                 }
 234                 #endif
 235                 // Not a match, continue
 236                 if(cmp != '/')  continue;
 237                 longestMount = mnt;
 238         }
 239
 240         // Save to shorter variable
 241         mnt = longestMount;
 242
 243         LOG("mnt = {MountPoint:\"%s\"}", mnt->MountPoint);
 244
 245         // Initialise String
 246         if(TruePath)
 247         {
 248                 *TruePath = malloc( mnt->MountPointLen+1 );
 249                 strcpy(*TruePath, mnt->MountPoint);
 250                 retLength = mnt->MountPointLen;
 251         }
 252
 253         curNode = mnt->RootNode;
 254         curNode->ReferenceCount ++;
 255         // Parse Path
 256         ofs = mnt->MountPointLen+1;
 257         for(; (nextSlash = strpos(&Path[ofs], '/')) != -1; ofs += nextSlash + 1)
 258         {
 259                 char    pathEle[nextSlash+1];
 260
 261                 // Empty String
 262                 if(nextSlash == 0)      continue;
 263
 264                 memcpy(pathEle, &Path[ofs], nextSlash);
 265                 pathEle[nextSlash] = 0;
 266
 267                 // Check permissions on root of filesystem
 268                 if( !VFS_CheckACL(curNode, VFS_PERM_EXECUTE) ) {
 269                         if(curNode->Close)      curNode->Close( curNode );
 270                         if(TruePath) {
 271                                 free(*TruePath);
 272                                 *TruePath = NULL;
 273                         }
 274                         //Log("Permissions fail on '%s'", Path);
 275                         LEAVE('n');
 276                         return NULL;
 277                 }
 278
 279                 // Check if the node has a FindDir method
 280                 if( !curNode->FindDir )
 281                 {
 282                         if(curNode->Close)      curNode->Close(curNode);
 283                         if(TruePath) {
 284                                 free(*TruePath);
 285                                 *TruePath = NULL;
 286                         }
 287                         //Log("FindDir fail on '%s'", Path);
 288                         LEAVE('n');
 289                         return NULL;
 290                 }
 291                 LOG("FindDir{=%p}(%p, '%s')", curNode->FindDir, curNode, pathEle);
 292                 // Get Child Node
 293                 tmpNode = curNode->FindDir(curNode, pathEle);
 294                 LOG("tmpNode = %p", tmpNode);
 295                 if(curNode->Close) {
 296                         //LOG2("curNode->Close = %p", curNode->Close);
 297                         curNode->Close(curNode);
 298                 }
 299                 curNode = tmpNode;
 300
 301                 // Error Check
 302                 if(!curNode) {
 303                         LOG("Node '%s' not found in dir '%s'", pathEle, Path);
 304                         if(TruePath) {
 305                                 free(*TruePath);
 306                                 *TruePath = NULL;
 307                         }
 308                         //Log("Child fail on '%s' ('%s)", Path, pathEle);
 309                         LEAVE('n');
 310                         return NULL;
 311                 }
 312
 313                 // Handle Symbolic Links
 314                 if(curNode->Flags & VFS_FFLAG_SYMLINK) {
 315                         if(TruePath) {
 316                                 free(*TruePath);
 317                                 *TruePath = NULL;
 318                         }
 319                         if(!curNode->Read) {
 320                                 Warning("VFS_ParsePath - Read of node %p is NULL (%s)",
 321                                         curNode, Path);
 322                                 if(curNode->Close)      curNode->Close(curNode);
 323                                 // No need to free *TruePath, see above
 324                                 LEAVE('n');
 325                                 return NULL;
 326                         }
 327
 328                         tmp = malloc( curNode->Size + 1 );
 329                         if(!tmp) {
 330                                 Log_Warning("VFS", "VFS_ParsePath - Malloc failure");
 331                                 // No need to free *TruePath, see above
 332                                 LEAVE('n');
 333                                 return NULL;
 334                         }
 335                         curNode->Read( curNode, 0, curNode->Size, tmp );
 336                         tmp[ curNode->Size ] = '\0';
 337
 338                         // Parse Symlink Path
 339                         curNode = VFS_ParsePath(tmp, TruePath);
 340                         if(TruePath)
 341                                 LOG("VFS", "*TruePath='%s'", *TruePath);
 342
 343                         // Error Check
 344                         if(!curNode) {
 345                                 Log_Debug("VFS", "Symlink fail '%s'", tmp);
 346                                 free(tmp);      // Free temp string
 347                                 if(TruePath)    free(TruePath);
 348                                 LEAVE('n');
 349                                 return NULL;
 350                         }
 351
 352                         // Free temp link
 353                         free(tmp);
 354
 355                         // Set Path Variable
 356                         if(TruePath) {
 357                                 retLength = strlen(*TruePath);
 358                         }
 359
 360                         continue;
 361                 }
 362
 363                 // Handle Non-Directories
 364                 if( !(curNode->Flags & VFS_FFLAG_DIRECTORY) )
 365                 {
 366                         Warning("VFS_ParsePath - File in directory context");
 367                         if(TruePath)    free(*TruePath);
 368                         LEAVE('n');
 369                         return NULL;
 370                 }
 371
 372                 // Check if path needs extending
 373                 if(!TruePath)   continue;
 374
 375                 // Increase buffer space
 376                 tmp = realloc( *TruePath, retLength + strlen(pathEle) + 1 + 1 );
 377                 // Check if allocation succeeded
 378                 if(!tmp) {
 379                         Warning("VFS_ParsePath -  Unable to reallocate true path buffer");
 380                         free(*TruePath);
 381                         *TruePath = NULL;
 382                         if(curNode->Close)      curNode->Close(curNode);
 383                         LEAVE('n');
 384                         return NULL;
 385                 }
 386                 *TruePath = tmp;
 387                 // Append to path
 388                 (*TruePath)[retLength] = '/';
 389                 strcpy(*TruePath+retLength+1, pathEle);
 390
 391                 LOG("*TruePath = '%s'", *TruePath);
 392
 393                 // - Extend Path
 394                 retLength += nextSlash + 1;
 395         }
 396
 397         if( !curNode->FindDir ) {
 398                 if(curNode->Close)      curNode->Close(curNode);
 399                 if(TruePath) {
 400                         free(*TruePath);
 401                         *TruePath = NULL;
 402                 }
 403                 Log("FindDir fail on '%s'", Path);
 404                 LEAVE('n');
 405                 return NULL;
 406         }
 407
 408         // Get last node
 409         LOG("VFS_ParsePath: FindDir(%p, '%s')", curNode, &Path[ofs]);
 410         tmpNode = curNode->FindDir(curNode, &Path[ofs]);
 411         LOG("tmpNode = %p", tmpNode);
 412         if(curNode->Close)      curNode->Close(curNode);
 413         // Check if file was found
 414         if(!tmpNode) {
 415                 LOG("Node '%s' not found in dir '%s'", &Path[ofs], Path);
 416                 //Log("Child fail '%s' ('%s')", Path, &Path[ofs]);
 417                 if(TruePath)    free(*TruePath);
 418                 if(curNode->Close)      curNode->Close(curNode);
 419                 LEAVE('n');
 420                 return NULL;
 421         }
 422
 423         if(TruePath)
 424         {
 425                 // Increase buffer space
 426                 tmp = realloc(*TruePath, retLength + strlen(&Path[ofs]) + 1 + 1);
 427                 // Check if allocation succeeded
 428                 if(!tmp) {
 429                         Warning("VFS_ParsePath -  Unable to reallocate true path buffer");
 430                         free(*TruePath);
 431                         if(tmpNode->Close)      tmpNode->Close(curNode);
 432                         LEAVE('n');
 433                         return NULL;
 434                 }
 435                 *TruePath = tmp;
 436                 // Append to path
 437                 (*TruePath)[retLength] = '/';
 438                 strcpy(*TruePath + retLength + 1, &Path[ofs]);
 439                 // - Extend Path
 440                 //retLength += strlen(tmpNode->Name) + 1;
 441         }
 442
 443         LEAVE('p', tmpNode);
 444         return tmpNode;
 445 }
 446
 447 /**
 448  * \fn int VFS_Open(char *Path, Uint Mode)
 449  * \brief Open a file
 450  */
 451 int VFS_Open(char *Path, Uint Mode)
 452 {
 453         tVFS_Node       *node;
 454         char    *absPath;
 455          int    i;
 456
 457         ENTER("sPath xMode", Path, Mode);
 458
 459         // Get absolute path
 460         absPath = VFS_GetAbsPath(Path);
 461         if(absPath == NULL) {
 462                 Log_Warning("VFS", "VFS_Open: Path expansion failed '%s'", Path);
 463                 return -1;
 464         }
 465         LOG("absPath = \"%s\"", absPath);
 466         // Parse path and get mount point
 467         node = VFS_ParsePath(absPath, NULL);
 468         // Free generated path
 469         free(absPath);
 470
 471         if(!node) {
 472                 LOG("Cannot find node");
 473                 LEAVE('i', -1);
 474                 return -1;
 475         }
 476
 477         // Check for symlinks
 478         if( !(Mode & VFS_OPENFLAG_NOLINK) && (node->Flags & VFS_FFLAG_SYMLINK) )
 479         {
 480                 if( !node->Read ) {
 481                         Warning("No read method on symlink");
 482                         LEAVE('i', -1);
 483                         return -1;
 484                 }
 485                 absPath = malloc(node->Size+1); // Allocate Buffer
 486                 node->Read( node, 0, node->Size, absPath );     // Read Path
 487
 488                 absPath[ node->Size ] = '\0';   // End String
 489                 if(node->Close) node->Close( node );    // Close old node
 490                 node = VFS_ParsePath(absPath, NULL);    // Get new node
 491                 free( absPath );        // Free allocated path
 492         }
 493
 494         if(!node) {
 495                 LOG("Cannot find node");
 496                 LEAVE('i', -1);
 497                 return -1;
 498         }
 499
 500         i = 0;
 501         i |= (Mode & VFS_OPENFLAG_EXEC) ? VFS_PERM_EXECUTE : 0;
 502         i |= (Mode & VFS_OPENFLAG_READ) ? VFS_PERM_READ : 0;
 503         i |= (Mode & VFS_OPENFLAG_WRITE) ? VFS_PERM_WRITE : 0;
 504
 505         LOG("i = 0b%b", i);
 506
 507         // Permissions Check
 508         if( !VFS_CheckACL(node, i) ) {
 509                 if(node->Close) node->Close( node );
 510                 Log("VFS_Open: Permissions Failed");
 511                 LEAVE('i', -1);
 512                 return -1;
 513         }
 514
 515         // Check for a user open
 516         if(Mode & VFS_OPENFLAG_USER)
 517         {
 518                 // Allocate Buffer
 519                 if( MM_GetPhysAddr( (Uint)gaUserHandles ) == 0 )
 520                 {
 521                         Uint    addr, size;
 522                         size = CFGINT(CFG_VFS_MAXFILES) * sizeof(tVFS_Handle);
 523                         for(addr = 0; addr < size; addr += 0x1000)
 524                                 MM_Allocate( (Uint)gaUserHandles + addr );
 525                         memset( gaUserHandles, 0, size );
 526                 }
 527                 // Get a handle
 528                 for(i=0;i<CFGINT(CFG_VFS_MAXFILES);i++)
 529                 {
 530                         if(gaUserHandles[i].Node)       continue;
 531                         gaUserHandles[i].Node = node;
 532                         gaUserHandles[i].Position = 0;
 533                         gaUserHandles[i].Mode = Mode;
 534                         LEAVE('i', i);
 535                         return i;
 536                 }
 537         }
 538         else
 539         {
 540                 // Allocate space if not already
 541                 if( MM_GetPhysAddr( (Uint)gaKernelHandles ) == 0 )
 542                 {
 543                         Uint    addr, size;
 544                         size = MAX_KERNEL_FILES * sizeof(tVFS_Handle);
 545                         for(addr = 0; addr < size; addr += 0x1000)
 546                                 MM_Allocate( (Uint)gaKernelHandles + addr );
 547                         memset( gaKernelHandles, 0, size );
 548                 }
 549                 // Get a handle
 550                 for(i=0;i<MAX_KERNEL_FILES;i++)
 551                 {
 552                         if(gaKernelHandles[i].Node)     continue;
 553                         gaKernelHandles[i].Node = node;
 554                         gaKernelHandles[i].Position = 0;
 555                         gaKernelHandles[i].Mode = Mode;
 556                         LEAVE('x', i|VFS_KERNEL_FLAG);
 557                         return i|VFS_KERNEL_FLAG;
 558                 }
 559         }
 560
 561         Log("VFS_Open: Out of handles");
 562         LEAVE('i', -1);
 563         return -1;
 564 }
 565
 566
 567 /**
 568  * \brief Open a file from an open directory
 569  */
 570 int VFS_OpenChild(Uint *Errno, int FD, char *Name, Uint Mode)
 571 {
 572         tVFS_Handle     *h;
 573         tVFS_Node       *node;
 574          int    i;
 575
 576         // Get handle
 577         h = VFS_GetHandle(FD);
 578         if(h == NULL) {
 579                 Log_Warning("VFS", "VFS_OpenChild - Invalid file handle 0x%x", FD);
 580                 if(Errno)       *Errno = EINVAL;
 581                 LEAVE('i', -1);
 582                 return -1;
 583         }
 584
 585         // Check for directory
 586         if( !(h->Node->Flags & VFS_FFLAG_DIRECTORY) ) {
 587                 Log_Warning("VFS", "VFS_OpenChild - Passed handle is not a directory", FD);
 588                 if(Errno)       *Errno = ENOTDIR;
 589                 LEAVE('i', -1);
 590                 return -1;
 591         }
 592
 593         // Find Child
 594         node = h->Node->FindDir(h->Node, Name);
 595         if(!node) {
 596                 if(Errno)       *Errno = ENOENT;
 597                 LEAVE('i', -1);
 598                 return -1;
 599         }
 600
 601         i = 0;
 602         i |= (Mode & VFS_OPENFLAG_EXEC) ? VFS_PERM_EXECUTE : 0;
 603         i |= (Mode & VFS_OPENFLAG_READ) ? VFS_PERM_READ : 0;
 604         i |= (Mode & VFS_OPENFLAG_WRITE) ? VFS_PERM_WRITE : 0;
 605
 606         // Permissions Check
 607         if( !VFS_CheckACL(node, i) ) {
 608                 if(node->Close) node->Close( node );
 609                 Log_Notice("VFS", "VFS_OpenChild - Permissions Failed");
 610                 if(Errno)       *Errno = EACCES;
 611                 LEAVE('i', -1);
 612                 return -1;
 613         }
 614
 615         // Check for a user open
 616         if(Mode & VFS_OPENFLAG_USER)
 617         {
 618                 // Allocate Buffer
 619                 if( MM_GetPhysAddr( (Uint)gaUserHandles ) == 0 )
 620                 {
 621                         Uint    addr, size;
 622                         size = CFGINT(CFG_VFS_MAXFILES) * sizeof(tVFS_Handle);
 623                         for(addr = 0; addr < size; addr += 0x1000)
 624                                 MM_Allocate( (Uint)gaUserHandles + addr );
 625                         memset( gaUserHandles, 0, size );
 626                 }
 627                 // Get a handle
 628                 for(i=0;i<CFGINT(CFG_VFS_MAXFILES);i++)
 629                 {
 630                         if(gaUserHandles[i].Node)       continue;
 631                         gaUserHandles[i].Node = node;
 632                         gaUserHandles[i].Position = 0;
 633                         gaUserHandles[i].Mode = Mode;
 634                         LEAVE('i', i);
 635                         return i;
 636                 }
 637         }
 638         else
 639         {
 640                 // Allocate space if not already
 641                 if( MM_GetPhysAddr( (Uint)gaKernelHandles ) == 0 )
 642                 {
 643                         Uint    addr, size;
 644                         size = MAX_KERNEL_FILES * sizeof(tVFS_Handle);
 645                         for(addr = 0; addr < size; addr += 0x1000)
 646                                 MM_Allocate( (Uint)gaKernelHandles + addr );
 647                         memset( gaKernelHandles, 0, size );
 648                 }
 649                 // Get a handle
 650                 for(i=0;i<MAX_KERNEL_FILES;i++)
 651                 {
 652                         if(gaKernelHandles[i].Node)     continue;
 653                         gaKernelHandles[i].Node = node;
 654                         gaKernelHandles[i].Position = 0;
 655                         gaKernelHandles[i].Mode = Mode;
 656                         LEAVE('x', i|VFS_KERNEL_FLAG);
 657                         return i|VFS_KERNEL_FLAG;
 658                 }
 659         }
 660
 661         Log_Error("VFS", "VFS_OpenChild - Out of handles");
 662         if(Errno)       *Errno = ENFILE;
 663         LEAVE('i', -1);
 664         return -1;
 665 }
 666
 667 /**
 668  * \fn void VFS_Close(int FD)
 669  * \brief Closes an open file handle
 670  */
 671 void VFS_Close(int FD)
 672 {
 673         tVFS_Handle     *h;
 674
 675         // Get handle
 676         h = VFS_GetHandle(FD);
 677         if(h == NULL) {
 678                 Log_Warning("VFS", "Invalid file handle passed to VFS_Close, 0x%x\n", FD);
 679                 return;
 680         }
 681
 682         #if VALIDATE_VFS_FUNCTIPONS
 683         if(h->Node->Close && !MM_GetPhysAddr(h->Node->Close)) {
 684                 Log_Warning("VFS", "Node %p's ->Close method is invalid (%p)",
 685                         h->Node, h->Node->Close);
 686                 return ;
 687         }
 688         #endif
 689
 690         if(h->Node->Close)
 691                 h->Node->Close( h->Node );
 692
 693         h->Node = NULL;
 694 }
 695
 696 /**
 697  * \brief Change current working directory
 698  */
 699 int VFS_ChDir(char *Dest)
 700 {
 701         char    *buf;
 702          int    fd;
 703         tVFS_Handle     *h;
 704
 705         // Create Absolute
 706         buf = VFS_GetAbsPath(Dest);
 707         if(buf == NULL) {
 708                 Log("VFS_ChDir: Path expansion failed");
 709                 return -1;
 710         }
 711
 712         // Check if path exists
 713         fd = VFS_Open(buf, VFS_OPENFLAG_EXEC);
 714         if(fd == -1) {
 715                 Log("VFS_ChDir: Path is invalid");
 716                 return -1;
 717         }
 718
 719         // Get node so we can check for directory
 720         h = VFS_GetHandle(fd);
 721         if( !(h->Node->Flags & VFS_FFLAG_DIRECTORY) ) {
 722                 Log("VFS_ChDir: Path is not a directory");
 723                 VFS_Close(fd);
 724                 return -1;
 725         }
 726
 727         // Close file
 728         VFS_Close(fd);
 729
 730         // Free old working directory
 731         if( CFGPTR(CFG_VFS_CWD) )
 732                 free( CFGPTR(CFG_VFS_CWD) );
 733         // Set new
 734         CFGPTR(CFG_VFS_CWD) = buf;
 735
 736         Log("Updated CWD to '%s'", buf);
 737
 738         return 1;
 739 }
 740
 741 /**
 742  * \fn int VFS_ChRoot(char *New)
 743  * \brief Change current root directory
 744  */
 745 int VFS_ChRoot(char *New)
 746 {
 747         char    *buf;
 748          int    fd;
 749         tVFS_Handle     *h;
 750
 751         if(New[0] == '/' && New[1] == '\0')
 752                 return 1;       // What a useless thing to ask!
 753
 754         // Create Absolute
 755         buf = VFS_GetAbsPath(New);
 756         if(buf == NULL) {
 757                 LOG("Path expansion failed");
 758                 return -1;
 759         }
 760
 761         // Check if path exists
 762         fd = VFS_Open(buf, VFS_OPENFLAG_EXEC);
 763         if(fd == -1) {
 764                 LOG("Path is invalid");
 765                 return -1;
 766         }
 767
 768         // Get node so we can check for directory
 769         h = VFS_GetHandle(fd);
 770         if( !(h->Node->Flags & VFS_FFLAG_DIRECTORY) ) {
 771                 LOG("Path is not a directory");
 772                 VFS_Close(fd);
 773                 return -1;
 774         }
 775
 776         // Close file
 777         VFS_Close(fd);
 778
 779         // Free old working directory
 780         if( CFGPTR(CFG_VFS_CHROOT) )
 781                 free( CFGPTR(CFG_VFS_CHROOT) );
 782         // Set new
 783         CFGPTR(CFG_VFS_CHROOT) = buf;
 784
 785         LOG("Updated Root to '%s'", buf);
 786
 787         return 1;
 788 }
 789
 790 /**
 791  * \fn tVFS_Handle *VFS_GetHandle(int FD)
 792  * \brief Gets a pointer to the handle information structure
 793  */
 794 tVFS_Handle *VFS_GetHandle(int FD)
 795 {
 796         tVFS_Handle     *h;
 797
 798         //Log_Debug("VFS", "VFS_GetHandle: (FD=0x%x)", FD);
 799
 800         if(FD < 0)      return NULL;
 801
 802         if(FD & VFS_KERNEL_FLAG) {
 803                 FD &= (VFS_KERNEL_FLAG - 1);
 804                 if(FD >= MAX_KERNEL_FILES)      return NULL;
 805                 h = &gaKernelHandles[ FD ];
 806         } else {
 807                 if(FD >= CFGINT(CFG_VFS_MAXFILES))      return NULL;
 808                 h = &gaUserHandles[ FD ];
 809         }
 810
 811         if(h->Node == NULL)     return NULL;
 812         //Log_Debug("VFS", "VFS_GetHandle: RETURN %p", h);
 813         return h;
 814 }
 815
 816 // === EXPORTS ===
 817 EXPORT(VFS_Open);
 818 EXPORT(VFS_Close);