1 /** @file 2 Device Abstraction: Path manipulation utilities. 3 4 Copyright (c) 2011, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials are licensed and made available under 6 the terms and conditions of the BSD License that accompanies this distribution. 7 The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license.php. 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 **/ 13 #include <Library/BaseLib.h> 14 15 #include <LibConfig.h> 16 17 #include <errno.h> 18 #include <stdlib.h> 19 #include <wchar.h> 20 #include <wctype.h> 21 #include <kfile.h> 22 #include <Device/Device.h> 23 #include <MainData.h> 24 25 /** Identify the type of path pointed to by Path. 26 27 Paths are classified based upon their initial character sequences. 28 ^\\ Absolute Path 29 ^\. Relative Path 30 ^[^:\\]: Mapping Path 31 .* Relative Path 32 33 Mapping paths are broken into two parts at the ':'. The part to the left of the ':' 34 is the Map Name, pointed to by Path, and the part to the right of the ':' is pointed 35 to by NewPath. 36 37 If Path was not a Mapping Path, then NewPath is set to Path. 38 39 @param[in] Path Pointer to the path to be classified. 40 @param[out] NewPath Pointer to the path portion of a mapping path. 41 @param[out] Length Length of the Map Name portion of the path. 42 43 @retval PathAbsolute Path is an absolute path. NewPath points to the first '\'. 44 @retval PathRelative Path is a relative path. NewPath = Path. 45 @retval PathMapping Path is a mapping path. NewPath points to the character following ':'. 46 @retval PathError Path is NULL. 47 **/ 48 PATH_CLASS 49 EFIAPI 50 ClassifyPath( 51 IN wchar_t * Path, 52 OUT wchar_t ** NewPath, 53 OUT int * const Length 54 ) 55 { 56 size_t MapLen; 57 58 if(Path == NULL) { 59 return PathError; // Bad parameter 60 } 61 if(NewPath != NULL) { 62 *NewPath = Path; // Setup default condition 63 } 64 if((*Path == L'\\') || (*Path == L'\0')) { 65 return PathAbsolute; 66 } 67 if(*Path == L'.') { 68 return PathRelative; 69 } 70 /* The easy stuff has been done, now see if this is a mapping path. 71 See if there is a ':' in Path that isn't the first character and is before 72 any '\\' characters. 73 */ 74 MapLen = wcscspn(Path, L"\\:"); 75 if(Length != NULL) { 76 *Length = (int)MapLen; 77 } 78 /* MapLen == 0 means that the first character is a ':' 79 == PathLen means that there are no '\\' or ':' 80 Otherwise, Path[MapLen] == ':' for a mapping path 81 or '\\' for a relative path. 82 */ 83 if(MapLen == 0) { 84 return PathError; 85 } 86 if(Path[MapLen] == L':') { 87 if(NewPath != NULL) { 88 *NewPath = &Path[MapLen + 1]; // Point to character after then ':'. Might be '\0'. 89 } 90 return PathMapping; 91 } 92 return PathRelative; 93 } 94 95 /* Normalize a narrow-character path and produce a wide-character path 96 that has forward slashes replaced with backslashes. 97 Backslashes are directory separators in UEFI File Paths. 98 99 It is the caller's responsibility to eventually free() the returned buffer. 100 101 @param[in] path A pointer to the narrow-character path to be normalized. 102 103 @return A pointer to a buffer containing the normalized, wide-character, path. 104 */ 105 wchar_t * 106 NormalizePath( const char *path) 107 { 108 wchar_t *temp; 109 wchar_t *OldPath; 110 wchar_t *NewPath; 111 size_t Length; 112 113 OldPath = AsciiStrToUnicodeStr(path, gMD->UString); 114 Length = wcslen(OldPath) + 1; 115 116 NewPath = calloc(Length, sizeof(wchar_t)); 117 if(NewPath != NULL) { 118 temp = NewPath; 119 for( ; *OldPath; ++OldPath) { 120 if(*OldPath == L'/') { 121 *temp = L'\\'; 122 } 123 else { 124 *temp = *OldPath; 125 } 126 ++temp; 127 } 128 } 129 else { 130 errno = ENOMEM; 131 EFIerrno = RETURN_OUT_OF_RESOURCES; 132 } 133 return NewPath; 134 } 135 136 /** Process a wide character string representing a Mapping Path and extract the instance number. 137 138 The instance number is the sequence of decimal digits immediately to the left 139 of the ":" in the Map Name portion of a Mapping Path. 140 141 This function is called with a pointer to beginning of the Map Name. 142 Thus Path[Length] must be a ':' and Path[Length - 1] must be a decimal digit. 143 If either of these are not true, an instance value of 0 is returned. 144 145 If Path is NULL, an instance value of 0 is returned. 146 147 @param[in] Path Points to the beginning of a Mapping Path 148 @param[in] Length Number of valid characters to the left of the ':' 149 150 @return Returns either 0 or the value of the contiguous digits to the left of the ':'. 151 **/ 152 int 153 EFIAPI 154 PathInstance( 155 const wchar_t *Path, 156 int Length 157 ) 158 { 159 wchar_t *temp; 160 int instance = 0; 161 162 if((Path != NULL) && (Path[Length] == L':') && (Length > 0)) { 163 for(temp = __UNCONST(&Path[Length - 1]); Length > 0; --Length) { 164 if(!iswdigit(*temp)) { 165 break; 166 } 167 --temp; 168 } 169 instance = (int)wcstol(temp+1, NULL, 10); 170 } 171 return instance; 172 } 173 174 /** Transform a relative path into an absolute path. 175 176 If Path is NULL, return NULL. 177 Otherwise, pre-pend the CWD to Path then process the resulting path to: 178 - Replace "/./" with "/" 179 - Replace "/<dirname>/../" with "/" 180 - Do not allow one to back up past the root, "/" 181 182 Also sets the Current Working Device to the Root Device. 183 184 Path must be a previously allocated buffer. PathAdjust will 185 allocate a new buffer to hold the results of the transformation 186 and free Path. A pointer to the newly allocated buffer is returned. 187 188 @param[in] Path A pointer to the path to be transformed. This buffer 189 will always be freed. 190 191 @return A pointer to a buffer containing the transformed path. 192 **/ 193 wchar_t * 194 EFIAPI 195 PathAdjust( 196 wchar_t *Path 197 ) 198 { 199 wchar_t *NewPath; 200 201 NewPath = calloc(PATH_MAX, sizeof(wchar_t)); 202 if(NewPath != NULL) { 203 wmemcpy(NewPath, Path, PATH_MAX); 204 } 205 else { 206 errno = ENOMEM; 207 } 208 free(Path); 209 return NewPath; 210 } 211 212 /** Replace the leading portion of Path with any aliases. 213 214 Aliases are read from /etc/fstab. If there is an associated device, the 215 Current Working Device is set to that device. 216 217 Path must be a previously allocated buffer. PathAlias will 218 allocate a new buffer to hold the results of the transformation 219 then free Path. A pointer to the newly allocated buffer is returned. 220 221 @param[in] Path A pointer to the original, unaliased, path. This 222 buffer is always freed. 223 @param[out] Node Filled in with a pointer to the Device Node describing 224 the device abstraction associated with this path. 225 226 @return A pointer to a buffer containing the aliased path. 227 **/ 228 wchar_t * 229 EFIAPI 230 PathAlias( 231 wchar_t *Path, 232 DeviceNode **Node 233 ) 234 { 235 wchar_t *NewPath; 236 237 NewPath = calloc(PATH_MAX, sizeof(wchar_t)); 238 if(NewPath != NULL) { 239 wmemcpy(NewPath, Path, PATH_MAX); 240 } 241 else { 242 errno = ENOMEM; 243 } 244 free(Path); 245 *Node = NULL; 246 return NewPath; 247 } 248 249 /** Parse a path producing the target device, device instance, and file path. 250 251 It is the caller's responsibility to free() FullPath and MapPath when they 252 are no longer needed. 253 254 @param[in] path 255 @param[out] FullPath 256 @param[out] DevNode 257 @param[out] Which 258 @param[out] MapPath OPTIONAL. If not NULL, it points to the place to save a pointer 259 to the extracted map name. If the path didn't have a map name, 260 then *MapPath is set to NULL. 261 262 @retval RETURN_SUCCESS The path was parsed successfully. 263 @retval RETURN_NOT_FOUND The path does not map to a valid device. 264 @retval RETURN_OUT_OF_RESOURCES Insufficient memory to calloc a MapName buffer. 265 The errno variable is set to ENOMEM. 266 @retval RETURN_INVALID_PARAMETER The path parameter is not valid. 267 The errno variable is set to EINVAL. 268 **/ 269 RETURN_STATUS 270 EFIAPI 271 ParsePath( 272 IN const char *path, 273 OUT wchar_t **FullPath, 274 OUT DeviceNode **DevNode, 275 OUT int *Which, 276 OUT wchar_t **MapPath 277 ) 278 { 279 int MapLen; 280 PATH_CLASS PathClass; 281 wchar_t *NewPath; 282 wchar_t *WPath = NULL; 283 wchar_t *MPath = NULL; 284 DeviceNode *Node = NULL; 285 RETURN_STATUS Status = RETURN_NOT_FOUND; 286 int Instance = 0; 287 BOOLEAN ReMapped; 288 289 ReMapped = FALSE; 290 291 // Convert name from MBCS to WCS and change '/' to '\\' 292 WPath = NormalizePath( path); 293 PathClass = ClassifyPath(WPath, &NewPath, &MapLen); 294 295 reclassify: 296 switch(PathClass) { 297 case PathMapping: 298 if(!ReMapped) { 299 if((NewPath == NULL) || (*NewPath == L'\0')) { /* Nothing after the ':' */ 300 PathClass = PathAbsolute; 301 } 302 else { 303 Instance = PathInstance(WPath, MapLen); 304 PathClass = ClassifyPath(NewPath, NULL, NULL); 305 } 306 ReMapped = TRUE; 307 if(WPath[MapLen] == L':') { 308 // Get the Map Name, including the trailing ':'. */ 309 MPath = calloc(MapLen+2, sizeof(wchar_t)); 310 if(MPath != NULL) { 311 wmemcpy(MPath, WPath, MapLen+1); 312 } 313 else { 314 errno = ENOMEM; 315 Status = RETURN_OUT_OF_RESOURCES; 316 break; // Exit the switch(PathClass) statement. 317 } 318 } 319 if(WPath != NewPath) { 320 /* Shift the RHS of the path down to the start of the buffer. */ 321 wmemmove(WPath, NewPath, wcslen(NewPath)+1); 322 NewPath = WPath; 323 } 324 goto reclassify; 325 } 326 /* Fall through to PathError if Remapped. 327 This means that the path looked like "foo:bar:something". 328 */ 329 330 case PathError: 331 errno = EINVAL; 332 Status = RETURN_INVALID_PARAMETER; 333 break; 334 335 case PathRelative: 336 /* Transform a relative path into an Absolute path. 337 Prepends CWD and handles ./ and ../ entries. 338 It is the caller's responsibility to free the space 339 allocated to WPath. 340 */ 341 WPath = PathAdjust(NewPath); // WPath was malloc()ed by PathAdjust 342 343 case PathAbsolute: 344 /* Perform any path aliasing. For example: /dev/foo -> { node.foo, "" } 345 The current volume and directory are updated in the path as needed. 346 It is the caller's responsibility to free the space 347 allocated to WPath. 348 */ 349 Status = RETURN_SUCCESS; 350 WPath = PathAlias(WPath, &Node); // PathAlias frees its argument and malloc()s a new one. 351 break; 352 } 353 if(!RETURN_ERROR(Status)) { 354 *FullPath = WPath; 355 *Which = Instance; 356 if(MapPath != NULL) { 357 *MapPath = MPath; 358 } 359 else if(MPath != NULL) { 360 free(MPath); /* Caller doesn't want it so let MPath go free */ 361 } 362 363 /* At this point, WPath is an absolute path, 364 MPath is either NULL or points to the Map Name, 365 and Instance is the instance number. 366 */ 367 if(MPath == NULL) { 368 /* This is NOT a mapped path. */ 369 if(Node == NULL) { 370 Node = daDefaultDevice; 371 } 372 if(Node != NULL) { 373 Status = RETURN_SUCCESS; 374 } 375 else { 376 Status = RETURN_NOT_FOUND; 377 } 378 } 379 else { 380 /* This is a mapped path. */ 381 Status = __DevSearch( MPath, NULL, &Node); 382 if(Status == RETURN_NOT_FOUND) { 383 Node = daDefaultDevice; 384 385 if(Node != NULL) { 386 Status = RETURN_SUCCESS; 387 } 388 } 389 } 390 if(DevNode != NULL) { 391 *DevNode = Node; 392 } 393 } 394 return Status; 395 } 396 397 /** 398 Parses a normalized wide character path and returns a pointer to the entry 399 following the last \. If a \ is not found in the path the return value will 400 be the same as the input value. All error conditions return NULL. 401 402 The behavior when passing in a path that has not been normalized is undefined. 403 404 @param Path - A pointer to a wide character string containing a path to a 405 directory or a file. 406 407 @return Pointer to the file name or terminal directory. NULL if an error is 408 detected. 409 **/ 410 wchar_t * 411 EFIAPI 412 GetFileNameFromPath ( 413 const wchar_t *Path 414 ) 415 { 416 wchar_t *Tail; 417 418 if (Path == NULL) { 419 return NULL; 420 } 421 422 Tail = wcsrchr(Path, L'\\'); 423 if(Tail == NULL) { 424 Tail = (wchar_t *) Path; 425 } else { 426 // Move to the next character after the '\\' to get the file name. 427 Tail++; 428 } 429 430 return Tail; 431 } 432