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50944545 | 1 | /** @file |
2 | File System Access for NvVarsFileLib | |
3 | ||
59b19469 | 4 | Copyright (c) 2004 - 2011, Intel Corporation. All rights reserved.<BR> |
56d7640a | 5 | This program and the accompanying materials |
50944545 | 6 | are licensed and made available under the terms and conditions of the BSD License |
7 | which accompanies this distribution. 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 | **/ | |
14 | ||
15 | #include "NvVarsFileLib.h" | |
16 | ||
17 | #include <Library/BaseMemoryLib.h> | |
18 | #include <Library/DebugLib.h> | |
19 | #include <Library/MemoryAllocationLib.h> | |
20 | ||
21 | ||
22 | /** | |
23 | Open the NvVars file for reading or writing | |
24 | ||
25 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
26 | @param[in] ReadingFile - TRUE: open the file for reading. FALSE: writing | |
27 | @param[out] NvVarsFile - If EFI_SUCCESS is returned, then this is updated | |
28 | with the opened NvVars file. | |
29 | ||
30 | @return EFI_SUCCESS if the file was opened | |
31 | ||
32 | **/ | |
33 | EFI_STATUS | |
34 | GetNvVarsFile ( | |
35 | IN EFI_HANDLE FsHandle, | |
36 | IN BOOLEAN ReadingFile, | |
37 | OUT EFI_FILE_HANDLE *NvVarsFile | |
38 | ) | |
39 | { | |
40 | EFI_STATUS Status; | |
41 | EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Fs; | |
42 | EFI_FILE_HANDLE Root; | |
43 | ||
44 | // | |
45 | // Get the FileSystem protocol on that handle | |
46 | // | |
47 | Status = gBS->HandleProtocol ( | |
48 | FsHandle, | |
49 | &gEfiSimpleFileSystemProtocolGuid, | |
50 | (VOID **)&Fs | |
51 | ); | |
52 | if (EFI_ERROR (Status)) { | |
53 | return Status; | |
54 | } | |
55 | ||
56 | // | |
57 | // Get the volume (the root directory) | |
58 | // | |
59 | Status = Fs->OpenVolume (Fs, &Root); | |
60 | if (EFI_ERROR (Status)) { | |
61 | return Status; | |
62 | } | |
63 | ||
64 | // | |
65 | // Attempt to open the NvVars file in the root directory | |
66 | // | |
67 | Status = Root->Open ( | |
68 | Root, | |
69 | NvVarsFile, | |
70 | L"NvVars", | |
71 | ReadingFile ? | |
72 | EFI_FILE_MODE_READ : | |
73 | ( | |
74 | EFI_FILE_MODE_CREATE | | |
75 | EFI_FILE_MODE_READ | | |
76 | EFI_FILE_MODE_WRITE | |
77 | ), | |
78 | 0 | |
79 | ); | |
80 | if (EFI_ERROR (Status)) { | |
81 | return Status; | |
82 | } | |
83 | ||
84 | return Status; | |
85 | } | |
86 | ||
87 | ||
88 | /** | |
89 | Open the NvVars file for reading or writing | |
90 | ||
91 | @param[in] File - The file to inspect | |
92 | @param[out] Exists - Returns whether the file exists | |
93 | @param[out] Size - Returns the size of the file | |
94 | (0 if the file does not exist) | |
95 | ||
96 | **/ | |
97 | VOID | |
98 | NvVarsFileReadCheckup ( | |
99 | IN EFI_FILE_HANDLE File, | |
100 | OUT BOOLEAN *Exists, | |
101 | OUT UINTN *Size | |
102 | ) | |
103 | { | |
104 | EFI_FILE_INFO *FileInfo; | |
105 | ||
106 | *Exists = FALSE; | |
107 | *Size = 0; | |
108 | ||
109 | FileInfo = FileHandleGetInfo (File); | |
110 | if (FileInfo == NULL) { | |
111 | return; | |
112 | } | |
113 | ||
114 | if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) { | |
115 | FreePool (FileInfo); | |
116 | return; | |
117 | } | |
118 | ||
119 | *Exists = TRUE; | |
7d9cf3f2 | 120 | *Size = (UINTN) FileInfo->FileSize; |
50944545 | 121 | |
122 | FreePool (FileInfo); | |
123 | } | |
124 | ||
125 | ||
126 | /** | |
127 | Open the NvVars file for reading or writing | |
128 | ||
129 | @param[in] File - The file to inspect | |
130 | @param[out] Exists - Returns whether the file exists | |
131 | @param[out] Size - Returns the size of the file | |
132 | (0 if the file does not exist) | |
133 | ||
134 | **/ | |
135 | EFI_STATUS | |
136 | FileHandleEmpty ( | |
137 | IN EFI_FILE_HANDLE File | |
138 | ) | |
139 | { | |
140 | EFI_STATUS Status; | |
141 | EFI_FILE_INFO *FileInfo; | |
142 | ||
143 | // | |
144 | // Retrieve the FileInfo structure | |
145 | // | |
146 | FileInfo = FileHandleGetInfo (File); | |
147 | if (FileInfo == NULL) { | |
148 | return EFI_INVALID_PARAMETER; | |
149 | } | |
150 | ||
151 | // | |
152 | // If the path is a directory, then return an error | |
153 | // | |
154 | if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) { | |
155 | FreePool (FileInfo); | |
156 | return EFI_INVALID_PARAMETER; | |
157 | } | |
158 | ||
159 | // | |
160 | // If the file size is already 0, then it is empty, so | |
161 | // we can return success. | |
162 | // | |
163 | if (FileInfo->FileSize == 0) { | |
164 | FreePool (FileInfo); | |
165 | return EFI_SUCCESS; | |
166 | } | |
167 | ||
168 | // | |
169 | // Set the file size to 0. | |
170 | // | |
171 | FileInfo->FileSize = 0; | |
172 | Status = FileHandleSetInfo (File, FileInfo); | |
173 | ||
174 | FreePool (FileInfo); | |
175 | ||
176 | return Status; | |
177 | } | |
178 | ||
179 | ||
180 | /** | |
181 | Reads a file to a newly allocated buffer | |
182 | ||
183 | @param[in] File - The file to read | |
184 | @param[in] ReadSize - The size of data to read from the file | |
185 | ||
186 | @return Pointer to buffer allocated to hold the file | |
187 | contents. NULL if an error occured. | |
188 | ||
189 | **/ | |
190 | VOID* | |
191 | FileHandleReadToNewBuffer ( | |
192 | IN EFI_FILE_HANDLE FileHandle, | |
193 | IN UINTN ReadSize | |
194 | ) | |
195 | { | |
196 | EFI_STATUS Status; | |
197 | UINTN ActualReadSize; | |
198 | VOID *FileContents; | |
199 | ||
200 | ActualReadSize = ReadSize; | |
201 | FileContents = AllocatePool (ReadSize); | |
202 | if (FileContents != NULL) { | |
203 | Status = FileHandleRead ( | |
204 | FileHandle, | |
205 | &ReadSize, | |
206 | FileContents | |
207 | ); | |
208 | if (EFI_ERROR (Status) || (ActualReadSize != ReadSize)) { | |
209 | FreePool (FileContents); | |
210 | return NULL; | |
211 | } | |
212 | } | |
213 | ||
214 | return FileContents; | |
215 | } | |
216 | ||
217 | ||
218 | /** | |
219 | Reads the contents of the NvVars file on the file system | |
220 | ||
221 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
222 | ||
223 | @return EFI_STATUS based on the success or failure of the file read | |
224 | ||
225 | **/ | |
226 | EFI_STATUS | |
227 | ReadNvVarsFile ( | |
228 | IN EFI_HANDLE FsHandle | |
229 | ) | |
230 | { | |
231 | EFI_STATUS Status; | |
232 | EFI_FILE_HANDLE File; | |
233 | UINTN FileSize; | |
234 | BOOLEAN FileExists; | |
235 | VOID *FileContents; | |
59b19469 | 236 | EFI_HANDLE SerializedVariables; |
50944545 | 237 | |
238 | Status = GetNvVarsFile (FsHandle, TRUE, &File); | |
239 | if (EFI_ERROR (Status)) { | |
240 | DEBUG ((EFI_D_INFO, "FsAccess.c: Could not open NV Variables file on this file system\n")); | |
241 | return Status; | |
242 | } | |
243 | ||
244 | NvVarsFileReadCheckup (File, &FileExists, &FileSize); | |
245 | if (FileSize == 0) { | |
246 | FileHandleClose (File); | |
247 | return EFI_UNSUPPORTED; | |
248 | } | |
249 | ||
250 | FileContents = FileHandleReadToNewBuffer (File, FileSize); | |
251 | if (FileContents == NULL) { | |
252 | FileHandleClose (File); | |
253 | return EFI_UNSUPPORTED; | |
254 | } | |
255 | ||
256 | DEBUG (( | |
257 | EFI_D_INFO, | |
258 | "FsAccess.c: Read %d bytes from NV Variables file\n", | |
259 | FileSize | |
260 | )); | |
261 | ||
59b19469 | 262 | Status = SerializeVariablesNewInstanceFromBuffer ( |
263 | &SerializedVariables, | |
264 | FileContents, | |
265 | FileSize | |
266 | ); | |
267 | if (!RETURN_ERROR (Status)) { | |
268 | Status = SerializeVariablesSetSerializedVariables (SerializedVariables); | |
269 | } | |
50944545 | 270 | |
271 | FreePool (FileContents); | |
272 | FileHandleClose (File); | |
273 | ||
274 | return Status; | |
275 | } | |
276 | ||
277 | ||
278 | /** | |
279 | Loads the non-volatile variables from the NvVars file on the | |
280 | given file system. | |
281 | ||
282 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
283 | ||
284 | @return EFI_STATUS based on the success or failure of load operation | |
285 | ||
286 | **/ | |
287 | EFI_STATUS | |
288 | LoadNvVarsFromFs ( | |
289 | EFI_HANDLE FsHandle | |
290 | ) | |
291 | { | |
292 | EFI_STATUS Status; | |
293 | BOOLEAN VarData; | |
294 | UINTN Size; | |
295 | ||
296 | DEBUG ((EFI_D_INFO, "FsAccess.c: LoadNvVarsFromFs\n")); | |
297 | ||
298 | // | |
299 | // We write a variable to indicate we've already loaded the | |
300 | // variable data. If it is found, we skip the loading. | |
301 | // | |
302 | // This is relevent if the non-volatile variable have been | |
303 | // able to survive a reboot operation. In that case, we don't | |
304 | // want to re-load the file as it would overwrite newer changes | |
305 | // made to the variables. | |
306 | // | |
307 | Size = sizeof (VarData); | |
308 | VarData = TRUE; | |
309 | Status = gRT->GetVariable ( | |
310 | L"NvVars", | |
311 | &gEfiSimpleFileSystemProtocolGuid, | |
312 | NULL, | |
313 | &Size, | |
314 | (VOID*) &VarData | |
315 | ); | |
316 | if (Status == EFI_SUCCESS) { | |
317 | DEBUG ((EFI_D_INFO, "NV Variables were already loaded\n")); | |
318 | return EFI_ALREADY_STARTED; | |
319 | } | |
320 | ||
321 | // | |
322 | // Attempt to restore the variables from the NvVars file. | |
323 | // | |
324 | Status = ReadNvVarsFile (FsHandle); | |
325 | if (EFI_ERROR (Status)) { | |
326 | DEBUG ((EFI_D_INFO, "Error while restoring NV variable data\n")); | |
327 | return Status; | |
328 | } | |
329 | ||
330 | // | |
331 | // Write a variable to indicate we've already loaded the | |
332 | // variable data. If it is found, we skip the loading on | |
333 | // subsequent attempts. | |
334 | // | |
335 | Size = sizeof (VarData); | |
336 | VarData = TRUE; | |
337 | gRT->SetVariable ( | |
338 | L"NvVars", | |
339 | &gEfiSimpleFileSystemProtocolGuid, | |
340 | EFI_VARIABLE_NON_VOLATILE | | |
341 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
342 | EFI_VARIABLE_RUNTIME_ACCESS, | |
343 | Size, | |
344 | (VOID*) &VarData | |
345 | ); | |
346 | ||
347 | DEBUG (( | |
348 | EFI_D_INFO, | |
349 | "FsAccess.c: Read NV Variables file (size=%d)\n", | |
350 | Size | |
351 | )); | |
352 | ||
353 | return Status; | |
354 | } | |
355 | ||
356 | ||
59b19469 | 357 | STATIC |
358 | RETURN_STATUS | |
359 | EFIAPI | |
360 | IterateVariablesCallbackAddAllNvVariables ( | |
361 | IN VOID *Context, | |
362 | IN CHAR16 *VariableName, | |
363 | IN EFI_GUID *VendorGuid, | |
364 | IN UINT32 Attributes, | |
365 | IN UINTN DataSize, | |
366 | IN VOID *Data | |
367 | ) | |
368 | { | |
369 | EFI_HANDLE Instance; | |
370 | ||
371 | Instance = (EFI_HANDLE) Context; | |
372 | ||
373 | // | |
374 | // Only save non-volatile variables | |
375 | // | |
376 | if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) { | |
377 | return RETURN_SUCCESS; | |
378 | } | |
379 | ||
380 | return SerializeVariablesAddVariable ( | |
381 | Instance, | |
382 | VariableName, | |
383 | VendorGuid, | |
384 | Attributes, | |
385 | DataSize, | |
386 | Data | |
387 | ); | |
388 | } | |
389 | ||
390 | ||
50944545 | 391 | /** |
392 | Saves the non-volatile variables into the NvVars file on the | |
393 | given file system. | |
394 | ||
395 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
396 | ||
397 | @return EFI_STATUS based on the success or failure of load operation | |
398 | ||
399 | **/ | |
400 | EFI_STATUS | |
401 | SaveNvVarsToFs ( | |
402 | EFI_HANDLE FsHandle | |
403 | ) | |
404 | { | |
405 | EFI_STATUS Status; | |
406 | EFI_FILE_HANDLE File; | |
59b19469 | 407 | UINTN WriteSize; |
50944545 | 408 | UINTN VariableDataSize; |
409 | VOID *VariableData; | |
59b19469 | 410 | EFI_HANDLE SerializedVariables; |
411 | ||
412 | Status = SerializeVariablesNewInstance (&SerializedVariables); | |
413 | if (EFI_ERROR (Status)) { | |
414 | return Status; | |
415 | } | |
416 | ||
417 | Status = SerializeVariablesIterateSystemVariables ( | |
418 | IterateVariablesCallbackAddAllNvVariables, | |
419 | (VOID*) SerializedVariables | |
420 | ); | |
421 | if (EFI_ERROR (Status)) { | |
422 | return Status; | |
423 | } | |
424 | ||
425 | VariableData = NULL; | |
426 | VariableDataSize = 0; | |
427 | Status = SerializeVariablesToBuffer ( | |
428 | SerializedVariables, | |
429 | NULL, | |
430 | &VariableDataSize | |
431 | ); | |
432 | if (Status == RETURN_BUFFER_TOO_SMALL) { | |
433 | VariableData = AllocatePool (VariableDataSize); | |
434 | if (VariableData == NULL) { | |
435 | Status = EFI_OUT_OF_RESOURCES; | |
436 | } else { | |
437 | Status = SerializeVariablesToBuffer ( | |
438 | SerializedVariables, | |
439 | VariableData, | |
440 | &VariableDataSize | |
441 | ); | |
442 | } | |
443 | } | |
444 | ||
445 | SerializeVariablesFreeInstance (SerializedVariables); | |
446 | ||
447 | if (EFI_ERROR (Status)) { | |
448 | return Status; | |
449 | } | |
50944545 | 450 | |
451 | // | |
452 | // Open the NvVars file for writing. | |
453 | // | |
454 | Status = GetNvVarsFile (FsHandle, FALSE, &File); | |
455 | if (EFI_ERROR (Status)) { | |
456 | DEBUG ((EFI_D_INFO, "FsAccess.c: Unable to open file to saved NV Variables\n")); | |
457 | return Status; | |
458 | } | |
459 | ||
460 | // | |
461 | // Empty the starting file contents. | |
462 | // | |
463 | Status = FileHandleEmpty (File); | |
464 | if (EFI_ERROR (Status)) { | |
465 | FileHandleClose (File); | |
466 | return Status; | |
467 | } | |
468 | ||
59b19469 | 469 | WriteSize = VariableDataSize; |
470 | Status = FileHandleWrite (File, &WriteSize, VariableData); | |
471 | if (EFI_ERROR (Status)) { | |
472 | return Status; | |
50944545 | 473 | } |
474 | ||
475 | FileHandleClose (File); | |
476 | ||
477 | if (!EFI_ERROR (Status)) { | |
478 | DEBUG ((EFI_D_INFO, "Saved NV Variables to NvVars file\n")); | |
479 | } | |
480 | ||
481 | return Status; | |
482 | ||
483 | } | |
484 | ||
485 |