Hello Marvin! That seems there will be another revision based on Pedro Falcato's comments, so in the next version I solved all the remarks from you.
Best regards, Savva Mitrofanov > On 28 Jul 2022, at 22:43, Marvin Häuser <mhaeu...@posteo.de> wrote: > > Looks very nice, tyvm. I did add a few more comments, but nothing critical at > all. > > Reviewed-by: Marvin Häuser <mhaeu...@posteo.de> as-is or with my comments > addressed, either works. > >> On 28. Jul 2022, at 17:26, Savva Mitrofanov <savva...@gmail.com> wrote: >> >> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3677 >> >> Provided support for symlink file type. Added routine which allows >> reading and following them through recursive open() call. As a security >> meausure implemented simple symlink loop check with nest level limit >> equal 8. Also this patch moves Ext4Open functionality to internal >> routine. >> >> Cc: Marvin Häuser <mhaeu...@posteo.de> >> Cc: Pedro Falcato <pedro.falc...@gmail.com> >> Cc: Vitaly Cheptsov <vit9...@protonmail.com> >> Signed-off-by: Savva Mitrofanov <savva...@gmail.com> >> --- >> Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h | 13 +- >> Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h | 98 +++++- >> Features/Ext4Pkg/Ext4Dxe/File.c | 359 ++++++++++++++++++-- >> Features/Ext4Pkg/Ext4Dxe/Inode.c | 53 +++ >> 4 files changed, 485 insertions(+), 38 deletions(-) >> >> diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h >> b/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h >> index a55cd2fa68ad..a73e3f8622f1 100644 >> --- a/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h >> +++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h >> @@ -171,7 +171,7 @@ >> #define EXT4_DIRTY_FL 0x00000100 >> #define EXT4_COMPRBLK_FL 0x00000200 >> #define EXT4_NOCOMPR_FL 0x00000400 >> -#define EXT4_ECOMPR_FL 0x00000800 >> +#define EXT4_ENCRYPT_FL 0x00000800 >> #define EXT4_BTREE_FL 0x00001000 >> #define EXT4_INDEX_FL 0x00002000 >> #define EXT4_JOURNAL_DATA_FL 0x00004000 >> @@ -332,11 +332,12 @@ STATIC_ASSERT ( >> "ext4 block group descriptor struct has incorrect size" >> ); >> >> -#define EXT4_DBLOCKS 12 >> -#define EXT4_IND_BLOCK 12 >> -#define EXT4_DIND_BLOCK 13 >> -#define EXT4_TIND_BLOCK 14 >> -#define EXT4_NR_BLOCKS 15 >> +#define EXT4_DBLOCKS 12 >> +#define EXT4_IND_BLOCK 12 >> +#define EXT4_DIND_BLOCK 13 >> +#define EXT4_TIND_BLOCK 14 >> +#define EXT4_NR_BLOCKS 15 >> +#define EXT4_FAST_SYMLINK_MAX_SIZE EXT4_NR_BLOCKS * sizeof(UINT32) >> >> #define EXT4_GOOD_OLD_INODE_SIZE 128 >> >> diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h >> b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h >> index b1508482b0a7..c1df9d1149e4 100644 >> --- a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h >> +++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h >> @@ -31,7 +31,9 @@ >> >> #include "Ext4Disk.h" >> >> +#define SYMLOOP_MAX 8 >> #define EXT4_NAME_MAX 255 >> +#define EFI_PATH_MAX 4096 >> >> #define EXT4_DRIVER_VERSION 0x0000 >> >> @@ -324,11 +326,11 @@ number of read bytes. >> **/ >> EFI_STATUS >> Ext4Read ( >> - IN EXT4_PARTITION *Partition, >> - IN EXT4_FILE *File, >> - OUT VOID *Buffer, >> - IN UINT64 Offset, >> - IN OUT UINTN *Length >> + IN EXT4_PARTITION *Partition, >> + IN EXT4_FILE *File, >> + OUT VOID *Buffer, >> + IN UINT64 Offset, >> + IN OUT UINTN *Length >> ); >> >> /** >> @@ -368,6 +370,7 @@ struct _Ext4File { >> >> UINT64 OpenMode; >> UINT64 Position; >> + UINT32 SymLoops; >> >> EXT4_PARTITION *Partition; >> >> @@ -497,6 +500,45 @@ Ext4SetupFile ( >> IN EXT4_PARTITION *Partition >> ); >> >> +/** >> + Opens a new file relative to the source file's location. >> + >> + @param[out] FoundFile A pointer to the location to return the opened >> handle for the new >> + file. >> + @param[in] Source A pointer to the EXT4_FILE instance that is the >> file >> + handle to the source location. This would >> typically be an open >> + handle to a directory. >> + @param[in] FileName The Null-terminated string of the name of the file >> to be opened. >> + The file name may contain the following path >> modifiers: "\", ".", >> + and "..". >> + @param[in] OpenMode The mode to open the file. The only valid >> combinations that the >> + file may be opened with are: Read, Read/Write, or >> Create/Read/Write. >> + @param[in] Attributes Only valid for EFI_FILE_MODE_CREATE, in which case >> these are the >> + attribute bits for the newly created file. >> + >> + @retval EFI_SUCCESS The file was opened. >> + @retval EFI_NOT_FOUND The specified file could not be found on the >> device. >> + @retval EFI_NO_MEDIA The device has no medium. >> + @retval EFI_MEDIA_CHANGED The device has a different medium in it or >> the medium is no >> + longer supported. >> + @retval EFI_DEVICE_ERROR The device reported an error. >> + @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted. >> + @retval EFI_WRITE_PROTECTED An attempt was made to create a file, or >> open a file for write >> + when the media is write-protected. >> + @retval EFI_ACCESS_DENIED The service denied access to the file. >> + @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open >> the file. >> + @retval EFI_VOLUME_FULL The volume is full. >> + >> +**/ >> +EFI_STATUS >> +Ext4OpenInternal ( >> + OUT EXT4_FILE **FoundFile, >> + IN EXT4_FILE *Source, >> + IN CHAR16 *FileName, >> + IN UINT64 OpenMode, >> + IN UINT64 Attributes >> + ); >> + >> /** >> Closes a file. >> >> @@ -774,6 +816,30 @@ Ext4FileIsDir ( >> IN CONST EXT4_FILE *File >> ); >> >> +/** >> + Checks if a file is a symlink. >> + >> + @param[in] File Pointer to the opened file. >> + >> + @return BOOLEAN Whether file is a symlink >> +**/ >> +BOOLEAN >> +Ext4FileIsSymlink ( >> + IN CONST EXT4_FILE *File >> + ); >> + >> +/** >> + Detects if a symlink is a fast symlink. >> + >> + @param[in] File Pointer to the opened file. >> + >> + @return BOOLEAN Whether symlink is a fast symlink >> +**/ >> +BOOLEAN >> +Ext4SymlinkIsFastSymlink ( >> + IN CONST EXT4_FILE *File >> + ); >> + >> /** >> Checks if a file is a regular file. >> @param[in] File Pointer to the opened file. >> @@ -797,7 +863,7 @@ Ext4FileIsReg ( >> it's a regular file or a directory, since most other file types >> don't make sense under UEFI. >> **/ >> -#define Ext4FileIsOpenable(File) (Ext4FileIsReg(File) || >> Ext4FileIsDir(File)) >> +#define Ext4FileIsOpenable(File) (Ext4FileIsReg (File) || Ext4FileIsDir >> (File) || Ext4FileIsSymlink (File)) >> >> #define EXT4_INODE_HAS_FIELD(Inode, Field) >> \ >> (Inode->i_extra_isize + EXT4_GOOD_OLD_INODE_SIZE >= >> \ >> @@ -935,6 +1001,26 @@ Ext4ReadDir ( >> IN OUT UINTN *OutLength >> ); >> >> +/** >> + Reads a symlink file. >> + >> + @param[in] Partition Pointer to the ext4 partition. >> + @param[in] File Pointer to the open symlink file. >> + @param[out] Symlink Pointer to the output unicode symlink string. >> + >> + @retval EFI_SUCCESS Symlink was read. >> + @retval EFI_ACCESS_DENIED Symlink is encrypted. >> + @retval EFI_OUT_OF_RESOURCES Memory allocation error. >> + @retval EFI_INVALID_PARAMETER Symlink path has incorrect length >> + @retval EFI_VOLUME_CORRUPTED Symlink read block size differ from inode >> value >> +**/ >> +EFI_STATUS >> +Ext4ReadSymlink ( >> + IN EXT4_PARTITION *Partition, >> + IN EXT4_FILE *File, >> + OUT CHAR16 **Symlink >> + ); >> + >> /** >> Initialises the (empty) extents map, that will work as a cache of extents. >> >> diff --git a/Features/Ext4Pkg/Ext4Dxe/File.c >> b/Features/Ext4Pkg/Ext4Dxe/File.c >> index ff1746d5640a..ae9230d6422b 100644 >> --- a/Features/Ext4Pkg/Ext4Dxe/File.c >> +++ b/Features/Ext4Pkg/Ext4Dxe/File.c >> @@ -134,14 +134,224 @@ Ext4DirCanLookup ( >> return (File->Inode->i_mode & EXT4_INO_PERM_EXEC_OWNER) == >> EXT4_INO_PERM_EXEC_OWNER; >> } >> >> +/** >> + Reads a fast symlink file. >> + >> + @param[in] Partition Pointer to the ext4 partition. >> + @param[in] File Pointer to the open symlink file. >> + @param[out] AsciiSymlink Pointer to the output ascii symlink >> string. >> + @param[out] AsciiSymlinkSize Pointer to the output ascii symlink >> string length. >> + >> + @retval EFI_SUCCESS Fast symlink was read. >> + @retval EFI_OUT_OF_RESOURCES Memory allocation error. >> +**/ >> +STATIC >> +EFI_STATUS >> +Ext4ReadFastSymlink ( >> + IN EXT4_PARTITION *Partition, >> + IN EXT4_FILE *File, >> + OUT CHAR8 **AsciiSymlink, >> + OUT UINT32 *AsciiSymlinkSize >> + ) >> +{ >> + UINT32 SymlinkSize; >> + CHAR8 *AsciiSymlinkTmp; >> + // >> + // Fast-symlink's EXT4_INODE_SIZE is not necessarily validated when we >> checked it in >> + // Ext4SymlinkIsFastSymlink(), so truncate if necessary. >> + // >> + SymlinkSize = (UINT32)MIN (EXT4_INODE_SIZE (File->Inode), >> EXT4_FAST_SYMLINK_MAX_SIZE); >> + >> + AsciiSymlinkTmp = AllocatePool (SymlinkSize + 1); >> + if (AsciiSymlinkTmp == NULL) { >> + DEBUG ((DEBUG_FS, "[ext4] Failed to allocate symlink ascii string >> buffer\n")); >> + return EFI_OUT_OF_RESOURCES; >> + } >> + >> + CopyMem (AsciiSymlinkTmp, File->Inode->i_data, SymlinkSize); >> + >> + // >> + // Add null-terminator >> + // >> + AsciiSymlinkTmp[SymlinkSize] = '\0'; >> + >> + *AsciiSymlink = AsciiSymlinkTmp; >> + *AsciiSymlinkSize = SymlinkSize + 1; >> + >> + return EFI_SUCCESS; >> +} >> + >> +/** >> + Reads a slow symlink file. >> + >> + @param[in] Partition Pointer to the ext4 partition. >> + @param[in] File Pointer to the open symlink file. >> + @param[out] AsciiSymlink Pointer to the output ascii symlink >> string. >> + @param[out] AsciiSymlinkSize Pointer to the output ascii symlink >> string length. >> + >> + @retval EFI_SUCCESS Slow symlink was read. >> + @retval EFI_OUT_OF_RESOURCES Memory allocation error. >> + @retval EFI_INVALID_PARAMETER Slow symlink path has incorrect length >> + @retval EFI_VOLUME_CORRUPTED Symlink read block size differ from inode >> value >> +**/ >> +STATIC >> +EFI_STATUS >> +Ext4ReadSlowSymlink ( >> + IN EXT4_PARTITION *Partition, >> + IN EXT4_FILE *File, >> + OUT CHAR8 **AsciiSymlink, >> + OUT UINT32 *AsciiSymlinkSize >> + ) >> +{ >> + EFI_STATUS Status; >> + CHAR8 *SymlinkTmp; >> + UINT64 SymlinkSizeTmp; >> + UINT32 SymlinkAllocateSize; >> + UINTN ReadSize; >> + >> + SymlinkSizeTmp = EXT4_INODE_SIZE (File->Inode); >> + >> + // >> + // Allocate EXT4_INODE_SIZE + 1 >> + // >> + if (SymlinkSizeTmp > EFI_PATH_MAX - 1) { >> + DEBUG (( >> + DEBUG_FS, >> + "[ext4] Error! Symlink path maximum length was hit!\n" >> + )); >> + return EFI_INVALID_PARAMETER; >> + } >> + >> + SymlinkAllocateSize = (UINT32)SymlinkSizeTmp + 1; >> + >> + SymlinkTmp = AllocatePool (SymlinkAllocateSize); >> + if (SymlinkTmp == NULL) { >> + DEBUG ((DEBUG_FS, "[ext4] Failed to allocate symlink ascii string >> buffer\n")); >> + return EFI_OUT_OF_RESOURCES; >> + } >> + >> + ReadSize = (UINTN)SymlinkSizeTmp; >> + Status = Ext4Read (Partition, File, SymlinkTmp, File->Position, >> &ReadSize); >> + if (EFI_ERROR (Status)) { >> + DEBUG ((DEBUG_FS, "[ext4] Failed to read symlink from blocks with >> Status %r\n", Status)); >> + FreePool (SymlinkTmp); >> + return Status; >> + } >> + >> + File->Position += ReadSize; >> + >> + // >> + // Add null-terminator >> + // >> + SymlinkTmp[SymlinkSizeTmp] = '\0'; >> + >> + if (SymlinkSizeTmp != ReadSize) { >> + DEBUG (( >> + DEBUG_FS, >> + "[ext4] Error! The sz of the read block doesn't match the value from >> the inode!\n" >> + )); >> + return EFI_VOLUME_CORRUPTED; >> + } >> + >> + *AsciiSymlinkSize = SymlinkAllocateSize; >> + *AsciiSymlink = SymlinkTmp; >> + >> + return EFI_SUCCESS; >> +} >> + >> +/** >> + Reads a symlink file. >> + >> + @param[in] Partition Pointer to the ext4 partition. >> + @param[in] File Pointer to the open symlink file. >> + @param[out] Symlink Pointer to the output unicode symlink string. >> + >> + @retval EFI_SUCCESS Symlink was read. >> + @retval EFI_ACCESS_DENIED Symlink is encrypted. >> + @retval EFI_OUT_OF_RESOURCES Memory allocation error. >> + @retval EFI_INVALID_PARAMETER Symlink path has incorrect length >> + @retval EFI_VOLUME_CORRUPTED Symlink read block size differ from inode >> value >> +**/ >> +EFI_STATUS >> +Ext4ReadSymlink ( >> + IN EXT4_PARTITION *Partition, >> + IN EXT4_FILE *File, >> + OUT CHAR16 **Symlink >> + ) >> +{ >> + EFI_STATUS Status; >> + CHAR8 *SymlinkTmp; >> + UINT32 SymlinkSize; >> + CHAR16 *Symlink16Tmp; >> + CHAR16 *Needle; >> + >> + // >> + // Assume that we alread read Inode via Ext4ReadInode >> + // Skip reading, just check encryption flag >> + // >> + if ((File->Inode->i_flags & EXT4_ENCRYPT_FL) != 0) { >> + DEBUG ((DEBUG_FS, "[ext4] Error, symlink is encrypted\n")); >> + return EFI_ACCESS_DENIED; >> + } >> + >> + if (Ext4SymlinkIsFastSymlink (File)) { >> + Status = Ext4ReadFastSymlink (Partition, File, &SymlinkTmp, >> &SymlinkSize); >> + } else { >> + Status = Ext4ReadSlowSymlink (Partition, File, &SymlinkTmp, >> &SymlinkSize); >> + } >> + >> + if (EFI_ERROR (Status)) { >> + DEBUG ((DEBUG_FS, "[ext4] Symlink read error with Status %r\n", >> Status)); >> + return Status; >> + } >> + >> + Symlink16Tmp = AllocateZeroPool (SymlinkSize * sizeof (CHAR16)); > > Any specific reason to use ZeroPool here, when the rest of the code doesn’t? > >> + if (Symlink16Tmp == NULL) { >> + DEBUG ((DEBUG_FS, "[ext4] Failed to allocate symlink unicode string >> buffer\n")); >> + FreePool (SymlinkTmp); >> + return EFI_OUT_OF_RESOURCES; >> + } >> + >> + Status = AsciiStrToUnicodeStrS ( >> + SymlinkTmp, >> + Symlink16Tmp, >> + SymlinkSize >> + ); > > Can’t SymlinkTmp be free’d here? > >> + >> + if (EFI_ERROR (Status)) { >> + DEBUG (( >> + DEBUG_FS, >> + "[ext4] Failed to convert ascii symlink to unicode with Status %r\n", >> + Status >> + )); >> + FreePool (Symlink16Tmp); >> + FreePool (SymlinkTmp); >> + return Status; >> + } >> + >> + // >> + // Convert to UEFI slashes >> + // >> + for (Needle = Symlink16Tmp; *Needle != L'\0'; Needle++) { >> + if (*Needle == L'/') { >> + *Needle = L'\\'; >> + } >> + } >> + >> + *Symlink = Symlink16Tmp; >> + >> + FreePool (SymlinkTmp); >> + return Status; >> +} >> + >> /** >> Opens a new file relative to the source file's location. >> >> - @param[in] This A pointer to the EFI_FILE_PROTOCOL instance that >> is the file >> + @param[out] FoundFile A pointer to the location to return the opened >> handle for the new >> + file. >> + @param[in] Source A pointer to the EXT4_FILE instance that is the >> file >> handle to the source location. This would typically >> be an open >> handle to a directory. >> - @param[out] NewHandle A pointer to the location to return the opened >> handle for the new >> - file. >> @param[in] FileName The Null-terminated string of the name of the file >> to be opened. >> The file name may contain the following path >> modifiers: "\", ".", >> and "..". >> @@ -165,13 +375,12 @@ Ext4DirCanLookup ( >> >> **/ >> EFI_STATUS >> -EFIAPI >> -Ext4Open ( >> - IN EFI_FILE_PROTOCOL *This, >> - OUT EFI_FILE_PROTOCOL **NewHandle, >> - IN CHAR16 *FileName, >> - IN UINT64 OpenMode, >> - IN UINT64 Attributes >> +Ext4OpenInternal ( >> + OUT EXT4_FILE **FoundFile, >> + IN EXT4_FILE *Source, >> + IN CHAR16 *FileName, >> + IN UINT64 OpenMode, >> + IN UINT64 Attributes >> ) >> { >> EXT4_FILE *Current; >> @@ -180,13 +389,14 @@ Ext4Open ( >> CHAR16 PathSegment[EXT4_NAME_MAX + 1]; >> UINTN Length; >> EXT4_FILE *File; >> + CHAR16 *Symlink; >> EFI_STATUS Status; >> >> - Current = (EXT4_FILE *)This; >> + Current = Source; >> Partition = Current->Partition; >> Level = 0; >> >> - DEBUG ((DEBUG_FS, "[ext4] Ext4Open %s\n", FileName)); >> + DEBUG ((DEBUG_FS, "[ext4] Ext4OpenInternal %s\n", FileName)); >> // If the path starts with a backslash, we treat the root directory as the >> base directory >> if (FileName[0] == L'\\') { >> FileName++; >> @@ -194,6 +404,11 @@ Ext4Open ( >> } >> >> while (FileName[0] != L'\0') { >> + if (Partition->Root->SymLoops > SYMLOOP_MAX) { >> + DEBUG ((DEBUG_FS, "[ext4] Symloop limit is hit !\n")); >> + return EFI_ACCESS_DENIED; >> + } >> + >> // Discard leading path separators >> while (FileName[0] == L'\\') { >> FileName++; >> @@ -238,18 +453,45 @@ Ext4Open ( >> } >> >> // Check if this is a valid file to open in EFI >> - >> - // What to do with symlinks? They're nonsense when absolute but may >> - // be useful when they're relative. Right now, they're ignored, since >> they >> - // bring a lot of trouble for something that's not as useful in our >> case. >> - // If you want to link, use hard links. >> - >> if (!Ext4FileIsOpenable (File)) { >> Ext4CloseInternal (File); >> // This looks like an /okay/ status to return. >> return EFI_ACCESS_DENIED; >> } >> >> + // >> + // Reading symlink and then trying to follow it >> + // >> + if (Ext4FileIsSymlink (File)) { >> + Partition->Root->SymLoops++; >> + DEBUG ((DEBUG_FS, "[ext4] File %s is symlink, trying to read it\n", >> PathSegment)); >> + Status = Ext4ReadSymlink (Partition, File, &Symlink); >> + if (EFI_ERROR (Status)) { >> + DEBUG ((DEBUG_FS, "[ext4] Error reading %s symlink!\n", >> PathSegment)); >> + return Status; >> + } >> + >> + DEBUG ((DEBUG_FS, "[ext4] File %s is linked to %s\n", PathSegment, >> Symlink)); >> + // >> + // Close symlink file >> + // >> + Ext4CloseInternal (File); >> + // >> + // Open linked file by recursive call of Ext4OpenFile >> + // >> + Status = Ext4OpenInternal (FoundFile, Current, Symlink, OpenMode, >> Attributes); >> + FreePool (Symlink); >> + if (EFI_ERROR (Status)) { >> + DEBUG ((DEBUG_FS, "[ext4] Error opening linked file %s\n", >> Symlink)); >> + return Status; >> + } >> + >> + // >> + // Set File to newly opened >> + // >> + File = *FoundFile; >> + } >> + >> if (Level != 0) { >> // Careful not to close the base directory >> Ext4CloseInternal (Current); >> @@ -273,12 +515,75 @@ Ext4Open ( >> return EFI_ACCESS_DENIED; >> } >> >> - *NewHandle = &Current->Protocol; >> + *FoundFile = Current; >> >> DEBUG ((DEBUG_FS, "[ext4] Opened filename %s\n", Current->Dentry->Name)); >> return EFI_SUCCESS; >> } >> >> +/** >> + Opens a new file relative to the source file's location. >> + @param[in] This A pointer to the EFI_FILE_PROTOCOL instance that >> is the file >> + handle to the source location. This would >> typically be an open >> + handle to a directory. >> + @param[out] NewHandle A pointer to the location to return the opened >> handle for the new >> + file. >> + @param[in] FileName The Null-terminated string of the name of the file >> to be opened. >> + The file name may contain the following path >> modifiers: "\", ".", >> + and "..". >> + @param[in] OpenMode The mode to open the file. The only valid >> combinations that the >> + file may be opened with are: Read, Read/Write, or >> Create/Read/Write. >> + @param[in] Attributes Only valid for EFI_FILE_MODE_CREATE, in which case >> these are the >> + attribute bits for the newly created file. >> + @retval EFI_SUCCESS The file was opened. >> + @retval EFI_NOT_FOUND The specified file could not be found on the >> device. >> + @retval EFI_NO_MEDIA The device has no medium. >> + @retval EFI_MEDIA_CHANGED The device has a different medium in it or >> the medium is no >> + longer supported. >> + @retval EFI_DEVICE_ERROR The device reported an error. >> + @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted. >> + @retval EFI_WRITE_PROTECTED An attempt was made to create a file, or >> open a file for write >> + when the media is write-protected. >> + @retval EFI_ACCESS_DENIED The service denied access to the file. >> + @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open >> the file. >> + @retval EFI_VOLUME_FULL The volume is full. >> +**/ >> +EFI_STATUS >> +EFIAPI >> +Ext4Open ( >> + IN EFI_FILE_PROTOCOL *This, >> + OUT EFI_FILE_PROTOCOL **NewHandle, >> + IN CHAR16 *FileName, >> + IN UINT64 OpenMode, >> + IN UINT64 Attributes >> + ) >> +{ >> + EFI_STATUS Status; >> + EXT4_FILE *FoundFile; >> + EXT4_FILE *Source; >> + >> + Source = (EXT4_FILE *)This; >> + >> + // >> + // Reset SymLoops counter >> + // >> + Source->Partition->Root->SymLoops = 0; >> + >> + Status = Ext4OpenInternal ( >> + &FoundFile, >> + Source, >> + FileName, >> + OpenMode, >> + Attributes >> + ); >> + >> + if (!EFI_ERROR (Status)) { >> + *NewHandle = &FoundFile->Protocol; >> + } >> + >> + return Status; >> +} >> + >> /** >> Closes a specified file handle. >> >> @@ -588,7 +893,7 @@ Ext4GetVolumeName ( >> >> // s_volume_name is only valid on dynamic revision; old filesystems don't >> support this >> if (Partition->SuperBlock.s_rev_level == EXT4_DYNAMIC_REV) { >> - CopyMem (TempVolName, (CONST CHAR8 >> *)Partition->SuperBlock.s_volume_name, 16); >> + CopyMem (TempVolName, Partition->SuperBlock.s_volume_name, 16); >> TempVolName[16] = '\0'; >> >> Status = UTF8StrToUCS2 (TempVolName, &VolumeName); >> @@ -754,12 +1059,14 @@ Ext4GetInfo ( >> OUT VOID *Buffer >> ) >> { >> + EXT4_FILE *File; >> EXT4_PARTITION *Partition; >> >> - Partition = ((EXT4_FILE *)This)->Partition; >> + File = (EXT4_FILE *)This; >> + Partition = File->Partition; >> >> if (CompareGuid (InformationType, &gEfiFileInfoGuid)) { >> - return Ext4GetFileInfo ((EXT4_FILE *)This, Buffer, BufferSize); >> + return Ext4GetFileInfo (File, Buffer, BufferSize); >> } >> >> if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) { >> @@ -870,12 +1177,12 @@ Ext4SetInfo ( >> ) >> { >> EXT4_FILE *File; >> - EXT4_PARTITION *Part; >> + EXT4_PARTITION *Partition; >> >> - File = (EXT4_FILE *)This; >> - Part = File->Partition; >> + File = (EXT4_FILE *)This; >> + Partition = File->Partition; >> >> - if (Part->ReadOnly) { >> + if (Partition->ReadOnly) { >> return EFI_WRITE_PROTECTED; >> } >> >> diff --git a/Features/Ext4Pkg/Ext4Dxe/Inode.c >> b/Features/Ext4Pkg/Ext4Dxe/Inode.c >> index 831f5946e870..e7a6b3225709 100644 >> --- a/Features/Ext4Pkg/Ext4Dxe/Inode.c >> +++ b/Features/Ext4Pkg/Ext4Dxe/Inode.c >> @@ -255,6 +255,59 @@ Ext4FileIsDir ( >> return (File->Inode->i_mode & EXT4_INO_TYPE_DIR) == EXT4_INO_TYPE_DIR; >> } >> >> +/** >> + Checks if a file is a symlink. >> + >> + @param[in] File Pointer to the opened file. >> + >> + @return BOOLEAN Whether file is a symlink >> +**/ >> +BOOLEAN >> +Ext4FileIsSymlink ( >> + IN CONST EXT4_FILE *File >> + ) >> +{ >> + return (File->Inode->i_mode & EXT4_INO_TYPE_SYMLINK) == >> EXT4_INO_TYPE_SYMLINK; >> +} >> + >> +/** >> + Detects if a symlink is a fast symlink. >> + >> + @param[in] File Pointer to the opened file. >> + >> + @return BOOLEAN Whether symlink is a fast symlink >> +**/ >> +BOOLEAN >> +Ext4SymlinkIsFastSymlink ( >> + IN CONST EXT4_FILE *File >> + ) >> +{ >> + // >> + // Detection logic of the fast-symlink splits into two behaviors - old >> and new. >> + // The old behavior is based on comparing the extended attribute blocks >> + // with the inode's i_blocks, and if it's zero we know the inode isn't >> storing >> + // the link in filesystem blocks, so we look to the inode->i_data. >> + // The new behavior is apparently needed only with the large EA inode >> feature. >> + // In this case we check that inode size less than maximum fast symlink >> size. >> + // So, we revert to the old behavior if the large EA inode feature is not >> set. >> + // >> + UINT32 FileAcl; >> + UINT32 ExtAttrBlocks; >> + >> + if ((File->Inode->i_flags & EXT4_EA_INODE_FL) == 0) { >> + FileAcl = File->Inode->i_file_acl; >> + if (EXT4_IS_64_BIT (File->Partition)) { >> + FileAcl |= LShiftU64 >> (File->Inode->i_osd2.data_linux.l_i_file_acl_high, 32); > > *If* you happen to do a new revision anyway, you could drop the shift (with a > comment!) if you want, because we don’t care about the actual value, just > whether any one bit is set. Don’t bother if there won’t be a new revision > anyway, though. :) > >> + } >> + >> + ExtAttrBlocks = FileAcl != 0 ? (File->Partition->BlockSize >> 9) : 0; >> + >> + return File->Inode->i_blocks == ExtAttrBlocks; >> + } >> + >> + return EXT4_INODE_SIZE (File->Inode) <= EXT4_FAST_SYMLINK_MAX_SIZE; >> +} >> + >> /** >> Checks if a file is a regular file. >> @param[in] File Pointer to the opened file. >> -- >> 2.37.1 >> > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#93117): https://edk2.groups.io/g/devel/message/93117 Mute This Topic: https://groups.io/mt/92672600/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
