Hi Savva, Sorry for the huge delay. Comments inline.
On Thu, Jul 28, 2022 at 4:26 PM 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 > I'm scared that this may not be enough. Could we use 40 here as Linux does? > #define EXT4_NAME_MAX 255 > +#define EFI_PATH_MAX 4096 > Don't use EFI_* in Ext4Dxe code, so prefix this with EXT4_ instead maybe? > > #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, > First IN parameters, then OUT parameters. > + 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 > + ); > Does this need to be in Ext4Dxe.h? This is pretty symlink specific. > + > /** > 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. > + // > I think the correct solution here is to check if the inode size fits in EXT4_FAST_SYMLINK_MAX_SIZE in Ext4SymlinkIsFastSymlink. Or possibly check it here and error-out (blatant corruption). Truncating doesn't seem correct. > + 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")); > Nit: DEBUG_ERROR? > + 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) { > Why is this > EFI_PATH_MAX - 1 and not >= EFI_PATH_MAX? Also, why does the inode size need to be strictly smaller than EFI_PATH_MAX? > + DEBUG (( > + DEBUG_FS, > Nit: DEBUG_ERROR? > + "[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)); > Nit: lowercase "status" in the DEBUG. > + FreePool (SymlinkTmp); > + return Status; > + } > + > + File->Position += ReadSize; > Taking Position into account (here and in the Ext4Read call) seems wrong. Why would the file seek affect the readlink() operation? > + > + // > + // 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" > Nit: size > + )); > + 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")); > Nit: DEBUG_ERROR and "Error: ". > + 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)); > + 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 > + ); > + > + 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-> > > 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; > Keeping SymLoops in the root FILE seems kind of out of place. My idea here (and this was going to be chained with a bunch of improvements to the path walking logic, which is why I never got around to adding symlink support) was to add a nameidata(see Onyx code, or NetBSD's namei(9) manpage)-like structure, as you would in typical UNIX fashion. You would then do your whole path traversal on that structure, which would keep your path walking state, walked_symlinks, etc. > + > + 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); > + } > + > + 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 > > -- Pedro Falcato -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#92927): https://edk2.groups.io/g/devel/message/92927 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] -=-=-=-=-=-=-=-=-=-=-=-
