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Diffstat (limited to 'src/md/inc/mdfileformat.h')
| -rw-r--r-- | src/md/inc/mdfileformat.h | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/src/md/inc/mdfileformat.h b/src/md/inc/mdfileformat.h new file mode 100644 index 0000000000..a86549323e --- /dev/null +++ b/src/md/inc/mdfileformat.h @@ -0,0 +1,269 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. +//***************************************************************************** +// MDFileFormat.h +// + +// +// This file contains a set of helpers to verify and read the file format. +// This code does not handle the paging of the data, or different types of +// I/O. See the StgTiggerStorage and StgIO code for this level of support. +// +//***************************************************************************** +#ifndef __MDFileFormat_h__ +#define __MDFileFormat_h__ + +//***************************************************************************** +// The signature ULONG is the first 4 bytes of the file format. The second +// signature string starts the header containing the stream list. It is used +// for an integrity check when reading the header in lieu of a more complicated +// system. +//***************************************************************************** +#define STORAGE_MAGIC_SIG 0x424A5342 // BSJB + + + +//***************************************************************************** +// These values get written to the signature at the front of the file. Changing +// these values should not be done lightly because all old files will no longer +// be supported. In a future revision if a format change is required, a +// backwards compatible migration path must be provided. +//***************************************************************************** + +#define FILE_VER_MAJOR 1 +#define FILE_VER_MINOR 1 + +// These are the last legitimate 0.x version macros. The file format has +// sinced move up to 1.x (see macros above). After COM+ 1.0/NT 5 RTM's, these +// macros should no longer be required or ever seen. +#define FILE_VER_MAJOR_v0 0 + +#define FILE_VER_MINOR_v0 19 + + +#define MAXSTREAMNAME 32 + +enum +{ + STGHDR_NORMAL = 0x00, // Normal default flags. + STGHDR_EXTRADATA = 0x01, // Additional data exists after header. +}; + + +//***************************************************************************** +// This is the formal signature area at the front of the file. This structure +// is not allowed to change, the shim depends on it staying the same size. +// Use the reserved pointer if it must extended. +//***************************************************************************** +struct STORAGESIGNATURE; +typedef STORAGESIGNATURE UNALIGNED * PSTORAGESIGNATURE; + +#include "pshpack1.h" +struct STORAGESIGNATURE +{ +METADATA_FIELDS_PROTECTION: + ULONG lSignature; // "Magic" signature. + USHORT iMajorVer; // Major file version. + USHORT iMinorVer; // Minor file version. + ULONG iExtraData; // Offset to next structure of information + ULONG iVersionString; // Length of version string +public: + BYTE pVersion[0]; // Version string + ULONG GetSignature() + { + return VAL32(lSignature); + } + void SetSignature(ULONG Signature) + { + lSignature = VAL32(Signature); + } + + USHORT GetMajorVer() + { + return VAL16(iMajorVer); + } + void SetMajorVer(USHORT MajorVer) + { + iMajorVer = VAL16(MajorVer); + } + + USHORT GetMinorVer() + { + return VAL16(iMinorVer); + } + void SetMinorVer(USHORT MinorVer) + { + iMinorVer = VAL16(MinorVer); + } + + ULONG GetExtraDataOffset() + { + return VAL32(iExtraData); + } + void SetExtraDataOffset(ULONG ExtraDataOffset) + { + iExtraData = VAL32(ExtraDataOffset); + } + + ULONG GetVersionStringLength() + { + return VAL32(iVersionString); + } + void SetVersionStringLength(ULONG VersionStringLength) + { + iVersionString = VAL32(VersionStringLength); + } +}; +#include "poppack.h" + + +//***************************************************************************** +// The header of the storage format. +//***************************************************************************** +struct STORAGEHEADER; +typedef STORAGEHEADER UNALIGNED * PSTORAGEHEADER; + +#include "pshpack1.h" +struct STORAGEHEADER +{ +METADATA_FIELDS_PROTECTION: + BYTE fFlags; // STGHDR_xxx flags. + BYTE pad; + USHORT iStreams; // How many streams are there. +public: + BYTE GetFlags() + { + return fFlags; + } + void SetFlags(BYTE flags) + { + fFlags = flags; + } + void AddFlags(BYTE flags) + { + fFlags |= flags; + } + + + USHORT GetiStreams() + { + return VAL16(iStreams); + } + void SetiStreams(USHORT iStreamsCount) + { + iStreams = VAL16(iStreamsCount); + } +}; +#include "poppack.h" + + +//***************************************************************************** +// Each stream is described by this struct, which includes the offset and size +// of the data. The name is stored in ANSI null terminated. +//***************************************************************************** +struct STORAGESTREAM; +typedef STORAGESTREAM UNALIGNED * PSTORAGESTREAM; + +#include "pshpack1.h" +struct STORAGESTREAM +{ +METADATA_FIELDS_PROTECTION: + ULONG iOffset; // Offset in file for this stream. + ULONG iSize; // Size of the file. + char rcName[MAXSTREAMNAME]; // Start of name, null terminated. +public: + // Returns pointer to the next stream. Doesn't validate the structure. + inline PSTORAGESTREAM NextStream() + { + int iLen = (int)(strlen(rcName) + 1); + iLen = ALIGN4BYTE(iLen); + return ((PSTORAGESTREAM) (((BYTE*)this) + (sizeof(ULONG) * 2) + iLen)); + } + // Returns pointer to the next stream. + // Returns NULL if the structure has invalid format. + inline PSTORAGESTREAM NextStream_Verify() + { + // Check existence of null-terminator in the name + if (memchr(rcName, 0, MAXSTREAMNAME) == NULL) + { + return NULL; + } + return NextStream(); + } + + inline ULONG GetStreamSize() + { + return (ULONG)(strlen(rcName) + 1 + (sizeof(STORAGESTREAM) - sizeof(rcName))); + } + + inline char* GetName() + { + return rcName; + } + inline LPCWSTR GetName(__inout_ecount (iMaxSize) LPWSTR szName, int iMaxSize) + { + VERIFY(::WszMultiByteToWideChar(CP_ACP, 0, rcName, -1, szName, iMaxSize)); + return (szName); + } + inline void SetName(LPCWSTR szName) + { + int size; + size = WszWideCharToMultiByte(CP_ACP, 0, szName, -1, rcName, MAXSTREAMNAME, 0, 0); + _ASSERTE(size > 0); + } + + ULONG GetSize() + { + return VAL32(iSize); + } + void SetSize(ULONG Size) + { + iSize = VAL32(Size); + } + + ULONG GetOffset() + { + return VAL32(iOffset); + } + void SetOffset(ULONG Offset) + { + iOffset = VAL32(Offset); + } +}; +#include "poppack.h" + + +class MDFormat +{ +public: +//***************************************************************************** +// Verify the signature at the front of the file to see what type it is. +//***************************************************************************** + static HRESULT VerifySignature( + PSTORAGESIGNATURE pSig, // The signature to check. + ULONG cbData); // Size of metadata. + +//***************************************************************************** +// Skip over the header and find the actual stream data. +// It doesn't perform any checks for buffer overflow - use GetFirstStream_Verify +// instead. +//***************************************************************************** + static PSTORAGESTREAM GetFirstStream(// Return pointer to the first stream. + PSTORAGEHEADER pHeader, // Return copy of header struct. + const void *pvMd); // Pointer to the full file. +//***************************************************************************** +// Skip over the header and find the actual stream data. Secure version of +// GetFirstStream method. +// The header is supposed to be verified by VerifySignature. +// +// Caller has to check available buffer size before using the first stream. +//***************************************************************************** + static PSTORAGESTREAM GetFirstStream_Verify(// Return pointer to the first stream. + PSTORAGEHEADER pHeader, // Return copy of header struct. + const void *pvMd, // Pointer to the full file. + ULONG *pcbMd); // [in, out] Size of pvMd buffer (we don't want to read behind it) + +}; + +#endif // __MDFileFormat_h__ |