예제 #1
0
        private void ReadHeaders()
        {
            long pos = _footer.DataOffset;

            while (pos != -1)
            {
                _fileStream.Position = pos;
                Header hdr = Header.FromStream(_fileStream);
                if (hdr.Cookie == DynamicHeader.HeaderCookie)
                {
                    _fileStream.Position = pos;
                    _dynamicHeader       = DynamicHeader.FromStream(_fileStream);
                    if (!_dynamicHeader.IsValid())
                    {
                        throw new IOException("Invalid Dynamic Disc Header");
                    }
                }

                pos = hdr.DataOffset;
            }
        }
예제 #2
0
        private void CheckDynamicHeader()
        {
            long lastHeaderEnd = _footer.DataOffset + 512;
            long pos           = _footer.DataOffset;

            while (pos != -1)
            {
                if ((pos % 512) != 0)
                {
                    ReportError("DynHeader: Unaligned header @{0}", pos);
                }

                _fileStream.Position = pos;
                Header hdr = Header.FromStream(_fileStream);

                if (hdr.Cookie == DynamicHeader.HeaderCookie)
                {
                    if (_dynamicHeader != null)
                    {
                        ReportError("DynHeader: Duplicate dynamic header found");
                    }

                    _fileStream.Position = pos;
                    _dynamicHeader       = DynamicHeader.FromStream(_fileStream);

                    if (pos + 1024 > lastHeaderEnd)
                    {
                        lastHeaderEnd = pos + 1024;
                    }
                }
                else
                {
                    ReportWarning("DynHeader: Undocumented header found, with cookie '" + hdr.Cookie + "'");

                    if (pos + 512 > lastHeaderEnd)
                    {
                        lastHeaderEnd = pos + 1024;
                    }
                }

                pos = hdr.DataOffset;
            }

            if (_dynamicHeader == null)
            {
                ReportError("DynHeader: No dynamic header found");
                return;
            }

            if (_dynamicHeader.TableOffset < lastHeaderEnd)
            {
                ReportError("DynHeader: BAT offset is before last header");
            }

            if ((_dynamicHeader.TableOffset % 512) != 0)
            {
                ReportError("DynHeader: BAT offset is not sector aligned");
            }

            if (_dynamicHeader.HeaderVersion != 0x00010000)
            {
                ReportError("DynHeader: Unrecognized header version");
            }

            if (_dynamicHeader.MaxTableEntries != Utilities.Ceil(_footer.CurrentSize, _dynamicHeader.BlockSize))
            {
                ReportError("DynHeader: Max table entries is invalid");
            }

            if ((_dynamicHeader.BlockSize != Sizes.OneMiB * 2) && (_dynamicHeader.BlockSize != Sizes.OneKiB * 512))
            {
                ReportWarning("DynHeader: Using non-standard block size '" + _dynamicHeader.BlockSize + "'");
            }

            if (!Utilities.IsPowerOfTwo(_dynamicHeader.BlockSize))
            {
                ReportError("DynHeader: Block size is not a power of 2");
            }

            if (!_dynamicHeader.IsChecksumValid())
            {
                ReportError("DynHeader: Invalid checksum");
            }

            if (_footer.DiskType == FileType.Dynamic && _dynamicHeader.ParentUniqueId != Guid.Empty)
            {
                ReportWarning("DynHeader: Parent Id is not null for dynamic disk");
            }
            else if (_footer.DiskType == FileType.Differencing && _dynamicHeader.ParentUniqueId == Guid.Empty)
            {
                ReportError("DynHeader: Parent Id is null for differencing disk");
            }

            if (_footer.DiskType == FileType.Differencing && _dynamicHeader.ParentTimestamp > DateTime.UtcNow)
            {
                ReportWarning("DynHeader: Parent timestamp is greater than current time");
            }
        }