/// <summary>
/// Reads a record from the file system.
/// </summary>
/// <param name="item">The item to read the data into.</param>
/// <param name="volumeIndex">The index of the volume the file resides on.</param>
/// <param name="lad">The long allocation descriptor of the file.</param>
/// <param name="numRecurseAllowed">The number of recursions allowed before the method fails.</param>
/// <returns>Returns true if the item and all sub items were read correctly.</returns>
private bool ReadRecord(UdfRecord item, int volumeIndex, LongAllocationDescriptor lad, int numRecurseAllowed)
{
if (numRecurseAllowed-- == 0)
{
return(false);
}
LogicalVolume vol = this.LogicalVolumes[volumeIndex];
Partition partition = this.Partitions[vol.PartitionMaps[lad.Location.PartitionReference].PartitionIndex];
int key = lad.Location.Position;
if (partition.Map.ContainsKey(key))
{
// Item already in the map, just look it up instead of reading it from the image.
item.VolumeIndex = partition.Map[key].VolumeIndex;
item.PartitionIndex = partition.Map[key].PartitionIndex;
item.Extents = partition.Map[key].Extents;
item._size = partition.Map[key]._size;
item.Key = key;
}
else
{
item.VolumeIndex = volumeIndex;
item.PartitionIndex = vol.PartitionMaps[lad.Location.PartitionReference].PartitionIndex;
item.Key = key;
if (!partition.Map.Set(key, item) || !this.ReadRecordData(item, volumeIndex, lad, numRecurseAllowed))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Reads the file and directory structure from the image.
/// </summary>
/// <returns>Returns true if the file system is valid.</returns>
private bool ReadFileStructure()
{
foreach (var volume in this.LogicalVolumes)
{
// Ensure the volume and parittion are valid.
if (!this.ValidateVolumePartition(volume))
{
return(false);
}
int volIndex = this.LogicalVolumes.IndexOf(volume);
LongAllocationDescriptor nextExtent = volume.FileSetLocation;
if (nextExtent.Length < VirtualSectorSize)
{
return(false);
}
byte[] buffer = new byte[nextExtent.Length];
this.ReadData(volIndex, nextExtent, buffer);
VolumeTag tag = new VolumeTag();
tag.Parse(0, buffer, buffer.Length);
if (tag.Identifier != (int)VolumeDescriptorType.FileSet)
{
return(false);
}
UdfFileSet fs = new UdfFileSet();
fs.RecordingTime.Parse(16, buffer);
fs.RootDirICB.Parse(400, buffer);
volume.FileSet = fs;
if (!this.ReadRecord(this.RootDirectory as UdfRecord, volIndex, fs.RootDirICB, MaxRecurseLevels))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Reads data from the stream.
/// </summary>
/// <param name="volumeIndex">The volume index of the data.</param>
/// <param name="lad">The long allocation descriptor of the data.</param>
/// <param name="buffer">The buffer to contain the data.</param>
/// <returns>Returns true if the data was read successfully.</returns>
private bool ReadData(int volumeIndex, LongAllocationDescriptor lad, byte[] buffer)
{
return(this.ReadData(volumeIndex, lad.Location.PartitionReference, lad.Location.Position, lad.Length, buffer));
}
/// <summary>
/// Reads the data from the image for a record.
/// </summary>
/// <param name="item">The item to read the data into.</param>
/// <param name="volumeIndex">The index of the volume the file resides on.</param>
/// <param name="lad">The long allocation descriptor of the file.</param>
/// <param name="numRecurseAllowed">The number of recursions allowed before the method fails.</param>
/// <returns>Returns true if the record was read successfully.</returns>
private bool ReadRecordData(UdfRecord item, int volumeIndex, LongAllocationDescriptor lad, int numRecurseAllowed)
{
if (this.itemCount > MaxItems)
{
return(false);
}
LogicalVolume volume = this.LogicalVolumes[volumeIndex];
if (lad.Length != volume.BlockSize)
{
return(false);
}
// Read the record.
int size = lad.Length;
byte[] buffer = new byte[size];
if (!this.ReadData(volumeIndex, lad, buffer))
{
return(false);
}
// Validate the tag is a file.
VolumeTag tag = new VolumeTag();
tag.Parse(0, buffer, size);
if (tag.Identifier != (short)VolumeDescriptorType.File)
{
return(false);
}
// Validate the IcbTage indicates file or directory.
item.IcbTag.Parse(16, buffer);
if (item.IcbTag.FileType != IcbFileType.Directory && item.IcbTag.FileType != IcbFileType.File)
{
return(false);
}
item.Parse(buffer);
int extendedAttrLen = UdfHelper.Get32(168, buffer);
int allocDescriptorsLen = UdfHelper.Get32(172, buffer);
if ((extendedAttrLen & 3) != 0)
{
return(false);
}
int position = 176;
if (extendedAttrLen > size - position)
{
return(false);
}
position += extendedAttrLen;
IcbDescriptorType desctType = item.IcbTag.DescriptorType;
if (allocDescriptorsLen > size - position)
{
return(false);
}
if (desctType == IcbDescriptorType.Inline)
{
// If the file data is inline, read it in now since we have it.
item.IsInline = true;
item.InlineData = UdfHelper.Readbytes(position, buffer, allocDescriptorsLen);
}
else
{
// Otherwise read the information about where the file is located for later.
item.IsInline = false;
item.InlineData = new byte[0];
if ((desctType != IcbDescriptorType.Short) && (desctType != IcbDescriptorType.Long))
{
return(false);
}
for (int index = 0; index < allocDescriptorsLen;)
{
FileExtent extent = new FileExtent();
if (desctType == IcbDescriptorType.Short)
{
if (index + 8 > allocDescriptorsLen)
{
return(false);
}
ShortAllocationDescriptor sad = new ShortAllocationDescriptor();
sad.Parse(position + index, buffer);
extent.Position = sad.Position;
extent.Length = sad.Length;
extent.PartitionReference = lad.Location.PartitionReference;
index += 8;
}
else
{
if (index + 16 > allocDescriptorsLen)
{
return(false);
}
LongAllocationDescriptor ladNew = new LongAllocationDescriptor();
ladNew.Parse(position + index, buffer);
extent.Position = ladNew.Location.Position;
extent.PartitionReference = ladNew.Location.PartitionReference;
extent.Length = ladNew.Length;
index += 16;
}
item.Extents.Add(extent);
}
}
if (item.IcbTag.IsDirectory)
{
if (!item.CheckChunkSizes() || !this.CheckItemExtents(volumeIndex, item))
{
return(false);
}
buffer = new byte[0];
if (!this.ReadFromFile(volumeIndex, ref item, ref buffer))
{
return(false);
}
item._size = 0;
item.Extents.Clear();
size = buffer.Length;
int processedTotal = 0;
int processedCur = -1;
while (processedTotal < size || processedCur == 0)
{
UdfFileInformation fileId = new UdfFileInformation();
fileId.Parse(processedTotal, buffer, (size - processedTotal), ref processedCur);
if (!fileId.IsItLinkParent)
{
// Recursively read the contentst of the drirectory
UdfRecord fileItem = new UdfRecord();
fileItem.Id = fileId.Identifier;
if (fileItem.Id.Data != null)
{
this.fileNameLengthTotal += fileItem.Id.Data.Length;
}
if (this.fileNameLengthTotal > MaxFileNameLength)
{
return(false);
}
fileItem._Parent = item;
item.Subitems.Add(fileItem);
if (item.Subitems.Count > MaxFiles)
{
return(false);
}
this.ReadRecord(fileItem, volumeIndex, fileId.Icb, numRecurseAllowed);
}
processedTotal += processedCur;
}
}
else
{
if (item.Extents.Count > MaxExtents - this.numExtents)
{
return(false);
}
this.numExtents += item.Extents.Count;
if (item.InlineData.Length > MaxInlineExtentsSize - this.inlineExtentsSize)
{
return(false);
}
this.inlineExtentsSize += item.InlineData.Length;
}
this.itemCount++;
return(true);
}
/// <summary>
/// Reads the data from the image for a record.
/// </summary>
/// <param name="item">The item to read the data into.</param>
/// <param name="volumeIndex">The index of the volume the file resides on.</param>
/// <param name="lad">The long allocation descriptor of the file.</param>
/// <param name="numRecurseAllowed">The number of recursions allowed before the method fails.</param>
/// <returns>Returns true if the record was read successfully.</returns>
private bool ReadRecordData(UdfRecord item, int volumeIndex, LongAllocationDescriptor lad, int numRecurseAllowed)
{
if (this.itemCount > MaxItems)
{
return false;
}
LogicalVolume volume = this.LogicalVolumes[volumeIndex];
if (lad.Length != volume.BlockSize)
{
return false;
}
// Read the record.
int size = lad.Length;
byte[] buffer = new byte[size];
if (!this.ReadData(volumeIndex, lad, buffer))
{
return false;
}
// Validate the tag is a file.
VolumeTag tag = new VolumeTag();
tag.Parse(0, buffer, size);
if (tag.Identifier != (short)VolumeDescriptorType.File)
{
return false;
}
// Validate the IcbTage indicates file or directory.
item.IcbTag.Parse(16, buffer);
if (item.IcbTag.FileType != IcbFileType.Directory && item.IcbTag.FileType != IcbFileType.File)
{
return false;
}
item.Parse(buffer);
int extendedAttrLen = UdfHelper.Get32(168, buffer);
int allocDescriptorsLen = UdfHelper.Get32(172, buffer);
if ((extendedAttrLen & 3) != 0)
{
return false;
}
int position = 176;
if (extendedAttrLen > size - position)
{
return false;
}
position += extendedAttrLen;
IcbDescriptorType desctType = item.IcbTag.DescriptorType;
if (allocDescriptorsLen > size - position)
{
return false;
}
if (desctType == IcbDescriptorType.Inline)
{
// If the file data is inline, read it in now since we have it.
item.IsInline = true;
item.InlineData = UdfHelper.Readbytes(position, buffer, allocDescriptorsLen);
}
else
{
// Otherwise read the information about where the file is located for later.
item.IsInline = false;
item.InlineData = new byte[0];
if ((desctType != IcbDescriptorType.Short) && (desctType != IcbDescriptorType.Long))
{
return false;
}
for (int index = 0; index < allocDescriptorsLen;)
{
FileExtent extent = new FileExtent();
if (desctType == IcbDescriptorType.Short)
{
if (index + 8 > allocDescriptorsLen)
{
return false;
}
ShortAllocationDescriptor sad = new ShortAllocationDescriptor();
sad.Parse(position + index, buffer);
extent.Position = sad.Position;
extent.Length = sad.Length;
extent.PartitionReference = lad.Location.PartitionReference;
index += 8;
}
else
{
if (index + 16 > allocDescriptorsLen)
{
return false;
}
LongAllocationDescriptor ladNew = new LongAllocationDescriptor();
ladNew.Parse(position + index, buffer);
extent.Position = ladNew.Location.Position;
extent.PartitionReference = ladNew.Location.PartitionReference;
extent.Length = ladNew.Length;
index += 16;
}
item.Extents.Add(extent);
}
}
if (item.IcbTag.IsDirectory)
{
if (!item.CheckChunkSizes() || !this.CheckItemExtents(volumeIndex, item))
{
return false;
}
buffer = new byte[0];
if (!this.ReadFromFile(volumeIndex, ref item, ref buffer))
{
return false;
}
item._size = 0;
item.Extents.Clear();
size = buffer.Length;
int processedTotal = 0;
int processedCur = -1;
while (processedTotal < size || processedCur == 0)
{
UdfFileInformation fileId = new UdfFileInformation();
fileId.Parse(processedTotal, buffer, (size - processedTotal), ref processedCur);
if (!fileId.IsItLinkParent)
{
// Recursively read the contentst of the drirectory
UdfRecord fileItem = new UdfRecord();
fileItem.Id = fileId.Identifier;
if (fileItem.Id.Data != null)
{
this.fileNameLengthTotal += fileItem.Id.Data.Length;
}
if (this.fileNameLengthTotal > MaxFileNameLength)
{
return false;
}
fileItem._Parent = item;
item.Subitems.Add(fileItem);
if (item.Subitems.Count > MaxFiles)
{
return false;
}
this.ReadRecord(fileItem, volumeIndex, fileId.Icb, numRecurseAllowed);
}
processedTotal += processedCur;
}
}
else
{
if (item.Extents.Count > MaxExtents - this.numExtents)
{
return false;
}
this.numExtents += item.Extents.Count;
if (item.InlineData.Length > MaxInlineExtentsSize - this.inlineExtentsSize)
{
return false;
}
this.inlineExtentsSize += item.InlineData.Length;
}
this.itemCount++;
return true;
}
/// <summary>
/// Reads a record from the file system.
/// </summary>
/// <param name="item">The item to read the data into.</param>
/// <param name="volumeIndex">The index of the volume the file resides on.</param>
/// <param name="lad">The long allocation descriptor of the file.</param>
/// <param name="numRecurseAllowed">The number of recursions allowed before the method fails.</param>
/// <returns>Returns true if the item and all sub items were read correctly.</returns>
private bool ReadRecord(UdfRecord item, int volumeIndex, LongAllocationDescriptor lad, int numRecurseAllowed)
{
if (numRecurseAllowed-- == 0)
{
return false;
}
LogicalVolume vol = this.LogicalVolumes[volumeIndex];
Partition partition = this.Partitions[vol.PartitionMaps[lad.Location.PartitionReference].PartitionIndex];
int key = lad.Location.Position;
if (partition.Map.ContainsKey(key))
{
// Item already in the map, just look it up instead of reading it from the image.
item.VolumeIndex = partition.Map[key].VolumeIndex;
item.PartitionIndex = partition.Map[key].PartitionIndex;
item.Extents = partition.Map[key].Extents;
item._size = partition.Map[key]._size;
item.Key = key;
}
else
{
item.VolumeIndex = volumeIndex;
item.PartitionIndex = vol.PartitionMaps[lad.Location.PartitionReference].PartitionIndex;
item.Key = key;
if (!partition.Map.Set(key, item) || !this.ReadRecordData(item, volumeIndex, lad, numRecurseAllowed))
{
return false;
}
}
return true;
}
/// <summary>
/// Reads data from the stream.
/// </summary>
/// <param name="volumeIndex">The volume index of the data.</param>
/// <param name="lad">The long allocation descriptor of the data.</param>
/// <param name="buffer">The buffer to contain the data.</param>
/// <returns>Returns true if the data was read successfully.</returns>
private bool ReadData(int volumeIndex, LongAllocationDescriptor lad, byte[] buffer)
{
return this.ReadData(volumeIndex, lad.Location.PartitionReference, lad.Location.Position, lad.Length, buffer);
}
