private static unsafe void _Dump(NtfsAttributeListAttribute *from, DumpCallbackDelegate callback)
{
if (null == from)
{
throw new ArgumentNullException();
}
if (NtfsAttributeType.AttributeAttributeList != from->Header.AttributeType)
{
throw new ArgumentException();
}
IPartitionClusterData disposableData = null;
ListEntry * listBase = null;
uint listLength;
try {
if (from->Header.IsResident)
{
NtfsResidentAttribute *listAttribute = (NtfsResidentAttribute *)from;
listBase = (ListEntry *)((byte *)from + listAttribute->ValueOffset);
listLength = listAttribute->ValueLength;
}
else
{
NtfsNonResidentAttribute *listAttribute = (NtfsNonResidentAttribute *)from;
disposableData = listAttribute->GetData();
if (null == disposableData)
{
throw new ApplicationException();
}
listBase = (ListEntry *)disposableData.Data;
ulong candidateLength = listAttribute->DataSize;
if (uint.MaxValue < candidateLength)
{
throw new ApplicationException();
}
listLength = (uint)candidateLength;
}
if (null == listBase)
{
throw new ApplicationException();
}
uint offset = 0;
while (offset < listLength)
{
ListEntry *entry = (ListEntry *)((byte *)listBase + offset);
callback(entry);
offset += entry->EntryLength;
}
}
finally {
if (null != disposableData)
{
disposableData.Dispose();
}
}
}
public static void InsertHeadList(
ListEntry *ListHead,
ListEntry *Entry
)
{
ListEntry *flink;
flink = ListHead->Flink;
Entry->Flink = flink;
Entry->Blink = ListHead;
flink->Blink = Entry;
ListHead->Flink = Entry;
}
public static void InsertTailList(
ListEntry *ListHead,
ListEntry *Entry
)
{
ListEntry *blink;
blink = ListHead->Blink;
Entry->Flink = ListHead;
Entry->Blink = blink;
blink->Flink = Entry;
ListHead->Blink = Entry;
}
public static ListEntry *RemoveTailList(
ListEntry *ListHead
)
{
ListEntry *blink;
ListEntry *entry;
entry = ListHead->Blink;
blink = entry->Blink;
ListHead->Blink = blink;
blink->Flink = ListHead;
return(entry);
}
public static ListEntry *RemoveHeadList(
ListEntry *ListHead
)
{
ListEntry *flink;
ListEntry *entry;
entry = ListHead->Flink;
flink = entry->Flink;
ListHead->Flink = flink;
flink->Blink = ListHead;
return(entry);
}
public static bool RemoveEntryList(
ListEntry *Entry
)
{
ListEntry *blink;
ListEntry *flink;
flink = Entry->Flink;
blink = Entry->Blink;
blink->Flink = flink;
flink->Blink = blink;
return(flink == blink);
}
public static bool IsListEmpty(
ListEntry *ListHead
)
{
return(ListHead->Flink == ListHead->Blink);
}
public static void InitializeListHead(
ListEntry *ListHead
)
{
ListHead->Flink = ListHead->Blink = ListHead;
}
/// <summary>The caller enumerating entries might be interested in the content of
/// the currently scanned entry. This might be either for additional filtering at
/// attribute level (including attribute name) or for full attribute data processing.
/// </summary>
/// <param name="entry">The scanned list entry of interest. Should a single
/// attribute span several entries, this one is guaranteed to be the first one for the
/// attribute.</param>
/// <param name="remainingBytesInList">Number of bytes remaining in list, relatively to the
/// entry address.</param>
/// <param name="entryReferencedAttributeHandler">The callback that will be invoked
/// with the referenced attribute with or without full attribute data depending on
/// the value of <paramref name="dataIncluded"/></param>
/// <param name="dataIncluded"></param>
/// <returns>true if caller should continue process data, false if it should stop.</returns>
private static unsafe bool HandleEntryReferencedAttribute(ListEntry *entry, uint remainingBytesInList,
EntryListReferencedAttributeHandlerDelegate entryReferencedAttributeHandler,
bool dataIncluded)
{
ushort currentAttributeNumber = entry->AttributeNumber;
NtfsAttributeType currentAttributeType = entry->AttributeType;
byte * baseAddress = (byte *)entry;
uint relativeOffset = 0;
// The last callback invocation decided it needs some more data before deciding
// what to do.
IPartitionClusterData clusterData = null;
NtfsPartition currentPartition = NtfsPartition.Current;
using (PartitionDataDisposableBatch batch = PartitionDataDisposableBatch.CreateNew()) {
while (true)
{
ListEntry * scannedEntry = (ListEntry *)baseAddress;
ulong mainFileReferenceNumber = entry->FileReferenceNumber;
List <ulong> entries = new List <ulong>();
Stream dataStream = null;
if (dataIncluded)
{
// Read each record and prepare for data retrieval.
while (true)
{
entries.Add(scannedEntry->FileReferenceNumber);
relativeOffset += scannedEntry->EntryLength;
if (relativeOffset >= remainingBytesInList)
{
// Take care not to go further than the end of the list.
break;
}
scannedEntry = (ListEntry *)(baseAddress + relativeOffset);
if ((currentAttributeNumber != scannedEntry->AttributeNumber) ||
(currentAttributeType != scannedEntry->AttributeType))
{
break;
}
}
dataStream = new MultiRecordAttributeDataStream(entries);
}
// Retrieve attribute itself.
NtfsFileRecord *mainFileRecord =
currentPartition.GetFileRecord(mainFileReferenceNumber, ref clusterData);
if (null == mainFileRecord)
{
throw new ApplicationException();
}
NtfsAttribute *retrievedAttribute =
(NtfsAttribute *)((byte *)mainFileRecord + mainFileRecord->AttributesOffset);
// Invoke callback.
bool retry;
if (!entryReferencedAttributeHandler(retrievedAttribute, dataStream, out retry))
{
// After attribute has been processed, it has been decided no other list
// entry should be performed.
return(false);
}
if (!retry)
{
// After attribute has been processed, it has been decided that no
// additional data from this attribute is required. However the enumeration
// of other list entries should continue.
return(true);
}
if (dataIncluded)
{
throw new InvalidOperationException();
}
// Attribute has been processed, however not enough data was available for a
// final decision. We loop and include all data now.
dataIncluded = true;
}
}
}
/// <summary></summary>
/// <param name="from">The NtfsAttributeListAttribute to be used for enumeration.</param>
/// <param name="searchedAttributeType">The type of the searched attribute or
/// <see cref="NtfsAttributeType.Any"/> if the caller is interested in all kinds of
/// attributes.</param>
/// <param name="listEntryHandler">A callback to be invoked on each entry matching
/// the attribute type selection criteria.</param>
/// <remarks>WARNING : This might seems counterintuitive to have this method at a class
/// level instead of making it an instance one. This is because we absolutely don't want
/// it to be invoked on an object reference that is subject to being moved in memory by
/// the GC. Forcing the caller to provide a pointer makes her responsible for enforcing
/// the pinning requirements.</remarks>
internal static unsafe void EnumerateEntries(NtfsAttribute *from,
NtfsAttributeType searchedAttributeType, EntryEnumeratorCallbackDelegate listEntryHandler)
{
if (null == from)
{
throw new ArgumentNullException();
}
if (NtfsAttributeType.AttributeAttributeList != from->AttributeType)
{
throw new ArgumentException();
}
IPartitionClusterData listAttributeData = null;
// Address of first ListeEntry item for this attribute.
ListEntry *listBase = null;
uint listLength;
try {
if (from->IsResident)
{
NtfsResidentAttribute *listAttribute = (NtfsResidentAttribute *)from;
listBase = (ListEntry *)((byte *)from + listAttribute->ValueOffset);
listLength = listAttribute->ValueLength;
}
else
{
NtfsNonResidentAttribute *listAttribute = (NtfsNonResidentAttribute *)from;
listAttributeData = listAttribute->GetData();
if (null == listAttributeData)
{
throw new ApplicationException();
}
listBase = (ListEntry *)listAttributeData.Data;
ulong candidateLength = listAttribute->DataSize;
if (uint.MaxValue < candidateLength)
{
throw new ApplicationException();
}
listLength = (uint)candidateLength;
}
if (null == listBase)
{
throw new ApplicationException();
}
NtfsAttributeType currentAttributeType = NtfsAttributeType.Any;
ushort currentAttributeNumber = ushort.MaxValue;
ListEntry * scannedEntry;
for (uint offset = 0; offset < listLength; offset += scannedEntry->EntryLength)
{
scannedEntry = (ListEntry *)((byte *)listBase + offset);
if ((currentAttributeNumber == scannedEntry->AttributeNumber) &&
(currentAttributeType == scannedEntry->AttributeType))
{
// The entry is a continuation of the previous one. Ignore it. It should
// have been processed by a previous loop if required.
continue;
}
currentAttributeNumber = scannedEntry->AttributeNumber;
currentAttributeType = scannedEntry->AttributeType;
if ((NtfsAttributeType.Any != searchedAttributeType) &&
(scannedEntry->AttributeType != searchedAttributeType))
{
// This entry doesn't match the search criteria on attribute type.
continue;
}
EntryListReferencedAttributeHandlerDelegate attributeDataHandler;
bool includeData;
if (!listEntryHandler(scannedEntry, out attributeDataHandler, out includeData))
{
// The callback doesn't wish to continue with other list entries.
return;
}
if (null == attributeDataHandler)
{
// The callback doesn't wish to retrieve the attribute itself for the
// currently scanned entry.
continue;
}
// The last callback invocation decided it needs some data from the attribute
// itself before deciding what to do.
if (!HandleEntryReferencedAttribute(scannedEntry, listLength - offset,
attributeDataHandler, includeData))
{
return;
}
}
}
finally {
if (null != listAttributeData)
{
listAttributeData.Dispose();
}
}
}
