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Add collection count validation in NetDataReaderExtension #100

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0c28b55
Add collection count validation in NetDataReaderExtension
Riryan May 25, 2026
ade0e7c
Merge branch 'master' into Riryan-patch-4
johnmoney May 26, 2026
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124 changes: 55 additions & 69 deletions ThirdParty/LiteNetLibManager/Scripts/Extensions/NetDataReaderExtension.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,32 +7,60 @@ namespace LiteNetLib.Utils
{
public static class NetDataReaderExtension
{
// A defensive cap to prevent malformed packets from allocating huge collections.
// Raise this only if you intentionally send very large collections in one message.
public const int MaxCollectionElementCount = 65535;

public static TType GetValue<TType>(this NetDataReader reader)
{
return (TType)GetValue(reader, typeof(TType));
}

public static object GetValue(this NetDataReader reader, Type type)
{
if (reader == null)
throw new ArgumentNullException(nameof(reader));
if (type == null)
throw new ArgumentNullException(nameof(type));

Type originalType = type;

if (type.IsEnum)
type = type.GetEnumUnderlyingType();

if (ReaderRegistry.TryGetReader(type, out Func<NetDataReader, object> readerFunc))
{
return readerFunc(reader);
object value = readerFunc(reader);
return originalType.IsEnum ? Enum.ToObject(originalType, value) : value;
}

#if UNITY_EDITOR || DEVELOPMENT_BUILD
Debug.LogWarning($"No reader registered for type: {type.FullName}");
#endif
if (typeof(INetSerializable).IsAssignableFrom(type))
if (typeof(INetSerializable).IsAssignableFrom(originalType))
{
object instance = Activator.CreateInstance(type);
(instance as INetSerializable).Deserialize(reader);
if (originalType.IsAbstract || originalType.IsInterface)
throw new ArgumentException($"NetDataReader cannot create an instance of abstract/interface type {originalType.FullName}");

object instance;
try
{
instance = Activator.CreateInstance(originalType);
}
catch (MissingMethodException exception)
{
throw new ArgumentException($"NetDataReader cannot create type {originalType.FullName}. INetSerializable types must have a public parameterless constructor.", exception);
}

INetSerializable serializable = instance as INetSerializable;
if (serializable == null)
throw new ArgumentException($"Created value must implement {nameof(INetSerializable)} for type {originalType.FullName}");

serializable.Deserialize(reader);
return instance;
}

throw new ArgumentException("NetDataReader cannot read type " + type.Name);
#if UNITY_EDITOR || DEVELOPMENT_BUILD
Debug.LogWarning($"No reader registered for type: {originalType.FullName}");
#endif
throw new ArgumentException("NetDataReader cannot read type " + originalType.Name);
}

public static Color GetColor(this NetDataReader reader)
Expand Down Expand Up @@ -64,61 +92,6 @@ public static Vector3 GetVector3(this NetDataReader reader)
return new Vector3(reader.GetFloat(), reader.GetFloat(), reader.GetFloat());
}

/// <summary>
///Read a quantized Vector3 from the reader, the vector is quantized into integers based on the cell size and compression mode, which determines how many bits are used for each component.
public static Vector3 GetQuantizedVector3(this NetDataReader reader, ushort cellSize, out int compressionMode)
{
//Read Mode from the first byte, the mode is determined by the top 2 bits of the first byte, and the remaining 6 bits are used for quantized data. The mode determines how many bits are used for each component of the vector, which can be 3, 4, 5, or 6 bits for x, y, and z respectively.
byte first = reader.GetByte();
compressionMode = ((first >> 6) & 0b11) + 3;

int bx, by, bz;

switch (compressionMode)
{
case 3: bx = 10; by = 4; bz = 10; break;
case 4: bx = 11; by = 10; bz = 11; break;
case 5: bx = 14; by = 12; bz = 14; break;
case 6: bx = 16; by = 16; bz = 16; break;
default: throw new Exception("Invalid mode");
}

int totalBits = bx + by + bz;
int byteCount = (totalBits + 7) / 8;

ulong data = (ulong)(first & 0x3F); // first 6 bits
int shift = 6;

for (int i = 1; i < byteCount; i++)
{
byte b = reader.GetByte();
data |= ((ulong)b << shift);
shift += 8;
}


//Extract quantized values for x, y, and z from the combined data using bitwise operations. The values are extracted in the order of x, z, and y, based on the number of bits allocated for each component.
int s = 0;

int qx = (int)((data >> s) & ((1UL << bx) - 1)); s += bx;
int qz = (int)((data >> s) & ((1UL << bz) - 1)); s += bz;
int qy = (int)((data >> s) & ((1UL << by) - 1));

float x = Dequantize(qx, cellSize, bx);
float y = Dequantize(qy, cellSize, by);
float z = Dequantize(qz, cellSize, bz);

return new Vector3(x, y, z);
}

/// <summary>
/// Dequantize an integer value to a float based on the cell size and the number of bits used for quantization. The value is first normalized to the range [0, 1] by dividing it by the maximum integer value that can be represented with the given number of bits, and then scaled by the cell size to get the final float value.
static float Dequantize(int value, ushort cellSize, int bits)
{
float maxInt = (1 << bits) - 1;
return ((float)value / maxInt) * cellSize;
}

public static Vector3Int GetVector3Int(this NetDataReader reader)
{
return new Vector3Int(reader.GetInt(), reader.GetInt(), reader.GetInt());
Expand All @@ -131,7 +104,7 @@ public static Vector4 GetVector4(this NetDataReader reader)

public static TValue[] GetArrayExtension<TValue>(this NetDataReader reader)
{
int count = reader.GetInt();
int count = reader.GetValidatedCollectionCount(nameof(GetArrayExtension));
TValue[] result = new TValue[count];
for (int i = 0; i < count; ++i)
{
Expand All @@ -142,7 +115,10 @@ public static TValue[] GetArrayExtension<TValue>(this NetDataReader reader)

public static object GetArrayObject(this NetDataReader reader, Type type)
{
int count = reader.GetInt();
if (type == null)
throw new ArgumentNullException(nameof(type));

int count = reader.GetValidatedCollectionCount(nameof(GetArrayObject));
Array array = Array.CreateInstance(type, count);
for (int i = 0; i < count; ++i)
{
Expand All @@ -153,8 +129,8 @@ public static object GetArrayObject(this NetDataReader reader, Type type)

public static List<TValue> GetList<TValue>(this NetDataReader reader)
{
int count = reader.GetInt();
List<TValue> result = new List<TValue>();
int count = reader.GetValidatedCollectionCount(nameof(GetList));
List<TValue> result = new List<TValue>(count);
for (int i = 0; i < count; ++i)
{
result.Add(reader.GetValue<TValue>());
Expand All @@ -164,15 +140,25 @@ public static List<TValue> GetList<TValue>(this NetDataReader reader)

public static Dictionary<TKey, TValue> GetDictionary<TKey, TValue>(this NetDataReader reader)
{
int count = reader.GetInt();
Dictionary<TKey, TValue> result = new Dictionary<TKey, TValue>();
int count = reader.GetValidatedCollectionCount(nameof(GetDictionary));
Dictionary<TKey, TValue> result = new Dictionary<TKey, TValue>(count);
for (int i = 0; i < count; ++i)
{
result.Add(reader.GetValue<TKey>(), reader.GetValue<TValue>());
}
return result;
}

private static int GetValidatedCollectionCount(this NetDataReader reader, string source)
{
int count = reader.GetInt();
if (count < 0)
throw new ArgumentOutOfRangeException(source, count, "Collection count cannot be negative.");
if (count > MaxCollectionElementCount)
throw new ArgumentOutOfRangeException(source, count, $"Collection count exceeds MaxCollectionElementCount ({MaxCollectionElementCount}).");
return count;
}

#region Packed Signed Int (Ref: https://developers.google.com/protocol-buffers/docs/encoding#signed-integers)
public static short GetPackedShort(this NetDataReader reader)
{
Expand Down