public static int ReadFragmentHeader(byte[] packetBuffer, int offset, int bufferLength, int maxFragments, int fragmentSize, out int fragmentID, out int numFragments, out int fragmentBytes, out ushort sequence, out ushort ack, out uint ackBits, out byte channelID)
{
if (bufferLength < 6)
{
throw new FormatException("Buffer too small for packet header");
}
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byte b = byteArrayReaderWriter.ReadByte();
if ((b & 1) != 1)
{
throw new FormatException("Packet header indicates non-fragment packet");
}
channelID = byteArrayReaderWriter.ReadByte();
sequence = byteArrayReaderWriter.ReadUInt16();
fragmentID = byteArrayReaderWriter.ReadByte();
numFragments = byteArrayReaderWriter.ReadByte() + 1;
if (numFragments > maxFragments)
{
throw new FormatException("Packet header indicates fragments outside of max range");
}
if (fragmentID >= numFragments)
{
throw new FormatException("Packet header indicates fragment ID outside of fragment count");
}
fragmentBytes = bufferLength - 6;
ushort sequence2 = 0;
ushort ack2 = 0;
uint ackBits2 = 0u;
byte channelID2 = 0;
if (fragmentID == 0)
{
int num = ReadPacketHeader(packetBuffer, 6, bufferLength, out channelID2, out sequence2, out ack2, out ackBits2);
if (sequence2 != sequence)
{
throw new FormatException("Bad packet sequence in fragment");
}
fragmentBytes = bufferLength - num - 6;
}
ack = ack2;
ackBits = ackBits2;
if (fragmentBytes > fragmentSize)
{
throw new FormatException("Fragment bytes remaining > indicated fragment size");
}
if (fragmentID != numFragments - 1 && fragmentBytes != fragmentSize)
{
throw new FormatException("Fragment size invalid");
}
return((int)byteArrayReaderWriter.ReadPosition - offset);
}
}
public static int ReadPacketHeader(byte[] packetBuffer, int offset, int bufferLength, out byte channelID, out ushort sequence, out ushort ack, out uint ackBits)
{
if (bufferLength < 4)
{
throw new FormatException("Buffer too small for packet header");
}
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byteArrayReaderWriter.SeekRead(offset);
byte b = byteArrayReaderWriter.ReadByte();
if ((b & 1) != 0)
{
throw new InvalidOperationException("Header does not indicate regular packet");
}
channelID = byteArrayReaderWriter.ReadByte();
if ((b & 0x80) == 0)
{
sequence = byteArrayReaderWriter.ReadUInt16();
}
else
{
sequence = 0;
}
if ((b & 0x20) != 0)
{
if (bufferLength < 3)
{
throw new FormatException("Buffer too small for packet header");
}
byte b2 = byteArrayReaderWriter.ReadByte();
ack = (ushort)(sequence - b2);
}
else
{
if (bufferLength < 4)
{
throw new FormatException("Buffer too small for packet header");
}
ack = byteArrayReaderWriter.ReadUInt16();
}
int num = 0;
for (int i = 0; i <= 4; i++)
{
if ((b & (1 << i)) != 0)
{
num++;
}
}
if (bufferLength < bufferLength - byteArrayReaderWriter.ReadPosition + num)
{
throw new FormatException("Buffer too small for packet header");
}
ackBits = uint.MaxValue;
if ((b & 2) != 0)
{
ackBits &= 4294967040u;
ackBits |= byteArrayReaderWriter.ReadByte();
}
if ((b & 4) != 0)
{
ackBits &= 4294902015u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 8);
}
if ((b & 8) != 0)
{
ackBits &= 4278255615u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 16);
}
if ((b & 0x10) != 0)
{
ackBits &= 16777215u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 24);
}
return((int)byteArrayReaderWriter.ReadPosition - offset);
}
}