/// <summary>
/// Creates an SCTP packet.
/// </summary>
/// <param name="sourcePort">The source port.</param>
/// <param name="destinationPort">The destination port.</param>
/// <param name="verificationTag">The verification tag.</param>
/// <param name="chunks">The packets chunks.</param>
/// <returns>An <see cref="SCTPPacket"/> instance.</returns>
public static SCTPPacket Create(ushort sourcePort, ushort destinationPort, uint verificationTag, params Chunk[] chunks)
{
SCTPPacket packet = new SCTPPacket();
packet.Header.SrcPort = sourcePort;
packet.Header.DstPort = destinationPort;
packet.Header.Chksum = 0;
packet.Header.VerTag = verificationTag;
if (chunks != null &&
chunks.Any())
{
packet.AddChunks(chunks);
packet.CalculateSize();
}
return(packet);
}
/// <summary>
/// Reads a packet from a given positin in a byte array.
/// </summary>
/// <param name="buffer">The byte array.</param>
/// <param name="offset">The position to start reading from.</param>
/// <param name="length">The number of bytes to read for.</param>
/// <returns>The <c>SCTP</c> packet.</returns>
public static SCTPPacket FromArray(byte[] buffer, int offset, int length, bool throwOnCRCFailure = false)
{
if (offset + 12 < length)
{
if (CheckCRC(buffer, offset, length) == false)
{
if (throwOnCRCFailure == true)
{
throw new Exception("CRC Check failed");
}
return(null);
}
SCTPPacket packet = new SCTPPacket();
int start = offset;
offset += packet.Header.FromArray(buffer, offset);
while (offset + 4 <= length)
{
Chunk chunk = Chunk.Create(buffer, offset, out int chunkLength);
if (chunk == null)
{
break;
}
packet.Chunks.Add(chunk);
offset += chunkLength;
}
packet.CalculateSize();
return(packet);
}
return(null);
}