/// <summary>
/// Calculates the length for the chunk parameter.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The length of the chunk. This method gets overridden by specialised SCTP parameters
/// that each have their own fields that determine the length.</returns>
public virtual ushort GetParameterLength(bool padded)
{
ushort len = (ushort)(SCTP_PARAMETER_HEADER_LENGTH
+ (ParameterValue == null ? 0 : ParameterValue.Length));
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Calculates the length for the chunk. Chunks are required
/// to be padded out to 4 byte boundaries. This method gets overridden
/// by specialised SCTP chunks that have their own fields that determine the length.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The length of the chunk.</returns>
public virtual ushort GetChunkLength(bool padded)
{
var len = (ushort)(SCTP_CHUNK_HEADER_LENGTH
+ (ChunkValue == null ? 0 : ChunkValue.Length));
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Calculates the length for DATA chunk.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The length of the chunk.</returns>
public override ushort GetChunkLength(bool padded)
{
ushort len = SCTP_CHUNK_HEADER_LENGTH + FIXED_PARAMETERS_LENGTH;
len += (ushort)(UserData != null ? UserData.Length : 0);
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Calculates the length for INIT and INIT ACK chunks.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The length of the chunk.</returns>
public override ushort GetChunkLength(bool padded)
{
var len = (ushort)(SCTP_CHUNK_HEADER_LENGTH +
FIXED_PARAMETERS_LENGTH +
GetVariableParametersLength(false));
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Calculates the length for the chunk.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The padded length of the chunk.</returns>
public override ushort GetChunkLength(bool padded)
{
ushort len = SCTP_CHUNK_HEADER_LENGTH;
if (ErrorCauses != null && ErrorCauses.Count > 0)
{
foreach (var cause in ErrorCauses)
{
len += cause.GetErrorCauseLength(padded);
}
}
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Gets the length of the optional and variable length parameters for this
/// INIT or INIT ACK chunk.
/// </summary>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The length of the optional and variable length parameters.</returns>
private ushort GetVariableParametersLength(bool padded)
{
int len = 0;
len += Addresses.Count(x => x.AddressFamily == AddressFamily.InterNetwork) *
(SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH + PARAMVAL_LENGTH_IPV4);
len += Addresses.Count(x => x.AddressFamily == AddressFamily.InterNetworkV6) *
(SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH + PARAMVAL_LENGTH_IPV6);
if (CookiePreservative > 0)
{
len += SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH +
PARAMVAL_LENGTH_COOKIE_PRESERVATIVE;
}
if (!string.IsNullOrEmpty(HostnameAddress))
{
len += SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH +
SctpPadding.PadTo4ByteBoundary(Encoding.UTF8.GetByteCount(HostnameAddress));
}
if (SupportedAddressTypes.Count > 0)
{
len += SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH +
SctpPadding.PadTo4ByteBoundary(SupportedAddressTypes.Count * 2);
}
if (StateCookie != null)
{
len += SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH +
SctpPadding.PadTo4ByteBoundary(StateCookie.Length);
}
foreach (var unrecognised in UnrecognizedPeerParameters)
{
len += SctpTlvChunkParameter.SCTP_PARAMETER_HEADER_LENGTH +
unrecognised.GetParameterLength(true);
}
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : (ushort)len);
}
public ushort GetErrorCauseLength(bool padded)
{
ushort len = (ushort)(4 + ((!string.IsNullOrEmpty(AdditionalInformation)) ? Encoding.UTF8.GetByteCount(AdditionalInformation) : 0));
return(padded ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
public ushort GetErrorCauseLength(bool padded)
{
ushort len = (ushort)(4 + ((NewAddressTLVs != null) ? NewAddressTLVs.Length : 0));
return(padded ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
public ushort GetErrorCauseLength(bool padded)
{
ushort len = (ushort)(4 + ((UnrecognizedParameters != null) ? UnrecognizedParameters.Length : 0));
return(padded ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
public ushort GetErrorCauseLength(bool padded)
{
ushort len = (ushort)(4 + ((MissingParameters != null) ? MissingParameters.Count * 2 : 0));
return(padded ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
/// <summary>
/// Extracts the padded length field from a serialised chunk buffer.
/// </summary>
/// <param name="buffer">The buffer holding the serialised chunk.</param>
/// <param name="posn">The start position of the serialised chunk.</param>
/// <param name="padded">If true the length field will be padded to a 4 byte boundary.</param>
/// <returns>The padded length of the serialised chunk.</returns>
public static uint GetChunkLengthFromHeader(byte[] buffer, int posn, bool padded)
{
ushort len = NetConvert.ParseUInt16(buffer, posn + 2);
return((padded) ? SctpPadding.PadTo4ByteBoundary(len) : len);
}
