/// <summary>
/// Writes the layer to the buffer.
/// </summary>
/// <param name="buffer">The buffer to write the layer to.</param>
/// <param name="offset">The offset in the buffer to start writing the layer at.</param>
/// <param name="payloadLength">The length of the layer's payload (the number of bytes after the layer in the packet).</param>
/// <param name="previousLayer">The layer that comes before this layer. null if this is the first layer.</param>
/// <param name="nextLayer">The layer that comes after this layer. null if this is the last layer.</param>
public override void Write(byte[] buffer, int offset, int payloadLength, ILayer previousLayer, ILayer nextLayer)
{
IpV4Protocol?nextLayerProtocol = null;
if (nextLayer != null)
{
IIpNextLayer ipNextLayer = nextLayer as IIpNextLayer;
if (ipNextLayer != null)
{
nextLayerProtocol = ipNextLayer.PreviousLayerProtocol;
}
}
if (nextLayer != null && ExtensionHeaders.LastHeader == IpV4Protocol.EncapsulatingSecurityPayload)
{
throw new ArgumentException("Cannot have a layer after IpV6Layer with EncapsulatingSecurityPayload extension header.", "nextLayer");
}
if (payloadLength + ExtensionHeaders.BytesLength > ushort.MaxValue)
{
throw new ArgumentOutOfRangeException("payloadLength", payloadLength,
"Consider the extension headers, this must be no more than " +
(ushort.MaxValue - ExtensionHeaders.BytesLength));
}
IpV6Datagram.WriteHeader(buffer, offset,
TrafficClass, FlowLabel, (ushort)(payloadLength + ExtensionHeaders.BytesLength), NextHeader, nextLayerProtocol, HopLimit, Source, CurrentDestination, ExtensionHeaders);
}
/// <summary>
/// Writes the layer to the buffer.
/// </summary>
/// <param name="buffer">The buffer to write the layer to.</param>
/// <param name="offset">The offset in the buffer to start writing the layer at.</param>
/// <param name="payloadLength">The length of the layer's payload (the number of bytes after the layer in the packet).</param>
/// <param name="previousLayer">The layer that comes before this layer. null if this is the first layer.</param>
/// <param name="nextLayer">The layer that comes after this layer. null if this is the last layer.</param>
public override void Write(byte[] buffer, int offset, int payloadLength, ILayer previousLayer, ILayer nextLayer)
{
IpV4Protocol protocol;
if (Protocol == null)
{
if (nextLayer == null)
{
throw new ArgumentException("Can't determine protocol automatically from next layer because there is no next layer");
}
IIpNextLayer ipNextLayer = nextLayer as IIpNextLayer;
if (ipNextLayer == null)
{
throw new ArgumentException("Can't determine protocol automatically from next layer (" + nextLayer.GetType() + ")");
}
protocol = ipNextLayer.PreviousLayerProtocol;
}
else
{
protocol = Protocol.Value;
}
IpV4Datagram.WriteHeader(buffer, offset,
TypeOfService, Identification, Fragmentation,
Ttl, protocol, HeaderChecksum,
Source, CurrentDestination,
Options, payloadLength);
}
