/// <summary>
/// Look for the innermost payload. This method is useful because
/// while some packets are LinuxSSL->IpPacket or
/// EthernetPacket->IpPacket, there are some packets that are
/// EthernetPacket->PPPoEPacket->PPPPacket->IpPacket, and for these cases
/// we really want to get to the IpPacket
/// </summary>
/// <returns>
/// A <see cref="Packet"/>
/// </returns>
public static Packet GetInnerPayload(InternetLinkLayerPacket packet)
{
// is this an ethernet packet?
if (packet is EthernetPacket)
{
log.Debug("packet is EthernetPacket");
var thePayload = packet.PayloadPacket;
// is this packets payload a PPPoEPacket? If so,
// the PPPoEPacket payload should be a PPPPacket and we want
// the payload of the PPPPpacket
if (thePayload is PPPoEPacket)
{
log.Debug("thePayload is PPPoEPacket");
return(thePayload.PayloadPacket.PayloadPacket);
}
return(thePayload);
}
else
{
log.Debug("else");
return(packet.PayloadPacket);
}
}
/// <summary>
/// Returns the encapsulated ARPPacket of the Packet p or null if
/// there is no encapsulated packet
/// </summary>
/// <param name="p">
/// A <see cref="Packet"/>
/// </param>
/// <returns>
/// A <see cref="ARPPacket"/>
/// </returns>
public static ARPPacket GetEncapsulated(Packet p)
{
if (p is InternetLinkLayerPacket)
{
var payload = InternetLinkLayerPacket.GetInnerPayload((InternetLinkLayerPacket)p);
if (payload is ARPPacket)
{
return((ARPPacket)payload);
}
}
return(null);
}
/// <summary>
/// Returns the IpPacket inside of the Packet p or null if
/// there is no encapsulated packet
/// </summary>
/// <param name="p">
/// A <see cref="Packet"/>
/// </param>
/// <returns>
/// A <see cref="IpPacket"/>
/// </returns>
public static IpPacket GetEncapsulated(Packet p)
{
log.Debug("");
if (p is InternetLinkLayerPacket)
{
var payload = InternetLinkLayerPacket.GetInnerPayload((InternetLinkLayerPacket)p);
if (payload is IpPacket)
{
return((IpPacket)payload);
}
}
return(null);
}
/// <summary>
/// Returns the UdpPacket inside of the Packet p or null if
/// there is no encapsulated packet
/// </summary>
/// <param name="p">
/// A <see cref="Packet"/>
/// </param>
/// <returns>
/// A <see cref="UdpPacket"/>
/// </returns>
public static UdpPacket GetEncapsulated(Packet p)
{
if (p is InternetLinkLayerPacket)
{
var payload = InternetLinkLayerPacket.GetInnerPayload((InternetLinkLayerPacket)p);
if (payload is IpPacket)
{
var innerPayload = payload.PayloadPacket;
if (innerPayload is UdpPacket)
{
return((UdpPacket)innerPayload);
}
}
}
return(null);
}
