// This method is called for each frame which is sent to the traffic handler.
// It's the core method where all the work should be done.
protected override void HandleTraffic(Frame fInputFrame)
{
//Each handler has some support methods
// Gets the IP component of the input frame, or null, if no IP component is present.
eExNetworkLibrary.IP.IPFrame ipFrame = GetIPFrame(fInputFrame);
eExNetworkLibrary.IP.IPv4Frame ipv4Frame = GetIPv4Frame(fInputFrame);
eExNetworkLibrary.IP.V6.IPv6Frame ipv6Frame = GetIPv6Frame(fInputFrame);
//This is also possible for TCP-Frames and so on
eExNetworkLibrary.TCP.TCPFrame tcpFrame = GetTCPFrame(fInputFrame);
//There are also some helper classes
eExNetworkLibrary.IP.IPAddressAnalysis.GetIPRange(
new System.Net.IPAddress(new byte[] { 192, 168, 1, 1 }),
new System.Net.IPAddress(new byte[] { 192, 168, 1, 254 }));
if (tcpFrame != null)
{
//Now, do something with the frame.
tcpFrame.DestinationPort = 8080;
//The payload of a frame is set in the EncapsulatedFrame property.
//For example, an Ethernet frame has an encapsulated IPFrame, the IPFrame has
//an encapsulated TCP frame, and the encapsulated frame of the TCP frame is
//the payload data.
tcpFrame.EncapsulatedFrame = null; //Delete the payload of the TCP frame
//But don't forget to adjust checksums if you modify traffic.
//Also you have to use the pseudo-header of the right frame
tcpFrame.Checksum = tcpFrame.CalculateChecksum(ipFrame.GetPseudoHeader());
}
//Push the frame to the next handler.
//Omit this call, if you want to discard the frame.
NotifyNext(fInputFrame);
}
private bool IsLocal(eExNetworkLibrary.IP.IPFrame ipv4Frame)
{
return(lLocalAddresses.Contains(ipv4Frame.SourceAddress) || lLocalAddresses.Contains(ipv4Frame.DestinationAddress));
}
/// <summary>
/// Checkes whether this rule matches a given frame.
/// </summary>
/// <param name="frame">The original frame</param>
/// <param name="ethFrame">The Ethernet part of the frame</param>
/// <param name="ipv4Frame">The IPv4 part of the frame</param>
/// <param name="udpFrame">The UDP part of the frame</param>
/// <param name="tcpFrame">The TCP part of the frame</param>
/// <returns>A bool indicating whether this rule matches a given frame.</returns>
public override bool IsMatch(Frame frame, eExNetworkLibrary.Ethernet.EthernetFrame ethFrame, eExNetworkLibrary.IP.IPFrame ipFrame, eExNetworkLibrary.UDP.UDPFrame udpFrame, eExNetworkLibrary.TCP.TCPFrame tcpFrame)
{
bool bResult;
int iFrameSourcePort = 0;
int iFrameDestinationPort = 0;
if ((this.tProtocol == TransportProtocol.Any || this.tProtocol == TransportProtocol.TCP) && tcpFrame != null)
{
iFrameDestinationPort = tcpFrame.DestinationPort;
iFrameSourcePort = tcpFrame.SourcePort;
}
else if ((this.tProtocol == TransportProtocol.Any || this.tProtocol == TransportProtocol.TCP) && udpFrame != null)
{
iFrameSourcePort = udpFrame.SourcePort;
iFrameDestinationPort = udpFrame.DestinationPort;
}
else
{
return(false); //We have no TCP/UDP frame.
}
if (iPort != -1)
{
//Single port match
bResult = iPort == iFrameDestinationPort || iPort == iFrameSourcePort;
}
else
{
bResult = (iSourcePort == -1 || iSourcePort == iFrameSourcePort) && (iDestinationPort == -1 || iDestinationPort == iFrameDestinationPort);
}
return(bResult && base.IsMatch(frame, ethFrame, ipFrame, udpFrame, tcpFrame));
}
/// <summary>
/// Checkes whether this rule matches a given frame.
/// </summary>
/// <param name="frame">The original frame</param>
/// <param name="ethFrame">The Ethernet part of the frame</param>
/// <param name="ipv4Frame">The IPv4 part of the frame</param>
/// <param name="udpFrame">The UDP part of the frame</param>
/// <param name="tcpFrame">The TCP part of the frame</param>
/// <returns>A bool indicating whether this rule matches a given frame.</returns>
public override bool IsMatch(Frame frame, eExNetworkLibrary.Ethernet.EthernetFrame ethFrame, eExNetworkLibrary.IP.IPFrame ipFrame, eExNetworkLibrary.UDP.UDPFrame udpFrame, eExNetworkLibrary.TCP.TCPFrame tcpFrame)
{
if (ipFrame != null)
{
bool bResult;
if (ipaAddress != null)
{
bResult = Match(ipFrame.SourceAddress, ipaAddress, smWildcard) ||
Match(ipFrame.DestinationAddress, ipaAddress, smWildcard);
}
else
{
bResult = Match(ipFrame.SourceAddress, ipaSource, smSourceWildcard) &&
Match(ipFrame.DestinationAddress, ipaDestination, smDestinationWildcard);
}
return(bResult && base.IsMatch(frame, ethFrame, ipFrame, udpFrame, tcpFrame));
}
return(false);
}
