// override the OnReceive
override internal NetStatus OnReceive(object sender, NetPacket pkt, object ctx)
{
#if DEBUG
Console.Out.WriteLine("PrivateIcmpSession:OnReceived, flow capacity={0}", capacity);
#endif
Debug.Assert(ctx != null);
NetStatus res = NetStatus.Code.PROTOCOL_OK;
IcmpFormat.IcmpHeader icmpHeader = (IcmpFormat.IcmpHeader)ctx;
IPFormat.IPHeader ipHeader = pkt.OverlapContext as IPFormat.IPHeader;
Multiplexer mux = pkt.AdapterContext as Multiplexer; // source mux
Debug.Assert(ipHeader != null && mux != null);
bool handled = false;
// handle various types
switch (icmpHeader.type)
{
case (byte)IcmpFormat.IcmpType.ECHO_REQUEST:
if (icmpHeader.code == 0)
{
#if DEBUG_IP
Console.WriteLine("PrivateIcmpSession: Handling ECHO_REQUEST From: {0}", ipHeader.srcAddrIP);
#endif
// send reply
// clone it since some session may use it (it is readonly!)
int length = pkt.Length();
byte [] pktData = new byte [length];
Array.Copy(pkt.GetRawData(), 0, pktData, 0, length);
IcmpFormat.CreateFastEchoReply(
pktData,
ipHeader.totalLength - IPFormat.Size
);
NetPacket reply = new NetPacket(pktData);
reply.SessionContext = this;
mux.Send(reply);
handled = true;
}
break;
default:
break;
}
// return the original packet (no use for it anymore)
pkt.ReleaseRef();
// only increment the session capacity
// if this is not ours..
// this way we apply back pressure and only
// increase the capacity once sending is done!
if (!handled)
{
capacity++;
}
#if DEBUG
Console.Out.WriteLine("PrivateIcmpSession:OnReceived FINISHED, flow capacity={0}", capacity);
#endif
return(res);
}
// the session event dispatching instance
// public event Session.OnPacketReceive sessions;
// handle incoming IP packets
public NetStatus OnProtocolReceive(NetPacket !pkt)
{
// handle ICMP messages
// ---------------------
// start analyzing the request
Multiplexer !mux = (!)Core.Instance().GetMuxForAdapter((IAdapter !)pkt.AdapterContext);
// IP should have passed us a context which
// is the IPHeader... lets see...
IPFormat.IPHeader !ipHeader = (IPFormat.IPHeader !)pkt.OverlapContext;
// read the icmp header
IcmpFormat.IcmpHeader icmpHeader;
if (!IcmpFormat.ReadIcmpHeader(pkt, out icmpHeader))
{
return(NetStatus.Code.PROTOCOL_OK);
}
// handle various types
switch (icmpHeader.type)
{
case (byte)IcmpFormat.IcmpType.ECHO_REQUEST:
if (icmpHeader.code == 0)
{
DebugPrint("IcmpModule: Handling ECHO_REQUEST From: {0}", ipHeader.Source);
// send reply
int length = pkt.Length;
byte [] pktData = new byte [length];
Array.Copy(pkt.GetRawData(), 0, pktData, 0, length);
IcmpFormat.CreateFastEchoReply(
pktData,
ipHeader.totalLength - IPFormat.Size
);
NetPacket reply = new NetPacket(pktData);
mux.SendDirect(reply);
return(NetStatus.Code.PROTOCOL_OK);
}
break;
default:
break;
}
DebugPrint("IcmpModule: Dispatching packet to Sessions");
// our sessions wants the IP header as well, IP
// already shrinked the packet for us so no need
// to shrink the packet
pkt.Clip(EthernetFormat.Size, ipHeader.totalLength - 1);
// fire the event to any interested sessions
// (we could also use Core.Instance().Sessions to
// choose a specific session...)
// if (sessions != null)
//{
//sessions(this, pkt, icmpHeader);
//}
return(NetStatus.Code.PROTOCOL_OK);
}
