/**
* This handles the packet forwarding protocol
*/
public void HandleData(MemBlock b, ISender ret_path, object state)
{
/*
* Check it
*/
AHSender ahs = ret_path as AHSender;
if( ahs != null ) {
//This was an AHSender:
/*
* This goes A -> B -> C
*/
if( b[0] == 0 ) {
int offset = 1;
//This is the first leg, going from A->B
Address add_c = AddressParser.Parse(b.Slice(offset, Address.MemSize));
offset += Address.MemSize;
//Since ahs a sender to return, we would be the source:
Address add_a = ahs.Destination;
short ttl = NumberSerializer.ReadShort(b, offset);//2 bytes
offset += 2;
ushort options = (ushort) NumberSerializer.ReadShort(b, offset);//2 bytes
offset += 2;
MemBlock payload = b.Slice(offset);
MemBlock f_header = MemBlock.Reference( new byte[]{1} );
/*
* switch the packet from [A B f0 C] to [B C f 1 A]
*/
ICopyable new_payload = new CopyList(PType.Protocol.Forwarding,
f_header, add_a, payload);
/*
* ttl and options are present in the forwarding header.
*/
AHSender next = new AHSender(_n, ahs.ReceivedFrom, add_c,
ttl,
options);
next.Send(new_payload);
}
else if ( b[0] == 1 ) {
/*
* This is the second leg: B->C
* Make a Forwarding Sender, and unwrap the inside packet
*/
Address add_a = AddressParser.Parse(b.Slice(1, Address.MemSize));
Address add_b = ahs.Destination;
MemBlock rest_of_payload = b.Slice(1 + Address.MemSize);
//Here's the return path:
ISender new_ret_path = new ForwardingSender(_n, add_b, add_a);
_n.HandleData(rest_of_payload, new_ret_path, this);
}
}
else {
//This is not (currently) supported.
Console.Error.WriteLine("Got a forwarding request from: {0}", ret_path);
}
}
