What to do in muxHandler()?

Get the headers  Use function MinetReceive to get the packet p.  Get the TCPHeader and IPHeader of p. You can use the function in class Packet. For example, FindHeader function. You can get the Tcpheader by using p.FindHeader(Headers::TCPHeader);

Find the connections  Extract information from the IPHeaders and TCPHeaders. For example, src ip & port and dest ip &port. For example, using iph.GetDestIP function.(suppose iph is the ip header)  Use the information above to find the connection the packet belongs in Clist. Clist is used for keeping all connections built. For example, using ConnectionList ::iterator cs = clist.FindMatching(c);// Specify c with src & dest information

Parse tcp header  Get the state of current connection. You may need to modify it based on the packet received. For example, using (*cs).state.GetState();  Get the flags of TCP header, using tcph.GetFlags(f). Then check whether it is SYN, ACK, FIN.. And do corresponding action based on current state.

For Example  if( IS_ACK(f) && IS_SYN(f) )  {  cout<<"SYN ACK packet Received. will have to send ACK packet"<<endl;  p.Print(cout);  if( state == SYN_SENT )  {  connstate.state.SetState(ESTABLISHED);  unsigned int newack,last_recvd;  tcph.GetAckNum(newack);  tcph.GetSeqNum(last_recvd);  connstate.state.SetLastAcked( newack );  connstate.state.SetLastRecvd( last_recvd );  connstate.timeout=Time() + ACK_TIMEOUT;  char *data1 = "ACTIVE:in active connection\n";  Buffer b(data1,strlen(data1));  Packet psh;  unsigned int old_time;  TCPOptions opt;  tcph.GetOptions(opt);  old_time = ntohl(*(int *)(opt.data+8));  craftSynPacket(&psh,connstate,PSH_ACK_HEADER,0,old_time);  psh.Print(cout);  MinetSend(mux,psh);  connstate.state.SetLastSent(connstate.state.GetLastSent());  status=STATUS;  MinetSend(sock,write);  }