// // Copyright (C) 2004 Andras Varga // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. // // // Accepts any number of incoming TCP connections, and sends back the // messages that arrive on them, The lengths of the messages are // multiplied by echoFactor before sending them back (echoFactor=1 will // result in sending back the same message unmodified.) The reply can also be // delayed by a constant time (echoDelay parameter). // // When TCPEchoApp receives data packets from TCP (and such, when they can be // echoed) depends on the sendQueue/receiveQueue setting of TCP. // With TCPVirtualBytesSendQueue/RcvQueue, TCP passes up data to us // as soon as a segment arrives, so it can be echoed immediately. // With TCPMsgBasedSendQueue/RcvQueue, our local TCP reproduces the same // messages that the sender app passed down to its TCP -- so if the sender // app sent a single 100 MB message, it will be echoed only when all // 100 megabytes have arrived. // // Compatible with both IPv4 and IPv6. // simple TCPEchoApp parameters: address: string, // local address; may be left empty ("") port: numeric const, // port number to listen on echoFactor: numeric const, echoDelay: numeric const; gates: in: tcpIn; out: tcpOut; endsimple