private boolean sendAck(Packet p, DatagramPacket dp) {
// Respond
// System.out.println("RT: Sending ack for packet w/ seqnum: " + p.getSeqNum());
Packet hsp = new Packet(p.getSeqNum());
hsp.assembleHandshakePacket();
packet =
new DatagramPacket(hsp.getPacketData(), hsp.getPacketSize(), dp.getAddress(), dp.getPort());
try {
socket.send(packet);
} catch (Exception e) {
System.out.println("RT: Could not send ack packet:\n" + e.getMessage());
return false;
}
return true;
}
private int processHandshake(Packet p, InetAddress ip, int port) throws Exception {
// System.out.println("Got handshake");
// Get connection information
this.numMessages = p.getNumMessages();
this.totalDataSize = p.getTotalDataLength();
this.seqNum = p.getSeqNum();
// Respond
// System.out.println("RT: Sending handshake response");
Packet hsp = new Packet(seqNum);
hsp.assembleHandshakePacket();
packet = new DatagramPacket(hsp.getPacketData(), hsp.getPacketSize(), ip, port);
socket.send(packet);
// System.out.println("RT: Done with handshake:\n\tStarting seqnum: "+seqNum+"\n\tTotal datalen:
// "+totalDataSize);
return 1; // FIXME p.getNumMessages();
}
private MyMessage getMessage() throws Exception {
int dataRecieved = 0;
String m = new String();
String t;
// FIXME needs to get multiple packets and messages
// System.out.println("RT: Now waiting for message data");
while (dataRecieved < totalDataSize) {
// Get message data
response = new byte[65000];
DatagramPacket packet = new DatagramPacket(response, response.length);
socket.receive(packet);
Packet p = new Packet(packet.getData());
// System.out.println("RT: Got message with seqnum: "+p.getSeqNum());
// If we have a handshake packet something broke
if (p.isHandshake()) {
return null;
}
// If next in-order packet grab data and is not corrupt
// XXX
if (p.getSeqNum() == seqNum + 1 && p.checkChecksum()) {
// Get the message ( part? )
// System.out.println("RT: Is correct seqnum");
t = p.getMessages().get(0).getMessageContents();
// System.out.println("RT: Got message packet: " + t);
m += t;
// Send ack
sendAck(p, packet);
// Increment counters
dataRecieved += t.length();
seqNum++;
} else {
System.out.println("RT: Is NOT correct seqnum");
}
}
MyMessage result = new MyMessage();
result.setMessageContents(m);
return result;
}
