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package org.bouncycastle.crypto.tls.test;
import java.io.IOException;
import java.util.Random;
import org.bouncycastle.crypto.tls.DatagramTransport;
public class UnreliableDatagramTransport
implements DatagramTransport
{
private final DatagramTransport transport;
private final Random random;
private final int percentPacketLossReceiving, percentPacketLossSending;
public UnreliableDatagramTransport(DatagramTransport transport, Random random,
int percentPacketLossReceiving, int percentPacketLossSending)
{
if (percentPacketLossReceiving < 0 || percentPacketLossReceiving > 100)
{
throw new IllegalArgumentException("'percentPacketLossReceiving' out of range");
}
if (percentPacketLossSending < 0 || percentPacketLossSending > 100)
{
throw new IllegalArgumentException("'percentPacketLossSending' out of range");
}
this.transport = transport;
this.random = random;
this.percentPacketLossReceiving = percentPacketLossReceiving;
this.percentPacketLossSending = percentPacketLossSending;
}
public int getReceiveLimit()
throws IOException
{
return transport.getReceiveLimit();
}
public int getSendLimit()
throws IOException
{
return transport.getSendLimit();
}
public int receive(byte[] buf, int off, int len, int waitMillis)
throws IOException
{
long endMillis = System.currentTimeMillis() + waitMillis;
for (; ; )
{
int length = transport.receive(buf, off, len, waitMillis);
if (length < 0 || !lostPacket(percentPacketLossReceiving))
{
return length;
}
System.out.println("PACKET LOSS (" + length + " byte packet not received)");
long now = System.currentTimeMillis();
if (now >= endMillis)
{
return -1;
}
waitMillis = (int)(endMillis - now);
}
}
public void send(byte[] buf, int off, int len)
throws IOException
{
if (lostPacket(percentPacketLossSending))
{
System.out.println("PACKET LOSS (" + len + " byte packet not sent)");
}
else
{
transport.send(buf, off, len);
}
}
public void close()
throws IOException
{
transport.close();
}
private boolean lostPacket(int percentPacketLoss)
{
return percentPacketLoss > 0 && random.nextInt(100) < percentPacketLoss;
}
}
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