1 files changed, 78 insertions, 0 deletions
diff --git a/core/src/main/jdk1.3/org/spongycastle/crypto/tls/UDPTransport.java b/core/src/main/jdk1.3/org/spongycastle/crypto/tls/UDPTransport.java
new file mode 100644
index 00000000..9391e1d2
--- /dev/null
+++ b/core/src/main/jdk1.3/org/spongycastle/crypto/tls/UDPTransport.java
@@ -0,0 +1,78 @@
+package org.spongycastle.crypto.tls;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+
+public class UDPTransport
+    implements DatagramTransport
+{
+    protected final static int MIN_IP_OVERHEAD = 20;
+    protected final static int MAX_IP_OVERHEAD = MIN_IP_OVERHEAD + 64;
+    protected final static int UDP_OVERHEAD = 8;
+
+    protected final DatagramSocket socket;
+    protected final int receiveLimit, sendLimit;
+
+    public UDPTransport(DatagramSocket socket, int mtu)
+        throws IOException
+    {
+        //
+        // In 1.3 and earlier sockets were bound and connected during creation
+        //
+        //if (!socket.isBound() || !socket.isConnected())
+        //{
+        //    throw new IllegalArgumentException("'socket' must be bound and connected");
+        //}
+
+        this.socket = socket;
+
+        // NOTE: As of JDK 1.6, can use NetworkInterface.getMTU
+
+        this.receiveLimit = mtu - MIN_IP_OVERHEAD - UDP_OVERHEAD;
+        this.sendLimit = mtu - MAX_IP_OVERHEAD - UDP_OVERHEAD;
+    }
+
+    public int getReceiveLimit()
+    {
+        return receiveLimit;
+    }
+
+    public int getSendLimit()
+    {
+        // TODO[DTLS] Implement Path-MTU discovery?
+        return sendLimit;
+    }
+
+    public int receive(byte[] buf, int off, int len, int waitMillis)
+        throws IOException
+    {
+        socket.setSoTimeout(waitMillis);
+        DatagramPacket packet = new DatagramPacket(buf, off, len);
+        socket.receive(packet);
+        return packet.getLength();
+    }
+
+    public void send(byte[] buf, int off, int len)
+        throws IOException
+    {
+        if (len > getSendLimit())
+        {
+            /*
+             * RFC 4347 4.1.1. "If the application attempts to send a record larger than the MTU,
+             * the DTLS implementation SHOULD generate an error, thus avoiding sending a packet
+             * which will be fragmented."
+             */
+            throw new TlsFatalAlert(AlertDescription.internal_error);
+        }
+
+        DatagramPacket packet = new DatagramPacket(buf, off, len);
+        socket.send(packet);
+    }
+
+    public void close()
+        throws IOException
+    {
+        socket.close();
+    }
+}