Allow the QuicConnectionIdGenerator also take the source connection i…

…d into account

Motivation:

Sometimes its useful to use the source and destination connection id to generate a connection id

Modifications:

- Add new default method to QuicConnectionIdGenerator that implementations can implement
- Call new method when it makes sense

Result:

More flexible connection id generation on the server

codec-classes-quic/src/main/java/io/netty/incubator/codec/quic/QuicCodecDispatcher.java

@@ -280,6 +280,14 @@ public ByteBuffer newId(ByteBuffer input, int length) {
             return idGenerator.newId(input, length);
         }
 
+        @Override
+        public ByteBuffer newId(ByteBuffer scid, ByteBuffer dcid, int length) {
+            if (length > Short.BYTES) {
+                return encodeIdx(idGenerator.newId(scid, dcid, length - Short.BYTES), idx);
+            }
+            return idGenerator.newId(scid, dcid, length);
+        }
+
         @Override
         public int maxConnectionIdLength() {
             return idGenerator.maxConnectionIdLength();

codec-classes-quic/src/main/java/io/netty/incubator/codec/quic/QuicConnectionIdGenerator.java

@@ -42,6 +42,19 @@ public interface QuicConnectionIdGenerator {
      */
     ByteBuffer newId(ByteBuffer input, int length);
 
+    /**
+     * Creates a new connection id with the given length. The given source connection id and destionation connection id
+     * may be used to sign or seed the id, or may be ignored (depending on the implementation).
+     *
+     * @param scid      the source connection id which may be used to generate the id.
+     * @param dcid      the destination connection id which may be used to generate the id.
+     * @param length    the length of the id.
+     * @return          the id.
+     */
+    default ByteBuffer newId(ByteBuffer scid, ByteBuffer dcid, int length) {
+        return newId(dcid, length);
+    }
+
     /**
      * Returns the maximum length of a connection id.
      *

codec-classes-quic/src/main/java/io/netty/incubator/codec/quic/QuicheQuicServerCodec.java

@@ -165,7 +165,9 @@ private QuicheQuicChannel handleServer(ChannelHandlerContext ctx, InetSocketAddr
             // The remote peer did not send a token.
             if (tokenHandler.writeToken(mintTokenBuffer, dcid, sender)) {
                 ByteBuffer connId = connectionIdAddressGenerator.newId(
-                        dcid.internalNioBuffer(dcid.readerIndex(), dcid.readableBytes()), localConnIdLength);
+                        scid.internalNioBuffer(scid.readerIndex(), scid.readableBytes()),
+                        dcid.internalNioBuffer(dcid.readerIndex(), dcid.readableBytes()),
+                        localConnIdLength);
                 connIdBuffer.writeBytes(connId);
 
                 ByteBuf out = ctx.alloc().directBuffer(Quic.MAX_DATAGRAM_SIZE);