Add QuicChannel.applicationProtocol()

Motivation:

Add a method to access the application protocol that was negotated

Modifications:

Add method to access the application protocol

Result:

Be able to access the protocol

src/main/c/netty_quic_quiche.c

@@ -208,6 +208,23 @@ static jint netty_quic_quiche_conn_close(JNIEnv* env, jclass clazz, jlong conn,
     return quiche_conn_close((quiche_conn *) conn, app == JNI_TRUE ? true : false, err, (const uint8_t *) reason, (size_t) reason_len);
 }
 
+static jbyteArray netty_quic_quiche_conn_application_proto(JNIEnv* env, jclass clazz, jlong conn) {
+    const uint8_t *app_proto = NULL;
+    size_t app_proto_len;
+
+    quiche_conn_application_proto((quiche_conn *) conn, &app_proto, &app_proto_len);
+    if (app_proto == NULL || app_proto_len == 0) {
+        return NULL;
+    }
+     jbyteArray array = (*env)->NewByteArray(env, app_proto_len);
+     if (array == NULL) {
+        return NULL;
+     }
+     (*env)->SetByteArrayRegion(env,array,0,app_proto_len, (jbyte*) app_proto);
+     return array;
+}
+
+
 static jboolean netty_quic_quiche_conn_is_established(JNIEnv* env, jclass clazz, jlong conn) {
     return quiche_conn_is_established((quiche_conn *) conn) == true ? JNI_TRUE : JNI_FALSE;
 }
@@ -429,6 +446,7 @@ static const JNINativeMethod fixed_method_table[] = {
   { "quiche_conn_stream_shutdown", "(JJIJ)I", (void *) netty_quic_quiche_conn_stream_shutdown },
   { "quiche_conn_stream_capacity", "(JJ)I", (void *) netty_quic_quiche_conn_stream_capacity },
   { "quiche_conn_stream_finished", "(JJ)Z", (void *) netty_quic_quiche_conn_stream_finished },
+  { "quiche_conn_application_proto", "(J)[B", (void *) netty_quic_quiche_conn_application_proto },
   { "quiche_conn_close", "(JZJJI)I", (void *) netty_quic_quiche_conn_close },
   { "quiche_conn_is_established", "(J)Z", (void *) netty_quic_quiche_conn_is_established },
   { "quiche_conn_is_in_early_data", "(J)Z", (void *) netty_quic_quiche_conn_is_in_early_data },

src/main/java/io/netty/incubator/codec/quic/QuicChannel.java

@@ -39,4 +39,9 @@ public interface QuicChannel extends Channel {
      */
     Future<QuicStreamChannel> createStream(QuicStreamAddress address, ChannelHandler handler,
                                            Promise<QuicStreamChannel> promise);
+
+    /**
+     * Returns the negotiated ALPN protocol or {@code null} if non has been negotiated.
+     */
+    byte[] applicationProtocol();
 }

src/main/java/io/netty/incubator/codec/quic/Quiche.java

@@ -266,6 +266,13 @@ static native int quiche_retry(long scidAddr, int scidLen, long dcidAddr, int dc
      */
     static native int quiche_conn_close(long connAddr, boolean app, long err, long reasonAddr, int reasonLen);
 
+    /**
+     * See
+     * <a href="https://github.com/cloudflare/quiche/blob/0.6.0/include/quiche.h#L301">
+     *     quiche_conn_application_proto</a>.
+     */
+    static native byte[] quiche_conn_application_proto(long connAddr);
+
     /**
      * See
      * <a href="https://github.com/cloudflare/quiche/blob/0.6.0/include/quiche.h#L305">quiche_conn_is_established</a>.

src/main/java/io/netty/incubator/codec/quic/QuicheQuicChannel.java

@@ -195,6 +195,14 @@ public void run() {
         return promise;
     }
 
+    @Override
+    public byte[] applicationProtocol() {
+        if (isConnDestroyed()) {
+            return null;
+        }
+        return Quiche.quiche_conn_application_proto(connAddr);
+    }
+
     @Override
     public String toString() {
         String traceId = this.traceId;