Support for setting SNI extension on ssl socket handshake.

Need this to support virtual host ssl servers.

src/one/nio/net/NativeSslSocket.java

@@ -92,7 +92,7 @@ public Object getSslOption(SslOption option) {
         return null;
     }
     @Override
-    public synchronized native void handshake() throws IOException;
+    public synchronized native void handshake(String sniHostName) throws IOException;
 
     @Override
     public synchronized native int writeRaw(long buf, int count, int flags) throws IOException;

src/one/nio/net/Socket.java

@@ -174,7 +174,7 @@ public int send(ByteBuffer data, int flags, String host, int port) throws IOExce
         return send(data, flags, InetAddress.getByName(host), port);
     }
 
-    public void handshake() throws IOException {
+    public void handshake(String sniHostname) throws IOException {
         // Only for SSL sockets
     }
 

src/one/nio/net/native/ssl.c

@@ -1109,12 +1109,30 @@ Java_one_nio_net_NativeSslSocket_sslFree(JNIEnv* env, jclass cls, jlong sslptr)
     SSL_free(ssl);
 }
 
+static void set_tlsext_host_name(JNIEnv* env, SSL* ssl, jstring hostName) {
+     if (hostName != NULL) {
+         // set sni if hostname set to not ipv4/ipv6
+         struct in_addr ipv4;
+         struct in6_addr ipv6;
+         const char *value = (*env) -> GetStringUTFChars(env, hostName, NULL);
+         bool isIp = inet_pton(AF_INET, value, &ipv4) != 1 && inet_pton(AF_INET6, value, &ipv6) != 1;
+         (*env)->ReleaseStringUTFChars(env, hostName, value);
+         if (!isIp) {
+           int result = SSL_set_tlsext_host_name(ssl, value);
+           if (result <= 0) {
+               check_ssl_error(env, ssl, result);
+           }
+         }
+     }
+}
+
 JNIEXPORT void JNICALL
-Java_one_nio_net_NativeSslSocket_handshake(JNIEnv* env, jobject self) {
+Java_one_nio_net_NativeSslSocket_handshake(JNIEnv* env, jobject self, jstring hostName) {
     SSL* ssl = (SSL*)(intptr_t) (*env)->GetLongField(env, self, f_ssl);
     if (ssl == NULL) {
         throw_socket_closed(env);
     } else {
+        set_tlsext_host_name(env, ssl, hostName);
         int result = SSL_do_handshake(ssl);
         if (result <= 0) {
             check_ssl_error(env, ssl, result);

src/one/nio/pool/SocketPool.java

@@ -177,7 +177,7 @@ public Socket createObject() throws PoolException {
 
             if (sslContext != null) {
                 socket = socket.sslWrap(sslContext);
-                socket.handshake();
+                socket.handshake(host);
             }
 
             return socket;