udp: Add source address option

This option allows to specify the source address and port for outgoing
UDP packets.

Signed-off-by: Konrad Gräfe <kgraefe@paktolos.net>

src/adapters/udp.rs

@@ -26,12 +26,24 @@ pub const MAX_LOCAL_PAYLOAD_LEN: usize = 65535 - 20 - 8;
 #[cfg(target_os = "macos")]
 pub const MAX_LOCAL_PAYLOAD_LEN: usize = 9216 - 20 - 8;
 
-#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct UdpConnectConfig {
+    /// Specify the source address and port.
+    pub source_address: SocketAddr,
+
     /// Enables the socket capabilities to send broadcast messages.
     pub broadcast: bool,
 }
 
+impl Default for UdpConnectConfig {
+    fn default() -> Self {
+        Self {
+            source_address: SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, 0).into(),
+            broadcast: false,
+        }
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
 pub struct UdpListenConfig {
     /// Enables the socket capabilities to send broadcast messages when the listening socket is
@@ -66,7 +78,7 @@ impl Remote for RemoteResource {
             _ => panic!("Internal error: Got wrong config"),
         };
 
-        let socket = UdpSocket::bind("0.0.0.0:0".parse().unwrap())?;
+        let socket = UdpSocket::bind(config.source_address)?;
         let peer_addr = *remote_addr.socket_addr();
 
         if config.broadcast {

src/network.rs

@@ -126,7 +126,7 @@ impl NetworkController {
     /// let (handler, listener) = node::split();
     /// handler.signals().send_with_timer((), std::time::Duration::from_secs(1));
     ///
-    /// let config = UdpConnectConfig { broadcast: true };
+    /// let config = UdpConnectConfig { broadcast: true, ..Default::default() };
     /// let addr = "255.255.255.255:7777";
     /// let (conn_endpoint, _) = handler.network().connect_with(TransportConnect::Udp(config), addr).unwrap();
     /// // The socket could not be able to send yet.
@@ -226,7 +226,7 @@ impl NetworkController {
     /// let (handler, listener) = node::split();
     /// handler.signals().send_with_timer((), std::time::Duration::from_secs(1));
     ///
-    /// let config = UdpConnectConfig { broadcast: true };
+    /// let config = UdpConnectConfig { broadcast: true, ..Default::default() };
     /// let addr = "255.255.255.255:7777";
     /// match handler.network().connect_sync_with(TransportConnect::Udp(config), addr) {
     ///     Ok((endpoint, _)) => {