[client/network] Add support for /wss addresses (#13152)

* join dns with another instance of WS transport

Secure Websocket transport needs unresolved addresses, so we join DNS transport with
yet another instance of Websocket transport.

Closes #12024

* WSS transport itself need to wrap DNS transport

in order to resolve addresses before passing them down to TCP transport

Refs libp2p/rust-libp2p#3330

* reverse order

* simplify code: remove WS from WSS inner DNS transport

* remove the 2nd instance of WS transport

client/network/src/transport.rs

@@ -54,18 +54,27 @@ pub fn build_transport(
 ) -> (Boxed<(PeerId, StreamMuxerBox)>, Arc<BandwidthSinks>) {
  // Build the base layer of the transport.
  let transport = if !memory_only {
+ // Main transport: DNS(TCP)
  let tcp_config = tcp::Config::new().nodelay(true);
- let desktop_trans = tcp::tokio::Transport::new(tcp_config.clone());
- let desktop_trans = websocket::WsConfig::new(desktop_trans)
- .or_transport(tcp::tokio::Transport::new(tcp_config.clone()));
- let dns_init = dns::TokioDnsConfig::system(desktop_trans);
+ let tcp_trans = tcp::tokio::Transport::new(tcp_config.clone());
+ let dns_init = dns::TokioDnsConfig::system(tcp_trans);
+
  EitherTransport::Left(if let Ok(dns) = dns_init {
- EitherTransport::Left(dns)
+ // WS + WSS transport
+ //
+ // Main transport can't be used for `/wss` addresses because WSS transport needs
+ // unresolved addresses (BUT WSS transport itself needs an instance of DNS transport to
+ // resolve and dial addresses).
+ let tcp_trans = tcp::tokio::Transport::new(tcp_config);
+ let dns_for_wss = dns::TokioDnsConfig::system(tcp_trans)
+ .expect("same system_conf & resolver to work");
+ EitherTransport::Left(websocket::WsConfig::new(dns_for_wss).or_transport(dns))
  } else {
- let desktop_trans = tcp::tokio::Transport::new(tcp_config.clone());
- let desktop_trans = websocket::WsConfig::new(desktop_trans)
+ // In case DNS can't be constructed, fallback to TCP + WS (WSS won't work)
+ let tcp_trans = tcp::tokio::Transport::new(tcp_config.clone());
+ let desktop_trans = websocket::WsConfig::new(tcp_trans)
  .or_transport(tcp::tokio::Transport::new(tcp_config));
- EitherTransport::Right(desktop_trans.map_err(dns::DnsErr::Transport))
+ EitherTransport::Right(desktop_trans)
  })
  } else {
  EitherTransport::Right(OptionalTransport::some(