Update default_port and sni logic to improve reverse proxy reachability (#947)

easytier/src/common/dns.rs

@@ -77,6 +77,15 @@ pub async fn socket_addrs(
         .port()
         .or_else(default_port_number)
         .ok_or(Error::InvalidUrl(url.to_string()))?;
+    // See https://github.com/EasyTier/EasyTier/pull/947
+    let port = match port {
+        0 => match url.scheme() {
+            "ws" => 80,
+            "wss" => 443,
+            _ => port,
+        },
+        _ => port,
+    };
 
     // if host is an ip address, return it directly
     if let Ok(ip) = host.parse::<std::net::IpAddr>() {

easytier/src/tunnel/websocket.rs

@@ -202,8 +202,11 @@ impl WSTunnelConnector {
             init_crypto_provider();
             let tls_conn =
                 tokio_rustls::TlsConnector::from(Arc::new(get_insecure_tls_client_config()));
-            // Modify SNI logic: always use "localhost" as SNI to avoid IP blocking.
-            let sni = "localhost";
+            // Modify SNI logic: use "localhost" as SNI for url without domain to avoid IP blocking.
+            let sni = match addr.domain() {
+                None => "localhost".to_string(),
+                Some(domain) => domain.to_string(),
+            };
             let server_name = rustls::pki_types::ServerName::try_from(sni)
                 .map_err(|_| TunnelError::InvalidProtocol("Invalid SNI".to_string()))?;
             let stream = tls_conn.connect(server_name, stream).await?;