feat(rustproxy-passthrough): add PROXY protocol v2 client IP handling for UDP and QUIC listeners

rust/crates/rustproxy-http/src/h3_service.rs

@@ -4,6 +4,7 @@
 //! and forwards them to backends using the same routing and pool infrastructure
 //! as the HTTP/1+2 proxy.
 
+use std::net::SocketAddr;
 use std::pin::Pin;
 use std::sync::Arc;
 use std::task::{Context, Poll};
@@ -61,13 +62,17 @@ impl H3ProxyService {
     }
 
     /// Handle an accepted QUIC connection as HTTP/3.
+    ///
+    /// If `real_client_addr` is provided (from PROXY protocol), it overrides
+    /// `connection.remote_address()` for client IP attribution.
     pub async fn handle_connection(
         &self,
         connection: quinn::Connection,
         _fallback_route: &RouteConfig,
         port: u16,
+        real_client_addr: Option<SocketAddr>,
     ) -> anyhow::Result<()> {
-        let remote_addr = connection.remote_address();
+        let remote_addr = real_client_addr.unwrap_or_else(|| connection.remote_address());
         debug!("HTTP/3 connection from {} on port {}", remote_addr, port);
 
         let mut h3_conn: h3::server::Connection<h3_quinn::Connection, Bytes> =