Add naive inbound and test

inbound/naive_quic.go

@@ -0,0 +1,40 @@
+//go:build with_quic
+
+package inbound
+
+import (
+	"net"
+	"net/netip"
+
+	M "github.com/sagernet/sing/common/metadata"
+
+	"github.com/lucas-clemente/quic-go"
+	"github.com/lucas-clemente/quic-go/http3"
+)
+
+func (n *Naive) configureHTTP3Listener(listenAddr string) error {
+	h3Server := &http3.Server{
+		Port:      int(n.listenOptions.ListenPort),
+		TLSConfig: n.tlsConfig.Config(),
+		Handler:   n,
+	}
+
+	udpListener, err := net.ListenPacket(M.NetworkFromNetAddr("udp", netip.Addr(n.listenOptions.Listen)), listenAddr)
+	if err != nil {
+		return err
+	}
+
+	n.logger.Info("udp server started at ", udpListener.LocalAddr())
+
+	go func() {
+		sErr := h3Server.Serve(udpListener)
+		if sErr == quic.ErrServerClosed {
+			return
+		} else if sErr != nil {
+			n.logger.Error("http3 server serve error: ", sErr)
+		}
+	}()
+
+	n.h3Server = h3Server
+	return nil
+}