chore: better UserFromConn implementation

common/net/upstream.go

@@ -0,0 +1,28 @@
+package net
+
+import "net"
+
+type netConn interface {
+	NetConn() net.Conn
+}
+
+// FindUpstream finds a value in an upstream wrapper chain. If accept rejects a
+// matching value, the search continues so an outer wrapper cannot hide a valid
+// inner value of the same type.
+func FindUpstream[T any](value any, accept func(T) bool) (T, bool) {
+	for value != nil {
+		if candidate, ok := value.(T); ok && (accept == nil || accept(candidate)) {
+			return candidate, true
+		}
+		switch wrapper := value.(type) {
+		case WithUpstream:
+			value = wrapper.Upstream()
+		case netConn:
+			value = wrapper.NetConn()
+		default:
+			value = nil
+		}
+	}
+	var zero T
+	return zero, false
+}

transport/jls/jls.go

@@ -195,14 +195,14 @@ func Server(ctx context.Context, conn net.Conn, config *ServerConfig) (net.Conn,
 }
 
 func UserFromConn(conn net.Conn) (string, bool) {
-	tlsConn, ok := conn.(*tls.Conn)
+	tlsConn, ok := N.FindUpstream(conn, func(tlsConn *tls.Conn) bool {
+		state := tlsConn.ConnectionState().JLS
+		return state.Authenticated && state.User != ""
+	})
 	if !ok {
 		return "", false
 	}
 	state := tlsConn.ConnectionState().JLS
-	if !state.Authenticated || state.User == "" {
-		return "", false
-	}
 	return state.User, true
 }
 

transport/jls/jls_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	N "github.com/metacubex/mihomo/common/net"
 	"github.com/metacubex/mihomo/component/ca"
 
 	"github.com/metacubex/http"
@@ -56,7 +57,8 @@ func testJLSClientServer(t *testing.T, clientFingerprint string) {
 			serverDone <- errors.New("server did not authenticate JLS user")
 			return
 		}
-		if authenticatedUser, ok := UserFromConn(conn); !ok || authenticatedUser != user.Username {
+		outerTLS := tls.Server(N.NewBufferedConn(N.NewCachedConn(conn, nil)), &tls.Config{})
+		if authenticatedUser, ok := UserFromConn(outerTLS); !ok || authenticatedUser != user.Username {
 			serverDone <- errors.New("server did not expose JLS user")
 			return
 		}

transport/shadowtls/server.go

@@ -289,7 +289,7 @@ type authenticatedConn struct {
 func (c *authenticatedConn) Upstream() any { return c.Conn }
 
 func UserFromConn(conn net.Conn) (string, bool) {
-	authenticated, ok := conn.(*authenticatedConn)
+	authenticated, ok := N.FindUpstream[*authenticatedConn](conn, nil)
 	if !ok {
 		return "", false
 	}

transport/shadowtls/server_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 	"time"
 
+	N "github.com/metacubex/mihomo/common/net"
 	"github.com/metacubex/mihomo/component/ca"
 	"github.com/metacubex/tls"
 )
@@ -98,6 +99,21 @@ func TestServer(t *testing.T) {
 	}
 }
 
+func TestUserFromConnThroughWrappers(t *testing.T) {
+	left, right := net.Pipe()
+	t.Cleanup(func() {
+		_ = left.Close()
+		_ = right.Close()
+	})
+	authenticated := &authenticatedConn{Conn: left, user: "test-user"}
+	conn := N.NewBufferedConn(N.NewCachedConn(authenticated, nil))
+
+	user, ok := UserFromConn(conn)
+	if !ok || user != authenticated.user {
+		t.Fatalf("UserFromConn() = (%q, %v), want (%q, true)", user, ok, authenticated.user)
+	}
+}
+
 func TestV3UnauthenticatedConnectionFallsBack(t *testing.T) {
 	camouflageAddr := startCamouflageServer(t, false)
 	serverConfig := newTestServerConfig(t, 3, camouflageAddr)

transport/simple-obfs/http_server.go

@@ -22,6 +22,10 @@ type HTTPObfsServer struct {
 	firstResponse bool
 }
 
+func (hos *HTTPObfsServer) Upstream() any {
+	return hos.Conn
+}
+
 func (hos *HTTPObfsServer) Read(b []byte) (int, error) {
 	if hos.buf != nil {
 		n := copy(b, hos.buf[hos.offset:])

transport/simple-obfs/tls_server.go

@@ -19,6 +19,10 @@ type TLSObfsServer struct {
 	firstResponse     bool
 }
 
+func (tos *TLSObfsServer) Upstream() any {
+	return tos.Conn
+}
+
 func (tos *TLSObfsServer) read(b []byte, discardN int) (int, error) {
 	buf := pool.Get(discardN)
 	_, err := io.ReadFull(tos.Conn, buf)