refactor: restructure server start procedure

src/internal/netfilter/nfqueue.go

@@ -64,11 +64,6 @@ func (s *NfqueueServer) Start() error {
 	if err != nil {
 		return fmt.Errorf("nfq.Open: %w", err)
 	}
-	defer func() {
-		if cerr := nf.Close(); cerr != nil {
-			slog.Error("nf.Close", slog.Any("error", cerr))
-		}
-	}()
 	s.Nf = nf
 
 	// Ignore ENOBUFS to prevent queue drop logs

src/internal/server/http/http.go

@@ -44,7 +44,12 @@ func (s *Server) Start() (err error) {
 			}
 		}),
 	}
-	return server.ListenAndServe()
+	go func() {
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			slog.Error("server.ListenAndServe", slog.Any("error", err))
+		}
+	}()
+	return nil
 }
 
 func (s *Server) Close() (err error) {

src/internal/server/netlink/netlink_linux.go

@@ -42,7 +42,7 @@ func New(cfg *config.Config) *Server {
 func (s *Server) Start() (err error) {
 	err = s.Firewall.Setup(s.cfg)
 	if err != nil {
-		slog.Error("Firewall.Setup", slog.Any("error", err))
+		slog.Error("s.Firewall.Setup", slog.Any("error", err))
 		return err
 	}
 	if s.cfg.DelTCPTimestamp || s.cfg.SetIPID {

src/internal/server/redirect/redirect_linux.go

@@ -56,20 +56,24 @@ func (s *Server) Start() (err error) {
 	if s.listener, err = net.Listen("tcp", s.Cfg.ListenAddr); err != nil {
 		return fmt.Errorf("net.Listen: %w", err)
 	}
-	var client net.Conn
+
-	for {
+	go func() {
-		if client, err = s.listener.Accept(); err != nil {
+		var client net.Conn
-			if errors.Is(err, syscall.EMFILE) {
+		for {
-				time.Sleep(time.Second)
+			if client, err = s.listener.Accept(); err != nil {
-			} else if errors.Is(err, net.ErrClosed) {
+				if errors.Is(err, syscall.EMFILE) {
-				return nil
+					time.Sleep(time.Second)
+				} else if errors.Is(err, net.ErrClosed) {
+					return
+				}
+				slog.Error("s.listener.Accept", slog.Any("error", err))
+				continue
 			}
-			slog.Error("s.listener.Accept", slog.Any("error", err))
+			slog.Debug("Accept connection", slog.String("addr", client.RemoteAddr().String()))
-			continue
+			go s.HandleClient(client)
 		}
-		slog.Debug("Accept connection", slog.String("addr", client.RemoteAddr().String()))
+	}()
-		go s.HandleClient(client)
+	return nil
-	}
 }
 
 func (s *Server) Close() error {

src/internal/server/socks5/socks5.go

@@ -63,20 +63,24 @@ func (s *Server) Start() (err error) {
 	if s.listener, err = net.Listen("tcp", s.Cfg.ListenAddr); err != nil {
 		return fmt.Errorf("net.Listen: %w", err)
 	}
-	var client net.Conn
+
-	for {
+	go func() {
-		if client, err = s.listener.Accept(); err != nil {
+		var client net.Conn
-			if errors.Is(err, syscall.EMFILE) {
+		for {
-				time.Sleep(time.Second)
+			if client, err = s.listener.Accept(); err != nil {
-			} else if errors.Is(err, net.ErrClosed) {
+				if errors.Is(err, syscall.EMFILE) {
-				return nil
+					time.Sleep(time.Second)
+				} else if errors.Is(err, net.ErrClosed) {
+					return
+				}
+				slog.Error("s.listener.Accept", slog.Any("error", err))
+				continue
 			}
-			slog.Error("s.listener.Accept", slog.Any("error", err))
+			slog.Debug("Accept connection", slog.String("addr", client.RemoteAddr().String()))
-			continue
+			go s.HandleClient(client)
 		}
-		slog.Debug("Accept connection", slog.String("addr", client.RemoteAddr().String()))
+	}()
-		go s.HandleClient(client)
+	return nil
-	}
 }
 
 // handleClient performs SOCKS5 negotiation and dispatches TCP/UDP handling.

src/internal/server/tproxy/tproxy_linux.go

@@ -64,7 +64,7 @@ func (s *Server) Start() error {
 
 	err = s.Firewall.Setup(s.Cfg)
 	if err != nil {
-		slog.Error(fmt.Sprintf("s.Firewall.Setup: %v", err))
+		slog.Error("s.Firewall.Setup", slog.Any("error", err))
 		return err
 	}
 	lc := net.ListenConfig{
@@ -87,20 +87,24 @@ func (s *Server) Start() error {
 	if s.listener, err = lc.Listen(context.TODO(), "tcp", s.Cfg.ListenAddr); err != nil {
 		return fmt.Errorf("net.Listen: %w", err)
 	}
-	var client net.Conn
+
-	for {
+	go func() {
-		if client, err = s.listener.Accept(); err != nil {
+		var client net.Conn
-			if errors.Is(err, syscall.EMFILE) {
+		for {
-				time.Sleep(time.Second)
+			if client, err = s.listener.Accept(); err != nil {
-			} else if errors.Is(err, net.ErrClosed) {
+				if errors.Is(err, syscall.EMFILE) {
-				return nil
+					time.Sleep(time.Second)
+				} else if errors.Is(err, net.ErrClosed) {
+					return
+				}
+				slog.Error(fmt.Sprintf("s.listener.Accept: %v", err))
+				continue
 			}
-			slog.Error(fmt.Sprintf("s.listener.Accept: %v", err))
+			slog.Debug(fmt.Sprintf("Accept connection from %s", client.RemoteAddr().String()))
-			continue
+			go s.HandleClient(client)
 		}
-		slog.Debug(fmt.Sprintf("Accept connection from %s", client.RemoteAddr().String()))
+	}()
-		go s.HandleClient(client)
+	return nil
-	}
 }
 
 func (s *Server) Close() error {

src/main.go

@@ -5,7 +5,6 @@ import (
 	"log/slog"
 	"os"
 	"os/signal"
-	"sync"
 	"syscall"
 
 	"github.com/sunbk201/ua3f/internal/config"
@@ -57,34 +56,36 @@ func main() {
 		return
 	}
 
-	cleanup := make(chan os.Signal, 1)
-	signal.Notify(cleanup, syscall.SIGQUIT, syscall.SIGINT, syscall.SIGTERM)
-
-	var shutdownOnce sync.Once
 	shutdown := func() {
-		shutdownOnce.Do(func() {
+		if err := helper.Close(); err != nil {
-			if err := helper.Close(); err != nil {
+			slog.Error("helper.Close", slog.Any("error", err))
-				slog.Error("helper.Close", slog.Any("error", err))
+		}
-			}
+		if err := srv.Close(); err != nil {
-			if err := srv.Close(); err != nil {
+			slog.Error("srv.Close", slog.Any("error", err))
-				slog.Error("srv.Close", slog.Any("error", err))
+		}
-			}
+		slog.Info("UA3F exit")
-			slog.Info("UA3F exited gracefully")
-		})
 	}
 
 	go statistics.StartRecorder()
 
-	go func() {
-		<-cleanup
-		shutdown()
-		os.Exit(0)
-	}()
-
-	defer shutdown()
-
 	if err := srv.Start(); err != nil {
 		slog.Error("srv.Start", slog.Any("error", err))
+		shutdown()
 		return
 	}
+
+	cleanup := make(chan os.Signal, 1)
+	signal.Notify(cleanup, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGINT, syscall.SIGTERM)
+	for {
+		s := <-cleanup
+		slog.Info("Received signal", slog.String("signal", s.String()))
+		switch s {
+		case syscall.SIGQUIT, syscall.SIGINT, syscall.SIGTERM:
+			shutdown()
+			return
+		case syscall.SIGHUP:
+		default:
+			return
+		}
+	}
 }