diff --git a/analyzer/tcp/socks.go b/analyzer/tcp/socks.go
index 18ffc2b..a242069 100644
--- a/analyzer/tcp/socks.go
+++ b/analyzer/tcp/socks.go
@@ -208,10 +208,10 @@ func (s *socksStream) parseSocks5ReqMethod() utils.LSMAction {
 		switch method {
 		case Socks5AuthNotRequired:
 			s.authReqMethod = Socks5AuthNotRequired
-			break
+			return utils.LSMActionNext
 		case Socks5AuthPassword:
 			s.authReqMethod = Socks5AuthPassword
-			break
+			return utils.LSMActionNext
 		default:
 			// TODO: more auth method to support
 		}
diff --git a/cmd/root.go b/cmd/root.go
index aec1650..0c8fa77 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
-	"strconv"
 	"strings"
 	"syscall"
 
@@ -278,15 +277,15 @@ func runMain(cmd *cobra.Command, args []string) {
 	ctx, cancelFunc := context.WithCancel(context.Background())
 	go func() {
 		// Graceful shutdown
-		shutdownChan := make(chan os.Signal)
-		signal.Notify(shutdownChan, os.Interrupt, os.Kill)
+		shutdownChan := make(chan os.Signal, 1)
+		signal.Notify(shutdownChan, os.Interrupt, syscall.SIGTERM)
 		<-shutdownChan
 		logger.Info("shutting down gracefully...")
 		cancelFunc()
 	}()
 	go func() {
 		// Rule reload
-		reloadChan := make(chan os.Signal)
+		reloadChan := make(chan os.Signal, 1)
 		signal.Notify(reloadChan, syscall.SIGHUP)
 		for {
 			<-reloadChan
@@ -431,11 +430,3 @@ func envOrDefaultString(key, def string) string {
 	}
 	return def
 }
-
-func envOrDefaultBool(key string, def bool) bool {
-	if v := os.Getenv(key); v != "" {
-		b, _ := strconv.ParseBool(v)
-		return b
-	}
-	return def
-}
diff --git a/ruleset/builtins/geo/geo_loader.go b/ruleset/builtins/geo/geo_loader.go
index de5166a..8e16509 100644
--- a/ruleset/builtins/geo/geo_loader.go
+++ b/ruleset/builtins/geo/geo_loader.go
@@ -49,7 +49,7 @@ func (l *V2GeoLoader) shouldDownload(filename string) bool {
 	if os.IsNotExist(err) {
 		return true
 	}
-	dt := time.Now().Sub(info.ModTime())
+	dt := time.Since(info.ModTime())
 	if l.UpdateInterval == 0 {
 		return dt > geoDefaultUpdateInterval
 	} else {