auto-redirect: Fix nftables available check

redirect_linux.go

@@ -2,19 +2,17 @@ package tun
 
 import (
 	"context"
-	"net/netip"
-	"os"
-	"os/exec"
-	"runtime"
-	"time"
-
 	"github.com/sagernet/nftables"
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/control"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	M "github.com/sagernet/sing/common/metadata"
 	"github.com/sagernet/sing/common/x/list"
+	"net/netip"
+	"os"
+	"os/exec"
+	"runtime"
 
 	"go4.org/netipx"
 )
@@ -81,7 +79,8 @@ func NewAutoRedirect(options AutoRedirectOptions) (AutoRedirect, error) {
 		if r.useNFTables {
 			err = r.initializeNFTables()
 			if err != nil && err != os.ErrInvalid {
-				r.logger.Debug("device has no nftables support: ", err)
+				r.useNFTables = false
+				r.logger.Debug("missing nftables support: ", err)
 			}
 		}
 		if len(r.tunOptions.Inet4Address) > 0 {
@@ -131,7 +130,6 @@ func (r *autoRedirect) Start() error {
 		}
 		r.redirectServer = server
 	}
-	startAt := time.Now()
 	var err error
 	if r.useNFTables {
 		r.cleanupNFTables()
@@ -140,11 +138,7 @@ func (r *autoRedirect) Start() error {
 		r.cleanupIPTables()
 		err = r.setupIPTables()
 	}
-	if err != nil {
-		return err
-	}
-	r.logger.Debug("auto-redirect configured in ", time.Since(startAt))
-	return nil
+	return err
 }
 
 func (r *autoRedirect) Close() error {