fix(manager, stub, util): enhance error handling and logging consistency

proxy/manager.go

@@ -20,6 +20,8 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 )
 
+const errUnsupportedProtoFmt = "unsupported protocol: %s"
+
 // Target represents a proxy target with its address and port
 type Target struct {
 	Address string
@@ -74,13 +76,14 @@ func (cw *countingWriter) Write(p []byte) (int, error) {
 	n, err := cw.w.Write(p)
 	if n > 0 {
 		if cw.pm != nil && cw.pm.asyncBytes && cw.ent != nil {
-			if cw.proto == "tcp" {
+			switch cw.proto {
+			case "tcp":
 				if cw.out {
 					cw.ent.bytesOutTCP.Add(uint64(n))
 				} else {
 					cw.ent.bytesInTCP.Add(uint64(n))
 				}
-			} else if cw.proto == "udp" {
+			case "udp":
 				if cw.out {
 					cw.ent.bytesOutUDP.Add(uint64(n))
 				} else {
@@ -207,7 +210,7 @@ func (pm *ProxyManager) AddTarget(proto, listenIP string, port int, targetAddr s
 		}
 		pm.udpTargets[listenIP][port] = targetAddr
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 
 	if pm.running {
@@ -256,7 +259,7 @@ func (pm *ProxyManager) RemoveTarget(proto, listenIP string, port int) error {
 			return fmt.Errorf("target not found: %s:%d", listenIP, port)
 		}
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 	return nil
 }
@@ -443,7 +446,7 @@ func (pm *ProxyManager) startTarget(proto, listenIP string, port int, targetAddr
 		go pm.handleUDPProxy(conn, targetAddr)
 
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 
 	logger.Info("Started %s proxy to %s", proto, targetAddr)

stub.go

@@ -8,25 +8,27 @@ import (
 )
 
 func setupClientsNative(client *websocket.Client, host string) {
-	return // This function is not implemented for non-Linux systems.
+	_ = client
+	_ = host
+	// No-op for non-Linux systems
 }
 
 func closeWgServiceNative() {
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsOnConnectNative() {
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsHandleNewtConnectionNative(publicKey, endpoint string) {
+	_ = publicKey
+	_ = endpoint
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsAddProxyTargetNative(pm *proxy.ProxyManager, tunnelIp string) {
+	_ = pm
+	_ = tunnelIp
 	// No-op for non-Linux systems
-	return
 }

util.go

@@ -25,6 +25,8 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack"
 )
 
+const msgHealthFileWriteFailed = "Failed to write health file: %v"
+
 func fixKey(key string) string {
 	// Remove any whitespace
 	key = strings.TrimSpace(key)
@@ -177,7 +179,7 @@ func pingWithRetry(tnet *netstack.Net, dst string, timeout time.Duration) (stopC
 		if healthFile != "" {
 			err := os.WriteFile(healthFile, []byte("ok"), 0644)
 			if err != nil {
-				logger.Warn("Failed to write health file: %v", err)
+				logger.Warn(msgHealthFileWriteFailed, err)
 			}
 		}
 		return stopChan, nil
@@ -218,11 +220,11 @@ func pingWithRetry(tnet *netstack.Net, dst string, timeout time.Duration) (stopC
 					if healthFile != "" {
 						err := os.WriteFile(healthFile, []byte("ok"), 0644)
 						if err != nil {
-							logger.Warn("Failed to write health file: %v", err)
+							logger.Warn(msgHealthFileWriteFailed, err)
 						}
 					}
-					return
 				}
+			case <-pingStopChan:
 			}
 		}
 	}()
@@ -476,7 +478,8 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 			continue
 		}
 
-		if action == "add" {
+		switch action {
+		case "add":
 			target := parts[1] + ":" + parts[2]
 
 			// Call updown script if provided
@@ -502,7 +505,7 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 			// Add the new target
 			pm.AddTarget(proto, tunnelIP, port, processedTarget)
 
-		} else if action == "remove" {
+		case "remove":
 			logger.Info("Removing target with port %d", port)
 
 			target := parts[1] + ":" + parts[2]
@@ -520,6 +523,8 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 				logger.Error("Failed to remove target: %v", err)
 				return err
 			}
+		default:
+			logger.Info("Unknown action: %s", action)
 		}
 	}