[bug] initialize bitmask with persisted udp option

pkg/backend/api.go

@@ -148,6 +148,7 @@ type InitOpts struct {
 	ProviderOptions  *bitmask.ProviderOpts
 	SkipLaunch       bool
 	Obfs4            bool
+	UDP              bool
 	DisableAutostart bool
 	StartVPN         string
 }

pkg/backend/init.go

@@ -58,6 +58,7 @@ func initializeBitmask(errCh chan string, opts *InitOpts) {
 	bitmask.InitializeLogger()
 	ctx.cfg = config.ParseConfig()
 	setConfigOpts(opts, ctx.cfg)
+	ctx.UseUDP = ctx.cfg.UDP
 
 	err := pid.AcquirePID()
 	if err != nil {
@@ -92,6 +93,7 @@ func initializeBitmask(errCh chan string, opts *InitOpts) {
 	ctx.IsReady = true
 }
 
+// transfer initialization options from the config json to the config object
 func setConfigOpts(opts *InitOpts, conf *config.Config) {
 	conf.SkipLaunch = opts.SkipLaunch
 	if opts.StartVPN != "" {
@@ -104,6 +106,9 @@ func setConfigOpts(opts *InitOpts, conf *config.Config) {
 	if opts.Obfs4 {
 		conf.Obfs4 = opts.Obfs4
 	}
+	if opts.UDP {
+		conf.UDP = opts.UDP
+	}
 	if opts.DisableAutostart {
 		conf.DisableAutostart = opts.DisableAutostart
 	}

pkg/bitmask/init.go

@@ -95,6 +95,11 @@ func InitializeBitmask(conf *config.Config) (Bitmask, error) {
 		return nil, err
 	}
 
+	err = setUDP(b, conf)
+	if err != nil {
+		return nil, err
+	}
+
 	if !conf.SkipLaunch {
 		err := maybeStartVPN(b, conf)
 		if err != nil {
@@ -119,6 +124,18 @@ func setTransport(b Bitmask, conf *config.Config) error {
 	return nil
 }
 
+func setUDP(b Bitmask, conf *config.Config) error {
+	if conf.UDP {
+		log.Printf("Use UDP")
+		err := b.UseUDP(true)
+		if err != nil {
+			log.Printf("Error setting UDP: %v", err)
+			return err
+		}
+	}
+	return nil
+}
+
 func maybeStartVPN(b Bitmask, conf *config.Config) error {
 	if !conf.StartVPN {
 		return nil