Adds an option to disable system-wide proxy

cmd/spoof-dpi/main.go

@@ -39,8 +39,10 @@ func main() {
 		util.PrintColoredBanner()
 	}
 
-	if err := util.SetOsProxy(*config.Port); err != nil {
-		log.Fatal(err)
+	if *config.SystemProxy {
+		if err := util.SetOsProxy(*config.Port); err != nil {
+			log.Fatal(err)
+		}
 	}
 
 	go pxy.Start()
@@ -63,7 +65,10 @@ func main() {
 	}()
 
 	<-done
-	if err := util.UnsetOsProxy(); err != nil {
-		log.Fatal(err)
+
+	if *config.SystemProxy {
+		if err := util.UnsetOsProxy(); err != nil {
+			log.Fatal(err)
+		}
 	}
 }

util/config.go

@@ -19,6 +19,7 @@ type Config struct {
 	EnableDoh      *bool
 	Debug          *bool
 	NoBanner       *bool
+	SystemProxy  *bool
 	Timeout        *int
 	AllowedPattern *regexp.Regexp
 	AllowedUrls    *regexp.Regexp
@@ -54,6 +55,7 @@ func ParseArgs() {
 	config.EnableDoh = flag.Bool("enable-doh", false, "enable 'dns over https'")
 	config.Debug = flag.Bool("debug", false, "enable debug output")
 	config.NoBanner = flag.Bool("no-banner", false, "disable banner")
+	config.SystemProxy = flag.Bool("system-proxy", false, "enable system-wide proxy")
 	config.Timeout = flag.Int("timeout", 0, "timeout in milliseconds. no timeout when not given")
 	config.WindowSize = flag.Int("window-size", 0, `chunk size, in number of bytes, for fragmented client hello,
 try lower values if the default value doesn't bypass the DPI;