show legacy warning only once

proxy/vmess/validator.go

@@ -42,6 +42,8 @@ type TimedUserValidator struct {
 	behaviorFused bool
 
 	aeadDecoderHolder *aead.AuthIDDecoderHolder
+
+	legacyWarnShown bool
 }
 
 type indexTimePair struct {
@@ -247,6 +249,17 @@ func (v *TimedUserValidator) BurnTaintFuse(userHash []byte) error {
 	return ErrNotFound
 }
 
+/* ShouldShowLegacyWarn will return whether a Legacy Warning should be shown
+Not guaranteed to only return true once for every inbound, but it is okay.
+*/
+func (v *TimedUserValidator) ShouldShowLegacyWarn() bool {
+	if v.legacyWarnShown {
+		return false
+	}
+	v.legacyWarnShown = true
+	return true
+}
+
 var ErrNotFound = newError("Not Found")
 
 var ErrTainted = newError("ErrTainted")