split listening settings from inbound proxies and apply context

common/protocol/context.go

@@ -0,0 +1,23 @@
+package protocol
+
+import (
+	"context"
+)
+
+type key int
+
+const (
+	userKey key = iota
+)
+
+func ContextWithUser(ctx context.Context, user *User) context.Context {
+	return context.WithValue(ctx, userKey, user)
+}
+
+func UserFromContext(ctx context.Context) *User {
+	v := ctx.Value(userKey)
+	if v == nil {
+		return nil
+	}
+	return v.(*User)
+}