Start to check device relay information

central_backend/src/constants.rs

@@ -36,6 +36,10 @@ impl SizeConstraint {
         let len = val.trim().len();
         len >= self.min && len <= self.max
     }
+
+    pub fn validate_usize(&self, val: usize) -> bool {
+        val >= self.min && val <= self.max
+    }
 }
 
 /// Backend static constraints