add port check to onmessage

lib/io.js

@@ -36,7 +36,7 @@ module.exports = class IO {
   }
 
   onmessage (socket, buffer, rinfo) {
-    if (buffer.byteLength < 2) return
+    if (buffer.byteLength < 2 || !(rinfo.port > 0 && rinfo.port < 65536)) return
 
     const from = { id: null, host: rinfo.address, port: rinfo.port }
     const state = { start: 1, end: buffer.byteLength, buffer }