1 files changed, 52 insertions, 0 deletions
diff --git a/testing/xpcshell/dns-packet/examples/tcp.js b/testing/xpcshell/dns-packet/examples/tcp.js
new file mode 100644
index 0000000000..b25c2c41cb
--- /dev/null
+++ b/testing/xpcshell/dns-packet/examples/tcp.js
@@ -0,0 +1,52 @@
+'use strict'
+
+const dnsPacket = require('..')
+const net = require('net')
+
+var response = null
+var expectedLength = 0
+
+function getRandomInt (min, max) {
+  return Math.floor(Math.random() * (max - min + 1)) + min
+}
+
+const buf = dnsPacket.streamEncode({
+  type: 'query',
+  id: getRandomInt(1, 65534),
+  flags: dnsPacket.RECURSION_DESIRED,
+  questions: [{
+    type: 'A',
+    name: 'google.com'
+  }]
+})
+
+const client = new net.Socket()
+client.connect(53, '8.8.8.8', function () {
+  console.log('Connected')
+  client.write(buf)
+})
+
+client.on('data', function (data) {
+  console.log('Received response: %d bytes', data.byteLength)
+  if (response == null) {
+    if (data.byteLength > 1) {
+      const plen = data.readUInt16BE(0)
+      expectedLength = plen
+      if (plen < 12) {
+        throw new Error('below DNS minimum packet length')
+      }
+      response = Buffer.from(data)
+    }
+  } else {
+    response = Buffer.concat([response, data])
+  }
+
+  if (response.byteLength >= expectedLength) {
+    console.log(dnsPacket.streamDecode(response))
+    client.destroy()
+  }
+})
+
+client.on('close', function () {
+  console.log('Connection closed')
+})