1 files changed, 221 insertions, 0 deletions
diff --git a/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm b/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm
new file mode 100644
index 000000000..ba0072a50
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm
@@ -0,0 +1,221 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DNSResourceRecord'];
+
+const { utils: Cu } = Components;
+
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://gre/modules/DataReader.jsm');
+Cu.import('resource://gre/modules/DataWriter.jsm');
+Cu.import('resource://gre/modules/DNSRecord.jsm');
+Cu.import('resource://gre/modules/DNSTypes.jsm');
+
+function debug(msg) {
+  Services.console.logStringMessage('MulticastDNS: ' + msg);
+}
+
+const DNS_RESOURCE_RECORD_DEFAULT_TTL = 120; // 120 seconds
+
+class DNSResourceRecord extends DNSRecord {
+  constructor(properties = {}) {
+    super(properties);
+
+    this.ttl  = properties.ttl  || DNS_RESOURCE_RECORD_DEFAULT_TTL;
+    this.data = properties.data || {};
+  }
+
+  static parseFromPacketReader(reader) {
+    let record = super.parseFromPacketReader(reader);
+
+    let ttl        = reader.getValue(4);
+    let recordData = reader.getBytes(reader.getValue(2));
+    let packetData = reader.data;
+
+    let data;
+
+    switch (record.recordType) {
+      case DNS_RECORD_TYPES.A:
+        data = _parseA(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.PTR:
+        data = _parsePTR(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.TXT:
+        data = _parseTXT(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.SRV:
+        data = _parseSRV(recordData, packetData);
+        break;
+      default:
+        data = null;
+        break;
+    }
+
+    record.ttl  = ttl;
+    record.data = data;
+
+    return record;
+  }
+
+  serialize() {
+    let writer = new DataWriter(super.serialize());
+
+    // Write `ttl` (4 bytes)
+    writer.putValue(this.ttl, 4);
+
+    let data;
+
+    switch (this.recordType) {
+      case DNS_RECORD_TYPES.A:
+        data = _serializeA(this.data);
+        break;
+      case DNS_RECORD_TYPES.PTR:
+        data = _serializePTR(this.data);
+        break;
+      case DNS_RECORD_TYPES.TXT:
+        data = _serializeTXT(this.data);
+        break;
+      case DNS_RECORD_TYPES.SRV:
+        data = _serializeSRV(this.data);
+        break;
+      default:
+        data = new Uint8Array();
+        break;
+    }
+
+    // Write `data` length.
+    writer.putValue(data.length, 2);
+
+    // Write `data` (ends with trailing 0x00 byte)
+    writer.putBytes(data);
+
+    return writer.data;
+  }
+
+  toJSON() {
+    return JSON.stringify(this.toJSONObject());
+  }
+
+  toJSONObject() {
+    let result = super.toJSONObject();
+    result.ttl = this.ttl;
+    result.data = this.data;
+    return result;
+  }
+}
+
+/**
+ * @private
+ */
+function _parseA(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let parts = [];
+  for (let i = 0; i < 4; i++) {
+    parts.push(reader.getValue(1));
+  }
+
+  return parts.join('.');
+}
+
+/**
+ * @private
+ */
+function _parsePTR(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  return reader.getLabel(packetData);
+}
+
+/**
+ * @private
+ */
+function _parseTXT(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let result = {};
+
+  let label = reader.getLabel(packetData);
+  if (label.length > 0) {
+    let parts = label.split('.');
+    parts.forEach((part) => {
+      let [name] = part.split('=', 1);
+      let value = part.substr(name.length + 1);
+      result[name] = value;
+    });
+  }
+
+  return result;
+}
+
+/**
+ * @private
+ */
+function _parseSRV(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let priority = reader.getValue(2);
+  let weight   = reader.getValue(2);
+  let port     = reader.getValue(2);
+  let target   = reader.getLabel(packetData);
+
+  return { priority, weight, port, target };
+}
+
+/**
+ * @private
+ */
+function _serializeA(data) {
+  let writer = new DataWriter();
+
+  let parts = data.split('.');
+  for (let i = 0; i < 4; i++) {
+    writer.putValue(parseInt(parts[i], 10) || 0);
+  }
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializePTR(data) {
+  let writer = new DataWriter();
+
+  writer.putLabel(data);
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializeTXT(data) {
+  let writer = new DataWriter();
+
+  for (let name in data) {
+    writer.putLengthString(name + '=' + data[name]);
+  }
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializeSRV(data) {
+  let writer = new DataWriter();
+
+  writer.putValue(data.priority || 0, 2);
+  writer.putValue(data.weight   || 0, 2);
+  writer.putValue(data.port     || 0, 2);
+  writer.putLabel(data.target);
+
+  return writer.data;
+}