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/* -*- 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;
}
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