diff options
Diffstat (limited to 'netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm')
-rw-r--r-- | netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm | 221 |
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; +} |