added simple mDNS responder

This commit is contained in:
tigerbot 2017-05-23 16:23:43 -06:00
parent 73d3396609
commit 1f8e44947f
4 changed files with 152 additions and 0 deletions

View File

@ -73,6 +73,9 @@ function readConfigAndRun(args) {
if (!config.dns) {
config.dns = { modules: { name: 'proxy', port: 3053 } };
}
if (!config.mdns) {
config.mdns = { port: 5353, broadcast: '224.0.0.251', ttl: 300 };
}
if (!config.tcp) {
config.tcp = {};
}

View File

@ -225,5 +225,9 @@ module.exports.create = function (deps, config) {
}
}
if (!config.mdns.disabled) {
require('./mdns').start(deps, config);
}
return PromiseA.all(listenPromises);
};

144
lib/mdns.js Normal file
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@ -0,0 +1,144 @@
'use strict';
var PromiseA = require('bluebird');
var fs = PromiseA.promisifyAll(require('fs'));
var idFilename = require('path').join(__dirname, '..', 'var', 'mdns-id');
var queryName = '_cloud._tcp.local';
var randomId = {
get: function () {
return fs.readFileAsync(idFilename)
.catch(function (err) {
if (err.code !== 'ENOENT') {
return PromiseA.reject(err);
}
var id = require('crypto').randomBytes(5).toString('hex');
return randomId.set(id);
});
}
, set: function (value) {
return fs.writeFileAsync(idFilename, value)
.then(function () {
return value;
});
}
};
function createResponse(name, packet, ttl) {
var rpacket = {
header: {
id: packet.header.id
, qr: 1
, opcode: 0
, aa: 1
, tc: 0
, rd: 0
, ra: 0
, res1: 0
, res2: 0
, res3: 0
, rcode: 0
, }
, question: packet.question
, answer: []
, authority: []
, additional: []
, edns_options: []
};
rpacket.answer.push({
name: queryName
, typeName: 'PTR'
, ttl: ttl
, className: 'IN'
, data: name + '.' + queryName
});
var ifaces = require('./local-ip').find();
Object.keys(ifaces).forEach(function (iname) {
var iface = ifaces[iname];
iface.ipv4.forEach(function (addr) {
rpacket.additional.push({
name: name + '.local'
, typeName: 'A'
, ttl: ttl
, className: 'IN'
, address: addr.address
});
});
iface.ipv6.forEach(function (addr) {
rpacket.additional.push({
name: name + '.local'
, typeName: 'AAAA'
, ttl: ttl
, className: 'IN'
, address: addr.address
});
});
});
rpacket.additional.push({
name: name + '.' + queryName
, typeName: 'SRV'
, ttl: ttl
, className: 'IN'
, priority: 1
, weight: 0
, port: 443
, target: name + ".local"
});
rpacket.additional.push({
name: name + '._device-info._tcp.local'
, typeName: 'TXT'
, ttl: ttl
, className: 'IN'
, data: ["model=CloudHome1,1", "dappsvers=1"]
});
return require('dns-suite').DNSPacket.write(rpacket);
}
module.exports.start = function (deps, config) {
var socket = require('dgram').createSocket({ type: 'udp4', reuseAddr: true });
var dns = require('dns-suite');
socket.on('message', function (message, rinfo) {
// console.log('Received %d bytes from %s:%d', message.length, rinfo.address, rinfo.port);
var packet;
try {
packet = dns.DNSPacket.parse(message);
}
catch (er) {
// `dns-suite` actually errors on a lot of the packets floating around in our network,
// so don't bother logging any errors. (We still use `dns-suite` because unlike `dns-js`
// it can successfully craft the one packet we want to send.)
return;
}
// Only respond to queries.
if (packet.header.qr !== 0) {
return;
}
// Only respond if they were asking for cloud devices.
if (packet.question.length !== 1 || packet.question[0].name !== queryName) {
return;
}
randomId.get().then(function (name) {
var resp = createResponse(name, packet, config.mdns.ttl);
socket.send(resp, config.mdns.port, config.mdns.broadcast);
});
});
socket.bind(config.mdns.port, function () {
var addr = this.address();
console.log('bound on UDP %s:%d for mDNS', addr.address, addr.port);
socket.setBroadcast(true);
socket.addMembership(config.mdns.broadcast);
});
};

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@ -41,6 +41,7 @@
"bluebird": "^3.4.6",
"body-parser": "git+https://github.com/expressjs/body-parser.git#1.16.1",
"commander": "^2.9.0",
"dns-suite": "git+https://git@git.daplie.com:Daplie/dns-suite#v1",
"express": "git+https://github.com/expressjs/express.git#4.x",
"finalhandler": "^0.4.0",
"greenlock": "git+https://git.daplie.com/Daplie/node-greenlock.git#master",