1.1 --- a/src/app.js Wed Aug 13 21:01:00 2014 +0200
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,212 +0,0 @@
1.4 -#! /usr/bin/env nodejs
1.5 -//
1.6 -// mDNSGw - Zero Configuration DNS Gateway for Mesh Networks
1.7 -// Copyright © 2014 Michael Schloh von Bennewitz <michael@schloh.com>
1.8 -//
1.9 -// Permission to use, copy, modify, and/or distribute this software for
1.10 -// any purpose with or without fee is hereby granted, provided that the
1.11 -// above copyright notice and this permission notice appear in all copies.
1.12 -//
1.13 -// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
1.14 -// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
1.15 -// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
1.16 -// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
1.17 -// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
1.18 -// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
1.19 -// ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
1.20 -// THIS SOFTWARE.
1.21 -//
1.22 -// This file is part of mDNSGw, a Zero configuration DNS gateway
1.23 -// which can be found at http://dev.europalab.com/mdnsgw/
1.24 -//
1.25 -// app.js: ECMA JavaScript implementation
1.26 -//
1.27 -
1.28 -/***********************************************************
1.29 -| ____ _ _ ____ ____ |
1.30 -| _ __ ___ | _ \| \ | / ___| / ___|_ __ |
1.31 -| | '_ ` _ \| | | | \| \___ \| | _\ \ /\ / / |
1.32 -| | | | | | | |_| | |\ |___) | |_| |\ V V / |
1.33 -| |_| |_| |_|____/|_| \_|____/ \____| \_/\_/ |
1.34 -| |
1.35 -| Requirements: Redis server with standard configuration |
1.36 -| NodeJS and NPM modules (see package.json) |
1.37 -| |
1.38 -| Execute: To start this application, launch it with the |
1.39 -| script named fork.js: $ ./fork.js |
1.40 -| |
1.41 -| Support: http://list.europalab.com/mailman/mdnsgs/ |
1.42 -| |
1.43 -***********************************************************/
1.44 -
1.45 -// import module dependencies
1.46 -var mdnsinst = require('mdns');
1.47 -var redisdat = require('redis');
1.48 -var nameinst = require('native-dns');
1.49 -
1.50 -
1.51 -// install POSIX signal handlers
1.52 -process.on('SIGUSR2', function() {
1.53 - console.log('SIGUSR2: Dumping mDNSGw entries at', Date());
1.54 - rediscli.hgetall('hostnames', function (error, object) {console.dir(object);});
1.55 -});
1.56 -process.on('SIGHUP', function() {
1.57 - console.log('SIGHUP: Cleared all database entries at', Date());
1.58 - cleardb();
1.59 -});
1.60 -
1.61 -// instantiate a new redis client
1.62 -// http://www.rediscookbook.org/
1.63 -var rediscli = redisdat.createClient();
1.64 -rediscli.on('error', function (error) {
1.65 - console.log('Error ' + error);
1.66 -});
1.67 -
1.68 -// clear mDNS service keys
1.69 -function cleardb () {
1.70 - rediscli.del('hostnames');
1.71 - // this is not working unfortunately for the loop
1.72 - rediscli.keys('*', function (error, replies) {
1.73 - replies.forEach(function (reply, ident) {
1.74 - rediscli.del(reply, function (error, value) {
1.75 - if (error) throw(error);
1.76 - });
1.77 - });
1.78 - });
1.79 -}
1.80 -
1.81 -// scan all advertised mDNS service types
1.82 -cleardb(); // clear old data first
1.83 -var browsall = mdnsinst.browseThemAll();
1.84 -browsall.on('serviceUp', function(service) {
1.85 - // iterate through hosts and watch accordingly
1.86 - if (service.type.name.match(/^[a-zA-Z0-9\-]+$/)) { // mdns module hack
1.87 - if (service.type.protocol == 'tcp') {
1.88 - var browserv = mdnsinst.createBrowser(mdnsinst.tcp(service.type.name));
1.89 - }
1.90 - else if (service.type.protocol == 'udp') {
1.91 - var browserv = mdnsinst.createBrowser(mdnsinst.udp(service.type.name));
1.92 - }
1.93 - else if (service.type.protocol == 'sctp') {
1.94 - var browserv = mdnsinst.createBrowser(mdnsinst.sctp(service.type.name));
1.95 - }
1.96 - else throw(error);
1.97 -
1.98 - // common logic for all transports (TCP, UDP, SCTP, etcetera)
1.99 - browserv.on('serviceUp', function(service) {
1.100 - //console.log('service up: ', service);
1.101 - //{interfaceIndex: 2, type: {name: 'ssh', protocol: 'tcp', subtypes: [], fullyQualified: true}, replyDomain: 'local.', flags: 2, name: 'hostname-mich', networkInterface: 'eth0', fullname: 'hostname-mich._ssh._tcp.local.', host: 'hostname-mich.local.', port: 22, addresses: ['192.168.1.50']}
1.102 -
1.103 - // insert one or more IP addresses for each hostname.local.
1.104 - rediscli.hset('hostnames', service.host.replace(/\.$/, ''), service.addresses);
1.105 - });
1.106 - browserv.on('serviceDown', function(service) {
1.107 - console.log('service down: ', service);
1.108 - //FIXME: still need to selectively remove hosts
1.109 - });
1.110 - browserv.on('serviceChanged', function(service) {
1.111 - console.log('service changed: ', service);
1.112 - //FIXME: still need to selectively update hosts
1.113 - });
1.114 - browserv.start();
1.115 - }
1.116 -});
1.117 -browsall.start();
1.118 -
1.119 -// instantiate a new DNS server
1.120 -var nameserv = nameinst.createServer();
1.121 -
1.122 -nameserv.on('request', function (request, response) {
1.123 - //console.log(request)
1.124 -
1.125 - // ensure that requested hostname is present
1.126 - rediscli.hget('hostnames', request.question[0].name, function (error, value) {
1.127 - // handle unexpected errors
1.128 - if (error) throw(error);
1.129 -
1.130 - if (value) { // the db succeeded in finding a match
1.131 - // populate the DNS response with the chosen hostname
1.132 - rediscli.hkeys('hostnames', function (error, replies) {
1.133 - replies.forEach(function (host, index) {
1.134 - if (request.question[0].name == host) {
1.135 - rediscli.hget('hostnames', host, function (error, value) {
1.136 - // handle unexpected errors
1.137 - if (error) throw(error);
1.138 -
1.139 - // FIXME: still must handle multihomed hosts
1.140 - //// a host might have more than one address
1.141 - //value.forEach(function (addr, iter)
1.142 - // set the nameserver address
1.143 - response.answer.push(nameinst.A({
1.144 - name: host,
1.145 - address: value,
1.146 - ttl: 600,
1.147 - }));
1.148 - response.send();
1.149 - });
1.150 - }
1.151 - });
1.152 - });
1.153 - }
1.154 - else {
1.155 - response.answer.push(nameinst.A({
1.156 - name: request.question[0].name,
1.157 - address: '127.0.0.1',
1.158 - ttl: 600,
1.159 - }));
1.160 - response.send();
1.161 - }
1.162 - });
1.163 -});
1.164 -
1.165 -// DNS error handler logic
1.166 -nameserv.on('error', function (err, buff, req, res) {
1.167 - console.log('DNS problem: ', err.stack);
1.168 -});
1.169 -
1.170 -//// debug process user
1.171 -//console.log('Start.');
1.172 -//console.log(process.env.USER);
1.173 -//console.log(process.env.SUDO_USER);
1.174 -//console.log('Done.');
1.175 -//
1.176 -// <1024 must run privileged
1.177 -var nudpport = 53; // default DNS
1.178 -if (nudpport < 1024 && process.getuid() !== 0) {
1.179 - //console.log('Serving on port <1024 from an unprivileged user.\nChange to root if using a privileged port number.')
1.180 - throw new Error('Serving on port <1024 from an unprivileged user.')
1.181 -}
1.182 -
1.183 -// start the DNS process
1.184 -nameserv.serve(nudpport, function () {
1.185 - try {
1.186 - console.log('Starting mDNSGw on', Date());
1.187 - process.stdout.write('Old UID: ' + process.getuid() + ', Old GID: ' + process.getgid() + '... ');
1.188 - process.umask('0644');
1.189 - process.setgid('daemon');
1.190 - if (process.env.SUDO_USER)
1.191 - process.setuid(process.env.SUDO_USER);
1.192 - else
1.193 - process.setuid('daemon');
1.194 - console.log('New UID: ' + process.getuid() + ', New GID: ' + process.getgid());
1.195 - } catch (err) {
1.196 - console.log('Cowardly refusing to keep the process alive as root.');
1.197 - process.exit(1);
1.198 - }
1.199 -});
1.200 -
1.201 -//// debug print all key and value database entries
1.202 -//rediscli.hgetall('hostnames', function (error, object) {console.dir(object);});
1.203 -
1.204 -//// display stored mDNS service data entries
1.205 -//rediscli.hkeys('hostnames', function (error, replies) {
1.206 -// console.log(replies.length + ' replies:');
1.207 -// replies.forEach(function (reply, ident) {
1.208 -// console.log(' ' + ident + ': ' + reply);
1.209 -// });
1.210 -//});
1.211 -
1.212 -//// block executes on program termination
1.213 -//rediscli.quit(); // cleanup db connection
1.214 -//browserv.stop(); // zombie scope too bad
1.215 -//browsall.stop();
