mDNSGw Sources: comparison src/app.js

comparison: src/app.js

src/app.js

changeset 3: 42e83b3431d9
parent 0: eb6d4ce6fd78

equal deleted inserted replaced

-:2efff1978918
+:34809b28628a
 var mdnsinst = require('mdns');
 var redisdat = require('redis');
 var nameinst = require('native-dns');
+// install POSIX signal handlers
+process.on('SIGUSR2', function() {
+console.log('SIGUSR2: Dumping mDNSGw entries at', Date());
+rediscli.hgetall('hostnames', function (error, object) {console.dir(object);});
+});
+process.on('SIGHUP', function() {
+console.log('SIGHUP: Cleared all database entries at', Date());
+cleardb();
+});
 // instantiate a new redis client
 // http://www.rediscookbook.org/
 var rediscli = redisdat.createClient();
 rediscli.on('error', function (error) {
 console.log('Error ' + error);
 });
 // clear mDNS service keys
-rediscli.del('hostnames');
+function cleardb () {
-// this is not working unfortunately for the loop
+rediscli.del('hostnames');
-rediscli.keys('*', function (error, replies) {
+// this is not working unfortunately for the loop
-replies.forEach(function (reply, ident) {
+rediscli.keys('*', function (error, replies) {
-rediscli.del(reply, function (error, value) {
+replies.forEach(function (reply, ident) {
-if (error) throw(error);
+rediscli.del(reply, function (error, value) {
+if (error) throw(error);
+});
 });
 });
-});
+}
 // scan all advertised mDNS service types
+cleardb(); // clear old data first
 var browsall = mdnsinst.browseThemAll();
 browsall.on('serviceUp', function(service) {
 // iterate through hosts and watch accordingly
 if (service.type.name.match(/^[a-zA-Z0-9\-]+$/)) { // mdns module hack
 if (service.type.protocol == 'tcp') {
 // insert one or more IP addresses for each hostname.local.
 rediscli.hset('hostnames', service.host.replace(/\.$/, ''), service.addresses);
 });
 browserv.on('serviceDown', function(service) {
-//console.log('service down: ', service);
+console.log('service down: ', service);
 //FIXME: still need to selectively remove hosts
+});
+browserv.on('serviceChanged', function(service) {
+console.log('service changed: ', service);
+//FIXME: still need to selectively update hosts
 });
 browserv.start();
 }
 });
 browsall.start();
 // DNS error handler logic
 nameserv.on('error', function (err, buff, req, res) {
 console.log('DNS problem: ', err.stack);
 });
-nameserv.serve(15353);
+//// debug process user
+//console.log('Start.');
+//console.log(process.env.USER);
+//console.log(process.env.SUDO_USER);
+//console.log('Done.');
+//
+// <1024 must run privileged
+var nudpport = 53; // default DNS
+if (nudpport < 1024 && process.getuid() !== 0) {
+//console.log('Serving on port <1024 from an unprivileged user.\nChange to root if using a privileged port number.')
+throw new Error('Serving on port <1024 from an unprivileged user.')
+}
+// start the DNS process
+nameserv.serve(nudpport, function () {
+try {
+console.log('Starting mDNSGw on', Date());
+process.stdout.write('Old UID: ' + process.getuid() + ', Old GID: ' + process.getgid() + '... ');
+process.umask('0644');
+process.setgid('daemon');
+if (process.env.SUDO_USER)
+process.setuid(process.env.SUDO_USER);
+else
+process.setuid('daemon');
+console.log('New UID: ' + process.getuid() + ', New GID: ' + process.getgid());
+} catch (err) {
+console.log('Cowardly refusing to keep the process alive as root.');
+process.exit(1);
+}
+});
 //// debug print all key and value database entries
 //rediscli.hgetall('hostnames', function (error, object) {console.dir(object);});
 //// display stored mDNS service data entries