handle bad packet more correctly

lib/tcpd.js

@@ -27,9 +27,10 @@ module.exports.create = function (cli, dnsd) {
 
         // TODO pad two bytes for lengths
         dnsd.onMessage(nb, function (err, newAb, dbgmsg) {
-          var lenbuf = Buffer.from([ newAb.length >> 8, newAb.length & 255 ]);
           // TODO XXX generate legit error packet
           if (err) { console.error("Error", err); c.end(); return; }
+
+          var lenbuf = Buffer.from([ newAb.length >> 8, newAb.length & 255 ]);
           console.log('TCP ' + dbgmsg);
 
           c.write(lenbuf);
@@ -53,10 +54,11 @@ module.exports.create = function (cli, dnsd) {
         process.exit(0);
       }
       console.error("TCP Server Error:");
-      console.error(err);
+      console.error(err.stack);
       tcpServer.close(function () {
         setTimeout(runTcp, 1000);
       });
+      //throw new Error(err);
     });
 
     tcpServer.listen(cli.port, function () {

lib/udpd.js

@@ -1,58 +1,66 @@
 'use strict';
 
 module.exports.create = function (cli, dnsd) {
-  var server = require('dgram').createSocket({
-    type: cli.udp6 ? 'udp6' : 'udp4'
-  , reuseAddr: true
-  });
-  server.bind({
-    port: cli.port
-  , address: cli.address
-  });
-
-  var handlers = {};
-  handlers.onError = function (err) {
-    if ('EACCES' === err.code) {
-      console.error("");
-      console.error("EACCES: Couldn't bind to port. You probably need to use sudo, authbind, or setcap.");
-      console.error("");
-      process.exit(123);
-      return;
-    }
-    console.error("error:", err.stack);
-    server.close();
-  };
-
-  handlers.onMessage = function (nb, rinfo) {
-    //console.log('[DEBUG] got a UDP message', nb.length);
-    //console.log(nb.toString('hex'));
-
-    dnsd.onMessage(nb, function (err, newAb, dbgmsg) {
-      // TODO send legit error message
-      if (err) { server.send(Buffer.from([0x00])); return; }
-      server.send(newAb, rinfo.port, rinfo.address, function () {
-        console.log(dbgmsg, rinfo.port, rinfo.address);
-      });
+  function runUdp() {
+    var server = require('dgram').createSocket({
+      type: cli.udp6 ? 'udp6' : 'udp4'
+    , reuseAddr: true
+    });
+    server.bind({
+      port: cli.port
+    , address: cli.address
     });
-  };
 
-  handlers.onListening = function () {
-    /*jshint validthis:true*/
-    var server = this;
+    var handlers = {};
+    handlers.onError = function (err) {
+      if ('EACCES' === err.code) {
+        console.error("");
+        console.error("EACCES: Couldn't bind to port. You probably need to use sudo, authbind, or setcap.");
+        console.error("");
+        process.exit(123);
+        return;
+      }
+      console.error("UDP Server Error:");
+      console.error(err.stack);
+      server.close(function () {
+        setTimeout(runUdp, 1000);
+      });
+      //throw new Error(err);
+    };
 
-    if (cli.mdns || '224.0.0.251' === cli.nameserver) {
-      server.setBroadcast(true);
-      server.addMembership(cli.nameserver);
-    }
+    handlers.onMessage = function (nb, rinfo) {
+      //console.log('[DEBUG] got a UDP message', nb.length);
+      //console.log(nb.toString('hex'));
 
-    console.log('');
-    console.log('Bound and Listening:');
-    console.log(server.address().address + '#' + server.address().port + ' (' + server.type + ')');
-  };
+      dnsd.onMessage(nb, function (err, newAb, dbgmsg) {
+        // TODO send legit error message
+        if (err) { server.send(Buffer.from([0x00]), rinfo.port, rinfo.address); return; }
+        server.send(newAb, rinfo.port, rinfo.address, function () {
+          console.log('[dnsd.onMessage] ' + dbgmsg, rinfo.port, rinfo.address);
+        });
+      });
+    };
 
-  server.on('error', handlers.onError);
-  server.on('message', handlers.onMessage);
-  server.on('listening', handlers.onListening);
+    handlers.onListening = function () {
+      /*jshint validthis:true*/
+      var server = this;
 
-  return server;
+      if (cli.mdns || '224.0.0.251' === cli.nameserver) {
+        server.setBroadcast(true);
+        server.addMembership(cli.nameserver);
+      }
+
+      console.log('');
+      console.log('Bound and Listening:');
+      console.log(server.address().address + '#' + server.address().port + ' (' + server.type + ')');
+    };
+
+    server.on('error', handlers.onError);
+    server.on('message', handlers.onMessage);
+    server.on('listening', handlers.onListening);
+
+    return server;
+  }
+
+  return runUdp();
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "digd.js",
-  "version": "1.2.1",
+  "version": "1.2.2",
   "description": "A lightweight DNS / mDNS daemon (server) for creating and capturing DNS and mDNS query and response packets to disk as binary and/or JSON. Options are similar to the Unix dig command.",
   "main": "bin/digd.js",
   "homepage": "https://git.coolaj86.com/coolaj86/digd.js",