bugfix: add null terminators for packing SOA records

bin/dns-test.js

@@ -35,7 +35,7 @@ var hexdump = require('hexdump.js').hexdump;
 function testJsonAsync(nb) {
   var packet = dnsjs.write(JSON.parse(nb.toString('ascii')));
   var str = hexdump(packet);
-  console.log(str);
+  console.info(str);
   var json = dnsjs.parse(packet);
   if (json.error) {
     console.error(json);
@@ -43,7 +43,7 @@ function testJsonAsync(nb) {
     return;
   }
 
-  console.log("[OK] JSON -> binary -> JSON");
+  console.info("[OK] JSON -> binary -> JSON");
 
   if (!outname) {
     console.warn('');
@@ -54,7 +54,7 @@ function testJsonAsync(nb) {
     return;
   }
 
-  fs.writeFileSync(path.basename(filename).replace(path.extname(filename), '.bin'), packet, null);
+  fs.writeFileSync(outname, packet, null);
 }
 
 function testBinAsync(nb) {
@@ -66,6 +66,8 @@ function testBinAsync(nb) {
     return;
   }
   var bin2 = dnsjs.write(json);
+  //var debugname = outname || path.basename(filename);
+  //fs.writeFileSync(debugname.replace(path.extname(debugname), '.bin'), bin2, null);
   var json2 = dnsjs.parse(bin2);
   if (json2.error) {
     console.error(json2);
@@ -86,12 +88,22 @@ function testBinAsync(nb) {
     .replace(/,"cpcount":\d+/, '')
   );
   //json2 = JSON.parse(JSON.stringify(json2));
-  //console.log(json);
+  try {
-  //console.log(json2);
     assert.deepEqual(json, json2);
+  } catch(e) {
+    console.error('');
+    console.error('Original');
+    console.error(JSON.stringify(json, null, 2));
+    console.error('');
+    console.error('Converted');
+    console.error(JSON.stringify(json2, null, 2));
+    console.error('');
+    process.exit(422);
+    return;
+  }
 
-  console.log("[OK] binary -> JSON -> binary -> JSON");
+  console.info("[OK] binary -> JSON -> binary -> JSON");
-  console.log("(compression pointer support needs to be improved in order to support direct bin -> JSON -> bin testing)");
+  console.warn("(compression pointer support needs to be improved in order to support direct bin -> JSON -> bin testing)");
 
   if (!outname) {
     console.warn('');
@@ -102,7 +114,7 @@ function testBinAsync(nb) {
     return;
   }
 
-  fs.writeFileSync(path.basename(filename).replace(path.extname(filename), '.json'), JSON.stringify(json, null, 2), null);
+  fs.writeFileSync(outname, JSON.stringify(json, null, 2), null);
 }
 
 if ('json' === extname) {

dns.unpack-labels.js

@@ -46,6 +46,10 @@ exports.DNS_UNPACK_LABELS = function (ui8, ptr, q) {
 
     //str.length = 0; // fast empty array
     if (ui8.byteLength - total < len) {
+      //console.error('-1', ui8[total - 1]);
+      //console.error(' 0', ui8[total]);
+      //console.error(' 1', ui8[total + 1]);
+      //console.error(' 1', ui8[total + 2]);
       throw new Error(
         "Expected a string of length " + len
           + " but packet itself has " + (ui8.byteLength - total) + " bytes remaining"

packer/type.soa.js

@@ -1,6 +1,8 @@
 (function (exports) {
 'use strict';
 
+// http://www.zytrax.com/books/dns/ch8/soa.html
+
 // Value              Meaning/Use
 // Primary NS         Variable length. The name of the Primary Master for the domain. May be a label, pointer, or any combination
 // Admin MB           Variable length. The administrator's mailbox. May be a label, pointer, or any combination
@@ -10,8 +12,6 @@
 // Expiration Limit   Unsigned 32-bit integer
 // Minimum TTL        Unsigned 32-bit integer
 
-
-
 exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
   if(!record.name_server){
     throw new Error("no name server for SOA record");
@@ -23,16 +23,16 @@ exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
     throw new Error("no serial number for SOA record");
   }
   if(!record.ref){
-    throw new Error("no serial number for SOA record");
+    throw new Error("no refresh for SOA record");
   }
   if(!record.ret){
-    throw new Error("no serial number for SOA record");
+    throw new Error("no update retry for SOA record");
   }
   if(!record.ex){
-    throw new Error("no serial number for SOA record");
+    throw new Error("no expiry for SOA record");
   }
   if(!record.nx){
-    throw new Error("no serial number for SOA record");
+    throw new Error("no nxdomain for SOA record");
   }
 
   var soaLen = 20; // take into account sn, ref, ret, ex, and nx
@@ -40,9 +40,10 @@ exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
   var rdLenIndex = total;
   total += 2; // Save space for RDLENGTH
 
+  console.log('record.name_server', 1 + record.name_server.length, record.name_server);
   // pack name_server which is a sequence of labels
-  record.name_server.split('.').forEach(function(label){
+  record.name_server.split('.').forEach(function (label) {
-    soaLen += 1 + label.length;
+    soaLen += (1 + label.length);
 
     dv.setUint8(total, label.length, false);
     total += 1;
@@ -52,9 +53,14 @@ exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
       total += 1;
     });
   });
+  // must be terminated by null when not using write null
+  dv.setUint8(total, 0, false);
+  total += 1;
+  soaLen += 1;
 
+  console.log('record.email_addr', 1 + record.email_addr.length, record.email_addr);
   // pack email address which is a sequence of labels
-  record.email_addr.split('.').forEach(function (label){
+  record.email_addr.split('.').forEach(function (label) {
     soaLen += 1 + label.length;
 
     dv.setUint8(total, label.length, false);
@@ -65,6 +71,10 @@ exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
       total += 1;
     });
   });
+  // must be terminated by null when not using write null
+  dv.setUint8(total, 0, false);
+  total += 1;
+  soaLen += 1;
 
   // pack all 32-bit values
   dv.setUint32(total, parseInt(record.sn, 10), false);
@@ -79,6 +89,8 @@ exports.DNS_PACKER_TYPE_SOA = function (ab, dv, total, record) {
   total+=4;
 
   // RDLENGTH
+  console.log('rdAt', rdLenIndex);
+  console.log('soaLen (lables + 2 + 20)', soaLen);
   dv.setUint16(rdLenIndex, soaLen, false);
 
   return total;

parser/type.soa.js

@@ -18,27 +18,31 @@ exports.DNS_PARSER_TYPE_SOA = function (ab, packet, record) {
   var dv = new DataView(rdataAb);
 
   // we need this information for this parser
-  var cpcount = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).cpcount;
+  var labelInfo = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' });
-  var offset = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).byteLength;
+  var cpcount = labelInfo.cpcount;
-  var labels = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).labels;
+  var offset = labelInfo.byteLength;
+  var labels = labelInfo.labels;
 
   // Primary NS
-  record.name_server = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
+  record.name_server = labelInfo.name;
 
+  // TODO delete this commented out code after some testing
+  // (pretty sure it was unnecessary and it seemed to work on code with compression pointers just fine)
+  /*
   // if there exists compression pointers in the rdata
-  if (cpcount > 0){
+  if (cpcount > 0) {
     // do something awesome with compression pointers to get the email address
     // I need the length of all the data before the email address starts.
     // if there are compression pointers then there will be a byte to indicate the length of each label, the label,
     // then there will be a compression pointer to grab the longest label.
 
     var start = 2; // start or email_addr. take into account compression pointer and address length
-    for(var i = 0; i < labels.length; i++){
+    for (var i = 0; i < labels.length; i += 1) {
 
       // increase start by the label length. the +1 is to take into account the next label size byte
       start = start + labels[i].length + 1;
       // check for cpcount. 2 counts behind
-      if(parseInt(dv.getUint8(start - 2), 10) === 192){
+      if (parseInt(dv.getUint8(start - 2), 10) === 192) {
         record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + start ,{ byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
       }
     }
@@ -47,6 +51,9 @@ exports.DNS_PARSER_TYPE_SOA = function (ab, packet, record) {
 
     record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + offset, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
   }
+  */
+  record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + offset, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
+
   // Serial Number
   record.sn = dv.getUint32(dv.byteLength - 20, false);
   // Refresh Interval
@@ -58,9 +65,7 @@ exports.DNS_PARSER_TYPE_SOA = function (ab, packet, record) {
   // Minimum TTL
   record.nx = dv.getUint32(dv.byteLength - 4, false);
 
-
   return record;
-
 };
 
 }('undefined' !== typeof window ? window : exports));