add support for modular rdata parsing

dns.rdata.parse.js

@@ -0,0 +1,44 @@
+(function (exports) {
+'use strict';
+
+var classes = exports.DNS_CLASSES || require('./dns.classes.js').DNS_CLASSES;
+var types = exports.DNS_TYPES || require('./dns.types.js').DNS_TYPES;
+
+exports.DNS_RDATA_PARSE = function (ab, packet, record) {
+  // ab is needed if the rdata makes use of compression pointers
+  // packet is given for convenience
+  var parser;
+
+  record.className = classes[record.class];
+  if (!record.className) {
+    throw new Error("Support for DNS Class " + record.class.toString(16) + "(" + record.class + ")"
+      + " is not implemented yet. Open an issue if you actually need support"
+      + " (i.e. you're not working with a malformed packet)"
+    );
+  }
+
+  record.typeName = types[record.type];
+  if (!record.typeName) {
+    throw new Error("Support for DNS Type " + record.type.toString(16) + "(" + record.type + ")"
+      + " is not implemented yet. Open an issue if you actually need support"
+      + " (i.e. you're not working with a malformed packet)"
+    );
+  }
+
+  try {
+    parser = exports['DNS_TYPE_' + record.typeName]
+      || require('./dns.type.' + record.typeName.toLowerCase());
+  }
+  catch (e) { /*console.error(e)*/ }
+
+  if (!parser) {
+    throw new Error("Parser for DNS Type " + record.typeName + " could not be loaded."
+      + " Did you include <script src=\"dns.type." + record.typeName.toLowerCase() + ".js\"></script> ?"
+      + " (or perhaps we plan to implement it and haven't yet - in which case please open an issue)"
+    );
+  }
+
+  return parser(ab, packet, record);
+};
+
+}('undefined' !== typeof window ? window : exports));

pure-parser-cli.js

@@ -26,12 +26,27 @@ fs.readFileAsync(filename, null).then(function (nb) {
   //
   // other reference impl
   //
-  console.log(require('dns-js').DNSPacket.parse(nb));
+  //console.log(require('dns-js').DNSPacket.parse(nb));
 
   // nb is a Uint8Array (ArrayBufferView) for nb.buffer
   // nb.buffer is the actual ArrayBuffer
   var packet = pdns.unpack(nb.buffer);
 
+  function tryParseRdata(record) {
+    record.data = null;
+    record.error = null;
+
+    try {
+      record.data = pdns.unpackRdata(nb.buffer, packet, record);
+    } catch (e) {
+      record.error = e;
+    }
+  }
+
+  packet.answers.forEach(tryParseRdata);
+  packet.authority.forEach(tryParseRdata);
+  packet.additional.forEach(tryParseRdata);
+
   console.log('[packet]', nb.byteLength, 'bytes:');
   console.log(packet);
 });

pure-parser.js

@@ -26,23 +26,6 @@ pdns.unpackHeader = function (i) {
   return header;
 };
 
-pdns.packHeader = function(h) {
-  var val = 0;
-
-  val += (h.qr     << 15) & 0x8000;
-  val += (h.opcode << 11) & 0x7800;
-  val += (h.aa     << 10) &  0x400;
-  val += (h.tc     <<  9) &  0x200;
-  val += (h.rd     <<  8) &  0x100;
-  val += (h.ra     <<  7) &   0x80;
-  val += (h.res1   <<  6) &   0x40;
-  val += (h.res2   <<  5) &   0x20;
-  val += (h.res3   <<  4) &   0x10;
-  val += h.rcode          &    0xF;
-
-  return val;
-};
-
 pdns.unpackQname = function (ui8) {
   var total = 0;
   var i;
@@ -230,3 +213,4 @@ pdns.unpack = function (ab) {
   header.total = total;
   return header;
 };
+pdns.unpackRdata = require('./dns.rdata.parse.js').DNS_RDATA_PARSE;