WIP unpack question and resource records

bin/debug.js

@@ -5,7 +5,7 @@ var input = process.argv[2];
 var fs = require('fs');
 var nb = fs.readFileSync(input, null);
 
-var ab = nb.buffer.slice(nb.byteOffset, nb.byteOffset + nb.byteLength)
+var ab = nb.buffer.slice(nb.byteOffset, nb.byteOffset + nb.byteLength);
 var dv = new DataView(ab);
 
 //
@@ -19,36 +19,130 @@ console.log('');
 
 console.log('id (int)', dv.getUint16(0));
 
-var i = dv.getUint16(2, false);
-console.log('header 0x', i.toString(16));
+var flags = dv.getUint16(2, false);
+console.log('header 0x', flags.toString(16));
 var flagsstr = ''
-	+ 'qr ' + ((i & 0x8000) >> 15) + ', '
-  + 'opcode ' + ((i & 0x7800) >> 11) + ', '
-  + 'aa ' + ((i &  0x400) >> 10) + ', '
-  + 'tc ' + ((i &  0x200) >>  9) + ', '
-  + 'rd ' + ((i &  0x100) >>  8) + ', '
-  + 'ra ' + ((i &   0x80) >>  7) + ', '
-  + 'res1 ' + ((i &   0x40) >>  6) + ', '
-  + 'res2 ' + ((i &   0x20) >>  5) + ', '
-  + 'res3 ' + ((i &   0x10) >>  4) + ', '
-  + 'rcode ' + ((i &    0xF));
+	+ 'qr ' + ((flags & 0x8000) >> 15) + ', '
+  + 'opcode ' + ((flags & 0x7800) >> 11) + ', '
+  + 'aa ' + ((flags &  0x400) >> 10) + ', '
+  + 'tc ' + ((flags &  0x200) >>  9) + ', '
+  + 'rd ' + ((flags &  0x100) >>  8) + ', '
+  + 'ra ' + ((flags &   0x80) >>  7) + ', '
+  + 'res1 ' + ((flags &   0x40) >>  6) + ', '
+  + 'res2 ' + ((flags &   0x20) >>  5) + ', '
+  + 'res3 ' + ((flags &   0x10) >>  4) + ', '
+  + 'rcode ' + ((flags &    0xF));
 console.log('(flags: ' + flagsstr);
 
 var qdcount = dv.getUint16(4, false);  // query count
 var ancount = dv.getUint16(6, false);  // answer count
 var nscount = dv.getUint16(8, false);  // authority count
 var arcount = dv.getUint16(10, false); // additional count
+var count;
 
 console.log('qdcount', qdcount);
 console.log('ancount', ancount);
 console.log('nscount', nscount);
 console.log('arcount', arcount);
 
+var total = 12;
+
+function unpackQuestion(dv, total, len) {
+  var qnames = [];
+  var labelLen;
+  while (true) {
+    if (total >= len) {
+      break;
+    }
+    labelLen = dv.getUint8(total, false); // additional count
+    total += 1;
+    if (!labelLen) {
+      break;
+    }
+    if (192 === labelLen) {
+      console.log('ERROR: Compression pointer found');
+      console.log(dv.getUint8(total, false));
+      console.log(dv.getUint8(dv.getUint8(total + 0, false), false));
+      console.log(dv.getUint8(dv.getUint8(total + 1, false), false));
+      console.log(dv.getUint8(dv.getUint8(total + 2, false), false));
+      break;
+    }
+    var i;
+    var label = '';
+    console.log('label len', labelLen);
+    for (i = 0; i < labelLen; i += 1) {
+      label += String.fromCharCode(dv.getUint8(total + i, false));
+    }
+    total += label.length;
+    console.log('label:', label);
+    qnames.push(label);
+  }
+  console.log('QNAME:', qnames.join('.'));
+  console.log('QTYPE:', dv.getUint16(total), false);
+  total += 2;
+  console.log('QCLASS:', dv.getUint16(total), false);
+  total += 2;
+
+  return {
+    total: total
+  , qname: qnames.join('.')
+  };
+}
+
+var q = { total: total };
+function mapChar(ch) { return String.fromCharCode(ch) + '(' + ch + ')'; }
+
 console.log('');
 console.log('//////////////////');
 console.log('//   QUESTION   //');
 console.log('//////////////////');
 console.log('');
+for (count = 0; count < qdcount; count += 1) {
+  console.log('Question', count + 1, 'of', qdcount);
+  q = unpackQuestion(dv, q.total, ab.byteLength);
+  console.log('');
+}
+
+console.log('');
+console.log('//////////////////');
+console.log('//    ANSWER    //');
+console.log('//////////////////');
+console.log('');
+for (count = 0; count < ancount; count += 1) {
+  console.log('Answer', count + 1, 'of', ancount);
+  q = unpackQuestion(dv, q.total, ab.byteLength);
+  console.log('');
+}
+
+
+console.log('');
+console.log('//////////////////');
+console.log('//   AUTHORITY  //');
+console.log('//////////////////');
+console.log('');
+for (count = 0; count < nscount; count += 1) {
+  console.log('Authority', count + 1, 'of', nscount);
+  q = unpackQuestion(dv, q.total, ab.byteLength);
+  console.log('ttl:', dv.getUint32(q.total, false));
+  q.total += 4;
+  q.rdlength = dv.getUint16(q.total, false);
+  console.log('rdlen:', q.rdlength);
+  q.total += 2;
+  console.log('rrdata:');
+  console.log([].slice.call(new Uint8Array(ab), q.total, q.total + q.rdlength).map(mapChar));
+  q.total += q.rdlength;
+}
+
+console.log('');
+console.log('//////////////////');
+console.log('//  ADDITIONAL  //');
+console.log('//////////////////');
+console.log('');
+for (count = 0; count < arcount; count += 1) {
+  console.log('Additional', count + 1, 'of', arcount);
+  q = unpackQuestion(dv, q.total, ab.byteLength);
+  console.log('');
+}
 
 
 }());