Fix A & AAAA, add CNAME Tests

dns.packer.type.a.js

@@ -9,7 +9,8 @@ exports.DNS_PACKER_TYPE_A = function (ab, dv, total, record) {
   }
 
   // RDLENGTH
-  dv.setUint16(total, 4, false);
+  var IP_LEN = 4;
+  dv.setUint16(total, IP_LEN, false);
   total += 2;
 
   // RDATA

dns.packer.type.aaaa.js

@@ -25,7 +25,8 @@ exports.DNS_PACKER_TYPE_AAAA = function (ab, dv, total, record) {
   });
 
   // RDLENGTH
-  dv.setUint16(total, 16, false);
+  var IP_LEN = 16;
+  dv.setUint16(total, IP_LEN, false);
   total += 2;
 
   // RDATA

dns.packer.type.cname.js

@@ -0,0 +1,35 @@
+(function (exports) {
+'use strict';
+
+// A 'CNAME' record is a 32-bit value representing the IP address
+
+exports.DNS_PACKER_TYPE_CNAME = function (ab, dv, total, record) {
+  if (!record.data) {
+    throw new Error("no data for CNAME record");
+  }
+
+  var cnameLen = 0;
+  var rdLenIndex = total;
+  total += 2;
+
+  // RDATA
+  // i.e. 127.0.0.1 => 0x7F, 0x00, 0x00, 0x01
+  record.data.split('.').forEach(function (label) {
+    cnameLen += 1 + label.length;
+    
+    dv.setUint8(total, label.length, false);
+    total += 1;
+
+    label.split('').forEach(function (ch) {
+      dv.setUint8(total, ch.charCodeAt(0), false);
+      total += 1;
+    });
+  });
+
+  // RDLENGTH
+  dv.setUint16(rdLenIndex, record.data.length + 1, false);
+  
+  return total;
+};
+
+}('undefined' !== typeof window ? window : exports));

test/packer.type.a.js

@@ -1,7 +1,7 @@
 'use strict';
 
 var packer = require('../dns.packer.type.a.js').DNS_PACKER_TYPE_A;
-var ab = new ArrayBuffer(4);
+var ab = new ArrayBuffer(6); // 16-bit RDLENGTH + 32-bit address
 var dv = new DataView(ab);
 var total;
 
@@ -16,11 +16,12 @@ dv.setUint32(0x0, 0xDDDDDDDD, false);
 ].forEach(function (ipv4) {
   total = 0;
   total = packer(ab, dv, total, { address: ipv4 });
-  if (0x04 !== total) {
+  if (0x06 !== total) {
     console.error('unexpected total ' + total);
     process.exit(1);
   }
-  if (ipv4 !== new Uint8Array(ab).join('.')) {
+  // 0.4 is just a hacky way to account for the RDLENGTH
+  if ('0.4.' + ipv4 !== new Uint8Array(ab).join('.')) {
     console.error("expected: ", ipv4);
     console.error("actual: ", new Uint8Array(ab).join('.'));
     process.exit(1);

test/packer.type.aaaa.js

@@ -1,7 +1,7 @@
 'use strict';
 
 var packer = require('../dns.packer.type.aaaa.js').DNS_PACKER_TYPE_AAAA;
-var ab = new ArrayBuffer(20);
+var ab = new ArrayBuffer(22);
 var dv = new DataView(ab);
 var total = 0;
 
@@ -16,18 +16,19 @@ dv.setUint16(0xC, 0xDDDD, false);
 dv.setUint16(0xE, 0xDDDD, false);
 dv.setUint16(0x10, 0xDDDD, false);
 dv.setUint16(0x12, 0xDDDD, false);
+dv.setUint16(0x14, 0xDDDD, false);
 
 [ [ '::1'
-  , [ 0xDD, 0xDD, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0xDD, 0xDD ].join(' ') ]
+  , [ 0xDD, 0xDD, 0x00, 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0xDD, 0xDD ].join(' ') ]
 , [ 'fe80::1'
-  , [ 0xDD, 0xDD, 0xFE, 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0xDD, 0xDD ].join(' ') ]
+  , [ 0xDD, 0xDD, 0x00, 0x10, 0xFE, 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0xDD, 0xDD ].join(' ') ]
 , [ 'fd41:50ca:2169:f4e:5020:f756:ca4e:c3b5'
-  , [ 0xDD, 0xDD, 0xFD, 0x41, 0x50, 0xCA, 0x21, 0x69, 0x0F, 0x4E
+  , [ 0xDD, 0xDD, 0x00, 0x10, 0xFD, 0x41, 0x50, 0xCA, 0x21, 0x69, 0x0F, 0x4E
     , 0x50, 0x20, 0xF7, 0x56, 0xCA, 0x4E, 0xC3, 0xB5, 0xDD, 0xDD ].join(' ') ]
 ].forEach(function (ipv6) {
-  total = 2; // leave leading 0x00
+  total = 2; // leave leading 0xDD
   total = packer(ab, dv, total, { address: ipv6[0] });
-  if (0x12 !== total) {
+  if (0x14 !== total) {
     console.error('unexpected total ' + total);
     process.exit(1);
   }

test/packer.type.cname.js

@@ -0,0 +1,21 @@
+'use strict';
+
+var packer = require('../dns.packer.type.cname.js').DNS_PACKER_TYPE_CNAME;
+var ab = new ArrayBuffer(255); // max len per label is 63, max label sequence is 254 + null terminator
+var dv = new DataView(ab);
+var total = 0;
+
+[ [ 'www.example.com'
+  , [ 0x00, 0x10, 0x03, 119, 119, 119, 0x07, 101, 120, 97, 109, 112, 108, 101, 0x03, 99, 111, 109 ].join(' ') ]
+].forEach(function (cname) {
+  total = packer(ab, dv, total, { data: cname[0] });
+  ab = ab.slice(0, total);
+  // TODO: Check that total increments appropriately
+  if (cname[1] !== new Uint8Array(ab).join(' ')) {
+    console.error("expected: ", cname[1]);
+    console.error("actual: ", new Uint8Array(ab).join(' '));
+    process.exit(1);
+  }
+});
+
+console.log('PASS');