From 2388b46c748f239359e5bf1695f91f83415b1baf Mon Sep 17 00:00:00 2001
From: Daplie <westley.barragan@daplie.com>
Date: Wed, 15 Mar 2017 20:24:03 -0600
Subject: [PATCH] sort of round about way to get the email property of SOA
 RDATA. Let me know if theirs a better way

---
 parser/type.soa.js | 39 ++++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/parser/type.soa.js b/parser/type.soa.js
index 175047b..1a3f834 100644
--- a/parser/type.soa.js
+++ b/parser/type.soa.js
@@ -18,41 +18,38 @@ exports.DNS_PARSER_TYPE_SOA = function (ab, packet, record) {
 
   var rdataAb = ab.slice(record.rdstart, record.rdstart + record.rdlength);
   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 offset = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).byteLength;
   var labels = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).labels;
-  console.log("offset is: " + offset); 
-  console.log("cpcount is: " + cpcount);
-  console.log("the labels are : " + labels);
-  console.log("rdstart is: " + record.rdstart);
-  for(var i = 0; i < dv.byteLength;i++){
-
-    console.log(parseInt(dv.getUint8(i), 10).toString(16));
-  }
 
   // Primary NS
   record.name_server = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
-  // var offset = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).byteLength;
-  // Admin MB. This email address is always preceeded by 6 Bytes of the name_server data and email_addr length.
-  // ie: ns1.example.com, where ns1 is 3 bytes, example.com represented by 2 bytes (c0 0c - compression pointer) and then
-  // 1 more byte representing the email_addr length.
-  // TODO: email_addr probably shouldn't be parsed this way. The email_addr length byte is probably there to parse this in a more robust way
-  // we just have to figure that out  
-
-
+  
+  // if there exists compression pointers in the rdata
   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.
 
-    console.log("name server length is: " + record.name_server.length);
-    var email_len = parseInt(dv.getUint8(0), 10) + ;dv.getUint16(0)
-    console.log("email_start is: " + email_len);
-    record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart , { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
+    var start = 2; // start or email_addr. take into account compression pointer and address length
+    for(var i = 0; i < labels.length; i++){
 
-  }
+      // 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){
+        record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + start ,{ byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
+      }
+    }    
+  } // if there are no compression pointers, we can get the email address directly from the offset
   else {
 
     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