Add PTR support

README.md

@@ -3,75 +3,97 @@
 dns-axfr is a node.js module which extends dns core module to add support for AXFR type queries. It can be useful for pentesting tasks, automating recursive zone transfers, etc...
 
 The following type of records are supported:
-* A
-* CNAME
-* SOA
-* MX
-* NS
-* TXT
-* AAAA
-* SPF
-* SRV
+
+- A
+- CNAME
+- SOA
+- MX
+- NS
+- TXT
+- AAAA
+- SPF
+- SRV
+- PTR
 
 ## Usage
 
-In otder to perform an AXFR query use `resolveAxfr()`
+In order to perform an AXFR query use `resolveAxfr()`
 
 ### resolveAxfr(server, zone, callback)
+
+```javascript
+var dns = require("dns-axfr");
+var util = require("util");
+
+dns.resolveAxfr("dns01.acme.com", "acme.com", function (err, addr) {
+  if (err) {
+    console.error("Error ocurred: " + addr + " (" + err + ")");
+    return;
+  }
+
+  console.log(util.inspect(addr));
+});
+```
+
+Reverse lookup example
+
 ```javascript
-var dns = require('dns-axfr');
-var util = require('util');
+var dns = require("dns-axfr");
+var util = require("util");
 
-dns.resolveAxfr('dns01.acme.com', 'acme.com', function(err, addr) {
-    if (err) {
-        console.error('Error ocurred: ' + addr + ' (' + err + ')');
-        return;
-    }
+dns.resolveAxfr("dns01.acme.com", "0.0.10.in-addr.arpa", function (err, addr) {
+  if (err) {
+    console.error("Error ocurred: " + addr + " (" + err + ")");
+    return;
+  }
 
-    console.log(util.inspect(addr));
+  console.log(util.inspect(addr));
 });
 ```
 
 If you need to setup a timeout for the request use `resolveAxfrTimeout()` and set the desired timeout in milliseconds.
 
 ### resolveAxfrTimeout(timeout)
+
 ```javascript
-var dns = require('dns-axfr');
-var util = require('util');
+var dns = require("dns-axfr");
+var util = require("util");
 
 dns.resolveAxfrTimeout(1000);
 
-dns.resolveAxfr('dns01.acme.com', 'acme.com', function(err, addr) {
-    if (err) {
-        console.error('Error ocurred: ' + addr + ' (' + err + ')');
-        return;
-    }
+dns.resolveAxfr("dns01.acme.com", "acme.com", function (err, addr) {
+  if (err) {
+    console.error("Error ocurred: " + addr + " (" + err + ")");
+    return;
+  }
 
-    console.log(util.inspect(addr));
+  console.log(util.inspect(addr));
 });
 ```
 
-
-
 As this module extends the core dns module, you can access the original module without "requiring" it again:
+
 ```javascript
-var dns = require('dns-axfr');
-var util = require('util');
+var dns = require("dns-axfr");
+var util = require("util");
 
 /* Extended function */
-dns.resolveAxfr('dns01.acme.com', 'acme.com', function(err, addr) {
-    if (err) throw err;
-    console.log(util.inspect(addr));
+dns.resolveAxfr("dns01.acme.com", "acme.com", function (err, addr) {
+  if (err) throw err;
+  console.log(util.inspect(addr));
 });
 
 /* Original dns module function */
-dns.resolve4('www.google.com', function (err, addresses) {
+dns.resolve4("www.google.com", function (err, addresses) {
   if (err) throw err;
   console.log(util.inspect(addresses));
 });
 ```
 
 ## Sample results
+
+Forward lookup example
+
 ```javascript
 {
     questions: [
@@ -150,3 +172,42 @@ dns.resolve4('www.google.com', function (err, addresses) {
     ]
 }
 ```
+
+Reverse lookup example
+
+```javascript
+{
+    questions: [
+        {
+            name: '0.0.10.in-addr.arpa.',
+            type: 'AXFR'
+        }
+    ],
+    answers: [
+        {
+            name: '0.0.10.in-addr.arpa.',
+            type: 'SOA',
+            ttl: 21600,
+            dns: 'ns1.acme.es.',
+            mail: 'root.ns1.acme.es.',
+            serial: 2015012401,
+            refresInterval: 14400,
+            retryInterval: 7200,
+            expireLimit: 2592000,
+            minTTL: 28800
+        },
+        {
+            name: '1.0.0.10.in-addr.arpa.',
+            type: 'PTR',
+            ttl: 21600,
+            dns: 'gateway.acme.es.'
+        },
+        {
+            name: '2.0.0.10.in-addr.arpa.',
+            type: 'PTR',
+            ttl: 21600,
+            dns: 'ns1.acme.es.'
+        }
+    ]
+}
+```

index.js

@@ -163,6 +163,12 @@ function parseResponse(response, result) {
                 entry.mx = decompressLabel(response, (offset + 12)).name;
                 break;
 
+            /* PTR Record */
+            case 0x0c:
+                entry.type = 'PTR';
+                entry.dns = decompressLabel(response, (offset + 10)).name;
+                break;
+
             /* TXT Record */
             case 0x10:
                 entry.type = 'TXT';