Enhancements to DNS server and notes for usage with bind

app/Classes/Protocol/DNS/Query.php

@@ -3,15 +3,23 @@
 namespace App\Classes\Protocol\DNS;
 
 use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\Log;
 
 final class Query
 {
+	private const LOGKEY = 'PDQ';
+
 	private string $buf;
 	private int $class;
-	private string $domain;
+	private string $dns;
 	private int $id;
 	private int $type;
 
+	private int $arcount;
+	private int $qdcount;
+
+	private RR $additional;
+
 	private Collection $labels;
 
 	// https://github.com/guyinatuxedo/dns-fuzzer/blob/master/dns.md
@@ -34,6 +42,8 @@ final class Query
 
 		$this->id = $header['id'];
 		$this->qdcount = $header['qdcount'];
+		$this->arcount = $header['arcount'];
+		$this->header = $header['header'];
 
 		// Get the domain elements
 		$this->labels = collect();
@@ -49,19 +59,40 @@ final class Query
 		$this->type = $result['type'];
 		$this->class = $result['class'];
 
-		$this->domain = substr($this->buf,$x=$this->header_len(),$rx_ptr-$x);
+		$this->dns = substr($this->buf,$this->header_len(),$rx_ptr-$this->header_len());
+
+		// Do we have additional records
+		if ($this->arcount) {
+			// Additional records, EDNS: https://datatracker.ietf.org/doc/html/rfc6891
+			if (($haystack = strstr(substr($this->buf,$rx_ptr+1+10),"\x00",true)) !== FALSE) {
+				Log::error(sprintf('%s:! DNS additional record format error?',self::LOGKEY));
+				// @todo catch this
+			}
+
+			$this->additional = new RR(substr($this->buf,$rx_ptr,(strlen($haystack) === 0) ? NULL : strlen($haystack)));
+			$rx_ptr += $this->additional->length;
+		}
+
+		if (strlen($this->buf) !== $rx_ptr) {
+			dd(['query remaining'=>strlen($this->buf)-$rx_ptr,'hex'=>hex_dump(substr($this->buf,$rx_ptr))]);
+		}
 	}
 
 	public function __get($key)
 	{
 		switch ($key) {
 			case 'class':
-			case 'domain':
+			case 'dns':
 			case 'id':
 			case 'labels':
 			case 'qdcount':
+			case 'arcount':
+			case 'header':
 			case 'type':
 				return $this->{$key};
+
+			case 'domain':
+				return $this->labels->join('.');
 		}
 	}
 

app/Classes/Protocol/DNS/RR.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace App\Classes\Protocol\DNS;
+
+use Illuminate\Support\Arr;
+use Illuminate\Support\Collection;
+
+use App\Classes\Protocol\DNS;
+
+final class RR
+{
+	private const LOGKEY = 'PDR';
+
+	public Collection $labels;
+	public int $type;
+	public int $class;
+	private string $buf;
+
+	public function __construct(string $buf)
+	{
+		$this->buf = $buf;
+		$this->labels = collect();
+
+		$i = 0;
+
+		$domain = strstr($buf,"\x00",TRUE);
+		$i += strlen($domain)+1;
+
+		$this->type = Arr::get(unpack('n',substr($buf,$i,2)),1);
+		$this->class = Arr::get(unpack('n',substr($buf,$i+2,2)),1);
+		$i += 4;
+
+		switch ($this->type) {
+			case DNS::DNS_TYPE_CNAME:
+			case DNS::DNS_TYPE_NS:
+			case DNS::DNS_TYPE_DS:
+			case DNS::DNS_TYPE_SOA:
+				$i = 0;
+
+				while (($len=ord(substr($domain,$i++,1))) !== 0x00) {
+					$this->labels->push(substr($buf,$i,$len));
+					$i += $len;
+				}
+
+				break;
+
+			case DNS::DNS_TYPE_OPT:
+				// Domain is 0x00
+				$this->ttl = Arr::get(unpack('N',substr($buf,$i,4)),1);
+				$this->rddata_len = Arr::get(unpack('n',substr($buf,$i+4,2)),1);
+				$this->rddata = substr($buf,$i+6,$this->rddata_len);
+
+				break;
+
+			default:
+				dd(['unknown type:'.$this->type,'buf'=>$this->buf]);
+		}
+	}
+
+	public function __get(string $key): mixed
+	{
+		switch ($key) {
+			case 'length':
+				return strlen($this->buf);
+
+			default:
+				throw new \Exception(sprintf('%s:Unknown key [%s]',self::LOGKEY,$key));
+		}
+	}
+
+	public function __tostring(): string
+	{
+		return $this->buf;
+	}
+}