From 62f0c1a909422aa6d57163b9370a093c6361ad95 Mon Sep 17 00:00:00 2001
From: Deon George <deon@dege.au>
Date: Tue, 3 Oct 2023 23:15:21 +1100
Subject: [PATCH] DNS server now responds to SRV and TXT records

---
 app/Classes/Protocol/DNS.php | 61 +++++++++++++++++++++++++++++++++---
 1 file changed, 57 insertions(+), 4 deletions(-)

diff --git a/app/Classes/Protocol/DNS.php b/app/Classes/Protocol/DNS.php
index aa836ab..e6d9fbd 100644
--- a/app/Classes/Protocol/DNS.php
+++ b/app/Classes/Protocol/DNS.php
@@ -8,7 +8,7 @@ use Illuminate\Support\Str;
 use App\Classes\Protocol as BaseProtocol;
 use App\Classes\Sock\SocketClient;
 use App\Http\Controllers\DomainController;
-use App\Models\{Address,Domain};
+use App\Models\{Address,Domain,Mailer};
 
 /**
  * Respond to DNS queries and provide addresses to FTN nodes.
@@ -164,9 +164,28 @@ final class DNS extends BaseProtocol
 			case self::DNS_TYPE_CNAME:
 			case self::DNS_TYPE_A:
 			case self::DNS_TYPE_AAAA:
+			case self::DNS_TYPE_SRV:
+			case self::DNS_TYPE_TXT:
 				Log::info(sprintf('%s:= Looking for record [%s] for [%s]',self::LOGKEY,$this->query->type,$this->query->domain));
 
 				$labels = clone($this->query->labels);
+				$mailer = '';
+
+				// If this is a SRV record query
+				if ($this->query->type === self::DNS_TYPE_SRV) {
+					switch ($labels->first()) {
+						case '_binkp':
+							if ($labels->skip(1)->first() !== '_tcp')
+								return $this->reply(self::DNS_NAMEERR);
+
+							$labels->shift(2);
+							$mailer = Mailer::where('name','BINKP')->singleOrFail();
+							break;
+
+						default:
+							return $this->reply(self::DNS_NAMEERR);
+					}
+				}
 
 				// First check that it is a query we can answer
 				// First label should be p.. or f..
@@ -207,9 +226,33 @@ final class DNS extends BaseProtocol
 
 				Log::info(sprintf('%s:= Returning [%s] for DNS query [%s]',self::LOGKEY,$ao->system->address,$ao->ftn));
 
-				return $this->reply(
-					self::DNS_NOERROR,
-					[serialize($this->domain_split($ao->system->address)) => self::DNS_TYPE_CNAME]);
+				switch ($this->query->type) {
+					case self::DNS_TYPE_SRV:
+						if ($xx=$ao->system->mailers->where('id',$mailer->id)->pop()) {
+							return $this->reply(
+								self::DNS_NOERROR,
+								[serialize([
+									0,
+									0,
+									$xx->pivot->port,
+									$this->domain_split($ao->system->address),
+								]) => self::DNS_TYPE_SRV]);
+
+						} else {
+							return $this->nameerr();
+						}
+
+					case self::DNS_TYPE_TXT:
+						return $this->reply(
+							self::DNS_NOERROR,
+							[serialize($ao->system->name) => self::DNS_TYPE_TXT]);
+
+					default:
+						return $this->reply(
+							self::DNS_NOERROR,
+							[serialize($this->domain_split($ao->system->address)) => self::DNS_TYPE_CNAME]);
+
+				}
 
 			// Other attributes return NOTIMPL
 			default:
@@ -378,6 +421,16 @@ final class DNS extends BaseProtocol
 				$a .= pack('NNNNN',$ars[2],$ars[3],$ars[4],$ars[5],$ars[6]);
 
 				break;
+
+			case self::DNS_TYPE_SRV:
+				$a .= pack('nnn',$ars[0],$ars[1],$ars[2]);
+				$a .= $ars[3];
+
+				break;
+
+			case self::DNS_TYPE_TXT:
+				$a .= pack('C',strlen($ars)).$ars;
+				break;
 		}
 
 		$reply .= pack('n',strlen($a)).$a;