From b7c1c97cf7e3748b2ff87774ba70e573b8cf5b9c Mon Sep 17 00:00:00 2001
From: Deon George <deon@dege.au>
Date: Wed, 20 Sep 2023 22:26:35 +1000
Subject: [PATCH] Catch DNS Query that fail unpack()

---
 app/Classes/Protocol/DNS/Query.php | 16 +++++++++++++---
 app/Classes/Sock/SocketClient.php  |  2 +-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/app/Classes/Protocol/DNS/Query.php b/app/Classes/Protocol/DNS/Query.php
index f9003fc..ac9d18b 100644
--- a/app/Classes/Protocol/DNS/Query.php
+++ b/app/Classes/Protocol/DNS/Query.php
@@ -32,7 +32,8 @@ final class Query
 		'arcount'	=> [0x05,'n',1],		// Resource Records in the addition records section
 	];
 
-	public function __construct(string $buf) {
+	public function __construct(string $buf)
+	{
 		$this->buf = $buf;
 		$rx_ptr = 0;
 
@@ -54,7 +55,15 @@ final class Query
 		}
 
 		// Get the query type/class
-		$result = unpack('ntype/nclass',substr($this->buf,$rx_ptr,4));
+		try {
+			$result = unpack('ntype/nclass',substr($this->buf,$rx_ptr,4));
+
+		} catch (\Exception $e) {
+			Log::error(sprintf('%s:! Unpack failed: Buffer: [%s] (%d), RXPTR [%d]',self::LOGKEY,hex_dump($this->buf),strlen($this->buf),$rx_ptr));
+
+			return;
+		}
+
 		$rx_ptr += 4;
 		$this->type = $result['type'];
 		$this->class = $result['class'];
@@ -96,7 +105,8 @@ final class Query
 		}
 	}
 
-	public static function header_len() {
+	public static function header_len()
+	{
 		return collect(self::header)->sum(function($item) { return $item[2]*2; });
 	}
 
diff --git a/app/Classes/Sock/SocketClient.php b/app/Classes/Sock/SocketClient.php
index 11996f0..8a8626d 100644
--- a/app/Classes/Sock/SocketClient.php
+++ b/app/Classes/Sock/SocketClient.php
@@ -320,7 +320,7 @@ final class SocketClient {
 			}
 
 		} catch (\Exception $e) {
-			Log::error(sprintf('%s: - socket_recv Exception [%s]',self::LOGKEY,$e->getMessage()));
+			Log::error(sprintf('%s:! socket_recv Exception [%s]',self::LOGKEY,$e->getMessage()));
 
 			throw new SocketException($x=socket_last_error($this->connection),socket_strerror($x));
 		}