From d82f8ac8b37114fe180a0e02f56289ae0f3141a2 Mon Sep 17 00:00:00 2001
From: Deon George <deon@dege.au>
Date: Wed, 4 Oct 2023 15:50:24 +1100
Subject: [PATCH] Catch bad DNS queries and reduce exception logging

---
 app/Classes/Protocol/DNS.php       | 9 ++++++++-
 app/Classes/Protocol/DNS/Query.php | 7 +++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/app/Classes/Protocol/DNS.php b/app/Classes/Protocol/DNS.php
index e6d9fbd..bbc7b79 100644
--- a/app/Classes/Protocol/DNS.php
+++ b/app/Classes/Protocol/DNS.php
@@ -104,7 +104,14 @@ final class DNS extends BaseProtocol
 	{
 		Log::debug(sprintf('%s:+ DNS Query',self::LOGKEY));
 
-		$this->query = new BaseProtocol\DNS\Query($this->client->read(0,512));
+		try {
+			$this->query = new BaseProtocol\DNS\Query($this->client->read(0,512));
+
+		} catch (\Exception $e) {
+			Log::error(sprintf('%s:! Ignoring bad DNS query (%s)',self::LOGKEY,$e->getMessage()));
+
+			return FALSE;
+		}
 
 		Log::info(sprintf('%s:= DNS Query from [%s] for [%s]',self::LOGKEY,$this->client->address_remote,$this->query->domain));
 
diff --git a/app/Classes/Protocol/DNS/Query.php b/app/Classes/Protocol/DNS/Query.php
index 9a77ae8..02120d9 100644
--- a/app/Classes/Protocol/DNS/Query.php
+++ b/app/Classes/Protocol/DNS/Query.php
@@ -61,7 +61,7 @@ final class Query
 		} 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;
+			throw $e;
 		}
 
 		$rx_ptr += 4;
@@ -82,9 +82,8 @@ final class Query
 			$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,$rx_ptr))]);
-		}
+		if (strlen($this->buf) !== $rx_ptr)
+			throw new \Exception(sprintf('! DNS Buffer still has [%d]: %s',strlen($this->buf)-$rx_ptr,hex_dump(substr($this->buf,$rx_ptr))));
 	}
 
 	public function __get($key)