From d0663277dc519f93082358d844dfdddf3b7713c6 Mon Sep 17 00:00:00 2001
From: rookisbusy <rookisbusy@gmail.com>
Date: Thu, 30 Mar 2023 14:17:25 +0800
Subject: [PATCH] safe dns buff size

---
 listener/sing_tun/dns.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/listener/sing_tun/dns.go b/listener/sing_tun/dns.go
index 21dee43c..f2daaf0c 100644
--- a/listener/sing_tun/dns.go
+++ b/listener/sing_tun/dns.go
@@ -110,7 +110,10 @@ func (h *ListenerHandler) NewPacketConnection(ctx context.Context, conn network.
 			conn2 = nil
 		}()
 		for {
-			buff := buf.NewPacket()
+			// safe size which is 1232 from https://dnsflagday.net/2020/.
+			// so 2048 is enough
+			buff := buf.NewSize(2 * 1024)
+			_ = conn.SetReadDeadline(time.Now().Add(DefaultDnsReadTimeout))
 			dest, err := conn.ReadPacket(buff)
 			if err != nil {
 				buff.Release()