From bedebc75e1f88d02e737203b09041c39094d5777 Mon Sep 17 00:00:00 2001
From: Irine Sistiana <49315432+IrineSistiana@users.noreply.github.com>
Date: Thu, 21 Sep 2023 11:04:03 +0800
Subject: [PATCH 4/6] pool: fixed PackTCPBuffer always re-allocate

---
 pkg/pool/msg_buf.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkg/pool/msg_buf.go b/pkg/pool/msg_buf.go
index f132cc2..11faf7d 100644
--- a/pkg/pool/msg_buf.go
+++ b/pkg/pool/msg_buf.go
@@ -60,13 +60,14 @@ func PackTCPBuffer(m *dns.Msg) (buf *[]byte, err error) {
 		return nil, fmt.Errorf("dns payload size %d is too large", l)
 	}
 
-	if &((*b)[0]) != &wire[0] { // reallocated
+	if &((*b)[2]) != &wire[0] { // reallocated
 		ReleaseBuf(b)
 		b = GetBuf(l + 2)
 		binary.BigEndian.PutUint16((*b)[:2], uint16(l))
 		copy((*b)[2:], wire)
 		return b, nil
 	}
+	binary.BigEndian.PutUint16((*b)[:2], uint16(l))
 	*b = (*b)[:2+l]
 	return b, nil
 }
-- 
2.34.8