From 3691741440b051fa20f174cfc471d038f2b3c06d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=A3=8E=E6=89=87=E6=BB=91=E7=BF=94=E7=BF=BC?=
 <Fangliding.fshxy@outlook.com>
Date: Thu, 16 Apr 2026 00:57:51 +0800
Subject: [PATCH] Chore: Use buf.New() instead of buf.NewWithSize() (#5946)

https://github.com/XTLS/Xray-core/pull/5941#issuecomment-4252905907

https://github.com/XTLS/Xray-core/pull/5946#issuecomment-4253919073
---
 proxy/hysteria/client.go                  | 14 ++++++++++----
 proxy/tun/udp_fullcone.go                 |  6 ++++--
 proxy/wireguard/tun.go                    |  7 +++++--
 transport/internet/finalmask/finalmask.go | 11 +++++------
 4 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/proxy/hysteria/client.go b/proxy/hysteria/client.go
index 7c2bc58d..614a7ff9 100644
--- a/proxy/hysteria/client.go
+++ b/proxy/hysteria/client.go
@@ -244,8 +244,11 @@ type UDPReader struct {
 
 func (r *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	if r.firstMsg != nil {
-		buffer := buf.NewWithSize(int32(len(r.firstMsg.Data)))
-		buffer.Write(r.firstMsg.Data)
+		buffer := buf.New()
+		_, err := buffer.Write(r.firstMsg.Data)
+		if err != nil {
+			return nil, err
+		}
 		buffer.UDP = r.firstDest
 
 		r.firstMsg = nil
@@ -275,8 +278,11 @@ func (r *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 			continue
 		}
 
-		buffer := buf.NewWithSize(int32(len(dfMsg.Data)))
-		buffer.Write(dfMsg.Data)
+		buffer := buf.New()
+		if _, err := buffer.Write(dfMsg.Data); err != nil {
+			return nil, err
+		}
+
 		buffer.UDP = &dest
 
 		return buf.MultiBuffer{buffer}, nil
diff --git a/proxy/tun/udp_fullcone.go b/proxy/tun/udp_fullcone.go
index fdec7bf6..ab59e97f 100644
--- a/proxy/tun/udp_fullcone.go
+++ b/proxy/tun/udp_fullcone.go
@@ -103,8 +103,10 @@ func (c *udpConn) ReadMultiBuffer() (buf.MultiBuffer, error) {
 		return nil, io.EOF
 	}
 
-	b := buf.NewWithSize(int32(len(e.data)))
-	b.Write(e.data)
+	b := buf.New()
+	if _, err := b.Write(e.data); err != nil {
+		return nil, err
+	}
 	b.UDP = e.dest
 
 	return buf.MultiBuffer{b}, nil
diff --git a/proxy/wireguard/tun.go b/proxy/wireguard/tun.go
index 6decfa70..4168e175 100644
--- a/proxy/wireguard/tun.go
+++ b/proxy/wireguard/tun.go
@@ -350,8 +350,11 @@ func (c *udpConn) ReadMultiBuffer() (buf.MultiBuffer, error) {
 		return nil, io.EOF
 	}
 
-	b := buf.NewWithSize(int32(len(q.p)))
-	b.Write(q.p)
+	b := buf.New()
+	if _, err := b.Write(q.p); err != nil {
+		return nil, err
+	}
+
 	b.UDP = q.dest
 
 	return buf.MultiBuffer{b}, nil
diff --git a/transport/internet/finalmask/finalmask.go b/transport/internet/finalmask/finalmask.go
index e7bf0080..2fca1215 100644
--- a/transport/internet/finalmask/finalmask.go
+++ b/transport/internet/finalmask/finalmask.go
@@ -5,7 +5,7 @@ import (
 	"net"
 	"sync"
 
-	xbuf "github.com/xtls/xray-core/common/buf"
+	"github.com/xtls/xray-core/common/bytespool"
 	"github.com/xtls/xray-core/common/errors"
 )
 
@@ -150,11 +150,10 @@ type headerReadAddrAware interface {
 func (c *headerManagerConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 	buf := p
 	if len(buf) < UDPSize {
-		b := xbuf.NewWithSize(UDPSize)
-		defer b.Release()
-		b.Resize(0, UDPSize)
-
-		buf = b.Bytes()
+		b := bytespool.Alloc(UDPSize)
+		b = b[:UDPSize]
+		defer bytespool.Free(b)
+		buf = b
 	}
 
 	n, addr, err = c.PacketConn.ReadFrom(buf)