From 96511d861335f5c51d617bb06d3c545c4ecf4faf Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Wed, 10 May 2023 22:35:50 +0800
Subject: [PATCH] chore: sing inbound support WaitReadPacket

---
 listener/shadowsocks/udp.go         |  2 +-
 listener/sing/sing.go               | 21 ++++++++++++++++---
 listener/sing_shadowsocks/server.go | 31 +++++++++++++++++++++--------
 listener/sing_tun/dns.go            | 26 +++++++++++++++++++-----
 4 files changed, 63 insertions(+), 17 deletions(-)

diff --git a/listener/shadowsocks/udp.go b/listener/shadowsocks/udp.go
index 3f058406..ef67d4e8 100644
--- a/listener/shadowsocks/udp.go
+++ b/listener/shadowsocks/udp.go
@@ -32,7 +32,7 @@ func NewUDP(addr string, pickCipher core.Cipher, in chan<- C.PacketAdapter) (*UD
 	conn := pickCipher.PacketConn(l)
 	go func() {
 		for {
-			buf := pool.Get(pool.RelayBufferSize)
+			buf := pool.Get(pool.UDPBufferSize)
 			n, remoteAddr, err := conn.ReadFrom(buf)
 			if err != nil {
 				pool.Put(buf)
diff --git a/listener/sing/sing.go b/listener/sing/sing.go
index 4a86dc82..7292df33 100644
--- a/listener/sing/sing.go
+++ b/listener/sing/sing.go
@@ -116,11 +116,26 @@ func (h *ListenerHandler) NewPacketConnection(ctx context.Context, conn network.
 		defer mutex.Unlock()
 		conn2 = nil
 	}()
+	readWaiter, isReadWaiter := bufio.CreatePacketReadWaiter(conn)
 	for {
-		buff := buf.NewPacket() // do not use stack buffer
-		dest, err := conn.ReadPacket(buff)
+		var (
+			buff *buf.Buffer
+			dest M.Socksaddr
+			err  error
+		)
+		newBuffer := func() *buf.Buffer {
+			buff = buf.NewPacket() // do not use stack buffer
+			return buff
+		}
+		if isReadWaiter {
+			dest, err = readWaiter.WaitReadPacket(newBuffer)
+		} else {
+			dest, err = conn.ReadPacket(newBuffer())
+		}
 		if err != nil {
-			buff.Release()
+			if buff != nil {
+				buff.Release()
+			}
 			if ShouldIgnorePacketError(err) {
 				break
 			}
diff --git a/listener/sing_shadowsocks/server.go b/listener/sing_shadowsocks/server.go
index c7e05bb5..31b342e8 100644
--- a/listener/sing_shadowsocks/server.go
+++ b/listener/sing_shadowsocks/server.go
@@ -21,7 +21,7 @@ import (
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/buf"
 	"github.com/sagernet/sing/common/bufio"
-	"github.com/sagernet/sing/common/metadata"
+	M "github.com/sagernet/sing/common/metadata"
 )
 
 type Listener struct {
@@ -92,19 +92,34 @@ func New(config LC.ShadowsocksServer, tcpIn chan<- C.ConnContext, udpIn chan<- C
 
 			go func() {
 				conn := bufio.NewPacketConn(ul)
+				readWaiter, isReadWaiter := bufio.CreatePacketReadWaiter(conn)
 				for {
-					buff := buf.NewPacket()
-					remoteAddr, err := conn.ReadPacket(buff)
+					var (
+						buff *buf.Buffer
+						dest M.Socksaddr
+						err  error
+					)
+					newBuffer := func() *buf.Buffer {
+						buff = buf.NewPacket() // do not use stack buffer
+						return buff
+					}
+					if isReadWaiter {
+						dest, err = readWaiter.WaitReadPacket(newBuffer)
+					} else {
+						dest, err = conn.ReadPacket(newBuffer())
+					}
 					if err != nil {
-						buff.Release()
+						if buff != nil {
+							buff.Release()
+						}
 						if sl.closed {
 							break
 						}
 						continue
 					}
-					_ = sl.service.NewPacket(context.TODO(), conn, buff, metadata.Metadata{
+					_ = sl.service.NewPacket(context.TODO(), conn, buff, M.Metadata{
 						Protocol: "shadowsocks",
-						Source:   remoteAddr,
+						Source:   dest,
 					})
 				}
 			}()
@@ -170,9 +185,9 @@ func (l *Listener) AddrList() (addrList []net.Addr) {
 
 func (l *Listener) HandleConn(conn net.Conn, in chan<- C.ConnContext, additions ...inbound.Addition) {
 	ctx := sing.WithAdditions(context.TODO(), additions...)
-	err := l.service.NewConnection(ctx, conn, metadata.Metadata{
+	err := l.service.NewConnection(ctx, conn, M.Metadata{
 		Protocol: "shadowsocks",
-		Source:   metadata.ParseSocksaddr(conn.RemoteAddr().String()),
+		Source:   M.ParseSocksaddr(conn.RemoteAddr().String()),
 	})
 	if err != nil {
 		_ = conn.Close()
diff --git a/listener/sing_tun/dns.go b/listener/sing_tun/dns.go
index dc33be91..fcf0cc9c 100644
--- a/listener/sing_tun/dns.go
+++ b/listener/sing_tun/dns.go
@@ -17,6 +17,7 @@ import (
 	D "github.com/miekg/dns"
 
 	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
 	M "github.com/sagernet/sing/common/metadata"
 	"github.com/sagernet/sing/common/network"
 )
@@ -108,14 +109,29 @@ func (h *ListenerHandler) NewPacketConnection(ctx context.Context, conn network.
 			defer mutex.Unlock()
 			conn2 = nil
 		}()
+		readWaiter, isReadWaiter := bufio.CreatePacketReadWaiter(conn)
 		for {
-			// safe size which is 1232 from https://dnsflagday.net/2020/.
-			// so 2048 is enough
-			buff := buf.NewSize(2 * 1024)
+			var (
+				buff *buf.Buffer
+				dest M.Socksaddr
+				err  error
+			)
+			newBuffer := func() *buf.Buffer {
+				// safe size which is 1232 from https://dnsflagday.net/2020/.
+				// so 2048 is enough
+				buff = buf.NewSize(2 * 1024)
+				return buff
+			}
 			_ = conn.SetReadDeadline(time.Now().Add(DefaultDnsReadTimeout))
-			dest, err := conn.ReadPacket(buff)
+			if isReadWaiter {
+				dest, err = readWaiter.WaitReadPacket(newBuffer)
+			} else {
+				dest, err = conn.ReadPacket(newBuffer())
+			}
 			if err != nil {
-				buff.Release()
+				if buff != nil {
+					buff.Release()
+				}
 				if sing.ShouldIgnorePacketError(err) {
 					break
 				}