From 6ed02b47bfce0f9531d6c3120bf45ca633862928 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Wed, 6 Dec 2023 20:48:32 +0800
Subject: [PATCH] Implement read waiter for ss2022 UDP

---
 go.mod                         |  4 ++--
 go.sum                         |  8 +++----
 shadowaead/method.go           |  8 +++++++
 shadowaead_2022/method_wait.go | 42 ++++++++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+), 6 deletions(-)
 create mode 100644 shadowaead_2022/method_wait.go

diff --git a/go.mod b/go.mod
index 8334d88..8496b22 100644
--- a/go.mod
+++ b/go.mod
@@ -3,12 +3,12 @@ module github.com/sagernet/sing-shadowsocks2
 go 1.18
 
 require (
-	github.com/sagernet/sing v0.2.17
+	github.com/sagernet/sing v0.2.19-0.20231206123939-86c131fc0547
 	golang.org/x/crypto v0.15.0
 	lukechampine.com/blake3 v1.2.1
 )
 
 require (
 	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
-	golang.org/x/sys v0.14.0 // indirect
+	golang.org/x/sys v0.15.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 0512153..6aeb7a5 100644
--- a/go.sum
+++ b/go.sum
@@ -1,10 +1,10 @@
 github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
-github.com/sagernet/sing v0.2.17 h1:vMPKb3MV0Aa5ws4dCJkRI8XEjrsUcDn810czd0FwmzI=
-github.com/sagernet/sing v0.2.17/go.mod h1:OL6k2F0vHmEzXz2KW19qQzu172FDgSbUSODylighuVo=
+github.com/sagernet/sing v0.2.19-0.20231206123939-86c131fc0547 h1:Mco2TffcdPMlmzbcGmbKd6Vm6dEBJH2VgjO6H1XfZzY=
+github.com/sagernet/sing v0.2.19-0.20231206123939-86c131fc0547/go.mod h1:Ce5LNojQOgOiWhiD8pPD6E9H7e2KgtOe3Zxx4Ou5u80=
 golang.org/x/crypto v0.15.0 h1:frVn1TEaCEaZcn3Tmd7Y2b5KKPaZ+I32Q2OA3kYp5TA=
 golang.org/x/crypto v0.15.0/go.mod h1:4ChreQoLWfG3xLDer1WdlH5NdlQ3+mwnQq1YTKY+72g=
-golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
-golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 lukechampine.com/blake3 v1.2.1 h1:YuqqRuaqsGV71BV/nm9xlI0MKUv4QC54jQnBChWbGnI=
 lukechampine.com/blake3 v1.2.1/go.mod h1:0OFRp7fBtAylGVCO40o87sbupkyIGgbpv1+M1k1LM6k=
diff --git a/shadowaead/method.go b/shadowaead/method.go
index ef24bfa..595f82b 100644
--- a/shadowaead/method.go
+++ b/shadowaead/method.go
@@ -350,6 +350,14 @@ func (c *clientPacketConn) RearHeadroom() int {
 	return shadowio.Overhead
 }
 
+func (c *clientPacketConn) ReaderMTU() int {
+	return MaxPacketSize
+}
+
+func (c *clientPacketConn) WriterMTU() int {
+	return MaxPacketSize
+}
+
 func (c *clientPacketConn) Upstream() any {
 	return c.AbstractConn
 }
diff --git a/shadowaead_2022/method_wait.go b/shadowaead_2022/method_wait.go
new file mode 100644
index 0000000..625e7e6
--- /dev/null
+++ b/shadowaead_2022/method_wait.go
@@ -0,0 +1,42 @@
+package shadowaead_2022
+
+import (
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var _ N.PacketReadWaitCreator = (*clientPacketConn)(nil)
+
+func (c *clientPacketConn) CreateReadWaiter() (N.PacketReadWaiter, bool) {
+	readWaiter, isReadWaiter := bufio.CreateReadWaiter(c.reader)
+	if !isReadWaiter {
+		return nil, false
+	}
+	return &clientPacketReadWaiter{c, readWaiter}, true
+}
+
+var _ N.PacketReadWaiter = (*clientPacketReadWaiter)(nil)
+
+type clientPacketReadWaiter struct {
+	*clientPacketConn
+	readWaiter N.ReadWaiter
+}
+
+func (w *clientPacketReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
+	w.readWaiter.InitializeReadWaiter(newBuffer)
+}
+
+func (w *clientPacketReadWaiter) WaitReadPacket() (buffer *buf.Buffer, destination M.Socksaddr, err error) {
+	buffer, err = w.readWaiter.WaitReadBuffer()
+	if err != nil {
+		return
+	}
+	destination, err = w.readPacket(buffer)
+	if err != nil {
+		buffer.Release()
+		return nil, M.Socksaddr{}, err
+	}
+	return
+}