From 455a7cdea047bf520e36fbacc46cbe8bfb678c75 Mon Sep 17 00:00:00 2001
From: notsure2 <notsure2@protonmail.com>
Date: Sat, 10 Jun 2023 15:46:51 +0300
Subject: [PATCH] Implement TCP_NODELAY in client and server tcp connections.

---
 internal/client/connector.go  | 17 +++++++++++++++++
 internal/client/piper.go      |  5 +++++
 internal/server/dispatcher.go | 19 +++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/internal/client/connector.go b/internal/client/connector.go
index 660862e..f3b41c0 100644
--- a/internal/client/connector.go
+++ b/internal/client/connector.go
@@ -4,6 +4,7 @@ import (
 	"net"
 	"sync"
 	"sync/atomic"
+	"syscall"
 	"time"
 
 	"github.com/cbeuw/Cloak/internal/common"
@@ -31,6 +32,22 @@ func MakeSession(connConfig RemoteConnConfig, authInfo AuthInfo, dialer common.D
 				goto makeconn
 			}
 
+			tcpConn := remoteConn.(*net.TCPConn)
+			syscallConn, err := tcpConn.SyscallConn()
+			if err != nil {
+				panic(err)
+			}
+
+			err = syscallConn.Control(func(fd uintptr) {
+				err = syscall.SetsockoptInt(common.Platformfd(fd), syscall.IPPROTO_TCP, syscall.TCP_NODELAY, 1)
+				if err != nil {
+					log.Errorf("setsocketopt TCP_NODELAY: %s\n", err)
+				}
+			})
+			if err != nil {
+				panic(err)
+			}
+
 			transportConn := connConfig.TransportMaker()
 			sk, err := transportConn.Handshake(remoteConn, authInfo)
 			if err != nil {
diff --git a/internal/client/piper.go b/internal/client/piper.go
index 744c2de..1927012 100644
--- a/internal/client/piper.go
+++ b/internal/client/piper.go
@@ -129,6 +129,11 @@ func RouteTCP(listener net.Listener, streamTimeout time.Duration, singleplex boo
 						log.Errorf("setsocketopt SO_RCVBUF: %s\n", err)
 					}
 				}
+
+				err = syscall.SetsockoptInt(common.Platformfd(fd), syscall.IPPROTO_TCP, syscall.TCP_NODELAY, 1)
+				if err != nil {
+					log.Errorf("setsocketopt TCP_NODELAY: %s\n", err)
+				}
 			})
 			if err != nil {
 				log.Fatal(err)
diff --git a/internal/server/dispatcher.go b/internal/server/dispatcher.go
index 4285ed3..2e499ed 100644
--- a/internal/server/dispatcher.go
+++ b/internal/server/dispatcher.go
@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"syscall"
 	"time"
 
 	"github.com/cbeuw/Cloak/internal/common"
@@ -294,6 +295,24 @@ func serveSession(sesh *mux.Session, ci ClientInfo, user *ActiveUser, sta *State
 		}
 		log.Tracef("%v endpoint has been successfully connected", ci.ProxyMethod)
 
+		tcpConn, ok := localConn.(*net.TCPConn)
+		if ok {
+			syscallConn, err := tcpConn.SyscallConn()
+			if err != nil {
+				return err
+			}
+
+			err = syscallConn.Control(func(fd uintptr) {
+				err = syscall.SetsockoptInt(common.Platformfd(fd), syscall.IPPROTO_TCP, syscall.TCP_NODELAY, 1)
+				if err != nil {
+					log.Errorf("setsocketopt TCP_NODELAY: %s\n", err)
+				}
+			})
+			if err != nil {
+				return err
+			}
+		}
+
 		go func() {
 			if _, err := common.Copy(localConn, newStream); err != nil {
 				log.Tracef("copying stream to proxy server: %v", err)