From 1e4547e26244e9e8130838272220c217f08d524f Mon Sep 17 00:00:00 2001
From: Darien Raymond <admin@v2ray.com>
Date: Tue, 11 Sep 2018 10:03:26 +0200
Subject: [PATCH] simplify tcp network detection

---
 transport/internet/sockopt.go         |  9 ++++++
 transport/internet/sockopt_darwin.go  |  5 ++-
 transport/internet/sockopt_linux.go   |  5 ++-
 transport/internet/sockopt_windows.go | 44 +++++++++++++--------------
 4 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/transport/internet/sockopt.go b/transport/internet/sockopt.go
index 604e4545..48d230dd 100644
--- a/transport/internet/sockopt.go
+++ b/transport/internet/sockopt.go
@@ -1 +1,10 @@
 package internet
+
+func isTCPSocket(network string) bool {
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		return true
+	default:
+		return false
+	}
+}
diff --git a/transport/internet/sockopt_darwin.go b/transport/internet/sockopt_darwin.go
index 7fb5eafe..3db792ca 100644
--- a/transport/internet/sockopt_darwin.go
+++ b/transport/internet/sockopt_darwin.go
@@ -1,7 +1,6 @@
 package internet
 
 import (
-	"strings"
 	"syscall"
 )
 
@@ -12,7 +11,7 @@ const (
 )
 
 func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
-	if strings.HasPrefix(network, "tcp") {
+	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
 			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, TCP_FASTOPEN_CLIENT); err != nil {
@@ -29,7 +28,7 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 }
 
 func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig) error {
-	if strings.HasPrefix(network, "tcp") {
+	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
 			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, TCP_FASTOPEN_SERVER); err != nil {
diff --git a/transport/internet/sockopt_linux.go b/transport/internet/sockopt_linux.go
index e3285e3e..31ea9036 100644
--- a/transport/internet/sockopt_linux.go
+++ b/transport/internet/sockopt_linux.go
@@ -1,7 +1,6 @@
 package internet
 
 import (
-	"strings"
 	"syscall"
 )
 
@@ -19,7 +18,7 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 		}
 	}
 
-	if strings.HasPrefix(network, "tcp") {
+	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
 			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_TCP, TCP_FASTOPEN_CONNECT, 1); err != nil {
@@ -36,7 +35,7 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 }
 
 func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig) error {
-	if strings.HasPrefix(network, "tcp") {
+	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
 			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_TCP, TCP_FASTOPEN, 1); err != nil {
diff --git a/transport/internet/sockopt_windows.go b/transport/internet/sockopt_windows.go
index dc22eff3..0bd4c3e3 100644
--- a/transport/internet/sockopt_windows.go
+++ b/transport/internet/sockopt_windows.go
@@ -1,7 +1,6 @@
 package internet
 
 import (
-	"strings"
 	"syscall"
 )
 
@@ -9,34 +8,35 @@ const (
 	TCP_FASTOPEN = 15
 )
 
-func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
-	if strings.HasPrefix(network, "tcp") {
-		switch config.Tfo {
-		case SocketConfig_Enable:
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 1); err != nil {
-				return err
-			}
-		case SocketConfig_Disable:
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 0); err != nil {
-				return err
-			}
+func setTFO(fd syscall.Handle, settings SocketConfig_TCPFastOpenState) error {
+	switch settings {
+	case SocketConfig_Enable:
+		if err := syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, TCP_FASTOPEN, 1); err != nil {
+			return err
 		}
+	case SocketConfig_Disable:
+		if err := syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, TCP_FASTOPEN, 0); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
+	if isTCPSocket(network) {
+		if err := setTFO(syscall.Hanle(fd), config.Tfo); err != nil {
+			return err
+		}
+
 	}
 
 	return nil
 }
 
 func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig) error {
-	if strings.HasPrefix(network, "tcp") {
-		switch config.Tfo {
-		case SocketConfig_Enable:
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 1); err != nil {
-				return err
-			}
-		case SocketConfig_Disable:
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 0); err != nil {
-				return err
-			}
+	if isTCPSocket(network) {
+		if err := setTFO(syscall.Hanle(fd), config.Tfo); err != nil {
+			return err
 		}
 	}