From 5593fdee092de3c1c8afe53ee8ae17e8c54a8641 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=A7=8B=E3=81=AE=E3=81=8B=E3=81=88=E3=81=A7?=
 <autmaple@protonmail.com>
Date: Sat, 8 Oct 2022 09:03:51 +0800
Subject: [PATCH] Feat: add bind to device to Windows and Darwin (#1972)

---
 transport/internet/sockopt_darwin.go  | 28 +++++++++++++++++++++++++++
 transport/internet/sockopt_windows.go | 18 ++++++++++++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/transport/internet/sockopt_darwin.go b/transport/internet/sockopt_darwin.go
index 200b6abf8..18868405e 100644
--- a/transport/internet/sockopt_darwin.go
+++ b/transport/internet/sockopt_darwin.go
@@ -1,6 +1,8 @@
 package internet
 
 import (
+	"net"
+
 	"golang.org/x/sys/unix"
 )
 
@@ -42,6 +44,19 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 		}
 	}
 
+	if config.BindToDevice != "" {
+		iface, err := net.InterfaceByName(config.BindToDevice)
+		if err != nil {
+			return newError("failed to get interface ", config.BindToDevice).Base(err)
+		}
+		if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, iface.Index); err != nil {
+			return newError("failed to set IP_BOUND_IF", err)
+		}
+		if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, iface.Index); err != nil {
+			return newError("failed to set IPV6_BOUND_IF", err)
+		}
+	}
+
 	if config.TxBufSize != 0 {
 		if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUF, int(config.TxBufSize)); err != nil {
 			return newError("failed to set SO_SNDBUF").Base(err)
@@ -86,6 +101,19 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 		}
 	}
 
+	if config.BindToDevice != "" {
+		iface, err := net.InterfaceByName(config.BindToDevice)
+		if err != nil {
+			return newError("failed to get interface ", config.BindToDevice).Base(err)
+		}
+		if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, iface.Index); err != nil {
+			return newError("failed to set IP_BOUND_IF", err)
+		}
+		if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, iface.Index); err != nil {
+			return newError("failed to set IPV6_BOUND_IF", err)
+		}
+	}
+
 	if config.TxBufSize != 0 {
 		if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUF, int(config.TxBufSize)); err != nil {
 			return newError("failed to set SO_SNDBUF/SO_SNDBUFFORCE").Base(err)
diff --git a/transport/internet/sockopt_windows.go b/transport/internet/sockopt_windows.go
index eca97278a..6a4ec03fd 100644
--- a/transport/internet/sockopt_windows.go
+++ b/transport/internet/sockopt_windows.go
@@ -1,13 +1,16 @@
 package internet
 
 import (
+	"net"
 	"syscall"
 
 	"golang.org/x/sys/windows"
 )
 
 const (
-	TCP_FASTOPEN = 15 // nolint: revive,stylecheck
+	TCP_FASTOPEN    = 15 // nolint: revive,stylecheck
+	IP_UNICAST_IF   = 31 // nolint: revive,stylecheck
+	IPV6_UNICAST_IF = 31 // nolint: revive,stylecheck
 )
 
 func setTFO(fd syscall.Handle, settings SocketConfig_TCPFastOpenState) error {
@@ -36,6 +39,19 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 		}
 	}
 
+	if config.BindToDevice != "" {
+		iface, err := net.InterfaceByName(config.BindToDevice)
+		if err != nil {
+			return newError("failed to get interface ", config.BindToDevice).Base(err)
+		}
+		if err := windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, IP_UNICAST_IF, iface.Index); err != nil {
+			return newError("failed to set IP_UNICAST_IF", err)
+		}
+		if err := windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, IPV6_UNICAST_IF, iface.Index); err != nil {
+			return newError("failed to set IPV6_UNICAST_IF", err)
+		}
+	}
+
 	if config.TxBufSize != 0 {
 		if err := windows.SetsockoptInt(windows.Handle(fd), windows.SOL_SOCKET, windows.SO_SNDBUF, int(config.TxBufSize)); err != nil {
 			return newError("failed to set SO_SNDBUF").Base(err)