Enable interface setting for socketopt under Windows (XTLS#2819)

* allow set interface under windows Signed-off-by: San Zhang <[email protected]> * polish code Signed-off-by: San Zhang <[email protected]> --------- Signed-off-by: San Zhang <[email protected]> Co-authored-by: San Zhang <[email protected]>
bitetrilo · Dec 17, 2023 · 5a5e615 · 5a5e615
1 parent c01a30e
commit 5a5e615
Showing 1 changed file with 26 additions and 1 deletion.
diff --git a/transport/internet/sockopt_windows.go b/transport/internet/sockopt_windows.go
@@ -1,11 +1,16 @@
 package internet
 
 import (
+ "encoding/binary"
+ "net"
  "syscall"
+ "unsafe"
 )
 
 const (
- TCP_FASTOPEN = 15
+ TCP_FASTOPEN = 15
+ IP_UNICAST_IF = 31
+ IPV6_UNICAST_IF = 31
 )
 
 func setTFO(fd syscall.Handle, tfo int) error {
@@ -21,6 +26,26 @@ func setTFO(fd syscall.Handle, tfo int) error {
 }
 
 func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
+ if config.Interface != "" {
+ inf, err := net.InterfaceByName(config.Interface)
+ if err != nil {
+ return newError("failed to find the interface").Base(err)
+ }
+ isV4 := (network == "tcp4")
+ if isV4 {
+ var bytes [4]byte
+ binary.BigEndian.PutUint32(bytes[:], uint32(inf.Index))
+ idx := *(*uint32)(unsafe.Pointer(&bytes[0]))
+ if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, IP_UNICAST_IF, int(idx)); err != nil {
+ return newError("failed to set IP_UNICAST_IF").Base(err)
+ }
+ } else {
+ if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_UNICAST_IF, inf.Index); err != nil {
+ return newError("failed to set IPV6_UNICAST_IF").Base(err)
+ }
+ }
+ }
+
  if isTCPSocket(network) {
  if err := setTFO(syscall.Handle(fd), config.ParseTFOValue()); err != nil {
  return err