mark_unix.go raw

   1  //go:build linux || openbsd || freebsd
   2  
   3  /* SPDX-License-Identifier: MIT
   4   *
   5   * Copyright (C) 2017-2025 WireGuard LLC. All Rights Reserved.
   6   */
   7  
   8  package conn
   9  
  10  import (
  11  	"runtime"
  12  
  13  	"golang.org/x/sys/unix"
  14  )
  15  
  16  var fwmarkIoctl int
  17  
  18  func init() {
  19  	switch runtime.GOOS {
  20  	case "linux", "android":
  21  		fwmarkIoctl = 36 /* unix.SO_MARK */
  22  	case "freebsd":
  23  		fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
  24  	case "openbsd":
  25  		fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
  26  	}
  27  }
  28  
  29  func (s *StdNetBind) SetMark(mark uint32) error {
  30  	var operr error
  31  	if fwmarkIoctl == 0 {
  32  		return nil
  33  	}
  34  	if s.ipv4 != nil {
  35  		fd, err := s.ipv4.SyscallConn()
  36  		if err != nil {
  37  			return err
  38  		}
  39  		err = fd.Control(func(fd uintptr) {
  40  			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
  41  		})
  42  		if err == nil {
  43  			err = operr
  44  		}
  45  		if err != nil {
  46  			return err
  47  		}
  48  	}
  49  	if s.ipv6 != nil {
  50  		fd, err := s.ipv6.SyscallConn()
  51  		if err != nil {
  52  			return err
  53  		}
  54  		err = fd.Control(func(fd uintptr) {
  55  			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
  56  		})
  57  		if err == nil {
  58  			err = operr
  59  		}
  60  		if err != nil {
  61  			return err
  62  		}
  63  	}
  64  	return nil
  65  }
  66