1 // Copyright 2011 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 5 package net
6 7 import (
8 "internal/syscall/windows"
9 "os"
10 "syscall"
11 )
12 13 const _SO_TYPE = windows.SO_TYPE
14 15 func dupSocket(h syscall.Handle) (syscall.Handle, error) {
16 var info syscall.WSAProtocolInfo
17 err := windows.WSADuplicateSocket(h, uint32(syscall.Getpid()), &info)
18 if err != nil {
19 return 0, err
20 }
21 return windows.WSASocket(-1, -1, -1, &info, 0, windows.WSA_FLAG_OVERLAPPED|windows.WSA_FLAG_NO_HANDLE_INHERIT)
22 }
23 24 func dupFileSocket(f *os.File) (syscall.Handle, error) {
25 // Call Fd to disassociate the IOCP from the handle,
26 // it is not safe to share a duplicated handle
27 // that is associated with IOCP.
28 // Don't use the returned fd, as it might be closed
29 // if f happens to be the last reference to the file.
30 f.Fd()
31 32 sc, err := f.SyscallConn()
33 if err != nil {
34 return 0, err
35 }
36 37 var h syscall.Handle
38 var syserr error
39 err = sc.Control(func(fd uintptr) {
40 h, syserr = dupSocket(syscall.Handle(fd))
41 })
42 if err != nil {
43 err = syserr
44 }
45 if err != nil {
46 return 0, err
47 }
48 return h, nil
49 }
50