1 // Copyright 2024 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 // This file implements sysSocket for platforms that provide a fast path for
6 // setting SetNonblock and CloseOnExec, but don't necessarily support it.
7 // Support for SOCK_* flags as part of the type parameter was added to Oracle
8 // Solaris in the 11.4 release. Thus, on releases prior to 11.4, we fall back
9 // to the combination of socket(3c) and fcntl(2).
10 11 package net
12 13 import (
14 "internal/poll"
15 "internal/syscall/unix"
16 "os"
17 "syscall"
18 )
19 20 // Wrapper around the socket system call that marks the returned file
21 // descriptor as nonblocking and close-on-exec.
22 func sysSocket(family, sotype, proto int) (int, error) {
23 // Perform a cheap test and try the fast path first.
24 if unix.SupportSockNonblockCloexec() {
25 s, err := socketFunc(family, sotype|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, proto)
26 if err != nil {
27 return -1, os.NewSyscallError("socket", err)
28 }
29 return s, nil
30 }
31 32 // See ../syscall/exec_unix.go for description of ForkLock.
33 syscall.ForkLock.RLock()
34 s, err := socketFunc(family, sotype, proto)
35 if err == nil {
36 syscall.CloseOnExec(s)
37 }
38 syscall.ForkLock.RUnlock()
39 if err != nil {
40 return -1, os.NewSyscallError("socket", err)
41 }
42 if err = syscall.SetNonblock(s, true); err != nil {
43 poll.CloseFunc(s)
44 return -1, os.NewSyscallError("setnonblock", err)
45 }
46 return s, nil
47 }
48