1 // Copyright 2013 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 and accept for platforms that 6 // provide a fast path for setting SetNonblock and CloseOnExec. 7 8 // +build dragonfly freebsd linux 9 10 package net 11 12 import ( 13 "internal/poll" 14 "os" 15 "syscall" 16 ) 17 18 // Wrapper around the socket system call that marks the returned file 19 // descriptor as nonblocking and close-on-exec. 20 func sysSocket(family, sotype, proto int) (int, error) { 21 s, err := socketFunc(family, sotype|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, proto) 22 // On Linux the SOCK_NONBLOCK and SOCK_CLOEXEC flags were 23 // introduced in 2.6.27 kernel and on FreeBSD both flags were 24 // introduced in 10 kernel. If we get an EINVAL error on Linux 25 // or EPROTONOSUPPORT error on FreeBSD, fall back to using 26 // socket without them. 27 switch err { 28 case nil: 29 return s, nil 30 default: 31 return -1, os.NewSyscallError("socket", err) 32 case syscall.EPROTONOSUPPORT, syscall.EINVAL: 33 } 34 35 // See ../syscall/exec_unix.go for description of ForkLock. 36 syscall.ForkLock.RLock() 37 s, err = socketFunc(family, sotype, proto) 38 if err == nil { 39 syscall.CloseOnExec(s) 40 } 41 syscall.ForkLock.RUnlock() 42 if err != nil { 43 return -1, os.NewSyscallError("socket", err) 44 } 45 if err = syscall.SetNonblock(s, true); err != nil { 46 poll.CloseFunc(s) 47 return -1, os.NewSyscallError("setnonblock", err) 48 } 49 return s, nil 50 } 51
