// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package net import ( "os" "syscall" ) func setDefaultSockopts(s syscall.Handle, family, sotype int, ipv6only bool) error { if family == syscall.AF_INET6 && sotype != syscall.SOCK_RAW { // Allow both IP versions even if the OS default // is otherwise. Note that some operating systems // never admit this option. syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, boolint(ipv6only)) } if (sotype == syscall.SOCK_DGRAM || sotype == syscall.SOCK_RAW) && family != syscall.AF_UNIX && family != syscall.AF_INET6 { // Allow broadcast. return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)) } return nil } func setDefaultListenerSockopts(s syscall.Handle) error { // Windows will reuse recently-used addresses by default. // SO_REUSEADDR should not be used here, as it allows // a socket to forcibly bind to a port in use by another socket. // This could lead to a non-deterministic behavior, where // connection requests over the port cannot be guaranteed // to be handled by the correct socket. return nil } func setDefaultMulticastSockopts(s syscall.Handle) error { // Allow multicast UDP and raw IP datagram sockets to listen // concurrently across multiple listeners. return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)) }