github.com/m10x/go/src@v0.0.0-20220112094212-ba61592315da/net/sockopt_windows.go (about) 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 "os" 9 "syscall" 10 ) 11 12 func setDefaultSockopts(s syscall.Handle, family, sotype int, ipv6only bool) error { 13 if family == syscall.AF_INET6 && sotype != syscall.SOCK_RAW { 14 // Allow both IP versions even if the OS default 15 // is otherwise. Note that some operating systems 16 // never admit this option. 17 syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, boolint(ipv6only)) 18 } 19 if (sotype == syscall.SOCK_DGRAM || sotype == syscall.SOCK_RAW) && family != syscall.AF_UNIX && family != syscall.AF_INET6 { 20 // Allow broadcast. 21 return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)) 22 } 23 return nil 24 } 25 26 func setDefaultListenerSockopts(s syscall.Handle) error { 27 // Windows will reuse recently-used addresses by default. 28 // SO_REUSEADDR should not be used here, as it allows 29 // a socket to forcibly bind to a port in use by another socket. 30 // This could lead to a non-deterministic behavior, where 31 // connection requests over the port cannot be guaranteed 32 // to be handled by the correct socket. 33 return nil 34 } 35 36 func setDefaultMulticastSockopts(s syscall.Handle) error { 37 // Allow multicast UDP and raw IP datagram sockets to listen 38 // concurrently across multiple listeners. 39 return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)) 40 }