libgo/go/net/sockopt_linux.go

   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 // Socket options for Linux
   6
   7 package net
   8
   9 import (
  10         "os"
  11         "syscall"
  12 )
  13
  14 func setDefaultSockopts(s, f, t int, ipv6only bool) error {
  15         switch f {
  16         case syscall.AF_INET6:
  17                 if ipv6only {
  18                         syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 1)
  19                 } else {
  20                         // Allow both IP versions even if the OS default
  21                         // is otherwise.  Note that some operating systems
  22                         // never admit this option.
  23                         syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
  24                 }
  25         }
  26         // Allow broadcast.
  27         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)
  28         if err != nil {
  29                 return os.NewSyscallError("setsockopt", err)
  30         }
  31         return nil
  32 }
  33
  34 func setDefaultListenerSockopts(s int) error {
  35         // Allow reuse of recently-used addresses.
  36         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
  37         if err != nil {
  38                 return os.NewSyscallError("setsockopt", err)
  39         }
  40         return nil
  41 }
  42
  43 func setDefaultMulticastSockopts(s int) error {
  44         // Allow multicast UDP and raw IP datagram sockets to listen
  45         // concurrently across multiple listeners.
  46         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
  47         if err != nil {
  48                 return os.NewSyscallError("setsockopt", err)
  49         }
  50         return nil
  51 }