libgo/go/net/sockopt_bsd.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 // +build darwin freebsd netbsd openbsd
   6
   7 // Socket options for BSD variants
   8
   9 package net
  10
  11 import (
  12         "os"
  13         "syscall"
  14 )
  15
  16 func setDefaultSockopts(s, f, t int, ipv6only bool) error {
  17         switch f {
  18         case syscall.AF_INET6:
  19                 if ipv6only {
  20                         syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 1)
  21                 } else {
  22                         // Allow both IP versions even if the OS default
  23                         // is otherwise.  Note that some operating systems
  24                         // never admit this option.
  25                         syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
  26                 }
  27         }
  28         // Allow broadcast.
  29         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1)
  30         if err != nil {
  31                 return os.NewSyscallError("setsockopt", err)
  32         }
  33         return nil
  34 }
  35
  36 func setDefaultListenerSockopts(s int) error {
  37         // Allow reuse of recently-used addresses.
  38         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
  39         if err != nil {
  40                 return os.NewSyscallError("setsockopt", err)
  41         }
  42         return nil
  43 }
  44
  45 func setDefaultMulticastSockopts(s int) error {
  46         // Allow multicast UDP and raw IP datagram sockets to listen
  47         // concurrently across multiple listeners.
  48         err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
  49         if err != nil {
  50                 return os.NewSyscallError("setsockopt", err)
  51         }
  52         // Allow reuse of recently-used ports.
  53         // This option is supported only in descendants of 4.4BSD,
  54         // to make an effective multicast application that requires
  55         // quick draw possible.
  56         if syscall.SO_REUSEPORT != 0 {
  57                 err = syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
  58                 if err != nil {
  59                         return os.NewSyscallError("setsockopt", err)
  60                 }
  61         }
  62         return nil
  63 }