github.com/xushiwei/go@v0.0.0-20130601165731-2b9d83f45bc9/src/pkg/net/sockopt_bsd.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  // +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  	err = syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEPORT, 1)
    57  	if err != nil {
    58  		return os.NewSyscallError("setsockopt", err)
    59  	}
    60  	return nil
    61  }