|  | // 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. | 
|  |  | 
|  | // +build darwin dragonfly freebsd netbsd openbsd | 
|  |  | 
|  | package net | 
|  |  | 
|  | import ( | 
|  | "os" | 
|  | "syscall" | 
|  | ) | 
|  |  | 
|  | func setIPv4MulticastInterface(fd *netFD, ifi *Interface) error { | 
|  | ip, err := interfaceToIPv4Addr(ifi) | 
|  | if err != nil { | 
|  | return os.NewSyscallError("setsockopt", err) | 
|  | } | 
|  | var a [4]byte | 
|  | copy(a[:], ip.To4()) | 
|  | if err := fd.incref(); err != nil { | 
|  | return err | 
|  | } | 
|  | defer fd.decref() | 
|  | return os.NewSyscallError("setsockopt", syscall.SetsockoptInet4Addr(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_MULTICAST_IF, a)) | 
|  | } | 
|  |  | 
|  | func setIPv4MulticastLoopback(fd *netFD, v bool) error { | 
|  | if err := fd.incref(); err != nil { | 
|  | return err | 
|  | } | 
|  | defer fd.decref() | 
|  | return os.NewSyscallError("setsockopt", syscall.SetsockoptByte(fd.sysfd, syscall.IPPROTO_IP, syscall.IP_MULTICAST_LOOP, byte(boolint(v)))) | 
|  | } |