|  | // 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 aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris windows | 
|  |  | 
|  | package net | 
|  |  | 
|  | import ( | 
|  | "runtime" | 
|  | "syscall" | 
|  | ) | 
|  |  | 
|  | func joinIPv4Group(fd *netFD, ifi *Interface, ip IP) error { | 
|  | mreq := &syscall.IPMreq{Multiaddr: [4]byte{ip[0], ip[1], ip[2], ip[3]}} | 
|  | if err := setIPv4MreqToInterface(mreq, ifi); err != nil { | 
|  | return err | 
|  | } | 
|  | err := fd.pfd.SetsockoptIPMreq(syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq) | 
|  | runtime.KeepAlive(fd) | 
|  | return wrapSyscallError("setsockopt", err) | 
|  | } | 
|  |  | 
|  | func setIPv6MulticastInterface(fd *netFD, ifi *Interface) error { | 
|  | var v int | 
|  | if ifi != nil { | 
|  | v = ifi.Index | 
|  | } | 
|  | err := fd.pfd.SetsockoptInt(syscall.IPPROTO_IPV6, syscall.IPV6_MULTICAST_IF, v) | 
|  | runtime.KeepAlive(fd) | 
|  | return wrapSyscallError("setsockopt", err) | 
|  | } | 
|  |  | 
|  | func setIPv6MulticastLoopback(fd *netFD, v bool) error { | 
|  | err := fd.pfd.SetsockoptInt(syscall.IPPROTO_IPV6, syscall.IPV6_MULTICAST_LOOP, boolint(v)) | 
|  | runtime.KeepAlive(fd) | 
|  | return wrapSyscallError("setsockopt", err) | 
|  | } | 
|  |  | 
|  | func joinIPv6Group(fd *netFD, ifi *Interface, ip IP) error { | 
|  | mreq := &syscall.IPv6Mreq{} | 
|  | copy(mreq.Multiaddr[:], ip) | 
|  | if ifi != nil { | 
|  | mreq.Interface = uint32(ifi.Index) | 
|  | } | 
|  | err := fd.pfd.SetsockoptIPv6Mreq(syscall.IPPROTO_IPV6, syscall.IPV6_JOIN_GROUP, mreq) | 
|  | runtime.KeepAlive(fd) | 
|  | return wrapSyscallError("setsockopt", err) | 
|  | } |