| // 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. | 
 |  | 
 | //go: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) | 
 | } |