--- libgo/go/net/interface_bsdsunix.go.orig	2016-10-24 12:27:04 UTC
+++ libgo/go/net/interface_bsdsunix.go
@@ -0,0 +1,63 @@
+// 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.
+
+package net
+
+import (
+	"os"
+	"syscall"
+)
+
+// interfaceMulticastAddrTable returns addresses for a specific
+// interface.
+func interfaceMulticastAddrTable(ifi *Interface) ([]Addr, error) {
+	tab, err := syscall.RouteRIB(syscall.NET_RT_IFMALIST, ifi.Index)
+	if err != nil {
+		return nil, os.NewSyscallError("route rib", err)
+	}
+	msgs, err := syscall.ParseRoutingMessage(tab)
+	if err != nil {
+		return nil, os.NewSyscallError("route message", err)
+	}
+	var ifmat []Addr
+	for _, m := range msgs {
+		switch m := m.(type) {
+		case *syscall.InterfaceMulticastAddrMessage:
+			if ifi.Index == int(m.Header.Index) {
+				ifma, err := newMulticastAddr(ifi, m)
+				if err != nil {
+					return nil, err
+				}
+				ifmat = append(ifmat, ifma...)
+			}
+		}
+	}
+	return ifmat, nil
+}
+
+func newMulticastAddr(ifi *Interface, m *syscall.InterfaceMulticastAddrMessage) ([]Addr, error) {
+	sas, err := syscall.ParseRoutingSockaddr(m)
+	if err != nil {
+		return nil, os.NewSyscallError("route sockaddr", err)
+	}
+	var ifmat []Addr
+	for _, sa := range sas {
+		switch sa := sa.(type) {
+		case *syscall.SockaddrInet4:
+			ifma := &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])}
+			ifmat = append(ifmat, ifma.toAddr())
+		case *syscall.SockaddrInet6:
+			ifma := &IPAddr{IP: make(IP, IPv6len)}
+			copy(ifma.IP, sa.Addr[:])
+			// NOTE: KAME based IPv6 protocol stack usually embeds
+			// the interface index in the interface-local or link-
+			// local address as the kernel-internal form.
+			if ifma.IP.IsInterfaceLocalMulticast() || ifma.IP.IsLinkLocalMulticast() {
+				ifma.IP[2], ifma.IP[3] = 0, 0
+			}
+			ifmat = append(ifmat, ifma.toAddr())
+		}
+	}
+	return ifmat, nil
+}