You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: route_netbsd.go
    path of file: ./repos/gccrs/libgo/go/syscall
    
    the code of the file until where you have to start completion: // 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 syscall

import "unsafe"

func (any *anyMessage) toRoutingMessage(b []byte) RoutingMessage {
	switch any.Type {
	case RTM_ADD, RTM_DELETE, RTM_CHANGE, RTM_GET, RTM_LOSING, RTM_REDIRECT, RTM_MISS, RTM_LOCK, RTM_RESOLVE:
		p := (*RouteMessage)(unsafe.Pointer(any))
		// We don't support sockaddr_mpls for now.
		p.Header.Addrs &= RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_GENMASK | RTA_IFA | RTA_IFP | RTA_BRD | RTA_AUTHOR
		return &RouteMessage{Header: p.Header, Data: b[SizeofRtMsghdr:any.Msglen]}
	case RTM_IFINFO:
		p := (*InterfaceMessage)(unsafe.Pointer(any))
		return &InterfaceMessage{Header: p.Header, Data: b[SizeofIfMsghdr:any.Msglen]}
	case RTM_IFANNOUNCE:
    
func (any *anyMessage) toRoutingMessage(b []byte) RoutingMessage {
	switch any.Type {
	case RTM_ADD, RTM_DELETE, RTM_CHANGE, RTM_GET, RTM_LOSING, RTM_REDIRECT, RTM_MISS, RTM_LOCK, RTM_RESOLVE:
		p := (*RouteMessage)(unsafe.Pointer(any))
		// We don't support sockaddr_mpls for now.
		p.Header.Addrs &= RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_GENMASK | RTA_IFA | RTA_IFP | RTA_BRD | RTA_AUTHOR
		return &RouteMessage{Header: p.Header, Data: b[SizeofRtMsghdr:any.Msglen]}
	case RTM_IFINFO:
		p := (*InterfaceMessage)(unsafe.Pointer(any))
		return &InterfaceMessage{Header: p.Header, Data: b[SizeofIfMsghdr:any.Msglen]}
	case RTM_IFANNOUNCE:
		p := (*InterfaceAnnounceMessage)(unsafe.Pointer(any))
		return &InterfaceAnnounceMessage{Header: p.Header}
	case RTM_NEWADDR, RTM_DELADDR:
		p := (*InterfaceAddrMessage)(unsafe.Pointer(any))
		return &InterfaceAddrMessage{Header: p.Header, Data: b[SizeofIfaMsghdr:any.Msglen]}
	}
	return nil
}