package syscall

import (
	"runtime"
	"unsafe"
)

var (
	freebsdConfArch       string // "machine $arch" line in kern.conftxt on freebsd
	minRoutingSockaddrLen = rsaAlignOf(0)
)

// Round the length of a raw sockaddr up to align it properly.
func rsaAlignOf(salen int) int {
	salign := sizeofPtr
	if darwin64Bit {
		// Darwin kernels require 32-bit aligned access to
		// routing facilities.
		salign = 4

		case AF_LINK:
			sa, err := parseSockaddrLink(b)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		case AF_INET, AF_INET6:
			sa, err := parseSockaddrInet(b, rsa.Family)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		default:
			sa, l, err := parseLinkLayerAddr(b)
			if err != nil {
				return nil, err
			}

		case AF_LINK:
			sa, err := parseSockaddrLink(b)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		case AF_INET, AF_INET6:
			sa, err := parseSockaddrInet(b, rsa.Family)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		default:
			sa, l, err := parseLinkLayerAddr(b)
			if err != nil {
				return nil, err
			}

package syscall

import "unsafe"

func (any *anyMessage) parseRouteMessage(b []byte) *RouteMessage {
	p := (*RouteMessage)(unsafe.Pointer(any))
	return &RouteMessage{Header: p.Header, Data: b[rsaAlignOf(int(unsafe.Offsetof(p.Header.Rmx))+SizeofRtMetrics):any.Msglen]}
}

func (any *anyMessage) parseInterfaceMessage(b []byte) *InterfaceMessage {
	p := (*InterfaceMessage)(unsafe.Pointer(any))

		case AF_LINK:
			sa, err := parseSockaddrLink(b)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		case AF_INET, AF_INET6:
			sa, err := parseSockaddrInet(b, rsa.Family)
			if err != nil {
				return nil, err
			}
			sas[i] = sa
			b = b[rsaAlignOf(int(rsa.Len)):]
		default:
			sa, l, err := parseLinkLayerAddr(b)
			if err != nil {
				return nil, err
			}

	off := int(unsafe.Offsetof(p.Header.Rmx)) + SizeofRtMetrics
	if freebsdConfArch == "amd64" {
		off += SizeofRtMetrics // rt_metrics on amd64 is simply doubled
	}
	return &RouteMessage{Header: p.Header, Data: b[rsaAlignOf(off):any.Msglen]}
}

func (any *anyMessage) parseInterfaceMessage(b []byte) *InterfaceMessage {
	p := (*InterfaceMessage)(unsafe.Pointer(any))
	// FreeBSD 10 and beyond have a restructured mbuf
	// packet header view.