Пример #1
0
func neighHandle(neigh *Neigh, req *nl.NetlinkRequest) error {
	var family int
	if neigh.Family > 0 {
		family = neigh.Family
	} else {
		family = nl.GetIPFamily(neigh.IP)
	}

	msg := Ndmsg{
		Family: uint8(family),
		Index:  uint32(neigh.LinkIndex),
		State:  uint16(neigh.State),
		Type:   uint8(neigh.Type),
		Flags:  uint8(neigh.Flags),
	}
	req.AddData(&msg)

	ipData := neigh.IP.To4()
	if ipData == nil {
		ipData = neigh.IP.To16()
	}

	dstData := nl.NewRtAttr(NDA_DST, ipData)
	req.AddData(dstData)

	if neigh.Flags != NTF_PROXY || neigh.HardwareAddr != nil {
		hwData := nl.NewRtAttr(NDA_LLADDR, []byte(neigh.HardwareAddr))
		req.AddData(hwData)
	}

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Пример #2
0
func rawIPData(ip net.IP) []byte {
	family := nl.GetIPFamily(ip)
	if family == nl.FAMILY_V4 {
		return ip.To4()
	}

	return ip
}
Пример #3
0
func (h *Handle) addrHandle(link Link, addr *Addr, req *nl.NetlinkRequest) error {
	base := link.Attrs()
	if addr.Label != "" && !strings.HasPrefix(addr.Label, base.Name) {
		return fmt.Errorf("label must begin with interface name")
	}
	h.ensureIndex(base)

	family := nl.GetIPFamily(addr.IP)

	msg := nl.NewIfAddrmsg(family)
	msg.Index = uint32(base.Index)
	msg.Scope = uint8(addr.Scope)
	prefixlen, _ := addr.Mask.Size()
	msg.Prefixlen = uint8(prefixlen)
	req.AddData(msg)

	var localAddrData []byte
	if family == FAMILY_V4 {
		localAddrData = addr.IP.To4()
	} else {
		localAddrData = addr.IP.To16()
	}

	localData := nl.NewRtAttr(syscall.IFA_LOCAL, localAddrData)
	req.AddData(localData)
	var peerAddrData []byte
	if addr.Peer != nil {
		if family == FAMILY_V4 {
			peerAddrData = addr.Peer.IP.To4()
		} else {
			peerAddrData = addr.Peer.IP.To16()
		}
	} else {
		peerAddrData = localAddrData
	}

	addressData := nl.NewRtAttr(syscall.IFA_ADDRESS, peerAddrData)
	req.AddData(addressData)

	if addr.Flags != 0 {
		if addr.Flags <= 0xff {
			msg.IfAddrmsg.Flags = uint8(addr.Flags)
		} else {
			b := make([]byte, 4)
			native.PutUint32(b, uint32(addr.Flags))
			flagsData := nl.NewRtAttr(IFA_FLAGS, b)
			req.AddData(flagsData)
		}
	}

	if addr.Label != "" {
		labelData := nl.NewRtAttr(syscall.IFA_LABEL, nl.ZeroTerminated(addr.Label))
		req.AddData(labelData)
	}

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Пример #4
0
func selFromPolicy(sel *nl.XfrmSelector, policy *XfrmPolicy) {
	sel.Family = uint16(nl.GetIPFamily(policy.Dst.IP))
	sel.Daddr.FromIP(policy.Dst.IP)
	sel.Saddr.FromIP(policy.Src.IP)
	prefixlenD, _ := policy.Dst.Mask.Size()
	sel.PrefixlenD = uint8(prefixlenD)
	prefixlenS, _ := policy.Src.Mask.Size()
	sel.PrefixlenS = uint8(prefixlenS)
}
Пример #5
0
// RouteGet gets a route to a specific destination from the host system.
// Equivalent to: 'ip route get'.
func RouteGet(destination net.IP) ([]Route, error) {
	req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
	family := nl.GetIPFamily(destination)
	var destinationData []byte
	var bitlen uint8
	if family == FAMILY_V4 {
		destinationData = destination.To4()
		bitlen = 32
	} else {
		destinationData = destination.To16()
		bitlen = 128
	}
	msg := &nl.RtMsg{}
	msg.Family = uint8(family)
	msg.Dst_len = bitlen
	req.AddData(msg)

	rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
	req.AddData(rtaDst)

	msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
	if err != nil {
		return nil, err
	}

	native := nl.NativeEndian()
	var res []Route
	for _, m := range msgs {
		msg := nl.DeserializeRtMsg(m)
		attrs, err := nl.ParseRouteAttr(m[msg.Len():])
		if err != nil {
			return nil, err
		}

		route := Route{}
		for _, attr := range attrs {
			switch attr.Attr.Type {
			case syscall.RTA_GATEWAY:
				route.Gw = net.IP(attr.Value)
			case syscall.RTA_PREFSRC:
				route.Src = net.IP(attr.Value)
			case syscall.RTA_DST:
				route.Dst = &net.IPNet{
					IP:   attr.Value,
					Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
				}
			case syscall.RTA_OIF:
				routeIndex := int(native.Uint32(attr.Value[0:4]))
				route.LinkIndex = routeIndex
			}
		}
		res = append(res, route)
	}
	return res, nil

}
Пример #6
0
func (h *Handle) xfrmStateAddOrUpdate(state *XfrmState, nlProto int) error {
	// A state with spi 0 can't be deleted so don't allow it to be set
	if state.Spi == 0 {
		return fmt.Errorf("Spi must be set when adding xfrm state.")
	}
	req := h.newNetlinkRequest(nlProto, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)

	msg := &nl.XfrmUsersaInfo{}
	msg.Family = uint16(nl.GetIPFamily(state.Dst))
	msg.Id.Daddr.FromIP(state.Dst)
	msg.Saddr.FromIP(state.Src)
	msg.Id.Proto = uint8(state.Proto)
	msg.Mode = uint8(state.Mode)
	msg.Id.Spi = nl.Swap32(uint32(state.Spi))
	msg.Reqid = uint32(state.Reqid)
	msg.ReplayWindow = uint8(state.ReplayWindow)
	limitsToLft(state.Limits, &msg.Lft)
	req.AddData(msg)

	if state.Auth != nil {
		out := nl.NewRtAttr(nl.XFRMA_ALG_AUTH_TRUNC, writeStateAlgoAuth(state.Auth))
		req.AddData(out)
	}
	if state.Crypt != nil {
		out := nl.NewRtAttr(nl.XFRMA_ALG_CRYPT, writeStateAlgo(state.Crypt))
		req.AddData(out)
	}
	if state.Aead != nil {
		out := nl.NewRtAttr(nl.XFRMA_ALG_AEAD, writeStateAlgoAead(state.Aead))
		req.AddData(out)
	}
	if state.Encap != nil {
		encapData := make([]byte, nl.SizeofXfrmEncapTmpl)
		encap := nl.DeserializeXfrmEncapTmpl(encapData)
		encap.EncapType = uint16(state.Encap.Type)
		encap.EncapSport = nl.Swap16(uint16(state.Encap.SrcPort))
		encap.EncapDport = nl.Swap16(uint16(state.Encap.DstPort))
		encap.EncapOa.FromIP(state.Encap.OriginalAddress)
		out := nl.NewRtAttr(nl.XFRMA_ENCAP, encapData)
		req.AddData(out)
	}
	if state.Mark != nil {
		out := nl.NewRtAttr(nl.XFRMA_MARK, writeMark(state.Mark))
		req.AddData(out)
	}

	_, err := req.Execute(syscall.NETLINK_XFRM, 0)
	return err
}
Пример #7
0
// XfrmStateDel will delete an xfrm state from the system. Note that
// the Algos are ignored when matching the state to delete.
// Equivalent to: `ip xfrm state del $state`
func XfrmStateDel(state *XfrmState) error {
	req := nl.NewNetlinkRequest(nl.XFRM_MSG_DELSA, syscall.NLM_F_ACK)

	msg := &nl.XfrmUsersaId{}
	msg.Daddr.FromIP(state.Dst)
	msg.Family = uint16(nl.GetIPFamily(state.Dst))
	msg.Proto = uint8(state.Proto)
	msg.Spi = nl.Swap32(uint32(state.Spi))
	req.AddData(msg)

	saddr := nl.XfrmAddress{}
	saddr.FromIP(state.Src)
	srcdata := nl.NewRtAttr(nl.XFRMA_SRCADDR, saddr.Serialize())

	req.AddData(srcdata)

	_, err := req.Execute(syscall.NETLINK_XFRM, 0)
	return err
}
Пример #8
0
func (h *Handle) xfrmStateGetOrDelete(state *XfrmState, nlProto int) (*XfrmState, error) {
	req := h.newNetlinkRequest(nlProto, syscall.NLM_F_ACK)

	msg := &nl.XfrmUsersaId{}
	msg.Family = uint16(nl.GetIPFamily(state.Dst))
	msg.Daddr.FromIP(state.Dst)
	msg.Proto = uint8(state.Proto)
	msg.Spi = nl.Swap32(uint32(state.Spi))
	req.AddData(msg)

	if state.Mark != nil {
		out := nl.NewRtAttr(nl.XFRMA_MARK, writeMark(state.Mark))
		req.AddData(out)
	}
	if state.Src != nil {
		out := nl.NewRtAttr(nl.XFRMA_SRCADDR, state.Src.To16())
		req.AddData(out)
	}

	resType := nl.XFRM_MSG_NEWSA
	if nlProto == nl.XFRM_MSG_DELSA {
		resType = 0
	}

	msgs, err := req.Execute(syscall.NETLINK_XFRM, uint16(resType))
	if err != nil {
		return nil, err
	}

	if nlProto == nl.XFRM_MSG_DELSA {
		return nil, nil
	}

	s, err := parseXfrmState(msgs[0], FAMILY_ALL)
	if err != nil {
		return nil, err
	}

	return s, nil
}
Пример #9
0
func selFromPolicy(sel *nl.XfrmSelector, policy *XfrmPolicy) {
	sel.Family = uint16(nl.FAMILY_V4)
	if policy.Dst != nil {
		sel.Family = uint16(nl.GetIPFamily(policy.Dst.IP))
		sel.Daddr.FromIP(policy.Dst.IP)
		prefixlenD, _ := policy.Dst.Mask.Size()
		sel.PrefixlenD = uint8(prefixlenD)
	}
	if policy.Src != nil {
		sel.Saddr.FromIP(policy.Src.IP)
		prefixlenS, _ := policy.Src.Mask.Size()
		sel.PrefixlenS = uint8(prefixlenS)
	}
	sel.Proto = uint8(policy.Proto)
	sel.Dport = nl.Swap16(uint16(policy.DstPort))
	sel.Sport = nl.Swap16(uint16(policy.SrcPort))
	if sel.Dport != 0 {
		sel.DportMask = ^uint16(0)
	}
	if sel.Sport != 0 {
		sel.SportMask = ^uint16(0)
	}
}
Пример #10
0
func addrHandle(link Link, addr *Addr, req *nl.NetlinkRequest) error {
	base := link.Attrs()
	if addr.Label != "" && !strings.HasPrefix(addr.Label, base.Name) {
		return fmt.Errorf("label must begin with interface name")
	}
	ensureIndex(base)

	family := nl.GetIPFamily(addr.IP)

	msg := nl.NewIfAddrmsg(family)
	msg.Index = uint32(base.Index)
	prefixlen, _ := addr.Mask.Size()
	msg.Prefixlen = uint8(prefixlen)
	req.AddData(msg)

	var addrData []byte
	if family == FAMILY_V4 {
		addrData = addr.IP.To4()
	} else {
		addrData = addr.IP.To16()
	}

	localData := nl.NewRtAttr(syscall.IFA_LOCAL, addrData)
	req.AddData(localData)

	addressData := nl.NewRtAttr(syscall.IFA_ADDRESS, addrData)
	req.AddData(addressData)

	if addr.Label != "" {
		labelData := nl.NewRtAttr(syscall.IFA_LABEL, nl.ZeroTerminated(addr.Label))
		req.AddData(labelData)
	}

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Пример #11
0
// RouteGet gets a route to a specific destination from the host system.
// Equivalent to: 'ip route get'.
func (h *Handle) RouteGet(destination net.IP) ([]Route, error) {
	req := h.newNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
	family := nl.GetIPFamily(destination)
	var destinationData []byte
	var bitlen uint8
	if family == FAMILY_V4 {
		destinationData = destination.To4()
		bitlen = 32
	} else {
		destinationData = destination.To16()
		bitlen = 128
	}
	msg := &nl.RtMsg{}
	msg.Family = uint8(family)
	msg.Dst_len = bitlen
	req.AddData(msg)

	rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
	req.AddData(rtaDst)

	msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
	if err != nil {
		return nil, err
	}

	var res []Route
	for _, m := range msgs {
		route, err := deserializeRoute(m)
		if err != nil {
			return nil, err
		}
		res = append(res, route)
	}
	return res, nil

}
Пример #12
0
func (h *Handle) routeHandle(route *Route, req *nl.NetlinkRequest, msg *nl.RtMsg) error {
	if (route.Dst == nil || route.Dst.IP == nil) && route.Src == nil && route.Gw == nil {
		return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
	}

	family := -1
	var rtAttrs []*nl.RtAttr

	if route.Dst != nil && route.Dst.IP != nil {
		dstLen, _ := route.Dst.Mask.Size()
		msg.Dst_len = uint8(dstLen)
		dstFamily := nl.GetIPFamily(route.Dst.IP)
		family = dstFamily
		var dstData []byte
		if dstFamily == FAMILY_V4 {
			dstData = route.Dst.IP.To4()
		} else {
			dstData = route.Dst.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
	}

	if route.Src != nil {
		srcFamily := nl.GetIPFamily(route.Src)
		if family != -1 && family != srcFamily {
			return fmt.Errorf("source and destination ip are not the same IP family")
		}
		family = srcFamily
		var srcData []byte
		if srcFamily == FAMILY_V4 {
			srcData = route.Src.To4()
		} else {
			srcData = route.Src.To16()
		}
		// The commonly used src ip for routes is actually PREFSRC
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PREFSRC, srcData))
	}

	if route.Gw != nil {
		gwFamily := nl.GetIPFamily(route.Gw)
		if family != -1 && family != gwFamily {
			return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
		}
		family = gwFamily
		var gwData []byte
		if gwFamily == FAMILY_V4 {
			gwData = route.Gw.To4()
		} else {
			gwData = route.Gw.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_GATEWAY, gwData))
	}

	if len(route.MultiPath) > 0 {
		buf := []byte{}
		for _, nh := range route.MultiPath {
			rtnh := &nl.RtNexthop{
				RtNexthop: syscall.RtNexthop{
					Hops:    uint8(nh.Hops),
					Ifindex: int32(nh.LinkIndex),
					Len:     uint16(syscall.SizeofRtNexthop),
				},
			}
			var gwData []byte
			if nh.Gw != nil {
				gwFamily := nl.GetIPFamily(nh.Gw)
				if family != -1 && family != gwFamily {
					return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
				}
				var gw *nl.RtAttr
				if gwFamily == FAMILY_V4 {
					gw = nl.NewRtAttr(syscall.RTA_GATEWAY, []byte(nh.Gw.To4()))
				} else {
					gw = nl.NewRtAttr(syscall.RTA_GATEWAY, []byte(nh.Gw.To16()))
				}
				gwData := gw.Serialize()
				rtnh.Len += uint16(len(gwData))
			}
			buf = append(buf, rtnh.Serialize()...)
			buf = append(buf, gwData...)
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_MULTIPATH, buf))
	}

	if route.Table > 0 {
		if route.Table >= 256 {
			msg.Table = syscall.RT_TABLE_UNSPEC
			b := make([]byte, 4)
			native.PutUint32(b, uint32(route.Table))
			rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_TABLE, b))
		} else {
			msg.Table = uint8(route.Table)
		}
	}

	if route.Priority > 0 {
		b := make([]byte, 4)
		native.PutUint32(b, uint32(route.Priority))
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PRIORITY, b))
	}
	if route.Tos > 0 {
		msg.Tos = uint8(route.Tos)
	}
	if route.Protocol > 0 {
		msg.Protocol = uint8(route.Protocol)
	}
	if route.Type > 0 {
		msg.Type = uint8(route.Type)
	}

	msg.Flags = uint32(route.Flags)
	msg.Scope = uint8(route.Scope)
	msg.Family = uint8(family)
	req.AddData(msg)
	for _, attr := range rtAttrs {
		req.AddData(attr)
	}

	var (
		b      = make([]byte, 4)
		native = nl.NativeEndian()
	)
	native.PutUint32(b, uint32(route.LinkIndex))

	req.AddData(nl.NewRtAttr(syscall.RTA_OIF, b))

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Пример #13
0
func ruleHandle(rule *Rule, req *nl.NetlinkRequest) error {
	msg := nl.NewRtMsg()
	msg.Family = syscall.AF_INET
	var dstFamily uint8

	var rtAttrs []*nl.RtAttr
	if rule.Dst != nil && rule.Dst.IP != nil {
		dstLen, _ := rule.Dst.Mask.Size()
		msg.Dst_len = uint8(dstLen)
		msg.Family = uint8(nl.GetIPFamily(rule.Dst.IP))
		dstFamily = msg.Family
		var dstData []byte
		if msg.Family == syscall.AF_INET {
			dstData = rule.Dst.IP.To4()
		} else {
			dstData = rule.Dst.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
	}

	if rule.Src != nil && rule.Src.IP != nil {
		msg.Family = uint8(nl.GetIPFamily(rule.Src.IP))
		if dstFamily != 0 && dstFamily != msg.Family {
			return fmt.Errorf("source and destination ip are not the same IP family")
		}
		srcLen, _ := rule.Src.Mask.Size()
		msg.Src_len = uint8(srcLen)
		var srcData []byte
		if msg.Family == syscall.AF_INET {
			srcData = rule.Src.IP.To4()
		} else {
			srcData = rule.Src.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_SRC, srcData))
	}

	if rule.Table >= 0 {
		msg.Table = uint8(rule.Table)
		if rule.Table >= 256 {
			msg.Table = syscall.RT_TABLE_UNSPEC
		}
	}

	req.AddData(msg)
	for i := range rtAttrs {
		req.AddData(rtAttrs[i])
	}

	var (
		b      = make([]byte, 4)
		native = nl.NativeEndian()
	)

	if rule.Priority >= 0 {
		native.PutUint32(b, uint32(rule.Priority))
		req.AddData(nl.NewRtAttr(nl.FRA_PRIORITY, b))
	}
	if rule.Mark >= 0 {
		native.PutUint32(b, uint32(rule.Mark))
		req.AddData(nl.NewRtAttr(nl.FRA_FWMARK, b))
	}
	if rule.Mask >= 0 {
		native.PutUint32(b, uint32(rule.Mask))
		req.AddData(nl.NewRtAttr(nl.FRA_FWMASK, b))
	}
	if rule.Flow >= 0 {
		native.PutUint32(b, uint32(rule.Flow))
		req.AddData(nl.NewRtAttr(nl.FRA_FLOW, b))
	}
	if rule.TunID > 0 {
		native.PutUint32(b, uint32(rule.TunID))
		req.AddData(nl.NewRtAttr(nl.FRA_TUN_ID, b))
	}
	if rule.Table >= 256 {
		native.PutUint32(b, uint32(rule.Table))
		req.AddData(nl.NewRtAttr(nl.FRA_TABLE, b))
	}
	if msg.Table > 0 {
		if rule.SuppressPrefixlen >= 0 {
			native.PutUint32(b, uint32(rule.SuppressPrefixlen))
			req.AddData(nl.NewRtAttr(nl.FRA_SUPPRESS_PREFIXLEN, b))
		}
		if rule.SuppressIfgroup >= 0 {
			native.PutUint32(b, uint32(rule.SuppressIfgroup))
			req.AddData(nl.NewRtAttr(nl.FRA_SUPPRESS_IFGROUP, b))
		}
	}
	if rule.IifName != "" {
		req.AddData(nl.NewRtAttr(nl.FRA_IIFNAME, []byte(rule.IifName)))
	}
	if rule.OifName != "" {
		req.AddData(nl.NewRtAttr(nl.FRA_OIFNAME, []byte(rule.OifName)))
	}
	if rule.Goto >= 0 {
		msg.Type = nl.FR_ACT_NOP
		native.PutUint32(b, uint32(rule.Goto))
		req.AddData(nl.NewRtAttr(nl.FRA_GOTO, b))
	}

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Пример #14
0
func routeHandle(route *Route, req *nl.NetlinkRequest, msg *nl.RtMsg) error {
	if (route.Dst == nil || route.Dst.IP == nil) && route.Src == nil && route.Gw == nil {
		return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
	}

	msg.Scope = uint8(route.Scope)
	msg.Flags = uint32(route.Flags)
	family := -1
	var rtAttrs []*nl.RtAttr

	if route.Dst != nil && route.Dst.IP != nil {
		dstLen, _ := route.Dst.Mask.Size()
		msg.Dst_len = uint8(dstLen)
		dstFamily := nl.GetIPFamily(route.Dst.IP)
		family = dstFamily
		var dstData []byte
		if dstFamily == FAMILY_V4 {
			dstData = route.Dst.IP.To4()
		} else {
			dstData = route.Dst.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
	}

	if route.Src != nil {
		srcFamily := nl.GetIPFamily(route.Src)
		if family != -1 && family != srcFamily {
			return fmt.Errorf("source and destination ip are not the same IP family")
		}
		family = srcFamily
		var srcData []byte
		if srcFamily == FAMILY_V4 {
			srcData = route.Src.To4()
		} else {
			srcData = route.Src.To16()
		}
		// The commonly used src ip for routes is actually PREFSRC
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PREFSRC, srcData))
	}

	if route.Gw != nil {
		gwFamily := nl.GetIPFamily(route.Gw)
		if family != -1 && family != gwFamily {
			return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
		}
		family = gwFamily
		var gwData []byte
		if gwFamily == FAMILY_V4 {
			gwData = route.Gw.To4()
		} else {
			gwData = route.Gw.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_GATEWAY, gwData))
	}

	msg.Family = uint8(family)

	req.AddData(msg)
	for _, attr := range rtAttrs {
		req.AddData(attr)
	}

	var (
		b      = make([]byte, 4)
		native = nl.NativeEndian()
	)
	native.PutUint32(b, uint32(route.LinkIndex))

	req.AddData(nl.NewRtAttr(syscall.RTA_OIF, b))

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}