// ClassAdd will add a class to the system.
// Equivalent to: `tc class add $class`
func ClassAdd(class Class) error {
	req := nl.NewNetlinkRequest(syscall.RTM_NEWTCLASS, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
	base := class.Attrs()
	msg := &nl.TcMsg{
		Family:  nl.FAMILY_ALL,
		Ifindex: int32(base.LinkIndex),
		Handle:  base.Handle,
		Parent:  base.Parent,
	}
	req.AddData(msg)
	req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(class.Type())))

	options := nl.NewRtAttr(nl.TCA_OPTIONS, nil)
	if htb, ok := class.(*HtbClass); ok {
		opt := nl.TcHtbCopt{}
		opt.Rate.Rate = uint32(htb.Rate)
		opt.Ceil.Rate = uint32(htb.Ceil)
		opt.Buffer = htb.Buffer
		opt.Cbuffer = htb.Cbuffer
		opt.Quantum = htb.Quantum
		opt.Level = htb.Level
		opt.Prio = htb.Prio
		// TODO: Handle Debug properly. For now default to 0
		nl.NewRtAttrChild(options, nl.TCA_HTB_PARMS, opt.Serialize())
	}
	req.AddData(options)
	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}

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)

	hwData := nl.NewRtAttr(NDA_LLADDR, []byte(neigh.HardwareAddr))
	req.AddData(hwData)

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

// XfrmPolicyAdd will add an xfrm policy to the system.
// Equivalent to: `ip xfrm policy add $policy`
func XfrmPolicyAdd(policy *XfrmPolicy) error {
	req := nl.NewNetlinkRequest(nl.XFRM_MSG_NEWPOLICY, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)

	msg := &nl.XfrmUserpolicyInfo{}
	selFromPolicy(&msg.Sel, policy)
	msg.Priority = uint32(policy.Priority)
	msg.Index = uint32(policy.Index)
	msg.Dir = uint8(policy.Dir)
	msg.Lft.SoftByteLimit = nl.XFRM_INF
	msg.Lft.HardByteLimit = nl.XFRM_INF
	msg.Lft.SoftPacketLimit = nl.XFRM_INF
	msg.Lft.HardPacketLimit = nl.XFRM_INF
	req.AddData(msg)

	tmplData := make([]byte, nl.SizeofXfrmUserTmpl*len(policy.Tmpls))
	for i, tmpl := range policy.Tmpls {
		start := i * nl.SizeofXfrmUserTmpl
		userTmpl := nl.DeserializeXfrmUserTmpl(tmplData[start : start+nl.SizeofXfrmUserTmpl])
		userTmpl.XfrmId.Daddr.FromIP(tmpl.Dst)
		userTmpl.Saddr.FromIP(tmpl.Src)
		userTmpl.XfrmId.Proto = uint8(tmpl.Proto)
		userTmpl.Mode = uint8(tmpl.Mode)
		userTmpl.Reqid = uint32(tmpl.Reqid)
		userTmpl.Aalgos = ^uint32(0)
		userTmpl.Ealgos = ^uint32(0)
		userTmpl.Calgos = ^uint32(0)
	}
	if len(tmplData) > 0 {
		tmpls := nl.NewRtAttr(nl.XFRMA_TMPL, tmplData)
		req.AddData(tmpls)
	}

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

// QdiscAdd will add a qdisc to the system.
// Equivalent to: `tc qdisc add $qdisc`
func QdiscAdd(qdisc Qdisc) error {
	req := nl.NewNetlinkRequest(syscall.RTM_NEWQDISC, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
	base := qdisc.Attrs()
	msg := &nl.TcMsg{
		Family:  nl.FAMILY_ALL,
		Ifindex: int32(base.LinkIndex),
		Handle:  base.Handle,
		Parent:  base.Parent,
	}
	req.AddData(msg)
	req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(qdisc.Type())))

	options := nl.NewRtAttr(nl.TCA_OPTIONS, nil)
	if prio, ok := qdisc.(*Prio); ok {
		tcmap := nl.TcPrioMap{
			Bands:   int32(prio.Bands),
			Priomap: prio.PriorityMap,
		}
		options = nl.NewRtAttr(nl.TCA_OPTIONS, tcmap.Serialize())
	} else if tbf, ok := qdisc.(*Tbf); ok {
		opt := nl.TcTbfQopt{}
		// TODO: handle rate > uint32
		opt.Rate.Rate = uint32(tbf.Rate)
		opt.Limit = tbf.Limit
		opt.Buffer = tbf.Buffer
		nl.NewRtAttrChild(options, nl.TCA_TBF_PARMS, opt.Serialize())
	} else if htb, ok := qdisc.(*Htb); ok {
		opt := nl.TcHtbGlob{}
		opt.Version = htb.Version
		opt.Rate2Quantum = htb.Rate2Quantum
		opt.Defcls = htb.Defcls
		// TODO: Handle Debug properly. For now default to 0
		opt.Debug = htb.Debug
		opt.DirectPkts = htb.DirectPkts
		nl.NewRtAttrChild(options, nl.TCA_HTB_INIT, opt.Serialize())
		// nl.NewRtAttrChild(options, nl.TCA_HTB_DIRECT_QLEN, opt.Serialize())
	} else if _, ok := qdisc.(*Ingress); ok {
		// ingress filters must use the proper handle
		if msg.Parent != HANDLE_INGRESS {
			return fmt.Errorf("Ingress filters must set Parent to HANDLE_INGRESS")
		}
	}
	req.AddData(options)
	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}

// XfrmStateAdd will add an xfrm state to the system.
// Equivalent to: `ip xfrm state add $state`
func XfrmStateAdd(state *XfrmState) 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 := nl.NewNetlinkRequest(nl.XFRM_MSG_NEWSA, 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)
	msg.Lft.SoftByteLimit = nl.XFRM_INF
	msg.Lft.HardByteLimit = nl.XFRM_INF
	msg.Lft.SoftPacketLimit = nl.XFRM_INF
	msg.Lft.HardPacketLimit = nl.XFRM_INF
	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.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)
	}

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

// 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()
	res := make([]Route, 0)
	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

}

// FilterAdd will add a filter to the system.
// Equivalent to: `tc filter add $filter`
func FilterAdd(filter Filter) error {
	req := nl.NewNetlinkRequest(syscall.RTM_NEWTFILTER, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
	base := filter.Attrs()
	msg := &nl.TcMsg{
		Family:  nl.FAMILY_ALL,
		Ifindex: int32(base.LinkIndex),
		Handle:  base.Handle,
		Parent:  base.Parent,
		Info:    MakeHandle(base.Priority, nl.Swap16(base.Protocol)),
	}
	req.AddData(msg)
	req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(filter.Type())))

	options := nl.NewRtAttr(nl.TCA_OPTIONS, nil)
	if u32, ok := filter.(*U32); ok {
		// match all
		sel := nl.TcU32Sel{
			Nkeys: 1,
			Flags: nl.TC_U32_TERMINAL,
		}
		sel.Keys = append(sel.Keys, nl.TcU32Key{})
		nl.NewRtAttrChild(options, nl.TCA_U32_SEL, sel.Serialize())
		actions := nl.NewRtAttrChild(options, nl.TCA_U32_ACT, nil)
		table := nl.NewRtAttrChild(actions, nl.TCA_ACT_TAB, nil)
		nl.NewRtAttrChild(table, nl.TCA_KIND, nl.ZeroTerminated("mirred"))
		// redirect to other interface
		mir := nl.TcMirred{
			Action:  nl.TC_ACT_STOLEN,
			Eaction: nl.TCA_EGRESS_REDIR,
			Ifindex: uint32(u32.RedirIndex),
		}
		aopts := nl.NewRtAttrChild(table, nl.TCA_OPTIONS, nil)
		nl.NewRtAttrChild(aopts, nl.TCA_MIRRED_PARMS, mir.Serialize())
	}
	req.AddData(options)
	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}

// LinkSetName sets the name of the link device.
// Equivalent to: `ip link set $link name $name`
func LinkSetName(link Link, name string) error {
	base := link.Attrs()
	ensureIndex(base)
	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	msg.Index = int32(base.Index)
	req.AddData(msg)

	data := nl.NewRtAttr(syscall.IFLA_IFNAME, []byte(name))
	req.AddData(data)

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

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
}

// LinkSetHardwareAddr sets the hardware address of the link device.
// Equivalent to: `ip link set $link address $hwaddr`
func LinkSetHardwareAddr(link Link, hwaddr net.HardwareAddr) error {
	base := link.Attrs()
	ensureIndex(base)
	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	msg.Index = int32(base.Index)
	req.AddData(msg)

	data := nl.NewRtAttr(syscall.IFLA_ADDRESS, []byte(hwaddr))
	req.AddData(data)

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

// LinkSetMTU sets the mtu of the link device.
// Equivalent to: `ip link set $link mtu $mtu`
func LinkSetMTU(link Link, mtu int) error {
	base := link.Attrs()
	ensureIndex(base)
	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	msg.Index = int32(base.Index)
	req.AddData(msg)

	b := make([]byte, 4)
	native.PutUint32(b, uint32(mtu))

	data := nl.NewRtAttr(syscall.IFLA_MTU, b)
	req.AddData(data)

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

func setProtinfoAttr(link Link, mode bool, attr int) error {
	base := link.Attrs()
	ensureIndex(base)
	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_BRIDGE)
	msg.Index = int32(base.Index)
	req.AddData(msg)

	br := nl.NewRtAttr(syscall.IFLA_PROTINFO|syscall.NLA_F_NESTED, nil)
	nl.NewRtAttrChild(br, attr, boolToByte(mode))
	req.AddData(br)
	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	if err != nil {
		return err
	}
	return nil
}

// 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
}

// LinkSetNsPid puts the device into a new network namespace. The
// fd must be an open file descriptor to a network namespace.
// Similar to: `ip link set $link netns $ns`
func LinkSetNsFd(link Link, fd int) error {
	base := link.Attrs()
	ensureIndex(base)
	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	msg.Type = syscall.RTM_SETLINK
	msg.Flags = syscall.NLM_F_REQUEST
	msg.Index = int32(base.Index)
	msg.Change = nl.DEFAULT_CHANGE
	req.AddData(msg)

	b := make([]byte, 4)
	native.PutUint32(b, uint32(fd))

	data := nl.NewRtAttr(nl.IFLA_NET_NS_FD, b)
	req.AddData(data)

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

// LinkByName finds a link by name and returns a pointer to the object.
func LinkByName(name string) (Link, error) {
	if lookupByDump {
		return linkByNameDump(name)
	}

	req := nl.NewNetlinkRequest(syscall.RTM_GETLINK, syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	req.AddData(msg)

	nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(name))
	req.AddData(nameData)

	link, err := execGetLink(req)
	if err == syscall.EINVAL {
		// older kernels don't support looking up via IFLA_IFNAME
		// so fall back to dumping all links
		lookupByDump = true
		return linkByNameDump(name)
	}

	return link, err
}

// 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
	}

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

}

// LinkAdd adds a new link device. The type and features of the device
// are taken fromt the parameters in the link object.
// Equivalent to: `ip link add $link`
func LinkAdd(link Link) error {
	// TODO: set mtu and hardware address
	// TODO: support extra data for macvlan
	base := link.Attrs()

	if base.Name == "" {
		return fmt.Errorf("LinkAttrs.Name cannot be empty!")
	}

	req := nl.NewNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)

	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
	req.AddData(msg)

	if base.ParentIndex != 0 {
		b := make([]byte, 4)
		native.PutUint32(b, uint32(base.ParentIndex))
		data := nl.NewRtAttr(syscall.IFLA_LINK, b)
		req.AddData(data)
	} else if link.Type() == "ipvlan" {
		return fmt.Errorf("Can't create ipvlan link without ParentIndex")
	}

	nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(base.Name))
	req.AddData(nameData)

	if base.MTU > 0 {
		mtu := nl.NewRtAttr(syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU)))
		req.AddData(mtu)
	}

	if base.TxQLen >= 0 {
		qlen := nl.NewRtAttr(syscall.IFLA_TXQLEN, nl.Uint32Attr(uint32(base.TxQLen)))
		req.AddData(qlen)
	}

	if base.Namespace != nil {
		var attr *nl.RtAttr
		switch base.Namespace.(type) {
		case NsPid:
			val := nl.Uint32Attr(uint32(base.Namespace.(NsPid)))
			attr = nl.NewRtAttr(syscall.IFLA_NET_NS_PID, val)
		case NsFd:
			val := nl.Uint32Attr(uint32(base.Namespace.(NsFd)))
			attr = nl.NewRtAttr(nl.IFLA_NET_NS_FD, val)
		}

		req.AddData(attr)
	}

	linkInfo := nl.NewRtAttr(syscall.IFLA_LINKINFO, nil)
	nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_KIND, nl.NonZeroTerminated(link.Type()))

	if vlan, ok := link.(*Vlan); ok {
		b := make([]byte, 2)
		native.PutUint16(b, uint16(vlan.VlanId))
		data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil)
		nl.NewRtAttrChild(data, nl.IFLA_VLAN_ID, b)
	} else if veth, ok := link.(*Veth); ok {
		data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil)
		peer := nl.NewRtAttrChild(data, nl.VETH_INFO_PEER, nil)
		nl.NewIfInfomsgChild(peer, syscall.AF_UNSPEC)
		nl.NewRtAttrChild(peer, syscall.IFLA_IFNAME, nl.ZeroTerminated(veth.PeerName))
		if base.TxQLen >= 0 {
			nl.NewRtAttrChild(peer, syscall.IFLA_TXQLEN, nl.Uint32Attr(uint32(base.TxQLen)))
		}
		if base.MTU > 0 {
			nl.NewRtAttrChild(peer, syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU)))
		}

	} else if vxlan, ok := link.(*Vxlan); ok {
		addVxlanAttrs(vxlan, linkInfo)
	} else if ipv, ok := link.(*IPVlan); ok {
		data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil)
		nl.NewRtAttrChild(data, nl.IFLA_IPVLAN_MODE, nl.Uint16Attr(uint16(ipv.Mode)))
	} else if macv, ok := link.(*Macvlan); ok {
		if macv.Mode != MACVLAN_MODE_DEFAULT {
			data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil)
			nl.NewRtAttrChild(data, nl.IFLA_MACVLAN_MODE, nl.Uint32Attr(macvlanModes[macv.Mode]))
		}
	}

	req.AddData(linkInfo)

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	if err != nil {
		return err
	}

	ensureIndex(base)

	// can't set master during create, so set it afterwards
	if base.MasterIndex != 0 {
		// TODO: verify MasterIndex is actually a bridge?
		return LinkSetMasterByIndex(link, base.MasterIndex)
	}
	return nil
//.........这里部分代码省略.........

func routeHandle(route *Route, req *nl.NetlinkRequest) 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 := nl.NewRtMsg()
	msg.Scope = uint8(route.Scope)
	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
}