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: gtp_linux.go
    path of file: ./repos/sliver/vendor/github.com/tailscale/netlink
    
    the code of the file until where you have to start completion: package netlink

import (
	"fmt"
	"net"
	"strings"
	"syscall"

	"github.com/vishvananda/netlink/nl"
	"golang.org/x/sys/unix"
)

type PDP struct {
	Version     uint32
	TID         uint64
	PeerAddress net.IP
	MSAddress   net.IP
	Flow        uint16
	NetNSFD     uint32
	ITEI        uint32
	OTEI        uint32
}

func (pdp *PDP) String() string {
	elems := []string{}
	elems = append(elems, fmt.Sprintf("Version: %d", pdp.Version))
	if pdp.Version == 0 {
		elems = append(elems, fmt.Sprintf("TID: %d", pdp.TID))
	} else if pdp.Version == 1 {
		elems = append(elems, fmt.Sprintf("TEI: %d/%d", pdp.ITEI, pdp.OTEI))
	}
	elems = append(elems, fmt.Sprintf("MS-Address: %s", pdp.MSAddress))
	elems = append(elems, fmt.Sprintf("Peer-Address: %s", pdp.PeerAddress))
	return fmt.Sprintf("{%s}", strings.Join(elems, " "))
}

func (p *PDP) parseAttributes(attrs []syscall.NetlinkRouteAttr) error {
	for _, a := range attrs {
		switch a.Attr.Type
    
func (h *Handle) GTPPDPAdd(link Link, pdp *PDP) error {
	f, err := h.GenlFamilyGet(nl.GENL_GTP_NAME)
	if err != nil {
		return err
	}
	msg := &nl.Genlmsg{
		Command: nl.GENL_GTP_CMD_NEWPDP,
		Version: nl.GENL_GTP_VERSION,
	}
	req := h.newNetlinkRequest(int(f.ID), unix.NLM_F_EXCL|unix.NLM_F_ACK)
	req.AddData(msg)
	req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_VERSION, nl.Uint32Attr(pdp.Version)))
	req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_LINK, nl.Uint32Attr(uint32(link.Attrs().Index))))
	req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_PEER_ADDRESS, []byte(pdp.PeerAddress.To4())))
	req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_MS_ADDRESS, []byte(pdp.MSAddress.To4())))

	switch pdp.Version {
	case 0:
		req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_TID, nl.Uint64Attr(pdp.TID)))
		req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_FLOW, nl.Uint16Attr(pdp.Flow)))
	case 1:
		req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_I_TEI, nl.Uint32Attr(pdp.ITEI)))
		req.AddData(nl.NewRtAttr(nl.GENL_GTP_ATTR_O_TEI, nl.Uint32Attr(pdp.OTEI)))
	default:
		return fmt.Errorf("unsupported GTP version: %d", pdp.Version)
	}
	_, err = req.Execute(unix.NETLINK_GENERIC, 0)
	return err
}