ok

utils/addDev.go

@@ -0,0 +1,67 @@
+/*
+Copyright © 2026 Masato Kikuchi <m-kikuchi@neody.ad.jp>
+*/
+
+package utils
+
+import (
+	"encoding/binary"
+	"net"
+
+	"github.com/vishvananda/netlink"
+	"github.com/vishvananda/netlink/nl"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	IFLA_ETHERIP6_UNSPEC = iota
+	IFLA_ETHERIP6_LOCAL
+	IFLA_ETHERIP6_REMOTE
+	IFLA_ETHERIP6_LINK
+	IFLA_ETHERIP6_HOP_LIMIT
+)
+
+func u32(v uint32) []byte {
+	b := make([]byte, 4)
+	binary.NativeEndian.PutUint32(b, v)
+	return b
+}
+
+func AddDev(DevName string, local net.IP, remote net.IP, linkName string) error {
+	req := nl.NewNetlinkRequest(
+		unix.RTM_NEWLINK,
+		unix.NLM_F_REQUEST|unix.NLM_F_CREATE|unix.NLM_F_EXCL|unix.NLM_F_ACK,
+	)
+
+	msg := nl.NewIfInfomsg(unix.AF_UNSPEC)
+	req.AddData(msg)
+
+	req.AddData(nl.NewRtAttr(unix.IFLA_IFNAME, []byte(DevName)))
+
+	linkInfo := nl.NewRtAttr(unix.IFLA_LINKINFO, nil)
+	linkInfo.AddRtAttr(nl.IFLA_INFO_KIND, nl.ZeroTerminated("etherip6"))
+
+	infoData := nl.NewRtAttr(nl.IFLA_INFO_DATA, nil)
+	infoData.AddRtAttr(IFLA_ETHERIP6_LOCAL, local.To16())
+	infoData.AddRtAttr(IFLA_ETHERIP6_REMOTE, remote.To16())
+
+	if linkName != "" {
+		link, err := netlink.LinkByName(linkName)
+		if err != nil {
+			return err
+		}
+		infoData.AddRtAttr(IFLA_ETHERIP6_LINK, u32(uint32(link.Attrs().Index)))
+	}
+
+	infoData.AddRtAttr(IFLA_ETHERIP6_HOP_LIMIT, []byte{255})
+
+	linkInfo.AddRtAttr(nl.IFLA_INFO_DATA, infoData.Serialize())
+	req.AddData(linkInfo)
+
+	_, err := req.Execute(unix.NETLINK_ROUTE, 0)
+
+	if err != nil {
+		return err
+	}
+	return nil
+}