func cmdAdd(args *skel.CmdArgs) error {
n, err := loadConf(args.StdinData)
if err != nil {
return err
}
netns, err := os.Open(args.Netns)
if err != nil {
return fmt.Errorf("failed to open netns %q: %v", netns, err)
}
defer netns.Close()
tmpName, err := ip.RandomVethName()
if err != nil {
return err
}
if err = createIpvlan(n, tmpName, netns); err != nil {
return err
}
// run the IPAM plugin and get back the config to apply
result, err := plugin.ExecAdd(n.IPAM.Type, args.StdinData)
if err != nil {
return err
}
if result.IP4 == nil {
return errors.New("IPAM plugin returned missing IPv4 config")
}
err = ns.WithNetNS(netns, func(_ *os.File) error {
err := renameLink(tmpName, args.IfName)
if err != nil {
return fmt.Errorf("failed to rename ipvlan to %q: %v", args.IfName, err)
}
return plugin.ConfigureIface(args.IfName, result)
})
if err != nil {
return err
}
if n.IPMasq {
chain := "CNI-" + n.Name
if err = ip.SetupIPMasq(ip.Network(&result.IP4.IP), chain); err != nil {
return err
}
}
return plugin.PrintResult(result)
}
func createMacvlan(conf *NetConf, ifName string, netns *os.File) error {
mode, err := modeFromString(conf.Mode)
if err != nil {
return err
}
m, err := netlink.LinkByName(conf.Master)
if err != nil {
return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
}
// due to kernel bug we have to create with tmpname or it might
// collide with the name on the host and error out
tmpName, err := ip.RandomVethName()
if err != nil {
return err
}
mv := &netlink.Macvlan{
LinkAttrs: netlink.LinkAttrs{
MTU: conf.MTU,
Name: tmpName,
ParentIndex: m.Attrs().Index,
Namespace: netlink.NsFd(int(netns.Fd())),
},
Mode: mode,
}
if err := netlink.LinkAdd(mv); err != nil {
return fmt.Errorf("failed to create macvlan: %v", err)
}
return ns.WithNetNS(netns, false, func(_ *os.File) error {
err := renameLink(tmpName, ifName)
if err != nil {
return fmt.Errorf("failed to rename macvlan to %q: %v", ifName, err)
}
return nil
})
}