// setupTapDevice creates persistent macvtap device
// and returns a newly created netlink.Link structure
// using part of pod hash and interface number in interface name
func setupMacVTapDevice(podID types.UUID, config MacVTapNetConf, interfaceNumber int) (netlink.Link, error) {
master, err := netlink.LinkByName(config.Master)
if err != nil {
return nil, errwrap.Wrap(fmt.Errorf("cannot find master device '%v'", config.Master), err)
}
var mode netlink.MacvlanMode
switch config.Mode {
// if not set - defaults to bridge mode as in:
// https://github.com/coreos/rkt/blob/master/Documentation/networking.md#macvlan
case "", "bridge":
mode = netlink.MACVLAN_MODE_BRIDGE
case "private":
mode = netlink.MACVLAN_MODE_PRIVATE
case "vepa":
mode = netlink.MACVLAN_MODE_VEPA
case "passthru":
mode = netlink.MACVLAN_MODE_PASSTHRU
default:
return nil, fmt.Errorf("unsupported macvtap mode: %v", config.Mode)
}
mtu := master.Attrs().MTU
if config.MTU != 0 {
mtu = config.MTU
}
interfaceName := fmt.Sprintf("rkt-%s-vtap%d", podID.String()[0:4], interfaceNumber)
link := &netlink.Macvtap{
Macvlan: netlink.Macvlan{
LinkAttrs: netlink.LinkAttrs{
Name: interfaceName,
MTU: mtu,
ParentIndex: master.Attrs().Index,
},
Mode: mode,
},
}
if err := netlink.LinkAdd(link); err != nil {
return nil, errwrap.Wrap(errors.New("cannot create macvtap interface"), err)
}
// TODO: duplicate following lines for ipv6 support, when it will be added in other places
ipv4SysctlValueName := fmt.Sprintf(IPv4InterfaceArpProxySysctlTemplate, interfaceName)
if _, err := cnisysctl.Sysctl(ipv4SysctlValueName, "1"); err != nil {
// remove the newly added link and ignore errors, because we already are in a failed state
_ = netlink.LinkDel(link)
return nil, errwrap.Wrap(fmt.Errorf("failed to set proxy_arp on newly added interface %q", interfaceName), err)
}
if err := netlink.LinkSetUp(link); err != nil {
// remove the newly added link and ignore errors, because we already are in a failed state
_ = netlink.LinkDel(link)
return nil, errwrap.Wrap(errors.New("cannot set up macvtap interface"), err)
}
return link, nil
}
func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) 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 netns.Do(func(_ ns.NetNS) error {
// TODO: duplicate following lines for ipv6 support, when it will be added in other places
ipv4SysctlValueName := fmt.Sprintf(IPv4InterfaceArpProxySysctlTemplate, tmpName)
if _, err := sysctl.Sysctl(ipv4SysctlValueName, "1"); err != nil {
// remove the newly added link and ignore errors, because we already are in a failed state
_ = netlink.LinkDel(mv)
return fmt.Errorf("failed to set proxy_arp on newly added interface %q: %v", tmpName, err)
}
err := renameLink(tmpName, ifName)
if err != nil {
_ = netlink.LinkDel(mv)
return fmt.Errorf("failed to rename macvlan to %q: %v", ifName, err)
}
return nil
})
}