// ConfigureIface takes the result of IPAM plugin and
// applies to the ifName interface
func ConfigureIface(ifName string, res *types.Result) error {
link, err := netlink.LinkByName(ifName)
if err != nil {
return fmt.Errorf("failed to lookup %q: %v", ifName, err)
}
if err := netlink.LinkSetUp(link); err != nil {
return fmt.Errorf("failed to set %q UP: %v", ifName, err)
}
// TODO(eyakubovich): IPv6
addr := &netlink.Addr{IPNet: &res.IP4.IP, Label: ""}
if err = netlink.AddrAdd(link, addr); err != nil {
return fmt.Errorf("failed to add IP addr to %q: %v", ifName, err)
}
for _, r := range res.IP4.Routes {
gw := r.GW
if gw == nil {
gw = res.IP4.Gateway
}
if err = ip.AddRoute(&r.Dst, gw, link); err != nil {
// we skip over duplicate routes as we assume the first one wins
if !os.IsExist(err) {
return fmt.Errorf("failed to add route '%v via %v dev %v': %v", r.Dst, gw, ifName, err)
}
}
}
return nil
}
// DoNetworking performs the networking for the given config and IPAM result
func DoNetworking(args *skel.CmdArgs, conf NetConf, res *types.Result, logger *log.Entry, desiredVethName string) (hostVethName, contVethMAC string, err error) {
// Select the first 11 characters of the containerID for the host veth.
hostVethName = "cali" + args.ContainerID[:min(11, len(args.ContainerID))]
contVethName := args.IfName
// If a desired veth name was passed in, use that instead.
if desiredVethName != "" {
hostVethName = desiredVethName
}
err = ns.WithNetNSPath(args.Netns, func(hostNS ns.NetNS) error {
veth := &netlink.Veth{
LinkAttrs: netlink.LinkAttrs{
Name: contVethName,
Flags: net.FlagUp,
MTU: conf.MTU,
},
PeerName: hostVethName,
}
if err := netlink.LinkAdd(veth); err != nil {
logger.Errorf("Error adding veth %+v: %s", veth, err)
return err
}
hostVeth, err := netlink.LinkByName(hostVethName)
if err != nil {
err = fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
return err
}
contVeth, err := netlink.LinkByName(contVethName)
if err != nil {
err = fmt.Errorf("failed to lookup %q: %v", contVethName, err)
return err
}
// Fetch the MAC from the container Veth. This is needed by Calico.
contVethMAC = contVeth.Attrs().HardwareAddr.String()
logger.WithField("MAC", contVethMAC).Debug("Found MAC for container veth")
// At this point, the virtual ethernet pair has been created, and both ends have the right names.
// Both ends of the veth are still in the container's network namespace.
// Before returning, create the routes inside the namespace, first for IPv4 then IPv6.
if res.IP4 != nil {
// Add a connected route to a dummy next hop so that a default route can be set
gw := net.IPv4(169, 254, 1, 1)
gwNet := &net.IPNet{IP: gw, Mask: net.CIDRMask(32, 32)}
if err = netlink.RouteAdd(&netlink.Route{
LinkIndex: contVeth.Attrs().Index,
Scope: netlink.SCOPE_LINK,
Dst: gwNet}); err != nil {
return fmt.Errorf("failed to add route %v", err)
}
if err = ip.AddDefaultRoute(gw, contVeth); err != nil {
return fmt.Errorf("failed to add route %v", err)
}
if err = netlink.AddrAdd(contVeth, &netlink.Addr{IPNet: &res.IP4.IP}); err != nil {
return fmt.Errorf("failed to add IP addr to %q: %v", contVethName, err)
}
}
// Handle IPv6 routes
if res.IP6 != nil {
// No need to add a dummy next hop route as the host veth device will already have an IPv6
// link local address that can be used as a next hop.
// Just fetch the address of the host end of the veth and use it as the next hop.
var hostIPv6Addr net.IP
if err := hostNS.Do(func(_ ns.NetNS) error {
addresses, err := netlink.AddrList(hostVeth, netlink.FAMILY_V6)
if err != nil {
logger.Errorf("Error listing IPv6 addresses: %s", err)
return err
}
if len(addresses) < 1 {
// If the hostVeth doesn't have an IPv6 address then this host probably doesn't
// support IPv6. Since a IPv6 address has been allocated that can't be used,
// return an error.
return fmt.Errorf("Failed to get IPv6 addresses for container veth")
}
hostIPv6Addr = addresses[0].IP
return nil
}); err != nil {
logger.Errorf("Error getting IPv6 address: %s", err)
return err
}
_, defNet, _ := net.ParseCIDR("::/0")
if err = ip.AddRoute(defNet, hostIPv6Addr, contVeth); err != nil {
return fmt.Errorf("failed to add default gateway to %v %v", hostIPv6Addr, err)
}
if err = netlink.AddrAdd(contVeth, &netlink.Addr{IPNet: &res.IP6.IP}); err != nil {
return fmt.Errorf("failed to add IP addr to %q: %v", contVeth, err)
}
}
// Now that the everything has been successfully set up in the container, move the "host" end of the
// veth into the host namespace.
if err = netlink.LinkSetNsFd(hostVeth, int(hostNS.Fd())); err != nil {
return fmt.Errorf("failed to move veth to host netns: %v", err)
}
return nil
})
if err != nil {
logger.Errorf("Error creating veth: %s", err)
return "", "", err
}
// Moving a veth between namespaces always leaves it in the "DOWN" state. Set it back to "UP" now that we're
// back in the host namespace.
hostVeth, err := netlink.LinkByName(hostVethName)
if err != nil {
return "", "", fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
}
if err = netlink.LinkSetUp(hostVeth); err != nil {
return "", "", fmt.Errorf("failed to set %q up: %v", hostVethName, err)
}
return hostVethName, contVethMAC, err
}