diff --git a/ipam/ipam.go b/ipam/ipam.go index d9fbff74..7777e6f6 100644 --- a/ipam/ipam.go +++ b/ipam/ipam.go @@ -23,6 +23,17 @@ import ( "github.com/containernetworking/cni/pkg/types" "github.com/vishvananda/netlink" + "net" + "strconv" + "strings" +) + +const ( + // private mac prefix safe to use + privateMACPrefix = "0a:58" + + // veth link dev type + vethLinkType = "veth" ) func ExecAdd(plugin string, netconf []byte) (*types.Result, error) { @@ -45,6 +56,17 @@ func ConfigureIface(ifName string, res *types.Result) error { return fmt.Errorf("failed to set %q UP: %v", ifName, err) } + // only set hardware address to veth when using ipv4 + if link.Type() == vethLinkType && res.IP4 != nil { + hwAddr, err := generateHardwareAddr(res.IP4.IP.IP) + if err != nil { + return fmt.Errorf("failed to generate hardware addr: %v", err) + } + if err = netlink.LinkSetHardwareAddr(link, hwAddr); err != nil { + return fmt.Errorf("failed to add hardware addr to %q: %v", ifName, err) + } + } + // TODO(eyakubovich): IPv6 addr := &netlink.Addr{IPNet: &res.IP4.IP, Label: ""} if err = netlink.AddrAdd(link, addr); err != nil { @@ -66,3 +88,21 @@ func ConfigureIface(ifName string, res *types.Result) error { return nil } + +// generateHardwareAddr generates 48 bit virtual mac addresses based on the IP input. +func generateHardwareAddr(ip net.IP) (net.HardwareAddr, error) { + if ip.To4() == nil { + return nil, fmt.Errorf("generateHardwareAddr only support valid ipv4 address as input") + } + mac := privateMACPrefix + sections := strings.Split(ip.String(), ".") + for _, s := range sections { + i, _ := strconv.Atoi(s) + mac = mac + ":" + fmt.Sprintf("%02x", i) + } + hwAddr, err := net.ParseMAC(mac) + if err != nil { + return nil, fmt.Errorf("Failed to parse mac address %s generated based on ip %s due to: %v", mac, ip, err) + } + return hwAddr, nil +}