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plugins: set MAC addresses based on IP

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This will give deterministic MAC addresses for all interfaces CNI
creates and manages the IP for:
* bridge: container veth and host bridge
* macvlan: container veth
* ptp: container veth and host veth
This commit is contained in:
Stefan Junker 2016-06-28 17:46:17 -07:00
parent c3e8563e77
commit b6137de993
4 changed files with 36 additions and 41 deletions
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17
ip/link.go
View File

@ -21,6 +21,7 @@ import (
"os"
"github.com/containernetworking/cni/pkg/ns"
"github.com/containernetworking/cni/pkg/utils/hwaddr"
"github.com/vishvananda/netlink"
)
@ -151,3 +152,19 @@ func DelLinkByNameAddr(ifName string, family int) (*net.IPNet, error) {
return addrs[0].IPNet, nil
}
func SetHWAddrByIP(link netlink.Link, ip4 net.IP, ip6 net.IP) error {
if ip4 != nil {
hwAddr, err := hwaddr.GenerateHardwareAddr4(ip4, hwaddr.PrivateMACPrefix)
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", link.Attrs().Name, err)
}
}
// TODO: IPv6
return nil
}

17
ipam/ipam.go
View File

@ -21,16 +21,10 @@ import (
"github.com/containernetworking/cni/pkg/invoke"
"github.com/containernetworking/cni/pkg/ip"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/utils/hwaddr"
"github.com/vishvananda/netlink"
)
const (
// veth link dev type
vethLinkType = "veth"
)
func ExecAdd(plugin string, netconf []byte) (*types.Result, error) {
return invoke.DelegateAdd(plugin, netconf)
}
@ -51,17 +45,6 @@ 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 := hwaddr.GenerateHardwareAddr4(res.IP4.IP.IP, hwaddr.PrivateMACPrefix)
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 {

31
utils/hwaddr/hwaddr.go
View File

@ -17,13 +17,16 @@ package hwaddr
import (
"fmt"
"net"
"strconv"
"strings"
)
const (
ipRelevantByteLen = 4
PrivateMACPrefixString = "0a:58"
)
var (
// private mac prefix safe to use
PrivateMACPrefix = "0a:58"
PrivateMACPrefix = []byte{0x0a, 0x58}
)
type SupportIp4OnlyErr struct{ msg string }
@ -39,7 +42,7 @@ type InvalidPrefixLengthErr struct{ msg string }
func (e InvalidPrefixLengthErr) Error() string { return e.msg }
// GenerateHardwareAddr4 generates 48 bit virtual mac addresses based on the IP4 input.
func GenerateHardwareAddr4(ip net.IP, prefix string) (net.HardwareAddr, error) {
func GenerateHardwareAddr4(ip net.IP, prefix []byte) (net.HardwareAddr, error) {
switch {
case ip.To4() == nil:
@ -51,18 +54,10 @@ func GenerateHardwareAddr4(ip net.IP, prefix string) (net.HardwareAddr, error) {
}
}
mac := prefix
sections := strings.Split(ip.String(), ".")
for _, s := range sections {
i, _ := strconv.Atoi(s)
mac += fmt.Sprintf(":%02x", i)
}
hwAddr, err := net.ParseMAC(mac)
if err != nil {
return nil, MacParseErr{msg: fmt.Sprintf(
"Failed to parse mac address %q generated based on IP %q due to: %v", mac, ip, err),
}
}
return hwAddr, nil
ipByteLen := len(ip)
return (net.HardwareAddr)(
append(
prefix,
ip[ipByteLen-ipRelevantByteLen:ipByteLen]...),
), nil
}

12
utils/hwaddr/hwaddr_test.go
View File

@ -28,26 +28,26 @@ var _ = Describe("Hwaddr", func() {
It("generate hardware address based on ipv4 address", func() {
testCases := []struct {
ip net.IP
expectedMAC string
expectedMAC net.HardwareAddr
}{
{
ip: net.ParseIP("10.0.0.2"),
expectedMAC: hwaddr.PrivateMACPrefix + ":0a:00:00:02",
expectedMAC: (net.HardwareAddr)(append(hwaddr.PrivateMACPrefix, 0x0a, 0x00, 0x00, 0x02)),
},
{
ip: net.ParseIP("10.250.0.244"),
expectedMAC: hwaddr.PrivateMACPrefix + ":0a:fa:00:f4",
expectedMAC: (net.HardwareAddr)(append(hwaddr.PrivateMACPrefix, 0x0a, 0xfa, 0x00, 0xf4)),
},
{
ip: net.ParseIP("172.17.0.2"),
expectedMAC: hwaddr.PrivateMACPrefix + ":ac:11:00:02",
expectedMAC: (net.HardwareAddr)(append(hwaddr.PrivateMACPrefix, 0xac, 0x11, 0x00, 0x02)),
},
}
for _, tc := range testCases {
mac, err := hwaddr.GenerateHardwareAddr4(tc.ip, hwaddr.PrivateMACPrefix)
Expect(err).NotTo(HaveOccurred())
Expect(mac.String()).To(Equal(tc.expectedMAC))
Expect(mac).To(Equal(tc.expectedMAC))
}
})
@ -63,7 +63,7 @@ var _ = Describe("Hwaddr", func() {
})
It("return error if prefix is invalid", func() {
_, err := hwaddr.GenerateHardwareAddr4(net.ParseIP("10.0.0.2"), "")
_, err := hwaddr.GenerateHardwareAddr4(net.ParseIP("10.0.0.2"), []byte{0x58})
Expect(err).To(BeAssignableToTypeOf(hwaddr.InvalidPrefixLengthErr{}))
})
})