From b6137de9930a6519dae4c5100afabdc6d4374676 Mon Sep 17 00:00:00 2001 From: Stefan Junker Date: Tue, 28 Jun 2016 17:46:17 -0700 Subject: [PATCH] plugins: set MAC addresses based on IP 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 --- ip/link.go | 17 +++++++++++++++++ ipam/ipam.go | 17 ----------------- utils/hwaddr/hwaddr.go | 31 +++++++++++++------------------ utils/hwaddr/hwaddr_test.go | 12 ++++++------ 4 files changed, 36 insertions(+), 41 deletions(-) diff --git a/ip/link.go b/ip/link.go index 1b785672..6d9d1cc2 100644 --- a/ip/link.go +++ b/ip/link.go @@ -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 +} diff --git a/ipam/ipam.go b/ipam/ipam.go index 62bf15d5..d9fbff74 100644 --- a/ipam/ipam.go +++ b/ipam/ipam.go @@ -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 { diff --git a/utils/hwaddr/hwaddr.go b/utils/hwaddr/hwaddr.go index f03b7aca..aaf3b8a0 100644 --- a/utils/hwaddr/hwaddr.go +++ b/utils/hwaddr/hwaddr.go @@ -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 } diff --git a/utils/hwaddr/hwaddr_test.go b/utils/hwaddr/hwaddr_test.go index 8a201a25..51c4e498 100644 --- a/utils/hwaddr/hwaddr_test.go +++ b/utils/hwaddr/hwaddr_test.go @@ -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{})) }) })