Merge pull request #781 from mmirecki/vlan_incontainermaster

Add support for in-container master for vlans

plugins/main/vlan/vlan.go

@@ -20,12 +20,11 @@ import (
 	"fmt"
 	"runtime"
 
-	"github.com/vishvananda/netlink"
-
 	"github.com/containernetworking/cni/pkg/skel"
 	"github.com/containernetworking/cni/pkg/types"
 	current "github.com/containernetworking/cni/pkg/types/100"
 	"github.com/containernetworking/cni/pkg/version"
+	"github.com/vishvananda/netlink"
 
 	"github.com/containernetworking/plugins/pkg/ip"
 	"github.com/containernetworking/plugins/pkg/ipam"
@@ -38,6 +37,7 @@ type NetConf struct {
 	Master     string `json:"master"`
 	VlanId     int    `json:"vlanId"`
 	MTU        int    `json:"mtu,omitempty"`
+	LinkContNs bool   `json:"linkInContainer,omitempty"`
 }
 
 func init() {
@@ -47,9 +47,9 @@ func init() {
 	runtime.LockOSThread()
 }
 
-func loadConf(bytes []byte) (*NetConf, string, error) {
+func loadConf(args *skel.CmdArgs) (*NetConf, string, error) {
 	n := &NetConf{}
-	if err := json.Unmarshal(bytes, n); err != nil {
+	if err := json.Unmarshal(args.StdinData, n); err != nil {
 		return nil, "", fmt.Errorf("failed to load netconf: %v", err)
 	}
 	if n.Master == "" {
@@ -60,19 +60,34 @@ func loadConf(bytes []byte) (*NetConf, string, error) {
 	}
 
 	// check existing and MTU of master interface
-	masterMTU, err := getMTUByName(n.Master)
+	masterMTU, err := getMTUByName(n.Master, args.Netns, n.LinkContNs)
+
 	if err != nil {
 		return nil, "", err
 	}
 	if n.MTU < 0 || n.MTU > masterMTU {
 		return nil, "", fmt.Errorf("invalid MTU %d, must be [0, master MTU(%d)]", n.MTU, masterMTU)
 	}
-
 	return n, n.CNIVersion, nil
 }
 
-func getMTUByName(ifName string) (int, error) {
+func getMTUByName(ifName string, namespace string, inContainer bool) (int, error) {
-	link, err := netlink.LinkByName(ifName)
+	var link netlink.Link
+	var err error
+	if inContainer {
+		netns, err := ns.GetNS(namespace)
+		if err != nil {
+			return 0, fmt.Errorf("failed to open netns %q: %v", netns, err)
+		}
+		defer netns.Close()
+
+		err = netns.Do(func(_ ns.NetNS) error {
+			link, err = netlink.LinkByName(ifName)
+			return err
+		})
+	} else {
+		link, err = netlink.LinkByName(ifName)
+	}
 	if err != nil {
 		return 0, err
 	}
@@ -82,7 +97,17 @@ func getMTUByName(ifName string) (int, error) {
 func createVlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Interface, error) {
 	vlan := &current.Interface{}
 
-	m, err := netlink.LinkByName(conf.Master)
+	var m netlink.Link
+	var err error
+	if conf.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			m, err = netlink.LinkByName(conf.Master)
+			return err
+		})
+	} else {
+		m, err = netlink.LinkByName(conf.Master)
+	}
+
 	if err != nil {
 		return nil, fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
 	}
@@ -104,7 +129,14 @@ func createVlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Interfac
 		VlanId: conf.VlanId,
 	}
 
-	if err := netlink.LinkAdd(v); err != nil {
+	if conf.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			return netlink.LinkAdd(v)
+		})
+	} else {
+		err = netlink.LinkAdd(v)
+	}
+	if err != nil {
 		return nil, fmt.Errorf("failed to create vlan: %v", err)
 	}
 
@@ -133,7 +165,7 @@ func createVlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Interfac
 }
 
 func cmdAdd(args *skel.CmdArgs) error {
-	n, cniVersion, err := loadConf(args.StdinData)
+	n, cniVersion, err := loadConf(args)
 	if err != nil {
 		return err
 	}
@@ -191,7 +223,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 }
 
 func cmdDel(args *skel.CmdArgs) error {
-	n, _, err := loadConf(args.StdinData)
+	n, _, err := loadConf(args)
 	if err != nil {
 		return err
 	}
@@ -276,8 +308,16 @@ func cmdCheck(args *skel.CmdArgs) error {
 		return fmt.Errorf("Sandbox in prevResult %s doesn't match configured netns: %s",
 			contMap.Sandbox, args.Netns)
 	}
+	var m netlink.Link
+	if conf.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			m, err = netlink.LinkByName(conf.Master)
+			return err
+		})
+	} else {
+		m, err = netlink.LinkByName(conf.Master)
+	}
 
-	m, err := netlink.LinkByName(conf.Master)
 	if err != nil {
 		return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
 	}

plugins/main/vlan/vlan_test.go

@@ -38,6 +38,7 @@ import (
 )
 
 const MASTER_NAME = "eth0"
+const MASTER_NAME_INCONTAINER = "eth1"
 
 type Net struct {
 	Name          string                 `json:"name"`
@@ -50,6 +51,7 @@ type Net struct {
 	DNS           types.DNS              `json:"dns"`
 	RawPrevResult map[string]interface{} `json:"prevResult,omitempty"`
 	PrevResult    types100.Result        `json:"-"`
+	LinkContNs    bool                   `json:"linkInContainer"`
 }
 
 func buildOneConfig(netName string, cniVersion string, orig *Net, prevResult types.Result) (*Net, error) {
@@ -197,6 +199,24 @@ var _ = Describe("vlan Operations", func() {
 			return nil
 		})
 		Expect(err).NotTo(HaveOccurred())
+
+		err = targetNS.Do(func(ns.NetNS) error {
+			defer GinkgoRecover()
+
+			// Add master
+			err = netlink.LinkAdd(&netlink.Dummy{
+				LinkAttrs: netlink.LinkAttrs{
+					Name: MASTER_NAME_INCONTAINER,
+				},
+			})
+			Expect(err).NotTo(HaveOccurred())
+			m, err := netlink.LinkByName(MASTER_NAME_INCONTAINER)
+			Expect(err).NotTo(HaveOccurred())
+			err = netlink.LinkSetUp(m)
+			Expect(err).NotTo(HaveOccurred())
+			return nil
+		})
+		Expect(err).NotTo(HaveOccurred())
 	})
 
 	AfterEach(func() {
@@ -207,6 +227,13 @@ var _ = Describe("vlan Operations", func() {
 		Expect(testutils.UnmountNS(targetNS)).To(Succeed())
 	})
 
+	for _, inContainer := range []bool{false, true} {
+		masterInterface := MASTER_NAME
+		if inContainer {
+			masterInterface = MASTER_NAME_INCONTAINER
+		}
+		isInContainer := inContainer // Tests need a local var with constant value
+
 		for _, ver := range testutils.AllSpecVersions {
 			// Redefine ver inside for scope so real value is picked up by each dynamically defined It()
 			// See Gingkgo's "Patterns for dynamically generating tests" documentation.
@@ -219,9 +246,10 @@ var _ = Describe("vlan Operations", func() {
 						Name:       "testConfig",
 						Type:       "vlan",
 					},
-				Master: MASTER_NAME,
+					Master:     masterInterface,
 					VlanId:     33,
 					MTU:        1500,
+					LinkContNs: isInContainer,
 				}
 
 				// Create vlan in other namespace
@@ -254,15 +282,21 @@ var _ = Describe("vlan Operations", func() {
 						Name:       "testConfig",
 						Type:       "vlan",
 					},
-				Master: MASTER_NAME,
+					Master:     masterInterface,
 					VlanId:     33,
+					LinkContNs: isInContainer,
 				}
 
 				// Create vlan in other namespace
-			err := originalNS.Do(func(ns.NetNS) error {
+				otherNs := originalNS
+				if isInContainer {
+					otherNs = targetNS
+				}
+
+				err := otherNs.Do(func(ns.NetNS) error {
 					defer GinkgoRecover()
 
-				m, err := netlink.LinkByName(MASTER_NAME)
+					m, err := netlink.LinkByName(masterInterface)
 					Expect(err).NotTo(HaveOccurred())
 					err = netlink.LinkSetMTU(m, 1200)
 					Expect(err).NotTo(HaveOccurred())
@@ -287,7 +321,7 @@ var _ = Describe("vlan Operations", func() {
 			})
 
 			It(fmt.Sprintf("[%s] configures and deconfigures a vlan link with ADD/CHECK/DEL", ver), func() {
-			const IFNAME = "eth0"
+				const IFNAME = "ethX"
 
 				conf := fmt.Sprintf(`{
 			    "cniVersion": "%s",
@@ -295,12 +329,13 @@ var _ = Describe("vlan Operations", func() {
 			    "type": "vlan",
 			    "master": "%s",
 			    "vlanId": 1234,
+			    "linkInContainer": %t,
 			    "ipam": {
 				"type": "host-local",
 				"subnet": "10.1.2.0/24",
 				"dataDir": "%s"
 			    }
-			}`, ver, MASTER_NAME, dataDir)
+			}`, ver, masterInterface, isInContainer, dataDir)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -358,6 +393,9 @@ var _ = Describe("vlan Operations", func() {
 
 				newConf, err := buildOneConfig("vlanTestv4", ver, n, result)
 				Expect(err).NotTo(HaveOccurred())
+				if isInContainer {
+					newConf.LinkContNs = true
+				}
 
 				confString, err := json.Marshal(newConf)
 				Expect(err).NotTo(HaveOccurred())
@@ -369,6 +407,7 @@ var _ = Describe("vlan Operations", func() {
 					defer GinkgoRecover()
 					return testutils.CmdCheckWithArgs(args, func() error { return cmdCheck(args) })
 				})
+
 				if testutils.SpecVersionHasCHECK(ver) {
 					Expect(err).NotTo(HaveOccurred())
 				} else {
@@ -420,6 +459,7 @@ var _ = Describe("vlan Operations", func() {
 			    "type": "vlan",
 			    "master": "%s",
 			    "mtu": %d,
+			    "linkInContainer": %t,
 			    "ipam": {
 				"type": "host-local",
 				"subnet": "10.1.2.0/24",
@@ -429,11 +469,16 @@ var _ = Describe("vlan Operations", func() {
 
 				BeforeEach(func() {
 					var err error
-				err = originalNS.Do(func(ns.NetNS) error {
+					sourceNS := originalNS
+					if isInContainer {
+						sourceNS = targetNS
+					}
+
+					err = sourceNS.Do(func(ns.NetNS) error {
 						defer GinkgoRecover()
 
 						// set master link's MTU to 1500
-					link, err := netlink.LinkByName(MASTER_NAME)
+						link, err := netlink.LinkByName(masterInterface)
 						Expect(err).NotTo(HaveOccurred())
 						err = netlink.LinkSetMTU(link, 1500)
 						Expect(err).NotTo(HaveOccurred())
@@ -445,12 +490,11 @@ var _ = Describe("vlan Operations", func() {
 
 				It(fmt.Sprintf("[%s] fails to create vlan link with greater MTU than master interface", ver), func() {
 					var err error
-
 					args := &skel.CmdArgs{
 						ContainerID: "dummy",
-					Netns:       "/var/run/netns/test",
+						Netns:       targetNS.Path(),
-					IfName:      "eth0",
+						IfName:      "ethX",
-					StdinData:   []byte(fmt.Sprintf(confFmt, ver, MASTER_NAME, 1600, dataDir)),
+						StdinData:   []byte(fmt.Sprintf(confFmt, ver, masterInterface, 1600, isInContainer, dataDir)),
 					}
 
 					_ = originalNS.Do(func(netNS ns.NetNS) error {
@@ -469,9 +513,9 @@ var _ = Describe("vlan Operations", func() {
 
 					args := &skel.CmdArgs{
 						ContainerID: "dummy",
-					Netns:       "/var/run/netns/test",
+						Netns:       targetNS.Path(),
-					IfName:      "eth0",
+						IfName:      "ethX",
-					StdinData:   []byte(fmt.Sprintf(confFmt, ver, MASTER_NAME, -100, dataDir)),
+						StdinData:   []byte(fmt.Sprintf(confFmt, ver, masterInterface, -100, isInContainer, dataDir)),
 					}
 
 					_ = originalNS.Do(func(netNS ns.NetNS) error {
@@ -486,4 +530,5 @@ var _ = Describe("vlan Operations", func() {
 				})
 			})
 		}
+	}
 })