Merge pull request #966 from sboeuf/master

networking: libsnnet: Make API more explicit and get existing VNIC device by name

networking/libsnnet/cn.go

@@ -974,7 +974,12 @@ func createAndEnableVnic(vnic *Vnic, bridge *Bridge) error {
 	if err := vnic.Create(); err != nil {
 		return fmt.Errorf("VNIC creation failed %s %s", vnic.GlobalID, err.Error())
 	}
-	if err := vnic.SetHardwareAddr(*vnic.MACAddr); err != nil {
+
+	vnicPeer, err := initializeVnicPeer(vnic)
+	if err != nil {
+		return fmt.Errorf("VNIC Initialize Peer %s %s", vnic.GlobalID, err.Error())
+	}
+	if err := vnicPeer.SetHardwareAddr(*vnic.MACAddr); err != nil {
 		return fmt.Errorf("VNIC Set MAC Address %s %s", vnic.GlobalID, err.Error())
 	}
 	if err := vnic.SetMTU(vnic.MTU); err != nil {
@@ -990,6 +995,34 @@ func createAndEnableVnic(vnic *Vnic, bridge *Bridge) error {
 	return nil
 }
 
+func initializeVnicPeer(vnic *Vnic) (*Vnic, error) {
+	switch vnic.Role {
+	case TenantVM:
+		return vnic, nil
+	case TenantContainer:
+		vnicPeer, err := NewContainerVnic(vnic.GlobalID)
+		if err != nil {
+			return nil, err
+		}
+		vnicPeer.LinkName = vnic.PeerName()
+
+		vnicPeer.Link = &netlink.Veth{
+			LinkAttrs: netlink.LinkAttrs{
+				Name: vnic.PeerName(),
+			},
+			PeerName: vnic.LinkName,
+		}
+
+		if err := vnicPeer.GetDeviceByName(vnicPeer.LinkName); err != nil {
+			return nil, err
+		}
+
+		return vnicPeer, nil
+	}
+
+	return nil, fmt.Errorf("Unknown VNIC tenant type")
+}
+
 func apiCancelled(cancel chan interface{}) bool {
 	select {
 	case <-cancel:

networking/libsnnet/vnic.go

@@ -17,6 +17,7 @@
 package libsnnet
 
 import (
+	"fmt"
 	"net"
 	"strings"
 	"syscall"
@@ -69,10 +70,12 @@ func (v *Vnic) PeerName() string {
 	if strings.HasPrefix(v.LinkName, prefixVnicHost) {
 		return strings.Replace(v.LinkName, prefixVnicHost, prefixVnicCont, 1)
 	}
+
 	if strings.HasPrefix(v.LinkName, prefixVnicCont) {
 		return strings.Replace(v.LinkName, prefixVnicCont, prefixVnicHost, 1)
 	}
-	return ""
+
+	return fmt.Sprintf("%s_peer", v.LinkName)
 }
 
 // GetDevice is used to associate with an existing VNIC provided it satisfies
@@ -119,6 +122,46 @@ func (v *Vnic) GetDevice() error {
 	return nil
 }
 
+// GetDeviceByName is used to associate with an existing VNIC relying on its
+// link name instead of its alias. Returns error if the VNIC does not exist
+func (v *Vnic) GetDeviceByName(linkName string) error {
+
+	link, err := netlink.LinkByName(linkName)
+	if err != nil {
+		return netError(v, "get device interface does not exist: %v", linkName)
+	}
+
+	switch v.Role {
+	case TenantVM:
+		vl, ok := link.(*netlink.GenericLink)
+		if !ok {
+			return netError(v, "get device incorrect interface type %v %v", linkName, link.Type())
+		}
+
+		// TODO: Why do both tun and tap interfaces return the type tun
+		if link.Type() != "tun" {
+			return netError(v, "get device incorrect interface type %v %v", linkName, link.Type())
+		}
+
+		if flags := uint(link.Attrs().Flags); (flags & syscall.IFF_TAP) == 0 {
+			return netError(v, "get device incorrect interface type %v %v", linkName, link)
+		}
+		v.LinkName = vl.Name
+		v.Link = vl
+	case TenantContainer:
+		vl, ok := link.(*netlink.Veth)
+		if !ok {
+			return netError(v, "get device incorrect interface type %v %v", linkName, link.Type())
+		}
+		v.LinkName = vl.Name
+		v.Link = vl
+	default:
+		return netError(v, " invalid or unsupported VNIC type %v", linkName)
+	}
+
+	return nil
+}
+
 func createVMVnic(v *Vnic) (link netlink.Link, err error) {
 
 	tap := &netlink.Tuntap{
@@ -347,14 +390,8 @@ func (v *Vnic) SetHardwareAddr(addr net.HardwareAddr) error {
 		/* Set by QEMU. */
 	case TenantContainer:
 		/* Need to set the MAC on the container side */
-		peerVeth := &netlink.Veth{
-			LinkAttrs: netlink.LinkAttrs{
-				Name: v.PeerName(),
-			},
-			PeerName: v.LinkName,
-		}
-		if err := netlink.LinkSetHardwareAddr(peerVeth, addr); err != nil {
-			return netError(v, "link set peer mtu %v", err)
+		if err := netlink.LinkSetHardwareAddr(v.Link, addr); err != nil {
+			return netError(v, "link set hardware addr %v", err)
 		}
 	}
 

networking/libsnnet/vnic_test.go

@@ -184,6 +184,52 @@ func TestVnicContainer_GetDevice(t *testing.T) {
 	performVnicOps(true, assert, vnic)
 }
 
+//Test ability to attach to an existing VNIC
+//
+//Tests the ability to attach to an existing
+//VNIC and perform all VNIC operations on it
+//
+//Test is expected to pass
+func TestVnic_GetDeviceByName(t *testing.T) {
+	assert := assert.New(t)
+	vnic1, _ := NewVnic("testvnic")
+	vnic1.LinkName = "testiface"
+
+	assert.Nil(vnic1.Create())
+	vnic, _ := NewVnic("testvnic")
+
+	assert.Nil(vnic.GetDeviceByName("testiface"))
+	assert.NotEqual(vnic.InterfaceName(), "")
+	assert.Equal(vnic.InterfaceName(), vnic1.InterfaceName())
+	assert.NotEqual(vnic1.PeerName(), "")
+	assert.Equal(vnic1.PeerName(), vnic.PeerName())
+
+	performVnicOps(true, assert, vnic)
+}
+
+//Test ability to attach to an existing Container VNIC
+//
+//Tests the ability to attach to an existing
+//VNIC and perform all VNIC operations on it
+//
+//Test is expected to pass
+func TestVnicContainer_GetDeviceByName(t *testing.T) {
+	assert := assert.New(t)
+
+	vnic1, err := NewContainerVnic("testvnic")
+	assert.Nil(err)
+	vnic1.LinkName = "testiface"
+
+	err = vnic1.Create()
+	assert.Nil(err)
+
+	vnic, err := NewContainerVnic("testvnic")
+	assert.Nil(err)
+
+	assert.Nil(vnic.GetDeviceByName("testiface"))
+	performVnicOps(true, assert, vnic)
+}
+
 //Tests VNIC attach to a bridge
 //
 //Tests all interactions between VNIC and Bridge