Add the tun mounting with vhost is requested

This commit add also the tun device into the container. This is needed to create tap devices inside the container network namespace Vhost-net is used to accelerate the dpdk connected to kernel networking using tap devices. Signed-off-by: Sebastian Sch <[email protected]>
k8snetworkplumbingwg · Nov 15, 2021 · 0427aef · 0427aef
1 parent f493de7
commit 0427aef
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Showing 4 changed files with 29 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -232,7 +232,7 @@ This selector is applicable when "deviceType" is "netDevice"(note: this is defau
 | "linkTypes"   | N        | The link type of the net device associated with the PCI device | `string` list Default: `null`                     | "linkTypes": ["ether"]                                                                           |
 | "ddpProfiles" | N        | A map of device selectors                                      | `string` list Default: `null`                     | "ddpProfiles": ["GTPv1-C/U IPv4/IPv6 payload"]                                                   |
 | "isRdma"      | N        | Mount RDMA resources                                           | `bool`  values `true` or `false` Default: `false` | "isRdma": `true`                                                                                 |
-| "needVhostNet"| N        | Share /dev/vhost-net                                           | `bool`  values `true` or `false` Default: `false` | "needVhostNet": `true`                                                                           |
+| "needVhostNet"| N        | Share /dev/vhost-net and /dev/net/tun                          | `bool`  values `true` or `false` Default: `false` | "needVhostNet": `true`                                                                           |
 
 
 [//]: # (The tables above generated using: https://ozh.github.io/ascii-tables/)

diff --git a/pkg/netdevice/netInfoProviders.go b/pkg/netdevice/netInfoProviders.go
@@ -76,7 +76,15 @@ func (rip *vhostNetInfoProvider) GetDeviceSpecs() []*pluginapi.DeviceSpec {
 		glog.Errorf("GetDeviceSpecs(): /dev/vhost-net doesn't exist")
 		return nil
 	}
-	return GetVhostNetDeviceSpec()
+	deviceSpec := GetVhostNetDeviceSpec()
+
+	if !TunDeviceExist() {
+		glog.Errorf("GetDeviceSpecs(): /dev/net/tun doesn't exist")
+		return nil
+	}
+	deviceSpec = append(deviceSpec, GetTunDeviceSpec()...)
+
+	return deviceSpec
 }
 
 func (rip *vhostNetInfoProvider) GetEnvVal() string {

diff --git a/pkg/netdevice/pciNetDevice_test.go b/pkg/netdevice/pciNetDevice_test.go
@@ -247,7 +247,7 @@ var _ = Describe("PciNetDevice", func() {
 				Expect(dev.GetDriver()).To(Equal("vfio-pci"))
 				Expect(dev.GetNetName()).To(Equal(""))
 				Expect(dev.GetEnvVal()).To(Equal("0000:00:00.1"))
-				Expect(dev.GetDeviceSpecs()).To(HaveLen(3)) // /dev/vfio/vfio0 and default /dev/vfio/vfio + vhost-net
+				Expect(dev.GetDeviceSpecs()).To(HaveLen(4)) // /dev/vfio/vfio0 and default /dev/vfio/vfio + vhost-net + tun
 				Expect(dev.GetRdmaSpec().IsRdma()).To(BeFalse())
 				Expect(dev.GetRdmaSpec().GetRdmaDeviceSpec()).To(HaveLen(0))
 				Expect(dev.GetLinkType()).To(Equal(""))

diff --git a/pkg/netdevice/vhostNet.go b/pkg/netdevice/vhostNet.go
@@ -23,3 +23,21 @@ func GetVhostNetDeviceSpec() []*pluginapi.DeviceSpec {
 
 	return deviceSpec
 }
+
+// TunDeviceExist returns true if /dev/net/tun exists
+func TunDeviceExist() bool {
+	_, err := os.Stat("/dev/net/tun")
+	return err == nil
+}
+
+// GetTunDeviceSpec returns an instance of DeviceSpec for Tun
+func GetTunDeviceSpec() []*pluginapi.DeviceSpec {
+	deviceSpec := make([]*pluginapi.DeviceSpec, 0)
+	deviceSpec = append(deviceSpec, &pluginapi.DeviceSpec{
+		HostPath:      "/dev/net/tun",
+		ContainerPath: "/dev/net/tun",
+		Permissions:   "mrw",
+	})
+
+	return deviceSpec
+}