plugins: move vlan to plugins/main/

plugins/main/vlan/vlan.go

@@ -0,0 +1,197 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"runtime"
+
+	"github.com/containernetworking/cni/pkg/ip"
+	"github.com/containernetworking/cni/pkg/ipam"
+	"github.com/containernetworking/cni/pkg/ns"
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/pkg/types"
+	"github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containernetworking/cni/pkg/version"
+	"github.com/vishvananda/netlink"
+)
+
+type NetConf struct {
+	types.NetConf
+	Master string `json:"master"`
+	VlanId int    `json:"vlanId"`
+	MTU    int    `json:"mtu,omitempty"`
+}
+
+func init() {
+	// this ensures that main runs only on main thread (thread group leader).
+	// since namespace ops (unshare, setns) are done for a single thread, we
+	// must ensure that the goroutine does not jump from OS thread to thread
+	runtime.LockOSThread()
+}
+
+func loadConf(bytes []byte) (*NetConf, string, error) {
+	n := &NetConf{}
+	if err := json.Unmarshal(bytes, n); err != nil {
+		return nil, "", fmt.Errorf("failed to load netconf: %v", err)
+	}
+	if n.Master == "" {
+		return nil, "", fmt.Errorf(`"master" field is required. It specifies the host interface name to create the VLAN for.`)
+	}
+	if n.VlanId < 0 || n.VlanId > 4094 {
+		return nil, "", fmt.Errorf(`invalid VLAN ID %d (must be between 0 and 4095 inclusive)`, n.VlanId)
+	}
+	return n, n.CNIVersion, nil
+}
+
+func createVlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Interface, error) {
+	vlan := &current.Interface{}
+
+	m, err := netlink.LinkByName(conf.Master)
+	if err != nil {
+		return nil, fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
+	}
+
+	// due to kernel bug we have to create with tmpname or it might
+	// collide with the name on the host and error out
+	tmpName, err := ip.RandomVethName()
+	if err != nil {
+		return nil, err
+	}
+
+	if conf.MTU <= 0 {
+		conf.MTU = m.Attrs().MTU
+	}
+
+	v := &netlink.Vlan{
+		LinkAttrs: netlink.LinkAttrs{
+			MTU:         conf.MTU,
+			Name:        tmpName,
+			ParentIndex: m.Attrs().Index,
+			Namespace:   netlink.NsFd(int(netns.Fd())),
+		},
+		VlanId: conf.VlanId,
+	}
+
+	if err := netlink.LinkAdd(v); err != nil {
+		return nil, fmt.Errorf("failed to create vlan: %v", err)
+	}
+
+	err = netns.Do(func(_ ns.NetNS) error {
+		err := ip.RenameLink(tmpName, ifName)
+		if err != nil {
+			return fmt.Errorf("failed to rename vlan to %q: %v", ifName, err)
+		}
+		vlan.Name = ifName
+
+		// Re-fetch interface to get all properties/attributes
+		contVlan, err := netlink.LinkByName(vlan.Name)
+		if err != nil {
+			return fmt.Errorf("failed to refetch vlan %q: %v", vlan.Name, err)
+		}
+		vlan.Mac = contVlan.Attrs().HardwareAddr.String()
+		vlan.Sandbox = netns.Path()
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return vlan, nil
+}
+
+func cmdAdd(args *skel.CmdArgs) error {
+	n, cniVersion, err := loadConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	netns, err := ns.GetNS(args.Netns)
+	if err != nil {
+		return fmt.Errorf("failed to open netns %q: %v", args.Netns, err)
+	}
+	defer netns.Close()
+
+	vlanInterface, err := createVlan(n, args.IfName, netns)
+	if err != nil {
+		return err
+	}
+
+	// run the IPAM plugin and get back the config to apply
+	r, err := ipam.ExecAdd(n.IPAM.Type, args.StdinData)
+	if err != nil {
+		return err
+	}
+	// Convert whatever the IPAM result was into the current Result type
+	result, err := current.NewResultFromResult(r)
+	if err != nil {
+		return err
+	}
+
+	if len(result.IPs) == 0 {
+		return errors.New("IPAM plugin returned missing IP config")
+	}
+	for _, ipc := range result.IPs {
+		// All addresses belong to the vlan interface
+		ipc.Interface = 0
+	}
+
+	result.Interfaces = []*current.Interface{vlanInterface}
+
+	err = netns.Do(func(_ ns.NetNS) error {
+		return ipam.ConfigureIface(args.IfName, result)
+	})
+	if err != nil {
+		return err
+	}
+
+	result.DNS = n.DNS
+
+	return types.PrintResult(result, cniVersion)
+}
+
+func cmdDel(args *skel.CmdArgs) error {
+	n, _, err := loadConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	err = ipam.ExecDel(n.IPAM.Type, args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	if args.Netns == "" {
+		return nil
+	}
+
+	err = ns.WithNetNSPath(args.Netns, func(_ ns.NetNS) error {
+		_, err = ip.DelLinkByNameAddr(args.IfName, netlink.FAMILY_V4)
+		// FIXME: use ip.ErrLinkNotFound when cni is revendored
+		if err != nil && err.Error() == "Link not found" {
+			return nil
+		}
+		return err
+	})
+
+	return err
+}
+
+func main() {
+	skel.PluginMain(cmdAdd, cmdDel, version.All)
+}