plugins: add ipvlan main plugin

plugins/main/ipvlan/ipvlan.go

@@ -0,0 +1,173 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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"
+	"os"
+	"runtime"
+
+	"github.com/appc/cni/Godeps/_workspace/src/github.com/vishvananda/netlink"
+	"github.com/appc/cni/pkg/ip"
+	"github.com/appc/cni/pkg/ns"
+	"github.com/appc/cni/pkg/plugin"
+	"github.com/appc/cni/pkg/skel"
+)
+
+type NetConf struct {
+	plugin.NetConf
+	Master string `json:"master"`
+	Mode   string `json:"mode"`
+	IPMasq bool   `json:"ipMasq"`
+	MTU    int    `json:"mtu"`
+}
+
+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, 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 virtualize`)
+	}
+	return n, nil
+}
+
+func modeFromString(s string) (netlink.IPVlanMode, error) {
+	switch s {
+	case "":
+		return netlink.IPVLAN_MODE_L2, nil
+	case "l2":
+		return netlink.IPVLAN_MODE_L2, nil
+	case "l3":
+		return netlink.IPVLAN_MODE_L3, nil
+	default:
+		return 0, fmt.Errorf("unknown ipvlan mode: %q", s)
+	}
+}
+
+func createIpvlan(conf *NetConf, ifName string, netns *os.File) error {
+	mode, err := modeFromString(conf.Mode)
+	if err != nil {
+		return err
+	}
+
+	m, err := netlink.LinkByName(conf.Master)
+	if err != nil {
+		return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
+	}
+
+	mv := &netlink.IPVlan{
+		LinkAttrs: netlink.LinkAttrs{
+			MTU:         conf.MTU,
+			Name:        ifName,
+			ParentIndex: m.Attrs().Index,
+			Namespace:   netlink.NsFd(int(netns.Fd())),
+		},
+		Mode: mode,
+	}
+
+	if err := netlink.LinkAdd(mv); err != nil {
+		return fmt.Errorf("failed to create ipvlan: %v", err)
+	}
+
+	return err
+}
+
+func cmdAdd(args *skel.CmdArgs) error {
+	n, err := loadConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	netns, err := os.Open(args.Netns)
+	if err != nil {
+		return fmt.Errorf("failed to open netns %q: %v", netns, err)
+	}
+	defer netns.Close()
+
+	tmpName := ip.RandomVethName(args.Netns)
+	if err = createIpvlan(n, tmpName, netns); err != nil {
+		return err
+	}
+
+	// run the IPAM plugin and get back the config to apply
+	result, err := plugin.ExecAdd(n.IPAM.Type, args.StdinData)
+	if err != nil {
+		return err
+	}
+	if result.IP4 == nil {
+		return errors.New("IPAM plugin returned missing IPv4 config")
+	}
+
+	err = ns.WithNetNS(netns, func(_ *os.File) error {
+		err := renameLink(tmpName, args.IfName)
+		if err != nil {
+			return fmt.Errorf("failed to rename ipvlan to %q: %v", args.IfName, err)
+		}
+
+		return plugin.ConfigureIface(args.IfName, result)
+	})
+	if err != nil {
+		return err
+	}
+
+	if n.IPMasq {
+		chain := "CNI-" + n.Name
+		if err = ip.SetupIPMasq(ip.Network(&result.IP4.IP), chain); err != nil {
+			return err
+		}
+	}
+
+	return plugin.PrintResult(result)
+}
+
+func cmdDel(args *skel.CmdArgs) error {
+	n, err := loadConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	err = plugin.ExecDel(n.IPAM.Type, args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	return ns.WithNetNSPath(args.Netns, func(hostNS *os.File) error {
+		return ip.DelLinkByName(args.IfName)
+	})
+}
+
+func renameLink(curName, newName string) error {
+	link, err := netlink.LinkByName(curName)
+	if err != nil {
+		return err
+	}
+
+	return netlink.LinkSetName(link, newName)
+}
+
+func main() {
+	skel.PluginMain(cmdAdd, cmdDel)
+}