/
ipvlan.go
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/
ipvlan.go
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// 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/vishvananda/netlink"
"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/containernetworking/plugins/pkg/ip"
"github.com/containernetworking/plugins/pkg/ipam"
"github.com/containernetworking/plugins/pkg/ns"
bv "github.com/containernetworking/plugins/pkg/utils/buildversion"
)
type NetConf struct {
types.NetConf
Master string `json:"master"`
Mode string `json:"mode"`
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, cmdCheck bool) (*NetConf, string, error) {
n := &NetConf{}
if err := json.Unmarshal(bytes, n); err != nil {
return nil, "", fmt.Errorf("failed to load netconf: %v", err)
}
if cmdCheck {
return n, n.CNIVersion, nil
}
var result *current.Result
var err error
// Parse previous result
if n.NetConf.RawPrevResult != nil {
if err = version.ParsePrevResult(&n.NetConf); err != nil {
return nil, "", fmt.Errorf("could not parse prevResult: %v", err)
}
result, err = current.NewResultFromResult(n.PrevResult)
if err != nil {
return nil, "", fmt.Errorf("could not convert result to current version: %v", err)
}
}
if n.Master == "" {
if result == nil {
return nil, "", fmt.Errorf(`"master" field is required. It specifies the host interface name to virtualize`)
}
if len(result.Interfaces) == 1 && result.Interfaces[0].Name != "" {
n.Master = result.Interfaces[0].Name
} else {
return nil, "", fmt.Errorf("chained master failure. PrevResult lacks a single named interface")
}
}
return n, n.CNIVersion, nil
}
func modeFromString(s string) (netlink.IPVlanMode, error) {
switch s {
case "", "l2":
return netlink.IPVLAN_MODE_L2, nil
case "l3":
return netlink.IPVLAN_MODE_L3, nil
case "l3s":
return netlink.IPVLAN_MODE_L3S, nil
default:
return 0, fmt.Errorf("unknown ipvlan mode: %q", s)
}
}
func modeToString(mode netlink.IPVlanMode) (string, error) {
switch mode {
case netlink.IPVLAN_MODE_L2:
return "l2", nil
case netlink.IPVLAN_MODE_L3:
return "l3", nil
case netlink.IPVLAN_MODE_L3S:
return "l3s", nil
default:
return "", fmt.Errorf("unknown ipvlan mode: %q", mode)
}
}
func createIpvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Interface, error) {
ipvlan := ¤t.Interface{}
mode, err := modeFromString(conf.Mode)
if err != nil {
return nil, err
}
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
}
mv := &netlink.IPVlan{
LinkAttrs: netlink.LinkAttrs{
MTU: conf.MTU,
Name: tmpName,
ParentIndex: m.Attrs().Index,
Namespace: netlink.NsFd(int(netns.Fd())),
},
Mode: mode,
}
if err := netlink.LinkAdd(mv); err != nil {
return nil, fmt.Errorf("failed to create ipvlan: %v", err)
}
err = netns.Do(func(_ ns.NetNS) error {
err := ip.RenameLink(tmpName, ifName)
if err != nil {
return fmt.Errorf("failed to rename ipvlan to %q: %v", ifName, err)
}
ipvlan.Name = ifName
// Re-fetch ipvlan to get all properties/attributes
contIpvlan, err := netlink.LinkByName(ipvlan.Name)
if err != nil {
return fmt.Errorf("failed to refetch ipvlan %q: %v", ipvlan.Name, err)
}
ipvlan.Mac = contIpvlan.Attrs().HardwareAddr.String()
ipvlan.Sandbox = netns.Path()
return nil
})
if err != nil {
return nil, err
}
return ipvlan, nil
}
func cmdAdd(args *skel.CmdArgs) error {
n, cniVersion, err := loadConf(args.StdinData, false)
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()
ipvlanInterface, err := createIpvlan(n, args.IfName, netns)
if err != nil {
return err
}
var result *current.Result
// Configure iface from PrevResult if we have IPs and an IPAM
// block has not been configured
haveResult := false
if n.IPAM.Type == "" && n.PrevResult != nil {
result, err = current.NewResultFromResult(n.PrevResult)
if err != nil {
return err
}
if len(result.IPs) > 0 {
haveResult = true
}
}
if !haveResult {
// 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
}
// Invoke ipam del if err to avoid ip leak
defer func() {
if err != nil {
ipam.ExecDel(n.IPAM.Type, args.StdinData)
}
}()
// 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 ipvlan interface
ipc.Interface = current.Int(0)
}
result.Interfaces = []*current.Interface{ipvlanInterface}
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, false)
if err != nil {
return err
}
// On chained invocation, IPAM block can be empty
if n.IPAM.Type != "" {
err = ipam.ExecDel(n.IPAM.Type, args.StdinData)
if err != nil {
return err
}
}
if args.Netns == "" {
return nil
}
// There is a netns so try to clean up. Delete can be called multiple times
// so don't return an error if the device is already removed.
err = ns.WithNetNSPath(args.Netns, func(_ ns.NetNS) error {
if err := ip.DelLinkByName(args.IfName); err != nil {
if err != ip.ErrLinkNotFound {
return err
}
}
return nil
})
return err
}
func main() {
skel.PluginMain(cmdAdd, cmdCheck, cmdDel, version.All, bv.BuildString("ipvlan"))
}
func cmdCheck(args *skel.CmdArgs) error {
n, _, err := loadConf(args.StdinData, true)
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()
if n.IPAM.Type != "" {
// run the IPAM plugin and get back the config to apply
err = ipam.ExecCheck(n.IPAM.Type, args.StdinData)
if err != nil {
return err
}
}
// Parse previous result.
if n.NetConf.RawPrevResult == nil {
return fmt.Errorf("Required prevResult missing")
}
if err := version.ParsePrevResult(&n.NetConf); err != nil {
return err
}
result, err := current.NewResultFromResult(n.PrevResult)
if err != nil {
return err
}
var contMap current.Interface
// Find interfaces for names whe know, ipvlan inside container
for _, intf := range result.Interfaces {
if args.IfName == intf.Name {
if args.Netns == intf.Sandbox {
contMap = *intf
continue
}
}
}
// The namespace must be the same as what was configured
if args.Netns != contMap.Sandbox {
return fmt.Errorf("Sandbox in prevResult %s doesn't match configured netns: %s",
contMap.Sandbox, args.Netns)
}
m, err := netlink.LinkByName(n.Master)
if err != nil {
return fmt.Errorf("failed to lookup master %q: %v", n.Master, err)
}
// Check prevResults for ips, routes and dns against values found in the container
if err := netns.Do(func(_ ns.NetNS) error {
// Check interface against values found in the container
err := validateCniContainerInterface(contMap, m.Attrs().Index, n.Mode)
if err != nil {
return err
}
err = ip.ValidateExpectedInterfaceIPs(args.IfName, result.IPs)
if err != nil {
return err
}
err = ip.ValidateExpectedRoute(result.Routes)
if err != nil {
return err
}
return nil
}); err != nil {
return err
}
return nil
}
func validateCniContainerInterface(intf current.Interface, masterIndex int, modeExpected string) error {
var link netlink.Link
var err error
if intf.Name == "" {
return fmt.Errorf("Container interface name missing in prevResult: %v", intf.Name)
}
link, err = netlink.LinkByName(intf.Name)
if err != nil {
return fmt.Errorf("Container Interface name in prevResult: %s not found", intf.Name)
}
if intf.Sandbox == "" {
return fmt.Errorf("Error: Container interface %s should not be in host namespace", link.Attrs().Name)
}
ipv, isIPVlan := link.(*netlink.IPVlan)
if !isIPVlan {
return fmt.Errorf("Error: Container interface %s not of type ipvlan", link.Attrs().Name)
}
mode, err := modeFromString(modeExpected)
if ipv.Mode != mode {
currString, err := modeToString(ipv.Mode)
if err != nil {
return err
}
confString, err := modeToString(mode)
if err != nil {
return err
}
return fmt.Errorf("Container IPVlan mode %s does not match expected value: %s", currString, confString)
}
if intf.Mac != "" {
if intf.Mac != link.Attrs().HardwareAddr.String() {
return fmt.Errorf("Interface %s Mac %s doesn't match container Mac: %s", intf.Name, intf.Mac, link.Attrs().HardwareAddr)
}
}
return nil
}