plugins/main/dummy/dummy.go - third_party/cni-plugins - Git at Google

 // Copyright 2022 Arista Networks
 //
 // 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"
 	"net"

 	"github.com/vishvananda/netlink"

 	"github.com/containernetworking/cni/pkg/skel"
 	"github.com/containernetworking/cni/pkg/types"
 	current "github.com/containernetworking/cni/pkg/types/100"
 	"github.com/containernetworking/cni/pkg/version"
 	"github.com/containernetworking/plugins/pkg/ip"
 	"github.com/containernetworking/plugins/pkg/ipam"
 	"github.com/containernetworking/plugins/pkg/netlinksafe"
 	"github.com/containernetworking/plugins/pkg/ns"
 	bv "github.com/containernetworking/plugins/pkg/utils/buildversion"
 )

 func parseNetConf(bytes []byte) (*types.NetConf, error) {
 	conf := &types.NetConf{}
 	if err := json.Unmarshal(bytes, conf); err != nil {
 		return nil, fmt.Errorf("failed to parse network config: %v", err)
 	}
 	return conf, nil
 }

 func createDummy(ifName string, netns ns.NetNS) (*current.Interface, error) {
 	dummy := &current.Interface{}

 	err := netns.Do(func(_ ns.NetNS) error {
 		linkAttrs := netlink.NewLinkAttrs()
 		linkAttrs.Name = ifName

 		dm := &netlink.Dummy{
 			LinkAttrs: linkAttrs,
 		}

 		if err := netlink.LinkAdd(dm); err != nil {
 			return fmt.Errorf("failed to create dummy: %v", err)
 		}
 		dummy.Name = ifName

 		// Re-fetch interface to get all properties/attributes
 		contDummy, err := netlinksafe.LinkByName(ifName)
 		if err != nil {
 			return fmt.Errorf("failed to fetch dummy%q: %v", ifName, err)
 		}

 		dummy.Mac = contDummy.Attrs().HardwareAddr.String()
 		dummy.Sandbox = netns.Path()

 		return nil
 	})
 	if err != nil {
 		return nil, err
 	}

 	return dummy, nil
 }

 func cmdAdd(args *skel.CmdArgs) error {
 	conf, err := parseNetConf(args.StdinData)
 	if err != nil {
 		return err
 	}

 	if conf.IPAM.Type == "" {
 		return errors.New("dummy interface requires an IPAM configuration")
 	}

 	netns, err := ns.GetNS(args.Netns)
 	if err != nil {
 		return fmt.Errorf("failed to open netns %q: %v", netns, err)
 	}
 	defer netns.Close()

 	dummyInterface, err := createDummy(args.IfName, netns)
 	if err != nil {
 		return err
 	}

 	// Delete link if err to avoid link leak in this ns
 	defer func() {
 		if err != nil {
 			netns.Do(func(_ ns.NetNS) error {
 				return ip.DelLinkByName(args.IfName)
 			})
 		}
 	}()

 	r, err := ipam.ExecAdd(conf.IPAM.Type, args.StdinData)
 	if err != nil {
 		return err
 	}

 	// defer ipam deletion to avoid ip leak
 	defer func() {
 		if err != nil {
 			ipam.ExecDel(conf.IPAM.Type, args.StdinData)
 		}
 	}()

 	// convert IPAMResult to 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 apply to the container dummy interface
 		ipc.Interface = current.Int(0)
 	}

 	result.Interfaces = []*current.Interface{dummyInterface}

 	err = netns.Do(func(_ ns.NetNS) error {
 		return ipam.ConfigureIface(args.IfName, result)
 	})
 	if err != nil {
 		return err
 	}

 	return types.PrintResult(result, conf.CNIVersion)
 }

 func cmdDel(args *skel.CmdArgs) error {
 	conf, err := parseNetConf(args.StdinData)
 	if err != nil {
 		return err
 	}

 	if err = ipam.ExecDel(conf.IPAM.Type, args.StdinData); err != nil {
 		return err
 	}

 	if args.Netns == "" {
 		return nil
 	}

 	err = ns.WithNetNSPath(args.Netns, func(ns.NetNS) error {
 		err = ip.DelLinkByName(args.IfName)
 		if err != nil && err == ip.ErrLinkNotFound {
 			return nil
 		}
 		return err
 	})
 	if err != nil {
 		//  if NetNs is passed down by the Cloud Orchestration Engine, or if it called multiple times
 		// so don't return an error if the device is already removed.
 		// https://github.com/kubernetes/kubernetes/issues/43014#issuecomment-287164444
 		_, ok := err.(ns.NSPathNotExistErr)
 		if ok {
 			return nil
 		}
 		return err
 	}

 	return nil
 }

 func main() {
 	skel.PluginMainFuncs(skel.CNIFuncs{
 		Add:    cmdAdd,
 		Check:  cmdCheck,
 		Del:    cmdDel,
 		Status: cmdStatus,
 		/* FIXME GC */
 	}, version.All, bv.BuildString("dummy"))
 }

 func cmdCheck(args *skel.CmdArgs) error {
 	conf, err := parseNetConf(args.StdinData)
 	if err != nil {
 		return err
 	}

 	if conf.IPAM.Type == "" {
 		return errors.New("dummy interface requires an IPAM configuration")
 	}

 	netns, err := ns.GetNS(args.Netns)
 	if err != nil {
 		return fmt.Errorf("failed to open netns %q: %v", args.Netns, err)
 	}
 	defer netns.Close()

 	// run the IPAM plugin and get back the config to apply
 	err = ipam.ExecCheck(conf.IPAM.Type, args.StdinData)
 	if err != nil {
 		return err
 	}

 	if conf.RawPrevResult == nil {
 		return fmt.Errorf("dummy: Required prevResult missing")
 	}

 	if err := version.ParsePrevResult(conf); err != nil {
 		return err
 	}

 	// Convert whatever the IPAM result was into the current Result type
 	result, err := current.NewResultFromResult(conf.PrevResult)
 	if err != nil {
 		return err
 	}

 	var contMap current.Interface
 	// Find interfaces for name whe know, that of dummy device 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)
 	}

 	//
 	// 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)
 		if err != nil {
 			return err
 		}

 		err = ip.ValidateExpectedInterfaceIPs(args.IfName, result.IPs)
 		if err != nil {
 			return err
 		}
 		return nil
 	}); err != nil {
 		return err
 	}

 	return nil
 }

 func validateCniContainerInterface(intf current.Interface) 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 = netlinksafe.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)
 	}

 	_, isDummy := link.(*netlink.Dummy)
 	if !isDummy {
 		return fmt.Errorf("Error: Container interface %s not of type dummy", link.Attrs().Name)
 	}

 	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)
 		}
 	}

 	if link.Attrs().Flags&net.FlagUp != net.FlagUp {
 		return fmt.Errorf("Interface %s is down", intf.Name)
 	}

 	return nil
 }

 func cmdStatus(args *skel.CmdArgs) error {
 	conf := types.NetConf{}
 	if err := json.Unmarshal(args.StdinData, &conf); err != nil {
 		return fmt.Errorf("failed to load netconf: %w", err)
 	}

 	if err := ipam.ExecStatus(conf.IPAM.Type, args.StdinData); err != nil {
 		return err
 	}

 	return nil
 }
	// Copyright 2022 Arista Networks
	//
	// 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"
	"net"

	"github.com/vishvananda/netlink"

	"github.com/containernetworking/cni/pkg/skel"
	"github.com/containernetworking/cni/pkg/types"
	current "github.com/containernetworking/cni/pkg/types/100"
	"github.com/containernetworking/cni/pkg/version"
	"github.com/containernetworking/plugins/pkg/ip"
	"github.com/containernetworking/plugins/pkg/ipam"
	"github.com/containernetworking/plugins/pkg/netlinksafe"
	"github.com/containernetworking/plugins/pkg/ns"
	bv "github.com/containernetworking/plugins/pkg/utils/buildversion"
	)

	func parseNetConf(bytes []byte) (*types.NetConf, error) {
	conf := &types.NetConf{}
	if err := json.Unmarshal(bytes, conf); err != nil {
	return nil, fmt.Errorf("failed to parse network config: %v", err)
	}
	return conf, nil
	}

	func createDummy(ifName string, netns ns.NetNS) (*current.Interface, error) {
	dummy := &current.Interface{}

	err := netns.Do(func(_ ns.NetNS) error {
	linkAttrs := netlink.NewLinkAttrs()
	linkAttrs.Name = ifName

	dm := &netlink.Dummy{
	LinkAttrs: linkAttrs,
	}

	if err := netlink.LinkAdd(dm); err != nil {
	return fmt.Errorf("failed to create dummy: %v", err)
	}
	dummy.Name = ifName

	// Re-fetch interface to get all properties/attributes
	contDummy, err := netlinksafe.LinkByName(ifName)
	if err != nil {
	return fmt.Errorf("failed to fetch dummy%q: %v", ifName, err)
	}

	dummy.Mac = contDummy.Attrs().HardwareAddr.String()
	dummy.Sandbox = netns.Path()

	return nil
	})
	if err != nil {
	return nil, err
	}

	return dummy, nil
	}

	func cmdAdd(args *skel.CmdArgs) error {
	conf, err := parseNetConf(args.StdinData)
	if err != nil {
	return err
	}

	if conf.IPAM.Type == "" {
	return errors.New("dummy interface requires an IPAM configuration")
	}

	netns, err := ns.GetNS(args.Netns)
	if err != nil {
	return fmt.Errorf("failed to open netns %q: %v", netns, err)
	}
	defer netns.Close()

	dummyInterface, err := createDummy(args.IfName, netns)
	if err != nil {
	return err
	}

	// Delete link if err to avoid link leak in this ns
	defer func() {
	if err != nil {
	netns.Do(func(_ ns.NetNS) error {
	return ip.DelLinkByName(args.IfName)
	})
	}
	}()

	r, err := ipam.ExecAdd(conf.IPAM.Type, args.StdinData)
	if err != nil {
	return err
	}

	// defer ipam deletion to avoid ip leak
	defer func() {
	if err != nil {
	ipam.ExecDel(conf.IPAM.Type, args.StdinData)
	}
	}()

	// convert IPAMResult to 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 apply to the container dummy interface
	ipc.Interface = current.Int(0)
	}

	result.Interfaces = []*current.Interface{dummyInterface}

	err = netns.Do(func(_ ns.NetNS) error {
	return ipam.ConfigureIface(args.IfName, result)
	})
	if err != nil {
	return err
	}

	return types.PrintResult(result, conf.CNIVersion)
	}

	func cmdDel(args *skel.CmdArgs) error {
	conf, err := parseNetConf(args.StdinData)
	if err != nil {
	return err
	}

	if err = ipam.ExecDel(conf.IPAM.Type, args.StdinData); err != nil {
	return err
	}

	if args.Netns == "" {
	return nil
	}

	err = ns.WithNetNSPath(args.Netns, func(ns.NetNS) error {
	err = ip.DelLinkByName(args.IfName)
	if err != nil && err == ip.ErrLinkNotFound {
	return nil
	}
	return err
	})
	if err != nil {
	// if NetNs is passed down by the Cloud Orchestration Engine, or if it called multiple times
	// so don't return an error if the device is already removed.
	// https://github.com/kubernetes/kubernetes/issues/43014#issuecomment-287164444
	_, ok := err.(ns.NSPathNotExistErr)
	if ok {
	return nil
	}
	return err
	}

	return nil
	}

	func main() {
	skel.PluginMainFuncs(skel.CNIFuncs{
	Add: cmdAdd,
	Check: cmdCheck,
	Del: cmdDel,
	Status: cmdStatus,
	/* FIXME GC */
	}, version.All, bv.BuildString("dummy"))
	}

	func cmdCheck(args *skel.CmdArgs) error {
	conf, err := parseNetConf(args.StdinData)
	if err != nil {
	return err
	}

	if conf.IPAM.Type == "" {
	return errors.New("dummy interface requires an IPAM configuration")
	}

	netns, err := ns.GetNS(args.Netns)
	if err != nil {
	return fmt.Errorf("failed to open netns %q: %v", args.Netns, err)
	}
	defer netns.Close()

	// run the IPAM plugin and get back the config to apply
	err = ipam.ExecCheck(conf.IPAM.Type, args.StdinData)
	if err != nil {
	return err
	}

	if conf.RawPrevResult == nil {
	return fmt.Errorf("dummy: Required prevResult missing")
	}

	if err := version.ParsePrevResult(conf); err != nil {
	return err
	}

	// Convert whatever the IPAM result was into the current Result type
	result, err := current.NewResultFromResult(conf.PrevResult)
	if err != nil {
	return err
	}

	var contMap current.Interface
	// Find interfaces for name whe know, that of dummy device 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)
	}

	//
	// 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)
	if err != nil {
	return err
	}

	err = ip.ValidateExpectedInterfaceIPs(args.IfName, result.IPs)
	if err != nil {
	return err
	}
	return nil
	}); err != nil {
	return err
	}

	return nil
	}

	func validateCniContainerInterface(intf current.Interface) 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 = netlinksafe.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)
	}

	_, isDummy := link.(*netlink.Dummy)
	if !isDummy {
	return fmt.Errorf("Error: Container interface %s not of type dummy", link.Attrs().Name)
	}

	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)
	}
	}

	if link.Attrs().Flags&net.FlagUp != net.FlagUp {
	return fmt.Errorf("Interface %s is down", intf.Name)
	}

	return nil
	}

	func cmdStatus(args *skel.CmdArgs) error {
	conf := types.NetConf{}
	if err := json.Unmarshal(args.StdinData, &conf); err != nil {
	return fmt.Errorf("failed to load netconf: %w", err)
	}

	if err := ipam.ExecStatus(conf.IPAM.Type, args.StdinData); err != nil {
	return err
	}

	return nil
	}