multus-cni/pkg/netutils/netutils.go
Miguel Duarte Barroso 12df5bda72
run gofmt on the code (#772)
Signed-off-by: Miguel Duarte Barroso <mdbarroso@redhat.com>
2022-01-05 01:33:58 +09:00

406 lines
11 KiB
Go

// Copyright (c) 2019 Multus 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 netutils
import (
"encoding/json"
"fmt"
"io/ioutil"
"net"
"path/filepath"
"github.com/containernetworking/cni/libcni"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/plugins/pkg/ns"
"github.com/vishvananda/netlink"
"gopkg.in/k8snetworkplumbingwg/multus-cni.v3/pkg/logging"
)
// DeleteDefaultGW removes the default gateway from marked interfaces.
func DeleteDefaultGW(args *skel.CmdArgs, ifName string) error {
netns, err := ns.GetNS(args.Netns)
if err != nil {
return logging.Errorf("DeleteDefaultGW: Error getting namespace %v", err)
}
defer netns.Close()
err = netns.Do(func(_ ns.NetNS) error {
var err error
link, _ := netlink.LinkByName(ifName)
routes, _ := netlink.RouteList(link, netlink.FAMILY_ALL)
for _, nlroute := range routes {
if nlroute.Dst == nil {
err = netlink.RouteDel(&nlroute)
}
}
return err
})
return err
}
// SetDefaultGW adds a default gateway on a specific interface
func SetDefaultGW(args *skel.CmdArgs, ifName string, gateways []net.IP) error {
// This ensures we're acting within the net namespace for the pod.
netns, err := ns.GetNS(args.Netns)
if err != nil {
return logging.Errorf("SetDefaultGW: Error getting namespace %v", err)
}
defer netns.Close()
// Do this within the net namespace.
err = netns.Do(func(_ ns.NetNS) error {
var err error
// Pick up the link info as we need the index.
link, err := netlink.LinkByName(ifName)
if err != nil {
return logging.Errorf("SetDefaultGW: Error getting link %v", err)
}
// Cycle through all the desired gateways.
for _, gw := range gateways {
// Create a new route (note: dst is nil by default)
logging.Debugf("SetDefaultGW: Adding default route on %v (index: %v) to %v", ifName, link.Attrs().Index, gw)
newDefaultRoute := netlink.Route{
LinkIndex: link.Attrs().Index,
Gw: gw,
}
// Perform the creation of the default route....
err = netlink.RouteAdd(&newDefaultRoute)
if err != nil {
logging.Errorf("SetDefaultGW: Error adding route: %v", err)
}
}
return err
})
return err
}
// DeleteDefaultGWCache updates libcni cache to remove default gateway routes in result
func DeleteDefaultGWCache(cacheDir string, rt *libcni.RuntimeConf, netName string, ifName string, ipv4, ipv6 bool) error {
cacheFile := filepath.Join(cacheDir, "results", fmt.Sprintf("%s-%s-%s", netName, rt.ContainerID, rt.IfName))
cache, err := ioutil.ReadFile(cacheFile)
if err != nil {
return err
}
logging.Debugf("DeleteDefaultGWCache: update cache to delete GW from: %s", string(cache))
newCache, err := deleteDefaultGWCacheBytes(cache, ipv4, ipv6)
if err != nil {
return err
}
logging.Debugf("DeleteDefaultGWCache: update cache to delete GW: %s", string(newCache))
return ioutil.WriteFile(cacheFile, newCache, 0600)
}
func deleteDefaultGWCacheBytes(cacheFile []byte, ipv4, ipv6 bool) ([]byte, error) {
var cachedInfo map[string]interface{}
if err := json.Unmarshal(cacheFile, &cachedInfo); err != nil {
return nil, err
}
// try to get result
_, ok := cachedInfo["result"]
if !ok {
return nil, fmt.Errorf("cannot get result from cache")
}
resultJSON, ok := cachedInfo["result"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong result type: %v", cachedInfo["result"])
}
newResult, err := deleteDefaultGWResult(resultJSON, ipv4, ipv6)
if err != nil {
return nil, err
}
cachedInfo["result"] = newResult
newCache, err := json.Marshal(cachedInfo)
if err != nil {
return nil, fmt.Errorf("failed to encode json: %v", err)
}
return newCache, nil
}
func deleteDefaultGWResultRoutes(routes []interface{}, dstGW string) ([]interface{}, error) {
for i, r := range routes {
route, ok := r.(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong route format: %v", r)
}
_, ok = route["dst"]
if ok {
dst, ok := route["dst"].(string)
if !ok {
return nil, fmt.Errorf("wrong dst format: %v", route["dst"])
}
if dst == dstGW {
routes = append(routes[:i], routes[i+1:]...)
}
}
}
return routes, nil
}
func deleteDefaultGWResult(result map[string]interface{}, ipv4, ipv6 bool) (map[string]interface{}, error) {
// try to get cniVersion from result
_, ok := result["cniVersion"]
if !ok {
// fallback to processing result for old cni version(0.1.0/0.2.0)
return deleteDefaultGWResult020(result, ipv4, ipv6)
}
cniVersion, ok := result["cniVersion"].(string)
if !ok {
return nil, fmt.Errorf("wrong cniVersion format: %v", result["cniVersion"])
}
if cniVersion == "0.1.0" || cniVersion == "0.2.0" {
// fallback to processing result for old cni version(0.1.0/0.2.0)
return deleteDefaultGWResult020(result, ipv4, ipv6)
}
if cniVersion != "0.3.0" && cniVersion != "0.3.1" && cniVersion != "0.4.0" && cniVersion != "1.0.0" {
return nil, fmt.Errorf("not supported version: %s", cniVersion)
}
_, ok = result["routes"]
if !ok {
// No route in result, hence we do nothing
return result, nil
}
routes, ok := result["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong routes format: %v", result["routes"])
}
var err error
// delete IPv4 default routes
if ipv4 {
routes, err = deleteDefaultGWResultRoutes(routes, "0.0.0.0/0")
if err != nil {
return nil, err
}
}
if ipv6 {
routes, err = deleteDefaultGWResultRoutes(routes, "::0/0")
if err != nil {
return nil, err
}
}
result["routes"] = routes
return result, nil
}
func deleteDefaultGWResult020(result map[string]interface{}, ipv4, ipv6 bool) (map[string]interface{}, error) {
var err error
if ipv4 {
_, ok := result["ip4"]
if ok {
ip4, ok := result["ip4"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip4 format: %v", result["ip4"])
}
_, ok = ip4["routes"]
if ok {
routes, ok := ip4["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip4 routes format: %v", ip4["routes"])
}
routes, err = deleteDefaultGWResultRoutes(routes, "0.0.0.0/0")
if err != nil {
return nil, err
}
ip4["routes"] = routes
}
}
}
if ipv6 {
_, ok := result["ip6"]
if ok {
ip6, ok := result["ip6"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip6 format: %v", result["ip6"])
}
_, ok = ip6["routes"]
if ok {
routes, ok := ip6["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip6 routes format: %v", ip6["routes"])
}
routes, err = deleteDefaultGWResultRoutes(routes, "::0/0")
if err != nil {
return nil, err
}
ip6["routes"] = routes
}
}
}
return result, nil
}
// AddDefaultGWCache updates libcni cache to add default gateway result
func AddDefaultGWCache(cacheDir string, rt *libcni.RuntimeConf, netName string, ifName string, gw []net.IP) error {
cacheFile := filepath.Join(cacheDir, "results", fmt.Sprintf("%s-%s-%s", netName, rt.ContainerID, rt.IfName))
cache, err := ioutil.ReadFile(cacheFile)
if err != nil {
return err
}
logging.Debugf("AddDefaultGWCache: update cache to add GW from: %s", string(cache))
newCache, err := addDefaultGWCacheBytes(cache, gw)
if err != nil {
return err
}
logging.Debugf("AddDefaultGWCache: update cache to add GW: %s", string(newCache))
return ioutil.WriteFile(cacheFile, newCache, 0600)
}
func addDefaultGWCacheBytes(cacheFile []byte, gw []net.IP) ([]byte, error) {
var cachedInfo map[string]interface{}
if err := json.Unmarshal(cacheFile, &cachedInfo); err != nil {
return nil, err
}
// try to get result
_, ok := cachedInfo["result"]
if !ok {
return nil, fmt.Errorf("cannot get result from cache")
}
resultJSON, ok := cachedInfo["result"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong result type: %v", cachedInfo["result"])
}
newResult, err := addDefaultGWResult(resultJSON, gw)
if err != nil {
return nil, err
}
cachedInfo["result"] = newResult
newCache, err := json.Marshal(cachedInfo)
if err != nil {
return nil, fmt.Errorf("failed to encode json: %v", err)
}
return newCache, nil
}
func addDefaultGWResult(result map[string]interface{}, gw []net.IP) (map[string]interface{}, error) {
// try to get cniVersion from result
_, ok := result["cniVersion"]
if !ok {
// fallback to processing result for old cni version(0.1.0/0.2.0)
return addDefaultGWResult020(result, gw)
}
cniVersion, ok := result["cniVersion"].(string)
if !ok {
return nil, fmt.Errorf("wrong cniVersion format: %v", result["cniVersion"])
}
if cniVersion == "0.1.0" || cniVersion == "0.2.0" {
// fallback to processing result for old cni version(0.1.0/0.2.0)
return addDefaultGWResult020(result, gw)
}
if cniVersion != "0.3.0" && cniVersion != "0.3.1" && cniVersion != "0.4.0" && cniVersion != "1.0.0" {
return nil, fmt.Errorf("not supported version: %s", cniVersion)
}
routes := []interface{}{}
_, ok = result["routes"]
if ok {
routes, ok = result["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong routes format: %v", result["routes"])
}
}
for _, g := range gw {
dst := "0.0.0.0/0"
if g.To4() == nil {
dst = "::0/0"
}
routes = append(routes, map[string]string{
"dst": dst,
"gw": g.String(),
})
}
result["routes"] = routes
return result, nil
}
func addDefaultGWResult020(result map[string]interface{}, gw []net.IP) (map[string]interface{}, error) {
for _, g := range gw {
if g.To4() != nil {
_, ok := result["ip4"]
if ok {
ip4, ok := result["ip4"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip4 format: %v", result["ip4"])
}
routes := []interface{}{}
_, ok = ip4["routes"]
if ok {
routes, ok = ip4["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip4 routes format: %v", ip4["routes"])
}
}
ip4["routes"] = append(routes, map[string]string{
"dst": "0.0.0.0/0",
"gw": g.String(),
})
}
} else {
_, ok := result["ip6"]
if ok {
ip6, ok := result["ip6"].(map[string]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip6 format: %v", result["ip4"])
}
routes := []interface{}{}
_, ok = ip6["routes"]
if ok {
routes, ok = ip6["routes"].([]interface{})
if !ok {
return nil, fmt.Errorf("wrong ip6 routes format: %v", ip6["routes"])
}
}
ip6["routes"] = append(routes, map[string]string{
"dst": "::/0",
"gw": g.String(),
})
}
}
}
return result, nil
}