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// Copyright 2016 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.
// This is a "meta-plugin". It reads in its own netconf, it does not create
// any network interface but just changes the network sysctl.
package main
import (
"encoding/json"
"fmt"
"net"
"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"
bv "github.com/containernetworking/plugins/pkg/utils/buildversion"
)
// FirewallNetConf represents the firewall configuration.
type FirewallNetConf struct {
types.NetConf
// Backend is the firewall type to add rules to. Allowed values are
// 'iptables' and 'firewalld'.
Backend string `json:"backend"`
// IptablesAdminChainName is an optional name to use instead of the default
// admin rules override chain name that includes the interface name.
IptablesAdminChainName string `json:"iptablesAdminChainName,omitempty"`
// FirewalldZone is an optional firewalld zone to place the interface into. If
// the firewalld backend is used but the zone is not given, it defaults
// to 'trusted'
FirewalldZone string `json:"firewalldZone,omitempty"`
}
type FirewallBackend interface {
Add(*FirewallNetConf, *current.Result) error
Del(*FirewallNetConf, *current.Result) error
Check(*FirewallNetConf, *current.Result) error
}
func ipString(ip net.IPNet) string {
if ip.IP.To4() == nil {
return ip.IP.String() + "/128"
}
return ip.IP.String() + "/32"
}
func parseConf(data []byte) (*FirewallNetConf, *current.Result, error) {
conf := FirewallNetConf{}
if err := json.Unmarshal(data, &conf); err != nil {
return nil, nil, fmt.Errorf("failed to load netconf: %v", err)
}
// Default the firewalld zone to trusted
if conf.FirewalldZone == "" {
conf.FirewalldZone = "trusted"
}
// Parse previous result.
if conf.RawPrevResult == nil {
// return early if there was no previous result, which is allowed for DEL calls
return &conf, ¤t.Result{}, nil
}
// Parse previous result.
var result *current.Result
var err error
if err = version.ParsePrevResult(&conf.NetConf); err != nil {
return nil, nil, fmt.Errorf("could not parse prevResult: %v", err)
}
result, err = current.NewResultFromResult(conf.PrevResult)
if err != nil {
return nil, nil, fmt.Errorf("could not convert result to current version: %v", err)
}
return &conf, result, nil
}
func getBackend(conf *FirewallNetConf) (FirewallBackend, error) {
switch conf.Backend {
case "iptables":
return newIptablesBackend(conf)
case "firewalld":
return newFirewalldBackend(conf)
}
// Default to firewalld if it's running
if isFirewalldRunning() {
return newFirewalldBackend(conf)
}
// Otherwise iptables
return newIptablesBackend(conf)
}
func cmdAdd(args *skel.CmdArgs) error {
conf, result, err := parseConf(args.StdinData)
if err != nil {
return err
}
if conf.PrevResult == nil {
return fmt.Errorf("missing prevResult from earlier plugin")
}
backend, err := getBackend(conf)
if err != nil {
return err
}
if err := backend.Add(conf, result); err != nil {
return err
}
if result == nil {
result = ¤t.Result{}
}
return types.PrintResult(result, conf.CNIVersion)
}
func cmdDel(args *skel.CmdArgs) error {
conf, result, err := parseConf(args.StdinData)
if err != nil {
return err
}
backend, err := getBackend(conf)
if err != nil {
return err
}
// Runtime errors are ignored
if err := backend.Del(conf, result); err != nil {
return err
}
return nil
}
func main() {
skel.PluginMain(cmdAdd, cmdCheck, cmdDel, version.PluginSupports("0.4.0"), bv.BuildString("firewall"))
}
func cmdCheck(args *skel.CmdArgs) error {
conf, result, err := parseConf(args.StdinData)
if err != nil {
return err
}
// Ensure we have previous result.
if conf.PrevResult == nil {
return fmt.Errorf("missing prevResult from earlier plugin")
}
backend, err := getBackend(conf)
if err != nil {
return err
}
if err := backend.Check(conf, result); err != nil {
return err
}
return nil
}
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