128 lines
3.3 KiB
Go
128 lines
3.3 KiB
Go
/*
|
|
Copyright 2017 The Kubernetes 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 sandbox
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"os"
|
|
"sync"
|
|
|
|
cnins "github.com/containernetworking/plugins/pkg/ns"
|
|
"github.com/docker/docker/pkg/mount"
|
|
"github.com/docker/docker/pkg/symlink"
|
|
"golang.org/x/sys/unix"
|
|
)
|
|
|
|
// ErrClosedNetNS is the error returned when network namespace is closed.
|
|
var ErrClosedNetNS = errors.New("network namespace is closed")
|
|
|
|
// NetNS holds network namespace for sandbox
|
|
type NetNS struct {
|
|
sync.Mutex
|
|
ns cnins.NetNS
|
|
closed bool
|
|
restored bool
|
|
}
|
|
|
|
// NewNetNS creates a network namespace for the sandbox
|
|
func NewNetNS() (*NetNS, error) {
|
|
netns, err := cnins.NewNS()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to setup network namespace %v", err)
|
|
}
|
|
n := new(NetNS)
|
|
n.ns = netns
|
|
return n, nil
|
|
}
|
|
|
|
// LoadNetNS loads existing network namespace. It returns ErrClosedNetNS
|
|
// if the network namespace has already been closed.
|
|
func LoadNetNS(path string) (*NetNS, error) {
|
|
ns, err := cnins.GetNS(path)
|
|
if err != nil {
|
|
if _, ok := err.(cnins.NSPathNotExistErr); ok {
|
|
return nil, ErrClosedNetNS
|
|
}
|
|
if _, ok := err.(cnins.NSPathNotNSErr); ok {
|
|
// Do best effort cleanup.
|
|
os.RemoveAll(path) // nolint: errcheck
|
|
return nil, ErrClosedNetNS
|
|
}
|
|
return nil, fmt.Errorf("failed to load network namespace %v", err)
|
|
}
|
|
return &NetNS{ns: ns, restored: true}, nil
|
|
}
|
|
|
|
// Remove removes network namepace if it exists and not closed. Remove is idempotent,
|
|
// meaning it might be invoked multiple times and provides consistent result.
|
|
func (n *NetNS) Remove() error {
|
|
n.Lock()
|
|
defer n.Unlock()
|
|
if !n.closed {
|
|
err := n.ns.Close()
|
|
if err != nil {
|
|
return fmt.Errorf("failed to close network namespace: %v", err)
|
|
}
|
|
n.closed = true
|
|
}
|
|
if n.restored {
|
|
path := n.ns.Path()
|
|
// TODO(random-liu): Add util function for unmount.
|
|
// Check netns existence.
|
|
if _, err := os.Stat(path); err != nil {
|
|
if os.IsNotExist(err) {
|
|
return nil
|
|
}
|
|
return fmt.Errorf("failed to stat netns: %v", err)
|
|
}
|
|
path, err := symlink.FollowSymlinkInScope(path, "/")
|
|
if err != nil {
|
|
return fmt.Errorf("failed to follow symlink: %v", err)
|
|
}
|
|
mounted, err := mount.Mounted(path)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to check netns mounted: %v", err)
|
|
}
|
|
if mounted {
|
|
err := unix.Unmount(path, unix.MNT_DETACH)
|
|
if err != nil && !os.IsNotExist(err) {
|
|
return fmt.Errorf("failed to umount netns: %v", err)
|
|
}
|
|
}
|
|
if err := os.RemoveAll(path); err != nil {
|
|
return fmt.Errorf("failed to remove netns: %v", err)
|
|
}
|
|
n.restored = false
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Closed checks whether the network namespace has been closed.
|
|
func (n *NetNS) Closed() bool {
|
|
n.Lock()
|
|
defer n.Unlock()
|
|
return n.closed && !n.restored
|
|
}
|
|
|
|
// GetPath returns network namespace path for sandbox container
|
|
func (n *NetNS) GetPath() string {
|
|
n.Lock()
|
|
defer n.Unlock()
|
|
return n.ns.Path()
|
|
}
|