summaryrefslogtreecommitdiff
path: root/pkg/netns/netns_linux.go
diff options
context:
space:
mode:
authorPaul Holzinger <pholzing@redhat.com>2022-01-07 14:34:45 +0100
committerPaul Holzinger <pholzing@redhat.com>2022-01-12 17:40:24 +0100
commit918890a4d6f91a6f4bf844427f7e485676cc117e (patch)
treeb82c017570e97d27c4c62aecb69832a27f33e482 /pkg/netns/netns_linux.go
parent0151e10b627fbfb82b7d633f3fc9703678ed4eaf (diff)
downloadpodman-918890a4d6f91a6f4bf844427f7e485676cc117e.tar.gz
podman-918890a4d6f91a6f4bf844427f7e485676cc117e.tar.bz2
podman-918890a4d6f91a6f4bf844427f7e485676cc117e.zip
use netns package from c/common
The netns package was moved to c/common so we should use this and remove the package from podman. Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Diffstat (limited to 'pkg/netns/netns_linux.go')
-rw-r--r--pkg/netns/netns_linux.go210
1 files changed, 0 insertions, 210 deletions
diff --git a/pkg/netns/netns_linux.go b/pkg/netns/netns_linux.go
deleted file mode 100644
index 3e6e668b5..000000000
--- a/pkg/netns/netns_linux.go
+++ /dev/null
@@ -1,210 +0,0 @@
-// Copyright 2018 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
-//
-// https://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 file was originally a part of the containernetworking/plugins
-// repository.
-// It was copied here and modified for local use by the libpod maintainers.
-
-package netns
-
-import (
- "crypto/rand"
- "fmt"
- "os"
- "path"
- "path/filepath"
- "runtime"
- "strings"
- "sync"
-
- "github.com/containernetworking/plugins/pkg/ns"
- "github.com/containers/podman/v3/pkg/rootless"
- "github.com/containers/podman/v3/pkg/util"
- "github.com/sirupsen/logrus"
- "golang.org/x/sys/unix"
-)
-
-// GetNSRunDir returns the dir of where to create the netNS. When running
-// rootless, it needs to be at a location writable by user.
-func GetNSRunDir() (string, error) {
- if rootless.IsRootless() {
- rootlessDir, err := util.GetRuntimeDir()
- if err != nil {
- return "", err
- }
- return filepath.Join(rootlessDir, "netns"), nil
- }
- return "/run/netns", nil
-}
-
-// NewNS creates a new persistent (bind-mounted) network namespace and returns
-// an object representing that namespace, without switching to it.
-func NewNS() (ns.NetNS, error) {
- b := make([]byte, 16)
- _, err := rand.Reader.Read(b)
- if err != nil {
- return nil, fmt.Errorf("failed to generate random netns name: %v", err)
- }
- nsName := fmt.Sprintf("cni-%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
- return NewNSWithName(nsName)
-}
-
-// NewNSWithName creates a new persistent (bind-mounted) network namespace and returns
-// an object representing that namespace, without switching to it.
-func NewNSWithName(name string) (ns.NetNS, error) {
- nsRunDir, err := GetNSRunDir()
- if err != nil {
- return nil, err
- }
-
- // Create the directory for mounting network namespaces
- // This needs to be a shared mountpoint in case it is mounted in to
- // other namespaces (containers)
- err = os.MkdirAll(nsRunDir, 0755)
- if err != nil {
- return nil, err
- }
-
- // Remount the namespace directory shared. This will fail if it is not
- // already a mountpoint, so bind-mount it on to itself to "upgrade" it
- // to a mountpoint.
- err = unix.Mount("", nsRunDir, "none", unix.MS_SHARED|unix.MS_REC, "")
- if err != nil {
- if err != unix.EINVAL {
- return nil, fmt.Errorf("mount --make-rshared %s failed: %q", nsRunDir, err)
- }
-
- // Recursively remount /run/netns on itself. The recursive flag is
- // so that any existing netns bindmounts are carried over.
- err = unix.Mount(nsRunDir, nsRunDir, "none", unix.MS_BIND|unix.MS_REC, "")
- if err != nil {
- return nil, fmt.Errorf("mount --rbind %s %s failed: %q", nsRunDir, nsRunDir, err)
- }
-
- // Now we can make it shared
- err = unix.Mount("", nsRunDir, "none", unix.MS_SHARED|unix.MS_REC, "")
- if err != nil {
- return nil, fmt.Errorf("mount --make-rshared %s failed: %q", nsRunDir, err)
- }
- }
-
- // create an empty file at the mount point
- nsPath := path.Join(nsRunDir, name)
- mountPointFd, err := os.Create(nsPath)
- if err != nil {
- return nil, err
- }
- if err := mountPointFd.Close(); err != nil {
- return nil, err
- }
-
- // Ensure the mount point is cleaned up on errors; if the namespace
- // was successfully mounted this will have no effect because the file
- // is in-use
- defer func() {
- _ = os.RemoveAll(nsPath)
- }()
-
- var wg sync.WaitGroup
- wg.Add(1)
-
- // do namespace work in a dedicated goroutine, so that we can safely
- // Lock/Unlock OSThread without upsetting the lock/unlock state of
- // the caller of this function
- go (func() {
- defer wg.Done()
- runtime.LockOSThread()
- // Don't unlock. By not unlocking, golang will kill the OS thread when the
- // goroutine is done (for go1.10+)
-
- threadNsPath := getCurrentThreadNetNSPath()
-
- var origNS ns.NetNS
- origNS, err = ns.GetNS(threadNsPath)
- if err != nil {
- logrus.Warnf("Cannot open current network namespace %s: %q", threadNsPath, err)
- return
- }
- defer func() {
- if err := origNS.Close(); err != nil {
- logrus.Errorf("Unable to close namespace: %q", err)
- }
- }()
-
- // create a new netns on the current thread
- err = unix.Unshare(unix.CLONE_NEWNET)
- if err != nil {
- logrus.Warnf("Cannot create a new network namespace: %q", err)
- return
- }
-
- // Put this thread back to the orig ns, since it might get reused (pre go1.10)
- defer func() {
- if err := origNS.Set(); err != nil {
- if rootless.IsRootless() && strings.Contains(err.Error(), "operation not permitted") {
- // When running in rootless mode it will fail to re-join
- // the network namespace owned by root on the host.
- return
- }
- logrus.Warnf("Unable to reset namespace: %q", err)
- }
- }()
-
- // bind mount the netns from the current thread (from /proc) onto the
- // mount point. This causes the namespace to persist, even when there
- // are no threads in the ns. Make this a shared mount; it needs to be
- // back-propagated to the host
- err = unix.Mount(threadNsPath, nsPath, "none", unix.MS_BIND|unix.MS_SHARED|unix.MS_REC, "")
- if err != nil {
- err = fmt.Errorf("failed to bind mount ns at %s: %v", nsPath, err)
- }
- })()
- wg.Wait()
-
- if err != nil {
- return nil, fmt.Errorf("failed to create namespace: %v", err)
- }
-
- return ns.GetNS(nsPath)
-}
-
-// UnmountNS unmounts the NS held by the netns object
-func UnmountNS(ns ns.NetNS) error {
- nsRunDir, err := GetNSRunDir()
- if err != nil {
- return err
- }
-
- nsPath := ns.Path()
- // Only unmount if it's been bind-mounted (don't touch namespaces in /proc...)
- if strings.HasPrefix(nsPath, nsRunDir) {
- if err := unix.Unmount(nsPath, unix.MNT_DETACH); err != nil {
- return fmt.Errorf("failed to unmount NS: at %s: %v", nsPath, err)
- }
-
- if err := os.Remove(nsPath); err != nil {
- return fmt.Errorf("failed to remove ns path %s: %v", nsPath, err)
- }
- }
-
- return nil
-}
-
-// getCurrentThreadNetNSPath copied from pkg/ns
-func getCurrentThreadNetNSPath() string {
- // /proc/self/ns/net returns the namespace of the main thread, not
- // of whatever thread this goroutine is running on. Make sure we
- // use the thread's net namespace since the thread is switching around
- return fmt.Sprintf("/proc/%d/task/%d/ns/net", os.Getpid(), unix.Gettid())
-}