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-rw-r--r--vendor/github.com/containernetworking/plugins/pkg/ns/README.md41
-rw-r--r--vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go216
2 files changed, 0 insertions, 257 deletions
diff --git a/vendor/github.com/containernetworking/plugins/pkg/ns/README.md b/vendor/github.com/containernetworking/plugins/pkg/ns/README.md
deleted file mode 100644
index 1e265c7..0000000
--- a/vendor/github.com/containernetworking/plugins/pkg/ns/README.md
+++ /dev/null
@@ -1,41 +0,0 @@
-### Namespaces, Threads, and Go
-On Linux each OS thread can have a different network namespace. Go's thread scheduling model switches goroutines between OS threads based on OS thread load and whether the goroutine would block other goroutines. This can result in a goroutine switching network namespaces without notice and lead to errors in your code.
-
-### Namespace Switching
-Switching namespaces with the `ns.Set()` method is not recommended without additional strategies to prevent unexpected namespace changes when your goroutines switch OS threads.
-
-Go provides the `runtime.LockOSThread()` function to ensure a specific goroutine executes on its current OS thread and prevents any other goroutine from running in that thread until the locked one exits. Careful usage of `LockOSThread()` and goroutines can provide good control over which network namespace a given goroutine executes in.
-
-For example, you cannot rely on the `ns.Set()` namespace being the current namespace after the `Set()` call unless you do two things. First, the goroutine calling `Set()` must have previously called `LockOSThread()`. Second, you must ensure `runtime.UnlockOSThread()` is not called somewhere in-between. You also cannot rely on the initial network namespace remaining the current network namespace if any other code in your program switches namespaces, unless you have already called `LockOSThread()` in that goroutine. Note that `LockOSThread()` prevents the Go scheduler from optimally scheduling goroutines for best performance, so `LockOSThread()` should only be used in small, isolated goroutines that release the lock quickly.
-
-### Do() The Recommended Thing
-The `ns.Do()` method provides **partial** control over network namespaces for you by implementing these strategies. All code dependent on a particular network namespace (including the root namespace) should be wrapped in the `ns.Do()` method to ensure the correct namespace is selected for the duration of your code. For example:
-
-```go
-err = targetNs.Do(func(hostNs ns.NetNS) error {
- dummy := &netlink.Dummy{
- LinkAttrs: netlink.LinkAttrs{
- Name: "dummy0",
- },
- }
- return netlink.LinkAdd(dummy)
-})
-```
-
-Note this requirement to wrap every network call is very onerous - any libraries you call might call out to network services such as DNS, and all such calls need to be protected after you call `ns.Do()`. All goroutines spawned from within the `ns.Do` will not inherit the new namespace. The CNI plugins all exit very soon after calling `ns.Do()` which helps to minimize the problem.
-
-When a new thread is spawned in Linux, it inherits the namespace of its parent. In versions of go **prior to 1.10**, if the runtime spawns a new OS thread, it picks the parent randomly. If the chosen parent thread has been moved to a new namespace (even temporarily), the new OS thread will be permanently "stuck in the wrong namespace", and goroutines will non-deterministically switch namespaces as they are rescheduled.
-
-In short, **there was no safe way to change network namespaces, even temporarily, from within a long-lived, multithreaded Go process**. If you wish to do this, you must use go 1.10 or greater.
-
-
-### Creating network namespaces
-Earlier versions of this library managed namespace creation, but as CNI does not actually utilize this feature (and it was essentially unmaintained), it was removed. If you're writing a container runtime, you should implement namespace management yourself. However, there are some gotchas when doing so, especially around handling `/var/run/netns`. A reasonably correct reference implementation, borrowed from `rkt`, can be found in `pkg/testutils/netns_linux.go` if you're in need of a source of inspiration.
-
-
-### Further Reading
- - https://github.com/golang/go/wiki/LockOSThread
- - http://morsmachine.dk/go-scheduler
- - https://github.com/containernetworking/cni/issues/262
- - https://golang.org/pkg/runtime/
- - https://www.weave.works/blog/linux-namespaces-and-go-don-t-mix
diff --git a/vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go b/vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go
deleted file mode 100644
index 31ad5f6..0000000
--- a/vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go
+++ /dev/null
@@ -1,216 +0,0 @@
-// Copyright 2015-2017 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.
-
-package ns
-
-import (
- "fmt"
- "os"
- "runtime"
- "sync"
- "syscall"
-
- "golang.org/x/sys/unix"
-)
-
-// Returns an object representing the current OS thread's network namespace
-func GetCurrentNS() (NetNS, error) {
- return GetNS(getCurrentThreadNetNSPath())
-}
-
-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())
-}
-
-func (ns *netNS) Close() error {
- if err := ns.errorIfClosed(); err != nil {
- return err
- }
-
- if err := ns.file.Close(); err != nil {
- return fmt.Errorf("Failed to close %q: %v", ns.file.Name(), err)
- }
- ns.closed = true
-
- return nil
-}
-
-func (ns *netNS) Set() error {
- if err := ns.errorIfClosed(); err != nil {
- return err
- }
-
- if err := unix.Setns(int(ns.Fd()), unix.CLONE_NEWNET); err != nil {
- return fmt.Errorf("Error switching to ns %v: %v", ns.file.Name(), err)
- }
-
- return nil
-}
-
-type NetNS interface {
- // Executes the passed closure in this object's network namespace,
- // attempting to restore the original namespace before returning.
- // However, since each OS thread can have a different network namespace,
- // and Go's thread scheduling is highly variable, callers cannot
- // guarantee any specific namespace is set unless operations that
- // require that namespace are wrapped with Do(). Also, no code called
- // from Do() should call runtime.UnlockOSThread(), or the risk
- // of executing code in an incorrect namespace will be greater. See
- // https://github.com/golang/go/wiki/LockOSThread for further details.
- Do(toRun func(NetNS) error) error
-
- // Sets the current network namespace to this object's network namespace.
- // Note that since Go's thread scheduling is highly variable, callers
- // cannot guarantee the requested namespace will be the current namespace
- // after this function is called; to ensure this wrap operations that
- // require the namespace with Do() instead.
- Set() error
-
- // Returns the filesystem path representing this object's network namespace
- Path() string
-
- // Returns a file descriptor representing this object's network namespace
- Fd() uintptr
-
- // Cleans up this instance of the network namespace; if this instance
- // is the last user the namespace will be destroyed
- Close() error
-}
-
-type netNS struct {
- file *os.File
- closed bool
-}
-
-// netNS implements the NetNS interface
-var _ NetNS = &netNS{}
-
-const (
- // https://github.com/torvalds/linux/blob/master/include/uapi/linux/magic.h
- NSFS_MAGIC = 0x6e736673
- PROCFS_MAGIC = 0x9fa0
-)
-
-type NSPathNotExistErr struct{ msg string }
-
-func (e NSPathNotExistErr) Error() string { return e.msg }
-
-type NSPathNotNSErr struct{ msg string }
-
-func (e NSPathNotNSErr) Error() string { return e.msg }
-
-func IsNSorErr(nspath string) error {
- stat := syscall.Statfs_t{}
- if err := syscall.Statfs(nspath, &stat); err != nil {
- if os.IsNotExist(err) {
- err = NSPathNotExistErr{msg: fmt.Sprintf("failed to Statfs %q: %v", nspath, err)}
- } else {
- err = fmt.Errorf("failed to Statfs %q: %v", nspath, err)
- }
- return err
- }
-
- switch stat.Type {
- case PROCFS_MAGIC, NSFS_MAGIC:
- return nil
- default:
- return NSPathNotNSErr{msg: fmt.Sprintf("unknown FS magic on %q: %x", nspath, stat.Type)}
- }
-}
-
-// Returns an object representing the namespace referred to by @path
-func GetNS(nspath string) (NetNS, error) {
- err := IsNSorErr(nspath)
- if err != nil {
- return nil, err
- }
-
- fd, err := os.Open(nspath)
- if err != nil {
- return nil, err
- }
-
- return &netNS{file: fd}, nil
-}
-
-func (ns *netNS) Path() string {
- return ns.file.Name()
-}
-
-func (ns *netNS) Fd() uintptr {
- return ns.file.Fd()
-}
-
-func (ns *netNS) errorIfClosed() error {
- if ns.closed {
- return fmt.Errorf("%q has already been closed", ns.file.Name())
- }
- return nil
-}
-
-func (ns *netNS) Do(toRun func(NetNS) error) error {
- if err := ns.errorIfClosed(); err != nil {
- return err
- }
-
- containedCall := func(hostNS NetNS) error {
- threadNS, err := GetCurrentNS()
- if err != nil {
- return fmt.Errorf("failed to open current netns: %v", err)
- }
- defer threadNS.Close()
-
- // switch to target namespace
- if err = ns.Set(); err != nil {
- return fmt.Errorf("error switching to ns %v: %v", ns.file.Name(), err)
- }
- defer threadNS.Set() // switch back
-
- return toRun(hostNS)
- }
-
- // save a handle to current network namespace
- hostNS, err := GetCurrentNS()
- if err != nil {
- return fmt.Errorf("Failed to open current namespace: %v", err)
- }
- defer hostNS.Close()
-
- var wg sync.WaitGroup
- wg.Add(1)
-
- var innerError error
- go func() {
- defer wg.Done()
- runtime.LockOSThread()
- innerError = containedCall(hostNS)
- }()
- wg.Wait()
-
- return innerError
-}
-
-// WithNetNSPath executes the passed closure under the given network
-// namespace, restoring the original namespace afterwards.
-func WithNetNSPath(nspath string, toRun func(NetNS) error) error {
- ns, err := GetNS(nspath)
- if err != nil {
- return err
- }
- defer ns.Close()
- return ns.Do(toRun)
-}