diff options
Diffstat (limited to 'vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go')
-rw-r--r-- | vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go | 216 |
1 files changed, 0 insertions, 216 deletions
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) -} |