origin dnsname commit

Signed-off-by: baude <bbaude@redhat.com>

1 files changed, 216 insertions, 0 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
new file mode 100644
index 0000000..31ad5f6
--- /dev/null
+++ b/vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go
@@ -0,0 +1,216 @@
+// 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)
+}