windows: Fix compilation issue

This commit is to make sure there is no compilication issue
with windows.

Fixes vishvananda#23

Signed-off-by: Tam Mach <sayboras@yahoo.com>

netns.go

@@ -8,73 +8,10 @@
 // as root.
 package netns
 
-import (
-	"fmt"
-
-	"golang.org/x/sys/unix"
-)
-
 // NsHandle is a handle to a network namespace. It can be cast directly
 // to an int and used as a file descriptor.
 type NsHandle int
 
-// Equal determines if two network handles refer to the same network
-// namespace. This is done by comparing the device and inode that the
-// file descriptors point to.
-func (ns NsHandle) Equal(other NsHandle) bool {
-	if ns == other {
-		return true
-	}
-	var s1, s2 unix.Stat_t
-	if err := unix.Fstat(int(ns), &s1); err != nil {
-		return false
-	}
-	if err := unix.Fstat(int(other), &s2); err != nil {
-		return false
-	}
-	return (s1.Dev == s2.Dev) && (s1.Ino == s2.Ino)
-}
-
-// String shows the file descriptor number and its dev and inode.
-func (ns NsHandle) String() string {
-	if ns == -1 {
-		return "NS(None)"
-	}
-	var s unix.Stat_t
-	if err := unix.Fstat(int(ns), &s); err != nil {
-		return fmt.Sprintf("NS(%d: unknown)", ns)
-	}
-	return fmt.Sprintf("NS(%d: %d, %d)", ns, s.Dev, s.Ino)
-}
-
-// UniqueId returns a string which uniquely identifies the namespace
-// associated with the network handle.
-func (ns NsHandle) UniqueId() string {
-	if ns == -1 {
-		return "NS(none)"
-	}
-	var s unix.Stat_t
-	if err := unix.Fstat(int(ns), &s); err != nil {
-		return "NS(unknown)"
-	}
-	return fmt.Sprintf("NS(%d:%d)", s.Dev, s.Ino)
-}
-
-// IsOpen returns true if Close() has not been called.
-func (ns NsHandle) IsOpen() bool {
-	return ns != -1
-}
-
-// Close closes the NsHandle and resets its file descriptor to -1.
-// It is not safe to use an NsHandle after Close() is called.
-func (ns *NsHandle) Close() error {
-	if err := unix.Close(int(*ns)); err != nil {
-		return err
-	}
-	(*ns) = -1
-	return nil
-}
-
 // None gets an empty (closed) NsHandle.
 func None() NsHandle {
 	return NsHandle(-1)

netns_linux.go

@@ -26,6 +26,63 @@ const (
 	bindMountPath = "/run/netns" /* Bind mount path for named netns */
 )
 
+// Equal determines if two network handles refer to the same network
+// namespace. This is done by comparing the device and inode that the
+// file descriptors point to.
+func (ns NsHandle) Equal(other NsHandle) bool {
+	if ns == other {
+		return true
+	}
+	var s1, s2 unix.Stat_t
+	if err := unix.Fstat(int(ns), &s1); err != nil {
+		return false
+	}
+	if err := unix.Fstat(int(other), &s2); err != nil {
+		return false
+	}
+	return (s1.Dev == s2.Dev) && (s1.Ino == s2.Ino)
+}
+
+// String shows the file descriptor number and its dev and inode.
+func (ns NsHandle) String() string {
+	if ns == -1 {
+		return "NS(None)"
+	}
+	var s unix.Stat_t
+	if err := unix.Fstat(int(ns), &s); err != nil {
+		return fmt.Sprintf("NS(%d: unknown)", ns)
+	}
+	return fmt.Sprintf("NS(%d: %d, %d)", ns, s.Dev, s.Ino)
+}
+
+// UniqueId returns a string which uniquely identifies the namespace
+// associated with the network handle.
+func (ns NsHandle) UniqueId() string {
+	if ns == -1 {
+		return "NS(none)"
+	}
+	var s unix.Stat_t
+	if err := unix.Fstat(int(ns), &s); err != nil {
+		return "NS(unknown)"
+	}
+	return fmt.Sprintf("NS(%d:%d)", s.Dev, s.Ino)
+}
+
+// IsOpen returns true if Close() has not been called.
+func (ns NsHandle) IsOpen() bool {
+	return ns != -1
+}
+
+// Close closes the NsHandle and resets its file descriptor to -1.
+// It is not safe to use an NsHandle after Close() is called.
+func (ns *NsHandle) Close() error {
+	if err := unix.Close(int(*ns)); err != nil {
+		return err
+	}
+	(*ns) = -1
+	return nil
+}
+
 // Setns sets namespace using golang.org/x/sys/unix.Setns.
 //
 // Deprecated: Use golang.org/x/sys/unix.Setns instead.

netns_unspecified.go

@@ -1,19 +1,17 @@
+//go:build !linux
 // +build !linux
 
 package netns
 
 import (
 	"errors"
+	"fmt"
 )
 
 var (
 	ErrNotImplemented = errors.New("not implemented")
 )
 
-func Setns(ns NsHandle, nstype int) (err error) {
-	return ErrNotImplemented
-}
-
 func Set(ns NsHandle) (err error) {
 	return ErrNotImplemented
 }