Use random name to skip name conflict

pkg/nettools/nettools.go

@@ -39,6 +39,7 @@ import (
  "fmt"
  "io/ioutil"
  "log"
+ mrand "math/rand"
  "net"
  "os"
  "os/exec"
@@ -974,6 +975,10 @@ func Teardown(csn *network.ContainerSideNetwork) error {
  return nil
 }
 
+func randomIfaceName() string {
+ return strconv.Itoa(mrand.Int)
+}
+
 // ReconstructVFs iterates over stored PCI addresses, rebinding each
 // corresponding interface to its host driver, changing its MAC address
 // to the stored value and then moving it into the container namespace
@@ -999,14 +1004,19 @@ func ReconstructVFs(csn *network.ContainerSideNetwork, netns ns.NetNS) error {
  if err := netlink.LinkSetHardwareAddr(link, iface.HardwareAddr); err != nil {
  return fmt.Errorf("can't set hwaddr %q on device %q: %v", iface.HardwareAddr, devName, err)
  }
+ tmpName := randomIfaceName()
+ if err := netlink.LinkSetName(link, tmpName); err != nil {
+ return fmt.Errorf("can't set random name %q on interface %q: %v", tmpName, iface.Name, err)
+ }
+ if link, err = netlink.LinByName(tmpName); err != nil {
+ return fmt.Errorf("can't reread link info: %v", err)
+ }
  if err := netlink.LinkSetNsFd(link, int(netns.Fd())); err != nil {
  return fmt.Errorf("can't move link %q to netns %q: %v", iface.Name, netns.Path(), err)
  }
  if err := netns.Do(func(ns.NetNS) error {
- if link.Attrs().Name != iface.Name {
- if err := netlink.LinkSetName(link, iface.Name); err != nil {
- return fmt.Errorf("can't rename device %q to %q: %v", devName, iface.Name, err)
- }
+ if err := netlink.LinkSetName(link, iface.Name); err != nil {
+ return fmt.Errorf("can't rename device %q to %q: %v", devName, iface.Name, err)
  }
  return nil
  }); err != nil {