[PATCH] bugfix: network namespace & device dummy

[PATCH] bugfix: network namespace & device dummy

[V. Lavrov]

If container has a network device dummyX (with lxc.network.type = phys), then it disappears from the system after you close the container.
The patch returns the device dummyX to the initial network namespace after container is closed.

Signed-off-by: Vitaly Lavrov <lve@guap.ru>
---
diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index bab0158..efa990c 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -160,6 +160,41 @@ static struct rtnl_link_ops dummy_link_ops __read_mostly = {
  module_param(numdummies, int, 0);
  MODULE_PARM_DESC(numdummies, "Number of dummy pseudo devices");

+
+static void __net_exit dummy_net_exit(struct net *net) {
+       struct net_device *dev, *aux;
+       int err;
+
+       if(net == &init_net) return;
+
+       rtnl_lock();
+       for_each_netdev_safe(net, dev, aux) {
+               if(dev->rtnl_link_ops == &dummy_link_ops) {
+                       err = dev_change_net_namespace(dev, &init_net, dev->name);
+                       if(err) {
+                               char fb_name[IFNAMSIZ];
+                               printk (KERN_INFO "%s: dev_change_net_namespace(init_net,%s) err: %d\n",
+                                       __func__,dev->name,err);
+                               snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
+                               err = dev_change_net_namespace(dev, &init_net, dev->name);
+                               if(err)
+                                       printk (KERN_INFO "%s: dev_change_net_namespace(%s,init_net,%s) err: %d\n",
+                                               __func__,dev->name,fb_name,err);
+                               else
+                                       printk (KERN_INFO "%s: %s rename to %s\n",
+                                               __func__,dev->name,fb_name);
+
+                       }
+               }
+       }
+       rtnl_unlock();
+}
+
+static struct pernet_operations __net_initdata dummy_net_ops = {
+       .exit = dummy_net_exit,
+};
+
+
  static int __init dummy_init_one(void)
  {
         struct net_device *dev_dummy;
@@ -184,6 +219,10 @@ static int __init dummy_init_module(void)
  {
         int i, err = 0;

+       err = register_pernet_device(&dummy_net_ops);
+       if(err)
+               return err;
+
         rtnl_lock();
         err = __rtnl_link_register(&dummy_link_ops);

@@ -191,8 +230,10 @@ static int __init dummy_init_module(void)
                 err = dummy_init_one();
                 cond_resched();
         }
-       if (err < 0)
+       if (err < 0) {
                 __rtnl_link_unregister(&dummy_link_ops);
+               unregister_pernet_device(&dummy_net_ops);
+       }
         rtnl_unlock();

         return err;
@@ -201,6 +242,7 @@ static int __init dummy_init_module(void)
  static void __exit dummy_cleanup_module(void)
  {
         rtnl_link_unregister(&dummy_link_ops);
+       unregister_pernet_device(&dummy_net_ops);
  }

  module_init(dummy_init_module);
--

Re: [PATCH] bugfix: network namespace & device dummy

[Vitaly E. Lavrov]

On 17.12.2012 17:01, V. Lavrov wrote:
> If container has a network device dummyX (with lxc.network.type = 
> phys), then it disappears from the system after you close the container.
> The patch returns the device dummyX to the initial network namespace 
> after container is closed.
Do not use this patch. Network devices such as "ifb" and "dummy" can 
re-create command "ip li add ..."

This feature should be documented in the LXC

Re: [PATCH] bugfix: network namespace & device dummy

[David Miller]

From: "V. Lavrov" <lve@guap.ru>
Date: Mon, 17 Dec 2012 17:01:11 +0400

> If container has a network device dummyX (with lxc.network.type =
> phys), then it disappears from the system after you close the
> container.
> The patch returns the device dummyX to the initial network namespace
> after container is closed.
> 
> Signed-off-by: Vitaly Lavrov <lve@guap.ru>

This patch is mangled by your email client.

Do not submit any new patches until you can successfully email
them to yourself, then successfully apply the patch that you
receive in that email.

Because that is exactly what you are asking us to do.