| [patch 4/4] Network namespaces: playing and debugging [message #3968] |
Mon, 26 June 2006 09:55  |
Andrey Savochkin
Messages: 47
Registered: December 2005
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Member |
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Temporary code to play with network namespaces in the simplest way.
Do
exec 7< /proc/net/net_ns
in your bash shell and you'll get a brand new network namespace.
There you can, for example, do
ip link set lo up
ip addr list
ip addr add 1.2.3.4 dev lo
ping -n 1.2.3.4
Signed-off-by: Andrey Savochkin <saw@swsoft.com>
---
dev.c | 27 ++++++++++++++++++++++++++-
1 files changed, 26 insertions, 1 deletion
--- ./net/core/dev.c.vensdbg Fri Jun 23 11:50:16 2006
+++ ./net/core/dev.c Fri Jun 23 11:50:40 2006
@@ -3444,6 +3444,8 @@ int net_ns_start(void)
if (err)
goto out_register;
put_net_ns(orig_ns);
+ printk(KERN_DEBUG "NET_NS: created new netcontext %p for %s (pid=%d)\n",
+ ns, task->comm, task->tgid);
return 0;
out_register:
@@ -3461,6 +3463,7 @@ EXPORT_SYMBOL(net_ns_start);
void net_ns_free(struct net_namespace *ns)
{
+ printk(KERN_DEBUG "NET_NS: netcontext %p freed\n", ns);
kfree(ns);
}
EXPORT_SYMBOL(net_ns_free);
@@ -3473,8 +3476,13 @@ static void net_ns_destroy(void *data)
ns = data;
push_net_ns(ns, orig_ns);
unregister_netdev(ns->loopback);
+ if (!list_empty(&ns->dev_base)) {
+ printk("NET_NS: BUG: context %p has devices! ref %d\n",
+ ns, atomic_read(&ns->active_ref));
+ pop_net_ns(orig_ns);
+ return;
+ }
ip_fib_struct_fini();
- BUG_ON(!list_empty(&ns->dev_base));
pop_net_ns(orig_ns);
/* drop (hopefully) final reference */
@@ -3483,9 +3491,23 @@ static void net_ns_destroy(void *data)
void net_ns_stop(struct net_namespace *ns)
{
+ printk(KERN_DEBUG "NET_NS: netcontext %p scheduled for stop\n", ns);
execute_in_process_context(net_ns_destroy, ns, &ns->destroy_work);
}
EXPORT_SYMBOL(net_ns_stop);
+
+static int net_ns_open(struct inode *i, struct file *f)
+{
+ return net_ns_start();
+}
+static struct file_operations net_ns_fops = {
+ .open = net_ns_open,
+};
+static int net_ns_init(void)
+{
+ return proc_net_fops_create("net_ns", S_IRWXU, &net_ns_fops)
+ ? 0 : -ENOMEM;
+}
#endif
/*
@@ -3550,6 +3572,9 @@ static int __init net_dev_init(void)
hotcpu_notifier(dev_cpu_callback, 0);
dst_init();
dev_mcast_init();
+#ifdef CONFIG_NET_NS
+ net_ns_init();
+#endif
rc = 0;
out:
return rc;
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| Re: [patch 4/4] Network namespaces: playing and debugging [message #4003 is a reply to message #3968] |
Mon, 26 June 2006 19:34  |
Andrey Savochkin
Messages: 47
Registered: December 2005
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Member |
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On Mon, Jun 26, 2006 at 07:29:57PM +0200, Daniel Lezcano wrote:
> >>>Do
> >>> exec 7< /proc/net/net_ns
> >>>in your bash shell and you'll get a brand new network namespace.
> >>>There you can, for example, do
> >>> ip link set lo up
> >>> ip addr list
> >>> ip addr add 1.2.3.4 dev lo
> >>> ping -n 1.2.3.4
> >>>
>
> Andrey,
>
> I began to play with your patchset. I am able to connect to 127.0.0.1
> from different namespaces. Is it the expected behavior ?
> Furthermore, I am not able to have several programs, running in
> different namespaces, to bind to the same INADDR_ANY:port.
>
> Will these features be included in the second patchset ?
Of course.
This patchset adds namespaces to routing code, which means that
you can define local IP addresses in each namespace independently.
But this first patchset doesn't include namespaces in socket lookup code.
Andrey
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| Re: [patch 4/4] Network namespaces: playing and debugging [message #4011 is a reply to message #3989] |
Mon, 26 June 2006 17:29 |
Daniel Lezcano
Messages: 417
Registered: June 2006
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Senior Member |
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>>>Do
>>> exec 7< /proc/net/net_ns
>>>in your bash shell and you'll get a brand new network namespace.
>>>There you can, for example, do
>>> ip link set lo up
>>> ip addr list
>>> ip addr add 1.2.3.4 dev lo
>>> ping -n 1.2.3.4
>>>
Andrey,
I began to play with your patchset. I am able to connect to 127.0.0.1
from different namespaces. Is it the expected behavior ?
Furthermore, I am not able to have several programs, running in
different namespaces, to bind to the same INADDR_ANY:port.
Will these features be included in the second patchset ?
>>
>>Is it possible to setup a network device to communicate with the outside ?
>
>
> Such device was planned for the second patchset :)
> I perhaps can send the patch tomorrow.
Cool :)
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