[Devel] [PATCH 10/12] L2 network namespace: playing with pass-through device

[Daniel Lezcano]

Dmitry Mishin wrote:
> On Tuesday 12 December 2006 16:59, Daniel Lezcano wrote:
>> Dmitry Mishin wrote:
>>> Temporary code to debug and play with pass-through device.
>>> Create device pair by
>>> 	modprobe veth
>>>         echo 'add veth1 0:1:2:3:4:1 eth0 0:1:2:3:4:2' >/proc/net/veth_ctl
>>> and your shell will appear into a new namespace with `eth0' device.
>>> Configure device in this namespace
>>>         ip l s eth0 up
>>>         ip a a 1.2.3.4/24 dev eth0
>>> and in the root namespace
>>>         ip l s veth1 up
>>>         ip a a 1.2.3.1/24 dev veth1
>>> to establish a communication channel between root namespace and the newly
>>> created one.
>>>
>>> Code is done by Andrey Savochkin and ported by me over Cedric'c patchset
>>>
>>> Signed-off-by: Dmitry Mishin <dim at openvz.org>
>>>
>> [ ... ]
>>
>>> --- linux-2.6.19-rc6-mm2.orig/include/linux/net_namespace.h
>>> +++ linux-2.6.19-rc6-mm2/include/linux/net_namespace.h
>>> @@ -24,6 +24,9 @@ struct net_namespace {
>>>  	int			fib4_trie_last_dflt;
>>>  #endif
>>>  	unsigned int		hash;
>>> +	struct net_namespace	*parent;
>>> +	struct list_head	child_list, sibling_list;
>>> +	unsigned int		id;
>>>  };
>> Why do yo need to have a child list and sibling list ?
> Because of the level2<->level3 hierarchy, for example.

This hierarchy doesn't exist with ns->parent ? Do you have an example 
when the hierarchy should be used ? I mean when we need to browse from 
l2 -> l3 ?