Ben Greear wrote:

Patrick McHardy wrote:

quoted

Eric W. Biederman wrote:
 

quoted

-- The basic design

There will be a network namespace structure that holds the global
variables for a network namespace, making those global variables
per network namespace.

One of those per network namespace global variables will be the
loopback device.  Which means the network namespace a packet resides
in can be found simply by examining the network device or the socket
the packet is traversing.

Either a pointer to this global structure will be passed into
the functions that need to reference per network namespace variables
or a structure that is already passed in (such as the network device)
will be modified to contain a pointer to the network namespace
structure.
   

I believe OpenVZ stores the current namespace somewhere global,
which avoids passing the namespace around. Couldn't you do this
as well?
 

Will we be able to have a single application be in multiple name-spaces?

Application itself can't be in multiple namespaces in both approaches.
But the objects which belong to the application (e.g. sockets opened by an app)
can belong to different namespaces.

Thanks,
Kirill