[CRIU] Creation of tcp sockets suitable for criu restore

[Pavel Emelyanov]

On 01/28/2014 08:20 PM, Zachow Ernst-Friedrich wrote:
> Hi,
> I am currently doing my master's thesis at ETH Zürich and for that I would 
> like to use criu to take snapshots of applications with enabled tcp connections.
>>From what I understand based on the wiki, criu can restore applications if the
> socket gets "locked" during dump and is still locked before we run the restore command.
> However, lets say the socket is not in this locked state anymore (for example I do 
> not stop the application and it closes the socket and terminates or I move the
> snapshot to another system) - how do you create another socket in such a way that
> criu can restore the application for that socket?

If I understood your scenario correctly you want to snapshot the peer as well. Right?

> Does criu provide functionality to create sockets in a locked state before restoring
> an application or is there some kind of best practice how to that?

Not sure I understand the question properly. By locked connection we mean that blocked
with the simple iptables rule. As far as socket re-creation is concerned. Yes, we have 
this functionality in criu/sk-tcp.c file, but it's heavily tied with the rest of criu 
code, so you cannot just call something that will give you such a socket. Some patching
is needed.

Hope that helps.

> Thank you in advance,
> Ernst

Thanks,
Pavel