[CRIU] C/R a listening socket with backlog connections

[Andrei Vagin]

On Wed, Oct 25, 2017 at 02:22:35PM -0400, Dan Nanni wrote:
> Hi,
> 
> I noticed that criu does not support C/R a listening socket with non-empty
> backlog connections.  It simply drops those connections with
> "--skip-in-flight" option.
> 
> I am curious to know what is the challenge that prevents criu from fully
> supporting listening sockets with backlog connections.

The problem is that the kernel doesn't have an interface to get backlog
connections without dequeueing them from a listening socket. But when we
a dumping a socket, we can't change its state, because in a error cases,
processes have to be resumed.

And the kernel doesn't have an interface to restore backlog connections.

If you have time and have a wish to extend the kernel for this task, we
can continue this discussions with more details.

Thanks,
Andrei

> 
> -Dan

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