Keeping an idle libssh session open over time

[Magnus Dahler Norling <magnus.dahler.norling@xxxxxxxxx>]

Hi,

I am working on a UI application where the user can click to either pass
some preset remote commands or request data from a file on an openssh
server.

I open a libssh session and connect to the server at the beginning of the
program.

If the user makes a request I open a channel (either a regular channel or
an scp channel) to fulfill the request. I then close the channel again when
it is done.

My problem is that if I leave the session idle for too long without opening
a channel I get a "Socket exception callback: 2 (10053)" when I try to open
a channel again. (The user application is currently running on Windows, but
I will target both Windows and Linux).

I assume this is because the firewall has shut down the connection since it
has been idle for too long.

I have tried to set the ClientAliveInterval and ClientAliveCountMax
settings in etc/ssh/sshd_config at the server.

This does not in itself help. I assume this is because I would have to make
my application receive and respond to that signal. How would I go about
doing that?

Alternatively, is there any other strategy in libssh to keep the session
alive?

I would prefer not to open a new session each time I need to communicate
with the server since it adds noticeable lag.


PS. I call

ssh_is_connected

to see if the session is still alive, but this returns 1, even right before
I get the socket exception when I try to open the channel.

Best Wishes,
Magnus