[stunnel-users] Stunnel 5.44 server side 'exec = pppd' runs second child 'pppd' process after reconnection. Bug?

[Eric Eberhard]

Killing anything will change the PID.  If the PID needs to be constant a zombie is bad news!  Zombies stink!

E

-----Original Message-----
From: Jochen Bern [mailto:Jochen.Bern at binect.de] 
Sent: Wednesday, May 15, 2019 1:42 AM
To: stunnel-users at stunnel.org
Cc: Florian Lohoff <f at zz.de>; Eric Eberhard <flash at vicsmba.com>
Subject: Re: [stunnel-users] Stunnel 5.44 server side 'exec = pppd' runs second child 'pppd' process after reconnection. Bug?

On 05/15/2019 12:22 AM, Florian Lohoff wrote:
> On Tue, May 14, 2019 at 11:30:29AM -0700, Eric Eberhard wrote:
>> That is not a bad idea.  I'd wrap it in a C program so I could check
>> if the pppd is alive and not a zombie.
> 
> pppd is a pretty solid piece of software. Never seen it hang as a
> zombie.

A zombie process is *terminated* and, basically, just a remaining entry
in the kernel's process table. It's not hanging around because of
something its own code did wrong, but because its parent process fails
to "reap" its child (first and foremost, collect its exit code from the
kernel). Killing the parent cleans up zombies because the zombies get
re-parented to the init / systemd process (PID 1), which then does the
reaping.

Regards,
-- 
Jochen Bern
Systemingenieur