linux-kernel - Re: SIGHUP on connect

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 29 Oct 2020 21:48:38 +0100
From:   Bernd Petrovitsch <bernd@...rovitsch.priv.at>
To:     "Michael J. Baars" <mjbaars1977.linux-kernel@...erfiber.eu>,
        linux-kernel@...r.kernel.org
Subject: Re: SIGHUP on connect

Hi all!

On 29/10/2020 14:10, Michael J. Baars wrote:
[...] 
> According to manual page socket(7), SO_REUSEADDR allows for local addresses to be reused for binding. I've tested this socket option with the WAN address, it
> appears the problem is solved for both local and non-local connections.

Yup.

> I also found the the SO_LINGER socket option to be useful in some way. By default, SO_LINGER is set to 0, so you would think that lingering connections were out
> of the question. However, an enabled linger with a l_onoff = 1 and a l_linger = 0 seems to work a lot better than a disabled linger with a l_onoff = 0 and a
> l_linger = 0.
> 
> Which option would you use?

I never used SO_LINGER before.

>From the description in `man 7 socket`, active SO_LINGER just
makes shutdown() to block if not all data has been transmitted
(and ACKed?).
close() on a socket calls shutdown() automatically (unless
the shutdown() has been already called).

The timeout which you're application runs into
applies after shutting down/closing the connection.

MfG,
	Bernd
-- 
Bernd Petrovitsch                  Email : bernd@...rovitsch.priv.at
There is no cloud, just other people computers. - FSFE
                     LUGA : http://www.luga.at