netdev - Re: [PATCH net-next 2/3] net-timestamp: add OPT_ID

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 for Android: free password hash cracker in your pocket

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

Message-ID: <66fa91864f534_17d4532943a@willemb.c.googlers.com.notmuch>
Date: Mon, 30 Sep 2024 07:54:46 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: Jason Xing <kerneljasonxing@...il.com>, 
 Willem de Bruijn <willemdebruijn.kernel@...il.com>
Cc: davem@...emloft.net, 
 edumazet@...gle.com, 
 kuba@...nel.org, 
 pabeni@...hat.com, 
 dsahern@...nel.org, 
 shuah@...nel.org, 
 willemb@...gle.com, 
 linux-kselftest@...r.kernel.org, 
 netdev@...r.kernel.org, 
 Jason Xing <kernelxing@...cent.com>
Subject: Re: [PATCH net-next 2/3] net-timestamp: add OPT_ID_TCP test in
 selftests

Jason Xing wrote:
> On Mon, Sep 30, 2024 at 6:42 PM Willem de Bruijn
> <willemdebruijn.kernel@...il.com> wrote:
> >
> > Jason Xing wrote:
> > > From: Jason Xing <kernelxing@...cent.com>
> > >
> > > Introduce a test for SOF_TIMESTAMPING_OPT_ID_TCP for TCP proto so
> > > that we can get aware of whether using write_seq as an initial key
> > > value works as expected.
> >
> > Does the test behave different with this flag set?
> >
> 
> Sorry, my mistake, the last email is not open to the mailing list. So
> I copy that here.
> 
> Not that much, only at the very beginning, this new test will use
> write_seq directly.

The kernel will act differently. But the test does not detect this.
 
> I once thought and wondered if I need to setsockopt() when one or two
> sendmsg() are already done, then we check the behaviour of subsequent
> sendmsg() calls. Then I changed my mind because it's a bit complex. Do
> you think it's a good way to test?

Packetdrill is more suitable for deterministically testing such subtle
differences.

I have a packetdrill test for OPT_ID with and without OPT_ID_TCP. It
is not public yet. As part of upstreaming our packetdrill tests, this
will eventually also be available.