netdev - Re: Extending socket timestamping API for NTP

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:   Tue, 7 Feb 2017 10:54:22 -0800
From:   Soheil Hassas Yeganeh <soheil@...gle.com>
To:     Miroslav Lichvar <mlichvar@...hat.com>
Cc:     netdev <netdev@...r.kernel.org>,
        Richard Cochran <richardcochran@...il.com>,
        Jiri Benc <jbenc@...hat.com>,
        "Keller, Jacob E" <jacob.e.keller@...el.com>,
        Denny Page <dennypage@...com>,
        Willem de Bruijn <willemb@...gle.com>
Subject: Re: Extending socket timestamping API for NTP

On Tue, Feb 7, 2017 at 6:01 AM, Miroslav Lichvar <mlichvar@...hat.com> wrote:
> 2) new SO_TIMESTAMPING option to receive from the error queue only
>    user data as was passed to sendmsg() instead of Ethernet frames
>
>    Parsing Ethernet and IP headers (especially IPv6 options) is not
>    fun and SOF_TIMESTAMPING_OPT_ID is not always practical, e.g. in
>    applications which process messages from the error queue
>    asynchronously and don't bind/connect their sockets.

This is going to be quite useful. However, I'm not sure if sending
back the original packet would be a proper API. Instead, one option is
to add a control message, so that applications can set the OPT_ID for
the timestamp. Perhaps, something like from user's perspective:

cmsg->cmsg_level             = SOL_SOCKET;
cmsg->cmsg_type              = SCM_TIMESTAMPING_OPT_ID;
cmsg->cmsg_len               = CMSG_LEN(sizeof(__u32));
*((__u32 *) CMSG_DATA(cmsg)) = my_id;

Thanks,
Soheil