Re: How does Linux do RTTM?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



David Miller wrote:
> Please use [email protected] for discussions about the linux
> networking implementation, not [email protected]
> 

Kay.

I'm told now that it uses Jiffies for TCP timestamps.  I've had thoughts
on this:

 - I figured a random timestamp with random microsecond skew would be
nice but this might expose internals of the RNG; amusingly I'm trying
not to expose internals of the RNG by exposing system time.

 - Someone recommended starting at zero.  This would work, really,
there's no attacks based on guessing the TCP timestamp value.  This is
nice since if I want to hax0rz then I might make a connection and see
how many jiffies there are to get a feel for the system's uptime; this
tells me how long since you upgraded your kernel, so I have an arsenal
of vulns I KNOW you haven't fixed ready ;)  Starting at 0 doesn't give
that information.

Comments?

> Thanks a lot.
> 

- --
All content of all messages exchanged herein are left in the
Public Domain, unless otherwise explicitly stated.

    Creative brains are a valuable, limited resource. They shouldn't be
    wasted on re-inventing the wheel when there are so many fascinating
    new problems waiting out there.
                                                 -- Eric Steven Raymond

    We will enslave their women, eat their children and rape their
    cattle!
                  -- Bosc, Evil alien overlord from the fifth dimension
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
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=J3TR
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux