Messages in this thread | | | Date | Sat, 12 Aug 2006 09:31:42 -0400 | From | John Richard Moser <> | Subject | Re: How does Linux do RTTM? |
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David Miller wrote: > Please use netdev@vger.kernel.org for discussions about the linux > networking implementation, not linux-kernel@vger.kernle.org >
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. >
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