netdev - Re: TCP communication for raw image transmission

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:	Mon, 2 Jan 2012 17:40:54 +0100
From:	Jean-Michel Hautbois <jhautbois@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	netdev@...r.kernel.org
Subject: Re: TCP communication for raw image transmission

>> I don't really know what it can do, but it has to do encoding (even if
>> it is a SoC, with dedicated devices, memory has to be used).
>> The main problem I have, is that I don't have the two boards with me
>> today, and even if I can prototype on x86, I can't conclude as far as
>> I don't test on the real HW.
>
> Thats going to be tough. You could at least use one board and test if it
> can send 100Mbits using netperf (on a x86 target), and check cpu usage.

Mmmh, using netperf you would like to know what the client (my ARM
board) can do ?
How would you test it ? I can have an ARM board on one side, and the
x86 on the other...

>> This is also why I want to prototype my best bet in the first try :).
>> And this is mainly a networking/memory problem.
>
> If the 'no packet loss happens in the network' requirement is OK, then a
> plain sendfile() [ or splice() ] will work.
>
> Limiting each tcp frame to a 1 or 2 lines of your image is about
> limiting MSS on your tcp session (setsockopt( ... TCP_MAXSEG ))

Yes, the idea of limiting tcp frame to 2 lines is to avoid
fragmenting. So, with a MTU at 1500, MSS=1460, I can put 2 lines <=
730bytes. I will probably have ~700bytes.

JM
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html