From: "H. Peter Anvin" <hpa@zytor.com>
To: Milan Plzik <milan.plzik@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Qemu's internal TFTP server breaks lock-step-iness of TFTP
Date: Thu, 07 Jan 2010 07:42:39 -0800 [thread overview]
Message-ID: <4B4600EF.2040406@zytor.com> (raw)
In-Reply-To: <1262815902.18404.341.camel@localhost>
On 01/06/2010 02:11 PM, Milan Plzik wrote:
> Hello,
>
> according to RFC 1350 and RFC 2347, TFTP server should answer RRQ by
> either OACK or DATA packet. Qemu's internal TFTP server answers RRQ with
> additional options by sending both OACK and DATA packet, thus breaking
> the "lock-step" feature of the protocol, and also confuses client.
>
> Proposed solution would be to, in case of OACK packet, wait for ACK
> from client and just then start sending data. Attached patch implements
> this.
>
> I would like to thank to mbc and th1 (who is the rightful author of
> the patch) from #gpxe for their time, effort and patience with me :)
>
> Milan Plzik
The built-in TFTP server has at least two *serious* other problems:
a) It has the Sorcerer's Apprentice bug (See RFC 1123 and 1350).
b) It doesn't do time-based retransmits.
Note that (a) can't be fixed without fixing (b).
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2010-01-07 15:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-06 22:11 [Qemu-devel] Qemu's internal TFTP server breaks lock-step-iness of TFTP Milan Plzik
2010-01-06 22:43 ` Anthony Liguori
2010-01-07 12:51 ` Milan Plzik
2010-01-07 15:42 ` H. Peter Anvin [this message]
-- strict thread matches above, loose matches on Subject: below --
2010-01-07 12:39 Milan Plzik
2010-01-13 23:26 ` Anthony Liguori
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