From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MXjQt-0007Vp-A9 for qemu-devel@nongnu.org; Sun, 02 Aug 2009 18:21:35 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MXjQo-0007Pe-UK for qemu-devel@nongnu.org; Sun, 02 Aug 2009 18:21:34 -0400 Received: from [199.232.76.173] (port=40106 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MXjQo-0007Pa-M8 for qemu-devel@nongnu.org; Sun, 02 Aug 2009 18:21:30 -0400 Received: from terminus.zytor.com ([198.137.202.10]:36945) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MXjQn-0003pf-Vd for qemu-devel@nongnu.org; Sun, 02 Aug 2009 18:21:30 -0400 Message-ID: <4A7610AD.4040901@zytor.com> Date: Sun, 02 Aug 2009 15:18:21 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] The TFTP server has the Sourcerer's Apprentice bug List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "qemu-devel@nongnu.org" Hello, I was investigating a failure to TFTP boot, and I found that the TFTP server in Qemu has the Sourcerer's Apprentice bug (see RFC 1123, section 4.2.3.1. Specifically, it is *required* that the sending side: a) MUST NOT retransmit in response to a duplicated ACK. b) MUST retransmit based on timeouts. (a) is trivial to fix, but (b) requires a little more knowledge of the internals than I'm willing to devote my Sunday afternoon to fixing... -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.