Return-path: Received: from crystal.sipsolutions.net ([195.210.38.204]:51931 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754652AbXHFILu (ORCPT ); Mon, 6 Aug 2007 04:11:50 -0400 Subject: Re: mac80211 driver interface semantics From: Johannes Berg To: Andy Green Cc: Ulrich Kunitz , linux-wireless , Daniel Drake In-Reply-To: <46B30828.3000507@warmcat.com> References: <46B27729.5030406@gentoo.org> <20070803052935.GA12683@deine-taler.de> <46B2E06F.4090706@warmcat.com> <1186134894.4647.24.camel@johannes.berg> <46B3032C.5040306@warmcat.com> <1186137166.4647.34.camel@johannes.berg> <46B304FF.3000305@warmcat.com> <1186137715.4647.36.camel@johannes.berg> <46B30828.3000507@warmcat.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-RnPj+Ll/zPCpq7tDiyzC" Date: Mon, 06 Aug 2007 08:44:18 +0200 Message-Id: <1186382658.21957.45.camel@johannes.berg> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-RnPj+Ll/zPCpq7tDiyzC Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2007-08-03 at 11:49 +0100, Andy Green wrote: > ''Because if you have both a hard monitor and a regular interface > (monitor_during_oper allowed) then we will never check the CRC on frames > that enter the networking path and can get corrupted TCP packets in etc.'= ' >=20 > If the rest of the networking stack didn't trust the packet anyway and > confirms the IP-level checksum, then it can make its own opinion about > the packet. Maybe it helps if I add that the FCS covers more of the packet than the IP checksum; hence, if the FCS fails due to a bit in the area the IP checksum does not cover we will not ACK the packet and get a retransmission, but the IP checksum will check out as good and we'll have a duplicate packet. johannes --=-RnPj+Ll/zPCpq7tDiyzC Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iD8DBQBGtsNC/ETPhpq3jKURAmZIAJ4l1iaYEfxRsn/UK4wDF95lLTM2YQCfd0+I 3bc1nrLJ4cWdsqcDeXytUvQ= =Bahp -----END PGP SIGNATURE----- --=-RnPj+Ll/zPCpq7tDiyzC--