Return-path: Received: from crystal.sipsolutions.net ([195.210.38.204]:37066 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752438AbYDGNrY (ORCPT ); Mon, 7 Apr 2008 09:47:24 -0400 Subject: Re: mac80211 hardware encryption From: Johannes Berg To: Ivo van Doorn Cc: linux-wireless@vger.kernel.org In-Reply-To: <200804071534.38526.IvDoorn@gmail.com> (sfid-20080407_143157_497315_70B0D37E) References: <200804051931.58895.IvDoorn@gmail.com> <1207573761.12481.4.camel@johannes.berg> <200804071534.38526.IvDoorn@gmail.com> (sfid-20080407_143157_497315_70B0D37E) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-E9Df6O4v/xqTCuUkNIe1" Date: Mon, 07 Apr 2008 15:47:21 +0200 Message-Id: <1207576041.12481.21.camel@johannes.berg> (sfid-20080407_144726_443312_90792A9C) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-E9Df6O4v/xqTCuUkNIe1 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, For the TX path, I don't think a memmove() of the header further down is really expensive, it should be within the CPU cache since we operate on the skb header a lot. However, you'd have to undo that too before TX status reporting to get radiotap working properly :/ > I agree, but overall I think this would mean for rt2x00 it will be easier= to stop > sending the skb->data directly to the USB host and use the preallocated D= MA > instead. > Especially the RX path could benefit since otherwise it will be continuou= sly using > memmove on the header and payload to insert the IV and have the payload 4= -byte aligned. How would you go about handling out-of-band IV in the RX path? In the TX path, I can see how you could do that, but in RX? In any case, if you can make usable patches for out-of-band IV I'm not totally against it, but I'd like to keep the overhead as low as possible. In particular, I was thinking of embedding tx_conf into skb->cb[] so you wouldn't have space in there for the IV. johannes --=-E9Df6O4v/xqTCuUkNIe1 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR/ol6KVg1VMiehFYAQL5ZRAAuCk0AEpXy8rDk63eDAgAJR8/fYqCr6Ee 3chiu0VSyE1256YcIJtrmi2FZ+NTb0OjRaBiZznDE/VZRFfVjzyO7d63akHodt4U jRdVjjl++Q+gVf/dsWU2UIutZVXCtlpZLv5g7IYu1CBp5nbfPkHZSfNsoFm0x147 K4hEmLteqtqj9SP9FvP2+h6Gooluaf+H9ErOGRTM5dk6HHHV4gyDTM1DAtpElxbj rvHpZoP/RxtkUUavP13WOujnuqkSmt/dR+POMQXMxMNoPDRpKsDnJP9Ik092UezJ TYvFe6a5d6pAMtRtL4vg5sX4vxmkKtR41TlAaL4lAIPScZfknVXQUA/55f7O85II 0hdek/G6c1xPtXwE8Sr1UuM8dleckIBOF04cYXbbny/urKHZqJW2DF6E2Gle+XBG unN8W0FhGSVdzRpMwMDOYTFOIq6HODDbVMJYgyLsaltRvNF4Plmndppp6PERSiZl v35Iofj/YjQHxiX97jWYAXCFy1+dzMiLrQmwIb3RJ++AzmGx8Zp0hGzULdkMRNXt cBDkwiEDiKZEOL4SxaTURQ8KwKXnGC5hSocrr/z2/hdj++RR2oJNfmUDvIbLAKVr tKfJhIa82n2M2A8ZZ1QnV1t6lN+nx7A0rgCuWKhMGl0UCkhReaQ1Ys30ay3rnHpO 633IR5SY1Ok= =MMFo -----END PGP SIGNATURE----- --=-E9Df6O4v/xqTCuUkNIe1--