Return-path: Received: from cpsmtpm-eml103.kpnxchange.com ([195.121.3.7]:51631 "EHLO CPSMTPM-EML103.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbZLAVIH (ORCPT ); Tue, 1 Dec 2009 16:08:07 -0500 Message-ID: <4B1585BC.60700@gmail.com> Date: Tue, 01 Dec 2009 22:08:12 +0100 From: Gertjan van Wingerde MIME-Version: 1.0 To: Ivo van Doorn CC: users@rt2x00.serialmonkey.com, linux-wireless@vger.kernel.org, Benoit Papillault Subject: Re: [PATCH v3 4/4] rt2x00: Only remove L2 padding in received frames if there is payload. References: <1259615298-2305-1-git-send-email-gwingerde@gmail.com> <1259615298-2305-4-git-send-email-gwingerde@gmail.com> <1259615298-2305-5-git-send-email-gwingerde@gmail.com> <200912012016.03145.IvDoorn@gmail.com> In-Reply-To: <200912012016.03145.IvDoorn@gmail.com> Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 12/01/09 20:16, Ivo van Doorn wrote: > On Monday 30 November 2009, Gertjan van Wingerde wrote: >> L2 padding will only be present when there is actual payload present. >> >> Signed-off-by: Gertjan van Wingerde >> --- >> drivers/net/wireless/rt2x00/rt2x00dev.c | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c >> index ca2bcc0..b93731b 100644 >> --- a/drivers/net/wireless/rt2x00/rt2x00dev.c >> +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c >> @@ -401,7 +401,9 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev, >> (rxdesc.flags & RX_FLAG_IV_STRIPPED)) >> rt2x00crypto_rx_insert_iv(entry->skb, header_length, >> &rxdesc); >> - else if (rxdesc.dev_flags & RXDONE_L2PAD) >> + else if (header_length && >> + (rxdesc.size > header_length) && >> + (rxdesc.dev_flags & RXDONE_L2PAD)) >> rt2x00queue_remove_l2pad(entry->skb, header_length); >> else >> rt2x00queue_align_payload(entry->skb, header_length); > > Is there a scenario where header_lenght can be 0? > And if there is, shouldn't we have bailed-out completely already? > Actually, there is. ieee80211_get_hdrlen_from_skb returns 0 when it detects that the skb is actually shorter than it should be (according to the frame type indicated by the frame_control field). I'm using that here to check whether actually any payload is present, as a value of 0 means that there isn't even a full header. We should still pass on the frame in that case, for the monitor interfaces. I agree it is a bit of a trick, but it works. --- Gertjan.