From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f178.google.com ([209.85.213.178]:38197 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbbLUBQH (ORCPT ); Sun, 20 Dec 2015 20:16:07 -0500 Received: by mail-ig0-f178.google.com with SMTP id jw2so26399600igc.1 for ; Sun, 20 Dec 2015 17:16:07 -0800 (PST) From: Brad Campbell Subject: [PATCH 1/1] ieee802154-cc2520: Check CRC Date: Sun, 20 Dec 2015 20:15:33 -0500 Message-Id: <1450660533-38184-2-git-send-email-bradjc5@gmail.com> In-Reply-To: <1450660533-38184-1-git-send-email-bradjc5@gmail.com> References: <1450660533-38184-1-git-send-email-bradjc5@gmail.com> Sender: linux-wpan-owner@vger.kernel.org List-ID: To: Varka Bhadram , Alexander Aring , linux-wpan@vger.kernel.org Cc: Brad Campbell Add checking the "CRC_OK" bit at the end of incoming packets to make sure the cc2520 driver only passes up valid packets. Because the AUTOCRC bit in the FRMCTRL0 register is set to 1 after init, the CC2520 handles checking the CRC of incoming packets and sets the most significant bit of the last byte of the incoming packet to 1 if the check passed. This patch simply checks that bit. Signed-off-by: Brad Campbell --- drivers/net/ieee802154/cc2520.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/net/ieee802154/cc2520.c b/drivers/net/ieee802154/cc2520.c index e65b605..b54edbf 100644 --- a/drivers/net/ieee802154/cc2520.c +++ b/drivers/net/ieee802154/cc2520.c @@ -450,6 +450,17 @@ cc2520_read_rxfifo(struct cc2520_private *priv, u8 *data, u8 len, u8 *lqi) mutex_unlock(&priv->buffer_mutex); + /* If we are reading the actual packet and not just the length byte, + * check that the CRC is valid. + */ + if (len > 1) { + /* Most significant bit of the last byte of the data buffer + * is a 1 bit CRC indicator. See section 20.3.4. + */ + if (data[len - 1] >> 7 == 0) + return -EINVAL; + } + return status; } -- 2.6.3