From mboxrd@z Thu Jan 1 00:00:00 1970 From: Koki Sanagi Subject: [PATCH] skb: add a comment to skb_csum_unnecessary to avoid miuse Date: Wed, 23 Jan 2013 09:30:16 +0900 Message-ID: <50FF2F18.1050408@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net To: netdev@vger.kernel.org Return-path: Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:56923 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751263Ab3AWAaT (ORCPT ); Tue, 22 Jan 2013 19:30:19 -0500 Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 582073EE0AE for ; Wed, 23 Jan 2013 09:30:17 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 387EA45DE55 for ; Wed, 23 Jan 2013 09:30:17 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1CCDB45DE4F for ; Wed, 23 Jan 2013 09:30:17 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 066EDE38001 for ; Wed, 23 Jan 2013 09:30:17 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id AD20D1DB8037 for ; Wed, 23 Jan 2013 09:30:16 +0900 (JST) Sender: netdev-owner@vger.kernel.org List-ID: Due to its name and appearance, someone thinks this only checks if ip_summed is CHECKSUM_UNNECESARRY. But actually, this returns true even if ip_summed is CHECKSUM_PARTIAL. To avoid misuse, this patch a comment which specifies that CHECKSUM_PARTIAL is OK. Signed-off-by: Koki Sanagi --- include/linux/skbuff.h | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 8b2256e..bc41f64 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2522,6 +2522,16 @@ void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); extern __sum16 __skb_checksum_complete(struct sk_buff *skb); +/** + * skb_csum_unnecessary - check if the checksum needs to be verified + * @skb: skb to check + * + * check if the checksum of this skb needs to be verified. This function is + * effective only against skbs on inbound path. + * + * NB: This returns true if ip_summed is CHECKSUM_UNNECESSARY or + * CHECKSUM_PARTIAL. + **/ static inline int skb_csum_unnecessary(const struct sk_buff *skb) { return skb->ip_summed & CHECKSUM_UNNECESSARY;