From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com ([209.85.192.170]:52310 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567AbaKVAZk (ORCPT ); Fri, 21 Nov 2014 19:25:40 -0500 Received: by mail-pd0-f170.google.com with SMTP id fp1so6288522pdb.29 for ; Fri, 21 Nov 2014 16:25:40 -0800 (PST) Message-ID: <546FD7F5.1060901@gmail.com> Date: Sat, 22 Nov 2014 05:55:25 +0530 From: Varka Bhadram MIME-Version: 1.0 Subject: Re: Unused function mac802154_header_parse() References: <546F62C1.6010500@gmail.com> <20141121171055.GE20364@omega> In-Reply-To: <20141121171055.GE20364@omega> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-wpan-owner@vger.kernel.org List-ID: To: Alexander Aring Cc: linux-wpan - ML On Friday 21 November 2014 10:40 PM, Alexander Aring wrote: > On Fri, Nov 21, 2014 at 09:35:21PM +0530, Varka Bhadram wrote: >> Hi, >> >> There are two header_ops operations defined for mac802154 at [1]. One is for creating header another for parsing. >> >> Creation of mac802154_header_create() happening at [2] by using dev_hard_header(), but i did not find dev_parse_header() >> for header parse by mac802154_header_parse(). >> >> Am i missing anything.? >> > For the dev_parse_header usage: > > `grep -r -n "dev_parse_header" net`: > > net/packet/af_packet.c:1823: sll->sll_halen = dev_parse_header(skb, sll->sll_addr); > net/packet/af_packet.c:2030: sll->sll_halen = dev_parse_header(skb, sll->sll_addr); > > This is used by the packet layer at several places. > > > > I need to dig more into this. It seems that these callback structure are > optional because dev_hard_header and dev_parse_header header return 0 if > they are not implemented. > > Also it seems that when af_packet uses dev_hard_header header it could > be that the control block information is overwritten by packet_skb_cb. > So it's _maybe_ a bug to add additional parameters over control block > information for the header_create callback. My point is that no where mac802154_header_parse() function is called. This has to be called by dev_parse header(). -- Thanks and Regards, Varka Bhadram.