From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Peter_Pal=c3=bach?= Subject: VLAN aux info for AF_PACKET available only with ETH_P_ALL Date: Tue, 12 Apr 2016 16:40:20 +0200 Message-ID: <570D08D4.6040000@fri.uniza.sk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from castor.kis.fri.uniza.sk ([158.193.152.2]:47090 "EHLO mail.kis.fri.uniza.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756667AbcDLOuW (ORCPT ); Tue, 12 Apr 2016 10:50:22 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.kis.fri.uniza.sk (Postfix) with ESMTP id 6AA412027948 for ; Tue, 12 Apr 2016 16:40:21 +0200 (CEST) Received: from mail.kis.fri.uniza.sk ([127.0.0.1]) by localhost (castor.kis.fri.uniza.sk [127.0.0.1]) (amavisd-new, port 10044) with LMTP id DdellYyG6qEA for ; Tue, 12 Apr 2016 16:40:21 +0200 (CEST) Received: from [192.168.110.11] (unknown [192.168.110.11]) by mail.kis.fri.uniza.sk (Postfix) with ESMTPSA id 46C1A2002C61 for ; Tue, 12 Apr 2016 16:40:21 +0200 (CEST) Sender: netdev-owner@vger.kernel.org List-ID: Greetings, I am running vanilla Linux kernel v4.4.6. When using AF_PACKET sockets with PACKET_AUXDATA socket option to access the VLAN TCI information of received frames, I have noticed that the VLAN information in struct tpacket_auxdata, namely, - tp_vlan_tci - tp_vlan_tpid - TP_STATUS_VLAN_VALID and TP_STATUS_VLAN_TPID_VALID flags is filled in only when the socket is bound to htons (ETH_P_ALL). If the socket is bound to any specific protocol, the VLAN information fields in struct tpacket_auxdata are set to 0 even if the datagram of the specific protocol was received in an 802.1Q-tagged frame. Is this behavior intentional? If not, I would be honored to try to provide a patch but I am not well-versed in kernel internals so any guidance would be most appreciated. Thanks! Best regards, Peter