From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next] bpf: allow BPF programs access skb->skb_iif and skb->dev->ifindex fields Date: Thu, 28 May 2015 21:22:34 +0200 Message-ID: <55676AFA.2030403@iogearbox.net> References: <1432765839-7709-1-git-send-email-ast@plumgrid.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Alexei Starovoitov , "David S. Miller" Return-path: Received: from www62.your-server.de ([213.133.104.62]:52723 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752271AbbE1TWn (ORCPT ); Thu, 28 May 2015 15:22:43 -0400 In-Reply-To: <1432765839-7709-1-git-send-email-ast@plumgrid.com> Sender: netdev-owner@vger.kernel.org List-ID: On 05/28/2015 12:30 AM, Alexei Starovoitov wrote: > classic BPF already exposes skb->dev->ifindex via SKF_AD_IFINDEX extension. > Allow eBPF program to access it as well. Note that classic aborts execution > of the program if 'skb->dev == NULL' (which is inconvenient for program > writers), whereas eBPF returns zero in such case. That's better, yep. > Also expose the 'skb_iif' field, since programs triggered by redirected > packet need to known the original interface index. > Summary: > __skb->ifindex -> skb->dev->ifindex > __skb->ingress_ifindex -> skb->skb_iif > > Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann