From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f196.google.com ([209.85.214.196]:34214 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387952AbfHGRw7 (ORCPT ); Wed, 7 Aug 2019 13:52:59 -0400 Subject: Re: [bpf-next PATCH 3/3] samples/bpf: xdp_fwd explain bpf_fib_lookup return codes References: <156518133219.5636.728822418668658886.stgit@firesoul> <156518138817.5636.3626699603179533211.stgit@firesoul> From: David Ahern Message-ID: Date: Wed, 7 Aug 2019 11:52:56 -0600 MIME-Version: 1.0 In-Reply-To: <156518138817.5636.3626699603179533211.stgit@firesoul> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: xdp-newbies-owner@vger.kernel.org List-ID: To: Jesper Dangaard Brouer , netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov Cc: xdp-newbies@vger.kernel.org, a.s.protopopov@gmail.com On 8/7/19 6:36 AM, Jesper Dangaard Brouer wrote: > Make it clear that this XDP program depend on the network > stack to do the ARP resolution. This is connected with the > BPF_FIB_LKUP_RET_NO_NEIGH return code from bpf_fib_lookup(). > > Another common mistake (seen via XDP-tutorial) is that users > don't realize that sysctl net.ipv{4,6}.conf.all.forwarding > setting is honored by bpf_fib_lookup. > > Reported-by: Anton Protopopov > Signed-off-by: Jesper Dangaard Brouer > --- > samples/bpf/xdp_fwd_kern.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > Reviewed-by: David Ahern