From mboxrd@z Thu Jan 1 00:00:00 1970 From: Taeung Song Subject: Re: [PATCH] samples/bpf: Fix tc and ip path in xdp2skb_meta.sh Date: Tue, 10 Jul 2018 13:28:34 +0900 Message-ID: <0c986522-e841-f460-125e-4db06f8547a7@gmail.com> References: <20180709150418.32034-1-treeze.taeung@gmail.com> <20180709174029.3c05e750@redhat.com> <30be797e-e247-1b34-6607-0f0fd3b898fd@gmail.com> <20180709212003.10b8e490@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jesper Dangaard Brouer Return-path: In-Reply-To: <20180709212003.10b8e490@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 07/10/2018 04:20 AM, Jesper Dangaard Brouer wrote: > On Tue, 10 Jul 2018 02:44:06 +0900 > Taeung Song wrote: > >> Hi Jesper Dangaard Brouer, >> >> On 07/10/2018 12:40 AM, Jesper Dangaard Brouer wrote: >>> On Tue, 10 Jul 2018 00:04:18 +0900 >>> Taeung Song wrote: >>> >>>> The below path error can occur: >>>> >>>> # ./xdp2skb_meta.sh --dev eth0 --list >>>> ./xdp2skb_meta.sh: line 61: /usr/sbin/tc: No such file or directory >>>> >>>> # which tc >>>> /sbin/tc >>>> >>>> So use 'which' command instead of absolute path of tc and ip >>>> >>>> Fixes: 36e04a2d78d9 ("samples/bpf: xdp2skb_meta shows transferring info from XDP to SKB") >>>> Cc: Jesper Dangaard Brouer >>>> Signed-off-by: Taeung Song >>>> --- >>>> samples/bpf/xdp2skb_meta.sh | 4 ++-- >>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/samples/bpf/xdp2skb_meta.sh b/samples/bpf/xdp2skb_meta.sh >>>> index b9c9549c4c27..67cf7b5f336d 100755 >>>> --- a/samples/bpf/xdp2skb_meta.sh >>>> +++ b/samples/bpf/xdp2skb_meta.sh >>>> @@ -16,8 +16,8 @@ >>>> BPF_FILE=xdp2skb_meta_kern.o >>>> DIR=$(dirname $0) >>>> >>>> -export TC=/usr/sbin/tc >>>> -export IP=/usr/sbin/ip >>>> +export TC=`which tc` >>>> +export IP=`which ip` >>> >>> This is not a good solution, as 'which' can return something else. >>> E.g. on my system I've aliased 'tc' to 'sudo tc', and `which tc` returns: >>> >>> $ which tc >>> alias tc='sudo tc' >>> /usr/bin/sudo >>> >>> The easiest solution is to simply do: >>> >>> export TC=tc >>> export IP=ip >>> >>> The more fancy solution is to allow callers to redefine $IP and $TC: >>> >>> [ -z "$TC" ] && TC=tc >>> [ -z "$IP" ] && IP=ip >>> >> >> Yep, you are right, I'll change it. >> >>> And then you should also fix the use of 'basename', see below patch... >>> >> >> I thought it'd be fine to leave 'basename' as it is, >> because if callers redefine TC=/home/taeung/tc and give >> the options --verbose or --dry-run, 'basename' can more tidily show outputs. > > The 'basename' does not work correctly if e.g. TC='sudo tc'. > > Below output is with 'basename' removed, else it would say "sudo qdisc del ..." > > TC='sudo tc' IP='sudo ip' ./xdp2skb_meta.sh -v --dev mlx5p1 --dry-run > # Device set to: DEV=mlx5p1 > # Dry-run mode: enable VERBOSE and don't call TC+IP > sudo tc qdisc del dev mlx5p1 clsact > sudo tc qdisc add dev mlx5p1 clsact > sudo tc filter add dev mlx5p1 ingress prio 1 handle 1 bpf da obj ./xdp2skb_meta_kern.o sec tc_mark > # Flush XDP on device: mlx5p1 > sudo ip link set dev mlx5p1 xdp off > sudo ip link set dev mlx5p1 xdp obj ./xdp2skb_meta_kern.o sec xdp_mark > > Oops, right. I missed the alias case. >> But it seems to be trivial, I'll resend this patch as v2 based on your >> comment ! > > Thx, already ACKed it :-) > -- Thanks a lot ! Taeung