Re: [PATCH bpf-next v7 0/3] Add TC-BPF API

From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: bpf <bpf@vger.kernel.org>, "Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"KP Singh" <kpsingh@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Shaun Crampton" <shaun@tigera.io>,
	Networking <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next v7 0/3] Add TC-BPF API
Date: Fri, 11 Jun 2021 13:01:56 -0700	[thread overview]
Message-ID: <CAEf4BzbgFE2qtC8iw7f5m2maKZhiAYngiYU_kpx30FT0Sy9j-w@mail.gmail.com> (raw)
In-Reply-To: <20210512103451.989420-1-memxor@gmail.com>

On Wed, May 12, 2021 at 3:35 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> This is the seventh version of the TC-BPF series.
>
> It adds a simple API that uses netlink to attach the tc filter and its bpf
> classifier program. Currently, a user needs to shell out to the tc command line
> to be able to create filters and attach SCHED_CLS programs as classifiers. With
> the help of this API, it will be possible to use libbpf for doing all parts of
> bpf program setup and attach.
>
> Changelog contains details of patchset evolution.
>
> In an effort to keep discussion focused, this series doesn't have the high level
> TC-BPF API. It was clear that there is a need for a bpf_link API in the kernel,
> hence that will be submitted as a separate patchset based on this.
>
> The individual commit messages contain more details, and also a brief summary of
> the API.
>
> Changelog:
> ----------

Hey Kartikeya,

There were few issues flagged by Coverity after I synced libbpf to
Github. A bunch of them are netlink.c-related. Could you please take a
look and see if they are false positives or something that we can
actually fix? See links to the issues below. Thanks!

  [0] https://scan3.coverity.com/reports.htm#v40547/p11903/fileInstanceId=53874109&defectInstanceId=10901199&mergedDefectId=141815
  [1] https://scan3.coverity.com/reports.htm#v40547/p11903/fileInstanceId=53874109&defectInstanceId=10901193&mergedDefectId=322806
  [2] https://scan3.coverity.com/reports.htm#v40547/p11903/fileInstanceId=53874109&defectInstanceId=10901197&mergedDefectId=322807
  [3] https://scan3.coverity.com/reports.htm#v40547/p11903/fileInstanceId=53874109&defectInstanceId=10901195&mergedDefectId=322808

[...]

>
> Kumar Kartikeya Dwivedi (3):
>   libbpf: add netlink helpers
>   libbpf: add low level TC-BPF API
>   libbpf: add selftests for TC-BPF API
>
>  tools/lib/bpf/libbpf.h                        |  43 ++
>  tools/lib/bpf/libbpf.map                      |   5 +
>  tools/lib/bpf/netlink.c                       | 554 ++++++++++++++++--
>  tools/lib/bpf/nlattr.h                        |  48 ++
>  .../testing/selftests/bpf/prog_tests/tc_bpf.c | 395 +++++++++++++
>  .../testing/selftests/bpf/progs/test_tc_bpf.c |  12 +
>  6 files changed, 993 insertions(+), 64 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/tc_bpf.c
>  create mode 100644 tools/testing/selftests/bpf/progs/test_tc_bpf.c
>
> --
> 2.31.1
>