From: Yonghong Song <yhs@fb.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>, <bpf@vger.kernel.org>
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
"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>,
"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>,
netdev@vger.kernel.org
Subject: Re: [PATCH bpf-next v3 1/3] libbpf: add helpers for preparing netlink attributes
Date: Tue, 20 Apr 2021 23:37:48 -0700 [thread overview]
Message-ID: <b1648e8a-44de-3d9a-963f-4c79f42e4713@fb.com> (raw)
In-Reply-To: <20210420193740.124285-2-memxor@gmail.com>
On 4/20/21 12:37 PM, Kumar Kartikeya Dwivedi wrote:
> This change introduces a few helpers to wrap open coded attribute
> preparation in netlink.c.
>
> Every nested attribute's closure must happen using the helper
> nlattr_end_nested, which sets its length properly. NLA_F_NESTED is
> enforeced using nlattr_begin_nested helper. Other simple attributes
typo: enforced
> can be added directly.
>
> The maxsz parameter corresponds to the size of the request structure
> which is being filled in, so for instance with req being:
>
> struct {
> struct nlmsghdr nh;
> struct tcmsg t;
> char buf[4096];
> } req;
>
> Then, maxsz should be sizeof(req).
>
> This change also converts the open coded attribute preparation with the
> helpers. Note that the only failure the internal call to nlattr_add
> could result in the nested helper would be -EMSGSIZE, hence that is what
> we return to our caller.
>
> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> tools/lib/bpf/netlink.c | 37 ++++++++++++++-----------------
> tools/lib/bpf/nlattr.h | 48 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 64 insertions(+), 21 deletions(-)
>
[...]
next prev parent reply other threads:[~2021-04-21 6:38 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 19:37 [PATCH bpf-next v3 0/3] Add TC-BPF API Kumar Kartikeya Dwivedi
2021-04-20 19:37 ` [PATCH bpf-next v3 1/3] libbpf: add helpers for preparing netlink attributes Kumar Kartikeya Dwivedi
2021-04-21 6:37 ` Yonghong Song [this message]
2021-04-20 19:37 ` [PATCH bpf-next v3 2/3] libbpf: add low level TC-BPF API Kumar Kartikeya Dwivedi
2021-04-21 6:58 ` Yonghong Song
2021-04-21 17:06 ` Kumar Kartikeya Dwivedi
2021-04-22 1:56 ` Yonghong Song
2021-04-21 18:19 ` Andrii Nakryiko
2021-04-21 19:48 ` Toke Høiland-Jørgensen
2021-04-21 23:14 ` Daniel Borkmann
2021-04-22 9:08 ` Toke Høiland-Jørgensen
2021-04-22 11:51 ` Daniel Borkmann
2021-04-22 12:46 ` Toke Høiland-Jørgensen
2021-04-21 22:59 ` Daniel Borkmann
2021-04-21 23:08 ` Kumar Kartikeya Dwivedi
2021-04-21 23:21 ` Daniel Borkmann
2021-04-21 23:30 ` Kumar Kartikeya Dwivedi
2021-04-21 23:41 ` Daniel Borkmann
2021-04-22 9:47 ` Shaun Crampton
2021-04-22 11:26 ` Daniel Borkmann
2021-04-22 3:43 ` Andrii Nakryiko
2021-04-22 15:35 ` Daniel Borkmann
2021-04-22 18:28 ` Andrii Nakryiko
2021-04-20 19:37 ` [PATCH bpf-next v3 3/3] libbpf: add selftests for " Kumar Kartikeya Dwivedi
2021-04-21 7:01 ` Yonghong Song
2021-04-21 18:24 ` Andrii Nakryiko
2021-04-21 19:56 ` Kumar Kartikeya Dwivedi
2021-04-21 20:38 ` Toke Høiland-Jørgensen
2021-04-21 22:41 ` Daniel Borkmann
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