From: Jakub Sitnicki <jakub@cloudflare.com>
To: Jiayuan Chen <mrpre@163.com>, John Fastabend <john.fastabend@gmail.com>
Cc: bpf@vger.kernel.org, martin.lau@linux.dev, ast@kernel.org,
edumazet@google.com, davem@davemloft.net, dsahern@kernel.org,
kuba@kernel.org, pabeni@redhat.com,
linux-kernel@vger.kernel.org, song@kernel.org,
andrii@kernel.org, mhal@rbox.co, yonghong.song@linux.dev,
daniel@iogearbox.net, xiyou.wangcong@gmail.com,
horms@kernel.org
Subject: Re: [PATCH bpf v3 1/2] bpf: fix wrong copied_seq calculation
Date: Mon, 23 Dec 2024 21:57:22 +0100 [thread overview]
Message-ID: <87h66ujex9.fsf@cloudflare.com> (raw)
In-Reply-To: <ojwjcubviyjxpucryc3ypi4b77h5f5g6ouv7ovaljah5harfyj@jue7hqit2t5n> (Jiayuan Chen's message of "Thu, 19 Dec 2024 17:30:53 +0800")
On Thu, Dec 19, 2024 at 05:30 PM +08, Jiayuan Chen wrote:
> Currently, not all modules using strparser have issues with
> copied_seq miscalculation. The issue exists mainly with
> bpf::sockmap + strparser because bpf::sockmap implements a
> proprietary read interface for user-land: tcp_bpf_recvmsg_parser().
>
> Both this and strp_recv->tcp_read_sock update copied_seq, leading
> to errors.
>
> This is why I rewrote the tcp_read_sock() interface specifically for
> bpf::sockmap.
All right. Looks like reusing read_skb is not going to pan out.
But I think we should not give up just yet. It's easy to add new code.
We can try to break up and parametrize tcp_read_sock - if other
maintainers are not against it. Does something like this work for you?
https://github.com/jsitnicki/linux/commits/review/stp-copied_seq/idea-2/
Other minor feedback I have:
- The newly added code is optional and should depend on
CONFIG_BPF_STREAM_PARSER being enabled. Please check that it builds
with CONFIG_BPF_STREAM_PARSER=n as well.
- Let's not add complexity until it's really needed, and today we don't
need seprate tcp_bpf_proto_ops for IPv4 and IPv6.
- There are style issues with the added test. Please run checkpatch.pl.
next prev parent reply other threads:[~2024-12-23 20:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-18 5:34 [PATCH bpf v3 0/2] bpf: fix wrong copied_seq calculation and add tests Jiayuan Chen
2024-12-18 5:34 ` [PATCH bpf v3 1/2] bpf: fix wrong copied_seq calculation Jiayuan Chen
2024-12-18 15:35 ` Jakub Sitnicki
2024-12-19 9:30 ` Jiayuan Chen
2024-12-20 7:06 ` John Fastabend
2024-12-23 20:57 ` Jakub Sitnicki [this message]
2024-12-23 22:57 ` Jakub Sitnicki
2024-12-24 7:16 ` Jiayuan Chen
2024-12-27 14:09 ` Jakub Sitnicki
2024-12-18 5:34 ` [PATCH bpf v3 2/2] selftests/bpf: add strparser test for bpf Jiayuan Chen
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