From: John Fastabend <john.fastabend@gmail.com>
To: "Edward Cree" <ecree@solarflare.com>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Alexei Starovoitov" <alexei.starovoitov@gmail.com>,
"Jesper Dangaard Brouer" <brouer@redhat.com>
Cc: Song Liu <songliubraving@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>, Martin Lau <kafai@fb.com>,
Yonghong Song <yhs@fb.com>,
Marek Majkowski <marek@cloudflare.com>,
Lorenz Bauer <lmb@cloudflare.com>,
David Miller <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf-next 0/9] xdp: Support multiple programs on a single interface through chain calls
Date: Thu, 03 Oct 2019 12:35:40 -0700 [thread overview]
Message-ID: <5d964d8ccfd90_55732aec43fe05c47b@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <1c9b72f9-1b61-d89a-49a4-e0b8eead853d@solarflare.com>
Edward Cree wrote:
> On 03/10/2019 15:33, Toke Høiland-Jørgensen wrote:
> > In all cases, the sysadmin can't (or doesn't want to) modify any of the
> > XDP programs. In fact, they may just be installed as pre-compiled .so
> > BPF files on his system. So he needs to be able to configure the call
> > chain of different programs without modifying the eBPF program source
> > code.
> Perhaps I'm being dumb, but can't we solve this if we make linking work?
> I.e. myIDS.so has ids_main() function, myFirewall.so has firewall()
> function, and sysadmin writes a little XDP prog to call these:
>
> int main(struct xdp_md *ctx)
> {
> int rc = firewall(ctx), rc2;
>
> switch(rc) {
> case XDP_DROP:
> case XDP_ABORTED:
> default:
> return rc;
> case XDP_PASS:
> return ids_main(ctx);
> case XDP_TX:
> case XDP_REDIRECT:
> rc2 = ids_main(ctx);
> if (rc2 == XDP_PASS)
> return rc;
> return rc2;
> }
> }
>
> Now he compiles this and links it against those .so files, giving him
> a new object file which he can then install.
>
> (One problem which does spring to mind is that the .so files may very
> inconsiderately both name their entry points main(), which makes
> linking against both of them rather challenging. But I think that
> can be worked around with a sufficiently clever linker).
I agree but the same could be done today if ids_main and firewall
were inline functions. Admin can write their little program like above
and just '#include firewall', '#include ids'. Then you don't need
linking although it does make things nicer.
>
> -Ed
next prev parent reply other threads:[~2019-10-03 19:35 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-02 13:30 [PATCH bpf-next 0/9] xdp: Support multiple programs on a single interface through chain calls Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 1/9] hashtab: Add new bpf_map_fd_put_value op Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 2/9] xdp: Add new xdp_chain_map type for specifying XDP call sequences Toke Høiland-Jørgensen
2019-10-02 15:50 ` Lorenz Bauer
2019-10-02 18:25 ` Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 3/9] xdp: Support setting and getting device chain map Toke Høiland-Jørgensen
2019-10-02 15:50 ` Lorenz Bauer
2019-10-02 18:32 ` Toke Høiland-Jørgensen
2019-10-02 18:07 ` kbuild test robot
2019-10-02 18:29 ` kbuild test robot
2019-10-02 13:30 ` [PATCH bpf-next 4/9] xdp: Implement chain call logic to support multiple programs on one interface Toke Høiland-Jørgensen
2019-10-02 17:33 ` kbuild test robot
2019-10-02 17:53 ` kbuild test robot
2019-10-02 13:30 ` [PATCH bpf-next 5/9] tools/include/uapi: Add XDP chain map definitions Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 6/9] tools/libbpf_probes: Add support for xdp_chain map type Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 7/9] bpftool: Add definitions " Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 8/9] libbpf: Add support for setting and getting XDP chain maps Toke Høiland-Jørgensen
2019-10-02 13:30 ` [PATCH bpf-next 9/9] selftests: Add tests for XDP chain calls Toke Høiland-Jørgensen
2019-10-02 15:10 ` [PATCH bpf-next 0/9] xdp: Support multiple programs on a single interface through " Alan Maguire
2019-10-02 15:33 ` Toke Høiland-Jørgensen
2019-10-02 16:34 ` John Fastabend
2019-10-02 18:33 ` Toke Høiland-Jørgensen
2019-10-02 20:34 ` John Fastabend
2019-10-03 7:48 ` Toke Høiland-Jørgensen
2019-10-03 10:09 ` Jesper Dangaard Brouer
2019-10-03 19:45 ` John Fastabend
2019-10-02 16:35 ` Lorenz Bauer
2019-10-02 18:54 ` Toke Høiland-Jørgensen
2019-10-02 16:43 ` John Fastabend
2019-10-02 19:09 ` Toke Høiland-Jørgensen
2019-10-02 19:15 ` Daniel Borkmann
2019-10-02 19:29 ` Toke Høiland-Jørgensen
2019-10-02 19:46 ` Alexei Starovoitov
2019-10-03 7:58 ` Toke Høiland-Jørgensen
2019-10-02 18:38 ` Song Liu
2019-10-02 18:54 ` Song Liu
2019-10-02 19:25 ` Toke Høiland-Jørgensen
2019-10-03 8:53 ` Jesper Dangaard Brouer
2019-10-03 14:03 ` Alexei Starovoitov
2019-10-03 14:33 ` Toke Høiland-Jørgensen
2019-10-03 14:53 ` Edward Cree
2019-10-03 18:49 ` Jesper Dangaard Brouer
2019-10-03 19:35 ` John Fastabend [this message]
2019-10-04 8:09 ` Toke Høiland-Jørgensen
2019-10-04 10:34 ` Edward Cree
2019-10-04 15:58 ` Lorenz Bauer
2019-10-07 16:43 ` Edward Cree
2019-10-07 17:12 ` Lorenz Bauer
2019-10-07 19:21 ` Edward Cree
2019-10-07 21:01 ` Alexei Starovoitov
2019-10-02 19:23 ` Toke Høiland-Jørgensen
2019-10-02 19:49 ` Song Liu
2019-10-03 7:59 ` Toke Høiland-Jørgensen
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