Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add mptcp subflow subtest

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

(MPTCP list only)

10 May 2024 21:22:16 Manu Bretelle <chantra@meta.com>:

> On 5/10/24, 7:06 AM, "Alexei Starovoitov" <alexei.starovoitov@gmail.com <mailto:alexei.starovoitov@gmail.com>> wrote:
>
>
> !-------------------------------------------------------------------|
> This Message Is From an External Sender
>
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> |-------------------------------------------------------------------!
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>
> On Thu, May 9, 2024 at 11:31 AM Matthieu Baerts <matttbe@kernel.org <mailto:matttbe@kernel.org>> wrote:
>>
>> Hello,
>>
>> On 09/05/2024 17:49, Matthieu Baerts (NGI0) wrote:
>>> From: Geliang Tang <tanggeliang@kylinos.cn <mailto:tanggeliang@kylinos.cn>>
>>>
>>> This patch adds a subtest named test_subflow to load and verify the newly
>>> added mptcp subflow example in test_mptcp. Add a helper endpoint_init()
>>> to add a new subflow endpoint. Add another helper ss_search() to verify the
>>> fwmark and congestion values set by mptcp_subflow prog using setsockopts.
>>>
>>> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/76 <https://github.com/multipath-tcp/mptcp_net-next/issues/76>
>>> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn <mailto:tanggeliang@kylinos.cn>>
>>> Reviewed-by: Mat Martineau <martineau@kernel.org <mailto:martineau@kernel.org>>
>>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org <mailto:matttbe@kernel.org>>
>>> ---
>>> tools/testing/selftests/bpf/prog_tests/mptcp.c | 109 +++++++++++++++++++++++++
>>> 1 file changed, 109 insertions(+)
>>>
>>> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>> index 274d2e033e39..6039b0ff3801 100644
>>> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>
>> (...)
>>
>>> @@ -340,10 +344,115 @@ static void test_mptcpify(void)
>>> close(cgroup_fd);
>>> }
>>>
>>> +static int endpoint_init(char *flags)
>>> +{
>>> + SYS(fail, "ip -net %s link add veth1 type veth peer name veth2", NS_TEST);
>>> + SYS(fail, "ip -net %s addr add %s/24 dev veth1", NS_TEST, ADDR_1);
>>> + SYS(fail, "ip -net %s link set dev veth1 up", NS_TEST);
>>> + SYS(fail, "ip -net %s addr add %s/24 dev veth2", NS_TEST, ADDR_2);
>>> + SYS(fail, "ip -net %s link set dev veth2 up", NS_TEST);
>>> + SYS(fail, "ip -net %s mptcp endpoint add %s %s", NS_TEST, ADDR_2, flags);
>>
>> I just noticed that this command is failing on the BPF CI:
>>
>> https://github.com/kernel-patches/bpf/actions/runs/9020020315?pr=7009 <https://github.com/kernel-patches/bpf/actions/runs/9020020315?pr=7009>
>>
>> Is it possible that an old version of IPRoute2 is installed?
>> 'ip mptcp' is supported since v5.8.0 (from 2020).
>>
>> It looks like Ubuntu Focal 20.04 is being used, which has the v5.5.0. Do
>> we then need to find another way to set the MPTCP endpoints?
>
>
>
>
> Manu, any idea?
>
> // retrying plain text format.... please outlook, please, make this happen!
>
> Indeed, this is running Ubuntu 20.04. I am planning to eventually update to 22.04 (which has iproute 5.15),
> But I don’t have a good ETA to give other than this is not going to be in the coming month.
>
> It does not seem that iproute provides an easy way to check its version, and the version returned by the container is:
>
> root@081a02e57175:/actions-runner# ip --json -V
> ip utility, iproute2-ss200127
> root@081a02e57175:/actions-runner# dpkg -l iproute2
> Desired=Unknown/Install/Remove/Purge/Hold
> | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
> |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
> ||/ Name           Version        Architecture Description
> +++-==============-==============-============-====================================
> ii  iproute2       5.5.0-1ubuntu1 amd64        networking and traffic control tools
>
>
> How complicated is it to set MPTCP directly using netlink following https://github.com/iproute2/iproute2/blob/397383a30c3b0e3ff551042b6654898a0872b83e/ip/ipmptcp.c#L573 ?
> Seems tools/testing/selftests/bpf/netlink_helpers.c could be useful to deal with the netlink part. And the former link to find out how to format the message?

Maybe we could use pm_nl_ctl?
Could we add a symlink (mptcp_pm_nl_ctl.c) in progs?

Cheers,
Matth