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

[Manu Bretelle]

> On May 10, 2024, at 12:21 PM, Manu Bretelle <chantra@xxxxxxxx> wrote:
> 
> 
> 
> On 5/10/24, 7:06 AM, "Alexei Starovoitov" <alexei.starovoitov@xxxxxxxxx <mailto:alexei.starovoitov@xxxxxxxxx>> wrote:
> 
> 
> > 
> 
> On Thu, May 9, 2024 at 11:31 AM Matthieu Baerts <matttbe@xxxxxxxxxx <mailto:matttbe@xxxxxxxxxx>> wrote:
>> 
>> Hello,
>> 
>> On 09/05/2024 17:49, Matthieu Baerts (NGI0) wrote:
>>> From: Geliang Tang <tanggeliang@xxxxxxxxxx <mailto:tanggeliang@xxxxxxxxxx>>
>>> 
>>> 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@xxxxxxxxxx <mailto:tanggeliang@xxxxxxxxxx>>
>>> Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx <mailto:martineau@xxxxxxxxxx>>
>>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx <mailto:matttbe@xxxxxxxxxx>>
>>> ---
>>> 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?
> 
> Manu
> 
> 
> 

FYI,

I have just deployed Ubuntu 24.04 runners. Assuming I don’t need to revert the change because of some unforeseen issues, you should now have a mptcp compatible iproute2 on the CI runners:

root@1fdd5d75581b:/actions-runner# ip --json -V
ip utility, iproute2-6.1.0, libbpf 1.3.0
root@1fdd5d75581b:/actions-runner# ip mptcp help
Usage:  ip mptcp endpoint add ADDRESS [ dev NAME ] [ id ID ]
                                      [ port NR ] [ FLAG-LIST ]
        ip mptcp endpoint delete id ID [ ADDRESS ]
        ip mptcp endpoint change [ id ID ] [ ADDRESS ] [ port NR ] CHANGE-OPT
        ip mptcp endpoint show [ id ID ]
        ip mptcp endpoint flush
        ip mptcp limits set [ subflows NR ] [ add_addr_accepted NR ]
        ip mptcp limits show
        ip mptcp monitor
FLAG-LIST := [ FLAG-LIST ] FLAG
FLAG  := [ signal | subflow | backup | fullmesh ]
CHANGE-OPT := [ backup | nobackup | fullmesh | nofullmesh ]

Manu