[PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[Hangbin Liu]

From: Hangbin Liu <liuhangbin@kylinos.cn>

Use --version to check for nft presence, as older nft versions reject -V.
Ensure the nft tool has JSON support, since we need JSON output for
parsing with jq.

Signed-off-by: Hangbin Liu <liuhangbin@kylinos.cn>
---
 tools/testing/selftests/net/mptcp/mptcp_lib.sh | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 0559bb168203..e5896bfc75d6 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -528,7 +528,14 @@ mptcp_lib_check_tools() {
 				exit ${KSFT_SKIP}
 			fi
 			;;
-		"nft" | "jq")
+		"nft")
+			if ! nft --version &> /dev/null || \
+				! nft -j list ruleset &> /dev/null; then
+				mptcp_lib_pr_skip "nft tool does not support MPTCP"
+				exit ${KSFT_SKIP}
+			fi
+			;;
+		"jq")
 			if ! "${tool}" -V &> /dev/null; then
 				mptcp_lib_pr_skip "Could not run all tests without ${tool}"
 				exit ${KSFT_SKIP}

---
base-commit: 9651c766735c19e7a6b90d731bab53ef7959def8
change-id: 20261008-mptcp_nft_version-9865d63066bf

Best regards,
-- 
Hangbin Liu <liuhangbin@kylinos.cn>

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[MPTCP CI]

Hi Hangbin,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Perf: Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/37761677185

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/4b8f2b367488
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1181524


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[Matthieu Baerts]

Hi Hangbin,

On 08/10/2026 12:00, Hangbin Liu wrote:
> Use --version to check for nft presence, as older nft versions reject -V.
> Ensure the nft tool has JSON support, since we need JSON output for
> parsing with jq.
Thank you for the patch. But do you think it is really needed? 'nft -V'
as been introduced before MPTCP being upstream, and who is building nft
without JSON support?

As an alternative, I can squash this in "selftests: mptcp: convert
iptables to nftables for mptcp_sockopt.sh", just to silence Clashiko.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[Matthieu Baerts]

On 08/10/2026 13:09, Matthieu Baerts wrote:
> On 08/10/2026 12:00, Hangbin Liu wrote:
>> Use --version to check for nft presence, as older nft versions reject -V.
>> Ensure the nft tool has JSON support, since we need JSON output for
>> parsing with jq.
> Thank you for the patch. But do you think it is really needed? 'nft -V'
> as been introduced before MPTCP being upstream, and who is building nft
> without JSON support?
> 
> As an alternative, I can squash this in "selftests: mptcp: convert
> iptables to nftables for mptcp_sockopt.sh", just to silence Clashiko.

I just did that:

New patches for t/upstream:
- 7b299bd2ff08: "squashed" (with conflicts) in "selftests: mptcp:
convert iptables to nftables for mptcp_sockopt.sh"
- 585585efcf69: conflict in
t/selftests-mptcp-convert-iptables-to-nftables-for-mptcp_join.sh
- Results: 1b9bfe42c3a5..5b1d535dc33e (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/a467f29c9a787c2d2d970fcd60116bb19ade259a/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[hangbin.liu]

October 8, 2026 at 7:55 PM, "Matthieu Baerts" <matttbe@kernel.org> wrote:
> 
> On 08/10/2026 13:09, Matthieu Baerts wrote:
> 
> > 
> > On 08/10/2026 12:00, Hangbin Liu wrote:
> > 
> > > 
> > > Use --version to check for nft presence, as older nft versions reject -V.
> > >  Ensure the nft tool has JSON support, since we need JSON output for
> > >  parsing with jq.
> > > 
> >  Thank you for the patch. But do you think it is really needed? 'nft -V'
> >  as been introduced before MPTCP being upstream, and who is building nft
> >  without JSON support?
> >  
> >  As an alternative, I can squash this in "selftests: mptcp: convert
> >  iptables to nftables for mptcp_sockopt.sh", just to silence Clashiko.
> > 
> I just did that:
> 
> New patches for t/upstream:
> - 7b299bd2ff08: "squashed" (with conflicts) in "selftests: mptcp:
> convert iptables to nftables for mptcp_sockopt.sh"
> - 585585efcf69: conflict in
> t/selftests-mptcp-convert-iptables-to-nftables-for-mptcp_join.sh
> - Results: 1b9bfe42c3a5..5b1d535dc33e (export)
> 

Thanks for updating the previous patches and fixing the conflicts.

Regards
Hangbin

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[hangbin.liu]

October 8, 2026 at 7:09 PM, "Matthieu Baerts" <matttbe@kernel.org> wrote:
> 
> Hi Hangbin,
> 
> On 08/10/2026 12:00, Hangbin Liu wrote:
> 
> > 
> > Use --version to check for nft presence, as older nft versions reject -V.
> >  Ensure the nft tool has JSON support, since we need JSON output for
> >  parsing with jq.
> > 
> Thank you for the patch. But do you think it is really needed? 'nft -V'
> as been introduced before MPTCP being upstream, and who is building nft
> without JSON support?

Not really, but ...

> 
> As an alternative, I can squash this in "selftests: mptcp: convert
> iptables to nftables for mptcp_sockopt.sh", just to silence Clashiko.

Yes, this is just to silence Clashiko, which report this issue as medium.
Jakub asks to take action for medium+ reports.

And I see you have squashed this. Thanks for your works!

Thanks
Hangbin

Re: [PATCH mptcp-next] selftests: mptcp: verify nft JSON support

[Matthieu Baerts]

On 08/10/2026 15:45, hangbin.liu@linux.dev wrote:
> October 8, 2026 at 7:09 PM, "Matthieu Baerts" <matttbe@kernel.org> wrote:
>>
>> Hi Hangbin,
>>
>> On 08/10/2026 12:00, Hangbin Liu wrote:
>>
>>>
>>> Use --version to check for nft presence, as older nft versions reject -V.
>>>  Ensure the nft tool has JSON support, since we need JSON output for
>>>  parsing with jq.
>>>
>> Thank you for the patch. But do you think it is really needed? 'nft -V'
>> as been introduced before MPTCP being upstream, and who is building nft
>> without JSON support?
> 
> Not really, but ...
> 
>>
>> As an alternative, I can squash this in "selftests: mptcp: convert
>> iptables to nftables for mptcp_sockopt.sh", just to silence Clashiko.
> 
> Yes, this is just to silence Clashiko, which report this issue as medium.
> Jakub asks to take action for medium+ reports.

Note that we can also do that by adding a note in the commit message, or
reply to the reports. But yes, because we need to send a new version for
these patches, let's fix that too.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.