100 Commits
Author SHA1 Message Date
Matthieu Baerts (NGI0) bd34fa0257 mptcp: add-addr: always drop other suboptions
When an ADD_ADDR needs to be sent, it could be prepared if there is
enough remaining space and even if the packet is not a pure ACK. But it
would be dropped soon after.

Indeed, in mptcp_pm_add_addr_signal(), there is enough space to fit a
DSS of 20 octets and an ADD_ADDR echo containing an IPv4 address on 8
octets for example. In this case, the packet would be prepared, the
MPTCP_ADD_ADDR_ECHO bit would be removed from pm->addr_signal, but the
option would be silently dropped in mptcp_established_options_add_addr()
not to override DSS info in the union from 'struct mptcp_out_options',
and also because mptcp_write_options() will enforce mutually exclusion
with DSS.

Instead, don't even try to send an ADD_ADDR if it is not a pure ACK.
Retry for each new packet until a pure-ACK is emitted. That's fine to do
that, because each time an ADD_ADDR (echo) is scheduled, a pure ACK is
queued.

This also simplifies the code, and the skb checks can be done earlier,
before the lock.

Note: also, since commit 6d0060f600 ("mptcp: Write MPTCP DSS headers
to outgoing data packets"), opts->ahmac would not have been set to 0
when other suboptions were not dropped, and when sending an ADD_ADDR
echo. That would have resulted in sending an ADD_ADDR using garbage
info, where there was not enough space, instead of an echo one without
the ADD_ADDR HMAC.

Fixes: 1bff1e43a3 ("mptcp: optimize out option generation")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-11-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:27 -07:00
Matthieu Baerts (NGI0) 7690137e70 mptcp: sockopt: set sockopt on all subflows
The mptcp_setsockopt_all_sf(), currently used only with TCP_MAXSEG,
stopped when one subflow returned an error.

Even if it is not wrong, this is different from the other helpers trying
to set the option on all subflows, and then returning an error if at
least one of them had an issue.

Follow this behaviour, for a question of uniformity.

Fixes: 51c5fd09e1 ("mptcp: add TCP_MAXSEG sockopt support")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-8-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Matthieu Baerts (NGI0) 57132affbc mptcp: sockopt: check timestamping ret value
sock_set_timestamping() can fail for different reasons. The returned
value should then be checked.

If sock_set_timestamping() fails for at least one subflow, the first
error is now reported to the userspace, similar to what is done with
other socket options.

Fixes: 9061f24bf8 ("mptcp: sockopt: propagate timestamp request to subflows")
Cc: stable@vger.kernel.org
Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Closes: https://lore.kernel.org/willemdebruijn.kernel.178a41a53d041@gmail.com
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-7-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Matthieu Baerts (NGI0) 92cc6708f4 selftests: rds: config: disable modules
The run.sh script explicitly checks that CONFIG_MODULES is disabled.

By default, this config option is enabled. Explicitly disable it to be
able to run the RDS tests.

Note that writing '# CONFIG_(...) is not set' is usually recommended to
disable an option in the .config, but it looks like selftests usually
set 'CONFIG_(...)=n', which looks clearer.

Fixes: 0f5d680047 ("selftests: rds: add tools/testing/selftests/net/rds/config")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260520-net-rds-config-modules-v1-1-2100df02fe9a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-21 07:39:20 -07:00
Matthieu Baerts (NGI0) 01ff78e4b3 selftests: mptcp: drop nanoseconds width specifier
Using the format specifier +%s%3N with GNU date is honoured, and only
prints 3 digits of the nanoseconds portion of the seconds since epoch,
which corresponds to the milliseconds.

The uutils implementation of date currently does not honour this, and
always prints all 9 digits. This is a known issue [1], but can be worked
around by adapting this test to use nanoseconds instead of microseconds,
and then divide it by 1e6.

This fix is similar to what has been done on systemd side [2], and it is
needed to run the selftests on Ubuntu 26.04, containing uutils 0.8.0.

Note that the Fixes tag is there even if this patch doesn't fix an issue
in the kernel selftests, but it is useful for those using uutils 0.8.0.

Fixes: 048d19d444 ("mptcp: add basic kselftest for mptcp")
Cc: stable@vger.kernel.org
Link: https://github.com/uutils/coreutils/issues/11658 [1]
Link: https://github.com/systemd/systemd/pull/41627 [2]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-6-701e96419f2f@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-19 15:36:35 +02:00
Matthieu Baerts (NGI0) 7995b216a7 mptcp: bpf: Fix type confusion in bpf_mptcp_sock_from_subflow()
bpf_mptcp_sock_from_subflow() only checks if sk->sk_protocol is
IPPROTO_TCP, but RAW socket can bypass it:

  socket(AF_INET, SOCK_RAW, IPPROTO_TCP)

In this case, it would NOT be valid to call sk_is_mptcp() which will
assume sk is a pointer to a struct tcp_sock, and wrongly checks for:
tcp_sk(sk)->is_mptcp.

Fixes: 3bc253c2e6 ("bpf: Add bpf_skc_to_mptcp_sock_proto")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260504210610.180150-4-kuniyu@google.com
2026-05-08 11:38:10 -07:00
Matthieu Baerts (NGI0) 53705ddfa1 selftests: mptcp: pm: restrict 'unknown' check to pm_nl_ctl
When pm_netlink.sh is executed with '-i', 'ip mptcp' is used instead of
'pm_nl_ctl'. IPRoute2 doesn't support the 'unknown' flag, which has only
been added to 'pm_nl_ctl' for this specific check: to ensure that the
kernel ignores such unsupported flag.

No reason to add this flag to 'ip mptcp'. Then, this check should be
skipped when 'ip mptcp' is used.

Fixes: 0cef6fcac2 ("selftests: mptcp: ip_mptcp option for more scripts")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-11-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) 65db7b27b9 selftests: mptcp: check output: catch cmd errors
Using '${?}' inside the if-statement to check the returned value from
the command that was evaluated as part of the if-statement is not
correct: here, '${?}' will be linked to the previous instruction, not
the one that is expected here (${cmd}).

Instead, simply mark the error, except if an error is expected. If
that's the case, 1 can be passed as the 4th argument of this helper.
Three checks from pm_netlink.sh expect an error.

While at it, improve the error message when the command unexpectedly
fails or succeeds.

Note that we could expect a specific returned value, but the checks
currently expecting an error can be used with 'ip mptcp' or 'pm_nl_ctl',
and these two tools don't return the same error code.

Fixes: 2d0c1d27ea ("selftests: mptcp: add mptcp_lib_check_output helper")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-10-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) 166b783440 mptcp: pm: prio: skip closed subflows
When sending an MP_PRIO, closed subflows need to be skipped.

This fixes the case where the initial subflow got closed, re-opened
later, then an MP_PRIO is needed for the same local address.

Note that explicit MP_PRIO cannot be sent during the 3WHS, so it is fine
to use __mptcp_subflow_active().

Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
Cc: stable@vger.kernel.org
Fixes: b29fcfb54c ("mptcp: full disconnect implementation")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-9-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) 62a9b19dce mptcp: pm: ADD_ADDR rtx: return early if no retrans
No need to iterate over all subflows if there is no retransmission
needed.

Exit early in this case then.

Fixes: 30549eebc4 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-8-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) c6d395e2de mptcp: pm: ADD_ADDR rtx: skip inactive subflows
When looking at the maximum RTO amongst the subflows, inactive subflows
were taken into account: that includes stale ones, and the initial one
if it has been already been closed.

Unusable subflows are now simply skipped. Stale ones are used as an
alternative: if there are only stale ones, to take their maximum RTO and
avoid to eventually fallback to net.mptcp.add_addr_timeout, which is set
to 2 minutes by default.

Fixes: 30549eebc4 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-7-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) 3cf1249289 mptcp: pm: ADD_ADDR rtx: resched blocked ADD_ADDR quicker
When an ADD_ADDR needs to be retransmitted and another one has already
been prepared -- e.g. multiple ADD_ADDRs have been sent in a row and
need to be retransmitted later -- this additional retransmission will
need to wait.

In this case, the timer was reset to TCP_RTO_MAX / 8, which is ~15
seconds. This delay is unnecessary long: it should just be rescheduled
at the next opportunity, e.g. after the retransmission timeout.

Without this modification, some issues can be seen from time to time in
the selftests when multiple ADD_ADDRs are sent, and the host takes time
to process them, e.g. the "signal addresses, ADD_ADDR timeout" MPTCP
Join selftest, especially with a debug kernel config.

Note that on older kernels, 'timeout' is not available. It should be
enough to replace it by one second (HZ).

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-6-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0) b7b9a46156 mptcp: pm: ADD_ADDR rtx: free sk if last
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(),
and released at the end.

If at that moment, it was the last reference being held, the sk would
not be freed. sock_put() should then be called instead of __sock_put().

But that's not enough: if it is the last reference, sock_put() will call
sk_free(), which will end up calling sk_stop_timer_sync() on the same
timer, and waiting indefinitely to finish. So it is needed to mark that
the timer is done at the end of the timer handler when it has not been
rescheduled, not to call sk_stop_timer_sync() on "itself".

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0) 9634cb35af mptcp: pm: ADD_ADDR rtx: always decrease sk refcount
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer().
It should then be released in all cases at the end.

Some (unlikely) checks were returning directly instead of calling
sock_put() to decrease the refcount. Jump to a new 'exit' label to call
__sock_put() (which will become sock_put() in the next commit) to fix
this potential leak.

While at it, drop the '!msk' check which cannot happen because it is
never reset, and explicitly mark the remaining one as "unlikely".

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0) 5cd6e0ad79 mptcp: pm: ADD_ADDR rtx: fix potential data-race
This mptcp_pm_add_timer() helper is executed as a timer callback in
softirq context. To avoid any data races, the socket lock needs to be
held with bh_lock_sock().

If the socket is in use, retry again soon after, similar to what is done
with the keepalive timer.

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-3-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0) 03f324f3f1 mptcp: pm: ADD_ADDR rtx: allow ID 0
ADD_ADDR can be sent for the ID 0, which corresponds to the local
address and port linked to the initial subflow.

Indeed, this address could be removed, and re-added later on, e.g. what
is done in the "delete re-add signal" MPTCP Join selftests. So no reason
to ignore it.

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-2-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0) b12014d2d3 mptcp: pm: kernel: correctly retransmit ADD_ADDR ID 0
When adding the ADD_ADDR to the list, the address including the IP, port
and ID are copied. On the other hand, when the endpoint corresponds to
the one from the initial subflow, the ID is set to 0, as specified by
the MPTCP protocol.

The issue is that the ID was reset after having copied the ID in the
ADD_ADDR entry. So the retransmission was done, but using a different ID
than the initial one.

Fixes: 8b8ed1b429 ("mptcp: pm: reuse ID 0 after delete and re-add")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-1-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0) 70ece9d702 mptcp: sockopt: increase seq in mptcp_setsockopt_all_sf
mptcp_setsockopt_all_sf() was missing a call to sockopt_seq_inc(). This
is required not to cause missing synchronization for newer subflows
created later on.

This helper is called each time a socket option is set on subflows, and
future ones will need to inherit this option after their creation.

Fixes: 51c5fd09e1 ("mptcp: add TCP_MAXSEG sockopt support")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-4-b70118df778e@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-04 19:20:50 -07:00
Matthieu Baerts (NGI0) 1774d3cf3c mptcp: pm: kernel: reset fullmesh counter after flush
This variable counts how many MPTCP endpoints have a 'fullmesh' flag
set. After having flushed all MPTCP endpoints, it is then needed to
reset this counter.

Without this reset, this counter exposed to the userspace is wrong, but
also non-fullmesh endpoints added after the flush will not be taken into
account to create subflows in reaction to ADD_ADDRs.

Fixes: f88191c7f3 ("mptcp: pm: in-kernel: record fullmesh endp nb")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260422-mptcp-inc-limits-v6-0-903181771530%40kernel.org?part=15
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260427-net-mptcp-misc-fixes-7-1-rc2-v1-4-7432b7f279fa@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-28 18:36:27 -07:00
Matthieu Baerts (NGI0) f14d6e9c36 mptcp: fastclose msk when linger time is 0
The SO_LINGER socket option has been supported for a while with MPTCP
sockets [1], but it didn't cause the equivalent of a TCP reset as
expected when enabled and its time was set to 0. This was causing some
behavioural differences with TCP where some connections were not
promptly stopped as expected.

To fix that, an extra condition is checked at close() time before
sending an MP_FASTCLOSE, the MPTCP equivalent of a TCP reset.

Note that backporting up to [1] will be difficult as more changes are
needed to be able to send MP_FASTCLOSE. It seems better to stop at [2],
which was supposed to already imitate TCP.

Validated with MPTCP packetdrill tests [3].

Fixes: 268b123874 ("mptcp: setsockopt: support SO_LINGER") [1]
Fixes: d21f834855 ("mptcp: use fastclose on more edge scenarios") [2]
Cc: stable@vger.kernel.org
Reported-by: Lance Tuller <lance@lance0.com>
Closes: https://github.com/lance0/xfr/pull/67
Link: https://github.com/multipath-tcp/packetdrill/pull/196 [3]
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260427-net-mptcp-misc-fixes-7-1-rc2-v1-3-7432b7f279fa@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-28 18:36:27 -07:00
Matthieu Baerts (NGI0) 8e2760eaab Revert "mptcp: add needs_id for netlink appending addr"
This commit was originally adding the ability to add MPTCP endpoints
with ID 0 by accident. The in-kernel PM, handling MPTCP endpoints at the
net namespace level, is not supposed to handle endpoints with such ID,
because this ID 0 is reserved to the initial subflow, as mentioned in
the MPTCPv1 protocol [1], a per-connection setting.

Note that 'ip mptcp endpoint add id 0' stops early with an error, but
other tools might still request the in-kernel PM to create MPTCP
endpoints with this restricted ID 0.

In other words, it was wrong to call the mptcp_pm_has_addr_attr_id
helper to check whether the address ID attribute is set: if it was set
to 0, a new MPTCP endpoint would be created with ID 0, which is not
expected, and might cause various issues later.

Fixes: 584f389426 ("mptcp: add needs_id for netlink appending addr")
Cc: stable@vger.kernel.org
Link: https://datatracker.ietf.org/doc/html/rfc8684#section-3.2-9 [1]
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260407-net-mptcp-revert-pm-needs-id-v2-1-7a25cbc324f8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-08 19:31:16 -07:00
Matthieu Baerts (NGI0) c4a5cb2f00 selftests: mptcp: join: recreate signal endp with same ID
In this "delete re-add signal" MPTCP Join subtest, the endpoint linked
to the initial subflow is removed, but readded once with different ID.

It appears that there was an issue when reusing the same ID, recently
fixed by commit d191101dee ("mptcp: pm: in-kernel: always set ID as
avail when rm endp"). The test then now reuses the same ID the first
time, but continue to use another one (88) the second time.

This should then cover more cases.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/615
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260403-net-next-mptcp-msg_eor-misc-v1-5-b0b33bea3fed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-06 19:14:30 -07:00
Matthieu Baerts (NGI0) 1777f349ff selftests: mptcp: join: check removing signal+subflow endp
This validates the previous commit: endpoints with both the signal and
subflow flags should always be marked as used even if it was not
possible to create new subflows due to the MPTCP PM limits.

For this test, an extra endpoint is created with both the signal and the
subflow flags, and limits are set not to create extra subflows. In this
case, an ADD_ADDR is sent, but no subflows are created. Still, the local
endpoint is marked as used, and no warning is fired when removing the
endpoint, after having sent a RM_ADDR.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 85df533a78 ("mptcp: pm: do not ignore 'subflow' if 'signal' flag is also set")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-5-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 18:21:13 -08:00
Matthieu Baerts (NGI0) 579a752464 mptcp: pm: in-kernel: always mark signal+subflow endp as used
Syzkaller managed to find a combination of actions that was generating
this warning:

  msk->pm.local_addr_used == 0
  WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961
  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961
  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961
  Modules linked in:
  CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full)
  Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014
  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline]
  RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline]
  RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210
  Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a
  RSP: 0018:ffffc90001663880 EFLAGS: 00010293
  RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffff8880158b22d0 R08: 0000000000010425 R09: ffffffffffffffff
  R10: ffffffff82de18ba R11: 0000000000000000 R12: ffff88800641a640
  R13: ffff8880158b1880 R14: ffff88801ec3c900 R15: ffff88800641a650
  FS:  00005555722c3500(0000) GS:ffff8880f909d000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f66346e0f60 CR3: 000000001607c000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115
   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
   genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210
   netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550
   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
   netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
   netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344
   netlink_sendmsg+0x4aa/0x5b0 net/netlink/af_netlink.c:1894
   sock_sendmsg_nosec net/socket.c:727 [inline]
   __sock_sendmsg+0xc9/0xf0 net/socket.c:742
   ____sys_sendmsg+0x272/0x3b0 net/socket.c:2592
   ___sys_sendmsg+0x2de/0x320 net/socket.c:2646
   __sys_sendmsg net/socket.c:2678 [inline]
   __do_sys_sendmsg net/socket.c:2683 [inline]
   __se_sys_sendmsg net/socket.c:2681 [inline]
   __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2681
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x143/0x440 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f66346f826d
  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffc83d8bdc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007f6634985fa0 RCX: 00007f66346f826d
  RDX: 00000000040000b0 RSI: 0000200000000740 RDI: 0000000000000007
  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6634985fa8
  R13: 00007f6634985fac R14: 0000000000000000 R15: 0000000000001770
   </TASK>

The actions that caused that seem to be:

 - Set the MPTCP subflows limit to 0
 - Create an MPTCP endpoint with both the 'signal' and 'subflow' flags
 - Create a new MPTCP connection from a different address: an ADD_ADDR
   linked to the MPTCP endpoint will be sent ('signal' flag), but no
   subflows is initiated ('subflow' flag)
 - Remove the MPTCP endpoint

In this case, msk->pm.local_addr_used has been kept to 0 -- because no
subflows have been created -- but the corresponding bit in
msk->pm.id_avail_bitmap has been cleared when the ADD_ADDR has been
sent. This later causes a splat when removing the MPTCP endpoint because
msk->pm.local_addr_used has been kept to 0.

Now, if an endpoint has both the signal and subflow flags, but it is not
possible to create subflows because of the limits or the c-flag case,
then the local endpoint counter is still incremented: the endpoint is
used at the end. This avoids issues later when removing the endpoint and
calling __mark_subflow_endp_available(), which expects
msk->pm.local_addr_used to have been previously incremented if the
endpoint was marked as used according to msk->pm.id_avail_bitmap.

Note that signal_and_subflow variable is reset to false when the limits
and the c-flag case allows subflows creation. Also, local_addr_used is
only incremented for non ID0 subflows.

Fixes: 85df533a78 ("mptcp: pm: do not ignore 'subflow' if 'signal' flag is also set")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/613
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-4-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 18:21:13 -08:00
Matthieu Baerts (NGI0) 560edd99b5 selftests: mptcp: join: check RM_ADDR not sent over same subflow
This validates the previous commit: RM_ADDR were sent over the first
found active subflow which could be the same as the one being removed.
It is more likely to loose this notification.

For this check, RM_ADDR are explicitly dropped when trying to send them
over the initial subflow, when removing the endpoint attached to it. If
it is dropped, the test will complain because some RM_ADDR have not been
received.

Note that only the RM_ADDR are dropped, to allow the linked subflow to
be quickly and cleanly closed. To only drop those RM_ADDR, a cBPF byte
code is used. If the IPTables commands fail, that's OK, the tests will
continue to pass, but not validate this part. This can be ignored:
another subtest fully depends on such command, and will be marked as
skipped.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 8dd5efb1f9 ("mptcp: send ack for rm_addr")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-3-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 18:21:12 -08:00
Matthieu Baerts (NGI0) fb8d0bccb2 mptcp: pm: avoid sending RM_ADDR over same subflow
RM_ADDR are sent over an active subflow, the first one in the subflows
list. There is then a high chance the initial subflow is picked. With
the in-kernel PM, when an endpoint is removed, a RM_ADDR is sent, then
linked subflows are closed. This is done for each active MPTCP
connection.

MPTCP endpoints are likely removed because the attached network is no
longer available or usable. In this case, it is better to avoid sending
this RM_ADDR over the subflow that is going to be removed, but prefer
sending it over another active and non stale subflow, if any.

This modification avoids situations where the other end is not notified
when a subflow is no longer usable: typically when the endpoint linked
to the initial subflow is removed, especially on the server side.

Fixes: 8dd5efb1f9 ("mptcp: send ack for rm_addr")
Cc: stable@vger.kernel.org
Reported-by: Frank Lorenz <lorenz-frank@web.de>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/612
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-2-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 18:21:12 -08:00
Matthieu Baerts (NGI0) 1e5c009126 selftests/bpf: Remove hexdump dependency
The verification signature header generation requires converting a
binary certificate to a C array. Previously this only worked with xxd,
and a switch to hexdump has been done in commit b640d556a2
("selftests/bpf: Remove xxd util dependency").

hexdump is a more common utility program, yet it might not be installed
by default. When it is not installed, BPF selftests build without
errors, but tests_progs is unusable: it exits with the 255 code and
without any error messages. When manually reproducing the issue, it is
not too hard to find out that the generated verification_cert.h file is
incorrect, but that's time consuming. When digging the BPF selftests
build logs, this line can be seen amongst thousands others, but ignored:

  /bin/sh: 2: hexdump: not found

Here, od is used instead of hexdump. od is coming from the coreutils
package, and this new od command produces the same output when using od
from GNU coreutils, uutils, and even busybox. This is more portable, and
it produces a similar results to what was done before with hexdump:
there is an extra comma at the end instead of trailing whitespaces,
but the C code is not impacted.

Fixes: b640d556a2 ("selftests/bpf: Remove xxd util dependency")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/20260218-bpf-sft-hexdump-od-v2-1-2f9b3ee5ab86@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-18 15:11:20 -08:00
Matthieu Baerts (NGI0) 53e5533691 selftests: mptcp: connect: fix maybe-uninitialize warn
This warning can be seen with GCC 15.2:

  mptcp_connect.c: In function ‘main_loop’:
  mptcp_connect.c:1422:37: warning: ‘peer’ may be used uninitialized [-Wmaybe-uninitialized]
   1422 |                 if (connect(fd, peer->ai_addr, peer->ai_addrlen))
        |                                 ~~~~^~~~~~~~~
  mptcp_connect.c:1377:26: note: ‘peer’ was declared here
   1377 |         struct addrinfo *peer;
        |                          ^~~~

This variable is set in sock_connect_mptcp() in some conditions. If not,
this helper returns an error, and the program stops. So this is a false
positive, but better removing it by initialising peer to NULL.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260205-net-mptcp-misc-fixes-6-19-rc8-v2-4-c2720ce75c34@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06 20:35:07 -08:00
Matthieu Baerts (NGI0) 136f1e168f mptcp: fix kdoc warnings
The following warnings were visible:

  $ ./scripts/kernel-doc -Wall -none \
        net/mptcp/ include/net/mptcp.h include/uapi/linux/mptcp*.h \
        include/trace/events/mptcp.h
  Warning: net/mptcp/token.c:108 No description found for return value of 'mptcp_token_new_request'
  Warning: net/mptcp/token.c:151 No description found for return value of 'mptcp_token_new_connect'
  Warning: net/mptcp/token.c:246 No description found for return value of 'mptcp_token_get_sock'
  Warning: net/mptcp/token.c:298 No description found for return value of 'mptcp_token_iter_next'
  Warning: net/mptcp/protocol.c:4431 No description found for return value of 'mptcp_splice_read'
  Warning: include/uapi/linux/mptcp_pm.h:13 missing initial short description on line:
   * enum mptcp_event_type

Address all of them: either by using the 'Return:' keyword, or by adding
a missing initial short description.

The MPTCP CI will soon report issues with kdoc to avoid introducing new
issues and being flagged by the Netdev CI.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260205-net-mptcp-misc-fixes-6-19-rc8-v2-3-c2720ce75c34@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06 20:35:06 -08:00
Matthieu Baerts (NGI0) 364a7084df mptcp: pm: in-kernel: clarify mptcp_pm_remove_anno_addr()
The variable 'ret' was used, but it was not cleared what it was, and
probably led to an issue [1].

Rename it to 'announced' to avoid confusions.

While at it, remove the returned value of the helper: it is only used in
one place, and the returned value is not used.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/606 [1]
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260205-net-mptcp-misc-fixes-6-19-rc8-v2-2-c2720ce75c34@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06 20:35:06 -08:00
Matthieu Baerts (NGI0) d191101dee mptcp: pm: in-kernel: always set ID as avail when rm endp
Syzkaller managed to find a combination of actions that was generating
this warning:

  WARNING: net/mptcp/pm_kernel.c:1074 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1074 [inline], CPU#1: syz.7.48/2535
  WARNING: net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_fullmesh net/mptcp/pm_kernel.c:1446 [inline], CPU#1: syz.7.48/2535
  WARNING: net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_set_flags_all net/mptcp/pm_kernel.c:1474 [inline], CPU#1: syz.7.48/2535
  WARNING: net/mptcp/pm_kernel.c:1074 at mptcp_pm_nl_set_flags+0x5de/0x640 net/mptcp/pm_kernel.c:1538, CPU#1: syz.7.48/2535
  Modules linked in:
  CPU: 1 UID: 0 PID: 2535 Comm: syz.7.48 Not tainted 6.18.0-03987-gea5f5e676cf5 #17 PREEMPT(voluntary)
  Hardware name: QEMU Ubuntu 25.10 PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1074 [inline]
  RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_kernel.c:1446 [inline]
  RIP: 0010:mptcp_pm_nl_set_flags_all net/mptcp/pm_kernel.c:1474 [inline]
  RIP: 0010:mptcp_pm_nl_set_flags+0x5de/0x640 net/mptcp/pm_kernel.c:1538
  Code: 89 c7 e8 c5 8c 73 fe e9 f7 fd ff ff 49 83 ef 80 e8 b7 8c 73 fe 4c 89 ff be 03 00 00 00 e8 4a 29 e3 fe eb ac e8 a3 8c 73 fe 90 <0f> 0b 90 e9 3d ff ff ff e8 95 8c 73 fe b8 a1 ff ff ff eb 1a e8 89
  RSP: 0018:ffffc9001535b820 EFLAGS: 00010287
  netdevsim0: tun_chr_ioctl cmd 1074025677
  RAX: ffffffff82da294d RBX: 0000000000000001 RCX: 0000000000080000
  RDX: ffffc900096d0000 RSI: 00000000000006d6 RDI: 00000000000006d7
  netdevsim0: linktype set to 823
  RBP: ffff88802cdb2240 R08: 00000000000104ae R09: ffffffffffffffff
  R10: ffffffff82da27d4 R11: 0000000000000000 R12: 0000000000000000
  R13: ffff88801246d8c0 R14: ffffc9001535b8b8 R15: ffff88802cdb1800
  FS:  00007fc6ac5a76c0(0000) GS:ffff8880f90c8000(0000) knlGS:0000000000000000
  netlink: 'syz.3.50': attribute type 5 has an invalid length.
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  netlink: 1232 bytes leftover after parsing attributes in process `syz.3.50'.
  CR2: 0000200000010000 CR3: 0000000025b1a000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   mptcp_pm_set_flags net/mptcp/pm_netlink.c:277 [inline]
   mptcp_pm_nl_set_flags_doit+0x1d7/0x210 net/mptcp/pm_netlink.c:282
   genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115
   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
   genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210
   netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550
   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
   netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
   netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344
   netlink_sendmsg+0x4ab/0x5b0 net/netlink/af_netlink.c:1894
   sock_sendmsg_nosec net/socket.c:718 [inline]
   __sock_sendmsg+0xc9/0xf0 net/socket.c:733
   ____sys_sendmsg+0x272/0x3b0 net/socket.c:2608
   ___sys_sendmsg+0x2de/0x320 net/socket.c:2662
   __sys_sendmsg net/socket.c:2694 [inline]
   __do_sys_sendmsg net/socket.c:2699 [inline]
   __se_sys_sendmsg net/socket.c:2697 [inline]
   __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2697
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xed/0x360 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7fc6adb66f6d
  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007fc6ac5a6ff8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007fc6addf5fa0 RCX: 00007fc6adb66f6d
  RDX: 0000000000048084 RSI: 00002000000002c0 RDI: 000000000000000e
  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  netlink: 'syz.5.51': attribute type 2 has an invalid length.
  R13: 00007fff25e91fe0 R14: 00007fc6ac5a7ce4 R15: 00007fff25e920d7
   </TASK>

The actions that caused that seem to be:

 - Create an MPTCP endpoint for address A without any flags
 - Create a new MPTCP connection from address A
 - Remove the MPTCP endpoint: the corresponding subflows will be removed
 - Recreate the endpoint with the same ID, but with the subflow flag
 - Change the same endpoint to add the fullmesh flag

In this case, msk->pm.local_addr_used has been kept to 0 as expected,
but the corresponding bit in msk->pm.id_avail_bitmap was still unset
after having removed the endpoint, causing the splat later on.

When removing an endpoint, the corresponding endpoint ID was only marked
as available for "signal" types with an announced address, plus all
"subflow" types, but not the other types like an endpoint corresponding
to the initial subflow. In these cases, re-creating an endpoint with the
same ID didn't signal/create anything. Here, adding the fullmesh flag
was creating the splat when calling __mark_subflow_endp_available() from
mptcp_pm_nl_fullmesh(), because msk->pm.local_addr_used was set to 0
while the ID was marked as used.

To fix this issue, the corresponding bit in msk->pm.id_avail_bitmap can
always be set as available when removing an MPTCP in-kernel endpoint. In
other words, moving the call to __set_bit() to do it in all cases,
except for "subflow" types where this bit is handled in a dedicated
helper.

Note: instead of adding a new spin_(un)lock_bh that would be taken in
all cases, do all the actions requiring the spin lock under the same
block.

This modification potentially fixes another issue reported by syzbot,
see [1]. But without a reproducer or more details about what exactly
happened before, it is hard to confirm.

Fixes: e255683c06 ("mptcp: pm: re-using ID of unused removed ADD_ADDR")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/606
Reported-by: syzbot+f56f7d56e2c6e11a01b6@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/68fcfc4a.050a0220.346f24.02fb.GAE@google.com [1]
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260205-net-mptcp-misc-fixes-6-19-rc8-v2-1-c2720ce75c34@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-06 20:35:06 -08:00
Matthieu Baerts (NGI0) 4dca8d0030 selftests: mptcp: join: no SKIP mark for group checks
When executing the last MPTCP selftests on older kernels, this output is
printed:

  # 001 no JOIN
  #       join Rx                             [SKIP]
  #       join Tx                             [SKIP]
  #       fallback                            [SKIP]

In fact, behind each line, a few counters are checked, and likely not
all of them have been skipped because the they are not available on
these kernels. Instead, "new" and unsupported counters for these groups
are now ignored, and [ OK ] will be printed instead of [SKIP].

Note that on the MPTCP CI, when validating the dev versions, any
unsupported counter will cause the tests to fail. So this is safe not to
print 'SKIP' for these group checks.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-15-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) ae68da495a selftests: mptcp: connect cleanup TFO setup
To the TFO, only the file descriptor is needed, the family is not.

Also, the error can be handled the same way when 'sendto()' or
'connect()' are used. Only the printed error message is different.

This avoids a bit of confusions.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-14-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) 79d5069cfb selftests: mptcp: join: avoid declaring i if not used
A few loops were declaring 'i', but this variable was not used.

To avoid confusions, use '_' instead: it is more explicit to mark that
this variable is not needed.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-13-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) 91453a62e5 selftests: mptcp: join chk_stale_nr: avoid dup stats
nstat outputs are already printed when calling 'fail_test', no need to
do it again.

While at it, no need to use the dump_stats variable, print the extra
stats directly. And use 'ip -n $ns' instead of 'ip netns exec $ns',
shorter and clearer.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-12-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) 62c0774f0f selftests: mptcp: join: userspace: wait for new events
Instead of waiting for a random amount of time (1 second), wait for an
event to be received on the other side.

To do that, when an address is announced (userspace_pm_add_addr), the
ANNOUNCED is expected. When a new subflow is created
(userspace_pm_add_sf), the SUB_ESTABLISHED event is expected.

With this, the tests can finish quicker.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-11-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) ab8b64ca3a selftests: mptcp: join: fix wait_mpj helper
It looks like most of the time, this helper was simply waiting a bit
more than one second: the previous MPJoin counter was often already at
the expected value. So at the end, it was just checking 10 times for
the MPJoin counter to change, but it was not happening. For the tests,
that was time, it was just waiting longer for nothing.

Instead, use 'wait_mpj' with the expected counter: in the tests, the MPJ
counter can easily be predicted. While at it, stop passing the netns as
argument: here the received MPJoin ACK is checked, which happens on the
server side. If later on, this needs to be checked on the client side,
the helper can be adapted for this case, but better avoid confusions now
if it is not needed.

While at it, stop using 'i' for the variable if it is not used.

With this, the tests can finish quicker.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-10-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) 32207bed05 selftests: mptcp: join: wait for estab event instead of MPJ
'wait_mpj' was used just after having created a background connection,
but before creating new subflows. So no MPJ were sent. The intention was
to wait for the connection to be established, which was the same as
doing a simple sleep with a "random" value.

Instead, wait for an "established" event. With this, the tests can
finish quicker.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-9-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) f7f4e8e944 selftests: mptcp: diag: sort all #include
This file is the only one from this directory not to have all these
header inclusions sorted by type and alphabetical order.

Adapt them, to ease the reading, prevent conflicts during potential
future backport modifying these lines, and also to avoid having UAPI
header inclusions before libc ones, see [1].

Link: https://lore.kernel.org/20260120-uapi-sockaddr-v2-1-63c319111cf6@linutronix.de
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-8-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:34 -08:00
Matthieu Baerts (NGI0) d7e712b66f mptcp: pm: align endpoint flags size with the NL specs
The MPTCP Netlink specs describe the 'flags' as a u32 type. Internally,
a u8 type was used.

Using a u8 is currently fine, because only the 5 first bits are used.
But there is also no reason not to be aligns with the specs, and
to stick to a u8. Especially because there is a whole of 3 bytes after
in both mptcp_pm_local and mptcp_pm_addr_entry structures.

Also, setting it to a u32 will allow future flags, just in case.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-5-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 18:45:09 -08:00
Matthieu Baerts (NGI0) c5d5ecf21f selftests: mptcp: join: fix local endp not being tracked
When running this mptcp_join.sh selftest on older kernel versions not
supporting local endpoints tracking, this test fails because 3 MP_JOIN
ACKs have been received, while only 2 were expected.

It is not clear why only 2 MP_JOIN ACKs were expected on old kernel
versions, while 3 MP_JOIN SYN and SYN+ACK were expected. When testing on
the v5.15.197 kernel, 3 MP_JOIN ACKs are seen, which is also what is
expected in the selftests included in this kernel version, see commit
f4480eaad489 ("selftests: mptcp: add missing join check").

Switch the expected MP_JOIN ACKs to 3. While at it, move this
chk_join_nr helper out of the special condition for older kernel
versions as it is now the same as with more recent ones. Also, invert
the condition to be more logical: what's expected on newer kernel
versions having such helper first.

Fixes: d4c81bbb86 ("selftests: mptcp: join: support local endpoint being tracked or not")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260127-net-mptcp-dup-nl-events-v1-5-7f71e1bc4feb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 20:58:51 -08:00
Matthieu Baerts (NGI0) 2ef9e3a384 selftests: mptcp: check subflow errors in close events
This validates the previous commit: subflow closed events should contain
an error field when a subflow got closed with an error, e.g. reset or
timeout.

For this test, the chk_evt_nr helper has been extended to check
attributes in the matched events.

In this test, the 2 subflow closed events should have an error.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 15cc104533 ("mptcp: deliver ssk errors to msk")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260127-net-mptcp-dup-nl-events-v1-4-7f71e1bc4feb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 20:58:50 -08:00
Matthieu Baerts (NGI0) dccf46179d mptcp: only reset subflow errors when propagated
Some subflow socket errors need to be reported to the MPTCP socket: the
initial subflow connect (MP_CAPABLE), and the ones from the fallback
sockets. The others are not propagated.

The issue is that sock_error() was used to retrieve the error, which was
also resetting the sk_err field. Because of that, when notifying the
userspace about subflow close events later on from the MPTCP worker, the
ssk->sk_err field was always 0.

Now, the error (sk_err) is only reset when propagating it to the msk.

Fixes: 15cc104533 ("mptcp: deliver ssk errors to msk")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260127-net-mptcp-dup-nl-events-v1-3-7f71e1bc4feb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 20:58:50 -08:00
Matthieu Baerts (NGI0) 8467458dfa selftests: mptcp: check no dup close events after error
This validates the previous commit: subflow closed events are re-sent
with less info when the initial subflow is disconnected after an error
and each time a subflow is closed after that.

In this new test, the userspace PM is involved because that's how it was
discovered, but it is not specific to it. The initial subflow is
terminated with a RESET, and that will cause the subflow disconnect.
Then, a new subflow is initiated, but also got rejected, which cause a
second subflow closed event, but not a third one.

While at it, in case of failure to get the expected amount of events,
the events are printed.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: d82809b6c5 ("mptcp: avoid duplicated SUB_CLOSED events")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260127-net-mptcp-dup-nl-events-v1-2-7f71e1bc4feb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 20:58:50 -08:00
Matthieu Baerts (NGI0) 280d654324 mptcp: avoid dup SUB_CLOSED events after disconnect
In case of subflow disconnect(), which can also happen with the first
subflow in case of errors like timeout or reset, mptcp_subflow_ctx_reset
will reset most fields from the mptcp_subflow_context structure,
including close_event_done. Then, when another subflow is closed, yet
another SUB_CLOSED event for the disconnected initial subflow is sent.
Because of the previous reset, there are no source address and
destination port.

A solution is then to also check the subflow's local id: it shouldn't be
negative anyway.

Another solution would be not to reset subflow->close_event_done at
disconnect time, but when reused. But then, probably the whole reset
could be done when being reused. Let's not change this logic, similar
to TCP with tcp_disconnect().

Fixes: d82809b6c5 ("mptcp: avoid duplicated SUB_CLOSED events")
Cc: stable@vger.kernel.org
Reported-by: Marco Angaroni <marco.angaroni@italtel.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/603
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260127-net-mptcp-dup-nl-events-v1-1-7f71e1bc4feb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 20:58:50 -08:00
Matthieu Baerts (NGI0) 29f4801e9c selftests: mptcp: pm: ensure unknown flags are ignored
This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781a6c1b8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-12-08 23:54:02 -08:00
Matthieu Baerts (NGI0) 0ace3297a7 mptcp: pm: ignore unknown endpoint flags
Before this patch, the kernel was saving any flags set by the userspace,
even unknown ones. This doesn't cause critical issues because the kernel
is only looking at specific ones. But on the other hand, endpoints dumps
could tell the userspace some recent flags seem to be supported on older
kernel versions.

Instead, ignore all unknown flags when parsing them. By doing that, the
userspace can continue to set unsupported flags, but it has a way to
verify what is supported by the kernel.

Note that it sounds better to continue accepting unsupported flags not
to change the behaviour, but also that eases things on the userspace
side by adding "optional" endpoint types only supported by newer kernel
versions without having to deal with the different kernel versions.

A note for the backports: there will be conflicts in mptcp.h on older
versions not having the mentioned flags, the new line should still be
added last, and the '5' needs to be adapted to have the same value as
the last entry.

Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-1-9e4781a6c1b8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-12-08 23:54:02 -08:00
Matthieu Baerts (NGI0) 0e4ec14dc1 selftests: mptcp: join: userspace: longer timeout
In rare cases, when the test environment is very slow, some userspace
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to have a longer
timeout, and even go over the default one. This connection will be
killed at the end, after the verifications: increasing the timeout
doesn't change anything, apart from avoiding it to end before the end of
the verifications.

To play it safe, all userspace tests not waiting for the end of the
transfer are now having a longer timeout: 2 minutes.

The Fixes commit was making the connection longer, but still, the
default timeout would have stopped it after 1 minute, which might not be
enough in very slow environments.

Fixes: 290493078b ("selftests: mptcp: join: userspace: longer transfer")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Link: https://patch.msgid.link/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-9-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-19 20:07:15 -08:00
Matthieu Baerts (NGI0) fb13c6bb81 selftests: mptcp: join: endpoints: longer timeout
In rare cases, when the test environment is very slow, some endpoints
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to have a longer
timeout, and even go over the default one. This connection will be
killed at the end, after the verifications: increasing the timeout
doesn't change anything, apart from avoiding it to end before the end of
the verifications.

To play it safe, all endpoints tests not waiting for the end of the
transfer are now having a longer timeout: 2 minutes.

The Fixes commit was making the connection longer, but still, the
default timeout would have stopped it after 1 minute, which might not be
enough in very slow environments.

Fixes: 6457595db9 ("selftests: mptcp: join: endpoints: longer transfer")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Link: https://patch.msgid.link/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-8-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-19 20:07:15 -08:00
Matthieu Baerts (NGI0) efff6cd53a selftests: mptcp: join: fastclose: remove flaky marks
After recent fixes like the parent commit, and "selftests: mptcp:
connect: trunc: read all recv data", the two fastclose subtests no
longer look flaky any more.

It then feels fine to remove these flaky marks, to no longer ignore
these subtests in case of errors.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-7-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-19 20:07:15 -08:00
Matthieu Baerts (NGI0) eea2f44870 selftests: mptcp: get stats just before timing out
Recently, some debugging happened around a test that was timing out. The
stats were showing connections being closed which was confusing because
the closing state was caused by the timeout stopping the transfer.

To avoid such confusion, the timeout is no longer done per mptcp_connect
process, but separately. In case of timeout, the stats are now printed,
then the apps are killed.

The stats will still be printed after the kill, but that's fine, and
this might even be useful, just in case. Timeout should be exceptional.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-8-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:47 -08:00
Matthieu Baerts (NGI0) 39348f5f2f selftests: mptcp: wait for port instead of sleep
After having started mptcp_connect in listening mode,
'mptcp_lib_wait_local_port_listen' can be used to wait for the listening
socket to be ready.

This is better than using the 'sleep' command, not to pause for a fixed
amount of time, but waiting for an event. This helper is used in all
other MPTCP selftests, but not in these two.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-7-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:47 -08:00
Matthieu Baerts (NGI0) 8c1fe0a500 selftests: mptcp: connect: avoid double packet traces
When the same netns is used for the listener and the connector, no need
to take exactly the same packet trace twice, one is enough.

This avoids confusions when the traces are the same, and wasting
resources which might not help reproducing an issue.

While at it, avoid long lines and double spaces now that these lines are
no longer aligned.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-6-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:47 -08:00
Matthieu Baerts (NGI0) 71388a9f33 selftests: mptcp: lib: get counters from nstat history
Before, 'nstat' was used to retrieve each individual counter: this means
querying 4 different sources from /proc/net and iterating over 100+
counters each time. Instead, the stats could be retrieved once, and the
output file could be parsed for each counter. Even better, such file is
already present: the nstat history file.

To be able to get this working, the nstat history file also needs to
contains zero counters too, so it is still possible to know if a counter
is missing or set to 0.

This also simplifies mptcp_connect.sh: instead of checking multiple
counters before and after a test to compute the difference, the stats
history files can be reset before each test, and nstat can display only
the difference.

mptcp_lib_get_counter() continues to work when no history file is
available: by fetching nstat directly, like before. This is the case in
diag.sh and userspace_pm.sh where there is no need to save the history
file. This is also the case in mptcp_join.sh, when 'run_tests' is
executed in the background: easier to continue fetching counters than
updating the history each time it is needed.

Note: 'nstat' is called with '-s' in mptcp_lib_nstat_get(), so this
helper can be called multiple times during the test if needed.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-5-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:47 -08:00
Matthieu Baerts (NGI0) 658e531417 selftests: mptcp: join: dump stats from history
In case of errors, dump the stats from history instead of using nstat.

There are multiple advantages to that:

- The same filters from pr_err_stats are used, e.g. the unused 'rate'
  column is not displayed.

- The counters are closer to the ones from when the test stopped.

- While at it, the errors can be better presented: error colours, a
  small indentation to distinguish the different parts, extra new lines.

Even if it should only happen in rare cases -- internal errors, or netns
issues -- if no history is available, 'nstat' is used like before, just
in case.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-4-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:46 -08:00
Matthieu Baerts (NGI0) 2e6daf6b9b selftests: mptcp: lib: stats: remove nstat rate columns
With the MPTCP selftests, the nstat daemon is not used. It means that
the last column (the rate) is always 0.0, and that's not something
interesting to display.

Then, this last column can be filtered out.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-3-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:46 -08:00
Matthieu Baerts (NGI0) a89fc262b6 selftests: mptcp: lib: remove stats files args
Now that these files are written from MPTCP lib helpers, the stats file
paths are uniformed. Then, no need to specify them from the each
selftest.

No behavioural changes intended.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-2-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:46 -08:00
Matthieu Baerts (NGI0) d3305c016a selftests: mptcp: lib: introduce 'nstat_{init,get}'
These new helpers are easier to read than the long and multi lines
commands. Plus it will ease the addition of new features related to that
in the next commits.

No behavioural changes intended.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-1-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17 19:27:46 -08:00
Matthieu Baerts (NGI0) 852b644acb selftests: mptcp: join: properly kill background tasks
The 'run_tests' function is executed in the background, but killing its
associated PID would not kill the children tasks running in the
background.

To properly kill all background tasks, 'kill -- -PID' could be used, but
this requires kill from procps-ng. Instead, all children tasks are
listed using 'ps', and 'kill' is called with all PIDs of this group.

Fixes: 31ee4ad86a ("selftests: mptcp: join: stop transfer when check is done (part 1)")
Cc: stable@vger.kernel.org
Fixes: 04b57c9e09 ("selftests: mptcp: join: stop transfer when check is done (part 2)")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-6-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:49 -08:00
Matthieu Baerts (NGI0) ee79980f7a selftests: mptcp: connect: trunc: read all recv data
MPTCP Join "fastclose server" selftest is sometimes failing because the
client output file doesn't have the expected size, e.g. 296B instead of
1024B.

When looking at a packet trace when this happens, the server sent the
expected 1024B in two parts -- 100B, then 924B -- then the MP_FASTCLOSE.
It is then strange to see the client only receiving 296B, which would
mean it only got a part of the second packet. The problem is then not on
the networking side, but rather on the data reception side.

When mptcp_connect is launched with '-f -1', it means the connection
might stop before having sent everything, because a reset has been
received. When this happens, the program was directly stopped. But it is
also possible there are still some data to read, simply because the
previous 'read' step was done with a buffer smaller than the pending
data, see do_rnd_read(). In this case, it is important to read what's
left in the kernel buffers before stopping without error like before.

SIGPIPE is now ignored, not to quit the app before having read
everything.

Fixes: 6bf41020b7 ("selftests: mptcp: update and extend fastclose test-cases")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-5-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:49 -08:00
Matthieu Baerts (NGI0) 290493078b selftests: mptcp: join: userspace: longer transfer
In rare cases, when the test environment is very slow, some userspace
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to make the
connection longer. This connection will be killed at the end, after the
verifications, so making it longer doesn't change anything, apart from
avoid it to end before the end of the verifications

To play it safe, all userspace tests not waiting for the end of the
transfer are now sharing a longer file (128KB) at slow speed.

Fixes: 4369c198e5 ("selftests: mptcp: test userspace pm out of transfer")
Cc: stable@vger.kernel.org
Fixes: b2e2248f36 ("selftests: mptcp: userspace pm create id 0 subflow")
Fixes: e3b47e460b ("selftests: mptcp: userspace pm remove initial subflow")
Fixes: b9fb176081 ("selftests: mptcp: userspace pm send RM_ADDR for ID 0")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-4-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:49 -08:00
Matthieu Baerts (NGI0) 6457595db9 selftests: mptcp: join: endpoints: longer transfer
In rare cases, when the test environment is very slow, some userspace
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to make the
connection longer. This connection will be killed at the end, after the
verifications, so making it longer doesn't change anything, apart from
avoid it to end before the end of the verifications

To play it safe, all endpoints tests not waiting for the end of the
transfer are now sharing a longer file (128KB) at slow speed.

Fixes: 69c6ce7b6e ("selftests: mptcp: add implicit endpoint test case")
Cc: stable@vger.kernel.org
Fixes: e274f71540 ("selftests: mptcp: add subflow limits test-cases")
Fixes: b5e2fb832f ("selftests: mptcp: add explicit test case for remove/readd")
Fixes: e06959e9ee ("selftests: mptcp: join: test for flush/re-add endpoints")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-3-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:48 -08:00
Matthieu Baerts (NGI0) aea73bae66 selftests: mptcp: join: rm: set backup flag
Some of these 'remove' tests rarely fail because a subflow has been
reset instead of cleanly removed. This can happen when one extra subflow
which has never carried data is being closed (FIN) on one side, while
the other is sending data for the first time.

To avoid such subflows to be used right at the end, the backup flag has
been added. With that, data will be only carried on the initial subflow.

Fixes: d2c4333a80 ("selftests: mptcp: add testcases for removing addrs")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-2-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:48 -08:00
Matthieu Baerts (NGI0) 63c643aa7b selftests: mptcp: connect: fix fallback note due to OoO
The "fallback due to TCP OoO" was never printed because the stat_ooo_now
variable was checked twice: once in the parent if-statement, and one in
the child one. The second condition was then always true then, and the
'else' branch was never taken.

The idea is that when there are more ACK + MP_CAPABLE than expected, the
test either fails if there was no out of order packets, or a notice is
printed.

Fixes: 69ca3d29a7 ("mptcp: update selftest for fallback due to OoO")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-1-a4332c714e10@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-11 17:49:47 -08:00
Matthieu Baerts (NGI0) 5c59df126b selftests: mptcp: join: validate extra bind cases
By design, an MPTCP connection will not accept extra subflows where no
MPTCP listening sockets can accept such requests.

In other words, it means that if the 'server' listens on a specific
address / device, it cannot accept MP_JOIN sent to a different address /
device. Except if there is another MPTCP listening socket accepting
them.

This is what the new tests are validating:

 - Forcing a bind on the main v4/v6 address, and checking that MP_JOIN
   to announced addresses are not accepted.

 - Also forcing a bind on the main v4/v6 address, but before, another
   listening socket is created to accept additional subflows. Note that
   'mptcpize run nc -l' -- or something else only doing: socket(MPTCP),
   bind(<IP>), listen(0) -- would be enough, but here mptcp_connect is
   reused not to depend on another tool just for that.

 - Same as the previous one, but using v6 link-local addresses: this is
   a bit particular because it is required to specify the outgoing
   network interface when connecting to a link-local address announced
   by the other peer. When using the routing rules, this doesn't work
   (the outgoing interface is not known) ; but it does work with a
   'laminar' endpoint having a specified interface.

Note that extra small modifications are needed for these tests to work:

 - mptcp_connect's check_getpeername_connect() check should strip the
   specified interface when comparing addresses.

 - With IPv6 link-local addresses, it is required to wait for them to
   be ready (no longer in 'tentative' mode) before using them, otherwise
   the bind() will not be allowed.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/591
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251101-net-next-mptcp-fm-endp-nb-bind-v1-4-b4166772d6bb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04 17:15:07 -08:00
Matthieu Baerts (NGI0) 4a6220a453 selftests: mptcp: join: do_transfer: reduce code dup
The same extra long commands are present twice, with small differences:
the variable for the stdin file is different.

Use new dedicated variables in one command to avoid this code
duplication.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251101-net-next-mptcp-fm-endp-nb-bind-v1-3-b4166772d6bb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04 17:15:06 -08:00
Matthieu Baerts (NGI0) e461e8a799 mptcp: pm: in kernel: only use fullmesh endp if any
Our documentation is saying that the in-kernel PM is only using fullmesh
endpoints to establish subflows to announced addresses when at least one
endpoint has a fullmesh flag. But this was not totally correct: only
fullmesh endpoints were used if at least one endpoint *from the same
address family as the received ADD_ADDR* has the fullmesh flag.

This is confusing, and it seems clearer not to have differences
depending on the address family.

So, now, when at least one MPTCP endpoint has a fullmesh flag, the local
addresses are picked from all fullmesh endpoints, which might be 0 if
there are no endpoints for the correct address family.

One selftest needs to be adapted for this behaviour change.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251101-net-next-mptcp-fm-endp-nb-bind-v1-2-b4166772d6bb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04 17:15:06 -08:00
Matthieu Baerts (NGI0) f88191c7f3 mptcp: pm: in-kernel: record fullmesh endp nb
Instead of iterating over all endpoints, under RCU read lock, just to
check if one of them as the fullmesh flag, we can keep a counter of
fullmesh endpoint, similar to what is done with the other flags.

This counter is now checked, before iterating over all endpoints.

Similar to the other counters, this new one is also exposed. A userspace
app can then know when it is being used in a fullmesh mode, with
potentially (too) many subflows.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251101-net-next-mptcp-fm-endp-nb-bind-v1-1-b4166772d6bb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04 17:15:06 -08:00
Matthieu Baerts (NGI0) a9649dfbe5 selftests: mptcp: join: mark laminar tests as skipped if not supported
The call to 'continue_if' was missing: it properly marks a subtest as
'skipped' if the attached condition is not valid.

Without that, the test is wrongly marked as passed on older kernels.

Fixes: c912f935a5 ("selftests: mptcp: join: validate new laminar endp")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-5-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:47 -07:00
Matthieu Baerts (NGI0) c3496c052a selftests: mptcp: join: mark 'delete re-add signal' as skipped if not supported
The call to 'continue_if' was missing: it properly marks a subtest as
'skipped' if the attached condition is not valid.

Without that, the test is wrongly marked as passed on older kernels.

Fixes: b5e2fb832f ("selftests: mptcp: add explicit test case for remove/readd")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-4-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:46 -07:00
Matthieu Baerts (NGI0) 973f80d715 selftests: mptcp: join: mark implicit tests as skipped if not supported
The call to 'continue_if' was missing: it properly marks a subtest as
'skipped' if the attached condition is not valid.

Without that, the test is wrongly marked as passed on older kernels.

Fixes: 36c4127ae8 ("selftests: mptcp: join: skip implicit tests if not supported")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-3-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:46 -07:00
Matthieu Baerts (NGI0) d68460bc31 selftests: mptcp: join: mark 'flush re-add' as skipped if not supported
The call to 'continue_if' was missing: it properly marks a subtest as
'skipped' if the attached condition is not valid.

Without that, the test is wrongly marked as passed on older kernels.

Fixes: e06959e9ee ("selftests: mptcp: join: test for flush/re-add endpoints")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-2-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:46 -07:00
Matthieu Baerts (NGI0) e84cb860ac mptcp: pm: in-kernel: C-flag: handle late ADD_ADDR
The special C-flag case expects the ADD_ADDR to be received when
switching to 'fully-established'. But for various reasons, the ADD_ADDR
could be sent after the "4th ACK", and the special case doesn't work.

On NIPA, the new test validating this special case for the C-flag failed
a few times, e.g.

  102 default limits, server deny join id 0
        syn rx                 [FAIL] got 0 JOIN[s] syn rx expected 2

  Server ns stats
  (...)
  MPTcpExtAddAddrTx  1
  MPTcpExtEchoAdd    1

  Client ns stats
  (...)
  MPTcpExtAddAddr    1
  MPTcpExtEchoAddTx  1

        synack rx              [FAIL] got 0 JOIN[s] synack rx expected 2
        ack rx                 [FAIL] got 0 JOIN[s] ack rx expected 2
        join Rx                [FAIL] see above
        syn tx                 [FAIL] got 0 JOIN[s] syn tx expected 2
        join Tx                [FAIL] see above

I had a suspicion about what the issue could be: the ADD_ADDR might have
been received after the switch to the 'fully-established' state. The
issue was not easy to reproduce. The packet capture shown that the
ADD_ADDR can indeed be sent with a delay, and the client would not try
to establish subflows to it as expected.

A simple fix is not to mark the endpoints as 'used' in the C-flag case,
when looking at creating subflows to the remote initial IP address and
port. In this case, there is no need to try.

Note: newly added fullmesh endpoints will still continue to be used as
expected, thanks to the conditions behind mptcp_pm_add_addr_c_flag_case.

Fixes: 4b1ff850e0 ("mptcp: pm: in-kernel: usable client side with C-flag")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-1-8207030cb0e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21 17:36:45 -07:00
Matthieu Baerts (NGI0) c912f935a5 selftests: mptcp: join: validate new laminar endp
Here are a few sub-tests for mptcp_join.sh, validating the new 'laminar'
endpoint type.

In a setup where subflows created using the routing rules would be
rejected by the listener, and where the latter announces one IP address,
some cases are verified:

- Without any 'laminar' endpoints: no new subflows are created.

- With one 'laminar' endpoint: a second subflow is created.

- With multiple 'laminar' endpoints: 2 IPv4 subflows are created.

- With one 'laminar' endpoint, but the server announcing a second IP
  address, only one subflow is created.

- With one 'laminar' + 'subflow' endpoint, the same endpoint is only
  used once.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-8-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:36 -07:00
Matthieu Baerts (NGI0) 539f6b9de3 mptcp: pm: in-kernel: add laminar endpoints
Currently, upon the reception of an ADD_ADDR (and when the fullmesh flag
is not used), the in-kernel PM will create new subflows using the local
address the routing configuration will pick.

It would be easier to pick local addresses from a selected list of
endpoints, and use it only once, than relying on routing rules.

Use case: both the client (C) and the server (S) have two addresses (a
and b). The client establishes the connection between C(a) and S(a).
Once established, the server announces its additional address S(b). Once
received, the client connects to it using its second address C(b).
Compared to a situation without the 'laminar' endpoint for C(b), the
client didn't use this address C(b) to establish a subflow to the
server's primary address S(a). So at the end, we have:

   C        S
  C(a) --- S(a)
  C(b) --- S(b)

In case of a 3rd address on each side (C(c) and S(c)), upon the
reception of an ADD_ADDR with S(c), the client should not pick C(b)
because it has already been used. C(c) should then be used.

Note that this situation is currently possible if C doesn't add any
endpoint, but configure the routing in order to pick C(b) for the route
to S(b), and pick C(c) for the route to S(c). That doesn't sound very
practical because it means knowing in advance the IP addresses that
will be used and announced by the server.

'laminar', like the idea of laminar flows: the different subflows don't
mix with each other on an endpoint, unlike the "turbulent" way traffic
is mixed by 'fullmesh'.

In the code, the new endpoint type is added. Similar to the other
subflow types, an MPTCP_INFO counter is added. While at it, hole are now
commented in struct mptcp_info, to remember next time that these holes
can no longer be used.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/503
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-15-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) f596293314 mptcp: pm: in-kernel: compare IDs instead of addresses
When receiving an ADD_ADDR right after the 3WHS, the connection will
switch to 'fully established'. It means the MPTCP worker will be called
to treat two events, in this order: ADD_ADDR_RECEIVED, PM_ESTABLISHED.

The MPTCP endpoints cannot have the ID 0, because it is reserved to the
address and port used by the initial subflow. To be able to deal with
this case in different places, msk->mpc_endpoint_id contains the
endpoint ID linked to the initial subflow. This variable was only set
when treating the first PM_ESTABLISHED event, after ADD_ADDR_RECEIVED.
That's why in fill_local_addresses_vec(), the endpoint addresses were
compared with the one of the initial subflow, instead of only comparing
the IDs.

Instead, msk->mpc_endpoint_id is now set when treating ADD_ADDR_RECEIVED
as well, if needed, then the IDs can be compared.

To be able to do so, the code doing that is now in a dedicated helper,
and called from the functions linked to the two actions.

While at it, mptcp_endp_get_local_id() has also been moved up, next to
this new helper, because they are linked, and to be able to use it in
fill_local_addresses_vec() in the next commit.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-14-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) 4984fe6254 mptcp: pm: in-kernel: reduce pernet struct size
All the 'unsigned int' variables from the 'pm_nl_pernet' structure are
bounded to MPTCP_PM_ADDR_MAX, currently set to 8. The endpoint ID is
also bounded by the protocol to 8-bit. MPTCP_PM_ADDR_MAX, if extended
later, will never over 8-bit.

So no need to use 'unsigned int' variables, 'u8' is enough.

Note that the exposed counters in MPTCP_INFO are already limited to
8-bit, same for pm->extra_subflows, and others. So it seems even better
to limit them to 8-bit.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-13-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) db9a0e3858 mptcp: pm: in-kernel: remove stale_loss_cnt
It is currently not used.

It was in fact never used since its introduction in commit ff5a0b421c
("mptcp: faster active backup recovery"). It was probably initially
added to struct pm_nl_pernet during the development of this commit,
before being added to struct mptcp_pernet in ctrl.c, but not removed
from the first place.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-12-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) e9aa044f4a mptcp: pm: in-kernel: rename 'addrs' to 'endpoints'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'addrs', which in fact represents the number of declared
endpoints, and not only the 'signal' endpoints.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-11-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) 35e71e43a5 mptcp: pm: in-kernel: rename 'local_addr_list' to 'endp_list'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'local_addr_list', which in fact represents the list of
endpoints, and not only the 'subflow' endpoints.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-10-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) e7757b6d3a mptcp: pm: in-kernel: rename 'local_addr_max' to 'endp_subflow_max'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'local_addr_max', which in fact represents the maximum
number of 'subflow' endpoints that can be used to create new subflows,
and not the number of local addresses that have been used to create
subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_endp_subflow_max. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

Also move the variable and function next to the other 'endp_X_max' ones.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-9-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0) 37712d84df mptcp: pm: in-kernel: rename 'add_addr_accept_max' to 'limit_add_addr_accepted'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'add_addr_accept_max', which in fact represents the limit
of ADD_ADDR that can be accepted:  the limit set via 'ip mptcp limit
add_addr_accepted X' for example. It is not linked to the maximum number
of accepted ADD_ADDR.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_limit_add_addr_accepted. Not to break the current
uAPI, the new name is added as a 'define' pointing to the former name.
This will then also help userspace devs.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-8-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) 45cae57066 mptcp: pm: in-kernel: rename 'add_addr_signal_max' to 'endp_signal_max'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'add_addr_signal_max', which in fact represents the
maximum number of 'signal' endpoints that can be used to announced
addresses, and not the number of ADD_ADDR that can be signalled.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_endp_signal_max. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-7-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) 3eb3c9a959 mptcp: pm: in-kernel: rename 'subflows_max' to 'limit_extra_subflows'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'subflows_max', which in fact represents the limit of
extra subflows: the limit set via 'ip mptcp limit subflows X' for
example. It is not linked to the maximum number of created / possible
subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_limit_extra_subflows. Not to break the current uAPI,
the new name is added as a 'define' pointing to the former name. This
will then also help userspace devs.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-6-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) c5273f6ca1 mptcp: pm: rename 'subflows' to 'extra_subflows'
A few variables linked to the Path-Managers are confusing, and it would
help current and future developers, to clarify them.

One of them is 'subflows', which in fact represents the number of extra
subflows: all the additional subflows created after the initial one, and
not the total number of subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_extra_subflows. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-5-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) a845b2bbf2 mptcp: pm: in-kernel: refactor fill_remote_addresses_vec
Before this modification, this function was quite long with many levels
of indentations.

Each case can be split in a dedicated function: fullmesh, non-fullmesh.

To remove one level of indentation, msk->pm.subflows >= subflows_max is
now checked after having added one subflow, and stops the loop if it is
no longer possible to add new subflows. This is fine to do this because
this function should only be called if msk->pm.subflows < subflows_max.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-4-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) 8dc63ade45 mptcp: pm: in-kernel: refactor fill_local_addresses_vec
Before this modification, this function was quite long with many levels
of indentations.

Each case can be split in a dedicated function: fullmesh, C flag, any.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-3-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0) 008385efd0 selftests: mptcp: join: validate C-flag + def limit
The previous commit adds an exception for the C-flag case. The
'mptcp_join.sh' selftest is extended to validate this case.

In this subtest, there is a typical CDN deployment with a client where
MPTCP endpoints have been 'automatically' configured:

- the server set net.mptcp.allow_join_initial_addr_port=0

- the client has multiple 'subflow' endpoints, and the default limits:
  not accepting ADD_ADDRs.

Without the parent patch, the client is not able to establish new
subflows using its 'subflow' endpoints. The parent commit fixes that.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: df377be387 ("mptcp: add deny_join_id0 in mptcp_options_received")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-2-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:03 -07:00
Matthieu Baerts (NGI0) 4b1ff850e0 mptcp: pm: in-kernel: usable client side with C-flag
When servers set the C-flag in their MP_CAPABLE to tell clients not to
create subflows to the initial address and port, clients will likely not
use their other endpoints. That's because the in-kernel path-manager
uses the 'subflow' endpoints to create subflows only to the initial
address and port.

If the limits have not been modified to accept ADD_ADDR, the client
doesn't try to establish new subflows. If the limits accept ADD_ADDR,
the routing routes will be used to select the source IP.

The C-flag is typically set when the server is operating behind a legacy
Layer 4 load balancer, or using anycast IP address. Clients having their
different 'subflow' endpoints setup, don't end up creating multiple
subflows as expected, and causing some deployment issues.

A special case is then added here: when servers set the C-flag in the
MPC and directly sends an ADD_ADDR, this single ADD_ADDR is accepted.
The 'subflows' endpoints will then be used with this new remote IP and
port. This exception is only allowed when the ADD_ADDR is sent
immediately after the 3WHS, and makes the client switching to the 'fully
established' mode. After that, 'select_local_address()' will not be able
to find any subflows, because 'id_avail_bitmap' will be filled in
mptcp_pm_create_subflow_or_signal_addr(), when switching to 'fully
established' mode.

Fixes: df377be387 ("mptcp: add deny_join_id0 in mptcp_options_received")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/536
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-1-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:03 -07:00
Matthieu Baerts (NGI0) 1be5b82c45 mptcp: remove unused returned value of check_data_fin
When working on a fix modifying mptcp_check_data_fin(), I noticed the
returned value was no longer used.

It looks like it was used for 3 days, between commit 7ed90803a2
("mptcp: send explicit ack on delayed ack_seq incr") and commit
ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling").

This returned value can be safely removed.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-6-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:25 -07:00
Matthieu Baerts (NGI0) 5c967ebb55 mptcp: use _BITUL() instead of (1 << x)
Simply to use the proper way to declare bits, and to align with all
other flags declared in this file.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-5-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:25 -07:00
Matthieu Baerts (NGI0) e6c3552945 selftests: mptcp: pm: get server-side flag
server-side info linked to the MPTCP connect/established events can now
come from the flags, in addition to the dedicated attribute.

The attribute is now deprecated -- in favour of the new flag, and will
be removed later on.

Print this info only once.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-4-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:25 -07:00
Matthieu Baerts (NGI0) c8bc168f5f mptcp: pm: netlink: deprecate server-side attribute
Now that such info is in the 'flags' attribute, it is time to deprecate
the dedicated 'server-side' attribute.

It will be removed in a few versions.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-3-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:24 -07:00
Matthieu Baerts (NGI0) 3d7ae91107 mptcp: pm: netlink: announce server-side flag
Now that the 'flags' attribute is used, it seems interesting to add one
flag for 'server-side', a boolean value.

This is duplicating the info from the dedicated 'server-side' attribute,
but it will be deprecated in the next commit, and removed in a few
versions.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-2-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:24 -07:00
Matthieu Baerts (NGI0) c9809f03c1 mptcp: pm: netlink: only add server-side attr when true
This attribute is a boolean. No need to add it to set it to 'false'.

Indeed, the default value when this attribute is not set is naturally
'false'. A few bytes can then be saved by not adding this attribute if
the connection is not on the server side.

This prepares the future deprecation of its attribute, in favour of a
new flag.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-1-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:24 -07:00
Matthieu Baerts (NGI0) e1831e8dd1 scripts/decode_stacktrace.sh: code: preserve alignment
With lines having a code to decode, the alignment was not preserved for
the first line.

With this sample ...

  [   52.238089][   T55] RIP: 0010:__ip_queue_xmit+0x127c/0x1820
  [   52.238401][   T55] Code: c1 83 e0 07 48 c1 e9 03 83 c0 03 (...)

... the script was producing the following output:

  [   52.238089][   T55] RIP: 0010:__ip_queue_xmit (...)
  [ 52.238401][ T55] Code: c1 83 e0 07 48 c1 e9 03 83 c0 03 (...)

That's because scripts/decodecode doesn't preserve the alignment.  No need
to modify it, it is enough to give only the "Code: (...)" part to this
script, and print the prefix without modifications.

With the same sample, we now have:

  [   52.238089][   T55] RIP: 0010:__ip_queue_xmit (...)
  [   52.238401][   T55] Code: c1 83 e0 07 48 c1 e9 03 83 c0 03 (...)

Link: https://lkml.kernel.org/r/20250908-decode_strace_indent-v1-3-28e5e4758080@kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Tested-by: Carlos Llamas <cmllamas@google.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Elliot Berman <quic_eberman@quicinc.com>
Cc: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:28 -07:00
Matthieu Baerts (NGI0) 4a2fc4897b scripts/decode_stacktrace.sh: symbol: preserve alignment
With lines having a symbol to decode, the script was only trying to
preserve the alignment for the timestamps, but not the rest, nor when the
caller was set (CONFIG_PRINTK_CALLER=y).

With this sample ...

  [   52.080924] Call Trace:
  [   52.080926]  <TASK>
  [   52.080931]  dump_stack_lvl+0x6f/0xb0

... the script was producing the following output:

  [   52.080924] Call Trace:
  [   52.080926]  <TASK>
  [   52.080931] dump_stack_lvl (arch/x86/include/asm/irqflags.h:19)

  (dump_stack_lvl is no longer aligned with <TASK>: one missing space)

With this other sample ...

  [   52.080924][   T48] Call Trace:
  [   52.080926][   T48]  <TASK>
  [   52.080931][   T48]  dump_stack_lvl+0x6f/0xb0

... the script was producing the following output:

  [   52.080924][   T48] Call Trace:
  [   52.080926][   T48]  <TASK>
  [ 52.080931][ T48] dump_stack_lvl (arch/x86/include/asm/irqflags.h:19)

  (the misalignment is clearer here)

That's because the script had a workaround for CONFIG_PRINTK_TIME=y only,
see the previous comment called "Format timestamps with tabs".

To always preserve spaces, they need to be recorded along the words.  That
is what is now done with the new 'spaces' array.

Some notes:

- 'extglob' is needed only for this operation, and that's why it is set
  in a dedicated subshell.

- 'read' is used with '-r' not to treat a <backslash> character in any
  special way, e.g. when followed by a space.

- When a word is removed from the 'words' array, the corresponding space
  needs to be removed from the 'spaces' array as well.

With the last sample, we now have:

  [   52.080924][   T48] Call Trace:
  [   52.080926][   T48]  <TASK>
  [   52.080931][   T48]  dump_stack_lvl (arch/x86/include/asm/irqflags.h:19)

  (the alignment is preserved)

Link: https://lkml.kernel.org/r/20250908-decode_strace_indent-v1-2-28e5e4758080@kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Tested-by: Carlos Llamas <cmllamas@google.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Elliot Berman <quic_eberman@quicinc.com>
Cc: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:27 -07:00
Matthieu Baerts (NGI0) d322f6a24e scripts/decode_stacktrace.sh: symbol: avoid trailing whitespaces
A few patches slightly improving the output generated by
decode_stacktrace.sh.


This patch (of 3):

Lines having a symbol to decode might not always have info after this
symbol.  It means ${info_str} might not be set, but it will always be
printed after a space, causing trailing whitespaces.

That's a detail, but when the output is opened with an editor marking
these trailing whitespaces, that's a bit disturbing.  It is easy to remove
them by printing this variable with a space only if it is set.

While at it, do the same with ${module} and print everything in one line.

Link: https://lkml.kernel.org/r/20250908-decode_strace_indent-v1-0-28e5e4758080@kernel.org
Link: https://lkml.kernel.org/r/20250908-decode_strace_indent-v1-1-28e5e4758080@kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Elliot Berman <quic_eberman@quicinc.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:27 -07:00
Matthieu Baerts (NGI0) 833d4313bc mptcp: reset blackhole on success with non-loopback ifaces
When a first MPTCP connection gets successfully established after a
blackhole period, 'active_disable_times' was supposed to be reset when
this connection was done via any non-loopback interfaces.

Unfortunately, the opposite condition was checked: only reset when the
connection was established via a loopback interface. Fixing this by
simply looking at the opposite.

This is similar to what is done with TCP FastOpen, see
tcp_fastopen_active_disable_ofo_check().

This patch is a follow-up of a previous discussion linked to commit
893c49a78d ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in
mptcp_active_enable()."), see [1].

Fixes: 27069e7cb3 ("mptcp: disable active MPTCP in case of blackhole")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/4209a283-8822-47bd-95b7-87e96d9b7ea3@kernel.org [1]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250918-net-next-mptcp-blackhole-reset-loopback-v1-1-bf5818326639@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19 07:06:19 -07:00
Matthieu Baerts (NGI0) 12e74931ee netlink: specs: explicitly declare block scalar strings
In YAML, it is allowed to declare a scalar strings at the next lines
without explicitly declaring them as a block. Yet, they looks weird, and
can cause issues when ':' or '#' are present.

The modified lines didn't have issues with the special characters, but
it seems better to explicitly declare such blocks as scalar strings to
encourage people to "properly" declare future scalar strings.

The right angle bracket is used with a minus sign to indicate that the
folded style should be used without adding extra newlines. By doing
that, the output is not changed compared to what was done before this
patch.

Suggested-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250913-net-next-ynl-attr-doc-rst-v3-3-4f06420d87db@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-15 18:27:19 -07:00