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[net,00/15] mptcp: more fixes for the in-kernel PM

Message ID 20240826-net-mptcp-more-pm-fix-v1-0-8cd6c87d1d6d@kernel.org
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Series mptcp: more fixes for the in-kernel PM | expand

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Matthieu Baerts (NGI0) Aug. 26, 2024, 3:58 p.m. UTC
Here is a new batch of fixes for the MPTCP in-kernel path-manager:

Patch 1 ensures the address ID is set to 0 when the path-manager sends
an ADD_ADDR for the address of the initial subflow. The same fix is
applied when a new subflow is created re-using this special address. A
fix for v6.0.

Patch 2 is similar, but for the case where an endpoint is removed: if
this endpoint was used for the initial address, it is important to send
a RM_ADDR with this ID set to 0, and look for existing subflows with the
ID set to 0. A fix for v6.0 as well.

Patch 3 validates the two previous patches.

Patch 4 makes the PM selecting an "active" path to send an address
notification in an ACK, instead of taking the first path in the list. A
fix for v5.11.

Patch 5 fixes skipping the establishment of a new subflow if a previous
subflow using the same pair of addresses is being closed. A fix for
v5.13.

Patch 6 resets the ID linked to the initial subflow when the linked
endpoint is re-added, possibly with a different ID. A fix for v6.0.

Patch 7 validates the three previous patches.

Patch 8 is a small fix for the MPTCP Join selftest, when being used with
older subflows not supporting all MIB counters. A fix for a commit
introduced in v6.4, but backported up to v5.10.

Patch 9 avoids the PM to try to close the initial subflow multiple
times, and increment counters while nothing happened. A fix for v5.10.

Patch 10 stops incrementing local_addr_used and add_addr_accepted
counters when dealing with the address ID 0, because these counters are
not taking into account the initial subflow, and are then not
decremented when the linked addresses are removed. A fix for v6.0.

Patch 11 validates the previous patch.

Patch 12 avoids the PM to send multiple SUB_CLOSED events for the
initial subflow. A fix for v5.12.

Patch 13 validates the previous patch.

Patch 14 stops treating the ADD_ADDR 0 as a new address, and accepts it
in order to re-create the initial subflow if it has been closed, even if
the limit for *new* addresses -- not taking into account the address of
the initial subflow -- has been reached. A fix for v5.10.

Patch 15 validates the previous patch.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Matthieu Baerts (NGI0) (15):
      mptcp: pm: reuse ID 0 after delete and re-add
      mptcp: pm: fix RM_ADDR ID for the initial subflow
      selftests: mptcp: join: check removing ID 0 endpoint
      mptcp: pm: send ACK on an active subflow
      mptcp: pm: skip connecting to already established sf
      mptcp: pm: reset MPC endp ID when re-added
      selftests: mptcp: join: check re-adding init endp with != id
      selftests: mptcp: join: no extra msg if no counter
      mptcp: pm: do not remove already closed subflows
      mptcp: pm: fix ID 0 endp usage after multiple re-creations
      selftests: mptcp: join: check re-re-adding ID 0 endp
      mptcp: avoid duplicated SUB_CLOSED events
      selftests: mptcp: join: validate event numbers
      mptcp: pm: ADD_ADDR 0 is not a new address
      selftests: mptcp: join: check re-re-adding ID 0 signal

 net/mptcp/pm.c                                  |   4 +-
 net/mptcp/pm_netlink.c                          |  87 ++++++++++----
 net/mptcp/protocol.c                            |   6 +
 net/mptcp/protocol.h                            |   5 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 149 ++++++++++++++++++++----
 tools/testing/selftests/net/mptcp/mptcp_lib.sh  |   4 +
 6 files changed, 207 insertions(+), 48 deletions(-)
---
base-commit: 8af174ea863c72f25ce31cee3baad8a301c0cf0f
change-id: 20240826-net-mptcp-more-pm-fix-ffa61a36f817

Best regards,

Comments

Matthieu Baerts (NGI0) Aug. 27, 2024, 8:22 a.m. UTC | #1
Hi Jakub,

On 27/08/2024 04:29, Jakub Kicinski wrote:
> On Mon, 26 Aug 2024 17:58:59 +0200 Matthieu Baerts (NGI0) wrote:
>> Matthieu Baerts (NGI0) (15):
>>       mptcp: pm: reuse ID 0 after delete and re-add
>>       mptcp: pm: fix RM_ADDR ID for the initial subflow
>>       selftests: mptcp: join: check removing ID 0 endpoint
>>       mptcp: pm: send ACK on an active subflow
>>       mptcp: pm: skip connecting to already established sf
>>       mptcp: pm: reset MPC endp ID when re-added
>>       selftests: mptcp: join: check re-adding init endp with != id
>>       selftests: mptcp: join: no extra msg if no counter
>>       mptcp: pm: do not remove already closed subflows
>>       mptcp: pm: fix ID 0 endp usage after multiple re-creations
>>       selftests: mptcp: join: check re-re-adding ID 0 endp
>>       mptcp: avoid duplicated SUB_CLOSED events
>>       selftests: mptcp: join: validate event numbers
>>       mptcp: pm: ADD_ADDR 0 is not a new address
>>       selftests: mptcp: join: check re-re-adding ID 0 signal
> 
> The debug runner is failing mptcp-join-sh fairly consistently with
> these applied :(

Thank you for this notification!

It looks like the patch "selftests: mptcp: join: check re-re-adding ID 0
endp" is making the "delete and re-add" subtest longer: the connection
finishes while the validation is still ongoing. I guess I didn't see
this issue on my side, nor on MPTCP CI, because the Netdev CI is slower
(SLUB_DEBUG_ON?).

It is easy to fix, but I will wait for the other MPTCP series to be
applied, before sending a v2.

Cheers,
Matt