[PATCH mptcp-next v4 0/3] only remove entry from local_addr_list when sending a REMOVE_ADDR

[PATCH mptcp-next v4 0/3] only remove entry from local_addr_list when sending a REMOVE_ADDR

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

v4:
 - rebased.

v3:
 - update userspace selftests.
 - Link: https://patchwork.kernel.org/project/mptcp/cover/cover.1744787273.git.tanggeliang@kylinos.cn/

v2:
 - squash patch 1 into patch 2 as Mat suggested.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/403

Geliang Tang (3):
  mptcp: pm: userspace: drop delete_local_addr helper
  selftests: mptcp: join: update userspace dump_addr outputs
  selftests: mptcp: userspace: send RM_ADDR between server and client

 net/mptcp/pm_userspace.c                      | 37 +++----------------
 .../testing/selftests/net/mptcp/mptcp_join.sh |  6 +--
 .../selftests/net/mptcp/userspace_pm.sh       | 12 ++++++
 3 files changed, 20 insertions(+), 35 deletions(-)

-- 
2.51.0

[PATCH mptcp-next v4 1/3] mptcp: pm: userspace: drop delete_local_addr helper

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Address entries should not be removed from local_addr_list when a subflow
is deleted by the userspace PM, should only be removed when sending a
REMOVE_ADDR.

So mptcp_userspace_pm_delete_local_addr() helper shouldn't be called in
mptcp_pm_nl_subflow_create_doit() and mptcp_pm_nl_subflow_destroy_doit().

Since this helper is open-coding in mptcp_pm_nl_remove_doit(), it can be
dropped now.

Address entries are removed from local_addr_list when sending a REMOVE_ADDR
by the userspace PM, the local_addr_used counter of PM should also be
decremented accordingly.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/403
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_userspace.c | 37 +++++--------------------------------
 1 file changed, 5 insertions(+), 32 deletions(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index d838e8ea65fd..b33c883aec98 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -90,30 +90,6 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 	return ret;
 }
 
-/* If the subflow is closed from the other peer (not via a
- * subflow destroy command then), we want to keep the entry
- * not to assign the same ID to another address and to be
- * able to send RM_ADDR after the removal of the subflow.
- */
-static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
-						struct mptcp_pm_addr_entry *addr)
-{
-	struct sock *sk = (struct sock *)msk;
-	struct mptcp_pm_addr_entry *entry;
-
-	entry = mptcp_userspace_pm_lookup_addr(msk, &addr->addr);
-	if (!entry)
-		return -EINVAL;
-
-	/* TODO: a refcount is needed because the entry can
-	 * be used multiple times (e.g. fullmesh mode).
-	 */
-	list_del_rcu(&entry->list);
-	sock_kfree_s(sk, entry, sizeof(*entry));
-	msk->pm.local_addr_used--;
-	return 0;
-}
-
 static struct mptcp_pm_addr_entry *
 mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 {
@@ -331,6 +307,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	list_del_rcu(&match->list);
+	msk->pm.local_addr_used--;
 	spin_unlock_bh(&msk->pm.lock);
 
 	mptcp_pm_remove_addr_entry(msk, match);
@@ -412,14 +389,13 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 	err = __mptcp_subflow_connect(sk, &local, &addr_r);
 	release_sock(sk);
 
-	if (err)
+	if (err) {
 		GENL_SET_ERR_MSG_FMT(info, "connect error: %d", err);
+		goto create_err;
+	}
 
 	spin_lock_bh(&msk->pm.lock);
-	if (err)
-		mptcp_userspace_pm_delete_local_addr(msk, &entry);
-	else
-		msk->pm.extra_subflows++;
+	msk->pm.extra_subflows++;
 	spin_unlock_bh(&msk->pm.lock);
 
  create_err:
@@ -538,9 +514,6 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 		goto release_sock;
 	}
 
-	spin_lock_bh(&msk->pm.lock);
-	mptcp_userspace_pm_delete_local_addr(msk, &addr_l);
-	spin_unlock_bh(&msk->pm.lock);
 	mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 	mptcp_close_ssk(sk, ssk, mptcp_subflow_ctx(ssk));
 	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
-- 
2.51.0

[PATCH mptcp-next v4 2/3] selftests: mptcp: join: update userspace dump_addr outputs

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Now address entries only be removed from local_addr_list when sending a
REMOVE_ADDR by the userspace PM, they're no longer removed when a subflow
is deleted.

To make userspace PM selftests in mptcp_join.sh pass, this patch updates
the outputs of dump_addr.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index beec41f6662a..9802a991892d 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -4034,9 +4034,9 @@ userspace_tests()
 		userspace_pm_chk_get_addr "${ns1}" "20" "id 20 flags signal 10.0.3.1"
 		userspace_pm_rm_sf $ns1 "::ffff:10.0.2.1" $MPTCP_LIB_EVENT_SUB_ESTABLISHED
 		userspace_pm_chk_dump_addr "${ns1}" \
-			"id 20 flags signal 10.0.3.1" "after rm_sf 10"
+			$'id 10 flags signal 10.0.2.1\nid 20 flags signal 10.0.3.1' "after rm_sf 10"
 		userspace_pm_rm_addr $ns1 20
-		userspace_pm_chk_dump_addr "${ns1}" "" "after rm_addr 20"
+		userspace_pm_chk_dump_addr "${ns1}" "id 10 flags signal 10.0.2.1" "after rm_addr 20"
 		chk_rm_nr 1 1 invert
 		chk_mptcp_info subflows 0 subflows 0
 		chk_subflows_total 1 1
@@ -4064,7 +4064,7 @@ userspace_tests()
 		userspace_pm_chk_get_addr "${ns2}" "20" "id 20 flags subflow 10.0.3.2"
 		userspace_pm_rm_sf $ns2 10.0.3.2 $MPTCP_LIB_EVENT_SUB_ESTABLISHED
 		userspace_pm_chk_dump_addr "${ns2}" \
-			"" \
+			"id 20 flags subflow 10.0.3.2" \
 			"after rm_sf 20"
 		chk_rm_nr 0 1
 		chk_mptcp_info subflows 0 subflows 0
-- 
2.51.0

[PATCH mptcp-next v4 3/3] selftests: mptcp: userspace: send RM_ADDR between server and client

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Now address entries only be removed from local_addr_list when sending a
REMOVE_ADDR by the userspace PM, they're no longer removed when a subflow
is deleted.

To make the original userspace PM selftests pass, this patch sends RM_ADDR
from server to client machine at the end of each test, and always sends
RM_ADDR from client to server machine to cleanup address IDs for the next
new test.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/net/mptcp/userspace_pm.sh | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/userspace_pm.sh b/tools/testing/selftests/net/mptcp/userspace_pm.sh
index e9ae1806ab07..7490b80b3e45 100755
--- a/tools/testing/selftests/net/mptcp/userspace_pm.sh
+++ b/tools/testing/selftests/net/mptcp/userspace_pm.sh
@@ -642,6 +642,8 @@ test_subflows()
 			      "dead:beef:2::1" "dead:beef:2::2" "$client6_port" "23"\
 			      "$client_addr_id" "ns1" "ns2"
 
+	# RM_ADDR from server to client machine
+	ip netns exec "$ns1" ./pm_nl_ctl rem id 23 token "$server6_token"
 	# RM_ADDR from client to server machine
 	ip netns exec "$ns2" ./pm_nl_ctl rem id $client_addr_id token\
 	   "$client6_token"
@@ -680,6 +682,8 @@ test_subflows()
 	verify_subflow_events "$server_evts" "$SUB_CLOSED" "$server4_token" "$AF_INET" "10.0.2.1"\
 			      "10.0.2.2" "$new4_port" "23" "$client_addr_id" "ns1" "ns2"
 
+	# RM_ADDR from server to client machine
+	ip netns exec "$ns1" ./pm_nl_ctl rem id 23 token "$server4_token"
 	# RM_ADDR from client to server machine
 	ip netns exec "$ns2" ./pm_nl_ctl rem id $client_addr_id token\
 	   "$client4_token"
@@ -721,6 +725,8 @@ test_subflows()
 	# RM_ADDR from server to client machine
 	ip netns exec "$ns1" ./pm_nl_ctl rem id $server_addr_id token\
 	   "$server4_token"
+	# RM_ADDR from client to server machine
+	ip netns exec "$ns2" ./pm_nl_ctl rem id 23 token "$client4_token"
 	sleep 0.5
 
 	# Attempt to add a listener at dead:beef:2::1:<subflow-port>
@@ -760,6 +766,8 @@ test_subflows()
 	# RM_ADDR6 from server to client machine
 	ip netns exec "$ns1" ./pm_nl_ctl rem id $server_addr_id token\
 	   "$server6_token"
+	# RM_ADDR6 from client to server machine
+	ip netns exec "$ns2" ./pm_nl_ctl rem id 23 token "$client6_token"
 	sleep 0.5
 
 	# Attempt to add a listener at 10.0.2.1:<new-port>
@@ -797,6 +805,8 @@ test_subflows()
 	# RM_ADDR from server to client machine
 	ip netns exec "$ns1" ./pm_nl_ctl rem id $server_addr_id token\
 	   "$server4_token"
+	# RM_ADDR from client to server machine
+	ip netns exec "$ns2" ./pm_nl_ctl rem id 23 token "$client4_token"
 }
 
 test_subflows_v4_v6_mix()
@@ -844,6 +854,8 @@ test_subflows_v4_v6_mix()
 	# RM_ADDR from server to client machine
 	ip netns exec "$ns1" ./pm_nl_ctl rem id $server_addr_id token\
 	   "$server6_token"
+	# RM_ADDR from client to server machine
+	ip netns exec "$ns2" ./pm_nl_ctl rem id 23 token "$client6_token"
 	sleep 0.5
 }
 
-- 
2.51.0

Re: [PATCH mptcp-next v4 0/3] only remove entry from local_addr_list when sending a REMOVE_ADDR

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/24591044565

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/df304e308870
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1082700


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

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

For more details:

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


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

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

Re: [PATCH mptcp-next v4 0/3] only remove entry from local_addr_list when sending a REMOVE_ADDR

[Matthieu Baerts]

Hi Geliang,

On 18/04/2026 09:06, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> v4:
>  - rebased.
Thank you for the v4. The modification looks good to me, even if the
behaviour is slightly different:

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Note that Sashiko is saying that a RM_ADDR from the server to the client
is maybe needed:

  https://sashiko.dev/#/patchset/cover.1776466833.git.tanggeliang@kylinos.cn

Not sure: it doesn't seem to cause issues for the other tests.

When you have a chance, can you validate that mptcpd tests (make check)
are still OK after this modification?

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