[PATCH mptcp-net v5 11/13] mptcp: pm: reuse ID 0 after delete and re-add

Matthieu Baerts (NGI0) posted 13 patches 1 month, 3 weeks ago
[PATCH mptcp-net v5 11/13] mptcp: pm: reuse ID 0 after delete and re-add
Posted by Matthieu Baerts (NGI0) 1 month, 3 weeks ago
When the endpoint used by the initial subflow is removed and re-added
later, the PM has to force the ID 0, it is a special case imposed by the
MPTCP specs.

Note that the endpoint should then need to be re-added reusing the same
ID.

Fixes: 3ad14f54bd74 ("mptcp: more accurate MPC endpoint tracking")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Notes:
  - v5:
    - Add missing 'ID' in comment (Mat)
---
 net/mptcp/pm_netlink.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 0dacf16a4b53..36e179f1f888 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -585,6 +585,11 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 
 		__clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
 		msk->pm.add_addr_signaled++;
+
+		/* Special case for ID0: set the correct ID */
+		if (local.addr.id == msk->mpc_endpoint_id)
+			local.addr.id = 0;
+
 		mptcp_pm_announce_addr(msk, &local.addr, false);
 		mptcp_pm_nl_addr_send_ack(msk);
 
@@ -613,6 +618,10 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 		if (nr == 0)
 			continue;
 
+		/* Special case for ID0: set the correct ID */
+		if (local.addr.id == msk->mpc_endpoint_id)
+			local.addr.id = 0;
+
 		spin_unlock_bh(&msk->pm.lock);
 		for (i = 0; i < nr; i++)
 			__mptcp_subflow_connect(sk, &local.addr, &addrs[i]);

-- 
2.45.2