Commit 833d4313 authored by Matthieu Baerts (NGI0)'s avatar Matthieu Baerts (NGI0) Committed by Jakub Kicinski
Browse files

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
893c49a7 ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in
mptcp_active_enable()."), see [1].

Fixes: 27069e7c ("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: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250918-net-next-mptcp-blackhole-reset-loopback-v1-1-bf5818326639@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c4bdef8b

net/mptcp/ctrl.c

+1 −1
Original line number Diff line number Diff line
@@ -507,7 +507,7 @@ void mptcp_active_enable(struct sock *sk) 
		rcu_read_lock();

		dst = __sk_dst_get(sk);

		dev = dst ? dst_dev_rcu(dst) : NULL;

		if (dev && (dev->flags & IFF_LOOPBACK))

		if (!(dev && (dev->flags & IFF_LOOPBACK)))

			atomic_set(&pernet->active_disable_times, 0);

		rcu_read_unlock();

	}