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mptcp: fix active subflow finalization

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Active subflow are inserted into the connection list at creation time.
When the MPJ handshake completes successfully, a new subflow creation
netlink event is generated correctly, but the current code wrongly
avoid initializing a couple of subflow data.

The above will cause misbehavior on a few exceptional events: unneeded
mptcp-level retransmission on msk-level sequence wrap-around and infinite
mapping fallback even when a MPJ socket is present.

Address the issue factoring out the needed initialization in a new helper
and invoking the latter from __mptcp_finish_join() time for passive
subflow and from mptcp_finish_join() for active ones.

Fixes: 0530020a7c8f ("mptcp: track and update contiguous data status")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Paolo Abeni 2023-05-31 12:37:08 -07:00 committed by Jakub Kicinski
parent 6b9831bfd9
commit 55b47ca7d8
1 changed files with 14 additions and 9 deletions
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23
net/mptcp/protocol.c
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@ -825,6 +825,13 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk)
mptcp_data_unlock(sk);
}
static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
{
mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
WRITE_ONCE(msk->allow_infinite_fallback, false);
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
}
static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
{
struct sock *sk = (struct sock *)msk;
@ -839,6 +846,7 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
mptcp_sock_graft(ssk, sk->sk_socket);
mptcp_sockopt_sync_locked(msk, ssk);
mptcp_subflow_joined(msk, ssk);
return true;
}
@ -3485,14 +3493,16 @@ bool mptcp_finish_join(struct sock *ssk)
return false;
}
if (!list_empty(&subflow->node))
goto out;
/* active subflow, already present inside the conn_list */
if (!list_empty(&subflow->node)) {
mptcp_subflow_joined(msk, ssk);
return true;
}
if (!mptcp_pm_allow_new_subflow(msk))
goto err_prohibited;
/* active connections are already on conn_list.
* If we can't acquire msk socket lock here, let the release callback
/* If we can't acquire msk socket lock here, let the release callback
* handle it
*/
mptcp_data_lock(parent);
@ -3515,11 +3525,6 @@ err_prohibited:
return false;
}
subflow->map_seq = READ_ONCE(msk->ack_seq);
WRITE_ONCE(msk->allow_infinite_fallback, false);
out:
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
return true;
}