Commit 3f83d8a7 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

mptcp: fix more tx path fields initialization 



The 'msk->write_seq' and 'msk->snd_nxt' are always updated under
the msk socket lock, except at MPC handshake completiont time.

Builds-up on the previous commit to move such init under the relevant
lock.

There are no known problems caused by the potential race, the
primary goal is consistency.

Fixes: 6d0060f6 ("mptcp: Write MPTCP DSS headers to outgoing data packets")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 013e3179

net/mptcp/protocol.c

+2 −4
Original line number Diff line number Diff line
@@ -3478,10 +3478,8 @@ void mptcp_finish_connect(struct sock *ssk) 
	 * accessing the field below

	 */

	WRITE_ONCE(msk->local_key, subflow->local_key);

	WRITE_ONCE(msk->write_seq, subflow->idsn + 1);

	WRITE_ONCE(msk->snd_nxt, msk->write_seq);

	WRITE_ONCE(msk->snd_una, msk->write_seq);

	WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);

	WRITE_ONCE(msk->snd_una, subflow->idsn + 1);

	WRITE_ONCE(msk->wnd_end, subflow->idsn + 1 + tcp_sk(ssk)->snd_wnd);



	mptcp_pm_new_connection(msk, ssk, 0);

}

net/mptcp/subflow.c

+11 −2
Original line number Diff line number Diff line
@@ -421,12 +421,21 @@ static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct soc 


void __mptcp_sync_state(struct sock *sk, int state)

{

	struct mptcp_subflow_context *subflow;

	struct mptcp_sock *msk = mptcp_sk(sk);

	struct sock *ssk = msk->first;



	__mptcp_propagate_sndbuf(sk, msk->first);

	subflow = mptcp_subflow_ctx(ssk);

	__mptcp_propagate_sndbuf(sk, ssk);

	if (!msk->rcvspace_init)

		mptcp_rcv_space_init(msk, msk->first);

		mptcp_rcv_space_init(msk, ssk);



	if (sk->sk_state == TCP_SYN_SENT) {

		/* subflow->idsn is always available is TCP_SYN_SENT state,

		 * even for the FASTOPEN scenarios

		 */

		WRITE_ONCE(msk->write_seq, subflow->idsn + 1);

		WRITE_ONCE(msk->snd_nxt, msk->write_seq);

		mptcp_set_state(sk, state);

		sk->sk_state_change(sk);

	}