Commit 825199bf authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-various-small-improvements' 

Matthieu Baerts says:

====================
mptcp: various small improvements

The following patches are not related to each other.

- Patch 1: Avoid sending advertisements on stale subflows, reducing
  risks on loosing them.

- Patch 2: Annotate data-races around subflow->fully_established, using
  READ/WRITE_ONCE().

- Patch 3: A small clean-up on the PM side, avoiding a bit of duplicated
  code.

- Patch 4: Use "Middlebox interference" MP_TCPRST code in reaction to a
  packet received without MPTCP options in the middle of a connection.
====================

Link: https://patch.msgid.link/20241021-net-next-mptcp-misc-6-13-v1-0-1ef02746504a@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents fbb26ecc 46a3282b

net/mptcp/diag.c

+1 −1
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ static int subflow_get_info(struct sock *sk, struct sk_buff *skb) 
		flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM;

	if (sf->request_bkup)

		flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC;

	if (sf->fully_established)

	if (READ_ONCE(sf->fully_established))

		flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED;

	if (sf->conn_finished)

		flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;

net/mptcp/options.c

+2 −2
Original line number Diff line number Diff line
@@ -461,7 +461,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, 
		return false;



	/* MPC/MPJ needed only on 3rd ack packet, DATA_FIN and TCP shutdown take precedence */

	if (subflow->fully_established || snd_data_fin_enable ||

	if (READ_ONCE(subflow->fully_established) || snd_data_fin_enable ||

	    subflow->snd_isn != TCP_SKB_CB(skb)->seq ||

	    sk->sk_state != TCP_ESTABLISHED)

		return false;
@@ -930,7 +930,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, 
	/* here we can process OoO, in-window pkts, only in-sequence 4th ack

	 * will make the subflow fully established

	 */

	if (likely(subflow->fully_established)) {

	if (likely(READ_ONCE(subflow->fully_established))) {

		/* on passive sockets, check for 3rd ack retransmission

		 * note that msk is always set by subflow_syn_recv_sock()

		 * for mp_join subflows

net/mptcp/pm.c

+3 −0
Original line number Diff line number Diff line
@@ -154,6 +154,9 @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk) 
void mptcp_pm_connection_closed(struct mptcp_sock *msk)

{

	pr_debug("msk=%p\n", msk);



	if (msk->token)

		mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);

}



void mptcp_pm_subflow_established(struct mptcp_sock *msk)

net/mptcp/pm_netlink.c

+11 −3
Original line number Diff line number Diff line
@@ -781,7 +781,7 @@ bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk, 


void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)

{

	struct mptcp_subflow_context *subflow;

	struct mptcp_subflow_context *subflow, *alt = NULL;



	msk_owned_by_me(msk);

	lockdep_assert_held(&msk->pm.lock);
@@ -792,10 +792,18 @@ void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk) 


	mptcp_for_each_subflow(msk, subflow) {

		if (__mptcp_subflow_active(subflow)) {

			if (!subflow->stale) {

				mptcp_pm_send_ack(msk, subflow, false, false);

			break;

				return;

			}



			if (!alt)

				alt = subflow;

		}

	}



	if (alt)

		mptcp_pm_send_ack(msk, alt, false, false);

}



int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,

net/mptcp/protocol.c

+3 −5
Original line number Diff line number Diff line
@@ -3139,8 +3139,7 @@ bool __mptcp_close(struct sock *sk, long timeout) 


	sock_hold(sk);

	pr_debug("msk=%p state=%d\n", sk, sk->sk_state);

	if (msk->token)

		mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);

	mptcp_pm_connection_closed(msk);



	if (sk->sk_state == TCP_CLOSE) {

		__mptcp_destroy_sock(sk);
@@ -3206,8 +3205,7 @@ static int mptcp_disconnect(struct sock *sk, int flags) 
	mptcp_stop_rtx_timer(sk);

	mptcp_stop_tout_timer(sk);



	if (msk->token)

		mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);

	mptcp_pm_connection_closed(msk);



	/* msk->subflow is still intact, the following will not free the first

	 * subflow
@@ -3511,7 +3509,7 @@ static void schedule_3rdack_retransmission(struct sock *ssk) 
	struct tcp_sock *tp = tcp_sk(ssk);

	unsigned long timeout;



	if (mptcp_subflow_ctx(ssk)->fully_established)

	if (READ_ONCE(mptcp_subflow_ctx(ssk)->fully_established))

		return;



	/* reschedule with a timeout above RTT, as we must look only for drop */