can: j1939: extend UAPI to notify about RX status

To be able to create applications with user friendly feedback, we need be
able to provide receive status information.

Typical ETP transfer may take seconds or even hours. To give user some
clue or show a progress bar, the stack should push status updates.
Same as for the TX information, the socket error queue will be used with
following new signals:
- J1939_EE_INFO_RX_RTS   - received and accepted request to send signal.
- J1939_EE_INFO_RX_DPO   - received data package offset signal
- J1939_EE_INFO_RX_ABORT - RX session was aborted

Instead of completion signal, user will get data package.
To activate this signals, application should set
SOF_TIMESTAMPING_RX_SOFTWARE to the SO_TIMESTAMPING socket option. This
will avoid unpredictable application behavior for the old software.

Link: https://lore.kernel.org/r/20210707094854.30781-3-o.rempel@pengutronix.de
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 18 insertions, 4 deletions

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 801e700eaba6..bb5c4b8979be 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -260,10 +260,14 @@ static void __j1939_session_drop(struct j1939_session *session)
 
 static void j1939_session_destroy(struct j1939_session *session)
 {
-	if (session->err)
-		j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT);
-	else
-		j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ACK);
+	if (session->transmission) {
+		if (session->err)
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT);
+		else
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ACK);
+	} else if (session->err) {
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
+	}
 
 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 
@@ -1116,6 +1120,8 @@ static void __j1939_session_cancel(struct j1939_session *session,
 
 	if (session->sk)
 		j1939_sk_send_loop_abort(session->sk, session->err);
+	else
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
 }
 
 static void j1939_session_cancel(struct j1939_session *session,
@@ -1330,6 +1336,8 @@ static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
 	session->err = j1939_xtp_abort_to_errno(priv, abort);
 	if (session->sk)
 		j1939_sk_send_loop_abort(session->sk, session->err);
+	else
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
 	j1939_session_deactivate_activate_next(session);
 
 abort_put:
@@ -1630,6 +1638,9 @@ j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
 	session->pkt.rx = 0;
 	session->pkt.tx = 0;
 
+	session->tskey = priv->rx_tskey++;
+	j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_RTS);
+
 	WARN_ON_ONCE(j1939_session_activate(session));
 
 	return session;
@@ -1752,6 +1763,9 @@ static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
 	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
 	session->last_cmd = dat[0];
 	j1939_tp_set_rxtimeout(session, 750);
+
+	if (!session->transmission)
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_DPO);
 }
 
 static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,