[PATCH v1 24/34] j1939: transport: wait for abort packet before complete session

[Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>]

Wait for abort on CAN bus before starting new session. If we will
not wait, we will abort next, fresh new session by accident.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
 net/can/j1939/j1939-priv.h |  5 ++++-
 net/can/j1939/transport.c  | 17 +++++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/net/can/j1939/j1939-priv.h b/net/can/j1939/j1939-priv.h
index 1e470a394fff..4c6365804de1 100644
--- a/net/can/j1939/j1939-priv.h
+++ b/net/can/j1939/j1939-priv.h
@@ -9,7 +9,10 @@
 #include <linux/can/j1939.h>
 #include <net/sock.h>
 
-/* TODO: return ENETRESET on busoff. */
+/* Timeout to receive the abort signal over loop back. In case CAN
+ * bus is open, the timeout should be triggered.
+ */
+#define J1939_XTP_ABORT_TIMEOUT_MS 500
 
 struct j1939_session;
 enum j1939_sk_errqueue_type {
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index aaf9bf9fd90e..79233f7884cc 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -957,10 +957,12 @@ static void j1939_session_cancel(struct j1939_session *session,
 
 	session->err = j1939_xtp_abort_to_errno(priv, err);
 	/* do not send aborts on incoming broadcasts */
-	if (!j1939_cb_is_broadcast(&session->skcb))
+	if (!j1939_cb_is_broadcast(&session->skcb)) {
+		session->state = J1939_SESSION_WAITING_ABORT;
 		j1939_xtp_tx_abort(priv, &session->skcb,
 				   !j1939_tp_im_transmitter(&session->skcb),
 				   err, session->skcb.addr.pgn);
+	}
 
 	if (session->sk)
 		j1939_sk_send_loop_abort(priv, session->sk, session->err);
@@ -1012,8 +1014,11 @@ static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
 	} else if (ret) {
 		netdev_alert(priv->ndev, "%s: tx aborted with unknown reason: %i\n",
 			     __func__, ret);
-		if (session->skcb.addr.type != J1939_SIMPLE)
+		if (session->skcb.addr.type != J1939_SIMPLE) {
+			j1939_tp_set_rxtimeout(session,
+					       J1939_XTP_ABORT_TIMEOUT_MS);
 			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
+		}
 	} else {
 		session->tx_retry = 0;
 	}
@@ -1052,9 +1057,9 @@ static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
 		j1939_session_list_lock(session->priv);
 		if (session->state >= J1939_SESSION_ACTIVE &&
 		    session->state < J1939_SESSION_ACTIVE_MAX) {
-			session->state = J1939_SESSION_WAITING_ABORT;
 			j1939_session_get(session);
-			hrtimer_start(&session->rxtimer, ms_to_ktime(1250),
+			hrtimer_start(&session->rxtimer,
+				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
 				      HRTIMER_MODE_REL_SOFT);
 			j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
 		}
@@ -1226,6 +1231,7 @@ j1939_xtp_rx_cts(struct j1939_session *session, struct sk_buff *skb)
  out_session_unlock:
 	j1939_session_unlock(session);
 	j1939_session_timers_cancel(session);
+	j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
 	j1939_session_cancel(session, err);
 }
 
@@ -1404,6 +1410,7 @@ static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
 
 		/* RTS on active session */
 		j1939_session_timers_cancel(session);
+		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
 	}
 
@@ -1414,6 +1421,7 @@ static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
 			     session->last_cmd);
 
 		j1939_session_timers_cancel(session);
+		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
 
 		return -EBUSY;
@@ -1544,6 +1552,7 @@ static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
 	j1939_session_unlock(session);
  out_session_cancel:
 	j1939_session_timers_cancel(session);
+	j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
 	j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
 	j1939_session_put(session);
 }
-- 
2.20.1