[PATCH 5.8 092/148] can: j1939: fix support for multipacket broadcast message

Greg Kroah-Hartman
2020-08-24T08:37:20Z

From: Zhang Changzhong <zhangchangzhong@huawei.com>

[ Upstream commit f4fd77fd87e9b214c26bb2ebd4f90055eaea5ade ]

Currently j1939_tp_im_involved_anydir() in j1939_tp_recv() check the previously
set flags J1939_ECU_LOCAL_DST and J1939_ECU_LOCAL_SRC of incoming skb, thus
multipacket broadcast message was aborted by receive side because it may come
from remote ECUs and have no exact dst address. Similarly, j1939_tp_cmd_recv()
and j1939_xtp_rx_dat() didn't process broadcast message.

So fix it by checking and process broadcast message in j1939_tp_recv(),
j1939_tp_cmd_recv() and j1939_xtp_rx_dat().

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1596599425-5534-2-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/can/j1939/transport.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 90a2baac8a4aa..67189b4c482c5 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1673,8 +1673,12 @@ static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
return;
}
session = j1939_xtp_rx_rts_session_new(priv, skb);
- if (!session)
+ if (!session) {
+ if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
+ netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
+ __func__);
return;
+ }
} else {
if (j1939_xtp_rx_rts_session_active(session, skb)) {
j1939_session_put(session);
@@ -1852,6 +1856,13 @@ static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
else
j1939_xtp_rx_dat_one(session, skb);
}
+
+ if (j1939_cb_is_broadcast(skcb)) {
+ session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+ false);
+ if (session)
+ j1939_xtp_rx_dat_one(session, skb);
+ }
}

/* j1939 main intf */
@@ -1943,7 +1954,7 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_rts(priv, skb, true);

- if (j1939_tp_im_receiver(skcb))
+ if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
j1939_xtp_rx_rts(priv, skb, false);

break;
@@ -2007,7 +2018,7 @@ int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);

- if (!j1939_tp_im_involved_anydir(skcb))
+ if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
return 0;

switch (skcb->addr.pgn) {
--
2.25.1