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authorOleksij Rempel <o.rempel@pengutronix.de>2020-08-07 12:52:00 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2020-08-14 12:38:47 +0200
commite052d0540298bfe0f6cbbecdc7e2ea9b859575b2 (patch)
treee433a91b95c486e4c8b7e6c4a738e67fa8f3bd0c /net/can
parent840835c9281215341d84966a8855f267a971e6a3 (diff)
can: j1939: transport: j1939_xtp_rx_dat_one(): compare own packets to detect corruptions
Since the stack relays on receiving own packets, it was overwriting own transmit buffer from received packets. At least theoretically, the received echo buffer can be corrupt or changed and the session partner can request to resend previous data. In this case we will re-send bad data. With this patch we will stop to overwrite own TX buffer and use it for sanity checking. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20200807105200.26441-6-o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/j1939/transport.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 90a2baac8a4a..5cf107cb447c 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1792,7 +1792,20 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
}
tpdat = se_skb->data;
- memcpy(&tpdat[offset], &dat[1], nbytes);
+ if (!session->transmission) {
+ memcpy(&tpdat[offset], &dat[1], nbytes);
+ } else {
+ int err;
+
+ err = memcmp(&tpdat[offset], &dat[1], nbytes);
+ if (err)
+ netdev_err_once(priv->ndev,
+ "%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
+ __func__, session,
+ nbytes, &dat[1],
+ nbytes, &tpdat[offset]);
+ }
+
if (packet == session->pkt.rx)
session->pkt.rx++;