Hi Oleksij,
On 18/12/2019 09.43, Oleksij Rempel wrote:
In current J1939 stack implementation, we process all locally send
messages as own messages. Even if it was send by CAN_RAW socket.
To reproduce it use following commands:
testj1939 -P -r can0:0x80 &
cansend can0 18238040#0123
This step will trigger false positive not critical warning:
j1939_simple_recv: Received already invalidated message
With this patch we add additional check to make sure, related skb is own
echo message.
in net/can/raw.c we check whether the CAN has been sent from that socket
(an by default suppress our own transmitted data):
https://elixir.bootlin.com/linux/v5.4.3/source/net/can/raw.c#L124
would checking against the 'sk' work for you too?
What happens if someone runs a J1939 implementation on a CAN_RAW socket
in addition to the in-kernel implementation? Can they talk to each other?
Regards,
Oliver
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
net/can/j1939/socket.c | 1 +
net/can/j1939/transport.c | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index f7587428febd..b9a17c2ee16f 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -398,6 +398,7 @@ static int j1939_sk_init(struct sock *sk)
spin_lock_init(&jsk->sk_session_queue_lock);
INIT_LIST_HEAD(&jsk->sk_session_queue);
sk->sk_destruct = j1939_sk_sock_destruct;
+ sk->sk_protocol = CAN_J1939;
return 0;
}
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 9f99af5b0b11..b135c5e2a86e 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -2017,6 +2017,10 @@ void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
if (!skb->sk)
return;
+ if (skb->sk->sk_family != AF_CAN ||
+ skb->sk->sk_protocol != CAN_J1939)
+ return;
+
j1939_session_list_lock(priv);
session = j1939_session_get_simple(priv, skb);
j1939_session_list_unlock(priv);
