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authorOliver Hartkopp <socketcan@hartkopp.net>2014-03-01 15:31:53 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-03-03 14:29:52 +0100
commit821047c4055cca833c4674f172a9d73003563eb6 (patch)
tree28246c9f50757df9ea1efcad0c8210f098aa1c14 /net/can
parent4b5b82274a17f0ebbf02378df2ba7f36a3f5af19 (diff)
can: remove CAN FD compatibility for CAN 2.0 sockets
In commit e2d265d3b587 (canfd: add support for CAN FD in CAN_RAW sockets) CAN FD frames with a payload length up to 8 byte are passed to legacy sockets where the CAN FD support was not enabled by the application. After some discussions with developers at a fair this well meant feature leads to confusion as no clean switch for CAN / CAN FD is provided to the application programmer. Additionally a compatibility like this for legacy CAN_RAW sockets requires some compatibility handling for the sending, e.g. make CAN2.0 frames a CAN FD frame with BRS at transmission time (?!?). This will become a mess when people start to develop applications with real CAN FD hardware. This patch reverts the bad compatibility code together with the documentation describing the removed feature. Acked-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/raw.c26
1 files changed, 5 insertions, 21 deletions
diff --git a/net/can/raw.c b/net/can/raw.c
index 8be757cca2ec..081e81fd017f 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -121,13 +121,9 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
if (!ro->recv_own_msgs && oskb->sk == sk)
return;
- /* do not pass frames with DLC > 8 to a legacy socket */
- if (!ro->fd_frames) {
- struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
-
- if (unlikely(cfd->len > CAN_MAX_DLEN))
- return;
- }
+ /* do not pass non-CAN2.0 frames to a legacy socket */
+ if (!ro->fd_frames && oskb->len != CAN_MTU)
+ return;
/* clone the given skb to be able to enqueue it into the rcv queue */
skb = skb_clone(oskb, GFP_ATOMIC);
@@ -738,9 +734,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t size, int flags)
{
struct sock *sk = sock->sk;
- struct raw_sock *ro = raw_sk(sk);
struct sk_buff *skb;
- int rxmtu;
int err = 0;
int noblock;
@@ -751,20 +745,10 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
if (!skb)
return err;
- /*
- * when serving a legacy socket the DLC <= 8 is already checked inside
- * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
- * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
- */
- if (!ro->fd_frames)
- rxmtu = CAN_MTU;
- else
- rxmtu = skb->len;
-
- if (size < rxmtu)
+ if (size < skb->len)
msg->msg_flags |= MSG_TRUNC;
else
- size = rxmtu;
+ size = skb->len;
err = memcpy_toiovec(msg->msg_iov, skb->data, size);
if (err < 0) {

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