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| author |   Oliver Hartkopp <oliver@hartkopp.net> | 2009-12-12 04:13:21 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2009-12-13 19:47:42 -0800 |
| commit | c7cd606f60e7679c7f9eee7010f02a6f000209c1 (patch) | |
| tree | 31c19fd7617ede807757b0ae5c29d218587dc43f /drivers/net/can/mscan/mscan.c | |
| parent | net: Fix userspace RTM_NEWLINK notifications. (diff) | |
| download | linux-dev-c7cd606f60e7679c7f9eee7010f02a6f000209c1.tar.xz linux-dev-c7cd606f60e7679c7f9eee7010f02a6f000209c1.zip | |
can: Fix data length code handling in rx path
A valid CAN dataframe can have a data length code (DLC) of 0 .. 8 data bytes.
When reading the CAN controllers register the 4-bit value may contain values
from 0 .. 15 which may exceed the reserved space in the socket buffer!
The ISO 11898-1 Chapter 8.4.2.3 (DLC field) says that register values > 8
should be reduced to 8 without any error reporting or frame drop.
This patch introduces a new helper macro to cast a given 4-bit data length
code (dlc) to __u8 and ensure the DLC value to be max. 8 bytes.
The different handlings in the rx path of the CAN netdevice drivers are fixed.
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/can/mscan/mscan.c')
| -rw-r--r-- | drivers/net/can/mscan/mscan.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c index bb06dfb58f25..07346f880ca6 100644 --- a/drivers/net/can/mscan/mscan.c +++ b/drivers/net/can/mscan/mscan.c @@ -297,7 +297,8 @@ static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame) frame->can_id |= can_id >> 1; if (can_id & 1) frame->can_id |= CAN_RTR_FLAG; - frame->can_dlc = in_8(®s->rx.dlr) & 0xf; + + frame->can_dlc = get_can_dlc(in_8(®s->rx.dlr) & 0xf); if (!(frame->can_id & CAN_RTR_FLAG)) { void __iomem *data = ®s->rx.dsr1_0; |