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authorOliver Hartkopp <oliver@hartkopp.net>2009-12-12 04:13:21 +0000
committerDavid S. Miller <davem@davemloft.net>2009-12-13 19:47:42 -0800
commitc7cd606f60e7679c7f9eee7010f02a6f000209c1 (patch)
tree31c19fd7617ede807757b0ae5c29d218587dc43f /drivers/net/can/mscan
parentd90a909e1f3e006a1d57fe11fd417173b6494701 (diff)
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')
-rw-r--r--drivers/net/can/mscan/mscan.c3
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(&regs->rx.dlr) & 0xf;
+
+ frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
if (!(frame->can_id & CAN_RTR_FLAG)) {
void __iomem *data = &regs->rx.dsr1_0;