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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/usb | |
| parent | d90a909e1f3e006a1d57fe11fd417173b6494701 (diff) | |
| download | op-kernel-dev-c7cd606f60e7679c7f9eee7010f02a6f000209c1.zip op-kernel-dev-c7cd606f60e7679c7f9eee7010f02a6f000209c1.tar.gz | |
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/usb')
| -rw-r--r-- | drivers/net/can/usb/ems_usb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 591eb0eb..efbb05c7 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -316,7 +316,7 @@ static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) return; cf->can_id = le32_to_cpu(msg->msg.can_msg.id); - cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8); + cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) |
