Generating Classical CAN frames with raw DLC values greater than 8 is an
expert feature that should only be enabled on demand.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
ISO 11898-1 Chapter 8.4.2.3 defines a 4 bit data length code (DLC) table which
maps the DLC to the payload length of the CAN frame in bytes:
DLC -> payload length
0 .. 8 -> 0 .. 8
9 .. 15 -> 8
Although the DLC values 8 .. 15 in Classical CAN always result in a payload
length of 8 bytes these DLC values are transparently transmitted on the CAN
bus.
To access the raw DLC values 9 .. 15 the len8_dlc element is introduced, which
is only valid when the payload length 'len' is 8 and the DLC is greater than 8.
The extension for len8_dlc has been implemented for the Classic CAN frame
representation in the log file format and analogue for cansend.
cangen can now randomly generate Classic CAN DLC values from 0 .. 15.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
ISO 11898-1 Chapter 8.4.2.3 defines a 4 bit data length code (DLC) table which
maps the DLC to the payload length of the CAN frame in bytes:
DLC -> payload length
0 .. 8 -> 0 .. 8
9 .. 15 -> 8
Although the DLC values 8 .. 15 in Classical CAN always result in a payload
length of 8 bytes these DLC values are transparently transmitted on the CAN
bus. As the struct can_frame only provides a 'len' element (formerly 'can_dlc')
which contains the plain payload length ( 0 .. 8 ) of the CAN frame, the raw
DLC is not visible to the application programmer, e.g. for testing use-cases.
To access the raw DLC values 9 .. 15 the len8_dlc element is introduced, which
is only valid when the payload length 'len' is 8 and the DLC is greater than 8.
The len8_dlc element is filled by the CAN interface driver and used for CAN
frame creation by the CAN driver when the CAN_CTRLMODE_CC_LEN8_DLC flag is
supported by the driver and enabled via netlink configuration interface.
Reported-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
The PTX flavour canutils have a useful utility for generating a sequence of CAN
frames with an incrementing payload and checking such a sequence for missed and
reordered frames.
Recently, it has helped finding a regression in the kernel pfifo_fast qdisc,
which led to reordered frames.
To bring the utility to a greater audience, import the current state, including
its history, into the linux-can set of utilities.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes the indention, which was broken while renaming the j1939
tools.
Fixes: 8106214b55 ("Rename j* to j1939\1")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Without this, the extended identifier flag was not important when
filtering on CAN frames. Add this to mask to only receive the frame type
we want to recieve.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
- added poll support if sender
- add cmd line option for can_id
- setup canfilter to disable receiving in sender mode
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Oliver Hartkopp
Marc Kleine-Budde
Sascha Hauer
Rosen Penev