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
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 for the standard output for
candump where the raw DLC value is printed in 'unusual' curly braces {}.
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>
This patch fixes the following warning:
cansequence.c:232:3: warning: expression result unused [-Wunused-value]
(unsigned char)frame.data[0]++;
^ ~~~~~~~~~~~~~~~
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Otherwise throwing the following error:
build/make/core/base_rules.mk:325: error: external/can-utils:
MODULE.TARGET.EXECUTABLES.cansequence already defined by
external/can-utils.
Fixes: a726c2a ("Merge branch 'cansequence' of
github.com:marckleinebudde/can-utils into master")
Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
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
Rosen Penev
Gary Bisson
Sascha Hauer