Hi all,
just for the records:
I did some tests with the cangw tool from
https://github.com/linux-can/can-utils where I removed some sanity
checks (6,7) in parse_mod() to be able to reproduce Muyu's setup.
The filters are configured as follows:
# cangw -L
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.41.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:401.40.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.3F.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.9.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:301.8.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.7.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.41.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:201.40.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.3F.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:102.9.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:101.8.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:100.7.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 0 deleted
After sending a Classic CAN frame DLC of 1:
$ cansend vcan0 001#22
candump produces this:
$ candump -ta any
(1546606529.898372) vcan0 001 [1] 22
(1546606529.898830) vcan1 301 [8] 22 00 00 00 00 00 00 00
(1546606529.898921) vcan1 300 [7] 22 00 00 00 00 00 00
(1546606529.899308) vcan1 101 [8] 22 00 00 00 00 00 22 00
(1546606529.899399) vcan1 100 [7] 22 00 00 00 00 22 00
And the handled and deleted frames are counted as follows:
# cangw -L
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.41.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:401.40.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.3F.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.9.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:301.8.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.7.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.41.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:201.40.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.3F.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:102.9.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:101.8.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:100.7.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 1 handled 0 dropped 0 deleted
So all modified DLC values that did not fit into the frame lead to
deleted CAN frames.
When sending a CAN FD frame with DLC of 1 as an alternative:
$ cansend vcan0 001##022
candump produces this:
$ candump -ta any
(1546607375.109495) vcan0 001 [01] 22
(1546607375.109749) vcan1 401 [64] 22 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00
(1546607375.109850) vcan1 400 [63] 22 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00
(1546607375.109949) vcan1 300 [09] 22 00 00 00 00 00 00 00 00
(1546607375.110049) vcan1 301 [08] 22 00 00 00 00 00 00 00
(1546607375.110148) vcan1 300 [07] 22 00 00 00 00 00 00
(1546607375.110574) vcan1 101 [08] 22 00 00 00 00 00 22 00
(1546607375.110674) vcan1 100 [07] 22 00 00 00 00 22 00
And the handled and deleted frames are counted as follows:
# cangw -L
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.41.0000000000000000 -f
001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:401.40.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:400.3F.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.9.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:301.8.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:300.7.0000000000000000 -f
001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.41.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:201.40.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:200.3F.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:102.9.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 0 handled 0 dropped 1 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:101.8.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 1 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e -m SET:IL:100.7.0000000000000000 -x
-6:0:-2:00 -f 001:C00007FF # 1 handled 0 dropped 0 deleted
Here you can see the additional effect of deleting frames with a dlc > 8
that are configured to calculate a checksum.
So finally all new code paths of the patch have been triggered and do
the intended stuff.
Best regards,
Oliver
