Post #2201245

2026-05-07 10:20 UTC

regret to inform you have I learned more about SocketCAN filtering options. can.h:21 /* special address description flags for the CAN_ID */ #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */ #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */ #define CAN_ERR_FLAG 0x20000000U /* error message frame */ can.h:160 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */ careful readers may notice a problem (edit: ok apparently one of those goes in the mask, not the can_id field. That's on me, but also what the heck.)

Replies (1)

@barometz@social.treehouse.systems 2026-05-07 10:23

now admittedly we are using it wrong; normally you could simply not set any filters and the default behaviour would be what you want: all actual frames, no thousands of error frames. Unfortunately we've hardcoded the number of filters into this and changing that would be tricky at this stage.

Open ##2201246