Arduino canbus buffer read messages at multiple rates and using masks and filters

How can the individual canbus buffers for the arduino be accessed from the simulink code?

I have 1 can message which arrives at 0.01s, and the rest (about 20 messages) are arriving at 0.1s period, I am not able to reliably read the slow messages and would like to use 1 buffer for the fast message using the masks but there is no documentation for the arduino library.