Toolbox Usage

I was just going through the CAN code for MCB2300 provided by Keil and there i saw that the toolbox can enable/disable loopback. This was done using the CAN_Simulate.ini.
Im trying to do the same for my project on LPC1778.
What im not able to understand is what is CAN1OUT,CAN1B0,CAN1B1 etc in the .ini.
Any references for understanding how the .ini file was written,so that I can do the same for my project would be useful.

/*----------------------------------------------------------------------------*/
/* CAN_loopback_1_to_2() simulates loopback connection from CAN1 to CAN2 port */
/*----------------------------------------------------------------------------*/

signal void CAN_loopback_1_to_2 (void) {
  while (1) {
    wwatch(CAN1OUT);
    CAN2ID = CAN1ID;
    CAN2B0 = CAN1B0; CAN2B1 = CAN1B1; CAN2B2 = CAN1B2; CAN2B3 = CAN1B3;
    CAN2B4 = CAN1B4; CAN2B5 = CAN1B5; CAN2B6 = CAN1B6; CAN2B7 = CAN1B7;
    CAN2L  = CAN1L;
    CAN2IN = CAN1OUT;
  }
}

/*----------------------------------------------------------------------------*/
/* CAN_loopback_2_to_1() simulates loopback connection from CAN2 to CAN1 port */
/*----------------------------------------------------------------------------*/

signal void CAN_loopback_2_to_1 (void) {
  while (1) {
    wwatch(CAN2OUT);
    CAN1ID = CAN2ID;
    CAN1B0 = CAN2B0; CAN1B1 = CAN2B1; CAN1B2 = CAN2B2; CAN1B3 = CAN2B3;
    CAN1B4 = CAN2B4; CAN1B5 = CAN2B5; CAN1B6 = CAN2B6; CAN1B7 = CAN2B7;
    CAN1L  = CAN2L;
    CAN1IN = CAN2OUT;
  }
}