Can message forwarding for panda

Can_message_forwarding.h

// added this at the end of CAN_RX()

// make a copy
    CAN_FIFOMailBox_TypeDef tx_to_push;
    tx_to_push.RDHR = to_push.RDHR;
    tx_to_push.RDLR = to_push.RDLR;
    tx_to_push.RDTR = to_push.RDTR;
    tx_to_push.RIR = to_push.RIR;

    int flags = (tx_to_push.RDTR >> 4) & 0xF;
    CAN_TypeDef *CANTX;
    can_ring *can_q;
    int can_number;
    set_led(LED_GREEN, 1);
    if (flags == can_numbering[0] && (((tx_to_push.RIR >> 21) & 0x7FF) == 0x33d)) {
        set_led(LED_GREEN,1);
            CANTX = CAN2;
            can_q = &can_tx2_q;
            tx_to_push.RIR = 0;
            tx_to_push.RIR |= ((unsigned int)(0x400000 << 3)) | ((uint32_t)0x00000004);
            // add CAN packet to send queue
            // bus number isn't passed through
            tx_to_push.RDTR &= 0xF;
            push(can_q, &tx_to_push);

            // flags = can_number
            process_can(CANTX, can_q, flags);
    }

// changed this portion in process_can()
// check for empty mailbox
  CAN_FIFOMailBox_TypeDef to_send;
  if ((CAN->TSR & CAN_TSR_TME0) == CAN_TSR_TME0) {
    if (pop(can_q, &to_send)) {
      // only send if we have received a packet
      CAN->sTxMailBox[0].TDLR = to_send.RDLR;
      CAN->sTxMailBox[0].TDHR = to_send.RDHR;
      CAN->sTxMailBox[0].TDTR = to_send.RDTR;
      CAN->sTxMailBox[0].TIR = to_send.RIR;
      CAN->IER |= CAN_IER_TMEIE;                      // enable  TME interrupt 
      CAN->sTxMailBox[0].TIR |= ((unsigned long)0x00000001);       // transmit message
    }
  }