src/isotp/isotp.c

   1 #include <isotp/isotp.h>
   2 #include <isotp/receive.h>
   3 #include <bitfield/bitfield.h>
   4
   5 const uint16_t MAX_ISO_TP_MESSAGE_SIZE = 4096;
   6 const uint16_t MAX_CAN_FRAME_SIZE = 8;
   7 const uint8_t ISO_TP_DEFAULT_RESPONSE_TIMEOUT = 100;
   8 const bool ISO_TP_DEFAULT_FRAME_PADDING_STATUS = true;
   9
  10 // TODO why isn't this picked up from the header?
  11 extern IsoTpHandle isotp_receive(IsoTpShims* shims, const uint16_t arbitration_id,
  12         IsoTpMessageReceivedHandler callback);
  13
  14
  15 /* void isotp_set_timeout(IsoTpHandler* handler, uint16_t timeout_ms) { */
  16     /* handler->timeout_ms = timeout_ms; */
  17 /* } */
  18
  19 IsoTpShims isotp_init_shims(LogShim log, SendCanMessageShim send_can_message,
  20         SetTimerShim set_timer) {
  21     IsoTpShims shims = {
  22         log: log,
  23         send_can_message: send_can_message,
  24         set_timer: set_timer
  25     };
  26     return shims;
  27 }
  28
  29 void isotp_message_to_string(const IsoTpMessage* message, char* destination,
  30         size_t destination_length) {
  31     snprintf(destination, destination_length,"ID: 0x%02x, Payload: 0x%llx",
  32             // TODO the payload may be backwards here
  33             message->arbitration_id, message->payload);
  34 }
  35
  36 void isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
  37         const uint16_t arbitration_id, const uint8_t data[],
  38         const uint8_t data_length) {
  39     if(data_length < 1) {
  40         return;
  41     }
  42
  43     if(handle->type == ISOTP_HANDLE_RECEIVING) {
  44         if(handle->receive_handle.arbitration_id != arbitration_id) {
  45             return;
  46         }
  47     } else if(handle->type == ISOTP_HANDLE_SENDING) {
  48         if(handle->send_handle.receiving_arbitration_id != arbitration_id) {
  49             return;
  50         }
  51     } else {
  52         shims->log("The ISO-TP handle is corrupt");
  53     }
  54
  55     IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
  56             get_nibble(data, data_length, 0);
  57
  58     uint8_t payload_length = get_nibble(data, data_length, 1);
  59     uint8_t payload[payload_length];
  60     if(payload_length > 0 && data_length > 0) {
  61         memcpy(payload, &data[1], payload_length);
  62     }
  63
  64     // TODO this is set up to handle rx a response with a payload, but not to
  65     // handle flow control responses for multi frame messages that we're in the
  66     // process of sending
  67
  68     switch(pci) {
  69         case PCI_SINGLE: {
  70             IsoTpMessage message = {
  71                 arbitration_id: arbitration_id,
  72                 payload: payload,
  73                 size: payload_length
  74             };
  75
  76             isotp_handle_single_frame(handle, &message);
  77             break;
  78          }
  79         default:
  80             shims->log("Only single frame messages are supported");
  81             break;
  82     }
  83 }