src/isotp/isotp.c

   1 #include <isotp/isotp.h>
   2 #include <isotp/receive.h>
   3 #include <bitfield/bitfield.h>
   4
   5 const uint8_t ISO_TP_DEFAULT_RESPONSE_TIMEOUT = 100;
   6 const bool ISO_TP_DEFAULT_FRAME_PADDING_STATUS = true;
   7
   8 /* void isotp_set_timeout(IsoTpHandler* handler, uint16_t timeout_ms) { */
   9     /* handler->timeout_ms = timeout_ms; */
  10 /* } */
  11
  12 IsoTpShims isotp_init_shims(LogShim log, SendCanMessageShim send_can_message,
  13         SetTimerShim set_timer) {
  14     IsoTpShims shims = {
  15         log: log,
  16         send_can_message: send_can_message,
  17         set_timer: set_timer
  18     };
  19     return shims;
  20 }
  21
  22 void isotp_message_to_string(const IsoTpMessage* message, char* destination,
  23         size_t destination_length) {
  24     snprintf(destination, destination_length, "ID: 0x%02x, Payload: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
  25             message->arbitration_id,
  26             message->payload[0],
  27             message->payload[1],
  28             message->payload[2],
  29             message->payload[3],
  30             message->payload[4],
  31             message->payload[5],
  32             message->payload[6],
  33             message->payload[7]);
  34 }
  35
  36 IsoTpMessage 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     IsoTpMessage message = {
  40         arbitration_id: arbitration_id,
  41         completed: false,
  42         payload: {0},
  43         size: 0
  44     };
  45
  46     if(data_length < 1) {
  47         return message;
  48     }
  49
  50     if(handle->type == ISOTP_HANDLE_RECEIVING) {
  51         if(handle->receive_handle.arbitration_id != arbitration_id) {
  52             if(shims->log != NULL)  {
  53                 shims->log("The arb ID 0x%x doesn't match the expected rx ID 0x%x",
  54                         arbitration_id, handle->receive_handle.arbitration_id);
  55             }
  56             return message;
  57         }
  58     } else if(handle->type == ISOTP_HANDLE_SENDING) {
  59         // TODO this will need to be tested when we add multi-frame support,
  60         // which is when it'll be necessary to pass in CAN messages to SENDING
  61         // handles.
  62         if(handle->send_handle.receiving_arbitration_id != arbitration_id) {
  63             if(shims->log != NULL) {
  64                 shims->log("The arb ID 0x%x doesn't match the expected tx continuation ID 0x%x",
  65                         arbitration_id, handle->send_handle.receiving_arbitration_id);
  66             }
  67             return message;
  68         }
  69     } else {
  70         shims->log("The ISO-TP handle is corrupt");
  71         return message;
  72     }
  73
  74     IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
  75             get_nibble(data, data_length, 0);
  76
  77     uint8_t payload_length = get_nibble(data, data_length, 1);
  78     uint8_t payload[payload_length];
  79     if(payload_length > 0 && data_length > 0) {
  80         memcpy(payload, &data[1], payload_length);
  81     }
  82
  83     // TODO this is set up to handle rx a response with a payload, but not to
  84     // handle flow control responses for multi frame messages that we're in the
  85     // process of sending
  86
  87     switch(pci) {
  88         case PCI_SINGLE: {
  89             if(payload_length > 0) {
  90                 memcpy(message.payload, payload, payload_length);
  91             }
  92             message.size = payload_length;
  93             message.completed = true;
  94             handle->success = true;
  95             handle->completed = true;
  96             isotp_handle_single_frame(handle, &message);
  97             break;
  98          }
  99         default:
 100             shims->log("Only single frame messages are supported");
 101             break;
 102     }
 103     return message;
 104 }