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     char payload_string[message->size * 2 + 1];
  25     memset(payload_string, 0, sizeof(payload_string));
  26     for(int i = 0; i < message->size; i++) {
  27         // TODO, bah this isn't working because snprintf hits the NULL char that
  28         // it wrote the last time and stops cold
  29         /* snprintf(&payload_string[i * 2], 2, "%02x", message->payload[i]); */
  30     }
  31     snprintf(destination, destination_length, "ID: 0x%02x, Payload: 0x%s",
  32             message->arbitration_id, payload_string);
  33 }
  34
  35 IsoTpMessage isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
  36         const uint16_t arbitration_id, const uint8_t data[],
  37         const uint8_t data_length) {
  38     IsoTpMessage message = {
  39         arbitration_id: arbitration_id,
  40         completed: false,
  41         payload: {0},
  42         size: 0
  43     };
  44
  45     if(data_length < 1) {
  46         return message;
  47     }
  48
  49     if(handle->type == ISOTP_HANDLE_RECEIVING) {
  50         if(handle->receive_handle.arbitration_id != arbitration_id) {
  51             if(shims->log != NULL)  {
  52                 shims->log("The arb ID 0x%x doesn't match the expected rx ID 0x%x",
  53                         arbitration_id, handle->receive_handle.arbitration_id);
  54             }
  55             return message;
  56         }
  57     } else if(handle->type == ISOTP_HANDLE_SENDING) {
  58         if(handle->send_handle.receiving_arbitration_id != arbitration_id) {
  59             if(shims->log != NULL) {
  60                 shims->log("The arb ID 0x%x doesn't match the expected tx continuation ID 0x%x",
  61                         arbitration_id, handle->send_handle.receiving_arbitration_id);
  62             }
  63             return message;
  64         }
  65     } else {
  66         shims->log("The ISO-TP handle is corrupt");
  67         return message;
  68     }
  69
  70     IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
  71             get_nibble(data, data_length, 0);
  72
  73     uint8_t payload_length = get_nibble(data, data_length, 1);
  74     uint8_t payload[payload_length];
  75     if(payload_length > 0 && data_length > 0) {
  76         memcpy(payload, &data[1], payload_length);
  77     }
  78
  79     // TODO this is set up to handle rx a response with a payload, but not to
  80     // handle flow control responses for multi frame messages that we're in the
  81     // process of sending
  82
  83     switch(pci) {
  84         case PCI_SINGLE: {
  85             if(payload_length > 0) {
  86                 memcpy(message.payload, payload, payload_length);
  87             }
  88             message.size = payload_length;
  89             message.completed = true;
  90             handle->success = true;
  91             handle->completed = true;
  92             isotp_handle_single_frame(handle, &message);
  93             break;
  94          }
  95         default:
  96             shims->log("Only single frame messages are supported");
  97             break;
  98     }
  99     return message;
 100 }