src/isotp/receive.c

   1 #include <isotp/receive.h>
   2 #include <bitfield/bitfield.h>
   3 #include <string.h>
   4
   5 static void isotp_complete_receive(IsoTpReceiveHandle* handle, IsoTpMessage* message) {
   6     if(handle->message_received_callback != NULL) {
   7         handle->message_received_callback(message);
   8     }
   9 }
  10
  11 bool isotp_handle_single_frame(IsoTpReceiveHandle* handle, IsoTpMessage* message) {
  12     isotp_complete_receive(handle, message);
  13     return true;
  14 }
  15
  16 IsoTpReceiveHandle isotp_receive(IsoTpShims* shims,
  17         const uint32_t arbitration_id, IsoTpMessageReceivedHandler callback) {
  18     IsoTpReceiveHandle handle = {
  19         success: false,
  20         completed: false,
  21         arbitration_id: arbitration_id,
  22         message_received_callback: callback
  23     };
  24
  25     return handle;
  26 }
  27
  28 IsoTpMessage isotp_continue_receive(IsoTpShims* shims,
  29         IsoTpReceiveHandle* handle, const uint32_t arbitration_id,
  30         const uint8_t data[], const uint8_t size) {
  31     IsoTpMessage message = {
  32         arbitration_id: arbitration_id,
  33         completed: false,
  34         payload: {0},
  35         size: 0
  36     };
  37
  38     if(size < 1) {
  39         return message;
  40     }
  41
  42     if(handle->arbitration_id != arbitration_id) {
  43         if(shims->log != NULL)  {
  44             // You may turn this on for debugging, but in normal operation it's
  45             // very noisy if you are passing all received CAN messages to this
  46             // handler.
  47             /* shims->log("The arb ID 0x%x doesn't match the expected rx ID 0x%x", */
  48                     /* arbitration_id, handle->arbitration_id); */
  49         }
  50         return message;
  51     }
  52
  53     IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
  54             get_nibble(data, size, 0);
  55
  56     uint8_t payload_length = get_nibble(data, size, 1);
  57     uint8_t payload[payload_length];
  58     if(payload_length > 0 && size > 0) {
  59         memcpy(payload, &data[1], payload_length);
  60     }
  61
  62     // TODO this is set up to handle rx a response with a payload, but not to
  63     // handle flow control responses for multi frame messages that we're in the
  64     // process of sending
  65
  66     switch(pci) {
  67         case PCI_SINGLE: {
  68             if(payload_length > 0) {
  69                 memcpy(message.payload, payload, payload_length);
  70             }
  71             message.size = payload_length;
  72             message.completed = true;
  73             handle->success = true;
  74             handle->completed = true;
  75             isotp_handle_single_frame(handle, &message);
  76             break;
  77          }
  78         default:
  79             shims->log("Only single frame messages are supported");
  80             break;
  81     }
  82     return message;
  83 }