#include #include #define ARBITRATION_ID_OFFSET 0x8 #define MODE_RESPONSE_OFFSET 0x40 #define NEGATIVE_RESPONSE_MODE 0x7f #define MAX_DIAGNOSTIC_PAYLOAD_SIZE 6 #define MODE_BYTE_INDEX 0 #define PID_BYTE_INDEX 1 #define NEGATIVE_RESPONSE_MODE_INDEX 1 #define NEGATIVE_RESPONSE_NRC_INDEX 2 DiagnosticShims diagnostic_init_shims(LogShim log, SendCanMessageShim send_can_message, SetTimerShim set_timer) { DiagnosticShims shims = { log: log, send_can_message: send_can_message, set_timer: set_timer }; return shims; } DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims, DiagnosticRequest* request, DiagnosticResponseReceived callback) { DiagnosticRequestHandle handle = { request: *request, callback: callback, success: false, completed: false }; uint8_t payload[MAX_DIAGNOSTIC_PAYLOAD_SIZE]; payload[MODE_BYTE_INDEX] = request->mode; if(request->pid_length > 0) { copy_bytes_right_aligned(&request->pid, sizeof(request->pid), PID_BYTE_INDEX, request->pid_length, payload, sizeof(payload)); } if(request->payload_length > 0) { memcpy(&payload[PID_BYTE_INDEX + request->pid_length], request->payload, request->payload_length); } handle.isotp_shims = isotp_init_shims(shims->log, shims->send_can_message, shims->set_timer); handle.isotp_send_handle = isotp_send(&handle.isotp_shims, request->arbitration_id, payload, 1 + request->payload_length + request->pid_length, NULL); handle.isotp_receive_handle = isotp_receive(&handle.isotp_shims, request->arbitration_id + ARBITRATION_ID_OFFSET, NULL); // TODO notes on multi frame: // TODO what are the timers for exactly? // // when sending multi frame, send 1 frame, wait for a response // if it says send all, send all right away // if it says flow control, set the time for the next send // instead of creating a timer with an async callback, add a process_handle // function that's called repeatedly in the main loop - if it's time to // send, we do it. so there's a process_handle_send and receive_can_frame // that are just called continuously from the main loop. it's a waste of a // few cpu cycles but it may be more natural than callbacks. // // what woudl a timer callback look like...it would need to pass the handle // and that's all. seems like a context void* would be able to capture all // of the information but arg, memory allocation. look at how it's done in // the other library again // return handle; } DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims, DiagnosticPidRequestType pid_request_type, uint16_t arbitration_id, uint16_t pid, DiagnosticResponseReceived callback) { DiagnosticRequest request = { arbitration_id: arbitration_id, mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22, pid: pid, pid_length: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 1 : 2 }; return diagnostic_request(shims, &request, callback); } static bool handle_negative_response(IsoTpMessage* message, DiagnosticResponse* response, DiagnosticShims* shims) { bool response_was_negative = false; if(response->mode == NEGATIVE_RESPONSE_MODE) { response_was_negative = true; if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) { response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX]; } if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) { response->negative_response_code = message->payload[NEGATIVE_RESPONSE_NRC_INDEX]; } response->success = false; response->completed = true; } return response_was_negative; } static bool handle_positive_response(DiagnosticRequestHandle* handle, IsoTpMessage* message, DiagnosticResponse* response, DiagnosticShims* shims) { bool response_was_positive = false; if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) { response_was_positive = true; // hide the "response" version of the mode from the user // if it matched response->mode = handle->request.mode; if(handle->request.pid_length > 0 && message->size > 1) { if(handle->request.pid_length == 2) { response->pid = *(uint16_t*)&message->payload[PID_BYTE_INDEX]; response->pid = ntohs(response->pid); } else { response->pid = message->payload[PID_BYTE_INDEX]; } } uint8_t payload_index = 1 + handle->request.pid_length; response->payload_length = message->size - payload_index; if(response->payload_length > 0) { memcpy(response->payload, &message->payload[payload_index], response->payload_length); } response->success = true; response->completed = true; } return response_was_positive; } DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims, DiagnosticRequestHandle* handle, const uint16_t arbitration_id, const uint8_t data[], const uint8_t size) { DiagnosticResponse response = { arbitration_id: arbitration_id, success: false, completed: false }; if(!handle->isotp_send_handle.completed) { isotp_continue_send(&handle->isotp_shims, &handle->isotp_send_handle, arbitration_id, data, size); } else if(!handle->isotp_receive_handle.completed) { IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims, &handle->isotp_receive_handle, arbitration_id, data, size); if(message.completed) { if(message.size > 0) { response.mode = message.payload[0]; if(handle_negative_response(&message, &response, shims)) { shims->log("Received a negative response to mode %d on arb ID 0x%x", response.mode, response.arbitration_id); // TODO clarify what it means for a handle to be successful (we made // a good request+response) vs a request itself being // successfully // (the other node didn't return a negative response). handle->success = true; handle->completed = true; } else if(handle_positive_response(handle, &message, &response, shims)) { shims->log("Received a positive mode %d response on arb ID 0x%x", response.mode, response.arbitration_id); handle->success = true; handle->completed = true; } else { shims->log("Response was for a mode 0x%x request, not our mode 0x%x request", response.mode - MODE_RESPONSE_OFFSET, handle->request.mode); } } if(handle->completed && handle->callback != NULL) { handle->callback(&response); } } } else { shims->log("Mode %d request to arb ID 0x%x is already completed", handle->request.mode, handle->request.arbitration_id); } return response; }