Clean up the primary diag request handler.
[apps/low-level-can-service.git] / src / obd2 / obd2.c
index 9b4ea92..0590c1b 100644 (file)
 #include <obd2/obd2.h>
+#include <arpa/inet.h>
+
+#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;
 }
 
-// decide mode 0x1 / 0x22 based on pid type
 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
-        DiagnosticPidRequestType pid_request_type, uint16_t pid,
-        DiagnosticResponseReceived callback) {
-}
+        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
+    };
 
-// TODO request malfunction indicator light (MIL) status - request mode 1 pid 1,
-//      parse first bit
-DiagnosticRequestHandle diagnostic_request_malfunction_indicator_status(
-        DiagnosticShims* shims,
-        DiagnosticMilStatusReceived callback) {
+    return diagnostic_request(shims, &request, callback);
 }
 
-DiagnosticRequestHandle diagnostic_request_vin(DiagnosticShims* shims,
-        DiagnosticVinReceived 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];
+        }
 
-DiagnosticRequestHandle diagnostic_request_dtc(DiagnosticShims* shims,
-        DiagnosticTroubleCodeType dtc_type,
-        DiagnosticTroubleCodesReceived callback) {
-}
+        if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
+            response->negative_response_code = message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
+        }
 
-bool diagnostic_clear_dtc(DiagnosticShims* shims) {
+        response->success = false;
+        response->completed = true;
+    }
+    return response_was_negative;
 }
 
-// before calling the callback, split up the received bytes into 1 or 2 byte
-// chunks depending on the mode so the final pid list is actual 1 or 2 byte PIDs
-// TODO request supported PIDs  - request PID 0 and parse 4 bytes in response
-DiagnosticRequestHandle diagnostic_enumerate_pids(DiagnosticShims* shims,
-        DiagnosticRequest* request, DiagnosticPidEnumerationReceived callback) {
+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;
 }
 
-void diagnostic_receive_can_frame(DiagnosticRequestHandle* handler,
-        const uint16_t arbitration_id, const uint8_t data[],
-        const uint8_t size) {
+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;
 }