#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
DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims,
DiagnosticRequest* request, DiagnosticResponseReceived callback) {
DiagnosticRequestHandle handle = {
- // TODO can we copy the request?
request: *request,
callback: callback,
success: false,
NULL);
handle.isotp_receive_handle = isotp_receive(&handle.isotp_shims,
- // TODO need to either always add 0x8 or let the user specify
- request->arbitration_id + 0x8,
+ request->arbitration_id + ARBITRATION_ID_OFFSET,
NULL);
- // when a can frame is received and passes to the diagnostic handle
- // if we haven't successfuly sent the entire message yet, give it to the
- // isottp send handle
- // if we have sent it, give it to the isotp rx handle
- // if we've received properly, mark this request as completed
- // how do you get the result? we have it set up for callbacks but that's
- // getting to be kind of awkward
- //
- // say it were to call a callback...what state would it need to pass?
- //
- // the iso-tp message received callback needs to pass the handle and the
- // received message
- //
- // so in the obd2 library, we get a callback with an isotp message. how do
- // we know what diag request i went with, and which diag callback to use? we
- // could store context with the isotp handle. the problem is that context is
- // self referential and on the stack, so we really can't get a pointer to
- // it.
- //
- // the diagnostic response received callback needs to pass the diagnostic
- // handle and the diag response
- //
- // let's say we simplify things and drop the callbacks.
- //
- // isotp_receive_can_frame returns an isotp handle with a complete message
- // in it if one was received
- //
- // diagnostic_receive_can_frame returns a diaghandle if one was received
- //
- // so in the user code you would throw the can frame at each of your active
- // diag handles and see if any return a completed message.
- //
- // is there any advantage to a callback approach? callbacks are useful when
- // you have something that will block, bt we don't have anything that will
- // block. it's async but we return immediately from each partial parsing
- // attempt.
- //
- // argh, but will we need the callbacks when we add timers for isotp multi
- // frame?
- //
- // what are the timers for exactly?
+ // 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
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) {
IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
&handle->isotp_receive_handle, arbitration_id, data, size);
- // TODO this could be cleaned and DRY'd up a bit
if(message.completed) {
if(message.size > 0) {
response.mode = message.payload[0];
- if(response.mode == NEGATIVE_RESPONSE_MODE) {
- if(message.size > NEGATIVE_RESPONSE_MODE_INDEX) {
- // TODO we're setting the mode to the originating
- // request for the error, so the user can confirm - i
- // think this is OK since we're storing the failure
- // status elsewhere, but think about it.
- 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;
+ 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 {
- if(response.mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
- // 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;
- } 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);
- }
+ shims->log("Response was for a mode 0x%x request, not our mode 0x%x request",
+ response.mode - MODE_RESPONSE_OFFSET,
+ handle->request.mode);
}
}
- response.completed = true;
- // TODO clarify what it means for a handle to be successful (we made
- // a good request+response) vs a request itself being successfuly
- // (the other node didn't return a negative response).
- handle->success = true;
- handle->completed = true;
-
- if(handle->callback != NULL) {
+ if(handle->completed && handle->callback != NULL) {
handle->callback(&response);
}
}
} else {
- shims->log("Handle is already completed");
+ shims->log("Mode %d request to arb ID 0x%x is already completed",
+ handle->request.mode, handle->request.arbitration_id);
}
return response;
}
-
-// TODO everything below here is for future work...not critical for now.
-
-DiagnosticRequestHandle diagnostic_request_malfunction_indicator_status(
- DiagnosticShims* shims,
- DiagnosticMilStatusReceived callback) {
- // TODO request malfunction indicator light (MIL) status - request mode 1
- // pid 1, parse first bit
-}
-
-DiagnosticRequestHandle diagnostic_request_vin(DiagnosticShims* shims,
- DiagnosticVinReceived callback) {
-}
-
-DiagnosticRequestHandle diagnostic_request_dtc(DiagnosticShims* shims,
- DiagnosticTroubleCodeType dtc_type,
- DiagnosticTroubleCodesReceived callback) {
-}
-
-bool diagnostic_clear_dtc(DiagnosticShims* shims) {
-}
-
-DiagnosticRequestHandle diagnostic_enumerate_pids(DiagnosticShims* shims,
- DiagnosticRequest* request, DiagnosticPidEnumerationReceived callback) {
- // 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
-}
Code Review / apps / low-level-can-service.git / commitdiff