2 #include <bitfield/bitfield.h>
3 #include <canutil/read.h>
9 #define ARBITRATION_ID_OFFSET 0x8
10 #define MODE_RESPONSE_OFFSET 0x40
11 #define NEGATIVE_RESPONSE_MODE 0x7f
12 #define MAX_DIAGNOSTIC_PAYLOAD_SIZE 6
13 #define MODE_BYTE_INDEX 0
14 #define PID_BYTE_INDEX 1
15 #define NEGATIVE_RESPONSE_MODE_INDEX 1
16 #define NEGATIVE_RESPONSE_NRC_INDEX 2
19 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
22 DiagnosticShims diagnostic_init_shims(LogShim log,
23 SendCanMessageShim send_can_message,
24 SetTimerShim set_timer) {
25 DiagnosticShims shims = {
27 send_can_message: send_can_message,
33 static void setup_receive_handle(DiagnosticRequestHandle* handle) {
34 if(handle->request.arbitration_id == OBD2_FUNCTIONAL_BROADCAST_ID) {
37 response_id < OBD2_FUNCTIONAL_RESPONSE_COUNT; ++response_id) {
38 handle->isotp_receive_handles[response_id] = isotp_receive(
40 OBD2_FUNCTIONAL_RESPONSE_START + response_id,
43 handle->isotp_receive_handle_count = OBD2_FUNCTIONAL_RESPONSE_COUNT;
45 handle->isotp_receive_handle_count = 1;
46 handle->isotp_receive_handles[0] = isotp_receive(&handle->isotp_shims,
47 handle->request.arbitration_id + ARBITRATION_ID_OFFSET,
52 DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims,
53 DiagnosticRequest* request, DiagnosticResponseReceived callback) {
54 DiagnosticRequestHandle handle = {
61 uint8_t payload[MAX_DIAGNOSTIC_PAYLOAD_SIZE] = {0};
62 payload[MODE_BYTE_INDEX] = request->mode;
63 if(request->pid_length > 0) {
64 set_bitfield(request->pid, PID_BYTE_INDEX * CHAR_BIT,
65 request->pid_length * CHAR_BIT, payload, sizeof(payload));
67 if(request->payload_length > 0) {
68 memcpy(&payload[PID_BYTE_INDEX + request->pid_length],
69 request->payload, request->payload_length);
72 handle.isotp_shims = isotp_init_shims(shims->log,
73 shims->send_can_message,
76 handle.isotp_send_handle = isotp_send(&handle.isotp_shims,
77 request->arbitration_id, payload,
78 1 + request->payload_length + request->pid_length,
80 if(shims->log != NULL) {
81 shims->log("Sending diagnostic request: arb_id: 0x%02x, mode: 0x%x, pid: 0x%x, payload: 0x%02x%02x%02x%02x%02x%02x%02x, size: %d\r\n",
82 request->arbitration_id,
92 request->payload_length);
95 setup_receive_handle(&handle);
97 // TODO notes on multi frame:
98 // TODO what are the timers for exactly?
100 // when sending multi frame, send 1 frame, wait for a response
101 // if it says send all, send all right away
102 // if it says flow control, set the time for the next send
103 // instead of creating a timer with an async callback, add a process_handle
104 // function that's called repeatedly in the main loop - if it's time to
105 // send, we do it. so there's a process_handle_send and receive_can_frame
106 // that are just called continuously from the main loop. it's a waste of a
107 // few cpu cycles but it may be more natural than callbacks.
109 // what woudl a timer callback look like...it would need to pass the handle
110 // and that's all. seems like a context void* would be able to capture all
111 // of the information but arg, memory allocation. look at how it's done in
112 // the other library again
117 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
118 DiagnosticPidRequestType pid_request_type, uint16_t arbitration_id,
119 uint16_t pid, DiagnosticResponseReceived callback) {
120 DiagnosticRequest request = {
121 arbitration_id: arbitration_id,
122 mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22,
124 pid_length: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 1 : 2
127 return diagnostic_request(shims, &request, callback);
130 static bool handle_negative_response(IsoTpMessage* message,
131 DiagnosticResponse* response, DiagnosticShims* shims) {
132 bool response_was_negative = false;
133 if(response->mode == NEGATIVE_RESPONSE_MODE) {
134 response_was_negative = true;
135 if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) {
136 response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX];
139 if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
140 response->negative_response_code =
141 message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
144 response->success = false;
145 response->completed = true;
147 return response_was_negative;
150 static bool handle_positive_response(DiagnosticRequestHandle* handle,
151 IsoTpMessage* message, DiagnosticResponse* response,
152 DiagnosticShims* shims) {
153 bool response_was_positive = false;
154 if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
155 response_was_positive = true;
156 // hide the "response" version of the mode from the user
158 response->mode = handle->request.mode;
159 response->has_pid = false;
160 if(handle->request.pid_length > 0 && message->size > 1) {
161 response->has_pid = true;
162 if(handle->request.pid_length == 2) {
163 response->pid = get_bitfield(message->payload, message->size,
164 PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
166 response->pid = message->payload[PID_BYTE_INDEX];
171 uint8_t payload_index = 1 + handle->request.pid_length;
172 response->payload_length = MAX(0, message->size - payload_index);
173 if(response->payload_length > 0) {
174 memcpy(response->payload, &message->payload[payload_index],
175 response->payload_length);
178 if((handle->request.pid_length == 0 && !response->has_pid)
179 || response->pid == handle->request.pid) {
180 response->success = true;
181 response->completed = true;
183 response_was_positive = false;
186 return response_was_positive;
189 DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims,
190 DiagnosticRequestHandle* handle, const uint16_t arbitration_id,
191 const uint8_t data[], const uint8_t size) {
193 DiagnosticResponse response = {
194 arbitration_id: arbitration_id,
199 if(!handle->isotp_send_handle.completed) {
200 isotp_continue_send(&handle->isotp_shims,
201 &handle->isotp_send_handle, arbitration_id, data, size);
204 for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
205 IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
206 &handle->isotp_receive_handles[i], arbitration_id, data,
209 if(message.completed) {
210 if(message.size > 0) {
211 response.mode = message.payload[0];
212 if(handle_negative_response(&message, &response, shims)) {
213 shims->log("Received a negative response to mode %d on arb ID 0x%x",
214 response.mode, response.arbitration_id);
215 handle->success = true;
216 handle->completed = true;
217 } else if(handle_positive_response(handle, &message,
219 shims->log("Received a positive mode %d response on arb ID 0x%x",
220 response.mode, response.arbitration_id);
221 handle->success = true;
222 handle->completed = true;
224 shims->log("Response was for a mode 0x%x request (pid 0x%x), not our mode 0x%x request (pid 0x%x)",
225 MAX(0, response.mode - MODE_RESPONSE_OFFSET),
226 response.pid, handle->request.mode,
227 handle->request.pid);
230 shims->log("Received an empty response on arb ID 0x%x",
231 response.arbitration_id);
234 if(handle->completed && handle->callback != NULL) {
235 handle->callback(&response);
245 float diagnostic_payload_to_float(const DiagnosticResponse* response) {
246 return bitfield_parse_float(response->payload,
247 response->payload_length, 0,
248 response->payload_length * CHAR_BIT, 1.0, 0);