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 static uint16_t autoset_pid_length(uint8_t mode, uint16_t pid,
55 if(pid > 0xffff || mode > 10) {
64 DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims,
65 DiagnosticRequest* request, DiagnosticResponseReceived callback) {
66 DiagnosticRequestHandle handle = {
73 uint8_t payload[MAX_DIAGNOSTIC_PAYLOAD_SIZE] = {0};
74 payload[MODE_BYTE_INDEX] = request->mode;
75 if(request->has_pid) {
76 request->pid_length = autoset_pid_length(request->mode,
77 request->pid, request->pid_length);
78 handle.request.pid_length = request->pid_length;
79 set_bitfield(request->pid, PID_BYTE_INDEX * CHAR_BIT,
80 request->pid_length * CHAR_BIT, payload, sizeof(payload));
82 if(request->payload_length > 0) {
83 memcpy(&payload[PID_BYTE_INDEX + request->pid_length],
84 request->payload, request->payload_length);
87 handle.isotp_shims = isotp_init_shims(shims->log,
88 shims->send_can_message,
90 handle.isotp_shims.frame_padding = !request->no_frame_padding;
92 handle.isotp_send_handle = isotp_send(&handle.isotp_shims,
93 request->arbitration_id, payload,
94 1 + request->payload_length + request->pid_length,
96 if(shims->log != NULL) {
97 char request_string[128] = {0};
98 diagnostic_request_to_string(request, request_string, sizeof(request_string));
99 shims->log("Sending diagnostic request: %s", request_string);
102 setup_receive_handle(&handle);
104 // TODO notes on multi frame:
105 // TODO what are the timers for exactly?
107 // when sending multi frame, send 1 frame, wait for a response
108 // if it says send all, send all right away
109 // if it says flow control, set the time for the next send
110 // instead of creating a timer with an async callback, add a process_handle
111 // function that's called repeatedly in the main loop - if it's time to
112 // send, we do it. so there's a process_handle_send and receive_can_frame
113 // that are just called continuously from the main loop. it's a waste of a
114 // few cpu cycles but it may be more natural than callbacks.
116 // what would a timer callback look like...it would need to pass the handle
117 // and that's all. seems like a context void* would be able to capture all
118 // of the information but arg, memory allocation. look at how it's done in
119 // the other library again
124 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
125 DiagnosticPidRequestType pid_request_type, uint16_t arbitration_id,
126 uint16_t pid, DiagnosticResponseReceived callback) {
127 DiagnosticRequest request = {
128 arbitration_id: arbitration_id,
129 mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22,
134 return diagnostic_request(shims, &request, callback);
137 static bool handle_negative_response(IsoTpMessage* message,
138 DiagnosticResponse* response, DiagnosticShims* shims) {
139 bool response_was_negative = false;
140 if(response->mode == NEGATIVE_RESPONSE_MODE) {
141 response_was_negative = true;
142 if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) {
143 response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX];
146 if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
147 response->negative_response_code =
148 message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
151 response->success = false;
152 response->completed = true;
154 return response_was_negative;
157 static bool handle_positive_response(DiagnosticRequestHandle* handle,
158 IsoTpMessage* message, DiagnosticResponse* response,
159 DiagnosticShims* shims) {
160 bool response_was_positive = false;
161 if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
162 response_was_positive = true;
163 // hide the "response" version of the mode from the user
165 response->mode = handle->request.mode;
166 response->has_pid = false;
167 if(handle->request.has_pid && message->size > 1) {
168 response->has_pid = true;
169 if(handle->request.pid_length == 2) {
170 response->pid = get_bitfield(message->payload, message->size,
171 PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
173 response->pid = message->payload[PID_BYTE_INDEX];
178 uint8_t payload_index = 1 + handle->request.pid_length;
179 response->payload_length = MAX(0, message->size - payload_index);
180 if(response->payload_length > 0) {
181 memcpy(response->payload, &message->payload[payload_index],
182 response->payload_length);
185 if((!handle->request.has_pid && !response->has_pid)
186 || response->pid == handle->request.pid) {
187 response->success = true;
188 response->completed = true;
190 response_was_positive = false;
193 return response_was_positive;
196 DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims,
197 DiagnosticRequestHandle* handle, const uint16_t arbitration_id,
198 const uint8_t data[], const uint8_t size) {
200 DiagnosticResponse response = {
201 arbitration_id: arbitration_id,
206 if(!handle->isotp_send_handle.completed) {
207 isotp_continue_send(&handle->isotp_shims,
208 &handle->isotp_send_handle, arbitration_id, data, size);
211 for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
212 IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
213 &handle->isotp_receive_handles[i], arbitration_id, data,
216 if(message.completed) {
217 if(message.size > 0) {
218 response.mode = message.payload[0];
219 if(handle_negative_response(&message, &response, shims)) {
220 if(shims->log != NULL) {
221 char response_string[128] = {0};
222 diagnostic_response_to_string(&response, response_string, sizeof(response_string));
223 shims->log("Received a negative response: %s", response_string);
226 handle->success = true;
227 handle->completed = true;
228 } else if(handle_positive_response(handle, &message,
230 if(shims->log != NULL) {
231 char response_string[128] = {0};
232 diagnostic_response_to_string(&response, response_string, sizeof(response_string));
233 shims->log("Received a positive response: %s", response_string);
236 handle->success = true;
237 handle->completed = true;
239 if(shims->log != NULL) {
240 char response_string[128] = {0};
241 diagnostic_response_to_string(&response, response_string, sizeof(response_string));
242 shims->log("Expected a mode 0x%x response to pid 0x%x but received: %s",
243 MAX(0, response.mode - MODE_RESPONSE_OFFSET),
249 if(shims->log != NULL) {
250 shims->log("Received an empty response on arb ID 0x%x",
251 response.arbitration_id);
255 if(handle->completed && handle->callback != NULL) {
256 handle->callback(&response);
266 int diagnostic_payload_to_integer(const DiagnosticResponse* response) {
267 return get_bitfield(response->payload, response->payload_length, 0,
268 response->payload_length * CHAR_BIT);
271 float diagnostic_decode_obd2_pid(const DiagnosticResponse* response,
272 int parsed_payload) {
273 // handles on the single number values, not the bit encoded ones
274 switch(response->pid) {
276 return response->payload[0] * 3;
278 return (response->payload[0] * 256 + response->payload[1]) / 4.0;
282 return response->payload[0];
284 return (response->payload[0] * 256 + response->payload[1]) / 100.0;
292 return response->payload[0] * 100.0 / 255.0;
297 return response->payload[0] - 40;
299 return response->payload[0] - 125;
305 void diagnostic_response_to_string(const DiagnosticResponse* response,
306 char* destination, size_t destination_length) {
307 int bytes_used = snprintf(destination, destination_length,
308 "arb_id: 0x%02x, mode: 0x%x, pid: 0x%x, ",
309 response->arbitration_id,
312 int remaining_space = destination_length - bytes_used;
313 if(response->payload_length > 0) {
314 snprintf(destination + bytes_used, remaining_space,
315 "payload: 0x%02x%02x%02x%02x%02x%02x%02x",
316 response->payload[0],
317 response->payload[1],
318 response->payload[2],
319 response->payload[3],
320 response->payload[4],
321 response->payload[5],
322 response->payload[6]);
324 snprintf(destination + bytes_used, remaining_space, "no payload");
328 void diagnostic_request_to_string(const DiagnosticRequest* request,
329 char* destination, size_t destination_length) {
330 int bytes_used = snprintf(destination, destination_length,
331 "arb_id: 0x%02x, mode: 0x%x, pid: 0x%x, ",
332 request->arbitration_id,
335 int remaining_space = destination_length - bytes_used;
336 if(request->payload_length > 0) {
337 snprintf(destination + bytes_used, remaining_space,
338 "payload: 0x%02x%02x%02x%02x%02x%02x%02x",
345 request->payload[6]);
347 snprintf(destination + bytes_used, remaining_space, "no payload");