CAN-binder/libs/uds-c/src/uds/uds.c

   1 #include <uds/uds.h>
   2 #include <bitfield/bitfield.h>
   3 #include <canutil/read.h>
   4 #include <string.h>
   5 #include <limits.h>
   6 #include <stddef.h>
   7 #include <sys/param.h>
   8 #include <inttypes.h>
   9
  10 #define ARBITRATION_ID_OFFSET 0x8
  11 #define MODE_RESPONSE_OFFSET 0x40
  12 #define NEGATIVE_RESPONSE_MODE 0x7f
  13 #define MAX_DIAGNOSTIC_PAYLOAD_SIZE 6
  14 #define MODE_BYTE_INDEX 0
  15 #define PID_BYTE_INDEX 1
  16 #define NEGATIVE_RESPONSE_MODE_INDEX 1
  17 #define NEGATIVE_RESPONSE_NRC_INDEX 2
  18
  19 #ifndef MAX
  20 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
  21 #endif
  22
  23 DiagnosticShims diagnostic_init_shims(LogShim log,
  24         SendCanMessageShim send_can_message,
  25         SetTimerShim set_timer) {
  26     DiagnosticShims shims = {
  27         log: log,
  28         send_can_message: send_can_message,
  29         set_timer: set_timer
  30     };
  31     return shims;
  32 }
  33
  34 static void setup_receive_handle(DiagnosticRequestHandle* handle) {
  35     if(handle->request.arbitration_id == OBD2_FUNCTIONAL_BROADCAST_ID) {
  36         uint32_t response_id;
  37         for(response_id = 0;
  38                 response_id < OBD2_FUNCTIONAL_RESPONSE_COUNT; ++response_id) {
  39             handle->isotp_receive_handles[response_id] = isotp_receive(
  40                     &handle->isotp_shims,
  41                     OBD2_FUNCTIONAL_RESPONSE_START + response_id,
  42                     NULL);
  43         }
  44         handle->isotp_receive_handle_count = OBD2_FUNCTIONAL_RESPONSE_COUNT;
  45     } else {
  46         handle->isotp_receive_handle_count = 1;
  47         handle->isotp_receive_handles[0] = isotp_receive(&handle->isotp_shims,
  48                 handle->request.arbitration_id + ARBITRATION_ID_OFFSET,
  49                 NULL);
  50     }
  51 }
  52
  53 static uint16_t autoset_pid_length(uint8_t mode, uint16_t pid,
  54         uint8_t pid_length) {
  55     if(pid_length == 0) {
  56         if(mode <= 0xa || mode == 0x3e ) {
  57             pid_length = 1;
  58         } else if(pid > 0xffff || ((pid & 0xFF00) > 0x0)) {
  59             pid_length = 2;
  60         } else {
  61             pid_length = 1;
  62         }
  63     }
  64     return pid_length;
  65 }
  66
  67 static void send_diagnostic_request(DiagnosticShims* shims,
  68         DiagnosticRequestHandle* handle) {
  69     uint8_t payload[MAX_DIAGNOSTIC_PAYLOAD_SIZE] = {0};
  70     payload[MODE_BYTE_INDEX] = handle->request.mode;
  71     if(handle->request.has_pid) {
  72         handle->request.pid_length = autoset_pid_length(handle->request.mode,
  73                 handle->request.pid, handle->request.pid_length);
  74         set_bitfield(handle->request.pid, PID_BYTE_INDEX * CHAR_BIT,
  75                 handle->request.pid_length * CHAR_BIT, payload,
  76                 sizeof(payload));
  77     }
  78
  79     if(handle->request.payload_length > 0) {
  80         memcpy(&payload[PID_BYTE_INDEX + handle->request.pid_length],
  81                 handle->request.payload, handle->request.payload_length);
  82     }
  83
  84     handle->isotp_send_handle = isotp_send(&handle->isotp_shims,
  85             handle->request.arbitration_id, payload,
  86             1 + handle->request.payload_length + handle->request.pid_length,
  87             NULL);
  88     if(handle->isotp_send_handle.completed &&
  89             !handle->isotp_send_handle.success) {
  90         handle->completed = true;
  91         handle->success = false;
  92         if(shims->log != NULL) {
  93             shims->log("%s", "Diagnostic request not sent");
  94         }
  95     } else if(shims->log != NULL) {
  96         char request_string[128] = {0};
  97         diagnostic_request_to_string(&handle->request, request_string,
  98                 sizeof(request_string));
  99         shims->log("Sending diagnostic request: %s", request_string);
 100     }
 101 }
 102
 103 bool diagnostic_request_sent(DiagnosticRequestHandle* handle) {
 104     return handle->isotp_send_handle.completed;
 105 }
 106
 107 void start_diagnostic_request(DiagnosticShims* shims,
 108         DiagnosticRequestHandle* handle) {
 109     handle->success = false;
 110     handle->completed = false;
 111     send_diagnostic_request(shims, handle);
 112     if(!handle->completed) {
 113         setup_receive_handle(handle);
 114     }
 115 }
 116
 117 DiagnosticRequestHandle generate_diagnostic_request(DiagnosticShims* shims,
 118         DiagnosticRequest* request, DiagnosticResponseReceived callback) {
 119     DiagnosticRequestHandle handle = {
 120         request: *request,
 121         callback: callback,
 122         success: false,
 123         completed: false
 124     };
 125
 126     handle.isotp_shims = isotp_init_shims(shims->log,
 127             shims->send_can_message,
 128             shims->set_timer);
 129     handle.isotp_shims.frame_padding = !request->no_frame_padding;
 130
 131     return handle;
 132     // TODO notes on multi frame:
 133     // TODO what are the timers for exactly?
 134     //
 135     // when sending multi frame, send 1 frame, wait for a response
 136     // if it says send all, send all right away
 137     // if it says flow control, set the time for the next send
 138     // instead of creating a timer with an async callback, add a process_handle
 139     // function that's called repeatedly in the main loop - if it's time to
 140     // send, we do it. so there's a process_handle_send and receive_can_frame
 141     // that are just called continuously from the main loop. it's a waste of a
 142     // few cpu cycles but it may be more  natural than callbacks.
 143     //
 144     // what would a timer callback look like...it would need to pass the handle
 145     // and that's all. seems like a context void* would be able to capture all
 146     // of the information but arg, memory allocation. look at how it's done in
 147     // the other library again
 148     //
 149 }
 150
 151 DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims,
 152         DiagnosticRequest* request, DiagnosticResponseReceived callback) {
 153     DiagnosticRequestHandle handle = generate_diagnostic_request(
 154             shims, request, callback);
 155     start_diagnostic_request(shims, &handle);
 156     return handle;
 157 }
 158
 159 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
 160         DiagnosticPidRequestType pid_request_type, uint32_t arbitration_id,
 161         uint16_t pid, DiagnosticResponseReceived callback) {
 162     DiagnosticRequest request = {
 163         arbitration_id: arbitration_id,
 164         mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22,
 165         has_pid: true,
 166         pid: pid
 167     };
 168
 169     return diagnostic_request(shims, &request, callback);
 170 }
 171
 172 static bool handle_negative_response(IsoTpMessage* message,
 173         DiagnosticResponse* response, DiagnosticShims* shims) {
 174     bool response_was_negative = false;
 175     if(response->mode == NEGATIVE_RESPONSE_MODE) {
 176         response_was_negative = true;
 177         if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) {
 178             response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX];
 179         }
 180
 181         if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
 182             response->negative_response_code =
 183                     message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
 184         }
 185
 186         response->success = false;
 187         response->completed = true;
 188     }
 189     return response_was_negative;
 190 }
 191
 192 static bool handle_positive_response(DiagnosticRequestHandle* handle,
 193         IsoTpMessage* message, DiagnosticResponse* response,
 194         DiagnosticShims* shims) {
 195     bool response_was_positive = false;
 196     if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
 197         response_was_positive = true;
 198         // hide the "response" version of the mode from the user
 199         // if it matched
 200         response->mode = handle->request.mode;
 201         response->has_pid = false;
 202         if(handle->request.has_pid && message->size > 1) {
 203             response->has_pid = true;
 204             if(handle->request.pid_length == 2) {
 205                 response->pid = get_bitfield(message->payload, message->size,
 206                         PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
 207             } else {
 208                 response->pid = message->payload[PID_BYTE_INDEX];
 209             }
 210
 211         }
 212
 213         if((!handle->request.has_pid && !response->has_pid)
 214                 || response->pid == handle->request.pid) {
 215             response->success = true;
 216             response->completed = true;
 217
 218             uint8_t payload_index = 1 + handle->request.pid_length;
 219             response->payload_length = MAX(0, message->size - payload_index);
 220             if(response->payload_length > 0) {
 221                 memcpy(response->payload, &message->payload[payload_index],
 222                         response->payload_length);
 223             }
 224         } else {
 225             response_was_positive = false;
 226         }
 227     }
 228     return response_was_positive;
 229 }
 230
 231 DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims,
 232         DiagnosticRequestHandle* handle, const uint32_t arbitration_id,
 233         const uint8_t data[], const uint8_t size) {
 234
 235     DiagnosticResponse response = {
 236         arbitration_id: arbitration_id,
 237         multi_frame: false,
 238         success: false,
 239         completed: false
 240     };
 241
 242     if(!handle->isotp_send_handle.completed) {
 243         isotp_continue_send(&handle->isotp_shims,
 244                 &handle->isotp_send_handle, arbitration_id, data, size);
 245     } else {
 246         uint8_t i;
 247         for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
 248             IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
 249                     &handle->isotp_receive_handles[i], arbitration_id, data,
 250                     size);
 251             response.multi_frame = message.multi_frame;
 252
 253             if(message.completed) {
 254                 if(message.size > 0) {
 255                     response.mode = message.payload[0];
 256                     if(handle_negative_response(&message, &response, shims) ||
 257                             handle_positive_response(handle, &message,
 258                                 &response, shims)) {
 259                         if(shims->log != NULL) {
 260                             char response_string[128] = {0};
 261                             diagnostic_response_to_string(&response,
 262                                     response_string, sizeof(response_string));
 263                             shims->log("Diagnostic response received: %s",
 264                                     response_string);
 265                         }
 266
 267                         handle->success = true;
 268                         handle->completed = true;
 269                     }
 270                 } else {
 271                     if(shims->log != NULL) {
 272                         shims->log("Received an empty response on arb ID 0x%x",
 273                                 response.arbitration_id);
 274                     }
 275                 }
 276
 277                 if(handle->completed && handle->callback != NULL) {
 278                     handle->callback(&response);
 279                 }
 280
 281                 break;
 282             }
 283         }
 284     }
 285     return response;
 286 }
 287
 288 int diagnostic_payload_to_integer(const DiagnosticResponse* response) {
 289     return get_bitfield(response->payload, response->payload_length, 0,
 290             response->payload_length * CHAR_BIT);
 291 }
 292
 293 float diagnostic_decode_obd2_pid(const DiagnosticResponse* response) {
 294     // handles on the single number values, not the bit encoded ones
 295     switch(response->pid) {
 296         case 0xa:
 297             return response->payload[0] * 3;
 298         case 0xc:
 299             return (response->payload[0] * 256 + response->payload[1]) / 4.0;
 300         case 0xd:
 301         case 0x33:
 302         case 0xb:
 303             return response->payload[0];
 304         case 0x10:
 305             return (response->payload[0] * 256 + response->payload[1]) / 100.0;
 306         case 0x11:
 307         case 0x2f:
 308         case 0x45:
 309         case 0x4c:
 310         case 0x52:
 311         case 0x5a:
 312         case 0x4:
 313             return response->payload[0] * 100.0 / 255.0;
 314         case 0x46:
 315         case 0x5c:
 316         case 0xf:
 317         case 0x5:
 318             return response->payload[0] - 40;
 319         case 0x62:
 320             return response->payload[0] - 125;
 321         default:
 322             return diagnostic_payload_to_integer(response);
 323     }
 324 }
 325
 326 void diagnostic_response_to_string(const DiagnosticResponse* response,
 327         char* destination, size_t destination_length) {
 328     int bytes_used = snprintf(destination, destination_length,
 329             "arb_id: 0x%lx, mode: 0x%x, ",
 330             (unsigned long) response->arbitration_id,
 331             response->mode);
 332
 333     if(response->has_pid) {
 334         bytes_used += snprintf(destination + bytes_used,
 335                 destination_length - bytes_used,
 336                 "pid: 0x%x, ",
 337                 response->pid);
 338     }
 339
 340     if(!response->success) {
 341         bytes_used += snprintf(destination + bytes_used,
 342                 destination_length - bytes_used,
 343                 "nrc: 0x%x, ",
 344                 response->negative_response_code);
 345     }
 346
 347     if(response->payload_length > 0) {
 348         snprintf(destination + bytes_used, destination_length - bytes_used,
 349                 "payload: 0x%02x%02x%02x%02x%02x%02x%02x",
 350                 response->payload[0],
 351                 response->payload[1],
 352                 response->payload[2],
 353                 response->payload[3],
 354                 response->payload[4],
 355                 response->payload[5],
 356                 response->payload[6]);
 357     } else {
 358         snprintf(destination + bytes_used, destination_length - bytes_used,
 359                 "no payload");
 360     }
 361 }
 362
 363 void diagnostic_request_to_string(const DiagnosticRequest* request,
 364         char* destination, size_t destination_length) {
 365     int bytes_used = snprintf(destination, destination_length,
 366             "arb_id: 0x%lx, mode: 0x%x, ",
 367             (unsigned long) request->arbitration_id,
 368             request->mode);
 369
 370     if(request->has_pid) {
 371         bytes_used += snprintf(destination + bytes_used,
 372                 destination_length - bytes_used,
 373                 "pid: 0x%x, ",
 374                 request->pid);
 375     }
 376
 377     int remaining_space = destination_length - bytes_used;
 378     if(request->payload_length > 0) {
 379         snprintf(destination + bytes_used, remaining_space,
 380                 "payload: 0x%02x%02x%02x%02x%02x%02x%02x",
 381                 request->payload[0],
 382                 request->payload[1],
 383                 request->payload[2],
 384                 request->payload[3],
 385                 request->payload[4],
 386                 request->payload[5],
 387                 request->payload[6]);
 388     } else {
 389         snprintf(destination + bytes_used, remaining_space, "no payload");
 390     }
 391 }
 392
 393 bool diagnostic_request_equals(const DiagnosticRequest* ours,
 394         const DiagnosticRequest* theirs) {
 395     bool equals = ours->arbitration_id == theirs->arbitration_id &&
 396         ours->mode == theirs->mode;
 397     equals &= ours->has_pid == theirs->has_pid;
 398     equals &= ours->pid == theirs->pid;
 399     return equals;
 400 }