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-rw-r--r--src/uds/uds.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/src/uds/uds.c b/src/uds/uds.c
new file mode 100644
index 00000000..443b05a0
--- /dev/null
+++ b/src/uds/uds.c
@@ -0,0 +1,243 @@
+#include <uds/uds.h>
+#include <bitfield/bitfield.h>
+#include <string.h>
+#include <limits.h>
+#include <stddef.h>
+#include <sys/param.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
+
+#ifndef MAX
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#endif
+
+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;
+}
+
+static void setup_receive_handle(DiagnosticRequestHandle* handle) {
+ if(handle->request.arbitration_id == OBD2_FUNCTIONAL_BROADCAST_ID) {
+ uint16_t response_id;
+ for(response_id = 0;
+ response_id < OBD2_FUNCTIONAL_RESPONSE_COUNT; ++response_id) {
+ handle->isotp_receive_handles[response_id] = isotp_receive(
+ &handle->isotp_shims, OBD2_FUNCTIONAL_RESPONSE_START + response_id,
+ NULL);
+ }
+ handle->isotp_receive_handle_count = OBD2_FUNCTIONAL_RESPONSE_COUNT;
+ } else {
+ handle->isotp_receive_handle_count = 1;
+ handle->isotp_receive_handles[0] = isotp_receive(&handle->isotp_shims,
+ handle->request.arbitration_id + ARBITRATION_ID_OFFSET,
+ NULL);
+ }
+}
+
+
+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] = {0};
+ payload[MODE_BYTE_INDEX] = request->mode;
+ if(request->pid_length > 0) {
+ set_bitfield(request->pid, PID_BYTE_INDEX * CHAR_BIT,
+ request->pid_length * CHAR_BIT, 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);
+ if(shims->log != NULL) {
+ 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",
+ request->arbitration_id,
+ request->mode,
+ request->pid,
+ request->payload[0],
+ request->payload[1],
+ request->payload[2],
+ request->payload[3],
+ request->payload[4],
+ request->payload[5],
+ request->payload[6],
+ request->payload_length);
+ }
+
+ setup_receive_handle(&handle);
+
+ // 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;
+}
+
+DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
+ 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
+ };
+
+ 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;
+ response->has_pid = false;
+ if(handle->request.pid_length > 0 && message->size > 1) {
+ response->has_pid = true;
+ if(handle->request.pid_length == 2) {
+ response->pid = get_bitfield(message->payload, message->size,
+ PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
+ } else {
+ response->pid = message->payload[PID_BYTE_INDEX];
+ }
+
+ }
+
+ uint8_t payload_index = 1 + handle->request.pid_length;
+ response->payload_length = MAX(0, message->size - payload_index);
+ if(response->payload_length > 0) {
+ memcpy(response->payload, &message->payload[payload_index],
+ response->payload_length);
+ }
+
+ if((handle->request.pid_length == 0 && !response->has_pid)
+ || response->pid == handle->request.pid) {
+ response->success = true;
+ response->completed = true;
+ } else {
+ response_was_positive = false;
+ }
+ }
+ 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) {
+
+ 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 {
+ uint8_t i;
+ for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
+ IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
+ &handle->isotp_receive_handles[i], arbitration_id, data, size);
+
+ // TODO as of now we're completing the handle as soon as one
+ // broadcast response is received....need to hang on for 100ms
+ 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);
+ 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 (pid 0x%x), not our mode 0x%x request (pid 0x%x)",
+ MAX(0, response.mode - MODE_RESPONSE_OFFSET),
+ response.pid, handle->request.mode,
+ handle->request.pid);
+ // TODO just leave handles open until the user decides
+ // to be done with it - keep a count of valid responses
+ // received.
+ }
+ } else {
+ shims->log("Received an empty response on arb ID 0x%x",
+ response.arbitration_id);
+ }
+
+ if(handle->completed && handle->callback != NULL) {
+ handle->callback(&response);
+ }
+ }
+ }
+ }
+ return response;
+}