Rename from simply obd2 to more general UDS (unified diagnostics).

Fixed #1.

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;
+}