Return completed rx messages instead of relying on callbacks.

README.mkd

@@ -58,7 +58,8 @@ Then, set up a callback and send an ISO-TP message:
 Finally, receive an ISO-TP message:
 
     // This is your callback for when a complete ISO-TP message is received at
-    // the arbitration ID you specify
+    // the arbitration ID you specify - it's optional. The completed message is
+    // also returned by isotp_receive_can_frame
     void message_received(const IsoTpMessage* message) {
     }
 
@@ -69,9 +70,9 @@ Finally, receive an ISO-TP message:
     } else {
         while(true) {
             // Continue to read from CAN, passing off each message to the handle
-            bool complete = isotp_receive_can_frame(&shims, &handle, 0x100, data, size);
+            IsoTp message = isotp_receive_can_frame(&shims, &handle, 0x100, data, size);
 
-            if(complete && handle.completed) {
+            if(message.completed && handle.completed) {
                 if(handle.success) {
                     // A message has been received successfully
                 } else {

src/isotp/isotp.c

@@ -33,26 +33,29 @@ void isotp_message_to_string(const IsoTpMessage* message, char* destination,
             message->arbitration_id, payload_string);
 }
 
-bool isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
+IsoTpMessage isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
         const uint16_t arbitration_id, const uint8_t data[],
         const uint8_t data_length) {
-    bool message_completed = false;
+    IsoTpMessage message = {
+        arbitration_id: arbitration_id,
+        completed: false
+    };
 
     if(data_length < 1) {
-        return message_completed;
+        return message;
     }
 
     if(handle->type == ISOTP_HANDLE_RECEIVING) {
         if(handle->receive_handle.arbitration_id != arbitration_id) {
-            return message_completed;
+            return message;
         }
     } else if(handle->type == ISOTP_HANDLE_SENDING) {
         if(handle->send_handle.receiving_arbitration_id != arbitration_id) {
-            return message_completed;
+            return message;
         }
     } else {
         shims->log("The ISO-TP handle is corrupt");
-        return message_completed;
+        return message;
     }
 
     IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
@@ -70,18 +73,15 @@ bool isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
 
     switch(pci) {
         case PCI_SINGLE: {
-            IsoTpMessage message = {
-                arbitration_id: arbitration_id,
-                payload: payload,
-                size: payload_length
-            };
-
-            message_completed = isotp_handle_single_frame(handle, &message);
+            message.payload = payload;
+            message.size = payload_length;
+            message.completed = true;
+            isotp_handle_single_frame(handle, &message);
             break;
          }
         default:
             shims->log("Only single frame messages are supported");
             break;
     }
-    return message_completed;
+    return message;
 }

src/isotp/isotp.h

@@ -18,8 +18,9 @@ const bool ISO_TP_DEFAULT_FRAME_PADDING_STATUS;
 
 typedef struct {
     const uint16_t arbitration_id;
-    const uint8_t* payload;
-    const uint16_t size;
+    uint8_t* payload;
+    uint16_t size;
+    bool completed;
 } IsoTpMessage;
 
 typedef void (*LogShim)(const char* message, ...);
@@ -95,11 +96,8 @@ IsoTpShims isotp_init_shims(LogShim log,
 
 /* Public:
  *
- * Returns true if a complete ISO-TP message was sent or received as of
- * processing this CAN frame. Check the 'success' and 'completed' flag on the
- * handle to make sure.
  */
-bool isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
+IsoTpMessage isotp_receive_can_frame(IsoTpShims* shims, IsoTpHandle* handle,
         const uint16_t arbitration_id, const uint8_t data[],
         const uint8_t size);
 
@@ -121,8 +119,8 @@ IsoTpHandle isotp_send(IsoTpShims* shims, const uint16_t arbitration_id,
         const uint8_t* payload, uint16_t size,
         IsoTpMessageSentHandler callback);
 
-IsoTpHandle isotp_receive(IsoTpShims* shims, const uint16_t arbitration_id,
-        IsoTpMessageReceivedHandler callback);
+IsoTpHandle isotp_receive(IsoTpShims* shims,
+        const uint16_t arbitration_id, IsoTpMessageReceivedHandler callback);
 
 #ifdef __cplusplus
 }

src/isotp/receive.c

@@ -24,4 +24,3 @@ IsoTpHandle isotp_receive(IsoTpShims* shims,
     };
     return handle;
 }
-

src/isotp/send.c

@@ -49,6 +49,8 @@ IsoTpHandle isotp_send_multi_frame(IsoTpShims* shims, IsoTpMessage* message,
         completed: true,
         type: ISOTP_HANDLE_SENDING
     };
+    // TODO need to set sending and receiving arbitration IDs separately if we
+    // can't always just add 0x8 (and I think we can't)
     return handle;
 }
 

src/isotp/send.h

@@ -9,9 +9,6 @@
 extern "C" {
 #endif
 
-IsoTpHandle isotp_send(IsoTpShims* shims, const uint16_t arbitration_id,
-        const uint8_t* payload, uint16_t size,
-        IsoTpMessageSentHandler callback);
 
 #ifdef __cplusplus
 }

tests/test_receive.c

@@ -28,7 +28,8 @@ extern void setup();
 START_TEST (test_receive_wrong_id)
 {
     const uint8_t data[CAN_MESSAGE_BYTE_SIZE] = {0};
-    fail_if(isotp_receive_can_frame(&SHIMS, &HANDLE, 0x100, data, 1));
+    IsoTpMessage message = isotp_receive_can_frame(&SHIMS, &HANDLE, 0x100, data, 1);
+    fail_if(message.completed);
     fail_if(message_was_received);
 }
 END_TEST
@@ -37,7 +38,8 @@ START_TEST (test_receive_bad_pci)
 {
     // 4 is a reserved number for the PCI field - only 0-3 are allowed
     const uint8_t data[CAN_MESSAGE_BYTE_SIZE] = {0x40};
-    fail_if(isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 1));
+    IsoTpMessage message = isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 1);
+    fail_if(message.completed);
     fail_if(message_was_received);
 }
 END_TEST
@@ -45,7 +47,8 @@ END_TEST
 START_TEST (test_receive_single_frame_empty_payload)
 {
     const uint8_t data[CAN_MESSAGE_BYTE_SIZE] = {0x00, 0x12, 0x34};
-    fail_unless(isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 3));
+    IsoTpMessage message = isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 3);
+    fail_unless(message.completed);
     fail_unless(message_was_received);
     ck_assert_int_eq(last_message_received_arb_id, 0x2a);
     ck_assert_int_eq(last_message_received_payload_size, 0);
@@ -55,7 +58,8 @@ END_TEST
 START_TEST (test_receive_single_frame)
 {
     const uint8_t data[CAN_MESSAGE_BYTE_SIZE] = {0x02, 0x12, 0x34};
-    fail_unless(isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 3));
+    IsoTpMessage message = isotp_receive_can_frame(&SHIMS, &HANDLE, 0x2a, data, 3);
+    fail_unless(message.completed);
     fail_unless(message_was_received);
     ck_assert_int_eq(last_message_received_arb_id, 0x2a);
     ck_assert_int_eq(last_message_received_payload_size, 2);