Add an option to control CAN frame padding (on by default).

Fixed #1.

src/isotp/isotp.c

@@ -10,7 +10,8 @@ IsoTpShims isotp_init_shims(LogShim log, SendCanMessageShim send_can_message,
     IsoTpShims shims = {
         log: log,
         send_can_message: send_can_message,
-        set_timer: set_timer
+        set_timer: set_timer,
+        frame_padding: ISO_TP_DEFAULT_FRAME_PADDING_STATUS
     };
     return shims;
 }

src/isotp/isotp_types.h

@@ -96,11 +96,20 @@ typedef void (*IsoTpCanFrameSentHandler)(const IsoTpMessage* message);
  * with the wider system.
  *
  * Use the isotp_init_shims(...) function to create an instance of this struct.
+ *
+ * By default, all CAN frames sent from this device in the process of an ISO-TP
+ * message are padded out to a complete 8 byte frame. This is often required by
+ * ECUs. To disable this feature, change the 'frame_padding' field to false on
+ * the IsoTpShims object returned from isotp_init_shims(...).
+ *
+ * frame_padding - true if outgoing CAN frames should be padded to a full 8
+ *      bytes.
  */
 typedef struct {
     LogShim log;
     SendCanMessageShim send_can_message;
     SetTimerShim set_timer;
+    bool frame_padding;
 } IsoTpShims;
 
 /* Private: PCI types, for identifying each frame of an ISO-TP message.

src/isotp/receive.h

@@ -29,8 +29,6 @@ typedef struct {
     IsoTpMessageReceivedHandler message_received_callback;
     uint16_t timeout_ms;
     // timeout_ms: ISO_TP_DEFAULT_RESPONSE_TIMEOUT,
-    bool frame_padding;
-    // frame_padding: ISO_TP_DEFAULT_FRAME_PADDING_STATUS,
     uint8_t* receive_buffer;
     uint16_t received_buffer_size;
     uint16_t incoming_message_size;

src/isotp/send.c

@@ -37,7 +37,7 @@ IsoTpSendHandle isotp_send_single_frame(IsoTpShims* shims, IsoTpMessage* message
     }
 
     shims->send_can_message(message->arbitration_id, can_data,
-            1 + message->size);
+            shims->frame_padding ? 8 : 1 + message->size);
     handle.success = true;
     isotp_complete_send(shims, message, true, callback);
     return handle;

tests/test_core.c

@@ -0,0 +1,78 @@
+#include <isotp/receive.h>
+#include <check.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+extern IsoTpShims SHIMS;
+
+extern void message_sent(const IsoTpMessage* message, const bool success);
+
+extern uint16_t last_can_frame_sent_arb_id;
+extern uint8_t last_can_payload_sent[8];
+extern uint8_t last_can_payload_size;
+extern bool can_frame_was_sent;
+
+extern bool message_was_received;
+extern uint16_t last_message_received_arb_id;
+extern uint8_t last_message_received_payload[];
+extern uint8_t last_message_received_payload_size;
+
+extern uint16_t last_message_sent_arb_id;
+extern bool last_message_sent_status;
+extern uint8_t last_message_sent_payload[];
+extern uint8_t last_message_sent_payload_size;
+
+extern void setup();
+
+START_TEST (test_default_frame_padding_on)
+{
+    ck_assert(SHIMS.frame_padding);
+    const uint8_t payload[] = {0x12, 0x34};
+    uint16_t arbitration_id = 0x2a;
+    isotp_send(&SHIMS, arbitration_id, payload, sizeof(payload), message_sent);
+    ck_assert_int_eq(last_message_sent_arb_id, arbitration_id);
+    fail_unless(last_message_sent_status);
+    ck_assert_int_eq(last_message_sent_payload_size, 2);
+    ck_assert_int_eq(last_can_payload_size, 8);
+
+}
+END_TEST
+
+START_TEST (test_disabled_frame_padding)
+{
+    SHIMS.frame_padding = false;
+    const uint8_t payload[] = {0x12, 0x34};
+    uint16_t arbitration_id = 0x2a;
+    isotp_send(&SHIMS, arbitration_id, payload, sizeof(payload), message_sent);
+    ck_assert_int_eq(last_message_sent_arb_id, arbitration_id);
+    fail_unless(last_message_sent_status);
+    ck_assert_int_eq(last_message_sent_payload_size, 2);
+    ck_assert_int_eq(last_can_payload_size, 3);
+
+}
+END_TEST
+
+Suite* testSuite(void) {
+    Suite* s = suite_create("iso15765");
+    TCase *tc_core = tcase_create("core");
+    tcase_add_checked_fixture(tc_core, setup, NULL);
+    tcase_add_test(tc_core, test_default_frame_padding_on);
+    tcase_add_test(tc_core, test_disabled_frame_padding);
+    suite_add_tcase(s, tc_core);
+
+    return s;
+}
+
+int main(void) {
+    int numberFailed;
+    Suite* s = testSuite();
+    SRunner *sr = srunner_create(s);
+    // Don't fork so we can actually use gdb
+    srunner_set_fork_status(sr, CK_NOFORK);
+    srunner_run_all(sr, CK_NORMAL);
+    numberFailed = srunner_ntests_failed(sr);
+    srunner_free(sr);
+    return (numberFailed == 0) ? 0 : 1;
+}

tests/test_send.c

@@ -28,6 +28,7 @@ extern void setup();
 
 START_TEST (test_send_empty_payload)
 {
+    SHIMS.frame_padding = false;
     uint16_t arbitration_id = 0x2a;
     IsoTpSendHandle handle = isotp_send(&SHIMS, arbitration_id, NULL, 0, message_sent);
     fail_unless(handle.success);
@@ -46,6 +47,7 @@ END_TEST
 
 START_TEST (test_send_single_frame)
 {
+    SHIMS.frame_padding = false;
     const uint8_t payload[] = {0x12, 0x34};
     uint16_t arbitration_id = 0x2a;
     isotp_send(&SHIMS, arbitration_id, payload, sizeof(payload), message_sent);