Addressed reviewer's comment

Author: danielinux

src/test/unit/unit.c

@@ -117,9 +117,8 @@ Suite *wolf_suite(void)
     tcase_add_test(tc_utils, test_wolfip_loopback_send_paths);
     tcase_add_test(tc_utils, test_wolfip_loopback_poll_paths);
     tcase_add_test(tc_utils, test_wolfip_loopback_poll_keeps_pending_on_short_buffer);
-    tcase_add_test(tc_utils, test_wolfip_loopback_poll_null_container);
     tcase_add_test(tc_utils, test_wolfip_loopback_send_drops_oversize);
-    tcase_add_test(tc_utils, test_wolfip_loopback_send_null_container);
+    tcase_add_test(tc_utils, test_wolfip_loopback_send_queue_full_returns_eagain);
     tcase_add_test(tc_utils, test_wolfip_loopback_send_rejects_null_args);
 #endif
     tcase_add_test(tc_utils, test_wolfip_send_port_unreachable_ignores_missing_link_sender);

src/test/unit/unit_tests_proto.c

@@ -3003,8 +3003,9 @@ START_TEST(test_wolfip_loopback_send_paths)
         ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
                          (int)sizeof(frame));
     }
-    /* Next send must be dropped because the queue is full. */
-    ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)), 0);
+    /* Next send must return -WOLFIP_EAGAIN because the queue is full. */
+    ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
+                     -WOLFIP_EAGAIN);
 }
 END_TEST
 
@@ -3054,20 +3055,6 @@ START_TEST(test_wolfip_loopback_poll_keeps_pending_on_short_buffer)
 }
 END_TEST
 
-START_TEST(test_wolfip_loopback_poll_null_container)
-{
-    uintptr_t off = (uintptr_t)offsetof(struct wolfIP, ll_dev);
-    struct wolfIP_ll_dev *ll;
-    uint8_t frame[4] = {0};
-
-    if (off == 0)
-        return;
-
-    ll = (struct wolfIP_ll_dev *)off;
-    ck_assert_int_eq(wolfIP_loopback_poll(ll, frame, sizeof(frame)), 0);
-}
-END_TEST
-
 START_TEST(test_wolfip_loopback_send_drops_oversize)
 {
     struct wolfIP s;
@@ -3086,17 +3073,37 @@ START_TEST(test_wolfip_loopback_send_drops_oversize)
 }
 END_TEST
 
-START_TEST(test_wolfip_loopback_send_null_container)
+START_TEST(test_wolfip_loopback_send_queue_full_returns_eagain)
 {
-    uintptr_t off = (uintptr_t)offsetof(struct wolfIP, ll_dev);
-    struct wolfIP_ll_dev *ll;
-    uint8_t frame[4] = {0};
+    struct wolfIP s;
+    struct wolfIP_ll_dev *loop;
+    uint8_t frame[16] = {0};
+    uint8_t rx[IP_MTU_MAX];
+
+    wolfIP_init(&s);
+    loop = wolfIP_getdev_ex(&s, TEST_LOOPBACK_IF);
+    ck_assert_ptr_nonnull(loop);
+
+    /* Fill the queue completely. */
+    for (unsigned int i = 0; i < WOLFIP_LOOPBACK_QUEUE_DEPTH; i++) {
+        frame[0] = (uint8_t)i;
+        ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
+                         (int)sizeof(frame));
+    }
+
+    /* Queue-full must return -WOLFIP_EAGAIN, not 0. */
+    ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
+                     -WOLFIP_EAGAIN);
 
-    if (off == 0)
-        return;
+    /* Drain one slot and verify we can enqueue again. */
+    ck_assert_int_gt(wolfIP_loopback_poll(loop, rx, sizeof(rx)), 0);
+    frame[0] = 0xFF;
+    ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
+                     (int)sizeof(frame));
 
-    ll = (struct wolfIP_ll_dev *)off;
-    ck_assert_int_eq(wolfIP_loopback_send(ll, frame, sizeof(frame)), -1);
+    /* Queue is full again — must get -WOLFIP_EAGAIN once more. */
+    ck_assert_int_eq(wolfIP_loopback_send(loop, frame, sizeof(frame)),
+                     -WOLFIP_EAGAIN);
 }
 END_TEST
 

src/wolfip.c

@@ -1384,7 +1384,7 @@ static int wolfIP_loopback_send(struct wolfIP_ll_dev *ll, void *buf, uint32_t le
     if (len == 0 || len > IP_MTU_MAX)
         return 0;
     if (s->loopback_count >= WOLFIP_LOOPBACK_QUEUE_DEPTH)
-        return 0; /* queue full, drop */
+        return -WOLFIP_EAGAIN; /* queue full, retry later */
     /* buf is the IP payload (ETH header already stripped by
      * wolfIP_ll_send_frame for non-ethernet devices).
      * Store as-is; wolfIP_poll will re-add the ETH prefix. */