net: buf: Add fragmentation API tests

Add tests for checking that the net_buf fragmentation works ok.

Change-Id: I778f79bae971314b6f19c1bf00ed42e1c2128e99
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

tests/net/buf/src/main.c

@@ -43,8 +43,11 @@ struct bt_data {
 };
 
 static int destroy_called;
+static int frag_destroy_called;
 
 static struct nano_fifo bufs_fifo;
+static struct nano_fifo no_data_buf_fifo;
+static struct nano_fifo frags_fifo;
 
 static void buf_destroy(struct net_buf *buf)
 {
@@ -59,9 +62,25 @@ static void buf_destroy(struct net_buf *buf)
 	nano_fifo_put(buf->free, buf);
 }
 
+static void frag_destroy(struct net_buf *buf)
+{
+	frag_destroy_called++;
+
+	if (buf->free != &frags_fifo) {
+		printk("Invalid free frag pointer in buffer!\n");
+	} else {
+		nano_fifo_put(buf->free, buf);
+	}
+}
+
 static NET_BUF_POOL(bufs_pool, 22, 74, &bufs_fifo, buf_destroy,
 		    sizeof(struct bt_data));
 
+static NET_BUF_POOL(no_data_buf_pool, 1, 0, &no_data_buf_fifo, NULL,
+		    sizeof(struct bt_data));
+
+static NET_BUF_POOL(frags_pool, 13, 128, &frags_fifo, frag_destroy, 0);
+
 static bool net_buf_test_1(void)
 {
 	struct net_buf *bufs[ARRAY_SIZE(bufs_pool)];
@@ -154,8 +173,9 @@ static void test_3_fiber(int arg1, int arg2)
 	net_buf_unref(buf);
 
 	if (destroy_called != ARRAY_SIZE(bufs_pool)) {
-		printk("Incorrect fragment destroy callback count: %d\n",
-		       destroy_called);
+		printk("Incorrect fragment destroy callback count: %d "
+		       "should be %d\n", destroy_called,
+		       ARRAY_SIZE(bufs_pool));
 		return;
 	}
 
@@ -214,6 +234,160 @@ static bool net_buf_test_3(void)
 	return true;
 }
 
+static bool net_buf_test_4(void)
+{
+	struct net_buf *frags[ARRAY_SIZE(frags_pool)];
+	struct net_buf *buf, *frag;
+	int i, removed;
+
+	DBG("sizeof(struct net_buf) = %u\n", sizeof(struct net_buf));
+	DBG("sizeof(frags_pool)     = %u\n", sizeof(frags_pool));
+
+	net_buf_pool_init(no_data_buf_pool);
+	net_buf_pool_init(frags_pool);
+
+	/* Create a buf that does not have any data to store, it just
+	 * contains link to fragments.
+	 */
+	buf = net_buf_get(&no_data_buf_fifo, 0);
+
+	if (buf->size != 0) {
+		DBG("Invalid buf size %d\n", buf->size);
+		return false;
+	}
+
+	/* Test the fragments by appending after last fragment */
+	for (i = 0; i < ARRAY_SIZE(frags_pool) - 1; i++) {
+		frag = net_buf_get(&frags_fifo, 0);
+		net_buf_frag_add(buf, frag);
+		frags[i] = frag;
+	}
+
+	/* And one as a first fragment */
+	frag = net_buf_get(&frags_fifo, 0);
+	net_buf_frag_insert(buf, frag);
+	frags[i] = frag;
+
+	frag = buf->frags;
+
+	if (frag->user_data_size != 0) {
+		DBG("Invalid user data size %d\n", frag->user_data_size);
+		return false;
+	}
+
+	i = 0;
+	while (frag) {
+		frag = frag->frags;
+		i++;
+	}
+
+	if (i != ARRAY_SIZE(frags_pool)) {
+		DBG("Incorrect fragment count: %d vs %d\n",
+		    i, ARRAY_SIZE(frags_pool));
+		return false;
+	}
+
+	/* Remove about half of the fragments and verify count */
+	i = removed = 0;
+	frag = buf->frags;
+	while (frag) {
+		struct net_buf *next = frag->frags;
+
+		if ((i % 2) && next) {
+			net_buf_frag_del(frag, next);
+			net_buf_unref(next);
+			removed++;
+		} else {
+			frag = next;
+		}
+		i++;
+	}
+
+	i = 0;
+	frag = buf->frags;
+	while (frag) {
+		frag = frag->frags;
+		i++;
+	}
+
+	if ((i + removed) != ARRAY_SIZE(frags_pool)) {
+		DBG("Incorrect removed fragment count: %d vs %d\n",
+		       i + removed, ARRAY_SIZE(frags_pool));
+		return false;
+	}
+
+	removed = 0;
+
+	while (buf->frags) {
+		struct net_buf *frag = buf->frags;
+
+		net_buf_frag_del(buf, frag);
+		net_buf_unref(frag);
+		removed++;
+	}
+
+	if (removed != i) {
+		DBG("Not all fragments were removed: %d vs %d\n",
+		       i, removed);
+		return false;
+	}
+
+	if (frag_destroy_called != ARRAY_SIZE(frags_pool)) {
+		DBG("Incorrect frag destroy callback count: %d vs %d\n",
+		    frag_destroy_called, ARRAY_SIZE(frags_pool));
+		return false;
+	}
+
+	/* Add the fragments back and verify that they are properly unref
+	 * by freeing the top buf.
+	 */
+	for (i = 0; i < ARRAY_SIZE(frags_pool) - 3; i++) {
+		net_buf_frag_add(buf, net_buf_get(&frags_fifo, 0));
+	}
+
+	/* Create a fragment list and add it to frags list after first
+	 * element
+	 */
+	frag = net_buf_get(&frags_fifo, 0);
+	net_buf_frag_add(frag, net_buf_get(&frags_fifo, 0));
+	net_buf_frag_insert(frag, net_buf_get(&frags_fifo, 0));
+	net_buf_frag_insert(buf->frags->frags, frag);
+
+	i = 0;
+	frag = buf->frags;
+	while (frag) {
+		frag = frag->frags;
+		i++;
+	}
+
+	if (i != ARRAY_SIZE(frags_pool)) {
+		DBG("Incorrect fragment count: %d vs %d\n",
+		    i, ARRAY_SIZE(frags_pool));
+		return false;
+	}
+
+	frag_destroy_called = 0;
+
+	net_buf_unref(buf);
+
+	if (frag_destroy_called != 0) {
+		DBG("Wrong frag destroy callback count\n");
+		return false;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(frags_pool); i++) {
+		net_buf_unref(frags[i]);
+	}
+
+	if (frag_destroy_called != ARRAY_SIZE(frags_pool)) {
+		DBG("Incorrect frag destroy count: %d vs %d\n",
+		    frag_destroy_called, ARRAY_SIZE(frags_pool));
+		return false;
+	}
+
+	return true;
+}
+
 static const struct {
 	const char *name;
 	bool (*func)(void);
@@ -221,6 +395,7 @@ static const struct {
 	{ "Test 1", net_buf_test_1, },
 	{ "Test 2", net_buf_test_2, },
 	{ "Test 3", net_buf_test_3, },
+	{ "Test 4", net_buf_test_4, },
 };
 
 void main(void)