[nrf fromtree] Bluetooth: hci: correct ext adv cmd definition

Update the definition of the set extended advertising data command to be
a variable array instead of hardcoded to the maximum length. This
conforms to the definition from the Bluetooth specification and allows
the corresponding code to be slightly cleaner.

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
(cherry picked from commit 855f4b9)
Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

Author: Jordan Yates

include/zephyr/bluetooth/hci.h

@@ -1326,7 +1326,7 @@ struct bt_hci_cp_le_set_ext_adv_data {
 	uint8_t  op;
 	uint8_t  frag_pref;
 	uint8_t  len;
-	uint8_t  data[251];
+	uint8_t  data[0];
 } __packed;
 
 #define BT_HCI_OP_LE_SET_EXT_SCAN_RSP_DATA      BT_OP(BT_OGF_LE, 0x0038)
@@ -1335,7 +1335,7 @@ struct bt_hci_cp_le_set_ext_scan_rsp_data {
 	uint8_t  op;
 	uint8_t  frag_pref;
 	uint8_t  len;
-	uint8_t  data[251];
+	uint8_t  data[0];
 } __packed;
 
 #define BT_HCI_OP_LE_SET_EXT_ADV_ENABLE         BT_OP(BT_OGF_LE, 0x0039)
@@ -1390,7 +1390,7 @@ struct bt_hci_cp_le_set_per_adv_data {
 	uint8_t  handle;
 	uint8_t  op;
 	uint8_t  len;
-	uint8_t  data[BT_HCI_LE_PER_ADV_FRAG_MAX_LEN];
+	uint8_t  data[0];
 } __packed;
 
 #define BT_HCI_LE_SET_PER_ADV_ENABLE_ENABLE     BIT(0)

subsys/bluetooth/host/adv.c

@@ -556,8 +556,7 @@ static int hci_set_adv_ext_complete(struct bt_le_ext_adv *adv, uint16_t hci_op,
 		total_data_len = BT_GAP_ADV_MAX_ADV_DATA_LEN;
 	}
 
-	cmd_size = total_data_len +
-		   offsetof(struct bt_hci_cp_le_set_ext_adv_data, data);
+	cmd_size = sizeof(*set_data) + total_data_len;
 
 	buf = bt_hci_cmd_create(hci_op, cmd_size);
 	if (!buf) {
@@ -596,9 +595,8 @@ static int hci_set_adv_ext_fragmented(struct bt_le_ext_adv *adv, uint16_t hci_op
 	while (!ad_stream_is_empty(&stream)) {
 		struct bt_hci_cp_le_set_ext_adv_data *set_data;
 		struct net_buf *buf;
-		size_t data_len = MIN(sizeof(set_data->data), stream.remaining_size);
-		const size_t cmd_size = data_len +
-					offsetof(struct bt_hci_cp_le_set_ext_adv_data, data);
+		const size_t data_len = MIN(BT_HCI_LE_EXT_ADV_FRAG_MAX_LEN, stream.remaining_size);
+		const size_t cmd_size = sizeof(*set_data) + data_len;
 		int err;
 
 		buf = bt_hci_cmd_create(hci_op, cmd_size);
@@ -610,7 +608,7 @@ static int hci_set_adv_ext_fragmented(struct bt_le_ext_adv *adv, uint16_t hci_op
 
 		set_data->handle = adv->handle;
 		set_data->frag_pref = BT_HCI_LE_EXT_ADV_FRAG_ENABLED;
-		set_data->len = ad_stream_read(&stream, set_data->data, sizeof(set_data->data));
+		set_data->len = ad_stream_read(&stream, set_data->data, data_len);
 
 		if (is_first_iteration && ad_stream_is_empty(&stream)) {
 			set_data->op = BT_HCI_LE_EXT_ADV_OP_COMPLETE_DATA;
@@ -705,9 +703,8 @@ static int hci_set_per_adv_data(const struct bt_le_ext_adv *adv,
 	while (!ad_stream_is_empty(&stream)) {
 		struct bt_hci_cp_le_set_per_adv_data *set_data;
 		struct net_buf *buf;
-		size_t data_len = MIN(sizeof(set_data->data), stream.remaining_size);
-		const size_t cmd_size = data_len +
-					offsetof(struct bt_hci_cp_le_set_ext_adv_data, data);
+		const size_t data_len = MIN(BT_HCI_LE_PER_ADV_FRAG_MAX_LEN, stream.remaining_size);
+		const size_t cmd_size = sizeof(*set_data) + data_len;
 		int err;
 
 		buf = bt_hci_cmd_create(BT_HCI_OP_LE_SET_PER_ADV_DATA, cmd_size);
@@ -719,7 +716,7 @@ static int hci_set_per_adv_data(const struct bt_le_ext_adv *adv,
 		(void)memset(set_data, 0, cmd_size);
 
 		set_data->handle = adv->handle;
-		set_data->len = ad_stream_read(&stream, set_data->data, sizeof(set_data->data));
+		set_data->len = ad_stream_read(&stream, set_data->data, data_len);
 
 		if (is_first_iteration && ad_stream_is_empty(&stream)) {
 			set_data->op = BT_HCI_LE_EXT_ADV_OP_COMPLETE_DATA;