Bluetooth: Add support for vendor-specific events

Add an event handler for HCI vendor-specific events with the
event code BT_HCI_EVT_VENDOR.

A vendor defined callback can be registered to be called when
vendor-Specific events are received in the stack. The callback can then
decode and handle the event; if not the stack will decode and handle
the event.

Signed-off-by: Thomas Ebert Hansen <thoh@oticon.com>

include/bluetooth/hci.h

@@ -13,6 +13,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <misc/util.h>
+#include <net/buf.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -1914,6 +1915,28 @@ int bt_hci_cmd_send(u16_t opcode, struct net_buf *buf);
 int bt_hci_cmd_send_sync(u16_t opcode, struct net_buf *buf,
 			 struct net_buf **rsp);
 
+/** @typedef bt_hci_vnd_evt_cb_t
+  * @brief Callback type for vendor handling of HCI Vendor-Specific Events.
+  *
+  * A function of this type is registered with bt_hci_register_vnd_evt_cb()
+  * and will be called for any HCI Vendor-Specific Event.
+  *
+  * @param buf Buffer containing event parameters.
+  *
+  * @return true if the function handles the event or false to defer the
+  *         handling of this event back to the stack.
+  */
+typedef bool bt_hci_vnd_evt_cb_t(struct net_buf_simple *buf);
+
+/** Register user callback for HCI Vendor-Specific Events
+  *
+  * @param cb Callback to be called when the stack receives a
+  *           HCI Vendor-Specific Event.
+  *
+  * @return 0 on success or negative error value on failure.
+  */
+int bt_hci_register_vnd_evt_cb(bt_hci_vnd_evt_cb_t cb);
+
 #ifdef __cplusplus
 }
 #endif

subsys/bluetooth/host/Kconfig

@@ -590,3 +590,9 @@ config BT_PAGE_TIMEOUT
 	  (N * 0.625) ms.
 
 endif # BT_BREDR
+
+config BT_HCI_VS_EVT_USER
+	bool "User Vendor-Specific event handling"
+	help
+	  Enable registering a callback for delegating to the user the handling of
+	  VS events that are not known to the stack

subsys/bluetooth/host/hci_core.c

@@ -83,6 +83,10 @@ static bt_ready_cb_t ready_cb;
 
 static bt_le_scan_cb_t *scan_dev_found_cb;
 
+#if defined(CONFIG_BT_HCI_VS_EVT_USER)
+static bt_hci_vnd_evt_cb_t *hci_vnd_evt_cb;
+#endif /* CONFIG_BT_HCI_VS_EVT_USER */
+
 #if defined(CONFIG_BT_ECC)
 static u8_t pub_key[64];
 static struct bt_pub_key_cb *pub_key_cb;
@@ -3370,6 +3374,37 @@ static void le_adv_report(struct net_buf *buf)
 }
 #endif /* CONFIG_BT_OBSERVER */
 
+#if defined(CONFIG_BT_HCI_VS_EVT_USER)
+int bt_hci_register_vnd_evt_cb(bt_hci_vnd_evt_cb_t cb)
+{
+	hci_vnd_evt_cb = cb;
+	return 0;
+}
+#endif /* CONFIG_BT_HCI_VS_EVT_USER */
+
+static void hci_vendor_event(struct net_buf *buf)
+{
+	bool handled = false;
+
+#if defined(CONFIG_BT_HCI_VS_EVT_USER)
+	if (hci_vnd_evt_cb) {
+		struct net_buf_simple_state state;
+
+		net_buf_simple_save(&buf->b, &state);
+
+		handled = hci_vnd_evt_cb(&buf->b);
+
+		net_buf_simple_restore(&buf->b, &state);
+	}
+#endif /* CONFIG_BT_HCI_VS_EVT_USER */
+
+	if (IS_ENABLED(CONFIG_BT_HCI_VS_EXT) && !handled) {
+		/* do nothing at present time */
+		BT_WARN("Unhandled vendor-specific event: %s",
+			bt_hex(buf->data, buf->len));
+	}
+}
+
 static const struct event_handler meta_events[] = {
 #if defined(CONFIG_BT_OBSERVER)
 	EVENT_HANDLER(BT_HCI_EVT_LE_ADVERTISING_REPORT, le_adv_report,
@@ -3422,6 +3457,8 @@ static void hci_le_meta_event(struct net_buf *buf)
 }
 
 static const struct event_handler normal_events[] = {
+	EVENT_HANDLER(BT_HCI_EVT_VENDOR, hci_vendor_event,
+		      sizeof(struct bt_hci_evt_vs)),
 	EVENT_HANDLER(BT_HCI_EVT_LE_META_EVENT, hci_le_meta_event,
 		      sizeof(struct bt_hci_evt_le_meta_event)),
 #if defined(CONFIG_BT_BREDR)