Bluetooth: refactor set_exp_feature with a feature table

This patch refactors the set_exp_feature with a feature table
consisting of UUIDs and the corresponding callback functions.
In this way, a new experimental feature setting function can be
simply added with its UUID and callback function.
Signed-off-by: Joseph Hwang <josephsih@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

net/bluetooth/mgmt.c

@@ -3892,15 +3892,18 @@ static int exp_debug_feature_changed(bool enabled, struct sock *skip)
 }
 #endif
 
-static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
-			   void *data, u16 data_len)
+#define EXP_FEAT(_uuid, _set_func)	\
+{					\
+	.uuid = _uuid,			\
+	.set_func = _set_func,		\
+}
+
+/* The zero key uuid is special. Multiple exp features are set through it. */
+static int set_zero_key_func(struct sock *sk, struct hci_dev *hdev,
+			     struct mgmt_cp_set_exp_feature *cp, u16 data_len)
 {
-	struct mgmt_cp_set_exp_feature *cp = data;
 	struct mgmt_rp_set_exp_feature rp;
 
-	bt_dev_dbg(hdev, "sock %p", sk);
-
-	if (!memcmp(cp->uuid, ZERO_KEY, 16)) {
 	memset(rp.uuid, 0, 16);
 	rp.flags = cpu_to_le32(0);
 
@@ -3916,8 +3919,7 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
 #endif
 
 	if (hdev && use_ll_privacy(hdev) && !hdev_is_powered(hdev)) {
-			bool changed = hci_dev_test_flag(hdev,
-							 HCI_ENABLE_LL_PRIVACY);
+		bool changed = hci_dev_test_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 
 		hci_dev_clear_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 
@@ -3930,10 +3932,14 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
 	return mgmt_cmd_complete(sk, hdev ? hdev->id : MGMT_INDEX_NONE,
 				 MGMT_OP_SET_EXP_FEATURE, 0,
 				 &rp, sizeof(rp));
-	}
+}
 
 #ifdef CONFIG_BT_FEATURE_DEBUG
-	if (!memcmp(cp->uuid, debug_uuid, 16)) {
+static int set_debug_func(struct sock *sk, struct hci_dev *hdev,
+			  struct mgmt_cp_set_exp_feature *cp, u16 data_len)
+{
+	struct mgmt_rp_set_exp_feature rp;
+
 	bool val, changed;
 	int err;
 
@@ -3972,10 +3978,14 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
 		exp_debug_feature_changed(val, sk);
 
 	return err;
-	}
+}
 #endif
 
-	if (!memcmp(cp->uuid, rpa_resolution_uuid, 16)) {
+static int set_rpa_resolution_func(struct sock *sk, struct hci_dev *hdev,
+				   struct mgmt_cp_set_exp_feature *cp,
+				   u16 data_len)
+{
+	struct mgmt_rp_set_exp_feature rp;
 	bool val, changed;
 	int err;
 	u32 flags;
@@ -4007,16 +4017,14 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
 	val = !!cp->param[0];
 
 	if (val) {
-			changed = !hci_dev_test_flag(hdev,
-						     HCI_ENABLE_LL_PRIVACY);
+		changed = !hci_dev_test_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 		hci_dev_set_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 		hci_dev_clear_flag(hdev, HCI_ADVERTISING);
 
 		/* Enable LL privacy + supported settings changed */
 		flags = BIT(0) | BIT(1);
 	} else {
-			changed = hci_dev_test_flag(hdev,
-						    HCI_ENABLE_LL_PRIVACY);
+		changed = hci_dev_test_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 		hci_dev_clear_flag(hdev, HCI_ENABLE_LL_PRIVACY);
 
 		/* Disable LL privacy + supported settings changed */
@@ -4036,6 +4044,34 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
 		exp_ll_privacy_feature_changed(val, hdev, sk);
 
 	return err;
+}
+
+static const struct mgmt_exp_feature {
+	const u8 *uuid;
+	int (*set_func)(struct sock *sk, struct hci_dev *hdev,
+			struct mgmt_cp_set_exp_feature *cp, u16 data_len);
+} exp_features[] = {
+	EXP_FEAT(ZERO_KEY, set_zero_key_func),
+#ifdef CONFIG_BT_FEATURE_DEBUG
+	EXP_FEAT(debug_uuid, set_debug_func),
+#endif
+	EXP_FEAT(rpa_resolution_uuid, set_rpa_resolution_func),
+
+	/* end with a null feature */
+	EXP_FEAT(NULL, NULL)
+};
+
+static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
+			   void *data, u16 data_len)
+{
+	struct mgmt_cp_set_exp_feature *cp = data;
+	size_t i = 0;
+
+	bt_dev_dbg(hdev, "sock %p", sk);
+
+	for (i = 0; exp_features[i].uuid; i++) {
+		if (!memcmp(cp->uuid, exp_features[i].uuid, 16))
+			return exp_features[i].set_func(sk, hdev, cp, data_len);
 	}
 
 	return mgmt_cmd_status(sk, hdev ? hdev->id : MGMT_INDEX_NONE,