Bluetooth: le_simult_central_peripheral experimental feature

This patch adds an le_simult_central_peripheral features which allows a
clients to determine if the controller is able to support peripheral and
central connections separately and at the same time.
Signed-off-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/mgmt.c

@@ -3753,12 +3753,19 @@ static const u8 debug_uuid[16] = {
 };
 #endif
 
+/* 671b10b5-42c0-4696-9227-eb28d1b049d6 */
+static const u8 simult_central_periph_uuid[16] = {
+	0xd6, 0x49, 0xb0, 0xd1, 0x28, 0xeb, 0x27, 0x92,
+	0x96, 0x46, 0xc0, 0x42, 0xb5, 0x10, 0x1b, 0x67,
+};
+
 static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
 				  void *data, u16 data_len)
 {
-	char buf[42];
+	char buf[44];
 	struct mgmt_rp_read_exp_features_info *rp = (void *)buf;
 	u16 idx = 0;
+	u32 flags;
 
 	bt_dev_dbg(hdev, "sock %p", sk);
 
@@ -3766,7 +3773,7 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
 
 #ifdef CONFIG_BT_FEATURE_DEBUG
 	if (!hdev) {
-		u32 flags = bt_dbg_get() ? BIT(0) : 0;
+		flags = bt_dbg_get() ? BIT(0) : 0;
 
 		memcpy(rp->features[idx].uuid, debug_uuid, 16);
 		rp->features[idx].flags = cpu_to_le32(flags);
@@ -3774,6 +3781,20 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
 	}
 #endif
 
+	if (hdev) {
+		if (test_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks) &&
+		    (hdev->le_states[4] & 0x08) &&	/* Central */
+		    (hdev->le_states[4] & 0x40) &&	/* Peripheral */
+		    (hdev->le_states[3] & 0x10))	/* Simultaneous */
+			flags = BIT(0);
+		else
+			flags = 0;
+
+		memcpy(rp->features[idx].uuid, simult_central_periph_uuid, 16);
+		rp->features[idx].flags = cpu_to_le32(flags);
+		idx++;
+	}
+
 	rp->feature_count = cpu_to_le16(idx);
 
 	/* After reading the experimental features information, enable