Bluetooth: HCI: Fix not always setting Scan Response/Advertising Data

The scan response and advertising data needs to be tracked on a per
instance (adv_info) since when these instaces are removed so are their
data, to fix that new flags are introduced which is used to mark when
the data changes and then checked to confirm when the data needs to be
synced with the controller.
Tested-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/hci_core.h

@@ -243,8 +243,10 @@ struct adv_info {
 	__u16	duration;
 	__u16	adv_data_len;
 	__u8	adv_data[HCI_MAX_EXT_AD_LENGTH];
+	bool	adv_data_changed;
 	__u16	scan_rsp_len;
 	__u8	scan_rsp_data[HCI_MAX_EXT_AD_LENGTH];
+	bool	scan_rsp_changed;
 	__s8	tx_power;
 	__u32   min_interval;
 	__u32   max_interval;
@@ -258,6 +260,15 @@ struct adv_info {
 
 #define HCI_ADV_TX_POWER_NO_PREFERENCE 0x7F
 
+#define DATA_CMP(_d1, _l1, _d2, _l2) \
+	(_l1 == _l2 ? memcmp(_d1, _d2, _l1) : _l1 - _l2)
+
+#define ADV_DATA_CMP(_adv, _data, _len) \
+	DATA_CMP((_adv)->adv_data, (_adv)->adv_data_len, _data, _len)
+
+#define SCAN_RSP_CMP(_adv, _data, _len) \
+	DATA_CMP((_adv)->scan_rsp_data, (_adv)->scan_rsp_len, _data, _len)
+
 struct monitored_device {
 	struct list_head list;
 

net/bluetooth/hci_core.c

@@ -1728,18 +1728,12 @@ int hci_add_adv_instance(struct hci_dev *hdev, u8 instance, u32 flags,
 	}
 
 	adv_instance->flags = flags;
-	adv_instance->adv_data_len = adv_data_len;
-	adv_instance->scan_rsp_len = scan_rsp_len;
 	adv_instance->min_interval = min_interval;
 	adv_instance->max_interval = max_interval;
 	adv_instance->tx_power = tx_power;
 
-	if (adv_data_len)
-		memcpy(adv_instance->adv_data, adv_data, adv_data_len);
-
-	if (scan_rsp_len)
-		memcpy(adv_instance->scan_rsp_data,
-		       scan_rsp_data, scan_rsp_len);
+	hci_set_adv_instance_data(hdev, instance, adv_data_len, adv_data,
+				  scan_rsp_len, scan_rsp_data);
 
 	adv_instance->timeout = timeout;
 	adv_instance->remaining_time = timeout;
@@ -1762,29 +1756,33 @@ int hci_set_adv_instance_data(struct hci_dev *hdev, u8 instance,
 			      u16 adv_data_len, u8 *adv_data,
 			      u16 scan_rsp_len, u8 *scan_rsp_data)
 {
-	struct adv_info *adv_instance;
+	struct adv_info *adv;
 
-	adv_instance = hci_find_adv_instance(hdev, instance);
+	adv = hci_find_adv_instance(hdev, instance);
 
 	/* If advertisement doesn't exist, we can't modify its data */
-	if (!adv_instance)
+	if (!adv)
 		return -ENOENT;
 
-	if (adv_data_len) {
-		memset(adv_instance->adv_data, 0,
-		       sizeof(adv_instance->adv_data));
-		memcpy(adv_instance->adv_data, adv_data, adv_data_len);
-		adv_instance->adv_data_len = adv_data_len;
+	if (adv_data_len && ADV_DATA_CMP(adv, adv_data, adv_data_len)) {
+		memset(adv->adv_data, 0, sizeof(adv->adv_data));
+		memcpy(adv->adv_data, adv_data, adv_data_len);
+		adv->adv_data_len = adv_data_len;
+		adv->adv_data_changed = true;
 	}
 
-	if (scan_rsp_len) {
-		memset(adv_instance->scan_rsp_data, 0,
-		       sizeof(adv_instance->scan_rsp_data));
-		memcpy(adv_instance->scan_rsp_data,
-		       scan_rsp_data, scan_rsp_len);
-		adv_instance->scan_rsp_len = scan_rsp_len;
+	if (scan_rsp_len && SCAN_RSP_CMP(adv, scan_rsp_data, scan_rsp_len)) {
+		memset(adv->scan_rsp_data, 0, sizeof(adv->scan_rsp_data));
+		memcpy(adv->scan_rsp_data, scan_rsp_data, scan_rsp_len);
+		adv->scan_rsp_len = scan_rsp_len;
+		adv->scan_rsp_changed = true;
 	}
 
+	/* Mark as changed if there are flags which would affect it */
+	if (((adv->flags & MGMT_ADV_FLAG_APPEARANCE) && hdev->appearance) ||
+	    adv->flags & MGMT_ADV_FLAG_LOCAL_NAME)
+		adv->scan_rsp_changed = true;
+
 	return 0;
 }
 

net/bluetooth/hci_sync.c

@@ -849,26 +849,38 @@ static int hci_set_ext_scan_rsp_data_sync(struct hci_dev *hdev, u8 instance)
 		u8 data[HCI_MAX_EXT_AD_LENGTH];
 	} pdu;
 	u8 len;
+	struct adv_info *adv = NULL;
+	int err;
 
 	memset(&pdu, 0, sizeof(pdu));
 
-	len = eir_create_scan_rsp(hdev, instance, pdu.data);
-
-	if (hdev->scan_rsp_data_len == len &&
-	    !memcmp(pdu.data, hdev->scan_rsp_data, len))
-		return 0;
+	if (instance) {
+		adv = hci_find_adv_instance(hdev, instance);
+		if (!adv || !adv->scan_rsp_changed)
+			return 0;
+	}
 
-	memcpy(hdev->scan_rsp_data, pdu.data, len);
-	hdev->scan_rsp_data_len = len;
+	len = eir_create_scan_rsp(hdev, instance, pdu.data);
 
 	pdu.cp.handle = instance;
 	pdu.cp.length = len;
 	pdu.cp.operation = LE_SET_ADV_DATA_OP_COMPLETE;
 	pdu.cp.frag_pref = LE_SET_ADV_DATA_NO_FRAG;
 
-	return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_SCAN_RSP_DATA,
-				     sizeof(pdu.cp) + len, &pdu.cp,
-				     HCI_CMD_TIMEOUT);
+	err = __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_SCAN_RSP_DATA,
+				    sizeof(pdu.cp) + len, &pdu.cp,
+				    HCI_CMD_TIMEOUT);
+	if (err)
+		return err;
+
+	if (adv) {
+		adv->scan_rsp_changed = false;
+	} else {
+		memcpy(hdev->scan_rsp_data, pdu.data, len);
+		hdev->scan_rsp_data_len = len;
+	}
+
+	return 0;
 }
 
 static int __hci_set_scan_rsp_data_sync(struct hci_dev *hdev, u8 instance)
@@ -1119,27 +1131,39 @@ static int hci_set_ext_adv_data_sync(struct hci_dev *hdev, u8 instance)
 		u8 data[HCI_MAX_EXT_AD_LENGTH];
 	} pdu;
 	u8 len;
+	struct adv_info *adv = NULL;
+	int err;
 
 	memset(&pdu, 0, sizeof(pdu));
 
-	len = eir_create_adv_data(hdev, instance, pdu.data);
-
-	/* There's nothing to do if the data hasn't changed */
-	if (hdev->adv_data_len == len &&
-	    memcmp(pdu.data, hdev->adv_data, len) == 0)
-		return 0;
+	if (instance) {
+		adv = hci_find_adv_instance(hdev, instance);
+		if (!adv || !adv->adv_data_changed)
+			return 0;
+	}
 
-	memcpy(hdev->adv_data, pdu.data, len);
-	hdev->adv_data_len = len;
+	len = eir_create_adv_data(hdev, instance, pdu.data);
 
 	pdu.cp.length = len;
 	pdu.cp.handle = instance;
 	pdu.cp.operation = LE_SET_ADV_DATA_OP_COMPLETE;
 	pdu.cp.frag_pref = LE_SET_ADV_DATA_NO_FRAG;
 
-	return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_ADV_DATA,
-				     sizeof(pdu.cp) + len, &pdu.cp,
-				     HCI_CMD_TIMEOUT);
+	err = __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_ADV_DATA,
+				    sizeof(pdu.cp) + len, &pdu.cp,
+				    HCI_CMD_TIMEOUT);
+	if (err)
+		return err;
+
+	/* Update data if the command succeed */
+	if (adv) {
+		adv->adv_data_changed = false;
+	} else {
+		memcpy(hdev->adv_data, pdu.data, len);
+		hdev->adv_data_len = len;
+	}
+
+	return 0;
 }
 
 static int hci_set_adv_data_sync(struct hci_dev *hdev, u8 instance)