Bluetooth: Add support for setting LE advertising data

This patch adds support for setting basing LE advertising data. The
three elements supported for now are the advertising flags, the TX power
and the friendly name.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

include/net/bluetooth/hci.h

@@ -338,6 +338,13 @@ enum {
 #define EIR_SSP_RAND_R		0x0F /* Simple Pairing Randomizer R */
 #define EIR_DEVICE_ID		0x10 /* device ID */
 
+/* Low Energy Advertising Flags */
+#define LE_AD_LIMITED		0x01 /* Limited Discoverable */
+#define LE_AD_GENERAL		0x02 /* General Discoverable */
+#define LE_AD_NO_BREDR		0x04 /* BR/EDR not supported */
+#define LE_AD_SIM_LE_BREDR_CTRL	0x08 /* Simultaneous LE & BR/EDR Controller */
+#define LE_AD_SIM_LE_BREDR_HOST	0x10 /* Simultaneous LE & BR/EDR Host */
+
 /* -----  HCI Commands ---- */
 #define HCI_OP_NOP			0x0000
 
@@ -942,6 +949,14 @@ struct hci_rp_le_read_adv_tx_power {
 	__s8	tx_power;
 } __packed;
 
+#define HCI_MAX_AD_LENGTH		31
+
+#define HCI_OP_LE_SET_ADV_DATA		0x2008
+struct hci_cp_le_set_adv_data {
+	__u8	length;
+	__u8	data[HCI_MAX_AD_LENGTH];
+} __packed;
+
 #define HCI_OP_LE_SET_SCAN_PARAM	0x200b
 struct hci_cp_le_set_scan_param {
 	__u8    type;

include/net/bluetooth/hci_core.h

@@ -279,6 +279,8 @@ struct hci_dev {
 	struct le_scan_params	le_scan_params;
 
 	__s8			adv_tx_power;
+	__u8			adv_data[HCI_MAX_AD_LENGTH];
+	__u8			adv_data_len;
 
 	int (*open)(struct hci_dev *hdev);
 	int (*close)(struct hci_dev *hdev);
@@ -734,6 +736,8 @@ int hci_add_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 *hash,
 								u8 *randomizer);
 int hci_remove_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr);
 
+int hci_update_ad(struct hci_dev *hdev);
+
 void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
 
 int hci_recv_frame(struct sk_buff *skb);

net/bluetooth/hci_core.c

@@ -594,6 +594,99 @@ done:
 	return err;
 }
 
+static u8 create_ad(struct hci_dev *hdev, u8 *ptr)
+{
+	u8 ad_len = 0, flags = 0;
+	size_t name_len;
+
+	if (test_bit(HCI_LE_PERIPHERAL, &hdev->dev_flags))
+		flags |= LE_AD_GENERAL;
+
+	if (!lmp_bredr_capable(hdev))
+		flags |= LE_AD_NO_BREDR;
+
+	if (lmp_le_br_capable(hdev))
+		flags |= LE_AD_SIM_LE_BREDR_CTRL;
+
+	if (lmp_host_le_br_capable(hdev))
+		flags |= LE_AD_SIM_LE_BREDR_HOST;
+
+	if (flags) {
+		BT_DBG("adv flags 0x%02x", flags);
+
+		ptr[0] = 2;
+		ptr[1] = EIR_FLAGS;
+		ptr[2] = flags;
+
+		ad_len += 3;
+		ptr += 3;
+	}
+
+	if (hdev->adv_tx_power != HCI_TX_POWER_INVALID) {
+		ptr[0] = 2;
+		ptr[1] = EIR_TX_POWER;
+		ptr[2] = (u8) hdev->adv_tx_power;
+
+		ad_len += 3;
+		ptr += 3;
+	}
+
+	name_len = strlen(hdev->dev_name);
+	if (name_len > 0) {
+		size_t max_len = HCI_MAX_AD_LENGTH - ad_len - 2;
+
+		if (name_len > max_len) {
+			name_len = max_len;
+			ptr[1] = EIR_NAME_SHORT;
+		} else
+			ptr[1] = EIR_NAME_COMPLETE;
+
+		ptr[0] = name_len + 1;
+
+		memcpy(ptr + 2, hdev->dev_name, name_len);
+
+		ad_len += (name_len + 2);
+		ptr += (name_len + 2);
+	}
+
+	return ad_len;
+}
+
+int hci_update_ad(struct hci_dev *hdev)
+{
+	struct hci_cp_le_set_adv_data cp;
+	u8 len;
+	int err;
+
+	hci_dev_lock(hdev);
+
+	if (!lmp_le_capable(hdev)) {
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	memset(&cp, 0, sizeof(cp));
+
+	len = create_ad(hdev, cp.data);
+
+	if (hdev->adv_data_len == len &&
+	    memcmp(cp.data, hdev->adv_data, len) == 0) {
+		err = 0;
+		goto unlock;
+	}
+
+	memcpy(hdev->adv_data, cp.data, sizeof(cp.data));
+	hdev->adv_data_len = len;
+
+	cp.length = len;
+	err = hci_send_cmd(hdev, HCI_OP_LE_SET_ADV_DATA, sizeof(cp), &cp);
+
+unlock:
+	hci_dev_unlock(hdev);
+
+	return err;
+}
+
 /* ---- HCI ioctl helpers ---- */
 
 int hci_dev_open(__u16 dev)
@@ -651,6 +744,7 @@ int hci_dev_open(__u16 dev)
 		hci_dev_hold(hdev);
 		set_bit(HCI_UP, &hdev->flags);
 		hci_notify(hdev, HCI_DEV_UP);
+		hci_update_ad(hdev);
 		if (!test_bit(HCI_SETUP, &hdev->dev_flags) &&
 		    mgmt_valid_hdev(hdev)) {
 			hci_dev_lock(hdev);

net/bluetooth/hci_event.c

@@ -204,6 +204,9 @@ static void hci_cc_reset(struct hci_dev *hdev, struct sk_buff *skb)
 	hdev->discovery.state = DISCOVERY_STOPPED;
 	hdev->inq_tx_power = HCI_TX_POWER_INVALID;
 	hdev->adv_tx_power = HCI_TX_POWER_INVALID;
+
+	memset(hdev->adv_data, 0, sizeof(hdev->adv_data));
+	hdev->adv_data_len = 0;
 }
 
 static void hci_cc_write_local_name(struct hci_dev *hdev, struct sk_buff *skb)
@@ -226,6 +229,9 @@ static void hci_cc_write_local_name(struct hci_dev *hdev, struct sk_buff *skb)
 
 	hci_dev_unlock(hdev);
 
+	if (!status && !test_bit(HCI_INIT, &hdev->flags))
+		hci_update_ad(hdev);
+
 	hci_req_complete(hdev, HCI_OP_WRITE_LOCAL_NAME, status);
 }
 
@@ -1091,8 +1097,11 @@ static void hci_cc_le_read_adv_tx_power(struct hci_dev *hdev,
 
 	BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);
 
-	if (!rp->status)
+	if (!rp->status) {
 		hdev->adv_tx_power = rp->tx_power;
+		if (!test_bit(HCI_INIT, &hdev->flags))
+			hci_update_ad(hdev);
+	}
 
 	hci_req_complete(hdev, HCI_OP_LE_READ_ADV_TX_POWER, rp->status);
 }