Hi Jakub,
> Currently, when trying to connect to already paired device that just
> rotated its RPA MAC address, old address would be used and connection
> would fail. In order to fix that, kernel must scan and receive
> advertisement with fresh RPA before connecting.
>
> This patch adds hci_connect_le_scan with dependencies, new method that
> will be used to connect to remote LE devices. Instead of just sending
> connect request, it adds a device to whitelist. Later patches will make
> use of this whitelist to send conenct request when advertisement is
> received, and properly handle timeouts.
>
> Signed-off-by: Jakub Pawlowski <jpawlowski@xxxxxxxxxx>
> ---
> include/net/bluetooth/hci_core.h | 5 ++
> net/bluetooth/hci_conn.c | 170 +++++++++++++++++++++++++++++++++++++++
> net/bluetooth/hci_core.c | 32 ++++++++
> 3 files changed, 207 insertions(+)
>
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index c8d2b5a..5d19794 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -826,6 +826,9 @@ void hci_chan_del(struct hci_chan *chan);
> void hci_chan_list_flush(struct hci_conn *conn);
> struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle);
>
> +struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
> + u8 dst_type, u8 sec_level,
> + u16 conn_timeout, u8 role);
> struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
> u8 dst_type, u8 sec_level, u16 conn_timeout,
> u8 role);
> @@ -991,6 +994,8 @@ void hci_conn_params_clear_disabled(struct hci_dev *hdev);
> struct hci_conn_params *hci_pend_le_action_lookup(struct list_head *list,
> bdaddr_t *addr,
> u8 addr_type);
> +struct hci_conn_params *hci_pend_le_explicit_connect_lookup(
> + struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
this is kinda violating the coding style. I wonder if we can shorten the function name or just go over 80 characters this time.
> void hci_uuids_clear(struct hci_dev *hdev);
>
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index 1ba8240..2a13214 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -64,6 +64,36 @@ static void hci_le_create_connection_cancel(struct hci_conn *conn)
> hci_send_cmd(conn->hdev, HCI_OP_LE_CREATE_CONN_CANCEL, 0, NULL);
> }
>
> +/* This function requires the caller holds hdev->lock */
> +static void hci_connect_le_scan_cleanup(struct hci_conn *conn)
> +{
> + struct hci_conn_params *params;
> +
> + params = hci_pend_le_explicit_connect_lookup(conn->hdev, &conn->dst,
> + conn->dst_type);
> + if (!params)
> + return;
> +
> + /* The connection attempt was doing scan for new RPA, and is
> + * in scan phase. If params are not associated with any other
> + * autoconnect action, remove them completely. If they are, just unmark
> + * them as awaiting for connection, by clearing explicit_connect field.
> + */
> + if (params->auto_connect == HCI_AUTO_CONN_EXPLICIT)
> + hci_conn_params_del(conn->hdev, &conn->dst, conn->dst_type);
> + else
> + params->explicit_connect = false;
> +}
What happens if we have two explicit connection requests here. I mean we can have two L2CAP socket trying to connect to two peripherals at the same time.
> +
> +/* This function requires the caller holds hdev->lock */
> +static void hci_connect_le_scan_remove(struct hci_conn *conn)
> +{
> + hci_connect_le_scan_cleanup(conn);
> +
> + hci_conn_hash_del(conn->hdev, conn);
> + hci_update_background_scan(conn->hdev);
> +}
> +
> static void hci_acl_create_connection(struct hci_conn *conn)
> {
> struct hci_dev *hdev = conn->hdev;
> @@ -858,6 +888,146 @@ done:
> return conn;
> }
>
> +static void hci_connect_le_scan_complete(struct hci_dev *hdev, u8 status,
> + u16 opcode)
> +{
> + struct hci_conn *conn;
> +
> + if (status == 0)
> + return;
> +
We prefer if (!status) these days.
> + BT_ERR("Failed to add device to auto conn whitelist: status 0x%2.2x",
> + status);
> +
> + hci_dev_lock(hdev);
> +
> + conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
> + if (!conn)
> + goto done;
> +
> + hci_le_conn_failed(conn, status);
> +
> +done:
Remove the label here. Just move hci_le_conn_failed under if (conn) check.
> + hci_dev_unlock(hdev);
> +}
> +
> +static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
> +{
> + struct hci_conn *conn;
> +
> + conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
> + if (!conn)
> + return false;
> +
> + if (conn->dst_type != type)
> + return false;
> +
> + if (conn->state != BT_CONNECTED)
> + return false;
> +
> + return true;
> +}
> +
> +/* This function requires the caller holds hdev->lock */
> +int hci_explicit_conn_params_set(struct hci_request *req, bdaddr_t *addr,
> + u8 addr_type)
> +{
> + struct hci_dev *hdev = req->hdev;
> + struct hci_conn_params *params;
> +
> + if (is_connected(hdev, addr, addr_type))
> + return -EISCONN;
> +
> + params = hci_conn_params_add(hdev, addr, addr_type);
> + if (!params)
> + return -EIO;
> +
> + /* If we created new params, or exiting params were marked as disabled,
> + * mark them to be used just once to connect.
> + */
> + if (params->auto_connect == HCI_AUTO_CONN_DISABLED) {
> + params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
> + list_del_init(¶ms->action);
> + list_add(¶ms->action, &hdev->pend_le_conns);
> + }
> +
> + params->explicit_connect = true;
> + __hci_update_background_scan(req);
> +
> + BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
> + params->auto_connect);
> +
> + return 0;
> +}
> +
> +/* This function requires the caller holds hdev->lock */
> +struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
> + u8 dst_type, u8 sec_level,
> + u16 conn_timeout, u8 role)
> +{
> + struct hci_conn *conn;
> + struct hci_request req;
> + int err;
> +
> + /* Let's make sure that le is enabled.*/
> + if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
> + if (lmp_le_capable(hdev))
> + return ERR_PTR(-ECONNREFUSED);
> +
> + return ERR_PTR(-EOPNOTSUPP);
> + }
> +
> + /* Some devices send ATT messages as soon as the physical link is
> + * established. To be able to handle these ATT messages, the user-
> + * space first establishes the connection and then starts the pairing
> + * process.
> + *
> + * So if a hci_conn object already exists for the following connection
> + * attempt, we simply update pending_sec_level and auth_type fields
> + * and return the object found.
> + */
> + conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
> + if (conn) {
> + if (conn->pending_sec_level < sec_level)
> + conn->pending_sec_level = sec_level;
> + goto done;
> + }
> +
> + BT_DBG("requesting refresh of dst_addr.");
> +
> + /* We support only one connection attempt at a time. */
> + conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
> + if (conn)
> + return ERR_PTR(-EBUSY);
> +
> + conn = hci_conn_add(hdev, LE_LINK, dst, role);
> + if (!conn)
> + return ERR_PTR(-ENOMEM);
> +
> + hci_req_init(&req, hdev);
> +
> + if (hci_explicit_conn_params_set(&req, dst, dst_type) < 0)
> + return ERR_PTR(-EBUSY);
> +
> + conn->state = BT_CONNECT;
> + set_bit(HCI_CONN_SCANNING, &conn->flags);
> +
> + err = hci_req_run(&req, hci_connect_le_scan_complete);
> + if (err && err != -ENODATA) {
> + hci_conn_del(conn);
> + return ERR_PTR(err);
> + }
> +
> + conn->dst_type = dst_type;
> + conn->sec_level = BT_SECURITY_LOW;
> + conn->pending_sec_level = sec_level;
> + conn->conn_timeout = conn_timeout;
> +
> +done:
> + hci_conn_hold(conn);
> + return conn;
> +}
> +
> struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
> u8 sec_level, u8 auth_type)
> {
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index bc43b64..e322aac 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -2848,6 +2848,29 @@ struct hci_conn_params *hci_pend_le_action_lookup(struct list_head *list,
> }
>
> /* This function requires the caller holds hdev->lock */
> +struct hci_conn_params *hci_pend_le_explicit_connect_lookup(
> + struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
> +{
> + struct hci_conn_params *param;
> +
> + list_for_each_entry(param, &hdev->pend_le_conns, action) {
> + if (bacmp(¶m->addr, addr) == 0 &&
> + param->addr_type == addr_type &&
> + param->explicit_connect)
> + return param;
> + }
> +
> + list_for_each_entry(param, &hdev->pend_le_reports, action) {
> + if (bacmp(¶m->addr, addr) == 0 &&
> + param->addr_type == addr_type &&
> + param->explicit_connect)
> + return param;
> + }
> +
> + return NULL;
> +}
> +
> +/* This function requires the caller holds hdev->lock */
> struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev,
> bdaddr_t *addr, u8 addr_type)
> {
> @@ -2916,6 +2939,15 @@ void hci_conn_params_clear_disabled(struct hci_dev *hdev)
> list_for_each_entry_safe(params, tmp, &hdev->le_conn_params, list) {
> if (params->auto_connect != HCI_AUTO_CONN_DISABLED)
> continue;
> +
> + /* If trying to estabilish one time connection to disabled
> + * device, leave the params, but mark them as just once.
> + */
> + if (params->explicit_connect) {
> + params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
> + continue;
> + }
> +
> list_del(¶ms->list);
> kfree(params);
> }
Regards
Marcel
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