From 0fe29fd1cd77ffbdb8e36ec1715868d9d8011c9b Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Wed, 8 Apr 2015 09:05:27 -0700 Subject: Bluetooth: Read LE remote features during connection establishment When establishing a Bluetooth LE connection, read the remote used features mask to determine which features are supported. This was not really needed with Bluetooth 4.0, but since Bluetooth 4.1 and also 4.2 have introduced new optional features, this becomes more important. This works the same as with BR/EDR where the connection enters the BT_CONFIG stage and hci_connect_cfm call is delayed until the remote features have been retrieved. Only after successfully receiving the remote features, the connection enters the BT_CONNECTED state. Signed-off-by: Marcel Holtmann Signed-off-by: Johan Hedberg --- net/bluetooth/hci_event.c | 107 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 105 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 0103103..7b61be7 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -2036,6 +2036,33 @@ unlock: hci_dev_unlock(hdev); } +static void hci_cs_le_read_remote_features(struct hci_dev *hdev, u8 status) +{ + struct hci_cp_le_read_remote_features *cp; + struct hci_conn *conn; + + BT_DBG("%s status 0x%2.2x", hdev->name, status); + + if (!status) + return; + + cp = hci_sent_cmd_data(hdev, HCI_OP_LE_READ_REMOTE_FEATURES); + if (!cp) + return; + + hci_dev_lock(hdev); + + conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(cp->handle)); + if (conn) { + if (conn->state == BT_CONFIG) { + hci_connect_cfm(conn, status); + hci_conn_drop(conn); + } + } + + hci_dev_unlock(hdev); +} + static void hci_cs_le_start_enc(struct hci_dev *hdev, u8 status) { struct hci_cp_le_start_enc *cp; @@ -3104,6 +3131,10 @@ static void hci_cmd_status_evt(struct hci_dev *hdev, struct sk_buff *skb, hci_cs_le_create_conn(hdev, ev->status); break; + case HCI_OP_LE_READ_REMOTE_FEATURES: + hci_cs_le_read_remote_features(hdev, ev->status); + break; + case HCI_OP_LE_START_ENC: hci_cs_le_start_enc(hdev, ev->status); break; @@ -4515,7 +4546,7 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb) conn->sec_level = BT_SECURITY_LOW; conn->handle = __le16_to_cpu(ev->handle); - conn->state = BT_CONNECTED; + conn->state = BT_CONFIG; conn->le_conn_interval = le16_to_cpu(ev->interval); conn->le_conn_latency = le16_to_cpu(ev->latency); @@ -4524,7 +4555,33 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb) hci_debugfs_create_conn(conn); hci_conn_add_sysfs(conn); - hci_connect_cfm(conn, ev->status); + if (!ev->status) { + /* The remote features procedure is defined for master + * role only. So only in case of an initiated connection + * request the remote features. + * + * If the local controller supports slave-initiated features + * exchange, then requesting the remote features in slave + * role is possible. Otherwise just transition into the + * connected state without requesting the remote features. + */ + if (conn->out || + (hdev->le_features[0] & HCI_LE_SLAVE_FEATURES)) { + struct hci_cp_le_read_remote_features cp; + + cp.handle = __cpu_to_le16(conn->handle); + + hci_send_cmd(hdev, HCI_OP_LE_READ_REMOTE_FEATURES, + sizeof(cp), &cp); + + hci_conn_hold(conn); + } else { + conn->state = BT_CONNECTED; + hci_connect_cfm(conn, ev->status); + } + } else { + hci_connect_cfm(conn, ev->status); + } params = hci_pend_le_action_lookup(&hdev->pend_le_conns, &conn->dst, conn->dst_type); @@ -4826,6 +4883,48 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) hci_dev_unlock(hdev); } +static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev, + struct sk_buff *skb) +{ + struct hci_ev_le_remote_feat_complete *ev = (void *)skb->data; + struct hci_conn *conn; + + BT_DBG("%s status 0x%2.2x", hdev->name, ev->status); + + hci_dev_lock(hdev); + + conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(ev->handle)); + if (conn) { + if (!ev->status) + memcpy(conn->features[0], ev->features, 8); + + if (conn->state == BT_CONFIG) { + __u8 status; + + /* If the local controller supports slave-initiated + * features exchange, but the remote controller does + * not, then it is possible that the error code 0x1a + * for unsupported remote feature gets returned. + * + * In this specific case, allow the connection to + * transition into connected state and mark it as + * successful. + */ + if ((hdev->le_features[0] & HCI_LE_SLAVE_FEATURES) && + !conn->out && ev->status == 0x1a) + status = 0x00; + else + status = ev->status; + + conn->state = BT_CONNECTED; + hci_connect_cfm(conn, status); + hci_conn_drop(conn); + } + } + + hci_dev_unlock(hdev); +} + static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb) { struct hci_ev_le_ltk_req *ev = (void *) skb->data; @@ -4999,6 +5098,10 @@ static void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb) hci_le_adv_report_evt(hdev, skb); break; + case HCI_EV_LE_REMOTE_FEAT_COMPLETE: + hci_le_remote_feat_complete_evt(hdev, skb); + break; + case HCI_EV_LE_LTK_REQ: hci_le_ltk_request_evt(hdev, skb); break; -- cgit v1.1