Bluetooth: Connection Parameter Update Procedure

This patch adds support for LE Connection Parameters Request Link
Layer control procedure introduced in Core spec 4.1. This procedure
allows a Peripheral or Central to update the Link Layer connection
parameters of an established connection.

Regarding the acceptance of connection parameters, the LL procedure
follows the same approach of L2CAP procedure (see l2cap_conn_param_
update_req function). We accept any connection parameters values as
long as they are within the valid range.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 58c5930..95b7547 100644 (file)
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -355,6 +355,7 @@ enum {
 #define HCI_LK_AUTH_COMBINATION_P256   0x08
 
 /* ---- HCI Error Codes ---- */
+#define HCI_ERROR_UNKNOWN_CONN_ID      0x02
 #define HCI_ERROR_AUTH_FAILURE         0x05
 #define HCI_ERROR_MEMORY_EXCEEDED      0x07
 #define HCI_ERROR_CONNECTION_TIMEOUT   0x08
@@ -364,6 +365,7 @@ enum {
 #define HCI_ERROR_REMOTE_POWER_OFF     0x15
 #define HCI_ERROR_LOCAL_HOST_TERM      0x16
 #define HCI_ERROR_PAIRING_NOT_ALLOWED  0x18
+#define HCI_ERROR_INVALID_LL_PARAMS    0x1E
 #define HCI_ERROR_ADVERTISING_TIMEOUT  0x3c
 
 /* Flow control modes */
@@ -1305,6 +1307,23 @@ struct hci_rp_le_read_supported_states {
        __u8    le_states[8];
 } __packed;
 
+#define HCI_OP_LE_CONN_PARAM_REQ_REPLY 0x2020
+struct hci_cp_le_conn_param_req_reply {
+       __le16  handle;
+       __le16  interval_min;
+       __le16  interval_max;
+       __le16  latency;
+       __le16  timeout;
+       __le16  min_ce_len;
+       __le16  max_ce_len;
+} __packed;
+
+#define HCI_OP_LE_CONN_PARAM_REQ_NEG_REPLY     0x2021
+struct hci_cp_le_conn_param_req_neg_reply {
+       __le16  handle;
+       __u8    reason;
+} __packed;
+
 /* ---- HCI Events ---- */
 #define HCI_EV_INQUIRY_COMPLETE                0x01
 
@@ -1700,6 +1719,15 @@ struct hci_ev_le_ltk_req {
        __le16  ediv;
 } __packed;
 
+#define HCI_EV_LE_REMOTE_CONN_PARAM_REQ        0x06
+struct hci_ev_le_remote_conn_param_req {
+       __le16 handle;
+       __le16 interval_min;
+       __le16 interval_max;
+       __le16 latency;
+       __le16 timeout;
+} __packed;
+
 /* Advertising report event types */
 #define LE_ADV_IND             0x00
 #define LE_ADV_DIRECT_IND      0x01

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index b0b760d..544e2ef 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4382,6 +4382,52 @@ not_found:
        hci_dev_unlock(hdev);
 }
 
+static void send_conn_param_neg_reply(struct hci_dev *hdev, u16 handle,
+                                     u8 reason)
+{
+       struct hci_cp_le_conn_param_req_neg_reply cp;
+
+       cp.handle = cpu_to_le16(handle);
+       cp.reason = reason;
+
+       hci_send_cmd(hdev, HCI_OP_LE_CONN_PARAM_REQ_NEG_REPLY, sizeof(cp),
+                    &cp);
+}
+
+static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
+                                            struct sk_buff *skb)
+{
+       struct hci_ev_le_remote_conn_param_req *ev = (void *) skb->data;
+       struct hci_cp_le_conn_param_req_reply cp;
+       struct hci_conn *hcon;
+       u16 handle, min, max, latency, timeout;
+
+       handle = le16_to_cpu(ev->handle);
+       min = le16_to_cpu(ev->interval_min);
+       max = le16_to_cpu(ev->interval_max);
+       latency = le16_to_cpu(ev->latency);
+       timeout = le16_to_cpu(ev->timeout);
+
+       hcon = hci_conn_hash_lookup_handle(hdev, handle);
+       if (!hcon || hcon->state != BT_CONNECTED)
+               return send_conn_param_neg_reply(hdev, handle,
+                                                HCI_ERROR_UNKNOWN_CONN_ID);
+
+       if (hci_check_conn_params(min, max, latency, timeout))
+               return send_conn_param_neg_reply(hdev, handle,
+                                                HCI_ERROR_INVALID_LL_PARAMS);
+
+       cp.handle = ev->handle;
+       cp.interval_min = ev->interval_min;
+       cp.interval_max = ev->interval_max;
+       cp.latency = ev->latency;
+       cp.timeout = ev->timeout;
+       cp.min_ce_len = 0;
+       cp.max_ce_len = 0;
+
+       hci_send_cmd(hdev, HCI_OP_LE_CONN_PARAM_REQ_REPLY, sizeof(cp), &cp);
+}
+
 static void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
        struct hci_ev_le_meta *le_ev = (void *) skb->data;
@@ -4405,6 +4451,10 @@ static void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb)
                hci_le_ltk_request_evt(hdev, skb);
                break;
 
+       case HCI_EV_LE_REMOTE_CONN_PARAM_REQ:
+               hci_le_remote_conn_param_req_evt(hdev, skb);
+               break;
+
        default:
                break;
        }