There is a need for certain LE profiles (MIDI for example) to change the
current connection's parameters. In order to do that, this patch
introduces a new BT_LE_CONN_PARAM socket option for SOL_BLUETOOTH
protocol which allow user-space l2cap sockets to update the current
connection.
It necessary to expose all the connection parameters to user-space
because user-space are exposed to those values anyway, via PPCP
characteristic or particular profile specification.
If ROLE is SLAVE, then it will send a L2CAP_CONN_PARAM_UPDATE_REQ
signaling command to the MASTER, triggering proper LE parameter update
procedure. The connection parameters update will only occur upon a
successful L2CAP_CONN_PARAM_UPDATE_RSP sent by the MASTER.
If ROLE is MASTER, then immediately update the connection parameters.
Once the connection parameters are effective, a MGMT_EV_NEW_CONN_PARAM
event with the store_hint set is sent to user-space so an application
can store the connection parameters for persistence reasons.
Signed-off-by: Felipe F. Tonello <e...@felipetonello.com>
---
include/net/bluetooth/bluetooth.h | 8 +++
net/bluetooth/l2cap_sock.c | 110 ++++++++++++++++++++++++++++++++++++++
2 files changed, 118 insertions(+)
diff --git a/include/net/bluetooth/bluetooth.h
b/include/net/bluetooth/bluetooth.h
index 01487192f628..ce5b3abd3b27 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -122,6 +122,14 @@ struct bt_voice {
#define BT_SNDMTU 12
#define BT_RCVMTU 13
+#define BT_LE_CONN_PARAM 14
+struct bt_le_conn_param {
+ __u16 min_interval;
+ __u16 max_interval;
+ __u16 latency;
+ __u16 supervision_timeout;
+};
+
__printf(1, 2)
void bt_info(const char *fmt, ...);
__printf(1, 2)
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 507b80d59dec..1e096bd9ddde 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -515,6 +515,47 @@ static int l2cap_sock_getsockopt(struct socket *sock, int
level, int optname,
lock_sock(sk);
switch (optname) {
+ case BT_LE_CONN_PARAM: {
+ struct bt_le_conn_param conn_param;
+ struct hci_conn_params *params;
+ struct hci_conn *hcon;
+ struct hci_dev *hdev;
+
+ if (!chan->conn) {
+ err = -ENOTCONN;
+ break;
+ }
+
+ hcon = chan->conn->hcon;
+ hdev = hcon->hdev;
+ hci_dev_lock(hdev);
+
+ params = hci_conn_params_lookup(hdev, &hcon->dst,
+ hcon->dst_type);
+
+ memset(&conn_param, 0, sizeof(conn_param));
+
+ if (params) {
+ conn_param.min_interval = params->conn_min_interval;
+ conn_param.max_interval = params->conn_max_interval;
+ conn_param.latency = params->conn_latency;
+ conn_param.supervision_timeout =
+ params->supervision_timeout;
+ } else {
+ conn_param.min_interval = hdev->le_conn_min_interval;
+ conn_param.max_interval = hdev->le_conn_max_interval;
+ conn_param.latency = hdev->le_conn_latency;
+ conn_param.supervision_timeout = hdev->le_supv_timeout;
+ }
+
+ hci_dev_unlock(hdev);
+
+ len = min_t(unsigned int, len, sizeof(conn_param));
+ if (copy_to_user(optval, (char *)&conn_param, len))
+ err = -EFAULT;
+
+ break;
+ }
case BT_SECURITY:
if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
chan->chan_type != L2CAP_CHAN_FIXED &&
@@ -762,6 +803,75 @@ static int l2cap_sock_setsockopt(struct socket *sock, int
level, int optname,
lock_sock(sk);
switch (optname) {
+ case BT_LE_CONN_PARAM: {
+ struct bt_le_conn_param conn_param;
+ struct hci_conn_params *hci_param;
+ struct hci_conn *hcon;
+ struct hci_dev *hdev;
+
+ len = min_t(unsigned int, sizeof(conn_param), optlen);
+ if (copy_from_user((char *)&conn_param, optval, len)) {
+ err = -EFAULT;
+ break;
+ }
+
+ if (!chan->conn) {
+ err = -ENOTCONN;
+ break;
+ }
+
+ err = hci_check_conn_params(conn_param.min_interval,
+ conn_param.max_interval,
+ conn_param.latency,
+ conn_param.supervision_timeout);
+ if (err < 0) {
+ BT_ERR("Ignoring invalid connection parameters");
+ break;
+ }
+
+ hcon = chan->conn->hcon;
+ hdev = hcon->hdev;
+
+ hci_dev_lock(hdev);
+
+ /* we add new param in case it doesn't exist */
+ hci_param = hci_conn_params_add(hdev, &hcon->dst,
+ hcon->dst_type);
+ if (!hci_param) {
+ err = -ENOMEM;
+ BT_ERR("Failed to add connection parameters");
+ hci_dev_unlock(hcon->hdev);
+ break;
+ }
+
+ hci_dev_unlock(hdev);
+
+ /* Send a L2CAP connection parameters update request, if
+ * the host role is slave.
+ */
+ if (hcon->role == HCI_ROLE_SLAVE) {
+ l2cap_le_conn_update_req(chan->conn,
+ conn_param.min_interval,
+ conn_param.max_interval,
+ conn_param.latency,
+
conn_param.supervision_timeout);
+ } else {
+ /* this function also updates the hci_param value */
+ hci_le_conn_update(hcon, conn_param.min_interval,
+ conn_param.max_interval,
+ conn_param.latency,
+ conn_param.supervision_timeout);
+
+ /* don't set the `store' hint */
+ mgmt_new_conn_param(hdev, &hcon->dst, hcon->dst_type,
+ false, conn_param.min_interval,
+ conn_param.max_interval,
+ conn_param.latency,
+ conn_param.supervision_timeout);
+ }
+ break;
+ }
+
case BT_SECURITY:
if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
chan->chan_type != L2CAP_CHAN_FIXED &&
--
2.12.2
