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_CONFIG socket option for SOL_BLUETOOTH
protocol which allow user-space l2cap sockets to update the current
connection.
The current options exported to user-space are default, low and high
latency. Internally, when a custom latency is used when the connection
parameters are set by MGMT_OP_LOAD_CONN_PARAM.
If ROLE is SLAVE, then it will also send a L2CAP_CONN_PARAM_UPDATE_REQ
signaling command to the MASTER, triggering proper 4.0 parameter update
procedure.
This option will also send a MGMT_EV_NEW_CONN_PARAM event with the
store_hint set so the user-space application can store the connection
parameters for persistence reasons.
Note: Connection Parameters Request Link Layer Control Procedure is not
supported by BlueZ yet.
Signed-off-by: Felipe F. Tonello <eu@xxxxxxxxxxxxxxxxx>
---
include/net/bluetooth/bluetooth.h | 9 ++++
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_core.c | 1 +
net/bluetooth/l2cap_sock.c | 109 ++++++++++++++++++++++++++++++++++++++
net/bluetooth/mgmt.c | 1 +
5 files changed, 121 insertions(+)
diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 01487192f628..ff63b85859ff 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -122,6 +122,15 @@ struct bt_voice {
#define BT_SNDMTU 12
#define BT_RCVMTU 13
+#define BT_LE_CONN_CONFIG 14
+enum bt_le_conn_config {
+ BT_LE_CONN_CONFIG_DEFAULT_LATENCY = 0,
+ BT_LE_CONN_CONFIG_LOW_LATENCY,
+ BT_LE_CONN_CONFIG_HIGH_LATENCY,
+ /* Kernel-only configuration */
+ BT_LE_CONN_CONFIG_CUSTOM_LATENCY = 100,
+};
+
__printf(1, 2)
void bt_info(const char *fmt, ...);
__printf(1, 2)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 554671c81f4a..c4ed995ebace 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -522,6 +522,7 @@ struct hci_conn_params {
u16 conn_max_interval;
u16 conn_latency;
u16 supervision_timeout;
+ enum bt_le_conn_config conn_config;
enum {
HCI_AUTO_CONN_DISABLED,
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 3ac89e9ace71..832d7a2cbec3 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2824,6 +2824,7 @@ struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev,
params->conn_latency = hdev->le_conn_latency;
params->supervision_timeout = hdev->le_supv_timeout;
params->auto_connect = HCI_AUTO_CONN_DISABLED;
+ params->conn_config = BT_LE_CONN_CONFIG_DEFAULT_LATENCY;
BT_DBG("addr %pMR (type %u)", addr, addr_type);
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index a8ba752732c9..1bad51a4e28b 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -514,6 +514,35 @@ static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname,
lock_sock(sk);
switch (optname) {
+ case BT_LE_CONN_CONFIG: {
+ enum bt_le_conn_config conn_config;
+ struct hci_conn_params *params;
+ struct hci_conn *hcon;
+
+ if (!chan->conn) {
+ err = -ENOTCONN;
+ break;
+ }
+
+ hcon = chan->conn->hcon;
+ hci_dev_lock(hcon->hdev);
+
+ params = hci_conn_params_lookup(hcon->hdev,
+ &hcon->dst, hcon->dst_type);
+
+ if (params)
+ conn_config = params->conn_config;
+ else
+ conn_config = BT_LE_CONN_CONFIG_DEFAULT_LATENCY;
+
+ hci_dev_unlock(hcon->hdev);
+
+ len = min_t(unsigned int, len, sizeof(conn_config));
+ if (copy_to_user(optval, (char *) &conn_config, len))
+ err = -EFAULT;
+
+ break;
+ }
case BT_SECURITY:
if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
chan->chan_type != L2CAP_CHAN_FIXED &&
@@ -761,6 +790,86 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
lock_sock(sk);
switch (optname) {
+ case BT_LE_CONN_CONFIG: {
+ enum bt_le_conn_config conn_config;
+ struct hci_conn_params *hci_param;
+ struct hci_conn *hcon;
+ u16 min_interval = 0, max_interval = 0, latency = 0;
+
+ len = min_t(unsigned int, sizeof(conn_config), optlen);
+ if (copy_from_user((char *) &conn_config, optval, len)) {
+ err = -EFAULT;
+ break;
+ }
+
+ if (!chan->conn) {
+ err = -ENOTCONN;
+ break;
+ }
+
+ /* CUSTOM must be set only by the kernel */
+ if (conn_config >= BT_LE_CONN_CONFIG_CUSTOM_LATENCY) {
+ err = -EINVAL;
+ BT_ERR("Ignoring invalid connection configuration");
+ break;
+ }
+
+ hcon = chan->conn->hcon;
+
+ hci_dev_lock(hcon->hdev);
+
+ hci_conn_params_clear_disabled(hcon->hdev);
+
+ /* We add new param in case it doesn't exist.
+ * hci_param will be updated in hci_le_conn_update(). */
+ hci_param = hci_conn_params_add(hcon->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_param->conn_config = conn_config;
+
+ switch (conn_config) {
+ case BT_LE_CONN_CONFIG_LOW_LATENCY:
+ min_interval = 0x0006;
+ max_interval = 0x000c;
+ latency = 0x0000;
+ break;
+ case BT_LE_CONN_CONFIG_HIGH_LATENCY:
+ min_interval = 0x0038;
+ max_interval = 0x0c80;
+ latency = 0x01f3;
+ break;
+ case BT_LE_CONN_CONFIG_DEFAULT_LATENCY:
+ default:
+ /* make sure we don't have non-supported configs */
+ hci_param->conn_config =
+ BT_LE_CONN_CONFIG_DEFAULT_LATENCY;
+ min_interval = hcon->hdev->le_conn_min_interval;
+ max_interval = hcon->hdev->le_conn_max_interval;
+ latency = hcon->hdev->le_conn_latency;
+ break;
+ }
+
+ hci_dev_unlock(hcon->hdev);
+
+ l2cap_le_conn_req(chan->conn, min_interval, max_interval,
+ latency, hci_param->supervision_timeout);
+
+ /* this function also updates the hci_param value */
+ hci_le_conn_update(hcon, min_interval, max_interval, latency,
+ hci_param->supervision_timeout);
+
+ mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type, true,
+ min_interval, max_interval, latency,
+ hci_param->supervision_timeout);
+ break;
+ }
+
case BT_SECURITY:
if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
chan->chan_type != L2CAP_CHAN_FIXED &&
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 1fba2a03f8ae..0f44af559ae6 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -5540,6 +5540,7 @@ static int load_conn_param(struct sock *sk, struct hci_dev *hdev, void *data,
hci_param->conn_max_interval = max;
hci_param->conn_latency = latency;
hci_param->supervision_timeout = timeout;
+ hci_param->conn_config = BT_LE_CONN_CONFIG_CUSTOM_LATENCY;
}
hci_dev_unlock(hdev);
--
2.11.1
--
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