[RFC v5] Bluetooth: MGMT: Make MGMT_OP_LOAD_CONN_PARAM update existing connection

Luiz Augusto von Dentz
2024-05-14T17:51:52Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This makes MGMT_OP_LOAD_CONN_PARAM update existing connection by
dectecting the request is just for one connection, parameters already
exists and there is a connection.

Since this is a new behavior the revision is also updated to enable
userspace to detect it.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
include/net/bluetooth/hci_sync.h | 3 ++
net/bluetooth/hci_sync.c | 18 ++++++++++++
net/bluetooth/mgmt.c | 50 ++++++++++++++++++++++++++++++--
3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/include/net/bluetooth/hci_sync.h b/include/net/bluetooth/hci_sync.h
index 6a9d063e9f47..b49057bbdf23 100644
--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -136,6 +136,7 @@ int hci_suspend_sync(struct hci_dev *hdev);
int hci_resume_sync(struct hci_dev *hdev);

struct hci_conn;
+struct hci_conn_params;

int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason);

@@ -154,3 +155,5 @@ int hci_connect_acl_sync(struct hci_dev *hdev, struct hci_conn *conn);
int hci_connect_le_sync(struct hci_dev *hdev, struct hci_conn *conn);

int hci_cancel_connect_sync(struct hci_dev *hdev, struct hci_conn *conn);
+int hci_le_conn_update_sync(struct hci_dev *hdev, struct hci_conn *conn,
+ struct hci_conn_params *params);
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 16daa79b7981..353de476a5cd 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -6711,3 +6711,21 @@ int hci_cancel_connect_sync(struct hci_dev *hdev, struct hci_conn *conn)

return -ENOENT;
}
+
+int hci_le_conn_update_sync(struct hci_dev *hdev, struct hci_conn *conn,
+ struct hci_conn_params *params)
+{
+ struct hci_cp_le_conn_update cp;
+
+ memset(&cp, 0, sizeof(cp));
+ cp.handle = cpu_to_le16(conn->handle);
+ cp.conn_interval_min = cpu_to_le16(params->conn_min_interval);
+ cp.conn_interval_max = cpu_to_le16(params->conn_max_interval);
+ cp.conn_latency = cpu_to_le16(params->conn_latency);
+ cp.supervision_timeout = cpu_to_le16(params->supervision_timeout);
+ cp.min_ce_len = cpu_to_le16(0x0000);
+ cp.max_ce_len = cpu_to_le16(0x0000);
+
+ return __hci_cmd_sync_status(hdev, HCI_OP_LE_CONN_UPDATE,
+ sizeof(cp), &cp, HCI_CMD_TIMEOUT);
+}
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 80f220b7e19d..20eca8a9c681 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -42,7 +42,7 @@
#include "aosp.h"

#define MGMT_VERSION 1
-#define MGMT_REVISION 22
+#define MGMT_REVISION 23

static const u16 mgmt_commands[] = {
MGMT_OP_READ_INDEX_LIST,
@@ -7813,6 +7813,18 @@ static int remove_device(struct sock *sk, struct hci_dev *hdev,
return err;
}

+static int conn_update_sync(struct hci_dev *hdev, void *data)
+{
+ struct hci_conn_params *params = data;
+ struct hci_conn *conn;
+
+ conn = hci_conn_hash_lookup_le(hdev, &params->addr, params->addr_type);
+ if (!conn)
+ return -ECANCELED;
+
+ return hci_le_conn_update_sync(hdev, conn, params);
+}
+
static int load_conn_param(struct sock *sk, struct hci_dev *hdev, void *data,
u16 len)
{
@@ -7846,13 +7858,15 @@ static int load_conn_param(struct sock *sk, struct hci_dev *hdev, void *data,

hci_dev_lock(hdev);

- hci_conn_params_clear_disabled(hdev);
+ if (param_count > 1)
+ hci_conn_params_clear_disabled(hdev);

for (i = 0; i < param_count; i++) {
struct mgmt_conn_param *param = &cp->params[i];
struct hci_conn_params *hci_param;
u16 min, max, latency, timeout;
u8 addr_type;
+ bool update;

bt_dev_dbg(hdev, "Adding %pMR (type %u)", &param->addr.bdaddr,
param->addr.type);
@@ -7879,6 +7893,19 @@ static int load_conn_param(struct sock *sk, struct hci_dev *hdev, void *data,
continue;
}

+ /* Detect when the loading is for an existing parameter then
+ * attempt to trigger the connection update procedure.
+ */
+ if (!i && param_count == 1) {
+ hci_param = hci_conn_params_lookup(hdev,
+ &param->addr.bdaddr,
+ addr_type);
+ if (hci_param)
+ update = true;
+ else
+ hci_conn_params_clear_disabled(hdev);
+ }
+
hci_param = hci_conn_params_add(hdev, &param->addr.bdaddr,
addr_type);
if (!hci_param) {
@@ -7890,6 +7917,25 @@ 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;
+
+ /* Check if we need to trigger a connection update */
+ if (update) {
+ struct hci_conn *conn;
+
+ /* Lookup for existing connection as central and check
+ * if parameters match and if they don't then trigger
+ * a connection update.
+ */
+ conn = hci_conn_hash_lookup_le(hdev, &hci_param->addr,
+ addr_type);
+ if (conn && conn->role == HCI_ROLE_MASTER &&
+ (conn->le_conn_min_interval != min ||
+ conn->le_conn_max_interval != max ||
+ conn->le_conn_latency != latency ||
+ conn->le_supv_timeout != timeout))
+ hci_cmd_sync_queue(hdev, conn_update_sync,
+ hci_param, NULL);
+ }
}

hci_dev_unlock(hdev);
--
2.45.0