Return-Path: From: "Felipe F. Tonello" To: linux-bluetooth@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz Subject: [PATCH v5 BlueZ 3/4] Bluetooth: L2CAP: Add BT_LE_CONN_PARAM socket option Date: Thu, 13 Apr 2017 13:22:02 +0100 Message-Id: <20170413122203.4247-4-eu@felipetonello.com> In-Reply-To: <20170413122203.4247-1-eu@felipetonello.com> References: <20170413122203.4247-1-eu@felipetonello.com> List-ID: 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 --- 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