Bluetooth: MGMT: Add initial implementation of MGMT_OP_HCI_CMD_SYNC

This adds the initial implementation of MGMT_OP_HCI_CMD_SYNC as
documented in mgmt-api (BlueZ tree):

Send HCI command and wait for event Command
===========================================

	Command Code:		0x005B
	Controller Index:	<controller id>
	Command Parameters:	Opcode (2 Octets)
				Event (1 Octet)
				Timeout (1 Octet)
				Parameter Length (2 Octets)
				Parameter (variable)
	Return Parameters:	Response (1-variable Octets)

	This command may be used to send a HCI command and wait for an
	(optional) event.

	The HCI command is specified by the Opcode, any arbitrary is supported
	including vendor commands, but contrary to the like of
	Raw/User channel it is run as an HCI command send by the kernel
	since it uses its command synchronization thus it is possible to wait
	for a specific event as a response.

	Setting event to 0x00 will cause the command to wait for either
	HCI Command Status or HCI Command Complete.

	Timeout is specified in seconds, setting it to 0 will cause the
	default timeout to be used.

	Possible errors:	Failed
				Invalid Parameters

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/mgmt.h

@@ -878,6 +878,16 @@ struct mgmt_cp_mesh_send_cancel {
 } __packed;
 #define MGMT_MESH_SEND_CANCEL_SIZE	1
 
+#define MGMT_OP_HCI_CMD_SYNC		0x005B
+struct mgmt_cp_hci_cmd_sync {
+	__le16 opcode;
+	__u8   event;
+	__u8   timeout;
+	__le16 params_len;
+	__u8   params[];
+} __packed;
+#define MGMT_HCI_CMD_SYNC_SIZE		6
+
 #define MGMT_EV_CMD_COMPLETE		0x0001
 struct mgmt_ev_cmd_complete {
 	__le16	opcode;

net/bluetooth/mgmt.c

@@ -132,6 +132,7 @@ static const u16 mgmt_commands[] = {
 	MGMT_OP_MESH_READ_FEATURES,
 	MGMT_OP_MESH_SEND,
 	MGMT_OP_MESH_SEND_CANCEL,
+	MGMT_OP_HCI_CMD_SYNC,
 };
 
 static const u16 mgmt_events[] = {
@@ -2515,6 +2516,64 @@ static int set_le(struct sock *sk, struct hci_dev *hdev, void *data, u16 len)
 	return err;
 }
 
+static int send_hci_cmd_sync(struct hci_dev *hdev, void *data)
+{
+	struct mgmt_pending_cmd *cmd = data;
+	struct mgmt_cp_hci_cmd_sync *cp = cmd->param;
+	struct sk_buff *skb;
+
+	skb = __hci_cmd_sync_ev(hdev, le16_to_cpu(cp->opcode),
+				le16_to_cpu(cp->params_len), cp->params,
+				cp->event, cp->timeout ?
+				msecs_to_jiffies(cp->timeout * 1000) :
+				HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		mgmt_cmd_status(cmd->sk, hdev->id, MGMT_OP_HCI_CMD_SYNC,
+				mgmt_status(PTR_ERR(skb)));
+		goto done;
+	}
+
+	mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_HCI_CMD_SYNC, 0,
+			  skb->data, skb->len);
+
+	kfree_skb(skb);
+
+done:
+	mgmt_pending_free(cmd);
+
+	return 0;
+}
+
+static int mgmt_hci_cmd_sync(struct sock *sk, struct hci_dev *hdev,
+			     void *data, u16 len)
+{
+	struct mgmt_cp_hci_cmd_sync *cp = data;
+	struct mgmt_pending_cmd *cmd;
+	int err;
+
+	if (len < sizeof(*cp))
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_HCI_CMD_SYNC,
+				       MGMT_STATUS_INVALID_PARAMS);
+
+	hci_dev_lock(hdev);
+	cmd = mgmt_pending_new(sk, MGMT_OP_HCI_CMD_SYNC, hdev, data, len);
+	if (!cmd)
+		err = -ENOMEM;
+	else
+		err = hci_cmd_sync_queue(hdev, send_hci_cmd_sync, cmd, NULL);
+
+	if (err < 0) {
+		err = mgmt_cmd_status(sk, hdev->id, MGMT_OP_HCI_CMD_SYNC,
+				      MGMT_STATUS_FAILED);
+
+		if (cmd)
+			mgmt_pending_free(cmd);
+	}
+
+	hci_dev_unlock(hdev);
+	return err;
+}
+
 /* This is a helper function to test for pending mgmt commands that can
  * cause CoD or EIR HCI commands. We can only allow one such pending
  * mgmt command at a time since otherwise we cannot easily track what
@@ -9371,6 +9430,7 @@ static const struct hci_mgmt_handler mgmt_handlers[] = {
 	{ mesh_send,               MGMT_MESH_SEND_SIZE,
 						HCI_MGMT_VAR_LEN },
 	{ mesh_send_cancel,        MGMT_MESH_SEND_CANCEL_SIZE },
+	{ mgmt_hci_cmd_sync,       MGMT_HCI_CMD_SYNC_SIZE, HCI_MGMT_VAR_LEN },
 };
 
 void mgmt_index_added(struct hci_dev *hdev)