Bluetooth: mgmt: Implement Cancel Pair Device command

This patch implements the Cancel Pair Device command for mgmt. It's used
by user space to cancel an ongoing pairing attempt which was triggered
by the Pair Device command.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/mgmt.h

@@ -39,6 +39,7 @@
 #define MGMT_STATUS_INVALID_PARAMS	0x0d
 #define MGMT_STATUS_DISCONNECTED	0x0e
 #define MGMT_STATUS_NOT_POWERED		0x0f
+#define MGMT_STATUS_CANCELLED		0x10
 
 struct mgmt_hdr {
 	__le16 opcode;

net/bluetooth/mgmt.c

@@ -1594,6 +1594,54 @@ static int pair_device(struct sock *sk, u16 index, unsigned char *data, u16 len)
 	return err;
 }
 
+static int cancel_pair_device(struct sock *sk, u16 index,
+						unsigned char *data, u16 len)
+{
+	struct mgmt_addr_info *addr = (void *) data;
+	struct hci_dev *hdev;
+	struct pending_cmd *cmd;
+	struct hci_conn *conn;
+	int err;
+
+	BT_DBG("");
+
+	if (len != sizeof(*addr))
+		return cmd_status(sk, index, MGMT_OP_CANCEL_PAIR_DEVICE,
+						MGMT_STATUS_INVALID_PARAMS);
+
+	hdev = hci_dev_get(index);
+	if (!hdev)
+		return cmd_status(sk, index, MGMT_OP_CANCEL_PAIR_DEVICE,
+						MGMT_STATUS_INVALID_PARAMS);
+
+	hci_dev_lock(hdev);
+
+	cmd = mgmt_pending_find(MGMT_OP_PAIR_DEVICE, hdev);
+	if (!cmd) {
+		err = cmd_status(sk, index, MGMT_OP_CANCEL_PAIR_DEVICE,
+						MGMT_STATUS_INVALID_PARAMS);
+		goto unlock;
+	}
+
+	conn = cmd->user_data;
+
+	if (bacmp(&addr->bdaddr, &conn->dst) != 0) {
+		err = cmd_status(sk, index, MGMT_OP_CANCEL_PAIR_DEVICE,
+						MGMT_STATUS_INVALID_PARAMS);
+		goto unlock;
+	}
+
+	pairing_complete(cmd, MGMT_STATUS_CANCELLED);
+
+	err = cmd_complete(sk, index, MGMT_OP_CANCEL_PAIR_DEVICE, addr,
+								sizeof(*addr));
+unlock:
+	hci_dev_unlock(hdev);
+	hci_dev_put(hdev);
+
+	return err;
+}
+
 static int user_pairing_resp(struct sock *sk, u16 index, bdaddr_t *bdaddr,
 					u16 mgmt_op, u16 hci_op, __le32 passkey)
 {
@@ -2271,6 +2319,9 @@ int mgmt_control(struct sock *sk, struct msghdr *msg, size_t msglen)
 	case MGMT_OP_PAIR_DEVICE:
 		err = pair_device(sk, index, buf + sizeof(*hdr), len);
 		break;
+	case MGMT_OP_CANCEL_PAIR_DEVICE:
+		err = cancel_pair_device(sk, index, buf + sizeof(*hdr), len);
+		break;
 	case MGMT_OP_USER_CONFIRM_REPLY:
 		err = user_confirm_reply(sk, index, buf + sizeof(*hdr), len);
 		break;