diff --git a/backend/usb_manager.cxx b/backend/usb_manager.cxx
new file mode 100644
index 0000000..2604e10
--- /dev/null
+++ b/backend/usb_manager.cxx
@@ -0,0 +1,663 @@
+/*
+ * Copyright (c) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * OH USB interface code for CUPS.
+ */
+
+/*
+ * Include necessary headers.
+ */
+
+#include "usb_manager.h"
+#include "usb_srv_client.h"
+#include "v1_0/iusb_interface.h"
+
+#include <map>
+#include <regex>
+#include <string>
+#include <thread>
+#include <securec.h>
+
+using namespace std;
+using namespace OHOS;
+using namespace OHOS::USB;
+
+#define SAFE_DELETE(ptr)    \
+    if ((ptr) != nullptr) { \
+        delete (ptr);       \
+        (ptr) = nullptr;    \
+    }
+
+#define SAFE_DELETE_ARRAY(ptr) \
+    if ((ptr) != nullptr) {    \
+        delete[] (ptr);        \
+        (ptr) = nullptr;       \
+    }
+
+int32_t BulkTransferWriteData(
+    USBDevicePipe &usbDevicePipe, USBEndpoint &endpoint, const std::string &sendDataStr, int32_t timeout);
+int32_t ParseDeviceDescriptor(UsbDevice &usbDevice, ohusb_device_descriptor *devDesc);
+int32_t ParseConfigDescriptor(USBConfig &usbConfig, ohusb_config_descriptor *confDesc);
+int32_t ParseInterface(std::vector<UsbInterface> &usbIfaces, ohusb_interface *usbInterface, int32_t ifaceIndex);
+int32_t ParseInterfaceDescriptor(UsbInterface &usbInterface, ohusb_interface_descriptor *ifaceDesc);
+int32_t ParseEndpointDescriptor(USBEndpoint &usbEndpoint, ohusb_endpoint_descriptor *epDesc);
+void ReleaseDeviceDescriptor(ohusb_device_descriptor *devDesc);
+void ReleaseConfigDescriptor(ohusb_config_descriptor *confDesc);
+void ReleaseInterface(ohusb_interface *iface);
+void ReleaseInterfaceDescriptor(ohusb_interface_descriptor *ifaceDesc);
+void DumpDeviceDescriptor(ohusb_device_descriptor *devdesc);
+void DumpConfigDescriptor(ohusb_config_descriptor *confDesc);
+void DumpInterfaceDescriptor(ohusb_interface_descriptor *ifaceDesc);
+void DumpEndpointDescriptor(ohusb_endpoint_descriptor *eptDesc);
+char *CopyString(const std::string &source);
+
+int32_t OH_GetDevices(ohusb_device_descriptor** list, ssize_t *numdevs)
+{
+    fprintf(stderr, "DEBUG: OH_GetDevices enter\n");
+    vector<UsbDevice> devlist;
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    auto getDevRet = usbSrvClient.GetDevices(devlist);
+    fprintf(stderr, "DEBUG: OH_GetDevices getDevRet = %d\n", getDevRet);
+    if (getDevRet != OHOS::ERR_OK) {
+        return OHUSB_ERROR_IO;
+    }
+    if (devlist.empty()) {
+        return OHUSB_SUCCESS;
+    }
+    ssize_t devCount = devlist.size();
+    *numdevs = 0;
+    fprintf(stderr, "DEBUG: OH_GetDevices device nums = %zd\n", devCount);
+
+    *list = (ohusb_device_descriptor *)calloc((size_t)devCount, sizeof(ohusb_device_descriptor));
+    if (*list == nullptr) {
+        fprintf(stderr, "DEBUG: OH_GetDevices list is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    for (ssize_t i = 0; i < devCount; i++) {
+        fprintf(stderr, "DEBUG: OH_GetDevices devlist[%zd] devAddr = %d, busNum = %d\n",
+            i, devlist[i].GetDevAddr(), devlist[i].GetBusNum());
+        if (ParseDeviceDescriptor(devlist[i], *list + i) != OHUSB_SUCCESS) {
+            return OHUSB_ERROR_IO;
+        }
+        (*numdevs)++;
+    }
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_OpenDevice(ohusb_device_descriptor *devDesc, ohusb_pipe **pipe)
+{
+    fprintf(stderr, "DEBUG: OH_OpenDevice enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    UsbDevice usbDevice;
+    usbDevice.SetBusNum(devDesc->busNum);
+    usbDevice.SetDevAddr(devDesc->devAddr);
+    USBDevicePipe usbDevicePipe;
+    auto openDevRet = usbSrvClient.OpenDevice(usbDevice, usbDevicePipe);
+    fprintf(stderr, "DEBUG: OH_OpenDevice getDevRet = %d\n", openDevRet);
+    if (openDevRet != OHOS::ERR_OK) {
+        return OHUSB_ERROR_IO;
+    }
+    *pipe = (ohusb_pipe *)calloc(1, sizeof(ohusb_pipe));
+    if (*pipe == nullptr) {
+        fprintf(stderr, "DEBUG: OH_OpenDevice pipe is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    (*pipe)->busNum = usbDevicePipe.GetBusNum();
+    (*pipe)->devAddr = usbDevicePipe.GetDevAddr();
+    fprintf(stderr, "DEBUG: OH_OpenDevice busNum=%d, devAddr=%d\n", (*pipe)->busNum, (*pipe)->devAddr);
+    fprintf(stderr, "DEBUG: OH_OpenDevice out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_CloseDevice(ohusb_pipe *pipe)
+{
+    fprintf(stderr, "DEBUG: OH_CloseDevice enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    int32_t ret = usbSrvClient.Close(usbDevicePipe);
+    if (ret != ERR_OK) {
+        fprintf(stderr, "DEBUG: OH_CloseDevice fail with ret = %d\n", ret);
+        return OHUSB_ERROR_BUSY;
+    }
+    fprintf(stderr, "DEBUG: OH_CloseDevice out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_ClaimInterface(ohusb_pipe *pipe, int interfaceId, bool force)
+{
+    fprintf(stderr, "DEBUG: OH_ClaimInterface enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    UsbInterface usbInterface;
+    usbInterface.SetId(interfaceId);
+    int32_t ret = usbSrvClient.ClaimInterface(usbDevicePipe, usbInterface, force);
+    if (ret != ERR_OK) {
+        fprintf(stderr, "DEBUG: OH_ClaimInterface fail with ret = %d\n", ret);
+        return OHUSB_ERROR_BUSY;
+    }
+    fprintf(stderr, "DEBUG: OH_ClaimInterface out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_ReleaseInterface(ohusb_pipe *pipe, int interfaceId)
+{
+    fprintf(stderr, "DEBUG: OH_ReleaseInterface enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    UsbInterface usbInterface;
+    usbInterface.SetId(interfaceId);
+    int32_t ret = usbSrvClient.ReleaseInterface(usbDevicePipe, usbInterface);
+    if (ret != ERR_OK) {
+        fprintf(stderr, "DEBUG: OH_ReleaseInterface fail with ret = %d\n", ret);
+        return OHUSB_ERROR_BUSY;
+    }
+    fprintf(stderr, "DEBUG: OH_ReleaseInterface out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_BulkTransferRead(
+    ohusb_pipe *pipe, ohusb_transfer_pipe *tpipe, unsigned char *data, int length, int *transferred)
+{
+    fprintf(stderr, "DEBUG: OH_BulkTransferRead enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    USBEndpoint endpoint;
+    endpoint.SetInterfaceId(tpipe->bInterfaceId);
+    endpoint.SetAddr(tpipe->bEndpointAddress);
+    std::vector<uint8_t> readTempBuffer;
+    size_t readSize = 0;
+    int32_t ret = usbSrvClient.BulkTransfer(usbDevicePipe, endpoint, readTempBuffer, OHUSB_BULKTRANSFER_READ_TIMEOUT);
+    fprintf(stderr, "DEBUG: OH_BulkTransferRead ret = %d\n", ret);
+    if (ret == HDF_DEV_ERR_NO_DEVICE) {
+        fprintf(stderr, "DEBUG: OH_BulkTransferRead HDF_DEV_ERR_NO_DEVICE, The device module has no device\n");
+        return OHUSB_ERROR_NO_DEVICE;
+    }
+    readSize = readTempBuffer.size();
+    if (ret == OHUSB_SUCCESS) {
+        std::copy(readTempBuffer.begin(), readTempBuffer.begin() + readSize, data);
+        fprintf(stderr, "DEBUG: OH_BulkTransferRead readSize = %zu\n", readSize);
+        *transferred = readSize;
+        return OHUSB_SUCCESS;
+    }
+
+    fprintf(stderr, "DEBUG: OH_BulkTransferRead read data time out\n");
+    return OHUSB_ERROR_TIMEOUT;
+}
+
+int32_t OH_BulkTransferWrite(
+    ohusb_pipe *pipe, ohusb_transfer_pipe *tpipe, unsigned char *data, int length, int *transferred, int32_t timeout)
+{
+    fprintf(stderr, "DEBUG: OH_BulkTransferRead enter\n");
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    USBEndpoint endpoint;
+    endpoint.SetInterfaceId(tpipe->bInterfaceId);
+    endpoint.SetAddr(tpipe->bEndpointAddress);
+    int32_t ret = 0;
+    int leftDataLen = length;
+    while (leftDataLen > 0) {
+        fprintf(stderr, "DEBUG: OH_BulkTransferWrite leftDataLen waiting for transfer = %d\n", leftDataLen);
+        size_t len = leftDataLen > OHUSB_ENDPOINT_MAX_LENGTH ? OHUSB_ENDPOINT_MAX_LENGTH : leftDataLen;
+        std::string sendDataStr(reinterpret_cast<char *>(data), len);
+        ret = BulkTransferWriteData(usbDevicePipe, endpoint, sendDataStr, timeout);
+        if (ret != 0) {
+            return ret;
+        }
+        fprintf(stderr, "DEBUG: OH_BulkTransferWrite transferred data len = %zu\n", len);
+        leftDataLen -= len;
+        data += len;
+    }
+    *transferred = length - leftDataLen;
+    fprintf(stderr, "DEBUG: transferred data len = %d\n", *transferred);
+    fprintf(stderr, "DEBUG: OH_BulkTransferWrite out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t BulkTransferWriteData(
+    USBDevicePipe &usbDevicePipe, USBEndpoint &endpoint, const std::string &sendDataStr, int32_t timeout)
+{
+    std::vector<uint8_t> vectorRequestBuffer;
+    vectorRequestBuffer.assign(sendDataStr.begin(), sendDataStr.end());
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    uint32_t retryNum = 0;
+    int32_t ret = 0;
+    do {
+        fprintf(stderr, "DEBUG: BulkTransferWriteData write data retryCout: %d\n", retryNum);
+        ret = usbSrvClient.BulkTransfer(usbDevicePipe, endpoint, vectorRequestBuffer, timeout);
+        fprintf(stderr, "DEBUG: BulkTransferWrite ret: %d\n", ret);
+        if (ret == HDF_DEV_ERR_NO_DEVICE) {
+            fprintf(stderr, "DEBUG: BulkTransferWriteData no device\n");
+            return OHUSB_ERROR_NO_DEVICE;
+        }
+        if (ret == OHUSB_ERROR_TIMEOUT) {
+            std::this_thread::sleep_for(std::chrono::milliseconds(OHUSB_BULKTRANSFER_WRITE_SLEEP));
+            retryNum++;
+        }
+    } while (ret == OHUSB_ERROR_TIMEOUT && retryNum < OHUSB_WRITE_RETRY_MAX_TIMES);
+    if (ret != 0) {
+        fprintf(stderr, "DEBUG: Write data fail\n");
+        return ret;
+    }
+    return ret;
+}
+
+int32_t OH_ControlTransferRead(
+    ohusb_pipe *pipe, ohusb_control_transfer_parameter *ctrlParam, unsigned char *data, uint16_t length)
+{
+    fprintf(stderr, "DEBUG: OH_ControlTransferRead enter\n");
+    if (pipe == nullptr || ctrlParam == nullptr) {
+        fprintf(stderr, "DEBUG: pipe or ctrlParam is nullptr\n");
+        return OHUSB_ERROR_IO;
+    }
+    fprintf(stderr, "DEBUG: OH_ControlTransferRead busNum=%d, devAddr=%d\n", pipe->busNum, pipe->devAddr);
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    int32_t requestType = ctrlParam->requestType;
+    int32_t request = ctrlParam->request;
+    int32_t value = ctrlParam->value;
+    int32_t index = ctrlParam->index;
+    int32_t timeOut = ctrlParam->timeout;
+    const HDI::Usb::V1_0::UsbCtrlTransfer tctrl = {requestType, request, value, index, timeOut};
+    std::vector<uint8_t> bufferData(length, 0);
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    uint32_t retryNum = 0;
+    int32_t ret = OHUSB_SUCCESS;
+    do {
+        ret = usbSrvClient.ControlTransfer(usbDevicePipe, tctrl, bufferData);
+        fprintf(stderr, "DEBUG: OH_ControlTransferRead ret = %d\n", ret);
+        if (ret == OHUSB_ERROR_TIMEOUT) {
+            std::this_thread::sleep_for(std::chrono::milliseconds(OHUSB_CONTROLTRANSFER_READ_SLEEP));
+            retryNum++;
+            fprintf(stderr, "DEBUG: OH_ControlTransferRead retryCount: %d\n", retryNum);
+        }
+    } while (ret == OHUSB_ERROR_TIMEOUT && retryNum < OHUSB_CONTROLTRANSFER_READ_RETRY_MAX_TIMES);
+    if (ret != 0) {
+        fprintf(stderr, "DEBUG: OH_ControlTransferRead fail\n");
+        return OHUSB_ERROR_IO;
+    }
+    fprintf(stderr, "DEBUG: OH_ControlTransferRead bufferData size = %zu\n", bufferData.size());
+
+    if ((value >> 8) == OHUSB_DT_STRING) {
+        int bufferLen = bufferData.size();
+        uint16_t *wbuf = new (std::nothrow) uint16_t[bufferLen + 1]();
+        if (wbuf == nullptr) {
+            fprintf(stderr, "DEBUG: OH_ControlTransferRead wbuf is nullptr.\n");
+            return OHUSB_ERROR_NO_MEM;
+        }
+        for (uint32_t i = 0; i < bufferLen - 2; ++i) {
+            wbuf[i] = bufferData[i + 2];
+        }
+        std::wstring wstr(reinterpret_cast<wchar_t *>(wbuf), (bufferLen - 2) / 2);
+        std::string buffer(wstr.begin(), wstr.end());
+        fprintf(stderr, "DEBUG: OH_ControlTransferRead buffer = %s\n", buffer.c_str());
+        if (memcpy_s(data, length, buffer.c_str(), buffer.length()) != 0) {
+            fprintf(stderr, "DEBUG: OH_ControlTransferRead memcpy_s fail.\n");
+            return OHUSB_ERROR_NO_MEM;
+        }
+    } else if (memcpy_s(data, length, bufferData.data(), bufferData.size()) != 0) {
+        fprintf(stderr, "DEBUG: OH_ControlTransferRead memcpy_s fail.\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+
+    fprintf(stderr, "DEBUG: OH_ControlTransferRead out\n");
+    return bufferData.size();
+}
+
+int32_t OH_ControlTransferWrite(
+    ohusb_pipe *pipe, ohusb_control_transfer_parameter *ctrlParam, unsigned char *data, uint16_t length)
+{
+    fprintf(stderr, "DEBUG: OH_ControlTransferWrite enter\n");
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    int32_t requestType = ctrlParam->requestType;
+    int32_t request = ctrlParam->request;
+    int32_t value = ctrlParam->value;
+    int32_t index = ctrlParam->index;
+    int32_t timeOut = ctrlParam->timeout;
+    const HDI::Usb::V1_0::UsbCtrlTransfer tctrl = {requestType, request, value, index, timeOut};
+    std::vector<uint8_t> bufferData(length, 0);
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    int32_t ret = usbSrvClient.ControlTransfer(usbDevicePipe, tctrl, bufferData);
+    if (ret != 0) {
+        fprintf(stderr, "DEBUG: OH_ControlTransferWrite fail with ret = %d\n", ret);
+        return OHUSB_ERROR_IO;
+    }
+
+    fprintf(stderr, "DEBUG: OH_ControlTransferRead out\n");
+    return length;
+}
+
+int32_t OH_GetStringDescriptor(ohusb_pipe *pipe, int descId, unsigned char *descriptor, int length)
+{
+    fprintf(stderr, "DEBUG: OH_GetStringDescriptor enter\n");
+    if (descId == 0) {
+		return OHUSB_ERROR_INVALID_PARAM;
+    }
+    ohusb_control_transfer_parameter ctrlParam = {
+        OHUSB_ENDPOINT_IN,
+        OHUSB_REQUEST_GET_DESCRIPTOR,
+        (uint16_t)((OHUSB_DT_STRING << 8) | descId),
+        OHUSB_LANGUAGE_ID_ENGLISH,
+        OHUSB_GET_STRING_DESCRIPTOR_TIMEOUT
+    };
+    auto ret = OH_ControlTransferRead(pipe, &ctrlParam, descriptor, length);
+    if (ret < 0) {
+        fprintf(stderr, "DEBUG: OH_GetStringDescriptor OH_ControlTransferRead failed\n");
+        return ret;
+    }
+
+    fprintf(stderr, "DEBUG: OH_GetStringDescriptor out\n");
+    return ret;
+}
+
+int32_t ParseDeviceDescriptor(UsbDevice &usbDevice, ohusb_device_descriptor *devDesc)
+{
+    fprintf(stderr, "DEBUG: ParseDeviceDescriptor enter\n");
+    if (devDesc == nullptr) {
+        fprintf(stderr, "DEBUG: ParseDeviceDescriptor devDesc is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+
+    devDesc->devAddr = usbDevice.GetDevAddr();
+    devDesc->busNum = usbDevice.GetBusNum();
+    devDesc->bcdUSB = usbDevice.GetbcdUSB();
+    devDesc->bDeviceClass = usbDevice.GetClass();
+    devDesc->bDeviceSubClass = usbDevice.GetSubclass();
+    devDesc->bDeviceProtocol = usbDevice.GetProtocol();
+    devDesc->bMaxPacketSize0 = usbDevice.GetbMaxPacketSize0();
+    devDesc->idVendor = usbDevice.GetVendorId();
+    devDesc->idProduct = usbDevice.GetProductId();
+    devDesc->iManufacturer = usbDevice.GetiManufacturer();
+    devDesc->iProduct = usbDevice.GetiProduct();
+    devDesc->iSerialNumber = usbDevice.GetiSerialNumber();
+    devDesc->bNumConfigurations = 0;
+    ohusb_config_descriptor *config =
+        (ohusb_config_descriptor *)calloc((size_t)usbDevice.GetConfigCount(), sizeof(ohusb_config_descriptor));
+    if (config == nullptr) {
+        fprintf(stderr, "DEBUG: ParseDeviceDescriptor config is null.\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    devDesc->config = config;
+
+    for (int i = 0; i < usbDevice.GetConfigCount(); i++) {
+        USBConfig usbConfig;
+        usbDevice.GetConfig(i, usbConfig);
+        if (ParseConfigDescriptor(usbConfig, config + i) != OHUSB_SUCCESS) {
+            return OHUSB_ERROR_IO;
+        }
+        (devDesc->bNumConfigurations)++;
+    }
+    DumpDeviceDescriptor(devDesc);
+    fprintf(stderr, "DEBUG: ParseDeviceDescriptor out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t ParseConfigDescriptor(USBConfig &usbConfig, ohusb_config_descriptor *confDesc)
+{
+    fprintf(stderr, "DEBUG: ParseConfigDescriptor enter\n");
+    if (confDesc == nullptr) {
+        fprintf(stderr, "DEBUG: ParseConfigDescriptor confDesc is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    confDesc->iConfiguration = usbConfig.GetId();
+    confDesc->bmAttributes = usbConfig.GetAttributes();
+    confDesc->MaxPower = usbConfig.GetMaxPower();
+
+    std::vector<UsbInterface> usbIfaces = usbConfig.GetInterfaces();
+    int32_t ifaceCount = usbIfaces.size() > 0 ? usbIfaces[usbIfaces.size() - 1].GetId() + 1 : 0;
+
+    confDesc->bNumInterfaces = 0;
+    ohusb_interface *usbInterface =
+        (ohusb_interface *)calloc((size_t)ifaceCount, sizeof(ohusb_interface));
+    if (usbInterface == nullptr) {
+        fprintf(stderr, "DEBUG: ParseConfigDescriptor usbInterface is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    confDesc->interface = usbInterface;
+    for (int32_t ifaceIndex = 0; ifaceIndex < ifaceCount; ifaceIndex++) {
+        if (ParseInterface(usbIfaces, usbInterface + ifaceIndex, ifaceIndex) != OHUSB_SUCCESS) {
+            return OHUSB_ERROR_IO;
+        }
+        (confDesc->bNumInterfaces)++;
+    }
+    DumpConfigDescriptor(confDesc);
+    fprintf(stderr, "DEBUG: ParseConfigDescriptor out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t ParseInterface(std::vector<UsbInterface> &usbIfaces, ohusb_interface *usbInterface, int32_t ifaceIndex)
+{
+    fprintf(stderr, "DEBUG: ParseInterface ifaceIndex=%d\n", ifaceIndex);
+    for (int32_t usbIfacesIndex = 0; usbIfacesIndex < usbIfaces.size(); usbIfacesIndex++) {
+        if (usbIfaces[usbIfacesIndex].GetId() == ifaceIndex) {
+            ohusb_interface_descriptor *altsetting;
+            altsetting = (ohusb_interface_descriptor *)
+                realloc(usbInterface->altsetting, sizeof(*altsetting) * (size_t)(usbInterface->num_altsetting +1));
+            if (altsetting == nullptr) {
+                fprintf(stderr, "DEBUG: ParseInterface altsetting is nullptr\n");
+                return OHUSB_ERROR_NO_MEM;
+            }
+            usbInterface->altsetting = altsetting;
+            if (ParseInterfaceDescriptor(usbIfaces[usbIfacesIndex], altsetting + (usbInterface->num_altsetting))
+                != OHUSB_SUCCESS) {
+                return OHUSB_ERROR_IO;
+            }
+            usbInterface->num_altsetting++;
+        }
+    }
+    fprintf(stderr, "DEBUG: ParseInterface num_altsetting=%d\n", usbInterface->num_altsetting);
+    return OHUSB_SUCCESS;
+}
+
+int32_t ParseInterfaceDescriptor(UsbInterface &usbInterface, ohusb_interface_descriptor *ifaceDesc)
+{
+    fprintf(stderr, "DEBUG: ParseInterfaceDescriptor enter\n");
+    if (ifaceDesc == nullptr) {
+        fprintf(stderr, "DEBUG: ParseInterfaceDescriptor ifaceDesc is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    ifaceDesc->bInterfaceNumber = usbInterface.GetId();
+    ifaceDesc->bAlternateSetting = usbInterface.GetAlternateSetting();
+    ifaceDesc->bInterfaceClass = usbInterface.GetClass();
+    ifaceDesc->bInterfaceSubClass = usbInterface.GetSubClass();
+    ifaceDesc->bInterfaceProtocol = usbInterface.GetProtocol();
+    ifaceDesc->bNumEndpoints = 0;
+    fprintf(stderr, "DEBUG: ParseInterfaceDescriptor class=%x, subclass=%x, protocol=%x.\n",
+        usbInterface.GetClass(), usbInterface.GetSubClass(), usbInterface.GetProtocol());
+	ohusb_endpoint_descriptor *endpoint;
+    endpoint = (ohusb_endpoint_descriptor *)
+        calloc((size_t)usbInterface.GetEndpointCount(), sizeof(ohusb_endpoint_descriptor));
+    if (endpoint == nullptr) {
+        fprintf(stderr, "DEBUG: endpoint is null.\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    ifaceDesc->endpoint = endpoint;
+    std::vector<USBEndpoint> endpoints = usbInterface.GetEndpoints();
+    for (int i = 0; i < usbInterface.GetEndpointCount(); i++) {
+        if (ParseEndpointDescriptor(endpoints[i], endpoint + i) != OHUSB_SUCCESS) {
+            return OHUSB_ERROR_IO;
+        }
+        (ifaceDesc->bNumEndpoints)++;
+    }
+    DumpInterfaceDescriptor(ifaceDesc);
+    fprintf(stderr, "DEBUG: ParseInterfaceDescriptor out\n");
+	return OHUSB_SUCCESS;
+}
+
+int32_t ParseEndpointDescriptor(USBEndpoint &usbEndpoint, ohusb_endpoint_descriptor *epDesc)
+{
+    fprintf(stderr, "DEBUG: ParseEndpointDescriptor enter\n");
+    if (epDesc == nullptr) {
+        fprintf(stderr, "DEBUG: ParseEndpointDescriptor epDesc is nullptr\n");
+        return OHUSB_ERROR_NO_MEM;
+    }
+    epDesc->bDescriptorType = usbEndpoint.GetType();
+    epDesc->bEndpointAddress = usbEndpoint.GetAddress();
+    epDesc->bmAttributes = usbEndpoint.GetAttributes();
+    epDesc->wMaxPacketSize = usbEndpoint.GetMaxPacketSize();
+    epDesc->bInterval = usbEndpoint.GetInterval();
+    epDesc->bInterfaceId = usbEndpoint.GetInterfaceId();
+    epDesc->direction = usbEndpoint.GetDirection();
+    DumpEndpointDescriptor(epDesc);
+    fprintf(stderr, "DEBUG: ParseEndpointDescriptor out\n");
+	return OHUSB_SUCCESS;
+}
+
+int32_t OH_SetConfiguration(ohusb_pipe *pipe, int configIndex)
+{
+    fprintf(stderr, "DEBUG: OH_SetConfiguration enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    USBConfig usbConfig;
+    usbConfig.SetId(configIndex);
+    int32_t ret = usbSrvClient.SetConfiguration(usbDevicePipe, usbConfig);
+    if (ret != ERR_OK) {
+        fprintf(stderr, "DEBUG: OH_SetConfiguration fail with ret = %d\n", ret);
+        return OHUSB_ERROR_BUSY;
+    }
+    fprintf(stderr, "DEBUG: OH_SetConfiguration out\n");
+    return OHUSB_SUCCESS;
+}
+
+int32_t OH_SetInterface(ohusb_pipe *pipe, int interfaceId, int altIndex)
+{
+    fprintf(stderr, "DEBUG: OH_SetInterface enter\n");
+    auto &usbSrvClient = OHOS::USB::UsbSrvClient::GetInstance();
+    USBDevicePipe usbDevicePipe = {pipe->busNum, pipe->devAddr};
+    UsbInterface usbInterface;
+    usbInterface.SetId(interfaceId);
+    usbInterface.SetAlternateSetting(altIndex);
+    int32_t ret = usbSrvClient.SetInterface(usbDevicePipe, usbInterface);
+    if (ret != ERR_OK) {
+        fprintf(stderr, "DEBUG: OH_SetInterface fail with ret = %d\n", ret);
+        return OHUSB_ERROR_BUSY;
+    }
+    fprintf(stderr, "DEBUG: OH_SetInterface out\n");
+    return OHUSB_SUCCESS;
+}
+
+void ReleaseInterfaceDescriptor(ohusb_interface_descriptor *ifaceDesc)
+{
+    if (ifaceDesc != nullptr) {
+        SAFE_DELETE_ARRAY(ifaceDesc->endpoint);
+        ifaceDesc->bNumEndpoints = 0;
+        SAFE_DELETE_ARRAY(ifaceDesc);
+    }
+}
+
+void ReleaseInterface(ohusb_interface *iface)
+{
+    if (iface != nullptr) {
+        for (uint8_t i = 0; i < iface->num_altsetting; i++) {
+            ReleaseInterfaceDescriptor((iface->altsetting) + i);
+        }
+        iface->num_altsetting = 0;
+        SAFE_DELETE_ARRAY(iface);
+    }
+}
+
+void ReleaseConfigDescriptor(ohusb_config_descriptor *confDesc)
+{
+    if (confDesc != nullptr) {
+        for (uint8_t i = 0; i < confDesc->bNumInterfaces; i++) {
+            ReleaseInterface((confDesc->interface) + i);
+        }
+        confDesc->bNumInterfaces = 0;
+        SAFE_DELETE_ARRAY(confDesc);
+    }
+}
+
+void ReleaseDeviceDescriptor(ohusb_device_descriptor *devDesc)
+{
+    if (devDesc != nullptr) {
+        for (uint8_t i = 0; i < devDesc->bNumConfigurations; i++) {
+            ReleaseConfigDescriptor((devDesc->config) + i);
+        }
+        devDesc->bNumConfigurations = 0;
+        SAFE_DELETE_ARRAY(devDesc);
+    }
+}
+
+void DumpDeviceDescriptor(ohusb_device_descriptor *devDesc)
+{
+    fprintf(stderr, "DEBUG: ------------------begin DeviceDescriptor------------------\n");
+    fprintf(stderr, "DEBUG: busNum = %x\n", devDesc->busNum);
+    fprintf(stderr, "DEBUG: devAddr = %x\n", devDesc->devAddr);
+    fprintf(stderr, "DEBUG: bcdUSB = %d\n", devDesc->bcdUSB);
+    fprintf(stderr, "DEBUG: bDeviceClass = %x\n", devDesc->bDeviceClass);
+    fprintf(stderr, "DEBUG: bDeviceSubClass = %x\n", devDesc->bDeviceSubClass);
+    fprintf(stderr, "DEBUG: bDeviceProtocol = %x\n", devDesc->bDeviceProtocol);
+    fprintf(stderr, "DEBUG: bMaxPacketSize0 = %x\n", devDesc->bMaxPacketSize0);
+    fprintf(stderr, "DEBUG: idVendor = %d\n", devDesc->idVendor);
+    fprintf(stderr, "DEBUG: idProduct = %d\n", devDesc->idProduct);
+    fprintf(stderr, "DEBUG: bcdDevice = %d\n", devDesc->bcdDevice);
+    fprintf(stderr, "DEBUG: iManufacturer = %x\n", devDesc->iManufacturer);
+    fprintf(stderr, "DEBUG: iProduct = %x\n", devDesc->iProduct);
+    fprintf(stderr, "DEBUG: iSerialNumber = %x\n", devDesc->iSerialNumber);
+    fprintf(stderr, "DEBUG: bNumConfigurations = %x\n", devDesc->bNumConfigurations);
+    fprintf(stderr, "DEBUG: ------------------end DeviceDescriptor------------------\n");
+    return;
+}
+
+void DumpConfigDescriptor(ohusb_config_descriptor *confDesc)
+{
+    fprintf(stderr, "DEBUG: ------------------begin ConfigDescriptor------------------\n");
+    fprintf(stderr, "DEBUG: iConfiguration = %x\n", confDesc->iConfiguration);
+    fprintf(stderr, "DEBUG: bmAttributes = %x\n", confDesc->bmAttributes);
+    fprintf(stderr, "DEBUG: MaxPower = %x\n", confDesc->MaxPower);
+    fprintf(stderr, "DEBUG: bNumInterfaces = %x\n", confDesc->bNumInterfaces);
+    fprintf(stderr, "DEBUG: ------------------end ConfigDescriptor------------------\n");
+    return;
+}
+
+void DumpInterfaceDescriptor(ohusb_interface_descriptor *ifaceDesc)
+{
+    fprintf(stderr, "DEBUG: ------------------begin InterfaceDescriptor------------------\n");
+    fprintf(stderr, "DEBUG: bInterfaceNumber = %x\n", ifaceDesc->bInterfaceNumber);
+    fprintf(stderr, "DEBUG: bAlternateSetting = %x\n", ifaceDesc->bAlternateSetting);
+    fprintf(stderr, "DEBUG: bInterfaceClass = %x\n", ifaceDesc->bInterfaceClass);
+    fprintf(stderr, "DEBUG: bInterfaceSubClass = %x\n", ifaceDesc->bInterfaceSubClass);
+    fprintf(stderr, "DEBUG: bInterfaceProtocol = %x\n", ifaceDesc->bInterfaceProtocol);
+    fprintf(stderr, "DEBUG: bNumEndpoints = %x\n", ifaceDesc->bNumEndpoints);
+    fprintf(stderr, "DEBUG: ------------------end InterfaceDescriptor------------------\n");
+    return;
+}
+
+void DumpEndpointDescriptor(ohusb_endpoint_descriptor *eptDesc)
+{
+    fprintf(stderr, "DEBUG: ------------------begin EndpointDescriptor------------------\n");
+    fprintf(stderr, "DEBUG: bDescriptorType = %x\n", eptDesc->bDescriptorType);
+    fprintf(stderr, "DEBUG: bEndpointAddress = %x\n", eptDesc->bEndpointAddress);
+    fprintf(stderr, "DEBUG: bmAttributes = %x\n", eptDesc->bmAttributes);
+    fprintf(stderr, "DEBUG: wMaxPacketSize = %d\n", eptDesc->wMaxPacketSize);
+    fprintf(stderr, "DEBUG: bInterval = %x\n", eptDesc->bInterval);
+    fprintf(stderr, "DEBUG: bInterfaceId = %x\n", eptDesc->bInterfaceId);
+    fprintf(stderr, "DEBUG: direction = %d\n", eptDesc->direction);
+    fprintf(stderr, "DEBUG: ------------------end EndpointDescriptor------------------\n");
+    return;
+}
+
+char *CopyString(const std::string &source)
+{
+    auto len = source.length();
+    char *dest = new (std::nothrow) char[len + 1];
+    if (dest == nullptr) {
+        fprintf(stderr, "DEBUG: CopyString allocate failed\n");
+        return nullptr;
+    }
+    if (strcpy_s(dest, len + 1, source.c_str()) != 0) {
+        fprintf(stderr, "DEBUG: CopyString strcpy_s failed\n");
+    }
+    dest[len] = '\0';
+    return dest;
+}
\ No newline at end of file
diff --git a/backend/usb_manager.h b/backend/usb_manager.h
new file mode 100644
index 0000000..30ced79
--- /dev/null
+++ b/backend/usb_manager.h
@@ -0,0 +1,465 @@
+/*
+ * Copyright (c) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef USB_MANAGER_H
+#define USB_MANAGER_H
+
+#include <cups/string-private.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+
+#define OHUSB_TRANSFER_TYPE_MASK        0x03    /* in bmAttributes */
+#define OHUSB_ENDPOINT_DIR_MASK		    0x80
+
+const int OHUSB_CLASS_PRINTER = 7;
+const uint16_t OHUSB_LANGUAGE_ID_ENGLISH = 0x409;
+const int32_t OHUSB_GET_STRING_DESCRIPTOR_TIMEOUT = 1000;
+const int32_t OHUSB_STRING_DESCRIPTOR_LENGTH_INDEX = 0;
+
+const int32_t OHUSB_ENDPOINT_MAX_LENGTH = 512;
+const int32_t OHUSB_CONTROLTRANSFER_READ_SLEEP = 100;
+const int32_t OHUSB_CONTROLTRANSFER_READ_RETRY_MAX_TIMES = 20;
+const int32_t OHUSB_BULKTRANSFER_WRITE_SLEEP = 1000;
+const int32_t OHUSB_WRITE_RETRY_MAX_TIMES = 20;
+const int32_t OHUSB_BULKTRANSFER_READ_TIMEOUT = 5000;
+
+/*
+ * Transfer type
+ */
+typedef enum {
+	/** Control transfer */
+    OHUSB_TRANSFER_TYPE_CONTROL = 0U,
+
+    /** Isochronous transfer */
+    OHUSB_TRANSFER_TYPE_ISOCHRONOUS = 1U,
+
+    /** Bulk transfer */
+    OHUSB_TRANSFER_TYPE_BULK = 2U,
+
+    /** Interrupt transfer */
+    OHUSB_TRANSFER_TYPE_INTERRUPT = 3U,
+
+    /** Bulk stream transfer */
+    OHUSB_TRANSFER_TYPE_BULK_STREAM = 4U
+} ohusb_transfer_type;
+
+/*
+ * Request type bits.
+ */
+typedef enum {
+	/** Standard */
+    OHUSB_REQUEST_TYPE_STANDARD = (0x00 << 5),
+
+    /** Class */
+    OHUSB_REQUEST_TYPE_CLASS = (0x01 << 5),
+
+    /** Vendor */
+    OHUSB_REQUEST_TYPE_VENDOR = (0x02 << 5),
+
+    /** Reserved */
+    OHUSB_REQUEST_TYPE_RESERVED = (0x03 << 5)
+} ohusb_request_type;
+
+/*
+ * Endpoint direction.
+ */
+typedef enum {
+	/** Out: host-to-device */
+    OHUSB_ENDPOINT_OUT = 0x00,
+
+    /** In: device-to-host */
+    OHUSB_ENDPOINT_IN = 0x80
+} ohusb_endpoint_direction;
+
+/*
+ * Recipient bits of the requestType.
+ */
+typedef enum {
+	/** Device */
+    OHUSB_RECIPIENT_DEVICE = 0x00,
+
+    /** Interface */
+    OHUSB_RECIPIENT_INTERFACE = 0x01,
+
+    /** Endpoint */
+    OHUSB_RECIPIENT_ENDPOINT = 0x02,
+
+    /** Other */
+    OHUSB_RECIPIENT_OTHER = 0x03
+} ohusb_request_recipient;
+
+/*
+ * Standard requests
+ */
+typedef enum {
+	/** Request status of the specific recipient */
+    OHUSB_REQUEST_GET_STATUS = 0x00,
+    
+    /** Clear or disable a specific feature */
+    OHUSB_REQUEST_CLEAR_FEATURE = 0x01,
+    
+    /* 0x02 is reserved */
+    
+    /** Set or enable a specific feature */
+    OHUSB_REQUEST_SET_FEATURE = 0x03,
+    
+    /* 0x04 is reserved */
+    
+    /** Set device address for all future accesses */
+    OHUSB_REQUEST_SET_ADDRESS = 0x05,
+    
+    /** Get the specified descriptor */
+    OHUSB_REQUEST_GET_DESCRIPTOR = 0x06,
+    
+    /** Used to update existing descriptors or add new descriptors */
+    OHUSB_REQUEST_SET_DESCRIPTOR = 0x07,
+    
+    /** Get the current device configuration value */
+    OHUSB_REQUEST_GET_CONFIGURATION = 0x08,
+    
+    /** Set device configuration */
+    OHUSB_REQUEST_SET_CONFIGURATION = 0x09,
+    
+    /** Return the selected alternate setting for the specified interface */
+    OHUSB_REQUEST_GET_INTERFACE = 0x0a,
+
+    /** Select an alternate interface for the specified interface */
+    OHUSB_REQUEST_SET_INTERFACE = 0x0b,
+
+    /** Set then report an endpoint's synchronization frame */
+    OHUSB_REQUEST_SYNCH_FRAME = 0x0c,
+
+    /** Sets both the U1 and U2 Exit Latency */
+    OHUSB_REQUEST_SET_SEL = 0x30,
+
+    /** Delay from the time a host transmits a packet to the time it is
+      * received by the device. */
+    OHUSB_SET_ISOCH_DELAY = 0x31
+} ohusb_standard_request;
+
+/*
+ * Descriptor types as defined by the USB specification.
+ */
+typedef enum {
+	/** Device descriptor */
+	OHUSB_DT_DEVICE = 0x01,
+
+	/** Configuration descriptor */
+	OHUSB_DT_CONFIG = 0x02,
+
+	/** String descriptor */
+    OHUSB_DT_STRING = 0x03,
+
+    /** Interface descriptor */
+    OHUSB_DT_INTERFACE = 0x04,
+
+    /** Endpoint descriptor */
+    OHUSB_DT_ENDPOINT = 0x05,
+
+    /** Interface Association Descriptor */
+    OHUSB_DT_INTERFACE_ASSOCIATION = 0x0b,
+
+    /** BOS descriptor */
+    OHUSB_DT_BOS = 0x0f,
+
+    /** Device Capability descriptor */
+    OHUSB_DT_DEVICE_CAPABILITY = 0x10,
+
+    /** HID descriptor */
+    OHUSB_DT_HID = 0x21,
+
+    /** HID report descriptor */
+    OHUSB_DT_REPORT = 0x22,
+
+    /** Physical descriptor */
+    OHUSB_DT_PHYSICAL = 0x23,
+
+    /** Hub descriptor */
+    OHUSB_DT_HUB = 0x29,
+
+    /** SuperSpeed Hub descriptor */
+    OHUSB_DT_SUPERSPEED_HUB = 0x2a,
+
+    /** SuperSpeed Endpoint Companion descriptor */
+    OHUSB_DT_SS_ENDPOINT_COMPANION = 0x30
+} ohusb_descriptor_type;
+
+/**
+ * Error codes.
+ */
+typedef enum {
+	/** Success (no error) */
+	OHUSB_SUCCESS = 0,
+
+	/** Input/output error */
+	OHUSB_ERROR_IO = -1,
+
+	/** Invalid parameter */
+	OHUSB_ERROR_INVALID_PARAM = -2,
+
+	/** Access denied (insufficient permissions) */
+	OHUSB_ERROR_ACCESS = -3,
+
+	/** No such device (it may have been disconnected) */
+	OHUSB_ERROR_NO_DEVICE = -4,
+
+	/** Entity not found */
+	OHUSB_ERROR_NOT_FOUND = -5,
+
+	/** Resource busy */
+	OHUSB_ERROR_BUSY = -6,
+
+	/** Operation timed out */
+	OHUSB_ERROR_TIMEOUT = -7,
+
+	/** Overflow */
+	OHUSB_ERROR_OVERFLOW = -8,
+
+	/** Pipe error */
+	OHUSB_ERROR_PIPE = -9,
+
+	/** System call interrupted (perhaps due to signal) */
+	OHUSB_ERROR_INTERRUPTED = -10,
+
+	/** Insufficient memory */
+	OHUSB_ERROR_NO_MEM = -11,
+
+	/** Operation not supported or unimplemented on this platform */
+	OHUSB_ERROR_NOT_SUPPORTED = -12,
+
+	/** Other error */
+	OHUSB_ERROR_OTHER = -99
+} ohusb_error;
+
+/**
+ * A structure representing the parameter for usb control transfer.
+ */
+typedef struct {
+    /** Request type */
+    int32_t requestType;
+
+    /** Request */
+    int32_t request;
+
+    /** Value. Varies according to request */
+    int32_t value;
+
+    /** Index. Varies according to request, typically used to pass an index
+	 * or offset */
+    int32_t index;
+
+    /** timeout */
+    int32_t timeout;
+} ohusb_control_transfer_parameter;
+
+/**
+ * A structure representing the standard USB endpoint descriptor.
+ */
+typedef struct {
+    /** Descriptor type */
+    uint8_t  bDescriptorType;
+
+    /** The address of the endpoint described by this descriptor. Bits 0:3 are
+	 * the endpoint number. Bits 4:6 are reserved. Bit 7 indicates direction. */
+    uint8_t  bEndpointAddress;
+
+    /** Attributes which apply to the endpoint when it is configured using
+	 * the bConfigurationValue. Bits 0:1 determine the transfer type. Bits 2:3 are
+     * only used for isochronous endpoints. Bits 4:5 are also only used for
+     * isochronous endpoints . Bits 6:7 are reserved. */
+    uint8_t  bmAttributes;
+
+    /** Maximum packet size this endpoint is capable of sending/receiving. */
+    uint16_t wMaxPacketSize;
+
+    /** Interval for polling endpoint for data transfers. */
+    uint8_t  bInterval;
+
+    /** The interface id the endpoint belongs to. */
+    uint8_t  bInterfaceId;
+
+    /** The direction of the endpoint. */
+    uint32_t direction;
+} ohusb_endpoint_descriptor;
+
+/**
+ * A structure representing the standard USB interface descriptor.
+ */
+typedef struct {
+    /** Number of this interface */
+    uint8_t  bInterfaceNumber;
+
+    /** Value used to select this alternate setting for this interface */
+    uint8_t  bAlternateSetting;
+
+    /** USB-IF class code for this interface. */
+    uint8_t  bInterfaceClass;
+
+    /** USB-IF subclass code for this interface, qualified by the
+	 * bInterfaceClass value */
+    uint8_t  bInterfaceSubClass;
+
+    /** USB-IF protocol code for this interface, qualified by the
+	 * bInterfaceClass and bInterfaceSubClass values */
+    uint8_t  bInterfaceProtocol;
+
+    /** Array of endpoint descriptors. This length of this array is determined
+	 * by the bNumEndpoints field. */
+    ohusb_endpoint_descriptor *endpoint;
+
+    /** Number of endpoints used by this interface (excluding the control
+	 * endpoint). */
+    uint8_t  bNumEndpoints;
+} ohusb_interface_descriptor;
+
+/**
+ * A collection of alternate settings for a particular USB interface.
+ */
+typedef struct {
+    /** Array of interface descriptors. The length of this array is determined
+	 * by the num_altsetting field. */
+    ohusb_interface_descriptor *altsetting;
+
+    /** The number of alternate settings that belong to this interface.
+	 * Must be non-negative. */
+    int num_altsetting;
+} ohusb_interface;
+
+/**
+ * A structure representing the standard USB configuration descriptor.
+ */
+typedef struct {
+    /** Identifier value for this configuration */
+    uint8_t iConfiguration;
+
+    /** Configuration characteristics */
+    uint8_t bmAttributes;
+
+    /** Maximum power consumption of the USB device from this bus in this
+	 * configuration when the device is fully operation. Expressed in units
+	 * of 2 mA when the device is operating in high-speed mode and in units
+	 * of 8 mA when the device is operating in super-speed mode. */
+    uint8_t MaxPower;
+
+    /** Array of interfaces supported by this configuration. The length of
+	 * this array is determined by the bNumInterfaces field. */
+    ohusb_interface *interface;
+
+    /** Number of interfaces supported by this configuration */
+    uint8_t bNumInterfaces;
+} ohusb_config_descriptor;
+
+/**
+ * A structure representing the standard USB device descriptor.
+ */
+typedef struct {
+    /** The bus num of the usb device. */
+    uint8_t busNum;
+
+    /** The device address of the usb device. */
+    uint8_t devAddr;
+
+    /** USB specification release number in binary-coded decimal. A value of
+	 * 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc. */
+    uint16_t bcdUSB;
+
+    /** USB-IF class code for the device. */
+    uint8_t bDeviceClass;
+
+    /** USB-IF subclass code for the device, qualified by the bDeviceClass
+	 * value */
+    uint8_t bDeviceSubClass;
+
+    /** USB-IF protocol code for the device, qualified by the bDeviceClass and
+	 * bDeviceSubClass values */
+    uint8_t bDeviceProtocol;
+
+    /** Maximum packet size for endpoint 0 */
+    uint8_t bMaxPacketSize0;
+
+    /** USB-IF vendor ID */
+    uint16_t idVendor;
+
+    /** USB-IF product ID */
+    uint16_t idProduct;
+
+    /** Device release number in binary-coded decimal */
+    uint16_t bcdDevice;
+
+    /** Index of string descriptor describing manufacturer */
+    uint8_t iManufacturer;
+
+    /** Index of string descriptor describing product */
+    uint8_t iProduct;
+
+    /** Index of string descriptor containing device serial number */
+    uint8_t iSerialNumber;
+
+    /** Array of configs supported by this device. The length of
+	 * this array is determined by the bNumConfigurations field. */
+    ohusb_config_descriptor *config;
+
+    /** Number of configs supported by this device */
+    uint8_t bNumConfigurations;
+} ohusb_device_descriptor;
+
+/**
+ * A structure representing the pipe information to transfer data.
+ */
+typedef struct {
+    /** The bus num of the usb device. */
+    uint8_t busNum;
+
+    /** The device address of the usb device. */
+    uint8_t devAddr;
+} ohusb_pipe;
+
+/**
+ * A structure representing the endpoint information to transfer data.
+ */
+typedef struct {
+    /** The interface id to which the endpoint to transmit data belongs. */
+    uint8_t bInterfaceId;
+
+    /** The endpoint address to transfer data. */
+    uint8_t bEndpointAddress;
+} ohusb_transfer_pipe;
+
+extern int32_t OH_GetDevices(ohusb_device_descriptor** list, ssize_t *numdevs);
+extern int32_t OH_OpenDevice(ohusb_device_descriptor *devDesc, ohusb_pipe **pipe);
+extern int32_t OH_CloseDevice(ohusb_pipe *pipe);
+extern int32_t OH_ClaimInterface(ohusb_pipe *pipe, int interfaceId, bool force);
+extern int32_t OH_ReleaseInterface(ohusb_pipe *pipe, int interfaceId);
+extern int32_t OH_BulkTransferRead(
+    ohusb_pipe *pipe, ohusb_transfer_pipe *tpipe, unsigned char *data, int length, int *transferred);
+extern int32_t OH_BulkTransferWrite(
+    ohusb_pipe *pipe, ohusb_transfer_pipe *tpipe, unsigned char *data, int length, int *transferred, int32_t timeout);
+extern int32_t OH_ControlTransferRead(
+    ohusb_pipe *pipe, ohusb_control_transfer_parameter *ctrlParam, unsigned char *data, uint16_t length);
+extern int32_t OH_ControlTransferWrite(
+    ohusb_pipe *pipe, ohusb_control_transfer_parameter *ctrlParam, unsigned char *data, uint16_t length);
+extern int32_t OH_GetStringDescriptor(ohusb_pipe *pipe, int descId, unsigned char *descriptor, int length);
+extern int32_t OH_SetConfiguration(ohusb_pipe *pipe, int configIndex);
+extern int32_t OH_SetInterface(ohusb_pipe *pipe, int interfaceId, int altIndex);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* USB_MANAGER_H */
\ No newline at end of file