com.sun.jna.platform.win32.Cfgmgr32Util Maven / Gradle / Ivy
/* Copyright (c) 2018, 2021 Daniel Widdis, All Rights Reserved
*
* The contents of this file is dual-licensed under 2
* alternative Open Source/Free licenses: LGPL 2.1 or later and
* Apache License 2.0. (starting with JNA version 4.0.0).
*
* You can freely decide which license you want to apply to
* the project.
*
* You may obtain a copy of the LGPL License at:
*
* http://www.gnu.org/licenses/licenses.html
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "LGPL2.1".
*
* You may obtain a copy of the Apache License at:
*
* http://www.apache.org/licenses/
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "AL2.0".
*/
package com.sun.jna.platform.win32;
import com.sun.jna.Memory;
import com.sun.jna.Native;
import com.sun.jna.ptr.IntByReference;
import com.sun.jna.win32.W32APITypeMapper;
/**
* Cfgmgr32 utility API.
*/
public abstract class Cfgmgr32Util {
@SuppressWarnings("serial")
public static class Cfgmgr32Exception extends RuntimeException {
private final int errorCode;
public Cfgmgr32Exception(int errorCode) {
this.errorCode = errorCode;
}
public int getErrorCode() {
return errorCode;
}
@Override
public String toString() {
return super.toString() + String.format(" [errorCode: 0x%08x]", errorCode);
}
}
/**
* Utility method to call Cfgmgr32's CM_Get_Device_ID_Size, allocates the
* required memory for the Buffer parameter based on the type mapping used,
* calls to CM_Get_Device_ID, and returns the received string.
*
* @param devInst
* Caller-supplied device instance handle that is bound to the local
* machine.
* @return The device instance ID string.
* @throws Cfgmgr32Exception
*/
public static String CM_Get_Device_ID(int devInst) throws Cfgmgr32Exception {
int charToBytes = Boolean.getBoolean("w32.ascii") ? 1 : Native.WCHAR_SIZE;
// Get Device ID character count
IntByReference pulLen = new IntByReference();
int ret = Cfgmgr32.INSTANCE.CM_Get_Device_ID_Size(pulLen, devInst, 0);
if (ret != Cfgmgr32.CR_SUCCESS) {
throw new Cfgmgr32Exception(ret);
}
// Add one to length to allow null terminator
Memory buffer = new Memory((pulLen.getValue() + 1) * charToBytes);
// Zero the buffer (including the extra character)
buffer.clear();
// Fetch the buffer specifying only the current length
ret = Cfgmgr32.INSTANCE.CM_Get_Device_ID(devInst, buffer, pulLen.getValue(), 0);
// In the unlikely event the device id changes this might not be big
// enough, try again. This happens rarely enough one retry should be
// sufficient.
if (ret == Cfgmgr32.CR_BUFFER_SMALL) {
ret = Cfgmgr32.INSTANCE.CM_Get_Device_ID_Size(pulLen, devInst, 0);
if (ret != Cfgmgr32.CR_SUCCESS) {
throw new Cfgmgr32Exception(ret);
}
buffer = new Memory((pulLen.getValue() + 1) * charToBytes);
buffer.clear();
ret = Cfgmgr32.INSTANCE.CM_Get_Device_ID(devInst, buffer, pulLen.getValue(), 0);
}
// If we still aren't successful throw an exception
if (ret != Cfgmgr32.CR_SUCCESS) {
throw new Cfgmgr32Exception(ret);
}
// Convert buffer to Java String
if (charToBytes == 1) {
return buffer.getString(0);
} else {
return buffer.getWideString(0);
}
}
/**
* Utility method to call Cfgmgr32's CM_Get_DevNode_Registry_Property that
* allocates the required memory for the Buffer parameter, and returns values of
* the appropriate type.
*
* @param devInst
* Caller-supplied device instance handle that is bound to the local
* machine.
* @param ulProperty
* A {@code CM_DRP_}-prefixed constant value that identifies the
* device property to be obtained from the registry. These constants
* are defined in Cfgmgr32.h.
* @return An {@link Object} containing the specified registry property for the
* device.
*
* If the property is of type {@link WinNT#REG_SZ}, a
* {@link java.lang.String} is returned.
*
* If the property is of type {@link WinNT#REG_MULTI_SZ}, an array of
* {@link java.lang.String} is returned.
*
* If the property is of type {@link WinNT#REG_DWORD}, an
* {@link java.lang.Integer} is returned.
*
* If the property is of type {@link WinNT#REG_BINARY}, an array of
* {@link java.lang.Byte} is returned.
*
* If no value exists for this property (error
* {@link Cfgmgr32#CR_NO_SUCH_VALUE}), returns {@code null}.
* @throws Cfgmgr32Exception
* on any errors other than {@link Cfgmgr32#CR_NO_SUCH_VALUE}
*/
public static Object CM_Get_DevNode_Registry_Property(int devInst, int ulProperty) throws Cfgmgr32Exception {
// Get byte count and type
IntByReference size = new IntByReference();
IntByReference type = new IntByReference();
int ret = Cfgmgr32.INSTANCE.CM_Get_DevNode_Registry_Property(devInst, ulProperty, type, null, size, 0);
// If this property does not exist return null
if (ret == Cfgmgr32.CR_NO_SUCH_VALUE) {
return null;
}
// If successful in retrieving type and size, should fail with CR_BUFFER_SMALL,
// otherwise throw an exception
if (ret != Cfgmgr32.CR_BUFFER_SMALL) {
throw new Cfgmgr32Exception(ret);
}
// It is possible to have a valid value with registry data type, but 0 size.
// Leave the memory buffer null in that case
Memory buffer = null;
if (size.getValue() > 0) {
buffer = new Memory(size.getValue());
ret = Cfgmgr32.INSTANCE.CM_Get_DevNode_Registry_Property(devInst, ulProperty, type, buffer, size, 0);
if (ret != Cfgmgr32.CR_SUCCESS) {
throw new Cfgmgr32Exception(ret);
}
}
// Get the appropriate type of data from the buffer
switch (type.getValue()) {
case WinNT.REG_SZ:
// Convert buffer to Java String
if (buffer == null) {
return "";
}
return W32APITypeMapper.DEFAULT == W32APITypeMapper.UNICODE ? buffer.getWideString(0)
: buffer.getString(0);
case WinNT.REG_MULTI_SZ:
// Convert buffer to String Array
if (buffer == null) {
return new String[0];
}
return Advapi32Util.regMultiSzBufferToStringArray(buffer);
case WinNT.REG_DWORD:
// Convert buffer to int
if (buffer == null) {
return 0;
}
return buffer.getInt(0);
case WinNT.REG_NONE:
return null;
default:
// Intended for WinNT.REG_BINARY but safe default for any data
if (buffer == null) {
return new byte[0];
}
// Convert buffer to array of bytes
return buffer.getByteArray(0, (int) buffer.size());
}
}
}