NTSTATUS
FmCreateDosDevicesSymbolicLink(
WDFDEVICE Device,
PFM_DEVICE_DATA FmDeviceData
)
{
NTSTATUS status;
UNICODE_STRING comPort;
UNICODE_STRING pdoName;
UNICODE_STRING symbolicLink;
WDFKEY hKey = NULL;
DECLARE_CONST_UNICODE_STRING(valueName, L"PortName");
WDFSTRING string = NULL;
WDFMEMORY memory;
WDF_OBJECT_ATTRIBUTES memoryAttributes;
size_t bufferLength;
PAGED_CODE();
symbolicLink.Buffer = NULL;
//
// Open the device registry and read the "PortName" value written by the
// class installer.
//
status = WdfDeviceOpenRegistryKey(Device,
PLUGPLAY_REGKEY_DEVICE,
STANDARD_RIGHTS_ALL,
NULL, // PWDF_OBJECT_ATTRIBUTES
&hKey);
if (!NT_SUCCESS (status)) {
goto Error;
}
status = WdfStringCreate(
NULL,
WDF_NO_OBJECT_ATTRIBUTES ,
&string
);
if (!NT_SUCCESS(status)) {
goto Error;
}
//
// Retrieve the value of ValueName from registry
//
status = WdfRegistryQueryString(
hKey,
&valueName,
string
);
if (!NT_SUCCESS (status)) {
goto Error;
}
//
// Retrieve the UNICODE_STRING from string object
//
WdfStringGetUnicodeString(
string,
&comPort
);
WdfRegistryClose(hKey);
hKey = NULL;
symbolicLink.Length=0;
symbolicLink.MaximumLength = sizeof(OBJECT_DIRECTORY) + comPort.MaximumLength;
symbolicLink.Buffer = ExAllocatePoolWithTag(PagedPool,
symbolicLink.MaximumLength + sizeof(WCHAR),
'wkaF');
if (symbolicLink.Buffer == NULL) {
status = STATUS_INSUFFICIENT_RESOURCES;
goto Error;
}
RtlZeroMemory(symbolicLink.Buffer, symbolicLink.MaximumLength);
RtlAppendUnicodeToString(&symbolicLink, OBJECT_DIRECTORY);
RtlAppendUnicodeStringToString(&symbolicLink, &comPort);
//
// This DDI will get the underlying PDO name and create a symbolic to that
// because our FDO doesn't have a name.
//
status = WdfDeviceCreateSymbolicLink(Device,
&symbolicLink);
if (!NT_SUCCESS(status)) {
goto Error;
}
WDF_OBJECT_ATTRIBUTES_INIT(&memoryAttributes);
memoryAttributes.ParentObject = Device;
status = WdfDeviceAllocAndQueryProperty(Device,
DevicePropertyPhysicalDeviceObjectName,
PagedPool,
&memoryAttributes,
&memory);
if (!NT_SUCCESS(status)) {
//
// We expect a zero length buffer. Anything else is fatal.
//
goto Error;
}
pdoName.Buffer = WdfMemoryGetBuffer(memory, &bufferLength);
if (pdoName.Buffer == NULL) {
status = STATUS_INSUFFICIENT_RESOURCES;
goto Error;
}
pdoName.MaximumLength = (USHORT) bufferLength;
pdoName.Length = (USHORT) bufferLength - sizeof(UNICODE_NULL);
status = RtlWriteRegistryValue(RTL_REGISTRY_DEVICEMAP,
L"SERIALCOMM",
pdoName.Buffer,
REG_SZ,
comPort.Buffer,
comPort.Length);
if (!NT_SUCCESS(status)) {
goto Error;
}
FmDeviceData->Flags |= REG_VALUE_CREATED_FLAG;
//
// Store it so it can be deleted later.
//
FmDeviceData->PdoName = pdoName;
Error:
if (symbolicLink.Buffer != NULL) {
ExFreePool(symbolicLink.Buffer);
}
if (hKey != NULL) {
WdfRegistryClose(hKey);
}
if (string != NULL) {
WdfObjectDelete(string);
}
return status;
}
//-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- DriverParametersKeyRead -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
//
NTSTATUS DriverParametersKeyRead(
WDFDRIVER Driver,
DtString* pKeyName,
DtString* pValueName,
Int64* pBinValue,
DtString* pStrValue)
{
NTSTATUS NtStatus;
WDFKEY ParametersKey;
WDFKEY Key = NULL;
WDFSTRING WdfString = NULL;
DtString RegStrValue;
DT_ASSERT(KeGetCurrentIrql()<=PASSIVE_LEVEL);
// Only one value can be requested
DT_ASSERT((pBinValue!=NULL && pStrValue==NULL)||(pBinValue==NULL && pStrValue!=NULL));
// Open the drivers parameters key (under services)
NtStatus = WdfDriverOpenParametersRegistryKey(Driver, KEY_READ,
WDF_NO_OBJECT_ATTRIBUTES, &ParametersKey);
if (!NT_SUCCESS(NtStatus))
{
DtDbgOut(ERR, SAL, "WdfDriverOpenParametersRegistryKey failed. Error: 0x%x",
NtStatus);
return NtStatus;
}
// Open subkey
NtStatus = WdfRegistryOpenKey(ParametersKey, pKeyName, KEY_READ,
WDF_NO_OBJECT_ATTRIBUTES, &Key);
if (!NT_SUCCESS(NtStatus))
{
if (NtStatus == STATUS_OBJECT_NAME_NOT_FOUND)
DtDbgOut(MAX, SAL, "WdfRegistryOpenKey error:'STATUS_OBJECT_NAME_NOT_FOUND'");
else
DtDbgOut(ERR, SAL, "WdfRegistryOpenKey failed. Error: 0x%x", NtStatus);
}
if (NT_SUCCESS(NtStatus))
{
// Read string or binary value
if (pStrValue != NULL)
{
// Set string attributes with the key as parent object, so that the string
// object is freed when the key object is destroyed. If we donot do this the
// string object is freed when the driver unloads, meaning that the each call
// to DriverParametersKeyRead result in an increase of memory usage, only
// to be freed on the unload.
WDF_OBJECT_ATTRIBUTES WdfStringAttr;
WDF_OBJECT_ATTRIBUTES_INIT(&WdfStringAttr);
WdfStringAttr.ParentObject = Key;
NtStatus = WdfStringCreate(pStrValue, &WdfStringAttr, &WdfString);
// Read string from registry
if (NT_SUCCESS(NtStatus))
NtStatus = WdfRegistryQueryString(Key, pValueName, WdfString);
// Convert WdfString to DtString
if (NT_SUCCESS(NtStatus))
WdfStringGetUnicodeString(WdfString, &RegStrValue);
// Make a copy of the string
if (NT_SUCCESS(NtStatus))
NtStatus = DtStringClear(pStrValue);
if (NT_SUCCESS(NtStatus))
NtStatus = DtStringAppendDtString(pStrValue, &RegStrValue);
}
else
NtStatus = WdfRegistryQueryValue(Key, pValueName, sizeof(Int64), pBinValue,
NULL, NULL);
if (!NT_SUCCESS(NtStatus))
{
if (NtStatus == STATUS_OBJECT_NAME_NOT_FOUND)
DtDbgOut(MAX, SAL, "WdfRegistryQueryValue error:"
"'STATUS_OBJECT_NAME_NOT_FOUND'");
else
DtDbgOut(ERR, SAL, "WdfRegistryQueryValue failed. Error: 0x%x", NtStatus);
}
}
if (Key != NULL)
WdfRegistryClose(Key);
WdfRegistryClose(ParametersKey);
return NtStatus;
}
