| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | #include <ddk/ntddk.h> |
| 4 | #include <intrin.h> |
| 5 | |
| 6 | #define MSR_IA32_THERM_STATUS 0x19C |
| 7 | #define MSR_DEVICE_NAME L"\\Device\\NDDrv" |
| 8 | #define MSR_DOSLINK_NAME L"\\DosDevices\\NDDrv" |
| 9 | |
| 10 | #define IOCTL_MSR_READ CTL_CODE(FILE_DEVICE_UNKNOWN, 0x800, METHOD_BUFFERED, FILE_ANY_ACCESS) |
| 11 | |
| 12 | typedef struct _MSR_REQUEST { |
| 13 | ULONG msr; |
| 14 | ULONG cpu; |
| 15 | ULONG low; |
| 16 | ULONG high; |
| 17 | } MSR_REQUEST, *PMSR_REQUEST; |
| 18 | |
| 19 | DRIVER_UNLOAD NetdataMsrUnload; |
| 20 | DRIVER_DISPATCH NetdataMsrCreateClose; |
| 21 | DRIVER_DISPATCH NetdataMsrDeviceControl; |
| 22 | |
| 23 | static UNICODE_STRING g_DeviceName = RTL_CONSTANT_STRING(MSR_DEVICE_NAME); |
| 24 | static UNICODE_STRING g_DosLinkName = RTL_CONSTANT_STRING(MSR_DOSLINK_NAME); |
| 25 | |
| 26 | VOID NetdataMsrUnload(_In_ PDRIVER_OBJECT DriverObject) |
| 27 | { |
| 28 | IoDeleteSymbolicLink(&g_DosLinkName); |
| 29 | |
| 30 | if (DriverObject->DeviceObject) { |
| 31 | IoDeleteDevice(DriverObject->DeviceObject); |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | NTSTATUS NetdataMsrCreateClose(_In_ PDEVICE_OBJECT DeviceObject, _Inout_ PIRP Irp) |
| 36 | { |
| 37 | UNREFERENCED_PARAMETER(DeviceObject); |
| 38 | |
| 39 | Irp->IoStatus.Status = STATUS_SUCCESS; |
| 40 | Irp->IoStatus.Information = 0; |
| 41 | IoCompleteRequest(Irp, IO_NO_INCREMENT); |
| 42 | return STATUS_SUCCESS; |
| 43 | } |
| 44 | |
| 45 | NTSTATUS NetdataMsrDeviceControl(_In_ PDEVICE_OBJECT DeviceObject, _Inout_ PIRP Irp) |
| 46 | { |
| 47 | UNREFERENCED_PARAMETER(DeviceObject); |
| 48 | |
| 49 | PIO_STACK_LOCATION irpSp = IoGetCurrentIrpStackLocation(Irp); |
| 50 | NTSTATUS status = STATUS_SUCCESS; |
| 51 | ULONG information = 0; |
| 52 | |
| 53 | if (irpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_MSR_READ) { |
| 54 | if (irpSp->Parameters.DeviceIoControl.InputBufferLength < sizeof(MSR_REQUEST) || |
| 55 | irpSp->Parameters.DeviceIoControl.OutputBufferLength < sizeof(MSR_REQUEST)) { |
| 56 | status = STATUS_BUFFER_TOO_SMALL; |
| 57 | } else { |
| 58 | PMSR_REQUEST req = (PMSR_REQUEST)Irp->AssociatedIrp.SystemBuffer; |
| 59 | |
| 60 | ULONG maxCpus = KeQueryActiveProcessorCountEx(ALL_PROCESSOR_GROUPS); |
| 61 | if (req->cpu >= maxCpus) { |
| 62 | status = STATUS_INVALID_PARAMETER; |
| 63 | } else { |
| 64 | KAFFINITY cpuMask = 1ull << req->cpu; |
| 65 | KAFFINITY oldMask = KeSetSystemAffinityThreadEx(cpuMask); |
| 66 | |
| 67 | ULONGLONG value = __readmsr(req->msr); |
| 68 | req->low = (ULONG)(value & 0xFFFFFFFF); |
| 69 | req->high = (ULONG)(value >> 32); |
| 70 | information = sizeof(MSR_REQUEST); |
| 71 | |
| 72 | KeRevertToUserAffinityThreadEx(oldMask); |
| 73 | } |
| 74 | } |
| 75 | } else { |
| 76 | status = STATUS_INVALID_DEVICE_REQUEST; |
| 77 | } |
| 78 | |
| 79 | Irp->IoStatus.Status = status; |
| 80 | Irp->IoStatus.Information = information; |
| 81 | IoCompleteRequest(Irp, IO_NO_INCREMENT); |
| 82 | |
| 83 | return status; |
| 84 | } |
| 85 | |
| 86 | NTSTATUS DriverEntry(_In_ PDRIVER_OBJECT DriverObject, _In_ PUNICODE_STRING RegistryPath) |
| 87 | { |
| 88 | UNREFERENCED_PARAMETER(RegistryPath); |
| 89 | NTSTATUS status; |
| 90 | PDEVICE_OBJECT deviceObject = NULL; |
| 91 | |
| 92 | status = IoCreateDevice( |
| 93 | DriverObject, |
| 94 | 0, |
| 95 | &g_DeviceName, |
| 96 | FILE_DEVICE_UNKNOWN, |
| 97 | FILE_DEVICE_SECURE_OPEN, |
| 98 | FALSE, |
| 99 | &deviceObject |
| 100 | ); |
| 101 | |
| 102 | if (!NT_SUCCESS(status)) { |
| 103 | return status; |
| 104 | } |
| 105 | |
| 106 | status = IoCreateSymbolicLink(&g_DosLinkName, &g_DeviceName); |
| 107 | if (!NT_SUCCESS(status)) { |
| 108 | IoDeleteDevice(deviceObject); |
| 109 | return status; |
| 110 | } |
| 111 | |
| 112 | deviceObject->Flags |= DO_BUFFERED_IO; |
| 113 | |
| 114 | DriverObject->MajorFunction[IRP_MJ_CREATE] = NetdataMsrCreateClose; |
| 115 | DriverObject->MajorFunction[IRP_MJ_CLOSE] = NetdataMsrCreateClose; |
| 116 | DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = NetdataMsrDeviceControl; |
| 117 | DriverObject->DriverUnload = NetdataMsrUnload; |
| 118 | |
| 119 | deviceObject->Flags &= ~DO_DEVICE_INITIALIZING; |
| 120 | |
| 121 | return STATUS_SUCCESS; |
| 122 | } |