Tool to dump CallNtPowerInformation(GetPowerRequestList) results

GetPowerRequestList.c

#define _WIN32_WINNT 0x0602
#define UMDF_USING_NTSTATUS
#include <stdio.h>
#include <windows.h>
#include <powerbase.h>
#include <stdbool.h>
#include <ntstatus.h>
#include <shlobj.h>
#pragma comment(lib, "PowrProf.lib")

typedef NTSTATUS PowerInformationWithPrivileges_t(
	POWER_INFORMATION_LEVEL InformationLevel,
	PVOID                   InputBuffer,
	ULONG                   InputBufferLength,
	PVOID                   OutputBuffer,
	ULONG                   OutputBufferLength
);

static PowerInformationWithPrivileges_t* PowerInformationWithPrivileges = NULL;

NTSTATUS QueryPowerInformationLevel(POWER_INFORMATION_LEVEL InformationLevel, void** OutBuf, ULONG* OutSize) {
	if (PowerInformationWithPrivileges == NULL) {
		// Call LoadModule to load powrprof.dll
		HMODULE hPowrProf = LoadLibraryA("powrprof.dll");
		if (hPowrProf == NULL) {
			printf("ERROR: LoadLibraryA(\"powrprof.dll\") failed with error %d\n", GetLastError());
			return STATUS_UNSUCCESSFUL;
		}
		// Use GetProcAddress to get PowerInformationWithPrivileges function from hPowrProf
		// and stick it in PowerInformationWithPrivileges global variable
		PowerInformationWithPrivileges = (PowerInformationWithPrivileges_t*)GetProcAddress(hPowrProf, "PowerInformationWithPrivileges");
		if (PowerInformationWithPrivileges == NULL) {
			printf("ERROR: GetProcAddress(\"PowerInformationWithPrivileges\") failed with error %d\n", GetLastError());
			return STATUS_UNSUCCESSFUL;
		}
	}
	if (OutSize != NULL) *OutSize = 0;
	ULONG OutputBufferLength = 0x40;
	PVOID OutputBuffer = malloc(OutputBufferLength);
	if (OutputBuffer == NULL) {
		printf("ERROR: malloc() could not allocate %lu bytes\n", OutputBufferLength);
		return STATUS_NO_MEMORY;
	}
	while (true) {
		NTSTATUS status = PowerInformationWithPrivileges(InformationLevel, NULL, 0, OutputBuffer, OutputBufferLength);
		if (status == STATUS_BUFFER_TOO_SMALL) {
			// Resize the buffer
			OutputBufferLength *= 2;
			PVOID NewOutputBuffer = realloc(OutputBuffer, OutputBufferLength);
			if (NewOutputBuffer == NULL) {
				printf("ERROR: realloc() could not resize the buffer to %lu bytes\n", OutputBufferLength);
				free(OutputBuffer);
				return STATUS_NO_MEMORY;
			}
			OutputBuffer = NewOutputBuffer;
		}
		else if (status == STATUS_SUCCESS) {
			if (OutSize != NULL) *OutSize = OutputBufferLength;
			*OutBuf = OutputBuffer;
			return status;
		}
		else {
			free(OutputBuffer);
			return status;
		}
	}
}

int main(int argc, char* argv[]) {
	printf("GetPowerRequestList tool\n\n");
	if (!IsUserAnAdmin()) {
		printf("ERROR: You must run this program as an administrator\n");
		return 1;
	}

	void* OutBuf = NULL;
	ULONG OutSize = 0;
	NTSTATUS status = QueryPowerInformationLevel(GetPowerRequestList, &OutBuf, &OutSize);
	if (status != STATUS_SUCCESS) {
		printf("ERROR: GetPowerRequestList failed with status=%08x\n", status);
		return 1;
	}
	SIZE_T* count = (SIZE_T*)OutBuf;
	printf("GetPowerRequestList entry count=%zu\n", count[0]);
	for (int i = 0; i < count[0]; i++) {
		SIZE_T startOffset = count[i + 1];
		SIZE_T endOffset = i == count[0] - 1 ? OutSize : count[i + 2];
		SIZE_T size = endOffset - startOffset;
		printf("GetPowerRequestList entry %d: startOffset=%zu endOffset=%zu size=%zu\n",
			i, startOffset, endOffset, size);
		// Dump all text found in entry
		printf("\t[");
		WCHAR* ptr = (WCHAR*)((SIZE_T)OutBuf + startOffset);
		bool spaceOut = true;
		for (int j = 0; j < (size / 2); j++) {
			int ch = ptr[j];
			if (ch > 0x20 && ch < 0x7f) {
				spaceOut = false;
				printf("%c", ptr[j]);
			}
			else if (!spaceOut) {
				printf(" ");
				spaceOut = true;

			}
		}
		printf("]\n");
	}
	return 0;
}