/// <summary>
/// Copies sections from a native module file block to the new memory location.
/// </summary>
/// <param name="ptr_data">Pointer to a native module byte array.</param>
/// <param name="ptr_old_headers">Pointer to a source native module headers.</param>
/// <param name="memory_module">Pointer to a memory module.</param>
private void CopySections(byte *ptr_data, byte *ptr_old_headers, MEMORY_MODULE *memory_module)
{
byte *codeBase = memory_module->codeBase;
WinNT.IMAGE_SECTION_HEADER *section = WinNT.IMAGE_FIRST_SECTION(memory_module->headers);
ushort numberOfSections;
uint sectionAlignment;
if (Environment.Is64BitProcess)
{
WinNT.IMAGE_NT_HEADERS64 *new_headers = (WinNT.IMAGE_NT_HEADERS64 *)memory_module->headers;
numberOfSections = new_headers->FileHeader.NumberOfSections;
WinNT.IMAGE_NT_HEADERS64 *old_headers = (WinNT.IMAGE_NT_HEADERS64 *)ptr_old_headers;
sectionAlignment = old_headers->OptionalHeader.SectionAlignment;
}
else
{
WinNT.IMAGE_NT_HEADERS32 *new_headers = (WinNT.IMAGE_NT_HEADERS32 *)memory_module->headers;
numberOfSections = new_headers->FileHeader.NumberOfSections;
WinNT.IMAGE_NT_HEADERS32 *old_headers = (WinNT.IMAGE_NT_HEADERS32 *)ptr_old_headers;
sectionAlignment = old_headers->OptionalHeader.SectionAlignment;
}
uint index;
byte *dest;
for (index = 0; index < numberOfSections; index++, section++)
{
if (section->SizeOfRawData == 0)
{
if (sectionAlignment > 0)
{
dest = (byte *)WinBase.VirtualAlloc((IntPtr)(codeBase + section->VirtualAddress), sectionAlignment, WinNT.MEM_COMMIT, WinNT.PAGE_READWRITE);
section->PhysicalAddress = (uint)dest;
memory.memset(dest, 0, sectionAlignment);
}
continue;
}
// commit memory block and copy data from dll
dest = (byte *)WinBase.VirtualAlloc((IntPtr)(codeBase + section->VirtualAddress), section->SizeOfRawData, WinNT.MEM_COMMIT, WinNT.PAGE_READWRITE);
memory.memcpy(dest, ptr_data + section->PointerToRawData, section->SizeOfRawData);
section->PhysicalAddress = (uint)dest;
}
}
/// <summary>
/// Marks memory pages depending on section headers and release sections that are marked as "discardable".
/// </summary>
/// <param name="memory_module">Pointer to a memory module.</param>
private void FinalizeSections(MEMORY_MODULE *memory_module)
{
WinNT.IMAGE_SECTION_HEADER *section = WinNT.IMAGE_FIRST_SECTION(memory_module->headers);;
ushort number_of_sections;
uint size_of_initialized_data;
uint size_of_uninitialized_data;
long image_offset = 0;
if (Environment.Is64BitProcess)
{
WinNT.IMAGE_NT_HEADERS64 *headers = (WinNT.IMAGE_NT_HEADERS64 *)memory_module->headers;
number_of_sections = headers->FileHeader.NumberOfSections;
size_of_initialized_data = headers->OptionalHeader.SizeOfInitializedData;
size_of_uninitialized_data = headers->OptionalHeader.SizeOfUninitializedData;
image_offset = (long)((ulong)headers->OptionalHeader.ImageBase & 0xffffffff00000000);
}
else
{
WinNT.IMAGE_NT_HEADERS32 *headers = (WinNT.IMAGE_NT_HEADERS32 *)memory_module->headers;
number_of_sections = headers->FileHeader.NumberOfSections;
size_of_initialized_data = headers->OptionalHeader.SizeOfInitializedData;
size_of_uninitialized_data = headers->OptionalHeader.SizeOfUninitializedData;
}
for (int i = 0; i < number_of_sections; i++, section++)
{
uint protect, oldProtect, rawDataSize;
uint executable = Convert.ToUInt32((section->Characteristics & WinNT.IMAGE_SCN_MEM_EXECUTE) != 0);
uint readable = Convert.ToUInt32((section->Characteristics & WinNT.IMAGE_SCN_MEM_READ) != 0);
uint writeable = Convert.ToUInt32((section->Characteristics & WinNT.IMAGE_SCN_MEM_WRITE) != 0);
if ((section->Characteristics & WinNT.IMAGE_SCN_MEM_DISCARDABLE) != 0)
{
// section is not needed any more and can safely be freed
WinBase.VirtualFree((IntPtr)(void *)((long)section->PhysicalAddress | (long)image_offset), section->SizeOfRawData, WinNT.MEM_DECOMMIT);
continue;
}
protect = _protectionFlags[executable, readable, writeable];
if ((section->Characteristics & WinNT.IMAGE_SCN_MEM_NOT_CACHED) != 0)
{
protect |= WinNT.PAGE_NOCACHE;
}
// determine size of region
rawDataSize = section->SizeOfRawData;
if (rawDataSize == 0)
{
if ((section->Characteristics & WinNT.IMAGE_SCN_CNT_INITIALIZED_DATA) != 0)
{
rawDataSize = size_of_initialized_data;
}
else if ((section->Characteristics & WinNT.IMAGE_SCN_CNT_UNINITIALIZED_DATA) != 0)
{
rawDataSize = size_of_uninitialized_data;
}
}
if (rawDataSize > 0)
{
// change memory access flags
WinBase.VirtualProtect((IntPtr)(void *)((long)section->PhysicalAddress | (long)image_offset), rawDataSize, protect, &oldProtect);
}
}
}