static bool PerformBaseRelocation(ref IMAGE_NT_HEADERS OrgNTHeaders, IntPtr pCode, IntPtr delta)
{
if (OrgNTHeaders.OptionalHeader.BaseRelocationTable.Size == 0)
{
return(delta == IntPtr.Zero);
}
for (IntPtr pRelocation = PtrAdd(pCode, OrgNTHeaders.OptionalHeader.BaseRelocationTable.VirtualAddress);;)
{
IMAGE_BASE_RELOCATION Relocation = PtrRead <IMAGE_BASE_RELOCATION>(pRelocation);
if (Relocation.VirtualAdress == 0)
{
break;
}
IntPtr pDest = PtrAdd(pCode, Relocation.VirtualAdress);
IntPtr pRelInfo = PtrAdd(pRelocation, Sz.IMAGE_BASE_RELOCATION);
uint RelCount = ((Relocation.SizeOfBlock - Sz.IMAGE_BASE_RELOCATION) / 2);
for (uint i = 0; i != RelCount; i++, pRelInfo = PtrAdd(pRelInfo, sizeof(ushort)))
{
ushort relInfo = (ushort)Marshal.PtrToStructure(pRelInfo, typeof(ushort));
BasedRelocationType type = (BasedRelocationType)(relInfo >> 12); // the upper 4 bits define the type of relocation
int offset = (relInfo & 0xfff); // the lower 12 bits define the offset
IntPtr pPatchAddr = PtrAdd(pDest, offset);
switch (type)
{
case BasedRelocationType.IMAGE_REL_BASED_ABSOLUTE:
// skip relocation
break;
case BasedRelocationType.IMAGE_REL_BASED_HIGHLOW:
// change complete 32 bit address
int patchAddrHL = (int)Marshal.PtrToStructure(pPatchAddr, typeof(int));
patchAddrHL += (int)delta;
Marshal.StructureToPtr(patchAddrHL, pPatchAddr, false);
break;
case BasedRelocationType.IMAGE_REL_BASED_DIR64:
long patchAddr64 = (long)Marshal.PtrToStructure(pPatchAddr, typeof(long));
patchAddr64 += (long)delta;
Marshal.StructureToPtr(patchAddr64, pPatchAddr, false);
break;
}
}
// advance to next relocation block
pRelocation = PtrAdd(pRelocation, Relocation.SizeOfBlock);
}
return(true);
}
private bool PerformBaseRelocation(PtrDiffT delta)
{
int imageSizeOfBaseRelocation = Marshal.SizeOf(typeof(IMAGE_BASE_RELOCATION));
IMAGE_DATA_DIRECTORY *directory = &_headers->OptionalHeader.BaseRelocationTable;
if (directory->Size == 0)
{
return(delta == 0);
}
if (directory->Size > 0)
{
IMAGE_BASE_RELOCATION *relocation = (IMAGE_BASE_RELOCATION *)(_codeBase + directory->VirtualAddress);
while (relocation->VirtualAdress > 0)
{
byte * dest = _codeBase + relocation->VirtualAdress;
ushort *relInfo = (ushort *)((byte *)relocation + imageSizeOfBaseRelocation);
for (int i = 0; i < ((relocation->SizeOfBlock - imageSizeOfBaseRelocation) / 2); i++, relInfo++)
{
// the upper 4 bits define the type of relocation
BasedRelocationType type = (BasedRelocationType)(*relInfo >> 12);
// the lower 12 bits define the offset
int offset = *relInfo & 0xfff;
switch (type)
{
case BasedRelocationType.IMAGE_REL_BASED_ABSOLUTE:
break;
case BasedRelocationType.IMAGE_REL_BASED_HIGHLOW:
uint *patchAddrHL = (uint *)(dest + offset);
* patchAddrHL += (uint)delta;
break;
case BasedRelocationType.IMAGE_REL_BASED_DIR64:
ulong *patchAddr64 = (ulong *)(dest + offset);
* patchAddr64 += (ulong)delta;
break;
default:
break;
}
}
// advance to next relocation block
relocation = (IMAGE_BASE_RELOCATION *)(((byte *)relocation) + relocation->SizeOfBlock);
}
}
return(true);
}
