updated code layout

This commit is contained in:
Joachim Bauch
2010-10-24 22:17:57 +02:00
parent b0e63038e2
commit 178ea7363c
+61 -75
View File
@@ -78,15 +78,12 @@ CopySections(const unsigned char *data, PIMAGE_NT_HEADERS old_headers, PMEMORYMO
unsigned char *codeBase = module->codeBase;
unsigned char *dest;
PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++)
{
if (section->SizeOfRawData == 0)
{
for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
if (section->SizeOfRawData == 0) {
// section doesn't contain data in the dll itself, but may define
// uninitialized data
size = old_headers->OptionalHeader.SectionAlignment;
if (size > 0)
{
if (size > 0) {
dest = (unsigned char *)VirtualAlloc(codeBase + section->VirtualAddress,
size,
MEM_COMMIT,
@@ -135,15 +132,13 @@ FinalizeSections(PMEMORYMODULE module)
#endif
// loop through all sections and change access flags
for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++)
{
for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
DWORD protect, oldProtect, size;
int executable = (section->Characteristics & IMAGE_SCN_MEM_EXECUTE) != 0;
int readable = (section->Characteristics & IMAGE_SCN_MEM_READ) != 0;
int writeable = (section->Characteristics & IMAGE_SCN_MEM_WRITE) != 0;
if (section->Characteristics & IMAGE_SCN_MEM_DISCARDABLE)
{
if (section->Characteristics & IMAGE_SCN_MEM_DISCARDABLE) {
// section is not needed any more and can safely be freed
VirtualFree((LPVOID)((POINTER_TYPE)section->Misc.PhysicalAddress | imageOffset), section->SizeOfRawData, MEM_DECOMMIT);
continue;
@@ -151,21 +146,21 @@ FinalizeSections(PMEMORYMODULE module)
// determine protection flags based on characteristics
protect = ProtectionFlags[executable][readable][writeable];
if (section->Characteristics & IMAGE_SCN_MEM_NOT_CACHED)
if (section->Characteristics & IMAGE_SCN_MEM_NOT_CACHED) {
protect |= PAGE_NOCACHE;
}
// determine size of region
size = section->SizeOfRawData;
if (size == 0)
{
if (section->Characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA)
if (size == 0) {
if (section->Characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA) {
size = module->headers->OptionalHeader.SizeOfInitializedData;
else if (section->Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
} else if (section->Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA) {
size = module->headers->OptionalHeader.SizeOfUninitializedData;
}
}
if (size > 0)
{
if (size > 0) {
// change memory access flags
if (VirtualProtect((LPVOID)((POINTER_TYPE)section->Misc.PhysicalAddress | imageOffset), section->SizeOfRawData, protect, &oldProtect) == 0)
#ifdef DEBUG_OUTPUT
@@ -186,15 +181,12 @@ PerformBaseRelocation(PMEMORYMODULE module, SIZE_T delta)
unsigned char *codeBase = module->codeBase;
PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_BASERELOC);
if (directory->Size > 0)
{
if (directory->Size > 0) {
PIMAGE_BASE_RELOCATION relocation = (PIMAGE_BASE_RELOCATION) (codeBase + directory->VirtualAddress);
for (; relocation->VirtualAddress > 0; )
{
for (; relocation->VirtualAddress > 0; ) {
unsigned char *dest = codeBase + relocation->VirtualAddress;
unsigned short *relInfo = (unsigned short *)((unsigned char *)relocation + IMAGE_SIZEOF_BASE_RELOCATION);
for (i=0; i<((relocation->SizeOfBlock-IMAGE_SIZEOF_BASE_RELOCATION) / 2); i++, relInfo++)
{
for (i=0; i<((relocation->SizeOfBlock-IMAGE_SIZEOF_BASE_RELOCATION) / 2); i++, relInfo++) {
DWORD *patchAddrHL;
#ifdef _WIN64
ULONGLONG *patchAddr64;
@@ -244,16 +236,13 @@ BuildImportTable(PMEMORYMODULE module)
unsigned char *codeBase = module->codeBase;
PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_IMPORT);
if (directory->Size > 0)
{
if (directory->Size > 0) {
PIMAGE_IMPORT_DESCRIPTOR importDesc = (PIMAGE_IMPORT_DESCRIPTOR) (codeBase + directory->VirtualAddress);
for (; !IsBadReadPtr(importDesc, sizeof(IMAGE_IMPORT_DESCRIPTOR)) && importDesc->Name; importDesc++)
{
for (; !IsBadReadPtr(importDesc, sizeof(IMAGE_IMPORT_DESCRIPTOR)) && importDesc->Name; importDesc++) {
POINTER_TYPE *thunkRef;
FARPROC *funcRef;
HMODULE handle = LoadLibrary((LPCSTR) (codeBase + importDesc->Name));
if (handle == INVALID_HANDLE_VALUE)
{
if (handle == INVALID_HANDLE_VALUE) {
#if DEBUG_OUTPUT
OutputLastError("Can't load library");
#endif
@@ -262,15 +251,13 @@ BuildImportTable(PMEMORYMODULE module)
}
module->modules = (HMODULE *)realloc(module->modules, (module->numModules+1)*(sizeof(HMODULE)));
if (module->modules == NULL)
{
if (module->modules == NULL) {
result = 0;
break;
}
module->modules[module->numModules++] = handle;
if (importDesc->OriginalFirstThunk)
{
if (importDesc->OriginalFirstThunk) {
thunkRef = (POINTER_TYPE *) (codeBase + importDesc->OriginalFirstThunk);
funcRef = (FARPROC *) (codeBase + importDesc->FirstThunk);
} else {
@@ -278,23 +265,22 @@ BuildImportTable(PMEMORYMODULE module)
thunkRef = (POINTER_TYPE *) (codeBase + importDesc->FirstThunk);
funcRef = (FARPROC *) (codeBase + importDesc->FirstThunk);
}
for (; *thunkRef; thunkRef++, funcRef++)
{
if IMAGE_SNAP_BY_ORDINAL(*thunkRef)
for (; *thunkRef; thunkRef++, funcRef++) {
if (IMAGE_SNAP_BY_ORDINAL(*thunkRef)) {
*funcRef = (FARPROC)GetProcAddress(handle, (LPCSTR)IMAGE_ORDINAL(*thunkRef));
else {
} else {
PIMAGE_IMPORT_BY_NAME thunkData = (PIMAGE_IMPORT_BY_NAME) (codeBase + (*thunkRef));
*funcRef = (FARPROC)GetProcAddress(handle, (LPCSTR)&thunkData->Name);
}
if (*funcRef == 0)
{
if (*funcRef == 0) {
result = 0;
break;
}
}
if (!result)
if (!result) {
break;
}
}
}
@@ -312,8 +298,7 @@ HMEMORYMODULE MemoryLoadLibrary(const void *data)
BOOL successfull;
dos_header = (PIMAGE_DOS_HEADER)data;
if (dos_header->e_magic != IMAGE_DOS_SIGNATURE)
{
if (dos_header->e_magic != IMAGE_DOS_SIGNATURE) {
#if DEBUG_OUTPUT
OutputDebugString("Not a valid executable file.\n");
#endif
@@ -321,8 +306,7 @@ HMEMORYMODULE MemoryLoadLibrary(const void *data)
}
old_header = (PIMAGE_NT_HEADERS)&((const unsigned char *)(data))[dos_header->e_lfanew];
if (old_header->Signature != IMAGE_NT_SIGNATURE)
{
if (old_header->Signature != IMAGE_NT_SIGNATURE) {
#if DEBUG_OUTPUT
OutputDebugString("No PE header found.\n");
#endif
@@ -335,21 +319,20 @@ HMEMORYMODULE MemoryLoadLibrary(const void *data)
MEM_RESERVE,
PAGE_READWRITE);
if (code == NULL)
if (code == NULL) {
// try to allocate memory at arbitrary position
code = (unsigned char *)VirtualAlloc(NULL,
old_header->OptionalHeader.SizeOfImage,
MEM_RESERVE,
PAGE_READWRITE);
if (code == NULL)
{
if (code == NULL) {
#if DEBUG_OUTPUT
OutputLastError("Can't reserve memory");
OutputLastError("Can't reserve memory");
#endif
return NULL;
return NULL;
}
}
result = (PMEMORYMODULE)HeapAlloc(GetProcessHeap(), 0, sizeof(MEMORYMODULE));
result->codeBase = code;
result->numModules = 0;
@@ -381,23 +364,23 @@ HMEMORYMODULE MemoryLoadLibrary(const void *data)
// adjust base address of imported data
locationDelta = (SIZE_T)(code - old_header->OptionalHeader.ImageBase);
if (locationDelta != 0)
if (locationDelta != 0) {
PerformBaseRelocation(result, locationDelta);
}
// load required dlls and adjust function table of imports
if (!BuildImportTable(result))
if (!BuildImportTable(result)) {
goto error;
}
// mark memory pages depending on section headers and release
// sections that are marked as "discardable"
FinalizeSections(result);
// get entry point of loaded library
if (result->headers->OptionalHeader.AddressOfEntryPoint != 0)
{
if (result->headers->OptionalHeader.AddressOfEntryPoint != 0) {
DllEntry = (DllEntryProc) (code + result->headers->OptionalHeader.AddressOfEntryPoint);
if (DllEntry == 0)
{
if (DllEntry == 0) {
#if DEBUG_OUTPUT
OutputDebugString("Library has no entry point.\n");
#endif
@@ -406,8 +389,7 @@ HMEMORYMODULE MemoryLoadLibrary(const void *data)
// notify library about attaching to process
successfull = (*DllEntry)((HINSTANCE)code, DLL_PROCESS_ATTACH, 0);
if (!successfull)
{
if (!successfull) {
#if DEBUG_OUTPUT
OutputDebugString("Can't attach library.\n");
#endif
@@ -432,32 +414,36 @@ FARPROC MemoryGetProcAddress(HMEMORYMODULE module, const char *name)
WORD *ordinal;
PIMAGE_EXPORT_DIRECTORY exports;
PIMAGE_DATA_DIRECTORY directory = GET_HEADER_DICTIONARY((PMEMORYMODULE)module, IMAGE_DIRECTORY_ENTRY_EXPORT);
if (directory->Size == 0)
if (directory->Size == 0) {
// no export table found
return NULL;
}
exports = (PIMAGE_EXPORT_DIRECTORY) (codeBase + directory->VirtualAddress);
if (exports->NumberOfNames == 0 || exports->NumberOfFunctions == 0)
if (exports->NumberOfNames == 0 || exports->NumberOfFunctions == 0) {
// DLL doesn't export anything
return NULL;
}
// search function name in list of exported names
nameRef = (DWORD *) (codeBase + exports->AddressOfNames);
ordinal = (WORD *) (codeBase + exports->AddressOfNameOrdinals);
for (i=0; i<exports->NumberOfNames; i++, nameRef++, ordinal++)
if (stricmp(name, (const char *) (codeBase + (*nameRef))) == 0)
{
for (i=0; i<exports->NumberOfNames; i++, nameRef++, ordinal++) {
if (stricmp(name, (const char *) (codeBase + (*nameRef))) == 0) {
idx = *ordinal;
break;
}
}
if (idx == -1)
if (idx == -1) {
// exported symbol not found
return NULL;
}
if ((DWORD)idx > exports->NumberOfFunctions)
if ((DWORD)idx > exports->NumberOfFunctions) {
// name <-> ordinal number don't match
return NULL;
}
// AddressOfFunctions contains the RVAs to the "real" functions
return (FARPROC) (codeBase + (*(DWORD *) (codeBase + exports->AddressOfFunctions + (idx*4))));
@@ -468,29 +454,29 @@ void MemoryFreeLibrary(HMEMORYMODULE mod)
int i;
PMEMORYMODULE module = (PMEMORYMODULE)mod;
if (module != NULL)
{
if (module->initialized != 0)
{
if (module != NULL) {
if (module->initialized != 0) {
// notify library about detaching from process
DllEntryProc DllEntry = (DllEntryProc) (module->codeBase + module->headers->OptionalHeader.AddressOfEntryPoint);
(*DllEntry)((HINSTANCE)module->codeBase, DLL_PROCESS_DETACH, 0);
module->initialized = 0;
}
if (module->modules != NULL)
{
if (module->modules != NULL) {
// free previously opened libraries
for (i=0; i<module->numModules; i++)
if (module->modules[i] != INVALID_HANDLE_VALUE)
for (i=0; i<module->numModules; i++) {
if (module->modules[i] != INVALID_HANDLE_VALUE) {
FreeLibrary(module->modules[i]);
}
}
free(module->modules);
}
if (module->codeBase != NULL)
if (module->codeBase != NULL) {
// release memory of library
VirtualFree(module->codeBase, 0, MEM_RELEASE);
}
HeapFree(GetProcessHeap(), 0, module);
}