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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef __GNUC__
// disable warnings about pointer <-> DWORD conversions
# pragma warning(disable : 4311 4312)
#endif
#ifdef _WIN64
# define POINTER_TYPE ULONGLONG
#else
# define POINTER_TYPE DWORD
#endif
#include <windows.h>
#include <winnt.h>
#include <stdlib.h>
#ifdef DEBUG_OUTPUT
# include <stdio.h>
#endif
#include "nsWindowsHelpers.h"
typedef const unsigned char* FileView;
template <>
class nsAutoRefTraits<FileView> {
public:
typedef FileView RawRef;
static FileView Void() { return nullptr; }
static void Release(RawRef aView) {
if (nullptr != aView) UnmapViewOfFile(aView);
}
};
#ifndef IMAGE_SIZEOF_BASE_RELOCATION
// Vista SDKs no longer define IMAGE_SIZEOF_BASE_RELOCATION!?
# define IMAGE_SIZEOF_BASE_RELOCATION (sizeof(IMAGE_BASE_RELOCATION))
#endif
#include "LoadLibraryRemote.h"
typedef struct {
PIMAGE_NT_HEADERS headers;
unsigned char* localCodeBase;
unsigned char* remoteCodeBase;
HMODULE* modules;
int numModules;
} MEMORYMODULE, *PMEMORYMODULE;
typedef BOOL(WINAPI* DllEntryProc)(HINSTANCE hinstDLL, DWORD fdwReason,
LPVOID lpReserved);
#define GET_HEADER_DICTIONARY(module, idx) \
&(module)->headers->OptionalHeader.DataDirectory[idx]
#ifdef DEBUG_OUTPUT
static void OutputLastError(const char* msg) {
char* tmp;
char* tmpmsg;
FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
nullptr, GetLastError(),
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&tmp, 0,
nullptr);
tmpmsg = (char*)LocalAlloc(LPTR, strlen(msg) + strlen(tmp) + 3);
sprintf(tmpmsg, "%s: %s", msg, tmp);
OutputDebugStringA(tmpmsg);
LocalFree(tmpmsg);
LocalFree(tmp);
}
#endif
static void CopySections(const unsigned char* data,
PIMAGE_NT_HEADERS old_headers, PMEMORYMODULE module) {
int i;
unsigned char* codeBase = module->localCodeBase;
unsigned char* dest;
PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
for (i = 0; i < module->headers->FileHeader.NumberOfSections;
i++, section++) {
dest = codeBase + section->VirtualAddress;
memset(dest, 0, section->Misc.VirtualSize);
if (section->SizeOfRawData) {
memcpy(dest, data + section->PointerToRawData, section->SizeOfRawData);
}
// section->Misc.PhysicalAddress = (POINTER_TYPE) module->remoteCodeBase +
// section->VirtualAddress;
}
}
static bool CopyRegion(HANDLE hRemoteProcess, void* remoteAddress,
void* localAddress, DWORD size, DWORD protect) {
if (size > 0) {
// Copy the data from local->remote and set the memory protection
if (!VirtualAllocEx(hRemoteProcess, remoteAddress, size, MEM_COMMIT,
PAGE_READWRITE))
return false;
if (!WriteProcessMemory(hRemoteProcess, remoteAddress, localAddress, size,
nullptr)) {
#ifdef DEBUG_OUTPUT
OutputLastError("Error writing remote memory.\n");
#endif
return false;
}
DWORD oldProtect;
if (VirtualProtectEx(hRemoteProcess, remoteAddress, size, protect,
&oldProtect) == 0) {
#ifdef DEBUG_OUTPUT
OutputLastError("Error protecting memory page");
#endif
return false;
}
}
return true;
}
// Protection flags for memory pages (Executable, Readable, Writeable)
static int ProtectionFlags[2][2][2] = {
{
// not executable
{PAGE_NOACCESS, PAGE_WRITECOPY},
{PAGE_READONLY, PAGE_READWRITE},
},
{
// executable
{PAGE_EXECUTE, PAGE_EXECUTE_WRITECOPY},
{PAGE_EXECUTE_READ, PAGE_EXECUTE_READWRITE},
},
};
static bool FinalizeSections(PMEMORYMODULE module, HANDLE hRemoteProcess) {
#ifdef DEBUG_OUTPUT
fprintf(stderr, "Finalizing sections: local base %p, remote base %p\n",
module->localCodeBase, module->remoteCodeBase);
#endif
int i;
int numSections = module->headers->FileHeader.NumberOfSections;
if (numSections < 1) return false;
PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
// Copy any data before the first section (i.e. the image header)
if (!CopyRegion(hRemoteProcess, module->remoteCodeBase, module->localCodeBase,
section->VirtualAddress, PAGE_READONLY))
return false;
// loop through all sections and change access flags
for (i = 0; i < numSections; i++, section++) {
DWORD protect, 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;
// determine protection flags based on characteristics
protect = ProtectionFlags[executable][readable][writeable];
if (section->Characteristics & IMAGE_SCN_MEM_NOT_CACHED) {
protect |= PAGE_NOCACHE;
}
void* remoteAddress = module->remoteCodeBase + section->VirtualAddress;
void* localAddress = module->localCodeBase + section->VirtualAddress;
// determine size of region
size = section->Misc.VirtualSize;
#ifdef DEBUG_OUTPUT
fprintf(stderr,
"Copying section %s to %p, size %x, executable %i readable %i "
"writeable %i\n",
section->Name, remoteAddress, size, executable, readable,
writeable);
#endif
if (!CopyRegion(hRemoteProcess, remoteAddress, localAddress, size, protect))
return false;
}
return true;
}
static void PerformBaseRelocation(PMEMORYMODULE module, SIZE_T delta) {
DWORD i;
unsigned char* codeBase = module->localCodeBase;
PIMAGE_DATA_DIRECTORY directory =
GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_BASERELOC);
if (directory->Size > 0) {
PIMAGE_BASE_RELOCATION relocation =
(PIMAGE_BASE_RELOCATION)(codeBase + directory->VirtualAddress);
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++) {
DWORD* patchAddrHL;
#ifdef _WIN64
ULONGLONG* patchAddr64;
#endif
int type, offset;
// the upper 4 bits define the type of relocation
type = *relInfo >> 12;
// the lower 12 bits define the offset
offset = *relInfo & 0xfff;
switch (type) {
case IMAGE_REL_BASED_ABSOLUTE:
// skip relocation
break;
case IMAGE_REL_BASED_HIGHLOW:
// change complete 32 bit address
patchAddrHL = (DWORD*)(dest + offset);
*patchAddrHL += delta;
break;
#ifdef _WIN64
case IMAGE_REL_BASED_DIR64:
patchAddr64 = (ULONGLONG*)(dest + offset);
*patchAddr64 += delta;
break;
#endif
default:
// printf("Unknown relocation: %d\n", type);
break;
}
}
// advance to next relocation block
relocation = (PIMAGE_BASE_RELOCATION)(((char*)relocation) +
relocation->SizeOfBlock);
}
}
}
static int BuildImportTable(PMEMORYMODULE module) {
int result = 1;
unsigned char* codeBase = module->localCodeBase;
PIMAGE_DATA_DIRECTORY directory =
GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_IMPORT);
if (directory->Size > 0) {
PIMAGE_IMPORT_DESCRIPTOR importDesc =
(PIMAGE_IMPORT_DESCRIPTOR)(codeBase + directory->VirtualAddress);
PIMAGE_IMPORT_DESCRIPTOR importEnd =
(PIMAGE_IMPORT_DESCRIPTOR)(codeBase + directory->VirtualAddress +
directory->Size);
for (; importDesc < importEnd && importDesc->Name; importDesc++) {
POINTER_TYPE* thunkRef;
FARPROC* funcRef;
HMODULE handle = GetModuleHandleA((LPCSTR)(codeBase + importDesc->Name));
if (handle == nullptr) {
#if DEBUG_OUTPUT
OutputLastError("Can't load library");
#endif
result = 0;
break;
}
module->modules = (HMODULE*)realloc(
module->modules, (module->numModules + 1) * (sizeof(HMODULE)));
if (module->modules == nullptr) {
result = 0;
break;
}
module->modules[module->numModules++] = handle;
if (importDesc->OriginalFirstThunk) {
thunkRef = (POINTER_TYPE*)(codeBase + importDesc->OriginalFirstThunk);
funcRef = (FARPROC*)(codeBase + importDesc->FirstThunk);
} else {
// no hint table
thunkRef = (POINTER_TYPE*)(codeBase + importDesc->FirstThunk);
funcRef = (FARPROC*)(codeBase + importDesc->FirstThunk);
}
for (; *thunkRef; thunkRef++, funcRef++) {
if (IMAGE_SNAP_BY_ORDINAL(*thunkRef)) {
*funcRef =
(FARPROC)GetProcAddress(handle, (LPCSTR)IMAGE_ORDINAL(*thunkRef));
} else {
PIMAGE_IMPORT_BY_NAME thunkData =
(PIMAGE_IMPORT_BY_NAME)(codeBase + (*thunkRef));
*funcRef = (FARPROC)GetProcAddress(handle, (LPCSTR)&thunkData->Name);
}
if (*funcRef == 0) {
result = 0;
break;
}
}
if (!result) {
break;
}
}
}
return result;
}
static void* MemoryGetProcAddress(PMEMORYMODULE module, const char* name);
void* LoadRemoteLibraryAndGetAddress(HANDLE hRemoteProcess,
const WCHAR* library, const char* symbol) {
// Map the DLL into memory
nsAutoHandle hLibrary(CreateFile(library, GENERIC_READ, FILE_SHARE_READ,
nullptr, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL, nullptr));
if (INVALID_HANDLE_VALUE == hLibrary) {
#if DEBUG_OUTPUT
OutputLastError("Couldn't CreateFile the library.\n");
#endif
return nullptr;
}
nsAutoHandle hMapping(
CreateFileMapping(hLibrary, nullptr, PAGE_READONLY, 0, 0, nullptr));
if (!hMapping) {
#if DEBUG_OUTPUT
OutputLastError("Couldn't CreateFileMapping.\n");
#endif
return nullptr;
}
nsAutoRef<FileView> data(
(const unsigned char*)MapViewOfFile(hMapping, FILE_MAP_READ, 0, 0, 0));
if (!data) {
#if DEBUG_OUTPUT
OutputLastError("Couldn't MapViewOfFile.\n");
#endif
return nullptr;
}
SIZE_T locationDelta;
PIMAGE_DOS_HEADER dos_header = (PIMAGE_DOS_HEADER)data.get();
if (dos_header->e_magic != IMAGE_DOS_SIGNATURE) {
#if DEBUG_OUTPUT
OutputDebugStringA("Not a valid executable file.\n");
#endif
return nullptr;
}
PIMAGE_NT_HEADERS old_header =
(PIMAGE_NT_HEADERS)(data + dos_header->e_lfanew);
if (old_header->Signature != IMAGE_NT_SIGNATURE) {
#if DEBUG_OUTPUT
OutputDebugStringA("No PE header found.\n");
#endif
return nullptr;
}
// reserve memory for image of library in this process and the target process
unsigned char* localCode = (unsigned char*)VirtualAlloc(
nullptr, old_header->OptionalHeader.SizeOfImage, MEM_RESERVE | MEM_COMMIT,
PAGE_READWRITE);
if (!localCode) {
#if DEBUG_OUTPUT
OutputLastError("Can't reserve local memory.");
#endif
}
unsigned char* remoteCode = (unsigned char*)VirtualAllocEx(
hRemoteProcess, nullptr, old_header->OptionalHeader.SizeOfImage,
MEM_RESERVE, PAGE_EXECUTE_READ);
if (!remoteCode) {
#if DEBUG_OUTPUT
OutputLastError("Can't reserve remote memory.");
#endif
}
MEMORYMODULE result;
result.localCodeBase = localCode;
result.remoteCodeBase = remoteCode;
result.numModules = 0;
result.modules = nullptr;
// copy PE header to code
memcpy(localCode, dos_header,
dos_header->e_lfanew + old_header->OptionalHeader.SizeOfHeaders);
result.headers =
reinterpret_cast<PIMAGE_NT_HEADERS>(localCode + dos_header->e_lfanew);
// update position
result.headers->OptionalHeader.ImageBase = (POINTER_TYPE)remoteCode;
// copy sections from DLL file block to new memory location
CopySections(data, old_header, &result);
// adjust base address of imported data
locationDelta = (SIZE_T)(remoteCode - old_header->OptionalHeader.ImageBase);
if (locationDelta != 0) {
PerformBaseRelocation(&result, locationDelta);
}
// load required dlls and adjust function table of imports
if (!BuildImportTable(&result)) {
return nullptr;
}
// mark memory pages depending on section headers and release
// sections that are marked as "discardable"
if (!FinalizeSections(&result, hRemoteProcess)) {
return nullptr;
}
return MemoryGetProcAddress(&result, symbol);
}
static void* MemoryGetProcAddress(PMEMORYMODULE module, const char* name) {
unsigned char* localCodeBase = module->localCodeBase;
int idx = -1;
DWORD i, *nameRef;
WORD* ordinal;
PIMAGE_EXPORT_DIRECTORY exports;
PIMAGE_DATA_DIRECTORY directory =
GET_HEADER_DICTIONARY(module, IMAGE_DIRECTORY_ENTRY_EXPORT);
if (directory->Size == 0) {
// no export table found
return nullptr;
}
exports =
(PIMAGE_EXPORT_DIRECTORY)(localCodeBase + directory->VirtualAddress);
if (exports->NumberOfNames == 0 || exports->NumberOfFunctions == 0) {
// DLL doesn't export anything
return nullptr;
}
// search function name in list of exported names
nameRef = (DWORD*)(localCodeBase + exports->AddressOfNames);
ordinal = (WORD*)(localCodeBase + exports->AddressOfNameOrdinals);
for (i = 0; i < exports->NumberOfNames; i++, nameRef++, ordinal++) {
if (stricmp(name, (const char*)(localCodeBase + (*nameRef))) == 0) {
idx = *ordinal;
break;
}
}
if (idx == -1) {
// exported symbol not found
return nullptr;
}
if ((DWORD)idx > exports->NumberOfFunctions) {
// name <-> ordinal number don't match
return nullptr;
}
// AddressOfFunctions contains the RVAs to the "real" functions
return module->remoteCodeBase +
(*(DWORD*)(localCodeBase + exports->AddressOfFunctions + (idx * 4)));
}