struct Hook {
DWORD addr = NULL;
byte* data = nullptr;
size_t size = NULL;
DWORD trampoline = NULL;
size_t addBytesSize = NULL;
Hook(const DWORD& addr, const DWORD& func, const char* addBytes, const size_t &addBytesSize, const size_t& size = 5) { // addBytes для пуша аргументов функции func
this->data = new byte[size];
this->size = size;
this->addr = addr;
this->addBytesSize = addBytesSize;
DWORD dwProt = PAGE_EXECUTE_READWRITE;
VirtualProtect((void*)addr, size, dwProt, &dwProt);
memcpy(data, (void*)addr, size);
trampoline = (DWORD)VirtualAlloc(0, addBytesSize + size + 12, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); // pushad / addBytes / call func / popad / замененные байты / джамп назад
*(byte*)trampoline = 0x60; // pushad
memcpy((void *)(trampoline + 1), addBytes, addBytesSize); // addBytes
*(byte*)(trampoline + addBytesSize + 1) = 0xE8; //call
*(size_t*)(trampoline + addBytesSize + 2) = func - (trampoline + addBytesSize + 6); // func
*(byte*)(trampoline + addBytesSize + 6) = 0x61; // popad
memcpy((void*)(trampoline + addBytesSize + 7), data, size); // замененные байты
*(byte*)(trampoline + addBytesSize + size + 7) = 0xE9; // jmp
*(size_t*)(trampoline + addBytesSize + size + 8) = addr + 5 - (trampoline + addBytesSize + size + 12); // jmp to
memset((void*)(addr + 4), 0x90, size-4);
*(byte*)(addr) = 0xE9; // jmp
*(unsigned int*)(addr + 1) = trampoline - (addr + 5);
VirtualProtect((void*)addr, size, dwProt, NULL);
}
~Hook() {
if (data != nullptr) {
DWORD dwProt = PAGE_EXECUTE_READWRITE;
VirtualProtect((void*)addr, size, dwProt, &dwProt);
memcpy((void*)addr, data, size);
VirtualProtect((void*)addr, size, dwProt, NULL);
memset((void*)trampoline, NULL, addBytesSize + size + 12);
VirtualFree((void*)trampoline, addBytesSize + size + 12, MEM_RELEASE);
delete[] data;
}
}
};
