BlackOpsPlugin/src/common/utils/hook.cpp

#include "hook.hpp"
#include "string.hpp"

#include <MinHook.h>

namespace utils::hook {
namespace {
[[maybe_unused]] class _ {
public:
  _() {
    if (MH_Initialize() != MH_OK) {
      throw std::runtime_error("Failed to initialize MinHook");
    }
  }

  ~_() { MH_Uninitialize(); }
} __;
} // namespace

asmjit::Error assembler::call(void* target) {
  return Assembler::call(size_t(target));
}

asmjit::Error assembler::jmp(void* target) {
  return Assembler::jmp(size_t(target));
}

detour::detour(const size_t place, void* target)
    : detour(reinterpret_cast<void*>(place), target) {}

detour::detour(void* place, void* target) { this->create(place, target); }

detour::~detour() { this->clear(); }

void detour::enable() const { MH_EnableHook(this->place_); }

void detour::disable() const { MH_DisableHook(this->place_); }

void detour::create(void* place, void* target) {
  this->clear();
  this->place_ = place;

  if (MH_CreateHook(this->place_, target, &this->original_) != MH_OK) {
    throw std::runtime_error(
        string::va("Unable to create hook at location: %p", this->place_));
  }

  this->enable();
}

void detour::create(const size_t place, void* target) {
  this->create(reinterpret_cast<void*>(place), target);
}

void detour::clear() {
  if (this->place_) {
    MH_RemoveHook(this->place_);
  }

  this->place_ = nullptr;
  this->original_ = nullptr;
}

void* detour::get_original() const { return this->original_; }

void nop(void* place, const size_t length) {
  DWORD old_protect{};
  VirtualProtect(place, length, PAGE_EXECUTE_READWRITE, &old_protect);

  std::memset(place, 0x90, length);

  VirtualProtect(place, length, old_protect, &old_protect);
  FlushInstructionCache(GetCurrentProcess(), place, length);
}

void nop(const size_t place, const size_t length) {
  nop(reinterpret_cast<void*>(place), length);
}

void copy(void* place, const void* data, const size_t length) {
  DWORD old_protect{};
  VirtualProtect(place, length, PAGE_EXECUTE_READWRITE, &old_protect);

  std::memmove(place, data, length);

  VirtualProtect(place, length, old_protect, &old_protect);
  FlushInstructionCache(GetCurrentProcess(), place, length);
}

void copy(const size_t place, const void* data, const size_t length) {
  copy(reinterpret_cast<void*>(place), data, length);
}

bool is_relatively_far(const void* pointer, const void* data,
                       const int offset) {
  const std::int64_t diff = size_t(data) - (size_t(pointer) + offset);
  const auto small_diff = std::int32_t(diff);
  return diff != std::int64_t(small_diff);
}

void call(void* pointer, void* data) {
  if (is_relatively_far(pointer, data)) {
    throw std::runtime_error("Too far away to create 32bit relative branch");
  }

  auto* patch_pointer = PBYTE(pointer);
  set<std::uint8_t>(patch_pointer, 0xE8);
  set<std::int32_t>(patch_pointer + 1,
                    std::int32_t(size_t(data) - (size_t(pointer) + 5)));
}

void call(const size_t pointer, void* data) {
  return call(reinterpret_cast<void*>(pointer), data);
}

void call(const size_t pointer, const size_t data) {
  return call(pointer, reinterpret_cast<void*>(data));
}

void set(std::uintptr_t address, std::vector<std::uint8_t>&& bytes) {
  DWORD oldProtect = 0;

  auto* place = reinterpret_cast<void*>(address);
  VirtualProtect(place, bytes.size(), PAGE_EXECUTE_READWRITE, &oldProtect);
  memcpy(place, bytes.data(), bytes.size());
  VirtualProtect(place, bytes.size(), oldProtect, &oldProtect);
  FlushInstructionCache(GetCurrentProcess(), place, bytes.size());
}

void set(std::uintptr_t address, void* buffer, size_t size) {
  DWORD oldProtect = 0;

  auto* place = reinterpret_cast<void*>(address);
  VirtualProtect(place, size, PAGE_EXECUTE_READWRITE, &oldProtect);
  memcpy(place, buffer, size);
  VirtualProtect(place, size, oldProtect, &oldProtect);
  FlushInstructionCache(GetCurrentProcess(), place, size);
}

void jump(std::uintptr_t address, void* destination) {
  if (!address)
    return;

  std::uint8_t* bytes = new std::uint8_t[5];
  *bytes = 0xE9;
  *reinterpret_cast<std::uint32_t*>(bytes + 1) =
      CalculateRelativeJMPAddress(address, destination);

  set(address, bytes, 5);

  delete[] bytes;
}

void redirect_jump(void* pointer, void* data) {
  char* operand_ptr = static_cast<char*>(pointer) + 2;
  std::int32_t new_operand = reinterpret_cast<std::int32_t>(data) -
                             (reinterpret_cast<std::int32_t>(pointer) + 6);
  set<std::int32_t>(operand_ptr, new_operand);
}

void redirect_jump(size_t pointer, void* data) {
  redirect_jump(reinterpret_cast<void*>(pointer), data);
}

void* assemble(const std::function<void(assembler&)>& asm_function) {
  static asmjit::JitRuntime runtime;

  asmjit::CodeHolder code;
  code.init(runtime.environment());

  assembler a(&code);

  asm_function(a);

  void* result = nullptr;
  runtime.add(&result, &code);

  return result;
}
} // namespace utils::hook