cyanide

Library comprising the utilities for memory-related hacking like hooks, signature scanning, patching, etc.

Prerequisites

1. If you're going to use the subhook backend, install Yasm and put its directory in the PATH.
2. Grab the cyanide in a way you like: submodule, installing, FetchContent (preferred).

Usage

Hooks

Hooks are divided into two parts: frontend and backend. Any third-party hooking library can be a backend, given you implement a DetourBackendInterface for it. It simply redirects the program flow to another routine with the same parameters and exactly same calling convention. This is not as convenient as you would like it to be - in most cases you may need to transmit some context to the hook callback, which could be done by making the callback a member function - but that isn't possible as member function has a different calling convention.

Frontend part to the rescue! It generates a wrapper with the necessary calling convention, that, in turn, will call your callback. And in this case the callback may be everything that can be placed in std::function - a plain function, a lambda, result of an std::bind, etc.

Finally, an example:

int func_to_hook(int x, int y)
{
    if (x == 0)
        return 0;

    x *= 2;
    y *= 3;

    return y / x;
}

cyanide::memory::SubhookDetourBackend backend;
cyanide::memory::DetourFrontend       frontend{
    &backend,
    &func_to_hook,
    [](decltype(&func_to_hook) orig, int x, int y) -> int {
        return orig(x, y) + 5;
    }};

frontend.install();

Note that receiving an orig parameter in the callback is optional - if you don't want to call the original function you may just omit it.