imring/RakHook

RakHook

RakHook is a library that adds RakNet events (incoming/outgoing Packets & RPC), emulation and sending Packets & RPC.
There is support for versions 0.3.7-R1, 0.3.7-R3-1, 0.3.7-R4 and 0.3DL-R1.

The RakHook part is header-only and does not depend on any hooking library directly: all hooks are installed through a compile-time hook implementation (wrapper) of your choice.

Functions

Common

• rakhook::version_manager - Detects the samp.dll base address and the entry point and selects the matching offsets for the supported versions.
• rakhook::signal<Func> - Event container used by the hooker (callbacks are called in order, bool callbacks can stop the event by returning false).

Wrappers

rakhook::hooker<HookImpl> is a class template with static members, where HookImpl is a hook implementation.
RakHook has 3 ready-to-use wrappers:

• rakhook::wrappers::cyanide for cyanide;
• rakhook::wrappers::minhook for minhook;
• rakhook::wrappers::kthook for kthook.

Events

• bool rakhook::hooker<HookImpl>::initialize() - Initialize RakHook.
• void rakhook::hooker<HookImpl>::destroy() - Destroy RakHook.
• signal<send_t> rakhook::hooker<HookImpl>::on_send_packet - Outgoing the packet.
• signal<receive_t> rakhook::hooker<HookImpl>::on_receive_packet - Incoming the packet.
• signal<send_rpc_t> rakhook::hooker<HookImpl>::on_send_rpc - Outgoing RPC.
• signal<receive_rpc_t> rakhook::hooker<HookImpl>::on_receive_rpc - Incoming RPC.
• bool rakhook::hooker<HookImpl>::send(RakNet::BitStream *bs, PacketPriority priority, PacketReliability reliability, char ord_channel) - Send the packet.
• bool rakhook::hooker<HookImpl>::send_rpc(int id, RakNet::BitStream *bs, PacketPriority priority, PacketReliability reliability, char ord_channel, bool sh_timestamp) - Send RPC.
• bool rakhook::hooker<HookImpl>::emul_packet(RakNet::BitStream &pbs) - Emulate the packet.
• bool rakhook::hooker<HookImpl>::emul_rpc(unsigned char id, RakNet::BitStream &rpc_bs) - Emulate RPC.

Example

You can learn the example here.

Custom SA:MP version

If the loaded samp.dll version is not supported by RakHook, you can add it manually with rakhook::version_manager::add_version before rakhook::hooker<HookImpl>::initialize() is called:

using rh = rakhook::hooker<rakhook::wrappers::cyanide>;

// 0.3.7-R1
rh::versions.add_version(0x31DF13, {
    .samp_info           = 0x21a0f8, // CNetGame singleton
    .rakclient_interface = 0x3c9,    // CNetGame::m_pRakClient offset
    .destroy_interface   = 0x342d0,  // function to destroy CNetGame::m_pRakClient
    .handle_rpc_packet   = 0x372f0,  // RakPeer::HandleRPCPacket function
    .alloc_packet        = 0x347e0,  // AllocPacket function (see RakPeer.cpp)
    .offset_packets      = 0xdb6,    // RakPeer::packetSingleProducerConsumer offset
    .write_lock          = 0x35b10,  // DataStructures::SingleProducerConsumer::WriteLock function
    .write_unlock        = 0x35b50,  // DataStructures::SingleProducerConsumer::WriteUnlock function
});

rh::initialize(); // returns false if the loaded samp.dll is still unknown 

The first argument is the AddressOfEntryPoint from the PE header of the target samp.dll and all version_offsets fields are offsets relative to the module base, except offset_packets, which is a struct offset.

Custom hook

A custom hook implementation must provide:

struct my_hook {
    static bool initialize();
    static void uninitialize();

    template <typename Fn, auto Detour>
    struct hook {
        hook(Fn target);
        bool install();
        bool uninstall();
        Fn get_original();
    };
};

where Detour is a function pointer of the form Ret (*)(Fn original, Args...).

CMake options

• RAKHOOK_WRAPPER_CYANIDE - build the library with cyanide (rakhook::cyanide).
• RAKHOOK_WRAPPER_MINHOOK - build the library with MinHook (rakhook::minhook).
• RAKHOOK_WRAPPER_KTHOOK - build the library with kthook (rakhook::kthook).
• RAKHOOK_TESTS - build unit tests for the hook wrappers.
• RAKHOOK_EXAMPLE - build the example.
• RAKHOOK_EXAMPLE_WRAPPER - hook wrapper used by the example: auto (default, the first enabled one), cyanide, minhook or kthook.
• RAKHOOK_INSTALL - install targets and headers.

cyanide and kthook cannot be enabled at the same time because both vendor xbyak.

Use in projects

Recommended way to link the library - FetchContent, but you can use others (submodule, install, etc).