Easy to Hook :)

K.K.Lv · **Author**

First of all, thanks my friend who name's Nagist make metahook .
what you can do with metahook ?
1. Hook virtual table function just like hamsandwich(support windows and linux)
2. Find the function address with the signature, use or hook it(windows only)
3. Hook the API function(windows only)

Ok, now i will show you how to hook virtual table function,
about the function offset we know it can be found at the "hamdata.ini",
yeah this is enough, I will hook player spawn, so the offset is 0 on windows, 2 on linux.

And now I will hook it at entity spawn callback, and it should be very simple to do it just like this ;) all of the code is here. got it ?

Code:

#include "amxxmodule.h"
#include "metahook.h"

//this is the original address
void (__fastcall *g_pfnCBasePlayer_Spawn)(/*CBasePlayer*/void *pThis, int) = NULL;

//this is the new addr
void __fastcall CBasePlayer_Sapwn(void *pThis, int)
{
    SERVER_PRINT("\n\tHook player spawn pre.\n");
    g_pfnCBasePlayer_Spawn(pThis, 0);//call the original function
    SERVER_PRINT("\n\tHook player spawn post.\n");
}

int DispatchSpawn(edict_t *ent)
{
    const char *classname = STRING(ent->v.classname);

    if (!strcmp(classname, "worldspawn"))
    {
        if (!g_pfnCBasePlayer_Spawn)
        {
            //register a entity spawn hook which the classname is "player"
            edict_t *pEntity = g_engfuncs.pfnCreateNamedEntity(MAKE_STRING("player"));//create a new entity
            void *pClassData = pEntity->pvPrivateData;//store the class data
            
            //and hook it 
            MH_VFTHook(pClassData, 0, 0, CBasePlayer_Sapwn, (void*&)g_pfnCBasePlayer_Spawn);
            g_engfuncs.pfnRemoveEntity(pEntity);//remove the entity
        }
    }
    RETURN_META_VALUE(MRES_IGNORED, 0);
}
void OnMetaAttach(){}

the following code will show you how to find function and hook it with signature:
note that: when use inline hook, have to enable this line;

PHP Code:


			
#define DISABLE_INLINEHOOK 1

==>

PHP Code:


			
#define DISABLE_INLINEHOOK 0

Code:

#include "amxxmodule.h"
#include "metahook.h"

#define HANDLEMENU_CHOOSETEAM "\x83\xEC\x2A\x8B\x0D\x2A\x2A\x2A\x2A\x53\x55\x56\x8B\x74\x2A\x2A\x57\x33\xFF"

typedef BOOL (*Func_HandleMenuChoose)(CBasePlayer *pPlayer, int slot);
Func_HandleMenuChoose HandleMenuChooseOri = NULL;
BOOL HandleMenuChooseHook(CBasePlayer *pPlayer, int slot);
bool hookCreate();

HMODULE g_hMod;
DWORD g_dwModBase, g_dwModSize;

BOOL HandleMenuChooseHook(CBasePlayer *pPlayer, int slot)
{
    BOOL bRet = FALSE;
    //hook pre
    bRet = HandleMenuChooseOri(pPlayer, slot);
    //hook post
    return bRet;
}

void OnMetaAttach()
{
    g_hMod = GetModuleHandle("mp.dll");
    
    g_dwModBase = MH_GetModuleBase(g_hMod);
    g_dwModSize = MH_GetModuleSize(g_hMod);
    
    bool result = hookCreate();
    
    printf("Address Patch : %s\n", result ? "Success" : "Failed" );
}

bool hookCreate()
{
    HandleMenuChooseOri = (Func_HandleMenuChoose)MH_SearchPattern((void*)g_dwModBase, g_dwModSize, HANDLEMENU_CHOOSETEAM, sizeof(HANDLEMENU_CHOOSETEAM) - 1);

    return MH_InlineHook(HandleMenuChooseOri, HandleMenuChooseHook, (void*&)HandleMenuChooseOri) ? true : false;
}