[joaquimandrade]

Originally Posted by jim_yang after, you push a param stack -= 4, so you should add esp, 4 after call it by the way do you use void **pPlayerPointer, it should be void *pPlayerPointer = ent->pvPrivateDate;

Yes, I do understand that I need to add 4 to esp but it still crashes

I think i'm correct because insine assembly excepts me to give it a pointer to the data that I need to pass it. So I give it a pointer to (CBasePlayer *). That's why it is void **. Because it needs a pointer to the data that I want to pass.

[joaquimandrade]

I reached this code:

PHP Code:

typedef void (*RoundRespawn)();
    RoundRespawn roundRespawn = (RoundRespawn) ResolveSig((void *)MDLL_Spawn,"Observer_SetMode__11CBasePlayeri");

    void *pPlayer = (void *) INDEXENT(params[1])->pvPrivateData;
    void **pPlayerPointer = &pPlayer;    
            
    int x;
    void *y;
    x = 3;
    y = &x;

    printf(" ");

    asm __volatile__("add $0x8, %esp");

    asm __volatile__("push %0"::"m"(y));
    asm __volatile__("push %0"::"m"(pPlayerPointer));

    asm __volatile__("call %0"::"m"(roundRespawn)); 


It's not roundRespawn anymore (it makes a player go to First Person View) but the point is that I have now a way of calling the function with any number of arguments. The problem is, i can't remove the annoying printf(" "). It crashes without it. Any idea of how to replace it with real code is appreciated. I'm guessing it performs some operation that corrects something that the code below destroys.

[jim_yang]

player's edict's pvPrivateData itself is already a pointer, which point to the CBasePlayer's object, same as "this", so you don't need to get its address, if you do that, you just make a pointer which point to the pointer, is that what you want?

[joaquimandrade]

Originally Posted by jim_yang player's edict's pvPrivateData itself is already a pointer, which point to the CBasePlayer's object, same as "this", so you don't need to get its address, if you do that, you just make a pointer which point to the pointer, is that what you want?

It was what I wanted but now I've changed the code and it works other way. I fixed the code and I'm making a module out of it.

By the way if you can tell me how to convert a float to a (void *) or vice-versa share with me

Edit: I mean "to cast".

[jim_yang]

float a = 1.f;
void *pa = &a;

why you need cast a float to a pointer?

void foo(void *a, int b, int c)
{
    float x = *(float *)a;
    printf("%f %d %d\n", x, b, c);
}
 
int _tmain(int argc, _TCHAR* argv[])
{
    void (*func)(void *, int, int) = foo;
    float a = 1.f;
    int b = 2;
    int c = 3;
    func(&a, b, c);
    system("pause");
    return 0;
}

[joaquimandrade]

Originally Posted by jim_yang float a = 1.f; void *pa = &a; why you need cast a float to a pointer? void foo(void *a, int b, int c) { float x = *(float *)a; printf("%f %d %d\n", x, b, c); } int _tmain(int argc, _TCHAR* argv[]) { void (*func)(void *, int, int) = foo; float a = 1.f; int b = 2; int c = 3; func(&a, b, c); system("pause"); return 0; }

I don't know exactly if i need it but i'm using (void *) as the generic type to pass arguments and retrieve returns from functions.

PHP Code:

class TypeHandler
{
    public:
        virtual void* convertArgument(cell arg);
        virtual cell convertReturn(void *);
}; 


This worked:

PHP Code:

class FloatHandler : public TypeHandler
{
    public:
        void *convertArgument(cell arg)
        {
            long fixed = (long) amx_ctof(arg);
            return (void*) fixed;
        }
        cell convertReturn(void * ret)
        {
            long fixed = (long) ret;
            return amx_ftoc((float) fixed);
        }    
}; 


I think that tomorrow I'll have the module ready and then I would like tips from you to optimize it and it will be easy to show you what i'm doing.

And big thanks for spending time in this thread.

[jim_yang]

I guess you are working on a universal function invoker or something

[joaquimandrade]

Originally Posted by jim_yang I guess you are working on a universal function invoker or something

Yes. And it is already working I just need to make a file parser and to implement more data types (I think). It will parse functions details in files like:

PHP Code:

"AddPlayerItem"
{
    arguments 
    {
         "CBasePlayer *" , "CBasePlayerItem *"
    }
    signature "AddPlayerItem__11CBasePlayerP15CBasePlayerItem"
} 


And then in a plugin one would do

PHP Code:

AddPlayerItemPointer = getSiggedFuncPointer("AddPlayerItem");
...
ExecuteSiggedFunc(AddPlayerItemPointer,id,weaponID); 


But since it is my first real project using Assembly and C++ i'm taking some time do to it.

I was afraid that it was not possible but now I think it is. I will try to make it also hook but I need to spend some days learning that.

[jim_yang]

definately useful ! nice to see u working on this project

[joaquimandrade]

Originally Posted by jim_yang definately useful ! nice to see u working on this project

Thanks