[Question] "Beginning" Lua programming

[Krillere]

Hello, I've just started in the ME business. I tried making some code after looking at all the great documentation.

I've tried this code:

BlackMagic WoW = new BlackMagic();
WoW.OpenProcessAndThread(SProcess.GetProcessFromWindowTitle("World of Warcraft"));

uint CodeCave = WoW.AllocateMemory();

WoW.Asm.Clear();

WoW.Asm.AddLine("var_18= dword ptr -18h");
WoW.Asm.AddLine("var_4= dword ptr -4");
WoW.Asm.AddLine("arg_0= dword ptr  8");

WoW.Asm.AddLine("push    ebp");
WoW.Asm.AddLine("mov     ebp, esp");
WoW.Asm.AddLine("push    ecx");
WoW.Asm.AddLine("push    ebx");
WoW.Asm.AddLine("push    esi");
WoW.Asm.AddLine("mov     esi, [ebp+arg_0]");
WoW.Asm.AddLine("push    edi");
WoW.Asm.AddLine("push    1");
WoW.Asm.AddLine("push    esi");
WoW.Asm.AddLine("call    sub_827110");
WoW.Asm.AddLine("add     esp, 8");
WoW.Asm.AddLine("test    eax, eax");
WoW.Asm.AddLine("jz      loc_4A6752");

WoW.Asm.InjectAndExecute(CodeCave);
WoW.FreeMemory(CodeCave);

That ASM code is the code for DoEmote(), it fails at

WoW.Asm.InjectAndExecute(CodeCave);

After that code failed, I began looking at the pseudo code, the pseudo code for DoEmote is this;

int __cdecl sub_4A6610(int a1)
{
  char *v1; // eax@3
  char *v2; // esi@3
  int v4; // esi@6
  int v5; // edi@7
  int v6; // ebx@10
  int v7; // eax@15
  int v8; // ecx@15
  int v9; // edi@15
  int v10; // esi@15
  int v11; // edx@18
  int v12; // eax@19
  int v13; // edx@19
  int v14; // ST18_4@21
  char *v15; // [sp+14h] [bp-4h]@2

  if ( sub_827110(a1, 1) )
  {
    v15 = (char *)sub_827290(a1, 1, 0);
    if ( !sub_7019D0(v15, "DANCE", 0x7FFFFFFFu) )
    {
      v1 = (char *)sub_827290(a1, 2, 0);
      v2 = v1;
      if ( v1 )
      {
        if ( (unsigned __int8)sub_50DAC0(v1) )
        {
          sub_50D9F0(v2);
          return 0;
        }
      }
    }
    v4 = dword_A75074;
    if ( dword_A75074 )
    {
      v5 = 76 * dword_A75074;
      while ( 1 )
      {
        --v4;
        v5 -= 76;
        if ( v4 < 0 || v4 >= dword_A75074 )
          v6 = 0;
        else
          v6 = v5 + dword_A75088;
        if ( !sub_7019D0(v15, *(char **)(v6 + 4), 0x7FFFFFFFu) )
          break;
        if ( !v4 )
          return 0;
      }
      v10 = dword_B695C8;
      v9 = dword_B695CC;
      v7 = sub_827290(a1, 2, 0);
      if ( v7 )
      {
        LOBYTE(v8) = *(_BYTE *)v7;
        if ( *(_BYTE *)v7 )
        {
          if ( (_BYTE)v8 != 37 )
          {
            v10 = sub_4C4DC0(v7, 16, 0, 0, 3.402823466385289e38, 0);
            v9 = v11;
          }
        }
      }
      v12 = sub_47A5C0(v8);
      if ( sub_47BBC0(v12, v13, 16) )
      {
        sub_671C90(v6, v10, v9);
        return 0;
      }
    }
  }
  else
  {
    sub_828430(a1, "Usage: DoEmote(\"emote\"[, \"target\"])", v14);
  }
  return 0;
}

But I don't know how to call DoEmote using the pseudo-code, any pointer on how to do that would be nice! But, the main question still is; How do I make the ASM stuff work? :-)

( I did read the rules, and I don't think that this is breaking it, if it is just delete it.. )

[flo8464]

WoW.Asm.AddLine("var_18= dword ptr -18h");
WoW.Asm.AddLine("var_4= dword ptr -4");
WoW.Asm.AddLine("arg_0= dword ptr 8");

This is not only wrong; this wrong-wrong.

Just use lua_dostring/Framescript::Execute or whatever.
Your attempt is wrong from the beginning to the end.

[Krillere]

Ok, I tried a new approach, I used IDA to find the CastSpellById function, this was the ASM Code I found:

push    ebp
mov     ebp, esp
sub     esp, 2E8h
push    esi
mov     esi, [ebp+arg_0]
push    1
push    esi
call    sub_8270D0
add     esp, 8
test    eax, eax
jnz     short loc_4D7101

Then, I tried doing it with BlackMagic ( changing a few things though! )

            BlackMagic WoW = new BlackMagic();
            WoW.OpenProcessAndThread(SProcess.GetProcessFromWindowTitle("World of Warcraft"));

            uint CodeCave = WoW.AllocateMemory();
            WoW.Asm.Clear();
            const uint CastSpellById = 0x004D70D0;

WoW.Asm.AddLine("push    ebp");
WoW.Asm.AddLine("mov     ebp, esp");
WoW.Asm.AddLine("sub     esp, 2E8h");
WoW.Asm.AddLine("push    esi");
WoW.Asm.AddLine("mov     esi, [ebp+arg_0]");
WoW.Asm.AddLine("push    1");
WoW.Asm.AddLine("push    esi");
WoW.Asm.AddLine("call    sub_8270D0");
WoW.Asm.AddLine("add     esp, 8");
WoW.Asm.AddLine("test    eax, eax");
WoW.Asm.AddLine("jnz     short {0}", CastSpellById);
WoW.Asm.AddLine("retn");

WoW.Asm.InjectAndExecute(CodeCave);
WoW.FreeMemory(CodeCave);

But now I'm unsure. I'm trying to figure out what the

[ebp+arg_0]

and the

sub_8270D0

is, if anyone could help me with this I would be gratefull. I changed the

loc_4D7101

to the address, don't ask me why, but it seemed right. Atleast I tried this time, this may be the wrong approach, but I really want to learn this. Thanks in advance, Krillere.

Edit: Sorry for doubleposting, didn't notice.

[Apoc]

If you don't have a basic understanding of ASM, you shouldn't be messing with it.

Closing this thread until you do at least a little bit of research.

Hint: Copy/pasting from IDA isn't correct.