AlliedModders - [L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T

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- - [L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T (https://forums.alliedmods.net/showthread.php?t=336151)

[L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T

Hello everyone:), I am a newbie in signature scanning and SDKCall using.

I am trying to make a function in coop mode that when special infecteds all dead and there is only a bot tank in the spot, the bot tank will evade to find a cover instead of continuing approaching to survivors and taking damage.

I have tried to use BossZombiePlayerBot::ShouldRetreatToCover signature

PHP Code:


		
			
_DWORD __cdecl BossZombiePlayerBot::ShouldRetreatToCover(BossZombiePlayerBot *__hidden this)

because i could not found any function like ChargerEvade::ChargerEvade(void) or BoomerRetreatToCover::BoomerRetreatToCover(Bo omerRetreatToCover *__hidden this, TerrorNavArea *) on tank.

In linux, the call sequence is probably like this:

PHP Code:


		
			
BossZombiePlayerBot::ShouldRetreatToCover -> CDirector::SpecialsShouldRetreatToCover -> CDirectorChallengeMode::SpecialsShouldRetreatToCover

there is a string "cm_SpecialsRetreatToCover" in "CDirectorChallengeMode::SpecialsShouldRetrea tToCover" so we can scan the string to find BossZombiePlayerBot::ShouldRetreatToCover signature.

But in server.dll binary i have tried to find string "cm_SpecialsRetreatToCover" an go to it's xref "sub_1025ADB0", i think it is "CDirectorChallengeMode::SpecialsShouldRetrea tToCover" function but there is no an "Up" xref to "sub_1025ADB0" which mean i couldn't find "CDirector::SpecialsShouldRetreatToCover" signature.

So i am confused in how to find "BossZombiePlayerBot::ShouldRetreatToCove r" signature in windowsT^T

I also have tried to use SDKCall to call "CDirector::SpecialsShouldRetreatToCover" directly in linux server, the code is like this

PHP Code:


		
			
#pragma semicolon 1
#pragma newdecls required

#include <sourcemod>
#include <sdktools>

#define GAMEDATA "test"

Handle g_hRetreatToCover;

public void OnPluginStart()
{
    Handle g_hGameConf = LoadGameConfigFile("test");
    if (g_hGameConf == INVALID_HANDLE)
    {
        SetFailState("can't read test in gamedata folder");
    }
    StartPrepSDKCall(SDKCall_Player);
    PrepSDKCall_SetFromConf(g_hGameConf, SDKConf_Signature, "BossZombiePlayerBot::ShouldRetreatToCover");
    g_hRetreatToCover = EndPrepSDKCall();
    if (g_hRetreatToCover == INVALID_HANDLE)
    {
        SetFailState("can't read signature BossZombiePlayerBot::ShouldRetreatToCover");
    }
    RegConsoleCmd("sm_ret", Cmd_Retreat);
}

public Action Cmd_Retreat(int client, int args)
{
    if (client && client <= MaxClients && IsClientInGame(client) && GetClientTeam(client) == 2 && !IsFakeClient(client))
    {
        int iTank;
        for (int i = 1; i < MaxClients; i++)
        {
            if (IsValidEntity(i))
            {
                if (GetEntProp(i, Prop_Send, "m_zombieClass") == 8)
                {
                    iTank = i;
                }
            }
        }
        SDKCall(g_hRetreatToCover, iTank);
        PrintToChatAll("\x03info：SDKCall finished");
    }
}

The test.txt in gamedata folder is like this

PHP Code:


		
			
"Games"
{
    "left4dead2"
    {
        "Signatures"
        {
            /*
            *  BossZombiePlayerBot::ShouldRetreatToCover(BossZombiePlayerBot *__hidden this)
            */
            "BossZombiePlayerBot::ShouldRetreatToCover"
            {
                "library"    "server"
                "linux"    "@_ZNK19BossZombiePlayerBot20ShouldRetreatToCoverEv"
            }
        }
    }
}

The code has no effect when i spawned a tank and type !ret in the chat, there may be some mistakes in the code because i couldn't use SDKCall proficientlyT^T
May be we could use another method to achieve this function:stupid:

Re: [L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T

This function calls this:

PHP Code:


		
			
char __cdecl CDirectorChallengeMode::SpecialsShouldRetreatToCover(CDirectorChallengeMode *this)
{
  char result; // al

  result = *((_BYTE *)this + 1);
  if ( result )
    result = CDirector::GetScriptValue(TheDirector, "cm_SpecialsRetreatToCover", 0) != 0;
  return result;
}

So you could set "cm_SpecialsRetreatToCover" to "1" probably via VScript although that might not have the desired result, depends when the "CDirectorChallengeMode::SpecialsShouldRetrea tToCover" function gets called which might not be in any think function for the tank.

To find the sig on windows see the TUT link in my signature, there's a link that explains how to find stuff by vtable if there are no strings. But SDKCalling this is unlikely to make the tank retreat.

Re: [L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T

Quote:

Originally Posted by Silvers (Post 2770023)

This function calls this:

PHP Code:


		
			
char __cdecl CDirectorChallengeMode::SpecialsShouldRetreatToCover(CDirectorChallengeMode *this)
{
  char result; // al

  result = *((_BYTE *)this + 1);
  if ( result )
    result = CDirector::GetScriptValue(TheDirector, "cm_SpecialsRetreatToCover", 0) != 0;
  return result;
}

Thanks a lot, Silvers, and sorry for my late reply. I have tried to write a simple VScript named coop.nut like this and tested it in coop mod, linux server

PHP Code:


		
			
DirectorOptions <-
{
    cm_SpecialsRetreatToCover    = 1
}

And as you said, the VScript didn't perform me the desired effect, for example, I spawned a smoker and it still will tried to approach to survivors and perform a drag instead of retreating, and so did tank, would not retreat after spawning.

I will try another method, first use L4D_GetRandomPZSpawnPosition function in left4dhooks.inc to get a random spawn position, then use

PHP Code:


		
			
CommandABot(  {cmd = DirectorScript.BOT_CMD_MOVE, pos = Vector( %f, %f, %f)}, pos[0], pos[1], pos[2] )

to let bot tank go to the specific position which generated by L4D_GetRandomPZSpawnPosition function. Hope this method will work.

I watched the video on youtube of sigscanning intro and how to make good signatures, I have learnt a lot of sigscanning, and i will continue learning sigscanning and vtable using from your tutorial.

Whatever, thanks so much for your help and happy Chinese New Year.:)

Re: [L4D2] Windows signature need help(BossZombiePlayerBot::ShouldRetreatToCove r)T^T

The different approach to do what you want, is to change zombie class of tank to "smoker". Such a way he will inherit smoker's "cover" behaviour. I think BHaType has published such work.