Code 004

[Bt6K]

Hello,

OpenMP 1.2.0.2670 server
SA-MP 0.3.7 R5 client

I've observed code 004 (1) on my server quite a lot, in what in the cases I've observed are false-positives:

Here are some example logs from two different players:

[2024-08-07T12:31:02+0100] [Info] Player 2 has entered a vehicle!
[2024-08-07T12:31:06+0100] [Info] Player 2 has died!
[2024-08-07T12:31:08+0100] [Info] [Nex-AC debug] Entered veh: 0, veh: 30, entered seat: -1, seat: 0, veh model: 523, enter time: 6876
[2024-08-07T12:31:08+0100] [Info] [Nex-AC] Suspicion on the ID 2. Reason code: 004 (1)
[2024-08-07T12:31:08+0100] [Info] Player 2 has entered a vehicle!
[2024-08-07T12:31:08+0100] [Info] OnPlayerDisconnect(2)
[2024-08-07T12:31:08+0100] [Info] [part] hamood983234 has left the server (2:2)

[2024-08-07T12:38:51+0100] [Info] Player 3 has entered a vehicle!
[2024-08-07T12:40:46+0100] [Info] Player 3 has died!
[2024-08-07T12:40:47+0100] [Info] [Nex-AC debug] Entered veh: 0, veh: 1849, entered seat: -1, seat: 0, veh model: 522, enter time: 118067
[2024-08-07T12:40:47+0100] [Info] [Nex-AC] Suspicion on the ID 3. Reason code: 004 (1)
[2024-08-07T12:40:47+0100] [Info] Player 3 has entered a vehicle!
[2024-08-07T12:40:48+0100] [Info] OnPlayerDisconnect(3)
[2024-08-07T12:40:48+0100] [Info] [part] love1376 has left the server (3:2)

It's important to note it doesn't happen every time, I have not been able to work out exactly what causes it.

I was able to replicate the issue on a blank gamemode using the following:

https://github.com/openmultiplayer/qawno/blob/8f9f619531dc0c354bdcd889fe9975edb53f7b5d/gamemode.new
https://github.com/katursis/Pawn.RakNet/releases/tag/1.6.0-omp
https://github.com/oscar-broman/samp-weapon-config/blob/master/weapon-config.inc

What I find interesting is that in each case, moments after the death is recorded and Nex-AC triggers the kick, some debug code I added to OnPlayerStateChange triggers (i.e. the "has entered a vehicle!").

Any thoughts would be appreciated.

Many thanks

[Bt6K]

This might actually be a weapon-config induced issue, since that second entering of the vehicle that's logged (shown in the first message in this Github issue) when dying doesn't happen when I disable weapon-config:

[2024-08-07T14:36:10+0100] [Info] Player 0 has entered a vehicle!
[2024-08-07T14:36:20+0100] [Info] Player 0 has died!
[2024-08-07T14:36:22+0100] [Info] Player 0 has spawned!

[NexiusTailer]

Did you include weapon-config before nex-ac or after it?

[Bt6K]

Hello, thanks for your prompt reply. Here's how things are currently set up:

// Supress Nex-AC & Weapon-Config Warnings
#pragma warning disable 239
#pragma warning disable 213
#define NO_TAGS

// Includes
#include <open.mp>
#include <sscanf2>
#include <CTime>
#include <streamer>
#include <Pawn.RakNet>
#include <foreach>
#include <nex-ac>
#include <mapfix>
#include <weapon-config>
#include "../include/gl_common.inc"

// Log all MySQL queries to the console?
#define LOG_QUERY false

// Gamemode files
#include "mysql.pwn"
#include "defines.pwn"
#include "player.pwn"
#include "textdraws.pwn"
#include "statistics.pwn"
#include "functions.pwn"
#include "scoreboard.pwn"
#include "duels.pwn"
#include "bans.pwn"
#include "admin.pwn"
#include "accounts.pwn"
#include "timers.pwn"
#include "commands.pwn"
#include "objects.pwn"
#include "veh_effects.pwn"
#include "mselection.pwn"
#include "spectate.pwn"

[Bt6K]

Hello,

I made a video to demonstrate it (blank gamemode using the components I mentioned above).

https://streamable.com/zwq0dj

[2024-08-12T09:10:18+0100] [Info] [Nex-AC debug] Entered veh: 0, veh: 1, entered seat: -1, seat: 0, veh model: 522, enter time: 8985
[2024-08-12T09:10:18+0100] [Info] [Nex-AC] Suspicion on the ID 1. Reason code: 004 (1)
[2024-08-12T09:10:18+0100] [Info] [part] test2 has left the server (1:2)

[NexiusTailer]

So, your client keep sending like he is in vehicle even after spawn.
Share the code from your gamemode which you use to spawn players in the case on the video. Did you also modified anything inside weapon-config.inc?

[Bt6K]

Hi,

This is the stock openmp gamemode - https://github.com/openmultiplayer/qawno/blob/8f9f619531dc0c354bdcd889fe9975edb53f7b5d/gamemode.new

public OnPlayerSpawn(playerid)
{
	SetPlayerInterior(playerid, 0);
	return 1;
}

It is also the stock weapon-config code: https://github.com/oscar-broman/samp-weapon-config/blob/master/weapon-config.inc

I have not modified anything, it's all standard:

https://github.com/openmultiplayer/qawno/blob/8f9f619531dc0c354bdcd889fe9975edb53f7b5d/gamemode.new
https://github.com/katursis/Pawn.RakNet/releases/tag/1.6.0-omp
https://github.com/oscar-broman/samp-weapon-config/blob/master/weapon-config.inc

[NexiusTailer]

I cannot reproduce this at the moment. The problem is in that your client for some reason does not stop sending vehicle sync even after he was spawned and he's not allowed to do so. But idk what can be the cause for this behaviour.

[Bt6K]

I use SAMP Addon, I'm not sure if that would make a difference.

I'll completely erase GTA SA on both computers and reinstall SA:MP 0.3.7-R5-1-MP with no SAMP Addon to see if that makes any difference.

I'll report back here with my findings.

[Bt6K]

Hi,

I reinstalled both computers with a clean copy of GTA SA, and SA:MP 0.3.7-R5-1-MP - no customisations at all.

The issue continued happening: https://streamable.com/brukga

[2024-08-14T13:18:41+0100] [Info] [Nex-AC debug] Entered veh: 0, veh: 1, entered seat: -1, seat: 0, veh model: 522, enter time: 11830
[2024-08-14T13:18:41+0100] [Info] [Nex-AC] Suspicion on the ID 1. Reason code: 004 (1)

However, I just tried with SA-MP 0.3.7-R2 Linux Server, weapon-config and Pawn.RakNet instead of OpenMP 1.2.0.2670 server, weapon-config and Pawn.RakNet, and the issue did not happen.

So, it seems to me that the problem may be specific to OpenMP servers.

[NexiusTailer]

I just tested it exactly with gamemode.new from omp server package and faced this issue.

First of all, the main anticheat code which is triggered is not 004, it's 048:

and this reveal the issue itself: something goes wrong in omp server with changing player states when he dies (state 0/unknown must be only passed when a player connecting, it cannot be in-game after he changed his state to any other). I still didn't figure out what causes such behaviour so that omp server sets player state 0 for a moment, but it should probably be addressed in the server repo with some MCVE and logs (without anticheat and weapon-config included).

[Bt6K]

Hello,

Apologies, I should note that code 048 is another issue, to which you stated:

I ended up disabling code 048 due to the false-positive it created, which you too have now seen.

It was only after disabling code 048 that I discovered that 004 is also triggered by the same action, which I've now disabled as well in order to minimize false-positives.

[NexiusTailer]

Disabling codes not a solution, just report the issue to omp server if you're able to make a minimal reproducible example.

I should note that code 048 is another issue

No, it's all the same, since they all have a single cause.

[Bt6K]

Hi @NexiusTailer,

I figured I'd try enabling all Nex-AC codes again, as in that time, a lot has changed (i.e. Nex-AC was updated, open.mp server was updated, etc), however I still see a huge amount of these in the logs:

[2025-03-31T23:30:42+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-03-31T23:30:42+0100] [Info] [Nex-AC] Suspicion on the ID 1. Reason code: 048 (2)
[2025-04-01T05:48:59+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-04-01T05:48:59+0100] [Info] [Nex-AC] Suspicion on the ID 0. Reason code: 048 (2)
[2025-04-01T05:50:33+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-04-01T05:50:33+0100] [Info] [Nex-AC] Suspicion on the ID 0. Reason code: 048 (2)
[2025-04-01T05:53:06+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-04-01T05:53:06+0100] [Info] [Nex-AC] Suspicion on the ID 0. Reason code: 048 (2)
[2025-04-01T06:01:48+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-04-01T06:01:48+0100] [Info] [Nex-AC] Suspicion on the ID 3. Reason code: 048 (2)
[2025-04-01T06:15:21+0100] [Info] [Nex-AC debug] Newstate: 1, oldstate: 0
[2025-04-01T06:15:21+0100] [Info] [Nex-AC] Suspicion on the ID 1. Reason code: 048 (2)

I know you previously said:

I still didn't figure out what causes such behaviour so that omp server sets player state 0 for a moment, but it should probably be addressed in the server repo

I just wondered - has anything more come to light since then?

No worries if not, but I thought it would be worth asking the question.

Thanks.

[NexiusTailer]

I just wondered - has anything more come to light since then?

No worries if not, but I thought it would be worth asking the question.

Thanks.

Now it's reported in omp server repo (see the first part there), but still relevant and not yet solved, unfortunately: openmultiplayer/open.mp#1008