The quest for 32 player MD servers

[Samuco 297]

I have (stupidly) embarked on a quest to raise the maximum player limit of Halo MD and I'll use this forum to document my progress. It might help someone with a similar aim, or someone may know something that will help me. 

 

Machine Table ([0x8068600] + 0xaa0)

This table stores pointers to machine structures which contain IP addresses and other goodies.

Quote

[mystery pointer (4 byte)] [player0 pointer (4 byte)]  [player1 pointer (4 byte)] [player2 pointer (4 byte)] ...  [player16 pointer (4 byte)] [01 01 00 00]

 

All offsets are hardcoded into assembly and those 01 01 00 00 bytes cannot be overridden. Instead, I moved them (and corrected the offsets in assembly). This allows more than 16 connections.

Quote

[mystery pointer (4 byte)] [player0 pointer (4 byte)]  [player1 pointer (4 byte)] [player2 pointer (4 byte)] ...  [player16 pointer (4 byte)] [player17 pointer (4 byte)] [player18 pointer (4 byte)] [01 01 00 00]

 

 

Game Table (0x477580)

This structure contains the game name, map name, game type, player names and player hashes (amongst other things)

Quote

[pointers and such (8 bytes)] [game name] [... unknown ...] [map name] [... unknown ...] [gametype] [... unknown ...] [player names (0x20 * 16)] [... stuff ...] [player encryption keys (0x60*16)] [... unknown ...] [game password] 

 

I moved the  [... stuff ...] [player encryption keys (0x60*16)] further down, which means that the player names have more room to expand. I also increased the player names and hash slots.

 

Mystery Table 1 (0x413224)

 

client update queue

 

server update queue

 

Network Table (0x4655A0)

Look, more slots and junk after them which makes resizing difficult. Contains the game password, "message in a bot" (note the similarity to the netcode!), player names, player numbers etc. 

 

Resized to

 

Player Table (0x402AAF90 or [0x45E5A8])

Resized from 16 to 32 slots

 

Player Number Checks

Oh my god there are so many of these. Everywhere!

 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

Progress

Here is essentially what happens when Player 17 joins

Client joins the game with 16 players

Server says… Hey buddy welcome, you're player 17!

Client says.. Nice! my name is Bob and im player 17

Server says… Hi Bob! here are the names of the 17 players in the game

Client says… Wtf 17 players??? -disconnects-

 

All of the other clients promptly disconnect when they are informed player 17 joined. Previously, they didn't quit (and sv_players showed all 17 players), but Player 17 didn't get a body. 

The server doesn't crash when Player 17 joins. I suspect when the clients receive a player number >= 0x10 they disconnect because there is another player check somewhere. 

 

Okay, clients are no longer randomly disconnecting when player 17 joins. I can confirm that player 17 gets a player object (in the player table). 

 

However, the server then stops working and displays a "network connection lost" message

 

It looks like the "aa 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00" packet overflowed

 

 

Few packets down. Added a Mystery Table and client/server queues. Player17 now shows up in the \query, gets an actual player and a few other other goodies. Clients are now suiciding on one of the update packets

Quote

 

fe fe 00 01 05 07 7b                              ......{

8c 02 01 00 44 00 72 00 61 00 67 00 6f 00 6e 00   ....D.r.a.g.o.n.

31 00 34 00 32 00 30 00 34 00 00 00 0b ff ff 02   1.4.2.0.4.......

00 00 02 00 00 0a fa 18 18 05 02 00 88 00 e4 00   ................

c2 00 ce 00 de 00 dc 00 62 00 60 00 68 00 66 00   ........b.`.h.f.

70 00 00 00 16 fe ff 0d 00 00 0c 00 00 14 f4 31   p..............1

30 0a 04 00 10 01 c8 01 84 01 9c 01 bc 01 b8 01   0...............

c4 00 d0 00 e4 00 e4 00 e4 00 00 00 2c fc ff 2f   ............,../

00 04 2c 00 00 28 e8 63 90 c6                     ..,..(.c..

 

 

 

I've found a pretty amazing structure that explains all of the packets

 

[Samuco 297]

[swamp 1,017]

The only thing I see this being useful for is huge fucking maps. Luckily, we could use more players on huge fucking maps.

[NerveBooger 134]

I believe that teams are set up to, and may exceed 16 slots.  Team games (ctf) = 2 teams, FFA games = 16 'teams' - PLUS -  red and blue team designation for each FFA player is assignable/writeable.  In team games, the FFA team designation is 0xfff, but can also be assigned/written.  This is how I accidentally achieved multi-team vehicles in FFA games for phasor - I was muckin about testing multiple things in one setting, including writing "sv_maxplayers 32" in a devmode manner -   the 17th player could join, quit and leave, but the server still showed them in the server after they quit (buffer not flushing maybe?, "We got a floater!"). 

 

Later AelitePrime wrote a cleaner script that simply wrote the FFA players "Team" to be red team - which also sometimes means you "betray" your non-teammate.  Having a no lag multi-team vehicle is kick ass for adding variety.

 

So what does all that crap have to do with your endeavor?  Keep at it, you may discover other "happy accidents" along the way.  Use mac/md - I don't care, but be willing to share as you have done so you or others may develop the same for PC/full versions.

 

Nice job, wish I knew how to do that schtuff . . . but also kinda glad I don't, it would act as a sensual lube for my halo addiction, and the last thing I need is to have "Halo PC: Ribbed and lubed for your pleasure."

[NeX 1,756]

But this would have to be a server extension, yeah? Phasor is open sourced, but then theres sehe, who is known for his jovial graciousness

[WaeV 5,049]

It would have to be a server extension as well as a client extension, yeah. Fortunately Phasor won't be far behind SAPP once it gets official no-lead support (one of these days, apparently).

[Floofies 2,470]

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[Kavawuvi 7,026]

This will be great to see in the future. There aren't a lot of maps that would benefit from this, certainly not any stock map that's for sure. Enormous maps will see the most use, though I wouldn't mind seeing a 32 player Battle Creek server for laughs.

It would have to be a server extension as well as a client extension, yeah. Fortunately Phasor won't be far behind SAPP once it gets official no-lead support (one of these days, apparently).

 

Phasor will probably remain the most vanilla server extension, due to it having only a few features on its own, while SAPP has a lot of features upfront. It's not necessarily a bad thing, as hosts can install only the things they want. A lot of features missing can be pretty essential, though, like rcon brute force protection, aimbot protection, and, of course, no-lead.

Edited January 2, 2015 by 002

[Samuco 297]

I figure I should post a general update on what happened to this plugin.

 

There are quite a few things I didn't bother putting in the thread. It's missing a tonne of tables and basically all information about Halo code I had to modify. I suspect the Halo code has a #define kMaxPlayers 16 or something statement, which is why increasing the limit is a pain   I got to the point on this plugin where 17 players could join a game and could all move around etc. There are still a few glitches (some packets are broken, I've overridden stuff not related to netcode and it has screwed with the radar etc). I never tried to get 18 players into the game so for all I know it's possible. Uni summer break ended and the plugin has been on hold ever since  . I've recently been building a new Halo client using Electron which has the ability to join games, chat, move around, shoot, show enemy players etc. I've decoded a lot of the net code, which has taught me a lot of things (and shown me some of the packets which need modification). I imagine having a lightweight client which is capable of supporting 32 players is useful for programming the SAPP side of things. However, I still have college, a thesis and post graduate college applications to worry about, so it's still on hold.

 

TL;DR - I have a Halo MD client/server that supports 17 players but I'm busy and don't have time at the moment to finish it

[MrMew 9]

Having this number of players on a map would certainly improve some of the larger ones such as infinity or a custom map like presidio.