Fix for Linux Loki Checksum bug

Xamindar · Post by **Xamindar** » Sat Mar 25, 2006 7:30 pm

Munk, you are my hero. So far it works perfectly for me. All I can say is WOW!

sugoi! sugoi! sugoi!

Nosferatu · Post by **Nosferatu** » Sat Mar 25, 2006 11:44 pm

I was wondering if this could be used, or sometime in the future be used, to run a linux server that does allows other windows games to connect to it.

It would be nice if I could eventually chuck the need to run it under wine.

Munk · Post by **Munk** » Sun Mar 26, 2006 2:42 am

@FunkyStickman: sent you an PM.

@Nosferatu: yes, should be no problem. Just filter the other way around and have a reverse lookup. Will try that next week. But Loki can only run one instance only at the same time, since you can't tell it which port to use.

Top Gun · Post by **Top Gun** » Tue Mar 28, 2006 1:57 pm

All right, you're in the PD news. Keep up the great work.

Munk · Post by **Munk** » Thu Mar 30, 2006 11:40 am

Ok, as the last bugs have been fixed and no new have been reported, I'll try to add some options to allow loki servers, disable internet/lan scan etc.

FunkyStickman · Post by **FunkyStickman** » Thu Mar 30, 2006 3:20 pm

I just found a bug! I'm running the 1.6 filter, and when I try to auto-download a level, D3 crashes with a Segfault (Signal 11). I stopped the filter, re-tried the level, and it downloaded without a problem.

Munk · Post by **Munk** » Fri Mar 31, 2006 3:56 am

This bug does not appear on my machine.
Which Server, which mission, which ship ?

FunkyStickman · Post by **FunkyStickman** » Fri Mar 31, 2006 6:43 am

It was on D1.Descent.cx and the level was \"D3 Krackdown\". I was in the Pyro-GL.

Munk · Post by **Munk** » Sun Apr 02, 2006 2:35 am

I'm sorry Funky, I can't reproduce this bug. Seems fine on my machine. Only the third download URL works. At other locations, I get an \"Unable to download mission\", but Descent does not crash.

FunkyStickman · Post by **FunkyStickman** » Sun Apr 02, 2006 11:06 am

Very interesting. It's not a deal-breaker, so I can live with it. If I run across anything else like this, I'll let you know. It could have just been D3 crapping out because it couldn't download it.

Again, fantastic work, keep it up.

Xamindar · Post by **Xamindar** » Fri Apr 07, 2006 1:40 am

I can't seem to be able to specify an ip and connect when this thing is running. Is there a way around this?

Munk · Post by **Munk** » Fri Apr 07, 2006 4:39 am

Yes you can. But the result of the Direct-IP-Server will be mixed within the servers that come from the trackers.

You can use the following bug/feature:
Enter your IP and Port in the input field. In the meantime, the tracker list will show up.
After the tracker list had shown, click on \"scan for local games\". This will only show you local games (in LAN). Surely their aren't any, so this will flush the whole list (for about 20 seconds).
Now press 'Enter' in the input field (or click on 'search for games at address'. Then your specified server will show up.

Sorry that this is a bit confusing. It's an artefact I had to build in because Descent can't handle server lists with more than 12 servers very well.

Someone asked how this gamebrowser is able to show internet games. Well ok:
When Descent tries to find gameservers in LAN, it sends a \"is anyone here serving descent?\"-Message to the network broadcast address (255.255.255.255). Usually this Message will be routed to all computers in LAN. If a gameserver is running somewhere in LAN and gets this message, it responds to the sender with \"my name is VEX-Server, I'm running on IP 123.45.67.89, my mission is Ascent ...\" (you get the idea).
Your Internet Service provider will not route those broadcast messages, as this would mean to send it to all those billions machines on the internet. Thats why this gamebrowser does not work with internet servers.
So it's just a problem of routing.

Fortunatly, there are servers in the internet how know where descent3 gameservers are running. They are called \"trackers\". One of them is http://d3.descent.cx.
Now, what d3fix does is: with its packet filter it can detect when the \"is anyone here\"-broadcast message is send from your gamebrowser. When this happens, it connects to the d3.descent.cx-tracker and gets a list of running internet gameservers. It then creates identical \"is anyone here\"-messages which are then send to these internet gameservers (knowing there IP).
The gameserver will respond that message to the origin containing his server details. Descent receives these responses, and displays them in the gamebrowser serverlist.

Xamindar · Post by **Xamindar** » Fri Apr 07, 2006 10:48 am

Thanks Munk, I'll do that. I just had a frustrating time last night trying to connect to my friend. At first I loaded d3fixd with D3 which showed all the internet games and then tried putting his ip in. I couldn't find it in the list so I reloaded the game without d3fixd but then I couldn't get ANY games to show up, whether my friend's or any other internet game when I typed it in the ip field. It was very strange.

Munk · Post by **Munk** » Sat Apr 08, 2006 1:34 am

It is maybe so, that when you kill (signal KILL, STOP) the d3fixd, it cannot clear the kernels ip filter rules.

try \"# iptables -t mangle -L\" to show the relevant filter rules used by d3fixd. If there are some lines containing port 2092, and d3fixd is _not_ running (i.e. crashed or killed), then you should run \"# iptables -t mangle -F\", which will flush the mangle table. Otherwise all packets addressed to the descent port 2092 will remain in the ip packet queue and wait there forever since there is no d3fixd which handles them.

Of course, if you just close the d3fixd (signal INT) by hitting CTRL-C or calling \"kill\" without an explicit signal, it should clean up by himself, as he prints \"stopping filter.

Xamindar · Post by **Xamindar** » Sat Apr 08, 2006 2:23 am

Ok thanks for the info. I had thought of something like that but didn't bother investigating it because I didn't have iptables installed. So I just installed it and will check it out if this happens again.

Xamindar · Post by **Xamindar** » Sun Apr 09, 2006 4:18 pm

Hey Munk, D3 Retribution still gives levels don't match errors. I was trying to join a coop game. How can I go about adding the retribution levels to d3fixd?

Munk · Post by **Munk** » Fri Apr 14, 2006 9:14 am

Sorry for my late response. This forum might be stucked. This thread never bubbles up in the thread list when a new post arrives, nor does it show the correct date of last post (just shows \"Sat Mar 25, 2006 2:30 pm\"). The mail notify doesn't work also... so there's no real chance to see when something is posted here.

I'm sorry Xamindar, D3-Retribution or Mercenary does not run on VEX-Servers. Don't know why it's not running - so no checksums for that mission.

iten · Post by **iten** » Sat May 20, 2006 9:06 pm

Amazing work on this.

I installed this a while ago, but only a couple weeks ago got it working--it turned out that there was a version incompatibility with the perl Storable module. It may or may not be because I have a 64-bit system, but either way the checksum file didn't work for me.

I found a way to convert it, though, so if anyone has any problems mentioning \"Storable,\" try downloading this checksum file instead.

http://carolnrob.net/~jol/checksums

Thanks to Munk for his great work.

Munk · Post by **Munk** » Sun Jul 02, 2006 1:33 pm

Nosferatu wrote:I was wondering if this could be used, or sometime in the future be used, to run a linux server that does allows other windows games to connect to it.

There's a version ready which can run on a linux gameserver to allow all those windows-users to join.
Unfortunatly since my ubuntu upgrade, my perl compiler broke. So what I can give you is the perl script - no binary.
If you are brave enough to install a approx. dozen of perl modules by hand, you could try it. Just PM me for instructions.

FunkyStickman · Post by **FunkyStickman** » Sun Jul 09, 2006 3:51 pm

Munk, did we ever tell you how much we appreciate this? You're awesome. I haven't gotten to play D3 in a few weeks (real life sucks, don't it?) but I'm planning on upgrading my main system, and when I do, I'll be in the mines almost every night!

Thanks again.

MoonSire · Post by **MoonSire** » Sat Feb 24, 2007 12:02 pm

Hi.

Did you manage to get the linux server fix to work? I would really appreciate it if you could upload it, me and a couple of friends have recently discovered descent3 and we play it at least an hour a day

Thanks in advance!
/MoonSire

Munk · Post by **Munk** » Sun Feb 25, 2007 2:54 am

You can try the 2.0 version with server support by running it in perl:

http://munk.vex-server.de/d3fix/d3fixd.pl

I have no working perl compiler anymore, so basically you will need to install the perl modules by hand.

Do_Checkor · Post by **Do_Checkor** » Mon Feb 26, 2007 7:44 am

Uhmmm. Sticky?

MD-2389 · Post by **MD-2389** » Mon Feb 26, 2007 11:42 am

I would sticky it, but it seams the board is having issues again.

edit This thread is linked in the bugfixes announcement thread.

MoonSire · Post by **MoonSire** » Fri Apr 06, 2007 10:45 am

Hi.

Thanks for your tool! It's really good, but I need the checksum generator program, I have some levels that I would like to add.

/MoonSire

Munk · Post by **Munk** » Fri Apr 13, 2007 4:17 pm

Well, I've written a small perl script you can run to add checksums for new missions to the database.

http://munk.vex-server.de/d3fix/d3fixadd.pl

(you will need perl and have to install the Storable module: http://search.cpan.org/CPAN/authors/id/ ... .16.tar.gz)

How to add new checksums of a mission to the database: (it's a bit tricky)

0. Make sure d3fixd is not running, by killing it gently (with SIGTERM).

1. Find or setup a Windows Descent3 Server (or Mac) running that specific mission.

2. Fire up d3fixd without sending it to background (by omitting the \"&\"), so you can see it's output in the console.

3. Start your Loki Descent and try to connect to that server. If you get the \"Levels Don't Match\" error message, quit (or minimize) Loki to see at the output of d3fixd. It will tell you the catched checksum by the message \"read Checksum 12345\". This is the checksum as it is reported from the windows server.

4. Open a second console, and run d3fixadd.pl with \"d3fixadd.pl 12345 +1\".
It will alter the d3fixd checksum database to report a new checksum to your Loki client which is 1 higher (hence the \"+1\").
You do not need to restart d3fixd, it will load the new checksums by itself.

5. Try again connecting with Loki to the Gameserver. Hopefully you can now connect.
If you cannot, repeat step 4 with a different adjustment (i.e. try \"-1\", \"+2\", \"-2\", ...).
The adjustments to the checksums are typically small (up to about +/- 4), but smaller adjustmends have higher probability of success, so start with the lower ones.

6. If you can connect, well done!... But: This checksum will only work for this specific ship you selected. So you need to do it again with Pyro-GL, Phoenix, Magnum-AHT and Black-Pyro.
Both, Checksum and Adjustment will change for each ship, so after changing the ship you need a look at d3fixd to get the new checksum, and then try new adjustments to it. (first try as adjustment +0, maybe you do not need one).

7. If you cannot find a suitable adjustment, ask a friend to setup a Loki Descent 3 Server with the same mission. Connect to it, and look at the output of d3fixd. It will now report (as you connect to a Linux Descent3 Server) the Linux checksum. The Difference <Linux Checksum> - <Windows Checksum> is the adjustment you need to specify to d3fixadd.pl.

8. Finally if you managed to get all adjustments for the specific mission and for all 4 ships (or at least the 3 basic ships without Black-Pyro), you can mail me <munk@vexclan.de> your checksum database (located at /usr/local/share/d3fix/checksums), and I will put it on my website.

P.S.: Maybe step 7 is the fastest way to get to the checksums, but you need lots of ressources, (since you cannot run loki client and loki server at the same time on the same machine).

P.P.S.: You should run d3fixadd.pl as root user, since it needs to modify /usr/local/share/d3fix/checksums, which is write-protected. Also for d3fixd to reload his checksums, it needs to send SIGHUP to d3fixd. Since d3fixd is owned by root, only root can do that.

FunkyStickman · Post by **FunkyStickman** » Tue Apr 17, 2007 5:32 am

Munk, thanks again for your hard work. I'll try to set aside some time to try this sometime this week. I've even got a spare Linux server to work with, so should be fun!

The Lion · Post by **The Lion** » Tue Apr 17, 2007 8:23 am

Why is it impossible to run a loki server and a loki client on the same comp?

Munk · Post by **Munk** » Wed Apr 18, 2007 5:20 am

because both try to allocate the udp listening port 2092.
Loki didn't implement an option to change that to another port.

The Lion · Post by **The Lion** » Wed Apr 18, 2007 8:59 am

Ok, but still... it looks like a simple LD_PRELOAD job to me.

MoonSire · Post by **MoonSire** » Sat Apr 21, 2007 5:38 am

Thank you so much!! Your work is very appreciated!!

The Lion · Post by **The Lion** » Sat Apr 21, 2007 10:08 am

The Lion wrote:Ok, but still... it looks like a simple LD_PRELOAD job to me.

Job done btw.

MoonSire · Post by **MoonSire** » Sat Apr 28, 2007 5:03 am

@TheLion

woohoo! Thank you! So many talanted people and all willing to help! This really made my day! Thanks!

The Lion · Post by **The Lion** » Sat Apr 28, 2007 9:31 am

You're welcome.

It was an easy job though, as I expected.

Arcalyth · Post by **Arcalyth** » Mon May 28, 2012 3:48 pm

Sorry for the bump, but can anyone mirror the fix? Munk's site 404s and I'd love to play something other than the campaign!

Munk · Post by **Munk** » Wed May 30, 2012 12:17 am

I'm ashamed it's 404, i have no clue how that happened (VEX changed servers twice since the release).

Searching the web I found the perl script
http://odf.sourceforge.net/downloads/descent3/d3fixd.pl
but you will also need the checksum database.

Things on my todo list (after finishing studies in a month) is a better version of that fix based on LD_PRELOAD hacks instead of IP mangling. It would not need any root privileges...

If you can wait a few weeks, I would need some help in testing.

flip · Post by **flip** » Wed May 30, 2012 8:26 am

http://www.filehosting.org/file/details ... les.tar.gz

http://www.filehosting.org/file/details ... 1.6.tgz.gz

Arcalyth · Post by **Arcalyth** » Wed May 30, 2012 9:52 am

Thanks flip. Now to get it working... having trouble getting IPTables::IPv4 to install properly >_<

Munk, I'd be happy to assist you in testing. Gmail: Arcalyth
Go ahead and send me some mail when you're ready.

flip · Post by **flip** » Wed May 30, 2012 10:52 am

NP, over the last 6 years I think I downloaded everything Descent related I could find on the web

Arcalyth · Post by **Arcalyth** » Thu May 31, 2012 1:02 pm

I haven't been able to get d3fixd working because IPTables::IPv4 module refuses to install. Since I'm impatient, I figured I'd try to write a python version since the iptables module for python works. To do so, I need the original checksums file. I tried to use Storable to deserialize the one in the .tar.gz, but the new version of Storable can't read it and the old one that you linked on Page 2 won't compile either.

So, do you have the original non-serialized checksums?

Fix for Linux Loki Checksum bug

linux server

Checksum generator

Re:

Re: Fix for Linux Loki Checksum bug

Re: Fix for Linux Loki Checksum bug

Re: Fix for Linux Loki Checksum bug

Re: Fix for Linux Loki Checksum bug

Re: Fix for Linux Loki Checksum bug

Re: Fix for Linux Loki Checksum bug