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Save/load game bug?

Posted: Fri Dec 19, 2014 5:04 am
by Zgokee
Hello, I was playing a solo map, SL1, on a USA server some time back. I decided to take a break because i was stuck on a part. So, few days later I wanted to finish it. I join a USA server and type in the great /load command as i usually do. I get an error saying, "You have to be on the 'GER' server to load this savegame." Hm, i am pretty i played a two player map afterwards i thought with a friend. Oh well, thought nothing of it. Maybe i am going crazy. Today, Dinner had the same problem with a different solo map.

Is there a legitimate reason for this? :(

Thanks in advance.

Re: Save/load game bug?

Posted: Fri Dec 19, 2014 7:50 am
by laxa
An exploit was found with save/load, and the only solution deen found so far is to let save/load only on ger afaik.

Re: Save/load game bug?

Posted: Fri Dec 19, 2014 11:34 am
by deen
Indeed, there was an exploit using savegames. The solution is that you can only load on the server where you saved (same country). Unfortunately I didn't record this information before, so I had to set GER as the default server. To restore your savegame on USA:
1. go to a GER server and /load MYCODE
2. /save USA MYCODE
3. go to a USA server and /load MYCODE

Re: Save/load game bug?

Posted: Fri Dec 19, 2014 5:04 pm
by Zgokee
That is interesting. Would you mind explaining the exploit?
Thank you for the solution deen!

Re: Save/load game bug?

Posted: Fri Dec 19, 2014 6:38 pm
by laxa
If I understood it correctly, the exploit is like that :

- save at some point of the run
- wait for the save to be spread to another server
- then you can load the save on 2 different servers
- you can then multiply your saves

Servers = different country server.

Re: Save/load game bug?

Posted: Mon Dec 22, 2014 4:17 pm
by Grim_Fandango
If we have to go through this, could we at least get a list of the codes DDNet recognizes for the different countries...? >.>

On South African servers for example, I've tried getting mine over using "/save SA xyz" and it just saves as "SA xyz". "/save South Africa xyz" doesn't work either.

:( :( :(

Re: Save/load game bug?

Posted: Mon Dec 22, 2014 4:19 pm
by deen
Grim_Fandango wrote:If we have to go through this, could we at least get a list of the codes DDNet recognizes for the different countries...? >.>

On South African servers for example, I've tried getting mine over using "/save SA xyz" and it just saves as "SA xyz". "/save South Africa xyz" doesn't work either.

:( :( :(
Yeah, I'm really sorry. The only choice was to do this or disable save altogether. The codes for each country are the 3 letter codes, so ZAF for South Africa, also GER, USA, RUS, CAN, CHN, CHL, BRA.

Re: Save/load game bug?

Posted: Mon Dec 22, 2014 7:51 pm
by HMH
If I got this right it is a problem about sql-access, is it not ? Well, if it is I think I know how to fix it.

Re: Save/load game bug?

Posted: Mon Dec 22, 2014 9:47 pm
by deen
HMH wrote:If I got this right it is a problem about sql-access, is it not ? Well, if it is I think I know how to fix it.
On most DDNet countries a separate MariaDB (MySQL) database is running. They are all connected in a big replication circle. When you make a save it is stored on your country's database first, then replicated to the other ones. When you load, the same happens, but with a remove instead of add. So this is how they cheated: They went to 2 separate countries at the same time which have quite some ping between them, and loaded the save on both at the same time. Now they have made 2 saves from 1 and can try the map twice from that position. Great for cheating faily maps. Can be repeated to get more than 2 saves.

Re: Save/load game bug?

Posted: Wed Dec 24, 2014 5:36 pm
by Grim_Fandango
deen wrote:
Grim_Fandango wrote:If we have to go through this, could we at least get a list of the codes DDNet recognizes for the different countries...? >.>

On South African servers for example, I've tried getting mine over using "/save SA xyz" and it just saves as "SA xyz". "/save South Africa xyz" doesn't work either.

:( :( :(
Yeah, I'm really sorry. The only choice was to do this or disable save altogether. The codes for each country are the 3 letter codes, so ZAF for South Africa, also GER, USA, RUS, CAN, CHN, CHL, BRA.
Ah, thanks deen!