Local UDP socket listening problems

[oblalex]

Hello everyone! I've got a weird problem related to UDP. I have a dedicated game server (for IL-2 Sturmovik), which I run under Wine. This server has an opened UDP port which provides access to server's API.

The problem is when I run the server on localhost and try to send data to UDP socket it does not react. Wireshark shows that there was a packet transmission. Running Wine with WINEDEBUG="+winsock" shows that after sending data nothing happens. This issue is related only to localhost-to-localhost connection.

If I run server on Linux machine A (LM:A) and try to connect from Linux machine B (LM:B), then it's OK. If I try to connect to LM:A from Windows machine A (WM:A) then it's OK either.
If I run server on WM:A and try to connect from any LM, then it's OK. If I try to connect to WM:A from the same WM:A or from WM:B, then it's OK again.
So, the server itself seems to work correctly, but if I run server on LM:A and try to connect from the same LM:A then just nothing happens.

Please, any suggestions. This issue is very important for IL-2 community. Thanks in advance.

[dimesio]

Wine version? If it's not the latest development release, upgrade.

[oblalex]

wine version is 1.5.31. It's under Arch Linux with kernel 3.9.4-1. I've noticed this thing several months ago and have been hoping it was not wine-related.

[dimesio]

Sounds similar to this bug: http://bugs.winehq.org/show_bug.cgi?id=33008.

[oblalex]

yes, it seems to be similat, but I guess, it's not. It's traffic schema is very complex in comparison to my case. I got no NAT, no other networks and no filtering. everything is just straightforward. I've attached my traffic schemas. Problem is to connect from localhost to localhost on the same machine. Hope, this describes the situation a bit wider.

[dimesio]

File a bug.

Also, you mentioned you "noticed this thing several months ago." Does that mean it used to work? If so, please run a regression test.

[lahmbi5678]

Hi oblalex,

just an uneducated guess, in the past there used to be issues due to DNS resolution in some special cases, when the localhost entry in hosts file pointed to something invalid. Did you try to simply use IP numbers instead of DNS names or localhost?

[oblalex]

File a bug.

Also, you mentioned you "noticed this thing several months ago." Does that mean it used to work? If so, please run a regression test.

no, it does not. I meant that the 1st time I needed to connect to UDP socket running under wine was several months ago. the task was not urgent, so I kept searching alternative solutions from time to time. but now i gave up.

Did you try to simply use IP numbers instead of DNS names or localhost?

No DNS is used. I'm connecting straight to 127.0.0.1 or to local network IP (e.g. 129.168.1.36).

File a bug.

Please, could you explain, what does it mean?

[lahmbi5678]

"File a bug" means filing a bug report in wine's bugzilla, if you don't know where to find it, look at the top of this page.

It probably won't make a difference, but if you are connecting from a linux computer to itself, did you use 127.0.0.1 or something like 192.168.x.x ? Did you ping the same address, just to rule out typos? Which port are you using?

[oblalex]

When the machine is disconnected from network, I use 127.0.0.1. In other case I use 192.168.x.x (but I tried to use both of them). I do not see any need to ping localhost. I'm using port 10000.

[oblalex]

I've reported a bug and now it's resolved: http://bugs.winehq.org/show_bug.cgi?id=33791
Thanks for everyone!