[Home] [Downloads] [Search] [Help/forum]


Register forum user name Search FAQ

Gammon Forum

Notice: Any messages purporting to come from this site telling you that your password has expired, or that you need to "verify" your details, making threats, or asking for money, are spam. We do not email users with any such messages. If you have lost your password you can obtain a new one by using the password reset link.
[Folder]  Entire forum
-> [Folder]  MUSHclient
. -> [Folder]  General
. . -> [Subject]  Disconnect Signal to Game

Disconnect Signal to Game

You need to log onto the forum to reply or create new threads.

  [Refresh] Refresh page


Posted by MUSHuser   (12 posts)  [Biography] bio
Date Tue 18 Jun 2024 11:40 PM (UTC)
Message
When you select "Disconnect" in MUSHclient, a disconnect signal gets sent to the game. I know because no matter how fast I log back in, it starts a new session. This is normal behavior.

I play on a laptop and mostly prefer to use Ethernet. If I switch to Wi-Fi by toggling the Windows network adapters, I notice that in an overwhelming majority of the time, a new session starts upon return. However, if there is a normal network outage (ISP, router problems, etc.), I can take over 10 minutes to reconnect and still be in the same session.

My assumption is that MUSHclient detects the changes to the network adapters and sends a disconnect signal to the game. Is there a way to prevent sending a disconnect signal to the game completely? For example, it would be cool if I could use the "Disconnect" button to temporarily leave the game and restart my computer and come back to the same session. Currently I have to resort to things like ending the MUSHclient process in Task Manager or rebooting my router to bypass the disconnect signal being sent.

Thanks for any possible suggestions!
[Go to top] top

Posted by Nick Gammon   Australia  (23,019 posts)  [Biography] bio   Forum Administrator
Date Reply #1 on Wed 19 Jun 2024 03:55 AM (UTC)
Message
This doesn't totally follow.

If you change network adapters there is no path for MUSHclient to send a "disconnect signal". It would be like trying to tell someone the phone has hung up after you got disconnected. Since you are disconnected you can't do that.

It is more likely that the game server hasn't noticed you disconnecting immediately (possibly because it didn't have anything to send you). That might explain why sometimes you can reconnect quickly and sometimes not.

But if the game is trying to tell you something (ie. sending packets over the network) and they get rejected due to the connection being dropped, then the game would probably terminate that session.

- Nick Gammon

www.gammon.com.au, www.mushclient.com
[Go to top] top

Posted by MUSHuser   (12 posts)  [Biography] bio
Date Reply #2 on Wed 19 Jun 2024 09:04 AM (UTC)
Message
I do not know what Windows actually does but my guess is that it gracefully terminates connections when toggling the network adapters. Yanking an Ethernet cord or restarting a router is not so graceful so there is truly no path to send the signal.

But, in general, I assume there is no way to prevent the "disconnect signal" if I simply exit or restart MUSHclient? Thank you again!
[Go to top] top

Posted by Fiendish   USA  (2,525 posts)  [Biography] bio   Global Moderator
Date Reply #3 on Thu 20 Jun 2024 09:15 PM (UTC)

Amended on Fri 21 Jun 2024 02:53 PM (UTC) by Fiendish

Message
Quote:
When you select "Disconnect" in MUSHclient, a disconnect signal gets sent to the game.

I believe MUSHclient has nothing to do with this. It's just using a TCP socket provided by Windows.

Quote:
I know because no matter how fast I log back in, it starts a new session.

There are many other ways this can happen that are not explicit disconnect signals, governed mostly by not resuming the TCP sequence and just generating a new random initial sequence number rather than by explicitly finalizing anything.

Quote:
My assumption is that MUSHclient detects the changes to the network adapters and sends a disconnect signal to the game.

Huh? Chaos would ensue if anyone could send a disconnect signal for some other unrelated network adapter.

Quote:
it would be cool if I could use the "Disconnect" button to temporarily leave the game and restart my computer and come back to the same session

This would require bypassing the standard Windows socket interface to persist raw socket metadata to disk and then restore it later, which would be super abnormal network behavior that Windows does not want you to do.

https://github.com/fiendish/aardwolfclientpackage
[Go to top] top

Posted by MUSHuser   (12 posts)  [Biography] bio
Date Reply #4 on Fri 21 Jun 2024 09:01 AM (UTC)
Message
Fiendish said:

Huh? Chaos would ensue if anyone could send a disconnect signal for some other unrelated network adapter.

If it is just a TCP socket provided by Windows as you said, it makes sense that toggling the network adapter gracefully terminates all activate TCP sockets first. Again, I am not sure if that is exactly what Windows does, but I think it is a valid theory.

Fiendish said:

This would require bypassing the standard Windows socket interface to persist raw socket metadata to disk and then restore it later, which would be super abnormal network behavior that Windows does not want you to do.

I guess I was unclear. I do not mean the TCP socket's session; I mean the game's session. Like I said, I can consistently do this by unplugging my Ethernet cord or restarting my router before closing MUSHclient. If I return before the game realizes I am gone (Nick's example), I will return to the same session. I just disconnected for 11 minutes and 41 seconds via this method and returned without an issue. If I exit MUSHclient gracefully, it does not matter if I return within 5 seconds because the previous session was already terminated.
[Go to top] top

Posted by Fiendish   USA  (2,525 posts)  [Biography] bio   Global Moderator
Date Reply #5 on Fri 21 Jun 2024 03:07 PM (UTC)

Amended on Fri 21 Jun 2024 03:27 PM (UTC) by Fiendish

Message
MUSHuser said:

I guess I was unclear. I do not mean the TCP socket's session; I mean the game's session. Like I said, I can consistently do this by unplugging my Ethernet cord or restarting my router before closing MUSHclient. If I return before the game realizes I am gone (Nick's example), I will return to the same session.


Why/how would the game session continue without continuing the underlying TCP session? If I were writing a server, I certainly would not let some random other TCP session resume an unaffiliated game session without forcing a new login. I think you'd need to persist the previous TCP metadata.

Anecdotally, I cannot get around logging my character in again to Aardwolf if I force kill my local program, regardless of what I do with my network, because the program is always going to generate a new TCP initial sequence number the next time I try to connect with it, and the server rightly does not recognize that new sequence as being a continuation of my previous session.

Quote:
If it is just a TCP socket provided by Windows as you said, it makes sense that toggling the network adapter gracefully terminates all activate TCP sockets first.

I don't think Windows does anything to the socket when you turn the network interface off. I do think it happens when the socket is closed because MUSHclient closes it or exits, but more importantly I also think it will not transfer a TCP session from one network interface to another network interface or across reboots. But I can easily turn my wifi off and then back on without being disconnected from the game. I just can't switch from wifi to wired without losing my connection because that's a different interface than before.

https://github.com/fiendish/aardwolfclientpackage
[Go to top] top

Posted by MUSHuser   (12 posts)  [Biography] bio
Date Reply #6 on Sat 22 Jun 2024 09:34 AM (UTC)

Amended on Sat 22 Jun 2024 09:35 AM (UTC) by MUSHuser

Message
Fiendish said:

Anecdotally, I cannot get around logging my character in again to Aardwolf if I force kill my local program, regardless of what I do with my network, because the program is always going to generate a new TCP initial sequence number the next time I try to connect with it, and the server rightly does not recognize that new sequence as being a continuation of my previous session.

Sorry, I am still not explaining it clearly. Maybe I should not use the term session but "character state". When you are logged in, people can communicate and interact with you. If your network drops, they can still do that. When you log back in, you can see your chat history of when you disconnected (if Aardwolf has that functionality). Any other states your character was in persists. However, if you exit MUSHclient gracefully, your character is disconnected as if you quit. People cannot communicate with you. When you return, the state of your character is as if you quit and logged back in.

Anyhow, I was expecting this to be a shot in the dark. I appreciate the response!
[Go to top] top

Posted by Fiendish   USA  (2,525 posts)  [Biography] bio   Global Moderator
Date Reply #7 on Sun 23 Jun 2024 02:50 AM (UTC)

Amended on Sun 23 Jun 2024 03:27 AM (UTC) by Fiendish

Message
Yeah, it's very likely that MUSHclient closing the socket on disconnect causes the system to then transmit the TCP session end signal, which probably then causes the server to quit your character.

Teeeeechnically, it might be possible to avoid calling Close on the socket here and only call ShutDown to put it into a non-communicative state without explicitly terminating: https://github.com/nickgammon/mushclient/blob/c93ddf9a97ddd401f854cba74140b847f684e640/Utilities.cpp#L1100-L1104

Unfortunately Microsoft says in https://learn.microsoft.com/en-us/cpp/mfc/reference/casyncsocket-class?view=msvc-170#remarks-34 that it's unsafe to do that, because they provide no guarantee that a socket can be safely reactivated afterward without creating a new one. Why that is, or under what circumstances, I have no idea.

https://github.com/fiendish/aardwolfclientpackage
[Go to top] top

The dates and times for posts above are shown in Universal Co-ordinated Time (UTC).

To show them in your local time you can join the forum, and then set the 'time correction' field in your profile to the number of hours difference between your location and UTC time.


975 views.

You need to log onto the forum to reply or create new threads.

  [Refresh] Refresh page

Go to topic:           Search the forum


[Go to top] top

Quick links: MUSHclient. MUSHclient help. Forum shortcuts. Posting templates. Lua modules. Lua documentation.

Information and images on this site are licensed under the Creative Commons Attribution 3.0 Australia License unless stated otherwise.

[Home]


Written by Nick Gammon - 5K   profile for Nick Gammon on Stack Exchange, a network of free, community-driven Q&A sites   Marriage equality

Comments to: Gammon Software support
[RH click to get RSS URL] Forum RSS feed ( https://gammon.com.au/rss/forum.xml )

[Best viewed with any browser - 2K]    [Hosted at HostDash]