* Codechange: [Network] split CloseSocket and CloseConnection more clearly
- CloseSocket now closes the actual OS socket.
- CloseConnection frees up the resources to just before CloseSocket.
- dtors call CloseSocket / CloseConnection where needed.
In the destructors of many of the network related classes Close() is called, just like the
top class in that hierarchy. However, due to virtual functions getting resolved statically
in the destructor it would always call the empty Close() of the top class.
Document the other cases where a virtual call is resolved statically.
It now follows very simple rules:
0 - Fatal, user should know about this
1 - Error, but we are recovering
2 - Warning, wrong but okay if you don't know
3 - Info, information you might care about
4 -
5 - Debug #1 - High level debug messages
6 - Debug #2 - Low level debug messages
7 - Trace information
The code mixed up "client has quit but we already told everyone"
with "client lost connection, handle this".
Split up those two signals:
- CLIENT_QUIT means we told everyone and the connection is now dead
- CONNECTION_LIST means we should tell everyone we lost a client
This meant that on opening the Multiplayer window, if you had more
than one server configured, it would one by one cancel all pending
queries and send a new. Result: only the last server was updated.
The most common case never needs access to it anymore. Make the
one exception to this explicit. This means the fact that we
store it is now an implementation detail.
Hostnames like "content.openttd.org" resolve into multiple IPv4 and IPv6.
It is possible that either of the IPs is not working, either due to
a poorly configured OS (having IPv6 but no valid route), broken network
paths, or a service that is temporary unavailable.
Instead of trying the IPs one by one, waiting for a 3s timeout between
each, be a bit more like browsers, and stack attempts on top of each
other with slight delays. This is called Happy Eyebells.
Initially, try the first IPv6 address. If within 250ms there is no
connection yet, try the first IPv4 address. 250ms later, try the
second IPv6 address, etc, till all addresses are tried.
If any connection is created, abort all the other (pending) connections
and use the one that is created. If all fail 3s after the last connect(),
trigger a timeout for all.
We now resolve the connection_string to a NetworkAddress in a much
later state. This means there are fewer places constructing a NetworkAddress.
The main benefit of this is in later PRs that introduce different types
of NetworkAddresses. Storing this in things like NetworkGameList is
rather complex, especially as NetworkAddress has to be mutable at all
times.
Additionally, the NetworkAddress is a complex object to store simple
information: how to connect to this server.
Split the updating in a "static" version that only needs to be called when a new map is loaded or some settings are changed, and a "dynamic" version that updates everything that changes regularly such as the current game date or the number of spectators.
Under normal circumstances the server's ID is 32 characters excluding '\0', however this can be changed at the server. This ID is sent to the server for company name hashing. The client reads it into a statically allocated buffer of 33 bytes, but fills only the bytes it received from the server. However, the hash assumes all 33 bytes are set, thus potentially reading uninitialized data, or a part of the server ID of a previous game in the hashing routine.
It is still reading from memory assigned to the server ID, so nothing bad happens, except that company passwords might not work correctly.
One could join a network game from within an already running network game. This would call a NetworkDisconnect, but keeps the UI alive. If, during that process the join is aborted, e.g. by cancelling on a password dialog, you would still be in your network game but also get shown the server list.
Solve all the underlying problems by falling back to the main UI when (re)connecting to a(nother) server.
This means that pressing Refresh button and adding servers manually
now uses TCP.
The master-server and initial scan are still UDP as they will be
replaced by Game Coordinator; no need to change this now.
If we query a server that is too old, show a proper warning to the
user informing him the server is too old.
rubidium42
Patric Stout
William Davis
rubidium42
Peter Nelson