This method doesn't require port-forwarding to be used, and works for
most common NAT routers in home setups. But, for sure it doesn't work
for all setups, and not everyone will be able to use this.
Every outgoing connection, either TCP or UDP, triggered
NetworkInitialize(), which triggered NetworkUDPInitialize() which
first closes all connections.
Now the problem was that "Search LAN games" found a server, added
it to the list, after which (over TCP) it queries the server. This
closes all UDP sockets (as that makes sense, I guess?), while the
UDP was still reading from it.
Solve this by simply stop initializing UDP every time we make an
outgoing TCP connection; instead only do it on start-up.
In this mode you do register to the Game Coordinator, but your
server will not show up in the public server listing. You can give
your friends the invite code of the server with which they can
join.
This removes the need to know a server IP to join it. Invite codes
are small (~7 characters) indentifiers for servers, which can be
exchanged with other players to join the servers.
Normally TCPConnecter will do a DNS resolving of the connection_string
and connect to it. But for SERVER_ADDRESS_INVITE_CODE this is different:
the Game Coordinator does the "resolving".
This means we need to allow TCPConnecter to not setup a connection
and allow it to be told when a connection has been setup by an external
(to TCPConnecter) part of the code. We do this by telling the (active)
socket for the connection.
This means the rest of the code doesn't need to know the TCPConnecter
is not doing a simple resolve+connect. The rest of the code only
cares the connection is established; not how it was established.
OTTD_COORDINATOR_CS for the game coordinator defaults to coordinator.openttd.org:3976
OTTD_CONTENT_SERVER_CS for the content server defaults to content.openttd.org:3978
OTTD_CONTENT_MIRROR_CS for the content mirror server defaults to binaries.openttd.org:80
Rename the zero-parameter NetworkValidateClientName to NetworkValidateOurClientName to make it clearer it is performed on our client name, and to make it a non-overloaded function to aid with the variant being added a few commits later
Patric Stout
Rubidium
Stephan
TELK
SamuXarick