Thanks to @Jupeyy for figuring out this bug.
Previously, the client would send the request for server info and the
server info ping packet with the same token, making the answer
indistinguishable from each other. Fix this by generating a token that
won't collide.
Fixes#3862.
Change filename `serverlist_urls.cfg` → `ddnet-serverlist-urls.cfg`,
change filename `cache.sqlite3` → `ddnet-cache.sqlite3`, add `const` to
a variable and change pings to just before multiples of 100.
Fixes#3853.
Automatically determine the approximate location of the client by
including that info in the already fetched https://info2.ddnet.tw/info.
Can be overridden using the the config variable `br_location`.
Summary
=======
The idea of this is that clients will not have to ping each server for
server infos which takes long, leaks the client's IP address even to
servers the user does not join and is a DoS vector of the game servers
for attackers.
For the Internet, DDNet and KoG tab, the server list is entirely fetched
from the master server, filtering out servers that don't belong into the
list.
The favorites tab is also supposed to work that way, except for servers
that are marked as "also ping this server if it's not in the master
server list".
The LAN tab continues to broadcast the server info packet to find
servers in the LAN.
How does it work?
=================
The client ships with a list of master server list URLs. On first start,
the client checks which of these work and selects the fastest one.
Querying the server list is a HTTP GET request on that URL. The
response is a JSON document that contains server infos, server addresses
as URLs and an approximate location.
It can also contain a legacy server list which is a list of bare IP
addresses similar to the functionality the old master servers provided
via UDP. This allows us to backtrack on the larger update if it won't
work out.
Lost functionality
==================
(also known as user-visible changes)
Since the client doesn't ping each server in the list anymore, it has no
way of knowing its latency to the servers.
This is alleviated a bit by providing an approximate location for each
server (continent) so the client only has to know its own location for
approximating pings.
src/engine/client/serverbrowser.cpp:295:88: runtime error: index 64 out of bounds for type 'CServerInfo::CClient [64]'
#0 0x565020e035bd in CServerBrowser::Filter() /media/ddnet/src/engine/client/serverbrowser.cpp:295:128
#1 0x565020e053b3 in CServerBrowser::Sort() /media/ddnet/src/engine/client/serverbrowser.cpp:352:2
#2 0x565020e0c364 in CServerBrowser::Set(NETADDR const&, int, int, CServerInfo const*) /media/ddnet/src/engine/client/serverbrowser.cpp:620:2
#3 0x565020cf9854 in CClient::ProcessServerInfo(int, NETADDR*, void const*, int) /media/ddnet/src/engine/client/client.cpp:1524:20
#4 0x565020cf8132 in CClient::ProcessConnlessPacket(CNetChunk*) /media/ddnet/src/engine/client/client.cpp:1357:4
#5 0x565020d11656 in CClient::PumpNetwork() /media/ddnet/src/engine/client/client.cpp:2575:5
#6 0x565020d1ba21 in CClient::Update() /media/ddnet/src/engine/client/client.cpp:2856:2
#7 0x565020d26efe in CClient::Run() /media/ddnet/src/engine/client/client.cpp:3237:4
#8 0x565020d48b2e in main /media/ddnet/src/engine/client/client.cpp:4341:11
#9 0x7f4311524151 in __libc_start_main (/usr/lib/libc.so.6+0x28151)
#10 0x565020a95e0d in _start (/media/ddnet/DDNet+0x705e0d)
src/base/system.c:261:15: runtime error: null pointer passed as argument 2, which is declared to never be null
/usr/include/string.h:44:28: note: nonnull attribute specified here
#0 0x5651235308dc in mem_copy /media/ddnet/src/base/system.c:261:2
#1 0x56512375218d in CServerBrowser::Add(NETADDR const&) /media/ddnet/src/engine/client/serverbrowser.cpp:503:3
#2 0x565123752f6a in CServerBrowser::Set(NETADDR const&, int, int, CServerInfo const*) /media/ddnet/src/engine/client/serverbrowser.cpp:548:13
#3 0x5651237564cb in CServerBrowser::Refresh(int) /media/ddnet/src/engine/client/serverbrowser.cpp:705:6
#4 0x5651239a32f8 in CMenus::Render() /media/ddnet/src/game/client/components/menus.cpp:1164:21
#5 0x5651239bd331 in CMenus::OnRender() /media/ddnet/src/game/client/components/menus.cpp:2338:2
#6 0x565123b878f6 in CGameClient::OnRender() /media/ddnet/src/game/client/gameclient.cpp:676:28
#7 0x56512363b5ee in CClient::Render() /media/ddnet/src/engine/client/client.cpp:1134:16
#8 0x56512367095f in CClient::Run() /media/ddnet/src/engine/client/client.cpp:3285:7
#9 0x565123690b7e in main /media/ddnet/src/engine/client/client.cpp:4341:11
#10 0x7fa8487e8151 in __libc_start_main (/usr/lib/libc.so.6+0x28151)
#11 0x5651233dde0d in _start (/media/ddnet/DDNet+0x705e0d)
Purely automatic change. In case of conflict with this change, apply the
other change and rerun the formatting to restore it:
$ python scripts/fix_style.py
As suggested by BannZay on Discord. We scale down when we notice that
no responses arrive. The idea is that player's internet has become
faster than when DDNet started, so increasing the default is ok.
2715: Fix server responses handling in game browser r=heinrich5991 a=BannZay
Fixes all problems for #2620
Explanations of existed problems:
Lan has non expected servers because we were creating browser entry regardless token check
DDNet tab has ping 0 for servers as we weren`t rejecting previous refresh responses
Co-authored-by: Andrii <bannzay3@gmail.com>
One from each country and so on instead of doing one country fully first
before moving to the next. This makes loading servers like Japan and AUS
much faster since they're at the back of the list. This also reduces the
peak number of packets sent to each IP at once.
