Status host uses net.port by default, add UPnP port forwarding option (#2237)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Robust.Server/ServerStatus/StatusHost.cs

@@ -156,6 +156,9 @@ namespace Robust.Server.ServerStatus
 
         private void RegisterCVars()
         {
+            // Set status host binding to match network manager by default
+            SetCVarIfUnmodified(CVars.StatusBind, $"*:{_netManager.Port}");
+
             // Check build.json
             var path = PathHelpers.ExecutableRelativeFile("build.json");
             if (File.Exists(path))

Robust.Server/server_config.toml

@@ -1,4 +1,7 @@
-
+# Welcome to the example configuration file!
+# Remember that if this is in bin/Content.Server or such, it may be overwritten on build.
+# Consider copying it and using the --config-file and --data-dir options.
+
 [log]
 path = "logs"
 format = "log_%(date)s-%(time)s.txt"
@@ -9,19 +12,27 @@ enabled = false
 tickrate = 60
 port = 1212
 bindto = "::,0.0.0.0"
+# Automatic port forwarding!
+# Disabled by default because you may not want to do this.
+# upnp = true
 
-# The status server is the TCP side, used by the launcher to determine engine version, etc.
 [status]
+# The status server is the TCP side, used by the launcher to determine engine version, etc.
+# To be clear: Disabling it makes the launcher unable to connect!
 enabled = true
-bind = "*:1212"
+
+# This is the address and port the status server binds to.
+# The port is by default set based on net.port so it will follow what you set there.
+# bind = "*:1212"
 
 # This is the address of the SS14 server as the launcher uses it.
-# This is only needed if you're proxying the status HTTP server.
+# This is only needed if you're proxying the status HTTP server -
+#  by default the launcher will assume the address and port match that of the status server.
 # connectaddress = "udp://localhost:1212"
 
 [game]
 hostname = "MyServer"
-# map = "maps/saltern.yml"
+# map = "Maps/saltern.yml"
 maxplayers = 64
 type = 1
 welcomemsg = "Welcome to the server!"
@@ -62,6 +73,7 @@ loginlocal = true
 
 # Build hash - this is a *capitalized* SHA256 hash of the client ZIP.
 # Optional in any case and automatically set if hosting a client ZIP.
+# This hash is an example only.
 # build = "E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855"
 
 [auth]

Robust.Shared/CVars.cs

@@ -113,6 +113,12 @@ namespace Robust.Shared
         public static readonly CVarDef<bool> NetEncrypt =
             CVarDef.Create("net.encrypt", true, CVar.CLIENTONLY);
 
+        /// <summary>
+        /// If true, use UPnP to automatically forward ports on startup if possible.
+        /// </summary>
+        public static readonly CVarDef<bool> NetUPnP =
+            CVarDef.Create("net.upnp", false, CVar.SERVERONLY);
+
         /**
          * SUS
          */
@@ -163,8 +169,10 @@ namespace Robust.Shared
         public static readonly CVarDef<bool> StatusEnabled =
             CVarDef.Create("status.enabled", true, CVar.ARCHIVE | CVar.SERVERONLY);
 
+        // Example: *:1212
+        // But this is now autogenerated by default to match NetPort
         public static readonly CVarDef<string> StatusBind =
-            CVarDef.Create("status.bind", "*:1212", CVar.ARCHIVE | CVar.SERVERONLY);
+            CVarDef.Create("status.bind", "", CVar.ARCHIVE | CVar.SERVERONLY);
 
         public static readonly CVarDef<int> StatusMaxConnections =
             CVarDef.Create("status.max_connections", 5, CVar.SERVERONLY);

Robust.Shared/Network/NetManager.Upnp.cs

@@ -0,0 +1,70 @@
+using System;
+using System.Linq;
+using System.Net.Sockets;
+using System.Threading;
+using Lidgren.Network;
+using Robust.Shared.Log;
+
+namespace Robust.Shared.Network;
+
+public partial class NetManager
+{
+    private void InitUpnp()
+    {
+        var sawmill = Logger.GetSawmill("net.upnp");
+        var port = Port;
+
+        var peers = _netPeers.Select(p => p.Peer).Where(p => p.Configuration.EnableUPnP).ToArray();
+        if (peers.Length == 0)
+        {
+            sawmill.Warning("Can't UPnP forward: No IPv4-compatible NetPeers available.");
+            return;
+        }
+
+        // We DON'T want to hold up the main server on this!
+        new Thread(() =>
+        {
+            try
+            {
+                foreach (var peer in peers)
+                {
+                    // The way the NetUPnP code is written, we're doing guesswork anyway
+                    // It seems to be that the assumption in regards to IPv6 is "what?" w/ UPnP????
+                    // ATTENTION FUTURE 20KDC (or anyone else who comes by):
+                    // IF YOU GET IPv6 FOR REALSIES, WORK OUT HOW TO DEAL W/ THIS!
+                    var upnp = peer.UPnP;
+                    while (upnp.Status == UPnPStatus.Discovering)
+                    {
+                        // Sleep while the network thread does the work
+                        NetUtility.Sleep(250);
+                    }
+
+                    // Clear these forwarding rules because we don't want any OTHER SS14 servers on our network (or different local IP addresses of ourself) conflicting
+                    upnp.DeleteForwardingRule(port, "UDP");
+                    upnp.DeleteForwardingRule(port, "TCP");
+                    var udpRes = upnp.ForwardPort(port, "RobustToolbox UDP", 0, "UDP");
+                    var tcpRes = upnp.ForwardPort(port, "RobustToolbox TCP", 0, "TCP");
+                    // Message needs to show in warning if something went wrong
+                    var message = $"UPnP setup for port {port} on peer {peer.Configuration.LocalAddress} results: TCP {tcpRes}, UDP {udpRes}";
+                    if (tcpRes && udpRes)
+                    {
+                        sawmill.Info(message);
+                    }
+                    else
+                    {
+                        sawmill.Warning(message);
+                    }
+                }
+            }
+            catch (Exception e)
+            {
+                sawmill.Warning($"UPnP threw an exception: {e}");
+            }
+        }).Start();
+    }
+
+    private static bool UpnpCompatible(NetPeerConfiguration cfg)
+    {
+        return cfg.LocalAddress.AddressFamily == AddressFamily.InterNetwork || cfg.DualStack;
+    }
+}

Robust.Shared/Network/NetManager.cs

@@ -349,6 +349,9 @@ namespace Robust.Shared.Network
                     config.DualStack = true;
                 }
 
+                if (UpnpCompatible(config))
+                    config.EnableUPnP = true;
+
                 var peer = IsServer ? (NetPeer) new NetServer(config) : new NetClient(config);
                 peer.Start();
                 _netPeers.Add(new NetPeerData(peer));
@@ -365,6 +368,9 @@ namespace Robust.Shared.Network
                 Logger.WarningS("net",
                     "IPv6 Dual Stack is enabled but no IPv6 addresses have been bound to. This will not work.");
             }
+
+            if (_config.GetCVar(CVars.NetUPnP))
+                InitUpnp();
         }
 
         /// <inheritdoc />