Add support for direct connections

README.md

@@ -19,5 +19,6 @@ Here are all the parameters that you can set in the `FabricProxy-Lite.toml` conf
 | `hackOnlineMode` | `FABRIC_PROXY_HACK_ONLINE_MODE` | Allows connection through a proxy without disabling online-mode. | `true` | |
 | `hackEarlySend` | `FABRIC_PROXY_HACK_EARLY_SEND` | Fabric-API can't send packet before QUERY_START event, so player info(UUID) will not ready at QUERY_START event. Setting `hackEarlySend` to `true` will use mixin for early send packet to velocity. <br><br> This is **required** for some mods, such as LuckPerms. | `false` | |
 | `hackMessageChain` | `FABRIC_PROXY_HACK_MESSAGE_CHAIN` | This option fixes players being kicked for `Received chat packet with missing or invalid signature.` or `Chat message validation failure`, which only happens when the player switches to another server. <br><br> See [#30](/../../issues/30) and [#121](/../../discussions/121) for more info. | `false` | |
+| `allowDirectConnections` | `FABRIC_PROXY_ALLOW_DIRECT_CONNECTIONS` | Allow direct connections from clients without Velocity. When enabled, the mod will accept non-Velocity connections. | `false` | |
 | `disconnectMessage` | `FABRIC_PROXY_DISCONNECT_MESSAGE` | The custom disconnect/kick message for users that aren't connecting through Velocity. | `"This server requires you to connect with Velocity."` | |
 | `secret` | `FABRIC_PROXY_SECRET` | The Velocity forwarding secret. This should be the same random string as in Velocity's `forwarding.secret` file. <br><br> Alternatively you could set the `FABRIC_PROXY_SECRET_FILE` environment variable to read the secret from a file instead of config. | | ✓ |

src/main/java/one/oktw/ModConfig.java

@@ -13,6 +13,7 @@ public class ModConfig {
     private boolean hackOnlineMode = true;
     private boolean hackEarlySend = false;
     private boolean hackMessageChain = false;
+    private boolean allowDirectConnections = false;
     private String disconnectMessage = "This server requires you to connect with Velocity.";
     private String secret = "";
 
@@ -50,6 +51,11 @@ public static ModConfig load(Path configPath) {
             config.hackMessageChain = Boolean.parseBoolean(envHackMessageChain);
         }
 
+        String envAllowDirectConnections = System.getenv("FABRIC_PROXY_ALLOW_DIRECT_CONNECTIONS");
+        if (envAllowDirectConnections != null) {
+            config.allowDirectConnections = Boolean.parseBoolean(envAllowDirectConnections);
+        }
+
         String envDisconnectMessage = System.getenv("FABRIC_PROXY_DISCONNECT_MESSAGE");
         if (envDisconnectMessage != null) {
             config.disconnectMessage = envDisconnectMessage;
@@ -88,7 +94,11 @@ public boolean getHackMessageChain() {
         return hackMessageChain;
     }
 
+    public boolean getAllowDirectConnections() {
+        return allowDirectConnections;
+    }
+
     public String getSecret() {
         return secret;
     }
-}
+}

src/main/java/one/oktw/PacketHandler.java

@@ -22,41 +22,43 @@ class PacketHandler {
 
     void handleVelocityPacket(MinecraftServer server, ServerLoginPacketListenerImpl handler, boolean understood, FriendlyByteBuf buf, ServerLoginNetworking.LoginSynchronizer synchronizer, PacketSender ignored) {
         if (!understood) {
-            handler.disconnect(Component.nullToEmpty(config.getAbortedMessage()));
-            return;
-        }
-
-        synchronizer.waitFor(server.submit(() -> {
-            try {
-                if (!VelocityLib.checkIntegrity(buf)) {
+            if (!this.config.getAllowDirectConnections()) {
+                handler.disconnect(Component.nullToEmpty(config.getAbortedMessage()));
+                return;
+            }
+        } else {
+            synchronizer.waitFor(server.submit(() -> {
+                try {
+                    if (!VelocityLib.checkIntegrity(buf)) {
+                        handler.disconnect(Component.nullToEmpty("Unable to verify player details"));
+                        return;
+                    }
+                    VelocityLib.checkVersion(buf);
+                } catch (Throwable e) {
+                    LogManager.getLogger().error("Secret check failed.", e);
                     handler.disconnect(Component.nullToEmpty("Unable to verify player details"));
                     return;
                 }
-                VelocityLib.checkVersion(buf);
-            } catch (Throwable e) {
-                LogManager.getLogger().error("Secret check failed.", e);
-                handler.disconnect(Component.nullToEmpty("Unable to verify player details"));
-                return;
-            }
 
-            Connection connection = ((ServerLoginPacketListenerAccessor) handler).getConnection();
-            ((ConnectionAccessor) connection).setAddress(new java.net.InetSocketAddress(VelocityLib.readAddress(buf), ((java.net.InetSocketAddress) (connection.getRemoteAddress())).getPort()));
+                Connection connection = ((ServerLoginPacketListenerAccessor) handler).getConnection();
+                ((ConnectionAccessor) connection).setAddress(new java.net.InetSocketAddress(VelocityLib.readAddress(buf), ((java.net.InetSocketAddress) (connection.getRemoteAddress())).getPort()));
 
-            GameProfile profile;
-            try {
-                profile = VelocityLib.createProfile(buf);
-            } catch (Exception e) {
-                LogManager.getLogger().error("Profile create failed.", e);
-                handler.disconnect(Component.nullToEmpty("Unable to read player profile"));
-                return;
-            }
+                GameProfile profile;
+                try {
+                    profile = VelocityLib.createProfile(buf);
+                } catch (Exception e) {
+                    LogManager.getLogger().error("Profile create failed.", e);
+                    handler.disconnect(Component.nullToEmpty("Unable to read player profile"));
+                    return;
+                }
 
-            if (config.getHackEarlySend()) {
-                ((ServerLoginPacketListenerAccessor) handler).setAuthenticatedProfile(profile);
-                handler.handleHello(new ServerboundHelloPacket(profile.name(), profile.id()));
-            }
+                if (config.getHackEarlySend()) {
+                    ((ServerLoginPacketListenerAccessor) handler).setAuthenticatedProfile(profile);
+                    handler.handleHello(new ServerboundHelloPacket(profile.name(), profile.id()));
+                }
 
-            ((ServerLoginPacketListenerAccessor) handler).setAuthenticatedProfile(profile);
-        }));
+                ((ServerLoginPacketListenerAccessor) handler).setAuthenticatedProfile(profile);
+            }));
+        }
     }
 }