Add packet level checks for Geyser

If AuthType == ONLINE, players will be treated as if they were Java
players
If AuthType == OFFLINE, name conflicts will be checked the same way it's
done with Floodgate
Updated config.yml to infrom about the changes.

Author: Smart123s

core/src/main/java/com/github/games647/fastlogin/core/hooks/bedrock/GeyserService.java

@@ -31,26 +31,34 @@
 import com.github.games647.fastlogin.core.shared.LoginSource;
 
 import org.geysermc.connector.GeyserConnector;
+import org.geysermc.connector.common.AuthType;
 import org.geysermc.connector.network.session.GeyserSession;
 
 public class GeyserService extends BedrockService<GeyserSession> {
 
     private final GeyserConnector geyser;
     private final FastLoginCore<?, ?, ?> core;
+    private final AuthType authType;
 
     public GeyserService(GeyserConnector geyser, FastLoginCore<?, ?, ?> core) {
         super(core);
         this.geyser = geyser;
         this.core = core;
+        this.authType = geyser.getConfig().getRemote().getAuthType();
     }
 
     @Override
     public boolean performChecks(String username, LoginSource source) {
-        //TODO: Replace stub with Geyser specific code    
-        if ("false".equals(allowConflict)) {
-                super.checkNameConflict(username, source);
-        } else {
+        // AuthType.FLOODGATE will be handled by FloodgateService
+        if (authType == AuthType.ONLINE) {
+            // authenticate everyone, as if they were Java players, since they have signed
+            // in through Mojang
+            return false;
+        }
+        if ("true".equals(allowConflict)) {
             core.getPlugin().getLog().info("Skipping name conflict checking for player {}", username);
+        } else {
+            super.checkNameConflict(username, source);    
         }
         return true;
     }

core/src/main/resources/config.yml

@@ -205,8 +205,8 @@ autoLogin: true
 # Enabling this might lead to people gaining unauthorized access to other's accounts!
 autoLoginFloodgate: false
 
-# This enables Floodgate players to join the server, even if autoRegister is true and there's an existing
-# Java **PREMIUM** account with the same name
+# This enables Floodgate or Offline Geyser players to join the server, even if they are using the name of an
+# existing Java **PREMIUM** account (so someone has bought Minecraft with that username)
 #
 # Java and Bedrock players will get different UUIDs, so their inventories, location, etc. will be different.
 # However, some plugins (such as AuthMe) rely on names instead of UUIDs to identify a player which might cause issues.
@@ -219,12 +219,13 @@ autoLoginFloodgate: false
 # A solution to this is to replace ProtocolLib with ProtocolSupport
 #
 # Possible values:
-#   false: Check for Premium Java name conflicts as described in 'autoRegister'
-#     Note: Linked players have the same name as their Java profile, so the Bedrock player will always conflict
+#   false: Kick Bedrock players, if they are using an existing Premium Java account's name
+#     Note: Linked Floodgate players have the same name as their Java profile, so the Bedrock player will always conflict
 #     their own Java account's name. Therefore, setting this to false will prevent any linked player from joining.
-#   true:  Bypass 'autoRegister's name conflict checking 
-#   linked: Bedrock accounts linked to a Java account will be allowed to join with conflicting names
-# !!!!!!!! WARNING: FLOODGATE SUPPORT IS AN EXPERIMENTAL FEATURE !!!!!!!!
+#   true: Bypass name conflict checking.
+#   linked: Floodgate accounts linked to a Java account will be allowed to join with conflicting names
+#     For Offline Geyser players, 'linked' works as 'false'
+# !!!!!!!! WARNING: FLOODGATE/GEYSER SUPPORT IS AN EXPERIMENTAL FEATURE !!!!!!!!
 # Enabling this might lead to people gaining unauthorized access to other's accounts!
 allowFloodgateNameConflict: false