Add KeepAliveFrequency check, add missing @GlobalConfig.

Limit the number of keep-alive packets to one per second.

NCPCompatProtocolLib/src/main/java/fr/neatmonster/nocheatplus/checks/net/protocollib/BaseAdapter.java

@@ -0,0 +1,51 @@
+package fr.neatmonster.nocheatplus.checks.net.protocollib;
+
+import org.bukkit.plugin.Plugin;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.ListenerOptions;
+import com.comphenix.protocol.events.ListenerPriority;
+import com.comphenix.protocol.events.PacketAdapter;
+
+import fr.neatmonster.nocheatplus.NCPAPIProvider;
+import fr.neatmonster.nocheatplus.checks.CheckType;
+import fr.neatmonster.nocheatplus.checks.net.NetConfigCache;
+import fr.neatmonster.nocheatplus.checks.net.NetDataFactory;
+import fr.neatmonster.nocheatplus.stats.Counters;
+
+/**
+ * Convenience base class for PacketAdapter creation with using config, data, counters.
+ * @author asofold
+ *
+ */
+public abstract class BaseAdapter extends PacketAdapter {
+
+    protected final Counters counters = NCPAPIProvider.getNoCheatPlusAPI().getGenericInstance(Counters.class);
+    protected final NetConfigCache configFactory = (NetConfigCache) CheckType.NET.getConfigFactory();
+    protected final NetDataFactory dataFactory = (NetDataFactory) CheckType.NET.getDataFactory();
+
+    public BaseAdapter(AdapterParameteters params) {
+        super(params);
+    }
+
+    public BaseAdapter(Plugin plugin, Iterable<? extends PacketType> types) {
+        super(plugin, types);
+    }
+
+    public BaseAdapter(Plugin plugin, ListenerPriority listenerPriority, Iterable<? extends PacketType> types, ListenerOptions... options) {
+        super(plugin, listenerPriority, types, options);
+    }
+
+    public BaseAdapter(Plugin plugin, ListenerPriority listenerPriority, Iterable<? extends PacketType> types) {
+        super(plugin, listenerPriority, types);
+    }
+
+    public BaseAdapter(Plugin plugin, ListenerPriority listenerPriority, PacketType... types) {
+        super(plugin, listenerPriority, types);
+    }
+
+    public BaseAdapter(Plugin plugin, PacketType... types) {
+        super(plugin, types);
+    }
+
+}

NCPCompatProtocolLib/src/main/java/fr/neatmonster/nocheatplus/checks/net/protocollib/FlyingFrequency.java

@@ -7,7 +7,6 @@ import org.bukkit.plugin.Plugin;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.events.ListenerPriority;
-import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.events.PacketEvent;
 
@@ -16,12 +15,8 @@ import fr.neatmonster.nocheatplus.checks.Check;
 import fr.neatmonster.nocheatplus.checks.CheckType;
 import fr.neatmonster.nocheatplus.checks.moving.MovingData;
 import fr.neatmonster.nocheatplus.checks.net.NetConfig;
-import fr.neatmonster.nocheatplus.checks.net.NetConfigCache;
 import fr.neatmonster.nocheatplus.checks.net.NetData;
-import fr.neatmonster.nocheatplus.checks.net.NetDataFactory;
 import fr.neatmonster.nocheatplus.logging.Streams;
-import fr.neatmonster.nocheatplus.stats.Counters;
-import fr.neatmonster.nocheatplus.time.monotonic.Monotonic;
 import fr.neatmonster.nocheatplus.utilities.CheckUtils;
 import fr.neatmonster.nocheatplus.utilities.TrigUtil;
 
@@ -32,7 +27,7 @@ import fr.neatmonster.nocheatplus.utilities.TrigUtil;
  * @author dev1mc
  *
  */
-public class FlyingFrequency extends PacketAdapter {
+public class FlyingFrequency extends BaseAdapter {
 
     // Setup for flying packets.
     public static final int numBooleans = 3;
@@ -44,40 +39,31 @@ public class FlyingFrequency extends PacketAdapter {
     public static final double minMoveDistSq = 1f / 256; // PlayerConnection magic.
     public static final float minLookChange = 10f;
 
-    /** Dummy check to access hasBypass for FlyingFrequency. */
+    /** Dummy check for bypass checking and actions execution. */
-    private final Check frequency = new Check(CheckType.NET_FLYINGFREQUENCY) {
+    private final Check frequency = new Check(CheckType.NET_FLYINGFREQUENCY) {};
-        // Dummy check to access hasBypass.
-    };
 
-    private final Counters counters = NCPAPIProvider.getNoCheatPlusAPI().getGenericInstance(Counters.class);
-    private final int idNullPlayer = counters.registerKey("packet.flying.nullplayer");
     private final int idHandled = counters.registerKey("packet.flying.handled");
     private final int idAsyncFlying = counters.registerKey("packet.flying.asynchronous");
 
     private boolean cancelRedundant = true;
 
-    private final NetConfigCache configs;
-    private final NetDataFactory dataFactory;
-
     public FlyingFrequency(Plugin plugin) {
         // PacketPlayInFlying[3, legacy: 10]
-        super(plugin, ListenerPriority.LOW, PacketType.Play.Client.FLYING); // TODO: How does POS and POS_LOOK relate/translate?
+        super(plugin, ListenerPriority.LOW, PacketType.Play.Client.FLYING);
-        this.configs = (NetConfigCache) CheckType.NET.getConfigFactory();
-        this.dataFactory = (NetDataFactory) CheckType.NET.getDataFactory();
     }
 
     @Override
     public void onPacketReceiving(final PacketEvent event) {
-
+        final long time =  System.currentTimeMillis();
         final Player player = event.getPlayer();
         if (player == null) {
             // TODO: Need config?
-            counters.add(idNullPlayer, 1);
+            counters.add(ProtocolLibComponent.idNullPlayer, 1);
             event.setCancelled(true);
             return;
         }
 
-        final NetConfig cc = configs.getConfig(player.getWorld());
+        final NetConfig cc = configFactory.getConfig(player.getWorld());
         if (!cc.flyingFrequencyActive) {
             return;
         }
@@ -85,7 +71,7 @@ public class FlyingFrequency extends PacketAdapter {
         counters.add(idHandled, 1);
 
         final NetData data = dataFactory.getData(player);
-        final long time =  Monotonic.millis();
+        
         // Counting all packets.
         // TODO: Consider using the NetStatic check.
         data.flyingFrequencyAll.add(time, 1f);
@@ -141,7 +127,7 @@ public class FlyingFrequency extends PacketAdapter {
                 lastTime = data.flyingFrequencyTimeNotOnGround;
                 data.flyingFrequencyTimeNotOnGround = time;
             }
-            if (time - lastTime > 1000) {
+            if (time < lastTime || time - lastTime > 1000) {
                 // Override 
                 onGroundSkip = true;
             }

NCPCompatProtocolLib/src/main/java/fr/neatmonster/nocheatplus/checks/net/protocollib/KeepAliveFrequency.java

@@ -0,0 +1,57 @@
+package fr.neatmonster.nocheatplus.checks.net.protocollib;
+
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.ListenerPriority;
+import com.comphenix.protocol.events.PacketEvent;
+
+import fr.neatmonster.nocheatplus.checks.Check;
+import fr.neatmonster.nocheatplus.checks.CheckType;
+import fr.neatmonster.nocheatplus.checks.net.NetConfig;
+import fr.neatmonster.nocheatplus.checks.net.NetData;
+
+public class KeepAliveFrequency extends BaseAdapter {
+
+    /** Dummy check for bypass checking and actions execution. */
+    private final Check check = new Check(CheckType.NET_KEEPALIVEFREQUENCY) {};
+
+    public KeepAliveFrequency(Plugin plugin) {
+        super(plugin, ListenerPriority.LOW, PacketType.Play.Client.KEEP_ALIVE);
+    }
+
+    @Override
+    public void onPacketReceiving(final PacketEvent event) {
+        final long time =  System.currentTimeMillis();
+        final Player player = event.getPlayer();
+        if (player == null) {
+            counters.add(ProtocolLibComponent.idNullPlayer, 1);
+            event.setCancelled(true);
+            return;
+        }
+        final NetConfig cc = configFactory.getConfig(player);
+        if (!cc.keepAliveFrequencyActive) {
+            return;
+        }
+        final NetData data = dataFactory.getData(player);
+        // TODO: Better modeling of actual packet sequences (flying vs. keep alive vs. request/ping).
+        // TODO: Better integration wih god-mode check / trigger reset ndt.
+        data.keepAliveFreq.add(time, 1f);
+        // Use last time accepted as a hard reference.
+        final float first = data.keepAliveFreq.bucketScore(0);
+        if (first > 1f && !check.hasBypass(player)) {
+            // Trigger a violation.
+            final double vl = Math.max(first - 1f, data.keepAliveFreq.score(1f) - data.keepAliveFreq.numberOfBuckets());
+            if (check.executeActions(player, vl, 1.0, cc.keepAliveFrequencyActions)) {
+                event.setCancelled(true);
+            }
+        }
+    }
+
+    @Override
+    public void onPacketSending(PacketEvent event) {
+        // TODO: Maybe detect if keep alive wasn't asked for + allow cancel.
+    }
+
+}

NCPCompatProtocolLib/src/main/java/fr/neatmonster/nocheatplus/checks/net/protocollib/ProtocolLibComponent.java

@@ -19,6 +19,7 @@ import fr.neatmonster.nocheatplus.components.NoCheatPlusAPI;
 import fr.neatmonster.nocheatplus.config.ConfPaths;
 import fr.neatmonster.nocheatplus.config.ConfigManager;
 import fr.neatmonster.nocheatplus.logging.StaticLog;
+import fr.neatmonster.nocheatplus.stats.Counters;
 import fr.neatmonster.nocheatplus.utilities.StringUtil;
 
 /**
@@ -28,6 +29,9 @@ import fr.neatmonster.nocheatplus.utilities.StringUtil;
  */
 public class ProtocolLibComponent implements DisableListener, INotifyReload {
 
+    // TODO: Static reference is problematic (needs a static and accessible Counters instance?). 
+    public static final int idNullPlayer = NCPAPIProvider.getNoCheatPlusAPI().getGenericInstance(Counters.class).registerKey("packet.flying.nullplayer");
+
     private final List<PacketAdapter> registeredPacketAdapters = new LinkedList<PacketAdapter>();
 
     public ProtocolLibComponent(Plugin plugin) {
@@ -40,6 +44,9 @@ public class ProtocolLibComponent implements DisableListener, INotifyReload {
         if (ConfigManager.isTrueForAnyConfig(ConfPaths.NET_FLYINGFREQUENCY_ACTIVE)) {
             register("fr.neatmonster.nocheatplus.checks.net.protocollib.FlyingFrequency", plugin);
         }
+        if (ConfigManager.isTrueForAnyConfig(ConfPaths.NET_KEEPALIVEFREQUENCY_ACTIVE)) {
+            register("fr.neatmonster.nocheatplus.checks.net.protocollib.KeepAliveFrequency", plugin);
+        }
         if (ConfigManager.isTrueForAnyConfig(ConfPaths.NET_SOUNDDISTANCE_ACTIVE)) {
             register("fr.neatmonster.nocheatplus.checks.net.protocollib.SoundDistance", plugin);
         }
@@ -91,7 +98,7 @@ public class ProtocolLibComponent implements DisableListener, INotifyReload {
     @Override
     public void onReload() {
         unregister();
-        CheckType.NET.getDataFactory().removeAllData(); // Currently needed for FlyingFRequency.
+        CheckType.NET.getDataFactory().removeAllData(); // Currently needed for FlyingFrequency.
         register(Bukkit.getPluginManager().getPlugin("NoCheatPlus")); // Store instead ?
     }
 

NCPCore/src/main/java/fr/neatmonster/nocheatplus/checks/CheckType.java

@@ -100,6 +100,7 @@ public enum CheckType {
 
     NET(new NetConfigCache(), new NetDataFactory(), Permissions.NET),
     NET_FLYINGFREQUENCY(NET, Permissions.NET_FLYINGFREQUENCY),
+    NET_KEEPALIVEFREQUENCY(NET, Permissions.NET_KEEPALIVEFREQUENCY),
     NET_SOUNDDISTANCE(NET), // Can not exempt players from this one.
 
     UNKNOWN;

NCPCore/src/main/java/fr/neatmonster/nocheatplus/checks/net/NetConfig.java

@@ -23,6 +23,9 @@ public class NetConfig extends ACheckConfig {
     public final int flyingFrequencyRedundantSeconds;
     public final ActionList flyingFrequencyRedundantActions;
 
+    public final boolean keepAliveFrequencyActive;
+    public final ActionList keepAliveFrequencyActions;
+
     public final boolean soundDistanceActive;
     /** Maximum distance for lightning effects (squared). */
     public final double soundDistanceSq;
@@ -40,6 +43,9 @@ public class NetConfig extends ACheckConfig {
         // Same permission for "silent".
         flyingFrequencyRedundantActions = config.getOptimizedActionList(ConfPaths.NET_FLYINGFREQUENCY_REDUNDANT_ACTIONS, Permissions.NET_FLYINGFREQUENCY);
 
+        keepAliveFrequencyActive = config.getBoolean(ConfPaths.NET_KEEPALIVEFREQUENCY_ACTIVE);
+        keepAliveFrequencyActions = config.getOptimizedActionList(ConfPaths.NET_KEEPALIVEFREQUENCY_ACTIONS, Permissions.NET_KEEPALIVEFREQUENCY);
+
         soundDistanceActive = config.getBoolean(ConfPaths.NET_SOUNDDISTANCE_ACTIVE);
         double dist = config.getDouble(ConfPaths.NET_SOUNDDISTANCE_MAXDISTANCE);
         soundDistanceSq = dist * dist;
@@ -53,6 +59,8 @@ public class NetConfig extends ACheckConfig {
                 return flyingFrequencyActive;
             case NET_SOUNDDISTANCE:
                 return soundDistanceActive;
+            case NET_KEEPALIVEFREQUENCY:
+                return keepAliveFrequencyActive;
             default:
                 return true;
         }

NCPCore/src/main/java/fr/neatmonster/nocheatplus/checks/net/NetData.java

@@ -4,23 +4,32 @@ import fr.neatmonster.nocheatplus.checks.access.ACheckData;
 import fr.neatmonster.nocheatplus.utilities.ActionFrequency;
 
 /**
- * Primary thread only.
+ * Data for net checks. Some data structures may not be thread-safe, but
+ * accessing each checks data individually respecting the sequence of events
+ * should work.
+ * 
  * @author asofold
  *
  */
 public class NetData extends ACheckData {
 
-    /** All flying packets, use Monotonic.millis() for time. */
+    /** All flying packets, use System.currentTimeMillis() for time. */
     public final ActionFrequency flyingFrequencyAll;
     public boolean flyingFrequencyOnGround = false;
     public long flyingFrequencyTimeOnGround = 0L;
     public long flyingFrequencyTimeNotOnGround = 0L;
     /**
      * Monitors redundant packets, when more than 20 packets per second are
-     * sent. Use Monotonic.millis() for time.
+     * sent. Use System.currentTimeMillis() for time.
      */
     public final ActionFrequency flyingFrequencyRedundantFreq;
 
+    /**
+     * Last 20 seconds keep alive packets counting. Use lastUpdate() for the
+     * time of the last event. System.currentTimeMillis() is used.
+     */
+    public ActionFrequency keepAliveFreq = new ActionFrequency(20, 1000);
+
     public NetData(final NetConfig config) {
         super(config);
         flyingFrequencyAll = new ActionFrequency(config.flyingFrequencySeconds, 1000L);

NCPCore/src/main/java/fr/neatmonster/nocheatplus/checks/net/NetDataFactory.java

@@ -7,7 +7,7 @@ import fr.neatmonster.nocheatplus.checks.access.CheckDataFactory;
 import fr.neatmonster.nocheatplus.utilities.ds.corw.LinkedHashMapCOW;
 
 /**
- * Currently primary thread only!
+ * Copy on write, right now.
  * @author asofold
  *
  */

NCPCore/src/main/java/fr/neatmonster/nocheatplus/config/ConfPaths.java

@@ -600,10 +600,6 @@ public abstract class ConfPaths {
 
     public static final String  NET                                      = CHECKS + "net.";
 
-    private static final String NET_SOUNDDISTANCE                        = NET + "sounddistance.";
-    public static final String  NET_SOUNDDISTANCE_ACTIVE                 = NET_SOUNDDISTANCE + "active";
-    public static final String  NET_SOUNDDISTANCE_MAXDISTANCE            = NET_SOUNDDISTANCE + "maxdistance";
-
     private static final String NET_FLYINGFREQUENCY                      = NET + "flyingfrequency.";
     public static final String  NET_FLYINGFREQUENCY_ACTIVE               = NET_FLYINGFREQUENCY + "active";
     @GlobalConfig
@@ -613,9 +609,17 @@ public abstract class ConfPaths {
     public static final String  NET_FLYINGFREQUENCY_ACTIONS              = NET_FLYINGFREQUENCY + "actions";
     private static final String NET_FLYINGFREQUENCY_REDUNDANT            = NET_FLYINGFREQUENCY + "reduceredundant.";
     public static final String  NET_FLYINGFREQUENCY_REDUNDANT_ACTIVE     = NET_FLYINGFREQUENCY_REDUNDANT + "active";
+    @GlobalConfig
     public static final String  NET_FLYINGFREQUENCY_REDUNDANT_SECONDS    = NET_FLYINGFREQUENCY_REDUNDANT + "seconds";
     public static final String  NET_FLYINGFREQUENCY_REDUNDANT_ACTIONS    = NET_FLYINGFREQUENCY_REDUNDANT + "actions";
 
+    private static final String NET_KEEPALIVEFREQUENCY                   = NET + "keepalivefrequency.";
+    public static final String  NET_KEEPALIVEFREQUENCY_ACTIVE            = NET_KEEPALIVEFREQUENCY + "active";
+    public static final String  NET_KEEPALIVEFREQUENCY_ACTIONS           = NET_KEEPALIVEFREQUENCY + "actions";
+
+    private static final String NET_SOUNDDISTANCE                        = NET + "sounddistance.";
+    public static final String  NET_SOUNDDISTANCE_ACTIVE                 = NET_SOUNDDISTANCE + "active";
+    public static final String  NET_SOUNDDISTANCE_MAXDISTANCE            = NET_SOUNDDISTANCE + "maxdistance";
 
     public static final String  STRINGS                                  = "strings";
 

NCPCore/src/main/java/fr/neatmonster/nocheatplus/config/DefaultConfig.java

@@ -447,6 +447,10 @@ public class DefaultConfig extends ConfigFile {
         set(ConfPaths.NET_FLYINGFREQUENCY_REDUNDANT_SECONDS, 3);
         set(ConfPaths.NET_FLYINGFREQUENCY_REDUNDANT_ACTIONS, "cancel"); // TODO: Log actions.
 
+        // KeepAliveFrequency
+        set(ConfPaths.NET_KEEPALIVEFREQUENCY_ACTIVE, true);
+        set(ConfPaths.NET_KEEPALIVEFREQUENCY_ACTIONS, "cancel vl>10 cancel log:keepalive:0:10:if vl>40 cancel log:keepalive:0:10:icf vl>100 cancel log:keepalive:0:10:icf cmd:kickalive");
+
         // SoundDistance
         set(ConfPaths.NET_SOUNDDISTANCE_ACTIVE, true);
         set(ConfPaths.NET_SOUNDDISTANCE_MAXDISTANCE, 320);
@@ -493,7 +497,9 @@ public class DefaultConfig extends ConfigFile {
         set(ConfPaths.STRINGS + ".improbable", start + "meets the improbable more than expected" + end);
         set(ConfPaths.STRINGS + ".instantbow", start + "fires bow too fast" + end);
         set(ConfPaths.STRINGS + ".instanteat", start + "eats food [food] too fast" + end);
+        set(ConfPaths.STRINGS + ".keepalive", start + "spams keep-alive packets (god/freecam?)" + end);
         set(ConfPaths.STRINGS + ".kick", "kick [player]");
+        set(ConfPaths.STRINGS + ".kickalive", "ncp kick [player] Too many keep-alive packets.");
         set(ConfPaths.STRINGS + ".kickbedleave", "ncp delay ncp kick [player] Go find a bed!");
         set(ConfPaths.STRINGS + ".kickbspeed", "ncp kick [player] You interacted too fast!");
         set(ConfPaths.STRINGS + ".kickcaptcha", "ncp kick [player] Enter the captcha!");

NCPCore/src/main/java/fr/neatmonster/nocheatplus/permissions/Permissions.java

@@ -116,6 +116,7 @@ public class Permissions {
 
     public static final String  NET                          = CHECKS + ".net";
     public static final String  NET_FLYINGFREQUENCY          = NET + ".flyingfrequency";
+    public static final String  NET_KEEPALIVEFREQUENCY       = NET + ".keepalivefrequency";
 
     public static final String  MOVING                       = CHECKS + ".moving";
     public static final String  MOVING_CREATIVEFLY           = MOVING + ".creativefly";