NoFallCheck implementation

plugin.yml

@@ -30,6 +30,7 @@ permissions:
       nocheat.checks.moving.swimming: true
       nocheat.checks.moving.sneaking: true
       nocheat.checks.moving.noclip: true
+      nocheat.checks.moving.nofall: true
       nocheat.checks.moving.morepackets: true
 
   nocheat.checks.blockbreak.*:
@@ -69,6 +70,9 @@ permissions:
   nocheat.checks.moving.noclip:
     description: Allow a player to walk through walls
     default: op
+  nocheat.checks.moving.nofall:
+    description: Allow a player to cheat and not take fall damage at all
+    default: op
   nocheat.checks.moving.morepackets:
     description: Allow a player to send more move-event-packets than normal, causing him to move faster than normal
     default: op

src/cc/co/evenprime/bukkit/nocheat/DefaultConfiguration.java

@@ -77,22 +77,24 @@ public class DefaultConfiguration {
                 runflyNode.add(new IntegerOption("swimmingspeedlimit", 18));
 
                 ActionListOption walkactions = new ActionListOption("actions");
-
                 runflyNode.add(walkactions);
-
                 walkactions.add(0, "moveLogLowShort moveCancel");
                 walkactions.add(100, "moveLogMedShort moveCancel");
                 walkactions.add(400, "moveLogHighShort moveCancel");
 
+                runflyNode.add(new BooleanOption("checknofall", true, false));
+                runflyNode.add(new IntegerOption("nofallmultiplier", 100));
+                ActionListOption nofallactions = new ActionListOption("nofallactions");
+                runflyNode.add(nofallactions);
+                nofallactions.add(0, "nofallLog nofallCancel");
+
                 runflyNode.add(new BooleanOption("allowlimitedflying", false, false));
 
                 runflyNode.add(new IntegerOption("flyingspeedlimitvertical", 100));
                 runflyNode.add(new IntegerOption("flyingspeedlimithorizontal", 60));
 
                 ActionListOption flyactions = new ActionListOption("flyingactions");
-
                 runflyNode.add(flyactions);
-
                 flyactions.add(0, "moveLogLowShort moveCancel");
                 flyactions.add(100, "moveLogMedShort moveCancel");
                 flyactions.add(400, "moveLogHighShort moveCancel");
@@ -330,6 +332,7 @@ public class DefaultConfiguration {
             w(w, "log durabilityLog 0 1 med NC: [player] failed [check]: tried to use infinity durability hack.");
             w(w, "log onliquidLog 2 1 med NC: [player] failed [check]: tried to place a block on liquids.");
             w(w, "log spamLog 0 4 med NC: [player] failed [check]: Last sent message \"[text]\".");
+            w(w, "log nofallLog 0 1 med NC: [player] failed [check]: tried to avoid fall damage for ~[distance] blocks.");
             w(w, "");
             w(w, "# SPECIAL Actions: They will do something check dependant, usually cancel an event.");
             w(w, "#   - They start with the word 'special'");
@@ -344,6 +347,7 @@ public class DefaultConfiguration {
             w(w, "special blockplaceCancel 0 0");
             w(w, "special interactCancel 0 0");
             w(w, "special spamCancel 0 0");
+            w(w, "special nofallCancel 0 0");
             w(w, "");
             w(w, "# CONSOLECOMMAND Actions: They will execute a command as if it were typed into the console.");
             w(w, "#   - They start with the word 'consolecommand'");

src/cc/co/evenprime/bukkit/nocheat/Permissions.java

@@ -23,6 +23,7 @@ public class Permissions {
     public final static String  MOVE_SWIM            = _MOVE + ".swimming";
     public final static String  MOVE_FLY             = _MOVE + ".flying";
     public final static String  MOVE_NOCLIP          = _MOVE + ".noclip";
+    public final static String  MOVE_NOFALL          = _MOVE + ".nofall";
     public final static String  MOVE_MOREPACKETS     = _MOVE + ".morepackets";
 
     public final static String  BLOCKBREAK           = _CHECKS + ".blockbreak.*";

src/cc/co/evenprime/bukkit/nocheat/checks/moving/NoFallCheck.java

@@ -0,0 +1,86 @@
+package cc.co.evenprime.bukkit.nocheat.checks.moving;
+
+import java.util.HashMap;
+import java.util.Locale;
+
+import net.minecraft.server.DamageSource;
+
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.entity.CraftEntity;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Event.Type;
+import org.bukkit.event.entity.EntityDamageEvent;
+
+import cc.co.evenprime.bukkit.nocheat.NoCheat;
+import cc.co.evenprime.bukkit.nocheat.actions.ActionExecutor;
+import cc.co.evenprime.bukkit.nocheat.actions.ActionExecutorWithHistory;
+import cc.co.evenprime.bukkit.nocheat.actions.types.LogAction;
+import cc.co.evenprime.bukkit.nocheat.config.cache.ConfigurationCache;
+import cc.co.evenprime.bukkit.nocheat.data.MovingData;
+
+/**
+ * A check to see if people cheat by tricking the server to not deal them
+ * fall damage.
+ * 
+ * @author Evenprime
+ * 
+ */
+public class NoFallCheck {
+
+    private final ActionExecutor action;
+    private final NoCheat plugin;
+
+    public NoFallCheck(NoCheat plugin) {
+        this.action = new ActionExecutorWithHistory(plugin);
+        this.plugin = plugin;
+    }
+
+    /**
+     * Calculate if and how much the player "failed" this check.
+     * 
+     */
+    public void check(final Player player, final Location from, final boolean fromOnOrInGround, final Location to, final boolean toOnOrInGround, final ConfigurationCache cc, final MovingData data) {
+
+        double oldY = from.getY();
+        double newY = to.getY();
+
+        // This check is pretty much always a step behind for technical reasons.
+        if(fromOnOrInGround) {
+            // Start with zero fall distance
+            data.fallDistance = 0F;
+        }
+
+        // We want to know if the fallDistance recorded by the game is smaller
+        // than the fall distance recorded by the plugin
+        float distance = data.fallDistance - player.getFallDistance();
+        
+        if(distance > 0.01 && toOnOrInGround && data.fallDistance > 2.0F) {
+            data.nofallViolationLevel += distance;
+            // Prepare some event-specific values for logging and custom actions
+            HashMap<String, String> params = new HashMap<String, String>();
+            params.put(LogAction.DISTANCE, String.format(Locale.US, "%.2f", data.fallDistance));
+            params.put(LogAction.CHECK, "nofall");
+
+            boolean cancel = action.executeActions(player, cc.moving.nofallActions, (int) data.nofallViolationLevel, params, cc);
+
+            // If "cancelled", the fall damage gets dealt in a way that's visible to other players
+            if(cancel) {
+                // Increase the damage a bit :)
+                float totalDistance = (data.fallDistance - 2.0F)* cc.moving.nofallMultiplier + 2.0F;
+                player.setFallDistance(totalDistance);
+                ((CraftPlayer)player).getHandle().b(totalDistance, true);
+            }
+            
+            data.fallDistance = 0F;
+        }
+
+        // Reduce falldamage violation level
+        data.nofallViolationLevel *= 0.99D;
+
+        // Increase the fall distance that is recorded by the plugin
+        if(!toOnOrInGround && oldY > newY) {
+            data.fallDistance += (float) (oldY - newY);
+        }
+    }
+}

src/cc/co/evenprime/bukkit/nocheat/checks/moving/RunFlyCheck.java

@@ -23,6 +23,7 @@ public class RunFlyCheck {
     private final FlyingCheck       flyingCheck;
     private final RunningCheck      runningCheck;
     private final NoclipCheck       noclippingCheck;
+    private final NoFallCheck       noFallCheck;
     private final MorePacketsCheck  morePacketsCheck;
 
     private final MovingEventHelper helper;
@@ -31,7 +32,8 @@ public class RunFlyCheck {
         this.helper = new MovingEventHelper();
 
         this.flyingCheck = new FlyingCheck(plugin);
-        this.runningCheck = new RunningCheck(plugin);
+        this.noFallCheck = new NoFallCheck(plugin);
+        this.runningCheck = new RunningCheck(plugin, noFallCheck);
         this.noclippingCheck = new NoclipCheck(plugin);
         this.morePacketsCheck = new MorePacketsCheck(plugin);
     }

src/cc/co/evenprime/bukkit/nocheat/checks/moving/RunningCheck.java

@@ -34,8 +34,11 @@ public class RunningCheck {
     
     private final ActionExecutor action;
 
-    public RunningCheck(NoCheat plugin) {
+    private final NoFallCheck noFallCheck;
+
+    public RunningCheck(NoCheat plugin, NoFallCheck noFallCheck) {
         this.action = new ActionExecutorWithHistory(plugin);
+        this.noFallCheck = noFallCheck;
     }
 
     public Location check(final Player player, final Location from, final Location to, final MovingEventHelper helper, final ConfigurationCache cc, final MovingData data) {
@@ -106,6 +109,13 @@ public class RunningCheck {
             }
         }
         
+        /********* EXECUTE THE NOFALL CHECK ********************/
+        final boolean checkNoFall = cc.moving.nofallCheck && !player.hasPermission(Permissions.MOVE_NOFALL);
+        
+        if(checkNoFall && newToLocation == null) {
+            noFallCheck.check(player, from, fromOnGround || fromInGround, to, toOnGround || toInGround, cc, data);
+        }
+
         return newToLocation;
     }
 
@@ -176,7 +186,6 @@ public class RunningCheck {
         double distanceAboveLimit = 0.0D;
 
         final double toY = to.getY();
-        final double fromY = from.getY();
 
         double limit = data.vertFreedom + cc.moving.jumpheight;
 

src/cc/co/evenprime/bukkit/nocheat/config/cache/CCMoving.java

@@ -31,6 +31,10 @@ public class CCMoving {
     public final boolean    noclipCheck;
     public final ActionList noclipActions;
 
+    public final boolean    nofallCheck;
+    public final float      nofallMultiplier;
+    public final ActionList nofallActions;
+
     public final boolean    morePacketsCheck;
     public final ActionList morePacketsActions;
 
@@ -54,6 +58,10 @@ public class CCMoving {
         flyingSpeedLimitHorizontal = ((double) data.getInteger("moving.runfly.flyingspeedlimithorizontal")) / 100D;
         flyingActions = data.getActionList("moving.runfly.flyingactions");
 
+        nofallCheck = data.getBoolean("moving.runfly.checknofall");
+        nofallMultiplier = ((float) data.getInteger("moving.runfly.nofallmultiplier")) / 100F;
+        nofallActions = data.getActionList("moving.runfly.nofallactions");
+
         noclipCheck = data.getBoolean("moving.noclip.check");
         noclipActions = data.getActionList("moving.noclip.actions");
 

src/cc/co/evenprime/bukkit/nocheat/data/MovingData.java

@@ -22,6 +22,9 @@ public class MovingData {
     public double   horizFreedom              = 0.0D;
     public int      horizVelocityCounter      = 0;
 
+    public double   nofallViolationLevel      = 0.0D;
+    public float    fallDistance              = 0.0F;
+
     public int      noclipX;
     public int      noclipY;
     public int      noclipZ;

src/cc/co/evenprime/bukkit/nocheat/events/PlayerTeleportEventManager.java

@@ -90,6 +90,7 @@ public class PlayerTeleportEventManager extends PlayerListener implements EventM
         data.morePacketsCounter = 0;
         data.morePacketsSetbackPoint = null;
         data.jumpPhase = 0;
+        data.fallDistance = 0F;
         
         if(newLocation != null) {