Add BadPackets3

src/main/java/ac/grim/grimac/checks/impl/badpackets/BadPackets3.java

@@ -0,0 +1,74 @@
+package ac.grim.grimac.checks.impl.badpackets;
+
+import ac.grim.grimac.checks.Check;
+import ac.grim.grimac.checks.CheckData;
+import ac.grim.grimac.checks.type.PacketCheck;
+import ac.grim.grimac.checks.type.PostPredictionCheck;
+import ac.grim.grimac.player.GrimPlayer;
+import ac.grim.grimac.utils.anticheat.update.PredictionComplete;
+import com.github.retrooper.packetevents.event.PacketReceiveEvent;
+import com.github.retrooper.packetevents.wrapper.play.client.WrapperPlayClientEntityAction;
+
+import static com.github.retrooper.packetevents.protocol.packettype.PacketType.Play.Client.*;
+import static com.github.retrooper.packetevents.protocol.player.ClientVersion.V_1_9;
+import static com.github.retrooper.packetevents.wrapper.play.client.WrapperPlayClientPlayerFlying.isFlying;
+
+@CheckData(name = "BadPackets3")
+public class BadPackets3 extends Check implements PacketCheck, PostPredictionCheck {
+    public BadPackets3(GrimPlayer player) {
+        super(player);
+    }
+
+    private float sprints = 0;
+    private float sneaks = 0;
+
+    @Override
+    public void onPredictionComplete(final PredictionComplete predictionComplete) {
+        // we don't need to check pre-1.9 players here (no tick skipping)
+        if (player.getClientVersion().isOlderThan(V_1_9)) return;
+
+        if (player.skippedTickInActualMovement) {
+            sprints *= 0.05f;
+            sneaks *= 0.05f;
+        }
+
+        for (; sneaks > 1; sneaks--) flagAndAlert("sneak");
+        for (; sprints > 1; sprints--) flagAndAlert("sprint");
+        sneaks = 0;
+        sprints = 0;
+    }
+
+    @Override
+    public void onPacketReceive(PacketReceiveEvent event) {
+        if (isFlying(event.getPacketType()) && player.getClientVersion().isOlderThan(V_1_9) && !player.packetStateData.lastPacketWasTeleport) {
+            sprints = 0;
+            sneaks = 0;
+            return;
+        }
+
+        if (event.getPacketType() == ENTITY_ACTION) {
+            switch (new WrapperPlayClientEntityAction(event).getAction()) {
+                case START_SNEAKING:
+                case STOP_SNEAKING:
+                    sneaks++;
+                    if (player.getClientVersion().isOlderThan(V_1_9) && sneaks > 1) {
+                        if (flagAndAlert("sneak") && shouldModifyPackets()) {
+                            player.onPacketCancel();
+                            event.setCancelled(true);
+                        }
+                    }
+                    break;
+                case START_SPRINTING:
+                case STOP_SPRINTING:
+                    sprints++;
+                    if (player.getClientVersion().isOlderThan(V_1_9) && sprints > 1) {
+                        if (flagAndAlert("sprint") && shouldModifyPackets()) {
+                            player.onPacketCancel();
+                            event.setCancelled(true);
+                        }
+                    }
+                    break;
+            }
+        }
+    }
+}

src/main/java/ac/grim/grimac/manager/CheckManager.java

@@ -124,6 +124,7 @@ public CheckManager(GrimPlayer player) {
                 .put(SuperDebug.class, new SuperDebug(player))
                 .put(DebugHandler.class, new DebugHandler(player))
                 .put(EntityControl.class, new EntityControl(player))
+                .put(BadPackets3.class, new BadPackets3(player))
                 .put(NoSlowA.class, new NoSlowA(player))
                 .put(SetbackTeleportUtil.class, new SetbackTeleportUtil(player)) // Avoid teleporting to new position, update safe pos last
                 .put(CompensatedFireworks.class, player.compensatedFireworks)