improvement: Change packet handling to only handle the expected version (#18)

Author: ConnorLinfoot

README.md

@@ -7,6 +7,8 @@ At this time the API is in an early preview state to obtain feedback from the co
 
 ## Usage
 
+For using the Mod API it is highly recommended to relocate the package `net.hypixel` to prevent conflicting with other mods and different versions of the Mod API.
+
 You can use this API as a dependency via the public Hypixel maven repo.
 
 #### Hypixel Maven Repo

src/main/java/net/hypixel/modapi/HypixelModAPI.java

@@ -5,6 +5,7 @@
 import net.hypixel.modapi.handler.ClientboundPacketHandler;
 import net.hypixel.modapi.packet.ClientboundHypixelPacket;
 import net.hypixel.modapi.packet.PacketRegistry;
+import net.hypixel.modapi.packet.impl.VersionedPacket;
 import net.hypixel.modapi.packet.impl.clientbound.ClientboundLocationPacket;
 import net.hypixel.modapi.packet.impl.clientbound.ClientboundPartyInfoPacket;
 import net.hypixel.modapi.packet.impl.clientbound.ClientboundPingPacket;
@@ -71,6 +72,11 @@ public void handle(String identifier, PacketSerializer serializer) {
         }
 
         ClientboundHypixelPacket packet = registry.createClientboundPacket(identifier, serializer);
+        if (packet instanceof VersionedPacket && !((VersionedPacket) packet).isExpectedVersion()) {
+            // Ignore packets that don't match our expected version, these could be received due to other mods requesting them
+            return;
+        }
+
         for (ClientboundPacketHandler handler : handlers) {
             packet.handle(handler);
         }

src/main/java/net/hypixel/modapi/packet/impl/VersionedPacket.java

@@ -3,15 +3,26 @@
 import net.hypixel.modapi.packet.HypixelPacket;
 import net.hypixel.modapi.serializer.PacketSerializer;
 
+/**
+ * Represents a packet that is backed by a version. Versioned packets will only be handled if the incoming packet matches the version of the packet known.
+ */
 public abstract class VersionedPacket implements HypixelPacket {
-    private final int version;
+    private int version;
 
     public VersionedPacket(int version) {
         this.version = version;
     }
 
-    public VersionedPacket(PacketSerializer byteBuf) {
-        this.version = byteBuf.readVarInt();
+    public VersionedPacket(PacketSerializer serializer) {
+        read(serializer);
+    }
+
+    /**
+     * @return true if reading was successful, false if otherwise (such as due to a mismatch in version)
+     */
+    protected boolean read(PacketSerializer serializer) {
+        this.version = serializer.readVarInt();
+        return isExpectedVersion();
     }
 
     @Override
@@ -23,6 +34,12 @@ public int getVersion() {
         return version;
     }
 
+    protected abstract int getLatestVersion();
+
+    public boolean isExpectedVersion() {
+        return getVersion() == getLatestVersion();
+    }
+
     @Override
     public String toString() {
         return "VersionedPacket{" +

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundLocationPacket.java

@@ -13,17 +13,17 @@
 public class ClientboundLocationPacket extends VersionedPacket implements ClientboundHypixelPacket {
     private static final int CURRENT_VERSION = 1;
 
-    private final Environment environment;
-    private final String proxyName;
-    private final String serverName;
+    private Environment environment;
+    private String proxyName;
+    private String serverName;
     @Nullable
-    private final ServerType serverType;
+    private ServerType serverType;
     @Nullable
-    private final String lobbyName;
+    private String lobbyName;
     @Nullable
-    private final String mode;
+    private String mode;
     @Nullable
-    private final String map;
+    private String map;
 
     public ClientboundLocationPacket(Environment environment, String proxyName, String serverName, @Nullable ServerType serverType, @Nullable String lobbyName, @Nullable String mode, @Nullable String map) {
         super(CURRENT_VERSION);
@@ -38,13 +38,22 @@ public ClientboundLocationPacket(Environment environment, String proxyName, Stri
 
     public ClientboundLocationPacket(PacketSerializer serializer) {
         super(serializer);
+    }
+
+    @Override
+    protected boolean read(PacketSerializer serializer) {
+        if (!super.read(serializer)) {
+            return false;
+        }
+
         this.environment = Environment.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid environment ID"));
         this.proxyName = serializer.readString();
         this.serverName = serializer.readString();
         this.serverType = serializer.readOptional(PacketSerializer::readString).flatMap(ServerType::valueOf).orElse(null);
         this.lobbyName = serializer.readOptionally(PacketSerializer::readString);
         this.mode = serializer.readOptionally(PacketSerializer::readString);
         this.map = serializer.readOptionally(PacketSerializer::readString);
+        return true;
     }
 
     @Override
@@ -59,6 +68,11 @@ public void write(PacketSerializer serializer) {
         serializer.writeOptionally(map, PacketSerializer::writeString);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
     @Override
     public void handle(ClientboundPacketHandler handler) {
         handler.onLocationPacket(this);

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundPartyInfoPacket.java

@@ -11,9 +11,9 @@
 public class ClientboundPartyInfoPacket extends VersionedPacket implements ClientboundHypixelPacket {
     private static final int CURRENT_VERSION = 1;
 
-    private final boolean inParty;
-    private final UUID leader;
-    private final Set<UUID> members;
+    private boolean inParty;
+    private UUID leader;
+    private Set<UUID> members;
 
     public ClientboundPartyInfoPacket(boolean inParty, @Nullable UUID leader, Set<UUID> members) {
         super(CURRENT_VERSION);
@@ -24,12 +24,19 @@ public ClientboundPartyInfoPacket(boolean inParty, @Nullable UUID leader, Set<UU
 
     public ClientboundPartyInfoPacket(PacketSerializer serializer) {
         super(serializer);
+    }
+
+    @Override
+    protected boolean read(PacketSerializer serializer) {
+        if (!super.read(serializer)) {
+            return false;
+        }
 
         this.inParty = serializer.readBoolean();
         if (!inParty) {
             this.leader = null;
             this.members = Collections.emptySet();
-            return;
+            return true;
         }
 
         this.leader = serializer.readUuid();
@@ -39,6 +46,7 @@ public ClientboundPartyInfoPacket(PacketSerializer serializer) {
             members.add(serializer.readUuid());
         }
         this.members = Collections.unmodifiableSet(members);
+        return true;
     }
 
     @Override
@@ -56,6 +64,11 @@ public void write(PacketSerializer serializer) {
         }
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
     @Override
     public void handle(ClientboundPacketHandler handler) {
         handler.onPartyInfoPacket(this);

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundPingPacket.java

@@ -8,7 +8,7 @@
 public class ClientboundPingPacket extends VersionedPacket implements ClientboundHypixelPacket {
     private static final int CURRENT_VERSION = 1;
 
-    private final String response;
+    private String response;
 
     public ClientboundPingPacket(String response) {
         super(CURRENT_VERSION);
@@ -17,7 +17,16 @@ public ClientboundPingPacket(String response) {
 
     public ClientboundPingPacket(PacketSerializer serializer) {
         super(serializer);
+    }
+
+    @Override
+    protected boolean read(PacketSerializer serializer) {
+        if (!super.read(serializer)) {
+            return false;
+        }
+
         this.response = serializer.readString();
+        return true;
     }
 
     @Override
@@ -26,6 +35,11 @@ public void write(PacketSerializer serializer) {
         serializer.writeString(response);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
     @Override
     public void handle(ClientboundPacketHandler handler) {
         handler.onPingPacket(this);

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundPlayerInfoPacket.java

@@ -14,11 +14,11 @@
 public class ClientboundPlayerInfoPacket extends VersionedPacket implements ClientboundHypixelPacket {
     private static final int CURRENT_VERSION = 1;
 
-    private final PlayerRank playerRank;
-    private final PackageRank packageRank;
-    private final MonthlyPackageRank monthlyPackageRank;
+    private PlayerRank playerRank;
+    private PackageRank packageRank;
+    private MonthlyPackageRank monthlyPackageRank;
     @Nullable
-    private final String prefix;
+    private String prefix;
 
     public ClientboundPlayerInfoPacket(PlayerRank playerRank, PackageRank packageRank, MonthlyPackageRank monthlyPackageRank, @Nullable String prefix) {
         super(CURRENT_VERSION);
@@ -30,10 +30,19 @@ public ClientboundPlayerInfoPacket(PlayerRank playerRank, PackageRank packageRan
 
     public ClientboundPlayerInfoPacket(PacketSerializer serializer) {
         super(serializer);
+    }
+
+    @Override
+    protected boolean read(PacketSerializer serializer) {
+        if (!super.read(serializer)) {
+            return false;
+        }
+
         this.playerRank = PlayerRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid player rank ID"));
         this.packageRank = PackageRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid package rank ID"));
         this.monthlyPackageRank = MonthlyPackageRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid monthly package rank ID"));
         this.prefix = serializer.readOptionally(PacketSerializer::readString);
+        return true;
     }
 
     @Override
@@ -45,6 +54,11 @@ public void write(PacketSerializer serializer) {
         serializer.writeOptionally(prefix, PacketSerializer::writeString);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
     @Override
     public void handle(ClientboundPacketHandler handler) {
         handler.onPlayerInfoPacket(this);

src/main/java/net/hypixel/modapi/packet/impl/serverbound/ServerboundLocationPacket.java

@@ -14,4 +14,9 @@ public ServerboundLocationPacket(PacketSerializer serializer) {
         super(serializer);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
 }

src/main/java/net/hypixel/modapi/packet/impl/serverbound/ServerboundPartyInfoPacket.java

@@ -14,4 +14,9 @@ public ServerboundPartyInfoPacket(PacketSerializer serializer) {
         super(serializer);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
 }

src/main/java/net/hypixel/modapi/packet/impl/serverbound/ServerboundPingPacket.java

@@ -14,4 +14,9 @@ public ServerboundPingPacket(PacketSerializer serializer) {
         super(serializer);
     }
 
+    @Override
+    protected int getLatestVersion() {
+        return CURRENT_VERSION;
+    }
+
 }