Do not apply a resource pack that has already been applied (#1236)

* Do not apply a resource pack that has already been applied

* Throw IllegalStateException in case of applying a resource pack already applied from the API

* Updated some dependencies

* Added support for ServerResourcePackSendEvent resource pack modification

api/src/main/java/com/velocitypowered/api/proxy/player/ResourcePackInfo.java

@@ -54,8 +54,7 @@ public interface ResourcePackInfo extends ResourcePackRequestLike {
    *
    * @return the hash if present or null otherwise
    */
-  @Nullable
-  byte[] getHash();
+  byte @Nullable [] getHash();
 
   /**
    * Gets the {@link Origin} of this resource-pack.

gradle/libs.versions.toml

@@ -2,26 +2,26 @@
 configurate3 = "3.7.3"
 configurate4 = "4.1.2"
 flare = "2.0.1"
-log4j = "2.20.0"
+log4j = "2.22.1"
 netty = "4.1.106.Final"
 
 [plugins]
 indra-publishing = "net.kyori.indra.publishing:2.0.6"
-shadow = "com.github.johnrengelman.shadow:8.1.0"
+shadow = "com.github.johnrengelman.shadow:8.1.1"
 spotless = "com.diffplug.spotless:6.12.0"
 
 [libraries]
 adventure-bom = "net.kyori:adventure-bom:4.15.0"
-adventure-facet = "net.kyori:adventure-platform-facet:4.3.0"
-asm = "org.ow2.asm:asm:9.5"
+adventure-facet = "net.kyori:adventure-platform-facet:4.3.2"
+asm = "org.ow2.asm:asm:9.6"
 auto-service = "com.google.auto.service:auto-service:1.0.1"
 auto-service-annotations = "com.google.auto.service:auto-service-annotations:1.0.1"
 brigadier = "com.velocitypowered:velocity-brigadier:1.0.0-SNAPSHOT"
-bstats = "org.bstats:bstats-base:3.0.1"
+bstats = "org.bstats:bstats-base:3.0.2"
 caffeine = "com.github.ben-manes.caffeine:caffeine:3.1.5"
-checker-qual = "org.checkerframework:checker-qual:3.28.0"
+checker-qual = "org.checkerframework:checker-qual:3.42.0"
 checkstyle = "com.puppycrawl.tools:checkstyle:10.9.3"
-completablefutures = "com.spotify:completable-futures:0.3.5"
+completablefutures = "com.spotify:completable-futures:0.3.6"
 configurate3-hocon = { module = "org.spongepowered:configurate-hocon", version.ref = "configurate3" }
 configurate3-yaml = { module = "org.spongepowered:configurate-yaml", version.ref = "configurate3" }
 configurate3-gson = { module = "org.spongepowered:configurate-gson", version.ref = "configurate3" }
@@ -34,7 +34,7 @@ flare-core = { module = "space.vectrix.flare:flare", version.ref = "flare" }
 flare-fastutil = { module = "space.vectrix.flare:flare-fastutil", version.ref = "flare" }
 jline = "org.jline:jline-terminal-jansi:3.23.0"
 jopt = "net.sf.jopt-simple:jopt-simple:5.0.4"
-junit = "org.junit.jupiter:junit-jupiter:5.9.0"
+junit = "org.junit.jupiter:junit-jupiter:5.10.2"
 jspecify = "org.jspecify:jspecify:0.3.0"
 kyori-ansi = "net.kyori:ansi:1.0.3"
 guava = "com.google.guava:guava:25.1-jre"
@@ -46,7 +46,7 @@ log4j-core = { module = "org.apache.logging.log4j:log4j-core", version.ref = "lo
 log4j-slf4j-impl = { module = "org.apache.logging.log4j:log4j-slf4j2-impl", version.ref = "log4j" }
 log4j-iostreams = { module = "org.apache.logging.log4j:log4j-iostreams", version.ref = "log4j" }
 log4j-jul = { module = "org.apache.logging.log4j:log4j-jul", version.ref = "log4j" }
-mockito = "org.mockito:mockito-core:5.2.0"
+mockito = "org.mockito:mockito-core:5.10.0"
 netty-codec = { module = "io.netty:netty-codec", version.ref = "netty" }
 netty-codec-haproxy = { module = "io.netty:netty-codec-haproxy", version.ref = "netty" }
 netty-codec-http = { module = "io.netty:netty-codec-http", version.ref = "netty" }
@@ -54,7 +54,7 @@ netty-handler = { module = "io.netty:netty-handler", version.ref = "netty" }
 netty-transport-native-epoll = { module = "io.netty:netty-transport-native-epoll", version.ref = "netty" }
 netty-transport-native-kqueue = { module = "io.netty:netty-transport-native-kqueue", version.ref = "netty" }
 nightconfig = "com.electronwill.night-config:toml:3.6.7"
-slf4j = "org.slf4j:slf4j-api:2.0.7"
+slf4j = "org.slf4j:slf4j-api:2.0.12"
 snakeyaml = "org.yaml:snakeyaml:1.33"
 spotbugs-annotations = "com.github.spotbugs:spotbugs-annotations:4.7.3"
 terminalconsoleappender = "net.minecrell:terminalconsoleappender:1.3.0"

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BackendPlaySessionHandler.java

@@ -174,36 +174,49 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
   }
 
   @Override
-  public boolean handle(ResourcePackRequestPacket packet) {
-    ResourcePackInfo.Builder builder = new VelocityResourcePackInfo.BuilderImpl(
+  public boolean handle(final ResourcePackRequestPacket packet) {
+    final ResourcePackInfo.Builder builder = new VelocityResourcePackInfo.BuilderImpl(
         Preconditions.checkNotNull(packet.getUrl()))
         .setId(packet.getId())
         .setPrompt(packet.getPrompt() == null ? null : packet.getPrompt().getComponent())
         .setShouldForce(packet.isRequired())
         .setOrigin(ResourcePackInfo.Origin.DOWNSTREAM_SERVER);
 
-    String hash = packet.getHash();
+    final String hash = packet.getHash();
     if (hash != null && !hash.isEmpty()) {
       if (PLAUSIBLE_SHA1_HASH.matcher(hash).matches()) {
         builder.setHash(ByteBufUtil.decodeHexDump(hash));
       }
     }
 
-    ServerResourcePackSendEvent event = new ServerResourcePackSendEvent(
-        builder.build(), this.serverConn);
-
+    final ResourcePackInfo resourcePackInfo = builder.build();
+    final ServerResourcePackSendEvent event = new ServerResourcePackSendEvent(
+            resourcePackInfo, this.serverConn);
     server.getEventManager().fire(event).thenAcceptAsync(serverResourcePackSendEvent -> {
       if (playerConnection.isClosed()) {
         return;
       }
       if (serverResourcePackSendEvent.getResult().isAllowed()) {
         final ResourcePackInfo toSend = serverResourcePackSendEvent.getProvidedResourcePack();
+        boolean modifiedPack = false;
         if (toSend != serverResourcePackSendEvent.getReceivedResourcePack()) {
           ((VelocityResourcePackInfo) toSend)
               .setOriginalOrigin(ResourcePackInfo.Origin.DOWNSTREAM_SERVER);
+          modifiedPack = true;
+        }
+        if (serverConn.getPlayer().resourcePackHandler().hasPackAppliedByHash(toSend.getHash())) {
+          // Do not apply a resource pack that has already been applied
+          if (serverConn.getConnection() != null) {
+            serverConn.getConnection().write(new ResourcePackResponsePacket(
+                    packet.getId(), packet.getHash(), PlayerResourcePackStatusEvent.Status.ACCEPTED));
+          }
+          if (modifiedPack) {
+            logger.warn("A plugin has tried to modify a ResourcePack provided by the backend server "
+                    + "with a ResourcePack already applied, the applying of the resource pack will be skipped.");
+          }
+        } else {
+          serverConn.getPlayer().resourcePackHandler().queueResourcePack(toSend);
         }
-
-        serverConn.getPlayer().resourcePackHandler().queueResourcePack(toSend);
       } else if (serverConn.getConnection() != null) {
         serverConn.getConnection().write(new ResourcePackResponsePacket(
             packet.getId(),

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/ConfigSessionHandler.java

@@ -45,7 +45,6 @@ import com.velocitypowered.proxy.protocol.packet.config.TagsUpdatePacket;
 import com.velocitypowered.proxy.protocol.util.PluginMessageUtil;
 import java.io.IOException;
 import java.util.concurrent.CompletableFuture;
-import java.util.regex.Pattern;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -54,8 +53,6 @@ import org.apache.logging.log4j.Logger;
  * 1.20.2+ switching. Yes, some of this is exceptionally stupid.
  */
 public class ConfigSessionHandler implements MinecraftSessionHandler {
-
-  private static final Pattern PLAUSIBLE_SHA1_HASH = Pattern.compile("^[a-z0-9]{40}$");
   private static final Logger logger = LogManager.getLogger(ConfigSessionHandler.class);
   private final VelocityServer server;
   private final VelocityServerConnection serverConn;
@@ -118,25 +115,39 @@ public class ConfigSessionHandler implements MinecraftSessionHandler {
   }
 
   @Override
-  public boolean handle(ResourcePackRequestPacket packet) {
+  public boolean handle(final ResourcePackRequestPacket packet) {
     final MinecraftConnection playerConnection = serverConn.getPlayer().getConnection();
 
-    ServerResourcePackSendEvent event =
-        new ServerResourcePackSendEvent(packet.toServerPromptedPack(), this.serverConn);
+    final ResourcePackInfo resourcePackInfo = packet.toServerPromptedPack();
+    final ServerResourcePackSendEvent event =
+        new ServerResourcePackSendEvent(resourcePackInfo, this.serverConn);
 
     server.getEventManager().fire(event).thenAcceptAsync(serverResourcePackSendEvent -> {
       if (playerConnection.isClosed()) {
         return;
       }
       if (serverResourcePackSendEvent.getResult().isAllowed()) {
-        ResourcePackInfo toSend = serverResourcePackSendEvent.getProvidedResourcePack();
+        final ResourcePackInfo toSend = serverResourcePackSendEvent.getProvidedResourcePack();
+        boolean modifiedPack = false;
         if (toSend != serverResourcePackSendEvent.getReceivedResourcePack()) {
           ((VelocityResourcePackInfo) toSend).setOriginalOrigin(
               ResourcePackInfo.Origin.DOWNSTREAM_SERVER);
+          modifiedPack = true;
+        }
+        if (serverConn.getPlayer().resourcePackHandler().hasPackAppliedByHash(toSend.getHash())) {
+          // Do not apply a resource pack that has already been applied
+          if (serverConn.getConnection() != null) {
+            serverConn.getConnection().write(new ResourcePackResponsePacket(
+                    packet.getId(), packet.getHash(), PlayerResourcePackStatusEvent.Status.ACCEPTED));
+          }
+          if (modifiedPack) {
+            logger.warn("A plugin has tried to modify a ResourcePack provided by the backend server "
+                    + "with a ResourcePack already applied, the applying of the resource pack will be skipped.");
+          }
+        } else {
+          resourcePackToApply = null;
+          serverConn.getPlayer().resourcePackHandler().queueResourcePack(toSend);
         }
-
-        resourcePackToApply = null;
-        serverConn.getPlayer().resourcePackHandler().queueResourcePack(toSend);
       } else if (serverConn.getConnection() != null) {
         serverConn.getConnection().write(new ResourcePackResponsePacket(
                 packet.getId(), packet.getHash(), PlayerResourcePackStatusEvent.Status.DECLINED));

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -1027,6 +1027,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player,
 
   @Override
   public void sendResourcePackOffer(ResourcePackInfo packInfo) {
+    this.resourcePackHandler.checkAlreadyAppliedPack(packInfo.getHash());
     if (this.getProtocolVersion().noLessThan(ProtocolVersion.MINECRAFT_1_8)) {
       Preconditions.checkNotNull(packInfo, "packInfo");
       this.resourcePackHandler.queueResourcePack(packInfo);

proxy/src/main/java/com/velocitypowered/proxy/connection/player/resourcepack/LegacyResourcePackHandler.java

@@ -23,6 +23,7 @@ import com.velocitypowered.api.proxy.player.ResourcePackInfo;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.connection.client.ConnectedPlayer;
 import java.util.ArrayDeque;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Queue;
@@ -169,6 +170,12 @@ public sealed class LegacyResourcePackHandler extends ResourcePackHandler
     return handleResponseResult(queued, bundle);
   }
 
+  @Override
+  public boolean hasPackAppliedByHash(final byte[] hash) {
+    return this.appliedResourcePack != null
+            && Arrays.equals(this.appliedResourcePack.getHash(), hash);
+  }
+
   protected boolean shouldDisconnectForForcePack(final PlayerResourcePackStatusEvent event) {
     return event.getStatus() == PlayerResourcePackStatusEvent.Status.DECLINED
             && event.getPackInfo() != null && event.getPackInfo().getShouldForce();

proxy/src/main/java/com/velocitypowered/proxy/connection/player/resourcepack/ModernResourcePackHandler.java

@@ -23,6 +23,7 @@ import com.velocitypowered.api.event.player.PlayerResourcePackStatusEvent;
 import com.velocitypowered.api.proxy.player.ResourcePackInfo;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.connection.client.ConnectedPlayer;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedList;
 import java.util.List;
@@ -167,4 +168,17 @@ public final class ModernResourcePackHandler extends ResourcePackHandler {
 
     return handleResponseResult(queued, bundle);
   }
+
+  @Override
+  public boolean hasPackAppliedByHash(final byte[] hash) {
+    if (hash == null) {
+      return false;
+    }
+    for (final Map.Entry<UUID, ResourcePackInfo> appliedPack : appliedResourcePacks.entrySet()) {
+      if (Arrays.equals(appliedPack.getValue().getHash(), hash)) {
+        return true;
+      }
+    }
+    return false;
+  }
 }

proxy/src/main/java/com/velocitypowered/proxy/connection/player/resourcepack/ResourcePackHandler.java

@@ -92,7 +92,9 @@ public abstract sealed class ResourcePackHandler
    */
   public void queueResourcePack(final @NotNull ResourcePackRequest request) {
     for (final net.kyori.adventure.resource.ResourcePackInfo pack : request.packs()) {
-      queueResourcePack(VelocityResourcePackInfo.fromAdventureRequest(request, pack));
+      final ResourcePackInfo resourcePackInfo = VelocityResourcePackInfo.fromAdventureRequest(request, pack);
+      this.checkAlreadyAppliedPack(resourcePackInfo.getHash());
+      queueResourcePack(resourcePackInfo);
     }
   }
 
@@ -156,4 +158,18 @@ public abstract sealed class ResourcePackHandler
     }
     return handled;
   }
+
+  /**
+   * Check if a pack has already been applied.
+   *
+   * @param hash the resource pack hash
+   */
+  public abstract boolean hasPackAppliedByHash(final byte[] hash);
+
+  @SuppressWarnings("checkstyle:MissingJavadocMethod")
+  public void checkAlreadyAppliedPack(final byte[] hash) {
+    if (this.hasPackAppliedByHash(hash)) {
+      throw new IllegalStateException("Cannot apply a resource pack already applied");
+    }
+  }
 }

settings.gradle.kts

@@ -17,7 +17,7 @@ pluginManagement {
 }
 
 plugins {
-    id("org.gradle.toolchains.foojay-resolver-convention") version "0.4.0"
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.8.0"
 }
 
 rootProject.name = "velocity"