We need to ensure no invalid packs end up being loaded - otherwise, chaos ensues since the client will either show bogus resource pack size values (invalid sizes), or skip resource packs altogether (if not properly zipped).

core/src/main/java/org/geysermc/geyser/network/UpstreamPacketHandler.java

@@ -55,15 +55,13 @@ import org.geysermc.geyser.util.WebUtils;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.SeekableByteChannel;
-import java.util.ArrayDeque;
-import java.util.Deque;
-import java.util.HashMap;
-import java.util.OptionalInt;
+import java.util.*;
 
 public class UpstreamPacketHandler extends LoggingPacketHandler {
 
     private boolean networkSettingsRequested = false;
     private final Deque<String> packsToSent = new ArrayDeque<>();
+    private final List<UUID> brokenResourcePacks = new ArrayList<>();
 
     private SessionLoadResourcePacksEventImpl resourcePackLoadEvent;
 
@@ -281,9 +279,13 @@ public class UpstreamPacketHandler extends LoggingPacketHandler {
         // Check for packs that the client should normally download on its own. If the client cannot find the pack, we provide it instead.
         if (codec instanceof UrlPackCodec urlPackCodec) {
             if (!GameProtocol.isPre1_20_30(this.session)) {
-                GeyserImpl.getInstance().getLogger().warning("Received a request for a remote pack that the client should have already downloaded!" +
-                        "Is the pack at the URL " + urlPackCodec.url() + " still available?");
-                WebUtils.checkUrlAndDownloadRemotePack(urlPackCodec.url());
+                // Ensure we don't a. spam console, and b. spam download/check requests
+                if (!brokenResourcePacks.contains(packet.getPackId())) {
+                    brokenResourcePacks.add(packet.getPackId());
+                    GeyserImpl.getInstance().getLogger().warning("Received a request for a remote pack that the client should have already downloaded!" +
+                            "Is the pack at the URL " + urlPackCodec.url() + " still available?");
+                    WebUtils.checkUrlAndDownloadRemotePack(urlPackCodec.url());
+                }
             }
         }
 

core/src/main/java/org/geysermc/geyser/pack/url/GeyserUrlPackCodec.java

@@ -35,6 +35,7 @@ import org.geysermc.geyser.registry.loader.ResourcePackLoader;
 
 import java.io.IOException;
 import java.nio.channels.SeekableByteChannel;
+import java.nio.file.Path;
 
 public class GeyserUrlPackCodec extends UrlPackCodec {
     private final String url;
@@ -80,16 +81,17 @@ public class GeyserUrlPackCodec extends UrlPackCodec {
     public ResourcePack create() {
         if (this.fallback == null) {
             try {
-                this.fallback = new GeyserPathPackCodec(ResourcePackLoader.downloadPack(url).whenComplete((pack, throwable) -> {
+                final Path downloadedPack = ResourcePackLoader.downloadPack(url).whenComplete((pack, throwable) -> {
                     if (throwable != null) {
                         GeyserImpl.getInstance().getLogger().error("Failed to download pack from " + url, throwable);
                         if (GeyserImpl.getInstance().getConfig().isDebugMode()) {
                             throwable.printStackTrace();
                         }
                     }
-                }).join());
+                }).join();
+                this.fallback = new GeyserPathPackCodec(downloadedPack);
             } catch (Exception e) {
-                throw new IllegalArgumentException("Unable to download pack from " + url, e);
+                throw new IllegalArgumentException("Failed to download pack from " + url, e);
             }
         }
         return ResourcePackLoader.readPack(this);

core/src/main/java/org/geysermc/geyser/registry/loader/ResourcePackLoader.java

@@ -254,7 +254,7 @@ public class ResourcePackLoader implements RegistryLoader<Path, Map<String, Reso
                 // Check if a "manifest.json" or "pack_manifest.json" file is located directly in the zip... does not work otherwise.
                 // (something like MyZip.zip/manifest.json) will not, but will if it's a subfolder (MyPack.zip/MyPack/manifest.json)
                 if (zip.getEntry("manifest.json") != null || zip.getEntry("pack_manifest.json") != null) {
-                    GeyserImpl.getInstance().getLogger().warning("The remote resource pack from " + url + " contains a manifest.json file at the root of the zip file. " +
+                    throw new IllegalArgumentException("The remote resource pack from " + url + " contains a manifest.json file at the root of the zip file. " +
                             "This is not supported for remote packs, and will cause Bedrock clients to fall back to request the pack from the server. " +
                             "Please put the pack file in a subfolder, and provide that zip in the URL.");
                 }

core/src/main/java/org/geysermc/geyser/util/WebUtils.java

@@ -115,12 +115,12 @@ public class WebUtils {
 
                 if (size <= 0) {
                     GeyserImpl.getInstance().getLogger().error(String.format("Invalid size from remote pack URL: %s (size: %d)", url, size));
-                    //return null;
+                    return null;
                 }
 
                 if (type == null || !type.equals("application/zip")) {
                     GeyserImpl.getInstance().getLogger().error(String.format("Invalid application type from remote pack URL: %s (type: %s)", url, type));
-                    //return null;
+                    return null;
                 }
 
                 InputStream in = con.getInputStream();
@@ -129,17 +129,15 @@ public class WebUtils {
 
                 if (Files.size(fileLocation) != size) {
                     GeyserImpl.getInstance().getLogger().error("Downloaded pack has " + Files.size(fileLocation) + " bytes, expected " + size + " bytes");
-                    //Files.delete(fileLocation);
-                    //return null;
+                    Files.delete(fileLocation);
+                    return null;
                 }
 
                 return fileLocation;
             } catch (MalformedURLException e) {
-                GeyserImpl.getInstance().getLogger().error("Malformed URL: " + url);
-                return null;
+                throw new IllegalArgumentException("Malformed URL: " + url);
             } catch (IOException e) {
-                GeyserImpl.getInstance().getLogger().error("Unable to download and save file: " + url + ")");
-                return null;
+                throw new RuntimeException("Unable to download and save file: " + url + ")");
             }
         });
     }