Separate legacy and modern Fabric implementations

.github/scripts/server-smoke.py

@@ -0,0 +1,163 @@
+import argparse
+import json
+import queue
+import socket
+import struct
+import subprocess
+import sys
+import threading
+import time
+import urllib.request
+from pathlib import Path
+import shutil
+
+
+MAGIC = bytes.fromhex('00ffff00fefefefefdfdfdfd12345678')
+PROTOCOLS = {'26.1': 775, '26.1.1': 775, '26.1.2': 775, '26.2': 776, '26.3': 777,
+             '26.4-snapshot-7': 1073742169}
+
+
+def varint(value):
+    value &= 0xffffffff
+    result = bytearray()
+    while value > 127:
+        result.append((value & 127) | 128)
+        value >>= 7
+    return bytes(result + bytes([value]))
+
+
+def read_varint(stream):
+    value = 0
+    for shift in range(0, 35, 7):
+        part = stream.read(1)
+        if not part:
+            raise EOFError('Incomplete VarInt')
+        value |= (part[0] & 127) << shift
+        if part[0] < 128:
+            return value
+    raise ValueError('VarInt exceeds five bytes')
+
+
+def check_tcp(port, version):
+    host = b'127.0.0.1'
+    handshake = b'\x00' + varint(PROTOCOLS[version]) + varint(len(host)) + host + struct.pack('>H', port) + b'\x01'
+    with socket.create_connection(('127.0.0.1', port), timeout=10) as connection:
+        connection.sendall(varint(len(handshake)) + handshake + b'\x01\x00')
+        stream = connection.makefile('rb')
+        length = read_varint(stream)
+        assert 0 < length < 1048576, length
+        assert read_varint(stream) == 0
+        size = read_varint(stream)
+        assert 0 < size < length
+        status = json.loads(stream.read(size))
+        assert status['version']['name'] == version.replace('-snapshot-', ' Snapshot '), status
+        assert status['version']['protocol'] == PROTOCOLS[version], status
+
+
+def check_udp(port):
+    # Open Connection Request 1 negotiates the RakNet transport before Minecraft login.
+    request = (b'\x05' + MAGIC + b'\x09').ljust(1200, b'\x00')
+    with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as connection:
+        connection.settimeout(10)
+        connection.connect(('127.0.0.1', port))
+        connection.send(request)
+        reply = connection.recv(8192)
+        assert len(reply) == 28 and reply[0] == 6, reply.hex()
+        assert reply[1:17] == MAGIC and reply[25] == 0, reply.hex()
+        assert 128 <= struct.unpack('>H', reply[26:28])[0] <= 1200
+
+
+def start_server(folder, log, events):
+    process = subprocess.Popen(['java', '-Xms256M', '-Xmx1G', '-jar', 'fabric-server-launch.jar', 'nogui'],
+                               cwd=folder, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                               stderr=subprocess.STDOUT, text=True, encoding='utf-8', errors='replace')
+
+    def collect():
+        with log.open('w', encoding='utf-8') as output:
+            for line in process.stdout:
+                output.write(line)
+                output.flush()
+                events.put(line)
+
+    reader = threading.Thread(target=collect)
+    reader.start()
+    return process, reader
+
+
+def check_server(folder, version, native):
+    port = 25871
+    (folder / 'eula.txt').write_text('eula=true\n')
+    (folder / 'server.properties').write_text(
+        'server-ip=127.0.0.1\nserver-port=25871\nonline-mode=false\n'
+        'view-distance=2\nsimulation-distance=2\nspawn-chunk-radius=0\n'
+        'level-type=minecraft:flat\nmax-players=2\n'
+        'use-native-transport=' + str(native).lower() + '\nlevel-name=world-' + str(native).lower() + '\n')
+    log = folder / ('native.log' if native else 'nio.log')
+    events = queue.Queue()
+    process, reader = start_server(folder, log, events)
+    try:
+        deadline = time.monotonic() + 180
+        while time.monotonic() < deadline:
+            if process.poll() is not None:
+                raise RuntimeError('Server exited before readiness: ' + str(process.returncode))
+            try:
+                if 'Done (' in events.get(timeout=1):
+                    break
+            except queue.Empty:
+                pass
+        else:
+            raise TimeoutError('Server startup exceeded 180 seconds')
+        for attempt in range(10):
+            try:
+                check_tcp(port, version)
+                break
+            except (EOFError, OSError):
+                if attempt == 9:
+                    raise
+                time.sleep(0.5)
+        check_udp(port)
+        dump = subprocess.check_output(['jcmd', str(process.pid), 'Thread.print'], text=True)
+        (folder / ('native-threads.log' if native else 'nio-threads.log')).write_text(dump)
+        transport = 'Epoll' if native and sys.platform.startswith('linux') else 'NIO'
+        assert 'Netty Server ' + transport + ' Raknetify' in dump, transport
+        process.stdin.write('stop\n')
+        process.stdin.flush()
+        assert process.wait(timeout=45) == 0
+        reader.join(timeout=10)
+        text = log.read_text()
+        for failure in ('Critical injection failure', 'Mixin apply failed', 'NoClassDefFoundError', 'LEAK:'):
+            assert failure not in text, failure
+        print('PASS', version, transport, 'startup, TCP status, RakNet UDP response, shutdown', flush=True)
+    finally:
+        if process.poll() is None:
+            try:
+                process.stdin.write('stop\n')
+                process.stdin.flush()
+                process.wait(timeout=45)
+            except (OSError, subprocess.TimeoutExpired):
+                process.kill()
+                process.wait(timeout=10)
+        reader.join(timeout=10)
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--jar', type=Path, required=True)
+    parser.add_argument('--work-dir', type=Path, required=True)
+    parser.add_argument('--versions', nargs='+', default=['26.1', '26.1.1', '26.1.2', '26.2', '26.3', '26.4-snapshot-7'])
+    args = parser.parse_args()
+    for version in args.versions:
+        folder = args.work_dir / version
+        (folder / 'mods').mkdir(parents=True, exist_ok=True)
+        shutil.copy2(args.jar, folder / 'mods' / args.jar.name)
+        launcher = folder / 'fabric-server-launch.jar'
+        if not launcher.exists():
+            url = f'https://meta.fabricmc.net/v2/versions/loader/{version}/0.20.1/1.1.1/server/jar'
+            with urllib.request.urlopen(url, timeout=60) as response:
+                launcher.write_bytes(response.read())
+        check_server(folder, version, True)
+        check_server(folder, version, False)
+
+
+if __name__ == '__main__':
+    main()

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
       matrix:
         # Use these Java versions
         java: [
-          21,    # Current Java LTS & minimum supported by Minecraft
+          25,    # Required by Minecraft 26.x
         ]
         # and run on both Linux and Windows
         os: [ubuntu-24.04]
@@ -42,6 +42,14 @@ jobs:
             ${{ runner.os }}-gradle-
       - name: build
         run: ./gradlew build
+      - name: Linux server transports
+        run: python3 .github/scripts/server-smoke.py --jar fabric-26/build/libs/*-all.jar --work-dir "$RUNNER_TEMP/raknetify-smoke"
+      - name: capture server smoke logs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: Linux-server-smoke-logs
+          path: ${{ runner.temp }}/raknetify-smoke/**/*.log
       - name: upload to modrinth and curseforge
         run: ./gradlew modrinth publishMainPublicationToCurseForge
         if: github.ref == 'refs/heads/master'
@@ -51,7 +59,7 @@ jobs:
           GITHUB_EVENT_RAW_PATH: ${{ github.event_path }}
         continue-on-error: true
       - name: capture build artifacts
-        if: ${{ runner.os == 'Linux' && matrix.java == '21' }} # Only upload artifacts built from latest java on one OS
+        if: ${{ runner.os == 'Linux' && matrix.java == '25' }} # Only upload artifacts built from latest java on one OS
         uses: actions/upload-artifact@v4
         with:
           name: Artifacts

.github/workflows/checkMappings.yml

@@ -7,7 +7,7 @@ jobs:
       matrix:
         # Use these Java versions
         java: [
-          21,    # Current Java LTS & minimum supported by Minecraft
+          25,    # Required by Minecraft 26.x
         ]
         # and run on both Linux and Windows
         os: [ubuntu-24.04]
@@ -49,8 +49,7 @@ jobs:
         run: ./genMappings.sh
       - name: fail if mappings changed
         run: |
-          git update-index --refresh
-          if ! git diff-index --quiet HEAD --; then
+          if ! git diff --exit-code --; then
               echo "Mappings changed, please commit them"
               git diff
               git diff --staged

Jenkinsfile

@@ -9,7 +9,7 @@ pipeline {
         }
         stage('Build') {
             tools {
-                jdk "OpenJDK 21"
+                jdk "OpenJDK 25"
             }
             steps {
                 withMaven(

build.gradle

@@ -1,11 +1,16 @@
 plugins {
-	id 'fabric-loom' version '1.13-SNAPSHOT' apply false
+	id 'fabric-loom' version '1.17.21' apply false
+	id 'net.fabricmc.fabric-loom' version '1.17.21' apply false
 	id 'com.gradleup.shadow' version '9.2.1' apply false
-	id 'dev.yumi.gradle.licenser' version '2.1.1' apply false
+	id 'dev.yumi.gradle.licenser' version '4.0.0' apply false
 	id 'com.modrinth.minotaur' version '2.+' apply false
 	id 'io.github.themrmilchmann.curseforge-publish' version '0.8.0' apply false
 }
 
+ext.remapJarTaskType = net.fabricmc.loom.task.RemapJarTask
+ext.curseforgeAlpha = io.github.themrmilchmann.gradle.publish.curseforge.ReleaseType.ALPHA
+ext.curseforgeMarkdown = io.github.themrmilchmann.gradle.publish.curseforge.ChangelogFormat.MARKDOWN
+
 subprojects {
 	apply plugin: 'java'
 	apply plugin: 'java-library'
@@ -18,8 +23,10 @@ subprojects {
     }
 
 	version = project.mod_version + "." + getVersionSuffix()
+	if (project.name == 'fabric-26') version += '.mc26'
 
 	license {
+		include '**/*.java'
 		rule(rootProject.file('HEADER.txt'))
 	}
 
@@ -62,6 +69,12 @@ subprojects {
 				versionType = "alpha" // This is the default -- can also be `beta` or `alpha`
 //				uploadFile = remapShadowJar // With Loom, this MUST be set to `remapJar` instead of `jar`!
 				gameVersions = ["1.18", "1.18.1", "1.18.2", "1.19", "1.19.1", "1.19.2", "1.19.3", "1.19.4", "1.20", "1.20.1", "1.20.2", "1.20.3", "1.20.4", "1.20.5", "1.20.6", "1.21", "1.21.1", "1.21.2", "1.21.3", "1.21.4", "1.21.5", "1.21.6", "1.21.7", "1.21.8", "1.21.9", "1.21.10", "1.21.11"]
+				def modernVersions = ['26.1', '26.1.1', '26.1.2', '26.2', '26.3']
+				if (project.name == 'fabric-26') {
+					gameVersions = modernVersions
+				} else if (project.name != 'fabric') {
+					gameVersions.addAll(modernVersions)
+				}
 //				loaders = ["fabric"]
 				changelog = com.ishland.buildscript.ParseGItHubActionChangelog.getChangelog()
 			}

common/src/main/java/com/ishland/raknetify/common/connection/MultiChannelingStreamingCompression.java

@@ -138,6 +138,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
                     compressedFrameData.release();
                     if (payload != null) payload.release();
                 }
+                return;
             } else if (compressedFrameData.getPacketId() == compressedPacketId && compressedFrameData.getReliability().isReliable && compressedFrameData.getReliability().isOrdered && !compressedFrameData.getReliability().isSequenced && inflaters[compressedFrameData.getOrderChannel()] != null) {
                 final int orderChannel = compressedFrameData.getOrderChannel();
                 final Inflater inflater = inflaters[orderChannel];

common/src/main/java/com/ishland/raknetify/common/connection/MultiChannellingEncryption.java

@@ -57,9 +57,23 @@ public MultiChannellingEncryption(Cipher decryption, Cipher encryption) {
         this.encryption = new PacketEncryptionManager(Objects.requireNonNull(encryption));
     }
 
+    // A null manager passes that direction through while the handshake enables the other direction independently.
+    private MultiChannellingEncryption(PacketEncryptionManager decryption, PacketEncryptionManager encryption) {
+        this.decryption = decryption;
+        this.encryption = encryption;
+    }
+
+    public static MultiChannellingEncryption inbound(Cipher cipher) {
+        return new MultiChannellingEncryption(new PacketEncryptionManager(Objects.requireNonNull(cipher)), null);
+    }
+
+    public static MultiChannellingEncryption outbound(Cipher cipher) {
+        return new MultiChannellingEncryption(null, new PacketEncryptionManager(Objects.requireNonNull(cipher)));
+    }
+
     @Override
     public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
-        if (msg instanceof FrameData data) {
+        if (encryption != null && msg instanceof FrameData data) {
             data.touch();
             final ByteBuf buf = data.createData().skipBytes(1);
             ByteBuf res = null;
@@ -86,7 +100,7 @@ public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        if (msg instanceof FrameData data) {
+        if (decryption != null && msg instanceof FrameData data) {
             data.touch();
             final ByteBuf buf = data.createData().skipBytes(1);
             ByteBuf res = null;

common/src/main/java/com/ishland/raknetify/common/connection/SynchronizationLayer.java

@@ -200,6 +200,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
                     FIELD_RELIABILITY_LAST_RECEIVED_SEQ_ID.set(this.reliabilityHandler, seqId);
                 } finally {
                     byteBuf.release();
+                    packet.release();
                 }
             }
             return;