Tailscale Plugin :D

README.md

@@ -9,6 +9,7 @@ server.
 * foundation-bifrost: Discord chat bridge
 * foundation-chaos: Simulate chaos inside a minecraft world
 * foundation-heimdall: Event tracking
+* foundation-tailscale: Connect the Minecraft Server to Tailscale
 
 ## Tools
 

foundation-tailscale/build.gradle.kts

@@ -0,0 +1,20 @@
+plugins {
+  id("gay.pizza.foundation.concrete-plugin")
+}
+
+repositories {
+  maven {
+    name = "GitLabLibtailscale"
+    url = uri("https://gitlab.com/api/v4/projects/44435887/packages/maven")
+  }
+}
+
+dependencies {
+  implementation(project(":common-plugin"))
+  compileOnly(project(":foundation-shared"))
+  implementation(libs.tailscale)
+}
+
+concreteItem {
+  dependency(project(":foundation-core"))
+}

foundation-tailscale/src/main/kotlin/gay/pizza/foundation/tailscale/FoundationTailscalePlugin.kt

@@ -0,0 +1,30 @@
+package gay.pizza.foundation.tailscale
+
+import com.charleskorn.kaml.Yaml
+import gay.pizza.foundation.common.BaseFoundationPlugin
+import gay.pizza.foundation.common.FoundationCoreLoader
+import gay.pizza.foundation.shared.PluginMainClass
+import gay.pizza.foundation.shared.copyDefaultConfig
+import kotlin.io.path.inputStream
+
+@PluginMainClass
+class FoundationTailscalePlugin : BaseFoundationPlugin() {
+  lateinit var config: TailscaleConfig
+  lateinit var controller: TailscaleController
+
+  override fun onEnable() {
+    val foundation = FoundationCoreLoader.get(server)
+    val configPath = copyDefaultConfig<FoundationTailscalePlugin>(
+      slF4JLogger,
+      foundation.pluginDataPath,
+      "tailscale.yaml"
+    )
+    config = Yaml.default.decodeFromStream(TailscaleConfig.serializer(), configPath.inputStream())
+    controller = TailscaleController(server, config)
+    controller.enable()
+  }
+
+  override fun onDisable() {
+    controller.disable()
+  }
+}

foundation-tailscale/src/main/kotlin/gay/pizza/foundation/tailscale/TailscaleConfig.kt

@@ -0,0 +1,13 @@
+package gay.pizza.foundation.tailscale
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class TailscaleConfig(
+  val enabled: Boolean = false,
+  val hostname: String,
+  val controlUrl: String? = null,
+  val authKey: String? = null,
+  val tailscalePath: String? = null,
+  val ephemeral: Boolean = false
+)

foundation-tailscale/src/main/kotlin/gay/pizza/foundation/tailscale/TailscaleController.kt

@@ -0,0 +1,38 @@
+package gay.pizza.foundation.tailscale
+
+import gay.pizza.tailscale.core.Tailscale
+import org.bukkit.Server
+
+class TailscaleController(val server: Server, val config: TailscaleConfig) {
+  private val tailscale = Tailscale()
+
+  var tailscaleProxyServer: TailscaleProxyServer? = null
+
+  fun enable() {
+    if (!config.enabled) {
+      return
+    }
+    tailscale.hostname = config.hostname
+
+    if (config.controlUrl != null) {
+      tailscale.controlUrl = config.controlUrl
+    }
+
+    if (config.authKey != null) {
+      tailscale.authKey = config.authKey
+    }
+
+    if (config.tailscalePath != null) {
+      tailscale.directoryPath = config.tailscalePath
+    }
+
+    tailscale.up()
+    tailscaleProxyServer = TailscaleProxyServer(server, tailscale)
+    tailscaleProxyServer?.listen()
+  }
+
+  fun disable() {
+    tailscaleProxyServer?.close()
+    tailscale.close()
+  }
+}

foundation-tailscale/src/main/kotlin/gay/pizza/foundation/tailscale/TailscaleProxyServer.kt

@@ -0,0 +1,70 @@
+package gay.pizza.foundation.tailscale
+
+import gay.pizza.tailscale.core.Tailscale
+import gay.pizza.tailscale.core.TailscaleConn
+import gay.pizza.tailscale.core.TailscaleListener
+import org.bukkit.Server
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+import java.nio.channels.ClosedChannelException
+import java.nio.channels.ReadableByteChannel
+import java.nio.channels.SocketChannel
+import java.nio.channels.WritableByteChannel
+
+class TailscaleProxyServer(val server: Server, val tailscale: Tailscale) {
+  private var minecraftServerListener: TailscaleListener? = null
+
+  fun listen() {
+    minecraftServerListener?.close()
+    minecraftServerListener = tailscale.listen("tcp", ":25565")
+    val thread = Thread {
+      minecraftServerListener?.threadedAcceptLoop { conn ->
+        handleServerConnection(conn)
+      }
+    }
+    thread.name = "Tailscale Accept Loop"
+    thread.start()
+  }
+
+  fun handleServerConnection(conn: TailscaleConn) {
+    val socketChannel = SocketChannel.open(InetSocketAddress("127.0.0.1", server.port))
+    val connChannel = conn.openReadWriteChannel()
+
+    fun closeAll() {
+      socketChannel.close()
+      connChannel.close()
+    }
+
+    fun startCopyThread(name: String, from: ReadableByteChannel, to: WritableByteChannel) {
+      val thread = Thread {
+        try {
+          while (from.isOpen && to.isOpen) {
+            val buffer = ByteBuffer.allocate(2048)
+            val size = from.read(buffer)
+            if (size < 0) {
+              break
+            } else {
+              buffer.flip()
+              val array = buffer.array()
+              to.write(buffer)
+            }
+            buffer.clear()
+          }
+        } catch (_: ClosedChannelException) {
+        } finally {
+          closeAll()
+        }
+      }
+
+      thread.name = name
+      thread.start()
+    }
+
+    startCopyThread("Tailscale to Socket Pipe", connChannel, socketChannel)
+    startCopyThread("Socket to Tailscale Pipe", socketChannel, connChannel)
+  }
+
+  fun close() {
+    minecraftServerListener?.close()
+  }
+}

foundation-tailscale/src/main/resources/plugin.yml

@@ -0,0 +1,11 @@
+name: Foundation-Tailscale
+version: '${version}'
+main: gay.pizza.foundation.tailscale.FoundationTailscalePlugin
+api-version: 1.18
+prefix: Foundation-Tailscale
+load: STARTUP
+depend:
+  - Foundation
+authors:
+  - kubeliv
+  - azenla

foundation-tailscale/src/main/resources/tailscale.yaml

@@ -0,0 +1,12 @@
+# Whether Tailscale is enabled.
+enabled: false
+# Hostname for Tailscale node.
+hostname: minecraft
+# Tailscale control URL. Null for the default.
+controlUrl: null
+# Tailscale authentication key. Null for the default.
+authKey: null
+# Tailscale path. Null for the default.
+tailscalePath: null
+# Tailscale ephemeral mode.
+ephemeral: false

install.sh

@@ -41,4 +41,3 @@ do
   # Download the plugin and store it at the mentioned path.
   curl --fail -Ls "$base_url/$artifact_path" --output "$dl_path" || (echo "Failed to download ${artifact_path}"; exit 1)
 done
-

settings.gradle.kts

@@ -33,6 +33,7 @@ include(
   ":foundation-bifrost",
   ":foundation-chaos",
   ":foundation-heimdall",
+  ":foundation-tailscale",
   ":tool-gjallarhorn",
 )
 
@@ -72,6 +73,7 @@ dependencyResolutionManagement {
       version("postgresql", "42.5.3")
       version("exposed", "0.41.1")
       version("hikaricp", "5.0.1")
+      version("libtailscale", "0.1.2-SNAPSHOT")
 
       library("clikt", "com.github.ajalt.clikt", "clikt").versionRef("clikt")
       library("xodus-core", "org.jetbrains.xodus", "xodus-openAPI").versionRef("xodus")
@@ -90,6 +92,7 @@ dependencyResolutionManagement {
       library("exposed-jdbc", "org.jetbrains.exposed", "exposed-jdbc").versionRef("exposed")
       library("exposed-java-time", "org.jetbrains.exposed", "exposed-java-time").versionRef("exposed")
       library("hikaricp", "com.zaxxer", "HikariCP").versionRef("hikaricp")
+      library("tailscale", "gay.pizza.tailscale", "tailscale").versionRef("libtailscale")
     }
   }
 }