Netty TCP and WebSocket transports

gradle/libs.versions.toml

@@ -8,6 +8,10 @@ kotlinx-bcv = "0.14.0"
 
 ktor = "2.3.8"
 
+netty = "4.1.107.Final"
+
+bouncycastle = "1.77"
+
 turbine = "1.0.0"
 
 rsocket-java = "1.1.3"
@@ -44,6 +48,11 @@ ktor-server-cio = { module = "io.ktor:ktor-server-cio", version.ref = "ktor" }
 ktor-server-netty = { module = "io.ktor:ktor-server-netty", version.ref = "ktor" }
 ktor-server-jetty = { module = "io.ktor:ktor-server-jetty", version.ref = "ktor" }
 
+netty-handler = { module = "io.netty:netty-handler", version.ref = "netty" }
+netty-codec-http = { module = "io.netty:netty-codec-http", version.ref = "netty" }
+
+bouncycastle = { module = "org.bouncycastle:bcpkix-jdk18on", version.ref = "bouncycastle" }
+
 turbine = { module = "app.cash.turbine:turbine", version.ref = "turbine" }
 
 rsocket-java-core = { module = 'io.rsocket:rsocket-core', version.ref = "rsocket-java" }

rsocket-internal-io/src/commonMain/kotlin/io/rsocket/kotlin/internal/io/Context.kt

@@ -21,3 +21,23 @@ import kotlin.coroutines.*
 
 public fun CoroutineContext.supervisorContext(): CoroutineContext = plus(SupervisorJob(get(Job)))
 public fun CoroutineContext.childContext(): CoroutineContext = plus(Job(get(Job)))
+
+public inline fun CoroutineScope.invokeOnCancellation(
+    context: CoroutineContext = EmptyCoroutineContext,
+    crossinline block: suspend () -> Unit,
+) {
+    launch(context) {
+        try {
+            awaitCancellation()
+        } catch (cause: Throwable) {
+            withContext(NonCancellable) {
+                try {
+                    block()
+                } catch (suppressed: Throwable) {
+                    cause.addSuppressed(suppressed)
+                }
+            }
+            throw cause
+        }
+    }
+}

rsocket-transports/netty-tcp/build.gradle.kts

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2015-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import rsocketbuild.*
+
+plugins {
+    id("rsocketbuild.multiplatform-library")
+}
+
+description = "rsocket-kotlin Netty TCP client/server transport implementation"
+
+kotlin {
+    jvmTarget()
+
+    sourceSets {
+        jvmMain.dependencies {
+            implementation(projects.rsocketInternalIo)
+            api(projects.rsocketCore)
+            api(libs.netty.handler)
+        }
+        jvmTest.dependencies {
+            implementation(projects.rsocketTransportTests)
+            implementation(libs.bouncycastle)
+        }
+    }
+}

rsocket-transports/netty-tcp/src/jvmMain/kotlin/io/rsocket/kotlin/transport/netty/tcp/NettyTcpChannelHandler.kt

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2015-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.rsocket.kotlin.transport.netty.tcp
+
+import io.ktor.utils.io.core.*
+import io.netty.buffer.*
+import io.netty.channel.*
+import io.netty.channel.socket.*
+import io.netty.handler.codec.*
+import io.netty.handler.ssl.*
+import io.rsocket.kotlin.internal.io.*
+import io.rsocket.kotlin.transport.*
+import kotlinx.coroutines.channels.*
+import kotlinx.coroutines.channels.Channel
+import java.net.*
+import kotlin.coroutines.*
+
+internal class NettyTcpChannelHandler(
+    private val sslContext: SslContext?,
+    private val remoteAddress: SocketAddress?,
+) : ChannelInitializer<DuplexChannel>() {
+    private val frames = channelForCloseable<ByteReadPacket>(Channel.UNLIMITED)
+
+    @RSocketTransportApi
+    fun connect(
+        context: CoroutineContext,
+        channel: DuplexChannel,
+    ): NettyTcpSession = NettyTcpSession(
+        coroutineContext = context,
+        channel = channel,
+        frames = frames
+    )
+
+    override fun initChannel(ch: DuplexChannel): Unit = with(ch.pipeline()) {
+        if (sslContext != null) {
+            val sslHandler = if (
+                remoteAddress is InetSocketAddress &&
+                ch.parent() == null // not server
+            ) {
+                sslContext.newHandler(ch.alloc(), remoteAddress.hostName, remoteAddress.port)
+            } else {
+                sslContext.newHandler(ch.alloc())
+            }
+            addLast("ssl", sslHandler)
+        }
+        addLast(
+            "rsocket-length-encoder",
+            LengthFieldPrepender(
+                /* lengthFieldLength = */ 3
+            )
+        )
+        addLast(
+            "rsocket-length-decoder",
+            LengthFieldBasedFrameDecoder(
+                /* maxFrameLength = */ Int.MAX_VALUE,
+                /* lengthFieldOffset = */ 0,
+                /* lengthFieldLength = */ 3,
+                /* lengthAdjustment = */ 0,
+                /* initialBytesToStrip = */ 3
+            )
+        )
+        addLast(
+            "rsocket-frame-receiver",
+            IncomingFramesChannelHandler(frames)
+        )
+    }
+
+    private class IncomingFramesChannelHandler(
+        private val channel: SendChannel<ByteReadPacket>,
+    ) : SimpleChannelInboundHandler<ByteBuf>() {
+        override fun channelInactive(ctx: ChannelHandlerContext) {
+            channel.close() //TODO?
+            super.channelInactive(ctx)
+        }
+
+        override fun channelRead0(ctx: ChannelHandlerContext, msg: ByteBuf) {
+            channel.trySend(buildPacket {
+                writeFully(msg.nioBuffer())
+            }).getOrThrow()
+        }
+    }
+}

rsocket-transports/netty-tcp/src/jvmMain/kotlin/io/rsocket/kotlin/transport/netty/tcp/NettyTcpClientTransport.kt

@@ -0,0 +1,157 @@
+/*
+ * Copyright 2015-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.rsocket.kotlin.transport.netty.tcp
+
+import io.netty.bootstrap.*
+import io.netty.channel.*
+import io.netty.channel.ChannelFactory
+import io.netty.channel.nio.*
+import io.netty.channel.socket.*
+import io.netty.channel.socket.nio.*
+import io.netty.handler.ssl.*
+import io.rsocket.kotlin.internal.io.*
+import io.rsocket.kotlin.transport.*
+import kotlinx.coroutines.*
+import java.net.*
+import kotlin.coroutines.*
+import kotlin.reflect.*
+
+public sealed interface NettyTcpClientTarget : RSocketClientTarget {
+    public val remoteAddress: SocketAddress
+}
+
+public sealed interface NettyTcpClientTransport : RSocketTransport<
+        InetSocketAddress,
+        NettyTcpClientTarget> {
+
+    public fun target(hostname: String, port: Int): NettyTcpClientTarget = target(InetSocketAddress(hostname, port))
+
+    public companion object Factory : RSocketTransportFactory<
+            InetSocketAddress,
+            NettyTcpClientTarget,
+            NettyTcpClientTransport,
+            NettyTcpClientTransportBuilder>(::NettyTcpClientTransportBuilderImpl)
+}
+
+public sealed interface NettyTcpClientTransportBuilder : RSocketTransportBuilder<
+        InetSocketAddress,
+        NettyTcpClientTarget,
+        NettyTcpClientTransport> {
+
+    public fun channel(cls: KClass<out DuplexChannel>)
+    public fun channelFactory(factory: ChannelFactory<out DuplexChannel>)
+    public fun eventLoopGroup(group: EventLoopGroup, manage: Boolean)
+
+    public fun bootstrap(block: Bootstrap.() -> Unit)
+    public fun ssl(block: SslContextBuilder.() -> Unit)
+}
+
+private class NettyTcpClientTransportBuilderImpl : NettyTcpClientTransportBuilder {
+    private var channelFactory: ChannelFactory<out DuplexChannel>? = null
+    private var eventLoopGroup: EventLoopGroup? = null
+    private var manageEventLoopGroup: Boolean = false
+    private var bootstrap: (Bootstrap.() -> Unit)? = null
+    private var ssl: (SslContextBuilder.() -> Unit)? = null
+
+    override fun channel(cls: KClass<out DuplexChannel>) {
+        this.channelFactory = ReflectiveChannelFactory(cls.java)
+    }
+
+    override fun channelFactory(factory: ChannelFactory<out DuplexChannel>) {
+        this.channelFactory = factory
+    }
+
+    override fun eventLoopGroup(group: EventLoopGroup, manage: Boolean) {
+        this.eventLoopGroup = group
+        this.manageEventLoopGroup = manage
+    }
+
+    override fun bootstrap(block: Bootstrap.() -> Unit) {
+        bootstrap = block
+    }
+
+    override fun ssl(block: SslContextBuilder.() -> Unit) {
+        ssl = block
+    }
+
+    @RSocketTransportApi
+    override fun buildTransport(context: CoroutineContext): NettyTcpClientTransport {
+        val group = eventLoopGroup ?: NioEventLoopGroup()
+        val factory = channelFactory ?: ReflectiveChannelFactory(NioSocketChannel::class.java)
+
+        val transportContext = context.supervisorContext() + group.asCoroutineDispatcher()
+        if (manageEventLoopGroup) CoroutineScope(transportContext).invokeOnCancellation {
+            group.shutdownGracefully().awaitFuture()
+        }
+
+        val sslContext = ssl?.let {
+            SslContextBuilder
+                .forClient()
+                .apply(it)
+                .build()
+        }
+
+        val bootstrap = Bootstrap().apply {
+            bootstrap?.invoke(this)
+            group(group)
+            channelFactory(factory)
+        }
+
+        return NettyTcpClientTransportImpl(
+            coroutineContext = transportContext,
+            sslContext = sslContext,
+            bootstrap = bootstrap
+        )
+    }
+}
+
+private class NettyTcpClientTransportImpl(
+    override val coroutineContext: CoroutineContext,
+    private val sslContext: SslContext?,
+    private val bootstrap: Bootstrap,
+) : NettyTcpClientTransport {
+    override fun target(address: InetSocketAddress): NettyTcpClientTarget = NettyTcpClientTargetImpl(
+        coroutineContext = coroutineContext.supervisorContext(),
+        remoteAddress = address,
+        sslContext = sslContext,
+        bootstrap = bootstrap
+    )
+}
+
+private class NettyTcpClientTargetImpl(
+    override val coroutineContext: CoroutineContext,
+    override val remoteAddress: SocketAddress,
+    private val sslContext: SslContext?,
+    private val bootstrap: Bootstrap,
+) : NettyTcpClientTarget {
+    @RSocketTransportApi
+    override suspend fun createSession(): RSocketTransportSession {
+        ensureActive()
+
+        val handler = NettyTcpChannelHandler(
+            sslContext = sslContext,
+            remoteAddress = remoteAddress
+        )
+        val future = bootstrap.clone().apply {
+            handler(handler)
+        }.connect(remoteAddress)
+
+        future.awaitFuture()
+
+        return handler.connect(coroutineContext.childContext(), future.channel() as DuplexChannel)
+    }
+}