Refactor KMP networking backends

docs/lyng.io.net.md

@@ -1,6 +1,6 @@
 ### lyng.io.net — TCP and UDP sockets for Lyng scripts
 
-This module provides minimal raw transport networking for Lyng scripts. It is implemented in `lyngio` and backed by Ktor sockets on the JVM and by Node networking APIs on JS/Node runtimes.
+This module provides minimal raw transport networking for Lyng scripts. It is implemented in `lyngio` and backed by Ktor sockets on the JVM and Linux Native, and by Node networking APIs on JS/Node runtimes.
 
 > **Note:** `lyngio` is a separate library module. It must be explicitly added as a dependency to your host application and initialized in your Lyng scopes.
 
@@ -164,4 +164,6 @@ The module uses `NetAccessPolicy` to authorize network operations before they ar
 - **Android:** supported via the Ktor CIO and Ktor sockets backends
 - **JS/Node:** supported for `resolve`, TCP client/server, and UDP
 - **JS/browser:** unsupported; capability checks report unavailable
-- **Other targets:** currently report unsupported; use capability checks before relying on raw sockets
+- **Linux Native:** supported via Ktor sockets
+- **Apple Native:** enabled via the shared native Ktor sockets backend; compile-verified, runtime not yet host-verified
+- **Other native targets:** currently report unsupported; use capability checks before relying on raw sockets

lyngio/build.gradle.kts

@@ -86,6 +86,9 @@ kotlin {
         }
         val nativeMain by creating {
             dependsOn(commonMain)
+            dependencies {
+                implementation(libs.ktor.network)
+            }
         }
         val darwinMain by creating {
             dependsOn(nativeMain)
@@ -117,6 +120,9 @@ kotlin {
                 implementation(libs.kotlinx.coroutines.test)
             }
         }
+        val linuxTest by creating {
+            dependsOn(commonTest)
+        }
         val iosX64Main by getting { dependsOn(iosMain) }
         val iosArm64Main by getting { dependsOn(iosMain) }
         val iosSimulatorArm64Main by getting { dependsOn(iosMain) }
@@ -124,6 +130,8 @@ kotlin {
         val mingwX64Main by getting { dependsOn(mingwMain) }
         val linuxX64Main by getting { dependsOn(linuxMain) }
         val linuxArm64Main by getting { dependsOn(linuxMain) }
+        val linuxX64Test by getting { dependsOn(linuxTest) }
+        val linuxArm64Test by getting { dependsOn(linuxTest) }
 
         // JS: use runtime detection in jsMain to select Node vs Browser implementation
         val jsMain by getting {

lyngio/src/androidMain/kotlin/net/sergeych/lyngio/http/PlatformAndroid.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.cio.CIO
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = AndroidKtorLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(CIO)
-
-private object AndroidKtorLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(CIO) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/androidMain/kotlin/net/sergeych/lyngio/ws/PlatformAndroid.kt

@@ -1,92 +1,5 @@
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.cio.CIO
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = AndroidKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(CIO)
-
-private object AndroidKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(CIO) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return AndroidLyngWsSession(url, session)
-    }
-}
-
-private class AndroidLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    @Volatile
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        session.close(CloseReason(code.toShort(), reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/commonMain/kotlin/net/sergeych/lyngio/http/KtorHttpEngine.kt

@@ -0,0 +1,61 @@
+package net.sergeych.lyngio.http
+
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.engine.HttpClientEngineConfig
+import io.ktor.client.engine.HttpClientEngineFactory
+import io.ktor.client.plugins.timeout
+import io.ktor.client.request.HttpRequestBuilder
+import io.ktor.client.request.request
+import io.ktor.client.request.setBody
+import io.ktor.http.HttpMethod
+import io.ktor.http.headers
+import io.ktor.http.takeFrom
+
+internal fun createKtorHttpEngine(
+    engineFactory: HttpClientEngineFactory<HttpClientEngineConfig>,
+): LyngHttpEngine = KtorLyngHttpEngine(engineFactory)
+
+private class KtorLyngHttpEngine(
+    engineFactory: HttpClientEngineFactory<HttpClientEngineConfig>,
+) : LyngHttpEngine {
+    private val clientResult = runCatching {
+        HttpClient(engineFactory) {
+            expectSuccess = false
+        }
+    }
+
+    override val isSupported: Boolean
+        get() = clientResult.isSuccess
+
+    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
+        val httpClient = clientResult.getOrElse {
+            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
+        }
+
+        val response = httpClient.request {
+            applyRequest(request)
+        }
+        return LyngHttpResponse(
+            status = response.status.value,
+            statusText = response.status.description,
+            headers = response.headers.entries().associate { it.key to it.value.toList() },
+            bodyBytes = response.body<ByteArray>(),
+        )
+    }
+
+    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
+        method = HttpMethod.parse(request.method.uppercase())
+        url.takeFrom(request.url)
+        headers {
+            request.headers.forEach { (name, value) -> append(name, value) }
+        }
+        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
+        when {
+            request.bodyBytes != null && request.bodyText != null ->
+                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
+            request.bodyBytes != null -> setBody(request.bodyBytes)
+            request.bodyText != null -> setBody(request.bodyText)
+        }
+    }
+}

lyngio/src/commonMain/kotlin/net/sergeych/lyngio/ws/KtorWsEngine.kt

@@ -0,0 +1,94 @@
+package net.sergeych.lyngio.ws
+
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.HttpClientEngineConfig
+import io.ktor.client.engine.HttpClientEngineFactory
+import io.ktor.client.plugins.websocket.WebSockets
+import io.ktor.client.plugins.websocket.webSocketSession
+import io.ktor.client.request.header
+import io.ktor.client.request.url
+import io.ktor.websocket.CloseReason
+import io.ktor.websocket.DefaultWebSocketSession
+import io.ktor.websocket.Frame
+import io.ktor.websocket.close
+import io.ktor.websocket.readText
+import io.ktor.websocket.send
+import kotlinx.coroutines.channels.ClosedReceiveChannelException
+
+internal fun createKtorWsEngine(
+    engineFactory: HttpClientEngineFactory<HttpClientEngineConfig>,
+): LyngWsEngine = KtorLyngWsEngine(engineFactory)
+
+private class KtorLyngWsEngine(
+    engineFactory: HttpClientEngineFactory<HttpClientEngineConfig>,
+) : LyngWsEngine {
+    private val clientResult = runCatching {
+        HttpClient(engineFactory) {
+            install(WebSockets)
+        }
+    }
+
+    override val isSupported: Boolean
+        get() = clientResult.isSuccess
+
+    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
+        val client = clientResult.getOrElse {
+            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
+        }
+        val session = client.webSocketSession {
+            url(url)
+            headers.forEach { (name, value) -> header(name, value) }
+        }
+        return KtorLyngWsSession(url, session)
+    }
+}
+
+private class KtorLyngWsSession(
+    private val targetUrl: String,
+    private val session: DefaultWebSocketSession,
+) : LyngWsSession {
+    private var closed = false
+
+    override fun isOpen(): Boolean = !closed
+
+    override fun url(): String = targetUrl
+
+    override suspend fun sendText(text: String) {
+        ensureOpen()
+        session.send(text)
+    }
+
+    override suspend fun sendBytes(data: ByteArray) {
+        ensureOpen()
+        session.send(data)
+    }
+
+    override suspend fun receive(): LyngWsMessage? {
+        if (closed) return null
+        val frame = try {
+            session.incoming.receive()
+        } catch (_: ClosedReceiveChannelException) {
+            closed = true
+            return null
+        }
+        return when (frame) {
+            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
+            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
+            is Frame.Close -> {
+                closed = true
+                null
+            }
+            else -> receive()
+        }
+    }
+
+    override suspend fun close(code: Int, reason: String) {
+        if (closed) return
+        closed = true
+        session.close(CloseReason(code.toShort(), reason))
+    }
+
+    private fun ensureOpen() {
+        if (closed) throw IllegalStateException("websocket session is closed")
+    }
+}

lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/http/PlatformDarwin.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.darwin.Darwin
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = DarwinLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(Darwin)
-
-private object DarwinLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Darwin) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/net/PlatformDarwin.kt

@@ -0,0 +1,8 @@
+package net.sergeych.lyngio.net
+
+actual fun getSystemNetEngine(): LyngNetEngine = createNativeKtorNetEngine(
+    isSupported = true,
+    isTcpAvailable = true,
+    isTcpServerAvailable = true,
+    isUdpAvailable = true,
+)

lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/ws/PlatformDarwin.kt

@@ -1,91 +1,5 @@
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.darwin.Darwin
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = DarwinKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(Darwin)
-
-private object DarwinKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Darwin) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return DarwinLyngWsSession(url, session)
-    }
-}
-
-private class DarwinLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        session.close(CloseReason(code.toShort(), reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/jsMain/kotlin/net/sergeych/lyngio/http/PlatformJs.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.js.Js
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = JsKtorLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(Js)
-
-private object JsKtorLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Js) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/jsMain/kotlin/net/sergeych/lyngio/ws/PlatformJs.kt

@@ -1,91 +1,5 @@
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.js.Js
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = JsKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(Js)
-
-private object JsKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Js) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return JsLyngWsSession(url, session)
-    }
-}
-
-private class JsLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        session.close(CloseReason(code.toShort(), reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/jvmMain/kotlin/net/sergeych/lyngio/http/PlatformJvm.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.cio.CIO
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = JvmKtorLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(CIO)
-
-private object JvmKtorLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(CIO) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/jvmMain/kotlin/net/sergeych/lyngio/ws/PlatformJvm.kt

@@ -17,94 +17,6 @@
 
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.cio.CIO
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = JvmKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(CIO)
-
-private object JvmKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(CIO) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return JvmLyngWsSession(url, session)
-    }
-}
-
-private class JvmLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    @Volatile
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        val safeCode = code.toShort()
-        session.close(CloseReason(safeCode, reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/http/PlatformLinux.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.curl.Curl
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = LinuxLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(Curl)
-
-private object LinuxLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Curl) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/net/PlatformLinux.kt

@@ -0,0 +1,8 @@
+package net.sergeych.lyngio.net
+
+actual fun getSystemNetEngine(): LyngNetEngine = createNativeKtorNetEngine(
+    isSupported = true,
+    isTcpAvailable = true,
+    isTcpServerAvailable = true,
+    isUdpAvailable = true,
+)

lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/ws/PlatformLinux.kt

@@ -1,91 +1,5 @@
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.curl.Curl
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = LinuxKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(Curl)
-
-private object LinuxKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(Curl) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return LinuxLyngWsSession(url, session)
-    }
-}
-
-private class LinuxLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        session.close(CloseReason(code.toShort(), reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/linuxTest/kotlin/net/sergeych/lyngio/net/NetLinuxNativeTest.kt

@@ -0,0 +1,90 @@
+package net.sergeych.lyngio.net
+
+import kotlinx.coroutines.async
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeout
+import net.sergeych.lyng.Compiler
+import net.sergeych.lyng.Script
+import net.sergeych.lyng.io.net.createNetModule
+import net.sergeych.lyngio.net.security.PermitAllNetAccessPolicy
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class NetLinuxNativeTest {
+
+    @Test
+    fun testLinuxNativeCapabilitiesAndResolve() = runBlocking {
+        val engine = getSystemNetEngine()
+
+        assertTrue(engine.isSupported)
+        assertTrue(engine.isTcpAvailable)
+        assertTrue(engine.isTcpServerAvailable)
+        assertTrue(engine.isUdpAvailable)
+
+        val resolved = engine.resolve("127.0.0.1", 4040)
+        assertEquals(1, resolved.size)
+        assertEquals("127.0.0.1", resolved.single().host)
+        assertEquals(4040, resolved.single().port)
+        assertEquals(LyngIpVersion.IPV4, resolved.single().ipVersion)
+        assertTrue(resolved.single().resolved)
+    }
+
+    @Test
+    fun testLinuxNativeLyngModuleCapabilities() = runBlocking {
+        val scope = Script.newScope()
+        createNetModule(PermitAllNetAccessPolicy, scope)
+
+        val code = """
+            import lyng.io.net
+
+            val a: SocketAddress = Net.resolve("127.0.0.1", 4040)[0]
+            [Net.isSupported(), Net.isTcpAvailable(), Net.isTcpServerAvailable(), Net.isUdpAvailable(), a.toString(), a.resolved]
+        """.trimIndent()
+
+        val result = Compiler.compile(code).execute(scope).inspect(scope)
+        assertTrue(result.contains("true,true,true,true"), result)
+        assertTrue(result.contains("127.0.0.1:4040"), result)
+    }
+
+    @Test
+    fun testLinuxNativeTcpAndUdpLoopback() = runBlocking {
+        val engine = getSystemNetEngine()
+
+        withTimeout(5_000) {
+            val server = engine.tcpListen(host = "127.0.0.1", port = 0, backlog = 16, reuseAddress = true)
+            val accepted = async {
+                val client = server.accept()
+                val text = client.read(4)?.decodeToString()
+                client.writeUtf8("echo:$text")
+                client.flush()
+                client.close()
+                server.close()
+                text
+            }
+
+            val socket = engine.tcpConnect("127.0.0.1", server.localAddress().port, timeoutMillis = 2_000, noDelay = true)
+            socket.writeUtf8("ping")
+            socket.flush()
+            val reply = socket.read(32)?.decodeToString()
+            socket.close()
+
+            assertEquals("ping", accepted.await())
+            assertEquals("echo:ping", reply)
+        }
+
+        withTimeout(5_000) {
+            val receiver = engine.udpBind(host = "127.0.0.1", port = 0, reuseAddress = true)
+            val sender = engine.udpBind(host = "127.0.0.1", port = 0, reuseAddress = true)
+
+            sender.send("ping".encodeToByteArray(), "127.0.0.1", receiver.localAddress().port)
+            val datagram = receiver.receive(32)
+
+            sender.close()
+            receiver.close()
+
+            assertEquals("ping", datagram?.data?.decodeToString())
+            assertTrue((datagram?.address?.port ?: 0) > 0)
+        }
+    }
+}

lyngio/src/mingwMain/kotlin/net/sergeych/lyngio/http/PlatformMingw.kt

@@ -1,58 +1,5 @@
 package net.sergeych.lyngio.http
 
-import io.ktor.client.HttpClient
-import io.ktor.client.call.body
 import io.ktor.client.engine.winhttp.WinHttp
-import io.ktor.client.plugins.timeout
-import io.ktor.client.request.HttpRequestBuilder
-import io.ktor.client.request.request
-import io.ktor.client.request.setBody
-import io.ktor.http.HttpMethod
-import io.ktor.http.headers
-import io.ktor.http.takeFrom
 
-actual fun getSystemHttpEngine(): LyngHttpEngine = MingwLyngHttpEngine
+actual fun getSystemHttpEngine(): LyngHttpEngine = createKtorHttpEngine(WinHttp)
-
-private object MingwLyngHttpEngine : LyngHttpEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(WinHttp) {
-                expectSuccess = false
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun request(request: LyngHttpRequest): LyngHttpResponse {
-        val httpClient = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "HTTP client is not supported")
-        }
-
-        val response = httpClient.request {
-            applyRequest(request)
-        }
-        return LyngHttpResponse(
-            status = response.status.value,
-            statusText = response.status.description,
-            headers = response.headers.entries().associate { it.key to it.value.toList() },
-            bodyBytes = response.body<ByteArray>(),
-        )
-    }
-
-    private fun HttpRequestBuilder.applyRequest(request: LyngHttpRequest) {
-        method = HttpMethod.parse(request.method.uppercase())
-        url.takeFrom(request.url)
-        headers {
-            request.headers.forEach { (name, value) -> append(name, value) }
-        }
-        request.timeoutMillis?.let { timeout { requestTimeoutMillis = it } }
-        when {
-            request.bodyBytes != null && request.bodyText != null ->
-                throw IllegalArgumentException("Only one of bodyText or bodyBytes may be set")
-            request.bodyBytes != null -> setBody(request.bodyBytes)
-            request.bodyText != null -> setBody(request.bodyText)
-        }
-    }
-}

lyngio/src/mingwMain/kotlin/net/sergeych/lyngio/ws/PlatformMingw.kt

@@ -1,91 +1,5 @@
 package net.sergeych.lyngio.ws
 
-import io.ktor.client.HttpClient
 import io.ktor.client.engine.winhttp.WinHttp
-import io.ktor.client.plugins.websocket.WebSockets
-import io.ktor.client.plugins.websocket.webSocketSession
-import io.ktor.client.request.header
-import io.ktor.client.request.url
-import io.ktor.websocket.CloseReason
-import io.ktor.websocket.DefaultWebSocketSession
-import io.ktor.websocket.Frame
-import io.ktor.websocket.close
-import io.ktor.websocket.readText
-import io.ktor.websocket.send
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
 
-actual fun getSystemWsEngine(): LyngWsEngine = MingwKtorWsEngine
+actual fun getSystemWsEngine(): LyngWsEngine = createKtorWsEngine(WinHttp)
-
-private object MingwKtorWsEngine : LyngWsEngine {
-    private val clientResult by lazy {
-        runCatching {
-            HttpClient(WinHttp) {
-                install(WebSockets)
-            }
-        }
-    }
-
-    override val isSupported: Boolean
-        get() = clientResult.isSuccess
-
-    override suspend fun connect(url: String, headers: Map<String, String>): LyngWsSession {
-        val client = clientResult.getOrElse {
-            throw UnsupportedOperationException(it.message ?: "WebSocket client is not supported")
-        }
-        val session = client.webSocketSession {
-            url(url)
-            headers.forEach { (name, value) -> header(name, value) }
-        }
-        return MingwLyngWsSession(url, session)
-    }
-}
-
-private class MingwLyngWsSession(
-    private val targetUrl: String,
-    private val session: DefaultWebSocketSession,
-) : LyngWsSession {
-    private var closed = false
-
-    override fun isOpen(): Boolean = !closed
-
-    override fun url(): String = targetUrl
-
-    override suspend fun sendText(text: String) {
-        ensureOpen()
-        session.send(text)
-    }
-
-    override suspend fun sendBytes(data: ByteArray) {
-        ensureOpen()
-        session.send(data)
-    }
-
-    override suspend fun receive(): LyngWsMessage? {
-        if (closed) return null
-        val frame = try {
-            session.incoming.receive()
-        } catch (_: ClosedReceiveChannelException) {
-            closed = true
-            return null
-        }
-        return when (frame) {
-            is Frame.Text -> LyngWsMessage(isText = true, text = frame.readText())
-            is Frame.Binary -> LyngWsMessage(isText = false, data = frame.data.copyOf())
-            is Frame.Close -> {
-                closed = true
-                null
-            }
-            else -> receive()
-        }
-    }
-
-    override suspend fun close(code: Int, reason: String) {
-        if (closed) return
-        closed = true
-        session.close(CloseReason(code.toShort(), reason))
-    }
-
-    private fun ensureOpen() {
-        if (closed) throw IllegalStateException("websocket session is closed")
-    }
-}

lyngio/src/nativeMain/kotlin/net/sergeych/lyngio/net/NativeKtorNetEngine.kt

@@ -0,0 +1,216 @@
+package net.sergeych.lyngio.net
+
+import io.ktor.network.selector.SelectorManager
+import io.ktor.network.sockets.BoundDatagramSocket
+import io.ktor.network.sockets.Datagram
+import io.ktor.network.sockets.InetSocketAddress
+import io.ktor.network.sockets.ServerSocket
+import io.ktor.network.sockets.Socket
+import io.ktor.network.sockets.SocketAddress
+import io.ktor.network.sockets.aSocket
+import io.ktor.network.sockets.isClosed
+import io.ktor.network.sockets.openReadChannel
+import io.ktor.network.sockets.openWriteChannel
+import io.ktor.utils.io.ByteReadChannel
+import io.ktor.utils.io.ByteWriteChannel
+import io.ktor.utils.io.readAvailable
+import io.ktor.utils.io.readUTF8Line
+import io.ktor.utils.io.writeFully
+import io.ktor.utils.io.writeStringUtf8
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withTimeout
+import kotlinx.io.Buffer
+import kotlinx.io.readByteArray
+
+internal fun createNativeKtorNetEngine(
+    isSupported: Boolean,
+    isTcpAvailable: Boolean,
+    isTcpServerAvailable: Boolean,
+    isUdpAvailable: Boolean,
+): LyngNetEngine = NativeKtorNetEngine(
+    isSupported = isSupported,
+    isTcpAvailable = isTcpAvailable,
+    isTcpServerAvailable = isTcpServerAvailable,
+    isUdpAvailable = isUdpAvailable,
+)
+
+private class NativeKtorNetEngine(
+    override val isSupported: Boolean,
+    override val isTcpAvailable: Boolean,
+    override val isTcpServerAvailable: Boolean,
+    override val isUdpAvailable: Boolean,
+) : LyngNetEngine {
+    private val selectorManager: SelectorManager by lazy { SelectorManager(Dispatchers.Default) }
+
+    override suspend fun resolve(host: String, port: Int): List<LyngSocketAddress> {
+        val rawAddress = InetSocketAddress(host, port).resolveAddress()
+            ?: throw IllegalStateException("Failed to resolve address for $host")
+        return listOf(
+            LyngSocketAddress(
+                host = rawAddress.toIpHostString(),
+                port = port,
+                ipVersion = rawAddress.toLyngIpVersion(),
+                resolved = true,
+            )
+        )
+    }
+
+    override suspend fun tcpConnect(
+        host: String,
+        port: Int,
+        timeoutMillis: Long?,
+        noDelay: Boolean,
+    ): LyngTcpSocket {
+        val connectBlock: suspend () -> Socket = {
+            aSocket(selectorManager).tcp().connect(host, port) {
+                this.noDelay = noDelay
+            }
+        }
+        val socket = if (timeoutMillis != null) withTimeout(timeoutMillis) { connectBlock() } else connectBlock()
+        return NativeLyngTcpSocket(socket)
+    }
+
+    override suspend fun tcpListen(
+        host: String?,
+        port: Int,
+        backlog: Int,
+        reuseAddress: Boolean,
+    ): LyngTcpServer {
+        val bindHost = host ?: "0.0.0.0"
+        val server = aSocket(selectorManager).tcp().bind(bindHost, port) {
+            backlogSize = backlog
+            this.reuseAddress = reuseAddress
+        }
+        return NativeLyngTcpServer(server)
+    }
+
+    override suspend fun udpBind(host: String?, port: Int, reuseAddress: Boolean): LyngUdpSocket {
+        val bindHost = host ?: "0.0.0.0"
+        val socket = aSocket(selectorManager).udp().bind(bindHost, port) {
+            this.reuseAddress = reuseAddress
+        }
+        return NativeLyngUdpSocket(socket)
+    }
+}
+
+private class NativeLyngTcpSocket(
+    private val socket: Socket,
+) : LyngTcpSocket {
+    private val input: ByteReadChannel by lazy { socket.openReadChannel() }
+    private val output: ByteWriteChannel by lazy { socket.openWriteChannel(autoFlush = true) }
+
+    override fun isOpen(): Boolean = !socket.isClosed
+
+    override fun localAddress(): LyngSocketAddress = socket.localAddress.toLyngSocketAddress(resolved = true)
+
+    override fun remoteAddress(): LyngSocketAddress = socket.remoteAddress.toLyngSocketAddress(resolved = true)
+
+    override suspend fun read(maxBytes: Int): ByteArray? {
+        if (!input.awaitContent(1)) return null
+        val buffer = ByteArray(maxBytes)
+        val count = input.readAvailable(buffer, 0, maxBytes)
+        return when {
+            count <= 0 -> null
+            count == maxBytes -> buffer
+            else -> buffer.copyOf(count)
+        }
+    }
+
+    override suspend fun readLine(): String? = input.readUTF8Line()
+
+    override suspend fun write(data: ByteArray) {
+        output.writeFully(data, 0, data.size)
+    }
+
+    override suspend fun writeUtf8(text: String) {
+        output.writeStringUtf8(text)
+    }
+
+    override suspend fun flush() {
+        output.flush()
+    }
+
+    override fun close() {
+        socket.close()
+    }
+}
+
+private class NativeLyngTcpServer(
+    private val server: ServerSocket,
+) : LyngTcpServer {
+    override fun isOpen(): Boolean = !server.isClosed
+
+    override fun localAddress(): LyngSocketAddress = server.localAddress.toLyngSocketAddress(resolved = true)
+
+    override suspend fun accept(): LyngTcpSocket = NativeLyngTcpSocket(server.accept())
+
+    override fun close() {
+        server.close()
+    }
+}
+
+private class NativeLyngUdpSocket(
+    private val socket: BoundDatagramSocket,
+) : LyngUdpSocket {
+    override fun isOpen(): Boolean = !socket.isClosed
+
+    override fun localAddress(): LyngSocketAddress = socket.localAddress.toLyngSocketAddress(resolved = true)
+
+    override suspend fun receive(maxBytes: Int): LyngDatagram? {
+        val datagram = try {
+            socket.receive()
+        } catch (e: Throwable) {
+            if (!isOpen()) return null
+            throw e
+        }
+        val bytes = datagram.packet.readByteArray().let {
+            if (it.size <= maxBytes) it else it.copyOf(maxBytes)
+        }
+        return LyngDatagram(bytes, datagram.address.toLyngSocketAddress(resolved = true))
+    }
+
+    override suspend fun send(data: ByteArray, host: String, port: Int) {
+        val packet = Buffer()
+        packet.write(data)
+        socket.send(Datagram(packet, InetSocketAddress(host, port)))
+    }
+
+    override fun close() {
+        socket.close()
+    }
+}
+
+private fun SocketAddress.toLyngSocketAddress(resolved: Boolean): LyngSocketAddress {
+    val inetAddress = this as? InetSocketAddress
+    if (inetAddress != null) {
+        val rawAddress = inetAddress.resolveAddress()
+        val host = rawAddress?.toIpHostString() ?: inetAddress.hostname
+        return LyngSocketAddress(
+            host = host,
+            port = inetAddress.port,
+            ipVersion = rawAddress?.toLyngIpVersion()
+                ?: if (host.contains(':')) LyngIpVersion.IPV6 else LyngIpVersion.IPV4,
+            resolved = resolved,
+        )
+    }
+
+    val rendered = toString()
+    return LyngSocketAddress(
+        host = rendered,
+        port = 0,
+        ipVersion = if (rendered.contains(':')) LyngIpVersion.IPV6 else LyngIpVersion.IPV4,
+        resolved = resolved,
+    )
+}
+
+private fun ByteArray.toLyngIpVersion(): LyngIpVersion = if (size == 16) LyngIpVersion.IPV6 else LyngIpVersion.IPV4
+
+private fun ByteArray.toIpHostString(): String = when (size) {
+    4 -> joinToString(".") { (it.toInt() and 0xff).toString() }
+    16 -> (0 until 8).joinToString(":") { index ->
+        val hi = this[index * 2].toInt() and 0xff
+        val lo = this[index * 2 + 1].toInt() and 0xff
+        ((hi shl 8) or lo).toString(16)
+    }
+    else -> error("Unsupported IP address length: $size")
+}

notes/networking_handoff_2026-04-02.md

@@ -0,0 +1,205 @@
+# Networking Handoff
+
+Date: 2026-04-02
+Commit: `5346d15` (`Add KMP networking backends`)
+
+## Scope completed
+
+The `lyngio` networking work now provides a uniform Lyng-facing API with capability probes and platform-specific implementations.
+
+Implemented modules:
+
+- `lyng.io.http`
+- `lyng.io.ws`
+- `lyng.io.net`
+
+## Current support matrix
+
+### HTTP / HTTPS
+
+- JVM: supported
+- Android: supported
+- JS: supported
+- Linux Native: supported
+- Windows Native (`mingwX64`): supported
+- Apple Native: compile-verified on this Linux host
+
+### WS / WSS
+
+- JVM: supported
+- Android: supported
+- JS: supported
+- Linux Native: supported
+- Windows Native (`mingwX64`): supported
+- Apple Native: compile-verified on this Linux host
+
+### Raw networking (`lyng.io.net`)
+
+- JVM: supported
+- Android: supported
+- JS/Node: supported
+- JS/browser: unsupported by capability probe
+- Linux Native: supported
+- Apple Native: enabled via shared native backend; compile-verified, runtime not yet host-verified
+- Other Native targets: intentionally still unsupported
+
+## Important design decisions
+
+- Ktor is the backend for all currently implemented networking.
+- API is uniform across targets; platform variance is exposed through capability checks such as:
+  - `Http.isSupported()`
+  - `Ws.isSupported()`
+  - `Net.isSupported()`
+  - `Net.isTcpAvailable()`
+  - `Net.isTcpServerAvailable()`
+  - `Net.isUdpAvailable()`
+- Native support was restricted to what matches Ktor client-engine support:
+  - Darwin for Apple Native
+  - Curl for Linux Native
+  - WinHttp for Windows Native
+- Native raw sockets use a shared Ktor socket implementation for Linux and Darwin source sets.
+- Capability probes are enabled on Linux Native and Apple Native; Apple Native is compile-verified but not yet runtime-tested on a macOS host.
+
+## Documentation and tests status
+
+Docs updated:
+
+- `docs/lyng.io.http.md`
+- `docs/lyng.io.ws.md`
+- `docs/lyng.io.net.md`
+
+Verified docs/tests:
+
+- HTTP/HTTPS docs are covered with extracted markdown tests on JVM.
+- WS/WSS docs are covered with extracted markdown tests on JVM.
+- JS/Node has both engine-level and Lyng-module-level tests for raw networking.
+
+## Key implementation files
+
+Shared:
+
+- `lyngio/src/commonMain/kotlin/net/sergeych/lyngio/http/LyngHttp.kt`
+- `lyngio/src/commonMain/kotlin/net/sergeych/lyng/io/http/LyngHttpModule.kt`
+- `lyngio/src/commonMain/kotlin/net/sergeych/lyngio/ws/LyngWs.kt`
+- `lyngio/src/commonMain/kotlin/net/sergeych/lyngio/net/LyngNet.kt`
+- `lyngio/build.gradle.kts`
+- `gradle/libs.versions.toml`
+
+Platform HTTP:
+
+- `lyngio/src/jvmMain/kotlin/net/sergeych/lyngio/http/PlatformJvm.kt`
+- `lyngio/src/jsMain/kotlin/net/sergeych/lyngio/http/PlatformJs.kt`
+- `lyngio/src/androidMain/kotlin/net/sergeych/lyngio/http/PlatformAndroid.kt`
+- `lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/http/PlatformDarwin.kt`
+- `lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/http/PlatformLinux.kt`
+- `lyngio/src/mingwMain/kotlin/net/sergeych/lyngio/http/PlatformMingw.kt`
+
+Platform WS:
+
+- `lyngio/src/jvmMain/kotlin/net/sergeych/lyngio/ws/PlatformJvm.kt`
+- `lyngio/src/jsMain/kotlin/net/sergeych/lyngio/ws/PlatformJs.kt`
+- `lyngio/src/androidMain/kotlin/net/sergeych/lyngio/ws/PlatformAndroid.kt`
+- `lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/ws/PlatformDarwin.kt`
+- `lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/ws/PlatformLinux.kt`
+- `lyngio/src/mingwMain/kotlin/net/sergeych/lyngio/ws/PlatformMingw.kt`
+
+Platform raw net:
+
+- `lyngio/src/jvmMain/kotlin/net/sergeych/lyngio/net/PlatformJvm.kt`
+- `lyngio/src/jsMain/kotlin/net/sergeych/lyngio/net/PlatformJs.kt`
+- `lyngio/src/androidMain/kotlin/net/sergeych/lyngio/net/PlatformAndroid.kt`
+- `lyngio/src/nativeMain/kotlin/net/sergeych/lyngio/net/NativeKtorNetEngine.kt`
+- `lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/net/PlatformLinux.kt`
+- `lyngio/src/darwinMain/kotlin/net/sergeych/lyngio/net/PlatformDarwin.kt`
+- `lyngio/src/mingwMain/kotlin/net/sergeych/lyngio/net/PlatformMingw.kt`
+
+JS tests:
+
+- `lyngio/src/jsTest/kotlin/net/sergeych/lyngio/PlatformCapabilityJsTest.kt`
+- `lyngio/src/jsTest/kotlin/net/sergeych/lyngio/NetJsNodeTest.kt`
+- `lyngio/src/jsTest/kotlin/net/sergeych/lyng/io/net/LyngNetModuleJsNodeTest.kt`
+
+JVM tests:
+
+- `lyngio/src/jvmTest/kotlin/LyngioBookTest.kt`
+- `lyngio/src/jvmTest/kotlin/net/sergeych/lyng/io/http/LyngHttpModuleTest.kt`
+- `lyngio/src/jvmTest/kotlin/net/sergeych/lyng/io/ws/LyngWsModuleTest.kt`
+- `lyngio/src/jvmTest/kotlin/net/sergeych/lyng/io/net/LyngNetModuleTest.kt`
+
+Linux Native tests:
+
+- `lyngio/src/linuxTest/kotlin/net/sergeych/lyngio/net/NetLinuxNativeTest.kt`
+
+## Verification already run
+
+JVM / docs:
+
+- `./gradlew :lyngio:jvmTest --tests LyngioBookTest`
+- `./gradlew :lyngio:jvmTest --tests net.sergeych.lyng.io.http.LyngHttpModuleTest`
+- `./gradlew :lyngio:jvmTest --tests net.sergeych.lyng.io.ws.LyngWsModuleTest`
+- `./gradlew :lyngio:jvmTest --tests net.sergeych.lyng.io.net.LyngNetModuleTest`
+
+JS:
+
+- `./gradlew :lyngio:compileKotlinJs`
+- `./gradlew :lyngio:compileTestKotlinJs`
+- `./gradlew :lyngio:jsNodeTest`
+- `./gradlew kotlinUpgradeYarnLock`
+
+Android:
+
+- `./gradlew :lyngio:compileDebugKotlinAndroid`
+- `./gradlew :lyngio:compileReleaseKotlinAndroid`
+
+Native:
+
+- `./gradlew :lyngio:compileKotlinLinuxX64`
+- `./gradlew :lyngio:compileKotlinLinuxArm64`
+- `./gradlew :lyngio:compileKotlinMingwX64`
+- `./gradlew :lyngio:compileKotlinIosX64`
+- `./gradlew :lyngio:compileKotlinIosArm64`
+- `./gradlew :lyngio:compileKotlinIosSimulatorArm64`
+- `./gradlew :lyngio:compileKotlinMacosArm64`
+- `./gradlew :lyngio:compileTestKotlinLinuxX64`
+- `./gradlew :lyngio:compileTestKotlinLinuxArm64`
+- `./gradlew :lyngio:linkDebugTestLinuxX64`
+- `./gradlew :lyngio:linuxX64Test`
+- `./gradlew :lyngio:linuxX64Test --tests net.sergeych.lyngio.net.NetLinuxNativeTest`
+- `./gradlew :lyngio:linuxX64Test --tests net.sergeych.lyngio.net.NetLinuxNativeTest.testLinuxNativeTcpAndUdpLoopback`
+- `./lyngio/build/bin/linuxX64/debugTest/test.kexe --ktest_filter='net.sergeych.lyngio.net.NetLinuxNativeTest.*'`
+
+## Known intentional gaps
+
+- Native raw sockets are enabled on Linux Native and Apple Native.
+- Apple Native raw networking is enabled based on shared-backend compile verification; runtime verification on macOS is still pending.
+- No Android device/instrumented runtime tests were added; only compile verification was done.
+
+## Worktree state after commit
+
+Current HEAD:
+
+- `5346d15` `Add KMP networking backends`
+
+Unrelated remaining change:
+
+- `examples/tetris_console.lyng`
+
+That file was not touched by the networking work and was intentionally left out of the commit.
+
+## Recommended next steps
+
+1. Add Native raw socket support only per target that compiles and passes a smoke test.
+2. Keep capability probes `false` on non-Linux Native targets until each raw-socket backend is proven.
+3. If Apple Native work continues, compile Darwin targets on a macOS host before claiming support.
+4. Run a macOS-hosted runtime smoke test when available to verify the already-enabled Darwin backend.
+5. Optionally add Android runtime tests later; compile-only verification exists now.
+
+## Suggested first task for the next chat
+
+Continue Native raw `lyng.io.net` incrementally from the verified Linux baseline:
+
+- keep Linux Native enabled
+- keep Apple Native enabled unless runtime verification disproves the shared-backend assumption
+- keep other Native targets capability-gated off until compiled and smoke-tested
+- use only `ktor-network` support that actually compiles
+- do not change the Lyng-facing API