KTOR-8490 Add SocketAddress::address

ktor-network/api/ktor-network.api

@@ -201,6 +201,7 @@ public final class io/ktor/network/sockets/InetSocketAddress : io/ktor/network/s
 	public final fun getHostname ()Ljava/lang/String;
 	public final fun getPort ()I
 	public fun hashCode ()I
+	public final fun resolveAddress ()[B
 	public fun toString ()Ljava/lang/String;
 }
 

ktor-network/api/ktor-network.klib.api

@@ -135,6 +135,7 @@ final class io.ktor.network.sockets/InetSocketAddress : io.ktor.network.sockets/
     final fun copy(kotlin/String = ..., kotlin/Int = ...): io.ktor.network.sockets/InetSocketAddress // io.ktor.network.sockets/InetSocketAddress.copy|copy(kotlin.String;kotlin.Int){}[0]
     final fun equals(kotlin/Any?): kotlin/Boolean // io.ktor.network.sockets/InetSocketAddress.equals|equals(kotlin.Any?){}[0]
     final fun hashCode(): kotlin/Int // io.ktor.network.sockets/InetSocketAddress.hashCode|hashCode(){}[0]
+    final fun resolveAddress(): kotlin/ByteArray? // io.ktor.network.sockets/InetSocketAddress.resolveAddress|resolveAddress(){}[0]
     final fun toString(): kotlin/String // io.ktor.network.sockets/InetSocketAddress.toString|toString(){}[0]
 }
 

ktor-network/common/src/io/ktor/network/sockets/SocketAddress.kt

@@ -48,6 +48,18 @@ public expect class InetSocketAddress(
      */
     public val port: Int
 
+    /**
+     * Returns the raw IP address bytes of this socket address.
+     *
+     * The returned array is 4 bytes for IPv4 addresses and 16 bytes for IPv6 addresses.
+     * Returns null if the address cannot be resolved or is not a valid IP address.
+     *
+     * Always returns null for wasm/js targets.
+     *
+     * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.network.sockets.InetSocketAddress.address)
+     */
+    public fun resolveAddress(): ByteArray?
+
     /**
      * The hostname of the socket address.
      *

ktor-network/jsAndWasmShared/src/io/ktor/network/sockets/SocketAddress.nonJvm.jsAndWasmShared.kt

@@ -5,3 +5,7 @@
 package io.ktor.network.sockets
 
 internal actual fun isUnixSocketSupported(): Boolean = false
+
+internal actual fun InetSocketAddress.platformResolveAddress(): ByteArray? {
+    return null
+}

ktor-network/jvm/src/io/ktor/network/sockets/SocketAddressJvm.kt

@@ -19,6 +19,8 @@ public actual class InetSocketAddress internal constructor(
 
     public actual val port: Int get() = address.port
 
+    public actual fun resolveAddress(): ByteArray? = address.address?.address
+
     public actual constructor(hostname: String, port: Int) :
         this(java.net.InetSocketAddress(hostname, port))
 

ktor-network/nonJvm/src/io/ktor/network/sockets/SocketAddress.nonJvm.kt

@@ -10,6 +10,10 @@ public actual class InetSocketAddress actual constructor(
     public actual val hostname: String,
     public actual val port: Int
 ) : SocketAddress() {
+    public actual fun resolveAddress(): ByteArray? {
+        return platformResolveAddress()
+    }
+
     /**
      * Create a copy of [InetSocketAddress].
      *
@@ -100,3 +104,5 @@ public actual class UnixSocketAddress actual constructor(
 }
 
 internal expect fun isUnixSocketSupported(): Boolean
+
+internal expect fun InetSocketAddress.platformResolveAddress(): ByteArray?

ktor-network/posix/src/io/ktor/network/sockets/SocketAddress.nonJvm.posix.kt

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2014-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.network.sockets
+
+import io.ktor.network.util.NativeIPv4SocketAddress
+import io.ktor.network.util.NativeIPv6SocketAddress
+import io.ktor.network.util.resolve
+
+internal actual fun InetSocketAddress.platformResolveAddress(): ByteArray? {
+    return this.resolve().firstOrNull()?.let {
+        when (it) {
+            is NativeIPv4SocketAddress -> {
+                try {
+                    val octets = it.ipString.split('.', limit = 4).map { o ->
+                        o.toUByte().toByte()
+                    }
+
+                    List(4) { i ->
+                        octets.getOrElse(i) { 0 }
+                    }.toByteArray()
+                } catch (_: Throwable) {
+                    null
+                }
+            }
+            is NativeIPv6SocketAddress -> {
+                try {
+                    val groups = it.ipString.split(':', limit = 8)
+                    val emptyGroups = 8 - groups.count { g -> g.isNotEmpty() }
+
+                    val bytes = groups.flatMap { g ->
+                        if (g.isEmpty()) {
+                            List(emptyGroups * 2) { 0 }
+                        } else {
+                            val int = g.toInt(16)
+                            listOf((int shr 8).toByte(), int.toByte())
+                        }
+                    }
+                    List(16) { i -> bytes.getOrElse(i) { 0 } }.toByteArray()
+                } catch (_: Throwable) {
+                    null
+                }
+            }
+            else -> null
+        }
+    }
+}