KTOR-8490 Do not parse ipString (#4912)

Author: osipxd

ktor-io/posix/src/io/ktor/utils/io/errors/PosixErrors.kt

@@ -4,10 +4,10 @@
 
 package io.ktor.utils.io.errors
 
-import kotlinx.cinterop.*
-import kotlinx.io.*
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.memScoped
+import kotlinx.cinterop.toKString
 import platform.posix.*
-import kotlin.native.concurrent.*
 
 private val KnownPosixErrors = mapOf(
     EBADF to "EBADF",
@@ -78,7 +78,7 @@ public sealed class PosixException(public val errno: Int, message: String) : Exc
          *
          * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.utils.io.errors.PosixException.Companion.forErrno)
          *
-         * @param errno error code returned by [posix.platform.errno]
+         * @param errno error code returned by [platform.posix.errno]
          * @param posixFunctionName optional function name to be included to the exception message
          * @return an instance of [PosixException] or it's subtype
          */

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

@@ -51,12 +51,12 @@ public expect class InetSocketAddress(
     /**
      * 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.
+     * 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.
+     * Always returns `null` for Kotlin/JS and Kotlin/Wasm targets.
      *
-     * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.network.sockets.InetSocketAddress.address)
+     * [Report a problem](https://ktor.io/feedback/?fqname=io.ktor.network.sockets.InetSocketAddress.resolveAddress)
      */
     public fun resolveAddress(): ByteArray?
 

ktor-network/common/test/io/ktor/network/sockets/tests/InetSocketAddressTest.kt

@@ -0,0 +1,36 @@
+/*
+ * 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.tests
+
+import io.ktor.network.sockets.*
+import io.ktor.util.*
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+
+class InetSocketAddressTest {
+
+    @BeforeTest
+    fun setUp() {
+        initSocketsIfNeeded()
+    }
+
+    @Test
+    fun testResolveAddress() {
+        // Address resolving is not supported on JS and WASM platforms
+        if (PlatformUtils.IS_JS || PlatformUtils.IS_WASM_JS) return
+
+        val testCases = listOf(
+            "127.0.0.1" to byteArrayOf(127, 0, 0, 1),
+            "::1" to byteArrayOf(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1),
+        )
+
+        for ((hostname, expectedBytes) in testCases) {
+            val address = InetSocketAddress(hostname, 8080)
+            val resolved = address.resolveAddress()
+            assertContentEquals(expectedBytes, resolved, "Unexpected bytes for the address '$hostname'")
+        }
+    }
+}

ktor-network/common/test/io/ktor/network/sockets/tests/TestUtils.kt

@@ -35,3 +35,5 @@ internal fun createTempFilePath(basename: String): String {
 internal fun removeFile(path: String) {
     SystemFileSystem.delete(Path(path), mustExist = false)
 }
+
+internal expect fun initSocketsIfNeeded()

ktor-network/jsAndWasmShared/test/io/ktor/network/sockets/tests/TestUtils.jsAndWasmShared.kt

@@ -5,3 +5,5 @@
 package io.ktor.network.sockets.tests
 
 internal actual fun Throwable.isPosixException(): Boolean = false
+
+actual fun initSocketsIfNeeded() {}

ktor-network/jvm/test/io/ktor/network/sockets/tests/TestUtilsJvm.kt

@@ -5,3 +5,5 @@
 package io.ktor.network.sockets.tests
 
 internal actual fun Throwable.isPosixException(): Boolean = false
+
+actual fun initSocketsIfNeeded() {}

ktor-network/nix/src/io/ktor/network/util/NativeSocketAddressNix.kt

@@ -28,6 +28,10 @@ internal actual class NativeIPv4SocketAddress(
         }
     }
 
+    @OptIn(ExperimentalForeignApi::class)
+    actual override val rawAddressBytes: ByteArray
+        get() = cValue<in_addr> { s_addr = address }.getBytes()
+
     @OptIn(ExperimentalForeignApi::class)
     actual override val ipString: String
         get() = memScoped {
@@ -45,18 +49,17 @@ internal actual class NativeIPv4SocketAddress(
         }
 }
 
-@OptIn(UnsafeNumber::class)
+@OptIn(UnsafeNumber::class, ExperimentalForeignApi::class)
 internal actual class NativeIPv6SocketAddress(
     family: UByte,
-    private val rawAddress: in6_addr,
+    private val rawAddress: CValue<in6_addr>,
     port: Int,
     private val flowInfo: uint32_t,
     private val scopeId: uint32_t
 ) : NativeInetSocketAddress(family, port) {
 
     override fun toString(): String = "NativeIPv6SocketAddress[$ipString:$port]"
 
-    @OptIn(ExperimentalForeignApi::class)
     actual override fun nativeAddress(block: (address: CPointer<sockaddr>, size: UInt) -> Unit) {
         cValue<sockaddr_in6> {
             sin6_family = family.convert()
@@ -68,7 +71,9 @@ internal actual class NativeIPv6SocketAddress(
         }
     }
 
-    @OptIn(ExperimentalForeignApi::class)
+    actual override val rawAddressBytes: ByteArray
+        get() = rawAddress.getBytes()
+
     actual override val ipString: String
         get() = memScoped {
             val string = allocArray<ByteVar>(INET6_ADDRSTRLEN)

ktor-network/nix/src/io/ktor/network/util/SocketUtils.nix.kt

@@ -59,7 +59,7 @@ internal actual fun sockaddr.toNativeSocketAddress(): NativeSocketAddress = when
         val address = ptr.reinterpret<sockaddr_in6>().pointed
         NativeIPv6SocketAddress(
             address.sin6_family.convert(),
-            address.sin6_addr,
+            address.sin6_addr.readValue(),
             networkToHostOrder(address.sin6_port).toInt(),
             address.sin6_flowinfo,
             address.sin6_scope_id

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

@@ -4,17 +4,12 @@
 
 package io.ktor.network.sockets
 
-import io.ktor.network.util.NativeIPv4SocketAddress
-import io.ktor.network.util.NativeIPv6SocketAddress
-import io.ktor.network.util.parseIPv4String
-import io.ktor.network.util.parseIPv6String
-import io.ktor.network.util.resolve
+import io.ktor.network.util.*
 
 internal actual fun InetSocketAddress.platformResolveAddress(): ByteArray? {
     return this.resolve().firstOrNull()?.let {
         when (it) {
-            is NativeIPv4SocketAddress -> parseIPv4String(it.ipString)
-            is NativeIPv6SocketAddress -> parseIPv6String(it.ipString)
+            is NativeInetSocketAddress -> it.rawAddressBytes
             else -> null
         }
     }

ktor-network/posix/src/io/ktor/network/util/NativeSocketAddress.kt

@@ -5,8 +5,10 @@
 package io.ktor.network.util
 
 import io.ktor.network.sockets.*
-import kotlinx.cinterop.*
-import platform.posix.*
+import kotlinx.cinterop.CPointer
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.convert
+import platform.posix.sockaddr
 
 /**
  * Represents a native socket address.
@@ -23,18 +25,21 @@ internal abstract class NativeInetSocketAddress(
     family: UByte,
     val port: Int
 ) : NativeSocketAddress(family) {
-    internal abstract val ipString: String
+    abstract val rawAddressBytes: ByteArray
+    abstract val ipString: String
 }
 
 internal expect class NativeIPv4SocketAddress : NativeInetSocketAddress {
     @OptIn(ExperimentalForeignApi::class)
     override fun nativeAddress(block: (address: CPointer<sockaddr>, size: UInt) -> Unit)
+    override val rawAddressBytes: ByteArray
     override val ipString: String
 }
 
 internal expect class NativeIPv6SocketAddress : NativeInetSocketAddress {
     @OptIn(ExperimentalForeignApi::class)
     override fun nativeAddress(block: (address: CPointer<sockaddr>, size: UInt) -> Unit)
+    override val rawAddressBytes: ByteArray
     override val ipString: String
 }
 

ktor-network/posix/src/io/ktor/network/util/SocketAddressUtils.kt

@@ -19,48 +19,3 @@ internal fun SocketAddress.resolve(): List<NativeSocketAddress> = when (this) {
     is InetSocketAddress -> getAddressInfo(hostname, port)
     is UnixSocketAddress -> listOf(NativeUnixSocketAddress(AF_UNIX.convert(), path))
 }
-
-internal fun parseIPv4String(ipString: String): ByteArray? {
-    return try {
-        val octets = ipString.split('.').also {
-            require(it.size == 4) { "Invalid IPv4 string: $ipString" }
-        }
-
-        octets.map { it.toUByte().toByte() }.toByteArray()
-    } catch (_: Throwable) {
-        null
-    }
-}
-
-internal fun parseIPv6String(ipString: String): ByteArray? {
-    return try {
-        val groups = if ("::" in ipString) {
-            val parts = ipString.split("::", limit = 2)
-
-            val groups = Pair(
-                if (parts[0].isNotEmpty()) parts[0].split(':') else emptyList(),
-                if (parts.size > 1 && parts[1].isNotEmpty()) parts[1].split(':') else emptyList()
-            )
-
-            val totalGroups = groups.first.size + groups.second.size
-            val emptyGroups = 8 - totalGroups
-
-            groups.first + List(emptyGroups) { "0" } + groups.second
-        } else {
-            ipString.split(':').also {
-                require(it.size == 8) { "Invalid IPv6 string: $ipString" }
-            }
-        }
-
-        groups.flatMap {
-            val int = if (it.matches(Regex("^[0-9a-fA-f]+$"))) {
-                it.toUShort(16)
-            } else {
-                return null
-            }.toInt()
-            listOf((int shr 8).toByte(), int.toByte())
-        }.toByteArray()
-    } catch (_: Throwable) {
-        null
-    }
-}

ktor-network/posix/test/io/ktor/network/sockets/tests/IPStringParseTest.kt

@@ -0,0 +1,7 @@
+/*
+ * 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.tests
+
+actual fun initSocketsIfNeeded() = io.ktor.network.util.initSocketsIfNeeded()

ktor-network/posix/test/io/ktor/network/sockets/tests/TestUtils.posix.kt

@@ -6,7 +6,10 @@ package io.ktor.network.util
 
 import kotlinx.cinterop.*
 import platform.posix.*
-import platform.windows.*
+import platform.windows.INET6_ADDRSTRLEN
+import platform.windows.INET_ADDRSTRLEN
+import platform.windows.in6_addr
+import platform.windows.sockaddr_in6
 
 internal actual class NativeIPv4SocketAddress(
     family: UByte,
@@ -28,6 +31,10 @@ internal actual class NativeIPv4SocketAddress(
         }
     }
 
+    @OptIn(ExperimentalForeignApi::class)
+    actual override val rawAddressBytes: ByteArray
+        get() = cValue<in_addr> { S_un.S_addr = address }.getBytes()
+
     @OptIn(ExperimentalForeignApi::class)
     actual override val ipString: String
         get() = memScoped {
@@ -45,17 +52,17 @@ internal actual class NativeIPv4SocketAddress(
         }
 }
 
+@OptIn(ExperimentalForeignApi::class)
 internal actual class NativeIPv6SocketAddress(
     family: UByte,
-    private val rawAddress: in6_addr,
+    private val rawAddress: CValue<in6_addr>,
     port: Int,
     private val flowInfo: uint32_t,
     private val scopeId: uint32_t
 ) : NativeInetSocketAddress(family, port) {
 
     override fun toString(): String = "NativeIPv6SocketAddress[$ipString:$port]"
 
-    @OptIn(ExperimentalForeignApi::class)
     actual override fun nativeAddress(block: (address: CPointer<sockaddr>, size: UInt) -> Unit) {
         cValue<sockaddr_in6> {
             sin6_family = family.convert()
@@ -67,7 +74,9 @@ internal actual class NativeIPv6SocketAddress(
         }
     }
 
-    @OptIn(ExperimentalForeignApi::class)
+    actual override val rawAddressBytes: ByteArray
+        get() = rawAddress.getBytes()
+
     actual override val ipString: String
         get() = memScoped {
             val string = allocArray<ByteVar>(INET6_ADDRSTRLEN)