better local address fetching

DatL4g · Jul 20, 2024 · 6282421 · 6282421
1 parent ea4de6b
commit 6282421
Showing 1 changed file with 41 additions and 11 deletions.
diff --git a/src/jvmMain/kotlin/dev/datlag/k2k/NetInterface.jvm.kt b/src/jvmMain/kotlin/dev/datlag/k2k/NetInterface.jvm.kt
@@ -3,25 +3,55 @@ package dev.datlag.k2k
 import dev.datlag.tooling.scopeCatching
 import kotlinx.collections.immutable.ImmutableSet
 import kotlinx.collections.immutable.toImmutableSet
+import java.net.Inet4Address
 import java.net.InetAddress
 import java.net.NetworkInterface
 
 actual object NetInterface {
     actual fun getAddresses(): ImmutableSet<String> {
-        return NetworkInterface.getNetworkInterfaces().toList().filterNotNull().mapNotNull {
-            scopeCatching {
-                if (it.isLoopback || !it.isUp) {
-                    return@scopeCatching null
-                }
+        return scopeCatching {
+            NetworkInterface.getNetworkInterfaces().toList().filterNotNull().mapNotNull {
+                scopeCatching loop@{
+                    if (it.isLoopback || !it.isUp) {
+                        return@loop null
+                    }
 
-                it.interfaceAddresses.mapNotNull { all ->
-                    all?.broadcast?.hostAddress?.ifBlank { null }
-                }
-            }.getOrNull()
-        }.flatten().toImmutableSet()
+                    it.interfaceAddresses.mapNotNull { all ->
+                        all?.broadcast?.hostAddress?.ifBlank { null }
+                    }
+                }.getOrNull()
+            }.flatten()
+        }.getOrNull().orEmpty().toImmutableSet()
     }
 
     actual fun getLocalAddress(): String {
-        return InetAddress.getLocalHost().hostAddress
+        val allAvailable = mutableSetOf<String>()
+        val interfaces = scopeCatching {
+            NetworkInterface.getNetworkInterfaces()
+        }.getOrNull() ?: return InetAddress.getLocalHost().hostAddress
+
+        for (inter in interfaces) {
+            if (inter == null) {
+                continue
+            }
+
+            for (inet in inter.inetAddresses) {
+                if (inet == null) {
+                    continue
+                }
+
+                if (!inet.isLoopbackAddress && inet is Inet4Address) {
+                    inet.hostAddress?.ifBlank { null }?.let(allAvailable::add)
+                }
+            }
+        }
+
+        if (allAvailable.isEmpty()) {
+            return InetAddress.getLocalHost().hostAddress
+        }
+
+        return allAvailable.singleOrNull() ?: scopeCatching {
+            InetAddress.getLocalHost().hostAddress?.ifBlank { null }
+        }.getOrNull() ?: allAvailable.first()
     }
 }