diff a/src/java.base/macosx/classes/jdk/internal/sys/in_h$constants.java b/src/java.base/macosx/classes/jdk/internal/sys/in_h$constants.java
--- /dev/null
+++ b/src/java.base/macosx/classes/jdk/internal/sys/in_h$constants.java
@@ -0,0 +1,43 @@
+
+// Generatable but for now somewhat handcrafted to encapsulate the layouts
+// generated by JStruct, with some additional memory handles and accessors to
+// mirror that of the what jextract generates as dynamic constants.
+package jdk.internal.sys;
+
+import jdk.incubator.foreign.MemoryLayout;
+import jdk.incubator.foreign.MemoryLayout.PathElement;
+import jdk.incubator.foreign.MemoryLayouts;
+import java.lang.invoke.VarHandle;
+
+final class in_h$constants {
+
+    private static final MemoryLayout Cin_addr$LAYOUT = MemoryLayout.ofStruct(
+        MemoryLayouts.BITS_32_BE.withName("s_addr")  // network byte order
+    ).withName("in_addr");
+    private static final VarHandle VH_s_addr = Cin_addr$LAYOUT.varHandle(int.class, PathElement.groupElement("s_addr"));
+    static final MemoryLayout Cin_addr$LAYOUT() { return Cin_addr$LAYOUT; }
+    static final VarHandle s_addr$VH() {
+        return VH_s_addr;
+    }
+
+    private static final MemoryLayout Csockaddr_in$LAYOUT = MemoryLayout.ofStruct(
+        MemoryLayouts.BITS_8_LE.withName("sin_len"),
+        MemoryLayouts.BITS_8_LE.withName("sin_family"),
+        MemoryLayouts.BITS_16_BE.withName("sin_port"), // network byte order
+        Cin_addr$LAYOUT,
+        MemoryLayout.ofSequence(8, MemoryLayouts.BITS_8_LE).withName("sin_zero")
+    ).withName("sockaddr_in");
+    private static final VarHandle sin_len$VH = Csockaddr_in$LAYOUT.varHandle(byte.class, PathElement.groupElement("sin_len"));
+    private static final VarHandle sin_family$VH = Csockaddr_in$LAYOUT.varHandle(byte.class, PathElement.groupElement("sin_family"));
+    private static final VarHandle sin_port$VH = Csockaddr_in$LAYOUT.varHandle(short.class, PathElement.groupElement("sin_port"));
+    static MemoryLayout Csockaddr_in$LAYOUT() { return Csockaddr_in$LAYOUT; }
+    static final VarHandle sin_len$VH() {
+        return sin_len$VH;
+    }
+    static final VarHandle sin_family$VH() {
+        return sin_family$VH;
+    }
+    static final VarHandle sin_port$VH() {
+        return sin_port$VH;
+    }
+}