1 files changed, 40 insertions, 0 deletions
diff --git a/src/main/java/io/trygvis/rules/network/Ipv4Cidr.java b/src/main/java/io/trygvis/rules/network/Ipv4Cidr.java
new file mode 100644
index 0000000..34b3a0b
--- /dev/null
+++ b/src/main/java/io/trygvis/rules/network/Ipv4Cidr.java
@@ -0,0 +1,40 @@
+package io.trygvis.rules.network;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.Collection;
+
+public class Ipv4Cidr {
+    public final int network;
+    public final int netmask;
+    public final int size;
+    public final int bits;
+
+    public Ipv4Cidr(int network, int netmask, int size, int bits) {
+        this.network = network;
+        this.netmask = netmask;
+        this.size = size;
+        this.bits = bits;
+    }
+
+    @Override
+    public String toString() {
+        return "%d.%d.%d.%d/%d".formatted(
+                network >> 24 & 0xff,
+                network >> 16 & 0xff,
+                network >> 8 & 0xff,
+                network & 0xff,
+                bits);
+    }
+
+    public Collection<Ipv4Address> addresses() {
+        var end = network + size;
+        var addresses = new ArrayList<Ipv4Address>(size);
+        for (int address = network; address < end; address++) {
+            addresses.add(new Ipv4Address(address));
+        }
+
+        return addresses;
+    }
+}