Generating IP addresses.

4 files changed, 150 insertions, 3 deletions

diff --git a/src/main/java/io/trygvis/rules/acme/IpCalc.java b/src/main/java/io/trygvis/rules/acme/IpCalc.java
new file mode 100644
index 0000000..5369d62
--- /dev/null
+++ b/src/main/java/io/trygvis/rules/acme/IpCalc.java
@@ -0,0 +1,67 @@
+package io.trygvis.rules.acme;
+
+import io.trygvis.rules.network.Ipv4Cidr;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+public class IpCalc {
+    private static final Pattern pattern = Pattern.compile("([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})/([0-9]{1,3})");
+
+    public static class FirstLast {
+        public final int first;
+        public final int last;
+
+        public FirstLast(int first, int last) {
+            this.first = first;
+            this.last = last;
+        }
+    }
+
+    public static Ipv4Cidr cidr(String cidr) {
+        var matcher = pattern.matcher(cidr);
+        if (!matcher.matches()) {
+            throw new IllegalArgumentException("Not a CIDR: " + cidr);
+        }
+
+        var b1 = matcher.group(1);
+        var b2 = matcher.group(2);
+        var b3 = matcher.group(3);
+        var b4 = matcher.group(4);
+
+        int network = parse(b1) << 24 |
+                parse(b2) << 16 |
+                parse(b3) << 8 |
+                parse(b4);
+
+//        System.out.printf("network = %x%n", network);
+
+        var l = matcher.group(5);
+        var bits = Integer.parseInt(l);
+        var hostBits = 32 - bits;
+        int size = 1 << hostBits;
+
+        int netmask = (-1 >> hostBits) << hostBits;
+//        System.out.printf("netmask = %08x%n", netmask);
+
+        int x = network & ~netmask;
+
+        if (x != 0) {
+            throw new IllegalArgumentException("Not a CIDR: " + cidr);
+        }
+
+        return new Ipv4Cidr(network, netmask, size, bits);
+    }
+
+    private static int parse(String s) {
+        var i = Integer.parseInt(s);
+        if (i > 255) {
+            throw new IllegalArgumentException("Not a CIDR");
+        }
+
+        return i;
+    }
+}
diff --git a/src/main/java/io/trygvis/rules/engine/Main.java b/src/main/java/io/trygvis/rules/engine/Main.java
index 5556db7..6f04a98 100644
--- a/src/main/java/io/trygvis/rules/engine/Main.java
+++ b/src/main/java/io/trygvis/rules/engine/Main.java
@@ -3,6 +3,8 @@ package io.trygvis.rules.engine;
 import io.trygvis.rules.acme.AcmeIo;
 import io.trygvis.rules.dns.DnsEntry;
 import io.trygvis.rules.machine.Machine;
+import io.trygvis.rules.network.Ipv4Address;
+import io.trygvis.rules.network.Ipv4Cidr;
 import org.drools.core.audit.WorkingMemoryConsoleLogger;
 import org.kie.api.KieServices;
 import org.kie.api.event.rule.AgendaEventListener;
@@ -38,9 +40,12 @@ public class Main {
 
         io.dump("phase-1", session.getFactHandles());
 
-        io.dump("vpn0", session.getFactHandles(), (Object o) -> {
-            return o.getClass().getName().contains("Wg") || o instanceof Machine || o instanceof DnsEntry;
-        });
+        io.dump("vpn0", session.getFactHandles(), (Object o) ->
+                o.getClass().getName().contains("Wg") ||
+                o instanceof Machine ||
+                o instanceof DnsEntry ||
+                o instanceof Ipv4Cidr ||
+                o instanceof Ipv4Address);
 
         session.dispose();
     }
diff --git a/src/main/java/io/trygvis/rules/network/Ipv4Address.java b/src/main/java/io/trygvis/rules/network/Ipv4Address.java
new file mode 100644
index 0000000..071bca9
--- /dev/null
+++ b/src/main/java/io/trygvis/rules/network/Ipv4Address.java
@@ -0,0 +1,35 @@
+package io.trygvis.rules.network;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+import java.io.IOException;
+
+@JsonSerialize(using = Ipv4Address.Serializer.class)
+public class Ipv4Address {
+    public final int address;
+
+    public Ipv4Address(int address) {
+        this.address = address;
+    }
+
+    @Override
+    public String toString() {
+        return "%d.%d.%d.%d".formatted(
+                address >> 24 & 0xff,
+                address >> 16 & 0xff,
+                address >> 8 & 0xff,
+                address & 0xff);
+    }
+
+    public static class Serializer extends JsonSerializer<Ipv4Address> {
+        @Override
+        public void serialize(Ipv4Address value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
+            gen.writeStartObject();
+            gen.writeObjectField("value", value.toString());
+            gen.writeEndObject();
+        }
+    }
+}
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;
+    }
+}