config: Refactor IPCidr and use of InetAddress

Use a canonically-named utility class to tack on methods to the existing
InetAddress class. Rename IPCidr to InetNetwork so it better matches
InetAddress and is more pronouceable :) While here, simplify the
constructor and toString() functions, and properly implement hashCode().

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/app/src/main/java/com/wireguard/config/InetAddresses.java b/app/src/main/java/com/wireguard/config/InetAddresses.java
new file mode 100644
index 00000000..d351d53c
--- /dev/null
+++ b/app/src/main/java/com/wireguard/config/InetAddresses.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright © 2018 Samuel Holland <samuel@sholland.org>
+ * Copyright © 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+package com.wireguard.config;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.InetAddress;
+
+public final class InetAddresses {
+    private static final Method PARSER_METHOD;
+
+    static {
+        try {
+            // This method is only present on Android.
+            PARSER_METHOD = InetAddress.class.getMethod("parseNumericAddress", String.class);
+        } catch (final NoSuchMethodException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private InetAddresses() {
+        // Prevent instantiation.
+    }
+
+    @NonNull
+    public static InetAddress parse(@Nullable final String address) {
+        if (address == null || address.isEmpty())
+            throw new IllegalArgumentException("Empty address");
+        try {
+            return (InetAddress) PARSER_METHOD.invoke(null, address);
+        } catch (final IllegalAccessException | InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}