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, 61 insertions, 0 deletions

diff --git a/app/src/main/java/com/wireguard/config/InetNetwork.java b/app/src/main/java/com/wireguard/config/InetNetwork.java
new file mode 100644
index 00000000..27825e6a
--- /dev/null
+++ b/app/src/main/java/com/wireguard/config/InetNetwork.java
@@ -0,0 +1,61 @@
+/*
+ * 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 java.net.Inet4Address;
+import java.net.InetAddress;
+import java.util.Objects;
+
+public class InetNetwork {
+    private final InetAddress address;
+    private final int mask;
+
+    public InetNetwork(@NonNull final String input) {
+        final int slash = input.lastIndexOf('/');
+        final int rawMask;
+        final String rawAddress;
+        if (slash >= 0) {
+            rawMask = Integer.parseInt(input.substring(slash + 1), 10);
+            rawAddress = input.substring(0, slash);
+        } else {
+            rawMask = -1;
+            rawAddress = input;
+        }
+        address = InetAddresses.parse(rawAddress);
+        final int maxMask = (address instanceof Inet4Address) ? 32 : 128;
+        mask = rawMask >= 0 && rawMask <= maxMask ? rawMask : maxMask;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (!(obj instanceof InetNetwork))
+            return false;
+        final InetNetwork other = (InetNetwork) obj;
+        return Objects.equals(address, other.address) && mask == other.mask;
+    }
+
+    @NonNull
+    public InetAddress getAddress() {
+        return address;
+    }
+
+    public int getMask() {
+        return mask;
+    }
+
+    @Override
+    public int hashCode() {
+        return address.hashCode() ^ mask;
+    }
+
+    @Override
+    public String toString() {
+        return address.getHostAddress() + '/' + mask;
+    }
+}