1 files changed, 24 insertions, 13 deletions

diff --git a/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java b/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
index 66855f11..abd888c8 100644
--- a/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
+++ b/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
@@ -6,6 +6,7 @@
 package com.wireguard.config;
 
 import com.wireguard.util.NonNullForAll;
+import com.wireguard.util.Resolver;
 
 import java.net.Inet4Address;
 import java.net.InetAddress;
@@ -87,24 +88,34 @@ public final class InetEndpoint {
      *
      * @return the resolved endpoint, or {@link Optional#empty()}
      */
-    public Optional<InetEndpoint> getResolved() {
-        if (isResolved)
+    public Optional<InetEndpoint> getResolved(Resolver resolver) {
+        return getResolved(resolver, false, false);
+    }
+
+    public Optional<InetEndpoint> getResolved(Resolver resolver, Boolean force) {
+        return getResolved(resolver, force, false);
+    }
+
+    public Optional<InetEndpoint> getResolvedIfChanged(Resolver resolver) {
+        return getResolved(resolver, true, true);
+    }
+
+    public Optional<InetEndpoint> getResolved(Resolver resolver, Boolean force, Boolean ifChanged) {
+        if (!force && isResolved)
             return Optional.of(this);
         synchronized (lock) {
             //TODO(zx2c4): Implement a real timeout mechanism using DNS TTL
-            if (Duration.between(lastResolution, Instant.now()).toMinutes() > 1) {
+            if (force || Duration.between(lastResolution, Instant.now()).toMinutes() > 1) {
                 try {
-                    // Prefer v4 endpoints over v6 to work around DNS64 and IPv6 NAT issues.
-                    final InetAddress[] candidates = InetAddress.getAllByName(host);
-                    InetAddress address = candidates[0];
-                    for (final InetAddress candidate : candidates) {
-                        if (candidate instanceof Inet4Address) {
-                            address = candidate;
-                            break;
-                        }
-                    }
-                    resolved = new InetEndpoint(address.getHostAddress(), true, port);
+                    InetAddress address = resolver.resolve(host);
+                    InetEndpoint resolvedNow = new InetEndpoint(address.getHostAddress(), true, port);
                     lastResolution = Instant.now();
+
+                    if (ifChanged && resolvedNow.equals(resolved)) {
+                        return Optional.empty();
+                    }
+
+                    resolved = resolvedNow;
                 } catch (final UnknownHostException e) {
                     resolved = null;
                 }