From 8bcde9075a64efa7816f543dda7a82252b0f8a8d Mon Sep 17 00:00:00 2001
From: Aditya Agarwal <aditya.agarwal@groww.in>
Date: Mon, 10 Feb 2025 15:14:12 +0530
Subject: [PATCH 1/2] Ignore Ipv6

---
 .../io/nats/client/impl/SocketDataPort.java   | 45 ++++++++++++++++---
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/src/main/java/io/nats/client/impl/SocketDataPort.java b/src/main/java/io/nats/client/impl/SocketDataPort.java
index f3f546665..cb2807feb 100644
--- a/src/main/java/io/nats/client/impl/SocketDataPort.java
+++ b/src/main/java/io/nats/client/impl/SocketDataPort.java
@@ -23,12 +23,14 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.net.InetSocketAddress;
-import java.net.Socket;
-import java.net.SocketException;
-import java.net.URISyntaxException;
+import java.net.*;
 import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 
 import static io.nats.client.support.NatsConstants.SECURE_WEBSOCKET_PROTOCOL;
@@ -81,7 +83,7 @@ public void connect(NatsConnection conn, NatsUri nuri, long timeoutNanos) throws
             socket.setTcpNoDelay(true);
             socket.setReceiveBufferSize(2 * 1024 * 1024);
             socket.setSendBufferSize(2 * 1024 * 1024);
-            socket.connect(new InetSocketAddress(host, port), (int) timeout);
+            socket.connect(new InetSocketAddress(resolveHostToIps(nuri).get(0).getHost(), port), (int) timeout);
             if (soLinger > -1) {
                 socket.setSoLinger(true, soLinger);
             }
@@ -113,6 +115,39 @@ public void connect(NatsConnection conn, NatsUri nuri, long timeoutNanos) throws
         }
     }
 
+    private List<NatsUri> resolveHostToIps(NatsUri nuri) {
+        if (nuri.hostIsIpAddress()) {
+            return Arrays.asList(nuri);
+        }
+        try {
+            InetAddress[] addresses = InetAddress.getAllByName(nuri.getHost());
+            return rehostToNUri(Arrays.asList(addresses), nuri);
+        } catch (UnknownHostException e) {
+            System.out.println(String.format("[WARN] Ignoring Address %s as Error in resolving host: %s", nuri.getHost(), e.getMessage()));
+        }
+        return Arrays.asList(nuri);
+    }
+
+
+    private List<NatsUri> rehostToNUri(List<InetAddress> inetAddresses, NatsUri nuri) {
+        List<NatsUri> natsUris = new ArrayList<>();
+        for (InetAddress addr : inetAddresses) {
+            try {
+                if (addr instanceof Inet6Address) {
+                    continue;
+                }
+                natsUris.add(nuri.reHost(addr.getHostAddress()));
+            } catch (URISyntaxException e) {
+                System.out.println(String.format("[WARN] Ignoring Address %s as Error in while rehostToNri: %s", nuri.getHost(), e.getMessage()));
+            }
+        }
+        if (natsUris.size() < 1) {
+            natsUris.add(nuri);
+        }
+        Collections.shuffle(natsUris, ThreadLocalRandom.current());
+        return natsUris;
+    }
+
     /**
      * Upgrade the port to SSL. If it is already secured, this is a no-op.
      * If the data port type doesn't support SSL it should throw an exception.

From 8d9a245ec1ddd2bd9eecfa1e30866a248fe96717 Mon Sep 17 00:00:00 2001
From: Aditya Agarwal <aditya.agarwal@groww.in>
Date: Wed, 12 Feb 2025 11:34:40 +0530
Subject: [PATCH 2/2] Renamed Vars

---
 src/main/java/io/nats/client/impl/SocketDataPort.java | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/java/io/nats/client/impl/SocketDataPort.java b/src/main/java/io/nats/client/impl/SocketDataPort.java
index cb2807feb..cd6ac2fc3 100644
--- a/src/main/java/io/nats/client/impl/SocketDataPort.java
+++ b/src/main/java/io/nats/client/impl/SocketDataPort.java
@@ -83,7 +83,7 @@ public void connect(NatsConnection conn, NatsUri nuri, long timeoutNanos) throws
             socket.setTcpNoDelay(true);
             socket.setReceiveBufferSize(2 * 1024 * 1024);
             socket.setSendBufferSize(2 * 1024 * 1024);
-            socket.connect(new InetSocketAddress(resolveHostToIps(nuri).get(0).getHost(), port), (int) timeout);
+            socket.connect(new InetSocketAddress(getIpV4Addresses(nuri).get(0).getHost(), port), (int) timeout);
             if (soLinger > -1) {
                 socket.setSoLinger(true, soLinger);
             }
@@ -115,13 +115,13 @@ public void connect(NatsConnection conn, NatsUri nuri, long timeoutNanos) throws
         }
     }
 
-    private List<NatsUri> resolveHostToIps(NatsUri nuri) {
+    private List<NatsUri> getIpV4Addresses(NatsUri nuri) {
         if (nuri.hostIsIpAddress()) {
             return Arrays.asList(nuri);
         }
         try {
             InetAddress[] addresses = InetAddress.getAllByName(nuri.getHost());
-            return rehostToNUri(Arrays.asList(addresses), nuri);
+            return filterIpv6Address(Arrays.asList(addresses), nuri);
         } catch (UnknownHostException e) {
             System.out.println(String.format("[WARN] Ignoring Address %s as Error in resolving host: %s", nuri.getHost(), e.getMessage()));
         }
@@ -129,7 +129,7 @@ private List<NatsUri> resolveHostToIps(NatsUri nuri) {
     }
 
 
-    private List<NatsUri> rehostToNUri(List<InetAddress> inetAddresses, NatsUri nuri) {
+    private List<NatsUri> filterIpv6Address(List<InetAddress> inetAddresses, NatsUri nuri) {
         List<NatsUri> natsUris = new ArrayList<>();
         for (InetAddress addr : inetAddresses) {
             try {