From b98e525016648e5c5760d09bdec7c187ae090425 Mon Sep 17 00:00:00 2001
From: Steveice10 <Steveice10@gmail.com>
Date: Tue, 21 Apr 2020 12:01:26 -0700
Subject: [PATCH] Change SRV lookup code to use dnsjava.

---
 pom.xml                                       | 11 +++++++++
 .../packetlib/tcp/TcpClientSession.java       | 24 +++++++++----------
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/pom.xml b/pom.xml
index a9168ef1..ba13d261 100644
--- a/pom.xml
+++ b/pom.xml
@@ -52,6 +52,17 @@
             <version>4.1.45.Final</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>dnsjava</groupId>
+            <artifactId>dnsjava</artifactId>
+            <version>3.0.2</version>
+        </dependency>
+        <!-- Silence dnsjava slf4j warnings -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-nop</artifactId>
+            <version>1.7.30</version>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/main/java/com/github/steveice10/packetlib/tcp/TcpClientSession.java b/src/main/java/com/github/steveice10/packetlib/tcp/TcpClientSession.java
index fdbe422d..7f993781 100644
--- a/src/main/java/com/github/steveice10/packetlib/tcp/TcpClientSession.java
+++ b/src/main/java/com/github/steveice10/packetlib/tcp/TcpClientSession.java
@@ -15,10 +15,11 @@ import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.proxy.HttpProxyHandler;
 import io.netty.handler.proxy.Socks4ProxyHandler;
 import io.netty.handler.proxy.Socks5ProxyHandler;
-import io.netty.util.concurrent.Future;
-
-import javax.naming.directory.InitialDirContext;
-import java.util.Hashtable;
+import org.xbill.DNS.Lookup;
+import org.xbill.DNS.Record;
+import org.xbill.DNS.SRVRecord;
+import org.xbill.DNS.TextParseException;
+import org.xbill.DNS.Type;
 
 public class TcpClientSession extends TcpSession {
     private Client client;
@@ -104,17 +105,14 @@ public class TcpClientSession extends TcpSession {
                         int port = getPort();
 
                         try {
-                            Hashtable<String, String> environment = new Hashtable<String, String>();
-                            environment.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
-                            environment.put("java.naming.provider.url", "dns:");
+                            Record[] records = new Lookup(getPacketProtocol().getSRVRecordPrefix() + "._tcp." + host, Type.SRV).run();
+                            if(records.length > 0) {
+                                SRVRecord srv = (SRVRecord) records[0];
 
-                            String[] result = new InitialDirContext(environment).getAttributes(getPacketProtocol().getSRVRecordPrefix() + "._tcp." + host, new String[] {"SRV"}).get("srv").get().toString().split(" ", 4);
-                            host = result[3];
-                            port = Integer.parseInt(result[2]);
-                            if(host.endsWith(".")) {
-                                host = host.substring(0, host.length() - 1);
+                                host = srv.getTarget().toString().replaceFirst("\\.$", "");
+                                port = srv.getPort();
                             }
-                        } catch(Throwable t) {
+                        } catch(TextParseException e) {
                         }
 
                         bootstrap.remoteAddress(host, port);