From 063bb512eb620d23fc41913e95e6405a43dbf699 Mon Sep 17 00:00:00 2001
From: William Blake Galbreath <Blake.Galbreath@GMail.com>
Date: Wed, 22 Jan 2020 20:13:40 -0600
Subject: [PATCH] UPnP Port Forwarding Service

---
 pom.xml                                       | 10 ++++++++
 .../net/minecraft/server/DedicatedServer.java | 25 +++++++++++++++++++
 .../net/minecraft/server/MinecraftServer.java | 11 ++++++++
 .../java/net/pl3x/purpur/PurpurConfig.java    |  5 ++++
 4 files changed, 51 insertions(+)

diff --git a/pom.xml b/pom.xml
index 37ff489db..c886104c5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -94,6 +94,12 @@
             <version>1.1.1</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>com.dosse.upnp</groupId>
+            <artifactId>UPnP</artifactId>
+            <version>1.0</version>
+            <scope>compile</scope>
+        </dependency>
         <dependency>
             <groupId>org.xerial</groupId>
             <artifactId>sqlite-jdbc</artifactId>
@@ -132,6 +138,10 @@
             <id>spigotmc-public</id>
             <url>https://hub.spigotmc.org/nexus/content/groups/public/</url>
         </repository>
+        <repository>
+            <id>pl3x</id>
+            <url>https://repo.pl3x.net/</url>
+        </repository>
     </repositories>
 
     <pluginRepositories>
diff --git a/src/main/java/net/minecraft/server/DedicatedServer.java b/src/main/java/net/minecraft/server/DedicatedServer.java
index 8b5f4cab0..3e31b2bb3 100644
--- a/src/main/java/net/minecraft/server/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/DedicatedServer.java
@@ -231,6 +231,31 @@ public class DedicatedServer extends MinecraftServer implements IMinecraftServer
             return false;
         }
 
+        // Purpur start
+        if (net.pl3x.purpur.PurpurConfig.useUPnP) {
+            LOGGER.info("[UPnP] Attempting to start UPnP port forwarding service...");
+            com.dosse.upnp.UPnP.NAME = "Purpur UPnP";
+            if (com.dosse.upnp.UPnP.isUPnPAvailable()) {
+                if (com.dosse.upnp.UPnP.isMappedTCP(getPort())) {
+                    upnp = false;
+                    LOGGER.info("[UPnP] Port " + getPort() + " is already open");
+                } else if (com.dosse.upnp.UPnP.openPortTCP(getPort())) {
+                    upnp = true;
+                    LOGGER.info("[UPnP] Successfully opened port " + getPort());
+                } else {
+                    upnp = false;
+                    LOGGER.info("[UPnP] Failed to open port " + getPort());
+                }
+                if (upnp) {
+                    LOGGER.info("[UPnP] " + com.dosse.upnp.UPnP.getExternalIP() + ":" + getPort());
+                }
+            } else {
+                upnp = false;
+                LOGGER.error("[UPnP] Service is unavailable");
+            }
+        }
+        // Purpur end
+
         // CraftBukkit start
         // this.a((PlayerList) (new DedicatedPlayerList(this))); // Spigot - moved up
         server.loadPlugins();
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 9d5ef40a0..01b5a6b3e 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -181,6 +181,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
     public boolean lagging = false; // Purpur
     public final SlackActivityAccountant slackActivityAccountant = new SlackActivityAccountant();
     // Spigot end
+    protected boolean upnp = false;
 
     public MinecraftServer(OptionSet options, Proxy proxy, DataFixer datafixer, CommandDispatcher commanddispatcher, YggdrasilAuthenticationService yggdrasilauthenticationservice, MinecraftSessionService minecraftsessionservice, GameProfileRepository gameprofilerepository, UserCache usercache, WorldLoadListenerFactory worldloadlistenerfactory, String s) {
         super("Server");
@@ -791,6 +792,16 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
         }
         // Spigot end
         com.destroystokyo.paper.io.PaperFileIOThread.Holder.INSTANCE.close(true, true); // Paper
+
+        // Purpur start
+        if (upnp) {
+            if (com.dosse.upnp.UPnP.closePortTCP(getPort())) {
+                LOGGER.info("[UPnP] Port " + getPort() + " closed");
+            } else {
+                LOGGER.error("[UPnP] Failed to close port " + getPort());
+            }
+        }
+        // Purpur end
     }
 
     public String getServerIp() {
diff --git a/src/main/java/net/pl3x/purpur/PurpurConfig.java b/src/main/java/net/pl3x/purpur/PurpurConfig.java
index 544c68b0d..917f6503d 100644
--- a/src/main/java/net/pl3x/purpur/PurpurConfig.java
+++ b/src/main/java/net/pl3x/purpur/PurpurConfig.java
@@ -137,6 +137,11 @@ public class PurpurConfig {
         return config.getString(path, config.getString(path));
     }
 
+    public static boolean useUPnP = false;
+    private static void upnpSettings() {
+        useUPnP = getBoolean("settings.upnp-port-forwarding", useUPnP);
+    }
+
     public static double laggingThreshold = 19.0D;
     private static void tickLoopSettings() {
         laggingThreshold = getDouble("settings.lagging-threshold", laggingThreshold);
-- 
2.24.0