smarter packet-in string handling

Author: mcmonkey4eva

src/main/java/com/denizenscript/depenizen/bungee/DepenizenConnection.java

@@ -35,7 +35,13 @@ public void build(Channel channel, InetAddress address) {
         isValid = true;
     }
 
+    public boolean hasFailed = false;
+
     public void fail(String reason) {
+        if (hasFailed) {
+            return;
+        }
+        hasFailed = true;
         DepenizenBungee.instance.getLogger().info("Connection '" + connectionName + (thisServer == null ? "" : (" / " + thisServer.getName())) + "' failed: " + reason);
         channel.close();
     }

src/main/java/com/denizenscript/depenizen/bungee/PacketIn.java

@@ -9,9 +9,18 @@ public abstract class PacketIn {
 
     public abstract void process(DepenizenConnection connection, ByteBuf data);
 
-    public String readString(ByteBuf buf, int length) {
-        byte[] strBytes = new byte[length];
-        buf.readBytes(strBytes, 0, length);
+    public String readString(DepenizenConnection connection, ByteBuf buf, String label) {
+        if (buf.readableBytes() < 4) {
+            connection.fail("Invalid " + getName() + " Packet " + label + " length bytes (needed 4)");
+            return null;
+        }
+        int len = buf.readInt();
+        if (buf.readableBytes() < len || len < 0) {
+            connection.fail("Invalid " + getName() + " Packet " + label + " (bytes requested: " + len + ", bytes available: " + buf.readableBytes() + ")");
+            return null;
+        }
+        byte[] strBytes = new byte[len];
+        buf.readBytes(strBytes, 0, len);
         return new String(strBytes, Charsets.UTF_8);
     }
 }

src/main/java/com/denizenscript/depenizen/bungee/packets/in/ExecuteCommandPacketIn.java

@@ -14,16 +14,10 @@ public String getName() {
 
     @Override
     public void process(DepenizenConnection connection, ByteBuf data) {
-        if (data.readableBytes() < 4) {
-            connection.fail("Invalid ExecuteCommandPacket (bytes available: " + data.readableBytes() + ")");
+        String command = readString(connection, data, "command");
+        if (command == null) {
             return;
         }
-        int commandLength = data.readInt();
-        if (data.readableBytes() < commandLength || commandLength < 0) {
-            connection.fail("Invalid ExecuteCommandPacket (version bytes requested: " + commandLength + ")");
-            return;
-        }
-        String command = readString(data, commandLength);
         ProxyServer.getInstance().getPluginManager().dispatchCommand(ProxyServer.getInstance().getConsole(), command);
     }
 }

src/main/java/com/denizenscript/depenizen/bungee/packets/in/ProxyCommandResultPacketIn.java

@@ -21,12 +21,10 @@ public void process(DepenizenConnection connection, ByteBuf data) {
             return;
         }
         long id = data.readLong();
-        int resultLength = data.readInt();
-        if (data.readableBytes() < resultLength || resultLength < 0) {
-            connection.fail("Invalid ProxyCommandResultPacket (result bytes requested: " + resultLength + ")");
+        String result = readString(connection, data, "result");
+        if (result == null) {
             return;
         }
-        String result = readString(data, resultLength);
         CompletableFuture<String> future = DepenizenBungee.instance.proxyCommandWaiters.get(id);
         if (future == null) {
             return;

src/main/java/com/denizenscript/depenizen/bungee/packets/in/ProxyPingResultPacketIn.java

@@ -26,31 +26,22 @@ public void process(DepenizenConnection connection, ByteBuf data) {
         }
         long id = data.readLong();
         int maxPlayers = data.readInt();
-        int versionLength = data.readInt();
-        if (data.readableBytes() < versionLength || versionLength < 0) {
-            connection.fail("Invalid ProxyPingResultPacket (version bytes requested: " + versionLength + ")");
+        String version = readString(connection, data, "version");
+        String motd = readString(connection, data, "motd");
+        if (version == null || motd == null) {
             return;
         }
-        String version = readString(data, versionLength);
-        int motdLength = data.readInt();
-        if (data.readableBytes() < motdLength || motdLength < 0) {
-            connection.fail("Invalid ProxyPingResultPacket (motd bytes requested: " + motdLength + ")");
-            return;
-        }
-        String motd = readString(data, motdLength);
         int playerListCount = data.readInt();
         if (playerListCount < -1 || playerListCount > 1024) {
             connection.fail("Invalid ProxyPingResultPacket (playerListCount requested: " + playerListCount + ")");
             return;
         }
         ServerPing.PlayerInfo[] playerInfo = playerListCount == -1 ? null : new ServerPing.PlayerInfo[playerListCount];
         for (int i = 0; i < playerListCount; i++) {
-            int nameLength = data.readInt();
-            if (data.readableBytes() < nameLength || nameLength < 0) {
-                connection.fail("Invalid ProxyPingResultPacket (player " + i + "name bytes requested: " + nameLength + ")");
+            String name = readString(connection, data, "name");
+            if (name == null) {
                 return;
             }
-            String name = readString(data, nameLength);
             long idMost = data.readLong();
             long idLeast = data.readLong();
             UUID uuid = new UUID(idMost, idLeast);

src/main/java/com/denizenscript/depenizen/bungee/packets/in/RedirectPacketIn.java

@@ -19,12 +19,10 @@ public void process(DepenizenConnection connection, ByteBuf data) {
             connection.fail("Invalid RedirectPacket (bytes available: " + data.readableBytes() + ")");
             return;
         }
-        int targetServerNameLength = data.readInt();
-        if (data.readableBytes() < targetServerNameLength || targetServerNameLength < 0) {
-            connection.fail("Invalid RedirectPacket (name bytes requested: " + targetServerNameLength + ")");
+        String serverName = readString(connection, data, "serverName");
+        if (serverName == null) {
             return;
         }
-        String serverName = readString(data, targetServerNameLength);
         int newPacketLen = data.readInt();
         if (data.readableBytes() < newPacketLen || newPacketLen < 0) {
             connection.fail("Invalid RedirectPacket (packet bytes requested: " + newPacketLen + ")");