clearer message of domain suffix, add parsing options like "u__jeb"

src/main/kotlin/com/github/creeper123123321/viaaas/VIAaaSAddress.kt

@@ -1,6 +1,7 @@
 package com.github.creeper123123321.viaaas
 
 import us.myles.ViaVersion.api.protocol.ProtocolVersion
+import java.util.*
 
 class VIAaaSAddress {
     var serverAddress: String? = null
@@ -38,30 +39,23 @@ class VIAaaSAddress {
     }
 
     fun parseOption(part: String): Boolean {
-        if (part.startsWith("_")) {
+        val option = when {
+                part.length < 2 -> null
+                part.startsWith("_") -> part[1]
+                part[1] == '_' -> part[0]
+                else -> null
+            }?.toString()
+        if (option != null) {
             val arg = part.substring(2)
-            when {
-                part.startsWith("_p", ignoreCase = true) -> port = arg.toInt()
-                part.startsWith("_o", ignoreCase = true) -> {
-                    online = when {
+            when (option.toLowerCase(Locale.ROOT)) {
+                "p" -> port = arg.toInt()
+                "o" -> online = when {
                         arg.startsWith("t", ignoreCase = true) -> true
                         arg.startsWith("f", ignoreCase = true) -> false
                         else -> null
                     }
-                }
-                part.startsWith("_v", ignoreCase = true) -> {
-                    try {
-                        protocol = arg.toInt()
-                    } catch (e: NumberFormatException) {
-                        ProtocolVersion.getClosest(arg.replace("_", "."))?.also {
-                            protocol = it.version
-                        }
-                    }
-                    if (protocol == -2) {
-                        protocol = null
-                    }
-                }
-                part.startsWith("_u", ignoreCase = true) -> {
+                "v" -> parseProtocol(arg)
+                "u" -> {
                     if (arg.length > 16) throw IllegalArgumentException("Invalid username")
                     username = arg
                 }
@@ -70,4 +64,17 @@ class VIAaaSAddress {
         }
         return false
     }
+
+    private fun parseProtocol(arg: String) {
+        try {
+            protocol = arg.toInt()
+        } catch (e: NumberFormatException) {
+            ProtocolVersion.getClosest(arg.replace("_", "."))?.also {
+                protocol = it.version
+            }
+        }
+        if (protocol == -2) {
+            protocol = null
+        }
+    }
 }

src/main/kotlin/com/github/creeper123123321/viaaas/handler/state/HandshakeState.kt

@@ -70,7 +70,7 @@ class HandshakeState : MinecraftConnectionState {
         )
 
         if (!hadHostname && VIAaaSConfig.requireHostName) {
-            throw UnsupportedOperationException("This VIAaaS instance requires you to use the hostname")
+            throw UnsupportedOperationException("Missing domain suffix in hostname")
         }
 
         if (packet.nextState == State.STATUS) {
@@ -85,4 +85,4 @@ class HandshakeState : MinecraftConnectionState {
     override fun onInactivated(handler: MinecraftHandler) {
         // Not worth logging
     }
-}
+}

src/main/resources/viaaas.yml

@@ -16,7 +16,7 @@ mc-rsa-size: 4096
 use-strong-random: true
 # Blocks connection to local addresses
 block-local-address: true
-# Requires virtual host to contain the value from "host-name"
+# Requires virtual host to contain the value from "host-name" as a suffix
 # A false value could be used for transparent proxying.
 require-host-name: true
 # Default port to be used to connect to backend server
@@ -37,4 +37,4 @@ rate-limit-ws: 1.5
 # Rate limits new front-end connections per second per ip. Will disconnect when hit
 rate-limit-connection-mc: 10.0
 # Limits how many usernames a websocket connection can listen to.
-listening-ws-limit: 10
+listening-ws-limit: 10