address in login page, update via

implements #194

build.gradle.kts

@@ -57,8 +57,8 @@ dependencies {
     implementation(kotlin("stdlib-jdk8"))
     implementation(kotlin("reflect"))
 
-    val vvVer = "4.2.2-SNAPSHOT"
+    val vvVer = "4.3.0-22w11a-SNAPSHOT"
-    val vbVer = "4.2.1-SNAPSHOT"
+    val vbVer = "4.3.0-22w11a-SNAPSHOT"
     val vrVer = "ae62eba"
     implementation("com.viaversion:viaversion:$vvVer") { isTransitive = false }
     implementation("com.viaversion:viabackwards:$vbVer") { isTransitive = false }
@@ -68,7 +68,7 @@ dependencies {
     implementation("io.netty:netty-tcnative-boringssl-static:2.0.50.Final")
     implementation("io.netty.incubator:netty-incubator-transport-native-io_uring:0.0.12.Final:linux-x86_64")
 
-    implementation("com.google.guava:guava:31.0.1-jre")
+    implementation("com.google.guava:guava:31.1-jre")
     implementation("com.velocitypowered:velocity-native:3.1.0")
     implementation("net.coobird:thumbnailator:0.4.17")
     implementation("org.powernukkit.fastutil:fastutil-lite:8.1.1")

src/main/java/com/viaversion/aas/handler/state/StatusKicked.java

@@ -41,4 +41,9 @@ public class StatusKicked implements ConnectionState {
 	public void onInactivated(@NotNull MinecraftHandler handler) {
 		ConnectionState.DefaultImpls.onInactivated(this, handler);
 	}
+
+	@Override
+	public void start(@NotNull MinecraftHandler handler) {
+		ConnectionState.DefaultImpls.start(this, handler);
+	}
 }

src/main/java/com/viaversion/aas/util/AddressParser.java

@@ -5,9 +5,7 @@ import com.google.common.primitives.Ints;
 import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
 import kotlin.text.StringsKt;
 
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Arrays;
-import java.util.List;
 import java.util.regex.Pattern;
 
 public class AddressParser {
@@ -19,11 +17,18 @@ public class AddressParser {
 	public String username;
 	public Boolean online;
 
-	public AddressParser parse(String address, String viaHostName) {
+	public AddressParser parse(String rawAddress, List<String> viaHostName) {
-		address = StringsKt.removeSuffix(address, ".");
+		String address = StringsKt.removeSuffix(rawAddress, ".");
-		String suffixRemoved = StringsKt.removeSuffix(address, "." + viaHostName);
 
-		if (suffixRemoved.equals(address)) {
+		String suffix = viaHostName.stream()
+				.filter(s -> StringsKt.endsWith("." + address, s, true))
+				.findAny()
+				.orElse(null);
+
+		String suffixRemoved;
+		if (suffix != null) {
+			suffixRemoved = StringsKt.removeSuffix(address, "." + suffix);
+		} else {
 			serverAddress = address;
 			return this;
 		}
@@ -43,7 +48,7 @@ public class AddressParser {
 
 		serverAddress = String.join(".", Lists.reverse(serverParts));
 		viaOptions = String.join(".", Lists.reverse(optionsParts));
-		viaSuffix = viaHostName;
+		viaSuffix = suffix;
 
 		return this;
 	}
@@ -61,7 +66,7 @@ public class AddressParser {
 		}
 
 		String arg = part.substring(2);
-		switch (option) {
+		switch (option.toLowerCase(Locale.ROOT)) {
 			case "o": {
 				parseOnlineMode(arg);
 				break;

src/main/kotlin/com/viaversion/aas/handler/state/ConnectionState.kt

@@ -32,4 +32,7 @@ interface ConnectionState {
         logDisconnect(handler, "-")
         handler.other?.close()
     }
+
+    fun start(handler: MinecraftHandler) {
+    }
 }

src/main/kotlin/com/viaversion/aas/handler/state/HandshakeState.kt

@@ -7,16 +7,12 @@ import com.google.common.util.concurrent.RateLimiter
 import com.viaversion.aas.codec.packet.Packet
 import com.viaversion.aas.codec.packet.handshake.Handshake
 import com.viaversion.aas.config.VIAaaSConfig
-import com.viaversion.aas.fireExceptionCaughtIfOpen
 import com.viaversion.aas.handler.MinecraftHandler
 import com.viaversion.aas.mcLogger
-import com.viaversion.aas.setAutoRead
 import com.viaversion.aas.util.AddressParser
 import com.viaversion.aas.util.StacklessException
 import com.viaversion.viaversion.api.protocol.packet.State
 import io.netty.channel.ChannelHandlerContext
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
 import java.net.InetAddress
 import java.net.InetSocketAddress
 import java.util.concurrent.TimeUnit
@@ -52,7 +48,7 @@ class HandshakeState : ConnectionState {
     private fun handleNextState(handler: MinecraftHandler, packet: Handshake) {
         handler.data.frontVer = packet.protocolId
         when (packet.nextState.ordinal) {
-            1 -> handler.data.state = StatusState
+            1 -> handler.data.state = StatusState()
             2 -> handler.data.state = LoginState()
             else -> throw StacklessException("Invalid next state")
         }
@@ -63,36 +59,42 @@ class HandshakeState : ConnectionState {
         val extraData = packet.address.substringAfter(0.toChar(), missingDelimiterValue = "").ifEmpty { null }
         val virtualHostNoExtra = packet.address.substringBefore(0.toChar())
 
-        val parsed = VIAaaSConfig.hostName.map {
+        val parsed = AddressParser().parse(virtualHostNoExtra, VIAaaSConfig.hostName)
-            AddressParser().parse(virtualHostNoExtra, it)
-        }.sortedBy {
-            it.viaSuffix == null
-        }.first()
 
         val backProto = parsed.protocol ?: -2
         val hadHostname = parsed.viaSuffix != null
 
-        packet.address = parsed.serverAddress!!
+        val backAddress = parsed.serverAddress!!
-        packet.port = parsed.port ?: VIAaaSConfig.defaultBackendPort ?: virtualPort
+        val port = parsed.port ?: VIAaaSConfig.defaultBackendPort ?: virtualPort
+        val host = HostAndPort.fromParts(backAddress, port)
 
         var frontOnline = parsed.online
-        if (VIAaaSConfig.forceOnlineMode) frontOnline = true
+
+        val addressFromWeb = VIAaaSConfig.hostName.any { parsed.serverAddress.equals(it, ignoreCase = true) }
 
         handler.data.backServerVer = backProto
         (handler.data.state as? LoginState)?.also {
             it.frontOnline = frontOnline
             it.backName = parsed.username
-            it.backAddress = HostAndPort.fromParts(packet.address, packet.port)
+            if (!addressFromWeb) {
+                it.backAddress = host
+            }
             it.extraData = extraData
         }
+        (handler.data.state as? StatusState)?.also {
+            if (!addressFromWeb) {
+                it.address = host
+            }
+        }
 
         val playerAddr = handler.data.frontHandler.endRemoteAddress
         mcLogger.debug(
-            "HS: $playerAddr ${handler.data.state.state.toString().substring(0, 1)} " +
+            "HS: $playerAddr ${handler.data.state.state.name[0]} " +
                     "$virtualHostNoExtra $virtualPort v${handler.data.frontVer}"
         )
 
-        if (!hadHostname && VIAaaSConfig.requireHostName) {
+        if (!hadHostname && VIAaaSConfig.requireHostName && !addressFromWeb
+        ) {
             throw StacklessException("Missing parts in hostname")
         }
     }
@@ -104,20 +106,7 @@ class HandshakeState : ConnectionState {
         checkRateLimit(handler, packet.nextState)
         handleVirtualHost(handler, packet)
 
-        connectStatus(handler, ctx, packet)
+        handler.data.state.start(handler)
-    }
-
-    private fun connectStatus(handler: MinecraftHandler, ctx: ChannelHandlerContext, packet: Handshake) {
-        if (packet.nextState == State.STATUS) { // see LoginState for LOGIN
-            handler.data.frontChannel.setAutoRead(false)
-            handler.coroutineScope.launch(Dispatchers.IO) {
-                try {
-                    connectBack(handler, packet.address, packet.port, packet.nextState)
-                } catch (e: Exception) {
-                    ctx.channel().fireExceptionCaughtIfOpen(e)
-                }
-            }
-        }
     }
 
     override fun disconnect(handler: MinecraftHandler, msg: String) {

src/main/kotlin/com/viaversion/aas/handler/state/LoginState.kt

@@ -32,7 +32,7 @@ class LoginState : ConnectionState {
     lateinit var frontServerId: String
     var frontOnline: Boolean? = null
     lateinit var frontName: String
-    lateinit var backAddress: HostAndPort
+    var backAddress: HostAndPort? = null
     lateinit var cryptoKey: KeyPair
     var extraData: String? = null
     var backName: String? = null
@@ -226,15 +226,24 @@ class LoginState : ConnectionState {
 
         handler.coroutineScope.launch(Dispatchers.IO) {
             try {
+                if (backAddress == null) {
+                    mcLogger.info("Requesting address info from web for $frontName")
+                    val info = AspirinServer.viaWebServer.requestAddressInfo(frontName).await()
+                    backAddress = info.backHostAndPort
+                    handler.data.backServerVer = info.backVersion
+                    frontOnline = info.frontOnline
+                }
+                if (VIAaaSConfig.forceOnlineMode) frontOnline = true
                 if (frontOnline != null) {
                     when (frontOnline) {
                         false -> callbackPlayerId.complete(generateOfflinePlayerUuid(frontName))
                         true -> authenticateOnlineFront(handler.data.frontChannel) // forced
+                        else -> {}
                     }
                     val id = callbackPlayerId.await()
                     mcLogger.info("Login: ${handler.endRemoteAddress} $frontName $id")
                 }
-                connectBack(handler, backAddress.host, backAddress.port, State.LOGIN, extraData)
+                connectBack(handler, HostAndPort.fromParts(backAddress!!.host, backAddress!!.port), State.LOGIN, extraData)
                 loginStart.username = backName!!
                 send(handler.data.backChannel!!, loginStart, true)
             } catch (e: Exception) {

src/main/kotlin/com/viaversion/aas/handler/state/StatusState.kt

@@ -1,25 +1,27 @@
 package com.viaversion.aas.handler.state
 
+import com.google.common.net.HostAndPort
 import com.google.gson.JsonArray
 import com.google.gson.JsonObject
 import com.google.gson.JsonParser
-import com.viaversion.aas.AspirinServer
+import com.viaversion.aas.*
 import com.viaversion.aas.codec.packet.Packet
 import com.viaversion.aas.codec.packet.UnknownPacket
 import com.viaversion.aas.codec.packet.status.StatusResponse
 import com.viaversion.aas.config.VIAaaSConfig
 import com.viaversion.aas.handler.MinecraftHandler
 import com.viaversion.aas.handler.forward
-import com.viaversion.aas.parseProtocol
-import com.viaversion.aas.send
 import com.viaversion.aas.util.StacklessException
 import com.viaversion.viaversion.api.protocol.packet.State
 import io.netty.channel.ChannelHandlerContext
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import java.util.*
 
-object StatusState : ConnectionState {
+class StatusState : ConnectionState {
     override val state: State
         get() = State.STATUS
+    var address: HostAndPort? = null
 
     override fun handlePacket(handler: MinecraftHandler, ctx: ChannelHandlerContext, packet: Packet) {
         if (packet is UnknownPacket) throw StacklessException("Invalid packet")
@@ -72,4 +74,19 @@ object StatusState : ConnectionState {
         send(handler.data.frontChannel, packet, flush = true)
         handler.data.state = StatusKicked()
     }
+
+    override fun start(handler: MinecraftHandler) {
+        handler.data.frontChannel.setAutoRead(false)
+        handler.coroutineScope.launch(Dispatchers.IO) {
+            try {
+                if (address != null) {
+                    connectBack(handler, address!!, state)
+                } else {
+                    handler.disconnect("VIAaaS")
+                }
+            } catch (e: Exception) {
+                handler.data.frontChannel.fireExceptionCaughtIfOpen(e)
+            }
+        }
+    }
 }

src/main/kotlin/com/viaversion/aas/handler/state/Util.kt

@@ -51,7 +51,7 @@ private suspend fun createBackChannel(
         .channel()
     (channel.pipeline()["proxy"] as? ProxyHandler)?.connectFuture()?.suspendAwait()
 
-    mcLogger.info("+ ${state.name.substring(0, 1)} ${handler.endRemoteAddress} -> $socketAddr")
+    mcLogger.info("+ ${state.name[0]} ${handler.endRemoteAddress} -> $socketAddr")
     handler.data.backChannel = channel as SocketChannel
 
     autoDetectVersion(handler, socketAddr)
@@ -143,12 +143,11 @@ private suspend fun resolveBackendAddresses(hostAndPort: HostAndPort): List<Inet
 
 suspend fun connectBack(
     handler: MinecraftHandler,
-    address: String,
+    address: HostAndPort,
-    port: Int,
     state: State,
     extraData: String? = null
 ) {
-    val addresses = resolveBackendAddresses(HostAndPort.fromParts(address, port))
+    val addresses = resolveBackendAddresses(address)
 
     if (addresses.isEmpty()) throw StacklessException("Hostname has no IP addresses")
 

src/main/kotlin/com/viaversion/aas/web/WebLogin.kt

@@ -1,9 +1,12 @@
 package com.viaversion.aas.web
 
+import com.google.common.net.HostAndPort
+import com.google.common.primitives.Ints
 import com.google.gson.JsonObject
 import com.google.gson.JsonParser
 import com.viaversion.aas.*
 import com.viaversion.aas.util.StacklessException
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion
 import io.ktor.client.call.*
 import io.ktor.client.request.forms.*
 import io.ktor.http.*
@@ -27,10 +30,11 @@ class WebLogin : WebState {
 
         when (obj.getAsJsonPrimitive("action").asString) {
             "offline_login" -> handleOfflineLogin(webClient, msg, obj)
-            "minecraft_id_login" -> handleMcIdLogin(webClient, msg, obj)
+            "minecraft_id_login" -> handleMcIdLogin(webClient, obj)
-            "listen_login_requests" -> handleListenLogins(webClient, msg, obj)
+            "listen_login_requests" -> handleListenLogins(webClient, obj)
-            "unlisten_login_requests" -> handleUnlisten(webClient, msg, obj)
+            "unlisten_login_requests" -> handleUnlisten(webClient, obj)
-            "session_hash_response" -> handleSessionResponse(webClient, msg, obj)
+            "session_hash_response" -> handleSessionResponse(webClient, obj)
+            "parameters_response" -> handleParametersResponse(webClient, obj)
             else -> throw StacklessException("invalid action!")
         }
 
@@ -77,7 +81,7 @@ class WebLogin : WebState {
         webLogger.info("Token gen: ${webClient.id}: offline $username $uuid")
     }
 
-    private suspend fun handleMcIdLogin(webClient: WebClient, msg: String, obj: JsonObject) {
+    private suspend fun handleMcIdLogin(webClient: WebClient, obj: JsonObject) {
         val username = obj["username"].asString
         val code = obj["code"].asString
 
@@ -102,7 +106,7 @@ class WebLogin : WebState {
         }
     }
 
-    private suspend fun handleListenLogins(webClient: WebClient, msg: String, obj: JsonObject) {
+    private suspend fun handleListenLogins(webClient: WebClient, obj: JsonObject) {
         val token = obj.getAsJsonPrimitive("token").asString
         val user = webClient.server.parseToken(token)
         val response = JsonObject().also {
@@ -121,7 +125,7 @@ class WebLogin : WebState {
         webClient.ws.send(response.toString())
     }
 
-    private suspend fun handleUnlisten(webClient: WebClient, msg: String, obj: JsonObject) {
+    private suspend fun handleUnlisten(webClient: WebClient, obj: JsonObject) {
         val uuid = UUID.fromString(obj.getAsJsonPrimitive("uuid").asString)
         webLogger.info("Unlisten: ${webClient.id}: $uuid")
         val response = JsonObject().also {
@@ -132,8 +136,26 @@ class WebLogin : WebState {
         webClient.ws.send(response.toString())
     }
 
-    private suspend fun handleSessionResponse(webClient: WebClient, msg: String, obj: JsonObject) {
+    private fun handleSessionResponse(webClient: WebClient, obj: JsonObject) {
         val hash = obj["session_hash"].asString
         webClient.server.sessionHashCallbacks.getIfPresent(hash)?.complete(Unit)
     }
+
+    private fun handleParametersResponse(webClient: WebClient, obj: JsonObject) {
+        val callback = UUID.fromString(obj["callback"].asString)
+        webClient.server.addressCallbacks[callback].complete(
+            WebServer.AddressInfo(
+                backVersion = obj["version"].asString.let {
+                    var protocol = Ints.tryParse(it)
+                    if (protocol == null) {
+                        val ver = ProtocolVersion.getClosest(it)
+                        if (ver != null) protocol = ver.version
+                    }
+                    protocol ?: -2
+                },
+                backHostAndPort = HostAndPort.fromParts(obj["host"].asString, obj["port"].asInt),
+                frontOnline = obj["frontOnline"].asString.toBooleanStrictOrNull()
+            )
+        )
+    }
 }

src/main/kotlin/com/viaversion/aas/web/WebServer.kt

@@ -7,13 +7,11 @@ import com.google.common.cache.CacheBuilder
 import com.google.common.cache.CacheLoader
 import com.google.common.collect.MultimapBuilder
 import com.google.common.collect.Multimaps
+import com.google.common.net.HostAndPort
 import com.google.gson.JsonObject
-import com.viaversion.aas.AspirinServer
+import com.viaversion.aas.*
 import com.viaversion.aas.config.VIAaaSConfig
-import com.viaversion.aas.parseUndashedId
-import com.viaversion.aas.reverseLookup
 import com.viaversion.aas.util.StacklessException
-import com.viaversion.aas.webLogger
 import io.ktor.client.call.*
 import io.ktor.client.request.*
 import io.ktor.server.netty.*
@@ -25,6 +23,7 @@ import io.netty.handler.codec.dns.DnsRecordType
 import io.netty.util.ReferenceCountUtil
 import kotlinx.coroutines.*
 import kotlinx.coroutines.future.asCompletableFuture
+import kotlinx.coroutines.future.await
 import java.net.InetSocketAddress
 import java.net.SocketAddress
 import java.time.Duration
@@ -78,14 +77,63 @@ class WebServer {
         .build<String, CompletableFuture<UUID?>>(CacheLoader.from { name ->
             CoroutineScope(Dispatchers.IO).async {
                 AspirinServer.httpClient
-                    .get("https://api.mojang.com/users/profiles/minecraft/$name").body<JsonObject?>()
+                    .get("https://api.mojang.com/users/profiles/minecraft/$name")
-                    ?.get("id")?.asString?.let { parseUndashedId(it) }
+                    .body<JsonObject?>()?.get("id")?.asString?.let { parseUndashedId(it) }
             }.asCompletableFuture()
         })
 
     val sessionHashCallbacks = CacheBuilder.newBuilder()
         .expireAfterWrite(30, TimeUnit.SECONDS)
         .build<String, CompletableFuture<Unit>>(CacheLoader.from { _ -> CompletableFuture() })
+    val addressCallbacks = CacheBuilder.newBuilder()
+        .expireAfterWrite(30, TimeUnit.SECONDS)
+        .build<UUID, CompletableFuture<AddressInfo>>(CacheLoader.from { _ -> CompletableFuture() })
+
+    data class AddressInfo(val backVersion: Int, val backHostAndPort: HostAndPort, var frontOnline: Boolean? = null)
+
+    suspend fun requestAddressInfo(frontName: String): CompletableFuture<AddressInfo> {
+        var onlineId: UUID? = null
+        try {
+            onlineId = usernameIdCache[frontName].await()
+        } catch (e: java.lang.Exception) {
+            webLogger.debug("Couldn't get online uuid for $frontName", e)
+        }
+        val offlineId = generateOfflinePlayerUuid(frontName)
+
+        val callbackId = UUID.randomUUID()
+        val future = addressCallbacks.get(callbackId)
+        CoroutineScope(coroutineContext).apply {
+            launch(Dispatchers.IO) {
+                run sending@{
+                    onlineId?.let {
+                        if (sendRequestAddress(it, callbackId)) return@sending
+                    }
+                    if (sendRequestAddress(offlineId, callbackId)) return@sending
+                    future.completeExceptionally(StacklessException("Username $frontName not listened. Use web auth to select backend server address."))
+                }
+            }
+            launch {
+                delay(20_000)
+                future.completeExceptionally(StacklessException("No response from browser"))
+            }
+        }
+        return future
+    }
+
+    private suspend fun sendRequestAddress(uuid: UUID, callbackId: UUID): Boolean {
+        var sent = false
+        listeners.get(uuid).forEach {
+            it.ws.send(
+                JsonObject().also {
+                    it.addProperty("action", "parameters_request")
+                    it.addProperty("callback", callbackId.toString())
+                }.toString()
+            )
+            it.ws.flush()
+            sent = true
+        }
+        return sent
+    }
 
     suspend fun requestSessionJoin(
         frontName: String,

src/main/resources/web/index.html

@@ -91,12 +91,32 @@ script-src 'self' https://*.cloudflare.com/ https://alcdn.msauth.net/ https://*.
         <p>WebSocket connection status: <span class="text-white bg-dark" id="connection_status">?</span></p>
         <p>CORS Proxy status: <span class="text-white bg-dark" id="cors_status">?</span></p>
         <hr>
-        <p>Listening to frontend logins from: <span id="listening"></span></p>
+        <p>Listening to frontend logins from:</p>
+        <div id="listening"></div>
         <div id="actions">
-            <button id="listen_continue" type="button" class="btn btn-primary">Listen to</button>
+            <button id="listen_continue" type="button" class="btn btn-primary">Listen to <span id="mcIdUsername"></span>
+            </button>
             <button id="listen_premium" type="button" class="btn btn-primary">Listen to premium login</button>
             <button id="listen_offline" type="button" class="btn btn-primary">Listen to offline mode login</button>
         </div>
+        <hr>
+        <p>Connecting to backend server:</p>
+        <div id="connect">
+            <form class="input-group">
+                <input id="connect_address" type="text" class="form-control" placeholder="Address">
+                <input id="connect_port" type="number" min="1" max="65535" class="form-control"
+                       placeholder="Port">
+                <input id="connect_version" type="text" class="form-control" placeholder="Version">
+                <select class="form-select" id="connect_online">
+                    <option value="null" selected>Front Online Mode...</option>
+                    <option>AUTO</option>
+                    <option value="true">Force online</option>
+                    <option value="false">Force offline (recommended for Geyser)</option>
+                </select>
+            </form>
+        </div>
+        <p>You can also use <a href="https://jo0001.github.io/ViaSetup/aspirin" id="viasetup_address">address
+            generator</a></p>
     </div>
 
     <div aria-labelledby="settings-tab" class="tab-pane fade" id="settings">

src/main/resources/web/js/page.js

@@ -1,6 +1,6 @@
 // Minecraft.id
 let urlParams = new URLSearchParams();
-window.location.hash.substr(1).split("?")
+window.location.hash.substring(1).split("?")
     .map(it => new URLSearchParams(it)
     .forEach((a, b) => urlParams.append(b, a)));
 let mcIdUsername = urlParams.get("username");
@@ -138,7 +138,8 @@ $("#listen_offline").on("click", () => {
     workers.forEach(it => it.postMessage({action: "listen_pow", user: user, id: taskId, deltaTime: deltaTime}));
     addToast("Offline username", "Please wait a minute...");
 });
-$("#listen_continue").append(document.createTextNode(" " + mcIdUsername)).on("click", () => {
+$("#mcIdUsername").text(mcIdUsername);
+$("#listen_continue").on("click", () => {
     sendSocket(JSON.stringify({
         "action": "minecraft_id_login",
         "username": mcIdUsername,
@@ -449,7 +450,7 @@ class MojangAccount extends McAccount {
             headers: {"content-type": "application/json"},
         })
             .then(r => {
-                if (r.status == 403) {
+                if (r.status === 403) {
                     this.logout();
                     throw "403, token expired?";
                 }
@@ -548,6 +549,13 @@ class MicrosoftAccount extends McAccount {
                     })
             );
     }
+
+    checkActive() {
+        return fetch(getCorsProxy() + "https://api.minecraftservices.com/entitlements/mcstore", {
+            method: "get",
+            headers: {"authorization": "Bearer " + this.accessToken}
+        }).then(data => data.ok);
+    }
 }
 
 function findAccountByMcName(name) {
@@ -727,9 +735,22 @@ function onSocketMsg(event) {
         }
     } else if (parsed.action === "session_hash_request") {
         handleJoinRequest(parsed);
+    } else if (parsed.action === "parameters_request") {
+        handleParametersRequest(parsed);
     }
 }
 
+function handleParametersRequest(parsed) {
+    socket.send(JSON.stringify({
+        action: "parameters_response",
+        callback: parsed["callback"],
+        version: $("#connect_version").val(),
+        host: $("#connect_address").val(),
+        port: parseInt($("#connect_port").val()) || 25565,
+        frontOnline: $("#connect_online").val()
+    }));
+}
+
 function listenStoredTokens() {
     getTokens().forEach(listen);
 }

src/main/resources/web/sw.js

@@ -17,7 +17,7 @@ self.addEventListener("fetch", evt => {
     if (!shouldCache(evt.request.url)
         || evt.request.method !== "GET") return;
     evt.respondWith(
-        fromCache(evt.request).catch(() => fromNetwork(evt.request))
+        fromNetwork(evt.request).catch(() => fromCache(evt.request))
     );
 });