Add Backend to Monorepo

2024-08-18 11:15:54 +02:00
parent b8e50dc139
commit fd7fe8c305
37 changed files with 2703 additions and 26 deletions
@@ -0,0 +1,137 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2024 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.util
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.Transient
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonElement
+import java.io.*
+import java.net.InetSocketAddress
+import java.net.Socket
+
+/**
+ *
+ * @author zh32 <zh32 at zh32.de>
+</zh32> */
+private fun readVarInt(`in`: DataInputStream): Int {
+    var i = 0
+    var j = 0
+    while (true) {
+        val k = `in`.readByte().toInt()
+        i = i or (k and 0x7F shl j++ * 7)
+        if (j > 5) throw RuntimeException("VarInt too big")
+        if (k and 0x80 != 128) break
+    }
+    return i
+}
+
+private fun writeVarInt(out: DataOutputStream, paramInt: Int) {
+    var paramInts = paramInt
+    while (true) {
+        if (paramInts and -0x80 == 0) {
+            out.writeByte(paramInts)
+            return
+        }
+        out.writeByte(paramInts and 0x7F or 0x80)
+        paramInts = paramInts ushr 7
+    }
+}
+
+private val JSON = Json {
+    ignoreUnknownKeys = true
+}
+
+fun fetchData(address: InetSocketAddress, timeout: Int = 7000): StatusResponse {
+    val socket = Socket()
+    socket.setSoTimeout(timeout)
+    socket.connect(address, timeout)
+    val outputStream = socket.getOutputStream()
+    val dataOutputStream = DataOutputStream(outputStream)
+    val inputStream = socket.getInputStream()
+    val inputStreamReader = InputStreamReader(inputStream)
+    val b = ByteArrayOutputStream()
+    val handshake = DataOutputStream(b)
+    handshake.writeByte(0x00) //packet id for handshake
+    writeVarInt(handshake, 4) //protocol version
+    writeVarInt(handshake, address.hostString.length) //host length
+    handshake.writeBytes(address.hostString) //host string
+    handshake.writeShort(address.port) //port
+    writeVarInt(handshake, 1) //state (1 for handshake)
+    writeVarInt(dataOutputStream, b.size()) //prepend size
+    dataOutputStream.write(b.toByteArray()) //write handshake packet
+    dataOutputStream.writeByte(0x01) //size is only 1
+    dataOutputStream.writeByte(0x00) //packet id for ping
+    val dataInputStream = DataInputStream(inputStream)
+    readVarInt(dataInputStream) //size of packet
+    var id = readVarInt(dataInputStream) //packet id
+    if (id == -1) {
+        throw IOException("Premature end of stream.")
+    }
+    if (id != 0x00) { //we want a status response
+        throw IOException("Invalid packetID")
+    }
+    val length = readVarInt(dataInputStream) //length of json string
+    if (length == -1) {
+        throw IOException("Premature end of stream.")
+    }
+    if (length == 0) {
+        throw IOException("Invalid string length.")
+    }
+    val `in` = ByteArray(length)
+    dataInputStream.readFully(`in`) //read json string
+    val json = String(`in`)
+    val now = System.currentTimeMillis()
+    dataOutputStream.writeByte(0x09) //size of packet
+    dataOutputStream.writeByte(0x01) //0x01 for ping
+    dataOutputStream.writeLong(now) //time!?
+    readVarInt(dataInputStream)
+    id = readVarInt(dataInputStream)
+    if (id == -1) {
+        throw IOException("Premature end of stream.")
+    }
+    if (id != 0x01) {
+        throw IOException("Invalid packetID")
+    }
+    val pingtime = dataInputStream.readLong() //read response
+    val response: StatusResponse = JSON.decodeFromString(json)
+    response.time = (now - pingtime).toInt()
+    dataOutputStream.close()
+    outputStream.close()
+    inputStreamReader.close()
+    inputStream.close()
+    socket.close()
+    return response
+}
+
+@Serializable
+data class StatusResponse(val description: JsonElement, val players: Players, val version: Version, val favicon: String) {
+    @Transient
+    var time = 0
+}
+
+@Serializable
+data class Players(val max: Int, val online: Int, val sample: List<Player> = emptyList())
+
+@Serializable
+data class Player(val name: String, val id: String)
+
+@Serializable
+data class Version(val name: String, val protocol: Int)