A

.gitignore

@@ -35,4 +35,7 @@ build/
 .vscode/
 
 ### Mac OS ###
-.DS_Store
+.DS_Store
+
+# autopeerer
+/config/

config/nodes/node1.properties

@@ -0,0 +1,3 @@
+key=AAAAAAAAAAA=
+name="Node Number One"
+host=example.com

src/main/java/eu/m724/autopeerer/client/MyWebsocketClient.java

@@ -1,5 +1,7 @@
 package eu.m724.autopeerer.client;
 
+import eu.m724.autopeerer.common.packet.Packets;
+import eu.m724.autopeerer.common.packet.client.LoginPacket;
 import org.java_websocket.client.WebSocketClient;
 import org.java_websocket.handshake.ServerHandshake;
 
@@ -26,6 +28,8 @@ public class MyWebsocketClient extends WebSocketClient {
     public void onOpen(ServerHandshake serverHandshake) {
         double connectTime = (System.nanoTime() - connectStart) / 1000000.0;
         System.out.printf("Connected in %.3f ms\n", connectTime);
+
+        Packets.send(new LoginPacket(new byte[8]), this::send);
     }
 
     @Override

src/main/java/eu/m724/autopeerer/client/PacketHandler.java

@@ -55,16 +55,14 @@ public class PacketHandler {
             var status = PingResponsePacket.PingResponseStatus.ERROR;
 
             try {
-                Process process = Runtime.getRuntime().exec(new String[] { "ping", "-3Ac", "10", packet.target.getHostAddress() });
+                Process process = Runtime.getRuntime().exec(new String[] { "ping", "-3Ac", "10", "-W", "1", packet.target.getHostAddress() });
 
                 try (BufferedReader reader = process.inputReader()) {
                     for (String l : reader.lines().toList()) {
-                        boolean error = l.startsWith("From"); // indicates an error
                         boolean end = l.startsWith("rtt");
 
-                        if (error) {
+                        if (l.startsWith("PING")) {
                             status = PingResponsePacket.PingResponseStatus.UNREACHABLE;
-                            break;
                         }
 
                         if (end) {

src/main/java/eu/m724/autopeerer/common/packet/Packets.java

@@ -1,7 +1,9 @@
 package eu.m724.autopeerer.common.packet;
 
+import eu.m724.autopeerer.common.packet.client.LoginPacket;
 import eu.m724.autopeerer.common.packet.client.PingRequestPacket;
 import eu.m724.autopeerer.common.packet.client.SessionRequestPacket;
+import eu.m724.autopeerer.common.packet.server.LoginResponsePacket;
 import eu.m724.autopeerer.common.packet.server.PingResponsePacket;
 import eu.m724.autopeerer.common.packet.server.SessionResponsePacket;
 
@@ -14,7 +16,9 @@ public class Packets {
 
         Packet<?> packet = null;
 
-        if (id == 1) {
+        if (id == 0) {
+            packet = LoginResponsePacket.deserialize(buffer);
+        } else if (id == 1) {
             packet = PingRequestPacket.deserialize(buffer);
         } else if (id == 2) {
             packet = SessionRequestPacket.deserialize(buffer);
@@ -28,7 +32,9 @@ public class Packets {
 
         Packet<?> packet = null;
 
-        if (id == 1) {
+        if (id == 0) {
+            packet = LoginPacket.deserialize(buffer);
+        } else if (id == 1) {
             packet = PingResponsePacket.deserialize(buffer);
         } else if (id == 2) {
             packet = SessionResponsePacket.deserialize(buffer);

src/main/java/eu/m724/autopeerer/common/packet/client/LoginPacket.java

@@ -0,0 +1,33 @@
+package eu.m724.autopeerer.common.packet.client;
+
+import eu.m724.autopeerer.common.packet.Packet;
+
+import java.nio.ByteBuffer;
+
+public class LoginPacket implements Packet<LoginPacket> {
+    public final byte[] key;
+
+    public LoginPacket(byte[] key) {
+        this.key = key;
+        assert key.length == 8;
+    }
+
+    @Override
+    public byte getId() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuffer serialize() {
+        var buffer = ByteBuffer.allocate(8);
+        buffer.put(key);
+        return buffer;
+    }
+
+    public static LoginPacket deserialize(ByteBuffer buffer) {
+        var key = new byte[8];
+        buffer.get(key);
+
+        return new LoginPacket(key);
+    }
+}

src/main/java/eu/m724/autopeerer/common/packet/server/LoginResponsePacket.java

@@ -0,0 +1,36 @@
+package eu.m724.autopeerer.common.packet.server;
+
+import eu.m724.autopeerer.common.packet.Packet;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+public class LoginResponsePacket implements Packet<LoginResponsePacket> {
+    public final String nodeId;
+
+    public LoginResponsePacket(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    @Override
+    public byte getId() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuffer serialize() {
+        var nodeIdEncoded = nodeId.getBytes(StandardCharsets.UTF_8);
+        var buffer = ByteBuffer.allocate(1 + nodeIdEncoded.length);
+        buffer.put((byte) nodeIdEncoded.length);
+        buffer.put(nodeIdEncoded);
+        return buffer;
+    }
+
+    public static LoginResponsePacket deserialize(ByteBuffer buffer) {
+        var size = Byte.toUnsignedInt(buffer.get());
+        var nodeIdEncoded = new byte[size];
+        buffer.get(nodeIdEncoded);
+
+        return new LoginResponsePacket(new String(nodeIdEncoded, StandardCharsets.UTF_8));
+    }
+}

src/main/java/eu/m724/autopeerer/server/ClientState.java

@@ -8,8 +8,10 @@ import java.nio.ByteBuffer;
 import java.util.function.Consumer;
 
 public class ClientState {
+    public boolean authenticated = false;
     public final int clientId;
     public final WebSocket socket;
+    Node node;
 
     private final Consumer<ByteBuffer> sender;
 
@@ -22,4 +24,8 @@ public class ClientState {
     void send(Packet<?> packet) {
         Packets.send(packet, sender);
     }
+
+    void end() {
+        socket.close();
+    }
 }

src/main/java/eu/m724/autopeerer/server/Main.java

@@ -1,13 +1,32 @@
 package eu.m724.autopeerer.server;
 
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.Set;
+
 public class Main {
     public static void main(String[] args) {
         System.out.println("Hello world!");
 
-        var packetHandler = new PacketHandler();
-        var client = new MyWebsocketServer(packetHandler);
+        var config = new ServerConfiguration();
+        Set<Node> nodes;
+        try {
+            config.init();
+            nodes = config.loadNodes();
+            if (nodes.isEmpty())
+                System.err.println("Loaded 0 nodes. No client will be able to connect.");
+            else
+                System.out.printf("Loaded %d nodes.\n", nodes.size());
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to init configuration", e);
+        }
+
+        var packetHandler = new PacketHandler(nodes);
+        var client = new MyWebsocketServer(
+                new InetSocketAddress(config.getString("listen.address"), config.getInt("listen.port")),
+                packetHandler
+        );
 
-        client.setDaemon(false);
         client.start();
     }
 }

src/main/java/eu/m724/autopeerer/server/MyWebsocketServer.java

@@ -16,13 +16,15 @@ import java.util.Map;
 
 public class MyWebsocketServer extends WebSocketServer {
     private final PacketHandler packetHandler;
+
     private final Map<WebSocket, ClientState> states = new HashMap<>();
 
     private int id = 0;
 
-    public MyWebsocketServer(PacketHandler packetHandler) {
-        super(new InetSocketAddress("127.0.0.1", 8002));
+    public MyWebsocketServer(InetSocketAddress address, PacketHandler packetHandler) {
+        super(address);
         this.setReuseAddr(true);
+
         this.packetHandler = packetHandler;
     }
 
@@ -35,7 +37,8 @@ public class MyWebsocketServer extends WebSocketServer {
         // TODO testing
         try {
             state.send(new PingRequestPacket((short) 1, InetAddress.getByName("1.1.1.1")));
-            state.send(new PingRequestPacket((short) 2, InetAddress.getByName("1.1.1.2")));
+            state.send(new PingRequestPacket((short) 2, InetAddress.getByName("1.2.3.4")));
+            state.send(new PingRequestPacket((short) 3, InetAddress.getByName("1.1.1.2")));
 
             state.send(new SessionRequestPacket(
                     (short) 1,
@@ -52,7 +55,8 @@ public class MyWebsocketServer extends WebSocketServer {
     @Override
     public void onClose(WebSocket conn, int code, String reason, boolean remote) {
         var state = states.remove(conn);
-        System.out.printf("[%d] Disconnected: %s\n", state.clientId, conn.getRemoteSocketAddress().getHostString());
+        var id = state.authenticated ? state.node.id() : conn.getRemoteSocketAddress().getHostString();
+        System.out.printf("[%d] Disconnected: %s\n", state.clientId, id);
     }
 
     @Override

src/main/java/eu/m724/autopeerer/server/Node.java

@@ -0,0 +1,20 @@
+package eu.m724.autopeerer.server;
+
+import java.util.Base64;
+import java.util.Properties;
+
+public record Node(
+        String id,
+        byte[] key,
+        String name,
+        String host
+) {
+    static Node fromProperties(String id, Properties properties) {
+        return new Node(
+                id,
+                Base64.getDecoder().decode(properties.getProperty("key")),
+                properties.getProperty("name"),
+                properties.getProperty("host")
+        );
+    }
+}

src/main/java/eu/m724/autopeerer/server/PacketHandler.java

@@ -2,14 +2,21 @@ package eu.m724.autopeerer.server;
 
 import eu.m724.autopeerer.common.packet.Packet;
 import eu.m724.autopeerer.common.packet.Packets;
+import eu.m724.autopeerer.common.packet.client.LoginPacket;
 import eu.m724.autopeerer.common.packet.server.PingResponsePacket;
 import eu.m724.autopeerer.common.packet.server.SessionResponsePacket;
 
 import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
-import java.util.Base64;
+import java.util.*;
 
 public class PacketHandler {
+    private final Map<Node, ClientState> nodes = new HashMap<>();
+
+    public PacketHandler(Set<Node> nodes) {
+        nodes.forEach(n -> this.nodes.put(n, null));
+    }
+
     void handle(ClientState state, ByteBuffer bytes) {
         // TODO this is not safe but enough for now
         Packet<?> p;
@@ -29,6 +36,16 @@ public class PacketHandler {
             throw new RuntimeException(e);
         }
 
+        if (!state.authenticated) {
+            if (p instanceof LoginPacket packet) {
+                handleLogin(state, packet);
+            } else {
+                System.out.printf("[%d] Sent %s while unauthenticated\n", state.clientId, p.getClass().getName());
+            }
+
+            return;
+        }
+
         if (p instanceof PingResponsePacket packet) {
             handlePingResponse(state, packet);
         } else if (p instanceof SessionResponsePacket packet) {
@@ -36,6 +53,34 @@ public class PacketHandler {
         }
     }
 
+    void handleClose(ClientState state) {
+         nodes.entrySet().stream()
+                 .filter(e -> e.getValue().equals(state))
+                 .findFirst()
+                 .ifPresent(e -> nodes.remove(e.getKey()));
+    }
+
+    private void handleLogin(ClientState state, LoginPacket packet) {
+        var node = nodes.entrySet().stream().filter(e -> Arrays.equals(e.getKey().key(), packet.key)).findFirst().orElse(null);
+        if (node != null) {
+            if (node.getValue() != null) {
+                if (node.getValue().socket.isOpen()) { // if there WAS a connection
+                    System.out.printf("[%d] Tried to log in as %s, but is already logged in\n", state.clientId, node.getKey().id());
+                    state.end();
+                    return;
+                }
+            }
+
+            System.out.printf("[%d] Logged in as %s\n", state.clientId, node.getKey().id());
+            nodes.put(node.getKey(), state);
+            state.authenticated = true;
+            state.node = node.getKey();
+        } else {
+            System.out.printf("[%d] Tried to log in with invalid key\n", state.clientId);
+            state.end();
+        }
+    }
+
     private void handlePingResponse(ClientState state, PingResponsePacket packet) {
         System.out.printf("[%d] Ping response #%d: %s avg %.3f / mdev %.3f ms\n", state.clientId, packet.requestId, packet.status, packet.average, packet.meanDeviation);
     }

src/main/java/eu/m724/autopeerer/server/ServerConfiguration.java

@@ -0,0 +1,69 @@
+package eu.m724.autopeerer.server;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.HashSet;
+import java.util.Properties;
+import java.util.Set;
+
+public class ServerConfiguration {
+    private final File directory = new File("config");
+    private final File configFile = new File(directory, "server.properties");
+
+    private final Properties properties = new Properties();
+
+    public void init() throws IOException {
+        directory.mkdir();
+
+        if (!configFile.exists()) {
+            try (var is = getClass().getClassLoader().getResourceAsStream("server.properties")) {
+                Files.write(configFile.toPath(), is.readAllBytes());
+                properties.load(is);
+            }
+        }
+
+        try (var is = new FileInputStream(configFile)) {
+            properties.load(is);
+        }
+    }
+
+    public Set<Node> loadNodes() throws IOException {
+        var nd = new File(directory, "nodes");
+        nd.mkdir();
+
+        var nodes = new HashSet<Node>();
+
+        for (var f : nd.listFiles()) {
+            var properties = new Properties();
+
+            try (var is = new FileInputStream(f)) {
+                properties.load(is);
+            } catch (FileNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+
+            nodes.add(Node.fromProperties(f.getName().split("\\.")[0], properties));
+        }
+
+        return nodes;
+    }
+
+    public String getString(String property) {
+        return properties.getProperty(property);
+    }
+
+    public String getString(String property, String def) {
+        return properties.getProperty(property, def);
+    }
+
+    public int getInt(String property) {
+        return Integer.parseInt(getString(property));
+    }
+
+    public int getInt(String property, int def) {
+        return Integer.parseInt(getString(property, String.valueOf(def)));
+    }
+}

src/main/resources/server.properties

@@ -0,0 +1,2 @@
+listen.address=127.0.0.1
+listen.port=8002