added connection key and recorded event to LoginLog

common/src/main/java/eu/mhsl/craftattack/spawn/common/appliances/tooling/loginLog/LoginLog.java

@@ -5,6 +5,8 @@ import eu.mhsl.craftattack.spawn.core.Main;
 import eu.mhsl.craftattack.spawn.core.api.server.HttpServer;
 import eu.mhsl.craftattack.spawn.core.appliance.Appliance;
 import eu.mhsl.craftattack.spawn.core.database.Database;
+import eu.mhsl.craftattack.spawn.core.event.LoginAttemptRecordedEvent;
+import eu.mhsl.craftattack.spawn.core.util.network.Networks;
 import eu.mhsl.craftattack.spawn.core.util.server.Floodgate;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer;
@@ -16,6 +18,8 @@ import org.jetbrains.annotations.Nullable;
 
 import java.net.InetAddress;
 import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.Statement;
 import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDateTime;
@@ -30,6 +34,7 @@ import java.util.concurrent.ConcurrentHashMap;
 /**
  * Records every login attempt (allowed or not) with its IP address in the table login_attempts
  * (schema: resources/migrations/loginLog). Basis for detecting ban evasion.
+ * After each insert a LoginAttemptRecordedEvent is fired on the database thread.
  * The website reports signups and logins of its users via POST /api/loginlog/website.
  * Never blocks or delays a login: writes run on the database thread, failures are only logged.
  */
@@ -101,19 +106,29 @@ public class LoginLog extends Appliance {
     }
 
     private void write(LoginAttempt attempt) {
-        String sql = "INSERT INTO login_attempts (at, uuid, name, ip, bedrock, stage, result, reason) VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
+        String network = Networks.networkOf(attempt.ip());
+        String sql = "INSERT INTO login_attempts (at, uuid, name, ip, network, bedrock, stage, result, reason) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)";
         this.database.execute("recording login attempt of " + attempt.name(), connection -> {
-            try(PreparedStatement statement = connection.prepareStatement(sql)) {
+            long id;
+            try(PreparedStatement statement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
                 statement.setObject(1, LocalDateTime.ofInstant(attempt.at(), ZoneOffset.UTC));
                 statement.setString(2, attempt.uuid().toString());
                 statement.setString(3, attempt.name());
                 statement.setString(4, attempt.ip());
-                statement.setBoolean(5, attempt.bedrock());
-                statement.setString(6, attempt.stage());
-                statement.setString(7, attempt.result());
-                statement.setString(8, attempt.reason());
+                statement.setString(5, network);
+                statement.setBoolean(6, attempt.bedrock());
+                statement.setString(7, attempt.stage());
+                statement.setString(8, attempt.result());
+                statement.setString(9, attempt.reason());
                 statement.executeUpdate();
+                try(ResultSet keys = statement.getGeneratedKeys()) {
+                    if(!keys.next()) return;
+                    id = keys.getLong(1);
+                }
             }
+            Bukkit.getPluginManager().callEvent(new LoginAttemptRecordedEvent(new LoginAttemptRecordedEvent.RecordedAttempt(
+                id, attempt.at(), attempt.uuid(), attempt.name(), attempt.ip(), network, attempt.stage(), attempt.result()
+            )));
         });
     }
 

common/src/main/resources/migrations/loginLog/002_add_network.sql

@@ -0,0 +1,6 @@
+-- Connection key per attempt: the IPv4 address or the IPv6 /64 prefix. Groups accounts by internet connection.
+ALTER TABLE login_attempts
+    ADD COLUMN network VARCHAR(45) NULL COMMENT 'IPv4 address or IPv6 /64 prefix, NULL if unknown' AFTER ip,
+    ADD KEY idx_network_at (network, at);
+
+UPDATE login_attempts SET network = ip WHERE ip REGEXP '^[0-9]{1,3}([.][0-9]{1,3}){3}$';

core/src/main/java/eu/mhsl/craftattack/spawn/core/event/LoginAttemptRecordedEvent.java

@@ -0,0 +1,49 @@
+package eu.mhsl.craftattack.spawn.core.event;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.time.Instant;
+import java.util.UUID;
+
+/**
+ * Fired after a login attempt was stored in login_attempts. Called on the database thread:
+ * handlers must return quickly and must never wait for results of the shared Database.
+ */
+public class LoginAttemptRecordedEvent extends Event {
+    private static final HandlerList HANDLERS = new HandlerList();
+
+    @Override
+    public @NotNull HandlerList getHandlers() {
+        return HANDLERS;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLERS;
+    }
+
+    public record RecordedAttempt(
+        long id,
+        Instant at,
+        UUID uuid,
+        String name,
+        String ip,
+        @Nullable String network,
+        String stage,
+        String result
+    ) {
+    }
+
+    private final RecordedAttempt attempt;
+
+    public LoginAttemptRecordedEvent(RecordedAttempt attempt) {
+        super(true);
+        this.attempt = attempt;
+    }
+
+    public RecordedAttempt getAttempt() {
+        return this.attempt;
+    }
+}

core/src/main/java/eu/mhsl/craftattack/spawn/core/util/network/Networks.java

@@ -0,0 +1,72 @@
+package eu.mhsl.craftattack.spawn.core.util.network;
+
+import org.jetbrains.annotations.Nullable;
+
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.StringJoiner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Groups IP addresses by internet connection: an IPv4 address stands for itself,
+ * an IPv6 address for its /64 prefix (one prefix per household line).
+ */
+public final class Networks {
+    private static final Pattern IPV4 = Pattern.compile("^(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})$");
+    private static final Pattern IPV6 = Pattern.compile("^[0-9a-fA-F:.]*:[0-9a-fA-F:.]*$");
+    private static final String IPV6_SUFFIX = "::/64";
+
+    private Networks() {
+    }
+
+    /**
+     * @return the connection key ("93.204.10.20" or "2003:e1:1f00:ab00::/64"), or null if the text is no IP address
+     */
+    public static @Nullable String networkOf(@Nullable String ip) {
+        if(ip == null) return null;
+        String text = ip.trim();
+
+        Matcher ipv4 = IPV4.matcher(text);
+        if(ipv4.matches()) return ipv4Of(ipv4);
+        if(!IPV6.matcher(text).matches()) return null;
+
+        InetAddress address;
+        try {
+            // the text contains a colon, so it is parsed as IPv6 literal and never resolved via DNS
+            address = InetAddress.getByName(text);
+        } catch(UnknownHostException e) {
+            return null;
+        }
+        if(address instanceof Inet4Address) return address.getHostAddress();
+        byte[] bytes = address.getAddress();
+        return String.format("%x:%x:%x:%x%s", group(bytes, 0), group(bytes, 2), group(bytes, 4), group(bytes, 6), IPV6_SUFFIX);
+    }
+
+    /**
+     * Shortened form for display: "93.204.x.x" or "2003:e1:x:x::/64".
+     */
+    public static String mask(String network) {
+        if(network.endsWith(IPV6_SUFFIX)) {
+            String[] groups = network.substring(0, network.length() - IPV6_SUFFIX.length()).split(":");
+            return groups[0] + ":" + groups[1] + ":x:x" + IPV6_SUFFIX;
+        }
+        String[] octets = network.split("\\.");
+        return octets.length == 4 ? octets[0] + "." + octets[1] + ".x.x" : network;
+    }
+
+    private static @Nullable String ipv4Of(Matcher matcher) {
+        StringJoiner joiner = new StringJoiner(".");
+        for(int i = 1; i <= 4; i++) {
+            int octet = Integer.parseInt(matcher.group(i));
+            if(octet > 255) return null;
+            joiner.add(Integer.toString(octet));
+        }
+        return joiner.toString();
+    }
+
+    private static int group(byte[] bytes, int offset) {
+        return ((bytes[offset] & 0xff) << 8) | (bytes[offset + 1] & 0xff);
+    }
+}