feat: spam prevention

Author: RebeccaStevens

README.md

@@ -27,11 +27,23 @@ Default configuration:
 
 ```json
 {
+  {
   "Commands": {
     "Use": "code"
   },
   "Options": {
-    "displayPermissionErrors": true
+    "displayPermissionErrors": true,
+    "Spam Prevention": {
+      "Attempts": 5,
+      "Enable": true,
+      "Exponential Lock Out Time": true,
+      "Exponential Lockout Time": true,
+      "Lock Out Reset Factor": 5.0,
+      "Lock Out Time": 5.0,
+      "Lockout Reset Factor": 5.0,
+      "Lockout Time": 5.0,
+      "Window Time": 30.0
+    }
   }
 }
 ```
@@ -40,8 +52,15 @@ Default configuration:
 
 - `Commands` - Change the commands this plugin uses.
   - `Use` - Used to set the player's code.
-- `displayPermissionErrors` - If set to false, players won't be notified if
-  they don't have the right permissions to use this plugin.
+- `Options`
+  - `displayPermissionErrors` - If set to false, players won't be notified if they don't have the right permissions to use this plugin.
+  - `Spam Prevention` - Prevent players from changing their code too often to prevent abuse.
+    - `Enable` - Whether spam protection is enabled or not.
+    - `Attempts` - The number of code changes the player can make with in `Window Time` before being marked as spamming.
+    - `Window Time` - The time frame (in seconds) to count the number of code changes the player has made.
+    - `Lock Out Time` - How long (in seconds) a player will be locked out for. This number should be low if using exponential lock out times.
+    - `Exponential Lock Out Time` - If true, each time the player is locked out, they will be locked out for double the amount of time they were previously locked out for.
+    - `Lock Out Reset Factor` - Determines how long (as a multiples of lock out time) before the player is forgive for all previous lockout offenses (should be greater than 1 - has no effect if not using exponential lock out time).
 
 ## API
 

src/AutoCode.cs

@@ -143,6 +143,7 @@ protected override void LoadDefaultMessages()
           { "CodeUpdated", "Your new code is {0}." },
           { "InvalidArgsTooMany", "No additional arguments expected." },
           { "SyntaxError", "Syntax Error: expected \"{0}\"" },
+          { "SpamPrevention", "Too many recent code sets. Please wait {0} and try again." },
         }, this);
     }
 
@@ -189,7 +190,62 @@ public void SetCode(BasePlayer player, string code)
         return;
       }
 
+      double currentTime = Utils.CurrentTime();
+
+      if (AutoCodeConfig.SpamPreventionEnabled)
+      {
+        double timePassed = currentTime - settings.lastSet;
+        bool lockedOut = currentTime < settings.lockedOutUntil;
+        double lockOutFor = AutoCodeConfig.SpamLockOutTime * Math.Pow(2, (AutoCodeConfig.SpamLockOutTimeExponential ? settings.lockedOutTimes : 0));
+
+        if (!lockedOut)
+        {
+          // Called again within spam window time?
+          if (timePassed < AutoCodeConfig.SpamWindowTime)
+          {
+            settings.timesSetInSpamWindow++;
+          }
+          else
+          {
+            settings.timesSetInSpamWindow = 1;
+          }
+
+          // Too many recent changes?
+          if (settings.timesSetInSpamWindow > AutoCodeConfig.SpamAttempts)
+          {
+            // Locked them out.
+            settings.lockedOutUntil = currentTime + lockOutFor;
+            settings.lastLockedOut = currentTime;
+            settings.lockedOutTimes++;
+            settings.timesSetInSpamWindow = 0;
+            lockedOut = true;
+          }
+        }
+
+        // Locked out?
+        if (lockedOut)
+        {
+          player.ChatMessage(
+            string.Format(
+              lang.GetMessage("SpamPrevention", this, player.UserIDString),
+              TimeSpan.FromSeconds(Math.Ceiling(settings.lockedOutUntil - currentTime)).ToString(@"d\d\ h\h\ mm\m\ ss\s").TrimStart(' ', 'd', 'h', 'm', 's', '0'),
+              AutoCodeConfig.SpamLockOutTime,
+              AutoCodeConfig.SpamWindowTime
+            )
+          );
+          return;
+        }
+
+        // Haven't been locked out for a long time?
+        if (currentTime > settings.lastLockedOut + AutoCodeConfig.SpamLockOutResetFactor * lockOutFor)
+        {
+          // Reset their lockOuts.
+          settings.lockedOutTimes = 0;
+        }
+      }
+
       settings.code = code;
+      settings.lastSet = currentTime;
 
       player.ChatMessage(
         string.Format(
@@ -479,6 +535,14 @@ private static class AutoCodeConfig
       // Options.
       public static bool DisplayPermissionErrors { private set; get; }
 
+      // Spam prevention.
+      public static bool SpamPreventionEnabled { private set; get; }
+      public static int SpamAttempts { private set; get; }
+      public static double SpamLockOutTime { private set; get; }
+      public static double SpamWindowTime { private set; get; }
+      public static bool SpamLockOutTimeExponential { private set; get; }
+      public static double SpamLockOutResetFactor { private set; get; }
+
       // Meta.
       private static bool UnsavedChanges = false;
 
@@ -508,6 +572,14 @@ public static void LoadConfigValues()
         // Options.
         DisplayPermissionErrors = GetConfigValue(new string[] { "Options", "displayPermissionErrors" }, true);
 
+        // Spam prevention.
+        SpamPreventionEnabled = GetConfigValue(new string[] { "Options", "Spam Prevention", "Enable" }, true);
+        SpamAttempts = GetConfigValue(new string[] { "Options", "Spam Prevention", "Attempts" }, 5);
+        SpamLockOutTime = GetConfigValue(new string[] { "Options", "Spam Prevention", "Lock Out Time" }, 5.0);
+        SpamWindowTime = GetConfigValue(new string[] { "Options", "Spam Prevention", "Window Time" }, 30.0);
+        SpamLockOutTimeExponential = GetConfigValue(new string[] { "Options", "Spam Prevention", "Exponential Lock Out Time" }, true);
+        SpamLockOutResetFactor = GetConfigValue(new string[] { "Options", "Spam Prevention", "Lock Out Reset Factor" }, 5.0);
+
         // Commands.
         Commands.Use = GetConfigValue(new string[] { "Commands", "Use" }, Commands.Use);
 
@@ -548,6 +620,13 @@ private static void SetConfigValue<T>(string[] settingPath, T newValue)
         UnsavedChanges = true;
       }
     }
+    /**
+     * Utility functions.
+     */
+    private static class Utils
+    {
+      public static double CurrentTime() => DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1, 0, 0, 0)).TotalSeconds;
+    }
 
     /**
      * Everything related to the data the plugin needs to save.
@@ -592,6 +671,11 @@ public class PlayerSettings
         {
           public string code = null;
           public bool enabled = true;
+          public double lastSet = 0;
+          public int timesSetInSpamWindow = 0;
+          public double lockedOutUntil = 0;
+          public double lastLockedOut = 0;
+          public int lockedOutTimes = 0;
         }
       }
     }