Notification limits (#1100)

neo/SmartContract/InteropService.cs

@@ -14,6 +14,8 @@
 using System.Linq;
 using System.Numerics;
 using System.Text;
+using Array = Neo.VM.Types.Array;
+using Boolean = Neo.VM.Types.Boolean;
 
 namespace Neo.SmartContract
 {
@@ -22,6 +24,7 @@ public static partial class InteropService
         public const long GasPerByte = 100000;
         public const int MaxStorageKeySize = 64;
         public const int MaxStorageValueSize = ushort.MaxValue;
+        public const int MaxNotificationSize = 1024;
 
         private static readonly Dictionary<uint, InteropDescriptor> methods = new Dictionary<uint, InteropDescriptor>();
 
@@ -32,8 +35,8 @@ public static partial class InteropService
         public static readonly uint System_Runtime_Platform = Register("System.Runtime.Platform", Runtime_Platform, 0_00000250, TriggerType.All);
         public static readonly uint System_Runtime_GetTrigger = Register("System.Runtime.GetTrigger", Runtime_GetTrigger, 0_00000250, TriggerType.All);
         public static readonly uint System_Runtime_CheckWitness = Register("System.Runtime.CheckWitness", Runtime_CheckWitness, 0_00030000, TriggerType.All);
-        public static readonly uint System_Runtime_Notify = Register("System.Runtime.Notify", Runtime_Notify, 0_00000250, TriggerType.All);
-        public static readonly uint System_Runtime_Log = Register("System.Runtime.Log", Runtime_Log, 0_00300000, TriggerType.All);
+        public static readonly uint System_Runtime_Notify = Register("System.Runtime.Notify", Runtime_Notify, 0_01000000, TriggerType.All);
+        public static readonly uint System_Runtime_Log = Register("System.Runtime.Log", Runtime_Log, 0_01000000, TriggerType.All);
         public static readonly uint System_Runtime_GetTime = Register("System.Runtime.GetTime", Runtime_GetTime, 0_00000250, TriggerType.Application);
         public static readonly uint System_Runtime_Serialize = Register("System.Runtime.Serialize", Runtime_Serialize, 0_00100000, TriggerType.All);
         public static readonly uint System_Runtime_Deserialize = Register("System.Runtime.Deserialize", Runtime_Deserialize, 0_00500000, TriggerType.All);
@@ -56,6 +59,54 @@ public static partial class InteropService
         public static readonly uint System_Storage_Delete = Register("System.Storage.Delete", Storage_Delete, 0_01000000, TriggerType.Application);
         public static readonly uint System_StorageContext_AsReadOnly = Register("System.StorageContext.AsReadOnly", StorageContext_AsReadOnly, 0_00000400, TriggerType.Application);
 
+        private static bool CheckItemForNotification(StackItem state)
+        {
+            int size = 0;
+            List<StackItem> items_checked = new List<StackItem>();
+            Queue<StackItem> items_unchecked = new Queue<StackItem>();
+            while (true)
+            {
+                switch (state)
+                {
+                    case Struct array:
+                        foreach (StackItem item in array)
+                            items_unchecked.Enqueue(item);
+                        break;
+                    case Array array:
+                        if (items_checked.All(p => !ReferenceEquals(p, array)))
+                        {
+                            items_checked.Add(array);
+                            foreach (StackItem item in array)
+                                items_unchecked.Enqueue(item);
+                        }
+                        break;
+                    case Boolean _:
+                    case ByteArray _:
+                    case Integer _:
+                        size += state.GetByteLength();
+                        break;
+                    case Null _:
+                        break;
+                    case InteropInterface _:
+                        return false;
+                    case Map map:
+                        if (items_checked.All(p => !ReferenceEquals(p, map)))
+                        {
+                            items_checked.Add(map);
+                            foreach (var pair in map)
+                            {
+                                size += pair.Key.GetByteLength();
+                                items_unchecked.Enqueue(pair.Value);
+                            }
+                        }
+                        break;
+                }
+                if (size > MaxNotificationSize) return false;
+                if (items_unchecked.Count == 0) return true;
+                state = items_unchecked.Dequeue();
+            }
+        }
+
         private static bool CheckStorageContext(ApplicationEngine engine, StorageContext context)
         {
             ContractState contract = engine.Snapshot.Contracts.TryGet(context.ScriptHash);
@@ -194,13 +245,17 @@ private static bool Runtime_CheckWitness(ApplicationEngine engine)
 
         private static bool Runtime_Notify(ApplicationEngine engine)
         {
-            engine.SendNotification(engine.CurrentScriptHash, engine.CurrentContext.EvaluationStack.Pop());
+            StackItem state = engine.CurrentContext.EvaluationStack.Pop();
+            if (!CheckItemForNotification(state)) return false;
+            engine.SendNotification(engine.CurrentScriptHash, state);
             return true;
         }
 
         private static bool Runtime_Log(ApplicationEngine engine)
         {
-            string message = Encoding.UTF8.GetString(engine.CurrentContext.EvaluationStack.Pop().GetByteArray());
+            byte[] state = engine.CurrentContext.EvaluationStack.Pop().GetByteArray();
+            if (state.Length > MaxNotificationSize) return false;
+            string message = Encoding.UTF8.GetString(state);
             engine.SendLog(engine.CurrentScriptHash, message);
             return true;
         }