RateControl

2026-07-30 17:30:40 +00:00 · 2026-07-14 02:27:33 +03:00
parent 4f6d2d0801
commit 1ca9fc477b
19 changed files with 879 additions and 146 deletions
@@ -0,0 +1,61 @@
+using Esiur.Protocol;
+using Esiur.Resource;
+using System;
+using System.IO;
+
+namespace Esiur.Data;
+
+/// <summary>
+/// Raised when untrusted input exceeds a configured parser budget.
+/// </summary>
+public sealed class ParserLimitException : Exception
+{
+    public ParserLimitException(string message) : base(message)
+    {
+    }
+}
+
+internal static class ParserGuard
+{
+    internal static Warehouse? GetWarehouse(EpConnection? connection)
+        => connection?.ParsingWarehouse;
+
+    internal static void EnsurePacketSize(Warehouse? warehouse, ulong size)
+    {
+        var limit = warehouse?.Configuration.Parser.MaximumPacketSize ?? 0;
+        if (limit > 0 && size > limit)
+            throw new ParserLimitException(
+                $"Declared packet payload of {size} bytes exceeds the {limit}-byte limit.");
+    }
+
+    internal static void EnsureAllocation(Warehouse? warehouse, ulong size, string kind)
+    {
+        var limit = warehouse?.Configuration.Parser.MaximumAllocationSize ?? 0;
+        if (limit > 0 && size > limit)
+            throw new ParserLimitException(
+                $"Decoded {kind} allocation of {size} bytes exceeds the {limit}-byte limit.");
+    }
+
+    internal static void EnsureCollectionCount(
+        Warehouse? warehouse,
+        int count,
+        int estimatedBytesPerItem = 0)
+    {
+        var configuration = warehouse?.Configuration.Parser;
+        if (configuration == null)
+            return;
+
+        if (configuration.MaximumCollectionItems > 0 && count > configuration.MaximumCollectionItems)
+            throw new ParserLimitException(
+                $"Decoded collection count of {count} exceeds the {configuration.MaximumCollectionItems}-item limit.");
+
+        if (estimatedBytesPerItem > 0)
+            EnsureAllocation(
+                warehouse,
+                (ulong)count * (ulong)estimatedBytesPerItem,
+                "collection");
+    }
+
+    internal static ulong MultiplySaturated(ulong value, ulong multiplier)
+        => value > ulong.MaxValue / multiplier ? ulong.MaxValue : value * multiplier;
+}