Mojo cpp bindings: validation logic for incoming messages

mojo/public/cpp/bindings/tests/bounds_checker_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <limits>
+
+#include "mojo/public/cpp/bindings/lib/bounds_checker.h"
+#include "mojo/public/cpp/system/core.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace test {
+namespace {
+
+const void* ToPtr(uintptr_t ptr) {
+  return reinterpret_cast<const void*>(ptr);
+}
+
+bool AreEqualVectors(const std::vector<uintptr_t>& actual_values,
+                     const uintptr_t* expected_values,
+                     size_t expected_value_count) {
+  if (actual_values.size() != expected_value_count)
+    return false;
+
+  for (size_t i = 0; i < expected_value_count; ++i) {
+    if (actual_values[i] != expected_values[i])
+      return false;
+  }
+  return true;
+}
+
+#ifdef NDEBUG
+TEST(BoundsCheckerTest, MemoryRangeOverflow) {
+  internal::BoundsChecker
+      checker(ToPtr(std::numeric_limits<uintptr_t>::max() - 3000), 5000, 0);
+
+  EXPECT_FALSE(checker.IsWithinBounds(
+      ToPtr(std::numeric_limits<uintptr_t>::max() - 3000), 1));
+  EXPECT_FALSE(checker.ClaimMemory(
+      ToPtr(std::numeric_limits<uintptr_t>::max() - 3000), 1));
+}
+#endif
+
+TEST(BoundsCheckerTest, IsWithinBounds) {
+  {
+    internal::BoundsChecker checker(ToPtr(1234), 100, 0);
+
+    // Basics.
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(100), 5));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1230), 50));
+    EXPECT_TRUE(checker.IsWithinBounds(ToPtr(1234), 5));
+    EXPECT_TRUE(checker.IsWithinBounds(ToPtr(1240), 50));
+    EXPECT_TRUE(checker.IsWithinBounds(ToPtr(1234), 100));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1234), 200));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1240), 100));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(2234), 5));
+
+    // Should return false for empty ranges.
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(0), 0));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1200), 0));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1234), 0));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1240), 0));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(2234), 0));
+  }
+
+  {
+    // The valid memory range is empty.
+    internal::BoundsChecker checker(ToPtr(1234), 0, 0);
+
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1234), 1));
+    EXPECT_FALSE(checker.IsWithinBounds(ToPtr(1234), 0));
+  }
+
+  {
+    internal::BoundsChecker
+        checker(ToPtr(std::numeric_limits<uintptr_t>::max() - 2000), 1000, 0);
+
+    // Test overflow.
+    EXPECT_FALSE(checker.IsWithinBounds(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 1500), 4000));
+    EXPECT_FALSE(checker.IsWithinBounds(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 1500),
+        std::numeric_limits<uint32_t>::max()));
+
+    // This should be fine.
+    EXPECT_TRUE(checker.IsWithinBounds(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 1500), 200));
+  }
+}
+
+TEST(BoundsCheckerTest, ClaimHandle) {
+  {
+    internal::BoundsChecker checker(ToPtr(0), 0, 10);
+
+    // Basics.
+    EXPECT_TRUE(checker.ClaimHandle(Handle(0)));
+    EXPECT_FALSE(checker.ClaimHandle(Handle(0)));
+
+    EXPECT_TRUE(checker.ClaimHandle(Handle(9)));
+    EXPECT_FALSE(checker.ClaimHandle(Handle(10)));
+
+    // Should return true for invalid handle.
+    EXPECT_TRUE(checker.ClaimHandle(Handle(static_cast<MojoHandle>(-1))));
+    EXPECT_TRUE(checker.ClaimHandle(Handle(static_cast<MojoHandle>(-1))));
+  }
+
+  {
+    // No handle to claim.
+    internal::BoundsChecker checker(ToPtr(0), 0, 0);
+
+    EXPECT_FALSE(checker.ClaimHandle(Handle(0)));
+
+    // Should still return true for invalid handle.
+    EXPECT_TRUE(checker.ClaimHandle(Handle(static_cast<MojoHandle>(-1))));
+  }
+}
+
+TEST(BoundsCheckerTest, ClaimMemory) {
+  {
+    internal::BoundsChecker checker(ToPtr(1000), 2000, 0);
+
+    // Basics.
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(500), 100));
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(800), 300));
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(1000), 100));
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(1099), 100));
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(1100), 200));
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(2000), 1001));
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2000), 1000));
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(3000), 1));
+
+    // Test that we cannot claim a range that overlaps an existing one.
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(1400), 200));
+    // The same range.
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(1400), 200));
+    // Inclusion.
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(1450), 100));
+    // The head overlaps an existing range.
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(1450), 200));
+    // The tail overlaps an existing range.
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(1350), 200));
+  }
+
+  {
+    // No memory to claim.
+    internal::BoundsChecker checker(ToPtr(10000), 0, 0);
+
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(10000), 1));
+    EXPECT_FALSE(checker.ClaimMemory(ToPtr(10000), 0));
+  }
+
+  {
+    internal::BoundsChecker checker(ToPtr(1000), 2000, 0);
+
+    // Test the internal state of claimed ranges.
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2150), 50));
+    EXPECT_EQ(2u, checker.GetClaimedRangesForTesting().size());
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2350), 50));
+    EXPECT_EQ(4u, checker.GetClaimedRangesForTesting().size());
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2250), 50));
+    uintptr_t expected_values1[] = {2150, 2200, 2250, 2300, 2350, 2400};
+    EXPECT_TRUE(AreEqualVectors(checker.GetClaimedRangesForTesting(),
+                                expected_values1, 6u));
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2300), 25));
+    uintptr_t expected_values2[] = {2150, 2200, 2250, 2325, 2350, 2400};
+    EXPECT_TRUE(AreEqualVectors(checker.GetClaimedRangesForTesting(),
+                                expected_values2, 6u));
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2050), 100));
+    uintptr_t expected_values3[] = {2050, 2200, 2250, 2325, 2350, 2400};
+    EXPECT_TRUE(AreEqualVectors(checker.GetClaimedRangesForTesting(),
+                                expected_values3, 6u));
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2200), 50));
+    uintptr_t expected_values4[] = {2050, 2325, 2350, 2400};
+    EXPECT_TRUE(AreEqualVectors(checker.GetClaimedRangesForTesting(),
+                                expected_values4, 4u));
+
+    EXPECT_TRUE(checker.ClaimMemory(ToPtr(2325), 25));
+    uintptr_t expected_values5[] = {2050, 2400};
+    EXPECT_TRUE(AreEqualVectors(checker.GetClaimedRangesForTesting(),
+                                expected_values5, 2u));
+  }
+
+  {
+    internal::BoundsChecker
+        checker(ToPtr(std::numeric_limits<uintptr_t>::max() - 1000), 500, 0);
+
+    // Test overflow.
+    EXPECT_FALSE(checker.ClaimMemory(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 750), 4000));
+    EXPECT_FALSE(checker.ClaimMemory(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 750),
+        std::numeric_limits<uint32_t>::max()));
+
+    // This should be fine.
+    EXPECT_TRUE(checker.ClaimMemory(
+        ToPtr(std::numeric_limits<uintptr_t>::max() - 750), 200));
+  }
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace mojo