handle_closer_test.cc

// Copyright (c) 2011 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.h>
#include <stddef.h>

#include "base/strings/stringprintf.h"
#include "base/win/scoped_handle.h"
#include "sandbox/win/src/handle_closer_agent.h"
#include "sandbox/win/src/nt_internals.h"
#include "sandbox/win/src/sandbox.h"
#include "sandbox/win/src/sandbox_factory.h"
#include "sandbox/win/src/target_services.h"
#include "sandbox/win/tests/common/controller.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

const wchar_t* kFileExtensions[] = {L".1", L".2", L".3", L".4"};

// Returns a handle to a unique marker file that can be retrieved between runs.
HANDLE GetMarkerFile(const wchar_t* extension) {
  wchar_t path_buffer[MAX_PATH + 1];
  CHECK(::GetTempPath(MAX_PATH, path_buffer));
  std::wstring marker_path = path_buffer;
  marker_path += L"\\sbox_marker_";

  // Generate a unique value from the exe's size and timestamp.
  CHECK(::GetModuleFileName(nullptr, path_buffer, MAX_PATH));
  base::win::ScopedHandle module(
      ::CreateFile(path_buffer, FILE_READ_ATTRIBUTES, FILE_SHARE_READ, nullptr,
                   OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr));
  CHECK(module.IsValid());
  FILETIME timestamp;
  CHECK(::GetFileTime(module.Get(), &timestamp, nullptr, nullptr));
  marker_path +=
      base::StringPrintf(L"%08x%08x%08x", ::GetFileSize(module.Get(), nullptr),
                         timestamp.dwLowDateTime, timestamp.dwHighDateTime);
  marker_path += extension;

  // Make the file delete-on-close so cleanup is automatic.
  return CreateFile(marker_path.c_str(), FILE_ALL_ACCESS,
                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
                    nullptr, OPEN_ALWAYS, FILE_FLAG_DELETE_ON_CLOSE, nullptr);
}

// Returns type infomation for an NT object. This routine is expected to be
// called for invalid handles so it catches STATUS_INVALID_HANDLE exceptions
// that can be generated when handle tracing is enabled.
NTSTATUS QueryObjectTypeInformation(HANDLE handle, void* buffer, ULONG* size) {
  static NtQueryObject QueryObject = nullptr;
  if (!QueryObject)
    ResolveNTFunctionPtr("NtQueryObject", &QueryObject);

  NTSTATUS status = STATUS_UNSUCCESSFUL;
  __try {
    status = QueryObject(handle, ObjectTypeInformation, buffer, *size, size);
  } __except (GetExceptionCode() == STATUS_INVALID_HANDLE
                  ? EXCEPTION_EXECUTE_HANDLER
                  : EXCEPTION_CONTINUE_SEARCH) {
    status = STATUS_INVALID_HANDLE;
  }
  return status;
}

// Used by the thread pool tests.
HANDLE finish_event;
const int kWaitCount = 20;

}  // namespace

namespace sandbox {

// Checks for the presence of a list of files (in object path form).
// Format: CheckForFileHandle (Y|N) \path\to\file1 [\path\to\file2 ...]
// - Y or N depending if the file should exist or not.
SBOX_TESTS_COMMAND int CheckForFileHandles(int argc, wchar_t** argv) {
  if (argc < 2)
    return SBOX_TEST_FAILED_TO_RUN_TEST;
  bool should_find = argv[0][0] == L'Y';
  if (argv[0][1] != L'\0' || (!should_find && argv[0][0] != L'N'))
    return SBOX_TEST_FAILED_TO_RUN_TEST;

  static int state = BEFORE_INIT;
  switch (state++) {
    case BEFORE_INIT:
      // Create a unique marker file that is open while the test is running.
      // The handles leak, but it will be closed by the test or on exit.
      for (const wchar_t* kExtension : kFileExtensions)
        CHECK_NE(GetMarkerFile(kExtension), INVALID_HANDLE_VALUE);
      return SBOX_TEST_SUCCEEDED;

    case AFTER_REVERT: {
      // Brute force the handle table to find what we're looking for.
      DWORD handle_count = UINT_MAX;
      const int kInvalidHandleThreshold = 100;
      const size_t kHandleOffset = 4;  // Handles are always a multiple of 4.
      HANDLE handle = nullptr;
      int invalid_count = 0;
      std::wstring handle_name;

      if (!::GetProcessHandleCount(::GetCurrentProcess(), &handle_count))
        return SBOX_TEST_FAILED_TO_RUN_TEST;

      while (handle_count && invalid_count < kInvalidHandleThreshold) {
        reinterpret_cast<size_t&>(handle) += kHandleOffset;
        if (GetHandleName(handle, &handle_name)) {
          for (int i = 1; i < argc; ++i) {
            if (handle_name == argv[i])
              return should_find ? SBOX_TEST_SUCCEEDED : SBOX_TEST_FAILED;
          }
          --handle_count;
        } else {
          ++invalid_count;
        }
      }

      return should_find ? SBOX_TEST_FAILED : SBOX_TEST_SUCCEEDED;
    }

    default:  // Do nothing.
      break;
  }

  return SBOX_TEST_SUCCEEDED;
}

// Checks that supplied handle is an Event and it's not waitable.
// Format: CheckForEventHandles
SBOX_TESTS_COMMAND int CheckForEventHandles(int argc, wchar_t** argv) {
  static int state = BEFORE_INIT;
  static std::vector<HANDLE> to_check;

  switch (state++) {
    case BEFORE_INIT:
      // Create a unique marker file that is open while the test is running.
      for (const wchar_t* kExtension : kFileExtensions) {
        HANDLE handle = GetMarkerFile(kExtension);
        CHECK_NE(handle, INVALID_HANDLE_VALUE);
        to_check.push_back(handle);
      }
      return SBOX_TEST_SUCCEEDED;

    case AFTER_REVERT:
      for (HANDLE handle : to_check) {
        // Set up buffers for the type info and the name.
        std::vector<BYTE> type_info_buffer(sizeof(OBJECT_TYPE_INFORMATION) +
                                           32 * sizeof(wchar_t));
        OBJECT_TYPE_INFORMATION* type_info =
            reinterpret_cast<OBJECT_TYPE_INFORMATION*>(&(type_info_buffer[0]));
        NTSTATUS rc;

        // Get the type name, reusing the buffer.
        ULONG size = static_cast<ULONG>(type_info_buffer.size());
        rc = QueryObjectTypeInformation(handle, type_info, &size);
        while (rc == STATUS_INFO_LENGTH_MISMATCH ||
               rc == STATUS_BUFFER_OVERFLOW) {
          type_info_buffer.resize(size + sizeof(wchar_t));
          type_info = reinterpret_cast<OBJECT_TYPE_INFORMATION*>(
              &(type_info_buffer[0]));
          rc = QueryObjectTypeInformation(handle, type_info, &size);
          // Leave padding for the nul terminator.
          if (NT_SUCCESS(rc) && size == type_info_buffer.size())
            rc = STATUS_INFO_LENGTH_MISMATCH;
        }

        CHECK(NT_SUCCESS(rc));
        CHECK(type_info->Name.Buffer);

        type_info->Name.Buffer[type_info->Name.Length / sizeof(wchar_t)] =
            L'\0';

        // Should be an Event now.
        CHECK_EQ(wcslen(type_info->Name.Buffer), 5U);
        CHECK_EQ(wcscmp(L"Event", type_info->Name.Buffer), 0);

        // Should not be able to wait.
        CHECK_EQ(WaitForSingleObject(handle, INFINITE), WAIT_FAILED);

        // Should be able to close.
        CHECK(::CloseHandle(handle));
      }
      return SBOX_TEST_SUCCEEDED;

    default:  // Do nothing.
      break;
  }

  return SBOX_TEST_SUCCEEDED;
}

TEST(HandleCloserTest, CheckForMarkerFiles) {
  TestRunner runner;
  runner.SetTimeout(2000);
  runner.SetTestState(EVERY_STATE);

  std::wstring command = std::wstring(L"CheckForFileHandles Y");
  for (const wchar_t* kExtension : kFileExtensions) {
    std::wstring handle_name;
    base::win::ScopedHandle marker(GetMarkerFile(kExtension));
    CHECK(marker.IsValid());
    CHECK(sandbox::GetHandleName(marker.Get(), &handle_name));
    command += (L" ");
    command += handle_name;
  }

  EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(command.c_str()))
      << "Failed: " << command;
}

TEST(HandleCloserTest, CloseMarkerFiles) {
  TestRunner runner;
  runner.SetTimeout(2000);
  runner.SetTestState(EVERY_STATE);
  sandbox::TargetPolicy* policy = runner.GetPolicy();

  std::wstring command = std::wstring(L"CheckForFileHandles N");
  for (const wchar_t* kExtension : kFileExtensions) {
    std::wstring handle_name;
    base::win::ScopedHandle marker(GetMarkerFile(kExtension));
    CHECK(marker.IsValid());
    CHECK(sandbox::GetHandleName(marker.Get(), &handle_name));
    CHECK_EQ(policy->AddKernelObjectToClose(L"File", handle_name.c_str()),
             SBOX_ALL_OK);
    command += (L" ");
    command += handle_name;
  }

  EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(command.c_str()))
      << "Failed: " << command;
}

TEST(HandleCloserTest, CheckStuffedHandle) {
  TestRunner runner;
  runner.SetTimeout(2000);
  runner.SetTestState(EVERY_STATE);
  sandbox::TargetPolicy* policy = runner.GetPolicy();

  for (const wchar_t* kExtension : kFileExtensions) {
    std::wstring handle_name;
    base::win::ScopedHandle marker(GetMarkerFile(kExtension));
    CHECK(marker.IsValid());
    CHECK(sandbox::GetHandleName(marker.Get(), &handle_name));
    CHECK_EQ(policy->AddKernelObjectToClose(L"File", handle_name.c_str()),
             SBOX_ALL_OK);
  }

  EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(L"CheckForEventHandles"));
}

void WINAPI ThreadPoolTask(void* event, BOOLEAN timeout) {
  static volatile LONG waiters_remaining = kWaitCount;
  CHECK(!timeout);
  CHECK(::CloseHandle(event));
  if (::InterlockedDecrement(&waiters_remaining) == 0)
    CHECK(::SetEvent(finish_event));
}

// Run a thread pool inside a sandbox without a CSRSS connection.
SBOX_TESTS_COMMAND int RunThreadPool(int argc, wchar_t** argv) {
  HANDLE wait_list[20];
  finish_event = ::CreateEvent(nullptr, true, false, nullptr);
  CHECK(finish_event);

  // Set up a bunch of waiters.
  HANDLE pool = nullptr;
  for (int i = 0; i < kWaitCount; ++i) {
    HANDLE event = ::CreateEvent(nullptr, true, false, nullptr);
    CHECK(event);
    CHECK(::RegisterWaitForSingleObject(&pool, event, ThreadPoolTask, event,
                                        INFINITE, WT_EXECUTEONLYONCE));
    wait_list[i] = event;
  }

  // Signal all the waiters.
  for (int i = 0; i < kWaitCount; ++i)
    CHECK(::SetEvent(wait_list[i]));

  CHECK_EQ(::WaitForSingleObject(finish_event, INFINITE), WAIT_OBJECT_0);
  CHECK(::CloseHandle(finish_event));

  return SBOX_TEST_SUCCEEDED;
}

TEST(HandleCloserTest, RunThreadPool) {
  TestRunner runner;
  runner.SetTimeout(2000);
  runner.SetTestState(AFTER_REVERT);

  // Sandbox policy will determine which platforms to disconnect CSRSS and when
  // to close the CSRSS handle.

  EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(L"RunThreadPool"));
}

}  // namespace sandbox