// Copyright 2015 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "snapshot/win/exception_snapshot_win.h"

#include <string>

#include "base/files/file_path.h"
#include "base/strings/stringprintf.h"
#include "base/strings/string16.h"
#include "base/strings/utf_string_conversions.h"
#include "client/crashpad_client.h"
#include "gtest/gtest.h"
#include "snapshot/win/process_snapshot_win.h"
#include "test/paths.h"
#include "test/win/child_launcher.h"
#include "util/file/file_io.h"
#include "util/thread/thread.h"
#include "util/win/exception_handler_server.h"
#include "util/win/registration_protocol_win.h"
#include "util/win/scoped_handle.h"
#include "util/win/scoped_process_suspend.h"

namespace crashpad {
namespace test {
namespace {

HANDLE DuplicateEvent(HANDLE process, HANDLE event) {
  HANDLE handle;
  if (DuplicateHandle(GetCurrentProcess(),
                      event,
                      process,
                      &handle,
                      SYNCHRONIZE | EVENT_MODIFY_STATE,
                      false,
                      0)) {
    return handle;
  }
  return nullptr;
}

class Delegate : public ExceptionHandlerServer::Delegate {
 public:
  Delegate(HANDLE server_ready, HANDLE completed_test_event)
      : server_ready_(server_ready),
        completed_test_event_(completed_test_event),
        break_near_(0) {}
  ~Delegate() override {}

  void set_break_near(WinVMAddress break_near) { break_near_ = break_near; }

  void ExceptionHandlerServerStarted() override { SetEvent(server_ready_); }

  unsigned int ExceptionHandlerServerException(
      HANDLE process,
      WinVMAddress exception_information_address) override {
    ScopedProcessSuspend suspend(process);
    ProcessSnapshotWin snapshot;
    snapshot.Initialize(process, ProcessSuspensionState::kSuspended);
    snapshot.InitializeException(exception_information_address);

    // Confirm the exception record was read correctly.
    EXPECT_NE(snapshot.Exception()->ThreadID(), 0u);
    EXPECT_EQ(snapshot.Exception()->Exception(), EXCEPTION_BREAKPOINT);

    // Verify the exception happened at the expected location with a bit of
    // slop space to allow for reading the current PC before the exception
    // happens. See CrashingChildProcess::Run().
    const uint64_t kAllowedOffset = 64;
    EXPECT_GT(snapshot.Exception()->ExceptionAddress(), break_near_);
    EXPECT_LT(snapshot.Exception()->ExceptionAddress(),
              break_near_ + kAllowedOffset);

    SetEvent(completed_test_event_);

    return snapshot.Exception()->Exception();
  }

 private:
  HANDLE server_ready_;  // weak
  HANDLE completed_test_event_;  // weak
  WinVMAddress break_near_;

  DISALLOW_COPY_AND_ASSIGN(Delegate);
};

// Runs the ExceptionHandlerServer on a background thread.
class RunServerThread : public Thread {
 public:
  // Instantiates a thread which will invoke server->Run(delegate, pipe_name);
  RunServerThread(ExceptionHandlerServer* server,
                  ExceptionHandlerServer::Delegate* delegate,
                  const std::string& pipe_name)
      : server_(server), delegate_(delegate), pipe_name_(pipe_name) {}
  ~RunServerThread() override {}

 private:
  // Thread:
  void ThreadMain() override { server_->Run(delegate_, pipe_name_); }

  ExceptionHandlerServer* server_;
  ExceptionHandlerServer::Delegate* delegate_;
  std::string pipe_name_;

  DISALLOW_COPY_AND_ASSIGN(RunServerThread);
};

// During destruction, ensures that the server is stopped and the background
// thread joined.
class ScopedStopServerAndJoinThread {
 public:
  ScopedStopServerAndJoinThread(ExceptionHandlerServer* server, Thread* thread)
      : server_(server), thread_(thread) {}
  ~ScopedStopServerAndJoinThread() {
    server_->Stop();
    thread_->Join();
  }

 private:
  ExceptionHandlerServer* server_;
  Thread* thread_;
  DISALLOW_COPY_AND_ASSIGN(ScopedStopServerAndJoinThread);
};

void TestCrashingChild(const base::string16& directory_modification) {
  // Set up the registration server on a background thread.
  std::string pipe_name = "\\\\.\\pipe\\handler_test_pipe_" +
                          base::StringPrintf("%08x", GetCurrentProcessId());
  ScopedKernelHANDLE server_ready(CreateEvent(nullptr, false, false, nullptr));
  ScopedKernelHANDLE completed(CreateEvent(nullptr, false, false, nullptr));
  Delegate delegate(server_ready.get(), completed.get());

  ExceptionHandlerServer exception_handler_server;
  RunServerThread server_thread(
      &exception_handler_server, &delegate, pipe_name);
  server_thread.Start();
  ScopedStopServerAndJoinThread scoped_stop_server_and_join_thread(
      &exception_handler_server, &server_thread);

  WaitForSingleObject(server_ready.get(), INFINITE);

  // Spawn a child process, passing it the pipe name to connect to.
  base::FilePath test_executable = Paths::Executable();
  std::wstring child_test_executable =
      test_executable.DirName()
          .Append(directory_modification)
          .Append(test_executable.BaseName().RemoveFinalExtension().value() +
                  L"_crashing_child.exe")
          .value();
  ChildLauncher child(child_test_executable, base::UTF8ToUTF16(pipe_name));
  child.Start();

  // The child tells us (approximately) where it will crash.
  WinVMAddress break_near_address;
  LoggingReadFile(child.stdout_read_handle(),
                  &break_near_address,
                  sizeof(break_near_address));
  delegate.set_break_near(break_near_address);

  // Wait for the child to crash and the exception information to be validated.
  WaitForSingleObject(completed.get(), INFINITE);
}

TEST(ExceptionSnapshotWinTest, ChildCrash) {
  TestCrashingChild(FILE_PATH_LITERAL("."));
}

#if defined(ARCH_CPU_64_BITS)
TEST(ExceptionSnapshotWinTest, ChildCrashWOW64) {
#ifndef NDEBUG
  TestCrashingChild(FILE_PATH_LITERAL("..\\..\\out\\Debug"));
#else
  TestCrashingChild(FILE_PATH_LITERAL("..\\..\\out\\Release"));
#endif
}
#endif  // ARCH_CPU_64_BITS

}  // namespace
}  // namespace test
}  // namespace crashpad