// Copyright 2018 The Chromium OS 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 "shill/process_manager.h"

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include <base/bind.h>
#include <brillo/minijail/mock_minijail.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include "shill/test_event_dispatcher.h"

using base::Bind;
using base::Callback;
using base::CancelableClosure;
using base::Closure;
using base::Unretained;
using std::string;
using std::vector;
using testing::_;
using testing::DoAll;
using testing::Return;
using testing::SetArgPointee;
using testing::StrEq;

namespace shill {

class ProcessManagerTest : public testing::Test {
 public:
  ProcessManagerTest() : process_manager_(ProcessManager::GetInstance()) {}

  void SetUp() override {
    process_manager_->dispatcher_ = &dispatcher_;
    process_manager_->minijail_ = &minijail_;
  }

  void TearDown() override {
    process_manager_->watched_processes_.clear();
    process_manager_->pending_termination_processes_.clear();
  }

  void AddWatchedProcess(pid_t pid, const Callback<void(int)>& callback) {
    process_manager_->watched_processes_[pid] = std::move(callback);
  }

  void AddTerminateProcess(pid_t pid,
                           std::unique_ptr<CancelableClosure> timeout_handler) {
    process_manager_->pending_termination_processes_[pid] =
        std::move(timeout_handler);
  }

  void AssertEmptyWatchedProcesses() {
    EXPECT_TRUE(process_manager_->watched_processes_.empty());
  }

  void AssertNonEmptyWatchedProcesses() {
    EXPECT_FALSE(process_manager_->watched_processes_.empty());
  }

  void AssertEmptyTerminateProcesses() {
    EXPECT_TRUE(process_manager_->pending_termination_processes_.empty());
  }

  void OnProcessExited(pid_t pid, int exit_status) {
    siginfo_t info;
    info.si_status = exit_status;
    process_manager_->OnProcessExited(pid, info);
  }

  void OnTerminationTimeout(pid_t pid, bool kill_signal) {
    process_manager_->ProcessTerminationTimeoutHandler(pid, kill_signal);
  }

 protected:
  class CallbackObserver {
   public:
    CallbackObserver()
        : exited_callback_(
              Bind(&CallbackObserver::OnProcessExited, Unretained(this))),
          termination_timeout_callback_(Bind(
              &CallbackObserver::OnTerminationTimeout, Unretained(this))) {}
    virtual ~CallbackObserver() = default;

    MOCK_METHOD(void, OnProcessExited, (int));
    MOCK_METHOD(void, OnTerminationTimeout, ());

    Callback<void(int)> exited_callback_;
    Closure termination_timeout_callback_;
  };

  EventDispatcherForTest dispatcher_;
  brillo::MockMinijail minijail_;
  ProcessManager* process_manager_;
};

MATCHER_P2(IsProcessArgs, program, args, "") {
  if (string(arg[0]) != program) {
    return false;
  }
  int index = 1;
  for (const auto& option : args) {
    if (string(arg[index++]) != option) {
      return false;
    }
  }
  return arg[index] == nullptr;
}

TEST_F(ProcessManagerTest, WatchedProcessExited) {
  const pid_t kPid = 123;
  const int kExitStatus = 1;
  CallbackObserver observer;
  AddWatchedProcess(kPid, observer.exited_callback_);

  EXPECT_CALL(observer, OnProcessExited(kExitStatus)).Times(1);
  OnProcessExited(kPid, kExitStatus);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest, TerminateProcessExited) {
  const pid_t kPid = 123;
  CallbackObserver observer;
  auto timeout_handler = std::make_unique<CancelableClosure>(
      observer.termination_timeout_callback_);
  AddTerminateProcess(kPid, std::move(timeout_handler));

  EXPECT_CALL(observer, OnTerminationTimeout()).Times(0);
  OnProcessExited(kPid, 1);
  AssertEmptyTerminateProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesReturnsPidAndWatchesChild) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = {"-b", "-g"};
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;
  const pid_t kPid = 123;
  int stdin_fd;
  int stdout_fd;
  int stderr_fd;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(true));
  EXPECT_CALL(minijail_, UseCapabilities(_, kCapMask)).Times(1);
  EXPECT_CALL(minijail_, ResetSignalMask(_)).Times(1);
  EXPECT_CALL(minijail_, CloseOpenFds(_)).Times(1);
  EXPECT_CALL(minijail_, PreserveFd(_, _, _)).Times(3);
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_,  // minijail*
                                 IsProcessArgs(kProgram, kArgs),
                                 _,  // pid_t*
                                 &stdin_fd, &stdout_fd, &stderr_fd))
      .WillOnce(DoAll(SetArgPointee<2>(kPid), Return(true)));
  struct std_file_descriptors std_fds {
    &stdin_fd, &stdout_fd, &stderr_fd
  };
  pid_t actual_pid = process_manager_->StartProcessInMinijailWithPipes(
      FROM_HERE, base::FilePath(kProgram), kArgs, kUser, kGroup, kCapMask,
      false, true, Callback<void(int)>(), std_fds);
  EXPECT_EQ(kPid, actual_pid);
  AssertNonEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesHandlesFailureOfDropRoot) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = {"-b", "-g"};
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(false));
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_, IsProcessArgs(kProgram, kArgs), _, _, _, _))
      .Times(0);
  struct std_file_descriptors std_fds = {nullptr, nullptr, nullptr};
  pid_t actual_pid = process_manager_->StartProcessInMinijailWithPipes(
      FROM_HERE, base::FilePath(kProgram), kArgs, kUser, kGroup, kCapMask,
      false, false, Callback<void(int)>(), std_fds);
  EXPECT_EQ(-1, actual_pid);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest,
       StartProcessInMinijailWithPipesHandlesFailureOfRunAndDestroy) {
  const string kProgram = "/usr/bin/dump";
  const vector<string> kArgs = {"-b", "-g"};
  const string kUser = "user";
  const string kGroup = "group";
  const uint64_t kCapMask = 1;

  EXPECT_CALL(minijail_, DropRoot(_, StrEq(kUser), StrEq(kGroup)))
      .WillOnce(Return(true));
  EXPECT_CALL(minijail_, UseCapabilities(_, kCapMask)).Times(1);
  EXPECT_CALL(minijail_,
              RunPipesAndDestroy(_, IsProcessArgs(kProgram, kArgs), _, _, _, _))
      .WillOnce(Return(false));
  struct std_file_descriptors std_fds = {nullptr, nullptr, nullptr};
  pid_t actual_pid = process_manager_->StartProcessInMinijailWithPipes(
      FROM_HERE, base::FilePath(kProgram), kArgs, kUser, kGroup, kCapMask,
      false, false, Callback<void(int)>(), std_fds);
  EXPECT_EQ(-1, actual_pid);
  AssertEmptyWatchedProcesses();
}

TEST_F(ProcessManagerTest, UpdateExitCallbackUpdatesCallback) {
  const pid_t kPid = 123;
  const int kExitStatus = 1;
  CallbackObserver original_observer;
  AddWatchedProcess(kPid, original_observer.exited_callback_);

  CallbackObserver new_observer;
  EXPECT_CALL(original_observer, OnProcessExited(_)).Times(0);
  EXPECT_TRUE(process_manager_->UpdateExitCallback(
      kPid, new_observer.exited_callback_));
  EXPECT_CALL(new_observer, OnProcessExited(_)).Times(1);
  OnProcessExited(kPid, kExitStatus);
}

}  // namespace shill