// 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 "content/app/content_main.h"

#include "base/at_exit.h"
#include "base/base_switches.h"
#include "base/command_line.h"
#include "base/debug/debugger.h"
#include "base/i18n/icu_util.h"
#include "base/logging.h"
#include "base/mac/scoped_nsautorelease_pool.h"
#include "base/memory/scoped_ptr.h"
#include "base/process_util.h"
#include "base/stringprintf.h"
#include "content/app/content_main_delegate.h"
#include "content/common/content_paths.h"
#include "content/common/content_switches.h"
#include "content/common/main_function_params.h"
#include "content/common/sandbox_init_wrapper.h"
#include "content/common/set_process_title.h"
#include "crypto/nss_util.h"
#include "ui/base/ui_base_switches.h"
#include "ui/base/ui_base_paths.h"

#if defined(OS_WIN)
#include <atlbase.h>
#include <atlapp.h>
#include <new.h>
#include <malloc.h>
#elif defined(OS_MACOSX)
#include "base/mach_ipc_mac.h"
#include "base/system_monitor/system_monitor.h"
#include "content/browser/mach_broker_mac.h"
#endif // OS_WIN

#if defined(OS_POSIX)
#include <signal.h>

#include "base/global_descriptors_posix.h"
#include "content/common/chrome_descriptors.h"

#if !defined(OS_MACOSX)
#include "content/common/zygote_fork_delegate_linux.h"
#endif

#endif  // OS_POSIX

#if !defined(OS_MACOSX) && defined(USE_TCMALLOC)
extern "C" {
int tc_set_new_mode(int mode);
}
#endif

extern int RendererMain(const MainFunctionParams&);
extern int GpuMain(const MainFunctionParams&);
extern int PluginMain(const MainFunctionParams&);
extern int PpapiPluginMain(const MainFunctionParams&);
extern int PpapiBrokerMain(const MainFunctionParams&);
extern int WorkerMain(const MainFunctionParams&);
extern int UtilityMain(const MainFunctionParams&);
#if defined(OS_POSIX) && !defined(OS_MACOSX)
extern int ZygoteMain(const MainFunctionParams&,
                      ZygoteForkDelegate* forkdelegate);
#endif

namespace {

#if defined(OS_WIN)

static CAppModule _Module;

#pragma optimize("", off)
// Handlers for invalid parameter and pure call. They generate a breakpoint to
// tell breakpad that it needs to dump the process.
void InvalidParameter(const wchar_t* expression, const wchar_t* function,
                      const wchar_t* file, unsigned int line,
                      uintptr_t reserved) {
  __debugbreak();
  _exit(1);
}

void PureCall() {
  __debugbreak();
  _exit(1);
}
#pragma optimize("", on)

// Register the invalid param handler and pure call handler to be able to
// notify breakpad when it happens.
void RegisterInvalidParamHandler() {
  _set_invalid_parameter_handler(InvalidParameter);
  _set_purecall_handler(PureCall);
  // Also enable the new handler for malloc() based failures.
  _set_new_mode(1);
}

#elif defined(OS_MACOSX)

// Completes the Mach IPC handshake by sending this process' task port to the
// parent process.  The parent is listening on the Mach port given by
// |GetMachPortName()|.  The task port is used by the parent to get CPU/memory
// stats to display in the task manager.
void SendTaskPortToParentProcess() {
  const mach_msg_timeout_t kTimeoutMs = 100;
  const int32_t kMessageId = 0;
  std::string mach_port_name = MachBroker::GetMachPortName();

  base::MachSendMessage child_message(kMessageId);
  if (!child_message.AddDescriptor(mach_task_self())) {
    LOG(ERROR) << "child AddDescriptor(mach_task_self()) failed.";
    return;
  }

  base::MachPortSender child_sender(mach_port_name.c_str());
  kern_return_t err = child_sender.SendMessage(child_message, kTimeoutMs);
  if (err != KERN_SUCCESS) {
    LOG(ERROR) << StringPrintf("child SendMessage() failed: 0x%x %s", err,
                               mach_error_string(err));
  }
}

#endif  // defined(OS_WIN)

#if defined(OS_POSIX)

// Setup signal-handling state: resanitize most signals, ignore SIGPIPE.
void SetupSignalHandlers() {
  // Sanitise our signal handling state. Signals that were ignored by our
  // parent will also be ignored by us. We also inherit our parent's sigmask.
  sigset_t empty_signal_set;
  CHECK(0 == sigemptyset(&empty_signal_set));
  CHECK(0 == sigprocmask(SIG_SETMASK, &empty_signal_set, NULL));

  struct sigaction sigact;
  memset(&sigact, 0, sizeof(sigact));
  sigact.sa_handler = SIG_DFL;
  static const int signals_to_reset[] =
      {SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGABRT, SIGFPE, SIGSEGV,
       SIGALRM, SIGTERM, SIGCHLD, SIGBUS, SIGTRAP};  // SIGPIPE is set below.
  for (unsigned i = 0; i < arraysize(signals_to_reset); i++) {
    CHECK(0 == sigaction(signals_to_reset[i], &sigact, NULL));
  }

  // Always ignore SIGPIPE.  We check the return value of write().
  CHECK(signal(SIGPIPE, SIG_IGN) != SIG_ERR);
}

#endif  // OS_POSIX

void SetupCRT(const CommandLine& command_line) {
#if defined(OS_WIN)
#if defined(_CRTDBG_MAP_ALLOC)
  _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDERR);
  _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
#else
  if (!command_line.HasSwitch(switches::kDisableBreakpad)) {
    _CrtSetReportMode(_CRT_ASSERT, 0);
  }
#endif
#endif
}

void CommonSubprocessInit(const std::string& process_type) {
#if defined(OS_WIN)
  // HACK: Let Windows know that we have started.  This is needed to suppress
  // the IDC_APPSTARTING cursor from being displayed for a prolonged period
  // while a subprocess is starting.
  PostThreadMessage(GetCurrentThreadId(), WM_NULL, 0, 0);
  MSG msg;
  PeekMessage(&msg, NULL, 0, 0, PM_REMOVE);
#endif
#if defined(OS_POSIX) && !defined(OS_MACOSX)
  // Various things break when you're using a locale where the decimal
  // separator isn't a period.  See e.g. bugs 22782 and 39964.  For
  // all processes except the browser process (where we call system
  // APIs that may rely on the correct locale for formatting numbers
  // when presenting them to the user), reset the locale for numeric
  // formatting.
  // Note that this is not correct for plugin processes -- they can
  // surface UI -- but it's likely they get this wrong too so why not.
  setlocale(LC_NUMERIC, "C");
#endif
}

// We dispatch to a process-type-specific FooMain() based on a command-line
// flag.  This struct is used to build a table of (flag, main function) pairs.
struct MainFunction {
  const char* name;
  int (*function)(const MainFunctionParams&);
};

#if defined(OS_POSIX) && !defined(OS_MACOSX)
// On platforms that use the zygote, we have a special subset of
// subprocesses that are launched via the zygote.  This function
// fills in some process-launching bits around ZygoteMain().
// Returns the exit code of the subprocess.
int RunZygote(const MainFunctionParams& main_function_params,
              content::ContentMainDelegate* delegate) {
  static const MainFunction kMainFunctions[] = {
    { switches::kRendererProcess,    RendererMain },
    { switches::kWorkerProcess,      WorkerMain },
    { switches::kPpapiPluginProcess, PpapiPluginMain },
  };

  scoped_ptr<ZygoteForkDelegate> zygote_fork_delegate;
  if (delegate) zygote_fork_delegate.reset(delegate->ZygoteStarting());

  // This function call can return multiple times, once per fork().
  if (!ZygoteMain(main_function_params, zygote_fork_delegate.get()))
    return 1;

  if (delegate) delegate->ZygoteForked();

  // Zygote::HandleForkRequest may have reallocated the command
  // line so update it here with the new version.
  const CommandLine& command_line = *CommandLine::ForCurrentProcess();

  MainFunctionParams main_params(command_line,
                                 main_function_params.sandbox_info_,
                                 main_function_params.autorelease_pool_);
  // Get the new process type from the new command line.
  std::string process_type =
      command_line.GetSwitchValueASCII(switches::kProcessType);

  for (size_t i = 0; i < arraysize(kMainFunctions); ++i) {
    if (process_type == kMainFunctions[i].name)
      return kMainFunctions[i].function(main_params);
  }

  if (delegate)
    return delegate->RunProcess(process_type, main_function_params);

  NOTREACHED() << "Unknown zygote process type: " << process_type;
  return 1;
}
#endif  // defined(OS_POSIX) && !defined(OS_MACOSX)

// Run the FooMain() for a given process type.
// If |process_type| is empty, runs BrowserMain().
// Returns the exit code for this process.
int RunNamedProcessTypeMain(const std::string& process_type,
                            const MainFunctionParams& main_function_params,
                            content::ContentMainDelegate* delegate) {
  static const MainFunction kMainFunctions[] = {
    { switches::kRendererProcess,    RendererMain },
    { switches::kPluginProcess,      PluginMain },
    { switches::kWorkerProcess,      WorkerMain },
    { switches::kPpapiPluginProcess, PpapiPluginMain },
    { switches::kPpapiBrokerProcess, PpapiBrokerMain },
    { switches::kUtilityProcess,     UtilityMain },
    { switches::kGpuProcess,         GpuMain },
  };

  for (size_t i = 0; i < arraysize(kMainFunctions); ++i) {
    if (process_type == kMainFunctions[i].name)
      return kMainFunctions[i].function(main_function_params);
  }

#if defined(OS_POSIX) && !defined(OS_MACOSX)
  // Zygote startup is special -- see RunZygote comments above
  // for why we don't use ZygoteMain directly.
  if (process_type == switches::kZygoteProcess)
    return RunZygote(main_function_params, delegate);
#endif

  // If it's a process we don't know about, the embedder should know.
  if (delegate)
    return delegate->RunProcess(process_type, main_function_params);

  NOTREACHED() << "Unknown process type: " << process_type;
  return 1;
}

}  // namespace

namespace content {

#if defined(OS_WIN)
int ContentMain(HINSTANCE instance,
                sandbox::SandboxInterfaceInfo* sandbox_info,
                ContentMainDelegate* delegate) {
  // argc/argv are ignored on Windows; see command_line.h for details.
  int argc = 0;
  char** argv = NULL;

  RegisterInvalidParamHandler();
  _Module.Init(NULL, static_cast<HINSTANCE>(instance));
#else
int ContentMain(int argc,
                char** argv,
                ContentMainDelegate* delegate) {
  // NOTE(willchan): One might ask why this call is done here rather than in
  // process_util_linux.cc with the definition of
  // EnableTerminationOnOutOfMemory().  That's because base shouldn't have a
  // dependency on TCMalloc.  Really, we ought to have our allocator shim code
  // implement this EnableTerminationOnOutOfMemory() function.  Whateverz.  This
  // works for now.
#if !defined(OS_MACOSX) && defined(USE_TCMALLOC)
  // For tcmalloc, we need to tell it to behave like new.
  tc_set_new_mode(1);
#endif

  // Set C library locale to make sure CommandLine can parse argument values
  // in correct encoding.
  setlocale(LC_ALL, "");

  SetupSignalHandlers();

  base::GlobalDescriptors* g_fds = base::GlobalDescriptors::GetInstance();
  g_fds->Set(kPrimaryIPCChannel,
             kPrimaryIPCChannel + base::GlobalDescriptors::kBaseDescriptor);
#if defined(OS_LINUX)
  g_fds->Set(kCrashDumpSignal,
             kCrashDumpSignal + base::GlobalDescriptors::kBaseDescriptor);
#endif

#endif  // OS_WIN

  base::EnableTerminationOnHeapCorruption();
  base::EnableTerminationOnOutOfMemory();

  // The exit manager is in charge of calling the dtors of singleton objects.
  base::AtExitManager exit_manager;

  // We need this pool for all the objects created before we get to the
  // event loop, but we don't want to leave them hanging around until the
  // app quits. Each "main" needs to flush this pool right before it goes into
  // its main event loop to get rid of the cruft.
  base::mac::ScopedNSAutoreleasePool autorelease_pool;

  CommandLine::Init(argc, argv);

  int exit_code;
  if (delegate && delegate->BasicStartupComplete(&exit_code))
    return exit_code;

  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
  std::string process_type =
        command_line.GetSwitchValueASCII(switches::kProcessType);

#if defined(OS_MACOSX)
  // We need to allocate the IO Ports before the Sandbox is initialized or
  // the first instance of SystemMonitor is created.
  // It's important not to allocate the ports for processes which don't register
  // with the system monitor - see crbug.com/88867.
  if (process_type.empty() ||
      process_type == switches::kPluginProcess ||
      process_type == switches::kRendererProcess ||
      process_type == switches::kUtilityProcess ||
      process_type == switches::kWorkerProcess ||
      (delegate && delegate->ProcessRegistersWithSystemProcess(process_type))) {
    base::SystemMonitor::AllocateSystemIOPorts();
  }

  if (!process_type.empty() &&
      (!delegate || delegate->ShouldSendMachPort(process_type))) {
    SendTaskPortToParentProcess();
  }
#endif

#if defined(OS_POSIX)
  if (!process_type.empty()) {
    // When you hit Ctrl-C in a terminal running the browser
    // process, a SIGINT is delivered to the entire process group.
    // When debugging the browser process via gdb, gdb catches the
    // SIGINT for the browser process (and dumps you back to the gdb
    // console) but doesn't for the child processes, killing them.
    // The fix is to have child processes ignore SIGINT; they'll die
    // on their own when the browser process goes away.
    //
    // Note that we *can't* rely on BeingDebugged to catch this case because we
    // are the child process, which is not being debugged.
    // TODO(evanm): move this to some shared subprocess-init function.
    if (!base::debug::BeingDebugged())
      signal(SIGINT, SIG_IGN);
  }
#endif

  SetupCRT(command_line);

#if defined(USE_NSS)
  crypto::EarlySetupForNSSInit();
#endif

  ui::RegisterPathProvider();
  content::RegisterPathProvider();

  CHECK(icu_util::Initialize());

  if (delegate) delegate->PreSandboxStartup();

  if (!process_type.empty())
    CommonSubprocessInit(process_type);

  // Initialize the sandbox for this process.
  SandboxInitWrapper sandbox_wrapper;
  bool initialize_sandbox = true;

#if defined(OS_WIN)
  sandbox_wrapper.SetServices(sandbox_info);
#elif defined(OS_MACOSX)
  // On OS X the renderer sandbox needs to be initialized later in the startup
  // sequence in RendererMainPlatformDelegate::EnableSandbox().
  if (process_type == switches::kRendererProcess ||
      process_type == switches::kPpapiPluginProcess ||
      (delegate && delegate->DelaySandboxInitialization(process_type))) {
    initialize_sandbox = false;
  }
#endif

  if (initialize_sandbox) {
    bool sandbox_initialized_ok =
        sandbox_wrapper.InitializeSandbox(command_line, process_type);
    // Die if the sandbox can't be enabled.
    CHECK(sandbox_initialized_ok) << "Error initializing sandbox for "
                                  << process_type;
  }

  if (delegate) delegate->SandboxInitialized(process_type);

#if defined(OS_POSIX)
  SetProcessTitleFromCommandLine(argv);
#endif

  MainFunctionParams main_params(command_line, sandbox_wrapper,
                                 &autorelease_pool);

  exit_code = RunNamedProcessTypeMain(process_type, main_params, delegate);

  if (delegate) delegate->ProcessExiting(process_type);

#if defined(OS_WIN)
#ifdef _CRTDBG_MAP_ALLOC
  _CrtDumpMemoryLeaks();
#endif  // _CRTDBG_MAP_ALLOC

  _Module.Term();
#endif  // OS_WIN

  return exit_code;
}

}  // namespace content