Revert of Remove NPAPI plugin from chromoting webapp.

remoting/host/plugin/host_plugin.cc

+// Copyright (c) 2012 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 <stdio.h>
+#include <string.h>
+
+#include <string>
+#include <vector>
+
+#include "base/at_exit.h"
+#include "base/basictypes.h"
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "base/strings/stringize_macros.h"
+#include "net/socket/ssl_server_socket.h"
+#include "remoting/base/plugin_thread_task_runner.h"
+#include "remoting/base/resources.h"
+#include "remoting/base/string_resources.h"
+#include "remoting/host/plugin/host_log_handler.h"
+#include "remoting/host/plugin/host_plugin_utils.h"
+#include "remoting/host/plugin/host_script_object.h"
+#if defined(OS_WIN)
+#include "ui/gfx/win/dpi.h"
+#endif
+#include "third_party/npapi/bindings/npapi.h"
+#include "third_party/npapi/bindings/npfunctions.h"
+#include "third_party/npapi/bindings/npruntime.h"
+#include "ui/base/l10n/l10n_util.h"
+
+// Symbol export is handled with a separate def file on Windows.
+#if defined (__GNUC__) && __GNUC__ >= 4
+#define EXPORT __attribute__((visibility("default")))
+#else
+#define EXPORT
+#endif
+
+#if defined(OS_WIN)
+// TODO(wez): libvpx expects these 64-bit division functions to be provided
+// by libgcc.a, which we aren't linked against.  These implementations can
+// be removed once we have native MSVC libvpx builds for Windows.
+extern "C" {
+
+int64_t __cdecl __divdi3(int64_t a, int64_t b) {
+  return a / b;
+}
+uint64_t __cdecl __udivdi3(uint64_t a, uint64_t b) {
+  return a / b;
+}
+
+}
+#endif
+
+using remoting::g_npnetscape_funcs;
+using remoting::HostLogHandler;
+using remoting::HostNPScriptObject;
+using remoting::StringFromNPIdentifier;
+
+namespace {
+
+bool g_initialized = false;
+
+base::AtExitManager* g_at_exit_manager = NULL;
+
+// The plugin name and description returned by GetValue().
+std::string* g_ui_name = NULL;
+std::string* g_ui_description = NULL;
+
+// NPAPI plugin implementation for remoting host.
+// Documentation for most of the calls in this class can be found here:
+// https://developer.mozilla.org/en/Gecko_Plugin_API_Reference/Scripting_plugins
+class HostNPPlugin : public remoting::PluginThreadTaskRunner::Delegate {
+ public:
+  // |mode| is the display mode of plug-in. Values:
+  // NP_EMBED: (1) Instance was created by an EMBED tag and shares the browser
+  //               window with other content.
+  // NP_FULL: (2) Instance was created by a separate file and is the primary
+  //              content in the window.
+  HostNPPlugin(NPP instance, uint16 mode)
+      : instance_(instance),
+        scriptable_object_(NULL) {
+    plugin_task_runner_ = new remoting::PluginThreadTaskRunner(this);
+    plugin_auto_task_runner_ =
+        new remoting::AutoThreadTaskRunner(
+            plugin_task_runner_,
+            base::Bind(&remoting::PluginThreadTaskRunner::Quit,
+                       plugin_task_runner_));
+  }
+
+  virtual ~HostNPPlugin() {
+    if (scriptable_object_) {
+      DCHECK_EQ(scriptable_object_->referenceCount, 1UL);
+      g_npnetscape_funcs->releaseobject(scriptable_object_);
+      scriptable_object_ = NULL;
+    }
+
+    // Process tasks on |plugin_task_runner_| until all references to
+    // |plugin_auto_task_runner_| have been dropped. This requires that the
+    // browser has dropped any script object references - see above.
+    plugin_auto_task_runner_ = NULL;
+    plugin_task_runner_->DetachAndRunShutdownLoop();
+  }
+
+  bool Init(int16 argc, char** argn, char** argv, NPSavedData* saved) {
+#if defined(OS_MACOSX)
+    // Use the modern CoreGraphics and Cocoa models when available, since
+    // QuickDraw and Carbon are deprecated.
+    // The drawing and event models don't change anything for this plugin, since
+    // none of the functions affected by the models actually do anything.
+    // This does however keep the plugin from breaking when Chromium eventually
+    // drops support for QuickDraw and Carbon, and it also keeps the browser
+    // from sending Null Events once a second to support old Carbon based
+    // timers.
+    // Chromium should always be supporting the newer models.
+
+    // Sanity check to see if Chromium supports the CoreGraphics drawing model.
+    NPBool supports_core_graphics = false;
+    NPError err = g_npnetscape_funcs->getvalue(instance_,
+                                               NPNVsupportsCoreGraphicsBool,
+                                               &supports_core_graphics);
+    if (err == NPERR_NO_ERROR && supports_core_graphics) {
+      // Switch to CoreGraphics drawing model.
+      g_npnetscape_funcs->setvalue(instance_, NPPVpluginDrawingModel,
+          reinterpret_cast<void*>(NPDrawingModelCoreGraphics));
+    } else {
+      LOG(ERROR) << "No Core Graphics support";
+      return false;
+    }
+
+    // Sanity check to see if Chromium supports the Cocoa event model.
+    NPBool supports_cocoa = false;
+    err = g_npnetscape_funcs->getvalue(instance_, NPNVsupportsCocoaBool,
+                                       &supports_cocoa);
+    if (err == NPERR_NO_ERROR && supports_cocoa) {
+      // Switch to Cocoa event model.
+      g_npnetscape_funcs->setvalue(instance_, NPPVpluginEventModel,
+          reinterpret_cast<void*>(NPEventModelCocoa));
+    } else {
+      LOG(ERROR) << "No Cocoa Event Model support";
+      return false;
+    }
+#endif  // OS_MACOSX
+    net::EnableSSLServerSockets();
+    return true;
+  }
+
+  bool Save(NPSavedData** saved) {
+    return true;
+  }
+
+  NPObject* GetScriptableObject() {
+    if (!scriptable_object_) {
+      // Must be static. If it is a temporary, objects created by this
+      // method will fail in weird and wonderful ways later.
+      static NPClass npc_ref_object = {
+        NP_CLASS_STRUCT_VERSION,
+        &Allocate,
+        &Deallocate,
+        &Invalidate,
+        &HasMethod,
+        &Invoke,
+        &InvokeDefault,
+        &HasProperty,
+        &GetProperty,
+        &SetProperty,
+        &RemoveProperty,
+        &Enumerate,
+        NULL
+      };
+      scriptable_object_ = g_npnetscape_funcs->createobject(instance_,
+                                                            &npc_ref_object);
+    }
+    return scriptable_object_;
+  }
+
+  // PluginThreadTaskRunner::Delegate implementation.
+  virtual bool RunOnPluginThread(
+      base::TimeDelta delay, void(function)(void*), void* data) OVERRIDE {
+    if (delay == base::TimeDelta()) {
+      g_npnetscape_funcs->pluginthreadasynccall(instance_, function, data);
+    } else {
+      base::AutoLock auto_lock(timers_lock_);
+      uint32_t timer_id = g_npnetscape_funcs->scheduletimer(
+          instance_, delay.InMilliseconds(), false, &NPDelayedTaskSpringboard);
+      DelayedTask task = {function, data};
+      timers_[timer_id] = task;
+    }
+    return true;
+  }
+
+  void SetWindow(NPWindow* np_window) {
+    if (scriptable_object_) {
+      ScriptableFromObject(scriptable_object_)->SetWindow(np_window);
+    }
+  }
+
+  static void NPDelayedTaskSpringboard(NPP npp, uint32_t timer_id) {
+    HostNPPlugin* self = reinterpret_cast<HostNPPlugin*>(npp->pdata);
+    DelayedTask task;
+    {
+      base::AutoLock auto_lock(self->timers_lock_);
+      std::map<uint32_t, DelayedTask>::iterator it =
+          self->timers_.find(timer_id);
+      CHECK(it != self->timers_.end());
+      task = it->second;
+      self->timers_.erase(it);
+    }
+    task.function(task.data);
+  }
+
+ private:
+  struct ScriptableNPObject : public NPObject {
+    HostNPScriptObject* scriptable_object;
+  };
+
+  struct DelayedTask {
+    void (*function)(void*);
+    void* data;
+  };
+
+  static HostNPScriptObject* ScriptableFromObject(NPObject* obj) {
+    return reinterpret_cast<ScriptableNPObject*>(obj)->scriptable_object;
+  }
+
+  static NPObject* Allocate(NPP npp, NPClass* aClass) {
+    VLOG(2) << "static Allocate";
+    ScriptableNPObject* object =
+        reinterpret_cast<ScriptableNPObject*>(
+            g_npnetscape_funcs->memalloc(sizeof(ScriptableNPObject)));
+    HostNPPlugin* plugin = reinterpret_cast<HostNPPlugin*>(npp->pdata);
+
+    object->_class = aClass;
+    object->referenceCount = 1;
+    object->scriptable_object =
+        new HostNPScriptObject(npp, object, plugin->plugin_auto_task_runner_);
+    return object;
+  }
+
+  static void Deallocate(NPObject* npobj) {
+    VLOG(2) << "static Deallocate";
+    if (npobj) {
+      Invalidate(npobj);
+      g_npnetscape_funcs->memfree(npobj);
+    }
+  }
+
+  static void Invalidate(NPObject* npobj) {
+    if (npobj) {
+      ScriptableNPObject* object = reinterpret_cast<ScriptableNPObject*>(npobj);
+      if (object->scriptable_object) {
+        delete object->scriptable_object;
+        object->scriptable_object = NULL;
+      }
+    }
+  }
+
+  static bool HasMethod(NPObject* obj, NPIdentifier method_name) {
+    VLOG(2) << "static HasMethod";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::string method_name_string = StringFromNPIdentifier(method_name);
+    if (method_name_string.empty())
+      return false;
+    return scriptable->HasMethod(method_name_string);
+  }
+
+  static bool InvokeDefault(NPObject* obj,
+                            const NPVariant* args,
+                            uint32_t argCount,
+                            NPVariant* result) {
+    VLOG(2) << "static InvokeDefault";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    return scriptable->InvokeDefault(args, argCount, result);
+  }
+
+  static bool Invoke(NPObject* obj,
+                     NPIdentifier method_name,
+                     const NPVariant* args,
+                     uint32_t argCount,
+                     NPVariant* result) {
+    VLOG(2) << "static Invoke";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable)
+      return false;
+    std::string method_name_string = StringFromNPIdentifier(method_name);
+    if (method_name_string.empty())
+      return false;
+    return scriptable->Invoke(method_name_string, args, argCount, result);
+  }
+
+  static bool HasProperty(NPObject* obj, NPIdentifier property_name) {
+    VLOG(2) << "static HasProperty";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::string property_name_string = StringFromNPIdentifier(property_name);
+    if (property_name_string.empty())
+      return false;
+    return scriptable->HasProperty(property_name_string);
+  }
+
+  static bool GetProperty(NPObject* obj,
+                          NPIdentifier property_name,
+                          NPVariant* result) {
+    VLOG(2) << "static GetProperty";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::string property_name_string = StringFromNPIdentifier(property_name);
+    if (property_name_string.empty())
+      return false;
+    return scriptable->GetProperty(property_name_string, result);
+  }
+
+  static bool SetProperty(NPObject* obj,
+                          NPIdentifier property_name,
+                          const NPVariant* value) {
+    VLOG(2) << "static SetProperty";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::string property_name_string = StringFromNPIdentifier(property_name);
+    if (property_name_string.empty())
+      return false;
+    return scriptable->SetProperty(property_name_string, value);
+  }
+
+  static bool RemoveProperty(NPObject* obj, NPIdentifier property_name) {
+    VLOG(2) << "static RemoveProperty";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::string property_name_string = StringFromNPIdentifier(property_name);
+    if (property_name_string.empty())
+      return false;
+    return scriptable->RemoveProperty(property_name_string);
+  }
+
+  static bool Enumerate(NPObject* obj,
+                        NPIdentifier** value,
+                        uint32_t* count) {
+    VLOG(2) << "static Enumerate";
+    HostNPScriptObject* scriptable = ScriptableFromObject(obj);
+    if (!scriptable) return false;
+    std::vector<std::string> values;
+    bool is_good = scriptable->Enumerate(&values);
+    if (is_good) {
+      *count = values.size();
+      *value = reinterpret_cast<NPIdentifier*>(
+          g_npnetscape_funcs->memalloc(sizeof(NPIdentifier) * (*count)));
+      for (uint32_t i = 0; i < *count; ++i) {
+        (*value)[i] =
+            g_npnetscape_funcs->getstringidentifier(values[i].c_str());
+      }
+    }
+    return is_good;
+  }
+
+  NPP instance_;
+  NPObject* scriptable_object_;
+
+  scoped_refptr<remoting::PluginThreadTaskRunner> plugin_task_runner_;
+  scoped_refptr<remoting::AutoThreadTaskRunner> plugin_auto_task_runner_;
+
+  std::map<uint32_t, DelayedTask> timers_;
+  base::Lock timers_lock_;
+};
+
+void InitializePlugin() {
+  if (g_initialized)
+    return;
+
+  g_initialized = true;
+  g_at_exit_manager = new base::AtExitManager;
+
+  // Init an empty command line for common objects that use it.
+  base::CommandLine::Init(0, NULL);
+
+  if (remoting::LoadResources("")) {
+    g_ui_name = new std::string(
+        l10n_util::GetStringUTF8(IDS_REMOTING_HOST_PLUGIN_NAME));
+    g_ui_description = new std::string(
+        l10n_util::GetStringUTF8(IDS_REMOTING_HOST_PLUGIN_DESCRIPTION));
+  } else {
+    g_ui_name = new std::string();
+    g_ui_description = new std::string();
+  }
+}
+
+void ShutdownPlugin() {
+  delete g_ui_name;
+  delete g_ui_description;
+
+  remoting::UnloadResources();
+
+  delete g_at_exit_manager;
+}
+
+// Utility functions to map NPAPI Entry Points to C++ Objects.
+HostNPPlugin* PluginFromInstance(NPP instance) {
+  return reinterpret_cast<HostNPPlugin*>(instance->pdata);
+}
+
+NPError CreatePlugin(NPMIMEType pluginType,
+                     NPP instance,
+                     uint16 mode,
+                     int16 argc,
+                     char** argn,
+                     char** argv,
+                     NPSavedData* saved) {
+  VLOG(2) << "CreatePlugin";
+
+  // Register a global log handler.
+  // The LogMessage registration code is not thread-safe, so we need to perform
+  // this while we're running in a single thread.
+  HostLogHandler::RegisterLogMessageHandler();
+
+  HostNPPlugin* plugin = new HostNPPlugin(instance, mode);
+  instance->pdata = plugin;
+  if (!plugin->Init(argc, argn, argv, saved)) {
+    delete plugin;
+    instance->pdata = NULL;
+    return NPERR_INVALID_PLUGIN_ERROR;
+  } else {
+    return NPERR_NO_ERROR;
+  }
+}
+
+NPError DestroyPlugin(NPP instance,
+                      NPSavedData** save) {
+  VLOG(2) << "DestroyPlugin";
+
+  // Normally, we would unregister the global log handler that we registered
+  // in CreatePlugin. However, the LogHandler registration code is not thread-
+  // safe so we could crash if we update (register or unregister) the
+  // LogHandler while it's being read on another thread.
+  // At this point, all our threads should be shutdown, but it's safer to leave
+  // the handler registered until we're completely destroyed.
+
+  HostNPPlugin* plugin = PluginFromInstance(instance);
+  if (plugin) {
+    plugin->Save(save);
+    delete plugin;
+    instance->pdata = NULL;
+    return NPERR_NO_ERROR;
+  } else {
+    return NPERR_INVALID_PLUGIN_ERROR;
+  }
+}
+
+NPError GetValue(NPP instance, NPPVariable variable, void* value) {
+  // NP_GetValue() can be called before NP_Initialize().
+  InitializePlugin();
+
+  switch (variable) {
+  default:
+    VLOG(2) << "GetValue - default " << variable;
+    return NPERR_GENERIC_ERROR;
+  case NPPVpluginNameString:
+    VLOG(2) << "GetValue - name string";
+    *reinterpret_cast<const char**>(value) = g_ui_name->c_str();
+    break;
+  case NPPVpluginDescriptionString:
+    VLOG(2) << "GetValue - description string";
+    *reinterpret_cast<const char**>(value) = g_ui_description->c_str();
+    break;
+  case NPPVpluginNeedsXEmbed:
+    VLOG(2) << "GetValue - NeedsXEmbed";
+    *(static_cast<NPBool*>(value)) = true;
+    break;
+  case NPPVpluginScriptableNPObject:
+    VLOG(2) << "GetValue - scriptable object";
+    HostNPPlugin* plugin = PluginFromInstance(instance);
+    if (!plugin)
+      return NPERR_INVALID_PLUGIN_ERROR;
+    NPObject* scriptable_object = plugin->GetScriptableObject();
+    g_npnetscape_funcs->retainobject(scriptable_object);
+    *reinterpret_cast<NPObject**>(value) = scriptable_object;
+    break;
+  }
+  return NPERR_NO_ERROR;
+}
+
+NPError HandleEvent(NPP instance, void* ev) {
+  VLOG(2) << "HandleEvent";
+  return NPERR_NO_ERROR;
+}
+
+NPError SetWindow(NPP instance, NPWindow* pNPWindow) {
+  VLOG(2) << "SetWindow";
+  HostNPPlugin* plugin = PluginFromInstance(instance);
+  if (plugin) {
+    plugin->SetWindow(pNPWindow);
+  }
+  return NPERR_NO_ERROR;
+}
+
+}  // namespace
+
+#if defined(OS_WIN)
+BOOL APIENTRY DllMain(HMODULE hModule, DWORD dwReason, LPVOID lpReserved) {
+  switch (dwReason) {
+    case DLL_PROCESS_ATTACH:
+      DisableThreadLibraryCalls(hModule);
+      break;
+    case DLL_PROCESS_DETACH:
+    case DLL_THREAD_ATTACH:
+    case DLL_THREAD_DETACH:
+      break;
+  }
+  return TRUE;
+}
+#endif
+
+// The actual required NPAPI Entry points
+
+extern "C" {
+
+EXPORT NPError API_CALL NP_GetEntryPoints(NPPluginFuncs* nppfuncs) {
+  VLOG(2) << "NP_GetEntryPoints";
+  nppfuncs->version = (NP_VERSION_MAJOR << 8) | NP_VERSION_MINOR;
+  nppfuncs->newp = &CreatePlugin;
+  nppfuncs->destroy = &DestroyPlugin;
+  nppfuncs->getvalue = &GetValue;
+  nppfuncs->event = &HandleEvent;
+  nppfuncs->setwindow = &SetWindow;
+
+  return NPERR_NO_ERROR;
+}
+
+EXPORT NPError API_CALL NP_Initialize(NPNetscapeFuncs* npnetscape_funcs
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+                            , NPPluginFuncs* nppfuncs
+#endif
+                            ) {
+  VLOG(2) << "NP_Initialize";
+  InitializePlugin();
+
+  if (npnetscape_funcs == NULL)
+    return NPERR_INVALID_FUNCTABLE_ERROR;
+
+  if (((npnetscape_funcs->version & 0xff00) >> 8) > NP_VERSION_MAJOR)
+    return NPERR_INCOMPATIBLE_VERSION_ERROR;
+
+  g_npnetscape_funcs = npnetscape_funcs;
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  NP_GetEntryPoints(nppfuncs);
+#endif
+
+#if defined(OS_WIN)
+  gfx::EnableHighDPISupport();
+#endif
+
+  return NPERR_NO_ERROR;
+}
+
+EXPORT NPError API_CALL NP_Shutdown() {
+  VLOG(2) << "NP_Shutdown";
+  ShutdownPlugin();
+
+  return NPERR_NO_ERROR;
+}
+
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+EXPORT const char* API_CALL NP_GetMIMEDescription(void) {
+  VLOG(2) << "NP_GetMIMEDescription";
+  return STRINGIZE(HOST_PLUGIN_MIME_TYPE) "::";
+}
+
+EXPORT NPError API_CALL NP_GetValue(void* npp,
+                                    NPPVariable variable,
+                                    void* value) {
+  return GetValue((NPP)npp, variable, value);
+}
+#endif
+
+}  // extern "C"