ppapi/proxy/host_dispatcher.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef PPAPI_PROXY_HOST_DISPATCHER_H_
   6 #define PPAPI_PROXY_HOST_DISPATCHER_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "base/observer_list.h"
  15 #include "base/process/process.h"
  16 #include "ipc/message_filter.h"
  17 #include "ppapi/c/pp_instance.h"
  18 #include "ppapi/proxy/dispatcher.h"
  19
  20 struct PPB_Proxy_Private;
  21
  22 namespace ppapi {
  23
  24 struct Preferences;
  25
  26 namespace proxy {
  27
  28 class PPAPI_PROXY_EXPORT HostDispatcher : public Dispatcher {
  29  public:
  30   // This interface receives notifications about sync messages being sent by
  31   // the dispatcher to the plugin process. Some parts of Chrome may need to
  32   // know whether we are sending a synchronous message to the plugin; e.g. to
  33   // detect a hung plugin or to avoid re-entering JavaScript.
  34   //
  35   // Note that there can be nested sync messages, so the begin/end status
  36   // actually represents a stack of blocking messages.
  37   class SyncMessageStatusObserver {
  38    public:
  39     // Notification that a sync message is about to be sent out.
  40     virtual void BeginBlockOnSyncMessage() = 0;
  41
  42     // Notification that a sync message reply was received and the dispatcher
  43     // is no longer blocked on a sync message.
  44     virtual void EndBlockOnSyncMessage() = 0;
  45
  46    protected:
  47     virtual ~SyncMessageStatusObserver() {}
  48   };
  49
  50   // Constructor for the renderer side. This will take a reference to the
  51   // SyncMessageStatusReceiver.
  52   //
  53   // You must call InitHostWithChannel after the constructor.
  54   HostDispatcher(PP_Module module,
  55                  PP_GetInterface_Func local_get_interface,
  56                  const PpapiPermissions& permissions);
  57   ~HostDispatcher();
  58
  59   // You must call this function before anything else. Returns true on success.
  60   // The delegate pointer must outlive this class, ownership is not
  61   // transferred.
  62   virtual bool InitHostWithChannel(Delegate* delegate,
  63                                    base::ProcessId peer_pid,
  64                                    const IPC::ChannelHandle& channel_handle,
  65                                    bool is_client,
  66                                    const Preferences& preferences);
  67
  68   // The host side maintains a mapping from PP_Instance to Dispatcher so
  69   // that we can send the messages to the right channel.
  70   static HostDispatcher* GetForInstance(PP_Instance instance);
  71   static void SetForInstance(PP_Instance instance,
  72                              HostDispatcher* dispatcher);
  73   static void RemoveForInstance(PP_Instance instance);
  74
  75   // Returns the host's notion of our PP_Module. This will be different than
  76   // the plugin's notion of its PP_Module because the plugin process may be
  77   // used by multiple renderer processes.
  78   //
  79   // Use this value instead of a value from the plugin whenever talking to the
  80   // host.
  81   PP_Module pp_module() const { return pp_module_; }
  82
  83   // Dispatcher overrides.
  84   bool IsPlugin() const override;
  85   bool Send(IPC::Message* msg) override;
  86
  87   // IPC::Listener.
  88   bool OnMessageReceived(const IPC::Message& msg) override;
  89   void OnChannelError() override;
  90
  91   // Proxied version of calling GetInterface on the plugin. This will check
  92   // if the plugin supports the given interface (with caching) and returns the
  93   // pointer to the proxied interface if it is supported. Returns NULL if the
  94   // given interface isn't supported by the plugin or the proxy.
  95   const void* GetProxiedInterface(const std::string& iface_name);
  96
  97   // See the value below. Call this when processing a scripting message from
  98   // the plugin that can be reentered. This is set to false at the beginning
  99   // of processing of each message from the plugin.
 100   void set_allow_plugin_reentrancy() {
 101     allow_plugin_reentrancy_ = true;
 102   }
 103
 104   // Returns the proxy interface for talking to the implementation.
 105   const PPB_Proxy_Private* ppb_proxy() const { return ppb_proxy_; }
 106
 107   // Register an observer that will be invoked when the dispatcher begins
 108   // sending a sync message and finishes sending a sync message.
 109   // Returns a Closure that can be used to unregister the observer (the Closure
 110   // is bound to a weak pointer, so is safe to call even after the
 111   // HostDispatcher is gone.)
 112   base::Closure AddSyncMessageStatusObserver(SyncMessageStatusObserver* obs);
 113
 114   void AddFilter(IPC::Listener* listener);
 115
 116  protected:
 117   // Overridden from Dispatcher.
 118   void OnInvalidMessageReceived() override;
 119
 120  private:
 121   void OnHostMsgLogWithSource(PP_Instance instance,
 122                               int int_log_level,
 123                               const std::string& source,
 124                               const std::string& value);
 125
 126   void RemoveSyncMessageStatusObserver(SyncMessageStatusObserver* obs);
 127
 128   PP_Module pp_module_;
 129
 130   // Maps interface name to whether that interface is supported. If an interface
 131   // name is not in the map, that implies that we haven't queried for it yet.
 132   typedef base::hash_map<std::string, bool> PluginSupportedMap;
 133   PluginSupportedMap plugin_supported_;
 134
 135   // Guaranteed non-NULL.
 136   const PPB_Proxy_Private* ppb_proxy_;
 137
 138   // Set to true when the plugin is in a state that it can be reentered by a
 139   // sync message from the host. We allow reentrancy only when we're processing
 140   // a sync message from the renderer that is a scripting command. When the
 141   // plugin is in this state, it needs to accept reentrancy since scripting may
 142   // ultimately call back into the plugin.
 143   bool allow_plugin_reentrancy_;
 144
 145   base::ObserverList<SyncMessageStatusObserver> sync_status_observer_list_;
 146
 147   std::vector<IPC::Listener*> filters_;
 148
 149   base::WeakPtrFactory<HostDispatcher> weak_ptr_factory_;
 150
 151   DISALLOW_COPY_AND_ASSIGN(HostDispatcher);
 152 };
 153
 154 // Create this object on the stack to prevent the module (and hence the
 155 // dispatcher) from being deleted out from under you. This is necessary when
 156 // calling some scripting functions that may delete the plugin.
 157 //
 158 // This class does nothing if used on the plugin side.
 159 class ScopedModuleReference {
 160  public:
 161   explicit ScopedModuleReference(Dispatcher* dispatcher);
 162   ~ScopedModuleReference();
 163
 164  private:
 165   HostDispatcher* dispatcher_;
 166
 167   DISALLOW_COPY_AND_ASSIGN(ScopedModuleReference);
 168 };
 169
 170 }  // namespace proxy
 171 }  // namespace ppapi
 172
 173 #endif  // PPAPI_PROXY_HOST_DISPATCHER_H_