content/child/npapi/np_channel_base.h

   1 // Copyright 2013 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 CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_
   6 #define CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/containers/hash_tables.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/process/process.h"
  15 #include "content/child/npapi/npobject_base.h"
  16 #include "content/common/message_router.h"
  17 #include "ipc/ipc_channel_handle.h"
  18 #include "ipc/ipc_sync_channel.h"
  19
  20 namespace base {
  21 class SingleThreadTaskRunner;
  22 }
  23
  24 namespace content {
  25
  26 // Encapsulates an IPC channel between a renderer and another process. Used to
  27 // proxy access to NP objects.
  28 class NPChannelBase : public IPC::Listener,
  29                       public IPC::Sender,
  30                       public base::RefCountedThreadSafe<NPChannelBase> {
  31  public:
  32
  33   // WebPlugin[Delegate] call these on construction and destruction to setup
  34   // the routing and manage lifetime of this object (they pass NULL for
  35   // npobject). These are also called by NPObjectProxy and NPObjectStub (which
  36   // pass themselves for npobject).  However the latter don't control the
  37   // lifetime of this object because we don't want a leak of an NPObject to
  38   // keep the channel around longer than necessary.
  39   void AddRoute(int route_id, IPC::Listener* listener, NPObjectBase* npobject);
  40   void RemoveRoute(int route_id);
  41
  42   void AddMappingForNPObjectProxy(int route_id, NPObject* object);
  43   void RemoveMappingForNPObjectProxy(int route_id);
  44
  45   void AddMappingForNPObjectStub(int route_id, NPObject* object);
  46   void RemoveMappingForNPObjectStub(int route_id, NPObject* object);
  47
  48   void AddMappingForNPObjectOwner(int route_id, struct _NPP* owner);
  49   void SetDefaultNPObjectOwner(struct _NPP* owner);
  50   void RemoveMappingForNPObjectOwner(int route_id);
  51
  52   NPObject* GetExistingNPObjectProxy(int route_id);
  53   int GetExistingRouteForNPObjectStub(NPObject* npobject);
  54   struct _NPP* GetExistingNPObjectOwner(int route_id);
  55   int GetExistingRouteForNPObjectOwner(struct _NPP* owner);
  56
  57   // IPC::Sender implementation:
  58   bool Send(IPC::Message* msg) override;
  59
  60   base::ProcessId peer_pid() { return channel_->GetPeerPID(); }
  61   IPC::ChannelHandle channel_handle() const { return channel_handle_; }
  62
  63   // Returns the number of open NPObject channels in this process.
  64   static int Count();
  65
  66   // Returns a new route id.
  67   virtual int GenerateRouteID() = 0;
  68
  69   // Returns whether the channel is valid or not. A channel is invalid
  70   // if it is disconnected due to a channel error.
  71   bool channel_valid() {
  72     return channel_valid_;
  73   }
  74
  75   // Returns the most recent NPChannelBase to have received a message
  76   // in this process.
  77   static NPChannelBase* GetCurrentChannel();
  78
  79   static void CleanupChannels();
  80
  81   // Returns the NPObjectBase object for the route id passed in.
  82   // Returns NULL on failure.
  83   NPObjectBase* GetNPObjectListenerForRoute(int route_id);
  84
  85   // Returns the event that's set when a call to the renderer causes a modal
  86   // dialog to come up. The default implementation returns NULL. Derived
  87   // classes should override this method if this functionality is required.
  88   virtual base::WaitableEvent* GetModalDialogEvent(int render_view_id);
  89
  90  protected:
  91   typedef NPChannelBase* (*ChannelFactory)();
  92
  93   friend class base::RefCountedThreadSafe<NPChannelBase>;
  94
  95   ~NPChannelBase() override;
  96
  97   // Returns a NPChannelBase derived object for the given channel name.
  98   // If an existing channel exists returns that object, otherwise creates a
  99   // new one.  Even though on creation the object is refcounted, each caller
 100   // must still ref count the returned value.  When there are no more routes
 101   // on the channel and its ref count is 0, the object deletes itself.
 102   static NPChannelBase* GetChannel(
 103       const IPC::ChannelHandle& channel_handle,
 104       IPC::Channel::Mode mode,
 105       ChannelFactory factory,
 106       base::SingleThreadTaskRunner* ipc_task_runner,
 107       bool create_pipe_now,
 108       base::WaitableEvent* shutdown_event);
 109
 110   // Sends a message to all instances.
 111   static void Broadcast(IPC::Message* message);
 112
 113   // Called on the worker thread
 114   NPChannelBase();
 115
 116   virtual void CleanUp() { }
 117
 118   // Implemented by derived classes to handle control messages
 119   virtual bool OnControlMessageReceived(const IPC::Message& msg);
 120
 121   // IPC::Listener implementation:
 122   bool OnMessageReceived(const IPC::Message& msg) override;
 123   void OnChannelConnected(int32 peer_pid) override;
 124   void OnChannelError() override;
 125
 126   void set_send_unblocking_only_during_unblock_dispatch() {
 127     send_unblocking_only_during_unblock_dispatch_ = true;
 128   }
 129
 130   virtual bool Init(base::SingleThreadTaskRunner* ipc_task_runner,
 131                     bool create_pipe_now,
 132                     base::WaitableEvent* shutdown_event);
 133
 134   scoped_ptr<IPC::SyncChannel> channel_;
 135   IPC::ChannelHandle channel_handle_;
 136
 137  private:
 138   IPC::Channel::Mode mode_;
 139   // This tracks the number of routes registered without an NPObject. It's used
 140   // to manage the lifetime of this object. See comment for AddRoute() and
 141   // RemoveRoute().
 142   int non_npobject_count_;
 143   int peer_pid_;
 144
 145   // true when in the middle of a RemoveRoute call
 146   bool in_remove_route_;
 147
 148   // Keep track of all the registered NPObjects proxies/stubs so that when the
 149   // channel is closed we can inform them.
 150   typedef base::hash_map<int, NPObjectBase*> ListenerMap;
 151   ListenerMap npobject_listeners_;
 152
 153   typedef base::hash_map<int, NPObject*> ProxyMap;
 154   ProxyMap proxy_map_;
 155
 156   typedef base::hash_map<NPObject*, int> StubMap;
 157   StubMap stub_map_;
 158
 159   typedef base::hash_map<struct _NPP*, int> OwnerToRouteMap;
 160   OwnerToRouteMap owner_to_route_;
 161
 162   typedef base::hash_map<int, struct _NPP*> RouteToOwnerMap;
 163   RouteToOwnerMap route_to_owner_;
 164
 165   // Used on the plugin side to represent any object received that does
 166   // not belong to a plugin instance.
 167   struct _NPP* default_owner_;
 168
 169   // Used to implement message routing functionality to WebPlugin[Delegate]
 170   // objects
 171   MessageRouter router_;
 172
 173   // A channel is invalid if it is disconnected as a result of a channel
 174   // error. This flag is used to indicate the same.
 175   bool channel_valid_;
 176
 177   // Track whether we're dispatching a message with the unblock flag; works like
 178   // a refcount, 0 when we're not.
 179   int in_unblock_dispatch_;
 180
 181   // If true, sync messages will only be marked as unblocking if the channel is
 182   // in the middle of dispatching an unblocking message.  The non-renderer
 183   // process wants to avoid setting the unblock flag on its sync messages
 184   // unless necessary, since it can potentially introduce reentrancy into
 185   // WebKit in ways that it doesn't expect (i.e. causing layout during paint).
 186   // However to avoid deadlock, we must ensure that any message that's sent as
 187   // a result of a sync call from the renderer must unblock the renderer.  We
 188   // additionally have to do this for async messages from the renderer that
 189   // have the unblock flag set, since they could be followed by a sync message
 190   // that won't get dispatched until the call to the renderer is complete.
 191   bool send_unblocking_only_during_unblock_dispatch_;
 192
 193   DISALLOW_COPY_AND_ASSIGN(NPChannelBase);
 194 };
 195
 196 }  // namespace content
 197
 198 #endif  // CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_