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 IPC {
  25 class AttachmentBroker;
  26 }
  27
  28 namespace content {
  29
  30 // Encapsulates an IPC channel between a renderer and another process. Used to
  31 // proxy access to NP objects.
  32 class NPChannelBase : public IPC::Listener,
  33                       public IPC::Sender,
  34                       public base::RefCountedThreadSafe<NPChannelBase> {
  35  public:
  36
  37   // WebPlugin[Delegate] call these on construction and destruction to setup
  38   // the routing and manage lifetime of this object (they pass NULL for
  39   // npobject). These are also called by NPObjectProxy and NPObjectStub (which
  40   // pass themselves for npobject).  However the latter don't control the
  41   // lifetime of this object because we don't want a leak of an NPObject to
  42   // keep the channel around longer than necessary.
  43   void AddRoute(int route_id, IPC::Listener* listener, NPObjectBase* npobject);
  44   void RemoveRoute(int route_id);
  45
  46   void AddMappingForNPObjectProxy(int route_id, NPObject* object);
  47   void RemoveMappingForNPObjectProxy(int route_id);
  48
  49   void AddMappingForNPObjectStub(int route_id, NPObject* object);
  50   void RemoveMappingForNPObjectStub(int route_id, NPObject* object);
  51
  52   void AddMappingForNPObjectOwner(int route_id, struct _NPP* owner);
  53   void SetDefaultNPObjectOwner(struct _NPP* owner);
  54   void RemoveMappingForNPObjectOwner(int route_id);
  55
  56   NPObject* GetExistingNPObjectProxy(int route_id);
  57   int GetExistingRouteForNPObjectStub(NPObject* npobject);
  58   struct _NPP* GetExistingNPObjectOwner(int route_id);
  59   int GetExistingRouteForNPObjectOwner(struct _NPP* owner);
  60
  61   // IPC::Sender implementation:
  62   bool Send(IPC::Message* msg) override;
  63
  64   base::ProcessId peer_pid() { return channel_->GetPeerPID(); }
  65   IPC::ChannelHandle channel_handle() const { return channel_handle_; }
  66
  67   // Returns the number of open NPObject channels in this process.
  68   static int Count();
  69
  70   // Returns a new route id.
  71   virtual int GenerateRouteID() = 0;
  72
  73   // Returns whether the channel is valid or not. A channel is invalid
  74   // if it is disconnected due to a channel error.
  75   bool channel_valid() {
  76     return channel_valid_;
  77   }
  78
  79   // Returns the most recent NPChannelBase to have received a message
  80   // in this process.
  81   static NPChannelBase* GetCurrentChannel();
  82
  83   static void CleanupChannels();
  84
  85   // Returns the NPObjectBase object for the route id passed in.
  86   // Returns NULL on failure.
  87   NPObjectBase* GetNPObjectListenerForRoute(int route_id);
  88
  89   // Returns the event that's set when a call to the renderer causes a modal
  90   // dialog to come up. The default implementation returns NULL. Derived
  91   // classes should override this method if this functionality is required.
  92   virtual base::WaitableEvent* GetModalDialogEvent(int render_view_id);
  93
  94  protected:
  95   typedef NPChannelBase* (*ChannelFactory)();
  96
  97   friend class base::RefCountedThreadSafe<NPChannelBase>;
  98
  99   ~NPChannelBase() override;
 100
 101   // Returns a NPChannelBase derived object for the given channel name.
 102   // If an existing channel exists returns that object, otherwise creates a
 103   // new one.  Even though on creation the object is refcounted, each caller
 104   // must still ref count the returned value.  When there are no more routes
 105   // on the channel and its ref count is 0, the object deletes itself.
 106   static NPChannelBase* GetChannel(
 107       const IPC::ChannelHandle& channel_handle,
 108       IPC::Channel::Mode mode,
 109       ChannelFactory factory,
 110       base::SingleThreadTaskRunner* ipc_task_runner,
 111       bool create_pipe_now,
 112       base::WaitableEvent* shutdown_event,
 113       IPC::AttachmentBroker* broker);
 114
 115   // Sends a message to all instances.
 116   static void Broadcast(IPC::Message* message);
 117
 118   // Called on the worker thread
 119   NPChannelBase();
 120
 121   virtual void CleanUp() { }
 122
 123   // Implemented by derived classes to handle control messages
 124   virtual bool OnControlMessageReceived(const IPC::Message& msg);
 125
 126   // IPC::Listener implementation:
 127   bool OnMessageReceived(const IPC::Message& msg) override;
 128   void OnChannelConnected(int32 peer_pid) override;
 129   void OnChannelError() override;
 130
 131   void set_send_unblocking_only_during_unblock_dispatch() {
 132     send_unblocking_only_during_unblock_dispatch_ = true;
 133   }
 134
 135   virtual bool Init(base::SingleThreadTaskRunner* ipc_task_runner,
 136                     bool create_pipe_now,
 137                     base::WaitableEvent* shutdown_event,
 138                     IPC::AttachmentBroker* broker);
 139
 140   scoped_ptr<IPC::SyncChannel> channel_;
 141   IPC::ChannelHandle channel_handle_;
 142
 143  private:
 144   IPC::Channel::Mode mode_;
 145   // This tracks the number of routes registered without an NPObject. It's used
 146   // to manage the lifetime of this object. See comment for AddRoute() and
 147   // RemoveRoute().
 148   int non_npobject_count_;
 149   int peer_pid_;
 150
 151   // true when in the middle of a RemoveRoute call
 152   bool in_remove_route_;
 153
 154   // Keep track of all the registered NPObjects proxies/stubs so that when the
 155   // channel is closed we can inform them.
 156   typedef base::hash_map<int, NPObjectBase*> ListenerMap;
 157   ListenerMap npobject_listeners_;
 158
 159   typedef base::hash_map<int, NPObject*> ProxyMap;
 160   ProxyMap proxy_map_;
 161
 162   typedef base::hash_map<NPObject*, int> StubMap;
 163   StubMap stub_map_;
 164
 165   typedef base::hash_map<struct _NPP*, int> OwnerToRouteMap;
 166   OwnerToRouteMap owner_to_route_;
 167
 168   typedef base::hash_map<int, struct _NPP*> RouteToOwnerMap;
 169   RouteToOwnerMap route_to_owner_;
 170
 171   // Used on the plugin side to represent any object received that does
 172   // not belong to a plugin instance.
 173   struct _NPP* default_owner_;
 174
 175   // Used to implement message routing functionality to WebPlugin[Delegate]
 176   // objects
 177   MessageRouter router_;
 178
 179   // A channel is invalid if it is disconnected as a result of a channel
 180   // error. This flag is used to indicate the same.
 181   bool channel_valid_;
 182
 183   // Track whether we're dispatching a message with the unblock flag; works like
 184   // a refcount, 0 when we're not.
 185   int in_unblock_dispatch_;
 186
 187   // If true, sync messages will only be marked as unblocking if the channel is
 188   // in the middle of dispatching an unblocking message.  The non-renderer
 189   // process wants to avoid setting the unblock flag on its sync messages
 190   // unless necessary, since it can potentially introduce reentrancy into
 191   // WebKit in ways that it doesn't expect (i.e. causing layout during paint).
 192   // However to avoid deadlock, we must ensure that any message that's sent as
 193   // a result of a sync call from the renderer must unblock the renderer.  We
 194   // additionally have to do this for async messages from the renderer that
 195   // have the unblock flag set, since they could be followed by a sync message
 196   // that won't get dispatched until the call to the renderer is complete.
 197   bool send_unblocking_only_during_unblock_dispatch_;
 198
 199   DISALLOW_COPY_AND_ASSIGN(NPChannelBase);
 200 };
 201
 202 }  // namespace content
 203
 204 #endif  // CONTENT_CHILD_NPAPI_NP_CHANNEL_BASE_H_