ppapi/proxy/proxy_channel.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_PROXY_CHANNEL_H_
   6 #define PPAPI_PROXY_PROXY_CHANNEL_H_
   7
   8 #include "base/files/scoped_file.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/shared_memory.h"
  11 #include "base/process/process.h"
  12 #include "ipc/ipc_listener.h"
  13 #include "ipc/ipc_platform_file.h"
  14 #include "ipc/ipc_sender.h"
  15 #include "ipc/ipc_sync_channel.h"
  16 #include "ppapi/proxy/ppapi_proxy_export.h"
  17
  18 namespace base {
  19 class SingleThreadTaskRunner;
  20 class WaitableEvent;
  21 }
  22
  23 namespace IPC {
  24 class TestSink;
  25 }
  26
  27 namespace ppapi {
  28 namespace proxy {
  29
  30 class PPAPI_PROXY_EXPORT ProxyChannel
  31     : public IPC::Listener,
  32       public IPC::Sender {
  33  public:
  34   class PPAPI_PROXY_EXPORT Delegate {
  35    public:
  36     virtual ~Delegate() {}
  37
  38     // Returns the task runner for processing IPC requests.
  39     virtual base::SingleThreadTaskRunner* GetIPCTaskRunner() = 0;
  40
  41     // Returns the event object that becomes signalled when the main thread's
  42     // message loop exits.
  43     virtual base::WaitableEvent* GetShutdownEvent() = 0;
  44
  45     // Duplicates a handle to the provided object, returning one that is valid
  46     // on the other side of the channel. This is part of the delegate interface
  47     // because both sides of the channel may not have sufficient permission to
  48     // duplicate handles directly. The implementation must provide the same
  49     // guarantees as ProxyChannel::ShareHandleWithRemote below.
  50     virtual IPC::PlatformFileForTransit ShareHandleWithRemote(
  51         base::PlatformFile handle,
  52         base::ProcessId remote_pid,
  53         bool should_close_source) = 0;
  54
  55     // Duplicates a shared memory handle, returning one that is valid on the
  56     // other side of the channel. This is part of the delegate interface
  57     // because both sides of the channel may not have sufficient permission to
  58     // duplicate handles directly. The implementation must provide the same
  59     // guarantees as ProxyChannel::ShareSharedMemoryHandleWithRemote below.
  60     virtual base::SharedMemoryHandle ShareSharedMemoryHandleWithRemote(
  61         const base::SharedMemoryHandle& handle,
  62         base::ProcessId remote_pid) = 0;
  63   };
  64
  65   ~ProxyChannel() override;
  66
  67   // Alternative to InitWithChannel() for unit tests that want to send all
  68   // messages sent via this channel to the given test sink. The test sink
  69   // must outlive this class. In this case, the peer PID will be the current
  70   // process ID.
  71   void InitWithTestSink(IPC::TestSink* test_sink);
  72
  73   // Shares a file handle (HANDLE / file descriptor) with the remote side. It
  74   // returns a handle that should be sent in exactly one IPC message. Upon
  75   // receipt, the remote side then owns that handle. Note: if sending the
  76   // message fails, the returned handle is properly closed by the IPC system. If
  77   // should_close_source is set to true, the original handle is closed by this
  78   // operation and should not be used again.
  79   IPC::PlatformFileForTransit ShareHandleWithRemote(
  80       base::PlatformFile handle,
  81       bool should_close_source);
  82
  83   // Shares a shared memory handle with the remote side. It returns a handle
  84   // that should be sent in exactly one IPC message. Upon receipt, the remote
  85   // side then owns that handle. Note: if sending the message fails, the
  86   // returned handle is properly closed by the IPC system. The original handle
  87   // is not closed by this operation.
  88   base::SharedMemoryHandle ShareSharedMemoryHandleWithRemote(
  89       const base::SharedMemoryHandle& handle);
  90
  91   // IPC::Sender implementation.
  92   bool Send(IPC::Message* msg) override;
  93
  94   // IPC::Listener implementation.
  95   void OnChannelError() override;
  96
  97   // Will be NULL in some unit tests and if the remote side has crashed.
  98   IPC::SyncChannel* channel() const {
  99     return channel_.get();
 100   }
 101
 102 #if defined(OS_POSIX) && !defined(OS_NACL)
 103   base::ScopedFD TakeRendererFD();
 104 #endif
 105
 106  protected:
 107   explicit ProxyChannel();
 108
 109   // You must call this function before anything else. Returns true on success.
 110   // The delegate pointer must outlive this class, ownership is not
 111   // transferred.
 112   virtual bool InitWithChannel(Delegate* delegate,
 113                                base::ProcessId peer_pid,
 114                                const IPC::ChannelHandle& channel_handle,
 115                                bool is_client);
 116
 117   ProxyChannel::Delegate* delegate() const {
 118     return delegate_;
 119   }
 120
 121  private:
 122   // Non-owning pointer. Guaranteed non-NULL after init is called.
 123   ProxyChannel::Delegate* delegate_;
 124
 125   // PID of the remote process. Use this instead of the Channel::peer_pid since
 126   // this is set synchronously on construction rather than waiting on the
 127   // "hello" message from the peer (which introduces a race condition).
 128   base::ProcessId peer_pid_;
 129
 130   // When we're unit testing, this will indicate the sink for the messages to
 131   // be deposited so they can be inspected by the test. When non-NULL, this
 132   // indicates that the channel should not be used.
 133   IPC::TestSink* test_sink_;
 134
 135   // Will be null for some tests when there is a test_sink_, and if the
 136   // remote side has crashed.
 137   scoped_ptr<IPC::SyncChannel> channel_;
 138
 139   DISALLOW_COPY_AND_ASSIGN(ProxyChannel);
 140 };
 141
 142 }  // namespace proxy
 143 }  // namespace ppapi
 144
 145 #endif  // PPAPI_PROXY_PROXY_CHANNEL_H_