ipc/ipc_channel_win.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 IPC_IPC_CHANNEL_WIN_H_
   6 #define IPC_IPC_CHANNEL_WIN_H_
   7
   8 #include "ipc/ipc_channel.h"
   9
  10 #include <queue>
  11 #include <string>
  12
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/message_loop/message_loop.h"
  16 #include "base/win/scoped_handle.h"
  17 #include "ipc/ipc_channel_reader.h"
  18
  19 namespace base {
  20 class ThreadChecker;
  21 }
  22
  23 namespace IPC {
  24
  25 class ChannelWin : public Channel,
  26                    public internal::ChannelReader,
  27                    public base::MessageLoopForIO::IOHandler {
  28  public:
  29   // Mirror methods of Channel, see ipc_channel.h for description.
  30   // |broker| must outlive the newly created object.
  31   ChannelWin(const IPC::ChannelHandle& channel_handle,
  32              Mode mode,
  33              Listener* listener,
  34              AttachmentBroker* broker);
  35   ~ChannelWin() override;
  36
  37   // Channel implementation
  38   bool Connect() override;
  39   void Close() override;
  40   bool Send(Message* message) override;
  41   AttachmentBroker* GetAttachmentBroker() override;
  42   base::ProcessId GetPeerPID() const override;
  43   base::ProcessId GetSelfPID() const override;
  44
  45   static bool IsNamedServerInitialized(const std::string& channel_id);
  46
  47
  48  private:
  49   // ChannelReader implementation.
  50   ReadState ReadData(char* buffer, int buffer_len, int* bytes_read) override;
  51   bool ShouldDispatchInputMessage(Message* msg) override;
  52   bool GetNonBrokeredAttachments(Message* msg) override;
  53   bool DidEmptyInputBuffers() override;
  54   void HandleInternalMessage(const Message& msg) override;
  55   base::ProcessId GetSenderPID() override;
  56   bool IsAttachmentBrokerEndpoint() override;
  57
  58   static const base::string16 PipeName(const std::string& channel_id,
  59                                        int32* secret);
  60   bool CreatePipe(const IPC::ChannelHandle &channel_handle, Mode mode);
  61
  62   bool ProcessConnection();
  63   bool ProcessOutgoingMessages(base::MessageLoopForIO::IOContext* context,
  64                                DWORD bytes_written);
  65
  66   // Returns |false| on channel error.
  67   // If |message| has brokerable attachments, those attachments are passed to
  68   // the AttachmentBroker (which in turn invokes Send()), so this method must
  69   // be re-entrant.
  70   // Adds |message| to |output_queue_| and calls ProcessOutgoingMessages().
  71   bool ProcessMessageForDelivery(Message* message);
  72
  73   // Moves all messages from |prelim_queue_| to |output_queue_| by calling
  74   // ProcessMessageForDelivery().
  75   void FlushPrelimQueue();
  76
  77   // MessageLoop::IOHandler implementation.
  78   void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
  79                      DWORD bytes_transfered,
  80                      DWORD error) override;
  81
  82  private:
  83   struct State {
  84     explicit State(ChannelWin* channel);
  85     ~State();
  86     base::MessageLoopForIO::IOContext context;
  87     bool is_pending;
  88   };
  89
  90   State input_state_;
  91   State output_state_;
  92
  93   base::win::ScopedHandle pipe_;
  94
  95   base::ProcessId peer_pid_;
  96
  97   // Messages not yet ready to be sent are queued here. Messages removed from
  98   // this queue are placed in the output_queue_. The double queue is
  99   // unfortunate, but is necessary because messages with brokerable attachments
 100   // can generate multiple messages to be sent (possibly from other channels).
 101   // Some of these generated messages cannot be sent until |peer_pid_| has been
 102   // configured.
 103   // As soon as |peer_pid| has been configured, there is no longer any need for
 104   // |prelim_queue_|. All messages are flushed, and no new messages are added.
 105   std::queue<Message*> prelim_queue_;
 106
 107   // Messages to be sent are queued here.
 108   std::queue<OutputElement*> output_queue_;
 109
 110   // In server-mode, we have to wait for the client to connect before we
 111   // can begin reading.  We make use of the input_state_ when performing
 112   // the connect operation in overlapped mode.
 113   bool waiting_connect_;
 114
 115   // This flag is set when processing incoming messages.  It is used to
 116   // avoid recursing through ProcessIncomingMessages, which could cause
 117   // problems.  TODO(darin): make this unnecessary
 118   bool processing_incoming_;
 119
 120   // Determines if we should validate a client's secret on connection.
 121   bool validate_client_;
 122
 123   // Tracks the lifetime of this object, for debugging purposes.
 124   uint32 debug_flags_;
 125
 126   // This is a unique per-channel value used to authenticate the client end of
 127   // a connection. If the value is non-zero, the client passes it in the hello
 128   // and the host validates. (We don't send the zero value fto preserve IPC
 129   // compatability with existing clients that don't validate the channel.)
 130   int32 client_secret_;
 131
 132   scoped_ptr<base::ThreadChecker> thread_check_;
 133
 134   // |broker_| must outlive this instance.
 135   AttachmentBroker* broker_;
 136
 137   base::WeakPtrFactory<ChannelWin> weak_factory_;
 138   DISALLOW_COPY_AND_ASSIGN(ChannelWin);
 139 };
 140
 141 }  // namespace IPC
 142
 143 #endif  // IPC_IPC_CHANNEL_WIN_H_