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 <stdint.h>
  11
  12 #include <queue>
  13 #include <string>
  14
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/memory/weak_ptr.h"
  17 #include "base/message_loop/message_loop.h"
  18 #include "base/win/scoped_handle.h"
  19 #include "ipc/ipc_channel_reader.h"
  20
  21 namespace base {
  22 class ThreadChecker;
  23 }
  24
  25 namespace IPC {
  26
  27 class ChannelWin : public Channel,
  28                    public internal::ChannelReader,
  29                    public base::MessageLoopForIO::IOHandler {
  30  public:
  31   // Mirror methods of Channel, see ipc_channel.h for description.
  32   // |broker| must outlive the newly created object.
  33   ChannelWin(const IPC::ChannelHandle& channel_handle,
  34              Mode mode,
  35              Listener* listener,
  36              AttachmentBroker* broker);
  37   ~ChannelWin() override;
  38
  39   // Channel implementation
  40   bool Connect() override;
  41   void Close() override;
  42   bool Send(Message* message) override;
  43   AttachmentBroker* GetAttachmentBroker() override;
  44   base::ProcessId GetPeerPID() const override;
  45   base::ProcessId GetSelfPID() const override;
  46
  47   static bool IsNamedServerInitialized(const std::string& channel_id);
  48
  49
  50  private:
  51   // ChannelReader implementation.
  52   ReadState ReadData(char* buffer, int buffer_len, int* bytes_read) override;
  53   bool ShouldDispatchInputMessage(Message* msg) override;
  54   bool GetNonBrokeredAttachments(Message* msg) override;
  55   bool DidEmptyInputBuffers() override;
  56   void HandleInternalMessage(const Message& msg) override;
  57   base::ProcessId GetSenderPID() override;
  58   bool IsAttachmentBrokerEndpoint() override;
  59
  60   static const base::string16 PipeName(const std::string& channel_id,
  61                                        int32_t* secret);
  62   bool CreatePipe(const IPC::ChannelHandle &channel_handle, Mode mode);
  63
  64   bool ProcessConnection();
  65   bool ProcessOutgoingMessages(base::MessageLoopForIO::IOContext* context,
  66                                DWORD bytes_written);
  67
  68   // Returns |false| on channel error.
  69   // If |message| has brokerable attachments, those attachments are passed to
  70   // the AttachmentBroker (which in turn invokes Send()), so this method must
  71   // be re-entrant.
  72   // Adds |message| to |output_queue_| and calls ProcessOutgoingMessages().
  73   bool ProcessMessageForDelivery(Message* message);
  74
  75   // Moves all messages from |prelim_queue_| to |output_queue_| by calling
  76   // ProcessMessageForDelivery().
  77   void FlushPrelimQueue();
  78
  79   // MessageLoop::IOHandler implementation.
  80   void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
  81                      DWORD bytes_transfered,
  82                      DWORD error) override;
  83
  84  private:
  85   struct State {
  86     explicit State(ChannelWin* channel);
  87     ~State();
  88     base::MessageLoopForIO::IOContext context;
  89     bool is_pending;
  90   };
  91
  92   State input_state_;
  93   State output_state_;
  94
  95   base::win::ScopedHandle pipe_;
  96
  97   base::ProcessId peer_pid_;
  98
  99   // Messages not yet ready to be sent are queued here. Messages removed from
 100   // this queue are placed in the output_queue_. The double queue is
 101   // unfortunate, but is necessary because messages with brokerable attachments
 102   // can generate multiple messages to be sent (possibly from other channels).
 103   // Some of these generated messages cannot be sent until |peer_pid_| has been
 104   // configured.
 105   // As soon as |peer_pid| has been configured, there is no longer any need for
 106   // |prelim_queue_|. All messages are flushed, and no new messages are added.
 107   std::queue<Message*> prelim_queue_;
 108
 109   // Messages to be sent are queued here.
 110   std::queue<OutputElement*> output_queue_;
 111
 112   // In server-mode, we have to wait for the client to connect before we
 113   // can begin reading.  We make use of the input_state_ when performing
 114   // the connect operation in overlapped mode.
 115   bool waiting_connect_;
 116
 117   // This flag is set when processing incoming messages.  It is used to
 118   // avoid recursing through ProcessIncomingMessages, which could cause
 119   // problems.  TODO(darin): make this unnecessary
 120   bool processing_incoming_;
 121
 122   // Determines if we should validate a client's secret on connection.
 123   bool validate_client_;
 124
 125   // Tracks the lifetime of this object, for debugging purposes.
 126   uint32_t debug_flags_;
 127
 128   // This is a unique per-channel value used to authenticate the client end of
 129   // a connection. If the value is non-zero, the client passes it in the hello
 130   // and the host validates. (We don't send the zero value fto preserve IPC
 131   // compatability with existing clients that don't validate the channel.)
 132   int32_t client_secret_;
 133
 134   scoped_ptr<base::ThreadChecker> thread_check_;
 135
 136   // |broker_| must outlive this instance.
 137   AttachmentBroker* broker_;
 138
 139   base::WeakPtrFactory<ChannelWin> weak_factory_;
 140   DISALLOW_COPY_AND_ASSIGN(ChannelWin);
 141 };
 142
 143 }  // namespace IPC
 144
 145 #endif  // IPC_IPC_CHANNEL_WIN_H_