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Diffstat (limited to 'ipc/chromium/src/chrome/common/ipc_channel.h')
-rw-r--r-- | ipc/chromium/src/chrome/common/ipc_channel.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/ipc/chromium/src/chrome/common/ipc_channel.h b/ipc/chromium/src/chrome/common/ipc_channel.h new file mode 100644 index 000000000..e6b45986e --- /dev/null +++ b/ipc/chromium/src/chrome/common/ipc_channel.h @@ -0,0 +1,179 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef CHROME_COMMON_IPC_CHANNEL_H_ +#define CHROME_COMMON_IPC_CHANNEL_H_ + +#include <string> + +#include <queue> +#include "chrome/common/ipc_message.h" + +namespace IPC { + +//------------------------------------------------------------------------------ + +class Channel { + // Security tests need access to the pipe handle. + friend class ChannelTest; + + public: + // Implemented by consumers of a Channel to receive messages. + class Listener { + public: + virtual ~Listener() {} + + // Called when a message is received. + virtual void OnMessageReceived(Message&& message) = 0; + + // Called when the channel is connected and we have received the internal + // Hello message from the peer. + virtual void OnChannelConnected(int32_t peer_pid) {} + + // Called when an error is detected that causes the channel to close. + // This method is not called when a channel is closed normally. + virtual void OnChannelError() {} + + // If the listener has queued messages, swap them for |queue| like so + // swap(impl->my_queued_messages, queue); + virtual void GetQueuedMessages(std::queue<Message>& queue) {} + }; + + enum Mode { + MODE_SERVER, + MODE_CLIENT + }; + + enum { + // The maximum message size in bytes. Attempting to receive a + // message of this size or bigger results in a channel error. + kMaximumMessageSize = 256 * 1024 * 1024, + + // Ammount of data to read at once from the pipe. + kReadBufferSize = 4 * 1024, + + // Maximum size of a message that we allow to be copied (rather than moved). + kMaxCopySize = 32 * 1024, + }; + + // Initialize a Channel. + // + // |channel_id| identifies the communication Channel. + // |mode| specifies whether this Channel is to operate in server mode or + // client mode. In server mode, the Channel is responsible for setting up the + // IPC object, whereas in client mode, the Channel merely connects to the + // already established IPC object. + // |listener| receives a callback on the current thread for each newly + // received message. + // + Channel(const std::wstring& channel_id, Mode mode, Listener* listener); + + // XXX it would nice not to have yet more platform-specific code in + // here but it's just not worth the trouble. +# if defined(OS_POSIX) + // Connect to a pre-created channel |fd| as |mode|. + Channel(int fd, Mode mode, Listener* listener); +# elif defined(OS_WIN) + // Connect to a pre-created channel as |mode|. Clients connect to + // the pre-existing server pipe, and servers take over |server_pipe|. + Channel(const std::wstring& channel_id, void* server_pipe, + Mode mode, Listener* listener); +# endif + + ~Channel(); + + // Connect the pipe. On the server side, this will initiate + // waiting for connections. On the client, it attempts to + // connect to a pre-existing pipe. Note, calling Connect() + // will not block the calling thread and may complete + // asynchronously. + bool Connect(); + + // Close this Channel explicitly. May be called multiple times. + void Close(); + + // Modify the Channel's listener. + Listener* set_listener(Listener* listener); + + // Send a message over the Channel to the listener on the other end. + // + // |message| must be allocated using operator new. This object will be + // deleted once the contents of the Message have been sent. + // + // If you Send() a message on a Close()'d channel, we delete the message + // immediately. + bool Send(Message* message); + + // Unsound_IsClosed() and Unsound_NumQueuedMessages() are safe to call from + // any thread, but the value returned may be out of date, because we don't + // use any synchronization when reading or writing it. + bool Unsound_IsClosed() const; + uint32_t Unsound_NumQueuedMessages() const; + +#if defined(OS_POSIX) + // On POSIX an IPC::Channel wraps a socketpair(), this method returns the + // FD # for the client end of the socket and the equivalent FD# to use for + // mapping it into the Child process. + // This method may only be called on the server side of a channel. + // + // If the kTestingChannelID flag is specified on the command line then + // a named FIFO is used as the channel transport mechanism rather than a + // socketpair() in which case this method returns -1 for both parameters. + void GetClientFileDescriptorMapping(int *src_fd, int *dest_fd) const; + + // Return the file descriptor for communication with the peer. + int GetFileDescriptor() const; + + // Reset the file descriptor for communication with the peer. + void ResetFileDescriptor(int fd); + + // Close the client side of the socketpair. + void CloseClientFileDescriptor(); + +#elif defined(OS_WIN) + // Return the server pipe handle. + void* GetServerPipeHandle() const; +#endif // defined(OS_POSIX) + + // Generates a channel ID that's non-predictable and unique. + static std::wstring GenerateUniqueRandomChannelID(); + + // Generates a channel ID that, if passed to the client as a shared secret, + // will validate that the client's authenticity. On platforms that do not + // require additional validation this is simply calls GenerateUniqueRandomChannelID(). + // For portability the prefix should not include the \ character. + static std::wstring GenerateVerifiedChannelID(const std::wstring& prefix); + + private: + // PIMPL to which all channel calls are delegated. + class ChannelImpl; + ChannelImpl *channel_impl_; + + enum { +#if defined(OS_MACOSX) + // If the channel receives a message that contains file descriptors, then + // it will reply back with this message, indicating that the message has + // been received. The sending channel can then close any descriptors that + // had been marked as auto_close. This works around a sendmsg() bug on BSD + // where the kernel can eagerly close file descriptors that are in message + // queues but not yet delivered. + RECEIVED_FDS_MESSAGE_TYPE = kuint16max - 1, +#endif + + // The Hello message is internal to the Channel class. It is sent + // by the peer when the channel is connected. The message contains + // just the process id (pid). The message has a special routing_id + // (MSG_ROUTING_NONE) and type (HELLO_MESSAGE_TYPE). + HELLO_MESSAGE_TYPE = kuint16max // Maximum value of message type (uint16_t), + // to avoid conflicting with normal + // message types, which are enumeration + // constants starting from 0. + }; +}; + +} // namespace IPC + +#endif // CHROME_COMMON_IPC_CHANNEL_H_ |