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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 | 221 |
1 files changed, 221 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 0000000000..3cd04ba3de --- /dev/null +++ b/ipc/chromium/src/chrome/common/ipc_channel.h @@ -0,0 +1,221 @@ +/* -*- 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 <cstdint> +#include <queue> +#include "base/basictypes.h" +#include "base/process.h" +#include "build/build_config.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/UniquePtrExtensions.h" +#include "mozilla/WeakPtr.h" +#include "chrome/common/ipc_message.h" + +#ifdef OS_WIN +# include <string> +#endif + +namespace IPC { + +class Message; +class MessageReader; +class MessageWriter; + +//------------------------------------------------------------------------------ + +class Channel { + // Security tests need access to the pipe handle. + friend class ChannelTest; + + public: + // Windows channels use named objects and connect to them by name, + // but on Unix we use unnamed socketpairs and pass capabilities + // directly using SCM_RIGHTS messages. This type abstracts away + // that difference. +#ifdef OS_WIN + typedef std::wstring ChannelId; +#else + struct ChannelId {}; +#endif + + // For channels which are created after initialization, handles to the pipe + // endpoints may be passed around directly using IPC messages. + using ChannelHandle = mozilla::UniqueFileHandle; + + // Implemented by consumers of a Channel to receive messages. + // + // All listeners will only be called on the IO thread, and must be destroyed + // on the IO thread. + class Listener : public mozilla::SupportsWeakPtr { + public: + virtual ~Listener() = default; + + // Called when a message is received. + virtual void OnMessageReceived(mozilla::UniquePtr<Message> message) = 0; + + // Called when the channel is connected and we have received the internal + // Hello message from the peer. + virtual void OnChannelConnected(base::ProcessId 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<mozilla::UniquePtr<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. + // This is larger in fuzzing builds to allow the fuzzing of passing + // large data structures into DOM methods without crashing. +#ifndef FUZZING + kMaximumMessageSize = 256 * 1024 * 1024, +#else + kMaximumMessageSize = 1792 * 1024 * 1024, // 1.75GB +#endif + + // Amount of data to read at once from the pipe. + kReadBufferSize = 4 * 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. + // + // The Channel must be created and destroyed on the IO thread, and all + // methods, unless otherwise noted, are only safe to call on the I/O thread. + // + Channel(const ChannelId& channel_id, Mode mode, Listener* listener); + + // Initialize a pre-created channel |pipe| as |mode|. + Channel(ChannelHandle pipe, Mode mode, Listener* listener); + + ~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. + // + // This method may be called from any thread, so long as the `Channel` is not + // destroyed before it returns. + // + // If you Send() a message on a Close()'d channel, we delete the message + // immediately. + bool Send(mozilla::UniquePtr<Message> message); + + // The PID which this channel has been opened with. This will be + // `-1` until `OnChannelConnected` has been called. + int32_t OtherPid() const; + + // IsClosed() is safe to call from any thread, but the value returned may + // be out of date. + bool IsClosed() 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. + void GetClientFileDescriptorMapping(int* src_fd, int* dest_fd) const; + + // Close the client side of the socketpair. + void CloseClientFileDescriptor(); + +# if defined(OS_MACOSX) + // Configure the mach task_t for the peer task. + void SetOtherMachTask(task_t task); + + // Tell this pipe to accept mach ports. Exactly one side of the IPC connection + // must be set as `MODE_SERVER` and that side will be responsible for + // transferring the rights between processes. + void StartAcceptingMachPorts(Mode mode); +# endif + +#elif defined(OS_WIN) + // Tell this pipe to accept handles. Exactly one side of the IPC connection + // must be set as `MODE_SERVER`, and that side will be responsible for calling + // `DuplicateHandle` to transfer the handle between processes. + void StartAcceptingHandles(Mode mode); +#endif // defined(OS_POSIX) + + // On Windows: Generates a channel ID that, if passed to the client + // as a shared secret, will validate the client's authenticity. + // Other platforms don't use channel IDs, so this returns the dummy + // ChannelId value. + static ChannelId GenerateVerifiedChannelID(); + + // On Windows: Retrieves the initial channel ID passed to the + // current process by its parent. Other platforms don't do this; + // the dummy ChannelId value is returned instead. + static ChannelId ChannelIDForCurrentProcess(); + +#if defined(MOZ_WIDGET_ANDROID) + // Used to set the first IPC file descriptor in the child process on Android. + // See ipc_channel_posix.cc for further details on how this is used. + static void SetClientChannelFd(int fd); +#endif // defined(MOZ_WIDGET_ANDROID) + + // Create a new pair of pipe endpoints which can be used to establish a + // native IPC::Channel connection. + static bool CreateRawPipe(ChannelHandle* server, ChannelHandle* client); + + private: + // PIMPL to which all channel calls are delegated. + class ChannelImpl; + RefPtr<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_ |