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chromium / chromium / src / 2ce26c438a2cd219348eefa324a64c15d1bf8cf2 / . / ipc / ipc_channel.h
blob: 718f2b393d5acdee3e606b899460e31a99ddb027 [file] [log] [blame]
wez@chromium.org8ec3fbe2011-04-06 12:01:44[diff] [blame]1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
license.botbf09a502008-08-24 00:55:55[diff] [blame]2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]4
agl@chromium.org946d1b22009-07-22 23:57:21[diff] [blame]5#ifndef IPC_IPC_CHANNEL_H_
6#define IPC_IPC_CHANNEL_H_
thakis@chromium.org32b76ef2010-07-26 23:08:24[diff] [blame]7#pragma once
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]8
evan@chromium.org39703fb2010-10-19 19:11:15[diff] [blame]9#include "base/compiler_specific.h"
dmaclach@chromium.org42ce94e2010-12-08 19:28:09[diff] [blame]10#include "ipc/ipc_channel_handle.h"
agl@chromium.org946d1b22009-07-22 23:57:21[diff] [blame]11#include "ipc/ipc_message.h"
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]12
13namespace IPC {
14
15//------------------------------------------------------------------------------
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]16// See
17// http://www.chromium.org/developers/design-documents/inter-process-communication
18// for overview of IPC in Chromium.
19
20// Channels are implemented using named pipes on Windows, and
21// socket pairs (or in some special cases unix domain sockets) on POSIX.
22// On Windows we access pipes in various processes by name.
23// On POSIX we pass file descriptors to child processes and assign names to them
24// in a lookup table.
25// In general on POSIX we do not use unix domain sockets due to security
26// concerns and the fact that they can leave garbage around the file system
27// (MacOS does not support abstract named unix domain sockets).
28// You can use unix domain sockets if you like on POSIX by constructing the
29// the channel with the mode set to one of the NAMED modes. NAMED modes are
30// currently used by automation and service processes.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]31
darin@chromium.org7c854372011-08-15 20:41:46[diff] [blame]32class IPC_EXPORT Channel : public Message::Sender {
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]33 // Security tests need access to the pipe handle.
34 friend class ChannelTest;
35
36 public:
37 // Implemented by consumers of a Channel to receive messages.
darin@chromium.org7c854372011-08-15 20:41:46[diff] [blame]38 class IPC_EXPORT Listener {
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]39 public:
darin@google.comc8ea1ef2008-09-06 18:07:10[diff] [blame]40 virtual ~Listener() {}
41
jam@chromium.orga95986a2010-12-24 06:19:28[diff] [blame]42 // Called when a message is received. Returns true iff the message was
43 // handled.
44 virtual bool OnMessageReceived(const Message& message) = 0;
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]45
46 // Called when the channel is connected and we have received the internal
47 // Hello message from the peer.
48 virtual void OnChannelConnected(int32 peer_pid) {}
49
50 // Called when an error is detected that causes the channel to close.
51 // This method is not called when a channel is closed normally.
52 virtual void OnChannelError() {}
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]53
54#if defined(OS_POSIX)
55 // Called on the server side when a channel that listens for connections
56 // denies an attempt to connect.
57 virtual void OnChannelDenied() {}
58
59 // Called on the server side when a channel that listens for connections
60 // has an error that causes the listening channel to close.
61 virtual void OnChannelListenError() {}
62#endif // OS_POSIX
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]63 };
64
dmaclach@chromium.org1707726c2011-02-03 20:35:09[diff] [blame]65 // Flags to test modes
66 enum ModeFlags {
67 MODE_NO_FLAG = 0x0,
68 MODE_SERVER_FLAG = 0x1,
69 MODE_CLIENT_FLAG = 0x2,
wez@chromium.org8ec3fbe2011-04-06 12:01:44[diff] [blame]70 MODE_NAMED_FLAG = 0x4,
71#if defined(OS_POSIX)
72 MODE_OPEN_ACCESS_FLAG = 0x8, // Don't restrict access based on client UID.
73#endif
dmaclach@chromium.org1707726c2011-02-03 20:35:09[diff] [blame]74 };
75
76 // Some Standard Modes
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]77 enum Mode {
dmaclach@chromium.org1707726c2011-02-03 20:35:09[diff] [blame]78 MODE_NONE = MODE_NO_FLAG,
79 MODE_SERVER = MODE_SERVER_FLAG,
80 MODE_CLIENT = MODE_CLIENT_FLAG,
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]81 // Channels on Windows are named by default and accessible from other
82 // processes. On POSIX channels are anonymous by default and not accessible
83 // from other processes. Named channels work via named unix domain sockets.
dmaclach@chromium.org1707726c2011-02-03 20:35:09[diff] [blame]84 // On Windows MODE_NAMED_SERVER is equivalent to MODE_SERVER and
85 // MODE_NAMED_CLIENT is equivalent to MODE_CLIENT.
86 MODE_NAMED_SERVER = MODE_SERVER_FLAG | MODE_NAMED_FLAG,
87 MODE_NAMED_CLIENT = MODE_CLIENT_FLAG | MODE_NAMED_FLAG,
wez@chromium.org8ec3fbe2011-04-06 12:01:44[diff] [blame]88#if defined(OS_POSIX)
89 // An "open" named server accepts connections from ANY client.
90 // The caller must then implement their own access-control based on the
91 // client process' user Id.
92 MODE_OPEN_NAMED_SERVER = MODE_OPEN_ACCESS_FLAG | MODE_SERVER_FLAG |
93 MODE_NAMED_FLAG
94#endif
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]95 };
96
pkasting@chromium.org05094a32011-09-01 00:50:13[diff] [blame]97 // The maximum message size in bytes. Attempting to receive a message of this
98 // size or bigger results in a channel error.
99 static const size_t kMaximumMessageSize = 128 * 1024 * 1024;
jeremy@chromium.org514411fc2008-12-10 22:28:11[diff] [blame]100
pkasting@chromium.org05094a32011-09-01 00:50:13[diff] [blame]101 // Ammount of data to read at once from the pipe.
102 static const size_t kReadBufferSize = 4 * 1024;
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]103
104 // Initialize a Channel.
105 //
dmaclach@chromium.org42ce94e2010-12-08 19:28:09[diff] [blame]106 // |channel_handle| identifies the communication Channel. For POSIX, if
107 // the file descriptor in the channel handle is != -1, the channel takes
108 // ownership of the file descriptor and will close it appropriately, otherwise
109 // it will create a new descriptor internally.
rvargas@google.comc1afbd2c2008-10-13 19:19:36[diff] [blame]110 // |mode| specifies whether this Channel is to operate in server mode or
111 // client mode. In server mode, the Channel is responsible for setting up the
112 // IPC object, whereas in client mode, the Channel merely connects to the
113 // already established IPC object.
114 // |listener| receives a callback on the current thread for each newly
115 // received message.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]116 //
dmaclach@chromium.org42ce94e2010-12-08 19:28:09[diff] [blame]117 Channel(const IPC::ChannelHandle &channel_handle, Mode mode,
118 Listener* listener);
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]119
hans@chromium.org3690ebe02011-05-25 09:08:19[diff] [blame]120 virtual ~Channel();
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]121
122 // Connect the pipe. On the server side, this will initiate
123 // waiting for connections. On the client, it attempts to
124 // connect to a pre-existing pipe. Note, calling Connect()
125 // will not block the calling thread and may complete
126 // asynchronously.
evan@chromium.org39703fb2010-10-19 19:11:15[diff] [blame]127 bool Connect() WARN_UNUSED_RESULT;
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]128
129 // Close this Channel explicitly. May be called multiple times.
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]130 // On POSIX calling close on an IPC channel that listens for connections will
131 // cause it to close any accepted connections, and it will stop listening for
132 // new connections. If you just want to close the currently accepted
133 // connection and listen for new ones, use ResetToAcceptingConnectionState.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]134 void Close();
135
136 // Modify the Channel's listener.
jeremy@chromium.org514411fc2008-12-10 22:28:11[diff] [blame]137 void set_listener(Listener* listener);
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]138
139 // Send a message over the Channel to the listener on the other end.
140 //
rvargas@google.comc1afbd2c2008-10-13 19:19:36[diff] [blame]141 // |message| must be allocated using operator new. This object will be
142 // deleted once the contents of the Message have been sent.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]143 virtual bool Send(Message* message);
144
abarth@chromium.orgb4fa72932010-11-12 18:01:34[diff] [blame]145#if defined(OS_POSIX) && !defined(OS_NACL)
jeremy@chromium.orgdf3c1ca12008-12-19 21:37:01[diff] [blame]146 // On POSIX an IPC::Channel wraps a socketpair(), this method returns the
agl@chromium.orgcc8f1462009-06-12 17:36:55[diff] [blame]147 // FD # for the client end of the socket.
jeremy@chromium.orgdf3c1ca12008-12-19 21:37:01[diff] [blame]148 // This method may only be called on the server side of a channel.
phajdan.jr@chromium.org2ce26c432011-09-19 17:08:12[diff] [blame^]149 // This method can be called on any thread.
agl@chromium.orgcc8f1462009-06-12 17:36:55[diff] [blame]150 int GetClientFileDescriptor() const;
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]151
phajdan.jr@chromium.org2ce26c432011-09-19 17:08:12[diff] [blame^]152 // Same as GetClientFileDescriptor, but transfers the ownership of the
153 // file descriptor to the caller.
154 // This method can be called on any thread.
155 int TakeClientFileDescriptor();
156
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]157 // On POSIX an IPC::Channel can either wrap an established socket, or it
158 // can wrap a socket that is listening for connections. Currently an
159 // IPC::Channel that listens for connections can only accept one connection
160 // at a time.
161
162 // Returns true if the channel supports listening for connections.
163 bool AcceptsConnections() const;
164
165 // Returns true if the channel supports listening for connections and is
166 // currently connected.
167 bool HasAcceptedConnection() const;
168
wez@chromium.org8ec3fbe2011-04-06 12:01:44[diff] [blame]169 // Returns true if the peer process' effective user id can be determined, in
170 // which case the supplied client_euid is updated with it.
171 bool GetClientEuid(uid_t* client_euid) const;
172
dmaclach@chromium.org22b42c52010-12-20 06:59:23[diff] [blame]173 // Closes any currently connected socket, and returns to a listening state
174 // for more connections.
175 void ResetToAcceptingConnectionState();
wez@chromium.org8ec3fbe2011-04-06 12:01:44[diff] [blame]176#endif // defined(OS_POSIX) && !defined(OS_NACL)
neb@chromium.org74f27542010-03-31 17:44:57[diff] [blame]177
kkania@chromium.org313c00e52011-08-09 06:46:06[diff] [blame]178 // Returns true if a named server channel is initialized on the given channel
179 // ID. Even if true, the server may have already accepted a connection.
180 static bool IsNamedServerInitialized(const std::string& channel_id);
181
jamescook@chromium.orge1d67a882011-08-31 21:11:04[diff] [blame]182#if defined(OS_LINUX)
183 // Sandboxed processes live in a PID namespace, so when sending the IPC hello
184 // message from client to server we need to send the PID from the global
185 // PID namespace.
186 static void SetGlobalPid(int pid);
187#endif
188
neb@chromium.org90b721e62010-04-05 17:35:01[diff] [blame]189 protected:
190 // Used in Chrome by the TestSink to provide a dummy channel implementation
191 // for testing. TestSink overrides the "interesting" functions in Channel so
192 // no actual implementation is needed. This will cause un-overridden calls to
193 // segfault. Do not use outside of test code!
194 Channel() : channel_impl_(0) { }
195
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]196 private:
jeremy@chromium.org514411fc2008-12-10 22:28:11[diff] [blame]197 // PIMPL to which all channel calls are delegated.
198 class ChannelImpl;
199 ChannelImpl *channel_impl_;
rvargas@google.comc1afbd2c2008-10-13 19:19:36[diff] [blame]200
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]201 // The Hello message is internal to the Channel class. It is sent
202 // by the peer when the channel is connected. The message contains
203 // just the process id (pid). The message has a special routing_id
204 // (MSG_ROUTING_NONE) and type (HELLO_MESSAGE_TYPE).
205 enum {
nsylvain@chromium.orgd4651ff2008-12-02 16:51:58[diff] [blame]206 HELLO_MESSAGE_TYPE = kuint16max // Maximum value of message type (uint16),
207 // to avoid conflicting with normal
208 // message types, which are enumeration
209 // constants starting from 0.
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]210 };
211};
212
jeremy@chromium.org514411fc2008-12-10 22:28:11[diff] [blame]213} // namespace IPC
initial.commit09911bf2008-07-26 23:55:29[diff] [blame]214
agl@chromium.org946d1b22009-07-22 23:57:21[diff] [blame]215#endif // IPC_IPC_CHANNEL_H_