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.
5 #include "ipc/ipc_channel_win.h"
9 #include "base/auto_reset.h"
10 #include "base/bind.h"
11 #include "base/compiler_specific.h"
12 #include "base/logging.h"
13 #include "base/pickle.h"
14 #include "base/process/process_handle.h"
15 #include "base/rand_util.h"
16 #include "base/strings/string_number_conversions.h"
17 #include "base/strings/utf_string_conversions.h"
18 #include "base/threading/thread_checker.h"
19 #include "base/win/scoped_handle.h"
20 #include "ipc/ipc_listener.h"
21 #include "ipc/ipc_logging.h"
22 #include "ipc/ipc_message_utils.h"
28 CALLED_CONNECT = 1 << 1,
29 PENDING_CONNECT = 1 << 2,
30 CONNECT_COMPLETED = 1 << 3,
31 PIPE_CONNECTED = 1 << 4,
34 WRITE_COMPLETED = 1 << 7,
35 READ_COMPLETED = 1 << 8,
37 WAIT_FOR_READ = 1 << 10,
38 WAIT_FOR_WRITE = 1 << 11,
39 WAIT_FOR_READ_COMPLETE = 1 << 12,
40 WAIT_FOR_WRITE_COMPLETE = 1 << 13
47 ChannelWin::State::State(ChannelWin* channel) : is_pending(false) {
48 memset(&context.overlapped, 0, sizeof(context.overlapped));
49 context.handler = channel;
52 ChannelWin::State::~State() {
53 COMPILE_ASSERT(!offsetof(ChannelWin::State, context),
54 starts_with_io_context);
57 ChannelWin::ChannelWin(const IPC::ChannelHandle &channel_handle,
58 Mode mode, Listener* listener)
59 : ChannelReader(listener),
62 pipe_(INVALID_HANDLE_VALUE),
63 peer_pid_(base::kNullProcessId),
64 waiting_connect_(mode & MODE_SERVER_FLAG),
65 processing_incoming_(false),
66 validate_client_(false),
71 CreatePipe(channel_handle, mode);
74 ChannelWin::~ChannelWin() {
78 void ChannelWin::Close() {
79 if (thread_check_.get()) {
80 DCHECK(thread_check_->CalledOnValidThread());
82 debug_flags_ |= CLOSED;
84 if (input_state_.is_pending || output_state_.is_pending)
87 // Closing the handle at this point prevents us from issuing more requests
88 // form OnIOCompleted().
89 if (pipe_ != INVALID_HANDLE_VALUE) {
91 pipe_ = INVALID_HANDLE_VALUE;
94 if (input_state_.is_pending)
95 debug_flags_ |= WAIT_FOR_READ;
97 if (output_state_.is_pending)
98 debug_flags_ |= WAIT_FOR_WRITE;
100 // Make sure all IO has completed.
101 base::Time start = base::Time::Now();
102 while (input_state_.is_pending || output_state_.is_pending) {
103 base::MessageLoopForIO::current()->WaitForIOCompletion(INFINITE, this);
106 while (!output_queue_.empty()) {
107 Message* m = output_queue_.front();
113 bool ChannelWin::Send(Message* message) {
114 DCHECK(thread_check_->CalledOnValidThread());
115 DVLOG(2) << "sending message @" << message << " on channel @" << this
116 << " with type " << message->type()
117 << " (" << output_queue_.size() << " in queue)";
119 #ifdef IPC_MESSAGE_LOG_ENABLED
120 Logging::GetInstance()->OnSendMessage(message, "");
123 message->TraceMessageBegin();
124 output_queue_.push(message);
125 // ensure waiting to write
126 if (!waiting_connect_) {
127 if (!output_state_.is_pending) {
128 if (!ProcessOutgoingMessages(NULL, 0))
136 base::ProcessId ChannelWin::GetPeerPID() const {
140 base::ProcessId ChannelWin::GetSelfPID() const {
141 return GetCurrentProcessId();
144 ChannelHandle ChannelWin::TakePipeHandle() {
145 ChannelHandle handle = ChannelHandle(pipe_);
146 pipe_ = INVALID_HANDLE_VALUE;
151 bool ChannelWin::IsNamedServerInitialized(
152 const std::string& channel_id) {
153 if (WaitNamedPipe(PipeName(channel_id, NULL).c_str(), 1))
155 // If ERROR_SEM_TIMEOUT occurred, the pipe exists but is handling another
157 return GetLastError() == ERROR_SEM_TIMEOUT;
160 ChannelWin::ReadState ChannelWin::ReadData(
163 int* /* bytes_read */) {
164 if (INVALID_HANDLE_VALUE == pipe_)
167 debug_flags_ |= READ_MSG;
168 DWORD bytes_read = 0;
169 BOOL ok = ReadFile(pipe_, buffer, buffer_len,
170 &bytes_read, &input_state_.context.overlapped);
172 DWORD err = GetLastError();
173 if (err == ERROR_IO_PENDING) {
174 input_state_.is_pending = true;
177 LOG(ERROR) << "pipe error: " << err;
181 // We could return READ_SUCCEEDED here. But the way that this code is
182 // structured we instead go back to the message loop. Our completion port
183 // will be signalled even in the "synchronously completed" state.
185 // This allows us to potentially process some outgoing messages and
186 // interleave other work on this thread when we're getting hammered with
187 // input messages. Potentially, this could be tuned to be more efficient
188 // with some testing.
189 input_state_.is_pending = true;
193 bool ChannelWin::WillDispatchInputMessage(Message* msg) {
194 // Make sure we get a hello when client validation is required.
195 if (validate_client_)
196 return IsHelloMessage(*msg);
200 void ChannelWin::HandleInternalMessage(const Message& msg) {
201 DCHECK_EQ(msg.type(), static_cast<unsigned>(Channel::HELLO_MESSAGE_TYPE));
202 // The hello message contains one parameter containing the PID.
203 PickleIterator it(msg);
205 bool failed = !it.ReadInt(&claimed_pid);
207 if (!failed && validate_client_) {
209 failed = it.ReadInt(&secret) ? (secret != client_secret_) : true;
215 listener()->OnChannelError();
219 peer_pid_ = claimed_pid;
220 // Validation completed.
221 validate_client_ = false;
222 listener()->OnChannelConnected(claimed_pid);
225 bool ChannelWin::DidEmptyInputBuffers() {
226 // We don't need to do anything here.
231 const base::string16 ChannelWin::PipeName(
232 const std::string& channel_id, int32* secret) {
233 std::string name("\\\\.\\pipe\\chrome.");
235 // Prevent the shared secret from ending up in the pipe name.
236 size_t index = channel_id.find_first_of('\\');
237 if (index != std::string::npos) {
238 if (secret) // Retrieve the secret if asked for.
239 base::StringToInt(channel_id.substr(index + 1), secret);
240 return base::ASCIIToWide(name.append(channel_id.substr(0, index - 1)));
243 // This case is here to support predictable named pipes in tests.
246 return base::ASCIIToWide(name.append(channel_id));
249 bool ChannelWin::CreatePipe(const IPC::ChannelHandle &channel_handle,
251 DCHECK_EQ(INVALID_HANDLE_VALUE, pipe_);
252 base::string16 pipe_name;
253 // If we already have a valid pipe for channel just copy it.
254 if (channel_handle.pipe.handle) {
255 DCHECK(channel_handle.name.empty());
256 pipe_name = L"Not Available"; // Just used for LOG
257 // Check that the given pipe confirms to the specified mode. We can
258 // only check for PIPE_TYPE_MESSAGE & PIPE_SERVER_END flags since the
259 // other flags (PIPE_TYPE_BYTE, and PIPE_CLIENT_END) are defined as 0.
261 GetNamedPipeInfo(channel_handle.pipe.handle, &flags, NULL, NULL, NULL);
262 DCHECK(!(flags & PIPE_TYPE_MESSAGE));
263 if (((mode & MODE_SERVER_FLAG) && !(flags & PIPE_SERVER_END)) ||
264 ((mode & MODE_CLIENT_FLAG) && (flags & PIPE_SERVER_END))) {
265 LOG(WARNING) << "Inconsistent open mode. Mode :" << mode;
268 if (!DuplicateHandle(GetCurrentProcess(),
269 channel_handle.pipe.handle,
274 DUPLICATE_SAME_ACCESS)) {
275 LOG(WARNING) << "DuplicateHandle failed. Error :" << GetLastError();
278 } else if (mode & MODE_SERVER_FLAG) {
279 DCHECK(!channel_handle.pipe.handle);
280 const DWORD open_mode = PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED |
281 FILE_FLAG_FIRST_PIPE_INSTANCE;
282 pipe_name = PipeName(channel_handle.name, &client_secret_);
283 validate_client_ = !!client_secret_;
284 pipe_ = CreateNamedPipeW(pipe_name.c_str(),
286 PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
288 Channel::kReadBufferSize,
289 Channel::kReadBufferSize,
292 } else if (mode & MODE_CLIENT_FLAG) {
293 DCHECK(!channel_handle.pipe.handle);
294 pipe_name = PipeName(channel_handle.name, &client_secret_);
295 pipe_ = CreateFileW(pipe_name.c_str(),
296 GENERIC_READ | GENERIC_WRITE,
300 SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION |
301 FILE_FLAG_OVERLAPPED,
307 if (pipe_ == INVALID_HANDLE_VALUE) {
308 // If this process is being closed, the pipe may be gone already.
309 PLOG(WARNING) << "Unable to create pipe \"" << pipe_name << "\" in "
310 << (mode & MODE_SERVER_FLAG ? "server" : "client") << " mode";
314 // Create the Hello message to be sent when Connect is called
315 scoped_ptr<Message> m(new Message(MSG_ROUTING_NONE,
317 IPC::Message::PRIORITY_NORMAL));
319 // Don't send the secret to the untrusted process, and don't send a secret
320 // if the value is zero (for IPC backwards compatability).
321 int32 secret = validate_client_ ? 0 : client_secret_;
322 if (!m->WriteInt(GetCurrentProcessId()) ||
323 (secret && !m->WriteUInt32(secret))) {
325 pipe_ = INVALID_HANDLE_VALUE;
329 debug_flags_ |= INIT_DONE;
331 output_queue_.push(m.release());
335 bool ChannelWin::Connect() {
336 DLOG_IF(WARNING, thread_check_.get()) << "Connect called more than once";
338 if (!thread_check_.get())
339 thread_check_.reset(new base::ThreadChecker());
341 if (pipe_ == INVALID_HANDLE_VALUE)
344 base::MessageLoopForIO::current()->RegisterIOHandler(pipe_, this);
346 // Check to see if there is a client connected to our pipe...
347 if (waiting_connect_)
350 if (!input_state_.is_pending) {
351 // Complete setup asynchronously. By not setting input_state_.is_pending
352 // to true, we indicate to OnIOCompleted that this is the special
353 // initialization signal.
354 base::MessageLoopForIO::current()->PostTask(
356 base::Bind(&ChannelWin::OnIOCompleted,
357 weak_factory_.GetWeakPtr(),
358 &input_state_.context,
363 if (!waiting_connect_)
364 ProcessOutgoingMessages(NULL, 0);
368 bool ChannelWin::ProcessConnection() {
369 DCHECK(thread_check_->CalledOnValidThread());
370 if (input_state_.is_pending)
371 input_state_.is_pending = false;
373 // Do we have a client connected to our pipe?
374 if (INVALID_HANDLE_VALUE == pipe_)
377 BOOL ok = ConnectNamedPipe(pipe_, &input_state_.context.overlapped);
378 debug_flags_ |= CALLED_CONNECT;
380 DWORD err = GetLastError();
382 // Uhm, the API documentation says that this function should never
383 // return success when used in overlapped mode.
389 case ERROR_IO_PENDING:
390 input_state_.is_pending = true;
391 debug_flags_ |= PENDING_CONNECT;
393 case ERROR_PIPE_CONNECTED:
394 debug_flags_ |= PIPE_CONNECTED;
395 waiting_connect_ = false;
398 // The pipe is being closed.
408 bool ChannelWin::ProcessOutgoingMessages(
409 base::MessageLoopForIO::IOContext* context,
410 DWORD bytes_written) {
411 DCHECK(!waiting_connect_); // Why are we trying to send messages if there's
413 DCHECK(thread_check_->CalledOnValidThread());
415 if (output_state_.is_pending) {
417 output_state_.is_pending = false;
418 if (!context || bytes_written == 0) {
419 DWORD err = GetLastError();
420 LOG(ERROR) << "pipe error: " << err;
424 CHECK(!output_queue_.empty());
425 Message* m = output_queue_.front();
430 if (output_queue_.empty())
433 if (INVALID_HANDLE_VALUE == pipe_)
437 Message* m = output_queue_.front();
438 DCHECK(m->size() <= INT_MAX);
439 debug_flags_ |= WRITE_MSG;
442 BOOL ok = WriteFile(pipe_,
444 static_cast<int>(m->size()),
446 &output_state_.context.overlapped);
448 DWORD err = GetLastError();
449 if (err == ERROR_IO_PENDING) {
450 output_state_.is_pending = true;
452 DVLOG(2) << "sent pending message @" << m << " on channel @" << this
453 << " with type " << m->type();
458 LOG(ERROR) << "pipe error: " << err;
462 DVLOG(2) << "sent message @" << m << " on channel @" << this
463 << " with type " << m->type();
465 output_state_.is_pending = true;
469 void ChannelWin::OnIOCompleted(
470 base::MessageLoopForIO::IOContext* context,
471 DWORD bytes_transfered,
474 DCHECK(thread_check_->CalledOnValidThread());
475 if (context == &input_state_.context) {
476 if (waiting_connect_) {
477 debug_flags_ |= CONNECT_COMPLETED;
478 if (!ProcessConnection())
480 // We may have some messages queued up to send...
481 if (!output_queue_.empty() && !output_state_.is_pending)
482 ProcessOutgoingMessages(NULL, 0);
483 if (input_state_.is_pending)
485 // else, fall-through and look for incoming messages...
488 // We don't support recursion through OnMessageReceived yet!
489 DCHECK(!processing_incoming_);
490 base::AutoReset<bool> auto_reset_processing_incoming(
491 &processing_incoming_, true);
493 // Process the new data.
494 if (input_state_.is_pending) {
495 // This is the normal case for everything except the initialization step.
496 debug_flags_ |= READ_COMPLETED;
497 if (debug_flags_ & WAIT_FOR_READ) {
498 CHECK(!(debug_flags_ & WAIT_FOR_READ_COMPLETE));
499 debug_flags_ |= WAIT_FOR_READ_COMPLETE;
501 input_state_.is_pending = false;
502 if (!bytes_transfered)
504 else if (pipe_ != INVALID_HANDLE_VALUE)
505 ok = AsyncReadComplete(bytes_transfered);
507 DCHECK(!bytes_transfered);
510 // Request more data.
512 ok = ProcessIncomingMessages();
514 DCHECK(context == &output_state_.context);
516 CHECK(output_state_.is_pending);
518 debug_flags_ |= WRITE_COMPLETED;
519 if (debug_flags_ & WAIT_FOR_WRITE) {
520 CHECK(!(debug_flags_ & WAIT_FOR_WRITE_COMPLETE));
521 debug_flags_ |= WAIT_FOR_WRITE_COMPLETE;
523 ok = ProcessOutgoingMessages(context, bytes_transfered);
525 if (!ok && INVALID_HANDLE_VALUE != pipe_) {
526 // We don't want to re-enter Close().
528 listener()->OnChannelError();
532 //------------------------------------------------------------------------------
536 scoped_ptr<Channel> Channel::Create(
537 const IPC::ChannelHandle &channel_handle, Mode mode, Listener* listener) {
538 return scoped_ptr<Channel>(
539 new ChannelWin(channel_handle, mode, listener));
543 bool Channel::IsNamedServerInitialized(const std::string& channel_id) {
544 return ChannelWin::IsNamedServerInitialized(channel_id);
548 std::string Channel::GenerateVerifiedChannelID(const std::string& prefix) {
549 // Windows pipes can be enumerated by low-privileged processes. So, we
550 // append a strong random value after the \ character. This value is not
551 // included in the pipe name, but sent as part of the client hello, to
552 // hijacking the pipe name to spoof the client.
554 std::string id = prefix;
559 do { // Guarantee we get a non-zero value.
560 secret = base::RandInt(0, std::numeric_limits<int>::max());
561 } while (secret == 0);
563 id.append(GenerateUniqueRandomChannelID());
564 return id.append(base::StringPrintf("\\%d", secret));