ipc/ipc_channel_win.cc

   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 #include "ipc/ipc_channel_win.h"
   6
   7 #include <windows.h>
   8
   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"
  23
  24 namespace {
  25
  26 enum DebugFlags {
  27   INIT_DONE = 1 << 0,
  28   CALLED_CONNECT = 1 << 1,
  29   PENDING_CONNECT = 1 << 2,
  30   CONNECT_COMPLETED = 1 << 3,
  31   PIPE_CONNECTED = 1 << 4,
  32   WRITE_MSG = 1 << 5,
  33   READ_MSG = 1 << 6,
  34   WRITE_COMPLETED = 1 << 7,
  35   READ_COMPLETED = 1 << 8,
  36   CLOSED = 1 << 9,
  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
  41 };
  42
  43 }  // namespace
  44
  45 namespace IPC {
  46
  47 ChannelWin::State::State(ChannelWin* channel) : is_pending(false) {
  48   memset(&context.overlapped, 0, sizeof(context.overlapped));
  49   context.handler = channel;
  50 }
  51
  52 ChannelWin::State::~State() {
  53   COMPILE_ASSERT(!offsetof(ChannelWin::State, context),
  54                  starts_with_io_context);
  55 }
  56
  57 ChannelWin::ChannelWin(const IPC::ChannelHandle &channel_handle,
  58                        Mode mode, Listener* listener)
  59     : ChannelReader(listener),
  60       input_state_(this),
  61       output_state_(this),
  62       peer_pid_(base::kNullProcessId),
  63       waiting_connect_(mode & MODE_SERVER_FLAG),
  64       processing_incoming_(false),
  65       validate_client_(false),
  66       writing_(false),
  67       debug_flags_(0),
  68       write_error_(0),
  69       last_write_error_(0),
  70       write_size_(0),
  71       client_secret_(0),
  72       weak_factory_(this) {
  73   CreatePipe(channel_handle, mode);
  74 }
  75
  76 ChannelWin::~ChannelWin() {
  77   Close();
  78 }
  79
  80 void ChannelWin::Close() {
  81   if (thread_check_.get()) {
  82     DCHECK(thread_check_->CalledOnValidThread());
  83   }
  84   debug_flags_ |= CLOSED;
  85
  86   if (input_state_.is_pending || output_state_.is_pending)
  87     CancelIo(pipe_.Get());
  88
  89   // Closing the handle at this point prevents us from issuing more requests
  90   // form OnIOCompleted().
  91   if (pipe_.IsValid())
  92     pipe_.Close();
  93
  94   if (input_state_.is_pending)
  95     debug_flags_ |= WAIT_FOR_READ;
  96
  97   if (output_state_.is_pending)
  98     debug_flags_ |= WAIT_FOR_WRITE;
  99
 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);
 104   }
 105
 106   while (!output_queue_.empty()) {
 107     Message* m = output_queue_.front();
 108     output_queue_.pop();
 109     delete m;
 110   }
 111 }
 112
 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)";
 118
 119 #ifdef IPC_MESSAGE_LOG_ENABLED
 120   Logging::GetInstance()->OnSendMessage(message, "");
 121 #endif
 122
 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))
 129         return false;
 130     }
 131   }
 132
 133   return true;
 134 }
 135
 136 base::ProcessId ChannelWin::GetPeerPID() const {
 137   return peer_pid_;
 138 }
 139
 140 base::ProcessId ChannelWin::GetSelfPID() const {
 141   return GetCurrentProcessId();
 142 }
 143
 144 // static
 145 bool ChannelWin::IsNamedServerInitialized(
 146     const std::string& channel_id) {
 147   if (WaitNamedPipe(PipeName(channel_id, NULL).c_str(), 1))
 148     return true;
 149   // If ERROR_SEM_TIMEOUT occurred, the pipe exists but is handling another
 150   // connection.
 151   return GetLastError() == ERROR_SEM_TIMEOUT;
 152 }
 153
 154 ChannelWin::ReadState ChannelWin::ReadData(
 155     char* buffer,
 156     int buffer_len,
 157     int* /* bytes_read */) {
 158   if (!pipe_.IsValid())
 159     return READ_FAILED;
 160
 161   debug_flags_ |= READ_MSG;
 162   DWORD bytes_read = 0;
 163   BOOL ok = ReadFile(pipe_.Get(), buffer, buffer_len,
 164                      &bytes_read, &input_state_.context.overlapped);
 165   if (!ok) {
 166     DWORD err = GetLastError();
 167     if (err == ERROR_IO_PENDING) {
 168       input_state_.is_pending = true;
 169       return READ_PENDING;
 170     }
 171     LOG(ERROR) << "pipe error: " << err;
 172     return READ_FAILED;
 173   }
 174
 175   // We could return READ_SUCCEEDED here. But the way that this code is
 176   // structured we instead go back to the message loop. Our completion port
 177   // will be signalled even in the "synchronously completed" state.
 178   //
 179   // This allows us to potentially process some outgoing messages and
 180   // interleave other work on this thread when we're getting hammered with
 181   // input messages. Potentially, this could be tuned to be more efficient
 182   // with some testing.
 183   input_state_.is_pending = true;
 184   return READ_PENDING;
 185 }
 186
 187 bool ChannelWin::WillDispatchInputMessage(Message* msg) {
 188   // Make sure we get a hello when client validation is required.
 189   if (validate_client_)
 190     return IsHelloMessage(*msg);
 191   return true;
 192 }
 193
 194 void ChannelWin::HandleInternalMessage(const Message& msg) {
 195   DCHECK_EQ(msg.type(), static_cast<unsigned>(Channel::HELLO_MESSAGE_TYPE));
 196   // The hello message contains one parameter containing the PID.
 197   PickleIterator it(msg);
 198   int32 claimed_pid;
 199   bool failed = !it.ReadInt(&claimed_pid);
 200
 201   if (!failed && validate_client_) {
 202     int32 secret;
 203     failed = it.ReadInt(&secret) ? (secret != client_secret_) : true;
 204   }
 205
 206   if (failed) {
 207     NOTREACHED();
 208     Close();
 209     listener()->OnChannelError();
 210     return;
 211   }
 212
 213   peer_pid_ = claimed_pid;
 214   // Validation completed.
 215   validate_client_ = false;
 216   listener()->OnChannelConnected(claimed_pid);
 217 }
 218
 219 bool ChannelWin::DidEmptyInputBuffers() {
 220   // We don't need to do anything here.
 221   return true;
 222 }
 223
 224 // static
 225 const base::string16 ChannelWin::PipeName(
 226     const std::string& channel_id, int32* secret) {
 227   std::string name("\\\\.\\pipe\\chrome.");
 228
 229   // Prevent the shared secret from ending up in the pipe name.
 230   size_t index = channel_id.find_first_of('\\');
 231   if (index != std::string::npos) {
 232     if (secret)  // Retrieve the secret if asked for.
 233       base::StringToInt(channel_id.substr(index + 1), secret);
 234     return base::ASCIIToWide(name.append(channel_id.substr(0, index - 1)));
 235   }
 236
 237   // This case is here to support predictable named pipes in tests.
 238   if (secret)
 239     *secret = 0;
 240   return base::ASCIIToWide(name.append(channel_id));
 241 }
 242
 243 bool ChannelWin::CreatePipe(const IPC::ChannelHandle &channel_handle,
 244                             Mode mode) {
 245   DCHECK(!pipe_.IsValid());
 246   base::string16 pipe_name;
 247   // If we already have a valid pipe for channel just copy it.
 248   if (channel_handle.pipe.handle) {
 249     // TODO(rvargas) crbug.com/415294: ChannelHandle should either go away in
 250     // favor of two independent entities (name/file), or it should be a move-
 251     // only type with a base::File member. In any case, this code should not
 252     // call DuplicateHandle.
 253     DCHECK(channel_handle.name.empty());
 254     pipe_name = L"Not Available";  // Just used for LOG
 255     // Check that the given pipe confirms to the specified mode.  We can
 256     // only check for PIPE_TYPE_MESSAGE & PIPE_SERVER_END flags since the
 257     // other flags (PIPE_TYPE_BYTE, and PIPE_CLIENT_END) are defined as 0.
 258     DWORD flags = 0;
 259     GetNamedPipeInfo(channel_handle.pipe.handle, &flags, NULL, NULL, NULL);
 260     DCHECK(!(flags & PIPE_TYPE_MESSAGE));
 261     if (((mode & MODE_SERVER_FLAG) && !(flags & PIPE_SERVER_END)) ||
 262         ((mode & MODE_CLIENT_FLAG) && (flags & PIPE_SERVER_END))) {
 263       LOG(WARNING) << "Inconsistent open mode. Mode :" << mode;
 264       return false;
 265     }
 266     HANDLE local_handle;
 267     if (!DuplicateHandle(GetCurrentProcess(),
 268                          channel_handle.pipe.handle,
 269                          GetCurrentProcess(),
 270                          &local_handle,
 271                          0,
 272                          FALSE,
 273                          DUPLICATE_SAME_ACCESS)) {
 274       LOG(WARNING) << "DuplicateHandle failed. Error :" << GetLastError();
 275       return false;
 276     }
 277     pipe_.Set(local_handle);
 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_.Set(CreateNamedPipeW(pipe_name.c_str(),
 285                                open_mode,
 286                                PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
 287                                1,
 288                                Channel::kReadBufferSize,
 289                                Channel::kReadBufferSize,
 290                                5000,
 291                                NULL));
 292   } else if (mode & MODE_CLIENT_FLAG) {
 293     DCHECK(!channel_handle.pipe.handle);
 294     pipe_name = PipeName(channel_handle.name, &client_secret_);
 295     pipe_.Set(CreateFileW(pipe_name.c_str(),
 296                           GENERIC_READ | GENERIC_WRITE,
 297                           0,
 298                           NULL,
 299                           OPEN_EXISTING,
 300                           SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION |
 301                               FILE_FLAG_OVERLAPPED,
 302                           NULL));
 303   } else {
 304     NOTREACHED();
 305   }
 306
 307   if (!pipe_.IsValid()) {
 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";
 311     return false;
 312   }
 313
 314   // Create the Hello message to be sent when Connect is called
 315   scoped_ptr<Message> m(new Message(MSG_ROUTING_NONE,
 316                                     HELLO_MESSAGE_TYPE,
 317                                     IPC::Message::PRIORITY_NORMAL));
 318
 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))) {
 324     pipe_.Close();
 325     return false;
 326   }
 327
 328   debug_flags_ |= INIT_DONE;
 329
 330   output_queue_.push(m.release());
 331   return true;
 332 }
 333
 334 bool ChannelWin::Connect() {
 335   DLOG_IF(WARNING, thread_check_.get()) << "Connect called more than once";
 336
 337   if (!thread_check_.get())
 338     thread_check_.reset(new base::ThreadChecker());
 339
 340   if (!pipe_.IsValid())
 341     return false;
 342
 343   base::MessageLoopForIO::current()->RegisterIOHandler(pipe_.Get(), this);
 344
 345   // Check to see if there is a client connected to our pipe...
 346   if (waiting_connect_)
 347     ProcessConnection();
 348
 349   if (!input_state_.is_pending) {
 350     // Complete setup asynchronously. By not setting input_state_.is_pending
 351     // to true, we indicate to OnIOCompleted that this is the special
 352     // initialization signal.
 353     base::MessageLoopForIO::current()->PostTask(
 354         FROM_HERE,
 355         base::Bind(&ChannelWin::OnIOCompleted,
 356                    weak_factory_.GetWeakPtr(),
 357                    &input_state_.context,
 358                    0,
 359                    0));
 360   }
 361
 362   if (!waiting_connect_)
 363     ProcessOutgoingMessages(NULL, 0);
 364   return true;
 365 }
 366
 367 bool ChannelWin::ProcessConnection() {
 368   DCHECK(thread_check_->CalledOnValidThread());
 369   if (input_state_.is_pending)
 370     input_state_.is_pending = false;
 371
 372   // Do we have a client connected to our pipe?
 373   if (!pipe_.IsValid())
 374     return false;
 375
 376   BOOL ok = ConnectNamedPipe(pipe_.Get(), &input_state_.context.overlapped);
 377   debug_flags_ |= CALLED_CONNECT;
 378
 379   DWORD err = GetLastError();
 380   if (ok) {
 381     // Uhm, the API documentation says that this function should never
 382     // return success when used in overlapped mode.
 383     NOTREACHED();
 384     return false;
 385   }
 386
 387   switch (err) {
 388   case ERROR_IO_PENDING:
 389     input_state_.is_pending = true;
 390     debug_flags_ |= PENDING_CONNECT;
 391     break;
 392   case ERROR_PIPE_CONNECTED:
 393     debug_flags_ |= PIPE_CONNECTED;
 394     waiting_connect_ = false;
 395     break;
 396   case ERROR_NO_DATA:
 397     // The pipe is being closed.
 398     return false;
 399   default:
 400     NOTREACHED();
 401     return false;
 402   }
 403
 404   return true;
 405 }
 406
 407 bool ChannelWin::ProcessOutgoingMessages(
 408     base::MessageLoopForIO::IOContext* context,
 409     DWORD bytes_written) {
 410   DCHECK(!waiting_connect_);  // Why are we trying to send messages if there's
 411                               // no connection?
 412   DCHECK(thread_check_->CalledOnValidThread());
 413
 414   if (output_state_.is_pending) {
 415     DCHECK(context);
 416     output_state_.is_pending = false;
 417     if (!context || bytes_written == 0) {
 418       DWORD err = GetLastError();
 419       LOG(ERROR) << "pipe error: " << err;
 420       return false;
 421     }
 422     // Message was sent.
 423     CHECK(!output_queue_.empty());
 424     Message* m = output_queue_.front();
 425     output_queue_.pop();
 426     delete m;
 427   }
 428
 429   if (output_queue_.empty())
 430     return true;
 431
 432   if (!pipe_.IsValid())
 433     return false;
 434
 435   // Write to pipe...
 436   Message* m = output_queue_.front();
 437   DCHECK(m->size() <= INT_MAX);
 438   debug_flags_ |= WRITE_MSG;
 439   CHECK(!writing_);
 440   writing_ = true;
 441   write_size_ = static_cast<uint32>(m->size());
 442   write_error_ = 0;
 443   BOOL ok = WriteFile(pipe_.Get(),
 444                       m->data(),
 445                       write_size_,
 446                       NULL,
 447                       &output_state_.context.overlapped);
 448   if (!ok) {
 449     write_error_ = GetLastError();
 450     if (write_error_ == ERROR_IO_PENDING) {
 451       output_state_.is_pending = true;
 452
 453       DVLOG(2) << "sent pending message @" << m << " on channel @" << this
 454                << " with type " << m->type();
 455
 456       return true;
 457     }
 458     writing_ = false;
 459     last_write_error_ = write_error_;
 460     LOG(ERROR) << "pipe error: " << write_error_;
 461     return false;
 462   }
 463
 464   DVLOG(2) << "sent message @" << m << " on channel @" << this
 465            << " with type " << m->type();
 466
 467   output_state_.is_pending = true;
 468   return true;
 469 }
 470
 471 void ChannelWin::OnIOCompleted(
 472     base::MessageLoopForIO::IOContext* context,
 473     DWORD bytes_transfered,
 474     DWORD error) {
 475   bool ok = true;
 476   DCHECK(thread_check_->CalledOnValidThread());
 477   if (context == &input_state_.context) {
 478     if (waiting_connect_) {
 479       debug_flags_ |= CONNECT_COMPLETED;
 480       if (!ProcessConnection())
 481         return;
 482       // We may have some messages queued up to send...
 483       if (!output_queue_.empty() && !output_state_.is_pending)
 484         ProcessOutgoingMessages(NULL, 0);
 485       if (input_state_.is_pending)
 486         return;
 487       // else, fall-through and look for incoming messages...
 488     }
 489
 490     // We don't support recursion through OnMessageReceived yet!
 491     DCHECK(!processing_incoming_);
 492     base::AutoReset<bool> auto_reset_processing_incoming(
 493         &processing_incoming_, true);
 494
 495     // Process the new data.
 496     if (input_state_.is_pending) {
 497       // This is the normal case for everything except the initialization step.
 498       debug_flags_ |= READ_COMPLETED;
 499       if (debug_flags_ & WAIT_FOR_READ) {
 500         CHECK(!(debug_flags_ & WAIT_FOR_READ_COMPLETE));
 501         debug_flags_ |= WAIT_FOR_READ_COMPLETE;
 502       }
 503       input_state_.is_pending = false;
 504       if (!bytes_transfered)
 505         ok = false;
 506       else if (pipe_.IsValid())
 507         ok = AsyncReadComplete(bytes_transfered);
 508     } else {
 509       DCHECK(!bytes_transfered);
 510     }
 511
 512     // Request more data.
 513     if (ok)
 514       ok = ProcessIncomingMessages();
 515   } else {
 516     DCHECK(context == &output_state_.context);
 517     CHECK(writing_);
 518     CHECK(output_state_.is_pending);
 519     writing_ = false;
 520     debug_flags_ |= WRITE_COMPLETED;
 521     if (debug_flags_ & WAIT_FOR_WRITE) {
 522       CHECK(!(debug_flags_ & WAIT_FOR_WRITE_COMPLETE));
 523       debug_flags_ |= WAIT_FOR_WRITE_COMPLETE;
 524     }
 525     ok = ProcessOutgoingMessages(context, bytes_transfered);
 526   }
 527   if (!ok && pipe_.IsValid()) {
 528     // We don't want to re-enter Close().
 529     Close();
 530     listener()->OnChannelError();
 531   }
 532 }
 533
 534 //------------------------------------------------------------------------------
 535 // Channel's methods
 536
 537 // static
 538 scoped_ptr<Channel> Channel::Create(
 539     const IPC::ChannelHandle &channel_handle, Mode mode, Listener* listener) {
 540   return scoped_ptr<Channel>(
 541       new ChannelWin(channel_handle, mode, listener));
 542 }
 543
 544 // static
 545 bool Channel::IsNamedServerInitialized(const std::string& channel_id) {
 546   return ChannelWin::IsNamedServerInitialized(channel_id);
 547 }
 548
 549 // static
 550 std::string Channel::GenerateVerifiedChannelID(const std::string& prefix) {
 551   // Windows pipes can be enumerated by low-privileged processes. So, we
 552   // append a strong random value after the \ character. This value is not
 553   // included in the pipe name, but sent as part of the client hello, to
 554   // hijacking the pipe name to spoof the client.
 555
 556   std::string id = prefix;
 557   if (!id.empty())
 558     id.append(".");
 559
 560   int secret;
 561   do {  // Guarantee we get a non-zero value.
 562     secret = base::RandInt(0, std::numeric_limits<int>::max());
 563   } while (secret == 0);
 564
 565   id.append(GenerateUniqueRandomChannelID());
 566   return id.append(base::StringPrintf("\\%d", secret));
 567 }
 568
 569 }  // namespace IPC