net/socket/tcp_socket_win.cc

   1 // Copyright 2013 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 "net/socket/tcp_socket_win.h"
   6
   7 #include <mstcpip.h>
   8
   9 #include "base/callback_helpers.h"
  10 #include "base/logging.h"
  11 #include "base/metrics/stats_counters.h"
  12 #include "base/win/windows_version.h"
  13 #include "net/base/address_list.h"
  14 #include "net/base/connection_type_histograms.h"
  15 #include "net/base/io_buffer.h"
  16 #include "net/base/ip_endpoint.h"
  17 #include "net/base/net_errors.h"
  18 #include "net/base/net_util.h"
  19 #include "net/base/network_change_notifier.h"
  20 #include "net/base/winsock_init.h"
  21 #include "net/base/winsock_util.h"
  22 #include "net/socket/socket_descriptor.h"
  23 #include "net/socket/socket_net_log_params.h"
  24
  25 namespace net {
  26
  27 namespace {
  28
  29 const int kTCPKeepAliveSeconds = 45;
  30
  31 int SetSocketReceiveBufferSize(SOCKET socket, int32 size) {
  32   int rv = setsockopt(socket, SOL_SOCKET, SO_RCVBUF,
  33                       reinterpret_cast<const char*>(&size), sizeof(size));
  34   int net_error = (rv == 0) ? OK : MapSystemError(WSAGetLastError());
  35   DCHECK(!rv) << "Could not set socket receive buffer size: " << net_error;
  36   return net_error;
  37 }
  38
  39 int SetSocketSendBufferSize(SOCKET socket, int32 size) {
  40   int rv = setsockopt(socket, SOL_SOCKET, SO_SNDBUF,
  41                       reinterpret_cast<const char*>(&size), sizeof(size));
  42   int net_error = (rv == 0) ? OK : MapSystemError(WSAGetLastError());
  43   DCHECK(!rv) << "Could not set socket send buffer size: " << net_error;
  44   return net_error;
  45 }
  46
  47 // Disable Nagle.
  48 // The Nagle implementation on windows is governed by RFC 896.  The idea
  49 // behind Nagle is to reduce small packets on the network.  When Nagle is
  50 // enabled, if a partial packet has been sent, the TCP stack will disallow
  51 // further *partial* packets until an ACK has been received from the other
  52 // side.  Good applications should always strive to send as much data as
  53 // possible and avoid partial-packet sends.  However, in most real world
  54 // applications, there are edge cases where this does not happen, and two
  55 // partial packets may be sent back to back.  For a browser, it is NEVER
  56 // a benefit to delay for an RTT before the second packet is sent.
  57 //
  58 // As a practical example in Chromium today, consider the case of a small
  59 // POST.  I have verified this:
  60 //     Client writes 649 bytes of header  (partial packet #1)
  61 //     Client writes 50 bytes of POST data (partial packet #2)
  62 // In the above example, with Nagle, a RTT delay is inserted between these
  63 // two sends due to nagle.  RTTs can easily be 100ms or more.  The best
  64 // fix is to make sure that for POSTing data, we write as much data as
  65 // possible and minimize partial packets.  We will fix that.  But disabling
  66 // Nagle also ensure we don't run into this delay in other edge cases.
  67 // See also:
  68 //    http://technet.microsoft.com/en-us/library/bb726981.aspx
  69 bool DisableNagle(SOCKET socket, bool disable) {
  70   BOOL val = disable ? TRUE : FALSE;
  71   int rv = setsockopt(socket, IPPROTO_TCP, TCP_NODELAY,
  72                       reinterpret_cast<const char*>(&val),
  73                       sizeof(val));
  74   DCHECK(!rv) << "Could not disable nagle";
  75   return rv == 0;
  76 }
  77
  78 // Enable TCP Keep-Alive to prevent NAT routers from timing out TCP
  79 // connections. See http://crbug.com/27400 for details.
  80 bool SetTCPKeepAlive(SOCKET socket, BOOL enable, int delay_secs) {
  81   int delay = delay_secs * 1000;
  82   struct tcp_keepalive keepalive_vals = {
  83     enable ? 1 : 0,  // TCP keep-alive on.
  84     delay,  // Delay seconds before sending first TCP keep-alive packet.
  85     delay,  // Delay seconds between sending TCP keep-alive packets.
  86   };
  87   DWORD bytes_returned = 0xABAB;
  88   int rv = WSAIoctl(socket, SIO_KEEPALIVE_VALS, &keepalive_vals,
  89                     sizeof(keepalive_vals), NULL, 0,
  90                     &bytes_returned, NULL, NULL);
  91   DCHECK(!rv) << "Could not enable TCP Keep-Alive for socket: " << socket
  92               << " [error: " << WSAGetLastError() << "].";
  93
  94   // Disregard any failure in disabling nagle or enabling TCP Keep-Alive.
  95   return rv == 0;
  96 }
  97
  98 int MapConnectError(int os_error) {
  99   switch (os_error) {
 100     // connect fails with WSAEACCES when Windows Firewall blocks the
 101     // connection.
 102     case WSAEACCES:
 103       return ERR_NETWORK_ACCESS_DENIED;
 104     case WSAETIMEDOUT:
 105       return ERR_CONNECTION_TIMED_OUT;
 106     default: {
 107       int net_error = MapSystemError(os_error);
 108       if (net_error == ERR_FAILED)
 109         return ERR_CONNECTION_FAILED;  // More specific than ERR_FAILED.
 110
 111       // Give a more specific error when the user is offline.
 112       if (net_error == ERR_ADDRESS_UNREACHABLE &&
 113           NetworkChangeNotifier::IsOffline()) {
 114         return ERR_INTERNET_DISCONNECTED;
 115       }
 116
 117       return net_error;
 118     }
 119   }
 120 }
 121
 122 }  // namespace
 123
 124 //-----------------------------------------------------------------------------
 125
 126 // This class encapsulates all the state that has to be preserved as long as
 127 // there is a network IO operation in progress. If the owner TCPSocketWin is
 128 // destroyed while an operation is in progress, the Core is detached and it
 129 // lives until the operation completes and the OS doesn't reference any resource
 130 // declared on this class anymore.
 131 class TCPSocketWin::Core : public base::RefCounted<Core> {
 132  public:
 133   explicit Core(TCPSocketWin* socket);
 134
 135   // Start watching for the end of a read or write operation.
 136   void WatchForRead();
 137   void WatchForWrite();
 138
 139   // The TCPSocketWin is going away.
 140   void Detach() { socket_ = NULL; }
 141
 142   // The separate OVERLAPPED variables for asynchronous operation.
 143   // |read_overlapped_| is used for both Connect() and Read().
 144   // |write_overlapped_| is only used for Write();
 145   OVERLAPPED read_overlapped_;
 146   OVERLAPPED write_overlapped_;
 147
 148   // The buffers used in Read() and Write().
 149   scoped_refptr<IOBuffer> read_iobuffer_;
 150   scoped_refptr<IOBuffer> write_iobuffer_;
 151   int read_buffer_length_;
 152   int write_buffer_length_;
 153
 154   bool non_blocking_reads_initialized_;
 155
 156  private:
 157   friend class base::RefCounted<Core>;
 158
 159   class ReadDelegate : public base::win::ObjectWatcher::Delegate {
 160    public:
 161     explicit ReadDelegate(Core* core) : core_(core) {}
 162     virtual ~ReadDelegate() {}
 163
 164     // base::ObjectWatcher::Delegate methods:
 165     virtual void OnObjectSignaled(HANDLE object);
 166
 167    private:
 168     Core* const core_;
 169   };
 170
 171   class WriteDelegate : public base::win::ObjectWatcher::Delegate {
 172    public:
 173     explicit WriteDelegate(Core* core) : core_(core) {}
 174     virtual ~WriteDelegate() {}
 175
 176     // base::ObjectWatcher::Delegate methods:
 177     virtual void OnObjectSignaled(HANDLE object);
 178
 179    private:
 180     Core* const core_;
 181   };
 182
 183   ~Core();
 184
 185   // The socket that created this object.
 186   TCPSocketWin* socket_;
 187
 188   // |reader_| handles the signals from |read_watcher_|.
 189   ReadDelegate reader_;
 190   // |writer_| handles the signals from |write_watcher_|.
 191   WriteDelegate writer_;
 192
 193   // |read_watcher_| watches for events from Connect() and Read().
 194   base::win::ObjectWatcher read_watcher_;
 195   // |write_watcher_| watches for events from Write();
 196   base::win::ObjectWatcher write_watcher_;
 197
 198   DISALLOW_COPY_AND_ASSIGN(Core);
 199 };
 200
 201 TCPSocketWin::Core::Core(TCPSocketWin* socket)
 202     : read_buffer_length_(0),
 203       write_buffer_length_(0),
 204       non_blocking_reads_initialized_(false),
 205       socket_(socket),
 206       reader_(this),
 207       writer_(this) {
 208   memset(&read_overlapped_, 0, sizeof(read_overlapped_));
 209   memset(&write_overlapped_, 0, sizeof(write_overlapped_));
 210
 211   read_overlapped_.hEvent = WSACreateEvent();
 212   write_overlapped_.hEvent = WSACreateEvent();
 213 }
 214
 215 TCPSocketWin::Core::~Core() {
 216   // Make sure the message loop is not watching this object anymore.
 217   read_watcher_.StopWatching();
 218   write_watcher_.StopWatching();
 219
 220   WSACloseEvent(read_overlapped_.hEvent);
 221   memset(&read_overlapped_, 0xaf, sizeof(read_overlapped_));
 222   WSACloseEvent(write_overlapped_.hEvent);
 223   memset(&write_overlapped_, 0xaf, sizeof(write_overlapped_));
 224 }
 225
 226 void TCPSocketWin::Core::WatchForRead() {
 227   // We grab an extra reference because there is an IO operation in progress.
 228   // Balanced in ReadDelegate::OnObjectSignaled().
 229   AddRef();
 230   read_watcher_.StartWatching(read_overlapped_.hEvent, &reader_);
 231 }
 232
 233 void TCPSocketWin::Core::WatchForWrite() {
 234   // We grab an extra reference because there is an IO operation in progress.
 235   // Balanced in WriteDelegate::OnObjectSignaled().
 236   AddRef();
 237   write_watcher_.StartWatching(write_overlapped_.hEvent, &writer_);
 238 }
 239
 240 void TCPSocketWin::Core::ReadDelegate::OnObjectSignaled(HANDLE object) {
 241   DCHECK_EQ(object, core_->read_overlapped_.hEvent);
 242   if (core_->socket_) {
 243     if (core_->socket_->waiting_connect_)
 244       core_->socket_->DidCompleteConnect();
 245     else
 246       core_->socket_->DidSignalRead();
 247   }
 248
 249   core_->Release();
 250 }
 251
 252 void TCPSocketWin::Core::WriteDelegate::OnObjectSignaled(
 253     HANDLE object) {
 254   DCHECK_EQ(object, core_->write_overlapped_.hEvent);
 255   if (core_->socket_)
 256     core_->socket_->DidCompleteWrite();
 257
 258   core_->Release();
 259 }
 260
 261 //-----------------------------------------------------------------------------
 262
 263 TCPSocketWin::TCPSocketWin(net::NetLog* net_log,
 264                            const net::NetLog::Source& source)
 265     : socket_(INVALID_SOCKET),
 266       accept_event_(WSA_INVALID_EVENT),
 267       accept_socket_(NULL),
 268       accept_address_(NULL),
 269       waiting_connect_(false),
 270       waiting_read_(false),
 271       waiting_write_(false),
 272       connect_os_error_(0),
 273       logging_multiple_connect_attempts_(false),
 274       net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_SOCKET)) {
 275   net_log_.BeginEvent(NetLog::TYPE_SOCKET_ALIVE,
 276                       source.ToEventParametersCallback());
 277   EnsureWinsockInit();
 278 }
 279
 280 TCPSocketWin::~TCPSocketWin() {
 281   Close();
 282   net_log_.EndEvent(NetLog::TYPE_SOCKET_ALIVE);
 283 }
 284
 285 int TCPSocketWin::Open(AddressFamily family) {
 286   DCHECK(CalledOnValidThread());
 287   DCHECK_EQ(socket_, INVALID_SOCKET);
 288
 289   socket_ = CreatePlatformSocket(ConvertAddressFamily(family), SOCK_STREAM,
 290                                  IPPROTO_TCP);
 291   if (socket_ == INVALID_SOCKET) {
 292     PLOG(ERROR) << "CreatePlatformSocket() returned an error";
 293     return MapSystemError(WSAGetLastError());
 294   }
 295
 296   if (SetNonBlocking(socket_)) {
 297     int result = MapSystemError(WSAGetLastError());
 298     Close();
 299     return result;
 300   }
 301
 302   return OK;
 303 }
 304
 305 int TCPSocketWin::AdoptConnectedSocket(SOCKET socket,
 306                                        const IPEndPoint& peer_address) {
 307   DCHECK(CalledOnValidThread());
 308   DCHECK_EQ(socket_, INVALID_SOCKET);
 309   DCHECK(!core_);
 310
 311   socket_ = socket;
 312
 313   if (SetNonBlocking(socket_)) {
 314     int result = MapSystemError(WSAGetLastError());
 315     Close();
 316     return result;
 317   }
 318
 319   core_ = new Core(this);
 320   peer_address_.reset(new IPEndPoint(peer_address));
 321
 322   return OK;
 323 }
 324
 325 int TCPSocketWin::AdoptListenSocket(SOCKET socket) {
 326   DCHECK(CalledOnValidThread());
 327   DCHECK_EQ(socket_, INVALID_SOCKET);
 328
 329   socket_ = socket;
 330
 331   if (SetNonBlocking(socket_)) {
 332     int result = MapSystemError(WSAGetLastError());
 333     Close();
 334     return result;
 335   }
 336
 337   // |core_| is not needed for sockets that are used to accept connections.
 338   // The operation here is more like Open but with an existing socket.
 339
 340   return OK;
 341 }
 342
 343 int TCPSocketWin::Bind(const IPEndPoint& address) {
 344   DCHECK(CalledOnValidThread());
 345   DCHECK_NE(socket_, INVALID_SOCKET);
 346
 347   SockaddrStorage storage;
 348   if (!address.ToSockAddr(storage.addr, &storage.addr_len))
 349     return ERR_ADDRESS_INVALID;
 350
 351   int result = bind(socket_, storage.addr, storage.addr_len);
 352   if (result < 0) {
 353     PLOG(ERROR) << "bind() returned an error";
 354     return MapSystemError(WSAGetLastError());
 355   }
 356
 357   return OK;
 358 }
 359
 360 int TCPSocketWin::Listen(int backlog) {
 361   DCHECK(CalledOnValidThread());
 362   DCHECK_GT(backlog, 0);
 363   DCHECK_NE(socket_, INVALID_SOCKET);
 364   DCHECK_EQ(accept_event_, WSA_INVALID_EVENT);
 365
 366   accept_event_ = WSACreateEvent();
 367   if (accept_event_ == WSA_INVALID_EVENT) {
 368     PLOG(ERROR) << "WSACreateEvent()";
 369     return MapSystemError(WSAGetLastError());
 370   }
 371
 372   int result = listen(socket_, backlog);
 373   if (result < 0) {
 374     PLOG(ERROR) << "listen() returned an error";
 375     return MapSystemError(WSAGetLastError());
 376   }
 377
 378   return OK;
 379 }
 380
 381 int TCPSocketWin::Accept(scoped_ptr<TCPSocketWin>* socket,
 382                          IPEndPoint* address,
 383                          const CompletionCallback& callback) {
 384   DCHECK(CalledOnValidThread());
 385   DCHECK(socket);
 386   DCHECK(address);
 387   DCHECK(!callback.is_null());
 388   DCHECK(accept_callback_.is_null());
 389
 390   net_log_.BeginEvent(NetLog::TYPE_TCP_ACCEPT);
 391
 392   int result = AcceptInternal(socket, address);
 393
 394   if (result == ERR_IO_PENDING) {
 395     // Start watching.
 396     WSAEventSelect(socket_, accept_event_, FD_ACCEPT);
 397     accept_watcher_.StartWatching(accept_event_, this);
 398
 399     accept_socket_ = socket;
 400     accept_address_ = address;
 401     accept_callback_ = callback;
 402   }
 403
 404   return result;
 405 }
 406
 407 int TCPSocketWin::Connect(const IPEndPoint& address,
 408                           const CompletionCallback& callback) {
 409   DCHECK(CalledOnValidThread());
 410   DCHECK_NE(socket_, INVALID_SOCKET);
 411   DCHECK(!waiting_connect_);
 412
 413   // |peer_address_| and |core_| will be non-NULL if Connect() has been called.
 414   // Unless Close() is called to reset the internal state, a second call to
 415   // Connect() is not allowed.
 416   // Please note that we enforce this even if the previous Connect() has
 417   // completed and failed. Although it is allowed to connect the same |socket_|
 418   // again after a connection attempt failed on Windows, it results in
 419   // unspecified behavior according to POSIX. Therefore, we make it behave in
 420   // the same way as TCPSocketLibevent.
 421   DCHECK(!peer_address_ && !core_);
 422
 423   if (!logging_multiple_connect_attempts_)
 424     LogConnectBegin(AddressList(address));
 425
 426   peer_address_.reset(new IPEndPoint(address));
 427
 428   int rv = DoConnect();
 429   if (rv == ERR_IO_PENDING) {
 430     // Synchronous operation not supported.
 431     DCHECK(!callback.is_null());
 432     read_callback_ = callback;
 433     waiting_connect_ = true;
 434   } else {
 435     DoConnectComplete(rv);
 436   }
 437
 438   return rv;
 439 }
 440
 441 bool TCPSocketWin::IsConnected() const {
 442   DCHECK(CalledOnValidThread());
 443
 444   if (socket_ == INVALID_SOCKET || waiting_connect_)
 445     return false;
 446
 447   if (waiting_read_)
 448     return true;
 449
 450   // Check if connection is alive.
 451   char c;
 452   int rv = recv(socket_, &c, 1, MSG_PEEK);
 453   if (rv == 0)
 454     return false;
 455   if (rv == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK)
 456     return false;
 457
 458   return true;
 459 }
 460
 461 bool TCPSocketWin::IsConnectedAndIdle() const {
 462   DCHECK(CalledOnValidThread());
 463
 464   if (socket_ == INVALID_SOCKET || waiting_connect_)
 465     return false;
 466
 467   if (waiting_read_)
 468     return true;
 469
 470   // Check if connection is alive and we haven't received any data
 471   // unexpectedly.
 472   char c;
 473   int rv = recv(socket_, &c, 1, MSG_PEEK);
 474   if (rv >= 0)
 475     return false;
 476   if (WSAGetLastError() != WSAEWOULDBLOCK)
 477     return false;
 478
 479   return true;
 480 }
 481
 482 int TCPSocketWin::Read(IOBuffer* buf,
 483                        int buf_len,
 484                        const CompletionCallback& callback) {
 485   DCHECK(CalledOnValidThread());
 486   DCHECK_NE(socket_, INVALID_SOCKET);
 487   DCHECK(!waiting_read_);
 488   DCHECK(read_callback_.is_null());
 489   DCHECK(!core_->read_iobuffer_);
 490
 491   return DoRead(buf, buf_len, callback);
 492 }
 493
 494 int TCPSocketWin::Write(IOBuffer* buf,
 495                         int buf_len,
 496                         const CompletionCallback& callback) {
 497   DCHECK(CalledOnValidThread());
 498   DCHECK_NE(socket_, INVALID_SOCKET);
 499   DCHECK(!waiting_write_);
 500   DCHECK(write_callback_.is_null());
 501   DCHECK_GT(buf_len, 0);
 502   DCHECK(!core_->write_iobuffer_);
 503
 504   base::StatsCounter writes("tcp.writes");
 505   writes.Increment();
 506
 507   WSABUF write_buffer;
 508   write_buffer.len = buf_len;
 509   write_buffer.buf = buf->data();
 510
 511   // TODO(wtc): Remove the assertion after enough testing.
 512   AssertEventNotSignaled(core_->write_overlapped_.hEvent);
 513   DWORD num;
 514   int rv = WSASend(socket_, &write_buffer, 1, &num, 0,
 515                    &core_->write_overlapped_, NULL);
 516   if (rv == 0) {
 517     if (ResetEventIfSignaled(core_->write_overlapped_.hEvent)) {
 518       rv = static_cast<int>(num);
 519       if (rv > buf_len || rv < 0) {
 520         // It seems that some winsock interceptors report that more was written
 521         // than was available. Treat this as an error.  http://crbug.com/27870
 522         LOG(ERROR) << "Detected broken LSP: Asked to write " << buf_len
 523                    << " bytes, but " << rv << " bytes reported.";
 524         return ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
 525       }
 526       base::StatsCounter write_bytes("tcp.write_bytes");
 527       write_bytes.Add(rv);
 528       net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_SENT, rv,
 529                                     buf->data());
 530       return rv;
 531     }
 532   } else {
 533     int os_error = WSAGetLastError();
 534     if (os_error != WSA_IO_PENDING) {
 535       int net_error = MapSystemError(os_error);
 536       net_log_.AddEvent(NetLog::TYPE_SOCKET_WRITE_ERROR,
 537                         CreateNetLogSocketErrorCallback(net_error, os_error));
 538       return net_error;
 539     }
 540   }
 541   waiting_write_ = true;
 542   write_callback_ = callback;
 543   core_->write_iobuffer_ = buf;
 544   core_->write_buffer_length_ = buf_len;
 545   core_->WatchForWrite();
 546   return ERR_IO_PENDING;
 547 }
 548
 549 int TCPSocketWin::GetLocalAddress(IPEndPoint* address) const {
 550   DCHECK(CalledOnValidThread());
 551   DCHECK(address);
 552
 553   SockaddrStorage storage;
 554   if (getsockname(socket_, storage.addr, &storage.addr_len))
 555     return MapSystemError(WSAGetLastError());
 556   if (!address->FromSockAddr(storage.addr, storage.addr_len))
 557     return ERR_ADDRESS_INVALID;
 558
 559   return OK;
 560 }
 561
 562 int TCPSocketWin::GetPeerAddress(IPEndPoint* address) const {
 563   DCHECK(CalledOnValidThread());
 564   DCHECK(address);
 565   if (!IsConnected())
 566     return ERR_SOCKET_NOT_CONNECTED;
 567   *address = *peer_address_;
 568   return OK;
 569 }
 570
 571 int TCPSocketWin::SetDefaultOptionsForServer() {
 572   return SetExclusiveAddrUse();
 573 }
 574
 575 void TCPSocketWin::SetDefaultOptionsForClient() {
 576   // Increase the socket buffer sizes from the default sizes for WinXP.  In
 577   // performance testing, there is substantial benefit by increasing from 8KB
 578   // to 64KB.
 579   // See also:
 580   //    http://support.microsoft.com/kb/823764/EN-US
 581   // On Vista, if we manually set these sizes, Vista turns off its receive
 582   // window auto-tuning feature.
 583   //    http://blogs.msdn.com/wndp/archive/2006/05/05/Winhec-blog-tcpip-2.aspx
 584   // Since Vista's auto-tune is better than any static value we can could set,
 585   // only change these on pre-vista machines.
 586   if (base::win::GetVersion() < base::win::VERSION_VISTA) {
 587     const int32 kSocketBufferSize = 64 * 1024;
 588     SetSocketReceiveBufferSize(socket_, kSocketBufferSize);
 589     SetSocketSendBufferSize(socket_, kSocketBufferSize);
 590   }
 591
 592   DisableNagle(socket_, true);
 593   SetTCPKeepAlive(socket_, true, kTCPKeepAliveSeconds);
 594 }
 595
 596 int TCPSocketWin::SetExclusiveAddrUse() {
 597   // On Windows, a bound end point can be hijacked by another process by
 598   // setting SO_REUSEADDR. Therefore a Windows-only option SO_EXCLUSIVEADDRUSE
 599   // was introduced in Windows NT 4.0 SP4. If the socket that is bound to the
 600   // end point has SO_EXCLUSIVEADDRUSE enabled, it is not possible for another
 601   // socket to forcibly bind to the end point until the end point is unbound.
 602   // It is recommend that all server applications must use SO_EXCLUSIVEADDRUSE.
 603   // MSDN: http://goo.gl/M6fjQ.
 604   //
 605   // Unlike on *nix, on Windows a TCP server socket can always bind to an end
 606   // point in TIME_WAIT state without setting SO_REUSEADDR, therefore it is not
 607   // needed here.
 608   //
 609   // SO_EXCLUSIVEADDRUSE will prevent a TCP client socket from binding to an end
 610   // point in TIME_WAIT status. It does not have this effect for a TCP server
 611   // socket.
 612
 613   BOOL true_value = 1;
 614   int rv = setsockopt(socket_, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
 615                       reinterpret_cast<const char*>(&true_value),
 616                       sizeof(true_value));
 617   if (rv < 0)
 618     return MapSystemError(errno);
 619   return OK;
 620 }
 621
 622 int TCPSocketWin::SetReceiveBufferSize(int32 size) {
 623   DCHECK(CalledOnValidThread());
 624   return SetSocketReceiveBufferSize(socket_, size);
 625 }
 626
 627 int TCPSocketWin::SetSendBufferSize(int32 size) {
 628   DCHECK(CalledOnValidThread());
 629   return SetSocketSendBufferSize(socket_, size);
 630 }
 631
 632 bool TCPSocketWin::SetKeepAlive(bool enable, int delay) {
 633   return SetTCPKeepAlive(socket_, enable, delay);
 634 }
 635
 636 bool TCPSocketWin::SetNoDelay(bool no_delay) {
 637   return DisableNagle(socket_, no_delay);
 638 }
 639
 640 void TCPSocketWin::Close() {
 641   DCHECK(CalledOnValidThread());
 642
 643   if (socket_ != INVALID_SOCKET) {
 644     // Note: don't use CancelIo to cancel pending IO because it doesn't work
 645     // when there is a Winsock layered service provider.
 646
 647     // In most socket implementations, closing a socket results in a graceful
 648     // connection shutdown, but in Winsock we have to call shutdown explicitly.
 649     // See the MSDN page "Graceful Shutdown, Linger Options, and Socket Closure"
 650     // at http://msdn.microsoft.com/en-us/library/ms738547.aspx
 651     shutdown(socket_, SD_SEND);
 652
 653     // This cancels any pending IO.
 654     if (closesocket(socket_) < 0)
 655       PLOG(ERROR) << "closesocket";
 656     socket_ = INVALID_SOCKET;
 657   }
 658
 659   if (!accept_callback_.is_null()) {
 660     accept_watcher_.StopWatching();
 661     accept_socket_ = NULL;
 662     accept_address_ = NULL;
 663     accept_callback_.Reset();
 664   }
 665
 666   if (accept_event_) {
 667     WSACloseEvent(accept_event_);
 668     accept_event_ = WSA_INVALID_EVENT;
 669   }
 670
 671   if (core_) {
 672     if (waiting_connect_) {
 673       // We closed the socket, so this notification will never come.
 674       // From MSDN' WSAEventSelect documentation:
 675       // "Closing a socket with closesocket also cancels the association and
 676       // selection of network events specified in WSAEventSelect for the
 677       // socket".
 678       core_->Release();
 679     }
 680     core_->Detach();
 681     core_ = NULL;
 682   }
 683
 684   waiting_connect_ = false;
 685   waiting_read_ = false;
 686   waiting_write_ = false;
 687
 688   read_callback_.Reset();
 689   write_callback_.Reset();
 690   peer_address_.reset();
 691   connect_os_error_ = 0;
 692 }
 693
 694 bool TCPSocketWin::UsingTCPFastOpen() const {
 695   // Not supported on windows.
 696   return false;
 697 }
 698
 699 void TCPSocketWin::StartLoggingMultipleConnectAttempts(
 700     const AddressList& addresses) {
 701   if (!logging_multiple_connect_attempts_) {
 702     logging_multiple_connect_attempts_ = true;
 703     LogConnectBegin(addresses);
 704   } else {
 705     NOTREACHED();
 706   }
 707 }
 708
 709 void TCPSocketWin::EndLoggingMultipleConnectAttempts(int net_error) {
 710   if (logging_multiple_connect_attempts_) {
 711     LogConnectEnd(net_error);
 712     logging_multiple_connect_attempts_ = false;
 713   } else {
 714     NOTREACHED();
 715   }
 716 }
 717
 718 int TCPSocketWin::AcceptInternal(scoped_ptr<TCPSocketWin>* socket,
 719                                  IPEndPoint* address) {
 720   SockaddrStorage storage;
 721   int new_socket = accept(socket_, storage.addr, &storage.addr_len);
 722   if (new_socket < 0) {
 723     int net_error = MapSystemError(WSAGetLastError());
 724     if (net_error != ERR_IO_PENDING)
 725       net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, net_error);
 726     return net_error;
 727   }
 728
 729   IPEndPoint ip_end_point;
 730   if (!ip_end_point.FromSockAddr(storage.addr, storage.addr_len)) {
 731     NOTREACHED();
 732     if (closesocket(new_socket) < 0)
 733       PLOG(ERROR) << "closesocket";
 734     int net_error = ERR_ADDRESS_INVALID;
 735     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, net_error);
 736     return net_error;
 737   }
 738   scoped_ptr<TCPSocketWin> tcp_socket(new TCPSocketWin(
 739       net_log_.net_log(), net_log_.source()));
 740   int adopt_result = tcp_socket->AdoptConnectedSocket(new_socket, ip_end_point);
 741   if (adopt_result != OK) {
 742     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, adopt_result);
 743     return adopt_result;
 744   }
 745   *socket = tcp_socket.Pass();
 746   *address = ip_end_point;
 747   net_log_.EndEvent(NetLog::TYPE_TCP_ACCEPT,
 748                     CreateNetLogIPEndPointCallback(&ip_end_point));
 749   return OK;
 750 }
 751
 752 void TCPSocketWin::OnObjectSignaled(HANDLE object) {
 753   WSANETWORKEVENTS ev;
 754   if (WSAEnumNetworkEvents(socket_, accept_event_, &ev) == SOCKET_ERROR) {
 755     PLOG(ERROR) << "WSAEnumNetworkEvents()";
 756     return;
 757   }
 758
 759   if (ev.lNetworkEvents & FD_ACCEPT) {
 760     int result = AcceptInternal(accept_socket_, accept_address_);
 761     if (result != ERR_IO_PENDING) {
 762       accept_socket_ = NULL;
 763       accept_address_ = NULL;
 764       base::ResetAndReturn(&accept_callback_).Run(result);
 765     }
 766   } else {
 767     // This happens when a client opens a connection and closes it before we
 768     // have a chance to accept it.
 769     DCHECK(ev.lNetworkEvents == 0);
 770
 771     // Start watching the next FD_ACCEPT event.
 772     WSAEventSelect(socket_, accept_event_, FD_ACCEPT);
 773     accept_watcher_.StartWatching(accept_event_, this);
 774   }
 775 }
 776
 777 int TCPSocketWin::DoConnect() {
 778   DCHECK_EQ(connect_os_error_, 0);
 779   DCHECK(!core_);
 780
 781   net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT,
 782                       CreateNetLogIPEndPointCallback(peer_address_.get()));
 783
 784   core_ = new Core(this);
 785   // WSAEventSelect sets the socket to non-blocking mode as a side effect.
 786   // Our connect() and recv() calls require that the socket be non-blocking.
 787   WSAEventSelect(socket_, core_->read_overlapped_.hEvent, FD_CONNECT);
 788
 789   SockaddrStorage storage;
 790   if (!peer_address_->ToSockAddr(storage.addr, &storage.addr_len))
 791     return ERR_ADDRESS_INVALID;
 792   if (!connect(socket_, storage.addr, storage.addr_len)) {
 793     // Connected without waiting!
 794     //
 795     // The MSDN page for connect says:
 796     //   With a nonblocking socket, the connection attempt cannot be completed
 797     //   immediately. In this case, connect will return SOCKET_ERROR, and
 798     //   WSAGetLastError will return WSAEWOULDBLOCK.
 799     // which implies that for a nonblocking socket, connect never returns 0.
 800     // It's not documented whether the event object will be signaled or not
 801     // if connect does return 0.  So the code below is essentially dead code
 802     // and we don't know if it's correct.
 803     NOTREACHED();
 804
 805     if (ResetEventIfSignaled(core_->read_overlapped_.hEvent))
 806       return OK;
 807   } else {
 808     int os_error = WSAGetLastError();
 809     if (os_error != WSAEWOULDBLOCK) {
 810       LOG(ERROR) << "connect failed: " << os_error;
 811       connect_os_error_ = os_error;
 812       int rv = MapConnectError(os_error);
 813       CHECK_NE(ERR_IO_PENDING, rv);
 814       return rv;
 815     }
 816   }
 817
 818   core_->WatchForRead();
 819   return ERR_IO_PENDING;
 820 }
 821
 822 void TCPSocketWin::DoConnectComplete(int result) {
 823   // Log the end of this attempt (and any OS error it threw).
 824   int os_error = connect_os_error_;
 825   connect_os_error_ = 0;
 826   if (result != OK) {
 827     net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT,
 828                       NetLog::IntegerCallback("os_error", os_error));
 829   } else {
 830     net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT);
 831   }
 832
 833   if (!logging_multiple_connect_attempts_)
 834     LogConnectEnd(result);
 835 }
 836
 837 void TCPSocketWin::LogConnectBegin(const AddressList& addresses) {
 838   base::StatsCounter connects("tcp.connect");
 839   connects.Increment();
 840
 841   net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT,
 842                       addresses.CreateNetLogCallback());
 843 }
 844
 845 void TCPSocketWin::LogConnectEnd(int net_error) {
 846   if (net_error == OK)
 847     UpdateConnectionTypeHistograms(CONNECTION_ANY);
 848
 849   if (net_error != OK) {
 850     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, net_error);
 851     return;
 852   }
 853
 854   struct sockaddr_storage source_address;
 855   socklen_t addrlen = sizeof(source_address);
 856   int rv = getsockname(
 857       socket_, reinterpret_cast<struct sockaddr*>(&source_address), &addrlen);
 858   if (rv != 0) {
 859     LOG(ERROR) << "getsockname() [rv: " << rv
 860                << "] error: " << WSAGetLastError();
 861     NOTREACHED();
 862     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, rv);
 863     return;
 864   }
 865
 866   net_log_.EndEvent(
 867       NetLog::TYPE_TCP_CONNECT,
 868       CreateNetLogSourceAddressCallback(
 869           reinterpret_cast<const struct sockaddr*>(&source_address),
 870           sizeof(source_address)));
 871 }
 872
 873 int TCPSocketWin::DoRead(IOBuffer* buf, int buf_len,
 874                          const CompletionCallback& callback) {
 875   if (!core_->non_blocking_reads_initialized_) {
 876     WSAEventSelect(socket_, core_->read_overlapped_.hEvent,
 877                    FD_READ | FD_CLOSE);
 878     core_->non_blocking_reads_initialized_ = true;
 879   }
 880   int rv = recv(socket_, buf->data(), buf_len, 0);
 881   if (rv == SOCKET_ERROR) {
 882     int os_error = WSAGetLastError();
 883     if (os_error != WSAEWOULDBLOCK) {
 884       int net_error = MapSystemError(os_error);
 885       net_log_.AddEvent(
 886           NetLog::TYPE_SOCKET_READ_ERROR,
 887           CreateNetLogSocketErrorCallback(net_error, os_error));
 888       return net_error;
 889     }
 890   } else {
 891     base::StatsCounter read_bytes("tcp.read_bytes");
 892     if (rv > 0)
 893       read_bytes.Add(rv);
 894     net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_RECEIVED, rv,
 895                                   buf->data());
 896     return rv;
 897   }
 898
 899   waiting_read_ = true;
 900   read_callback_ = callback;
 901   core_->read_iobuffer_ = buf;
 902   core_->read_buffer_length_ = buf_len;
 903   core_->WatchForRead();
 904   return ERR_IO_PENDING;
 905 }
 906
 907 void TCPSocketWin::DidCompleteConnect() {
 908   DCHECK(waiting_connect_);
 909   DCHECK(!read_callback_.is_null());
 910   int result;
 911
 912   WSANETWORKEVENTS events;
 913   int rv = WSAEnumNetworkEvents(socket_, core_->read_overlapped_.hEvent,
 914                                 &events);
 915   int os_error = 0;
 916   if (rv == SOCKET_ERROR) {
 917     NOTREACHED();
 918     os_error = WSAGetLastError();
 919     result = MapSystemError(os_error);
 920   } else if (events.lNetworkEvents & FD_CONNECT) {
 921     os_error = events.iErrorCode[FD_CONNECT_BIT];
 922     result = MapConnectError(os_error);
 923   } else {
 924     NOTREACHED();
 925     result = ERR_UNEXPECTED;
 926   }
 927
 928   connect_os_error_ = os_error;
 929   DoConnectComplete(result);
 930   waiting_connect_ = false;
 931
 932   DCHECK_NE(result, ERR_IO_PENDING);
 933   base::ResetAndReturn(&read_callback_).Run(result);
 934 }
 935
 936 void TCPSocketWin::DidCompleteWrite() {
 937   DCHECK(waiting_write_);
 938   DCHECK(!write_callback_.is_null());
 939
 940   DWORD num_bytes, flags;
 941   BOOL ok = WSAGetOverlappedResult(socket_, &core_->write_overlapped_,
 942                                    &num_bytes, FALSE, &flags);
 943   WSAResetEvent(core_->write_overlapped_.hEvent);
 944   waiting_write_ = false;
 945   int rv;
 946   if (!ok) {
 947     int os_error = WSAGetLastError();
 948     rv = MapSystemError(os_error);
 949     net_log_.AddEvent(NetLog::TYPE_SOCKET_WRITE_ERROR,
 950                       CreateNetLogSocketErrorCallback(rv, os_error));
 951   } else {
 952     rv = static_cast<int>(num_bytes);
 953     if (rv > core_->write_buffer_length_ || rv < 0) {
 954       // It seems that some winsock interceptors report that more was written
 955       // than was available. Treat this as an error.  http://crbug.com/27870
 956       LOG(ERROR) << "Detected broken LSP: Asked to write "
 957                  << core_->write_buffer_length_ << " bytes, but " << rv
 958                  << " bytes reported.";
 959       rv = ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
 960     } else {
 961       base::StatsCounter write_bytes("tcp.write_bytes");
 962       write_bytes.Add(num_bytes);
 963       net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_SENT, num_bytes,
 964                                     core_->write_iobuffer_->data());
 965     }
 966   }
 967
 968   core_->write_iobuffer_ = NULL;
 969
 970   DCHECK_NE(rv, ERR_IO_PENDING);
 971   base::ResetAndReturn(&write_callback_).Run(rv);
 972 }
 973
 974 void TCPSocketWin::DidSignalRead() {
 975   DCHECK(waiting_read_);
 976   DCHECK(!read_callback_.is_null());
 977
 978   int os_error = 0;
 979   WSANETWORKEVENTS network_events;
 980   int rv = WSAEnumNetworkEvents(socket_, core_->read_overlapped_.hEvent,
 981                                 &network_events);
 982   if (rv == SOCKET_ERROR) {
 983     os_error = WSAGetLastError();
 984     rv = MapSystemError(os_error);
 985   } else if (network_events.lNetworkEvents) {
 986     DCHECK_EQ(network_events.lNetworkEvents & ~(FD_READ | FD_CLOSE), 0);
 987     // If network_events.lNetworkEvents is FD_CLOSE and
 988     // network_events.iErrorCode[FD_CLOSE_BIT] is 0, it is a graceful
 989     // connection closure. It is tempting to directly set rv to 0 in
 990     // this case, but the MSDN pages for WSAEventSelect and
 991     // WSAAsyncSelect recommend we still call DoRead():
 992     //   FD_CLOSE should only be posted after all data is read from a
 993     //   socket, but an application should check for remaining data upon
 994     //   receipt of FD_CLOSE to avoid any possibility of losing data.
 995     //
 996     // If network_events.iErrorCode[FD_READ_BIT] or
 997     // network_events.iErrorCode[FD_CLOSE_BIT] is nonzero, still call
 998     // DoRead() because recv() reports a more accurate error code
 999     // (WSAECONNRESET vs. WSAECONNABORTED) when the connection was
1000     // reset.
1001     rv = DoRead(core_->read_iobuffer_, core_->read_buffer_length_,
1002                 read_callback_);
1003     if (rv == ERR_IO_PENDING)
1004       return;
1005   } else {
1006     // This may happen because Read() may succeed synchronously and
1007     // consume all the received data without resetting the event object.
1008     core_->WatchForRead();
1009     return;
1010   }
1011
1012   waiting_read_ = false;
1013   core_->read_iobuffer_ = NULL;
1014   core_->read_buffer_length_ = 0;
1015
1016   DCHECK_NE(rv, ERR_IO_PENDING);
1017   base::ResetAndReturn(&read_callback_).Run(rv);
1018 }
1019
1020 }  // namespace net
1021