base/sync_socket_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 "base/sync_socket.h"
   6
   7 #include <limits.h>
   8 #include <stddef.h>
   9
  10 #include "base/logging.h"
  11 #include "base/rand_util.h"
  12 #include "base/stl_util.h"
  13 #include "base/threading/scoped_blocking_call.h"
  14 #include "base/win/scoped_handle.h"
  15
  16 namespace base {
  17
  18 using win::ScopedHandle;
  19
  20 namespace {
  21 // IMPORTANT: do not change how this name is generated because it will break
  22 // in sandboxed scenarios as we might have by-name policies that allow pipe
  23 // creation. Also keep the secure random number generation.
  24 const wchar_t kPipeNameFormat[] = L"\\\\.\\pipe\\chrome.sync.%u.%u.%lu";
  25 const size_t kPipePathMax = base::size(kPipeNameFormat) + (3 * 10) + 1;
  26
  27 // To avoid users sending negative message lengths to Send/Receive
  28 // we clamp message lengths, which are size_t, to no more than INT_MAX.
  29 const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
  30
  31 const int kOutBufferSize = 4096;
  32 const int kInBufferSize = 4096;
  33 const int kDefaultTimeoutMilliSeconds = 1000;
  34
  35 bool CreatePairImpl(HANDLE* socket_a, HANDLE* socket_b, bool overlapped) {
  36   DCHECK_NE(socket_a, socket_b);
  37   DCHECK_EQ(*socket_a, SyncSocket::kInvalidHandle);
  38   DCHECK_EQ(*socket_b, SyncSocket::kInvalidHandle);
  39
  40   wchar_t name[kPipePathMax];
  41   ScopedHandle handle_a;
  42   DWORD flags = PIPE_ACCESS_DUPLEX | FILE_FLAG_FIRST_PIPE_INSTANCE;
  43   if (overlapped)
  44     flags |= FILE_FLAG_OVERLAPPED;
  45
  46   do {
  47     unsigned long rnd_name;
  48     RandBytes(&rnd_name, sizeof(rnd_name));
  49
  50     swprintf(name, kPipePathMax,
  51              kPipeNameFormat,
  52              GetCurrentProcessId(),
  53              GetCurrentThreadId(),
  54              rnd_name);
  55
  56     handle_a.Set(CreateNamedPipeW(
  57         name,
  58         flags,
  59         PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
  60         1,
  61         kOutBufferSize,
  62         kInBufferSize,
  63         kDefaultTimeoutMilliSeconds,
  64         NULL));
  65   } while (!handle_a.IsValid() &&
  66            (GetLastError() == ERROR_PIPE_BUSY));
  67
  68   if (!handle_a.IsValid()) {
  69     NOTREACHED();
  70     return false;
  71   }
  72
  73   // The SECURITY_ANONYMOUS flag means that the server side (handle_a) cannot
  74   // impersonate the client (handle_b). This allows us not to care which side
  75   // ends up in which side of a privilege boundary.
  76   flags = SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS;
  77   if (overlapped)
  78     flags |= FILE_FLAG_OVERLAPPED;
  79
  80   ScopedHandle handle_b(CreateFileW(name,
  81                                     GENERIC_READ | GENERIC_WRITE,
  82                                     0,          // no sharing.
  83                                     NULL,       // default security attributes.
  84                                     OPEN_EXISTING,  // opens existing pipe.
  85                                     flags,
  86                                     NULL));     // no template file.
  87   if (!handle_b.IsValid()) {
  88     DPLOG(ERROR) << "CreateFileW failed";
  89     return false;
  90   }
  91
  92   if (!ConnectNamedPipe(handle_a.Get(), NULL)) {
  93     DWORD error = GetLastError();
  94     if (error != ERROR_PIPE_CONNECTED) {
  95       DPLOG(ERROR) << "ConnectNamedPipe failed";
  96       return false;
  97     }
  98   }
  99
 100   *socket_a = handle_a.Take();
 101   *socket_b = handle_b.Take();
 102
 103   return true;
 104 }
 105
 106 // Inline helper to avoid having the cast everywhere.
 107 DWORD GetNextChunkSize(size_t current_pos, size_t max_size) {
 108   // The following statement is for 64 bit portability.
 109   return static_cast<DWORD>(((max_size - current_pos) <= UINT_MAX) ?
 110       (max_size - current_pos) : UINT_MAX);
 111 }
 112
 113 // Template function that supports calling ReadFile or WriteFile in an
 114 // overlapped fashion and waits for IO completion.  The function also waits
 115 // on an event that can be used to cancel the operation.  If the operation
 116 // is cancelled, the function returns and closes the relevant socket object.
 117 template <typename BufferType, typename Function>
 118 size_t CancelableFileOperation(Function operation,
 119                                HANDLE file,
 120                                BufferType* buffer,
 121                                size_t length,
 122                                WaitableEvent* io_event,
 123                                WaitableEvent* cancel_event,
 124                                CancelableSyncSocket* socket,
 125                                DWORD timeout_in_ms) {
 126   ScopedBlockingCall scoped_blocking_call(BlockingType::MAY_BLOCK);
 127   // The buffer must be byte size or the length check won't make much sense.
 128   static_assert(sizeof(buffer[0]) == sizeof(char), "incorrect buffer type");
 129   DCHECK_GT(length, 0u);
 130   DCHECK_LE(length, kMaxMessageLength);
 131   DCHECK_NE(file, SyncSocket::kInvalidHandle);
 132
 133   // Track the finish time so we can calculate the timeout as data is read.
 134   TimeTicks current_time, finish_time;
 135   if (timeout_in_ms != INFINITE) {
 136     current_time = TimeTicks::Now();
 137     finish_time =
 138         current_time + base::TimeDelta::FromMilliseconds(timeout_in_ms);
 139   }
 140
 141   size_t count = 0;
 142   do {
 143     // The OVERLAPPED structure will be modified by ReadFile or WriteFile.
 144     OVERLAPPED ol = { 0 };
 145     ol.hEvent = io_event->handle();
 146
 147     const DWORD chunk = GetNextChunkSize(count, length);
 148     // This is either the ReadFile or WriteFile call depending on whether
 149     // we're receiving or sending data.
 150     DWORD len = 0;
 151     const BOOL operation_ok = operation(
 152         file, static_cast<BufferType*>(buffer) + count, chunk, &len, &ol);
 153     if (!operation_ok) {
 154       if (::GetLastError() == ERROR_IO_PENDING) {
 155         HANDLE events[] = { io_event->handle(), cancel_event->handle() };
 156         const int wait_result = WaitForMultipleObjects(
 157             base::size(events), events, FALSE,
 158             timeout_in_ms == INFINITE
 159                 ? timeout_in_ms
 160                 : static_cast<DWORD>(
 161                       (finish_time - current_time).InMilliseconds()));
 162         if (wait_result != WAIT_OBJECT_0 + 0) {
 163           // CancelIo() doesn't synchronously cancel outstanding IO, only marks
 164           // outstanding IO for cancellation. We must call GetOverlappedResult()
 165           // below to ensure in flight writes complete before returning.
 166           CancelIo(file);
 167         }
 168
 169         // We set the |bWait| parameter to TRUE for GetOverlappedResult() to
 170         // ensure writes are complete before returning.
 171         if (!GetOverlappedResult(file, &ol, &len, TRUE))
 172           len = 0;
 173
 174         if (wait_result == WAIT_OBJECT_0 + 1) {
 175           DVLOG(1) << "Shutdown was signaled. Closing socket.";
 176           socket->Close();
 177           return count;
 178         }
 179
 180         // Timeouts will be handled by the while() condition below since
 181         // GetOverlappedResult() may complete successfully after CancelIo().
 182         DCHECK(wait_result == WAIT_OBJECT_0 + 0 || wait_result == WAIT_TIMEOUT);
 183       } else {
 184         break;
 185       }
 186     }
 187
 188     count += len;
 189
 190     // Quit the operation if we can't write/read anymore.
 191     if (len != chunk)
 192       break;
 193
 194     // Since TimeTicks::Now() is expensive, only bother updating the time if we
 195     // have more work to do.
 196     if (timeout_in_ms != INFINITE && count < length)
 197       current_time = base::TimeTicks::Now();
 198   } while (count < length &&
 199            (timeout_in_ms == INFINITE || current_time < finish_time));
 200
 201   return count;
 202 }
 203
 204 }  // namespace
 205
 206 #if defined(COMPONENT_BUILD)
 207 const SyncSocket::Handle SyncSocket::kInvalidHandle = INVALID_HANDLE_VALUE;
 208 #endif
 209
 210 SyncSocket::SyncSocket() : handle_(kInvalidHandle) {}
 211
 212 SyncSocket::~SyncSocket() {
 213   Close();
 214 }
 215
 216 // static
 217 bool SyncSocket::CreatePair(SyncSocket* socket_a, SyncSocket* socket_b) {
 218   return CreatePairImpl(&socket_a->handle_, &socket_b->handle_, false);
 219 }
 220
 221 // static
 222 SyncSocket::Handle SyncSocket::UnwrapHandle(
 223     const TransitDescriptor& descriptor) {
 224   return descriptor;
 225 }
 226
 227 bool SyncSocket::PrepareTransitDescriptor(ProcessHandle peer_process_handle,
 228                                           TransitDescriptor* descriptor) {
 229   DCHECK(descriptor);
 230   if (!::DuplicateHandle(GetCurrentProcess(), handle(), peer_process_handle,
 231                          descriptor, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 232     DPLOG(ERROR) << "Cannot duplicate socket handle for peer process.";
 233     return false;
 234   }
 235   return true;
 236 }
 237
 238 bool SyncSocket::Close() {
 239   if (handle_ == kInvalidHandle)
 240     return true;
 241
 242   const BOOL result = CloseHandle(handle_);
 243   handle_ = kInvalidHandle;
 244   return result == TRUE;
 245 }
 246
 247 size_t SyncSocket::Send(const void* buffer, size_t length) {
 248   ScopedBlockingCall scoped_blocking_call(BlockingType::MAY_BLOCK);
 249   DCHECK_GT(length, 0u);
 250   DCHECK_LE(length, kMaxMessageLength);
 251   DCHECK_NE(handle_, kInvalidHandle);
 252   size_t count = 0;
 253   while (count < length) {
 254     DWORD len;
 255     DWORD chunk = GetNextChunkSize(count, length);
 256     if (::WriteFile(handle_, static_cast<const char*>(buffer) + count, chunk,
 257                     &len, NULL) == FALSE) {
 258       return count;
 259     }
 260     count += len;
 261   }
 262   return count;
 263 }
 264
 265 size_t SyncSocket::ReceiveWithTimeout(void* buffer,
 266                                       size_t length,
 267                                       TimeDelta timeout) {
 268   NOTIMPLEMENTED();
 269   return 0;
 270 }
 271
 272 size_t SyncSocket::Receive(void* buffer, size_t length) {
 273   ScopedBlockingCall scoped_blocking_call(BlockingType::MAY_BLOCK);
 274   DCHECK_GT(length, 0u);
 275   DCHECK_LE(length, kMaxMessageLength);
 276   DCHECK_NE(handle_, kInvalidHandle);
 277   size_t count = 0;
 278   while (count < length) {
 279     DWORD len;
 280     DWORD chunk = GetNextChunkSize(count, length);
 281     if (::ReadFile(handle_, static_cast<char*>(buffer) + count, chunk, &len,
 282                    NULL) == FALSE) {
 283       return count;
 284     }
 285     count += len;
 286   }
 287   return count;
 288 }
 289
 290 size_t SyncSocket::Peek() {
 291   DWORD available = 0;
 292   PeekNamedPipe(handle_, NULL, 0, NULL, &available, NULL);
 293   return available;
 294 }
 295
 296 SyncSocket::Handle SyncSocket::Release() {
 297   Handle r = handle_;
 298   handle_ = kInvalidHandle;
 299   return r;
 300 }
 301
 302 CancelableSyncSocket::CancelableSyncSocket()
 303     : shutdown_event_(base::WaitableEvent::ResetPolicy::MANUAL,
 304                       base::WaitableEvent::InitialState::NOT_SIGNALED),
 305       file_operation_(base::WaitableEvent::ResetPolicy::MANUAL,
 306                       base::WaitableEvent::InitialState::NOT_SIGNALED) {}
 307
 308 CancelableSyncSocket::CancelableSyncSocket(Handle handle)
 309     : SyncSocket(handle),
 310       shutdown_event_(base::WaitableEvent::ResetPolicy::MANUAL,
 311                       base::WaitableEvent::InitialState::NOT_SIGNALED),
 312       file_operation_(base::WaitableEvent::ResetPolicy::MANUAL,
 313                       base::WaitableEvent::InitialState::NOT_SIGNALED) {}
 314
 315 bool CancelableSyncSocket::Shutdown() {
 316   // This doesn't shut down the pipe immediately, but subsequent Receive or Send
 317   // methods will fail straight away.
 318   shutdown_event_.Signal();
 319   return true;
 320 }
 321
 322 bool CancelableSyncSocket::Close() {
 323   const bool result = SyncSocket::Close();
 324   shutdown_event_.Reset();
 325   return result;
 326 }
 327
 328 size_t CancelableSyncSocket::Send(const void* buffer, size_t length) {
 329   static const DWORD kWaitTimeOutInMs = 500;
 330   return CancelableFileOperation(
 331       &::WriteFile, handle_, reinterpret_cast<const char*>(buffer), length,
 332       &file_operation_, &shutdown_event_, this, kWaitTimeOutInMs);
 333 }
 334
 335 size_t CancelableSyncSocket::Receive(void* buffer, size_t length) {
 336   return CancelableFileOperation(
 337       &::ReadFile, handle_, reinterpret_cast<char*>(buffer), length,
 338       &file_operation_, &shutdown_event_, this, INFINITE);
 339 }
 340
 341 size_t CancelableSyncSocket::ReceiveWithTimeout(void* buffer,
 342                                                 size_t length,
 343                                                 TimeDelta timeout) {
 344   return CancelableFileOperation(&::ReadFile, handle_,
 345                                  reinterpret_cast<char*>(buffer), length,
 346                                  &file_operation_, &shutdown_event_, this,
 347                                  static_cast<DWORD>(timeout.InMilliseconds()));
 348 }
 349
 350 // static
 351 bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a,
 352                                       CancelableSyncSocket* socket_b) {
 353   return CreatePairImpl(&socket_a->handle_, &socket_b->handle_, true);
 354 }
 355
 356 }  // namespace base