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