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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.Get(), 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(events), events, FALSE, | |
154 timeout_in_ms == INFINITE ? | |
155 timeout_in_ms : | |
156 static_cast<DWORD>( | |
157 (finish_time - current_time).InMilliseconds())); | |
158 if (wait_result != WAIT_OBJECT_0 + 0) { | |
159 // CancelIo() doesn't synchronously cancel outstanding IO, only marks | |
160 // outstanding IO for cancellation. We must call GetOverlappedResult() | |
161 // below to ensure in flight writes complete before returning. | |
162 CancelIo(file); | |
163 } | |
164 | |
165 // We set the |bWait| parameter to TRUE for GetOverlappedResult() to | |
166 // ensure writes are complete before returning. | |
167 if (!GetOverlappedResult(file, &ol, &len, TRUE)) | |
168 len = 0; | |
169 | |
170 if (wait_result == WAIT_OBJECT_0 + 1) { | |
171 DVLOG(1) << "Shutdown was signaled. Closing socket."; | |
172 socket->Close(); | |
173 return count; | |
174 } | |
175 | |
176 // Timeouts will be handled by the while() condition below since | |
177 // GetOverlappedResult() may complete successfully after CancelIo(). | |
178 DCHECK(wait_result == WAIT_OBJECT_0 + 0 || wait_result == WAIT_TIMEOUT); | |
179 } else { | |
180 break; | |
181 } | |
182 } | |
183 | |
184 count += len; | |
185 | |
186 // Quit the operation if we can't write/read anymore. | |
187 if (len != chunk) | |
188 break; | |
189 | |
190 // Since TimeTicks::Now() is expensive, only bother updating the time if we | |
191 // have more work to do. | |
192 if (timeout_in_ms != INFINITE && count < length) | |
193 current_time = base::TimeTicks::Now(); | |
194 } while (count < length && | |
195 (timeout_in_ms == INFINITE || current_time < finish_time)); | |
196 | |
197 return count; | |
198 } | |
199 | |
200 } // namespace | |
201 | |
202 #if defined(COMPONENT_BUILD) | |
203 const SyncSocket::Handle SyncSocket::kInvalidHandle = INVALID_HANDLE_VALUE; | |
204 #endif | |
205 | |
206 SyncSocket::SyncSocket() : handle_(kInvalidHandle) {} | |
207 | |
208 SyncSocket::~SyncSocket() { | |
209 Close(); | |
210 } | |
211 | |
212 // static | |
213 bool SyncSocket::CreatePair(SyncSocket* socket_a, SyncSocket* socket_b) { | |
214 return CreatePairImpl(&socket_a->handle_, &socket_b->handle_, false); | |
215 } | |
216 | |
217 // static | |
218 SyncSocket::Handle SyncSocket::UnwrapHandle( | |
219 const TransitDescriptor& descriptor) { | |
220 return descriptor; | |
221 } | |
222 | |
223 bool SyncSocket::PrepareTransitDescriptor(ProcessHandle peer_process_handle, | |
224 TransitDescriptor* descriptor) { | |
225 DCHECK(descriptor); | |
226 if (!::DuplicateHandle(GetCurrentProcess(), handle(), peer_process_handle, | |
227 descriptor, 0, FALSE, DUPLICATE_SAME_ACCESS)) { | |
228 DPLOG(ERROR) << "Cannot duplicate socket handle for peer process."; | |
229 return false; | |
230 } | |
231 return true; | |
232 } | |
233 | |
234 bool SyncSocket::Close() { | |
235 if (handle_ == kInvalidHandle) | |
236 return true; | |
237 | |
238 const BOOL result = CloseHandle(handle_); | |
239 handle_ = kInvalidHandle; | |
240 return result == TRUE; | |
241 } | |
242 | |
243 size_t SyncSocket::Send(const void* buffer, size_t length) { | |
244 ThreadRestrictions::AssertIOAllowed(); | |
245 DCHECK_GT(length, 0u); | |
246 DCHECK_LE(length, kMaxMessageLength); | |
247 DCHECK_NE(handle_, kInvalidHandle); | |
248 size_t count = 0; | |
249 while (count < length) { | |
250 DWORD len; | |
251 DWORD chunk = GetNextChunkSize(count, length); | |
252 if (WriteFile(handle_, static_cast<const char*>(buffer) + count, | |
253 chunk, &len, NULL) == FALSE) { | |
254 return count; | |
255 } | |
256 count += len; | |
257 } | |
258 return count; | |
259 } | |
260 | |
261 size_t SyncSocket::ReceiveWithTimeout(void* buffer, | |
262 size_t length, | |
263 TimeDelta timeout) { | |
264 NOTIMPLEMENTED(); | |
265 return 0; | |
266 } | |
267 | |
268 size_t SyncSocket::Receive(void* buffer, size_t length) { | |
269 ThreadRestrictions::AssertIOAllowed(); | |
270 DCHECK_GT(length, 0u); | |
271 DCHECK_LE(length, kMaxMessageLength); | |
272 DCHECK_NE(handle_, kInvalidHandle); | |
273 size_t count = 0; | |
274 while (count < length) { | |
275 DWORD len; | |
276 DWORD chunk = GetNextChunkSize(count, length); | |
277 if (ReadFile(handle_, static_cast<char*>(buffer) + count, | |
278 chunk, &len, NULL) == FALSE) { | |
279 return count; | |
280 } | |
281 count += len; | |
282 } | |
283 return count; | |
284 } | |
285 | |
286 size_t SyncSocket::Peek() { | |
287 DWORD available = 0; | |
288 PeekNamedPipe(handle_, NULL, 0, NULL, &available, NULL); | |
289 return available; | |
290 } | |
291 | |
292 CancelableSyncSocket::CancelableSyncSocket() | |
293 : shutdown_event_(true, false), file_operation_(true, false) { | |
294 } | |
295 | |
296 CancelableSyncSocket::CancelableSyncSocket(Handle handle) | |
297 : SyncSocket(handle), shutdown_event_(true, false), | |
298 file_operation_(true, false) { | |
299 } | |
300 | |
301 bool CancelableSyncSocket::Shutdown() { | |
302 // This doesn't shut down the pipe immediately, but subsequent Receive or Send | |
303 // methods will fail straight away. | |
304 shutdown_event_.Signal(); | |
305 return true; | |
306 } | |
307 | |
308 bool CancelableSyncSocket::Close() { | |
309 const bool result = SyncSocket::Close(); | |
310 shutdown_event_.Reset(); | |
311 return result; | |
312 } | |
313 | |
314 size_t CancelableSyncSocket::Send(const void* buffer, size_t length) { | |
315 static const DWORD kWaitTimeOutInMs = 500; | |
316 return CancelableFileOperation( | |
317 &WriteFile, handle_, reinterpret_cast<const char*>(buffer), | |
318 length, &file_operation_, &shutdown_event_, this, kWaitTimeOutInMs); | |
319 } | |
320 | |
321 size_t CancelableSyncSocket::Receive(void* buffer, size_t length) { | |
322 return CancelableFileOperation( | |
323 &ReadFile, handle_, reinterpret_cast<char*>(buffer), length, | |
324 &file_operation_, &shutdown_event_, this, INFINITE); | |
325 } | |
326 | |
327 size_t CancelableSyncSocket::ReceiveWithTimeout(void* buffer, | |
328 size_t length, | |
329 TimeDelta timeout) { | |
330 return CancelableFileOperation( | |
331 &ReadFile, handle_, reinterpret_cast<char*>(buffer), length, | |
332 &file_operation_, &shutdown_event_, this, | |
333 static_cast<DWORD>(timeout.InMilliseconds())); | |
334 } | |
335 | |
336 // static | |
337 bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a, | |
338 CancelableSyncSocket* socket_b) { | |
339 return CreatePairImpl(&socket_a->handle_, &socket_b->handle_, true); | |
340 } | |
341 | |
342 } // namespace base | |
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