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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/callback.h" | |
6 #include "base/logging.h" | |
7 #include "base/memory/scoped_ptr.h" | |
8 #include "sandbox/src/sharedmem_ipc_server.h" | |
9 #include "sandbox/src/sharedmem_ipc_client.h" | |
10 #include "sandbox/src/sandbox.h" | |
11 #include "sandbox/src/sandbox_types.h" | |
12 #include "sandbox/src/crosscall_params.h" | |
13 #include "sandbox/src/crosscall_server.h" | |
14 | |
15 namespace sandbox { | |
16 | |
17 SharedMemIPCServer::SharedMemIPCServer(HANDLE target_process, | |
18 DWORD target_process_id, | |
19 HANDLE target_job, | |
20 ThreadProvider* thread_provider, | |
21 Dispatcher* dispatcher) | |
22 : client_control_(NULL), | |
23 thread_provider_(thread_provider), | |
24 target_process_(target_process), | |
25 target_process_id_(target_process_id), | |
26 target_job_object_(target_job), | |
27 call_dispatcher_(dispatcher) { | |
28 } | |
29 | |
30 SharedMemIPCServer::~SharedMemIPCServer() { | |
31 // Free the wait handles associated with the thread pool. | |
32 if (!thread_provider_->UnRegisterWaits(this)) { | |
33 // Better to leak than to crash. | |
34 return; | |
35 } | |
36 // Free the IPC signal events. | |
37 ServerContexts::iterator it; | |
38 for (it = server_contexts_.begin(); it != server_contexts_.end(); ++it) { | |
39 ServerControl* context = (*it); | |
40 ::CloseHandle(context->ping_event); | |
41 ::CloseHandle(context->pong_event); | |
42 delete context; | |
43 } | |
44 } | |
45 | |
46 bool SharedMemIPCServer::Init(void* shared_mem, uint32 shared_size, | |
47 uint32 channel_size) { | |
48 // The shared memory needs to be at least as big as a channel. | |
49 if (shared_size < channel_size) { | |
50 return false; | |
51 } | |
52 // The channel size should be aligned. | |
53 if (0 != (channel_size % 32)) { | |
54 return false; | |
55 } | |
56 | |
57 // Calculate how many channels we can fit in the shared memory. | |
58 shared_size -= offsetof(IPCControl, channels); | |
59 size_t channel_count = shared_size / (sizeof(ChannelControl) + channel_size); | |
60 | |
61 // If we cannot fit even one channel we bail out. | |
62 if (0 == channel_count) { | |
63 return false; | |
64 } | |
65 // Calculate the start of the first channel. | |
66 size_t base_start = (sizeof(ChannelControl)* channel_count) + | |
67 offsetof(IPCControl, channels); | |
68 | |
69 client_control_ = reinterpret_cast<IPCControl*>(shared_mem); | |
70 client_control_->channels_count = 0; | |
71 | |
72 // This is the initialization that we do per-channel. Basically: | |
73 // 1) make two events (ping & pong) | |
74 // 2) create handles to the events for the client and the server. | |
75 // 3) initialize the channel (client_context) with the state. | |
76 // 4) initialize the server side of the channel (service_context). | |
77 // 5) call the thread provider RegisterWait to register the ping events. | |
78 for (size_t ix = 0; ix != channel_count; ++ix) { | |
79 ChannelControl* client_context = &client_control_->channels[ix]; | |
80 ServerControl* service_context = new ServerControl; | |
81 server_contexts_.push_back(service_context); | |
82 | |
83 if (!MakeEvents(&service_context->ping_event, | |
84 &service_context->pong_event, | |
85 &client_context->ping_event, | |
86 &client_context->pong_event)) { | |
87 return false; | |
88 } | |
89 | |
90 client_context->channel_base = base_start; | |
91 client_context->state = kFreeChannel; | |
92 | |
93 // Note that some of these values are available as members of this | |
94 // object but we put them again into the service_context because we | |
95 // will be called on a static method (ThreadPingEventReady) | |
96 service_context->shared_base = reinterpret_cast<char*>(shared_mem); | |
97 service_context->channel_size = channel_size; | |
98 service_context->channel = client_context; | |
99 service_context->channel_buffer = service_context->shared_base + | |
100 client_context->channel_base; | |
101 service_context->dispatcher = call_dispatcher_; | |
102 service_context->target_info.process = target_process_; | |
103 service_context->target_info.process_id = target_process_id_; | |
104 service_context->target_info.job_object = target_job_object_; | |
105 // Advance to the next channel. | |
106 base_start += channel_size; | |
107 // Register the ping event with the threadpool. | |
108 thread_provider_->RegisterWait(this, service_context->ping_event, | |
109 ThreadPingEventReady, service_context); | |
110 } | |
111 | |
112 // We create a mutex that the server locks. If the server dies unexpectedly, | |
113 // the thread that owns it will fail to release the lock and windows will | |
114 // report to the target (when it tries to acquire it) that the wait was | |
115 // abandoned. Note: We purposely leak the local handle because we want it to | |
116 // be closed by Windows itself so it is properly marked as abandoned if the | |
117 // server dies. | |
118 if (!::DuplicateHandle(::GetCurrentProcess(), | |
119 ::CreateMutexW(NULL, TRUE, NULL), | |
120 target_process_, &client_control_->server_alive, | |
121 SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, 0)) { | |
122 return false; | |
123 } | |
124 // This last setting indicates to the client all is setup. | |
125 client_control_->channels_count = channel_count; | |
126 return true; | |
127 } | |
128 | |
129 // Releases memory allocated for IPC arguments, if needed. | |
130 void ReleaseArgs(const IPCParams* ipc_params, void* args[kMaxIpcParams]) { | |
131 for (size_t i = 0; i < kMaxIpcParams; i++) { | |
132 switch (ipc_params->args[i]) { | |
133 case WCHAR_TYPE: { | |
134 delete reinterpret_cast<std::wstring*>(args[i]); | |
135 args[i] = NULL; | |
136 break; | |
137 } | |
138 case INOUTPTR_TYPE: { | |
139 delete reinterpret_cast<CountedBuffer*>(args[i]); | |
140 args[i] = NULL; | |
141 break; | |
142 } | |
143 default: break; | |
144 } | |
145 } | |
146 } | |
147 | |
148 // Fills up the list of arguments (args and ipc_params) for an IPC call. | |
149 bool GetArgs(CrossCallParamsEx* params, IPCParams* ipc_params, | |
150 void* args[kMaxIpcParams]) { | |
151 if (kMaxIpcParams < params->GetParamsCount()) | |
152 return false; | |
153 | |
154 for (uint32 i = 0; i < params->GetParamsCount(); i++) { | |
155 uint32 size; | |
156 ArgType type; | |
157 args[i] = params->GetRawParameter(i, &size, &type); | |
158 if (args[i]) { | |
159 ipc_params->args[i] = type; | |
160 switch (type) { | |
161 case WCHAR_TYPE: { | |
162 scoped_ptr<std::wstring> data(new std::wstring); | |
163 if (!params->GetParameterStr(i, data.get())) { | |
164 args[i] = 0; | |
165 ReleaseArgs(ipc_params, args); | |
166 return false; | |
167 } | |
168 args[i] = data.release(); | |
169 break; | |
170 } | |
171 case ULONG_TYPE: { | |
172 uint32 data; | |
173 if (!params->GetParameter32(i, &data)) { | |
174 ReleaseArgs(ipc_params, args); | |
175 return false; | |
176 } | |
177 IPCInt ipc_int(data); | |
178 args[i] = ipc_int.AsVoidPtr(); | |
179 break; | |
180 } | |
181 case VOIDPTR_TYPE : { | |
182 void* data; | |
183 if (!params->GetParameterVoidPtr(i, &data)) { | |
184 ReleaseArgs(ipc_params, args); | |
185 return false; | |
186 } | |
187 args[i] = data; | |
188 break; | |
189 } | |
190 case INOUTPTR_TYPE: { | |
191 if (!args[i]) { | |
192 ReleaseArgs(ipc_params, args); | |
193 return false; | |
194 } | |
195 CountedBuffer* buffer = new CountedBuffer(args[i] , size); | |
196 args[i] = buffer; | |
197 break; | |
198 } | |
199 default: break; | |
200 } | |
201 } | |
202 } | |
203 return true; | |
204 } | |
205 | |
206 bool SharedMemIPCServer::InvokeCallback(const ServerControl* service_context, | |
207 void* ipc_buffer, | |
208 CrossCallReturn* call_result) { | |
209 // Set the default error code; | |
210 SetCallError(SBOX_ERROR_INVALID_IPC, call_result); | |
211 uint32 output_size = 0; | |
212 // Parse, verify and copy the message. The handler operates on a copy | |
213 // of the message so the client cannot play dirty tricks by changing the | |
214 // data in the channel while the IPC is being processed. | |
215 scoped_ptr<CrossCallParamsEx> params( | |
216 CrossCallParamsEx::CreateFromBuffer(ipc_buffer, | |
217 service_context->channel_size, | |
218 &output_size)); | |
219 if (!params.get()) | |
220 return false; | |
221 | |
222 uint32 tag = params->GetTag(); | |
223 COMPILE_ASSERT(0 == INVALID_TYPE, Incorrect_type_enum); | |
224 IPCParams ipc_params = {0}; | |
225 ipc_params.ipc_tag = tag; | |
226 | |
227 void* args[kMaxIpcParams]; | |
228 if (!GetArgs(params.get(), &ipc_params, args)) | |
229 return false; | |
230 | |
231 IPCInfo ipc_info = {0}; | |
232 ipc_info.ipc_tag = tag; | |
233 ipc_info.client_info = &service_context->target_info; | |
234 Dispatcher* dispatcher = service_context->dispatcher; | |
235 DCHECK(dispatcher); | |
236 bool error = true; | |
237 Dispatcher* handler = NULL; | |
238 | |
239 Dispatcher::CallbackGeneric callback_generic; | |
240 handler = dispatcher->OnMessageReady(&ipc_params, &callback_generic); | |
241 if (handler) { | |
242 switch (params->GetParamsCount()) { | |
243 case 0: { | |
244 // Ask the IPC dispatcher if she can service this IPC. | |
245 Dispatcher::Callback0 callback = | |
246 reinterpret_cast<Dispatcher::Callback0>(callback_generic); | |
247 if (!(handler->*callback)(&ipc_info)) | |
248 break; | |
249 error = false; | |
250 break; | |
251 } | |
252 case 1: { | |
253 Dispatcher::Callback1 callback = | |
254 reinterpret_cast<Dispatcher::Callback1>(callback_generic); | |
255 if (!(handler->*callback)(&ipc_info, args[0])) | |
256 break; | |
257 error = false; | |
258 break; | |
259 } | |
260 case 2: { | |
261 Dispatcher::Callback2 callback = | |
262 reinterpret_cast<Dispatcher::Callback2>(callback_generic); | |
263 if (!(handler->*callback)(&ipc_info, args[0], args[1])) | |
264 break; | |
265 error = false; | |
266 break; | |
267 } | |
268 case 3: { | |
269 Dispatcher::Callback3 callback = | |
270 reinterpret_cast<Dispatcher::Callback3>(callback_generic); | |
271 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2])) | |
272 break; | |
273 error = false; | |
274 break; | |
275 } | |
276 case 4: { | |
277 Dispatcher::Callback4 callback = | |
278 reinterpret_cast<Dispatcher::Callback4>(callback_generic); | |
279 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], | |
280 args[3])) | |
281 break; | |
282 error = false; | |
283 break; | |
284 } | |
285 case 5: { | |
286 Dispatcher::Callback5 callback = | |
287 reinterpret_cast<Dispatcher::Callback5>(callback_generic); | |
288 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3], | |
289 args[4])) | |
290 break; | |
291 error = false; | |
292 break; | |
293 } | |
294 case 6: { | |
295 Dispatcher::Callback6 callback = | |
296 reinterpret_cast<Dispatcher::Callback6>(callback_generic); | |
297 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3], | |
298 args[4], args[5])) | |
299 break; | |
300 error = false; | |
301 break; | |
302 } | |
303 case 7: { | |
304 Dispatcher::Callback7 callback = | |
305 reinterpret_cast<Dispatcher::Callback7>(callback_generic); | |
306 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3], | |
307 args[4], args[5], args[6])) | |
308 break; | |
309 error = false; | |
310 break; | |
311 } | |
312 case 8: { | |
313 Dispatcher::Callback8 callback = | |
314 reinterpret_cast<Dispatcher::Callback8>(callback_generic); | |
315 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3], | |
316 args[4], args[5], args[6], args[7])) | |
317 break; | |
318 error = false; | |
319 break; | |
320 } | |
321 case 9: { | |
322 Dispatcher::Callback9 callback = | |
323 reinterpret_cast<Dispatcher::Callback9>(callback_generic); | |
324 if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3], | |
325 args[4], args[5], args[6], args[7], args[8])) | |
326 break; | |
327 error = false; | |
328 break; | |
329 } | |
330 default: { | |
331 NOTREACHED(); | |
332 break; | |
333 } | |
334 } | |
335 } | |
336 | |
337 if (error) { | |
338 if (handler) | |
339 SetCallError(SBOX_ERROR_FAILED_IPC, call_result); | |
340 } else { | |
341 memcpy(call_result, &ipc_info.return_info, sizeof(*call_result)); | |
342 SetCallSuccess(call_result); | |
343 if (params->IsInOut()) { | |
344 // Maybe the params got changed by the broker. We need to upadte the | |
345 // memory section. | |
346 memcpy(ipc_buffer, params.get(), output_size); | |
347 } | |
348 } | |
349 | |
350 ReleaseArgs(&ipc_params, args); | |
351 | |
352 return !error; | |
353 } | |
354 | |
355 // This function gets called by a thread from the thread pool when a | |
356 // ping event fires. The context is the same as passed in the RegisterWait() | |
357 // call above. | |
358 void __stdcall SharedMemIPCServer::ThreadPingEventReady(void* context, | |
359 unsigned char) { | |
360 if (NULL == context) { | |
361 DCHECK(false); | |
362 return; | |
363 } | |
364 ServerControl* service_context = reinterpret_cast<ServerControl*>(context); | |
365 // Since the event fired, the channel *must* be busy. Change to kAckChannel | |
366 // while we service it. | |
367 LONG last_state = | |
368 ::InterlockedCompareExchange(&service_context->channel->state, | |
369 kAckChannel, kBusyChannel); | |
370 if (kBusyChannel != last_state) { | |
371 DCHECK(false); | |
372 return; | |
373 } | |
374 | |
375 // Prepare the result structure. At this point we will return some result | |
376 // even if the IPC is invalid, malformed or has no handler. | |
377 CrossCallReturn call_result = {0}; | |
378 void* buffer = service_context->channel_buffer; | |
379 | |
380 InvokeCallback(service_context, buffer, &call_result); | |
381 | |
382 // Copy the answer back into the channel and signal the pong event. This | |
383 // should wake up the client so he can finish the the ipc cycle. | |
384 CrossCallParams* call_params = reinterpret_cast<CrossCallParams*>(buffer); | |
385 memcpy(call_params->GetCallReturn(), &call_result, sizeof(call_result)); | |
386 ::InterlockedExchange(&service_context->channel->state, kAckChannel); | |
387 ::SetEvent(service_context->pong_event); | |
388 } | |
389 | |
390 bool SharedMemIPCServer::MakeEvents(HANDLE* server_ping, HANDLE* server_pong, | |
391 HANDLE* client_ping, HANDLE* client_pong) { | |
392 // Note that the IPC client has no right to delete the events. That would | |
393 // cause problems. The server *owns* the events. | |
394 const DWORD kDesiredAccess = SYNCHRONIZE | EVENT_MODIFY_STATE; | |
395 | |
396 // The events are auto reset, and start not signaled. | |
397 *server_ping = ::CreateEventW(NULL, FALSE, FALSE, NULL); | |
398 if (!::DuplicateHandle(::GetCurrentProcess(), *server_ping, target_process_, | |
399 client_ping, kDesiredAccess, FALSE, 0)) { | |
400 return false; | |
401 } | |
402 *server_pong = ::CreateEventW(NULL, FALSE, FALSE, NULL); | |
403 if (!::DuplicateHandle(::GetCurrentProcess(), *server_pong, target_process_, | |
404 client_pong, kDesiredAccess, FALSE, 0)) { | |
405 return false; | |
406 } | |
407 return true; | |
408 } | |
409 | |
410 } // namespace sandbox | |
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