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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 "sandbox/src/broker_services.h" | |
| 6 | |
| 7 #include "base/logging.h" | |
| 8 #include "base/memory/scoped_ptr.h" | |
| 9 #include "base/threading/platform_thread.h" | |
| 10 #include "base/win/scoped_handle.h" | |
| 11 #include "base/win/scoped_process_information.h" | |
| 12 #include "sandbox/src/sandbox_policy_base.h" | |
| 13 #include "sandbox/src/sandbox.h" | |
| 14 #include "sandbox/src/target_process.h" | |
| 15 #include "sandbox/src/win2k_threadpool.h" | |
| 16 #include "sandbox/src/win_utils.h" | |
| 17 | |
| 18 namespace { | |
| 19 | |
| 20 // Utility function to associate a completion port to a job object. | |
| 21 bool AssociateCompletionPort(HANDLE job, HANDLE port, void* key) { | |
| 22 JOBOBJECT_ASSOCIATE_COMPLETION_PORT job_acp = { key, port }; | |
| 23 return ::SetInformationJobObject(job, | |
| 24 JobObjectAssociateCompletionPortInformation, | |
| 25 &job_acp, sizeof(job_acp))? true : false; | |
| 26 } | |
| 27 | |
| 28 // Utility function to do the cleanup necessary when something goes wrong | |
| 29 // while in SpawnTarget and we must terminate the target process. | |
| 30 sandbox::ResultCode SpawnCleanup(sandbox::TargetProcess* target, DWORD error) { | |
| 31 if (0 == error) | |
| 32 error = ::GetLastError(); | |
| 33 | |
| 34 target->Terminate(); | |
| 35 delete target; | |
| 36 ::SetLastError(error); | |
| 37 return sandbox::SBOX_ERROR_GENERIC; | |
| 38 } | |
| 39 | |
| 40 // the different commands that you can send to the worker thread that | |
| 41 // executes TargetEventsThread(). | |
| 42 enum { | |
| 43 THREAD_CTRL_NONE, | |
| 44 THREAD_CTRL_REMOVE_PEER, | |
| 45 THREAD_CTRL_QUIT, | |
| 46 THREAD_CTRL_LAST, | |
| 47 }; | |
| 48 | |
| 49 // Helper structure that allows the Broker to associate a job notification | |
| 50 // with a job object and with a policy. | |
| 51 struct JobTracker { | |
| 52 HANDLE job; | |
| 53 sandbox::PolicyBase* policy; | |
| 54 JobTracker(HANDLE cjob, sandbox::PolicyBase* cpolicy) | |
| 55 : job(cjob), policy(cpolicy) { | |
| 56 } | |
| 57 }; | |
| 58 | |
| 59 // Helper structure that allows the broker to track peer processes | |
| 60 struct PeerTracker { | |
| 61 HANDLE wait_object; | |
| 62 base::win::ScopedHandle process; | |
| 63 DWORD id; | |
| 64 HANDLE job_port; | |
| 65 PeerTracker(DWORD process_id, HANDLE broker_job_port) | |
| 66 : wait_object(NULL), id(process_id), job_port(broker_job_port) { | |
| 67 } | |
| 68 }; | |
| 69 | |
| 70 void DeregisterPeerTracker(PeerTracker* peer) { | |
| 71 // Deregistration shouldn't fail, but we leak rather than crash if it does. | |
| 72 if (::UnregisterWaitEx(peer->wait_object, INVALID_HANDLE_VALUE)) { | |
| 73 delete peer; | |
| 74 } else { | |
| 75 NOTREACHED(); | |
| 76 } | |
| 77 } | |
| 78 | |
| 79 } // namespace | |
| 80 | |
| 81 namespace sandbox { | |
| 82 | |
| 83 BrokerServicesBase::BrokerServicesBase() | |
| 84 : thread_pool_(NULL), job_port_(NULL), no_targets_(NULL), | |
| 85 job_thread_(NULL) { | |
| 86 } | |
| 87 | |
| 88 // The broker uses a dedicated worker thread that services the job completion | |
| 89 // port to perform policy notifications and associated cleanup tasks. | |
| 90 ResultCode BrokerServicesBase::Init() { | |
| 91 if ((NULL != job_port_) || (NULL != thread_pool_)) | |
| 92 return SBOX_ERROR_UNEXPECTED_CALL; | |
| 93 | |
| 94 ::InitializeCriticalSection(&lock_); | |
| 95 | |
| 96 job_port_ = ::CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0); | |
| 97 if (NULL == job_port_) | |
| 98 return SBOX_ERROR_GENERIC; | |
| 99 | |
| 100 no_targets_ = ::CreateEventW(NULL, TRUE, FALSE, NULL); | |
| 101 | |
| 102 job_thread_ = ::CreateThread(NULL, 0, // Default security and stack. | |
| 103 TargetEventsThread, this, NULL, NULL); | |
| 104 if (NULL == job_thread_) | |
| 105 return SBOX_ERROR_GENERIC; | |
| 106 | |
| 107 return SBOX_ALL_OK; | |
| 108 } | |
| 109 | |
| 110 // The destructor should only be called when the Broker process is terminating. | |
| 111 // Since BrokerServicesBase is a singleton, this is called from the CRT | |
| 112 // termination handlers, if this code lives on a DLL it is called during | |
| 113 // DLL_PROCESS_DETACH in other words, holding the loader lock, so we cannot | |
| 114 // wait for threads here. | |
| 115 BrokerServicesBase::~BrokerServicesBase() { | |
| 116 // If there is no port Init() was never called successfully. | |
| 117 if (!job_port_) | |
| 118 return; | |
| 119 | |
| 120 // Closing the port causes, that no more Job notifications are delivered to | |
| 121 // the worker thread and also causes the thread to exit. This is what we | |
| 122 // want to do since we are going to close all outstanding Jobs and notifying | |
| 123 // the policy objects ourselves. | |
| 124 ::PostQueuedCompletionStatus(job_port_, 0, THREAD_CTRL_QUIT, FALSE); | |
| 125 ::CloseHandle(job_port_); | |
| 126 | |
| 127 if (WAIT_TIMEOUT == ::WaitForSingleObject(job_thread_, 1000)) { | |
| 128 // Cannot clean broker services. | |
| 129 NOTREACHED(); | |
| 130 return; | |
| 131 } | |
| 132 | |
| 133 JobTrackerList::iterator it; | |
| 134 for (it = tracker_list_.begin(); it != tracker_list_.end(); ++it) { | |
| 135 JobTracker* tracker = (*it); | |
| 136 FreeResources(tracker); | |
| 137 delete tracker; | |
| 138 } | |
| 139 ::CloseHandle(job_thread_); | |
| 140 delete thread_pool_; | |
| 141 ::CloseHandle(no_targets_); | |
| 142 | |
| 143 // Cancel the wait events and delete remaining peer trackers. | |
| 144 for (PeerTrackerMap::iterator it = peer_map_.begin(); | |
| 145 it != peer_map_.end(); ++it) { | |
| 146 DeregisterPeerTracker(it->second); | |
| 147 } | |
| 148 | |
| 149 // If job_port_ isn't NULL, assumes that the lock has been initialized. | |
| 150 if (job_port_) | |
| 151 ::DeleteCriticalSection(&lock_); | |
| 152 } | |
| 153 | |
| 154 TargetPolicy* BrokerServicesBase::CreatePolicy() { | |
| 155 // If you change the type of the object being created here you must also | |
| 156 // change the downcast to it in SpawnTarget(). | |
| 157 return new PolicyBase; | |
| 158 } | |
| 159 | |
| 160 void BrokerServicesBase::FreeResources(JobTracker* tracker) { | |
| 161 if (NULL != tracker->policy) { | |
| 162 BOOL res = ::TerminateJobObject(tracker->job, SBOX_ALL_OK); | |
| 163 DCHECK(res); | |
| 164 // Closing the job causes the target process to be destroyed so this | |
| 165 // needs to happen before calling OnJobEmpty(). | |
| 166 res = ::CloseHandle(tracker->job); | |
| 167 DCHECK(res); | |
| 168 // In OnJobEmpty() we don't actually use the job handle directly. | |
| 169 tracker->policy->OnJobEmpty(tracker->job); | |
| 170 tracker->policy->Release(); | |
| 171 tracker->policy = NULL; | |
| 172 } | |
| 173 } | |
| 174 | |
| 175 // The worker thread stays in a loop waiting for asynchronous notifications | |
| 176 // from the job objects. Right now we only care about knowing when the last | |
| 177 // process on a job terminates, but in general this is the place to tell | |
| 178 // the policy about events. | |
| 179 DWORD WINAPI BrokerServicesBase::TargetEventsThread(PVOID param) { | |
| 180 if (NULL == param) | |
| 181 return 1; | |
| 182 | |
| 183 base::PlatformThread::SetName("BrokerEvent"); | |
| 184 | |
| 185 BrokerServicesBase* broker = reinterpret_cast<BrokerServicesBase*>(param); | |
| 186 HANDLE port = broker->job_port_; | |
| 187 HANDLE no_targets = broker->no_targets_; | |
| 188 | |
| 189 int target_counter = 0; | |
| 190 ::ResetEvent(no_targets); | |
| 191 | |
| 192 while (true) { | |
| 193 DWORD events = 0; | |
| 194 ULONG_PTR key = 0; | |
| 195 LPOVERLAPPED ovl = NULL; | |
| 196 | |
| 197 if (!::GetQueuedCompletionStatus(port, &events, &key, &ovl, INFINITE)) | |
| 198 // this call fails if the port has been closed before we have a | |
| 199 // chance to service the last packet which is 'exit' anyway so | |
| 200 // this is not an error. | |
| 201 return 1; | |
| 202 | |
| 203 if (key > THREAD_CTRL_LAST) { | |
| 204 // The notification comes from a job object. There are nine notifications | |
| 205 // that jobs can send and some of them depend on the job attributes set. | |
| 206 JobTracker* tracker = reinterpret_cast<JobTracker*>(key); | |
| 207 | |
| 208 switch (events) { | |
| 209 case JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO: { | |
| 210 // The job object has signaled that the last process associated | |
| 211 // with it has terminated. Assuming there is no way for a process | |
| 212 // to appear out of thin air in this job, it safe to assume that | |
| 213 // we can tell the policy to destroy the target object, and for | |
| 214 // us to release our reference to the policy object. | |
| 215 FreeResources(tracker); | |
| 216 break; | |
| 217 } | |
| 218 | |
| 219 case JOB_OBJECT_MSG_NEW_PROCESS: { | |
| 220 ++target_counter; | |
| 221 if (1 == target_counter) { | |
| 222 ::ResetEvent(no_targets); | |
| 223 } | |
| 224 break; | |
| 225 } | |
| 226 | |
| 227 case JOB_OBJECT_MSG_EXIT_PROCESS: | |
| 228 case JOB_OBJECT_MSG_ABNORMAL_EXIT_PROCESS: { | |
| 229 { | |
| 230 AutoLock lock(&broker->lock_); | |
| 231 broker->child_process_ids_.erase(reinterpret_cast<DWORD>(ovl)); | |
| 232 } | |
| 233 --target_counter; | |
| 234 if (0 == target_counter) | |
| 235 ::SetEvent(no_targets); | |
| 236 | |
| 237 DCHECK(target_counter >= 0); | |
| 238 break; | |
| 239 } | |
| 240 | |
| 241 case JOB_OBJECT_MSG_ACTIVE_PROCESS_LIMIT: { | |
| 242 break; | |
| 243 } | |
| 244 | |
| 245 default: { | |
| 246 NOTREACHED(); | |
| 247 break; | |
| 248 } | |
| 249 } | |
| 250 } else if (THREAD_CTRL_REMOVE_PEER == key) { | |
| 251 // Remove a process from our list of peers. | |
| 252 AutoLock lock(&broker->lock_); | |
| 253 PeerTrackerMap::iterator it = | |
| 254 broker->peer_map_.find(reinterpret_cast<DWORD>(ovl)); | |
| 255 DeregisterPeerTracker(it->second); | |
| 256 broker->peer_map_.erase(it); | |
| 257 } else if (THREAD_CTRL_QUIT == key) { | |
| 258 // The broker object is being destroyed so the thread needs to exit. | |
| 259 return 0; | |
| 260 } else { | |
| 261 // We have not implemented more commands. | |
| 262 NOTREACHED(); | |
| 263 } | |
| 264 } | |
| 265 | |
| 266 NOTREACHED(); | |
| 267 return 0; | |
| 268 } | |
| 269 | |
| 270 // SpawnTarget does all the interesting sandbox setup and creates the target | |
| 271 // process inside the sandbox. | |
| 272 ResultCode BrokerServicesBase::SpawnTarget(const wchar_t* exe_path, | |
| 273 const wchar_t* command_line, | |
| 274 TargetPolicy* policy, | |
| 275 PROCESS_INFORMATION* target_info) { | |
| 276 if (!exe_path) | |
| 277 return SBOX_ERROR_BAD_PARAMS; | |
| 278 | |
| 279 if (!policy) | |
| 280 return SBOX_ERROR_BAD_PARAMS; | |
| 281 | |
| 282 // Even though the resources touched by SpawnTarget can be accessed in | |
| 283 // multiple threads, the method itself cannot be called from more than | |
| 284 // 1 thread. This is to protect the global variables used while setting up | |
| 285 // the child process. | |
| 286 static DWORD thread_id = ::GetCurrentThreadId(); | |
| 287 DCHECK(thread_id == ::GetCurrentThreadId()); | |
| 288 | |
| 289 AutoLock lock(&lock_); | |
| 290 | |
| 291 // This downcast is safe as long as we control CreatePolicy() | |
| 292 PolicyBase* policy_base = static_cast<PolicyBase*>(policy); | |
| 293 | |
| 294 // Construct the tokens and the job object that we are going to associate | |
| 295 // with the soon to be created target process. | |
| 296 HANDLE initial_token_temp; | |
| 297 HANDLE lockdown_token_temp; | |
| 298 DWORD win_result = policy_base->MakeTokens(&initial_token_temp, | |
| 299 &lockdown_token_temp); | |
| 300 base::win::ScopedHandle initial_token(initial_token_temp); | |
| 301 base::win::ScopedHandle lockdown_token(lockdown_token_temp); | |
| 302 | |
| 303 if (ERROR_SUCCESS != win_result) | |
| 304 return SBOX_ERROR_GENERIC; | |
| 305 | |
| 306 HANDLE job_temp; | |
| 307 win_result = policy_base->MakeJobObject(&job_temp); | |
| 308 base::win::ScopedHandle job(job_temp); | |
| 309 if (ERROR_SUCCESS != win_result) | |
| 310 return SBOX_ERROR_GENERIC; | |
| 311 | |
| 312 if (ERROR_ALREADY_EXISTS == ::GetLastError()) | |
| 313 return SBOX_ERROR_GENERIC; | |
| 314 | |
| 315 // Construct the thread pool here in case it is expensive. | |
| 316 // The thread pool is shared by all the targets | |
| 317 if (NULL == thread_pool_) | |
| 318 thread_pool_ = new Win2kThreadPool(); | |
| 319 | |
| 320 // Create the TargetProces object and spawn the target suspended. Note that | |
| 321 // Brokerservices does not own the target object. It is owned by the Policy. | |
| 322 base::win::ScopedProcessInformation process_info; | |
| 323 TargetProcess* target = new TargetProcess(initial_token.Take(), | |
| 324 lockdown_token.Take(), | |
| 325 job, | |
| 326 thread_pool_); | |
| 327 | |
| 328 std::wstring desktop = policy_base->GetAlternateDesktop(); | |
| 329 | |
| 330 win_result = target->Create(exe_path, command_line, | |
| 331 desktop.empty() ? NULL : desktop.c_str(), | |
| 332 &process_info); | |
| 333 if (ERROR_SUCCESS != win_result) | |
| 334 return SpawnCleanup(target, win_result); | |
| 335 | |
| 336 // Now the policy is the owner of the target. | |
| 337 if (!policy_base->AddTarget(target)) { | |
| 338 return SpawnCleanup(target, 0); | |
| 339 } | |
| 340 | |
| 341 // We are going to keep a pointer to the policy because we'll call it when | |
| 342 // the job object generates notifications using the completion port. | |
| 343 policy_base->AddRef(); | |
| 344 scoped_ptr<JobTracker> tracker(new JobTracker(job.Take(), policy_base)); | |
| 345 if (!AssociateCompletionPort(tracker->job, job_port_, tracker.get())) | |
| 346 return SpawnCleanup(target, 0); | |
| 347 // Save the tracker because in cleanup we might need to force closing | |
| 348 // the Jobs. | |
| 349 tracker_list_.push_back(tracker.release()); | |
| 350 child_process_ids_.insert(process_info.process_id()); | |
| 351 | |
| 352 *target_info = process_info.Take(); | |
| 353 return SBOX_ALL_OK; | |
| 354 } | |
| 355 | |
| 356 | |
| 357 ResultCode BrokerServicesBase::WaitForAllTargets() { | |
| 358 ::WaitForSingleObject(no_targets_, INFINITE); | |
| 359 return SBOX_ALL_OK; | |
| 360 } | |
| 361 | |
| 362 bool BrokerServicesBase::IsActiveTarget(DWORD process_id) { | |
| 363 AutoLock lock(&lock_); | |
| 364 return child_process_ids_.find(process_id) != child_process_ids_.end() || | |
| 365 peer_map_.find(process_id) != peer_map_.end(); | |
| 366 } | |
| 367 | |
| 368 VOID CALLBACK BrokerServicesBase::RemovePeer(PVOID parameter, BOOLEAN timeout) { | |
| 369 PeerTracker* peer = reinterpret_cast<PeerTracker*>(parameter); | |
| 370 // Don't check the return code because we this may fail (safely) at shutdown. | |
| 371 ::PostQueuedCompletionStatus(peer->job_port, 0, THREAD_CTRL_REMOVE_PEER, | |
| 372 reinterpret_cast<LPOVERLAPPED>(peer->id)); | |
| 373 } | |
| 374 | |
| 375 ResultCode BrokerServicesBase::AddTargetPeer(HANDLE peer_process) { | |
| 376 scoped_ptr<PeerTracker> peer(new PeerTracker(::GetProcessId(peer_process), | |
| 377 job_port_)); | |
| 378 if (!peer->id) | |
| 379 return SBOX_ERROR_GENERIC; | |
| 380 | |
| 381 HANDLE process_handle; | |
| 382 if (!::DuplicateHandle(::GetCurrentProcess(), peer_process, | |
| 383 ::GetCurrentProcess(), &process_handle, | |
| 384 SYNCHRONIZE, FALSE, 0)) { | |
| 385 return SBOX_ERROR_GENERIC; | |
| 386 } | |
| 387 peer->process.Set(process_handle); | |
| 388 | |
| 389 AutoLock lock(&lock_); | |
| 390 if (!peer_map_.insert(std::make_pair(peer->id, peer.get())).second) | |
| 391 return SBOX_ERROR_BAD_PARAMS; | |
| 392 | |
| 393 if (!::RegisterWaitForSingleObject( | |
| 394 &peer->wait_object, peer->process, RemovePeer, peer.get(), INFINITE, | |
| 395 WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD)) { | |
| 396 peer_map_.erase(peer->id); | |
| 397 return SBOX_ERROR_GENERIC; | |
| 398 } | |
| 399 | |
| 400 // Release the pointer since it will be cleaned up by the callback. | |
| 401 peer.release(); | |
| 402 return SBOX_ALL_OK; | |
| 403 } | |
| 404 | |
| 405 } // namespace sandbox | |
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Chromium Code Reviews
Issue 10783004:
Move Windows Sandbox, trybots version (don't commit me!) (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src