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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 "chrome/common/service_process_util.h"
6 
7 #include <algorithm>
8 
9 #include "base/command_line.h"
10 #include "base/logging.h"
11 #include "base/memory/singleton.h"
12 #include "base/path_service.h"
13 #include "base/sha1.h"
14 #include "base/strings/string16.h"
15 #include "base/strings/string_number_conversions.h"
16 #include "base/strings/string_util.h"
17 #include "base/strings/utf_string_conversions.h"
18 #include "base/version.h"
19 #include "chrome/common/chrome_constants.h"
20 #include "chrome/common/chrome_paths.h"
21 #include "chrome/common/chrome_switches.h"
22 #include "chrome/common/chrome_version_info.h"
23 #include "components/cloud_devices/common/cloud_devices_switches.h"
24 #include "content/public/common/content_paths.h"
25 #include "google_apis/gaia/gaia_switches.h"
26 #include "ui/base/ui_base_switches.h"
27 
28 #if !defined(OS_MACOSX)
29 
30 namespace {
31 
32 // This should be more than enough to hold a version string assuming each part
33 // of the version string is an int64.
34 const uint32 kMaxVersionStringLength = 256;
35 
36 // The structure that gets written to shared memory.
37 struct ServiceProcessSharedData {
38   char service_process_version[kMaxVersionStringLength];
39   base::ProcessId service_process_pid;
40 };
41 
42 // Gets the name of the shared memory used by the service process to write its
43 // version. The name is not versioned.
GetServiceProcessSharedMemName()44 std::string GetServiceProcessSharedMemName() {
45   return GetServiceProcessScopedName("_service_shmem");
46 }
47 
48 enum ServiceProcessRunningState {
49   SERVICE_NOT_RUNNING,
50   SERVICE_OLDER_VERSION_RUNNING,
51   SERVICE_SAME_VERSION_RUNNING,
52   SERVICE_NEWER_VERSION_RUNNING,
53 };
54 
GetServiceProcessRunningState(std::string * service_version_out,base::ProcessId * pid_out)55 ServiceProcessRunningState GetServiceProcessRunningState(
56     std::string* service_version_out, base::ProcessId* pid_out) {
57   std::string version;
58   if (!GetServiceProcessData(&version, pid_out))
59     return SERVICE_NOT_RUNNING;
60 
61 #if defined(OS_POSIX)
62   // We only need to check for service running on POSIX because Windows cleans
63   // up shared memory files when an app crashes, so there isn't a chance of
64   // us reading bogus data from shared memory for an app that has died.
65   if (!CheckServiceProcessReady()) {
66     return SERVICE_NOT_RUNNING;
67   }
68 #endif  // defined(OS_POSIX)
69 
70   // At this time we have a version string. Set the out param if it exists.
71   if (service_version_out)
72     *service_version_out = version;
73 
74   Version service_version(version);
75   // If the version string is invalid, treat it like an older version.
76   if (!service_version.IsValid())
77     return SERVICE_OLDER_VERSION_RUNNING;
78 
79   // Get the version of the currently *running* instance of Chrome.
80   chrome::VersionInfo version_info;
81   if (!version_info.is_valid()) {
82     NOTREACHED() << "Failed to get current file version";
83     // Our own version is invalid. This is an error case. Pretend that we
84     // are out of date.
85     return SERVICE_NEWER_VERSION_RUNNING;
86   }
87   Version running_version(version_info.Version());
88   if (!running_version.IsValid()) {
89     NOTREACHED() << "Failed to parse version info";
90     // Our own version is invalid. This is an error case. Pretend that we
91     // are out of date.
92     return SERVICE_NEWER_VERSION_RUNNING;
93   }
94 
95   if (running_version.CompareTo(service_version) > 0) {
96     return SERVICE_OLDER_VERSION_RUNNING;
97   } else if (service_version.CompareTo(running_version) > 0) {
98     return SERVICE_NEWER_VERSION_RUNNING;
99   }
100   return SERVICE_SAME_VERSION_RUNNING;
101 }
102 
103 }  // namespace
104 
105 // Return a name that is scoped to this instance of the service process. We
106 // use the hash of the user-data-dir as a scoping prefix. We can't use
107 // the user-data-dir itself as we have limits on the size of the lock names.
GetServiceProcessScopedName(const std::string & append_str)108 std::string GetServiceProcessScopedName(const std::string& append_str) {
109   base::FilePath user_data_dir;
110   PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
111 #if defined(OS_WIN)
112   std::string user_data_dir_path = base::WideToUTF8(user_data_dir.value());
113 #elif defined(OS_POSIX)
114   std::string user_data_dir_path = user_data_dir.value();
115 #endif  // defined(OS_WIN)
116   std::string hash = base::SHA1HashString(user_data_dir_path);
117   std::string hex_hash = base::HexEncode(hash.c_str(), hash.length());
118   return hex_hash + "." + append_str;
119 }
120 
121 // Return a name that is scoped to this instance of the service process. We
122 // use the user-data-dir and the version as a scoping prefix.
GetServiceProcessScopedVersionedName(const std::string & append_str)123 std::string GetServiceProcessScopedVersionedName(
124     const std::string& append_str) {
125   std::string versioned_str;
126   chrome::VersionInfo version_info;
127   DCHECK(version_info.is_valid());
128   versioned_str.append(version_info.Version());
129   versioned_str.append(append_str);
130   return GetServiceProcessScopedName(versioned_str);
131 }
132 
133 // Reads the named shared memory to get the shared data. Returns false if no
134 // matching shared memory was found.
GetServiceProcessData(std::string * version,base::ProcessId * pid)135 bool GetServiceProcessData(std::string* version, base::ProcessId* pid) {
136   scoped_ptr<base::SharedMemory> shared_mem_service_data;
137   shared_mem_service_data.reset(new base::SharedMemory());
138   ServiceProcessSharedData* service_data = NULL;
139   if (shared_mem_service_data.get() &&
140       shared_mem_service_data->Open(GetServiceProcessSharedMemName(), true) &&
141       shared_mem_service_data->Map(sizeof(ServiceProcessSharedData))) {
142     service_data = reinterpret_cast<ServiceProcessSharedData*>(
143         shared_mem_service_data->memory());
144     // Make sure the version in shared memory is null-terminated. If it is not,
145     // treat it as invalid.
146     if (version && memchr(service_data->service_process_version, '\0',
147                           sizeof(service_data->service_process_version)))
148       *version = service_data->service_process_version;
149     if (pid)
150       *pid = service_data->service_process_pid;
151     return true;
152   }
153   return false;
154 }
155 
156 #endif  // !OS_MACOSX
157 
CreateServiceProcessCommandLine()158 scoped_ptr<base::CommandLine> CreateServiceProcessCommandLine() {
159   base::FilePath exe_path;
160   PathService::Get(content::CHILD_PROCESS_EXE, &exe_path);
161   DCHECK(!exe_path.empty()) << "Unable to get service process binary name.";
162   scoped_ptr<base::CommandLine> command_line(new base::CommandLine(exe_path));
163   command_line->AppendSwitchASCII(switches::kProcessType,
164                                   switches::kServiceProcess);
165   static const char* const kSwitchesToCopy[] = {
166     switches::kCloudPrintSetupProxy,
167     switches::kCloudPrintURL,
168     switches::kCloudPrintXmppEndpoint,
169 #if defined(OS_WIN)
170     switches::kEnableCloudPrintXps,
171 #endif
172     switches::kEnableLogging,
173     switches::kIgnoreUrlFetcherCertRequests,
174     switches::kLang,
175     switches::kLoggingLevel,
176     switches::kLsoUrl,
177     switches::kNoServiceAutorun,
178     switches::kUserDataDir,
179     switches::kV,
180     switches::kVModule,
181     switches::kWaitForDebugger,
182   };
183 
184   command_line->CopySwitchesFrom(*base::CommandLine::ForCurrentProcess(),
185                                  kSwitchesToCopy,
186                                  arraysize(kSwitchesToCopy));
187   return command_line.Pass();
188 }
189 
ServiceProcessState()190 ServiceProcessState::ServiceProcessState() : state_(NULL) {
191   autorun_command_line_ = CreateServiceProcessCommandLine();
192   CreateState();
193 }
194 
~ServiceProcessState()195 ServiceProcessState::~ServiceProcessState() {
196 #if !defined(OS_MACOSX)
197   if (shared_mem_service_data_.get()) {
198     shared_mem_service_data_->Delete(GetServiceProcessSharedMemName());
199   }
200 #endif  // !OS_MACOSX
201   TearDownState();
202 }
203 
SignalStopped()204 void ServiceProcessState::SignalStopped() {
205   TearDownState();
206   shared_mem_service_data_.reset();
207 }
208 
209 #if !defined(OS_MACOSX)
Initialize()210 bool ServiceProcessState::Initialize() {
211   if (!TakeSingletonLock()) {
212     return false;
213   }
214   // Now that we have the singleton, take care of killing an older version, if
215   // it exists.
216   if (!HandleOtherVersion())
217     return false;
218 
219   // Write the version we are using to shared memory. This can be used by a
220   // newer service to signal us to exit.
221   return CreateSharedData();
222 }
223 
HandleOtherVersion()224 bool ServiceProcessState::HandleOtherVersion() {
225   std::string running_version;
226   base::ProcessId process_id = 0;
227   ServiceProcessRunningState state =
228       GetServiceProcessRunningState(&running_version, &process_id);
229   switch (state) {
230     case SERVICE_SAME_VERSION_RUNNING:
231     case SERVICE_NEWER_VERSION_RUNNING:
232       return false;
233     case SERVICE_OLDER_VERSION_RUNNING:
234       // If an older version is running, kill it.
235       ForceServiceProcessShutdown(running_version, process_id);
236       break;
237     case SERVICE_NOT_RUNNING:
238       break;
239   }
240   return true;
241 }
242 
CreateSharedData()243 bool ServiceProcessState::CreateSharedData() {
244   chrome::VersionInfo version_info;
245   if (!version_info.is_valid()) {
246     NOTREACHED() << "Failed to get current file version";
247     return false;
248   }
249   if (version_info.Version().length() >= kMaxVersionStringLength) {
250     NOTREACHED() << "Version string length is << " <<
251         version_info.Version().length() << "which is longer than" <<
252         kMaxVersionStringLength;
253     return false;
254   }
255 
256   scoped_ptr<base::SharedMemory> shared_mem_service_data(
257       new base::SharedMemory());
258   if (!shared_mem_service_data.get())
259     return false;
260 
261   uint32 alloc_size = sizeof(ServiceProcessSharedData);
262   // TODO(viettrungluu): Named shared memory is deprecated (crbug.com/345734).
263   if (!shared_mem_service_data->CreateNamedDeprecated
264           (GetServiceProcessSharedMemName(), true, alloc_size))
265     return false;
266 
267   if (!shared_mem_service_data->Map(alloc_size))
268     return false;
269 
270   memset(shared_mem_service_data->memory(), 0, alloc_size);
271   ServiceProcessSharedData* shared_data =
272       reinterpret_cast<ServiceProcessSharedData*>(
273           shared_mem_service_data->memory());
274   memcpy(shared_data->service_process_version, version_info.Version().c_str(),
275          version_info.Version().length());
276   shared_data->service_process_pid = base::GetCurrentProcId();
277   shared_mem_service_data_.reset(shared_mem_service_data.release());
278   return true;
279 }
280 
GetServiceProcessChannel()281 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
282   return ::GetServiceProcessChannel();
283 }
284 
285 #endif  // !OS_MACOSX
286