1 // Copyright (c) 2011 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 <algorithm>
6
7 #include "base/command_line.h"
8 #include "base/file_util.h"
9 #include "base/logging.h"
10 #include "base/mac/scoped_nsautorelease_pool.h"
11 #include "base/memory/singleton.h"
12 #include "base/path_service.h"
13 #include "base/process_util.h"
14 #include "base/sha1.h"
15 #include "base/string16.h"
16 #include "base/string_number_conversions.h"
17 #include "base/string_util.h"
18 #include "base/utf_string_conversions.h"
19 #include "base/version.h"
20 #include "chrome/common/chrome_constants.h"
21 #include "chrome/common/chrome_paths.h"
22 #include "chrome/common/chrome_switches.h"
23 #include "chrome/common/chrome_version_info.h"
24 #include "chrome/common/service_process_util.h"
25 #include "content/common/child_process_host.h"
26
27 #if !defined(OS_MACOSX)
28
29 namespace {
30
31 // This should be more than enough to hold a version string assuming each part
32 // of the version string is an int64.
33 const uint32 kMaxVersionStringLength = 256;
34
35 // The structure that gets written to shared memory.
36 struct ServiceProcessSharedData {
37 char service_process_version[kMaxVersionStringLength];
38 base::ProcessId service_process_pid;
39 };
40
41 // Gets the name of the shared memory used by the service process to write its
42 // version. The name is not versioned.
GetServiceProcessSharedMemName()43 std::string GetServiceProcessSharedMemName() {
44 return GetServiceProcessScopedName("_service_shmem");
45 }
46
47 enum ServiceProcessRunningState {
48 SERVICE_NOT_RUNNING,
49 SERVICE_OLDER_VERSION_RUNNING,
50 SERVICE_SAME_VERSION_RUNNING,
51 SERVICE_NEWER_VERSION_RUNNING,
52 };
53
GetServiceProcessRunningState(std::string * service_version_out,base::ProcessId * pid_out)54 ServiceProcessRunningState GetServiceProcessRunningState(
55 std::string* service_version_out, base::ProcessId* pid_out) {
56 std::string version;
57 if (!GetServiceProcessData(&version, pid_out))
58 return SERVICE_NOT_RUNNING;
59
60 #if defined(OS_POSIX)
61 // We only need to check for service running on POSIX because Windows cleans
62 // up shared memory files when an app crashes, so there isn't a chance of
63 // us reading bogus data from shared memory for an app that has died.
64 if (!CheckServiceProcessReady()) {
65 return SERVICE_NOT_RUNNING;
66 }
67 #endif // defined(OS_POSIX)
68
69 // At this time we have a version string. Set the out param if it exists.
70 if (service_version_out)
71 *service_version_out = version;
72
73 scoped_ptr<Version> service_version(Version::GetVersionFromString(version));
74 // If the version string is invalid, treat it like an older version.
75 if (!service_version.get())
76 return SERVICE_OLDER_VERSION_RUNNING;
77
78 // Get the version of the currently *running* instance of Chrome.
79 chrome::VersionInfo version_info;
80 if (!version_info.is_valid()) {
81 NOTREACHED() << "Failed to get current file version";
82 // Our own version is invalid. This is an error case. Pretend that we
83 // are out of date.
84 return SERVICE_NEWER_VERSION_RUNNING;
85 }
86 scoped_ptr<Version> running_version(Version::GetVersionFromString(
87 version_info.Version()));
88 if (!running_version.get()) {
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 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 = 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 // Gets the name of the service process IPC channel.
GetServiceProcessChannel()157 IPC::ChannelHandle GetServiceProcessChannel() {
158 return GetServiceProcessScopedVersionedName("_service_ipc");
159 }
160
161 #endif // !OS_MACOSX
162
ServiceProcessState()163 ServiceProcessState::ServiceProcessState() : state_(NULL) {
164 CreateAutoRunCommandLine();
165 CreateState();
166 }
167
~ServiceProcessState()168 ServiceProcessState::~ServiceProcessState() {
169 #if !defined(OS_MACOSX)
170 if (shared_mem_service_data_.get()) {
171 shared_mem_service_data_->Delete(GetServiceProcessSharedMemName());
172 }
173 #endif // !OS_MACOSX
174 TearDownState();
175 }
176
SignalStopped()177 void ServiceProcessState::SignalStopped() {
178 TearDownState();
179 shared_mem_service_data_.reset();
180 }
181
182 #if !defined(OS_MACOSX)
Initialize()183 bool ServiceProcessState::Initialize() {
184 if (!TakeSingletonLock()) {
185 return false;
186 }
187 // Now that we have the singleton, take care of killing an older version, if
188 // it exists.
189 if (!HandleOtherVersion())
190 return false;
191
192 // Write the version we are using to shared memory. This can be used by a
193 // newer service to signal us to exit.
194 return CreateSharedData();
195 }
196
HandleOtherVersion()197 bool ServiceProcessState::HandleOtherVersion() {
198 std::string running_version;
199 base::ProcessId process_id = 0;
200 ServiceProcessRunningState state =
201 GetServiceProcessRunningState(&running_version, &process_id);
202 switch (state) {
203 case SERVICE_SAME_VERSION_RUNNING:
204 case SERVICE_NEWER_VERSION_RUNNING:
205 return false;
206 case SERVICE_OLDER_VERSION_RUNNING:
207 // If an older version is running, kill it.
208 ForceServiceProcessShutdown(running_version, process_id);
209 break;
210 case SERVICE_NOT_RUNNING:
211 break;
212 }
213 return true;
214 }
215
CreateSharedData()216 bool ServiceProcessState::CreateSharedData() {
217 chrome::VersionInfo version_info;
218 if (!version_info.is_valid()) {
219 NOTREACHED() << "Failed to get current file version";
220 return false;
221 }
222 if (version_info.Version().length() >= kMaxVersionStringLength) {
223 NOTREACHED() << "Version string length is << " <<
224 version_info.Version().length() << "which is longer than" <<
225 kMaxVersionStringLength;
226 return false;
227 }
228
229 scoped_ptr<base::SharedMemory> shared_mem_service_data(
230 new base::SharedMemory());
231 if (!shared_mem_service_data.get())
232 return false;
233
234 uint32 alloc_size = sizeof(ServiceProcessSharedData);
235 if (!shared_mem_service_data->CreateNamed(GetServiceProcessSharedMemName(),
236 true, alloc_size))
237 return false;
238
239 if (!shared_mem_service_data->Map(alloc_size))
240 return false;
241
242 memset(shared_mem_service_data->memory(), 0, alloc_size);
243 ServiceProcessSharedData* shared_data =
244 reinterpret_cast<ServiceProcessSharedData*>(
245 shared_mem_service_data->memory());
246 memcpy(shared_data->service_process_version, version_info.Version().c_str(),
247 version_info.Version().length());
248 shared_data->service_process_pid = base::GetCurrentProcId();
249 shared_mem_service_data_.reset(shared_mem_service_data.release());
250 return true;
251 }
252
GetServiceProcessChannel()253 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
254 return ::GetServiceProcessChannel();
255 }
256
257 #endif // !OS_MACOSX
258
CreateAutoRunCommandLine()259 void ServiceProcessState::CreateAutoRunCommandLine() {
260 FilePath exe_path = ChildProcessHost::GetChildPath(false);
261 if (exe_path.empty()) {
262 NOTREACHED() << "Unable to get service process binary name.";
263 }
264 autorun_command_line_.reset(new CommandLine(exe_path));
265 autorun_command_line_->AppendSwitchASCII(switches::kProcessType,
266 switches::kServiceProcess);
267
268 // The user data directory is the only other flag we currently want to
269 // possibly store.
270 const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
271 FilePath user_data_dir =
272 browser_command_line.GetSwitchValuePath(switches::kUserDataDir);
273 if (!user_data_dir.empty())
274 autorun_command_line_->AppendSwitchPath(switches::kUserDataDir,
275 user_data_dir);
276 }
277