chrome/common/service_process_util.cc

   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 "components/cloud_devices/common/cloud_devices_switches.h"
  23 #include "components/version_info/version_info.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.
  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
  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   Version running_version(version_info::GetVersionNumber());
  81   if (!running_version.IsValid()) {
  82     NOTREACHED() << "Failed to parse version info";
  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
  88   if (running_version.CompareTo(service_version) > 0) {
  89     return SERVICE_OLDER_VERSION_RUNNING;
  90   } else if (service_version.CompareTo(running_version) > 0) {
  91     return SERVICE_NEWER_VERSION_RUNNING;
  92   }
  93   return SERVICE_SAME_VERSION_RUNNING;
  94 }
  95
  96 }  // namespace
  97
  98
  99 // Return a name that is scoped to this instance of the service process. We
 100 // use the user-data-dir and the version as a scoping prefix.
 101 std::string GetServiceProcessScopedVersionedName(
 102     const std::string& append_str) {
 103   std::string versioned_str;
 104   versioned_str.append(version_info::GetVersionNumber());
 105   versioned_str.append(append_str);
 106   return GetServiceProcessScopedName(versioned_str);
 107 }
 108
 109 // Reads the named shared memory to get the shared data. Returns false if no
 110 // matching shared memory was found.
 111 bool GetServiceProcessData(std::string* version, base::ProcessId* pid) {
 112   scoped_ptr<base::SharedMemory> shared_mem_service_data;
 113   shared_mem_service_data.reset(new base::SharedMemory());
 114   ServiceProcessSharedData* service_data = NULL;
 115   if (shared_mem_service_data.get() &&
 116       shared_mem_service_data->Open(GetServiceProcessSharedMemName(), true) &&
 117       shared_mem_service_data->Map(sizeof(ServiceProcessSharedData))) {
 118     service_data = reinterpret_cast<ServiceProcessSharedData*>(
 119         shared_mem_service_data->memory());
 120     // Make sure the version in shared memory is null-terminated. If it is not,
 121     // treat it as invalid.
 122     if (version && memchr(service_data->service_process_version, '\0',
 123                           sizeof(service_data->service_process_version)))
 124       *version = service_data->service_process_version;
 125     if (pid)
 126       *pid = service_data->service_process_pid;
 127     return true;
 128   }
 129   return false;
 130 }
 131
 132 #endif  // !OS_MACOSX
 133
 134 // Return a name that is scoped to this instance of the service process. We
 135 // use the hash of the user-data-dir as a scoping prefix. We can't use
 136 // the user-data-dir itself as we have limits on the size of the lock names.
 137 std::string GetServiceProcessScopedName(const std::string& append_str) {
 138   base::FilePath user_data_dir;
 139   PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
 140 #if defined(OS_WIN)
 141   std::string user_data_dir_path = base::WideToUTF8(user_data_dir.value());
 142 #elif defined(OS_POSIX)
 143   std::string user_data_dir_path = user_data_dir.value();
 144 #endif  // defined(OS_WIN)
 145   std::string hash = base::SHA1HashString(user_data_dir_path);
 146   std::string hex_hash = base::HexEncode(hash.c_str(), hash.length());
 147   return hex_hash + "." + append_str;
 148 }
 149
 150 scoped_ptr<base::CommandLine> CreateServiceProcessCommandLine() {
 151   base::FilePath exe_path;
 152   PathService::Get(content::CHILD_PROCESS_EXE, &exe_path);
 153   DCHECK(!exe_path.empty()) << "Unable to get service process binary name.";
 154   scoped_ptr<base::CommandLine> command_line(new base::CommandLine(exe_path));
 155   command_line->AppendSwitchASCII(switches::kProcessType,
 156                                   switches::kServiceProcess);
 157   static const char* const kSwitchesToCopy[] = {
 158     switches::kCloudPrintSetupProxy,
 159     switches::kCloudPrintURL,
 160     switches::kCloudPrintXmppEndpoint,
 161 #if defined(OS_WIN)
 162     switches::kEnableCloudPrintXps,
 163 #endif
 164     switches::kEnableLogging,
 165     switches::kIgnoreUrlFetcherCertRequests,
 166     switches::kLang,
 167     switches::kLoggingLevel,
 168     switches::kLsoUrl,
 169     switches::kNoServiceAutorun,
 170     switches::kUserDataDir,
 171     switches::kV,
 172     switches::kVModule,
 173     switches::kWaitForDebugger,
 174   };
 175
 176   command_line->CopySwitchesFrom(*base::CommandLine::ForCurrentProcess(),
 177                                  kSwitchesToCopy,
 178                                  arraysize(kSwitchesToCopy));
 179   return command_line.Pass();
 180 }
 181
 182 ServiceProcessState::ServiceProcessState() : state_(NULL) {
 183   autorun_command_line_ = CreateServiceProcessCommandLine();
 184   CreateState();
 185 }
 186
 187 ServiceProcessState::~ServiceProcessState() {
 188 #if !defined(OS_MACOSX)
 189   if (shared_mem_service_data_.get()) {
 190     shared_mem_service_data_->Delete(GetServiceProcessSharedMemName());
 191   }
 192 #endif  // !OS_MACOSX
 193   TearDownState();
 194 }
 195
 196 void ServiceProcessState::SignalStopped() {
 197   TearDownState();
 198   shared_mem_service_data_.reset();
 199 }
 200
 201 #if !defined(OS_MACOSX)
 202 bool ServiceProcessState::Initialize() {
 203   if (!TakeSingletonLock()) {
 204     return false;
 205   }
 206   // Now that we have the singleton, take care of killing an older version, if
 207   // it exists.
 208   if (!HandleOtherVersion())
 209     return false;
 210
 211   // Write the version we are using to shared memory. This can be used by a
 212   // newer service to signal us to exit.
 213   return CreateSharedData();
 214 }
 215
 216 bool ServiceProcessState::HandleOtherVersion() {
 217   std::string running_version;
 218   base::ProcessId process_id = 0;
 219   ServiceProcessRunningState state =
 220       GetServiceProcessRunningState(&running_version, &process_id);
 221   switch (state) {
 222     case SERVICE_SAME_VERSION_RUNNING:
 223     case SERVICE_NEWER_VERSION_RUNNING:
 224       return false;
 225     case SERVICE_OLDER_VERSION_RUNNING:
 226       // If an older version is running, kill it.
 227       ForceServiceProcessShutdown(running_version, process_id);
 228       break;
 229     case SERVICE_NOT_RUNNING:
 230       break;
 231   }
 232   return true;
 233 }
 234
 235 bool ServiceProcessState::CreateSharedData() {
 236   if (version_info::GetVersionNumber().length() >= kMaxVersionStringLength) {
 237     NOTREACHED() << "Version string length is << "
 238                  << version_info::GetVersionNumber().length()
 239                  << " which is longer than" << kMaxVersionStringLength;
 240     return false;
 241   }
 242
 243   scoped_ptr<base::SharedMemory> shared_mem_service_data(
 244       new base::SharedMemory());
 245   if (!shared_mem_service_data.get())
 246     return false;
 247
 248   uint32 alloc_size = sizeof(ServiceProcessSharedData);
 249   // TODO(viettrungluu): Named shared memory is deprecated (crbug.com/345734).
 250   if (!shared_mem_service_data->CreateNamedDeprecated
 251           (GetServiceProcessSharedMemName(), true, alloc_size))
 252     return false;
 253
 254   if (!shared_mem_service_data->Map(alloc_size))
 255     return false;
 256
 257   memset(shared_mem_service_data->memory(), 0, alloc_size);
 258   ServiceProcessSharedData* shared_data =
 259       reinterpret_cast<ServiceProcessSharedData*>(
 260           shared_mem_service_data->memory());
 261   memcpy(shared_data->service_process_version,
 262          version_info::GetVersionNumber().c_str(),
 263          version_info::GetVersionNumber().length());
 264   shared_data->service_process_pid = base::GetCurrentProcId();
 265   shared_mem_service_data_.reset(shared_mem_service_data.release());
 266   return true;
 267 }
 268
 269 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
 270   return ::GetServiceProcessChannel();
 271 }
 272
 273 #endif  // !OS_MACOSX