src/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 "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.
  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   chrome::VersionInfo version_info;
  81   Version running_version(version_info.Version());
  82   if (!running_version.IsValid()) {
  83     NOTREACHED() << "Failed to parse version info";
  84     // Our own version is invalid. This is an error case. Pretend that we
  85     // are out of date.
  86     return SERVICE_NEWER_VERSION_RUNNING;
  87   }
  88
  89   if (running_version.CompareTo(service_version) > 0) {
  90     return SERVICE_OLDER_VERSION_RUNNING;
  91   } else if (service_version.CompareTo(running_version) > 0) {
  92     return SERVICE_NEWER_VERSION_RUNNING;
  93   }
  94   return SERVICE_SAME_VERSION_RUNNING;
  95 }
  96
  97 }  // namespace
  98
  99 // Return a name that is scoped to this instance of the service process. We
 100 // use the hash of the user-data-dir as a scoping prefix. We can't use
 101 // the user-data-dir itself as we have limits on the size of the lock names.
 102 std::string GetServiceProcessScopedName(const std::string& append_str) {
 103   base::FilePath user_data_dir;
 104   PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
 105 #if defined(OS_WIN)
 106   std::string user_data_dir_path = base::WideToUTF8(user_data_dir.value());
 107 #elif defined(OS_POSIX)
 108   std::string user_data_dir_path = user_data_dir.value();
 109 #endif  // defined(OS_WIN)
 110   std::string hash = base::SHA1HashString(user_data_dir_path);
 111   std::string hex_hash = base::HexEncode(hash.c_str(), hash.length());
 112   return hex_hash + "." + append_str;
 113 }
 114
 115 // Return a name that is scoped to this instance of the service process. We
 116 // use the user-data-dir and the version as a scoping prefix.
 117 std::string GetServiceProcessScopedVersionedName(
 118     const std::string& append_str) {
 119   std::string versioned_str;
 120   chrome::VersionInfo version_info;
 121   versioned_str.append(version_info.Version());
 122   versioned_str.append(append_str);
 123   return GetServiceProcessScopedName(versioned_str);
 124 }
 125
 126 // Reads the named shared memory to get the shared data. Returns false if no
 127 // matching shared memory was found.
 128 bool GetServiceProcessData(std::string* version, base::ProcessId* pid) {
 129   scoped_ptr<base::SharedMemory> shared_mem_service_data;
 130   shared_mem_service_data.reset(new base::SharedMemory());
 131   ServiceProcessSharedData* service_data = NULL;
 132   if (shared_mem_service_data.get() &&
 133       shared_mem_service_data->Open(GetServiceProcessSharedMemName(), true) &&
 134       shared_mem_service_data->Map(sizeof(ServiceProcessSharedData))) {
 135     service_data = reinterpret_cast<ServiceProcessSharedData*>(
 136         shared_mem_service_data->memory());
 137     // Make sure the version in shared memory is null-terminated. If it is not,
 138     // treat it as invalid.
 139     if (version && memchr(service_data->service_process_version, '\0',
 140                           sizeof(service_data->service_process_version)))
 141       *version = service_data->service_process_version;
 142     if (pid)
 143       *pid = service_data->service_process_pid;
 144     return true;
 145   }
 146   return false;
 147 }
 148
 149 #endif  // !OS_MACOSX
 150
 151 scoped_ptr<base::CommandLine> CreateServiceProcessCommandLine() {
 152   base::FilePath exe_path;
 153   PathService::Get(content::CHILD_PROCESS_EXE, &exe_path);
 154   DCHECK(!exe_path.empty()) << "Unable to get service process binary name.";
 155   scoped_ptr<base::CommandLine> command_line(new base::CommandLine(exe_path));
 156   command_line->AppendSwitchASCII(switches::kProcessType,
 157                                   switches::kServiceProcess);
 158   static const char* const kSwitchesToCopy[] = {
 159     switches::kCloudPrintSetupProxy,
 160     switches::kCloudPrintURL,
 161     switches::kCloudPrintXmppEndpoint,
 162 #if defined(OS_WIN)
 163     switches::kEnableCloudPrintXps,
 164 #endif
 165     switches::kEnableLogging,
 166     switches::kIgnoreUrlFetcherCertRequests,
 167     switches::kLang,
 168     switches::kLoggingLevel,
 169     switches::kLsoUrl,
 170     switches::kNoServiceAutorun,
 171     switches::kUserDataDir,
 172     switches::kV,
 173     switches::kVModule,
 174     switches::kWaitForDebugger,
 175   };
 176
 177   command_line->CopySwitchesFrom(*base::CommandLine::ForCurrentProcess(),
 178                                  kSwitchesToCopy,
 179                                  arraysize(kSwitchesToCopy));
 180   return command_line.Pass();
 181 }
 182
 183 ServiceProcessState::ServiceProcessState() : state_(NULL) {
 184   autorun_command_line_ = CreateServiceProcessCommandLine();
 185   CreateState();
 186 }
 187
 188 ServiceProcessState::~ServiceProcessState() {
 189 #if !defined(OS_MACOSX)
 190   if (shared_mem_service_data_.get()) {
 191     shared_mem_service_data_->Delete(GetServiceProcessSharedMemName());
 192   }
 193 #endif  // !OS_MACOSX
 194   TearDownState();
 195 }
 196
 197 void ServiceProcessState::SignalStopped() {
 198   TearDownState();
 199   shared_mem_service_data_.reset();
 200 }
 201
 202 #if !defined(OS_MACOSX)
 203 bool ServiceProcessState::Initialize() {
 204   if (!TakeSingletonLock()) {
 205     return false;
 206   }
 207   // Now that we have the singleton, take care of killing an older version, if
 208   // it exists.
 209   if (!HandleOtherVersion())
 210     return false;
 211
 212   // Write the version we are using to shared memory. This can be used by a
 213   // newer service to signal us to exit.
 214   return CreateSharedData();
 215 }
 216
 217 bool ServiceProcessState::HandleOtherVersion() {
 218   std::string running_version;
 219   base::ProcessId process_id = 0;
 220   ServiceProcessRunningState state =
 221       GetServiceProcessRunningState(&running_version, &process_id);
 222   switch (state) {
 223     case SERVICE_SAME_VERSION_RUNNING:
 224     case SERVICE_NEWER_VERSION_RUNNING:
 225       return false;
 226     case SERVICE_OLDER_VERSION_RUNNING:
 227       // If an older version is running, kill it.
 228       ForceServiceProcessShutdown(running_version, process_id);
 229       break;
 230     case SERVICE_NOT_RUNNING:
 231       break;
 232   }
 233   return true;
 234 }
 235
 236 bool ServiceProcessState::CreateSharedData() {
 237   chrome::VersionInfo version_info;
 238   if (version_info.Version().length() >= kMaxVersionStringLength) {
 239     NOTREACHED() << "Version string length is << " <<
 240         version_info.Version().length() << "which is longer than" <<
 241         kMaxVersionStringLength;
 242     return false;
 243   }
 244
 245   scoped_ptr<base::SharedMemory> shared_mem_service_data(
 246       new base::SharedMemory());
 247   if (!shared_mem_service_data.get())
 248     return false;
 249
 250   uint32 alloc_size = sizeof(ServiceProcessSharedData);
 251   // TODO(viettrungluu): Named shared memory is deprecated (crbug.com/345734).
 252   if (!shared_mem_service_data->CreateNamedDeprecated
 253           (GetServiceProcessSharedMemName(), true, alloc_size))
 254     return false;
 255
 256   if (!shared_mem_service_data->Map(alloc_size))
 257     return false;
 258
 259   memset(shared_mem_service_data->memory(), 0, alloc_size);
 260   ServiceProcessSharedData* shared_data =
 261       reinterpret_cast<ServiceProcessSharedData*>(
 262           shared_mem_service_data->memory());
 263   memcpy(shared_data->service_process_version, version_info.Version().c_str(),
 264          version_info.Version().length());
 265   shared_data->service_process_pid = base::GetCurrentProcId();
 266   shared_mem_service_data_.reset(shared_mem_service_data.release());
 267   return true;
 268 }
 269
 270 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
 271   return ::GetServiceProcessChannel();
 272 }
 273
 274 #endif  // !OS_MACOSX