chrome/app/client_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 <windows.h>
   6 #include <shlwapi.h>
   7
   8 #include "base/command_line.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/debug/trace_event.h"
  11 #include "base/environment.h"
  12 #include "base/file_version_info.h"
  13 #include "base/lazy_instance.h"
  14 #include "base/logging.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/rand_util.h"  // For PreRead experiment.
  17 #include "base/sha1.h"  // For PreRead experiment.
  18 #include "base/strings/string16.h"
  19 #include "base/strings/string_util.h"
  20 #include "base/strings/stringprintf.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "base/version.h"
  23 #include "base/win/windows_version.h"
  24 #include "chrome/app/chrome_crash_reporter_client.h"
  25 #include "chrome/app/client_util.h"
  26 #include "chrome/app/image_pre_reader_win.h"
  27 #include "chrome/common/chrome_constants.h"
  28 #include "chrome/common/chrome_result_codes.h"
  29 #include "chrome/common/chrome_switches.h"
  30 #include "chrome/common/env_vars.h"
  31 #include "chrome/installer/util/google_update_constants.h"
  32 #include "chrome/installer/util/google_update_settings.h"
  33 #include "chrome/installer/util/install_util.h"
  34 #include "chrome/installer/util/util_constants.h"
  35 #include "components/crash/app/breakpad_win.h"
  36 #include "components/crash/app/crash_reporter_client.h"
  37 #include "components/metrics/client_info.h"
  38 #include "content/public/app/startup_helper_win.h"
  39 #include "sandbox/win/src/sandbox.h"
  40
  41 namespace {
  42 // The entry point signature of chrome.dll.
  43 typedef int (*DLL_MAIN)(HINSTANCE, sandbox::SandboxInterfaceInfo*);
  44
  45 typedef void (*RelaunchChromeBrowserWithNewCommandLineIfNeededFunc)();
  46
  47 base::LazyInstance<chrome::ChromeCrashReporterClient>::Leaky
  48     g_chrome_crash_client = LAZY_INSTANCE_INITIALIZER;
  49
  50 // Returns true if the build date for this module precedes the expiry date
  51 // for the pre-read experiment.
  52 bool PreReadExperimentIsActive() {
  53   const int kPreReadExpiryYear = 2014;
  54   const int kPreReadExpiryMonth = 7;
  55   const int kPreReadExpiryDay = 1;
  56   const char kBuildTimeStr[] = __DATE__ " " __TIME__;
  57
  58   // Get the timestamp of the build.
  59   base::Time build_time;
  60   bool result = base::Time::FromString(kBuildTimeStr, &build_time);
  61   DCHECK(result);
  62
  63   // Get the timestamp at which the experiment expires.
  64   base::Time::Exploded exploded = {0};
  65   exploded.year = kPreReadExpiryYear;
  66   exploded.month = kPreReadExpiryMonth;
  67   exploded.day_of_month = kPreReadExpiryDay;
  68   base::Time expiration_time = base::Time::FromLocalExploded(exploded);
  69
  70   // Return true if the build time predates the expiration time..
  71   return build_time < expiration_time;
  72 }
  73
  74 // Get random unit values, i.e., in the range (0, 1), denoting a die-toss for
  75 // being in an experiment population and experimental group thereof.
  76 void GetPreReadPopulationAndGroup(double* population, double* group) {
  77   // By default we use the metrics id for the user as stable pseudo-random
  78   // input to a hash.
  79   scoped_ptr<metrics::ClientInfo> client_info =
  80       GoogleUpdateSettings::LoadMetricsClientInfo();
  81
  82   // If this user has no metrics id, we fall back to a purely random value per
  83   // browser session.
  84   const size_t kLength = 16;
  85   std::string random_value(client_info ? client_info->client_id
  86                                        : base::RandBytesAsString(kLength));
  87
  88   // To interpret the value as a random number we hash it and read the first 8
  89   // bytes of the hash as a unit-interval representing a die-toss for being in
  90   // the experiment population and the second 8 bytes as a die-toss for being
  91   // in various experiment groups.
  92   unsigned char sha1_hash[base::kSHA1Length];
  93   base::SHA1HashBytes(
  94       reinterpret_cast<const unsigned char*>(random_value.c_str()),
  95       random_value.size() * sizeof(random_value[0]),
  96       sha1_hash);
  97   COMPILE_ASSERT(2 * sizeof(uint64) < sizeof(sha1_hash), need_more_data);
  98   const uint64* random_bits = reinterpret_cast<uint64*>(&sha1_hash[0]);
  99
 100   // Convert the bits into unit-intervals and return.
 101   *population = base::BitsToOpenEndedUnitInterval(random_bits[0]);
 102   *group = base::BitsToOpenEndedUnitInterval(random_bits[1]);
 103 }
 104
 105 // Gets the amount of pre-read to use as well as the experiment group in which
 106 // the user falls.
 107 size_t InitPreReadPercentage() {
 108   // By default use the old behaviour: read 100%.
 109   const int kDefaultPercentage = 100;
 110   const char kDefaultFormatStr[] = "%d-pct-default";
 111   const char kControlFormatStr[] = "%d-pct-control";
 112   const char kGroupFormatStr[] = "%d-pct";
 113
 114   COMPILE_ASSERT(kDefaultPercentage <= 100, default_percentage_too_large);
 115   COMPILE_ASSERT(kDefaultPercentage % 5 == 0, default_percentage_not_mult_5);
 116
 117   // Roll the dice to determine if this user is in the experiment and if so,
 118   // in which experimental group.
 119   double population = 0.0;
 120   double group = 0.0;
 121   GetPreReadPopulationAndGroup(&population, &group);
 122
 123   // We limit experiment populations to 1% of the Stable and 10% of each of
 124   // the other channels.
 125   const base::string16 channel(GoogleUpdateSettings::GetChromeChannel(
 126       GoogleUpdateSettings::IsSystemInstall()));
 127   double threshold = (channel == installer::kChromeChannelStable) ? 0.01 : 0.10;
 128
 129   // If the experiment has expired use the default pre-read level. Otherwise,
 130   // those not in the experiment population also use the default pre-read level.
 131   size_t value = kDefaultPercentage;
 132   const char* format_str = kDefaultFormatStr;
 133   if (PreReadExperimentIsActive() && (population <= threshold)) {
 134     // We divide the experiment population into groups pre-reading at 5 percent
 135     // increments in the range [0, 100].
 136     value = static_cast<size_t>(group * 21.0) * 5;
 137     DCHECK_LE(value, 100u);
 138     DCHECK_EQ(0u, value % 5);
 139     format_str =
 140         (value == kDefaultPercentage) ? kControlFormatStr : kGroupFormatStr;
 141   }
 142
 143   // Generate the group name corresponding to this percentage value.
 144   std::string group_name;
 145   base::SStringPrintf(&group_name, format_str, value);
 146
 147   // Persist the group name to the environment so that it can be used for
 148   // reporting.
 149   scoped_ptr<base::Environment> env(base::Environment::Create());
 150   env->SetVar(chrome::kPreReadEnvironmentVariable, group_name);
 151
 152   // Return the percentage value to be used.
 153   return value;
 154 }
 155
 156 // Expects that |dir| has a trailing backslash. |dir| is modified so it
 157 // contains the full path that was tried. Caller must check for the return
 158 // value not being null to determine if this path contains a valid dll.
 159 HMODULE LoadModuleWithDirectory(base::string16* dir,
 160                                 const wchar_t* dll_name,
 161                                 bool pre_read) {
 162   ::SetCurrentDirectoryW(dir->c_str());
 163   dir->append(dll_name);
 164
 165   if (pre_read) {
 166 #if !defined(WIN_DISABLE_PREREAD)
 167     // We pre-read the binary to warm the memory caches (fewer hard faults to
 168     // page parts of the binary in).
 169     const size_t kStepSize = 1024 * 1024;
 170     size_t percentage = InitPreReadPercentage();
 171     ImagePreReader::PartialPreReadImage(dir->c_str(), percentage, kStepSize);
 172 #endif
 173   }
 174
 175   return ::LoadLibraryExW(dir->c_str(), NULL,
 176                           LOAD_WITH_ALTERED_SEARCH_PATH);
 177 }
 178
 179 void RecordDidRun(const base::string16& dll_path) {
 180   bool system_level = !InstallUtil::IsPerUserInstall(dll_path.c_str());
 181   GoogleUpdateSettings::UpdateDidRunState(true, system_level);
 182 }
 183
 184 void ClearDidRun(const base::string16& dll_path) {
 185   bool system_level = !InstallUtil::IsPerUserInstall(dll_path.c_str());
 186   GoogleUpdateSettings::UpdateDidRunState(false, system_level);
 187 }
 188
 189 bool InMetroMode() {
 190   return (wcsstr(
 191       ::GetCommandLineW(), L" -ServerName:DefaultBrowserServer") != NULL);
 192 }
 193
 194 typedef int (*InitMetro)();
 195
 196 }  // namespace
 197
 198 base::string16 GetExecutablePath() {
 199   wchar_t path[MAX_PATH];
 200   ::GetModuleFileNameW(NULL, path, MAX_PATH);
 201   if (!::PathRemoveFileSpecW(path))
 202     return base::string16();
 203   base::string16 exe_path(path);
 204   return exe_path.append(1, L'\\');
 205 }
 206
 207 base::string16 GetCurrentModuleVersion() {
 208   scoped_ptr<FileVersionInfo> file_version_info(
 209       FileVersionInfo::CreateFileVersionInfoForCurrentModule());
 210   if (file_version_info.get()) {
 211     base::string16 version_string(file_version_info->file_version());
 212     if (Version(base::UTF16ToASCII(version_string)).IsValid())
 213       return version_string;
 214   }
 215   return base::string16();
 216 }
 217
 218 //=============================================================================
 219
 220 MainDllLoader::MainDllLoader()
 221   : dll_(NULL), metro_mode_(InMetroMode()) {
 222 }
 223
 224 MainDllLoader::~MainDllLoader() {
 225 }
 226
 227 // Loading chrome is an interesting affair. First we try loading from the
 228 // current directory to support run-what-you-compile and other development
 229 // scenarios.
 230 // If that fails then we look at the version resource in the current
 231 // module. This is the expected path for chrome.exe browser instances in an
 232 // installed build.
 233 HMODULE MainDllLoader::Load(base::string16* version,
 234                             base::string16* out_file) {
 235   const base::string16 executable_dir(GetExecutablePath());
 236   *out_file = executable_dir;
 237
 238   const wchar_t* dll_name = metro_mode_ ?
 239       installer::kChromeMetroDll :
 240 #if !defined(CHROME_MULTIPLE_DLL)
 241       installer::kChromeDll;
 242 #else
 243       (process_type_ == "service")  || process_type_.empty() ?
 244           installer::kChromeDll :
 245           installer::kChromeChildDll;
 246 #endif
 247   const bool pre_read = !metro_mode_;
 248   HMODULE dll = LoadModuleWithDirectory(out_file, dll_name, pre_read);
 249   if (!dll) {
 250     base::string16 version_string(GetCurrentModuleVersion());
 251     if (version_string.empty()) {
 252       LOG(ERROR) << "No valid Chrome version found";
 253       return NULL;
 254     }
 255     *out_file = executable_dir;
 256     *version = version_string;
 257     out_file->append(version_string).append(1, L'\\');
 258     dll = LoadModuleWithDirectory(out_file, dll_name, pre_read);
 259     if (!dll) {
 260       PLOG(ERROR) << "Failed to load Chrome DLL from " << *out_file;
 261       return NULL;
 262     }
 263   }
 264
 265   DCHECK(dll);
 266   return dll;
 267 }
 268
 269 // Launching is a matter of loading the right dll, setting the CHROME_VERSION
 270 // environment variable and just calling the entry point. Derived classes can
 271 // add custom code in the OnBeforeLaunch callback.
 272 int MainDllLoader::Launch(HINSTANCE instance) {
 273   const CommandLine& cmd_line = *CommandLine::ForCurrentProcess();
 274   process_type_ = cmd_line.GetSwitchValueASCII(switches::kProcessType);
 275
 276   base::string16 version;
 277   base::string16 file;
 278
 279   if (metro_mode_) {
 280     HMODULE metro_dll = Load(&version, &file);
 281     if (!metro_dll)
 282       return chrome::RESULT_CODE_MISSING_DATA;
 283
 284     InitMetro chrome_metro_main =
 285         reinterpret_cast<InitMetro>(::GetProcAddress(metro_dll, "InitMetro"));
 286     return chrome_metro_main();
 287   }
 288
 289   // Initialize the sandbox services.
 290   sandbox::SandboxInterfaceInfo sandbox_info = {0};
 291   content::InitializeSandboxInfo(&sandbox_info);
 292
 293   crash_reporter::SetCrashReporterClient(g_chrome_crash_client.Pointer());
 294   bool exit_now = true;
 295   if (process_type_.empty()) {
 296     if (breakpad::ShowRestartDialogIfCrashed(&exit_now)) {
 297       // We restarted because of a previous crash. Ask user if we should
 298       // Relaunch. Only for the browser process. See crbug.com/132119.
 299       if (exit_now)
 300         return content::RESULT_CODE_NORMAL_EXIT;
 301     }
 302   }
 303   breakpad::InitCrashReporter(process_type_);
 304
 305   dll_ = Load(&version, &file);
 306   if (!dll_)
 307     return chrome::RESULT_CODE_MISSING_DATA;
 308
 309   scoped_ptr<base::Environment> env(base::Environment::Create());
 310   env->SetVar(chrome::kChromeVersionEnvVar, base::WideToUTF8(version));
 311
 312   OnBeforeLaunch(file);
 313   DLL_MAIN chrome_main =
 314       reinterpret_cast<DLL_MAIN>(::GetProcAddress(dll_, "ChromeMain"));
 315   int rc = chrome_main(instance, &sandbox_info);
 316   return OnBeforeExit(rc, file);
 317 }
 318
 319 void MainDllLoader::RelaunchChromeBrowserWithNewCommandLineIfNeeded() {
 320   if (!dll_)
 321     return;
 322
 323   RelaunchChromeBrowserWithNewCommandLineIfNeededFunc relaunch_function =
 324       reinterpret_cast<RelaunchChromeBrowserWithNewCommandLineIfNeededFunc>(
 325           ::GetProcAddress(dll_,
 326                            "RelaunchChromeBrowserWithNewCommandLineIfNeeded"));
 327   if (!relaunch_function) {
 328     LOG(ERROR) << "Could not find exported function "
 329                << "RelaunchChromeBrowserWithNewCommandLineIfNeeded";
 330   } else {
 331     relaunch_function();
 332   }
 333 }
 334
 335 //=============================================================================
 336
 337 class ChromeDllLoader : public MainDllLoader {
 338  protected:
 339   virtual void OnBeforeLaunch(const base::string16& dll_path) {
 340     RecordDidRun(dll_path);
 341   }
 342
 343   virtual int OnBeforeExit(int return_code, const base::string16& dll_path) {
 344     // NORMAL_EXIT_CANCEL is used for experiments when the user cancels
 345     // so we need to reset the did_run signal so omaha does not count
 346     // this run as active usage.
 347     if (chrome::RESULT_CODE_NORMAL_EXIT_CANCEL == return_code) {
 348       ClearDidRun(dll_path);
 349     }
 350     return return_code;
 351   }
 352 };
 353
 354 //=============================================================================
 355
 356 class ChromiumDllLoader : public MainDllLoader {
 357  protected:
 358   virtual void OnBeforeLaunch(const base::string16& dll_path) OVERRIDE {
 359   }
 360   virtual int OnBeforeExit(int return_code,
 361                            const base::string16& dll_path) OVERRIDE {
 362     return return_code;
 363   }
 364 };
 365
 366 MainDllLoader* MakeMainDllLoader() {
 367 #if defined(GOOGLE_CHROME_BUILD)
 368   return new ChromeDllLoader();
 369 #else
 370   return new ChromiumDllLoader();
 371 #endif
 372 }