chrome/browser/extensions/updater/local_extension_cache.cc

   1 // Copyright 2014 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/browser/extensions/updater/local_extension_cache.h"
   6
   7 #include "base/bind.h"
   8 #include "base/files/file_enumerator.h"
   9 #include "base/files/file_util.h"
  10 #include "base/sequenced_task_runner.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/sys_info.h"
  13 #include "base/version.h"
  14 #include "components/crx_file/id_util.h"
  15 #include "content/public/browser/browser_thread.h"
  16
  17 namespace extensions {
  18 namespace {
  19
  20 // File name extension for CRX files (not case sensitive).
  21 const char kCRXFileExtension[] = ".crx";
  22
  23 // Delay between checks for flag file presence when waiting for the cache to
  24 // become ready.
  25 const int64_t kCacheStatusPollingDelayMs = 1000;
  26
  27 }  // namespace
  28
  29 const char LocalExtensionCache::kCacheReadyFlagFileName[] = ".initialized";
  30
  31 LocalExtensionCache::LocalExtensionCache(
  32     const base::FilePath& cache_dir,
  33     uint64 max_cache_size,
  34     const base::TimeDelta& max_cache_age,
  35     const scoped_refptr<base::SequencedTaskRunner>& backend_task_runner)
  36     : cache_dir_(cache_dir),
  37       max_cache_size_(max_cache_size),
  38       min_cache_age_(base::Time::Now() - max_cache_age),
  39       backend_task_runner_(backend_task_runner),
  40       state_(kUninitialized),
  41       weak_ptr_factory_(this),
  42       cache_status_polling_delay_(
  43           base::TimeDelta::FromMilliseconds(kCacheStatusPollingDelayMs)) {
  44 }
  45
  46 LocalExtensionCache::~LocalExtensionCache() {
  47   if (state_ == kReady)
  48     CleanUp();
  49 }
  50
  51 void LocalExtensionCache::Init(bool wait_for_cache_initialization,
  52                                const base::Closure& callback) {
  53   DCHECK_EQ(state_, kUninitialized);
  54
  55   state_ = kWaitInitialization;
  56   if (wait_for_cache_initialization)
  57     CheckCacheStatus(callback);
  58   else
  59     CheckCacheContents(callback);
  60 }
  61
  62 void LocalExtensionCache::Shutdown(const base::Closure& callback) {
  63   DCHECK_NE(state_, kShutdown);
  64   if (state_ == kReady)
  65     CleanUp();
  66   state_ = kShutdown;
  67   backend_task_runner_->PostTaskAndReply(FROM_HERE,
  68       base::Bind(&base::DoNothing), callback);
  69 }
  70
  71 bool LocalExtensionCache::GetExtension(const std::string& id,
  72                                        base::FilePath* file_path,
  73                                        std::string* version) {
  74   if (state_ != kReady)
  75     return false;
  76
  77   CacheMap::iterator it = cached_extensions_.find(id);
  78   if (it == cached_extensions_.end())
  79     return false;
  80
  81   if (file_path) {
  82     *file_path = it->second.file_path;
  83
  84     // If caller is not interesting in file_path, extension is not used.
  85     base::Time now = base::Time::Now();
  86     backend_task_runner_->PostTask(FROM_HERE,
  87         base::Bind(&LocalExtensionCache::BackendMarkFileUsed,
  88         it->second.file_path, now));
  89     it->second.last_used = now;
  90   }
  91
  92   if (version)
  93     *version = it->second.version;
  94
  95   return true;
  96 }
  97
  98 void LocalExtensionCache::PutExtension(const std::string& id,
  99                                        const base::FilePath& file_path,
 100                                        const std::string& version,
 101                                        const PutExtensionCallback& callback) {
 102   if (state_ != kReady) {
 103     callback.Run(file_path, true);
 104     return;
 105   }
 106
 107   Version version_validator(version);
 108   if (!version_validator.IsValid()) {
 109     LOG(ERROR) << "Extension " << id << " has bad version " << version;
 110     callback.Run(file_path, true);
 111     return;
 112   }
 113
 114   CacheMap::iterator it = cached_extensions_.find(id);
 115   if (it != cached_extensions_.end()) {
 116     Version new_version(version);
 117     Version prev_version(it->second.version);
 118     if (new_version.CompareTo(prev_version) <= 0) {
 119       LOG(WARNING) << "Cache contains newer or the same version "
 120                    << prev_version.GetString() << " for extension "
 121                    << id << " version " << version;
 122       callback.Run(file_path, true);
 123       return;
 124     }
 125   }
 126
 127   backend_task_runner_->PostTask(
 128       FROM_HERE,
 129       base::Bind(&LocalExtensionCache::BackendInstallCacheEntry,
 130                   weak_ptr_factory_.GetWeakPtr(),
 131                   cache_dir_,
 132                   id,
 133                   file_path,
 134                   version,
 135                   callback));
 136 }
 137
 138 bool LocalExtensionCache::RemoveExtension(const std::string& id) {
 139   if (state_ != kReady)
 140     return false;
 141
 142   CacheMap::iterator it = cached_extensions_.find(id);
 143   if (it == cached_extensions_.end())
 144     return false;
 145
 146   backend_task_runner_->PostTask(
 147       FROM_HERE,
 148       base::Bind(
 149           &LocalExtensionCache::BackendRemoveCacheEntry, cache_dir_, id));
 150
 151   cached_extensions_.erase(it);
 152   return true;
 153 }
 154
 155 bool LocalExtensionCache::GetStatistics(uint64* cache_size,
 156                                         size_t* extensions_count) {
 157   if (state_ != kReady)
 158     return false;
 159
 160   *cache_size = 0;
 161   for (CacheMap::iterator it = cached_extensions_.begin();
 162        it != cached_extensions_.end(); ++it) {
 163     *cache_size += it->second.size;
 164   }
 165   *extensions_count = cached_extensions_.size();
 166
 167   return true;
 168 }
 169
 170 void LocalExtensionCache::SetCacheStatusPollingDelayForTests(
 171     const base::TimeDelta& delay) {
 172   cache_status_polling_delay_ = delay;
 173 }
 174
 175 void LocalExtensionCache::CheckCacheStatus(const base::Closure& callback) {
 176   if (state_ == kShutdown) {
 177     callback.Run();
 178     return;
 179   }
 180
 181   backend_task_runner_->PostTask(
 182       FROM_HERE,
 183       base::Bind(&LocalExtensionCache::BackendCheckCacheStatus,
 184                   weak_ptr_factory_.GetWeakPtr(),
 185                   cache_dir_,
 186                   callback));
 187 }
 188
 189 // static
 190 void LocalExtensionCache::BackendCheckCacheStatus(
 191     base::WeakPtr<LocalExtensionCache> local_cache,
 192     const base::FilePath& cache_dir,
 193     const base::Closure& callback) {
 194   const bool exists =
 195       base::PathExists(cache_dir.AppendASCII(kCacheReadyFlagFileName));
 196
 197   static bool first_check = true;
 198   if (first_check && !exists && !base::SysInfo::IsRunningOnChromeOS()) {
 199     LOG(WARNING) << "Extensions will not be installed from update URLs until "
 200                  << cache_dir.AppendASCII(kCacheReadyFlagFileName).value()
 201                  << " exists.";
 202   }
 203   first_check = false;
 204
 205   content::BrowserThread::PostTask(
 206       content::BrowserThread::UI,
 207       FROM_HERE,
 208       base::Bind(&LocalExtensionCache::OnCacheStatusChecked,
 209                  local_cache,
 210                  exists,
 211                  callback));
 212 }
 213
 214 void LocalExtensionCache::OnCacheStatusChecked(bool ready,
 215                                                const base::Closure& callback) {
 216   if (state_ == kShutdown) {
 217     callback.Run();
 218     return;
 219   }
 220
 221   if (ready) {
 222     CheckCacheContents(callback);
 223   } else {
 224     content::BrowserThread::PostDelayedTask(
 225         content::BrowserThread::UI,
 226         FROM_HERE,
 227         base::Bind(&LocalExtensionCache::CheckCacheStatus,
 228                    weak_ptr_factory_.GetWeakPtr(),
 229                    callback),
 230         cache_status_polling_delay_);
 231   }
 232 }
 233
 234 void LocalExtensionCache::CheckCacheContents(const base::Closure& callback) {
 235   DCHECK_EQ(state_, kWaitInitialization);
 236   backend_task_runner_->PostTask(
 237       FROM_HERE,
 238       base::Bind(&LocalExtensionCache::BackendCheckCacheContents,
 239                  weak_ptr_factory_.GetWeakPtr(),
 240                  cache_dir_,
 241                  callback));
 242 }
 243
 244 // static
 245 void LocalExtensionCache::BackendCheckCacheContents(
 246     base::WeakPtr<LocalExtensionCache> local_cache,
 247     const base::FilePath& cache_dir,
 248     const base::Closure& callback) {
 249   scoped_ptr<CacheMap> cache_content(new CacheMap);
 250   BackendCheckCacheContentsInternal(cache_dir, cache_content.get());
 251   content::BrowserThread::PostTask(
 252       content::BrowserThread::UI,
 253       FROM_HERE,
 254       base::Bind(&LocalExtensionCache::OnCacheContentsChecked,
 255                  local_cache,
 256                  base::Passed(&cache_content),
 257                  callback));
 258 }
 259
 260 // static
 261 void LocalExtensionCache::BackendCheckCacheContentsInternal(
 262     const base::FilePath& cache_dir,
 263     CacheMap* cache_content) {
 264   // Start by verifying that the cache_dir exists.
 265   if (!base::DirectoryExists(cache_dir)) {
 266     // Create it now.
 267     if (!base::CreateDirectory(cache_dir)) {
 268       LOG(ERROR) << "Failed to create cache directory at "
 269                  << cache_dir.value();
 270     }
 271
 272     // Nothing else to do. Cache is empty.
 273     return;
 274   }
 275
 276   // Enumerate all the files in the cache |cache_dir|, including directories
 277   // and symlinks. Each unrecognized file will be erased.
 278   int types = base::FileEnumerator::FILES | base::FileEnumerator::DIRECTORIES;
 279   base::FileEnumerator enumerator(cache_dir, false /* recursive */, types);
 280   for (base::FilePath path = enumerator.Next();
 281        !path.empty(); path = enumerator.Next()) {
 282     base::FileEnumerator::FileInfo info = enumerator.GetInfo();
 283     std::string basename = path.BaseName().value();
 284
 285     if (info.IsDirectory() || base::IsLink(info.GetName())) {
 286       LOG(ERROR) << "Erasing bad file in cache directory: " << basename;
 287       base::DeleteFile(path, true /* recursive */);
 288       continue;
 289     }
 290
 291     // Skip flag file that indicates that cache is ready.
 292     if (basename == kCacheReadyFlagFileName)
 293       continue;
 294
 295     // crx files in the cache are named <extension-id>-<version>.crx.
 296     std::string id;
 297     std::string version;
 298     if (EndsWith(basename, kCRXFileExtension, false /* case-sensitive */)) {
 299       size_t n = basename.find('-');
 300       if (n != std::string::npos && n + 1 < basename.size() - 4) {
 301         id = basename.substr(0, n);
 302         // Size of |version| = total size - "<id>" - "-" - ".crx"
 303         version = basename.substr(n + 1, basename.size() - 5 - id.size());
 304       }
 305     }
 306
 307     // Enforce a lower-case id.
 308     id = base::StringToLowerASCII(id);
 309     if (!crx_file::id_util::IdIsValid(id)) {
 310       LOG(ERROR) << "Bad extension id in cache: " << id;
 311       id.clear();
 312     }
 313
 314     if (!Version(version).IsValid()) {
 315       LOG(ERROR) << "Bad extension version in cache: " << version;
 316       version.clear();
 317     }
 318
 319     if (id.empty() || version.empty()) {
 320       LOG(ERROR) << "Invalid file in cache, erasing: " << basename;
 321       base::DeleteFile(path, true /* recursive */);
 322       continue;
 323     }
 324
 325     VLOG(1) << "Found cached version " << version
 326             << " for extension id " << id;
 327
 328     CacheMap::iterator it = cache_content->find(id);
 329     if (it != cache_content->end()) {
 330       // |cache_content| already has version for this ID. Removed older one.
 331       Version curr_version(version);
 332       Version prev_version(it->second.version);
 333       if (prev_version.CompareTo(curr_version) <= 0) {
 334         base::DeleteFile(base::FilePath(it->second.file_path),
 335                          true /* recursive */);
 336         cache_content->erase(id);
 337         VLOG(1) << "Remove older version " << it->second.version
 338                 << " for extension id " << id;
 339       } else {
 340         base::DeleteFile(path, true /* recursive */);
 341         VLOG(1) << "Remove older version " << version
 342                 << " for extension id " << id;
 343         continue;
 344       }
 345     }
 346
 347     cache_content->insert(std::make_pair(id, CacheItemInfo(
 348         version, info.GetLastModifiedTime(), info.GetSize(), path)));
 349   }
 350 }
 351
 352 void LocalExtensionCache::OnCacheContentsChecked(
 353     scoped_ptr<CacheMap> cache_content,
 354     const base::Closure& callback) {
 355   cache_content->swap(cached_extensions_);
 356   state_ = kReady;
 357   callback.Run();
 358 }
 359
 360 // static
 361 void LocalExtensionCache::BackendMarkFileUsed(const base::FilePath& file_path,
 362                                               const base::Time& time) {
 363   base::TouchFile(file_path, time, time);
 364 }
 365
 366 // static
 367 void LocalExtensionCache::BackendInstallCacheEntry(
 368     base::WeakPtr<LocalExtensionCache> local_cache,
 369     const base::FilePath& cache_dir,
 370     const std::string& id,
 371     const base::FilePath& file_path,
 372     const std::string& version,
 373     const PutExtensionCallback& callback) {
 374   std::string basename = id + "-" + version + kCRXFileExtension;
 375   base::FilePath cached_crx_path = cache_dir.AppendASCII(basename);
 376
 377   bool was_error = false;
 378   if (base::PathExists(cached_crx_path)) {
 379     LOG(ERROR) << "File already exists " << file_path.value();
 380     cached_crx_path = file_path;
 381     was_error = true;
 382   }
 383
 384   base::File::Info info;
 385   if (!was_error) {
 386     if (!base::Move(file_path, cached_crx_path)) {
 387       LOG(ERROR) << "Failed to copy from " << file_path.value()
 388                  << " to " << cached_crx_path.value();
 389       cached_crx_path = file_path;
 390       was_error = true;
 391     } else {
 392       was_error = !base::GetFileInfo(cached_crx_path, &info);
 393       VLOG(1) << "Cache entry installed for extension id " << id
 394               << " version " << version;
 395     }
 396   }
 397
 398   content::BrowserThread::PostTask(
 399       content::BrowserThread::UI,
 400       FROM_HERE,
 401       base::Bind(&LocalExtensionCache::OnCacheEntryInstalled,
 402                  local_cache,
 403                  id,
 404                  CacheItemInfo(version, info.last_modified,
 405                                info.size, cached_crx_path),
 406                  was_error,
 407                  callback));
 408 }
 409
 410 void LocalExtensionCache::OnCacheEntryInstalled(
 411     const std::string& id,
 412     const CacheItemInfo& info,
 413     bool was_error,
 414     const PutExtensionCallback& callback) {
 415   if (state_ == kShutdown || was_error) {
 416     callback.Run(info.file_path, true);
 417     return;
 418   }
 419
 420   CacheMap::iterator it = cached_extensions_.find(id);
 421   if (it != cached_extensions_.end()) {
 422     Version new_version(info.version);
 423     Version prev_version(it->second.version);
 424     if (new_version.CompareTo(prev_version) <= 0) {
 425       DCHECK(0) << "Cache contains newer or the same version";
 426       callback.Run(info.file_path, true);
 427       return;
 428     }
 429     it->second = info;
 430   } else {
 431     it = cached_extensions_.insert(std::make_pair(id, info)).first;
 432   }
 433   // Time from file system can have lower precision so use precise "now".
 434   it->second.last_used = base::Time::Now();
 435
 436   callback.Run(info.file_path, false);
 437 }
 438
 439 // static
 440 void LocalExtensionCache::BackendRemoveCacheEntry(
 441     const base::FilePath& cache_dir,
 442     const std::string& id) {
 443   std::string file_pattern = id + "-*" + kCRXFileExtension;
 444   base::FileEnumerator enumerator(cache_dir,
 445                                   false /* not recursive */,
 446                                   base::FileEnumerator::FILES,
 447                                   file_pattern);
 448   for (base::FilePath path = enumerator.Next(); !path.empty();
 449        path = enumerator.Next()) {
 450     base::DeleteFile(path, false);
 451     VLOG(1) << "Removed cached file " << path.value();
 452   }
 453 }
 454
 455 // static
 456 bool LocalExtensionCache::CompareCacheItemsAge(const CacheMap::iterator& lhs,
 457                                                const CacheMap::iterator& rhs) {
 458   return lhs->second.last_used < rhs->second.last_used;
 459 }
 460
 461 void LocalExtensionCache::CleanUp() {
 462   DCHECK_EQ(state_, kReady);
 463
 464   std::vector<CacheMap::iterator> items;
 465   items.reserve(cached_extensions_.size());
 466   uint64_t total_size = 0;
 467   for (CacheMap::iterator it = cached_extensions_.begin();
 468        it != cached_extensions_.end(); ++it) {
 469     items.push_back(it);
 470     total_size += it->second.size;
 471   }
 472   std::sort(items.begin(), items.end(), CompareCacheItemsAge);
 473
 474   for (std::vector<CacheMap::iterator>::iterator it = items.begin();
 475        it != items.end(); ++it) {
 476     if ((*it)->second.last_used < min_cache_age_ ||
 477         (max_cache_size_ && total_size > max_cache_size_)) {
 478       total_size -= (*it)->second.size;
 479       VLOG(1) << "Clean up cached extension id " << (*it)->first;
 480       RemoveExtension((*it)->first);
 481     }
 482   }
 483 }
 484
 485 LocalExtensionCache::CacheItemInfo::CacheItemInfo(
 486     const std::string& version,
 487     const base::Time& last_used,
 488     uint64 size,
 489     const base::FilePath& file_path)
 490     : version(version), last_used(last_used), size(size), file_path(file_path) {
 491 }
 492
 493 }  // namespace extensions