chrome/browser/safe_browsing/database_manager.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/browser/safe_browsing/database_manager.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/bind_helpers.h"
  11 #include "base/callback.h"
  12 #include "base/command_line.h"
  13 #include "base/debug/leak_tracker.h"
  14 #include "base/metrics/histogram_macros.h"
  15 #include "base/profiler/scoped_tracker.h"
  16 #include "base/stl_util.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/threading/thread.h"
  19 #include "base/threading/thread_restrictions.h"
  20 #include "chrome/browser/browser_process.h"
  21 #include "chrome/browser/chrome_notification_types.h"
  22 #include "chrome/browser/prerender/prerender_field_trial.h"
  23 #include "chrome/browser/safe_browsing/client_side_detection_service.h"
  24 #include "chrome/browser/safe_browsing/download_protection_service.h"
  25 #include "chrome/browser/safe_browsing/malware_details.h"
  26 #include "chrome/browser/safe_browsing/protocol_manager.h"
  27 #include "chrome/browser/safe_browsing/safe_browsing_database.h"
  28 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
  29 #include "chrome/browser/safe_browsing/ui_manager.h"
  30 #include "chrome/common/chrome_constants.h"
  31 #include "chrome/common/chrome_paths.h"
  32 #include "chrome/common/chrome_switches.h"
  33 #include "components/startup_metric_utils/startup_metric_utils.h"
  34 #include "components/variations/variations_associated_data.h"
  35 #include "content/public/browser/browser_thread.h"
  36 #include "content/public/browser/notification_service.h"
  37 #include "url/url_constants.h"
  38
  39 using content::BrowserThread;
  40
  41 namespace {
  42
  43 // Timeout for match checks, e.g. download URLs, hashes.
  44 const int kCheckTimeoutMs = 10000;
  45
  46 // Records disposition information about the check.  |hit| should be
  47 // |true| if there were any prefix hits in |full_hashes|.
  48 void RecordGetHashCheckStatus(
  49     bool hit,
  50     safe_browsing_util::ListType check_type,
  51     const std::vector<SBFullHashResult>& full_hashes) {
  52   SafeBrowsingProtocolManager::ResultType result;
  53   if (full_hashes.empty()) {
  54     result = SafeBrowsingProtocolManager::GET_HASH_FULL_HASH_EMPTY;
  55   } else if (hit) {
  56     result = SafeBrowsingProtocolManager::GET_HASH_FULL_HASH_HIT;
  57   } else {
  58     result = SafeBrowsingProtocolManager::GET_HASH_FULL_HASH_MISS;
  59   }
  60   bool is_download = check_type == safe_browsing_util::BINURL;
  61   SafeBrowsingProtocolManager::RecordGetHashResult(is_download, result);
  62 }
  63
  64 bool IsExpectedThreat(
  65     const SBThreatType threat_type,
  66     const std::vector<SBThreatType>& expected_threats) {
  67   return expected_threats.end() != std::find(expected_threats.begin(),
  68                                              expected_threats.end(),
  69                                              threat_type);
  70 }
  71
  72 // Return the severest list id from the results in |full_hashes| which matches
  73 // |hash|, or INVALID if none match.
  74 safe_browsing_util::ListType GetHashSeverestThreatListType(
  75     const SBFullHash& hash,
  76     const std::vector<SBFullHashResult>& full_hashes,
  77     size_t* index) {
  78   safe_browsing_util::ListType pending_threat = safe_browsing_util::INVALID;
  79   for (size_t i = 0; i < full_hashes.size(); ++i) {
  80     if (SBFullHashEqual(hash, full_hashes[i].hash)) {
  81       const safe_browsing_util::ListType threat =
  82           static_cast<safe_browsing_util::ListType>(full_hashes[i].list_id);
  83       switch (threat) {
  84         case safe_browsing_util::INVALID:
  85           // |full_hashes| should never contain INVALID as a |list_id|.
  86           NOTREACHED();
  87           break;
  88         case safe_browsing_util::MALWARE:                  // Falls through.
  89         case safe_browsing_util::PHISH:                    // Falls through.
  90         case safe_browsing_util::BINURL:                   // Falls through.
  91         case safe_browsing_util::CSDWHITELIST:             // Falls through.
  92         case safe_browsing_util::DOWNLOADWHITELIST:        // Falls through.
  93         case safe_browsing_util::INCLUSIONWHITELIST:       // Falls through.
  94         case safe_browsing_util::EXTENSIONBLACKLIST:       // Falls through.
  95         case safe_browsing_util::SIDEEFFECTFREEWHITELIST:  // Falls through.
  96         case safe_browsing_util::IPBLACKLIST:
  97           if (index)
  98             *index = i;
  99           return threat;
 100         case safe_browsing_util::UNWANTEDURL:
 101           // UNWANTEDURL is considered less severe than other threats, keep
 102           // looking.
 103           pending_threat = threat;
 104           if (index)
 105             *index = i;
 106           break;
 107       }
 108     }
 109   }
 110   return pending_threat;
 111 }
 112
 113 // Given a URL, compare all the possible host + path full hashes to the set of
 114 // provided full hashes.  Returns the list id of the severest matching result
 115 // from |full_hashes|, or INVALID if none match.
 116 safe_browsing_util::ListType GetUrlSeverestThreatListType(
 117     const GURL& url,
 118     const std::vector<SBFullHashResult>& full_hashes,
 119     size_t* index) {
 120   if (full_hashes.empty())
 121     return safe_browsing_util::INVALID;
 122
 123   std::vector<std::string> patterns;
 124   safe_browsing_util::GeneratePatternsToCheck(url, &patterns);
 125
 126   safe_browsing_util::ListType pending_threat = safe_browsing_util::INVALID;
 127   for (size_t i = 0; i < patterns.size(); ++i) {
 128     safe_browsing_util::ListType threat = GetHashSeverestThreatListType(
 129         SBFullHashForString(patterns[i]), full_hashes, index);
 130     switch (threat) {
 131       case safe_browsing_util::INVALID:
 132         // Ignore patterns with no matching threat.
 133         break;
 134       case safe_browsing_util::MALWARE:                  // Falls through.
 135       case safe_browsing_util::PHISH:                    // Falls through.
 136       case safe_browsing_util::BINURL:                   // Falls through.
 137       case safe_browsing_util::CSDWHITELIST:             // Falls through.
 138       case safe_browsing_util::DOWNLOADWHITELIST:        // Falls through.
 139       case safe_browsing_util::INCLUSIONWHITELIST:       // Falls through.
 140       case safe_browsing_util::EXTENSIONBLACKLIST:       // Falls through.
 141       case safe_browsing_util::SIDEEFFECTFREEWHITELIST:  // Falls through.
 142       case safe_browsing_util::IPBLACKLIST:
 143         return threat;
 144       case safe_browsing_util::UNWANTEDURL:
 145         // UNWANTEDURL is considered less severe than other threats, keep
 146         // looking.
 147         pending_threat = threat;
 148         break;
 149     }
 150   }
 151   return pending_threat;
 152 }
 153
 154 SBThreatType GetThreatTypeFromListType(safe_browsing_util::ListType list_type) {
 155   switch (list_type) {
 156     case safe_browsing_util::PHISH:
 157       return SB_THREAT_TYPE_URL_PHISHING;
 158     case safe_browsing_util::MALWARE:
 159       return SB_THREAT_TYPE_URL_MALWARE;
 160     case safe_browsing_util::UNWANTEDURL:
 161       return SB_THREAT_TYPE_URL_UNWANTED;
 162     case safe_browsing_util::BINURL:
 163       return SB_THREAT_TYPE_BINARY_MALWARE_URL;
 164     case safe_browsing_util::EXTENSIONBLACKLIST:
 165       return SB_THREAT_TYPE_EXTENSION;
 166     default:
 167       DVLOG(1) << "Unknown safe browsing list id " << list_type;
 168       return SB_THREAT_TYPE_SAFE;
 169   }
 170 }
 171
 172 }  // namespace
 173
 174 // static
 175 SBThreatType SafeBrowsingDatabaseManager::GetHashSeverestThreatType(
 176     const SBFullHash& hash,
 177     const std::vector<SBFullHashResult>& full_hashes) {
 178   return GetThreatTypeFromListType(
 179       GetHashSeverestThreatListType(hash, full_hashes, NULL));
 180 }
 181
 182 // static
 183 SBThreatType SafeBrowsingDatabaseManager::GetUrlSeverestThreatType(
 184     const GURL& url,
 185     const std::vector<SBFullHashResult>& full_hashes,
 186     size_t* index) {
 187   return GetThreatTypeFromListType(
 188       GetUrlSeverestThreatListType(url, full_hashes, index));
 189 }
 190
 191 SafeBrowsingDatabaseManager::SafeBrowsingCheck::SafeBrowsingCheck(
 192     const std::vector<GURL>& urls,
 193     const std::vector<SBFullHash>& full_hashes,
 194     Client* client,
 195     safe_browsing_util::ListType check_type,
 196     const std::vector<SBThreatType>& expected_threats)
 197     : urls(urls),
 198       url_results(urls.size(), SB_THREAT_TYPE_SAFE),
 199       url_metadata(urls.size()),
 200       full_hashes(full_hashes),
 201       full_hash_results(full_hashes.size(), SB_THREAT_TYPE_SAFE),
 202       client(client),
 203       need_get_hash(false),
 204       check_type(check_type),
 205       expected_threats(expected_threats) {
 206   DCHECK_EQ(urls.empty(), !full_hashes.empty())
 207       << "Exactly one of urls and full_hashes must be set";
 208 }
 209
 210 SafeBrowsingDatabaseManager::SafeBrowsingCheck::~SafeBrowsingCheck() {}
 211
 212 void SafeBrowsingDatabaseManager::Client::OnSafeBrowsingResult(
 213     const SafeBrowsingCheck& check) {
 214   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 215
 216   DCHECK_EQ(check.urls.size(), check.url_results.size());
 217   DCHECK_EQ(check.full_hashes.size(), check.full_hash_results.size());
 218   if (!check.urls.empty()) {
 219     DCHECK(check.full_hashes.empty());
 220     switch (check.check_type) {
 221       case safe_browsing_util::MALWARE:
 222       case safe_browsing_util::PHISH:
 223       case safe_browsing_util::UNWANTEDURL:
 224         DCHECK_EQ(1u, check.urls.size());
 225         OnCheckBrowseUrlResult(
 226             check.urls[0], check.url_results[0], check.url_metadata[0]);
 227         break;
 228       case safe_browsing_util::BINURL:
 229         DCHECK_EQ(check.urls.size(), check.url_results.size());
 230         OnCheckDownloadUrlResult(
 231             check.urls,
 232             *std::max_element(check.url_results.begin(),
 233                               check.url_results.end()));
 234         break;
 235       default:
 236         NOTREACHED();
 237     }
 238   } else if (!check.full_hashes.empty()) {
 239     switch (check.check_type) {
 240       case safe_browsing_util::EXTENSIONBLACKLIST: {
 241         std::set<std::string> unsafe_extension_ids;
 242         for (size_t i = 0; i < check.full_hashes.size(); ++i) {
 243           std::string extension_id =
 244               safe_browsing_util::SBFullHashToString(check.full_hashes[i]);
 245           if (check.full_hash_results[i] == SB_THREAT_TYPE_EXTENSION)
 246             unsafe_extension_ids.insert(extension_id);
 247         }
 248         OnCheckExtensionsResult(unsafe_extension_ids);
 249         break;
 250       }
 251       default:
 252         NOTREACHED();
 253     }
 254   } else {
 255     NOTREACHED();
 256   }
 257 }
 258
 259 SafeBrowsingDatabaseManager::SafeBrowsingDatabaseManager(
 260     const scoped_refptr<SafeBrowsingService>& service)
 261     : sb_service_(service),
 262       database_(NULL),
 263       enabled_(false),
 264       enable_download_protection_(false),
 265       enable_csd_whitelist_(false),
 266       enable_download_whitelist_(false),
 267       enable_extension_blacklist_(false),
 268       enable_side_effect_free_whitelist_(false),
 269       enable_ip_blacklist_(false),
 270       enable_unwanted_software_blacklist_(false),
 271       update_in_progress_(false),
 272       database_update_in_progress_(false),
 273       closing_database_(false),
 274       check_timeout_(base::TimeDelta::FromMilliseconds(kCheckTimeoutMs)) {
 275   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 276   DCHECK(sb_service_.get() != NULL);
 277
 278   // Android only supports a subset of FULL_SAFE_BROWSING.
 279   // TODO(shess): This shouldn't be OS-driven <http://crbug.com/394379>
 280 #if !defined(OS_ANDROID)
 281   base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
 282   enable_download_protection_ =
 283       !cmdline->HasSwitch(switches::kSbDisableDownloadProtection);
 284
 285   // We only download the csd-whitelist if client-side phishing detection is
 286   // enabled.
 287   enable_csd_whitelist_ =
 288       !cmdline->HasSwitch(switches::kDisableClientSidePhishingDetection);
 289
 290   // TODO(noelutz): remove this boolean variable since it should always be true
 291   // if SafeBrowsing is enabled.  Unfortunately, we have no test data for this
 292   // list right now.  This means that we need to be able to disable this list
 293   // for the SafeBrowsing test to pass.
 294   enable_download_whitelist_ = enable_csd_whitelist_;
 295
 296   // TODO(kalman): there really shouldn't be a flag for this.
 297   enable_extension_blacklist_ =
 298       !cmdline->HasSwitch(switches::kSbDisableExtensionBlacklist);
 299
 300   enable_side_effect_free_whitelist_ =
 301       prerender::IsSideEffectFreeWhitelistEnabled() &&
 302       !cmdline->HasSwitch(switches::kSbDisableSideEffectFreeWhitelist);
 303
 304   // The client-side IP blacklist feature is tightly integrated with client-side
 305   // phishing protection for now.
 306   enable_ip_blacklist_ = enable_csd_whitelist_;
 307
 308   // The UwS blacklist feature is controlled by a flag for M40.
 309   enable_unwanted_software_blacklist_ =
 310       safe_browsing_util::GetUnwantedTrialGroup() > safe_browsing_util::UWS_OFF;
 311
 312   enum SideEffectFreeWhitelistStatus {
 313     SIDE_EFFECT_FREE_WHITELIST_ENABLED,
 314     SIDE_EFFECT_FREE_WHITELIST_DISABLED,
 315     SIDE_EFFECT_FREE_WHITELIST_STATUS_MAX
 316   };
 317
 318   SideEffectFreeWhitelistStatus side_effect_free_whitelist_status =
 319       enable_side_effect_free_whitelist_ ? SIDE_EFFECT_FREE_WHITELIST_ENABLED :
 320       SIDE_EFFECT_FREE_WHITELIST_DISABLED;
 321
 322   UMA_HISTOGRAM_ENUMERATION("SB2.SideEffectFreeWhitelistStatus",
 323                             side_effect_free_whitelist_status,
 324                             SIDE_EFFECT_FREE_WHITELIST_STATUS_MAX);
 325 #endif
 326 }
 327
 328 SafeBrowsingDatabaseManager::~SafeBrowsingDatabaseManager() {
 329   // The DCHECK is disabled due to crbug.com/438754.
 330   // DCHECK_CURRENTLY_ON(BrowserThread::UI);
 331
 332   // We should have already been shut down. If we're still enabled, then the
 333   // database isn't going to be closed properly, which could lead to corruption.
 334   DCHECK(!enabled_);
 335 }
 336
 337 bool SafeBrowsingDatabaseManager::CanCheckUrl(const GURL& url) const {
 338   return url.SchemeIs(url::kFtpScheme) ||
 339          url.SchemeIs(url::kHttpScheme) ||
 340          url.SchemeIs(url::kHttpsScheme);
 341 }
 342
 343 bool SafeBrowsingDatabaseManager::CheckDownloadUrl(
 344     const std::vector<GURL>& url_chain,
 345     Client* client) {
 346   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 347   if (!enabled_ || !enable_download_protection_)
 348     return true;
 349
 350   // We need to check the database for url prefix, and later may fetch the url
 351   // from the safebrowsing backends. These need to be asynchronous.
 352   SafeBrowsingCheck* check =
 353       new SafeBrowsingCheck(url_chain,
 354                             std::vector<SBFullHash>(),
 355                             client,
 356                             safe_browsing_util::BINURL,
 357                             std::vector<SBThreatType>(1,
 358                                 SB_THREAT_TYPE_BINARY_MALWARE_URL));
 359   StartSafeBrowsingCheck(
 360       check,
 361       base::Bind(&SafeBrowsingDatabaseManager::CheckDownloadUrlOnSBThread, this,
 362                  check));
 363   return false;
 364 }
 365
 366 bool SafeBrowsingDatabaseManager::CheckExtensionIDs(
 367     const std::set<std::string>& extension_ids,
 368     Client* client) {
 369   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 370
 371   if (!enabled_ || !enable_extension_blacklist_)
 372     return true;
 373
 374   std::vector<SBFullHash> extension_id_hashes;
 375   std::transform(extension_ids.begin(), extension_ids.end(),
 376                  std::back_inserter(extension_id_hashes),
 377                  safe_browsing_util::StringToSBFullHash);
 378
 379   SafeBrowsingCheck* check = new SafeBrowsingCheck(
 380       std::vector<GURL>(),
 381       extension_id_hashes,
 382       client,
 383       safe_browsing_util::EXTENSIONBLACKLIST,
 384       std::vector<SBThreatType>(1, SB_THREAT_TYPE_EXTENSION));
 385
 386   StartSafeBrowsingCheck(
 387       check,
 388       base::Bind(&SafeBrowsingDatabaseManager::CheckExtensionIDsOnSBThread,
 389                  this,
 390                  check));
 391   return false;
 392 }
 393
 394 bool SafeBrowsingDatabaseManager::CheckSideEffectFreeWhitelistUrl(
 395     const GURL& url) {
 396   if (!enabled_)
 397     return false;
 398
 399   if (!CanCheckUrl(url))
 400     return false;
 401
 402   return database_->ContainsSideEffectFreeWhitelistUrl(url);
 403 }
 404
 405 bool SafeBrowsingDatabaseManager::MatchMalwareIP(
 406     const std::string& ip_address) {
 407   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 408   if (!enabled_ || !enable_ip_blacklist_ || !MakeDatabaseAvailable()) {
 409     return false;  // Fail open.
 410   }
 411   return database_->ContainsMalwareIP(ip_address);
 412 }
 413
 414 bool SafeBrowsingDatabaseManager::MatchCsdWhitelistUrl(const GURL& url) {
 415   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 416   if (!enabled_ || !enable_csd_whitelist_ || !MakeDatabaseAvailable()) {
 417     // There is something funky going on here -- for example, perhaps the user
 418     // has not restarted since enabling metrics reporting, so we haven't
 419     // enabled the csd whitelist yet.  Just to be safe we return true in this
 420     // case.
 421     return true;
 422   }
 423   return database_->ContainsCsdWhitelistedUrl(url);
 424 }
 425
 426 bool SafeBrowsingDatabaseManager::MatchDownloadWhitelistUrl(const GURL& url) {
 427   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 428   if (!enabled_ || !enable_download_whitelist_ || !MakeDatabaseAvailable()) {
 429     return true;
 430   }
 431   return database_->ContainsDownloadWhitelistedUrl(url);
 432 }
 433
 434 bool SafeBrowsingDatabaseManager::MatchDownloadWhitelistString(
 435     const std::string& str) {
 436   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 437   if (!enabled_ || !enable_download_whitelist_ || !MakeDatabaseAvailable()) {
 438     return true;
 439   }
 440   return database_->ContainsDownloadWhitelistedString(str);
 441 }
 442
 443 bool SafeBrowsingDatabaseManager::MatchInclusionWhitelistUrl(const GURL& url) {
 444   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 445   if (!enabled_ || !MakeDatabaseAvailable())
 446     return true;
 447   return database_->ContainsInclusionWhitelistedUrl(url);
 448 }
 449
 450 bool SafeBrowsingDatabaseManager::IsMalwareKillSwitchOn() {
 451   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 452   if (!enabled_ || !MakeDatabaseAvailable()) {
 453     return true;
 454   }
 455   return database_->IsMalwareIPMatchKillSwitchOn();
 456 }
 457
 458 bool SafeBrowsingDatabaseManager::IsCsdWhitelistKillSwitchOn() {
 459   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 460   if (!enabled_ || !MakeDatabaseAvailable()) {
 461     return true;
 462   }
 463   return database_->IsCsdWhitelistKillSwitchOn();
 464 }
 465
 466 bool SafeBrowsingDatabaseManager::CheckBrowseUrl(const GURL& url,
 467                                                  Client* client) {
 468   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 469   if (!enabled_)
 470     return true;
 471
 472   if (!CanCheckUrl(url))
 473     return true;
 474
 475   std::vector<SBThreatType> expected_threats;
 476   expected_threats.push_back(SB_THREAT_TYPE_URL_MALWARE);
 477   expected_threats.push_back(SB_THREAT_TYPE_URL_PHISHING);
 478   expected_threats.push_back(SB_THREAT_TYPE_URL_UNWANTED);
 479
 480   const base::TimeTicks start = base::TimeTicks::Now();
 481   if (!MakeDatabaseAvailable()) {
 482     QueuedCheck queued_check(safe_browsing_util::MALWARE,  // or PHISH
 483                              client,
 484                              url,
 485                              expected_threats,
 486                              start);
 487     queued_checks_.push_back(queued_check);
 488     return false;
 489   }
 490
 491   // Cache hits should, in general, be the same for both (ignoring potential
 492   // cache evictions in the second call for entries that were just about to be
 493   // evicted in the first call).
 494   // TODO(gab): Refactor SafeBrowsingDatabase to avoid depending on this here.
 495   std::vector<SBFullHashResult> cache_hits;
 496
 497   std::vector<SBPrefix> browse_prefix_hits;
 498   bool browse_prefix_match = database_->ContainsBrowseUrl(
 499       url, &browse_prefix_hits, &cache_hits);
 500
 501   std::vector<SBPrefix> unwanted_prefix_hits;
 502   std::vector<SBFullHashResult> unused_cache_hits;
 503   bool unwanted_prefix_match = database_->ContainsUnwantedSoftwareUrl(
 504       url, &unwanted_prefix_hits, &unused_cache_hits);
 505
 506   // Merge the two pre-sorted prefix hits lists.
 507   // TODO(gab): Refactor SafeBrowsingDatabase for it to return this merged list
 508   // by default rather than building it here.
 509   std::vector<SBPrefix> prefix_hits(browse_prefix_hits.size() +
 510                                     unwanted_prefix_hits.size());
 511   std::merge(browse_prefix_hits.begin(),
 512              browse_prefix_hits.end(),
 513              unwanted_prefix_hits.begin(),
 514              unwanted_prefix_hits.end(),
 515              prefix_hits.begin());
 516   prefix_hits.erase(std::unique(prefix_hits.begin(), prefix_hits.end()),
 517                     prefix_hits.end());
 518
 519   UMA_HISTOGRAM_TIMES("SB2.FilterCheck", base::TimeTicks::Now() - start);
 520
 521   if (!browse_prefix_match && !unwanted_prefix_match)
 522     return true;  // URL is okay.
 523
 524   // Needs to be asynchronous, since we could be in the constructor of a
 525   // ResourceDispatcherHost event handler which can't pause there.
 526   // This check will ping the Safe Browsing servers and get all lists which it
 527   // matches. These lists will then be filtered against the |expected_threats|
 528   // and the result callback for MALWARE (which is the same as for PHISH and
 529   // UNWANTEDURL) will eventually be invoked with the final decision.
 530   SafeBrowsingCheck* check = new SafeBrowsingCheck(std::vector<GURL>(1, url),
 531                                                    std::vector<SBFullHash>(),
 532                                                    client,
 533                                                    safe_browsing_util::MALWARE,
 534                                                    expected_threats);
 535   check->need_get_hash = cache_hits.empty();
 536   check->prefix_hits.swap(prefix_hits);
 537   check->cache_hits.swap(cache_hits);
 538   checks_.insert(check);
 539
 540   BrowserThread::PostTask(
 541       BrowserThread::IO, FROM_HERE,
 542       base::Bind(&SafeBrowsingDatabaseManager::OnCheckDone, this, check));
 543
 544   return false;
 545 }
 546
 547 void SafeBrowsingDatabaseManager::CancelCheck(Client* client) {
 548   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 549   for (CurrentChecks::iterator i = checks_.begin(); i != checks_.end(); ++i) {
 550     // We can't delete matching checks here because the db thread has a copy of
 551     // the pointer.  Instead, we simply NULL out the client, and when the db
 552     // thread calls us back, we'll clean up the check.
 553     if ((*i)->client == client)
 554       (*i)->client = NULL;
 555   }
 556
 557   // Scan the queued clients store. Clients may be here if they requested a URL
 558   // check before the database has finished loading.
 559   for (std::deque<QueuedCheck>::iterator it(queued_checks_.begin());
 560        it != queued_checks_.end(); ) {
 561     // In this case it's safe to delete matches entirely since nothing has a
 562     // pointer to them.
 563     if (it->client == client)
 564       it = queued_checks_.erase(it);
 565     else
 566       ++it;
 567   }
 568 }
 569
 570 void SafeBrowsingDatabaseManager::HandleGetHashResults(
 571     SafeBrowsingCheck* check,
 572     const std::vector<SBFullHashResult>& full_hashes,
 573     const base::TimeDelta& cache_lifetime) {
 574   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 575
 576   if (!enabled_)
 577     return;
 578
 579   // If the service has been shut down, |check| should have been deleted.
 580   DCHECK(checks_.find(check) != checks_.end());
 581
 582   // |start| is set before calling |GetFullHash()|, which should be
 583   // the only path which gets to here.
 584   DCHECK(!check->start.is_null());
 585   UMA_HISTOGRAM_LONG_TIMES("SB2.Network",
 586                            base::TimeTicks::Now() - check->start);
 587
 588   std::vector<SBPrefix> prefixes = check->prefix_hits;
 589   OnHandleGetHashResults(check, full_hashes);  // 'check' is deleted here.
 590
 591   // Cache the GetHash results.
 592   if (cache_lifetime != base::TimeDelta() && MakeDatabaseAvailable())
 593     database_->CacheHashResults(prefixes, full_hashes, cache_lifetime);
 594 }
 595
 596 void SafeBrowsingDatabaseManager::GetChunks(GetChunksCallback callback) {
 597   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 598   DCHECK(enabled_);
 599   DCHECK(!callback.is_null());
 600   safe_browsing_task_runner_->PostTask(
 601       FROM_HERE,
 602       base::Bind(&SafeBrowsingDatabaseManager::GetAllChunksFromDatabase, this,
 603                  callback));
 604 }
 605
 606 void SafeBrowsingDatabaseManager::AddChunks(
 607     const std::string& list,
 608     scoped_ptr<ScopedVector<SBChunkData> > chunks,
 609     AddChunksCallback callback) {
 610   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 611   DCHECK(enabled_);
 612   DCHECK(!callback.is_null());
 613   safe_browsing_task_runner_->PostTask(
 614       FROM_HERE, base::Bind(&SafeBrowsingDatabaseManager::AddDatabaseChunks,
 615                             this, list, base::Passed(&chunks), callback));
 616 }
 617
 618 void SafeBrowsingDatabaseManager::DeleteChunks(
 619     scoped_ptr<std::vector<SBChunkDelete> > chunk_deletes) {
 620   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 621   DCHECK(enabled_);
 622   safe_browsing_task_runner_->PostTask(
 623       FROM_HERE, base::Bind(&SafeBrowsingDatabaseManager::DeleteDatabaseChunks,
 624                             this, base::Passed(&chunk_deletes)));
 625 }
 626
 627 void SafeBrowsingDatabaseManager::UpdateStarted() {
 628   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 629   DCHECK(enabled_);
 630   DCHECK(!update_in_progress_);
 631   update_in_progress_ = true;
 632 }
 633
 634 void SafeBrowsingDatabaseManager::UpdateFinished(bool update_succeeded) {
 635   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 636   DCHECK(enabled_);
 637   if (update_in_progress_) {
 638     update_in_progress_ = false;
 639     safe_browsing_task_runner_->PostTask(
 640         FROM_HERE,
 641         base::Bind(&SafeBrowsingDatabaseManager::DatabaseUpdateFinished, this,
 642                    update_succeeded));
 643   }
 644 }
 645
 646 void SafeBrowsingDatabaseManager::ResetDatabase() {
 647   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 648   DCHECK(enabled_);
 649   safe_browsing_task_runner_->PostTask(
 650       FROM_HERE,
 651       base::Bind(&SafeBrowsingDatabaseManager::OnResetDatabase, this));
 652 }
 653
 654 void SafeBrowsingDatabaseManager::StartOnIOThread() {
 655   // TODO(pkasting): Remove ScopedTracker below once crbug.com/455469 is fixed.
 656   tracked_objects::ScopedTracker tracking_profile1(
 657       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 658           "455469 SafeBrowsingDatabaseManager::StartOnIOThread1"));
 659   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 660   if (enabled_)
 661     return;
 662
 663   DCHECK(!safe_browsing_task_runner_);
 664   // Use the blocking pool instead of a dedicated thread for safe browsing work,
 665   // if specified by an experiment.
 666   const bool use_blocking_pool =
 667       variations::GetVariationParamValue("LightSpeed", "SBThreadingMode") ==
 668       "BlockingPool";
 669   if (use_blocking_pool) {
 670     // TODO(pkasting): Remove ScopedTracker below once crbug.com/455469 is
 671     // fixed.
 672     tracked_objects::ScopedTracker tracking_profile2(
 673         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 674             "455469 SafeBrowsingDatabaseManager::StartOnIOThread2"));
 675     base::SequencedWorkerPool* pool = BrowserThread::GetBlockingPool();
 676     safe_browsing_task_runner_ =
 677         pool->GetSequencedTaskRunnerWithShutdownBehavior(
 678             pool->GetSequenceToken(),
 679             base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
 680   } else {
 681     // TODO(pkasting): Remove ScopedTracker below once crbug.com/455469 is
 682     // fixed.
 683     tracked_objects::ScopedTracker tracking_profile3(
 684         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 685             "455469 SafeBrowsingDatabaseManager::StartOnIOThread3"));
 686     DCHECK(!safe_browsing_thread_.get());
 687
 688     safe_browsing_thread_.reset(new base::Thread("Chrome_SafeBrowsingThread"));
 689     if (!safe_browsing_thread_->Start())
 690       return;
 691     safe_browsing_task_runner_ = safe_browsing_thread_->task_runner();
 692   }
 693
 694   enabled_ = true;
 695
 696   MakeDatabaseAvailable();
 697 }
 698
 699 void SafeBrowsingDatabaseManager::StopOnIOThread(bool shutdown) {
 700   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 701
 702   DoStopOnIOThread();
 703   if (shutdown) {
 704     sb_service_ = NULL;
 705   }
 706 }
 707
 708 void SafeBrowsingDatabaseManager::NotifyDatabaseUpdateFinished(
 709     bool update_succeeded) {
 710   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 711   content::NotificationService::current()->Notify(
 712       chrome::NOTIFICATION_SAFE_BROWSING_UPDATE_COMPLETE,
 713       content::Source<SafeBrowsingDatabaseManager>(this),
 714       content::Details<bool>(&update_succeeded));
 715 }
 716
 717 SafeBrowsingDatabaseManager::QueuedCheck::QueuedCheck(
 718     const safe_browsing_util::ListType check_type,
 719     Client* client,
 720     const GURL& url,
 721     const std::vector<SBThreatType>& expected_threats,
 722     const base::TimeTicks& start)
 723     : check_type(check_type),
 724       client(client),
 725       url(url),
 726       expected_threats(expected_threats),
 727       start(start) {
 728 }
 729
 730 SafeBrowsingDatabaseManager::QueuedCheck::~QueuedCheck() {
 731 }
 732
 733 void SafeBrowsingDatabaseManager::DoStopOnIOThread() {
 734   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 735
 736   if (!enabled_)
 737     return;
 738
 739   enabled_ = false;
 740
 741   // Delete queued checks, calling back any clients with 'SB_THREAT_TYPE_SAFE'.
 742   while (!queued_checks_.empty()) {
 743     QueuedCheck queued = queued_checks_.front();
 744     if (queued.client) {
 745       SafeBrowsingCheck sb_check(std::vector<GURL>(1, queued.url),
 746                                  std::vector<SBFullHash>(),
 747                                  queued.client,
 748                                  queued.check_type,
 749                                  queued.expected_threats);
 750       queued.client->OnSafeBrowsingResult(sb_check);
 751     }
 752     queued_checks_.pop_front();
 753   }
 754
 755   // Close the database.  Cases to avoid:
 756   //  * If |closing_database_| is true, continuing will queue up a second
 757   //    request, |closing_database_| will be reset after handling the first
 758   //    request, and if any functions on the db thread recreate the database, we
 759   //    could start using it on the IO thread and then have the second request
 760   //    handler delete it out from under us.
 761   //  * If |database_| is NULL, then either no creation request is in flight, in
 762   //    which case we don't need to do anything, or one is in flight, in which
 763   //    case the database will be recreated before our deletion request is
 764   //    handled, and could be used on the IO thread in that time period, leading
 765   //    to the same problem as above.
 766   // Checking DatabaseAvailable() avoids both of these.
 767   if (DatabaseAvailable()) {
 768     closing_database_ = true;
 769     safe_browsing_task_runner_->PostTask(
 770         FROM_HERE,
 771         base::Bind(&SafeBrowsingDatabaseManager::OnCloseDatabase, this));
 772   }
 773
 774   // Flush the database thread. Any in-progress database check results will be
 775   // ignored and cleaned up below.
 776   //
 777   // Note that to avoid leaking the database, we rely on the fact that no new
 778   // tasks will be added to the db thread between the call above and this one.
 779   // See comments on the declaration of |safe_browsing_thread_|.
 780   if (safe_browsing_thread_) {
 781     // A ScopedAllowIO object is required to join the thread when calling Stop.
 782     // See http://crbug.com/72696. Note that we call Stop() first to clear out
 783     // any remaining tasks before clearing safe_browsing_thread_.
 784     base::ThreadRestrictions::ScopedAllowIO allow_io_for_thread_join;
 785     safe_browsing_thread_->Stop();
 786     safe_browsing_thread_.reset();
 787   }
 788   safe_browsing_task_runner_ = nullptr;
 789
 790   // Delete pending checks, calling back any clients with 'SB_THREAT_TYPE_SAFE'.
 791   // We have to do this after the db thread returns because methods on it can
 792   // have copies of these pointers, so deleting them might lead to accessing
 793   // garbage.
 794   for (CurrentChecks::iterator it = checks_.begin();
 795        it != checks_.end(); ++it) {
 796     SafeBrowsingCheck* check = *it;
 797     if (check->client)
 798       check->client->OnSafeBrowsingResult(*check);
 799   }
 800   STLDeleteElements(&checks_);
 801
 802   gethash_requests_.clear();
 803 }
 804
 805 bool SafeBrowsingDatabaseManager::DatabaseAvailable() const {
 806   base::AutoLock lock(database_lock_);
 807   return !closing_database_ && (database_ != NULL);
 808 }
 809
 810 bool SafeBrowsingDatabaseManager::MakeDatabaseAvailable() {
 811   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 812   DCHECK(enabled_);
 813   if (DatabaseAvailable())
 814     return true;
 815   safe_browsing_task_runner_->PostTask(
 816       FROM_HERE,
 817       base::Bind(base::IgnoreResult(&SafeBrowsingDatabaseManager::GetDatabase),
 818                  this));
 819   return false;
 820 }
 821
 822 SafeBrowsingDatabase* SafeBrowsingDatabaseManager::GetDatabase() {
 823   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
 824
 825   if (database_)
 826     return database_;
 827   startup_metric_utils::ScopedSlowStartupUMA
 828       scoped_timer("Startup.SlowStartupSafeBrowsingGetDatabase");
 829   const base::TimeTicks before = base::TimeTicks::Now();
 830
 831   SafeBrowsingDatabase* database = SafeBrowsingDatabase::Create(
 832       safe_browsing_task_runner_, enable_download_protection_,
 833       enable_csd_whitelist_, enable_download_whitelist_,
 834       enable_extension_blacklist_, enable_side_effect_free_whitelist_,
 835       enable_ip_blacklist_, enable_unwanted_software_blacklist_);
 836
 837   database->Init(SafeBrowsingService::GetBaseFilename());
 838   {
 839     // Acquiring the lock here guarantees correct ordering between the writes to
 840     // the new database object above, and the setting of |database_| below.
 841     base::AutoLock lock(database_lock_);
 842     database_ = database;
 843   }
 844
 845   BrowserThread::PostTask(
 846       BrowserThread::IO, FROM_HERE,
 847       base::Bind(&SafeBrowsingDatabaseManager::DatabaseLoadComplete, this));
 848
 849   UMA_HISTOGRAM_TIMES("SB2.DatabaseOpen", base::TimeTicks::Now() - before);
 850   return database_;
 851 }
 852
 853 void SafeBrowsingDatabaseManager::OnCheckDone(SafeBrowsingCheck* check) {
 854   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 855
 856   if (!enabled_)
 857     return;
 858
 859   // If the service has been shut down, |check| should have been deleted.
 860   DCHECK(checks_.find(check) != checks_.end());
 861
 862   if (check->client && check->need_get_hash) {
 863     // We have a partial match so we need to query Google for the full hash.
 864     // Clean up will happen in HandleGetHashResults.
 865
 866     // See if we have a GetHash request already in progress for this particular
 867     // prefix. If so, we just append ourselves to the list of interested parties
 868     // when the results arrive. We only do this for checks involving one prefix,
 869     // since that is the common case (multiple prefixes will issue the request
 870     // as normal).
 871     if (check->prefix_hits.size() == 1) {
 872       SBPrefix prefix = check->prefix_hits[0];
 873       GetHashRequests::iterator it = gethash_requests_.find(prefix);
 874       if (it != gethash_requests_.end()) {
 875         // There's already a request in progress.
 876         it->second.push_back(check);
 877         return;
 878       }
 879
 880       // No request in progress, so we're the first for this prefix.
 881       GetHashRequestors requestors;
 882       requestors.push_back(check);
 883       gethash_requests_[prefix] = requestors;
 884     }
 885
 886     // Reset the start time so that we can measure the network time without the
 887     // database time.
 888     check->start = base::TimeTicks::Now();
 889     // Note: If |this| is deleted or stopped, the protocol_manager will
 890     // be destroyed as well - hence it's OK to do unretained in this case.
 891     bool is_download = check->check_type == safe_browsing_util::BINURL;
 892     sb_service_->protocol_manager()->GetFullHash(
 893         check->prefix_hits,
 894         base::Bind(&SafeBrowsingDatabaseManager::HandleGetHashResults,
 895                    base::Unretained(this),
 896                    check),
 897         is_download);
 898   } else {
 899     // We may have cached results for previous GetHash queries.  Since
 900     // this data comes from cache, don't histogram hits.
 901     HandleOneCheck(check, check->cache_hits);
 902   }
 903 }
 904
 905 void SafeBrowsingDatabaseManager::GetAllChunksFromDatabase(
 906     GetChunksCallback callback) {
 907   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
 908
 909   bool database_error = true;
 910   std::vector<SBListChunkRanges> lists;
 911   DCHECK(!database_update_in_progress_);
 912   database_update_in_progress_ = true;
 913   GetDatabase();  // This guarantees that |database_| is non-NULL.
 914   if (database_->UpdateStarted(&lists)) {
 915     database_error = false;
 916   } else {
 917     database_->UpdateFinished(false);
 918   }
 919
 920   BrowserThread::PostTask(
 921       BrowserThread::IO, FROM_HERE,
 922       base::Bind(&SafeBrowsingDatabaseManager::OnGetAllChunksFromDatabase,
 923                  this, lists, database_error, callback));
 924 }
 925
 926 void SafeBrowsingDatabaseManager::OnGetAllChunksFromDatabase(
 927     const std::vector<SBListChunkRanges>& lists, bool database_error,
 928     GetChunksCallback callback) {
 929   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 930   if (enabled_)
 931     callback.Run(lists, database_error);
 932 }
 933
 934 void SafeBrowsingDatabaseManager::OnAddChunksComplete(
 935     AddChunksCallback callback) {
 936   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 937   if (enabled_)
 938     callback.Run();
 939 }
 940
 941 void SafeBrowsingDatabaseManager::DatabaseLoadComplete() {
 942   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 943   if (!enabled_)
 944     return;
 945
 946   LOCAL_HISTOGRAM_COUNTS("SB.QueueDepth", queued_checks_.size());
 947   if (queued_checks_.empty())
 948     return;
 949
 950   // If the database isn't already available, calling CheckUrl() in the loop
 951   // below will add the check back to the queue, and we'll infinite-loop.
 952   DCHECK(DatabaseAvailable());
 953   while (!queued_checks_.empty()) {
 954     QueuedCheck check = queued_checks_.front();
 955     DCHECK(!check.start.is_null());
 956     LOCAL_HISTOGRAM_TIMES("SB.QueueDelay",
 957                           base::TimeTicks::Now() - check.start);
 958     // If CheckUrl() determines the URL is safe immediately, it doesn't call the
 959     // client's handler function (because normally it's being directly called by
 960     // the client).  Since we're not the client, we have to convey this result.
 961     if (check.client && CheckBrowseUrl(check.url, check.client)) {
 962       SafeBrowsingCheck sb_check(std::vector<GURL>(1, check.url),
 963                                  std::vector<SBFullHash>(),
 964                                  check.client,
 965                                  check.check_type,
 966                                  check.expected_threats);
 967       check.client->OnSafeBrowsingResult(sb_check);
 968     }
 969     queued_checks_.pop_front();
 970   }
 971 }
 972
 973 void SafeBrowsingDatabaseManager::AddDatabaseChunks(
 974     const std::string& list_name,
 975     scoped_ptr<ScopedVector<SBChunkData> > chunks,
 976     AddChunksCallback callback) {
 977   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
 978   if (chunks)
 979     GetDatabase()->InsertChunks(list_name, chunks->get());
 980   BrowserThread::PostTask(
 981       BrowserThread::IO, FROM_HERE,
 982       base::Bind(&SafeBrowsingDatabaseManager::OnAddChunksComplete, this,
 983                  callback));
 984 }
 985
 986 void SafeBrowsingDatabaseManager::DeleteDatabaseChunks(
 987     scoped_ptr<std::vector<SBChunkDelete> > chunk_deletes) {
 988   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
 989   if (chunk_deletes)
 990     GetDatabase()->DeleteChunks(*chunk_deletes);
 991 }
 992
 993 void SafeBrowsingDatabaseManager::DatabaseUpdateFinished(
 994     bool update_succeeded) {
 995   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
 996   GetDatabase()->UpdateFinished(update_succeeded);
 997   DCHECK(database_update_in_progress_);
 998   database_update_in_progress_ = false;
 999   BrowserThread::PostTask(
1000       BrowserThread::UI, FROM_HERE,
1001       base::Bind(&SafeBrowsingDatabaseManager::NotifyDatabaseUpdateFinished,
1002                  this, update_succeeded));
1003 }
1004
1005 void SafeBrowsingDatabaseManager::OnCloseDatabase() {
1006   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
1007   DCHECK(closing_database_);
1008
1009   // Because |closing_database_| is true, nothing on the IO thread will be
1010   // accessing the database, so it's safe to delete and then NULL the pointer.
1011   delete database_;
1012   database_ = NULL;
1013
1014   // Acquiring the lock here guarantees correct ordering between the resetting
1015   // of |database_| above and of |closing_database_| below, which ensures there
1016   // won't be a window during which the IO thread falsely believes the database
1017   // is available.
1018   base::AutoLock lock(database_lock_);
1019   closing_database_ = false;
1020 }
1021
1022 void SafeBrowsingDatabaseManager::OnResetDatabase() {
1023   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
1024
1025   GetDatabase()->ResetDatabase();
1026 }
1027
1028 void SafeBrowsingDatabaseManager::OnHandleGetHashResults(
1029     SafeBrowsingCheck* check,
1030     const std::vector<SBFullHashResult>& full_hashes) {
1031   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1032   safe_browsing_util::ListType check_type = check->check_type;
1033   SBPrefix prefix = check->prefix_hits[0];
1034   GetHashRequests::iterator it = gethash_requests_.find(prefix);
1035   if (check->prefix_hits.size() > 1 || it == gethash_requests_.end()) {
1036     const bool hit = HandleOneCheck(check, full_hashes);
1037     RecordGetHashCheckStatus(hit, check_type, full_hashes);
1038     return;
1039   }
1040
1041   // Call back all interested parties, noting if any has a hit.
1042   GetHashRequestors& requestors = it->second;
1043   bool hit = false;
1044   for (GetHashRequestors::iterator r = requestors.begin();
1045        r != requestors.end(); ++r) {
1046     if (HandleOneCheck(*r, full_hashes))
1047       hit = true;
1048   }
1049   RecordGetHashCheckStatus(hit, check_type, full_hashes);
1050
1051   gethash_requests_.erase(it);
1052 }
1053
1054 bool SafeBrowsingDatabaseManager::HandleOneCheck(
1055     SafeBrowsingCheck* check,
1056     const std::vector<SBFullHashResult>& full_hashes) {
1057   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1058   DCHECK(check);
1059
1060   bool is_threat = false;
1061
1062   // TODO(shess): GetHashSeverestThreadListType() contains a loop,
1063   // GetUrlSeverestThreatListType() a loop around that loop.  Having another
1064   // loop out here concerns me.  It is likely that SAFE is an expected outcome,
1065   // which means all of those loops run to completion.  Refactoring this to
1066   // generate a set of sorted items to compare in sequence would probably
1067   // improve things.
1068   //
1069   // Additionally, the set of patterns generated from the urls is very similar
1070   // to the patterns generated in ContainsBrowseUrl() and other database checks,
1071   // which are called from this code.  Refactoring that across the checks could
1072   // interact well with batching the checks here.
1073
1074   // TODO(gab): Fix the fact that Get(Url|Hash)SeverestThreatType() may return a
1075   // threat for which IsExpectedThreat() returns false even if |full_hashes|
1076   // actually contains an expected threat.
1077
1078   for (size_t i = 0; i < check->urls.size(); ++i) {
1079     size_t threat_index;
1080     SBThreatType threat =
1081         GetUrlSeverestThreatType(check->urls[i], full_hashes, &threat_index);
1082     if (threat != SB_THREAT_TYPE_SAFE &&
1083         IsExpectedThreat(threat, check->expected_threats)) {
1084       check->url_results[i] = threat;
1085       check->url_metadata[i] = full_hashes[threat_index].metadata;
1086       is_threat = true;
1087     }
1088   }
1089
1090   for (size_t i = 0; i < check->full_hashes.size(); ++i) {
1091     SBThreatType threat =
1092         GetHashSeverestThreatType(check->full_hashes[i], full_hashes);
1093     if (threat != SB_THREAT_TYPE_SAFE &&
1094         IsExpectedThreat(threat, check->expected_threats)) {
1095       check->full_hash_results[i] = threat;
1096       is_threat = true;
1097     }
1098   }
1099
1100   SafeBrowsingCheckDone(check);
1101   return is_threat;
1102 }
1103
1104 void SafeBrowsingDatabaseManager::CheckDownloadUrlOnSBThread(
1105     SafeBrowsingCheck* check) {
1106   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
1107   DCHECK(enable_download_protection_);
1108
1109   std::vector<SBPrefix> prefix_hits;
1110
1111   if (!database_->ContainsDownloadUrl(check->urls, &prefix_hits)) {
1112     // Good, we don't have hash for this url prefix.
1113     BrowserThread::PostTask(
1114         BrowserThread::IO, FROM_HERE,
1115         base::Bind(&SafeBrowsingDatabaseManager::CheckDownloadUrlDone, this,
1116                    check));
1117     return;
1118   }
1119
1120   check->need_get_hash = true;
1121   check->prefix_hits.clear();
1122   check->prefix_hits = prefix_hits;
1123   BrowserThread::PostTask(
1124       BrowserThread::IO, FROM_HERE,
1125       base::Bind(&SafeBrowsingDatabaseManager::OnCheckDone, this, check));
1126 }
1127
1128 void SafeBrowsingDatabaseManager::CheckExtensionIDsOnSBThread(
1129     SafeBrowsingCheck* check) {
1130   DCHECK(safe_browsing_task_runner_->RunsTasksOnCurrentThread());
1131
1132   std::vector<SBPrefix> prefixes;
1133   for (std::vector<SBFullHash>::iterator it = check->full_hashes.begin();
1134        it != check->full_hashes.end(); ++it) {
1135     prefixes.push_back((*it).prefix);
1136   }
1137   database_->ContainsExtensionPrefixes(prefixes, &check->prefix_hits);
1138
1139   if (check->prefix_hits.empty()) {
1140     // No matches for any extensions.
1141     BrowserThread::PostTask(
1142         BrowserThread::IO,
1143         FROM_HERE,
1144         base::Bind(&SafeBrowsingDatabaseManager::SafeBrowsingCheckDone, this,
1145                    check));
1146   } else {
1147     // Some prefixes matched, we need to ask Google whether they're legit.
1148     check->need_get_hash = true;
1149     BrowserThread::PostTask(
1150         BrowserThread::IO,
1151         FROM_HERE,
1152         base::Bind(&SafeBrowsingDatabaseManager::OnCheckDone, this, check));
1153   }
1154 }
1155
1156 void SafeBrowsingDatabaseManager::TimeoutCallback(SafeBrowsingCheck* check) {
1157   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1158   DCHECK(check);
1159
1160   if (!enabled_)
1161     return;
1162
1163   DCHECK(checks_.find(check) != checks_.end());
1164   if (check->client) {
1165     check->client->OnSafeBrowsingResult(*check);
1166     check->client = NULL;
1167   }
1168 }
1169
1170 void SafeBrowsingDatabaseManager::CheckDownloadUrlDone(
1171     SafeBrowsingCheck* check) {
1172   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1173   DCHECK(enable_download_protection_);
1174   SafeBrowsingCheckDone(check);
1175 }
1176
1177 void SafeBrowsingDatabaseManager::SafeBrowsingCheckDone(
1178     SafeBrowsingCheck* check) {
1179   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1180   DCHECK(check);
1181
1182   if (!enabled_)
1183     return;
1184
1185   DVLOG(1) << "SafeBrowsingCheckDone";
1186   DCHECK(checks_.find(check) != checks_.end());
1187   if (check->client)
1188     check->client->OnSafeBrowsingResult(*check);
1189   checks_.erase(check);
1190   delete check;
1191 }
1192
1193 void SafeBrowsingDatabaseManager::StartSafeBrowsingCheck(
1194     SafeBrowsingCheck* check,
1195     const base::Closure& task) {
1196   DCHECK_CURRENTLY_ON(BrowserThread::IO);
1197   check->timeout_factory_.reset(
1198       new base::WeakPtrFactory<SafeBrowsingDatabaseManager>(this));
1199   checks_.insert(check);
1200
1201   safe_browsing_task_runner_->PostTask(FROM_HERE, task);
1202
1203   base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
1204       base::Bind(&SafeBrowsingDatabaseManager::TimeoutCallback,
1205                  check->timeout_factory_->GetWeakPtr(), check),
1206       check_timeout_);
1207 }