chrome/browser/safe_browsing/protocol_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/protocol_manager.h"
   6
   7 #include "base/environment.h"
   8 #include "base/logging.h"
   9 #include "base/memory/scoped_vector.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/profiler/scoped_profile.h"
  12 #include "base/rand_util.h"
  13 #include "base/stl_util.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/strings/stringprintf.h"
  16 #include "base/timer/timer.h"
  17 #include "chrome/browser/safe_browsing/protocol_parser.h"
  18 #include "chrome/common/chrome_version_info.h"
  19 #include "chrome/common/env_vars.h"
  20 #include "google_apis/google_api_keys.h"
  21 #include "net/base/escape.h"
  22 #include "net/base/load_flags.h"
  23 #include "net/base/net_errors.h"
  24 #include "net/url_request/url_fetcher.h"
  25 #include "net/url_request/url_request_context_getter.h"
  26 #include "net/url_request/url_request_status.h"
  27
  28 #if defined(OS_ANDROID)
  29 #include "net/base/network_change_notifier.h"
  30 #endif
  31
  32 using base::Time;
  33 using base::TimeDelta;
  34
  35 namespace {
  36
  37 // UpdateResult indicates what happened with the primary and/or backup update
  38 // requests. The ordering of the values must stay the same for UMA consistency,
  39 // and is also ordered in this way to match ProtocolManager::BackupUpdateReason.
  40 enum UpdateResult {
  41   UPDATE_RESULT_FAIL,
  42   UPDATE_RESULT_SUCCESS,
  43   UPDATE_RESULT_BACKUP_CONNECT_FAIL,
  44   UPDATE_RESULT_BACKUP_CONNECT_SUCCESS,
  45   UPDATE_RESULT_BACKUP_HTTP_FAIL,
  46   UPDATE_RESULT_BACKUP_HTTP_SUCCESS,
  47   UPDATE_RESULT_BACKUP_NETWORK_FAIL,
  48   UPDATE_RESULT_BACKUP_NETWORK_SUCCESS,
  49   UPDATE_RESULT_MAX,
  50   UPDATE_RESULT_BACKUP_START = UPDATE_RESULT_BACKUP_CONNECT_FAIL,
  51 };
  52
  53 void RecordUpdateResult(UpdateResult result) {
  54   DCHECK(result >= 0 && result < UPDATE_RESULT_MAX);
  55   UMA_HISTOGRAM_ENUMERATION("SB2.UpdateResult", result, UPDATE_RESULT_MAX);
  56 }
  57
  58 }  // namespace
  59
  60 // Minimum time, in seconds, from start up before we must issue an update query.
  61 static const int kSbTimerStartIntervalSecMin = 60;
  62
  63 // Maximum time, in seconds, from start up before we must issue an update query.
  64 static const int kSbTimerStartIntervalSecMax = 300;
  65
  66 // The maximum time, in seconds, to wait for a response to an update request.
  67 static const int kSbMaxUpdateWaitSec = 30;
  68
  69 // Maximum back off multiplier.
  70 static const size_t kSbMaxBackOff = 8;
  71
  72 // The default SBProtocolManagerFactory.
  73 class SBProtocolManagerFactoryImpl : public SBProtocolManagerFactory {
  74  public:
  75   SBProtocolManagerFactoryImpl() { }
  76   virtual ~SBProtocolManagerFactoryImpl() { }
  77   virtual SafeBrowsingProtocolManager* CreateProtocolManager(
  78       SafeBrowsingProtocolManagerDelegate* delegate,
  79       net::URLRequestContextGetter* request_context_getter,
  80       const SafeBrowsingProtocolConfig& config) override {
  81     return new SafeBrowsingProtocolManager(
  82         delegate, request_context_getter, config);
  83   }
  84  private:
  85   DISALLOW_COPY_AND_ASSIGN(SBProtocolManagerFactoryImpl);
  86 };
  87
  88 // SafeBrowsingProtocolManager implementation ----------------------------------
  89
  90 // static
  91 SBProtocolManagerFactory* SafeBrowsingProtocolManager::factory_ = NULL;
  92
  93 // static
  94 SafeBrowsingProtocolManager* SafeBrowsingProtocolManager::Create(
  95     SafeBrowsingProtocolManagerDelegate* delegate,
  96     net::URLRequestContextGetter* request_context_getter,
  97     const SafeBrowsingProtocolConfig& config) {
  98   if (!factory_)
  99     factory_ = new SBProtocolManagerFactoryImpl();
 100   return factory_->CreateProtocolManager(
 101       delegate, request_context_getter, config);
 102 }
 103
 104 SafeBrowsingProtocolManager::SafeBrowsingProtocolManager(
 105     SafeBrowsingProtocolManagerDelegate* delegate,
 106     net::URLRequestContextGetter* request_context_getter,
 107     const SafeBrowsingProtocolConfig& config)
 108     : delegate_(delegate),
 109       request_type_(NO_REQUEST),
 110       update_error_count_(0),
 111       gethash_error_count_(0),
 112       update_back_off_mult_(1),
 113       gethash_back_off_mult_(1),
 114       next_update_interval_(base::TimeDelta::FromSeconds(
 115           base::RandInt(kSbTimerStartIntervalSecMin,
 116                         kSbTimerStartIntervalSecMax))),
 117       update_state_(FIRST_REQUEST),
 118       chunk_pending_to_write_(false),
 119       version_(config.version),
 120       update_size_(0),
 121       client_name_(config.client_name),
 122       request_context_getter_(request_context_getter),
 123       url_prefix_(config.url_prefix),
 124       backup_update_reason_(BACKUP_UPDATE_REASON_MAX),
 125       disable_auto_update_(config.disable_auto_update),
 126 #if defined(OS_ANDROID)
 127       disable_connection_check_(config.disable_connection_check),
 128 #endif
 129       url_fetcher_id_(0),
 130       app_in_foreground_(true) {
 131   DCHECK(!url_prefix_.empty());
 132
 133   backup_url_prefixes_[BACKUP_UPDATE_REASON_CONNECT] =
 134       config.backup_connect_error_url_prefix;
 135   backup_url_prefixes_[BACKUP_UPDATE_REASON_HTTP] =
 136       config.backup_http_error_url_prefix;
 137   backup_url_prefixes_[BACKUP_UPDATE_REASON_NETWORK] =
 138       config.backup_network_error_url_prefix;
 139
 140   // Set the backoff multiplier fuzz to a random value between 0 and 1.
 141   back_off_fuzz_ = static_cast<float>(base::RandDouble());
 142   if (version_.empty())
 143     version_ = SafeBrowsingProtocolManagerHelper::Version();
 144 }
 145
 146 // static
 147 void SafeBrowsingProtocolManager::RecordGetHashResult(
 148     bool is_download, ResultType result_type) {
 149   if (is_download) {
 150     UMA_HISTOGRAM_ENUMERATION("SB2.GetHashResultDownload", result_type,
 151                               GET_HASH_RESULT_MAX);
 152   } else {
 153     UMA_HISTOGRAM_ENUMERATION("SB2.GetHashResult", result_type,
 154                               GET_HASH_RESULT_MAX);
 155   }
 156 }
 157
 158 bool SafeBrowsingProtocolManager::IsUpdateScheduled() const {
 159   return update_timer_.IsRunning();
 160 }
 161
 162 SafeBrowsingProtocolManager::~SafeBrowsingProtocolManager() {
 163   // Delete in-progress SafeBrowsing requests.
 164   STLDeleteContainerPairFirstPointers(hash_requests_.begin(),
 165                                       hash_requests_.end());
 166   hash_requests_.clear();
 167 }
 168
 169 // We can only have one update or chunk request outstanding, but there may be
 170 // multiple GetHash requests pending since we don't want to serialize them and
 171 // slow down the user.
 172 void SafeBrowsingProtocolManager::GetFullHash(
 173     const std::vector<SBPrefix>& prefixes,
 174     FullHashCallback callback,
 175     bool is_download) {
 176   DCHECK(CalledOnValidThread());
 177   // If we are in GetHash backoff, we need to check if we're past the next
 178   // allowed time. If we are, we can proceed with the request. If not, we are
 179   // required to return empty results (i.e. treat the page as safe).
 180   if (gethash_error_count_ && Time::Now() <= next_gethash_time_) {
 181     RecordGetHashResult(is_download, GET_HASH_BACKOFF_ERROR);
 182     std::vector<SBFullHashResult> full_hashes;
 183     callback.Run(full_hashes, base::TimeDelta());
 184     return;
 185   }
 186   GURL gethash_url = GetHashUrl();
 187   net::URLFetcher* fetcher = net::URLFetcher::Create(
 188       url_fetcher_id_++, gethash_url, net::URLFetcher::POST, this);
 189   hash_requests_[fetcher] = FullHashDetails(callback, is_download);
 190
 191   const std::string get_hash = safe_browsing::FormatGetHash(prefixes);
 192
 193   fetcher->SetLoadFlags(net::LOAD_DISABLE_CACHE);
 194   fetcher->SetRequestContext(request_context_getter_.get());
 195   fetcher->SetUploadData("text/plain", get_hash);
 196   fetcher->Start();
 197 }
 198
 199 void SafeBrowsingProtocolManager::GetNextUpdate() {
 200   DCHECK(CalledOnValidThread());
 201   if (request_.get() || request_type_ != NO_REQUEST)
 202     return;
 203
 204 #if defined(OS_ANDROID)
 205   if (!disable_connection_check_) {
 206     net::NetworkChangeNotifier::ConnectionType type =
 207       net::NetworkChangeNotifier::GetConnectionType();
 208     if (type != net::NetworkChangeNotifier::CONNECTION_WIFI) {
 209       ScheduleNextUpdate(false /* no back off */);
 210       return;
 211     }
 212   }
 213 #endif
 214
 215   IssueUpdateRequest();
 216 }
 217
 218 // net::URLFetcherDelegate implementation ----------------------------------
 219
 220 // All SafeBrowsing request responses are handled here.
 221 // TODO(paulg): Clarify with the SafeBrowsing team whether a failed parse of a
 222 //              chunk should retry the download and parse of that chunk (and
 223 //              what back off / how many times to try), and if that effects the
 224 //              update back off. For now, a failed parse of the chunk means we
 225 //              drop it. This isn't so bad because the next UPDATE_REQUEST we
 226 //              do will report all the chunks we have. If that chunk is still
 227 //              required, the SafeBrowsing servers will tell us to get it again.
 228 void SafeBrowsingProtocolManager::OnURLFetchComplete(
 229     const net::URLFetcher* source) {
 230   // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
 231   tracked_objects::ScopedProfile tracking_profile(
 232       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 233           "422577 SafeBrowsingProtocolManager::OnURLFetchComplete"));
 234
 235   DCHECK(CalledOnValidThread());
 236   scoped_ptr<const net::URLFetcher> fetcher;
 237
 238   HashRequests::iterator it = hash_requests_.find(source);
 239   if (it != hash_requests_.end()) {
 240     // GetHash response.
 241     fetcher.reset(it->first);
 242     const FullHashDetails& details = it->second;
 243     std::vector<SBFullHashResult> full_hashes;
 244     base::TimeDelta cache_lifetime;
 245     if (source->GetStatus().is_success() &&
 246         (source->GetResponseCode() == 200 ||
 247          source->GetResponseCode() == 204)) {
 248       // For tracking our GetHash false positive (204) rate, compared to real
 249       // (200) responses.
 250       if (source->GetResponseCode() == 200)
 251         RecordGetHashResult(details.is_download, GET_HASH_STATUS_200);
 252       else
 253         RecordGetHashResult(details.is_download, GET_HASH_STATUS_204);
 254
 255       gethash_error_count_ = 0;
 256       gethash_back_off_mult_ = 1;
 257       std::string data;
 258       source->GetResponseAsString(&data);
 259       if (!safe_browsing::ParseGetHash(
 260               data.data(), data.length(), &cache_lifetime, &full_hashes)) {
 261         full_hashes.clear();
 262         RecordGetHashResult(details.is_download, GET_HASH_PARSE_ERROR);
 263         // TODO(cbentzel): Should cache_lifetime be set to 0 here? (See
 264         // http://crbug.com/360232.)
 265       }
 266     } else {
 267       HandleGetHashError(Time::Now());
 268       if (source->GetStatus().status() == net::URLRequestStatus::FAILED) {
 269         RecordGetHashResult(details.is_download, GET_HASH_NETWORK_ERROR);
 270         VLOG(1) << "SafeBrowsing GetHash request for: " << source->GetURL()
 271                 << " failed with error: " << source->GetStatus().error();
 272       } else {
 273         RecordGetHashResult(details.is_download, GET_HASH_HTTP_ERROR);
 274         VLOG(1) << "SafeBrowsing GetHash request for: " << source->GetURL()
 275                 << " failed with error: " << source->GetResponseCode();
 276       }
 277     }
 278
 279     // Invoke the callback with full_hashes, even if there was a parse error or
 280     // an error response code (in which case full_hashes will be empty). The
 281     // caller can't be blocked indefinitely.
 282     details.callback.Run(full_hashes, cache_lifetime);
 283
 284     hash_requests_.erase(it);
 285   } else {
 286     // Update or chunk response.
 287     fetcher.reset(request_.release());
 288
 289     if (request_type_ == UPDATE_REQUEST ||
 290         request_type_ == BACKUP_UPDATE_REQUEST) {
 291       if (!fetcher.get()) {
 292         // We've timed out waiting for an update response, so we've cancelled
 293         // the update request and scheduled a new one. Ignore this response.
 294         return;
 295       }
 296
 297       // Cancel the update response timeout now that we have the response.
 298       timeout_timer_.Stop();
 299     }
 300
 301     net::URLRequestStatus status = source->GetStatus();
 302     if (status.is_success() && source->GetResponseCode() == 200) {
 303       // We have data from the SafeBrowsing service.
 304       std::string data;
 305       source->GetResponseAsString(&data);
 306
 307       // TODO(shess): Cleanup the flow of this code so that |parsed_ok| can be
 308       // removed or omitted.
 309       const bool parsed_ok = HandleServiceResponse(
 310           source->GetURL(), data.data(), data.length());
 311       if (!parsed_ok) {
 312         VLOG(1) << "SafeBrowsing request for: " << source->GetURL()
 313                 << " failed parse.";
 314         chunk_request_urls_.clear();
 315         if (request_type_ == UPDATE_REQUEST &&
 316             IssueBackupUpdateRequest(BACKUP_UPDATE_REASON_HTTP)) {
 317           return;
 318         }
 319         UpdateFinished(false);
 320       }
 321
 322       switch (request_type_) {
 323         case CHUNK_REQUEST:
 324           if (parsed_ok) {
 325             chunk_request_urls_.pop_front();
 326             if (chunk_request_urls_.empty() && !chunk_pending_to_write_)
 327               UpdateFinished(true);
 328           }
 329           break;
 330         case UPDATE_REQUEST:
 331         case BACKUP_UPDATE_REQUEST:
 332           if (chunk_request_urls_.empty() && parsed_ok) {
 333             // We are up to date since the servers gave us nothing new, so we
 334             // are done with this update cycle.
 335             UpdateFinished(true);
 336           }
 337           break;
 338         case NO_REQUEST:
 339           // This can happen if HandleServiceResponse fails above.
 340           break;
 341         default:
 342           NOTREACHED();
 343           break;
 344       }
 345     } else {
 346       if (status.status() == net::URLRequestStatus::FAILED) {
 347         VLOG(1) << "SafeBrowsing request for: " << source->GetURL()
 348                 << " failed with error: " << source->GetStatus().error();
 349       } else {
 350         VLOG(1) << "SafeBrowsing request for: " << source->GetURL()
 351                 << " failed with error: " << source->GetResponseCode();
 352       }
 353       if (request_type_ == CHUNK_REQUEST) {
 354         // The SafeBrowsing service error, or very bad response code: back off.
 355         chunk_request_urls_.clear();
 356       } else if (request_type_ == UPDATE_REQUEST) {
 357         BackupUpdateReason backup_update_reason = BACKUP_UPDATE_REASON_MAX;
 358         if (status.is_success()) {
 359           backup_update_reason = BACKUP_UPDATE_REASON_HTTP;
 360         } else {
 361           switch (status.error()) {
 362             case net::ERR_INTERNET_DISCONNECTED:
 363             case net::ERR_NETWORK_CHANGED:
 364               backup_update_reason = BACKUP_UPDATE_REASON_NETWORK;
 365               break;
 366             default:
 367               backup_update_reason = BACKUP_UPDATE_REASON_CONNECT;
 368               break;
 369           }
 370         }
 371         if (backup_update_reason != BACKUP_UPDATE_REASON_MAX &&
 372             IssueBackupUpdateRequest(backup_update_reason)) {
 373           return;
 374         }
 375       }
 376       UpdateFinished(false);
 377     }
 378   }
 379
 380   // Get the next chunk if available.
 381   IssueChunkRequest();
 382 }
 383
 384 bool SafeBrowsingProtocolManager::HandleServiceResponse(
 385     const GURL& url, const char* data, size_t length) {
 386   DCHECK(CalledOnValidThread());
 387
 388   switch (request_type_) {
 389     case UPDATE_REQUEST:
 390     case BACKUP_UPDATE_REQUEST: {
 391       size_t next_update_sec = 0;
 392       bool reset = false;
 393       scoped_ptr<std::vector<SBChunkDelete> > chunk_deletes(
 394           new std::vector<SBChunkDelete>);
 395       std::vector<ChunkUrl> chunk_urls;
 396       if (!safe_browsing::ParseUpdate(data, length, &next_update_sec, &reset,
 397                                       chunk_deletes.get(), &chunk_urls)) {
 398         return false;
 399       }
 400
 401       base::TimeDelta next_update_interval =
 402           base::TimeDelta::FromSeconds(next_update_sec);
 403       last_update_ = Time::Now();
 404
 405       if (update_state_ == FIRST_REQUEST)
 406         update_state_ = SECOND_REQUEST;
 407       else if (update_state_ == SECOND_REQUEST)
 408         update_state_ = NORMAL_REQUEST;
 409
 410       // New time for the next update.
 411       if (next_update_interval > base::TimeDelta()) {
 412         next_update_interval_ = next_update_interval;
 413       } else if (update_state_ == SECOND_REQUEST) {
 414         next_update_interval_ = base::TimeDelta::FromSeconds(
 415             base::RandInt(15, 45));
 416       }
 417
 418       // New chunks to download.
 419       if (!chunk_urls.empty()) {
 420         UMA_HISTOGRAM_COUNTS("SB2.UpdateUrls", chunk_urls.size());
 421         for (size_t i = 0; i < chunk_urls.size(); ++i)
 422           chunk_request_urls_.push_back(chunk_urls[i]);
 423       }
 424
 425       // Handle the case were the SafeBrowsing service tells us to dump our
 426       // database.
 427       if (reset) {
 428         delegate_->ResetDatabase();
 429         return true;
 430       }
 431
 432       // Chunks to delete from our storage.
 433       if (!chunk_deletes->empty())
 434         delegate_->DeleteChunks(chunk_deletes.Pass());
 435
 436       break;
 437     }
 438     case CHUNK_REQUEST: {
 439       UMA_HISTOGRAM_TIMES("SB2.ChunkRequest",
 440                           base::Time::Now() - chunk_request_start_);
 441
 442       const ChunkUrl chunk_url = chunk_request_urls_.front();
 443       scoped_ptr<ScopedVector<SBChunkData> >
 444           chunks(new ScopedVector<SBChunkData>);
 445       UMA_HISTOGRAM_COUNTS("SB2.ChunkSize", length);
 446       update_size_ += length;
 447       if (!safe_browsing::ParseChunk(data, length, chunks.get()))
 448         return false;
 449
 450       // Chunks to add to storage.  Pass ownership of |chunks|.
 451       if (!chunks->empty()) {
 452         chunk_pending_to_write_ = true;
 453         delegate_->AddChunks(
 454             chunk_url.list_name, chunks.Pass(),
 455             base::Bind(&SafeBrowsingProtocolManager::OnAddChunksComplete,
 456                        base::Unretained(this)));
 457       }
 458
 459       break;
 460     }
 461
 462     default:
 463       return false;
 464   }
 465
 466   return true;
 467 }
 468
 469 void SafeBrowsingProtocolManager::Initialize() {
 470   DCHECK(CalledOnValidThread());
 471   // Don't want to hit the safe browsing servers on build/chrome bots.
 472   scoped_ptr<base::Environment> env(base::Environment::Create());
 473   if (env->HasVar(env_vars::kHeadless))
 474     return;
 475   ScheduleNextUpdate(false /* no back off */);
 476 }
 477
 478 void SafeBrowsingProtocolManager::ScheduleNextUpdate(bool back_off) {
 479   DCHECK(CalledOnValidThread());
 480   if (disable_auto_update_) {
 481     // Unschedule any current timer.
 482     update_timer_.Stop();
 483     return;
 484   }
 485   // Reschedule with the new update.
 486   base::TimeDelta next_update_interval = GetNextUpdateInterval(back_off);
 487   ForceScheduleNextUpdate(next_update_interval);
 488 }
 489
 490 void SafeBrowsingProtocolManager::ForceScheduleNextUpdate(
 491     base::TimeDelta interval) {
 492   DCHECK(CalledOnValidThread());
 493   DCHECK(interval >= base::TimeDelta());
 494   // Unschedule any current timer.
 495   update_timer_.Stop();
 496   update_timer_.Start(FROM_HERE, interval, this,
 497                       &SafeBrowsingProtocolManager::GetNextUpdate);
 498 }
 499
 500 // According to section 5 of the SafeBrowsing protocol specification, we must
 501 // back off after a certain number of errors. We only change |next_update_sec_|
 502 // when we receive a response from the SafeBrowsing service.
 503 base::TimeDelta SafeBrowsingProtocolManager::GetNextUpdateInterval(
 504     bool back_off) {
 505   DCHECK(CalledOnValidThread());
 506   DCHECK(next_update_interval_ > base::TimeDelta());
 507   base::TimeDelta next = next_update_interval_;
 508   if (back_off) {
 509     next = GetNextBackOffInterval(&update_error_count_, &update_back_off_mult_);
 510   } else {
 511     // Successful response means error reset.
 512     update_error_count_ = 0;
 513     update_back_off_mult_ = 1;
 514   }
 515   return next;
 516 }
 517
 518 base::TimeDelta SafeBrowsingProtocolManager::GetNextBackOffInterval(
 519     size_t* error_count, size_t* multiplier) const {
 520   DCHECK(CalledOnValidThread());
 521   DCHECK(multiplier && error_count);
 522   (*error_count)++;
 523   if (*error_count > 1 && *error_count < 6) {
 524     base::TimeDelta next = base::TimeDelta::FromMinutes(
 525         *multiplier * (1 + back_off_fuzz_) * 30);
 526     *multiplier *= 2;
 527     if (*multiplier > kSbMaxBackOff)
 528       *multiplier = kSbMaxBackOff;
 529     return next;
 530   }
 531   if (*error_count >= 6)
 532     return base::TimeDelta::FromHours(8);
 533   return base::TimeDelta::FromMinutes(1);
 534 }
 535
 536 // This request requires getting a list of all the chunks for each list from the
 537 // database asynchronously. The request will be issued when we're called back in
 538 // OnGetChunksComplete.
 539 // TODO(paulg): We should get this at start up and maintain a ChunkRange cache
 540 //              to avoid hitting the database with each update request. On the
 541 //              otherhand, this request will only occur ~20-30 minutes so there
 542 //              isn't that much overhead. Measure!
 543 void SafeBrowsingProtocolManager::IssueUpdateRequest() {
 544   DCHECK(CalledOnValidThread());
 545   request_type_ = UPDATE_REQUEST;
 546   delegate_->UpdateStarted();
 547   delegate_->GetChunks(
 548       base::Bind(&SafeBrowsingProtocolManager::OnGetChunksComplete,
 549                  base::Unretained(this)));
 550 }
 551
 552 // The backup request can run immediately since the chunks have already been
 553 // retrieved from the DB.
 554 bool SafeBrowsingProtocolManager::IssueBackupUpdateRequest(
 555     BackupUpdateReason backup_update_reason) {
 556   DCHECK(CalledOnValidThread());
 557   DCHECK_EQ(request_type_, UPDATE_REQUEST);
 558   DCHECK(backup_update_reason >= 0 &&
 559          backup_update_reason < BACKUP_UPDATE_REASON_MAX);
 560   if (backup_url_prefixes_[backup_update_reason].empty())
 561     return false;
 562   request_type_ = BACKUP_UPDATE_REQUEST;
 563   backup_update_reason_ = backup_update_reason;
 564
 565   GURL backup_update_url = BackupUpdateUrl(backup_update_reason);
 566   request_.reset(net::URLFetcher::Create(
 567       url_fetcher_id_++, backup_update_url, net::URLFetcher::POST, this));
 568   request_->SetLoadFlags(net::LOAD_DISABLE_CACHE);
 569   request_->SetRequestContext(request_context_getter_.get());
 570   request_->SetUploadData("text/plain", update_list_data_);
 571   request_->Start();
 572
 573   // Begin the update request timeout.
 574   timeout_timer_.Start(FROM_HERE, TimeDelta::FromSeconds(kSbMaxUpdateWaitSec),
 575                        this,
 576                        &SafeBrowsingProtocolManager::UpdateResponseTimeout);
 577
 578   return true;
 579 }
 580
 581 void SafeBrowsingProtocolManager::IssueChunkRequest() {
 582   DCHECK(CalledOnValidThread());
 583   // We are only allowed to have one request outstanding at any time.  Also,
 584   // don't get the next url until the previous one has been written to disk so
 585   // that we don't use too much memory.
 586   if (request_.get() || chunk_request_urls_.empty() || chunk_pending_to_write_)
 587     return;
 588
 589   ChunkUrl next_chunk = chunk_request_urls_.front();
 590   DCHECK(!next_chunk.url.empty());
 591   GURL chunk_url = NextChunkUrl(next_chunk.url);
 592   request_type_ = CHUNK_REQUEST;
 593   request_.reset(net::URLFetcher::Create(
 594       url_fetcher_id_++, chunk_url, net::URLFetcher::GET, this));
 595   request_->SetLoadFlags(net::LOAD_DISABLE_CACHE);
 596   request_->SetRequestContext(request_context_getter_.get());
 597   chunk_request_start_ = base::Time::Now();
 598   request_->Start();
 599 }
 600
 601 void SafeBrowsingProtocolManager::OnGetChunksComplete(
 602     const std::vector<SBListChunkRanges>& lists, bool database_error) {
 603   DCHECK(CalledOnValidThread());
 604   DCHECK_EQ(request_type_, UPDATE_REQUEST);
 605   DCHECK(update_list_data_.empty());
 606   if (database_error) {
 607     // The update was not successful, but don't back off.
 608     UpdateFinished(false, false);
 609     return;
 610   }
 611
 612   // Format our stored chunks:
 613   bool found_malware = false;
 614   bool found_phishing = false;
 615   for (size_t i = 0; i < lists.size(); ++i) {
 616     update_list_data_.append(safe_browsing::FormatList(lists[i]));
 617     if (lists[i].name == safe_browsing_util::kPhishingList)
 618       found_phishing = true;
 619
 620     if (lists[i].name == safe_browsing_util::kMalwareList)
 621       found_malware = true;
 622   }
 623
 624   // If we have an empty database, let the server know we want data for these
 625   // lists.
 626   // TODO(shess): These cases never happen because the database fills in the
 627   // lists in GetChunks().  Refactor the unit tests so that this code can be
 628   // removed.
 629   if (!found_phishing) {
 630     update_list_data_.append(safe_browsing::FormatList(
 631         SBListChunkRanges(safe_browsing_util::kPhishingList)));
 632   }
 633   if (!found_malware) {
 634     update_list_data_.append(safe_browsing::FormatList(
 635         SBListChunkRanges(safe_browsing_util::kMalwareList)));
 636   }
 637
 638   // Large requests are (probably) a sign of database corruption.
 639   // Record stats to inform decisions about whether to automate
 640   // deletion of such databases.  http://crbug.com/120219
 641   UMA_HISTOGRAM_COUNTS("SB2.UpdateRequestSize", update_list_data_.size());
 642
 643   GURL update_url = UpdateUrl();
 644   request_.reset(net::URLFetcher::Create(
 645       url_fetcher_id_++, update_url, net::URLFetcher::POST, this));
 646   request_->SetLoadFlags(net::LOAD_DISABLE_CACHE);
 647   request_->SetRequestContext(request_context_getter_.get());
 648   request_->SetUploadData("text/plain", update_list_data_);
 649   request_->Start();
 650
 651   // Begin the update request timeout.
 652   timeout_timer_.Start(FROM_HERE, TimeDelta::FromSeconds(kSbMaxUpdateWaitSec),
 653                        this,
 654                        &SafeBrowsingProtocolManager::UpdateResponseTimeout);
 655 }
 656
 657 // If we haven't heard back from the server with an update response, this method
 658 // will run. Close the current update session and schedule another update.
 659 void SafeBrowsingProtocolManager::UpdateResponseTimeout() {
 660   DCHECK(CalledOnValidThread());
 661   DCHECK(request_type_ == UPDATE_REQUEST ||
 662          request_type_ == BACKUP_UPDATE_REQUEST);
 663   request_.reset();
 664   if (request_type_ == UPDATE_REQUEST &&
 665       IssueBackupUpdateRequest(BACKUP_UPDATE_REASON_CONNECT)) {
 666     return;
 667   }
 668   UpdateFinished(false);
 669 }
 670
 671 void SafeBrowsingProtocolManager::OnAddChunksComplete() {
 672   DCHECK(CalledOnValidThread());
 673   chunk_pending_to_write_ = false;
 674
 675   if (chunk_request_urls_.empty()) {
 676     UMA_HISTOGRAM_LONG_TIMES("SB2.Update", Time::Now() - last_update_);
 677     UpdateFinished(true);
 678   } else {
 679     IssueChunkRequest();
 680   }
 681 }
 682
 683 void SafeBrowsingProtocolManager::HandleGetHashError(const Time& now) {
 684   DCHECK(CalledOnValidThread());
 685   base::TimeDelta next = GetNextBackOffInterval(
 686       &gethash_error_count_, &gethash_back_off_mult_);
 687   next_gethash_time_ = now + next;
 688 }
 689
 690 void SafeBrowsingProtocolManager::UpdateFinished(bool success) {
 691   UpdateFinished(success, !success);
 692 }
 693
 694 void SafeBrowsingProtocolManager::UpdateFinished(bool success, bool back_off) {
 695   DCHECK(CalledOnValidThread());
 696 #if defined(OS_ANDROID)
 697   if (app_in_foreground_)
 698     UMA_HISTOGRAM_COUNTS("SB2.UpdateSizeForeground", update_size_);
 699   else
 700     UMA_HISTOGRAM_COUNTS("SB2.UpdateSizeBackground", update_size_);
 701 #endif
 702   UMA_HISTOGRAM_COUNTS("SB2.UpdateSize", update_size_);
 703   update_size_ = 0;
 704   bool update_success = success || request_type_ == CHUNK_REQUEST;
 705   if (backup_update_reason_ == BACKUP_UPDATE_REASON_MAX) {
 706     RecordUpdateResult(
 707         update_success ? UPDATE_RESULT_SUCCESS : UPDATE_RESULT_FAIL);
 708   } else {
 709     UpdateResult update_result = static_cast<UpdateResult>(
 710           UPDATE_RESULT_BACKUP_START +
 711           (static_cast<int>(backup_update_reason_) * 2) +
 712           update_success);
 713     RecordUpdateResult(update_result);
 714   }
 715   backup_update_reason_ = BACKUP_UPDATE_REASON_MAX;
 716   request_type_ = NO_REQUEST;
 717   update_list_data_.clear();
 718   delegate_->UpdateFinished(success);
 719   ScheduleNextUpdate(back_off);
 720 }
 721
 722 GURL SafeBrowsingProtocolManager::UpdateUrl() const {
 723   std::string url = SafeBrowsingProtocolManagerHelper::ComposeUrl(
 724       url_prefix_, "downloads", client_name_, version_, additional_query_);
 725   return GURL(url);
 726 }
 727
 728 GURL SafeBrowsingProtocolManager::BackupUpdateUrl(
 729     BackupUpdateReason backup_update_reason) const {
 730   DCHECK(backup_update_reason >= 0 &&
 731          backup_update_reason < BACKUP_UPDATE_REASON_MAX);
 732   DCHECK(!backup_url_prefixes_[backup_update_reason].empty());
 733   std::string url = SafeBrowsingProtocolManagerHelper::ComposeUrl(
 734       backup_url_prefixes_[backup_update_reason], "downloads", client_name_,
 735       version_, additional_query_);
 736   return GURL(url);
 737 }
 738
 739 GURL SafeBrowsingProtocolManager::GetHashUrl() const {
 740   std::string url = SafeBrowsingProtocolManagerHelper::ComposeUrl(
 741       url_prefix_, "gethash", client_name_, version_, additional_query_);
 742   return GURL(url);
 743 }
 744
 745 GURL SafeBrowsingProtocolManager::NextChunkUrl(const std::string& url) const {
 746   DCHECK(CalledOnValidThread());
 747   std::string next_url;
 748   if (!StartsWithASCII(url, "http://", false) &&
 749       !StartsWithASCII(url, "https://", false)) {
 750     // Use https if we updated via https, otherwise http (useful for testing).
 751     if (StartsWithASCII(url_prefix_, "https://", false))
 752       next_url.append("https://");
 753     else
 754       next_url.append("http://");
 755     next_url.append(url);
 756   } else {
 757     next_url = url;
 758   }
 759   if (!additional_query_.empty()) {
 760     if (next_url.find("?") != std::string::npos) {
 761       next_url.append("&");
 762     } else {
 763       next_url.append("?");
 764     }
 765     next_url.append(additional_query_);
 766   }
 767   return GURL(next_url);
 768 }
 769
 770 SafeBrowsingProtocolManager::FullHashDetails::FullHashDetails()
 771     : callback(),
 772       is_download(false) {
 773 }
 774
 775 SafeBrowsingProtocolManager::FullHashDetails::FullHashDetails(
 776     FullHashCallback callback, bool is_download)
 777     : callback(callback),
 778       is_download(is_download) {
 779 }
 780
 781 SafeBrowsingProtocolManager::FullHashDetails::~FullHashDetails() {
 782 }
 783
 784 SafeBrowsingProtocolManagerDelegate::~SafeBrowsingProtocolManagerDelegate() {
 785 }