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