chrome/browser/local_discovery/privet_url_fetcher.cc

   1 // Copyright 2013 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/local_discovery/privet_url_fetcher.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/json/json_reader.h"
  11 #include "base/memory/singleton.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/rand_util.h"
  14 #include "base/strings/stringprintf.h"
  15 #include "chrome/browser/browser_process.h"
  16 #include "chrome/browser/local_discovery/privet_constants.h"
  17 #include "content/public/browser/browser_thread.h"
  18 #include "net/http/http_status_code.h"
  19 #include "net/url_request/url_request_status.h"
  20
  21 namespace local_discovery {
  22
  23 namespace {
  24
  25 typedef std::map<std::string, std::string> TokenMap;
  26
  27 struct TokenMapHolder {
  28  public:
  29   static TokenMapHolder* GetInstance() {
  30     return Singleton<TokenMapHolder>::get();
  31   }
  32
  33   TokenMap map;
  34 };
  35
  36 const char kXPrivetTokenHeaderPrefix[] = "X-Privet-Token: ";
  37 const char kXPrivetAuthTokenHeaderPrefix[] = "X-Privet-Auth: ";
  38 const char kRangeHeaderFormat[] = "Range: bytes=%d-%d";
  39 const char kXPrivetEmptyToken[] = "\"\"";
  40 const char kPrivetAuthTokenUnknown[] = "Unknown";
  41 const int kPrivetMaxRetries = 20;
  42 const int kPrivetTimeoutOnError = 5;
  43 const int kHTTPErrorCodeInvalidXPrivetToken = 418;
  44
  45 std::string MakeRangeHeader(int start, int end) {
  46   DCHECK_GE(start, 0);
  47   DCHECK_GT(end, 0);
  48   DCHECK_GT(end, start);
  49   return base::StringPrintf(kRangeHeaderFormat, start, end);
  50 }
  51
  52 }  // namespace
  53
  54 void PrivetURLFetcher::Delegate::OnNeedPrivetToken(
  55     PrivetURLFetcher* fetcher,
  56     const TokenCallback& callback) {
  57   OnError(fetcher, TOKEN_ERROR);
  58 }
  59
  60 std::string PrivetURLFetcher::Delegate::GetAuthToken() {
  61   return kPrivetAuthTokenUnknown;
  62 }
  63
  64 bool PrivetURLFetcher::Delegate::OnRawData(PrivetURLFetcher* fetcher,
  65                                            bool response_is_file,
  66                                            const std::string& data_string,
  67                                            const base::FilePath& data_file) {
  68   return false;
  69 }
  70
  71 PrivetURLFetcher::PrivetURLFetcher(
  72     const GURL& url,
  73     net::URLFetcher::RequestType request_type,
  74     net::URLRequestContextGetter* request_context,
  75     PrivetURLFetcher::Delegate* delegate)
  76     : url_(url),
  77       request_type_(request_type),
  78       request_context_(request_context),
  79       delegate_(delegate),
  80       do_not_retry_on_transient_error_(false),
  81       send_empty_privet_token_(false),
  82       has_byte_range_(false),
  83       make_response_file_(false),
  84       v3_mode_(false),
  85       byte_range_start_(0),
  86       byte_range_end_(0),
  87       tries_(0),
  88       weak_factory_(this) {
  89 }
  90
  91 PrivetURLFetcher::~PrivetURLFetcher() {
  92 }
  93
  94 // static
  95 void PrivetURLFetcher::SetTokenForHost(const std::string& host,
  96                                        const std::string& token) {
  97   TokenMapHolder::GetInstance()->map[host] = token;
  98 }
  99
 100 // static
 101 void PrivetURLFetcher::ResetTokenMapForTests() {
 102   TokenMapHolder::GetInstance()->map.clear();
 103 }
 104
 105 void PrivetURLFetcher::DoNotRetryOnTransientError() {
 106   DCHECK(tries_ == 0);
 107   do_not_retry_on_transient_error_ = true;
 108 }
 109
 110 void PrivetURLFetcher::SendEmptyPrivetToken() {
 111   DCHECK(tries_ == 0);
 112   send_empty_privet_token_ = true;
 113 }
 114
 115 std::string PrivetURLFetcher::GetPrivetAccessToken() {
 116   if (send_empty_privet_token_) {
 117     return std::string();
 118   }
 119
 120   TokenMapHolder* token_map_holder = TokenMapHolder::GetInstance();
 121   TokenMap::iterator found = token_map_holder->map.find(GetHostString());
 122   return found != token_map_holder->map.end() ? found->second : std::string();
 123 }
 124
 125 std::string PrivetURLFetcher::GetHostString() {
 126   return url_.GetOrigin().spec();
 127 }
 128
 129 void PrivetURLFetcher::SaveResponseToFile() {
 130   DCHECK(tries_ == 0);
 131   make_response_file_ = true;
 132 }
 133
 134 void PrivetURLFetcher::V3Mode() {
 135   v3_mode_ = true;
 136 }
 137
 138 void PrivetURLFetcher::SetByteRange(int start, int end) {
 139   DCHECK(tries_ == 0);
 140   byte_range_start_ = start;
 141   byte_range_end_ = end;
 142   has_byte_range_ = true;
 143 }
 144
 145 void PrivetURLFetcher::Try() {
 146   tries_++;
 147   if (tries_ < kPrivetMaxRetries) {
 148
 149
 150     url_fetcher_.reset(net::URLFetcher::Create(url_, request_type_, this));
 151     url_fetcher_->SetRequestContext(request_context_.get());
 152
 153     if (v3_mode_) {
 154       std::string auth_token = delegate_->GetAuthToken();
 155
 156       url_fetcher_->AddExtraRequestHeader(
 157           std::string(kXPrivetAuthTokenHeaderPrefix) + auth_token);
 158     } else {
 159       std::string token = GetPrivetAccessToken();
 160
 161       if (token.empty())
 162         token = kXPrivetEmptyToken;
 163
 164       url_fetcher_->AddExtraRequestHeader(
 165           std::string(kXPrivetTokenHeaderPrefix) + token);
 166     }
 167
 168     if (has_byte_range_) {
 169       url_fetcher_->AddExtraRequestHeader(
 170           MakeRangeHeader(byte_range_start_, byte_range_end_));
 171     }
 172
 173     if (make_response_file_) {
 174       url_fetcher_->SaveResponseToTemporaryFile(
 175           content::BrowserThread::GetMessageLoopProxyForThread(
 176               content::BrowserThread::FILE));
 177     }
 178
 179     // URLFetcher requires us to set upload data for POST requests.
 180     if (request_type_ == net::URLFetcher::POST) {
 181       if (!upload_file_path_.empty()) {
 182         url_fetcher_->SetUploadFilePath(
 183             upload_content_type_,
 184             upload_file_path_,
 185             0 /*offset*/,
 186             kuint64max /*length*/,
 187             content::BrowserThread::GetMessageLoopProxyForThread(
 188                 content::BrowserThread::FILE));
 189       } else {
 190         url_fetcher_->SetUploadData(upload_content_type_, upload_data_);
 191       }
 192     }
 193
 194     url_fetcher_->Start();
 195   } else {
 196     delegate_->OnError(this, RETRY_ERROR);
 197   }
 198 }
 199
 200 void PrivetURLFetcher::Start() {
 201   DCHECK_EQ(tries_, 0);  // We haven't called |Start()| yet.
 202
 203   if (!send_empty_privet_token_ && !v3_mode_) {
 204     std::string privet_access_token;
 205     privet_access_token = GetPrivetAccessToken();
 206     if (privet_access_token.empty()) {
 207       RequestTokenRefresh();
 208       return;
 209     }
 210   }
 211
 212   Try();
 213 }
 214
 215 void PrivetURLFetcher::SetUploadData(const std::string& upload_content_type,
 216                                      const std::string& upload_data) {
 217   DCHECK(upload_file_path_.empty());
 218   upload_content_type_ = upload_content_type;
 219   upload_data_ = upload_data;
 220 }
 221
 222 void PrivetURLFetcher::SetUploadFilePath(
 223     const std::string& upload_content_type,
 224     const base::FilePath& upload_file_path) {
 225   DCHECK(upload_data_.empty());
 226   upload_content_type_ = upload_content_type;
 227   upload_file_path_ = upload_file_path;
 228 }
 229
 230 void PrivetURLFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
 231   if (source->GetResponseCode() == net::HTTP_SERVICE_UNAVAILABLE) {
 232     ScheduleRetry(kPrivetTimeoutOnError);
 233     return;
 234   }
 235
 236   if (!OnURLFetchCompleteDoNotParseData(source)) {
 237     // Byte ranges should only be used when we're not parsing the data
 238     // as JSON.
 239     DCHECK(!has_byte_range_);
 240
 241     // We should only be saving raw data to a file.
 242     DCHECK(!make_response_file_);
 243
 244     OnURLFetchCompleteParseData(source);
 245   }
 246 }
 247
 248 // Note that this function returns "true" in error cases to indicate
 249 // that it has fully handled the responses.
 250 bool PrivetURLFetcher::OnURLFetchCompleteDoNotParseData(
 251     const net::URLFetcher* source) {
 252   if (source->GetResponseCode() == kHTTPErrorCodeInvalidXPrivetToken) {
 253     RequestTokenRefresh();
 254     return true;
 255   }
 256
 257   if (source->GetResponseCode() != net::HTTP_OK &&
 258       source->GetResponseCode() != net::HTTP_PARTIAL_CONTENT) {
 259     delegate_->OnError(this, RESPONSE_CODE_ERROR);
 260     return true;
 261   }
 262
 263   if (make_response_file_) {
 264     base::FilePath response_file_path;
 265
 266     if (!source->GetResponseAsFilePath(true, &response_file_path)) {
 267       delegate_->OnError(this, URL_FETCH_ERROR);
 268       return true;
 269     }
 270
 271     return delegate_->OnRawData(this, true, std::string(), response_file_path);
 272   } else {
 273     std::string response_str;
 274
 275     if (!source->GetResponseAsString(&response_str)) {
 276       delegate_->OnError(this, URL_FETCH_ERROR);
 277       return true;
 278     }
 279
 280     return delegate_->OnRawData(this, false, response_str, base::FilePath());
 281   }
 282 }
 283
 284 void PrivetURLFetcher::OnURLFetchCompleteParseData(
 285     const net::URLFetcher* source) {
 286   if (source->GetResponseCode() != net::HTTP_OK) {
 287     delegate_->OnError(this, RESPONSE_CODE_ERROR);
 288     return;
 289   }
 290
 291   std::string response_str;
 292
 293   if (!source->GetResponseAsString(&response_str)) {
 294     delegate_->OnError(this, URL_FETCH_ERROR);
 295     return;
 296   }
 297
 298   base::JSONReader json_reader(base::JSON_ALLOW_TRAILING_COMMAS);
 299   scoped_ptr<base::Value> value;
 300
 301   value.reset(json_reader.ReadToValue(response_str));
 302
 303   if (!value) {
 304     delegate_->OnError(this, JSON_PARSE_ERROR);
 305     return;
 306   }
 307
 308   const base::DictionaryValue* dictionary_value = NULL;
 309
 310   if (!value->GetAsDictionary(&dictionary_value)) {
 311     delegate_->OnError(this, JSON_PARSE_ERROR);
 312     return;
 313   }
 314
 315   std::string error;
 316   if (dictionary_value->GetString(kPrivetKeyError, &error)) {
 317     if (error == kPrivetErrorInvalidXPrivetToken) {
 318       RequestTokenRefresh();
 319       return;
 320     } else if (PrivetErrorTransient(error)) {
 321       if (!do_not_retry_on_transient_error_) {
 322         int timeout_seconds;
 323         if (!dictionary_value->GetInteger(kPrivetKeyTimeout,
 324                                           &timeout_seconds)) {
 325           timeout_seconds = kPrivetDefaultTimeout;
 326         }
 327
 328         ScheduleRetry(timeout_seconds);
 329         return;
 330       }
 331     }
 332   }
 333
 334   delegate_->OnParsedJson(
 335       this, *dictionary_value, dictionary_value->HasKey(kPrivetKeyError));
 336 }
 337
 338 void PrivetURLFetcher::ScheduleRetry(int timeout_seconds) {
 339   double random_scaling_factor =
 340       1 + base::RandDouble() * kPrivetMaximumTimeRandomAddition;
 341
 342   int timeout_seconds_randomized =
 343       static_cast<int>(timeout_seconds * random_scaling_factor);
 344
 345   timeout_seconds_randomized =
 346       std::max(timeout_seconds_randomized, kPrivetMinimumTimeout);
 347
 348   base::MessageLoop::current()->PostDelayedTask(
 349       FROM_HERE,
 350       base::Bind(&PrivetURLFetcher::Try, weak_factory_.GetWeakPtr()),
 351       base::TimeDelta::FromSeconds(timeout_seconds_randomized));
 352 }
 353
 354 void PrivetURLFetcher::RequestTokenRefresh() {
 355   delegate_->OnNeedPrivetToken(
 356       this,
 357       base::Bind(&PrivetURLFetcher::RefreshToken, weak_factory_.GetWeakPtr()));
 358 }
 359
 360 void PrivetURLFetcher::RefreshToken(const std::string& token) {
 361   if (token.empty()) {
 362     delegate_->OnError(this, TOKEN_ERROR);
 363   } else {
 364     SetTokenForHost(GetHostString(), token);
 365     Try();
 366   }
 367 }
 368
 369 bool PrivetURLFetcher::PrivetErrorTransient(const std::string& error) {
 370   return (error == kPrivetErrorDeviceBusy) ||
 371          (error == kPrivetV3ErrorDeviceBusy) ||
 372          (error == kPrivetErrorPendingUserAction) ||
 373          (error == kPrivetErrorPrinterBusy);
 374 }
 375
 376 }  // namespace local_discovery