net/base/sdch_manager_unittest.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <limits.h>
   6
   7 #include <string>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "net/base/sdch_manager.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13
  14 namespace net {
  15
  16 //------------------------------------------------------------------------------
  17 // Provide sample data and compression results with a sample VCDIFF dictionary.
  18 // Note an SDCH dictionary has extra meta-data before the VCDIFF dictionary.
  19 static const char kTestVcdiffDictionary[] = "DictionaryFor"
  20     "SdchCompression1SdchCompression2SdchCompression3SdchCompression\n";
  21
  22 //------------------------------------------------------------------------------
  23
  24 class SdchManagerTest : public testing::Test {
  25  protected:
  26   SdchManagerTest()
  27     : sdch_manager_(new SdchManager) {
  28   }
  29
  30   SdchManager* sdch_manager() { return sdch_manager_.get(); }
  31
  32   // Reset globals back to default state.
  33   virtual void TearDown() {
  34     SdchManager::EnableSdchSupport(true);
  35     SdchManager::EnableSecureSchemeSupport(false);
  36   }
  37
  38  private:
  39   scoped_ptr<SdchManager> sdch_manager_;
  40 };
  41
  42 //------------------------------------------------------------------------------
  43 static std::string NewSdchDictionary(const std::string& domain) {
  44   std::string dictionary;
  45   if (!domain.empty()) {
  46     dictionary.append("Domain: ");
  47     dictionary.append(domain);
  48     dictionary.append("\n");
  49   }
  50   dictionary.append("\n");
  51   dictionary.append(kTestVcdiffDictionary, sizeof(kTestVcdiffDictionary) - 1);
  52   return dictionary;
  53 }
  54
  55 TEST_F(SdchManagerTest, DomainSupported) {
  56   GURL google_url("http://www.google.com");
  57
  58   SdchManager::EnableSdchSupport(false);
  59   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(google_url));
  60   SdchManager::EnableSdchSupport(true);
  61   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(google_url));
  62 }
  63
  64 TEST_F(SdchManagerTest, DomainBlacklisting) {
  65   GURL test_url("http://www.test.com");
  66   GURL google_url("http://www.google.com");
  67
  68   sdch_manager()->BlacklistDomain(test_url, SdchManager::MIN_PROBLEM_CODE);
  69   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(test_url));
  70   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(google_url));
  71
  72   sdch_manager()->BlacklistDomain(google_url, SdchManager::MIN_PROBLEM_CODE);
  73   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(google_url));
  74 }
  75
  76 TEST_F(SdchManagerTest, DomainBlacklistingCaseSensitivity) {
  77   GURL test_url("http://www.TesT.com");
  78   GURL test2_url("http://www.tEst.com");
  79
  80   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(test_url));
  81   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(test2_url));
  82   sdch_manager()->BlacklistDomain(test_url, SdchManager::MIN_PROBLEM_CODE);
  83   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(test2_url));
  84 }
  85
  86 TEST_F(SdchManagerTest, BlacklistingReset) {
  87   GURL gurl("http://mytest.DoMain.com");
  88   std::string domain(gurl.host());
  89
  90   sdch_manager()->ClearBlacklistings();
  91   EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), 0);
  92   EXPECT_EQ(sdch_manager()->BlacklistDomainExponential(domain), 0);
  93   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(gurl));
  94 }
  95
  96 TEST_F(SdchManagerTest, BlacklistingSingleBlacklist) {
  97   GURL gurl("http://mytest.DoMain.com");
  98   std::string domain(gurl.host());
  99   sdch_manager()->ClearBlacklistings();
 100
 101   sdch_manager()->BlacklistDomain(gurl, SdchManager::MIN_PROBLEM_CODE);
 102   EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), 1);
 103   EXPECT_EQ(sdch_manager()->BlacklistDomainExponential(domain), 1);
 104
 105   // Check that any domain lookup reduces the blacklist counter.
 106   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(gurl));
 107   EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), 0);
 108   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(gurl));
 109 }
 110
 111 TEST_F(SdchManagerTest, BlacklistingExponential) {
 112   GURL gurl("http://mytest.DoMain.com");
 113   std::string domain(gurl.host());
 114   sdch_manager()->ClearBlacklistings();
 115
 116   int exponential = 1;
 117   for (int i = 1; i < 100; ++i) {
 118     sdch_manager()->BlacklistDomain(gurl, SdchManager::MIN_PROBLEM_CODE);
 119     EXPECT_EQ(sdch_manager()->BlacklistDomainExponential(domain), exponential);
 120
 121     EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), exponential);
 122     EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(gurl));
 123     EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), exponential - 1);
 124
 125     // Simulate a large number of domain checks (which eventually remove the
 126     // blacklisting).
 127     sdch_manager()->ClearDomainBlacklisting(domain);
 128     EXPECT_EQ(sdch_manager()->BlackListDomainCount(domain), 0);
 129     EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(gurl));
 130
 131     // Predict what exponential backoff will be.
 132     exponential = 1 + 2 * exponential;
 133     if (exponential < 0)
 134       exponential = INT_MAX;  // We don't wrap.
 135   }
 136 }
 137
 138 TEST_F(SdchManagerTest, CanSetExactMatchDictionary) {
 139   std::string dictionary_domain("x.y.z.google.com");
 140   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 141
 142   // Perfect match should work.
 143   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 144               GURL("http://" + dictionary_domain)));
 145 }
 146
 147 TEST_F(SdchManagerTest, CanAdvertiseDictionaryOverHTTP) {
 148   std::string dictionary_domain("x.y.z.google.com");
 149   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 150
 151   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 152               GURL("http://" + dictionary_domain)));
 153
 154   std::string dictionary_list;
 155   // HTTP target URL can advertise dictionary.
 156   sdch_manager()->GetAvailDictionaryList(
 157       GURL("http://" + dictionary_domain + "/test"),
 158       &dictionary_list);
 159   EXPECT_FALSE(dictionary_list.empty());
 160 }
 161
 162 TEST_F(SdchManagerTest, CanNotAdvertiseDictionaryOverHTTPS) {
 163   std::string dictionary_domain("x.y.z.google.com");
 164   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 165
 166   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 167               GURL("http://" + dictionary_domain)));
 168
 169   std::string dictionary_list;
 170   // HTTPS target URL should NOT advertise dictionary.
 171   sdch_manager()->GetAvailDictionaryList(
 172       GURL("https://" + dictionary_domain + "/test"),
 173       &dictionary_list);
 174   EXPECT_TRUE(dictionary_list.empty());
 175 }
 176
 177 TEST_F(SdchManagerTest, CanUseHTTPSDictionaryOverHTTPSIfEnabled) {
 178   std::string dictionary_domain("x.y.z.google.com");
 179   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 180
 181   EXPECT_FALSE(sdch_manager()->AddSdchDictionary(
 182       dictionary_text, GURL("https://" + dictionary_domain)));
 183   SdchManager::EnableSecureSchemeSupport(true);
 184   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(
 185       dictionary_text, GURL("https://" + dictionary_domain)));
 186
 187   GURL target_url("https://" + dictionary_domain + "/test");
 188   std::string dictionary_list;
 189   // HTTPS target URL should advertise dictionary if secure scheme support is
 190   // enabled.
 191   sdch_manager()->GetAvailDictionaryList(target_url, &dictionary_list);
 192   EXPECT_FALSE(dictionary_list.empty());
 193
 194   // Dictionary should be available.
 195   scoped_refptr<SdchManager::Dictionary> dictionary;
 196   std::string client_hash;
 197   std::string server_hash;
 198   sdch_manager()->GenerateHash(dictionary_text, &client_hash, &server_hash);
 199   sdch_manager()->GetVcdiffDictionary(server_hash, target_url, &dictionary);
 200   EXPECT_TRUE(dictionary != NULL);
 201 }
 202
 203 TEST_F(SdchManagerTest, CanNotUseHTTPDictionaryOverHTTPS) {
 204   std::string dictionary_domain("x.y.z.google.com");
 205   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 206
 207   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 208               GURL("http://" + dictionary_domain)));
 209
 210   GURL target_url("https://" + dictionary_domain + "/test");
 211   std::string dictionary_list;
 212   // HTTPS target URL should not advertise dictionary acquired over HTTP even if
 213   // secure scheme support is enabled.
 214   SdchManager::EnableSecureSchemeSupport(true);
 215   sdch_manager()->GetAvailDictionaryList(target_url, &dictionary_list);
 216   EXPECT_TRUE(dictionary_list.empty());
 217
 218   scoped_refptr<SdchManager::Dictionary> dictionary;
 219   std::string client_hash;
 220   std::string server_hash;
 221   sdch_manager()->GenerateHash(dictionary_text, &client_hash, &server_hash);
 222   sdch_manager()->GetVcdiffDictionary(server_hash, target_url, &dictionary);
 223   EXPECT_TRUE(dictionary == NULL);
 224 }
 225
 226 TEST_F(SdchManagerTest, CanNotUseHTTPSDictionaryOverHTTP) {
 227   std::string dictionary_domain("x.y.z.google.com");
 228   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 229
 230   SdchManager::EnableSecureSchemeSupport(true);
 231   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 232               GURL("https://" + dictionary_domain)));
 233
 234   GURL target_url("http://" + dictionary_domain + "/test");
 235   std::string dictionary_list;
 236   // HTTP target URL should not advertise dictionary acquired over HTTPS even if
 237   // secure scheme support is enabled.
 238   sdch_manager()->GetAvailDictionaryList(target_url, &dictionary_list);
 239   EXPECT_TRUE(dictionary_list.empty());
 240
 241   scoped_refptr<SdchManager::Dictionary> dictionary;
 242   std::string client_hash;
 243   std::string server_hash;
 244   sdch_manager()->GenerateHash(dictionary_text, &client_hash, &server_hash);
 245   sdch_manager()->GetVcdiffDictionary(server_hash, target_url, &dictionary);
 246   EXPECT_TRUE(dictionary == NULL);
 247 }
 248
 249 TEST_F(SdchManagerTest, FailToSetDomainMismatchDictionary) {
 250   std::string dictionary_domain("x.y.z.google.com");
 251   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 252
 253   // Fail the "domain match" requirement.
 254   EXPECT_FALSE(sdch_manager()->AddSdchDictionary(dictionary_text,
 255                GURL("http://y.z.google.com")));
 256 }
 257
 258 TEST_F(SdchManagerTest, FailToSetDotHostPrefixDomainDictionary) {
 259   std::string dictionary_domain("x.y.z.google.com");
 260   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 261
 262   // Fail the HD with D being the domain and H having a dot requirement.
 263   EXPECT_FALSE(sdch_manager()->AddSdchDictionary(dictionary_text,
 264                GURL("http://w.x.y.z.google.com")));
 265 }
 266
 267 TEST_F(SdchManagerTest, FailToSetRepeatPrefixWithDotDictionary) {
 268   // Make sure that a prefix that matches the domain postfix won't confuse
 269   // the validation checks.
 270   std::string dictionary_domain("www.google.com");
 271   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 272
 273   // Fail the HD with D being the domain and H having a dot requirement.
 274   EXPECT_FALSE(sdch_manager()->AddSdchDictionary(dictionary_text,
 275                GURL("http://www.google.com.www.google.com")));
 276 }
 277
 278 TEST_F(SdchManagerTest, CanSetLeadingDotDomainDictionary) {
 279   // Make sure that a prefix that matches the domain postfix won't confuse
 280   // the validation checks.
 281   std::string dictionary_domain(".google.com");
 282   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 283
 284   // Verify that a leading dot in the domain is acceptable, as long as the host
 285   // name does not contain any dots preceding the matched domain name.
 286   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 287                GURL("http://www.google.com")));
 288 }
 289
 290 // Make sure the order of the tests is not helping us or confusing things.
 291 // See test CanSetExactMatchDictionary above for first try.
 292 TEST_F(SdchManagerTest, CanStillSetExactMatchDictionary) {
 293   std::string dictionary_domain("x.y.z.google.com");
 294   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 295
 296   // Perfect match should *STILL* work.
 297   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 298               GURL("http://" + dictionary_domain)));
 299 }
 300
 301 // Make sure the DOS protection precludes the addition of too many dictionaries.
 302 TEST_F(SdchManagerTest, TooManyDictionaries) {
 303   std::string dictionary_domain(".google.com");
 304   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 305
 306   size_t count = 0;
 307   while (count <= SdchManager::kMaxDictionaryCount + 1) {
 308     if (!sdch_manager()->AddSdchDictionary(dictionary_text,
 309                                           GURL("http://www.google.com")))
 310       break;
 311
 312     dictionary_text += " ";  // Create dictionary with different SHA signature.
 313     ++count;
 314   }
 315   EXPECT_EQ(SdchManager::kMaxDictionaryCount, count);
 316 }
 317
 318 TEST_F(SdchManagerTest, DictionaryNotTooLarge) {
 319   std::string dictionary_domain(".google.com");
 320   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 321
 322   dictionary_text.append(
 323       SdchManager::kMaxDictionarySize  - dictionary_text.size(), ' ');
 324   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(dictionary_text,
 325               GURL("http://" + dictionary_domain)));
 326 }
 327
 328 TEST_F(SdchManagerTest, DictionaryTooLarge) {
 329   std::string dictionary_domain(".google.com");
 330   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 331
 332   dictionary_text.append(
 333       SdchManager::kMaxDictionarySize + 1 - dictionary_text.size(), ' ');
 334   EXPECT_FALSE(sdch_manager()->AddSdchDictionary(dictionary_text,
 335               GURL("http://" + dictionary_domain)));
 336 }
 337
 338 TEST_F(SdchManagerTest, PathMatch) {
 339   bool (*PathMatch)(const std::string& path, const std::string& restriction) =
 340       SdchManager::Dictionary::PathMatch;
 341   // Perfect match is supported.
 342   EXPECT_TRUE(PathMatch("/search", "/search"));
 343   EXPECT_TRUE(PathMatch("/search/", "/search/"));
 344
 345   // Prefix only works if last character of restriction is a slash, or first
 346   // character in path after a match is a slash.  Validate each case separately.
 347
 348   // Rely on the slash in the path (not at the end of the restriction).
 349   EXPECT_TRUE(PathMatch("/search/something", "/search"));
 350   EXPECT_TRUE(PathMatch("/search/s", "/search"));
 351   EXPECT_TRUE(PathMatch("/search/other", "/search"));
 352   EXPECT_TRUE(PathMatch("/search/something", "/search"));
 353
 354   // Rely on the slash at the end of the restriction.
 355   EXPECT_TRUE(PathMatch("/search/something", "/search/"));
 356   EXPECT_TRUE(PathMatch("/search/s", "/search/"));
 357   EXPECT_TRUE(PathMatch("/search/other", "/search/"));
 358   EXPECT_TRUE(PathMatch("/search/something", "/search/"));
 359
 360   // Make sure less that sufficient prefix match is false.
 361   EXPECT_FALSE(PathMatch("/sear", "/search"));
 362   EXPECT_FALSE(PathMatch("/", "/search"));
 363   EXPECT_FALSE(PathMatch(std::string(), "/search"));
 364
 365   // Add examples with several levels of direcories in the restriction.
 366   EXPECT_FALSE(PathMatch("/search/something", "search/s"));
 367   EXPECT_FALSE(PathMatch("/search/", "/search/s"));
 368
 369   // Make sure adding characters to path will also fail.
 370   EXPECT_FALSE(PathMatch("/searching", "/search/"));
 371   EXPECT_FALSE(PathMatch("/searching", "/search"));
 372
 373   // Make sure we're case sensitive.
 374   EXPECT_FALSE(PathMatch("/ABC", "/abc"));
 375   EXPECT_FALSE(PathMatch("/abc", "/ABC"));
 376 }
 377
 378 // The following are only applicable while we have a latency test in the code,
 379 // and can be removed when that functionality is stripped.
 380 TEST_F(SdchManagerTest, LatencyTestControls) {
 381   GURL url("http://www.google.com");
 382   GURL url2("http://www.google2.com");
 383
 384   // First make sure we default to false.
 385   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url));
 386   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url2));
 387
 388   // That we can set each to true.
 389   sdch_manager()->SetAllowLatencyExperiment(url, true);
 390   EXPECT_TRUE(sdch_manager()->AllowLatencyExperiment(url));
 391   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url2));
 392
 393   sdch_manager()->SetAllowLatencyExperiment(url2, true);
 394   EXPECT_TRUE(sdch_manager()->AllowLatencyExperiment(url));
 395   EXPECT_TRUE(sdch_manager()->AllowLatencyExperiment(url2));
 396
 397   // And can reset them to false.
 398   sdch_manager()->SetAllowLatencyExperiment(url, false);
 399   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url));
 400   EXPECT_TRUE(sdch_manager()->AllowLatencyExperiment(url2));
 401
 402   sdch_manager()->SetAllowLatencyExperiment(url2, false);
 403   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url));
 404   EXPECT_FALSE(sdch_manager()->AllowLatencyExperiment(url2));
 405 }
 406
 407 TEST_F(SdchManagerTest, CanUseMultipleManagers) {
 408   SdchManager second_manager;
 409
 410   std::string dictionary_domain_1("x.y.z.google.com");
 411   std::string dictionary_domain_2("x.y.z.chromium.org");
 412
 413   std::string dictionary_text_1(NewSdchDictionary(dictionary_domain_1));
 414   std::string dictionary_text_2(NewSdchDictionary(dictionary_domain_2));
 415
 416   std::string tmp_hash;
 417   std::string server_hash_1;
 418   std::string server_hash_2;
 419
 420   SdchManager::GenerateHash(dictionary_text_1, &tmp_hash, &server_hash_1);
 421   SdchManager::GenerateHash(dictionary_text_2, &tmp_hash, &server_hash_2);
 422
 423   // Confirm that if you add directories to one manager, you
 424   // can't get them from the other.
 425   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(
 426       dictionary_text_1, GURL("http://" + dictionary_domain_1)));
 427   scoped_refptr<SdchManager::Dictionary> dictionary;
 428   sdch_manager()->GetVcdiffDictionary(
 429       server_hash_1,
 430       GURL("http://" + dictionary_domain_1 + "/random_url"),
 431       &dictionary);
 432   EXPECT_TRUE(dictionary);
 433
 434   EXPECT_TRUE(second_manager.AddSdchDictionary(
 435       dictionary_text_2, GURL("http://" + dictionary_domain_2)));
 436   second_manager.GetVcdiffDictionary(
 437       server_hash_2,
 438       GURL("http://" + dictionary_domain_2 + "/random_url"),
 439       &dictionary);
 440   EXPECT_TRUE(dictionary);
 441
 442   sdch_manager()->GetVcdiffDictionary(
 443       server_hash_2,
 444       GURL("http://" + dictionary_domain_2 + "/random_url"),
 445       &dictionary);
 446   EXPECT_FALSE(dictionary);
 447
 448   second_manager.GetVcdiffDictionary(
 449       server_hash_1,
 450       GURL("http://" + dictionary_domain_1 + "/random_url"),
 451       &dictionary);
 452   EXPECT_FALSE(dictionary);
 453 }
 454
 455 TEST_F(SdchManagerTest, HttpsCorrectlySupported) {
 456   GURL url("http://www.google.com");
 457   GURL secure_url("https://www.google.com");
 458
 459   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(url));
 460   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(secure_url));
 461
 462   SdchManager::EnableSecureSchemeSupport(true);
 463   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(url));
 464   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(secure_url));
 465 }
 466
 467 TEST_F(SdchManagerTest, ClearDictionaryData) {
 468   std::string dictionary_domain("x.y.z.google.com");
 469   GURL blacklist_url("http://bad.chromium.org");
 470
 471   std::string dictionary_text(NewSdchDictionary(dictionary_domain));
 472   std::string tmp_hash;
 473   std::string server_hash;
 474
 475   SdchManager::GenerateHash(dictionary_text, &tmp_hash, &server_hash);
 476
 477   EXPECT_TRUE(sdch_manager()->AddSdchDictionary(
 478       dictionary_text, GURL("http://" + dictionary_domain)));
 479   scoped_refptr<SdchManager::Dictionary> dictionary;
 480   sdch_manager()->GetVcdiffDictionary(
 481       server_hash,
 482       GURL("http://" + dictionary_domain + "/random_url"),
 483       &dictionary);
 484   EXPECT_TRUE(dictionary);
 485
 486   sdch_manager()->BlacklistDomain(GURL(blacklist_url),
 487                                   SdchManager::MIN_PROBLEM_CODE);
 488   EXPECT_FALSE(sdch_manager()->IsInSupportedDomain(blacklist_url));
 489
 490   sdch_manager()->ClearData();
 491
 492   dictionary = NULL;
 493   sdch_manager()->GetVcdiffDictionary(
 494       server_hash,
 495       GURL("http://" + dictionary_domain + "/random_url"),
 496       &dictionary);
 497   EXPECT_FALSE(dictionary);
 498   EXPECT_TRUE(sdch_manager()->IsInSupportedDomain(blacklist_url));
 499 }
 500
 501 }  // namespace net
 502