src/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.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/extensions/api/declarative_webrequest/webrequest_rules_registry.h"
   6
   7 #include <algorithm>
   8 #include <limits>
   9 #include <utility>
  10
  11 #include "base/bind.h"
  12 #include "base/stl_util.h"
  13 #include "chrome/browser/extensions/api/declarative_webrequest/webrequest_condition.h"
  14 #include "chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h"
  15 #include "chrome/browser/extensions/api/web_request/web_request_api_helpers.h"
  16 #include "chrome/browser/extensions/api/web_request/web_request_permissions.h"
  17 #include "chrome/browser/profiles/profile.h"
  18 #include "extensions/browser/extension_system.h"
  19 #include "extensions/common/error_utils.h"
  20 #include "extensions/common/extension.h"
  21 #include "extensions/common/permissions/permissions_data.h"
  22 #include "net/url_request/url_request.h"
  23
  24 using url_matcher::URLMatcherConditionSet;
  25
  26 namespace {
  27
  28 const char kActionCannotBeExecuted[] = "The action '*' can never be executed "
  29     "because there are is no time in the request life-cycle during which the "
  30     "conditions can be checked and the action can possibly be executed.";
  31
  32 const char kAllURLsPermissionNeeded[] =
  33     "To execute the action '*', you need to request host permission for all "
  34     "hosts.";
  35
  36 }  // namespace
  37
  38 namespace extensions {
  39
  40 WebRequestRulesRegistry::WebRequestRulesRegistry(
  41     Profile* profile,
  42     RulesCacheDelegate* cache_delegate,
  43     const WebViewKey& webview_key)
  44     : RulesRegistry(profile,
  45                     declarative_webrequest_constants::kOnRequest,
  46                     content::BrowserThread::IO,
  47                     cache_delegate,
  48                     webview_key),
  49       profile_id_(profile) {
  50   if (profile)
  51     extension_info_map_ = ExtensionSystem::Get(profile)->info_map();
  52 }
  53
  54 std::set<const WebRequestRule*> WebRequestRulesRegistry::GetMatches(
  55     const WebRequestData& request_data_without_ids) const {
  56   RuleSet result;
  57
  58   WebRequestDataWithMatchIds request_data(&request_data_without_ids);
  59   request_data.url_match_ids = url_matcher_.MatchURL(
  60       request_data.data->request->url());
  61   request_data.first_party_url_match_ids = url_matcher_.MatchURL(
  62       request_data.data->request->first_party_for_cookies());
  63
  64   // 1st phase -- add all rules with some conditions without UrlFilter
  65   // attributes.
  66   for (RuleSet::const_iterator it = rules_with_untriggered_conditions_.begin();
  67        it != rules_with_untriggered_conditions_.end(); ++it) {
  68     if ((*it)->conditions().IsFulfilled(-1, request_data))
  69       result.insert(*it);
  70   }
  71
  72   // 2nd phase -- add all rules with some conditions triggered by URL matches.
  73   AddTriggeredRules(request_data.url_match_ids, request_data, &result);
  74   AddTriggeredRules(request_data.first_party_url_match_ids,
  75                     request_data, &result);
  76
  77   return result;
  78 }
  79
  80 std::list<LinkedPtrEventResponseDelta> WebRequestRulesRegistry::CreateDeltas(
  81     const InfoMap* extension_info_map,
  82     const WebRequestData& request_data,
  83     bool crosses_incognito) {
  84   if (webrequest_rules_.empty())
  85     return std::list<LinkedPtrEventResponseDelta>();
  86
  87   std::set<const WebRequestRule*> matches = GetMatches(request_data);
  88
  89   // Sort all matching rules by their priority so that they can be processed
  90   // in decreasing order.
  91   typedef std::pair<WebRequestRule::Priority, WebRequestRule::GlobalRuleId>
  92       PriorityRuleIdPair;
  93   std::vector<PriorityRuleIdPair> ordered_matches;
  94   ordered_matches.reserve(matches.size());
  95   for (std::set<const WebRequestRule*>::iterator i = matches.begin();
  96        i != matches.end(); ++i) {
  97     ordered_matches.push_back(make_pair((*i)->priority(), (*i)->id()));
  98   }
  99   // Sort from rbegin to rend in order to get descending priority order.
 100   std::sort(ordered_matches.rbegin(), ordered_matches.rend());
 101
 102   // Build a map that maps each extension id to the minimum required priority
 103   // for rules of that extension. Initially, this priority is -infinite and
 104   // will be increased when the rules are processed and raise the bar via
 105   // WebRequestIgnoreRulesActions.
 106   typedef std::string ExtensionId;
 107   typedef std::map<ExtensionId, WebRequestRule::Priority> MinPriorities;
 108   typedef std::map<ExtensionId, std::set<std::string> > IgnoreTags;
 109   MinPriorities min_priorities;
 110   IgnoreTags ignore_tags;
 111   for (std::vector<PriorityRuleIdPair>::iterator i = ordered_matches.begin();
 112        i != ordered_matches.end(); ++i) {
 113     const WebRequestRule::GlobalRuleId& rule_id = i->second;
 114     const ExtensionId& extension_id = rule_id.first;
 115     min_priorities[extension_id] = std::numeric_limits<int>::min();
 116   }
 117
 118   // Create deltas until we have passed the minimum priority.
 119   std::list<LinkedPtrEventResponseDelta> result;
 120   for (std::vector<PriorityRuleIdPair>::iterator i = ordered_matches.begin();
 121        i != ordered_matches.end(); ++i) {
 122     const WebRequestRule::Priority priority_of_rule = i->first;
 123     const WebRequestRule::GlobalRuleId& rule_id = i->second;
 124     const ExtensionId& extension_id = rule_id.first;
 125     const WebRequestRule* rule =
 126         webrequest_rules_[rule_id.first][rule_id.second].get();
 127     CHECK(rule);
 128
 129     // Skip rule if a previous rule of this extension instructed to ignore
 130     // all rules with a lower priority than min_priorities[extension_id].
 131     int current_min_priority = min_priorities[extension_id];
 132     if (priority_of_rule < current_min_priority)
 133       continue;
 134
 135     if (!rule->tags().empty() && !ignore_tags[extension_id].empty()) {
 136       bool ignore_rule = false;
 137       const WebRequestRule::Tags& tags = rule->tags();
 138       for (WebRequestRule::Tags::const_iterator i = tags.begin();
 139            !ignore_rule && i != tags.end();
 140            ++i) {
 141         ignore_rule |= ContainsKey(ignore_tags[extension_id], *i);
 142       }
 143       if (ignore_rule)
 144         continue;
 145     }
 146
 147     std::list<LinkedPtrEventResponseDelta> rule_result;
 148     WebRequestAction::ApplyInfo apply_info = {
 149       extension_info_map, request_data, crosses_incognito, &rule_result,
 150       &ignore_tags[extension_id]
 151     };
 152     rule->Apply(&apply_info);
 153     result.splice(result.begin(), rule_result);
 154
 155     min_priorities[extension_id] = std::max(current_min_priority,
 156                                             rule->GetMinimumPriority());
 157   }
 158   return result;
 159 }
 160
 161 std::string WebRequestRulesRegistry::AddRulesImpl(
 162     const std::string& extension_id,
 163     const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) {
 164   typedef std::pair<WebRequestRule::RuleId, linked_ptr<WebRequestRule> >
 165       IdRulePair;
 166   typedef std::vector<IdRulePair> RulesVector;
 167
 168   base::Time extension_installation_time =
 169       GetExtensionInstallationTime(extension_id);
 170
 171   std::string error;
 172   RulesVector new_webrequest_rules;
 173   new_webrequest_rules.reserve(rules.size());
 174   const Extension* extension =
 175       extension_info_map_->extensions().GetByID(extension_id);
 176   RulesMap& registered_rules = webrequest_rules_[extension_id];
 177
 178   for (std::vector<linked_ptr<RulesRegistry::Rule> >::const_iterator rule =
 179        rules.begin(); rule != rules.end(); ++rule) {
 180     const WebRequestRule::RuleId& rule_id(*(*rule)->id);
 181     DCHECK(registered_rules.find(rule_id) == registered_rules.end());
 182
 183     scoped_ptr<WebRequestRule> webrequest_rule(WebRequestRule::Create(
 184         url_matcher_.condition_factory(),
 185         extension, extension_installation_time, *rule,
 186         base::Bind(&Checker, base::Unretained(extension)),
 187         &error));
 188     if (!error.empty()) {
 189       // We don't return here, because we want to clear temporary
 190       // condition sets in the url_matcher_.
 191       break;
 192     }
 193
 194     new_webrequest_rules.push_back(
 195         IdRulePair(rule_id, make_linked_ptr(webrequest_rule.release())));
 196   }
 197
 198   if (!error.empty()) {
 199     // Clean up temporary condition sets created during rule creation.
 200     url_matcher_.ClearUnusedConditionSets();
 201     return error;
 202   }
 203
 204   // Wohoo, everything worked fine.
 205   registered_rules.insert(new_webrequest_rules.begin(),
 206                           new_webrequest_rules.end());
 207
 208   // Create the triggers.
 209   for (RulesVector::const_iterator i = new_webrequest_rules.begin();
 210        i != new_webrequest_rules.end(); ++i) {
 211     URLMatcherConditionSet::Vector url_condition_sets;
 212     const WebRequestConditionSet& conditions = i->second->conditions();
 213     conditions.GetURLMatcherConditionSets(&url_condition_sets);
 214     for (URLMatcherConditionSet::Vector::iterator j =
 215          url_condition_sets.begin(); j != url_condition_sets.end(); ++j) {
 216       rule_triggers_[(*j)->id()] = i->second.get();
 217     }
 218   }
 219
 220   // Register url patterns in |url_matcher_| and
 221   // |rules_with_untriggered_conditions_|.
 222   URLMatcherConditionSet::Vector all_new_condition_sets;
 223   for (RulesVector::const_iterator i = new_webrequest_rules.begin();
 224        i != new_webrequest_rules.end(); ++i) {
 225     i->second->conditions().GetURLMatcherConditionSets(&all_new_condition_sets);
 226     if (i->second->conditions().HasConditionsWithoutUrls())
 227       rules_with_untriggered_conditions_.insert(i->second.get());
 228   }
 229   url_matcher_.AddConditionSets(all_new_condition_sets);
 230
 231   ClearCacheOnNavigation();
 232
 233   if (profile_id_ && !registered_rules.empty()) {
 234     content::BrowserThread::PostTask(
 235         content::BrowserThread::UI, FROM_HERE,
 236         base::Bind(&extension_web_request_api_helpers::NotifyWebRequestAPIUsed,
 237                    profile_id_, make_scoped_refptr(extension)));
 238   }
 239
 240   return std::string();
 241 }
 242
 243 std::string WebRequestRulesRegistry::RemoveRulesImpl(
 244     const std::string& extension_id,
 245     const std::vector<std::string>& rule_identifiers) {
 246   // URLMatcherConditionSet IDs that can be removed from URLMatcher.
 247   std::vector<URLMatcherConditionSet::ID> remove_from_url_matcher;
 248   RulesMap& registered_rules = webrequest_rules_[extension_id];
 249
 250   for (std::vector<std::string>::const_iterator i = rule_identifiers.begin();
 251        i != rule_identifiers.end(); ++i) {
 252     // Skip unknown rules.
 253     RulesMap::iterator webrequest_rules_entry = registered_rules.find(*i);
 254     if (webrequest_rules_entry == registered_rules.end())
 255       continue;
 256
 257     // Remove all triggers but collect their IDs.
 258     CleanUpAfterRule(webrequest_rules_entry->second.get(),
 259                      &remove_from_url_matcher);
 260
 261     // Removes the owning references to (and thus deletes) the rule.
 262     registered_rules.erase(webrequest_rules_entry);
 263   }
 264   if (registered_rules.empty())
 265     webrequest_rules_.erase(extension_id);
 266
 267   // Clear URLMatcher based on condition_set_ids that are not needed any more.
 268   url_matcher_.RemoveConditionSets(remove_from_url_matcher);
 269
 270   ClearCacheOnNavigation();
 271
 272   return std::string();
 273 }
 274
 275 std::string WebRequestRulesRegistry::RemoveAllRulesImpl(
 276     const std::string& extension_id) {
 277   // First we get out all URLMatcherConditionSets and remove the rule references
 278   // from |rules_with_untriggered_conditions_|.
 279   std::vector<URLMatcherConditionSet::ID> remove_from_url_matcher;
 280   for (RulesMap::const_iterator it = webrequest_rules_[extension_id].begin();
 281        it != webrequest_rules_[extension_id].end();
 282        ++it) {
 283     CleanUpAfterRule(it->second.get(), &remove_from_url_matcher);
 284   }
 285   url_matcher_.RemoveConditionSets(remove_from_url_matcher);
 286
 287   webrequest_rules_.erase(extension_id);
 288   ClearCacheOnNavigation();
 289   return std::string();
 290 }
 291
 292 void WebRequestRulesRegistry::CleanUpAfterRule(
 293     const WebRequestRule* rule,
 294     std::vector<URLMatcherConditionSet::ID>* remove_from_url_matcher) {
 295   URLMatcherConditionSet::Vector condition_sets;
 296   rule->conditions().GetURLMatcherConditionSets(&condition_sets);
 297   for (URLMatcherConditionSet::Vector::iterator j = condition_sets.begin();
 298        j != condition_sets.end();
 299        ++j) {
 300     remove_from_url_matcher->push_back((*j)->id());
 301     rule_triggers_.erase((*j)->id());
 302   }
 303   rules_with_untriggered_conditions_.erase(rule);
 304 }
 305
 306 bool WebRequestRulesRegistry::IsEmpty() const {
 307   // Easy first.
 308   if (!rule_triggers_.empty() && url_matcher_.IsEmpty())
 309     return false;
 310
 311   // Now all the registered rules for each extensions.
 312   for (std::map<WebRequestRule::ExtensionId, RulesMap>::const_iterator it =
 313            webrequest_rules_.begin();
 314        it != webrequest_rules_.end();
 315        ++it) {
 316     if (!it->second.empty())
 317       return false;
 318   }
 319   return true;
 320 }
 321
 322 WebRequestRulesRegistry::~WebRequestRulesRegistry() {}
 323
 324 base::Time WebRequestRulesRegistry::GetExtensionInstallationTime(
 325     const std::string& extension_id) const {
 326   return extension_info_map_->GetInstallTime(extension_id);
 327 }
 328
 329 void WebRequestRulesRegistry::ClearCacheOnNavigation() {
 330   extension_web_request_api_helpers::ClearCacheOnNavigation();
 331 }
 332
 333 // static
 334 bool WebRequestRulesRegistry::Checker(const Extension* extension,
 335                                       const WebRequestConditionSet* conditions,
 336                                       const WebRequestActionSet* actions,
 337                                       std::string* error) {
 338   return (StageChecker(conditions, actions, error) &&
 339           HostPermissionsChecker(extension, actions, error));
 340 }
 341
 342 // static
 343 bool WebRequestRulesRegistry::HostPermissionsChecker(
 344     const Extension* extension,
 345     const WebRequestActionSet* actions,
 346     std::string* error) {
 347   if (extension->permissions_data()->HasEffectiveAccessToAllHosts())
 348     return true;
 349
 350   // Without the permission for all URLs, actions with the STRATEGY_DEFAULT
 351   // should not be registered, they would never be able to execute.
 352   for (WebRequestActionSet::Actions::const_iterator action_iter =
 353            actions->actions().begin();
 354        action_iter != actions->actions().end();
 355        ++action_iter) {
 356     if ((*action_iter)->host_permissions_strategy() ==
 357         WebRequestAction::STRATEGY_DEFAULT) {
 358       *error = ErrorUtils::FormatErrorMessage(kAllURLsPermissionNeeded,
 359                                               (*action_iter)->GetName());
 360       return false;
 361     }
 362   }
 363   return true;
 364 }
 365
 366 // static
 367 bool WebRequestRulesRegistry::StageChecker(
 368     const WebRequestConditionSet* conditions,
 369     const WebRequestActionSet* actions,
 370     std::string* error) {
 371   // Actions and conditions can be checked and executed in specific stages
 372   // of each web request. A rule is inconsistent if there is an action that
 373   // can only be triggered in stages in which no condition can be evaluated.
 374
 375   // In which stages there are conditions to evaluate.
 376   int condition_stages = 0;
 377   for (WebRequestConditionSet::Conditions::const_iterator condition_iter =
 378            conditions->conditions().begin();
 379        condition_iter != conditions->conditions().end();
 380        ++condition_iter) {
 381     condition_stages |= (*condition_iter)->stages();
 382   }
 383
 384   for (WebRequestActionSet::Actions::const_iterator action_iter =
 385            actions->actions().begin();
 386        action_iter != actions->actions().end();
 387        ++action_iter) {
 388     // Test the intersection of bit masks, this is intentionally & and not &&.
 389     if ((*action_iter)->stages() & condition_stages)
 390       continue;
 391     // We only get here if no matching condition was found.
 392     *error = ErrorUtils::FormatErrorMessage(kActionCannotBeExecuted,
 393                                             (*action_iter)->GetName());
 394     return false;
 395   }
 396   return true;
 397 }
 398 void WebRequestRulesRegistry::AddTriggeredRules(
 399     const URLMatches& url_matches,
 400     const WebRequestCondition::MatchData& request_data,
 401     RuleSet* result) const {
 402   for (URLMatches::const_iterator url_match = url_matches.begin();
 403        url_match != url_matches.end(); ++url_match) {
 404     RuleTriggers::const_iterator rule_trigger = rule_triggers_.find(*url_match);
 405     CHECK(rule_trigger != rule_triggers_.end());
 406     if (!ContainsKey(*result, rule_trigger->second) &&
 407         rule_trigger->second->conditions().IsFulfilled(*url_match,
 408                                                        request_data))
 409       result->insert(rule_trigger->second);
 410   }
 411 }
 412
 413 }  // namespace extensions