[DNR] Implement GetMatchedRules API call (initial functionality)

This CL adds the following functionality:
 - GetMatchedRules API call, to get all rules an extension has matched
 - Ability for extension to specify a tab ID to filter rules in
   GetMatchedRules

Bug: 983761
Change-Id: I3672d84cc23be0e21a1387ede52923c3fe6354ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1913611Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Kelvin Jiang <kelvinjiang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728248}

chrome/browser/extensions/api/declarative_net_request/declarative_net_request_apitest.cc

@@ -70,4 +70,8 @@ IN_PROC_BROWSER_TEST_F(DeclarativeNetRequestAPItest,
   ASSERT_TRUE(RunExtensionTest("on_rules_matched_debug")) << message_;
 }
 
+IN_PROC_BROWSER_TEST_F(DeclarativeNetRequestAPItest, GetMatchedRules) {
+  ASSERT_TRUE(RunExtensionTest("get_matched_rules")) << message_;
+}
+
 }  // namespace

chrome/browser/extensions/extension_action_runner.cc

@@ -541,7 +541,7 @@ void ExtensionActionRunner::DidFinishNavigation(
     int tab_id = ExtensionTabUtil::GetTabId(web_contents());
     declarative_net_request::ActionTracker& action_tracker =
         rules_monitor_service->action_tracker();
-    action_tracker.ResetActionCountForTab(tab_id,
+    action_tracker.ResetTrackedInfoForTab(tab_id,
                                           navigation_handle->GetNavigationId());
   }
 }

chrome/test/data/extensions/api_test/declarative_net_request/get_matched_rules/background.js

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Navigates to |url| and invokes |callback| when the navigation is complete.
+function navigateTab(url, callback) {
+  chrome.tabs.onUpdated.addListener(function updateCallback(_, info, tab) {
+    if (info.status == 'complete' && tab.url == url) {
+      chrome.tabs.onUpdated.removeListener(updateCallback);
+      callback(tab);
+    }
+  });
+
+  chrome.tabs.update({url: url});
+}
+
+var testServerPort;
+function getServerURL(host) {
+  if (!testServerPort)
+    throw new Error('Called getServerURL outside of runTests.');
+  return `http://${host}:${testServerPort}/`;
+}
+
+var tests = [function testGetMatchedRules() {
+  const url = getServerURL('abc.com');
+
+  navigateTab(url, (tab) => {
+    chrome.declarativeNetRequest.getMatchedRules((details) => {
+      chrome.test.assertTrue(!!details.rulesMatchedInfo);
+      const matchedRules = details.rulesMatchedInfo;
+
+      chrome.test.assertEq(1, matchedRules.length);
+      const matchedRule = matchedRules[0];
+
+      // The matched rule's timestamp's cannot be verified, but it should be
+      // populated.
+      chrome.test.assertTrue(matchedRule.hasOwnProperty('timeStamp'));
+      delete matchedRule.timeStamp;
+
+      const expectedRuleInfo = {
+        rule: {ruleId: 1, sourceType: 'manifest'},
+        tabId: tab.id
+      };
+
+      // Sanity check that the RulesMatchedInfo fields are populated
+      // correctly.
+      chrome.test.assertTrue(
+          chrome.test.checkDeepEq(expectedRuleInfo, matchedRule));
+
+      chrome.test.succeed();
+    });
+  });
+}];
+
+chrome.test.getConfig(function(config) {
+  testServerPort = config.testServer.port;
+  chrome.test.runTests(tests);
+});

chrome/test/data/extensions/api_test/declarative_net_request/get_matched_rules/manifest.json

+{
+  "name": "Test extension",
+  "declarative_net_request": {
+    "rule_resources": [
+      "rules.json"
+    ]
+  },
+  "manifest_version": 2,
+  "permissions": [
+    "declarativeNetRequest",
+    "declarativeNetRequestFeedback",
+    "tabs"
+  ],
+  "version": "1.0",
+  "background": {
+    "scripts": [
+      "background.js"
+    ]
+  }
+}

chrome/test/data/extensions/api_test/declarative_net_request/get_matched_rules/rules.json

+[{
+  "id" : 1,
+  "action": { "type" : "block" },
+  "condition" : {"urlFilter" : "abc*", "resourceTypes" : ["main_frame"] }
+}]

extensions/browser/api/declarative_net_request/action_tracker.h

@@ -5,6 +5,7 @@
 #ifndef EXTENSIONS_BROWSER_API_DECLARATIVE_NET_REQUEST_ACTION_TRACKER_H_
 #define EXTENSIONS_BROWSER_API_DECLARATIVE_NET_REQUEST_ACTION_TRACKER_H_
 
+#include <list>
 #include <map>
 #include <vector>
 
@@ -39,11 +40,11 @@ class ActionTracker {
   // called by an extension.
   void OnPreferenceEnabled(const ExtensionId& extension_id) const;
 
-  // Clears the action count for the specified |extension_id| for all tabs.
+  // Clears the TrackedInfo for the specified |extension_id| for all tabs.
   // Called when an extension's ruleset is removed.
   void ClearExtensionData(const ExtensionId& extension_id);
 
-  // Clears the action count for every extension for the specified |tab_id|.
+  // Clears the TrackedInfo for every extension for the specified |tab_id|.
   // Called when the tab has been closed.
   void ClearTabData(int tab_id);
 
@@ -52,8 +53,14 @@ class ActionTracker {
   void ClearPendingNavigation(int64_t navigation_id);
 
   // Called when a main-frame navigation to a different document commits.
-  // Updates the badge count for all extensions for the given |tab_id|.
-  void ResetActionCountForTab(int tab_id, int64_t navigation_id);
+  // Updates the TrackedInfo for all extensions for the given |tab_id|.
+  void ResetTrackedInfoForTab(int tab_id, int64_t navigation_id);
+
+  // Returns all matched rules for |extension_id|. If |tab_id| is provided, only
+  // rules matched for |tab_id| will be returned.
+  std::vector<api::declarative_net_request::MatchedRuleInfo> GetMatchedRules(
+      const ExtensionId& extension_id,
+      base::Optional<int> tab_id) const;
 
  private:
   // Template key type used for TrackedInfo, specified by an extension_id and
@@ -76,9 +83,33 @@ class ActionTracker {
   using ExtensionTabIdKey = TrackedInfoContextKey<int>;
   using ExtensionNavigationIdKey = TrackedInfoContextKey<int64_t>;
 
+  // Represents a matched rule. This is used as a lightweight version of
+  // api::declarative_net_request::MatchedRuleInfo.
+  struct TrackedRule {
+    TrackedRule(int rule_id,
+                api::declarative_net_request::SourceType source_type);
+    TrackedRule(const TrackedRule& other) = delete;
+    TrackedRule& operator=(const TrackedRule& other) = delete;
+
+    const int rule_id;
+    const api::declarative_net_request::SourceType source_type;
+  };
+
   // Info tracked for each ExtensionTabIdKey or ExtensionNavigationIdKey.
   struct TrackedInfo {
+    TrackedInfo();
+    ~TrackedInfo();
+    TrackedInfo(const TrackedInfo& other) = delete;
+    TrackedInfo& operator=(const TrackedInfo& other) = delete;
+    TrackedInfo(TrackedInfo&&);
+    TrackedInfo& operator=(TrackedInfo&&);
+
+    // The number of actions matched. Invalid when the corresponding
+    // TrackedInfoContextKey has a tab_id of -1. Does not include allow rules.
     size_t action_count = 0;
+
+    // The list of rules matched. Includes allow rules.
+    std::list<TrackedRule> matched_rules;
   };
 
   // Called from OnRuleMatched. Dispatches a OnRuleMatchedDebug event to the
@@ -87,14 +118,23 @@ class ActionTracker {
       const RequestAction& request_action,
       api::declarative_net_request::RequestDetails request_details);
 
-  // Maps a pair of (extension ID, tab ID) to the number of actions matched for
-  // the extension and tab specified.
-  std::map<ExtensionTabIdKey, TrackedInfo> actions_matched_;
+  // For all matched rules attributed to |tab_id|, set their tab ID to the
+  // unknown tab ID (-1). Called by ClearTabData and ResetActionCountForTab.
+  void TransferRulesOnTabInvalid(int tab_id);
+
+  // Converts an internally represented |tracked_rule| to a MatchedRuleInfo.
+  api::declarative_net_request::MatchedRuleInfo CreateMatchedRuleInfo(
+      const TrackedRule& tracked_rule,
+      int tab_id) const;
+
+  // Maps a pair of (extension ID, tab ID) to the TrackedInfo for that pair.
+  // TODO(crbug.com/1035106): Prune the rules for the invalid tab ID to prevent
+  // this from growing unbounded.
+  std::map<ExtensionTabIdKey, TrackedInfo> rules_tracked_;
 
-  // Maps a pair of (extension ID, navigation ID) to the number of actions
-  // matched for the main-frame request associated with the navigation ID in the
-  // key. These actions are added to |actions_matched_| once the navigation
-  // commits.
+  // Maps a pair of (extension ID, navigation ID) to the TrackedInfo matched for
+  // the main-frame request associated with the navigation ID in the key. The
+  // TrackedInfo is added to |rules_tracked_| once the navigation commits.
   std::map<ExtensionNavigationIdKey, TrackedInfo> pending_navigation_actions_;
 
   content::BrowserContext* browser_context_;

extensions/browser/api/declarative_net_request/declarative_net_request_api.cc

@@ -8,6 +8,7 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/optional.h"
 #include "base/strings/stringprintf.h"
 #include "base/task/post_task.h"
 #include "base/task_runner_util.h"
@@ -273,7 +274,32 @@ DeclarativeNetRequestGetMatchedRulesFunction::
 
 ExtensionFunction::ResponseAction
 DeclarativeNetRequestGetMatchedRulesFunction::Run() {
-  return RespondNow(NoArguments());
+  using Params = dnr_api::GetMatchedRules::Params;
+
+  base::string16 error;
+  std::unique_ptr<Params> params(Params::Create(*args_, &error));
+  EXTENSION_FUNCTION_VALIDATE(params);
+  EXTENSION_FUNCTION_VALIDATE(error.empty());
+
+  base::Optional<int> tab_id;
+  // TODO(crbug.com/983761): Add timestamp filtering as well.
+
+  if (params->filter && params->filter->tab_id)
+    tab_id = *params->filter->tab_id;
+
+  declarative_net_request::RulesMonitorService* rules_monitor_service =
+      declarative_net_request::RulesMonitorService::Get(browser_context());
+  DCHECK(rules_monitor_service);
+
+  const declarative_net_request::ActionTracker& action_tracker =
+      rules_monitor_service->action_tracker();
+
+  dnr_api::RulesMatchedDetails details;
+  details.rules_matched_info =
+      action_tracker.GetMatchedRules(extension_id(), tab_id);
+
+  return RespondNow(
+      ArgumentList(dnr_api::GetMatchedRules::Results::Create(details)));
 }
 
 DeclarativeNetRequestSetActionCountAsBadgeTextFunction::

extensions/common/api/_api_features.json

@@ -151,7 +151,7 @@
     "contexts": ["blessed_extension"]
   },
   "declarativeNetRequest.getMatchedRules": {
-    "dependencies": ["permission:declarativeNetRequest"],
+    "dependencies": ["permission:declarativeNetRequest", "permission:declarativeNetRequestFeedback"],
     "contexts": ["blessed_extension"],
     "channel": "trunk"
   },