Add backup URL support for SafeBrowsing data requests.

chrome/browser/safe_browsing/protocol_manager.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_MANAGER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_MANAGER_H_
 
 // A class that implements Chrome's interface with the SafeBrowsing protocol.
 // See https://developers.google.com/safe-browsing/developers_guide_v2 for
 // protocol details.
@@ skipping 162 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SafeBrowsingProtocolManagerTest, TestUpdateUrl);
   friend class SafeBrowsingServerTest;
   friend class SBProtocolManagerFactoryImpl;
 
   // Internal API for fetching information from the SafeBrowsing servers. The
   // GetHash requests are higher priority since they can block user requests
   // so are handled separately.
   enum SafeBrowsingRequestType {
     NO_REQUEST = 0,     // No requests in progress
     UPDATE_REQUEST,     // Request for redirect URLs
+    BACKUP_UPDATE_REQUEST, // Request for redirect URLs to a backup URL.
     CHUNK_REQUEST,      // Request for a specific chunk
   };
 
+  // Which type of backup update request is being used.
+  enum BackupUpdateReason {
+    BACKUP_UPDATE_REASON_CONNECT,
+    BACKUP_UPDATE_REASON_HTTP,
+    BACKUP_UPDATE_REASON_NETWORK,
+    BACKUP_UPDATE_REASON_MAX,
+  };
+
   // Generates Update URL for querying about the latest set of chunk updates.
   GURL UpdateUrl() const;
+
+  // Generates backup Update URL for querying about the latest set of chunk
+  // updates. |url_prefix| is the base prefix to use.
+  GURL BackupUpdateUrl(BackupUpdateReason reason) const;
+
   // Generates GetHash request URL for retrieving full hashes.
   GURL GetHashUrl() const;
   // Generates URL for reporting safe browsing hits for UMA users.
 
   // Composes a ChunkUrl based on input string.
   GURL NextChunkUrl(const std::string& input) const;
 
   // Returns the time for the next update request. If |back_off| is true,
   // the time returned will increment an error count and return the appriate
   // next time (see ScheduleNextUpdate below).
@@ skipping 12 matching lines @@
   // ForceScheduleNextUpdate has to be called to trigger the update.
   void ScheduleNextUpdate(bool back_off);
 
   // Sends a request for a list of chunks we should download to the SafeBrowsing
   // servers. In order to format this request, we need to send all the chunk
   // numbers for each list that we have to the server. Getting the chunk numbers
   // requires a database query (run on the database thread), and the request
   // is sent upon completion of that query in OnGetChunksComplete.
   void IssueUpdateRequest();
 
+  // Sends a backup request for a list of chunks to download, when the primary
+  // update request failed. |reason| specifies why the backup is needed. Unlike
+  // the primary IssueUpdateRequest, this does not need to hit the local
+  // SafeBrowsing database since the existing chunk numbers are remembered from
+  // the primary update request.
+  void IssueBackupUpdateRequest(BackupUpdateReason reason);
+
   // Sends a request for a chunk to the SafeBrowsing servers.
   void IssueChunkRequest();
 
   // Formats a string returned from the database into:
   //   "list_name;a:<add_chunk_ranges>:s:<sub_chunk_ranges>\n"
   static std::string FormatList(const SBListChunkRanges& list);
 
   // Runs the protocol parser on received data and update the
   // SafeBrowsingService with the new content. Returns 'true' on successful
   // parse, 'false' on error.
@@ skipping 102 matching lines @@
   // A string that is appended to the end of URLs for download, gethash,
   // safebrowsing hits and chunk update requests.
   std::string additional_query_;
 
   // The context we use to issue network requests.
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
 
   // URL prefix where browser fetches safebrowsing chunk updates, and hashes.
   std::string url_prefix_;
 
+  // Backup URL prefixes for updates.
+  std::string backup_url_prefixes_[BACKUP_UPDATE_REASON_MAX];
+
+  // The current reason why the backup update request is happening.
+  BackupUpdateReason backup_update_reason_;
+
+  // Data to POST when doing an update.
+  std::string update_list_data_;
+
   // When true, protocol manager will not start an update unless
   // ForceScheduleNextUpdate() is called. This is set for testing purpose.
   bool disable_auto_update_;
 
   // ID for URLFetchers for testing.
   int url_fetcher_id_;
 
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingProtocolManager);
 };
 
@@ skipping 40 matching lines @@
   // call at a later time.
   virtual void AddChunks(const std::string& list, SBChunkList* chunks,
                          AddChunksCallback callback) = 0;
 
   // Delete chunks from the database.
   virtual void DeleteChunks(
       std::vector<SBChunkDelete>* delete_chunks) = 0;
 };
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_MANAGER_H_