media/mtransport/rlogconnector.h
author Tim Huang <tihuang@mozilla.com>
Thu, 31 Aug 2017 11:14:14 +0800
changeset 453921 b2f55468b241f28678dc5e35e19eb3b5781a1c5c
parent 363145 28cab19aa7f1cd9a5801e18b580e2bc46eb4cf24
child 508163 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1222285 - Part 2: Making the keyboard events of modifier keys been suppressed when 'privacy.resistFingerprinting' is true. r=arthuredelstein,masayuki This patch makes 'Shift', 'Alt', 'Contorl' and 'AltGraph' been suppressed for content when fingerprinting resistance is enabled. Chrome can still get these events. The reason behind this is that websites can still observe key combinations to tell which keyboard layout is using even we spoof the keyboardEvent.code, keyboardEvent.keyCode and modifier states. For example, the AZERTY France keyboard, the digit keys of it requires the user press the Shift key. So, it is easy to differentiate AZERTY and QWERTY keyboard by observing whether a Shift key generates its own before the digit keys. There are similar issues for 'Alt' and 'AltGraph' as well. MozReview-Commit-ID: 3CwCgvey4lK

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

// Some of this code is cut-and-pasted from nICEr. Copyright is:

/*
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  contributors may be used to endorse or promote products derived from
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/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

/* Original author: bcampen@mozilla.com */

/*
   This file defines an r_dest_vlog that can be used to accumulate log messages
   for later inspection/filtering. The intent is to use this for interactive
   debug purposes on an about:webrtc page or similar.
*/

#ifndef rlogconnector_h__
#define rlogconnector_h__

#include <stdint.h>

#include <deque>
#include <string>
#include <vector>

#include "mozilla/Mutex.h"

#include "m_cpp_utils.h"

namespace mozilla {

class RLogConnector {
  public:
    /*
       NB: These are not threadsafe, nor are they safe to call during static
       init/deinit.
    */
    static RLogConnector* CreateInstance();
    static RLogConnector* GetInstance();
    static void DestroyInstance();

    /*
       Retrieves log statements that match a given substring, subject to a
       limit. |matching_logs| will be filled in chronological order (front()
       is oldest, back() is newest). |limit| == 0 will be interpreted as no
       limit.
    */
    void Filter(const std::string& substring,
                uint32_t limit,
                std::deque<std::string>* matching_logs);

    void FilterAny(const std::vector<std::string>& substrings,
                   uint32_t limit,
                   std::deque<std::string>* matching_logs);

    inline void GetAny(uint32_t limit,
                       std::deque<std::string>* matching_logs) {
      Filter("", limit, matching_logs);
    }

    void SetLogLimit(uint32_t new_limit);
    void Log(int level, std::string&& log);
    void Clear();

    // Methods to signal when a PeerConnection exists in a Private Window.
    void EnterPrivateMode();
    void ExitPrivateMode();

  private:
    RLogConnector();
    ~RLogConnector();
    void RemoveOld();
    void AddMsg(std::string&& msg);

    static RLogConnector* instance;

    /*
     * Might be worthwhile making this a circular buffer, but I think it is
     * preferable to take up as little space as possible if no logging is
     * happening/the ringbuffer is not being used.
    */
    std::deque<std::string> log_messages_;
    /* Max size of log buffer (should we use time-depth instead/also?) */
    uint32_t log_limit_;
    OffTheBooksMutex mutex_;
    uint32_t disableCount_;

    DISALLOW_COPY_ASSIGN(RLogConnector);
}; // class RLogConnector

} // namespace mozilla

#endif // rlogconnector_h__