chrome/browser/media/desktop_streams_registry.cc

   1 // Copyright 2013 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/media/desktop_streams_registry.h"
   6
   7 #include "base/base64.h"
   8 #include "base/location.h"
   9 #include "base/time/time.h"
  10 #include "content/public/browser/browser_thread.h"
  11 #include "crypto/random.h"
  12
  13 namespace {
  14
  15 const int kStreamIdLengthBytes = 16;
  16
  17 const int kApprovedStreamTimeToLiveSeconds = 10;
  18
  19 std::string GenerateRandomStreamId() {
  20   char buffer[kStreamIdLengthBytes];
  21   crypto::RandBytes(buffer, arraysize(buffer));
  22   std::string result;
  23   base::Base64Encode(base::StringPiece(buffer, arraysize(buffer)),
  24                      &result);
  25   return result;
  26 }
  27
  28 }  // namespace
  29
  30 DesktopStreamsRegistry::DesktopStreamsRegistry() {}
  31 DesktopStreamsRegistry::~DesktopStreamsRegistry() {}
  32
  33 std::string DesktopStreamsRegistry::RegisterStream(
  34     int render_process_id,
  35     int render_frame_id,
  36     const GURL& origin,
  37     const content::DesktopMediaID& source,
  38     const std::string& extension_name) {
  39   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  40
  41   std::string id = GenerateRandomStreamId();
  42   DCHECK(approved_streams_.find(id) == approved_streams_.end());
  43   ApprovedDesktopMediaStream& stream = approved_streams_[id];
  44   stream.render_process_id = render_process_id;
  45   stream.render_frame_id = render_frame_id;
  46   stream.origin = origin;
  47   stream.source = source;
  48   stream.extension_name = extension_name;
  49
  50   content::BrowserThread::PostDelayedTask(
  51       content::BrowserThread::UI, FROM_HERE,
  52       base::Bind(&DesktopStreamsRegistry::CleanupStream,
  53                  base::Unretained(this), id),
  54       base::TimeDelta::FromSeconds(kApprovedStreamTimeToLiveSeconds));
  55
  56   return id;
  57 }
  58
  59 content::DesktopMediaID DesktopStreamsRegistry::RequestMediaForStreamId(
  60     const std::string& id,
  61     int render_process_id,
  62     int render_frame_id,
  63     const GURL& origin,
  64     std::string* extension_name) {
  65   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  66
  67   StreamsMap::iterator it = approved_streams_.find(id);
  68
  69   // Verify that if there is a request with the specified ID it was created for
  70   // the same origin and the same renderer.
  71   if (it == approved_streams_.end() ||
  72       render_process_id != it->second.render_process_id ||
  73       render_frame_id != it->second.render_frame_id ||
  74       origin != it->second.origin) {
  75     return content::DesktopMediaID();
  76   }
  77
  78   content::DesktopMediaID result = it->second.source;
  79   *extension_name = it->second.extension_name;
  80   approved_streams_.erase(it);
  81   return result;
  82 }
  83
  84 void DesktopStreamsRegistry::CleanupStream(const std::string& id) {
  85   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  86   approved_streams_.erase(id);
  87 }
  88
  89 DesktopStreamsRegistry::ApprovedDesktopMediaStream::ApprovedDesktopMediaStream()
  90     : render_process_id(-1), render_frame_id(-1) {}