remoting/host/dns_blackhole_checker.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 "remoting/host/dns_blackhole_checker.h"
   6
   7 #include "base/callback_helpers.h"
   8 #include "net/url_request/url_fetcher.h"
   9 #include "net/url_request/url_request_context_getter.h"
  10 #include "remoting/base/logging.h"
  11 #include "url/gurl.h"
  12
  13 namespace remoting {
  14
  15 // Default prefix added to the base talkgadget URL.
  16 const char kDefaultHostTalkGadgetPrefix[] = "chromoting-host";
  17
  18 // The base talkgadget URL.
  19 const char kTalkGadgetUrl[] = ".talkgadget.google.com/talkgadget/"
  20                               "oauth/chrome-remote-desktop-host";
  21
  22 DnsBlackholeChecker::DnsBlackholeChecker(
  23     const scoped_refptr<net::URLRequestContextGetter>& request_context_getter,
  24     std::string talkgadget_prefix)
  25     : url_request_context_getter_(request_context_getter),
  26       talkgadget_prefix_(talkgadget_prefix) {
  27 }
  28
  29 DnsBlackholeChecker::~DnsBlackholeChecker() {
  30 }
  31
  32 // This is called in response to the TalkGadget http request initiated from
  33 // CheckStatus().
  34 void DnsBlackholeChecker::OnURLFetchComplete(const net::URLFetcher* source) {
  35   int response = source->GetResponseCode();
  36   bool allow = false;
  37   if (source->GetResponseCode() == 200) {
  38     HOST_LOG << "Successfully connected to host talkgadget.";
  39     allow = true;
  40   } else {
  41     HOST_LOG << "Unable to connect to host talkgadget (" << response << ")";
  42   }
  43   url_fetcher_.reset(nullptr);
  44   base::ResetAndReturn(&callback_).Run(allow);
  45 }
  46
  47 void DnsBlackholeChecker::CheckForDnsBlackhole(
  48     const base::Callback<void(bool)>& callback) {
  49   // Make sure we're not currently in the middle of a connection check.
  50   if (!url_fetcher_.get()) {
  51     DCHECK(callback_.is_null());
  52     callback_ = callback;
  53     std::string talkgadget_url("https://");
  54     if (talkgadget_prefix_.empty()) {
  55       talkgadget_url += kDefaultHostTalkGadgetPrefix;
  56     } else {
  57       talkgadget_url += talkgadget_prefix_;
  58     }
  59     talkgadget_url += kTalkGadgetUrl;
  60     HOST_LOG << "Verifying connection to " << talkgadget_url;
  61     url_fetcher_ = net::URLFetcher::Create(GURL(talkgadget_url),
  62                                            net::URLFetcher::GET, this);
  63     url_fetcher_->SetRequestContext(url_request_context_getter_.get());
  64     url_fetcher_->Start();
  65   } else {
  66     HOST_LOG << "Pending connection check";
  67   }
  68 }
  69
  70 }  // namespace remoting