src/remoting/host/heartbeat_sender.h

   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 #ifndef REMOTING_HOST_HEARTBEAT_SENDER_H_
   6 #define REMOTING_HOST_HEARTBEAT_SENDER_H_
   7
   8 #include <string>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/gtest_prod_util.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/timer/timer.h"
  15 #include "remoting/base/rsa_key_pair.h"
  16 #include "remoting/signaling/signal_strategy.h"
  17
  18 namespace base {
  19 class MessageLoopProxy;
  20 }  // namespace base
  21
  22 namespace buzz {
  23 class XmlElement;
  24 }  // namespace buzz
  25
  26 namespace remoting {
  27
  28 class RsaKeyPair;
  29 class IqRequest;
  30 class IqSender;
  31
  32 // HeartbeatSender periodically sends heartbeat stanzas to the Chromoting Bot.
  33 // Each heartbeat stanza looks as follows:
  34 //
  35 // <iq type="set" to="remoting@bot.talk.google.com"
  36 //     from="user@gmail.com/chromoting123123" id="5" xmlns="jabber:client">
  37 //   <rem:heartbeat rem:hostid="a1ddb11e-8aef-11df-bccf-18a905b9cb5a"
  38 //                  rem:sequence-id="456"
  39 //                  xmlns:rem="google:remoting">
  40 //     <rem:signature>.signature.</rem:signature>
  41 //   </rem:heartbeat>
  42 // </iq>
  43 //
  44 // The sequence-id attribute of the heartbeat is a zero-based incrementally
  45 // increasing integer unique to each heartbeat from a single host.
  46 // The Bot checks the value, and if it is incorrect, includes the
  47 // correct value in the result stanza. The host should then send another
  48 // heartbeat, with the correct sequence-id, and increment the sequence-id in
  49 // susbequent heartbeats.
  50 // The signature is a base-64 encoded SHA-1 hash, signed with the host's
  51 // private RSA key. The message being signed is the full Jid concatenated with
  52 // the sequence-id, separated by one space. For example, for the heartbeat
  53 // stanza above, the message that is signed is
  54 // "user@gmail.com/chromoting123123 456".
  55 //
  56 // The Bot sends the following result stanza in response to each successful
  57 // heartbeat:
  58 //
  59 //  <iq type="set" from="remoting@bot.talk.google.com"
  60 //      to="user@gmail.com/chromoting123123" id="5" xmlns="jabber:client">
  61 //    <rem:heartbeat-result xmlns:rem="google:remoting">
  62 //      <rem:set-interval>300</rem:set-interval>
  63 //    </rem:heartbeat-result>
  64 //  </iq>
  65 //
  66 // The set-interval tag is used to specify desired heartbeat interval
  67 // in seconds. The heartbeat-result and the set-interval tags are
  68 // optional. Host uses default heartbeat interval if it doesn't find
  69 // set-interval tag in the result Iq stanza it receives from the
  70 // server.
  71 // If the heartbeat's sequence-id was incorrect, the Bot sends a result
  72 // stanza of this form:
  73 //
  74 //  <iq type="set" from="remoting@bot.talk.google.com"
  75 //      to="user@gmail.com/chromoting123123" id="5" xmlns="jabber:client">
  76 //    <rem:heartbeat-result xmlns:rem="google:remoting">
  77 //      <rem:expected-sequence-id>654</rem:expected-sequence-id>
  78 //    </rem:heartbeat-result>
  79 //  </iq>
  80 class HeartbeatSender : public SignalStrategy::Listener {
  81  public:
  82   class Listener {
  83    public:
  84     virtual ~Listener() { }
  85
  86     // Invoked after the first successful heartbeat.
  87     virtual void OnHeartbeatSuccessful() = 0;
  88
  89     // Invoked when the host ID is permanently not recognized by the server.
  90     virtual void OnUnknownHostIdError() = 0;
  91   };
  92
  93   // |signal_strategy| and |delegate| must outlive this
  94   // object. Heartbeats will start when the supplied SignalStrategy
  95   // enters the CONNECTED state.
  96   HeartbeatSender(Listener* listener,
  97                   const std::string& host_id,
  98                   SignalStrategy* signal_strategy,
  99                   scoped_refptr<RsaKeyPair> key_pair,
 100                   const std::string& directory_bot_jid);
 101   ~HeartbeatSender() override;
 102
 103   // SignalStrategy::Listener interface.
 104   void OnSignalStrategyStateChange(SignalStrategy::State state) override;
 105   bool OnSignalStrategyIncomingStanza(const buzz::XmlElement* stanza) override;
 106
 107  private:
 108   FRIEND_TEST_ALL_PREFIXES(HeartbeatSenderTest, DoSendStanza);
 109   FRIEND_TEST_ALL_PREFIXES(HeartbeatSenderTest,
 110                            DoSendStanzaWithExpectedSequenceId);
 111   FRIEND_TEST_ALL_PREFIXES(HeartbeatSenderTest, CreateHeartbeatMessage);
 112   FRIEND_TEST_ALL_PREFIXES(HeartbeatSenderTest, ProcessResponseSetInterval);
 113   FRIEND_TEST_ALL_PREFIXES(HeartbeatSenderTest,
 114                            ProcessResponseExpectedSequenceId);
 115
 116   void SendStanza();
 117   void ResendStanza();
 118   void DoSendStanza();
 119   void ProcessResponse(IqRequest* request, const buzz::XmlElement* response);
 120   void SetInterval(int interval);
 121   void SetSequenceId(int sequence_id);
 122
 123   // Helper methods used by DoSendStanza() to generate heartbeat stanzas.
 124   scoped_ptr<buzz::XmlElement> CreateHeartbeatMessage();
 125   scoped_ptr<buzz::XmlElement> CreateSignature();
 126
 127   Listener* listener_;
 128   std::string host_id_;
 129   SignalStrategy* signal_strategy_;
 130   scoped_refptr<RsaKeyPair> key_pair_;
 131   std::string directory_bot_jid_;
 132   scoped_ptr<IqSender> iq_sender_;
 133   scoped_ptr<IqRequest> request_;
 134   int interval_ms_;
 135   base::RepeatingTimer<HeartbeatSender> timer_;
 136   base::OneShotTimer<HeartbeatSender> timer_resend_;
 137   int sequence_id_;
 138   bool sequence_id_was_set_;
 139   int sequence_id_recent_set_num_;
 140   bool heartbeat_succeeded_;
 141   int failed_startup_heartbeat_count_;
 142
 143   DISALLOW_COPY_AND_ASSIGN(HeartbeatSender);
 144 };
 145
 146 }  // namespace remoting
 147
 148 #endif  // REMOTING_HOST_HEARTBEAT_SENDER_H_