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      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_CHROMOTING_HOST_H_
      6 #define REMOTING_HOST_CHROMOTING_HOST_H_
      7 
      8 #include <list>
      9 #include <string>
     10 
     11 #include "base/memory/scoped_ptr.h"
     12 #include "base/memory/ref_counted.h"
     13 #include "base/memory/weak_ptr.h"
     14 #include "base/observer_list.h"
     15 #include "base/threading/non_thread_safe.h"
     16 #include "base/threading/thread.h"
     17 #include "net/base/backoff_entry.h"
     18 #include "remoting/host/client_session.h"
     19 #include "remoting/host/host_status_monitor.h"
     20 #include "remoting/host/host_status_observer.h"
     21 #include "remoting/protocol/authenticator.h"
     22 #include "remoting/protocol/connection_to_client.h"
     23 #include "remoting/protocol/pairing_registry.h"
     24 #include "remoting/protocol/session_manager.h"
     25 
     26 namespace base {
     27 class SingleThreadTaskRunner;
     28 }  // namespace base
     29 
     30 namespace remoting {
     31 
     32 namespace protocol {
     33 class InputStub;
     34 class SessionConfig;
     35 class CandidateSessionConfig;
     36 }  // namespace protocol
     37 
     38 class DesktopEnvironmentFactory;
     39 
     40 // A class to implement the functionality of a host process.
     41 //
     42 // Here's the work flow of this class:
     43 // 1. We should load the saved GAIA ID token or if this is the first
     44 //    time the host process runs we should prompt user for the
     45 //    credential. We will use this token or credentials to authenicate
     46 //    and register the host.
     47 //
     48 // 2. We listen for incoming connection using libjingle. We will create
     49 //    a ConnectionToClient object that wraps around linjingle for transport.
     50 //    A VideoScheduler is created with an Encoder and a webrtc::ScreenCapturer.
     51 //    A ConnectionToClient is added to the ScreenRecorder for transporting
     52 //    the screen captures. An InputStub is created and registered with the
     53 //    ConnectionToClient to receive mouse / keyboard events from the remote
     54 //    client.
     55 //    After we have done all the initialization we'll start the ScreenRecorder.
     56 //    We'll then enter the running state of the host process.
     57 //
     58 // 3. When the user is disconnected, we will pause the ScreenRecorder
     59 //    and try to terminate the threads we have created. This will allow
     60 //    all pending tasks to complete. After all of that completed we
     61 //    return to the idle state. We then go to step (2) if there a new
     62 //    incoming connection.
     63 class ChromotingHost : public base::NonThreadSafe,
     64                        public ClientSession::EventHandler,
     65                        public protocol::SessionManager::Listener,
     66                        public HostStatusMonitor {
     67  public:
     68   // Both |signal_strategy| and |desktop_environment_factory| should outlive
     69   // this object.
     70   ChromotingHost(
     71       SignalStrategy* signal_strategy,
     72       DesktopEnvironmentFactory* desktop_environment_factory,
     73       scoped_ptr<protocol::SessionManager> session_manager,
     74       scoped_refptr<base::SingleThreadTaskRunner> audio_task_runner,
     75       scoped_refptr<base::SingleThreadTaskRunner> input_task_runner,
     76       scoped_refptr<base::SingleThreadTaskRunner> video_capture_task_runner,
     77       scoped_refptr<base::SingleThreadTaskRunner> video_encode_task_runner,
     78       scoped_refptr<base::SingleThreadTaskRunner> network_task_runner,
     79       scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
     80   virtual ~ChromotingHost();
     81 
     82   // Asynchronously starts the host.
     83   //
     84   // After this is invoked, the host process will connect to the talk
     85   // network and start listening for incoming connections.
     86   //
     87   // This method can only be called once during the lifetime of this object.
     88   void Start(const std::string& host_owner);
     89 
     90   // HostStatusMonitor interface.
     91   virtual void AddStatusObserver(HostStatusObserver* observer) OVERRIDE;
     92   virtual void RemoveStatusObserver(HostStatusObserver* observer) OVERRIDE;
     93 
     94   // This method may be called only from
     95   // HostStatusObserver::OnClientAuthenticated() to reject the new
     96   // client.
     97   void RejectAuthenticatingClient();
     98 
     99   // Sets the authenticator factory to use for incoming
    100   // connections. Incoming connections are rejected until
    101   // authenticator factory is set. Must be called on the network
    102   // thread after the host is started. Must not be called more than
    103   // once per host instance because it may not be safe to delete
    104   // factory before all authenticators it created are deleted.
    105   void SetAuthenticatorFactory(
    106       scoped_ptr<protocol::AuthenticatorFactory> authenticator_factory);
    107 
    108   // Enables/disables curtaining when one or more clients are connected.
    109   // Takes immediate effect if clients are already connected.
    110   void SetEnableCurtaining(bool enable);
    111 
    112   // Sets the maximum duration of any session. By default, a session has no
    113   // maximum duration.
    114   void SetMaximumSessionDuration(const base::TimeDelta& max_session_duration);
    115 
    116   ////////////////////////////////////////////////////////////////////////////
    117   // ClientSession::EventHandler implementation.
    118   virtual bool OnSessionAuthenticated(ClientSession* client) OVERRIDE;
    119   virtual void OnSessionChannelsConnected(ClientSession* client) OVERRIDE;
    120   virtual void OnSessionAuthenticationFailed(ClientSession* client) OVERRIDE;
    121   virtual void OnSessionClosed(ClientSession* session) OVERRIDE;
    122   virtual void OnSessionSequenceNumber(ClientSession* session,
    123                                        int64 sequence_number) OVERRIDE;
    124   virtual void OnSessionRouteChange(
    125       ClientSession* session,
    126       const std::string& channel_name,
    127       const protocol::TransportRoute& route) OVERRIDE;
    128 
    129   // SessionManager::Listener implementation.
    130   virtual void OnSessionManagerReady() OVERRIDE;
    131   virtual void OnIncomingSession(
    132       protocol::Session* session,
    133       protocol::SessionManager::IncomingSessionResponse* response) OVERRIDE;
    134 
    135   // Sets desired configuration for the protocol. Must be called before Start().
    136   void set_protocol_config(scoped_ptr<protocol::CandidateSessionConfig> config);
    137 
    138   base::WeakPtr<ChromotingHost> AsWeakPtr() {
    139     return weak_factory_.GetWeakPtr();
    140   }
    141 
    142   // The host uses a pairing registry to generate and store pairing information
    143   // for clients for PIN-less authentication.
    144   scoped_refptr<protocol::PairingRegistry> pairing_registry() const {
    145     return pairing_registry_;
    146   }
    147   void set_pairing_registry(
    148       scoped_refptr<protocol::PairingRegistry> pairing_registry) {
    149     pairing_registry_ = pairing_registry;
    150   }
    151 
    152  private:
    153   friend class ChromotingHostTest;
    154 
    155   typedef std::list<ClientSession*> ClientList;
    156 
    157   // Immediately disconnects all active clients. Host-internal components may
    158   // shutdown asynchronously, but the caller is guaranteed not to receive
    159   // callbacks for disconnected clients after this call returns.
    160   void DisconnectAllClients();
    161 
    162   // Unless specified otherwise all members of this class must be
    163   // used on the network thread only.
    164 
    165   // Parameters specified when the host was created.
    166   DesktopEnvironmentFactory* desktop_environment_factory_;
    167   scoped_ptr<protocol::SessionManager> session_manager_;
    168   scoped_refptr<base::SingleThreadTaskRunner> audio_task_runner_;
    169   scoped_refptr<base::SingleThreadTaskRunner> input_task_runner_;
    170   scoped_refptr<base::SingleThreadTaskRunner> video_capture_task_runner_;
    171   scoped_refptr<base::SingleThreadTaskRunner> video_encode_task_runner_;
    172   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
    173   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
    174 
    175   // Connection objects.
    176   SignalStrategy* signal_strategy_;
    177 
    178   // Must be used on the network thread only.
    179   ObserverList<HostStatusObserver> status_observers_;
    180 
    181   // The connections to remote clients.
    182   ClientList clients_;
    183 
    184   // True if the host has been started.
    185   bool started_;
    186 
    187   // Configuration of the protocol.
    188   scoped_ptr<protocol::CandidateSessionConfig> protocol_config_;
    189 
    190   // Login backoff state.
    191   net::BackoffEntry login_backoff_;
    192 
    193   // Flags used for RejectAuthenticatingClient().
    194   bool authenticating_client_;
    195   bool reject_authenticating_client_;
    196 
    197   // True if the curtain mode is enabled.
    198   bool enable_curtaining_;
    199 
    200   // The maximum duration of any session.
    201   base::TimeDelta max_session_duration_;
    202 
    203   // The pairing registry for PIN-less authentication.
    204   scoped_refptr<protocol::PairingRegistry> pairing_registry_;
    205 
    206   base::WeakPtrFactory<ChromotingHost> weak_factory_;
    207 
    208   DISALLOW_COPY_AND_ASSIGN(ChromotingHost);
    209 };
    210 
    211 }  // namespace remoting
    212 
    213 #endif  // REMOTING_HOST_CHROMOTING_HOST_H_
    214