dev_tunnelled.h

   1 /*
   2  * dev_tunnelled.h
   3  *
   4  * Home page of code is: http://www.smartmontools.org
   5  *
   6  * Copyright (C) 2008 Christian Franke
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #ifndef DEV_TUNNELLED_H
  12 #define DEV_TUNNELLED_H
  13
  14 #define DEV_TUNNELLED_H_CVSID "$Id: dev_tunnelled.h 4848 2018-12-05 18:30:46Z chrfranke $"
  15
  16 #include "dev_interface.h"
  17
  18 /////////////////////////////////////////////////////////////////////////////
  19 // tunnelled_device_base
  20
  21 /// Common functionality for all tunnelled_device classes.
  22
  23 class tunnelled_device_base
  24 : virtual public /*implements*/ smart_device
  25 {
  26 protected:
  27   explicit tunnelled_device_base(smart_device * tunnel_dev);
  28
  29 public:
  30   virtual ~tunnelled_device_base() throw();
  31
  32   virtual bool is_open() const;
  33
  34   virtual bool open();
  35
  36   virtual bool close();
  37
  38   virtual bool owns(const smart_device * dev) const;
  39
  40   virtual void release(const smart_device * dev);
  41
  42 private:
  43   smart_device * m_tunnel_base_dev;
  44 };
  45
  46
  47 /////////////////////////////////////////////////////////////////////////////
  48 // tunnelled_device
  49
  50 /// Implement a device by tunneling through another device
  51
  52 template <class BaseDev, class TunnelDev>
  53 class tunnelled_device
  54 : public BaseDev,
  55   public tunnelled_device_base
  56 {
  57 public:
  58   typedef TunnelDev tunnel_device_type;
  59
  60 protected:
  61   explicit tunnelled_device(tunnel_device_type * tunnel_dev)
  62     : smart_device(smart_device::never_called),
  63       tunnelled_device_base(tunnel_dev),
  64       m_tunnel_dev(tunnel_dev)
  65     { }
  66
  67   // For nvme_device
  68   explicit tunnelled_device(tunnel_device_type * tunnel_dev, unsigned nsid)
  69     : smart_device(smart_device::never_called),
  70       BaseDev(nsid),
  71       tunnelled_device_base(tunnel_dev),
  72       m_tunnel_dev(tunnel_dev)
  73     { }
  74
  75 public:
  76   virtual void release(const smart_device * dev)
  77     {
  78       if (m_tunnel_dev == dev)
  79         m_tunnel_dev = 0;
  80       tunnelled_device_base::release(dev);
  81     }
  82
  83   tunnel_device_type * get_tunnel_dev()
  84     { return m_tunnel_dev; }
  85
  86   const tunnel_device_type * get_tunnel_dev() const
  87     { return m_tunnel_dev; }
  88
  89 private:
  90   tunnel_device_type * m_tunnel_dev;
  91 };
  92
  93 #endif // DEV_TUNNELLED_H