MediaDISK.cc

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#include "zypp/base/Logger.h"
#include "zypp/base/String.h"
#include "zypp/media/Mount.h"
#include "zypp/media/MediaDISK.h"
#include "zypp/media/MediaManager.h"

#include <iostream>
#include <fstream>
#include <sstream>

#include <sys/types.h>
#include <sys/mount.h>
#include <errno.h>
#include <dirent.h>

/*
** verify devices names as late as possible (while attach)
*/
#define DELAYED_VERIFY           1

using namespace std;

namespace zypp {
  namespace media {

    //
    //  CLASS NAME : MediaDISK
    //

    //
    //
    //  METHOD NAME : MediaDISK::MediaDISK
    //  METHOD TYPE : Constructor
    //
    //  DESCRIPTION :
    //
    MediaDISK::MediaDISK( const Url &      url_r,
                          const Pathname & attach_point_hint_r )
        : MediaHandler( url_r, attach_point_hint_r,
                    url_r.getPathName(), // urlpath below attachpoint
                    false ) // does_download
    {
      MIL << "MediaDISK::MediaDISK(" << url_r << ", " << attach_point_hint_r << ")" << endl;

      _device = Pathname(_url.getQueryParam("device")).asString();
      if( _device.empty())
      {
        ERR << "Media url does not contain a device specification" << std::endl;
        ZYPP_THROW(MediaBadUrlEmptyDestinationException(_url));
      }
#if DELAYED_VERIFY
      DBG << "Verify of " << _device << " delayed" << std::endl;
#else
      if( !verifyIfDiskVolume( _device))
      {
        ZYPP_THROW(MediaBadUrlEmptyDestinationException(_url));
      }
#endif

      _filesystem = _url.getQueryParam("filesystem");
      if(_filesystem.empty())
        _filesystem="auto";

    }

    //
    //  METHOD NAME : MediaDISK::verifyIfDiskVolume
    //  METHOD TYPE : void
    //
    //  DESCRIPTION : Check if specified device file name is
    //                a disk volume device or throw an error.
    //
    bool MediaDISK::verifyIfDiskVolume(const Pathname &dev_name)
    {
      if( dev_name.empty() ||
          dev_name.asString().compare(0, sizeof("/dev/")-1, "/dev/"))
      {
        ERR << "Specified device name " << dev_name
            << " is not allowed" << std::endl;
        return false;
      }

      PathInfo dev_info(dev_name);
      if( !dev_info.isBlk())
      {
        ERR << "Specified device name " << dev_name
            << " is not a block device" << std::endl;
        return false;
      }

      // check if a volume using /dev/disk/by-uuid links first
      {
        Pathname            dpath("/dev/disk/by-uuid");
        std::list<Pathname> dlist;
        if( zypp::filesystem::readdir(dlist, dpath) == 0)
        {
          std::list<Pathname>::const_iterator it;
          for(it = dlist.begin(); it != dlist.end(); ++it)
          {
            PathInfo vol_info(*it);
            if( vol_info.isBlk() && vol_info.devMajor() == dev_info.devMajor() &&
                                    vol_info.devMinor() == dev_info.devMinor())
            {
              DBG << "Specified device name " << dev_name
                  << " is a volume (disk/by-uuid link "
                  << vol_info.path() << ")"
                  << std::endl;
              return true;
            }
          }
        }
      }

      // check if a volume using /dev/disk/by-label links
      // (e.g. vbd mapped volumes in a XEN vm)
      {
        Pathname            dpath("/dev/disk/by-label");
        std::list<Pathname> dlist;
        if( zypp::filesystem::readdir(dlist, dpath) == 0)
        {
          std::list<Pathname>::const_iterator it;
          for(it = dlist.begin(); it != dlist.end(); ++it)
          {
            PathInfo vol_info(*it);
            if( vol_info.isBlk() && vol_info.devMajor() == dev_info.devMajor() &&
                                    vol_info.devMinor() == dev_info.devMinor())
            {
              DBG << "Specified device name " << dev_name
                  << " is a volume (disk/by-label link "
                  << vol_info.path() << ")"
                  << std::endl;
              return true;
            }
          }
        }
      }

      // check if a filesystem volume using the 'blkid' tool
      // (there is no /dev/disk link for some of them)
      ExternalProgram::Arguments args;
      args.push_back( "blkid" );
      args.push_back( "-p" );
      args.push_back( dev_name.asString() );

      ExternalProgram cmd( args, ExternalProgram::Stderr_To_Stdout );
      cmd >> DBG;
      if ( cmd.close() != 0 )
      {
        ERR << cmd.execError() << endl
            << "Specified device name " << dev_name
            << " is not a usable disk volume"
            << std::endl;
        return false;
      }
      return true;
    }

    //
    //
    //  METHOD NAME : MediaDISK::attachTo
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that not already attached, and attachPoint is a directory.
    //
    void MediaDISK::attachTo(bool next)
    {
      if(next)
        ZYPP_THROW(MediaNotSupportedException(url()));
      // FIXME
      // do mount --bind <partition>/<dir> to <to>
      //   mount /dev/<partition> /tmp_mount
      //   mount /tmp_mount/<dir> <to> --bind -o ro
      // FIXME: try all filesystems

      if(_device.empty())
        ZYPP_THROW(MediaBadUrlEmptyDestinationException(url()));

      PathInfo dev_info(_device);
      if(!dev_info.isBlk())
        ZYPP_THROW(MediaBadUrlEmptyDestinationException(url()));
#if DELAYED_VERIFY
      DBG << "Verifying " << _device << " ..." << std::endl;
      if( !verifyIfDiskVolume( _device))
      {
        ZYPP_THROW(MediaBadUrlEmptyDestinationException(_url));
      }
#endif

      if(_filesystem.empty())
        ZYPP_THROW(MediaBadUrlEmptyFilesystemException(url()));

      MediaSourceRef media( new MediaSource(
        "disk", _device, dev_info.devMajor(), dev_info.devMinor()
      ));
      AttachedMedia  ret( findAttachedMedia( media));

      if( ret.mediaSource &&
          ret.attachPoint &&
          !ret.attachPoint->empty())
      {
        DBG << "Using a shared media "
            << ret.mediaSource->name
            << " attached on "
            << ret.attachPoint->path
            << endl;

        removeAttachPoint();
        setAttachPoint(ret.attachPoint);
        setMediaSource(ret.mediaSource);
        return;
      }

      MediaManager  manager;
      MountEntries  entries( manager.getMountEntries());
      MountEntries::const_iterator e;
      for( e = entries.begin(); e != entries.end(); ++e)
      {
        bool        is_device = false;
        std::string dev_path(Pathname(e->src).asString());
        PathInfo    dev_info;

        if( dev_path.compare(0, sizeof("/dev/")-1, "/dev/") == 0 &&
            dev_info(e->src) && dev_info.isBlk())
        {
          is_device = true;
        }

        if( is_device && media->maj_nr == dev_info.devMajor() &&
                         media->min_nr == dev_info.devMinor())
        {
          AttachPointRef ap( new AttachPoint(e->dir, false));
          AttachedMedia  am( media, ap);
          {
            DBG << "Using a system mounted media "
                << media->name
                << " attached on "
                << ap->path
                << endl;

            media->iown = false; // mark attachment as foreign

            setMediaSource(media);
            setAttachPoint(ap);
            return;
          }
        }
      }

      if( !isUseableAttachPoint( attachPoint() ) )
      {
        setAttachPoint( createAttachPoint(), true );
      }
      std::string mountpoint( attachPoint().asString() );

      Mount mount;
      string options = _url.getQueryParam("mountoptions");
      if(options.empty())
      {
        options = "ro";
      }

      if( !media->bdir.empty())
      {
        options += ",bind";
        mount.mount(media->bdir, mountpoint, "none", options);
      }
      else
      {
        mount.mount(_device, mountpoint, _filesystem, options);
      }

      setMediaSource(media);

      // wait for /etc/mtab update ...
      // (shouldn't be needed)
      int limit = 3;
      bool mountsucceeded;
      while( !(mountsucceeded=isAttached()) && --limit)
      {
        sleep(1);
      }

      if( !mountsucceeded)
      {
        setMediaSource(MediaSourceRef());
        try
        {
          mount.umount(attachPoint().asString());
        }
        catch (const MediaException & excpt_r)
        {
          ZYPP_CAUGHT(excpt_r);
        }
        ZYPP_THROW(MediaMountException(
          "Unable to verify that the media was mounted",
          _device, mountpoint
        ));
      }
    }

    //
    //  METHOD NAME : MediaDISK::isAttached
    //  METHOD TYPE : bool
    //
    //  DESCRIPTION : Override check if media is attached.
    //
    bool
    MediaDISK::isAttached() const
    {
      return checkAttached(false);
    }

    //
    //
    //  METHOD NAME : MediaDISK::releaseFrom
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that media is attached.
    //
    void MediaDISK::releaseFrom( const std::string & ejectDev )
    {
      AttachedMedia am( attachedMedia());
      if(am.mediaSource && am.mediaSource->iown)
      {
        Mount mount;
        mount.umount(attachPoint().asString());
      }
    }

    //
    //  METHOD NAME : MediaDISK::getFile
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that media is attached.
    //
    void MediaDISK::getFile (const Pathname & filename, const ByteCount &expectedFileSize_r) const
    {
      MediaHandler::getFile( filename, expectedFileSize_r );
    }

    //
    //  METHOD NAME : MediaDISK::getDir
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that media is attached.
    //
    void MediaDISK::getDir( const Pathname & dirname, bool recurse_r ) const
    {
      MediaHandler::getDir( dirname, recurse_r );
    }

    //
    //
    //  METHOD NAME : MediaDISK::getDirInfo
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that media is attached and retlist is empty.
    //
    void MediaDISK::getDirInfo( std::list<std::string> & retlist,
                                const Pathname & dirname, bool dots ) const
    {
      MediaHandler::getDirInfo( retlist, dirname, dots );
    }

    //
    //
    //  METHOD NAME : MediaDISK::getDirInfo
    //  METHOD TYPE : PMError
    //
    //  DESCRIPTION : Asserted that media is attached and retlist is empty.
    //
    void MediaDISK::getDirInfo( filesystem::DirContent & retlist,
                                const Pathname & dirname, bool dots ) const
    {
      MediaHandler::getDirInfo( retlist, dirname, dots );
    }

    bool MediaDISK::getDoesFileExist( const Pathname & filename ) const
    {
      return MediaHandler::getDoesFileExist( filename );
    }

  } // namespace media
} // namespace zypp
// vim: set ts=8 sts=2 sw=2 ai noet: