Mount.cc

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/*---------------------------------------------------------------------\
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|                          / /__ | | | | | |                           |
|                         /_____||_| |_| |_|                           |
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\---------------------------------------------------------------------*/
#include <mntent.h>

#include <cstdio>
#include <climits>
#include <cerrno>

#include <iostream>
#include <fstream>
#include <string>

#include "zypp/base/ExternalDataSource.h"
#include "zypp/base/Logger.h"
#include "zypp/media/Mount.h"
#include "zypp/media/MediaException.h"

#include "zypp/PathInfo.h"

#ifndef N_
#define N_(STR) STR
#endif

using namespace std;

namespace zypp {
  namespace media {

    std::ostream & operator<<( std::ostream & str, const MountEntry & obj )
    {
      str << obj.src << " on " << obj.dir << " type " << obj.type;
      if ( ! obj.opts.empty() )
        str << " (" << obj.opts << ")";
      return str;
    }


Mount::Mount()
{
    process = 0;
    exit_code = -1;
}

Mount::~Mount()
{
   MIL <<  "~Mount()" << endl;

   if ( process )
      delete process;

   process = NULL;

   MIL << "~Mount() end" << endl;
}

void Mount::mount( const std::string & source,
                   const std::string & target,
                   const std::string & filesystem,
                   const std::string & options,
                   const Environment & environment )
{
    const char *const argv[] = {
        "/bin/mount",
        "-t", filesystem.c_str(),
        "-o", options.c_str(),
        source.c_str(),
        target.c_str(),
        NULL
     };

    std::string err;

    this->run(argv, environment, ExternalProgram::Stderr_To_Stdout);

    if ( process == NULL )
    {
      ZYPP_THROW(MediaMountException("Mounting media failed", source, target));
    }

    string value;
    string output = process->receiveLine();

    // parse error messages
    while ( output.length() > 0)
    {
        string::size_type       ret;

        // extract \n
        ret = output.find_first_of ( "\n" );
        if ( ret != string::npos )
        {
            value.assign ( output, 0, ret );
        }
        else
        {
            value = output;
        }

        DBG << "stdout: " << value << endl;

        if  ( value.find ( "is already mounted on" ) != string::npos )
        {
            err = "Media already mounted";
        }
        else if  ( value.find ( "ermission denied" ) != string::npos )
        {
            err = "Permission denied";
        }
        else if  ( value.find ( "wrong fs type" ) != string::npos )
        {
            err = "Invalid filesystem on media";
        }
        else if  ( value.find ( "No medium found" ) != string::npos )
        {
            err = "No medium found";
        }
        else if  ( value.find ( "Not a directory" ) != string::npos )
        {
            if( filesystem == "nfs" || filesystem == "nfs4" )
            {
                err = "Nfs path is not a directory";
            }
            else
            {
               err = "Unable to find directory on the media";
            }
        }

        output = process->receiveLine();
    }

    int status = Status();

    if ( status == 0 )
    {
        // return codes overwites parsed error message
        err = "";
    }
    else if ( status != 0 && err == "" )
    {
        err = "Mounting media failed";
    }

    if ( err != "" ) {
      WAR << "mount " << source << " " << target << ": " << err << endl;
      ZYPP_THROW(MediaMountException(err, source, target, value));
    } else {
      MIL << "mounted " << source << " " << target << endl;
    }
}

void Mount::umount( const std::string & path )
{
    const char *const argv[] = {
        "/bin/umount",
        path.c_str(),
        NULL
     };

    std::string err;

    this->run(argv, ExternalProgram::Stderr_To_Stdout);

    if ( process == NULL )
    {
        ZYPP_THROW(MediaUnmountException("E_mount_failed", path));
    }

    string value;
    string output = process->receiveLine();

    // parse error messages
    while ( output.length() > 0)
    {
        string::size_type       ret;

        // extract \n
        ret = output.find_first_of ( "\n" );
        if ( ret != string::npos )
        {
            value.assign ( output, 0, ret );
        }
        else
        {
            value = output;
        }

        DBG << "stdout: " << value << endl;

        // if  ( value.find ( "not mounted" ) != string::npos )
        // {
        //    err = Error::E_already_mounted;
        // }

        if  ( value.find ( "device is busy" ) != string::npos )
        {
            err = "Device is busy";
        }

        output = process->receiveLine();
    }

    int status = Status();

    if ( status == 0 )
    {
        // return codes overwites parsed error message
        err = "";
    }
    else if ( status != 0 && err == "" )
    {
        err = "Unmounting media failed";
    }

    if ( err != "") {
      WAR << "umount " << path << ": " << err << endl;
      ZYPP_THROW(MediaUnmountException(err, path));
    } else {
      MIL << "unmounted " << path << endl;
    }
}

void Mount::run( const char *const *argv, const Environment& environment,
                 ExternalProgram::Stderr_Disposition disp )
{
  exit_code = -1;

  if ( process != NULL )
  {
     delete process;
     process = NULL;
  }
  // Launch the program

  process = new ExternalProgram(argv, environment, disp, false, -1, true);
}

/*--------------------------------------------------------------*/
/* Return the exit status of the Mount process, closing the     */
/* connection if not already done                               */
/*--------------------------------------------------------------*/
int Mount::Status()
{
   if ( process == NULL )
      return -1;

   exit_code = process->close();
   process->kill();
   delete process;
   process = 0;

   DBG << "exit code: " << exit_code << endl;

   return exit_code;
}

/* Forcably kill the process */
void Mount::Kill()
{
  if (process) process->kill();
}

// STATIC
MountEntries
Mount::getEntries(const std::string &mtab)
{
  MountEntries             entries;
  std::vector<std::string> mtabs;
  bool                     verbose = false;

  if( mtab.empty())
  {
    mtabs.push_back("/proc/mounts");
    // Also read /etc/mtab if it is a file (on newer sytems
    // mtab is a symlink to /proc/mounts).
    // Reason for this is the different representation of
    // mounted loop devices:
    //   /etc/mtab:    /tmp/SLES-11-SP2-MINI-ISO-x86_64-Beta2-DVD.iso on /mnt type iso9660 (ro,loop=/dev/loop0)
    //   /proc/mounts: /dev/loop0 /mnt iso9660 ro,relatime 0 0
    if ( PathInfo( "/etc/mtab", PathInfo::LSTAT ).isFile() )
      mtabs.push_back("/etc/mtab");
  }
  else
  {
    mtabs.push_back(mtab);
  }

  std::vector<std::string>::const_iterator t;
  for( t=mtabs.begin(); t != mtabs.end(); ++t)
  {
    if( verbose)
    {
      DBG << "Reading mount table from '" << *t << "'" << std::endl;
    }
    FILE *fp = setmntent(t->c_str(), "re");
    if( fp)
    {
      char          buf[PATH_MAX * 4];
      struct mntent ent;

      memset(buf,  0, sizeof(buf));
      memset(&ent, 0, sizeof(ent));

      while( getmntent_r(fp, &ent, buf, sizeof(buf)) != NULL)
      {
        if( ent.mnt_fsname && *ent.mnt_fsname &&
            ent.mnt_dir    && *ent.mnt_dir    &&
            ent.mnt_type   && *ent.mnt_type   &&
            ent.mnt_opts   && *ent.mnt_opts)
        {
          MountEntry entry(
            ent.mnt_fsname, ent.mnt_dir,
            ent.mnt_type,   ent.mnt_opts,
            ent.mnt_freq,   ent.mnt_passno
          );

          // Attempt quick fix for bnc#710269:
          // MountEntry is "//dist/install/ on /var/adm/mount/AP_0x00000001 type cifs (ro,relatime,unc=\dist\install,username=,domain=suse.de"
          // but looking for "Looking for media(cifs<//dist/install>)attached(*/var/adm/mount/AP_0x00000001)"
          // Kick the trailing '/' in "//dist/install/"
          // TODO: Check and fix comparison in MediaHandler::checkAttached instead.
          if ( entry.src.size() > 1     // not for "/"
               && entry.src[entry.src.size()-1] == '/' )
          {
            entry.src.erase( entry.src.size()-1 );
          }
          entries.push_back(entry);

          memset(buf,  0, sizeof(buf));
          memset(&ent, 0, sizeof(ent));
        }
      }
      endmntent(fp);

      if( entries.empty())
      {
        WAR << "Unable to read any entry from the mount table '" << *t << "'"
            << std::endl;
      }
      else
      {
        // OK, have a non-empty mount table.
        t = mtabs.end();
        break;
      }
    }
    else
    {
      int err = errno;
      verbose = true;
      WAR << "Failed to read the mount table '" << *t << "': "
          << ::strerror(err)
          << std::endl;
      errno = err;
    }
  }
  return entries;
}

  } // namespace media
} // namespace zypp