libisoburn-0.2.2/libisoburn/libisoburn.h

Go to the documentation of this file.

/*
  API definition of libisoburn.

  Copyright 2007-2008 Vreixo Formoso Lopes <metalpain2002@yahoo.es>
                  and Thomas Schmitt <scdbackup@gmx.net>
*/

/**                           Overview

libisoburn is a frontend for libraries libburn and libisofs which enables
creation and expansion of ISO-9660 filesystems on all CD/DVD media supported
by libburn. This includes media like DVD+RW, which do not support multi-session
management on media level and even plain disk files or block devices.

The price for that is thorough specialization on data files in ISO-9660
filesystem images. So libisoburn is not suitable for audio (CD-DA) or any
other CD layout which does not entirely consist of ISO-9660 sessions.


                          Connector functions

libisofs and libburn do not depend on each other but share some interfaces
by which they can cooperate.
libisoburn establishes the connection between both modules by creating the
necessary interface objects and attaching them to the right places.


                          Wrapper functions 

The priciple of this frontend is that you may use any call of libisofs or
libburn unless it has a  isoburn_*()  wrapper listed in the following function
documentation.

E.g. call isoburn_initialize() rather than iso_init(); burn_initialize();
and call isoburn_drive_scan_and_grab() rather than burn_drive_scan_and_grab().
But you may call  burn_disc_get_profile()  directly if you want to display
the media type.

The wrappers will transparently provide the necessary emulations which
are appropriate for particular target drives and media states.
To learn about them you have to read both API descriptions: the one of
the wrapper and the one of the underlying libburn or libisofs call.

Macros BURN_* and functions burn_*() are documented in <libburn/libburn.h>
Macros ISO_* and functions iso_*() are documented in <libisofs/libisofs.h>


                             Usage model

There may be an input drive and an output drive. Either of them may be missing
with the consequence that no reading resp. writing is possible.
Both drive roles can be fulfilled by the same drive.

Input can be a random access readable libburn drive:
  optical media, regular files, block devices.
Output can be any writeable libburn drive:
  writeable optical media in burner, writeable file objects (no directories).

libburn demands rw-permissions to drive device file resp. file object.

If the input drive provides a suitable ISO RockRidge image, then its tree
may be loaded into memory and can then be manipulated by libisofs API calls.
The loading is done by isoburn_read_image() under control of
struct isoburn_read_opts which the application obtains from libisoburn
and manipulates by the family of isoburn_ropt_set_*() functions.

Writing of result images is controlled by libisofs related parameters
in a struct isoburn_imgen_opts which the application obtains from libisoburn
and manipulates by the family of isoburn_igopt_set_*() functions.

All multi-session aspects are handled by libisoburn according to these
settings. The application does not have to analyze media state and write
job parameters. It rather states its desires which libisoburn tries to
fulfill, or else will refuse to start the write run.


              Setup for Growing, Modifying or Blind Growing

The connector function family offers alternative API calls for performing
the setup for several alternative image generation strategies.

Growing:
If input and output drive are the same, then isoburn_prepare_disc() is to
be used. It will lead to an add-on session on appendable or overwriteable
media with existing ISO image. With blank media it will produce a first
session.

Modifying:
If the output drive is not the input drive, and if it bears blank media
or overwriteable without a valid ISO image, then one may produce a consolidated
image with old and new data. This will copy file data from an eventual input
drive with valid image, add any newly introduced data from the local
filesystem, and produce a first session on output media.
To prepare for such an image generation run, use isoburn_prepare_new_image().

Blind Growing:
This method reads the old image from one drive and writes the add-on session
to a different drive. That output drive is nevertheless supposed to
finally lead to the same media from where the session was loaded. Usually it
will be stdio:/dev/fd/1 (i.e. stdout) being piped into some burn program
like with this classic gesture:
  mkisofs -M $dev -C $msc1,$nwa | cdrecord -waiti dev=$dev
Blind growing is prepared by the call isoburn_prepare_blind_grow().
The input drive should be released immediately after this call in order
to allow the consumer of the output stream to access that drive for writing.

After either of these setups, some peripheral libburn drive parameter settings
like  burn_write_opts_set_simulate(),  burn_write_opts_set_multi(),
 burn_drive_set_speed(),  burn_write_opts_set_underrun_proof()  should be made.
Do not set the write mode. It will be chosen by libisoburn so it matches job
and media state.

                           Writing the image

Then one may start image generation and write threads by isoburn_disc_write().
Progress may be watched at the output drive by burn_drive_get_status() and
isoburn_get_fifo_status().

At some time, the output drive will be BURN_DRIVE_IDLE indicating that
writing has ended.
One should inquire isoburn_drive_wrote_well() to learn about overall success.

Finally one must call isoburn_activate_session() which will complete any
eventual multi-session emulation.

*/


                          /* API functions */


/** Initialize libisoburn, libisofs and libburn.
    Wrapper for : iso_init() and burn_initialize()
    @since 0.1.0
    @param msg  A character array for eventual messages (e.g. with errors)
    @param flag Bitfield for control purposes (unused yet, submit 0) 
    @return 1 indicates success, 0 is failure
*/
int isoburn_initialize(char msg[1024], int flag);


/** Check whether all features of header file libisoburn.h from the given
    major.minor.micro revision triple can be delivered by the library version
    which is performing this call.
    An application of libisoburn can easily memorize the version of the
    libisofs.h header in its own code. Immediately after isoburn_initialize()
    it should simply do this check:
        if (! isoburn_is_compatible(isoburn_header_version_major,
                                    isoburn_header_version_minor,
                                    isoburn_header_version_micro, 0))
           ...refuse to start the program with this dynamic library version...
    @since 0.1.0
    @param major obtained at build time
    @param minor obtained at build time
    @param micro obtained at build time
    @param flag Bitfield for control purposes. Unused yet. Submit 0.
    @return 1= library can work for caller
            0= library is not usable in some aspects. Caller must restrict
               itself to an earlier API version or must not use this libray
               at all.
*/
int isoburn_is_compatible(int major, int minor, int micro, int flag);


/** Obtain the three release version numbers of the library. These are the
    numbers encountered by the application when linking with libisoburn,
    i.e. possibly not before run time.
    Better do not base the fundamental compatibility decision of an application
    on these numbers. For a reliable check use isoburn_is_compatible().
    @since 0.1.0
    @param major The maturity version (0 for now, as we are still learning)
    @param minor The development goal version.
    @param micro The development step version. This has an additional meaning:

                 Pare numbers indicate a version with frozen API. I.e. you can
                 rely on the same set of features to be present in all
                 published releases with that major.minor.micro combination.
                 Features of a pare release will stay available and ABI
                 compatible as long as the SONAME of libisoburn stays "1".
                 Currently there are no plans to ever change the SONAME.
                 
                 Odd numbers indicate that API upgrades are in progress.
                 I.e. new features might be already present or they might
                 be still missing. Newly introduced features may be changed
                 incompatibly or even be revoked before release of a pare
                 version.
                 So micro revisions {1,3,5,7,9} should never be used for
                 dynamic linking unless the proper library match can be
                 guaranteed by external circumstances.

    @return 1 success, <=0 might in future become an error indication
*/
void isoburn_version(int *major, int *minor, int *micro);


/** The minimum version of libisofs to be used with this version of libisoburn
    at compile time.
    @since 0.1.0
*/
#define isoburn_libisofs_req_major  0
#define isoburn_libisofs_req_minor  6
#define isoburn_libisofs_req_micro  6

/** The minimum version of libburn to be used with this version of libisoburn
    at compile time.
    @since 0.1.0
*/
#define isoburn_libburn_req_major  0
#define isoburn_libburn_req_minor  5
#define isoburn_libburn_req_micro  0


/** The minimum version of libisofs to be used with this version of libisoburn
    at runtime. This is checked already in isoburn_initialize() which will
    refuse on outdated version. So this call is for information purposes after
    successful startup only.
    @since 0.1.0
    @param major isoburn_libisofs_req_major as seen at build time
    @param minor as seen at build time
    @param micro as seen at build time
    @return 1 success, <=0 might in future become an error indication
*/
int isoburn_libisofs_req(int *major, int *minor, int *micro);


/** The minimum version of libburn to be used with this version of libisoburn
    at runtime. This is checked already in isoburn_initialize() which will
    refuse on outdated version. So this call is for information purposes after
    successful startup only.
    @since 0.1.0
    @param major isoburn_libburn_req_major as seen at build time
    @param minor as seen at build time
    @param micro as seen at build time
    @return 1 success, <=0 might in future become an error indication
*/
int isoburn_libburn_req(int *major, int *minor, int *micro);


/** These three release version numbers tell the revision of this header file
    and of the API it describes. They are memorized by applications at build
    time.
    @since 0.1.0
*/
#define isoburn_header_version_major  0
#define isoburn_header_version_minor  2
#define isoburn_header_version_micro  2
/** Note:
    Above version numbers are also recorded in configure.ac because libtool
    wants them as parameters at build time.
    For the library compatibility check, ISOBURN_*_VERSION in configure.ac
    are not decisive. Only the three numbers here do matter.
*/
/** Usage discussion:

Some developers of the libburnia project have differing
opinions how to ensure the compatibility of libaries
and applications.

It is about whether to use at compile time and at runtime
the version numbers isoburn_header_version_* provided here.
Thomas Schmitt advises to use them.
Vreixo Formoso advises to use other means.

At compile time:

Vreixo Formoso advises to leave proper version matching
to properly programmed checks in the the application's
build system, which will eventually refuse compilation.

Thomas Schmitt advises to use the macros defined here
for comparison with the application's requirements of
library revisions and to eventually break compilation.

Both advises are combinable. I.e. be master of your
build system and have #if checks in the source code
of your application, nevertheless.

At runtime (via *_is_compatible()):

Vreixo Formoso advises to compare the application's
requirements of library revisions with the runtime
library. This is to allow runtime libraries which are
young enough for the application but too old for
the lib*.h files seen at compile time.

Thomas Schmitt advises to compare the header
revisions defined here with the runtime library.
This is to enforce a strictly monotonous chain
of revisions from app to header to library,
at the cost of excluding some older libraries.

These two advises are mutually exclusive.

-----------------------------------------------------

For an implementation of the Thomas Schmitt approach,
see libisoburn/burn_wrap.c : isoburn_initialize()
This connects libisoburn as "application" with libisofs
as "library".

The compatible part of Vreixo Formoso's approach is implemented
in configure.ac LIBBURN_REQUIRED, LIBISOFS_REQUIRED.
In isoburn_initialize() it would rather test by
  iso_lib_is_compatible(isoburn_libisofs_req_major,...
than by
  iso_lib_is_compatible(iso_lib_header_version_major,...
and would leave out the ugly compile time traps.

*/


/** Announce to the library an application provided method for immediate
    delivery of messages. It is used when no drive is affected directly or
    if the drive has no own msgs_submit() method attached by
    isoburn_drive_set_msgs_submit.
    If no method is preset or if the method is set to NULL then libisoburn
    delivers its messages through the message queue of libburn.
    @param msgs_submit   The function call which implements the method
    @param submit_handle Handle to be used as first argument of msgs_submit
    @param submit_flag   Flag to be used as last argument of msgs_submit
    @param flag          Unused yet, submit 0
    @since 0.2.0
*/
int isoburn_set_msgs_submit(int (*msgs_submit)(void *handle, int error_code,
                                                  char msg_text[], int os_errno,
                                                  char severity[], int flag),
                               void *submit_handle, int submit_flag, int flag);


/** Aquire a target drive by its filesystem path resp. libburn persistent
    address.
    Wrapper for: burn_drive_scan_and_grab()
    @since 0.1.0
    @param drive_infos On success returns a one element array with the drive
                  (cdrom/burner). Thus use with driveno 0 only. On failure
                  the array has no valid elements at all.
                  The returned array should be freed via burn_drive_info_free()
                  when the drive is no longer needed.
    @param adr    The persistent address of the desired drive.
    @param load   1 attempt to load the disc tray. 0 no attempt,rather failure.
    @return       1 = success , 0 = drive not found , <0 = other error
*/
int isoburn_drive_scan_and_grab(struct burn_drive_info *drive_infos[],
                                char* adr, int load);


/** Aquire a target drive by its filesystem path resp. libburn persistent
    address. This is a modern successor of isoburn_drive_scan_and_grab().  
    Wrapper for: burn_drive_scan_and_grab()
    @since 0.1.2
    @param drive_infos On success returns a one element array with the drive
                  (cdrom/burner). Thus use with driveno 0 only. On failure
                  the array has no valid elements at all.
                  The returned array should be freed via burn_drive_info_free()
                  when the drive is no longer needed.
    @param adr    The persistent address of the desired drive.
    @param flag   bit0= attempt to load the disc tray.
                        Else: failure if not loaded.
                  bit1= regard overwriteable media as blank
                  bit2= if the drive is a regular disk file: truncate it to
                        the write start address
                  bit3= if the drive reports a read-only profile try to read
                        table of content by scanning for ISO image headers.
                        (depending on media type and drive this might
                         help or it might make the resulting toc even worse)
    @return       1 = success , 0 = drive not found , <0 = other error
*/
int isoburn_drive_aquire(struct burn_drive_info *drive_infos[],
                                char* adr, int flag);

/** Aquire a drive from the burn_drive_info[] array which was obtained by
    a previous call of burn_drive_scan(). 
    Wrapper for: burn_drive_grab()
    @since 0.1.0
    @param drive The drive to grab. E.g. drive_infos[1].drive .
    @param load  1 attempt to load the disc tray. 0 no attempt, rather failure.
    @return      1 success, <=0 failure
*/
int isoburn_drive_grab(struct burn_drive *drive, int load);


/** Attach to a drive an application provided method for immediate
    delivery of messages.
    If no method is set or if the method is set to NULL then libisoburn
    delivers messages of the drive through the global msgs_submit() method
    set by isoburn_set_msgs_submiti() or by the message queue of libburn.
    @since 0.2.0
    @param d     The drive to which this function, handle and flag shall apply
    @param msgs_submit   The function call which implements the method
    @param submit_handle Handle to be used as first argument of msgs_submit
    @param submit_flag   Flag to be used as last argument of msgs_submit
    @param flag          Unused yet, submit 0
*/
int isoburn_drive_set_msgs_submit(struct burn_drive *d,
                            int (*msgs_submit)(void *handle, int error_code,
                                               char msg_text[], int os_errno,
                                               char severity[], int flag),
                            void *submit_handle, int submit_flag, int flag);


/** Inquire the media status. Expect the whole spectrum of libburn BURN_DISC_*
    with multi-session media. Emulated states with random access media are
    BURN_DISC_BLANK and BURN_DISC_APPENDABLE.
    Wrapper for: burn_disc_get_status()
    @since 0.1.0
    @param drive The drive to inquire.
    @return The status of the drive, or what kind of disc is in it.
            Note: BURN_DISC_UNGRABBED indicates wrong API usage
*/
enum burn_disc_status isoburn_disc_get_status(struct burn_drive *drive);


/** Tells whether the media can be treated by isoburn_disc_erase().
    Wrapper for: burn_disc_erasable()
    @since 0.1.0
    @param drive The drive to inquire.
    @return      0=not erasable , else erasable
*/
int isoburn_disc_erasable(struct burn_drive *d);


/** Mark the media as blank. With multi-session media this will call
    burn_disc_erase(). With random access media, an eventual ISO-9660
    filesystem will get invalidated by altering its start blocks on media.
    In case of success, the media is in status BURN_DISC_BLANK afterwards.
    Wrapper for: burn_disc_erase()
    @since 0.1.0
    @param drive The drive with the media to erase.
    @param fast 1=fast erase, 0=thorough erase
               With DVD-RW, fast erase yields media incapable of multi-session.
*/
void isoburn_disc_erase(struct burn_drive *drive, int fast);


/** Set up isoburn_disc_get_msc1() to return a fabricated value.
    This makes only sense between aquiring the drive and reading the
    image. After isoburn_read_image() it will confuse the coordination
    of libisoburn and libisofs.
    Note: Sessions and tracks are counted beginning with 1, not with 0.
    @since 0.1.6
    @param drive The drive where msc1 is to be set
    @param adr_mode Determines how to interpret adr_value and to set msc1.
                    If adr_value shall represent a number then decimal ASCII
                    digits are expected.
                    0= start lba of last session in TOC, ignore adr_value
                    1= start lba of session number given by adr_value
                    2= start lba of track given number by adr_value
                    3= adr_value itself is the lba to be used
                    4= start lba of last session with volume id
                       given by adr_value
    @parm adr_value A string describing the value to be eventually used.
    @param flag Bitfield for control purposes.
                bit0= @since 0.2.2
                      with adr_mode 3: adr_value might be 16 blocks too high
                      (e.g. -C stemming from growisofs). Probe for ISO head
                      at adr_value-16 and eventually adjust setting. 
*/
int isoburn_set_msc1(struct burn_drive *d, int adr_mode, char *adr_value,
                     int flag);


/* ----------------------------------------------------------------------- */
/* 

  Wrappers for emulation of TOC on overwriteable media

  Media which match the overwriteable usage model lack of a history of sessions
  and tracks. libburn will not even hand out a burn_disc object for them and
  always declare them blank. libisoburn checks for a valid ISO filesystem
  header at LBA 0 and eventually declares them appendable.
  Nevertheless one can only determine an upper limit of the size of the overall
  image (by isoburn_get_min_start_byte()) but not a list of stored sessions
  and their LBAs, as it is possible with true multi-session media.

  The following wrappers add the capability to obtain a session and track TOC
  from emulated multi-session images on overwriteables if the first session
  was written by libisoburn-0.1.6 or later (i.e. with a header copy at LBA 32).

  Be aware that the structs emitted by these isoburn calls are not compatible
  with the libburn structs. I.e. you may use them only with isoburn_toc_*
  calls. 
  isoburn_toc_disc needs to be freed after use. isoburn_toc_session and
  isoburn_toc_track vanish together with their isoburn_toc_disc.
*/

/* Opaque handles to media, session, track */
struct isoburn_toc_disc;
struct isoburn_toc_session;
struct isoburn_toc_track;


/** Obtain a master handle for the table of content.
    This handle governs allocated resources which have to be released by
    isoburn_toc_disc_free() when no longer needed.
    Wrapper for: burn_drive_get_disc()
    @since 0.1.6
    @param drive The drive with the media to inspect
    @return NULL in case there is no content info, else it is a valid handle
*/
struct isoburn_toc_disc *isoburn_toc_drive_get_disc(struct burn_drive *d);


/** Tell the number of 2048 byte blocks covered by the table of content.
    Wrapper for: burn_disc_get_sectors()
    @since 0.1.6
    @param disc The master handle of the media
    @return number of blocks, <=0 indicates unknown or unreadable state
*/
int isoburn_toc_disc_get_sectors(struct isoburn_toc_disc *disc);


/** Get the array of session handles from the table of content.
    Wrapper for: burn_disc_get_sessions()
    @since 0.1.6
    @param disc The master handle of the media
    @param num returns the number of sessions in the array
    @return the address of the array of session handles
*/
struct isoburn_toc_session **isoburn_toc_disc_get_sessions(
                                      struct isoburn_toc_disc *disc, int *num);


/** Tell the number of 2048 byte blocks covered by a particular session.
    Wrapper for: burn_session_get_sectors()
    @since 0.1.6
    @param s The session handle
    @return number of blocks, <=0 indicates unknown or unreadable state
*/
int isoburn_toc_session_get_sectors(struct isoburn_toc_session *s);


/** Obtain a copy of the entry which describes the end of a particular session.
    Wrapper for: burn_session_get_leadout_entry()
    @since 0.1.6
    @param s The session handle
    @param entry A pointer to memory provided by the caller. It will be filled
                 with info according to struct burn_toc_entry as defined
                 in libburn.h
*/
void isoburn_toc_session_get_leadout_entry(struct isoburn_toc_session *s,
                                       struct burn_toc_entry *entry);


/** Get the array of track handles from a particular session.
    Wrapper for: burn_session_get_tracks()
    @since 0.1.6
    @param s The session handle
    @param num returns the number of tracks in the array
    @return the address of the array of track handles
*/
struct isoburn_toc_track **isoburn_toc_session_get_tracks(
                                      struct isoburn_toc_session *s, int *num);


/** Obtain a copy of the entry which describes a particular itrack.
    Wrapper for: burn_track_get_entry()
    @since 0.1.6
    @param s The track handle
    @param entry A pointer to memory provided by the caller. It will be filled
                 with info according to struct burn_toc_entry as defined
                 in libburn.h
*/
void isoburn_toc_track_get_entry(struct isoburn_toc_track *t,
                                 struct burn_toc_entry *entry);


/** Release the memory associated with a master handle of media.
    The handle is invalid afterwards and may not be used any more.
    Wrapper for: burn_disc_free()
    @since 0.1.6
    @param disc The master handle of the media
*/
void isoburn_toc_disc_free(struct isoburn_toc_disc *disc);


/** Try whether the data at the given address look like a ISO 9660
    image header and obtain its alleged size. Depending on the info mode
    one other string of text information can be retrieved too.
    @since 0.1.6
    @param drive The drive with the media to inspect
    @param lba   The block number from where to read
    @param image_blocks  The number of 2048 bytes blocks
    @param info  Caller provided memory, enough to take eventual info reply
    @param flag bit0-7: info return mode
                 0= do not return anything in info (do not even touch it)
                 1= copy volume id to info (info needs 33 bytes)
                 2= @since 0.2.2 :
                    copy 64 kB header to info (needs 65536 bytes) 
                bit13= @since 0.2.2:
                      do not read head from media but use first 64 kB from info
                bit14= check both half buffers (not only second)
                       return 2 if found in first block
                bit15= return-1 on read error
    @return >0 seems to be a valid ISO image, 0 format not recognized, <0 error
*/
int isoburn_read_iso_head(struct burn_drive *d, int lba,
                          int *image_blocks, char *info, int flag);


/* ----------------------------------------------------------------------- */
/*

  Options for image reading.

  An application shall create an option set object by isoburn_ropt_new(),
  program it by isoburn_ropt_set_*(), use it with isoburn_read_image(),
  and finally delete it by isoburn_ropt_destroy().

*/
/* ----------------------------------------------------------------------- */

struct isoburn_read_opts;

/** Produces a set of image read options, initialized with default values.
    @since 0.1.0
    @param o the newly created option set object
    @param flag  Bitfield for control purposes. Submit 0 for now.
    @return 1=ok , <0 = failure
*/
int isoburn_ropt_new(struct isoburn_read_opts **o, int flag);


/** Deletes an option set which was created by isoburn_ropt_new().
    @since 0.1.0
    @param o The option set to work on
    @param flag  Bitfield for control purposes. Submit 0 for now.
    @return 1= **o destroyed , 0= *o was already NULL (harmless)
*/
int isoburn_ropt_destroy(struct isoburn_read_opts **o, int flag);


/** Which existing ISO 9660 extensions in the image to read or not to read.
    Whether to read the content of an existing image at all.
    The bits can be combined by | resp. inquired by &.
    @since 0.1.0
    @param ext Bitfield:
               bit0= norock
                     Do not read Rock Ridge extensions
               bit1= nojoliet
                     Do not read Joliet extensions
               bit2= noiso1999
                     Do not read ISO 9660:1999 enhanced tree
               bit3= preferjoliet
                     When both Joliet and RR extensions are present, the RR
                     tree is used. If you prefer using Joliet, set this to 1.
               bit4= pretend_blank
                     Always create empty image.Ignore any image on input drive.
    @return    1 success, <=0 failure
*/
#define isoburn_ropt_norock         1
#define isoburn_ropt_nojoliet       2
#define isoburn_ropt_noiso1999      4
#define isoburn_ropt_preferjoliet   8
#define isoburn_ropt_pretend_blank 16
int isoburn_ropt_set_extensions(struct isoburn_read_opts *o, int ext);
int isoburn_ropt_get_extensions(struct isoburn_read_opts *o, int *ext);


/** Default attributes to use if no RockRidge extension gets loaded.
    @since 0.1.0
    @param o    The option set to work on
    @param uid  user id number (see /etc/passwd)
    @param gid  group id number (see /etc/group)
    @param mode  permissions (not file type) as of man 2 stat.
                 With directories, r-permissions will automatically imply
                 x-permissions. See isoburn_ropt_set_default_dirperms() below.
    @return      1 success, <=0 failure
*/
int isoburn_ropt_set_default_perms(struct isoburn_read_opts *o,
                                   uid_t uid, gid_t gid, mode_t mode);
int isoburn_ropt_get_default_perms(struct isoburn_read_opts *o,
                                   uid_t *uid, gid_t *gid, mode_t *mode);

/** Default attributes to use on directories if no RockRidge extension
    gets loaded.
    Above call isoburn_ropt_set_default_perms() automatically adds
    x-permissions to r-permissions for directories. This call here may
    be done afterwards to set independend permissions for directories,
    especially to override the automatically added x-permissions.
    @since 0.1.0
    @param o    The option set to work on
    @param mode permissions (not file type) as of man 2 stat.
    @return     1 success, <=0 failure
*/
int isoburn_ropt_set_default_dirperms(struct isoburn_read_opts *o,
                                      mode_t mode);
int isoburn_ropt_get_default_dirperms(struct isoburn_read_opts *o,
                                      mode_t *mode);



/** Set the character set for reading RR file names from ISO images.
    @since 0.1.0
    @param o             The option set to work on
    @param input_charset Set this to NULL to use the default locale charset.
                         For selecting a particular character set, submit its
                         name, e.g. as listed by program iconv -l.
                         Example: "UTF-8". 
    @return              1 success, <=0 failure
*/
int isoburn_ropt_set_input_charset(struct isoburn_read_opts *o,
                                   char *input_charset);
int isoburn_ropt_get_input_charset(struct isoburn_read_opts *o,
                                   char **input_charset);


/** After calling function isoburn_read_image() there are informations
    available in the option set.
    This info can be obtained as bits in parameter has_what. Like:
      joliet_available = (has_what & isoburn_ropt_has_joliet);
    @since 0.1.0
    @param o     The option set to work on
    @param size  Number of image data blocks, 2048 bytes each.
    @param has_what Bitfield:
           bit0= has_rockridge
                 RockRidge extension info is available (POSIX filesystem)
           bit1= has_joliet
                 Joliet extension info is available (suitable for MS-Windows)
           bit2= has_iso1999
                 ISO version 2 Enhanced Volume Descriptor is available.
                 This is rather exotic.
           bit3= has_el_torito
                 El-Torito boot record is present
    @return  1 success, <=0 failure
*/
#define isoburn_ropt_has_rockridge 1
#define isoburn_ropt_has_joliet    2
#define isoburn_ropt_has_iso1999   4
#define isoburn_ropt_has_el_torito 8
int isoburn_ropt_get_size_what(struct isoburn_read_opts *o,
                               uint32_t *size, int *has_what);


/* ----------------------------------------------------------------------- */
/*                      End of Options for image reading                   */
/* ----------------------------------------------------------------------- */

/* ----------------------------------------------------------------------- */
/*

  Options for image generation by libisofs and image transport to libburn.

  An application shall create an option set by isoburn_igopt_new(),
  program it by isoburn_igopt_set_*(), use it with either
  isoburn_prepare_new_image() or isoburn_prepare_disc(), and finally delete
  it by isoburn_igopt_destroy().

*/
/* ----------------------------------------------------------------------- */

struct isoburn_imgen_opts;

/** Produces a set of generation and transfer options, initialized with default
    values.
    @since 0.1.0
    @param o the newly created option set object
    @param flag  Bitfield for control purposes. Submit 0 for now.
    @return 1=ok , <0 = failure
*/
int isoburn_igopt_new(struct isoburn_imgen_opts **o, int flag);


/** Deletes an option set which was created by isoburn_igopt_new().
    @since 0.1.0
    @param o     The option set to give up
    @param flag  Bitfield for control purposes. Submit 0 for now.
    @return 1= **o destroyed , 0= *o was already NULL (harmless)
*/
int isoburn_igopt_destroy(struct isoburn_imgen_opts **o, int flag);


/** ISO level to write at.
    @since 0.1.0
    @param o     The option set to work on
    @param level is a term of the ISO 9660 standard. It should be one of:
                 1= filenames restricted to form 8.3
                 2= filenames allowed up to 31 characters
    @return      1 success, <=0 failure
*/
int isoburn_igopt_set_level(struct isoburn_imgen_opts *o, int level);
int isoburn_igopt_get_level(struct isoburn_imgen_opts *o, int *level);


/** Which extensions to support.
    @since 0.1.0
    @param o     The option set to work on
    @param ext Bitfield:
           bit0= rockridge
                 Rock Ridge extensions add POSIX file attributes like
                 owner, group, access permissions, long filenames. Very
                 advisable if the designed audience has Unix style systems.
           bit1= joliet
                 Longer filenames for Windows systems.
                 Weaker than RockRidge, but also readable with Linux.
           bit2= iso1999
                 This is rather exotic. Better do not surprise the readers.
    @return 1 success, <=0 failure
*/
#define isoburn_igopt_rockridge 1
#define isoburn_igopt_joliet    2
#define isoburn_igopt_iso1999   4
int isoburn_igopt_set_extensions(struct isoburn_imgen_opts *o, int ext);
int isoburn_igopt_get_extensions(struct isoburn_imgen_opts *o, int *ext);

/** Relaxed constraints. Setting any of the bits to 1 break the specifications,
    but it is supposed to work on most moderns systems. Use with caution.
    @since 0.1.0
    @param o     The option set to work on
    @param relax Bitfield:
           bit0= omit_version_numbers
                 Omit the version number (";1") at the end of the
                 ISO-9660 identifiers. Version numbers are usually
                 not used.
           bit1= allow_deep_paths
                 Allow ISO-9660 directory hierarchy to be deeper
                 than 8 levels.
           bit2= allow_longer_paths
                 Allow path in the ISO-9660 tree to have more than
                 255 characters.
           bit3= max_37_char_filenames
                 Allow a single file or directory hierarchy to have
                 up to 37 characters. This is larger than the 31
                 characters allowed by ISO level 2, and the extra space
                 is taken from the version number, so this also forces
                 omit_version_numbers.
           bit4= no_force_dots
                 ISO-9660 forces filenames to have a ".", that separates
                 file name from extension. libisofs adds it if original
                 filename has none. Set this to 1 to prevent this
                 behavior.
           bit5= allow_lowercase 
                 Allow lowercase characters in ISO-9660 filenames.
                 By default, only uppercase characters, numbers and
                 a few other characters are allowed.
           bit6= allow_full_ascii
                 Allow all ASCII characters to be appear on an ISO-9660
                 filename. Note * that "/" and "\0" characters are never
                 allowed, even in RR names.
           bit7= joliet_longer_paths
                 Allow paths in the Joliet tree to have more than
                 240 characters.
    @return 1 success, <=0 failure
*/
#define isoburn_igopt_omit_version_numbers       1
#define isoburn_igopt_allow_deep_paths           2
#define isoburn_igopt_allow_longer_paths         4
#define isoburn_igopt_max_37_char_filenames      8
#define isoburn_igopt_no_force_dots             16
#define isoburn_igopt_allow_lowercase           32
#define isoburn_igopt_allow_full_ascii          64
#define isoburn_igopt_joliet_longer_paths      128
int isoburn_igopt_set_relaxed(struct isoburn_imgen_opts *o, int relax);
int isoburn_igopt_get_relaxed(struct isoburn_imgen_opts *o, int *relax);


/** Whether and how files should be sorted.
    @since 0.1.0
    @param o     The option set to work on
    @param value Bitfield: bit0= sort_files_by_weight
                                 files should be sorted based on their weight.
                                 Weight is attributed to files in the image
                                 by libisofs call iso_node_set_sort_weight().
    @return 1 success, <=0 failure
*/
#define isoburn_igopt_sort_files_by_weight        1
int isoburn_igopt_set_sort_files(struct isoburn_imgen_opts *o, int value);
int isoburn_igopt_get_sort_files(struct isoburn_imgen_opts *o, int *value);


/** Set the override values for files and directory permissions.
    The parameters replace_* these take one of three values: 0, 1 or 2.
    If 0, the corresponding attribute will be kept as set in the IsoNode
    at the time of image generation.
    If set to 1, the corresponding attrib. will be changed by a default
    suitable value.
    With value 2, the attrib. will be changed with the value specified
    in the corresponding *_mode options. Note that only the permissions
    are set, the file type remains unchanged.
    @since 0.1.0
    @param o                 The option set to work on
    @param replace_dir_mode  whether and how to override directories
    @param replace_file_mode whether and how to override files of other type
    @param dir_mode          Mode to use on dirs with replace_dir_mode == 2.
    @param file_mode;        Mode to use on files with replace_file_mode == 2.
    @return 1 success, <=0 failure
*/
int isoburn_igopt_set_over_mode(struct isoburn_imgen_opts *o,
                               int replace_dir_mode, int replace_file_mode,
                               mode_t dir_mode, mode_t file_mode);
int isoburn_igopt_get_over_mode(struct isoburn_imgen_opts *o,
                               int *replace_dir_mode, int *replace_file_mode,
                               mode_t *dir_mode, mode_t *file_mode);

/** Set the override values values for group id and user id.
    The rules are like with above overriding of mode values. replace_* controls
    whether and how. The other two parameters provide values for eventual use.
    @since 0.1.0
    @param o                 The option set to work on
    @param replace_uid       whether and how to override user ids
    @param replace_gid       whether and how to override group ids
    @param uid               User id to use with replace_uid == 2.
    @param gid               Group id to use on files with replace_gid == 2.
    @return 1 success, <=0 failure
*/
int isoburn_igopt_set_over_ugid(struct isoburn_imgen_opts *o,
                               int replace_uid, int replace_gid,
                               uid_t uid, gid_t gid);
int isoburn_igopt_get_over_ugid(struct isoburn_imgen_opts *o,
                               int *replace_uid, int *replace_gid,
                               uid_t *uid, gid_t *gid);

/** Set the charcter set to use for representing filenames in the image.
    @since 0.1.0
    @param o              The option set to work on
    @param output_charset Set this to NULL to use the default output charset.
                          For selecting a particular character set, submit its
                          name, e.g. as listed by program iconv -l.
                          Example: "UTF-8". 
    @return 1 success, <=0 failure
*/
int isoburn_igopt_set_out_charset(struct isoburn_imgen_opts *o,
                                 char *output_charset);
int isoburn_igopt_get_out_charset(struct isoburn_imgen_opts *o,
                                 char **output_charset);


/** The number of bytes to be used for the fifo which decouples libisofs
    and libburn for better throughput and for reducing the risk of
    interrupting signals hitting the libburn thread which operates the
    MMC drive.
    The size will be rounded up to the next full 2048.
    Minimum is 64kiB, maximum is 1 GiB (but that is too much anyway).
    @since 0.1.0
    @param o          The option set to work on
    @param fifo_size  Number of bytes to use
    @return 1 success, <=0 failure
*/
int isoburn_igopt_set_fifo_size(struct isoburn_imgen_opts *o, int fifo_size);
int isoburn_igopt_get_fifo_size(struct isoburn_imgen_opts *o, int *fifo_size);


/** Obtain after image preparation the block address where the session will
    start on media.
    This value cannot be set by the application but only be inquired.
    @since 0.1.4
    @param o          The option set to work on
    @param lba        The block number of the session start on media.
                      <0 means that no address has been determined yet.
    @return 1 success, <=0 failure
*/
int isoburn_igopt_get_effective_lba(struct isoburn_imgen_opts *o, int *lba);


/* ----------------------------------------------------------------------- */
/*                      End of Options for image generation                */
/* ----------------------------------------------------------------------- */


/** Get the image attached to a drive, if any.
    @since 0.1.0
    @param d The drive to inquire
    @return A reference to attached image, or NULL if the drive has no image
            attached. This reference needs to be released via iso_image_unref()
            when it is not longer needed.
*/
IsoImage *isoburn_get_attached_image(struct burn_drive *d);


/** Load the ISO filesystem directory tree from the media in the given drive.
    This will give libisoburn the base on which it can let libisofs perform
    image growing or image modification. The loaded volset gets attached
    to the drive object and handed out to the application.
    Not a wrapper, but peculiar to libisoburn.
    @since 0.1.0
    @param d The drive which holds an existing ISO filesystem or blank media.
             d is allowed to be NULL which produces an empty ISO image. In
             this case one has to call before writing isoburn_attach_volset()
             with the volset from this call and with the intended output
             drive.
    @param read_opts The read options which can be chosen by the application
    @param image the image read, if the disc is blank it will have no files.
             This reference needs to be released via iso_image_unref() when
             it is not longer needed. The drive, if not NULL, will hold an
             own reference which it will release when it gets a new volset
             or when it gets released via isoburn_drive_release().
             You can pass NULL if you already have a reference or you plan to
             obtain it later with isoburn_get_attached_image(). Of course, if
             you haven't specified a valid drive (i.e., if d == NULL), this
             parameter can't be NULL.
    @return <=0 error , 1 = success
*/
int isoburn_read_image(struct burn_drive *d,
                       struct isoburn_read_opts *read_opts,
                       IsoImage **image);

/** Set a callback function for producing pacifier messages during the lengthy
    process of image reading. The callback function and the application handle
    are stored until they are needed for the underlying call to libisofs.
    Other than with libisofs the handle is managed entirely by the application.
    An idle .free() function is exposed to libisofs. The handle has to stay
    valid until isoburn_read_image() is done. It has to be detached by
      isoburn_set_read_pacifier(drive, NULL, NULL);
    before it may be removed from memory.
    @since 0.1.0
    @param drive  The drive which will be used with isoburn_read_image()
                  It has to be aquired by an isoburn_* wrapper call.
    @param read_pacifier  The callback function
    @param app_handle  The app handle which the callback function can obtain
                       via iso_image_get_attached_data() from its IsoImage*
    @return 1 success, <=0 failure
*/
int isoburn_set_read_pacifier(struct burn_drive *drive,
                              int (*read_pacifier)(IsoImage*, IsoFileSource*),
                              void *app_handle);


/** Set the IsoImage to be used with a drive. This eventually releases
    the reference to the old IsoImage attached to the drive.
    Caution: Use with care. It hardly makes sense to replace an image that
             reflects a valid ISO image on media.
    This call is rather intended for writing a newly created and populated
    image to blank media. The use case in xorriso is to let an image survive
    the change or demise of the outdev target drive. 
    @since 0.1.0
    @param d The drive which shall be write target of the volset.
    @param image The image that represents the image to be written.
             This image pointer MUST already be a valid reference suitable
             for iso_image_unref().
             It may have been obtained by appropriate libisofs calls or by
             isoburn_read_image() with d==NULL.
    @return <=0 error , 1 = success
*/ 
int isoburn_attach_image(struct burn_drive *d, IsoImage *image);


/** Return the best possible estimation of the currently available capacity of
    the media. This might depend on particular write option settings and on
    drive state.
    An eventual start address for emulated multi-session will be subtracted
    from the capacity estimation given by burn_disc_available_space().
    Negative results get defaulted to 0.
    Wrapper for: burn_disc_available_space()
    @since 0.1.0
    @param d The drive to query.
    @param o If not NULL: write parameters to be set on drive before query
    @return number of most probably available free bytes
*/
off_t isoburn_disc_available_space(struct burn_drive *d,
                                   struct burn_write_opts *o);


/** Obtain the start block number of the most recent session on media. In
    case of random access media this will always be 0. Succesfull return is
    not a guarantee that there is a ISO-9660 image at all. The call will fail,
    nevertheless,if isoburn_disc_get_status() returns not BURN_DISC_APPENDABLE.
    Note: The result of this call may be fabricated by a previous call of
    isoburn_set_msc1() which can override the rule to load the most recent
    session.
    Wrapper for: burn_disc_get_msc1()
    @since 0.1.0
    @param d         The drive to inquire
    @param start_lba Contains on success the start address in 2048 byte blocks
    @return <=0 error , 1 = success
*/
int isoburn_disc_get_msc1(struct burn_drive *d, int *start_lba);


/** Use this with trackno==0 to obtain the predicted start block number of the
    new session. The interesting number is returned in parameter nwa.
    Wrapper for: burn_disc_track_lba_nwa()
    @since 0.1.0
    @param d         The drive to inquire
    @param o If not NULL: write parameters to be set on drive before query
    @param trackno Submit 0.
    @param lba return value: start lba
    @param nwa return value: Next Writeable Address
    @return 1=nwa is valid , 0=nwa is not valid , -1=error
*/
int isoburn_disc_track_lba_nwa(struct burn_drive *d, struct burn_write_opts *o,
                               int trackno, int *lba, int *nwa);


/** Obtain the size which was attributed to an emulated appendable on actually
    overwriteable media. This value is supposed to be <= 2048 * nwa as of
    isoburn_disc_track_lba_nwa().
    @since 0.1.0
    @param drive The drive holding the media.
    @param start_byte The reply value counted in bytes, not in sectors.
    @param flag  Unused yet. Submit 0.
    @return 1=stat_byte is valid, 0=not an emulated appendable, -1=error 
*/
int isoburn_get_min_start_byte(struct burn_drive *d, off_t *start_byte,
                               int flag);


/** To choose the expansion method of Growing:
    Create a disc object for writing the new session from the created or loaded
    iso_volset which has been manipulated via libisofs, to the same media from
    where the image was eventually loaded. This struct burn_disc is ready for
    use by a subsequent call to isoburn_disc_write().
    After this asynchronous writing has ended and the drive is BURN_DRIVE_IDLE
    again, the burn_disc object has to be disposed by burn_disc_free().
    @since 0.1.0
    @param drive The combined source and target drive, grabbed with
                 isoburn_drive_scan_and_grab(). .
    @param disc Returns the newly created burn_disc object.
    @param opts Image generation options, see isoburn_igopt_*()
    @return <=0 error , 1 = success
*/
int isoburn_prepare_disc(struct burn_drive *drive, struct burn_disc **disc,
                         struct isoburn_imgen_opts *opts);


/** To choose the expansion method of Modifying:
    Create a disc object for producing a new image from a previous image
    plus the changes made by user. The generated burn_disc is suitable
    to be written to a grabbed drive with blank writeable media.
    But you must not use the same drive for input and output, because data
    will be read from the source drive while at the same time the target
    drive is already writing.
    The resulting burn_disc object has to be disposed when all its writing
    is done and the drive is BURN_DRIVE_IDLE again after asynchronous
    burn_disc_write().
    @since 0.1.0
    @param in_drive The input drive, grabbed with isoburn_drive_aquire() or
                    one of its alternatives.
    @param disc     Returns the newly created burn_disc object.
    @param opts     Options for image generation and data transport to media.
    @param out_drive The output drive, from isoburn_drive_aquire() et.al..
    @return <=0 error , 1 = success
*/
int isoburn_prepare_new_image(struct burn_drive *in_drive,
                              struct burn_disc **disc,
                              struct isoburn_imgen_opts *opts,
                              struct burn_drive *out_drive);


/** To choose the expansion method of Blind Growing:
    Create a disc object for writing an add-on session from the created or
    loaded IsoImage which has been manipulated via libisofs, to a different
    drive than the one from where it was loaded.
    Usually output will be stdio:/dev/fd/1 (i.e. stdout) being piped
    into some burn program like with this classic gesture:
      mkisofs -M $dev -C $msc1,$nwa | cdrecord -waiti dev=$dev
    Parameter translation into libisoburn:
      $dev  is the address by which parameter in_drive of this call was aquired
      $msc1 was set by isoburn_set_msc1() before image reading
            or was detected from the in_drive media
      $nwa  is a parameter of this call
            or can be used as detected from the in_drive media

    This call waits for libisofs output to become available and then detaches
    the input drive object from the data source object by which libisofs was
    reading from the input drive.
    So, as far as libisofs is concerned, that drive may be released immediately
    after this call in order to allow the consumer to access the drive for
    writing.
    The consumer should wait for input to become available and only then open
    its burn drive. With cdrecord this is caused by option -waiti.
  
    The resulting burn_disc object has to be disposed when all its writing
    is done and the drive is BURN_DRIVE_IDLE again after asynchronous
    burn_disc_write().
    @since 0.2.2
    @param in_drive The input drive,grabbed with isoburn_drive_scan_and_grab().
    @param disc     Returns the newly created burn_disc object.
    @param opts     Options for image generation and data transport to media.
    @param out_drive The output drive, from isoburn_drive_aquire() et.al..
                    typically stdio:/dev/fd/1 .
    @param nwa      The address (2048 byte block count) where the add-on
                    session will be finally stored on a mountable media
                    or in a mountable file.
                    If nwa is -1 then the address is used as determined from
                    the in_drive media.
    @return <=0 error , 1 = success
*/
int isoburn_prepare_blind_grow(struct burn_drive *d, struct burn_disc **disc,
                         struct isoburn_imgen_opts *opts,
                         struct burn_drive *out_drive, int nwa);


/**
    Revoke isoburn_prepare_new_image() or isoburn_prepare_disc() instead of
    running isoburn_disc_write().
    libisofs reserves resources and maybe already starts generating the
    image stream when one of above two calls is performed. It is mandatory to
    either run isoburn_disc_write() or to revoke the preparations by the
    call described here.
    @since 0.1.0
    @param input_drive   The drive resp. in_drive which was used with the
                         preparation call.
    @param output_drive  The out_drive used with isoburn_prepare_new_image(),
                         NULL if none.
    @param flag Bitfield, submit 0 for now.
                bit0= -reserved for internal use-
    @return     <0 error, 0= no pending preparations detectable, 1 = canceled
*/
int isoburn_cancel_prepared_write(struct burn_drive *input_drive,
                                  struct burn_drive *output_drive, int flag);


/** Start writing of the new session.
    This call is asynchrounous. I.e. it returns quite soon and the progress has
    to be watched by a loop with call burn_drive_get_status() until
    BURN_DRIVE_IDLE is returned.
    Wrapper for: burn_disc_write()
    @since 0.1.0
    @param o    Options which control the burn process. See burnwrite_opts_*()
                in libburn.h.
    @param disc Disc object created either by isoburn_prepare_disc() or by
                isoburn_prepare_new_image().
*/
void isoburn_disc_write(struct burn_write_opts *o, struct burn_disc *disc);


/** Inquire state and fill parameters of the fifo which is attached to
    the emerging track. This should be done in the pacifier loop while
    isoburn_disc_write() or burn_disc_write() are active.
    This works only with drives obtained by isoburn_drive_scan_and_grab()
    or isoburn_drive_grab(). If isoburn_prepare_new_image() was used, then
    parameter out_drive must have announced the track output drive.
    Hint: If only burn_write_opts and not burn_drive is known, then the drive
          can be obtained by burn_write_opts_get_drive().
    @since 0.1.0
    @parm d      The drive to which the track with the fifo gets burned.
    @param size  The total size of the fifo
    @param free_bytes  The current free capacity of the fifo
    @param status_text  Returns a pointer to a constant text, see below
    @return  <0 reply invalid, >=0 fifo status code:
             bit0+1=input status, bit2=consumption status, i.e:
             0="standby"   : data processing not started yet
             1="active"    : input and consumption are active
             2="ending"    : input has ended without error
             3="failing"   : input had error and ended,
             4="unused"    : ( consumption has ended before processing start )
             5="abandoned" : consumption has ended prematurely
             6="ended"     : consumption has ended without input error
             7="aborted"   : consumption has ended after input error
*/
int isoburn_get_fifo_status(struct burn_drive *d, int *size, int *free_bytes,
                            char **status_text);


/** Inquire whether the most recent write run was successful.
    Wrapper for: burn_drive_wrote_well()
    @since 0.1.0
    @param d  The drive to inquire
    @return   1=burn seems to have went well, 0=burn failed
*/
int isoburn_drive_wrote_well(struct burn_drive *d);


/** Call this after isoburn_disc_write has finished and burn_drive_wrote_well()
    indicates success. It will eventually complete the emulation of
    multi-session functionality, if needed at all. Let libisoburn decide.
    Not a wrapper, but peculiar to libisoburn.
    @since 0.1.0
    @param d  The output drive to which the session was written
    @return   1 success , <=0 failure
*/
int isoburn_activate_session(struct burn_drive *drive);


/** Wait after normal end of operations until libisofs ended all write
    threads and freed resource reservations.
    This call is not mandatory. But without it, messages from the ending
    threads might appear after the application ended its write procedure.
    @since 0.1.0
    @param input_drive   The drive resp. in_drive which was used with the
                         preparation call.
    @param output_drive  The out_drive used with isoburn_prepare_new_image(),
                         NULL if none.
    @param flag Bitfield, submit 0 for now.
    @return     <=0 error , 1 = success
*/
int isoburn_sync_after_write(struct burn_drive *input_drive,
                             struct burn_drive *output_drive, int flag);


/** Release an aquired drive.
    Wrapper for: burn_drive_release()
    @since 0.1.0
    @param drive The drive to be released
    @param eject 1= eject media from drive , 0= do not eject
*/
void isoburn_drive_release(struct burn_drive *drive, int eject);


/** Shutdown all three libraries.
    Wrapper for : iso_finish() and burn_finish().
    @since 0.1.0
*/
void isoburn_finish(void);


/*
    The following calls are for expert applications only.
    An application should have a special reason to use them.
*/


/** Inquire wether the media needs emulation or would be suitable for
    generic multi-session via libburn.
    @since 0.1.0
    @param d  The drive to inquire
    @return 0 is generic multi-session 
            1 is emulated multi-session
           -1 is not suitable for isoburn
*/
int isoburn_needs_emulation(struct burn_drive *drive);
 

---