libisoburn/libisoburn/burn_wrap.c

/*
   cc -g -c \
      -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE=1 -D_LARGEFILE64_SOURCE \
      burn_wrap.c
*/
/* libburn wrappers for libisoburn 

   Copyright 2007 - 2010  Thomas Schmitt, <scdbackup@gmx.net> 
   Provided under GPL version 2 or later.
*/

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

/* <<< A70929 : hardcoded CD-RW with fabricated -msinfo 
#define Hardcoded_cd_rW 1
#define Hardcoded_cd_rw_c1     12999
#define Hardcoded_cd_rw_nwA   152660 
*/

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <regex.h>

#ifdef Xorriso_with_libjtE
#include <libjte/libjte.h>
#endif

#ifndef Xorriso_standalonE

#include <libburn/libburn.h>

#include <libisofs/libisofs.h>

#else /* ! Xorriso_standalonE */

#include "../libisofs/libisofs.h"
#include "../libburn/libburn.h"

#endif /* Xorriso_standalonE */


#include "libisoburn.h"
#include "isoburn.h"


/* The global list of isoburn objects. Usually there is only one. */
extern struct isoburn *isoburn_list_start; /* in isoburn.c */

/* Default values for application provided msgs_submit methods.
   To be attached to newly aquired drives.
   Storage location is isoburn.c
*/
extern int (*libisoburn_default_msgs_submit)
    (void *handle, int error_code, char msg_text[],
                 int os_errno, char severity[], int flag);
extern void *libisoburn_default_msgs_submit_handle;
extern int libisoburn_default_msgs_submit_flag;


static int isoburn_emulate_toc(struct burn_drive *d, int flag);


int isoburn_initialize(char msg[1024], int flag)
{
 int major, minor, micro, bad_match= 0, no_iso_init= 0;


/* First the ugly compile time checks for header version compatibility.
   If everthing matches, then they produce no C code. In case of mismatch,
   intentionally faulty C code will be inserted.
*/

#ifdef iso_lib_header_version_major
/* The minimum requirement of libisoburn towards the libisofs header
   at compile time is defined in libisoburn/libisoburn.h :
     isoburn_libisofs_req_major
     isoburn_libisofs_req_minor
     isoburn_libisofs_req_micro
   It gets compared against the version macros in libisofs/libisofs.h :
     iso_lib_header_version_major
     iso_lib_header_version_minor
     iso_lib_header_version_micro
   If the header is too old then the following code shall cause failure of
   libisoburn compilation rather than to allow production of a program with
   unpredictable bugs or memory corruption.
   The compiler messages supposed to appear in this case are:
      error: 'LIBISOFS_MISCONFIGURATION' undeclared (first use in this function)
      error: 'INTENTIONAL_ABORT_OF_COMPILATION__HEADERFILE_libisofs_dot_h_TOO_OLD__SEE_libisoburn_dot_h_AND_burn_wrap_dot_h' undeclared (first use in this function)
      error: 'LIBISOFS_MISCONFIGURATION_' undeclared (first use in this function)
*/
/* The indendation is an advise of man gcc to help old compilers ignoring */
 #if isoburn_libisofs_req_major > iso_lib_header_version_major
 #define Isoburn_libisofs_dot_h_too_olD 1
 #endif
 #if isoburn_libisofs_req_major == iso_lib_header_version_major && isoburn_libisofs_req_minor > iso_lib_header_version_minor
 #define Isoburn_libisofs_dot_h_too_olD 1
 #endif
 #if isoburn_libisofs_req_minor == iso_lib_header_version_minor && isoburn_libisofs_req_micro > iso_lib_header_version_micro
 #define Isoburn_libisofs_dot_h_too_olD 1
 #endif

#ifdef Isoburn_libisofs_dot_h_too_olD
LIBISOFS_MISCONFIGURATION = 0;
INTENTIONAL_ABORT_OF_COMPILATION__HEADERFILE_libisofs_dot_h_TOO_OLD__SEE_libisoburn_dot_h_AND_burn_wrap_dot_c = 0;
LIBISOFS_MISCONFIGURATION_ = 0;
#endif

#endif /* iso_lib_header_version_major */

/* The minimum requirement of libisoburn towards the libburn header
   at compile time is defined in libisoburn/libisoburn.h :
     isoburn_libburn_req_major
     isoburn_libburn_req_minor
     isoburn_libburn_req_micro
   It gets compared against the version macros in libburn/libburn.h :
     burn_header_version_major
     burn_header_version_minor
     burn_header_version_micro
   If the header is too old then the following code shall cause failure of
   cdrskin compilation rather than to allow production of a program with
   unpredictable bugs or memory corruption.
   The compiler messages supposed to appear in this case are:
      error: 'LIBBURN_MISCONFIGURATION' undeclared (first use in this function)
      error: 'INTENTIONAL_ABORT_OF_COMPILATION__HEADERFILE_libburn_dot_h_TOO_OLD__SEE_libisoburn_dot_h_and_burn_wrap_dot_h' undeclared (first use in this function)
      error: 'LIBBURN_MISCONFIGURATION_' undeclared (first use in this function)
*/

/* The indendation is an advise of man gcc to help old compilers ignoring */
 #if isoburn_libburn_req_major > burn_header_version_major
 #define Isoburn_libburn_dot_h_too_olD 1
 #endif
 #if isoburn_libburn_req_major == burn_header_version_major && isoburn_libburn_req_minor > burn_header_version_minor
 #define Isoburn_libburn_dot_h_too_olD 1
 #endif
 #if isoburn_libburn_req_minor == burn_header_version_minor && isoburn_libburn_req_micro > burn_header_version_micro
 #define Isoburn_libburn_dot_h_too_olD 1
 #endif

#ifdef Isoburn_libburn_dot_h_too_olD
LIBBURN_MISCONFIGURATION = 0;
INTENTIONAL_ABORT_OF_COMPILATION__HEADERFILE_libburn_dot_h_TOO_OLD__SEE_libisoburn_dot_h_and_burn_wrap_dot_h = 0;
LIBBURN_MISCONFIGURATION_ = 0;
#endif


#ifdef Xorriso_with_libjtE

/* The minimum requirement of libisoburn towards the libjte header
   at compile time is the same as the one of a usable libisfs itowards libjte.
   So the requirement is defined in libisofs/libisofs.h :
     iso_libjte_req_major , iso_libjte_req_minor , iso_libjte_req_micro
*/
 /* The indendation is an advise of man gcc to help old compilers ignoring */
 #if iso_libjte_req_major > LIBJTE_VERSION_MAJOR
 #define Libisofs_libjte_dot_h_too_olD 1
 #endif
 #if iso_libjte_req_major == LIBJTE_VERSION_MAJOR && iso_libjte_req_minor > LIBJTE_VERSION_MINOR
 #define Libisofs_libjte_dot_h_too_olD 1
 #endif
 #if iso_libjte_req_minor == LIBJTE_VERSION_MINOR && iso_libjte_req_micro > LIBJTE_VERSION_MICRO
 #define Libisofs_libjte_dot_h_too_olD 1
 #endif

#ifdef Libisofs_libjte_dot_h_too_olD
LIBJTE_MISCONFIGURATION = 0;
INTENTIONAL_ABORT_OF_COMPILATION__HEADERFILE_libjte_dot_h_TOO_OLD__SEE_libisofs_dot_h_AND_burn_wrap.c_c = 0;
LIBJTE_MISCONFIGURATION_ = 0;
#endif

#endif /* Xorriso_with_libjtE */


/* End of ugly compile time tests (scroll up for explanation) */


 msg[0]= 0;

#ifdef Xorriso_with_libjtE

 libjte__version(&major, &minor, &micro);
 sprintf(msg + strlen(msg), "libjte-%d.%d.%d ", major, minor, micro);
 if (libjte__is_compatible(LIBJTE_VERSION_MAJOR, LIBJTE_VERSION_MINOR,
                                LIBJTE_VERSION_MICRO, 0)) {
   sprintf(msg+strlen(msg), "ok, ");
 } else {
   sprintf(msg + strlen(msg),
           "- TOO OLD -, need at least libjte-%d.%d.%d ,\n",
           LIBJTE_VERSION_MAJOR, LIBJTE_VERSION_MINOR,
           LIBJTE_VERSION_MICRO);
   bad_match= 1;
   no_iso_init= 1; /* iso_init() will fail anyway */
 }

#endif /* Xorriso_with_libjtE */

 if(!no_iso_init) {
   if(iso_init()<0) {
     sprintf(msg+strlen(msg), "Cannot initialize libisofs\n");
     return(0);
   }
 }
 iso_lib_version(&major, &minor, &micro);
 sprintf(msg+strlen(msg), "libisofs-%d.%d.%d ", major, minor, micro);
#ifdef iso_lib_header_version_major
 if(iso_lib_is_compatible(iso_lib_header_version_major,
                          iso_lib_header_version_minor,
                          iso_lib_header_version_micro)) {
   sprintf(msg+strlen(msg), "ok, ");
 } else {
   sprintf(msg+strlen(msg),"- TOO OLD -, need at least libisofs-%d.%d.%d ,\n",
           iso_lib_header_version_major, iso_lib_header_version_minor,
           iso_lib_header_version_micro);
   bad_match= 1;
 }
#else
 if(iso_lib_is_compatible(isoburn_libisofs_req_major,
                          isoburn_libisofs_req_minor,
                          isoburn_libisofs_req_micro)) {
   sprintf(msg+strlen(msg), "suspicious, ");
 } else {
   sprintf(msg+strlen(msg),"- TOO OLD -, need at least libisofs-%d.%d.%d ,\n",
           isoburn_libisofs_req_major, isoburn_libisofs_req_minor,
           isoburn_libisofs_req_micro);
   bad_match= 1;
 }
#endif /* ! iso_lib_header_version_major */

 if(!burn_initialize()) {
   sprintf(msg+strlen(msg), "Cannot initialize libburn\n");
   return(0);
 }
 burn_version(&major, &minor, &micro);
 sprintf(msg+strlen(msg), "libburn-%d.%d.%d ", major, minor, micro);
 if(major > burn_header_version_major
    || (major == burn_header_version_major
        && (minor > burn_header_version_minor
            || (minor == burn_header_version_minor
                && micro >= burn_header_version_micro)))) {
   sprintf(msg+strlen(msg), "ok, ");
 } else {
   sprintf(msg+strlen(msg), "- TOO OLD -, need at least libburn-%d.%d.%d ,\n",
           burn_header_version_major, burn_header_version_minor,
           burn_header_version_micro);
   bad_match= 1;
 }

 isoburn_version(&major, &minor, &micro);
 sprintf(msg+strlen(msg), "for libisoburn-%d.%d.%d", major, minor, micro);
 if(bad_match)
   return(0);

 isoburn_destroy_all(&isoburn_list_start, 0); /* isoburn_list_start= NULL */
 return(1);
}


/* API @since 0.1.0 */
int isoburn_libisofs_req(int *major, int *minor, int *micro)
{
 *major= iso_lib_header_version_major;
 *minor= iso_lib_header_version_minor;
 *micro= iso_lib_header_version_micro;
 return(1);
}


/* API @since 0.1.0 */
int isoburn_libburn_req(int *major, int *minor, int *micro)
{
 *major= burn_header_version_major;
 *minor= burn_header_version_minor;
 *micro= burn_header_version_micro;
 return(1);
}


/* API @since 0.6.4 */
int isoburn_libjte_req(int *major, int *minor, int *micro)
{
 *major= LIBJTE_VERSION_MAJOR;
 *minor= LIBJTE_VERSION_MINOR;
 *micro= LIBJTE_VERSION_MICRO;
 return(1);
}


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)
{
 libisoburn_default_msgs_submit= msgs_submit;
 libisoburn_default_msgs_submit_handle= submit_handle;
 libisoburn_default_msgs_submit_flag= submit_flag;
 return(1);
}


int isoburn_is_intermediate_dvd_rw(struct burn_drive *d, int flag)
{
 int profile, ret= 0, format_status, num_formats;
 char profile_name[80];
 enum burn_disc_status s;
 off_t format_size= -1;
 unsigned bl_sas;

 s= isoburn_disc_get_status(d);
 ret= burn_disc_get_profile(d, &profile, profile_name);
 if(ret>0 && profile==0x13)
   ret= burn_disc_get_formats(d, &format_status, &format_size,
                              &bl_sas, &num_formats);
 if(ret>0 && profile==0x13 && s==BURN_DISC_BLANK &&
    format_status==BURN_FORMAT_IS_UNKNOWN)
   return(1);
 return(0);
}


/** Examines the media and sets appropriate emulation if needed.
    @param flag bit0= pretent blank on overwriteable media
                bit3= if the drive reports a -ROM profile then try to read 
                      table of content by scanning for ISO image headers.
                bit4= do not emulate TOC on overwriteable media
                bit5= ignore ACL from external filesystems
                bit6= ignore POSIX Extended Attributes from external filesystems
                bit7= pretend -ROM and scan for table of content
*/ 
static int isoburn_welcome_media(struct isoburn **o, struct burn_drive *d,
                                 int flag)
{
 int ret, lba, nwa, profile, readonly= 0;
 struct burn_multi_caps *caps= NULL;
 struct isoburn_toc_entry *t;
 char profile_name[80];
 struct isoburn_toc_disc *disc= NULL;
 struct isoburn_toc_session **sessions;
 struct isoburn_toc_track **tracks;
 int num_sessions= 0, num_tracks= 0, track_count= 0, session_no= 0;
 char msg[80];
 enum burn_disc_status s;

 s= burn_disc_get_status(d);
 profile_name[0]= 0;
 ret= burn_disc_get_profile(d, &profile, profile_name);
 if(ret<=0)
   profile= 0x00;
 ret= burn_disc_get_multi_caps(d, BURN_WRITE_NONE, &caps, 0);
 if(ret<0) /* == 0 is read-only media, but it is too early to reject it here */
   goto ex;
 if(ret==0 || (flag & 128))
   readonly= 1;
 if(flag & 128)
   flag = (flag & ~ 16) | 8;
   
 ret= isoburn_new(o, 0);
 if(ret<=0)
   goto ex;
 (*o)->drive= d;
 (*o)->msgs_submit= libisoburn_default_msgs_submit;
 (*o)->msgs_submit_handle= libisoburn_default_msgs_submit_handle;
 (*o)->msgs_submit_flag= libisoburn_default_msgs_submit_flag;
 iso_image_set_ignore_aclea((*o)->image, (flag >> 5 ) & 3);

#ifdef Hardcoded_cd_rW
 /* <<< A70929 : hardcoded CD-RW with fabricated -msinfo */
 caps->start_adr= 0;
 (*o)->fabricated_disc_status= BURN_DISC_APPENDABLE;
#endif

 if(caps->start_adr)
   (*o)->emulation_mode= 1;
 if(caps->start_adr && !readonly) {       /* set emulation to overwriteable */
   ret= isoburn_is_intermediate_dvd_rw(d, 0);
   if(ret>0) {
     (*o)->min_start_byte= 0;
     (*o)->nwa= 0;
     (*o)->zero_nwa= 0;
   }
   if(flag&1) {
     (*o)->nwa= (*o)->zero_nwa;
     (*o)->fabricated_disc_status= BURN_DISC_BLANK;
   } else {
     ret= isoburn_start_emulation(*o, 0);
     if(ret<=0) {
       (*o)->emulation_mode= -1;
       goto ex;
     }
     /* try to read emulated toc */
     ret= isoburn_emulate_toc(d, flag & 16);
     if(ret<0) {
       (*o)->emulation_mode= -1;
       goto ex;
     }
   }
 } else {

    /* >>> recognize unsuitable media (but allow read-only media) */;

   if(readonly && s != BURN_DISC_EMPTY) {
     (*o)->fabricated_disc_status= BURN_DISC_FULL;
     /* This might be overwriteable media in a -ROM drive.
        Pitfall:
        Multi-session media which bear a xorriso image for overwriteables
        in their first session would get a TOC of that first image rather
        than of the media.
        It is not possible to distinguish a BD-RE from a single session
        BD-R with an image for overwriteables. But as soon as the media
        bears 2 logical tracks it cannot be overwriteable.
        So count the number of tracks first.
     */
     disc= isoburn_toc_drive_get_disc(d);
     if(disc != NULL) {
       sessions= isoburn_toc_disc_get_sessions(disc, &num_sessions);
       for(session_no= 0; session_no < num_sessions; session_no++) {
         tracks= isoburn_toc_session_get_tracks(sessions[session_no],
                                                &num_tracks);
         track_count+= num_tracks;
       }
       isoburn_toc_disc_free(disc);
     }

     sprintf(msg, "ROM media has libburn track count = %d", track_count);
     isoburn_msgs_submit(*o, 0x00060000, msg, 0, "DEBUG", 0);

     if((flag & 16) || track_count >= 2) {
       ret= 0; /* toc emulation off, or not overwriteable */
     } else {
       ret= isoburn_emulate_toc(d, 1);
       if(ret<0)
         goto ex;
       else if(ret > 0)
         (*o)->emulation_mode= 1;
     }
     if(ret == 0 && (profile != 0x08 || (flag & 128)) && (flag & 8)) {
       /* This might also be multi-session media which do not
          get shown with a decent TOC.
          CD-R TOC (profile 0x08) can be trusted. Others not.
          Do a scan search of ISO headers.
       */
       ret= isoburn_emulate_toc(d, 1|2);
       if(ret<0)
         goto ex;
       if(ret>0) { /* point msc1 to last session */
         if((*o)->toc!=NULL) {
           for(t= (*o)->toc; t->next!=NULL; t= t->next);
            (*o)->fabricated_msc1= t->start_lba;
         }
       }
     }
   }
#ifdef Hardcoded_cd_rW
   (*o)->nwa= Hardcoded_cd_rw_nwA;
#else
   ret= burn_disc_track_lba_nwa(d, NULL, 0, &lba, &nwa);
   if(ret>0)
     (*o)->nwa= nwa;
#endif

 }

 ret= 1;
ex:
 if(caps!=NULL)
   burn_disc_free_multi_caps(&caps);
 return(ret);
}


/**
    @param flag bit0= load
                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 -ROM profile then try to read 
                      table of content by scanning for ISO image headers.
                      (depending on media type and drive state this might 
                       help or it might make the resulting toc even worse)
                bit4= do not emulate TOC on overwriteable media
                bit5= ignore ACL from external filesystems
                bit6= ignore POSIX Extended Attributes from external filesystems
                bit7= pretend -ROM profile and scan for table of content
*/
int isoburn_drive_aquire(struct burn_drive_info *drive_infos[],
                         char *adr, int flag)
{
 int ret, drive_grabbed= 0;
 struct isoburn *o= NULL;

#ifndef NIX

/* <<< should be obsolete by new drive addressing of libburn-0.5.2 */
/* >>> but helps with kernel 2.4 to use /dev/sr */

 int conv_ret;
 char libburn_drive_adr[BURN_DRIVE_ADR_LEN];

 conv_ret= burn_drive_convert_fs_adr(adr, libburn_drive_adr);
 if(conv_ret<=0)
   strcpy(libburn_drive_adr, adr);
 ret= burn_drive_scan_and_grab(drive_infos, libburn_drive_adr, flag&1);

#else

 ret= burn_drive_scan_and_grab(drive_infos, adr, flag & 1);

#endif /* ! NIX */

 if(ret<=0)
   goto ex;
 drive_grabbed= 1;
 ret= isoburn_welcome_media(&o, (*drive_infos)[0].drive,
                            (flag & (8 | 16 | 32 | 64 | 128)) | !!(flag&2));
 if(ret<=0)
   goto ex;

 if(flag&4) {
   ret= isoburn_find_emulator(&o, (*drive_infos)[0].drive, 0);
   if(ret>0 && o!=NULL)
     o->truncate= 1;
 }

 ret= 1;
ex:
 if(ret<=0) {
   if(drive_grabbed)
     burn_drive_release((*drive_infos)[0].drive, 0);
   isoburn_destroy(&o, 0);
 }
 return(ret);
}


int isoburn_drive_scan_and_grab(struct burn_drive_info *drive_infos[],
                                char *adr, int load)
{
 int ret;

 ret= isoburn_drive_aquire(drive_infos, adr, !!load);
 return(ret);
}


int isoburn_drive_grab(struct burn_drive *drive, int load)
{
 int ret;
 struct isoburn *o= NULL;

 ret= burn_drive_grab(drive, load);
 if(ret<=0)
   goto ex;
 ret= isoburn_welcome_media(&o, drive, 0);
 if(ret<=0)
   goto ex;
 
 ret= 1;
ex:
 if(ret<=0)
   isoburn_destroy(&o,0);
 return(ret);
}


/** Retrieve media emulation and eventual isoburn emulator of drive.
    @return -1 unsuitable media, 0 generic media, 1 emulated media.
*/
int isoburn_find_emulator(struct isoburn **pt,
                                 struct burn_drive *drive, int flag)
{
 int ret;

 ret= isoburn_find_by_drive(pt, drive, 0);
 if(ret<=0)
   return(0);
 if((*pt)->emulation_mode==-1) {
   isoburn_msgs_submit(*pt, 0x00060000,
                    "Unsuitable drive and media state", 0, "FAILURE", 0);
   return(-1);
 }
 if((*pt)->emulation_mode==0)
   return(0);
 return(1);
} 


enum burn_disc_status isoburn_disc_get_status(struct burn_drive *drive)
{
 int ret;
 struct isoburn *o;

 ret= isoburn_find_emulator(&o, drive, 0);
 if(ret<0)
   return(BURN_DISC_UNSUITABLE);
 if(o!=NULL)
   if(o->fabricated_disc_status!=BURN_DISC_UNREADY)
     return(o->fabricated_disc_status);
 if(ret==0)
   return(burn_disc_get_status(drive));

 /* emulated status */
 if(o->emulation_mode==-1)
   return(BURN_DISC_UNSUITABLE);
 if(o->nwa>o->zero_nwa)
   return(BURN_DISC_APPENDABLE);
 return(BURN_DISC_BLANK);
}


int isoburn_disc_erasable(struct burn_drive *d)
{
 int ret;
 struct isoburn *o;

 ret= isoburn_find_emulator(&o, d, 0);
 if(ret>0)
   if(o->emulation_mode==1)
     return(1);
 return burn_disc_erasable(d);
}


void isoburn_disc_erase(struct burn_drive *drive, int fast)
{
 int ret, do_pseudo_blank= 0;
 struct isoburn *o;
 enum burn_disc_status s;
 char zero_buffer[Libisoburn_target_head_sizE];
 struct burn_multi_caps *caps= NULL;

 ret= isoburn_find_emulator(&o, drive, 0);
 if(ret>0) {
   if(o->emulation_mode==-1) {
     /* To cause a negative reply with burn_drive_wrote_well() */
     burn_drive_cancel(drive);
     goto ex;
   }

   if(o->emulation_mode > 0) { /* might be readonly with emulated sessions */
     ret= burn_disc_get_multi_caps(drive, BURN_WRITE_NONE, &caps, 0);
     if(ret > 0 && caps->start_adr)
       do_pseudo_blank= 1;
   }
   if(do_pseudo_blank) {
     s= isoburn_disc_get_status(drive);
     if(s==BURN_DISC_FULL) { /* unknown data format in first 64 kB */
       memset(zero_buffer, 0, Libisoburn_target_head_sizE);
       ret= burn_random_access_write(drive, (off_t) 0, zero_buffer,
                                     (off_t) Libisoburn_target_head_sizE, 1);
     } else {
       ret= isoburn_invalidate_iso(o, 0);
     }
     if(ret<=0)
       burn_drive_cancel(drive); /* mark run as failure */
     goto ex;
   }
 }
 burn_disc_erase(drive, fast);
ex:;
 if(caps!=NULL)
   burn_disc_free_multi_caps(&caps);
}


off_t isoburn_disc_available_space(struct burn_drive *d,
                                   struct burn_write_opts *opts)
{
 int ret;
 struct isoburn *o;
 struct burn_write_opts *eff_opts= NULL, *local_opts= NULL;
 enum burn_disc_status s;
 off_t avail;

 eff_opts= opts;
 ret= isoburn_find_emulator(&o, d, 0);
 if(ret>0 && o!=NULL)
   if(o->emulation_mode!=0) {
     s= isoburn_disc_get_status(d);
     if(s==BURN_DISC_FULL) /* unknown data format in first 64 kB */
       return((off_t) 0);
     local_opts= burn_write_opts_new(d);
     eff_opts= local_opts;
     burn_write_opts_set_start_byte(eff_opts, ((off_t) o->nwa) * (off_t) 2048);
   }
 avail= burn_disc_available_space(d, eff_opts);
 if(local_opts!=NULL)
   burn_write_opts_free(local_opts);
 local_opts= NULL;
 return(avail);
}


int isoburn_disc_get_msc1(struct burn_drive *d, int *start_lba)
{
 int ret;
 struct isoburn *o;

#ifdef Hardcoded_cd_rW
 /* <<< A70929 : hardcoded CD-RW with fabricated -msinfo */
 *start_lba= Hardcoded_cd_rw_c1;
 return(1);
#endif

 if(isoburn_disc_get_status(d)!=BURN_DISC_APPENDABLE &&
    isoburn_disc_get_status(d)!=BURN_DISC_FULL) {
   isoburn_msgs_submit(NULL, 0x00060000,
                       "Media contains no recognizable data", 0, "SORRY", 0);
   return(0);
 }
 ret= isoburn_find_emulator(&o, d, 0);
 if(ret<0)
   return(0);
 if(o->fabricated_msc1>=0) {
   *start_lba= o->fabricated_msc1;
   return(1);
 }
 if(ret>0) if(o->emulation_mode>0) {
   *start_lba= 0;
   return(1);
 }
 return(burn_disc_get_msc1(d, start_lba));
}


int isoburn_disc_track_lba_nwa(struct burn_drive *d,
                               struct burn_write_opts *opts,
                               int trackno, int *lba, int *nwa)
{
 int ret;
 struct isoburn *o;

#ifdef Hardcoded_cd_rW
 /* <<< A70929 : hardcoded CD-RW with fabricated -msinfo */
 *lba= Hardcoded_cd_rw_c1;
 *nwa= Hardcoded_cd_rw_nwA;
 return(1);
#endif

 *nwa= *lba= 0;
 ret= isoburn_find_emulator(&o, d, 0);
 if(ret<0)
   return(0);
 if(ret>0) if(o->emulation_mode>0) {
   *lba= 0;
   *nwa= o->nwa;
   return(1);
 }
 if(burn_drive_get_drive_role(d) != 1)
   return(1);
 return(burn_disc_track_lba_nwa(d, opts, trackno, lba, nwa));
}


int isoburn_get_msc2(struct isoburn *o,
                     struct burn_write_opts *opts, int *msc2, int flag)
{
 int ret, lba, nwa;

 if(o->fabricated_msc2>=0)
   *msc2= o->fabricated_msc2;
 else {
   ret= isoburn_disc_track_lba_nwa(o->drive, opts, 0, &lba, &nwa);
   if(ret<=0)
     return(ret);
   *msc2= nwa;
 }
 return(1);
}


void isoburn_disc_write(struct burn_write_opts *opts, struct burn_disc *disc)
{
 int ret;
 off_t nwa= 0;
 struct isoburn *o;
 struct burn_drive *drive;
 char reasons[BURN_REASONS_LEN],msg[160+BURN_REASONS_LEN];
 char adr[BURN_DRIVE_ADR_LEN];
 enum burn_write_types write_type;
 struct stat stbuf;

 drive= burn_write_opts_get_drive(opts);
 ret= isoburn_find_emulator(&o, drive, 0);
 if(ret<0)
   return;
 if(o!=NULL) {
   o->wrote_well= -1;
   if(o->emulation_mode!=0) {
     burn_write_opts_set_multi(opts, 0);
     if(o->emulation_mode>0 && o->nwa >= 0) {
       nwa= o->nwa;

       /* This caters for unwritten formatted DVD-RW. They need to be written
          sequentially on the first use. Only written areas are random access.
          If the first session is not written to LBA 0, then re-opening of
          formatting and padding is needed. 
          This can be done. But when the track gets closed after padding,
          this lasts a long time. There is a high risk that an app will not
          poll the message queue while waiting for  isoburn_disc_write()  to
          return. The pacifier loop usually happens only afterwards.
          So automatic formatting might cause a nervous clueless user.
       */
       ret= isoburn_is_intermediate_dvd_rw(drive, 0);
       if(ret>0 && nwa>0 && nwa <= o->zero_nwa) {
         /* actually this should not happen since such media get recognized
            by isoburn_welcome_media and o->zero_nwa gets set to 0
         */
         sprintf(msg,
        "DVD-RW insufficiently formatted. (Intermediate State, size unknown)");
         isoburn_msgs_submit(o, 0x00060000, msg, 0, "FAILURE", 0);
         sprintf(msg,
                "It might help to first deformat it and then format it again");
         isoburn_msgs_submit(o, 0x00060000, msg, 0, "HINT", 0);
         burn_drive_cancel(drive); /* mark run as failure */
         return;
       }
       /* end of DVD-RW oriented check */

       burn_write_opts_set_start_byte(opts, nwa * (off_t) 2048);
     }
   }
 }

 write_type= burn_write_opts_auto_write_type(opts, disc, reasons, 0);
 if (write_type == BURN_WRITE_NONE) {
    sprintf(msg, "Failed to find a suitable write mode:\n%s", reasons);
    isoburn_msgs_submit(o, 0x00060000, msg, 0, "FAILURE", 0);
    if(o!=NULL)
      o->wrote_well= 0;
    /* To cause a negative reply with burn_drive_wrote_well() */
    burn_drive_cancel(drive);
    return;
 }

 sprintf(reasons, "%d", (int) write_type);
 sprintf(msg, "Write_type = %s\n",
              (write_type == BURN_WRITE_SAO ? "SAO" :
              (write_type == BURN_WRITE_TAO ? "TAO" : reasons)));
 isoburn_msgs_submit(o, 0x00060000, msg, 0, "DEBUG", 0);

#ifdef Hardcoded_cd_rW
 /* <<< A70929 : hardcoded CD-RW with fabricated -msinfo */
 fprintf(stderr, "Setting write address to LBA %d\n", Hardcoded_cd_rw_nwA);
 burn_write_opts_set_start_byte(opts,
				 ((off_t) Hardcoded_cd_rw_nwA) * (off_t) 2048);
#endif

 if(o->truncate) {
   ret= burn_drive_get_drive_role(drive);
   if(ret==2) {
     ret= burn_drive_d_get_adr(drive, adr);
     if(ret>0) {
       ret= lstat(adr, &stbuf);
       if(ret!=-1)
         if(S_ISREG(stbuf.st_mode))
           ret= truncate(adr, nwa * (off_t) 2048);
           /* (result of truncate intentionally ignored) */
     }
   }
 }

 burn_disc_write(opts, disc);
}


void isoburn_drive_release(struct burn_drive *drive, int eject)
{
 int ret;
 struct isoburn *o;

 ret= isoburn_find_emulator(&o, drive, 0);
 if(ret<0)
   return;
 if(o!=NULL) {
   isoburn_destroy(&o, 0);
 }
 burn_drive_release(drive, eject);
}


void isoburn_finish(void)
{
 isoburn_destroy_all(&isoburn_list_start, 0);
 burn_finish();
 iso_finish();
}


int isoburn_needs_emulation(struct burn_drive *drive)
{