libburn/cdrskin/cdrskin.c

/*
 cdrskin.c , Copyright 2006 Thomas Schmitt <scdbackup@gmx.net>
Provided under GPL. See future commitment below.

A cdrecord compatible command line interface for libburn.

This project is neither directed against original cdrecord nor does it exploit
any source code of said program. It rather tries to be an alternative method
to burn CD which is not based on the same code as cdrecord.
See also :  http://scdbackup.sourceforge.net/cdrskin_eng.html

Interested users of cdrecord are encouraged to contribute further option
implementations as they need them. Contributions will get published under GPL
but it is essential that the authors allow a future release under LGPL and/or
BSD license.

There is a script test/cdrecord_spy.sh which may be installed between
the cdrecord command and real cdrecord in order to learn about the options
used by your favorite cdrecord frontend. Edit said script and install it
according to the instructions given inside.

The implementation of an option would probably consist of
- necessary structure members for structs CdrpreskiN and/or CdrskiN
- code in Cdrpreskin_setup() and  Cdrskin_setup() which converts
  argv[i] into CdrpreskiN/CdrskiN members (or into direct actions)
- removal of option from ignore list "ignored_partial_options" resp.
  "ignored_full_options" in Cdrskin_setup()
- functions which implement the option's run time functionality
- eventually calls of those functions in Cdrskin_run()
- changes to be made within Cdrskin_burn() or Cdrskin_blank() or other
  existing methods
See option blank= for an example.

------------------------------------------------------------------------------
About compliance with *strong urge* of API towards burn_drive_scan_and_grab() 

For a more comprehensive example of the advised way to behave with libburn
see  test/libburner.c .
 
cdrskin was the initiator of the whitelist functionality within libburn.
Now it has problems to obviously comply with the new API best practice
presciptions literally. Therefore this explanation:

On start it restricts the library to a single drive if it already knows the
persistent address by option dev= . This is done with a combination of
burn_drive_add_whitelist() and burn_drive_scan(). Not compliant to the
literal strong urge but in fact exactly fulfilling the reason for that
urge in the API: any scanned drive might be opened exclusively after
burn_drive_scan(). It is kernel dependent wether this behavior is on, off
or switchable. The sysdamin will want it on - but only for one drive.

So with dev=... cdrskin complies to the spirit of the strong urge.
Without dev=... it has to leave out the whitelist in order to enable bus
scanning and implicit drive address 0. A tradition of 9 months shall not
be broken. So burns without dev= will stay possible - but harmless only
on single drive systems.

Burns without dev= resp. with dev=number are harmless on multi-drive systems.

This is because Cdrskin_grab_drive() either drops the unwanted drives or
it enforces a restart of the library with the desired drive's persistent
address. This restart then really uses the strongly urged function
burn_drive_scan_and_grab().
Thus, cdrskin complies with the new spirit of API by closing down libburn
or by dropping unused drives as soon as the persistent drive address is
known and the drive is to be used with a long running operation. To my
knowlege all long running operations in cdrskin need a grabbed drive.

This spaghetti approach seems necessary to keep small the impact of new API
urge on cdrskin's stability. cdrskin suffers from having donated the body
parts which have been transplanted to libburn in order to create
 burn_drive_scan_and_grab() . The desired sysadmin friendlyness was already
achieved by most cdrskin runs. The remaining problem situations should now
be defused by releasing any short time grabbed flocks of drives during the
restart of libburn.

------------------------------------------------------------------------------
This program is currently copyright Thomas Schmitt only.
The copyrights of several components of libburn.pykix.org are willfully tangled
at toplevel to form an irrevocable commitment to true open source spirit.
We have chosen the GPL for legal compatibility and clearly express that it
shall not hamper the use of our software by non-GPL applications which show
otherwise the due respect to the open source community.
See toplevel README and cdrskin/README for that commitment.

For a short time, this place showed a promise to release a BSD license on
mere request. I have to retract that promise now, and replace it by the
promise to make above commitment reality in a way that any BSD conformant
usage in due open source spirit will be made possible somehow and in the
particular special case. I will not raise public protest if you spawn yourself
a BSD license from an (outdated) cdrskin.c which still bears that old promise.
Note that this extended commitment is valid only for cdrskin.[ch],
cdrfifo.[ch] and cleanup.[ch], but not for libburn.pykix.org as a whole.

cdrskin is originally inspired by libburn-0.2/test/burniso.c :
(c) Derek Foreman <derek@signalmarketing.com> and Ben Jansens <xor@orodu.net>

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

Compilation within cdrskin-* :

  cd cdrskin
  cc -g -I.. -DCdrskin_build_timestamP='...' \
     -o cdrskin cdrskin.c cdrfifo.c cleanup.c \
     -L../libburn/.libs -lburn -lpthread

or

  cd ..
  cc -g -I. -DCdrskin_build_timestamP='...' \
     -o cdrskin/cdrskin cdrskin/cdrskin.c cdrskin/cdrfifo.c cdrskin/cleanup.c \
     libburn/async.o libburn/crc.o libburn/debug.o libburn/drive.o \
     libburn/file.o libburn/init.o libburn/lec.o libburn/message.o \
     libburn/mmc.o libburn/options.o libburn/sbc.o libburn/sector.o \
     libburn/sg.o libburn/spc.o libburn/source.o libburn/structure.o \
     libburn/toc.o libburn/util.o libburn/write.o \
     -lpthread

*/


/** The official program version */
#ifndef Cdrskin_prog_versioN
#define Cdrskin_prog_versioN "0.2.3"
#endif

/** The source code release timestamp */
#include "cdrskin_timestamp.h"
#ifndef Cdrskin_timestamP
#define Cdrskin_timestamP "-none-given-"
#endif

/** The binary build timestamp is to be set externally by the compiler */
#ifndef Cdrskin_build_timestamP
#define Cdrskin_build_timestamP "-none-given-"
#endif


#ifdef Cdrskin_libburn_versioN 
#undef Cdrskin_libburn_versioN 
#endif

/** use this to accomodate to the CVS version as of Feb 20, 2006
#define Cdrskin_libburn_cvs_A60220_tS 1
*/
#ifdef Cdrskin_libburn_cvs_A60220_tS

#define Cdrskin_libburn_versioN "0.2.tsA60220"
#define Cdrskin_libburn_no_burn_preset_device_opeN 1
#ifndef Cdrskin_oldfashioned_api_usE
#define Cdrskin_oldfashioned_api_usE 1
#endif

#endif /* Cdrskin_libburn_cvs_A60220_tS */


#ifdef Cdrskin_libburn_0_2_2
#define Cdrskin_libburn_versioN "0.2.2"
#define Cdrskin_libburn_from_pykix_svN 1
#endif

#ifdef Cdrskin_libburn_0_2_3
#define Cdrskin_libburn_versioN "0.2.3"
#define Cdrskin_libburn_from_pykix_svN 1
#define Cdrskin_libburn_has_is_enumerablE 1
#define Cdrskin_libburn_has_convert_fs_adR 1
#define Cdrskin_libburn_has_convert_scsi_adR 1
#define Cdrskin_libburn_has_burn_msgS 1
#endif

#ifndef Cdrskin_libburn_versioN
#define Cdrskin_libburn_versioN "0.2.2"
#define Cdrskin_libburn_from_pykix_svN 1
#endif

#ifdef Cdrskin_libburn_from_pykix_svN

#define Cdrskin_libburn_does_ejecT 1
#define Cdrskin_libburn_has_drive_get_adR 1
#define Cdrskin_progress_track_does_worK 1
#define Cdrskin_is_erasable_on_load_does_worK 1
#define Cdrskin_grab_abort_does_worK 1

#ifdef Cdrskin_new_api_tesT

/* put macros under test caveat here */

#endif

#ifdef Cdrskin_oldfashioned_api_usE

/* switch back to pre-0.2.2 libburn usage */;

#endif

#endif /* Cdrskin_libburn_from_pykix_svN */


#ifndef _LARGEFILE_SOURCE
#define _LARGEFILE_SOURCE 1
#endif
#ifndef _FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS 64
#endif


/* These macros activate cdrskin workarounds for deficiencies resp.
   problematic features of libburn which hopefully will change in
   future. */

/** Work around the fact that neither /dev/sg0 (kernel 2.4 + ide-scsi) nor 
    /dev/hdc (kernel 2.6) get ejected by icculus.org/burn */
#ifndef Cdrskin_libburn_does_ejecT
#define Cdrskin_burn_drive_eject_brokeN 1
#endif

/** Work around the fact that after loading media speed report is wrong */
#define Cdrskin_atip_speed_brokeN 1

/** Work around the fact that burn_drive_get_status() always reports to do
    track 0 in icculus.org/burn */
#ifndef Cdrskin_progress_track_does_worK
#define Cdrskin_progress_track_brokeN 1
#endif

/** Work around the fact that a drive interrupted at burn_drive_grab() never
    leaves status BURN_DRIVE_GRABBING in icculus.org/burn */
#ifndef Cdrskin_grab_abort_does_worK
#define Cdrskin_grab_abort_brokeN 1
#endif

/** Work around the fact that a freshly loaded tray with media reports
    arbitrary media erasability in icculuc.org/burn */
#ifndef Cdrskin_is_erasable_on_load_does_worK
#define Cdrskin_is_erasable_on_load_is_brokeN 1
#endif

/** http://libburn.pykix.org/ticket/41 reports of big trouble without 
    padding any track to a full sector
*/
#define Cdrskin_all_tracks_with_sector_paD 1


/** A macro which is able to eat up a function call like printf() */
#ifdef Cdrskin_extra_leaN
#define ClN(x) 
#else
#define ClN(x) x
#endif


/** Verbosity level for pacifying progress messages */
#define Cdrskin_verbose_progresS 1

/** Verbosity level for command recognition and execution logging */
#define Cdrskin_verbose_cmD 2

/** Verbosity level for reporting of debugging messages */
#define Cdrskin_verbose_debuG 3


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

#include <libburn/libburn.h>

#include "cleanup.h"


/** The size of a string buffer for pathnames and similar texts */
#define Cdrskin_strleN 4096

/** The maximum length +1 of a drive address */
#ifndef Cdrskin_oldfashioned_api_usE
#define Cdrskin_adrleN BURN_DRIVE_ADR_LEN
#else
#define Cdrskin_adrleN 80
#endif


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

/* Imported from scdbackup-0.8.5/src/cd_backup_planer.c */

/** Macro for creation of arrays of objects (or single objects) */
#define TSOB_FELD(typ,anz) (typ *) malloc((anz)*sizeof(typ));


/** Convert a text so that eventual characters special to the shell are
    made literal. Note: this does not make a text terminal-safe !
    @param in_text The text to be converted
    @param out_text The buffer for the result. 
                    It should have size >= strlen(in_text)*5+2
    @param flag Unused yet
    @return For convenience out_text is returned
*/
char *Text_shellsafe(char *in_text, char *out_text, int flag)
{
 int l,i,w=0;

 /* enclose everything by hard quotes */
 l= strlen(in_text);
 out_text[w++]= '\'';
 for(i=0;i<l;i++){
   if(in_text[i]=='\''){
     /* escape hard quote within the text */
     out_text[w++]= '\'';
     out_text[w++]= '"';
     out_text[w++]= '\'';
     out_text[w++]= '"';
     out_text[w++]= '\'';
   } else {
     out_text[w++]= in_text[i];
   }
 }
 out_text[w++]= '\'';
 out_text[w++]= 0;
 return(out_text);
}


/** Convert a text into a number of type double and multiply it by unit code
    [kmgtpe] (2^10 to 2^60) or [s] (2048). (Also accepts capital letters.)
    @param text Input like "42", "2k", "3.14m" or "-1g"
    @param flag Bitfield for control purposes:
                bit0= return -1 rathern than 0 on failure
    @return The derived double value
*/
double Scanf_io_size(char *text, int flag)
/*
 bit0= default value -1 rather than 0
*/
{
 int c;
 double ret= 0.0;

 if(flag&1)
   ret= -1.0;
 if(text[0]==0)
   return(ret);
 sscanf(text,"%lf",&ret);
 c= text[strlen(text)-1];
 if(c=='k' || c=='K') ret*= 1024.0;
 if(c=='m' || c=='M') ret*= 1024.0*1024.0;
 if(c=='g' || c=='G') ret*= 1024.0*1024.0*1024.0;
 if(c=='t' || c=='T') ret*= 1024.0*1024.0*1024.0*1024.0;
 if(c=='p' || c=='P') ret*= 1024.0*1024.0*1024.0*1024.0*1024.0;
 if(c=='e' || c=='E') ret*= 1024.0*1024.0*1024.0*1024.0*1024.0*1024.0;
 if(c=='s' || c=='S') ret*= 2048.0;
 return(ret);
}


/** Return a double representing seconds and microseconds since 1 Jan 1970 */
double Sfile_microtime(int flag)
{
 struct timeval tv;
 struct timezone tz;
 gettimeofday(&tv,&tz);
 return((double) (tv.tv_sec+1.0e-6*tv.tv_usec));
}


#ifndef Cdrskin_extra_leaN

/** Read a line from fp and strip LF or CRLF */
char *Sfile_fgets(char *line, int maxl, FILE *fp)
{
int l;
char *ret;
 ret= fgets(line,maxl,fp);
 if(ret==NULL) return(NULL);
 l= strlen(line);
 if(l>0) if(line[l-1]=='\r') line[--l]= 0;
 if(l>0) if(line[l-1]=='\n') line[--l]= 0;
 if(l>0) if(line[l-1]=='\r') line[--l]= 0;
 return(ret);
}


/** Destroy a synthetic argument array */
int Sfile_destroy_argv(int *argc, char ***argv, int flag)
{
 int i;

 if(*argc>0 && *argv!=NULL){
   for(i=0;i<*argc;i++){
     if((*argv)[i]!=NULL) 
       free((*argv)[i]);
   }
   free((char *) *argv);
 }
 *argc= 0;
 *argv= NULL;
 return(1);
}


/** Read a synthetic argument array from a list of files.
    @param progname The content for argv[0]
    @param filenames The paths of the filex from where to read
    @param filenamecount The number of paths in filenames
    @param argc Returns the number of read arguments (+1 for progname)
    @param argv Returns the array of synthetic arguments
    @param argidx Returns source file indice of argv[] items
    @param arglno Returns source file line numbers of argv[] items
    @param flag Bitfield for control purposes:
                bit0= read progname as first argument from line
                bit1= just release argument array argv and return
                bit2= tolerate failure to open file
    @return 1=ok , 0=cannot open file , -1=cannot create memory objects
*/
int Sfile_multi_read_argv(char *progname, char **filenames, int filename_count,
                          int *argc, char ***argv, int **argidx, int **arglno,
                          int flag)
{
 int ret,i,pass,maxl=0,l,argcount=0,line_no;
 char buf[Cdrskin_strleN];
 FILE *fp= NULL;

 Sfile_destroy_argv(argc,argv,0);
 if(flag&2)
   return(1);
 if((*argidx)!=NULL)
   free((char *) *argidx);
 if((*arglno)!=NULL)
   free((char *) *arglno);
 *argidx= *arglno= NULL;

 for(pass=0;pass<2;pass++) {
   if(!(flag&1)){
     argcount= 1;
     if(pass==0)
       maxl= strlen(progname)+1;
     else {
      (*argv)[0]= (char *) malloc(strlen(progname)+1);
      if((*argv)[0]==NULL)
         {ret= -1; goto ex;}
       strcpy((*argv)[0],progname);
     }
   } else {
     argcount= 0;
     if(pass==0)
       maxl= 1;
   }
   for(i=0; i<filename_count;i++) {
     if(strlen(filenames[i])==0)
   continue;
     fp= fopen(filenames[i],"rb");
     if(fp==NULL) {
       if(flag&4)
   continue;
       {ret= 0; goto ex;}
     }

#ifdef Cdrskin_new_api_tesT
     if(pass>0)
       fprintf(stderr,"cdrskin: DEBUG : Reading arguments from file '%s'\n",
                      filenames[i]);
#endif

     line_no= 0;
     while(Sfile_fgets(buf,sizeof(buf)-1,fp)!=NULL) {
       line_no++;
       l= strlen(buf);
       if(pass==0){
         if(l>maxl) 
           maxl= l;
       } else {
         if(argcount >= *argc)
     break;
         (*argv)[argcount]= (char *) malloc(l+1);
         if((*argv)[argcount]==NULL)
           {ret= -1; goto ex;}
         strcpy((*argv)[argcount],buf);
         (*argidx)[argcount]= i;
         (*arglno)[argcount]= line_no;
       }
       argcount++;
     }
     fclose(fp); fp= NULL;
   }
   if(pass==0){
     *argc= argcount;
     if(argcount>0) {
       *argv= (char **) malloc(argcount*sizeof(char *));
       *argidx= (int *) malloc(argcount*sizeof(int));
       *arglno= (int *) malloc(argcount*sizeof(int));
       if(*argv==NULL || *argidx==NULL || *arglno==NULL)
         {ret= -1; goto ex;}
     }
     for(i=0;i<*argc;i++) {
       (*argv)[i]= NULL;
       (*argidx)[i]= -1;
       (*arglno)[i]= -1;
     }
   }     
 }

 ret= 1;
ex:;
 if(fp!=NULL)
   fclose(fp);
 return(ret);
}


/** Combine environment variable HOME with given filename
    @param filename Address relative to $HOME
    @param fileadr Resulting combined address
    @param fa_size Size of array fileadr
    @param flag Unused yet
    @return 1=ok , 0=no HOME variable , -1=result address too long
*/
int Sfile_home_adr_s(char *filename, char *fileadr, int fa_size, int flag)
{
 char *home;

 strcpy(fileadr,filename);
 home= getenv("HOME");
 if(home==NULL)
   return(0);
 if(strlen(home)+strlen(filename)+1>=fa_size)
   return(-1);
 strcpy(fileadr,home);
 if(filename[0]!=0){
   strcat(fileadr,"/");
   strcat(fileadr,filename);
 }
 return(1);
}


#endif /* ! Cdrskin_extra_leaN */


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

/** Address translation table for users/applications which do not look
   for the output of -scanbus but guess a Bus,Target,Lun on their own.
*/

/** The maximum number of entries in the address translation table */
#define Cdradrtrn_leN 256

/** The address prefix which will prevent translation */
#define Cdrskin_no_transl_prefiX "LITERAL_ADR:"


struct CdradrtrN {
 char *from_address[Cdradrtrn_leN];
 char *to_address[Cdradrtrn_leN];
 int fill_counter;
};


#ifndef Cdrskin_extra_leaN

/** Create a device address translator object */
int Cdradrtrn_new(struct CdradrtrN **trn, int flag)
{
 struct CdradrtrN *o;
 int i;

 (*trn)= o= TSOB_FELD(struct CdradrtrN,1);
 if(o==NULL)
   return(-1);
 for(i= 0;i<Cdradrtrn_leN;i++) {
   o->from_address[i]= NULL;
   o->to_address[i]= NULL;
 }
 o->fill_counter= 0;
 return(1);
}


/** Release from memory a device address translator object */
int Cdradrtrn_destroy(struct CdradrtrN **o, int flag)
{
 int i;
 struct CdradrtrN *trn;
 
 trn= *o;
 if(trn==NULL)
   return(0);
 for(i= 0;i<trn->fill_counter;i++) {
   if(trn->from_address[i]!=NULL)
     free(trn->from_address[i]);
   if(trn->to_address[i]!=NULL)
     free(trn->to_address[i]);
 }
 free((char *) trn);
 *o= NULL;
 return(1);
}


/** Add a translation pair to the table 
    @param trn The translator which shall learn
    @param from The user side address
    @param to The cdrskin side address
    @param flag Bitfield for control purposes:
                bit0= "from" contains from+to address, to[0] contains delimiter
*/
int Cdradrtrn_add(struct CdradrtrN *trn, char *from, char *to, int flag)
{
 char buf[2*Cdrskin_adrleN+1],*from_pt,*to_pt;
 int cnt;

 cnt= trn->fill_counter;
 if(cnt>=Cdradrtrn_leN)
   return(-1);
 if(flag&1) {
   if(strlen(from)>=sizeof(buf))
     return(0);
   strcpy(buf,from);
   to_pt= strchr(buf,to[0]);
   if(to_pt==NULL)
     return(0);
   *(to_pt)= 0;
   from_pt= buf;
   to_pt++;
 } else {
   from_pt= from;
   to_pt= to;
 }
 if(strlen(from)>=Cdrskin_adrleN || strlen(to)>=Cdrskin_adrleN)
   return(0);
 trn->from_address[cnt]= malloc(strlen(from_pt)+1);
 trn->to_address[cnt]= malloc(strlen(to_pt)+1);
 if(trn->from_address[cnt]==NULL ||
    trn->to_address[cnt]==NULL)
   return(-2);
 strcpy(trn->from_address[cnt],from_pt);
 strcpy(trn->to_address[cnt],to_pt);
 trn->fill_counter++;
 return(1);
}


/** Apply eventual device address translation
    @param trn The translator 
    @param from The address from which to translate
    @param driveno With backward translation only: The libburn drive number
    @param to The result of the translation
    @param flag Bitfield for control purposes:
                bit0= translate backward
    @return <=0 error, 1=no translation found, 2=translation found,
            3=collision avoided
*/
int Cdradrtrn_translate(struct CdradrtrN *trn, char *from, int driveno,
                        char to[Cdrskin_adrleN], int flag)
{
 int i,ret= 1;
 char *adr;

 to[0]= 0;
 adr= from;
 if(flag&1)
   goto backward;

 if(strncmp(adr,Cdrskin_no_transl_prefiX,
            strlen(Cdrskin_no_transl_prefiX))==0) {
   adr= adr+strlen(Cdrskin_no_transl_prefiX);
   ret= 2;
 } else {
   for(i=0;i<trn->fill_counter;i++)
     if(strcmp(adr,trn->from_address[i])==0)
   break;
   if(i<trn->fill_counter) {
     adr= trn->to_address[i];
     ret= 2;
   }
 }
 if(strlen(adr)>=Cdrskin_adrleN)
   return(-1);
 strcpy(to,adr);
 return(ret);

backward:;
 if(strlen(from)>=Cdrskin_adrleN)
   sprintf(to,"%s%d",Cdrskin_no_transl_prefiX,driveno);
 else
   strcpy(to,from);
 for(i=0;i<trn->fill_counter;i++)
   if(strcmp(from,trn->to_address[i])==0 &&
      strlen(trn->from_address[i])<Cdrskin_adrleN)
 break;
 if(i<trn->fill_counter) {
   ret= 2;
   strcpy(to,trn->from_address[i]);
 } else {
   for(i=0;i<trn->fill_counter;i++)
     if(strcmp(from,trn->from_address[i])==0)
   break;
   if(i<trn->fill_counter)
     if(strlen(from)+strlen(Cdrskin_no_transl_prefiX)<Cdrskin_adrleN) {
       ret= 3;
       sprintf(to,"%s%s",Cdrskin_no_transl_prefiX,from);
     }
 }
 return(ret);
}

#endif /* Cdrskin_extra_leaN */


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


#ifndef Cdrskin_extra_leaN

/* Program is to be linked with cdrfifo.c */
#include "cdrfifo.h"

#else /* !  Cdrskin_extra_leaN */

/* Dummy */

struct CdrfifO {
 int dummy;
};

#endif /* Cdrskin_extra_leaN */


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

/** cdrecord pads up to 600 kB in any case. 
    libburn yields blank result on tracks <~ 600 kB */
static double Cdrtrack_minimum_sizE= 600*1024;


/** This structure represents a track resp. a data source */
struct CdrtracK {

 struct CdrskiN *boss;
 int trackno;
  
 char source_path[Cdrskin_strleN];
 int source_fd;
 int is_from_stdin;
 double fixed_size;
 double padding;
 int set_by_padsize;
 int sector_pad_up; /* enforce single sector padding */
 int track_type;

 /** Optional fifo between input fd and libburn. It uses a pipe(2) to transfer
     data to libburn. 
 */
 int fifo_enabled;
 /** The fifo object knows the real input fd and the fd[1] of the pipe. */
 struct CdrfifO *fifo;
 /** fd[0] of the fifo pipe. This is from where libburn reads its data. */
 int fifo_outlet_fd;
 int fifo_size;
 int fifo_start_empty;

 struct burn_track *libburn_track;

};

int Cdrtrack_destroy(struct CdrtracK **o, int flag);


/** Create a track resp. data source object.
    @param track Returns the address of the new object.
    @param boss The cdrskin control object (corresponds to session)
    @param trackno The index in the cdrskin tracklist array (is not constant)
    @param flag Bitfield for control purposes:
                bit0= set fifo_start_empty to 1
                bit1= track is originally stdin
*/
int Cdrtrack_new(struct CdrtracK **track, struct CdrskiN *boss,
                 int trackno, int flag)
{
 struct CdrtracK *o;
 int ret;
 int Cdrskin_get_source(struct CdrskiN *skin, char *source_path,
                        double *fixed_size, double *padding,
                        int *set_by_padsize, int *track_type, int flag);
 int Cdrskin_get_fifo_par(struct CdrskiN *skin, int *fifo_enabled,
                          int *fifo_size, int *fifo_start_empty, int flag);

 (*track)= o= TSOB_FELD(struct CdrtracK,1);
 if(o==NULL)
   return(-1);
 o->boss= boss;
 o->trackno= trackno;
 o->source_path[0]= 0;
 o->source_fd= -1;
 o->is_from_stdin= !!(flag&2);
 o->fixed_size= 0.0;
 o->padding= 0.0;
 o->set_by_padsize= 0;
 o->sector_pad_up= Cdrskin_all_tracks_with_sector_paD;
 o->track_type= BURN_MODE1;
 o->fifo_enabled= 0;
 o->fifo= NULL;
 o->fifo_outlet_fd= -1;
 o->fifo_size= 0;
 o->fifo_start_empty= 0;
 o->libburn_track= NULL;
 ret= Cdrskin_get_source(boss,o->source_path,&(o->fixed_size),&(o->padding),
                         &(o->set_by_padsize),&(o->track_type),0);
 if(ret<=0)
   goto failed;

#ifndef Cdrskin_extra_leaN
 ret= Cdrskin_get_fifo_par(boss, &(o->fifo_enabled),&(o->fifo_size),
                           &(o->fifo_start_empty),0);
 if(ret<=0)
   goto failed;
#endif /* ! Cdrskin_extra_leaN */

 if(flag&1)
   o->fifo_start_empty= 1;
 return(1);
failed:;
 Cdrtrack_destroy(track,0);
 return(-1);
}


/** Release from memory a track object previously created by Cdrtrack_new() */
int Cdrtrack_destroy(struct CdrtracK **o, int flag)
{
 struct CdrtracK *track;

 track= *o;
 if(track==NULL)
   return(0);

#ifndef Cdrskin_extra_leaN
 Cdrfifo_destroy(&(track->fifo),0);
#endif

 if(track->libburn_track!=NULL)
   burn_track_free(track->libburn_track);
 free((char *) track);
 *o= NULL;
 return(1);
}


int Cdrtrack_get_size(struct CdrtracK *track, double *size, double *padding,
                      int flag)
{
 *size= track->fixed_size;
 *padding= track->padding;
 return(1);
}


int Cdrtrack_get_fifo(struct CdrtracK *track, struct CdrfifO **fifo, int flag)
{
 *fifo= track->fifo;
 return(1);
}


/** Deliver an open file descriptor corresponding to the source path of track.
    @return <=0 error, 1 success
*/
int Cdrtrack_open_source_path(struct CdrtracK *track, int *fd, int flag)
{
 if(track->source_path[0]=='-' && track->source_path[1]==0)
   *fd= 0;
 else if(track->source_path[0]=='#' && 
         (track->source_path[1]>='0' && track->source_path[1]<='9'))
   *fd= atoi(track->source_path+1);
 else {
   *fd= open(track->source_path,O_RDONLY);
   if(*fd==-1) {
     fprintf(stderr,"cdrskin: failed to open source address '%s'\n",
             track->source_path);
     fprintf(stderr,"cdrskin: errno=%d , \"%s\"\n",errno,
                    errno==0?"-no error code available-":strerror(errno));
   } else {
     if(track->fixed_size<=0) { 
       struct stat stbuf;
       if(fstat(*fd,&stbuf)!=-1)
         track->fixed_size= stbuf.st_size;
     }
   }
 }
 if(track->fixed_size<Cdrtrack_minimum_sizE && *fd>=0) {
   fprintf(stderr,
           "cdrskin: NOTE : Enforcing minimum track size of %.f bytes\n",
           Cdrtrack_minimum_sizE);
   track->fixed_size= Cdrtrack_minimum_sizE;
 }
 track->source_fd= *fd;
 return(*fd>=0);
}


#ifndef Cdrskin_extra_leaN

/** Install a fifo object between data source and libburn.
    Its parameters are known to track.
    @param outlet_fd Returns the filedescriptor of the fifo outlet.
    @param previous_fifo Object address for chaining or follow-up attachment.
    @param flag Bitfield for control purposes:
                bit0= Debugging verbosity
                bit1= Do not create and attach a new fifo 
                      but attach new follow-up fd pair to previous_fifo
    @return <=0 error, 1 success
*/
int Cdrtrack_attach_fifo(struct CdrtracK *track, int *outlet_fd, 
                         struct CdrfifO *previous_fifo, int flag)
{
 struct CdrfifO *ff;
 int source_fd,pipe_fds[2],ret;

 *outlet_fd= -1;
 if(track->fifo_size<=0)
   return(2);
 ret= Cdrtrack_open_source_path(track,&source_fd,0);
 if(ret<=0)
   return(ret);
 if(pipe(pipe_fds)==-1)
   return(0);

 Cdrfifo_destroy(&(track->fifo),0);
 if(flag&2) {
   ret= Cdrfifo_attach_follow_up_fds(previous_fifo,source_fd,pipe_fds[1],0);
   if(ret<=0)
    return(ret);
 } else {
   ret= Cdrfifo_new(&ff,source_fd,pipe_fds[1],2048,track->fifo_size,0);
   if(ret<=0)
     return(ret);
   if(previous_fifo!=NULL)
     Cdrfifo_attach_peer(previous_fifo,ff,0);
   track->fifo= ff;
 }
 track->fifo_outlet_fd= pipe_fds[0];
 if(flag&1)
   printf(
        "cdrskin_debug: track %d fifo replaced source_address '%s' by '#%d'\n",
        track->trackno+1,track->source_path,track->fifo_outlet_fd);
 sprintf(track->source_path,"#%d",track->fifo_outlet_fd);
 track->source_fd= track->fifo_outlet_fd;
 *outlet_fd= track->fifo_outlet_fd;
 return(1);
}


/** Read data into the fifo until either it is full or the data source is
    exhausted.
    @return <=0 error, 1 success
*/
int Cdrtrack_fill_fifo(struct CdrtracK *track, int flag)
{