New option fallback_program=

cdrskin/cdrskin.1

@@ -777,6 +777,33 @@ Both, write_start_address and direct_write_amount size must be aligned to a
 media dependend transaction size. With DVD-RAM and DVD+RW this is 2k, with
 overwriteable DVD-RW it is 32k.
 .TP
+.BI fallback_program= command
+Set a command name to be executed if cdrskin encounters a known cdrecord
+option which it does not yet support. If a non-empty command is given with
+fallback_program=, and if no essential options are given which are specific
+to cdrskin, then cdrskin will delegate the job to said command.
+.br
+The natural commands to be given are cdrecord or wodim but one may well submit
+the address of an own program. 
+.br
+The fallback programm will get all arguments of cdrskin which do not match
+the shell patterns --?* or *_*=* . This eventually suppresses path names of
+track sources which happen to match those patterns. The options from the
+startup files are not handed to the fallback program.
+.br
+Fallback program execution is disabled if cdrskin is run setuid and not
+option --allow_setuid is given. In general, the drive's device files and the
+involved programs should be set so that each program runs under its advised
+conditions. (E.g. cdrskin as member of group floppy, cdrecord setuid root.)
+.br
+Two alias names for cdrskin are predefined with default fallback programs:
+.br
+.B unicord
+implies fallback_program=cdrecord
+.br
+.B codim
+implies fallback_program=wodim
+.TP
 .BI fifo_start_at= size
 Do not wait for full fifo but start burning as soon as the given number
 of bytes is read. This option may be helpful to bring the average throughput

cdrskin/cdrskin.c

@@ -1721,8 +1721,14 @@ struct CdrpreskiN {
 
 #endif /* ! Cdrskin_extra_leaN */
 
-};
+ /* The eventual name of a program to be executed if demands_cdrecord_caps
+    is >0 and demands_cdrskin_caps is <=0
+ */
+ char fallback_program[Cdrskin_strleN];
+ int demands_cdrecord_caps;
+ int demands_cdrskin_caps;
 
+};
 
 
 /** Create a preliminary cdrskin program run control object. It will become
@@ -1778,6 +1784,9 @@ int Cdrpreskin_new(struct CdrpreskiN **preskin, int flag)
  o->pre_arglno= NULL;
 #endif /* ! Cdrskin_extra_leaN */
 
+ o->fallback_program[0]= 0;
+ o->demands_cdrecord_caps= 0;
+ o->demands_cdrskin_caps= 0;
  return(1);
 }
 
@@ -2081,6 +2090,18 @@ return:
    fprintf(stderr,"cdrskin: SORRY : No options given. Try option  --help\n");
    return(0);
  }
+
+ /* The two predefined fallback personalities are triggered by the progname */
+ value_pt= strrchr(argv[0],'/');
+ if(value_pt==NULL)
+   value_pt= argv[0];
+ else
+   value_pt++;
+ if(strcmp(value_pt,"unicord")==0)
+   strcpy(o->fallback_program,"cdrecord");
+ else if(strcmp(value_pt,"codim")==0)
+   strcpy(o->fallback_program,"wodim");
+
  for (i= 1;i<argc;i++) {
 
    if(strcmp(argv[i],"--abort_handler")==0) {
@@ -2131,6 +2152,7 @@ return:
 
    } else if(strcmp(argv[i],"--demand_a_drive")==0) {
      o->scan_demands_drive= 1;
+     o->demands_cdrskin_caps= 1;
 
    } else if(strcmp(argv[i],"--devices")==0) {
 #ifndef Cdrskin_extra_leaN
@@ -2141,8 +2163,10 @@ return:
 #endif /* ! Cdrskin_extra_leaN */
 
      o->no_whitelist= 1;
+     o->demands_cdrskin_caps= 1;
 
    } else if(strncmp(argv[i],"dev_translation=",16)==0) {
+     o->demands_cdrskin_caps= 1;
 
 #ifndef Cdrskin_extra_leaN
 
@@ -2273,6 +2297,7 @@ set_dev:;
        o->drive_scsi_dev_family= 0;
    } else if(strcmp(argv[i],"--drive_scsi_exclusive")==0) {
      o->drive_exclusive= 2;
+     o->demands_cdrskin_caps= 1;
 
    } else if(strcmp(argv[i],"driveropts=help")==0 ||
              strcmp(argv[i],"-driveropts=help")==0) {
@@ -2522,6 +2547,9 @@ see_cdrskin_eng_html:;
    } else if(strcmp(argv[i],"--ignore_signals")==0) {
      o->abort_handler= 2;
 
+   } else if(strncmp(argv[i],"fallback_program=",17)==0) {
+     strcpy(o->fallback_program,argv[i]+17);
+
    } else if(strcmp(argv[i],"--no_abort_handler")==0) {
      o->abort_handler= 0;
 
@@ -2530,6 +2558,7 @@ see_cdrskin_eng_html:;
 
    } else if(strcmp(argv[i],"--old_pseudo_scsi_adr")==0) {
      o->old_pseudo_scsi_adr= 1;
+     o->demands_cdrskin_caps= 1;
 
    } else if(strcmp(argv[i],"--no_rc")==0) {
      if(i!=1)
@@ -2686,6 +2715,61 @@ ex:;
 }
 
 
+int Cdrpreskin_fallback(struct CdrpreskiN *preskin, int argc, char **argv)
+{
+ char **hargv= NULL;
+ int i, wp= 1;
+ char *ept, *upt;
+
+ if(getuid()!=geteuid() && !preskin->allow_setuid) {
+   fprintf(stderr,
+     "cdrskin: SORRY : uid and euid differ. Will not start external fallback program.\n");
+   fprintf(stderr,
+     "cdrskin: HINT : Consider to allow rw-access to the writer device and\n");
+   fprintf(stderr,
+     "cdrskin: HINT : to run cdrskin under your normal user identity.\n");
+   fprintf(stderr,
+    "cdrskin: HINT : Option  --allow_setuid  disables this safety check.\n");
+   goto failure;
+ }
+ fprintf(stderr,"cdrskin: --------------------------------------------------------------------\n");
+ fprintf(stderr,"cdrskin: Starting fallback program:\n");
+ hargv= TSOB_FELD(char *,argc+1);
+ if(hargv==NULL)
+   goto failure;
+ hargv[0]= strdup(preskin->fallback_program);
+ if(argv[0]==NULL)
+   goto failure; 
+ fprintf(stderr,"         %s", hargv[0]);
+ for(i= 1; i<argc; i++) {
+   /* filter away all cdrskin specific options :  --?*  and  *_*=*   */
+   if(argv[i][0]=='-' && argv[i][1]=='-' && argv[i][2])
+ continue;
+   ept= strchr(argv[i],'=');
+   if(ept!=NULL) {
+     upt= strchr(argv[i],'_');
+     if(upt!=NULL && upt<ept)
+ continue;
+   }
+   hargv[wp]= strdup(argv[i]);
+   if(hargv[wp]==NULL)
+     goto failure;
+   fprintf(stderr,"  %s", hargv[wp]);
+   wp++;
+ }
+ hargv[wp]= NULL;
+ fprintf(stderr,"\n");
+ fprintf(stderr,"cdrskin: --------------------------------------------------------------------\n");
+ execvp(hargv[0], hargv);
+failure:;
+ fprintf(stderr,"cdrskin: FATAL : Cannot start fallback program '%s'\n",
+         hargv[0]);
+ fprintf(stderr,"cdrskin: errno=%d  \"%s\"\n",
+         errno, (errno > 0 ? strerror(errno) : "unidentified error"));
+ exit(15);
+}
+
+
 /* --------------------------------------------------------------------- */
 
 
@@ -3009,7 +3093,6 @@ int Cdrskin_new(struct CdrskiN **skin, struct CdrpreskiN *preskin, int flag)
  o->use_data_image_size= 0;
  o->media_does_multi= 0;
  o->media_is_overwriteable= 0;
-
  o->grow_overwriteable_iso= 0;
  memset(o->overwriteable_iso_head,0,sizeof(o->overwriteable_iso_head));
 
@@ -6483,8 +6566,12 @@ int Cdrskin_setup(struct CdrskiN *skin, int argc, char **argv, int flag)
        goto no_volunteer;
    if(0) {
 no_volunteer:;
-     fprintf(stderr,"cdrskin: NOTE : ignoring unimplemented option : '%s'\n",
+     skin->preskin->demands_cdrecord_caps= 1;
-                    argv[i]);
+     if(skin->preskin->fallback_program[0])
+       fprintf(stderr,"cdrskin: NOTE : Unimplemented option: '%s'\n",argv[i]);
+     else  
+       fprintf(stderr,"cdrskin: NOTE : ignoring unimplemented option : '%s'\n",
+               argv[i]);
      fprintf(stderr,
        "cdrskin: NOTE : option is waiting for a volunteer to implement it.\n");
  continue;
@@ -6582,22 +6669,27 @@ set_blank:;
        skin->do_blank= 1;
        skin->blank_format_type= 1|(1<<8);
        skin->blank_format_size= 128*1024*1024;
+       skin->preskin->demands_cdrskin_caps= 1;
      } else if(strcmp(cpt,"format_overwrite_full")==0) { 
        skin->do_blank= 1;
        skin->blank_format_type= 1|(1<<10);
        skin->blank_format_size= 0;
+       skin->preskin->demands_cdrskin_caps= 1;
      } else if(strcmp(cpt,"format_overwrite_quickest")==0) { 
        skin->do_blank= 1;
        skin->blank_format_type= 1;
        skin->blank_format_size= 0;
+       skin->preskin->demands_cdrskin_caps= 1;
      } else if(strcmp(cpt,"deformat_sequential")==0) {
        skin->do_blank= 1;
        skin->blank_format_type= 2;
        skin->blank_fast= 0;
+       skin->preskin->demands_cdrskin_caps= 1;
      } else if(strcmp(cpt,"deformat_sequential_quickest")==0) {
        skin->do_blank= 1;
        skin->blank_format_type= 2;
        skin->blank_fast= 1;
+       skin->preskin->demands_cdrskin_caps= 1;
      } else if(strcmp(cpt,"help")==0) { 
        /* is handled in Cdrpreskin_setup() */;
  continue;
@@ -6628,11 +6720,9 @@ set_blank:;
    } else if(strcmp(argv[i],"--devices")==0) {
      skin->do_devices= 1;
 
-
 #ifndef Cdrskin_extra_leaN
 
    } else if(strncmp(argv[i],"dev_translation=",16)==0) {
-
      if(argv[i][16]==0) {
        fprintf(stderr,
          "cdrskin: FATAL : dev_translation= : missing separator character\n");
@@ -6669,6 +6759,7 @@ set_blank:;
      if(skin->direct_write_amount>=0.0) {
        skin->do_direct_write= 1;
        printf("cdrskin: NOTE : Direct writing will only use first track source and no fifo.\n");
+       skin->preskin->demands_cdrskin_caps= 1;
      } else
        skin->do_direct_write= 0;
 
@@ -6805,6 +6896,7 @@ fs_equals:;
    } else if(strncmp(argv[i],"grab_drive_and_wait=",20)==0) {
      value_pt= argv[i]+20;
      grab_and_wait_value= Scanf_io_size(value_pt,0);
+     skin->preskin->demands_cdrskin_caps= 1;
 
    } else if(strncmp(argv[i],"-gracetime=",11)==0) {
      value_pt= argv[i]+11;
@@ -6819,6 +6911,7 @@ gracetime_equals:;
    } else if(strncmp(argv[i],"--grow_overwriteable_iso",24)==0) {
      skin->grow_overwriteable_iso= 1;
      skin->use_data_image_size= 1;
+     skin->preskin->demands_cdrskin_caps= 1;
 #endif /* Cdrskin_libburn_has_random_access_rW */
 #endif /* Cdrskin_libburn_has_get_multi_capS */
      
@@ -6875,6 +6968,9 @@ gracetime_equals:;
        printf("%s\n",ignored_full_options[k]);
      printf("\n");
 
+   } else if(strncmp(argv[i],"fallback_program=",17)==0) {
+     /* is handled in Cdrpreskin_setup() */;
+
    } else if(strcmp(argv[i],"-load")==0) {
      skin->do_load= 1;
 
@@ -6959,6 +7055,7 @@ minbuf_equals:;
                 value_pt);
        }
      }
+     skin->preskin->demands_cdrskin_caps= 1;
 #else
      fprintf(stderr,
           "cdrskin: SORRY : Option modesty_on_drive= is not available yet.\n");
@@ -7055,6 +7152,7 @@ set_padsize:;
      if(skin->verbosity>=Cdrskin_verbose_cmD)
        ClN(printf(
 "cdrskin: --single_track : will only accept last argument as track source\n"));
+     skin->preskin->demands_cdrskin_caps= 1;
 
    } else if(strncmp(argv[i],"-speed=",7)==0) {
      value_pt= argv[i]+7;
@@ -7070,6 +7168,8 @@ set_speed:;
        fprintf(stderr,"cdrskin: FATAL : speed= must be -1, 0 or at least 1\n");
        return(0);
      }
+     if(skin->x_speed<0)
+       skin->preskin->demands_cdrskin_caps= 1;
 
      /* >>> cdrecord speed=0 -> minimum speed , libburn -> maximum speed */;
 
@@ -7098,6 +7198,7 @@ set_speed:;
      skin->tao_to_sao_tsize= Scanf_io_size(argv[i]+17,0);
      if(skin->tao_to_sao_tsize>Cdrskin_tracksize_maX)
        goto track_too_large;
+     skin->preskin->demands_cdrskin_caps= 1;
 
 #ifndef Cdrskin_extra_leaN
      if(skin->verbosity>=Cdrskin_verbose_cmD)
@@ -7112,6 +7213,7 @@ set_speed:;
 #ifdef Cdrskin_libburn_has_get_spacE
    } else if(strcmp(argv[i],"--tell_media_space")==0) {
      skin->tell_media_space= 1;
+     skin->preskin->demands_cdrskin_caps= 1;
 #endif
 
    } else if(strcmp(argv[i],"-toc")==0) {
@@ -7150,6 +7252,7 @@ track_too_large:;
      if(skin->verbosity>=Cdrskin_verbose_cmD)
        ClN(printf("cdrskin: write start address : %.f\n",
                   skin->write_start_address));
+     skin->preskin->demands_cdrskin_caps= 1;
 
    } else if( i==argc-1 ||
              (skin->single_track==0 && strchr(argv[i],'=')==NULL 
@@ -7225,14 +7328,28 @@ track_too_large:;
      skin->fixed_size= 0;
    } else {
 ignore_unknown:;
-     fprintf(stderr,"cdrskin: NOTE : ignoring unknown option : '%s'\n",
+     if(skin->preskin->fallback_program[0])
-                    argv[i]);
+       fprintf(stderr,"cdrskin: NOTE : Unknown option : '%s'\n",argv[i]);
+     else
+       fprintf(stderr,"cdrskin: NOTE : ignoring unknown option : '%s'\n",
+               argv[i]);
+     skin->preskin->demands_cdrecord_caps= 1;
    }
  }
 
  if(flag&1) /* no finalizing yet */
    return(1);
 
+ if(skin->preskin->fallback_program[0] &&
+    skin->preskin->demands_cdrecord_caps>0 &&
+    skin->preskin->demands_cdrskin_caps<=0) {
+   fprintf(stderr,"cdrskin: NOTE : Unsupported options found.\n");	
+   fprintf(stderr,
+           "cdrskin: NOTE : Will delegate job to fallback program '%s'.\n",
+           skin->preskin->fallback_program);
+   return(0);
+ }
+
 #ifndef Cdrskin_extra_leaN
  if(skin->verbosity>=Cdrskin_verbose_cmD) {
    if(skin->preskin->abort_handler==1)
@@ -7326,9 +7443,10 @@ int Cdrskin_create(struct CdrskiN **o, struct CdrpreskiN **preskin,
        (*preskin)->device_adr));
    burn_drive_add_whitelist((*preskin)->device_adr);
    if(strncmp((*preskin)->device_adr, "stdio:", 6)==0) {
-     if((*preskin)->allow_emulated_drives)
+     if((*preskin)->allow_emulated_drives) {
        stdio_drive= 1;
-     else {
+       (*preskin)->demands_cdrskin_caps= 1;
+     } else {
        fprintf(stderr,"cdrskin: SORRY : dev=stdio:... works only with option --allow_emulated_drives\n");
        {*exit_value= 2; goto ex;}
      }
@@ -7495,7 +7613,7 @@ no_drive:;
 int main(int argc, char **argv)
 {
  int ret,exit_value= 0,lib_initialized= 0,i,result_fd= -1;
- struct CdrpreskiN *preskin= NULL;
+ struct CdrpreskiN *preskin= NULL, *h_preskin= NULL;
  struct CdrskiN *skin= NULL;
  char *lean_id= "";
 #ifdef Cdrskin_extra_leaN
@@ -7571,6 +7689,25 @@ int main(int argc, char **argv)
  Cdrskin_run(skin,&exit_value,0);
 
 ex:;
+ if(preskin!=NULL)
+   h_preskin= preskin;
+ else if(skin!=NULL)
+   h_preskin= skin->preskin;
+ if(h_preskin!=NULL) {
+   if(skin->verbosity>=Cdrskin_verbose_debuG)
+     ClN(fprintf(stderr,
+       "cdrskin_debug: demands_cdrecord_caps= %d , demands_cdrskin_caps= %d\n",
+       h_preskin->demands_cdrecord_caps, h_preskin->demands_cdrskin_caps));
+
+   if(exit_value && h_preskin->demands_cdrecord_caps>0 &&
+      h_preskin->demands_cdrskin_caps<=0) {              /* prepare fallback */
+     /* detach preskin from managers which would destroy it */
+     preskin= NULL;
+     if(skin!=NULL)
+       skin->preskin= NULL;
+   } else
+     h_preskin= NULL;                                    /* prevent fallback */
+ }
  if(skin!=NULL) {
    Cleanup_set_handlers(NULL,NULL,1);
    Cdrskin_eject(skin,0);
@@ -7579,5 +7716,7 @@ ex:;
  Cdrpreskin_destroy(&preskin,0);
  if(lib_initialized)
    burn_finish();
+ if(h_preskin!=NULL)
+   Cdrpreskin_fallback(h_preskin,argc,argv); /* never come back */
  exit(exit_value);
 }

cdrskin/cdrskin_timestamp.h

@@ -1 +1 @@
-#define Cdrskin_timestamP "2007.09.19.141650"
+#define Cdrskin_timestamP "2007.09.19.212659"