/* virtual-backup.c

 Copyright (c) 2000-2004 Craig Condit, Stefan Hülswitt.

 Redistribution and use in source and binary forms, with or without

 modification, are permitted provided that the following conditions are met: 

 1. Redistributions of source code must retain the above copyright notice,

    this list of conditions and the following disclaimer. 

 2. Redistributions in binary form must reproduce the above copyright notice,

    this list of conditions and the following disclaimer in the documentation

    and/or other materials provided with the distribution. 

 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS

 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR

 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 SUCH DAMAGE.

 */

 #define _LARGEFILE64_SOURCE

 #define _GNU_SOURCE

 #include <stdlib.h>

 #include <stdio.h>

 #include <unistd.h>

 #include <fcntl.h>

 #include <errno.h>

 #include <string.h>

 #include <sys/wait.h>

 #include <sys/stat.h>

 #include "virtual.h"

 #include "cdbackup.h"

 #include "cdrom.h"

 #include "misc.h"

 #include "debug.h"

 //#define DEBUGOUT

 extern int virtual, multi;

 extern int fd;

 extern struct virt_header *virt_header;

 extern int virtualMissing;

 extern char *real_virt_name;

 #ifndef DEBUGOUT

 static pid_t childpid;

 #endif

 static int vfd=-1;

 /****************************************************************************/

 void VnewTrack(void)

 {

   if(virtual) {

     long long pos;

     if(virtualMissing) {

       if((fd=open64(real_virt_name,O_RDWR|O_CREAT,S_IRUSR|S_IWUSR|S_IRGRP| S_IROTH))<0) error("Open failed (new track)");

       if(write(fd,virt_header,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed (new track)");

       virtualMissing=0;

       }

     if(virt_header->tracks>=MAX_VIRT_TRACKS-1) serror("Maximum number of virtual tracks reached");

     pos=(long long)(virt_header->start[virt_header->tracks]=virt_header->leadout)*CD_FRAMESIZE;

     virt_header->tracks++;

     if(lseek64(fd,pos,SEEK_SET)<0) error("Seek failed (new track)");

     }

   else {

 #ifndef DEBUGOUT

     int pd[2];

     Vclose();

     if(pipe(pd)<0) error("Pipe failed (new track)");

     if((childpid=fork())<0) error("Fork failed (new track)");

     if(childpid==0) { /* child */

       close(pd[1]);

       close(0);

       dup2(pd[0],0);

       start_cdrecord(); /* doesn't returns */

       }

     close(pd[0]); fd=pd[1];

 #else

     /* debug code; send data to /dev/null. */

     Vclose();

     fprintf(stderr,"DEBUG CODE: NO recording, sending data to /dev/null!\n");

     if((fd=open("/dev/null",O_WRONLY))<0) error("Open failed (/dev/null)");

 #endif

     cd_avail-=padsize*CD_FRAMESIZE;

     }

 }

 /****************************************************************************/

 int Vsize(void)

 {

   return virt_header->leadout;

 }

 /****************************************************************************/

 int VhasCont(void)

 {

   return virt_header->has_cont;

 }

 /****************************************************************************/

 void VprepareDump(void)

 {

   if((vfd=dup(fd))<0) error("Dup failed");

   Vclose();

 }

 /****************************************************************************/

 void VvirtRead(void *buf)

 {

   if(full_read(vfd,buf,CD_FRAMESIZE)!=CD_FRAMESIZE)

     serror("Unexpected EOF reading data");

 }

 /****************************************************************************/

 void VcloseTrack(int cont)

 {

   if(virtual) {

     if(lseek64(fd,0,SEEK_SET)<0) error("Seek failed (close track)");

     virt_header->has_cont=cont;

     if(write(fd,virt_header,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed (close track)");

     Vclose();

     }

   else {

     Vclose();

 #ifndef DEBUGOUT

     DEBUG("VcloseTrack: waiting for child termination\n");

     while(wait(0)!=childpid);

 #endif

     }

   if(vfd>=0) { close(vfd); vfd=-1; }

 }

 /****************************************************************************/

 void Vwrite(const void *buf)

 {

   if(write(fd,buf,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed");

   if(virtual) virt_header->leadout++;

   cd_avail-=CD_FRAMESIZE;

 }