Genesis-Plus-GX/source/ngc/gui/iso9660.c
2008-08-20 20:25:17 +00:00

222 lines
5.8 KiB
C

/****************************************************************************
* DVD ISO9660/Joliet Parsing
*
* This is not intended as a complete guide to ISO9660.
* Here I use the bare minimum!
***************************************************************************/
#include "shared.h"
#include "dvd.h"
#include "iso9660.h"
/** Minimal ISO Directory Definition **/
#define RECLEN 0 /* Record length */
#define EXTENT 6 /* Extent */
#define FILE_LENGTH 14 /* File length (BIG ENDIAN) */
#define FILE_FLAGS 25 /* File flags */
#define FILENAME_LENGTH 32 /* Filename length */
#define FILENAME 33 /* ASCIIZ filename */
/** Minimal Primary Volume Descriptor **/
#define PVDROOT 0x9c
static int IsJoliet = 0;
u64 rootdir = 0;
u64 basedir = 0;
int rootdirlength = 0;
/** Global file entry table **/
FILEENTRIES filelist[MAXFILES];
static char dvdbuffer[2048] ATTRIBUTE_ALIGN (32);
/****************************************************************************
* Primary Volume Descriptor
*
* The PVD should reside between sector 16 and 31.
* This is for single session DVD only.
****************************************************************************/
int getpvd ()
{
int sector = 16;
u32 rootdir32;
basedir = rootdirlength = 0;
IsJoliet = -1;
/** Look for Joliet PVD first **/
while (sector < 32)
{
if (dvd_read (&dvdbuffer, 2048, (u64)(sector << 11)))
{
if (memcmp (&dvdbuffer, "\2CD001\1", 8) == 0)
{
memcpy(&rootdir32, &dvdbuffer[PVDROOT + EXTENT], 4);
basedir = (u64)rootdir32;
memcpy (&rootdirlength, &dvdbuffer[PVDROOT + FILE_LENGTH], 4);
basedir <<= 11;
IsJoliet = 1;
break;
}
}
else return 0; /*** Can't read sector! ***/
sector++;
}
if (IsJoliet > 0) return 1; /*** Joliet PVD Found ? ***/
/*** Look for standard ISO9660 PVD ***/
sector = 16;
while (sector < 32)
{
if (dvd_read (&dvdbuffer, 2048, (u64)(sector << 11)))
{
if (memcmp (&dvdbuffer, "\1CD001\1", 8) == 0)
{
memcpy (&rootdir32, &dvdbuffer[PVDROOT + EXTENT], 4);
basedir = (u64)rootdir32;
memcpy (&rootdirlength, &dvdbuffer[PVDROOT + FILE_LENGTH], 4);
IsJoliet = 0;
basedir <<= 11;
break;
}
}
else return 0; /*** Can't read sector! ***/
sector++;
}
return (IsJoliet == 0);
}
/****************************************************************************
* getentry
*
* Support function to return the next file entry, if any
* Declared static to avoid accidental external entry.
****************************************************************************/
static int diroffset = 0;
static int getentry (int entrycount)
{
char fname[512]; /* Huge, but experience has determined this */
char *ptr;
char *filename;
char *filenamelength;
char *rr;
int j;
u32 offset32;
/* Basic checks */
if (entrycount >= MAXFILES) return 0;
if (diroffset >= 2048) return 0;
/** Decode this entry **/
if (dvdbuffer[diroffset]) /* Record length available */
{
/* Update offsets into sector buffer */
ptr = (char *) &dvdbuffer[0];
ptr += diroffset;
filename = ptr + FILENAME;
filenamelength = ptr + FILENAME_LENGTH;
/* Check for wrap round - illegal in ISO spec,
* but certain crap writers do it! */
if ((diroffset + dvdbuffer[diroffset]) > 2048) return 0;
if (*filenamelength)
{
memset (&fname, 0, 512);
/*** Do ISO 9660 first ***/
if (!IsJoliet) strcpy (fname, filename);
else
{
/*** The more tortuous unicode joliet entries ***/
for (j = 0; j < (*filenamelength >> 1); j++)
{
fname[j] = filename[j * 2 + 1];
}
fname[j] = 0;
if (strlen (fname) >= MAXJOLIET) fname[MAXJOLIET - 1] = 0;
if (strlen (fname) == 0) fname[0] = filename[0];
}
if (strlen (fname) == 0) strcpy (fname, ".");
else
{
if (fname[0] == 1) strcpy (fname, "..");
else
{
/*
* Move *filenamelength to t,
* Only to stop gcc warning for noobs :)
*/
int t = *filenamelength;
fname[t] = 0;
}
}
/** Rockridge Check **/
rr = strstr (fname, ";");
if (rr != NULL) *rr = 0;
strcpy (filelist[entrycount].filename, fname);
memcpy (&offset32, &dvdbuffer[diroffset + EXTENT], 4);
filelist[entrycount].offset = (u64)offset32;
memcpy (&filelist[entrycount].length, &dvdbuffer[diroffset + FILE_LENGTH], 4);
memcpy (&filelist[entrycount].flags, &dvdbuffer[diroffset + FILE_FLAGS], 1);
filelist[entrycount].offset <<= 11;
filelist[entrycount].flags = filelist[entrycount].flags & 2;
filelist[entrycount].filename_offset = 0;
/*** Prepare for next entry ***/
diroffset += dvdbuffer[diroffset];
return 1;
}
}
return 0;
}
/****************************************************************************
* parseDVDdirectory
*
* This function will parse the directory tree.
* It relies on rootdir and rootdirlength being pre-populated by a call to
* getpvd, a previous parse or a menu selection.
*
* The return value is number of files collected, or 0 on failure.
****************************************************************************/
int parseDVDdirectory ()
{
int pdlength;
u64 pdoffset;
u64 rdoffset;
int len = 0;
int filecount = 0;
pdoffset = rdoffset = rootdir;
pdlength = rootdirlength;
filecount = 0;
/** Clear any existing values ***/
memset (&filelist, 0, sizeof (FILEENTRIES) * MAXFILES);
/*** Get as many files as possible ***/
while (len < pdlength)
{
if (dvd_read (&dvdbuffer, 2048, pdoffset) == 0) return 0;
diroffset = 0;
while (getentry (filecount))
{
if (filecount < MAXFILES) filecount++;
}
len += 2048;
pdoffset = rdoffset + len;
}
return filecount;
}