fs/iso9660/iso9660_readdir.c

   1 /*
   2  *
   3  * (c) 2005-2009 Laurent Vivier <Laurent@vivier.eu>
   4  *
   5  * This file has been copied from EMILE, http://emile.sf.net
   6  *
   7  */
   8
   9 #include "libiso9660.h"
  10 #include "libopenbios/bindings.h"
  11 #include "libc/diskio.h"
  12
  13 #define offsetof(t,m)   ((long)&(((t *)0)->m))
  14
  15 static void read_extent(iso9660_DIR *dir)
  16 {
  17         seek_io(dir->volume->fd, dir->extent * ISOFS_BLOCK_SIZE);
  18         read_io(dir->volume->fd, dir->buffer, ISOFS_BLOCK_SIZE);
  19
  20         dir->len -= ISOFS_BLOCK_SIZE;
  21         dir->extent ++;
  22         dir->index = 0;
  23 }
  24
  25 struct iso_directory_record *iso9660_readdir(iso9660_DIR *dir)
  26 {
  27         struct iso_directory_record *idr;
  28
  29         if (dir->index >
  30             ISOFS_BLOCK_SIZE - offsetof(struct iso_directory_record, name[0]))
  31         {
  32                 if (dir->len <= 0)
  33                         return NULL;
  34
  35                 read_extent(dir);
  36         }
  37
  38         idr = (struct iso_directory_record *) &dir->buffer[dir->index];
  39         if (idr->length[0] == 0)  {
  40                 if (dir->len <= 0)
  41                         return NULL;
  42
  43                 read_extent(dir);
  44                 idr = (struct iso_directory_record *) &dir->buffer[dir->index];
  45         }
  46
  47         dir->index += dir->buffer[dir->index];
  48
  49         return idr;
  50 }