/* deviceiter.c - iterate over system devices */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2007,2008 Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>

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

#include <grub/util/misc.h>
#include <grub/util/deviceiter.h>

#ifdef __linux__
# if !defined(__GLIBC__) || \
        ((__GLIBC__ < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ < 1)))
/* Maybe libc doesn't have large file support.  */
#  include <linux/unistd.h>     /* _llseek */
# endif /* (GLIBC < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR < 1)) */
# include <sys/ioctl.h>		/* ioctl */
# ifndef HDIO_GETGEO
#  define HDIO_GETGEO	0x0301	/* get device geometry */
/* If HDIO_GETGEO is not defined, it is unlikely that hd_geometry is
   defined.  */
struct hd_geometry
{
  unsigned char heads;
  unsigned char sectors;
  unsigned short cylinders;
  unsigned long start;
};
# endif /* ! HDIO_GETGEO */
# ifndef FLOPPY_MAJOR
#  define FLOPPY_MAJOR	2	/* the major number for floppy */
# endif /* ! FLOPPY_MAJOR */
# ifndef MAJOR
#  define MAJOR(dev)	\
  ({ \
     unsigned long long __dev = (dev); \
     (unsigned) ((__dev >> 8) & 0xfff) \
                 | ((unsigned int) (__dev >> 32) & ~0xfff); \
  })
# endif /* ! MAJOR */
# ifndef CDROM_GET_CAPABILITY
#  define CDROM_GET_CAPABILITY	0x5331	/* get capabilities */
# endif /* ! CDROM_GET_CAPABILITY */
# ifndef BLKGETSIZE
#  define BLKGETSIZE	_IO(0x12,96)	/* return device size */
# endif /* ! BLKGETSIZE */
#endif /* __linux__ */

/* Use __FreeBSD_kernel__ instead of __FreeBSD__ for compatibility with
   kFreeBSD-based non-FreeBSD systems (e.g. GNU/kFreeBSD) */
#if defined(__FreeBSD__) && ! defined(__FreeBSD_kernel__)
# define __FreeBSD_kernel__
#endif
#ifdef __FreeBSD_kernel__
  /* Obtain version of kFreeBSD headers */
# include <osreldate.h>
# ifndef __FreeBSD_kernel_version
#  define __FreeBSD_kernel_version __FreeBSD_version
# endif

  /* Runtime detection of kernel */
# include <sys/utsname.h>
int
get_kfreebsd_version (void)
{
  struct utsname uts;
  int major;
  int minor;
  int v[2];

  uname (&uts);
  sscanf (uts.release, "%d.%d", &major, &minor);

  if (major >= 9)
    major = 9;
  if (major >= 5)
    {
      v[0] = minor/10; v[1] = minor%10;
    }
  else
    {
      v[0] = minor%10; v[1] = minor/10;
    }
  return major*100000+v[0]*10000+v[1]*1000;
}
#endif /* __FreeBSD_kernel__ */

#if defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__OpenBSD__)
# include <sys/ioctl.h>		/* ioctl */
# include <sys/disklabel.h>
# include <sys/cdio.h>		/* CDIOCCLRDEBUG */
# if defined(__FreeBSD_kernel__)
#  include <sys/param.h>
#  if __FreeBSD_kernel_version >= 500040
#   include <sys/disk.h>
#  endif
# endif /* __FreeBSD_kernel__ */
#endif /* __FreeBSD_kernel__ || __NetBSD__ || __OpenBSD__ */

#ifdef HAVE_OPENDISK
# include <util.h>
#endif /* HAVE_OPENDISK */

#ifdef __linux__
/* Check if we have devfs support.  */
static int
have_devfs (void)
{
  struct stat st;
  return stat ("/dev/.devfsd", &st) == 0;
}
#endif /* __linux__ */

/* These three functions are quite different among OSes.  */
static void
get_floppy_disk_name (char *name, int unit)
{
#if defined(__linux__)
  /* GNU/Linux */
  if (have_devfs ())
    sprintf (name, "/dev/floppy/%d", unit);
  else
    sprintf (name, "/dev/fd%d", unit);
#elif defined(__GNU__)
  /* GNU/Hurd */
  sprintf (name, "/dev/fd%d", unit);
#elif defined(__FreeBSD_kernel__)
  /* kFreeBSD */
  if (get_kfreebsd_version () >= 400000)
    sprintf (name, "/dev/fd%d", unit);
  else
    sprintf (name, "/dev/rfd%d", unit);
#elif defined(__NetBSD__)
  /* NetBSD */
  /* opendisk() doesn't work for floppies.  */
  sprintf (name, "/dev/rfd%da", unit);
#elif defined(__OpenBSD__)
  /* OpenBSD */
  sprintf (name, "/dev/rfd%dc", unit);
#elif defined(__QNXNTO__)
  /* QNX RTP */
  sprintf (name, "/dev/fd%d", unit);
#elif defined(__CYGWIN__)
  /* Cygwin */
  sprintf (name, "/dev/fd%d", unit);
#elif defined(__MINGW32__)
  (void) unit;
  *name = 0;
#else
# warning "BIOS floppy drives cannot be guessed in your operating system."
  /* Set NAME to a bogus string.  */
  *name = 0;
#endif
}

static void
get_ide_disk_name (char *name, int unit)
{
#if defined(__linux__)
  /* GNU/Linux */
  sprintf (name, "/dev/hd%c", unit + 'a');
#elif defined(__GNU__)
  /* GNU/Hurd */
  sprintf (name, "/dev/hd%d", unit);
#elif defined(__FreeBSD_kernel__)
  /* kFreeBSD */
  if (get_kfreebsd_version () >= 400000)
    sprintf (name, "/dev/ad%d", unit);
  else
    sprintf (name, "/dev/rwd%d", unit);
#elif defined(__NetBSD__) && defined(HAVE_OPENDISK)
  /* NetBSD */
  char shortname[16];
  int fd;

  sprintf (shortname, "wd%d", unit);
  fd = opendisk (shortname, O_RDONLY, name,
		 16,	/* length of NAME */
		 0	/* char device */
		 );
  close (fd);
#elif defined(__OpenBSD__)
  /* OpenBSD */
  sprintf (name, "/dev/rwd%dc", unit);
#elif defined(__QNXNTO__)
  /* QNX RTP */
  /* Actually, QNX RTP doesn't distinguish IDE from SCSI, so this could
     contain SCSI disks.  */
  sprintf (name, "/dev/hd%d", unit);
#elif defined(__CYGWIN__)
  /* Cygwin emulates all disks as /dev/sdX.  */
  (void) unit;
  *name = 0;
#elif defined(__MINGW32__)
  sprintf (name, "//./PHYSICALDRIVE%d", unit);
#else
# warning "BIOS IDE drives cannot be guessed in your operating system."
  /* Set NAME to a bogus string.  */
  *name = 0;
#endif
}

static void
get_scsi_disk_name (char *name, int unit)
{
#if defined(__linux__)
  /* GNU/Linux */
  sprintf (name, "/dev/sd%c", unit + 'a');
#elif defined(__GNU__)
  /* GNU/Hurd */
  sprintf (name, "/dev/sd%d", unit);
#elif defined(__FreeBSD_kernel__)
  /* kFreeBSD */
  if (get_kfreebsd_version () >= 400000)
    sprintf (name, "/dev/da%d", unit);
  else
    sprintf (name, "/dev/rda%d", unit);
#elif defined(__NetBSD__) && defined(HAVE_OPENDISK)
  /* NetBSD */
  char shortname[16];
  int fd;

  sprintf (shortname, "sd%d", unit);
  fd = opendisk (shortname, O_RDONLY, name,
		 16,	/* length of NAME */
		 0	/* char device */
		 );
  close (fd);
#elif defined(__OpenBSD__)
  /* OpenBSD */
  sprintf (name, "/dev/rsd%dc", unit);
#elif defined(__QNXNTO__)
  /* QNX RTP */
  /* QNX RTP doesn't distinguish SCSI from IDE, so it is better to
     disable the detection of SCSI disks here.  */
  *name = 0;
#elif defined(__CYGWIN__)
  /* Cygwin emulates all disks as /dev/sdX.  */
  sprintf (name, "/dev/sd%c", unit + 'a');
#elif defined(__MINGW32__)
  (void) unit;
  *name = 0;
#else
# warning "BIOS SCSI drives cannot be guessed in your operating system."
  /* Set NAME to a bogus string.  */
  *name = 0;
#endif
}

#ifdef __linux__
static void
get_virtio_disk_name (char *name, int unit)
{
#ifdef __sparc__
  sprintf (name, "/dev/vdisk%c", unit + 'a');
#else
  sprintf (name, "/dev/vd%c", unit + 'a');
#endif
}

static void
get_dac960_disk_name (char *name, int controller, int drive)
{
  sprintf (name, "/dev/rd/c%dd%d", controller, drive);
}

static void
get_ataraid_disk_name (char *name, int unit)
{
  sprintf (name, "/dev/ataraid/d%c", unit + '0');
}

static void
get_i2o_disk_name (char *name, char unit)
{
  sprintf (name, "/dev/i2o/hd%c", unit);
}

static void
get_cciss_disk_name (char *name, int controller, int drive)
{
  sprintf (name, "/dev/cciss/c%dd%d", controller, drive);
}

static void
get_ida_disk_name (char *name, int controller, int drive)
{
  sprintf (name, "/dev/ida/c%dd%d", controller, drive);
}

static void
get_mmc_disk_name (char *name, int unit)
{
  sprintf (name, "/dev/mmcblk%d", unit);
}

static void
get_xvd_disk_name (char *name, int unit)
{
  sprintf (name, "/dev/xvd%c", unit + 'a');
}
#endif

/* Check if DEVICE can be read. If an error occurs, return zero,
   otherwise return non-zero.  */
static int
check_device (const char *device)
{
  char buf[512];
  FILE *fp;

  /* If DEVICE is empty, just return error.  */
  if (*device == 0)
    return 0;

  fp = fopen (device, "r");
  if (! fp)
    {
      switch (errno)
	{
#ifdef ENOMEDIUM
	case ENOMEDIUM:
# if 0
	  /* At the moment, this finds only CDROMs, which can't be
	     read anyway, so leave it out. Code should be
	     reactivated if `removable disks' and CDROMs are
	     supported.  */
	  /* Accept it, it may be inserted.  */
	  return 1;
# endif
	  break;
#endif /* ENOMEDIUM */
	default:
	  /* Break case and leave.  */
	  break;
	}
      /* Error opening the device.  */
      return 0;
    }

  /* Make sure CD-ROMs don't get assigned a BIOS disk number
     before SCSI disks!  */
#ifdef __linux__
# ifdef CDROM_GET_CAPABILITY
  if (ioctl (fileno (fp), CDROM_GET_CAPABILITY, 0) >= 0)
    return 0;
# else /* ! CDROM_GET_CAPABILITY */
  /* Check if DEVICE is a CD-ROM drive by the HDIO_GETGEO ioctl.  */
  {
    struct hd_geometry hdg;
    struct stat st;

    if (fstat (fileno (fp), &st))
      return 0;

    /* If it is a block device and isn't a floppy, check if HDIO_GETGEO
       succeeds.  */
    if (S_ISBLK (st.st_mode)
	&& MAJOR (st.st_rdev) != FLOPPY_MAJOR
	&& ioctl (fileno (fp), HDIO_GETGEO, &hdg))
      return 0;
  }
# endif /* ! CDROM_GET_CAPABILITY */
#endif /* __linux__ */

#if defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__OpenBSD__)
# ifdef CDIOCCLRDEBUG
  if (ioctl (fileno (fp), CDIOCCLRDEBUG, 0) >= 0)
    return 0;
# endif /* CDIOCCLRDEBUG */
#endif /* __FreeBSD_kernel__ || __NetBSD__ || __OpenBSD__ */

  /* Attempt to read the first sector.  */
  if (fread (buf, 1, 512, fp) != 512)
    {
      fclose (fp);
      return 0;
    }

  fclose (fp);
  return 1;
}

void
grub_util_iterate_devices (int NESTED_FUNC_ATTR (*hook) (const char *, int),
			   int floppy_disks)
{
  int i;

  /* Floppies.  */
  for (i = 0; i < floppy_disks; i++)
    {
      char name[16];
      struct stat st;

      get_floppy_disk_name (name, i);
      if (stat (name, &st) < 0)
	break;
      /* In floppies, write the map, whether check_device succeeds
	 or not, because the user just may not insert floppies.  */
      if (hook (name, 1))
	return;
    }

#ifdef __linux__
  if (have_devfs ())
    {
      i = 0;
      while (1)
	{
	  char discn[32];
	  char name[PATH_MAX];
	  struct stat st;

	  /* Linux creates symlinks "/dev/discs/discN" for convenience.
	     The way to number disks is the same as GRUB's.  */
	  sprintf (discn, "/dev/discs/disc%d", i++);
	  if (stat (discn, &st) < 0)
	    break;

	  if (realpath (discn, name))
	    {
	      strcat (name, "/disc");
	      if (hook (name, 0))
		return;
	    }
	}
      return;
    }
#endif /* __linux__ */

  /* IDE disks.  */
  for (i = 0; i < 26; i++)
    {
      char name[16];

      get_ide_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
	}
    }

#ifdef __linux__
  /* Virtio disks.  */
  for (i = 0; i < 26; i++)
    {
      char name[16];

      get_virtio_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
	}
    }

  /* ATARAID disks.  */
  for (i = 0; i < 8; i++)
    {
      char name[20];

      get_ataraid_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
        }
    }

  /* Xen virtual block devices.  */
  for (i = 0; i < 26; i++)
    {
      char name[16];

      get_xvd_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
	}
    }
#endif /* __linux__ */

  /* The rest is SCSI disks.  */
  for (i = 0; i < 26; i++)
    {
      char name[16];

      get_scsi_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
	}
    }

#ifdef __linux__
  /* This is for DAC960 - we have
     /dev/rd/c<controller>d<logical drive>p<partition>.

     DAC960 driver currently supports up to 8 controllers, 32 logical
     drives, and 7 partitions.  */
  {
    int controller, drive;

    for (controller = 0; controller < 8; controller++)
      {
	for (drive = 0; drive < 15; drive++)
	  {
	    char name[24];

	    get_dac960_disk_name (name, controller, drive);
	    if (check_device (name))
	      {
		if (hook (name, 0))
		  return;
	      }
	  }
      }
  }

  /* This is for CCISS - we have
     /dev/cciss/c<controller>d<logical drive>p<partition>.  */
  {
    int controller, drive;

    for (controller = 0; controller < 3; controller++)
      {
	for (drive = 0; drive < 16; drive++)
	  {
	    char name[24];

	    get_cciss_disk_name (name, controller, drive);
	    if (check_device (name))
	      {
		if (hook (name, 0))
		  return;
	      }
	  }
      }
  }

  /* This is for Compaq Intelligent Drive Array - we have
     /dev/ida/c<controller>d<logical drive>p<partition>.  */
  {
    int controller, drive;

    for (controller = 0; controller < 3; controller++)
      {
	for (drive = 0; drive < 16; drive++)
	  {
	    char name[24];

	    get_ida_disk_name (name, controller, drive);
	    if (check_device (name))
	      {
		if (hook (name, 0))
		  return;
	      }
	  }
      }
  }

  /* This is for I2O - we have /dev/i2o/hd<logical drive><partition> */
  {
    char unit;

    for (unit = 'a'; unit < 'f'; unit++)
      {
	char name[24];

	get_i2o_disk_name (name, unit);
	if (check_device (name))
	  {
	    if (hook (name, 0))
	      return;
	  }
      }
  }

  /* MultiMediaCard (MMC).  */
  for (i = 0; i < 10; i++)
    {
      char name[16];

      get_mmc_disk_name (name, i);
      if (check_device (name))
	{
	  if (hook (name, 0))
	    return;
	}
    }
#endif /* __linux__ */
}