/* mountlist.c -- return a list of mounted filesystems
   Copyright (C) 1991, 1992, 1997, 1998 Free Software Foundation, Inc.

   This program 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 2, or (at your option)
   any later version.

   This program 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 this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>
#include <sys/types.h>
#include "mountlist.h"

#ifdef STDC_HEADERS
# include <stdlib.h>
#else
void free ();
#endif
#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
# include <string.h>
#else
# include <strings.h>
#endif

#ifndef strstr
char *strstr ();
#endif
char *xmalloc ();
char *xrealloc ();
char *xstrdup ();
void error ();

#include <errno.h>
#ifndef errno
extern int errno;
#endif

#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#if HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif

#if defined (MOUNTED_GETFSSTAT)	/* __alpha running OSF_1 */
# include <sys/mount.h>
# include <sys/fs_types.h>
#endif /* MOUNTED_GETFSSTAT */

#ifdef MOUNTED_GETMNTENT1	/* 4.3BSD, SunOS, HP-UX, Dynix, Irix.  */
# include <mntent.h>
# if !defined(MOUNTED)
#  if defined(MNT_MNTTAB)	/* HP-UX.  */
#   define MOUNTED MNT_MNTTAB
#  endif
#  if defined(MNTTABNAME)	/* Dynix.  */
#   define MOUNTED MNTTABNAME
#  endif
# endif
#endif

#ifdef MOUNTED_GETMNTINFO	/* 4.4BSD.  */
# include <sys/mount.h>
#endif

#ifdef MOUNTED_GETMNT		/* Ultrix.  */
# include <sys/mount.h>
# include <sys/fs_types.h>
#endif

#ifdef MOUNTED_FREAD		/* SVR2.  */
# include <mnttab.h>
#endif

#ifdef MOUNTED_FREAD_FSTYP	/* SVR3.  */
# include <mnttab.h>
# include <sys/fstyp.h>
# include <sys/statfs.h>
#endif

#ifdef MOUNTED_LISTMNTENT
# include <mntent.h>
#endif

#ifdef MOUNTED_GETMNTENT2	/* SVR4.  */
# include <sys/mnttab.h>
#endif

#ifdef MOUNTED_VMOUNT		/* AIX.  */
# include <fshelp.h>
# include <sys/vfs.h>
#endif

#ifdef DOLPHIN
/* So special that it's not worth putting this in autoconf.  */
# undef MOUNTED_FREAD_FSTYP
# define MOUNTED_GETMNTTBL
#endif

#if HAVE_SYS_MNTENT_H
/* This is to get MNTOPT_IGNORE on e.g. SVR4.  */
# include <sys/mntent.h>
#endif

#if defined (MNTOPT_IGNORE) && defined (HAVE_HASMNTOPT)
# define MNT_IGNORE(M) hasmntopt ((M), MNTOPT_IGNORE)
#else
# define MNT_IGNORE(M) 0
#endif

#ifdef MOUNTED_GETMNTENT1	/* 4.3BSD, SunOS, HP-UX, Dynix, Irix.  */
/* Return the value of the hexadecimal number represented by CP.
   No prefix (like '0x') or suffix (like 'h') is expected to be
   part of CP. */
/* FIXME: this can overflow */

static int
xatoi (char *cp)
{
  int val;

  val = 0;
  while (*cp)
    {
      if (*cp >= 'a' && *cp <= 'f')
	val = val * 16 + *cp - 'a' + 10;
      else if (*cp >= 'A' && *cp <= 'F')
	val = val * 16 + *cp - 'A' + 10;
      else if (*cp >= '0' && *cp <= '9')
	val = val * 16 + *cp - '0';
      else
	break;
      cp++;
    }
  return val;
}
#endif /* MOUNTED_GETMNTENT1.  */

#if MOUNTED_GETMNTINFO

# if ! HAVE_F_FSTYPENAME_IN_STATFS
static char *
fstype_to_string (short t)
{
  switch (t)
    {
#  ifdef MOUNT_PC
    case MOUNT_PC:
      return "pc";
#  endif
#  ifdef MOUNT_MFS
    case MOUNT_MFS:
      return "mfs";
#  endif
#  ifdef MOUNT_LO
    case MOUNT_LO:
      return "lo";
#  endif
#  ifdef MOUNT_TFS
    case MOUNT_TFS:
      return "tfs";
#  endif
#  ifdef MOUNT_TMP
    case MOUNT_TMP:
      return "tmp";
#  endif
#  ifdef MOUNT_UFS
   case MOUNT_UFS:
     return "ufs" ;
#  endif
#  ifdef MOUNT_NFS
   case MOUNT_NFS:
     return "nfs" ;
#  endif
#  ifdef MOUNT_MSDOS
   case MOUNT_MSDOS:
     return "msdos" ;
#  endif
#  ifdef MOUNT_LFS
   case MOUNT_LFS:
     return "lfs" ;
#  endif
#  ifdef MOUNT_LOFS
   case MOUNT_LOFS:
     return "lofs" ;
#  endif
#  ifdef MOUNT_FDESC
   case MOUNT_FDESC:
     return "fdesc" ;
#  endif
#  ifdef MOUNT_PORTAL
   case MOUNT_PORTAL:
     return "portal" ;
#  endif
#  ifdef MOUNT_NULL
   case MOUNT_NULL:
     return "null" ;
#  endif
#  ifdef MOUNT_UMAP
   case MOUNT_UMAP:
     return "umap" ;
#  endif
#  ifdef MOUNT_KERNFS
   case MOUNT_KERNFS:
     return "kernfs" ;
#  endif
#  ifdef MOUNT_PROCFS
   case MOUNT_PROCFS:
     return "procfs" ;
#  endif
#  ifdef MOUNT_AFS
   case MOUNT_AFS:
     return "afs" ;
#  endif
#  ifdef MOUNT_CD9660
   case MOUNT_CD9660:
     return "cd9660" ;
#  endif
#  ifdef MOUNT_UNION
   case MOUNT_UNION:
     return "union" ;
#  endif
#  ifdef MOUNT_DEVFS
   case MOUNT_DEVFS:
     return "devfs" ;
#  endif
#  ifdef MOUNT_EXT2FS
   case MOUNT_EXT2FS:
     return "ext2fs" ;
#  endif
    default:
      return "?";
    }
}
# endif /* ! HAVE_F_FSTYPENAME_IN_STATFS */

/* __NetBSD__ || BSD_NET2 || __OpenBSD__ */
static char *
fsp_to_string (const struct statfs *fsp)
{
# if defined HAVE_F_FSTYPENAME_IN_STATFS
  return fsp->f_fstypename;
# else
  return fstype_to_string (fsp->f_type);
# endif
}

#endif /* MOUNTED_GETMNTINFO */

#ifdef MOUNTED_VMOUNT		/* AIX.  */
static char *
fstype_to_string (int t)
{
  struct vfs_ent *e;

  e = getvfsbytype (t);
  if (!e || !e->vfsent_name)
    return "none";
  else
    return e->vfsent_name;
}
#endif /* MOUNTED_VMOUNT */

/* Return a list of the currently mounted filesystems, or NULL on error.
   Add each entry to the tail of the list so that they stay in order.
   If NEED_FS_TYPE is nonzero, ensure that the filesystem type fields in
   the returned list are valid.  Otherwise, they might not be.  */

struct mount_entry *
read_filesystem_list (int need_fs_type)
{
  struct mount_entry *mount_list;
  struct mount_entry *me;
  struct mount_entry **mtail = &mount_list;

#ifdef MOUNTED_LISTMNTENT
  {
    struct tabmntent *mntlist, *p;
    struct mntent *mnt;
    struct mount_entry *me;

    /* the third and fourth arguments could be used to filter mounts,
       but Crays doesn't seem to have any mounts that we want to
       remove. Specifically, automount create normal NFS mounts.
       */

    if(listmntent(&mntlist, KMTAB, NULL, NULL) < 0)
      return NULL;
    for (p = mntlist; p; p = p->next) {
      mnt = p->ment;
      me = (struct mount_entry*) xmalloc(sizeof (struct mount_entry));
      me->me_devname = xstrdup(mnt->mnt_fsname);
      me->me_mountdir = xstrdup(mnt->mnt_dir);
      me->me_type = xstrdup(mnt->mnt_type);
      me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
      me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
      me->me_dev = -1;
      *mtail = me;
      mtail = &me->me_next;
    }
    freemntlist(mntlist);
  }
#endif

#ifdef MOUNTED_GETMNTENT1	/* 4.3BSD, SunOS, HP-UX, Dynix, Irix.  */
  {
    struct mntent *mnt;
    char *table = MOUNTED;
    FILE *fp;
    char *devopt;

    fp = setmntent (table, "r");
    if (fp == NULL)
      return NULL;

    while ((mnt = getmntent (fp)))
      {
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	me->me_devname = xstrdup (mnt->mnt_fsname);
	me->me_mountdir = xstrdup (mnt->mnt_dir);
	me->me_type = xstrdup (mnt->mnt_type);
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	devopt = strstr (mnt->mnt_opts, "dev=");
	if (devopt)
	  {
	    if (devopt[4] == '0' && (devopt[5] == 'x' || devopt[5] == 'X'))
	      me->me_dev = xatoi (devopt + 6);
	    else
	      me->me_dev = xatoi (devopt + 4);
	  }
	else
	  me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }

    if (endmntent (fp) == 0)
      goto free_then_fail;
  }
#endif /* MOUNTED_GETMNTENT1. */

#ifdef MOUNTED_GETMNTINFO	/* 4.4BSD.  */
  {
    struct statfs *fsp;
    int entries;

    entries = getmntinfo (&fsp, MNT_NOWAIT);
    if (entries < 0)
      return NULL;
    for (; entries-- > 0; fsp++)
      {
	char *fs_type = fsp_to_string (fsp);

	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	me->me_devname = xstrdup (fsp->f_mntfromname);
	me->me_mountdir = xstrdup (fsp->f_mntonname);
	me->me_type = fs_type;
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }
  }
#endif /* MOUNTED_GETMNTINFO */

#ifdef MOUNTED_GETMNT		/* Ultrix.  */
  {
    int offset = 0;
    int val;
    struct fs_data fsd;

    while (errno = 0,
	   0 < (val = getmnt (&offset, &fsd, sizeof (fsd), NOSTAT_MANY,
			      (char *) 0)))
      {
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	me->me_devname = xstrdup (fsd.fd_req.devname);
	me->me_mountdir = xstrdup (fsd.fd_req.path);
	me->me_type = gt_names[fsd.fd_req.fstype];
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	me->me_dev = fsd.fd_req.dev;

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }
    if (val < 0)
      goto free_then_fail;
  }
#endif /* MOUNTED_GETMNT. */

#if defined (MOUNTED_GETFSSTAT)	/* __alpha running OSF_1 */
  {
    int numsys, counter, bufsize;
    struct statfs *stats;

    numsys = getfsstat ((struct statfs *)0, 0L, MNT_WAIT);
    if (numsys < 0)
      return (NULL);

    bufsize = (1 + numsys) * sizeof (struct statfs);
    stats = (struct statfs *)xmalloc (bufsize);
    numsys = getfsstat (stats, bufsize, MNT_WAIT);

    if (numsys < 0)
      {
	free (stats);
	return (NULL);
      }

    for (counter = 0; counter < numsys; counter++)
      {
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	me->me_devname = xstrdup (stats[counter].f_mntfromname);
	me->me_mountdir = xstrdup (stats[counter].f_mntonname);
	me->me_type = mnt_names[stats[counter].f_type];
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }

    free (stats);
  }
#endif /* MOUNTED_GETFSSTAT */

#if defined (MOUNTED_FREAD) || defined (MOUNTED_FREAD_FSTYP) /* SVR[23].  */
  {
    struct mnttab mnt;
    char *table = "/etc/mnttab";
    FILE *fp;

    fp = fopen (table, "r");
    if (fp == NULL)
      return NULL;

    while (fread (&mnt, sizeof mnt, 1, fp) > 0)
      {
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
# ifdef GETFSTYP			/* SVR3.  */
	me->me_devname = xstrdup (mnt.mt_dev);
# else
	me->me_devname = xmalloc (strlen (mnt.mt_dev) + 6);
	strcpy (me->me_devname, "/dev/");
	strcpy (me->me_devname + 5, mnt.mt_dev);
# endif
	me->me_mountdir = xstrdup (mnt.mt_filsys);
	me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */
	me->me_type = "";
# ifdef GETFSTYP			/* SVR3.  */
	if (need_fs_type)
	  {
	    struct statfs fsd;
	    char typebuf[FSTYPSZ];

	    if (statfs (me->me_mountdir, &fsd, sizeof fsd, 0) != -1
		&& sysfs (GETFSTYP, fsd.f_fstyp, typebuf) != -1)
	      me->me_type = xstrdup (typebuf);
	  }
# endif
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }

    if (ferror (fp))
      {
	int saved_errno = errno;
	fclose (fp);
	errno = saved_errno;
	goto free_then_fail;
      }

    if (fclose (fp) == EOF)
      goto free_then_fail;
  }
#endif /* MOUNTED_FREAD || MOUNTED_FREAD_FSTYP.  */

#ifdef MOUNTED_GETMNTTBL	/* DolphinOS goes it's own way */
  {
    struct mntent **mnttbl=getmnttbl(),**ent;
    for (ent=mnttbl;*ent;ent++)
      {
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	me->me_devname = xstrdup ( (*ent)->mt_resource);
	me->me_mountdir = xstrdup( (*ent)->mt_directory);
	me->me_type =  xstrdup ((*ent)->mt_fstype);
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }
    endmnttbl();
  }
#endif

#ifdef MOUNTED_GETMNTENT2	/* SVR4.  */
  {
    struct mnttab mnt;
    char *table = MNTTAB;
    FILE *fp;
    int ret;
    int lockfd = -1;

# if defined F_RDLCK && defined F_SETLKW
    /* MNTTAB_LOCK is a macro name of our own invention; it's not present in
       e.g. Solaris 2.6.  If the SVR4 folks ever define a macro
       for this file name, we should use their macro name instead.
       (Why not just lock MNTTAB directly?  We don't know.)  */
#  ifndef MNTTAB_LOCK
#   define MNTTAB_LOCK "/etc/.mnttab.lock"
#  endif
    lockfd = open (MNTTAB_LOCK, O_RDONLY);
    if (0 <= lockfd)
      {
	struct flock flock;
	flock.l_type = F_RDLCK;
	flock.l_whence = SEEK_SET;
	flock.l_start = 0;
	flock.l_len = 0;
	while (fcntl (lockfd, F_SETLKW, &flock) == -1)
	  if (errno != EINTR)
	    {
	      int saved_errno = errno;
	      close (lockfd);
	      errno = saved_errno;
	      return NULL;
	    }
      }
    else if (errno != ENOENT)
      return NULL;
# endif

    errno = 0;
    fp = fopen (table, "r");
    if (fp == NULL)
      ret = errno;
    else
      {
	while ((ret = getmntent (fp, &mnt)) == 0)
	  {
	    me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	    me->me_devname = xstrdup (mnt.mnt_special);
	    me->me_mountdir = xstrdup (mnt.mnt_mountp);
	    me->me_type = xstrdup (mnt.mnt_fstype);
	    me->me_dummy = MNT_IGNORE (&mnt) != 0;
	    me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
	    me->me_dev = (dev_t) -1;	/* Magic; means not known yet. */

	    /* Add to the linked list. */
	    *mtail = me;
	    mtail = &me->me_next;
	  }

	ret = fclose (fp) == EOF ? errno : 0 < ret ? 0 : -1;
      }

    if (0 <= lockfd && close (lockfd) != 0)
      ret = errno;

    if (0 <= ret)
      {
	errno = ret;
	goto free_then_fail;
      }
  }
#endif /* MOUNTED_GETMNTENT2.  */

#ifdef MOUNTED_VMOUNT		/* AIX.  */
  {
    int bufsize;
    char *entries, *thisent;
    struct vmount *vmp;

    /* Ask how many bytes to allocate for the mounted filesystem info.  */
    mntctl (MCTL_QUERY, sizeof bufsize, (struct vmount *) &bufsize);
    entries = xmalloc (bufsize);

    /* Get the list of mounted filesystems.  */
    mntctl (MCTL_QUERY, bufsize, (struct vmount *) entries);

    for (thisent = entries; thisent < entries + bufsize;
	 thisent += vmp->vmt_length)
      {
	vmp = (struct vmount *) thisent;
	me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
	if (vmp->vmt_flags & MNT_REMOTE)
	  {
	    char *host, *path;

	    me->me_remote = 1;
	    /* Prepend the remote pathname.  */
	    host = thisent + vmp->vmt_data[VMT_HOSTNAME].vmt_off;
	    path = thisent + vmp->vmt_data[VMT_OBJECT].vmt_off;
	    me->me_devname = xmalloc (strlen (host) + strlen (path) + 2);
	    strcpy (me->me_devname, host);
	    strcat (me->me_devname, ":");
	    strcat (me->me_devname, path);
	  }
	else
	  {
	    me->me_remote = 0;
	    me->me_devname = xstrdup (thisent +
				      vmp->vmt_data[VMT_OBJECT].vmt_off);
	  }
	me->me_mountdir = xstrdup (thisent + vmp->vmt_data[VMT_STUB].vmt_off);
	me->me_type = xstrdup (fstype_to_string (vmp->vmt_gfstype));
	me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
	me->me_dev = (dev_t) -1; /* vmt_fsid might be the info we want.  */

	/* Add to the linked list. */
	*mtail = me;
	mtail = &me->me_next;
      }
    free (entries);
  }
#endif /* MOUNTED_VMOUNT. */

  *mtail = NULL;
  return mount_list;


 free_then_fail:
  {
    int saved_errno = errno;
    *mtail = NULL;

    while (mount_list)
      {
	me = mount_list->me_next;
	free (mount_list->me_devname);
	free (mount_list->me_mountdir);
	/* FIXME: me_type is not always malloced.  */
	free (mount_list);
	mount_list = me;
      }

    errno = saved_errno;
    return NULL;
  }
}
