mount_wrapfs.c

Solaris操作系统下的过滤驱动程序, C源码程序.

/*
 * Copyright (c) 1997-2003 Erez Zadok
 * Copyright (c) 2001-2003 Stony Brook University
 * Copyright (c) 1997-2000 Columbia University
 *
 * For specific licensing information, see the COPYING file distributed with
 * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
 *
 * This Copyright notice must be kept intact and distributed with all
 * fistgen sources INCLUDING sources generated by fistgen.
 */
/*
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1992, 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
/*
 * static char sccsid[] = "@(#)mount_wrapfs.c     8.6 (Berkeley) 4/26/95";
 */
static const char rcsid[] =
"$Id: mount_wrapfs.c,v 1.5 2002/12/27 20:18:58 ezk Exp $";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>

#ifdef FISTGEN
# include "fist_wrapfs.h"
#endif /* FISTGEN */
#include <fist.h>
#include <wrapfs.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#include "mntopts.h"

struct mntopt mopts[] =
{
  MOPT_STDOPTS,
  {NULL}
};

int subdir __P((const char *, const char *));
static void usage
__P((void)) __dead2;

int
main(argc, argv)
     int argc;
     char *argv[];
{
  struct wrapfs_args wrapfs_args;
  int ch, mntflags;
  char source[MAXPATHLEN];
  char target[MAXPATHLEN];
  struct vfsconf vfc;
  int error;
  char *fist_mnttype = NULL;

  mntflags = 0;
  while ((ch = getopt(argc, argv, "o:t:")) != -1)
    switch (ch) {
    case 'o':
      getmntopts(optarg, mopts, &mntflags, 0);
      break;
    case 't':
      fist_mnttype = optarg;
      break;
    case '?':
    default:
      usage();
    }
  argc -= optind;
  argv += optind;

  if (argc != 2 || !fist_mnttype)
    usage();

  if (realpath(argv[0], target) == 0)
    err(EX_OSERR, "%s", target);

  if (realpath(argv[1], source) == 0)
    err(EX_OSERR, "%s", source);

  if (subdir(target, source) || subdir(source, target))
    errx(EX_USAGE, "%s (%s) and %s are not distinct paths",
	 argv[0], target, argv[1]);

  if (strcmp(fist_mnttype, "wrapfs") == 0) {
    wrapfs_args.target = target;
    error = getvfsbyname("wrapfs", &vfc);
    if (error && vfsisloadable("wrapfs")) {
      if (vfsload("wrapfs"))
	err(EX_OSERR, "vfsload(wrapfs)");
      endvfsent();
      error = getvfsbyname("wrapfs", &vfc);
    }
    if (error)
      errx(EX_OSERR, "wrapfs/loopback filesystem is not available");

    if (mount (vfc.vfc_name, source, mntflags, &wrapfs_args))
      err(1, NULL);
  }

  exit(0);
}

int
subdir(p, dir)
     const char *p;
     const char *dir;
{
  int l;

  l = strlen(dir);
  if (l <= 1)
    return (1);

  if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0'))
    return (1);

  return (0);
}

static void
usage()
{
  (void) fprintf(stderr,
		 "usage: mount_wrapfs -t fstype [-o options] target_fs mount_point\n");
  exit(1);
}