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mount_overlay.c revision 1.7 
      1 /*	$NetBSD: mount_overlay.c,v 1.7 2005/02/05 15:14:25 xtraeme Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software donated to Berkeley by
      8  * Jan-Simon Pendry.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #ifndef lint
     37 __COPYRIGHT("@(#) Copyright (c) 1992, 1993, 1994\n\
     38 	The Regents of the University of California.  All rights reserved.\n");
     39 #endif /* not lint */
     40 
     41 #ifndef lint
     42 #if 0
     43 static char sccsid[] = "@(#)mount_null.c	8.6 (Berkeley) 4/26/95";
     44 #else
     45 __RCSID("$NetBSD: mount_overlay.c,v 1.7 2005/02/05 15:14:25 xtraeme Exp $");
     46 #endif
     47 #endif /* not lint */
     48 
     49 #include <sys/param.h>
     50 #include <sys/mount.h>
     51 #include <miscfs/overlay/overlay.h>
     52 
     53 #include <err.h>
     54 #include <stdio.h>
     55 #include <unistd.h>
     56 #include <stdlib.h>
     57 #include <string.h>
     58 
     59 #include <mntopts.h>
     60 
     61 static const struct mntopt mopts[] = {
     62 	MOPT_STDOPTS,
     63 	MOPT_GETARGS,
     64 	{ NULL }
     65 };
     66 
     67 int	mount_overlay(int argc, char **argv);
     68 static void	usage(void);
     69 
     70 #ifndef MOUNT_NOMAIN
     71 int
     72 main(int argc, char **argv)
     73 {
     74 	return mount_overlay(argc, argv);
     75 }
     76 #endif
     77 
     78 int
     79 mount_overlay(int argc, char *argv[])
     80 {
     81 	struct overlay_args args;
     82 	int ch, mntflags;
     83 	char target[MAXPATHLEN], canon_dir[MAXPATHLEN];
     84 
     85 	mntflags = 0;
     86 	while ((ch = getopt(argc, argv, "o:")) != -1)
     87 		switch(ch) {
     88 		case 'o':
     89 			getmntopts(optarg, mopts, &mntflags, 0);
     90 			break;
     91 		case '?':
     92 		default:
     93 			usage();
     94 		}
     95 	argc -= optind;
     96 	argv += optind;
     97 
     98 	if (argc != 2)
     99 		usage();
    100 
    101 	if (realpath(argv[0], target) == NULL)        /* Check device path */
    102 		err(1, "realpath %s", argv[0]);
    103 	if (strncmp(argv[0], target, MAXPATHLEN)) {
    104 		warnx("\"%s\" is a relative path.", argv[0]);
    105 		warnx("using \"%s\" instead.", target);
    106 	}
    107 
    108 	if (realpath(argv[1], canon_dir) == NULL)    /* Check mounton path */
    109 		err(1, "realpath %s", argv[1]);
    110 	if (strncmp(argv[1], canon_dir, MAXPATHLEN)) {
    111 		warnx("\"%s\" is a relative path.", argv[1]);
    112 		warnx("using \"%s\" instead.", canon_dir);
    113 	}
    114 
    115 	args.la.target = target;
    116 
    117 	if (mount(MOUNT_OVERLAY, canon_dir, mntflags, &args))
    118 		err(1, "%s on %s", target, canon_dir);
    119 	exit(0);
    120 }
    121 
    122 static void
    123 usage(void)
    124 {
    125 	(void)fprintf(stderr,
    126 		"usage: mount_overlay [-o options] /overlay mount_point\n");
    127 	exit(1);
    128 }
    129