/* $OpenBSD: mount_union.c,v 1.10 2003/07/03 22:41:40 tedu Exp $ */ /* $NetBSD: mount_union.c,v 1.3 1996/04/13 01:32:11 jtc Exp $ */ /* * 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. 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 #if 0 static char sccsid[] = "@(#)mount_union.c 8.5 (Berkeley) 3/27/94"; #else static char rcsid[] = "$OpenBSD: mount_union.c,v 1.10 2003/07/03 22:41:40 tedu Exp $"; #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include "mntopts.h" const struct mntopt mopts[] = { MOPT_STDOPTS, { NULL } }; int subdir(const char *, const char *); void usage(void); int main(int argc, char *argv[]) { struct union_args args; int ch, mntflags; char target[MAXPATHLEN]; mntflags = 0; args.mntflags = UNMNT_ABOVE; while ((ch = getopt(argc, argv, "bo:r")) != -1) switch (ch) { case 'b': args.mntflags &= ~UNMNT_OPMASK; args.mntflags |= UNMNT_BELOW; break; case 'o': getmntopts(optarg, mopts, &mntflags); break; case 'r': args.mntflags &= ~UNMNT_OPMASK; args.mntflags |= UNMNT_REPLACE; break; case '?': default: usage(); /* NOTREACHED */ } argc -= optind; argv += optind; if (argc != 2) usage(); if (realpath(argv[0], target) == 0) err(1, "realpath %s", target); if (subdir(target, argv[1]) || subdir(argv[1], target)) errx(1, "%s (%s) and %s are not distinct paths", argv[0], target, argv[1]); args.target = target; if (mount(MOUNT_UNION, argv[1], mntflags, &args)) { if (errno == EOPNOTSUPP) errx(1, "%s: Filesystem not supported by kernel", argv[1]); else err(1, "%s", argv[1]); } exit(0); } int subdir(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); } void usage(void) { (void)fprintf(stderr, "usage: mount_union [-br] [-o options] target_fs mount_point\n"); exit(1); }