| 1 | /* |
| 2 | * Copyright (c) 1992, 1993, 1994 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software donated to Berkeley by |
| 6 | * Jan-Simon Pendry. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. All advertising materials mentioning features or use of this software |
| 17 | * must display the following acknowledgement: |
| 18 | * This product includes software developed by the University of |
| 19 | * California, Berkeley and its contributors. |
| 20 | * 4. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * @(#) Copyright (c) 1992, 1993, 1994 The Regents of the University of California. All rights reserved. |
| 37 | * @(#)mount_null.c 8.6 (Berkeley) 4/26/95 |
| 38 | * $FreeBSD: src/sbin/mount_null/mount_null.c,v 1.13 1999/10/09 11:54:11 phk Exp $ |
| 39 | * $DragonFly: src/sbin/mount_null/mount_null.c,v 1.5 2003/11/01 17:16:00 drhodus Exp $ |
| 40 | */ |
| 41 | |
| 42 | #include <sys/param.h> |
| 43 | #include <sys/mount.h> |
| 44 | #include <vfs/nullfs/null.h> |
| 45 | |
| 46 | #include <err.h> |
| 47 | #include <stdio.h> |
| 48 | #include <stdlib.h> |
| 49 | #include <string.h> |
| 50 | #include <sysexits.h> |
| 51 | #include <unistd.h> |
| 52 | |
| 53 | #include "mntopts.h" |
| 54 | |
| 55 | struct mntopt mopts[] = { |
| 56 | MOPT_STDOPTS, |
| 57 | { NULL } |
| 58 | }; |
| 59 | |
| 60 | int subdir(const char *, const char *); |
| 61 | static void usage(void) __dead2; |
| 62 | |
| 63 | int |
| 64 | main(int argc, char **argv) |
| 65 | { |
| 66 | struct null_args args; |
| 67 | int ch, mntflags; |
| 68 | char source[MAXPATHLEN]; |
| 69 | char target[MAXPATHLEN]; |
| 70 | struct vfsconf vfc; |
| 71 | int error; |
| 72 | |
| 73 | mntflags = 0; |
| 74 | while ((ch = getopt(argc, argv, "o:")) != -1) |
| 75 | switch(ch) { |
| 76 | case 'o': |
| 77 | getmntopts(optarg, mopts, &mntflags, 0); |
| 78 | break; |
| 79 | case '?': |
| 80 | default: |
| 81 | usage(); |
| 82 | } |
| 83 | argc -= optind; |
| 84 | argv += optind; |
| 85 | |
| 86 | if (argc != 2) |
| 87 | usage(); |
| 88 | |
| 89 | /* resolve target and source with realpath(3) */ |
| 90 | (void)checkpath(argv[0], target); |
| 91 | (void)checkpath(argv[1], source); |
| 92 | |
| 93 | if (subdir(target, source) || subdir(source, target)) |
| 94 | errx(EX_USAGE, "%s (%s) and %s are not distinct paths", |
| 95 | argv[0], target, argv[1]); |
| 96 | |
| 97 | args.target = target; |
| 98 | |
| 99 | error = getvfsbyname("null", &vfc); |
| 100 | if (error && vfsisloadable("null")) { |
| 101 | if(vfsload("null")) |
| 102 | err(EX_OSERR, "vfsload(null)"); |
| 103 | endvfsent(); |
| 104 | error = getvfsbyname("null", &vfc); |
| 105 | } |
| 106 | if (error) |
| 107 | errx(EX_OSERR, "null/loopback filesystem is not available"); |
| 108 | |
| 109 | if (mount(vfc.vfc_name, source, mntflags, &args)) |
| 110 | err(1, NULL); |
| 111 | exit(0); |
| 112 | } |
| 113 | |
| 114 | int |
| 115 | subdir(const char *p, const char *dir) |
| 116 | { |
| 117 | int l; |
| 118 | |
| 119 | l = strlen(dir); |
| 120 | if (l <= 1) |
| 121 | return (1); |
| 122 | |
| 123 | if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) |
| 124 | return (1); |
| 125 | |
| 126 | return (0); |
| 127 | } |
| 128 | |
| 129 | static void |
| 130 | usage(void) |
| 131 | { |
| 132 | (void)fprintf(stderr, |
| 133 | "usage: mount_null [-o options] target_fs mount_point\n"); |
| 134 | exit(1); |
| 135 | } |