mount_nullfs.c revision 21673
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 37#ifndef lint 38char copyright[] = 39"@(#) Copyright (c) 1992, 1993, 1994\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41#endif /* not lint */ 42 43#ifndef lint 44/* 45static char sccsid[] = "@(#)mount_null.c 8.5 (Berkeley) 3/27/94"; 46*/ 47static const char rcsid[] = 48 "$FreeBSD: head/sbin/mount_nullfs/mount_nullfs.c 21673 1997-01-14 07:20:47Z jkh $"; 49#endif /* not lint */ 50 51#include <sys/param.h> 52#include <sys/mount.h> 53#include <miscfs/nullfs/null.h> 54 55#include <err.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59#include <sysexits.h> 60#include <unistd.h> 61 62#include "mntopts.h" 63 64struct mntopt mopts[] = { 65 MOPT_STDOPTS, 66 { NULL } 67}; 68 69int subdir __P((const char *, const char *)); 70static void usage __P((void)) __dead2; 71 72int 73main(argc, argv) 74 int argc; 75 char *argv[]; 76{ 77 struct null_args args; 78 int ch, mntflags; 79 char target[MAXPATHLEN]; 80 struct vfsconf *vfc; 81 82 mntflags = 0; 83 while ((ch = getopt(argc, argv, "o:")) != EOF) 84 switch(ch) { 85 case 'o': 86 getmntopts(optarg, mopts, &mntflags, 0); 87 break; 88 case '?': 89 default: 90 usage(); 91 } 92 argc -= optind; 93 argv += optind; 94 95 if (argc != 2) 96 usage(); 97 98 if (realpath(argv[0], target) == 0) 99 err(EX_OSERR, "%s", target); 100 101 if (subdir(target, argv[1]) || subdir(argv[1], target)) 102 errx(EX_USAGE, "%s (%s) and %s are not distinct paths", 103 argv[0], target, argv[1]); 104 105 args.target = target; 106 107 vfc = getvfsbyname("null"); 108 if(!vfc && vfsisloadable("null")) { 109 if(vfsload("null")) 110 err(EX_OSERR, "vfsload(null)"); 111 endvfsent(); /* flush cache */ 112 vfc = getvfsbyname("null"); 113 } 114 if (!vfc) 115 errx(EX_OSERR, "null filesystem is not available"); 116 117 if (mount(vfc->vfc_index, argv[1], mntflags, &args)) 118 err(EX_OSERR, target); 119 exit(0); 120} 121 122int 123subdir(p, dir) 124 const char *p; 125 const char *dir; 126{ 127 int l; 128 129 l = strlen(dir); 130 if (l <= 1) 131 return (1); 132 133 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 134 return (1); 135 136 return (0); 137} 138 139static void 140usage() 141{ 142 (void)fprintf(stderr, 143 "usage: mount_null [-o options] target_fs mount_point\n"); 144 exit(1); 145} 146