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 38 char 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 /* 45 static char sccsid[] = "@(#)mount_null.c 8.6 (Berkeley) 4/26/95"; 46 */ 47 static const char rcsid[] = 48 "$Id: mount_null.c,v 1.8 1997/03/11 12:33:36 peter Exp $"; 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 64 struct mntopt mopts[] = { 65 MOPT_STDOPTS, 66 { NULL } 67 }; 68 69 int subdir __P((const char *, const char *)); 70 static void usage __P((void)) __dead2; 71 72 int 73 main(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 int error; 82 83 mntflags = 0; 84 while ((ch = getopt(argc, argv, "o:")) != -1) 85 switch(ch) { 86 case 'o': 87 getmntopts(optarg, mopts, &mntflags, 0); 88 break; 89 case '?': 90 default: 91 usage(); 92 } 93 argc -= optind; 94 argv += optind; 95 96 if (argc != 2) 97 usage(); 98 99 if (realpath(argv[0], target) == 0) 100 err(EX_OSERR, "%s", target); 101 102 if (subdir(target, argv[1]) || subdir(argv[1], target)) 103 errx(EX_USAGE, "%s (%s) and %s are not distinct paths", 104 argv[0], target, argv[1]); 105 106 args.target = target; 107 108 error = getvfsbyname("null", &vfc); 109 if (error && vfsisloadable("null")) { 110 if(vfsload("null")) 111 err(EX_OSERR, "vfsload(null)"); 112 endvfsent(); 113 error = getvfsbyname("null", &vfc); 114 } 115 if (error) 116 errx(EX_OSERR, "null/loopback filesystem is not available"); 117 118 if (mount(vfc.vfc_name, argv[1], mntflags, &args)) 119 err(1, NULL); 120 exit(0); 121 } 122 123 int 124 subdir(p, dir) 125 const char *p; 126 const char *dir; 127 { 128 int l; 129 130 l = strlen(dir); 131 if (l <= 1) 132 return (1); 133 134 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 135 return (1); 136 137 return (0); 138 } 139 140 static void 141 usage() 142 { 143 (void)fprintf(stderr, 144 "usage: mount_null [-o options] target_fs mount_point\n"); 145 exit(1); 146 } 147