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 static char sccsid[] = "@(#)mount_null.c 8.5 (Berkeley) 3/27/94"; 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/mount.h> 49 #include <miscfs/nullfs/null.h> 50 51 #include <err.h> 52 #include <stdio.h> 53 #include <unistd.h> 54 #include <stdlib.h> 55 #include <string.h> 56 57 #include "mntopts.h" 58 59 struct mntopt mopts[] = { 60 MOPT_STDOPTS, 61 { NULL } 62 }; 63 64 int subdir __P((const char *, const char *)); 65 void usage __P((void)); 66 67 int 68 main(argc, argv) 69 int argc; 70 char *argv[]; 71 { 72 struct null_args args; 73 int ch, mntflags; 74 char target[MAXPATHLEN]; 75 76 mntflags = 0; 77 while ((ch = getopt(argc, argv, "o:")) != EOF) 78 switch(ch) { 79 case 'o': 80 getmntopts(optarg, mopts, &mntflags); 81 break; 82 case '?': 83 default: 84 usage(); 85 } 86 argc -= optind; 87 argv += optind; 88 89 if (argc != 2) 90 usage(); 91 92 if (realpath(argv[0], target) == 0) 93 err(1, "%s", target); 94 95 if (subdir(target, argv[1]) || subdir(argv[1], target)) 96 errx(1, "%s (%s) and %s are not distinct paths", 97 argv[0], target, argv[1]); 98 99 args.target = target; 100 101 if (mount(MOUNT_NULL, argv[1], mntflags, &args)) 102 err(1, NULL); 103 exit(0); 104 } 105 106 int 107 subdir(p, dir) 108 const char *p; 109 const char *dir; 110 { 111 int l; 112 113 l = strlen(dir); 114 if (l <= 1) 115 return (1); 116 117 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 118 return (1); 119 120 return (0); 121 } 122 123 void 124 usage() 125 { 126 (void)fprintf(stderr, 127 "usage: mount_null [-o options] target_fs mount_point\n"); 128 exit(1); 129 } 130