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_union.c 8.5 (Berkeley) 3/27/94"; 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/mount.h> 49 50 #include <miscfs/union/union.h> 51 52 #include <err.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 #include "mntopts.h" 59 60 struct mntopt mopts[] = { 61 MOPT_STDOPTS, 62 { NULL } 63 }; 64 65 int subdir __P((const char *, const char *)); 66 void usage __P((void)); 67 68 int 69 main(argc, argv) 70 int argc; 71 char *argv[]; 72 { 73 struct union_args args; 74 int ch, mntflags; 75 char target[MAXPATHLEN]; 76 77 mntflags = 0; 78 args.mntflags = UNMNT_ABOVE; 79 while ((ch = getopt(argc, argv, "bo:r")) != EOF) 80 switch (ch) { 81 case 'b': 82 args.mntflags &= ~UNMNT_OPMASK; 83 args.mntflags |= UNMNT_BELOW; 84 break; 85 case 'o': 86 getmntopts(optarg, mopts, &mntflags); 87 break; 88 case 'r': 89 args.mntflags &= ~UNMNT_OPMASK; 90 args.mntflags |= UNMNT_REPLACE; 91 break; 92 case '?': 93 default: 94 usage(); 95 /* NOTREACHED */ 96 } 97 argc -= optind; 98 argv += optind; 99 100 if (argc != 2) 101 usage(); 102 103 if (realpath(argv[0], target) == 0) 104 err(1, "%s", target); 105 106 if (subdir(target, argv[1]) || subdir(argv[1], target)) 107 errx(1, "%s (%s) and %s are not distinct paths", 108 argv[0], target, argv[1]); 109 110 args.target = target; 111 112 if (mount(MOUNT_UNION, argv[1], mntflags, &args)) 113 err(1, NULL); 114 exit(0); 115 } 116 117 int 118 subdir(p, dir) 119 const char *p; 120 const char *dir; 121 { 122 int l; 123 124 l = strlen(dir); 125 if (l <= 1) 126 return (1); 127 128 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 129 return (1); 130 131 return (0); 132 } 133 134 void 135 usage() 136 { 137 (void)fprintf(stderr, 138 "usage: mount_union [-br] [-o options] target_fs mount_point\n"); 139 exit(1); 140 } 141