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 static const 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 #if 0 45 static char sccsid[] = "@(#)mount_union.c 8.5 (Berkeley) 3/27/94"; 46 #else 47 static const char rcsid[] = 48 "$FreeBSD$"; 49 #endif 50 #endif /* not lint */ 51 52 #include <sys/param.h> 53 #include <sys/mount.h> 54 55 #include <miscfs/union/union.h> 56 57 #include <err.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <sysexits.h> 62 #include <unistd.h> 63 64 #include "mntopts.h" 65 66 static struct mntopt mopts[] = { 67 MOPT_STDOPTS, 68 { NULL } 69 }; 70 71 static int subdir __P((const char *, const char *)); 72 static void usage __P((void)) __dead2; 73 74 int 75 main(argc, argv) 76 int argc; 77 char *argv[]; 78 { 79 struct union_args args; 80 int ch, mntflags; 81 char source[MAXPATHLEN]; 82 char target[MAXPATHLEN]; 83 struct vfsconf vfc; 84 int error; 85 86 mntflags = 0; 87 args.mntflags = UNMNT_ABOVE; 88 while ((ch = getopt(argc, argv, "bo:r")) != -1) 89 switch (ch) { 90 case 'b': 91 args.mntflags &= ~UNMNT_OPMASK; 92 args.mntflags |= UNMNT_BELOW; 93 break; 94 case 'o': 95 getmntopts(optarg, mopts, &mntflags, 0); 96 break; 97 case 'r': 98 args.mntflags &= ~UNMNT_OPMASK; 99 args.mntflags |= UNMNT_REPLACE; 100 break; 101 case '?': 102 default: 103 usage(); 104 /* NOTREACHED */ 105 } 106 argc -= optind; 107 argv += optind; 108 109 if (argc != 2) 110 usage(); 111 112 /* resolve both target and source with realpath(3) */ 113 (void)checkpath(argv[0], target); 114 (void)checkpath(argv[1], source); 115 116 if (subdir(target, source) || subdir(source, target)) 117 errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths", 118 argv[0], target, argv[1], source); 119 120 args.target = target; 121 122 error = getvfsbyname("union", &vfc); 123 if (error && vfsisloadable("union")) { 124 if (vfsload("union")) 125 err(EX_OSERR, "vfsload(union)"); 126 endvfsent(); /* flush cache */ 127 error = getvfsbyname("union", &vfc); 128 } 129 if (error) 130 errx(EX_OSERR, "union filesystem is not available"); 131 132 if (mount(vfc.vfc_name, source, mntflags, &args)) 133 err(EX_OSERR, "%s", target); 134 exit(0); 135 } 136 137 int 138 subdir(p, dir) 139 const char *p; 140 const char *dir; 141 { 142 int l; 143 144 l = strlen(dir); 145 if (l <= 1) 146 return (1); 147 148 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 149 return (1); 150 151 return (0); 152 } 153 154 void 155 usage() 156 { 157 (void)fprintf(stderr, 158 "usage: mount_union [-br] [-o options] target_fs mount_point\n"); 159 exit(EX_USAGE); 160 } 161