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 <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 static struct mntopt mopts[] = { 65 MOPT_STDOPTS, 66 { NULL } 67 }; 68 69 static int subdir(const char *, const char *); 70 static void usage (void) __dead2; 71 72 int 73 main(argc, argv) 74 int argc; 75 char *argv[]; 76 { 77 struct iovec iov[8]; 78 int ch, mntflags; 79 char source[MAXPATHLEN]; 80 char target[MAXPATHLEN]; 81 struct vfsconf vfc; 82 int error, iovcnt; 83 84 iovcnt = 6; 85 mntflags = 0; 86 while ((ch = getopt(argc, argv, "bo:r")) != -1) 87 switch (ch) { 88 case 'b': 89 iov[6].iov_base = "below"; 90 iov[6].iov_len = strlen(iov[6].iov_base) + 1; 91 iov[7].iov_base = NULL; 92 iov[7].iov_len = 0; 93 iovcnt = 8; 94 break; 95 case 'o': 96 getmntopts(optarg, mopts, &mntflags, 0); 97 break; 98 case 'r': 99 iov[6].iov_base = "replace"; 100 iov[6].iov_len = strlen(iov[6].iov_base) + 1; 101 iov[7].iov_base = NULL; 102 iov[7].iov_len = 0; 103 iovcnt = 8; 104 break; 105 case '?': 106 default: 107 usage(); 108 /* NOTREACHED */ 109 } 110 argc -= optind; 111 argv += optind; 112 113 if (argc != 2) 114 usage(); 115 116 /* resolve both target and source with realpath(3) */ 117 (void)checkpath(argv[0], target); 118 (void)checkpath(argv[1], source); 119 120 if (subdir(target, source) || subdir(source, target)) 121 errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths", 122 argv[0], target, argv[1], source); 123 124 error = getvfsbyname("unionfs", &vfc); 125 if (error && vfsisloadable("unionfs")) { 126 if (vfsload("unionfs")) 127 err(EX_OSERR, "vfsload(unionfs)"); 128 endvfsent(); /* flush cache */ 129 error = getvfsbyname("unionfs", &vfc); 130 } 131 if (error) 132 errx(EX_OSERR, "union filesystem is not available"); 133 134 iov[0].iov_base = "fstype"; 135 iov[0].iov_len = strlen(iov[0].iov_base) + 1; 136 iov[1].iov_base = vfc.vfc_name; 137 iov[1].iov_len = strlen(vfc.vfc_name) + 1; 138 iov[2].iov_base = "fspath"; 139 iov[2].iov_len = strlen(iov[2].iov_base) + 1; 140 iov[3].iov_base = source; 141 iov[3].iov_len = strlen(source) + 1; 142 iov[4].iov_base = "target"; 143 iov[4].iov_len = strlen(iov[4].iov_base) + 1; 144 iov[5].iov_base = target; 145 iov[5].iov_len = strlen(target) + 1; 146 if (nmount(iov, iovcnt, mntflags)) 147 err(EX_OSERR, "%s", target); 148 exit(0); 149 } 150 151 int 152 subdir(p, dir) 153 const char *p; 154 const char *dir; 155 { 156 int l; 157 158 l = strlen(dir); 159 if (l <= 1) 160 return (1); 161 162 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 163 return (1); 164 165 return (0); 166 } 167 168 void 169 usage() 170 { 171 (void)fprintf(stderr, 172 "usage: mount_unionfs [-br] [-o options] target_fs mount_point\n"); 173 exit(EX_USAGE); 174 } 175