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ffs_appleufs.c revision 1.10 
      1 /*	$NetBSD: ffs_appleufs.c,v 1.10 2010/04/24 19:58:13 dbj Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Darrin B. Jewell
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: ffs_appleufs.c,v 1.10 2010/04/24 19:58:13 dbj Exp $");
     30 
     31 #include <sys/param.h>
     32 #include <sys/time.h>
     33 #if defined(_KERNEL)
     34 #include <sys/kernel.h>
     35 #include <sys/systm.h>
     36 #endif
     37 
     38 #include <ufs/ufs/dinode.h>
     39 #include <ufs/ufs/ufs_bswap.h>
     40 #include <ufs/ffs/fs.h>
     41 #include <ufs/ffs/ffs_extern.h>
     42 
     43 #if !defined(_KERNEL) && !defined(STANDALONE)
     44 #include <stddef.h>
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <string.h>
     48 #include <errno.h>
     49 #include <assert.h>
     50 #define KASSERT(x) assert(x)
     51 #endif
     52 
     53 /*
     54  * this is the same calculation as in_cksum
     55  */
     56 u_int16_t
     57 ffs_appleufs_cksum(const struct appleufslabel *appleufs)
     58 {
     59 	const u_int16_t *p = (const u_int16_t *)appleufs;
     60 	int len = APPLEUFS_LABEL_SIZE; /* sizeof(struct appleufslabel) */
     61 	long res = 0;
     62 	while (len > 1)  {
     63 		res += *p++;
     64 		len -= 2;
     65 	}
     66 #if 0 /* APPLEUFS_LABEL_SIZE is guaranteed to be even */
     67 	if (len == 1)
     68 		res += htobe16(*(u_char *)p<<8);
     69 #endif
     70 	res = (res >> 16) + (res & 0xffff);
     71 	res += (res >> 16);
     72 	return (~res);
     73 }
     74 
     75 /* copies o to n, validating and byteswapping along the way
     76  * returns 0 if ok, EINVAL if not valid
     77  */
     78 int
     79 ffs_appleufs_validate(const char *name, const struct appleufslabel *o,
     80     struct appleufslabel *n)
     81 {
     82 	struct appleufslabel tmp;
     83 	if (!n) n = &tmp;
     84 
     85 	if (o->ul_magic != be32toh(APPLEUFS_LABEL_MAGIC)) {
     86 		return EINVAL;
     87 	}
     88 	*n = *o;
     89 	n->ul_checksum = 0;
     90 	n->ul_checksum = ffs_appleufs_cksum(n);
     91 	if (n->ul_checksum != o->ul_checksum) {
     92 #if defined(DIAGNOSTIC) || !defined(_KERNEL)
     93 		printf("%s: invalid APPLE UFS checksum. found 0x%x, expecting 0x%x",
     94 			name,o->ul_checksum,n->ul_checksum);
     95 #endif
     96 		return EINVAL;
     97 	}
     98 	n->ul_magic = be32toh(o->ul_magic);
     99 	n->ul_version = be32toh(o->ul_version);
    100 	n->ul_time = be32toh(o->ul_time);
    101 	n->ul_namelen = be16toh(o->ul_namelen);
    102 
    103 	if (n->ul_namelen > APPLEUFS_MAX_LABEL_NAME) {
    104 #if defined(DIAGNOSTIC) || !defined(_KERNEL)
    105 		printf("%s: APPLE UFS label name too long, truncated.\n",
    106 				name);
    107 #endif
    108 		n->ul_namelen = APPLEUFS_MAX_LABEL_NAME;
    109 	}
    110 	/* if len is max, will set ul_unused1 */
    111 	n->ul_name[n->ul_namelen] = '\0';
    112 
    113 #ifdef DEBUG
    114 	printf("%s: found APPLE UFS label v%d: \"%s\"\n",
    115 	    name,n->ul_version,n->ul_name);
    116 #endif
    117 	n->ul_uuid = be64toh(o->ul_uuid);
    118 
    119 	return 0;
    120 }
    121 
    122 void
    123 ffs_appleufs_set(struct appleufslabel *appleufs, const char *name, time_t t,
    124     uint64_t uuid)
    125 {
    126 	size_t namelen;
    127 	if (!name) name = "untitled";
    128 	if (t == ((time_t)-1)) {
    129 #if defined(_KERNEL)
    130 		t = time_second;
    131 #elif defined(STANDALONE)
    132 		t = 0;
    133 #else
    134 		(void)time(&t);
    135 #endif
    136 	}
    137 	if (uuid == 0) {
    138 #if defined(_KERNEL) && !defined(STANDALONE)
    139 		uuid = arc4random();
    140 		uuid <<= 32;
    141 		uuid |= arc4random();
    142 #endif
    143 	}
    144 	namelen = strlen(name);
    145 	if (namelen > APPLEUFS_MAX_LABEL_NAME)
    146 		namelen = APPLEUFS_MAX_LABEL_NAME;
    147 	memset(appleufs, 0, APPLEUFS_LABEL_SIZE);
    148 	appleufs->ul_magic   = htobe32(APPLEUFS_LABEL_MAGIC);
    149 	appleufs->ul_version = htobe32(APPLEUFS_LABEL_VERSION);
    150 	appleufs->ul_time    = htobe32((u_int32_t)t);
    151 	appleufs->ul_namelen = htobe16(namelen);
    152 	strncpy(appleufs->ul_name,name,namelen);
    153 	appleufs->ul_uuid    = htobe64(uuid);
    154 	appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
    155 }
    156