sys/ufs/ffs/ffs_appleufs.c

   1 /*      $NetBSD: ffs_appleufs.c,v 1.15 2015/02/15 11:04:43 maxv 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 1.15 2015/02/15 11:04:43 maxv 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 #include <sys/cprng.h>
  37 #endif
  38
  39 #include <ufs/ufs/dinode.h>
  40 #include <ufs/ufs/ufs_bswap.h>
  41 #include <ufs/ffs/fs.h>
  42 #include <ufs/ffs/ffs_extern.h>
  43
  44 #if !defined(_KERNEL) && !defined(STANDALONE)
  45 #include <stddef.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <errno.h>
  50 #include <assert.h>
  51 #define KASSERT(x) assert(x)
  52 #endif
  53
  54 /*
  55  * This is the same calculation as in_cksum.
  56  */
  57 u_int16_t
  58 ffs_appleufs_cksum(const struct appleufslabel *appleufs)
  59 {
  60         const u_int16_t *p = (const u_int16_t *)appleufs;
  61         int len = APPLEUFS_LABEL_SIZE; /* sizeof(struct appleufslabel) */
  62         long res = 0;
  63         while (len > 1)  {
  64                 res += *p++;
  65                 len -= 2;
  66         }
  67 #if 0 /* APPLEUFS_LABEL_SIZE is guaranteed to be even */
  68         if (len == 1)
  69                 res += htobe16(*(u_char *)p<<8);
  70 #endif
  71         res = (res >> 16) + (res & 0xffff);
  72         res += (res >> 16);
  73         return (~res);
  74 }
  75
  76 /*
  77  * Copies o to n, validating and byteswapping along the way. Returns 0 if ok,
  78  * EINVAL if not valid.
  79  */
  80 int
  81 ffs_appleufs_validate(const char *name, const struct appleufslabel *o,
  82     struct appleufslabel *n)
  83 {
  84         struct appleufslabel tmp;
  85
  86         if (!n)
  87                 n = &tmp;
  88         if (o->ul_magic != be32toh(APPLEUFS_LABEL_MAGIC))
  89                 return EINVAL;
  90
  91         *n = *o;
  92         n->ul_checksum = 0;
  93         n->ul_checksum = ffs_appleufs_cksum(n);
  94         n->ul_magic = be32toh(o->ul_magic);
  95         n->ul_version = be32toh(o->ul_version);
  96         n->ul_time = be32toh(o->ul_time);
  97         n->ul_namelen = be16toh(o->ul_namelen);
  98
  99         if (n->ul_checksum != o->ul_checksum)
 100                 return EINVAL;
 101         if (n->ul_namelen == 0)
 102                 return EINVAL;
 103         if (n->ul_namelen > APPLEUFS_MAX_LABEL_NAME)
 104                 n->ul_namelen = APPLEUFS_MAX_LABEL_NAME;
 105
 106         n->ul_name[n->ul_namelen - 1] = '\0';
 107
 108 #ifdef DEBUG
 109         printf("%s: found APPLE UFS label v%d: \"%s\"\n", name,
 110             n->ul_version, n->ul_name);
 111 #endif
 112         n->ul_uuid = be64toh(o->ul_uuid);
 113
 114         return 0;
 115 }
 116
 117 void
 118 ffs_appleufs_set(struct appleufslabel *appleufs, const char *name, time_t t,
 119     uint64_t uuid)
 120 {
 121         size_t namelen;
 122
 123         if (!name)
 124                 name = "untitled";
 125         if (t == ((time_t)-1)) {
 126 #if defined(_KERNEL)
 127                 t = time_second;
 128 #elif defined(STANDALONE)
 129                 t = 0;
 130 #else
 131                 (void)time(&t);
 132 #endif
 133         }
 134         if (uuid == 0) {
 135 #if defined(_KERNEL) && !defined(STANDALONE)
 136                 uuid = cprng_fast64();
 137 #endif
 138         }
 139         namelen = strlen(name);
 140         if (namelen > APPLEUFS_MAX_LABEL_NAME)
 141                 namelen = APPLEUFS_MAX_LABEL_NAME;
 142         memset(appleufs, 0, APPLEUFS_LABEL_SIZE);
 143         appleufs->ul_magic   = htobe32(APPLEUFS_LABEL_MAGIC);
 144         appleufs->ul_version = htobe32(APPLEUFS_LABEL_VERSION);
 145         appleufs->ul_time    = htobe32((u_int32_t)t);
 146         appleufs->ul_namelen = htobe16(namelen);
 147         strncpy(appleufs->ul_name, name, namelen);
 148         appleufs->ul_uuid    = htobe64(uuid);
 149         appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
 150 }