bsd/ufs/ufs/ufs_attrlist.c

   1 /*
   2  * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 /*
  32  * ufs_attrlist.c - UFS attribute list processing
  33  *
  34  * Copyright (c) 2002, Apple Computer, Inc.  All Rights Reserved.
  35  */
  36
  37 #include <sys/types.h>
  38 #include <sys/systm.h>
  39 #include <sys/vnode_internal.h>
  40 #include <sys/malloc.h>
  41 #include <sys/attr.h>
  42 #include <sys/kernel.h>
  43 #include <sys/kauth.h>
  44
  45 #include <ufs/ufs/dinode.h>
  46 #include <ufs/ffs/fs.h>
  47 #include <sys/mount_internal.h>
  48 #include "ufsmount.h"
  49
  50 static char ufs_label_magic[4] = UFS_LABEL_MAGIC;
  51
  52 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  53 typedef union {
  54         char    c[2];
  55         u_short s;
  56 } short_union_t;
  57
  58 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  59 typedef union {
  60         u_short s[2];
  61         long    l;
  62 } long_union_t;
  63
  64 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  65 static __inline__ void
  66 reduce(int *sum)
  67 {
  68         long_union_t l_util;
  69
  70         l_util.l = *sum;
  71         *sum = l_util.s[0] + l_util.s[1];
  72         if (*sum > 65535)
  73                 *sum -= 65535;
  74         return;
  75 }
  76
  77 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  78 __private_extern__ unsigned short
  79 ul_cksum(void *data, int len)
  80 {
  81         u_short *w;
  82         int      sum;
  83
  84         sum = 0;
  85         w = (u_short *)data;
  86         while ((len -= 32) >= 0) {
  87                 sum += w[0]; sum += w[1];
  88                 sum += w[2]; sum += w[3];
  89                 sum += w[4]; sum += w[5];
  90                 sum += w[6]; sum += w[7];
  91                 sum += w[8]; sum += w[9];
  92                 sum += w[10]; sum += w[11];
  93                 sum += w[12]; sum += w[13];
  94                 sum += w[14]; sum += w[15];
  95                 w += 16;
  96         }
  97         len += 32;
  98         while ((len -= 8) >= 0) {
  99                 sum += w[0]; sum += w[1];
 100                 sum += w[2]; sum += w[3];
 101                 w += 4;
 102         }
 103         len += 8;
 104         if (len) {
 105                 reduce(&sum);
 106                 while ((len -= 2) >= 0) {
 107                         sum += *w++;
 108                 }
 109         }
 110         if (len == -1) { /* odd-length data */
 111                 short_union_t s_util;
 112
 113                 s_util.s = 0;
 114                 s_util.c[0] = *((char *)w);
 115                 s_util.c[1] = 0;
 116                 sum += s_util.s;
 117         }
 118         reduce(&sum);
 119         return (~sum & 0xffff);
 120 }
 121
 122 /* Adapted from diskdev_cmds/disklib/ufslabel.c */
 123 __private_extern__ boolean_t
 124 ufs_label_check(struct ufslabel *ul_p)
 125 {
 126         u_int16_t       calc;
 127         u_int16_t       checksum;
 128
 129         if (bcmp(&ul_p->ul_magic, ufs_label_magic,
 130             sizeof(ul_p->ul_magic))) {
 131 #ifdef DEBUG
 132                 printf("ufslabel_check: label has bad magic number\n");
 133 #endif
 134                 return (FALSE);
 135         }
 136         if (ntohl(ul_p->ul_version) != UFS_LABEL_VERSION) {
 137 #ifdef DEBUG
 138                 printf("ufslabel_check: label has incorect version %d "
 139                     "(should be %d)\n", ntohl(ul_p->ul_version),
 140                     UFS_LABEL_VERSION);
 141 #endif
 142                 return (FALSE);
 143         }
 144         if (ntohs(ul_p->ul_namelen) > UFS_MAX_LABEL_NAME) {
 145 #ifdef DEBUG
 146                 printf("ufslabel_check: name length %d is too big (> %d)\n",
 147                     ntohs(ul_p->ul_namelen), UFS_MAX_LABEL_NAME);
 148 #endif
 149                 return (FALSE);
 150         }
 151
 152         checksum = ul_p->ul_checksum;   /* Remember previous checksum. */
 153         ul_p->ul_checksum = 0;
 154         calc = ul_cksum(ul_p, sizeof(*ul_p));
 155         if (calc != checksum) {
 156 #ifdef DEBUG
 157                 printf("ufslabel_check: label checksum %x (should be %x)\n",
 158                     checksum, calc);
 159 #endif
 160                 return (FALSE);
 161         }
 162         return (TRUE);
 163 }
 164
 165 __private_extern__ void
 166 ufs_label_init(struct ufslabel *ul_p)
 167 {
 168         struct timeval tv;
 169
 170         microtime(&tv);
 171
 172         bzero(ul_p, sizeof(*ul_p));
 173         ul_p->ul_version = htonl(UFS_LABEL_VERSION);
 174         bcopy(ufs_label_magic, &ul_p->ul_magic, sizeof(ul_p->ul_magic));
 175         ul_p->ul_time = htonl(tv.tv_sec);
 176 }
 177