bsd/ufs/ufs/ufs_attrlist.c

   1 /*
   2  * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 /*
  24  * ufs_attrlist.c - UFS attribute list processing
  25  *
  26  * Copyright (c) 2002, Apple Computer, Inc.  All Rights Reserved.
  27  */
  28
  29 #include <sys/types.h>
  30 #include <sys/systm.h>
  31 #include <sys/vnode_internal.h>
  32 #include <sys/malloc.h>
  33 #include <sys/attr.h>
  34 #include <sys/kernel.h>
  35 #include <sys/kauth.h>
  36
  37 #include <architecture/byte_order.h>
  38 #include <ufs/ufs/dinode.h>
  39 #include <ufs/ffs/fs.h>
  40 #include <sys/mount_internal.h>
  41 #include "ufsmount.h"
  42
  43 static char ufs_label_magic[4] = UFS_LABEL_MAGIC;
  44
  45 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  46 typedef union {
  47         char    c[2];
  48         u_short s;
  49 } short_union_t;
  50
  51 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  52 typedef union {
  53         u_short s[2];
  54         long    l;
  55 } long_union_t;
  56
  57 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  58 static __inline__ void
  59 reduce(int *sum)
  60 {
  61         long_union_t l_util;
  62
  63         l_util.l = *sum;
  64         *sum = l_util.s[0] + l_util.s[1];
  65         if (*sum > 65535)
  66                 *sum -= 65535;
  67         return;
  68 }
  69
  70 /* Copied from diskdev_cmds/disklib/ufslabel.c */
  71 __private_extern__ unsigned short
  72 ul_cksum(void *data, int len)
  73 {
  74         u_short *w;
  75         int      sum;
  76
  77         sum = 0;
  78         w = (u_short *)data;
  79         while ((len -= 32) >= 0) {
  80                 sum += w[0]; sum += w[1];
  81                 sum += w[2]; sum += w[3];
  82                 sum += w[4]; sum += w[5];
  83                 sum += w[6]; sum += w[7];
  84                 sum += w[8]; sum += w[9];
  85                 sum += w[10]; sum += w[11];
  86                 sum += w[12]; sum += w[13];
  87                 sum += w[14]; sum += w[15];
  88                 w += 16;
  89         }
  90         len += 32;
  91         while ((len -= 8) >= 0) {
  92                 sum += w[0]; sum += w[1];
  93                 sum += w[2]; sum += w[3];
  94                 w += 4;
  95         }
  96         len += 8;
  97         if (len) {
  98                 reduce(&sum);
  99                 while ((len -= 2) >= 0) {
 100                         sum += *w++;
 101                 }
 102         }
 103         if (len == -1) { /* odd-length data */
 104                 short_union_t s_util;
 105
 106                 s_util.s = 0;
 107                 s_util.c[0] = *((char *)w);
 108                 s_util.c[1] = 0;
 109                 sum += s_util.s;
 110         }
 111         reduce(&sum);
 112         return (~sum & 0xffff);
 113 }
 114
 115 /* Adapted from diskdev_cmds/disklib/ufslabel.c */
 116 __private_extern__ boolean_t
 117 ufs_label_check(struct ufslabel *ul_p)
 118 {
 119         u_int16_t       calc;
 120         u_int16_t       checksum;
 121
 122         if (bcmp(&ul_p->ul_magic, ufs_label_magic,
 123             sizeof(ul_p->ul_magic))) {
 124 #ifdef DEBUG
 125                 printf("ufslabel_check: label has bad magic number\n");
 126 #endif
 127                 return (FALSE);
 128         }
 129         if (ntohl(ul_p->ul_version) != UFS_LABEL_VERSION) {
 130 #ifdef DEBUG
 131                 printf("ufslabel_check: label has incorect version %d "
 132                     "(should be %d)\n", ntohl(ul_p->ul_version),
 133                     UFS_LABEL_VERSION);
 134 #endif
 135                 return (FALSE);
 136         }
 137         if (ntohs(ul_p->ul_namelen) > UFS_MAX_LABEL_NAME) {
 138 #ifdef DEBUG
 139                 printf("ufslabel_check: name length %d is too big (> %d)\n",
 140                     ntohs(ul_p->ul_namelen), UFS_MAX_LABEL_NAME);
 141 #endif
 142                 return (FALSE);
 143         }
 144
 145         checksum = ul_p->ul_checksum;   /* Remember previous checksum. */
 146         ul_p->ul_checksum = 0;
 147         calc = ul_cksum(ul_p, sizeof(*ul_p));
 148         if (calc != checksum) {
 149 #ifdef DEBUG
 150                 printf("ufslabel_check: label checksum %x (should be %x)\n",
 151                     checksum, calc);
 152 #endif
 153                 return (FALSE);
 154         }
 155         return (TRUE);
 156 }
 157
 158 __private_extern__ void
 159 ufs_label_init(struct ufslabel *ul_p)
 160 {
 161         struct timeval tv;
 162
 163         microtime(&tv);
 164
 165         bzero(ul_p, sizeof(*ul_p));
 166         ul_p->ul_version = htonl(UFS_LABEL_VERSION);
 167         bcopy(ufs_label_magic, &ul_p->ul_magic, sizeof(ul_p->ul_magic));
 168         ul_p->ul_time = htonl(tv.tv_sec);
 169 }
 170