LinuxGUI/Ventoy2Disk/Lib/exfat/src/libexfat/utils.c

   1 /*
   2         utils.c (04.09.09)
   3         exFAT file system implementation library.
   4
   5         Free exFAT implementation.
   6         Copyright (C) 2010-2018  Andrew Nayenko
   7
   8         This program is free software; you can redistribute it and/or modify
   9         it under the terms of the GNU General Public License as published by
  10         the Free Software Foundation, either version 2 of the License, or
  11         (at your option) any later version.
  12
  13         This program is distributed in the hope that it will be useful,
  14         but WITHOUT ANY WARRANTY; without even the implied warranty of
  15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16         GNU General Public License for more details.
  17
  18         You should have received a copy of the GNU General Public License along
  19         with this program; if not, write to the Free Software Foundation, Inc.,
  20         51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 */
  22
  23 #include "exfat.h"
  24 #include <string.h>
  25 #include <stdio.h>
  26 #include <inttypes.h>
  27
  28 void exfat_stat(const struct exfat* ef, const struct exfat_node* node,
  29                 struct stat* stbuf)
  30 {
  31         memset(stbuf, 0, sizeof(struct stat));
  32         if (node->attrib & EXFAT_ATTRIB_DIR)
  33                 stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask);
  34         else
  35                 stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask);
  36         stbuf->st_nlink = 1;
  37         stbuf->st_uid = ef->uid;
  38         stbuf->st_gid = ef->gid;
  39         stbuf->st_size = node->size;
  40         stbuf->st_blocks = ROUND_UP(node->size, CLUSTER_SIZE(*ef->sb)) / 512;
  41         stbuf->st_mtime = node->mtime;
  42         stbuf->st_atime = node->atime;
  43         /* set ctime to mtime to ensure we don't break programs that rely on ctime
  44            (e.g. rsync) */
  45         stbuf->st_ctime = node->mtime;
  46 }
  47
  48 void exfat_get_name(const struct exfat_node* node,
  49                 char buffer[EXFAT_UTF8_NAME_BUFFER_MAX])
  50 {
  51         if (utf16_to_utf8(buffer, node->name, EXFAT_UTF8_NAME_BUFFER_MAX,
  52                                 EXFAT_NAME_MAX) != 0)
  53                 exfat_bug("failed to convert name to UTF-8");
  54 }
  55
  56 static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte)
  57 {
  58         return ((sum << 15) | (sum >> 1)) + byte;
  59 }
  60
  61 static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n)
  62 {
  63         int i;
  64
  65         for (i = 0; i < n; i++)
  66                 sum = add_checksum_byte(sum, ((const uint8_t*) buffer)[i]);
  67         return sum;
  68 }
  69
  70 uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
  71 {
  72         uint16_t sum = 0;
  73         int i;
  74
  75         for (i = 0; i < sizeof(struct exfat_entry); i++)
  76                 if (i != 2 && i != 3) /* skip checksum field itself */
  77                         sum = add_checksum_byte(sum, ((const uint8_t*) entry)[i]);
  78         return sum;
  79 }
  80
  81 uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
  82 {
  83         return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry));
  84 }
  85
  86 le16_t exfat_calc_checksum(const struct exfat_entry* entries, int n)
  87 {
  88         uint16_t checksum;
  89         int i;
  90
  91         checksum = exfat_start_checksum((const struct exfat_entry_meta1*) entries);
  92         for (i = 1; i < n; i++)
  93                 checksum = exfat_add_checksum(entries + i, checksum);
  94         return cpu_to_le16(checksum);
  95 }
  96
  97 uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
  98 {
  99         size_t i;
 100         uint32_t sum = 0;
 101
 102         for (i = 0; i < size; i++)
 103                 /* skip volume_state and allocated_percent fields */
 104                 if (i != 0x6a && i != 0x6b && i != 0x70)
 105                         sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
 106         return sum;
 107 }
 108
 109 uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
 110 {
 111         size_t i;
 112
 113         for (i = 0; i < size; i++)
 114                 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
 115         return sum;
 116 }
 117
 118 le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name,
 119                 size_t length)
 120 {
 121         size_t i;
 122         uint16_t hash = 0;
 123
 124         for (i = 0; i < length; i++)
 125         {
 126                 uint16_t c = le16_to_cpu(name[i]);
 127
 128                 /* convert to upper case */
 129                 c = ef->upcase[c];
 130
 131                 hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
 132                 hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
 133         }
 134         return cpu_to_le16(hash);
 135 }
 136
 137 void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
 138 {
 139         size_t i;
 140         /* 16 EB (minus 1 byte) is the largest size that can be represented by
 141            uint64_t */
 142         const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
 143         uint64_t divisor = 1;
 144         uint64_t temp = 0;
 145
 146         for (i = 0; ; i++, divisor *= 1024)
 147         {
 148                 temp = (value + divisor / 2) / divisor;
 149
 150                 if (temp == 0)
 151                         break;
 152                 if (temp / 1024 * 1024 == temp)
 153                         continue;
 154                 if (temp < 10240)
 155                         break;
 156         }
 157         hb->value = temp;
 158         hb->unit = units[i];
 159 }
 160
 161 void exfat_print_info(const struct exfat_super_block* sb,
 162                 uint32_t free_clusters)
 163 {
 164         struct exfat_human_bytes hb;
 165         off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
 166         off_t avail_space = (off_t) free_clusters * CLUSTER_SIZE(*sb);
 167
 168         printf("File system version           %hhu.%hhu\n",
 169                         sb->version.major, sb->version.minor);
 170         exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
 171         printf("Sector size          %10"PRIu64" %s\n", hb.value, hb.unit);
 172         exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
 173         printf("Cluster size         %10"PRIu64" %s\n", hb.value, hb.unit);
 174         exfat_humanize_bytes(total_space, &hb);
 175         printf("Volume size          %10"PRIu64" %s\n", hb.value, hb.unit);
 176         exfat_humanize_bytes(total_space - avail_space, &hb);
 177         printf("Used space           %10"PRIu64" %s\n", hb.value, hb.unit);
 178         exfat_humanize_bytes(avail_space, &hb);
 179         printf("Available space      %10"PRIu64" %s\n", hb.value, hb.unit);
 180 }