/*
utils.c (04.09.09)
exFAT file system implementation library.
Free exFAT implementation.
Copyright (C) 2010-2013 Andrew Nayenko
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "exfat.h"
#include <string.h>
#include <stdio.h>
#include <inttypes.h>
void exfat_stat(const struct exfat* ef, const struct exfat_node* node,
struct stat* stbuf)
{
memset(stbuf, 0, sizeof(struct stat));
if (node->flags & EXFAT_ATTRIB_DIR)
stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask);
else
stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask);
stbuf->st_nlink = 1;
stbuf->st_uid = ef->uid;
stbuf->st_gid = ef->gid;
stbuf->st_size = node->size;
stbuf->st_blocks = DIV_ROUND_UP(node->size, CLUSTER_SIZE(*ef->sb)) *
CLUSTER_SIZE(*ef->sb) / 512;
stbuf->st_mtime = node->mtime;
stbuf->st_atime = node->atime;
/* set ctime to mtime to ensure we don't break programs that rely on ctime
(e.g. rsync) */
stbuf->st_ctime = node->mtime;
}
void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n)
{
if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0)
exfat_bug("failed to convert name to UTF-8");
}
uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
{
uint16_t sum = 0;
int i;
for (i = 0; i < sizeof(struct exfat_entry); i++)
if (i != 2 && i != 3) /* skip checksum field itself */
sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
return sum;
}
uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
{
int i;
for (i = 0; i < sizeof(struct exfat_entry); i++)
sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
return sum;
}
le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
const struct exfat_entry_meta2* meta2, const le16_t* name)
{
uint16_t checksum;
const int name_entries = DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX);
int i;
checksum = exfat_start_checksum(meta1);
checksum = exfat_add_checksum(meta2, checksum);
for (i = 0; i < name_entries; i++)
{
struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
MIN(EXFAT_ENAME_MAX, EXFAT_NAME_MAX - i * EXFAT_ENAME_MAX) *
sizeof(le16_t));
checksum = exfat_add_checksum(&name_entry, checksum);
}
return cpu_to_le16(checksum);
}
uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
{
size_t i;
uint32_t sum = 0;
for (i = 0; i < size; i++)
/* skip volume_state and allocated_percent fields */
if (i != 0x6a && i != 0x6b && i != 0x70)
sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
return sum;
}
uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
{
size_t i;
for (i = 0; i < size; i++)
sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
return sum;
}
le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name)
{
size_t i;
size_t length = utf16_length(name);
uint16_t hash = 0;
for (i = 0; i < length; i++)
{
uint16_t c = le16_to_cpu(name[i]);
/* convert to upper case */
if (c < ef->upcase_chars)
c = le16_to_cpu(ef->upcase[c]);
hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
}
return cpu_to_le16(hash);
}
void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
{
size_t i;
/* 16 EB (minus 1 byte) is the largest size that can be represented by
uint64_t */
const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
uint64_t divisor = 1;
uint64_t temp = 0;
for (i = 0; ; i++, divisor *= 1024)
{
temp = (value + divisor / 2) / divisor;
if (temp == 0)
break;
if (temp / 1024 * 1024 == temp)
continue;
if (temp < 10240)
break;
}
hb->value = temp;
hb->unit = units[i];
}
void exfat_print_info(const struct exfat_super_block* sb,
uint32_t free_clusters)
{
struct exfat_human_bytes hb;
off64_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
off64_t avail_space = (off64_t) free_clusters * CLUSTER_SIZE(*sb);
printf("File system version %hhu.%hhu\n",
sb->version.major, sb->version.minor);
exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
printf("Sector size %10"PRIu64" %s\n", hb.value, hb.unit);
exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
printf("Cluster size %10"PRIu64" %s\n", hb.value, hb.unit);
exfat_humanize_bytes(total_space, &hb);
printf("Volume size %10"PRIu64" %s\n", hb.value, hb.unit);
exfat_humanize_bytes(total_space - avail_space, &hb);
printf("Used space %10"PRIu64" %s\n", hb.value, hb.unit);
exfat_humanize_bytes(avail_space, &hb);
printf("Available space %10"PRIu64" %s\n", hb.value, hb.unit);
}
