X-Git-Url: http://git.osdn.net/view?a=blobdiff_plain;f=libexfat%2Futils.c;h=e0523e029da1a51679a3cf907fc7b5bbe7437ebc;hb=386a87abe72cbacc68c0bac82384a8db4940c2a9;hp=0539403f85d8ac4e85492ad8874bb5860a7e9b47;hpb=87c8e28166f95ea1231ad94708a975a8803b0ef8;p=android-x86%2Fexternal-exfat.git diff --git a/libexfat/utils.c b/libexfat/utils.c index 0539403..e0523e0 100644 --- a/libexfat/utils.c +++ b/libexfat/utils.c @@ -1,194 +1,187 @@ /* - * utils.c - * exFAT file system implementation library. - * - * Created by Andrew Nayenko on 04.09.09. - * This software is distributed under the GNU General Public License - * version 3 or any later. - */ + utils.c (04.09.09) + exFAT file system implementation library. + + Free exFAT implementation. + Copyright (C) 2010-2016 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 #include -#include -#include -#include -#include -#include +#include +#include -static uint64_t rootdir_size(const struct exfat* ef) +void exfat_stat(const struct exfat* ef, const struct exfat_node* node, + struct stat* stbuf) { - uint64_t clusters = 0; - cluster_t rootdir_cluster = le32_to_cpu(ef->sb->rootdir_cluster); - - while (!CLUSTER_INVALID(rootdir_cluster)) - { - clusters++; - /* root directory cannot be contiguous because there is no flag - to indicate this */ - rootdir_cluster = exfat_next_cluster(ef, rootdir_cluster, 0); - } - return clusters * CLUSTER_SIZE(*ef->sb); + 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; } -int exfat_mount(struct exfat* ef, const char* spec) +void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n) { - ef->sb = malloc(sizeof(struct exfat_super_block)); - if (ef->sb == NULL) - { - exfat_error("memory allocation failed"); - return -ENOMEM; - } - - ef->fd = open(spec, O_RDONLY); /* currently read only */ - if (ef->fd < 0) - { - free(ef->sb); - exfat_error("failed to open `%s'", spec); - return -EIO; - } + if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0) + exfat_bug("failed to convert name to UTF-8"); +} - exfat_read_raw(ef->sb, sizeof(struct exfat_super_block), 0, ef->fd); - if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0) - { - close(ef->fd); - free(ef->sb); - exfat_error("exFAT file system is not found"); - return -EIO; - } +static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte) +{ + return ((sum << 15) | (sum >> 1)) + byte; +} - ef->upcase = NULL; - ef->upcase_chars = 0; - ef->rootdir_size = rootdir_size(ef); +static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n) +{ + int i; - return 0; + for (i = 0; i < n; i++) + sum = add_checksum_byte(sum, ((const uint8_t*) buffer)[i]); + return sum; } -void exfat_unmount(struct exfat* ef) +uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry) { - close(ef->fd); - ef->fd = 0; - free(ef->sb); - ef->sb = NULL; - free(ef->upcase); - ef->upcase = NULL; - ef->upcase_chars = 0; + 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 = add_checksum_byte(sum, ((const uint8_t*) entry)[i]); + return sum; } -void exfat_stat(const struct exfat_node* node, struct stat *stbuf) +uint16_t exfat_add_checksum(const void* entry, uint16_t sum) { - memset(stbuf, 0, sizeof(struct stat)); - if (node->flags & EXFAT_ATTRIB_DIR) - stbuf->st_mode = S_IFDIR | 0755; - else - stbuf->st_mode = S_IFREG | 0444; - stbuf->st_nlink = 1; - stbuf->st_size = node->size; - stbuf->st_mtime = node->mtime; - stbuf->st_atime = node->atime; - stbuf->st_ctime = 0; /* unapplicable */ + return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry)); } -#define SEC_IN_MIN 60ll -#define SEC_IN_HOUR (60 * SEC_IN_MIN) -#define SEC_IN_DAY (24 * SEC_IN_HOUR) -#define SEC_IN_YEAR (365 * SEC_IN_DAY) /* not leap year */ -/* Unix epoch started at 0:00:00 UTC 1 January 1970 */ -#define UNIX_EPOCH_YEAR 1970 -/* exFAT epoch started at 0:00:00 UTC 1 January 1980 */ -#define EXFAT_EPOCH_YEAR 1980 -/* number of years from Unix epoch to exFAT epoch */ -#define EPOCH_DIFF_YEAR (EXFAT_EPOCH_YEAR - UNIX_EPOCH_YEAR) -/* number of seconds from Unix epoch to exFAT epoch (considering leap years) */ -#define EPOCH_DIFF_SEC (EPOCH_DIFF_YEAR*365 + EPOCH_DIFF_YEAR/4) * SEC_IN_DAY - -static const time_t days_in_year[] = +le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1, + const struct exfat_entry_meta2* meta2, const le16_t* name) { - /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */ - 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 -}; + uint16_t checksum; + const int name_entries = DIV_ROUND_UP(meta2->name_length, EXFAT_ENAME_MAX); + int i; -union exfat_date -{ - uint16_t raw; - struct + checksum = exfat_start_checksum(meta1); + checksum = exfat_add_checksum(meta2, checksum); + for (i = 0; i < name_entries; i++) { - uint16_t day : 5; /* 1-31 */ - uint16_t month : 4; /* 1-12 */ - uint16_t year : 7; /* 1-127 (+1980) */ - }; -}; + checksum = add_checksum_byte(checksum, EXFAT_ENTRY_FILE_NAME); + checksum = add_checksum_byte(checksum, 0); + checksum = add_checksum_bytes(checksum, name + i * EXFAT_ENAME_MAX, + EXFAT_ENAME_MAX * sizeof(le16_t)); + } + return cpu_to_le16(checksum); +} -union exfat_time +uint32_t exfat_vbr_start_checksum(const void* sector, size_t size) { - uint16_t raw; - struct - { - uint16_t twosec : 5; /* 0-29 (2 sec granularity) */ - uint16_t min : 6; /* 0-59 */ - uint16_t hour : 5; /* 0-23 */ - }; -}; + 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; +} -static time_t get_time_shift(void) +uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum) { - struct timeval tv; - struct timezone tz; + size_t i; - if (gettimeofday(&tv, &tz) != 0) - return 0; - return tz.tz_minuteswest * SEC_IN_MIN; + for (i = 0; i < size; i++) + sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i]; + return sum; } -time_t exfat_exfat2unix(le16_t date, le16_t time) +le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name) { - union exfat_date edate; - union exfat_time etime; - time_t unix_time = EPOCH_DIFF_SEC; + size_t i; + size_t length = utf16_length(name); + uint16_t hash = 0; - edate.raw = le16_to_cpu(date); - etime.raw = le16_to_cpu(time); + for (i = 0; i < length; i++) + { + uint16_t c = le16_to_cpu(name[i]); - /* - exfat_debug("%hu-%02hu-%02hu %hu:%02hu:%02hu", - edate.year + 1980, edate.month, edate.day, - etime.hour, etime.min, etime.twosec * 2); - */ + /* convert to upper case */ + c = ef->upcase[c]; - if (edate.day == 0 || edate.month == 0 || edate.month > 12) - { - exfat_error("bad date %hu-%02hu-%02hu", - edate.year + EXFAT_EPOCH_YEAR, edate.month, edate.day); - return 0; + hash = ((hash << 15) | (hash >> 1)) + (c & 0xff); + hash = ((hash << 15) | (hash >> 1)) + (c >> 8); } - if (etime.hour > 23 || etime.min > 59 || etime.twosec > 29) + 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) { - exfat_error("bad time %hu:%02hu:%02hu", - etime.hour, etime.min, etime.twosec * 2); - return 0; + temp = (value + divisor / 2) / divisor; + + if (temp == 0) + break; + if (temp / 1024 * 1024 == temp) + continue; + if (temp < 10240) + break; } - - /* every 4th year between 1904 and 2096 is leap */ - unix_time += edate.year * SEC_IN_YEAR + edate.year / 4 * SEC_IN_DAY; - unix_time += days_in_year[edate.month] * SEC_IN_DAY; - /* if it's leap year and February has passed we should add 1 day */ - if (edate.year % 4 == 0 && edate.month > 2) - unix_time += SEC_IN_DAY; - unix_time += (edate.day - 1) * SEC_IN_DAY; - - unix_time += etime.hour * SEC_IN_HOUR; - unix_time += etime.min * SEC_IN_MIN; - /* exFAT represents time with 2 sec granularity */ - unix_time += etime.twosec * 2; - - /* exFAT stores timestamps in local time, so we correct it to UTC */ - unix_time += get_time_shift(); - - return unix_time; + hb->value = temp; + hb->unit = units[i]; } -void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n) +void exfat_print_info(const struct exfat_super_block* sb, + uint32_t free_clusters) { - if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0) - exfat_bug("failed to convert name to UTF-8"); + struct exfat_human_bytes hb; + off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb); + off_t avail_space = (off_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); }