X-Git-Url: http://git.sven.stormbind.net/?p=sven%2Fexfat-utils.git;a=blobdiff_plain;f=libexfat%2Futils.c;h=c080d4c4288d3392c58064a3d613c5047e32f2e4;hp=31b7e8cce38b9d91d1a5a9de0009734b648802ce;hb=2fa6c5654e0a345af10df5227b77d9f468759f20;hpb=dbe4348df2ba88986e13163ef13d09fb7247589d diff --git a/libexfat/utils.c b/libexfat/utils.c index 31b7e8c..c080d4c 100644 --- a/libexfat/utils.c +++ b/libexfat/utils.c @@ -2,11 +2,12 @@ utils.c (04.09.09) exFAT file system implementation library. - Copyright (C) 2009, 2010 Andrew Nayenko + Free exFAT implementation. + Copyright (C) 2010-2017 Andrew Nayenko - This program is free software: you can redistribute it and/or modify + 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 3 of the License, or + 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, @@ -14,22 +15,21 @@ 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, see . + 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 -#define _XOPEN_SOURCE /* for timezone in Linux */ -#include 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) + if (node->attrib & EXFAT_ATTRIB_DIR) stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask); else stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask); @@ -37,8 +37,7 @@ void exfat_stat(const struct exfat* ef, const struct exfat_node* node, 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_blocks = ROUND_UP(node->size, 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 @@ -46,132 +45,26 @@ void exfat_stat(const struct exfat* ef, const struct exfat_node* node, stbuf->st_ctime = node->mtime; } -#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 days from Unix epoch to exFAT epoch (considering leap days) */ -#define EPOCH_DIFF_DAYS (EPOCH_DIFF_YEAR * 365 + EPOCH_DIFF_YEAR / 4) -/* number of seconds from Unix epoch to exFAT epoch (considering leap days) */ -#define EPOCH_DIFF_SEC (EPOCH_DIFF_DAYS * SEC_IN_DAY) -/* number of leap years passed from exFAT epoch to the specified year - (excluding the specified year itself) */ -#define LEAP_YEARS(year) ((EXFAT_EPOCH_YEAR + (year) - 1) / 4 \ - - (EXFAT_EPOCH_YEAR - 1) / 4) -/* checks whether the specified year is leap */ -#define IS_LEAP_YEAR(year) ((EXFAT_EPOCH_YEAR + (year)) % 4 == 0) - -static const time_t days_in_year[] = +void exfat_get_name(const struct exfat_node* node, + char buffer[EXFAT_UTF8_NAME_BUFFER_MAX]) { - /* 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 -}; + if (utf16_to_utf8(buffer, node->name, EXFAT_UTF8_NAME_BUFFER_MAX, + EXFAT_NAME_MAX) != 0) + exfat_bug("failed to convert name to UTF-8"); +} -time_t exfat_exfat2unix(le16_t date, le16_t time, uint8_t centisec) +static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte) { - time_t unix_time = EPOCH_DIFF_SEC; - uint16_t ndate = le16_to_cpu(date); - uint16_t ntime = le16_to_cpu(time); - - uint16_t day = ndate & 0x1f; /* 5 bits, 1-31 */ - uint16_t month = ndate >> 5 & 0xf; /* 4 bits, 1-12 */ - uint16_t year = ndate >> 9; /* 7 bits, 1-127 (+1980) */ - - uint16_t twosec = ntime & 0x1f; /* 5 bits, 0-29 (2 sec granularity) */ - uint16_t min = ntime >> 5 & 0xf; /* 6 bits, 0-59 */ - uint16_t hour = ntime >> 11; /* 5 bits, 0-23 */ - - if (day == 0 || month == 0 || month > 12) - { - exfat_error("bad date %hu-%02hu-%02hu", - year + EXFAT_EPOCH_YEAR, month, day); - return 0; - } - if (hour > 23 || min > 59 || twosec > 29) - { - exfat_error("bad time %hu:%02hu:%02hu", - hour, min, twosec * 2); - return 0; - } - if (centisec > 199) - { - exfat_error("bad centiseconds count %hhu", centisec); - return 0; - } - - /* every 4th year between 1904 and 2096 is leap */ - unix_time += year * SEC_IN_YEAR + LEAP_YEARS(year) * SEC_IN_DAY; - unix_time += days_in_year[month] * SEC_IN_DAY; - /* if it's leap year and February has passed we should add 1 day */ - if ((EXFAT_EPOCH_YEAR + year) % 4 == 0 && month > 2) - unix_time += SEC_IN_DAY; - unix_time += (day - 1) * SEC_IN_DAY; - - unix_time += hour * SEC_IN_HOUR; - unix_time += min * SEC_IN_MIN; - /* exFAT represents time with 2 sec granularity */ - unix_time += twosec * 2; - unix_time += centisec / 100; - - /* exFAT stores timestamps in local time, so we correct it to UTC */ - unix_time += timezone; - - return unix_time; + return ((sum << 15) | (sum >> 1)) + byte; } -void exfat_unix2exfat(time_t unix_time, le16_t* date, le16_t* time, - uint8_t* centisec) +static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n) { - time_t shift = EPOCH_DIFF_SEC + timezone; - uint16_t day, month, year; - uint16_t twosec, min, hour; - int days; int i; - /* time before exFAT epoch cannot be represented */ - if (unix_time < shift) - unix_time = shift; - - unix_time -= shift; - - days = unix_time / SEC_IN_DAY; - year = (4 * days) / (4 * 365 + 1); - days -= year * 365 + LEAP_YEARS(year); - month = 0; - for (i = 1; i <= 12; i++) - { - int leap_day = (IS_LEAP_YEAR(year) && i == 2); - int leap_sub = (IS_LEAP_YEAR(year) && i >= 3); - - if (i == 12 || days - leap_sub < days_in_year[i + 1] + leap_day) - { - month = i; - days -= days_in_year[i] + leap_sub; - break; - } - } - day = days + 1; - - hour = (unix_time % SEC_IN_DAY) / SEC_IN_HOUR; - min = (unix_time % SEC_IN_HOUR) / SEC_IN_MIN; - twosec = (unix_time % SEC_IN_MIN) / 2; - - *date = cpu_to_le16(day | (month << 5) | (year << 9)); - *time = cpu_to_le16(twosec | (min << 5) | (hour << 11)); - if (centisec) - *centisec = (unix_time % 2) * 100; -} - -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"); + for (i = 0; i < n; i++) + sum = add_checksum_byte(sum, ((const uint8_t*) buffer)[i]); + return sum; } uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry) @@ -181,35 +74,23 @@ uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry) 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]; + sum = add_checksum_byte(sum, ((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; + return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry)); } -le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1, - const struct exfat_entry_meta2* meta2, const le16_t* name) +le16_t exfat_calc_checksum(const struct exfat_entry* entries, int n) { 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, - EXFAT_ENAME_MAX * sizeof(le16_t)); - checksum = exfat_add_checksum(&name_entry, checksum); - } + checksum = exfat_start_checksum((const struct exfat_entry_meta1*) entries); + for (i = 1; i < n; i++) + checksum = exfat_add_checksum(entries + i, checksum); return cpu_to_le16(checksum); } @@ -234,11 +115,10 @@ uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum) return sum; } - -le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name) +le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name, + size_t length) { size_t i; - size_t length = utf16_length(name); uint16_t hash = 0; for (i = 0; i < length; i++) @@ -246,8 +126,7 @@ le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name) uint16_t c = le16_to_cpu(name[i]); /* convert to upper case */ - if (c < ef->upcase_chars) - c = le16_to_cpu(ef->upcase[c]); + c = ef->upcase[c]; hash = ((hash << 15) | (hash >> 1)) + (c & 0xff); hash = ((hash << 15) | (hash >> 1)) + (c >> 8); @@ -258,11 +137,13 @@ le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name) void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb) { size_t i; - const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB"}; + /* 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 < sizeof(units) / sizeof(units[0]) - 1; i++, divisor *= 1024) + for (i = 0; ; i++, divisor *= 1024) { temp = (value + divisor / 2) / divisor;