| /* |
| utils.c (04.09.09) |
| exFAT file system implementation library. |
| |
| Free exFAT implementation. |
| Copyright (C) 2010-2023 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->attrib & 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 = 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 |
| (e.g. rsync) */ |
| stbuf->st_ctime = node->mtime; |
| } |
| |
| void exfat_get_name(const struct exfat_node* node, |
| char buffer[EXFAT_UTF8_NAME_BUFFER_MAX]) |
| { |
| if (exfat_utf16_to_utf8(buffer, node->name, EXFAT_UTF8_NAME_BUFFER_MAX, |
| EXFAT_NAME_MAX) != 0) |
| exfat_bug("failed to convert name to UTF-8"); |
| } |
| |
| static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte) |
| { |
| return ((sum << 15) | (sum >> 1)) + byte; |
| } |
| |
| static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n) |
| { |
| size_t i; |
| |
| 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) |
| { |
| uint16_t sum = 0; |
| size_t 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; |
| } |
| |
| uint16_t exfat_add_checksum(const void* entry, uint16_t sum) |
| { |
| return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry)); |
| } |
| |
| le16_t exfat_calc_checksum(const struct exfat_entry* entries, int n) |
| { |
| uint16_t checksum; |
| int i; |
| |
| 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); |
| } |
| |
| 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 length) |
| { |
| size_t i; |
| uint16_t hash = 0; |
| |
| for (i = 0; i < length; i++) |
| { |
| uint16_t c = le16_to_cpu(name[i]); |
| |
| /* convert to upper case */ |
| c = 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; |
| 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); |
| } |
| |
| bool exfat_match_option(const char* options, const char* option_name) |
| { |
| const char* p; |
| size_t length = strlen(option_name); |
| |
| for (p = strstr(options, option_name); p; p = strstr(p + 1, option_name)) |
| if ((p == options || p[-1] == ',') && |
| (p[length] == ',' || p[length] == '\0')) |
| return true; |
| return false; |
| } |