3 exFAT file system implementation library.
5 Free exFAT implementation.
6 Copyright (C) 2010-2016 Andrew Nayenko
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.
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.
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.
28 void exfat_stat(const struct exfat* ef, const struct exfat_node* node,
31 memset(stbuf, 0, sizeof(struct stat));
32 if (node->flags & EXFAT_ATTRIB_DIR)
33 stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask);
35 stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask);
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
45 stbuf->st_ctime = node->mtime;
48 void exfat_get_name(const struct exfat_node* node,
49 char buffer[EXFAT_UTF8_NAME_BUFFER_MAX])
51 if (utf16_to_utf8(buffer, node->name, EXFAT_UTF8_NAME_BUFFER_MAX,
53 exfat_bug("failed to convert name to UTF-8");
56 static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte)
58 return ((sum << 15) | (sum >> 1)) + byte;
61 static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n)
65 for (i = 0; i < n; i++)
66 sum = add_checksum_byte(sum, ((const uint8_t*) buffer)[i]);
70 uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
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]);
81 uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
83 return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry));
86 le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
87 const struct exfat_entry_meta2* meta2, const le16_t* name)
90 const int name_entries = DIV_ROUND_UP(meta2->name_length, EXFAT_ENAME_MAX);
93 checksum = exfat_start_checksum(meta1);
94 checksum = exfat_add_checksum(meta2, checksum);
95 for (i = 0; i < name_entries; i++)
97 checksum = add_checksum_byte(checksum, EXFAT_ENTRY_FILE_NAME);
98 checksum = add_checksum_byte(checksum, 0);
99 checksum = add_checksum_bytes(checksum, name + i * EXFAT_ENAME_MAX,
100 EXFAT_ENAME_MAX * sizeof(le16_t));
102 return cpu_to_le16(checksum);
105 uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
110 for (i = 0; i < size; i++)
111 /* skip volume_state and allocated_percent fields */
112 if (i != 0x6a && i != 0x6b && i != 0x70)
113 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
117 uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
121 for (i = 0; i < size; i++)
122 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
126 le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name,
132 for (i = 0; i < length; i++)
134 uint16_t c = le16_to_cpu(name[i]);
136 /* convert to upper case */
139 hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
140 hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
142 return cpu_to_le16(hash);
145 void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
148 /* 16 EB (minus 1 byte) is the largest size that can be represented by
150 const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
151 uint64_t divisor = 1;
154 for (i = 0; ; i++, divisor *= 1024)
156 temp = (value + divisor / 2) / divisor;
160 if (temp / 1024 * 1024 == temp)
169 void exfat_print_info(const struct exfat_super_block* sb,
170 uint32_t free_clusters)
172 struct exfat_human_bytes hb;
173 off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
174 off_t avail_space = (off_t) free_clusters * CLUSTER_SIZE(*sb);
176 printf("File system version %hhu.%hhu\n",
177 sb->version.major, sb->version.minor);
178 exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
179 printf("Sector size %10"PRIu64" %s\n", hb.value, hb.unit);
180 exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
181 printf("Cluster size %10"PRIu64" %s\n", hb.value, hb.unit);
182 exfat_humanize_bytes(total_space, &hb);
183 printf("Volume size %10"PRIu64" %s\n", hb.value, hb.unit);
184 exfat_humanize_bytes(total_space - avail_space, &hb);
185 printf("Used space %10"PRIu64" %s\n", hb.value, hb.unit);
186 exfat_humanize_bytes(avail_space, &hb);
187 printf("Available space %10"PRIu64" %s\n", hb.value, hb.unit);