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 = DIV_ROUND_UP(node->size, CLUSTER_SIZE(*ef->sb)) *
41 CLUSTER_SIZE(*ef->sb) / 512;
42 stbuf->st_mtime = node->mtime;
43 stbuf->st_atime = node->atime;
44 /* set ctime to mtime to ensure we don't break programs that rely on ctime
46 stbuf->st_ctime = node->mtime;
49 void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n)
51 if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0)
52 exfat_bug("failed to convert name to UTF-8");
55 static uint16_t add_checksum_byte(uint16_t sum, uint8_t byte)
57 return ((sum << 15) | (sum >> 1)) + byte;
60 static uint16_t add_checksum_bytes(uint16_t sum, const void* buffer, size_t n)
64 for (i = 0; i < n; i++)
65 sum = add_checksum_byte(sum, ((const uint8_t*) buffer)[i]);
69 uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
74 for (i = 0; i < sizeof(struct exfat_entry); i++)
75 if (i != 2 && i != 3) /* skip checksum field itself */
76 sum = add_checksum_byte(sum, ((const uint8_t*) entry)[i]);
80 uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
82 return add_checksum_bytes(sum, entry, sizeof(struct exfat_entry));
85 le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
86 const struct exfat_entry_meta2* meta2, const le16_t* name)
89 const int name_entries = DIV_ROUND_UP(meta2->name_length, EXFAT_ENAME_MAX);
92 checksum = exfat_start_checksum(meta1);
93 checksum = exfat_add_checksum(meta2, checksum);
94 for (i = 0; i < name_entries; i++)
96 checksum = add_checksum_byte(checksum, EXFAT_ENTRY_FILE_NAME);
97 checksum = add_checksum_byte(checksum, 0);
98 checksum = add_checksum_bytes(checksum, name + i * EXFAT_ENAME_MAX,
99 EXFAT_ENAME_MAX * sizeof(le16_t));
101 return cpu_to_le16(checksum);
104 uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
109 for (i = 0; i < size; i++)
110 /* skip volume_state and allocated_percent fields */
111 if (i != 0x6a && i != 0x6b && i != 0x70)
112 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
116 uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
120 for (i = 0; i < size; i++)
121 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
125 le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name)
128 size_t length = utf16_length(name);
131 for (i = 0; i < length; i++)
133 uint16_t c = le16_to_cpu(name[i]);
135 /* convert to upper case */
138 hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
139 hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
141 return cpu_to_le16(hash);
144 void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
147 /* 16 EB (minus 1 byte) is the largest size that can be represented by
149 const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
150 uint64_t divisor = 1;
153 for (i = 0; ; i++, divisor *= 1024)
155 temp = (value + divisor / 2) / divisor;
159 if (temp / 1024 * 1024 == temp)
168 void exfat_print_info(const struct exfat_super_block* sb,
169 uint32_t free_clusters)
171 struct exfat_human_bytes hb;
172 off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
173 off_t avail_space = (off_t) free_clusters * CLUSTER_SIZE(*sb);
175 printf("File system version %hhu.%hhu\n",
176 sb->version.major, sb->version.minor);
177 exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
178 printf("Sector size %10"PRIu64" %s\n", hb.value, hb.unit);
179 exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
180 printf("Cluster size %10"PRIu64" %s\n", hb.value, hb.unit);
181 exfat_humanize_bytes(total_space, &hb);
182 printf("Volume size %10"PRIu64" %s\n", hb.value, hb.unit);
183 exfat_humanize_bytes(total_space - avail_space, &hb);
184 printf("Used space %10"PRIu64" %s\n", hb.value, hb.unit);
185 exfat_humanize_bytes(avail_space, &hb);
186 printf("Available space %10"PRIu64" %s\n", hb.value, hb.unit);