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bigbiff bigbiff9c754052013-01-09 09:09:08 -05001/*
2 utils.c (04.09.09)
3 exFAT file system implementation library.
4
5 Copyright (C) 2010-2012 Andrew Nayenko
6
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "exfat.h"
22#include <string.h>
23#include <stdio.h>
24#include <inttypes.h>
25
26void exfat_stat(const struct exfat* ef, const struct exfat_node* node,
27 struct stat* stbuf)
28{
29 memset(stbuf, 0, sizeof(struct stat));
30 if (node->flags & EXFAT_ATTRIB_DIR)
31 stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask);
32 else
33 stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask);
34 stbuf->st_nlink = 1;
35 stbuf->st_uid = ef->uid;
36 stbuf->st_gid = ef->gid;
37 stbuf->st_size = node->size;
38 stbuf->st_blocks = DIV_ROUND_UP(node->size, CLUSTER_SIZE(*ef->sb)) *
39 CLUSTER_SIZE(*ef->sb) / 512;
40 stbuf->st_mtime = node->mtime;
41 stbuf->st_atime = node->atime;
42 /* set ctime to mtime to ensure we don't break programs that rely on ctime
43 (e.g. rsync) */
44 stbuf->st_ctime = node->mtime;
45}
46
47void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n)
48{
49 if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0)
50 exfat_bug("failed to convert name to UTF-8");
51}
52
53uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
54{
55 uint16_t sum = 0;
56 int i;
57
58 for (i = 0; i < sizeof(struct exfat_entry); i++)
59 if (i != 2 && i != 3) /* skip checksum field itself */
60 sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
61 return sum;
62}
63
64uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
65{
66 int i;
67
68 for (i = 0; i < sizeof(struct exfat_entry); i++)
69 sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
70 return sum;
71}
72
73le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
74 const struct exfat_entry_meta2* meta2, const le16_t* name)
75{
76 uint16_t checksum;
77 const int name_entries = DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX);
78 int i;
79
80 checksum = exfat_start_checksum(meta1);
81 checksum = exfat_add_checksum(meta2, checksum);
82 for (i = 0; i < name_entries; i++)
83 {
84 struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
85 memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
86 EXFAT_ENAME_MAX * sizeof(le16_t));
87 checksum = exfat_add_checksum(&name_entry, checksum);
88 }
89 return cpu_to_le16(checksum);
90}
91
92uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
93{
94 size_t i;
95 uint32_t sum = 0;
96
97 for (i = 0; i < size; i++)
98 /* skip volume_state and allocated_percent fields */
99 if (i != 0x6a && i != 0x6b && i != 0x70)
100 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
101 return sum;
102}
103
104uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
105{
106 size_t i;
107
108 for (i = 0; i < size; i++)
109 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
110 return sum;
111}
112
113le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name)
114{
115 size_t i;
116 size_t length = utf16_length(name);
117 uint16_t hash = 0;
118
119 for (i = 0; i < length; i++)
120 {
121 uint16_t c = le16_to_cpu(name[i]);
122
123 /* convert to upper case */
124 if (c < ef->upcase_chars)
125 c = le16_to_cpu(ef->upcase[c]);
126
127 hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
128 hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
129 }
130 return cpu_to_le16(hash);
131}
132
133void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
134{
135 size_t i;
136 /* 16 EB (minus 1 byte) is the largest size that can be represented by
137 uint64_t */
138 const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
139 uint64_t divisor = 1;
140 uint64_t temp = 0;
141
142 for (i = 0; ; i++, divisor *= 1024)
143 {
144 temp = (value + divisor / 2) / divisor;
145
146 if (temp == 0)
147 break;
148 if (temp / 1024 * 1024 == temp)
149 continue;
150 if (temp < 10240)
151 break;
152 }
153 hb->value = temp;
154 hb->unit = units[i];
155}
156
157void exfat_print_info(const struct exfat_super_block* sb,
158 uint32_t free_clusters)
159{
160 struct exfat_human_bytes hb;
161 off64_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
162 off64_t avail_space = (off64_t) free_clusters * CLUSTER_SIZE(*sb);
163
164 printf("File system version %hhu.%hhu\n",
165 sb->version.major, sb->version.minor);
166 exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
167 printf("Sector size %10"PRIu64" %s\n", hb.value, hb.unit);
168 exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
169 printf("Cluster size %10"PRIu64" %s\n", hb.value, hb.unit);
170 exfat_humanize_bytes(total_space, &hb);
171 printf("Volume size %10"PRIu64" %s\n", hb.value, hb.unit);
172 exfat_humanize_bytes(total_space - avail_space, &hb);
173 printf("Used space %10"PRIu64" %s\n", hb.value, hb.unit);
174 exfat_humanize_bytes(avail_space, &hb);
175 printf("Available space %10"PRIu64" %s\n", hb.value, hb.unit);
176}