source: branches/3.2/mindi-busybox/util-linux/volume_id/util.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 6.6 KB
Line 
1/*
2 * volume_id - reads filesystem label and uuid
3 *
4 * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
5 *
6 *  This library is free software; you can redistribute it and/or
7 *  modify it under the terms of the GNU Lesser General Public
8 *  License as published by the Free Software Foundation; either
9 *  version 2.1 of the License, or (at your option) any later version.
10 *
11 *  This library is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 *  Lesser General Public License for more details.
15 *
16 *  You should have received a copy of the GNU Lesser General Public
17 *  License along with this library; if not, write to the Free Software
18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include "volume_id_internal.h"
22
23void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
24{
25    unsigned i, j;
26    unsigned c;
27
28    j = 0;
29    for (i = 0; i + 2 <= count; i += 2) {
30        if (endianess == LE)
31            c = (buf[i+1] << 8) | buf[i];
32        else
33            c = (buf[i] << 8) | buf[i+1];
34        if (c == 0)
35            break;
36        if (j+1 >= len)
37            break;
38        if (c < 0x80) {
39            /* 0xxxxxxx */
40        } else {
41            uint8_t topbits = 0xc0;
42            if (j+2 >= len)
43                break;
44            if (c < 0x800) {
45                /* 110yyyxx 10xxxxxx */
46            } else {
47                if (j+3 >= len)
48                    break;
49                /* 1110yyyy 10yyyyxx 10xxxxxx */
50                str[j++] = (uint8_t) (0xe0 | (c >> 12));
51                topbits = 0x80;
52            }
53            str[j++] = (uint8_t) (topbits | ((c >> 6) & 0x3f));
54            c = 0x80 | (c & 0x3f);
55        }
56        str[j++] = (uint8_t) c;
57    }
58    str[j] = '\0';
59}
60
61#ifdef UNUSED
62static const char *usage_to_string(enum volume_id_usage usage_id)
63{
64    switch (usage_id) {
65    case VOLUME_ID_FILESYSTEM:
66        return "filesystem";
67    case VOLUME_ID_PARTITIONTABLE:
68        return "partitiontable";
69    case VOLUME_ID_OTHER:
70        return "other";
71    case VOLUME_ID_RAID:
72        return "raid";
73    case VOLUME_ID_DISKLABEL:
74        return "disklabel";
75    case VOLUME_ID_CRYPTO:
76        return "crypto";
77    case VOLUME_ID_UNPROBED:
78        return "unprobed";
79    case VOLUME_ID_UNUSED:
80        return "unused";
81    }
82    return NULL;
83}
84
85void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
86{
87    part->usage_id = usage_id;
88    part->usage = usage_to_string(usage_id);
89}
90
91void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
92{
93    id->usage_id = usage_id;
94    id->usage = usage_to_string(usage_id);
95}
96
97void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
98{
99    memcpy(id->label_raw, buf, count);
100    id->label_raw_len = count;
101}
102#endif
103
104#ifdef NOT_NEEDED
105static size_t strnlen(const char *s, size_t maxlen)
106{
107    size_t i;
108    if (!maxlen) return 0;
109    if (!s) return 0;
110    for (i = 0; *s && i < maxlen; ++s) ++i;
111    return i;
112}
113#endif
114
115void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
116{
117    unsigned i;
118
119    memcpy(id->label, buf, count);
120
121    /* remove trailing whitespace */
122    i = strnlen(id->label, count);
123    while (i--) {
124        if (!isspace(id->label[i]))
125            break;
126    }
127    id->label[i+1] = '\0';
128}
129
130void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
131{
132    volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
133}
134
135void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
136{
137    unsigned i;
138    unsigned count = (format == UUID_DCE_STRING ? VOLUME_ID_UUID_SIZE : 4 << format);
139
140//  memcpy(id->uuid_raw, buf, count);
141//  id->uuid_raw_len = count;
142
143    /* if set, create string in the same format, the native platform uses */
144    for (i = 0; i < count; i++)
145        if (buf[i] != 0)
146            goto set;
147    return; /* all bytes are zero, leave it empty ("") */
148
149set:
150    switch (format) {
151    case UUID_DOS:
152        sprintf(id->uuid, "%02X%02X-%02X%02X",
153            buf[3], buf[2], buf[1], buf[0]);
154        break;
155    case UUID_NTFS:
156        sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
157            buf[7], buf[6], buf[5], buf[4],
158            buf[3], buf[2], buf[1], buf[0]);
159        break;
160    case UUID_DCE:
161        sprintf(id->uuid,
162            "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
163            buf[0], buf[1], buf[2], buf[3],
164            buf[4], buf[5],
165            buf[6], buf[7],
166            buf[8], buf[9],
167            buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
168        break;
169    case UUID_DCE_STRING:
170        memcpy(id->uuid, buf, count);
171        id->uuid[count] = '\0';
172        break;
173    }
174}
175
176/* Do not use xlseek here. With it, single corrupted filesystem
177 * may result in attempt to seek past device -> exit.
178 * It's better to ignore such fs and continue.  */
179void *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
180{
181    uint8_t *dst;
182    unsigned small_off;
183    ssize_t read_len;
184
185    dbg("get buffer off 0x%llx(%llu), len 0x%zx",
186        (unsigned long long) off, (unsigned long long) off, len);
187
188    /* check if requested area fits in superblock buffer */
189    if (off + len <= SB_BUFFER_SIZE
190     /* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */
191    ) {
192        if (id->sbbuf == NULL) {
193            id->sbbuf = xmalloc(SB_BUFFER_SIZE);
194        }
195        small_off = off;
196        dst = id->sbbuf;
197
198        /* check if we need to read */
199        len += off;
200        if (len <= id->sbbuf_len)
201            goto ret; /* we already have it */
202
203        dbg("read sbbuf len:0x%x", (unsigned) len);
204        id->sbbuf_len = len;
205        off = 0;
206        goto do_read;
207    }
208
209    if (len > SEEK_BUFFER_SIZE) {
210        dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
211        return NULL;
212    }
213    dst = id->seekbuf;
214
215    /* check if we need to read */
216    if ((off >= id->seekbuf_off)
217     && ((off + len) <= (id->seekbuf_off + id->seekbuf_len))
218    ) {
219        small_off = off - id->seekbuf_off; /* can't overflow */
220        goto ret; /* we already have it */
221    }
222
223    id->seekbuf_off = off;
224    id->seekbuf_len = len;
225    id->seekbuf = xrealloc(id->seekbuf, len);
226    small_off = 0;
227    dst = id->seekbuf;
228    dbg("read seekbuf off:0x%llx len:0x%zx",
229                (unsigned long long) off, len);
230 do_read:
231    if (lseek(id->fd, off, SEEK_SET) != off) {
232        dbg("seek(0x%llx) failed", (unsigned long long) off);
233        goto err;
234    }
235    read_len = full_read(id->fd, dst, len);
236    if (read_len != len) {
237        dbg("requested 0x%x bytes, got 0x%x bytes",
238                (unsigned) len, (unsigned) read_len);
239 err:
240        /* No filesystem can be this tiny. It's most likely
241         * non-associated loop device, empty drive and so on.
242         * Flag it, making it possible to short circuit future
243         * accesses. Rationale:
244         * users complained of slow blkid due to empty floppy drives.
245         */
246        if (off < 64*1024)
247            id->error = 1;
248        /* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing. */
249        volume_id_free_buffer(id);
250        return NULL;
251    }
252 ret:
253    return dst + small_off;
254}
255
256void volume_id_free_buffer(struct volume_id *id)
257{
258    free(id->sbbuf);
259    id->sbbuf = NULL;
260    id->sbbuf_len = 0;
261    free(id->seekbuf);
262    id->seekbuf = NULL;
263    id->seekbuf_len = 0;
264    id->seekbuf_off = 0; /* paranoia */
265}
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