extras/volume_id/volume_id/util.c

   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 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE 1
  23 #endif
  24
  25 #ifdef HAVE_CONFIG_H
  26 #  include <config.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <errno.h>
  34 #include <ctype.h>
  35 #include <fcntl.h>
  36 #include <sys/stat.h>
  37 #include <asm/types.h>
  38
  39 #include "volume_id.h"
  40 #include "logging.h"
  41 #include "util.h"
  42
  43 static char *usage_to_string(enum volume_id_usage usage_id)
  44 {
  45         switch (usage_id) {
  46         case VOLUME_ID_FILESYSTEM:
  47                 return "filesystem";
  48         case VOLUME_ID_PARTITIONTABLE:
  49                 return "partitiontable";
  50         case VOLUME_ID_OTHER:
  51                 return "other";
  52         case VOLUME_ID_RAID:
  53                 return "raid";
  54         case VOLUME_ID_DISKLABEL:
  55                 return "disklabel";
  56         case VOLUME_ID_CRYPTO:
  57                 return "crypto";
  58         case VOLUME_ID_UNPROBED:
  59                 return "unprobed";
  60         case VOLUME_ID_UNUSED:
  61                 return "unused";
  62         }
  63         return NULL;
  64 }
  65
  66 void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
  67 {
  68         part->usage_id = usage_id;
  69         part->usage = usage_to_string(usage_id);
  70 }
  71
  72 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
  73 {
  74         id->usage_id = usage_id;
  75         id->usage = usage_to_string(usage_id);
  76 }
  77
  78 void volume_id_set_label_raw(struct volume_id *id, const __u8 *buf, unsigned int count)
  79 {
  80         memcpy(id->label_raw, buf, count);
  81         id->label_raw_len = count;
  82 }
  83
  84 void volume_id_set_label_string(struct volume_id *id, const __u8 *buf, unsigned int count)
  85 {
  86         unsigned int i;
  87
  88         memcpy(id->label, buf, count);
  89
  90         /* remove trailing whitespace */
  91         i = strnlen(id->label, count);
  92         while (i--) {
  93                 if (!isspace(id->label[i]))
  94                         break;
  95         }
  96         id->label[i+1] = '\0';
  97 }
  98
  99 void volume_id_set_label_unicode16(struct volume_id *id, const __u8 *buf, enum endian endianess, unsigned int count)
 100 {
 101         unsigned int i, j;
 102         __u16 c;
 103
 104         j = 0;
 105         for (i = 0; i + 2 <= count; i += 2) {
 106                 if (endianess == LE)
 107                         c = (buf[i+1] << 8) | buf[i];
 108                 else
 109                         c = (buf[i] << 8) | buf[i+1];
 110                 if (c == 0) {
 111                         id->label[j] = '\0';
 112                         break;
 113                 } else if (c < 0x80) {
 114                         id->label[j++] = (__u8) c;
 115                 } else if (c < 0x800) {
 116                         id->label[j++] = (__u8) (0xc0 | (c >> 6));
 117                         id->label[j++] = (__u8) (0x80 | (c & 0x3f));
 118                 } else {
 119                         id->label[j++] = (__u8) (0xe0 | (c >> 12));
 120                         id->label[j++] = (__u8) (0x80 | ((c >> 6) & 0x3f));
 121                         id->label[j++] = (__u8) (0x80 | (c & 0x3f));
 122                 }
 123         }
 124 }
 125
 126 void volume_id_set_uuid(struct volume_id *id, const __u8 *buf, enum uuid_format format)
 127 {
 128         unsigned int i;
 129         unsigned int count = 0;
 130
 131         switch(format) {
 132         case UUID_DOS:
 133                 count = 4;
 134                 break;
 135         case UUID_NTFS:
 136         case UUID_HFS:
 137                 count = 8;
 138                 break;
 139         case UUID_DCE:
 140                 count = 16;
 141         }
 142         memcpy(id->uuid_raw, buf, count);
 143
 144         /* if set, create string in the same format, the native platform uses */
 145         for (i = 0; i < count; i++)
 146                 if (buf[i] != 0)
 147                         goto set;
 148         return;
 149
 150 set:
 151         switch(format) {
 152         case UUID_DOS:
 153                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 154                         buf[3], buf[2], buf[1], buf[0]);
 155                 break;
 156         case UUID_NTFS:
 157                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 158                         buf[7], buf[6], buf[5], buf[4],
 159                         buf[3], buf[2], buf[1], buf[0]);
 160                 break;
 161         case UUID_HFS:
 162                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 163                         buf[0], buf[1], buf[2], buf[3],
 164                         buf[4], buf[5], buf[6], buf[7]);
 165                 break;
 166         case UUID_DCE:
 167                 sprintf(id->uuid,
 168                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 169                         buf[0], buf[1], buf[2], buf[3],
 170                         buf[4], buf[5],
 171                         buf[6], buf[7],
 172                         buf[8], buf[9],
 173                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 174                 break;
 175         }
 176 }
 177
 178 __u8 *volume_id_get_buffer(struct volume_id *id, __u64 off, unsigned int len)
 179 {
 180         unsigned int buf_len;
 181
 182         dbg("get buffer off 0x%llx(%llu), len 0x%x", off, off, len);
 183         /* check if requested area fits in superblock buffer */
 184         if (off + len <= SB_BUFFER_SIZE) {
 185                 if (id->sbbuf == NULL) {
 186                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 187                         if (id->sbbuf == NULL)
 188                                 return NULL;
 189                 }
 190
 191                 /* check if we need to read */
 192                 if ((off + len) > id->sbbuf_len) {
 193                         dbg("read sbbuf len:0x%llx", off + len);
 194                         lseek(id->fd, 0, SEEK_SET);
 195                         buf_len = read(id->fd, id->sbbuf, off + len);
 196                         dbg("got 0x%x (%i) bytes", buf_len, buf_len);
 197                         id->sbbuf_len = buf_len;
 198                         if (buf_len < off + len)
 199                                 return NULL;
 200                 }
 201
 202                 return &(id->sbbuf[off]);
 203         } else {
 204                 if (len > SEEK_BUFFER_SIZE) {
 205                         dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 206                         return NULL;
 207                 }
 208
 209                 /* get seek buffer */
 210                 if (id->seekbuf == NULL) {
 211                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 212                         if (id->seekbuf == NULL)
 213                                 return NULL;
 214                 }
 215
 216                 /* check if we need to read */
 217                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 218                         dbg("read seekbuf off:0x%llx len:0x%x", off, len);
 219                         if (lseek(id->fd, off, SEEK_SET) == -1)
 220                                 return NULL;
 221                         buf_len = read(id->fd, id->seekbuf, len);
 222                         dbg("got 0x%x (%i) bytes", buf_len, buf_len);
 223                         id->seekbuf_off = off;
 224                         id->seekbuf_len = buf_len;
 225                         if (buf_len < len) {
 226                                 dbg("requested 0x%x bytes, got only 0x%x bytes", len, buf_len);
 227                                 return NULL;
 228                         }
 229                 }
 230
 231                 return &(id->seekbuf[off - id->seekbuf_off]);
 232         }
 233 }
 234
 235 void volume_id_free_buffer(struct volume_id *id)
 236 {
 237         if (id->sbbuf != NULL) {
 238                 free(id->sbbuf);
 239                 id->sbbuf = NULL;
 240                 id->sbbuf_len = 0;
 241         }
 242         if (id->seekbuf != NULL) {
 243                 free(id->seekbuf);
 244                 id->seekbuf = NULL;
 245                 id->seekbuf_len = 0;
 246         }
 247 }