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 void volume_id_set_unicode16(char *str, unsigned int len, const __u8 *buf, enum endian endianess, unsigned int count)
  44 {
  45         unsigned int i, j;
  46         __u16 c;
  47
  48         j = 0;
  49         for (i = 0; i + 2 <= count; i += 2) {
  50                 if (endianess == LE)
  51                         c = (buf[i+1] << 8) | buf[i];
  52                 else
  53                         c = (buf[i] << 8) | buf[i+1];
  54                 if (c == 0) {
  55                         str[j] = '\0';
  56                         break;
  57                 } else if (c < 0x80) {
  58                         if (j+1 >= len)
  59                                 break;
  60                         str[j++] = (__u8) c;
  61                 } else if (c < 0x800) {
  62                         if (j+2 >= len)
  63                                 break;
  64                         str[j++] = (__u8) (0xc0 | (c >> 6));
  65                         str[j++] = (__u8) (0x80 | (c & 0x3f));
  66                 } else {
  67                         if (j+3 >= len)
  68                                 break;
  69                         str[j++] = (__u8) (0xe0 | (c >> 12));
  70                         str[j++] = (__u8) (0x80 | ((c >> 6) & 0x3f));
  71                         str[j++] = (__u8) (0x80 | (c & 0x3f));
  72                 }
  73         }
  74         str[j] = '\0';
  75 }
  76
  77 static char *usage_to_string(enum volume_id_usage usage_id)
  78 {
  79         switch (usage_id) {
  80         case VOLUME_ID_FILESYSTEM:
  81                 return "filesystem";
  82         case VOLUME_ID_PARTITIONTABLE:
  83                 return "partitiontable";
  84         case VOLUME_ID_OTHER:
  85                 return "other";
  86         case VOLUME_ID_RAID:
  87                 return "raid";
  88         case VOLUME_ID_DISKLABEL:
  89                 return "disklabel";
  90         case VOLUME_ID_CRYPTO:
  91                 return "crypto";
  92         case VOLUME_ID_UNPROBED:
  93                 return "unprobed";
  94         case VOLUME_ID_UNUSED:
  95                 return "unused";
  96         }
  97         return NULL;
  98 }
  99
 100 void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
 101 {
 102         part->usage_id = usage_id;
 103         part->usage = usage_to_string(usage_id);
 104 }
 105
 106 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
 107 {
 108         id->usage_id = usage_id;
 109         id->usage = usage_to_string(usage_id);
 110 }
 111
 112 void volume_id_set_label_raw(struct volume_id *id, const __u8 *buf, unsigned int count)
 113 {
 114         memcpy(id->label_raw, buf, count);
 115         id->label_raw_len = count;
 116 }
 117
 118 void volume_id_set_label_string(struct volume_id *id, const __u8 *buf, unsigned int count)
 119 {
 120         unsigned int i;
 121
 122         memcpy(id->label, buf, count);
 123
 124         /* remove trailing whitespace */
 125         i = strnlen(id->label, count);
 126         while (i--) {
 127                 if (!isspace(id->label[i]))
 128                         break;
 129         }
 130         id->label[i+1] = '\0';
 131 }
 132
 133 void volume_id_set_label_unicode16(struct volume_id *id, const __u8 *buf, enum endian endianess, unsigned int count)
 134 {
 135          volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
 136 }
 137
 138 void volume_id_set_uuid(struct volume_id *id, const __u8 *buf, enum uuid_format format)
 139 {
 140         unsigned int i;
 141         unsigned int count = 0;
 142
 143         switch(format) {
 144         case UUID_DOS:
 145                 count = 4;
 146                 break;
 147         case UUID_NTFS:
 148         case UUID_HFS:
 149                 count = 8;
 150                 break;
 151         case UUID_DCE:
 152                 count = 16;
 153                 break;
 154         case UUID_DCE_STRING:
 155                 count = 36;
 156                 break;
 157         }
 158         memcpy(id->uuid_raw, buf, count);
 159         id->uuid_raw_len = count;
 160
 161         /* if set, create string in the same format, the native platform uses */
 162         for (i = 0; i < count; i++)
 163                 if (buf[i] != 0)
 164                         goto set;
 165         return;
 166
 167 set:
 168         switch(format) {
 169         case UUID_DOS:
 170                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 171                         buf[3], buf[2], buf[1], buf[0]);
 172                 break;
 173         case UUID_NTFS:
 174                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 175                         buf[7], buf[6], buf[5], buf[4],
 176                         buf[3], buf[2], buf[1], buf[0]);
 177                 break;
 178         case UUID_HFS:
 179                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 180                         buf[0], buf[1], buf[2], buf[3],
 181                         buf[4], buf[5], buf[6], buf[7]);
 182                 break;
 183         case UUID_DCE:
 184                 sprintf(id->uuid,
 185                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 186                         buf[0], buf[1], buf[2], buf[3],
 187                         buf[4], buf[5],
 188                         buf[6], buf[7],
 189                         buf[8], buf[9],
 190                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 191                 break;
 192         case UUID_DCE_STRING:
 193                 memcpy(id->uuid, buf, count);
 194                 id->uuid[count] = '\0';
 195                 break;
 196         }
 197 }
 198
 199 __u8 *volume_id_get_buffer(struct volume_id *id, __u64 off, unsigned int len)
 200 {
 201         unsigned int buf_len;
 202
 203         dbg("get buffer off 0x%llx(%llu), len 0x%x", (unsigned long long) off, (unsigned long long) off, len);
 204         /* check if requested area fits in superblock buffer */
 205         if (off + len <= SB_BUFFER_SIZE) {
 206                 if (id->sbbuf == NULL) {
 207                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 208                         if (id->sbbuf == NULL)
 209                                 return NULL;
 210                 }
 211
 212                 /* check if we need to read */
 213                 if ((off + len) > id->sbbuf_len) {
 214                         dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
 215                         lseek(id->fd, 0, SEEK_SET);
 216                         buf_len = read(id->fd, id->sbbuf, off + len);
 217                         dbg("got 0x%x (%i) bytes", buf_len, buf_len);
 218                         id->sbbuf_len = buf_len;
 219                         if (buf_len < off + len)
 220                                 return NULL;
 221                 }
 222
 223                 return &(id->sbbuf[off]);
 224         } else {
 225                 if (len > SEEK_BUFFER_SIZE) {
 226                         dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 227                         return NULL;
 228                 }
 229
 230                 /* get seek buffer */
 231                 if (id->seekbuf == NULL) {
 232                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 233                         if (id->seekbuf == NULL)
 234                                 return NULL;
 235                 }
 236
 237                 /* check if we need to read */
 238                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 239                         dbg("read seekbuf off:0x%llx len:0x%x", (unsigned long long) off, len);
 240                         if (lseek(id->fd, off, SEEK_SET) == -1)
 241                                 return NULL;
 242                         buf_len = read(id->fd, id->seekbuf, len);
 243                         dbg("got 0x%x (%i) bytes", buf_len, buf_len);
 244                         id->seekbuf_off = off;
 245                         id->seekbuf_len = buf_len;
 246                         if (buf_len < len) {
 247                                 dbg("requested 0x%x bytes, got only 0x%x bytes", len, buf_len);
 248                                 return NULL;
 249                         }
 250                 }
 251
 252                 return &(id->seekbuf[off - id->seekbuf_off]);
 253         }
 254 }
 255
 256 void volume_id_free_buffer(struct volume_id *id)
 257 {
 258         if (id->sbbuf != NULL) {
 259                 free(id->sbbuf);
 260                 id->sbbuf = NULL;
 261                 id->sbbuf_len = 0;
 262         }
 263         if (id->seekbuf != NULL) {
 264                 free(id->seekbuf);
 265                 id->seekbuf = NULL;
 266                 id->seekbuf_len = 0;
 267         }
 268 }