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