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
  38 #include "volume_id.h"
  39 #include "logging.h"
  40 #include "util.h"
  41
  42 void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
  43 {
  44         unsigned int i, j;
  45         uint16_t c;
  46
  47         j = 0;
  48         for (i = 0; i + 2 <= count; i += 2) {
  49                 if (endianess == LE)
  50                         c = (buf[i+1] << 8) | buf[i];
  51                 else
  52                         c = (buf[i] << 8) | buf[i+1];
  53                 if (c == 0) {
  54                         str[j] = '\0';
  55                         break;
  56                 } else if (c < 0x80) {
  57                         if (j+1 >= len)
  58                                 break;
  59                         str[j++] = (uint8_t) c;
  60                 } else if (c < 0x800) {
  61                         if (j+2 >= len)
  62                                 break;
  63                         str[j++] = (uint8_t) (0xc0 | (c >> 6));
  64                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  65                 } else {
  66                         if (j+3 >= len)
  67                                 break;
  68                         str[j++] = (uint8_t) (0xe0 | (c >> 12));
  69                         str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
  70                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  71                 }
  72         }
  73         str[j] = '\0';
  74 }
  75
  76 static char *usage_to_string(enum volume_id_usage usage_id)
  77 {
  78         switch (usage_id) {
  79         case VOLUME_ID_FILESYSTEM:
  80                 return "filesystem";
  81         case VOLUME_ID_PARTITIONTABLE:
  82                 return "partitiontable";
  83         case VOLUME_ID_OTHER:
  84                 return "other";
  85         case VOLUME_ID_RAID:
  86                 return "raid";
  87         case VOLUME_ID_DISKLABEL:
  88                 return "disklabel";
  89         case VOLUME_ID_CRYPTO:
  90                 return "crypto";
  91         case VOLUME_ID_UNPROBED:
  92                 return "unprobed";
  93         case VOLUME_ID_UNUSED:
  94                 return "unused";
  95         }
  96         return NULL;
  97 }
  98
  99 void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
 100 {
 101         part->usage_id = usage_id;
 102         part->usage = usage_to_string(usage_id);
 103 }
 104
 105 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
 106 {
 107         id->usage_id = usage_id;
 108         id->usage = usage_to_string(usage_id);
 109 }
 110
 111 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
 112 {
 113         memcpy(id->label_raw, buf, count);
 114         id->label_raw_len = count;
 115 }
 116
 117 static size_t my_strnlen(const char *s, size_t max) {
 118     const char *p = s;
 119     for (; *p && max--; ++p);
 120     return(p - s);
 121 }
 122
 123 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 124 {
 125         unsigned int i;
 126
 127         memcpy(id->label, buf, count);
 128
 129         /* remove trailing whitespace */
 130         i = my_strnlen(id->label, count);
 131         while (i--) {
 132                 if (!isspace(id->label[i]))
 133                         break;
 134         }
 135         id->label[i+1] = '\0';
 136 }
 137
 138 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 139 {
 140          volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
 141 }
 142
 143 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
 144 {
 145         unsigned int i;
 146         unsigned int count = 0;
 147
 148         switch(format) {
 149         case UUID_DOS:
 150                 count = 4;
 151                 break;
 152         case UUID_NTFS:
 153         case UUID_HFS:
 154                 count = 8;
 155                 break;
 156         case UUID_DCE:
 157                 count = 16;
 158                 break;
 159         case UUID_DCE_STRING:
 160                 count = 36;
 161                 break;
 162         }
 163         memcpy(id->uuid_raw, buf, count);
 164         id->uuid_raw_len = count;
 165
 166         /* if set, create string in the same format, the native platform uses */
 167         for (i = 0; i < count; i++)
 168                 if (buf[i] != 0)
 169                         goto set;
 170         return;
 171
 172 set:
 173         switch(format) {
 174         case UUID_DOS:
 175                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 176                         buf[3], buf[2], buf[1], buf[0]);
 177                 break;
 178         case UUID_NTFS:
 179                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 180                         buf[7], buf[6], buf[5], buf[4],
 181                         buf[3], buf[2], buf[1], buf[0]);
 182                 break;
 183         case UUID_HFS:
 184                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 185                         buf[0], buf[1], buf[2], buf[3],
 186                         buf[4], buf[5], buf[6], buf[7]);
 187                 break;
 188         case UUID_DCE:
 189                 sprintf(id->uuid,
 190                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 191                         buf[0], buf[1], buf[2], buf[3],
 192                         buf[4], buf[5],
 193                         buf[6], buf[7],
 194                         buf[8], buf[9],
 195                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 196                 break;
 197         case UUID_DCE_STRING:
 198                 memcpy(id->uuid, buf, count);
 199                 id->uuid[count] = '\0';
 200                 break;
 201         }
 202 }
 203
 204 uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 205 {
 206         size_t buf_len;
 207
 208         dbg("get buffer off 0x%llx(%llu), len 0x%zx", (unsigned long long) off, (unsigned long long) off, len);
 209         /* check if requested area fits in superblock buffer */
 210         if (off + len <= SB_BUFFER_SIZE) {
 211                 if (id->sbbuf == NULL) {
 212                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 213                         if (id->sbbuf == NULL)
 214                                 return NULL;
 215                 }
 216
 217                 /* check if we need to read */
 218                 if ((off + len) > id->sbbuf_len) {
 219                         dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
 220                         lseek(id->fd, 0, SEEK_SET);
 221                         buf_len = read(id->fd, id->sbbuf, off + len);
 222                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 223                         id->sbbuf_len = buf_len;
 224                         if (buf_len < off + len)
 225                                 return NULL;
 226                 }
 227
 228                 return &(id->sbbuf[off]);
 229         } else {
 230                 if (len > SEEK_BUFFER_SIZE) {
 231                         dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 232                         return NULL;
 233                 }
 234
 235                 /* get seek buffer */
 236                 if (id->seekbuf == NULL) {
 237                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 238                         if (id->seekbuf == NULL)
 239                                 return NULL;
 240                 }
 241
 242                 /* check if we need to read */
 243                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 244                         dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
 245                         if (lseek(id->fd, off, SEEK_SET) == -1)
 246                                 return NULL;
 247                         buf_len = read(id->fd, id->seekbuf, len);
 248                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 249                         id->seekbuf_off = off;
 250                         id->seekbuf_len = buf_len;
 251                         if (buf_len < len) {
 252                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
 253                                 return NULL;
 254                         }
 255                 }
 256
 257                 return &(id->seekbuf[off - id->seekbuf_off]);
 258         }
 259 }
 260
 261 void volume_id_free_buffer(struct volume_id *id)
 262 {
 263         if (id->sbbuf != NULL) {
 264                 free(id->sbbuf);
 265                 id->sbbuf = NULL;
 266                 id->sbbuf_len = 0;
 267         }
 268         if (id->seekbuf != NULL) {
 269                 free(id->seekbuf);
 270                 id->seekbuf = NULL;
 271                 id->seekbuf_len = 0;
 272         }
 273 }