extras/volume_id/lib/util.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2005-2007 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef _GNU_SOURCE
  21 #define _GNU_SOURCE 1
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <ctype.h>
  30 #include <fcntl.h>
  31 #include <sys/stat.h>
  32
  33 #include "libvolume_id.h"
  34 #include "libvolume_id-private.h"
  35
  36 /* count of characters used to encode one unicode char */
  37 static int utf8_encoded_expected_len(const char *str)
  38 {
  39         unsigned char c = (unsigned char)str[0];
  40
  41         if (c < 0x80)
  42                 return 1;
  43         if ((c & 0xe0) == 0xc0)
  44                 return 2;
  45         if ((c & 0xf0) == 0xe0)
  46                 return 3;
  47         if ((c & 0xf8) == 0xf0)
  48                 return 4;
  49         if ((c & 0xfc) == 0xf8)
  50                 return 5;
  51         if ((c & 0xfe) == 0xfc)
  52                 return 6;
  53         return 0;
  54 }
  55
  56 /* decode one unicode char */
  57 static int utf8_encoded_to_unichar(const char *str)
  58 {
  59         int unichar;
  60         int len;
  61         int i;
  62
  63         len = utf8_encoded_expected_len(str);
  64         switch (len) {
  65         case 1:
  66                 return (int)str[0];
  67         case 2:
  68                 unichar = str[0] & 0x1f;
  69                 break;
  70         case 3:
  71                 unichar = (int)str[0] & 0x0f;
  72                 break;
  73         case 4:
  74                 unichar = (int)str[0] & 0x07;
  75                 break;
  76         case 5:
  77                 unichar = (int)str[0] & 0x03;
  78                 break;
  79         case 6:
  80                 unichar = (int)str[0] & 0x01;
  81                 break;
  82         default:
  83                 return -1;
  84         }
  85
  86         for (i = 1; i < len; i++) {
  87                 if (((int)str[i] & 0xc0) != 0x80)
  88                         return -1;
  89                 unichar <<= 6;
  90                 unichar |= (int)str[i] & 0x3f;
  91         }
  92
  93         return unichar;
  94 }
  95
  96 /* expected size used to encode one unicode char */
  97 static int utf8_unichar_to_encoded_len(int unichar)
  98 {
  99         if (unichar < 0x80)
 100                 return 1;
 101         if (unichar < 0x800)
 102                 return 2;
 103         if (unichar < 0x10000)
 104                 return 3;
 105         if (unichar < 0x200000)
 106                 return 4;
 107         if (unichar < 0x4000000)
 108                 return 5;
 109         return 6;
 110 }
 111
 112 /* check if unicode char has a valid numeric range */
 113 static int utf8_unichar_valid_range(int unichar)
 114 {
 115         if (unichar > 0x10ffff)
 116                 return 0;
 117         if ((unichar & 0xfffff800) == 0xd800)
 118                 return 0;
 119         if ((unichar > 0xfdcf) && (unichar < 0xfdf0))
 120                 return 0;
 121         if ((unichar & 0xffff) == 0xffff)
 122                 return 0;
 123         return 1;
 124 }
 125
 126 /* validate one encoded unicode char and return its length */
 127 int volume_id_utf8_encoded_valid_unichar(const char *str)
 128 {
 129         int len;
 130         int unichar;
 131         int i;
 132
 133         len = utf8_encoded_expected_len(str);
 134         if (len == 0)
 135                 return -1;
 136
 137         /* ascii is valid */
 138         if (len == 1)
 139                 return 1;
 140
 141         /* check if expected encoded chars are available */
 142         for (i = 0; i < len; i++)
 143                 if ((str[i] & 0x80) != 0x80)
 144                         return -1;
 145
 146         unichar = utf8_encoded_to_unichar(str);
 147
 148         /* check if encoded length matches encoded value */
 149         if (utf8_unichar_to_encoded_len(unichar) != len)
 150                 return -1;
 151
 152         /* check if value has valid range */
 153         if (!utf8_unichar_valid_range(unichar))
 154                 return -1;
 155
 156         return len;
 157 }
 158
 159 size_t volume_id_set_unicode16(uint8_t *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
 160 {
 161         size_t i, j;
 162         uint16_t c;
 163
 164         j = 0;
 165         for (i = 0; i + 2 <= count; i += 2) {
 166                 if (endianess == LE)
 167                         c = (buf[i+1] << 8) | buf[i];
 168                 else
 169                         c = (buf[i] << 8) | buf[i+1];
 170                 if (c == 0) {
 171                         str[j] = '\0';
 172                         break;
 173                 } else if (c < 0x80) {
 174                         if (j+1 >= len)
 175                                 break;
 176                         str[j++] = (uint8_t) c;
 177                 } else if (c < 0x800) {
 178                         if (j+2 >= len)
 179                                 break;
 180                         str[j++] = (uint8_t) (0xc0 | (c >> 6));
 181                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 182                 } else {
 183                         if (j+3 >= len)
 184                                 break;
 185                         str[j++] = (uint8_t) (0xe0 | (c >> 12));
 186                         str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
 187                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 188                 }
 189         }
 190         str[j] = '\0';
 191         return j;
 192 }
 193
 194 static char *usage_to_string(enum volume_id_usage usage_id)
 195 {
 196         switch (usage_id) {
 197         case VOLUME_ID_FILESYSTEM:
 198                 return "filesystem";
 199         case VOLUME_ID_OTHER:
 200                 return "other";
 201         case VOLUME_ID_RAID:
 202                 return "raid";
 203         case VOLUME_ID_DISKLABEL:
 204                 return "disklabel";
 205         case VOLUME_ID_CRYPTO:
 206                 return "crypto";
 207         case VOLUME_ID_UNPROBED:
 208                 return "unprobed";
 209         case VOLUME_ID_UNUSED:
 210                 return "unused";
 211         }
 212         return NULL;
 213 }
 214
 215 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
 216 {
 217         id->usage_id = usage_id;
 218         id->usage = usage_to_string(usage_id);
 219 }
 220
 221 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
 222 {
 223         if (count > sizeof(id->label_raw))
 224                 count = sizeof(id->label_raw);
 225
 226         memcpy(id->label_raw, buf, count);
 227         id->label_raw_len = count;
 228 }
 229
 230 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 231 {
 232         size_t i;
 233
 234         if (count >= sizeof(id->label))
 235                 count = sizeof(id->label)-1;
 236
 237         memcpy(id->label, buf, count);
 238         id->label[count] = '\0';
 239
 240         /* remove trailing whitespace */
 241         i = strnlen(id->label, count);
 242         while (i--) {
 243                 if (!isspace(id->label[i]))
 244                         break;
 245         }
 246         id->label[i+1] = '\0';
 247 }
 248
 249 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 250 {
 251         if (count >= sizeof(id->label))
 252                 count = sizeof(id->label)-1;
 253
 254          volume_id_set_unicode16((uint8_t *)id->label, sizeof(id->label), buf, endianess, count);
 255 }
 256
 257 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, size_t len, enum uuid_format format)
 258 {
 259         unsigned int i;
 260         unsigned int count = 0;
 261
 262         if (len > sizeof(id->uuid_raw))
 263                 len = sizeof(id->uuid_raw);
 264
 265         switch(format) {
 266         case UUID_STRING:
 267                 count = len;
 268                 break;
 269         case UUID_HEX_STRING:
 270                 count = len;
 271                 break;
 272         case UUID_DOS:
 273                 count = 4;
 274                 break;
 275         case UUID_64BIT_LE:
 276                 count = 8;
 277                 break;
 278         case UUID_DCE:
 279                 count = 16;
 280                 break;
 281         case UUID_MD:
 282                 count = 35;
 283                 break;
 284         case UUID_LVM:
 285                 count = 32;
 286                 break;
 287         }
 288         memcpy(id->uuid_raw, buf, count);
 289         id->uuid_raw_len = count;
 290
 291         /* if set, create string in the same format, the native platform uses */
 292         for (i = 0; i < count; i++)
 293                 if (buf[i] != 0)
 294                         goto set;
 295         return;
 296
 297 set:
 298         switch(format) {
 299         case UUID_DOS:
 300                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 301                         buf[3], buf[2], buf[1], buf[0]);
 302                 break;
 303         case UUID_64BIT_LE:
 304                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 305                         buf[7], buf[6], buf[5], buf[4],
 306                         buf[3], buf[2], buf[1], buf[0]);
 307                 break;
 308         case UUID_DCE:
 309                 sprintf(id->uuid,
 310                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 311                         buf[0], buf[1], buf[2], buf[3],
 312                         buf[4], buf[5],
 313                         buf[6], buf[7],
 314                         buf[8], buf[9],
 315                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 316                 break;
 317         case UUID_HEX_STRING:
 318                 /* translate A..F to a..f */
 319                 memcpy(id->uuid, buf, count);
 320                 for (i = 0; i < count; i++)
 321                         if (id->uuid[i] >= 'A' && id->uuid[i] <= 'F')
 322                                 id->uuid[i] = (id->uuid[i] - 'A') + 'a';
 323                 id->uuid[count] = '\0';
 324                 break;
 325         case UUID_STRING:
 326                 memcpy(id->uuid, buf, count);
 327                 id->uuid[count] = '\0';
 328                 break;
 329         case UUID_MD:
 330                 sprintf(id->uuid,
 331                         "%02x%02x%02x%02x:%02x%02x%02x%02x:%02x%02x%02x%02x:%02x%02x%02x%02x",
 332                         buf[0], buf[1], buf[2], buf[3],
 333                         buf[4], buf[5], buf[6], buf[7],
 334                         buf[8], buf[9], buf[10], buf[11],
 335                         buf[12], buf[13], buf[14],buf[15]);
 336                 break;
 337         case UUID_LVM:
 338                 sprintf(id->uuid,
 339                         "%c%c%c%c%c%c-%c%c%c%c-%c%c%c%c-%c%c%c%c-%c%c%c%c-%c%c%c%c-%c%c%c%c%c%c",
 340                         buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
 341                         buf[6], buf[7], buf[8], buf[9],
 342                         buf[10], buf[11], buf[12], buf[13],
 343                         buf[14], buf[15], buf[16], buf[17],
 344                         buf[18], buf[19], buf[20], buf[21],
 345                         buf[22], buf[23], buf[24], buf[25],
 346                         buf[26], buf[27], buf[28], buf[29], buf[30], buf[31]);
 347                 break;
 348         }
 349 }
 350
 351 uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 352 {
 353         ssize_t buf_len;
 354
 355         info("get buffer off 0x%" PRIx64 "(%" PRIu64 "), len 0x%zx\n", off, off, len);
 356         /* check if requested area fits in superblock buffer */
 357         if (off + len <= SB_BUFFER_SIZE) {
 358                 if (id->sbbuf == NULL) {
 359                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 360                         if (id->sbbuf == NULL) {
 361                                 dbg("error malloc\n");
 362                                 return NULL;
 363                         }
 364                 }
 365
 366                 /* check if we need to read */
 367                 if ((off + len) > id->sbbuf_len) {
 368                         info("read sbbuf len:0x%" PRIx64 "\n", (off + len));
 369                         if (lseek(id->fd, 0, SEEK_SET) < 0) {
 370                                 dbg("lseek failed (%s)\n", strerror(errno));
 371                                 return NULL;
 372                         }
 373                         buf_len = read(id->fd, id->sbbuf, off + len);
 374                         if (buf_len < 0) {
 375                                 dbg("read failed (%s)\n", strerror(errno));
 376                                 return NULL;
 377                         }
 378                         dbg("got 0x%zx (%zi) bytes\n", buf_len, buf_len);
 379                         id->sbbuf_len = buf_len;
 380                         if ((size_t)buf_len < off + len) {
 381                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes\n", len, buf_len);
 382                                 return NULL;
 383                         }
 384                 }
 385
 386                 return &(id->sbbuf[off]);
 387         } else {
 388                 if (len > SEEK_BUFFER_SIZE) {
 389                         dbg("seek buffer too small %d\n", SEEK_BUFFER_SIZE);
 390                         return NULL;
 391                 }
 392
 393                 /* get seek buffer */
 394                 if (id->seekbuf == NULL) {
 395                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 396                         if (id->seekbuf == NULL) {
 397                                 dbg("error malloc\n");
 398                                 return NULL;
 399                         }
 400                 }
 401
 402                 /* check if we need to read */
 403                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 404                         info("read seekbuf off:0x%" PRIx64 " len:0x%zx\n", off, len);
 405                         if (lseek(id->fd, off, SEEK_SET) < 0) {
 406                                 dbg("lseek failed (%s)\n", strerror(errno));
 407                                 return NULL;
 408                         }
 409                         buf_len = read(id->fd, id->seekbuf, len);
 410                         if (buf_len < 0) {
 411                                 dbg("read failed (%s)\n", strerror(errno));
 412                                 return NULL;
 413                         }
 414                         dbg("got 0x%zx (%zi) bytes\n", buf_len, buf_len);
 415                         id->seekbuf_off = off;
 416                         id->seekbuf_len = buf_len;
 417                         if ((size_t)buf_len < len) {
 418                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes\n", len, buf_len);
 419                                 return NULL;
 420                         }
 421                 }
 422
 423                 return &(id->seekbuf[off - id->seekbuf_off]);
 424         }
 425 }
 426
 427 void volume_id_free_buffer(struct volume_id *id)
 428 {
 429         if (id->sbbuf != NULL) {
 430                 free(id->sbbuf);
 431                 id->sbbuf = NULL;
 432                 id->sbbuf_len = 0;
 433         }
 434         if (id->seekbuf != NULL) {
 435                 free(id->seekbuf);
 436                 id->seekbuf = NULL;
 437                 id->seekbuf_len = 0;
 438         }
 439 }