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 it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  */
  10
  11 #ifndef _GNU_SOURCE
  12 #define _GNU_SOURCE 1
  13 #endif
  14
  15 #ifdef HAVE_CONFIG_H
  16 #  include <config.h>
  17 #endif
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25 #include <fcntl.h>
  26 #include <sys/stat.h>
  27
  28 #include "libvolume_id.h"
  29 #include "libvolume_id-private.h"
  30 #include "util.h"
  31
  32 /* count of characters used to encode one unicode char */
  33 static int utf8_encoded_expected_len(const char *str)
  34 {
  35         unsigned char c = (unsigned char)str[0];
  36
  37         if (c < 0x80)
  38                 return 1;
  39         if ((c & 0xe0) == 0xc0)
  40                 return 2;
  41         if ((c & 0xf0) == 0xe0)
  42                 return 3;
  43         if ((c & 0xf8) == 0xf0)
  44                 return 4;
  45         if ((c & 0xfc) == 0xf8)
  46                 return 5;
  47         if ((c & 0xfe) == 0xfc)
  48                 return 6;
  49         return 0;
  50 }
  51
  52 /* decode one unicode char */
  53 static int utf8_encoded_to_unichar(const char *str)
  54 {
  55         int unichar;
  56         int len;
  57         int i;
  58
  59         len = utf8_encoded_expected_len(str);
  60         switch (len) {
  61         case 1:
  62                 return (int)str[0];
  63         case 2:
  64                 unichar = str[0] & 0x1f;
  65                 break;
  66         case 3:
  67                 unichar = (int)str[0] & 0x0f;
  68                 break;
  69         case 4:
  70                 unichar = (int)str[0] & 0x07;
  71                 break;
  72         case 5:
  73                 unichar = (int)str[0] & 0x03;
  74                 break;
  75         case 6:
  76                 unichar = (int)str[0] & 0x01;
  77                 break;
  78         default:
  79                 return -1;
  80         }
  81
  82         for (i = 1; i < len; i++) {
  83                 if (((int)str[i] & 0xc0) != 0x80)
  84                         return -1;
  85                 unichar <<= 6;
  86                 unichar |= (int)str[i] & 0x3f;
  87         }
  88
  89         return unichar;
  90 }
  91
  92 /* expected size used to encode one unicode char */
  93 static int utf8_unichar_to_encoded_len(int unichar)
  94 {
  95         if (unichar < 0x80)
  96                 return 1;
  97         if (unichar < 0x800)
  98                 return 2;
  99         if (unichar < 0x10000)
 100                 return 3;
 101         if (unichar < 0x200000)
 102                 return 4;
 103         if (unichar < 0x4000000)
 104                 return 5;
 105         return 6;
 106 }
 107
 108 /* check if unicode char has a valid numeric range */
 109 static int utf8_unichar_valid_range(int unichar)
 110 {
 111         if (unichar > 0x10ffff)
 112                 return 0;
 113         if ((unichar & 0xfffff800) == 0xd800)
 114                 return 0;
 115         if ((unichar > 0xfdcf) && (unichar < 0xfdf0))
 116                 return 0;
 117         if ((unichar & 0xffff) == 0xffff)
 118                 return 0;
 119         return 1;
 120 }
 121
 122 /* validate one encoded unicode char and return its length */
 123 int volume_id_utf8_encoded_valid_unichar(const char *str)
 124 {
 125         int len;
 126         int unichar;
 127         int i;
 128
 129         len = utf8_encoded_expected_len(str);
 130         if (len == 0)
 131                 return -1;
 132
 133         /* ascii is valid */
 134         if (len == 1)
 135                 return 1;
 136
 137         /* check if expected encoded chars are available */
 138         for (i = 0; i < len; i++)
 139                 if ((str[i] & 0x80) != 0x80)
 140                         return -1;
 141
 142         unichar = utf8_encoded_to_unichar(str);
 143
 144         /* check if encoded length matches encoded value */
 145         if (utf8_unichar_to_encoded_len(unichar) != len)
 146                 return -1;
 147
 148         /* check if value has valid range */
 149         if (!utf8_unichar_valid_range(unichar))
 150                 return -1;
 151
 152         return len;
 153 }
 154
 155 size_t volume_id_set_unicode16(uint8_t *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
 156 {
 157         size_t i, j;
 158         uint16_t c;
 159
 160         j = 0;
 161         for (i = 0; i + 2 <= count; i += 2) {
 162                 if (endianess == LE)
 163                         c = (buf[i+1] << 8) | buf[i];
 164                 else
 165                         c = (buf[i] << 8) | buf[i+1];
 166                 if (c == 0) {
 167                         str[j] = '\0';
 168                         break;
 169                 } else if (c < 0x80) {
 170                         if (j+1 >= len)
 171                                 break;
 172                         str[j++] = (uint8_t) c;
 173                 } else if (c < 0x800) {
 174                         if (j+2 >= len)
 175                                 break;
 176                         str[j++] = (uint8_t) (0xc0 | (c >> 6));
 177                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 178                 } else {
 179                         if (j+3 >= len)
 180                                 break;
 181                         str[j++] = (uint8_t) (0xe0 | (c >> 12));
 182                         str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
 183                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 184                 }
 185         }
 186         str[j] = '\0';
 187         return j;
 188 }
 189
 190 static char *usage_to_string(enum volume_id_usage usage_id)
 191 {
 192         switch (usage_id) {
 193         case VOLUME_ID_FILESYSTEM:
 194                 return "filesystem";
 195         case VOLUME_ID_OTHER:
 196                 return "other";
 197         case VOLUME_ID_RAID:
 198                 return "raid";
 199         case VOLUME_ID_DISKLABEL:
 200                 return "disklabel";
 201         case VOLUME_ID_CRYPTO:
 202                 return "crypto";
 203         case VOLUME_ID_UNPROBED:
 204                 return "unprobed";
 205         case VOLUME_ID_UNUSED:
 206                 return "unused";
 207         }
 208         return NULL;
 209 }
 210
 211 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
 212 {
 213         id->usage_id = usage_id;
 214         id->usage = usage_to_string(usage_id);
 215 }
 216
 217 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
 218 {
 219         if (count > sizeof(id->label_raw))
 220                 count = sizeof(id->label_raw);
 221
 222         memcpy(id->label_raw, buf, count);
 223         id->label_raw_len = count;
 224 }
 225
 226 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 227 {
 228         size_t i;
 229
 230         if (count >= sizeof(id->label))
 231                 count = sizeof(id->label)-1;
 232
 233         memcpy(id->label, buf, count);
 234         id->label[count] = '\0';
 235
 236         /* remove trailing whitespace */
 237         i = strnlen(id->label, count);
 238         while (i--) {
 239                 if (!isspace(id->label[i]))
 240                         break;
 241         }
 242         id->label[i+1] = '\0';
 243 }
 244
 245 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 246 {
 247         if (count >= sizeof(id->label))
 248                 count = sizeof(id->label)-1;
 249
 250          volume_id_set_unicode16((uint8_t *)id->label, sizeof(id->label), buf, endianess, count);
 251 }
 252
 253 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, size_t len, enum uuid_format format)
 254 {
 255         unsigned int i;
 256         unsigned int count = 0;
 257
 258         if (len > sizeof(id->uuid_raw))
 259                 len = sizeof(id->uuid_raw);
 260
 261         switch(format) {
 262         case UUID_STRING:
 263                 count = len;
 264                 break;
 265         case UUID_HEX_STRING:
 266                 count = len;
 267                 break;
 268         case UUID_DOS:
 269                 count = 4;
 270                 break;
 271         case UUID_64BIT_LE:
 272         case UUID_64BIT_BE:
 273                 count = 8;
 274                 break;
 275         case UUID_DCE:
 276                 count = 16;
 277                 break;
 278         case UUID_MD:
 279                 count = 35;
 280                 break;
 281         case UUID_LVM:
 282                 count = 32;
 283                 break;
 284         }
 285         memcpy(id->uuid_raw, buf, count);
 286         id->uuid_raw_len = count;
 287
 288         /* if set, create string in the same format, the native platform uses */
 289         for (i = 0; i < count; i++)
 290                 if (buf[i] != 0)
 291                         goto set;
 292         return;
 293
 294 set:
 295         switch(format) {
 296         case UUID_DOS:
 297                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 298                         buf[3], buf[2], buf[1], buf[0]);
 299                 break;
 300         case UUID_64BIT_LE:
 301                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 302                         buf[7], buf[6], buf[5], buf[4],
 303                         buf[3], buf[2], buf[1], buf[0]);
 304                 break;
 305         case UUID_64BIT_BE:
 306                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 307                         buf[0], buf[1], buf[2], buf[3],
 308                         buf[4], buf[5], buf[6], buf[7]);
 309                 break;
 310         case UUID_DCE:
 311                 sprintf(id->uuid,
 312                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 313                         buf[0], buf[1], buf[2], buf[3],
 314                         buf[4], buf[5],
 315                         buf[6], buf[7],
 316                         buf[8], buf[9],
 317                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 318                 break;
 319         case UUID_HEX_STRING:
 320                 /* translate A..F to a..f */
 321                 memcpy(id->uuid, buf, count);
 322                 for (i = 0; i < count; i++)
 323                         if (id->uuid[i] >= 'A' && id->uuid[i] <= 'F')
 324                                 id->uuid[i] = (id->uuid[i] - 'A') + 'a';
 325                 id->uuid[count] = '\0';
 326                 break;
 327         case UUID_STRING:
 328                 memcpy(id->uuid, buf, count);
 329                 id->uuid[count] = '\0';
 330                 break;
 331         case UUID_MD:
 332                 sprintf(id->uuid,
 333                         "%02x%02x%02x%02x:%02x%02x%02x%02x:%02x%02x%02x%02x:%02x%02x%02x%02x",
 334                         buf[0], buf[1], buf[2], buf[3],
 335                         buf[4], buf[5], buf[6], buf[7],
 336                         buf[8], buf[9], buf[10], buf[11],
 337                         buf[12], buf[13], buf[14],buf[15]);
 338                 break;
 339         case UUID_LVM:
 340                 sprintf(id->uuid,
 341                         "%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",
 342                         buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
 343                         buf[6], buf[7], buf[8], buf[9],
 344                         buf[10], buf[11], buf[12], buf[13],
 345                         buf[14], buf[15], buf[16], buf[17],
 346                         buf[18], buf[19], buf[20], buf[21],
 347                         buf[22], buf[23], buf[24], buf[25],
 348                         buf[26], buf[27], buf[28], buf[29], buf[30], buf[31]);
 349                 break;
 350         }
 351 }
 352
 353 uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 354 {
 355         ssize_t buf_len;
 356
 357         info("get buffer off 0x%llx(%llu), len 0x%zx\n", (unsigned long long) off, (unsigned long long) off, len);
 358         /* check if requested area fits in superblock buffer */
 359         if (off + len <= SB_BUFFER_SIZE) {
 360                 if (id->sbbuf == NULL) {
 361                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 362                         if (id->sbbuf == NULL) {
 363                                 dbg("error malloc\n");
 364                                 return NULL;
 365                         }
 366                 }
 367
 368                 /* check if we need to read */
 369                 if ((off + len) > id->sbbuf_len) {
 370                         info("read sbbuf len:0x%llx\n", (unsigned long long) (off + len));
 371                         if (lseek(id->fd, 0, SEEK_SET) < 0) {
 372                                 dbg("lseek failed (%s)\n", strerror(errno));
 373                                 return NULL;
 374                         }
 375                         buf_len = read(id->fd, id->sbbuf, off + len);
 376                         if (buf_len < 0) {
 377                                 dbg("read failed (%s)\n", strerror(errno));
 378                                 return NULL;
 379                         }
 380                         dbg("got 0x%zx (%zi) bytes\n", buf_len, buf_len);
 381                         id->sbbuf_len = buf_len;
 382                         if ((size_t)buf_len < off + len) {
 383                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes\n", len, buf_len);
 384                                 return NULL;
 385                         }
 386                 }
 387
 388                 return &(id->sbbuf[off]);
 389         } else {
 390                 if (len > SEEK_BUFFER_SIZE) {
 391                         dbg("seek buffer too small %d\n", SEEK_BUFFER_SIZE);
 392                         return NULL;
 393                 }
 394
 395                 /* get seek buffer */
 396                 if (id->seekbuf == NULL) {
 397                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 398                         if (id->seekbuf == NULL) {
 399                                 dbg("error malloc\n");
 400                                 return NULL;
 401                         }
 402                 }
 403
 404                 /* check if we need to read */
 405                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 406                         info("read seekbuf off:0x%llx len:0x%zx\n", (unsigned long long) off, len);
 407                         if (lseek(id->fd, off, SEEK_SET) < 0) {
 408                                 dbg("lseek failed (%s)\n", strerror(errno));
 409                                 return NULL;
 410                         }
 411                         buf_len = read(id->fd, id->seekbuf, len);
 412                         if (buf_len < 0) {
 413                                 dbg("read failed (%s)\n", strerror(errno));
 414                                 return NULL;
 415                         }
 416                         dbg("got 0x%zx (%zi) bytes\n", buf_len, buf_len);
 417                         id->seekbuf_off = off;
 418                         id->seekbuf_len = buf_len;
 419                         if ((size_t)buf_len < len) {
 420                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes\n", len, buf_len);
 421                                 return NULL;
 422                         }
 423                 }
 424
 425                 return &(id->seekbuf[off - id->seekbuf_off]);
 426         }
 427 }
 428
 429 void volume_id_free_buffer(struct volume_id *id)
 430 {
 431         if (id->sbbuf != NULL) {
 432                 free(id->sbbuf);
 433                 id->sbbuf = NULL;
 434                 id->sbbuf_len = 0;
 435         }
 436         if (id->seekbuf != NULL) {
 437                 free(id->seekbuf);
 438                 id->seekbuf = NULL;
 439                 id->seekbuf_len = 0;
 440         }
 441 }