extras/volume_id/lib/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 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 "util.h"
  30
  31 void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
  32 {
  33         unsigned int i, j;
  34         uint16_t c;
  35
  36         j = 0;
  37         for (i = 0; i + 2 <= count; i += 2) {
  38                 if (endianess == LE)
  39                         c = (buf[i+1] << 8) | buf[i];
  40                 else
  41                         c = (buf[i] << 8) | buf[i+1];
  42                 if (c == 0) {
  43                         str[j] = '\0';
  44                         break;
  45                 } else if (c < 0x80) {
  46                         if (j+1 >= len)
  47                                 break;
  48                         str[j++] = (uint8_t) c;
  49                 } else if (c < 0x800) {
  50                         if (j+2 >= len)
  51                                 break;
  52                         str[j++] = (uint8_t) (0xc0 | (c >> 6));
  53                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  54                 } else {
  55                         if (j+3 >= len)
  56                                 break;
  57                         str[j++] = (uint8_t) (0xe0 | (c >> 12));
  58                         str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
  59                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  60                 }
  61         }
  62         str[j] = '\0';
  63 }
  64
  65 static char *usage_to_string(enum volume_id_usage usage_id)
  66 {
  67         switch (usage_id) {
  68         case VOLUME_ID_FILESYSTEM:
  69                 return "filesystem";
  70         case VOLUME_ID_OTHER:
  71                 return "other";
  72         case VOLUME_ID_RAID:
  73                 return "raid";
  74         case VOLUME_ID_DISKLABEL:
  75                 return "disklabel";
  76         case VOLUME_ID_CRYPTO:
  77                 return "crypto";
  78         case VOLUME_ID_UNPROBED:
  79                 return "unprobed";
  80         case VOLUME_ID_UNUSED:
  81                 return "unused";
  82         }
  83         return NULL;
  84 }
  85
  86 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
  87 {
  88         id->usage_id = usage_id;
  89         id->usage = usage_to_string(usage_id);
  90 }
  91
  92 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
  93 {
  94         memcpy(id->label_raw, buf, count);
  95         id->label_raw_len = count;
  96 }
  97
  98 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
  99 {
 100         unsigned int i;
 101
 102         memcpy(id->label, buf, count);
 103
 104         /* remove trailing whitespace */
 105         i = strnlen(id->label, count);
 106         while (i--) {
 107                 if (!isspace(id->label[i]))
 108                         break;
 109         }
 110         id->label[i+1] = '\0';
 111 }
 112
 113 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 114 {
 115          volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
 116 }
 117
 118 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
 119 {
 120         unsigned int i;
 121         unsigned int count = 0;
 122
 123         switch(format) {
 124         case UUID_DOS:
 125                 count = 4;
 126                 break;
 127         case UUID_NTFS:
 128         case UUID_HFS:
 129                 count = 8;
 130                 break;
 131         case UUID_DCE:
 132                 count = 16;
 133                 break;
 134         case UUID_DCE_STRING:
 135                 count = 36;
 136                 break;
 137         }
 138         memcpy(id->uuid_raw, buf, count);
 139         id->uuid_raw_len = count;
 140
 141         /* if set, create string in the same format, the native platform uses */
 142         for (i = 0; i < count; i++)
 143                 if (buf[i] != 0)
 144                         goto set;
 145         return;
 146
 147 set:
 148         switch(format) {
 149         case UUID_DOS:
 150                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 151                         buf[3], buf[2], buf[1], buf[0]);
 152                 break;
 153         case UUID_NTFS:
 154                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 155                         buf[7], buf[6], buf[5], buf[4],
 156                         buf[3], buf[2], buf[1], buf[0]);
 157                 break;
 158         case UUID_HFS:
 159                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 160                         buf[0], buf[1], buf[2], buf[3],
 161                         buf[4], buf[5], buf[6], buf[7]);
 162                 break;
 163         case UUID_DCE:
 164                 sprintf(id->uuid,
 165                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 166                         buf[0], buf[1], buf[2], buf[3],
 167                         buf[4], buf[5],
 168                         buf[6], buf[7],
 169                         buf[8], buf[9],
 170                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 171                 break;
 172         case UUID_DCE_STRING:
 173                 memcpy(id->uuid, buf, count);
 174                 id->uuid[count] = '\0';
 175                 break;
 176         }
 177 }
 178
 179 uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 180 {
 181         ssize_t buf_len;
 182
 183         info("get buffer off 0x%llx(%llu), len 0x%zx", (unsigned long long) off, (unsigned long long) off, len);
 184         /* check if requested area fits in superblock buffer */
 185         if (off + len <= SB_BUFFER_SIZE) {
 186                 if (id->sbbuf == NULL) {
 187                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 188                         if (id->sbbuf == NULL) {
 189                                 dbg("error malloc");
 190                                 return NULL;
 191                         }
 192                 }
 193
 194                 /* check if we need to read */
 195                 if ((off + len) > id->sbbuf_len) {
 196                         info("read sbbuf len:0x%llx", (unsigned long long) (off + len));
 197                         if (lseek(id->fd, 0, SEEK_SET) < 0) {
 198                                 dbg("lseek failed (%s)", strerror(errno));
 199                                 return NULL;
 200                         }
 201                         buf_len = read(id->fd, id->sbbuf, off + len);
 202                         if (buf_len < 0) {
 203                                 dbg("read failed (%s)", strerror(errno));
 204                                 return NULL;
 205                         }
 206                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 207                         id->sbbuf_len = buf_len;
 208                         if ((size_t)buf_len < off + len) {
 209                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
 210                                 return NULL;
 211                         }
 212                 }
 213
 214                 return &(id->sbbuf[off]);
 215         } else {
 216                 if (len > SEEK_BUFFER_SIZE) {
 217                         dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 218                         return NULL;
 219                 }
 220
 221                 /* get seek buffer */
 222                 if (id->seekbuf == NULL) {
 223                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 224                         if (id->seekbuf == NULL) {
 225                                 dbg("error malloc");
 226                                 return NULL;
 227                         }
 228                 }
 229
 230                 /* check if we need to read */
 231                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 232                         info("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
 233                         if (lseek(id->fd, off, SEEK_SET) < 0) {
 234                                 dbg("lseek failed (%s)", strerror(errno));
 235                                 return NULL;
 236                         }
 237                         buf_len = read(id->fd, id->seekbuf, len);
 238                         if (buf_len < 0) {
 239                                 dbg("read failed (%s)", strerror(errno));
 240                                 return NULL;
 241                         }
 242                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 243                         id->seekbuf_off = off;
 244                         id->seekbuf_len = buf_len;
 245                         if ((size_t)buf_len < len) {
 246                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
 247                                 return NULL;
 248                         }
 249                 }
 250
 251                 return &(id->seekbuf[off - id->seekbuf_off]);
 252         }
 253 }
 254
 255 void volume_id_free_buffer(struct volume_id *id)
 256 {
 257         if (id->sbbuf != NULL) {
 258                 free(id->sbbuf);
 259                 id->sbbuf = NULL;
 260                 id->sbbuf_len = 0;
 261         }
 262         if (id->seekbuf != NULL) {
 263                 free(id->seekbuf);
 264                 id->seekbuf = NULL;
 265                 id->seekbuf_len = 0;
 266         }
 267 }