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 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 "volume_id.h"
  29 #include "logging.h"
  30 #include "util.h"
  31
  32 void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
  33 {
  34         unsigned int i, j;
  35         uint16_t c;
  36
  37         j = 0;
  38         for (i = 0; i + 2 <= count; i += 2) {
  39                 if (endianess == LE)
  40                         c = (buf[i+1] << 8) | buf[i];
  41                 else
  42                         c = (buf[i] << 8) | buf[i+1];
  43                 if (c == 0) {
  44                         str[j] = '\0';
  45                         break;
  46                 } else if (c < 0x80) {
  47                         if (j+1 >= len)
  48                                 break;
  49                         str[j++] = (uint8_t) c;
  50                 } else if (c < 0x800) {
  51                         if (j+2 >= len)
  52                                 break;
  53                         str[j++] = (uint8_t) (0xc0 | (c >> 6));
  54                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  55                 } else {
  56                         if (j+3 >= len)
  57                                 break;
  58                         str[j++] = (uint8_t) (0xe0 | (c >> 12));
  59                         str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
  60                         str[j++] = (uint8_t) (0x80 | (c & 0x3f));
  61                 }
  62         }
  63         str[j] = '\0';
  64 }
  65
  66 static char *usage_to_string(enum volume_id_usage usage_id)
  67 {
  68         switch (usage_id) {
  69         case VOLUME_ID_FILESYSTEM:
  70                 return "filesystem";
  71         case VOLUME_ID_PARTITIONTABLE:
  72                 return "partitiontable";
  73         case VOLUME_ID_OTHER:
  74                 return "other";
  75         case VOLUME_ID_RAID:
  76                 return "raid";
  77         case VOLUME_ID_DISKLABEL:
  78                 return "disklabel";
  79         case VOLUME_ID_CRYPTO:
  80                 return "crypto";
  81         case VOLUME_ID_UNPROBED:
  82                 return "unprobed";
  83         case VOLUME_ID_UNUSED:
  84                 return "unused";
  85         }
  86         return NULL;
  87 }
  88
  89 void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
  90 {
  91         part->usage_id = usage_id;
  92         part->usage = usage_to_string(usage_id);
  93 }
  94
  95 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
  96 {
  97         id->usage_id = usage_id;
  98         id->usage = usage_to_string(usage_id);
  99 }
 100
 101 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
 102 {
 103         memcpy(id->label_raw, buf, count);
 104         id->label_raw_len = count;
 105 }
 106
 107 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 108 {
 109         unsigned int i;
 110
 111         memcpy(id->label, buf, count);
 112
 113         /* remove trailing whitespace */
 114         i = strnlen(id->label, count);
 115         while (i--) {
 116                 if (!isspace(id->label[i]))
 117                         break;
 118         }
 119         id->label[i+1] = '\0';
 120 }
 121
 122 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 123 {
 124          volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
 125 }
 126
 127 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
 128 {
 129         unsigned int i;
 130         unsigned int count = 0;
 131
 132         switch(format) {
 133         case UUID_DOS:
 134                 count = 4;
 135                 break;
 136         case UUID_NTFS:
 137         case UUID_HFS:
 138                 count = 8;
 139                 break;
 140         case UUID_DCE:
 141                 count = 16;
 142                 break;
 143         case UUID_DCE_STRING:
 144                 count = 36;
 145                 break;
 146         }
 147         memcpy(id->uuid_raw, buf, count);
 148         id->uuid_raw_len = count;
 149
 150         /* if set, create string in the same format, the native platform uses */
 151         for (i = 0; i < count; i++)
 152                 if (buf[i] != 0)
 153                         goto set;
 154         return;
 155
 156 set:
 157         switch(format) {
 158         case UUID_DOS:
 159                 sprintf(id->uuid, "%02X%02X-%02X%02X",
 160                         buf[3], buf[2], buf[1], buf[0]);
 161                 break;
 162         case UUID_NTFS:
 163                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 164                         buf[7], buf[6], buf[5], buf[4],
 165                         buf[3], buf[2], buf[1], buf[0]);
 166                 break;
 167         case UUID_HFS:
 168                 sprintf(id->uuid,"%02X%02X%02X%02X%02X%02X%02X%02X",
 169                         buf[0], buf[1], buf[2], buf[3],
 170                         buf[4], buf[5], buf[6], buf[7]);
 171                 break;
 172         case UUID_DCE:
 173                 sprintf(id->uuid,
 174                         "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 175                         buf[0], buf[1], buf[2], buf[3],
 176                         buf[4], buf[5],
 177                         buf[6], buf[7],
 178                         buf[8], buf[9],
 179                         buf[10], buf[11], buf[12], buf[13], buf[14],buf[15]);
 180                 break;
 181         case UUID_DCE_STRING:
 182                 memcpy(id->uuid, buf, count);
 183                 id->uuid[count] = '\0';
 184                 break;
 185         }
 186 }
 187
 188 uint8_t *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 189 {
 190         ssize_t buf_len;
 191
 192         dbg("get buffer off 0x%llx(%llu), len 0x%zx", (unsigned long long) off, (unsigned long long) off, len);
 193         /* check if requested area fits in superblock buffer */
 194         if (off + len <= SB_BUFFER_SIZE) {
 195                 if (id->sbbuf == NULL) {
 196                         id->sbbuf = malloc(SB_BUFFER_SIZE);
 197                         if (id->sbbuf == NULL) {
 198                                 dbg("error malloc");
 199                                 return NULL;
 200                         }
 201                 }
 202
 203                 /* check if we need to read */
 204                 if ((off + len) > id->sbbuf_len) {
 205                         dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
 206                         if (lseek(id->fd, 0, SEEK_SET) < 0) {
 207                                 dbg("lseek failed (%s)", strerror(errno));
 208                                 return NULL;
 209                         }
 210                         buf_len = read(id->fd, id->sbbuf, off + len);
 211                         if (buf_len < 0) {
 212                                 dbg("read failed (%s)", strerror(errno));
 213                                 return NULL;
 214                         }
 215                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 216                         id->sbbuf_len = buf_len;
 217                         if ((size_t)buf_len < off + len) {
 218                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
 219                                 return NULL;
 220                         }
 221                 }
 222
 223                 return &(id->sbbuf[off]);
 224         } else {
 225                 if (len > SEEK_BUFFER_SIZE) {
 226                         dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 227                         return NULL;
 228                 }
 229
 230                 /* get seek buffer */
 231                 if (id->seekbuf == NULL) {
 232                         id->seekbuf = malloc(SEEK_BUFFER_SIZE);
 233                         if (id->seekbuf == NULL) {
 234                                 dbg("error malloc");
 235                                 return NULL;
 236                         }
 237                 }
 238
 239                 /* check if we need to read */
 240                 if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
 241                         dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
 242                         if (lseek(id->fd, off, SEEK_SET) < 0) {
 243                                 dbg("lseek failed (%s)", strerror(errno));
 244                                 return NULL;
 245                         }
 246                         buf_len = read(id->fd, id->seekbuf, len);
 247                         if (buf_len < 0) {
 248                                 dbg("read failed (%s)", strerror(errno));
 249                                 return NULL;
 250                         }
 251                         dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
 252                         id->seekbuf_off = off;
 253                         id->seekbuf_len = buf_len;
 254                         if ((size_t)buf_len < len) {
 255                                 dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
 256                                 return NULL;
 257                         }
 258                 }
 259
 260                 return &(id->seekbuf[off - id->seekbuf_off]);
 261         }
 262 }
 263
 264 void volume_id_free_buffer(struct volume_id *id)
 265 {
 266         if (id->sbbuf != NULL) {
 267                 free(id->sbbuf);
 268                 id->sbbuf = NULL;
 269                 id->sbbuf_len = 0;
 270         }
 271         if (id->seekbuf != NULL) {
 272                 free(id->seekbuf);
 273                 id->seekbuf = NULL;
 274                 id->seekbuf_len = 0;
 275         }
 276 }