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