libblkid-tiny/libblkid-tiny.c

   1 #include <stdio.h>
   2 #include <sys/utsname.h>
   3
   4 #include "libblkid-tiny.h"
   5 #include "superblocks.h"
   6 #include "linux_version.h"
   7
   8 #if 0
   9 #define DEBUG(fmt, ...) printf(fmt, __VA_ARGS__)
  10 #else
  11 #define DEBUG(fmt, ...)
  12 #endif
  13
  14 int blkid_debug_mask = 0;
  15
  16 static unsigned char *probe_buffer;
  17 static unsigned int probe_buffer_size = 0;
  18
  19 int get_linux_version (void)
  20 {
  21         static int kver = -1;
  22         struct utsname uts;
  23         int major = 0;
  24         int minor = 0;
  25         int teeny = 0;
  26         int n;
  27
  28         if (kver != -1)
  29                 return kver;
  30         if (uname (&uts))
  31                 return kver = 0;
  32
  33         n = sscanf(uts.release, "%d.%d.%d", &major, &minor, &teeny);
  34         if (n < 1 || n > 3)
  35                 return kver = 0;
  36
  37         return kver = KERNEL_VERSION(major, minor, teeny);
  38 }
  39
  40 int blkid_probe_is_tiny(blkid_probe pr)
  41 {
  42         /* never true ? */
  43         return 0;
  44 }
  45
  46 int blkid_probe_set_value(blkid_probe pr, const char *name,
  47                 unsigned char *data, size_t len)
  48 {
  49         /* empty stub */
  50         return 0;
  51 }
  52
  53 int blkid_probe_set_version(blkid_probe pr, const char *version)
  54 {
  55         int len = strlen(version);
  56         if (len > (sizeof(pr->version) - 1)) {
  57                 fprintf(stderr, "version buffer too small %d\n", len);
  58                 return -1;
  59         }
  60
  61         strncpy(pr->version, version, sizeof(pr->version));
  62
  63         return 0;
  64 }
  65
  66 int blkid_probe_sprintf_version(blkid_probe pr, const char *fmt, ...)
  67 {
  68         va_list ap;
  69         int n;
  70
  71         va_start(ap, fmt);
  72         n = vsnprintf(pr->version, sizeof(pr->version), fmt, ap);
  73         va_end(ap);
  74
  75         if (n >= sizeof(pr->version))
  76                 fprintf(stderr, "version buffer too small %d\n", n);
  77
  78         return 0;
  79 }
  80
  81 unsigned char *blkid_probe_get_buffer(blkid_probe pr,
  82                                 blkid_loff_t off, blkid_loff_t len)
  83 {
  84         int ret;
  85         unsigned char *buf;
  86
  87         if (len > probe_buffer_size) {
  88                 buf = realloc(probe_buffer, len);
  89
  90                 if (!buf) {
  91                         fprintf(stderr, "failed to allocate %d byte buffer\n",
  92                                 (int)len);
  93
  94                         return NULL;
  95                 }
  96
  97                 probe_buffer = buf;
  98                 probe_buffer_size = len;
  99         }
 100
 101         memset(probe_buffer, 0, probe_buffer_size);
 102
 103         lseek(pr->fd, off, SEEK_SET);
 104         ret = read(pr->fd, probe_buffer, len);
 105
 106         if (ret != len)
 107                 fprintf(stderr, "faile to read blkid\n");
 108
 109         return probe_buffer;
 110 }
 111
 112 int blkid_probe_set_label(blkid_probe pr, unsigned char *label, size_t len)
 113 {
 114         if (len > (sizeof(pr->label) - 1)) {
 115                 fprintf(stderr, "label buffer too small %d > %d\n",
 116                         (int) len, (int) sizeof(pr->label) - 1);
 117                 return -1;
 118         }
 119         memcpy(pr->label, label, len + 1);
 120
 121         return 0;
 122 }
 123
 124 int blkid_probe_set_uuid_as(blkid_probe pr, unsigned char *uuid, const char *name)
 125 {
 126         short unsigned int*u = (short unsigned int*) uuid;
 127
 128         if (u[0] && (!name || !strcmp(name, "UUID"))) {
 129                 sprintf(pr->uuid,
 130                         "%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
 131                         be16_to_cpu(u[0]), be16_to_cpu(u[1]), be16_to_cpu(u[2]), be16_to_cpu(u[3]),
 132                         be16_to_cpu(u[4]), be16_to_cpu(u[5]), be16_to_cpu(u[6]), be16_to_cpu(u[7]));
 133         }
 134
 135         return 0;
 136 }
 137
 138 int blkid_probe_set_uuid(blkid_probe pr, unsigned char *uuid)
 139 {
 140         return blkid_probe_set_uuid_as(pr, uuid, NULL);
 141 }
 142
 143 int blkid_probe_sprintf_uuid(blkid_probe pr, unsigned char *uuid,
 144                              size_t len, const char *fmt, ...)
 145 {
 146         va_list ap;
 147
 148         va_start(ap, fmt);
 149         vsnprintf(pr->uuid, sizeof(pr->uuid), fmt, ap);
 150         va_end(ap);
 151
 152         return 0;
 153 }
 154
 155 static const struct blkid_idinfo *idinfos[] =
 156 {
 157         &vfat_idinfo,
 158         &swsuspend_idinfo,
 159         &swap_idinfo,
 160         &ext4dev_idinfo,
 161         &ext4_idinfo,
 162         &ext3_idinfo,
 163         &ext2_idinfo,
 164         &jbd_idinfo,
 165         &ntfs_idinfo,
 166         &squashfs_idinfo,
 167         &ubi_idinfo,
 168         &ubifs_idinfo,
 169         &jffs2_idinfo,
 170         &hfsplus_idinfo,
 171         &hfs_idinfo,
 172         &btrfs_idinfo,
 173         &f2fs_idinfo,
 174 };
 175
 176 int probe_block(char *block, struct blkid_struct_probe *pr)
 177 {
 178         struct stat s;
 179         int i;
 180
 181         if (stat(block, &s) || (!S_ISBLK(s.st_mode) && !S_ISREG(s.st_mode) && !strncmp(block, "ubi", 3)))
 182                 return -1;
 183
 184         pr->err = -1;
 185         pr->fd = open(block, O_RDONLY);
 186         if (!pr->fd)
 187                 return -1;
 188
 189         for (i = 0; i < ARRAY_SIZE(idinfos); i++) {
 190                 /* loop over all magic handlers */
 191                 const struct blkid_idmag *mag;
 192
 193                 /* loop over all probe handlers */
 194                 DEBUG("scanning %s\n", idinfos[i]->name);
 195
 196                 mag = &idinfos[i]->magics[0];
 197
 198                 while (mag->magic) {
 199                         int off = (mag->kboff * 1024) + mag->sboff;
 200                         char magic[32] = { 0 };
 201
 202                         lseek(pr->fd, off, SEEK_SET);
 203                         if (read(pr->fd, magic, mag->len) < 0)
 204                                 return -1;
 205
 206                         DEBUG("magic: %s %s %d\n", mag->magic, magic, mag->len);
 207                         if (!memcmp(mag->magic, magic, mag->len))
 208                                 break;
 209                         mag++;
 210                 }
 211
 212                 if (mag && mag->magic) {
 213                         DEBUG("probing %s\n", idinfos[i]->name);
 214                         pr->err = idinfos[i]->probefunc(pr, mag);
 215                         pr->id = idinfos[i];
 216                         strcpy(pr->dev, block);
 217                         if (!pr->err)
 218                                 break;
 219                 }
 220         }
 221
 222         close(pr->fd);
 223
 224         return 0;
 225 }