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])
 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         if (name)
 134                 strncpy(pr->name, name, sizeof(pr->name));
 135
 136         return 0;
 137 }
 138
 139 int blkid_probe_set_uuid(blkid_probe pr, unsigned char *uuid)
 140 {
 141         return blkid_probe_set_uuid_as(pr, uuid, NULL);
 142 }
 143
 144 int blkid_probe_sprintf_uuid(blkid_probe pr, unsigned char *uuid,
 145                              size_t len, const char *fmt, ...)
 146 {
 147         va_list ap;
 148
 149         va_start(ap, fmt);
 150         vsnprintf(pr->uuid, sizeof(pr->uuid), fmt, ap);
 151         va_end(ap);
 152
 153         return 0;
 154 }
 155
 156 static const struct blkid_idinfo *idinfos[] =
 157 {
 158         &vfat_idinfo,
 159         &swsuspend_idinfo,
 160         &swap_idinfo,
 161         &ext4dev_idinfo,
 162         &ext4_idinfo,
 163         &ext3_idinfo,
 164         &ext2_idinfo,
 165         &jbd_idinfo,
 166         &squashfs_idinfo,
 167         &ubifs_idinfo,
 168         &jffs2_idinfo,
 169         &hfsplus_idinfo,
 170         &hfs_idinfo,
 171         &btrfs_idinfo,
 172 };
 173
 174 int probe_block(char *block, struct blkid_struct_probe *pr)
 175 {
 176         struct stat s;
 177         int i;
 178
 179         if (stat(block, &s) || (!S_ISBLK(s.st_mode) && !S_ISREG(s.st_mode) && !strncmp(block, "ubi", 3)))
 180                 return -1;
 181
 182         pr->err = -1;
 183         pr->fd = open(block, O_RDONLY);
 184         if (!pr->fd)
 185                 return -1;
 186
 187         for (i = 0; i < ARRAY_SIZE(idinfos); i++) {
 188                 /* loop over all magic handlers */
 189                 const struct blkid_idmag *mag;
 190
 191                 /* loop over all probe handlers */
 192                 DEBUG("scanning %s\n", idinfos[i]->name);
 193
 194                 mag = &idinfos[i]->magics[0];
 195
 196                 while (mag->magic) {
 197                         int off = (mag->kboff * 1024) + mag->sboff;
 198                         char magic[32] = { 0 };
 199
 200                         lseek(pr->fd, off, SEEK_SET);
 201                         if (read(pr->fd, magic, mag->len) < 0)
 202                                 return -1;
 203
 204                         DEBUG("magic: %s %s %d\n", mag->magic, magic, mag->len);
 205                         if (!memcmp(mag->magic, magic, mag->len))
 206                                 break;
 207                         mag++;
 208                 }
 209
 210                 if (mag && mag->magic) {
 211                         DEBUG("probing %s\n", idinfos[i]->name);
 212                         pr->err = idinfos[i]->probefunc(pr, mag);
 213                         pr->id = idinfos[i];
 214                         strcpy(pr->dev, block);
 215                         if (!pr->err)
 216                                 break;
 217                 }
 218         }
 219
 220         close(pr->fd);
 221
 222         return 0;
 223 }