libblkid-tiny/libblkid-tiny.c

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