lib/uuid.c

   1 /*
   2  * Copyright 2011 Calxeda, Inc.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <linux/ctype.h>
   8 #include "common.h"
   9
  10 /*
  11  * This is what a UUID string looks like.
  12  *
  13  * x is a hexadecimal character. fields are separated by '-'s. When converting
  14  * to a binary UUID, le means the field should be converted to little endian,
  15  * and be means it should be converted to big endian.
  16  *
  17  * 0        9    14   19   24
  18  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
  19  *    le     le   le   be       be
  20  */
  21
  22 int uuid_str_valid(const char *uuid)
  23 {
  24         int i, valid;
  25
  26         if (uuid == NULL)
  27                 return 0;
  28
  29         for (i = 0, valid = 1; uuid[i] && valid; i++) {
  30                 switch (i) {
  31                 case 8: case 13: case 18: case 23:
  32                         valid = (uuid[i] == '-');
  33                         break;
  34                 default:
  35                         valid = isxdigit(uuid[i]);
  36                         break;
  37                 }
  38         }
  39
  40         if (i != 36 || !valid)
  41                 return 0;
  42
  43         return 1;
  44 }
  45
  46 void uuid_str_to_bin(const char *uuid, unsigned char *out)
  47 {
  48         uint16_t tmp16;
  49         uint32_t tmp32;
  50         uint64_t tmp64;
  51
  52         if (!uuid || !out)
  53                 return;
  54
  55         tmp32 = cpu_to_le32(simple_strtoul(uuid, NULL, 16));
  56         memcpy(out, &tmp32, 4);
  57
  58         tmp16 = cpu_to_le16(simple_strtoul(uuid + 9, NULL, 16));
  59         memcpy(out + 4, &tmp16, 2);
  60
  61         tmp16 = cpu_to_le16(simple_strtoul(uuid + 14, NULL, 16));
  62         memcpy(out + 6, &tmp16, 2);
  63
  64         tmp16 = cpu_to_be16(simple_strtoul(uuid + 19, NULL, 16));
  65         memcpy(out + 8, &tmp16, 2);
  66
  67         tmp64 = cpu_to_be64(simple_strtoull(uuid + 24, NULL, 16));
  68         memcpy(out + 10, (char *)&tmp64 + 2, 6);
  69 }