lib/libstand/uuid_from_string.c

   1 /*-
   2  * Copyright (c) 2015 M. Warner Losh
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: head/lib/libstand/uuid_from_string.c 300264 2016-05-20 05:33:26Z imp $
  27  */
  28
  29 /*
  30  * Note: some comments taken from lib/libc/uuid/uuid_from_string.c
  31  * Copyright (c) 2002 Marcel Moolenaar
  32  * Copyright (c) 2002 Hiten Mahesh Pandya
  33  */
  34
  35
  36 #include <stand.h>
  37 #include <uuid.h>
  38
  39 static int
  40 hex2int(int ch)
  41 {
  42         if (ch >= '0' && ch <= '9')
  43                 return ch - '0';
  44         if (ch >= 'a' && ch <= 'f')
  45                 return 10 + ch - 'a';
  46         if (ch >= 'A' && ch <= 'F')
  47                 return 10 + ch - 'A';
  48         return 16;
  49 }
  50
  51 static uint32_t
  52 fromhex(const char *s, int len, int *ok)
  53 {
  54         uint32_t v;
  55         int i, h;
  56
  57         if (!*ok)
  58                 return 0;
  59         v = 0;
  60         for (i = 0; i < len; i++) {
  61                 h = hex2int(s[i]);
  62                 if (h == 16) {
  63                         *ok = 0;
  64                         return v;
  65                 }
  66                 v = (v << 4) | h;
  67         }
  68         return v;
  69 }
  70
  71 /*
  72  * uuid_from_string() - convert a string representation of an UUID into
  73  *                      a binary representation.
  74  * See also:
  75  *      http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
  76  *
  77  * NOTE: The sequence field is in big-endian, while the time fields are in
  78  *       native byte order.
  79  *
  80  * 01234567-89ab-cdef-0123-456789abcdef
  81  * 000000000011111111112222222222333333
  82  * 012345678901234567890123456789012345
  83  *         -    -    -    -
  84  * hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
  85  *
  86  */
  87 void
  88 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
  89 {
  90         int ok = 1;
  91         int n;
  92
  93         if (s == NULL || *s == '\0') {
  94                 uuid_create_nil(u, status);
  95                 return;
  96         }
  97
  98         if (status != NULL)
  99                 *status = uuid_s_invalid_string_uuid;
 100         if (strlen(s) != 36)
 101                 return;
 102         /* Only support new format, check for all the right dashes */
 103         if (s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-')
 104                 return;
 105         /* native byte order */
 106         u->time_low                  = fromhex(s     , 8, &ok);
 107         u->time_mid                  = fromhex(s +  9, 4, &ok);
 108         u->time_hi_and_version       = fromhex(s + 14, 4, &ok);
 109         /* Big endian, but presented as a whole number so decode as such */
 110         u->clock_seq_hi_and_reserved = fromhex(s + 19, 2, &ok);
 111         u->clock_seq_low             = fromhex(s + 21, 2, &ok);
 112         u->node[0]                   = fromhex(s + 24, 2, &ok);
 113         u->node[1]                   = fromhex(s + 26, 2, &ok);
 114         u->node[2]                   = fromhex(s + 28, 2, &ok);
 115         u->node[3]                   = fromhex(s + 30, 2, &ok);
 116         u->node[4]                   = fromhex(s + 32, 2, &ok);
 117         u->node[5]                   = fromhex(s + 34, 2, &ok);
 118         if (!ok)
 119                 return;
 120
 121         /* We have a successful scan. Check semantics... */
 122         n = u->clock_seq_hi_and_reserved;
 123         if ((n & 0x80) != 0x00 &&                       /* variant 0? */
 124             (n & 0xc0) != 0x80 &&                       /* variant 1? */
 125             (n & 0xe0) != 0xc0) {                       /* variant 2? */
 126                 if (status != NULL)
 127                         *status = uuid_s_bad_version;
 128         } else {
 129                 if (status != NULL)
 130                         *status = uuid_s_ok;
 131         }
 132 }