lib/libc/uuid/uuid_from_string.c

   1 /*-
   2  * Copyright (c) 2002 Marcel Moolenaar
   3  * Copyright (c) 2002 Hiten Mahesh Pandya
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * $FreeBSD: src/lib/libc/uuid/uuid_from_string.c,v 1.2 2003/08/08 19:18:43 marcel Exp $
  28  * $DragonFly: src/lib/libc/uuid/uuid_from_string.c,v 1.1 2007/06/16 19:57:14 dillon Exp $
  29  */
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <uuid.h>
  34
  35 /*
  36  * uuid_from_string() - convert a string representation of an UUID into
  37  *                      a binary representation.
  38  * See also:
  39  *      http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
  40  *
  41  * NOTE: The sequence field is in big-endian, while the time fields are in
  42  *       native byte order.
  43  */
  44 void
  45 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
  46 {
  47         int n;
  48
  49         /* Short-circuit 2 special cases: NULL pointer and empty string. */
  50         if (s == NULL || *s == '\0') {
  51                 uuid_create_nil(u, status);
  52                 return;
  53         }
  54
  55         /* Assume the worst. */
  56         if (status != NULL)
  57                 *status = uuid_s_invalid_string_uuid;
  58
  59         /* The UUID string representation has a fixed length. */
  60         if (strlen(s) != 36)
  61                 return;
  62
  63         /*
  64          * We only work with "new" UUIDs. New UUIDs have the form:
  65          *      01234567-89ab-cdef-0123-456789abcdef
  66          * The so called "old" UUIDs, which we don't support, have the form:
  67          *      0123456789ab.cd.ef.01.23.45.67.89.ab
  68          */
  69         if (s[8] != '-')
  70                 return;
  71
  72         n = sscanf(s,
  73             "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
  74             &u->time_low, &u->time_mid, &u->time_hi_and_version,
  75             &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
  76             &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);
  77
  78         /* Make sure we have all conversions. */
  79         if (n != 11)
  80                 return;
  81
  82         /* We have a successful scan. Check semantics... */
  83         n = u->clock_seq_hi_and_reserved;
  84         if ((n & 0x80) != 0x00 &&                       /* variant 0? */
  85             (n & 0xc0) != 0x80 &&                       /* variant 1? */
  86             (n & 0xe0) != 0xc0) {                       /* variant 2? */
  87                 if (status != NULL)
  88                         *status = uuid_s_bad_version;
  89         } else {
  90                 if (status != NULL)
  91                         *status = uuid_s_ok;
  92         }
  93 }