lib/libc/uuid/uuid_from_string.c

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c) 2002 Marcel Moolenaar
   5  * Copyright (c) 2002 Hiten Mahesh Pandya
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/lib/libc/uuid/uuid_from_string.c,v 1.2 2003/08/08 19:18:43 marcel Exp $
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 __RCSID("$NetBSD$");
  35 #endif
  36
  37 #include "namespace.h"
  38
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <uuid.h>
  42
  43 /*
  44  * uuid_from_string() - convert a string representation of an UUID into
  45  *                      a binary representation.
  46  * See also:
  47  *      http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
  48  *
  49  * NOTE: The sequence field is in big-endian, while the time fields are in
  50  *       native byte order.
  51  */
  52 void
  53 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
  54 {
  55         int n;
  56
  57         /* Short-circuit 2 special cases: NULL pointer and empty string. */
  58         if (s == NULL || *s == '\0') {
  59                 uuid_create_nil(u, status);
  60                 return;
  61         }
  62
  63         /* Assume the worst. */
  64         if (status != NULL)
  65                 *status = uuid_s_invalid_string_uuid;
  66
  67         /* The UUID string representation has a fixed length. */
  68         if (strlen(s) != 36)
  69                 return;
  70
  71         /*
  72          * We only work with "new" UUIDs. New UUIDs have the form:
  73          *      01234567-89ab-cdef-0123-456789abcdef
  74          * The so called "old" UUIDs, which we don't support, have the form:
  75          *      0123456789ab.cd.ef.01.23.45.67.89.ab
  76          */
  77         if (s[8] != '-')
  78                 return;
  79
  80         n = sscanf(s,
  81             "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
  82             &u->time_low, &u->time_mid, &u->time_hi_and_version,
  83             &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
  84             &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);
  85
  86         /* Make sure we have all conversions. */
  87         if (n != 11)
  88                 return;
  89
  90         /* We have a successful scan. Check semantics... */
  91         n = u->clock_seq_hi_and_reserved;
  92         if ((n & 0x80) != 0x00 &&                       /* variant 0? */
  93             (n & 0xc0) != 0x80 &&                       /* variant 1? */
  94             (n & 0xe0) != 0xc0) {                       /* variant 2? */
  95                 if (status != NULL)
  96                         *status = uuid_s_bad_version;
  97         } else {
  98                 if (status != NULL)
  99                         *status = uuid_s_ok;
 100         }
 101 }